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Sample records for stress intensity values

  1. Stress concentration factor and stress intensity factor on hard metals in connection with the wear characteristics

    International Nuclear Information System (INIS)

    Dawihl, W.; Altmeyer, G.

    1977-01-01

    Description of a method to determine stress intensity factors on hard metals by lapping in notches of different diameter. Dependence of the values of the stress intensity factors on the size of the notch base diameter. For tungsten carbide hard metals with 6% Co, determination of a final value of 250 Nmm -3 / 2 . Characterisation of the stress intensity factor governed by the surface roughness which is decisive for the assessment of the wear-resistant behaviour. (orig.) [de

  2. Steganography based on pixel intensity value decomposition

    Science.gov (United States)

    Abdulla, Alan Anwar; Sellahewa, Harin; Jassim, Sabah A.

    2014-05-01

    This paper focuses on steganography based on pixel intensity value decomposition. A number of existing schemes such as binary, Fibonacci, Prime, Natural, Lucas, and Catalan-Fibonacci (CF) are evaluated in terms of payload capacity and stego quality. A new technique based on a specific representation is proposed to decompose pixel intensity values into 16 (virtual) bit-planes suitable for embedding purposes. The proposed decomposition has a desirable property whereby the sum of all bit-planes does not exceed the maximum pixel intensity value, i.e. 255. Experimental results demonstrate that the proposed technique offers an effective compromise between payload capacity and stego quality of existing embedding techniques based on pixel intensity value decomposition. Its capacity is equal to that of binary and Lucas, while it offers a higher capacity than Fibonacci, Prime, Natural, and CF when the secret bits are embedded in 1st Least Significant Bit (LSB). When the secret bits are embedded in higher bit-planes, i.e., 2nd LSB to 8th Most Significant Bit (MSB), the proposed scheme has more capacity than Natural numbers based embedding. However, from the 6th bit-plane onwards, the proposed scheme offers better stego quality. In general, the proposed decomposition scheme has less effect in terms of quality on pixel value when compared to most existing pixel intensity value decomposition techniques when embedding messages in higher bit-planes.

  3. Stress intensities in flawed pressure vessels

    International Nuclear Information System (INIS)

    Smith, C.W.; Jolles, M.; Peters, W.H.

    1977-01-01

    A technique for determining the stess intensity factor (SIF) near pressure vessel flaws or cracks experimentally from photoelastic data for use in two-dimensional problems was developed in the 1950's. This technique was modified and extended to a variety of two-dimensional problems. The technique has been refined further and what has evolved may be regarded as a hybrid technique which affects a marriage between ''frozen stress'' photoelastic results and a simple least-squares digital computer program for estimating SIF values in three-dimensional problems. This technique, in its original modified form, has been shown to be applicable to a study of surface flaws and the applicability of the method to complex crack body geometries of current technological importance are discussed. The analytical foundations of the method are reviewed

  4. Stress Concentration Factor and Stress Intensity Factor with U-notch and Crack in the Beam

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Bo Seong; Lee, Kwang Ho [Kyungpook National Univ., Daegu (Korea, Republic of)

    2016-05-15

    The stress concentration factors and stress intensity factors for a simple beam and a cantilever are analyzed by using finite element method and photoelasticity. Using the analyzed results, the estimated graphs on stress concentration factors and stress intensity factors are obtained. To analyze stress concentration factors of notch, the dimensionless notch length H(height of specimen)/h=1.1-2 and dimensionless gap space r(radius at the notch tip)/h=0.1~0.5 are used, where h=H-c and c is the notch length. As the notch gap length increases and the gap decreases, the stress concentration factors increase. Stress concentration factors of a simple beam are greater than those of a cantilever beam. However, actually, the maximum stress values under a load, a notch length and a gap occur more greatly in the cantilever beam than in the simple beam. To analyze stress intensity factors, the normalized crack length α(crack length)/H=0.2~0.5 is used. As the length of the crack increases, the normalized stress intensity factors increase. The stress intensity factors under a constant load and a crack length occur more greatly in the cantilever beam than in the simple beam.

  5. Stress intensity factors and constant stress terms for interface cracks

    International Nuclear Information System (INIS)

    Fett, T.; Rizzi, G.

    2004-01-01

    In bi-material joints cracks can propagate along the interface or kink into one of the two materials. Whereas the energy release rate can be applied for interface cracks in the same way as usual for homogeneous materials, the computation of stresses in the vicinity of the crack tip is significantly more complicated. In order to assess crack kinking, it is necessary to know the mixed-mode stress intensity factor contributions K I and K II as well as the constant stress terms in the two materials. Whereas the stress intensity factors are available for a large number of infinite and semi-infinite bodies, there is experimental interest in practically used test specimens. This especially holds for the constant x-stress terms. Finite element computations are performed for the special case of a disappearing second Dundurs parameter, i.e. β=0. The fracture mechanics parameters K I , K II , σ 0 for the interface crack are reported in the form of diagrams and approximate relations. (orig.)

  6. Computation of principal stresses and stress intensity of a nozzle on a spherical pressure vessel

    International Nuclear Information System (INIS)

    Sun, B.C.; Lyow, B.L.; Koplik, B.

    1993-01-01

    This paper presents a Stress Computation Table that systematically computes the local stresses at various locations of the sphere-nozzle intersection. The six components of external loading are: radial load, two overturning moments, two horizontal shear forces, and a torsional moment. The radial and overturning moments induce local membrane and bending stresses in both the circumferential and meridional directions of the sphere around the nozzle. The shear forces and torsional moment produce local shear stresses. In addition, the shear forces induce local membrane and bending stresses around the nozzle. The local stress factors from each external loading component are taken from recent publications by Lyow, Sun and Koplik who have studied this subject through the use of the finite element method. These factors are a function of the nozzle-sphere geometrical parameters, beta, β, (nozzle radius/sphere radius) and gamma, γ, (sphere radius/thickness), with the beta value ranging from 0.1 to 0.5, and the gamma value ranging from 10 to 100. The Stress Table summarizes all the normal and shear stresses at eight different locations around the nozzle, and finally the principal stresses and stress intensity are computed. The stress factor plots from previous publications are replotted in this paper to provide a handy reference as well as consistency. A numerical sample employing a FORTRAN program is also given. (author)

  7. Effects of overload on the threshold stress intensity factor for SCC

    International Nuclear Information System (INIS)

    Takahashi, Koji; Ando, Kotoji; Miyazaki, Yuji; Hashikura, Yasuaki

    2009-01-01

    The effects of overload on the threshold stress intensity factor for stress corrosion crack (K ISCC ) of stainless steel were studied. Tensile overload was applied to a wedge opening loaded (WOL) specimen of SUS316. Then, SCC tests were carried out to determine the resultant K ISCC . As a result, the apparent value of K ISCC increases as increasing a stress intensity factor by tensile overload (K OV ). The effects of tensile overload on K ISCC and the threshold stress intensity factor range for fatigue (ΔK th ) were compared. It was found that the effects of tensile overload on K ISCC were larger than that on ΔK th . (author)

  8. Guideline for stress ulcer prophylaxis in the intensive care unit

    DEFF Research Database (Denmark)

    Madsen, Kristian Rørbaek; Lorentzen, Kristian; Clausen, Niels

    2014-01-01

    Stress ulcer prophylaxis (SUP) is commonly used in the intensive care unit (ICU), and is recommended in the Surviving Sepsis Campaign guidelines 2012. The present guideline from the Danish Society of Intensive Care Medicine and the Danish Society of Anesthesiology and Intensive Care Medicine sums...

  9. Effect of Couple Stresses on the Stress Intensity Factors for Two Parallel Cracks in an Infinite Elastic Medium under Tension

    Directory of Open Access Journals (Sweden)

    Shouetsu Itou

    2012-01-01

    Full Text Available Stresses around two parallel cracks of equal length in an infinite elastic medium are evaluated based on the linearized couple-stress theory under uniform tension normal to the cracks. Fourier transformations are used to reduce the boundary conditions with respect to the upper crack to dual integral equations. In order to solve these equations, the differences in the displacements and in the rotation at the upper crack are expanded through a series of functions that are zero valued outside the crack. The unknown coefficients in each series are solved in order to satisfy the boundary conditions inside the crack using the Schmidt method. The stresses are expressed in terms of infinite integrals, and the stress intensity factors can be determined using the characteristics of the integrands for an infinite value of the variable of integration. Numerical calculations are carried out for selected crack configurations, and the effect of the couple stresses on the stress intensity factors is revealed.

  10. Extraversion and cardiovascular responses to recurrent social stress: Effect of stress intensity.

    Science.gov (United States)

    Lü, Wei; Xing, Wanying; Hughes, Brian M; Wang, Zhenhong

    2017-10-28

    The present study sought to establish whether the effects of extraversion on cardiovascular responses to recurrent social stress are contingent on stress intensity. A 2×5×1 mixed-factorial experiment was conducted, with social stress intensity as a between-subject variable, study phase as a within-subject variable, extraversion as a continuous independent variable, and cardiovascular parameter (HR, SBP, DBP, or RSA) as a dependent variable. Extraversion (NEO-FFI), subjective stress, and physiological stress were measured in 166 undergraduate students randomly assigned to undergo moderate (n=82) or high-intensity (n=84) social stress (a public speaking task with different levels of social evaluation). All participants underwent continuous physiological monitoring while facing two consecutive stress exposures distributed across five laboratory phases: baseline, stress exposure 1, post-stress 1, stress exposure 2, post-stress 2. Results indicated that under moderate-intensity social stress, participants higher on extraversion exhibited lesser HR reactivity to stress than participants lower on extraversion, while under high-intensity social stress, they exhibited greater HR, SBP, DBP and RSA reactivity. Under both moderate- and high-intensity social stress, participants higher on extraversion exhibited pronounced SBP and DBP response adaptation to repeated stress, and showed either better degree of HR recovery or greater amount of SBP and DBP recovery after stress. These findings suggest that individuals higher on extraversion exhibit physiological flexibility to cope with social challenges and benefit from adaptive cardiovascular responses. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Use of frozen stress in extracting stress intensity factor distributions in three dimensional cracked body problems

    Science.gov (United States)

    Smith, C. W.

    1992-01-01

    The adaptation of the frozen stress photoelastic method to the determination of the distribution of stress intensity factors in three dimensional problems is briefly reviewed. The method is then applied to several engineering problems of practical significance.

  12. Numerical Determination of Crack Opening and Closure Stress Intensity Factors

    DEFF Research Database (Denmark)

    Ricardo, Luiz Carlos Hernandes

    2009-01-01

    The present work shows the numerical determination of fatigue crack opening and closure stress intensity factors of a C(T) specimen under variable amplitude loading using a finite element method. A half compact tension C(T) specimen, assuming plane stress constraint was used by finite element...

  13. Human Capital-Intensive Firms and Symbolic Value Creation

    Directory of Open Access Journals (Sweden)

    Cezanne Cécile

    2014-06-01

    Full Text Available The aim of this paper is to study the process of symbolic value creation of human capital-intensive firms. Human capital is a critical resource for firms’ activities. Nevertheless, this dimension is often obscured by industrial economists. In the light of critical resource theory, we analyze how taking into account the inalienable and inimitable nature of specific human capital entails a reconsideration of the role and boundaries of the firm. We show that the firm seeks to coordinate the specialization of its key partners within the frame of its economic boundaries to ensure the long-term optimization of its potential of value. Therefore, the value of the firm depends on all the resources that the firm coordinates. Then we focus on the way HCIF can create different values. We suggest that the firm builds its competitive advantage on different forms of values, in particular the symbolic value incorporated in human capital. Finally, on the basis of these considerations, we identify the wealth included in the critical resources of the firm and to bring to light the process of symbolic value creation associated with it. We suggest that the firm is the value creating entity and the customer both recognizes and derives the value created from whatever it is that the firm provides. We propose a definition of this value and a schema of its creation process based on management works attempts. We conclude by proposing paths of research that could fruitfully be explored to further develop this new subject.

  14. High intensity and reduced volume training attenuates stress and recovery levels in elite swimmers

    DEFF Research Database (Denmark)

    Elbe, Anne-Marie; Rasmussen, Camilla P; Nielsen, Glen

    2016-01-01

    This study investigated the effect of increased high-intensity interval training (HIT) at the expense of total training volume on the stress and recovery levels of elite swimmers. Forty-one elite swimmers participated in the study and were randomly assigned to either a HIT or a control group (CON....... The Recovery Stress Questionnaire - Sport was used to measure the swimmers' stress and recovery levels. After the 12 week intervention, the general stress level was 16.6% (2.6-30.7%; mean and 95% CI) lower and the general recovery level was 6.5% (0.7-12.4%) higher in HIT compared to the CON, after adjusting...... for baseline values. No significant effects could be observed in sports-specific stress or sports-specific recovery. The results indicate that increasing training intensity and reducing training volume for 12 weeks can reduce general stress and increase general recovery levels in competitive swimmers....

  15. Estimation of stress intensity factors for circumferential cracked pipes under welding residual stress filed

    International Nuclear Information System (INIS)

    Oh, Chang Young; Kim, Yun Jae; Oh, Young Jin; Song, Tae Kwang; Kim, Yong Beum; Oh, Young Jin; Song, Tae Kwang; Kim, Yong Beum

    2012-01-01

    Recently, stress corrosion cracking(SCC) have been found in dissimilar metal welds of nozzles in some pressurized water reactors and on low carbon stainless steel piping systems of boiling water reactors. The important factor of SCC is the residual stress field caused by weld. For the evaluation of crack growth analysis due to SCC, stress intensity factor under a residual stress field should be estimated. Several solutions for stress intensity factor under residual stress field were recommended in flaw assessment codes such as the American Society of Mechanical Engineers (ASME) Section XI, R6, American Petroleum Institute (API579). Some relevant works have been studied. Dong et al. evaluated stress intensity factors in welded structures. Miyazaki et al. estimated stress intensity factors of surface crack in simple stress fields. This paper presents a simple method to estimate stress intensity factors in welding residual stress field. For general application, results of structure integrity assessment codes KI solutions were compared Finite element analyses of welding simulation and cracked pipes are described. Comparison results of KI solutions and proposed simplified solution are presented in the works

  16. The maximum possible stress intensity factor for a crack in an unknown residual stress field

    International Nuclear Information System (INIS)

    Coules, H.E.; Smith, D.J.

    2015-01-01

    Residual and thermal stress fields in engineering components can act on cracks and structural flaws, promoting or inhibiting fracture. However, these stresses are limited in magnitude by the ability of materials to sustain them elastically. As a consequence, the stress intensity factor which can be applied to a given defect by a self-equilibrating stress field is also limited. We propose a simple weight function method for determining the maximum stress intensity factor which can occur for a given crack or defect in a one-dimensional self-equilibrating stress field, i.e. an upper bound for the residual stress contribution to K I . This can be used for analysing structures containing defects and subject to residual stress without any information about the actual stress field which exists in the structure being analysed. A number of examples are given, including long radial cracks and fully-circumferential cracks in thick-walled hollow cylinders containing self-equilibrating stresses. - Highlights: • An upper limit to the contribution of residual stress to stress intensity factor. • The maximum K I for self-equilibrating stresses in several geometries is calculated. • A weight function method can determine this maximum for 1-dimensional stress fields. • Simple MATLAB scripts for calculating maximum K I provided as supplementary material.

  17. Fathers' Stress in a Neonatal Intensive Care Unit

    DEFF Research Database (Denmark)

    Noergaard, Betty; Ammentorp, Jette; Garne, Ester

    2018-01-01

    BACKGROUND: Healthcare professionals in neonatal intensive care units (NICUs) tend to focus attention on the mothers and the newborn infants. Thus, fathers may find it difficult to establish an optimal father-child relationship and their stress may increase and persist during hospitalization...... and expect fathers to be involved, and support them to establish a father-child relationship, although they might become more stressed. IMPLICATIONS FOR RESEARCH: More adequate outcome measures are needed to determine the effect of interventions on paternal stress.This is an open-access article distributed....... PURPOSE: To investigate the impact of a more father-friendly NICU on paternal stress and their participation in childcare. METHODS: A quasiexperimental design was conducted on Danish-speaking fathers of newborn infants 28 or more weeks' gestational age. The Parental Stressor Scale: Neonatal Intensive Care...

  18. Guideline for stress ulcer prophylaxis in the intensive care unit

    DEFF Research Database (Denmark)

    Madsen, Kristian Rørbaek; Lorentzen, Kristian; Clausen, Niels

    2014-01-01

    Stress ulcer prophylaxis (SUP) is commonly used in the intensive care unit (ICU), and is recommended in the Surviving Sepsis Campaign guidelines 2012. The present guideline from the Danish Society of Intensive Care Medicine and the Danish Society of Anesthesiology and Intensive Care Medicine sums...... critically ill patients in the ICU outside the context of randomized controlled trials (GRADE 1C). No robust evidence supports recommendations for subpopulations in the ICU such as septic, burn, trauma, cardiothoracic or enterally fed patients. However, if SUP is considered clinically indicated in individual...

  19. Evaluation of stress intensity factors due to welding residual stresses for circumferential cracked pipes

    International Nuclear Information System (INIS)

    Oh, Chang-Young; Kim, Yun-Jae; Oh, Young-Jin; Kim, Jong-Sung; Song, Tae-Kwang; Kim, Yong-Beum

    2013-01-01

    To investigate the applicability of existing methods to estimate stress intensity factors due to welding residual stresses, comparisons with finite element (FE) solutions are made for two types of generic welding residual stress profiles, generated by simulating repair welds. It is found that fitting residual stresses over the crack depth using third-order polynomials gives good estimates of stress intensity factors but fitting over the entire thickness can result in inaccurate estimates even with fourth-order polynomials. Noting that welding residual stresses are often determined from FE analyses, linearization of residual stresses to estimate stress intensity factors is proposed. Comparison with FE solutions shows good agreements. -- Highlights: ► Applicability of K estimation methods is investigated for welding residual stresses. ► Two types of generic residual stress profiles with repair welds are considered. ► Fitting residual stresses over the crack depth gives good estimates of K. ► A method to estimate K by linearising residual stress profiles is proposed

  20. IT Business Value Model for Information Intensive Organizations

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Gastaud Maçada

    2012-01-01

    Full Text Available Many studies have highlighted the capacity Information Technology (IT has for generating value for organizations. Investments in IT made by organizations have increased each year. Therefore, the purpose of the present study is to analyze the IT Business Value for Information Intensive Organizations (IIO - e.g. banks, insurance companies and securities brokers. The research method consisted of a survey that used and combined the models from Weill and Broadbent (1998 and Gregor, Martin, Fernandez, Stern and Vitale (2006. Data was gathered using an adapted instrument containing 5 dimensions (Strategic, Informational, Transactional, Transformational and Infra-structure with 27 items. The instrument was refined by employing statistical techniques such as Exploratory and Confirmatory Factorial Analysis through Structural Equations (first and second order Model Measurement. The final model is composed of four factors related to IT Business Value: Strategic, Informational, Transactional and Transformational, arranged in 15 items. The dimension Infra-structure was excluded during the model refinement process because it was discovered during interviews that managers were unable to perceive it as a distinct dimension of IT Business Value.

  1. Post-traumatic stress disorder in intensive care unit patients.

    Science.gov (United States)

    Caiuby, Andrea Vannini Santesso; Andreoli, Paola Bruno de Araújo; Andreoli, Sergio Baxter

    2010-03-01

    Post-traumatic stress disorder has been detected in patients after treatment in intensive care unit. The main goal of this study is to review the psychological aspects and therapeutic interventions on those patients after their treatment on intensive care unit. Thirty eight articles have been included. The prevalence of post-traumatic stress disorder has varied from 17% up to 30% and the incidence from 14% to 24%. The risk factors were: previous anxiety historic, depression or panic, having delusional traumatic memories (derived from psychic formations as dreams and delirium), belief effects, depressive behavior, stressing experiences and mechanical ventilation. High doses of opiates, symptoms caused by sedation or analgesia reduction and the use of lorazepam were related with the increase of delirium and delusional memory. The disorder sintomatology can be reduced with hydrocortisone administration, with daily sedation interruption. No other effectiveness psychological intervention study was found.

  2. Calculations of the stress intensity factor on a specimen for a four-point bend

    International Nuclear Information System (INIS)

    Lauerova, D.

    1995-02-01

    The stress intensity factor K I was calculated in dependence on the crack length in a sample for a (non-standard) four-point bend assuming elastic properties of the material. It is shown that the SYSTUS code gives the best results when calculating the K I value from the J-integral. 4 tabs., 12 figs., 4 refs

  3. Stressful life events and acute kidney injury in intensive and semi-intensive care unities.

    Science.gov (United States)

    Diniz, Denise Para; Marques, Daniella Aparecida; Blay, Sérgio Luis; Schor, Nestor

    2012-03-01

    Several studies point out that pathophysiological changes related to stress may influence renal function and are associated with disease onset and evolution. However, we have not found any studies about the influence of stress on renal function and acute kidney injury. To evaluate the association between stressful life events and acute kidney injury diagnosis, specifying the most stressful classes of events for these patients in the past 12 months. Case-control study. The study was carried out at Hospital São Paulo, in Universidade Federal de São Paulo and at Hospital dos Servidores do Estado de São Paulo, in Brazil. Patients with acute kidney injury and no chronic disease, admitted to the intensive or semi-intensive care units were included. Controls included patients in the same intensive care units with other acute diseases, except for the acute kidney injury, and also with no chronic disease. Out of the 579 patients initially identified, 475 answered to the Social Readjustment Rating Scale (SRRS) questionnaire and 398 were paired by age and gender (199 cases and 199 controls). The rate of stressful life events was statistically similar between cases and controls. The logistic regression analysis to detect associated effects of the independent variables to the stressful events showed that: increasing age and economic classes A and B in one of the hospitals (Hospital São Paulo - UNIFESP) increased the chance of a stressful life event (SLE). This study did not show association between the Acute Kidney Injury Group with a higher frequency of stressful life events, but that old age, higher income, and type of clinical center were associated.

  4. Modified stress intensity factor as a crack growth parameter applicable under large scale yielding conditions

    International Nuclear Information System (INIS)

    Yasuoka, Tetsuo; Mizutani, Yoshihiro; Todoroki, Akira

    2014-01-01

    High-temperature water stress corrosion cracking has high tensile stress sensitivity, and its growth rate has been evaluated using the stress intensity factor, which is a linear fracture mechanics parameter. Stress corrosion cracking mainly occurs and propagates around welded metals or heat-affected zones. These regions have complex residual stress distributions and yield strength distributions because of input heat effects. The authors previously reported that the stress intensity factor becomes inapplicable when steep residual stress distributions or yield strength distributions occur along the crack propagation path, because small-scale yielding conditions deviate around those distributions. Here, when the stress intensity factor is modified by considering these distributions, the modified stress intensity factor may be used for crack growth evaluation for large-scale yielding. The authors previously proposed a modified stress intensity factor incorporating the stress distribution or yield strength distribution in front of the crack using the rate of change of stress intensity factor and yield strength. However, the applicable range of modified stress intensity factor for large-scale yielding was not clarified. In this study, the range was analytically investigated by comparison with the J-integral solution. A three-point bending specimen with parallel surface crack was adopted as the analytical model and the stress intensity factor, modified stress intensity factor and equivalent stress intensity factor derived from the J-integral were calculated and compared under large-scale yielding conditions. The modified stress intensity was closer to the equivalent stress intensity factor when compared with the stress intensity factor. If deviation from the J-integral solution is acceptable up to 2%, the modified stress intensity factor is applicable up to 30% of the J-integral limit, while the stress intensity factor is applicable up to 10%. These results showed that

  5. Stress ulcer prophylaxis in the intensive care unit

    DEFF Research Database (Denmark)

    Krag, Morten Brøgger; Perner, A; Wetterslev, J

    2013-01-01

    Stress ulcer prophylaxis (SUP) is regarded as standard of care in the intensive care unit (ICU). However, recent randomized, clinical trials (RCTs) and meta-analyses have questioned the rationale and level of evidence for this recommendation. The aim of the present systematic review was to evaluate...... incidence of gastrointestinal (GI) bleeding varies considerably. Data on the incidence and severity of GI bleeding in general ICUs in the developed world as of today are lacking. The best intervention for SUP is yet to be settled by balancing efficacy and harm. In essence, it is unresolved if intensive care...... patients benefit overall from SUP. The following clinically research questions are unanswered: (1) What is the incidence of GI bleeding, and which interventions are used for SUP in general ICUs today?; (2) Which criteria are used to prescribe SUP?; (3) What is the best SUP intervention?; (4) Do intensive...

  6. Stress ulcer prophylaxis in the intensive care unit trial

    DEFF Research Database (Denmark)

    Krag, M; Perner, A; Wetterslev, J

    2017-01-01

    BACKGROUND: In this statistical analysis plan, we aim to provide details of the pre-defined statistical analyses of the Stress Ulcer Prophylaxis in the Intensive Care Unit (SUP-ICU) trial. The aim of the SUP-ICU trial is to assess benefits and harms of stress ulcer prophylaxis with a proton pump......-year mortality, and a health economic analysis. Two formal interim analyses will be performed. The statistical analyses will be conducted according to the outlined pre-defined statistical analysis plan. The primary analysis will be a logistic regression analysis adjusted for stratification variables...... comparing the two intervention groups in the intention-to-treat population. In a secondary analysis, we will additionally adjust the primary outcome for potential random differences in baseline characteristics. The conclusion will be based on the intention-to-treat population. CONCLUSION: Stress ulcer...

  7. Teacher Stress and Personal Values. An Exploratory Study

    Science.gov (United States)

    Bachkirova, Tatiana

    2005-01-01

    This article presents the first stage of a small-scale research project into the relationship between teacher stress and personal values. It starts by outlining the problem of teacher stress and an overview of the literature investigating the sources of it. A particular combination of factors related to personal values that may increase…

  8. Transient thermal stresses and stress intensity factors induced by thermal stratification in feedwater lines

    International Nuclear Information System (INIS)

    Sanchez Sarmiento, G.; Pardo, E.

    1985-01-01

    General analytical solutions for the thermal stresses and circumferential crack propagation in piping branches of nuclear power plants, that connect two circuits of the same fluid at different temperatures, are presented in this paper. Under certain conditions, two regions of the fluid possessing both temperatures with a separating layer of small thickness are formed ('flow stratification'). Dimensionless analytical expressions for the steady state temperature distribution in the pipe wall and the corresponding thermal stress are here derived, in terms of the basic geometrical and physical parameters. The position and thickness of the separating layer are considered as data of the model. Stress intensity ranges at any point of the tube wall are then determined. Finally, thermally induced stress intensity factors are calculated for hipothetically inside surface cracks. (orig.)

  9. Posttraumatic stress in intensive care unit survivors - a prospective study

    DEFF Research Database (Denmark)

    Ratzer, Mette; Brink, Ole; Knudsen, Linda

    2014-01-01

    Aims: This study aimed to estimate the prevalence of severe Posttraumatic Stress Disorder (PTSD) symptoms and to identify factors associated with PTSD in survivors of intensive care unit (ICU) treatment following traumatic injury. Methods: Fifty-two patients who were admitted to an ICU through...... the emergency ward following traumatic injury were prospectively followed. Information on injury severity and ICU treatment were obtained through medical records. Demographic information and measures of acute stress symptoms, experienced social support, coping style, sense of coherence (SOC) and locus...... of control were assessed within one-month post-accident (T1). At the six months follow-up (T2), PTSD was assessed with the Harvard Trauma Questionnaire (HTQ). Results: In the six months follow-up, 10 respondents (19.2%) had HTQ total scores reaching a level suggestive of PTSD (N = 52), and 11 respondents (21...

  10. Noise, stress, and annoyance in a pediatric intensive care unit.

    Science.gov (United States)

    Morrison, Wynne E; Haas, Ellen C; Shaffner, Donald H; Garrett, Elizabeth S; Fackler, James C

    2003-01-01

    To measure and describe hospital noise and determine whether noise can be correlated with nursing stress measured by questionnaire, salivary amylase, and heart rate. Cohort observational study. Tertiary care center pediatric intensive care unit. Registered nurses working in the unit. None. Eleven nurse volunteers were recruited. An audiogram, questionnaire data, salivary amylase, and heart rate were collected in a quiet room. Each nurse was observed for a 3-hr period during patient care. Heart rate and sound level were recorded continuously; saliva samples and stress/annoyance ratings were collected every 30 mins. Variables assessed as potential confounders were years of nursing experience, caffeine intake, patients' Pediatric Risk of Mortality Score, shift assignment, and room assignment. Data were analyzed by random effects multiple linear regression using Stata 6.0. The average daytime sound level was 61 dB(A), nighttime 59 dB(A). Higher average sound levels significantly predicted higher heart rates (p =.014). Other significant predictors of tachycardia were higher caffeine intake, less nursing experience, and daytime shift. Ninety percent of the variability in heart rate was explained by the regression equation. Amylase measurements showed a large variability and were not significantly affected by noise levels. Higher average sound levels were also predictive of greater subjective stress (p =.021) and annoyance (p =.016). In this small study, noise was shown to correlate with several measures of stress including tachycardia and annoyance ratings. Further studies of interventions to reduce noise are essential.

  11. Determinants of stress for staff in a neonatal intensive care unit.

    OpenAIRE

    Astbury, J; Yu, V Y

    1982-01-01

    Components of stress for 22 paediatric consultants and 29 nursing sisters working in neonatal intensive care units were studied. Ten situations were rated for their intensity of stress and their frequency of occurrence. For intensity of stress, significantly more paediatric consultants rated the competing demands of personal life versus work as highly stressful, than did nursing sisters. For frequency of stress, significantly more paediatric consultants rated 4 situations as frequently occurr...

  12. Resolved shear stress intensity coefficient and fatigue crack growth in large crystals

    Science.gov (United States)

    Chen, QI; Liu, Hao-Wen

    1988-01-01

    Fatigue crack growth in large grain Al alloy was studied. Fatigue crack growth is caused primarily by shear decohesion due to dislocation motion in the crack tip region. The crack paths in the large crystals are very irregular and zigzag. The crack planes are often inclined to the loading axis both in the inplane direction and the thickness direction. The stress intensity factors of such inclined cracks are approximated from the two dimensional finite element calculations. The plastic deformation in a large crystal is highly anisotropic, and dislocation motion in such crystals are driven by the resolved shear stress. The resolved shear stress intensity coefficient in a crack solid, RSSIC, is defined, and the coefficients for the slip systems at a crack tip are evaluated from the calculated stress intensity factors. The orientations of the crack planes are closely related to the slip planes with the high RSSIC values. If a single slip system has a much higher RSSIC than all the others, the crack will follow the slip plane, and the slip plane becomes the crack plane. If two or more slip systems have a high RSSIC, the crack plane is the result of the decohesion processes on these active slip planes.

  13. Stress ulcer prophylaxis in the intensive care unit

    DEFF Research Database (Denmark)

    Krag, M; Perner, A; Wetterslev, J

    2015-01-01

    BACKGROUND: Stress ulcer prophylaxis (SUP) may decrease the incidence of gastrointestinal bleeding in patients in the intensive care unit (ICU), but the risk of infection may be increased. In this study, we aimed to describe SUP practices in adult ICUs. We hypothesised that patient selection...... for SUP varies both within and between countries. METHODS: Adult ICUs were invited to participate in the survey. We registered country, type of hospital, type and size of ICU, preferred SUP agent, presence of local guideline, reported indications for SUP, criteria for discontinuing SUP, and concerns about...... adverse effects. Fisher's exact test was used to assess differences between groups. RESULTS: Ninety-seven adult ICUs in 11 countries participated (eight European). All but one ICU used SUP, and 64% (62/97) reported having a guideline for the use of SUP. Proton pump inhibitors were the most common SUP...

  14. Intensity of anxiety is modified via complex integrative stress circuitries.

    Science.gov (United States)

    Smith, Justin P; Prince, Melissa A; Achua, Justin K; Robertson, James M; Anderson, Raymond T; Ronan, Patrick J; Summers, Cliff H

    2016-01-01

    Escalation of anxious behavior while environmentally and socially relevant contextual events amplify the intensity of emotional response produces a testable gradient of anxiety shaped by integrative circuitries. Apprehension of the Stress-Alternatives Model apparatus (SAM) oval open field (OF) is measured by the active latency to escape, and is delayed by unfamiliarity with the passageway. Familiar OF escape is the least anxious behavior along the continuum, which can be reduced by anxiolytics such as icv neuropeptide S (NPS). Social aggression increases anxiousness in the SAM, reducing the number of mice willing to escape by 50%. The apprehension accompanying escape during social aggression is diminished by anxiolytics, such as exercise and corticotropin releasing-factor receptor 1 (CRF1) antagonism, but exacerbated by anxiogenic treatment, like antagonism of α2-adrenoreceptors. What is more, the anxiolytic CRF1 and anxiogenic α2-adrenoreceptor antagonists also modify behavioral phenotypes, with CRF1 antagonism allowing escape by previously submissive animals, and α2-adrenoreceptor antagonism hindering escape in mice that previously engaged in it. Gene expression of NPS and brain-derived neurotrophic factor (BDNF) in the central amygdala (CeA), as well as corticosterone secretion, increased concomitantly with the escalating anxious content of the mouse-specific anxiety continuum. The general trend of CeA NPS and BDNF expression suggested that NPS production was promoted by increasing anxiousness, and that BDNF synthesis was associated with learning about ever-more anxious conditions. The intensity gradient for anxious behavior resulting from varying contextual conditions may yield an improved conceptualization of the complexity of mechanisms producing the natural continuum of human anxious conditions, and potential therapies that arise therefrom. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Low intensity microwave radiation induced oxidative stress, inflammatory response and DNA damage in rat brain.

    Science.gov (United States)

    Megha, Kanu; Deshmukh, Pravin Suryakantrao; Banerjee, Basu Dev; Tripathi, Ashok Kumar; Ahmed, Rafat; Abegaonkar, Mahesh Pandurang

    2015-12-01

    Over the past decade people have been constantly exposed to microwave radiation mainly from wireless communication devices used in day to day life. Therefore, the concerns over potential adverse effects of microwave radiation on human health are increasing. Until now no study has been proposed to investigate the underlying causes of genotoxic effects induced by low intensity microwave exposure. Thus, the present study was undertaken to determine the influence of low intensity microwave radiation on oxidative stress, inflammatory response and DNA damage in rat brain. The study was carried out on 24 male Fischer 344 rats, randomly divided into four groups (n=6 in each group): group I consisted of sham exposed (control) rats, group II-IV consisted of rats exposed to microwave radiation at frequencies 900, 1800 and 2450 MHz, specific absorption rates (SARs) 0.59, 0.58 and 0.66 mW/kg, respectively in gigahertz transverse electromagnetic (GTEM) cell for 60 days (2h/day, 5 days/week). Rats were sacrificed and decapitated to isolate hippocampus at the end of the exposure duration. Low intensity microwave exposure resulted in a frequency dependent significant increase in oxidative stress markers viz. malondialdehyde (MDA), protein carbonyl (PCO) and catalase (CAT) in microwave exposed groups in comparison to sham exposed group (pmicrowave exposed groups (pmicrowave exposed animal (pmicrowave exposed groups as compared to their corresponding values in sham exposed group (pmicrowave radiation induces oxidative stress, inflammatory response and DNA damage in brain by exerting a frequency dependent effect. The study also indicates that increased oxidative stress and inflammatory response might be the factors involved in DNA damage following low intensity microwave exposure. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Oxidative stress and antioxidant responses to progressive resistance exercise intensity in trained and untrained males

    OpenAIRE

    H Çakır-Atabek; F Özdemir; R Çolak

    2015-01-01

    The relationship between oxidative stress and some exercise components of resistance exercise (e.g. intensity, exercise volume) has not been clearly defined. Additionally, the oxidative stress markers may respond differently in various conditions. This study aims to determine the effects of progressive intensity of resistance exercise (RE) on oxidative stress and antioxidants in trained and untrained men, and also to investigate the possible threshold intensity required to evoke oxidative str...

  17. The relation between intensity and complexity of coronary artery lesion and oxidative stress in patients with acute coronary syndrome.

    Science.gov (United States)

    Turan, Turhan; Menteşe, Ümit; Ağaç, Mustafa Tarık; Akyüz, Ali Rıza; Kul, Selim; Aykan, Ahmet Çağrı; Bektaş, Hüseyin; Korkmaz, Levent; Öztaş Menteşe, Seda; Dursun, İhsan; Çelik, Şükrü

    2015-10-01

    Oxidative stress plays a major role in the development of atherosclerosis. However, the relationship between oxidative stress and complexity and intensity of coronary artery disease is less clear. The aim of this study is to assess the relationship between oxidative stress markers and the complexity and intensity of coronary artery disease in patients with acute coronary syndrome (ACS). Sixty-seven consecutive patients with an early phase of ACS (=22). Likewise patients were divided into two CAD severity groups according to the median Gensini score of 64: less intensive CAD with Gensini score (=64. Blood samples were taken in 1 hour within administration in order to measure total oxidative status (TOS) and total antioxidant capacity (TAC) levels determined by Erel method. Oxidative stress index (OSI) was calculated by TOS /TAC. There was no significant difference between the two SYNTAX groups for oxidative stress markers. Median TOS and OSI values were significantly high in the intensive CAD group (p=0.005, p=0.04, respectively). The Gensini score was positively correlated with TOS and OSI (p=0.003, p=0.02, respectively). Oxidative stress markers may be considered supportive laboratory parameters related to CAD intensity but not complexity in ACS patients.

  18. The physical interpretation of the threshold-stress intensity range during fatigue loading

    International Nuclear Information System (INIS)

    Marci, G.; Bazant, E.

    1977-01-01

    Based on the experimental results, the threshold-stress intensity range is given the physical interpretation that it characterizes a range of effective tensile stresses which need to be exceeded during a loading cycle for stage II fatigue crack growth to occur. The threshold stress intensity range is independent from its relative position in the range of effective tensile stress, has always the same magnitude and, furthermore, is independent of the Ksub(Imax) which produced the active plastic zone. The experimental results available from previous threshold stress intensity determinations are in good agreement with the concept developed. (orig.) [de

  19. Stress-intensity factors for cracks emanating from the loaded fastener hole

    Science.gov (United States)

    Shivakumar, V.; Hsu, Y. C.

    1977-01-01

    Using a series approach and the Muskhelishvili formulation in the two-dimensional theory of elasticity, stress-intensity factors K are derived for problems in which cracks emanate radially from the boundary of an arbitrarily loaded internal circular hole in an infinite plate. Numerical values are obtained for K(I) and K(II) for radial cracks from a hole containing a loose-fitted pin or rivet that is pulled perpendicular to the crack direction in the plane of the plate. The method is a general one for determining K for a set of symmetrically emanating radial cracks for a variety of concentrated or distributed tractions on the circular hole.

  20. [Post-traumatic stress disorder-related to intensive care stay: influence of sedation practices].

    Science.gov (United States)

    Bauerheim, Nadège; Masseret, Elodie; Mercier, Emmanuelle; Dequin, Pierre-François; El-Hage, Wissam

    2013-03-01

    The stay in intensive care unit can be potentially traumatic at the origin of post-traumatic stress symptoms. The severity of post-traumatic stress symptoms is linked to the intensity and the type of traumatic memories of the intensive care stay. Sedatives and analgesics given to ventilated patients in intensive care influence the traumatic memory. The level, the duration and the type of sedation-analgesia protocol are risk factors of post-traumatic stress symptoms. Links between sedation, dissociative symptoms, delirium and post-traumatic stress symptoms are documented. Environmental and pharmacological measures are to be considered to reduce the traumatic potential risk of the intensive care. Intensive care caregivers, liaison-psychiatrist and general practitioner have each a specific role to play in the screening of the post-traumatic stress symptoms. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  1. Stress intensity factors and weight functions for cracks in front of notches

    International Nuclear Information System (INIS)

    Fett, T.

    1993-12-01

    The knowledge of stress intensity factors for cracks at notch roots is important for the fracture mechanical treatment of real components. Stress intensity factor solutions are available only for special notches and externally applied loads. For the treatment of more complex loadings as thermal stresses near the notch root the weight function is needed in addition. In the first part of this report weight functions for cracks in front of internal notches are derived from stress intensity factor solutions under external loading available in the literature. The second part deals with cracks in front of edge notches. Limit cases of stress intensity factors are derived which allow to estimate stress intensity factors for cracks in front of internal elliptical notches with arbitrary aspect ratio of the ellipse and for external notches. (orig.) [de

  2. Stress intensity factors of corner cracks in two nozzle-cylinder intersections

    International Nuclear Information System (INIS)

    Kobayashi, A.S.; Polvanich, N.; Emery, A.F.; Love, W.J.

    1977-01-01

    In a recent paper, the authors presented the stress-intensity-magnification factors of a quarter-elliptical surface crack in a quarter-infinite solid and a circular crack approaching a reentry corner in a three-quarter infinite solid. These stress-intensity-magnification factors were used together with a curvature-correction factor to estimate the stress-intensity factor of a corner crack at a nozzle-cylinder intersection. Through appropriate superposition of the above stress-intensity-magnification factors, stress-intensity factors for hypothetical corner cracks at a nozzle-cylinder intersection subjected to internal pressure and transient thermal-stress loadings can be obtained. A description of a computer code based on this procedure as well as its applications in analyzing two corner-crack problems at a nozzle-cylinder intersection are discussed in this paper

  3. Stress intensity factors of corner cracks in two nozzle-cylinder interactions

    International Nuclear Information System (INIS)

    Kobayashi, A.S.; Polvanich, N.; Emery, A.F.; Love, W.J.

    1977-01-01

    In a recent paper, the authors presented the stress-intensity-magnification factors of a quarter-elliptical surface crack in a quarter-infinite solid and a circular crack approaching a reentry corner in a three-quarter infinite solid. These stress-intensity-magnification factors were used together with a curvature-correction factor to estimate the stress-intensity factor of a corner crack at a nozzle-cylinder interaction. Through appropriate superposition of the above stress-intensity-magnification factors, stress-intensity factors for hypothetical corner cracks at a nozzle-cylinder intersection subjected to internal pressure and transient thermal-stress loadings can be obtained. A description of a computer code based on this procedure as well as its applications in analyzing two corner-crack probems at a nozzle-cylinder intersection are discussed in this paper. (Auth.)

  4. h-Adaptive Mesh Generation using Electric Field Intensity Value as a Criterion (in Japanese)

    OpenAIRE

    Toyonaga, Kiyomi; Cingoski, Vlatko; Kaneda, Kazufumi; Yamashita, Hideo

    1994-01-01

    Finite mesh divisions are essential to obtain accurate solution of two dimensional electric field analysis. It requires the technical knowledge to generate a suitable fine mesh divisions. In electric field problem, analysts are usually interested in the electric field intensity and its distribution. In order to obtain electric field intensity with high-accuracy, we have developed and adaptive mesh generator using electric field intensity value as a criterion.

  5. Transient Stress Intensity Factors of Functionally Graded Hollow Cylinders with Internal Circumferential Cracks

    Directory of Open Access Journals (Sweden)

    Iman Eshraghi

    Full Text Available Abstract In this paper, transient thermomechanical stress intensity factors for functionally graded cylinders with complete internal circumferential cracks are obtained using the weight function method. The finite difference method is used to calculate the time dependent temperature distribution and thermal stresses along the cylinder thickness. Furthermore, finite element analysis is performed to determine the weight function coefficients and to investigate the accuracy of the predicted stress intensity factors from the weight functions. Variation of the stress intensity factors with time and effects of the material gradation on the results are investigated, as well. It is shown that the proposed technique can be used to accurately predict transient thermomechanical stress intensity factors for functionally graded cylinders with arbitrary material gradation.

  6. Behavioral Predictors of Acute Stress Symptoms During Intense Military Training

    Science.gov (United States)

    2009-06-01

    the Ways of Coping Scale ( Folkman & Lazarus , 1988). During survival training, the Clinician- Administered Dissociative States Scale (Bremner et al...Published on behalf of the International Society for Traumatic Stress Studies. Acute Stress Symptoms 217 Folkman , S., & Lazarus , R. (1988). Manual...and performance in sport (pp. 17–42). Chichester, UK: Wiley. Lazarus , R. S. (2000). Cognitive-motivational-relational theory of emotion. In Y . Hanin

  7. Stress intensity factor analyses of surface cracks in three-dimensional structures

    International Nuclear Information System (INIS)

    Miyazaki, Noriyuki; Shibata, Katsuyuki; Watanabe, Takayuki; Tagata, Kazunori.

    1983-11-01

    The stress intensity factor analyses of surface cracks in various three-dimensional structures were performed using the finite element computer program EPAS-J1. The results obtained by EPAS-J1 were compared with other finite element solutions or results obtained by the simplified estimation methods. Among the simplified estimation methods, the equations proposed by Newman and Raju give the distributions of the stress intensity factor along a crack front, which were compared with the result obtained by EPAS-J1. It was confirmed by comparing the results that EPAS-J1 gives reasonable stress intensity factors of surface cracks in three-dimensional structures. (author)

  8. Stress-intensity factor equations for cracks in three-dimensional finite bodies

    Science.gov (United States)

    Newman, J. C., Jr.; Raju, I. S.

    1981-01-01

    Empirical stress intensity factor equations are presented for embedded elliptical cracks, semi-elliptical surface cracks, quarter-elliptical corner cracks, semi-elliptical surface cracks at a hole, and quarter-elliptical corner cracks at a hole in finite plates. The plates were subjected to remote tensile loading. Equations give stress intensity factors as a function of parametric angle, crack depth, crack length, plate thickness, and where applicable, hole radius. The stress intensity factors used to develop the equations were obtained from three dimensional finite element analyses of these crack configurations.

  9. Numerical evaluation of stress intensity factor for vessel and pipe subjected to thermal shock

    International Nuclear Information System (INIS)

    Kim, Y.W.; Lee, H.Y.; Yoo, B.

    1994-01-01

    The thermal weight function method and the finite element method were employed in the numerical computation of the stress intensity factor for a cracked vessel and the cracked pipe subjected to thermal shock. A wall subjected to thermal shock was analyzed, and it has been shown that the effect of thermal shock on the stress intensity factor is dominant for the crack with small crack length to thickness ratio. Convection at the crack face had an influence on the stress intensity factor in the early stage of thermal shock. (Author)

  10. Calculation of mixed mode stress intensity factors using an alternating method

    International Nuclear Information System (INIS)

    Sakai, Takayuki

    1999-01-01

    In this study, mixed mode stress intensity factors (K I and K II ) of a square plate with a notch were calculated using a finite element alternating method. The obtained results were compared with the ones by a finite element method, and it was shown that the finite element alternating method can accurately estimate mixed mode stress intensity factors. Then, using this finite element alternating method, mixed mode stress intensity factors were calculated as changing the size and position of the notch, and its simplified equations were proposed. (author)

  11. INFLUENCE OF MACHINING TECHNOLOGIES ON VALUES OF RESIDUAL STRESSES OF OXIDE CUTTING CERAMICS

    Directory of Open Access Journals (Sweden)

    Jakub Němeček

    2017-07-01

    Full Text Available Currently, the intensive development of engineering ceramic and effort to replace sintered carbides as cutting materials are in progress. With the development of the sintering technology it is now possible to produce compact ceramic cutting samples with very good mechanical properties. The advantage of these materials is their easy accessibility and low purchase price. In this work, the influence of the finishing machine technology on the values of surface residual stresses of cutting ceramic samples Al2O3+TiC were studying. The samples were supplied by Moscow State University of Technology STANKIN. Measurements made in the X-ray diffraction laboratory at the Department of solid state engineering were performed for both the phases. The influence of the parameters of machining to residual stresses was studied and the resulting values were compared with each other.

  12. Investigations on the influence of the stress state on fracture-mechanical values

    International Nuclear Information System (INIS)

    Schmidt, P.

    1979-01-01

    Fracture toughness obtained from specimen can be applied to construction elements only when the same stress state exists. In standardised fracture-mechanical tests plain strain is realised. Using the stress intensity factor, a critical crack length or a critical load can be obtained. Above these values a crack propagates in an unstable way. The specimen are tested under uni-axial load. In this paper investigations have been made whether a biaxial load increases the stress state over the plain strain and whether consequently a decrease of the critical fracture toughness and a shift of the temperatures Tsub(g)sub(y) and Tsub(s) results which characterise the fracture behaviour of steel. In order to answer these questions the tests were made which induced due to their geometry an additional nominal stress parallel to the crack front in spite of uni-axial loading. The results were compared with those from specimen without an additional nominal stress and having in their cross section under same test conditions nearly the same plain strain. The fracture toughness of both specimen types were compared at temperatures between 142 K and 252 K and correlated to other material-characterising values. The tests were completed by stress analysis and by comparing the crack opening displacement. Due to the additional stress, Tsub(g)sub(y) was found to be 20 K higher than for the reference specimen. The fracture toughness decreases significantly in certain temperature ranges. The plastic stress concentration factor was comperatively higher and the remaining plastic crack opening decreases up to 25%. (orig.) [de

  13. Stress ulcer prophylaxis in the intensive care unit

    DEFF Research Database (Denmark)

    Krag, Mette; Perner, Anders; Møller, Morten H

    2016-01-01

    PURPOSE OF REVIEW: Stress ulcer prophylaxis (SUP) is considered standard of care in the majority of critically ill patients in the ICU. In this review, we will present the current evidence for the use of SUP in ICU patients, including data on the prevalence of gastrointestinal bleeding and the ba......PURPOSE OF REVIEW: Stress ulcer prophylaxis (SUP) is considered standard of care in the majority of critically ill patients in the ICU. In this review, we will present the current evidence for the use of SUP in ICU patients, including data on the prevalence of gastrointestinal bleeding...

  14. Dynamic stress intensity factors for a longitudinal semi-elliptical ...

    African Journals Online (AJOL)

    elliptical crack in a thick-walled cylinder subjected to transient dynamic stresses. First, the problem of dynamic elasticity in a thick-walled cylinder is solved analytically using the finite Hankel transform. Transient pressure is assumed to act on ...

  15. Symptoms of Posttraumatic Stress after Intensive Care Delirium

    DEFF Research Database (Denmark)

    Svenningsen, Helle; Egerod, Ingrid; Christensen, Doris

    2015-01-01

    Introduction. Long-term psychological consequences of critical illness are receiving more attention in recent years. The aim of our study was to assess the correlation of ICU-delirium and symptoms of posttraumatic stress disorder (PTSD) anxiety and depression after ICU-discharge in a Danish cohort...

  16. Social stress induces high intensity sleep in rats

    NARCIS (Netherlands)

    Meerlo, P; Pragt, Bertrand J.; Daan, S

    1997-01-01

    We studied the effect of social stress on sleep electroencephalogram (EEG) in rats. Animals were subjected to a single social defeat by introducing them in the cage of an aggressive male conspecific for 1 h. The animals responded to the social conflict by a sharp increase in EEG slow-wave activity

  17. Weight functions for the determination of stress intensity factor and T-stress for edge-cracked plates with built-in ends

    International Nuclear Information System (INIS)

    Li, J.; Wang, X.; Tan, C.L.

    2004-01-01

    This paper presents the weight functions for the determination of the stress intensity factor and T-stress solutions for edge-cracked plates with built-in ends under complex stress distributions. First, a compliance analysis approach is used to calculate stress intensity factor and T-stress for edge cracks in finite width plates with built-in ends with uniform or linear stress distributions acting on the crack face. The results serve as the reference solutions for the next step in which the approaches of deriving weight functions from reference stress intensity factor and T-stress solutions developed for stress boundary conditions are extended to obtain the corresponding weight functions for edge-cracked plates with built-in ends. Finite element analysis is conducted to validate the derived solutions. The weight functions derived are suitable for obtaining stress intensity factors and T-stress solutions under any complex stress field

  18. Usefulness of creep work-time relation for determining stress intensity limit of high-temperature components

    International Nuclear Information System (INIS)

    Kim, Woo Gon; Ryu, Woo Seog; Lee, Kyung Yong

    2003-01-01

    In order to determine creep stress intensity limit of high-temperature components, the usefulness of the creep work and time equation, defined as W c t p = B (where W c = σ ε is the total creep work done during creep, and p and B are constants), was investigated using the experimental data. For this purpose, the creep tests for generating 1.0% strain for commercial type 316 stainless steel were conducted with different stresses; 160 MPa, 150 MPa, 145 MPa, 140 MPa and 135 MPa at 593 .deg. C. The plots of log W c - log t showed a good linear relation up to 10 5 hr, and the results of the creep work-time relation for p, B and stress intensity values showed good agreement to those of Isochronous Stress-Strain Curves (ISSC) presented in ASME BPV NH. The relation can be simply obtained with only several short-term 1% strain data without ISSC which can be obtained by long-term creep data. Particularly, this relation is useful in estimating stress intensity limit for new and emerging class of high-temperature creeping materials

  19. Neonatal Intensive Care Unit Nurses Working in an Open Ward: Stress and Work Satisfaction.

    Science.gov (United States)

    Lavoie-Tremblay, Mélanie; Feeley, Nancy; Lavigne, Geneviève L; Genest, Christine; Robins, Stéphanie; Fréchette, Julie

    2016-01-01

    There is some research on the impact of open-ward unit design on the health of babies and the stress experienced by parents and nurses in neonatal intensive care units. However, few studies have explored the factors associated with nurse stress and work satisfaction among nurses practicing in open-ward neonatal intensive care units. The purpose of this study was to examine what factors are associated with nurse stress and work satisfaction among nurses practicing in an open-ward neonatal intensive care unit. A cross-sectional correlational design was used in this study. Participants were nurses employed in a 34-bed open-ward neonatal intensive care unit in a major university-affiliated hospital in Montréal, Quebec, Canada. A total of 94 nurses were eligible, and 86 completed questionnaires (91% response rate). Descriptive statistics were computed to describe the participants' characteristics. To identify factors associated with nurse stress and work satisfaction, correlational analysis and multiple regression analyses were performed with the Nurse Stress Scale and the Global Work Satisfaction scores as the dependent variables. Different factors predict neonatal intensive care unit nurses' stress and job satisfaction, including support, family-centered care, performance obstacles, work schedule, education, and employment status. In order to provide neonatal intensive care units nurses with a supportive environment, managers can provide direct social support to nurses and influence the culture around teamwork.

