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Sample records for predict extubation failure

  1. Extubating Extremely Preterm Infants: Predictors of Success and Outcomes following Failure.

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    Manley, Brett J; Doyle, Lex W; Owen, Louise S; Davis, Peter G

    2016-06-01

    To identify variables that predict extubation success in extremely preterm infants born successful or failed extubation. A secondary analysis of data from a randomized trial of postextubation respiratory support that included 174 extremely preterm infants. "Extubation success" was defined as not requiring reintubation within 7 days, and "extubation failure" the converse. Predictive variables that were different between groups were included in a multivariable logistic regression model. Sixty-eight percent of infants were successfully extubated. Compared with those infants who had extubation failure, they had a higher GA and birth weight, were extubated earlier, were more often exposed to prolonged ruptured membranes, more often avoided intubation in the delivery room, had a higher pre-extubation pH, and had lower mean pre-extubation fraction of inspired oxygen and partial pressure of carbon dioxide (PCO2). Only GA and PCO2 remained significant in the multivariable analysis (area under a receiver operating characteristic curve = 0.81). Extubation failure was associated with death, bronchopulmonary dysplasia, severe retinopathy of prematurity, patent ductus arteriosus ligation, and longer durations of respiratory support, oxygen supplementation, and hospitalization. When adjusted for allocated treatment in the randomized trial, GA, and birth weight z-score, extubation failure remained associated with death before discharge and prolonged respiratory support and hospitalization. In extremely preterm infants, higher GA and lower pre-extubation PCO2 predicted extubation success. Infants in whom extubation failed were more likely to die and have prolonged respiratory support and hospitalization. Australian New Zealand Clinical Trials Network: ACTRN12610000166077. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Spontaneous breathing test in the prediction of extubation failure in the pediatric population.

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    Nascimento, Milena Siciliano; Rebello, Celso Moura; Vale, Luciana Assis Pires Andrade; Santos, Érica; Prado, Cristiane do

    2017-01-01

    To assess whether the spontaneous breathing test can predict the extubation failure in pediatric population. A prospective and observational study that evaluated data of inpatients at the Pediatric Intensive Care Unit between May 2011 and August 2013, receiving mechanical ventilation for at least 24 hours followed by extubation. The patients were classified in two groups: Test Group, with patients extubated after spontaneous breathing test, and Control Group, with patients extubated without spontaneous breathing test. A total of 95 children were enrolled in the study, 71 in the Test Group and 24 in the Control Group. A direct comparison was made between the two groups regarding sex, age, mechanical ventilation time, indication to start mechanical ventilation and respiratory parameters before extubation in the Control Group, and before the spontaneous breathing test in the Test Group. There was no difference between the parameters evaluated. According to the analysis of probability of extubation failure between the two groups, the likelihood of extubation failure in the Control Group was 1,412 higher than in the Test Group, nevertheless, this range did not reach significance (p=0.706). This model was considered well-adjusted according to the Hosmer-Lemeshow test (p=0.758). The spontaneous breathing test was not able to predict the extubation failure in pediatric population. Avaliar se o teste de respiração espontânea pode ser utilizado para predizer falha da extubação na população pediátrica. Estudo prospectivo, observacional, no qual foram avaliados todos os pacientes internados no Centro de Terapia Intensiva Pediátrica, no período de maio de 2011 a agosto de 2013, que utilizaram ventilação mecânica por mais de 24 horas e que foram extubados. Os pacientes foram classificados em dois grupos: Grupo Teste, que incluiu os pacientes extubados depois do teste de respiração espontânea; e Grupo Controle, pacientes foram sem teste de respiração espont

  3. Noninvasive work of breathing improves prediction of post-extubation outcome.

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    Banner, Michael J; Euliano, Neil R; Martin, A Daniel; Al-Rawas, Nawar; Layon, A Joseph; Gabrielli, Andrea

    2012-02-01

    We hypothesized that non-invasively determined work of breathing per minute (WOB(N)/min) (esophageal balloon not required) may be useful for predicting extubation outcome, i.e., appropriate work of breathing values may be associated with extubation success, while inappropriately increased values may be associated with failure. Adult candidates for extubation were divided into a training set (n = 38) to determine threshold values of indices for assessing extubation and a prospective validation set (n = 59) to determine the predictive power of the threshold values for patients successfully extubated and those who failed extubation. All were evaluated for extubation during a spontaneous breathing trial (5 cmH(2)O pressure support ventilation, 5 cmH(2)O positive end expiratory pressure) using routine clinical practice standards. WOB(N)/min data were blinded to attending physicians. Area under the receiver operating characteristic curves (AUC), sensitivity, specificity, and positive and negative predictive values of all extubation indices were determined. AUC for WOB(N)/min was 0.96 and significantly greater (p indices. WOB(N)/min had a specificity of 0.83, the highest sensitivity at 0.96, positive predictive value at 0.84, and negative predictive value at 0.96 compared to all indices. For 95% of those successfully extubated, WOB(N)/min was ≤10 J/min. WOB(N)/min had the greatest overall predictive accuracy for extubation compared to traditional indices. WOB(N)/min warrants consideration for use in a complementary manner with spontaneous breathing pattern data for predicting extubation outcome.

  4. Predicting Extubation Outcome by Cough Peak Flow Measured Using a Built-in Ventilator Flow Meter.

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    Gobert, Florent; Yonis, Hodane; Tapponnier, Romain; Fernandez, Raul; Labaune, Marie-Aude; Burle, Jean-François; Barbier, Jack; Vincent, Bernard; Cleyet, Maria; Richard, Jean-Christophe; Guérin, Claude

    2017-12-01

    Successful weaning from mechanical ventilation depends on the patient's ability to cough efficiently. Cough peak flow (CPF) could predict extubation success using a dedicated flow meter but required patient disconnection. We aimed to predict extubation outcome using an overall model, including cough performance assessed by a ventilator flow meter. This was a prospective observational study conducted from November 2014 to October 2015. Before and after a spontaneous breathing trial, subjects were encouraged to cough as strongly as possible before freezing the ventilator screen to assess CPF and tidal volume (V T ) in the preceding inspiration. Early extubation success rate was defined as the proportion of subjects not re-intubated 48 h after extubation. Diagnostic performance of CPF and V T was assessed by using the area under the curve of the receiver operating characteristic curve. Cut-off values for CPF and V T were defined according to median values and used to describe the performance of a predictive test combining them with risk factors of early extubation failure. Among 673 subjects admitted, 92 had a cough assessment before extubation. For the 81 subjects with early extubation success, the median CPF was -67.7 L/min, and median V T was 0.646 L. For the 11 subjects with early extubation failure, the median CPF was -57.3 L/min, and median V T was 0.448 L. Area under the curve was 0.61 (95% CI 0.37-0.83) for CPF and 0.64 (95% CI 0.42-0.84) for CPF/V T combined. After dichotomization (CPF 0.55 L), there was a synergistic effect to predict early extubation success ( P meter of an ICU ventilator was able to predict extubation success and to build a composite score to predict extubation failure. The results were close to that found in previous studies that used a dedicated flow meter. This could help to identify high-risk subjects to prevent extubation failure. (ClinicalTrials.gov registration NCT02847221.). Copyright © 2017 by Daedalus Enterprises.

  5. [Predictors factors for the extubation failure in two or more times among preterm newborn].

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    Tapia-Rombo, Carlos Antonio; De León-Gómez, Noé; Ballesteros-Del-Olmo, Julio César; Ruelas-Vargas, Consuelo; Cuevas-Urióstegui, María Luisa; Castillo-Pérez, José Juan

    2010-01-01

    With the ventilatory mechanical attendance has been prolonged the life of the preterm newborn (PTNB) critically sick and during that lapse many occasions it is necessary reintubation to PTNB in two or more times with the subsequent damage that makes enter to the patient to a vicious circle with more damage during the same reintubated. The objective of this study was to determine the factors that predict the extubation failure among PTNB from 28 to 36 weeks of gestational age in two or more times. It was considered extubation failure when in the first 72 hours of being had extubated the patient; there was reintubation necessity, independent of the cause that originated it. For the second extubation or more took the same approach. During the period of September to December of the 2004 were included in retrospective study to all PTNB that were interned in one hospital of third level that fulfilled the inclusion approaches (one study published where we take account the first extubation failure) and in retrolective study to the patients of the same hospital of January to October of the 2006. They were formed two groups, group A of cases (who failed in extubation two or more times) and the B of controls (who failed in extubation for the first time). The descriptive statistic and the inferential through of Student t test or Mann-Whitney U or rank sum test Wilcoxon, in suitable case; Chi-square or Fisher's exact test was used. Odds ratio (OR) and multivariate analysis for to study predictors factors for the extubation failure was employed. Statistical significance was considered at p 2, OR 5.3, IC to 95% of 1.3-21.4 (P = 0.02). In the bronchoscopy study they were some anatomical alterations that they explained the extubation failure in the second time. We conclude that it is important to plan an extubation in the PTNB, when there has already been a previous failure, and to avoid the well-known predictors factors for extubation failure as much as possible in the extubation

  6. Prediction of extubation failure for neonates with respiratory distress syndrome using the MIMIC-II Clinical Database

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    Mikhno, A.; Ennett, C.M.

    2012-01-01

    Extubation failure (EF) is an ongoing problem in the neonatal intensive care unit (NICU). Nearly 25% of neonates fail their first extubation attempt, requiring re-intubations that are associated with riskfactors and financial costs. We identified 179 mechanically ventilated neonatal patients that

  7. Prediction of extubation outcome in preterm infants by composite extubation indices.

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    Dimitriou, Gabriel; Fouzas, Sotirios; Vervenioti, Aggeliki; Tzifas, Sotirios; Mantagos, Stefanos

    2011-11-01

    To determine whether composite extubation indices can predict extubation outcome in preterm infants. Prospective observational study. Level III neonatal intensive care unit. Fifty-six preterm infants cared for in the neonatal intensive care unit of a tertiary teaching hospital during 2007 and 2008. None. The study consisted of two parts. In the first part, different extubation indices were evaluated in a group of 28 neonates (derivation group). These indices included the diaphragmatic pressure-time index, the respiratory muscle pressure-time index, the maximal transdiaphragmatic pressure, the maximal inspiratory pressure, the airway pressure generated 100 milliseconds after an occlusion/maximal transdiaphragmatic pressure ratio, the airway pressure generated 100 milliseconds after an occlusion/maximal inspiratory pressure ratio, the tidal volume, and the respiratory rate to tidal volume ratio. After exploratory analysis, the best performing indices and the optimal threshold values to predict extubation outcome were selected. In the second part of the study, these indices were validated at the predetermined threshold values in an additional group of 28 preterm neonates (validation group). Four infants (14.3%) in the derivation group and four in the validation group (14.3%) failed extubation. Receiver operator characteristic curve analysis revealed that a diaphragmatic pressure-time index of ≤0.12, a respiratory muscle pressure-time index ≤0.10, a airway pressure generated 100 milliseconds after an occlusion/maximal transdiaphragmatic pressure of ≤0.14, and a airway pressure generated 100 milliseconds after an occlusion/maximal inspiratory pressure of ≤0.09 were the most accurate predictors of extubation outcome in the derivation group. In the validation group, a diaphragmatic pressure-time index of ≤0.12 and a respiratory muscle pressure-time index of ≤0.10 both had zero false-positive results, predicting with accuracy successful extubation. Composite

  8. Risk factors of extubation failure in extremely low birth weight infants: a five year retrospective analysis.

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    Lee, Chao-Yi; Su, Bai-Horng; Lin, Tsung-Wen; Lin, Hung-Chih; Li, Tsai-Chung; Wang, Nai-Phon

    2002-01-01

    Extubation failure is one of the most serious complications in extremely low birth weight infants (ELBWI) on mechanical ventilation therapy. We performed a 5-year retrospective analysis to realize the status of extubation failure in ELBWI. Extubation failure was defined as requirements of re-intubation within 72 hours after extubation. The extubation failure rate was 21% (29/138). The mean birth body weight was 808.3 +/- 140.4 gm. The mean gestational age was 25.8 +/- 1.2 wks. The incidence of chronic lung disease (CLD) in infants with extubation failure was 100% (29/29). Apnea of prematurity 49% (14/29) and post-extubation atelectasis 39% (11/29) were the most common reasons for reintubation. The major microbiology findings which correlated with nosocomial pneumonia in infants with extubation failure were Acinetobacter baumanni (21%), Klebsiella pneumonia (21%), Pseudomonas aeroginosa (14%), and Methicillin resistant staphylococcus aureus (14%). In conclusion, post-extubation atelectasis and apnea were the most common reasons for reintubation. ELBWI with extubation failure had higher incidences of post-extubation atelectasis, CLD, and nosocomial pneumonia. Further prospective studies are needed in order to clarify the appropriate extubation program for ELBWI and to prevent post-extubation atelectasis and nosocomial pneumonia.

  9. Comparison of clinical utility between diaphragm excursion and thickening change using ultrasonography to predict extubation success

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    Yoo, Jung-Wan; Lee, Seung Jun; Lee, Jong Deog; Kim, Ho Cheol

    2018-01-01

    Background/Aims Both diaphragmatic excursion and change in muscle thickening are measured using ultrasonography (US) to assess diaphragm function and mechanical ventilation weaning outcomes. However, which parameter can better predict successful extubation remains to be determined. The aim of this study was to compare the clinical utility of these two diaphragmatic parameters to predict extubation success. Methods This study included patients subjected to extubation trial in the medical or surgical intensive care unit of a university-affiliated hospital from May 2015 through February 2016. Diaphragm excursion and percent of thickening change (Δtdi%) were measured using US within 24 hours before extubation. Results Sixty patients were included, and 78.3% (47/60) of these patients were successfully extubated, whereas 21.7% (13/60) were not. The median degree of excursion was greater in patients with extubation success than in those with extubation failure (1.65 cm vs. 0.8 cm, p success had a greater Δtdi% than those with extubation failure (42.1% vs. 22.5%, p = 0.03). The areas under the receiver operating curve for excursion and Δtdi% were 0.836 (95% confidence interval [CI], 0.717 to 0.919) and 0.698 (95% CI, 0.566 to 0.810), respectively (p = 0.017). Conclusions Diaphragm excursion seems more accurate than a change in the diaphragm thickness to predict extubation success. PMID:29050461

  10. Simple motor tasks independently predict extubation failure in critically ill neurological patients.

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    Kutchak, Fernanda Machado; Rieder, Marcelo de Mello; Victorino, Josué Almeida; Meneguzzi, Carla; Poersch, Karla; Forgiarini, Luiz Alberto; Bianchin, Marino Muxfeldt

    2017-01-01

    To evaluate the usefulness of simple motor tasks such as hand grasping and tongue protrusion as predictors of extubation failure in critically ill neurological patients. This was a prospective cohort study conducted in the neurological ICU of a tertiary care hospital in the city of Porto Alegre, Brazil. Adult patients who had been intubated for neurological reasons and were eligible for weaning were included in the study. The ability of patients to perform simple motor tasks such as hand grasping and tongue protrusion was evaluated as a predictor of extubation failure. Data regarding duration of mechanical ventilation, length of ICU stay, length of hospital stay, mortality, and incidence of ventilator-associated pneumonia were collected. A total of 132 intubated patients who had been receiving mechanical ventilation for at least 24 h and who passed a spontaneous breathing trial were included in the analysis. Logistic regression showed that patient inability to grasp the hand of the examiner (relative risk = 1.57; 95% CI: 1.01-2.44; p commands is predictive of extubation failure in critically ill neurological patients. Hand grasping and tongue protrusion on command might be quick and easy bedside tests to identify neurocritical care patients who are candidates for extubation. Avaliar a utilidade de tarefas motoras simples, tais como preensão de mão e protrusão da língua, para predizer extubação malsucedida em pacientes neurológicos críticos. Estudo prospectivo de coorte realizado na UTI neurológica de um hospital terciário em Porto Alegre (RS). Pacientes adultos que haviam sido intubados por motivos neurológicos e que eram candidatos ao desmame foram incluídos no estudo. O estudo avaliou se a capacidade dos pacientes de realizar tarefas motoras simples como apertar as mãos do examinador e pôr a língua para fora seria um preditor de extubação malsucedida. Foram coletados dados referentes ao tempo de ventilação mecânica, tempo de internação na

  11. Establishing predictors for successfully planned endotracheal extubation.

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    Lai, Chih-Cheng; Chen, Chin-Ming; Chiang, Shyh-Ren; Liu, Wei-Lun; Weng, Shih-Feng; Sung, Mei-I; Hsing, Shu-Chen; Cheng, Kuo-Chen

    2016-10-01

    The aim of this study was to establish predictors for successfully planned extubation, which can be followed by medical personnel. The patients who were admitted to the adult intensive care unit of a tertiary hospital and met the following criteria between January 2005 and December 2014 were collected retrospectively: intubation > 48 hours; and candidate for extubation. The patient characteristics, including disease severity, rapid shallow breath index (RSBI), maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), cuff leak test (CLT) before extubation, and outcome, were recorded. The CLT was classified as 2+ with audible flow without a stethoscope, 1+ with audible flow using a stethoscope, and negative (N) with no audible flow, even with a stethoscope. Failure to extubate was defined as reintubation within 48 hours. In total, 6583 patients were enrolled and 403 patients (6.1%) had extubation failures. Male patients dominated the patient cohort (4261 [64.7%]). The mean age was 64.5±16.3 years. The overall in-hospital mortality rate was 11.3%. The extubation failure rate for females was greater than males (7.7% vs 5.3%, P respiratory capacity, was developed to better predict extubation success.

  12. Respiratory severity score and extubation readiness in very low birth weight infants

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    Maroun J. Mhanna

    2017-12-01

    Full Text Available Background: The respiratory severity score (RSS is a byproduct of mean airway pressure (MAP and fraction of inspired oxygen (FiO2. We sought to determine whether RSS could be used as a screening tool to predict extubation readiness in very low birth weight (VLBW infants. Methods: In a retrospective cohort study, medical records of all VLBW infants admitted to our unit (6/1/09–2/28/12 were reviewed for infants' demographics, prenatal characteristics, and medication use. Also, records were reviewed for unplanned vs. planned extubation, blood gas, ventilator parameters and signs of severe respiratory failure [RF, defined as partial pressure of carbon dioxide (pCO2 > 65, pH  50%, and MAP > 10 cm] on the day of extubation. Results: During the study period 31% (45/147 failed extubation. Overall, infants who failed extubation had a lower birth weight (BW and gestational age (GA, and on the day of extubation had a higher RSS and percentage of having one or more signs of severe RF. In a logistic regression model, adjusting for BW, GA, RSS and RF, RSS remained the only risk factor associated with extubation failure [adjusted OR 1.63 (95% CI: 1.10–2.40; p = 0.01]. RSS had a sensitivity of 0.86 (95% CI: 0.72–0.94 at a cutoff of 1.26 and a specificity of 0.88 (95% CI: 0.80–0.94 at a cutoff of 2.5. There was no difference in extubation failure between unplanned vs. planned extubation [41% (9/22 vs. 29% (36/125; p = 0.25]. Conclusion: An elevated RSS is associated with extubation failure. Successful unplanned extubation is common in VLBW infants. Key Words: very low birth weight, extubation, mechanical ventilation, respiratory severity score

  13. Post-extubation airway obstruction. Literature review

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    Álvaro SÁNCHEZ-TABERNERO

    2017-03-01

    Full Text Available Introduction and objective: airway obstruction after extubation in any surgery is a critical event with low incidence, which may require reintubation or tracheostomy, which often otolaryngologist is required. Objective: To determine the prevalence of BVA and its causes through systematic literature review. Method: Literature review in PubMed, Scopus and Cochrane clinical trials, meta-analysis, reviews and case series and control over airway obstruction after extubation that requires reintubation in adults. Results: 6 studies and one clinical practice guidelines were selected. The most common cause of extubation failure is blocking the airway for various reasons (pharyngeal muscle weakness residual effect -often farmacologycal-, laryngospasm, vocal cord paralysis, edema of upper respiratory tract, cervical postoperative hematoma, foreign bodies or secretions. Most cases of re-intubation occurred within 2 hours after extubation. Conclusions: The most common cause of failure after general anesthesia extubation is blocking the airway generally caused by residual neuromuscular blocking effect. Airway obstruction risk increases in airway and head and neck surgery. Difficult intubation guidlines have improved performance and reduced adverse events and similar strategies must be implemented in extubation. The procedure extubation and reintubation should be documented. Working groups airway must be multidisciplinary and include specialists in otolaryngology.

  14. Medida da freqüência respiratória e do volume corrente para prever a falha na extubação de recém-nascidos de muito baixo peso em ventilação mecânica Evaluation of respiratory rate and tidal volume to predict extubation failure in mechanically ventilated very low birth weight infants

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    Josy Davidson

    2008-03-01

    Full Text Available OBJETIVO: Verificar se a freqüência respiratória (FR, o volume corrente (VC e a relação FR/VC poderiam prever a falha na extubação em recém-nascidos de muito baixo peso submetidos à ventilação mecânica. MÉTODOS: Estudo prospectivo, observacional, de recém-nascidos com idade gestacional OBJECTIVE: To verify if respiratory rate (RR, tidal volume (TV and respiratory rate and tidal volume ratio (RR/TV could predict extubation failure in very low birth weight infants submitted to mechanical ventilation. METHODS: This prospective observational study enrolled newborn infants with gestational age <37 weeks and birth weight <1,500g, mechanically ventilated from birth during 48 hours to 30 days and thought to be ready for extubation. As soon as the physicians decided for extubation, the neonates received endotracheal continuous positive airway pressure (CPAP for 10 minutes while spontaneous RR, TV and RR/TV were measured using a fixed-orifice pneumotachograph positioned between the endotracheal tube and the ventilator circuit. Thereafter, the neonates were extubated to nasal CPAP. Extubation failure was defined as the need for reintubation within 48 hours. RESULTS: Of the 35 studied infants, 20 (57% were successfully extubated and 15 (43% required reintubation. RR and RR/TV before extubation had a trend to be higher in unsuccessfully extubated infants. TV was similar in both groups. Sensitivity and specificity of these parameters as predictors of extubation failure were 50 and 67% respectively for RR, 40 and 67% for TV and 40 and 73% for RR/TV. CONCLUSIONS: RR, TV and RR/TV showed low sensitivity and specificity to predict extubation failure in mechanically ventilated very low birth weight infants.

  15. The value of high-flow nasal cannula oxygen therapy after extubation in patients with acute respiratory failure

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    Hong-Zhuan Song

    Full Text Available OBJECTIVE: To investigate the value of high-flow nasal cannula oxygen therapy after extubation in patients with acute respiratory failure. METHODS: A single-center, prospective, randomized, controlled pilot trial was conducted between January 2013 and December 2014. Sixty enrolled patients were randomized immediately after extubation into either a high-flow nasal cannula group (n=30 or an air entrainment mask group (n=30 at a fixed inspired oxygen fraction (40%. The success rate of oxygen therapy, respiratory and hemodynamic parameters and subjective discomfort (using a visual analogue scale were assessed at 24h after extubation. RESULTS: The two groups were comparable at extubation. A total of 46 patients were successfully treated including 27 patients in the high-flow nasal cannula group and 19 patients in the air entrainment mask group. Compared to the air entrainment mask group, the success rate of oxygen therapy and the partial pressure of arterial oxygen were significantly higher and the respiratory rate was lower in the high-flow nasal cannula group. In addition, less discomfort related to interface displacement and airway dryness was observed in the high-flow nasal cannula group than in the air entrainment mask group. CONCLUSIONS: At a fixed inspired oxygen fraction, the application of a high-flow nasal cannula after extubation achieves a higher success rate of oxygen therapy and less discomfort at 24h than an air entrainment mask in patients with acute respiratory failure.

  16. Early extubation after congenital heart surgery

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    Mirza Halimić

    2014-12-01

    Full Text Available Introduction: Despite recent advances in anesthesia, cardiopulmonary bypass and surgical techniques, children undergoing congenital heart surgery require postoperativemechanical ventilation. Early extubation was definedas ventilation shorter than 12 hours. Aim of this study is to identify factors associated with successful early extubation after pediatric cardiac surgery.Methods: The study was performed during period from January 2006 to January 2011 at Pediatric Clinic and Heart Center University Clinical center Sarajevo. One hundred children up to 5 years of age, who have had congenital heart disease, with left–right shunt and obstructive heart disease were included in the study. Patients were divided into two groups: Group I - patients extubated within 12 hours after surgery and Group II - patients extubated 12 or more hours after surgery. Results: The most frequently encountered preoperative variables were age with odds ratio 4% 95%CI (1-7%, Down's syndrome 8.5 95%CI (1.6-43.15, failure to thrive 4.3 95%CI( 1-18. Statistically significant postoperative data included lung disease (reactive airways, pneumonia, atelectasis, pneumothorax and with odds ratio 35.1 95 %CI (4-286 and blood transfusion with odds ratio 4.6 95%CI (2-12. Blood transfusion (p=0.002 (Wald=9.2 95%CI (2-12, during as well as after operation procedure has statistically significant influence on prediction time of extubation. Proven markers were age with cut of 21.5 months (sensitivity 74% and specificity 70% and extracorporeal circulation (ECC with cut-of 45.5 minutes (sensitivity 71% and specificity 65%.Conclusion: Early extubation is possible in many children undergoing congenital heart surgery. Younger age and prolonged ECC time are markers associated with prolonged mechanical ventilation.

  17. Cuff leak test and laryngeal survey for predicting post-extubation stridor.

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    Patel, Anit B; Ani, Chizobam; Feeney, Colin

    2015-02-01

    Evidence for the predictive value of the cuff leak test (CLT) for post-extubation stridor (PES) is conflicting. We evaluated the association and accuracy of CLT alone or combined with other laryngeal parameters with PES. Fifty-one mechanically ventilated adult patients in a medical-surgical intensive care unit were tested prior to extubation using; CLT, laryngeal ultrasound and indirect laryngoscopy. Biometric, laryngeal and endotracheal tube (ETT) parameters were recorded. PES incidence was 4%. CLT demonstrated 'no leak' in 20% of patients. Laryngeal oedema was present in 10% of the patients on indirect laryngoscopy, and 71% of the patients had a Grades 1-3 indirect laryngoscopic view. Mean air column width on laryngeal ultrasound was 0.66 ± 0.15 cm (cuff deflated), mean ratio of ETT to laryngeal diameter was 0.48 ± 0.07, and the calculated CLT and laryngeal survey composite was 0.86 ± 1.25 (range 0-5). CLT and the CLT and Laryngeal survey composite measure were not associated with or predict PES. Age, sex, peri-extubation steroid use, intubation duration and body mass index were not associated with PES. Even including ultrasonographic and indirect laryngoscopic examination of the airway, no single aspect of the CLT or combination with laryngeal parameters accurately predicts PES.

  18. Pulmonary Dead Space Fraction and Extubation Success in Children After Cardiac Surgery.

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    Devor, Renee L; Kang, Paul; Wellnitz, Chasity; Nigro, John J; Velez, Daniel A; Willis, Brigham C

    2018-04-01

    1) Determine the correlation between pulmonary dead space fraction and extubation success in postoperative pediatric cardiac patients; and 2) document the natural history of pulmonary dead space fractions, dynamic compliance, and airway resistance during the first 72 hours postoperatively in postoperative pediatric cardiac patients. A retrospective chart review. Cardiac ICU in a quaternary care free-standing children's hospital. Twenty-nine with balanced single ventricle physiology, 61 with two ventricle physiology. None. We collected data for all pediatric patients undergoing congenital cardiac surgery over a 14-month period during the first 72 hours postoperatively as well as prior to extubation. Overall, patients with successful extubations had lower preextubation dead space fractions and shorter lengths of stay. Single ventricle patients had higher initial postoperative and preextubation dead space fractions. Two-ventricle physiology patients had higher extubation failure rates if the preextubation dead space fraction was greater than 0.5, whereas single ventricle patients had similar extubation failure rates whether preextubation dead space fractions were less than or equal to 0.5 or greater than 0.5. Additionally, increasing initial dead space fraction values predicted prolonged mechanical ventilation times. Airway resistance and dynamic compliance were similar between those with successful extubations and those who failed. Initial postoperative dead space fraction correlates with the length of mechanical ventilation in two ventricle patients but not in single ventricle patients. Lower preextubation dead space fractions are a strong predictor of successful extubation in two ventricle patients after cardiac surgery, but may not be as useful in single ventricle patients.

  19. Unplanned versus planned extubation in respiratory intensive care unit, predictors of outcome

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    Mohammed F. Ismaeil

    2014-01-01

    Conclusions: An increase in severity of illness on ICU admission, agitation, less use of sedation with lower Ramsay score during MV intensify the risk of unplanned extubation, which usually occurs during the night shift, even with the use of physical restraints. Unplanned extubation is associated with an increased incidence of failed extubation (especially with accidental extubation and mortality. Factors affecting airway competence; magnitude of cough on command and abundant amount of E/T secretions are significant predictors of extubation failure in planned and unplanned extubation. Prolonged minute ventilation recovery time, failed DSA test and lower swallowing score are associated with an increased risk of failed planned extubation.

  20. Noninvasive positive pressure ventilation in unplanned extubation

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    Eryuksel, Emel; Sait, Karakurt; Celikel, Turgay [Dept. of Pulmonary and Critical Care, Marmara Univ. Hospital, (Turkey)

    2009-07-01

    Unplanned extubation is quite common in intensive care unit (ICU) patients receiving mechanical ventilatory support. The present study aimed to investigate the effectiveness of noninvasive positive pressure ventilation (NPPV) in patients with unplanned extubation. A total of 15 patients (12 male, age: 57 + - 24 years, APACHE II score: 19 + - 7) monitored at the medical ICU during the year 2004 who developed unplanned extubation were included in the study. NPPV was tried in all of them following unplanned extubation. Indications for admission to the ICU were as follows: nine patients with pneumonia, three with status epilepticus, one with gastrointestinal bleeding, one with cardiogenic pulmonary edema and one with diffuse alveolar bleeding. Eleven of the patients (74%) were at the weaning period at the time of unplanned extubation. Among these 11 patients, NPPV was successful in 10 (91%) and only one (9%) was reintubated due to the failure of NPPV. The remaining four patients (26%) had pneumonia and none of them were at the weaning period at the time of extubation, but their requirement for mechanical ventilation was gradually decreasing. Unfortunately, an NPPV attempt for 6-8 h failed and these patients were reintubated. Patients with unplanned extubation before the weaning criteria are met should be intubated immediately. On the other hand, when extubation develops during the weaning period, NPPV may be an alternative. The present study was conducted with a small number of patients, and larger studies on the effectiveness of NPPV in unplanned extubation are warranted for firm conclusions. (author)

  1. Noninvasive positive pressure ventilation in unplanned extubation

    International Nuclear Information System (INIS)

    Eryuksel, Emel; Karakurt Sait; Celikel, Turgay

    2009-01-01

    Unplanned extubation is quite common in intensive care unit (ICU) patients receiving mechanical ventilatory support. The present study aimed to investigate the effectiveness of noninvasive positive pressure ventilation (NPPV) in patients with unplanned extubation. A total of 15 patients (12 male, age: 57 + - 24 years, APACHE II score: 19 + - 7) monitored at the medical ICU during the year 2004 who developed unplanned extubation were included in the study. NPPV was tried in all of them following unplanned extubation. Indications for admission to the ICU were as follows: nine patients with pneumonia, three with status epilepticus, one with gastrointestinal bleeding, one with cardiogenic pulmonary edema and one with diffuse alveolar bleeding. Eleven of the patients (74%) were at the weaning period at the time of unplanned extubation. Among these 11 patients, NPPV was successful in 10 (91%) and only one (9%) was reintubated due to the failure of NPPV. The remaining four patients (26%) had pneumonia and none of them were at the weaning period at the time of extubation, but their requirement for mechanical ventilation was gradually decreasing. Unfortunately, an NPPV attempt for 6-8 h failed and these patients were reintubated. Patients with unplanned extubation before the weaning criteria are met should be intubated immediately. On the other hand, when extubation develops during the weaning period, NPPV may be an alternative. The present study was conducted with a small number of patients, and larger studies on the effectiveness of NPPV in unplanned extubation are warranted for firm conclusions. (author)

  2. PETCO2 measurement and feature extraction of capnogram signals for extubation outcomes from mechanical ventilation

    International Nuclear Information System (INIS)

    Rasera, Carmen C; Gewehr, Pedro M; Domingues, Adriana Maria T

    2015-01-01

    Capnography is a continuous and noninvasive method for carbon dioxide (CO 2 ) measurement, and it has become the standard of care for basic respiratory monitoring for intubated patients in the intensive care unit. In addition, it has been used to adjust ventilatory parameters during mechanical ventilation (MV). However, a substantial debate remains as to whether capnography is useful during the process of weaning and extubation from MV during the postoperative period. Thus, the main objective of this study was to present a new use for time-based capnography data by measuring the end-tidal CO 2 pressure (PET CO 2 ), partial pressure of arterial CO 2 (Pa CO 2 ) and feature extraction of capnogram signals before extubation from MV to evaluate the capnography as a predictor of outcome extubation in infants after cardiac surgery. Altogether, 82 measurements were analysed, 71.9% patients were successfully extubated, and 28.1% met the criteria for extubation failure within 48 h. The ROC-AUC analysis for quantitative measure of the capnogram showed significant differences (p < 0.001) for: expiratory time (0.873), slope of phase III (0.866), slope ratio (0.923) and ascending angle (0.897). In addition, the analysis of PET CO 2 (0.895) and Pa CO 2   (0.924) obtained 30 min before extubation showed significant differences between groups. The PET CO 2 mean value for success and failure extubation group was 39.04 mmHg and 46.27 mmHg, respectively. It was also observed that high CO 2 values in patients who had returned MV was 82.8  ±  21 mmHg at the time of extubation failure. Thus, PET CO 2 measurements and analysis of features extracted from a capnogram can differentiate extubation outcomes in infant patients under MV, thereby reducing the physiologic instability caused by failure in this process. (paper)

  3. Randomized controlled trial comparing nasal intermittent positive pressure ventilation and nasal continuous positive airway pressure in premature infants after tracheal extubation

    Directory of Open Access Journals (Sweden)

    Daniela Franco Rizzo Komatsu

    Full Text Available Summary Objective: To analyze the frequency of extubation failure in premature infants using conventional mechanical ventilation (MV after extubation in groups subjected to nasal intermittent positive pressure ventilation (nIPPV and continuous positive airway pressure (nCPAP. Method: Seventy-two premature infants with respiratory failure were studied, with a gestational age (GA ≤ 36 weeks and birth weight (BW > 750 g, who required tracheal intubation and mechanical ventilation. The study was controlled and randomized in order to ensure that the members of the groups used in the research were chosen at random. Randomization was performed at the time of extubation using sealed envelopes. Extubation failure was defined as the need for re-intubation and mechanical ventilation during the first 72 hours after extubation. Results: Among the 36 premature infants randomized to nIPPV, six (16.6% presented extubation failure in comparison to 11 (30.5% of the 36 premature infants randomized to nCPAP. There was no statistical difference between the two study groups regarding BW, GA, classification of the premature infant, and MV time. The main cause of extubation failure was the occurrence of apnea. Gastrointestinal and neurological complications did not occur in the premature infants participating in the study. Conclusion: We found that, despite the extubation failure of the group of premature infants submitted to nIPPV being numerically smaller than in premature infants submitted to nCPAP, there was no statistically significant difference between the two modes of ventilatory support after extubation.

  4. Bubble vs conventional continuous positive airway pressure for prevention of extubation failure in preterm very low birth weight infants: a pilot study.

    Science.gov (United States)

    Yadav, Sucheta; Thukral, Anu; Sankar, M Jeeva; Sreenivas, V; Deorari, Ashok K; Paul, Vinod K; Agarwal, Ramesh

    2012-09-01

    To compare the efficacy of bubble and conventional nasal continuous positive airway pressure (CPAP) in preventing extubation failure (EF) in preterm infants. Infants of gestation ≤32 wk and birth weight <1500 g, ready for initial extubation within first wk of life were randomly allocated to either bubble (n = 16) or conventional (n = 16) CPAP. A standardized protocol was used for extubation. Bubble CPAP was delivered by Fischer and Paykel equipment using short binasal prongs and conventional CPAP was delivered by a ventilator using Argyle short binasal prongs. CPAP was initiated at a pressure of 4-6 cm of H(2)O and FiO(2) of 0.4-0.5 and adjusted to maintain normal saturation (90-93%) and comfortable breathing. Primary outcome was EF, defined as need for mechanical ventilation within 72 h of extubation. Baseline characteristics including birth weight (g; 1027 ± 243 vs. 1018 ± 227; p = 0.83), gestation (wk; 28.7 ± 1.8 vs. 28.4 ± 1.6; p = 0.30), infants <28 wk gestation (6 vs. 7, p = 0.72) were comparable between the two groups. Respiratory distress syndrome was the indication for ventilation in 13 (81%) and 14 (87%) infants on bubble CPAP and conventional CPAP groups respectively. (p = 0.99). There was no difference in the EF rates between the bubble (n = 4) and conventional CPAP (n = 9) groups. (RR 0.49; 95% CI 0.20-1.2; p = 0.14). Median time to extubation failure was also comparable between the two groups (h; median [range]: 29 [14-49] vs. 17 [7-28]; p = 0.35). The possibility that bubble CPAP may be associated with reduced EF as suggested in this pilot study requires further investigation in an adequately powered multicentric study.

  5. Efficacy and predictors of success of noninvasive ventilation for prevention of extubation failure in critically ill children with heart disease.

    Science.gov (United States)

    Gupta, Punkaj; Kuperstock, Jacob E; Hashmi, Sana; Arnolde, Vickie; Gossett, Jeffrey M; Prodhan, Parthak; Venkataraman, Shekhar; Roth, Stephen J

    2013-04-01

    The study aimed primarily to evaluate the efficacy of noninvasive ventilation (NIV) and to identify possible predictors for success of NIV therapy in preventing extubation failure in critically ill children with heart disease. The secondary objectives of this study were to assess the efficacy of prophylactic NIV therapy initiated immediately after tracheal extubation and to determine the characteristics, outcomes, and complications associated with NIV therapy in pediatric cardiac patients. A retrospective review examined the medical records of all children between the ages 1 day and 18 years who sustained acute respiratory failure (ARF) that required NIV in the cardiovascular intensive care unit (CVICU) at Lucile Packard Children's Hospital between January 2008 and June 2010. Patients were assigned to a prophylactic group if NIV was started directly after extubation and to a nonprophylactic group if NIV was started after signs and symptoms of ARF developed. Patients were designated as responders if they received NIV and did not require reintubation during their CVICU stay and nonresponders if they failed NIV and reintubation was performed. The data collected included demographic data, preexisting conditions, pre-event characteristics, event characteristics, and outcome data. The outcome data evaluated included success or failure of NIV, duration of NIV, CVICU length of stay (LOS), hospital LOS, and hospital mortality. The two complications of NIV assessed in the study included nasal bridge or forehead skin necrosis and pneumothorax. The 221 eligible events during the study period involved 172 responders (77.8 %) and 49 nonresponders (22.2 %). A total of 201 events experienced by the study cohort received continuous positive airway pressure (CPAP), with 156 responders (78 %), whereas 20 events received bilevel positive airway pressure (BiPAP), with 16 responders (80 %). In the study, 58 events (26.3 %) were assigned to the prophylactic group and 163 events (73

  6. Predictive Factors for Delayed Extubation in the Intensive Care Unit after Coronary Artery Bypass Grafting; A Southern Iranian Experience

    Directory of Open Access Journals (Sweden)

    Shahrbanoo Shahbazi

    2012-12-01

    Full Text Available Background: Early extubation is implemented in cardiothoracic units worldwide for its advantages such as decreased mortality, morbidity, and hospitalization costs. We conducted a retrospective study to evaluate potential factors which may affect extubation time. Methods: The records of 334 eligible patients who underwent elective coronary artery bypass grafting (CABG in 2008 in Kowsar Hospital in Shiraz, southern Iran were evaluated to find the factors that can affect the extubation time. The patients were divided to early (equal or less than 6 hours and late extubation groups. The patients’ demographic data and operative variables were extracted from the records. We excluded patients with difficult intubation, severe acid base disturbance, neurological problems, and cardiovascular instability; and those who used intra-aortic balloon pump, had underwent emergency operation, or had another concomitant surgery. Results: Multiple logistic regressions comparing age, sex, number of grafts, ejection fraction, pump time, hematocrit, number of risk factors, and number of inotropic drugs, identified only age as a predictor of delayed extubation (odds ratio=1.07, CI 95%=1.04-1.10, P<0.001. Also, in both studied groups the men to women ratio was higher (P<0.05.Conclusion: Although in our study age was the only predictive factor for delayed extubation, a comprehensive study including preoperative, perioperative, and postoperative factors is recommended in our area.

  7. EXTUBATE: A randomised controlled trial of nasal biphasic positive airway pressure vs. nasal continuous positive airway pressure following extubation in infants less than 30 weeks' gestation: study protocol for a randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Victor Suresh

    2011-12-01

    Full Text Available Abstract Background Respiratory distress syndrome remains a significant problem among premature infants. Mechanical ventilation through an endotracheal tube remains the mainstay of respiratory support but may be associated with lung injury and the development of chronic lung disease of prematurity. Efforts are needed to reduce the duration of mechanical ventilation in favour of less invasive forms of respiratory support and to improve rates of successful extubation. Non-invasive respiratory support has been demonstrated to be less injurious to the premature lung. Standard practice is to use nasal continuous positive airway pressure (n-CPAP following extubation to support the baby's breathing. Many clinicians also use nasal biphasic positive airway pressure (n-BiPAP in efforts to improve rates of successful extubation. However, there is currently no evidence that this confers any advantage over conventional nasal continuous positive airway pressure. Methods We propose an unblinded multi-centre randomised trial comparing n-CPAP with n-BiPAP in babies born before 30 weeks' gestation and less than two weeks old. Babies with congenital abnormalities and severe intra-ventricular haemorrhage will be excluded. 540 babies admitted to neonatal centres in England will be randomised at the time of first extubation attempt. The primary aim of this study is to compare the rate of extubation failure within 48 hours following the first attempt at extubation. The secondary aims are to compare the effect of n-BiPAP and n-CPAP on the following outcomes: 1. Maintenance of successful extubation for 7 days post extubation 2. Oxygen requirement at 28 days of age and at 36 weeks' corrected gestational age 3. Total days on ventilator, n-CPAP/n-BiPAP 4. Number of ventilator days following first extubation attempt 5. pH and partial pressure of carbon dioxide in the first post extubation blood gas 6. Duration of hospital stay 7. Rate of abdominal distension requiring

  8. Nasal continuous positive airways pressure immediately after extubation for preventing morbidity in preterm infants.

    Science.gov (United States)

    Davis, P G; Henderson-Smart, D J

    2003-01-01

    Preterm infants being extubated following a period of intermittent positive pressure ventilation via an endotracheal tube are at risk of developing respiratory failure as a result of apnea, respiratory acidosis and hypoxia. Nasal continuous positive airway pressure appears to stabilise the upper airway, improve lung function and reduce apnea and may therefore have a role in facilitating extubation in this population. In preterm infants having their endotracheal tube removed following a period of intermittent positive pressure ventilation (IPPV), does management with nasal continuous positive airways pressure (NCPAP) lead to an increased proportion remaining free of additional ventilatory support, compared to extubation directly to headbox oxygen? Searches were made of the Oxford Database of Perinatal Trials, MEDLINE up to November 2002, Cochrane Controlled Trials Register (The Cochrane Library, Issue 4, 2002), previous reviews including cross references, abstracts of conferences and symposia proceedings, expert informants and journal handsearching mainly in the English language. All trials utilising random or quasi-random patient allocation, in which NCPAP (delivered by any method) was compared with headbox oxygen for post-extubation care were included. Methodological quality was assessed independently by the two authors. Data were extracted independently by the two authors. Prespecified subgroup analysis to determine the impact of different levels of NCPAP, differences in duration of IPPV and use of aminophylline were also performed using the same package. Data were analysed using relative risk (RR), risk difference (RD) and number needed to treat (NNT). Nasal CPAP, when applied to preterm infants being extubated following IPPV, reduces the incidence of adverse clinical events (apnea, respiratory acidosis and increased oxygen requirements) indicating the need for additional ventilatory support [RR 0.62 (0.49, 0.77), RD -0.17 (-0.24,-0.10), NNT 6 (4,10)]. nasal

  9. Predictors of successful early extubation following congenital cardiac surgery in neonates and infants.

    Science.gov (United States)

    Winch, Peter D; Nicholson, Lisa; Isaacs, Janet; Spanos, Steven; Olshove, Vincent; Naguib, Aymen

    2009-08-01

    There is a paucity of literature discussing the predictive likelihood of successfully extubating neonates and infants in the operating room immediately following congenital cardiac surgery. Given the unknown consequences of anaesthetics on neurodevelopmental outcomes, minimising the exposure of this population to such agents may have long-term benefits. Retrospective chart review of 391 patients less than 1 year of age. The probability of successfully extubating these patients was based on quantifiable, objective criteria. The relevant variables include age, weight, bypass time, lactate level and specific congenital anomaly. The practice of immediate extubation of infants and neonates is achievable, safe and predicted based on specific patient variables. This practice will minimise the anaesthetic exposure of these especially young patients who may be at risk for long-term consequences related to anaesthetic exposure.

  10. Learning From Experience: Improving Early Tracheal Extubation Success After Congenital Cardiac Surgery.

    Science.gov (United States)

    Winch, Peter D; Staudt, Anna M; Sebastian, Roby; Corridore, Marco; Tumin, Dmitry; Simsic, Janet; Galantowicz, Mark; Naguib, Aymen; Tobias, Joseph D

    2016-07-01

    The many advantages of early tracheal extubation following congenital cardiac surgery in young infants and children are now widely recognized. Benefits include avoiding the morbidity associated with prolonged intubation and the consequences of sedation and positive pressure ventilation in the setting of altered cardiopulmonary physiology. Our practice of tracheal extubation of young infants in the operating room following cardiac surgery has evolved and new challenges in the arena of postoperative sedation and pain management have appeared. Review our institutional outcomes associated with early tracheal extubation following congenital cardiac surgery. Inclusion criteria included all children less than 1 year old who underwent congenital cardiac surgery between October 1, 2010, and October 24, 2013. A total of 416 patients less than 1 year old were included. Of the 416 patients, 234 underwent tracheal extubation in the operating room (56%) with 25 requiring reintubation (10.7%), either immediately or following admission to the cardiothoracic ICU. Of the 25 patients extubated in the operating room who required reintubation, 22 failed within 24 hours of cardiothoracic ICU admission; 10 failures were directly related to narcotic doses that resulted in respiratory depression. As a result of this review, we have instituted changes in our cardiothoracic ICU postoperative care plans. We have developed a neonatal delirium score, and have adopted the "Kangaroo Care" approach that was first popularized in neonatal ICUs. This provision allows for the early parental holding of infants following admission to the cardiothoracic ICU and allows for appropriately selected parents to sleep in the same beds alongside their postoperative children.

  11. Physiotherapy contributions to weaning and extubation of patients ...

    African Journals Online (AJOL)

    MV and (ii) describe current physiotherapy practice related to weaning and extubation. Methods ... and extubation; weaning interventions and physiotherapy modalities; physiotherapy autonomy; .... team in ICU on extubation of patients. .... in intensive care and maintenance of muscle strength have been shown to reduce the ...

  12. Phlebotomy for rapid weaning and extubation in COPD patient with secondary polycythemia and respiratory failure

    Directory of Open Access Journals (Sweden)

    Tripathy Swagata

    2010-01-01

    Full Text Available The increased incidence of ventilator-associated complications in patients with chronic obstructive pulmonary disease (COPD necessitates rapid weaning and extubation. The presence of secondary polycythemia in this subgroup increases the incidence of stroke and myocardial infarction due to hyperviscosity and tissue hypoxia. We present a 58-year-old male patient of COPD with secondary polycythemia (hematocrit 64% who had possible hyperviscosity-related complications leading to cardiac arrest after a minor surgical procedure. The patient developed ventilator dependence after recovery. Phlebotomy was done to remove 10% of total blood volume. Symptomatic improvement was dramatic. Improvement in weaning indices like rapid shallow breathing index and PaO 2 /PAO 2 was observed facilitating rapid weaning and early extubation. Monitored, acute phlebotomy is safe and cost-effective. It decreases blood volume and viscosity, increases cardiac output and improves exercise tolerance in patients.

  13. Unplanned extubations in an intensive care unit: Findings from a critical incident technique.

    Science.gov (United States)

    Danielis, Matteo; Chiaruttini, Simona; Palese, Alvisa

    2018-05-15

    Patients on mechanical ventilation are at risk of experiencing a potentially life-threatening unplanned extubation in the intensive care unit, which can lead to arrhythmias, bronchial aspiration, difficulty in reintubation or even sudden cardiac arrest. Although incidence and outcomes of the phenomenon have been documented in several quantitative studies, no studies have investigated the antecedents as experienced by critical care nurses. To gain a greater understanding of the antecedents of unplanned extubations. A qualitative study design involving the critical-incident technique. A total of 10 registered nurses who reported one or more episodes of unplanned extubations were involved in an in-depth interview. According to the nurses' experience, episodes of unplanned extubations are determined by predisposing, precipitating and mediating factors. The predisposing factors have been recognised in the (a) weaning programme (expected/unexpected decreased sedation) and in the (b) patient factors (increased needs due to discomfort, restlessness and desire to communicate). The precipitating factors have been divided into (a) organisational (failures in multi-professional communication), (b) environmental (excessive environmental chaos and barriers preventing direct surveillance) and (c) nursing care factors (ensuring privacy by creating barriers, avoiding disturbing other patients and poor nurse-to-patient ratio). Among the mediating factors, which are affected by the precipitating factors, decreased surveillance and mechanical restraints' use have been identified. Identifying risk factors of unplanned extubation, specifically those that are modifiable, such as increasing interprofessional communication, reducing excessive environment chaos, implementing strategies aimed at overcoming barriers threatening direct surveillance and ensuring appropriate nurse-to-patient ratio, can prevent the occurrence of these events. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Fast Track Extubation In Adult Patients On Pump Open Heart Surgery At A Tertiary Care Hospital.

    Science.gov (United States)

    Akhtar, Mohammad Irfan; Sharif, Hasanat; Hamid, Mohammad; Samad, Khalid; Khan, Fazal Hameed

    2016-01-01

    Fast-track cardiac surgery programs have been established as the standard of cardiac surgical care. Studies have shown that early extubation in elective cardiac surgery patients, including coronary and non-coronary open-heart surgery patients does not increase perioperative morbidity and mortality. The objective of this observational study was to determine the success and failure profile of fast track extubation (FTE) practice in adult open-heart surgical patients. The study was conducted at cardiac operating room and Cardiac Intensive Care Unit (CICU) of a tertiary care hospital for a period of nine months, i.e., from Oct 2014 to June-2015. All on pump elective adult cardiac surgery patients including isolated CABG, isolated Valve replacements, combined procedures and aortic root replacements were enrolled in the study. Standardized anesthetic technique was adopted. Surgical and bypass techniques were tailored according to the procedure. Success of Fast track extubation was defined as extubation within 6 hours of arrival in CICU. A total of 290 patients were recruited. The average age of the patients was 56.3±10.5 years. There were 77.6% male and 22.4% female patients. Overall success rate was 51.9% and failure rate was 48.1%. The peri-operative renal insufficiency, cross clamp time and CICU stay (hours) were significantly lower in success group. Re-intubation rate was 0.74%. The perioperative parameters were significantly better in success group and the safety was also demonstrated in the patients who were fast tracked successfully. To implement the practice in its full capacity and benefit, a fast track protocol needs to be devised to standardize the current practices and to disseminate the strategy among junior anaesthesiologists, perfusionists and nursing staff.

  15. Comparison of the effectiveness of high flow nasal oxygen cannula vs. standard non-rebreather oxygen face mask in post-extubation intensive care unit patients.

    Science.gov (United States)

    Brotfain, Evgeni; Zlotnik, Alexander; Schwartz, Andrei; Frenkel, Amit; Koyfman, Leonid; Gruenbaum, Shaun E; Klein, Moti

    2014-11-01

    Optimal oxygen supply is the cornerstone of the management of critically ill patients after extubation, especially in patients at high risk for extubation failure. In recent years, high flow oxygen system devices have offered an appropriate alternative to standard oxygen therapy devices such as conventional face masks and nasal prongs. To assess the clinical effects of high flow nasal cannula (HFNC) compared with standard oxygen face masks in Intensive Care Unit (ICU) patients after extubation. We retrospectively analyzed 67 consecutive ventilated critical care patients in the ICU over a period of 1 year. The patients were allocated to two treatment groups: HFNC (34 patients, group 1) and non-rebreathing oxygen face mask (NRB) (33 patients, group 2). Vital respiratory and hemodynamic parameters were assessed prior to extubation and 6 hours after extubation. The primary clinical outcomes measured were improvement in oxygenation, ventilation-free days, re-intubation, ICU length of stay, and mortality. The two groups demonstrated similar hemodynamic patterns before and after extubation. The respiratory rate was slightly elevated in both groups after extubation with no differences observed between groups. There were no statistically significant clinical differences in PaCO2. However, the use of HFNC resulted in improved PaO2/FiO2 post-extubation (P < 0.05). There were more ventilator-free days in the HFNC group (P< 0.05) and fewer patients required reintubation (1 vs. 6). There were no differences in ICU length of stay or mortality. This study demonstrated better oxygenation for patients treated with HFNC compared with NRB after extubation. HFNC may be more effective than standard oxygen supply devices for oxygenation in the post-extubation period.

  16. Avaliação da relação entre espaço morto e volume corrente como índice preditivo de falha de extubação Evaluation of the dead space to tidal volume ratio as a predictor of extubation failure

    Directory of Open Access Journals (Sweden)

    Albert Bousso

    2006-10-01

    (VD/VT as a predictor of extubation failure of children from mechanical ventilation. METHODS: From September 2001 to January 2003 we studied a cohort consisting of all children (1 day-15 years submitted to mechanical ventilation at a pediatric intensive care unit who were extubated and for whom pre-extubation ventilometry data were available, including the VD/VT ratio. Extubation success was defined as no need for any type of ventilatory support, invasive or otherwise, within 48 hours. Patients who tolerated extubation, with or without noninvasive support, were defined as success-R and compared with those who were reintubated. Statistic analysis was based on a VD/VT cutoff point of 0.65. RESULTS:During the study period 250 children received mechanical ventilation at the pediatric intensive care unit. Eighty-six of these children comprised the study sample. Twenty-one children (24.4% met the criteria for extubation failure, with 11 (12.8% of these requiring non-invasive support and 10 (11.6% reintubation. Their mean age was 16.8 (±30.1 months (median = 5.5 months. The mean VD/VT ratio for all cases was 0.62 (±0.18. Mean VD/VT ratios for patients with successful and failed extubations were 0.62 (±0.17 and 0.65 (±0.21 (p = 0.472, respectively. Logistic regression failed to reveal any statistically significant correlation between VD/VT ratio and success or failure of extubation (p = 0.8458, even for patients who were reintubated (p = 0.5576. CONCLUSIONS: In a pediatric population receiving mechanical ventilation due to a variety of etiologies, the VD/VT ratio was unable to predict the populations at risk of extubation failure or of reintubation.

  17. Factors leading to self-extubation of endotracheal tubes in the intensive care unit.

    Science.gov (United States)

    Huang, Yuan-Ting

    2009-01-01

    To discuss the factors leading to self-extubation of endotracheal tubes (ETTs) and explore the differences between the groups of patients who did and did not self-remove their ETTs. Self-extubation of ETTs has been reported to occur in 4.2% of severely ill patients and is associated with adverse medical effects. A case-control study. One hundred and thirty-nine subjects were recruited from a teaching hospital in southern Taiwan based on purposive sampling. The rate of self-extubation of ETTs was 6.4%. Analysis of the two groups demonstrated that significant variables were identified and fell into three categories: (1) the department to which the patient was admitted (p self-extubation of the ETT. Among the 44 patients who had self-extubation of their ETT, 28 met the criteria to be extubated, 70% and 81.8% of whom were not sedated, and self-extubation of their ETT was conscious of the act. Of the patients who attempted to self-remove their ETT, 80% were successful and 93.2% did not incur any adverse medical effects. The medical doctor and nurse should fully evaluate a patient's oxygenation status, decrease the length of the extubation training session for patients and extubate patients promptly when extubation criteria are met. Adopting a proactive approach to patient extubation will improve the overall quality of care.

  18. Efficacy of a new technique - INtubate-RECruit-SURfactant-Extubate - "IN-REC-SUR-E" - in preterm neonates with respiratory distress syndrome: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Vento, Giovanni; Pastorino, Roberta; Boni, Luca; Cota, Francesco; Carnielli, Virgilio; Cools, Filip; Dani, Carlo; Mosca, Fabio; Pillow, Jane; Polglase, Graeme; Tagliabue, Paolo; van Kaam, Anton H; Ventura, Maria Luisa; Tana, Milena; Tirone, Chiara; Aurilia, Claudia; Lio, Alessandra; Ricci, Cinzia; Gambacorta, Alessandro; Consigli, Chiara; D'Onofrio, Danila; Gizzi, Camilla; Massenzi, Luca; Cardilli, Viviana; Casati, Alessandra; Bottino, Roberto; Pontiggia, Federica; Ciarmoli, Elena; Martinelli, Stefano; Ilardi, Laura; Colnaghi, Mariarosa; Matassa, Piero Giuseppe; Vendettuoli, Valentina; Villani, Paolo; Fusco, Francesca; Gazzolo, Diego; Ricotti, Alberto; Ferrero, Federica; Stasi, Ilaria; Magaldi, Rosario; Maffei, Gianfranco; Presta, Giuseppe; Perniola, Roberto; Messina, Francesco; Montesano, Giovanna; Poggi, Chiara; Giordano, Lucio; Roma, Enza; Grassia, Carolina; Ausanio, Gaetano; Sandri, Fabrizio; Mescoli, Giovanna; Giura, Francesco; Garani, Giampaolo; Solinas, Agostina; Lucente, Maria; Nigro, Gabriella; Del Vecchio, Antonello; Petrillo, Flavia; Orfeo, Luigi; Grappone, Lidia; Quartulli, Lorenzo; Scorrano, Antonio; Messner, Hubert; Staffler, Alex; Gargano, Giancarlo; Balestri, Eleonora; Nobile, Stefano; Cacace, Caterina; Meli, Valerio; Dallaglio, Sara; Pasqua, Betta; Mattia, Loretta; Gitto, Eloisa; Vitaliti, Marcello; Re, Maria Paola; Vedovato, Stefania; Grison, Alessandra; Berardi, Alberto; Torcetta, Francesco; Guidotti, Isotta; di Fabio, Sandra; Maranella, Eugenia; Mondello, Isabella; Visentin, Stefano; Tormena, Francesca

    2016-08-18

    Although beneficial in clinical practice, the INtubate-SURfactant-Extubate (IN-SUR-E) method is not successful in all preterm neonates with respiratory distress syndrome, with a reported failure rate ranging from 19 to 69 %. One of the possible mechanisms responsible for the unsuccessful IN-SUR-E method, requiring subsequent re-intubation and mechanical ventilation, is the inability of the preterm lung to achieve and maintain an "optimal" functional residual capacity. The importance of lung recruitment before surfactant administration has been demonstrated in animal studies showing that recruitment leads to a more homogeneous surfactant distribution within the lungs. Therefore, the aim of this study is to compare the application of a recruitment maneuver using the high-frequency oscillatory ventilation (HFOV) modality just before the surfactant administration followed by rapid extubation (INtubate-RECruit-SURfactant-Extubate: IN-REC-SUR-E) with IN-SUR-E alone in spontaneously breathing preterm infants requiring nasal continuous positive airway pressure (nCPAP) as initial respiratory support and reaching pre-defined CPAP failure criteria. In this study, 206 spontaneously breathing infants born at 24(+0)-27(+6) weeks' gestation and failing nCPAP during the first 24 h of life, will be randomized to receive an HFOV recruitment maneuver (IN-REC-SUR-E) or no recruitment maneuver (IN-SUR-E) just prior to surfactant administration followed by prompt extubation. The primary outcome is the need for mechanical ventilation within the first 3 days of life. Infants in both groups will be considered to have reached the primary outcome when they are not extubated within 30 min after surfactant administration or when they meet the nCPAP failure criteria after extubation. From all available data no definitive evidence exists about a positive effect of recruitment before surfactant instillation, but a rationale exists for testing the following hypothesis: a lung recruitment

  19. Early Extubation in the Operating Room after Congenital Open-Heart Surgery.

    Science.gov (United States)

    Fukunishi, Takuma; Oka, Norihiko; Yoshii, Takeshi; Kobayashi, Kensuke; Inoue, Nobuyuki; Horai, Tetsuya; Kitamura, Tadashi; Okamoto, Hirotsugu; Miyaji, Kagami

    2018-01-27

    Early extubation in the operating room after congenital open-heart surgery is feasible, but extubation in the intensive care unit after the operation remains common practice at many institutions. The purpose of this study was to evaluate retrospectively the adequacy of our early-extubation strategy and exclusion criteria through analysis based on the Risk Adjustment in Congenital Heart Surgery method (RACHS-1).This retrospective analysis included 359 cases requiring cardiopulmonary bypass (male, 195; female, 164; weight > 3.0 kg; aged 1 month to 18 years). Neonates and preoperatively intubated patients were excluded. Other exclusion criteria included severe preoperative pulmonary hypertension, high-dose catecholamine requirement after cardiopulmonary bypass, delayed sternal closure, laryngomalacia, serious bleeding, and delayed awakening. The early-extubation rates were compared between age groups and RACHS-1 classes.Overall, 83% of cases (298/359) were extubated in the operating room, classified by RACHS-1 categories as follows: 1, 59/59 (100%); 2, 164/200 (84%); 3, 61/78 (78%); and 4-6, 10/22 (45%). The early extubation rate in categories 1-3 (86%, 288/337) was significantly higher than for categories 4-6 (45.5%, 10/22) (P open-heart surgery was feasible based on our criteria, especially for patients in the low RACHS-1 categories, and involves a very low rate of re-intubation.

  20. Does extubation result in haemodynamic instability in patients following coronary artery bypass grafts?

    Science.gov (United States)

    Walthall, H; Ray, S; Robson, D

    2001-10-01

    Coronary heart disease and its management continue to be at the centre of Government health policy. The present political climate demands clinical effectiveness and best practice should be established, while maintaining the philosophy of cost-effectiveness and resource management. These directives have led practitioners to question the care of patients following coronary artery bypass surgery, in particular the role of mechanical ventilation and the subsequent act of extubation. A retrospective study of 89 patients who had coronary artery bypass grafts (emergency and elective) was undertaken, to establish if extubation had a significant effect on the haemodynamic status of patients with variable degrees of left ventricular function (19% with poor left ventricular function). The study found that extubation was achieved within a mean time of 4.97 hours following return from surgery. Extubation resulted in a significant increase in heart rate (P = 0.001), as well as a respiratory acidosis (pCO2: P = 0.000; pH: P = 0.000). However, the stability of the patient was not compromised, with neither mean arterial blood pressure (P = 0.825) nor oxygenation levels (P = 0.267) being significantly altered by extubation. On multivariate analysis, the act of extubation had no significant effect on any of the dependent variables. These results suggest that it is not extubation alone that has an impact on the haemodynamic stability of patients following coronary artery bypass grafts, but that this is indeed multifactorial. Therefore extubation is 'safe' practice for patients with varying degrees of left ventricular function following coronary artery bypass grafts. Limitations of the study are acknowledged.

  1. Impacto de um protocolo de desmame de ventilação mecânica na taxa de falha de extubação em pacientes de difícil desmame Impact of a mechanical ventilation weaning protocol on the extubation failure rate in difficult-to-wean patients

    Directory of Open Access Journals (Sweden)

    Cassiano Teixeira

    2012-06-01

    Full Text Available OBJETIVO: Determinar se a acurácia preditiva do julgamento clínico isolado pode ser melhorada com o uso suplementar de um protocolo de desmame objetivo como ferramenta de suporte para a tomada de decisão. MÉTODOS: Estudo prospectivo multicêntrico de coorte realizado em três UTIs clínicas/cirúrgicas. Foram incluídos no estudo todos os pacientes de difícil desmame (falha no primeiro teste de ventilação espontânea [TVE], sob ventilação mecânica (VM por mais de 48 h, admitidos em uma das UTIs entre janeiro de 2002 e dezembro de 2005. Os pacientes do grupo protocolo (GP foram extubados após teste de tubo T de acordo com um protocolo de desmame e comparados com o grupo de pacientes extubados sem o uso do protocolo (GNP. O desfecho primário foi a taxa de reintubação em até 48 h após a extubação. RESULTADOS: Foram incluídos 731 pacientes - 533 (72,9% no GP e 198 (27,1% no GNP. A taxa global de reintubação foi de 17,9%. As taxas de sucesso da extubação no GP e no GNP foram 86,7% e 69,6%, respectivamente (p OBJECTIVE: To determine whether the predictive accuracy of clinical judgment alone can be improved by supplementing it with an objective weaning protocol as a decision support tool. METHODS: This was a multicenter prospective cohort study carried out at three medical/surgical ICUs. The study involved all consecutive difficult-to-wean ICU patients (failure in the first spontaneous breathing trial [SBT], on mechanical ventilation (MV for more than 48 h, admitted between January of 2002 and December of 2005. The patients in the protocol group (PG were extubated after a T-piece weaning trial and were compared with patients who were otherwise extubated (non-protocol group, NPG. The primary outcome measure was reintubation within 48 h after extubation. RESULTS: We included 731 patients-533 (72.9% and 198 (27.1% in the PG and NPG, respectively. The overall reintubation rate was 17.9%. The extubation success rates in the PG and NPG

  2. Predictive Manufacturing: A Classification Strategy to Predict Product Failures

    DEFF Research Database (Denmark)

    Khan, Abdul Rauf; Schiøler, Henrik; Kulahci, Murat

    2018-01-01

    manufacturing analytics model that employs a big data approach to predicting product failures; third, we illustrate the issue of high dimensionality, along with statistically redundant information; and, finally, our proposed method will be compared against the well-known classification methods (SVM, K......-nearest neighbor, artificial neural networks). The results from real data show that our predictive manufacturing analytics approach, using genetic algorithms and Voronoi tessellations, is capable of predicting product failure with reasonable accuracy. The potential application of this method contributes...... to accurately predicting product failures, which would enable manufacturers to reduce production costs without compromising product quality....

  3. Immediate extubation versus standard postoperative ventilation: Our experience in on pump open heart surgery

    Directory of Open Access Journals (Sweden)

    Srikanta Gangopadhyay

    2010-01-01

    Full Text Available Elective postoperative ventilation in patients undergoing "on pump" open heart surgery has been a standard practice. Ultra fast-track extubation in the operating room is now an accepted technique for "off pump" coronary artery bypass grafting. We tried to incorporate these experiences in on pump open heart surgery and compare the haemodynamic and respiratory parameters in the immediate postoperative period, in patients on standard postoperative ventilation for 8-12 hours. After ethical committee′s approval and informed consent were obtained, 72 patients, between 28 and 45 years of age, undergoing on pump open heart surgery, were selected for our study. We followed same standard anaesthetic, cardiopulmonary bypass (CPB and cardioplegic protocol. Thirty-six patients (Group E were randomly allocated for immediate extubation following operation, after fulfillment of standard extubation criteria. Those who failed to meet these criteria were not extubated and were excluded from the study. The remaining 36 patients (Group V were electively ventilated and extubated after 8-12 hours. Standard monitoring for on pump open heart surgery, including bispectral index was done. The demographic data, surgical procedures, preoperative parameters, aortic cross clamp and cardiopulmonary bypass times were comparable in both the groups. Extubation was possible in more than 88% of cases (n=32 out of 36 cases in Group E and none required reintubation for respiratory insufficiency. Respiratory, haemodynamic parameters and postoperative complications were comparable in both the groups in the postoperative period. Therefore, we can safely conclude that immediate extubation in the operating room after on pump open heart surgery is an alternative acceptable method to avoid postoperative ventilation and its related complications in selected patients.

  4. Efficacy of a new technique - INtubate-RECruit-SURfactant-Extubate - "IN-REC-SUR-E" - in preterm neonates with respiratory distress syndrome: study protocol for a randomized controlled trial

    NARCIS (Netherlands)

    Vento, Giovanni; Pastorino, Roberta; Boni, Luca; Cota, Francesco; Carnielli, Virgilio; Cools, Filip; Dani, Carlo; Mosca, Fabio; Pillow, Jane; Polglase, Graeme; Tagliabue, Paolo; van Kaam, Anton H.; Ventura, Maria Luisa; Tana, Milena; Tirone, Chiara; Aurilia, Claudia; Lio, Alessandra; Ricci, Cinzia; Gambacorta, Alessandro; Consigli, Chiara; D'Onofrio, Danila; Gizzi, Camilla; Massenzi, Luca; Cardilli, Viviana; Casati, Alessandra; Bottino, Roberto; Pontiggia, Federica; Ciarmoli, Elena; Martinelli, Stefano; Ilardi, Laura; Colnaghi, Mariarosa; Matassa, Piero Giuseppe; Vendettuoli, Valentina; Villani, Paolo; Fusco, Francesca; Gazzolo, Diego; Ricotti, Alberto; Ferrero, Federica; Stasi, Ilaria; Magaldi, Rosario; Maffei, Gianfranco; Presta, Giuseppe; Perniola, Roberto; Messina, Francesco; Montesano, Giovanna; Poggi, Chiara; Giordano, Lucio; Roma, Enza; Grassia, Carolina; Ausanio, Gaetano; Sandri, Fabrizio; Mescoli, Giovanna; Giura, Francesco; Garani, Giampaolo; Solinas, Agostina; Lucente, Maria; Nigro, Gabriella; del Vecchio, Antonello; Petrillo, Flavia; Orfeo, Luigi; Grappone, Lidia; Quartulli, Lorenzo; Scorrano, Antonio; Messner, Hubert; Staffler, Alex; Gargano, Giancarlo; Balestri, Eleonora; Nobile, Stefano; Cacace, Caterina; Meli, Valerio; Dallaglio, Sara; Pasqua, Betta; Mattia, Loretta; Gitto, Eloisa; Vitaliti, Marcello; Re, Maria Paola; Vedovato, Stefania; Grison, Alessandra; Berardi, Alberto; Torcetta, Francesco; Guidotti, Isotta; di Fabio, Sandra; Maranella, Eugenia; Mondello, Isabella; Visentin, Stefano; Tormena, Francesca

    2016-01-01

    Although beneficial in clinical practice, the INtubate-SURfactant-Extubate (IN-SUR-E) method is not successful in all preterm neonates with respiratory distress syndrome, with a reported failure rate ranging from 19 to 69 %. One of the possible mechanisms responsible for the unsuccessful IN-SUR-E

  5. The Outcome and Predictors of Failed Extubation in Intensive Care Patients—The  Elderly is an Important Predictor

    Directory of Open Access Journals (Sweden)

    Ai-Chin Cheng

    2011-12-01

    Conclusion: Our study indicated that patients with failed extubation experienced significantly increased admission expenditure, increased tracheostomy rate, and higher hospital mortality. Advanced age should be considered an important risk factor for failed extubation and overall mortality when planning extubation in critically ill ICU patients.

  6. Utilizing a Collaborative Learning Model to Promote Early Extubation Following Infant Heart Surgery.

    Science.gov (United States)

    Mahle, William T; Nicolson, Susan C; Hollenbeck-Pringle, Danielle; Gaies, Michael G; Witte, Madolin K; Lee, Eva K; Goldsworthy, Michelle; Stark, Paul C; Burns, Kristin M; Scheurer, Mark A; Cooper, David S; Thiagarajan, Ravi; Sivarajan, V Ben; Colan, Steven D; Schamberger, Marcus S; Shekerdemian, Lara S

    2016-10-01

    To determine whether a collaborative learning strategy-derived clinical practice guideline can reduce the duration of endotracheal intubation following infant heart surgery. Prospective and retrospective data collected from the Pediatric Heart Network in the 12 months pre- and post-clinical practice guideline implementation at the four sites participating in the collaborative (active sites) compared with data from five Pediatric Heart Network centers not participating in collaborative learning (control sites). Ten children's hospitals. Data were collected for infants following two-index operations: 1) repair of isolated coarctation of the aorta (birth to 365 d) and 2) repair of tetralogy of Fallot (29-365 d). There were 240 subjects eligible for the clinical practice guideline at active sites and 259 subjects at control sites. Development and application of early extubation clinical practice guideline. After clinical practice guideline implementation, the rate of early extubation at active sites increased significantly from 11.7% to 66.9% (p collaborative learning strategy designed clinical practice guideline significantly increased the rate of early extubation with no change in the rate of reintubation. The early extubation clinical practice guideline did not significantly change postoperative ICU length of stay.

  7. Comparison of dexmedetomidine and lignocaine on attenuation of airway and pressor responses during tracheal extubation

    Directory of Open Access Journals (Sweden)

    Vivek Bharti Sharma

    2014-01-01

    Full Text Available Background: Haemodynamic stability and rapid emergence after general anaesthesia used in spinal surgery is a common practice, the goal of which is to permit early neurological motor and sensory examination. Extubation is almost always associated with hypertension, increased airway response and arrhythmias. We have compared the effects of the α-2 agonist Dexmedetomidine and Lignocaine given at the end of the procedure on attenuation of airway and pressor responses following tracheal extubation. This study is a randomised, placebo-controlled, double-blinded study. Materials and Methods: Sixty ASA I-III patients, aged 18-70 years, scheduled to undergo spinal surgery at the level of thoracic, lumbar or sacral region were randomly divided into three groups. Balanced general anaesthesia comprising standard procedures and drugs were used for monitoring, induction and maintenance. At the last skin suture, inhalation anaesthetic was discontinued. After turning the patient supine and return of spontaneous efforts, in Group D Dexmedetomidine 0.5 μg/kg, in Group L Lignocaine 1.5 mg/kg and in Group P normal saline (10 ml were administered as bolus intravenously over 60 seconds. Systolic, diastolic and mean arterial pressures and heart rate were recorded before intravenous administration and also every minute for 3 minutes, at 5, 10 and 15 minutes post-extubation. Duration of emergence and extubation were noted and attenuation of airway response and quality of extubation was evaluated on cough grading. Results: Mean arterial pressures and heart rate were higher in Group L and Group P than in Group D but not statistically significant. The duration of emergence, extubation and recovery were comparable in all the groups (P > 0.05. Extubation Quality Scores was 1 in 80%, 2 in 20% in Group D; in Group L, the quality scores were 1 for 55%, 2 for 45% and I Group P 1 for 35%, 2 for 45% and 3 for 20% of the patients. The requirement of rescue analgesia was also less

  8. Factors Influencing the Predictive Power of Models for Predicting Mortality and/or Heart Failure Hospitalization in Patients With Heart Failure

    NARCIS (Netherlands)

    Ouwerkerk, Wouter; Voors, Adriaan A.; Zwinderman, Aeilko H.

    2014-01-01

    The present paper systematically reviews and compares existing prediction models in order to establish the strongest variables, models, and model characteristics in patients with heart failure predicting outcome. To improve decision making accurately predicting mortality and heart-failure

  9. Relationship between pre-extubation positive endexpiratory pressure and oxygenation after coronary artery bypass grafting

    Directory of Open Access Journals (Sweden)

    Reijane Oliveira Lima

    2015-08-01

    Full Text Available Abstract Introduction After removal of endotracheal tube and artificial ventilation, ventilatory support should be continued, offering oxygen supply to ensure an arterial oxygen saturation close to physiological. Objective: The aim of this study was to investigate the effects of positive-end expiratory pressure before extubation on the oxygenation indices of patients undergoing coronary artery bypass grafting. Methods: A randomized clinical trial with seventy-eight patients undergoing coronary artery bypass grafting divided into three groups and ventilated with different positive-end expiratory pressure levels prior to extubation: Group A, 5 cmH2O (n=32; Group B, 8 cmH2O (n=26; and Group C, 10 cmH2O (n=20. Oxygenation index data were obtained from arterial blood gas samples collected at 1, 3, and 6 h after extubation. Patients with chronic pulmonary disease and those who underwent off-pump, emergency, or combined surgeries were excluded. For statistical analysis, we used Shapiro-Wilk, G, Kruskal-Wallis, and analysis of variance tests and set the level of significance at P<0.05. Results Groups were homogenous with regard to demographic, clinical, and surgical variables. There were no statistically significant differences between groups in the first 6 h after extubation with regard to oxygenation indices and oxygen therapy utilization. Conclusion: In this sample of patients undergoing coronary artery bypass grafting, the use of different positive-end expiratory pressure levels before extubation did not affect gas exchange or oxygen therapy utilization in the first 6 h after endotracheal tube removal.

  10. Failure Prediction And Detection In Cloud Datacenters

    Directory of Open Access Journals (Sweden)

    Purvil Bambharolia

    2017-09-01

    Full Text Available Cloud computing is a novel technology in the field of distributed computing. Usage of Cloud computing is increasing rapidly day by day. In order to serve the customers and businesses satisfactorily fault occurring in datacenters and servers must be detected and predicted efficiently in order to launch mechanisms to tolerate the failures occurred. Failure in one of the hosted datacenters may propagate to other datacenters and make the situation worse. In order to prevent such situations one can predict a failure proliferating throughout the cloud computing system and launch mechanisms to deal with it proactively. One of the ways to predict failures is to train a machine to predict failure on the basis of messages or logs passed between various components of the cloud. In the training session the machine can identify certain message patterns relating to failure of data centers. Later on the machine can be used to check whether a certain group of message logs follow such patterns or not. Moreover each cloud server can be defined by a state which indicates whether the cloud is running properly or is facing some failure. Parameters such as CPU usage memory usage etc. can be maintained for each of the servers. Using this parameters we can add a layer of detection where in we develop a decision tree based on these parameters which can classify whether the passed in parameters to the decision tree indicate failure state or proper state.

  11. The function and failure of sensory predictions.

    Science.gov (United States)

    Bansal, Sonia; Ford, Judith M; Spering, Miriam

    2018-04-23

    Humans and other primates are equipped with neural mechanisms that allow them to automatically make predictions about future events, facilitating processing of expected sensations and actions. Prediction-driven control and monitoring of perceptual and motor acts are vital to normal cognitive functioning. This review provides an overview of corollary discharge mechanisms involved in predictions across sensory modalities and discusses consequences of predictive coding for cognition and behavior. Converging evidence now links impairments in corollary discharge mechanisms to neuropsychiatric symptoms such as hallucinations and delusions. We review studies supporting a prediction-failure hypothesis of perceptual and cognitive disturbances. We also outline neural correlates underlying prediction function and failure, highlighting similarities across the visual, auditory, and somatosensory systems. In linking basic psychophysical and psychophysiological evidence of visual, auditory, and somatosensory prediction failures to neuropsychiatric symptoms, our review furthers our understanding of disease mechanisms. © 2018 New York Academy of Sciences.

  12. Uncertainties in container failure time predictions

    International Nuclear Information System (INIS)

    Williford, R.E.

    1990-01-01

    Stochastic variations in the local chemical environment of a geologic waste repository can cause corresponding variations in container corrosion rates and failure times, and thus in radionuclide release rates. This paper addresses how well the future variations in repository chemistries must be known in order to predict container failure times that are bounded by a finite time period within the repository lifetime. Preliminary results indicate that a 5000 year scatter in predicted container failure times requires that repository chemistries be known to within ±10% over the repository lifetime. These are small uncertainties compared to current estimates. 9 refs., 3 figs

  13. Detecting failure of climate predictions

    Science.gov (United States)

    Runge, Michael C.; Stroeve, Julienne C.; Barrett, Andrew P.; McDonald-Madden, Eve

    2016-01-01

    The practical consequences of climate change challenge society to formulate responses that are more suited to achieving long-term objectives, even if those responses have to be made in the face of uncertainty1, 2. Such a decision-analytic focus uses the products of climate science as probabilistic predictions about the effects of management policies3. Here we present methods to detect when climate predictions are failing to capture the system dynamics. For a single model, we measure goodness of fit based on the empirical distribution function, and define failure when the distribution of observed values significantly diverges from the modelled distribution. For a set of models, the same statistic can be used to provide relative weights for the individual models, and we define failure when there is no linear weighting of the ensemble models that produces a satisfactory match to the observations. Early detection of failure of a set of predictions is important for improving model predictions and the decisions based on them. We show that these methods would have detected a range shift in northern pintail 20 years before it was actually discovered, and are increasingly giving more weight to those climate models that forecast a September ice-free Arctic by 2055.

  14. Multivariable analysis of anesthetic factors associated with time to extubation in dogs.

    Science.gov (United States)

    Kleine, Stephanie; Hofmeister, Erik; Egan, Katrina

    2014-12-01

    The purpose of this study was to identify factors that prolong the time to extubation in dogs. Anesthetic records of 900 dogs at a university teaching hospital were searched. Multiple linear regression was used to compare independent predictors (patient demographics, anesthetic and intraoperative variables) with the dependent variable (time to extubation). Induction with propofol (P temperature (P = 0.0000), and by 0.096 minutes for every 1 minute increase in anesthetic duration (P = 0.000). Anesthetic variables, which can be manipulated by the anesthetist, include choice of premedication and induction drugs, hypothermia, and duration of anesthesia. Published by Elsevier Ltd.

  15. Prediction of failure modes for concrete nuclear-containment buildings

    International Nuclear Information System (INIS)

    Butler, T.A.

    1982-01-01

    The failure modes and associated failure pressures for two common generic types of PWR containments are predicted. One building type is a lightly reinforced, posttensioned structure represented by the Zion nuclear reactor containment. The other is the normally reinforced Indian Point containment. Two-dimensional models of the buildings developed using the finite element method are used to predict the failure modes and failure pressures. Predicted failure modes for both containments involve loss of structural integrity at the intersection of the cylindrical sidewall with the base slab

  16. Performance of immunological response in predicting virological failure.

    Science.gov (United States)

    Ingole, Nayana; Mehta, Preeti; Pazare, Amar; Paranjpe, Supriya; Sarkate, Purva

    2013-03-01

    In HIV-infected individuals on antiretroviral therapy (ART), the decision on when to switch from first-line to second-line therapy is dictated by treatment failure, and this can be measured in three ways: clinically, immunologically, and virologically. While viral load (VL) decreases and CD4 cell increases typically occur together after starting ART, discordant responses may be seen. Hence the current study was designed to determine the immunological and virological response to ART and to evaluate the utility of immunological response to predict virological failure. All treatment-naive HIV-positive individuals aged >18 years who were eligible for ART were enrolled and assessed at baseline, 6 months, and 12 months clinically and by CD4 cell count and viral load estimations. The patients were categorized as showing concordant favorable (CF), immunological only (IO), virological only (VO), and concordant unfavorable responses (CU). The efficiency of immunological failure to predict virological failure was analyzed across various levels of virological failure (VL>50, >500, and >5,000 copies/ml). At 6 months, 87(79.81%), 7(5.5%), 13 (11.92%), and 2 (1.83%) patients and at 12 months 61(69.3%), 9(10.2%), 16 (18.2%), and 2 (2.3%) patients had CF, IO, VO, and CU responses, respectively. Immunological failure criteria had a very low sensitivity (11.1-40%) and positive predictive value (8.3-25%) to predict virological failure. Immunological criteria do not accurately predict virological failure resulting in significant misclassification of therapeutic responses. There is an urgent need for inclusion of viral load testing in the initiation and monitoring of ART.

  17. Methods, apparatus and system for notification of predictable memory failure

    Energy Technology Data Exchange (ETDEWEB)

    Cher, Chen-Yong; Andrade Costa, Carlos H.; Park, Yoonho; Rosenburg, Bryan S.; Ryu, Kyung D.

    2017-01-03

    A method for providing notification of a predictable memory failure includes the steps of: obtaining information regarding at least one condition associated with a memory; calculating a memory failure probability as a function of the obtained information; calculating a failure probability threshold; and generating a signal when the memory failure probability exceeds the failure probability threshold, the signal being indicative of a predicted future memory failure.

  18. BANK FAILURE PREDICTION WITH LOGISTIC REGRESSION

    Directory of Open Access Journals (Sweden)

    Taha Zaghdoudi

    2013-04-01

    Full Text Available In recent years the economic and financial world is shaken by a wave of financial crisis and resulted in violent bank fairly huge losses. Several authors have focused on the study of the crises in order to develop an early warning model. It is in the same path that our work takes its inspiration. Indeed, we have tried to develop a predictive model of Tunisian bank failures with the contribution of the binary logistic regression method. The specificity of our prediction model is that it takes into account microeconomic indicators of bank failures. The results obtained using our provisional model show that a bank's ability to repay its debt, the coefficient of banking operations, bank profitability per employee and leverage financial ratio has a negative impact on the probability of failure.

  19. Use of positive pressure in preoperative and intraoperative of bariatric surgery and its effect on the time of extubation

    Directory of Open Access Journals (Sweden)

    Letícia Baltieri

    2015-04-01

    Full Text Available BACKGROUND AND OBJECTIVE: To investigate the influence of intraoperative and preoperative positive pressure in the time of extubation in patients undergoing bariatric surgery. METHOD: Randomized clinical trial, in which 40 individuals with a body mass index between 40 and 55 kg/m2, age between 25 and 55 years, nonsmokers, underwent bariatric surgery type Roux-en-Y gastric bypass by laparotomy and with normal preoperative pulmonary function were randomized into the following groups: G-pre (n = 10: individuals who received treatment with noninvasive positive pressure before surgery for 1 h; G-intra (n = 10: individuals who received positive end-expiratory pressure of 10 cm H2O throughout the surgical procedure; and G-control (n = 20: not received any preoperative or intraoperative intervention. Following were recorded: time between induction of anesthesia and extubation, between the end of anesthesia and extubation, duration of mechanical ventilation, and time between extubation and discharge from the post-anesthetic recovery. RESULTS: There was no statistical difference between groups. However, when applied to the Cohen coefficient, the use of positive end-expiratory pressure of 10 cm H2O during surgery showed a large effect on the time between the end of anesthesia and extubation. About this same time, the treatment performed preoperatively showed moderate effect. CONCLUSION: The use of positive end-expiratory pressure of 10 cm H2O in the intraoperative and positive pressure preoperatively, influenced the time of extubation of patients undergoing bariatric surgery.

  20. Strain limit criteria to predict failure

    International Nuclear Information System (INIS)

    Flanders, H.E.

    1995-01-01

    In recent years extensive effort has been expended to qualify existing structures for conditions that are beyond the original design basis. Determination of the component failure load is useful for this type of evaluation. This paper presents criteria based upon strain limits to predict the load at failure. The failure modes addressed are excessive plastic deformations, localized plastic strains, and structural instability. The effects of analytical method sophistication, as built configurations, material properties degradation, and stress state are addressed by the criteria

  1. Plan to Have No Unplanned: A Collaborative, Hospital-Based Quality-Improvement Project to Reduce the Rate of Unplanned Extubations in the Pediatric ICU.

    Science.gov (United States)

    Tripathi, Sandeep; Nunez, Denise J; Katyal, Chaavi; Ushay, H Michael

    2015-08-01

    Although under-reported and understudied, unplanned extubations carry a significant risk of patient harm and even death. They are an important yardstick of quality control of care of intubated patients in the ICU. A unit-based risk assessment and multidisciplinary approach is required to decrease the incidence of unplanned extubations. As part of a quality-improvement initiative of Children's Hospital at Montefiore, all planned and unplanned extubations in a multidisciplinary 20-bed pediatric ICU were evaluated over a 12-month period (January to December 2010). At the end of 6 months, an interim analysis was performed, and high-risk patient groups and patient care factors were identified. These factors were targeted in the second phase of the project. Over this period, there were a total of 267 extubations, of which 231 (87%) were planned extubations and 36 (13%) were unplanned. A patient care policy targeting the risk factors was instituted, along with extensive nursing and other personnel education in the second phase. As a result of this intervention, the unplanned extubation rate in the pediatric ICU decreased from 3.55 to 2.59/100 intubation days. All subjects who had an unplanned extubation during nursing procedures or transport required re-intubation, whereas none of the unplanned extubations during ventilator weaning required re-intubation. A targeted approach based on unit-specific risk factors is most effective in quality-improvement projects. A specific policy for sedation and weaning can be very helpful in managing intubated patients and preventing unintended harm. Copyright © 2015 by Daedalus Enterprises.

  2. [Prediction of mortality in patients with acute hepatic failure].

    Science.gov (United States)

    Eremeeva, L F; Berdnikov, A P; Musaeva, T S; Zabolotskikh, I B

    2013-01-01

    The article deals with a study of 243 patients (from 18 to 65 years old) with acute hepatic failure. Purpose of the study was to evaluate the predictive capability of severity scales APACHE III, SOFA, MODS, Child-Pugh and to identify mortality predictors in patients with acute hepatic failure. Results; The best predictive ability in patients with acute hepatic failure and multiple organ failure had APACHE III and SOFA scales. The strongest mortality predictors were: serum creatinine > 132 mmol/L, fibrinogen < 1.4 g/L, Na < 129 mmol/L.

  3. Avaliação do teste de respiração espontânea na extubação de neonatos pré-termo Spontaneous breathing trial evaluation in preterm newborns extubation

    Directory of Open Access Journals (Sweden)

    Lívia Barboza Andrade

    2010-06-01

    workload. The spontaneous breathing trial (SBT, performed immediately before extubation, can provide useful information on the patient's spontaneous breathing ability. This study aimed to assess the SBT effectiveness for extubation success prediction in mechanically ventilated preterm infants. METHODS: After Ethics Committee approval, an observational, longitudinal, prospective study was conducted. A sample of 60 preterm infants compliant with the weaning criteria was categorized in two groups: 'SBT' group (n=30, with the patients who underwent 30 minutes spontaneous breathing trial (SBT with continuous positive pressure airway (CPAP, and the control group (n=30 where the extubation was performed without spontaneous breathing trial. The heart rate (HR, respiratory rate (RR, pulse oxymetry oxygen saturation (SpO2 and the Silverman-Andersen score were recorded before and 10, 20 and 30 minutes after the spontaneous breathing trial. Were also assessed for both groups, and versus extubation success or failure, the weight, gestational age, Apgar score, mean airway pressure, inspired oxygen concentration, and tracheal tube time. The Chi-square test was used for categorical variables and the Mann-Whitney test for non-normal distribution. Extubation success was defined as a 48 hours period with no reintubation requirement. RESULTS: No significant differences were identified between the groups for the analyzed variables, except for the mean airway pressure. A significant association was shown between spontaneous breathing trial and successful extubation. CONCLUSION: The significant association between SBT and extubation success may contribute for prediction of successful weaning in preterm infants.

  4. The Effect of Progressive Muscle Relaxation Exercises After Endotracheal Extubation on Vital Signs and Anxiety Level in Open Heart Surgery Patients

    Directory of Open Access Journals (Sweden)

    Özlem İbrahimoğlu

    2017-12-01

    Full Text Available Objective: The purpose of this study was to examine the effects of the exercises of progressive muscle relaxation (PMR on vital signs and anxiety level after endotracheal extubation in open heart surgery. Materials and Methods: This study was carried out as quasi-experimental, pre-test, and post-test with a control group. The study recruited 30 experimental and 30 control group open heart surgery patients, who met the inclusion criteria, from a cardiac and vascular surgery clinic of a university hospital. PMR exercises, which were taught before the surgery, were implemented after the surgery in the intensive care unit simultaneously with endotracheal extubation. The vital signs of the patients were monitored for the first 30 min. The anxiety levels were measured after 30 min of extubation with state anxiety inventory. Results: The lower rates of heartbeat, breathing, arterial blood pressure, and anxiety were observed in the experimental group in all measurements (first 30 min after endotracheal extubation, and the differences were statistically significant in favor of the experimental group (p<0.05. Conclusion: The study showed that the relaxation exercises after endotracheal extubation in open heart surgery patients was effective in improving vital signs and reducing anxiety level.

  5. Review on failure prediction techniques of composite single lap joint

    Energy Technology Data Exchange (ETDEWEB)

    Ab Ghani, A.F., E-mail: ahmadfuad@utem.edu.my; Rivai, Ahmad, E-mail: ahmadrivai@utem.edu.my [Faculty of Mechanical Engineering, Locked Bag 1200, Hang Tuah Jaya, 75450 Ayer Keroh, Melaka (Malaysia)

    2016-03-29

    Adhesive bonding is the most appropriate joining method in construction of composite structures. The use of reliable design and prediction technique will produce better performance of bonded joints. Several papers from recent papers and journals have been reviewed and synthesized to understand the current state of the art in this area. It is done by studying the most relevant analytical solutions for composite adherends with start of reviewing the most fundamental ones involving beam/plate theory. It is then extended to review single lap joint non linearity and failure prediction and finally on the failure prediction on composite single lap joint. The review also encompasses the finite element modelling part as tool to predict the elastic response of composite single lap joint and failure prediction numerically.

  6. Review on failure prediction techniques of composite single lap joint

    International Nuclear Information System (INIS)

    Ab Ghani, A.F.; Rivai, Ahmad

    2016-01-01

    Adhesive bonding is the most appropriate joining method in construction of composite structures. The use of reliable design and prediction technique will produce better performance of bonded joints. Several papers from recent papers and journals have been reviewed and synthesized to understand the current state of the art in this area. It is done by studying the most relevant analytical solutions for composite adherends with start of reviewing the most fundamental ones involving beam/plate theory. It is then extended to review single lap joint non linearity and failure prediction and finally on the failure prediction on composite single lap joint. The review also encompasses the finite element modelling part as tool to predict the elastic response of composite single lap joint and failure prediction numerically.

  7. Bedside screen for oral cavity structure, salivary flow, and vocal production over the 14days following endotracheal extubation.

    Science.gov (United States)

    Chen, Cheryl Chia-Hui; Wu, Kuo-Hsiang; Ku, Shih-Chi; Chan, Ding-Cheng; Lee, Jang-Jaer; Wang, Tyng-Guey; Hsiao, Tzu-Yu

    2018-06-01

    To describe the sequelae of oral endotracheal intubation by evaluating prevalence rates of structural injury, hyposalivation, and impaired vocal production over 14days following extubation. Consecutive adults (≥20years, N=114) with prolonged (≥48h) endotracheal intubation were enrolled from medical intensive care units at a university hospital. Participants were assessed by trained nurses at 2, 7, and 14days after extubation, using a standardized bedside screening protocol. Within 48-hour postextubation, structural injuries were common, with 51% having restricted mouth opening. Unstimulated salivary flow was reduced in 43%. For vocal production, 51% had inadequate breathing support for phonation, dysphonia was common (94% had hoarseness and 36% showed reduced efficiency of vocal fold closure), and >40% had impaired articulatory precision. By 14days postextubation, recovery was noted in most conditions, but reduced efficiency of vocal fold closure persisted. Restricted mouth opening (39%) and reduced salivary flow (34%) remained highly prevalent. After extubation, restricted mouth opening, reduced salivary flow, and dysphonia were common and prolonged in recovery. Reduced efficiency of vocal cord closure persisted at 14days postextubation. The extent and duration of these sequelae remind clinicians to screen for them up to 2weeks after extubation. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Predicting water main failures using Bayesian model averaging and survival modelling approach

    International Nuclear Information System (INIS)

    Kabir, Golam; Tesfamariam, Solomon; Sadiq, Rehan

    2015-01-01

    To develop an effective preventive or proactive repair and replacement action plan, water utilities often rely on water main failure prediction models. However, in predicting the failure of water mains, uncertainty is inherent regardless of the quality and quantity of data used in the model. To improve the understanding of water main failure, a Bayesian framework is developed for predicting the failure of water mains considering uncertainties. In this study, Bayesian model averaging method (BMA) is presented to identify the influential pipe-dependent and time-dependent covariates considering model uncertainties whereas Bayesian Weibull Proportional Hazard Model (BWPHM) is applied to develop the survival curves and to predict the failure rates of water mains. To accredit the proposed framework, it is implemented to predict the failure of cast iron (CI) and ductile iron (DI) pipes of the water distribution network of the City of Calgary, Alberta, Canada. Results indicate that the predicted 95% uncertainty bounds of the proposed BWPHMs capture effectively the observed breaks for both CI and DI water mains. Moreover, the performance of the proposed BWPHMs are better compare to the Cox-Proportional Hazard Model (Cox-PHM) for considering Weibull distribution for the baseline hazard function and model uncertainties. - Highlights: • Prioritize rehabilitation and replacements (R/R) strategies of water mains. • Consider the uncertainties for the failure prediction. • Improve the prediction capability of the water mains failure models. • Identify the influential and appropriate covariates for different models. • Determine the effects of the covariates on failure

  9. Failure prediction using machine learning and time series in optical network.

    Science.gov (United States)

    Wang, Zhilong; Zhang, Min; Wang, Danshi; Song, Chuang; Liu, Min; Li, Jin; Lou, Liqi; Liu, Zhuo

    2017-08-07

    In this paper, we propose a performance monitoring and failure prediction method in optical networks based on machine learning. The primary algorithms of this method are the support vector machine (SVM) and double exponential smoothing (DES). With a focus on risk-aware models in optical networks, the proposed protection plan primarily investigates how to predict the risk of an equipment failure. To the best of our knowledge, this important problem has not yet been fully considered. Experimental results showed that the average prediction accuracy of our method was 95% when predicting the optical equipment failure state. This finding means that our method can forecast an equipment failure risk with high accuracy. Therefore, our proposed DES-SVM method can effectively improve traditional risk-aware models to protect services from possible failures and enhance the optical network stability.

  10. Effect of High-Flow Nasal Cannula versus Conventional Oxygen Therapy for Patients with Thoracoscopic Lobectomy after Extubation

    Directory of Open Access Journals (Sweden)

    Yuetian Yu

    2017-01-01

    Full Text Available Objective. To investigate whether high-flow nasal cannula (HFNC oxygen therapy is superior to conventional oxygen therapy for reducing hypoxemia and postoperative pulmonary complications (PPC in patients with thoracoscopic lobectomy after extubation. Methods. Patients with intermediate to high risk for PPC were enrolled in this study. Subjects were randomly assigned to HFNC group (HFNCG or conventional oxygen group (COG following extubation. Arterial blood samples were collected after extubation at 1, 2, 6, 12, 24, 48, and 72 h. Patients with postoperative hypoxemia and PPC were recorded. Adverse events were also documented. Results. Totally 110 patients were randomly assigned to HFNCG (n=56 and COG (n=54. The occurrence rate of hypoxemia in COG was twice more than that in HFNCG (29.62% versus 12.51%, P0.05. Adverse effects as throat and nasal pain occurred more frequently in COG. Conclusions. HFNC application improves oxygenation and reduces the risk of reintubation following thoracoscopic lobectomy but cannot decrease the incidence of PPC.

  11. Alleviating stress response to tracheal extubation in neurosurgical patients: A comparative study of two infusion doses of dexmedetomidine

    Directory of Open Access Journals (Sweden)

    Ankur Luthra

    2017-01-01

    Full Text Available Background: Tracheal extubation is almost always associated with increase in sympathoadrenal activity may result in hypertension, tachycardia, and arrhythmias. Attempts have been made to oppose the pressor response by the use of various drugs. Dexmedetomidine decreases norepinephrine which reduces the blood pressure and the heart rate (HR. We hypothesize that the infusion of dexmedetomidine may produce more stable hemodynamics during extubation as compared to boluses. Materials and Methods: Ninety adult patients aged 18–65 years, the American Society of Anesthesiologists Grade I–II undergoing intracranial surgeries for various neurologic problem at All India Institute of Medical Sciences were enrolled in this randomized controlled trial. Primary Objectives: (1 To observe the hemodynamic changes (HR and mean arterial pressure [MAP] and airway responses during tracheal extubation following two infusion doses of dexmedetomidine. Secondary Objectives: (1 Time to emergence and time to tracheal extubation, (2 Early postoperative complications such as laryngospasm and bronchospasm, and (3 adverse effects of the study drug. Patients were assigned into three groups – (1 Group D0.2 – 0.2 μg/kg/h diluted to 50 ml, (2 Group D0.4 – 0.4 μg/kg/h diluted to 50 ml and Group P (Placebo – 0.9% NS 50 ml. The hemodynamics including the HR and MAP were recorded just before the loading dose of the study drug and then were recorded every 5 min till the infusion was stopped at tracheal extubation and every 1 min till 10 min postextubation. In addition, the airway, respiratory and cardiovascular complications along with postoperative nausea and vomiting, shivering, cough grading, Aldrete score, Ramsay sedation scale, and intraoperative awareness were recorded. Statistical Analysis: Continuous variables such as HR and MAP were analyzed using analysis of variance and categorical variables were analyzed using the Chi-square test. Results: Patient demographics

  12. Failure prediction of low-carbon steel pressure vessel and cylindrical models

    International Nuclear Information System (INIS)

    Zhang, K.D.; Wang, W.

    1987-01-01

    The failure loads predicted by failure assessment methods (namely the net-section stress criterion; the EPRI engineering approach for elastic-plastic analysis; the CEGB failure assessment route; the modified R6 curve by Milne for strain hardening; and the failure assessment curve based on J estimation by Ainsworth) have been compared with burst test results on externally, axially sharp notched pressure vessel and open-ended cylinder models made from typical low-carbon steel St45 seamless tube which has a transverse true stress-strain curve of straight-line and parabola type and a high value of ultimate strength to yield. It was concluded from the comparison that whilst the net-section stress criterion and the CEGB route did not give conservative predictions, Milne's modified curve did give a conservative and good prediction; Ainsworth's curve gave a fairly conservative prediction; and EPRI solutions also could conditionally give a good prediction but the conditions are still somewhat uncertain. It is suggested that Milne's modified R6 curve is used in failure assessment of low-carbon steel pressure vessels. (author)

  13. Evolutionary neural network modeling for software cumulative failure time prediction

    International Nuclear Information System (INIS)

    Tian Liang; Noore, Afzel

    2005-01-01

    An evolutionary neural network modeling approach for software cumulative failure time prediction based on multiple-delayed-input single-output architecture is proposed. Genetic algorithm is used to globally optimize the number of the delayed input neurons and the number of neurons in the hidden layer of the neural network architecture. Modification of Levenberg-Marquardt algorithm with Bayesian regularization is used to improve the ability to predict software cumulative failure time. The performance of our proposed approach has been compared using real-time control and flight dynamic application data sets. Numerical results show that both the goodness-of-fit and the next-step-predictability of our proposed approach have greater accuracy in predicting software cumulative failure time compared to existing approaches

  14. Failure prediction for Crack-in-Corrosion defects in natural gas transmission pipelines

    International Nuclear Information System (INIS)

    Bedairi, B.; Cronin, D.; Hosseini, A.; Plumtree, A.

    2012-01-01

    Cracks occurring coincidentally with corrosion (Crack-in-Corrosion or CIC), represent a new hybrid defect in pipelines that are not directly addressed in the current codes or assessment methods. To understand the failure response of these defects, the finite element method using an elastic–plastic fracture mechanics approach was applied to predict the failure pressures of comparable crack, corrosion and CIC defects in 508 mm diameter pipe with 5.7 mm wall thickness. Failure pressure predictions were made based on measured tensile, Charpy impact and J testing data, and validated using experimental rupture tests. Plastic collapse was predicted for corrosion and crack defects using the critical strength based on the material tensile strength, whereas fracture was predicted using the measured J 0.2 value. The model predictions were found to be conservative for the CIC defects (17.4% on average), 12.4% conservative for crack-only defects, and 3.2% conservative for corrosion defects compared to the experimental tests, demonstrating the applicability of the material-based failure criteria. For the defects considered in this study, all were predicted to fail by plastic collapse. The finite element method provided less conservative predictions than existing corrosion or crack-based analytical methods. Highlights: ► Cracks occurring coincidentally with corrosion represent a new hybrid defect in pipelines. ► Existing methods for prediction corrosion and crack defect failure pressures are conservative. ► The FE method can provide improved prediction of rupture pressure using actual material properties. ► Failure was predicted using FE with a critical stress for plastic collapse and J value for fracture. ► FE failure pressure predictions for crack in corrosion defects were 17% conservative on average.

  15. Bayesian state prediction of wind turbine bearing failure

    DEFF Research Database (Denmark)

    Herp, Jürgen; Ramezani, Mohammad H.; Bach-Andersen, Martin

    2017-01-01

    A statistical approach to abstract and predict turbine states in an online manner has been developed. Online inference is performed on temperature measurement residuals to predict the failure state δn steps ahead of time. In this framework a case study is performed showing the ability to predict...

  16. Optimisation of the link volume for weakest link failure prediction in NBG-18 nuclear graphite

    International Nuclear Information System (INIS)

    Hindley, Michael P.; Groenwold, Albert A.; Blaine, Deborah C.; Becker, Thorsten H.

    2014-01-01

    This paper describes the process for approximating the optimal size of a link volume required for weakest link failure calculation in nuclear graphite, with NBG-18 used as an example. As part of the failure methodology, the link volume is defined in terms of two grouping criteria. The first criterion is a factor of the maximum grain size and the second criterion is a function of an equivalent stress limit. A methodology for approximating these grouping criteria is presented. The failure methodology employs finite element analysis (FEA) in order to predict the failure load, at 50% probability of failure. The average experimental failure load, as determined for 26 test geometries, is used to evaluate the accuracy of the weakest link failure calculations. The influence of the two grouping criteria on the failure load prediction is evaluated by defining an error in prediction across all test cases. Mathematical optimisation is used to find the minimum error across a range of test case failure predictions. This minimum error is shown to deliver the most accurate failure prediction across a whole range of components, although some test cases in the range predict conservative failure load. The mathematical optimisation objective function is penalised to account for non-conservative prediction of the failure load for any test case. The optimisation is repeated and a link volume found for conservative failure prediction. The failure prediction for each test case is evaluated, in detail, for the proposed link volumes. Based on the analysis, link design volumes for NBG-18 are recommended for either accurate or conservative failure prediction

  17. Spontaneous migration of central venous catheter tip following extubation

    Directory of Open Access Journals (Sweden)

    Balaji Prabaharan

    2014-01-01

    Full Text Available Migration of the tip of central venous catheters is not an uncommon event and the mechanism for this is not clear. Increased intrathoracic pressure due to coughing, sneezing or weight lifting, changing the body position or physical movements such as abduction or adduction of the arms is thought to be the cause of such migration. We present here a case of a patient with a port catheter tip that migrated from the left subclavian to the superior vene cava following extubation.

  18. Efficiency of Noninvasive Ventilation in Acute Heart Failure

    Directory of Open Access Journals (Sweden)

    Z. Z. Nadiradze

    2008-01-01

    Full Text Available Objective: to evaluate the efficiency of noninvasive supporting ventilation in patients with acute cardiorespiratory failure in the early postoperative period after cardiac surgery under extracorporeal circulation. Methods. Case histories of patients operated on the heart under extracorporeal circulation, who postoperatively developed acute car-diorespiratory failure requiring repeated artificial ventilation (AV, were retrospectively studied. According to the AV mode, the patients were divided into 2 groups. Non-invasive AV was carried out in Group 1 (a study group. In Group 2 (a control group, tracheal intubation and mechanical ventilation were performed when respiratory indices deteriorated. In both groups, anesthesia was maintained without deviating from the clinically accepted protocol. The indications for extubation were routine. Following 24—72 hours after extubation, the health status of patients became worse, as manifested in decreased circulatory performance, requiring that they be switched to AV. Clinical and laboratory findings were used to define indications for AV switching. The conditions for noninvasive ventilation were the close cooperation of a patient with medical personnel, the absence of significant hyperthermia, injury, operation or facial abnormally, which excluded intimate mating. Results. Analysis of gas exchange changes suggests that there are no differences between the groups both just after surgery and within 24 postperfusion hours after extubation. When the condition deteriorated, no differences in oxygen exchange and delivery were observed in the study and control groups. In the control group, PaO2, oxygenation index, and oxygen delivery index were significantly less than those in the study group. Analysis of the duration of assisted ventilation revealed that the study group patients were on a respirator significantly less than the controls. The length of intensive care unit stay also increased greatly in Group 2

  19. Extubation success in premature infants with respiratory distress syndrome treated with bi-level nasal continuous positive airway pressure versus nasal intermittent positive pressure ventilation.

    Science.gov (United States)

    Thomas, Patricia E; LeFlore, Judy

    2013-01-01

    Infants born prematurely with respiratory distress syndrome are at high risk for complications from mechanical ventilation. Strategies are needed to minimize their days on the ventilator. The purpose of this study was to compare extubation success rates in infants treated with 2 different types of continuous positive airway pressure devices. A retrospective cohort study design was used. Data were retrieved from electronic medical records for patients in a large, metropolitan, level III neonatal intensive care unit. A sample of 194 premature infants with respiratory distress syndrome was selected, 124 of whom were treated with nasal intermittent positive pressure ventilation and 70 with bi-level variable flow nasal continuous positive airway pressure (bi-level nasal continuous positive airway pressure). Infants in both groups had high extubation success rates (79% of nasal intermittent positive pressure ventilation group and 77% of bi-level nasal continuous positive airway pressure group). Although infants in the bi-level nasal continuous positive airway pressure group were extubated sooner, there was no difference in duration of oxygen therapy between the 2 groups. Promoting early extubation and extubation success is a vital strategy to reduce complications of mechanical ventilation that adversely affect premature infants with respiratory distress syndrome.

  20. Comparison of the effect of lignocaine instilled through the endotracheal tube and intravenous lignocaine on the extubation response in patients undergoing craniotomy with skull pins: A randomized double blind clinical trial

    Directory of Open Access Journals (Sweden)

    Smitha Elizabeth George

    2013-01-01

    Full Text Available Background: A desirable combination of smooth extubation and an awake patient after neurosurgical procedures is difficult to achieve in patients with skull pins. Lignocaine instilled into endotracheal tube has been reported to suppress cough by a local mucosal anesthetizing effect. We aimed to evaluate if this effect will last till extubation, if given before pin removal. Materials and Methods: A total of 114 patients undergoing elective craniotomy were divided into three groups and were given 1 mg/kg of intravenous (IV, 2% lignocaine (Group 1, placebo (Group 2 and 1 mg/kg of 2% lignocaine sprayed down the endotracheal tube (Group 3 before skull pin removal. The effectiveness of each to blunt extubation response was compared. Plasma levels of lignocaine were measured 10 min after administration of the study drug and at extubation. Sedation scores were noted, immediately after extubation and 10 min later. Results: Two percent of lignocaine instilled through endotracheal route was not superior to the IV route or placebo in attenuating cough or hemodynamic response at extubation when given 20-30 min before extubation. The plasma levels of lignocaine (0.8 μg/ml were not high enough even at the end of 10 min to have a suppressive effect on cough if given IV or intratracheally (IT. Lignocaine did not delay awakening in these groups. Conclusion: IT lignocaine in the dose of 1 mg/kg does not prevent cough at extubation if given 20-30 min before extubation. If the action is by a local mucosal anesthetizing effect, it does not last for 20-30 min to cover the period from pin removal to extubation.

  1. Application of Machine Learning for Dragline Failure Prediction

    Directory of Open Access Journals (Sweden)

    Taghizadeh Amir

    2017-01-01

    Full Text Available Overburden stripping in open cast coal mines is extensively carried out by walking draglines. Draglines’ unavailability and unexpected failures result in delayed productions and increased maintenance and operating costs. Therefore, achieving high availability of draglines plays a crucial role for increasing economic feasibility of mining projects. Applications of methodologies which can forecast the failure type of dragline based on the available failure data not only help to reduce the maintenance and operating costs but also increase the availability and the production rate. In this study, Machine Learning approaches have been applied for data which has been gathered from an operating coal mine in Turkey. The study methodology consists of three algorithms as: i implementation of K-Nearest Neighbors, ii implementation of Multi-Layer Perceptron, and iii implementation of Radial Basis Function. The algorithms have been utilized for predicting the draglines’ failure types. In this sense, the input data, which are mean time-to-failure, and the output data, failure types, have been fed to the algorithms. The regression analysis of methodologies have been compared and showed the K- Nearest Neighbors has a higher rate of regression which is around 70 percent. Thus, the K-Nearest Neighbor algorithm can be applied in order to preventive components replacement which causes to minimized preventive and corrective cost parameters. The accurate prediction of failure type, indeed, causes to optimized number of inspections. The novelty of this study is application of machine learning approaches in draglines’ reliability subject for first time.

  2. Physiological effects of a single chest physiotherapy session in mechanically ventilated and extubated preterm neonates.

    Science.gov (United States)

    Mehta, Y; Shetye, J; Nanavati, R; Mehta, A

    2016-01-01

    To assess the changes on various physiological cardio-respiratory parameters with a single chest physiotherapy session in mechanically ventilated and extubated preterm neonates with respiratory distress syndrome. This is a prospective observational study in a neonatal intensive care unit setting. Sixty preterm neonates with respiratory distress syndrome, thirty mechanically ventilated and thirty extubated preterm neonates requiring chest physiotherapy were enrolled in the study. Parameters like heart rate (HR), respiratory rate (RR), Silverman Anderson score (SA score in extubated), oxygen saturation (SpO2) and auscultation findings were noted just before, immediately after chest physiotherapy but before suctioning, immediately after suctioning and after 5 minutes of the session. The mean age of neonates was 9.55±5.86 days and mean birth weight was 1550±511.5 g. As there was no significant difference in the change in parameters on intergroup comparison, further analysis was done considering two groups together (n = 60) except for SA score. As SA score was measured only in extubated neonates. HR did not change significantly during chest physiotherapy compared to the baseline but significantly decreased after 15 minutes (p = 0.01). RR and SA score significantly increased after suctioning (p = 0.014) but reduced after 15 minutes (p = physiotherapy (p = physiotherapy may help facilitate the overall well-being of a fragile preterm neonate. Lung auscultation finding suggests that after suctioning, there was a significant reduction in crepitation (p = 0.0000) but significant increase in crepitation after 15 minutes (p = physiotherapy. Chest physiotherapy is safe in preterm neonates. Suctioning causes significant cardio-respiratory parameter changes, but within normal physiological range. Thus, chest physiotherapy should be performed with continuous monitoring only when indicated and not as a routine procedure. More research is needed

  3. Does working memory capacity predict cross-modally induced failures of awareness?

    Science.gov (United States)

    Kreitz, Carina; Furley, Philip; Simons, Daniel J; Memmert, Daniel

    2016-01-01

    People often fail to notice unexpected stimuli when they are focusing attention on another task. Most studies of this phenomenon address visual failures induced by visual attention tasks (inattentional blindness). Yet, such failures also occur within audition (inattentional deafness), and people can even miss unexpected events in one sensory modality when focusing attention on tasks in another modality. Such cross-modal failures are revealing because they suggest the existence of a common, central resource limitation. And, such central limits might be predicted from individual differences in cognitive capacity. We replicated earlier evidence, establishing substantial rates of inattentional deafness during a visual task and inattentional blindness during an auditory task. However, neither individual working memory capacity nor the ability to perform the primary task predicted noticing in either modality. Thus, individual differences in cognitive capacity did not predict failures of awareness even though the failures presumably resulted from central resource limitations. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Risk factors associated with early reintubation in trauma patients: a prospective observational study.

    Science.gov (United States)

    Brown, Carlos V R; Daigle, Jacob B; Foulkrod, Kelli H; Brouillette, Brandee; Clark, Adam; Czysz, Clea; Martinez, Marnie; Cooper, Hassie

    2011-07-01

    After mechanical ventilation, extubation failure is associated with poor outcomes and prolonged hospital and intensive care unit (ICU) stays. We hypothesize that specific and unique risk factors exist for failed extubation in trauma patients. The purpose of this study was to identify the risk factors in trauma patients. We performed an 18-month (January 2008-June 2009) prospective, cohort study of all adult (8 years or older) trauma patients admitted to the ICU who required mechanical ventilation. Failure of extubation was defined as reintubation within 24 hours of extubation. Patients who failed extubation (failed group) were compared with those who were successfully extubated (successful group) to identify independent risk factors for failed extubation. A total of 276 patients were 38 years old, 76% male, 84% sustained blunt trauma, with an mean Injury Severity Score = 21, Glasgow Coma Scale (GCS) score = 7, and systolic blood pressure = 125 mm Hg. Indications for initial intubation included airway (4%), breathing (13%), circulation (2%), and neurologic disability (81%). A total of 17 patients (6%) failed extubation and failures occurred a mean of 15 hours after extubation. Independent risk factors to fail extubation included spine fracture, airway intubation, GCS at extubation, and delirium tremens. Patients who failed extubation spent more days in the ICU (11 vs. 6, p = 0.006) and hospital (19 vs. 11, p = 0.002). Mortality was 6% (n = 1) in the failed group and 0.4% (n = 1) in the successful extubation group. Independent risk factors for trauma patients to fail extubation include spine fracture, initial intubation for airway, GCS at extubation, and delirium tremens. Trauma patients with these four risk factors should be observed for 24 hours after extubation, because the mean time to failure was 15 hours. In addition, increased complications, extended need for mechanical ventilation, and prolonged ICU and hospital stays should be expected for trauma patients

  5. [Predictive factors for failure of non-invasive positive pressure ventilation in immunosuppressed patients with acute respiratory failure].

    Science.gov (United States)

    Jia, Xiangli; Yan, Ci; Xu, Sicheng; Gu, Xingli; Wan, Qiufeng; Hu, Xinying; Li, Jingwen; Liu, Guangming; Caikai, Shareli; Guo, Zhijin

    2018-02-01

    To evaluate the predictive factors for failure of non-invasive positive pressure ventilation (NIPPV) in immunosuppressed patients with acute respiratory failure (ARF). The clinical data of 118 immuno-deficient patients treated with NIPPV in the respiratory and intensive care unit (RICU) of the First Affiliated Hospital of Xinjiang Medical University from January 2012 to August 2017 were retrospectively analyzed. The patients were divided into a non-endotracheal intubation (ETI) group (n = 62) and ETI group (n = 56) according to whether ETI was performed during the hospitalization period or not. Each observed indicator was analyzed by univariate analysis, and factors leading to failure of NIPPV were further analyzed by Logistic regression. Receiver operating characteristic (ROC) curve was plotted to evaluate the predictive value of risk factors for failure of NIPPV in immunosuppressed patients with ARF. The non-intubation rate for NIPPV in immunosuppressed patients was 50.8% (60/118). Compared with the non-ETI group, the body temperature, pH value in the ETI group were significantly increased, the partial pressure of arterial carbon dioxide (PaCO 2 ) was significantly decreased, the ratio of oxygenation index (PaO 2 /FiO 2 ) failure of NIPPV. ROC curve analysis showed that the APACHE II score ≥ 20 and PaO 2 /FiO 2 failure of NIPPV, the area under ROC curve (AUC) of the APACHE II score ≥ 20 was 0.787, the sensitivity was 83.93%, the specificity was 69.35%, the positive predict value (PPV) was 71.21%, the negative predict value (NPV) was 82.69%, the positive likelihood ratio (PLR) was 2.74, the negative likelihood ratio (NLR) was 0.23, and Youden index was 0.53; the AUC of PaO 2 /FiO 2 failure of NIPPV in immunocompromised patients.

  6. Profound Endothelial Damage Predicts Impending Organ Failure and Death in Sepsis

    DEFF Research Database (Denmark)

    Johansen, Maria E; Johansson, Pär I.; Ostrowski, Sisse R

    2015-01-01

    levels at enrollment predicted risk of multiple organ failure during follow-up (HR [> 14 ng/mL vs. organ failure and death in septic......Endothelial damage contributes to organ failure and mortality in sepsis, but the extent of the contribution remains poorly quantified. Here, we examine the association between biomarkers of superficial and profound endothelial damage (syndecan-1 and soluble thrombomodulin [sTM], respectively......), organ failure, and death in sepsis. The data from a clinical trial, including critically ill patients predominantly suffering sepsis (Clinicaltrials.gov: NCT00271752) were studied. Syndecan-1 and sTM levels at the time of study enrollment were determined. The predictive ability of biomarker levels...

  7. Failure mitigation in software defined networking employing load type prediction

    KAUST Repository

    Bouacida, Nader

    2017-07-31

    The controller is a critical piece of the SDN architecture, where it is considered as the mastermind of SDN networks. Thus, its failure will cause a significant portion of the network to fail. Overload is one of the common causes of failure since the controller is frequently invoked by new flows. Even through SDN controllers are often replicated, the significant recovery time can be an overkill for the availability of the entire network. In order to overcome the problem of the overloaded controller failure in SDN, this paper proposes a novel controller offload solution for failure mitigation based on a prediction module that anticipates the presence of a harmful long-term load. In fact, the long-standing load would eventually overwhelm the controller leading to a possible failure. To predict whether the load in the controller is short-term or long-term load, we used three different classification algorithms: Support Vector Machine, k-Nearest Neighbors, and Naive Bayes. Our evaluation results demonstrate that Support Vector Machine algorithm is applicable for detecting the type of load with an accuracy of 97.93% in a real-time scenario. Besides, our scheme succeeded to offload the controller by switching between the reactive and proactive mode in response to the prediction module output.

  8. Association Rule-based Predictive Model for Machine Failure in Industrial Internet of Things

    Science.gov (United States)

    Kwon, Jung-Hyok; Lee, Sol-Bee; Park, Jaehoon; Kim, Eui-Jik

    2017-09-01

    This paper proposes an association rule-based predictive model for machine failure in industrial Internet of things (IIoT), which can accurately predict the machine failure in real manufacturing environment by investigating the relationship between the cause and type of machine failure. To develop the predictive model, we consider three major steps: 1) binarization, 2) rule creation, 3) visualization. The binarization step translates item values in a dataset into one or zero, then the rule creation step creates association rules as IF-THEN structures using the Lattice model and Apriori algorithm. Finally, the created rules are visualized in various ways for users’ understanding. An experimental implementation was conducted using R Studio version 3.3.2. The results show that the proposed predictive model realistically predicts machine failure based on association rules.

  9. Brittle Creep Failure, Critical Behavior, and Time-to-Failure Prediction of Concrete under Uniaxial Compression

    Directory of Open Access Journals (Sweden)

    Yingchong Wang

    2015-01-01

    Full Text Available Understanding the time-dependent brittle deformation behavior of concrete as a main building material is fundamental for the lifetime prediction and engineering design. Herein, we present the experimental measures of brittle creep failure, critical behavior, and the dependence of time-to-failure, on the secondary creep rate of concrete under sustained uniaxial compression. A complete evolution process of creep failure is achieved. Three typical creep stages are observed, including the primary (decelerating, secondary (steady state creep regime, and tertiary creep (accelerating creep stages. The time-to-failure shows sample-specificity although all samples exhibit a similar creep process. All specimens exhibit a critical power-law behavior with an exponent of −0.51 ± 0.06, approximately equal to the theoretical value of −1/2. All samples have a long-term secondary stage characterized by a constant strain rate that dominates the lifetime of a sample. The average creep rate expressed by the total creep strain over the lifetime (tf-t0 for each specimen shows a power-law dependence on the secondary creep rate with an exponent of −1. This could provide a clue to the prediction of the time-to-failure of concrete, based on the monitoring of the creep behavior at the steady stage.

  10. Predicting mortality in patients with heart failure : a pragmatic approach

    NARCIS (Netherlands)

    Bouvy, ML; Heerdink, ER; Leufkens, HGM; Hoes, AW

    Objective: To develop a comprehensive and easily applicable prognostic model predicting mortality risk in patients with moderate to severe heart failure. Design: Prospective follow up study. Setting: Seven general hospitals in the Netherlands. Patients: 152 outpatients with heart failure or patients

  11. Prediction of late failure after medical abortion from serial beta-hCG measurements and ultrasonography

    DEFF Research Database (Denmark)

    Rørbye, C; Nørgaard, M; Nilas, Lisbeth

    2004-01-01

    on day 15 were greater among late failures than successes. Used as a predictive test, the positive predictive values of these variables were low. CONCLUSION: Neither beta-hCG nor endometrial thickness can be used clinically as diagnostic tests in predicting late failure after medical abortion.......BACKGROUND: Surgical treatment of failed medical abortion may be performed several weeks after initiation of the abortion. There are no recognized methods for early identification of these late failures. We assessed the prognostic values of beta-hCG and ultrasonography in predicting late failure...... thickness by ultrasonography was performed on day 15 after induction of medical abortion. Failures diagnosed after day 15 and within 15 weeks were identified and classified as late failures. All interventions in this group were due to bleeding problems. The predictive values of different absolute...

  12. Prediction of failure strain and burst pressure in high yield-to-tensile strength ratio linepipe

    International Nuclear Information System (INIS)

    Law, M.; Bowie, G.

    2007-01-01

    Failure pressures and strains were predicted for a number of burst tests as part of a project to explore failure strain in high yield-to-tensile strength ratio linepipe. Twenty-three methods for predicting the burst pressure and six methods of predicting the failure strain are compared with test results. Several methods were identified which gave accurate and reliable estimates of burst pressure. No method of accurately predicting the failure strain was found, though the best was noted

  13. Prediction of failure strain and burst pressure in high yield-to-tensile strength ratio linepipe

    Energy Technology Data Exchange (ETDEWEB)

    Law, M. [Institute of Materials and Engineering Science, Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW (Australia)]. E-mail: mlx@ansto.gov.au; Bowie, G. [BlueScope Steel Ltd., Level 11, 120 Collins St, Melbourne, Victoria 3000 (Australia)

    2007-08-15

    Failure pressures and strains were predicted for a number of burst tests as part of a project to explore failure strain in high yield-to-tensile strength ratio linepipe. Twenty-three methods for predicting the burst pressure and six methods of predicting the failure strain are compared with test results. Several methods were identified which gave accurate and reliable estimates of burst pressure. No method of accurately predicting the failure strain was found, though the best was noted.

  14. Extubation process in bed-ridden elderly intensive care patients receiving inspiratory muscle training: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Cader SA

    2012-10-01

    Full Text Available Samária Ali Cader,1 Rodrigo Gomes de Souza Vale,1 Victor Emmanuel Zamora,2 Claudia Henrique Costa,2 Estélio Henrique Martin Dantas11Laboratory of Human Kinetics Bioscience, Federal University of Rio de Janeiro State, 2Pedro Ernesto University Hospital, School of Medicine, State University of Rio de Janeiro, Rio de Janeiro, BrazilBackground: The purpose of this study was to evaluate the extubation process in bed-ridden elderly intensive care patients receiving inspiratory muscle training (IMT and identify predictors of successful weaning.Methods: Twenty-eight elderly intubated patients in an intensive care unit were randomly assigned to an experimental group (n = 14 that received conventional physiotherapy plus IMT with a Threshold IMT® device or to a control group (n = 14 that received only conventional physiotherapy. The experimental protocol for muscle training consisted of an initial load of 30% maximum inspiratory pressure, which was increased by 10% daily. The training was administered for 5 minutes, twice daily, 7 days a week, with supplemental oxygen from the beginning of weaning until extubation. Successful extubation was defined by the ventilation time measurement with noninvasive positive pressure. A vacuum manometer was used for measurement of maximum inspiratory pressure, and the patients' Tobin index values were measured using a ventilometer.Results: The maximum inspiratory pressure increased significantly (by 7 cm H2O, 95% confidence interval [CI] 4–10, and the Tobin index decreased significantly (by 16 breaths/min/L, 95% CI −26 to 6 in the experimental group compared with the control group. The Chi-squared distribution did not indicate a significant difference in weaning success between the groups (Χ2 = 1.47; P = 0.20. However, a comparison of noninvasive positive pressure time dependence indicated a significantly lower value for the experimental group (P = 0.0001; 95% CI 13.08–18.06. The receiver

  15. Feasibility and safety of on table extubation after corrective surgical repair of tetralogy of Fallot in a developing country: A case series

    Directory of Open Access Journals (Sweden)

    Mohammad Irfan Akhtar

    2015-01-01

    Full Text Available Fast-track extubation is an established safe practice in pediatric congenital heart disease (CHD surgical patients. On table extubation (OTE in acyanotic CHD surgical patients is well established with validated safety profile. This practice is not yet reported in tetralogy of Fallot (TOF cardiac surgical repair patients in developing countries. Evidence suggests that TOF total correction patients should be extubated early, as positive pressure ventilation has a negative impact on right ventricular function and the overall increase in post-TOF repair complications such as low cardiac output state and arrhythmias. The objective of the case series was to determine the safety and feasibility of OTE in elective TOF total correction cardiac surgical patients with an integrated team approach. To the best of our knowledge, this is the first reported case series. A total of 8 elective male and female TOF patients were included. Standard anesthetic, surgical and perfusion techniques were used in these procedures. All patients were extubated in the operating room safely without any complications with the exception of one patient who continued to bleed for 3 h of postextubation at 2-3 ml/kg/h which was managed with transfusion of fresh frozen plasma at 15 mL/kg, packed red blood cells 10 mL/kg and bolus of transamine at 20 mg/kg. Apart from better surgical and bypass techniques, the most important factor leading to successful OTE was an excellent analgesia. On the basis of the case series, it is suggested to extubate selected TOF cardiac surgery repair patients on table safely with integrated multidisciplinary approach.

  16. Accurate Prediction of Motor Failures by Application of Multi CBM Tools: A Case Study

    Science.gov (United States)

    Dutta, Rana; Singh, Veerendra Pratap; Dwivedi, Jai Prakash

    2018-02-01

    Motor failures are very difficult to predict accurately with a single condition-monitoring tool as both electrical and the mechanical systems are closely related. Electrical problem, like phase unbalance, stator winding insulation failures can, at times, lead to vibration problem and at the same time mechanical failures like bearing failure, leads to rotor eccentricity. In this case study of a 550 kW blower motor it has been shown that a rotor bar crack was detected by current signature analysis and vibration monitoring confirmed the same. In later months in a similar motor vibration monitoring predicted bearing failure and current signature analysis confirmed the same. In both the cases, after dismantling the motor, the predictions were found to be accurate. In this paper we will be discussing the accurate predictions of motor failures through use of multi condition monitoring tools with two case studies.

  17. Narrowing the scope of failure prediction using targeted fault load injection

    Science.gov (United States)

    Jordan, Paul L.; Peterson, Gilbert L.; Lin, Alan C.; Mendenhall, Michael J.; Sellers, Andrew J.

    2018-05-01

    As society becomes more dependent upon computer systems to perform increasingly critical tasks, ensuring that those systems do not fail becomes increasingly important. Many organizations depend heavily on desktop computers for day-to-day operations. Unfortunately, the software that runs on these computers is written by humans and, as such, is still subject to human error and consequent failure. A natural solution is to use statistical machine learning to predict failure. However, since failure is still a relatively rare event, obtaining labelled training data to train these models is not a trivial task. This work presents new simulated fault-inducing loads that extend the focus of traditional fault injection techniques to predict failure in the Microsoft enterprise authentication service and Apache web server. These new fault loads were successful in creating failure conditions that were identifiable using statistical learning methods, with fewer irrelevant faults being created.

  18. Prediction of hospital failure: a post-PPS analysis.

    Science.gov (United States)

    Gardiner, L R; Oswald, S L; Jahera, J S

    1996-01-01

    This study investigates the ability of discriminant analysis to provide accurate predictions of hospital failure. Using data from the period following the introduction of the Prospective Payment System, we developed discriminant functions for each of two hospital ownership categories: not-for-profit and proprietary. The resulting discriminant models contain six and seven variables, respectively. For each ownership category, the variables represent four major aspects of financial health (liquidity, leverage, profitability, and efficiency) plus county marketshare and length of stay. The proportion of closed hospitals misclassified as open one year before closure does not exceed 0.05 for either ownership type. Our results show that discriminant functions based on a small set of financial and nonfinancial variables provide the capability to predict hospital failure reliably for both not-for-profit and proprietary hospitals.

  19. Neural breathing pattern in newborn infants pre- and postextubation.

    Science.gov (United States)

    Iyer, Narayan P; Dickson, John; Ruiz, Michelle E; Chatburn, Robert; Beck, Jennifer; Sinderby, Chister; Rodriguez, Ricardo J

    2017-12-01

    To describe the neural breathing pattern before and after extubation in newborn infants. Prospective, observational study. In infants deemed ready for extubation, the diaphragm electrical activity (EAdi) was continuously recorded from 30 minute before to two hours after extubation. Total of 25 neonates underwent 29 extubations; 10 extubations resulted in re-intubation within 72 hours. Postextubation, there was an increase in peak EAdi (EAdi-max) and EAdi-delta (peak minus minimum EAdi) in both groups. The pre- to postextubation change in EAdi-max (8.9-11.1 μv) and EAdi-delta (6-8 μv) was less in the failure group in comparison with the change in EAdi-max (10.2-13.4 μv) and EAdi-delta (6.3-10.6 μv) in the success group, (p = 0.02 and 0.01, respectively). In our neonatal cohort, extubation failure was associated with a smaller increase in peak and delta EAdi after extubation. If confirmed, these findings indicate an important cause of extubation failure in preterm infants. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  20. On-table Extubation after Open Heart Surgery in Children: An Experience from a Tertiary Care Hospital in a Developing Country.

    Science.gov (United States)

    Hoda, Mehar; Haque, Anwarul; Aijaz, Fareena; Akhtar, Mohammad I; Rehmat, Amina; Amanullah, Muneer; Hasan, Babar S

    2016-01-01

    Recent advances in various disciplines of medicine have significantly changed the courses following cardiac surgery in children. On-table extubation (OTE) after open heart surgery in children is evolving. To assess the rate of postoperative complications in children extubated on table after open heart surgery. This is a retrospective, descriptive study. Operating room (OR) then admitted to the pediatric intensive care unit (PICU). All pediatric patients (between 0 and 18 years) undergoing open heart surgery between January 2011 and June 2013. On-table extubation. Rates of immediate postoperative complications, i.e., re-intubation, significant bleeding, low cardiac output syndrome, and arrhythmia in PICU, were assessed. Data are presented as frequencies and mean ± standard deviation. A total of 82 patients were included. Mean age at time of operation was 7.25 ± 6.6 years. Fifty-three percent (n = 44) were open heart surgery was feasible and safe in selected group of patients. There was no major complication observed in the PICU. © 2015 Wiley Periodicals, Inc.

  1. Individual Prediction of Heart Failure Among Childhood Cancer Survivors

    Science.gov (United States)

    Chow, Eric J.; Chen, Yan; Kremer, Leontien C.; Breslow, Norman E.; Hudson, Melissa M.; Armstrong, Gregory T.; Border, William L.; Feijen, Elizabeth A.M.; Green, Daniel M.; Meacham, Lillian R.; Meeske, Kathleen A.; Mulrooney, Daniel A.; Ness, Kirsten K.; Oeffinger, Kevin C.; Sklar, Charles A.; Stovall, Marilyn; van der Pal, Helena J.; Weathers, Rita E.; Robison, Leslie L.; Yasui, Yutaka

    2015-01-01

    Purpose To create clinically useful models that incorporate readily available demographic and cancer treatment characteristics to predict individual risk of heart failure among 5-year survivors of childhood cancer. Patients and Methods Survivors in the Childhood Cancer Survivor Study (CCSS) free of significant cardiovascular disease 5 years after cancer diagnosis (n = 13,060) were observed through age 40 years for the development of heart failure (ie, requiring medications or heart transplantation or leading to death). Siblings (n = 4,023) established the baseline population risk. An additional 3,421 survivors from Emma Children's Hospital (Amsterdam, the Netherlands), the National Wilms Tumor Study, and the St Jude Lifetime Cohort Study were used to validate the CCSS prediction models. Results Heart failure occurred in 285 CCSS participants. Risk scores based on selected exposures (sex, age at cancer diagnosis, and anthracycline and chest radiotherapy doses) achieved an area under the curve of 0.74 and concordance statistic of 0.76 at or through age 40 years. Validation cohort estimates ranged from 0.68 to 0.82. Risk scores were collapsed to form statistically distinct low-, moderate-, and high-risk groups, corresponding to cumulative incidences of heart failure at age 40 years of 0.5% (95% CI, 0.2% to 0.8%), 2.4% (95% CI, 1.8% to 3.0%), and 11.7% (95% CI, 8.8% to 14.5%), respectively. In comparison, siblings had a cumulative incidence of 0.3% (95% CI, 0.1% to 0.5%). Conclusion Using information available to clinicians soon after completion of childhood cancer therapy, individual risk for subsequent heart failure can be predicted with reasonable accuracy and discrimination. These validated models provide a framework on which to base future screening strategies and interventions. PMID:25287823

  2. An Integrated Model to Predict Corporate Failure of Listed Companies in Sri Lanka

    Directory of Open Access Journals (Sweden)

    Nisansala Wijekoon

    2015-07-01

    Full Text Available The primary objective of this study is to develop an integrated model to predict corporate failure of listed companies in Sri Lanka. The logistic regression analysis was employed to a data set of 70 matched-pairs of failed and non-failed companies listed in the Colombo Stock Exchange (CSE in Sri Lanka over the period 2002 to 2010. A total of fifteen financial ratios and eight corporate governance variables were used as predictor variables of corporate failure. Analysis of the statistical testing results indicated that model consists with both corporate governance variables and financial ratios improved the prediction accuracy to reach 88.57 per cent one year prior to failure. Furthermore, predictive accuracy of this model in all three years prior to failure is above 80 per cent. Hence model is robust in obtaining accurate results for up to three years prior to failure. It was further found that two financial ratios, working capital to total assets and cash flow from operating activities to total assets, and two corporate governance variables, outside director ratio and company audit committee are having more explanatory power to predict corporate failure. Therefore, model developed in this study can assist investors, managers, shareholders, financial institutions, auditors and regulatory agents in Sri Lanka to forecast corporate failure of listed companies.

  3. Reliability prediction system based on the failure rate model for electronic components

    International Nuclear Information System (INIS)

    Lee, Seung Woo; Lee, Hwa Ki

    2008-01-01

    Although many methodologies for predicting the reliability of electronic components have been developed, their reliability might be subjective according to a particular set of circumstances, and therefore it is not easy to quantify their reliability. Among the reliability prediction methods are the statistical analysis based method, the similarity analysis method based on an external failure rate database, and the method based on the physics-of-failure model. In this study, we developed a system by which the reliability of electronic components can be predicted by creating a system for the statistical analysis method of predicting reliability most easily. The failure rate models that were applied are MILHDBK- 217F N2, PRISM, and Telcordia (Bellcore), and these were compared with the general purpose system in order to validate the effectiveness of the developed system. Being able to predict the reliability of electronic components from the stage of design, the system that we have developed is expected to contribute to enhancing the reliability of electronic components

  4. Extubation process in bed-ridden elderly intensive care patients receiving inspiratory muscle training: a randomized clinical trial.

    Science.gov (United States)

    Cader, Samária Ali; de Souza Vale, Rodrigo Gomes; Zamora, Victor Emmanuel; Costa, Claudia Henrique; Dantas, Estélio Henrique Martin

    2012-01-01

    The purpose of this study was to evaluate the extubation process in bed-ridden elderly intensive care patients receiving inspiratory muscle training (IMT) and identify predictors of successful weaning. Twenty-eight elderly intubated patients in an intensive care unit were randomly assigned to an experimental group (n = 14) that received conventional physiotherapy plus IMT with a Threshold IMT(®) device or to a control group (n = 14) that received only conventional physiotherapy. The experimental protocol for muscle training consisted of an initial load of 30% maximum inspiratory pressure, which was increased by 10% daily. The training was administered for 5 minutes, twice daily, 7 days a week, with supplemental oxygen from the beginning of weaning until extubation. Successful extubation was defined by the ventilation time measurement with noninvasive positive pressure. A vacuum manometer was used for measurement of maximum inspiratory pressure, and the patients' Tobin index values were measured using a ventilometer. The maximum inspiratory pressure increased significantly (by 7 cm H(2)O, 95% confidence interval [CI] 4-10), and the Tobin index decreased significantly (by 16 breaths/ min/L, 95% CI -26 to 6) in the experimental group compared with the control group. The Chi-squared distribution did not indicate a significant difference in weaning success between the groups (χ(2) = 1.47; P = 0.20). However, a comparison of noninvasive positive pressure time dependence indicated a significantly lower value for the experimental group (P = 0.0001; 95% CI 13.08-18.06). The receiver-operating characteristic curve showed an area beneath the curve of 0.877 ± 0.06 for the Tobin index and 0.845 ± 0.07 for maximum inspiratory pressure. The IMT intervention significantly increased maximum inspiratory pressure and significantly reduced the Tobin index; both measures are considered to be good extubation indices. IMT was associated with a reduction in noninvasive positive

  5. Time to tracheal extubation after coronary artery surgery with isoflurane, sevoflurane, or target-controlled propofol anesthesia: a prospective, randomized, controlled trial.

    Science.gov (United States)

    Parker, Francis C; Story, David A; Poustie, Stephanie; Liu, Guoming; McNicol, Larry

    2004-10-01

    To determine if anesthesia with sevoflurane or target-controlled propofol reduced the time to tracheal extubation after coronary artery bypass graft surgery compared with isoflurane anesthesia. A 3-arm (isoflurane, sevoflurane, or propofol), randomized, controlled trial with patients and intensive care staff blinded to the drug allocation. A single, tertiary referral hospital affiliated with the University of Melbourne. Three hundred sixty elective coronary artery surgery patients. Patients received either isoflurane (control group, 0.5%-2% end-tidal concentration), sevoflurane (1%-4% end-tidal concentration), or target-controlled infusion of propofol (1-8 microg/mL plasma target concentration) as part of a balanced, standardized anesthetic technique including 15 microg/kg of fentanyl. The primary outcome was time to tracheal extubation. The median time to tracheal extubation for the propofol group was 10.25 hours (interquartile range [IQR] 8.08-12.75), the sevoflurane group 9.17 hours (IQR 6.25-11.25), and the isoflurane group 7.67 hours (IQR 6.25-9.42). Intraoperatively, the propofol group required less vasopressor (p = 0.002) and more vasodilator therapy (nitroglycerin p = 0.01, nitroprusside p = 0.002). There was no difference among the groups in time to intensive care unit discharge. The median time to tracheal extubation was significantly longer for the target-controlled propofol group. A significantly greater number in this group required the use of a vasodilator to control intraoperative hypertension.

  6. Predictive value of EndTidalCO2, lung mechanics and other standard parameters for weaning neurological patients from mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Hala A. Mohammad

    2016-01-01

    Conclusion: We concluded that measurements of RSBI, MIP (maximum inspiratory pressure, EndTidalCO2 and dynamic compliance were more accurate predictors of extubation failure in patients with neurological insults than other standard weaning parameters.

  7. Prediction of Ductile Failure in the Stretch-Forming of AA2024 Sheets

    International Nuclear Information System (INIS)

    Vallellano, C.; Guzman, C.; Garcia-Lomas, F. J.

    2007-01-01

    A number of ductile failure criteria are nowadays being used to predict the formability of aluminium alloy sheets. Generally speaking, integral criteria (e.g. those proposed by Cockcroft and Latham, Brozzo et al., Oyane et al Chaouadi et al., etc.) have been probed to work well when the principal strains are of opposite sign, i.e. in the left side of the Forming Limit Diagram (FLD). However, when tensile biaxial strains are present, as occurs in stretch-forming practice, their predictions are usually very poor and even non-conservatives. As an alternative, local criteria, such as the classical Tresca's and Bressan and Williams' criteria, have demonstrated a good capability to predict the failure in some automotive aluminum alloys under stretching. The present work analyses experimentally and numerically the failure in AA2024-T3 sheets subjected to biaxial stretching. A series of out-of-plane stretching tests have been simulated using ABAQUS. The experimental and the numerical FLD for different failure criteria are compared. The influence on the failure of the hydrostatic pressure and the normal stress to the fracture plane is also discussed

  8. A physical probabilistic model to predict failure rates in buried PVC pipelines

    International Nuclear Information System (INIS)

    Davis, P.; Burn, S.; Moglia, M.; Gould, S.

    2007-01-01

    For older water pipeline materials such as cast iron and asbestos cement, future pipe failure rates can be extrapolated from large volumes of existing historical failure data held by water utilities. However, for newer pipeline materials such as polyvinyl chloride (PVC), only limited failure data exists and confident forecasts of future pipe failures cannot be made from historical data alone. To solve this problem, this paper presents a physical probabilistic model, which has been developed to estimate failure rates in buried PVC pipelines as they age. The model assumes that under in-service operating conditions, crack initiation can occur from inherent defects located in the pipe wall. Linear elastic fracture mechanics theory is used to predict the time to brittle fracture for pipes with internal defects subjected to combined internal pressure and soil deflection loading together with through-wall residual stress. To include uncertainty in the failure process, inherent defect size is treated as a stochastic variable, and modelled with an appropriate probability distribution. Microscopic examination of fracture surfaces from field failures in Australian PVC pipes suggests that the 2-parameter Weibull distribution can be applied. Monte Carlo simulation is then used to estimate lifetime probability distributions for pipes with internal defects, subjected to typical operating conditions. As with inherent defect size, the 2-parameter Weibull distribution is shown to be appropriate to model uncertainty in predicted pipe lifetime. The Weibull hazard function for pipe lifetime is then used to estimate the expected failure rate (per pipe length/per year) as a function of pipe age. To validate the model, predicted failure rates are compared to aggregated failure data from 17 UK water utilities obtained from the United Kingdom Water Industry Research (UKWIR) National Mains Failure Database. In the absence of actual operating pressure data in the UKWIR database, typical

  9. Prediction of failures in linear systems with the use of tolerance ranges

    International Nuclear Information System (INIS)

    Gadzhiev, Ch.M.

    1993-01-01

    The problem of predicting the technical state of an object can be stated in a general case as that of predicting potential failures on the basis of a quantitative evaluation of the predicted parameters in relation to the set of tolerances on these parameters. The main stages in the prediction are collecting and preparing source data on the prehistory of the predicted phenomenon, forming a mathematical model of this phenomenon, working out the algorithm for the prediction, and adopting a solution from the prediction results. The final two stages of prediction are considered in this article. The prediction algorithm is proposed based on construction of the tolerance range for the signal of error between output coordinates of the system and its mathematical model. A solution regarding possible occurrence of failure in the system is formulated as a result of comparison of the tolerance range and the found confidence interval. 5 refs

  10. Predicting the Failure of Dental Implants Using Supervised Learning Techniques

    Directory of Open Access Journals (Sweden)

    Chia-Hui Liu

    2018-05-01

    Full Text Available Prosthodontic treatment has been a crucial part of dental treatment for patients with full mouth rehabilitation. Dental implant surgeries that replace conventional dentures using titanium fixtures have become the top choice. However, because of the wide-ranging scope of implant surgeries, patients’ body conditions, surgeons’ experience, and the choice of implant system should be considered during treatment. The higher price charged by dental implant treatments compared to conventional dentures has led to a rush among medical staff; therefore, the future impact of surgeries has not been analyzed in detail, resulting in medial disputes. Previous literature on the success factors of dental implants is mainly focused on single factors such as patients’ systemic diseases, operation methods, or prosthesis types for statistical correlation significance analysis. This study developed a prediction model for providing an early warning mechanism to reduce the chances of dental implant failure. We collected the clinical data of patients who received artificial dental implants at the case hospital for a total of 8 categories and 20 variables. Supervised learning techniques such as decision tree (DT, support vector machines, logistic regressions, and classifier ensembles (i.e., Bagging and AdaBoost were used to analyze the prediction of the failure of dental implants. The results show that DT with both Bagging and Adaboost techniques possesses the highest prediction performance for the failure of dental implant (area under the receiver operating characteristic curve, AUC: 0.741; the analysis also revealed that the implant systems affect dental implant failure. The model can help clinical surgeons to reduce medical failures by choosing the optimal implant system and prosthodontics treatments for their patients.

  11. Predictors of incident heart failure in patients after an acute coronary syndrome: The LIPID heart failure risk-prediction model.

    Science.gov (United States)

    Driscoll, Andrea; Barnes, Elizabeth H; Blankenberg, Stefan; Colquhoun, David M; Hunt, David; Nestel, Paul J; Stewart, Ralph A; West, Malcolm J; White, Harvey D; Simes, John; Tonkin, Andrew

    2017-12-01

    Coronary heart disease is a major cause of heart failure. Availability of risk-prediction models that include both clinical parameters and biomarkers is limited. We aimed to develop such a model for prediction of incident heart failure. A multivariable risk-factor model was developed for prediction of first occurrence of heart failure death or hospitalization. A simplified risk score was derived that enabled subjects to be grouped into categories of 5-year risk varying from 20%. Among 7101 patients from the LIPID study (84% male), with median age 61years (interquartile range 55-67years), 558 (8%) died or were hospitalized because of heart failure. Older age, history of claudication or diabetes mellitus, body mass index>30kg/m 2 , LDL-cholesterol >2.5mmol/L, heart rate>70 beats/min, white blood cell count, and the nature of the qualifying acute coronary syndrome (myocardial infarction or unstable angina) were associated with an increase in heart failure events. Coronary revascularization was associated with a lower event rate. Incident heart failure increased with higher concentrations of B-type natriuretic peptide >50ng/L, cystatin C>0.93nmol/L, D-dimer >273nmol/L, high-sensitivity C-reactive protein >4.8nmol/L, and sensitive troponin I>0.018μg/L. Addition of biomarkers to the clinical risk model improved the model's C statistic from 0.73 to 0.77. The net reclassification improvement incorporating biomarkers into the clinical model using categories of 5-year risk was 23%. Adding a multibiomarker panel to conventional parameters markedly improved discrimination and risk classification for future heart failure events. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  12. Factors Predicting Treatment Failure in Patients Treated with Iodine-131 for Graves’ Disease

    International Nuclear Information System (INIS)

    Manohar, Kuruva; Mittal, Bhagwant Rai; Bhoil, Amit; Bhattacharya, Anish; Dutta, Pinaki; Bhansali, Anil

    2013-01-01

    Treatment of Graves' disease with iodine-131 ( 131 I) is well-known; however, all patients do not respond to a single dose of 131 I and may require higher and repeated doses. This study was carried out to identify the factors, which can predict treatment failure to a single dose of 131 I treatment in these patients. Data of 150 patients with Graves' disease treated with 259-370 MBq of 131 I followed-up for at least 1-year were retrospectively analyzed. Logistic regression analysis was used to predict factors which can predict treatment failure, such as age, sex, duration of disease, grade of goiter, duration of treatment with anti-thyroid drugs, mean dosage of anti-thyroid drugs used, 99m Tc-pertechnetate ( 99m TcO 4 - ) uptake at 20 min, dose of 131 I administered, total triiodothyronine and thyroxine levels. Of the 150 patients, 25 patients required retreatment within 1 year of initial treatment with 131 I. Logistic regression analysis revealed that male sex and 99m TcO 4 - uptake were associated with treatment failure. On receiver operating characteristic (ROC) curve analysis, area under the curve (AUC) was significant for 99m TcO 4 - uptake predicting treatment failure (AUC = 0.623; P = 0.039). Optimum cutoff for 99m TcO 4 - uptake was 17.75 with a sensitivity of 68% and specificity of 66% to predict treatment failure. Patients with >17.75% 99m TcO 4 - uptake had odds ratio of 3.14 (P = 0.014) for treatment failure and male patients had odds ratio of 1.783 for treatment failure. Our results suggest that male patients and patients with high pre-treatment 99m TcO 4 - uptake are more likely to require repeated doses of 131 I to achieve complete remission

  13. Comparison of cough reflex testing with videoendoscopy in recently extubated intensive care unit patients.

    Science.gov (United States)

    Kallesen, Molly; Psirides, Alex; Huckabee, Maggie-Lee

    2016-06-01

    Orotracheal intubation is known to impair cough reflex, but the validity of cough reflex testing (CRT) as a screening tool for silent aspiration in this population is unknown. One hundred and six participants in a tertiary-level intensive care unit (ICU) underwent CRT and videoendoscopic evaluation of swallowing (VES) within 24 hours of extubation. Cough reflex threshold was established for each participant using nebulized citric acid. Thirty-nine (37%) participants had an absent cough to CRT. Thirteen (12%) participants aspirated on VES, 9 (69%) without a cough response. Sensitivity of CRT to identify silent aspiration was excellent, but specificity was poor. There was a significant correlation between intubation duration and presence of aspiration on VES (P= .0107). There was no significant correlation between silent aspiration on VES and length of intubation, age, sex, diagnosis at intensive care unit admission, indication for intubation, Acute Physiology and Chronic Health Evaluation III score, morphine equivalent dose, or time of testing postextubation. Intensive care unit patients are at increased risk of aspiration in the 24 hours following extubation, and an impaired cough reflex is common. However, CRT overidentifies risk of silent aspiration in this population. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Momento da extubação e evolução pós-operatória de toracotomia Time of extubation and postoperative outcome after thoracotomy

    Directory of Open Access Journals (Sweden)

    Carolina Pereira da Silva Almada

    2007-06-01

    % no grupo de extubação imediata e 58,3% no grupo de extubação não imediata; pacientes ASA 3 a 5 8% no grupo de extubação imediata e 8,3% no grupo de extubação não imediata. O tempo cirúrgico (média ± desvio-padrão foi de 372,34 ± 107,84 minutos no grupo extubado imediatamente e 432,61 ± 117,30 minutos no grupo não-extubado. O risco relativo para a extubação imediata favorecer má evolução foi 0,81; enquanto para a extubação não imediata favorecer má evolução foi 1,5. CONCLUSÃO: É possível a extubação traqueal imediata com segurança de pacientes submetidos a cirurgias de ressecção pulmonar. Tal conduta facilita a recuperação pós-operatória fora da Unidade de Terapia Intensiva, resultando em benefícios aos pacientes e aos hospitais.OBJECTIVE: Early tracheal extubation following surgical procedures favors clinical evolution of patients and reduces incidence and time of stay in the Intensive Care Unit (ICU, minimizing hospital costs. Immediate postoperative period of pulmonary resections often takes place in the ICU and patients are kept intubated. This study evaluated hospital records of patients submitted to thoracotomy and a correlation between extubation time, postoperative evolution and ICU stay was established. METHODS: Retrospective cohort study of records of 121 patients submitted to pulmonary parenchyma resection (not biopsies was carried out. Stay in the ICU and time of tracheal extubation were related. Postoperative evolution was classified as good or bad according to occurrence of some of the following conditions: infections, respiratory disorders (reintubation, bronchospasm, acute pulmonary edema, need of tracheotomy, atelectasis, fistulae, re-operation due to bleeding and death. Among the two groups preoperative conditions, anesthetic physical status (American Society of Anesthesyologists - ASA criteria, presence of associated diseases, respiratory functional evaluation and duration of surgery were analyzed. Relative

  15. Predictive Simulation of Material Failure Using Peridynamics -- Advanced Constitutive Modeling, Verification and Validation

    Science.gov (United States)

    2016-03-31

    AFRL-AFOSR-VA-TR-2016-0309 Predictive simulation of material failure using peridynamics- advanced constitutive modeling, verification , and validation... Self -explanatory. 8. PERFORMING ORGANIZATION REPORT NUMBER. Enter all unique alphanumeric report numbers assigned by the performing organization, e.g...for public release. Predictive simulation of material failure using peridynamics-advanced constitutive modeling, verification , and validation John T

  16. Predictive Factors of Respiratory Failure in Children with Guillain-Barre Syndrome

    Directory of Open Access Journals (Sweden)

    Nemat Bilan

    2015-03-01

    Full Text Available Introduction:Guillain-Barre Syndrome(GBS is the most common cause of acute flaccid paralysis. Respiratory failure is the most serious short-term complication of GBS and invasive mechanical ventilation is required in 30% of patients.moreover,60% of those who are intubated develop major complications including pnemonia,sepsis,GI bleeding and pulmonary embolism. Thus respiratory failure prediction is crucial. the aim of this study was to determine clinical predictors of respiratory failure to avoid respiratory distress and aspiration.Methods and materials: in a cross sectional and analytical study 140 patients with clinically diagnosis of Guillain-Barre Syndrome were enrolled in study,from october 2008 to october 2014. .demographic data,nerologic examination,cranial nerve and autonomic nervous system involvement, and respiratory failure were recorded prospectively.Results:15 out of 140 patients(10,7% developed respiratory failure and underwent mechanical ventilation.the male/female ratio in patients with respiratory failure and patients without respiratory involvement were (53%/(47% and (54%/(46% respectively(p-value:0.4.the mean age in these two groups were 2,7±1,9 and 5,5±3,2(p-value:0,003.cranial nerve involvement (7,9,10 was recorded in patients with respiratory failure and without respiratory failure54% and25% respectively (p-value:0,03.absent upper limb deep tendon reflexes in these two groups were 70% and 44% respectively.(p-value:0,03 and autonomic nervous system involvement 24% vs. 14%(p-value:0,3.conclusion : our study suggests that younger age , cranial nerve involvement and absent upper limb deep tendon reflexes are predictive factors of respiratory failure in patients with Guillain-Barre Syndrome(GBS.

  17. Heart Failure: Diagnosis, Severity Estimation and Prediction of Adverse Events Through Machine Learning Techniques

    Directory of Open Access Journals (Sweden)

    Evanthia E. Tripoliti

    Full Text Available Heart failure is a serious condition with high prevalence (about 2% in the adult population in developed countries, and more than 8% in patients older than 75 years. About 3–5% of hospital admissions are linked with heart failure incidents. Heart failure is the first cause of admission by healthcare professionals in their clinical practice. The costs are very high, reaching up to 2% of the total health costs in the developed countries. Building an effective disease management strategy requires analysis of large amount of data, early detection of the disease, assessment of the severity and early prediction of adverse events. This will inhibit the progression of the disease, will improve the quality of life of the patients and will reduce the associated medical costs. Toward this direction machine learning techniques have been employed. The aim of this paper is to present the state-of-the-art of the machine learning methodologies applied for the assessment of heart failure. More specifically, models predicting the presence, estimating the subtype, assessing the severity of heart failure and predicting the presence of adverse events, such as destabilizations, re-hospitalizations, and mortality are presented. According to the authors' knowledge, it is the first time that such a comprehensive review, focusing on all aspects of the management of heart failure, is presented. Keywords: Heart failure, Diagnosis, Prediction, Severity estimation, Classification, Data mining

  18. Automatic stimulation of experiments and learning based on prediction failure recognition

    NARCIS (Netherlands)

    Juarez Cordova, A.G.; Kahl, B.; Henne, T.; Prassler, E.

    2009-01-01

    In this paper we focus on the task of automatically and autonomously initiating experimentation and learning based on the recognition of prediction failure. We present a mechanism that utilizes conceptual knowledge to predict the outcome of robot actions, observes their execution and indicates when

  19. Individual Prediction of Heart Failure Among Childhood Cancer Survivors

    NARCIS (Netherlands)

    Chow, Eric J.; Chen, Yan; Kremer, Leontien C.; Breslow, Norman E.; Hudson, Melissa M.; Armstrong, Gregory T.; Border, William L.; Feijen, Elizabeth A. M.; Green, Daniel M.; Meacham, Lillian R.; Meeske, Kathleen A.; Mulrooney, Daniel A.; Ness, Kirsten K.; Oeffinger, Kevin C.; Sklar, Charles A.; Stovall, Marilyn; van der Pal, Helena J.; Weathers, Rita E.; Robison, Leslie L.; Yasui, Yutaka

    2015-01-01

    Purpose To create clinically useful models that incorporate readily available demographic and cancer treatment characteristics to predict individual risk of heart failure among 5-year survivors of childhood cancer. Patients and Methods Survivors in the Childhood Cancer Survivor Study (CCSS) free of

  20. A model-based prognostic approach to predict interconnect failure using impedance analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Dae Il; Yoon, Jeong Ah [Dept. of System Design and Control Engineering. Ulsan National Institute of Science and Technology, Ulsan (Korea, Republic of)

    2016-10-15

    The reliability of electronic assemblies is largely affected by the health of interconnects, such as solder joints, which provide mechanical, electrical and thermal connections between circuit components. During field lifecycle conditions, interconnects are often subjected to a DC open circuit, one of the most common interconnect failure modes, due to cracking. An interconnect damaged by cracking is sometimes extremely hard to detect when it is a part of a daisy-chain structure, neighboring with other healthy interconnects that have not yet cracked. This cracked interconnect may seem to provide a good electrical contact due to the compressive load applied by the neighboring healthy interconnects, but it can cause the occasional loss of electrical continuity under operational and environmental loading conditions in field applications. Thus, cracked interconnects can lead to the intermittent failure of electronic assemblies and eventually to permanent failure of the product or the system. This paper introduces a model-based prognostic approach to quantitatively detect and predict interconnect failure using impedance analysis and particle filtering. Impedance analysis was previously reported as a sensitive means of detecting incipient changes at the surface of interconnects, such as cracking, based on the continuous monitoring of RF impedance. To predict the time to failure, particle filtering was used as a prognostic approach using the Paris model to address the fatigue crack growth. To validate this approach, mechanical fatigue tests were conducted with continuous monitoring of RF impedance while degrading the solder joints under test due to fatigue cracking. The test results showed the RF impedance consistently increased as the solder joints were degraded due to the growth of cracks, and particle filtering predicted the time to failure of the interconnects similarly to their actual timesto- failure based on the early sensitivity of RF impedance.