  20. Eliciting the Intension of Drug Value Sets – Principles and Quality Assurance Applications

    Science.gov (United States)

    Bahr, Nathan J.; Nelson, Scott D.; Winnenburg, Rainer; Bodenreider, Olivier

    2018-01-01

    Value sets (VSs) used in electronic clinical quality measures are lists of codes from standard terminologies (“extensional” VSs), whose purpose (“intension”) is not always explicitly stated. We elicited the intension for the 09/01/2014 release of extensional medication value sets by comparison to drug classes from the October 2014 release of RxClass. Value sets matched drug classes if they shared common ingredients, as evidenced by Jaccard similarity score. We elicited the intension of 80 extensional value sets. The average Jaccard similarity was 0.65 for single classes and 0.80 for combination classes, with 34% (27/80) of the value sets having high similarity scores. Manual review by a pharmacist indicated 51% (41/80) of the drug classes selected as the best mapping for a value set matched the intension reflected in that value set name. This approach has the potential for facilitating the development and maintenance of medication value sets. PMID:29295218

  1. Oxidative stress and antioxidant responses to progressive resistance exercise intensity in trained and untrained males

    Directory of Open Access Journals (Sweden)

    H Çakır-Atabek

    2015-11-01

    Full Text Available The relationship between oxidative stress and some exercise components of resistance exercise (e.g. intensity, exercise volume has not been clearly defined. Additionally, the oxidative stress markers may respond differently in various conditions. This study aims to determine the effects of progressive intensity of resistance exercise (RE on oxidative stress and antioxidants in trained and untrained men, and also to investigate the possible threshold intensity required to evoke oxidative stress. RE trained (N=8 and untrained (N=8 men performed the leg extension RE at progressive intensities standardized for total volume: 1x17 reps at 50% of one-repetition maximum (1RM; 1x14 reps at 60% of 1RM; 1x12 reps at 70% of 1RM; 2x5 reps at 80% of 1RM; and 3x3 reps at 90% of 1RM. Blood samples were drawn before (PRE and immediately after each intensity, and after 30 minutes, 60 minutes and 24 hours following the RE. Lipid-hydroperoxide (LHP significantly increased during the test and then decreased during the recovery in both groups (p0.05. Standardized volume of RE increased oxidative stress responses. Our study suggests that lower intensity (50% is enough to increase LHP, whereas higher intensity (more than 80% is required to evoke protein oxidation.

  2. Quantitative stress measurement of elastic deformation using mechanoluminescent sensor: An intensity ratio model

    Science.gov (United States)

    Cai, Tao; Guo, Songtao; Li, Yongzeng; Peng, Di; Zhao, Xiaofeng; Liu, Yingzheng

    2018-04-01

    The mechanoluminescent (ML) sensor is a newly developed non-invasive technique for stress/strain measurement. However, its application has been mostly restricted to qualitative measurement due to the lack of a well-defined relationship between ML intensity and stress. To achieve accurate stress measurement, an intensity ratio model was proposed in this study to establish a quantitative relationship between the stress condition and its ML intensity in elastic deformation. To verify the proposed model, experiments were carried out on a ML measurement system using resin samples mixed with the sensor material SrAl2O4:Eu2+, Dy3+. The ML intensity ratio was found to be dependent on the applied stress and strain rate, and the relationship acquired from the experimental results agreed well with the proposed model. The current study provided a physical explanation for the relationship between ML intensity and its stress condition. The proposed model was applicable in various SrAl2O4:Eu2+, Dy3+-based ML measurement in elastic deformation, and could provide a useful reference for quantitative stress measurement using the ML sensor in general.

  3. Characterisation of Intensity Values on Terrestrial Laser Scanning for Recording Enhancement

    Science.gov (United States)

    Balaguer-Puig, M.; Molada-Tebar, A.; Marqués-Mateu, A.; Lerma, J. L.

    2017-08-01

    Mapping surveys based on terrestrial laser scanning (TLS) are common nowadays for different purposes such as documentation of cultural heritage assets. The chance to extract relevant information from TLS surveys depends not only on the fast acquisition of XYZ coordinates, but also on the meaningful intensity values of the fired objects. TLS behaviour depends on several known factors such as distance, texture, roughness, colour and albedo. This paper seeks to find out the mathematical relationship between the TLS intensity values and the colorimetric data using a colour chart. In order to do so, objective colour specification based on well-known colour spaces is needed. The approach used here started with scanning a colour chart containing a number of colour patches with known chromatic and reflection characteristics. After several transformations, the results allowed us to characterise the intensity behaviour of a time-of-flight laser scanner. The characterisation of the intensity values are tested indoor on the colour chart and outdoor on an archaeological shelter. Promising results are obtained to enhance the behaviour of the intensity values coming from the TLS.

  4. An approach toward incorporation of global warming effects into Intensity-Duration-Frequency values

    Science.gov (United States)

    Kunkel, K.; Easterling, D. R.

    2017-12-01

    Rising global temperatures from increasing greenhouse gas concentrations will increase overall atmospheric water vapor concentrations. There is a high level of scientific confidence that this will increase the future intensity and frequency of extreme precipitation events, even in regions where overall precipitation may decrease. For control of runoff from extreme rainfall, infrastructure engineering utilizes design values of rainfall known as Intensity-Duration-Frequency (IDF) values. Use of the existing IDF values, which are based solely on historical climate records, is likely to lead to under-design of runoff control structures, and associated increased flood damages. However, future changes in IDF values are uncertain and probably regionally variable. Our paradigm is that changes in IDF values will result from changes in atmospheric capacity (water vapor concentrations) and opportunity (the number and intensity of heavy precipitation-producing storm systems). Relevant storm systems being investigated include extratropical cyclones and their associated fronts, tropical cyclones, and the North American Monsoon system. The overall approach involves developing IDF adjustment factors for changes in these components of the climate system. The adjustment factors have associated uncertainties, primarily from (1) uncertainties in the future pathway of greenhouse gas emissions and (2) variations among climate models in the sensitivity of the climate system to greenhouse gas concentration changes. In addition to meteorological considerations, the lifetime of projects designed using IDF values is an essential consideration because the IDF values may change substantially during that time. The initial results of this project will be discussed.

  5. Patient stress in intensive care: comparison between a coronary care unit and a general postoperative unit

    Science.gov (United States)

    Dias, Douglas de Sá; Resende, Mariane Vanessa; Diniz, Gisele do Carmo Leite Machado

    2015-01-01

    Objective To evaluate and compare stressors identified by patients of a coronary intensive care unit with those perceived by patients of a general postoperative intensive care unit. Methods This cross-sectional and descriptive study was conducted in the coronary intensive care and general postoperative intensive care units of a private hospital. In total, 60 patients participated in the study, 30 in each intensive care unit. The stressor scale was used in the intensive care units to identify the stressors. The mean score of each item of the scale was calculated followed by the total stress score. The differences between groups were considered significant when p < 0.05. Results The mean ages of patients were 55.63 ± 13.58 years in the coronary intensive care unit and 53.60 ± 17.47 years in the general postoperative intensive care unit. For patients in the coronary intensive care unit, the main stressors were “being in pain”, “being unable to fulfill family roles” and “being bored”. For patients in the general postoperative intensive care unit, the main stressors were “being in pain”, “being unable to fulfill family roles” and “not being able to communicate”. The mean total stress scores were 104.20 ± 30.95 in the coronary intensive care unit and 116.66 ± 23.72 (p = 0.085) in the general postoperative intensive care unit. When each stressor was compared separately, significant differences were noted only between three items. “Having nurses constantly doing things around your bed” was more stressful to the patients in the general postoperative intensive care unit than to those in the coronary intensive care unit (p = 0.013). Conversely, “hearing unfamiliar sounds and noises” and “hearing people talk about you” were the most stressful items for the patients in the coronary intensive care unit (p = 0.046 and 0.005, respectively). Conclusion The perception of major stressors and the total stress score were similar between patients

  6. [Stress level assessment of the nursing staff in the Intensive Care Unit of a university hospital].

    Science.gov (United States)

    Carrillo-García, C; Ríos-Rísquez, M I; Martínez-Hurtado, R; Noguera-Villaescusa, P

    2016-01-01

    The objective was to determine the work stress level among nursing staff in the Intensive Care Unit of a university hospital and to analyse its relationship with the various sociodemographic and working variables of the studied sample. A study was designed using a quantitative, descriptive and cross-sectional approach. The target population of the study was the nursing staff selected by non-random sampling. The instrument used was the Job Content Questionnaire. Data analysis was performed using SPSS 20. The mean, ranges and standard deviation for each of the variables were calculated. A bivariate analysis was also performed on the social and occupational variables of the sample. The participation rate was 80.90% (N=89). The mean of the Social support dimension was 3.13±0.397, for the Psychological demands at work dimension it was 3.10±0.384, with a mean of 2.96±0.436 being obtained for the Control over the work dimension. In the analysis of sociodemographic and work variables of the sample, only the professional category was significant, with nurses recording higher values in perception of job demands and control over their work compared to nursing assistants. In conclusion, there is a moderate perception of work stress in the analysed group of professionals. Among the sources of stress in the workplace was the low control in decision-making by practitioners, as well as the need to continually learn new things. On the other hand, the support received from colleagues is valued positively by the sample. Copyright © 2016 Elsevier España, S.L.U. y SEEIUC. All rights reserved.

  7. The Effects of Aromatherapy on Intensive Care Unit Patients’ Stress and Sleep Quality: A Nonrandomised Controlled Trial

    Directory of Open Access Journals (Sweden)

    Eun Hee Cho

    2017-01-01

    Full Text Available Background. Stress has both physiological and psychological effects and can negatively impact patients’ treatment and recovery. We examined whether the aromatherapy alleviated patients’ stress and improved their sleep quality and provided data that can be utilized in clinical settings. Methods. This was a nonrandomised controlled experimental study. Participants included lucid adult patients who were admitted to the intensive care unit and had spent more than two nights there. The experimental treatment required participants to engage in deep breathing with essential oils as part of the aromatherapy. The control group was instructed to go to sleep without receiving the lavender aroma oil. Results. The experimental group and control group showed a significant difference in perceived stress (F=60.11, p<.001, objective stress index (F=25.65, p<.001, systolic blood pressure (F=9.09, p<.001, diastolic blood pressure (F=2.47, p=.046, heart rate (F=5.71, p<.001, and sleep quality (F=109.46, p<.001. Conclusions. The results revealed that aromatherapy alleviated stress and improved sleep quality in intensive care unit patients after 2 days of the experimental treatment. These results demonstrate that aromatherapy affects stress and sleep quality, thus indicating its value in nursing interventions. This trial is registered with KCT0002344.

  8. The importance of physical activity and sleep for affect on stressful days: Two intensive longitudinal studies.

    Science.gov (United States)

    Flueckiger, Lavinia; Lieb, Roselind; Meyer, Andrea H; Witthauer, Cornelia; Mata, Jutta

    2016-06-01

    We investigated the potential stress-buffering effect of 3 health behaviors-physical activity, sleep quality, and snacking-on affect in the context of everyday life in young adults. In 2 intensive longitudinal studies with up to 65 assessment days over an entire academic year, students (Study 1, N = 292; Study 2, N = 304) reported stress intensity, sleep quality, physical activity, snacking, and positive and negative affect. Data were analyzed using multilevel regression analyses. Stress and positive affect were negatively associated; stress and negative affect were positively associated. The more physically active than usual a person was on a given day, the weaker the association between stress and positive affect (Study 1) and negative affect (Studies 1 and 2). The better than usual a person's sleep quality had been during the previous night, the weaker the association between stress and positive affect (Studies 1 and 2) and negative affect (Study 2). The association between daily stress and positive or negative affect did not differ as a function of daily snacking (Studies 1 and 2). On stressful days, increasing physical activity or ensuring high sleep quality may buffer adverse effects of stress on affect in young adults. These findings suggest potential targets for health-promotion and stress-prevention programs, which could help reduce the negative impact of stress in young adults. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  9. Study on applicability of stress intensity factor solutions for flaw evaluation

    International Nuclear Information System (INIS)

    Miura, Naoki; Nagai, Masaki; Takahashi, Yukio

    2014-01-01

    Stress intensity factor is the quantity which characterizes the singularity of the stress field near a crack tip in the scheme of the linear elastic fracture mechanics, and is used for fatigue and/or SCC crack propagation evaluation. Stress intensity factor depends on the shape and the size of cracked structures, and is frequently prepared as the tabulated correction factors which are the functions of crack depth ratio, aspect ratio, etc. Some stress intensity factor solutions have been included in the JSME rules on fitness-for-service for nuclear power plants. Many of them have been significantly revised on the latest (2012) version of the rules, however, the validation of the revised solutions was not adequate so far. In this study, the implication of the revision was investigated together with its technical basis. A comprehensive comparison was made between available solutions including the 2008 and 2012 version of the rules. It was ascertained that the solutions in the 2012 version provided stress intensity factors consistent with the previous version and the referential stress intensity factors. (author)

  10. Determination of Stress Intensity Factor K1 from Two Fringe Orders by Fringe Multiplication and Sharpening

    International Nuclear Information System (INIS)

    Chen, Lei; Baek, Tae Hyun

    2007-01-01

    Stress intensity factor is one of the most important parameters in fracture mechanics. Both the stress field distribution and the crack propagation are closely related to these parameters. Due to the complexity of actual engineering problems, it is difficult to calculate the stress intensity factor by theoretical formulation, so photoelasticity method is a good choice. In this paper, modified two parameter method is employed to calculate stress intensity factor for opening mode by using data from more than one photoelastic fringe loop. For getting accurate experiment results, the initial fringes are doubled and sharpened by digital image programs from the fringe patterns obtained by a CCD camera. Photoelastic results are compared with those obtained by the use of empirical equation and FEM. Good agreement shows that the methods utilized in experiments are considerably reliable. The photoelastic experiment can be used for bench mark in theoretical study and other experiments

  11. Loss of parental role as a cause of stress in the neonatal intensive care unit.

    Science.gov (United States)

    Bouet, Kary M; Claudio, Norma; Ramirez, Verónica; García-Fragoso, Lourdes

    2012-01-01

    Having a baby in the Neonatal Intensive Care Unit (NICU) is a major source of stress for parents. The barriers to parenting and reactions to the environment may negatively influence the parent-infant relationship. To identify NICU-related parental stress and associated factors. Parents (N = 156) of newborns admitted to NICU completed the Parental Stressor Scale. Most of the parents (46%) rated the experience to be extremely stressful. The principal cause of stress was the alteration in parental role and being separated from their baby. Stress was not associated to education, marital status, infants' birth weight, gestational age, congenital anomalies or if the parents expected the baby to be in the NICU. Identification of areas associated to higher levels of stress in parents may help the NICU staff to establish strategies to help parents cope with the stress caused by being unable to start their parenting role immediately after their babies' birth.

  12. Pain sensitivity mediates the relationship between stress and headache intensity in chronic tension-type headache.

    Science.gov (United States)

    Cathcart, Stuart; Bhullar, Navjot; Immink, Maarten; Della Vedova, Chris; Hayball, John

    2012-01-01

    A central model for chronic tension-type headache (CTH) posits that stress contributes to headache, in part, by aggravating existing hyperalgesia in CTH sufferers. The prediction from this model that pain sensitivity mediates the relationship between stress and headache activity has not yet been examined. To determine whether pain sensitivity mediates the relationship between stress and prospective headache activity in CTH sufferers. Self-reported stress, pain sensitivity and prospective headache activity were measured in 53 CTH sufferers recruited from the general population. Pain sensitivity was modelled as a mediator between stress and headache activity, and tested using a nonparametric bootstrap analysis. Pain sensitivity significantly mediated the relationship between stress and headache intensity. The results of the present study support the central model for CTH, which posits that stress contributes to headache, in part, by aggravating existing hyperalgesia in CTH sufferers. Implications for the mechanisms and treatment of CTH are discussed.

  13. World Best Practice Energy Intensity Values for SelectedIndustrial Sectors

    Energy Technology Data Exchange (ETDEWEB)

    Worrell, Ernst; Price, Lynn; Neelis, Maarten; Galitsky,Christina; Zhou, Nan

    2007-06-05

    "World best practice" energy intensity values, representingthe most energy-efficient processes that are in commercial use in atleast one location worldwide, are provided for the production of iron andsteel, aluminium, cement, pulp and paper, ammonia, and ethylene. Energyintensity is expressed in energy use per physical unit of output for eachof these commodities; most commonly these are expressed in metric tonnes(t). The energy intensity values are provided by major energy-consumingprocesses for each industrial sector to allow comparisons at the processlevel. Energy values are provided for final energy, defined as the energyused at the production facility as well as for primary energy, defined asthe energy used at the production facility as well as the energy used toproduce the electricity consumed at the facility. The "best practice"figures for energy consumption provided in this report should beconsidered as indicative, as these may depend strongly on the materialinputs.

  14. Simulation Analysis of the Mutual Influence of the Stress Intensity Factor on the Multiple Blisters Caused by Hydrogen Induced Damage

    Science.gov (United States)

    Ji, Congwei; Zhang, Shaojie; Wang, Hehui

    2018-03-01

    Hydrogen blisters are taken as the research object by using the finite element software ABAQUS. The stress intensity factors of blister cracks are numerically calculated at varying depths and different edge distances for established three-dimensional finite element models of single-blister and double-blisters, respectively. The mutual influence of the stress intensity factors of the multiple blisters is obtained. It shows that the blister crack is easier to expand when the crack is closer to inner wall of the cylinder. What’s more, the crack growth rate increases firstly and then decreases as the increasing of the distance between two blisters cracks. The investigated result is of great reference value for predicting the trend of blister crack growth.

  15. Symptoms of Posttraumatic Stress after Intensive Care Delirium

    Directory of Open Access Journals (Sweden)

    Helle Svenningsen

    2015-01-01

    Full Text Available Introduction. Long-term psychological consequences of critical illness are receiving more attention in recent years. The aim of our study was to assess the correlation of ICU-delirium and symptoms of posttraumatic stress disorder (PTSD anxiety and depression after ICU-discharge in a Danish cohort. Methods. A prospective observational cohort study assessing the incidence of delirium in the ICU. Psychometrics were screened by validated tools in structured telephone interviews after 2 months (n=297 and 6 months (n=248 after ICU-discharge. Results. Delirium was detected in 54% of patients in the ICU and symptoms of PTSD in 8% (2 months and 6% (6 months after ICU-discharge. Recall of ICU stay was present in 93%. Associations between ICU-delirium and post-discharge PTSD-symptoms were weak and insignificant. Memories of delusions were significantly associated with anxiety after two months. Remaining associations between types of ICU-memories and prevalence of post-discharge symptoms of PTSD, anxiety, and depression were insignificant after adjusting for age. Incidence of ICU-delirium was unaffected by preadmission use of psychotropic drugs. Prevalence of PTSD-symptoms was unaffected by use of antipsychotics and sedation in the ICU. Conclusion. ICU-delirium did not increase the risk of PTSD-symptoms at 2 and 6 months after ICU discharge.

  16. Symptoms of Posttraumatic Stress after Intensive Care Delirium.

    Science.gov (United States)

    Svenningsen, Helle; Egerod, Ingrid; Christensen, Doris; Tønnesen, Else Kirstine; Frydenberg, Morten; Videbech, Poul

    2015-01-01

    Long-term psychological consequences of critical illness are receiving more attention in recent years. The aim of our study was to assess the correlation of ICU-delirium and symptoms of posttraumatic stress disorder (PTSD) anxiety and depression after ICU-discharge in a Danish cohort. A prospective observational cohort study assessing the incidence of delirium in the ICU. Psychometrics were screened by validated tools in structured telephone interviews after 2 months (n = 297) and 6 months (n = 248) after ICU-discharge. Delirium was detected in 54% of patients in the ICU and symptoms of PTSD in 8% (2 months) and 6% (6 months) after ICU-discharge. Recall of ICU stay was present in 93%. Associations between ICU-delirium and post-discharge PTSD-symptoms were weak and insignificant. Memories of delusions were significantly associated with anxiety after two months. Remaining associations between types of ICU-memories and prevalence of post-discharge symptoms of PTSD, anxiety, and depression were insignificant after adjusting for age. Incidence of ICU-delirium was unaffected by preadmission use of psychotropic drugs. Prevalence of PTSD-symptoms was unaffected by use of antipsychotics and sedation in the ICU. ICU-delirium did not increase the risk of PTSD-symptoms at 2 and 6 months after ICU discharge.

  17. The Effects of Aromatherapy on Intensive Care Unit Patients' Stress and Sleep Quality: A Nonrandomised Controlled Trial

    Science.gov (United States)

    Cho, Eun Hee; Lee, Mi-Young

    2017-01-01

    Background Stress has both physiological and psychological effects and can negatively impact patients' treatment and recovery. We examined whether the aromatherapy alleviated patients' stress and improved their sleep quality and provided data that can be utilized in clinical settings. Methods This was a nonrandomised controlled experimental study. Participants included lucid adult patients who were admitted to the intensive care unit and had spent more than two nights there. The experimental treatment required participants to engage in deep breathing with essential oils as part of the aromatherapy. The control group was instructed to go to sleep without receiving the lavender aroma oil. Results The experimental group and control group showed a significant difference in perceived stress (F = 60.11, p aromatherapy alleviated stress and improved sleep quality in intensive care unit patients after 2 days of the experimental treatment. These results demonstrate that aromatherapy affects stress and sleep quality, thus indicating its value in nursing interventions. This trial is registered with KCT0002344. PMID:29375641

  18. Influence of laboratory annealing on tensile properties and design stress intensity limits for Type 304 stainless steel

    International Nuclear Information System (INIS)

    Sikka, V.K.; Booker, M.K.

    1977-01-01

    The influence of reannealing (laboratory annealing) on yield and ultimate tensile strength values of 19 heats of type 304 stainless steel was determined. Most heats were reannealed at 1065 0 C for 0.5 hr. The reannealed properties were used to determine the influence of reannealing on time-independent design stress intensity limits (S/sub m/). The major findings are as follows: 1. Reannealing lowered the 0.2 percent yield strength versus temperature curve by approximately 42 MPa over the range from room temperature to 649 0 C. 2. The estimated S/sub m/ values for reannealed material were 24 to 28 MPa lower than the current code values. 3. Reannealing appears to influence the S/sub m/ value sufficiently to warrant the consideration of separate values of S/sub m/ in Sect. III of the Boiler and Pressure Vessel Code and Code Case 1592 for ''as-received'' and reannealed material

  19. Value of dobutamine stress tissue Doppler in evaluation of LV ...

    African Journals Online (AJOL)

    Shaimaa Ahmed Mostafa

    2014-12-12

    Dec 12, 2014 ... Prediction of functional recovery, based on the detection of contractile reserve with dobutamine stress echocardiography. (DSE), includes myocardial perfusion imaging, metabolic imaging with conventional scintigraphy and positron emission tomography (PET).12. Dobutamine stress echocardiography is ...

  20. Gradually Increased Training Intensity Benefits Rehabilitation Outcome after Stroke by BDNF Upregulation and Stress Suppression

    Directory of Open Access Journals (Sweden)

    Jing Sun

    2014-01-01

    Full Text Available Physical training is necessary for effective rehabilitation in the early poststroke period. Animal studies commonly use fixed training intensity throughout rehabilitation and without adapting it to the animals' recovered motor ability. This study investigated the correlation between training intensity and rehabilitation efficacy by using a focal ischemic stroke rat model. Eighty male Sprague-Dawley rats were induced with middle cerebral artery occlusion/reperfusion surgery. Sixty rats with successful stroke were then randomly assigned into four groups: control (CG, n=15, low intensity (LG, n=15, gradually increased intensity (GIG, n=15, and high intensity (HG, n=15. Behavioral tests were conducted daily to evaluate motor function recovery. Stress level and neural recovery were evaluated via plasma corticosterone and brain-derived neurotrophic factor (BDNF concentration, respectively. GIG rats significantly (P<0.05 recovered motor function and produced higher hippocampal BDNF (112.87 ± 25.18 ng/g. GIG and LG rats exhibited similar stress levels (540.63 ± 117.40 nM/L and 508.07 ± 161.30 nM/L, resp., which were significantly lower (P<0.05 than that (716.90 ± 156.48 nM/L of HG rats. Training with gradually increased intensity achieved better recovery with lower stress. Our observations indicate that a training protocol that includes gradually increasing training intensity should be considered in both animal and clinical studies for better stroke recovery.

  1. Analysis of stress intensity factors for a new mechanical corrosion specimen

    International Nuclear Information System (INIS)

    Rassineux, B.; Crouzet, D.; Le Hong, S.

    1996-03-01

    Electricite de France is conducting a research program to determine corrosion cracking rates in the steam generators Alloy 600 tubes of the primary system. The objective is to correlate the cracking rates with the specimen stress intensity factor K I . One of the samples selected for the purpose of this study is the longitudinal notched specimen TEL (TEL: ''Tubulaire a Entailles Longitudinales''). This paper presents the analysis of the stress intensity factor and its experimental validation. The stress intensity factor has been evaluated for different loads using 3D finite element calculations with the Hellen-Parks and G(θ) methods. Both crack initiation and propagation are considered. As an assessment of the method, the numerical simulations are in good agreement with the fatigue crack growth rates measured experimentally for TEL and compact tension (CT) specimens. (authors). 8 refs., 6 figs., 2 tabs

  2. Mid-thickness studies of the stress intensity factor in the bulk of bainitic steel

    Directory of Open Access Journals (Sweden)

    P. Lopez-Crespo

    2017-07-01

    Full Text Available The current work aims at estimating the stress intensity factor deep inside the bulk from elastic strain data measured by synchrotron X-ray diffraction. Key features affecting the evaluation of the stress intensity factor are the number of terms in the analytical model describing the crack tip field, the extension and position of the area of interest of the experimental data, the effect of the experimental data collected within the plastic zone and the number of elastic strain data points used. Here a parametric study of these features is presented in terms of their influence for the stress intensity factor determination. It was found that 3 or 4 terms in Williams’ expansion is often sufficient; the data should be collected from across the full range of angles around the crack tip; and the number of points/number of terms should be greater than 40.

  3. Challenges in participatory primary stress management interventions in knowledge intensive SMEs

    DEFF Research Database (Denmark)

    Gish, Liv; Ipsen, Christine

    2013-01-01

    relevant change processes. This paper presents the outline of our research and development project on participatory primary stress management interventions in knowledge intensive SMEs, as well as the preliminary results and related implications. The research and development project is conducted in order...... to develop an operational model which SMEs can use when they want to initiate participatory primary stress management interventions in their company. The development project builds on a process model for participatory primary interventions in larger knowledge intensive companies and the premises behind......While knowledge intensive SMEs have recognized the need for change with respect to productivity and wellbeing, and to some extend have access to tools and methods for enabling this, they still lack process competences and are uncertain about how to approach primary stress interventions and initiate...

  4. AIP1OGREN: Aerosol Observing Station Intensive Properties Value-Added Product

    Energy Technology Data Exchange (ETDEWEB)

    Koontz, Annette [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Flynn, Connor [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-09-15

    The aip1ogren value-added product (VAP) computes several aerosol intensive properties. It requires as input calibrated, corrected, aerosol extensive properties (scattering and absorption coefficients, primarily) from the Aerosol Observing Station (AOS). Aerosol extensive properties depend on both the nature of the aerosol and the amount of the aerosol. We compute several properties as relationships between the various extensive properties. These intensive properties are independent of aerosol amount and instead relate to intrinsic properties of the aerosol itself. Along with the original extensive properties we report aerosol single-scattering albedo, hemispheric backscatter fraction, asymmetry parameter, and Ångström exponent for scattering and absorption with one-minute averaging. An hourly averaged file is produced from the 1-minute files that includes all extensive and intensive properties as well as submicron scattering and submicron absorption fractions. Finally, in both the minutely and hourly files the aerosol radiative forcing efficiency is provided.

  5. Prognostic Value of Quantitative Stress Perfusion Cardiac Magnetic Resonance.

    Science.gov (United States)

    Sammut, Eva C; Villa, Adriana D M; Di Giovine, Gabriella; Dancy, Luke; Bosio, Filippo; Gibbs, Thomas; Jeyabraba, Swarna; Schwenke, Susanne; Williams, Steven E; Marber, Michael; Alfakih, Khaled; Ismail, Tevfik F; Razavi, Reza; Chiribiri, Amedeo

    2018-05-01

    This study sought to evaluate the prognostic usefulness of visual and quantitative perfusion cardiac magnetic resonance (CMR) ischemic burden in an unselected group of patients and to assess the validity of consensus-based ischemic burden thresholds extrapolated from nuclear studies. There are limited data on the prognostic value of assessing myocardial ischemic burden by CMR, and there are none using quantitative perfusion analysis. Patients with suspected coronary artery disease referred for adenosine-stress perfusion CMR were included (n = 395; 70% male; age 58 ± 13 years). The primary endpoint was a composite of cardiovascular death, nonfatal myocardial infarction, aborted sudden death, and revascularization after 90 days. Perfusion scans were assessed visually and with quantitative analysis. Cross-validated Cox regression analysis and net reclassification improvement were used to assess the incremental prognostic value of visual or quantitative perfusion analysis over a baseline clinical model, initially as continuous covariates, then using accepted thresholds of ≥2 segments or ≥10% myocardium. After a median 460 days (interquartile range: 190 to 869 days) follow-up, 52 patients reached the primary endpoint. At 2 years, the addition of ischemic burden was found to increase prognostic value over a baseline model of age, sex, and late gadolinium enhancement (baseline model area under the curve [AUC]: 0.75; visual AUC: 0.84; quantitative AUC: 0.85). Dichotomized quantitative ischemic burden performed better than visual assessment (net reclassification improvement 0.043 vs. 0.003 against baseline model). This study was the first to address the prognostic benefit of quantitative analysis of perfusion CMR and to support the use of consensus-based ischemic burden thresholds by perfusion CMR for prognostic evaluation of patients with suspected coronary artery disease. Quantitative analysis provided incremental prognostic value to visual assessment and

  6. Value choices and considerations when limiting intensive care treatment: a qualitative study.

    Science.gov (United States)

    Halvorsen, K; Førde, R; Nortvedt, P

    2009-01-01

    To shed light on the values and considerations that affect the decision-making processes and the decisions to limit intensive care treatment. Qualitative methodology with participant observation and in-depth interviews, with an emphasis on eliciting the underlying rationale of the clinicians' actions and choices when limiting treatment. Informants perceived over-treatment in intensive care medicine as a dilemma. One explanation was that the decision-making base was somewhat uncertain, complex and difficult. The informants claimed that those responsible for taking decisions from the admitting ward prolonged futile treatment because they may bear guilt or responsibility for something that had gone wrong during the course of treatment. The assessments of the patient's situation made by physicians from the admitting ward were often more organ-oriented and the expectations were less realistic than those of clinicians in the intensive care unit who frequently had a more balanced and overall perspective. Aspects such as the personality and the speciality of those involved, the culture of the unit and the degree of interdisciplinary cooperation were important issues in the decision-making processes. Under-communicated considerations jeopardise the principle of equal treatment. If intensive care patients are to be ensured equal treatment, strategies for interdisciplinary, transparent and appropriate decision-making processes must be developed in which open and hidden values are rendered visible, power structures disclosed, employees respected and the various perspectives of the treatment given their legitimate place.

  7. Stress intensity factors for complete internal and external cracks in spherical shells

    International Nuclear Information System (INIS)

    Chao, Y.J.; Chen, H.

    1989-01-01

    Cracks or flows found in the nuclear structure must be fully evaluated to assure the safety of the plant. The weight function method has been widely used in the determination of stress intensity factors for cracks under stress gradient e.g. for thermal shock loading. The unique features of the weight function method is that once the weight function for a particular cracked geometry is determined the stress intensity factors at the crack tip for any loading applied to the flawed structure can be calculated by a simple integration. In this paper the stress intensity factors of the complete, part-through internal and external cracks in a spherical shell are determined. The finite element method was used to develop the weight functions for the flawed geometry. The approximate crack surface profile was used to derive the weight functions. The stress intensity factors associated with the cracks in spherical shells under internal pressure are determined by both the weight functions and the direct finite element method

  8. The effect of massage therapy on occupational stress of Intensive Care Unit nurses.

    Science.gov (United States)

    Nazari, Fateme; Mirzamohamadi, Mojtaba; Yousefi, Hojatollah

    2015-01-01

    One of the main causes of stress in the lives of people is their jobs. Occupational stress is causing a wide range of significant issues in health and community services. Nursing is the most stressful profession in the health services. Massage therapy is one way of coping with stress. This study was conducted to determine the effect of massage therapy on stress in nurses. This study was a clinical trial on 66 male and female nurses working in intensive care units (dialysis, ICU, and CCU) of Isfahan University of Medical Sciences, Iran, in 2013. Participants were selected according to the aims and inclusion criteria of the study. Then, they were randomly divided into experimental and control groups. The Occupational Stress Inventory (OSI) (Osipow and Spokane, 1987) was completed by participants of the two groups before, immediately after, and 2 weeks after the intervention. General Swedish massage was performed on participants of the experimental group for 25 min in each session, twice a week for 4 weeks. Data were analyzed by descriptive and inferential statistics [Chi-square, t-test, and repeated measures analysis of variance (ANOVA)] using SPSS software. Results showed that the difference in overall mean occupation stress scores between experimental and control groups 2 weeks after the intervention was significant (P < 0.001). According to the results, it is recommended that massage, as a valuable noninvasive method, be used for nurses in intensive care units to reduce their stress, promote mental health, and prevent the decrease in quality of nursing work life.

  9. Intensity of emission lines of the quiescent solar corona: comparison between calculated and observed values

    Science.gov (United States)

    Krissinel, Boris

    2018-03-01

    The paper reports the results of calculations of the center-to-limb intensity of optically thin line emission in EUV and FUV wavelength ranges. The calculations employ a multicomponent model for the quiescent solar corona. The model includes a collection of loops of various sizes, spicules, and free (inter-loop) matter. Theoretical intensity values are found from probabilities of encountering parts of loops in the line of sight with respect to the probability of absence of other coronal components. The model uses 12 loops with sizes from 3200 to 210000 km with different values of rarefaction index and pressure at the loop base and apex. The temperature at loop apices is 1 400 000 K. The calculations utilize the CHIANTI database. The comparison between theoretical and observed emission intensity values for coronal and transition region lines obtained by the SUMER, CDS, and EIS telescopes shows quite satisfactory agreement between them, particularly for the solar disk center. For the data acquired above the limb, the enhanced discrepancies after the analysis refer to errors in EIS measurements.

  10. Stress level among intensive care nurses in the municipality of Paraná (Brazil

    Directory of Open Access Journals (Sweden)

    Kelly Cristina Inoue

    2014-04-01

    Full Text Available Objective. To identify stress levels among intensive care nurses who work in the municipality of Western Paraná, Brazil. Methodology. This is a cross-sectional cohort study, carried out from May to July 2010, included 60 nurses from intensive care units (adult, pediatric, or neonatal of five hospitals. All participants completed the Bianchi Stress Scale. Results. The mean participant age was 31 years; 70% of the nurses were women, 33% had more than 15 years of experience, and 88% conducted care activities. The general level of stress was medium. Stress levels were low for relationships with other units and supervisors, activities related to adequate functioning of the unit and the coordination of activities of the unit. Levels were medium for the following domains: activities related to personnel management, labor conditions for the development of nursing activities, and delivery of care to patient; this last domain was related to the following stress factors: facing patient death, attending to emergencies in the unit, advising patients' family members, and conducting tasks in the minimal time available. Conclusion. Although the general stress level was medium, the identification of domains with a high score can be used to plan intervention strategies to preserve the health of intensive care nurses and, in turn, improve quality of care delivered to severely ill patients.

  11. The effect of Residual Stress on the Stress Intensity Factor of Nuclear Material

    International Nuclear Information System (INIS)

    Song, Taek Ho

    2008-01-01

    As NPP (Nuclear Power Plant) gets aged, the importance of the pressure boundary integrity increases very much to those who are trying to operate their plant beyond its design life. Not long ago, Boric acid crystal was found at the RPV outlet nozzle of V.C. Summer plant during the visual examination in 2000. After this finding, non-destructive examination was taken to find out what's taken place. As a result of this examination, circumferential and axial cracks were found. With Metallurgical structure examination, it was shown that crack had been developed at the mid-point between Inco-alloy buttering and weld metal. It was turned out that high welding residual stress was the main cause of the cracking. Because of the through wall crack, nozzle and welding parts were replaced. Many other nuclear power plants experienced similar pressure boundary stress corrosion cracks (SCCs). KEPRI (Korea Electric Power Research Institute) has carried out research projects for managing and preventing these kinds of cracks in nuclear power plants (NPPs). The titles of these research projects are 'Development of Stress Corrosion Cracking Management Technology and Aging Monitor for NPP Main Components' and 'Development of Analysis Technology for Crack Management of Dissimilar Metal Weld'. Through these projects, residual stress measurement techniques have been exercised at various points in mock-up test specimens to simulate nuclear power plant dissimilar base metal and weldment residual stress. X-ray test and hole drilling method have been reviewed to measure residual stresses of the dissimilar metal welds. This paper shows some point of view in residual stress measurement. Fracture mechanics analysis has been performed to explain the importance of residual stress measurement in association with nuclear power plant safety

  12. Personality, stress and coping in intensive care nurses: a descriptive exploratory study.

    Science.gov (United States)

    Burgess, Lorraine; Irvine, Fiona; Wallymahmed, Akhtar

    2010-01-01

    The aim of the study was to investigate the relationship between personality traits, perception of workplace stress and coping among intensive care unit (ICU) nurses. Research has indicated that ICUs are stressful environments. There is a tendency for research studies to investigate causes of stress and ways of coping, but few studies, particularly in recent years, have considered the personality traits of the staff who thrive in this challenging environment, the work stress they perceive and the coping strategies they use. A convenience sample of critical care nurses (n = 46) completed three standardised questionnaires during September 2007: the revised NEO personality inventory (NEO-PI-R); the nurses stress scale (NSI) and the Brief Coping Orientations to Problems Experienced (COPE) scale. ICU nurses did not perceive their workplaces to be stressful. Certain personality traits, openness, agreeableness and conscientiousness, were associated with problem-solving coping strategies such as active planning and reframing. Openness and extraversion were associated with less perceived stress from the 'patients and relatives' dimension of the NSI; there were also negative correlations between conscientiousness and the 'workload stress' and stress from lack of 'confidence and competence' dimensions of the NSI. Certain personality traits may have a buffering effect on workplace stress. Pre-employment screening to identify staff that exhibit personality and coping traits associated with low perceived stress may be considered as part of the recruitment strategy to address problems relating to stress, sickness and retention. The retention and recruitment of staff who have lower perceived workplace stress and who utilise problem-focused coping may result in less reported absences and fewer critical incidents and errors.

  13. Intensive care diaries reduce new onset post traumatic stress disorder following critical illness

    DEFF Research Database (Denmark)

    Jones, Christina; Bäckman, Carl; Capuzzo, Maurizia

    2010-01-01

    Patients recovering from critical illness have been shown to be at risk of developing Post Traumatic Stress disorder (PTSD). This study was to evaluate whether a prospectively collected diary of a patient's intensive care unit (ICU) stay when used during convalescence following critical illness...

  14. Posttraumatic Stress Disorder's Frequency and Intensity Ratings Are Associated with Factor Structure Differences in Military Veterans

    Science.gov (United States)

    Elhai, Jon D.; Palmieri, Patrick A.; Biehn, Tracey L.; Frueh, B. Christopher; Magruder, Kathryn M.

    2010-01-01

    We examined possible differences in the factor structure of posttraumatic stress disorder (PTSD) on the basis of whether frequency or intensity symptom response formats were used to assess PTSD. Participants included 669 veterans recruited from an epidemiological study of four Veterans Affairs Medical Centers' primary care clinics in the…

  15. Review and synthesis of stress intensity factor solutions applicable to cracks in bolts

    International Nuclear Information System (INIS)

    James, L.A.; Mills, W.J.

    1988-01-01

    The available literature for stress intensity factor solutions for cracks in round bars, both threaded and unthreaded, subjected to either tension or bending, is reviewed. The results are synthesized into a form that is appropriate for the analysis of bolts and studs. (author)

  16. Evaluation of stress intensity factor for craks in surface of tubes with internal pressure

    International Nuclear Information System (INIS)

    Cesari, F.; Hellen, T.K.

    1977-01-01

    In this report the authors have examined the different methods for calculation of the stress intensity factor in tubes subject at internal pressure with surface cracks. The analysis includes cracks in 2-D axialsymmetric and 3-D. Moreover the authors have clarified the difference between the ASME Sec.11 and the procedure more rigorous

  17. Measurement and interpretation of threshold stress intensity factors for steels in high-pressure hydrogen gas.

    Energy Technology Data Exchange (ETDEWEB)

    Dadfarnia, Mohsen (University of Illinois at Urbana-Champaign, Urbana, IL); Nibur, Kevin A.; San Marchi, Christopher W.; Sofronis, Petros (University of Illinois at Urbana-Champaign, Urbana, IL); Somerday, Brian P.; Foulk, James W., III; Hayden, Gary A. (CP Industries, McKeesport, PA)

    2010-07-01

    Threshold stress intensity factors were measured in high-pressure hydrogen gas for a variety of low alloy ferritic steels using both constant crack opening displacement and rising crack opening displacement procedures. The sustained load cracking procedures are generally consistent with those in ASME Article KD-10 of Section VIII Division 3 of the Boiler and Pressure Vessel Code, which was recently published to guide design of high-pressure hydrogen vessels. Three definitions of threshold were established for the two test methods: K{sub THi}* is the maximum applied stress intensity factor for which no crack extension was observed under constant displacement; K{sub THa} is the stress intensity factor at the arrest position for a crack that extended under constant displacement; and K{sub JH} is the stress intensity factor at the onset of crack extension under rising displacement. The apparent crack initiation threshold under constant displacement, K{sub THi}*, and the crack arrest threshold, K{sub THa}, were both found to be non-conservative due to the hydrogen exposure and crack-tip deformation histories associated with typical procedures for sustained-load cracking tests under constant displacement. In contrast, K{sub JH}, which is measured under concurrent rising displacement and hydrogen gas exposure, provides a more conservative hydrogen-assisted fracture threshold that is relevant to structural components in which sub-critical crack extension is driven by internal hydrogen gas pressure.

  18. Suppression of Helicobacter pylori infection during intensive care stay: related to stress ulcer bleeding incidence?

    NARCIS (Netherlands)

    van der Voort, P. H.; van der Hulst, R. W.; Zandstra, D. F.; Geraedts, A. A.; van der Ende, A.; Tytgat, G. N.

    2001-01-01

    PURPOSE: To assess the prevalence of active Helicobacter pylori infection in patients admitted to the intensive care unit, to determine the effect of selective gut decontamination on the persistence of this organism, and to explore the possible relationship between H. pylori infection and stress

  19. Validation of surface crack stress intensity factors of a tubular K-joint

    International Nuclear Information System (INIS)

    Lie, S.T.; Lee, C.K.; Chiew, S.P.; Shao, Y.B.

    2005-01-01

    Tubular K-joints are encountered widely in offshore structures, and the prediction of damaged joints depends very much on the accuracy of stress intensity factor solutions (SIFs). No parametric equations and very few results have been proposed and published in the literature for estimating the SIFs of any K-joints subjected to complex loading conditions. In this paper, a mesh generation method proposed previously for the Y-joint and T-joint has been extended to the K-joint. This method is realized by dividing the K-joint into several sub-zones with each zone consisting of different types of elements and mesh densities. This method has a distinct advantage of controlling the mesh quality, and most importantly the aspect ratio of the elements along the crack front. When the mesh of all the sub-zones has been generated automatically and completely, they are merged to form the complete model. The two most commonly used methods, namely the J-integral and displacement extrapolation, are used to evaluate the SIF values along the crack front of a typical K-joint. To validate the accuracy of these computed SIFs, a full-scale K-joint specimen was tested to failure under fatigue loading conditions. The standard alternating current potential drop (ACPD) technique was used to monitor the rate of crack propagation of the surface crack located at the hot spot stress region. Using the given material parameters C and m, the experimental SIFs were deduced, and they are found to be in good agreement with the computed SIFs obtained from the generated models. Hence, the proposed finite element models are both efficient and reliable

  20. [Oxidative stress in Masters swimmers following high-intensity (interval) training (HI(I)T)].

    Science.gov (United States)

    Braun, Janina; Masoud, Magd; Brixius, Klara; Brinkmann, Christian

    2016-05-01

    Increased oxidative stress (OS) can promote diseases in the long term, but it can also trigger cellular adaptations in the short term. The present study aims to analyze whether a 3-month high-intensity (interval) training (HI(I)T) affects OS in 24 Masters swimmers (22-67 years) before (= basal) and after an all-out performance (swimming step-test). Data were analyzed for the entire group and differentiated according to sex and age (under 50 years (U50) and over 50 years (O50)). Prior to the HI(I)T intervention, a significant increase in OS from the basal to the all-out value was observed among the entire group and in the O50-subjects (subgroup analysis). Furthermore, significant increases in basal OS were evident for the entire group post-HI(I)T, but OS was only significantly increased in men in the subgroup analysis. No significant results were observed for women and U50-subjects. The response by Masters swimmers to HI(I)T depends on age and sex.

  1. A New Displacement-based Approach to Calculate Stress Intensity Factors With the Boundary Element Method

    Directory of Open Access Journals (Sweden)

    Marco Gonzalez

    Full Text Available Abstract The analysis of cracked brittle mechanical components considering linear elastic fracture mechanics is usually reduced to the evaluation of stress intensity factors (SIFs. The SIF calculation can be carried out experimentally, theoretically or numerically. Each methodology has its own advantages but the use of numerical methods has become very popular. Several schemes for numerical SIF calculations have been developed, the J-integral method being one of the most widely used because of its energy-like formulation. Additionally, some variations of the J-integral method, such as displacement-based methods, are also becoming popular due to their simplicity. In this work, a simple displacement-based scheme is proposed to calculate SIFs, and its performance is compared with contour integrals. These schemes are all implemented with the Boundary Element Method (BEM in order to exploit its advantages in crack growth modelling. Some simple examples are solved with the BEM and the calculated SIF values are compared against available solutions, showing good agreement between the different schemes.

  2. Time-course changes of oxidative stress response to high-intensity discontinuous training versus moderate-intensity continuous training in masters runners.

    Directory of Open Access Journals (Sweden)

    Alessandra Vezzoli

    Full Text Available Beneficial systemic effects of regular physical exercise have been demonstrated to reduce risks of a number of age-related disorders. Antioxidant capacity adaptations are amongst these fundamental changes in response to exercise training. However, it has been claimed that acute physical exercise performed at high intensity (>60% of maximal oxygen uptake may result in oxidative stress, due to reactive oxygen species being generated excessively by enhanced oxygen consumption. The aim of this study was to evaluate the effect of high-intensity discontinuous training (HIDT, characterized by repeated variations of intensity and changes of redox potential, on oxidative damage. Twenty long-distance masters runners (age 47.8 ± 7.8 yr on the basis of the individual values of gas exchange threshold were assigned to a different 8-weeks training program: continuous moderate-intensity training (MOD, n = 10 or HIDT (n = 10. In both groups before (PRE and after (POST training we examined the following oxidative damage markers: thiobarbituric acid reactive substances (TBARS as marker of lipid peroxidation; protein carbonyls (PC as marker of protein oxidation; 8-hydroxy-2-deoxy-guanosine (8-OH-dG as a biomarker of DNA base modifications; and total antioxidant capacity (TAC as indicator of the overall antioxidant system. Training induced a significant (p<0.05 decrease in resting plasma TBARS concentration in both MOD (7.53 ± 0.30 and 6.46 ± 0.27 µM, PRE and POST respectively and HIDT (7.21 ± 0.32 and 5.85 ± 0.46 µM, PRE and POST respectively. Resting urinary 8-OH-dG levels were significantly decreased in both MOD (5.50 ± 0.66 and 4.16 ± 0.40 ng mg(-1creatinine, PRE and POST respectively and HIDT (4.52 ± 0.50 and 3.18 ± 0.34 ng mg(-1creatinine, PRE and POST respectively. Training both in MOD and HIDT did not significantly modify plasma levels of PC. Resting plasma TAC was reduced in MOD while no significant changes were observed in HIDT. In conclusion

  3. The association between pregame snacks and exercise intensity, stress, and fatigue in children.

    Science.gov (United States)

    Sacheck, Jennifer M; Rasmussen, Helen M; Hall, Meghan M; Kafka, Tamar; Blumberg, Jeffrey B; Economos, Christina D

    2014-05-01

    To investigate the association between pregame snacks varying in macronutrient content and exercise intensity, physiological stress, and fatigue in young soccer players. One hour before a 50-min soccer game, children (n = 79; 9.1 ± 0.8 y) were randomly assigned to consume a raisin-, peanut-butter-, or cereal-based snack. Body mass index, blood glucose, and salivary measures of stress (cortisol and immunoglobulin A-IgA) were measured pre- and post-game. Exercise intensity was measured by accelerometry. Self-administered questionnaires were used to assess diet quality and fatigue. Analysis of covariance was used to examine the relationship between pregame snacks and biochemical outcomes. Postgame glucose and cortisol increased [12.9 ± 21.3 mg/dL (p fatigue (p fatigue but not changes in blood sugar or stress biomarkers following a soccer game in children.

  4. The EURISOL Beta-beam Facility: Parameter and Intensity Values, Version 2

    CERN Document Server

    Benedikt, M; Lindroos, M; Fabich, A

    An initial “bottom-up” analysis of ion intensities along the accelerator chain is revised to take into account more recent simulations of the stacking of 18Ne ions in the decay ring and beneficial trends in output flux as functions of certain machine parameters. In addition, space charge detuning at injection in the PS has led to a rethink of the top energy of the RCS, while that at injection in the SPS has had an impact on the number of bunches per batch delivered by the PS. We present transverse emittance values (which enter the space charge tune shift calculations) together with an updated list of intensities for both ion species under consideration in the baseline scenario.

  5. Further studies on stress intensity factors of semi-elliptical cracks in pressurized cylinders

    International Nuclear Information System (INIS)

    Kobayashi, A.S.; Emery, A.F.; Love, W.J.; Jain, A.

    1979-01-01

    The authors have used, in the past, the three-dimensional stress intensity magnification factor, Msub(KS), for a semi-elliptical surface crack in a flat plate with a curvature correction factor, Msub(C), to estimate the stress intensity magnification factor, Msub(K) = Msub(C) x Msub(KS), for unpressurized and pressurized inner semi-elliptical cracks and unpressurized outer semi-elliptical cracks in pressurized and thermally shocked cylinders. Recent papers by Atluri/Kathiresan, Welliot/Labbens/Pellissier-Tanon and McGowan/Raymund, however, showed that while this plate analogy with curvature correction provided reasonable estimates of the stress intensity factors at the deepest crack penetration, it underestimated the stress intensity factors at the cylindrical surface. The source of this discrepancy was traced to the curvature correction factor Msub(C), which was re-evaluated for various crack configurations and cylindrical geometries studied. Using the updated Msub(C) together with the previously derived Msub(KS), stress intensity factor magnification factor, Msub(K), was rederived for: (1) Pressurized and unpressurized inner semi-elliptical cracks of two crack aspects ratios of b/a = 0.2 and 0.98 at crack depth of b/(Rsub(o)-Rsub(i)) = 0.4, 0.6, and 0.8 in pressurized cylinders with outside-to-inside radius ratios of Rsub(o)/Rsub(i) = 3/2, 5/4, 7/6, and 10/9. (2) Unpressurized outer semi-elliptical cracks of two crack aspect ratios of b/a = 0.2 and 0.98 at crack depths of b/(Rsub(o)-Rsub(i)) = 0.4, 0.6, and 0.8 in pressurized cylinders with outside-to-inside radius ratio of Rsub(o)/Rsub(i) = 3/2, 5/4, 7/6, and 10/9. (orig.)