  1. Metallic ureteral stents in malignant ureteral obstruction: clinical factors predicting stent failure.

    Science.gov (United States)

    Chow, Po-Ming; Hsu, Jui-Shan; Huang, Chao-Yuan; Wang, Shuo-Meng; Lee, Yuan-Ju; Huang, Kuo-How; Yu, Hong-Jheng; Pu, Yeong-Shiau; Liang, Po-Chin

    2014-06-01

    To provide clinical outcomes of the Resonance metallic ureteral stent in patients with malignant ureteral obstruction, as well as clinical factors predicting stent failure. Cancer patients who have received Resonance stents from July 2009 to March 2012 for ureteral obstruction were included for chart review. Stent failure was detected by clinical symptoms, image studies, and renal function tests. Survival analysis for stent duration was used to estimate patency rate and factors predicting stent failure. A total of 117 stents were inserted successfully into 94 ureteral units in 79 patients. There were no major complications. These stents underwent survival analysis and proportional hazard regression. The median duration for the stents was 5.77 months. In multivariate analysis, age (P=0.043), preoperative serum creatinine level (P=0.0174), and cancer type (P=0.0494) were significant factors associated with stent failure. Cancer treatment before and after stent insertion had no effect on stent duration. Resonance stents are effective and safe in relieving malignant ureteral obstructions. Old age and high serum creatinine level are predictors for stent failure. Stents in patients with lower gastrointestinal cancers have longer functional duration.

  2. Reliability prediction of engineering systems with competing failure modes due to component degradation

    International Nuclear Information System (INIS)

    Son, Young Kap

    2011-01-01

    Reliability of an engineering system depends on two reliability metrics: the mechanical reliability, considering component failures, that a functional system topology is maintained and the performance reliability of adequate system performance in each functional configuration. Component degradation explains not only the component aging processes leading to failure in function, but also system performance change over time. Multiple competing failure modes for systems with degrading components in terms of system functionality and system performance are considered in this paper with the assumption that system functionality is not independent of system performance. To reduce errors in system reliability prediction, this paper tries to extend system performance reliability prediction methods in open literature through combining system mechanical reliability from component reliabilities and system performance reliability. The extended reliability prediction method provides a useful way to compare designs as well as to determine effective maintenance policy for efficient reliability growth. Application of the method to an electro-mechanical system, as an illustrative example, is explained in detail, and the prediction results are discussed. Both mechanical reliability and performance reliability are compared to total system reliability in terms of reliability prediction errors

  3. Predicting Time Series Outputs and Time-to-Failure for an Aircraft Controller Using Bayesian Modeling

    Science.gov (United States)

    He, Yuning

    2015-01-01

    Safety of unmanned aerial systems (UAS) is paramount, but the large number of dynamically changing controller parameters makes it hard to determine if the system is currently stable, and the time before loss of control if not. We propose a hierarchical statistical model using Treed Gaussian Processes to predict (i) whether a flight will be stable (success) or become unstable (failure), (ii) the time-to-failure if unstable, and (iii) time series outputs for flight variables. We first classify the current flight input into success or failure types, and then use separate models for each class to predict the time-to-failure and time series outputs. As different inputs may cause failures at different times, we have to model variable length output curves. We use a basis representation for curves and learn the mappings from input to basis coefficients. We demonstrate the effectiveness of our prediction methods on a NASA neuro-adaptive flight control system.

  4. Clinical presentation at first heart failure hospitalization does not predict recurrent heart failure admission.

    Science.gov (United States)

    Kosztin, Annamaria; Costa, Jason; Moss, Arthur J; Biton, Yitschak; Nagy, Vivien Klaudia; Solomon, Scott D; Geller, Laszlo; McNitt, Scott; Polonsky, Bronislava; Merkely, Bela; Kutyifa, Valentina

    2017-11-01

    There are limited data on whether clinical presentation at first heart failure (HF) hospitalization predicts recurrent HF events. We aimed to assess predictors of recurrent HF hospitalizations in mild HF patients with an implantable cardioverter defibrillator or cardiac resynchronization therapy with defibrillator. Data on HF hospitalizations were prospectively collected for patients enrolled in MADIT-CRT. Predictors of recurrent HF hospitalization (HF2) after the first HF hospitalization were assessed using Cox proportional hazards regression models including baseline covariates and clinical presentation or management at first HF hospitalization. There were 193 patients with first HF hospitalization, and 156 patients with recurrent HF events. Recurrent HF rate after the first HF hospitalization was 43% at 1 year, 52% at 2 years, and 55% at 2.5 years. Clinical signs and symptoms, medical treatment, or clinical management of HF at first HF admission was not predictive for HF2. Baseline covariates predicting recurrent HF hospitalization included prior HF hospitalization (HR = 1.59, 95% CI: 1.15-2.20, P = 0.005), digitalis therapy (HR = 1.58, 95% CI: 1.13-2.20, P = 0.008), and left ventricular end-diastolic volume >240 mL (HR = 1.62, 95% CI: 1.17-2.25, P = 0.004). Recurrent HF events are frequent following the first HF hospitalization in patients with implanted implantable cardioverter defibrillator or cardiac resynchronization therapy with defibrillator. Neither clinical presentation nor clinical management during first HF admission was predictive of recurrent HF. Prior HF hospitalization, digitalis therapy, and left ventricular end-diastolic volume at enrolment predicted recurrent HF hospitalization, and these covariates could be used as surrogate markers for identifying a high-risk cohort. © 2017 The Authors. ESC Heart Failure published by John Wiley & Sons Ltd on behalf of the European Society of Cardiology.

  5. Scoring system based on electrocardiogram features to predict the type of heart failure in patients with chronic heart failure

    Directory of Open Access Journals (Sweden)

    Hendry Purnasidha Bagaswoto

    2016-12-01

    Full Text Available ABSTRACT Heart failure is divided into heart failure with reduced ejection fraction (HFrEF and heart failure with preserved ejection fraction (HFpEF. Additional studies are required to distinguish between these two types of HF. A previous study showed that HFrEF is less likely when ECG findings are normal. This study aims to create a scoring system based on ECG findings that will predict the type of HF. We performed a cross-sectional study analyzing ECG and echocardiographic data from 110 subjects. HFrEF was defined as an ejection fraction ≤40%. Fifty people were diagnosed with HFpEF and 60 people suffered from HFrEF. Multiple logistic regression analysis revealed certain ECG variables that were independent predictors of HFrEF i.e., LAH, QRS duration >100 ms, RBBB, ST-T segment changes and prolongation of the QT interval. Based on ROC curve analysis, we obtained a score for HFpEF of -1 to +3, while HFrEF had a score of +4 to +6 with 76% sensitivity, 96% specificity, 95% positive predictive value, an 80% negative predictive value and an accuracy of 86%. The scoring system derived from this study, including the presence or absence of LAH, QRS duration >100 ms, RBBB, ST-T segment changes and prolongation of the QT interval can be used to predict the type of HF with satisfactory sensitivity and specificity

  6. Comparison of the effects of oxycodone versus fentanyl on airway reflex to tracheal extubation and postoperative pain during anesthesia recovery after laparoscopic cholecystectomy: A double-blind, randomized clinical consort study.

    Science.gov (United States)

    Choi, Eun Kyung; Kwon, Nyeongkeon; Park, Sang-Jin

    2018-03-01

    Fentanyl has been suggested to be effective for controlling airway and hemodynamic responses to tracheal extubation. This study was performed to compare the effects of oxycodone and fentanyl on airway and hemodynamic responses and postoperative pain during the recovery period in patients undergoing laparoscopic cholecystectomy. Ninety patients aged 18 to 65 years were randomly allocated to 1 of 3 groups: fentanyl, oxycodone, and control. Coughing responses (incidence and severity), hemodynamic responses during the recovery period, and acute postoperative pain were assessed. The incidence of cough was decreased in the fentanyl and oxycodone groups compared with that in the control group at the points of awareness and extubation, and no significant difference was observed between the 2 treatment groups. Severe cough response was decreased in the fentanyl and oxycodone groups compared with that in the control group at the point of extubation, and no significant change was observed in cough severity between the 2 treatment groups. Postoperative pain scores were lower in the fentanyl and oxycodone groups than those in the control group at 5 and 30 minutes postoperatively, and no significant difference was observed between the 2 treatment groups. Hemodynamic responses did not differ among the 3 groups during the recovery period. Oxycodone treatment before tracheal extubation reduced cough response and was as effective as fentanyl treatment for improving extubation quality. Furthermore, single boluses of fentanyl and oxycodone showed equal effectiveness in attenuating acute postoperative pain in patients undergoing laparoscopic cholecystectomy.

  7. Microproteinuria Predicts Organ Failure in Patients Presenting with Acute Pancreatitis

    DEFF Research Database (Denmark)

    Bertilsson, Sara; Swärd, Per; Håkansson, Anders

    2016-01-01

    patients were included (14 % with organ failure; 6 % with severe AP). The α1-microglobulin-, albumin-, and IgG/creatinine ratios correlated with high-sensitivity C-reactive protein 48 h after admission (r = 0.47–0.61, p .... Urine samples were collected upon admission, 12–24 h after admission, and 3 months post-discharge for calculation of urine α1-microglobulin-, albumin-, IgG-, and IgM/creatinine ratios. Data regarding AP etiology, severity, and development of organ failure were registered. Results: Overall, 92 AP...... organ failure (p creatinine ratio upon admission predicted organ failure [adjusted odds ratio 1.286, 95 % confidence interval (CI) 1.024–1.614] with similar accuracy (AUROC 0.81, 95 % CI 0.69–0.94) as the more complex APACHE II score (AUROC 0.86, 95 % CI 0...

  8. Assessment of the de Hirsch Predictive Index Tests of Reading Failure.

    Science.gov (United States)

    Askov, Warren; And Others

    The predictive validity and the general usability of a battery of 10 tests reported by de Hirsch, Jansky, and Langford, the de Hirsch Predictive Index Tests of reading failure, were examined. The de Hirsch battery was administered to 433 kindergarten children in six public schools. When the pupils entered first grade, the Metropolitan Readiness…

  9. Prediction of immediate postoperative pain using the analgesia/nociception index: a prospective observational study.

    Science.gov (United States)

    Boselli, E; Bouvet, L; Bégou, G; Dabouz, R; Davidson, J; Deloste, J-Y; Rahali, N; Zadam, A; Allaouchiche, B

    2014-04-01

    The analgesia/nociception index (ANI) is derived from heart rate variability, ranging from 0 (maximal nociception) to 100 (maximal analgesia), to reflect the analgesia/nociception balance during general anaesthesia. This should be correlated with immediate postoperative pain in the post-anaesthesia care unit (PACU). The aim of this study was to evaluate the performance of ANI measured at arousal from general anaesthesia to predict immediate postoperative pain on arrival in PACU. Two hundred patients undergoing ear, nose, and throat or lower limb orthopaedic surgery with general anaesthesia using an inhalational agent and remifentanil were included in this prospective observational study. The ANI was measured immediately before tracheal extubation and pain intensity was assessed within 10 min of arrival in PACU using a 0-10 numerical rating scale (NRS). The relationship between ANI and NRS was assessed using linear regression. A receiver-operating characteristic (ROC) curve was used to evaluate the performance of ANI to predict NRS>3. A negative linear relationship was observed between ANI immediately before extubation and NRS on arrival in PACU. Using a threshold of 3 were both 86% with 92% negative predictive value, corresponding to an area under the ROC curve of 0.89. The measurement of ANI immediately before extubation after inhalation-remifentanil anaesthesia was significantly associated with pain intensity on arrival in PACU. The performance of ANI for the prediction of immediate postoperative pain is good and may assist physicians in optimizing acute pain management. ClinicalTrials.gov NCT01796249.

  10. Sonographical predictive markers of failure of induction of labour in term pregnancy.

    Science.gov (United States)

    Brik, Maia; Mateos, Silvia; Fernandez-Buhigas, Irene; Garbayo, Paloma; Costa, Gloria; Santacruz, Belen

    2017-02-01

    Predictive markers of failure of induction of labour in term pregnancy were evaluated. A prospective study including 245 women attending induction of labour was performed. The inclusion criteria were singleton pregnancies, gestational age 37-42 weeks and the main outcomes were failure of induction, induction to delivery interval and mode of delivery. Women with a longer cervical length prior to induction (CLpi) had a higher rate of failure of induction (30.9 ± 6.8 vs. 23.9 ± 9.3, p labour.

  11. The Predictive Value of Integrated Pulmonary Index after Off-Pump Coronary Artery Bypass Grafting: A Prospective Observational Study

    Directory of Open Access Journals (Sweden)

    Evgenia V. Fot

    2017-08-01

    Full Text Available BackgroundThe early warning scores may increase the safety of perioperative period. The objective of this study was to assess the diagnostic and predictive role of Integrated Pulmonary Index (IPI after off-pump coronary artery bypass grafting (OPCAB.Materials and MethodsForty adult patients undergoing elective OPCAB were enrolled into a single-center prospective observational study. We assessed respiratory function using IPI that includes oxygen saturation, end-tidal CO2, respiratory rate, and pulse rate. In addition, we evaluated blood gas analyses and hemodynamics, including ECG, invasive arterial pressure, and cardiac index. The measurements were performed after transfer to the intensive care unit, after spontaneous breathing trial and at 2, 6, 12, and 18 h after extubation.Results and DiscussionThe value of IPI registered during respiratory support correlated weakly with cardiac index (rho = 0.4; p = 0.04 and ScvO2 (rho = 0.4, p = 0.02. After extubation, IPI values decreased significantly, achieving a minimum by 18 h. The IPI value ≤9 at 6 h after extubation was a predictor of complicated early postoperative period (AUC = 0.71; p = 0.04 observed in 13 patients.ConclusionIn off-pump coronary surgery, the IPI decreases significantly after tracheal extubation and may predict postoperative complications.

  12. Improved failure prediction in forming simulations through pre-strain mapping

    Science.gov (United States)

    Upadhya, Siddharth; Staupendahl, Daniel; Heuse, Martin; Tekkaya, A. Erman

    2018-05-01

    The sensitivity of sheared edges of advanced high strength steel (AHSS) sheets to cracking during subsequent forming operations and the difficulty to predict this failure with any degree of accuracy using conventionally used FLC based failure criteria is a major problem plaguing the manufacturing industry. A possible method that allows for an accurate prediction of edge cracks is the simulation of the shearing operation and carryover of this model into a subsequent forming simulation. But even with an efficient combination of a solid element shearing operation and a shell element forming simulation, the need for a fine mesh, and the resulting high computation time makes this approach not viable from an industry point of view. The crack sensitivity of sheared edges is due to work hardening in the shear-affected zone (SAZ). A method to predict plastic strains induced by the shearing process is to measure the hardness after shearing and calculate the ultimate tensile strength as well as the flow stress. In combination with the flow curve, the relevant strain data can be obtained. To eliminate the time-intensive shearing simulation necessary to obtain the strain data in the SAZ, a new pre-strain mapping approach is proposed. The pre-strains to be mapped are, hereby, determined from hardness values obtained in the proximity of the sheared edge. To investigate the performance of this approach the ISO/TS 16630 hole expansion test was simulated with shell elements for different materials, whereby the pre-strains were mapped onto the edge of the hole. The hole expansion ratios obtained from such pre-strain mapped simulations are in close agreement with the experimental results. Furthermore, the simulations can be carried out with no increase in computation time, making this an interesting and viable solution for predicting edge failure due to shearing.

  13. Predicting Plan Failure by Monitoring Action Sequences and Duration

    Directory of Open Access Journals (Sweden)

    Giovani Parente FARIAS

    2017-07-01

    Full Text Available An agent can attempt to achieve multiple goals and each goal can be achieved by applying various different plans. Anticipating failures in agent plan execution is important to enable an agent to develop strategies to avoid or circumvent such failures, allowing the agent to achieve its goal. Plan recognition can be used to infer which plans are being executed from observations of sequences of activities being performed by an agent. Symbolic Plan Recognition is an algorithm that represents knowledge about the agents under observation in the form of a plan library. In this work, we use this symbolic algorithm to find out which plan the agent is performing and we develop a failure prediction system, based on information available in the plan library and in a simplified calendar which manages the goals the agent has to achieve. This failure predictor is able to monitor the sequence of agent actions and detects if an action is taking too long or does not match the plan that the agent was expected to be performing. We have successfully employed this approach in a health-care prototype system.

  14. Effects of Lignocaine Administered Intravenously or Intratracheally on Airway and Hemodynamic Responses during Emergence and Extubation in Patients Undergoing Elective Craniotomies in Supine Position.

    Science.gov (United States)

    Shabnum, Tabasum; Ali, Zulfiqar; Naqash, Imtiaz Ahmad; Mir, Aabid Hussain; Azhar, Khan; Zahoor, Syed Amer; Mir, Abdul Waheed

    2017-01-01

    Sympathoadrenergic responses during emergence and extubation can lead to an increase in heart rate (HR) and blood pressure whereas increased airway responses may lead to coughing and laryngospasm. The aim of our study was to compare the effects of lignocaine administered intravenously (IV) or intratracheally on airway and hemodynamic responses during emergence and extubation in patients undergoing elective craniotomies. Sixty patients with physical status American Society of Anaesthesiologists Classes I and II aged 18-70 years, scheduled to undergo elective craniotomies were included. The patients were randomly divided into three groups of twenty patients; Group 1 receiving IV lignocaine and intratracheal placebo (IV group), Group 2 receiving intratracheal lignocaine and IV placebo (I/T group), and Group 3 receiving IV and intratracheal placebo (placebo group). The tolerance to the endotracheal tube was monitored, and number of episodes of cough was recorded during emergence and at the time of extubation. Hemodynamic parameters such as HR and blood pressure (systolic, diastolic, mean arterial pressure) were also recorded. There was a decrease of HR in both IV and intratracheal groups in comparison with placebo group ( P < 0.005). Rise in blood pressure (systolic blood pressure, diastolic blood pressure and mean arterial pressure) was comparable in both Groups 1 and 2 but was lower in comparison with placebo group ( P < 0.005). Cough suppression was comparable in all the three groups. Grade III cough (15%) was documented only in placebo group. Both IV and intratracheal lignocaine are effective in attenuation of hemodynamic response if given within 20 min from skull pin removal to extubation. There was comparable cough suppression through intratracheal route and IV routes than the placebo group.

  15. Micromechanics-based damage model for failure prediction in cold forming

    Energy Technology Data Exchange (ETDEWEB)

    Lu, X.Z.; Chan, L.C., E-mail: lc.chan@polyu.edu.hk

    2017-04-06

    The purpose of this study was to develop a micromechanics-based damage (micro-damage) model that was concerned with the evolution of micro-voids for failure prediction in cold forming. Typical stainless steel SS316L was selected as the specimen material, and the nonlinear isotropic hardening rule was extended to describe the large deformation of the specimen undergoing cold forming. A micro-focus high-resolution X-ray computed tomography (CT) system was employed to trace and measure the micro-voids inside the specimen directly. Three-dimensional (3D) representative volume element (RVE) models with different sizes and spatial locations were reconstructed from the processed CT images of the specimen, and the average size and volume fraction of micro-voids (VFMV) for the specimen were determined via statistical analysis. Subsequently, the micro-damage model was compiled as a user-defined material subroutine into the finite element (FE) package ABAQUS. The stress-strain responses and damage evolutions of SS316L specimens under tensile and compressive deformations at different strain rates were predicted and further verified experimentally. It was concluded that the proposed micro-damage model is convincing for failure prediction in cold forming of the SS316L material.

  16. The prediction problems of VVER fuel element cladding failure theory

    International Nuclear Information System (INIS)

    Pelykh, S.N.; Maksimov, M.V.; Ryabchikov, S.D.

    2016-01-01

    Highlights: • Fuel cladding failure forecasting is based on the fuel load history and the damage distribution. • The limit damage parameter is exceeded, though limit stresses are not reached. • The damage parameter plays a significant role in predicting the cladding failure. • The proposed failure probability criterion can be used to control the cladding tightness. - Abstract: A method for forecasting of VVER fuel element (FE) cladding failure due to accumulation of deformation damage parameter, taking into account the fuel assembly (FA) loading history and the damage parameter distribution among FEs included in the FA, has been developed. Using the concept of conservative FE groups, it is shown that the safety limit for damage parameter is exceeded for some FA rearrangement, though the limits for circumferential and equivalent stresses are not reached. This new result contradicts the wide-spread idea that the damage parameter value plays a minor role when estimating the limiting state of cladding. The necessary condition of rearrangement algorithm admissibility and the criterion for minimization of the probability of cladding failure due to damage parameter accumulation have been derived, for using in automated systems controlling the cladding tightness.

  17. Failure Predictions for Graphite Reflector Bricks in the Very High Temperature Reactor with the Prismatic Core Design

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Gyanender, E-mail: sing0550@umn.edu [Department of Mechanical Engineering, University of Minnesota, 111, Church St. SE, Minneapolis, MN 55455 (United States); Fok, Alex [Minnesota Dental Research in Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, 515, Delaware St. SE, Minneapolis, MN 55455 (United States); Department of Mechanical Engineering, University of Minnesota, 111, Church St. SE, Minneapolis, MN 55455 (United States); Mantell, Susan [Department of Mechanical Engineering, University of Minnesota, 111, Church St. SE, Minneapolis, MN 55455 (United States)

    2017-06-15

    Highlights: • Failure probability of VHTR reflector bricks predicted though crack modeling. • Criterion chosen for defining failure strongly affects the predictions. • Breaching of the CRC could be significantly delayed through crack arrest. • Capability to predict crack initiation and propagation demonstrated. - Abstract: Graphite is used in nuclear reactor cores as a neutron moderator, reflector and structural material. The dimensions and physical properties of graphite change when it is exposed to neutron irradiation. The non-uniform changes in the dimensions and physical properties lead to the build-up of stresses over the course of time in the core components. When the stresses reach the critical limit, i.e. the strength of the material, cracking occurs and ultimately the components fail. In this paper, an explicit crack modeling approach to predict the probability of failure of a VHTR prismatic reactor core reflector brick is presented. Firstly, a constitutive model for graphite is constructed and used to predict the stress distribution in the reflector brick under in-reactor conditions of high temperature and irradiation. Fracture simulations are performed as part of a Monte Carlo analysis to predict the probability of failure. Failure probability is determined based on two different criteria for defining failure time: A) crack initiation and B) crack extension to near control rod channel. A significant difference is found between the failure probabilities based on the two criteria. It is predicted that the reflector bricks will start cracking during the time range of 5–9 years, while breaching of the control rod channels will occur during the period of 11–16 years. The results show that, due to crack arrest, there is a significantly delay between crack initiation and breaching of the control rod channel.

  18. Echocardiographic evaluation and N-terminal pro-brain natriuretic peptide measurement of patients hospitalized for heart failure during weaning from mechanical ventilation.

    Science.gov (United States)

    Gerbaud, E; Erickson, M; Grenouillet-Delacre, M; Beauvieux, M-C; Coste, P; Durrieu-Jaïs, C; Hilbert, G; Castaing, Y; Vargas, F

    2012-04-01

    Weaning patients with heart failure who have required mechanical ventilation remains challenging. We evaluated echocardiographic indexes and N-terminal pro-brain natriuretic peptide (NT-proBNP) as markers of acute cardiac dysfunction before and after spontaneous breathing trials (SBT) in such patients to assess their ability to predict subsequent successful extubation. Forty-four patients who underwent their first SBT were prospectively included. Plasma levels of NT-proBNP and transthoracic echocardiography indices including cardiac index, E/A ratio and E/Ea ratio were recorded immediately before commencing and just before the end of SBT. Ten patients (22.7%) failed their SBT. No significant difference was observed concerning baseline echocardiographic data and NT-proBNP level between the patients who succeeded the SBT or those that failed. Cardiac index increased significantly at end-SBT in patients who passed (3.3 [3.06-3.77] vs. 3 [2.68-3.3] L/min/m(2), Pfailed. E/Ea ratio (16.8 [8.5-27.3] vs. 10.7 [6.7-20.5], P=0.006) and NT-proBNP level (8199 [3106-10949] vs. 4200 [1855-7125] pg/mL, P=0.004) increased significantly in those who failed the SBT, in contrast to the weaning success group where they remained unchanged. Neither NT-proBNP level nor the studied echocardiographic indices before SBT were able to predict SBT outcome in patients presenting with severe heart failure. Failure to increase the cardiac index and increases in both E/Ea ratio and NT-proBNP levels were seen at end-SBT in patients who failed the SBT, and may reflect failure of myocardial reserve to cope with the stress of SBT.

  19. Randomised trial of elective continuous positive airway pressure (CPAP) compared with rescue CPAP after extubation

    OpenAIRE

    Robertson, N; Hamilton, P

    1998-01-01

    AIM—To determine if a weaning regimen on flow driver continuous positive airway pressure (CPAP) would decrease the number of ventilator days but increase the number of CPAP days when compared with a rescue regimen.
METHODS—Fifty eight babies of 24-32 weeks gestation with respiratory distress syndrome (RDS) were studied prospectively. After extubation they were randomly allocated to receive CPAP for 72 hours (n=29) according to a weaning regimen, or were placed in headbox ...

  20. Early Shear Failure Prediction in Incremental Sheet Forming Process Using FEM and ANN

    Science.gov (United States)

    Moayedfar, Majid; Hanaei, Hengameh; Majdi Rani, Ahmad; Musa, Mohd Azam Bin; Sadegh Momeni, Mohammad

    2018-03-01

    The application of incremental sheet forming process as a rapid forming technique is rising in variety of industries such as aerospace, automotive and biomechanical purposes. However, the sheet failure is a big challenge in this process which leads wasting lots of materials. Hence, this study tried to propose a method to predict the early sheet failure in this process using mathematical solution. For the feasibility of the study, design of experiment with the respond surface method is employed to extract a set of experiments data for the simulation. The significant forming parameters were recognized and their integration was used for prediction system. Then, the results were inserted to the artificial neural network as input parameters to predict a vast range of applicable parameters avoiding sheet failure in ISF. The value of accuracy R2 ∼0.93 was obtained and the maximum sheet stretch in the depth of 25mm were recorded. The figures generate from the trend of interaction between effective parameters were provided for future studies.

  1. Infant flow biphasic nasal continuous positive airway pressure (BP- NCPAP vs. infant flow NCPAP for the facilitation of extubation in infants' ≤ 1,250 grams: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    O'Brien Karel

    2012-04-01

    Full Text Available Abstract Background The use of mechanical ventilation is associated with lung injury in preterm infants and therefore the goal is to avoid or minimize its use. To date there is very little consensus on what is considered the "best non-invasive ventilation mode" to be used post-extubation. The objective of this study was to compare the effectiveness of biphasic nasal continuous positive airway pressure (BP-NCPAP vs. NCPAP in facilitating sustained extubation in infants ≤ 1,250 grams. Methods We performed a randomized controlled trial of BP-NCPAP vs. NCPAP in infants ≤ 1,250 grams extubated for the first time following mechanical ventilation since birth. Infants were extubated using preset criteria or at the discretion of the attending neonatologist. The primary outcome was the incidence of sustained extubation for 7 days. Secondary outcomes included incidence of adverse events and short-term neonatal outcomes. Results Sixty-seven infants received BP-NCPAP and 69 NCPAP. Baseline characteristics were similar between groups. The trial was stopped early due to increased use of non-invasive ventilation from birth, falling short of our calculated sample size of 141 infants per group. The incidence of sustained extubation was not statistically different between the BP-NCPAP vs. NCPAP group (67% vs. 58%, P = 0.27. The incidence of adverse events and short-term neonatal outcomes were similar between the two groups (P > 0.05 except for retinopathy of prematurity which was noted to be higher (P = 0.02 in the BP-NCPAP group. Conclusions Biphasic NCPAP may be used to assist in weaning from mechanical ventilation. The effectiveness and safety of BP-NCPAP compared to NCPAP needs to be confirmed in a large multi-center trial as our study conclusions are limited by inadequate sample size. Clinical Trials Registration # NCT00308789 Source of support Grant # 06-06, Physicians Services Incorporated Foundation, Toronto, Canada. Summit technologies Inc. provided

  2. Modeling of Failure Prediction Bayesian Network with Divide-and-Conquer Principle

    Directory of Open Access Journals (Sweden)

    Zhiqiang Cai

    2014-01-01

    Full Text Available For system failure prediction, automatically modeling from historical failure dataset is one of the challenges in practical engineering fields. In this paper, an effective algorithm is proposed to build the failure prediction Bayesian network (FPBN model with data mining technology. First, the conception of FPBN is introduced to describe the state of components and system and the cause-effect relationships among them. The types of network nodes, the directions of network edges, and the conditional probability distributions (CPDs of nodes in FPBN are discussed in detail. According to the characteristics of nodes and edges in FPBN, a divide-and-conquer principle based algorithm (FPBN-DC is introduced to build the best FPBN network structures of different types of nodes separately. Then, the CPDs of nodes in FPBN are calculated by the maximum likelihood estimation method based on the built network. Finally, a simulation study of a helicopter convertor model is carried out to demonstrate the application of FPBN-DC. According to the simulations results, the FPBN-DC algorithm can get better fitness value with the lower number of iterations, which verified its effectiveness and efficiency compared with traditional algorithm.

  3. Noninvasive Positive Pressure Ventilation for Acute Respiratory Failure Patients With Chronic Obstructive Pulmonary Disease (COPD)

    Science.gov (United States)

    McCurdy, BR

    2012-01-01

    literature search was performed on December 3, 2010 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, OVID EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), Wiley Cochrane, and the Centre for Reviews and Dissemination/International Agency for Health Technology Assessment (INAHTA) for studies published from January 1, 2004 until December 3, 2010. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Since there were numerous studies that examined the effectiveness of NPPV for the treatment of ARF due to exacerbations of COPD published before 2004, pre-2004 trials which met the inclusion/exclusion criteria for this evidence-based review were identified by hand-searching reference lists of included studies and systematic reviews. Inclusion Criteria English language full-reports; health technology assessments, systematic reviews, meta-analyses, and randomized controlled trials (RCTs); studies performed exclusively in patients with a diagnosis of COPD or studies performed with patients with a mix of conditions if results are reported for COPD patients separately; patient population: (Question 1) patients with acute hypercapnic respiratory failure due to an exacerbation of COPD; (Question 2a) COPD patients being weaned from IMV; (Questions 2b and 2c) COPD patients who have been extubated from IMV. Exclusion Criteria COPD NPPV Plus Usual Medical Care Versus Usual Medical Care Alone for First Line Treatment A total of 1,000 participants were included in 11 RCTs1; the sample size ranged from 23 to 342. The mean age of the participants ranged from approximately 60 to 72 years of age. Based on either the Global Initiative for Chronic Obstructive Lung Disease (GOLD) COPD stage criteria or the mean percent predicted forced expiratory volume in 1 second

  4. Presenting hydrothorax predicts failure of needle aspiration in primary spontaneous pneumothorax.

    Science.gov (United States)

    Wu, Kwok Kei; Lui, Chun Tat; Ho, Chik Leung; Tsui, Kwok Leung; Fung, Hin Tat

    2016-06-01

    The objective was to evaluate if existence of hydrothorax in initial chest radiograph predicts treatment outcome in patients with primary spontaneous pneumothorax who received needle thoracostomy. This is a retrospective cohort study carried out from January 2011 to August 2014 in 1 public hospital in Hong Kong. All consecutive adult patients aged 18years or above who attended the emergency department with the diagnosis of primary spontaneous pneumothorax with needle aspiration performed as primary treatment were included. Age, smoking status, size of pneumothorax, previous history of pneumothorax, aspirated gas volume and presence of hydropneumothorax in initial radiograph were included in the analysis. The outcome was success or failure of the needle aspiration. Logistic regression was used to identify the predicting factors of failure of needle aspiration. There were a total of 127 patients included. Seventy-three patients (57.5%) were successfully treated with no recurrence upon discharge. Among 54 failure cases, 13 patients (10.2%) failed immediately after procedure as evident by chest radiograph and required second treatment. Forty-one patients (32.3%) failed upon subsequent chest radiographs. Multivariate logistic regression showed factors independently associated with the failure of needle aspiration, which included hydropneumothorax in the initial radiograph (odds ratio [OR]=4.47 [1.56i12.83], P=.005), previous history of pneumothorax (OR=3.92 [1.57-9.79], P=.003), and large size of pneumothorax defined as apex-to-cupola distance ≥5cm (OR=2.75 [1.21-6.26], P=.016). Hydropneumothorax, previous history of pneumothorax, and large size were independent predictors of failure of needle aspiration in treatment of primary spontaneous pneumothorax. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Failures and suggestions in Earthquake forecasting and prediction

    Science.gov (United States)

    Sacks, S. I.

    2013-12-01

    Seismologists have had poor success in earthquake prediction. However, wide ranging observations from earlier great earthquakes show that precursory data can exist. In particular, two aspects seem promising. In agreement with simple physical modeling, b-values decrease in highly loaded fault zones for years before failure. Potentially more usefully, in high stress regions, breakdown of dilatant patches leading to failure can yield expelled water-related observations. The volume increase (dilatancy) caused by high shear stresses decreases the pore pressure. Eventually, water flows back in restoring the pore pressure, promoting failure and expelling the extra water. Of course, in a generally stressed region there may be many small patches that fail, such as observed before the 1975 Haicheng earthquake. Only a few days before the major event will most of the dilatancy breakdown occur in the fault zone itself such as for the Tangshan, 1976 destructive event. Observations of 'water release' effects have been observed before the 1923 great Kanto earthquake, the 1984 Yamasaki event, the 1975 Haicheng and the 1976 Tangshan earthquakes and also the 1995 Kobe earthquake. While there are obvious difficulties in water release observations, not least because there is currently no observational network anywhere, historical data does suggest some promise if we broaden our approach to this difficult subject.

  6. Sensitivity, Specificity, Predictive Values, and Accuracy of Three Diagnostic Tests to Predict Inferior Alveolar Nerve Blockade Failure in Symptomatic Irreversible Pulpitis

    Directory of Open Access Journals (Sweden)

    Daniel Chavarría-Bolaños

    2017-01-01

    Full Text Available Introduction. The inferior alveolar nerve block (IANB is the most common anesthetic technique used on mandibular teeth during root canal treatment. Its success in the presence of preoperative inflammation is still controversial. The aim of this study was to evaluate the sensitivity, specificity, predictive values, and accuracy of three diagnostic tests used to predict IANB failure in symptomatic irreversible pulpitis (SIP. Methodology. A cross-sectional study was carried out on the mandibular molars of 53 patients with SIP. All patients received a single cartridge of mepivacaine 2% with 1 : 100000 epinephrine using the IANB technique. Three diagnostic clinical tests were performed to detect anesthetic failure. Anesthetic failure was defined as a positive painful response to any of the three tests. Sensitivity, specificity, predictive values, accuracy, and ROC curves were calculated and compared and significant differences were analyzed. Results. IANB failure was determined in 71.7% of the patients. The sensitivity scores for the three tests (lip numbness, the cold stimuli test, and responsiveness during endodontic access were 0.03, 0.35, and 0.55, respectively, and the specificity score was determined as 1 for all of the tests. Clinically, none of the evaluated tests demonstrated a high enough accuracy (0.30, 0.53, and 0.68 for lip numbness, the cold stimuli test, and responsiveness during endodontic access, resp.. A comparison of the areas under the curve in the ROC analyses showed statistically significant differences between the three tests (p<0.05. Conclusion. None of the analyzed tests demonstrated a high enough accuracy to be considered a reliable diagnostic tool for the prediction of anesthetic failure.

  7. Good Models Gone Bad: Quantifying and Predicting Parameter-Induced Climate Model Simulation Failures

    Science.gov (United States)

    Lucas, D. D.; Klein, R.; Tannahill, J.; Brandon, S.; Covey, C. C.; Domyancic, D.; Ivanova, D. P.

    2012-12-01

    Simulations using IPCC-class climate models are subject to fail or crash for a variety of reasons. Statistical analysis of the failures can yield useful insights to better understand and improve the models. During the course of uncertainty quantification (UQ) ensemble simulations to assess the effects of ocean model parameter uncertainties on climate simulations, we experienced a series of simulation failures of the Parallel Ocean Program (POP2). About 8.5% of our POP2 runs failed for numerical reasons at certain combinations of parameter values. We apply support vector machine (SVM) classification from the fields of pattern recognition and machine learning to quantify and predict the probability of failure as a function of the values of 18 POP2 parameters. The SVM classifiers readily predict POP2 failures in an independent validation ensemble, and are subsequently used to determine the causes of the failures via a global sensitivity analysis. Four parameters related to ocean mixing and viscosity are identified as the major sources of POP2 failures. Our method can be used to improve the robustness of complex scientific models to parameter perturbations and to better steer UQ ensembles. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and was funded by the Uncertainty Quantification Strategic Initiative Laboratory Directed Research and Development Project at LLNL under project tracking code 10-SI-013 (UCRL LLNL-ABS-569112).

  8. Predicting failure response of spot welded joints using recent extensions to the Gurson model

    DEFF Research Database (Denmark)

    Nielsen, Kim Lau

    2010-01-01

    The plug failure modes of resistance spot welded shear-lab and cross-tension test specimens are studied, using recent extensions to the Gurson model. A comparison of the predicted mechanical response is presented when using either: (i) the Gurson-Tvergaard-Needleman model (GTN-model), (ii...... is presented. The models are applied to predict failure of specimens containing a fully intact weld nugget as well as a partly removed weld nugget to address the problems of shrinkage voids or larger weld defects. All analysis are carried out by full 3D finite element modelling....

  9. A model for predicting pellet-cladding interaction induced fuel rod failure, based on nonlinear fracture mechanics

    International Nuclear Information System (INIS)

    Jernkvist, L.O.

    1993-01-01

    A model for predicting pellet-cladding mechanical interaction induced fuel rod failure, suitable for implementation in finite element fuel-performance codes, is presented. Cladding failure is predicted by explicitly modelling the propagation of radial cracks under varying load conditions. Propagation is assumed to be due to either iodine induced stress corrosion cracking or ductile fracture. Nonlinear fracture mechanics concepts are utilized in modelling these two mechanisms of crack growth. The novelty of this approach is that the development of cracks, which may ultimately lead to fuel rod failure, can be treated as a dynamic and time-dependent process. The influence of cyclic loading, ramp rates and material creep on the failure mechanism can thereby be investigated. Results of numerical calculations, in which the failure model has been used to study the dependence of cladding creep rate on crack propagation velocity, are presented. (author)

  10. Assessment of heart rate, acidosis, consciousness, oxygenation, and respiratory rate to predict noninvasive ventilation failure in hypoxemic patients.

    Science.gov (United States)

    Duan, Jun; Han, Xiaoli; Bai, Linfu; Zhou, Lintong; Huang, Shicong

    2017-02-01

    To develop and validate a scale using variables easily obtained at the bedside for prediction of failure of noninvasive ventilation (NIV) in hypoxemic patients. The test cohort comprised 449 patients with hypoxemia who were receiving NIV. This cohort was used to develop a scale that considers heart rate, acidosis, consciousness, oxygenation, and respiratory rate (referred to as the HACOR scale) to predict NIV failure, defined as need for intubation after NIV intervention. The highest possible score was 25 points. To validate the scale, a separate group of 358 hypoxemic patients were enrolled in the validation cohort. The failure rate of NIV was 47.8 and 39.4% in the test and validation cohorts, respectively. In the test cohort, patients with NIV failure had higher HACOR scores at initiation and after 1, 12, 24, and 48 h of NIV than those with successful NIV. At 1 h of NIV the area under the receiver operating characteristic curve was 0.88, showing good predictive power for NIV failure. Using 5 points as the cutoff value, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy for NIV failure were 72.6, 90.2, 87.2, 78.1, and 81.8%, respectively. These results were confirmed in the validation cohort. Moreover, the diagnostic accuracy for NIV failure exceeded 80% in subgroups classified by diagnosis, age, or disease severity and also at 1, 12, 24, and 48 h of NIV. Among patients with NIV failure with a HACOR score of >5 at 1 h of NIV, hospital mortality was lower in those who received intubation at ≤12 h of NIV than in those intubated later [58/88 (66%) vs. 138/175 (79%); p = 0.03). The HACOR scale variables are easily obtained at the bedside. The scale appears to be an effective way of predicting NIV failure in hypoxemic patients. Early intubation in high-risk patients may reduce hospital mortality.

  11. A Model to Predict Student Failure in the First Year of the Undergraduate Medical Curriculum

    Directory of Open Access Journals (Sweden)

    Gerard J.A. Baars

    2017-06-01

    Discussion: The earliest moment with the highest specificity to predict student failure in the first-year curriculum seems to be at 6 months. However, additional factors are needed to improve this prediction or to bring forward the predictive moment.

  12. Aberrant GSTP1 promoter methylation predicts short-term prognosis in acute-on-chronic hepatitis B liver failure.

    Science.gov (United States)

    Gao, S; Sun, F-K; Fan, Y-C; Shi, C-H; Zhang, Z-H; Wang, L-Y; Wang, K

    2015-08-01

    Glutathione-S-transferase P1 (GSTP1) methylation has been demonstrated to be associated with oxidative stress induced liver damage in acute-on-chronic hepatitis B liver failure (ACHBLF). To evaluate the methylation level of GSTP1 promoter in acute-on-chronic hepatitis B liver failure and determine its predictive value for prognosis. One hundred and five patients with acute-on-chronic hepatitis B liver failure, 86 with chronic hepatitis B (CHB) and 30 healthy controls (HC) were retrospectively enrolled. GSTP1 methylation level in peripheral mononuclear cells (PBMC) was detected by MethyLight. Clinical and laboratory parameters were obtained. GSTP1 methylation levels were significantly higher in patients with acute-on-chronic hepatitis B liver failure (median 16.84%, interquartile range 1.83-59.05%) than those with CHB (median 1.25%, interquartile range 0.48-2.47%; P chronic hepatitis B liver failure group, nonsurvivors showed significantly higher GSTP1 methylation levels (P chronic hepatitis B liver failure, GSTP1 methylation showed significantly better predictive value than MELD score [area under the receiver operating characteristic curve (AUC) 0.89 vs. 0.72, P chronic hepatitis B liver failure and shows high predictive value for short-term mortality. It might serve as a potential prognostic marker for acute-on-chronic hepatitis B liver failure. © 2015 John Wiley & Sons Ltd.

  13. Prediction of Brittle Failure for TBM Tunnels in Anisotropic Rock: A Case Study from Northern Norway

    Science.gov (United States)

    Dammyr, Øyvind

    2016-06-01

    Prediction of spalling and rock burst is especially important for hard rock TBM tunneling, because failure can have larger impact than in a drill and blast tunnel and ultimately threaten excavation feasibility. The majority of research on brittle failure has focused on rock types with isotropic behavior. This paper gives a review of existing theory and its application before a 3.5-m-diameter TBM tunnel in foliated granitic gneiss is used as a case to study brittle failure characteristics of anisotropic rock. Important aspects that should be considered in order to predict brittle failure in anisotropic rock are highlighted. Foliation is responsible for considerable strength anisotropy and is believed to influence the preferred side of v-shaped notch development in the investigated tunnel. Prediction methods such as the semi- empirical criterion, the Hoek- Brown brittle parameters, and the non-linear damage initiation and spalling limit method give reliable results; but only as long as the angle between compression axis and foliation in uniaxial compressive tests is relevant, dependent on the relation between tunnel trend/plunge, strike/dip of foliation, and tunnel boundary stresses. It is further demonstrated that local in situ stress variations, for example, due to the presence of discontinuities, can have profound impact on failure predictions. Other carefully documented case studies into the brittle failure nature of rock, in particular anisotropic rock, are encouraged in order to expand the existing and relatively small database. This will be valuable for future TBM planning and construction stages in highly stressed brittle anisotropic rock.

  14. A standardized model for predicting flap failure using indocyanine green dye

    Science.gov (United States)

    Zimmermann, Terence M.; Moore, Lindsay S.; Warram, Jason M.; Greene, Benjamin J.; Nakhmani, Arie; Korb, Melissa L.; Rosenthal, Eben L.

    2016-03-01

    Techniques that provide a non-invasive method for evaluation of intraoperative skin flap perfusion are currently available but underutilized. We hypothesize that intraoperative vascular imaging can be used to reliably assess skin flap perfusion and elucidate areas of future necrosis by means of a standardized critical perfusion threshold. Five animal groups (negative controls, n=4; positive controls, n=5; chemotherapy group, n=5; radiation group, n=5; chemoradiation group, n=5) underwent pre-flap treatments two weeks prior to undergoing random pattern dorsal fasciocutaneous flaps with a length to width ratio of 2:1 (3 x 1.5 cm). Flap perfusion was assessed via laser-assisted indocyanine green dye angiography and compared to standard clinical assessment for predictive accuracy of flap necrosis. For estimating flap-failure, clinical prediction achieved a sensitivity of 79.3% and a specificity of 90.5%. When average flap perfusion was more than three standard deviations below the average flap perfusion for the negative control group at the time of the flap procedure (144.3+/-17.05 absolute perfusion units), laser-assisted indocyanine green dye angiography achieved a sensitivity of 81.1% and a specificity of 97.3%. When absolute perfusion units were seven standard deviations below the average flap perfusion for the negative control group, specificity of necrosis prediction was 100%. Quantitative absolute perfusion units can improve specificity for intraoperative prediction of viable tissue. Using this strategy, a positive predictive threshold of flap failure can be standardized for clinical use.

  15. Hybrid neural intelligent system to predict business failure in small-to-medium-size enterprises.

    Science.gov (United States)

    Borrajo, M Lourdes; Baruque, Bruno; Corchado, Emilio; Bajo, Javier; Corchado, Juan M

    2011-08-01

    During the last years there has been a growing need of developing innovative tools that can help small to medium sized enterprises to predict business failure as well as financial crisis. In this study we present a novel hybrid intelligent system aimed at monitoring the modus operandi of the companies and predicting possible failures. This system is implemented by means of a neural-based multi-agent system that models the different actors of the companies as agents. The core of the multi-agent system is a type of agent that incorporates a case-based reasoning system and automates the business control process and failure prediction. The stages of the case-based reasoning system are implemented by means of web services: the retrieval stage uses an innovative weighted voting summarization of self-organizing maps ensembles-based method and the reuse stage is implemented by means of a radial basis function neural network. An initial prototype was developed and the results obtained related to small and medium enterprises in a real scenario are presented.

  16. Study on real-time elevator brake failure predictive system

    Science.gov (United States)

    Guo, Jun; Fan, Jinwei

    2013-10-01

    This paper presented a real-time failure predictive system of the elevator brake. Through inspecting the running state of the coil by a high precision long range laser triangulation non-contact measurement sensor, the displacement curve of the coil is gathered without interfering the original system. By analyzing the displacement data using the diagnostic algorithm, the hidden danger of the brake system can be discovered in time and thus avoid the according accident.

  17. Identifying the necessary and sufficient number of risk factors for predicting academic failure.

    Science.gov (United States)

    Lucio, Robert; Hunt, Elizabeth; Bornovalova, Marina

    2012-03-01

    Identifying the point at which individuals become at risk for academic failure (grade point average [GPA] academic success or failure. This study focused on 12 school-related factors. Using a thorough 5-step process, we identified which unique risk factors place one at risk for academic failure. Academic engagement, academic expectations, academic self-efficacy, homework completion, school relevance, school safety, teacher relationships (positive relationship), grade retention, school mobility, and school misbehaviors (negative relationship) were uniquely related to GPA even after controlling for all relevant covariates. Next, a receiver operating characteristic curve was used to determine a cutoff point for determining how many risk factors predict academic failure (GPA academic failure, which provides a way for early identification of individuals who are at risk. Further implications of these findings are discussed. PsycINFO Database Record (c) 2012 APA, all rights reserved.

  18. Prediction of late failure after medical abortion from serial beta-hCG measurements and ultrasonography

    DEFF Research Database (Denmark)

    Rørbye, C; Nørgaard, M; Nilas, Lisbeth

    2004-01-01

    BACKGROUND: Surgical treatment of failed medical abortion may be performed several weeks after initiation of the abortion. There are no recognized methods for early identification of these late failures. We assessed the prognostic values of beta-hCG and ultrasonography in predicting late failure ...

  19. Probability of failure prediction for step-stress fatigue under sine or random stress

    Science.gov (United States)

    Lambert, R. G.

    1979-01-01

    A previously proposed cumulative fatigue damage law is extended to predict the probability of failure or fatigue life for structural materials with S-N fatigue curves represented as a scatterband of failure points. The proposed law applies to structures subjected to sinusoidal or random stresses and includes the effect of initial crack (i.e., flaw) sizes. The corrected cycle ratio damage function is shown to have physical significance.

  20. A New Material Constitutive Model for Predicting Cladding Failure

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Joe; Dunham, Robert [ANATECH Corp., San Diego, CA (United States); Rashid, Mark [University of California Davis, Davis, CA (United States); Machiels, Albert [EPRI, Palo Alto, CA (United States)

    2009-06-15

    An important issue in fuel performance and safety evaluations is the characterization of the effects of hydrides on cladding mechanical response and failure behavior. The hydride structure formed during power operation transforms the cladding into a complex multi-material composite, with through-thickness concentration profile that causes cladding ductility to vary by more than an order of magnitude between ID and OD. However, current practice of mechanical property testing treats the cladding as a homogeneous material characterized by a single stress-strain curve, regardless of its hydride morphology. Consequently, as irradiation conditions and hydrides evolution change, new material property testing is required, which results in a state of continuous need for valid material property data. A recently developed constitutive model, treats the cladding as a multi-material composite in which the metal and the hydride platelets are treated as separate material phases with their own elastic-plastic and fracture properties and interacting at their interfaces with appropriate constraint conditions between them to ensure strain and stress compatibility. An essential feature of the model is a multi-phase damage formulation that models the complex interaction between the hydride phases and the metal matrix and the coupled effect of radial and circumferential hydrides on cladding stress-strain response. This gives the model the capability of directly predicting cladding failure progression during the loading event and, as such, provides a unique tool for constructing failure criteria analytically where none could be developed by conventional material testing. Implementation of the model in a fuel behavior code provides the capability to predict in-reactor operational failures due to PCI or missing pellet surfaces (MPS) without having to rely on failure criteria. Even, a stronger motivation for use of the model is in the transportation accidents analysis of spent fuel

  1. Echocardiography and risk prediction in advanced heart failure: incremental value over clinical markers.

    Science.gov (United States)

    Agha, Syed A; Kalogeropoulos, Andreas P; Shih, Jeffrey; Georgiopoulou, Vasiliki V; Giamouzis, Grigorios; Anarado, Perry; Mangalat, Deepa; Hussain, Imad; Book, Wendy; Laskar, Sonjoy; Smith, Andrew L; Martin, Randolph; Butler, Javed

    2009-09-01

    Incremental value of echocardiography over clinical parameters for outcome prediction in advanced heart failure (HF) is not well established. We evaluated 223 patients with advanced HF receiving optimal therapy (91.9% angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, 92.8% beta-blockers, 71.8% biventricular pacemaker, and/or defibrillator use). The Seattle Heart Failure Model (SHFM) was used as the reference clinical risk prediction scheme. The incremental value of echocardiographic parameters for event prediction (death or urgent heart transplantation) was measured by the improvement in fit and discrimination achieved by addition of standard echocardiographic parameters to the SHFM. After a median follow-up of 2.4 years, there were 38 (17.0%) events (35 deaths; 3 urgent transplants). The SHFM had likelihood ratio (LR) chi(2) 32.0 and C statistic 0.756 for event prediction. Left ventricular end-systolic volume, stroke volume, and severe tricuspid regurgitation were independent echocardiographic predictors of events. The addition of these parameters to SHFM improved LR chi(2) to 72.0 and C statistic to 0.866 (P advanced HF.

  2. Tumor Necrosis Factor Inhibitor Primary Failure Predicts Decreased Ustekinumab Efficacy in Psoriasis Patients.

    Science.gov (United States)

    Sorensen, Eric P; Fanucci, Kristina A; Saraiya, Ami; Volf, Eva; Au, Shiu-chung; Argobi, Yahya; Mansfield, Ryan; Gottlieb, Alice B

    2015-08-01

    Additional studies are needed to examine the efficacy of ustekinumab in psoriasis patients who have previously been exposed to tumor necrosis factor inhibitors (TNFi). To examine the predictive effect of TNFi primary failure and the number of TNFi exposures on the efficacy of ustekinumab in psoriasis treatment. This retrospective study examined 44 psoriasis patients treated at the Tufts Medical Center Department of Dermatology between January 2008 and July 2014. Patients were selected if they were treated with ustekinumab and had ≥ 1 previous TNFi exposure. The following subgroups were compared: patients with vs without a previous TNFi primary failure, and patients with one vs multiple previous TNFi exposures. The efficacy measure used was the previously validated Simple Measure for Assessing Psoriasis Activity (S-MAPA), which is calculated by the product of the body surface area and physician global assessment. The primary outcome was the percentage improvement S-MAPA from course baseline at week 12 of ustekinumab treatment. Secondary outcomes were the psoriasis clearance, primary failure, and secondary failure rates with ustekinumab treatment. Patients with a previous TNFi primary failure had a significantly lower percentage improvement in S-MAPA score at week 12 of ustekinumab treatment compared with patients without TNFi primary failure (36.2% vs 61.1%, P=.027). Multivariate analysis demonstrated that this relationship was independent of patient demographics and medical comorbidities. Patients with multiple TNFi exposures had a non-statistically significant lower percentage S-MAPA improvement at week 12 (40.5% vs 52.9%, P=.294) of ustekinumab treatment compared with patients with a single TNFi exposure. Among psoriasis patients previously exposed to TNFi, a history of a previous TNFi primary failure predicts a decreased response to ustekinumab independent of patient demographics and medical comorbidities.

  3. Serum albumin level predicts initial intravenous immunoglobulin treatment failure in Kawasaki disease.

    Science.gov (United States)

    Kuo, Ho-Chang; Liang, Chi-Di; Wang, Chih-Lu; Yu, Hong-Ren; Hwang, Kao-Pin; Yang, Kuender D

    2010-10-01

    Kawasaki disease (KD) is a systemic vasculitis primarily affecting children who are initial IVIG treatment. This study was conducted to investigate the risk factors for initial IVIG treatment failure in KD. Children who met KD diagnosis criteria and were admitted for IVIG treatment were retrospectively enrolled for analysis. Patients were divided into IVIG-responsive and IVIG-resistant groups. Initial laboratory data before IVIG treatment were collected for analysis. A total of 131 patients were enrolled during the study period. At 48 h after completion of initial IVIG treatment, 20 patients (15.3%) had an elevated body temperature. Univariate analysis showed that patients who had initial findings of high neutrophil count, abnormal liver function, low serum albumin level (≤2.9 g/dL) and pericardial effusion were at risk for IVIG treatment failure. Multivariate analysis with a logistic regression procedure showed that serum albumin level was considered the independent predicting factor of IVIG resistance in patients with KD (p = 0.006, OR = 40, 95% CI: 52.8-562). There was no significant correlation between age, gender, fever duration before IVIG treatment, haemoglobin level, total leucocyte and platelet counts, C-reactive protein level, or sterile pyuria and initial IVIG treatment failure. The specificity and sensitivity for prediction of IVIG treatment failure in this study were 96% and 34%, respectively. Pre-IVIG treatment serum albumin levels are a useful predictor of IVIG resistance in patients with KD. © 2010 The Author(s)/Journal Compilation © 2010 Foundation Acta Paediatrica.

  4. Baseline Hemodynamics and Response to Contrast Media During Diagnostic Cardiac Catheterization Predict Adverse Events in Heart Failure Patients.

    Science.gov (United States)

    Denardo, Scott J; Vock, David M; Schmalfuss, Carsten M; Young, Gregory D; Tcheng, James E; O'Connor, Christopher M

    2016-07-01

    Contrast media administered during cardiac catheterization can affect hemodynamic variables. However, little is documented about the effects of contrast on hemodynamics in heart failure patients or the prognostic value of baseline and changes in hemodynamics for predicting subsequent adverse events. In this prospective study of 150 heart failure patients, we measured hemodynamics at baseline and after administration of iodixanol or iopamidol contrast. One-year Kaplan-Meier estimates of adverse event-free survival (death, heart failure hospitalization, and rehospitalization) were generated, grouping patients by baseline measures of pulmonary capillary wedge pressure (PCWP) and cardiac index (CI), and by changes in those measures after contrast administration. We used Cox proportional hazards modeling to assess sequentially adding baseline PCWP and change in CI to 5 validated risk models (Seattle Heart Failure Score, ESCAPE [Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness], CHARM [Candesartan in Heart Failure: Assessment of Reduction in Mortality and Morbidity], CORONA [Controlled Rosuvastatin Multinational Trial in Heart Failure], and MAGGIC [Meta-Analysis Global Group in Chronic Heart Failure]). Median contrast volume was 109 mL. Both contrast media caused similarly small but statistically significant changes in most hemodynamic variables. There were 39 adverse events (26.0%). Adverse event rates increased using the composite metric of baseline PCWP and change in CI (Pcontrast correlated with the poorest prognosis. Adding both baseline PCWP and change in CI to the 5 risk models universally improved their predictive value (P≤0.02). In heart failure patients, the administration of contrast causes small but significant changes in hemodynamics. Calculating baseline PCWP with change in CI after contrast predicts adverse events and increases the predictive value of existing models. Patients with elevated baseline PCWP and

  5. Predicting device failure after percutaneous repair of functional mitral regurgitation in advanced heart failure: Implications for patient selection.

    Science.gov (United States)

    Stolfo, Davide; De Luca, Antonio; Morea, Gaetano; Merlo, Marco; Vitrella, Giancarlo; Caiffa, Thomas; Barbati, Giulia; Rakar, Serena; Korcova, Renata; Perkan, Andrea; Pinamonti, Bruno; Pappalardo, Aniello; Berardini, Alessandra; Biagini, Elena; Saia, Francesco; Grigioni, Francesco; Rapezzi, Claudio; Sinagra, Gianfranco

    2018-04-15

    Patients with heart failure (HF) and severe symptomatic functional mitral regurgitation (FMR) may benefit from MitraClip implantation. With increasing numbers of patients being treated the success of procedure becomes a key issue. We sought to investigate the pre-procedural predictors of device failure in patients with advanced HF treated with MitraClip. From April 2012 to November 2016, 76 patients with poor functional class (NYHA class III-IV) and severe left ventricular (LV) remodeling underwent MitraClip implantation at University Hospitals of Trieste and Bologna (Italy). Device failure was assessed according to MVARC criteria. Patients were subsequently followed to additionally assess the patient success after 12months. Mean age was 67±12years, the mean Log-EuroSCORE was 23.4±16.5%, and the mean LV end-diastolic volume index and ejection fraction (EF) were 112±33ml/m 2 and 30.6±8.9%, respectively. At short-term evaluation, device failure was observed in 22 (29%) patients. Univariate predictors of device failure were LVEF, LV and left atrial volumes and anteroposterior mitral annulus diameter. Annulus dimension (OR 1.153, 95% CI 1.002-1.327, p=0.043) and LV end-diastolic volume (OR 1.024, 95% CI 1.000-1.049, p=0.049) were the only variables independently associated with the risk of device failure at the multivariate model. Pre-procedural anteroposterior mitral annulus diameter accurately predicted the risk of device failure after MitraClip in the setting of advanced HF. Its assessment might aid the selection of the best candidates to percutaneous correction of FMR. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Modeling Stress Strain Relationships and Predicting Failure Probabilities For Graphite Core Components

    Energy Technology Data Exchange (ETDEWEB)

    Duffy, Stephen [Cleveland State Univ., Cleveland, OH (United States)

    2013-09-09

    This project will implement inelastic constitutive models that will yield the requisite stress-strain information necessary for graphite component design. Accurate knowledge of stress states (both elastic and inelastic) is required to assess how close a nuclear core component is to failure. Strain states are needed to assess deformations in order to ascertain serviceability issues relating to failure, e.g., whether too much shrinkage has taken place for the core to function properly. Failure probabilities, as opposed to safety factors, are required in order to capture the bariability in failure strength in tensile regimes. The current stress state is used to predict the probability of failure. Stochastic failure models will be developed that can accommodate possible material anisotropy. This work will also model material damage (i.e., degradation of mechanical properties) due to radiation exposure. The team will design tools for components fabricated from nuclear graphite. These tools must readily interact with finite element software--in particular, COMSOL, the software algorithm currently being utilized by the Idaho National Laboratory. For the eleastic response of graphite, the team will adopt anisotropic stress-strain relationships available in COMSO. Data from the literature will be utilized to characterize the appropriate elastic material constants.

  7. Modeling Stress Strain Relationships and Predicting Failure Probabilities For Graphite Core Components

    International Nuclear Information System (INIS)

    Duffy, Stephen

    2013-01-01

    This project will implement inelastic constitutive models that will yield the requisite stress-strain information necessary for graphite component design. Accurate knowledge of stress states (both elastic and inelastic) is required to assess how close a nuclear core component is to failure. Strain states are needed to assess deformations in order to ascertain serviceability issues relating to failure, e.g., whether too much shrinkage has taken place for the core to function properly. Failure probabilities, as opposed to safety factors, are required in order to capture the bariability in failure strength in tensile regimes. The current stress state is used to predict the probability of failure. Stochastic failure models will be developed that can accommodate possible material anisotropy. This work will also model material damage (i.e., degradation of mechanical properties) due to radiation exposure. The team will design tools for components fabricated from nuclear graphite. These tools must readily interact with finite element software--in particular, COMSOL, the software algorithm currently being utilized by the Idaho National Laboratory. For the eleastic response of graphite, the team will adopt anisotropic stress-strain relationships available in COMSO. Data from the literature will be utilized to characterize the appropriate elastic material constants.

  8. Predicting the creep life and failure mode of low-alloy steel weldments

    Energy Technology Data Exchange (ETDEWEB)

    Brear, J M; Middleton, C J; Aplin, P F [ERA Technology Ltd., Leatherhead (United Kingdom)

    1999-12-31

    This presentation reviews and consolidates experience gained through a number of research projects and practical plant assessments in predicting both the life and the likely failure mode and location in low alloy steel weldments. The approach adopted begins with the recognition that the relative strength difference between the microstructural regions is a key factor controlling both life and failure location. Practical methods based on hardness measurement and adaptable to differing weld geometries are presented and evidence for correlations between hardness ratio, damage accumulation and strain development is discussed. Predictor diagrams relating weld life and failure location to the service conditions and the hardness of the individual microstructural constituents are suggested and comments are given on the implications for identifying the circumstances in which Type IV cracking is to be expected. (orig.) 6 refs.

  9. Predicting the creep life and failure mode of low-alloy steel weldments

    Energy Technology Data Exchange (ETDEWEB)

    Brear, J.M.; Middleton, C.J.; Aplin, P.F. [ERA Technology Ltd., Leatherhead (United Kingdom)

    1998-12-31

    This presentation reviews and consolidates experience gained through a number of research projects and practical plant assessments in predicting both the life and the likely failure mode and location in low alloy steel weldments. The approach adopted begins with the recognition that the relative strength difference between the microstructural regions is a key factor controlling both life and failure location. Practical methods based on hardness measurement and adaptable to differing weld geometries are presented and evidence for correlations between hardness ratio, damage accumulation and strain development is discussed. Predictor diagrams relating weld life and failure location to the service conditions and the hardness of the individual microstructural constituents are suggested and comments are given on the implications for identifying the circumstances in which Type IV cracking is to be expected. (orig.) 6 refs.

  10. ON THE PERFORMANCE OF ARTIFICIAL INTELLIGENCEMETHODS FOR FAILURE PREDICTION: EVIDENCE FROMISTANBUL STOCK EXCHANGE

    Directory of Open Access Journals (Sweden)

    Dr Hakan Er

    2014-01-01

    Full Text Available The prediction of business failure is a widely studied subject in financialliterature. Many earlier studies on this topic employed statistical methods such asmultiple discriminant analysis, logit and probit topredict corporate failure usingpast financial data (especially the ratio data. However, there has been a recentsurge in academic interest in the use of artificialintelligence (AI methods topredict financial distress. Numerous studies documented that AI methodsoutperform traditional methods. Majority of these studies used data fromestablished markets, the number of studies on emerging market data is ratherlimited and only a handful of studies employed Turkish data for analysis. Thisstudy aims to contribute to the literature by applying the artificial neural networksto predict deletions from Istanbul Stock Exchange (ISE National 100 Index. Thesample is constructed using the quarterly fundamental data of the companies listedin this index the period between January 2008 and December 2012. We employedNeural Networks (NN, logit and probit to predict deletions from index onequarter before they have occurred. Results show that although the logit providesslightly better in-sample predictions, all of the methods fail to identify deletions inthe out-of-sample periods.

  11. Potential Impact of a Free Online HIV Treatment Response Prediction System for Reducing Virological Failures and Drug Costs after Antiretroviral Therapy Failure in a Resource-Limited Setting

    Directory of Open Access Journals (Sweden)

    Andrew D. Revell

    2013-01-01

    Full Text Available Objective. Antiretroviral drug selection in resource-limited settings is often dictated by strict protocols as part of a public health strategy. The objective of this retrospective study was to examine if the HIV-TRePS online treatment prediction tool could help reduce treatment failure and drug costs in such settings. Methods. The HIV-TRePS computational models were used to predict the probability of response to therapy for 206 cases of treatment change following failure in India. The models were used to identify alternative locally available 3-drug regimens, which were predicted to be effective. The costs of these regimens were compared to those actually used in the clinic. Results. The models predicted the responses to treatment of the cases with an accuracy of 0.64. The models identified alternative drug regimens that were predicted to result in improved virological response and lower costs than those used in the clinic in 85% of the cases. The average annual cost saving was $364 USD per year (41%. Conclusions. Computational models that do not require a genotype can predict and potentially avoid treatment failure and may reduce therapy costs. The use of such a system to guide therapeutic decision-making could confer health economic benefits in resource-limited settings.

  12. PROBABILISTIC PREDICTION OF BANK FAILURES WITH FINANCIAL RATIOS: AN EMPIRICAL STUDY ON TURKISH BANKS

    Directory of Open Access Journals (Sweden)

    Gamze Özel

    2014-02-01

    Full Text Available Banking risk management has become more important during the last 20 years in response to a worldwide increase in the number of bank failures. Turkey has experienced a series of economic and financial crisis since the declaration of Republic and banking system has the most affected sector from the results of these crises. This paper examines some bank failure prediction models using financial ratios. Survival, ordinary and conditional logistic regression models are employed in order to develop these prediction models. The empirical results indicate that the bank is more likely to go bankrupt if it is unprofitable, small, highly leveraged, and has liquidity problems and less financial flexibility to invest itself. 

  13. Characterization of acute-on-chronic liver failure and prediction of mortality in Asian patients with active alcoholism.

    Science.gov (United States)

    Kim, Hwi Young; Chang, Young; Park, Jae Yong; Ahn, Hongkeun; Cho, Hyeki; Han, Seung Jun; Oh, Sohee; Kim, Donghee; Jung, Yong Jin; Kim, Byeong Gwan; Lee, Kook Lae; Kim, Won

    2016-02-01

    Alcoholic liver diseases often evolve to acute-on-chronic liver failure (ACLF), which increases the risk of (multi-)organ failure and death. We investigated the development and characteristics of alcohol-related ACLF and evaluated prognostic scores for prediction of mortality in Asian patients with active alcoholism. A total of 205 patients who were hospitalized with severe alcoholic liver disease were included in this retrospective cohort study, after excluding those with serious cardiovascular diseases, malignancy, or co-existing viral hepatitis. The Chronic Liver Failure (CLIF) Consortium Organ Failure score was used in the diagnosis and grading of ACLF, and the CLIF Consortium ACLF score (CLIF-C ACLFs) was used to predict mortality. Patients with ACLF had higher Maddrey discriminant function, model for end-stage liver disease (MELD), and MELD-sodium scores than those without ACLF. Infections were more frequently documented in patients with ACLF (33.3% vs 53.0%; P = 0.004). Predictive factors for ACLF development were systemic inflammatory response syndrome (odds ratio [OR], 2.239; P alcohol-related ACLF in Asian patients with active alcoholism. The CLIF-C ACLFs may be more useful for predicting mortality in ACLF cases than liver-specific scoring systems. © 2015 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  14. Definition of containment failure

    International Nuclear Information System (INIS)

    Cybulskis, P.

    1982-01-01

    Core meltdown accidents of the types considered in probabilistic risk assessments (PRA's) have been predicted to lead to pressures that will challenge the integrity of containment structures. Review of a number of PRA's indicates considerable variation in the predicted probability of containment failure as a function of pressure. Since the results of PRA's are sensitive to the prediction of the occurrence and the timing of containment failure, better understanding of realistic containment capabilities and a more consistent approach to the definition of containment failure pressures are required. Additionally, since the size and location of the failure can also significantly influence the prediction of reactor accident risk, further understanding of likely failure modes is required. The thresholds and modes of containment failure may not be independent

  15. Prediction of failure of highly irradiated Zircaloy clad tubes under reactivity initiated accidents

    International Nuclear Information System (INIS)

    Jernkvist, L.O.

    2003-01-01

    This paper deals with failure of irradiated Zircaloy tubes under the heat-up stage of a reactivity initiated accident (RIA). More precisely, by use of a model for plastic strain localization and necking failure, we theoretically analyse the effects of local surface defects on clad ductility and survivability under RIA. The results show that even very shallow surface defects, e.g. arising from a non-uniform or partially spilled oxide layer, have a strong limiting effect on clad ductility. Moreover, in presence of surface defects, the ability of the clad tube to expand radially without necking failure is found to be extremely sensitive to the stress biaxiality ratio σ zz /σ θθ , which is here assumed to be in the range from 0 to 1. The results of our analysis are compared with clad ductility data available in literature, and their consequences for clad failure prediction under RIA are discussed. In particular, the results raise serious concerns regarding the applicability of failure criteria, which are based on clad strain energy density. These criteria do not capture the observed sensitivity to stress biaxiality on clad failure propensity. (author)

  16. Prediction of failure enthalpy and reliability of irradiated fuel rod under reactivity-initiated accidents by means of statistical approach

    International Nuclear Information System (INIS)

    Nam, Cheol; Choi, Byeong Kwon; Jeong, Yong Hwan; Jung, Youn Ho

    2001-01-01

    During the last decade, the failure behavior of high-burnup fuel rods under RIA has been an extensive concern since observations of fuel rod failures at low enthalpy. Of great importance is placed on failure prediction of fuel rod in the point of licensing criteria and safety in extending burnup achievement. To address the issue, a statistics-based methodology is introduced to predict failure probability of irradiated fuel rods. Based on RIA simulation results in literature, a failure enthalpy correlation for irradiated fuel rod is constructed as a function of oxide thickness, fuel burnup, and pulse width. From the failure enthalpy correlation, a single damage parameter, equivalent enthalpy, is defined to reflect the effects of the three primary factors as well as peak fuel enthalpy. Moreover, the failure distribution function with equivalent enthalpy is derived, applying a two-parameter Weibull statistical model. Using these equations, the sensitivity analysis is carried out to estimate the effects of burnup, corrosion, peak fuel enthalpy, pulse width and cladding materials used

  17. A Systematic Review on Prognostic Indicators of Acute Liver Failure and Their Predictive Value for Poor Outcome

    NARCIS (Netherlands)

    Wlodzimirow, Kama A.; Eslami, Saeid; Abu-Hanna, Ameen; Nieuwoudt, Martin; Chamuleau, Robert A. F. M.

    2014-01-01

    This review provides a large amount of information, including the extensive list of worldwide used indicators to predict outcome in patients with acute liver failure. There is large heterogeneity in prognostic indicators of acute liver failure, methods of measurement, complexity of calculation and

  18. Prediction of the time-dependent failure rate for normally operating components taking into account the operational history

    International Nuclear Information System (INIS)

    Vrbanic, I.; Simic, Z.; Sljivac, D.

    2008-01-01

    The prediction of the time-dependent failure rate has been studied, taking into account the operational history of a component used in applications such as system modeling in a probabilistic safety analysis in order to evaluate the impact of equipment aging and maintenance strategies on the risk measures considered. We have selected a time-dependent model for the failure rate which is based on the Weibull distribution and the principles of proportional age reduction by equipment overhauls. Estimation of the parameters that determine the failure rate is considered, including the definition of the operational history model and likelihood function for the Bayesian analysis of parameters for normally operating repairable components. The operational history is provided as a time axis with defined times of overhauls and failures. An example for demonstration is described with prediction of the future behavior for seven different operational histories. (orig.)

  19. Failure Prediction for Autonomous Driving

    OpenAIRE

    Hecker, Simon; Dai, Dengxin; Van Gool, Luc

    2018-01-01

    The primary focus of autonomous driving research is to improve driving accuracy. While great progress has been made, state-of-the-art algorithms still fail at times. Such failures may have catastrophic consequences. It therefore is important that automated cars foresee problems ahead as early as possible. This is also of paramount importance if the driver will be asked to take over. We conjecture that failures do not occur randomly. For instance, driving models may fail more likely at places ...

  20. Probabilistic Modeling of Updating Epistemic Uncertainty In Pile Capacity Prediction With a Single Failure Test Result

    Directory of Open Access Journals (Sweden)

    Indra Djati Sidi

    2017-12-01

    Full Text Available The model error N has been introduced to denote the discrepancy between measured and predicted capacity of pile foundation. This model error is recognized as epistemic uncertainty in pile capacity prediction. The statistics of N have been evaluated based on data gathered from various sites and may be considered only as a eneral-error trend in capacity prediction, providing crude estimates of the model error in the absence of more specific data from the site. The results of even a single load test to failure, should provide direct evidence of the pile capacity at a given site. Bayes theorem has been used as a rational basis for combining new data with previous data to revise assessment of uncertainty and reliability. This study is devoted to the development of procedures for updating model error (N, and subsequently the predicted pile capacity with a results of single failure test.

  1. Acute Systolic Heart Failure Associated with Complement-Mediated Hemolytic Uremic Syndrome

    Directory of Open Access Journals (Sweden)

    John L. Vaughn

    2015-01-01

    Full Text Available Complement-mediated hemolytic uremic syndrome (otherwise known as atypical HUS is a rare disorder of uncontrolled complement activation that may be associated with heart failure. We report the case of a 49-year-old female with no history of heart disease who presented with microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. Given her normal ADAMSTS13 activity, evidence of increased complement activation, and renal biopsy showing evidence of thrombotic microangiopathy, she was diagnosed with complement-mediated HUS. She subsequently developed acute hypoxemic respiratory failure secondary to pulmonary edema requiring intubation and mechanical ventilation. A transthoracic echocardiogram showed evidence of a Takotsubo cardiomyopathy with an estimated left ventricular ejection fraction of 20%, though ischemic cardiomyopathy could not be ruled out. Treatment was initiated with eculizumab. After several failed attempts at extubation, she eventually underwent tracheotomy. She also required hemodialysis to improve her uremia and hypervolemia. After seven weeks of hospitalization and five doses of eculizumab, her renal function and respiratory status improved, and she was discharged in stable condition on room air and independent of hemodialysis. Our case illustrates a rare association between acute systolic heart failure and complement-mediated HUS and highlights the potential of eculizumab in stabilizing even the most critically-ill patients with complement-mediated disease.

  2. Accuracy of circulating histones in predicting persistent organ failure and mortality in patients with acute pancreatitis.

    Science.gov (United States)

    Liu, T; Huang, W; Szatmary, P; Abrams, S T; Alhamdi, Y; Lin, Z; Greenhalf, W; Wang, G; Sutton, R; Toh, C H

    2017-08-01

    Early prediction of acute pancreatitis severity remains a challenge. Circulating levels of histones are raised early in mouse models and correlate with disease severity. It was hypothesized that circulating histones predict persistent organ failure in patients with acute pancreatitis. Consecutive patients with acute pancreatitis fulfilling inclusion criteria admitted to Royal Liverpool University Hospital were enrolled prospectively between June 2010 and March 2014. Blood samples were obtained within 48 h of abdominal pain onset and relevant clinical data during the hospital stay were collected. Healthy volunteers were enrolled as controls. The primary endpoint was occurrence of persistent organ failure. The predictive values of circulating histones, clinical scores and other biomarkers were determined. Among 236 patients with acute pancreatitis, there were 156 (66·1 per cent), 57 (24·2 per cent) and 23 (9·7 per cent) with mild, moderate and severe disease respectively, according to the revised Atlanta classification. Forty-seven healthy volunteers were included. The area under the receiver operating characteristic (ROC) curve (AUC) for circulating histones in predicting persistent organ failure and mortality was 0·92 (95 per cent c.i. 0·85 to 0·99) and 0·96 (0·92 to 1·00) respectively; histones were at least as accurate as clinical scores or biochemical markers. For infected pancreatic necrosis and/or sepsis, the AUC was 0·78 (0·62 to 0·94). Histones did not predict or correlate with local pancreatic complications, but correlated negatively with leucocyte cell viability (r = -0·511, P = 0·001). Quantitative assessment of circulating histones in plasma within 48 h of abdominal pain onset can predict persistent organ failure and mortality in patients with acute pancreatitis. Early death of immune cells may contribute to raised circulating histone levels in acute pancreatitis. © 2017 The Authors. BJS published by John Wiley & Sons Ltd on behalf of BJS

  3. [Successful weaning and extubation in the premature newborn using neurally adjusted ventilatory assist].

    Science.gov (United States)

    García-Muñoz Rodrigo, F; Rivero Rodríguez, S; Florido Rodríguez, A; Martín Cruz, F G; Díaz Pulido, R

    2015-01-01

    Invasive and non-invasive ventilation of the preterm newborn may be associated with local and systemic complications due to mechanical trauma to lung tissues and their inflammatory response. A key objective of any type of mechanical ventilation, therefore, is to reduce its duration and the side effects related to it. Neurally Adjusted Ventilatory Assist (NAVA) may improve synchronization between patient and ventilator and optimize the gas volume delivered to the lungs, according to the patient needs, eventually reducing volu- and biotrauma. Two preterm babies with severe respiratory distress syndrome are presented, who were successfully weaned and extubated with the help of this ventilatory system. Further studies are needed to assess whether short-term benefits are reflected in better outcomes in the long run. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  4. Value of Serial Heart Rate Variability Measurement for Prediction of Appropriate ICD Discharge in Patients with Heart Failure

    NARCIS (Netherlands)

    ten Sande, Judith N.; Damman, Peter; Tijssen, Jan G. P.; de Groot, Joris R.; Knops, Reinoud E.; Wilde, Arthur A. M.; van Dessel, Pascal F. H. M.

    2014-01-01

    HRV and Appropriate ICD Shock in Heart Failure Introduction Decreased heart rate variability (HRV) is associated with adverse outcomes in patients with heart failure. Our objective was to examine whether decreased HRV predicts appropriate implantable cardioverter defibrillator (ICD) shocks. Methods

  5. TNF Receptor 1/2 Predict Heart Failure Risk in Type 2 Diabetes Mellitus Patients.

    Science.gov (United States)

    Ping, Zhang; Aiqun, Ma; Jiwu, Li; Liang, Shao

    2017-04-06

    Inflammation plays an important role in heart failure and diabetes mellitus. Traditional serum markers have limited predictive value in heart failure and diabetes. TNFR1 and TNFR2 (TNFR1/2) have been proven to be strongly associated with heart failure and diabetes complications. This study aimed to assess the association of sTNFR1 and sTNFR2 levels and incidental HF risk in diabetes patients.We detected the mRNA, protein, and serum expression of TNFR1/2, their downstream signaling pathway protein NF-kB, and JNK expression and some traditional serum inflammatory markers in a heart failure group without diabetes mellitus or abnormal glucose tolerance (n = 84), a diabetes mellitus group without heart failure (n = 86), and a heart failure with diabetes mellitus group (n = 86).TNFR1/2 were significantly higher in patients with heart failure and diabetes mellitus based on mRNA expression to protein expression and serum expression. However, there were no differences in mRNA, protein, and serum levels of TNFR1/2 between the HF group and DM group. Furthermore, there were no differences between the groups in some traditional serum inflammatory markers.This study demonstrated higher expressions of TNFR, NF-kB, and JNK in patients with heart failure and diabetes mellitus. Compared with traditional serum markers, TNFR1 and TNFR2 are associated with heart failure risk in type 2 diabetes mellitus patients.

  6. GRACE score predicts heart failure admission following acute coronary syndrome.

    Science.gov (United States)

    McAllister, David A; Halbesma, Nynke; Carruthers, Kathryn; Denvir, Martin; Fox, Keith A

    2015-04-01

    Congestive heart failure (CHF) is a common and preventable complication of acute coronary syndrome (ACS). Nevertheless, ACS risk scores have not been shown to predict CHF risk. We investigated whether the at-discharge Global Registry of Acute Coronary Events (GRACE) score predicts heart failure admission following ACS. Five-year mortality and hospitalization data were obtained for patients admitted with ACS from June 1999 to September 2009 to a single centre of the GRACE registry. CHF was defined as any admission assigned WHO International Classification of Diseases 10 diagnostic code I50. The hazard ratio (HR) for CHF according to GRACE score was estimated in Cox models adjusting for age, gender and the presence of CHF on index admission. Among 1,956 patients, CHF was recorded on index admission in 141 patients (7%), and 243 (12%) were admitted with CHF over 3.8 median years of follow-up. Compared to the lowest quintile, patients in the highest GRACE score quintile had more CHF admissions (116 vs 17) and a shorter time to first admission (1.2 vs 2.0 years, HR 9.87, 95% CI 5.93-16.43). Per standard deviation increment in GRACE score, the instantaneous risk was more than two-fold higher (HR 2.28; 95% CI 2.02-2.57), including after adjustment for CHF on index admission, age and gender (HR 2.49; 95% CI 2.06-3.02). The C-statistic for CHF admission at 1-year was 0.74 (95% CI 0.70-0.79). The GRACE score predicts CHF admission, and may therefore be used to target ACS patients at high risk of CHF with clinical monitoring and therapies. © The European Society of Cardiology 2014.

  7. Predicting Factors of INSURE Failure in Low Birth Weight Neonates with RDS; A Logistic Regression Model

    Directory of Open Access Journals (Sweden)

    Bita Najafian

    2015-02-01

    Full Text Available Background:Respiratory Distress syndrome is the most common respiratory disease in premature neonate and the most important cause of death among them. We aimed to investigate factors to predict successful or failure of INSURE method as a therapeutic method of RDS.Methods:In a cohort study,45 neonates with diagnosed RDS and birth weight lower than 1500g were included and they underwent INSURE followed by NCPAP(Nasal Continuous Positive Airway Pressure. The patients were divided into failure or successful groups and factors which can predict success of INSURE were investigated by logistic regression in SPSS 16th version.Results:29 and16 neonates were observed in successful and failure groups, respectively. Birth weight was the only variable with significant difference between two groups (P=0.002. Finally logistic regression test showed that birth weight is only predicting factor for success (P: 0.001, EXP[β]: 0.009, CI [95%]: 1.003-0.014 and mortality (P: 0.029, EXP[β]: 0.993, CI [95%]: 0.987-0.999 of neonates treated with INSURE method.Conclusion:Predicting factors which affect on success rate of INSURE can be useful for treating and reducing charge of neonate with RDS and the birth weight is one of the effective factor on INSURE Success in this study.

  8. Predicting Factors of INSURE Failure in Low Birth Weight Neonates with RDS; A Logistic Regression Model

    Directory of Open Access Journals (Sweden)

    Bita Najafian

    2015-02-01

    Full Text Available Background:Respiratory Distress syndrome is the most common respiratory disease in premature neonate and the most important cause of death among them. We aimed to investigate factors to predict successful or failure of INSURE method as a therapeutic method of RDS. Methods:In a cohort study,45 neonates with diagnosed RDS and birth weight lower than 1500g were included and they underwent INSURE followed by NCPAP(Nasal Continuous Positive Airway Pressure. The patients were divided into failure or successful groups and factors which can predict success of INSURE were investigated by logistic regression in SPSS 16th version. Results:29 and16 neonates were observed in successful and failure groups, respectively. Birth weight was the only variable with significant difference between two groups (P=0.002. Finally logistic regression test showed that birth weight is only predicting factor for success (P: 0.001, EXP[β]: 0.009, CI [95%]: 1.003-0.014 and mortality (P: 0.029, EXP[β]: 0.993, CI [95%]: 0.987-0.999 of neonates treated with INSURE method. Conclusion:Predicting factors which affect on success rate of INSURE can be useful for treating and reducing charge of neonate with RDS and the birth weight is one of the effective factor on INSURE Success in this study.

  9. Development and validation of a dynamic outcome prediction model for paracetamol-induced acute liver failure

    DEFF Research Database (Denmark)

    Bernal, William; Wang, Yanzhong; Maggs, James

    2016-01-01

    : The models developed here show very good discrimination and calibration, confirmed in independent datasets, and suggest that many patients undergoing transplantation based on existing criteria might have survived with medical management alone. The role and indications for emergency liver transplantation......BACKGROUND: Early, accurate prediction of survival is central to management of patients with paracetamol-induced acute liver failure to identify those needing emergency liver transplantation. Current prognostic tools are confounded by recent improvements in outcome independent of emergency liver...... transplantation, and constrained by static binary outcome prediction. We aimed to develop a simple prognostic tool to reflect current outcomes and generate a dynamic updated estimation of risk of death. METHODS: Patients with paracetamol-induced acute liver failure managed at intensive care units in the UK...

  10. Rational temporal predictions can underlie apparent failures to delay gratification

    Science.gov (United States)

    McGuire, Joseph T.; Kable, Joseph W.

    2013-01-01

    An important category of seemingly maladaptive decisions involves failure to postpone gratification. A person pursuing a desirable long-run outcome may abandon it in favor of a short-run alternative that has been available all along. Here we present a theoretical framework in which this seemingly irrational behavior emerges from stable preferences and veridical judgments. Our account recognizes that decision makers generally face uncertainty regarding the time at which future outcomes will materialize. When timing is uncertain, the value of persistence depends crucially on the nature of a decision-maker’s prior temporal beliefs. Certain forms of temporal beliefs imply that a delay’s predicted remaining length increases as a function of time already waited. In this type of situation, the rational, utility-maximizing strategy is to persist for a limited amount of time and then give up. We show empirically that people’s explicit predictions of remaining delay lengths indeed increase as a function of elapsed time in several relevant domains, implying that temporal judgments offer a rational basis for limiting persistence. We then develop our framework into a simple working model and show how it accounts for individual differences in a laboratory task (the well-known “marshmallow test”). We conclude that delay-of-gratification failure, generally viewed as a manifestation of limited self-control capacity, can instead arise as an adaptive response to the perceived statistics of one’s environment. PMID:23458085

  11. Prediction of Composite Pressure Vessel Failure Location using Fiber Bragg Grating Sensors

    Science.gov (United States)

    Kreger, Steven T.; Taylor, F. Tad; Ortyl, Nicholas E.; Grant, Joseph

    2006-01-01

    Ten composite pressure vessels were instrumented with fiber Bragg grating sensors in order to assess the strain levels of the vessel under various loading conditions. This paper and presentation will discuss the testing methodology, the test results, compare the testing results to the analytical model, and present a possible methodology for predicting the failure location and strain level of composite pressure vessels.

  12. Health Visitor's Role in Prediction of Early Childhood Injuries and Failure to Thrive.

    Science.gov (United States)

    Dean, Janet G.; And Others

    1978-01-01

    Discusses the role of the health visitor in the prediction of early childhood injuries, abuse, and failure to thrive--based on a three-year study of the relationship between early maternal attitudes and subsequent child health. Journal availability: Pergamon Press Ltd., Headington Hill Hall, Oxford, OX3 OBW England. (DLS)

  13. Factors predicting the outcome of acute renal failure in pregnancy

    International Nuclear Information System (INIS)

    Khana, N.; Akhtar, F.

    2010-01-01

    To determine the factors predicting renal outcome in patients developing acute renal failure in pregnancy. Study Design: Descriptive cohort study. Place and Duration of Study: Study was conducted at Nephrology Unit of Sindh Institute of Urology and Transplantation, Karachi, from October 2006 to March 2007. Methodology: Patients with acute renal failure due to complications of pregnancy, with normal size of both the kidneys on ultrasound were enrolled, and followed for a period of 60 days or until recovery of renal function. Patient's age and parity, presence of antenatal care, type of complication of pregnancy, foetal outcome and duration of oliguria were compared between patients who remained dialysis dependent and those who recovered renal function. Chi-square/Fisher's exact test and student's t-test, were used for determining the association of categorical and continuous variables with dialysis dependency. Results: The mean age was 29 +- 6 years. Most patients came from rural areas of interior Sindh. Sixty eight percent did not have antenatal checkups. Antepartum haemorrhage (p=0.002) and prolonged duration of oliguria (35 +- 15.7 days, p= < 0.001) were associated with dialysis dependency, which was observed in 50% of the study group. Conclusion: Ante-partum haemorrhage and prolonged oliguria were strong predictors of irreversible renal failure. This highlights the need for early recognition and referral, and the importance of trained birth attendants and antenatal care. (author)

  14. Hope of Success and Fear of Failure Predicting Academic Procrastination Students Who Working on a Thesis

    Directory of Open Access Journals (Sweden)

    Sari Zakiah Akmal

    2017-08-01

    Full Text Available Students, who are working on the thesis, have some difficulties caused by internal and external factors. Those problems can disrupt the completion of their thesis, such as the tendency to do academic procrastination. Increasing achievement motivation can reduce academic procrastination. This study aims to look at the role of achievement motivation (hope of success and fear of failure in predicting academic procrastination. The study used a quantitative approach by distributing academic procrastination and achievement motivation questionnaires. The study involved 182 students who were working on a thesis as samples, which were obtained by using accidental sampling technique. Data were analyzed using multiple regressions. It showed that the hope of success and fear of failure have a significant role in predicting academic procrastination (R2 = 13.8%, F = 14,356, p <0.05. The hope of success can decrease academic procrastination, while fear of failure can improve it. Thus, interventions to reduce academic procrastination can be delivered by increasing students hope of success.

  15. Prediction Model of Machining Failure Trend Based on Large Data Analysis

    Science.gov (United States)

    Li, Jirong

    2017-12-01

    The mechanical processing has high complexity, strong coupling, a lot of control factors in the machining process, it is prone to failure, in order to improve the accuracy of fault detection of large mechanical equipment, research on fault trend prediction requires machining, machining fault trend prediction model based on fault data. The characteristics of data processing using genetic algorithm K mean clustering for machining, machining feature extraction which reflects the correlation dimension of fault, spectrum characteristics analysis of abnormal vibration of complex mechanical parts processing process, the extraction method of the abnormal vibration of complex mechanical parts processing process of multi-component spectral decomposition and empirical mode decomposition Hilbert based on feature extraction and the decomposition results, in order to establish the intelligent expert system for the data base, combined with large data analysis method to realize the machining of the Fault trend prediction. The simulation results show that this method of fault trend prediction of mechanical machining accuracy is better, the fault in the mechanical process accurate judgment ability, it has good application value analysis and fault diagnosis in the machining process.

  16. A model to predict failure of irradiated U–Mo dispersion fuel

    Energy Technology Data Exchange (ETDEWEB)

    Burkes, Douglas E., E-mail: Douglas.Burkes@pnnl.gov; Senor, David J.; Casella, Andrew M.

    2016-12-15

    Highlights: • Simple model to predict failure of dispersion fuel meat designs. • Evaluated as a function of fabrication parameters and irradiation conditions. • Predictions compare well with experimental measurements of miniature fuel plates. • Interaction layer formation reduces matrix strength and increases temperature. • Si additions to the matrix appear effective only at moderate heat flux and burnup. - Abstract: Numerous global programs are focused on the continued development of existing and new research and test reactor fuels to achieve maximum attainable uranium loadings to support the conversion of a number of the world’s remaining high-enriched uranium fueled reactors to low-enriched uranium fuel. Some of these programs are focused on development and qualification of a fuel design that consists of a uranium–molybdenum (U–Mo) alloy dispersed in an aluminum matrix as one option for reactor conversion. The current paper extends a failure model originally developed for UO{sub 2}-stainless steel dispersion fuels and uses currently available thermal–mechanical property information for the materials of interest in the currently proposed design. A number of fabrication and irradiation parameters were investigated to understand the conditions at which failure of the matrix, classified as onset of pore formation in the matrix, might occur. The results compared well with experimental observations published as part of the Reduced Enrichment for Research and Test Reactors (RERTR)-6 and -7 mini-plate experiments. Fission rate, a function of the {sup 235}U enrichment, appeared to be the most influential parameter in premature failure, mainly as a result of increased interaction layer formation and operational temperature, which coincidentally decreased the strength of the matrix and caused more rapid fission gas production and recoil into the surrounding matrix material. Addition of silicon to the matrix appeared effective at reducing the rate of

  17. The prediction of cyclic proximal humerus fracture fixation failure by various bone density measures.

    Science.gov (United States)

    Varga, Peter; Grünwald, Leonard; Windolf, Markus

    2018-02-22

    Fixation of osteoporotic proximal humerus fractures has remained challenging, but may be improved by careful pre-operative planning. The aim of this study was to investigate how well the failure of locking plate fixation of osteoporotic proximal humerus fractures can be predicted by bone density measures assessed with currently available clinical imaging (realistic case) and a higher resolution and quality modality (theoretical best-case). Various density measures were correlated to experimentally assessed number of cycles to construct failure of plated unstable low-density proximal humerus fractures (N = 18). The influence of density evaluation technique was investigated by comparing local (peri-implant) versus global evaluation regions; HR-pQCT-based versus clinical QCT-based image data; ipsilateral versus contralateral side; and bone mineral content (BMC) versus bone mineral density (BMD). All investigated density measures were significantly correlated with the experimental cycles to failure. The best performing clinically feasible parameter was the QCT-based BMC of the contralateral articular cap region, providing significantly better correlation (R 2  = 0.53) compared to a previously proposed clinical density measure (R 2  = 0.30). BMC had consistently, but not significantly stronger correlations with failure than BMD. The overall best results were obtained with the ipsilateral HR-pQCT-based local BMC (R 2  = 0.74) that may be used for implant optimization. Strong correlations were found between the corresponding density measures of the two CT image sources, as well as between the two sides. Future studies should investigate if BMC of the contralateral articular cap region could provide improved prediction of clinical fixation failure compared to previously proposed measures. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  18. Extreme events and predictability of catastrophic failure in composite materials and in the Earth

    Science.gov (United States)

    Main, I.; Naylor, M.

    2012-05-01

    Despite all attempts to isolate and predict extreme earthquakes, these nearly always occur without obvious warning in real time: fully deterministic earthquake prediction is very much a `black swan'. On the other hand engineering-scale samples of rocks and other composite materials often show clear precursors to dynamic failure under controlled conditions in the laboratory, and successful evacuations have occurred before several volcanic eruptions. This may be because extreme earthquakes are not statistically special, being an emergent property of the process of dynamic rupture. Nevertheless, probabilistic forecasting of event rate above a given size, based on the tendency of earthquakes to cluster in space and time, can have significant skill compared to say random failure, even in real-time mode. We address several questions in this debate, using examples from the Earth (earthquakes, volcanoes) and the laboratory, including the following. How can we identify `characteristic' events, i.e. beyond the power law, in model selection (do dragon-kings exist)? How do we discriminate quantitatively between stationary and non-stationary hazard models (is a dragon likely to come soon)? Does the system size (the size of the dragon's domain) matter? Are there localising signals of imminent catastrophic failure we may not be able to access (is the dragon effectively invisible on approach)? We focus on the effect of sampling effects and statistical uncertainty in the identification of extreme events and their predictability, and highlight the strong influence of scaling in space and time as an outstanding issue to be addressed by quantitative studies, experimentation and models.

  19. Pitfalls and Precautions When Using Predicted Failure Data for Quantitative Analysis of Safety Risk for Human Rated Launch Vehicles

    Science.gov (United States)

    Hatfield, Glen S.; Hark, Frank; Stott, James

    2016-01-01

    Launch vehicle reliability analysis is largely dependent upon using predicted failure rates from data sources such as MIL-HDBK-217F. Reliability prediction methodologies based on component data do not take into account system integration risks such as those attributable to manufacturing and assembly. These sources often dominate component level risk. While consequence of failure is often understood, using predicted values in a risk model to estimate the probability of occurrence may underestimate the actual risk. Managers and decision makers use the probability of occurrence to influence the determination whether to accept the risk or require a design modification. The actual risk threshold for acceptance may not be fully understood due to the absence of system level test data or operational data. This paper will establish a method and approach to identify the pitfalls and precautions of accepting risk based solely upon predicted failure data. This approach will provide a set of guidelines that may be useful to arrive at a more realistic quantification of risk prior to acceptance by a program.

  20. SU-F-R-46: Predicting Distant Failure in Lung SBRT Using Multi-Objective Radiomics Model

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Z; Folkert, M; Iyengar, P; Zhang, Y; Wang, J [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: To predict distant failure in lung stereotactic body radiation therapy (SBRT) in early stage non-small cell lung cancer (NSCLC) by using a new multi-objective radiomics model. Methods: Currently, most available radiomics models use the overall accuracy as the objective function. However, due to data imbalance, a single object may not reflect the performance of a predictive model. Therefore, we developed a multi-objective radiomics model which considers both sensitivity and specificity as the objective functions simultaneously. The new model is used to predict distant failure in lung SBRT using 52 patients treated at our institute. Quantitative imaging features of PET and CT as well as clinical parameters are utilized to build the predictive model. Image features include intensity features (9), textural features (12) and geometric features (8). Clinical parameters for each patient include demographic parameters (4), tumor characteristics (8), treatment faction schemes (4) and pretreatment medicines (6). The modelling procedure consists of two steps: extracting features from segmented tumors in PET and CT; and selecting features and training model parameters based on multi-objective. Support Vector Machine (SVM) is used as the predictive model, while a nondominated sorting-based multi-objective evolutionary computation algorithm II (NSGA-II) is used for solving the multi-objective optimization. Results: The accuracy for PET, clinical, CT, PET+clinical, PET+CT, CT+clinical, PET+CT+clinical are 71.15%, 84.62%, 84.62%, 85.54%, 82.69%, 84.62%, 86.54%, respectively. The sensitivities for the above seven combinations are 41.76%, 58.33%, 50.00%, 50.00%, 41.67%, 41.67%, 58.33%, while the specificities are 80.00%, 92.50%, 90.00%, 97.50%, 92.50%, 97.50%, 97.50%. Conclusion: A new multi-objective radiomics model for predicting distant failure in NSCLC treated with SBRT was developed. The experimental results show that the best performance can be obtained by combining

  1. Perioperative care following complex laryngotracheal reconstruction in infants and children

    Directory of Open Access Journals (Sweden)

    Gupta Punkaj

    2010-01-01

    Full Text Available Laryngotracheal reconstruction (LTR involves surgical correction of a stenotic airway with cartilage interpositional grafting, followed by either placement of a tracheostomy and an intraluminal stent (two-stage LTR or placement of an endotracheal tube with postoperative sedation and mechanical ventilation for an extended period of time (single-stage LTR. With single-stage repair, there may be several perioperative challenges including the provision of adequate sedation, avoidance of the development of tolerance to sedative and analgesia agents, the need to use neuromuscular blocking agents, the maintenance of adequate pulmonary toilet to avoid perioperative nosocomial infections, and optimization of postoperative respiratory function to facilitate successful tracheal extubation. We review the perioperative management of these patients, discuss the challenges during the postoperative period, and propose recommendations for the prevention of reversible causes of extubation failure in this article. Optimization to ensure a timely tracheal extubation and successful weaning of mechanical ventilator, remains the primary key to success in these surgeries as extubation failure or the need for prolonged postoperative mechanical ventilation can lead to failure of the graft site, the need for prolonged Pediatric Intensive Care Unit care, and in some cases, the need for a tracheostomy to maintain an adequate airway.

  2. Stochastic failure modelling of unidirectional composite ply failure

    International Nuclear Information System (INIS)

    Whiteside, M.B.; Pinho, S.T.; Robinson, P.

    2012-01-01

    Stochastic failure envelopes are generated through parallelised Monte Carlo Simulation of a physically based failure criteria for unidirectional carbon fibre/epoxy matrix composite plies. Two examples are presented to demonstrate the consequence on failure prediction of both statistical interaction of failure modes and uncertainty in global misalignment. Global variance-based Sobol sensitivity indices are computed to decompose the observed variance within the stochastic failure envelopes into contributions from physical input parameters. The paper highlights a selection of the potential advantages stochastic methodologies offer over the traditional deterministic approach.

  3. Diagnostic prediction of renal failure from blood serum analysis by FTIR spectrometry and chemometrics

    Science.gov (United States)

    Khanmohammadi, Mohammdreza; Ghasemi, Keyvan; Garmarudi, Amir Bagheri; Ramin, Mehdi

    2015-02-01

    A new diagnostic approach based on Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectrometry and classification algorithm has been introduced which provides a rapid, reliable, and easy way to perform blood test for the diagnosis of renal failure. Blood serum samples from 35 renal failure patients and 40 healthy persons were analyzed by ATR-FTIR spectrometry. The resulting data was processed by Quadratic Discriminant Analysis (QDA) and QDA combined with simple filtered method. Spectroscopic studies were performed in 900-2000 cm-1 spectral region with 3.85 cm-1 data space. Results showed 93.33% and 100% of accuracy for QDA and filter-QDA models, respectively. In the first step, 30 samples were applied to construct the model. In order to modify the capability of QDA in prediction of test samples, filter-based feature selection methods were applied. It was found that the filtered spectra coupled with QDA could correctly predict the test samples in most of the cases.

  4. Serum Procalcitonin and Peripheral Venous Lactate for Predicting Dengue Shock and/or Organ Failure: A Prospective Observational Study.

    Directory of Open Access Journals (Sweden)

    Vipa Thanachartwet

    2016-08-01

    Full Text Available Currently, there are no biomarkers that can predict the incidence of dengue shock and/or organ failure, although the early identification of risk factors is important in determining appropriate management to reduce mortality. Therefore, we sought to determine the factors associated with dengue shock and/or organ failure and to evaluate the prognostic value of serum procalcitonin (PCT and peripheral venous lactate (PVL levels as biomarkers of dengue shock and/or organ failure.A prospective observational study was conducted among adults hospitalized for confirmed viral dengue infection at the Hospital for Tropical Diseases in Bangkok, Thailand between October 2013 and July 2015. Data, including baseline characteristics, clinical parameters, laboratory findings, serum PCT and PVL levels, management, and outcomes, were recorded on pre-defined case report forms. Of 160 patients with dengue, 128 (80.0% patients had dengue without shock or organ failure, whereas 32 (20.0% patients developed dengue with shock and/or organ failure. Using a stepwise multivariate logistic regression analysis, PCT ≥0.7 ng/mL (odds ratio [OR]: 4.80; 95% confidence interval [CI]: 1.60-14.45; p = 0.005 and PVL ≥2.5 mmol/L (OR: 27.99, 95% CI: 8.47-92.53; p <0.001 were independently associated with dengue shock and/or organ failure. A combination of PCT ≥0.7 ng/mL and PVL ≥2.5 mmol/L provided good prognostic value for predicting dengue shock and/or organ failure, with an area under the receiver operating characteristics curve of 0.83 (95% CI: 0.74-0.92, a sensitivity of 81.2% (95% CI: 63.6-92.8%, and a specificity of 84.4% (95% CI: 76.9-90.2%. Dengue shock patients with non-clearance of PCT and PVL expired during hospitalization.PCT ≥0.7 ng/mL and PVL ≥2.5 mmol/L were independently associated with dengue shock and/or organ failure. The combination of PCT and PVL levels could be used as prognostic biomarkers for the prediction of dengue shock and/or organ failure.

  5. A model for predicting embankment slope failures in clay-rich soils; A Louisiana example

    Science.gov (United States)

    Burns, S. F.

    2015-12-01

    A model for predicting embankment slope failures in clay-rich soils; A Louisiana example It is well known that smectite-rich soils significantly reduce the stability of slopes. The question is how much smectite in the soil causes slope failures. A study of over 100 sites in north and south Louisiana, USA, compared slopes that failed during a major El Nino winter (heavy rainfall) in 1982-1983 to similar slopes that did not fail. Soils in the slopes were tested for per cent clay, liquid limits, plasticity indices and semi-quantitative clay mineralogy. Slopes with the High Risk for failure (85-90% chance of failure in 8-15 years after construction) contained soils with a liquid limit > 54%, a plasticity index over 29%, and clay contents > 47%. Slopes with an Intermediate Risk (55-50% chance of failure in 8-15 years) contained soils with a liquid limit between 36-54%, plasticity index between 16-19%, and clay content between 32-47%. Slopes with a Low Risk chance of failure (soils with a liquid limit plasticity index soil characteristics before construction. If the soils fall into the Low Risk classification, construct the embankment normally. If the soils fall into the High Risk classification, one will need to use lime stabilization or heat treatments to prevent failures. Soils in the Intermediate Risk class will have to be evaluated on a case by case basis.

  6. Prediction of failure in tube hydrofonning process using a damage model

    International Nuclear Information System (INIS)

    Majzoobi, G. H.; Saniee, F. Freshteh; Shirazi, A.

    2007-01-01

    In tube hydroforming process (THP), two types of loading, internal pressure and axial feeding and in particular the combination of them, are needed to feed the material into the cavities of the die to form the workpiece into the desired shape. If the variation of pressure versus axial feeding is not determined properly, the workpiece may be buckled, wrinkled or burst during THP. The appropriate variation is normally determined by experiment which is expensive and time-consuming. In this work, numerical simulation using Johnson-Cook models for predicting the elasto-plastic response and the failure of the material are employed to obtain the best combination of internal pressure and axial feeding. The numerical simulations are examined by a number of experiments conducted in the present investigation. The results show very close agreement between the numerical simulations and the experiments, suggesting that the numerical simulations using Johnson-Cook material and failure models provide a valuable tool to examine the different parameters involved in THP

  7. Failure analysis and seal life prediction for contacting mechanical seals

    Science.gov (United States)

    Sun, J. J.; He, X. Y.; Wei, L.; Feng, X.

    2008-11-01

    Fault tree analysis method was applied to quantitatively investigate the causes of the leakage failure of mechanical seals. It is pointed out that the change of the surface topography is the main reasons causing the leakage of mechanical seals under the condition of constant preloads. Based on the fractal geometry theory, the relationship between the surface topography and working time were investigated by experiments, and the effects of unit load acting on seal face on leakage path in a mechanical seal were analyzed. The model of predicting seal life of mechanical seals was established on the basis of the relationship between the surface topography and working time and allowable leakage. The seal life of 108 mechanical seal operating at the system of diesel fuel storage and transportation was predicted and the problem of the condition monitoring for the long-period operation of mechanical seal was discussed by this method. The research results indicate that the method of predicting seal life of mechanical seals is feasible, and also is foundation to make scheduled maintenance time and to achieve safe-reliability and low-cost operation for industrial devices.

  8. Vertebral body spread in thoracolumbar burst fractures can predict posterior construct failure.

    Science.gov (United States)

    De Iure, Federico; Lofrese, Giorgio; De Bonis, Pasquale; Cultrera, Francesco; Cappuccio, Michele; Battisti, Sofia

    2018-06-01

    The load sharing classification (LSC) laid foundations for a scoring system able to indicate which thoracolumbar fractures, after short-segment posterior-only fixations, would need longer instrumentations or additional anterior supports. We analyzed surgically treated thoracolumbar fractures, quantifying the vertebral body's fragment displacement with the aim of identifying a new parameter that could predict the posterior-only construct failure. This is a retrospective cohort study from a single institution. One hundred twenty-one consecutive patients were surgically treated for thoracolumbar burst fractures. Grade of kyphosis correction (GKC) expressed radiological outcome; Oswestry Disability Index and visual analog scale were considered. One hundred twenty-one consecutive patients who underwent posterior fixation for unstable thoracolumbar burst fractures were retrospectively evaluated clinically and radiologically. Supplementary anterior fixations were performed in 34 cases with posterior instrumentation failure, determined on clinic-radiological evidence or symptomatic loss of kyphosis correction. Segmental kyphosis angle and GKC were calculated according to the Cobb method. The displacement of fracture fragments was obtained from the mean of the adjacent end plate areas subtracted from the area enclosed by the maximum contour of vertebral fragmentation. The "spread" was derived from the ratio between this subtraction and the mean of the adjacent end plate areas. Analysis of variance, Mann-Whitney, and receiver operating characteristic were performed for statistical analysis. The authors report no conflict of interest concerning the materials or methods used in the present study or the findings specified in this paper. No funds or grants have been received for the present study. The spread revealed to be a helpful quantitative measurement of vertebral body fragment displacement, easily reproducible with the current computed tomography (CT) imaging technologies

  9. Implicit and explicit attitudes predict smoking cessation: moderating effects of experienced failure to control smoking and plans to quit.

    Science.gov (United States)

    Chassin, Laurie; Presson, Clark C; Sherman, Steven J; Seo, Dong-Chul; Macy, Jonathan T

    2010-12-01

    The current study tested implicit and explicit attitudes as prospective predictors of smoking cessation in a Midwestern community sample of smokers. Results showed that the effects of attitudes significantly varied with levels of experienced failure to control smoking and plans to quit. Explicit attitudes significantly predicted later cessation among those with low (but not high or average) levels of experienced failure to control smoking. Conversely, however, implicit attitudes significantly predicted later cessation among those with high levels of experienced failure to control smoking, but only if they had a plan to quit. Because smoking cessation involves both controlled and automatic processes, interventions may need to consider attitude change interventions that focus on both implicit and explicit attitudes. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

  10. Predicting short-term mortality in advanced decompensated heart failure - role of the updated acute decompensated heart failure/N-terminal pro-B-type natriuretic Peptide risk score.

    Science.gov (United States)

    Scrutinio, Domenico; Ammirati, Enrico; Passantino, Andrea; Guida, Pietro; D'Angelo, Luciana; Oliva, Fabrizio; Ciccone, Marco Matteo; Iacoviello, Massimo; Dentamaro, Ilaria; Santoro, Daniela; Lagioia, Rocco; Sarzi Braga, Simona; Guzzetti, Daniela; Frigerio, Maria

    2015-01-01

    The first few months after admission are the most vulnerable period in patients with acute decompensated heart failure (ADHF). We assessed the association of the updated ADHF/N-terminal pro-B-type natriuretic peptide (NT-proBNP) risk score with 90-day and in-hospital mortality in 701 patients admitted with advanced ADHF, defined as severe symptoms of worsening HF, severely depressed left ventricular ejection fraction, and the need for i.v. diuretic and/or inotropic drugs. A total of 15.7% of the patients died within 90 days of admission and 5.2% underwent ventricular assist device (VAD) implantation or urgent heart transplantation (UHT). The C-statistic of the ADHF/NT-proBNP risk score for 90-day mortality was 0.810 (95% CI: 0.769-0.852). Predicted and observed mortality rates were in close agreement. When the composite outcome of death/VAD/UHT at 90 days was considered, the C-statistic decreased to 0.741. During hospitalization, 7.6% of the patients died. The C-statistic for in-hospital mortality was 0.815 (95% CI: 0.761-0.868) and Hosmer-Lemeshow χ(2)=3.71 (P=0.716). The updated ADHF/NT-proBNP risk score outperformed the Acute Decompensated Heart Failure National Registry, the Organized Program to Initiate Lifesaving Treatment in Patients Hospitalized for Heart Failure, and the American Heart Association Get with the Guidelines Program predictive models. Updated ADHF/NT-proBNP risk score is a valuable tool for predicting short-term mortality in severe ADHF, outperforming existing inpatient predictive models.

  11. Availability of anesthetic effect monitoring: utilization, intraoperative management and time to extubation in liver transplantation.

    Science.gov (United States)

    Schumann, R; Hudcova, J; Bonney, I; Cepeda, M S

    2010-12-01

    Titration of volatile anesthetics to anesthetic effect monitoring using the bispectral index (BIS) has been shown to decrease anesthetic requirements and facilitate recovery from anesthesia unrelated to liver transplantation (OLT). To determine whether availability of such monitoring influences its utilization pattern and affect anesthetic care and outcomes in OLT, we conducted a retrospective analysis in recipients with and without such monitoring. We evaluated annual BIS utilization over a period of 7 years, and compared 41 BIS-monitored patients to 42 controls. All received an isoflurane/air/oxygen and opioid-based anesthetic with planned postoperative ventilation. Data collection included age, body mass index (BMI), gender, Model for End-stage Liver Disease (MELD) score, and time to extubation (TtE). Mean preanhepatic, anhepatic, and postanhepatic end-tidal isoflurane concentrations were compared, as well as BIS values for each phase of OLT using the Kruskal-Wallis and Wilcoxon signed-rank tests, respectively. The use of anesthetic effect monitoring when available increased steadily from 15% of cases in the first year to almost 93% by year 7. There was no significant difference in age, gender, BMI, MELD, or TtE between groups. The BIS group received less inhalational anesthetic during each phase of OLT compared to the control group. However, this difference was statistically significant only during the anhepatic phase (P = .026), and was clinically not impressive. Within the BIS group, the mean BIS value was 38.74 ± 5.25 (mean ± standard deviation), and there was no difference for the BIS value between different transplant phases. Availability of anesthetic effect monitoring as an optional monitoring tool during OLT results in its increasing utilization by anesthesia care teams over time. However, unless integrated into an intraoperative algorithm and an early extubation protocol for fast tracking of OLT recipients, this utilization does not appear to provide

  12. A relation to predict the failure of materials and potential application to volcanic eruptions and landslides.

    Science.gov (United States)

    Hao, Shengwang; Liu, Chao; Lu, Chunsheng; Elsworth, Derek

    2016-06-16

    A theoretical explanation of a time-to-failure relation is presented, with this relationship then used to describe the failure of materials. This provides the potential to predict timing (tf - t) immediately before failure by extrapolating the trajectory as it asymptotes to zero with no need to fit unknown exponents as previously proposed in critical power law behaviors. This generalized relation is verified by comparison with approaches to criticality for volcanic eruptions and creep failure. A new relation based on changes with stress is proposed as an alternative expression of Voight's relation, which is widely used to describe the accelerating precursory signals before material failure and broadly applied to volcanic eruptions, landslides and other phenomena. The new generalized relation reduces to Voight's relation if stress is limited to increase at a constant rate with time. This implies that the time-derivatives in Voight's analysis may be a subset of a more general expression connecting stress derivatives, and thus provides a potential method for forecasting these events.

  13. What Predicts Children's Fixed and Growth Intelligence Mind-Sets? Not Their Parents' Views of Intelligence but Their Parents' Views of Failure.

    Science.gov (United States)

    Haimovitz, Kyla; Dweck, Carol S

    2016-06-01

    Children's intelligence mind-sets (i.e., their beliefs about whether intelligence is fixed or malleable) robustly influence their motivation and learning. Yet, surprisingly, research has not linked parents' intelligence mind-sets to their children's. We tested the hypothesis that a different belief of parents-their failure mind-sets-may be more visible to children and therefore more prominent in shaping their beliefs. In Study 1, we found that parents can view failure as debilitating or enhancing, and that these failure mind-sets predict parenting practices and, in turn, children's intelligence mind-sets. Study 2 probed more deeply into how parents display failure mind-sets. In Study 3a, we found that children can indeed accurately perceive their parents' failure mind-sets but not their parents' intelligence mind-sets. Study 3b showed that children's perceptions of their parents' failure mind-sets also predicted their own intelligence mind-sets. Finally, Study 4 showed a causal effect of parents' failure mind-sets on their responses to their children's hypothetical failure. Overall, parents who see failure as debilitating focus on their children's performance and ability rather than on their children's learning, and their children, in turn, tend to believe that intelligence is fixed rather than malleable. © The Author(s) 2016.

  14. Predicting material failure using mathematics; Mit Mathematik Materialversagen vorhersagen

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Christian [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany)

    2016-06-15

    Numerical simulations provide insights into materials, technical procedures or processes that are hardly possible by means of measurement technology, or require a lot of effort. In BAM's ConDrop research project (Numerical Drop Test Analyses of Steel Sheet Containers for the Konrad Repository), scientists are developing a method to predict the deformation and failure behaviour of containers for low- and intermediate- level radioactive waste for the Konrad repository. [German] Numerische Simulationen erlauben Einblicke in Materialien, technische Verfahren oder Prozesse, die mit Mitteln der Messtechnik kaum oder nur unter grossem Aufwand moeglich sind. Im BAM-Forschungsvorhaben ConDrop entwickeln Wissenschaftlerinnen und Wissenschaftler damit eine Methode, um das Verformungs- und Versagensverhalten von Behaeltern fuer schwach- und mittelradioaktive Abfaelle fuer das Endlager Konrad vorherzusagen.

  15. Failure prediction for the optimization of stretch forming aluminium-polymer laminate foils used for pharmaceutical packaging

    Science.gov (United States)

    Müller, Simon; Weygand, Sabine M.

    2018-05-01

    Axisymmetric stretch forming processes of aluminium-polymer laminate foils (e.g. consisting of PA-Al-PVC layers) are analyzed numerically by finite element modeling of the multi-layer material as well as experimentally in order to identify a suitable damage initiation criterion. A simple ductile fracture criterion is proposed to predict the forming limits. The corresponding material constants are determined from tensile tests and then applied in forming simulations with different punch geometries. A comparison between the simulations and the experimental results shows that the determined failure constants are not applicable. Therefore, one forming experiment was selected and in the corresponding simulation the failure constant was fitted to its measured maximum stretch. With this approach it is possible to predict the forming limit of the laminate foil with satisfying accuracy for different punch geometries.

  16. Failure of Noninvasive Ventilation for De Novo Acute Hypoxemic Respiratory Failure: Role of Tidal Volume.

    Science.gov (United States)

    Carteaux, Guillaume; Millán-Guilarte, Teresa; De Prost, Nicolas; Razazi, Keyvan; Abid, Shariq; Thille, Arnaud W; Schortgen, Frédérique; Brochard, Laurent; Brun-Buisson, Christian; Mekontso Dessap, Armand

    2016-02-01

    A low or moderate expired tidal volume can be difficult to achieve during noninvasive ventilation for de novo acute hypoxemic respiratory failure (i.e., not due to exacerbation of chronic lung disease or cardiac failure). We assessed expired tidal volume and its association with noninvasive ventilation outcome. Prospective observational study. Twenty-four bed university medical ICU. Consecutive patients receiving noninvasive ventilation for acute hypoxemic respiratory failure between August 2010 and February 2013. Noninvasive ventilation was uniformly delivered using a simple algorithm targeting the expired tidal volume between 6 and 8 mL/kg of predicted body weight. Expired tidal volume was averaged and respiratory and hemodynamic variables were systematically recorded at each noninvasive ventilation session. Sixty-two patients were enrolled, including 47 meeting criteria for acute respiratory distress syndrome, and 32 failed noninvasive ventilation (51%). Pneumonia (n = 51, 82%) was the main etiology of acute hypoxemic respiratory failure. The median (interquartile range) expired tidal volume averaged over all noninvasive ventilation sessions (mean expired tidal volume) was 9.8 mL/kg predicted body weight (8.1-11.1 mL/kg predicted body weight). The mean expired tidal volume was significantly higher in patients who failed noninvasive ventilation as compared with those who succeeded (10.6 mL/kg predicted body weight [9.6-12.0] vs 8.5 mL/kg predicted body weight [7.6-10.2]; p = 0.001), and expired tidal volume was independently associated with noninvasive ventilation failure in multivariate analysis. This effect was mainly driven by patients with PaO2/FIO2 up to 200 mm Hg. In these patients, the expired tidal volume above 9.5 mL/kg predicted body weight predicted noninvasive ventilation failure with a sensitivity of 82% and a specificity of 87%. A low expired tidal volume is almost impossible to achieve in the majority of patients receiving noninvasive ventilation

  17. Defining and predicting 'intrauterine fetal renal failure' in congenital lower urinary tract obstruction.

    Science.gov (United States)

    Ruano, Rodrigo; Safdar, Adnan; Au, Jason; Koh, Chester J; Gargollo, Patricio; Shamshirsaz, Alireza A; Espinoza, Jimmy; Cass, Darrell L; Olutoye, Oluyinka O; Olutoye, Olutoyin A; Welty, Stephen; Roth, David R; Belfort, Michael A; Braun, Michael C

    2016-04-01

    The aim of this study was to identify predictors of 'intrauterine fetal renal failure' in fetuses with severe congenital lower urinary tract obstruction (LUTO). We undertook a retrospective study of 31 consecutive fetuses with a diagnosis of LUTO in a tertiary Fetal Center between April 2013 and April 2015. Predictors of 'intrauterine fetal renal failure' were evaluated in those infants with severe LUTO who had either a primary composite outcome measure of neonatal death in the first 24 h of life due to severe pulmonary hypoplasia or a need for renal replacement therapy within 7 days of life. The following variables were analyzed: fetal bladder re-expansion 48 h after vesicocentesis, fetal renal ultrasound characteristics, fetal urinary indices, and amniotic fluid volume. Of the 31 fetuses included in the study, eight met the criteria for 'intrauterine fetal renal failure'. All of the latter had composite poor postnatal outcomes based on death within 24 h of life (n = 6) or need for dialysis within 1 week of life (n = 2). The percentage of fetal bladder refilling after vesicocentesis at time of initial evaluation was the only predictor of 'intrauterine fetal renal failure' (cut-off <27 %, area under the time-concentration curve 0.86, 95 % confidence interval 0.68-0.99; p = 0.009). We propose the concept of 'intrauterine fetal renal failure' in fetuses with the most severe forms of LUTO. Fetal bladder refilling can be used to reliably predict 'intrauterine fetal renal failure', which is associated with severe pulmonary hypoplasia or the need for dialysis within a few days of life.

  18. Prediction of line failure fault based on weighted fuzzy dynamic clustering and improved relational analysis

    Science.gov (United States)

    Meng, Xiaocheng; Che, Renfei; Gao, Shi; He, Juntao

    2018-04-01

    With the advent of large data age, power system research has entered a new stage. At present, the main application of large data in the power system is the early warning analysis of the power equipment, that is, by collecting the relevant historical fault data information, the system security is improved by predicting the early warning and failure rate of different kinds of equipment under certain relational factors. In this paper, a method of line failure rate warning is proposed. Firstly, fuzzy dynamic clustering is carried out based on the collected historical information. Considering the imbalance between the attributes, the coefficient of variation is given to the corresponding weights. And then use the weighted fuzzy clustering to deal with the data more effectively. Then, by analyzing the basic idea and basic properties of the relational analysis model theory, the gray relational model is improved by combining the slope and the Deng model. And the incremental composition and composition of the two sequences are also considered to the gray relational model to obtain the gray relational degree between the various samples. The failure rate is predicted according to the principle of weighting. Finally, the concrete process is expounded by an example, and the validity and superiority of the proposed method are verified.

  19. Economic sustainability in franchising: a model to predict franchisor success or failure

    OpenAIRE

    Calderón Monge, Esther; Pastor Sanz, Ivan .; Huerta Zavala, Pilar Angélica

    2017-01-01

    As a business model, franchising makes a major contribution to gross domestic product (GDP). A model that predicts franchisor success or failure is therefore necessary to ensure economic sustainability. In this study, such a model was developed by applying Lasso regression to a sample of franchises operating between 2002 and 2013. For franchises with the highest likelihood of survival, the franchise fees and the ratio of company-owned to franchised outlets were suited to the age ...

  20. Lower head failure analysis

    International Nuclear Information System (INIS)

    Rempe, J.L.; Thinnes, G.L.; Allison, C.M.; Cronenberg, A.W.

    1991-01-01

    The US Nuclear Regulatory Commission is sponsoring a lower vessel head research program to investigate plausible modes of reactor vessel failure in order to determine (a) which modes have the greatest likelihood of occurrence during a severe accident and (b) the range of core debris and accident conditions that lead to these failures. This paper presents the methodology and preliminary results of an investigation of reactor designs and thermodynamic conditions using analytic closed-form approximations to assess the important governing parameters in non-dimensional form. Preliminary results illustrate the importance of vessel and tube geometrical parameters, material properties, and external boundary conditions on predicting vessel failure. Thermal analyses indicate that steady-state temperature distributions will occur in the vessel within several hours, although the exact time is dependent upon vessel thickness. In-vessel tube failure is governed by the tube-to-debris mass ratio within the lower head, where most penetrations are predicted to fail if surrounded by molten debris. Melt penetration distance is dependent upon the effective flow diameter of the tube. Molten debris is predicted to penetrate through tubes with a larger effective flow diameter, such as a boiling water reactor (BWR) drain nozzle. Ex-vessel tube failure for depressurized reactor vessels is predicted to be more likely for a BWR drain nozzle penetration because of its larger effective diameter. At high pressures (between ∼0.1 MPa and ∼12 MPa) ex-vessel tube rupture becomes a dominant failure mechanism, although tube ejection dominates control rod guide tube failure at lower temperatures. However, tube ejection and tube rupture predictions are sensitive to the vessel and tube radial gap size and material coefficients of thermal expansion

  1. Slope Failure Prediction and Early Warning Awareness Education for Reducing Landslides Casualty in Malaysia

    Science.gov (United States)

    Koay, S. P.; Tay, L. T.; Fukuoka, H.; Koyama, T.; Sakai, N.; Jamaludin, S. B.; Lateh, H.

    2015-12-01

    Northeast monsoon causes heavy rain in east coast of Peninsular Malaysia from November to March, every year. During this monsoon period, besides the happening of flood along east coast, landslides also causes millions of Malaysian Ringgit economical losses. Hence, it is essential to study the prediction of slope failure to prevent the casualty of landslides happening. In our study, we introduce prediction method of the accumulated rainfall affecting the stability of the slope. If the curve, in the graph, which is presented by rainfall intensity versus accumulated rainfall, crosses over the critical line, the condition of the slope is considered in high risk where the data are calculated and sent from rain gauge in the site via internet. If the possibility of slope failure is going high, the alert message will be sent out to the authorities for decision making on road block or setting the warning light at the road side. Besides road block and warning light, we propose to disseminate short message, to pre-registered mobile phone user, to notify the public for easing the traffic jam and avoiding unnecessary public panic. Prediction is not enough to prevent the casualty. Early warning awareness of the public is very important to reduce the casualty of landslides happening. IT technology does not only play a main role in disseminating information, early warning awareness education, by using IT technology, should be conducted, in schools, to give early warning awareness on natural hazard since childhood. Knowing the pass history on landslides occurrence will gain experience on the landslides happening. Landslides historical events with coordinate information are stored in database. The public can browse these historical events via internet. By referring to such historical landslides events, the public may know where did landslides happen before and the possibility of slope failure occurrence again is considered high. Simulation of rainfall induced slope failure mechanism

  2. Bayesian framework for prediction of future number of failures from a single group of units in the field

    International Nuclear Information System (INIS)

    Ebrahimi, Nader

    2009-01-01

    This paper considers prediction of unknown number of failures in a future inspection of a group of in-service units based on number of failures observed from an earlier inspection. We develop a flexible Bayesian model and calculate Bayesian estimator for this unknown number and other quantities of interest. The paper also includes an illustration of our method in an example about heat exchanger. A main advantage of our approach is in its nonparametric nature. By nonparametric here we simply mean that no assumption is required about the failure time distribution of a unit

  3. A single-item self-report medication adherence question predicts hospitalisation and death in patients with heart failure.

    Science.gov (United States)

    Wu, Jia-Rong; DeWalt, Darren A; Baker, David W; Schillinger, Dean; Ruo, Bernice; Bibbins-Domingo, Kristen; Macabasco-O'Connell, Aurelia; Holmes, George M; Broucksou, Kimberly A; Erman, Brian; Hawk, Victoria; Cene, Crystal W; Jones, Christine DeLong; Pignone, Michael

    2014-09-01

    To determine whether a single-item self-report medication adherence question predicts hospitalisation and death in patients with heart failure. Poor medication adherence is associated with increased morbidity and mortality. Having a simple means of identifying suboptimal medication adherence could help identify at-risk patients for interventions. We performed a prospective cohort study in 592 participants with heart failure within a four-site randomised trial. Self-report medication adherence was assessed at baseline using a single-item question: 'Over the past seven days, how many times did you miss a dose of any of your heart medication?' Participants who reported no missing doses were defined as fully adherent, and those missing more than one dose were considered less than fully adherent. The primary outcome was combined all-cause hospitalisation or death over one year and the secondary endpoint was heart failure hospitalisation. Outcomes were assessed with blinded chart reviews, and heart failure outcomes were determined by a blinded adjudication committee. We used negative binomial regression to examine the relationship between medication adherence and outcomes. Fifty-two percent of participants were 52% male, mean age was 61 years, and 31% were of New York Heart Association class III/IV at enrolment; 72% of participants reported full adherence to their heart medicine at baseline. Participants with full medication adherence had a lower rate of all-cause hospitalisation and death (0·71 events/year) compared with those with any nonadherence (0·86 events/year): adjusted-for-site incidence rate ratio was 0·83, fully adjusted incidence rate ratio 0·68. Incidence rate ratios were similar for heart failure hospitalisations. A single medication adherence question at baseline predicts hospitalisation and death over one year in heart failure patients. Medication adherence is associated with all-cause and heart failure-related hospitalisation and death in heart

  4. In vitro/in silico investigation of failure criteria to predict flexural strength of composite resins.

    Science.gov (United States)

    Yamaguchi, Satoshi; Mehdawi, Idris Mohamed; Sakai, Takahiko; Abe, Tomohiro; Inoue, Sayuri; Imazato, Satoshi

    2018-01-30

    The aim of this study was to investigate a failure criterion to predict flexural strengths of composite resins (CR) by three-dimensional finite element analysis (3D-FEA). Models of flexural strength for test specimens of CR and rods comprising a three-point loading were designed. Calculation of Young's moduli and Poisson's ratios of CR were conducted using a modified McGee-McCullough model. Using the experimental CR, flexural strengths were measured by three-point bending tests with crosshead speed 1.0 mm/min and compared with the values determined by in silico analysis. The flexural strengths of experimental CR calculated using the maximum principal strain significantly correlated with those obtained in silico amongst the four types of failure criteria applied. The in silico analytical model established in this study was found to be effective to predict the flexural strengths of CR incorporating various silica filler contents by maximum principal strain.

  5. Predictive factors for the failure of endoscopic stent-in-stent self-expandable metallic stent placement to treat malignant hilar biliary obstruction.

    Science.gov (United States)

    Sugimoto, Mitsuru; Takagi, Tadayuki; Suzuki, Rei; Konno, Naoki; Asama, Hiroyuki; Watanabe, Ko; Nakamura, Jun; Kikuchi, Hitomi; Waragai, Yuichi; Takasumi, Mika; Sato, Yuki; Hikichi, Takuto; Ohira, Hiromasa

    2017-09-14

    To investigate the factors predictive of failure when placing a second biliary self-expandable metallic stents (SEMSs). This study evaluated 65 patients with an unresectable malignant hilar biliary obstruction who were examined in our hospital. Sixty-two of these patients were recruited to the study and divided into two groups: the success group, which consisted of patients in whom a stent-in-stent SEMS had been placed successfully, and the failure group, which consisted of patients in whom the stent-in-stent SEMS had not been placed successfully. We compared the characteristics of the patients, the stricture state of their biliary ducts, and the implemented endoscopic retrograde cholangiopancreatography (ERCP) procedures between the two groups. The angle between the target biliary duct stricture and the first implanted SEMS was significantly larger in the failure group than in the success group. There were significantly fewer wire or dilation devices (ERCP catheter, dilator, or balloon catheter) passing the first SEMS cell in the failure group than in the success group. The cut-off value of the angle predicting stent-in-stent SEMS placement failure was 49.7 degrees according to the ROC curve (sensitivity 91.7%, specificity 61.2%). Furthermore, the angle was significantly smaller in patients with wire or dilation devices passing the first SEMS cell than in patients without wire or dilation devices passing the first SEMS cell. A large angle was identified as a predictive factor for failure of stent-in-stent SEMS placement.

  6. [Non-verbal communication of patients submitted to heart surgery: from awaking after anesthesia to extubation].

    Science.gov (United States)

    Werlang, Sueli da Cruz; Azzolin, Karina; Moraes, Maria Antonieta; de Souza, Emiliane Nogueira

    2008-12-01

    Preoperative orientation is an essential tool for patient's communication after surgery. This study had the objective of evaluating non-verbal communication of patients submitted to cardiac surgery from the time of awaking from anesthesia until extubation, after having received preoperative orientation by nurses. A quantitative cross-sectional study was developed in a reference hospital of the state of Rio Grande do Sul, Brazil, from March to July 2006. Data were collected in the pre and post operative periods. A questionnaire to evaluate non-verbal communication on awaking from sedation was applied to a sample of 100 patients. Statistical analysis included Student, Wilcoxon, and Mann Whittney tests. Most of the patients responded satisfactorily to non-verbal communication strategies as instructed on the preoperative orientation. Thus, non-verbal communication based on preoperative orientation was helpful during the awaking period.

  7. Bulbar impairment score predicts noninvasive volume-cycled ventilation failure during an acute lower respiratory tract infection in ALS.

    Science.gov (United States)

    Servera, Emilio; Sancho, Jesús; Bañuls, Pilar; Marín, Julio

    2015-11-15

    Amyotrophic lateral sclerosis (ALS) patients can suffer episodes of lower respiratory tract infections (LRTI) leading to an acute respiratory failure (ARF) requiring noninvasive ventilation (NIV). To determine whether clinical or functional parameters can predict noninvasive management failure during LRTI causing ARF in ALS. A prospective study involving all ALS patients with ARF requiring NIV in a Respiratory Care Unit. NIV was provided with volume-cycled ventilators. 63 ALS patients were included (APACHE II: 14.93±3.56, Norris bulbar subscore (NBS): 18.78±9.68, ALSFRS-R: 19.90±6.98, %FVC: 40.01±18.07%, MIC: 1.62±0.74L, PCF 2.51±1.15L/s, PImax -34.90±19.44cmH2O, PEmax 51.20±28.84cmH2O). In 73.0% of patients NIV was successful in averting death or endotracheal intubation. Differences were found between the success and failure in the NBS (22.08±6.15 vs 8.66±3.39, pNIV failure was the NBS (OR 0.53, 95% CI 0.31-0.92, p 0.002) with a cut-off point of 12 (S 0.93; E 0.97; PPV 0.76; NPV 0.97). NBS can predict noninvasive management failure during LRTI in ALS. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Failure criterion effect on solid production prediction and selection of completion solution

    Directory of Open Access Journals (Sweden)

    Dariush Javani

    2017-12-01

    Full Text Available Production of fines together with reservoir fluid is called solid production. It varies from a few grams or less per ton of reservoir fluid posing only minor problems, to catastrophic amount possibly leading to erosion and complete filling of the borehole. This paper assesses solid production potential in a carbonate gas reservoir located in the south of Iran. Petrophysical logs obtained from the vertical well were employed to construct mechanical earth model. Then, two failure criteria, i.e. Mohr–Coulomb and Mogi–Coulomb, were used to investigate the potential of solid production of the well in the initial and depleted conditions of the reservoir. Using these two criteria, we estimated critical collapse pressure and compared them to the reservoir pressure. Solid production occurs if collapse pressure is greater than pore pressure. Results indicate that the two failure criteria show different estimations of solid production potential of the studied reservoir. Mohr–Coulomb failure criterion estimated solid production in both initial and depleted conditions, where Mogi–Coulomb criterion predicted no solid production in the initial condition of reservoir. Based on Mogi–Coulomb criterion, the well may not require completion solutions like perforated liner, until at least 60% of reservoir pressure was depleted which leads to decrease in operation cost and time.

  9. Perfectionism and self-conscious emotions in British and Japanese students: Predicting pride and embarrassment after success and failure

    OpenAIRE

    Stoeber, Joachim; Kobori, Osamu; Tanno, Yoshihiko

    2013-01-01

    Regarding self-conscious emotions, studies have shown that different forms of perfectionism show different relationships with pride, shame, and embarrassment depending on success and failure. What is unknown is whether these relationships also show cultural variations. Therefore, we conducted a study investigating how self-oriented and socially prescribed perfectionism predicted pride and embarrassment after success and failure comparing 363 British and 352 Japanese students. Students were as...

  10. Predicting survival in heart failure

    DEFF Research Database (Denmark)

    Pocock, Stuart J; Ariti, Cono A; McMurray, John J V

    2012-01-01

    AimsUsing a large international database from multiple cohort studies, the aim is to create a generalizable easily used risk score for mortality in patients with heart failure (HF).Methods and resultsThe MAGGIC meta-analysis includes individual data on 39 372 patients with HF, both reduced...

  11. Prostate cancer volume adds significantly to prostate-specific antigen in the prediction of early biochemical failure after external beam radiation therapy

    International Nuclear Information System (INIS)

    D'Amico, Anthony V.; Propert, Kathleen J.

    1996-01-01

    Purpose: A new clinical pretreatment quantity that closely approximates the true prostate cancer volume is defined. Methods and Materials: The cancer-specific prostate-specific antigen (PSA), PSA density, prostate cancer volume (V Ca ), and the volume fraction of the gland involved with carcinoma (V Ca fx) were calculated for 227 prostate cancer patients managed definitively with external beam radiation therapy. 1. PSA density PSA/ultrasound prostate gland volume 2. Cancer-specific PSA = PSA - [PSA from benign epithelial tissue] 3. V Ca = Cancer-specific PSA/[PSA in serum per cm 3 of cancer] 4. V Ca fx = V Ca /ultrasound prostate gland volume A Cox multiple regression analysis was used to test whether any of these-clinical pretreatment parameters added significantly to PSA in predicting early postradiation PSA failure. Results: The prostate cancer volume (p = 0.039) and the volume fraction of the gland involved by carcinoma (p = 0.035) significantly added to the PSA in predicting postradiation PSA failure. Conversely, the PSA density and the cancer-specific PSA did not add significantly (p > 0.05) to PSA in predicting postradiation PSA failure. The 20-month actuarial PSA failure-free rates for patients with calculated tumor volumes of ≤0.5 cm 3 , 0.5-4.0 cm 3 , and >4.0 cm 3 were 92, 80, and 47%, respectively (p = 0.00004). Conclusion: The volume of prostate cancer (V Ca ) and the resulting volume fraction of cancer both added significantly to PSA in their ability to predict for early postradiation PSA failure. These new parameters may be used to select patients in prospective randomized trials that examine the efficacy of combining radiation and androgen ablative therapy in patients with clinically localized disease, who are at high risk for early postradiation PSA failure

  12. Parent reports of health-related quality of life and heart failure severity score independently predict outcome in children with dilated cardiomyopathy.

    Science.gov (United States)

    den Boer, Susanna L; Baart, Sara J; van der Meulen, Marijke H; van Iperen, Gabriëlle G; Backx, Ad P; Ten Harkel, Arend D; Rammeloo, Lukas A; du Marchie Sarvaas, Gideon J; Tanke, Ronald B; Helbing, Willem A; Utens, Elisabeth M; Dalinghaus, Michiel

    2017-08-01

    Dilated cardiomyopathy in children causes heart failure and has a poor prognosis. Health-related quality of life in this patient group is unknown. Moreover, results may provide detailed information of parents' sense of their child's functioning. We hypothesised that health-related quality of life, as rated by parents, and the paediatric heart failure score, as assessed by physicians, have both predictive value on outcome. Methods and results In this prospective study, health-related quality of life was assessed by parent reports: the Infant Toddler Quality of Life questionnaire (0-4 years) or Child Health Questionnaire-Parent Form 50 (4-18 years) at 3-6-month intervals. We included 90 children (median age 3.8 years, interquartile range (IQR) 0.9-12.3) whose parents completed 515 questionnaires. At the same visit, physicians completed the New York University Pediatric Heart Failure Index. Compared with Dutch normative data, quality of life was severely impaired at diagnosis (0-4 years: 7/10 subscales and 4-18 years: 8/11 subscales) and ⩾1 year after diagnosis (3/10 and 6/11 subscales). Older children were more impaired (pFailure Index were independently predictive of the risk of death and heart transplantation (hazard ratio 1.24 per 10% decrease of predicted, 95% confidence interval (CI) 1.06-1.47 and hazard ratio 1.38 per unit, 95% CI 1.19-1.61, respectively). Physical impairment rated by parents and heart failure severity assessed by physicians independently predicted the risk of death or heart transplantation in children with dilated cardiomyopathy.

  13. Successful treatment of 54 patients with acute renal failure after cardiac surgery

    Directory of Open Access Journals (Sweden)

    Lei CHEN

    2015-06-01

    Full Text Available Objectives To evaluate the result of treatment of acute renal failure (ARF in patients after cardiac surgery. Methods The clinical data of 54 cases admitted to the hospital from Jan. 2004 to Jan. 2014 and suffered from ARF after cardiac surgery were retrospectively analyzed. Among 54 cases, there were 35 males and 19 females, aged from one month to 79 years with a median of 52 years. The surgical procedures included coronary artery bypass grafting (CABG, 10 cases, valve surgery (22 cases, combined CABG and valve surgery (4 cases, operation on aorta (14 case, and radical correction of Fallot tetralogy (4 cases. After the operations mentioned above, 50 patients received continuous renal replacement therapy (CRRT, and 4 patients received peritoneal dialysis. Results Nine patients died, the mortality rate was 16.7%. Exploratory hemostasis by thoracotomy was performed in 8 patients, and extubation failure occurred in 4 cases. Of the 9 non-survivors, 6 died from multiple organ failure (MOF, 2 died from cerebral hemorrhage, and one died from acute respiratory failure. Serum creatinine (SCr and blood urea nitrogen (BUN levels declined obviously after CRRT and peritoneal dialysis (P<0.05, and all the patients were shown to have stable hemodynamics in the course of treatment, and no hemorrhage or embolism occurred. Conclusions ARF after cardiac surgery should be detected early and treated in time. CRRT and peritoneal dialysis are safe, convenient and effective procedures, and may decrease the mortality rate in patients with ARF after cardiac surgery. DOI: 10.11855/j.issn.0557-7402.2015.04.13

  14. COPD predicts mortality in HF: the Norwegian Heart Failure Registry.

    Science.gov (United States)

    De Blois, Jonathan; Simard, Serge; Atar, Dan; Agewall, Stefan

    2010-03-01

    Chronic obstructive pulmonary disease (COPD) and chronic heart failure (HF) are common clinical conditions that share tobacco as a risk factor. Our aim was to evaluate the prognostic impact of COPD on HF patients. The Norwegian Heart Failure Registry was used. The study included 4132 HF patients (COPD, n = 699) from 22 hospitals (mean follow-up, 13.3 months). COPD patients were older, more often smokers and diabetics, less often on beta-blockers and had a higher heart rate. They were more often in New York Heart Association (NYHA) Class III or IV (COPD, 63%; no COPD, 51%), although left ventricular ejection fraction (LVEF) distribution was similar. COPD independently predicted death (adjusted hazard ratio [HR], 1.188; 95% CI: 1.015 to 1.391; P = 0.03) along with age, creatinine, NYHA Class III/IV (HR, 1.464; 95% CI: 1.286 to 1.667) and diabetes. beta-blockers at baseline were associated with improved survival in patients with LVEF < or =40% independently of COPD. COPD is associated with a poorer survival in HF patients. COPD patients are overrated in terms of NYHA class in comparison with patients with similar LVEF. Nonetheless, NYHA class remains the strongest predictor of death in these patients. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  15. Use of the total motile sperm count to predict total fertilization failure in in vitro fertilization

    NARCIS (Netherlands)

    Repping, Sjoerd; van Weert, Janne-Meije; Mol, Ben W. J.; de Vries, Jan W. A.; van der Veen, Fulco

    2002-01-01

    Objective: To evaluate the capacity of baseline characteristics and total motile sperm count (TMC) to predict total fertilization failure (TIFF) in patients undergoing IVF. Design: Retrospective cohort study. Setting: University hospital. Patient(s): Eight hundred ninety-two couples with a total of

  16. Development and validation of multivariable models to predict mortality and hospitalization in patients with heart failure

    NARCIS (Netherlands)

    Voors, Adriaan A.; Ouwerkerk, Wouter; Zannad, Faiez; van Veldhuisen, Dirk J.; Samani, Nilesh J.; Ponikowski, Piotr; Ng, Leong L.; Metra, Marco; ter Maaten, Jozine M.; Lang, Chim C.; Hillege, Hans L.; van der Harst, Pim; Filippatos, Gerasimos; Dickstein, Kenneth; Cleland, John G.; Anker, Stefan D.; Zwinderman, Aeilko H.

    Introduction From a prospective multicentre multicountry clinical trial, we developed and validated risk models to predict prospective all-cause mortality and hospitalizations because of heart failure (HF) in patients with HF. Methods and results BIOSTAT-CHF is a research programme designed to

  17. Development and validation of multivariable models to predict mortality and hospitalization in patients with heart failure

    NARCIS (Netherlands)

    Voors, Adriaan A.; Ouwerkerk, Wouter; Zannad, Faiez; van Veldhuisen, Dirk J.; Samani, Nilesh J.; Ponikowski, Piotr; Ng, Leong L.; Metra, Marco; ter Maaten, Jozine M.; Lang, Chim C.; Hillege, Hans L.; van der Harst, Pim; Filippatos, Gerasimos; Dickstein, Kenneth; Cleland, John G.; Anker, Stefan D.; Zwinderman, Aeilko H.

    2017-01-01

    Introduction From a prospective multicentre multicountry clinical trial, we developed and validated risk models to predict prospective all-cause mortality and hospitalizations because of heart failure (HF) in patients with HF. Methods and results BIOSTAT-CHF is a research programme designed to

  18. Health Literacy and Global Cognitive Function Predict E-Mail but Not Internet Use in Heart Failure Patients

    Directory of Open Access Journals (Sweden)

    Jared P. Schprechman

    2013-01-01

    Full Text Available Background. The internet offers a potential for improving patient knowledge, and e-mail may be used in patient communication with providers. However, barriers to internet and e-mail use, such as low health literacy and cognitive impairment, may prevent patients from using technological resources. Purpose. We investigated whether health literacy, heart failure knowledge, and cognitive function were related to internet and e-mail use in older adults with heart failure (HF. Methods. Older adults (N=119 with heart failure (69.84±9.09 years completed measures of health literacy, heart failure knowledge, cognitive functioning, and internet use in a cross-sectional study. Results. Internet and e-mail use were reported in 78.2% and 71.4% of this sample of patients with HF, respectively. Controlling for age and education, logistic regression analyses indicated that higher health literacy predicted e-mail (P<.05 but not internet use. Global cognitive function predicted e-mail (P<.05 but not internet use. Only 45% used the Internet to obtain information on HF and internet use was not associated with greater HF knowledge. Conclusions. The majority of HF patients use the internet and e-mail, but poor health literacy and cognitive impairment may prevent some patients from accessing these resources. Future studies that examine specific internet and email interventions to increase HF knowledge are needed.

  19. Immediate postoperative tracheal extubation in a liver transplant recipient with encephalopathy and the Mayo end-stage liver disease score of 41: A CARE-compliant case report revealed meaningful challenge in recovery after surgery (ERAS) for liver transplantation.

    Science.gov (United States)

    Li, Jianbo; Wang, Chengdi; Chen, Nan; Song, Jiulin; Sun, Yan; Yao, Qin; Yan, Lunan; Yang, Jiayin

    2017-11-01

    Immediate postoperative tracheal extubation (IPTE) is one of the most important subject in recovery after surgery (ERAS) for liver transplantation. However, the criteria for IPTE is not uniform at present. We reported a successful IPTE in a liver transplant recipient with encephalopathy and a high Mayo end-stage liver disease (MELD) score of 41, which beyond the so-called criteria reported in the literature. The patient was 48-year-old man, admitted in September 2016 for end-stage liver cirrhosis secondary to hepatitis B. End-stage liver cirrhosis secondary to hepatitis B with encephalopathy and a high MELD score of 41. He was involved in our ERAS project and was extubated at the end of the liver transplantation in the operating room. As a result, the patient was not reintubated and had an excellent postoperative recovery, staying in intensive care unit (ICU) for just 2 days and discharged home on day 10. We believed IPTE in liver transplant recipients with severe liver dysfunction is a meaningful challenge in ERAS for liver transplantation. Our case and literature review suggest 3 things: IPTE in liver transplantation is generally feasible and safe; the encephalopathy or high MELD score should not be the only limiting factor; and a more systematic predicting system for IPTE in liver transplantation should be addressed in future studies. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

  20. A risk score for predicting 30-day mortality in heart failure patients undergoing non-cardiac surgery

    DEFF Research Database (Denmark)

    Andersson, Charlotte; Gislason, Gunnar H; Hlatky, Mark A

    2014-01-01

    BACKGROUND: Heart failure is an established risk factor for poor outcomes in patients undergoing non-cardiac surgery, yet risk stratification remains a clinical challenge. We developed an index for 30-day mortality risk prediction in this particular group. METHODS AND RESULTS: All individuals...... with heart failure undergoing non-cardiac surgery between October 23 2004 and October 31 2011 were included from Danish administrative registers (n = 16 827). In total, 1787 (10.6%) died within 30 days. In a simple risk score based on the variables from the revised cardiac risk index, plus age, gender, acute...... by bootstrapping (1000 re-samples) provided c-statistic of 0.79. A more complex risk score based on stepwise logistic regression including 24 variables at P heart failure, this simple...

  1. Impact of the Occlusion Duration on the Performance of J-CTO Score in Predicting Failure of Percutaneous Coronary Intervention for Chronic Total Occlusion.

    Science.gov (United States)

    de Castro-Filho, Antonio; Lamas, Edgar Stroppa; Meneguz-Moreno, Rafael A; Staico, Rodolfo; Siqueira, Dimytri; Costa, Ricardo A; Braga, Sergio N; Costa, J Ribamar; Chamié, Daniel; Abizaid, Alexandre

    2017-06-01

    The present study examined the association between Multicenter CTO Registry in Japan (J-CTO) score in predicting failure of percutaneous coronary intervention (PCI) correlating with the estimated duration of chronic total occlusion (CTO). The J-CTO score does not incorporate estimated duration of the occlusion. This was an observational retrospective study that involved all consecutive procedures performed at a single tertiary-care cardiology center between January 2009 and December 2014. A total of 174 patients, median age 59.5 years (interquartile range [IQR], 53-65 years), undergoing CTO-PCI were included. The median estimated occlusion duration was 7.5 months (IQR, 4.0-12.0 months). The lesions were classified as easy (score = 0), intermediate (score = 1), difficult (score = 2), and very difficult (score ≥3) in 51.1%, 33.9%, 9.2%, and 5.7% of the patients, respectively. Failure rate significantly increased with higher J-CTO score (7.9%, 20.3%, 50.0%, and 70.0% in groups with J-CTO scores of 0, 1, 2, and ≥3, respectively; PJ-CTO score predicted failure of CTO-PCI independently of the estimated occlusion duration (P=.24). Areas under receiver-operating characteristic curves were computed and it was observed that for each occlusion time period, the discriminatory capacity of the J-CTO score in predicting CTO-PCI failure was good, with a C-statistic >0.70. The estimated duration of occlusion had no influence on the J-CTO score performance in predicting failure of PCI in CTO lesions. The probability of failure was mainly determined by grade of lesion complexity.

  2. Length of Barrett's segment predicts failure of eradication in radiofrequency ablation for Barrett's esophagus: a retrospective cohort study.

    Science.gov (United States)

    Luckett, Tyler; Allamneni, Chaitanya; Cowley, Kevin; Eick, John; Gullick, Allison; Peter, Shajan

    2018-05-21

    We aim to investigate factors that may contribute to failure of eradication of dysplastic Barrett's Esophagus among patients undergoing radiofrequency ablation treatment. A retrospective review of patients undergoing radiofrequency ablation for treatment of Barrett's Esophagus was performed. Data analyzed included patient demographics, medical history, length of Barrett's Esophagus, number of radiofrequency ablation sessions, and histopathology. Subsets of patients achieving complete eradication were compared with those not achieving complete eradication. A total of 107 patients underwent radiofrequency ablation for Barrett's Esophagus, the majority white, overweight, and male. Before treatment, 63 patients had low-grade dysplasia, and 44 patients had high-grade dysplasia or carcinoma. Complete eradication was achieved in a majority of patients (57% for metaplasia, and 76.6% for dysplasia). Failure of eradication occurred in 15.7% of patients. The median number of radiofrequency ablation treatments in patients achieving complete eradication was 3 sessions, compared to 4 sessions for failure of eradication (p = 0.06). Barrett's esophagus length of more than 5 cm was predictive of failure of eradication (p Radiofrequency ablation for dysplastic Barrett's Esophagus is a proven and effective treatment modality, associated with a high rate of complete eradication. Our rates of eradication from a center starting an ablation program are comparable to previously published studies. Length of Barrett's segment > 5 cm was found to be predictive of failure of eradication in patients undergoing radiofrequency ablation.

  3. Failure analysis for ultrasound machines in a radiology department after implementation of predictive maintenance method

    Directory of Open Access Journals (Sweden)

    Greg Chu

    2018-01-01

    Full Text Available Objective: The objective of the study was to perform quantitative failure and fault analysis to the diagnostic ultrasound (US scanners in a radiology department after the implementation of the predictive maintenance (PdM method; to study the reduction trend of machine failure; to understand machine operating parameters affecting the failure; to further optimize the method to maximize the machine clinically service time. Materials and Methods: The PdM method has been implemented to the 5 US machines since 2013. Log books were used to record machine failures and their root causes together with the time spent on repair, all of which were retrieved, categorized, and analyzed for the period between 2013 and 2016. Results: There were a total of 108 cases of failure occurred in these 5 US machines during the 4-year study period. The average number of failure per month for all these machines was 2.4. Failure analysis showed that there were 33 cases (30.5% due to software, 44 cases (40.7% due to hardware, and 31 cases (28.7% due to US probe. There was a statistically significant negative correlation between the time spent on regular quality assurance (QA by hospital physicists with the time spent on faulty parts replacement over the study period (P = 0.007. However, there was no statistically significant correlation between regular QA time and total yearly breakdown case (P = 0.12, although there has been a decreasing trend observed in the yearly total breakdown. Conclusion: There has been a significant improvement on the machine failure of US machines attributed to the concerted effort of sonographers and physicists in our department to practice the PdM method, in that system component repair time has been reduced, and a decreasing trend in the number of system breakdown has been observed.

  4. Validation of the Seattle Heart Failure Model (SHFM) in Heart Failure Population

    International Nuclear Information System (INIS)

    Hussain, S.; Kayani, A.M.; Munir, R.

    2014-01-01

    Objective: To determine the effectiveness of Seattle Heart Failure Model (SHFM) in a Pakistani systolic heart failure cohort in predicting mortality in this population. Study Design: Cohort study. Place and Duration of Study: The Armed Forces Institute of Cardiology - National Institute of Heart Diseases, Rawalpindi, from March 2011 to March 2012. Methodology: One hundred and eighteen patients with heart failure (HF) from the registry were followed for one year. Their 1-year mortality was calculated using the SHFM software on their enrollment into the registry. After 1-year predicted 1-year mortality was compared with the actual 1-year mortality of these patients. Results: The mean age was 41.6 +- 14.9 years (16 - 78 years). There were 73.7% males and 26.3% females. One hundred and fifteen patients were in NYHA class III or IV. Mean ejection fraction in these patients was 23 +- 9.3%. Mean brain natriuretic peptide levels were 1230 A+- 1214 pg/mL. Sensitivity of the model was 89.3% with 71.1% specificity, 49% positive predictive value and 95.5% negative predictive value. The accuracy of the model was 75.4%. In Roc analysis, AUC for the SHFM was 0.802 (p<0.001). conclusion: SHFM was found to be reliable in predicting one year mortality among patients with heart failure in the pakistan patients. (author)

  5. Sugammadex rescue following prolonged rocuronium neuromuscular blockade with ‘recurarisation’ in a patient with severe renal failure

    Science.gov (United States)

    Lobaz, Steven; Sammut, Mario; Damodaran, Anand

    2013-01-01

    We describe our experience of a 71-year-old patient with severe renal failure, who exhibited an unusually prolonged rocuronium-induced neuromuscular blockade (>4 h) and apparent recurarisation, following emergency rapid sequence induction (RSI). At the end of operation, 45 min post induction, train-of-four (TOF) testing had been 4/4 prior to wake up. No respiratory effort was seen 150 min postinduction, despite further neostigmine/glycopyrrolate and repeat TOF 4/4. The patient was resedated and transferred to the intensive care unit (ICU). At 180 min postinduction, fade was evident on TOF, suggestive of rocuronium reblockade. At 285 min, the patient was extubated safely following sugammadex administration and discharged uneventfully from the ICU. An important lesson to recognise is the potential for extremely prolonged neuromuscular blockade following rocuronium in patients with severe renal failure, particularly when using the higher doses (1.2 mg/kg) required for RSI, and that TOF in such cases may not be reliable in detecting residual blockade. PMID:23396837

  6. Prediction of posthepatectomy liver failure using transient elastography in patients with hepatitis B related hepatocellular carcinoma.

    Science.gov (United States)

    Lei, Jie-Wen; Ji, Xiao-Yu; Hong, Jun-Feng; Li, Wan-Bin; Chen, Yan; Pan, Yan; Guo, Jia

    2017-12-29

    It is essential to accurately predict Postoperative liver failure (PHLF) which is a life-threatening complication. Liver hardness measurement (LSM) is widely used in non-invasive assessment of liver fibrosis. The aims of this study were to explore the application of preoperative liver stiffness measurements (LSM) by transient elastography in predicting postoperative liver failure (PHLF) in patients with hepatitis B related hepatocellular carcinoma. The study included 247 consecutive patients with hepatitis B related hepatocellular carcinoma who underwent hepatectomy between May 2015 and September 2015. Detailed preoperative examinations including LSM were performed before hepatectomy. The endpoint was the development of PHLF. All of the patients had chronic hepatitis B defined as the presence of hepatitis B surface antigen (HBsAg) for more than 6 months and 76 (30.8%) had cirrhosis. PHLF occurred in 37 (14.98%) patients. Preoperative LSM (odds ratio, OR, 1.21; 95% confidence interval, 95% CI: 1.13-1.29; P hepatocellular carcinoma.

  7. [The Predictive Factors of Stent Failure in the Treatment of Malignant Extrinsc Ureteral Obstruction Using Internal Ureteral Stents].

    Science.gov (United States)

    Matsuura, Hiroshi; Arase, Shigeki; Hori, Yasuhide; Tochigi, Hiromi

    2017-12-01

    In this study, we retrospectively reviewed the experiences at our single institute in the treatment of malignant extrinsic ureteral obstruction (MUO) using ureteral stents to investigate the clinical outcomes and the predictive factors of stent failure. In 52 ureters of 38 patients who had radiologically significant hydronephrosis due to MUO, internal ureteral stents (The BARD(R) INLAY(TM) ureteral stent set) were inserted. The median follow-up interval after the initial stent insertion was 124.5 days (4-1,120). Stent failure occurred in 8 ureters (15.4%) of the 7 patients. The median interval from the first stent insertion to stent failure was 88 days (1-468). A Cox regression multivariate analysis showed that the significant predictors of stent failure were bladder invasion. Based on the possibility of stent failure, the adaptation of the internal ureteral stent placement should be considered especially in a patient with MUO combined with bladder invasion.

  8. Prediction of dynamic expected time to system failure

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Deog Yeon; Lee, Chong Chul [Korea Nuclear Fuel Co., Ltd., Taejon (Korea, Republic of)

    1998-12-31

    The mean time to failure (MTTF) expressing the mean value of the system life is a measure of system effectiveness. To estimate the remaining life of component and/or system, the dynamic mean time to failure concept is suggested. It is the time-dependent property depending on the status of components. The Kalman filter is used to estimate the reliability of components using the on-line information (directly measured sensor output or device-specific diagnostics in the intelligent sensor) in form of the numerical value (state factor). This factor considers the persistency of the fault condition and confidence level in measurement. If there is a complex system with many components, each calculated reliability`s of components are combined, which results in the dynamic MTTF of system. The illustrative examples are discussed. The results show that the dynamic MTTF can well express the component and system failure behaviour whether any kinds of failure are occurred or not. 9 refs., 6 figs. (Author)

  9. Prediction of dynamic expected time to system failure

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Deog Yeon; Lee, Chong Chul [Korea Nuclear Fuel Co., Ltd., Taejon (Korea, Republic of)

    1997-12-31

    The mean time to failure (MTTF) expressing the mean value of the system life is a measure of system effectiveness. To estimate the remaining life of component and/or system, the dynamic mean time to failure concept is suggested. It is the time-dependent property depending on the status of components. The Kalman filter is used to estimate the reliability of components using the on-line information (directly measured sensor output or device-specific diagnostics in the intelligent sensor) in form of the numerical value (state factor). This factor considers the persistency of the fault condition and confidence level in measurement. If there is a complex system with many components, each calculated reliability`s of components are combined, which results in the dynamic MTTF of system. The illustrative examples are discussed. The results show that the dynamic MTTF can well express the component and system failure behaviour whether any kinds of failure are occurred or not. 9 refs., 6 figs. (Author)

  10. Ductile shear failure or plug failure of spot welds modelled by modified Gurson model

    DEFF Research Database (Denmark)

    Nielsen, Kim Lau; Tvergaard, Viggo

    2010-01-01

    For resistance spot welded shear-lab specimens, interfacial failure under ductile shearing or ductile plug failure are analyzed numerically, using a shear modified Gurson model. The interfacial shear failure occurs under very low stress triaxiality, where the original Gurson model would predict...