  6. Experimental and numerical determination of critical stress intensity factor of aluminum curved thin sheets under tensile stress

    Energy Technology Data Exchange (ETDEWEB)

    Heidarvand, Majid; Soltani, Naser; Hajializadeh, Farshid [University of Tehran, Tehran (Iran, Islamic Republic of)

    2017-05-15

    We determined the fracture toughness of aluminum curved thin sheets using tensile stress tests and finite element method. We applied Linear elastic fracture mechanics (LEFM) and Feddersen procedure to evaluate stress intensity factor of the samples with central wire-cut cracks and fatigue cracks with different lengths to investigate the notch radius effect. Special fixture design was utilized to establish uniform stress distribution at the crack zone. Less than 9 % difference was found between the wire-cut and the fatigue cracked samples. Since generating central fatigue crack with different lengths required so much effort, wire-cut cracked samples were used to determine critical stress intensity factor. Finite element analysis was also performed on one-quarter of the specimen using both the singular Borsum elements and the regular isoparametric elements to further investigate fracture toughness of the samples. It was observed that the singular elements presented better results than the isoparametric ones. A slight difference was also found between the results obtained from finite element method using singular elements and the experimental results.

  7. Adaptive value of phenological traits in stressful environments: predictions based on seed production and laboratory natural selection.

    Directory of Open Access Journals (Sweden)

    Benjamin Brachi

    Full Text Available Phenological traits often show variation within and among natural populations of annual plants. Nevertheless, the adaptive value of post-anthesis traits is seldom tested. In this study, we estimated the adaptive values of pre- and post-anthesis traits in two stressful environments (water stress and interspecific competition, using the selfing annual species Arabidopsis thaliana. By estimating seed production and by performing laboratory natural selection (LNS, we assessed the strength and nature (directional, disruptive and stabilizing of selection acting on phenological traits in A. thaliana under the two tested stress conditions, each with four intensities. Both the type of stress and its intensity affected the strength and nature of selection, as did genetic constraints among phenological traits. Under water stress, both experimental approaches demonstrated directional selection for a shorter life cycle, although bolting time imposes a genetic constraint on the length of the interval between bolting and anthesis. Under interspecific competition, results from the two experimental approaches showed discrepancies. Estimation of seed production predicted directional selection toward early pre-anthesis traits and long post-anthesis periods. In contrast, the LNS approach suggested neutrality for all phenological traits. This study opens questions on adaptation in complex natural environment where many selective pressures act simultaneously.

  8. [Stress in parents of hospitalized newborns in a neonatal intensive care unit].

    Science.gov (United States)

    Palma I, Elisa; Von Wussow K, Fernanda; Morales B, Ignacia; Cifuentes R, Javier; Ambiado T, Sergio

    2017-06-01

    The birth of a child that requires hospitalization in a Neonatal Intensive Care Unit (NICU) can be very stressful for parents. To determine the stress level of parents of newborns (NB) hospitalized in a level III NICU in Santiago, and its association with clinical and sociodemographic variables. Descriptive cross-sectional study. 373 admissions were evaluated. The sampling was non-probabilistic and included parents of RN admitted to the UPCN between 7 and 21 days of hospitalization. Only parents which have visited the RN at least three times were included. i) Questionnaire to obtain data which could not be obtained from the medical record; ii) Parental Stress Scale: Neonatal Intensive Care Unit (PSS:NICU) which measures the perception of parents about stressors from the physical and psychological environment of the UPCN. 100 parents of 59 hospitalized NB participated in the study. The average parental stress was 2.87±0.69. The subscale scores got higher was “Relationship with the baby and parental role”. Complications in pregnancy, prenatal diagnosis or prenatal hospitalization, did not affect the stress level or the presence of prematurity, respiratory diseases, congenital malformations, genopathies or requirement of mechanical ventilation. Stress levels presented in parents are unrelated to gender and to the studied clinical variables.

  9. Communicating with parents in neonatal intensive care units: The impact on parental stress.

    Science.gov (United States)

    Enke, Christian; Oliva Y Hausmann, Andrés; Miedaner, Felix; Roth, Bernhard; Woopen, Christiane

    2017-04-01

    To analyse stress in parents whose infants with very low birth weight have just concluded high-level care in a Neonatal Intensive Care Unit (NICU). More specifically, we aimed 1) to identify groups of parents in the NICU who are particularly at risk of experiencing stress, and 2) to explore the effects of clinical staffś communication on parental stress. Our multi-center-study evaluated views from 1277 parents about care for 923 infants in 66 German NICUs. Answers were linked with separately evaluated medical outcomes of the infants. Separate generalised mixed models estimated the influence of personal, medical and communication-related characteristics on specific parental stress. Parents of a younger age and those of infants with severe prognoses were more likely to experience stress. While empathetic communication as one aspect of staffś communication was shown as appropriate in reducing parental stress, an initial introduction and the quantity of information were only slightly associated with lower levels of stress. Results provide evidence for the need to involve parents empathetically from the beginning of their child's stay in the NICU. Staff in the NICU should communicate empathetically and help to reduce stress in parents particularly at risk. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Predictors of stress among parents in pediatric intensive care unit: a prospective observational study.

    Science.gov (United States)

    Aamir, Mohd; Mittal, Kundan; Kaushik, Jaya Shankar; Kashyap, Haripal; Kaur, Gurpreet

    2014-11-01

    To determine the sociodemographic and clinical factors leading to stress among parents whose children are admitted in pediatric intensive care unit (PICU). A prospective observational study was conducted in PICU of a tertiary care hospital of north India. Parents of children admitted to PICU for at least 48 h duration were eligible for participation. At the end of 48 h, parental stress was assessed using parental stress scale (PSS:PICU) questionnaire which was administered to the parents. Baseline demographic and clinical parameters of children admitted to PICU were recorded. The parental stress was compared with demographic and clinical characteristics of children using appropriate statistical methods. A total of 49 parents were finally eligible for participation. Mean (SD) parental stress scores was highest in domains of procedures [1.52 (0.66)] and behavior and emotional [1.32 (0.42)] subscales. Mean (SD) total parental stress score among intubated children [1.31 (0.25)] was significantly more than among non intubated children [0.97 (0.26)] (p parental stress score were comparable in terms of gender (p = 0.15) and socioeconomic status (p = 0.32). On subscale analysis, it was found that professional communication is a significant stressor in age groups 0-12 mo [0.61(0.41)] (p = 0.02). It was observed that parents of intubated children were significantly stressed by the physical appearance of their children (p parental role (p = 0.002). Total parental stress score had a positive correlation with PRISM score (r = 0.308). Indian parents are stressed maximally with environment of PICU. Factor leading to parental stress was intubation status of the child and was not affected by gender or socio demographic profile of the parents.

  11. A plastic stress intensity factor approach to turbine disk structural integrity assessment

    Directory of Open Access Journals (Sweden)

    V. Shlyannikov

    2016-07-01

    Full Text Available This study based on a new fracture mechanics parameter is concerned with assessing the integrity of cracked steam turbine disk which operate under startup-shutdown cyclic loading conditions. Damage accumulation and growth in service have occurred on the inner surface of slot fillet of key. In order to determine elastic-plastic fracture mechanics parameters full-size stress-strain state analysis of turbine disk was performed for a quote-elliptical part-through cracks under considering loading conditions. As a result distributions of elastic and plastic stress intensity factors along crack front in slot fillet of key of turbine disk depending on surface crack form are defined. An engineering approach to the prediction of carrying capacity of cracked turbine disk which is sensitive to the loading history at maintenance is proposed. The predictions of the rate of crack growth and residual lifetime of steam turbine disk are compared for elastic and elastic-plastic solutions. It is shown that the previously proposed elastic crack growth models provide overestimate the lifetime with respect to the present one. An advantage to use the plastic stress intensity factor to characterize the fracture resistance as the self-dependent unified parameter for a variety of turbine disk configurations rather than the magnitude of the elastic stress intensity factors alone is discussed.

  12. Value of stress ultrasound for the diagnosis of chronic ankle instability compared to manual anterior drawer test, stress radiography, magnetic resonance imaging, and arthroscopy.

    Science.gov (United States)

    Cho, Jae Ho; Lee, Doo Hyung; Song, Hyung Keun; Bang, Joon Young; Lee, Kyung Tai; Park, Young Uk

    2016-04-01

    Clinicians frequently diagnose chronic ankle instability using the manual anterior drawer test and stress radiography. However, both examinations can yield incorrect results and do not reveal the extent of ankle instability. Stress ultrasound has been reported to be a new diagnostic tool for the diagnosis of chronic ankle instability. The purpose of this study was to assess the diagnostic value of stress ultrasound for chronic ankle instability compared to the manual anterior drawer test, stress radiography, magnetic resonance imaging (MRI), and arthroscopy. Twenty-eight consecutive patients who underwent ankle arthroscopy and subsequent modified Broström repair for treatment of chronic ankle instability were included. The arthroscopic findings were used as the reference standard. A standardized physical examination (manual anterior drawer test), stress radiography, MRI, and stress ultrasound were performed to assess the anterior talofibular ligament (ATFL) prior to operation. Ultrasound images were taken in the resting position and the maximal anterior drawer position. Grade 3 lateral instability was verified arthroscopically in all 28 cases with a clinical diagnosis (100%). Twenty-two cases showed grade III instability on the manual anterior drawer test (78.6%). Twenty-four cases displayed anterior translation exceeding 5 mm on stress radiography (86%), and talar tilt angle exceeded 15° in three cases (11 %). Nineteen cases displayed a partial chronic tear (change in thickness or signal intensity), and nine cases displayed complete tear on MRI (100%). Lax and wavy ATFL was evident on stress ultrasound in all cases (100 %). The mean value of the ATFL length was 2.8 ± 0.3 cm for the stressed condition and 2.1 ± 0.2 cm for the resting condition (p radiography. III.

  13. Oxidative stress does not influence local sweat rate during high-intensity exercise.

    Science.gov (United States)

    Meade, Robert D; Fujii, Naoto; Poirier, Martin P; Boulay, Pierre; Sigal, Ronald J; Kenny, Glen P

    2018-02-01

    What is the central question of this study? We evaluated whether oxidative stress attenuates the contribution of nitric oxide to sweating during high-intensity exercise. What is the main finding and its importance? In contrast to our previous report of an oxidative stress-mediated reduction in nitric oxide-dependent cutaneous vasodilatation in this cohort during intense exercise, we demonstrated no influence of local ascorbate administration on the sweating response during moderate- (∼51% peak oxygen uptake) or high-intensity exercise (∼72% peak oxygen uptake). These new findings provide important mechanistic insight into how exercise-induced oxidative stress impacts sudomotor activity. Nitric oxide (NO)-dependent sweating is diminished during high- but not moderate-intensity exercise. We evaluated whether this impairment stems from increased oxidative stress during high-intensity exercise. On two separate days, 11 young (24 ± 4 years) men cycled in the heat (35°C) at a moderate [500 W; 52 ± 6% peak oxygen uptake (V̇O2 peak )] or high (700 W; 71 ± 5% V̇O2 peak ) rate of metabolic heat production. Each session included two 30 min exercise bouts separated by a 20 min recovery period. Local sweat rate was monitored at four forearm skin sites continuously perfused via intradermal microdialysis with the following: (i) lactated Ringer solution (Control); (ii) 10 mm ascorbate (Ascorbate; non-selective antioxidant); (iii) 10 mm N G -nitro-l-arginine methyl ester (l-NAME; NO synthase inhibitor); or (iv) 10 mm ascorbate plus 10 mm l-NAME (Ascorbate + l-NAME). During moderate exercise, sweat rate was attenuated at the l-NAME and Ascorbate + l-NAME sites (both ∼1.0 mg min -1  cm -2 ; all P < 0.05) but not at the Ascorbate site (∼1.1 mg min -1  cm -2 ; both P ≥ 0.28) in comparison to the Control site (∼1.1 mg min -1  cm -2 ). However, no differences were observed between treatment sites (∼1.4 mg min -1  cm -2 ; P = 0

  14. Functional Neuroimaging of Emotionally Intense Autobiographical Memories in Post-Traumatic Stress Disorder

    Science.gov (United States)

    St. Jacques, Peggy L.; Botzung, Anne; Miles, Amanda; Rubin, David C.

    2010-01-01

    Post-traumatic stress disorder (PTSD) affects regions that support autobiographical memory (AM) retrieval, such as the hippocampus, amygdala and ventral medial prefrontal cortex (PFC). However, it is not well understood how PTSD may impact the neural mechanisms of memory retrieval for the personal past. We used a generic cue method combined with parametric modulation analysis and functional MRI (fMRI) to investigate the neural mechanisms affected by PTSD symptoms during the retrieval of a large sample of emotionally intense AMs. There were three main results. First, the PTSD group showed greater recruitment of the amygdala/hippocampus during the construction of negative versus positive emotionally intense AMs, when compared to controls. Second, across both the construction and elaboration phases of retrieval the PTSD group showed greater recruitment of the ventral medial PFC for negatively intense memories, but less recruitment for positively intense memories. Third, the PTSD group showed greater functional coupling between the ventral medial PFC and the amygdala for negatively intense memories, but less coupling for positively intense memories. In sum, the fMRI data suggest that there was greater recruitment and coupling of emotional brain regions during the retrieval of negatively intense AMs in the PTSD group when compared to controls. PMID:21109253

  15. Thermal stress intensity factor for an axial crack in a clad cylinder

    International Nuclear Information System (INIS)

    Kuo, An Yu; Deardorf, A.F.; Riccardella, P.C.

    1993-01-01

    Many clad pressure vessels have been found to have cracks running through the inside surface cladding and into the base material. Although Young's moduli and Poisson's ratios of the clad and base materials are about the same for most of the industrial applications, coefficients of thermal expansion of the two dissimilar materials, clad and base materials, are usually quite different. For example, low alloy ferritic steel is a common base material for reactor pressure vessels (RPV) and the vessels are usually clad with austenitic stainless steel. Young's moduli for the low alloy steel and stainless steel at 350 F are 29,000 ksi and 28,000 ksi, respectively, while their coefficients of thermal expansion are 7.47x10 -6 in/in and 9.50x10 -6 in/in-degree F, respectively. The mismatch in coefficients of thermal expansion will cause high residual thermal stress even when the entire vessel is at a uniform temperature. This residual stress is one of the primary reasons why so many cracks have been found in the cladded components. In performing reactor pressure vessel integrity evaluation, such as computing probability of brittle fracture of the RPV, it is necessary to calculate stress intensity factors for cracks, which initiate from the clad material and run into the base metal. This paper presents a convenient method of calculating stress intensity factor for an axial crack emanating from the inside surface of a cladded cylinder under thermal loading. A J-integral like line integral was derived and used to calculate the stress intensity factors from finite element stress solutions of the problem

  16. Stress intensities for nozzle cracks in reactor vessels. Reporting period, January 1, 1976--October 31, 1976

    International Nuclear Information System (INIS)

    Smith, C.W.; Jolles, M.; Peters, W.H.

    1976-11-01

    A series of six frozen stress photoelastic tests was conducted to investigate the distribution of stress intensity factor (SIF) along a crack which occurred at the juncture of a pipe (nozzle) with a cylindrical pressure vessel. Typical photoelastic fringe patterns are shown for slices which were taken mutually orthogonal to the flaw border and the flaw surface. A typical plot of normalized apparent SIF versus square root of normalized distance from the crack tip is presented. The variation in SIF along the flaw border is given for all six different crack geometries and also the variation of SIF with varying a/T is presented. 40 references

  17. Low intensity aerobic exercise and oxidative stress markers in older adults.

    Science.gov (United States)

    Bouzid, Mohamed A; Hammouda, Omar; Matran, Régis; Robin, Sophie; Fabre, Claudine

    2014-10-01

    This comparative study examined the effects of regular low intensity aerobic exercise on oxidative stress markers in older adults. The study was carried out on 15 sedentary subjects (age: 65.1 ± 3.5 years) versus 18 subjects performing fitness exercises (age: 65.8 ± 3.3 years). Before and after an incremental exercise test, oxidative stress markers were assessed. Superoxide dismutase was higher at rest and at the recovery for the physically active subjects compared with sedentary subjects (p aerobic exercise may be useful to prevent the decline of antioxidants linked with aging.

  18. [The application of low-intensity electromagnetic radiation under immobilization stress conditions (an experimental study)].

    Science.gov (United States)

    Korolev, Iu N; Bobrovnitskiĭ, I P; Nikoulina, L A; Mikhaĭlik, L V; Geniatulina, M S; Bobkova, A S

    2014-01-01

    The experiments carried out on outbred male white rats with the use of optical, electron-microscopic, biochemical, and radioimmunological methods have demonstrated that the application of low-intensity electromagnetic radiation (LI-EMR) with a flow density of 1 mcW/cm2 and a frequency of around 1,000 MHz both in the primary prophylaxis regime and as the therapeuticpreventive modality arrested the development of post-stress disorders in the rat testicles, liver, and thymus; moreover, it promoted activation of the adaptive, preventive, and compensatory processes. The data obtained provide a rationale for the application of low-intensity electromagnetic radiation to protect the organism from negative effects of stressful factors.

  19. Analysis of stress intensity factors for surface cracks in pre/post penetration

    International Nuclear Information System (INIS)

    Miyoshi, Toshiro; Yoshida, Yuichiro

    1988-01-01

    It is important to evaluate the penetration of surface cracks in a Leak-Before-Break analysis. Because the stress intensity factors for surface cracks in pre/post penetration had not yet been analyzed, the authors carried three-dimensional boundary element analyses in order to obtain them. First, the authors developed the technique of nodal breakdown appropriate for cracks with short ligament length in a two-dimensional boundary element analysis. Next, analyses of stress intensity factor for surface cracks in pre/post penetration were carried out using the technique of nodal breakdown for cracks with short ligament length and the three-dimensional boundary element code BEM 3 D which was designed for a supercomputer. (author)

  20. Quantification of Protein Biomarker Using SERS Nano-Stress Sensing with Peak Intensity Ratiometry

    Science.gov (United States)

    Goh, Douglas; Kong, Kien Voon; Jayakumar, Perumal; Gong, Tianxun; Dinish, U. S.; Olivo, Malini

    We report a surface enhanced Raman spectroscopy (SERS) ratiometry method based on peak intensity coupled in a nano-stress sensing platform to detect and quantify biological molecules. Herein, we employed an antibody-conjugated p-aminothiophenol (ATP) functionalized on a bimetallic-film-over-nanosphere (BMFON) substrate as a sensitive SERS platform to detect human haptoglobin (Hp) protein, which is an acute phase protein and a biomarker for various cancers. Correlation between change in the ATP spectral characteristics and concentration of Hp protein was established by examining the peak intensity ratio at 1572cm-1 and 1592cm-1 that reflects the degree of stress experienced by the aromatic ring of ATP during Hp protein-antibody interaction. Development of this platform shows the potential in developing a low-cost and sensitive SERS sensor for the pre-screening of various biomarkers.

  1. Effects of Exercise Intensity on Postexercise Endothelial Function and Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Conor McClean

    2015-01-01

    Full Text Available Purpose. To measure endothelial function and oxidative stress immediately, 90 minutes, and three hours after exercise of varying intensities. Methods. Sixteen apparently healthy men completed three exercise bouts of treadmill running for 30 minutes at 55% V˙O2max (mild; 20 minutes at 75% V˙O2max (moderate; or 5 minutes at 100% V˙O2max (maximal in random order. Brachial artery flow-mediated dilation (FMD was assessed with venous blood samples drawn for measurement of endothelin-1 (ET-1, lipid hydroperoxides (LOOHs, and lipid soluble antioxidants. Results. LOOH increased immediately following moderate exercise (P0.05. Conclusions. Acute exercise at different intensities elicits varied effects on oxidative stress, shear rate, and ET-1 that do not appear to mediate changes in endothelial function measured by FMD.

  2. Stress Intensity Factor for Interface Cracks in Bimaterials Using Complex Variable Meshless Manifold Method

    Directory of Open Access Journals (Sweden)

    Hongfen Gao

    2014-01-01

    Full Text Available This paper describes the application of the complex variable meshless manifold method (CVMMM to stress intensity factor analyses of structures containing interface cracks between dissimilar materials. A discontinuous function and the near-tip asymptotic displacement functions are added to the CVMMM approximation using the framework of complex variable moving least-squares (CVMLS approximation. This enables the domain to be modeled by CVMMM without explicitly meshing the crack surfaces. The enriched crack-tip functions are chosen as those that span the asymptotic displacement fields for an interfacial crack. The complex stress intensity factors for bimaterial interfacial cracks were numerically evaluated using the method. Good agreement between the numerical results and the reference solutions for benchmark interfacial crack problems is realized.

  3. Stress intensity magnification factors for fully circumferential cracks in valve bodies (thick cylinders)

    International Nuclear Information System (INIS)

    Toor, P.M.

    1998-01-01

    The stress intensity solutions presented herein were obtained using an energy method in conjunction with a two-dimensional finite element program in order to explicitly account for curvature effect for fully circumferential cracks. The magnification factors for a specific crack depth were calculated by successively loading the crack surface by a uniform, linear, quadratic, and a cubic loading distribution. The magnification factors can be used to calculate the stress intensity factors by superposition method. The functions for each load condition in terms of radius to thickness ratio (R/t) and a fractional distance in terms of crack depth to thickness ratio (a/t) were developed. The validity of these functions is R/t = 1.5 to 10.0 and for 0.0125 ≤ a/t ≤ 0.8125. The functions agree to within 1% of the finite elements solutions for most magnification factors

  4. A virtual crack-closure technique for calculating stress intensity factors for cracked three dimensional bodies

    Science.gov (United States)

    Shivakumar, K. N.; Tan, P. W.; Newman, J. C., Jr.

    1988-01-01

    A three-dimensional virtual crack-closure technique is presented which calculates the strain energy release rates and the stress intensity factors using only nodal forces and displacements from a standard finite element analysis. The technique is an extension of the Rybicki-Kanninen (1977) method, and it assumes that any continuous function can be approximated by a finite number of straight line segments. Results obtained by the method for surface cracked plates with and without notches agree favorably with previous results.

  5. Pipe stress intensity factors and coupled depressurization and dynamic crack propagation. 1976 Annual report

    International Nuclear Information System (INIS)

    Emery, A.F.; Kobayashi, A.S.; Love, W.J.

    1978-04-01

    This report contains the description of predictive models for the initiation and propagation of cracks in pipes and the numerical results obtained. The initiation of the crack was studied by evaluating stress intensity factors under static conditions for a series of representative flaws. Three-dimensional static stress intensity factors were determined for quarter-elliptical cracks at the corner of a hole in an infinite plate and at the corner of a bore in a rotating disk. Semi-elliptical cracks for plates in bending and in pressurized and thermally stressed hollow cylinders were also evaluated. The stress fields, in the absence of a crack, were used in the ''alternating technique'' to compute the stress intensity factors along the crack front. Parametric studies were made to assess the effects of crack thickness, the ratio of the major and minor axes of the ellipse and the thickness of the cylinders or plates. These parametric results may be used to predict critical flaw sizes for the initiation of the running crack. The initiation and propagation of axial through cracks in pressurized pipes was studied by using an elastic-plastic finite different shell code coupled with a one-dimensional thermal-hydraulic code which computed the leakage through the crack opening and the depressurization of the fluid in the pipe. The effects of large deflections and different fluid pressure profiles were investigated. The results showed that the crack opening shape is dependent upon the fracture criterion used and upon the average pressure on the crack flaps, but not upon the specific pressure profile. The consideration of large deflections changed the opening size of the crack and through the coupling with the pipe pressures, strongly affected the crack tip speed. However, for equal crack lengths, there was little difference between calculations made for large and small deflection

  6. A study on the evaluation of dynamic stress intensity factor in repeated impact bending test

    International Nuclear Information System (INIS)

    Sim, Jae Ki; Cho, Gyu Jae; Han, Gill Young

    1988-01-01

    The purpose of the present paper was to establish the evaluation of the dynamic stress intensity factor in repeated impact three point bending test. Contact force between the impact bar and the cracked beam (simple supported beam) was analyzed by the using Hertz's contact law. In order to clarify the validity of theoretical analysis, experiments of dynamic stress intensity factir k I (t) are made on the cracked beam. The results obtained from this study are as follow: 1. In case of impact force analysis the theoretical result was obtained by the use of the Hertz's contact law. It's result was agreemant with the experimental result. Particularly, it was good agreement in the low impact velocity range. 2. The time variation of the dynamic stress intensity was determined by using the simple formula developed in this pqper. And the validity of it's result can be confirmed by experiment. Particlarly, this theoretical analysis was a good agreement to actual phenomena on from 0.3 msec to 0.65 msec. (Author)

  7. Nutritional value of breast and thigh muscle of chukar partridge (Alectoris chukar under intensive fattening conditions

    Directory of Open Access Journals (Sweden)

    Radovan Jůzl

    2012-01-01

    Full Text Available The aim of our study was to evaluate the nutritional value of the breast and thigh muscle of chukar partridge (Alectoris chukar under intensive fattening conditions. Commercial feeding mixtures for broilers were used. Live weight of 60 partridges (birds were not sexed was controlled during 90 days of fattening. After the fattening was finished, 30 birds were selected to monitor the carcass yield. Breast and thigh muscle were used for chemical analysis of crude protein (Kjeldahl method, total lipids (fat analyser ANKOMXT10, ash (Muffle furnace - 550° C and gross energy (calorimetry. Average values ​​of live weight were increasing in the course of fattening; at the end of fattening the live weight reached 0.452 kg. The carcass yield, breast muscle yield and thigh yield were evaluated (73.72%, 18.09%, 20.80%, respectively. Chemical analysis showed a highly significant difference (P ≤ 0.01 between the breast and thigh muscle for crude protein, fat, ash and gross energy. The ash content demonstrated a significant difference (P ≤ 0.05 between the breast and thigh muscle. This study brings new data on the nutritional value of the meat of chukar partridge that can be used for reccomendation of a suitable feeding mixture.

  8. Investigating Efficiency of Vector-Valued Intensity Measures in Seismic Demand Assessment of Concrete Dams

    Directory of Open Access Journals (Sweden)

    Mohammad Alembagheri

    2018-01-01

    Full Text Available The efficiency of vector-valued intensity measures for predicting the seismic demand in gravity dams is investigated. The Folsom gravity dam-reservoir coupled system is selected and numerically analyzed under a set of two-hundred actual ground motions. First, the well-defined scalar IMs are separately investigated, and then they are coupled to form two-parameter vector IMs. After that, IMs consisting of spectral acceleration at the first-mode natural period of the dam-reservoir system along with a measure of the spectral shape (the ratio of spectral acceleration at a second period to the first-mode spectral acceleration value are considered. It is attempted to determine the optimal second period by categorizing the spectral acceleration at the first-mode period of vibration. The efficiency of the proposed vector IMs is compared with scalar ones considering various structural responses as EDPs. Finally, the probabilistic seismic behavior of the dam is investigated by calculating its fragility curves employing scalar and vector IMs considering the effect of zero response values.

  9. Calculation of stress intensity factors for circumferential semi-elliptical cracks with high aspect ratio in pipes

    International Nuclear Information System (INIS)

    Zareei, A.; Nabavi, S.M.

    2016-01-01

    In this paper, stress intensity factors are calculated at the deepest point of an internal circumferential semi-elliptical crack in a pipe subjected to any arbitrary load. Based on the three dimensional finite element analysis, a weight function is proposed for high aspect ratio semi-elliptical cracks in pipes. An effective expression is developed analytically to evaluate the stress intensity factor using the weight function method. For several crack face stress fields and welding residual stress distributions, the weight function is validated against finite element data and those in the literature. Based on the comparison results, it can be concluded that the solution proposed in this paper is effective in engineering applications. - Highlights: • Analysis of internal circumferential semi-elliptical cracks with high aspect ratio in pipes. • A weight function is proposed for the calculation of the stress intensity factors for the deepest point of the crack. • An effective closed form expression is proposed to evaluate the stress intensity factors. • Prediction of stress intensity factors for any applied stress gradients through the wall thickness without any limitations. • A three-dimensional finite element modeling employs to calculate the stress intensity factors for different geometries.

  10. Improved Formula for the Stress Intensity Factor of Semi-Elliptical Surface Cracks in Welded Joints under Bending Stress

    Science.gov (United States)

    Peng, Yang; Wu, Chao; Zheng, Yifu; Dong, Jun

    2017-01-01

    Welded joints are prone to fatigue cracking with the existence of welding defects and bending stress. Fracture mechanics is a useful approach in which the fatigue life of the welded joint can be predicted. The key challenge of such predictions using fracture mechanics is how to accurately calculate the stress intensity factor (SIF). An empirical formula for calculating the SIF of welded joints under bending stress was developed by Baik, Yamada and Ishikawa based on the hybrid method. However, when calculating the SIF of a semi-elliptical crack, this study found that the accuracy of the Baik-Yamada formula was poor when comparing the benchmark results, experimental data and numerical results. The reasons for the reduced accuracy of the Baik-Yamada formula were identified and discussed in this paper. Furthermore, a new correction factor was developed and added to the Baik-Yamada formula by using theoretical analysis and numerical regression. Finally, the predictions using the modified Baik-Yamada formula were compared with the benchmark results, experimental data and numerical results. It was found that the accuracy of the modified Baik-Yamada formula was greatly improved. Therefore, it is proposed that this modified formula is used to conveniently and accurately calculate the SIF of semi-elliptical cracks in welded joints under bending stress. PMID:28772527

  11. Stress, coping and burnout among Intensive Care Unit nursing staff: associated factors.

    Science.gov (United States)

    Andolhe, Rafaela; Barbosa, Ricardo Luis; Oliveira, Elaine Machado de; Costa, Ana Lúcia Siqueira; Padilha, Katia Grillo

    2015-02-01

    Objective To investigate emotional stress, coping and burnout among nursing staff and their association with biosocial factors and characteristics of work in Intensive Care Units (ICU). Method This was a cross-sectional study, conducted in eight ICUs at a teaching hospital in the city of São Paulo, Brazil, in October 2012. Biosocial data and information about the professionals' work was gathered, and they were given the Scale of Occupational Stress, Scale of Occupational Coping, List of Signs and Symptoms of Stress and the Maslach Burnout Inventory. Results The study sample consisted of 287 subjects, predominately women, with partners and children. Most professionals presented moderate stress levels and control as a coping strategy (74.47% and 79.93%, respectively), and burnout was present among 12.54%. Factors associated with stress were related to working conditions. The most prevalent protective factors were having a partner, working in the clinical ICU and liking work, while adequate amount of sleep was a protective factor for burnout. Conclusion Control of the working environment and adequate sleep are decisive and protective factors in dealing with situations of occupational stress.

  12. Round Robin Analyses on Stress Intensity Factors of Inner Surface Cracks in Welded Stainless Steel Pipes

    Directory of Open Access Journals (Sweden)

    Chang-Gi Han

    2016-12-01

    Full Text Available Austenitic stainless steels (ASSs are widely used for nuclear pipes as they exhibit a good combination of mechanical properties and corrosion resistance. However, high tensile residual stresses may occur in ASS welds because postweld heat treatment is not generally conducted in order to avoid sensitization, which causes a stress corrosion crack. In this study, round robin analyses on stress intensity factors (SIFs were carried out to examine the appropriateness of structural integrity assessment methods for ASS pipe welds with two types of circumferential cracks. Typical stress profiles were generated from finite element analyses by considering residual stresses and normal operating conditions. Then, SIFs of cracked ASS pipes were determined by analytical equations represented in fitness-for-service assessment codes as well as reference finite element analyses. The discrepancies of estimated SIFs among round robin participants were confirmed due to different assessment procedures and relevant considerations, as well as the mistakes of participants. The effects of uncertainty factors on SIFs were deducted from sensitivity analyses and, based on the similarity and conservatism compared with detailed finite element analysis results, the R6 code, taking into account the applied internal pressure and combination of stress components, was recommended as the optimum procedure for SIF estimation.

  13. Influence of acute exercise of varying intensity and duration on postprandial oxidative stress.

    Science.gov (United States)

    Canale, Robert E; Farney, Tyler M; McCarthy, Cameron G; Bloomer, Richard J

    2014-09-01

    Aerobic exercise can reduce postprandial lipemia, and possibly oxidative stress, when performed prior to a lipid-rich meal. To compare the impact of acute exercise on postprandial oxidative stress. We compared aerobic and anaerobic exercise bouts of different intensities and durations on postprandial blood triglycerides (TAG), oxidative stress biomarkers (malondialdehyde, hydrogen peroxide, advanced oxidation protein products), and antioxidant status (trolox equivalent antioxidant capacity, superoxide dismutase, catalase, glutathione peroxidase). Twelve trained men (21-35 years) underwent four conditions: (1) No exercise rest; (2) 60-min aerobic exercise at 70% heart rate reserve; (3) five 60-s sprints at 100% max capacity; and (4) ten 15-s sprints at 200% max capacity. All exercise bouts were performed on a cycle ergometer. A high-fat meal was consumed 1 h after exercise cessation. Blood samples were collected pre-meal and 2 and 4 h post-meal and analyzed for TAG, oxidative stress biomarkers, and antioxidant status. No significant interaction or condition effects were noted for any variable (p > 0.05), with acute exercise having little to no effect on the magnitude of postprandial oxidative stress. In a sample of healthy, well-trained men, neither aerobic nor anaerobic exercise attenuates postprandial oxidative stress in response to a high-fat meal.

  14. Round robin analysis on stress intensity factor of inner surface cracks in welded stainless steel pipes

    Energy Technology Data Exchange (ETDEWEB)

    Han, Chang Gi; Chang, Yoon Suk [Dept. of Nuclear Engineering, College of Engineering, Kyung Hee University, Yongin (Korea, Republic of); Kim, Jong Sung [Dept. of Mechanical Engineering, Sunchon National University, Sunchon (Korea, Republic of); Kim, Maan Won [Central Research Institute, Korea Hydro and Nuclear Power Company, Daejeon (Korea, Republic of)

    2016-12-15

    Austenitic stainless steels (ASSs) are widely used for nuclear pipes as they exhibit a good combination of mechanical properties and corrosion resistance. However, high tensile residual stresses may occur in ASS welds because postweld heat treatment is not generally conducted in order to avoid sensitization, which causes a stress corrosion crack. In this study, round robin analyses on stress intensity factors (SIFs) were carried out to examine the appropriateness of structural integrity assessment methods for ASS pipe welds with two types of circumferential cracks. Typical stress profiles were generated from finite element analyses by considering residual stresses and normal operating conditions. Then, SIFs of cracked ASS pipes were determined by analytical equations represented in fitness-for-service assessment codes as well as reference finite element analyses. The discrepancies of estimated SIFs among round robin participants were confirmed due to different assessment procedures and relevant considerations, as well as the mistakes of participants. The effects of uncertainty factors on SIFs were deducted from sensitivity analyses and, based on the similarity and conservatism compared with detailed finite element analysis results, the R6 code, taking into account the applied internal pressure and combination of stress components, was recommended as the optimum procedure for SIF estimation.

  15. Specific features of peroxide stress in children permanently exposed to low-intensity radiation

    International Nuclear Information System (INIS)

    Durnov, L.A.; Bajkova, V.N.; Mayakova, S.A.; Polyakov, V.G.; Kolosov, E.A.; Dumbrajs, K.O.; Gracheva, I.V.; Zakharova, N.V.; Leonidova, Yu.A.; Romanova, L.F.

    2000-01-01

    To study the peculiarities of peroxide stress in children residing at the territories with chronic low-intensity radiation effects, the investigation was performed of tyrosine level, indices of the intensity of free radical lipid peroxidation and antioxidant system status in children and teenagers living in Sverdlovsk and Kolpnyansk districts of the Orel region contaminated due to the Chernobyl accident. Regions mentioned are characterized by low-intensity contamination with radionuclides (mainly 90 Sr, 131 I, 137 Cs), 25% an increase in tyrosine content, 1.8 times in malonic dial, 25-40 % in catalase and superoxide dismutase activity was revealed in blood plasma. Contents of A and E vitamins, glutathione and glutathione-depending enzymes are decreased. It is recommended to observe children health in regions contaminated as a result of the Chernobyl accident and correct failed redox processes using antioxidative vitamins [ru

  16. High-Intensity Interval Training, Appetite, and Reward Value of Food in the Obese

    DEFF Research Database (Denmark)

    Martins, Catia; Aschehoug, Irina; Ludviksen, Marit

    2017-01-01

    PURPOSE: Studies on the effect of chronic interval training on appetite in the obese population are scarce. The aim of this study was to determine the effect of 12 wk of isocaloric programs of moderate-intensity continuous training (MICT), high-intensity interval training (HIIT), or short......-duration HIIT on subjective feelings of appetite, appetite-related hormones, and reward value of food in sedentary obese individuals. METHODS: Forty-six sedentary obese individuals (30 women and 16 men), with a body mass index of 33.3 ± 2.9 kg·m and age of 34.4 ± 8.8 yr, were randomly assigned to one...... of the three training groups: MICT (n = 14), HIIT (n = 16), or short-duration HIIT (n = 16). Exercise was performed three times per week for 12 wk. Subjective feelings of appetite and plasma levels of acylated ghrelin, polypeptide YY3-36, and glucagon-like peptide 1 were measured before and after a standard...

  17. Coping With Staff Burnout and Work-Related Posttraumatic Stress in Intensive Care.

    Science.gov (United States)

    Colville, Gillian A; Smith, Jared G; Brierley, Joe; Citron, Kim; Nguru, Noreen M; Shaunak, Priyanka D; Tam, Olivia; Perkins-Porras, Linda

    2017-07-01

    To examine the associations with symptoms of 1) burnout and 2) work-related posttraumatic stress, in adult and pediatric intensive care staff, focusing on the particular contributions of resilience and coping strategies. Point prevalence cross-sectional study. Three adult ICUs and four PICUs. Three hundred seventy-seven ICU staff. None. Brief Resilience Scale, abbreviated Maslach Burnout Inventory, Trauma Screening Questionnaire, and Hospital Anxiety and Depression Scale. Prevalence of burnout (defined as high emotional exhaustion or high depersonalization) was 37%. Prevalence of clinically significant posttraumatic stress symptoms was 13%. There was a degree of overlap between burnout and other measures of distress, most notably for anxiety (odds ratio, 10.56; 95% CI, 4.12-27.02; p work-related distress (burnout: odds ratio, 0.52; 95% CI, 0.36-0.74; p stress: odds ratio, 0.28; 95% CI, 0.16-0.46; p stress were less if staff used talking to seniors (odds ratio, 0.43; 95% CI, 0.20-0.92; p = 0.029) or hobbies (odds ratio, 0.46; 95% CI, 0.23-0.93; p = 0.030) to cope with stress at work. Venting emotion (odds ratio, 1.92; 95% CI, 1.12-3.31; p = 0.018) and using alcohol (odds ratio, 2.30; 95% CI, 1.26-4.20; p = 0.006) were associated with a doubling in risk of reporting burnout. The use of particular coping strategies was systematically associated with symptoms of burnout and work-related posttraumatic stress in this group of intensive care staff, even after controlling for resilience and other factors. More research on how best to promote adaptive coping is needed in these challenging settings.

  18. Perceived Stress and Professional Quality of Life in Neonatal Intensive Care Unit Nurses in Gujarat, India.

    Science.gov (United States)

    Amin, Amee A; Vankar, Jagdish R; Nimbalkar, Somashekhar M; Phatak, Ajay G

    2015-11-01

    To study the levels of perceived stress in Neonatal Intensive Care Unit (NICU) nurses and its association with professional quality of life domains viz. compassion satisfaction, burnout and secondary trauma. In this multicenter, cross sectional study, data was collected by surveying 129 nurses from nine NICUs across six cities of Gujarat, India using demographic questionnaire, Perceived Stress Scale (PSS14) and Professional Quality of Life Scale (ProQOL5) during July to September 2013. Descriptive statistics, correlation coefficient and multiple regression were used for analysis. The mean (SD) age of participants was 28.37 (8.20) y. Most were single, satisfied with salary benefits and reported 'good' to 'excellent' relationships at work. The mean (SD) duration of duty hours was 8.12 (0.76) h and 43.6% were attending to more than 4 patients/shift. The mean (SD) perceived stress level was 22.19 (7.17) [Range: 3 to 39]. High compassion satisfaction, high burnout, and high secondary traumatic stress were reported by 25 (19.4%), 30 (23.3%) and 30 (23.3%) nurses respectively. PSS14 was negatively correlated with compassion satisfaction (r = -0.28) and positively correlated with burnout (r = 0.43) and secondary traumatic stress (r = 0.24). Most of the nurses (91, 70.5%) were identified as perceiving moderate to high stress. Professional quality of life domains correlated with perceived stress. There is further need to study domains influencing NICU nurses' professional QOL. Identifying stress and QOL issues in NICU nurses can help formulate relevant policies.

  19. Iranian parent-staff communication and parental stress in the neonatal Intensive Care Unit.

    Science.gov (United States)

    Hasanpour, Marzieh; Alavi, Mousa; Azizi, Fatemeh; Als, Heidelise; Armanian, Amir Mohmmad

    2017-01-01

    The birth of an infant requiring hospitalization in the neonatal Intensive Care Unit (NICU) uniformly is reported to be stressful for parents and family members. This study aimed to determine parent-staff communication in the NICU and its relationship to parent stress. Two hundred and three Iranian parents with preterm infants hospitalized in the NICU participated in this descriptive-correlational study. The participants were selected by the quota sampling method. Data collected included a three-part: questionnaire, the first part covered demographic parent and infant information, the second was the Parent-Staff Communication Scale (the score of which ranged from 0 to 180), and the third was the Parental Stress Scale (the score of which ranged from 0 to 102). Descriptive and inferential statistics including the Pearson's correlation coefficient test were applied to the data, using SPSS software Version 16. This study revealed that fathers and mothers' stress and communication scores were almost comparable and both higher than expected. The total mean score of the two main variables, i.e., parent-staff communication and parental stress were, respectively, 100.72 ± 18.89 and 75.26 ± 17.6. A significant inverse correlation was found between parental stress and parent-staff communication scores ( r = -0.144, P = 0.041). Based on this study finding showed that better parent-staff communication is related to lower parent stress scores, it is recommended that nurses and physicians receive specific skill training for the establishment of effective parent-staff communication. It is anticipated that such improved staff skills will help decrease parent stress and therewith likely promote parent and infant health in the NICU.

  20. Predictability of bone density at posterior mandibular implant sites using cone-beam computed tomography intensity values

    OpenAIRE

    Alkhader, Mustafa; Hudieb, Malik; Khader, Yousef

    2017-01-01

    Objective: The aim of this study was to investigate the predictability of bone density at posterior mandibular implant sites using cone-beam computed tomography (CBCT) intensity values. Materials and Methods: CBCT cross-sectional images for 436 posterior mandibular implant sites were selected for the study. Using Invivo software (Anatomage, San Jose, California, USA), two observers classified the bone density into three categories: low, intermediate, and high, and CBCT intensity values were g...

  1. Work stress, occupational burnout and depression levels: a clinical study of paediatric intensive care unit nurses in Taiwan.

    Science.gov (United States)

    Lin, Tzu-Ching; Lin, Huey-Shyan; Cheng, Su-Fen; Wu, Li-Min; Ou-Yang, Mei-Chen

    2016-04-01

    This study aimed to examine the relationship between work stress and depression; and investigate the mediating effect of occupational burnout among nurses in paediatric intensive care units. The relationships among work stress, occupational burnout and depression level have been explored, neither regarding occupational burnout as the mediating role that causes work stress to induce depression nor considering the paediatric intensive care unit context. A cross-sectional correlational design was conducted. One hundred and forty-four female paediatric intensive care unit nurses from seven teaching hospitals in southern Taiwan were recruited as the participants. Data were collected by structured questionnaires including individual demographics, the Nurse Stress Checklist, the Occupational Burnout Inventory and the Taiwan Depression Questionnaire. The results indicated that after controlling for individual demographic variables, the correlations of work stress with occupational burnout, as well as work stress and occupational burnout with depression level were all positive. Furthermore, occupational burnout may exert a partial mediating effect on the relationship between work stress and depression level. This study provides information about work stress, occupational burnout and depression level, and their correlations, as well as the mediating role of occupational burnout among paediatric intensive care unit nurses. It suggests government departments and hospital administrators when formulating interventions to prevent work stress and occupational burnout. These interventions can subsequently prevent episodes of depression in paediatric intensive care unit nurses, thereby providing patients with a safe and high-quality nursing environment. © 2016 John Wiley & Sons Ltd.

  2. Neonatal Intensive Care and Child Psychiatry Inpatient Care: Do Different Working Conditions Influence Stress Levels?

    Directory of Open Access Journals (Sweden)

    Evalotte Mörelius

    2013-01-01

    Full Text Available Introduction. Nurses often experience work-related stress. High stress can negatively affect job satisfaction and lead to emotional exhaustion with risk of burnout. Aim. To analyse possible differences in biological stress markers, psychosocial working conditions, health, and well-being between nurses working in two different departments. Methods. Stress was evaluated in nurses working in a neonatal intensive care unit (NICU (n=33 and nurses working in a child and adolescent psychiatry inpatient ward (CAP (n=14 using salivary cortisol and HbA1c. Salivary cortisol was measured three times a day on two consecutive days during two one-week periods, seven weeks apart (= 12 samples/person. Psychosocial working conditions, health, and well-being were measured once. Results. NICU nurses had better social support and more self-determination. CAP nurses had a lower salivary cortisol quotient, poorer general health, and higher client-related burnout scores. Conclusion. When comparing these nurses with existing norm data for Sweden, as a group their scores reflect less work-related stress than Swedes overall. However, the comparison between NICU and CAP nurses indicates a less healthy work situation for CAP nurses. Relevance to Clinical Practice. Healthcare managers need to acknowledge the less healthy work situation CAP nurses experience in order to provide optimal support and promote good health.

  3. Predictability of bone density at posterior mandibular implant sites using cone-beam computed tomography intensity values.

    Science.gov (United States)

    Alkhader, Mustafa; Hudieb, Malik; Khader, Yousef

    2017-01-01

    The aim of this study was to investigate the predictability of bone density at posterior mandibular implant sites using cone-beam computed tomography (CBCT) intensity values. CBCT cross-sectional images for 436 posterior mandibular implant sites were selected for the study. Using Invivo software (Anatomage, San Jose, California, USA), two observers classified the bone density into three categories: low, intermediate, and high, and CBCT intensity values were generated. Based on the consensus of the two observers, 15.6% of sites were of low bone density, 47.9% were of intermediate density, and 36.5% were of high density. Receiver-operating characteristic analysis showed that CBCT intensity values had a high predictive power for predicting high density sites (area under the curve [AUC] =0.94, P < 0.005) and intermediate density sites (AUC = 0.81, P < 0.005). The best cut-off value for intensity to predict intermediate density sites was 218 (sensitivity = 0.77 and specificity = 0.76) and the best cut-off value for intensity to predict high density sites was 403 (sensitivity = 0.93 and specificity = 0.77). CBCT intensity values are considered useful for predicting bone density at posterior mandibular implant sites.

  4. The stress and stress intensity factors computation by BEM and FEM combination for nozzle junction under pressure and thermal loads

    International Nuclear Information System (INIS)

    Du, Q.; Cen, Z.; Zhu, H.

    1989-01-01

    This paper reports linear elastic fracture analysis based upon the stress intensity factor evaluation successfully applied to safety assessments of cracked structures. The nozzle junction are usually subjected to high pressure and thermal loads simultaneously. In validity of linear elastic fracture analysis, K can be decomposed into K P (caused by mechanic loads) and K τ (caused by thermal loads). Under thermal transient loading, explicit analysis (say by the FEM or BEM) of K tracing an entire history respectively for a range of crack depth may be much more time consuming. The techniques of weight function provide efficient means for transforming the problem into the stress computation of the uncracked structure and generation of influence function (for the given structure and size of crack). In this paper, a combination of BE-FEM has been used for the analysis of the cracked nozzle structure by techniques of weight function. The influence functions are obtained by coupled BE-FEM and the uncracked structure stress are computed by finite element methods

  5. Razlike med spoloma pri nekaterih simptomih stresa ter intenzivnost doživljanja stresnih simptomov = Gender Differences in Some Stress Symptoms and Intensity of Experiencing Stress Symptoms

    Directory of Open Access Journals (Sweden)

    Maja Meško

    2010-06-01

    Full Text Available The aim of this study was to identify the symptoms of stress and to establishgender differences in stress symptoms. We tried to find out ifthere are gender differences in the stress level at work, if there aregender differences in terms of stress symptoms frequency, and if thereare gender differences in terms of the intensity of experiencing stresssymptoms. In this study 85 randomly selected managers from Slovenecompanies participated. The results of the study have shown that thereare gender differences in terms of all the above mentioned factors,namely a statistically higher level of stress in women. In terms of stresssymptoms occurrence there are gender differences in some stress symptomsas well as in the intensity of experiencing stress symptoms.

  6. High-Intensity Interval Training, Appetite, and Reward Value of Food in the Obese.

    Science.gov (United States)

    Martins, Catia; Aschehoug, Irina; Ludviksen, Marit; Holst, Jens; Finlayson, Graham; Wisloff, Ulrik; Morgan, Linda; King, Neil; Kulseng, Bård

    2017-09-01

    Studies on the effect of chronic interval training on appetite in the obese population are scarce. The aim of this study was to determine the effect of 12 wk of isocaloric programs of moderate-intensity continuous training (MICT), high-intensity interval training (HIIT), or short-duration HIIT on subjective feelings of appetite, appetite-related hormones, and reward value of food in sedentary obese individuals. Forty-six sedentary obese individuals (30 women and 16 men), with a body mass index of 33.3 ± 2.9 kg·m and age of 34.4 ± 8.8 yr, were randomly assigned to one of the three training groups: MICT (n = 14), HIIT (n = 16), or short-duration HIIT (n = 16). Exercise was performed three times per week for 12 wk. Subjective feelings of appetite and plasma levels of acylated ghrelin, polypeptide YY3-36, and glucagon-like peptide 1 were measured before and after a standard breakfast (every 30 min up to 3 h), before and after the exercise intervention. Fat and sweet taste preferences and food reward were measured using the Leeds Food Preference Questionnaire. A significant increase in fasting and postprandial feelings of hunger was observed with the exercise intervention (P = 0.01 and P = 0.048, respectively), but no effect of group and no interaction. No significant effect of exercise intervention, group, or interaction was found on fasting or postprandial subjective feelings of fullness, desire to eat, and prospective food consumption or plasma concentration of acylated ghrelin, polypeptide YY3-36, and glucagon-like peptide 1. No changes in food preference or reward over time, differences between groups, or interactions were found. This study suggests that chronic HIIT has no independent effect on appetite or food reward when compared with an isocaloric program of MICT in obese individuals.

  7. Response of coral assemblages to thermal stress: are bleaching intensity and spatial patterns consistent between events?

    Science.gov (United States)

    Penin, Lucie; Vidal-Dupiol, Jeremie; Adjeroud, Mehdi

    2013-06-01

    Mass bleaching events resulting in coral mortality are among the greatest threats to coral reefs, and are projected to increase in frequency and intensity with global warming. Achieving a better understanding of the consistency of the response of coral assemblages to thermal stress, both spatially and temporally, is essential to determine which reefs are more able to tolerate climate change. We compared variations in spatial and taxonomic patterns between two bleaching events at the scale of an island (Moorea Island, French Polynesia). Despite similar thermal stress and light conditions, bleaching intensity was significantly lower in 2007 (approximately 37 % of colonies showed signs of bleaching) than in 2002, when 55 % of the colonies bleached. Variations in the spatial patterns of bleaching intensity were consistent between the two events. Among nine sampling stations at three locations and three depths, the stations at which the bleaching response was lowest in 2002 were those that showed the lowest levels of bleaching in 2007. The taxonomic patterns of susceptibility to bleaching were also consistent between the two events. These findings have important implications for conservation because they indicate that corals are capable of acclimatization and/or adaptation and that, even at small spatial scales, some areas are consistently more susceptible to bleaching than others.

  8. A definition and evaluation procedure of generalized stress intensity factors at cracks and multi-material wedges

    International Nuclear Information System (INIS)

    Song Chongmin

    2010-01-01

    A definition of generalized stress intensity factors is proposed. It is based on a matrix function solution for singular stress fields obtained from the scaled boundary finite-element method. The dimensions of the matrix are equal to the number of singular terms. Not only real and complex power singularities but also power-logarithmic singularities are represented in a unified expression without explicitly determining the type of singularity. The generalized stress intensity factors are evaluated directly from the definition by following standard stress recovery procedures in the finite element method. Numerical examples are presented to valid the definition and evaluation procedure.

  9. Massage therapy in cortisol circadian rhythm, pain intensity, perceived stress index and quality of life of fibromyalgia syndrome patients.

    Science.gov (United States)

    de Oliveira, Felipe Rodrigues; Visnardi Gonçalves, Laura Cristina; Borghi, Filipy; da Silva, Larissa Gabriela Rocha Ventura; Gomes, Anne Elise; Trevisan, Gustavo; Luiz de Souza, Aglécio; Grassi-Kassisse, Dora Maria; de Oliveira Crege, Danilo Roberto Xavier

    2018-02-01

    We investigate the effects of a massage therapy program (MTP) in cortisol concentration (CC), intensity of pain, quality of life and perceived stress index of fibromyalgia patients. Volunteers (n = 24, aged 26-55 years) were treated with MT, twice a week for three months. They answered the Fibromyalgia Impact Questionnaire (FIQ), Perceived Stress Questionnaire (PSQ) and McGill Pain Questionnaire (MPQ-Br), and collected saliva to evaluate CC before and after the end of each month. The MT had improvement in quality of life, according to the FIQ results, and promoted reduction in PSQ values after the second (PSQ2-0.62 ± 0.04vsPSQ0-0.71 ± 0.04) and third month (PSQ3-0.64 ± 0.04vsPSQ0-0.71 ± 0.04). The MTP also promoted reduction in pain after the third month (MQP-Br1-44.50 ± 2.15vsMQP-Br4-35.38 ± 3.71). Despite PSQ reduction, the CC were not affected by the program. This pilot suggests that this treatment improved quality of life, reduced perceived stress index and pain in these volunteers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Preventing overtraining in athletes in high-intensity sports and stress/recovery monitoring.

    Science.gov (United States)

    Kellmann, M

    2010-10-01

    In sports, the importance of optimizing the recovery-stress state is critical. Effective recovery from intense training loads often faced by elite athletes can often determine sporting success or failure. In recent decades, athletes, coaches, and sport scientists have been keen to find creative, new methods for improving the quality and quantity of training for athletes. These efforts have consistently faced barriers, including overtraining, fatigue, injury, illness, and burnout. Physiological and psychological limits dictate a need for research that addresses the avoidance of overtraining, maximizes recovery, and successfully negotiates the fine line between high and excessive training loads. Monitoring instruments like the Recovery-Stress Questionnaire for Athletes can assist with this research by providing a tool to assess their perceived state of recovery. This article will highlight the importance of recovery for elite athletes and provide an overview of monitoring instruments. © 2010 John Wiley & Sons A/S.

  11. Burnout syndrome--assessment of a stressful job among intensive care staff.

    Science.gov (United States)

    Cubrilo-Turek, Mirjana; Urek, Roman; Turek, Stjepan

    2006-03-01

    The purpose of the study was to investigate the degree of burnout experienced by intensive care staff particularly, in Medical (MICU) and Surgical Intensive Care Units (SICU) General Hospital "Sveti Duh", Zagreb. A sample group of 41 emergency physicians and nurses from MICU and 30 from SICU was tested. The survey included demographic data and Maslach Burnout Inventory (MBI) scoring test identified by the three main components associated with burnout: emotional exhaustion (MBI-EE), depersonalization (MBI-DEP), and personal accomplishment (MBI-PA) were assessed using 22-item questionnaire. The degrees of burnout were stratified into low, moderate, and high range. Mean total MBI (X +/- SD) were high in both groups: higher for the MICU (65.5 +/- 6.7) than for SICU staff (55.7 +/- 3.8, p burnout represented in a moderate degree. The presence of burnout is a serious phenomenon, because it can lead to psychosomatic complaints, work-associated withdrawal behaviour, and a lower quality of care at intensive care units. Early recognition of burnout phenomenon as a result of prolonged stress and frustration among intensive care staff, contributes to better professional behavior, organizational structure changes in the work environment and better health care quality for critically ill patients.

  12. Stress-intensity factor equations for cracks in three-dimensional finite bodies subjected to tension and bending loads

    Science.gov (United States)

    Newman, J. C., Jr.; Raju, I. S.

    1984-01-01

    Stress intensity factor equations are presented for an embedded elliptical crack, a semielliptical surface crack, a quarter elliptical corner crack, a semielliptical surface crack along the bore of a circular hole, and a quarter elliptical corner crack at the edge of a circular hole in finite plates. The plates were subjected to either remote tension or bending loads. The stress intensity factors used to develop these equations were obtained from previous three dimensional finite element analyses of these crack configurations. The equations give stress intensity factors as a function of parametric angle, crack depth, crack length, plate thickness, and, where applicable, hole radius. The ratio of crack depth to plate thickness ranged from 0 to 1, the ratio of crack depth to crack length ranged from 0.2 to 2, and the ratio of hole radius to plate thickness ranged from 0.5 to 2. The effects of plate width on stress intensity variation along the crack front were also included.

  13. Impact of an intensive dynamic exercise program on oxidative stress and on the outcome in patients with fibromyalgia

    Directory of Open Access Journals (Sweden)

    Amal F Soliman

    2016-01-01

    Conclusion Twelve weeks of intensive dynamic exercise program should be recommended to patients with FM as it was effective in decreasing the oxidative stress parameters, increasing the antioxidant parameters, and improving the clinical outcome of this disease.

  14. Mode I Stress Intensity Factors for triangular corner crack nearby intersecting of cylindrical holes

    Directory of Open Access Journals (Sweden)

    E. Salvati

    2013-10-01

    Full Text Available In this paper triangular flaws has been taken into account at the intersection of two holes inside a specified specimen. Influence of bore hole D1/D2 and angle between their axes α are examined. Numerical analysis are performed to determine Stress Intensity factors (SIF in many geometric configurations. Afterwards, fitting weight function’s parameters with FEM results, new SIF analytics expression are shown. Finally, the accuracy of weight functions in SIF predictions for different inner pressure, has been checked as well as the comparison between the SIF of a triangular crack and that of an actual crack shape obtained through a fatigue test.

  15. The value of routine chest radiographs in a paediatric intensive care unit: a prospective study

    International Nuclear Information System (INIS)

    Valk, J.W.; Ploetz, F.B.; Schuerman, F.A.B.A.; Vught, H. van; Kramer, P.P.G.; Beek, E.J.A.

    2001-01-01

    Background. In many paediatric intensive care units (PICUs) chest X-ray films (CXRs) are required as part of the daily examination or after completion of invasive procedures. Objective. First, to evaluate if the American College of Radiology (ACR) guidelines for adult patients are appropriate for paediatric pa- tients. Second, to assess the diagnostic efficacy of the CXRs. Materials and methods. One-hundred-seventy-four CXRs acquired in 74 patients, either routinely or after invasive procedures, were analysed. The indication of the obtained CXRs, or the absence of indication in patients in whom no CXRs was taken, was compared with ACR guidelines. The position of medical devices was evaluated. Changes in cardiopulmonary status were noted. Results. Sixty-seven percent of the CXRs were in accordance with the ACR guidelines, and in 74 % of pa- tients in whom no CXRs were taken this was also in accordance with these guidelines. Sixteen percent of the endotracheal tubes, 23 % of central venous lines and 15 % of nasogastric tubes were malpositioned. Changes in cardiopulmonary status, after the initial film, were noted in 63 %. Conclusions. The indications for the majority of CXRs in our PICU appeared to be in accordance with ACR guidelines. The high percentage of malpositioned tubes and lines and the number of cardiopulmonary changes on CXRs in a PICU underline the value of these films. Adjustments of the ACR guidelines for particular groups of paediatric patients may limit the number of CXRs taken and may further increase diagnostic efficacy. (orig.)

  16. [The relevance of ADC value, T₁intensive rate and the clinical activities in ankylosing spondylitis sacroiliitis].

    Science.gov (United States)

    Zhao, Yinghua; Han, Xinai; Hu, Shaoyong; Shi, Xingliang; Zhao, Jing; Sun, Erwei; Li, Shaolin

    2014-09-23

    To evaluate the value of judging for the activity in AS by diffusion-weighted sequences (DWI) and enhance sequences MRI(DCE-MRI), to explore the correlation of Apparent diffusion coefficient(ADC) values, intensive rate and the clinical activity index in sacroiliitis (SIJ) of ankylosing spondylitis (AS). 56 patients prospectively choiced and diagnosed were divided into two groupsas, active group (n = 32) and chronic group (n = 24) by rheumatologist according to BASDAI and laboratory parameters. Twenty healthy adults were as control group. The values of ADC and intensive rate of all sacroiliac joints (SIJs) were measured on MRI. BASDAI score were got by Bath ankylosing spondylitis disease activity index. ESR, CPR and were got by laboratory. Statisticaly to analysis whether the parameters were significantly different amang AS active, chronic, and the control group. To assess the correlation of the values of ADC, intensive rate and BASDAI score, ESR, CPR and in SIJ. the values of ADC and intensive rate were significantly different among AS active, chronic and the control group. There were the significant correlation between the values of ADC, intensive rate and BASDAI score. Diffusion-weighted sequences and Contrast-enhanced sequences is superior to other methods in judging the activity in AS.combined with clinical activity index, the accuracy can significantly be improved to explore whether the activities of AS are.

  17. Comparison of diagnostic value of coronary artery disease between ATP-stress and exercise-stress thallium myocardial SPECT images

    International Nuclear Information System (INIS)

    Suzuki, Shigeo

    1994-01-01

    A study was made between adenosine triphosphate disodium (ATP)-stress thallium myocardial scintigrams and exercise-stress scintigrams to compare their respective extents and degree of defects. The subjects of the study were 33 ischemic heart disease patients, who received ATP stress and treadmill exercise stress with a mean interval of 25 days. ATP was infused for 5 minutes with an infusion rate of 0.16 or 0.18 mg per kg of body weight per minute. Thallium was injected three minutes after infusion. The percent-defect index (percentage of the extent and degree of the defects for all 33 patients), was calculated with visual scoring using a five-zone myocardial division method and semi-quantitative four-grade representation method for both the ATP and exercise SPECT images. The extent of the defects in ATP- and exercise-stress images was 51.5% and 44.2%, and that in redistribution images was 36.4% and 33.9%, respectively. The degree of defects in ATP- and exercise-stress images was 35.8% and 32.3%, while that in redistribution images was 20.8% and 17.2%, respectively (p=NS in all cases). In conclusion, the image quality of thallium SPECT with ATP stress was equivalent that of exercise stress, indicating identical diagnostic values for coronary lesions. (author)

  18. Clinical and epidemiological study of stress hyperglycemia among medical intensive care unit patients in Central India

    Directory of Open Access Journals (Sweden)

    Jitendra Sharma

    2017-01-01

    Full Text Available Background: Stress hyperglycemia is common in patients presenting at the emergency medical ward and is associated with poor prognosis and increased risk of mortality. Aims and Objective: To study and determine the prevalence and factors associated with stress hyperglycemia. Materials and Methods: A cross-sectional observational study was performed on 536 nondiabetic patients presented to the Intensive Care Unit (ICU at Gandhi Medical College and allied Hamidia Hospital, Bhopal, between March 31, 2015, and May 28, 2015. A detailed history including demographic profile, presence of chronic disease, history of hospitalization and ICU admission, surgical status, and major reason for ICU admission (i.e., predominant diagnostic category was collected. Hematological and other parameters based on profile of study population were also analyzed. Results: Out of 536 patients, 109 (20.33% had stress hyperglycemia. Out of 109 patients with stress hyperglycemia, 87 (16.23% patients had glycated hemoglobin (HbA1c <5.7% and 22 (4.10% patients had HbA1c between 5.7% and 6.4%. Mean age of the study population was 40.27 ± 1.44 years, with male dominance. Mean random blood glucose level was 181.46 ± 3.80 mg/dl. Frequency of stress hyperglycemia was 24.13% in stroke, 19.54% in multiple organ dysfunction syndrome (MODS, 17.24% in chronic kidney disease (CKD, 12.64% in central nervous system (CNS infection, 8.05% in chronic liver disease (CLD, and 8.05% in seizure patients. Association between stroke and stress hyperglycemia was significant (P = 0.036. Association between hospital stay more than 7 days and stress hyperglycemia was significant in stroke patients (P = 0.0029, CKD patients (P = 0.0036, CLD (P = 0.0099, and MODS patients (P = 0.0328. Conclusions: The factors associated with stress hyperglycemia were stroke, MODS, CKD, CNS infection, CLD, seizure patients, with prolonged hospital stay and expected proportion.

  19. DIRECT CALCULUS FORMULAS FOR THE LATHE TOOL EQUIVALENT STRESS VALUES DURING THE MANUFACTURING OF STEEL SHAFTS

    Directory of Open Access Journals (Sweden)

    Catălin ROŞU

    2015-05-01

    Full Text Available In this paper, starting from the stress values presented in Roşu (2015 [1], a method for determining direct calculus formulas for the lathe tool equivalent stress values during the manufacturing of steel shafts is established. There is used the regression analysis for the formulas determination. The equivalent stress will be dependant on the cutting depth. The obtained formulas will be verified by using an analytical model from Strength of Materials. The results and the calculus formulas are presented from an original point of view.

  20. Fear conditioning and shock intensity: the choice between minimizing the stress induced and reducing the number of animals used

    NARCIS (Netherlands)

    Pietersen, C.Y.; Bosker, F.J; Posterna, F.; Den Boer, J.A.

    2006-01-01

    Many fear conditioning studies use electric shock as the aversive stimulus. The intensity of shocks varies throughout the literature. In this study, shock intensities ranging from 0 to 1.5 mA were used, and the effects on the rats assessed by both behavioural and biochemical stress parameters.

  1. Fear conditioning and shock intensity : the choice between minimizing the stress induced and reducing the number of animals used

    NARCIS (Netherlands)

    Pietersen, CY; Bosker, FJ; Posterna, F; den Boer, JA

    Many fear conditioning studies use electric shock as the aversive stimulus. The intensity of shocks varies throughout the literature. In this study, shock intensities ranging from 0 to 1.5 mA were used, and the effects on the rats assessed by both behavioural and biochemical stress parameters.

  2. The physiological stress response to high-intensity sprint exercise following the ingestion of sodium bicarbonate.

    Science.gov (United States)

    Peart, Daniel J; Kirk, Richard J; Hillman, Angela R; Madden, Leigh A; Siegler, Jason C; Vince, Rebecca V

    2013-01-01

    The purpose of this study was to investigate the effects of pre-exercise alkalosis on the physiological stress response to high-intensity exercise. Seven physically active males (age 22 ± 3 years, height 1.82 ± 0.06 m, mass 81.3 ± 8.4 kg and peak power output 300 ± 22 W) performed a repeated sprint cycle exercise following a dose of 0.3 g kg(-1) body mass of sodium bicarbonate (NaHCO(3)) (BICARB), or a placebo of 0.045 g kg(-1) body mass of sodium chloride (PLAC). Monocyte-expressed heat shock protein 72 (HSP72) and plasma thiobarbituric acid reactive substances (TBARS) were significantly attenuated in BICARB compared to PLAC (p = 0.04 and p = 0.039, respectively), however total anti-oxidant capacity, the ratio of oxidised to total glutathione, cortisol, interleukin 6 and interleukin 8 were not significantly induced by the exercise. In conclusion, monocyte-expressed HSP72 is significantly increased following high-intensity anaerobic exercise, and its attenuation following such exercise with the ingestion of NaHCO(3) is unlikely to be due to a decreased oxidative stress.

  3. Photobiomodulation Leads to Reduced Oxidative Stress in Rats Submitted to High-Intensity Resistive Exercise

    Directory of Open Access Journals (Sweden)

    Helenita Antonia de Oliveira

    2018-01-01

    Full Text Available The aim of this study was to determine whether oxidative stress markers are influenced by low-intensity laser therapy (LLLT in rats subjected to a high-intensity resistive exercise session (RE. Female Wistar rats divided into three experimental groups (Ctr: control, 4J: LLLT, and RE and subdivided based on the sampling times (instantly or 24 h postexercise underwent irradiation with LLLT using three-point transcutaneous method on the hind legs, which was applied to the gastrocnemius muscle at the distal, medial, and proximal points. Laser (4J or placebo (device off were carried out 60 sec prior to RE that consisted of four climbs bearing the maximum load with a 2 min time interval between each climb. Lipoperoxidation levels and antioxidant capacity were obtained in muscle. Lipoperoxidation levels were increased (4-HNE and CL markers instantly post-RE. LLLT prior to RE avoided the increase of the lipid peroxidation levels. Similar results were also notified for oxidation protein assays. The GPx and FRAP activities did not reduce instantly or 24 h after RE. SOD increased 24 h after RE, while CAT activity did not change with RE or LLLT. In conclusion, LLLT prior to RE reduced the oxidative stress markers, as well as, avoided reduction, and still increased the antioxidant capacity.

  4. A Non-parametric Method for Calculating Conditional Stressed Value at Risk

    Directory of Open Access Journals (Sweden)

    Kohei Marumo

    2017-01-01

    Full Text Available We consider the Value at Risk (VaR of a portfolio under stressed conditions. In practice, the stressed VaR (sVaR is commonly calculated using the data set that includes the stressed period. It tells us how much the risk amount increases if we use the stressed data set. In this paper, we consider the VaR under stress scenarios. Technically, this can be done by deriving the distribution of profit or loss conditioned on the value of risk factors. We use two methods; the one that uses the linear model and the one that uses the Hermite expansion discussed by Marumo and Wolff (2013, 2016. Numerical examples shows that the method using the Hermite expansion is capable of capturing the non-linear effects such as correlation collapse and volatility clustering, which are often observed in the markets.

  5. Effect of Schisandrae on stress system of soldiers undergone high-intensity military training

    Directory of Open Access Journals (Sweden)

    Nan XIA

    2014-03-01

    Full Text Available Objective To explore the changes in basic serum levels of hypothalamus-pituitrin-adrenal (HPA axis, hypothalamus-pituitrin-gonad (HPG axis and proinflammatory cytokines IL-1, IL-2 and IL-6 in repeated acute stress caused by one-week intensive training, and study the effects of oral administration of Schisandrae, salidroside and Schisandrae compound on the contents of those stress hormones and cytokines mentioned above. Methods One hundred and twenty healthy soldiers chosen from junior infantry combat troops who had never received long-term amphibious training were randomly divided into four groups (30 each: group A (Schisandrae compound group, group B (Schisandrae group, group C (salidroside group and group D (control group. Each and every soldier of all the groups underwent high-intensity composite military training, 8 hours per day, for a week. Venous blood sampling was collected at 7:00-8:00 a.m. before and after the training, respectively. Levels of cortisol (CORT, adrenocorticotropic hormone (ACTH, testosterone (T, IL-1, IL-2 and IL-6 in different groups were measured by radioimmunoassay (RIA. The changes in the levels of all the above mentioned hormones and cytokines in every group were observed and compared. Results In group D, as compared with the pre-stress levels, no marked difference was found in the levels of serum CORT and ACTH (P>0.05, but the levels of T and IL-6 significantly decreased (P0.05. In group C, the levels of T and IL-6 significantly decreased (P0.05. In group A, the serum levels of CORT, ACTH, T, IL-1 and IL-6 significantly decreased, while that of IL-2 significantly increased (P<0.01. As compared with group D, the level of ACTH in group A and group B, the level of IL-2 in group C significantly decreased (P<0.05. Conclusions  Schisandrae and Schisandrae compound have a marked and lasting inhibitory effect on the activation of HPA axis and the elevation of serum CORT levels induced by stress, while the similar

  6. Temporal variance reverses the impact of high mean intensity of stress in climate change experiments.

    Science.gov (United States)

    Benedetti-Cecchi, Lisandro; Bertocci, Iacopo; Vaselli, Stefano; Maggi, Elena

    2006-10-01

    Extreme climate events produce simultaneous changes to the mean and to the variance of climatic variables over ecological time scales. While several studies have investigated how ecological systems respond to changes in mean values of climate variables, the combined effects of mean and variance are poorly understood. We examined the response of low-shore assemblages of algae and invertebrates of rocky seashores in the northwest Mediterranean to factorial manipulations of mean intensity and temporal variance of aerial exposure, a type of disturbance whose intensity and temporal patterning of occurrence are predicted to change with changing climate conditions. Effects of variance were often in the opposite direction of those elicited by changes in the mean. Increasing aerial exposure at regular intervals had negative effects both on diversity of assemblages and on percent cover of filamentous and coarsely branched algae, but greater temporal variance drastically reduced these effects. The opposite was observed for the abundance of barnacles and encrusting coralline algae, where high temporal variance of aerial exposure either reversed a positive effect of mean intensity (barnacles) or caused a negative effect that did not occur under low temporal variance (encrusting algae). These results provide the first experimental evidence that changes in mean intensity and temporal variance of climatic variables affect natural assemblages of species interactively, suggesting that high temporal variance may mitigate the ecological impacts of ongoing and predicted climate changes.

  7. Effect of ubiquinol supplementation on biochemical and oxidative stress indexes after intense exercise in young athletes.

    Science.gov (United States)

    Orlando, Patrick; Silvestri, Sonia; Galeazzi, Roberta; Antonicelli, Roberto; Marcheggiani, Fabio; Cirilli, Ilenia; Bacchetti, Tiziana; Tiano, Luca

    2018-12-01

    Physical exercise significantly impacts the biochemistry of the organism. Ubiquinone is a key component of the mitochondrial respiratory chain and ubiquinol, its reduced and active form, is an emerging molecule in sport nutrition. The aim of this study was to evaluate the effect of ubiquinol supplementation on biochemical and oxidative stress indexes after an intense bout of exercise. 21 male young athletes (26 + 5 years of age) were randomized in two groups according to a double blind cross-over study, either supplemented with ubiquinol (200 mg/day) or placebo for 1 month. Blood was withdrawn before and after a single bout of intense exercise (40 min run at 85% maxHR). Physical performance, hematochemical parameters, ubiquinone/ubiquinol plasma content, intracellular reactive oxygen species (ROS) level, mitochondrial membrane depolarization, paraoxonase activity and oxidative DNA damage were analyzed. A single bout of intense exercise produced a significant increase in most hematochemical indexes, in particular CK and Mb while, on the contrary, normalized coenzyme Q 10 plasma content decreased significantly in all subjects. Ubiquinol supplementation prevented exercise-induced CoQ deprivation and decrease in paraoxonase activity. Moreover at a cellular level, in peripheral blood mononuclear cells, ubiquinol supplementation was associated with a significant decrease in cytosolic ROS while mitochondrial membrane potential and oxidative DNA damage remained unchanged. Data highlights a very rapid dynamic of CoQ depletion following intense exercise underlying an increased demand by the organism. Ubiquinol supplementation minimized exercise-induced depletion and enhanced plasma and cellular antioxidant levels but it was not able to improve physical performance indexes or markers of muscular damage.

  8. Stress intensity factors for deep cracks emanating from the corner formed by a hole intersecting a plate surface

    Science.gov (United States)

    Mcgowan, J. J.; Smith, C. W.

    1976-01-01

    The stress intensity factors (SIFs) at the end points of flaws emanating from the corner formed by the intersection of a plate with a hole were determined using stress freezing photoelasticity and a numerical technique known as the Taylor series correction method to extract the SIF values from the photoelastic data. The geometries studied were crack depth to thickness ratios of about 0.2, 0.5, and 0.75; crack depth to crack length ratios of about 1.0 to 2.0; and crack length to hole radius ratios of about 0.5 to 2.0. The SIFs were determined at the intersection of the flaw border with the plate surface (KS) and with the edge of the hole (KH). It is shown that extension of a crack emanating from a corner of intersection of a hole with a plate under monotonically increasing load is not self-similar and that as the flaw depth increases, KH decreases and KS increases. Existing theories and design criteria significantly overestimate the SIF at both the hole and the surface except for shallow flaws at the hole and deep flaws at the surface.

  9. Effects of distance from center of a weld to fixed end on residual stress and stress intensity factor of a piping weld. Evaluation of SCC growth under residual stress field. Report 1

    International Nuclear Information System (INIS)

    Miyazaki, Katsumasa; Numata, Masanori; Saito, Koichi; Mochizuki, Masahito

    2006-01-01

    The fixed conditions of butt welds between straight pipe and valve or pump in the actual piping system are different from those of straight pipes. However, the effect of fixed condition on the residual stress and the stress intensity factor for evaluation of structural integrity of cracked piping was not clear. In this study, the finite element analyses were conducted by considering the differences in the distance from the center of weld to the fixed end L to clarify the effect of fixed condition on the residual stress and the stress intensity factor. For the 600 A piping, the axial residual stress distribution was not affected by the distance L. Furthermore, the stress intensity factor of circumferential crack under the residual stress field with fixed condition could be estimated by using the existing simplified solution for piping. (author)

  10. Hybrid determination of mixed-mode stress intensity factors on discontinuous finite-width plate by finite element and photoelasticity

    International Nuclear Information System (INIS)

    Baek, Tae Hyun; Chen, Lei; Hong, Dong Pyo

    2011-01-01

    For isotropic material structure, the stress in the vicinity of crack tip is generally much higher than the stress far away from it. This phenomenon usually leads to stress concentration and fracture of structure. Previous researches and studies show that the stress intensity factor is one of most important parameter for crack growth and propagation. This paper provides a convenient numerical method, which is called hybrid photoelasticity method, to accurately determine the stress field distribution in the vicinity of crack tip and mixed-mode stress intensity factors. The model was simulated by finite element method and isochromatic data along straight lines far away from the crack tip were calculated. By using the isochromatic data obtained from finite element method and a conformal mapping procedure, stress components and photoelastic fringes in the hybrid region were calculated. To easily compare calculated photoelastic fringes with experiment results, the fringe patterns were reconstructed, doubled and sharpened. Good agreement shows that the method presented in this paper is reliable and convenient. This method can then directly be applied to obtain mixed mode stress intensity factors from the experimentally measured isochromatic data along the straight lines

  11. Posttraumatic stress disorder in children and their parents following admission to the pediatric intensive care unit: a review.

    Science.gov (United States)

    Nelson, Lara P; Gold, Jeffrey I

    2012-05-01

    To evaluate posttraumatic stress disorder in children who have been admitted to the pediatric intensive care unit and their families. Studies were identified through PubMed, MEDLINE, and Ovid. All descriptive, observational, and controlled studies with a focus on posttraumatic stress disorder and the pediatric intensive care unit were included. Posttraumatic stress disorder rates in children following admission to the pediatric intensive care unit were between 5% and 28%, while rates of posttraumatic stress disorder symptoms were significantly higher, 35% to 62%. There have been inconsistencies noted across risk factors. Objective and subjective measurements of disease severity were intermittently positively associated with development of posttraumatic stress disorder. There was a positive relationship identified between the child's symptoms of posttraumatic stress disorder and their parents' symptoms.The biological mechanisms associated with the development of posttraumatic stress disorder in children admitted to the pediatric intensive care unit have yet to be explored. Studies in children following burn or other unintentional injury demonstrate potential relationships between adrenergic hormone levels and a diagnosis of posttraumatic stress disorder. Likewise genetic studies suggest the importance of the adrenergic system in this pathway.The rates of posttraumatic stress disorder in parents following their child's admission to the pediatric intensive care unit ranged between 10.5% and 21%, with symptom rates approaching 84%. It has been suggested that mothers are at increased risk for the development of posttraumatic stress disorder compared to fathers. Objective and subjective measures of disease severity yielded mixed findings with regard to the development of posttraumatic stress disorder. Protective parental factors may include education or the opportunity to discuss the parents' feelings during the admission. Following admission to the pediatric intensive

  12. Dynamic response of the scenic beauty value of different forests to various thinning intensities in central eastern China.

    Science.gov (United States)

    Deng, Songqiu; Yin, Na; Guan, Qingwei; Katoh, Masato

    2014-11-01

    Forest management has a significant influence on the preferences of people for forest landscapes. This study sought to evaluate the dynamic effects of thinning intensities on the landscape value of forests over time. Five typical stands in Wuxiangsi National Forest Park in Nanjing, China, were subjected to a thinning experiment designed with four intensities: unthinned, light thinning, moderate thinning, and heavy thinning. People's preferences for landscape photographs taken in plots under various thinning intensities were assessed through scenic beauty estimation (SBE) at 2 and 5 years after thinning. The differences in scenic beauty value between different thinning intensities were then analyzed with a paired samples t test for the two periods. The results indicated that the landscape value of all of the thinned plots significantly exceeded that of the unthinned plots 2 years after thinning (p beautiful than the lightly thinned and moderately thinned plots, whereas there was no significant difference between moderate thinning and light thinning. At 5 years after thinning, however, the moderately thinned plots received the highest preference scores among the four intensities, displaying an average improvement of 11.32 % compared with the unthinned plots. A multiple linear regression (MLR) model indicated that landscape value improved with increases in the average diameter at breast height (DBH) and with the improvement of environmental cleanliness in the stand, whereas the value decreased with an increasing stem density, species diversity, litter coverage, and canopy density. In addition, we found that the performance of a neural network model based on a multilayer perception (MLP) algorithm for predicting scenic beauty was slightly better than that of the MLR model. The findings of our study suggest that moderate to heavy thinning should be recommended to manage forests for the improvement of forest landscape value.

  13. Green's functions for stress-intensity-factors for through cracks emanating from holes

    International Nuclear Information System (INIS)

    Bhandari, S.; Dubeaux, P.

    1981-01-01

    We conducted a parametric study of cracks at various elliptical openings in plates. We used five values of ellipticity and ten values of crack lengths at the edge of these holes. The computer program used is based on the Boundary Integral Equation method which requires only the contour of the structure to be segmented. The results concerning the stress distribution in the uncracked structure were verified for the cases where analytical results were available. Moreover the values of the S.I.F. for certain cases were checked through the use of some of the methods available in the literature. The final aim of this parametric study is to come up with simple Green's functions for cracks at holes. This has been possible through: (a) The use of the stress distribution in the uncracked structure (b) The Green's function for a crack in an infinite medium and (c) The principles underlying the Schwarz alternating technique used in the potential theory to resolve problems of finite regions. Finally the procedure is applied to treat a practical case of cracks as fastner holes. (orig.)

  14. Stress intensity factors of three parallel edge cracks under bending moments

    International Nuclear Information System (INIS)

    Ismail, A E

    2013-01-01

    This paper reports the study of stress intensity factors (SIF) of three edge cracks in a finite plate under bending moments. The goal of this paper was to analyze the three edge crack interactions under such loading. Several studies can be found in literature discussing on mode I SIF. However, most of these studies obtained the SIFs using tensile force. Lack of SIF reported discussing on the SIFs obtained under bending moments. ANSYS finite element program was used to develop the finite element model where singular elements were used to model the cracks. Different crack geometries and parameters were utilized in order to characterize the SIFs. According to the present results, crack geometries played a significant role in determining the SIFs and consequently induced the crack interaction mechanisms

  15. Various methods of numerical estimation of generalized stress intensity factors of bi-material notches

    Directory of Open Access Journals (Sweden)

    Klusák J.

    2009-12-01

    Full Text Available The study of bi-material notches becomes a topical problem as they can model efficiently geometrical or material discontinuities. When assessing crack initiation conditions in the bi-material notches, the generalized stress intensity factors H have to be calculated. Contrary to the determination of the K-factor for a crack in an isotropic homogeneous medium, for the ascertainment of the H-factor there is no procedure incorporated in the calculation systems. The calculation of these fracture parameters requires experience. Direct methods of estimation of H-factors need choosing usually length parameter entering into calculation. On the other hand the method combining the application of the reciprocal theorem (Ψ-integral and FEM does not require entering any length parameter and is capable to extract the near-tip information directly from the far-field deformation.

  16. Stress intensity factors of eccentric cracks in bi-materials plate under mode I loading

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, A. E. [Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, 86400 Batu Pahat, Johor (Malaysia)

    2015-05-15

    Bi-material plates were generally used to joint electronic devices or mechanical components requiring dissimilar materials to be attached. During services, mechanical failure can be occurred due to the formation of cracks at the interfacial joint or away from the centre. Generally, linear elastic fracture mechanics approach is used to characterize these cracks based on stress intensity factors (SIF). Based on the literature survey, the SIFs for the central cracks were easily available. However, the SIFs for eccentric cracks were difficult to obtain. Therefore, this paper presented the SIFs for eccentric cracks subjected to mode I tension loading. Three important parameters were used such as relative crack depth, a/L, relative offset distance, b/L and elastic mismatch, E{sub 1}/E{sub 2} or α. It was found that such parameters significantly affected the characteristic of SIFs and it was depend on the location of cracks.

  17. Low Intensity Physical Exercise Attenuates Cardiac Remodeling and Myocardial Oxidative Stress and Dysfunction in Diabetic Rats

    Directory of Open Access Journals (Sweden)

    C. Gimenes

    2015-01-01

    Full Text Available We evaluated the effects of a low intensity aerobic exercise protocol on cardiac remodeling and myocardial function in diabetic rats. Wistar rats were assigned into four groups: sedentary control (C-Sed, exercised control (C-Ex, sedentary diabetes (DM-Sed, and exercised diabetes (DM-Ex. Diabetes was induced by intraperitoneal injection of streptozotocin. Rats exercised for 9 weeks in treadmill at 11 m/min, 18 min/day. Myocardial function was evaluated in left ventricular (LV papillary muscles and oxidative stress in LV tissue. Statistical analysis was given by ANOVA or Kruskal-Wallis. Echocardiogram showed diabetic groups with higher LV diastolic diameter-to-body weight ratio and lower posterior wall shortening velocity than controls. Left atrium diameter was lower in DM-Ex than DM-Sed (C-Sed: 5.73±0.49; C-Ex: 5.67±0.53; DM-Sed: 6.41±0.54; DM-Ex: 5.81±0.50 mm; P<0.05 DM-Sed vs C-Sed and DM-Ex. Papillary muscle function was depressed in DM-Sed compared to C-Sed. Exercise attenuated this change in DM-Ex. Lipid hydroperoxide concentration was higher in DM-Sed than C-Sed and DM-Ex. Catalase and superoxide dismutase activities were lower in diabetics than controls and higher in DM-Ex than DM-Sed. Glutathione peroxidase activity was lower in DM-Sed than C-Sed and DM-Ex. Conclusion. Low intensity exercise attenuates left atrium dilation and myocardial oxidative stress and dysfunction in type 1 diabetic rats.

  18. Towards a better understanding of the dynamics of value creation in R&D intensive small firms

    NARCIS (Netherlands)

    Casault, Sébastien; Groen, Aard J.; Linton, Jonathan D.

    2017-01-01

    Standard financial and economic theories suggest that the stock value of R&D intensive High Technology Small Firms (HTSF) undergo a geometric random walk. Such a model neglects to account for observed periods where firms experience large fluctuations due to uncertainty related to its R&D activities,

  19. Stress in parents of very low birth weight preterm infants hospitalized in neonatal intensive care units. A multicenter study.

    Science.gov (United States)

    Wormald, Francisca; Tapia, José L; Torres, Gabriela; Cánepa, Paula; González, María Aurelia; Rodríguez, Diana; Escobar, Marisol; Reyes, Bernardita; Capelli, Carola; Menéndez, Laura; Delgado, Patricia; Treuer, Sergio; Ramírez, Rodrigo; Borja, Norma; Domínguez, Angélica

    2015-08-01

    The birth of a premature baby is a stressful event for parents. The objective of this study was to determine early stress in parents of very low birth weight infants (VLBWIs) hospitalized in 12 neonatal intensive care units from a South American Neonatal Network, to identify associated factors, and to compare the level of parental stress in public versus private healthcare facilities. Cross-sectional study in mothers/fathers of VLBWIs (500 to 1500 g). Early parental stress was measured using the Parental Stressor Scale, with a score from 1 (low stress) to 5 (high stress). The sociodemographic characteristics of parents and newborn infants were collected and associated with levels of parental stress. The study included 273 fathers/mothers of a total of 218 VLBW preterm infants. The survey was administered at 5.9 ± 2.0 days of life. The average total parental stress was 3.1 ± 0.8, and the highest score was obtained for the parental role subscale (3.6). A lower education level, unemployment, not having held the newborn infant, and respiratory support requirement were associated with higher parental stress levels. Stress was higher among mothers than fathers, and at public facilities versus private ones. Among parents of VLBWIs, a moderate early parental stress was observed. Parental role alteration was the most relevant factor. Parental stress was higher among mothers and at public healthcare facilities. A greater sensitization, further research and interventions in this area are required.

  20. Racial-Ethnic Disparities in Maternal Parenting Stress: The Role of Structural Disadvantages and Parenting Values

    Science.gov (United States)

    Nomaguchi, Kei; House, Amanda N.

    2013-01-01

    Although researchers contend that racial-ethnic minorities experience more stress than whites, knowledge of racial-ethnic disparities in parenting stress is limited. Using a pooled time-series analysis of data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998–99 (n = 11,324), we examine racial-ethnic differences in maternal parenting stress, with a focus on structural and cultural explanations and variations by nativity and child age. In kindergarten, black mothers, albeit U.S.-born only, report more parenting stress than white mothers due to structural disadvantages and authoritarian parenting values. The black-white gap increases from kindergarten to third grade, and in third grade, U.S.-born black mothers’ higher stress than white mothers’ persists after controlling for structural and parenting factors. Hispanic and Asian mothers, albeit foreign-born only, report more stress than white mothers at both ages due to structural disadvantages and authoritarian values. Despite structural disadvantages, American Indian mothers report less stress. PMID:24026535

  1. Racial-ethnic disparities in maternal parenting stress: the role of structural disadvantages and parenting values.

    Science.gov (United States)

    Nomaguchi, Kei; House, Amanda N

    2013-01-01

    Although researchers contend that racial-ethnic minorities experience more stress than whites, knowledge of racial-ethnic disparities in parenting stress is limited. Using a pooled time-series analysis of data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 (n = 11,324), we examine racial-ethnic differences in maternal parenting stress, with a focus on structural and cultural explanations and variations by nativity and child age. In kindergarten, black mothers, albeit U.S.-born only, report more parenting stress than white mothers due to structural disadvantages and authoritarian parenting values. The black-white gap increases from kindergarten to third grade, and in third grade, U.S.-born black mothers' higher stress than white mothers' persists after controlling for structural and parenting factors. Hispanic and Asian mothers, albeit foreign-born only, report more stress than white mothers at both ages due to structural disadvantages and authoritarian values. Despite structural disadvantages, American Indian mothers report less stress.

  2. High-intensity training reduces intermittent hypoxia-induced ER stress and myocardial infarct size.

    Science.gov (United States)

    Bourdier, Guillaume; Flore, Patrice; Sanchez, Hervé; Pepin, Jean-Louis; Belaidi, Elise; Arnaud, Claire

    2016-01-15

    Chronic intermittent hypoxia (IH) is described as the major detrimental factor leading to cardiovascular morbimortality in obstructive sleep apnea (OSA) patients. OSA patients exhibit increased infarct size after a myocardial event, and previous animal studies have shown that chronic IH could be the main mechanism. Endoplasmic reticulum (ER) stress plays a major role in the pathophysiology of cardiovascular disease. High-intensity training (HIT) exerts beneficial effects on the cardiovascular system. Thus, we hypothesized that HIT could prevent IH-induced ER stress and the increase in infarct size. Male Wistar rats were exposed to 21 days of IH (21-5% fraction of inspired O2, 60-s cycle, 8 h/day) or normoxia. After 1 wk of IH alone, rats were submitted daily to both IH and HIT (2 × 24 min, 15-30m/min). Rat hearts were either rapidly frozen to evaluate ER stress by Western blot analysis or submitted to an ischemia-reperfusion protocol ex vivo (30 min of global ischemia/120 min of reperfusion). IH induced cardiac proapoptotic ER stress, characterized by increased expression of glucose-regulated protein kinase 78, phosphorylated protein kinase-like ER kinase, activating transcription factor 4, and C/EBP homologous protein. IH-induced myocardial apoptosis was confirmed by increased expression of cleaved caspase-3. These IH-associated proapoptotic alterations were associated with a significant increase in infarct size (35.4 ± 3.2% vs. 22.7 ± 1.7% of ventricles in IH + sedenary and normoxia + sedentary groups, respectively, P < 0.05). HIT prevented both the IH-induced proapoptotic ER stress and increased myocardial infarct size (28.8 ± 3.9% and 21.0 ± 5.1% in IH + HIT and normoxia + HIT groups, respectively, P = 0.28). In conclusion, these findings suggest that HIT could represent a preventive strategy to limit IH-induced myocardial ischemia-reperfusion damages in OSA patients. Copyright © 2016 the American Physiological Society.

  3. Stress Intensity of Delamination in a Sintered-Silver Interconnection: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    DeVoto, D. J.; Paret, P. P.; Wereszczak, A. A.

    2014-08-01

    In automotive power electronics packages, conventional thermal interface materials such as greases, gels, and phase-change materials pose bottlenecks to heat removal and are also associated with reliability concerns. The industry trend is toward high thermal performance bonded interfaces for large-area attachments. However, because of coefficient of thermal expansion mismatches between materials/layers and resultant thermomechanical stresses, adhesive and cohesive fractures could occur, posing a reliability problem. These defects manifest themselves in increased thermal resistance. This research aims to investigate and improve the thermal performance and reliability of sintered-silver for power electronics packaging applications. This has been experimentally accomplished by the synthesis of large-area bonded interfaces between metalized substrates and copper base plates that have subsequently been subjected to thermal cycles. A finite element model of crack initiation and propagation in these bonded interfaces will allow for the interpretation of degradation rates by a crack-velocity (V)-stress intensity factor (K) analysis. A description of the experiment and the modeling approach are discussed.

  4. Effect of elastic anisotropy of crystal grain on stress intensity factor

    International Nuclear Information System (INIS)

    Kamaya, Masayuki

    2002-01-01

    The stress intensity factor (SIF) is used widely for evaluating integrity of cracked components. Usually, the SIF obtained under isotropic elastic conditions is used for the evaluations. Although, macroscopic elastic behaviors of polycrystal materials can be considered isotropic, each crystal has anisotropic elastic properties. This implies that if the crack size is small and the influence of anisotropic elastic properties on the stress around cracks is significant, the SIF evaluated under anisotropic elastic conditions may differ from the SIF obtained under isotropic elastic conditions. In the present study, the effect of anisotropic elasticity on the SIF was evaluated by using the finite element analysis (FEA). First, the SIF of semi-circular cracks located in a single crystal was evaluated. It was found that the SIF is affected crystal orientation. Secondly, FEA using a polycrystal model was performed. It was found that the change in the SIF was caused by crack tip crystal orientation as well as the deformation constraint from neighboring crystals. Finally, the statistical tendency of change in the SIF caused by the anisotropic elastic properties and the relationship with crack size were examined. The influence of the local SIF on crack growth behavior is also discussed. (author)

  5. Effect of elastic anisotropy of crystal grain on stress intensity factor

    Energy Technology Data Exchange (ETDEWEB)

    Kamaya, Masayuki [Inst. of Nuclear Safety System Inc., Mihama, Fukui (Japan)

    2002-09-01

    The stress intensity factor (SIF) is used widely for evaluating integrity of cracked components. Usually, the SIF obtained under isotropic elastic conditions is used for the evaluations. Although, macroscopic elastic behaviors of polycrystal materials can be considered isotropic, each crystal has anisotropic elastic properties. This implies that if the crack size is small and the influence of anisotropic elastic properties on the stress around cracks is significant, the SIF evaluated under anisotropic elastic conditions may differ from the SIF obtained under isotropic elastic conditions. In the present study, the effect of anisotropic elasticity on the SIF was evaluated by using the finite element analysis (FEA). First, the SIF of semi-circular cracks located in a single crystal was evaluated. It was found that the SIF is affected crystal orientation. Secondly, FEA using a polycrystal model was performed. It was found that the change in the SIF was caused by crack tip crystal orientation as well as the deformation constraint from neighboring crystals. Finally, the statistical tendency of change in the SIF caused by the anisotropic elastic properties and the relationship with crack size were examined. The influence of the local SIF on crack growth behavior is also discussed. (author)

  6. Development of a screening measure of stress for parents of children hospitalised in a Paediatric Intensive Care Unit.

    Science.gov (United States)

    Rodríguez-Rey, Rocío; Alonso-Tapia, Jesús

    2016-08-01

    Having a child admitted to intensive care is a highly stressful experience for parents; however there is a lack of screening instruments of parental stress in that context, which would be useful for both, research and clinical purposes. (1) To validate a brief measure of parental stress based on the Parental Stressor Scale: Paediatric Intensive Care Unit (PSS:PICU), (2) to study which environmental factors of the PICU are more stressful in a sample of Spanish parents, and (3) to study which variables are related to higher levels of stress among this group. 196 Spanish parents completed the Abbreviated PSS: PICU (A-PSS:PICU) and a general stress scale (the Perceived Stress Scale) upon their child's discharge to test the convergent validity of the tool. Three months later, they were assessed anxiety and depression using the Hospital Anxiety and Depression Scale, and posttraumatic stress with the Davidson Trauma Scale in order to test the predictive validity of the A-PSS:PICU. Two factors emerged from Confirmatory Factor Analyses, (1) stress due to child's condition and (2) stress related to PICU's staff. The A-PSS:PICU showed adequate reliability and convergent and predictive validity. The most stressful aspects were the behaviours and emotional responses of their child and the loss of their parental role. Age, gender, child's condition, length of admission, spiritual beliefs, and mechanical ventilation were associated to parental stress scores. The A-PSS:PICU is a reliable and valid measure. Parental stress should be screened during a child's PICU admission to identify parents at risk of post-discharge distress. Copyright © 2016 Australian College of Critical Care Nurses Ltd. Published by Elsevier Ltd. All rights reserved.

  7. Laplace-SGBEM analysis of the dynamic stress intensity factors and the dynamic T-stress for the interaction between a crack and auxetic inclusions

    Science.gov (United States)

    Kwon, Kibum

    A dynamic analysis of the interaction between a crack and an auxetic (negative Poisson ratio)/non-auxetic inclusion is presented. The two most important fracture parameters, namely the stress intensity factors and the T-stress are analyzed by using the symmetric Galerkin boundary element method in the Laplace domain for three different models of crack-inclusion interaction. To investigate the effects of auxetic inclusions on the fracture behavior of composites reinforced by this new type of material, comparisons of the dynamic stress intensity factors and the dynamic T-stress are made between the use of auxetic inclusions as opposed to the use of traditional inclusions. Furthermore, the technique presented in this research can be employed to analyze for the interaction between a crack and a cluster of auxetic/non-auxetic inclusions. Results from the latter models can be employed in crack growth analysis in auxetic-fiber-reinforced composites.

  8. The Value of Peer Feedback Opportunities for Students in Writing Intensive Classes

    Science.gov (United States)

    Kennette, Lynne N.; Frank, Nichole M.

    2013-01-01

    The present study was conducted to examine the usefulness of peer feedback on APA-style research papers in a writing-intensive class. Subsequent to APA training, students were asked to review and provide feedback on a classmate's APA-style research report for both content and formatting. Performance on this research report was then compared to…

  9. Post-stress recovery of pituitary-adrenal hormones and glucose, but not the response during exposure to the stressor, is a marker of stress intensity in highly stressful situations.

    Science.gov (United States)

    Márquez, Cristina; Belda, Xavier; Armario, Antonio

    2002-02-01

    Acute immobilization in male rats elicited the same ACTH, corticosterone and glucose response as foot shock when measured immediately after stress. However, post-stress recovery of plasma ACTH, corticosterone and glucose levels were delayed in immobilized versus shocked rats. Similarly, stress-induced anorexia was much greater in the former animals. All these data suggest that post-stress speed of recovery of some physiological variables is positively related to stressor intensity and could be used to evaluate it.

  10. Intermittent fasting modulates IgA levels in the small intestine under intense stress: a mouse model.

    Science.gov (United States)

    Lara-Padilla, Eleazar; Godínez-Victoria, Marycarmen; Drago-Serrano, Maria Elisa; Reyna-Garfias, Humberto; Arciniega-Martínez, Ivonne Maciel; Abarca-Rojano, Edgar; Cruz-Hernández, Teresita Rocío; Campos-Rodríguez, Rafael

    2015-08-15

    Intermittent fasting prolongs the lifespan and unlike intense stress provides health benefits. Given the role of the immunoglobulin A (IgA) in the intestinal homeostasis, the aim of this study was to assess the impact of intermittent fasting plus intense stress on secretory IgA (SIgA) production and other mucosal parameters in the duodenum and ileum. Two groups of six mice, with intermittent fasting or fed ad libitum for 12weeks, were submitted to a session of intense stress by a bout of forced swimming. Unstressed ad libitum fed or intermittently fasted groups were included as controls. After sacrifice, we evaluated intestinal SIgA and plasma adrenal hormones, lamina propria IgA+ plasma-cells, mRNA expression of polymeric immunoglobulin receptor, α- and J-chains in the liver and intestinal mucosa, as well as pro- (tumor necrosis factor-α, interleukin-6 and Interferon-γ) and anti- (interleukin-2, -4, -10 and transforming growth factor-β) inflammatory cytokines in mucosal samples. Under intense stress, intermittent fasting down- or up-modulated the levels of most parameters in the duodenum and ileum, respectively while up-regulated corticosterone levels without affecting epinephrine. Our data suggest intermittent fasting plus intense stress elicited neuroendocrine pathways that differentially controlled IgA and pIgR expression in duodenum and ileum. These findings provide experimental foundations for a presumable impact of intermittent fasting under intense stress on the intestinal homeostasis or inflammation by triggering or reducing the IgA production in ileum or duodenum respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Effect of Trailing Intensive Cooling on Residual Stress and Welding Distortion of Friction Stir Welded 2060 Al-Li Alloy

    Science.gov (United States)

    Ji, Shude; Yang, Zhanpeng; Wen, Quan; Yue, Yumei; Zhang, Liguo

    2018-04-01

    Trailing intensive cooling with liquid nitrogen has successfully applied to friction stir welding of 2 mm thick 2060 Al-Li alloy. Welding temperature, plastic strain, residual stress and distortion of 2060 Al-Li alloy butt-joint are compared and discussed between conventional cooling and trailing intensive cooling using experimental and numerical simulation methods. The results reveal that trailing intensive cooling is beneficial to shrink high temperature area, reduce peak temperature and decrease plastic strain during friction stir welding process. In addition, the reduction degree of plastic strain outside weld is smaller than that inside weld. Welding distortion presents an anti-saddle shape. Compared with conventional cooling, the reductions of welding distortion and longitudinal residual stresses of welding joint under intense cooling reach 47.7 % and 23.8 %, respectively.

  12. Effects of Light Intensity on Growth, Anti-Stress Ability and Immune Function in Yellow Feathered Broilers

    Directory of Open Access Journals (Sweden)

    YL Guo

    Full Text Available ABSTRACT An experiment was conducted to investigate the effects of light intensity on growth, anti-stress ability, and immune function of yellow feathered broilers. A total of 480 one-day-old male Lingnan yellow feathered broilers were randomly allocated to 4 treatments based on light intensity (1, 5, 20 and 80 lx with 8 replicates of 15 chicks each. The experiment lasted for 63 days. Compared with those under high light intensity, broilers exposed to low light intensity had higher (p<0.05 total antioxidant capacity (T-AOC, glutathione peroxidase (GSH-Px, a-Naphthylacetate esterase (ANAE+, antibody titer, but lower (p<0.05 malonaldehyde (MDA levels and heterophil/lymphocyte ratio (H/L. There was a linear effect for T-AOC(p=0.002, GSH-Px(p≤0.047, MDA (p=0.003, H/L(p≤0.014, ANAE+ (p≤0.044, and antibody titer (p≤0.021 with T-AOC, GSH-Px, ANAE+, and antibody titer increased significantly as light intensity decreased, whereas MDA and H/L were decreased with the decrease in light intensity. These results suggested that broilers under low light intensity could have similar performance, better anti-stress ability, stronger immune function, and more efficient in energy usage as compared with those exposed to high light intensity environment.

  13. Labour-Intensive Services and Changes in Value Added Tax Revenue

    Directory of Open Access Journals (Sweden)

    Krzikallova Katerina

    2016-03-01

    Full Text Available VAT rates have gradually become an important fiscal policy tool of of EU member states. This paper quantifies the influence on the VAT revenue of the potential transfer of selected labour intensive services from the standard to a reduced VAT rate in the Czech Republic. The data used for the analysis were obtained by a questionnaire, as well as through research performed at the General Financial Directorate and the Czech Statistical Office. To analyze the data, a comparison analysis and descriptive statistical methods were used. The change in VAT rate would cause a decrease in VAT revenue up to 1.6 billion CZK per year, but it would also bring positive effects, especially in the business development of the suppliers of labor intensive services. It could also prevent a price increase during the planned introduction of the e-sales system in restaurants.

  14. Stress-intensity factors for a thick-walled cylinder containing an annular imbedded or external or internal surface crack

    Science.gov (United States)

    Erdol, R.; Erdogan, F.

    1976-01-01

    The elastostatic axisymmetric problem for a long thick-walled cylinder containing a ring-shaped internal or edge crack is considered. Using the standard transform technique the problem is formulated in terms of an integral equation which has a simple Cauchy kernel for the internal crack and a generalized Cauchy kernel for the edge crack as the dominant part. As examples the uniform axial load and the steady-state thermal stress problems have been solved and the related stress intensity factors have been calculated. Among other findings the results show that in the cylinder under uniform axial stress containing an internal crack the stress intensity factor at the inner tip is always greater than that at the outer tip for equal net ligament thicknesses and in the cylinder with an edge crack which is under a state of thermal stress the stress intensity factor is a decreasing function of the crack depth, tending to zero as the crack depth approaches the wall thickness.