  11. Predictive modelling of fatigue failure in concentrated lubricated contacts.

    Science.gov (United States)

    Evans, H P; Snidle, R W; Sharif, K J; Bryant, M J

    2012-01-01

    Reducing frictional losses in response to the energy agenda will require use of less viscous lubricants causing hydrodynamically-lubricated bearings to operate with thinner films leading to "mixed lubrication" conditions in which a degree of direct interaction occurs between surfaces protected only by boundary tribofilms. The paper considers the consequences of thinner films and mixed lubrication for concentrated contacts such as those occurring between the teeth of power transmission gears and in rolling element bearings. Surface fatigue in gears remains a serious problem in demanding applications, and its solution will become more pressing with the tendency towards thinner oils. The particular form of failure examined here is micropitting, which is identified as a fatigue phenomenon occurring at the scale of the surface roughness asperities. It has emerged recently as a systemic difficulty in the operation of large scale wind turbines where it occurs in both power transmission gears and their support bearings. Predictive physical modelling of these contacts requires a transient mixed lubrication analysis for conditions in which the predicted lubricant film thickness is of the same order or significantly less than the height of surface roughness features. Numerical solvers have therefore been developed which are able to deal with situations in which transient solid contacts occur between surface asperity features under realistic engineering conditions. Results of the analysis, which reveal the detailed time-varying behaviour of pressure and film clearance, have been used to predict fatigue and damage accumulation at the scale of surface asperity features with the aim of improving understanding of the micropitting phenomenon. The possible consequences on fatigue of residual stress fields resulting from plastic deformation of surface asperities is also considered.

  12. A Novel Risk Stratification to Predict Local-Regional Failures in Urothelial Carcinoma of the Bladder After Radical Cystectomy

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Brian C. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Guzzo, Thomas J. [Department of Urology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); He Jiwei [Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Keefe, Stephen M. [Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Tucker, Kai; Bekelman, Justin E. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Hwang, Wei-Ting [Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Vaughn, David J. [Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Malkowicz, S. Bruce [Department of Urology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Christodouleas, John P., E-mail: christojo@uphs.upenn.edu [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States)

    2013-01-01

    Purpose: Local-regional failures (LF) following radical cystectomy (RC) plus pelvic lymph node dissection (PLND) with or without chemotherapy for invasive urothelial bladder carcinoma are more common than previously reported. Adjuvant radiation therapy (RT) could reduce LF but currently has no defined role because of previously reported morbidity. Modern techniques with improved normal tissue sparing have rekindled interest in RT. We assessed the risk of LF and determined those factors that predict recurrence to facilitate patient selection for future adjuvant RT trials. Methods and Materials: From 1990-2008, 442 patients with urothelial bladder carcinoma at University of Pennsylvania were prospectively followed after RC plus PLND with or without chemotherapy with routine pelvic computed tomography (CT) or magnetic resonance imaging (MRI). One hundred thirty (29%) patients received chemotherapy. LF was any pelvic failure detected before or within 3 months of distant failure. Competing risk analyses identified factors predicting increased LF risk. Results: On univariate analysis, pathologic stage {>=}pT3, <10 nodes removed, positive margins, positive nodes, hydronephrosis, lymphovascular invasion, and mixed histology significantly predicted LF; node density was marginally predictive, but use of chemotherapy, number of positive nodes, type of surgical diversion, age, gender, race, smoking history, and body mass index were not. On multivariate analysis, only stage {>=}pT3 and <10 nodes removed were significant independent LF predictors with hazard ratios of 3.17 and 2.37, respectively (P<.01). Analysis identified 3 patient subgroups with significantly different LF risks: low-risk ({<=}pT2), intermediate-risk ({>=}pT3 and {>=}10 nodes removed), and high-risk ({>=}pT3 and <10 nodes) with 5-year LF rates of 8%, 23%, and 42%, respectively (P<.01). Conclusions: This series using routine CT and MRI surveillance to detect LF confirms that such failures are relatively common

  13. A Novel Risk Stratification to Predict Local-Regional Failures in Urothelial Carcinoma of the Bladder After Radical Cystectomy

    International Nuclear Information System (INIS)

    Baumann, Brian C.; Guzzo, Thomas J.; He Jiwei; Keefe, Stephen M.; Tucker, Kai; Bekelman, Justin E.; Hwang, Wei-Ting; Vaughn, David J.; Malkowicz, S. Bruce; Christodouleas, John P.

    2013-01-01

    Purpose: Local-regional failures (LF) following radical cystectomy (RC) plus pelvic lymph node dissection (PLND) with or without chemotherapy for invasive urothelial bladder carcinoma are more common than previously reported. Adjuvant radiation therapy (RT) could reduce LF but currently has no defined role because of previously reported morbidity. Modern techniques with improved normal tissue sparing have rekindled interest in RT. We assessed the risk of LF and determined those factors that predict recurrence to facilitate patient selection for future adjuvant RT trials. Methods and Materials: From 1990-2008, 442 patients with urothelial bladder carcinoma at University of Pennsylvania were prospectively followed after RC plus PLND with or without chemotherapy with routine pelvic computed tomography (CT) or magnetic resonance imaging (MRI). One hundred thirty (29%) patients received chemotherapy. LF was any pelvic failure detected before or within 3 months of distant failure. Competing risk analyses identified factors predicting increased LF risk. Results: On univariate analysis, pathologic stage ≥pT3, <10 nodes removed, positive margins, positive nodes, hydronephrosis, lymphovascular invasion, and mixed histology significantly predicted LF; node density was marginally predictive, but use of chemotherapy, number of positive nodes, type of surgical diversion, age, gender, race, smoking history, and body mass index were not. On multivariate analysis, only stage ≥pT3 and <10 nodes removed were significant independent LF predictors with hazard ratios of 3.17 and 2.37, respectively (P<.01). Analysis identified 3 patient subgroups with significantly different LF risks: low-risk (≤pT2), intermediate-risk (≥pT3 and ≥10 nodes removed), and high-risk (≥pT3 and <10 nodes) with 5-year LF rates of 8%, 23%, and 42%, respectively (P<.01). Conclusions: This series using routine CT and MRI surveillance to detect LF confirms that such failures are relatively common in

  14. Stress evaluation of baffle former bolt for IASCC failure prediction

    International Nuclear Information System (INIS)

    Matsubara, T.; Tsutsui, T.; Kamei, Y.; Kitsu, M.

    2011-01-01

    Baffle structure in PWRs Reactor is quite important assembly for the core safety, and Baffle Former Bolts (BFBs) are fastener members for maintaining Baffle structure. It has been reported worldwide that some of BFBs were cracked due to IASCC (Irradiation Assisted Stress Corrosion Cracking) because BFBs are located at core region under severe environments, high neutron flux, high temperature and high stress. According to the material studies of IASCC on austenitic stainless steel, a crack initiation of IASCC is strongly related with the stress and the neutron fluence. For this reason, it is very important for IASCC failure prediction to simulate the stress of BFBs. However, the stress of BFBs are considered to be influenced by several factors and to be changed complexly as operational time increases, by irradiation creep of Bolt itself, swelling of Baffle structure, and so on. Therefore, it is difficult to estimate the stress histories of BFBs (Bolt stress as a function of operational time) precisely. Then, the author has developed the calculation method of the stress histories of BFBs considering irradiation effects (swelling and irradiation creep). In this method, the stress histories of BFBs are calculated by combining two kinds of FE models, Global model (modeled whole Baffle structure which consists of Baffle plates, Former plates and Core Barrel) and Local model (modeled around BFB finely). The whole Baffle structure deformation changes as a function of heat, swelling and irradiated creep are calculated by Global model, and the stress histories of BFBs are calculated by Local model using the outputs (deformations on driving nodes) of Global model. In the FE analysis of Local model, the stress of BFBs are calculated considering irradiation effects and elastic-plastic characteristics depending on neutron fluence, so this method enables to calculate precisely the stress of extreme small area of BFBs surface. This paper shows the outline of the calculation method

  15. Application Of Data Mining Techniques For Student Success And Failure Prediction The Case Of DebreMarkos University

    OpenAIRE

    Muluken Alemu Yehuala

    2015-01-01

    Abstract This research work has investigated the potential applicability of data mining technology to predict student success and failure cases on University students datasets. CRISP-DM Cross Industry Standard Process for Data mining is a data mining methodology to be used by the research. Classification and prediction data mining functionalities are used to extract hidden patterns from students data. These patterns can be seen in relation to different variables in the students records. The ...

  16. Implicit and Explicit Attitudes Predict Smoking Cessation: Moderating Effects of Experienced Failure to Control Smoking and Plans to Quit

    OpenAIRE

    Chassin, Laurie; Presson, Clark C.; Sherman, Steven J.; Seo, Dong-Chul; Macy, Jon

    2010-01-01

    The current study tested implicit and explicit attitudes as prospective predictors of smoking cessation in a Midwestern community sample of smokers. Results showed that the effects of attitudes significantly varied with levels of experienced failure to control smoking and plans to quit. Explicit attitudes significantly predicted later cessation among those with low (but not high or average) levels of experienced failure to control smoking. Conversely, however, implicit attitudes significantly...

  17. Deformation, Failure, and Fatigue Life of SiC/Ti-15-3 Laminates Accurately Predicted by MAC/GMC

    Science.gov (United States)

    Bednarcyk, Brett A.; Arnold, Steven M.

    2002-01-01

    NASA Glenn Research Center's Micromechanics Analysis Code with Generalized Method of Cells (MAC/GMC) (ref.1) has been extended to enable fully coupled macro-micro deformation, failure, and fatigue life predictions for advanced metal matrix, ceramic matrix, and polymer matrix composites. Because of the multiaxial nature of the code's underlying micromechanics model, GMC--which allows the incorporation of complex local inelastic constitutive models--MAC/GMC finds its most important application in metal matrix composites, like the SiC/Ti-15-3 composite examined here. Furthermore, since GMC predicts the microscale fields within each constituent of the composite material, submodels for local effects such as fiber breakage, interfacial debonding, and matrix fatigue damage can and have been built into MAC/GMC. The present application of MAC/GMC highlights the combination of these features, which has enabled the accurate modeling of the deformation, failure, and life of titanium matrix composites.

  18. The role of microstructure and phase distribution in the failure mechanisms and life prediction model for PSZ coatings

    Science.gov (United States)

    Sisson, R. D., Jr.; Sone, Ichiro; Biederman, R. R.

    1985-01-01

    Partially Stabilized Zirconia (PSZ) may become widely used for Thermal Barrier Coatings (TBC). Failure of these coatings can occur due to thermal fatigue in oxidizing atmospheres. The failure is due to the strains that develop due to thermal gradients, differences in thermal expansion coefficients, and oxidation of the bond coating. The role of microstructure and the cubic, tetragonal, and monoclinic phase distribution in the strain development and subsequent failure will be discussed. An X-ray diffraction technique for accurate determination of the fraction of each phase in PSZ will be applied to understanding the phase transformations and strain development. These results will be discussed in terms of developing a model for life prediction in PSZ coatings during thermal cycling.

  19. miRNA signatures can predict acute liver failure in hepatitis E infected pregnant females

    Directory of Open Access Journals (Sweden)

    Nirupma Trehanpati

    2017-04-01

    Full Text Available Background: Acute viral hepatitis E (AVH-E can often result in acute liver failure (ALF during pregnancy. microRNAs serve as mediators in drug induced liver failure. We investigated their role as a biomarker in predicting ALF due to HEV (ALF-E. Methods: We performed next generation sequencing and subsequent validation studies in PBMCs of pregnant (P self limiting AVH-E, ALF due to HEV (ALF-E and compared with AVH-E in non-pregnant (NP females and healthy controls. Findings: Eleven microRNAs were significantly expressed in response to HEV infection; importantly, miR- 431, 654, 1468 and 4435, were distinctly expressed in pregnant self-limiting AVH-E and healthy females (p = 0.0005, but not in ALF-E. Sixteen exclusive microRNAs differentiated ALF-E from self limiting AVH-E in pregnant females. miR-450b which affects cellular proliferation and metabolic processes through RNF20 and SECB was predominanlty upregulated and correlated with poor outcome (ROC 0.958, p = 0.001. Interpretation: Our results reveal that a specific microRNA profile can predict fatality in ALF-E in pregnancy. These microRNAs could be exploited as prognostic biomarkers and help in the development of new therapeutic interventions. Keywords: Health sciences, Virology

  20. Success/Failure Prediction of Noninvasive Mechanical Ventilation in Intensive Care Units. Using Multiclassifiers and Feature Selection Methods.

    Science.gov (United States)

    Martín-González, Félix; González-Robledo, Javier; Sánchez-Hernández, Fernando; Moreno-García, María N

    2016-05-17

    This paper addresses the problem of decision-making in relation to the administration of noninvasive mechanical ventilation (NIMV) in intensive care units. Data mining methods were employed to find out the factors influencing the success/failure of NIMV and to predict its results in future patients. These artificial intelligence-based methods have not been applied in this field in spite of the good results obtained in other medical areas. Feature selection methods provided the most influential variables in the success/failure of NIMV, such as NIMV hours, PaCO2 at the start, PaO2 / FiO2 ratio at the start, hematocrit at the start or PaO2 / FiO2 ratio after two hours. These methods were also used in the preprocessing step with the aim of improving the results of the classifiers. The algorithms provided the best results when the dataset used as input was the one containing the attributes selected with the CFS method. Data mining methods can be successfully applied to determine the most influential factors in the success/failure of NIMV and also to predict NIMV results in future patients. The results provided by classifiers can be improved by preprocessing the data with feature selection techniques.

  1. Can baseline ultrasound results help to predict failure to achieve DAS28 remission after 1 year of tight control treatment in early RA patients?

    Science.gov (United States)

    Ten Cate, D F; Jacobs, J W G; Swen, W A A; Hazes, J M W; de Jager, M H; Basoski, N M; Haagsma, C J; Luime, J J; Gerards, A H

    2018-01-30

    At present, there are no prognostic parameters unequivocally predicting treatment failure in early rheumatoid arthritis (RA) patients. We investigated whether baseline ultrasonography (US) findings of joints, when added to baseline clinical, laboratory, and radiographical data, could improve prediction of failure to achieve Disease Activity Score assessing 28 joints (DAS28) remission (baseline. Clinical, laboratory, and radiographical parameters were recorded. Primary analysis was the prediction by logistic regression of the absence of DAS28 remission 12 months after diagnosis and start of therapy. Of 194 patients included, 174 were used for the analysis, with complete data available for 159. In a multivariate model with baseline DAS28 (odds ratio (OR) 1.6, 95% confidence interval (CI) 1.2-2.2), the presence of rheumatoid factor (OR 2.3, 95% CI 1.1-5.1), and type of monitoring strategy (OR 0.2, 95% CI 0.05-0.85), the addition of baseline US results for joints (OR 0.96, 95% CI 0.89-1.04) did not significantly improve the prediction of failure to achieve DAS28 remission (likelihood ratio test, 1.04; p = 0.31). In an early RA population, adding baseline ultrasonography of the hands, wrists, and feet to commonly available baseline characteristics did not improve prediction of failure to achieve DAS28 remission at 12 months. Clinicaltrials.gov, NCT01752309 . Registered on 19 December 2012.

  2. Evaluation of a Mapleson D CPAP system for weaning of mechanical ventilation in pediatric patients.

    Science.gov (United States)

    Palomero-Rodríguez, Miguel Angel; de Arteaga, Héctor Chozas; Báez, Yolanda Laporta; de Vicente Sánchez, Jesús; Carretero, Pascual Sanabria; Conde, Pilar Sánchez; Pérez Ferrer, Antonio

    2016-01-01

    Over the last years, we have used a flow-inflating bag circuit with a nasotracheal or nasopharyngeal tube as an interface to deliver effective CPAP support in infants ("Mapleson D CPAP system"). The primary goal of this study was to assess the usefulness of the "Mapleson D CPAP system" for weaning of mechanical ventilation (MV) in infants who received MV over 24 h. All infants who received MV for more than 24 h in the last year were enrolled in the study. Demographic data included age, gender, weight, and admission diagnosis. Heart rate, respiratory rate, blood pressure, and oxygen saturation were measured during MV, 2 h after the nasotracheal Mapleson D CPAP system and 2 h after extubation. Patients were classified into two groups: patients MV more than 48 h, and patients with MV fewer than 48 h. P CPAP system and 2 h after extubation and spontaneous ventilation with the nasopharyngeal Mapleson D CPAP system or with nasal prongs. The overall extubation failure rate was 26% (n = 13). Weight and age were significantly associated with extubation failure (P CPAP system, in our opinion, is a useful and safe alternative to more complex and expensive noninvasive CPAP and BiPAP weaning from MV in infants.

  3. Predicting success of high-flow nasal cannula in pneumonia patients with hypoxemic respiratory failure: The utility of the ROX index.

    Science.gov (United States)

    Roca, Oriol; Messika, Jonathan; Caralt, Berta; García-de-Acilu, Marina; Sztrymf, Benjamin; Ricard, Jean-Damien; Masclans, Joan R

    2016-10-01

    The purpose of the study is to describe early predictors and to develop a prediction tool that accurately identifies the need for mechanical ventilation (MV) in pneumonia patients with hypoxemic acute respiratory failure (ARF) treated with high-flow nasal cannula (HFNC). This is a 4-year prospective observational 2-center cohort study including patients with severe pneumonia treated with HFNC. High-flow nasal cannula failure was defined as need for MV. ROX index was defined as the ratio of pulse oximetry/fraction of inspired oxygen to respiratory rate. One hundred fifty-seven patients were included, of whom 44 (28.0%) eventually required MV (HFNC failure). After 12 hours of HFNC treatment, the ROX index demonstrated the best prediction accuracy (area under the receiver operating characteristic curve 0.74 [95% confidence interval, 0.64-0.84]; Pfailure in whom therapy can be continued after 12 hours. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. O uso do teste de escape do balonete como fator preditor de laringoespasmo The use of the cuff leak test as a factor to predict laryngospasm

    Directory of Open Access Journals (Sweden)

    Lucas Montano Paternostro Saback

    2008-03-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: O desmame da ventilação mecânica é um desafio na prática da unidade de terapia intensiva (UTI e está relacionado a diversas complicações. Uma dessas complicações relaciona-se ao laringoespasmo pós-extubação, evento que muitas vezes pode ser previsto através do teste de escape do balonete (TEB. O objetivo deste estudo foi demonstrar que o TEB é um método simples, confiável e de baixo custo para avaliar o grau de obstrução de via aérea superior em pacientes no processo de desmame da ventilação mecânica. CONTEÚDO: Foi realizada revisão sistemática da literatura através das bases de dados MedLine, SciElo e LILACS com publicações entre 1995 e 2007. Os artigos incluídos abordaram o uso do teste do balonete como índice preditivo para laringoespasmo e falha na extubação traqueal. Não fizeram parte estudos com animais e revisões bibliográficas. Procurou-se relacionar o TEB com tempo de ventilação mecânica, idade e grupos específicos de pacientes que se beneficiaram com a técnica. CONCUSÕES: O TEB pode ser considerado bom índice preditivo para identificar a presença de laringoespasmo pós-extubação, quando levadas em consideração as características da população estudada.BACKGROUND AND OBJECTIVES: Weaning patients from mechanical ventilation is a challenge in the intensive care unit (ICU practice and is related to some complications. One of these is the pos-extubation laryngospasm, an event that can be anticipated for the cuff leak test (CLT. The objective was demonstrate that the CLT is a simple, reliable and low costs method to available the presence of obstruction in high airway in patients under weaning ventilator. CONTENTS: It was made a systematic review in databases MedLine, SciElo and LILACS with articles from 1995 to 2007. The selected studies focused the use of the CLT to predict laryngospasm and extubation failure. It was excluded studies with animals and others

  5. Human Factors Predicting Failure and Success in Hospital Information System Implementations in Sub-Saharan Africa.

    Science.gov (United States)

    Verbeke, Frank; Karara, Gustave; Nyssen, Marc

    2015-01-01

    From 2007 through 2014, the authors participated in the implementation of open source hospital information systems (HIS) in 19 hospitals in Rwanda, Burundi, DR Congo, Congo-Brazzaville, Gabon, and Mali. Most of these implementations were successful, but some failed. At the end of a seven-year implementation effort, a number of risk factors, facilitators, and pragmatic approaches related to the deployment of HIS in Sub-Saharan health facilities have been identified. Many of the problems encountered during the HIS implementation process were not related to technical issues but human, cultural, and environmental factors. This study retrospectively evaluates the predictive value of 14 project failure factors and 15 success factors in HIS implementation in the Sub-Saharan region. Nine of the failure factors were strongly correlated with project failure, three were moderately correlated, and one weakly correlated. Regression analysis also confirms that eight factors were strongly correlated with project success, four moderately correlated, and two weakly correlated. The study results may help estimate the expedience of future HIS projects.

  6. Failure Predictions of Out-of-Autoclave Sandwich Joints with Delaminations Under Flexure Loads

    Science.gov (United States)

    Nordendale, Nikolas A.; Goyal, Vinay K.; Lundgren, Eric C.; Patel, Dhruv N.; Farrokh, Babak; Jones, Justin; Fischetti, Grace; Segal, Kenneth N.

    2015-01-01

    An analysis and a test program was conducted to investigate the damage tolerance of composite sandwich joints. The joints contained a single circular delamination between the face-sheet and the doubler. The coupons were fabricated through out-of-autoclave (OOA) processes, a technology NASA is investigating for joining large composite sections. The four-point bend flexure test was used to induce compression loading into the side of the joint where the delamination was placed. The compression side was chosen since it tends to be one of the most critical loads in launch vehicles. Autoclave cure was used to manufacture the composite sandwich sections, while the doubler was co-bonded onto the sandwich face-sheet using an OOA process after sandwich panels were cured. A building block approach was adopted to characterize the mechanical properties of the joint material, including the fracture toughness between the doubler and face-sheet. Twelve four-point-bend samples were tested, six in the sandwich core ribbon orientation and six in sandwich core cross-ribbon direction. Analysis predicted failure initiation and propagation at the pre-delaminated location, consistent with experimental observations. A building block approach using fracture analyses methods predicted failure loads in close agreement with tests. This investigation demonstrated a small strength reduction due to a flaw of significant size compared to the width of the sample. Therefore, concerns of bonding an OOA material to an in-autoclave material was mitigated for the geometries, materials, and load configurations considered.

  7. How to Predict Oral Rehydration Failure in Children With Gastroenteritis.

    Science.gov (United States)

    Geurts, Dorien; Steyerberg, Ewout W; Moll, Henriëtte; Oostenbrink, Rianne

    2017-11-01

    Oral rehydration is the standard in most current guidelines for young children with acute gastroenteritis (AGE). Failure of oral rehydration can complicate the disease course, leading to morbidity due to severe dehydration. We aimed to identify prognostic factors of oral rehydration failure in children with AGE. A prospective, observational study was performed at the Emergency department, Erasmus Medical Centre, Rotterdam, The Netherlands, 2010-2012, including 802 previously healthy children, ages 1 month to 5 years with AGE. Failure of oral rehydration was defined by secondary rehydration by a nasogastric tube, or hospitalization or revisit for dehydration within 72 hours after initial emergency department visit. We observed 167 (21%) failures of oral rehydration in a population of 802 children with AGE (median 1.03 years old, interquartile range 0.4-2.1; 60% boys). In multivariate logistic regression analysis, independent predictors for failure of oral rehydration were a higher Manchester Triage System urgency level, abnormal capillary refill time, and a higher clinical dehydration scale score. Early recognition of young children with AGE at risk of failure of oral rehydration therapy is important, as emphasized by the 21% therapy failure in our population. Associated with oral rehydration failure are higher Manchester Triage System urgency level, abnormal capillary refill time, and a higher clinical dehydration scale score.

  8. Sudden cardiac death and pump failure death prediction in chronic heart failure by combining ECG and clinical markers in an integrated risk model

    Science.gov (United States)

    Orini, Michele; Mincholé, Ana; Monasterio, Violeta; Cygankiewicz, Iwona; Bayés de Luna, Antonio; Martínez, Juan Pablo

    2017-01-01

    Background Sudden cardiac death (SCD) and pump failure death (PFD) are common endpoints in chronic heart failure (CHF) patients, but prevention strategies are different. Currently used tools to specifically predict these endpoints are limited. We developed risk models to specifically assess SCD and PFD risk in CHF by combining ECG markers and clinical variables. Methods The relation of clinical and ECG markers with SCD and PFD risk was assessed in 597 patients enrolled in the MUSIC (MUerte Súbita en Insuficiencia Cardiaca) study. ECG indices included: turbulence slope (TS), reflecting autonomic dysfunction; T-wave alternans (TWA), reflecting ventricular repolarization instability; and T-peak-to-end restitution (ΔαTpe) and T-wave morphology restitution (TMR), both reflecting changes in dispersion of repolarization due to heart rate changes. Standard clinical indices were also included. Results The indices with the greatest SCD prognostic impact were gender, New York Heart Association (NYHA) class, left ventricular ejection fraction, TWA, ΔαTpe and TMR. For PFD, the indices were diabetes, NYHA class, ΔαTpe and TS. Using a model with only clinical variables, the hazard ratios (HRs) for SCD and PFD for patients in the high-risk group (fifth quintile of risk score) with respect to patients in the low-risk group (first and second quintiles of risk score) were both greater than 4. HRs for SCD and PFD increased to 9 and 11 when using a model including only ECG markers, and to 14 and 13, when combining clinical and ECG markers. Conclusion The inclusion of ECG markers capturing complementary pro-arrhythmic and pump failure mechanisms into risk models based only on standard clinical variables substantially improves prediction of SCD and PFD in CHF patients. PMID:29020031

  9. Using methods from the data mining and machine learning literature for disease classification and prediction: A case study examining classification of heart failure sub-types

    Science.gov (United States)

    Austin, Peter C.; Tu, Jack V.; Ho, Jennifer E.; Levy, Daniel; Lee, Douglas S.

    2014-01-01

    Objective Physicians classify patients into those with or without a specific disease. Furthermore, there is often interest in classifying patients according to disease etiology or subtype. Classification trees are frequently used to classify patients according to the presence or absence of a disease. However, classification trees can suffer from limited accuracy. In the data-mining and machine learning literature, alternate classification schemes have been developed. These include bootstrap aggregation (bagging), boosting, random forests, and support vector machines. Study design and Setting We compared the performance of these classification methods with those of conventional classification trees to classify patients with heart failure according to the following sub-types: heart failure with preserved ejection fraction (HFPEF) vs. heart failure with reduced ejection fraction (HFREF). We also compared the ability of these methods to predict the probability of the presence of HFPEF with that of conventional logistic regression. Results We found that modern, flexible tree-based methods from the data mining literature offer substantial improvement in prediction and classification of heart failure sub-type compared to conventional classification and regression trees. However, conventional logistic regression had superior performance for predicting the probability of the presence of HFPEF compared to the methods proposed in the data mining literature. Conclusion The use of tree-based methods offers superior performance over conventional classification and regression trees for predicting and classifying heart failure subtypes in a population-based sample of patients from Ontario. However, these methods do not offer substantial improvements over logistic regression for predicting the presence of HFPEF. PMID:23384592

  10. A Retrospective Study of Success, Failure, and Time Needed to Perform Awake Intubation.

    Science.gov (United States)

    Joseph, Thomas T; Gal, Jonathan S; DeMaria, Samuel; Lin, Hung-Mo; Levine, Adam I; Hyman, Jaime B

    2016-07-01

    Awake intubation is the standard of care for management of the anticipated difficult airway. The performance of awake intubation may be perceived as complex and time-consuming, potentially leading clinicians to avoid this technique of airway management. This retrospective review of awake intubations at a large academic medical center was performed to determine the average time taken to perform awake intubation, its effects on hemodynamics, and the incidence and characteristics of complications and failure. Anesthetic records from 2007 to 2014 were queried for the performance of an awake intubation. Of the 1,085 awake intubations included for analysis, 1,055 involved the use of a flexible bronchoscope. Each awake intubation case was propensity matched with two controls (1:2 ratio), with similar comorbidities and intubations performed after the induction of anesthesia (n = 2,170). The time from entry into the operating room until intubation was compared between groups. The anesthetic records of all patients undergoing awake intubation were also reviewed for failure and complications. The median time to intubation for patients intubated post induction was 16.0 min (interquartile range: 13 to 22) from entrance into the operating room. The median time to intubation for awake patients was 24.0 min (interquartile range: 19 to 31). The complication rate was 1.6% (17 of 1,085 cases). The most frequent complications observed were mucous plug, endotracheal tube cuff leak, and inadvertent extubation. The failure rate for attempted awake intubation was 1% (n = 10). Awake intubations have a high rate of success and low rate of serious complications and failure. Awake intubations can be performed safely and rapidly.

  11. Microstructure-based constitutive modeling of TRIP steel: Prediction of ductility and failure modes under different loading conditions

    International Nuclear Information System (INIS)

    Choi, K.S.; Liu, W.N.; Sun, X.; Khaleel, M.A.

    2009-01-01

    We study the ultimate ductility and failure modes of a commercial transformation-induced plasticity (TRIP) 800 steel under different loading conditions with an advanced microstructure-based finite-element analysis. The representative volume element (RVE) for the TRIP 800 under examination is developed based on an actual microstructure obtained from scanning electron microscopy. The ductile failure of the TRIP 800 under different loading conditions is predicted in the form of plastic strain localization without any prescribed failure criteria for the individual phases. This indicates that the microstructure-level inhomogeneity of the various constituent phases can be the key factor influencing the final ductility of the TRIP 800 steel under different loading conditions. Comparisons of the computational results with experimental measurements suggest that the microstructure-based modeling approach accurately captures the overall macroscopic behavior of the TRIP 800 steel under different loading and boundary conditions.

  12. Preditores de falha da extubação em crianças no pós-operatório de cirurgia cardíaca submetidas à ventilação pulmonar mecânica Post cardiac surgery In children: extubation failure predictor's

    Directory of Open Access Journals (Sweden)

    Cíntia Johnston

    2008-03-01

    = 0,002] e PiMáx [53 ± 18 versus 78 ± 28 cmH2O; p = 0,002]. Através da curva ROC identificou-se 100% de sensibilidade e 80% de especificidade no ponto de corte do IO > 2 (área 0,74, p = 0,017 e da RCF > 4 (área 0,80, p = 0,002; 80% de sensibilidade e 60% de especificidade da PiMáx 2, RCF > 4, tempo de VPM > 3 dias, V E BACKGROUND AND OBJECTIVES: It is important to know the risk factors for extubation failure (EF in children submitted to cardiac surgery in order to avoid inherent events due to reintubation (airways injury, usage of medications, cardiovascular changes and because of prolonged ventilatory support (pneumonias, reduction of the ventilatory muscles strength. The objective of this study is to evaluate mechanical ventilation (MV parameters, ventilatory mechanics [rapid shallow breathing index (RSBI, ventilatory muscles force [the maximum inspiratory pressure (MIP, the maximum expiratory pressure (MEP and the load/force balance (LFB] and blood gases before and after extubation in pediatric patients undergoing cardiac surgery. METHODS: Prospective (March 2004 to March 2006 observational cross sectional study, enrolling children submitted to cardiac surgery admitted to an university PICU hospital and considered able to be extubated. With the tracheal tube in situ and maintaining the children spontaneously breathing we evaluate: expiratory minute volume (V E, MIP and MEP. We calculated the RSBI [(RR/VT/Weight], LFB [15x [(3xMAP/MIP] + 0.03 x RSBI-5], the mean airway pressure (MAP [MAP={(PIP-PEEPx[Ti/(Te+Ti]}+PEEP] and the oxygenation index (OI [OI=(FiO2 x MAP/PaO2x100]. Arterial blood gas was collected one hour before extubation. If after 48 hours there was no need to reintubate the patient the extubation was considered successful (SE. RESULTS: 59 children were included. EF was observed in 19% (11/59. Median (QI25%-75% for age, weight, MAP, OI, duration of MV after cardiac surgery (DMV were respectively, 36 (12-82 months, 12 (8-20 kg, 8 (6-9, 2 (2-5, 1 (1

  13. Do premorbid predictors of alcohol dependence also predict the failure to recover from alcoholism?

    DEFF Research Database (Denmark)

    Penick, Elizabeth C; Knop, Joachim; Nickel, Elizabeth J

    2010-01-01

    OBJECTIVE: In a search for viable endophenotypes of alcoholism, this longitudinal study attempted to identify premorbid predictors of alcohol dependence that also predicted the course of alcoholism. METHOD: The 202 male subjects who completed a 40-year follow-up were originally selected from...... diagnoses of alcohol abuse or alcohol dependence that were characterized as currently active or currently in remission according to Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised, course specifiers. RESULTS: The majority of subjects with a diagnosis of alcohol abuse were......: cognitive efficiency and early behavioral dyscontrol in childhood. Both factors predicted the failure to remit (low cognitive efficiency and high behavioral dyscontrol) even when lifetime alcoholism severity was controlled. CONCLUSIONS: This 4-decade study found a striking disconnect between measures...

  14. Shell feature: a new radiomics descriptor for predicting distant failure after radiotherapy in non-small cell lung cancer and cervix cancer

    Science.gov (United States)

    Hao, Hongxia; Zhou, Zhiguo; Li, Shulong; Maquilan, Genevieve; Folkert, Michael R.; Iyengar, Puneeth; Westover, Kenneth D.; Albuquerque, Kevin; Liu, Fang; Choy, Hak; Timmerman, Robert; Yang, Lin; Wang, Jing

    2018-05-01

    Distant failure is the main cause of human cancer-related mortalities. To develop a model for predicting distant failure in non-small cell lung cancer (NSCLC) and cervix cancer (CC) patients, a shell feature, consisting of outer voxels around the tumor boundary, was constructed using pre-treatment positron emission tomography (PET) images from 48 NSCLC patients received stereotactic body radiation therapy and 52 CC patients underwent external beam radiation therapy and concurrent chemotherapy followed with high-dose-rate intracavitary brachytherapy. The hypothesis behind this feature is that non-invasive and invasive tumors may have different morphologic patterns in the tumor periphery, in turn reflecting the differences in radiological presentations in the PET images. The utility of the shell was evaluated by the support vector machine classifier in comparison with intensity, geometry, gray level co-occurrence matrix-based texture, neighborhood gray tone difference matrix-based texture, and a combination of these four features. The results were assessed in terms of accuracy, sensitivity, specificity, and AUC. Collectively, the shell feature showed better predictive performance than all the other features for distant failure prediction in both NSCLC and CC cohorts.

  15. Seismic energy data analysis of Merapi volcano to test the eruption time prediction using materials failure forecast method (FFM)

    Science.gov (United States)

    Anggraeni, Novia Antika

    2015-04-01

    The test of eruption time prediction is an effort to prepare volcanic disaster mitigation, especially in the volcano's inhabited slope area, such as Merapi Volcano. The test can be conducted by observing the increase of volcanic activity, such as seismicity degree, deformation and SO2 gas emission. One of methods that can be used to predict the time of eruption is Materials Failure Forecast Method (FFM). Materials Failure Forecast Method (FFM) is a predictive method to determine the time of volcanic eruption which was introduced by Voight (1988). This method requires an increase in the rate of change, or acceleration of the observed volcanic activity parameters. The parameter used in this study is the seismic energy value of Merapi Volcano from 1990 - 2012. The data was plotted in form of graphs of seismic energy rate inverse versus time with FFM graphical technique approach uses simple linear regression. The data quality control used to increase the time precision employs the data correlation coefficient value of the seismic energy rate inverse versus time. From the results of graph analysis, the precision of prediction time toward the real time of eruption vary between -2.86 up to 5.49 days.

  16. Prediction of potential failures in hydraulic gear pumps

    Directory of Open Access Journals (Sweden)

    E. Lisowski

    2010-07-01

    Full Text Available Hydraulic gear pumps are used in many machines and devices. In hydraulic systems of machines gear pumps are main component ofsupply unit or perform auxiliary function. Gear pumps opposite to vane pumps are less complicated. They consists of such components as:housing, gear wheels, bearings, shaft, seal for rotation motion which are not very sensitive for damage and that is why they are using veryoften. However, gear pumps are break down from time to time. Usually damage of pump cause shutting down of machines and devices.One of the way for identifying potential failures and foreseeing their effects is a quality method. On the basis of these methods apreventing action might be undertaken before failure appear. In this paper potential failures and damages of a gear pump were presented bythe usage of matrix FMEA analysis.

  17. Anthropometric indices of failure to thrive

    Science.gov (United States)

    Raynor, P.; Rudolf, M.

    2000-01-01

    AIMS—To compare five anthropometric methods of classifying failure to thrive in order to ascertain their relative merits in predicting developmental, dietary, and eating problems.
METHODS—The five anthropometric methods were compared in 83 children with failure to thrive.
RESULTS—The methods were inconsistent in classification of severity, and no one method was superior in predicting problems.
CONCLUSIONS—Weight alone, being the simplest, is still the most reasonable marker for failure to thrive and associated problems.

 PMID:10799424

  18. Utility of the Instability Severity Index Score in Predicting Failure After Arthroscopic Anterior Stabilization of the Shoulder.

    Science.gov (United States)

    Phadnis, Joideep; Arnold, Christine; Elmorsy, Ahmed; Flannery, Mark

    2015-08-01

    The redislocation rate after arthroscopic stabilization for anterior glenohumeral instability is up to 30%. The Instability Severity Index Score (ISIS) was developed to preoperatively rationalize the risk of failure, but it has not yet been validated by an independent group. To assess the utility of the ISIS in predicting failure of arthroscopic anterior shoulder stabilization and to identify other preoperative factors for failure. Case-control study; Level of evidence, 3. A case-control study was performed on 141 consecutive patients, comparing those who suffered failure of arthroscopic stabilization with those who had successful arthroscopic stabilization. The mean follow-up time was 47 months (range, 24-132 months). The ISIS was applied retrospectively, and an analysis was performed to establish independent risk factors for failure. A receiver operator coefficient curve was constructed to set a threshold ISIS for considering alternative surgery. Of 141 patients, 19 (13.5%) suffered recurrent instability. The mean ISIS of the failed stabilization group was higher than that of the successful stabilization group (5.1 vs 1.7; P surgery (P < .001), age at first dislocation (P = .01), competitive-level participation in sports (P < .001), and participation in contact or overhead sports (P = .03). The presence of glenoid bone loss carried the highest risk of failure (70%). There was a 70% risk of failure if the ISIS was ≥4, as opposed to a 4% risk of failure if the ISIS was <4. This is the first completely independent study to confirm that the ISIS is a useful preoperative tool. It is recommended that surgeons consider alternative forms of stabilization if the ISIS is ≥4. © 2015 The Author(s).

  19. Respiratory failure in tetanic patient: maintenance of airway problem in intensive care unit setting

    Science.gov (United States)

    Utami, I. N.; Arifin; Susilo, R. S. B.; Redhono, D.; Sumandjar, T.

    2018-03-01

    Tetanus is a toxin-mediated disease caused by Clostridium tetani resulting in muscular stiffness and painful spasm. The case fatality rates are high (10-80%), and the most frequent cause of mortality is airway problem that results in respiratory failure. A 52-year-old malecame to the hospital with lockjaw, rhesussardonicus, opisthotonus, and seizure for the last 12 hours, diagnosed with tetanus grade II. We placed the patient in an isolation room, gave 3000U tetanus immunoglobulin, 20mg diazepam in 500ml dextrose 5%/8 hours, and 500mg/6hrs metronidazole. On the seventh day, seizure became frequent, respiratory rate increased with crackles found on the auscultation, and the blood gas analysis showed respiratory failure type II (PCO2 53mmHg). The patientwas immediately sent to the ICU, intubated and given ventilator support. The patientwas sedated with continuous injection of midazolam 3 mg/h, morphine 10mcg/kgBW/h and also levofloxacin 750mg/24hours. Bronchoalveolar lavage culture was positive for Acinetobacter baumanii, so we changed the antibiotic to amikacin injection 500 mg/8hrs. After four days, we extubated the ventilator and transferred from HCU three days later. The patient was fully recovered and discharged after eighteen days of hospitalization.

  20. Multi-Marker Strategy in Heart Failure: Combination of ST2 and CRP Predicts Poor Outcome.

    Directory of Open Access Journals (Sweden)

    Anne Marie Dupuy

    Full Text Available Natriuretic peptides (BNP and NT-proBNP are recognized as gold-standard predictive markers in Heart Failure (HF. However, currently ST2 (member of the interleukin 1 receptor family has emerged as marker of inflammation, fibrosis and cardiac stress. We evaluated ST2 and CRP as prognostic markers in 178 patients with chronic heart failure in comparison with other classical markers such as clinical established parameters but also biological markers: NT-proBNP, hs-cTnT alone or in combination. In multivariate analysis, subsequent addition of ST2 led to age, CRP and ST2 as the only remaining predictors of all-cause mortality (HR 1.03, HR 1.61 and HR 2.75, respectively as well as of cardiovascular mortality (HR 1.00, HR 2.27 and HR 3.78, respectively. The combined increase of ST2 and CRP was significant for predicting worsened outcomes leading to identify a high risk subgroup that individual assessment of either marker. The same analysis was performed with ST2 in combination with Barcelona score. Overall, our findings extend previous data demonstrating that ST2 in combination with CRP as a valuable tool for identifying patients at risk of death.

  1. Predictive value of daily living score in acute respiratory failure of COPD patients requiring invasive mechanical ventilation pilot study

    Directory of Open Access Journals (Sweden)

    Langlet Ketty

    2012-10-01

    Full Text Available Abstract Background Mechanical ventilation (MV is imperative in many forms of acute respiratory failure (ARF in COPD patients. Previous studies have shown the difficulty to identify parameters predicting the outcome of COPD patients treated by invasive MV. Our hypothesis was that a non specialized score as the activities daily living (ADL score may help to predict the outcome of these patients. Methods We studied the outcome of 25 COPD patients admitted to the intensive care unit for ARF requiring invasive MV. The patients were divided into those weaning success (group A n = 17, 68% or failure (group B n = 8, 32%. We investigated the correlation between the ADL score and the outcome and mortality. Results The ADL score was higher in group A (5.1 ±1.1 vs 3.7 ± 0.7 in group B, p  Conclusion Our pilot study demonstrates that the ADL score is predictive of weaning success and mortality at 6 months, suggesting that the assessment of daily activities should be an important component of ARF management in COPD patients.

  2. Long-term success and failure with SG is predictable by 3 months: a multivariate model using simple office markers.

    Science.gov (United States)

    Cottam, Austin; Billing, Josiah; Cottam, Daniel; Billing, Peter; Cottam, Samuel; Zaveri, Hinali; Surve, Amit

    2017-08-01

    Despite being the most common surgery in the United States, little is known about predicting weight loss success and failure with sleeve gastrectomy (SG). Papers that have been published are inconclusive. We decided to use multivariate analysis from 2 practices to design a model to predict weight loss outcomes using data widely available to any surgical practice at 3 months to determine weight loss outcomes at 1 year. Two private practices in the United States. A retrospective review of 613 patients from 2 bariatric institutions were included in this study. Co-morbidities and other preoperative characteristics were gathered, and %EWL was calculated for 1, 3, and 12 months. Excess weight loss (%EWL)failure. Multiple variate analysis was used to find factors that affect %EWL at 12 months. Preoperative sleep apnea, preoperative diabetes, %EWL at 1 month, and %EWL at 3 months all affect %EWL at 1 year. The positive predictive value and negative predictive value of our model was 72% and 91%, respectively. Sensitivity and specificity were 71% and 91%, respectively. One-year results of the SG can be predicted by diabetes, sleep apnea, and weight loss velocity at 3 months postoperatively. This can help surgeons direct surgical or medical interventions for patients at 3 months rather than at 1 year or beyond. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

  3. Prediction of Basic Math Course Failure Rate in the Physics, Meteorology, Mathematics, Actuarial Sciences and Pharmacy Degree Programs

    Directory of Open Access Journals (Sweden)

    Luis Rojas-Torres

    2014-09-01

    Full Text Available This paper summarizes a study conducted in 2013 with the purpose of predicting the failure rate of math courses taken by Pharmacy, Mathematics, Actuarial Science, Physics and Meteorology students at Universidad de Costa Rica (UCR. Using the Logistics Regression statistical techniques applied to the 2010 cohort, failure rates were predicted of students in the aforementioned programs in one of their Math introductory courses (Calculus 101 for Physics and Meteorology, Math Principles for Mathematics and Actuarial Science and Applied Differential Equations for Pharmacy. For these models, the UCR admission average, the student’s genre, and the average correct answers in the Quantitative Skills Test were used as predictor variables. The most important variable for all models was the Quantitative Skills Test, and the model with the highest correct classification rate was the Logistics Regression. For the estimated Physics-Meteorology, Pharmacy and Mathematics-Actuarial Science models, correct classifications were 89.8%, 73.6%, and 93.9%, respectively.

  4. The failure of earthquake failure models

    Science.gov (United States)

    Gomberg, J.

    2001-01-01

    In this study I show that simple heuristic models and numerical calculations suggest that an entire class of commonly invoked models of earthquake failure processes cannot explain triggering of seismicity by transient or "dynamic" stress changes, such as stress changes associated with passing seismic waves. The models of this class have the common feature that the physical property characterizing failure increases at an accelerating rate when a fault is loaded (stressed) at a constant rate. Examples include models that invoke rate state friction or subcritical crack growth, in which the properties characterizing failure are slip or crack length, respectively. Failure occurs when the rate at which these grow accelerates to values exceeding some critical threshold. These accelerating failure models do not predict the finite durations of dynamically triggered earthquake sequences (e.g., at aftershock or remote distances). Some of the failure models belonging to this class have been used to explain static stress triggering of aftershocks. This may imply that the physical processes underlying dynamic triggering differs or that currently applied models of static triggering require modification. If the former is the case, we might appeal to physical mechanisms relying on oscillatory deformations such as compaction of saturated fault gouge leading to pore pressure increase, or cyclic fatigue. However, if dynamic and static triggering mechanisms differ, one still needs to ask why static triggering models that neglect these dynamic mechanisms appear to explain many observations. If the static and dynamic triggering mechanisms are the same, perhaps assumptions about accelerating failure and/or that triggering advances the failure times of a population of inevitable earthquakes are incorrect.

  5. Neurohumoral prediction of left-ventricular morphologic response to beta-blockade with metoprolol in chronic left-ventricular systolic heart failure

    DEFF Research Database (Denmark)

    Groenning, Bjoern A; Nilsson, Jens C; Hildebrandt, Per R

    2002-01-01

    BACKGROUND: In order to tailor therapy in heart failure, a solution might be to develop sensitive and reliable markers that can predict response in individual patients or monitor effectiveness of therapy. AIMS: To evaluate neurohumoral factors as markers for left-ventricular (LV) antiremodelling...... from metoprolol treatment in patients with chronic LV systolic heart failure. METHODS: Forty-one subjects randomised to placebo or metoprolol were studied with magnetic resonance imaging and blood samples to measure LV dimensions and ejection fraction, epinephrine, norepinephrine, plasma renin activity......-treatment plasma level of ANP may be a predictor of LV antiremodelling from treatment with metoprolol in patients with chronic heart failure. However, the potential for individual neurohumoral monitoring of the effects on LV dimensions during beta-blockade appears limited....

  6. Postoperative Prostate-Specific Antigen Velocity Independently Predicts for Failure of Salvage Radiotherapy After Prostatectomy

    International Nuclear Information System (INIS)

    King, Christopher R.; Presti, Joseph C.; Brooks, James D.; Gill, Harcharan; Spiotto, Michael T.

    2008-01-01

    Purpose: Identification of patients most likely to benefit from salvage radiotherapy (RT) using postoperative (postop) prostate-specific antigen (PSA) kinetics. Methods and Materials: From 1984 to 2004, 81 patients who fit the following criteria formed the study population: undetectable PSA after radical prostatectomy (RP); pathologically negative nodes; biochemical relapse defined as a persistently detectable PSA; salvage RT; and two or more postop PSAs available before salvage RT. Salvage RT included the whole pelvic nodes in 55 patients and 4 months of total androgen suppression in 56 patients. The median follow-up was >5 years. All relapses were defined as a persistently detectable PSA. Kaplan-Meier and Cox proportional hazards multivariable analysis were performed for all clinical, pathological, and treatment factors predicting for biochemical relapse-free survival (bRFS). Results: There were 37 biochemical relapses observed after salvage RT. The 5-year bRFS after salvage RT for patients with postop prostate-specific antigen velocity ≤1 vs. >1 ng/ml/yr was 59% vs. 29%, p = 0.002. In multivariate analysis, only postop PSAV (p = 0.0036), pre-RT PSA level ≤1 (p = 0.037) and interval-to-relapse >10 months (p = 0.012) remained significant, whereas pelvic RT, hormone therapy, and RT dose showed a trend (p = ∼0.06). PSAV, but not prostate-specific antigen doubling time, predicted successful salvage RT, suggesting an association of zero-order kinetics with locally recurrent disease. Conclusions: Postoperative PSA velocity independently predicts for the failure of salvage RT and can be considered in addition to high-risk features when selecting patients in need of systemic therapy following biochemical failure after RP. For well-selected patients, salvage RT can achieve high cure rates

  7. Type-D personality but not depression predicts severity of anxiety in heart failure patients at 1-year follow-up

    DEFF Research Database (Denmark)

    Schiffer, Angélique A; Pedersen, Susanne S.; Broers, Herman

    2008-01-01

    Chronic heart failure (CHF) is a debilitating condition associated with poor outcome, including increased anxiety. However, anxiety and its determinants have not yet been studied systematically in CHF. We examined whether type-D personality and depressive symptoms would predict clinically signifi...

  8. Seismic energy data analysis of Merapi volcano to test the eruption time prediction using materials failure forecast method (FFM)

    International Nuclear Information System (INIS)

    Anggraeni, Novia Antika

    2015-01-01

    The test of eruption time prediction is an effort to prepare volcanic disaster mitigation, especially in the volcano’s inhabited slope area, such as Merapi Volcano. The test can be conducted by observing the increase of volcanic activity, such as seismicity degree, deformation and SO2 gas emission. One of methods that can be used to predict the time of eruption is Materials Failure Forecast Method (FFM). Materials Failure Forecast Method (FFM) is a predictive method to determine the time of volcanic eruption which was introduced by Voight (1988). This method requires an increase in the rate of change, or acceleration of the observed volcanic activity parameters. The parameter used in this study is the seismic energy value of Merapi Volcano from 1990 – 2012. The data was plotted in form of graphs of seismic energy rate inverse versus time with FFM graphical technique approach uses simple linear regression. The data quality control used to increase the time precision employs the data correlation coefficient value of the seismic energy rate inverse versus time. From the results of graph analysis, the precision of prediction time toward the real time of eruption vary between −2.86 up to 5.49 days

  9. Seismic energy data analysis of Merapi volcano to test the eruption time prediction using materials failure forecast method (FFM)

    Energy Technology Data Exchange (ETDEWEB)

    Anggraeni, Novia Antika, E-mail: novia.antika.a@gmail.com [Geophysics Sub-department, Physics Department, Faculty of Mathematic and Natural Science, Universitas Gadjah Mada. BLS 21 Yogyakarta 55281 (Indonesia)

    2015-04-24

    The test of eruption time prediction is an effort to prepare volcanic disaster mitigation, especially in the volcano’s inhabited slope area, such as Merapi Volcano. The test can be conducted by observing the increase of volcanic activity, such as seismicity degree, deformation and SO2 gas emission. One of methods that can be used to predict the time of eruption is Materials Failure Forecast Method (FFM). Materials Failure Forecast Method (FFM) is a predictive method to determine the time of volcanic eruption which was introduced by Voight (1988). This method requires an increase in the rate of change, or acceleration of the observed volcanic activity parameters. The parameter used in this study is the seismic energy value of Merapi Volcano from 1990 – 2012. The data was plotted in form of graphs of seismic energy rate inverse versus time with FFM graphical technique approach uses simple linear regression. The data quality control used to increase the time precision employs the data correlation coefficient value of the seismic energy rate inverse versus time. From the results of graph analysis, the precision of prediction time toward the real time of eruption vary between −2.86 up to 5.49 days.

  10. Chaos emerging in soil failure patterns observed during tillage: Normalized deterministic nonlinear prediction (NDNP) and its application.

    Science.gov (United States)

    Sakai, Kenshi; Upadhyaya, Shrinivasa K; Andrade-Sanchez, Pedro; Sviridova, Nina V

    2017-03-01

    Real-world processes are often combinations of deterministic and stochastic processes. Soil failure observed during farm tillage is one example of this phenomenon. In this paper, we investigated the nonlinear features of soil failure patterns in a farm tillage process. We demonstrate emerging determinism in soil failure patterns from stochastic processes under specific soil conditions. We normalized the deterministic nonlinear prediction considering autocorrelation and propose it as a robust way of extracting a nonlinear dynamical system from noise contaminated motion. Soil is a typical granular material. The results obtained here are expected to be applicable to granular materials in general. From a global scale to nano scale, the granular material is featured in seismology, geotechnology, soil mechanics, and particle technology. The results and discussions presented here are applicable in these wide research areas. The proposed method and our findings are useful with respect to the application of nonlinear dynamics to investigate complex motions generated from granular materials.

  11. Prediction of Cascading Collapse Occurrence due to the Effect of Hidden Failure of a Protection System using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Nor Hazwani Idris

    2017-06-01

    Full Text Available Transmission line act as a medium of transportation for electrical energy from a power station to the consumer. There are many factors that could cause the cascading collapse such as instability of voltage and frequency, the change of environment and weather, the software and operator error and also the failure in protection system. Protection system plays an important function in maintaining the stability and reliability of the power grid. Hidden failures in relay protection systems are the primary factors for triggering the cascading collapse. This paper presents an Artificial Neural Network (ANN model for prediction of cascading collapse occurrence due to the effect of hidden failure of protection system. The ANN model has been developed through the normalized training and testing data process with optimum number of hidden layer, the momentum rate and the learning rate. The ANN model employs probability of hidden failure, random number of line limit power flow and exposed line as its input while trip index of cascading collapse occurrence as its output. IEEE 14 bus system is used in this study to illustrate the proposed approach. The performance of the results is analysed in terms of its Mean Square Error (MSE and Correlation Coefficient (R. The results show the ANN model produce reliable prediction of cascading collapse occurrence.

  12. Optimization of Artificial Neural Network using Evolutionary Programming for Prediction of Cascading Collapse Occurrence due to the Hidden Failure Effect

    Science.gov (United States)

    Idris, N. H.; Salim, N. A.; Othman, M. M.; Yasin, Z. M.

    2018-03-01

    This paper presents the Evolutionary Programming (EP) which proposed to optimize the training parameters for Artificial Neural Network (ANN) in predicting cascading collapse occurrence due to the effect of protection system hidden failure. The data has been collected from the probability of hidden failure model simulation from the historical data. The training parameters of multilayer-feedforward with backpropagation has been optimized with objective function to minimize the Mean Square Error (MSE). The optimal training parameters consists of the momentum rate, learning rate and number of neurons in first hidden layer and second hidden layer is selected in EP-ANN. The IEEE 14 bus system has been tested as a case study to validate the propose technique. The results show the reliable prediction of performance validated through MSE and Correlation Coefficient (R).

  13. Predicting Subsequent Task Performance From Goal Motivation and Goal Failure

    Directory of Open Access Journals (Sweden)

    Laura Catherine Healy

    2015-07-01

    Full Text Available Recent research has demonstrated that the cognitive processes associated with goal pursuit can continue to interfere with unrelated tasks when a goal is unfulfilled. Drawing from the self-regulation and goal-striving literatures, the present study explored the impact of goal failure on subsequent cognitive and physical task performance. Furthermore, we examined if the autonomous or controlled motivation underpinning goal striving moderates the responses to goal failure. Athletes (75 male, 59 female, Mage = 19.90 years, SDage = 3.50 completed a cycling trial with the goal of covering a given distance in 8 minutes. Prior to the trial, their motivation was primed using a video. During the trial they were provided with manipulated performance feedback, thus creating conditions of goal success or failure. No differences emerged in the responses to goal failure between the primed motivation or performance feedback conditions. We make recommendations for future research into how individuals can deal with failure in goal striving.

  14. A nomogram for predicting distant brain failure in patients treated with gamma knife stereotactic radiosurgery without whole brain radiotherapy

    Science.gov (United States)

    Ayala-Peacock, Diandra N.; Peiffer, Ann M.; Lucas, John T.; Isom, Scott; Kuremsky, J. Griff; Urbanic, James J.; Bourland, J. Daniel; Laxton, Adrian W.; Tatter, Stephen B.; Shaw, Edward G.; Chan, Michael D.

    2014-01-01

    Background We review our single institution experience to determine predictive factors for early and delayed distant brain failure (DBF) after radiosurgery without whole brain radiotherapy (WBRT) for brain metastases. Materials and methods Between January 2000 and December 2010, a total of 464 patients were treated with Gamma Knife stereotactic radiosurgery (SRS) without WBRT for primary management of newly diagnosed brain metastases. Histology, systemic disease, RPA class, and number of metastases were evaluated as possible predictors of DBF rate. DBF rates were determined by serial MRI. Kaplan–Meier method was used to estimate rate of DBF. Multivariate analysis was performed using Cox Proportional Hazard regression. Results Median number of lesions treated was 1 (range 1–13). Median time to DBF was 4.9 months. Twenty-seven percent of patients ultimately required WBRT with median time to WBRT of 5.6 months. Progressive systemic disease (χ2= 16.748, P < .001), number of metastases at SRS (χ2 = 27.216, P < .001), discovery of new metastases at time of SRS (χ2 = 9.197, P < .01), and histology (χ2 = 12.819, P < .07) were factors that predicted for earlier time to distant failure. High risk histologic subtypes (melanoma, her2 negative breast, χ2 = 11.020, P < .001) and low risk subtypes (her2 + breast, χ2 = 11.343, P < .001) were identified. Progressive systemic disease (χ2 = 9.549, P < .01), number of brain metastases (χ2 = 16.953, P < .001), minimum SRS dose (χ2 = 21.609, P < .001), and widespread metastatic disease (χ2 = 29.396, P < .001) were predictive of shorter time to WBRT. Conclusion Systemic disease, number of metastases, and histology are factors that predict distant failure rate after primary radiosurgical management of brain metastases. PMID:24558022

  15. Do plasma concentrations of apelin predict prognosis in patients with advanced heart failure?

    Science.gov (United States)

    Dalzell, Jonathan R; Jackson, Colette E; Chong, Kwok S; McDonagh, Theresa A; Gardner, Roy S

    2014-01-01

    Apelin is an endogenous vasodilator and inotrope, plasma concentrations of which are reduced in advanced heart failure (HF). We determined the prognostic significance of plasma concentrations of apelin in advanced HF. Plasma concentrations of apelin were measured in 182 patients with advanced HF secondary to left ventricular systolic dysfunction. The predictive value of apelin for the primary end point of all-cause mortality was assessed over a median follow-up period of 544 (IQR: 196-923) days. In total, 30 patients (17%) reached the primary end point. Of those patients with a plasma apelin concentration above the median, 14 (16%) reached the primary end point compared with 16 (17%) of those with plasma apelin levels below the median (p = NS). NT-proBNP was the most powerful prognostic marker in this population (log rank statistic: 10.37; p = 0.001). Plasma apelin concentrations do not predict medium to long-term prognosis in patients with advanced HF secondary to left ventricular systolic dysfunction.

  16. [11C]Choline PET/CT predicts survival in hormone-naive prostate cancer patients with biochemical failure after radical prostatectomy

    International Nuclear Information System (INIS)

    Giovacchini, Giampiero; Incerti, Elena; Mapelli, Paola; Gianolli, Luigi; Picchio, Maria; Kirienko, Margarita; Briganti, Alberto; Gandaglia, Giorgio; Montorsi, Francesco

    2015-01-01

    Over the last decade, PET/CT with radiolabelled choline has been shown to be useful for restaging patients with prostate cancer (PCa) who develop biochemical failure. The limitations of most clinical studies have been poor validation of [ 11 C]choline PET/CT-positive findings and lack of survival analysis. The aim of this study was to assess whether [ 11 C]choline PET/CT can predict survival in hormone-naive PCa patients with biochemical failure. This retrospective study included 302 hormone-naive PCa patients treated with radical prostatectomy who underwent [ 11 C]choline PET/CT from 1 December 2004 to 31 July 2007 because of biochemical failure (prostate-specific antigen, PSA, >0.2 ng/mL). Median PSA was 1.02 ng/mL. PCa-specific survival was estimated using Kaplan-Meier curves. Cox regression analysis was used to evaluate the association between clinicopathological variables and PCa-specific survival. The coefficients of the covariates included in the Cox regression analysis were used to develop a novel nomogram. Median follow-up was 7.2 years (1.4 - 18.9 years). [ 11 C]Choline PET/CT was positive in 101 of 302 patients (33 %). Median PCa-specific survival after prostatectomy was 14.9 years (95 % CI 9.7 - 20.1 years) in patients with positive [ 11 C]choline PET/CT. Median survival was not achieved in patients with negative [ 11 C]choline PET/CT. The 15-year PCa-specific survival probability was 42.4 % (95 % CI 31.7 - 53.1 %) in patients with positive [ 11 C]choline PET/CT and 95.5 % (95 % CI 93.5 - 97.5 %) in patients with negative [ 11 C]choline PET/CT. In multivariate analysis, [ 11 C]choline PET/CT (hazard ratio 6.36, 95 % CI 2.14 - 18.94, P < 0.001) and Gleason score >7 (hazard ratio 3.11, 95 % CI 1.11 - 8.66, P = 0.030) predicted PCa-specific survival. An internally validated nomogram predicted 15-year PCa-specific survival probability with an accuracy of 80 %. Positive [ 11 C]choline PET/CT after biochemical failure predicts PCa-specific survival in hormone

  17. Failure analysis of high strength pipeline with single and multiple corrosions

    International Nuclear Information System (INIS)

    Chen, Yanfei; Zhang, Hong; Zhang, Juan; Li, Xin; Zhou, Jing

    2015-01-01

    Highlights: • We study failure of high strength pipelines with single corrosion. • We give regression equations for failure pressure prediction. • We propose assessment procedure for pipelines with multiple corrosions. - Abstract: Corrosion will compromise safety operation of oil and gas pipelines, accurate determination of failure pressure finds importance in residual strength assessment and corrosion allowance design of onshore and offshore pipelines. This paper investigates failure pressure of high strength pipeline with single and multiple corrosions using nonlinear finite element analysis. On the basis of developed regression equations for failure pressure prediction of high strength pipeline with single corrosion, the paper proposes an assessment procedure for predicting failure pressure of high strength pipeline with multiple corrosions. Furthermore, failure pressures predicted by proposed solutions are compared with experimental results and various assessment methods available in literature, where accuracy and versatility are demonstrated

  18. A probabilistic approach for RIA fuel failure criteria

    International Nuclear Information System (INIS)

    Carlo Vitanza, Dr.

    2008-01-01

    Substantial experimental data have been produced in support of the definition of the RIA safety limits for water reactor fuels at high burn up. Based on these data, fuel failure enthalpy limits can be derived based on methods having a varying degree of complexity. However, regardless of sophistication, it is unlikely that any deterministic approach would result in perfect predictions of all failure and non failure data obtained in RIA tests. Accordingly, a probabilistic approach is proposed in this paper, where in addition to a best estimate evaluation of the failure enthalpy, a RIA fuel failure probability distribution is defined within an enthalpy band surrounding the best estimate failure enthalpy. The band width and the failure probability distribution within this band are determined on the basis of the whole data set, including failure and non failure data and accounting for the actual scatter of the database. The present probabilistic approach can be used in conjunction with any deterministic model or correlation. For deterministic models or correlations having good prediction capability, the probability distribution will be sharply increasing within a narrow band around the best estimate value. For deterministic predictions of lower quality, instead, the resulting probability distribution will be broad and coarser

  19. Positive predictive value and impact of misdiagnosis of a heart failure diagnosis in administrative registers among patients admitted to a University Hospital cardiac care unit

    DEFF Research Database (Denmark)

    Mard, Shan; Nielsen, Finn Erland

    2010-01-01

    To evaluate the positive predictive value (PPV) of a diagnosis of heart failure (HF) in the Danish National Registry of Patients (NRP) among patients admitted to a University Hospital cardiac care unit, and to evaluate the impact of misdiagnosing HF.......To evaluate the positive predictive value (PPV) of a diagnosis of heart failure (HF) in the Danish National Registry of Patients (NRP) among patients admitted to a University Hospital cardiac care unit, and to evaluate the impact of misdiagnosing HF....

  20. Extubation versus tracheostomy in withdrawal of treatment-ethical, clinical, and legal perspectives.

    LENUS (Irish Health Repository)

    Chotirmall, Sanjay Haresh

    2010-06-01

    The provision of life-sustaining ventilation, such as tracheostomy to critically ill patients, is commonly performed. However, the utilization of tracheostomy or extubation after a withdrawal of treatment decision is debated. There is a dearth of practical information available to aid clinical decision making because withdrawal of treatment is a challenging scenario for all concerned. This is further complicated by medicolegal and ethical considerations. Care of the "hopelessly ill" patient should be based on daily evaluation and comfort making it impossible to fit into general algorithms. Although respect for autonomy is important in healthcare, it is limited for patients in an unconscious state. Beneficence remains the basis for withdrawing treatment in futile cases and underpins the "doctrine of double effect." This article presents a relevant clinical case of hypoxic brain injury where a question of withdrawal of treatment arose and examines the ethical, clinical, and medicolegal considerations inherent in such cases, including beneficence, nonmaleficence, and the "sanctity of life doctrine." In addition, the considerations of prognosis for recovery, patient autonomy, patient quality of life, and patient family involvement, which are central to decision making, are addressed. The varying legal frameworks that exist internationally regarding treatment withdrawal are also described. Good ethics needs sound facts, and despite the lack of legal foundation in several countries, withdrawal of treatment remains practiced, and the principles described within this article aim to aid clinician decision making during such complex and multifaceted end-of-life decisions.

  1. Probabilistic Physics of Failure-based framework for fatigue life prediction of aircraft gas turbine discs under uncertainty

    International Nuclear Information System (INIS)

    Zhu, Shun-Peng; Huang, Hong-Zhong; Peng, Weiwen; Wang, Hai-Kun; Mahadevan, Sankaran

    2016-01-01

    A probabilistic Physics of Failure-based framework for fatigue life prediction of aircraft gas turbine discs operating under uncertainty is developed. The framework incorporates the overall uncertainties appearing in a structural integrity assessment. A comprehensive uncertainty quantification (UQ) procedure is presented to quantify multiple types of uncertainty using multiplicative and additive UQ methods. In addition, the factors that contribute the most to the resulting output uncertainty are investigated and identified for uncertainty reduction in decision-making. A high prediction accuracy of the proposed framework is validated through a comparison of model predictions to the experimental results of GH4133 superalloy and full-scale tests of aero engine high-pressure turbine discs. - Highlights: • A probabilistic PoF-based framework for fatigue life prediction is proposed. • A comprehensive procedure forquantifyingmultiple types of uncertaintyis presented. • The factors that contribute most to the resulting output uncertainty are identified. • The proposed frameworkdemonstrates high prediction accuracybyfull-scale tests.

  2. Numerical models for the prediction of failure for multilayer fusion Al-alloy sheets

    International Nuclear Information System (INIS)

    Gorji, Maysam; Berisha, Bekim; Hora, Pavel; Timm, Jürgen

    2013-01-01

    Initiation and propagation of cracks in monolithic and multi-layer aluminum alloys, called “Fusion”, is investigated. 2D plane strain finite element simulations are performed to model deformation due to bending and to predict failure. For this purpose, fracture strains are measured based on microscopic pictures of Nakajima specimens. In addition to, micro-structure of materials is taken into account by introducing a random grain distribution over the sheet thickness as well as a random distribution of the measured yield curve. It is shown that the performed experiments and the introduced FE-Model are appropriate methods to highlight the advantages of the Fusion material, especially for bending processes

  3. Progressive Diaphragm Atrophy in Pediatric Acute Respiratory Failure.

    Science.gov (United States)

    Glau, Christie L; Conlon, Thomas W; Himebauch, Adam S; Yehya, Nadir; Weiss, Scott L; Berg, Robert A; Nishisaki, Akira

    2018-02-05

    Diaphragm atrophy is associated with delayed weaning from mechanical ventilation and increased mortality in critically ill adults. We sought to test for the presence of diaphragm atrophy in children with acute respiratory failure. Prospective, observational study. Single-center tertiary noncardiac PICU in a children's hospital. Invasively ventilated children with acute respiratory failure. Diaphragm thickness at end-expiration and end-inspiration were serially measured by ultrasound in 56 patients (median age, 17 mo; interquartile range, 5.5-52), first within 36 hours of intubation and last preceding extubation. The median duration of mechanical ventilation was 140 hours (interquartile range, 83-201). At initial measurement, thickness at end-expiration was 2.0 mm (interquartile range, 1.8-2.5) and thickness at end-inspiration was 2.5 mm (interquartile range, 2-2.8). The change in thickness at end-expiration during mechanical ventilation between first and last measurement was -13.8% (interquartile range, -27.4% to 0%), with a -3.4% daily atrophy rate (interquartile range, -5.6 to 0%). Thickening fraction = ([thickness at end-inspiration - thickness at end-expiration]/thickness at end-inspiration) throughout the course of mechanical ventilation was linearly correlated with spontaneous breathing fraction (beta coefficient, 9.4; 95% CI, 4.2-14.7; p = 0.001). For children with a period of spontaneous breathing fraction less than 0.5 during mechanical ventilation, those with exposure to a continuous neuromuscular blockade infusion (n = 15) had a significantly larger decrease in thickness at end-expiration compared with children with low spontaneous breathing fraction who were not exposed to a neuromuscular blockade infusion (n = 18) (-16.4%, [interquartile range, -28.4% to -7.0%] vs -7.3%; [interquartile range, -10.9% to -0%]; p = 0.036). Diaphragm atrophy is present in children on mechanical ventilation for acute respiratory failure. Diaphragm contractility, measured as

  4. Dead or Alive? Using Membrane Failure and Chlorophyll a Fluorescence to Predict Plant Mortality from Drought.

    Science.gov (United States)

    Guadagno, Carmela R; Ewers, Brent E; Speckman, Heather N; Aston, Timothy Llewellyn; Huhn, Bridger J; DeVore, Stanley B; Ladwig, Joshua T; Strawn, Rachel N; Weinig, Cynthia

    2017-09-01

    Climate models predict widespread increases in both drought intensity and duration in the next decades. Although water deficiency is a significant determinant of plant survival, limited understanding of plant responses to extreme drought impedes forecasts of both forest and crop productivity under increasing aridity. Drought induces a suite of physiological responses; however, we lack an accurate mechanistic description of plant response to lethal drought that would improve predictive understanding of mortality under altered climate conditions. Here, proxies for leaf cellular damage, chlorophyll a fluorescence, and electrolyte leakage were directly associated with failure to recover from drought upon rewatering in Brassica rapa (genotype R500) and thus define the exact timing of drought-induced death. We validated our results using a second genotype (imb211) that differs substantially in life history traits. Our study demonstrates that whereas changes in carbon dynamics and water transport are critical indicators of drought stress, they can be unrelated to visible metrics of mortality, i.e. lack of meristematic activity and regrowth. In contrast, membrane failure at the cellular scale is the most proximate cause of death. This hypothesis was corroborated in two gymnosperms ( Picea engelmannii and Pinus contorta ) that experienced lethal water stress in the field and in laboratory conditions. We suggest that measurement of chlorophyll a fluorescence can be used to operationally define plant death arising from drought, and improved plant characterization can enhance surface model predictions of drought mortality and its consequences to ecosystem services at a global scale. © 2017 American Society of Plant Biologists. All Rights Reserved.

  5. Predictors of treatment failure in young patients undergoing in vitro fertilization.

    Science.gov (United States)

    Jacobs, Marni B; Klonoff-Cohen, Hillary; Agarwal, Sanjay; Kritz-Silverstein, Donna; Lindsay, Suzanne; Garzo, V Gabriel

    2016-08-01

    The purpose of the study was to evaluate whether routinely collected clinical factors can predict in vitro fertilization (IVF) failure among young, "good prognosis" patients predominantly with secondary infertility who are less than 35 years of age. Using de-identified clinic records, 414 women model predicted probability of cycle failure. One hundred ninety-seven patients with both primary and secondary infertility had a failed IVF cycle, and 217 with secondary infertility had a successful live birth. None of the women with primary infertility had a successful live birth. The significant predictors for IVF cycle failure among young patients were fewer previous live births, history of biochemical pregnancies or spontaneous abortions, lower baseline antral follicle count, higher total gonadotropin dose, unknown infertility diagnosis, and lack of at least one fair to good quality embryo. The full model showed good predictive value (c = 0.885) for estimating risk of cycle failure; at ≥80 % predicted probability of failure, sensitivity = 55.4 %, specificity = 97.5 %, positive predictive value = 95.4 %, and negative predictive value = 69.8 %. If this predictive model is validated in future studies, it could be beneficial for predicting IVF failure in good prognosis women under the age of 35 years.

  6. Predictive value of daily living score in acute respiratory failure of COPD patients requiring invasive mechanical ventilation pilot study.

    Science.gov (United States)

    Langlet, Ketty; Van Der Linden, Thierry; Launois, Claire; Fourdin, Caroline; Cabaret, Philippe; Kerkeni, Nadia; Barbe, Coralie; Lebargy, François; Deslée, Gaetan

    2012-10-18

    Mechanical ventilation (MV) is imperative in many forms of acute respiratory failure (ARF) in COPD patients. Previous studies have shown the difficulty to identify parameters predicting the outcome of COPD patients treated by invasive MV. Our hypothesis was that a non specialized score as the activities daily living (ADL) score may help to predict the outcome of these patients. We studied the outcome of 25 COPD patients admitted to the intensive care unit for ARF requiring invasive MV. The patients were divided into those weaning success (group A n = 17, 68%) or failure (group B n = 8, 32%). We investigated the correlation between the ADL score and the outcome and mortality. The ADL score was higher in group A (5.1 ±1.1 vs 3.7 ± 0.7 in group B, p success and mortality at 6 months, suggesting that the assessment of daily activities should be an important component of ARF management in COPD patients.

  7. Light water reactor lower head failure analysis

    International Nuclear Information System (INIS)

    Rempe, J.L.; Chavez, S.A.; Thinnes, G.L.

    1993-10-01

    This document presents the results from a US Nuclear Regulatory Commission-sponsored research program to investigate the mode and timing of vessel lower head failure. Major objectives of the analysis were to identify plausible failure mechanisms and to develop a method for determining which failure mode would occur first in different light water reactor designs and accident conditions. Failure mechanisms, such as tube ejection, tube rupture, global vessel failure, and localized vessel creep rupture, were studied. Newly developed models and existing models were applied to predict which failure mechanism would occur first in various severe accident scenarios. So that a broader range of conditions could be considered simultaneously, calculations relied heavily on models with closed-form or simplified numerical solution techniques. Finite element techniques-were employed for analytical model verification and examining more detailed phenomena. High-temperature creep and tensile data were obtained for predicting vessel and penetration structural response

  8. Light water reactor lower head failure analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rempe, J.L.; Chavez, S.A.; Thinnes, G.L. [EG and G Idaho, Inc., Idaho Falls, ID (United States)] [and others

    1993-10-01

    This document presents the results from a US Nuclear Regulatory Commission-sponsored research program to investigate the mode and timing of vessel lower head failure. Major objectives of the analysis were to identify plausible failure mechanisms and to develop a method for determining which failure mode would occur first in different light water reactor designs and accident conditions. Failure mechanisms, such as tube ejection, tube rupture, global vessel failure, and localized vessel creep rupture, were studied. Newly developed models and existing models were applied to predict which failure mechanism would occur first in various severe accident scenarios. So that a broader range of conditions could be considered simultaneously, calculations relied heavily on models with closed-form or simplified numerical solution techniques. Finite element techniques-were employed for analytical model verification and examining more detailed phenomena. High-temperature creep and tensile data were obtained for predicting vessel and penetration structural response.

  9. Prediction of effects of punch shapes on tableting failure by using a multi-functional single-punch tablet press

    Directory of Open Access Journals (Sweden)

    Takashi Osamura

    2017-09-01

    Full Text Available We previously determined “Tableting properties” by using a multi-functional single-punch tablet press (GTP-1. We proposed plotting “Compactability” on the x-axis against “Manufacturability” on the y-axis to allow visual evaluation of “Tableting properties”. Various types of tableting failure occur in commercial drug production and are influenced by the amount of lubricant used and the shape of the punch. We used the GTP-1 to measure “Tableting properties” with different amounts of lubricant and compared the results with those of tableting on a commercial rotary tableting machine. Tablets compressed with a small amount of lubricant showed bad “Manufacturability”, leading to sticking of powder on punches. We also tested various punch shapes. The GTP-1 correctly predicted the actual tableting results for all punch shapes. With punches that were more likely to cause tableting failure, our system predicted the effects of lubricant quantity in the tablet formulation and the occurrence of sticking in the rotary tableting machine.

  10. Proteins Annexin A2 and PSA in Prostate Cancer Biopsies Do Not Predict Biochemical Failure.

    Science.gov (United States)

    Lamb, David S; Sondhauss, Sven; Dunne, Jonathan C; Woods, Lisa; Delahunt, Brett; Ferguson, Peter; Murray, Judith; Nacey, John N; Denham, James W; Jordan, T William

    2017-12-01

    We previously reported the use of mass spectrometry and western blotting to identify proteins from tumour regions of formalin-fixed paraffin-embedded biopsies from 16 men who presented with apparently localized prostate cancer, and found that annexin A2 (ANXA2) appeared to be a better predictor of subsequent biochemical failure than prostate-specific antigen (PSA). In this follow-up study, ANXA2 and PSA were measured using western blotting of proteins extracted from biopsies from 37 men from a subsequent prostate cancer trial. No significant differences in ANXA2 and PSA levels were observed between men with and without biochemical failure. The statistical effect sizes were small, d=0.116 for ANXA2, and 0.266 for PSA. ANXA2 and PSA proteins measured from biopsy tumour regions are unlikely to be good biomarkers for prediction of the clinical outcome of prostate cancer presenting with apparently localized disease. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  11. Risk Prediction Models for Incident Heart Failure: A Systematic Review of Methodology and Model Performance.

    Science.gov (United States)

    Sahle, Berhe W; Owen, Alice J; Chin, Ken Lee; Reid, Christopher M

    2017-09-01

    Numerous models predicting the risk of incident heart failure (HF) have been developed; however, evidence of their methodological rigor and reporting remains unclear. This study critically appraises the methods underpinning incident HF risk prediction models. EMBASE and PubMed were searched for articles published between 1990 and June 2016 that reported at least 1 multivariable model for prediction of HF. Model development information, including study design, variable coding, missing data, and predictor selection, was extracted. Nineteen studies reporting 40 risk prediction models were included. Existing models have acceptable discriminative ability (C-statistics > 0.70), although only 6 models were externally validated. Candidate variable selection was based on statistical significance from a univariate screening in 11 models, whereas it was unclear in 12 models. Continuous predictors were retained in 16 models, whereas it was unclear how continuous variables were handled in 16 models. Missing values were excluded in 19 of 23 models that reported missing data, and the number of events per variable was models. Only 2 models presented recommended regression equations. There was significant heterogeneity in discriminative ability of models with respect to age (P prediction models that had sufficient discriminative ability, although few are externally validated. Methods not recommended for the conduct and reporting of risk prediction modeling were frequently used, and resulting algorithms should be applied with caution. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Weaning newborn infants from mechanical ventilation

    Directory of Open Access Journals (Sweden)

    Paolo Biban

    2013-06-01

    Full Text Available Invasive mechanical ventilation is a life-saving procedure which is largely used in neonatal intensive care units, particularly in very premature newborn infants. However, this essential treatment may increase mortality and cause substantial morbidity, including lung or airway injuries, unplanned extubations, adverse hemodynamic effects, analgosedative dependency and severe infectious complications, such as ventilator-associated pneumonia. Therefore, limiting the duration of airway intubation and mechanical ventilator support is crucial for the neonatologist, who should aim to a shorter process of discontinuing mechanical ventilation as well as an earlier appreciation of readiness for spontaneous breathing trials. Unfortunately, there is scarce information about the best ways to perform an effective weaning process in infants undergoing mechanical ventilation, thus in most cases the weaning course is still based upon the individual judgment of the attending clinician. Nonetheless, some evidence indicate that volume targeted ventilation modes are more effective in reducing the duration of mechanical ventilation than traditional pressure limited ventilation modes, particularly in very preterm babies. Weaning and extubation directly from high frequency ventilation could be another option, even though its effectiveness, when compared to switching and subsequent weaning and extubating from conventional ventilation, is yet to be adequately investigated. Some data suggest the use of weaning protocols could reduce the weaning time and duration of mechanical ventilation, but better designed prospective studies are still needed to confirm these preliminary observations. Finally, the implementation of short spontaneous breathing tests in preterm infants has been shown to be beneficial in some centres, favoring an earlier extubation at higher ventilatory settings compared with historical controls, without worsening the extubation failure rate. Further

  13. Failure and damage analysis of advanced materials

    CERN Document Server

    Sadowski, Tomasz

    2015-01-01

    The papers in this volume present basic concepts and new developments in failure and damage analysis with focus on advanced materials such as composites, laminates, sandwiches and foams, and also new metallic materials. Starting from some mathematical foundations (limit surfaces, symmetry considerations, invariants) new experimental results and their analysis are shown. Finally, new concepts for failure prediction and analysis will be introduced and discussed as well as new methods of failure and damage prediction for advanced metallic and non-metallic materials. Based on experimental results the traditional methods will be revised.

  14. Failure mitigation in software defined networking employing load type prediction

    KAUST Repository

    Bouacida, Nader; Alghadhban, Amer Mohammad JarAlla; Alalmaei, Shiyam Mohammed Abdullah; Mohammed, Haneen; Shihada, Basem

    2017-01-01

    The controller is a critical piece of the SDN architecture, where it is considered as the mastermind of SDN networks. Thus, its failure will cause a significant portion of the network to fail. Overload is one of the common causes of failure since

  15. Leishmania Antigenuria to Predict Initial Treatment Failure and Relapse in Visceral Leishmaniasis/HIV Coinfected Patients: An Exploratory Study Nested Within a Clinical Trial in Ethiopia.

    Science.gov (United States)

    van Griensven, Johan; Mengesha, Bewketu; Mekonnen, Tigist; Fikre, Helina; Takele, Yegnasew; Adem, Emebet; Mohammed, Rezika; Ritmeijer, Koert; Vogt, Florian; Adriaensen, Wim; Diro, Ermias

    2018-01-01

    Background: Biomarkers predicting the risk of VL treatment failure and relapse in VL/HIV coinfected patients are needed. Nested within a two-site clinical trial in Ethiopia (2011-2015), we conducted an exploratory study to assess whether (1) levels of Leishmania antigenuria measured at VL diagnosis were associated with initial treatment failure and (2) levels of Leishmania antigenuria at the end of treatment (parasitologically-confirmed cure) were associated with subsequent relapse. Methods: Leishmania antigenuria at VL diagnosis and cure was determined using KAtex urine antigen test and graded as negative (0), weak/moderate (grade 1+/2+) or strongly-positive (3+). Logistic regression and Kaplan-Meier methods were used to assess the association between antigenuria and (1) initial treatment failure, and (2) relapse over the 12 months after cure, respectively. Results: The analysis to predict initial treatment failure included sixty-three coinfected adults [median age: 30 years interquartile range (IQR) 27-35], median CD4 count: 56 cells/μL (IQR 38-113). KAtex results at VL diagnosis were negative in 11 (17%), weak/moderate in 17 (27%) and strongly-positive in 35 (36%). Twenty (32%) patients had parasitologically-confirmed treatment failure, with a risk of failure of 9% (1/11) with KAtex-negative results, 0% (0/17) for KAtex 1+/2+ and 54% (19/35) for KAtex 3+ results. Compared to KAtex-negative patients, KAtex 3+ patients were at increased risk of treatment failure [odds ratio 11.9 (95% CI 1.4-103.0); P : 0.025]. Forty-four patients were included in the analysis to predict relapse [median age: 31 years (IQR 28-35), median CD4 count: 116 cells/μL (IQR 95-181)]. When achieving VL cure, KAtex results were negative in 19 (43%), weak/moderate (1+/2+) in 10 (23%), and strongly positive (3+) in 15 patients (34%). Over the subsequent 12 months, eight out of 44 patients (18%) relapsed. The predicted 1-year relapse risk was 6% for KAtex-negative results, 14% for KAtex 1

  16. Failure modes of composite sandwich beams

    Directory of Open Access Journals (Sweden)

    Gdoutos E.

    2008-01-01

    Full Text Available A thorough investigation of failure behavior of composite sandwich beams under three-and four-point bending was undertaken. The beams were made of unidirectional carbon/epoxy facings and a PVC closed-cell foam core. The constituent materials were fully characterized and in the case of the foam core, failure envelopes were developed for general two-dimensional states of stress. Various failure modes including facing wrinkling, indentation failure and core failure were observed and compared with analytical predictions. The initiation, propagation and interaction of failure modes depend on the type of loading, constituent material properties and geometrical dimensions.

  17. Advancement Flap for Treatment of Complex Cryptoglandular Anal Fistula: Prediction of Therapy Success or Failure Using Anamnestic and Clinical Parameters.

    Science.gov (United States)

    Boenicke, Lars; Karsten, Eduard; Zirngibl, Hubert; Ambe, Peter

    2017-09-01

    Multiple new procedures for treatment of complex anal fistula have been described in the past decades, but an ideal single technique has yet not been identified. Factors that predict the outcome are required to identify the best procedure for each individual patient. The aim of this study was to find those predictors for advancement flap at midterm follow-up. From 2012 to 2015 in a tertiary university clinic, all patients who underwent advancement flap for treatment of complex cryptoglandular fistula were prospectively enrolled. Pre- and postoperatively standardized anamnestic and clinical examinations were performed. Predictive factors for therapy failure were identified using univariate and multivariate analysis. Out of 65 patients, 61 (93%) completed all examinations and were included in the study. Therapy failure after a mean follow-up period of 25 months occurred in total n = 11 patients (18%). There was no significant disturbance of continence among the entire study cohort as shown by the incontinence score (preop 0.34 ± 0.91 pts., postop 0.37 ± 0.97 pts.; p = 0.59). Univariate analysis for risk factors for therapy failure revealed age (p = 0.004), history of surgical abscess drainage (p = 0.04), BMI (p = 0.002), suprasphincteric fistula (p = 0.019) and horseshoe abscess (p = 0.036) as independent parameters for therapy failure. During multivariate analysis, only history of surgical abscess drainage (OR = 8.09, p = 0.048, 95% CI 0.98-64.96), suprasphincteric fistula (OR = 6.83, p = 0.032, 95% CI 1.17-6.83) and BMI (OR = 1.23, p = 0.017, 95% CI 1.03-1.46) were independent parameters for therapy failure. Advancement flap for treatment of complex fistula is effective and has low risk of disturbed continence. BMI, suprasphincteric fistula and history of surgical abscess drainage are predictors for therapy failure.

  18. Predicting Factors of INSURE Failure in Low Birth Weight Neonates with RDS; A Logistic Regression Model

    OpenAIRE

    Bita Najafian; Aminsaburi Aminsaburi; Seyyed Hassan Fakhraei; Abolfazl afjeh; Fatemeh Eghbal; Reza Noroozian

    2015-01-01

    Background:Respiratory Distress syndrome is the most common respiratory disease in premature neonate and the most important cause of death among them. We aimed to investigate factors to predict successful or failure of INSURE method as a therapeutic method of RDS. Methods:In a cohort study,45 neonates with diagnosed RDS and birth weight lower than 1500g were included and they underwent INSURE followed by NCPAP(Nasal Continuous Positive Airway Pressure). The patients were divided into failu...

  19. A prediction model for 5-year cardiac mortality in patients with chronic heart failure using {sup 123}I-metaiodobenzylguanidine imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Kenichi; Matsuo, Shinro [Kanazawa University Hospital, Department of Nuclear Medicine, Kanazawa (Japan); Nakata, Tomoaki [Sapporo Medical University School of Medicine, Second Department of Internal Medicine (Cardiology), Sapporo (Japan); Hakodate-Goryoukaku Hospital, Department of Cardiology, Hakodate (Japan); Yamada, Takahisa [Osaka Prefectural General Medical Center, Department of Cardiology, Osaka (Japan); Yamashina, Shohei [Toho University Omori Medical Center, Department of Cardiovascular Medicine, Tokyo (Japan); Momose, Mitsuru [Tokyo Women' s Medical University, Department of Nuclear Medicine, Tokyo (Japan); Kasama, Shu [Cardiovascular Hospital of Central Japan, Department of Cardiology, Shibukawa (Japan); Matsui, Toshiki [Social Insurance Shiga General Hospital, Department of Cardiology, Otsu (Japan); Travin, Mark I. [Albert Einstein Medical College, Department of Cardiology and Nuclear Medicine, Montefiore Medical Center, Bronx, NY (United States); Jacobson, Arnold F. [GE Healthcare, Medical Diagnostics, Princeton, NJ (United States)

    2014-09-15

    Prediction of mortality risk is important in the management of chronic heart failure (CHF). The aim of this study was to create a prediction model for 5-year cardiac death including assessment of cardiac sympathetic innervation using data from a multicenter cohort study in Japan. The original pooled database consisted of cohort studies from six sites in Japan. A total of 933 CHF patients who underwent {sup 123}I-metaiodobenzylguanidine (MIBG) imaging and whose 5-year outcomes were known were selected from this database. The late MIBG heart-to-mediastinum ratio (HMR) was used for quantification of cardiac uptake. Cox proportional hazard and logistic regression analyses were used to select appropriate variables for predicting 5-year cardiac mortality. The formula for predicting 5-year mortality was created using a logistic regression model. During the 5-year follow-up, 205 patients (22 %) died of a cardiac event including heart failure death, sudden cardiac death and fatal acute myocardial infarction (64 %, 30 % and 6 %, respectively). Multivariate logistic analysis selected four parameters, including New York Heart Association (NYHA) functional class, age, gender and left ventricular ejection fraction, without HMR (model 1) and five parameters with the addition of HMR (model 2). The net reclassification improvement analysis for all subjects was 13.8 % (p < 0.0001) by including HMR and its inclusion was most effective in the downward reclassification of low-risk patients. Nomograms for predicting 5-year cardiac mortality were created from the five-parameter regression model. Cardiac MIBG imaging had a significant additive value for predicting cardiac mortality. The prediction formula and nomograms can be used for risk stratifying in patients with CHF. (orig.)

  20. Value of routine investigations to predict loop diuretic down-titration success in stable heart failure.

    Science.gov (United States)

    Martens, Pieter; Verbrugge, Frederik H; Boonen, Levinia; Nijst, Petra; Dupont, Matthias; Mullens, Wilfried

    2018-01-01

    Guidelines advocate down-titration of loop diuretics in chronic heart failure (CHF) when patients have no signs of volume overload. Limited data are available on the expected success rate of this practice or how routine diagnostic tests might help steering this process. Fifty ambulatory CHF-patients on stable neurohumoral blocker/diuretic therapy for at least 3months without any clinical sign of volume overload were prospectively included to undergo loop diuretic down-titration. All patients underwent a similar pre-down-titration evaluation consisting of a dyspnea scoring, physical examination, transthoracic echocardiography (diastolic function, right ventricular function, cardiac filling pressures and valvular disease), blood sample (serum creatinine, plasma NT-pro-BNP and neurohormones). Loop diuretic maintenance dose was subsequently reduced by 50% or stopped if dose was ≤40mg furosemide equivalents. Successful down-titration was defined as a persistent dose reduction after 30days without weight increase >1.5kg or new-onset symptoms of worsening heart failure. At 30-day follow-up, down-titration was successful in 62% (n=31). In 12/19 patients exhibiting down-titration failure, this occurred within the first week. Physical examination, transthoracic echocardiography and laboratory analysis had limited predictive capability to detect patients with down-titration success/failure (positive likelihood-ratios below 1.5, or area under the curve [AUC] non-statically different from AUC=0.5). Loop diuretic down-titration is feasible in a majority of stable CHF patients in which the treating clinician felt continuation of loops was unnecessary to sustain euvolemia. Importantly, routine diagnostics which suggest euvolemia, have limited diagnostic impact on the post-test probability. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Edema agudo do pulmão pós-extubação traqueal - Caso clínico Post-tracheal extubation pulmonary oedema - Case report

    Directory of Open Access Journals (Sweden)

    Maria de Lurdes Castro

    2009-05-01

    Full Text Available O edema agudo do pulmão pós-extubação traqueal é um acontecimento raro (≈ 0,1%¹. A etiologia e multifactorial, sendo a obstrução da via aérea superior o factor desencadeante principal. O esforço inspiratório contra a glote encerrada causa pressões intratorácicas muito negativas, que se transmitem ao interstício pulmonar, condicionando uma transudação de fluidos a partir dos vasos capilares pulmonares1-5. Relatamos um caso de edema agudo do pulmão pós-extubação num doente de quinze anos, operado no serviço de urgência por amputação traumática da perna esquerda. Revemos a fisiopatologia, o padrão radiológico, potenciais factores de risco e medidas preventivas desta complicação respiratória pós-anestésica.Negative pressure pulmonary oedema is an uncommon complication of traqueal extubation (≈ 0,1%¹ mostly caused by acute upper airway obs truction. Upper airway obstruction from glottis closure leads to marked inspiratory effort, which generates negative intrathoracic pressure transmitting to pulmonary interstitium, and inducing fluid transudation from pulmonary capillary bed1-5. We report a case of post-extubation pulmonary oedema in a fifteen years old patient, submitted to surgery following traumatic amputation of his left leg. We review the pathophysiology, radiological findings, potential risk factors and preventive measures of this post-anaesthetic respiratory complication.

  2. Predicting Bank Financial Failures Using Discriminant Analysis And Support Vector Machines Methods A Comparative Analysis In Commercial Banks In Sudan 2006-2014

    Directory of Open Access Journals (Sweden)

    Mohammed A. SirElkhatim

    2017-04-01

    Full Text Available Bank failures threaten the economic system as a whole. Therefore predicting bank financial failures is crucial to prevent andor lessen its negative effects on the economic system. Financial crises affecting both emerging markets and advanced countries over the centuries have severe economic consequences but they can be hard to prevent and predict identifying financial crises causes remains both science and art said Stijn Claessens assistant director of the International Monetary Fund. While it would be better to mitigate risks financial crises will recur often in waves and better crisis management is therefore important. Analyses of recurrent causes suggest that to prevent crises governments should consider reforms in many underlying areas. That includes developing prudent fiscal and monetary policies better regulating the financial sector including reducing the problem of too-big-to-fail banks and developing effective macro-prudential policies. Despite new regulations and better supervision crises are likely to recur in part because they can reflect deeper problems related to income inequality the political economy and common human behavior. As such improvements in crisis management are also needed. This is originally a classification problem to categorize banks as healthy or non-healthy ones. This study aims to apply Discriminant analysis and Support Vector Machines methods to the bank failure prediction problem in a Sudanese case and to present a comprehensive computational comparison of the classification performances of the techniques tested. Eleven financial and non-financial ratios with six feature groups including capital adequacy asset quality Earning and liquidity CAMELS are selected as predictor variables in the study. Credit risk also been evaluated using logistic analysis to study the effect of Islamic finance modes sectors and payment types used by Sudanese banks with regard to their possibilities of failure. Experimental results

  3. The ADHF/NT-proBNP risk score to predict 1-year mortality in hospitalized patients with advanced decompensated heart failure.

    Science.gov (United States)

    Scrutinio, Domenico; Ammirati, Enrico; Guida, Pietro; Passantino, Andrea; Raimondo, Rosa; Guida, Valentina; Sarzi Braga, Simona; Canova, Paolo; Mastropasqua, Filippo; Frigerio, Maria; Lagioia, Rocco; Oliva, Fabrizio

    2014-04-01

    The acute decompensated heart failure/N-terminal pro-B-type natriuretic peptide (ADHF/NT-proBNP) score is a validated risk scoring system that predicts mortality in hospitalized heart failure patients with a wide range of left ventricular ejection fractions (LVEFs). We sought to assess discrimination and calibration of the score when applied to patients with advanced decompensated heart failure (AHF). We studied 445 patients hospitalized for AHF, defined by the presence of severe symptoms of worsening HF at admission, severely depressed LVEF, and the need for intravenous diuretic and/or inotropic drugs. The primary outcome was cumulative (in-hospital and post-discharge) mortality and post-discharge 1-year mortality. Separate analyses were performed for patients aged ≤ 70 years. A Seattle Heart Failure Score (SHFS) was calculated for each patient discharged alive. During follow-up, 144 patients (32.4%) died, and 69 (15.5%) underwent heart transplantation (HT) or ventricular assist device (VAD) implantation. After accounting for the competing events (VAD/HT), the ADHF/NT-proBNP score's C-statistic for cumulative mortality was 0.738 in the overall cohort and 0.771 in patients aged ≤ 70 years. The C-statistic for post-discharge mortality was 0.741 and 0.751, respectively. Adding prior (≤6 months) hospitalizations for HF to the score increased the C-statistic for post-discharge mortality to 0.759 in the overall cohort and to 0.774 in patients aged ≤ 70 years. Predicted and observed mortality rates by quartiles of score were highly correlated. The SHFS demonstrated adequate discrimination but underestimated the risk. The ADHF/NT-proBNP risk calculator is available at http://www.fsm.it/fsm/file/NTproBNPscore.zip. Our data suggest that the ADHF/NT-proBNP score may efficiently predict mortality in patients hospitalized with AHF. Copyright © 2014 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

  4. Embedded mechatronic systems 1 analysis of failures, predictive reliability

    CERN Document Server

    El Hami, Abdelkhalak

    2015-01-01

    In operation, mechatronics embedded systems are stressed by loads of different causes: climate (temperature, humidity), vibration, electrical and electromagnetic. These stresses in components which induce failure mechanisms should be identified and modeled for better control. AUDACE is a collaborative project of the cluster Mov'eo that address issues specific to mechatronic reliability embedded systems. AUDACE means analyzing the causes of failure of components of mechatronic systems onboard. The goal of the project is to optimize the design of mechatronic devices by reliability. The projec

  5. Predicting the Failure of Aluminum Exposed to Simulated Fire and Mechanical Loading Using Finite Element Modeling

    OpenAIRE

    Arthur, Katherine Marie

    2011-01-01

    The interest in the use of aluminum as a structural material in marine applications has increased greatly in recent years. This increase is primarily due to the low weight of aluminum compared to other structural materials as well as its ability to resist corrosion. However, a critical issue in the use of any structural material for naval applications is its response to fire. Past experience has shown that finite element programs can produce accurate predictions of failure of structural c...

  6. Comparison of Sugammadex and Neostigmine in Terms of Time to Extubation in Pediatrics

    Directory of Open Access Journals (Sweden)

    Dilek Güzelce

    2016-12-01

    Full Text Available Aim: Sugammadex is a cyclodextrin compound which provides complete recovery of residual neuromuscular blockade. In this study, we compared sugammadex and neostigmine in terms of time to achieve a train-of-four (TOF ratio of 0.9 and extubation time (TE. Methods: Thirty-seven patients, without lung disease and neuromuscular disease undergoing lower urinary tract surgery and inguinal hernia, were included in the study. Noninvasive arterial pressure, heart rate, pulse oximetry, and TOF-watch SX values were monitored during the surgery and, these parameters were recorded. After the surgery was completed, the patients were randomized into two groups: patients received either group neostigmine (group N 0.05 mcg/kg and group sugammadex (group S 2 mg/kg at reappearance of TOF ratio T2. Time to recovery to the TOF ratio of 0.9 (T0.9 and TE were compared between sugammadex and neostigmine Results: TE was found to be statistically longer in group N (6.06±2.47 minute than in group S (4.30±2.48 minute (p<0.041. Conclusion: We observed that sugammadex was more rapidly and effectively reversed the neuromuscular blockade compared to neostigmine. There were no serious adverse effects and significant hemodynamic changes in any measurement time. However, there is a limited number of studies on the safety and side effects of sugammadex in pediatric patients and additional data are needed to establish the safety in clinical practice.

  7. HE4 Serum Levels Are Associated with Heart Failure Severity in Patients With Chronic Heart Failure

    NARCIS (Netherlands)

    Piek, Arnold; Meijers, Wouter C.; Schroten, Nicolas F.; Gansevoort, Ron T.; de Boer, Rudolf A.; Sillje, Herman H. W.

    Background: The novel biomarker human epididymis protein 4 (HE4) shows prognostic value in acute heart failure (HF) patients. We measured HE4 levels in patients with chronic heart failure (CHF) and correlated them to HF severity, kidney function, and HF biomarkers, and determined its predictive

  8. A simple approach to modeling ductile failure.

    Energy Technology Data Exchange (ETDEWEB)

    Wellman, Gerald William

    2012-06-01

    Sandia National Laboratories has the need to predict the behavior of structures after the occurrence of an initial failure. In some cases determining the extent of failure, beyond initiation, is required, while in a few cases the initial failure is a design feature used to tailor the subsequent load paths. In either case, the ability to numerically simulate the initiation and propagation of failures is a highly desired capability. This document describes one approach to the simulation of failure initiation and propagation.

  9. Seismic ratchet-fatigue failure of piping systems

    International Nuclear Information System (INIS)

    Severud, L.K.; Anderson, M.J.; Lindquist, M.R.; Weiner, E.O.

    1986-01-01

    Failures of piping systems during earthquakes have been rare. Those that have failed were either made of brittle material such as cast iron, were rigid systems between major components where component relative seismic motions tore the pipe out of the component, or were high pressure systems where a ratchet-fatigue fracture followed a local bulging of the pipe diameter. Tests to failure of an unpressurized 3-in. and a pressurized 6-in. diameter carbon steel nuclear pipe systems subjected to high level shaking have been accomplished. Failure analyses of these tests are presented and correlated to the test results. It was found that failure of the unpressurized system could be correlated well with standard ASME type fatigue analysis predictions. Moreover, the pressurized system failure occurred in significantly less load cycles than predicted by standard fatigue analysis. However, a ratchet-fatigue and ductility exhaustion analysis of the pressurized system did correlate very well. These findings indicate modifications to design analysis methods and the present ASME Code piping design rules may be appropriate to cover the ratchet-fatigue failure mode

  10. Is there a way to predict failure after direct vision internal urethrotomy for single and short bulbar urethral strictures?

    Science.gov (United States)

    Harraz, Ahmed M; El-Assmy, Ahmed; Mahmoud, Osama; Elbakry, Amr A; Tharwat, Mohamed; Omar, Helmy; Farg, Hashim; Laymon, Mahmoud; Mosbah, Ahmed

    2015-12-01

    To identify patient and stricture characteristics predicting failure after direct vision internal urethrotomy (DVIU) for single and short (urethroplasty. Predictors of failure were analysed. In all, 430 adult patients with a mean (SD) age of 50 (15) years were included. The main causes of stricture were idiopathic followed by iatrogenic in 51.6% and 26.3% of patients, respectively. Most patients presented with obstructive lower urinary tract symptoms (68.9%) and strictures were proximal bulbar, i.e. just close to the external urethral sphincter, in 35.3%. The median (range) follow-up duration was 29 (3-132) months. In all, 250 (58.1%) patients did not require any further instrumentation, while RSD was maintained in 116 (27%) patients, including 28 (6.5%) who required a redo DVIU or urethroplasty. In 64 (6.5%) patients, a redo DVIU or urethroplasty was performed. On multivariate analysis, older age at presentation [odds ratio (OR) 1.017; P = 0.03], obesity (OR 1.664; P = 0.015), and idiopathic strictures (OR 3.107; P = 0.035) were independent predictors of failure after DVIU. The failure rate after DVIU accounted for 41.8% of our present cohort with older age at presentation, obesity, and idiopathic strictures independent predictors of failure after DVIU. This information is important in counselling patients before surgery.

  11. Immediate extubation in cardiac surgery: evaluation using electroencephalogram Extubação imediata em cirurgia cardíaca: avaliação pelo eletroencefalograma

    Directory of Open Access Journals (Sweden)

    Valdester Cavalcante Pinto Jr.

    2003-10-01

    Full Text Available BACKGROUND AND OBJECTIVES:The current techniques of anesthesia employed in cardiac surgery leading to immediate extubation depend on adequate analgesia and titration of anesthetic drugs. We sought to determine the best possible moment of extubation, using the bispectral index of the electroencephalogram. METHOD: Twelve ASA III patients were analyzed. Seven (58.4% were children (Group I, submitted to correction of congenital cardiac defects with ages ranging from 0 to 7 years. Five adults (Group II, with ages ranging from 30 to 75 years, underwent coronary artery bypass grafts. In Group I spinal anesthesia (L5-S1 using hyperbaric 0.5% bupivacaine (0.5mg/kg and morphine (5µg/kg was chosen. In Group II epidural anesthesia (T3-T4 with catheter placement plus ropivacaine (60mg and morphine (2mg were employed. For the induction of anesthesia fentanila (4µg/kg, muscle relaxant and propofol (to bring the bispectral index value down to 30 were utilized. General anesthesia was maintained with sevofluorane, maintaining the bispectral index value between 40 and 60. Extubation was programmed at a bispectral index value of 90. RESULTS: All patients were extubated up to one hour after the end of the surgical procedure, 91.6% of them in the operating room. All had the cognitive functions preserved without history of explicit memory or pain (adults and children who were able to speak, nor facial expression of pain (small children. Four (57% patients in Group I and one (20% in Group II had post-operative pruritus. Two patients (28% in Group II had emesis. CONCLUSIONS: The results suggest that the technique employed is safe and effective, as long as the criteria for its use are strictly observed.INTRODUÇÃO: As técnicas empregadas em cirurgia cardíaca visando a extubação imediata (EI dependem de analgesia adequada e titulação de drogas anestésicas. OBJETIVO: A finalidade deste estudo é analisar a EI, utilizando eletroencefalograma (índice bispectral

  12. The influence of gouge defects on failure pressure of steel pipes

    International Nuclear Information System (INIS)

    Alang, N A; Razak, N A; Zulfadli, M R

    2013-01-01

    Failure pressure of API X42 steel pipes with gouge defects was estimated through a nonlinear finite element (FE) analysis. The effect of gouge length on failure pressure of different pipe diameters was investigated. Stress modified critical strain (SMCS) model was applied as in predicting the failure of the pipe. The model uses strain based criteria to predict the failure. For validation of the model, the FE results were compared to experimental data in literature showing overall good agreement. The results show that the gouge length has significant influence on failure pressure. A smaller pipe diameter gives highest value of failure pressure

  13. The Significance Mild Renal Dysfunction in Chronic Heart Failure ...

    African Journals Online (AJOL)

    BACKGROUND: Heart failure is a major public health concern. Prediction models in heart failure have employed echocardiography and other advanced laboratory parameters in predicting the risk of mortality.However, most of the patients in the resource poor economies still do not have easy access to these advanced ...

  14. Failure Predictions for VHTR Core Components using a Probabilistic Contiuum Damage Mechanics Model

    Energy Technology Data Exchange (ETDEWEB)

    Fok, Alex

    2013-10-30

    The proposed work addresses the key research need for the development of constitutive models and overall failure models for graphite and high temperature structural materials, with the long-term goal being to maximize the design life of the Next Generation Nuclear Plant (NGNP). To this end, the capability of a Continuum Damage Mechanics (CDM) model, which has been used successfully for modeling fracture of virgin graphite, will be extended as a predictive and design tool for the core components of the very high- temperature reactor (VHTR). Specifically, irradiation and environmental effects pertinent to the VHTR will be incorporated into the model to allow fracture of graphite and ceramic components under in-reactor conditions to be modeled explicitly using the finite element method. The model uses a combined stress-based and fracture mechanics-based failure criterion, so it can simulate both the initiation and propagation of cracks. Modern imaging techniques, such as x-ray computed tomography and digital image correlation, will be used during material testing to help define the baseline material damage parameters. Monte Carlo analysis will be performed to address inherent variations in material properties, the aim being to reduce the arbitrariness and uncertainties associated with the current statistical approach. The results can potentially contribute to the current development of American Society of Mechanical Engineers (ASME) codes for the design and construction of VHTR core components.

  15. An analysis of predictive factors for concurrent acute-on-chronic liver failure and hepatorenal syndrome

    Directory of Open Access Journals (Sweden)

    CHEN Yanfang

    2015-09-01

    Full Text Available ObjectiveTo learn the clinical characteristics of concurrent acute-on-chronic liver failure (ACLF and hepatorenal syndrome (HRS, and to investigate the predictive factors for HRS in patients with ACLF. MethodsA total of 806 patients with ACLF who were admitted to our hospital from January 2012 to May 2014 were selected and divided into two groups according to the incidence of concurrent HRS. Clinical indices and laboratory test results were analyzed in the two groups, and the multivariate logistic regression analysis was used to figure out independent indices for the prediction of HRS in patients with ACLF. A prediction model was established and the receiver operating characteristic curve was drawn to evaluate the accuracy of the prediction model. Comparison of continuous data between the two groups was made by t test, and comparison of categorical data between the two groups was made by χ2 test. ResultsIn all patients with ACLF, 229 had HRS and 577 had no HRS. The univariate logistic regression analysis showed that hepatic encephalopathy, peritonitis, infection, age, cystatin C (Cys-C, serum creatinine (SCr, blood urea nitrogen, albumin, prealbumin, total bilirubin, direct bilirubin, total cholesterol, K+, Na+, phosphorus, Ca2+, prothrombin time, prothrombin activity, international normalized ratio, and hematocrit were significant predictive factors for HRS. The multivariate logistic regression analysis showed that concurrent peritonitis, Cys-C, SCr, and HCO3- were independent predictive factors for HRS in patients with ACLF (OR=3.155, P<0.01; OR=30.773, P<0.01; OR=1062, P<0.01; OR=0.915, P<0.05. The model was proved of great value in prediction. ConclusionConcurrent peritonitis, Cys-C, SCr, and HCO3- are effective predictive factors for HRS in patients with ACLF.

  16. RSA prediction of high failure rate for the uncoated Interax TKA confirmed by meta-analysis.

    Science.gov (United States)

    Pijls, Bart G; Nieuwenhuijse, Marc J; Schoones, Jan W; Middeldorp, Saskia; Valstar, Edward R; Nelissen, Rob G H H

    2012-04-01

    In a previous radiostereometric (RSA) trial the uncoated, uncemented, Interax tibial components showed excessive migration within 2 years compared to HA-coated and cemented tibial components. It was predicted that this type of fixation would have a high failure rate. The purpose of this systematic review and meta-analysis was to investigate whether this RSA prediction was correct. We performed a systematic review and meta-analysis to determine the revision rate for aseptic loosening of the uncoated and cemented Interax tibial components. 3 studies were included, involving 349 Interax total knee arthroplasties (TKAs) for the comparison of uncoated and cemented fixation. There were 30 revisions: 27 uncoated and 3 cemented components. There was a 3-times higher revision rate for the uncoated Interax components than that for cemented Interax components (OR = 3; 95% CI: 1.4-7.2). This meta-analysis confirms the prediction of a previous RSA trial. The uncoated Interax components showed the highest migration and turned out to have the highest revision rate for aseptic loosening. RSA appears to enable efficient detection of an inferior design as early as 2 years postoperatively in a small group of patients.

  17. Predictions and Experimental Microstructural Characterization of High Strain Rate Failure Modes in Layered Aluminum Composites

    Science.gov (United States)

    Khanikar, Prasenjit

    Different aluminum alloys can be combined, as composites, for tailored dynamic applications. Most investigations pertaining to metallic alloy layered composites, however, have been based on quasi-static approaches. The dynamic failure of layered metallic composites, therefore, needs to be characterized in terms of strength, toughness, and fracture response. A dislocation-density based crystalline plasticity formulation, finite-element techniques, rational crystallographic orientation relations and a new fracture methodology were used to predict the failure modes associated with the high strain rate behavior of aluminum layered composites. Two alloy layers, a high strength alloy, aluminum 2195, and an aluminum alloy 2139, with high toughness, were modeled with representative microstructures that included precipitates, dispersed particles, and different grain boundary (GB) distributions. The new fracture methodology, based on an overlap method and phantom nodes, is used with a fracture criteria specialized for fracture on different cleavage planes. One of the objectives of this investigation, therefore, was to determine the optimal arrangements of the 2139 and 2195 aluminum alloys for a metallic layered composite that would combine strength, toughness and fracture resistance for high strain-rate applications. Different layer arrangements were investigated for high strain-rate applications, and the optimal arrangement was with the high toughness 2139 layer on the bottom, which provided extensive shear strain localization, and the high strength 2195 layer on the top for high strength resistance. The layer thickness of the bottom high toughness layer also affected the bending behavior of the roll-boned interface and the potential delamination of the layers. Shear strain localization, dynamic cracking and delamination were the mutually competing failure mechanisms for the layered metallic composite, and control of these failure modes can be optimized for high strain

  18. Metallic ureteral stents in malignant ureteral obstruction: short-term results and radiological features predicting stent failure in patients with non-urological malignancies.

    Science.gov (United States)

    Chow, Po-Ming; Hsu, Jui-Shan; Wang, Shuo-Meng; Yu, Hong-Jheng; Pu, Yeong-Shiau; Liu, Kao-Lang

    2014-06-01

    To provide short-term result of the metallic ureteral stent in patients with malignant ureteral obstruction and identify radiological findings predicting stent failure. The records of all patients with non-urological malignant diseases who have received metallic ureteral stents from July 2009 to March 2012 for ureteral obstruction were reviewed. Stent failure was detected by clinical symptoms and imaging studies. Survival analysis was used to estimate patency rates and factors predicting stent failure. A total of 74 patients with 130 attempts of stent insertion were included. A total of 113 (86.9 %) stents were inserted successfully and 103 (91.2 %) achieved primary patency. After excluding cases without sufficient imaging data, 94 stents were included in the survival analysis. The median functional duration of the 94 stents was 6.2 months (range 3-476 days). Obstruction in abdominal ureter (p = 0.0279) and lymphatic metastasis around ureter (p = 0.0398) were risk factors for stent failure. The median functional durations of the stents for abdominal and pelvic obstructions were 4.5 months (range 3-263 days) and 6.5 months (range 4-476 days), respectively. The median durations of the stents with and without lymphatic metastasis were 5.3 months (range 4-398 days) and 7.8 months (range 31-476 days), respectively. Metallic ureteral stents are effective and safe in relieving ureteral obstructions resulting from non-urological malignancies, and abdominal ureteral obstruction and lymphatic metastasis around ureter were associated with shorter functional duration.

  19. Antithrombin III is associated with acute liver failure in patients with end-stage heart failure undergoing mechanical circulatory support.

    Science.gov (United States)

    Hoefer, Judith; Ulmer, Hanno; Kilo, Juliane; Margreiter, Raimund; Grimm, Michael; Mair, Peter; Ruttmann, Elfriede

    2017-06-01

    There are few data on the role of liver dysfunction in patients with end-stage heart failure supported by mechanical circulatory support. The aim of our study was to investigate predictors for acute liver failure in patients with end-stage heart failure undergoing mechanical circulatory support. A consecutive 164 patients with heart failure with New York Heart Association class IV undergoing mechanical circulatory support were investigated for acute liver failure using the King's College criteria. Clinical characteristics of heart failure together with hemodynamic and laboratory values were analyzed by logistic regression. A total of 45 patients (27.4%) with heart failure developed subsequent acute liver failure with a hospital mortality of 88.9%. Duration of heart failure, cause, cardiopulmonary resuscitation, use of vasopressors, central venous pressure, pulmonary capillary wedge pressure, pulmonary pulsatility index, cardiac index, and transaminases were not significantly associated with acute liver failure. Repeated decompensation, atrial fibrillation (P failure in univariate analysis only. In multivariable analysis, decreased antithrombin III was the strongest single measurement indicating acute liver failure (relative risk per %, 0.84; 95% confidence interval, 0.77-0.93; P = .001) and remained an independent predictor when adjustment for the Model for End-Stage Liver Disease score was performed (relative risk per %, 0.89; 95% confidence interval, 0.80-0.99; P = .031). Antithrombin III less than 59.5% was identified as a cutoff value to predict acute liver failure with a corresponding sensitivity of 81% and specificity of 87%. In addition to the Model for End-Stage Liver Disease score, decreased antithrombin III activity tends to be superior in predicting acute liver failure compared with traditionally thought predictors. Antithrombin III measurement may help to identify patients more precisely who are developing acute liver failure during mechanical

  20. Cannabis use predicts risks of heart failure and cerebrovascular accidents: results from the National Inpatient Sample.

    Science.gov (United States)

    Kalla, Aditi; Krishnamoorthy, Parasuram M; Gopalakrishnan, Akshaya; Figueredo, Vincent M

    2018-06-06

    Cannabis for medicinal and/or recreational purposes has been decriminalized in 28 states as of the 2016 election. In the remaining states, cannabis remains the most commonly used illicit drug. Cardiovascular effects of cannabis use are not well established due to a limited number of studies. We therefore utilized a large national database to examine the prevalence of cardiovascular risk factors and events amongst patients with cannabis use. Patients aged 18-55 years with cannabis use were identified in the National Inpatient Sample 2009-2010 database using the Ninth Revision of International Classification of Disease code 304.3. Demographics, risk factors, and cardiovascular event rates were collected on these patients and compared with general population data. Prevalence of heart failure, cerebrovascular accident (CVA), coronary artery disease, sudden cardiac death, and hypertension were significantly higher in patients with cannabis use. After multivariate regression adjusting for age, sex, hypertension, diabetes mellitus, hyperlipidemia, coronary artery disease, tobacco use, and alcohol use, cannabis use remained an independent predictor of both heart failure (odds ratio = 1.1, 1.03-1.18, P < 0.01) and CVA (odds ratio = 1.24, 1.14-1.34, P < 0.001). Cannabis use independently predicted the risks of heart failure and CVA in individuals 18-55 years old. With continued legalization of cannabis, potential cardiovascular effects and their underlying mechanisms need to be further investigated.

  1. A Novel Risk Score in Predicting Failure or Success for Antegrade Approach to Percutaneous Coronary Intervention of Chronic Total Occlusion: Antegrade CTO Score.

    Science.gov (United States)

    Namazi, Mohammad Hasan; Serati, Ali Reza; Vakili, Hosein; Safi, Morteza; Parsa, Saeed Ali Pour; Saadat, Habibollah; Taherkhani, Maryam; Emami, Sepideh; Pedari, Shamseddin; Vatanparast, Masoomeh; Movahed, Mohammad Reza

    2017-06-01

    Total occlusion of a coronary artery for more than 3 months is defined as chronic total occlusion (CTO). The goal of this study was to develop a risk score in predicting failure or success during attempted percutaneous coronary intervention (PCI) of CTO lesions using antegrade approach. This study was based on retrospective analyses of clinical and angiographic characteristics of CTO lesions that were assessed between February 2012 and February 2014. Success rate was defined as passing through occlusion with successful stent deployment using an antegrade approach. A total of 188 patients were studied. Mean ± SD age was 59 ± 9 years. Failure rate was 33%. In a stepwise multivariate regression analysis, bridging collaterals (OR = 6.7, CI = 1.97-23.17, score = 2), absence of stump (OR = 5.8, CI = 1.95-17.9, score = 2), presence of calcification (OR = 3.21, CI = 1.46-7.07, score = 1), presence of bending (OR = 2.8, CI = 1.28-6.10, score = 1), presence of near side branch (OR = 2.7, CI = 1.08-6.57, score = 1), and absence of retrograde filling (OR = 2.5, CI = 1.03-6.17, score = 1) were independent predictors of PCI failure. A score of 7 or more was associated with 100% failure rate whereas a score of 2 or less was associated with over 80% success rate. Most factors associated with failure of CTO-PCI are related to lesion characteristics. A new risk score (range 0-8) is developed to predict CTO-PCI success or failure rate during antegrade approach as a guide before attempting PCI of CTO lesions.

  2. Verification tests for GRAD, a computer program to predict nonuniform deformation and failure of Zr-2.5 wt percent Nb pressure tubes during a postulated loss-of-coolant accident

    International Nuclear Information System (INIS)

    Shewfelt, R.S.W.; Godin, D.P.

    1985-03-01

    During a postulated loss-of-coolant accident in a CANDU reactor, the temperature of the pressure tubes could rise sufficiently so that ballooning could occur. It is also likely that there would be a variation in temperature around the tube circumference, causing the deformation to be nonuniform. Since the deformation of the pressure tube controls how the core heat is transferred to the surrounding moderator, which is a large heat sink, a computer program, GRAD, has been developed to predict this nonuniform deformation. Numerous biaxial creep tests were done, where the temperature of internally pressurized sections of Zr-2.5 wt percent Nb pressure tubes were ramped to check the ability of GRAD to predict the resulting nonuniform deformation and possible tube failure. GRAD was successful in predicting the average transverse creep strain observed during the tests and the local transverse creep strain at the end of the tests. GRAD was also able to predict the failure time and average transverse creep strain at failure for all the specimens that failed

  3. Predictive factors for early failure of transarterial embolization in blunt hepatic injury patients

    International Nuclear Information System (INIS)

    Lee, Y.-H.; Wu, C.-H.; Wang, L.-J.; Wong, Y.-C.; Chen, H.-W.; Wang, C.-J.; Lin, B.-C.; Hsu, Y.-P.

    2014-01-01

    Aim: To evaluate the early success of transarterial embolization (TAE) in patients with traumatic liver haemorrhage and to determine independent factors for its failure. Materials and methods: From January 2009 to December 2012, TAE was performed in 48 patients for traumatic liver haemorrhage. Their medical charts were reviewed for demographic information, pre-TAE vital signs and laboratory data, injury grade, type of contrast medium extravasation (CME) at CT, angiography findings, and early failure. “Early failure” was defined as the need for repeated TAE or a laparotomy for hepatic haemorrhage within 4 days after TAE. Variables were compared between the early success and early failure groups. Variables with univariate significance were also analysed using multivariate logistic regression for predictors of early failure. Results: Among 48 liver TAE cases, nine (18.8%) were early failures due to liver haemorrhage. Early failure was associated with injury grade (p = 0.039), major liver injury (grades 4 and 5; p = 0.007), multiple CMEs at angiography (p = 0.031), incomplete TAE (p = 0.002), and elevated heart rate (p = 0.026). Incomplete embolization (OR = 8; p = 0.042), and heart rate >110 beats/min (bpm; OR = 8; p = 0.05) were independent factors for early failure of TAE in the group with major liver injuries. Conclusion: Major hepatic injury is an important factor in early failure. Patients with a heart rate >110 bpm and incomplete embolization in the major injury group have an increased rate of early failure. The success rate of proximal TAE was comparable to that of the more time-consuming, superselective, distal TAE. - Highlights: • Early failure of TAE is associated with a higher grade of liver injury. • Incomplete embolization is more likely to suffer early failure of TAE. • A heart rate greater than 110 bpm is more likely to suffer early failure of TAE. • We recommend proximal embolization to prevent early failure of TAE

  4. Predicting the success of noninvasive positive pressure ventilation in emergency room for patients with acute heart failure.

    Science.gov (United States)

    Shirakabe, Akihiro; Hata, Noritake; Yokoyama, Shinya; Shinada, Takuro; Kobayashi, Nobuaki; Tomita, Kazunori; Kitamura, Mitsunobu; Nozaki, Ayaka; Tokuyama, Hideo; Asai, Kuniya; Mizuno, Kyoichi

    2011-01-01

    Non-invasive positive pressure ventilation (NPPV) for acute heart failure (AHF) is increasingly used to avoid endotracheal intubation (ETI). We therefore reviewed our experience using respirator management in the emergency room for AHF, and evaluated the predictive factors in the success of NPPV in the emergency room. Three-hundred forty-three patients with AHF were analyzed. The AHF patients were assigned to either BiPAP-Synchrony (B-S; Respironics, Merrysville, PA, USA) period (2005-2007, n = 176) or BiPAP-Vision (B-V; Respironics) period (2008-2010, n = 167). The rate of carperitide use was significantly increased and dopamine use was significantly decreased in the B-V period. The total length of hospital stay was significantly shorter in the B-V period. AHF patients were also assigned to a failed trial of NPPV followed by ETI (NPPV failure group) or an NPPV success group in the emergency room for each period. NPPV was successfully used in 48 cases in the B-S period, and in 111 cases in the B-V period. Fifty-seven ETI patients included 45 direct ETI and 11 NPPV failure cases in the B-S period, and 16 ETI patients included 10 direct ETI and 6 NPPV failure cases in the B-V period. The pH values were significantly lower in the NPPV failure than in the NPPV success for both periods (7.19 ± 0.10 vs. 7.28 ± 0.11, B-S period, p successful estimates of NPPV with a high sensitivity and specificity, and the aortic blood gas level was above 7.03 pH when using the B-V system. Copyright © 2011 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  5. Seismic ratchet-fatigue failure of piping systems

    International Nuclear Information System (INIS)

    Severud, L.K.; Anderson, M.J.; Lindquist, M.R.; Weiner, E.O.

    1987-01-01

    Failures of piping systems during earthquakes have been rare. Those that have failed were either made of brittle material such as cast iron, were rigid systems between major components where component relative seismic motions tore the pipe out of the component, or were high pressure systems where a ratchet-fatigue fracture followed a local bulging of the pipe diameter. Tests to failure of an unpressurized 3-inch and a pressurized 6-inch diameter carbon steel nuclear pipe systems subjected to high-level shaking have been accomplished. The high-level shaking loads needed to cause failure were much higher than ASME Code rules would permit with present design limits. Failure analyses of these tests are presented and correlated to the test results. It was found that failure of the unpressurized system could be correlated well with standard ASME type fatigue analysis predictions. Moreover, the pressurized system failure occured in significantly less load cycles than predicted by standard fatigue analysis. However, a ratchet-fatigue and ductility exhaustion analysis of the pressurized system did correlate reasonably well. These findings indicate modifications to design analysis methods and the present ASME Code piping design rules to reduce unneeded conservatisms and to cover the ratchet-fatigue failure mode may be appropriate

  6. Accuracy of a heart failure diagnosis in administrative registers

    DEFF Research Database (Denmark)

    Kümler, Thomas; Gislason, Gunnar Hilmar; Kirk, Vibeke

    2008-01-01

    BACKGROUND: The incidence of heart failure is frequently reported using hospital discharge diagnoses. The specificity of a diagnosis has been shown to be high but the sensitivity of a reported diagnosis is unknown. PURPOSE: To study the accuracy of a heart failure diagnosis reported to the Danish...... a specificity of 99% and a sensitivity of 29% for all patients. The positive predictive value was 81%, the negative predictive value 90%. CONCLUSION: The diagnosis of Heart Failure in the Danish National Registers is underreported, but very specific....

  7. Immunohistochemical and molecular imaging biomarker signature for the prediction of failure site after chemoradiation for head and neck squamous cell carcinoma

    DEFF Research Database (Denmark)

    Rasmussen, Gregers Brünnich; Håkansson, Katrin E; Vogelius, Ivan R

    2017-01-01

    .23; p: .025), Bcl-2 (HR: 2.6; p: .08), SUVmax (HR: 3.5; p: .095) and GTV (HR: 1.7; p: .063). CONCLUSIONS: The models successfully distinguished between risk of locoregional failure and risk of distant metastasis, which is important information for clinical decision-making. High p53 expression has......OBJECTIVE: To identify a failure site-specific prognostic model by combining immunohistochemistry (IHC) and molecular imaging information to predict long-term failure type in squamous cell carcinoma of the head and neck. PATIENT AND METHODS: Tissue microarray blocks of 196 head and neck squamous...... cell carcinoma cases were stained for a panel of biomarkers using IHC. Gross tumor volume (GTV) from the PET/CT radiation treatment planning CT scan, maximal Standard Uptake Value (SUVmax) of fludeoxyglucose (FDG) and clinical information were included in the model building using Cox proportional...

  8. Plasma copeptin levels and prediction of outcome in heart failure outpatients

    DEFF Research Database (Denmark)

    Balling, Louise; Kistorp, Caroline; Schou, Morten

    2012-01-01

    Copeptin, a stable fragment of the vasopressin prohormone, has been shown to be a significant biomarker for morbidity and mortality in heart failure. The aims of this study were to evaluate the influence of plasma sodium on the prognostic significance of copeptin concentrations in heart failure o...

  9. Numerical investigations of rib fracture failure models in different dynamic loading conditions.

    Science.gov (United States)

    Wang, Fang; Yang, Jikuang; Miller, Karol; Li, Guibing; Joldes, Grand R; Doyle, Barry; Wittek, Adam

    2016-01-01

    Rib fracture is one of the most common thoracic injuries in vehicle traffic accidents that can result in fatalities associated with seriously injured internal organs. A failure model is critical when modelling rib fracture to predict such injuries. Different rib failure models have been proposed in prediction of thorax injuries. However, the biofidelity of the fracture failure models when varying the loading conditions and the effects of a rib fracture failure model on prediction of thoracic injuries have been studied only to a limited extent. Therefore, this study aimed to investigate the effects of three rib failure models on prediction of thoracic injuries using a previously validated finite element model of the human thorax. The performance and biofidelity of each rib failure model were first evaluated by modelling rib responses to different loading conditions in two experimental configurations: (1) the three-point bending on the specimen taken from rib and (2) the anterior-posterior dynamic loading to an entire bony part of the rib. Furthermore, the simulation of the rib failure behaviour in the frontal impact to an entire thorax was conducted at varying velocities and the effects of the failure models were analysed with respect to the severity of rib cage damages. Simulation results demonstrated that the responses of the thorax model are similar to the general trends of the rib fracture responses reported in the experimental literature. However, they also indicated that the accuracy of the rib fracture prediction using a given failure model varies for different loading conditions.

  10. Detecting virological failure in HIVinfected Tanzanian children ...

    African Journals Online (AJOL)

    Background. The performance of clinical and immunological criteria to predict virological failure in HIV-infected children receiving antiretroviral therapy (ART) is not well documented. Objective. To determine the validity of clinical and immunological monitoring in detecting virological failure in children on ART. Methods.

  11. Depression increasingly predicts mortality in the course of congestive heart failure.

    Science.gov (United States)

    Jünger, Jana; Schellberg, Dieter; Müller-Tasch, Thomas; Raupp, Georg; Zugck, Christian; Haunstetter, Armin; Zipfel, Stephan; Herzog, Wolfgang; Haass, Markus

    2005-03-02

    Congestive heart failure (CHF) is frequently associated with depression. However, the impact of depression on prognosis has not yet been sufficiently established. To prospectively investigate the influence of depression on mortality in patients with CHF. In 209 CHF patients depression was assessed by the Hospital Anxiety and Depression Scale (HADS-D). Compared to survivors (n=164), non-survivors (n=45) were characterized by a higher New York Heart Association (NYHA) functional class (2.8+/-0.7 vs. 2.5+/-0.6), and a lower left ventricular ejection fraction (LVEF) (18+/-8 vs. 23+/-10%) and peakVO(2) (13.1+/-4.5 vs. 15.4+/-5.2 ml/kg/min) at baseline. Furthermore, non-survivors had a higher depression score (7.5+/-4.0 vs. 6.1+/-4.3) (all P<0.05). After a mean follow-up of 24.8 months the depression score was identified as a significant indicator of mortality (P<0.01). In multivariate analysis the depression score predicted mortality independent from NYHA functional class, LVEF and peakVO(2). Combination of depression score, LVEF and peakVO(2) allowed for a better risk stratification than combination of LVEF and peakVO(2) alone. The risk ratio for mortality in patients with an elevated depression score (i.e. above the median) rose over time to 8.2 after 30 months (CI 2.62-25.84). The depression score predicts mortality independent of somatic parameters in CHF patients not treated for depression. Its prognostic power increases over time and should, thus, be accounted for in risk stratification and therapy.

  12. Patient Characteristics Predicting Readmission Among Individuals Hospitalized for Heart Failure.

    Science.gov (United States)

    O'Connor, Melissa; Murtaugh, Christopher M; Shah, Shivani; Barrón-Vaya, Yolanda; Bowles, Kathryn H; Peng, Timothy R; Zhu, Carolyn W; Feldman, Penny H

    2016-02-01

    Heart failure is difficult to manage and increasingly common with many individuals experiencing frequent hospitalizations. Little is known about patient factors consistently associated with hospital readmission. A literature review was conducted to identify heart failure patient characteristics, measured before discharge, that contribute to variation in hospital readmission rates. Database searches yielded 950 potential articles, of which 34 studies met inclusion criteria. Patient characteristics generally have a very modest effect on all-cause or heart failure-related readmission within 7 to 180 days of index hospital discharge. A range of cardiac diseases and other comorbidities only minimally increase readmission rates. No single patient characteristic stands out as a key contributor across multiple studies underscoring the challenge of developing successful interventions to reduce readmissions. Interventions may need to be general in design with the specific intervention depending on each patient's unique clinical profile. © The Author(s) 2015.

  13. Failure analysis of bolted joints in foam-core sandwich composites

    DEFF Research Database (Denmark)

    Zabihpoor, M.; Moslemian, Ramin; Afshin, M.

    2008-01-01

    This study represents an effort to predict the bearing strength, failure modes, and failure load of bolted joints in foam-core sandwich composites. The studied joints have been used in a light full composite airplane. By using solid laminates, a new design for the joint zone is developed. These s......This study represents an effort to predict the bearing strength, failure modes, and failure load of bolted joints in foam-core sandwich composites. The studied joints have been used in a light full composite airplane. By using solid laminates, a new design for the joint zone is developed...

  14. Acceleration Test Method for Failure Prediction of the End Cap Contact Region of Sodium Cooled Fast Reactor Fuel Rod

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung-Kyu; Lee, Young-Ho; Lee, Hyun-Seung; Lee, Kang-Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-05-15

    This paper reports the results of an acceleration test to predict the contact-induced failure that could occur at the cylinder-to-hole joint for the fuel rod of a sodium-cooled fast reactor (SFR). To incorporate the fuel life of the SFR currently under development at KAERI (around 35,000 h), the acceleration test method of reliability engineering was adopted in this work. A finite element method was used to evaluate the flow-induced vibration frequency and amplitude for the test parameter values. Five specimens were tested. The failure criterion during the life of the SFR fuel was applied. The S-N curve of the HT-9, the material of concern, was used to obtain the acceleration factor. As a result, a test time of 16.5 h was obtained for each specimen. It was concluded that the B{sub 0.004} life would be guaranteed for the SFR fuel rods with 99% confidence if no failure was observed at any of the contact surfaces of the five specimens.

  15. Patency of Femoral Tunneled Hemodialysis Catheters and Factors Predictive of Patency Failure

    International Nuclear Information System (INIS)

    Burton, Kirsteen R.; Guo, Lancia L. Q.; Tan, Kong T.; Simons, Martin E.; Sniderman, Kenneth W.; Kachura, John R.; Beecroft, John R.; Rajan, Dheeraj K.

    2012-01-01

    Purpose: To determine the patency rates of and factors associated with increased risk of patency failure in patients with femoral vein tunneled hemodialysis catheters. Methods: All femoral tunneled catheter insertions from 1996 to 2006 were reviewed, during which time 123 catheters were inserted. Of these, 66 were exchanges. Patients with femoral catheter failure versus those with femoral catheter patency were compared. Confounding factors, such as demographic and procedural factors, were incorporated and assessed using univariate and multivariable Cox proportional hazards regression analyses. Results: Mean catheter primary patency failure time was 96.3 days (SE 17.9 days). Primary patency at 30, 60, 90, and 180 days was 53.8%, 45.4%, 32.1%, and 27.1% respectively. Crude rates of risk of catheter failure did not suggest a benefit for patients receiving catheters introduced from one side versus the other, but more cephalad location of catheter tip was associated with improved patency. Multivariate analysis showed that patients whose catheters were on the left side (p = 0.009), were of increasing age at the time of insertion (p = 0.002) and that those who had diabetes (p = 0.001) were at significantly greater risk of catheter failure. The catheter infection rate was 1.4/1000 catheter days. Conclusion: Patients who were of a more advanced age and had diabetes were at greater risk of femoral catheter failure, whereas those who received femoral catheters from the right side were less at risk of catheter failure.

  16. Failure-probability driven dose painting

    International Nuclear Information System (INIS)

    Vogelius, Ivan R.; Håkansson, Katrin; Due, Anne K.; Aznar, Marianne C.; Kristensen, Claus A.; Rasmussen, Jacob; Specht, Lena; Berthelsen, Anne K.; Bentzen, Søren M.

    2013-01-01

    Purpose: To demonstrate a data-driven dose-painting strategy based on the spatial distribution of recurrences in previously treated patients. The result is a quantitative way to define a dose prescription function, optimizing the predicted local control at constant treatment intensity. A dose planning study using the optimized dose prescription in 20 patients is performed.Methods: Patients treated at our center have five tumor subvolumes from the center of the tumor (PET positive volume) and out delineated. The spatial distribution of 48 failures in patients with complete clinical response after (chemo)radiation is used to derive a model for tumor control probability (TCP). The total TCP is fixed to the clinically observed 70% actuarial TCP at five years. Additionally, the authors match the distribution of failures between the five subvolumes to the observed distribution. The steepness of the dose–response is extracted from the literature and the authors assume 30% and 20% risk of subclinical involvement in the elective volumes. The result is a five-compartment dose response model matching the observed distribution of failures. The model is used to optimize the distribution of dose in individual patients, while keeping the treatment intensity constant and the maximum prescribed dose below 85 Gy.Results: The vast majority of failures occur centrally despite the small volumes of the central regions. Thus, optimizing the dose prescription yields higher doses to the central target volumes and lower doses to the elective volumes. The dose planning study shows that the modified prescription is clinically feasible. The optimized TCP is 89% (range: 82%–91%) as compared to the observed TCP of 70%.Conclusions: The observed distribution of locoregional failures was used to derive an objective, data-driven dose prescription function. The optimized dose is predicted to result in a substantial increase in local control without increasing the predicted risk of toxicity

  17. Semiconductor failure threshold estimation problem in electromagnetic assessment

    International Nuclear Information System (INIS)

    Enlow, E.W.; Wunsch, D.C.

    1984-01-01

    Present semiconductor failure models to predict the one-microsecond square-wave power failure level for use with system electromagnetic (EM) assessments and hardening design are incomplete. This is because for a majority of device types there is insufficient data readily available in a composite data source to quantify the model parameters and the inaccuracy of the models cause complications in definition of adequate hardness margins and quantification of EM performance. This paper presents new semiconductor failure models which use a generic approach that are an integration and simplification of many present models. This generic approach uses two categorical models: one for diodes and transistors, and one for integrated circuits. The models were constructed from a large database of semiconductor failure data. The approach used for constructing diode and transistor failure level models is based on device rated power and are simple to use and universally applicable. The model predicts the value of the 1 μ second failure power to be used in the power failure models P = Kt /SUP -1/2/ or P = K 1 t -1 + K 2 t /SUP -1/2/ + K 3

  18. Color Shift Failure Prediction for Phosphor-Converted White LEDs by Modeling Features of Spectral Power Distribution with a Nonlinear Filter Approach

    Directory of Open Access Journals (Sweden)

    Jiajie Fan

    2017-07-01

    Full Text Available With the expanding application of light-emitting diodes (LEDs, the color quality of white LEDs has attracted much attention in several color-sensitive application fields, such as museum lighting, healthcare lighting and displays. Reliability concerns for white LEDs are changing from the luminous efficiency to color quality. However, most of the current available research on the reliability of LEDs is still focused on luminous flux depreciation rather than color shift failure. The spectral power distribution (SPD, defined as the radiant power distribution emitted by a light source at a range of visible wavelength, contains the most fundamental luminescence mechanisms of a light source. SPD is used as the quantitative inference of an LED’s optical characteristics, including color coordinates that are widely used to represent the color shift process. Thus, to model the color shift failure of white LEDs during aging, this paper first extracts the features of an SPD, representing the characteristics of blue LED chips and phosphors, by multi-peak curve-fitting and modeling them with statistical functions. Then, because the shift processes of extracted features in aged LEDs are always nonlinear, a nonlinear state-space model is then developed to predict the color shift failure time within a self-adaptive particle filter framework. The results show that: (1 the failure mechanisms of LEDs can be identified by analyzing the extracted features of SPD with statistical curve-fitting and (2 the developed method can dynamically and accurately predict the color coordinates, correlated color temperatures (CCTs, and color rendering indexes (CRIs of phosphor-converted (pc-white LEDs, and also can estimate the residual color life.

  19. Color Shift Failure Prediction for Phosphor-Converted White LEDs by Modeling Features of Spectral Power Distribution with a Nonlinear Filter Approach.

    Science.gov (United States)

    Fan, Jiajie; Mohamed, Moumouni Guero; Qian, Cheng; Fan, Xuejun; Zhang, Guoqi; Pecht, Michael

    2017-07-18

    With the expanding application of light-emitting diodes (LEDs), the color quality of white LEDs has attracted much attention in several color-sensitive application fields, such as museum lighting, healthcare lighting and displays. Reliability concerns for white LEDs are changing from the luminous efficiency to color quality. However, most of the current available research on the reliability of LEDs is still focused on luminous flux depreciation rather than color shift failure. The spectral power distribution (SPD), defined as the radiant power distribution emitted by a light source at a range of visible wavelength, contains the most fundamental luminescence mechanisms of a light source. SPD is used as the quantitative inference of an LED's optical characteristics, including color coordinates that are widely used to represent the color shift process. Thus, to model the color shift failure of white LEDs during aging, this paper first extracts the features of an SPD, representing the characteristics of blue LED chips and phosphors, by multi-peak curve-fitting and modeling them with statistical functions. Then, because the shift processes of extracted features in aged LEDs are always nonlinear, a nonlinear state-space model is then developed to predict the color shift failure time within a self-adaptive particle filter framework. The results show that: (1) the failure mechanisms of LEDs can be identified by analyzing the extracted features of SPD with statistical curve-fitting and (2) the developed method can dynamically and accurately predict the color coordinates, correlated color temperatures (CCTs), and color rendering indexes (CRIs) of phosphor-converted (pc)-white LEDs, and also can estimate the residual color life.

  20. Human oocyte calcium analysis predicts the response to assisted oocyte activation in patients experiencing fertilization failure after ICSI.

    Science.gov (United States)

    Ferrer-Buitrago, M; Dhaenens, L; Lu, Y; Bonte, D; Vanden Meerschaut, F; De Sutter, P; Leybaert, L; Heindryckx, B

    2018-01-10

    Can human oocyte calcium analysis predict fertilization success after assisted oocyte activation (AOA) in patients experiencing fertilization failure after ICSI? ICSI-AOA restores the fertilization rate only in patients displaying abnormal Ca2+ oscillations during human oocyte activation. Patients capable of activating mouse oocytes and who showed abnormal Ca2+ profiles after mouse oocyte Ca2+ analysis (M-OCA), have variable responses to ICSI-AOA. It remains unsettled whether human oocyte Ca2+ analysis (H-OCA) would yield an improved accuracy to predict fertilization success after ICSI-AOA. Sperm activation potential was first evaluated by MOAT. Subsequently, Ca2+ oscillatory patterns were determined with sperm from patients showing moderate to normal activation potential based on the capacity of human sperm to generate Ca2+ responses upon microinjection in mouse and human oocytes. Altogether, this study includes a total of 255 mouse and 122 human oocytes. M-OCA was performed with 16 different sperm samples before undergoing ICSI-AOA treatment. H-OCA was performed for 11 patients who finally underwent ICSI-AOA treatment. The diagnostic accuracy to predict fertilization success was calculated based on the response to ICSI-AOA. Patients experiencing low or total failed fertilization after conventional ICSI were included in the study. All participants showed moderate to high rates of activation after MOAT. Metaphase II (MII) oocytes from B6D2F1 mice were used for M-OCA. Control fertile sperm samples were used to obtain a reference Ca2+ oscillation profile elicited in human oocytes. Donated human oocytes, non-suitable for IVF treatments, were collected and vitrified at MII stage for further analysis by H-OCA. M-OCA and H-OCA predicted the response to ICSI-AOA in 8 out of 11 (73%) patients. Compared to M-OCA, H-OCA detected the presence of sperm activation deficiencies with greater sensitivity (75 vs 100%, respectively). ICSI-AOA never showed benefit to overcome

  1. Identifying Clinical Factors Which Predict for Early Failure Patterns Following Resection for Pancreatic Adenocarcinoma in Patients Who Received Adjuvant Chemotherapy Without Chemoradiation.

    Science.gov (United States)

    Walston, Steve; Salloum, Joseph; Grieco, Carmine; Wuthrick, Evan; Diaz, Dayssy A; Barney, Christian; Manilchuk, Andrei; Schmidt, Carl; Dillhoff, Mary; Pawlik, Timothy M; Williams, Terence M

    2018-05-04

    The role of radiation therapy (RT) in resected pancreatic cancer (PC) remains incompletely defined. We sought to determine clinical variables which predict for local-regional recurrence (LRR) to help select patients for adjuvant RT. We identified 73 patients with PC who underwent resection and adjuvant gemcitabine-based chemotherapy alone. We performed detailed radiologic analysis of first patterns of failure. LRR was defined as recurrence of PC within standard postoperative radiation volumes. Univariate analyses (UVA) were conducted using the Kaplan-Meier method and multivariate analyses (MVA) utilized the Cox proportional hazard ratio model. Factors significant on UVA were used for MVA. At median follow-up of 20 months, rates of local-regional recurrence only (LRRO) were 24.7%, LRR as a component of any failure 68.5%, metastatic recurrence (MR) as a component of any failure 65.8%, and overall disease recurrence (OR) 90.5%. On UVA, elevated postoperative CA 19-9 (>90 U/mL), pathologic lymph node positive (pLN+) disease, and higher tumor grade were associated with increased LRR, MR, and OR. On MVA, elevated postoperative CA 19-9 and pLN+ were associated with increased MR and OR. In addition, positive resection margin was associated with increased LRRO on both UVA and MVA. About 25% of patients with PC treated without adjuvant RT develop LRRO as initial failure. The only independent predictor of LRRO was positive margin, while elevated postoperative CA 19-9 and pLN+ were associated with predicting MR and overall survival. These data may help determine which patients benefit from intensification of local therapy with radiation.

  2. Fuel-pin cladding transient failure strain criterion

    International Nuclear Information System (INIS)

    Bard, F.E.; Duncan, D.R.; Hunter, C.W.

    1983-01-01

    A criterion for cladding failure based on accumulated strain was developed for mixed uranium-plutonium oxide fuel pins and used to interpret the calculated strain results from failed transient fuel pin experiments conducted in the Transient Reactor Test (TREAT) facility. The new STRAIN criterion replaced a stress-based criterion that depends on the DORN parameter and that incorrectly predicted fuel pin failure for transient tested fuel pins. This paper describes the STRAIN criterion and compares its prediction with those of the stress-based criterion

  3. Micromechanics Based Failure Analysis of Heterogeneous Materials

    Science.gov (United States)

    Sertse, Hamsasew M.

    In recent decades, heterogeneous materials are extensively used in various industries such as aerospace, defense, automotive and others due to their desirable specific properties and excellent capability of accumulating damage. Despite their wide use, there are numerous challenges associated with the application of these materials. One of the main challenges is lack of accurate tools to predict the initiation, progression and final failure of these materials under various thermomechanical loading conditions. Although failure is usually treated at the macro and meso-scale level, the initiation and growth of failure is a complex phenomena across multiple scales. The objective of this work is to enable the mechanics of structure genome (MSG) and its companion code SwiftComp to analyze the initial failure (also called static failure), progressive failure, and fatigue failure of heterogeneous materials using micromechanics approach. The initial failure is evaluated at each numerical integration point using pointwise and nonlocal approach for each constituent of the heterogeneous materials. The effects of imperfect interfaces among constituents of heterogeneous materials are also investigated using a linear traction-displacement model. Moreover, the progressive and fatigue damage analyses are conducted using continuum damage mechanics (CDM) approach. The various failure criteria are also applied at a material point to analyze progressive damage in each constituent. The constitutive equation of a damaged material is formulated based on a consistent irreversible thermodynamics approach. The overall tangent modulus of uncoupled elastoplastic damage for negligible back stress effect is derived. The initiation of plasticity and damage in each constituent is evaluated at each numerical integration point using a nonlocal approach. The accumulated plastic strain and anisotropic damage evolution variables are iteratively solved using an incremental algorithm. The damage analyses

  4. Secondary Circulating Prostate Cells Predict Biochemical Failure in Prostate Cancer Patients after Radical Prostatectomy and without Evidence of Disease

    Directory of Open Access Journals (Sweden)

    Nigel P. Murray

    2013-01-01

    Full Text Available Introduction. Although 90% of prostate cancer is considered to be localized, 20%–30% of patients will experience biochemical failure (BF, defined as serum PSA >0.2 ng/mL, after radical prostatectomy (RP. The presence of circulating prostate cells (CPCs in men without evidence of BF may be useful to predict patients at risk for BF. We describe the frequency of CPCs detected after RP, relation with clinicopathological parameters, and association with biochemical failure. Methods and Patients. Serial blood samples were taken during followup after RP, mononuclear cells were obtained by differential gel centrifugation, and CPCs identified using standard immunocytochemistry using anti-PSA monoclonal antibodies. Age, pathological stage (organ confined, nonorgan confined, pathological grade, margin status (positive, negative, extracapsular extension, perineural, vascular, and lymphatic infiltration (positive, negative were compared with the presence/absence of CPCs and with and without biochemical failure. Kaplan Meier methods were used to compare the unadjusted biochemical failure free survival of patients with and without CPCs. Results. 114 men participated, and secondary CPCs were detected more frequently in patients with positive margins, extracapsular extension, and vascular and lymphatic infiltration and were associated with biochemical failure independent of these clinicopathological variables, and with a shorter time to BF. Conclusions. Secondary CPCs are an independent risk factor associated with increased BF in men with a PSA <0.2 ng/mL after radical prostatectomy, but do not determine if the recurrence is due to local or systemic disease. These results warrant larger studies to confirm the findings.

  5. Of cuts and cracks: data analytics on constrained graphs for early prediction of failure in cementitious materials

    Directory of Open Access Journals (Sweden)

    Kahagalage Sanath

    2017-01-01

    Full Text Available Using data from discrete element simulations, we develop a data analytics approach using network flow theory to study force transmission and failure in a ‘dog-bone’ concrete specimen submitted to uniaxial tension. With this approach, we establish the extent to which the bottlenecks, i.e., a subset of contacts that impedes flow and are prone to becoming overloaded, can predict the location of the ultimate macro-crack. At the heart of this analysis is a capacity function that quantifies, in relative terms, the maximum force that can be transmitted through the different contacts or edges in the network. Here we set this function to be solely governed by the size of the contact area between the deformable spherical grains. During all the initial stages of the loading history, when no bonds are broken, we find the bottlenecks coincide consistently with, and therefore predict, the location of the crack that later forms in the failure regime after peak force. When bonds do start to break, they are spread throughout the specimen: in, near, and far from, the bottlenecks. In one stage leading up to peak force, bonds collectively break in the lower portion of the specimen, momentarily shifting the bottlenecks to this location. Just before and around peak force, however, the bottlenecks return to their original location and remain there until the macro-crack emerges right along the bottlenecks.

  6. [Predictive study of HBsAg in different stages of neonatal venous blood on failure of blocking HBV mother to infant transmission].

    Science.gov (United States)

    Yi, Wei; Li, Ming-Hui; Hu, Yu-Hong; Liu, Feng; Zhang, Yang-Li; Liu, Xue-Jing; Hao, Hong-Xiao; Song, Shu-Jing; Liu, Ying; Li, Xing-Hong; Sun, Ji-Yun; Liu, Min; Cheng, Jun; Xie, Yao

    2011-10-01

    In this study, we discuss the predictive value of different content of HBsAg in different stages of neotal venous blood on failure of blocking mother to infant transmission of HBV. 150 infants born of chronically HBV infected mothers who were positive of both HBsAg and HBeAg and who also had a HBV DNA virus load above 10(5) copies/ml were enrolled. These infants were given hepatitis B virus immune globin (HBIG) 200 IU immediately after birth and were given hepatitis B vaccine 10 or 20 microg at brith, 1 month and 6 months after birth. HBV serological index of these infants were test at birth, 1 month and 7 months after birth respectively. Different content of HBsAg in different stages of neonatal venus blood were analyzed to predict the failure of blocking mother to infant transmission of HBV. 11 infants failed in blocking of HBV mother to infant transmission. The positive rate of HBsAg at birth, 1 month and 7 months after birth were 41.26%, 10.49% and 7.69% respectively, and were 97.90%, 65.73% and 13.29% of HBeAg. The positive predictive value of HBsAg > or = 0.05 and HBsAg > or = 1 IU/ml at birth were 18.64% and 70% respectively, and were 73.33% and 100% one month after birth. Infants with HBsAg > or = 1 IU/ml at birth should be suspicious of failure on blocking HBV mother-to-infant transmission and it should be more credible if the infant has HBsAg > or = 1 IU/ml one month after birth. How to improve the blocking rate of neonates who were positive of HBsAg at birth and one month after birth should be the focus of our future research.

  7. Usefulness of admission gamma-glutamyltransferase level for predicting new-onset heart failure in patients with acute coronary syndrome with left ventricular systolic dysfunction.

    Science.gov (United States)

    Sarıkaya, Savaş; Aydın, Gülay; Yücel, Hasan; Kaya, Hakkı; Yıldırımlı, Kutay; Başaran, Ahmet; Zorlu, Ali; Sahin, Safak; Akyol, Lütfü; Bulut, Musa

    2014-04-01

    Our aim was to determine whether there is a relationship between admission gamma-glutamyltransferase (GGT) and subsequent heart failure hospitalizations in patients with acute coronary syndrome. We selected 123 patients with newly diagnosed acute coronary syndrome of ejection fraction (EF) 49 IU/L on admission, presence of hypertension and hyperlipidemia, left ventricular ejection fraction (LVEF), right ventricular dysfunction, moderate-to-severe mitral regurgitation, alanine aminotransferase level, and antiplatelet agent usage were found to have prognostic significance in univariate Cox proportional hazards analysis. In multivariate Cox proportional-hazards model, increased GGT >49 IU/L on admission (hazard ratio [HR] 2.663, p=0.047), presence of hypertension (HR 4.107, p=0.007), and LVEF (HR 0.911, p=0.002) were found to be independent factors to predict new-onset heart failure requiring hospitalization. Hospitalization in heart failure was associated with increased admission GGT levels. Increased admission GGT level in acute coronary syndrome with heart failure should be monitored closely and treated aggressively.

  8. Strategies of learning from failure.

    Science.gov (United States)

    Edmondson, Amy C

    2011-04-01

    Many executives believe that all failure is bad (although it usually provides Lessons) and that Learning from it is pretty straightforward. The author, a professor at Harvard Business School, thinks both beliefs are misguided. In organizational life, she says, some failures are inevitable and some are even good. And successful learning from failure is not simple: It requires context-specific strategies. But first leaders must understand how the blame game gets in the way and work to create an organizational culture in which employees feel safe admitting or reporting on failure. Failures fall into three categories: preventable ones in predictable operations, which usually involve deviations from spec; unavoidable ones in complex systems, which may arise from unique combinations of needs, people, and problems; and intelligent ones at the frontier, where "good" failures occur quickly and on a small scale, providing the most valuable information. Strong leadership can build a learning culture-one in which failures large and small are consistently reported and deeply analyzed, and opportunities to experiment are proactively sought. Executives commonly and understandably worry that taking a sympathetic stance toward failure will create an "anything goes" work environment. They should instead recognize that failure is inevitable in today's complex work organizations.

  9. Dynamic Failure Properties of the Porcine Medial Collateral Ligament-Bone Complex for Predicting Injury in Automotive Collisions

    Science.gov (United States)

    Peck, Louis; Billiar, Kristen; Ray, Malcolm

    2010-01-01

    The goal of this study was to model the dynamic failure properties of ligaments and their attachment sites to facilitate the development of more realistic dynamic finite element models of the human lower extremities for use in automotive collision simulations. Porcine medial collateral ligaments were chosen as a test model due to their similarities in size and geometry with human ligaments. Each porcine medial collateral ligament-bone complex (n = 12) was held in a custom test fixture placed in a drop tower to apply an axial impulsive impact load, applying strain rates ranging from 0.005 s-1 to 145 s-1. The data from the impact tests were analyzed using nonlinear regression to construct model equations for predicting the failure load of ligament-bone complexes subjected to specific strain rates as calculated from finite element knee, thigh, and hip impact simulations. The majority of the ligaments tested failed by tibial avulsion (75%) while the remaining ligaments failed via mid-substance tearing. The failure load ranged from 384 N to 1184 N and was found to increase with the applied strain rate and the product of ligament length and cross-sectional area. The findings of this study indicate the force required to rupture the porcine MCL increases with the applied bone-to-bone strain rate in the range expected from high speed frontal automotive collisions. PMID:20461229

  10. Cardiac metaiodobenzylguanidine activity can predict the long-term efficacy of angiotensin-converting enzyme inhibitors and/or beta-adrenoceptor blockers in patients with heart failure

    Energy Technology Data Exchange (ETDEWEB)

    Nakata, Tomoaki; Wakabayashi, Takeru; Kyuma, Michifumi; Takahashi, Toru; Tsuchihashi, Kazufumi; Shimamoto, Kazuaki [Sapporo Medical University School of Medicine, Second Department of Internal Medicine (Cardiology), Sapporo (Japan)

    2005-02-01

    Although the benefits of treatment with angiotensin-converting enzyme (ACE) inhibitors and beta-blockers are well known, no method has as yet been established to predict the efficacy of drug therapy. This study tested whether cardiac{sup 123}I-metaiodobenzylguanidine (MIBG) activity is of prognostic value and can predict the improvement in heart failure patients resulting from treatment with ACE inhibitors and/or beta-blockers. Following quantification of the heart-to-mediastinum ratio (HMR) of MIBG activity, 88 patients with heart failure who were treated with ACE inhibitors and/or beta-blockers (treated group) and 79 patients with heart failure who were treated conventionally without the aforementioned agents, and who served as controls, were followed up for 43 months with a primary endpoint of cardiac death. The treated group had a significantly lower prevalence of cardiac death and a significantly lower mortality at 5 years compared with the control group (15% vs 37% and 21% vs 42%, p<0.05, respectively). Multivariate analysis revealed that significant predictors were HMR, age, nitrate use and ventricular tachycardia for the treated group, and HMR, nitrate use and NYHA class for the control group. The drug treatment significantly reduced mortality from 36% to 12% when HMR was 1.53 or more and from 53% to 37% when HMR was less than 1.53. The reduction in risk of mortality within 5 years in patients without a severe MIBG defect (67%) was twice that in patients with such a defect (32%) (p<0.05). The reduction in mortality risk achieved by using ACE inhibitors and/or beta-blockers is associated with the severity of impairment of cardiac MIBG uptake. Cardiac MIBG activity can consequently be of long-term prognostic value in predicting the effectiveness of such treatment in patients with heart failure. (orig.)

  11. Cardiac metaiodobenzylguanidine activity can predict the long-term efficacy of angiotensin-converting enzyme inhibitors and/or beta-adrenoceptor blockers in patients with heart failure

    International Nuclear Information System (INIS)

    Nakata, Tomoaki; Wakabayashi, Takeru; Kyuma, Michifumi; Takahashi, Toru; Tsuchihashi, Kazufumi; Shimamoto, Kazuaki

    2005-01-01

    Although the benefits of treatment with angiotensin-converting enzyme (ACE) inhibitors and beta-blockers are well known, no method has as yet been established to predict the efficacy of drug therapy. This study tested whether cardiac 123 I-metaiodobenzylguanidine (MIBG) activity is of prognostic value and can predict the improvement in heart failure patients resulting from treatment with ACE inhibitors and/or beta-blockers. Following quantification of the heart-to-mediastinum ratio (HMR) of MIBG activity, 88 patients with heart failure who were treated with ACE inhibitors and/or beta-blockers (treated group) and 79 patients with heart failure who were treated conventionally without the aforementioned agents, and who served as controls, were followed up for 43 months with a primary endpoint of cardiac death. The treated group had a significantly lower prevalence of cardiac death and a significantly lower mortality at 5 years compared with the control group (15% vs 37% and 21% vs 42%, p<0.05, respectively). Multivariate analysis revealed that significant predictors were HMR, age, nitrate use and ventricular tachycardia for the treated group, and HMR, nitrate use and NYHA class for the control group. The drug treatment significantly reduced mortality from 36% to 12% when HMR was 1.53 or more and from 53% to 37% when HMR was less than 1.53. The reduction in risk of mortality within 5 years in patients without a severe MIBG defect (67%) was twice that in patients with such a defect (32%) (p<0.05). The reduction in mortality risk achieved by using ACE inhibitors and/or beta-blockers is associated with the severity of impairment of cardiac MIBG uptake. Cardiac MIBG activity can consequently be of long-term prognostic value in predicting the effectiveness of such treatment in patients with heart failure. (orig.)

  12. Influence of Different Yield Loci on Failure Prediction with Damage Models

    Science.gov (United States)

    Heibel, S.; Nester, W.; Clausmeyer, T.; Tekkaya, A. E.