  15. Predischarge stress test after myocardial infarction in the old stage : results and prognostic value

    NARCIS (Netherlands)

    P.M. Fioretti (Paolo); J.W. Deckers (Jaap); R.W. Brower (Ronald); M.L. Simoons (Maarten); J.A.J.M. Beelen; P.G. Hugenholtz (Paul)

    1984-01-01

    textabstractThe aim of this study was to evaluate the results of predischarge stress testing in the elderly, and to assess the prognostic value of the test during one-year follow-up. The database consisted of 48 patients older than 64 years of age and 109 patients 55-64 years of age, who survived

  16. Gas Exchanges and Dehydration in Different Intensities of Conditioning in Tifton 85 Bermudagrass: Nutritional Value during Hay Storage

    Directory of Open Access Journals (Sweden)

    M. Pasqualotto

    2015-06-01

    Full Text Available The present study aimed at evaluating the intensity of Tifton 85 conditioning using a mower conditioner with free-swinging flail fingers and storage times on dehydration curve, fungi presence, nutritional value and in vitro digestibility of Tifton 85 bermudagrass hay dry matter (DM. The dehydration curve was determined in the whole plant for ten times until the baling. The zero time corresponded to the plant before cutting, which occurred at 11:00 and the other collections were carried out at 8:00, 10:00, 14:00, and 16:00. The experimental design was randomised blocks with two intensities of conditioning (high and low and ten sampling times, with five replications. The high and low intensities related to adjusting the deflector plate of the free iron fingers (8 and 18 cm. In order to determine gas exchanges during Tifton 85 bermudagrass dehydration, there were evaluations of mature leaves, which were placed in the upper middle third of each branch before the cutting, at every hour for 4 hours. A portable gas analyser was used by an infrared IRGA (6400xt. The analysed variables were photosynthesis (A, stomatal conductance (gs, internal CO2 concentration (Ci, transpiration (T, water use efficiency (WUE, and intrinsic water use efficiency (WUEi. In the second part of this study, the nutritional value of Tifton 85 hay was evaluated, so randomised blocks were designed in a split plot through time, with two treatments placed in the following plots: high and low intensity of cutting and five different time points as subplots: cutting (additional treatment, baling and after 30, 60, and 90 days of storage. Subsequently, fungi that were in green plants as well as hay were determined and samples were collected from the grass at the cutting period, during baling, and after 30, 60, and 90 days of storage. It was observed that Tifton 85 bermudagrass dehydration occurred within 49 hours, so this was considered the best time for drying hay. Gas exchanges were

  17. Counterbalancing work-related stress? Work engagement among intensive care professionals.

    Science.gov (United States)

    van Mol, Margo M C; Nijkamp, Marjan D; Bakker, Jan; Schaufeli, Wilmar B; Kompanje, Erwin J O

    2018-07-01

    Working in an Intensive Care Unit (ICU) is increasingly complex and is also physically, cognitively and emotionally demanding. Although the negative emotions of work-related stress have been well studied, the opposite perspective of work engagement might also provide valuable insight into how these emotional demands may be countered. This study focused on the work engagement of ICU professionals and explored the complex relationship between work engagement, job demands and advantageous personal resources. This was a cross-sectional survey study among ICU professionals in a single-centre university hospital. Work engagement was measured by the Utrecht Work Engagement Scale, which included items about opinions related to the respondent's work environment. Additionally, 14 items based on the Jefferson Scale of Physician Empathy were included to measure empathic ability. A digital link to the questionnaire was sent in October 2015 to a population of 262 ICU nurses and 53 intensivists. The overall response rate was 61% (n=193). Work engagement was negatively related both to cognitive demands among intensivists and to emotional demands among ICU nurses. No significant relationship was found between work engagement and empathic ability; however, agreeableness, conscientiousness, and emotional stability were highly correlated with work engagement. Only the number of hours worked per week remained as a confounding factor, with a negative effect of workload on work engagement after controlling for the effect of weekly working hours. Work engagement counterbalances work-related stress reactions. The relatively high workload in ICUs, coupled with an especially heavy emotional burden, may be acknowledged as an integral part of ICU work. This workload does not affect the level of work engagement, which was high for both intensivists and nurses despite the known high job demands. Specific factors that contribute to a healthy and successful work life among ICU professionals need

  18. The five-factor model of personality, work stress and professional quality of life in neonatal intensive care unit nurses.

    Science.gov (United States)

    Barr, Peter

    2018-06-01

    The study aim was to determine the direct and indirect relations of the five-factor model of personality traits and work stress with professional quality of life in neonatal nurses. Neonatal intensive care nursing has positive and negative effects on neonatal nurses' psychological well-being. Although individual and situational factors interact to influence professional quality of life, there have been few studies of these relationships in neonatal nurses. A cross-sectional study conducted in 2016. Self-report questionnaires were used to measure professional quality of life (burnout, secondary traumatic stress and compassion satisfaction), five-factor model of personality traits (neuroticism, agreeableness, extraversion, conscientiousness and openness) and work stress (role ambiguity, role conflict and role overload). One hundred and forty (34%) of 405 eligible neonatal nurses provided the data. After controlling for work stress, neuroticism and agreeableness were related to burnout, neuroticism was related to secondary traumatic stress, and extraversion was related to compassion satisfaction. Work stress controlled for personality traits was related to burnout and secondary traumatic stress, but not to compassion satisfaction. Neuroticism moderated the effect of work stress on secondary traumatic stress and agreeableness and openness moderated the effect of work stress on compassion satisfaction. Work stress mediated the effect of neuroticism and extraversion on burnout and the effects of extraversion and conscientiousness on compassion satisfaction. Strategies to reduce work stress may not lessen burnout and secondary traumatic stress or increase compassion satisfaction in neonatal nurses who are prone to high neuroticism, low agreeableness and low extraversion. © 2018 John Wiley & Sons Ltd.

  19. Posttraumatic stress disorder (PTSD) in children after paediatric intensive care treatment compared to children who survived a major fire disaster

    NARCIS (Netherlands)

    Bronner, M.B.; Knoester, H.; Bos, AP; Last, B.F.; Grootenhuis, M.A.

    2008-01-01

    Background: The goals were to determine the presence of posttraumatic stress disorder (PTSD) in children after paediatric intensive care treatment, to identify risk factors for PTSD, and to compare this data with data from a major fire disaster in the Netherlands. Methods: Children completed the

  20. Stress Intensity Factors of Slanted Cracks in Bi-Material Plates

    Science.gov (United States)

    Ismail, Al Emran; Azhar Kamarudin, Kamarul; Nor, Nik Hisyamudin Muhd

    2017-10-01

    In this study, the stress intensity factors (SIF) of slanted cracks in bi-material plates subjected to mode I loading is numerically solved. Based on the literature survey, tremendous amount of research works are available studying the normal cracks in both similar and dissimilar plates. However, lack of SIF behavior for slanted cracks especially when it is embedded in bi-material plates. The slanted cracks are then modelled numerically using ANSYS finite element program. Two plates of different in mechanical properties are firmly bonded obliquely and then slanted edge cracks are introduced at the lower inclined edge. Isoparametric singular element is used to model the crack tip and the SIF is determined which is based on the domain integral method. Three mechanical mismatched and four slanted angles are used to model the cracks. According to the present results, the effects of mechanical mismatch on the SIF for normal cracks are not significant. However, it is played an important role when slanted angles are introduced. It is suggested that higher SIF can be obtained when the cracks are inclined comparing with the normal cracks. Consequently, accelerating the crack growth at the interface between two distinct materials.

  1. Cellular Stress Response Gene Expression During Upper and Lower Body High Intensity Exercises.

    Science.gov (United States)

    Kochanowicz, Andrzej; Sawczyn, Stanisław; Niespodziński, Bartłomiej; Mieszkowski, Jan; Kochanowicz, Kazimierz; Żychowska, Małgorzata

    2017-01-01

    The aim was to compare the effect of upper and lower body high-intensity exercise on chosen genes expression in athletes and non-athletes. Fourteen elite male artistic gymnasts (EAG) aged 20.6 ± 3.3 years and 14 physically active men (PAM) aged 19.9 ± 1.0 years performed lower and upper body 30 s Wingate Tests. Blood samples were collected before, 5 and 30 minutes after each effort to assess gene expression via PCR. Significantly higher mechanical parameters after lower body exercise was observed in both groups, for relative power (8.7 ± 1.2 W/kg in gymnasts, 7.2 ± 1.2 W/kg in controls, p = 0.01) and mean power (6.7 ± 0.7 W/kg in gymnasts, 5.4 ± 0.8 W/kg in controls, p = 0.01). No differences in lower versus upper body gene expression were detected for all tested genes as well as between gymnasts and physical active man. For IL-6 m-RNA time-dependent effect was observed. Because of no significant differences in expression of genes associated with cellular stress response the similar adaptive effect to exercise may be obtained so by lower and upper body exercise.

  2. Evaluation of stress intensity factors for bi-material interface cracks using displacement jump methods

    Science.gov (United States)

    Nehar, K. C.; Hachi, B. E.; Cazes, F.; Haboussi, M.

    2017-12-01

    The aim of the present work is to investigate the numerical modeling of interfacial cracks that may appear at the interface between two isotropic elastic materials. The extended finite element method is employed to analyze brittle and bi-material interfacial fatigue crack growth by computing the mixed mode stress intensity factors (SIF). Three different approaches are introduced to compute the SIFs. In the first one, mixed mode SIF is deduced from the computation of the contour integral as per the classical J-integral method, whereas a displacement method is used to evaluate the SIF by using either one or two displacement jumps located along the crack path in the second and third approaches. The displacement jump method is rather classical for mono-materials, but has to our knowledge not been used up to now for a bi-material. Hence, use of displacement jump for characterizing bi-material cracks constitutes the main contribution of the present study. Several benchmark tests including parametric studies are performed to show the effectiveness of these computational methodologies for SIF considering static and fatigue problems of bi-material structures. It is found that results based on the displacement jump methods are in a very good agreement with those of exact solutions, such as for the J-integral method, but with a larger domain of applicability and a better numerical efficiency (less time consuming and less spurious boundary effect).

  3. New stress intensity factor solutions for an elliptical crack in a plate

    International Nuclear Information System (INIS)

    Delliou, P.L.; Barthelet, B.

    2005-01-01

    Crack assessment in engineering structures relies first on accurate evaluation of the stress intensity factors. In recent years, a large work has been conducted in France by the Atomic Energy Commission to develop influence coefficients for surface cracks in pipes. However, the problem of embedded cracks in plates (and pipes) which is also of practical importance has not received so much attention. Presently, solutions for elliptical cracks are available either in infinite solid with a polynomial distribution of normal loading or in plate, but restricted to constant or linearly varying tension. This paper presents the work conducted at EDF R and D to obtain influence coefficients for plates containing an elliptical crack with a wide range of the parameters : relative size (2a/t ratio), shape (a/c ratio) and free surface proximity (a/d ratio where d is the distance from the center of the ellipse to the closest free surface). These coefficients were developed through extensive 3D finite element calculations : 200 geometrical configurations were modeled, each containing from 18000 to 26000 nodes. The limiting case of the tunnel crack (a/c = 0) was also analyzed with 2D finite element calculation (50 geometrical configurations). The accuracy of the results was checked by comparison with analytical solutions for infinite solids and, when possible, with solutions for finite-thickness plates (generally loaded in constant tension). (authors)

  4. Comparision the value of detecting myocardial viability between low dose dobutamine stress MRI and echocardiography

    International Nuclear Information System (INIS)

    He Yi; Zhang Zhaoqi; Yu Wei; Miao Cuilian; Zhao Yike; Yan Zixu

    2006-01-01

    Objective: To Compare the diagnostic value between low dose dobutamine stress transthrotic echocardiography and low dose dobutamine stress MRI in detecting myocardial viability of chronic myocardial infarction. Methods: Rest and low dose dobutamine (5, 10 μg·kg -1 ·min -1 ) stress transthrotic echocardiography and cine-MRI were performed in 30 patients with chronic myocardial infarction. 24 patients underwent successful revascularization and 10 of them underwent another rest cine-MRI study to assess segmental myocardial functional recovery. Left ventricular were divided into 16 segments, the criteria of viability in different techniques is: MRI: dobutamine induced systolic wall thickening was ≥2 mm in akinetic or diskinetic segments at rest; Echocardiography: wall motion score reduced at least 1 after dobutamine stress in akinetic or' diskinetic segments at rest. Results: One hundren and eight segments showed wall motion abnormalities of 30 patients, 65 and 56 segments shows positive reaction, 43 and 52 segments shows negativereaction in MRI and echocardiography after dobutamine stress respectively. Kappa value of the two techniques is 0.75, concordance in both techniques is 88%. Twenty-four segments showed functional recovery, 14 segments remained dysfunction 3-6 months after revascularization, the sensitivity, specificity and accuracy of detecting myocardial viability in chronic myocardial infarction in MRI and echocardiography is 95.8% vs 79.2% (P>0.05), 85.7% vs 85.7% (P>0.05), 92.1% vs 81.6% (P>0.05) respectively. The sensitivity and accuracy of MRI is a little higher. Conclusion: The ability of detecting myocardial viability by both low dose dobutamine stress transthrotic echocardiography and low dose dobutamine stress MRI is similer, the sensitivity and accuracy of MRI is a little higher. (authors)

  5. Identifying and Clarifying Values and Reason Statements that Promote Effective Food Parenting Practices, Using Intensive Interviews

    Science.gov (United States)

    Beltran, Alicia; Hingle, Melanie D.; Knesek, Jessica; O'Connor, Teresia; Baranowski, Janice; Thompson, Debbe; Baranowski, Tom

    2011-01-01

    Objective: Generate and test parents' understanding of values and associated reason statements to encourage effective food parenting practices. Methods: This study was cross-sectional. Sixteen parents from different ethnic groups (African American, white, and Hispanic) living with their 3- to 5-year-old child were recruited. Interested parents…

  6. Stress intensity factors for underclad and through clad defects in a reactor pressure vessel submitted to a pressurised thermal shock

    International Nuclear Information System (INIS)

    Marie, S.; Menager, Y.; Chapuliot, S.

    2005-01-01

    CEA has launched important work on the development of a Stress Intensity Factors compendium for cracks in a Reactor Pressure Vessel (RPV) taking into account the cladding. The work is performed by Finite Element analysis with a parametric mesh for two types of defects (under clad defect and through clad defect) and a wide range of geometrical and material parameters. In addition, an analytical stress solution for Pressurised Thermal Shock (PTS) on the RPV is proposed to allow a complete analytical estimation of the stress intensity factor K I for the PTS problem. The results are validated by comparison with a complete 3D finite element calculation performed on a complex and realistic case study

  7. Efficient computer program EPAS-J1 for calculating stress intensity factors of three-dimensional surface cracks

    International Nuclear Information System (INIS)

    Miyazaki, Noriyuki; Watanabe, Takayuki; Yagawa, Genki.

    1982-03-01

    A finite element computer program EPAS-J1 was developed to calculate the stress intensity factors of three-dimensional cracks. In the program, the stress intensity factor is determined by the virtual crack extension method together with the distorted elements allocated along the crack front. This program also includes the connection elements based on the Lagrange multiplier concept to connect such different kinds of elements as the solid and shell elements, or the shell and beam elements. For the structure including three-dimensional surface cracks, the solid elements are employed only at the neighborhood of a surface crack, while the remainder of the structure is modeled by the shell or beam elements due to the reason that the crack singularity is very local. Computer storage and computational time can be highly reduced with the application of the above modeling technique for the calculation of the stress intensity factors of the three-dimensional surface cracks, because the three-dimensional solid elements are required only around the crack front. Several numerical analyses were performed by the EPAS-J1 program. At first, the accuracies of the connection element and the virtual crack extension method were confirmed using the simple structures. Compared with other techniques of connecting different kinds of elements such as the tying method or the method using anisotropic plate element, the present connection element is found to provide better results than the others. It is also found that the virtual crack extension method provides the accurate stress intensity factor. Furthermore, the results are also presented for the stress intensity factor analyses of cylinders with longitudinal or circumferential surface cracks using the combination of the various kinds of elements together with the connection elements. (author)

  8. High-Intensity Exercise Induced Oxidative Stress and Skeletal Muscle Damage in Postpubertal Boys and Girls: A Comparative Study.

    Science.gov (United States)

    Pal, Sangita; Chaki, Biswajit; Chattopadhyay, Sreya; Bandyopadhyay, Amit

    2018-04-01

    Pal, S, Chaki, B, Chattopadhyay, S, and Bandyopadhyay, A. High-intensity exercise induced oxidative stress and skeletal muscle damage in post-pubertal boys and girls: a comparative study. J Strength Cond Res 32(4): 1045-1052, 2018-The purpose of this study was to examine the sex variation in high-intensity exercise induced oxidative stress and muscle damage among 44 sedentary postpubertal boys and girls through estimation of postexercise release pattern of muscle damage markers like creatine kinase, lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and oxidative stress markers like extent of lipid peroxidation (thiobarbituric acid-reactive substances) and catalase activity. Muscle damage markers like creatine kinase, LDH, ALT, and AST were measured before, immediately after, and 24 and 48 hours after high-intensity incremental treadmill running. Oxidative stress markers like thiobarbituric acid-reactive substances and catalase activity were estimated before and immediately after the exercise. Lipid peroxidation and serum catalase activity increased significantly in both groups after exercise (p exercise level at 24 and 48 hours after exercise in both the sexes, (p exercise, the pattern of postexercise release of these markers were found to be similar in both the groups. Accordingly, it has been concluded from the present investigation that high-intensity exercise induces significant oxidative stress and increases indices of skeletal muscle damage in both postpubertal girls and boys. However, postpubertal girls are relatively better protected from oxidative stress and muscle damage as compared to the boys of similar age and physical activity level. It is further evident that sex difference may not be apparent for all the biomarkers of muscle damage in this age group.

  9. Simultaneous analysis of residual stress and stress intensity factor in a resist after UV-nanoimprint lithography based on electron moiré fringes

    International Nuclear Information System (INIS)

    Wang, Qinghua; Kishimoto, Satoshi

    2012-01-01

    In this study, the residual stress in a resist (PAK01) film and the stress intensity factor (SIF) of an induced crack are simultaneously estimated during ultraviolet nanoimprint lithography (UV-NIL) based on electron moiré fringes. A micro grid in a triangular arrangement on the resist film fabricated by UV-NIL is directly used as the model grid. Electron moiré fringes formed by the interference between the fabricated grid and the electron scan beam are used to measure the displacement distribution around the tip of a crack induced by the residual stress in the resist. The SIF of the crack is estimated using a displacement extrapolation method. The residual strain fields and the corresponding residual stress in the resist film far from the crack are determined and analyzed. This method is effective for evaluating the grid quality fabricated by the UV-NIL technique. (paper)

  10. Intensive skills week for military medical students increases technical proficiency, confidence, and skills to minimize negative stress.

    Science.gov (United States)

    Mueller, Genevieve; Hunt, Bonnie; Wall, Van; Rush, Robert; Molof, Alan; Schoeff, Jonathan; Wedmore, Ian; Schmid, James; Laporta, Anthony

    2012-01-01

    The effects of stress induced cortisol on learning and memory is well documented in the literature.1-3 Memory and learning are enhanced at low levels while high levels are detrimental. Repetitive training in stressful situations enables management of the stress response4 as demonstrated by the high intensity training military members undergo to prepare for tactical situations. Appropriate management of one?s stress response is critical in the medical field, as the negative effects of stress can potentially hinder life-saving procedures and treatments. This also applies to physicians-in-training as they learn and practice triage, emergency medicine, and surgical skills prior to graduation. Rocky Vista University?s Military Medicine Honor?s Track (MMHT) held a week long high-intensity emergency medicine and surgical Intensive Skills Week (ISW), facilitated by military and university physicians, to advance students? skills and maximize training using the Human Worn Partial Surgical Task Simulator (Cut Suit). The short-term goal of the ISW was to overcome negative stress responses to increase confidence, technical and non-technical knowledge, and skill in surgery and emergency medicine in an effort to improve performance as third-year medical students. The long-term goal was to enhance performance and proficiency in residency and future medical practice. The metrics for the short-term goals were the focus of this pilot study. Results show an increase in confidence and decrease in perceived stress as well as statistically significant improvements in technical and non-technical skills and surgical instrumentation knowledge throughout the week. There is a correlative benefit to physician and non-physician military personnel, especially Special Operations Forces (SOF) medical personnel, from developing and implementing similar training programs when live tissue or cadaver models are unavailable or unfeasible. 2012.

  11. The interplay of stress and mowing disturbance for the intensity and importance of plant interactions in dry calcareous grasslands.

    Science.gov (United States)

    Maalouf, Jean-Paul; Le Bagousse-Pinguet, Yoann; Marchand, Lilian; Touzard, Blaise; Michalet, Richard

    2012-09-01

    There is still debate regarding the direction and strength of plant interactions under intermediate to high levels of stress. Furthermore, little is known on how disturbance may interact with physical stress in unproductive environments, although recent theory and models have shown that this interplay may induce a collapse of plant interactions and diversity. The few studies assessing such questions have considered the intensity of biotic interactions but not their importance, although this latter concept has been shown to be very useful for understanding the role of interactions in plant communities. The objective of this study was to assess the interplay between stress and disturbance for plant interactions in dry calcareous grasslands. A field experiment was set up in the Dordogne, southern France, where the importance and intensity of biotic interactions undergone by four species were measured along a water stress gradient, and with and without mowing disturbance. The importance and intensity of interactions varied in a very similar way along treatments. Under undisturbed conditions, plant interactions switched from competition to neutral with increasing water stress for three of the four species, whereas the fourth species was not subject to any significant biotic interaction along the gradient. Responses to disturbance were more species-specific; for two species, competition disappeared with mowing in the wettest conditions, whereas for the two other species, competition switched to facilitation with mowing. Finally, there were no significant interactions for any species in the disturbed and driest conditions. At very high levels of stress, plant performances become too weak to allow either competition or facilitation and disturbance may accelerate the collapse of interactions in dry conditions. The results suggest that the importance and direction of interactions are more likely to be positively related in stressful environments.

  12. Predicting Calcium Values for Gastrointestinal Bleeding Patients in Intensive Care Unit Using Clinical Variables and Fuzzy Modeling

    Directory of Open Access Journals (Sweden)

    G Khalili-Zadeh-Mahani

    2016-07-01

    Full Text Available Introduction: Reducing unnecessary laboratory tests is an essential issue in the Intensive Care Unit. One solution for this issue is to predict the value of a laboratory test to specify the necessity of ordering the tests. The aim of this paper was to propose a clinical decision support system for predicting laboratory tests values. Calcium laboratory tests of three categories of patients, including upper and lower gastrointestinal bleeding, and unspecified hemorrhage of gastrointestinal tract, have been selected as the case studies for this research. Method: In this research, the data have been collected from MIMIC-II database. For predicting calcium laboratory values, a Fuzzy Takagi-Sugeno model is used and the input variables of the model are heart rate and previous value of calcium laboratory test. Results: The results showed that the values of calcium laboratory test for the understudy patients were predictable with an acceptable accuracy. In average, the mean absolute errors of the system for the three categories of the patients are 0.27, 0.29, and 0.28, respectively. Conclusion: In this research, using fuzzy modeling and two variables of heart rate and previous calcium laboratory values, a clinical decision support system was proposed for predicting laboratory values of three categories of patients with gastrointestinal bleeding. Using these two clinical values as input variables, the obtained results were acceptable and showed the capability of the proposed system in predicting calcium laboratory values. For achieving better results, the impact of more input variables should be studied. Since, the proposed system predicts the laboratory values instead of just predicting the necessity of the laboratory tests; it was more generalized than previous studies. So, the proposed method let the specialists make the decision depending on the condition of each patient.

  13. Normative cultural values and the experiences of Mexican-American mothers in the neonatal intensive care unit.

    Science.gov (United States)

    Cleveland, Lisa M; Horner, Sharon D

    2012-04-01

    To explore the experiences of Mexican-American mothers who have had infants in the neonatal intensive care unit (NICU). A convenience sample of 15 English-speaking, Mexican-American women was interviewed. The study used an exploratory qualitative approach. Data collection was conducted through audiotaped, transcribed, semistructured, individual interviews and field notes. The 5 normative cultural values for Latino families-(1) simpatia, (2) personalismo, (3) respeto, (4) familismo, and (5) fatalismo-were used as a sensitizing framework to guide data interpretation. The women's discussions of their NICU experiences clearly reflect the 5 normative Latino cultural values. Positive and negative exemplars of these values are provided as evidence. These findings can be used to inform nursing care provided for Mexican-American mothers and their infants by assisting nurses to customize care to meet the cultural needs of this population.

  14. The Predictive Value of Scores Used in Intensive Care Unit for Burn Patients Prognostic.

    Science.gov (United States)

    Novac, M; Dragoescu, Alice; Stanculescu, Andreea; Duca, Lucica; Cernea, Daniela

    2014-01-01

    Statistical evaluation of the prognosis of burned patients based on the analysis of prognostic scores as quickly and easily obtainable that track the evolution of burned patient in ICU. Material / Methods: The prospective study included 92 patients were performed with severe burns on 35-67% body surface large area, aiming to establish a cut-off score for each studied and statistically significant prognostic parameter for assessing the risk of mortality. The control group was represented by 20 patients with burns on the body surface of 0.05) sex (male / female), but we had p cut-off. Quantification of variables by calculating the area under the ROC curve (AUC), sensitivity and sensitivity, positive predictive value (PPV) and negative predictive value (NPV), allowed a better appreciation of these prognostic scores. These systems applicable to the burned patient scores, making a cut-off of each index / mortality probability score, he can manifest usefulness in medical decision making process and strategy to reduce the risk of death in patients with severe burns.

  15. Myocardial 201Tl washout after combined dipyridamole submaximal exercise stress: Reference values from different patient groups

    International Nuclear Information System (INIS)

    Fridrich, L.

    1989-01-01

    Dipyridamole stress is favorable in patients unable to exercise maximally for 201 Tl myocardial scintigraphy. Aside from an analysis of uptake defects, proper washout analysis can be limited by heart rate variations when isolated dipyridamole stress is used. Heart rate standardized 201 Tl washout kinetics after a combined dipyridamole and submaximal exercise stress protocol (CDSE), feasible in elderly patients as well as in patients with peripheral artery disease, were therefore studied to investigate the 201 Tl washout after CDSE in differently defined patient groups: Group I comprised 19 patients with documented heart disease and angiographically excluded coronary artery disease (CAD); group II contained 17 patients with a very low likelihood of CAD determined by both normal exercise radionuclide ventriculography and normal 201 Tl uptake. Group III comprised 56 patients with a 50% pretest likelihood of CAD but normal 201 Tl uptake. Mean washout values were nearly identical in all groups. Despite similar uptake patterns, however, washout standardized by CDSE was significantly lower than the normal washout values after maximal treadmill exercise. Thus an obviously lower 201 Tl washout after CDSE than after maximal treadmill exercise must be considered if washout analysis criteria after dipyridamole are applied to evaluate ischemic heart disease. Nevertheless, heart rate elevation achieved by additional submaximal exercise stress seems necessary, adequate and clinically safe for standardisation of washout analysis in dipyridamole 201 Tl scintigraphy. (orig.)

  16. Review of family relational stress and pediatric asthma: the value of biopsychosocial systemic models.

    Science.gov (United States)

    Wood, Beatrice L; Miller, Bruce D; Lehman, Heather K

    2015-06-01

    Asthma is the most common chronic disease in children. Despite dramatic advances in pharmacological treatments, asthma remains a leading public health problem, especially in socially disadvantaged minority populations. Some experts believe that this health gap is due to the failure to address the impact of stress on the disease. Asthma is a complex disease that is influenced by multilevel factors, but the nature of these factors and their interrelations are not well understood. This paper aims to integrate social, psychological, and biological literatures on relations between family/parental stress and pediatric asthma, and to illustrate the utility of multilevel systemic models for guiding treatment and stimulating future research. We used electronic database searches and conducted an integrated analysis of selected epidemiological, longitudinal, and empirical studies. Evidence is substantial for the effects of family/parental stress on asthma mediated by both disease management and psychobiological stress pathways. However, integrative models containing specific pathways are scarce. We present two multilevel models, with supporting data, as potential prototypes for other such models. We conclude that these multilevel systems models may be of substantial heuristic value in organizing investigations of, and clinical approaches to, the complex social-biological aspects of family stress in pediatric asthma. However, additional systemic models are needed, and the models presented herein could serve as prototypes for model development. © 2015 Family Process Institute.

  17. The role of aerobic fitness and exercise intensity on endurance performance in uncompensable heat stress conditions.

    Science.gov (United States)

    Périard, Julien D; Caillaud, Corinne; Thompson, Martin W

    2012-06-01

    The aim of this study was to examine the influence of aerobic fitness and exercise intensity on the development of thermal and cardiovascular strain in uncompensable heat stress conditions. In three separate trials, eight aerobically trained and eight untrained subjects cycled to exhaustion at 60% (H60%) and 75% (H75%) of maximal oxygen uptake [Formula: see text] in 40°C conditions, and for 60 min at 60% [Formula: see text] in 18°C conditions (CON). Training status had no influence on time to exhaustion between trained (61 ± 10 and 31 ± 9 min) and untrained (58 ± 12 and 26 ± 10 min) subjects (H60% and H75%, respectively). Rectal temperature at exhaustion was also not significantly different between trained (39.8 ± 0.3, 39.3 ± 0.6 and 38.2 ± 0.3°C) and untrained (39.4 ± 0.5, 38.8 ± 0.5 and 38.2 ± 0.4°C) subjects, but was different between trials (H60%, H75% and CON, respectively; P exercise was terminated on reaching the ethics approved rectal temperature limit in four trained subjects in the H60% trial and two in the H75% trial, it is speculated that increased rectal temperature may have further occurred in this cohort. Nonetheless, exhaustion occurred >96% of maximum heart rate in both cohorts and was accompanied by significant declines in stroke volume (15-26%), cardiac output (5-10%) and mean arterial pressure (9-13%) (P aerobic exercise in the heat in both trained and untrained subjects.

  18. Pain Sensitivity Mediates The Relationship between Stress and Headache Intensity in Chronic Tension-Type Headache

    OpenAIRE

    Stuart Cathcart; Navjot Bhullar; Maarten Immink; Chris Della Vedova; John Hayball

    2012-01-01

    BACKGROUND: A central model for chronic tension-type headache (CTH) posits that stress contributes to headache, in part, by aggravating existing hyperalgesia in CTH sufferers. The prediction from this model that pain sensitivity mediates the relationship between stress and headache activity has not yet been examined.OBJECTIVE: To determine whether pain sensitivity mediates the relationship between stress and prospective headache activity in CTH sufferers.METHOD: Self-reported stress, pain sen...

  19. Not all resources are created equal: COR theory, values, and stress.

    Science.gov (United States)

    Morelli, Neil A; Cunningham, Christopher J L

    2012-01-01

    The common usage of conservation of resources (COR) theory highlights the quantity of resources in explaining stress reactions and responses. To expand the theoretical understanding and explanatory power of COR theory, this study tested the proposition that the perceived importance of an individual's resources is a function of personal values. Using a value framework based on Schwartz (1994), it was expected that values would influence both the appraisal of resource importance and coping behaviors. Results from both student and working samples indicated that while resource importance did not clearly mediate all of the coping outcomes, values did have an influence on the importance an individual assigns to resources. Measurement and theoretical implications related to COR theory are discussed.

  20. Short-term intense exercise training reduces stress markers and alters the transcriptional response to exercise in skeletal muscle.

    Science.gov (United States)

    Hinkley, J Matthew; Konopka, Adam R; Suer, Miranda K; Harber, Matthew P

    2017-03-01

    The purpose of this investigation was to examine the influence of short-term intense endurance training on cycling performance, along with the acute and chronic signaling responses of skeletal muscle stress and stability markers. Ten recreationally active subjects (25 ± 2 yr, 79 ± 3 kg, 47 ± 2 ml·kg -1 ·min -1 ) were studied before and after a 12-day cycling protocol to examine the effects of short-term intense (70-100% V̇o 2max ) exercise training on resting and exercise-induced regulation of molecular factors related to skeletal muscle cellular stress and protein stability. Skeletal muscle biopsies were taken at rest and 3 h following a 20-km cycle time trial on days 1 and 12 to measure mRNA expression and protein content. Training improved ( P stress. The maintenance in the myocellular environment may be due to synthesis of cytoprotective markers, along with enhanced degradation of damage proteins, as training tended ( P short-term intense training enhances protein stability, creating a cellular environment capable of resistance to exercise-induced stress, which may be favorable for adaptation. Copyright © 2017 the American Physiological Society.

  1. Study on the relationship between stress intensity factor and J integral for mixed mode crack with arbitrary inclination based on SBFEM

    International Nuclear Information System (INIS)

    Zhu, C L; Li, J B; Lin, G; Zhong, H

    2010-01-01

    The J integral and the stress intensity factor (SIF) K are both important research objects of fracture mechanics, and are often employed to establish criteria for crackpropagation. The relationship between them has always been a research hotspot. In this paper, the SIF can be obtained conveniently by the scaled boundary finite element method (SBFEM) due to the fact that analytical solution can be obtained along the radial direction for stress singularity problems. The J integral can be solved analytically using the formulae between J and K for mixed mode crack with arbitrary inclination in elastic materials. Moreover, the J integral values obtained by this method are more accurate and convenient than by its definition. Factors that affect the accuracy of SIF and J integral, such as the distance between the crack and outer boundary, size of the discretized elements and partition of the domain into super-elements, are examined.

  2. Negative Affect Intensity and Hostility in Individuals with Alcohol Use Disorder with or without Post-Traumatic Stress Disorder.

    Science.gov (United States)

    Gandelman, Erin; Petrakis, Ismene; Kachadourian, Lorig; Ralevski, Elizabeth

    2018-02-20

    Negative affect intensity and hostility have both been implicated in alcohol use disorders (AUD) and post-traumatic stress disorder (PTSD) when they occur separately, but have neither been compared nor explored among those with dual diagnosis AUD and PTSD. This study is a secondary analysis designed to compare levels of negative affect intensity and hostility among those with AUD to those with dual diagnosis AUD and PTSD. Participants (n = 113) were recruited from the placebo-controlled groups of two distinct 12-week clinical trials (NCT00342563 and NCT00744055). The Short Affect Intensity Scale and Buss-Durkee Hostility Inventory were administered at weeks 0, 4, 8 and 12 to all study participants to assess negative affect intensity and hostility levels, respectively. Dual diagnosis AUD and PTSD individuals showed significantly higher levels of negative affect intensity and hostility than individuals with single diagnosis AUD. These levels remained relatively stable over the course of the study in spite of all study participants showing clinically significant improvements in AUD severity and PTSD symptomology (for those with dual diagnosis). Our results indicate that individuals with dual diagnosis AUD and PTSD have higher levels of negative affect and higher levels of hostility compared to individuals with single diagnosis AUD. In addition, these heightened levels of negative affect intensity and hostility appear to function somewhat independently of diagnosis severity and symptomology improvement. To our knowledge, this is the first study to compare negative affect intensity and hostility levels between single diagnosis AUD and dual diagnosis AUD and PTSD individuals.

  3. Effect of stress hyperglycemia and intensive rehabilitation therapy in non-diabetic hemorrhagic stroke: Korean Stroke Cohort for Functioning and Rehabilitation.

    Science.gov (United States)

    Yoon, J A; Kim, D Y; Sohn, M K; Lee, J; Lee, S-G; Lee, Y-S; Han, E Y; Joo, M C; Oh, G-J; Han, J; Lee, S W; Park, M; Chang, W H; Shin, Y-I; Kim, Y-H

    2016-11-01

    We investigated the effect of stress hyperglycemia on the functional outcomes of non-diabetic hemorrhagic stroke. In addition, we investigated the usefulness of intensive rehabilitation for improving functional outcomes in patients with stress hyperglycemia. Non-diabetic hemorrhagic stroke patients were recruited and divided into two groups: intracerebral hemorrhage (ICH) (n = 165) and subarachnoid hemorrhage (SAH) (n = 156). Each group was divided into non-diabetics with or without stress hyperglycemia. Functional assessments were performed at 7 days and 3, 6 and 12 months after stroke onset. The non-diabetic with stress hyperglycemia groups were again divided into two groups who either received or did not receive intensive rehabilitation treatment. Serial functional outcome was compared between groups. For the ICH group, patients with stress hyperglycemia had worse modified Rankin Scale, National Institutes of Health Stroke Scale, Functional Ambulatory Category and Korean Mini-Mental State Examination scores than patients without stress hyperglycemia. For the SAH group, patients with stress hyperglycemia had worse scores on all functional assessments than patients without stress hyperglycemia at all time-points. After intensive rehabilitation treatment of patients with stress hyperglycemia, the ICH group had better scores on Functional Ambulatory Category and the SAH group had better scores on all functional assessments than patients without intensive rehabilitation treatment. Stress hyperglycemia affects the long-term prognosis of non-diabetic hemorrhagic stroke patients. Among stress hyperglycemia patients, intensive rehabilitation can enhance functional improvement after stroke. © 2016 EAN.

  4. Value of dipyridamole stress 201Tl myocardial SPECT in detecting dysfunction of coronary microcirculation

    International Nuclear Information System (INIS)

    Lou Ying; Jiang Jinqi; Xie Wenhui; Yuan Fang; Wang Tong; Yang Yiqing

    2012-01-01

    Objective: To evaluate the value of dipyridamole stress 201 Tl myocardial SPECT in detecting dysfunction of coronary microcirculation. Methods: Forty-eight patients diagnosed with cardiac syndrome X underwent dipyridamole stress 201 Tl myocardial SPECT. Dipyridamole (0.56 mg/kg) was intravenously injected over 4 min followed by 201 Tl (111 MBq) injection at 2 min after dipyridamole administration. Image was acquired at 10 min and 240 min post-injection and co-analyzed by over two experienced doctors in nuclear medicine after three-dimensional reconstruction. The patients with 'reverse redistribution' underwent repeated dipyridamole stress 201 Tl SPECT after medical therapy for 2 weeks. The clinical symptoms and results of the treadmill exercise test pre-and post-therapy were compared. Results: Forty two patients (42/48, 87.50%) showed segmental defects: 'reverse redistribution' on delayed (240 min) 201 Tl images. After medical treatment, 36 cases of the 42 'reverse redistribution' patients had improvement in both clinical symptoms and treadmill exercise test. Post-treatment 201 Tl imaging showed improvement in 45/49 (91.84%) defect segments. Six of the 42 patients had no improvement in clinical symptoms and/or treadmill exercise test. Post-treatment 201 Tl imaging showed no improvement in all the 7 defect segments on the first scan. Conclusion: Dipyridamole stress 201 Tl myocardial SPECT may be valuable in evaluation of impaired coronary microcirculation associated with cardiac syndrome X. (authors)

  5. The clinical value of adenosine triphosphate stress myocardial perfusion tomography for detecting coronary artery disease

    International Nuclear Information System (INIS)

    Yao Zhiming; He Qing; Qu Wanying; Yu Xue; Han Lijun; Yu Zhiguo; Li Wei; Zeng Xuezhai; Zhu Ming; Zhao Hongshan

    2002-01-01

    Objective: To study the clinical value of adenosine triphosphate stress myocardial perfusion tomography imaging (ATP-MPI) in detection of coronary artery disease (CAD). Methods: There were 278 patients underwent ATP-MPI, 51 patients of them also underwent coronary angiography (CAG). Seventy-three patients underwent stress-rest myocardial perfusion tomography imaging with multi-stage submaximal exercise test (ST-MPI) and CAG serving as control group. Results: 1) Side effects: there were 11 different symptoms and atrioventricular conduction block (10 patients), sinoatrial conduction block (2 patients) occurred during ATP stress. Allopathy or interruption of ATP stress did not happen. 2) The sensitivity and specificity of ATP-MPI in detection of CAD were 97.1% and 82.4%, respectively, and those in detection of ≥50% narrowing coronary artery were 91.0% and 94.7%, respectively. 3) In patients without myocardial infarction, the sensitivity and specificity of ATP-MPI in detection of myocardial ischemia were comparable to those of ST-MPI. Conclusion: ATP-MPI is an accurate, safe modality and is comparable to ST-MPI in the detection of CAD

  6. Profiling nurses' job satisfaction, acculturation, work environment, stress, cultural values and coping abilities: A cluster analysis.

    Science.gov (United States)

    Goh, Yong-Shian; Lee, Alice; Chan, Sally Wai-Chi; Chan, Moon Fai

    2015-08-01

    This study aimed to determine whether definable profiles existed in a cohort of nursing staff with regard to demographic characteristics, job satisfaction, acculturation, work environment, stress, cultural values and coping abilities. A survey was conducted in one hospital in Singapore from June to July 2012, and 814 full-time staff nurses completed a self-report questionnaire (89% response rate). Demographic characteristics, job satisfaction, acculturation, work environment, perceived stress, cultural values, ways of coping and intention to leave current workplace were assessed as outcomes. The two-step cluster analysis revealed three clusters. Nurses in cluster 1 (n = 222) had lower acculturation scores than nurses in cluster 3. Cluster 2 (n = 362) was a group of younger nurses who reported higher intention to leave (22.4%), stress level and job dissatisfaction than the other two clusters. Nurses in cluster 3 (n = 230) were mostly Singaporean and reported the lowest intention to leave (13.0%). Resources should be allocated to specifically address the needs of younger nurses and hopefully retain them in the profession. Management should focus their retention strategies on junior nurses and provide a work environment that helps to strengthen their intention to remain in nursing by increasing their job satisfaction. © 2014 Wiley Publishing Asia Pty Ltd.

  7. Calculation of stress intensity factors using the UNCLE finite element system and their application in fracture mechanics

    International Nuclear Information System (INIS)

    Pearce, J.H.B.

    1978-02-01

    The behaviour of crack-like defects in loaded structures is in many cases characterised by the stress intensity factor, K, which describes the spatial distribution around the crack tip. Analytical evaluation of K for generalised loading and geometry would be extremely complex. A finite element approach is described which utilises the existing UNCLE system of the UKAEA. The interpretation of the results for a fracture mechanics analysis is briefly reviewed. (author)

  8. [Depression and post-traumatic stress disorder among patients in intensive care units].

    Science.gov (United States)

    Asimakopoulou, E; Madianos, M

    2014-01-01

    Recent progress in medicine and technology has produced a significant increase in the survival rate of critically ill patients who have been treated in Intensive Care Units (ICU). Consequently, researchers have become increasingly interested in the relationship between critical illness and psychiatric consequences. The experience of critical illness has been often associated with Major Depression (MD) and Post-Traumatic Stress Disorder (PTSD). There has been no similar study in Greece. The aim of the present study was to investigate the prevalence of MD and PTSD among patients after discharge from ICU in comparison with patients who discharge from pathological or surgical department. The study was conducted on five major hospitals "ATTIKON", "THRIASSIO", "KAT", "GNA GENNIMATAS", "KORGIALENIO - BENAKIO". A standardized instrument was used especially for this study and is based on "ΜΙΝΙ: Mini International Neuropsychiatric Interview" and DSM-IV. The data collection was carried out through personal interviews with the patients. It is a cross-sectional study and also a case-control study. The sample of the research was composed of 198 patients, from whom 102 were in ICU (ICU group) and 96 were not (non-ICU group). The results of the statistical processing have shown that there is a positive and statistically significant correlation between MD-PTSD and hospitalization in ICU, and particular hospitalization in ICU increases the likelihood of developing MD by 1.94 times and PTSD by 3.48 times, compared to treatment in another part of the hospital. Furthermore, the ICU group was found to suffer more than the control group from MD (32.4% vs 19.8%) and PTSD (35,3% vs 13,5%). The investigation of sociodemographic characteristics showed that being a woman discharged from ICU is nearly five times more likely to develop MD and nearly twelve times more likely to develop PTSD compared with men. Old age in ICU acts as a protective factor from PTSD. Regarding the clinical

  9. Fatigue Crack Growth Rate and Stress-Intensity Factor Corrections for Out-of-Plane Crack Growth

    Science.gov (United States)

    Forth, Scott C.; Herman, Dave J.; James, Mark A.

    2003-01-01

    Fatigue crack growth rate testing is performed by automated data collection systems that assume straight crack growth in the plane of symmetry and use standard polynomial solutions to compute crack length and stress-intensity factors from compliance or potential drop measurements. Visual measurements used to correct the collected data typically include only the horizontal crack length, which for cracks that propagate out-of-plane, under-estimates the crack growth rates and over-estimates the stress-intensity factors. The authors have devised an approach for correcting both the crack growth rates and stress-intensity factors based on two-dimensional mixed mode-I/II finite element analysis (FEA). The approach is used to correct out-of-plane data for 7050-T7451 and 2025-T6 aluminum alloys. Results indicate the correction process works well for high DeltaK levels but fails to capture the mixed-mode effects at DeltaK levels approaching threshold (da/dN approximately 10(exp -10) meter/cycle).

  10. Pain-related stress in the Neonatal Intensive Care Unit and salivary cortisol reactivity to socio-emotional stress in 3-month-old very preterm infants.

    Science.gov (United States)

    Provenzi, Livio; Giusti, Lorenzo; Fumagalli, Monica; Tasca, Hilarj; Ciceri, Francesca; Menozzi, Giorgia; Mosca, Fabio; Morandi, Francesco; Borgatti, Renato; Montirosso, Rosario

    2016-10-01

    Very preterm (VPT) infants are hospitalized in the Neonatal Intensive Care Unit (NICU) and exposed to varying levels of skin-breaking procedures (pain-related stress), even in absence of severe clinical conditions. Repeated and prolonged pain exposure may alter hypothalamic-pituitary-adrenal (HPA) axis reactivity in VPT infants. During the post-discharge period, altered HPA axis reactivity has been documented in response to non-social stressors, using salivary cortisol as a biomarker. However, little is known about the effects of NICU pain-related stress on subsequent HPA axis reactivity to socio-emotional stress in infants. We examined the relationship between pain-related stress in NICU and HPA axis reactivity (i.e., salivary cortisol reactivity) to an age-appropriate socio-emotional condition in 37 healthy VPT infants compared to 53 full-term (FT) controls. The number of skin-breaking procedures was obtained across NICU stay for VPT infants. At 3 months (corrected age for prematurity), all infants participated in the maternal Face-to-Face Still-Face (FFSF) procedure, in order to assess HPA axis reactivity to socio-emotional stress (i.e., maternal unresponsiveness). VPT infants exhibited a blunted salivary cortisol reactivity, which was associated with the amount of skin-breaking procedures during NICU: greater pain-related stress predicted lower salivary cortisol reactivity, adjusting for neonatal confounders. These findings further advance our knowledge of how early exposure to pain-related stress in NICU contributes to the programming of an altered HPA axis reactivity to socio-emotional stress in 3-month-old VPT infants, even in the absence of major perinatal complications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Delayed memory effects after intense stress in Special Forces candidates: exploring path processes between cortisol secretion and memory recall.

    Science.gov (United States)

    Taverniers, John; Taylor, Marcus K; Smeets, Tom

    2013-05-01

    The aim of this paper is twofold. First, it explores delayed effects of high endogenously evoked cortisol concentrations on visuo-spatial declarative memory. Subsequently, it applies multiple mediation (MM) analyses to reveal path processes between stress and cognitive performance in a sample of 24 male Special Forces (SF) candidates (mean age = 27.0 years, SD = 4.1). The SF candidates were randomly assigned to a control (n = 12) or an intense stress group (n = 12), and cortisol secretion for the intense stress condition was triggered by a brusque 60 min prisoner of war exercise. Stress exposure provoked robust increases in cortisol concentrations and a significant decline in immediate recall performance, measured with the Rey-Osterrieth Complex Figure (ROCF). The relative retrieval differences in regard to the ROCF persisted even after a recovery period of 24 h, as both groups showed similar levels of memory decline over 24 h. Next, the study applied a MM design that involved distribution-independent asymptotic and resampling strategies to extend traditional bivariate analyses. MM results showed that ROCF performance was mediated by increases in cortisol concentrations. Considering the studied variables, the current analysis was the first to provide statistical support for the generally accepted thesis that cortisol secretion in itself, rather than subjective strain or the experimental treatment, affects cognitive performance. The revelation of such path processes is important because it establishes process identification and may refine existing paradigms.

  12. Analysis of stress intensity factor for a Griffith crack opened under constant pressure in a plate with temperature dependent properties

    International Nuclear Information System (INIS)

    Hata, Toshiaki

    1982-01-01

    Recently, the research on the thermal stress of structural materials has become important with the progress of nuclear reactor technology. In the case of large temperature gradient, the change of the physical properties of materials must be taken into account. The thermal stress analysis for the things with cracks taking the temperature dependence of properties into account has scarcely been carried out. In this report, the general method of solution of three-dimensional problems using perturbation method and the extension of thermo-elastic displacement potential method is shown for the case in which Young's modulus changes according to the exponential function of temperature. Moreover, using this method, the effect of the temperature dependence of properties on the stress intensity factor of the cracks subjected to internal pressure in a strip exposed to linear thermal flow was clarified. In the analysis, Young's modulus, the coefficient of linear thermal expansion and thermal conductivity were assumed to be dependent on temperature. The method of solution, the analysis of stress intensity factor considering the change of properties due to temperature, and the numerical calculation for a square plate with a crack are explained. (Kako, I.)

  13. Obesity promotes oxidative stress and exacerbates blood-brain barrier disruption after high-intensity exercise

    Directory of Open Access Journals (Sweden)

    Hee-Tae Roh

    2017-06-01

    Conclusion: Our study suggests that episodic vigorous exercise can increase oxidative stress and blood neurotrophic factor levels and induce disruption of the BBB. Moreover, high levels of neurotrophic factor in the blood after exercise in the obese group may be due to BBB disruption, and it is assumed that oxidative stress was the main cause of this BBB disruption.

  14. Predictive value of T2 relative signal intensity for response to somatostatin analogs in newly diagnosed acromegaly

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Ming; Zhang, Qilin [Fudan University, Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Shanghai (China); Shanghai Pituitary Tumor Center, Shanghai (China); Liu, Wenjuan; Li, Yiming; Zhang, Zhaoyun; Ye, Hongying; He, Min; Lu, Bin; Yang, Yeping [Shanghai Pituitary Tumor Center, Shanghai (China); Fudan University, Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Shanghai (China); Wang, Meng [Fudan University, Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Shanghai (China); Soochow University, Division of Endocrinology, the Second Affiliated Hospital, Suzhou (China); Zhu, Jingjing [Shanghai Pituitary Tumor Center, Shanghai (China); Fudan University, Department of Neuropathology, Huashan Hospital, Shanghai Medical College, Shanghai (China); Ma, Zengyi; He, Wenqiang; Li, Shiqi; Shou, Xuefei; Qiao, Nidan; Ye, Zhao; Zhang, Yichao; Zhao, Yao; Wang, Yongfei [Fudan University, Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Shanghai (China); Shanghai Pituitary Tumor Center, Shanghai (China); Yao, Zhenwei [Shanghai Pituitary Tumor Center, Shanghai (China); Fudan University, Department of Radiology, Huashan Hospital, Shanghai Medical College, Shanghai (China); Lu, Yun [Fudan University, Department of Nuclear Medicine, Huashan Hospital, Shanghai Medical College, Shanghai (China)

    2016-11-15

    The difficulty of predicting the efficacy of somatostatin analogs (SSA) is not fully resolved. Here, we quantitatively evaluated the predictive value of relative signal intensity (rSI) on T1- and T2-weighted magnetic resonance imaging (MRI) for the short-term efficacy (3 months) of SSA therapy in patients with active acromegaly and assessed the correlation between MRI rSI and expression of somatostatin receptors (SSTR). This was a retrospective review of prospectively recorded data. Ninety-two newly diagnosed patients (37 males and 55 females) with active acromegaly were recruited. All patients were treated with pre-surgical SSA, followed by reassessment and transspenoidal surgery. rSI values were generated by calculating the ratio of SI in the tumor to the SI of normal frontal white matter. The Youden indices were calculated to determine the optimal cutoff of rSI to determine the efficacy of SSA. The correlation between rSI and expression of SSTR2/5 was analyzed by the Spearman rank correlation coefficient. T2 rSI was strongly correlated with biochemical sensitivity to SSA. The cutoff value of T2 rSI to distinguish biochemical sensitivity was 1.205, with a positive predictive value (PPV) of 81.5 % and a negative predictive value (NPV) of 77.3 %. No correlation was found between MRI and tumor size sensitivity. Moreover, T2 rSI was negatively correlated with the expression of SSTR5. T2 rSI correlates with the expression of SSTR5 and quantitatively predicts the biochemical efficacy of SSA in acromegaly. (orig.)

  15. Predictive value of T2 relative signal intensity for response to somatostatin analogs in newly diagnosed acromegaly

    International Nuclear Information System (INIS)

    Shen, Ming; Zhang, Qilin; Liu, Wenjuan; Li, Yiming; Zhang, Zhaoyun; Ye, Hongying; He, Min; Lu, Bin; Yang, Yeping; Wang, Meng; Zhu, Jingjing; Ma, Zengyi; He, Wenqiang; Li, Shiqi; Shou, Xuefei; Qiao, Nidan; Ye, Zhao; Zhang, Yichao; Zhao, Yao; Wang, Yongfei; Yao, Zhenwei; Lu, Yun

    2016-01-01

    The difficulty of predicting the efficacy of somatostatin analogs (SSA) is not fully resolved. Here, we quantitatively evaluated the predictive value of relative signal intensity (rSI) on T1- and T2-weighted magnetic resonance imaging (MRI) for the short-term efficacy (3 months) of SSA therapy in patients with active acromegaly and assessed the correlation between MRI rSI and expression of somatostatin receptors (SSTR). This was a retrospective review of prospectively recorded data. Ninety-two newly diagnosed patients (37 males and 55 females) with active acromegaly were recruited. All patients were treated with pre-surgical SSA, followed by reassessment and transspenoidal surgery. rSI values were generated by calculating the ratio of SI in the tumor to the SI of normal frontal white matter. The Youden indices were calculated to determine the optimal cutoff of rSI to determine the efficacy of SSA. The correlation between rSI and expression of SSTR2/5 was analyzed by the Spearman rank correlation coefficient. T2 rSI was strongly correlated with biochemical sensitivity to SSA. The cutoff value of T2 rSI to distinguish biochemical sensitivity was 1.205, with a positive predictive value (PPV) of 81.5 % and a negative predictive value (NPV) of 77.3 %. No correlation was found between MRI and tumor size sensitivity. Moreover, T2 rSI was negatively correlated with the expression of SSTR5. T2 rSI correlates with the expression of SSTR5 and quantitatively predicts the biochemical efficacy of SSA in acromegaly. (orig.)

  16. Predictive value of T2 relative signal intensity for response to somatostatin analogs in newly diagnosed acromegaly.

    Science.gov (United States)

    Shen, Ming; Zhang, Qilin; Liu, Wenjuan; Wang, Meng; Zhu, Jingjing; Ma, Zengyi; He, Wenqiang; Li, Shiqi; Shou, Xuefei; Li, Yiming; Zhang, Zhaoyun; Ye, Hongying; He, Min; Lu, Bin; Yao, Zhenwei; Lu, Yun; Qiao, Nidan; Ye, Zhao; Zhang, Yichao; Yang, Yeping; Zhao, Yao; Wang, Yongfei

    2016-11-01

    The difficulty of predicting the efficacy of somatostatin analogs (SSA) is not fully resolved. Here, we quantitatively evaluated the predictive value of relative signal intensity (rSI) on T1- and T2-weighted magnetic resonance imaging (MRI) for the short-term efficacy (3 months) of SSA therapy in patients with active acromegaly and assessed the correlation between MRI rSI and expression of somatostatin receptors (SSTR). This was a retrospective review of prospectively recorded data. Ninety-two newly diagnosed patients (37 males and 55 females) with active acromegaly were recruited. All patients were treated with pre-surgical SSA, followed by reassessment and transspenoidal surgery. rSI values were generated by calculating the ratio of SI in the tumor to the SI of normal frontal white matter. The Youden indices were calculated to determine the optimal cutoff of rSI to determine the efficacy of SSA. The correlation between rSI and expression of SSTR2/5 was analyzed by the Spearman rank correlation coefficient. T2 rSI was strongly correlated with biochemical sensitivity to SSA. The cutoff value of T2 rSI to distinguish biochemical sensitivity was 1.205, with a positive predictive value (PPV) of 81.5 % and a negative predictive value (NPV) of 77.3 %. No correlation was found between MRI and tumor size sensitivity. Moreover, T2 rSI was negatively correlated with the expression of SSTR5. T2 rSI correlates with the expression of SSTR5 and quantitatively predicts the biochemical efficacy of SSA in acromegaly.

  17. Work stress, Chinese work values, and work well-being in the Greater China.

    Science.gov (United States)

    Lu, Luo; Kao, Shu-Fang; Siu, Oi-Ling; Lu, Chang-Qin

    2011-01-01

    Work values influence our attitudes and behavior at work, but they have rarely been explored in the context of work stress. The aim of this research was thus to test direct and moderating effects of Chinese work values (CWV) on relationships between work stressors and work well-being among employees in the Greater China region. A self-administered survey was conducted to collect data from three major cities in the region, namely Beijing, Hong Kong, and Taipei (N = 380). Work stressors were negatively related to work well-being, whereas CWV were positively related to work well-being. In addition, CWV also demonstrated moderating effects in some of the stressor-job satisfaction relationships.

  18. Growth, photosynthesis and stress indicators in young rosewood plants (Aniba rosaeodora Ducke) under different light intensities

    OpenAIRE

    Gonçalves, José Francisco de Carvalho; Barreto, Denize Caranhas de Sousa; Santos Junior, Ulysses Moreira dos; Fernandes, Andreia Varmes; Sampaio, Paulo de Tarso Barbosa; Buckeridge, Marcos Silveira

    2005-01-01

    Aniba rosaeodora is an Amazonian tree species that belongs to the family Lauraceae. Due to intense exploitation for extraction of essential oils (mainly linalol), A. rosaeodora is now considered an endangered species. On the other hand, there is little information about its ecophysiology which would be useful to support future forest planting programs. Hence, the effect of different light intensities on the growth and photosynthetic characteristics of young plants of A. rosaeodora was studied...

  19. Crack edge collocation for the direct computation of stress intensity factors using the displacement discontinuity method

    CSIR Research Space (South Africa)

    Napier, JAL

    2002-09-01

    Full Text Available The numerical solution of problems relating to crack fracture and failure can be accomplished using the displacement discontinuity boundary element method. This paper presents an extension to the normal formulation of this method to enable stress...

  20. A database to evaluate stress intensity factors of elbows with throughwall flaws under combined internal pressure and bending moment

    International Nuclear Information System (INIS)

    Chattopadhyay, J.; Dutta, B.K.; Kushwaha, H.S.; Mahajan, S.C.; Kakodkar, A.

    1993-01-01

    The advent of Leak-Before-Break (LBB) concept has replaced the traditional design basis event of Double Ended Guillotine Break (DEGB) in the design of primary heat transport (PHT) piping. The use of LBB concept requires postulation of largest credible cracks at highly stressed locations and demonstration of its stability under the maximum credible loading conditions. Stress analysis of PHT piping in nuclear power plants shows that the highly stressed piping components are normally elbows and branch tees. This necessitates detailed fracture mechanics evaluation of piping connections by computing Stress Intensity Factor (SIF) and/or J-integral. Simple analytical solutions for evaluation of SIF and J-integral for cracks in straight pipes are readily available in literature. However, the same type of solutions for elbows and tees are limited in open literature. In the present work, a database is generated to evaluate SIF for throughwall circumferential and longitudinal cracks under combined internal pressure and bending moment. Different parameters to characterise a cracked elbow are pipe factor (h), pipe bore radius to thickness ratio (r/t) and crack length. Another parameter (σ) is used to consider the relative magnitude of stresses due to internal pressure and remote bending moment. The database has been used to derive closed form expressions to evaluate SIF for elbow with cracks in terms of the aforementioned parameters. (author). 8 refs., 12 figs., 3 tabs

  1. Salivary Nerve Growth Factor Response to Intense Stress: Effect of Sex and Body Mass Index

    Science.gov (United States)

    2014-01-01

    collection and to avoid the following: brushing teeth prior to collection, using salivary stimulants (e.g., gum, lemon drops), and consuming acidic or high...individual differences in stress resilience with important prevention and therapeutic implications. A better understanding of how the stress response...existing studies of sNGF, involve mild to moderate challenges encountered in daily life. While these provide an important basis for specula- tion

  2. Effects of high-intensity interval versus continuous moderate-intensity aerobic exercise on apoptosis, oxidative stress and metabolism of the infarcted myocardium in a rat model.

    Science.gov (United States)

    Lu, Kai; Wang, Li; Wang, Changying; Yang, Yuan; Hu, Dayi; Ding, Rongjing

    2015-08-01

    The optimal aerobic exercise training (AET) protocol for patients following myocardial infarction (MI) has remained under debate. The present study therefore aimed to compare the effects of continuous moderate-intensity training (CMT) and high-intensity interval training (HIT) on cardiac functional recovery, and to investigate the potential associated mechanisms in a post-MI rat model. Female Sprague Dawley rats (8-10 weeks old) undergoing MI or sham surgery were subsequently submitted to CMT or HIT, or kept sedentary for eight weeks. Prior to and following AET, echocardiographic parameters and exercise capacity of the rats were measured. Western blotting was used to evaluate the levels of apoptosis and associated signaling pathway protein expression. The concentrations of biomarkers of oxidative stress were also determined by ELISA assay. Messenger (m)RNA levels and activity of the key enzymes for glycolysis and fatty acid oxidation, as well as the rate of adenosine triphosphate (ATP) synthesis, were also measured. Compared with the MI group, exercise capacity and cardiac function were significantly improved following AET, particularly following HIT. Left ventricular ejection fraction and fraction shortening were further improved in the MI-HIT group in comparison to that of the MI-CMT group. The two forms of AET almost equally attenuated apoptosis of the post-infarction myocardium. CMT and HIT also alleviated oxidative stress by decreasing the concentration of malondialdehyde and increasing the concentration of superoxide dismutase and glutathione peroxidase (GPx). In particular, HIT induced a greater increase in the concentration of GPx than that of CMT. AET, and HIT in particular, significantly increased the levels of mRNA and the maximal activity of phosphofructokinase-1 and carnitine palmitoyl transferase-1, as well as the maximal ratio of ATP synthesis. In addition, compared with the MI group, the expression of signaling proteins PI3K, Akt, p38mapk and AMPK

  3. Investigation of the added value of high-energy electrons in intensity-modulated radiotherapy: four clinical cases

    International Nuclear Information System (INIS)

    Korevaar, Erik W.; Huizenga, Henk; Loef, Johan; Stroom, Joep C.; Leer, Jan Willem H.; Brahme, Anders

    2002-01-01

    Purpose: Intensity-modulated radiotherapy (IMRT) with photon beams is currently pursued in many clinics. Theoretically, inclusion of intensity- and energy-modulated high-energy electron beams (15-50 MeV) offers additional possibilities to improve radiotherapy treatments of deep-seated tumors. In this study the added value of high-energy electron beams in IMRT treatments was investigated. Methods and Materials: In a comparative treatment planning study, conventional treatment plans and various types of IMRT plans were constructed for four clinical cases (cancer of the bladder, pancreas, chordoma of the sacrum, and breast). The conventional plans were used for the actual treatment of the patients. The IMRT plans were optimized using the Orbit optimization code (Loef et al., 2000) with a radiobiologic objective function. The IMRT plans were either photon or combined electron and photon beam plans, with or without dose homogeneity constraints assuming standard or increased radiosensitivities of organs at risk. Results: Large improvements in expected treatment outcome are found using IMRT plans compared to conventional plans, but differences in tumor control probability (TCP) and normal tissue complication probabilities (NTCP) values between IMRT plans with and without electrons are small. However, the use of electrons improves the dose-volume histograms for organs at risk, especially at lower dose levels (e.g., 0-40 Gy). Conclusions: This preliminary study indicates that addition of higher energy electrons to IMRT can only marginally improve treatment outcome for the selected cases. The dose-volume histograms of organs at risk show improvements for IMRT with higher energy electrons, which may reduce tumor induction but does not substantially reduce NTCP

  4. Prognostic value of stress 99Tcm-MIBI myocardial perfusion SPECT after acute myocardial infarction

    International Nuclear Information System (INIS)

    Sui Xutao; Chen Zhi; Gao Shenghai; Shen Li; Li Shang'ai

    2003-01-01

    Objective: To investigate relativity of acute myocardial infarction (AMI) with clinical, stress test and perfusion imaging parameters and to assess predictive value on hard events of cardiac death or recurrent nonfatal AMI. Methods: One hundred and one patients of AMI underwent stress 99 Tc m -MIBI SPECT before discharge. Hard and soft events were followed-up, relative factors with cardiac events were analyzed by statistical methods and predictive value on hard events were assessed. Results: Independent predictors by multivariate analysis for cardiac hard events or all cardiac events consisted of a history of prior AMI (RR=5.30, CI 2.17-12.98), a low exercise capacity (RR=6.28, CI 1.92-21.46) and left ventricular ejection fraction 99 Tc m -MIBI SPECT is a single test that can provide exercise parameter, cardiac perfusion imaging information and left ventricular function assessment to identify high-risk and estimate hard prognosis at discharge of AMI patients. These high-risk patients can be referred for early invasive evaluation and intervention

  5. Manipulating environmental stresses and stress tolerance of microalgae for enhanced production of lipids and value-added products-A review.

    Science.gov (United States)

    Chen, Bailing; Wan, Chun; Mehmood, Muhammad Aamer; Chang, Jo-Shu; Bai, Fengwu; Zhao, Xinqing

    2017-11-01

    Microalgae have promising potential to produce lipids and a variety of high-value chemicals. Suitable stress conditions such as nitrogen starvation and high salinity could stimulate synthesis and accumulation of lipids and high-value products by microalgae, therefore, various stress-modification strategies were developed to manipulate and optimize cultivation processes to enhance bioproduction efficiency. On the other hand, advancements in omics-based technologies have boosted the research to globally understand microalgal gene regulation under stress conditions, which enable further improvement of production efficiency via genetic engineering. Moreover, integration of multi-omics data, synthetic biology design, and genetic engineering manipulations exhibits a tremendous potential in the betterment of microalgal biorefinery. This review discusses the process manipulation strategies and omics studies on understanding the regulation of metabolite biosynthesis under various stressful conditions, and proposes genetic engineering of microalgae to improve bioproduction via manipulating stress tolerance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Predictive value of SAPS II and APACHE II scoring systems for patient outcome in a medical intensive care unit

    Directory of Open Access Journals (Sweden)

    Amina Godinjak

    2016-11-01

    Full Text Available Objective. The aim is to determine SAPS II and APACHE II scores in medical intensive care unit (MICU patients, to compare them for prediction of patient outcome, and to compare with actual hospital mortality rates for different subgroups of patients. Methods. One hundred and seventy-four patients were included in this analysis over a oneyear period in the MICU, Clinical Center, University of Sarajevo. The following patient data were obtained: demographics, admission diagnosis, SAPS II, APACHE II scores and final outcome. Results. Out of 174 patients, 70 patients (40.2% died. Mean SAPS II and APACHE II scores in all patients were 48.4±17.0 and 21.6±10.3 respectively, and they were significantly different between survivors and non-survivors. SAPS II >50.5 and APACHE II >27.5 can predict the risk of mortality in these patients. There was no statistically significant difference in the clinical values of SAPS II vs APACHE II (p=0.501. A statistically significant positive correlation was established between the values of SAPS II and APACHE II (r=0.708; p=0.001. Patients with an admission diagnosis of sepsis/septic shock had the highest values of both SAPS II and APACHE II scores, and also the highest hospital mortality rate of 55.1%. Conclusion. Both APACHE II and SAPS II had an excellent ability to discriminate between survivors and non-survivors. There was no significant difference in the clinical values of SAPS II and APACHE II. A positive correlation was established between them. Sepsis/septic shock patients had the highest predicted and observed hospital mortality rate.

  7. Plasma Hsp72 (HSPA1A) and Hsp27 (HSPB1) expression under heat stress: influence of exercise intensity.

    Science.gov (United States)

    Périard, Julien D; Ruell, Patricia; Caillaud, Corinne; Thompson, Martin W

    2012-05-01

    Extracellular heat-shock protein 72 (eHsp72) expression during exercise-heat stress is suggested to increase with the level of hyperthermia attained, independent of the rate of heat storage. This study examined the influence of exercise at various intensities to elucidate this relationship, and investigated the association between eHsp72 and eHsp27. Sixteen male subjects cycled to exhaustion at 60% and 75% of maximal oxygen uptake in hot conditions (40°C, 50% RH). Core temperature, heart rate, oxidative stress, and blood lactate and glucose levels were measured to determine the predictor variables associated with eHsp expression. At exhaustion, heart rate exceeded 96% of maximum in both conditions. Core temperature reached 39.7°C in the 60% trial (58.9 min) and 39.0°C in the 75% trial (27.2 min) (P exercise may relate to the duration (i.e., core temperature attained) and intensity (i.e., rate of increase in core temperature) of exercise. Thus, the immuno-inflammatory release of eHsp72 and eHsp27 in response to exercise in the heat may be duration and intensity dependent.

  8. Prognostic value of predischarge dobutamine stress echocardiography in chest pain patients with a negative cardiac troponin T

    NARCIS (Netherlands)

    Bholasingh, Radha; Cornel, Jan Hein; Kamp, Otto; van Straalen, Jan P.; Sanders, Gerard T.; Tijssen, Jan G. P.; Umans, Victor A. W. M.; Visser, Cees A.; de Winter, Robbert J.

    2003-01-01

    OBJECTIVES We prospectively studied the prognostic value of predischarge dobutamine stress echocardiography (I)SE) in low-risk chest pain patients with a normal or nondiagnostic electrocardiogram (ECG) and a negative serial troponin T. BACKGROUND Noninvasive stress testing is recommended before

  9. Stress-intensity factors for surface cracks in pipes: a computer code for evaluation by use of influence functions. Final report

    International Nuclear Information System (INIS)

    Dedhia, D.D.; Harris, D.O.

    1982-06-01

    A user-oriented computer program for the evaluation of stress intensity factors for cracks in pipes is presented. Stress intensity factors for semi-elliptical, complete circumferential and long longitudinal cracks can be obtained using this computer program. The code is based on the method of influence functions which makes it possible to treat arbitrary stresses on the plane of the crack. The stresses on the crack plane can be entered as a mathematical or tabulated function. A user's manual is included in this report. Background information is also included

  10. Prognostic Value of Exercise-Stress Echocardiography in Asymptomatic Patients With Aortic Valve Stenosis.

    Science.gov (United States)

    Goublaire, Coppelia; Melissopoulou, Maria; Lobo, David; Kubota, Naozumi; Verdonk, Constance; Cimadevilla, Claire; Codogno, Isabelle; Brochet, Eric; Vahanian, Alec; Messika-Zeitoun, David

    2017-07-19

    This study sought to evaluate the prognostic value of mean pressure gradient (MPG) increase and peak systolic pulmonary artery pressure (SPAP) measured during exercise stress echocardiography in asymptomatic patients with aortic stenosis (AS). Exercise testing is recommended in asymptomatic AS patients, but the additional value of exercise-stress echocardiography, especially the prognostic value of MPG increase and peak SPAP, is still debated. We enrolled all consecutive patients with pure, isolated, asymptomatic AS and preserved ejection fraction ≥50% and normal SPAP (20 mm Hg and/or SPAP at peak exercise >60 mm Hg). These 112 patients were managed conservatively. During a mean follow-up of 14 ± 8 months, an AS-related event occurred in 30 patients, and 25 patients underwent surgery. Neither MPG increase >20 mm Hg nor peak SPAP >60 mm Hg was predictive of occurrence of AS-related events or aortic valve replacement (all p > 0.20). In contrast, baseline AS severity was an important prognostic factor (all p < 0.01). In this observational study including 148 patients with asymptomatic AS, we confirmed and extended the importance of exercise testing for unveiling functional limitation. More importantly, neither the increase in MPG nor in SPAP at peak exercise was predictive of outcome. Our results do not support the use of these parameters in risk-stratification and clinical management of asymptomatic AS patients. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  11. Long-term persistence of quality improvements for an intensive care unit communication initiative using the VALUE strategy.

    Science.gov (United States)

    Wysham, Nicholas G; Mularski, Richard A; Schmidt, David M; Nord, Shirley C; Louis, Deborah L; Shuster, Elizabeth; Curtis, J Randall; Mosen, David M

    2014-06-01

    Communication in the intensive care unit (ICU) is an important component of quality ICU care. In this report, we evaluate the long-term effects of a quality improvement (QI) initiative, based on the VALUE communication strategy, designed to improve communication with family members of critically ill patients. We implemented a multifaceted intervention to improve communication in the ICU and measured processes of care. Quality improvement components included posted VALUE placards, templated progress note inclusive of communication documentation, and a daily rounding checklist prompt. We evaluated care for all patients cared for by the intensivists during three separate 3 week periods, pre, post, and 3 years following the initial intervention. Care delivery was assessed in 38 patients and their families in the pre-intervention sample, 27 in the post-intervention period, and 41 in follow-up. Process measures of communication showed improvement across the evaluation periods, for example, daily updates increased from pre 62% to post 76% to current 84% of opportunities. Our evaluation of this quality improvement project suggests persistence and continued improvements in the delivery of measured aspects of ICU family communication. Maintenance with point-of-care-tools may account for some of the persistence and continued improvements. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Prognostic Value of Subclassification Using MRI in the T4 Classification Nasopharyngeal Carcinoma Intensity-Modulated Radiotherapy Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Chen Lei [State Key Laboratory of Oncology in South China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou (China); Liu Lizhi [State Key Laboratory of Oncology in South China, Imaging Diagnosis and Interventional Center, Sun Yat-sen University Cancer Center, Guangzhou (China); Chen Mo; Li Wenfei; Yin Wenjing [State Key Laboratory of Oncology in South China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou (China); Lin Aihua [Department of Medical Statistics and Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou (China); Sun Ying [State Key Laboratory of Oncology in South China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou (China); Li Li [State Key Laboratory of Oncology in South China, Imaging Diagnosis and Interventional Center, Sun Yat-sen University Cancer Center, Guangzhou (China); Ma Jun, E-mail: majun2@mail.sysu.edu.cn [State Key Laboratory of Oncology in South China, Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou (China)

    2012-09-01

    Purpose: To subclassify patients with the T4 classification nasopharyngeal carcinoma (NPC), according to the seventh edition of the American Joint Committee on Cancer staging system, using magnetic resonance imaging (MRI), and to evaluate the prognostic value of subclassification after intensity-modulated radiotherapy (IMRT). Methods and Materials: A total of 140 patients who underwent MRI and were subsequently histologically diagnosed with nondisseminated classification T4 NPC received IMRT as their primary treatment and were included in this retrospective study. T4 patients were subclassified into two grades: T4a was defined as a primary nasopharyngeal tumor with involvement of the masticator space only; and T4b was defined as involvement of the intracranial region, cranial nerves, and/or orbit. Results: The 5-year overall survival (OS) rate and distant metastasis-free survival (DMFS) rate for T4a patients (82.5% and 87.0%, respectively), were significantly higher than for T4b patients (62.6% and 66.8%; p = 0.033 and p = 0.036, respectively). The T4a/b subclassification was an independent prognostic factor for OS (hazard ratio = 2.331, p = 0.032) and DMFS (hazard ratio = 2.602, p = 0.034), and had no significant effect on local relapse-free survival. Conclusions: Subclassification of T4 patients, as T4a or T4b, using MRI according to the site of invasion, has prognostic value for the outcomes of IMRT treatment in NPC.

  13. Impact of intensive insulin treatment on the development and consequences of oxidative stress in insulin-dependent diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Kocić Radivoj

    2007-01-01

    Full Text Available Background/Aim. The aim of this study, which included patients with insulin-dependent diabetes mellitus, was to determine the influence of the application of various treatment modalities (intensive or conventional on the total plasma antioxidative capacity and lipid peroxidation intensity expressed as malondialdehyde (MDA level, catalase and xanthine oxidase activity, erythrocyte glutatione reduced concentration (GSH RBC, erythrocyte MDA level (MDA RBC, as well as susceptibility of erythrocyte to H2O2-induced oxidative stress. Methods. This study included 42 patients with insulin-dependent diabetes mellitus. In 24 of the patients intensive insulin treatment was applied using the model of short-acting insulin in each meal and medium- acting insulin before going to bed, while in 18 of the patients conventional insulin treatment was applied in two (morning and evening doses. In the examined patients no presence of diabetes mellitus complications was recorded. The control group included 20 healthy adults out of a blood doner group. The plasma and erythrocytes taken from the blood samples were analyzed immediately. Results. This investigation proved that the application of intensive insulin treatment regime significantly improves total antioxidative plasma capacity as compared to the application of conventional therapy regime. The obtained results showed that the both plasma and lipoproteines apo B MDA increased significantly more in the patients on conventional therapy than in the patients on intensive insulin therapy, most probably due to intensified xanthine oxidase activity. The level of the MDA in fresh erythrocytes did not differ significantly between the groups on intensive and conventional therapy. The level of GSH and catalase activity, however, were significantly reduced in the patients on conventional therapy due to the increased susceptibility to H2O2-induced oxidative stress . Conclusion. The presented study confirmed positive effect of

  14. Influence of overelastic loading on the stress intensity factor under thermal fatigue conditions

    International Nuclear Information System (INIS)

    Stamm, H.; Munz, D.

    1983-10-01

    Thermal shock loading often creates high thermal stresses which may exceed yield strength of the material in a surface layer. In this report the application of the linear elastic ΔK-concept in the case of cyclic thermal loading within the shakedown region is discussed. To this K-factors for an edge crack in a linear elastic - perfectly plastic plate are calculated using the weight function method and are compared with results obtained with the Finite Element Method. It is shown, that rearrangement stresses during plastic flow in the first cycle must be taken into account developing conservative approximation procedures. (orig.) [de

  15. Effects of water stress and light intensity on chlorophyll fluorescence parameters and pigments of Aloe vera L.

    Science.gov (United States)

    Hazrati, Saeid; Tahmasebi-Sarvestani, Zeinolabedin; Modarres-Sanavy, Seyed Ali Mohammad; Mokhtassi-Bidgoli, Ali; Nicola, Silvana

    2016-09-01

    Aloe vera L. is one of the most important medicinal plants in the world. In order to determine the effects of light intensity and water deficit stress on chlorophyll (Chl) fluorescence and pigments of A. vera, a split-plot in time experiment was laid out in a randomized complete block design with four replications in a research greenhouse. The factorial combination of three light intensities (50, 75 and 100% of sunlight) and four irrigation regimes (irrigation after depleting 20, 40, 60 and 80% of soil water content) were considered as main factors. Sampling time was considered as sub factor. The first, second and third samplings were performed 90, 180 and 270 days after imposing the treatments, respectively. The results demonstrated that the highest light intensity and the severe water stress decreased maximum fluorescence (Fm), variable fluorescence (Fv)/Fm, quantum yield of PSII photochemistry (ФPSII), Chl and photochemical quenching (qP) but increased non-photochemical quenching (NPQ), minimum fluorescence (F0) and Anthocyanin (Anth). Additionally, the highest Fm, Fv/Fm, ФPSII and qP and the lowest NPQ and F0 were observed when 50% of sunlight was blocked and irrigation was done after 40% soil water depletion. Irradiance of full sunlight and water deficit stress let to the photoinhibition of photosynthesis, as indicated by a reduced quantum yield of PSII, ФPSII, and qP, as well as higher NPQ. Thus, chlorophyll florescence measurements provide valuable physiological data. Close to half of total solar radiation and irrigation after depleting 40% of soil water content were selected as the most efficient treatments. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  16. Is Less Noise, Light and Parental/Caregiver Stress in the Neonatal Intensive Care Unit Better for Neonates?

    Science.gov (United States)

    Venkataraman, Rohini; Kamaluddeen, Majeeda; Amin, Harish; Lodha, Abhay

    2018-01-15

    In utero sensory stimuli and interaction with the environment strongly influence early phases of fetal and infant development. Extremely premature infants are subjected to noxious procedures and routine monitoring, in addition to exposure to excessive light and noise, which disturb the natural sleep cycle and induce stress. Non-invasive ventilation, measures to prevent sepsis, and human milk feeding improve short-term and long-term neurodevelopmental outcomes in premature infants. To preserve brain function, and to improve quality of life and long-term neurodevelopmental outcomes, the focus now is on the neonatal intensive care unit (NICU) environment and its impact on the infant during hospital stay. The objectives of this write-up are to understand the effects of environmental factors, including lighting and noise in the NICU, on sensory development of the infant, the need to decrease parental and caregiver stress, and to review existing literature, local policies and recommendations.

  17. Intensity of heat stress in winter wheat—phenology compensates for the adverse effect of global warming

    International Nuclear Information System (INIS)

    Rezaei, Ehsan Eyshi; Siebert, Stefan; Ewert, Frank

    2015-01-01

    Higher temperatures during the growing season are likely to reduce crop yields with implications for crop production and food security. The negative impact of heat stress has also been predicted to increase even further for cereals such as wheat under climate change. Previous empirical modeling studies have focused on the magnitude and frequency of extreme events during the growth period but did not consider the effect of higher temperature on crop phenology. Based on an extensive set of climate and phenology observations for Germany and period 1951–2009, interpolated to 1 × 1 km resolution and provided as supplementary data to this article (available at stacks.iop.org/ERL/10/024012/mmedia), we demonstrate a strong relationship between the mean temperature in spring and the day of heading (DOH) of winter wheat. We show that the cooling effect due to the 14 days earlier DOH almost fully compensates for the adverse effect of global warming on frequency and magnitude of crop heat stress. Earlier heading caused by the warmer spring period can prevent exposure to extreme heat events around anthesis, which is the most sensitive growth stage to heat stress. Consequently, the intensity of heat stress around anthesis in winter crops cultivated in Germany may not increase under climate change even if the number and duration of extreme heat waves increase. However, this does not mean that global warning would not harm crop production because of other impacts, e.g. shortening of the grain filling period. Based on the trends for the last 34 years in Germany, heat stress (stress thermal time) around anthesis would be 59% higher in year 2009 if the effect of high temperatures on accelerating wheat phenology were ignored. We conclude that climate impact assessments need to consider both the effect of high temperature on grain set at anthesis but also on crop phenology. (letter)

  18. Intensity of heat stress in winter wheat—phenology compensates for the adverse effect of global warming

    Science.gov (United States)

    Eyshi Rezaei, Ehsan; Siebert, Stefan; Ewert, Frank

    2015-02-01

    Higher temperatures during the growing season are likely to reduce crop yields with implications for crop production and food security. The negative impact of heat stress has also been predicted to increase even further for cereals such as wheat under climate change. Previous empirical modeling studies have focused on the magnitude and frequency of extreme events during the growth period but did not consider the effect of higher temperature on crop phenology. Based on an extensive set of climate and phenology observations for Germany and period 1951-2009, interpolated to 1 × 1 km resolution and provided as supplementary data to this article (available at stacks.iop.org/ERL/10/024012/mmedia), we demonstrate a strong relationship between the mean temperature in spring and the day of heading (DOH) of winter wheat. We show that the cooling effect due to the 14 days earlier DOH almost fully compensates for the adverse effect of global warming on frequency and magnitude of crop heat stress. Earlier heading caused by the warmer spring period can prevent exposure to extreme heat events around anthesis, which is the most sensitive growth stage to heat stress. Consequently, the intensity of heat stress around anthesis in winter crops cultivated in Germany may not increase under climate change even if the number and duration of extreme heat waves increase. However, this does not mean that global warning would not harm crop production because of other impacts, e.g. shortening of the grain filling period. Based on the trends for the last 34 years in Germany, heat stress (stress thermal time) around anthesis would be 59% higher in year 2009 if the effect of high temperatures on accelerating wheat phenology were ignored. We conclude that climate impact assessments need to consider both the effect of high temperature on grain set at anthesis but also on crop phenology.

  19. Organizational Stressors and Related Stress Intensities in Tehran\\'s Comprehensive Rehabilitation Centers: From the Employees\\' Point of View

    Directory of Open Access Journals (Sweden)

    Nayyereh Tavafi

    2007-01-01

    Full Text Available Objective: Rehabilitation services employees are exposed to stressors at everyday work because they are in touch with people who disability and problems have associated with. Inappropriate policies and processes in work place aggravate stress and would adversely affect mental and physical health of this population which in turn would affect their quality of work. Materials & Methods: In order to determine the status of inappropriate organizational policies and processes as organizational stressors and related stress intensities in Tehran’s comprehensive rehabilitation centers, in a descriptive study all of the personnel were asked to fill a questionnaire which consisted of 32 questions. Content validity was approved by expertise people and reliability was 0.83. Results: Revealed that misevaluation of employees (%98 and using unclear and inappropriate criteria for evaluating personal (%95 were the most prevalent inappropriate organizational policy and process that personnel confronted with. Also we found that exposure to "inequality of payment for similar jobs" and "invalidity of criteria which were used for personnel evaluation", induced highest degree of stress on employees (2.64 from 4 & 1.71from 4 respectively. Conclusion: We conclude that as the most prevalent factor which induced stress in personnel is misevaluation, correction of personnel evaluation system should be over emphasized.

  20. Analytical Solution for Stress Field and Intensity Factor in CSTBD under Mixed Mode Conditions

    Directory of Open Access Journals (Sweden)

    Najaf Ali Ghavidel

    2014-06-01

    Full Text Available Considering the fact that rocks fail faster under tensile stress, rock tensile strength is of greatimportance in applications such as blasting, rock fragmentation, slope stability, hydraulic fracturing,caprock integrity, and geothermal energy extraction. There are two direct and indirect methods tomeasure tensile strength. Since direct methods always encompass difficulties in test setup, indirectmethods, specifically the Brazilian test, have often been employed for tensile strength measurement.Tensile failure is technically attributed to crack propagation in rock. Fracture mechanics hassignificant potential for the determination of crack behaviour as well as propagation pattern. To applyBrazilian tests, cracked disc geometry has been suggested by the International Society for RockMechanics ISRM. Accordingly, a comprehensive study is necessary to evaluate stress field and stressintensity factor (SIF around the crack in the centre of the specimen. In this paper, superpositionprinciple is employed to solve the problem of cracked straight-through Brazilian disc (CSTBD, usingtwo methods of dislocation and complex stress function. Stress field and SIF in the vicinity of thecrack tip are then calculated. With the proposed method, the magnitude of critical load for crackinitiation in structures can be predicted. This method is valid for any crack of any arbitrary length andangle. In addition, numerical modelling has been carried out for the Brazilian disc. Finally, theanalytical solution has been compared with numerical modelling results showing the same outcomefor both methods.

  1. Infants born preterm, stress, and neurodevelopment in the neonatal intensive care unit: might music have an impact?

    Science.gov (United States)

    Anderson, Dane E; Patel, Aniruddh D

    2018-03-01

    The neonatal intensive care unit (NICU) provides life-saving medical care for an increasing number of newborn infants each year. NICU care, while lifesaving, does have attendant consequences which can include repeated activation of the stress response and reduced maternal interaction, with possible negative long-term impacts on brain development. Here we present a neuroscientific framework for considering the impact of music on neurodevelopment in the NICU of infants born preterm and evaluate current literature on the use of music with this population to determine what is most reliably known of the physiological effects of music interventions. Using online academic databases we collected relevant, experimental studies aimed at determining effects of music listening in infants in the NICU. These articles were evaluated for methodological rigor, ranking the 10 most experimentally stringent as a representative sample. The selected literature seems to indicate that effects are present on the cardio-pulmonary system and behavior of neonates, although the relative effect size remains unclear. These findings indicate a need for more standardized longitudinal studies aimed at determining not only whether NICU music exposure has beneficial effects on the cardio-pulmonary system, but also on the hypothalamic-pituitary-adrenal axis, brain structures, and cognitive behavioral status of these children as well. Provides a neuroscience framework for considering how music might attenuate stress in neonatal intensive care unit (NICU) infants. Considers how repeated stress may cause negative neurodevelopmental impacts in infants born preterm. Posits epigenetics can serve as a mechanistic pathway for music moderating the stress response. © 2018 Mac Keith Press.

  2. Analysis of stress corrosion data by means of the statistic of extreme values

    International Nuclear Information System (INIS)

    Imarisio, G.; Lanza, F.

    1978-01-01

    The possibility of examining stress corosion by means of extreme statistic was proposed. A series of test in boiling MgCl 2 of samples made on AISI 304 have been performed. Evolution of cracks dimension and time of life of samples was followed. It has been shown that the dimensions of the maximum cracks on the sample corroded for different times can be organized following the extreme values statistic. Also the life time of sample can be treated in the same way. A confirmation has been obtained using data taken from literature. Possible uses of predictions obtained with this type of analysis have been underlined. An extension of the toward less corrosive media and samples of several volumes is suggested to check the validity of the method

  3. Diagnostic value of exercise stress testing, dipyridamole stress-echocardiography and perfusion stress-scintigraphy for identification of coronary artery disease in women

    International Nuclear Information System (INIS)

    Debnath, S.; Tyrnovska-Kydreva, R.; Khalacheva, S.; Radoslavova, R.; Stoyanova, N.; Draganov, T.; Elenkova, A.; Garcheva, M.; Shejretova, E.

    1995-01-01

    To compare the value of exercise stress testing (EST), dipyridamole stress echocardiography and 99m Tc-methoxy-isobutyl-isonitrile (MIBI)-planer scintigraphy, 75 female patients with angina pectoris who underwent coronary angiography were studied. Significant (≥50% stenosis) coronary artery disease (CAD) was present in 38 of the patients. EST was performed in all of the patients but dipyridamole echocardiography and MIBI-planer scintigraphy - in 36 of them (22 with and 14 without CAD). Compared with dipyridamole echocardiography, EST and MIBI-planer scintigraphy had a significantly higher sensitivity (74% vs 45%, p<0.01 and 82% vs 45%, p<0.01, respectively). There was no significant difference in sensitivity between EST and MIBI-planer scintigraphy. Dipyridamole echocardiography and MIBI-planer scintigraphy showed a higher specificity than EST (93% vs 54%, p<0.01 and 93% vs 54%, p<0.01, respectively). Diagnostic accuracy of MIBI-planer scintigraphy was higher than that of dipyridamole echocardiography and EST (86% vs 64%, p<0.05 and 86 vs 64%, p<0.01, respectively). Thus, MIBI-planer scintigraphy appears to be superior to EST and dipyridamole echocardiography for the evaluation of CAD in symptomatic women. 20 refs., 2 tabs. (author)

  4. Involvement of Potassium Transport Systems in the Response of Synechocystis PCC 6803 Cyanobacteria to External pH Change, High-Intensity Light Stress and Heavy Metal Stress.

    Science.gov (United States)

    Checchetto, Vanessa; Segalla, Anna; Sato, Yuki; Bergantino, Elisabetta; Szabo, Ildiko; Uozumi, Nobuyuki

    2016-04-01

    The unicellular photosynthetic cyanobacterium, able to survive in varying environments, is the only prokaryote that directly converts solar energy and CO2 into organic material and is thus relevant for primary production in many ecosystems. To maintain the intracellular and intrathylakoid ion homeostasis upon different environmental challenges, the concentration of potassium as a major intracellular cation has to be optimized by various K(+)uptake-mediated transport systems. We reveal here the specific and concerted physiological function of three K(+)transporters of the plasma and thylakoid membranes, namely of SynK (K(+)channel), KtrB (Ktr/Trk/HKT) and KdpA (Kdp) in Synechocystis sp. strain PCC 6803, under specific stress conditions. The behavior of the wild type, single, double and triple mutants was compared, revealing that only Synk contributes to heavy metal-induced stress, while only Ktr/Kdp is involved in osmotic and salt stress adaptation. With regards to pH shifts in the external medium, the Kdp/Ktr uptake systems play an important role in the adaptation to acidic pH. Ktr, by affecting the CO2 concentration mechanism via its action on the bicarbonate transporter SbtA, might also be responsible for the observed effects concerning high-light stress and calcification. In the case of illumination with high-intensity light, a synergistic action of Kdr/Ktp and SynK is required in order to avoid oxidative stress and ensure cell viability. In summary, this study dissects, using growth tests, measurement of photosynthetic activity and analysis of ultrastructure, the physiological role of three K(+)transporters in adaptation of the cyanobacteria to various environmental changes. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  5. Effect of gender on the prognostic value of dobutamine stress myocardial contrast echocardiography

    Directory of Open Access Journals (Sweden)

    Constantina Aggeli

    2017-11-01

    Full Text Available Background: Dobutamine stress contrast echo (DSCE has a well-established prognostic value in the context of coronary artery disease (CAD. However, data regarding its prognostic capability separately in men and women are scarce. The aim of the current study was to assess gender-related differences in the prognostic performance of DSCE. Methods: DSCE was performed in 2645 consecutive patients, who were classified into two groups depending on gender. Follow-up lasted 57.1±10.1 months. End points included all-cause mortality, cardiac death, late revascularization, and hospitalizations. Survival analysis was performed comparing men and women. Results: Of the 2645 patients (59.3±8.7 years, 69.1% were men. DSCE was positive in 23.4% of male patients, while in females, the respective percentage was 14.3%. There was statistically significant difference between the two groups with regard to end point occurrence (11.6% vs. 6.1%, p<0.05. Multivariate analysis revealed that the DSCE response was the strongest predictor of adverse outcomes (Exp(B=51.9, p<0.05 in both groups. The predictive model including DSCE results along with clinical data performed well without significant differences between males and females (C-index 0.93 vs. 0.87 respectively, p=NS. Conclusion: DSCE has a strong prognostic value for patients with known or suspected CAD, regardless of patient gender. This makes DSCE an attractive screening option for women in whom CAD assessment can be challenging. Keywords: stress echocardiography, women, gender, prognosis, coronary artery disease

  6. Oxidative stress and antioxidant biomarker responses after a moderate-intensity soccer training session.

    Science.gov (United States)

    Mello, Rodrigo; Mello, Ricardo; Gomes, Diego; Paz, Gabriel Andrade; Nasser, Igor; Miranda, Humberto; Salerno, Verônica P

    2017-01-01

    The present study investigated the effects of a moderate-intensity soccer training session on the production of reactive oxygen species (ROS) and the antioxidant capacity in athletes along with the biomarkers creatine kinase and transaminases for lesions in muscle and liver cells. Twenty-two male soccer players participated in this study. Blood samples were collected 5 min before and after a moderate-intensity game simulation. The results showed a decrease in the concentration of reduced glutathione (GSH) from an elevation in the production of ROS that maintained the redox homeostasis. Although the session promoted an elevated energy demand, observed by an increase in lactate and glucose levels, damage to muscle and/or liver cells was only suggested by a significant elevation in the levels of alanine transaminase (ALT). Of the two biomarkers analysed, the results suggest that measurements of the ALT levels could be adopted as a method to monitor recovery in athletes.

  7. A plastic stress intensity factor approach to turbine disk structural integrity assessment

    OpenAIRE

    Shlyannikov, V.; Zakharov, A.; Yarullin, R.

    2016-01-01

    This study based on a new fracture mechanics parameter is concerned with assessing the integrity of cracked steam turbine disk which operate under startup-shutdown cyclic loading conditions. Damage accumulation and growth in service have occurred on the inner surface of slot fillet of key. In order to determine elastic-plastic fracture mechanics parameters full-size stress-strain state analysis of turbine disk was performed for a quote-elliptical part-through cracks under consider...

  8. Adaptive force produced by stress-induced regulation of random variation intensity.

    Science.gov (United States)

    Shimansky, Yury P

    2010-08-01

    The Darwinian theory of life evolution is capable of explaining the majority of related phenomena. At the same time, the mechanisms of optimizing traits beneficial to a population as a whole but not directly to an individual remain largely unclear. There are also significant problems with explaining the phenomenon of punctuated equilibrium. From another perspective, multiple mechanisms for the regulation of the rate of genetic mutations according to the environmental stress have been discovered, but their precise functional role is not well understood yet. Here a novel mathematical paradigm called a Kinetic-Force Principle (KFP), which can serve as a general basis for biologically plausible optimization methods, is introduced and its rigorous derivation is provided. Based on this principle, it is shown that, if the rate of random changes in a biological system is proportional, even only roughly, to the amount of environmental stress, a virtual force is created, acting in the direction of stress relief. It is demonstrated that KFP can provide important insights into solving the above problems. Evidence is presented in support of a hypothesis that the nature employs KFP for accelerating adaptation in biological systems. A detailed comparison between KFP and the principle of variation and natural selection is presented and their complementarity is revealed. It is concluded that KFP is not a competing alternative, but a powerful addition to the principle of variation and natural selection. It is also shown KFP can be used in multiple ways for adaptation of individual biological organisms.

  9. Global Metabolic Stress of Isoeffort Continuous and High Intensity Interval Aerobic Exercise: A Comparative 1H NMR Metabonomic Study.

    Science.gov (United States)

    Zafeiridis, Andreas; Chatziioannou, Anastasia Chrysovalantou; Sarivasiliou, Haralambos; Kyparos, Antonios; Nikolaidis, Michalis G; Vrabas, Ioannis S; Pechlivanis, Alexandros; Zoumpoulakis, Panagiotis; Baskakis, Constantinos; Dipla, Konstantina; Theodoridis, Georgios A

    2016-12-02

    The overall metabolic/energetic stress that occurs during an acute bout of exercise is proposed to be the main driving force for long-term training adaptations. Continuous and high-intensity interval exercise protocols (HIIE) are currently prescribed to acquire the muscular and metabolic benefits of aerobic training. We applied 1 H NMR-based metabonomics to compare the overall metabolic perturbation and activation of individual bioenergetic pathways of three popular aerobic exercises matched for effort/strain. Nine men performed continuous, long-interval (3 min), and short-interval (30 s) bouts of exercise under isoeffort conditions. Blood was collected before and after exercise. The multivariate PCA and OPLS-DA models showed a distinct separation of pre- and postexercise samples in three protocols. The two models did not discriminate the postexercise overall metabolic profiles of the three exercise types. Analysis focused on muscle bioenergetic pathways revealed an extensive upregulation of carbohydrate-lipid metabolism and the TCA cycle in all three protocols; there were only a few differences among protocols in the postexercise abundance of molecules when long-interval bouts were performed. In conclusion, continuous and HIIE exercise protocols, when performed with similar effort/strain, induce comparable global metabolic response/stress despite their marked differences in work-bout intensities. This study highlights the importance of NMR metabonomics in comprehensive monitoring of metabolic consequences of exercise training in the blood of athletes and exercising individuals.

  10. Stress intensity factor analysis of friction sliding at discontinuity interfaces and junctions

    CSIR Research Space (South Africa)

    Phan, AV

    2003-12-01

    Full Text Available ]) and boundary element method (BEM) [2?5]. The key feature of the integral equation approach is that only the boundary of the domain is discretized and only boundary quantities are determined. As a result, for fracture analy- sis, the singular stress field ahead... collocation ap- proach enforces the BIE (1) and HBIE (2) at discrete source points whereas these equations are satisfied in an averaged sense with the Galerkin approximation. The additional boundary integration is the key to obtaining a symmetric coefficient...

  11. High-intensity stress elicits robust cortisol increases, and impairs working memory and visuo-spatial declarative memory in Special Forces candidates: A field experiment.

    Science.gov (United States)

    Taverniers, John; Van Ruysseveldt, Joris; Smeets, Tom; von Grumbkow, Jasper

    2010-07-01

    While running a selection procedure, 27 male Belgian Special Forces candidates, with a mean age of 27.4 years (SD = 5.1), were randomly assigned to a no-stress control (n = 14) or a high-intensity stress group (n = 13). Participants in the latter group were exposed to an extremely strenuous mock prisoner of war (POW) exercise. Immediately after stress or control treatment, working memory and visuo-spatial declarative memory performances were measured by the digit span (DS) test and the Rey-Osterrieth complex figure (ROCF), respectively. Concurrently, stress levels were assessed by obtaining salivary cortisol measurements and subjectively by the NASA Task Load Index (TLX). As expected, exposure to high-intensity stress led to both robust cortisol increases and significant differences in TLX scores. Stress induction also significantly impaired DS and ROCF performances. Moreover, delta cortisol increases and ROCF performance in the POW stress group showed a significant negative correlation, while DS performances followed the same tendency. Summarizing, the current findings complement and extend previous work on hormonal stress effects, and the subsequent performance deterioration on two memory tests in a unique high-intensity stress environment.

  12. Prognostic value of stress myocardial perfusion positron emission tomography: results from a multicenter observational registry.

    Science.gov (United States)

    Dorbala, Sharmila; Di Carli, Marcelo F; Beanlands, Rob S; Merhige, Michael E; Williams, Brent A; Veledar, Emir; Chow, Benjamin J W; Min, James K; Pencina, Michael J; Berman, Daniel S; Shaw, Leslee J

    2013-01-15

    The primary objective of this multicenter registry was to study the prognostic value of positron emission tomography (PET) myocardial perfusion imaging (MPI) and the improved classification of risk in a large cohort of patients with suspected or known coronary artery disease (CAD). Limited prognostic data are available for MPI with PET. A total of 7,061 patients from 4 centers underwent a clinically indicated rest/stress rubidium-82 PET MPI, with a median follow-up of 2.2 years. The primary outcome of this study was cardiac death (n = 169), and the secondary outcome was all-cause death (n = 570). Net reclassification improvement (NRI) and integrated discrimination analyses were performed. Risk-adjusted hazard of cardiac death increased with each 10% myocardium abnormal with mildly, moderately, or severely abnormal stress PET (hazard ratio [HR]: 2.3 [95% CI: 1.4 to 3.8; p = 0.001], HR: 4.2 [95% CI: 2.3 to 7.5; p statistic 0.805 [95% CI: 0.772 to 0.838] to 0.839 [95% CI: 0.809 to 0.869]) and risk reclassification for cardiac death (NRI 0.116 [95% CI: 0.021 to 0.210]), with smaller improvements in risk assessment for all-cause death. In patients with known or suspected CAD, the extent and severity of ischemia and scar on PET MPI provided powerful and incremental risk estimates of cardiac death and all-cause death compared with traditional coronary risk factors. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  13. Diagnostic value of rest and stress gated 82Rb PET myocardial perfusion imaging using quantitative software

    International Nuclear Information System (INIS)

    Shi Hongcheng; Gu Yusen; Liu Wenguan; Zhu Weimin; Halkar, R.K.; Santana, C.A.; Feng Yusheng

    2008-01-01

    Objective: Gated myocardial perfusion imaging (MPI) is regularly performed using SPECT. More recently, gated 82 Rb MPI has been used to assess left ventricular myocardial perfusion and function with new generation PET scanners. The objective of this study was to evaluate the value of rest and stress gated 82 Rb PET myocardial perfusion imaging and to determine whether the quantitative technique in- creased the confidence level of the interpreters. Methods: Thirty-two patients underwent rest and adenosine stress gated 82 Pb PET MPI. Emory Cardiac Toolbox quantitative software was used for processing and inter-predation. Left ventricular ejection fraction (LVEF), end-diastolic, end-systolic and transient ischemia dilation ratio were automatically generated. Three interpreters (nuclear medicine doctors) independently reviewed the studies. Visual scoring (1-5 scales: excellent, good, unsure, poor, uninterpretable) was used to assess the overall quality of the gated images and the added confidence level of interpretation. Visual assessment of the LVEF was compared to the automatically generated LVEF. Comparison between the visual assessment and software generated was graded on a 1- 5 scales (helpful, probably helpful, unsure, probably not helpful, definitely not helpful). The analysed items were divided into two groups (favorable group and negative group). The percentage and 95% confidence intervals of each group were calculated. Results: A total of 192 gated studies were evaluated (64 gated x 3 interpreters ). The overall quality of the gated images was good [excellent 40.1% (77/192), good 43.2% (83/192), unsure 3.1% (6/192), poor 13.6% (26/192), uninterpretable 0]. The 95% confidence intervals of good and excellent quality range from 78.1% to 88.6%. The interpreter's agreed with the automated LVEF on 85.4% of the gated images [agree 76.6% (147/192), probably agree 8.8% (17/192), unsure 3.1% (6/192), probably disagree 8.8% (17/192), disagree 2.6% (5/192)]. And its 95

  14. Risk-associated health disorders occuring in junior schoolchildren who attend schools with higher stress and intensity of educational process

    Directory of Open Access Journals (Sweden)

    N.V. Zaitseva

    2017-03-01

    Full Text Available We performed comparative sanitary-hygienic assessment of regime, stress and intensity of educational process in different educational establishments, a comprehensive secondary school and an innovative educational establishment - lyceum. We detected that studying regime tended to be tight, classes were longer and more intense than in an ordinary school, and educational process involved considerable intellectual, sensory and emotional loads for children; such loads reached "1st category intense" level. Schoolchildren attending lyceums are also busy with additional educational programs and it significantly increases length of total educational load on them. By the end of a school year 20% of lyceum pupils suffer from sympathoadrenal system overstress and it doesn't only determine emotional tonus level in children but also leads to disorders in concentration and decision-making speed, lower reading speed and articulation, slower motor reactions. 15% of lyceum pupils have higher activity of autonomous nervous system and lower adaptation of cardiovascular system to psycho emotional and physical loads. Lyceum pupils also run 2.5 times higher risk of chronic nervous system diseases evolvement than school children attending ordinary schools. Autonomous nervous system disorders, posture disorders and nutrition disorders are predominant nosologic pathology forms in lyceum pupils as they occur in them 1.6-2.9 times more frequent than in schoolchildren of the same age who attend an ordinary comprehensive school. We detected direct correlation between higher intellectual and emotional components of educational process, and total educational intensity as well, and frequency of autonomous system disorders and musculoskeletal system diseases in pupils.

  15. Prognostic Value of Cavernous Sinus Invasion in Patients with Nasopharyngeal Carcinoma Treated with Intensity-Modulated Radiotherapy.