    2017-09-01

    Advanced high strength steels are widely used in the automotive industry to simultaneously improve crash performance and reduce the car body weight. A drawback of these multiphase steels is their sensitivity to damage effects and thus the reduction of ductility. For that reason the Forming Limit Curve is only partially suitable for this class of steels. An improvement in failure prediction can be obtained by using damage mechanics. The objective of this paper is to comparatively review the phenomenological damage model GISSMO and the Enhanced Lemaitre Damage Model. GISSMO is combined with three different yield loci, namely von Mises, Hill48 and Barlat2000 to investigate the influence of the choice of the plasticity description on damage modelling. The Enhanced Lemaitre Model is used with Hill48. An inverse parameter identification strategy for a DP1000 based on stress-strain curves and optical strain measurements of shear, uniaxial, notch and (equi-)biaxial tension tests is applied to calibrate the models. A strong dependency of fracture strains on the choice of yield locus can be observed. The identified models are validated on a cross-die cup showing ductile fracture with slight necking.

  13. Micromechanical Failure Analyses for Finite Element Polymer Modeling

    Energy Technology Data Exchange (ETDEWEB)

    CHAMBERS,ROBERT S.; REEDY JR.,EARL DAVID; LO,CHI S.; ADOLF,DOUGLAS B.; GUESS,TOMMY R.

    2000-11-01

    Polymer stresses around sharp corners and in constrained geometries of encapsulated components can generate cracks leading to system failures. Often, analysts use maximum stresses as a qualitative indicator for evaluating the strength of encapsulated component designs. Although this approach has been useful for making relative comparisons screening prospective design changes, it has not been tied quantitatively to failure. Accurate failure models are needed for analyses to predict whether encapsulated components meet life cycle requirements. With Sandia's recently developed nonlinear viscoelastic polymer models, it has been possible to examine more accurately the local stress-strain distributions in zones of likely failure initiation looking for physically based failure mechanisms and continuum metrics that correlate with the cohesive failure event. This study has identified significant differences between rubbery and glassy failure mechanisms that suggest reasonable alternatives for cohesive failure criteria and metrics. Rubbery failure seems best characterized by the mechanisms of finite extensibility and appears to correlate with maximum strain predictions. Glassy failure, however, seems driven by cavitation and correlates with the maximum hydrostatic tension. Using these metrics, two three-point bending geometries were tested and analyzed under variable loading rates, different temperatures and comparable mesh resolution (i.e., accuracy) to make quantitative failure predictions. The resulting predictions and observations agreed well suggesting the need for additional research. In a separate, additional study, the asymptotically singular stress state found at the tip of a rigid, square inclusion embedded within a thin, linear elastic disk was determined for uniform cooling. The singular stress field is characterized by a single stress intensity factor K{sub a} and the applicable K{sub a} calibration relationship has been determined for both fully bonded and

  14. Study on precursory characteristics of granite failure based on infrasonic energy

    Directory of Open Access Journals (Sweden)

    Jian-ping Wei

    Full Text Available To study signal characteristics of precursory infrasound of granite failure, coal-rock stress loading device and infrasound acquisition device were adopted to perform infrasound test in uniaxial loading process for granite samples. Wavelet filtering, infrasonic energy methods were used to process and analyze the test results. The results show that the infrasonic waves caused by the failure of rock samples are mainly in the middle and low frequency. Moreover, in the loading process, the ratio of relative energy of infrasound in different frequency sections and the total relative energy of the whole low frequency section both exhibit significant regularity of stage change, which is in consistent with the compaction stage, elastic stage, plastic stage of rock deformation. Additionally, the precursory characteristics of infrasound before rock failures are prominent and easy to be recognized. Meanwhile, infrasonic wave has the advantage of low attenuation in propagation process, which grants the superiority of infrasound prediction technology. A new method of rock failure prediction based on infrasound is formed, which provides an important reference for rock damage prediction in coal mining process. Keywords: Infrasonic energy, Wavelet filtering, Precursory characteristics, Failure prediction

  15. Predicting Failure in Early Acute Prosthetic Joint Infection Treated With Debridement, Antibiotics, and Implant Retention: External Validation of the KLIC Score.

    Science.gov (United States)

    Löwik, Claudia A M; Jutte, Paul C; Tornero, Eduard; Ploegmakers, Joris J W; Knobben, Bas A S; de Vries, Astrid J; Zijlstra, Wierd P; Dijkstra, Baukje; Soriano, Alex; Wouthuyzen-Bakker, Marjan

    2018-03-27

    Debridement, antibiotics, and implant retention (DAIR) is a widely used treatment modality for early acute prosthetic joint infection (PJI). A preoperative risk score was previously designed for predicting DAIR failure, consisting of chronic renal failure (K), liver cirrhosis (L), index surgery (I), cemented prosthesis (C), and C-reactive protein >115 mg/L (KLIC). The aim of this study was to validate the KLIC score in an external cohort. We retrospectively evaluated patients with early acute PJI treated with DAIR between 2006 and 2016 in 3 Dutch hospitals. Early acute PJI was defined as infection-related death within 60 days after debridement. A total of 386 patients were included. Failure occurred in 148 patients (38.3%). Patients with KLIC scores of ≤2, 2.5-3.5, 4-5, 5.5-6.5, and ≥7 had failure rates of 27.9%, 37.1%, 49.3%, 54.5%, and 85.7%, respectively (P < .001). The receiver-operating characteristic curve showed an area under the curve of 0.64 (95% confidence interval 0.59-0.69). A KLIC score higher than 6 points showed a specificity of 97.9%. The KLIC score is a relatively good preoperative risk score for DAIR failure in patients with early acute PJI and appears to be most useful in clinical practice for patients with low or high KLIC scores. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Can We Rely on Predicted Basal Metabolic Rate in Patients With Intestinal Failure on Home Parenteral Nutrition?

    Science.gov (United States)

    Skallerup, Anders; Nygaard, Louis; Olesen, Søren Schou; Vinter-Jensen, Lars; Køhler, Marianne; Rasmussen, Henrik Højgaard

    2017-09-01

    Intestinal failure (IF) is a serious and common complication of short bowel syndrome with patients depending on parenteral nutrition (PN) support. Effective nutrition management requires an accurate estimation of the patient's basal metabolic rate (BMR) to avoid underfeeding or overfeeding. However, indirect calorimetry, considered the gold standard for BMR assessment, is a time- and resource-consuming procedure. Consequently, several equations for prediction of BMR have been developed in different settings, but their accuracy in patients with IF are yet to be investigated. We evaluated the accuracy of predicted BMR in clinically stable patients with IF dependent on home parenteral nutrition (HPN). In total, 103 patients with IF were included. We used indirect calorimetry for assessment of BMR and calculated predicted BMR using different equations based on anthropometric and/or bioelectrical impedance parameters. The accuracy of predicted BMR was evaluated using Bland-Altman analysis with measured BMR as the gold standard. The average measured BMR was 1272 ± 245 kcal/d. The most accurate estimations of BMR were obtained using the Harris-Benedict equation (mean bias, 14 kcal/d [ P = .28]; limits of agreement [LoA], -238 to 266 kcal/d) and the Johnstone equation (mean bias, -16 kcal/d [ P = .24]; LoA, -285 to 253 kcal/d). For both equations, 67% of patients had a predicted BMR from 90%-110% All other equations demonstrated a statistically and clinically significant difference between measured and predicted BMR. The Harris-Benedict and Johnstone equations reliably predict BMR in two-thirds of clinically stable patients with IF on HPN.

  17. Clinical value of iodine-123 beta-methyliodophenyl pentadecanoic acid (BMIPP) myocardial single photon emission computed tomography for predicting cardiac death among patients with chronic heart failure

    International Nuclear Information System (INIS)

    Sasaki, Ryu; Usui, Takashi; Mitani, Isao

    2003-01-01

    In the present study, the effectiveness of 123 I-β-methyliodophenyl pentadecanoic acid (BMIPP) single photon emission computed tomography (SPECT) for predicting cardiac death of patients with chronic heart failure was evaluated. Abnormalities of fatty acid metabolism are found in patients with chronic heart failure and BMIPP was developed as a tracer for scintigraphic assessment of myocardial fatty acid utilization. The study group comprised 74 patients with chronic heart failure with a left ventricular ejection fraction (LVEF) 201 Tl SPECT and BMIPP SPECT. The uptake of tracer was scored semiquantitatively from 0 (normal) to 4 (defect) in 20 segments and a total defect score (TDS) for all 20 segments was calculated. On planar images the mediastinum to heart count ratio (H/M) was calculated for the BMIPP and Tl studies, and the H/M BMIPP :H/M Tl (H/M BMIPP divided by H/M Tl ) was also calculated. The mean follow-up period was 660 days and there were 17 cases of cardiac death. Multivariate analysis identified H/M BMIPP :H/M Tl (p BMIPP :H/M Tl was situated to the left relative to LVEF. Analysis of the myocardial metabolism by BMIPP SPECT can predict the high-risk patients with chronic heart failure. (author)

  18. Dependent failure analysis of NPP data bases

    International Nuclear Information System (INIS)

    Cooper, S.E.; Lofgren, E.V.; Samanta, P.K.; Wong Seemeng

    1993-01-01

    A technical approach for analyzing plant-specific data bases for vulnerabilities to dependent failures has been developed and applied. Since the focus of this work is to aid in the formulation of defenses to dependent failures, rather than to quantify dependent failure probabilities, the approach of this analysis is critically different. For instance, the determination of component failure dependencies has been based upon identical failure mechanisms related to component piecepart failures, rather than failure modes. Also, component failures involving all types of component function loss (e.g., catastrophic, degraded, incipient) are equally important to the predictive purposes of dependent failure defense development. Consequently, dependent component failures are identified with a different dependent failure definition which uses a component failure mechanism categorization scheme in this study. In this context, clusters of component failures which satisfy the revised dependent failure definition are termed common failure mechanism (CFM) events. Motor-operated valves (MOVs) in two nuclear power plant data bases have been analyzed with this approach. The analysis results include seven different failure mechanism categories; identified potential CFM events; an assessment of the risk-significance of the potential CFM events using existing probabilistic risk assessments (PRAs); and postulated defenses to the identified potential CFM events. (orig.)

  19. Biomarkers in acute heart failure.

    Science.gov (United States)

    Mallick, Aditi; Januzzi, James L

    2015-06-01

    The care of patients with acutely decompensated heart failure is being reshaped by the availability and understanding of several novel and emerging heart failure biomarkers. The gold standard biomarkers in heart failure are B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide, which play an important role in the diagnosis, prognosis, and management of acute decompensated heart failure. Novel biomarkers that are increasingly involved in the processes of myocardial injury, neurohormonal activation, and ventricular remodeling are showing promise in improving diagnosis and prognosis among patients with acute decompensated heart failure. These include midregional proatrial natriuretic peptide, soluble ST2, galectin-3, highly-sensitive troponin, and midregional proadrenomedullin. There has also been an emergence of biomarkers for evaluation of acute decompensated heart failure that assist in the differential diagnosis of dyspnea, such as procalcitonin (for identification of acute pneumonia), as well as markers that predict complications of acute decompensated heart failure, such as renal injury markers. In this article, we will review the pathophysiology and usefulness of established and emerging biomarkers for the clinical diagnosis, prognosis, and management of acute decompensated heart failure. Copyright © 2015 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  20. Realization in 2007 of the complex project on creation of the thematic atlas modern and prediction aspects of consequences from Chernobyl NPP failure

    International Nuclear Information System (INIS)

    Poplyko, I.Ya.; Nikolaenko, E.V.

    2008-01-01

    The thematic atlas modern and prediction aspects of consequences from Chernobyl NPP failure in the suffered territories of Russia and Belarus will contain materials about radioactive pollution of territories, the grounds of wood fund, the agricultural grounds, and as help section, including analytical and help materials. (authors)

  1. Predictive factors for renal failure and a control and treatment algorithm

    Directory of Open Access Journals (Sweden)

    Denise de Paula Cerqueira

    2014-04-01

    Full Text Available OBJECTIVES: to evaluate the renal function of patients in an intensive care unit, to identify the predisposing factors for the development of renal failure, and to develop an algorithm to help in the control of the disease.METHOD: exploratory, descriptive, prospective study with a quantitative approach.RESULTS: a total of 30 patients (75.0% were diagnosed with kidney failure and the main factors associated with this disease were: advanced age, systemic arterial hypertension, diabetes mellitus, lung diseases, and antibiotic use. Of these, 23 patients (76.6% showed a reduction in creatinine clearance in the first 24 hours of hospitalization.CONCLUSION: a decline in renal function was observed in a significant number of subjects, therefore, an algorithm was developed with the aim of helping in the control of renal failure in a practical and functional way.

  2. A personalized BEST: characterization of latent clinical classes of nonischemic heart failure that predict outcomes and response to bucindolol.

    Directory of Open Access Journals (Sweden)

    David P Kao

    Full Text Available Heart failure patients with reduced ejection fraction (HFREF are heterogenous, and our ability to identify patients likely to respond to therapy is limited. We present a method of identifying disease subtypes using high-dimensional clinical phenotyping and latent class analysis that may be useful in personalizing prognosis and treatment in HFREF.A total of 1121 patients with nonischemic HFREF from the β-blocker Evaluation of Survival Trial were categorized according to 27 clinical features. Latent class analysis was used to generate two latent class models, LCM A and B, to identify HFREF subtypes. LCM A consisted of features associated with HF pathogenesis, whereas LCM B consisted of markers of HF progression and severity. The Seattle Heart Failure Model (SHFM Score was also calculated for all patients. Mortality, improvement in left ventricular ejection fraction (LVEF defined as an increase in LVEF ≥5% and a final LVEF of 35% after 12 months, and effect of bucindolol on both outcomes were compared across HFREF subtypes. Performance of models that included a combination of LCM subtypes and SHFM scores towards predicting mortality and LVEF response was estimated and subsequently validated using leave-one-out cross-validation and data from the Multicenter Oral Carvedilol Heart Failure Assessment Trial.A total of 6 subtypes were identified using LCM A and 5 subtypes using LCM B. Several subtypes resembled familiar clinical phenotypes. Prognosis, improvement in LVEF, and the effect of bucindolol treatment differed significantly between subtypes. Prediction improved with addition of both latent class models to SHFM for both 1-year mortality and LVEF response outcomes.The combination of high-dimensional phenotyping and latent class analysis identifies subtypes of HFREF with implications for prognosis and response to specific therapies that may provide insight into mechanisms of disease. These subtypes may facilitate development of personalized

  3. Graft intolerance syndrome requiring graft nephrectomy after late kidney graft failure: can it be predicted? A retrospective cohort study.

    Science.gov (United States)

    Bunthof, Kim L W; Verhoeks, Carmen M; van den Brand, Jan A J G; Hilbrands, Luuk B

    2018-02-01

    Graft nephrectomy is recommended in case of early graft failure. When the graft fails more than 3-6 months after transplantation, it is current practice to follow a wait-and-see policy. A common indication for graft removal is the graft intolerance syndrome. We aimed to create a risk prediction model for the occurrence of graft intolerance resulting in graft nephrectomy. We collected data of kidney transplantations performed in our center between 1980 and 2010 that failed at least 6 months after transplantation. We evaluated the association between baseline characteristics and the occurrence of graft nephrectomy because of graft intolerance using a competing risk regression model. Prognostic factors were included in a multivariate prediction model. In- and exclusion criteria were met in 288 cases. In 48 patients, the graft was removed because of graft intolerance. Donor age, the number of rejections, and shorter graft survival were predictive factors for graft nephrectomy because of the graft intolerance syndrome. These factors were included in a prediction rule. Using donor age, graft survival, and the number of rejections, clinicians can predict the need for graft nephrectomy with a reasonable accuracy. © 2017 Steunstichting ESOT.

  4. Failure time series prediction in industrial maintenance using neural networks; Previsao de series temporais de falhas em manutencao industrial usando redes neurais

    Energy Technology Data Exchange (ETDEWEB)

    Torres Junior, Rubiao G.; Machado, Maria Augusta S. [Instituto Brasileiro de Mercado de Capitais (IBMEC), Rio de Janeiro, RJ (Brazil); Souza, Reinaldo C. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil)

    2005-07-01

    The objective of this work is the application of two failure prediction models in industrial maintenance with the use of Artificial Neural Networks (ANN). A characteristic of the modern industrial environment is a strong competition which leads companies to search for costs minimization methods. Thus, dada gathering and maintenance dada treatment becomes extremely important in this scenario for it aims the equipment and plant systems real repair necessity. Therefore, the objective becomes the widening of the system's full activity in a continuous manner, in the required period, without problems in their integrating parts. A daily time series is modeled based on maintenance interventions pauses dada from a five years period derived form many productive systems in the finalization areas of PETROFLEX Ind. and Com. S.A. Thus, the purpose is to introduce models based on neural networks and verify its system's pauses prediction capacity, so as to intervene with adequate timing before the system fails, extend the operational period and consequently increase its availability. The results obtained in this work demonstrate the employment of Neural Networks in the prediction of pauses in PETROFLEX industrial area maintenance. The ANN's prediction capacity in a group of dada with strong non-linear component where other statistical techniques have shown little efficient has also been confirmed. Discover neural models to predict failure systems time series has enable a breakthrough in the research field, especially due to the market demand. It's no doubt a technique that will evolve in the industrial maintenance area financing important managing decision. Prediction techniques, such as the ones illustrated in this study, work side by side maintenance planning and if carefully implemented and followed up can in the medium run supply a substantial increase in the available operational hours. (author)

  5. Ratio of Systolic Blood Pressure to Right Atrial Pressure, a Novel Marker to Predict Morbidity and Mortality in Acute Systolic Heart Failure.

    Science.gov (United States)

    Omar, Hesham R; Charnigo, Richard; Guglin, Maya

    2017-04-01

    Congestion is the main contributor to heart failure (HF) morbidity and mortality. We assessed the combined role of congestion and decreased forward flow in predicting morbidity and mortality in acute systolic HF. The Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial data set was used to determine if the ratio of simultaneously measured systolic blood pressure (SBP)/right atrial pressure (RAP) on admission predicted HF rehospitalization and 6-month mortality. One hundred ninety-five patients (mean age 56.5 years, 75% men) who received pulmonary artery catheterization were studied. The RAP, SBP, and SBP/RAP had an area under the curve (AUC) of 0.593 (p = 0.0205), 0.585 (p = 0.0359), and 0.621 (p = 0.0026), respectively, in predicting HF rehospitalization. The SBP/RAP was a superior marker of HF rehospitalization compared with RAP alone (difference in AUC 0.0289, p = 0.0385). The optimal criterion of SBP/RAP AUC 0.622, p = 0.0108, and a cut-off value of SBP/RAP <8 had a sensitivity of 61.9% and specificity 64.1% in predicting mortality. Multivariate analysis showed that an SBP/RAP <11 independently predicted rehospitalization for HF (estimated odds ratio 3.318, 95% confidence interval 1.692 to 6.506, p = 0.0005) and an SBP/RAP <8 independently predicted mortality (estimated hazard ratio 2.025, 95% confidence interval 1.069 to 3.833, p = 0.030). In conclusion, SBP/RAP ratio is a marker that identifies a spectrum of complications after hospitalization of patients with decompensated systolic HF, starting with increased incidence of HF rehospitalization at SBP/RAP <11 to increased mortality with SBP/RAP <8. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Computational models can predict response to HIV therapy without a genotype and may reduce treatment failure in different resource-limited settings.

    Science.gov (United States)

    Revell, A D; Wang, D; Wood, R; Morrow, C; Tempelman, H; Hamers, R L; Alvarez-Uria, G; Streinu-Cercel, A; Ene, L; Wensing, A M J; DeWolf, F; Nelson, M; Montaner, J S; Lane, H C; Larder, B A

    2013-06-01

    Genotypic HIV drug-resistance testing is typically 60%-65% predictive of response to combination antiretroviral therapy (ART) and is valuable for guiding treatment changes. Genotyping is unavailable in many resource-limited settings (RLSs). We aimed to develop models that can predict response to ART without a genotype and evaluated their potential as a treatment support tool in RLSs. Random forest models were trained to predict the probability of response to ART (≤400 copies HIV RNA/mL) using the following data from 14 891 treatment change episodes (TCEs) after virological failure, from well-resourced countries: viral load and CD4 count prior to treatment change, treatment history, drugs in the new regimen, time to follow-up and follow-up viral load. Models were assessed by cross-validation during development, with an independent set of 800 cases from well-resourced countries, plus 231 cases from Southern Africa, 206 from India and 375 from Romania. The area under the receiver operating characteristic curve (AUC) was the main outcome measure. The models achieved an AUC of 0.74-0.81 during cross-validation and 0.76-0.77 with the 800 test TCEs. They achieved AUCs of 0.58-0.65 (Southern Africa), 0.63 (India) and 0.70 (Romania). Models were more accurate for data from the well-resourced countries than for cases from Southern Africa and India (P < 0.001), but not Romania. The models identified alternative, available drug regimens predicted to result in virological response for 94% of virological failures in Southern Africa, 99% of those in India and 93% of those in Romania. We developed computational models that predict virological response to ART without a genotype with comparable accuracy to genotyping with rule-based interpretation. These models have the potential to help optimize antiretroviral therapy for patients in RLSs where genotyping is not generally available.

  7. Mitochondrial markers predict recurrence, metastasis and tamoxifen-resistance in breast cancer patients: Early detection of treatment failure with companion diagnostics.

    Science.gov (United States)

    Sotgia, Federica; Fiorillo, Marco; Lisanti, Michael P

    2017-09-15

    Here, we used a data-mining and informatics approach to discover new biomarkers of resistance to hormonal therapy in breast cancer. More specifically, we investigated whether nuclear-encoded genes associated with mitochondrial biogenesis can be used to predict tumor recurrence, distant metastasis and treatment failure in high-risk breast cancer patients. Overall, this strategy allowed us to directly provide in silico validation of the prognostic value of these mitochondrial components in large and clinically relevant patient populations, with >15 years of follow-up data. For this purpose, we employed a group of 145 ER(+) luminal A breast cancer patients, with lymph-node (LN) metastasis at diagnosis, that were treated with tamoxifen, but not any chemotherapy agents. Using this approach, we identified >60 new individual mitochondrial biomarkers that predicted treatment failure and tumor recurrence, with hazard-ratios (HR) of up to 4.17 ( p =2.2e-07). These include mitochondrial chaperones (HSPD1, HSPA9), membrane proteins (VDAC2, TOMM70A) and anti-oxidants (SOD2), as well as 18 different mitochondrial ribosomal proteins (MRPs) and >20 distinct components of the OXPHOS complexes. In addition, we combined 4 mitochondrial proteins (HSPD1, UQCRB, MRPL15, COX17), to generate a compact mitochondrial gene signature, associated with a HR of 5.34 ( p =1e-09). This signature also successfully predicted distant metastasis and was effective in larger groups of ER(+) ( N =2,447), basal ( N =540) and HER2(+) ( N =193) breast cancers. It was also effective in all breast cancers ( N =3,180), if considered together as a single group. Based on this analysis, we conclude that mitochondrial biogenesis should be considered as a new therapeutic target for overcoming tumor recurrence, distant metastasis and treatment failure in patients with breast cancer. In summary, we identified individual mitochondrial biomarkers and 2 compact mitochondrial gene signatures that can be used to predict

  8. Failure and reliability prediction by support vector machines regression of time series data

    International Nuclear Information System (INIS)

    Chagas Moura, Marcio das; Zio, Enrico; Lins, Isis Didier; Droguett, Enrique

    2011-01-01

    Support Vector Machines (SVMs) are kernel-based learning methods, which have been successfully adopted for regression problems. However, their use in reliability applications has not been widely explored. In this paper, a comparative analysis is presented in order to evaluate the SVM effectiveness in forecasting time-to-failure and reliability of engineered components based on time series data. The performance on literature case studies of SVM regression is measured against other advanced learning methods such as the Radial Basis Function, the traditional MultiLayer Perceptron model, Box-Jenkins autoregressive-integrated-moving average and the Infinite Impulse Response Locally Recurrent Neural Networks. The comparison shows that in the analyzed cases, SVM outperforms or is comparable to other techniques. - Highlights: → Realistic modeling of reliability demands complex mathematical formulations. → SVM is proper when the relation input/output is unknown or very costly to be obtained. → Results indicate the potential of SVM for reliability time series prediction. → Reliability estimates support the establishment of adequate maintenance strategies.

  9. Development of container failure models

    International Nuclear Information System (INIS)

    Garisto, N.C.

    1990-01-01

    In order to produce a complete performance assessment for a Canadian waste vault some prediction of container failure times is required. Data are limited; however, the effects of various possible failure scenarios on the rest of the vault model can be tested. For titanium and copper, the two materials considered in the Canadian program, data are available on the frequency of failures due to manufacturing defects; there is also an estimate on the expected size of such defects. It can be shown that the consequences of such small defects in terms of the dose to humans are acceptable. It is not clear, from a modelling point of view, whether titanium or copper are preferable

  10. Knowledge representation methods for early failure detection

    International Nuclear Information System (INIS)

    Scherer, K.P.; Stiller, P.

    1990-01-01

    To supervise technical processes like nuclear power plants, it is very important to detect failure modes in an early stage. In the nuclear research center at Karlsruhe an expert system is developed, embedded in a computer network of autonomous computers, which are used for intelligent prepocessing. Events, process data and actual parameter values are stored in slots of special frames in the knowledge base of the expert system. Both rule based and fact based knowledge representations are employed to generate cause consequence chains of failure states. By on-line surveillance of the reactor process, the slots of the frames are dynamically actualized. Immediately after the evaluation, the inference engine starts in the special domain experts (triggered by metarules from a manager) and detects the correspondend failures or anomaly state. Matching the members of the chain and regarding a catalogue of instructions and messages, what is to do by the operator, future failure states can be estimated and propagation can be prohibited. That means qualitative failure prediction based on cause consequence in the static part of the knowledge base. Also, a time series of physical data can be used to predict on analytical way future process state and to continue such a theoretical propagation with matching the cause consuquence chain

  11. LSSVM-Based Rock Failure Criterion and Its Application in Numerical Simulation

    Directory of Open Access Journals (Sweden)

    Changxing Zhu

    2015-01-01

    Full Text Available A rock failure criterion is very important for the prediction of the failure of rocks or rock masses in rock mechanics and engineering. Least squares support vector machines (LSSVM are a powerful tool for addressing complex nonlinear problems. This paper describes a LSSVM-based rock failure criterion for analyzing the deformation of a circular tunnel under different in situ stresses without assuming a function form. First, LSSVM was used to represent the nonlinear relationship between the mechanical properties of rock and the failure behavior of the rock in order to construct a rock failure criterion based on experimental data. Then, this was used in a hypothetical numerical analysis of a circular tunnel to analyze the mechanical behavior of the rock mass surrounding the tunnel. The Mohr-Coulomb and Hoek-Brown failure criteria were also used to analyze the same case, and the results were compared; these clearly indicate that LSSVM can be used to establish a rock failure criterion and to predict the failure of a rock mass during excavation of a circular tunnel.

  12. Temporal-varying failures of nodes in networks

    Science.gov (United States)

    Knight, Georgie; Cristadoro, Giampaolo; Altmann, Eduardo G.

    2015-08-01

    We consider networks in which random walkers are removed because of the failure of specific nodes. We interpret the rate of loss as a measure of the importance of nodes, a notion we denote as failure centrality. We show that the degree of the node is not sufficient to determine this measure and that, in a first approximation, the shortest loops through the node have to be taken into account. We propose approximations of the failure centrality which are valid for temporal-varying failures, and we dwell on the possibility of externally changing the relative importance of nodes in a given network by exploiting the interference between the loops of a node and the cycles of the temporal pattern of failures. In the limit of long failure cycles we show analytically that the escape in a node is larger than the one estimated from a stochastic failure with the same failure probability. We test our general formalism in two real-world networks (air-transportation and e-mail users) and show how communities lead to deviations from predictions for failures in hubs.

  13. On rate-state and Coulomb failure models

    Science.gov (United States)

    Gomberg, J.; Beeler, N.; Blanpied, M.

    2000-01-01

    We examine the predictions of Coulomb failure stress and rate-state frictional models. We study the change in failure time (clock advance) Δt due to stress step perturbations (i.e., coseismic static stress increases) added to "background" stressing at a constant rate (i.e., tectonic loading) at time t0. The predictability of Δt implies a predictable change in seismicity rate r(t)/r0, testable using earthquake catalogs, where r0 is the constant rate resulting from tectonic stressing. Models of r(t)/r0, consistent with general properties of aftershock sequences, must predict an Omori law seismicity decay rate, a sequence duration that is less than a few percent of the mainshock cycle time and a return directly to the background rate. A Coulomb model requires that a fault remains locked during loading, that failure occur instantaneously, and that Δt is independent of t0. These characteristics imply an instantaneous infinite seismicity rate increase of zero duration. Numerical calculations of r(t)/r0 for different state evolution laws show that aftershocks occur on faults extremely close to failure at the mainshock origin time, that these faults must be "Coulomb-like," and that the slip evolution law can be precluded. Real aftershock population characteristics also may constrain rate-state constitutive parameters; a may be lower than laboratory values, the stiffness may be high, and/or normal stress may be lower than lithostatic. We also compare Coulomb and rate-state models theoretically. Rate-state model fault behavior becomes more Coulomb-like as constitutive parameter a decreases relative to parameter b. This is because the slip initially decelerates, representing an initial healing of fault contacts. The deceleration is more pronounced for smaller a, more closely simulating a locked fault. Even when the rate-state Δt has Coulomb characteristics, its magnitude may differ by some constant dependent on b. In this case, a rate-state model behaves like a modified

  14. Lack of pro-inflammatory cytokine mobilization predicts poor prognosis in patients with acute heart failure.

    Science.gov (United States)

    Vistnes, M; Høiseth, A D; Røsjø, H; Nygård, S; Pettersen, E; Søyseth, V; Hurlen, P; Christensen, G; Omland, T

    2013-03-01

    The aim of this study was to gain insight in the inflammatory response in acute heart failure (AHF) by assessing (1) plasma cytokine profiles and (2) prognostic value of circulating cytokines in AHF patients. Plasma levels of 26 cytokines were quantified by multiplex protein arrays in 36 patients with congestive AHF, characterized by echocardiographic, radiologic, and clinical examinations on admission, during hospitalization and at discharge. Recurrent AHF leading to death or readmission constituted the combined end point, and all patients were followed for 120 days after discharge. Levels of 15 of the measured cytokines were higher in AHF than in healthy subjects (n=22) on admission. Low levels of MCP-1, IL-1β and a low IL-1β/IL-1ra ratio predicted fatal and non-fatal AHF within 120 days. Patients with low circulating levels of IL-1β had lower left ventricular ejection fraction and higher levels of N-terminal pro-B-type natriuretic peptide, while patients with low levels of MCP-1 had higher E/E' and inferior caval vein diameter, than patients with high levels. Immune activation, reflected in increased cytokine levels, is present in AHF patients. Interestingly, failure to increase secretion of IL-1β and MCP-1 during AHF is associated with poor outcome. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Bubble nasal CPAP, early surfactant treatment, and rapid extubation are associated with decreased incidence of bronchopulmonary dysplasia in very-low-birth-weight newborns: efficacy and safety considerations.

    Science.gov (United States)

    Friedman, Charles A; Menchaca, Robert C; Baker, Mary C; Rivas, Clarissa K; Laberge, Raymond N; Rios, Enrique H; Haider, Syed H; Romero, Edgar J; Eason, Elizabeth B; Fraley, J Kennard; Woldesenbet, Mesfin

    2013-07-01

    Current literature has been inconsistent in demonstrating that minimizing the duration of mechanical ventilation in very-low-birth-weight (VLBW) newborns reduces lung damage. To determine if introduction of bubble nasal CPAP (bnCPAP), early surfactant treatment, and rapid extubation (combined bnCPAP strategy) in our community-based neonatal ICU reduced bronchopulmonary dysplasia (BPD). This was a 7-year retrospective,single-institution review of respiratory outcomes in 633 VLBW babies before and after introduction of the combined bnCPAP strategy. Coincident changes in newborn care were taken into account with a logistic regression model. The average percentage of VLBW newborns with BPD decreased to 25.8% from 35.4% (P = .02), reaching a minimum in the last post-bnCPAP year of22.1% (P = .02). When other coincident changes in newborn care during the study years were taken into account, VLBW babies in the post-bnCPAP years had a 43% lower chance of developing BPD(P = .003, odds ratio 0.43, 95% CI 0.25– 0.75). Decreases occurred in mechanical ventilation and the percentage of infants discharged on diuretics and on supplemental oxygen. Among the subset of extremely-low-birth-weight newborns, improved respiratory outcomes in the post-bnCPAP years,as compared to outcomes in the pre-bnCPAP years, included an increase in the percentage alive and off mechanical ventilation at 1 week postnatal age (P < .001), a more rapid extubation rate(P < .03), a decrease in the median days on mechanical ventilation (P = .002), and a decrease in the percentage with BPD plus died (P = .01). Post-bnCPAP extremely-low-birth-weight babies had a statistically significant decrease in retinopathy of prematurity, an increase in low-grade intraventricular hemorrhage, and a decrease in ductal ligations. A combined BnCPAP strategy may contribute to a reduction of BPD, after adjusting for concurrent treatments.

  16. Failure envelope approach for consolidated undrained capacity of shallow foundations

    OpenAIRE

    Vulpe, Cristina; Gourvenec, Susan; Leman, Billy; Fung, Kah Ngii

    2016-01-01

    A generalized framework is applied to predict consolidated undrained VHM failure envelopes for surface circular and strip foundations. The failure envelopes for consolidated undrained conditions are shown to be scaled from those for unconsolidated undrained conditions by the uniaxial consolidated undrained capacities, which are predicted through a theoretical framework based on fundamental critical state soil mechanics. The framework is applied to results from small-strain finite-element anal...

  17. Glyphosate ingestion causing multiple organ failure: a near-fatal case report.

    Science.gov (United States)

    Picetti, Edoardo; Generali, Michela; Mensi, Francesca; Neri, Giampaolo; Damia, Roberta; Lippi, Giuseppe; Cervellin, Gianfranco

    2018-01-16

    A 55 years old man self-presented to our Emergency Department (ED) reporting an attempted suicide by cutting the left forearm veins and ingesting approximately 200 mL of an herbicide (Myrtos®, containing 36% of glyphosate as isopropylamine salt). Laboratory tests showed metabolic acidosis. Hydration with normal saline and alkalinization with sodium bicarbonate was started according to suggestion of the poison control center, since an antidote was unavailable. Cardiorespiratory condition gradually worsened, so that non-invasive positive pressure ventilation (NIPPV) was applied and infusion of fluids was established. Nevertheless, the patient deteriorated and he needed to be transferred to the Intensive Care Unit (ICU), where he underwent orotracheal intubation and invasive mechanical ventilation. Noradrenaline and adrenaline were infused and fluid resuscitation with crystalloids was incremented. An esophagogastroduodenoscopy (EGD) showed diffuse mucosal erosions of upper digestive tract. No signs of visceral perforation were found during ICU stay. In the following days, the clinical conditions improved and a new EGD showed marked improvement of erosive lesions. After 12 days of ICU stay, the patient was extubated and then transferred to the Psychiatric Unit, in good clinical conditions. Gliphosate ingestion is associated with rapid development of multiple organ failure (MOF). Since an effective antidote is unavailable, major attention should be placed to aggressive life-support care and careful monitoring of complications.

  18. Naturally Acquired Learned Helplessness: The Relationship of School Failure to Achievement Behavior, Attributions, and Self-Concept.

    Science.gov (United States)

    Johnson, Dona S.

    1981-01-01

    Personality and behavioral consequences of learned helplessness were monitored in children experiencing failure in school. The predictive quality of learned helplessness theory was compared with that of value expectancy theories. Low self-concept was predicted significantly by school failure, internal attributions for failure, and external…

  19. Perioperative acute renal failure.

    LENUS (Irish Health Repository)

    Mahon, Padraig

    2012-02-03

    PURPOSE OF REVIEW: Recent biochemical evidence increasingly implicates inflammatory mechanisms as precipitants of acute renal failure. In this review, we detail some of these pathways together with potential new therapeutic targets. RECENT FINDINGS: Neutrophil gelatinase-associated lipocalin appears to be a sensitive, specific and reliable biomarker of renal injury, which may be predictive of renal outcome in the perioperative setting. For estimation of glomerular filtration rate, cystatin C is superior to creatinine. No drug is definitively effective at preventing postoperative renal failure. Clinical trials of fenoldopam and atrial natriuretic peptide are, at best, equivocal. As with pharmacological preconditioning of the heart, volatile anaesthetic agents appear to offer a protective effect to the subsequently ischaemic kidney. SUMMARY: Although a greatly improved understanding of the pathophysiology of acute renal failure has offered even more therapeutic targets, the maintenance of intravascular euvolaemia and perfusion pressure is most effective at preventing new postoperative acute renal failure. In the future, strategies targeting renal regeneration after injury will use bone marrow-derived stem cells and growth factors such as insulin-like growth factor-1.

  20. A quantitative method for Failure Mode and Effects Analysis

    NARCIS (Netherlands)

    Braaksma, Anne Johannes Jan; Meesters, A.J.; Klingenberg, W.; Hicks, C.

    2012-01-01

    Failure Mode and Effects Analysis (FMEA) is commonly used for designing maintenance routines by analysing potential failures, predicting their effect and facilitating preventive action. It is used to make decisions on operational and capital expenditure. The literature has reported that despite its

  1. A micromechanical four-phase model to predict the compressive failure surface of cement concrete

    Directory of Open Access Journals (Sweden)

    A. Caporale,

    2014-07-01

    Full Text Available In this work, a micromechanical model is used in order to predict the failure surface of cement concrete subject to multi-axial compression. In the adopted model, the concrete material is schematised as a composite with the following constituents: coarse aggregate (gravel, fine aggregate (sand and cement paste. The cement paste contains some voids which grow during the loading process. In fact, the non-linear behavior of the concrete is attributed to the creation of cracks in the cement paste; the effect of the cracks is taken into account by introducing equivalent voids (inclusions with zero stiffness in the cement paste. The three types of inclusions (namely gravel, sand and voids have different scales, so that the overall behavior of the concrete is obtained by the composition of three different homogenizations; in the sense that the concrete is regarded as the homogenized material of the two-phase composite constituted of the gravel and the mortar; in turn, the mortar is the homogenized material of the two-phase composite constituted of the sand inclusions and a (porous cement paste matrix; finally, the (porous cement paste is the homogenized material of the two-phase composite constituted of voids and the pure paste. The pure paste represents the cement paste before the loading process, so that it does not contain voids or other defects due to the loading process. The abovementioned three homogenizations are realized with the predictive scheme of Mori-Tanaka in conjunction with the Eshelby method. The adopted model can be considered an attempt to find micromechanical tools able to capture peculiar aspects of the cement concrete in load cases of uni-axial and multi-axial compression. Attributing the non-linear behavior of concrete to the creation of equivalent voids in the cement paste provides correspondence with many phenomenological aspects of concrete behavior. Trying to improve this correspondence, the influence of the parameters of the

  2. A Bayesian network approach for modeling local failure in lung cancer

    International Nuclear Information System (INIS)

    Oh, Jung Hun; Craft, Jeffrey; Al Lozi, Rawan; Vaidya, Manushka; Meng, Yifan; Deasy, Joseph O; Bradley, Jeffrey D; El Naqa, Issam

    2011-01-01

    Locally advanced non-small cell lung cancer (NSCLC) patients suffer from a high local failure rate following radiotherapy. Despite many efforts to develop new dose-volume models for early detection of tumor local failure, there was no reported significant improvement in their application prospectively. Based on recent studies of biomarker proteins' role in hypoxia and inflammation in predicting tumor response to radiotherapy, we hypothesize that combining physical and biological factors with a suitable framework could improve the overall prediction. To test this hypothesis, we propose a graphical Bayesian network framework for predicting local failure in lung cancer. The proposed approach was tested using two different datasets of locally advanced NSCLC patients treated with radiotherapy. The first dataset was collected retrospectively, which comprises clinical and dosimetric variables only. The second dataset was collected prospectively in which in addition to clinical and dosimetric information, blood was drawn from the patients at various time points to extract candidate biomarkers as well. Our preliminary results show that the proposed method can be used as an efficient method to develop predictive models of local failure in these patients and to interpret relationships among the different variables in the models. We also demonstrate the potential use of heterogeneous physical and biological variables to improve the model prediction. With the first dataset, we achieved better performance compared with competing Bayesian-based classifiers. With the second dataset, the combined model had a slightly higher performance compared to individual physical and biological models, with the biological variables making the largest contribution. Our preliminary results highlight the potential of the proposed integrated approach for predicting post-radiotherapy local failure in NSCLC patients.

  3. Metabolic Response on Post-therapy FDG-PET Predicts Patterns of Failure After Radiotherapy for Cervical Cancer

    International Nuclear Information System (INIS)

    Schwarz, Julie K.; Siegel, Barry A.; Dehdashti, Farrokh; Grigsby, Perry W.

    2012-01-01

    Purpose: To determine the patterns of failure in patients with cervical cancer treated with definitive radiotherapy and evaluated for metabolic response with early posttherapy 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET). Methods and Materials: The records of 238 patients with cervical cancer were reviewed. All patients were treated with a combination of external radiotherapy and intracavitary brachytherapy. Two hundred and nineteen patients (92%) received concurrent chemotherapy. All patients underwent pretreatment FDG-PET, and posttherapy FDG-PET was performed within 8–16 weeks of the completion of radiotherapy. Posttherapy FDG-PET results were categorized as complete metabolic response (CMR), partial metabolic response (PMR), and progressive disease (PD). Failure patterns were categorized as none, isolated local failure (central pelvis ± pelvic lymph nodes), distant failure, or combined local plus distant failure. Results: Of the 91 patients (38%) who had a recurrence, 22 had isolated local failures, and 69 had distant failures (49 distant failures and 20 combined local plus distant failures). Of the 173 patients with a CMR, 40 (23%) experienced treatment failure. All 25 patients with PD experienced treatment failure, which was distant in 24 patients (96%). Among the 40 patients with PMR, no failure has been observed for 14 patients (35%). Of the 26 failures within the PMR group, 15 (58%) were limited to the pelvis. Differences in the patterns of failure between the three groups (CMR, PMR, PD) were statistically significant (chi-square test; p < 0.0001). Conclusions: The majority of failures after definitive radiotherapy for cervical cancer include distant failures, even in the setting of concurrent chemotherapy. PMR within the cervix or lymph nodes is more commonly associated with isolated local recurrence.

  4. Nonlinear piping damping and response predictions

    International Nuclear Information System (INIS)

    Severud, L.K.; Weiner, E.O.; Lindquist, M.R.; Anderson, M.J.; Wagner, S.E.

    1986-10-01

    The high level dynamic testing of four prototypic piping systems, used to provide benchmarks for analytical prediction comparisons, is overviewed. The size of pipe tested ranged from one-inch to six-inches in diameter and consisted of carbon steel or stainless steel material. Failure of the tested systems included progressive gross deformation or some combination of ratchetting-fatigue. Pretest failure predictions and post test comparisons using simplified elastic and elasto-plastic methods are presented. Detailed non-linear inelastic analyses are also shown, along with a typical ratchet-fatigue failure calculation. A simplified method for calculating modal equivalent viscous damping for snubbers and plastic hinges is also described. Conclusions are made regarding the applicability of the various analytical failure predictive methods and recommendations are made for future analytic and test efforts

  5. Nanowire failure: long = brittle and short = ductile.

    Science.gov (United States)

    Wu, Zhaoxuan; Zhang, Yong-Wei; Jhon, Mark H; Gao, Huajian; Srolovitz, David J

    2012-02-08

    Experimental studies of the tensile behavior of metallic nanowires show a wide range of failure modes, ranging from ductile necking to brittle/localized shear failure-often in the same diameter wires. We performed large-scale molecular dynamics simulations of copper nanowires with a range of nanowire lengths and provide unequivocal evidence for a transition in nanowire failure mode with change in nanowire length. Short nanowires fail via a ductile mode with serrated stress-strain curves, while long wires exhibit extreme shear localization and abrupt failure. We developed a simple model for predicting the critical nanowire length for this failure mode transition and showed that it is in excellent agreement with both the simulation results and the extant experimental data. The present results provide a new paradigm for the design of nanoscale mechanical systems that demarcates graceful and catastrophic failure. © 2012 American Chemical Society

  6. Prediction factors for failure to seek treatment following traumatic dental injuries to primary teeth

    Directory of Open Access Journals (Sweden)

    Ramon Targino Firmino

    2014-06-01

    Full Text Available The objective of this study was to evaluate prediction factors for failure to seek treatment following a traumatic dental injury (TDI to primary teeth among preschool children in the city of Campina Grande, Brazil. A cross-sectional study was carried out involving 277 children 3 to 5 years of age, with TDI, enrolled in public and private preschools. Parents filled out a form addressing demographic data and whether or not they had sought treatment. Clinical examinations were performed by three dentists who had undergone a calibration exercise (Kappa: 0.85 to 0.90 for the evaluation of TDI. Bivariate and multivariate Poisson regression models were constructed (α = 5%. Enamel fracture was the most prevalent type of TDI (48.7% and the upper central incisors were the most affected teeth (88.4%. The frequency of seeking dental treatment was low (9.7%. The following variables were associated with failure to seek treatment following TDI: a household income greater than one minimum wage (PR = 1.170; 95%CI 1.018-1.341, parents/caregivers’ perception of a child’s oral health as poor (PR = 1.100; 95%CI 1.026-1.176, and the non-perception of TDI by parents/caregivers (PR = 1.250; 95%CI 1.142-1.360. In the present study, the frequency of seeking treatment following TDI was low, and parents/caregivers with a higher income, a poor perception of their child’s oral health and a lack of awareness regarding the trauma were more likely to fail to seek treatment following TDI to primary teeth.

  7. Validation of the kidney failure risk equation in European CKD patients

    NARCIS (Netherlands)

    Peeters, M.J.; Zuilen, A.D. van; Brand, A. van den; Bots, M.L.; Blankestijn, P.J.; Wetzels, J.F.M.; Vervoort, G.M.M.; et al.,

    2013-01-01

    BACKGROUND: Patients with chronic kidney disease (CKD) are at risk for progression to kidney failure. Using data of Canadian CKD patients, Tangri et al. recently developed models to predict the progression of CKD stages 3-5 to kidney failure within 5 years. We validated this kidney failure risk

  8. Predictive biomarkers for death and rehospitalization in comorbid frail elderly heart failure patients.

    Science.gov (United States)

    Pacho, Cristina; Domingo, Mar; Núñez, Raquel; Lupón, Josep; Núñez, Julio; Barallat, Jaume; Moliner, Pedro; de Antonio, Marta; Santesmases, Javier; Cediel, Germán; Roura, Santiago; Pastor, M Cruz; Tor, Jordi; Bayes-Genis, Antoni

    2018-05-09

    Heart failure (HF) is associated with a high rate of readmissions within 30 days post-discharge and in the following year, especially in frail elderly patients. Biomarker data are scarce in this high-risk population. This study assessed the value of early post-discharge circulating levels of ST2, NT-proBNP, CA125, and hs-TnI for predicting 30-day and 1-year outcomes in comorbid frail elderly patients with HF with mainly preserved ejection fraction (HFpEF). Blood samples were obtained at the first visit shortly after discharge (4.9 ± 2 days). The primary endpoint was the composite of all-cause mortality or HF-related rehospitalization at 30 days and at 1 year. All-cause mortality alone at one year was also a major endpoint. HF-related rehospitalizations alone were secondary end-points. From February 2014 to November 2016, 522 consecutive patients attending the STOP-HF Clinic were included (57.1% women, age 82 ± 8.7 years, mean Barthel index 70 ± 25, mean Charlson comorbidity index 5.6 ± 2.2). The composite endpoint occurred in 8.6% patients at 30 days and in 38.5% at 1 year. In multivariable analysis, ST2 [hazard ratio (HR) 1.53; 95% CI 1.19-1.97; p = 0.001] was the only predictive biomarker at 30 days; at 1 year, both ST2 (HR 1.34; 95% CI 1.15-1.56; p < 0.001) and NT-proBNP (HR 1.19; 95% CI 1.02-1.40; p = 0.03) remained significant. The addition of ST2 and NT-proBNP into a clinical predictive model increased the AUC from 0.70 to 0.75 at 30 days (p = 0.02) and from 0.71 to 0.74 at 1 year (p < 0.05). For all-cause death at 1 year, ST2 (HR 1.50; 95% CI 1.26-1.80; p < 0.001), and CA125 (HR 1.41; 95% CI 1.21-1.63; p < 0.001) remained independent predictors in multivariable analysis. The addition of ST2 and CA125 into a clinical predictive model increased the AUC from 0.74 to 0.78 (p = 0.03). For HF-related hospitalizations, ST2 was the only predictive biomarker in multivariable analyses, both at 30

  9. Amyotrophic lateral sclerosis: the Midwestern surgical experience with the diaphragm pacing stimulation system shows that general anesthesia can be safely performed.

    Science.gov (United States)

    Onders, Raymond P; Carlin, Arthur M; Elmo, MaryJo; Sivashankaran, Subhalakashmi; Katirji, Bashar; Schilz, Robert

    2009-03-01

    There is a paucity of literature concerning general anesthesia and surgery in patients with amyotrophic lateral sclerosis (ALS or Lou Gehrig's disease). This report summarizes the largest series of surgical cases in ALS during multicenter prospective trials of the laparoscopic diaphragm pacing system (DPS) to delay respiratory failure. The overall strategy outlined includes the use of rapidly reversible short-acting analgesic and amnestic agents with no neuromuscular relaxants. Fifty-one patients were implanted from March 2005 to March 2008 at 2 sites. Age at implantation ranged from 42 to 73 years and the percent predicted forced vital capacity (FVC) ranged from 20% to 87%. On preoperative blood gases, Pco(2) was as high as 60. Using this protocol, there were no failures to extubate or 30-day mortalities. The DPS system increases the respiratory system compliance by decreasing posterior lobe atelectasis and can stimulate respirations at the end of each case. Laparoscopic surgery with general anesthesia can be safely performed in patients with ALS undergoing DPS.

  10. Nurses' attitudes toward family importance in heart failure care.

    Science.gov (United States)

    Gusdal, Annelie K; Josefsson, Karin; Thors Adolfsson, Eva; Martin, Lene

    2017-03-01

    Support from the family positively affects self-management, patient outcomes and the incidence of hospitalizations among patients with heart failure. To involve family members in heart failure care is thus valuable for the patients. Registered nurses frequently meet family members of patients with heart failure and the quality of these encounters is likely to be influenced by the attitudes registered nurses hold toward families. To explore registered nurses' attitudes toward the importance of families' involvement in heart failure nursing care and to identify factors that predict the most supportive attitudes. Cross-sectional, multicentre web-survey study. A sample of 303 registered nurses from 47 hospitals and 30 primary health care centres completed the instrument Families' Importance in Nursing Care - Nurses' Attitudes. Overall, registered nurses were supportive of families' involvement. Nonetheless, attitudes toward inviting families to actively take part in heart failure nursing care and involve families in planning of care were less supportive. Factors predicting the most supportive attitudes were to work in a primary health care centre, a heart failure clinic, a workplace with a general approach toward families, to have a postgraduate specialization, education in cardiac and/or heart failure nursing care, and a competence to work with families. Experienced registered nurses in heart failure nursing care can be encouraged to mentor their younger and less experienced colleagues to strengthen their supportive attitudes toward families. Registered nurses who have designated consultation time with patients and families, as in a nurse-led heart failure clinic, may have the most favourable condition for implementing a more supportive approach to families.

  11. A new model for anisotropic damage in concrete and its application to the prediction of failure of some containment vessel

    International Nuclear Information System (INIS)

    Badel, P.-B.; Godard, V.; Leblond, J.-B.

    2005-01-01

    The aim of this paper is to propose a new model for damage in concrete structures which incorporates such complex features as damage anisotropy and asymmetry between tension and compression, while being expressed in a format well suited for numerical applications and involving a limited number of material parameters which can be determined from standard experiments. A crude version of the model involving a single tonsorial internal variable representing damage in tension, and a single material parameter, is presented first. The predictions of this simple model are satisfactory in simple tension, but not so in simple compression. As a remedy, various refinements are then introduced in a second version of the model involving an additional tonsorial or scalar internal variable representing damage in compression, and five additional material parameters. An example of determination of the model parameters using experimental stress-strain curves in simple tension and compression, plus failure envelopes in biaxial tension/compression, is presented next. The model is finally applied to the numerical prediction of the failure of some containment vessel subjected to some large internal pressure, with a comparison with calculations based on a simpler isotropic variant of the model using a single scalar damage variable. The results illustrate the relevance of models incorporating both asymmetry between tension and compression and anisotropy of damage for simulations of industrial concrete structures. (authors)

  12. Most likely failure location during severe accident conditions

    International Nuclear Information System (INIS)

    Rempe, J.L.; Allison, C.M.

    1991-01-01

    This paper describes preliminary results from which finite element calculation results are used in conjunction with analytical calculation results to predict failure in different LWR vessel designs during a severe accident. Detailed analyses are being performed to investigate the relative likelihood of a BWR vessel and drain line penetration to fail during a wide range of severe accident conditions. Analytically developed failure maps, which were developed in terms of dimensionless groups, are applied to consider geometries and materials occurring in other LWR vessel designs. Preliminary numerical analysis results indicate that if ceramic debris relocates within the BWR drain line to a distance below the lower head, the drain line will reach failure temperatures before the vessel fails. Application of failure maps for these debris conditions to other LWR geometries indicate that in-vessel tube melting will occur in either BWR or PWR vessel designs. Furthermore, if this melt is assumed to fill the entire penetration flow area, the melt is predicted to travel well below the lower head in any of the reference LWR penetrations. However, failure maps suggest the result that ex-vessel tube temperatures exceed the penetration's ultimate strength is specific to the BWR drain line because of its material composition and relatively large effective diameter for melt flow

  13. The use of postoperative slit-lamp optical coherence tomography to predict primary failure in descemet stripping automated endothelial keratoplasty.

    Science.gov (United States)

    Shih, Carolyn Y; Ritterband, David C; Palmiero, Pat-Michael; Seedor, John A; Papachristou, George; Harizman, Noga; Liebmann, Jeffrey M; Ritch, Robert

    2009-05-01

    To determine if central donor lenticle thickness as measured by slit-lamp optical coherence tomography (SL OCT; Heidelberg Engineering, Heidelberg, Germany) is predictive of primary donor failure in patients undergoing Descemet stripping automated endothelial keratoplasty (DSAEK). Retrospective cross-sectional study. Eighty-four patients who underwent DSAEK surgery by 2 surgeons (D.C.R. and J.A.S.) were enrolled. At each postoperative visit (postoperative day 1, week 1, month 1, and month 2), an SL OCT scan was obtained. Statistical differences in SL OCT measurements of successful and failed DSAEK procedures were measured using the Student t test. A successful DSAEK surgery was defined as having an anatomically attached, clear recipient corneal stroma and donor lenticle compatible with good vision 2 months after surgery. A failed DSAEK surgery was defined as an attached donor lenticle with SL evidence of corneal edema and thickening visible at 2 months or more. Ninety-three eyes of 84 consecutive patients who underwent DSAEK surgery also underwent postoperative SL OCT. After 2 months of follow-up, 82 (88%) procedures were successful and 11 (12%) procedures were failures. The average donor lenticle thickness in successful DSAEK eyes was 314 +/- 128 microm on postoperative day 1 as compared with failed DSAEK eyes, which averaged 532 +/- 259 microm (P = .0013). This was independent regardless of whether the lenticle was attached on the first postoperative visit. Seventy-nine (98%) successful DSAEK eyes had a lenticle thickness of or = 350 microm at the 1-week postoperative visit. Statistically significant differences in SL OCT thickness measurements were seen between successful and failed DSAEK cases at all examinations after postoperative week 1. Corneal thickness measurements made with SL OCT are an important predictor of DSAEK failure in both attached and detached lenticles within the first week of surgery. DSAEK lenticle thickness of 350 microm or less at 1 week

  14. Utility of CD4 cell counts for early prediction of virological failure during antiretroviral therapy in a resource-limited setting

    Directory of Open Access Journals (Sweden)

    Lawn Stephen D

    2008-07-01

    Full Text Available Abstract Background Viral load monitoring is not available for the vast majority of patients receiving antiretroviral therapy in resource-limited settings. However, the practical utility of CD4 cell count measurements as an alternative monitoring strategy has not been rigorously assessed. Methods In this study, we used a novel modelling approach that accounted for all CD4 cell count and VL values measured during follow-up from the first date that VL suppression was achieved. We determined the associations between CD4 counts (absolute values and changes during ART, VL measurements and risk of virological failure (VL > 1,000 copies/ml following initial VL suppression in 330 patients in South Africa. CD4 count changes were modelled both as the difference from baseline (ΔCD4 count and the difference between consecutive values (CD4 count slope using all 3-monthly CD4 count measurements during follow-up. Results During 7093.2 patient-months of observation 3756 paired CD4 count and VL measurements were made. In patients who developed virological failure (n = 179, VL correlated significantly with absolute CD4 counts (r = - 0.08, P = 0.003, ΔCD4 counts (r = - 0.11, P P P = 0.99, P = 0.92 and P = 0.75, respectively. Moreover, in a receiver operating characteristic (ROC curve, the association between a negative CD4 count slope and virological failure was poor (area under the curve = 0.59; sensitivity = 53.0%; specificity = 63.6%; positive predictive value = 10.9%. Conclusion CD4 count changes correlated significantly with VL at group level but had very limited utility in identifying virological failure in individual patients. CD4 count is an inadequate alternative to VL measurement for early detection of virological failure.

  15. Ambient seismic noise monitoring of a clay landslide: Toward failure prediction

    Science.gov (United States)

    Mainsant, Guénolé; Larose, Eric; Brönnimann, Cornelia; Jongmans, Denis; Michoud, Clément; Jaboyedoff, Michel

    2012-03-01

    Given that clay-rich landslides may become mobilized, leading to rapid mass movements (earthflows and debris flows), they pose critical problems in risk management worldwide. The most widely proposed mechanism leading to such flow-like movements is the increase in water pore pressure in the sliding mass, generating partial or complete liquefaction. This solid-to-liquid transition results in a dramatic reduction of mechanical rigidity in the liquefied zones, which could be detected by monitoring shear wave velocity variations. With this purpose in mind, the ambient seismic noise correlation technique has been applied to measure the variation in the seismic surface wave velocity in the Pont Bourquin landslide (Swiss Alps). This small but active composite earthslide-earthflow was equipped with continuously recording seismic sensors during spring and summer 2010. An earthslide of a few thousand cubic meters was triggered in mid-August 2010, after a rainy period. This article shows that the seismic velocity of the sliding material, measured from daily noise correlograms, decreased continuously and rapidly for several days prior to the catastrophic event. From a spectral analysis of the velocity decrease, it was possible to determine the location of the change at the base of the sliding layer. These results demonstrate that ambient seismic noise can be used to detect rigidity variations before failure and could potentially be used to predict landslides.

  16. CMR in Heart Failure.

    OpenAIRE

    Sado, D. M.; Hasleton, J. M.; Herrey, A. S.; Moon, J. C.

    2011-01-01

    Heart Failure (HF) is a common syndrome with multiple causes. Cardiovascular magnetic resonance (CMR) is a medical imaging technique with significant advantages, allowing the understanding of aetiology and pathophysiology of HF in the individual patient, permitting specific therapy to be administered and predicting prognosis. This paper discusses the diverse role of CMR in HF.

  17. Patient Characteristics Predicting Readmission Among Individuals Hospitalized for Heart Failure

    Science.gov (United States)

    O'Connor, Melissa; Murtaugh, Christopher M.; Shah, Shivani; Barrón-Vaya, Yolanda; Bowles, Kathryn H.; Peng, Timothy R.; Zhu, Carolyn W.; Feldman, Penny H.

    2015-01-01

    Heart failure is difficult to manage and increasingly common with many individuals experiencing frequent hospitalizations. Little is known about patient factors consistently associated with hospital readmission. A literature review was conducted to identify heart failure patient characteristics, measured before discharge, that contribute to variation in hospital readmission rates. Database searches yielded 950 potential articles, of which 34 studies met inclusion criteria. Patient characteristics generally have a very modest effect on all-cause or heart failure–related readmission within 7 to 180 days of index hospital discharge. A range of cardiac diseases and other comorbidities only minimally increase readmission rates. No single patient characteristic stands out as a key contributor across multiple studies underscoring the challenge of developing successful interventions to reduce readmissions. Interventions may need to be general in design with the specific intervention depending on each patient's unique clinical profile. PMID:26180045

  18. Prediction of yield and long-term failure of oriented polypropylene: kinetics and anisotropy

    NARCIS (Netherlands)

    van Erp, T.B.; Reynolds, C.T.; Peijs, T.; van Dommelen, J.A.W.; Govaert, L.E.

    2009-01-01

    The time-dependent yield and failure behavior of off-axis loaded uniaxially oriented polypropy-lene tape is investigated. The yield and failure behavior is described with an anisotropic vis-coplastic model. A viscoplastic flow rule is used with an equivalent stress, based on Hill’sanisotropic yield

  19. Ductile failure analysis of API X65 pipes with notch-type defects using a local fracture criterion

    International Nuclear Information System (INIS)

    Oh, Chang-Kyun; Kim, Yun-Jae; Baek, Jong-Hyun; Kim, Young-Pyo; Kim, Woo-Sik

    2007-01-01

    A local failure criterion for API X65 steel is applied to predict ductile failure of full-scale API X65 pipes with simulated corrosion and gouge defects under internal pressure. The local failure criterion is the stress-modified fracture strain as a function of the stress triaxiality (defined by the ratio of the hydrostatic stress to the effective stress). Based on detailed finite element (FE) analyses with the proposed local failure criterion, burst pressures of defective pipes are estimated and compared with experimental data. For pipes with simulated corrosion defects, FE analysis with the proposed local fracture criterion indicates that predicted failure takes place after the defective pipes attain maximum loads for all cases, possibly due to the fact that the material has sufficient ductility. For pipes with simulated gouge defects, on the other hand, it is found that predicted failure takes place before global instability, and the predicted burst pressures are in good agreement with experimental data, providing confidence in the present approach

  20. Diuretics as pathogenetic treatment for heart failure

    Science.gov (United States)

    Guglin, Maya

    2011-01-01

    Increased intracardiac filling pressure or congestion causes symptoms and leads to hospital admissions in patients with heart failure, regardless of their systolic function. A history of hospital admission, in turn, predicts further hospitalizations and morbidity, and a higher number of hospitalizations determine higher mortality. Congestion is therefore the driving force of the natural history of heart failure. Congestion is the syndrome shared by heart failure with preserved and reduced systolic function. These two conditions have almost identical morbidity, mortality, and survival because the outcomes are driven by congestion. A small difference in favor of heart failure with preserved systolic function comes from decreased ejection fraction and left ventricular remodeling which is only present in heart failure with decreased systolic function. The magnitude of this difference reflects the contribution of decreased systolic function and ventricular remodeling to the progression of heart failure. The only treatment available for congestion is fluid removal via diuretics, ultrafiltration, or dialysis. It is the only treatment that works equally well for heart failure with reduced and preserved systolic function because it affects congestion, the main pathogenetic feature of the disease. Diuretics are pathogenetic therapy for heart failure. PMID:21403798

  1. The conservatism of the net-section stress procedure for predicting the failure of cracked piping systems: the effect of crack shape complexity on the degree of conservatism

    International Nuclear Information System (INIS)

    Smith, E.

    1996-01-01

    The failure of circumferentially cracked steel piping is often predicted by assuming that failure conforms to a net-section stress criterion using as input an appropriate value for the critical net-section stress together with a knowledge of the anticipated loadings. The stress at the cracked section is usually calculated via a purely elastic analysis based on the piping being uncracked. however, because the piping is built-in at the ends into a larger component, and since the onset of crack extension requires some plastic deformation, use of the net-section stress approach can give overly conservative failure predictions. In earlier work, the author has quantified the extent of this conservatism, and has shown how it depends on the geometry of the cracked section, the material ductility and the elastic flexibility of a piping system. This paper quantifies the conservatism with regard to the case where a through-wall crack extends over a prescribed fraction of the pipe circumference, while there is also an internal circumferential crack extending around the remainder of the pipe section. This is an extreme form of circumferential cracking but nevertheless, simulates the well-known Duane Arnold safe-end crack. (Author)

  2. Driven by fear: the effect of success and failure information on passionate individuals' performance.

    Science.gov (United States)

    Bélanger, Jocelyn J; Lafrenière, Marc-André K; Vallerand, Robert J; Kruglanski, Arie W

    2013-01-01

    Four studies investigated the impact of success and failure information on passionate individuals' performance. Obsessive passion, characterized by a rigid and defensive mode of functioning, predicted greater performance in domains both related and unrelated to the passionate activity in response to exposure to failure information. Conversely, harmonious passion, characterized by a flexible, nondefensive mode of functioning, was found to be unaffected by success or failure information. These performance effects were deeply ingrained, did not require conscious thought, and were automatically activated after unconscious exposure to failure-related words. In addition, the present research evinced that following failure information, obsessive passion predicted increases of performance through its effect on fear of failure. However, performance augmented only when the performance task was framed in such a way that failure would entail important negative consequences for the self and not when framed as inconsequential.

  3. Developing EHR-driven heart failure risk prediction models using CPXR(Log) with the probabilistic loss function.

    Science.gov (United States)

    Taslimitehrani, Vahid; Dong, Guozhu; Pereira, Naveen L; Panahiazar, Maryam; Pathak, Jyotishman

    2016-04-01

    Computerized survival prediction in healthcare identifying the risk of disease mortality, helps healthcare providers to effectively manage their patients by providing appropriate treatment options. In this study, we propose to apply a classification algorithm, Contrast Pattern Aided Logistic Regression (CPXR(Log)) with the probabilistic loss function, to develop and validate prognostic risk models to predict 1, 2, and 5year survival in heart failure (HF) using data from electronic health records (EHRs) at Mayo Clinic. The CPXR(Log) constructs a pattern aided logistic regression model defined by several patterns and corresponding local logistic regression models. One of the models generated by CPXR(Log) achieved an AUC and accuracy of 0.94 and 0.91, respectively, and significantly outperformed prognostic models reported in prior studies. Data extracted from EHRs allowed incorporation of patient co-morbidities into our models which helped improve the performance of the CPXR(Log) models (15.9% AUC improvement), although did not improve the accuracy of the models built by other classifiers. We also propose a probabilistic loss function to determine the large error and small error instances. The new loss function used in the algorithm outperforms other functions used in the previous studies by 1% improvement in the AUC. This study revealed that using EHR data to build prediction models can be very challenging using existing classification methods due to the high dimensionality and complexity of EHR data. The risk models developed by CPXR(Log) also reveal that HF is a highly heterogeneous disease, i.e., different subgroups of HF patients require different types of considerations with their diagnosis and treatment. Our risk models provided two valuable insights for application of predictive modeling techniques in biomedicine: Logistic risk models often make systematic prediction errors, and it is prudent to use subgroup based prediction models such as those given by CPXR

  4. Endoscopic third ventriculostomy with choroid plexus cauterization outcome: distinguishing success from failure.

    Science.gov (United States)

    Dewan, Michael C; Lim, Jaims; Morgan, Clinton D; Gannon, Stephen R; Shannon, Chevis N; Wellons, John C; Naftel, Robert P

    2016-12-01

    OBJECTIVE Endoscopic third ventriculostomy with choroid plexus cauterization (ETV/CPC) offers an alternative to shunt treatment for infantile hydrocephalus. Diagnosing treatment failure is dependent on infantile hydrocephalus metrics, including head circumference, fontanel quality, and ventricle size. However, it is not clear to what degree these metrics should be expected to change after ETV/CPC. Using these clinical metrics, the authors present and analyze the decision making in cases of ETV/CPC failure. METHODS Infantile hydrocephalus metrics, including bulging fontanel, head circumference z-score, and frontal and occipital horn ratio (FOHR), were compared between ETV/CPC failures and successes. Treatment outcome predictive values of metrics individually and in combination were calculated. RESULTS Forty-four patients (57% males, median age 1.2 months) underwent ETV/CPC for hydrocephalus; of these patients, 25 (57%) experienced failure at a median time of 51 days postoperatively. Patients experiencing failure were younger than those experiencing successful treatment (0.8 vs 3.9 months, p = 0.01). During outpatient follow-up, bulging anterior fontanel, progressive macrocephaly, and enlarging ventricles each demonstrated a positive predictive value (PPV) of no less than 71%, but a bulging anterior fontanel remained the most predictive indicator of ETV/CPC failure, with a PPV of 100%, negative predictive value of 73%, and sensitivity of 72%. The highest PPVs and specificities existed when the clinical metrics were present in combination, although sensitivities decreased expectedly. Only 48% of failures were diagnosed on the basis all 3 hydrocephalus metrics, while only 37% of successes were negative for all 3 metrics. In the remaining 57% of patients, a diagnosis of success or failure was made in the presence of discordant data. CONCLUSIONS Successful ETV/CPC for infantile hydrocephalus was evaluated in relation to fontanel status, head growth, and change in

  5. Failure analysis and failure prevention in electric power systems

    International Nuclear Information System (INIS)

    Rau, C.A. Jr.; Becker, D.G.; Besuner, P.M.; Cipolla, R.C.; Egan, G.R.; Gupta, P.; Johnson, D.P.; Omry, U.; Tetelman, A.S.; Rettig, T.W.; Peters, D.C.

    1977-01-01

    New methods have been developed and applied to better quantify and increase the reliability, safety, and availability of electric power plants. Present and potential problem areas have been identified both by development of an improved computerized data base of malfunctions in nuclear power plants and by detailed metallurgical and mechanical failure analyses of selected problems. Significant advances in the accuracy and speed of structural analyses have been made through development and application of the boundary integral equation and influence function methods of stress and fracture mechanics analyses. The currently specified flaw evaluation procedures of the ASME Boiler and Pressure Vessel Code have been computerized. Results obtained from these procedures for evaluation of specific in-service inspection indications have been compared with results obtained utilizing the improved analytical methods. Mathematical methods have also been developed to describe and analyze the statistical variations in materials properties and in component loading, and uncertainties in the flaw size that might be passed by quality assurance systems. These new methods have been combined to develop accurate failure rate predictions based upon probabilistic fracture mechanics. Improved failure prevention strategies have been formulated by combining probabilistic fracture mechanics and cost optimization techniques. The approach has been demonstrated by optimizing the nondestructive inspection level with regard to both reliability and cost. (Auth.)

  6. Perineural invasion on prostate needle biopsy does not predict biochemical failure following brachytherapy for prostate cancer

    International Nuclear Information System (INIS)

    Weight, Christopher J.; Ciezki, Jay P.; Reddy, Chandana A.; Zhou Ming; Klein, Eric A.

    2006-01-01

    Purpose: To determine if the presence of perineural invasion (PNI) predicts biochemical recurrence in patients who underwent low-dose-rate brachytherapy for the treatment of localized prostate cancer. Methods and Materials: A retrospective case control matching study was performed. The records of 651 patients treated with brachytherapy between 1996 and 2003 were reviewed. Sixty-three of these patients developed biochemical failure. These sixty-three patients were then matched in a one-to-one ratio to patients without biochemical failure, controlling for biopsy Gleason score, clinical stage, initial prostate-specific antigen, age, and the use of androgen deprivation. The pathology of the entire cohort was then reviewed for evidence of perineural invasion on initial prostate biopsy specimens. The biochemical relapse free survival rates for these two groups were compared. Results: Cases and controls were well matched, and there were no significant differences between the two groups in age, Gleason grade, clinical stage, initial prostate-specific antigen, and the use of androgen deprivation. PNI was found in 19 (17%) patients. There was no significant difference in the rates of PNI between cases and controls, 19.6% and 14.3% respectively (p 0.45). PNI did not correlate with biochemical relapse free survival (p 0.40). Conclusion: Perineural invasion is not a significant predictor of biochemical recurrence in patients undergoing brachytherapy for prostate cancer

  7. Positive predictive value and impact of misdiagnosis of a heart failure diagnosis in administrative registers among patients admitted to a University Hospital cardiac care unit

    DEFF Research Database (Denmark)

    Mard, Shan; Nielsen, Finn Erland

    2010-01-01

    OBJECTIVE: To evaluate the positive predictive value (PPV) of a diagnosis of heart failure (HF) in the Danish National Registry of Patients (NRP) among patients admitted to a University Hospital cardiac care unit, and to evaluate the impact of misdiagnosing HF. DESIGN: The NRP was used to identify...

  8. How to Predict Oral Rehydration Failure in Children With Gastroenteritis

    NARCIS (Netherlands)

    D.H.F. Geurts (Dorien); E.W. Steyerberg (Ewout); H.A. Moll (Henriëtte); R. Oostenbrink (Rianne)

    2017-01-01

    textabstractOBJECTIVES:: Oral rehydration is the standard in most current guidelines for young children with acute gastroenteritis (AGE). Failure of oral rehydration can complicate the disease course, leading to morbidity due to severe dehydration. We aimed to identify prognostic factors of oral

  9. Predicting kidney graft failure using time-dependent renal function covariates

    NARCIS (Netherlands)

    de Bruijne, Mattheus H. J.; Sijpkens, Yvo W. J.; Paul, Leendert C.; Westendorp, Rudi G. J.; van Houwelingen, Hans C.; Zwinderman, Aeilko H.

    2003-01-01

    Chronic rejection and recurrent disease are the major causes of late graft failure in renal transplantation. To assess outcome, most researchers use Cox proportional hazard analysis with time-fixed covariates. We developed a model adding time-dependent renal function covariates to improve the

  10. Peak Exercise Oxygen Uptake Predicts Recurrent Admissions in Heart Failure With Preserved Ejection Fraction.

    Science.gov (United States)

    Palau, Patricia; Domínguez, Eloy; Núñez, Eduardo; Ramón, José María; López, Laura; Melero, Joana; Sanchis, Juan; Bellver, Alejandro; Santas, Enrique; Bayes-Genis, Antoni; Chorro, Francisco J; Núñez, Julio

    2018-04-01

    Heart failure with preserved ejection fraction (HFpEF) is a highly prevalent syndrome with an elevated risk of morbidity and mortality. To date, there is scarce evidence on the role of peak exercise oxygen uptake (peak VO 2 ) for predicting the morbidity burden in HFpEF. We sought to evaluate the association between peak VO 2 and the risk of recurrent hospitalizations in patients with HFpEF. A total of 74 stable symptomatic patients with HFpEF underwent a cardiopulmonary exercise test between June 2012 and May 2016. A negative binomial regression method was used to determine the association between the percentage of predicted peak VO 2 (pp-peak VO 2 ) and recurrent hospitalizations. Risk estimates are reported as incidence rate ratios. The mean age was 72.5 ± 9.1 years, 53% were women, and all patients were in New York Heart Association functional class II to III. Mean peak VO 2 and median pp-peak VO 2 were 10 ± 2.8mL/min/kg and 60% (range, 47-67), respectively. During a median follow-up of 276 days [interquartile range, 153-1231], 84 all-cause hospitalizations in 31 patients (41.9%) were registered. A total of 15 (20.3%) deaths were also recorded. On multivariate analysis, accounting for mortality as a terminal event, pp-peak VO 2 was independently and linearly associated with the risk of recurrent admission. Thus, and modeled as continuous, a 10% decrease of pp-peak VO 2 increased the risk of recurrent hospitalizations by 32% (IRR, 1.32; 95%CI, 1.03-1.68; P = .028). In symptomatic elderly patients with HFpEF, pp-peak VO 2 predicts all-cause recurrent admission. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  11. Difficult to predict early failure after major lower-extremity amputations

    DEFF Research Database (Denmark)

    Kristensen, Morten Tange; Holm, Gitte; Gebuhr, Peter

    2015-01-01

    INTRODUCTION: The successful outcome of a major amputation depends on several factors, including stump wound healing. The purpose of this study was to examine the criteria upon which the index amputation was based and to identify factors associated with early amputation failure after major non......-traumatic lower-extremity amputation. METHODS: We studied a consecutive one-year series of 36 men and 34 women with a median (25-75% quartiles) age of 72 (63-83) years who were treated in an acute orthopaedic ward; 44 below-knee and 26 above-knee amputees of whom 47 had an American Society of Anesthesiologists...... rating above two. Patient characteristics and other factors potentially influencing early amputation failure within 30 days were evaluated. RESULTS: Eleven patients died (16%) and 11 (16%) had a re-amputation at a higher level, whereas four (6%) had a major revision at the same level within 30 days...

  12. Failure and nonfailure of fluid filaments in extension

    DEFF Research Database (Denmark)

    Hassager, Ole; Kolte, Mette Irene; Renardy, Michael

    1998-01-01

    The phenomenon of ductile failure of Newtonian and viscoelastic fluid filaments without surface tension is studied by a 2D finite element method and by ID non-linear analysis. The viscoelastic fluids are described by single integral constitutive equations. The main conclusions are: (1) Newtonian...... fluid filaments do not exhibit ductile failure without surface tension; (2) some viscoelastic fluids form stable filaments while other fluids exhibit ductile failure as a result of an elastic instability; (3) for large Deborah numbers, the Considere condition may be used to predict the Hencky strain...

  13. Association between Functional Variables and Heart Failure after Myocardial Infarction in Rats

    Energy Technology Data Exchange (ETDEWEB)

    Polegato, Bertha F.; Minicucci, Marcos F.; Azevedo, Paula S.; Gonçalves, Andréa F.; Lima, Aline F.; Martinez, Paula F.; Okoshi, Marina P.; Okoshi, Katashi; Paiva, Sergio A. R.; Zornoff, Leonardo A. M., E-mail: lzornoff@fmb.unesp.br [Faculdade de Medicina de Botucatu - Universidade Estadual Paulista ' Júlio de mesquita Filho' - UNESP Botucatu, SP (Brazil)

    2016-02-15

    Heart failure prediction after acute myocardial infarction may have important clinical implications. To analyze the functional echocardiographic variables associated with heart failure in an infarction model in rats. The animals were divided into two groups: control and infarction. Subsequently, the infarcted animals were divided into groups: with and without heart failure. The predictive values were assessed by logistic regression. The cutoff values predictive of heart failure were determined using ROC curves. Six months after surgery, 88 infarcted animals and 43 control animals were included in the study. Myocardial infarction increased left cavity diameters and the mass and wall thickness of the left ventricle. Additionally, myocardial infarction resulted in systolic and diastolic dysfunction, characterized by lower area variation fraction values, posterior wall shortening velocity, E-wave deceleration time, associated with higher values of E / A ratio and isovolumic relaxation time adjusted by heart rate. Among the infarcted animals, 54 (61%) developed heart failure. Rats with heart failure have higher left cavity mass index and diameter, associated with worsening of functional variables. The area variation fraction, the E/A ratio, E-wave deceleration time and isovolumic relaxation time adjusted by heart rate were functional variables predictors of heart failure. The cutoff values of functional variables associated with heart failure were: area variation fraction < 31.18%; E / A > 3.077; E-wave deceleration time < 42.11 and isovolumic relaxation time adjusted by heart rate < 69.08. In rats followed for 6 months after myocardial infarction, the area variation fraction, E/A ratio, E-wave deceleration time and isovolumic relaxation time adjusted by heart rate are predictors of heart failure onset.

  14. Association between Functional Variables and Heart Failure after Myocardial Infarction in Rats

    International Nuclear Information System (INIS)

    Polegato, Bertha F.; Minicucci, Marcos F.; Azevedo, Paula S.; Gonçalves, Andréa F.; Lima, Aline F.; Martinez, Paula F.; Okoshi, Marina P.; Okoshi, Katashi; Paiva, Sergio A. R.; Zornoff, Leonardo A. M.

    2016-01-01

    Heart failure prediction after acute myocardial infarction may have important clinical implications. To analyze the functional echocardiographic variables associated with heart failure in an infarction model in rats. The animals were divided into two groups: control and infarction. Subsequently, the infarcted animals were divided into groups: with and without heart failure. The predictive values were assessed by logistic regression. The cutoff values predictive of heart failure were determined using ROC curves. Six months after surgery, 88 infarcted animals and 43 control animals were included in the study. Myocardial infarction increased left cavity diameters and the mass and wall thickness of the left ventricle. Additionally, myocardial infarction resulted in systolic and diastolic dysfunction, characterized by lower area variation fraction values, posterior wall shortening velocity, E-wave deceleration time, associated with higher values of E / A ratio and isovolumic relaxation time adjusted by heart rate. Among the infarcted animals, 54 (61%) developed heart failure. Rats with heart failure have higher left cavity mass index and diameter, associated with worsening of functional variables. The area variation fraction, the E/A ratio, E-wave deceleration time and isovolumic relaxation time adjusted by heart rate were functional variables predictors of heart failure. The cutoff values of functional variables associated with heart failure were: area variation fraction < 31.18%; E / A > 3.077; E-wave deceleration time < 42.11 and isovolumic relaxation time adjusted by heart rate < 69.08. In rats followed for 6 months after myocardial infarction, the area variation fraction, E/A ratio, E-wave deceleration time and isovolumic relaxation time adjusted by heart rate are predictors of heart failure onset

  15. The conservatism of the net-section stress procedure for predicting the failure of cracked piping systems: The effect of crack location on the degree of conservatism

    International Nuclear Information System (INIS)

    Smith, E.