    Directory of Open Access Journals (Sweden)

    Jun-Fang Liao

    Full Text Available To investigate the prognostic value of cavernoussinus invasion (CSI in patients with nasopharyngeal carcinoma (NPC treated with intensity-modulated radiotherapy (IMRT.Retrospective review of data from 1,087 patients with biopsy-proven, non-metastatic NPC. All patients were diagnosed using magnetic resonance imaging (MRI scans and received IMRT as the primary treatment.The incidence of cavernoussinus invasion in this cohort was 12.1%. In univariate analysis, 5-year overall survival (OS (70.6% vs. 88.5%, P < 0.001 and distant metastasis-free survival (DMFS (71.4% vs. 87.7%, P < 0.001, but not locoregional relapse-free survival (LRFS (93.9% vs. 93.7%, P = 0.341, were significantly different between patients with and without cavernoussinus invasion. In the T4 subgroup, the 5-year OS, DMFS, and LRFS of patients with and without cavernoussinus extension were 70.6% vs. 81.9% (P = 0.011, 71.4% vs. 84.1% (P = 0.011, and 91.2% vs. 89.7% (P = 0.501, respectively. In multivariate analysis, cavernoussinus invasion was an independent prognostic factor for poorer OS (HR = 1.782; P = 0.013 and DMFS (HR = 1.771; P = 0.016, but not LRFS (HR = 0.632; P = 0.294. In patients with lymph node metastasis, the DMFS rates of patients with and without cavernoussinus invasion were significantly different (P < 0.001. Preliminaryanalysis indicated that neoadjuvant chemotherapy led to better DMFS and OS in patients with cavernoussinus invasion than concurrent chemotherapy or radiotherapy alone; however, the differences were not significant.In the IMRT era, cavernoussinus invasion remains a prognostic factor for poor DMFS and OS in NPC, even in patients with T4 disease.

  16. The clinical value of daily routine chest radiographs in a mixed medical-surgical intensive care unit is low.

    Science.gov (United States)

    Graat, Marleen E; Choi, Goda; Wolthuis, Esther K; Korevaar, Johanna C; Spronk, Peter E; Stoker, Jaap; Vroom, Margreeth B; Schultz, Marcus J

    2006-02-01

    The clinical value of daily routine chest radiographs (CXRs) in critically ill patients is unknown. We conducted this study to evaluate how frequently unexpected predefined major abnormalities are identified with daily routine CXRs, and how often these findings lead to a change in care for intensive care unit (ICU) patients. This was a prospective observational study conducted in a 28-bed, mixed medical-surgical ICU of a university hospital. Over a 5-month period, 2,457 daily routine CXRs were done in 754 consecutive ICU patients. The majority of these CXRs did not reveal any new predefined major finding. In only 5.8% of daily routine CXRs (14.3% of patients) was one or more new and unexpected abnormality encountered, including large atelectases (24 times in 20 patients), large infiltrates (23 in 22), severe pulmonary congestion (29 in 25), severe pleural effusion (13 in 13), pneumothorax/pneumomediastinum (14 in 13), and malposition of the orotracheal tube (32 in 26). Fewer than half of the CXRs with a new and unexpected finding were ultimately clinically relevant; in only 2.2% of all daily routine CXRs (6.4% of patients) did these radiologic abnormalities result in a change to therapy. Subgroup analysis revealed no differences between medical and surgical patients with regard to the incidence of new and unexpected findings on daily routine CXRs and the effect of new and unexpected CXR findings on daily care. In the ICU, daily routine CXRs seldom reveal unexpected, clinically relevant abnormalities, and they rarely prompt action. We propose that this diagnostic examination be abandoned in ICU patients.

  17. Low-Intensity Pulsed Ultrasound Prevents the Oxidative Stress Induced Endothelial-Mesenchymal Transition in Human Aortic Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Jiamin Li

    2018-02-01

    Full Text Available Background/Aims: Endothelial-mesenchymal transition (EndMT has been shown to take part in the generation and progression of diverse diseases, involving a series of changes leading to a loss of their endothelial characteristics and an acquirement of properties typical of mesenchymal cells. Low-intensity pulsed ultrasound (LIPUS is a new therapeutic option that has been successfully used in fracture healing. However, whether LIPUS can inhibit oxidative stress-induced endothelial cell damages through inhibiting EndMT remained unknown. This study aimed to investigate the protective effects of LIPUS against oxidative stress-induced endothelial cell damages and the underlying mechanisms. Methods: EndMT was induced by H2O2 (100 µm for seven days. Human aortic endothelial cells (HAECs were exposed to H2O2 with or without LIPUS treatment for seven days. The expression of EndMT markers (CD31, VE-cadherin, FSP1 and α-SMA were analyzed. The levels of total and phosphorylated PI3K and AKT proteins were detected by Western Blot analysis. Cell chemotaxis was determined by wound healing and transwell assay. Results: LIPUS relieved EndMT by decreasing ROS accumulation and increasing activation of the PI3K signaling cascade. LIPUS alleviated the migration of EndMT-derived mesenchymal-like cells through reducing extracellular matrix (ECM deposition that is associated with matrix metallopeptidase (MMP proteolytic activity and collagen production. Conclusion: LIPUS produces cytoprotective effects against oxidative injuries to endothelial cells through suppressing the oxidative stress-induced EndMT, activating the PI3K/AKT pathway under oxidative stress, and limiting cell migration and excessive ECM deposition.

  18. Mesh construction and evaluation of the stress intensity factor for the semi-elliptical surface cracks

    International Nuclear Information System (INIS)

    Kim, Jong Wook; Lee, Gyu Mahn; Jeong, Kyeong Hoon; Kim, Tae Wan; Park, Keun Bae

    2001-01-01

    As actual cracks found in practical structures are mostly three-dimensional surface cracks, such cracks give rise to the important problem when the structural integrity is evaluated in a viewpoint of fracture mechanics. The case of a semi-elliptical surface crack is more complicated than that of the embedded elliptical crack since the crack front intersects the free surface. Therefore, the exact expression of stress field according to the boundary condition can be the prior process for the structural integrity evaluation . The commercial code, I-DEAS does not provide the family of strain singular element for the cracked-body analysis. This means that the user cannot make use of the pre-processing function of I-DEAS effectively. But I-DEAS has the capability to hold input data in common with computational fracture mechanics program like ABAQUS. Hence, user can construct the optimized analysis method for the generation of input data of program like ABAQUS using the I-DEAS. In the present study, a procedure for the generation of input data for the optimized 3-dimensional computational fracture mechanics is developed as a series of effort to establish the structural integriyt evaluation procedure of SMART reactor vessel assembly. Input data for the finite element analysis are made using the commercial code, I-DEAS program, The stress analysis is performed using the ABAQUS. To demonstrate the validation of the developed procedure in the present sutdy, semi-elliptic surface crack in a half space subjected to uniform tension are solved, and the effects of crack configuration ratio are discussed in detail. The numerical results are presented and compared to those presented by Raju and Newman. Also, we have established the structural integrity evaluation procedure through the 3-D crack modeling

  19. Structural damping values as a function of dynamic response stress and deformation levels

    International Nuclear Information System (INIS)

    Stevenson, J.D.

    1980-01-01

    Damping as it is normally defined is the means by which the response motion of a structural system is reduced as the result of energy losses. However, as used in the context of nuclear plant design, the effects of changes in structural stiffness, geometry, support configuration, and modulus of elasticity are also usually lumped under the general heading of damping in current design methods. For convenience in structural design, damping in usually assumed as viscous in nature and in recognition of its use in modal response spectrum dynamic analysis is normally expressed as a percent of critical. In general, it should be understood that damping as used in design or analysis of nuclear plants is an experimentally determined factor which is used to make the results of linear elasticity analysis of dynamic systems agree reasonably well with observed experimental results. In this paper, damping data existing in the open literature applicable to nuclear power plant structures and equipment is summarized and statistically analyzed. Results of this analysis are used to develop damping trend curves which predict applicable damping values to be used in design at various levels of stress or deformation. (orig.)

  20. Value of transient dilation of the left ventricular cavity on stress thallium scintigraphy

    International Nuclear Information System (INIS)

    Sugihara, Hiroki; Shiga, Kouji; Umamoto, Ikuo

    1991-01-01

    This study was undertaken to evaluate the value of transient dilation of the left ventricular cavity on stress thallium scintigraphy in 80 patients with ischemic heart disease (IHD) and 50 with hypertrophic cardiomyopathy (HCM). Twenty persons without either coronary artery stenosis or heart disease were served as controls. Areas surrounded by maximum count points on the line of each 10deg on the short axis slice through the mid-cavity of the left ventricle were obtained at 10 minutes and at 3 hours after exercise. Transient dilation index (TDI) was obtained by dividing the area on early image by that on delayed image. TDI was significantly higher in patients with two or three vessel disease in the IHD group than the control group. High TDI was observed in 8% for one vessel disease, 40% for two vessel disease, and 80% for three vessel disease, contributing to the detection of multivessel IHD. In the HCM group of 80 patients, 24 (48%) had high TDI which was frequently associated with a history of chest pain and positive ECG findings at exercise. When these 24 HCM patients underwent exercise blood pool scintiscanning, left ventricular enddiastolic volume was similar before and at 10 minutes after exercise. These findings suggest that transient dilation of the left ventricular cavity after exercise may reflect subendocardial ischemia in both IHD and HCM. TDI would become a useful indicator for transient dilation of the left ventricular cavity. (N.K.)

  1. Effect of Lower and Upper Body High Intensity Training on Genes Associated with Cellular Stress Response.

    Science.gov (United States)

    Żychowska, Małgorzata; Kochanowicz, Andrzej; Kochanowicz, Kazimierz; Mieszkowski, Jan; Niespodziński, Bartłomiej; Sawczyn, Stanisław

    2017-01-01

    This study aimed to compare the effect of upper and lower body high intensity exercise (HIE) on select gene expression in athletes. Fourteen elite male artistic gymnasts (age 20.9 ± 2.6 years; weight 68.6 ± 7.2 kg; fat free mass 63.6 ± 6.7 kg; height 1.70 ± 0.04 m) performed lower and upper body 30 s Wingate Tests (WAnTs) before and after eight weeks of specific HIIT. Two milliliters of blood was collected before and after (5, 30 min, resp.) lower and upper body WAnTs, and select gene expression was determined by PCR. Eight weeks of HIIT caused a significant increase in maximal power (722 to 751 Wat), relative peak power in the lower body WAnTs (10.1 to 11 W/kg), mean power (444 to 464 W), and relative mean power (6.5 to 6.8 W/kg). No significant differences in lower versus upper body gene expression were detected after HIIT, and a significant decrease in the IL6/IL10 ratio was observed after lower (-2 ∧ 0.57 p = 0.0019) and upper (-2 ∧ 0.5 p = 0.03) WAnTs following eight weeks of HIIT. It is hypothesized that a similar adaptive response to exercise may be obtained by lower and upper body exercise.

  2. Low-intensity laser irradiation at 660 nm stimulates cytochrome c oxidase in stressed fibroblast cells.

    Science.gov (United States)

    Houreld, Nicolette N; Masha, Roland T; Abrahamse, Heidi

    2012-07-01

    Low-intensity laser irradiation (LILI) has been used to modulate a variety of biological processes, including diabetic wound healing. The mechanism of action is thought to exist primarily with the mitochondria. This study aimed to determine the effect of irradiation on normal, diabetic, and ischemic mitochondrial electron transport chain (ETC) complexes. Normal, diabetic and ischemic human skin fibroblast mitochondria were irradiated in vitro at a wavelength of 660 nm and a fluence of either 5 or 15 J/cm(2). Non-irradiated mitochondria served as controls. Enzyme activities of mitochondrial complexes I, II, III, and IV were determined immediately post-irradiation. Normal, diabetic, and ischemic cells were irradiated and adenosine triphosphate (ATP) and active mitochondria were determined by luminescence and fluorescent microscopy, respectively. Irradiated diabetic mitochondria at a fluence of 15 J/cm(2) showed a significant decrease in complex III activity (P < 0.05). Normal (P < 0.01) and diabetic (P < 0.05) mitochondria irradiated at either 5 or 15 J/cm(2) showed a significant increase in complex IV activity. ATP results showed a significant increase in irradiated normal cells (5 J/cm(2); P < 0.05) and diabetic cells (15 J/cm(2); P < 0.01). There was a higher accumulation of active mitochondria in irradiated cells than non-irradiated cells. Irradiation at 660 nm has the ability to influence mitochondrial enzyme activity, in particular cytochrome c oxidase. This leads to increased mitochondrial activity and ATP synthesis. Copyright © 2012 Wiley Periodicals, Inc.

  3. Effect of Lower and Upper Body High Intensity Training on Genes Associated with Cellular Stress Response

    Directory of Open Access Journals (Sweden)

    Małgorzata Żychowska

    2017-01-01

    Full Text Available This study aimed to compare the effect of upper and lower body high intensity exercise (HIE on select gene expression in athletes. Fourteen elite male artistic gymnasts (age 20.9±2.6 years; weight 68.6±7.2 kg; fat free mass 63.6±6.7 kg; height 1.70±0.04 m performed lower and upper body 30 s Wingate Tests (WAnTs before and after eight weeks of specific HIIT. Two milliliters of blood was collected before and after (5, 30 min, resp. lower and upper body WAnTs, and select gene expression was determined by PCR. Eight weeks of HIIT caused a significant increase in maximal power (722 to 751 Wat, relative peak power in the lower body WAnTs (10.1 to 11 W/kg, mean power (444 to 464 W, and relative mean power (6.5 to 6.8 W/kg. No significant differences in lower versus upper body gene expression were detected after HIIT, and a significant decrease in the IL6/IL10 ratio was observed after lower (−2∧0.57 p=0.0019 and upper (−2∧0.5 p=0.03 WAnTs following eight weeks of HIIT. It is hypothesized that a similar adaptive response to exercise may be obtained by lower and upper body exercise.

  4. Long-term prognostic value of transesophageal atrial pacing stress echocardiography.

    Science.gov (United States)

    Płońska, Edyta; Kasprzak, Jarosław D; Kornacewicz-Jach, Zdzisława

    2005-07-01

    The aim of our study was to evaluate the long-term prognostic value of transesophageal atrial pacing stress echocardiography (TAPSE) for the prediction of cardiovascular events (myocardial infarction) and mortality at 10-year follow-up. TAPSE was applied as a diagnostic modality in 93 consecutive patients (mean age 45 +/- 8 years) who were diagnosed for the cause of chest pain. Long-term follow-up data were obtained from 87 (94%) patients with a mean duration of follow-up of 92 +/- 4 months. Stress echocardiography was performed using TAPSE with a mean pacing rate of 142 +/- 18/min. Predefined cardiac events occurred during the follow-up period in 45 (52%) patients, including 24 (28%) with hard end points: 10 (12%) with nonfatal myocardial infarction and 17 who died (events overlap). Positive result of TAPSE was found in 47 (54%) patients and among those with positive TAPSE result, 16 died (94% of total mortality) and 21 had a hard event (death or infarction-88% of total prevalence). Survival free from hard events was noted in 37 (92%) patients with negative TAPSE and only in 26 (55%) of those with positive TAPSE ( P = .001). Independent predictive factors for mortality were TAPSE positivity (relative risk with 95% confidence interval [RR/CI] = 39.6 [36.3-42.9], P = .0006) and diabetes (RR/CI = 10.2 [8.6-11.8], P = .0026). Independent predictive factors for myocardial infarction were diabetes (RR/CI = 8.1 [6.3-9.9], P = .0186) and significant coronary stenosis in angiography (RR/CI = 9.0 [6.8-11.2], P = .0479). Independent predictive factors for death or nonfatal myocardial infarction were TAPSE positivity (RR/CI = 12.3 [11.1-13.3], P = .0001) and diabetes (RR/CI = 7.0 [5.8-8.2], P = .0018). Positive TAPSE result carries long-term prognostic information regarding mortality and risk of myocardial infarction that can be used to identify patients requiring more aggressive treatment. Negative TAPSE allows highly accurate definition of low-risk population with

  5. Computation of stress intensity factors for nozzle corner cracks by various finite element procedures

    International Nuclear Information System (INIS)

    Broekhoven, M.J.G.

    1975-01-01

    The present study aims at deriving accurate K-factors for a series of 5 elliptical nozzle corner cracks of increasing size by various finite element procedures, using a three-level recursive substructuring scheme to perform the computations in an economic way on an intermediate size computer (IBM 360/65 system). A nozzle on a flat plate has been selected for subsequent experimental verification, this configuration being considered an adequate simulation of a nozzle on a shallow shell. The computations have been performed with the ASKA finite element system using mainly HEXEC-27 (incomplete quartic) elements. The geometry has been subdivided into 5 subnets with a total of 3515 nodal points and 6250 unknowns, two main nets and one hyper net. Each crack front is described by 11 nodal points and all crack front nodes are inserted in the hyper net, which allows for the realization of the successive crack geometries by changing only a relatively small hyper net (615 to 725 unknowns). Output data have been interpreted in terms of K-factors by the global energy method, the displacement method and the stress method. Besides, a stiffness derivative procedure, recently developed at Brown University, which takes full advantage of the finite element formulation to calculate local K-factors, has been applied. Finally it has been investigated whether sufficiently accurate results can be obtained by analyzing a considerably smaller part than one half of the geometry (as strictly required by symmetry considerations), using fixed boundary conditions derived from a far cheaper analysis of the uncracked structure

  6. Prognostic value and staging classification of retropharyngeal lymph node metastasis in nasopharyngeal carcinoma patients treated with intensity-modulated radiotherapy.

    Directory of Open Access Journals (Sweden)

    Ling-Long Tang

    Full Text Available BACKGROUND: The development of intensity-modulated radiotherapy (IMRT has revolutionized the management of nasopharyngeal carcinoma (NPC. The purpose of this study was to evaluate the prognostic value and classification of TNM stage system for retropharyngeal lymph node (RLN metastasis in NPC in the IMRT era. MATERIAL AND METHODS: We retrospectively reviewed data from 749 patients with biopsy-proven, non-metastatic NPC. All patients received IMRT as the primary treatment. Chemotherapy was administered to 86.2% (424/492 of the patients with stage III or IV disease. RESULTS: The incidence of RLN metastasis was 64.2% (481/749. Significant differences were observed in the 5-year disease-free survival (DFS; 70.6% vs. 85.4%, P<0.001 and distant metastasis-free survival (DMFS; 79.2% vs. 90.1%, P<0.001 rates of patients with and without RLN metastasis. In multivariate analysis, RLN metastasis was an independent prognostic factor for disease failure and distant failure (P = 0.005 and P = 0.026, respectively, but not for locoregional recurrence. Necrotic RLN metastases have a negative effect on disease failure, distant failure and locoregional recurrence in NPC with RLN metastasis (P = 0.003, P = 0.018 and P = 0.005, respectively. Survival curves demonstrated a significant difference in DFS between patients with N0 disease and N1 disease with only RLN metastasis (P = 0.020, and marginally statistically significant differences in DMFS and DFS between N1 disease with only RLN metastasis and other N1 disease (P = 0.058 and P = 0.091, respectively. In N1 disease, no significant differences in DFS were observed between unilateral and bilateral RLN metastasis (P = 0.994. CONCLUSIONS: In the IMRT era, RLN metastasis remains an independent prognostic factor for DFS and DMFS in NPC. It is still reasonable for RLN metastasis to be classified in the N1 disease, regardless of laterality. However, there is a need to investigate the feasibility of classifying RLN

  7. Posttraumatic stress disorder (PTSD in children after paediatric intensive care treatment compared to children who survived a major fire disaster

    Directory of Open Access Journals (Sweden)

    Last Bob F

    2008-05-01

    Full Text Available Abstract Background The goals were to determine the presence of posttraumatic stress disorder (PTSD in children after paediatric intensive care treatment, to identify risk factors for PTSD, and to compare this data with data from a major fire disaster in the Netherlands. Methods Children completed the Dutch Children's Responses to Trauma Inventory at three and nine months after discharge from the paediatric intensive care unit (PICU. Comparison data were available from 355 children survivors who completed the same questionnaire 10 months after a major fire disaster. Results Thirty-six children aged eight to 17 years completed questionnaires at three month follow-up, nine month follow-up, or both. More than one third (34.5% of the children had subclinical PTSD, while 13.8% were likely to meet criteria for PTSD. Maternal PTSD was the strongest predictor for child PTSD. There were no significant differences in (subclinical PTSD symptoms either over time or compared to symptoms of survivors from the fire disaster. Conclusion This study shows that a considerable number of children have persistent PTSD after PICU treatment. Prevention of PTSD is important to minimize the profound adverse effects that PTSD can have on children's well-being and future development.

  8. Standard test method for determining a threshold stress intensity factor for environment-assisted cracking of metallic materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This test method covers the determination of the environment-assisted cracking threshold stress intensity factor parameters, KIEAC and KEAC, for metallic materials from constant-force testing of fatigue precracked beam or compact fracture specimens and from constant-displacement testing of fatigue precracked bolt-load compact fracture specimens. 1.2 This test method is applicable to environment-assisted cracking in aqueous or other aggressive environments. 1.3 Materials that can be tested by this test method are not limited by thickness or by strength as long as specimens are of sufficient thickness and planar size to meet the size requirements of this test method. 1.4 A range of specimen sizes with proportional planar dimensions is provided, but size may be variable and adjusted for yield strength and applied force. Specimen thickness is a variable independent of planar size. 1.5 Specimen configurations other than those contained in this test method may be used, provided that well-established stress ...

  9. Montmorency Cherries Reduce the Oxidative Stress and Inflammatory Responses to Repeated Days High-Intensity Stochastic Cycling

    Directory of Open Access Journals (Sweden)

    Phillip G. Bell

    2014-02-01

    Full Text Available This investigation examined the impact of Montmorency tart cherry concentrate (MC on physiological indices of oxidative stress, inflammation and muscle damage across 3 days simulated road cycle racing. Trained cyclists (n = 16 were divided into equal groups and consumed 30 mL of MC or placebo (PLA, twice per day for seven consecutive days. A simulated, high-intensity, stochastic road cycling trial, lasting 109 min, was completed on days 5, 6 and 7. Oxidative stress and inflammation were measured from blood samples collected at baseline and immediately pre- and post-trial on days 5, 6 and 7. Analyses for lipid hydroperoxides (LOOH, interleukin-6 (IL-6, tumor necrosis factor-alpha (TNF-α, interleukin-8 (IL-8, interleukin-1-beta (IL-1-β, high-sensitivity C-reactive protein (hsCRP and creatine kinase (CK were conducted. LOOH (p < 0.01, IL-6 (p < 0.05 and hsCRP (p < 0.05 responses to trials were lower in the MC group versus PLA. No group or interaction effects were found for the other markers. The attenuated oxidative and inflammatory responses suggest MC may be efficacious in combating post-exercise oxidative and inflammatory cascades that can contribute to cellular disruption. Additionally, we demonstrate direct application for MC in repeated days cycling and conceivably other sporting scenario’s where back-to-back performances are required.

  10. Racial-Ethnic Disparities in Maternal Parenting Stress: The Role of Structural Disadvantages and Parenting Values

    OpenAIRE

    Nomaguchi, Kei; House, Amanda N.

    2013-01-01

    Although researchers contend that racial-ethnic minorities experience more stress than whites, knowledge of racial-ethnic disparities in parenting stress is limited. Using a pooled time-series analysis of data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998–99 (n = 11,324), we examine racial-ethnic differences in maternal parenting stress, with a focus on structural and cultural explanations and variations by nativity and child age. In kindergarten, black mothers, albe...

  11. Value of lateral blood pool imaging in patients with suspected stress fractures of the tibia.

    Science.gov (United States)

    Mohan, Hosahalli K; Clarke, Susan E M; Centenara, Martin; Lucarelli, Amanda; Baron, Daniel; Fogelman, Ignac

    2011-03-01

    To critically evaluate the use of lateral blood pool imaging in athletes with lower limb pain and with a clinical suspicion of stress fracture. Two experienced nuclear medicine physicians evaluated 3-phase bone scans using 99mTc-methylene diphosphonate performed in 50 consecutive patients referred from a specialist sports injury clinic for suspected tibial stress fracture. The vascularity to the tibia as seen on the blood pool (second phase) images in the anterior/posterior views was compared with the lateral/medial view assessments. Stress fractures were presumed to be present when on the delayed images (third phase) there was a focal or fusiform area of increased tracer uptake involving the tibial cortex. Shin splints which are a recognized cause of lower limb pain in athletes mimicking stress fracture were diagnosed if increased tracer uptake was seen extending along the posterior tibial surface with no significant focal or fusiform area of uptake within this. Inter-reviewer agreement for the assessment of vascularity was also assessed using Cohen's Kappa scores. Twenty-four stress fractures in 24 patients and 66 shin splints in 40 patients were diagnosed. In 18 patients stress fracture and shin splints coexisted. In 10 patients no tibial pathology was identified. Of the 24 patients diagnosed with stress fractures, lateral/medial blood pool imaging was superior in the assessment of blood pool activity (P tibial stress fractures, lateral views of the tibia provide the optimal method for evaluation of vascularity. Prospective studies with quantitative or semi-quantitative assessment of skeletal vascularity could provide supplementary information relating to the pathophysiology of stress fractures, for example, the time scale of vascular changes after a tibial stress fracture, and potentially could have clinical relevance as to the assessment of the severity of stress fractures and their prognosis.

  12. Analysis of stress intensity factors for a new mechanical corrosion specimen; Analyse du facteur d`intensite de contrainte pour une nouvelle eprouvette de mecanique corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Rassineux, B; Crouzet, D; Le Hong, S

    1996-03-01

    Electricite de France is conducting a research program to determine corrosion cracking rates in the steam generators Alloy 600 tubes of the primary system. The objective is to correlate the cracking rates with the specimen stress intensity factor K{sub I}. One of the samples selected for the purpose of this study is the longitudinal notched specimen TEL (TEL: ``Tubulaire a Entailles Longitudinales``). This paper presents the analysis of the stress intensity factor and its experimental validation. The stress intensity factor has been evaluated for different loads using 3D finite element calculations with the Hellen-Parks and G({theta}) methods. Both crack initiation and propagation are considered. As an assessment of the method, the numerical simulations are in good agreement with the fatigue crack growth rates measured experimentally for TEL and compact tension (CT) specimens. (authors). 8 refs., 6 figs., 2 tabs.

  13. Vacuum expectation value of the stress tensor in an arbitrary curved background: The covariant point-separation method

    International Nuclear Information System (INIS)

    Christensen, S.M.

    1976-01-01

    A method known as covariant geodesic point separation is developed to calculate the vacuum expectation value of the stress tensor for a massive scalar field in an arbitrary gravitational field. The vacuum expectation value will diverge because the stress-tensor operator is constructed from products of field operators evaluated at the same space-time point. To remedy this problem, one of the field operators is taken to a nearby point. The resultant vacuum expectation value is finite and may be expressed in terms of the Hadamard elementary function. This function is calculated using a curved-space generalization of Schwinger's proper-time method for calculating the Feynman Green's function. The expression for the Hadamard function is written in terms of the biscalar of geodetic interval which gives a measure of the square of the geodesic distance between the separated points. Next, using a covariant expansion in terms of the tangent to the geodesic, the stress tensor may be expanded in powers of the length of the geodesic. Covariant expressions for each divergent term and for certain terms in the finite portion of the vacuum expectation value of the stress tensor are found. The properties, uses, and limitations of the results are discussed

  14. Parenting Values and Parenting Stress among Impoverished Village and Middle-Class Small City Mothers in the Dominican Republic

    Science.gov (United States)

    Foucault, Darlene C.; Schneider, Barry H.

    2009-01-01

    Poverty is known to influence parenting values, parenting stress, psychological adjustment, and social support according to North American research. The purpose of this study was to determine whether poverty might work in similar ways in a collectivistic Latin culture. The participants were primary caregivers in two distinct communities in the…

  15. A tailored relocation stress intervention programme for family caregivers of patients transferred from a surgical intensive care unit to a general ward.

    Science.gov (United States)

    Lee, Seul; Oh, HyunSoo; Suh, YeonOk; Seo, WhaSook

    2017-03-01

    To develop and examine a relocation stress intervention programme tailored for the family caregivers of patients scheduled for transfer from a surgical intensive care unit to a general ward. Family relocation stress syndrome has been reported to be similar to that exhibited by patients, and investigators have emphasised that nurses should make special efforts to relieve family relocation stress to maximise positive contributions to the well-being of patients by family caregivers. A nonequivalent control group, nonsynchronised pretest-post-test design was adopted. The study subjects were 60 family caregivers of patients with neurosurgical or general surgical conditions in the surgical intensive care unit of a university hospital located in Incheon, South Korea. Relocation stress and family burden were evaluated at three times, that is before intervention, immediately after transfer and four to five days after transfer. This relocation stress intervention programme was developed for the family caregivers based on disease characteristics and relocation-related needs. In the experimental group, relocation stress levels significantly and continuously decreased after intervention, whereas in the control group, a slight nonsignificant trend was observed. Family burden levels in the control group increased significantly after transfer, whereas burden levels in the experimental group increased only marginally and nonsignificantly. No significant between-group differences in relocation stress or family burden levels were observed after intervention. Relocation stress levels of family caregivers were significantly decreased after intervention in the experimental group, which indicates that the devised family relocation stress intervention programme effectively alleviated family relocation stress. The devised intervention programme, which was tailored to disease characteristics and relocation-related needs, may enhance the practicality and efficacy of relocation stress

  16. The predictive value of early maladaptive schemas in paranoid responses to social stress.

    Science.gov (United States)

    Sundag, Johanna; Ascone, Leonie; Lincoln, Tania M

    2018-01-01

    Social stress and negatively valenced cognitive representations of the self (self-schemas) play an important role in the formation of delusions. However, it has not been investigated whether and which self-schemas explain paranoid responses to social stress. Building on the framework of schema theory, the aim of this study was thus to investigate whether more pronounced early maladaptive schemas (EMSs) were associated with increased paranoid ideation after a social stress induction in patients with persecutory delusions (PD). Patients with PD (n = 20) and healthy controls (n = 40) were assessed for EMSs with the Young Schema Questionnaire. They were then exposed to a social stress situation in which they were socially excluded in a Cyberball paradigm. Prior to and after the social stress induction, paranoid symptoms were assessed. Patients with PD responded with a stronger increase in paranoia and revealed a significantly higher EMS total score compared to the healthy controls. As expected, higher increases in paranoia following the social stress were accounted for by higher EMS total scores. Exploratory analyses showed that particularly the specific EMSs Defectiveness/Shame and Enmeshment/Undeveloped Self were associated with the increase in paranoia. EMSs are associated with stress-related symptom increases in patients with PD. It thus seems worthwhile to further investigate the relevance of specific schemas for paranoia. The findings also suggest that addressing EMSs in psychological treatment of patients with PD holds potential. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Value of overall treatment time on the effect of intensity-modulated radiotherapy for locally advanced nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Su Shengfa; Lu Taixiang; Zhao Chong; Han Fei; Xiao Weiwei; Li Jiaxin; Chen Chunyan

    2010-01-01

    Objective: To investigate the prognostic value of overall treatment time (OTT) for locally advanced nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT). Methods: From May 2001 to April 2007, 376 patients with locally advanced NPC treated with IMRT were retrospectively analyzed. All patients were divided into OTT≤45 days group and OTT >45 days group. The treatment outcomes between the two groups were analyzed. Results: Between the groups with OTT≤45 days and OTT > 45 days, the 2-year local control rate (LCR) was 94.9% and 93.1% (χ 2 = 2.83, P > 0.05) for all patients, 96.3% and 98.7% (χ 2 =2.83, P>0.05) for patients with T 3 disease, 92.2% and 83.1%(χ 2 = 6.30, P 4 , and 93.1% and 97.5% (χ 2 = 4.69, P = 0.030) when chemotherapy was concurrently administered.The 2-year LCR was 98%, 96% and 93% (χ 2 = 2.20, P = 0.531) for patients with treatment interruption before, within and after the 3rd week of IMRT, The Cox regression analysis found that OTT was an independent prognostic factor for LCR in T 4 disease.The Linear regression showed that the 2-year LCR was decreased by 2.7% per day of delay. Between the groups with OTT≤45 days and OTT >45 days, the 2-year estimated disease-specific survival (DSS), distant metastasis-free survival (DMFS) and overall survival (OS) were 84.1% vs.78.7% (χ 2 = 0.02, P = 0.881), 87.0% vs.86.1% (χ 2 = 0.85, P = 0.358), and 91.7% vs. 92.2% (χ 2 = 0.06, P = 0.806), respectively.The further stratified analysis found that the DSS, DMFS and OS were similar between the two groups in T 3 (83.7% vs. 83.2%, χ 2 =0.07, P=0.798; 86.6% vs. 85.7%, χ 2 =0.02, P = 0.898 ; and 93.7% vs. 94.8%, χ 2 =0.03, P=0.862) and T 4 disease (81.4% vs. 72.3%, χ 2 = 0.16, P = 0.687; 82.6% vs. 86.9%, χ 2 = 1.78, P =0.182; and 88.3% vs. 87.5%, χ 2 =0.60, P =0.438).In multivariate analysis, T-stage and N-stage were the independent prognostic factors for both DFS and OS, and N-stage was the independent prognostic

  18. Risk factors for the development of post-traumatic stress disorder and coping strategies in mothers and fathers following infant hospitalisation in the neonatal intensive care unit.

    Science.gov (United States)

    Aftyka, Anna; Rybojad, Beata; Rosa, Wojciech; Wróbel, Aleksandra; Karakuła-Juchnowicz, Hanna

    2017-12-01

    The aim of this study was to identify the potential risk factors for the development of post-traumatic stress disorder in mothers and fathers following infant hospitalisation in the neonatal intensive care unit. The development of neonatal intensive care units has increased the survival rate of infants. However, one of the major parental problems is post-traumatic stress disorder. An observational study covered 125 parents (72 mothers and 53 fathers) of infants aged 3-12 months who were hospitalised in the neonatal intensive care unit during the neonatal period. Third-referral neonatal intensive care unit. Several standardised and self-reported research tools were used to estimate the level of post-traumatic stress symptoms (Impact Event Scale-Revised), perceived stress (Perceived Stress Scale) and coping strategies (COPE Inventory). The respondents also completed a Parent and Infant Characteristic Questionnaire. The mothers and fathers did not differ in their parental and infant characteristics. Post-traumatic stress disorder was present in 60% of the mothers and 47% of the fathers. Compared to the fathers, the mothers felt greater stress (p = .020) and presented a higher severity of post-traumatic stress disorder (p stress disorder in the mothers. In the fathers, an Apgar test at 1 min after birth (p = .030) and a partner's post-traumatic stress disorder (p = .038) were related to post-traumatic stress disorder. The mothers compared to the fathers were more likely to use strategies such as: positive reinterpretation and growth, focusing on and venting of emotions, instrumental social support, religious coping and acceptance. In the fathers, the predictors included an Apgar score at 1 min after birth, a lack of congenital anomalies in the child and mental disengagement. Risk factors for post-traumatic stress disorder, as well as coping strategies, differ in women compare to men. Knowledge of risk factors for post-traumatic stress disorder, specific to

  19. Effect of Exercise Intensity on Neurotrophic Factors and Blood-Brain Barrier Permeability Induced by Oxidative-Nitrosative Stress in Male College Students.

    Science.gov (United States)

    Roh, Hee-Tae; Cho, Su-Youn; Yoon, Hyung-Gi; So, Wi-Young

    2017-06-01

    We investigated the effects of aerobic exercise intensity on oxidative-nitrosative stress, neurotrophic factor expression, and blood-brain barrier (BBB) permeability. Fifteen healthy men performed treadmill running under low-intensity (LI), moderate-intensity (MI), and high-intensity (HI) conditions. Blood samples were collected immediately before exercise (IBE), immediately after exercise (IAE), and 60 min after exercise (60MAE) to examine oxidative-nitrosative stress (reactive oxygen species [ROS]; nitric oxide [NO]), neurotrophic factors (brain-derived neurotrophic factor [BDNF]; nerve growth factor [NGF]), and blood-brain barrier (BBB) permeability (S-100β; neuron-specific enolase). ROS concentration significantly increased IAE and following HI (4.9 ± 1.7 mM) compared with that after LI (2.8 ± 1.4 mM) exercise (p exercise (p exercise (p exercise (p exercise (p .05). Moderate- and/or high-intensity exercise may induce higher oxidative-nitrosative stress than may low-intensity exercise, which can increase peripheral neurotrophic factor levels by increasing BBB permeability.

  20. Strain-encoded cardiac MRI as an adjunct for dobutamine stress testing: incremental value to conventional wall motion analysis.

    Science.gov (United States)

    Korosoglou, Grigorios; Lossnitzer, Dirk; Schellberg, Dieter; Lewien, Antje; Wochele, Angela; Schaeufele, Tim; Neizel, Mirja; Steen, Henning; Giannitsis, Evangelos; Katus, Hugo A; Osman, Nael F

    2009-03-01

    High-dose dobutamine stress MRI is safe and feasible for the diagnosis of coronary artery disease (CAD) in humans. However, the assessment of cine scans relies on the visual interpretation of regional wall motion, which is subjective. Recently, strain-encoded MRI (SENC) has been proposed for the direct color-coded visualization of myocardial strain. The purpose of our study was to compare the diagnostic value of SENC with that provided by conventional wall motion analysis for the detection of inducible ischemia during dobutamine stress MRI. Stress-induced ischemia was assessed by wall motion analysis and by SENC in 101 patients with suspected or known CAD and in 17 healthy volunteers who underwent dobutamine stress MRI in a clinical 1.5-T scanner. Quantitative coronary angiography deemed as the standard reference for the presence or absence of significant CAD (> or =50% diameter stenosis). On a coronary vessel level, SENC detected inducible ischemia in 86 of 101 versus 71 of 101 diseased coronary vessels (P or =50% stenosis (area under the curve, 0.96; SE, 0.01; 95% CI, 0.94 to 0.98; P<0.001). The direct color-coded visualization of strain on MR images is a useful adjunct for dobutamine stress MRI, which provides incremental value for the detection of CAD compared with conventional wall motion readings on cine images.

  1. Time series analysis of blood oxidative stress value in irradiated rats

    International Nuclear Information System (INIS)

    Kaneko, Takashi; Goto, Jun; Nomiya, Takuma; Nemoto, Kenji

    2011-01-01

    Indirect effect of ionizing-radiation causes free radicals and reactive oxgen species (ROS). These ROS interact with DNA or other organella, and cause oxidative damage to nucleic acids, membrane lipoprotein, mitchondria and others. The purpose of this study is to evaluate oxidative damage by irradiation using d-ROMs test. Electron beam was irradiated to the thigh of Wistar strain female rats, and reactive oxygen metabolites in the blood from these rats were measured and analysed. From the results, 2 Gy group shows significantly higher oxidative stress level than those of 0 Gy group especially in day 3 after irradiation. This oxidative stress definitely seemed to be caused by exposure to ionizing-radiation. In contrast, the group of 30 Gy-irradiation showed no significant increase of oxidative stress level. It was thought that oxidative stress caused by radiation was neutralized by expression of stress-induced antioxidant enzymes. These data resulted that d-ROMs test is useful for measuring oxidative stress levels of irradiated mammalian animals. (author)

  2. Psychological rumination and recovery from work in intensive care professionals: associations with stress, burnout, depression and health.

    Science.gov (United States)

    Vandevala, Tushna; Pavey, Louisa; Chelidoni, Olga; Chang, Nai-Feng; Creagh-Brown, Ben; Cox, Anna

    2017-01-01

    The work demands of critical care can be a major cause of stress in intensive care unit (ICU) professionals and lead to poor health outcomes. In the process of recovery from work, psychological rumination is considered to be an important mediating variable in the relationship between work demands and health outcomes. This study aimed to extend our knowledge of the process by which ICU stressors and differing rumination styles are associated with burnout, depression and risk of psychiatric morbidity among ICU professionals. Ninety-six healthcare professionals (58 doctors and 38 nurses) who work in ICUs in the UK completed a questionnaire on ICU-related stressors, burnout, work-related rumination, depression and risk of psychiatric morbidity. Significant associations between ICU stressors, affective rumination, burnout, depression and risk of psychiatric morbidity were found. Longer working hours were also related to increased ICU stressors. Affective rumination (but not problem-solving pondering or distraction detachment) mediated the relationship between ICU stressors, burnout, depression and risk of psychiatric morbidity, such that increased ICU stressors, and greater affective rumination, were associated with greater burnout, depression and risk of psychiatric morbidity. No moderating effects were observed. Longer working hours were associated with increased ICU stressors, and increased ICU stressors conferred greater burnout, depression and risk of psychiatric morbidity via increased affective rumination. The importance of screening healthcare practitioners within intensive care for depression, burnout and psychiatric morbidity has been highlighted. Future research should evaluate psychological interventions which target rumination style and could be made available to those at highest risk. The efficacy and cost effectiveness of delivering these interventions should also be considered.

  3. Stress Hormone and Reproductive System in Response to Honey Supplementation Combined with Different Jumping Exercise Intensities in Female Rats

    Directory of Open Access Journals (Sweden)

    Maryam Mosavat

    2014-01-01

    Full Text Available This study was performed to determine the effects of 8-week honey supplementation combined with different jumping exercise intensities on serum cortisol, progesterone, estradiol, and reproductive organs. Eighty-four 9-week-old female rats were divided into 7 groups: baseline controls (C0, sedentary group (C, 20 and 80 jumps per day (Ex20J, Ex80J, honey (H, and combined honey with 20 and 80 jumps per day (HEx20J, HEx80J groups. Jumping exercise was performed at 5 days/week and honey was given at a dosage of 1 g/kg body weight/day for 7 days/week. The level of serum cortisol was higher in Ex20J and Ex80J compared to C. There was significantly lower value of serum cortisol in HEx20J compared to Ex80J. Serum progesterone levels were significantly lower in Ex20J and Ex80J compared to C. However, serum progesterone levels were significantly higher in HEx20J and HEx80J compared to Ex20J and Ex80J. Relative uterine weights were significantly greater in HEx20J compared to C and HEx80J, respectively. There was no significant difference in estradiol level and relative ovarian weights among all the groups. Therefore, honey elicited beneficial effects in reducing the increase of cortisol and in increasing the reduce of progesterone levels induced by different intensities jumping exercise in female rats.

  4. Molt-associated changes in hematologic and plasma biochemical values and stress hormone levels in African penguins (Spheniscus demersus).

    Science.gov (United States)

    Mazzaro, Lisa M; Meegan, Jenny; Sarran, Delphine; Romano, Tracy A; Bonato, Vinicius; Deng, Shibing; Dunn, J Lawrence

    2013-12-01

    Handling, including blood collection, has often been discouraged in molting penguins because it is considered an additional stress imposed on birds already experiencing major physiologic stress associated with molting. To evaluate the degree of physiologic stress posed by molting, we compared the hematologic and plasma biochemical values and hormone levels of molting and nonmolting African penguins, Spheniscus demersus. Five male and 5 female penguins randomly chosen were given complete physical examinations, were weighed, and blood samples were taken at 7 time points before, during, and after the molt. Data were analyzed by linear mixed-model analysis of variance. Throughout the study, behavior and appetite remained normal. Catecholamine levels were highly variable within and among subjects, whereas mean corticosterone levels were significantly different between baseline, molt, and postmolt values. Significant differences from baseline values were observed in many of the hematologic analytes; however, only decreases in hematocrit and red blood cell count values were considered clinically significant. Anemia due to experimentally induced blood loss as a possible cause of the significant hematologic changes was ruled out based on results of a follow-up control study during the nonmolt season, which showed no significant changes in hematocrit level or total red blood cell counts when using similar sampling protocols, which indicates that these changes were associated with molt.

  5. Stress

    Science.gov (United States)

    ... can be life-saving. But chronic stress can cause both physical and mental harm. There are at least three different types of stress: Routine stress related to the pressures of work, family, and other daily responsibilities Stress brought about ...

  6. Application of the virtual crack closure technique to calculate stress intensity factors for through cracks with an oblique elliptical crack front

    NARCIS (Netherlands)

    Fawaz, S.

    1998-01-01

    Fractographic observations on fatigue tested 2024 T3 clad aluminium riveted lap-splice joints indicate oblique fronts after the initial surface or corner crack at a rivet hole has penetrated through the sheet thichness. No stress intensity factor solutions are available for this geometry subjected

  7. Threshold stress intensity factor for delayed hydride cracking of a recrystallized N18 alloy plate along the rolling direction

    Energy Technology Data Exchange (ETDEWEB)

    Sun Chao, E-mail: sunchaonpic@yahoo.com.c [National Key Laboratory for Nuclear Fuel and Materials, Nuclear Power Institute of China, P.O. Box 436, Chengdu 610041 (China); Tan Jun; Ying Shihao; Peng Qian [National Key Laboratory for Nuclear Fuel and Materials, Nuclear Power Institute of China, P.O. Box 436, Chengdu 610041 (China); Li Cong [Department of R and D, State Nuclear Power Technology Corporation Limited, Beijing (China)

    2010-11-15

    The objective of this study is to obtain the threshold stress intensity factor, K{sub IH}, for an initiation of delayed hydride cracking in a recrystallized N18 (Zr-Sn-Nb-Fe-Cr) alloy plate which was manufactured in China, gaseously charged with 60 ppm of hydrogen by weight. By using both the load increasing method and load drop method, the K{sub IH}'s along the rolling direction were investigated over a temperature range of 150-255 {sup o}C. The results showed that K{sub IH} along the rolling direction was found to be higher in the load increasing method than that in the load drop method. In the load increasing method, K{sub IH}'s of the N18 alloy plate appeared to be in the range of 31-32.5MPa{radical}(m), and K{sub IH} in the load drop method appeared to be in the range of 27.5-28.6MPa{radical}(m). This means that the N18 alloy plate has high tolerance for DHC initiation along the rolling direction. The texture of a N18 alloy plate was investigated using an X-ray diffraction and the K{sub IH} was discussed based on texture and analytically as a function of the tilting angle of hydride habit planes to the cracking plane.

  8. Threshold stress intensity factor for delayed hydride cracking of a recrystallized N18 alloy plate along the rolling direction

    International Nuclear Information System (INIS)

    Sun Chao; Tan Jun; Ying Shihao; Peng Qian; Li Cong

    2010-01-01

    The objective of this study is to obtain the threshold stress intensity factor, K IH , for an initiation of delayed hydride cracking in a recrystallized N18 (Zr-Sn-Nb-Fe-Cr) alloy plate which was manufactured in China, gaseously charged with 60 ppm of hydrogen by weight. By using both the load increasing method and load drop method, the K IH 's along the rolling direction were investigated over a temperature range of 150-255 o C. The results showed that K IH along the rolling direction was found to be higher in the load increasing method than that in the load drop method. In the load increasing method, K IH 's of the N18 alloy plate appeared to be in the range of 31-32.5MPa√(m), and K IH in the load drop method appeared to be in the range of 27.5-28.6MPa√(m). This means that the N18 alloy plate has high tolerance for DHC initiation along the rolling direction. The texture of a N18 alloy plate was investigated using an X-ray diffraction and the K IH was discussed based on texture and analytically as a function of the tilting angle of hydride habit planes to the cracking plane.

  9. Investigation of the Stress Intensity Limits of ASME Section III Div.5 for Structure Design Criteria of SFR Fuel Assembly

    International Nuclear Information System (INIS)

    Choo, Jin-Yup; Kim, Hyung-Kyu; Cheon, Jin-Sik

    2017-01-01

    In this paper, the stress intensity limits, Sm and St of HT-9 were built for the structural criteria of an SFR fuel assembly. Sm is obtained from the ultimate strength. As for St, it is more complicated because of its dependency of time duration in addition to temperature. Following the definition of Smt, the method in the ASME Sec. III Div. 1, Subsec. NH was consulted. We found that the Sm is adopted as Smt under the temperature about 470 .deg. C which is relatively low temperature range and over 470 .deg. C with relatively short time duration as 1000 hours. And the St is adopted as Smt at over 470 .deg. C and long time duration over 34800 hours, and over 520 .deg. C and 104 hours too. And at over 570 .deg. C and 1000 hours, and at over 630 .deg. C and 100 hours, St is also adopted for Smt. To use the present result as design criteria, a stringent examination needs to be carried out, because those are calculated from the formulae of HT-9 without an experimental validation. Therefore, an experimental work on the mechanical properties of HT-9 will be necessary.

  10. Diagnostic value of stress-rest myocardial perfusion imaging in detection of coronary disease in elderly patients

    International Nuclear Information System (INIS)

    Han Pingping; Tian Yueqin; Fang Wei; Shen Rui; Yang Minfu; Wei Hongxing; Guo Xinhua; He Zuoxiang

    2009-01-01

    Objective: Coronary artery disease is one of the most common causes of death in elderly people. Yet, definite diagnosis is a dilemma due to the variety of symptoms and signs. The aim of this study was to evaluate the diagnostic value of nuclear stress-rest myocardial perfusion imaging(MPI) in detection of coronary disease in the elderly. Methods: Two hundred and five elderly subjects (≥60 years old, average of 67 ± 5) who were suspected to have coronary disease, underwent both stress-rest myocardial perfusion imaging (185 with exercise stress and 20 with adenosine stress) and coronary angiography (CAG). All had no pereutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). Coronary angiography was used as a 'golden standard' to evaluate the sensitivity, specificity and accuracy of the stress-rest myocardial perfusion imaging. χ 2 -test was used in data analysis with SPSS 15.0. Results: Among 205 patients. there were 57 patients with an abnormal CAG result and 148 patients with a normal result. Of the 57 patients, there were 30 one-, 19 two-, and 8 three-vessel stenosis. Fifteen were mild-, 17 were moderate-, 17 were severe stenosis, and 8 were totally occluded.About 63% (36/57) had positive stress-rest MPI. Of the 148 subjects who had a normal CAG, 135 had negative MPL. The sensitivity.specificity and accuracy of stress MPI were 63% (36/57), 91% (135/148) and 83% (171/205) in patient level.respectively. The di-agnostic sensitivities of stress-rest MPI for detection of one-, two-, and three-vessel stenosis were 57%(17/30), 58% (11/19) and 8/8, respectively. All 185 patients who underwent exemise stress MPI were divided into 2 groups according to whether the patients reached the target heart rate or not at the peak of the test. And 53 patients (29%) were group 1 (reached the target heart rate)and 132 patients (71%) were group 2 (did not reach the target heart rate). The sensitivity of group 1 wag higher than that of group 2, but with no

  11. Signal intensity changes of normal brain at varying high b-value diffusion-weighted images using 3.0T MR scanner

    International Nuclear Information System (INIS)

    Lee, Jin Hee; Sohn, Chul Ho; Choi, Jin Soo

    2003-01-01

    Using diffusion-weighted MR imaging (DWI), to evaluate the signal intensity characteristics of normal adult brain as diffusion gradient strength (b value) increases from 1,000 to 3,000 s/mm 2 . Twenty-one healthy volunteers with neither neurologic symptoms nor pathologic findings at axial and sagittal T2-weighted MR imaging were involved in this study. All images were obtained with a 3.0T MR scanner. Six sets of spin-echo echo-planar images were acquired in the axial plane using progressively increasing strengths of diffusion-sensitizing gradients (corresponding to b values of 0, 1,000, 1,500, 2,000, 2,500, and 3,000 s/mm 2 ). All imaging parameters other than TE remained constant. Changes in normal white-gray matter signal intensity observed at variable b-value DWI were qualitatively analysed, and the signal-to-noise ratios (SNRs) in six anatomic regions (frontal and parietal white matter, genu and splenium corporis callosi, the posterior limb of the internal capsule, and the thalamus) quantitatively, and the ratios were averaged and compared with the average SNR of 1,000 s/mm DWI. As gradient strength increased from 1,000 to 3,000 s/mm 2 , both gray-and white-matter structures diminished in signal intensity, and images obtained at a b value of 3,000 s/mm 2 appeared very noisy. White matter became progressively hyperintense to gray matter as the diffusion sensitizing gradient increased, especially at the centrum semiovale, the posterior limb of the internal capsule, and the splenium corporis callosi, but the genu corporis callosi; showed exceptional intermediate low signal intensity. At quantitative assessment, the signal-to-noise ratio decreased as the diffusion sensitizing gradient increased. Relative to the images obtained at a b value of 1,000 s/mm 2 , average SNRs were 0.71 (b=1,500 s/mm 2 ), 0.52 (b=2,000 s/mm 2 ), 0.41 (b=2,500 s/mm 2 ), 0.33 (b=3,000 s/mm 2 ). As the diffusion sensitizing gradient increased, the signal-to-noise ratio of brain structures

  12. Prognostic value of normal stress-only myocardial perfusion imaging: a comparison between conventional and CZT-based SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Yokota, Shu; Ottervanger, Jan Paul; Timmer, Jorik R. [Isala Hospital, Department of Cardiology, Zwolle (Netherlands); Mouden, Mohamed; Engbers, Elsemiek [Isala Hospital, Department of Cardiology, Zwolle (Netherlands); Isala Hospital, Department of Nuclear Medicine, Zwolle (Netherlands); Knollema, Siert; Jager, Pieter L. [Isala Hospital, Department of Nuclear Medicine, Zwolle (Netherlands)

    2016-02-15

    Single photon emission computed tomography (SPECT) myocardial perfusion imaging has proven to have prognostic importance in patients with suspected stable coronary artery disease (CAD). The recently introduced ultrafast cadmium zinc telluride (CZT)-based gamma cameras have been associated with less equivocal findings and more normal interpretations, allowing stress-only imaging to be performed more often. However, it is yet unclear whether normal stress-only CZT SPECT has comparable prognostic value as normally interpreted stress-only conventional SPECT. The study population consisted of 1,650 consecutive patients without known CAD with normal stress-only myocardial perfusion results with either conventional (n = 362) or CZT SPECT (n = 1,288). The incidence of major adverse cardiac events (MACE, all-cause death, non-fatal myocardial infarction and/or coronary revascularization) was compared between the conventional SPECT and CZT SPECT groups. Multivariable analyses using the Cox model were used to adjust for differences in baseline variables. Patients scanned with CZT were less often male (33 vs 39 %), had less often hypercholesterolaemia (41 vs 50 %) and had more often a family history of CAD (57 vs 49 %). At a median follow-up time of 37 months (interquartile range 28-45 months) MACE occurred in 68 patients. The incidence of MACE was 1.5 %/year in the CZT group, compared to 2.0 %/year in the conventional group (p = 0.08). After multivariate analyses, there was a trend to a lower incidence of MACE in the CZT SPECT group (hazard ratio 0.61, 95 % confidence interval 0.35-1.04, p = 0.07). The prognostic value of normal stress-only CZT SPECT is at least comparable and may be even better than that of normal conventional stress SPECT. (orig.)