    1993-01-01

    Interest in the integrity of cracked piping systems fabricated from ductile materials has been motivated, in large part, by the technological problem of intergranular stress corrosion cracking of Type 304 stainless steel piping in boiling water nuclear reactor piping systems. The failure of cracked steel piping is often predicted by assuming that failure conforms to a net-section stress criterion using as input an appropriate value for the critical net-section stress together with a knowledge of the anticipated loadings. The stresses at the cracked section are usually calculated via a purely elastic analysis based on the piping being uncracked. However because the piping is built-in at the ends into a larger component, and since the onset of crack extension requires some plastic deformation, use of the net-section stress approach can give overly conservative failure predictions. An earlier paper has quantified the extent of this conservatism, and has shown how it depends on the material ductility and the elastic flexibility of a piping system. Using the results of analyses for simple model systems, the present paper shows that, for the same cracked section geometry, the degree of conservatism is markedly influenced by the location of the cracked section within the system

  16. High-Temperature Graphitization Failure of Primary Superheater Tube

    Science.gov (United States)

    Ghosh, D.; Ray, S.; Roy, H.; Mandal, N.; Shukla, A. K.

    2015-12-01

    Failure of boiler tubes is the main cause of unit outages of the plant, which further affects the reliability, availability and safety of the unit. So failure analysis of boiler tubes is absolutely essential to predict the root cause of the failure and the steps are taken for future remedial action to prevent the failure in near future. This paper investigates the probable cause/causes of failure of the primary superheater tube in a thermal power plant boiler. Visual inspection, dimensional measurement, chemical analysis, metallographic examination and hardness measurement are conducted as the part of the investigative studies. Apart from these tests, mechanical testing and fractographic analysis are also conducted as supplements. Finally, it is concluded that the superheater tube is failed due to graphitization for prolonged exposure of the tube at higher temperature.

  17. Living Donor Liver Transplantation for Acute Liver Failure : Comparing Guidelines on the Prediction of Liver Transplantation.

    Science.gov (United States)

    Yoshida, Kazuhiro; Umeda, Yuzo; Takaki, Akinobu; Nagasaka, Takeshi; Yoshida, Ryuichi; Nobuoka, Daisuke; Kuise, Takashi; Takagi, Kosei; Yasunaka, Tetsuya; Okada, Hiroyuki; Yagi, Takahito; Fujiwara, Toshiyoshi

    2017-10-01

    Determining the indications for and timing of liver transplantation (LT) for acute liver failure (ALF) is essential. The King's College Hospital (KCH) guidelines and Japanese guidelines are used to predict the need for LT and the outcomes in ALF. These guidelines' accuracy when applied to ALF in different regional and etiological backgrounds may differ. Here we compared the accuracy of new (2010) Japanese guidelines that use a simple scoring system with the 1996 Japanese guidelines and the KCH criteria for living donor liver transplantation (LDLT). We retrospectively analyzed 24 adult ALF patients (18 acute type, 6 sub-acute type) who underwent LDLT in 1998-2009 at our institution. We assessed the accuracies of the 3 guidelines' criteria for ALF. The overall 1-year survival rate was 87.5%. The new and previous Japanese guidelines were superior to the KCH criteria for accurately predicting LT for acute-type ALF (72% vs. 17%). The new Japanese guidelines could identify 13 acute-type ALF patients for LT, based on the timing of encephalopathy onset. Using the previous Japanese guidelines, although the same 13 acute-type ALF patients (72%) had indications for LT, only 4 patients were indicated at the 1st step, and it took an additional 5 days to decide the indication at the 2nd step in the other 9 cases. Our findings showed that the new Japanese guidelines can predict the indications for LT and provide a reliable alternative to the previous Japanese and KCH guidelines.

  18. [Predictive values of different critical scoring systems for mortality in patients with severe acute respiratory failure supported by extracorporeal membrane oxygenation].

    Science.gov (United States)

    Wang, R; Sun, B; Li, X Y; He, H Y; Tang, X; Zhan, Q Y; Tong, Z H

    2016-09-01

    To investigate the predictive values of different critical scoring systems for mortality in patients with severe acute respiratory failure (ARF) supported by venovenous extracorporeal membrane oxygenation (VV-ECMO). Forty-two patients with severe ARF supported by VV-ECMO were enrolled from November 2009 to July 2015.There were 25 males and 17 females. The mean age was (44±18) years (rang 18-69 years). Acute Physiology and Chronic Health Evaluation (APACHE) Ⅱ, Ⅲ, Ⅳ, Simplified Acute Physiology Score Ⅱ (SAPS) Ⅱ, Sequential Organ Failure Assessment (SOFA), ECMO net, PRedicting dEath for SEvere ARDS on VVECMO (PRESERVE), and Respiratory ECMO Survival Prediction (RESP) scores were collected within 6 hours before VV-ECMO support. The patients were divided into the survivors group (n=17) and the nonsurvivors group (n=25) by survival at 180 d after receiving VV-ECMO. The patient clinical characteristics and aforementioned scoring systems were compared between groups. Scoring systems for predicting prognosis were assessed using the area under the receiver-operating characteristic (ROC) curve. The Kaplan-Meier method was used to draw the surviving curve, and the survival of the patients was analyzed by the Log-rank test. The risk factors were assessed for prognosis by multiple logistic regression analysis. (1) Positive end expiratory pressure (PEEP) 6 hours prior to VV-ECMO support in the survivors group [(9.7±5.0)cmH2O, (1 cmH2O=0.098 kPa)] was lower than that in the nonsurvivors group [(13.2±5.4)cmH2O, t=-2.134, P=0.039]. VV-ECMO combination with continuous renal replacement therapy(CRRT) in the nonsurvivors group (32%) was used more than in the survivors group (6%, χ(2)=4.100, P=0.043). Duration of VV-ECMO support in the nonsurvivors group [(15±13) d] was longer than that in the survivors group [(12±11)d, t=-2.123, P=0.041]. APACHE Ⅱ, APACHE Ⅲ, APACHE Ⅳ, ECMO net, PRESERVE, and RESP scores in the survivors group were superior to the nonsurvivors

  19. TBCs for Gas Turbines under Thermomechanical Loadings: Failure Behaviour and Life Prediction

    Directory of Open Access Journals (Sweden)

    Herzog R.

    2012-10-01

    Full Text Available The present contribution gives an overview about recent research on a thermal barrier coating (TBC system consisted of (i an intermetallic MCrAlY-alloy Bondcoat (BC applied by vacuum plasma spraying (VPS and (ii an Yttria Stabilised Zirconia (YSZ top coat air plasma sprayed (APS at Forschungszentrum Juelich, Institute of Energy and Climate Research (IEK-1. The influence of high temperature dwell time, maximum and minimum temperature on crack growth kinetics during thermal cycling of such plasma sprayed TBCs is investigated using infrared pulse thermography (IT, acoustic emission (AE analysis and scanning electron microscopy. Thermocyclic life in terms of accumulated time at maximum temperature decreases with increasing high temperature dwell time and increases with increasing minimum temperature. AE analysis proves that crack growth mainly occurs during cooling at temperatures below the ductile-to-brittle transition temperature of the BC. Superimposed mechanical load cycles accelerate delamination crack growth and, in case of sufficiently high mechanical loadings, result in premature fatigue failure of the substrate. A life prediction model based on TGO growth kinetics and a fracture mechanics approach has been developed which accounts for the influence of maximum and minimum temperature as well as of high temperature dwell time with good accuracy in an extremely wide parameter range.

  20. Fear of failure and self-handicapping in college physical education.

    Science.gov (United States)

    Chen, Lung Hung; Chen, Mei-Yen; Lin, Meng-Shyan; Kee, Ying Hwa; Shui, Shang-Hsueh

    2009-12-01

    The purpose of this study was to examine the relationship between fear of failure and self-handicapping within the context of physical education. Participants were 103 college freshmen enrolled in aerobic dance physical education classes in Taiwan. They completed the Performance Failure Appraisal Inventory and Self-Handicapping Scale for Sport 3 mo. after entering the class. Hierarchical regression indicated that scores on fear of failure predicted self-handicapping scores.

  1. Structural failure analysis of reactor vessels due to molten core debris

    International Nuclear Information System (INIS)

    Pfeiffer, P.A.

    1993-01-01

    Maintaining structural integrity of the reactor vessel during a postulated core melt accident is an important safety consideration in the design of the vessel. This paper addresses the failure predictions of the vessel due to thermal and pressure loadings from the molten core debris depositing on the lower head of the vessel. Different loading combinations were considered based on a wet or dry cavity and pressurization of the vessel based on operating pressure or atmospheric (pipe break). The analyses considered both short term (minutes) and long term (days) failure modes. Short term failure modes include creep at elevated temperatures and plastic instabilities of the structure. Long term failure modes are caused by creep rupture that lead to plastic instability of the structure. The analyses predict the reactor vessel will remain intact after the core melt has deposited on the lower vessel head

  2. Macrophage activation markers predict mortality in patients with liver cirrhosis without or with acute-on-chronic liver failure (ACLF)

    DEFF Research Database (Denmark)

    Grønbæk, Henning; Rødgaard-Hansen, Sidsel; Aagaard, Niels Kristian

    2016-01-01

    BACKGROUND & AIMS: Activation of liver macrophages plays a key role in liver and systemic inflammation and may be involved in development and prognosis of acute-on-chronic liver failure (ACLF). We therefore measured the circulating macrophage activation markers soluble sCD163 and mannose receptor......-C ACLF and CLIF-C AD scores. Addition of the macrophage markers to the clinical scores improved the prognostic efficacy: In ACLF patients sCD163 improved prediction of short-term mortality (C-index: 0.74 (0.67-0.80)) and in patients without ACLF sMR improved prediction of long-term mortality (C-index: 0.......80 (0.76-0.85)). CONCLUSIONS: The severity related increase in sCD163 and sMR and close association with mortality suggest a primary importance of inflammatory activation of liver macrophages in the emergence and course of ACLF. Accordingly, supplementation of the macrophage biomarkers to the platform...

  3. Failure Rate Prediction of Active Component Using PM Basis Database

    International Nuclear Information System (INIS)

    Kim, J. S.; Kim, H. W.; Park, J. S.; Jung, S. G.

    2011-01-01

    The safety security and efficient management of NPPs (Nuclear Power Plants) have been increased after the accident of TEPCO's Fukushima nuclear power stations. The needs for the safety and efficiency are becoming more important because about 90 percent of the NPPs all over the world are more than 20 operation years old. The preventive maintenance criteria need to be flexible, considering long-term development of the equipment performance and preventive maintenance. The PMBD (Preventive Maintenance Basis Database) program was widely used for optimization of the preventive maintenance criteria. PMBD program contains all kinds of failure mechanisms for each equipment that may occur in the power plant based on RCM(Reliability-Centered Maintenance) and numerically calculate the variation of reliability and failure rate based on PM interval changes. In this study, propriety evaluation of preventive maintenance task, cycle, technical basis for cost effective preventive maintenance strategy and an appropriate evaluation were suggested by the case application of PMBD for major components in the NPPs

  4. NRC concerns about steam generator tube U-bend failures

    International Nuclear Information System (INIS)

    Dillon, R.L.

    1981-01-01

    This paper concerns itself with genralized NRC regulatory policy regarding SGT failures and staff reports and opinions which may tend to influence the developing policy specific to U-bend failures. The most significant analysis at hand in predicting NRC policy on SGT U-bend failures is Marsh's Evaluation of Steam Generator Tube Rupture Events. Marsh sets out to describe and analyze the five steam generator tube ruptures that are known to NRC. All have occurred in the period 1975 to 1980

  5. Corrosion induced failure analysis of subsea pipelines

    International Nuclear Information System (INIS)

    Yang, Yongsheng; Khan, Faisal; Thodi, Premkumar; Abbassi, Rouzbeh

    2017-01-01

    Pipeline corrosion is one of the main causes of subsea pipeline failure. It is necessary to monitor and analyze pipeline condition to effectively predict likely failure. This paper presents an approach to analyze the observed abnormal events to assess the condition of subsea pipelines. First, it focuses on establishing a systematic corrosion failure model by Bow-Tie (BT) analysis, and subsequently the BT model is mapped into a Bayesian Network (BN) model. The BN model facilitates the modelling of interdependency of identified corrosion causes, as well as the updating of failure probabilities depending on the arrival of new information. Furthermore, an Object-Oriented Bayesian Network (OOBN) has been developed to better structure the network and to provide an efficient updating algorithm. Based on this OOBN model, probability updating and probability adaptation are performed at regular intervals to estimate the failure probabilities due to corrosion and potential consequences. This results in an interval-based condition assessment of subsea pipeline subjected to corrosion. The estimated failure probabilities would help prioritize action to prevent and control failures. Practical application of the developed model is demonstrated using a case study. - Highlights: • A Bow-Tie (BT) based corrosion failure model linking causation with the potential losses. • A novel Object-Oriented Bayesian Network (OOBN) based corrosion failure risk model. • Probability of failure updating and adaptation with respect to time using OOBN model. • Application of the proposed model to develop and test strategies to minimize failure risk.

  6. Progressive Damage and Failure Analysis of Composite Laminates

    Science.gov (United States)

    Joseph, Ashith P. K.

    Composite materials are widely used in various industries for making structural parts due to higher strength to weight ratio, better fatigue life, corrosion resistance and material property tailorability. To fully exploit the capability of composites, it is required to know the load carrying capacity of the parts made of them. Unlike metals, composites are orthotropic in nature and fails in a complex manner under various loading conditions which makes it a hard problem to analyze. Lack of reliable and efficient failure analysis tools for composites have led industries to rely more on coupon and component level testing to estimate the design space. Due to the complex failure mechanisms, composite materials require a very large number of coupon level tests to fully characterize the behavior. This makes the entire testing process very time consuming and costly. The alternative is to use virtual testing tools which can predict the complex failure mechanisms accurately. This reduces the cost only to it's associated computational expenses making significant savings. Some of the most desired features in a virtual testing tool are - (1) Accurate representation of failure mechanism: Failure progression predicted by the virtual tool must be same as those observed in experiments. A tool has to be assessed based on the mechanisms it can capture. (2) Computational efficiency: The greatest advantages of a virtual tools are the savings in time and money and hence computational efficiency is one of the most needed features. (3) Applicability to a wide range of problems: Structural parts are subjected to a variety of loading conditions including static, dynamic and fatigue conditions. A good virtual testing tool should be able to make good predictions for all these different loading conditions. The aim of this PhD thesis is to develop a computational tool which can model the progressive failure of composite laminates under different quasi-static loading conditions. The analysis

  7. The influence of temperature on low cycle fatigue behavior of prior cold worked 316L stainless steel (II) : life prediction and failure mechanism

    International Nuclear Information System (INIS)

    Hong, Seong Gu; Yoon, Sam Son; Lee, Soon Bok

    2003-01-01

    Tensile and low cycle fatigue tests on prior cold worked 316L stainless steel were carried out at various temperatures from room temperature to 650 deg. C. Fatigue resistance was decreased with increasing temperature and decreasing strain rate. Cyclic plastic deformation, creep, oxidation and interactions with each other are thought to be responsible for the reduction in fatigue resistance. Currently favored life prediction models were examined and it was found that it is important to select a proper life prediction parameter since stress-strain relation strongly depends on temperature. A phenomenological life prediction model was proposed to account for the influence of temperature on fatigue life and assessed by comparing with experimental result. LCF failure mechanism was investigated by observing fracture surfaces of LCF failed specimens with SEM

  8. Failure analysis of parameter-induced simulation crashes in climate models

    Science.gov (United States)

    Lucas, D. D.; Klein, R.; Tannahill, J.; Ivanova, D.; Brandon, S.; Domyancic, D.; Zhang, Y.

    2013-08-01

    Simulations using IPCC (Intergovernmental Panel on Climate Change)-class climate models are subject to fail or crash for a variety of reasons. Quantitative analysis of the failures can yield useful insights to better understand and improve the models. During the course of uncertainty quantification (UQ) ensemble simulations to assess the effects of ocean model parameter uncertainties on climate simulations, we experienced a series of simulation crashes within the Parallel Ocean Program (POP2) component of the Community Climate System Model (CCSM4). About 8.5% of our CCSM4 simulations failed for numerical reasons at combinations of POP2 parameter values. We applied support vector machine (SVM) classification from machine learning to quantify and predict the probability of failure as a function of the values of 18 POP2 parameters. A committee of SVM classifiers readily predicted model failures in an independent validation ensemble, as assessed by the area under the receiver operating characteristic (ROC) curve metric (AUC > 0.96). The causes of the simulation failures were determined through a global sensitivity analysis. Combinations of 8 parameters related to ocean mixing and viscosity from three different POP2 parameterizations were the major sources of the failures. This information can be used to improve POP2 and CCSM4 by incorporating correlations across the relevant parameters. Our method can also be used to quantify, predict, and understand simulation crashes in other complex geoscientific models.

  9. Failure characteristics analysis and fault diagnosis for liquid rocket engines

    CERN Document Server

    Zhang, Wei

    2016-01-01

    This book concentrates on the subject of health monitoring technology of Liquid Rocket Engine (LRE), including its failure analysis, fault diagnosis and fault prediction. Since no similar issue has been published, the failure pattern and mechanism analysis of the LRE from the system stage are of particular interest to the readers. Furthermore, application cases used to validate the efficacy of the fault diagnosis and prediction methods of the LRE are different from the others. The readers can learn the system stage modeling, analyzing and testing methods of the LRE system as well as corresponding fault diagnosis and prediction methods. This book will benefit researchers and students who are pursuing aerospace technology, fault detection, diagnostics and corresponding applications.

  10. Continuum Damage Mechanics Models for the Analysis of Progressive Failure in Open-Hole Tension Laminates

    Science.gov (United States)

    Song, Kyonchan; Li, Yingyong; Rose, Cheryl A.

    2011-01-01

    The performance of a state-of-the-art continuum damage mechanics model for interlaminar damage, coupled with a cohesive zone model for delamination is examined for failure prediction of quasi-isotropic open-hole tension laminates. Limitations of continuum representations of intra-ply damage and the effect of mesh orientation on the analysis predictions are discussed. It is shown that accurate prediction of matrix crack paths and stress redistribution after cracking requires a mesh aligned with the fiber orientation. Based on these results, an aligned mesh is proposed for analysis of the open-hole tension specimens consisting of different meshes within the individual plies, such that the element edges are aligned with the ply fiber direction. The modeling approach is assessed by comparison of analysis predictions to experimental data for specimen configurations in which failure is dominated by complex interactions between matrix cracks and delaminations. It is shown that the different failure mechanisms observed in the tests are well predicted. In addition, the modeling approach is demonstrated to predict proper trends in the effect of scaling on strength and failure mechanisms of quasi-isotropic open-hole tension laminates.

  11. Reliability model for common mode failures in redundant safety systems

    International Nuclear Information System (INIS)

    Fleming, K.N.

    1974-12-01

    A method is presented for computing the reliability of redundant safety systems, considering both independent and common mode type failures. The model developed for the computation is a simple extension of classical reliability theory. The feasibility of the method is demonstrated with the use of an example. The probability of failure of a typical diesel-generator emergency power system is computed based on data obtained from U. S. diesel-generator operating experience. The results are compared with reliability predictions based on the assumption that all failures are independent. The comparison shows a significant increase in the probability of redundant system failure, when common failure modes are considered. (U.S.)

  12. Prediction of the ischemic origin of functional mitral regurgitation in patients with systolic heart failure through posterior mitral leaflet angle

    Directory of Open Access Journals (Sweden)

    Fereshteh Ghaderi

    2018-01-01

    Full Text Available BACKGROUND: Differentiating ischemic from non-ischemic functional mitral regurgitation‎ (FMR in patients with cardiomyopathy is important in terms of the therapeutic decision-making and prognosis, but might be clinically challenging. In this study, the deformation of mitral valve (MV indices in the prediction of the etiology of FMR was assessed using 2D transthoracic and tissue Doppler echocardiography.METHODS: This case-control study was conducted from April 2015 to January 2016 in Imam Reza Hospital in Mashhad, Iran. The participants consisted of 40 patients with ischemic cardiomyopathy (ICM and 22 with non-ischemic dilated cardiomyopathy (DCM who referred to the heart failure clinic. Transthoracic echocardiography was performed using the conventional 2D and tissue Doppler imaging (TDI. MV tenting area (TA, coaptation distance (CD, anterior and posterior mitral leaflet angles (AMLA and PMLA, and regional systolic myocardial velocity (Sm were measured.RESULTS: There were no significant differences in echocardiographic indices between the two groups, besides Sm and PMLA which were significantly lower and higher, respectively, in ICM subjects in comparison with DCM patients (P = 0.002. PMLA ≥ 40 degrees and Sm ≤ 4 cm/second have a relatively high value for discriminating the ischemic from non-ischemic origin of functional MR in subjects with systolic heart failure (sensitivity: 80.0% and 70.0%, specificity: 73.0% and 77.3%; P = 0.001 and P < 0.001; respectively. Multivariable logistic regression identified PMLA and anterior Sm as major determinants for ischemic MR {Odds ratio (OR [95% confidence interval (CI] = 0.89 (0.82-0.96, P = 0.003, OR (95% CI = 0.29 (0.14-0.60, P = 0.001, respectively}.CONCLUSION: The present study showed that PMLA and Sm had an independent significant association with the mechanism of FMR. These findings are suggestive of the predictive role of mitral deformation echocardiographic indices in the determination of the

  13. Failure to thrive: an update.

    Science.gov (United States)

    Cole, Sarah Z; Lanham, Jason S

    2011-04-01

    Failure to thrive in childhood is a state of undernutrition due to inadequate caloric intake, inadequate caloric absorption, or excessive caloric expenditure. In the United States, it is seen in 5 to 10 percent of children in primary care settings. Although failure to thrive is often defined as a weight for age that falls below the 5th percentile on multiple occasions or weight deceleration that crosses two major percentile lines on a growth chart, use of any single indicator has a low positive predictive value. Most cases of failure to thrive involve inadequate caloric intake caused by behavioral or psychosocial issues. The most important part of the outpatient evaluation is obtaining an accurate account of a child's eating habits and caloric intake. Routine laboratory testing rarely identifies a cause and is not generally recommended. Reasons to hospitalize a child for further evaluation include failure of outpatient management, suspicion of abuse or neglect, or severe psychosocial impairment of the caregiver. A multidisciplinary approach to treatment, including home nursing visits and nutritional counseling, has been shown to improve weight gain, parent-child relationships, and cognitive development. The long-term effects of failure to thrive on cognitive development and future academic performance are unclear.

  14. Applicability of out-of-pile fretting wear tests to in-reactor fretting wear-induced failure time prediction

    Science.gov (United States)

    Kim, Kyu-Tae

    2013-02-01

    In order to investigate whether or not the grid-to-rod fretting wear-induced fuel failure will occur for newly developed spacer grid spring designs for the fuel lifetime, out-of-pile fretting wear tests with one or two fuel assemblies are to be performed. In this study, the out-of-pile fretting wear tests were performed in order to compare the potential for wear-induced fuel failure in two newly-developed, Korean PWR spacer grid designs. Lasting 20 days, the tests simulated maximum grid-to-rod gap conditions and the worst flow induced vibration effects that might take place over the fuel life time. The fuel rod perforation times calculated from the out-of-pile tests are greater than 1933 days for 2 μm oxidized fuel rods with a 100 μm grid-to-rod gap, whereas those estimated from in-reactor fretting wear failure database may be about in the range of between 60 and 100 days. This large discrepancy in fuel rod perforation may occur due to irradiation-induced cladding oxide microstructure changes on the one hand and a temperature gradient-induced hydrogen content profile across the cladding metal region on the other hand, which may accelerate brittleness in the grid-contacting cladding oxide and metal regions during the reactor operation. A three-phase grid-to-rod fretting wear model is proposed to simulate in-reactor fretting wear progress into the cladding, considering the microstructure changes of the cladding oxide and the hydrogen content profile across the cladding metal region combined with the temperature gradient. The out-of-pile tests cannot be directly applicable to the prediction of in-reactor fretting wear-induced cladding perforations but they can be used only for evaluating a relative wear resistance of one grid design against the other grid design.

  15. Internal Progressive Failure in Deep-Seated Landslides

    Science.gov (United States)

    Yerro, Alba; Pinyol, Núria M.; Alonso, Eduardo E.

    2016-06-01

    Except for simple sliding motions, the stability of a slope does not depend only on the resistance of the basal failure surface. It is affected by the internal distortion of the moving mass, which plays an important role on the stability and post-failure behaviour of a landslide. The paper examines the stability conditions and the post-failure behaviour of a compound landslide whose geometry is inspired by one of the representative cross-sections of Vajont landslide. The brittleness of the mobilized rock mass was described by a strain-softening Mohr-Coulomb model, whose parameters were derived from previous contributions. The analysis was performed by means of a MPM computer code, which is capable of modelling the whole instability procedure in a unified calculation. The gravity action has been applied to initialize the stress state. This step mobilizes part of the strength along a shearing band located just above the kink of the basal surface, leading to the formation a kinematically admissible mechanism. The overall instability is triggered by an increase of water level. The increase of pore water pressures reduces the effective stresses within the slope and it leads to a progressive failure mechanism developing along an internal shearing band which controls the stability of the compound slope. The effect of the basal shearing resistance has been analysed during the post-failure stage. If no shearing strength is considered (as predicted by a thermal pressurization analysis), the model predicts a response similar to actual observations, namely a maximum sliding velocity of 25 m/s and a run-out close to 500 m.

  16. Confident failures: Lapses of working memory reveal a metacognitive blind spot.

    Science.gov (United States)

    Adam, Kirsten C S; Vogel, Edward K

    2017-07-01

    Working memory performance fluctuates dramatically from trial to trial. On many trials, performance is no better than chance. Here, we assessed participants' awareness of working memory failures. We used a whole-report visual working memory task to quantify both trial-by-trial performance and trial-by-trial subjective ratings of inattention to the task. In Experiment 1 (N = 41), participants were probed for task-unrelated thoughts immediately following 20% of trials. In Experiment 2 (N = 30), participants gave a rating of their attentional state following 25% of trials. Finally, in Experiments 3a (N = 44) and 3b (N = 34), participants reported confidence of every response using a simple mouse-click judgment. Attention-state ratings and off-task thoughts predicted the number of items correctly identified on each trial, replicating previous findings that subjective measures of attention state predict working memory performance. However, participants correctly identified failures on only around 28% of failure trials. Across experiments, participants' metacognitive judgments reliably predicted variation in working memory performance but consistently and severely underestimated the extent of failures. Further, individual differences in metacognitive accuracy correlated with overall working memory performance, suggesting that metacognitive monitoring may be key to working memory success.

  17. Diagnosis of Nonischemic Stage B Heart Failure in Type 2 Diabetes Mellitus: Optimal Parameters for Prediction of Heart Failure.

    Science.gov (United States)

    Wang, Ying; Yang, Hong; Huynh, Quan; Nolan, Mark; Negishi, Kazuaki; Marwick, Thomas H

    2018-05-11

    This study sought to identify whether impaired global longitudinal strain (GLS), diastolic dysfunction (DD), or left atrial enlargement (LAE) should be added to stage B heart failure (SBHF) criteria in asymptomatic patients with type 2 diabetes mellitus. SBHF is a precursor to clinical heart failure (HF), and its recognition justifies initiation of cardioprotective therapy. However, original definitions of SBHF were based on LV hypertrophy and impaired ejection fraction. Patients with asymptomatic type 2 diabetes mellitus ≥65 years-of-age (age 71 ± 4 years; 55% men) with preserved ejection fraction and no ischemic heart disease were recruited from a community-based population. All underwent a standard clinical evaluation, and a comprehensive echocardiogram, including assessment of left ventricular hypertrophy (LVH), LAE, DD (abnormal E/e'), and GLS (<16%). Over a median follow-up of 1.5 years (range 0.5 to 3), 20 patients were lost to follow-up, and 290 individuals were entered into the final analyses. In this asymptomatic group, LV dysfunction was identified in 30 (10%) by DD, 68 (23%) by LVH, 102 (35%) by LAE, and 68 (23%) by impaired GLS. New-onset HF developed in 45 patients and 4 died, giving an event rate of 112/1,000 person-years. Survival free of the composite endpoint (HF and death) was about 1.5-fold higher in patients without a normal, compared with an abnormal echocardiogram. LVH, LAE, and GLS <16% were associated with increased risk of the composite endpoint, independent of ARIC risk score and glycosylated hemoglobin, but abnormal E/e' was not. The addition of left atrial volume and GLS provided incremental value to the current standard of clinical risk (ARIC score) and LVH. In a competing-risks regression analysis, LVH (hazard ratio: 2.90; p < 0.001) and GLS <16% (hazard ratio: 2.26; p = 0.008), but not DD and LAE were associated with incident HF. Subclinical left ventricular systolic dysfunction is prevalent in asymptomatic elderly patients

  18. PREDICE score as a predictor of 90 days mortality in patients with heart failure

    Science.gov (United States)

    Purba, D. P. S.; Hasan, R.

    2018-03-01

    Hospitalization in chronic heart failure patients associated with high mortality and morbidity rate. The 90 days post-discharge period following hospitalization in heart failure patients is known as the vulnerable phase, it carries the high risk of poor outcomes. Identification of high-risk individuals by using prognostic evaluation was intended to do a closer follow up and more intensive to decreasing the morbidity and mortality rate of heart failure.To determine whether PREDICE score could predict mortality within 90 days in patients with heart failure, an observational cohort study in patients with heart failure who were hospitalized due to worsening chronic heart failure. Patients were in following-up for up to 90 days after initial evaluation with the primary endpoint is death.We found a difference of the significantstatistical between PREDICE score in survival and mortality group (p=0.001) of 84% (95% CI: 60.9% - 97.4%).In conclusion, PREDICE score has a good ability to predict mortality within 90 days in patients with heart failure.

  19. PREDICTION AND PREVENTION OF LIVER FAILURE AFTER MAJOR LIVER PRIMARY AND METASTATIC TUMORS RESECTION

    Directory of Open Access Journals (Sweden)

    A. D. Kaprin

    2016-01-01

    Full Text Available Abstract Purpose of the study. Improvement of results of treatment in patients with primary and metastatic liver cancer by decreasing the risk of post-resection liver failure on the basis of the evaluation of the functional reserves of the liver.Materials and Methods. The study included two independent samples of patients operated about primary or metastatic lesions of the liver at the Department of abdominal Oncology, P. A. Hertsen MORI. The first group included 53 patients who carried out 13C-breath test metallimovie and dynamic scintigraphy of the liver in the preoperative stage in addition to the standard algorithm of examination. Patients of the 2nd group (n=35 had a standard clinical and laboratory examination, the patients were not performed the preoperative evaluation of the functional reserve of the liver, the incidences of total bilirubin, albumin and prothrombin time did not reveal a reduction of liver function. Post-resection liver failure have been established on the basis of the 50/50 criterion in the evaluation on day 5 after surgery.Results. Analysis of operating characteristics of the functional tests showed the absolute methacin breath test sensitivity (SE≥100%, high specificity (SP≥67% of scintigraphy of the liver and the negative predictive value of outcome (VP≥100% at complex use of two diagnostic methods. The incidence of PROPS in the study group was significantly 2 times higher in the control group –15,1% and 26.8%, respectively (p<0.001.Conclusion. The combination of preoperative dynamic scintigraphy of the liver with carrying out 13C-breath methacin test allows you to conduct a comprehensive evaluation of the liver functional reserve and can significantly improve preoperative evaluation and postoperative results of anatomic resection in patients with primary and metastatic liver lesions.

  20. HEDL empirical correlation of fuel pin top failure thresholds, status 1976

    International Nuclear Information System (INIS)

    Baars, R.E.

    1976-01-01

    The Damage Parameter (DP) empirical correlation of fuel pin cladding failure thresholds for TOP events has been revised and recorrelated to the results of twelve TREAT tests. The revised correlation, called the Failure Potential (FP) correlation, predicts failure times for the tests in the data base with an average error of 35 ms for $3/s tests and of 150 ms for 50 cents/s tests

  1. CorVue algorithm efficacy to predict heart failure in real life: Unnecessary and potentially misleading information?

    Science.gov (United States)

    Palfy, Julia Anna; Benezet-Mazuecos, Juan; Milla, Juan Martinez; Iglesias, Jose Antonio; de la Vieja, Juan Jose; Sanchez-Borque, Pepa; Miracle, Angel; Rubio, Jose Manuel

    2018-06-01

    Heart failure (HF) hospitalizations have a negative impact on quality of life and imply important costs. Intrathoracic impedance (ITI) variations detected by cardiac devices have been hypothesized to predict HF hospitalizations. Although Optivol™ algorithm (Medtronic) has been widely studied, CorVue™ algorithm (St. Jude Medical) long term efficacy has not been systematically evaluated in a "real life" cohort. CorVue™ was activated in ICD/CRT-D patients to store information about ITI measures. Clinical events (new episodes of HF requiring treatment and hospitalizations) and CorVue™ data were recorded every three months. Appropriate CorVue™ detection for HF was considered if it occurred in the four prior weeks to the clinical event. 53 ICD/CRT-D (26 ICD and 27 CRT-D) patients (67±1 years-old, 79% male) were included. Device position was subcutaneous in 28 patients. At inclusion, mean LVEF was 25±7% and 27 patients (51%) were in NYHA class I, 18 (34%) class II and 8 (15%) class III. After a mean follow-up of 17±9 months, 105 ITI drops alarms were detected in 32 patients (60%). Only six alarms were appropriate (true positive) and required hospitalization. Eighteen patients (34%) presented 25 clinical episodes (12 hospitalizations and 13 ER/ambulatory treatment modifications). Nineteen of these clinical episodes (76%) remained undetected by the CorVue™ (false negative). Sensitivity of CorVue™ resulted in 24%, specificity was 70%, positive predictive value of 6% and negative predictive value of 93%. CorVue™ showed a low sensitivity to predict HF events. Therefore, routinely activation of this algorithm could generate misleading information. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  2. Observations on analysis, testing and failure of prestressed concrete containments

    International Nuclear Information System (INIS)

    Murray, D.W.

    1984-01-01

    The paper reviews the mechanics which indicate that a bursting failure with large energy release is the failure mechanism to be expected from ductile lined containment structures pressurized to failure. It reviews a study which shows that, because of leakage, this is not the case for unlined prestressed containments. It argues that current practice, since it does not specifically address the bursting failure problem for lined prestressed containments, is inadequate to ensure that this type of failure could not occur. It concludes that, in view of the inadequacy of the current state-of-the-art to predict leakage from lined structures, the logical remedy is to eliminate all possibility of bursting failure by making provision for venting of containments. (orig.)

  3. Assessment of current structural design methodology for high-temperature reactors based on failure tests

    International Nuclear Information System (INIS)

    Corum, J.M.; Sartory, W.K.

    1985-01-01

    A mature design methodology, consisting of inelastic analysis methods, provided in Department of Energy guidelines, and failure criteria, contained in ASME Code Case N-47, exists in the United States for high-temperature reactor components. The objective of this paper is to assess the adequacy of this overall methodology by comparing predicted inelastic deformations and lifetimes with observed results from structural failure tests and from an actual service failure. Comparisons are presented for three types of structural situations: (1) nozzle-to-spherical shell specimens, where stresses at structural discontinuities lead to cracking, (2) welded structures, where metallurgical discontinuities play a key role in failures, and (3) thermal shock loadings of cylinders and pipes, where thermal discontinuities can lead to failure. The comparison between predicted and measured inelastic responses are generally reasonalbly good; quantities are sometimes overpredicted somewhat, and, sometimes underpredicted. However, even seemingly small discrepancies can have a significant effect on structural life, and lifetimes are not always as closely predicted. For a few cases, the lifetimes are substantially overpredicted, which raises questions regarding the adequacy of existing design margins

  4. Pre- and post-radiotherapy computed tomography in laryngeal cancer: imaging-based prediction of local failure

    International Nuclear Information System (INIS)

    Pameijer, Frank A.; Hermans, Robert; Mancuso, Anthony A.; Mendenhall, William M.; Parsons, James T.; Stringer, Scott P.; Kubilis, Paul S.; Tinteren, Harm van

    1999-01-01

    Purpose: To determine if pre-radiotherapy (RT) and/or post-radiotherapy computed tomography (CT) can predict local failure in patients with laryngeal carcinoma treated with definitive RT. Methods and Materials: The pre- and post-RT CT examinations of 59 patients (T3 glottic carcinoma [n = 30] and T1-T4 supraglottic carcinoma [n = 29]) were reviewed. For each patient, the first post-RT CT study between 1 and 6 months after irradiation was used. All patients were treated with definitive hyperfractionated twice-daily continuous-course irradiation to a total dose of 6,720-7,920 cGy, and followed-up clinically for at least 2 years after completion of RT. Local control was defined as absence of primary tumor recurrence and a functioning larynx. On the pre-treatment CT study, each tumor was assigned a high-or low-risk profile for local failure after RT. The post-RT CT examinations were evaluated for post-treatment changes using a three-point post-RT CT-score: 1 = expected post-RT changes; 2 = focal mass with a maximal diameter of 1 cm, or < 50% estimated tumor volume reduction. Results: The local control rates at 2 years post-RT based on pre-treatment CT evaluation were 88% for low pre-treatment risk profile patients (95% CI: 66-96%) and 34% (95% CI: 19-50%) for high pre-treatment risk profile patients (risk ratio 6.583; 95% CI: 2.265-9.129; p = 0.0001). Based on post-treatment CT, the local control rates at 2 years post-RT were 94% for score 1, 67% for score 2, and 10% for score 3 (risk ratio 4.760; 95% CI: 2.278-9.950 p 0.0001). Post-RT CT scores added significant information to the pre-treatment risk profiles on prognosis. Conclusions: Pre-treatment CT risk profiles, as well as post-RT CT evaluation can identify patients, irradiated for laryngeal carcinomas, at high risk for developing local failure. When the post-RT CT score is available, it proves to be an even better prognosticator than the pre-treatment CT-risk profile

  5. Prediction of thermoplastic failure of a reactor pressure vessel under a postulated core melt accident

    International Nuclear Information System (INIS)

    Duijvestijn, G.; Birchley, J.; Reichlin, K.

    1997-01-01

    This paper presents the lower head failure calculations performed for a postulated accident scenario in a commercial nuclear power plant. A postulated one inch break in the primary coolant circuit leads to dryout and subsequent meltdown of the core. The reference plant is a pressurized water reactor without penetrations in the reactor vessel lower head. The molten core material accumulates in the lower head, eventually causing failure of the vessel. The analysis investigates flow conditions in the melt pool, temperature evolution in the reactor vessel wall, and structure mechanical evaluation of the vessel under strong thermal loads and a range of internal pressures. The calculations were performed using the ADINA finite element codes. The analysis focusses on the failure processes, time and mode of failure. The most likely mode of failure at low pressure is global rupture due to gradual accumulation of creep strain over a large part of the heated area. In contrast, thermoplasticity becomes important at high pressure or following a pressure spike and can lead to earlier local failure. In situations in which part of the heat load is concentrated over a small area, resulting in a hot spot, local failure occurs, but not until the temperatures are close to the melting point. At low pressure, in particular, the hot spot area remains intact until the structure is molten across more than half of the thickness. (author) 14 figs., 16 refs

  6. Haemodialysis for post-traumatic acute renal failure - factors predicting outcome.

    Science.gov (United States)

    Machemehl, Thomas; Hsu, Peter; Pahad, Hussein; Williams, Paul; Yilmaz, Tugba H; Vassiliu, Pantelis; Boffard, Kenneth D; Degiannis, Elias; Doll, Dietrich

    2013-07-29

    Post-traumatic acute renal failure requiring renal replacement therapy in an intensive care unit (ICU) is associated with high mortality. To assess indicators of improved survival. This was a retrospective cohort study of 64 consecutive trauma patients (penetrating and blunt trauma and burns) who underwent haemodialysis (HD) over a period of 5 years. Information on pre-hospital and in-hospital resuscitation, trauma scores and physiological scores and daily ICU records were collected. The majority of the patients were dialysed with continuous venovenous haemofiltration in the early years of the study and later with sustained low-efficiency dialysis. Of the 64 patients 47 died, giving an overall mortality rate of 73%. Mortality was highest in the burns patients (84%). Survival in all patients, irrespective of injury, was unrelated to the Revised Trauma Score, Injury Severity Score, Acute Physiology and Chronic Health Evaluation Score or Trauma Injury Severity Score. The duration of HD did not differ significantly between the three trauma groups, and age was not a significant predictor of survival. Patients who were polyuric at the time of the initiation of HD had a lower mortality rate than those who were oliguric, anuric or normouric, although this did not reach statistical significance (p=0.09). Acute renal failure in trauma patients is associated with a low survival rate. Controversial conclusions have been presented in the literature. In this study, none of the parameters previously reported to affect survival proved to be valid, although the number of patients was comparable with those in other studies. Since understanding of the predictors and course of renal failure in trauma patients is still at an early stage, there is a need for multicentre prospective studies.

  7. Metallized Film Capacitor Lifetime Evaluation and Failure Mode Analysis

    CERN Document Server

    Gallay, R.

    2015-06-15

    One of the main concerns for power electronic engineers regarding capacitors is to predict their remaining lifetime in order to anticipate costly failures or system unavailability. This may be achieved using a Weibull statistical law combined with acceleration factors for the temperature, the voltage, and the humidity. This paper discusses the different capacitor failure modes and their effects and consequences.

  8. Cardiac rehabilitation in patients with ST-segment elevation myocardial infarction: can its failure be predicted?

    Science.gov (United States)

    Irzmański, Robert; Kapusta, Joanna; Obrębska-Stefaniak, Agnieszka; Urzędowicz, Beata; Kowalski, Jan

    2017-07-01

    The prognosis in patients after acute coronary syndromes (ACS) is significantly burdened by coexisting anaemia, leukocytosis and low glomerular filtration rate (GFR). Hyperglycaemia in the early stages of ACS is a strong predictor of death and heart failure in non-diabetic subjects. This study aimed to evaluate the effect of hyperglycaemia, anaemia, leukocytosis, thrombocytopaenia and decreased GFR on the risk of the failure of cardiac rehabilitation (phase II at the hospital) in post-ST-segment elevation myocardial infarction (STEMI) patients. The study included 136 post-STEMI patients, 96 men and 40 women, aged 60.1 ± 11.8 years, admitted for cardiac rehabilitation (phase II) to the Department of Internal Medicine and Cardiac Rehabilitation, WAM University Hospital in Lodz, Poland. On admission fasting blood cell count was performed and serum glucose and creatinine level was determined (GFR assessment). The following results were considered abnormal: glucose ⩾ 100 mg/dl, GFR 10 × 103/μl; platelets (PLTs) failure of cardiac rehabilitation. This risk has been defined on the basis of the patient's inability to tolerate workload increment >5 Watt in spite of the applied program of cardiac rehabilitation. As a result of building a logistic regression model, the most statistically significant risk factors were selected, on the basis of which cardiac rehabilitation failure index was determined. leukocytosis and reduced GFR determined most significantly the risk of failure of cardiac rehabilitation (respectively OR = 6.42 and OR = 3.29, p = 0.007). These parameters were subsequently utilized to construct a rehabilitation failure index. Peripheral blood cell count and GFR are important in assessing the prognosis of cardiac rehabilitation effects. leukocytosis and decreased GFR determine to the highest degree the risk of cardiac rehabilitation failure. Cardiac rehabilitation failure index may be useful in classifying patients into an appropriate model of

  9. A review of stent’s failure on patent ductus arteriosus

    Science.gov (United States)

    Lazim, Zulfaqih; Ismail, Al Emran; Taib, Ishkrizat; Atan, Bainun Akmal Mohd

    2017-01-01

    This paper presents a review of stent’s failure on patent ductus arteriosus (PDA). Ductus arteriosus (DA) is an opening for newborn babies and some patient that experienced cynotic congenital heart disease (CCHD) should maintain the duct opening for survival. To date, there are no specific research on mechanical stent failure study at DA. The challenging of the stent implantation on PDA is the PDA morphology. The failure of stent in term of stent fracture have been reported and reviewed in this paper. Furthermore, the failure prediction of stent is important for further stent design development. The morphology of PDA, stent type and material used in PDA and method for accessing the failure of stent is reviewed.

  10. Looking good, but behaving badly: leader accountability and ethics failure.

    Science.gov (United States)

    Bruhn, John G

    2005-01-01

    Making the bottom line is a fact of life in the business and corporate world. However, when organizations and their leaders become fixated on the bottom line and ignore values, an environment conducive to ethics failure is nurtured. Ethics failure has focused almost exclusively on the behavior of organizational leaders. However, it is the interaction of the culture of organizations and the character of their leaders that create the environment and social situations conducive to ethics failure. Although ethics failure is not totally preventable, there are usually warning signs early in the recruitment process of prospective CEOs that predict ethics failure. The author suggests that specific up-front questions be asked to ascertain the ethical fitness of prospective CEOs.

  11. Biomarker Guided Therapy in Chronic Heart Failure

    Science.gov (United States)

    Bektas, Sema

    2015-01-01

    This review article addresses the question of whether biomarker-guided therapy is ready for clinical implementation in chronic heart failure. The most well-known biomarkers in heart failure are natriuretic peptides, namely B-type natriuretic peptide (BNP) and N-terminal pro-BNP. They are well-established in the diagnostic process of acute heart failure and prediction of disease prognosis. They may also be helpful in screening patients at risk of developing heart failure. Although studied by 11 small- to medium-scale trials resulting in several positive meta-analyses, it is less well-established whether natriuretic peptides are also helpful for guiding chronic heart failure therapy. This uncertainty is expressed by differences in European and American guideline recommendations. In addition to reviewing the evidence surrounding the use of natriuretic peptides to guide chronic heart failure therapy, this article gives an overview of the shortcomings of the trials, how the results may be interpreted and the future directions necessary to fill the current gaps in knowledge. Therapy guidance in chronic heart failure using other biomarkers has not been prospectively tested to date. Emerging biomarkers, such as galectin-3 and soluble ST2, might be useful in this regard, as suggested by several post-hoc analyses. PMID:28785440

  12. Prediction of the Chemoreflex Gain by Common Clinical Variables in Heart Failure.

    Directory of Open Access Journals (Sweden)

    Gianluca Mirizzi

    Full Text Available Peripheral and central chemoreflex sensitivity, assessed by the hypoxic or hypercapnic ventilatory response (HVR and HCVR, respectively, is enhanced in heart failure (HF patients, is involved in the pathophysiology of the disease, and is under investigation as a potential therapeutic target. Chemoreflex sensitivity assessment is however demanding and, therefore, not easily applicable in the clinical setting. We aimed at evaluating whether common clinical variables, broadly obtained by routine clinical and instrumental evaluation, could predict increased HVR and HCVR.191 patients with systolic HF (left ventricular ejection fraction--LVEF--<50% underwent chemoreflex assessment by rebreathing technique to assess HVR and HCVR. All patients underwent clinical and neurohormonal evaluation, comprising: echocardiogram, cardiopulmonary exercise test (CPET, daytime cardiorespiratory monitoring for breathing pattern evaluation. Regarding HVR, multivariate penalized logistic regression, Bayesian Model Averaging (BMA logistic regression and random forest analysis identified, as predictors, the presence of periodic breathing and increased slope of the relation between ventilation and carbon dioxide production (VE/VCO2 during exercise. Again, the above-mentioned statistical tools identified as HCVR predictors plasma levels of N-terminal fragment of proBNP and VE/VCO2 slope.In HF patients, the simple assessment of breathing pattern, alongside with ventilatory efficiency during exercise and natriuretic peptides levels identifies a subset of patients presenting with increased chemoreflex sensitivity to either hypoxia or hypercapnia.

  13. A relation to describe rate-dependent material failure.

    Science.gov (United States)

    Voight, B

    1989-01-13

    The simple relation OmegaOmega-alpha = 0, where Omega is a measurable quantity such as strain and A and alpha are empirical constants, describes the behavior of materials in terminal stages of failure under conditions of approximately constant stress and temperature. Applicable to metals and alloys, ice, concrete, polymers, rock, and soil, the relation may be extended to conditions of variable and multiaxial stress and may be used to predict time to failure.

  14. CPAP by helmet for treatment of acute respiratory failure after pediatric liver transplantation.

    Science.gov (United States)

    Chiusolo, F; Fanelli, V; Ciofi Degli Atti, M L; Conti, G; Tortora, F; Pariante, R; Ravà, L; Grimaldi, C; de Ville de Goyet, J; Picardo, S

    2018-02-01

    ARF after pediatric liver transplantation accounts for high rate of morbidity and mortality associated with this procedure. The role of CPAP in postoperative period is still unknown. The aim of the study was to describe current practice and risk factors associated with the application of helmet CPAP. In this retrospective observational cohort study, 119 recipients were divided into two groups based on indication to CPAP after extubation. Perioperative variables were studied, and determinants of CPAP application were analyzed in a multivariate logistic model. Sixty patients (60/114) developed ARF and were included in the CPAP group. No differences were found between the two groups for primary disease, graft type, and blood product transfused. At multivariate analysis, weight 148 mL/kg (OR = 4.0; 95% CI = 1.6-10.1; P = .004) were the main determinants of CPAP application. In the CPAP group, five patients (8.4%) needed reintubation. Pediatric liver recipients with lower weight, higher need of inotropes/vasopressors, higher positive fluid balance after surgery, and lower PaO 2 /FiO 2 before extubation were at higher odds of developing ARF needing CPAP application. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Bayesian analysis of repairable systems showing a bounded failure intensity

    International Nuclear Information System (INIS)

    Guida, Maurizio; Pulcini, Gianpaolo

    2006-01-01

    The failure pattern of repairable mechanical equipment subject to deterioration phenomena sometimes shows a finite bound for the increasing failure intensity. A non-homogeneous Poisson process with bounded increasing failure intensity is then illustrated and its characteristics are discussed. A Bayesian procedure, based on prior information on model-free quantities, is developed in order to allow technical information on the failure process to be incorporated into the inferential procedure and to improve the inference accuracy. Posterior estimation of the model-free quantities and of other quantities of interest (such as the optimal replacement interval) is provided, as well as prediction on the waiting time to the next failure and on the number of failures in a future time interval is given. Finally, numerical examples are given to illustrate the proposed inferential procedure

  16. A statistical analysis of pellet-clad interaction failures in water reactor fuel

    International Nuclear Information System (INIS)

    McDonald, S.G.; Fardo, R.D.; Sipush, P.J.; Kaiser, R.S.

    1981-01-01

    The primary objective of the statistical analysis was to develop a mathematical function that would predict PCI fuel rod failures as a function of the imposed operating conditions. Linear discriminant analysis of data from both test and commercial reactors was performed. The initial data base used encompassed 713 data points (117 failures and 596 non-failures) representing a wide variety of water cooled reactor fuel (PWR, BWR, CANDU, and SGHWR). When applied on a best-estimate basis, the resulting function simultaneously predicts approximately 80 percent of both the failure and non-failure data correctly. One of the most significant predictions of the analysis is that relatively large changes in power can be tolerated when the pre-ramp irradiation power is low, but that only small changes in power can be tolerated when the pre-ramp irradiation power is high. However, it is also predicted that fuel rods irradiated at low power will fail at lower final powers than those irradiated at high powers. Other results of the analysis are that fuel rods with high clad operating temperatures can withstand larger power increases that fuel rods with low clad operating temperatures, and that burnup has only a minimal effect on PCI performance after levels of approximately 10000 MWD/MTU have been exceeded. These trends in PCI performance and the operating parameters selected are believed to be consistent with mechanistic considerations. Published PCI data indicate that BWR fuel usually operates at higher local powers and changes in power, lower clad temperatures, and higher local ramp rates than PWR fuel

  17. Application of Failure Mode Effect and Criticality Analysis (FMECA to a Computer Integrated Manufacturing (CIM Conveyor Belt

    Directory of Open Access Journals (Sweden)

    I. Elbadawi

    2018-06-01

    Full Text Available Fault finding and failure predicting techniques in manufacturing and production systems often involve forecasting failures, their effects, and occurrences. The majority of these techniques predict failures that may appear during the regular system production time. However, they do not estimate the failure modes and they require extensive source code instrumentation. In this study, we suggest an approach for predicting failure occurrences and modes during system production time intervals at the University of Hail (UoH. The aim of this project is to implement failure mode effect and criticality analysis (FMECA on computer integrated manufacturing (CIM conveyors to determine the effect of various failures on the CIM conveyor belt by ranking and prioritizing each failure according to its risk priority number (RPN. We incorporated the results of FMECA in the development of formal specifications of fail-safe CIM conveyor belt systems. The results show that the highest RPN values are for motor over current failure (450, conveyor chase of vibration (400, belt run off at the head pulley (200, accumulated dirt (180, and Bowed belt (150. The study concludes that performing FMECA is highly effective in improving CIM conveyor belt reliability and safety in the mechanical engineering workshop at UoH.

  18. The prediction of failure of welded steel plates for pressure vessels

    International Nuclear Information System (INIS)

    Gulvin, T.F.; Terry, P.; Webster, S.E.

    1980-01-01

    The avoidance of brittle fracture in pressure vessels and other welded steel fabrications is a matter of considerable importance. The application of fracture mechanics to this problem has led to the evolution of a philosophy which, among other things, permits estimation of tolerable crack sizes so that practical working limits can be set on inspection procedures and on material and welded joint toughness levels. The use of small-scale fracture mechanics tests, particularly crack opening displacement (COD) tests, to make the necessary material and/or joint property assessments is now commonplace. A number of possible analytical techniques have been considered. Initially, the COD data have been used with the Burdekin-Dawes design curve approach taking into account all the possible stress conditions and, it can be demonstrated, that consistently safe predictions of allowable flaw sizes can be made. Also considered, is the fracture analysis diagram approach of Harrison, Loosemore, and Milne in which a combination of fracture toughness data and mechanical property data is used to assess the probability of failure. Similarly the approach defined by Irvine and Quirk which makes use of mechanical property data without resorting to fracture mechanics and finally, a simple approach using uniaxial tensile property data only has also been examined. Comparisons have been made between these four approaches using, initially, the body of data referring to fracture tests on a single material with various defect sizes and aspect ratios, etc. and latterly, to the specific cases in the body of data on high strength steels. The results are discussed. (author)

  19. On the development of life prediction methodologies for the failure of human teeth

    Energy Technology Data Exchange (ETDEWEB)

    Nalla, R.K.; Imbeni, V.; Kinney, J.H.; Marshall, S.J.; Ritchie, R.O.

    2002-09-18

    Human dentin is known to be susceptible to failure under cyclic loading. Surprisingly, there are few reports that quantify the effect of such loading, considering the fact that a typical tooth experiences a million or so loading cycles annually. In the present study, a systematic investigation is described of the effects of prolonged cyclic loading on human dentin in a simulated physiological environment. In vitro stress-life (S/N) data are discussed in the context of possible mechanisms of fatigue damage and failure.

  20. Fuel element failures caused by iodine stress corrosion

    International Nuclear Information System (INIS)

    Videm, K.; Lunde, L.

    1976-01-01

    Sections of unirradiated cladding tubes were plugged in both ends by mechanical seals and internally pressurized with argon containing iodine. The time to failure and the strain at failure as a function of stress was determined for tubing with different heat treatments. Fully annealed tubes suffer cracking at the lowest stress but exhibit the largest strains at failure. Elementary iodine is not necessary for stress corrosion: small amounts of iodides of zirconium, iron and aluminium can also give cracking. Moisture, however, was found to act as an inhibitor. A deformation threshold exists below which stress corrosion failure does not occur regardless of the exposure time. This deformation limit is lower the harder the tube. The deformation at failure is dependent on the deformation rate and has a minimum at 0.1%/hr. At higher deformation rates the failure deformation increases, but only slightly for hard tubes. Fuel was over-power tested at ramp rates varying between 0.26 to 30 W/cm min. For one series of fuel pins the failure deformations of 0.8% at high ramp rates were in good agreement with predictions based on stress corrosion experiments. For another series of experiments the failure deformation was surprisingly low, about 0.2%. (author)

  1. Prediction of the effect of atrasentan on renal and heart failure outcomes based on short-term changes in multiple risk markers

    DEFF Research Database (Denmark)

    Schievink, Bauke; de Zeeuw, Dick; Smink, Paul A

    2016-01-01

    from the RADAR/JAPAN study to predict the effect of atrasentan on renal and heart failure outcomes. METHODS: We performed a post-hoc analysis of the RADAR/JAPAN randomized clinical trials in which 211 patients with type-2 diabetes and nephropathy were randomly assigned to atrasentan 0.75 mg/day, 1......BACKGROUND: A recent phase II clinical trial (Reducing Residual Albuminuria in Subjects with Diabetes and Nephropathy with AtRasentan trial and an identical trial in Japan (RADAR/JAPAN)) showed that the endothelin A receptor antagonist atrasentan lowers albuminuria, blood pressure, cholesterol......, hemoglobin, and increases body weight in patients with type 2 diabetes and nephropathy. We previously developed an algorithm, the Parameter Response Efficacy (PRE) score, which translates short-term drug effects into predictions of long-term effects on clinical outcomes. DESIGN: We used the PRE score on data...

  2. Development of a container failure function for copper

    International Nuclear Information System (INIS)

    King, F.; Litke, C.D.

    1990-01-01

    A simple approach to the modeling of failure rates for a copper container under Canadian waste disposal conditions is presented. Both uniform corrosion and pitting must be considered. Short-term failures due to fabrication defects must be taken into account. The model allows for short-term sorption of copper by the clay buffer material, and assumes a steady-state condition for uniform corrosion. Using worst-case assumptions, a container penetration time of 3300 years can be predicted

  3. An integrated approach to estimate storage reliability with initial failures based on E-Bayesian estimates

    International Nuclear Information System (INIS)

    Zhang, Yongjin; Zhao, Ming; Zhang, Shitao; Wang, Jiamei; Zhang, Yanjun

    2017-01-01

    Storage reliability that measures the ability of products in a dormant state to keep their required functions is studied in this paper. For certain types of products, Storage reliability may not always be 100% at the beginning of storage, unlike the operational reliability, which exist possible initial failures that are normally neglected in the models of storage reliability. In this paper, a new integrated technique, the non-parametric measure based on the E-Bayesian estimates of current failure probabilities is combined with the parametric measure based on the exponential reliability function, is proposed to estimate and predict the storage reliability of products with possible initial failures, where the non-parametric method is used to estimate the number of failed products and the reliability at each testing time, and the parameter method is used to estimate the initial reliability and the failure rate of storage product. The proposed method has taken into consideration that, the reliability test data of storage products containing the unexamined before and during the storage process, is available for providing more accurate estimates of both the initial failure probability and the storage failure probability. When storage reliability prediction that is the main concern in this field should be made, the non-parametric estimates of failure numbers can be used into the parametric models for the failure process in storage. In the case of exponential models, the assessment and prediction method for storage reliability is presented in this paper. Finally, a numerical example is given to illustrate the method. Furthermore, a detailed comparison between the proposed and traditional method, for examining the rationality of assessment and prediction on the storage reliability, is investigated. The results should be useful for planning a storage environment, decision-making concerning the maximum length of storage, and identifying the production quality. - Highlights:

  4. Validation of the Kidney Failure Risk Equation in Manitoba

    Directory of Open Access Journals (Sweden)

    Reid H. Whitlock

    2017-04-01

    Full Text Available Background: Patients with chronic kidney disease (CKD are at risk to progress to kidney failure. We previously developed the Kidney Failure Risk Equation (KFRE to predict progression to kidney failure in patients referred to nephrologists. Objective: The objective of this study was to determine the ability of the KFRE to discriminate which patients will progress to kidney failure in an unreferred population. Design: A retrospective cohort study was conducted using administrative databases. Setting: This study took place in Manitoba, Canada. Measurements: Age, sex, estimated glomerular filtration rate (eGFR, and urine albumin-to-creatinine ratio (ACR were measured. Methods: We included patients from the Diagnostic Services of Manitoba database with an eGFR <60 mL/min/1.73 m 2 and ACR measured between October 2006 and March 2007. Five-year kidney failure risk was predicted using the 4-variable KFRE and compared with treated kidney failure events from the Manitoba Renal Program database. Sensitivity and specificity for KFRE risk thresholds (3% and 10% over 5 years were compared with eGFR thresholds (30 and 45 mL/min/1.73 m 2 . Results: Of 1512 included patients, 151 developed kidney failure over the 5-year follow-up period. The 4-variable KFRE showed a superior prognostic discrimination compared with eGFR alone (area under the receiver operating characteristic curve [AUROC] values, 0.90 [95% confidence interval {CI}: 0.88-0.92] for KFRE vs 0.78 [95% CI: 0.74-0.83] for eGFR. At a 3% threshold over 5 years, the KFRE had a sensitivity of 97% and a specificity of 62%. At 10% risk, sensitivity was 86%, and specificity was 80%. Limitations: Only 11.7% of stage 3-5 CKD patients had simultaneous ACR measurement. The KFRE does not account for other indications for referral such as suspected glomerulonephritis, polycystic kidney disease, and recurrent stone disease. Conclusions: The KFRE has been validated in a population with a demographic and referral

  5. Failure location prediction by finite element analysis for an additive manufactured mandible implant.

    Science.gov (United States)

    Huo, Jinxing; Dérand, Per; Rännar, Lars-Erik; Hirsch, Jan-Michaél; Gamstedt, E Kristofer

    2015-09-01

    In order to reconstruct a patient with a bone defect in the mandible, a porous scaffold attached to a plate, both in a titanium alloy, was designed and manufactured using additive manufacturing. Regrettably, the implant fractured in vivo several months after surgery. The aim of this study was to investigate the failure of the implant and show a way of predicting the mechanical properties of the implant before surgery. All computed tomography data of the patient were preprocessed to remove metallic artefacts with metal deletion technique before mandible geometry reconstruction. The three-dimensional geometry of the patient's mandible was also reconstructed, and the implant was fixed to the bone model with screws in Mimics medical imaging software. A finite element model was established from the assembly of the mandible and the implant to study stresses developed during mastication. The stress distribution in the load-bearing plate was computed, and the location of main stress concentration in the plate was determined. Comparison between the fracture region and the location of the stress concentration shows that finite element analysis could serve as a tool for optimizing the design of mandible implants. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  6. Ductile failure analysis of defective API X65 pipes based on stress-modified fracture strain criterion

    International Nuclear Information System (INIS)

    Oh, Chang Kyun; Kim, Yun Jae; Baek, Jong Hyun; Kim, Young Pyo; Kim, Woo Sik

    2006-01-01

    A local failure criterion for the API X65 steel is applied to predict ductile failure of full-scale API X65 pipes with simulated corrosion and gouge defects under internal pressure. The local failure criterion is the stress-modified fracture strain for the API X65 steel as a function of the stress triaxiality (defined by the ratio of the hydrostatic stress to the effective stress). Based on detailed FE analyses with the proposed local failure criteria, burst pressures of defective pipes are estimated and compared with experimental data. The predicted burst pressures are in good agreement with experimental data. Noting that an assessment equation against the gouge defect is not yet available, parametric study is performed, from which a simple equation is proposed to predict burst pressure for API X65 pipes with gouge defects

  7. Autoimmune premature ovarian failure

    Directory of Open Access Journals (Sweden)

    Beata Komorowska

    2017-02-01

    Full Text Available Premature ovarian failure (POF, also termed as primary ovarian insufficiency (POI, is a highly heterogenous condition affecting 0.5-3.0% of women in childbearing age. These young women comprise quite a formidable group with unique physical and psychological needs that require special attention. Premature ovarian senescence (POS in all of its forms evolves insidiously as a basically asymptomatic process, leading to complete loss of ovarian function, and POI/POF diagnoses are currently made at relatively late stages. Well-known and well-documented risk factors exist, and the presence or suspicion of autoimmune disorder should be regarded as an important one. Premature ovarian failure is to some degree predictable in its occurrence and should be considered while encountering young women with loss of menstrual regularity, especially when there is a concomitant dysfunction in the immune system.

  8. Failure criterion for graphene in biaxial loading—a molecular dynamics study

    International Nuclear Information System (INIS)

    Yazdani, Hessam; Hatami, Kianoosh

    2015-01-01

    Molecular dynamics simulations are carried out in order to develop a failure criterion for infinite/bulk graphene in biaxial tension. Stresses along the principal edge configurations of graphene (i.e. armchair and zigzag directions) are normalized to the corresponding uniaxial ultimate strength values. The combinations of normalized stresses resulting in the failure of graphene are used to define failure envelopes (limiting stress ratio surfaces). Results indicate that a bilinear failure envelope can be used to represent the tensile strength of graphene in biaxial loading at different temperatures with reasonable accuracy. A circular failure envelope is also introduced for practical applications. Both failure envelopes define temperature-independent upper limits for the feasible combinations of normalized stresses for a graphene sheet in biaxial loading. Predicted failure modes of graphene under biaxial loading are also shown and discussed. (paper)

  9. Development of evaluation method of fuel failure fraction during the High Temperature Engineering Test Reactor operation

    Energy Technology Data Exchange (ETDEWEB)

    Sawa, Kazuhiro; Yoshimuta, Shigeharu; Tobita, Tsutomu; Sato, Masashi [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1997-05-01

    The High Temperature Engineering Test Reactor (HTTR) uses coated particles as fuel. During normal operation, short-lived noble gases are mainly released by diffusion from fuel particles with defects in their coating layers (i.e., failed particle). Since noble gases do not plate out on the inner surfaces of primary cooling system, their activities in primary coolant reflect fuel failure fraction in the core. An evaluation method was developed to predict failure fraction of coated fuel particles during normal operation of the HTTR. The method predicts core-average and hot plenum regionwise failure fractions based on the fractional releases, (R/B)s, of noble gases. The (R/B)s are calculated by fission gas concentration measurements in the primary cooling system of the HTTR. Recent fabrication data show that through-coatings failure fraction is extremely low. Then, fractional release from matrix contamination uranium, which is background for accurate evaluation of the fuel failure fraction, should be precisely predicted. This report describes an evaluation method of fuel failure fraction from measurements in the HTTR together with a fission gas release model from fuel compact containing failed particles and matrix contamination uranium. (author)

  10. The Renal Arterial Resistance Index Predicts Worsening Renal Function in Chronic Heart Failure Patients

    Science.gov (United States)

    Iacoviello, Massimo; Monitillo, Francesco; Leone, Marta; Citarelli, Gaetano; Doronzo, Annalisa; Antoncecchi, Valeria; Puzzovivo, Agata; Rizzo, Caterina; Lattarulo, Maria Silvia; Massari, Francesco; Caldarola, Pasquale; Ciccone, Marco Matteo

    2016-01-01

    Background/Aim The renal arterial resistance index (RRI) is a Doppler measure, which reflects abnormalities in the renal blood flow. The aim of this study was to verify the value of RRI as a predictor of worsening renal function (WRF) in a group of chronic heart failure (CHF) outpatients. Methods We enrolled 266 patients in stable clinical conditions and on conventional therapy. Peak systolic velocity and end diastolic velocity of a segmental renal artery were obtained by pulsed Doppler flow, and RRI was calculated. Creatinine serum levels were evaluated at baseline and at 1 year, and the changes were used to assess WRF occurrence. Results During follow-up, 34 (13%) patients showed WRF. RRI was associated with WRF at univariate (OR: 1.13; 95% CI: 1.07–1.20) as well as at a forward stepwise multivariate logistic regression analysis (OR: 1.09; 95% CI: 1.03–1.16; p = 0.005) including the other univariate predictors. Conclusions Quantification of arterial renal perfusion provides a new parameter that independently predicts the WRF in CHF outpatients. Its possible role in current clinical practice to better define the risk of cardiorenal syndrome progression is strengthened. PMID:27994601

  11. Reactor pressure vessel failure probability following through-wall cracks due to pressurized thermal shock events

    International Nuclear Information System (INIS)

    Simonen, F.A.; Garnich, M.R.; Simonen, E.P.; Bian, S.H.; Nomura, K.K.; Anderson, W.E.; Pedersen, L.T.

    1986-04-01

    A fracture mechanics model was developed at the Pacific Northwest Laboratory (PNL) to predict the behavior of a reactor pressure vessel following a through-wall crack that occurs during a pressurized thermal shock (PTS) event. This study, which contributed to a US Nuclear Regulatory Commission (NRC) program to study PTS risk, was coordinated with the Integrated Pressurized Thermal Shock (IPTS) Program at Oak Ridge National Laboratory (ORNL). The PNL fracture mechanics model uses the critical transients and probabilities of through-wall cracks from the IPTS Program. The PNL model predicts the arrest, reinitiation, and direction of crack growth for a postulated through-wall crack and thereby predicts the mode of vessel failure. A Monte-Carlo type of computer code was written to predict the probabilities of the alternative failure modes. This code treats the fracture mechanics properties of the various welds and plates of a vessel as random variables. Plant-specific calculations were performed for the Oconee-1, Calvert Cliffs-1, and H.B. Robinson-2 reactor pressure vessels for the conditions of postulated transients. The model predicted that 50% or more of the through-wall axial cracks will turn to follow a circumferential weld. The predicted failure mode is a complete circumferential fracture of the vessel, which results in a potential vertically directed missile consisting of the upper head assembly. Missile arrest calculations for the three nuclear plants predict that such vertical missiles, as well as all potential horizontally directed fragmentation type missiles, will be confined to the vessel enclosre cavity. The PNL failure mode model is recommended for use in future evaluations of other plants, to determine the failure modes that are most probable for postulated PTS events

  12. Differential subsidence and its effect on subsurface infrastructure: predicting probability of pipeline failure (STOOP project)

    Science.gov (United States)

    de Bruijn, Renée; Dabekaussen, Willem; Hijma, Marc; Wiersma, Ane; Abspoel-Bukman, Linda; Boeije, Remco; Courage, Wim; van der Geest, Johan; Hamburg, Marc; Harmsma, Edwin; Helmholt, Kristian; van den Heuvel, Frank; Kruse, Henk; Langius, Erik; Lazovik, Elena

    2017-04-01

    Due to heterogeneity of the subsurface in the delta environment of the Netherlands, differential subsidence over short distances results in tension and subsequent wear of subsurface infrastructure, such as water and gas pipelines. Due to uncertainties in the build-up of the subsurface, however, it is unknown where this problem is the most prominent. This is a problem for asset managers deciding when a pipeline needs replacement: damaged pipelines endanger security of supply and pose a significant threat to safety, yet premature replacement raises needless expenses. In both cases, costs - financial or other - are high. Therefore, an interdisciplinary research team of geotechnicians, geologists and Big Data engineers from research institutes TNO, Deltares and SkyGeo developed a stochastic model to predict differential subsidence and the probability of consequent pipeline failure on a (sub-)street level. In this project pipeline data from company databases is combined with a stochastic geological model and information on (historical) groundwater levels and overburden material. Probability of pipeline failure is modelled by a coupling with a subsidence model and two separate models on pipeline behaviour under stress, using a probabilistic approach. The total length of pipelines (approx. 200.000 km operational in the Netherlands) and the complexity of the model chain that is needed to calculate a chance of failure, results in large computational challenges, as it requires massive evaluation of possible scenarios to reach the required level of confidence. To cope with this, a scalable computational infrastructure has been developed, composing a model workflow in which components have a heterogeneous technological basis. Three pilot areas covering an urban, a rural and a mixed environment, characterised by different groundwater-management strategies and different overburden histories, are used to evaluate the differences in subsidence and uncertainties that come with

  13. Comparing risk of failure models in water supply networks using ROC curves

    International Nuclear Information System (INIS)

    Debon, A.; Carrion, A.; Cabrera, E.; Solano, H.

    2010-01-01

    The problem of predicting the failure of water mains has been considered from different perspectives and using several methodologies in engineering literature. Nowadays, it is important to be able to accurately calculate the failure probabilities of pipes over time, since water company profits and service quality for citizens depend on pipe survival; forecasting pipe failures could have important economic and social implications. Quantitative tools (such as managerial or statistical indicators and reliable databases) are required in order to assess the current and future state of networks. Companies managing these networks are trying to establish models for evaluating the risk of failure in order to develop a proactive approach to the renewal process, instead of using traditional reactive pipe substitution schemes. The main objective of this paper is to compare models for evaluating the risk of failure in water supply networks. Using real data from a water supply company, this study has identified which network characteristics affect the risk of failure and which models better fit data to predict service breakdown. The comparison using the receiver operating characteristics (ROC) graph leads us to the conclusion that the best model is a generalized linear model. Also, we propose a procedure that can be applied to a pipe failure database, allowing the most appropriate decision rule to be chosen.

  14. Comparing risk of failure models in water supply networks using ROC curves

    Energy Technology Data Exchange (ETDEWEB)

    Debon, A., E-mail: andeau@eio.upv.e [Centro de Gestion de la Calidad y del Cambio, Dpt. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica de Valencia, E-46022 Valencia (Spain); Carrion, A. [Centro de Gestion de la Calidad y del Cambio, Dpt. Estadistica e Investigacion Operativa Aplicadas y Calidad, Universidad Politecnica de Valencia, E-46022 Valencia (Spain); Cabrera, E. [Dpto. De Ingenieria Hidraulica Y Medio Ambiente, Instituto Tecnologico del Agua, Universidad Politecnica de Valencia, E-46022 Valencia (Spain); Solano, H. [Universidad Diego Portales, Santiago (Chile)

    2010-01-15

    The problem of predicting the failure of water mains has been considered from different perspectives and using several methodologies in engineering literature. Nowadays, it is important to be able to accurately calculate the failure probabilities of pipes over time, since water company profits and service quality for citizens depend on pipe survival; forecasting pipe failures could have important economic and social implications. Quantitative tools (such as managerial or statistical indicators and reliable databases) are required in order to assess the current and future state of networks. Companies managing these networks are trying to establish models for evaluating the risk of failure in order to develop a proactive approach to the renewal process, instead of using traditional reactive pipe substitution schemes. The main objective of this paper is to compare models for evaluating the risk of failure in water supply networks. Using real data from a water supply company, this study has identified which network characteristics affect the risk of failure and which models better fit data to predict service breakdown. The comparison using the receiver operating characteristics (ROC) graph leads us to the conclusion that the best model is a generalized linear model. Also, we propose a procedure that can be applied to a pipe failure database, allowing the most appropriate decision rule to be chosen.

  15. Predictive modelling of survival and length of stay in critically ill patients using sequential organ failure scores.

    Science.gov (United States)

    Houthooft, Rein; Ruyssinck, Joeri; van der Herten, Joachim; Stijven, Sean; Couckuyt, Ivo; Gadeyne, Bram; Ongenae, Femke; Colpaert, Kirsten; Decruyenaere, Johan; Dhaene, Tom; De Turck, Filip

    2015-03-01

    The length of stay of critically ill patients in the intensive care unit (ICU) is an indication of patient ICU resource usage and varies considerably. Planning of postoperative ICU admissions is important as ICUs often have no nonoccupied beds available. Estimation of the ICU bed availability for the next coming days is entirely based on clinical judgement by intensivists and therefore too inaccurate. For this reason, predictive models have much potential for improving planning for ICU patient admission. Our goal is to develop and optimize models for patient survival and ICU length of stay (LOS) based on monitored ICU patient data. Furthermore, these models are compared on their use of sequential organ failure (SOFA) scores as well as underlying raw data as input features. Different machine learning techniques are trained, using a 14,480 patient dataset, both on SOFA scores as well as their underlying raw data values from the first five days after admission, in order to predict (i) the patient LOS, and (ii) the patient mortality. Furthermore, to help physicians in assessing the prediction credibility, a probabilistic model is tailored to the output of our best-performing model, assigning a belief to each patient status prediction. A two-by-two grid is built, using the classification outputs of the mortality and prolonged stay predictors to improve the patient LOS regression models. For predicting patient mortality and a prolonged stay, the best performing model is a support vector machine (SVM) with GA,D=65.9% (area under the curve (AUC) of 0.77) and GS,L=73.2% (AUC of 0.82). In terms of LOS regression, the best performing model is support vector regression, achieving a mean absolute error of 1.79 days and a median absolute error of 1.22 days for those patients surviving a nonprolonged stay. Using a classification grid based on the predicted patient mortality and prolonged stay, allows more accurate modeling of the patient LOS. The detailed models allow to support

  16. Cytokines and Organ Failure in Acute Pancreatitis

    DEFF Research Database (Denmark)

    Malmstrøm, Marie Louise; Hansen, Mark Berner; Andersen, Anders Møller

    2012-01-01

    Objectives: We aimed at synchronously examining the early time course of 4 proinflammatory cytokines as predictive factors for development of organ failure in patients with acute pancreatitis (AP). Methods: Interleukin (IL) 6, IL-8, IL-18, and tumor necrosis factor > were measured on admission...

  17. A new casemix adjustment index for hospital mortality among patients with congestive heart failure.

    Science.gov (United States)

    Polanczyk, C A; Rohde, L E; Philbin, E A; Di Salvo, T G

    1998-10-01

    Comparative analysis of hospital outcomes requires reliable adjustment for casemix. Although congestive heart failure is one of the most common indications for hospitalization, congestive heart failure casemix adjustment has not been widely studied. The purposes of this study were (1) to describe and validate a new congestive heart failure-specific casemix adjustment index to predict in-hospital mortality and (2) to compare its performance to the Charlson comorbidity index. Data from all 4,608 admissions to the Massachusetts General Hospital from January 1990 to July 1996 with a principal ICD-9-CM discharge diagnosis of congestive heart failure were evaluated. Massachusetts General Hospital patients were randomly divided in a derivation and a validation set. By logistic regression, odds ratios for in-hospital death were computed and weights were assigned to construct a new predictive index in the derivation set. The performance of the index was tested in an internal Massachusetts General Hospital validation set and in a non-Massachusetts General Hospital external validation set incorporating data from all 1995 New York state hospital discharges with a primary discharge diagnosis of congestive heart failure. Overall in-hospital mortality was 6.4%. Based on the new index, patients were assigned to six categories with incrementally increasing hospital mortality rates ranging from 0.5% to 31%. By logistic regression, "c" statistics of the congestive heart failure-specific index (0.83 and 0.78, derivation and validation set) were significantly superior to the Charlson index (0.66). Similar incrementally increasing hospital mortality rates were observed in the New York database with the congestive heart failure-specific index ("c" statistics 0.75). In an administrative database, this congestive heart failure-specific index may be a more adequate casemix adjustment tool to predict hospital mortality in patients hospitalized for congestive heart failure.

  18. New product failure

    DEFF Research Database (Denmark)

    Dijksterhuis, Garmt Bernard

    2016-01-01

    When new consumer products are developed and later launched, 50 to 75 percent of them are removed from the market far short of meeting their projected financial targets. In short: they fail. We conclude that this failure is due to institutionalized insufficiencies in the use of the sciences...... that are best geared to understand and predict consumer behaviour, viz. the behavioural sciences. These are not necessarily the same as the marketing science that is performed by marketing departments. A scientific approach to understanding consumer behaviour appears to be lacking in many corporate research...

  19. Hemodynamic changes during weaning: can we assess and predict cardiac-related weaning failure by transthoracic echocardiography?

    Science.gov (United States)

    Voga, Gorazd

    2010-01-01

    Cardiac-related failure of weaning from mechanical ventilation is an important reason for prolonged mechanical ventilation, intensive care unit treatment, and increased morbidity and mortality. When transthoracic echocardiography (TTE) is routinely performed before a weaning trial, patients at high risk of cardiac-related failure can be detected by low left ventricular (LV) ejection fraction, diastolic dysfunction, and elevated LV filling pressure. During the weaning trial, a further increase of LV filling pressure and progression of diastolic failure can be observed by repeated TTE. Owing to certain limitations concerning patients and methodology, TTE cannot be employed in every patient and invasive hemodynamic monitoring is still mandatory in selected patients with repetitive weaning failure.

  20. LSTM-Based Temperature Prediction for Hot-Axles of Locomotives

    Directory of Open Access Journals (Sweden)

    Luo Can

    2017-01-01

    Full Text Available The reliability of locomotives plays a central role for the smooth operation of railway systems. Hot-axle failures are one of the most commonly found problems leading to locomotive accidents. Since the operating status of the locomotive axle bearings can be distinctly reflected by the axle temperatures, online temperature monitoring has become an essential way to detect hot-axle failures. In this work, we explore the feasibility of predict the hot-axle failures by identifying the temperature from predicted nominal values. We propose a data-driven approach based on the Long Short-Term Memory (LSTM network to predict the sensor temperature for axle bearings. The effectiveness of the prediction model was validated with operation data collected from commercial locomotives. With a prediction accuracy is within a few percent, the proposed techniques can be used as a dynamic reference for hot-axle monitoring.