  13. Prognostic value of stress echocardiography in women with high (⩾80%) probability of coronary artery disease

    OpenAIRE

    Davar, J; Roberts, E; Coghlan, J; Evans, T; Lipkin, D

    2001-01-01

    OBJECTIVE—To assess the prognostic significance of stress echocardiography in women with a high probability of coronary artery disease (CAD).
SETTING—Secondary and tertiary cardiology unit at a university teaching hospital.
PARTICIPANTS—A total of 135 women (mean (SD) age 63 (9) years) with pre-test probability of CAD ⩾80% were selected from a database of patients investigated by treadmill or dobutamine stress echocardiography between 1995 and 1998.
MAIN OUTCOME MEASURES—Patients were followe...

  14. On the effect of temperature on the threshold stress intensity factor of delayed hydride cracking in light water reactor fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Holston, Anna-MariaAlvarez; Stjarnsater, Johan [Studsvik Nuclear AB, Nykoping (Sweden)

    2017-06-15

    Delayed hydride cracking (DHC) was first observed in pressure tubes in Canadian CANDU reactors. In light water reactors, DHC was not observed until the late 1990s in high-burnup boiling water reactor (BWR) fuel cladding. In recent years, the focus on DHC has resurfaced in light of the increased interest in the cladding integrity during interim conditions. In principle, all spent fuel in the wet pools has sufficient hydrogen content for DHC to operate below 300°C. It is therefore of importance to establish the critical parameters for DHC to operate. This work studies the threshold stress intensity factor (K{sub IH}) to initiate DHC as a function of temperature in Zry-4 for temperatures between 227°C and 315°C. The experimental technique used in this study was the pin-loading testing technique. To determine the K{sub IH}, an unloading method was used where the load was successively reduced in a stepwise manner until no cracking was observed during 24 hours. The results showed that there was moderate temperature behavior at lower temperatures. Around 300°C, there was a sharp increase in K{sub IH} indicating the upper temperature limit for DHC. The value for K{sub IH} at 227°C was determined to be 2.6 ± 0.3 MPa √m.

  15. On the effect of temperature on the threshold stress intensity factor of delayed hydride cracking in light water reactor fuel cladding

    Directory of Open Access Journals (Sweden)

    Anna-Maria Alvarez Holston

    2017-06-01

    Full Text Available Delayed hydride cracking (DHC was first observed in pressure tubes in Canadian CANDU reactors. In light water reactors, DHC was not observed until the late 1990s in high-burnup boiling water reactor (BWR fuel cladding. In recent years, the focus on DHC has resurfaced in light of the increased interest in the cladding integrity during interim conditions. In principle, all spent fuel in the wet pools has sufficient hydrogen content for DHC to operate below 300°C. It is therefore of importance to establish the critical parameters for DHC to operate. This work studies the threshold stress intensity factor (KIH to initiate DHC as a function of temperature in Zry-4 for temperatures between 227°C and 315°C. The experimental technique used in this study was the pin-loading testing technique. To determine the KIH, an unloading method was used where the load was successively reduced in a stepwise manner until no cracking was observed during 24 hours. The results showed that there was moderate temperature behavior at lower temperatures. Around 300°C, there was a sharp increase in KIH indicating the upper temperature limit for DHC. The value for KIH at 227°C was determined to be 2.6 ± 0.3 MPa √m.

  16. A dual model HU conversion from MRI intensity values within and outside of bone segment for MRI-based radiotherapy treatment planning of prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Korhonen, Juha, E-mail: juha.p.korhonen@hus.fi [Clinical Research Institute Helsinki University Central Hospital Ltd., POB-700, 00029 HUS, Finland and Department of Oncology, Helsinki University Central Hospital, POB-180, 00029 HUS (Finland); Kapanen, Mika [Clinical Research Institute Helsinki University Central Hospital Ltd., POB-700, 00029 HUS (Finland); Department of Oncology, Helsinki University Central Hospital, POB-180, 00029 HUS (Finland); Department of Medical Physics, Tampere University Hospital, POB-2000, 33521 Tampere (Finland); Keyriläinen, Jani; Seppälä, Tiina; Tenhunen, Mikko [Department of Oncology, Helsinki University Central Hospital, POB-180, 00029 HUS (Finland)

    2014-01-15

    Purpose: The lack of electron density information in magnetic resonance images (MRI) poses a major challenge for MRI-based radiotherapy treatment planning (RTP). In this study the authors convert MRI intensity values into Hounsfield units (HUs) in the male pelvis and thus enable accurate MRI-based RTP for prostate cancer patients with varying tissue anatomy and body fat contents. Methods: T{sub 1}/T{sub 2}*-weighted MRI intensity values and standard computed tomography (CT) image HUs in the male pelvis were analyzed using image data of 10 prostate cancer patients. The collected data were utilized to generate a dual model HU conversion technique from MRI intensity values of the single image set separately within and outside of contoured pelvic bones. Within the bone segment local MRI intensity values were converted to HUs by applying a second-order polynomial model. This model was tuned for each patient by two patient-specific adjustments: MR signal normalization to correct shifts in absolute intensity level and application of a cutoff value to accurately represent low density bony tissue HUs. For soft tissues, such as fat and muscle, located outside of the bone contours, a threshold-based segmentation method without requirements for any patient-specific adjustments was introduced to convert MRI intensity values into HUs. The dual model HU conversion technique was implemented by constructing pseudo-CT images for 10 other prostate cancer patients. The feasibility of these images for RTP was evaluated by comparing HUs in the generated pseudo-CT images with those in standard CT images, and by determining deviations in MRI-based dose distributions compared to those in CT images with 7-field intensity modulated radiation therapy (IMRT) with the anisotropic analytical algorithm and 360° volumetric-modulated arc therapy (VMAT) with the Voxel Monte Carlo algorithm. Results: The average HU differences between the constructed pseudo-CT images and standard CT images of each

  17. Academic stress and positive affect: Asian value and self-worth contingency as moderators among Chinese international students.

    Science.gov (United States)

    Liao, Kelly Yu-Hsin; Wei, Meifen

    2014-01-01

    The theoretical model proposed by Berry and colleagues (Berry, 1997; Berry, Kim, Minde, & Mok, 1987) highlights the importance of identifying moderators in the acculturation process. Accordingly, the current study examined the Asian cultural value of family recognition through achievement (FRTA) and contingency of self-worth on academic competence (CSW-AC) as moderators in the association between academic stress and positive affect among Chinese international students. A total of 370 Chinese international students completed online surveys. Results from a hierarchical regression indicated that while academic stress was negatively associated with positive affect, FRTA was positively associated with positive affect. In other words, those with high academic stress reported a lower level of positive affect. However, individuals who endorsed high levels of FRTA reported a higher level of positive affect. In addition, results also revealed a significant interaction between academic stress and CSW-AC on positive affect. Thus, the study's finding supported the moderator role of CSW-AC. Simple effect analyses were conducted to examine the significant interaction. The results showed that higher levels of CSW-AC strengthened the negative association between academic stress and positive affect but lower levels of CSW-AC did not. Future research directions and implications are discussed.

  18. Occupational stress and mental health among nurses in a medical intensive care unit of a general hospital in Bandar Abbas in 2013.

    Science.gov (United States)

    Tajvar, Abdolhamid; Saraji, Gebraeil Nasl; Ghanbarnejad, Amin; Omidi, Leila; Hosseini, Seyed Sodabeh Seyed; Abadi, Ali Salehi Sahl

    2015-07-01

    Many nurses have reported experiencing high levels of occupational stress in their work environment. Stress, as an outcome of stressful workplaces and tasks, affects nursing behavior in hospital wards. The objectives of this research were to determine the prevalence of occupational stress and mental health problems in nurses in the intensive care unit (ICU) at Shahid Mohammadi Hospital in Bandar Abbas in 2013 and to determine the relationship between occupational stress and mental health. This cross-sectional study was conducted in 2013 on all of the nurses working in ICU at Shahid Mohammadi Hospital located in Bandar Abbas, Iran. Seventy-two nurses were selected as the population for this study, and all of them were female. Two questionnaires were used in this study, i.e., General Health Questionnaire-28 (GHQ-28) for assessing mental health and an occupational stress test for assessing job stress. Furthermore, the relationship between occupational stress and mental health was examined. One-way analysis of variance (ANOVA), independent samples t-test, and Pearson's product-moment correlation test were used to analyze the data. High and moderate levels of occupational stress were experienced by 83.9% and 10.7% of ICU nurses, respectively. The prevalence of mental disorders, somatic symptoms, anxiety, social dysfunction, and depression were 58.9, 60.7, 62.5, 71.4, and 10.7%, respectively. The findings of the independent samples t-test showed that somatic symptoms had significant relationships with age and working experience (p = 0.01). According to the independent samples t-test, there were no significant differences between somatic symptoms and working different shifts (p > 0.05). There was a high prevalence of occupational stress among ICU nurses. There was a significant relationship between occupational stress and mental health. Future interventions are needed to codify a comprehensive health program in this field to reduce occupational stress and enhance nurses

  19. Determining the Threshold Value of Basil Yield Reduction and Evaluation of Water Uptake Models under Salinity Stress Condition

    OpenAIRE

    M. Sarai Tabrizi; H. Babazadeh; M. Homaee; F. Kaveh Kaveh; M. Parsinejad

    2016-01-01

    Introduction: Several mathematical models are being used for assessing the plant response to the salinity of the root zone. The salinity of the soil and water resources is a major challenge for agricultural sector in Iran. Several mathematical models have been developed for plant responses to the salinity stress. However, these models are often applicable in particular conditions. The objectives of this study were to evaluate the threshold value of Basil yield reduction, modeling Basil respon...

  20. A mixed methods inquiry: How dairy farmers perceive the value(s) of their involvement in an intensive dairy herd health management program.

    Science.gov (United States)

    Kristensen, Erling; Enevoldsen, Carsten

    2008-12-18

    Research has been scarce when it comes to the motivational and behavioral sides of farmers' expectations related to dairy herd health management programs. The objectives of this study were to explore farmers' expectations related to participation in a health management program by: 1) identifying important ambitions, goals and subjective well-being among farmers, 2) submitting those data to a quantitative analysis thereby characterizing perspective(s) of value added by health management programs among farmers; and 3) to characterize perceptions of farmers' goals among veterinarians. The subject was initially explored by means of literature, interviews and discussions with farmers, herd health management consultants and researchers to provide an understanding (a concourse) of the research entity. The concourse was then broken down into 46 statements. Sixteen Danish dairy farmers and 18 veterinarians associated with one large nationwide veterinary practice were asked to rank the 46 statements that defined the concourse. Next, a principal component analysis was applied to identify correlated statements and thus families of perspectives between respondents. Q-methodology was utilized to represent each of the statements by one row and each respondent by one column in the matrix. A subset of the farmers participated in a series of semi-structured interviews to face validate the concourse and to discuss subjects like animal welfare, veterinarians' competences as experienced by the farmers and time constraints in the farmers' everyday life. Farmers' views could be described by four families of perspectives: Teamwork, Animal welfare, Knowledge dissemination, and Production. Veterinarians believed that farmers' primary focus was on production and profit, however, farmers' valued teamwork and animal welfare more. The veterinarians in this study appear to focus too much on financial performance and increased production when compared to most of the participating farmers

  1. A mixed methods inquiry: How dairy farmers perceive the value(s of their involvement in an intensive dairy herd health management program

    Directory of Open Access Journals (Sweden)

    Kristensen Erling

    2008-12-01

    Full Text Available Abstract Background Research has been scarce when it comes to the motivational and behavioral sides of farmers' expectations related to dairy herd health management programs. The objectives of this study were to explore farmers' expectations related to participation in a health management program by: 1 identifying important ambitions, goals and subjective well-being among farmers, 2 submitting those data to a quantitative analysis thereby characterizing perspective(s of value added by health management programs among farmers; and 3 to characterize perceptions of farmers' goals among veterinarians. Methods The subject was initially explored by means of literature, interviews and discussions with farmers, herd health management consultants and researchers to provide an understanding (a concourse of the research entity. The concourse was then broken down into 46 statements. Sixteen Danish dairy farmers and 18 veterinarians associated with one large nationwide veterinary practice were asked to rank the 46 statements that defined the concourse. Next, a principal component analysis was applied to identify correlated statements and thus families of perspectives between respondents. Q-methodology was utilized to represent each of the statements by one row and each respondent by one column in the matrix. A subset of the farmers participated in a series of semi-structured interviews to face validate the concourse and to discuss subjects like animal welfare, veterinarians' competences as experienced by the farmers and time constraints in the farmers' everyday life. Results Farmers' views could be described by four families of perspectives: Teamwork, Animal welfare, Knowledge dissemination, and Production. Veterinarians believed that farmers' primary focus was on production and profit, however, farmers' valued teamwork and animal welfare more. Conclusion The veterinarians in this study appear to focus too much on financial performance and increased

  2. Innovation Value of Information Technology: Impact of Information Technology--Intensity on Innovation Capability and Firm Performance

    Science.gov (United States)

    Ramamani, Mahesh Kumar

    2010-01-01

    Though information technology adoptions have been always referred to as innovations in firms, much of the business value literature has concentrated on the tangible and immediately measurable impacts of information technology (IT) adoptions. This study aims to explore the impact of information technology investments on the innovativeness of a…

  3. The clinical value of daily routine chest radiographs in a mixed medical-surgical intensive care unit is low

    NARCIS (Netherlands)

    Graat, Marleen E.; Choi, Goda; Wolthuis, Esther K.; Korevaar, Johanna C.; Spronk, Peter E.; Stoker, Jaap; Vroom, Margreeth B.; Schultz, Marcus J.

    2006-01-01

    INTRODUCTION: The clinical value of daily routine chest radiographs (CXRs) in critically ill patients is unknown. We conducted this study to evaluate how frequently unexpected predefined major abnormalities are identified with daily routine CXRs, and how often these findings lead to a change in care

  4. Arterial waveform-analysis is of limited value in daily clinical practice in the intensive care unit

    DEFF Research Database (Denmark)

    Henningsen, Louise; Haase, Nicolai; Pedersen, Ulf Gøttrup

    2015-01-01

    the proportion of intensive care unit (ICU) patients with shock who at the time of resuscitation fulfilled the prerequisites for using the arterial waveform-derived variables. METHODS: This was a prospective cohort study performed at six ICUs. The study included consecutive adult patients with shock (20 patients...... per ICU) who received fluid resuscitation on the first day of shock. The fulfilment or not of the prerequisites (sedation, sinus rhythm and controlled ventilation with tidal volumes > 7 ml/kg) was registered at the time of the first fluid resuscitation episode and at fluid resuscitation episodes......% CI: 46-65) were on controlled ventilation and 50% (95% CI: 39-61) received tidal volumes of more than 7 ml/kg. Only 23% (95% CI: 14-33) of the patients fulfilled all four prerequisites. CONCLUSIONS: Less than a quarter of the ICU patients with shock fulfilled all the prerequisites for the use...

  5. Tamarix arborea var. arborea and Tamarix parviflora: Two species valued for their adaptability to stress conditions.

    Science.gov (United States)

    Grisafi, Francesca; Oddo, Elisabetta; Gargano, Maria Letizia; Inzerillo, Simone; Russo, Gianni; Venturella, Giuseppe

    2016-03-01

    The choice of stress resistant and highly adaptable species is a fundamental step for landscaping and ornamental purposes in arid and coastal environments such as those in the Mediterranean basin. The genus Tamarix L. includes about 90 species with a high endurance of adversity. We investigated the water relations and photosynthetic response of Tamarix arborea (Sieb. ex Ehrenb.) Bge. var. arborea and T. parviflora DC. growing in an urban environment. Both species showed no evidence of drought or salt stress in summer, and appeared to follow two strategies with T. arborea var. arborea investing in high carbon gain at the beginning of the summer, and then reducing photosynthetic activity at the end of the season, and T. parviflora showing lower but constant levels of photosynthetic activity throughout the vegetative season. For landscaping and ornamental purposes, we suggest T. arborea var. arborea when a fast-growing, high-cover species is necessary, and T. parviflora when less-invasive species are required.

  6. Incidence and Risk Factors for Intensive Care Unit–related Post-traumatic Stress Disorder in Veterans and Civilians

    Science.gov (United States)

    Jackson, James C.; Morandi, Alessandro; Girard, Timothy D.; Hughes, Christopher G.; Thompson, Jennifer L.; Kiehl, Amy L.; Elstad, Mark R.; Wasserstein, Mitzi L.; Goodman, Richard B.; Beckham, Jean C.; Chandrasekhar, Rameela; Dittus, Robert S.; Ely, E. Wesley; Pandharipande, Pratik P.

    2016-01-01

    Rationale: The incidence and risk factors of post-traumatic stress disorder (PTSD) related to the intensive care unit (ICU) experience have not been reported in a mixed veteran and civilian cohort. Objectives: To describe the incidence and risk factors for ICU-related PTSD in veterans and civilians. Methods: This is a prospective, observational, multicenter cohort enrolling adult survivors of critical illness after respiratory failure and/or shock from three Veterans Affairs and one civilian hospital. After classifying those with/without preexisting PTSD (i.e., PTSD before hospitalization), we then assessed all subjects for ICU-related PTSD at 3 and 12 months post hospitalization. Measurements and Main Results: Of 255 survivors, 181 and 160 subjects were assessed for ICU-related PTSD at 3- and 12-month follow-up, respectively. A high probability of ICU-related PTSD was found in up to 10% of patients at either follow-up time point, whether assessed by PTSD Checklist Event-Specific Version (score ≥ 50) or item mapping using the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV). In the multivariable regression, preexisting PTSD was independently associated with ICU-related PTSD at both 3 and 12 months (P < 0.001), as was preexisting depression (P < 0.03), but veteran status was not a consistent independent risk factor for ICU-related PTSD (3-month P = 0.01, 12-month P = 0.48). Conclusions: This study found around 1 in 10 ICU survivors experienced ICU-related PTSD (i.e., PTSD anchored to their critical illness) in the year after hospitalization. Preexisting PTSD and depression were strongly associated with ICU-related PTSD. PMID:26735627

  7. Arterial waveform-analysis is of limited value in daily clinical practice in the intensive care unit

    DEFF Research Database (Denmark)

    Hennings, Louise Inkeri; Haase, Nicolai; Pedersen, Ulf Gøttrup

    2015-01-01

    INTRODUCTION: It is difficult to identify the patients who will respond to fluid therapy, but the arterial waveform-derived variables have reasonably predictive values for fluid responsiveness. However, the patient must fulfil a number of prerequisites for these variables to be valid. We assessed...... of arterial waveform-derived variables to predict fluid responsiveness. Thus, these variables may be of limited use during resuscitation in the ICU. FUNDING: none. TRIAL REGISTRATION: not relevant....

  8. A database for analysis of speech under physical stress: detection of exercise intensity while running and talking

    NARCIS (Netherlands)

    Truong, Khiet Phuong; Nieuwenhuys, Arne; Beek, Peter; Evers, Vanessa

    One of the ways to gauge your own exercise intensity while running, is to assess your capability of talking while running: if you can still speak comfortably, you are running within the recommended intensity guidelines. This subjective way of estimating one's exercise intensity by talking (i.e. the

  9. Effect of the low- versus high-intensity exercise training on endoplasmic reticulum stress and GLP-1 in adolescents with type 2 diabetes mellitus.

    Science.gov (United States)

    Lee, Sung Soo; Yoo, Jae Ho; So, Yong Seok

    2015-10-01

    [Purpose] The primary objective of this study was to investigate the effect of low-intensity exercise training compare with high-intensity exercise training on endoplasmic reticulum stress and glucagon-like peptide-1 in adolescents with type 2 diabetes mellitus. [Subjects and Methods] The low-intensity exercise training group performed aerobic exercise training at an intensity of ≤ 45% of the heart rate reserve. The high-intensity interval exercise training group performed interval exercise training at an intensity of ≥ 80% of the heart rate reserve. The exercise-related energy consumption was determined for both groups on a per-week basis (1,200 kcal/week). [Results] Both groups showed improvement in the glucose-regulated protein 78 and dipeptidyl peptidase-4, but the size of the between-group effect was not statistically significant. The high-intensity interval exercise training group showed a significant reduction in percentage body fat. The C-peptide level increased after the 12-weeks programs and was significantly different, between the groups. Fasting glucose, insulin resistance in the fasting state according to homeostasis model assessment, and leptin decreased after the 12-weeks exercise program and were significantly different between the groups, and glucagon-like peptide-1 increased after the 12-week exercise programs and was significantly different between the groups. [Conclusion] In conclusion high-intensity interval exercise training, as defined in this study, may lead to improvements in body composition, glycemic control, endoplasmic reticulum stress, and the glucagon-like peptide-1 in adolescents with type 2 diabetes mellitus.

  10. Mixed-mode stress intensity factors for kink cracks with finite kink length loaded in tension and bending: application to dentin and enamel.

    Science.gov (United States)

    Bechtle, Sabine; Fett, Theo; Rizzi, Gabriele; Habelitz, Stefan; Schneider, Gerold A

    2010-05-01

    Fracture toughness resistance curves describe a material's resistance against crack propagation. These curves are often used to characterize biomaterials like bone, nacre or dentin as these materials commonly exhibit a pronounced increase in fracture toughness with crack extension due to co-acting mechanisms such as crack bridging, crack deflection and microcracking. The knowledge of appropriate stress intensity factors which depend on the sample and crack geometry is essential for determining these curves. For the dental biomaterials enamel and dentin it was observed that, under bending and tensile loading, crack propagation occurs under certain constant angles to the initial notch direction during testing procedures used for fracture resistance curve determination. For this special crack geometry (a kink crack of finite length in a finite body) appropriate geometric function solutions are missing. Hence, we present in this study new mixed-mode stress intensity factors for kink cracks with finite kink length within samples of finite dimensions for two loading cases (tension and bending) which were derived from a combination of mixed-mode stress intensity factors of kink cracks with infinitely small kinks and of slant cracks. These results were further applied to determine the fracture resistance curves of enamel and dentin by testing single edge notched bending (SENB) specimens. It was found that kink cracks with finite kink length exhibit identical stress fields to slant cracks as soon as the kink length exceeds 0.15 times the initial straight crack or notch length. The use of stress intensity factor solutions for infinitely small kink cracks for the determination of dentin fracture resistance curves (as was done by other researchers) leads to an overestimation of dentin's fracture resistance of up to 30%. Copyright 2010 Elsevier Ltd. All rights reserved.

  11. Value of MRI in the diagnosis of stress urinary incontinence in the absence of organ descent

    International Nuclear Information System (INIS)

    Beyersdorff, D.; Taupitz, M.; Fischer, T.; Hamm, B.; Tunn, R.; Rieprich, M.

    2001-01-01

    To detect pathomorphological changes of the pelvic floor, the vagina, and the urethra by MR imaging in patients with stress urinary incontinence in the absence of organ descent compared with findings in 10 healthy controls. Materials and Methods: The study included 10 healthy controls and 38 patients with stage II urinary incontinence showing no urge symptoms but a pathological stress profile on urodynamic testing. The subjects underwent MR imaging with a phased-array coil at 1.5 T in addition to urodynamic testing and gynecological examination. The following sequences were used: axial and coronal PD-weighted TSE sequences with a FOV of 20 cm and a section thickness of 4 mm; axial STIR sequence. Sagittal T 2 -weighted HASTE sequences were acquired during pelvic floor contraction, relaxation, and straining maneuvers. Results: In 22/38 cases pathomorphological changes were found by MR imaging. The pathomorphological changes were classified as lateral defects (n = 14) if the musculofascial connection between the levator muscle and the lateral vaginal wall or the butterfly shape of the vagina was absent and as central (n = 16) if changes were detected in the urethral wall. Defects of the pelvic floor muscles were detected in 8 cases. No underlying changes were identified in 16/38 cases. Conclusion: In cases of female urinary incontinence, MR imaging of the pelvic floor can detect pathomorphological changes, which are difficult to identify by clinical examination. MR imaging currently does not allow the detection of morphological changes in all forms of female urinary stress incontinence. (orig.) [de

  12. The value of β-blockers administration during recovery phase of dobutamine stress echocardiography: a review.

    Science.gov (United States)

    Nguyen, James; Juneman, Elizabeth; Movahed, Mohammad Reza

    2013-07-01

    Dobutamine stress echocardiography (DSE) is a successful technique for detection of ischemia in patients with suspected coronary artery disease (CAD). There are some data that administration of β-blocker after peak infusion of dobutamine can improve sensitivity. The goal of this manuscript is to review the current literature in regard to the mechanism and accuracy of post-dobutamine β-blocker administration for ischemia detection. In this review, we present 2 case reports followed by detailed review of the literature. © 2013. This article is a U.S. Government work and is in the public domain in the USA.

  13. The value of urethro-cystography in the diagnosis of female urinary stress incontinence

    International Nuclear Information System (INIS)

    Goeller, W.; Koeller, M.; Tremmel, K.; Barth, V.; Staedtische Krankenanstalten Esslingen am Neckar

    1986-01-01

    Urethrocystography was performed in 72 women with stress urinary incontinence (SUI). The radiological findings were compared with the clinical diagnosis. 8 Patients with a normal radiological study had SUI grade I by clinical criteria. Explanations of this discrepancy are discussed. In 4 cases the interpretation interfered with a large cystocele. In 60 patients (83.5%) the radiological study confirmed the clinical diagnosis and supported the gynaecologist in the indication for operation on SUI. However this indication cannot be based on the radiological study by itself; it must in fact take into account all the other aspects of the disease. (orig.)

  14. Value added phytoremediation of metal stressed soils using phosphate solubilizing microbial consortium.

    Science.gov (United States)

    Gupta, Pratishtha; Kumar, Vipin

    2017-01-01

    The presence of heavy metals in the soil is a matter of growing concern due to their toxic and non-biodegradable nature. Lack of effectiveness of various conventional methods due to economic and technical constraints resulted in the search for an eco-friendly and cost-effective biological techniques for heavy metal removal from the environment. Until now, phytoremediation has emerged as an innovative technique to address the problem. However, the efficiency of phytoremediation process is hindered under the high metal concentration conditions. Hence, phosphate solubilizing microbes (PSM) assisted phytoremediation technique is gaining more insight as it can reduce the contamination load even under elevated metal stressed conditions. These microbes convert heavy metals into soluble and bioavailable forms, which consequently facilitate phytoremediation. Several studies have reported that the use of microbial consortium for remediation is considered more effective as compared to single strain pure culture. Therefore, this review paper focuses on the current trends in research related to PSM mediated uptake of heavy metal by plants. The efficiency of PSM consortia in enhancing the phytoremediation process has also been reviewed. Moreover, the role of phosphatase enzymes in the mineralization of organic forms of phosphate in soil is further discussed. Biosurfactant mediated bioremediation of metal polluted soils is a matter of extensive research nowadays. Hence, the recent advancement of using biosurfactants in enhanced phytoremediation of metal stressed soils is also described.

  15. Predictive value of myocardial perfusion scintigraphy after stress in patients without previous myocardial infarction

    International Nuclear Information System (INIS)

    Tuner, D.A.; Battle, W.E.; Deshmukh, H.; Colandrea, M.A.; Snyder, G.J.; Fordham, E.W.; Messer, J.V.

    1978-01-01

    Seventy-five patients who had chest pain but no history or ECG evidence of myocardial infarction (MI) underwent myocardial-stress perfusion scintigraphy (MSPS) with thallium-201, treadmill-stress testing (TST), and coronary cineangiography (CA). The sensitivities of MSPS and TST for coronary stenosis greater than or equal to 75 percent were 68 percent and 71 percent, respectively; their specificities were 97 percent and 79 percent, respectively (0.1 greater than p greater than 0.05). When the character of a patient's chest pain is considered, Bayesian analysis leads to the following conclusions: MSPS can be useful in pre-CA screening of patients with chest pain but no MI if their pain is thought to be of uncertain or nonischemic origin; the sensitivity of Tl-201 MSPS is not sufficient for pre-CA screening of patients without MI who have typical or atypical angina pectoris; the sensitivity of MSPS would have to be approximately 95 percent in order for the test to be useful in pre-CA screening of patients who have atypical angina pectoris; MSPS may be superior to TST in these applications; and it is not clear that there is any advantage in combining MSPS and TST into a single screening test rather than using MSPS alone

  16. Microalgae for high-value compounds and biofuels production: a review with focus on cultivation under stress conditions.

    Science.gov (United States)

    Markou, Giorgos; Nerantzis, Elias

    2013-12-01

    Microalgal biomass as feedstock for biofuel production is an attracting alternative to terrestrial plant utilization for biofuels production. However, today the microalgal cultivation systems for energy production purposes seem not yet to be economically feasible. Microalgae, though cultivated under stress conditions, such as nutrient starvation, high salinity, high temperature etc. accumulate considerable amounts (up to 60-65% of dry weight) of lipids or carbohydrates along with several secondary metabolites. Especially some of the latter are valuable compounds with an enormous range of industrial applications. The simultaneous production of lipids or carbohydrates for biofuel production and of secondary metabolites in a biorefinery concept might allow the microalgal production to be economically feasible. This paper aims to provide a review on the available literature about the cultivation of microalgae for the accumulation of high-value compounds along with lipids or carbohydrates focusing on stress cultivation conditions. © 2013.

  17. Additional diagnostic value of systolic dysfunction induced by dipyridamole stress cardiac magnetic resonance used in detecting coronary artery disease.

    Science.gov (United States)

    Husser, Oliver; Bodí, Vicente; Sanchís, Juan; Mainar, Luis; Núñez, Julio; López-Lereu, María P; Monmeneu, José V; Ruiz, Vicente; Rumiz, Eva; Moratal, David; Chorro, Francisco J; Llácer, Angel

    2009-04-01

    Dipyridamole stress perfusion cardiovascular magnetic resonance (CMR) is used to detect coronary artery disease (CAD). However, few data are available on the diagnostic value of the systolic dysfunction induced by dipyridamole. This study investigated whether the induction of systolic dysfunction supplements the diagnostic information provided by perfusion imaging in the detection of CAD. Overall, 166 patients underwent dipyridamole CMR and quantitative coronary angiography, with CAD being defined as a stenosis > or =70%. Systolic dysfunction at rest, systolic dysfunction with dipyridamole, induced systolic dysfunction, and stress first-pass perfussion deficit (PD) and delayed enhancement were quantified. In the multivariate analysis, PD (hazard ratio [HR]=1.6; 95% confidence interval [CI], 1.33-1.91;Pstatistic for predicting CAD (0.81 vs. 0.87; P=.02). Combining induced systolic dysfunction with perfusion imaging increases the diagnostic accuracy of detecting CAD and enables patients with severe ischemia and a high probability of CAD to be identified.

  18. Value Retention, Service Life, Use Intensity and Long-Term Productivity of Wood Chippers as Obtained from Contractor Records

    Directory of Open Access Journals (Sweden)

    Raffaele Spinelli

    2017-12-01

    Full Text Available Acknowledging the absence of up-to-date empirical data on the value retention, service life and annual use of chipping machinery, in 2017 the authors surveyed the records kept by 50 contractors offering biomass chipping services. The machine fleet and operations in this survey could be taken as representative for most of Europe, where the biomass sector is well established and is facing further expansion. Data collection included the whole chipping unit, comprised of chipper, carrier and loader. Manually-fed units were excluded from the survey. The data pointed at a service life up to and exceeding 10,000 h and 10 years, which relieved any concerns about poor durability. Value retention was good, and may exceed that of other mainstream forestry equipment. Engine power was the main explanatory variable in any models to predict purchase price and productivity. The effect of this variable could explain most of the variability (>80% in the purchase price and productivity data. Results also pointed at the essential equivalence in price and productivity between PTO-driven (i.e., tractor powered and independent-engine chippers, once differences in engine power are accounted for. However, the distribution of purchase price between different components of the chipping unit was different between the two unit types, with the chipper accounting for a larger proportion of the total investment in independent-engine units. Machine power was also different, with most PTO-driven units being significantly smaller than independent-engine units, due to the limitations of existing tractors. Furthermore, half of the carriers assigned to a PTO-driven unit were subject to flexible use, i.e., they were not solely used for chipping work.

  19. Theoretical calculations of L alpha one x-ray emission intensity ratios for uranium in various matrices: a comparison with experimental values

    International Nuclear Information System (INIS)

    Anderson, L.D.

    1976-01-01

    The U L/sub α1/ x-ray emission intensity ratios (I/sub lambda/sub L//I sub lambda/sub L/, sub 100 percent/sub UO 2 /) in various matrices were calculated using the fundamental parameters formula of Criss and Birks and mass absorption coefficients calculated from a formula developed by Dewey. The use of the intensity ratio made it unnecessary to know the fluorescence yield for the U L/sub III/ level, the probability of emission of the U L/sub α1/ line, and the jump ratios for the three absorption edges of uranium. Also, since an intensity ratio was used, the results are independent of the x-ray tube current and the spectral distribution of the x-ray tube. A method is presented to calculate the intensity ratios for x-ray tube voltages other than the value (45 kV) used in the calculations. The theoretical results are calculated and compared with the experimental results obtained for 141 matrices. Difficulties due to oxidation of some of the metal powders used in the sample preparation, to small concentrations of uranium, and to an excessively large number of elements present in some of the samples resulted in the invalidation of the experimental results for 91 of the matrices. For the remaining 50 matrices, the theoretical and experimental values agreed to within +-5 percent relative error for 36 matrices; to within +-5 percent to +- 10 percent for 7 matrices; to within +-10 percent to +-20 percent for 6 matrices; and was greater than +-20 percent for 1 matrix

  20. Project of integrity assessment of flawed components with structural discontinuity (IAF). Data book for estimation stress intensity factor. Surface crack on ICM housing for penetration in reactor vessel

    International Nuclear Information System (INIS)

    2012-12-01

    The project of Integrity Assessment of Flawed Components with Structural Discontinuity (IAF) was entrusted to Japan Power Engineering and Inspection Corporation (JAPEIC) from Nuclear and Industrial Safety Agency (NISA) and started from FY 2001. And then, it was taken over to Japan Nuclear Energy Safety Organization (JNES) which was established in October 2003 and carried out until FY 2007. In the IAF project, weld joints between nickel based alloys and low alloy steels around penetrations in reactor vessel, safe-end of nozzles and shroud supports were selected from among components and pipe arrangements in nuclear power plants, where high residual stresses were generated due to welding and complex structure. Residual stresses around of the weld joints were estimated by finite element analysis method (FEM) with a general modeling method, then the reasonability and the conservativeness was evaluated. In addition, for postulated surface crack of stress corrosion cracking (SCC), a simple calculation method of stress intensity factor (K) required to estimate the crack growth was proposed and the effectiveness was confirmed. JNES compiled results of the IAF project into Data Books of Residual Stress Analysis of Weld Joint, and Data Book of Simplified Stress Intensity Factor Calculation for Penetration of Reactor as typical Structure Discontinuity, respectively. Data Books of Residual Stress Analysis in Weld Joint. 1. Butt Weld Joint of Small Diameter Cylinder (4B Sch40) (JNES-RE-2012-0005), 2. Dissimilar Metal Weld Joint in Safe End (One-Side Groove Joint (JNES-RE-2012-0006), 3. Dissimilar Metal Weld Joint in Safe End (Large Diameter Both-Side Groove Joint) (JNES-RE-2012-0007), 4. Weld Joint around Penetrations in Reactor Vessel (Insert Joint) (JNES-RE-2012-0008), 5. Weld Joint in Shroud Support (H8, H9, H10 and H11 Welds) (JNES-RE-2012-0009), 6. Analysis Model of Dissimilar Metal Weld Joint Applied Post Weld Heat Treatment (PWHT) (JNES-RE-2012-0010). Data Book of

  1. Development of stress ulcers assessed by gastric electrical potential difference, pH of gastric juice, and endoscopy in patients in the intensive care unit

    DEFF Research Database (Denmark)

    Rubinstein, E; Gjørup, I; Schulze, S

    1992-01-01

    OBJECTIVE: To assess measurement of gastric electrical potential difference, pH of gastric mucosa, and endoscopic findings in patients in intensive care units who are at risk of developing stress ulcers. DESIGN: Open comparison with age- and sex-matched control subjects. SETTING: Herlev Hospital......, Denmark. SUBJECTS: Sixteen consecutive patients with no history of gastrointestinal haemorrhage, coagulopathy, or ulcer disease who had been admitted to the intensive care unit, and 16 age- and sex-matched outpatients with normal endoscopic findings. INTERVENTIONS: Upper gastrointestinal endoscopy, during...... which any lesions that were found were scored according to severity, the gastric potential difference, and the pH of gastric juice were measured. OUTCOME MEASURES: Correlation between the incidence of stress ulceration found at endoscopy, gastric potential difference, and gastric pH. RESULTS: Gastric...

  2. Predictive value of urodynamics on outcome after midurethral sling surgery for female stress urinary incontinence

    NARCIS (Netherlands)

    Houwert, R. Marijn; Venema, Pieter L.; Aquarius, Annelies E.; Bruinse, Hein W.; Kil, Paul J. M.; Vervest, Harry A. M.

    OBJECTIVE: The aim of this study was to evaluate the value of urodynamic investigation in the preoperative workup of midurethral sling surgery and to identify risk factors for failure after 3 different midurethral sling procedures. STUDY DESIGN: Retrospective cohort study. 437 women who underwent a

  3. Scintigraphic assessment of normal values of lower limb perfusion under stress and rest, with possible clinical applications

    International Nuclear Information System (INIS)

    Malkowski, B.; Zajac, A.; Maziarz, Z.; Zaborowski, G.; Ryglewska-Brzozowska, M.; Malara, A.; Tryniszewski, W.

    2005-01-01

    The lack of a range of normal values of perfusion in the lower limbs during stress and at rest narrows the use of this type of diagnostic tool to the estimation of the current state of relative perfusion without indications of the presence or level of perfusion disturbances. Numerous reports on early changes in endothelium reactivity (depending on disease and degree of vessel pathology) encouraged us to assess lower limb perfusion in healthy people. Our goal was to 1) work out a program and method which would enable lower limb perfusion assessment under stress and at rest in patients without signs of lower limb circulation deprivation and 2) establish the normal range of indexes of lower limb perfusion under stress and at rest which would enable their use in the diagnostics of lower limb muscle circulation. 33 male patients aged between 25 to 45 years (mean: 35.30 ± 6.04) without signs of circulatory problems were entered into the study. To exclude circulatory disturbances, Doppler USG, blood pressure, and laboratory tests were performed on every patient at rest 5 min. after the injection of 11.1 MBq/kg 99 mTc MIBI. Whole body as well as thigh and calf scintigrams were made with an ELSCINT SP6HR gamma-camera. The symmetry of the thigh and calf perfusion (WSU, WSP) and the indexes of the thigh (WPLU, WPPU) and calf (WPLP, WSPP) perfusion of both lower limbs were estimated. At rest: WSP: 96.47% ±1.02, WSP: 96.47% ± 1.02, WPLP: 9.77 ± 0.32, WPPP: 9.78 ± 0.31, WPLU: 8.45 ± 0.22, WPPU: 8.48 ± 0.22. Under stress: WSP: 96.69% ± 1.32, WSU: 96.41% ± 1.20, WPLP: 8.78 ± 0.26, WPPP: 8.81 ± 0.25, WPLU: 7.77 ± 0.25, WPPU: 7.82 ± 0.26. Anamnesis, additional studies, and laboratory tests in the group examined did not show any circulatory disturbances. The estimated values in patients without circulatory disturbances are similar and within a narrow range, which allows us to calculate the norms of lower limb perfusion at rest and under stress. The determined normal

  4. Bell's palsy: what is the prognostic value of measurements of signal intensity increases with contrast enhancement on MRI?

    International Nuclear Information System (INIS)

    Kress, B.P.J.; Efinger, K.; Solbach, T.; Gottschalk, A.; Baehren, W.; Griesbeck, F.; Kornhuber, A.W.

    2002-01-01

    Our objective was to assess the prognostic value of measurements of the degree of contrast enhancement of the intratemporal segments of the facial nerve. We prospectively obtained MRI, slice thickness <1 mm of 20 patients with a facial palsy on the first day of inpatient treatment, and measured contrast enhancement of the nerve. The data were compared with compound muscle action potential (CMAP) measurements and the clinical course. Analysis of the initial enabled differentiation of three patients whose palsy was to show no improvement from 17 whose palsy was to resolve as expected. No patient with a poor outcome showed lesser increase in signal in the internal auditory canal, pars tympanica and pars mastoidea than patients who fully recovered. In no patient who had been diagnosed on the basis of the initial MRI as having a ''normal'' palsy was the amplitude of the (CMAP) reduced to less than 20% that of the normal side. Measurement of contrast enhancement was thus shown to be a prognostic indicator and may provide a basis for a differential treatment of facial palsy. (orig.)

  5. Investigation of the Stress Intensity Limits of ASME Section III Div.5 for Structure Design Criteria of SFR Fuel Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Choo, Jin-Yup; Kim, Hyung-Kyu; Cheon, Jin-Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    These affect the mechanical design of the fuel assembly components. And thus, appropriate structural design criteria should also be chosen to incorporate the specific design conditions of the SFR fuel assemblies. Among them, the temperature is one of the most crucial conditions to be concerned because the sodium coolant temperature is normally more than 500ºC which is much higher than that of the LWR (< 350ºC). This implies that a thermal creep should be significantly considered in the SFR fuel assembly mechanical design. In addition to the high temperature condition, an irradiation swelling is also an important behavior that the SFR fuel assembly material should accommodate. To incorporate the temperature and irradiation impacts, the material of the fuel assembly components is presently determined to be made of HT-9, the ferriticmartensitic steel. In this paper, the ASME Sec. III Div. 5 (referred to as ‘Div. 5’ hereinafter), which was developed for a ‘high temperature reactor’, is considered as one of the structural design criteria for the mechanical design of SFR fuel assemblies. In this paper, the stress intensity limits, S{sub m} and S{sub t} of HT-9 were built for the structural criteria of an SFR fuel assembly. S{sub m} is obtained from the ultimate strength. As for S{sub t}, it is more complicated because of its dependency of time duration in addition to temperature. Following the definition of S{sub mt}, the method in the ASME Sec. III Div. 1, Subsec. NH was consulted. We found that the Sm is adopted as S{sub mt} under the temperature about 470ºC which is relatively low temperature range and over 470ºC with relatively short time duration as 1000 hours. And the S{sub t} is adopted as Smt at over 470ºC and long time duration over 34800 hours, and over 520ºC and 10{sup 4} hours too. And at over 570ºC and 1000 hours, and at over 630ºC and 100 hours, S{sub t} is also adopted for S{sub mt}.

  6. Comparison of standardized uptake values measured on 18F-NaF PET/CT scans using three different tube current intensities

    OpenAIRE

    Agnes Araujo Valadares; Paulo Schiavom Duarte; Eduardo Bechtloff Woellner; George Barberio Coura-Filho; Marcelo Tatit Sapienza; Carlos Alberto Buchpiguel

    2015-01-01

    Objective: To analyze standardized uptake values (SUVs) using three different tube current intensities for attenuation correction on 18FNaF PET/CT scans. Materials and Methods: A total of 254 18F-NaF PET/CT studies were analyzed using 10, 20 and 30 mAs. The SUVs were calculated in volumes of interest (VOIs) drawn on three skeletal regions, namely, right proximal humeral diaphysis (RH), right proximal femoral diaphysis (RF), and first lumbar vertebra (LV1) in a total of 712 VOIs. The analyses ...

  7. Increased signal intensity of prostate lesions on high b-value diffusion-weighted images as a predictive sign of malignancy

    International Nuclear Information System (INIS)

    Quentin, Michael; Schimmoeller, Lars; Antoch, Gerald; Blondin, Dirk; Arsov, Christian; Rabenalt, Robert; Albers, Peter

    2014-01-01

    The evaluation of lesions detected in prostate magnetic resonance imaging (MRI) with increased signal intensity (SI) on high b-value diffusion-weighted images as a sign of malignancy. One hundred and three consecutive patients with prostate MRI examination and MRI-guided in-bore biopsy were retrospectively included in the study. MRI-guided in-bore biopsy histologically confirmed prostate cancer in 50 patients (n = 92 lesions). The other 53 patients (n = 122 lesions) had negative bioptical results. In patients with histologically confirmed prostate cancer, 46 of the 92 lesions had visually increased SI on the high b-value images compared with the peripheral zone (SI = +27 ± 16%) or the central gland (SI = +37 ± 19%, P < 0.001 respectively). In patients with a negative biopsy, ten of the 122 lesions had visually increased SI (compared with the peripheral zone, SI = +29 ± 18%, and with the central gland, SI = +41 ± 15%, P < 0.001 respectively). Neither the apparent diffusion coefficient (ADC) values nor the Gleason Score of lesions with increased SI were significantly different from lesions without increased SI. Visually increased SI on the high b-value images of diffusion-weighted imaging using standard b-values is a sign of malignancy but can occasionally also be a feature of benign lesions. However, it does not indicate more aggressive tumours. (orig.)

  8. High- but not low-intensity light leads to oxidative stress and quality loss of cold-stored baby leaf spinach.

    Science.gov (United States)

    Glowacz, Marcin; Mogren, Lars M; Reade, John P H; Cobb, Andrew H; Monaghan, James M

    2015-07-01

    Quality management in the fresh produce industry is an important issue. Spinach is exposed to various adverse conditions (temperature, light, etc.) within the supply chain. The present experiments were conducted to investigate the effect of light conditions (dark, low-intensity light (LL) and high-intensity light (HL)) and photoperiod (6 h HL and 18 h dark) on the quality changes of cold-stored spinach. HL exposure resulted in oxidative stress, causing tissue damage and quality loss as evidenced by increased membrane damage and water loss. The content of total ascorbic acid was reduced under HL conditions. On the other hand, storage of spinach under LL conditions gave promising results, as nutritional quality was not reduced, while texture maintenance was improved. No significant differences, with the exception of nutritional quality, were found between spinach leaves stored under continuous (24 h) low-intensity light (30-35 µmol m(-2) s(-1)) and their counterparts stored under the same light integral over 6 h (130-140 µmol m(-2) s(-1)). LL extended the shelf-life of spinach. The amount of light received by the leaves was the key factor affecting produce quality. Light intensity, however, has to be low enough not to cause excess oxidative stress and lead to accelerated senescence. © 2014 Society of Chemical Industry.

  9. Effect of Chinese traditional medicine anti-fatigue prescription on the concentration of the serum testosterone and cortisol in male rats under stress of maximum intensive training

    International Nuclear Information System (INIS)

    Dong Ling; Si Xulan

    2008-01-01

    Objective: To study the effect of chinese traditional medicine anti-fatigue prescription on the concentration of the serum testosterone (T) and cortisol (C) in male rats under the stress of maximum intensive training. Methods: Wistar male rat models of stress under maximum intensity training were established (n=40) and half of them were treated with Chinese traditional medicine anti-fatigue prescription twenty undisturbed rats served as controls. Testosterone and cortisol serum levels were determined with RIA at the end of the seven weeks' experiment. Results: Maximum intensive training would cause the level of the serum testosterone lowered, the concentration of the cortisol elevated and the ratio of T/C reduced. The serum T levels and T/C ratio were significantly lower and cortisol levels significantly higher in the untreated models than those in the treated models and controls (P<0.01). The levels of the two hormones were markedly corrected in the treated models with no significantly differences from those in the controls. However, the T/C ratio was still significantly lower than that in the controls (P <0.05) due to a relatively slightly greater degree of reduction of T levels. Conclusion: Anti-fatigue prescription can not only promote the recovery of fatigue after the maximum intensive training but also strengthen the anabolism of the rats. (authors)

  10. Correlations of the glycemic variability with oxidative stress and erythrocytes membrane stability in patients with type 1 diabetes under intensive treatment.

    Science.gov (United States)

    Rodrigues, Ricardo; Alves de Medeiros, Luciana; Moreira Cunha, Lucas; da Silva Garrote-Filho, Mario; Bernardino Neto, Morun; Tannus Jorge, Paulo; Santos Resende, Elmiro; Penha-Silva, Nilson

    2018-02-07

    This study aimed to evaluate the correlations of glycemic variability with erythrocyte membrane stability parameters and oxidative stress markers in patients with DM1 under intensive treatment. 90 patients with DM1 and under intensive treatment of the disease were evaluated in relation to anthropometric indices, records of glycemic averages and parameters of glycemic variability, biochemical dosages (glucose, uric acid, lipidogram, glycated hemoglobin, microalbuminuria, creatinine and iron) reticulocyte count, erythrocyte membrane stability parameters and oxidative stress markers (thiobarbituric acid reactive substances, TBARS, and glutathione reductase, GR). Indicators of glycemic variability in the short and long term showed correlations with parameters of membrane stability and markers of oxidative stress (GR). In addition, the comparison of these same parameters between the subgroups consisting of quartiles of GV or glycemic control also showed significant differences. In the DM1 patients studied here, glycemic variability showed correlations with oxidative stress and erythrocyte membrane stability variables. This corroborates the hypothesis that glycemic fluctuations interfere with lipid peroxidation and cell membrane behavior, emphasizing its participation in mechanisms related to the development of chronic complications of diabetes. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Biodiversity and its informative value in evaluation of localities under anthropogenic stress

    International Nuclear Information System (INIS)

    Dusek, L.; Jarkovsky, J.; Hodovsky, J.; Zahradkova, S.; Brabec, K.; Gelnar, M.; Andel, P.

    2003-01-01

    Biomonitoring of aquatic and terrestrial ecosystems became a frequent and valuable approach that is widely recognized as a necessary supplement to still more standard chemical monitoring programmes. Biomonitoring implies bioindication of changes that are routinely viewed as negative changes in biological systems due to the influence of stress factors, mostly of anthropogenic origin. Although there are an increasing number of scientific papers devoted to bioindication at the level of individual species or individual specimen (toxicity and genotoxicity testing, biomarkers etc.), complex biomonitoring at the ecosystem level seems to be rather difficult to manage and interpret. Although biodiversity is one of the central themes of ecology and ecotoxicology as well, there is still considerable disagreement in methodology of its comprehensive evaluation. Here we are presenting several approaches to biodiversity evaluation and results interpretation. Conclusions on methodology and interpretation are made on two sets of data - fish parasites under different environmental conditions and a lichen community under emission loading. We can conclude that biodiversity (community composition and structure) analysis could be used for: i) Retrospective bioindication, where it represents indication of complex changes, sensitive early warning, and indication with long-term memory, and/ or ii) prospective assessment, where it represents ecosystem health and stability. Best results are obtained when the biological community is stratified in order to reach environmentally reasonable units; and, these bioindicative components of the community are necessary for effective monitoring plans or ecological risk assessment studies. (authors)

  12. Productivity and food value of Amaranthus cruentus under non-lethal salt stress

    Science.gov (United States)

    Macler, Bruce A.; Macelroy, Robert D.

    1989-01-01

    Experiments were carried out to analyze the effects of increasing salinity stress on growth, photosynthesis, and carbon allocation in the crop plant Amaranthus. Plants were germinated and grown in Hoagland's solution with NaCl concentrations of 0 to 1.0 percent. The limits of total salinity in the plant growth medium are investigated. For Amaranthus cruentus, germination, vegetative growth, flowering, seed development and yield were normal at salinities from 0 to 0.2 percent. Inhibition of these phases increased from o.2 to 0.4 percent salinity and was total above 0.5 percent with 1 percent salinity was lethal to all developmental phases. Onset of growth phases were not affected by salinity. Plants could not be adapted by gradually increasing salinity over days or weeks. Water uptake increased, while photosynthetic CO2 uptake decreased with increasing salinity on a dry weight basis during vegetative growth. Protein levels were unchanged with increasing salinity. Leaf starch levels were lower at salinities of 0.5 percent and above, while stem starch levels were not affected by these salinities. The evidence supports salt inhibition arising frm changes in primary biochemical processes rather than from effects on water relations. While not addressing the toxic effects of specific ions, it suggests that moderate salinity per se need not be a problem in space systems.

  13. The Effects of a Korean Ginseng, GINST15, on Hypo-Pituitary-Adrenal and Oxidative Activity Induced by Intense Work Stress.

    Science.gov (United States)

    Flanagan, Shawn D; DuPont, William H; Caldwell, Lydia K; Hardesty, Vincent H; Barnhart, Emily C; Beeler, Matthew K; Post, Emily M; Volek, Jeff S; Kraemer, William J

    2018-01-01

    The effect of GINST15, an enzyme fermented ginseng supplement, on hormonal and inflammatory responses to physical stress in humans is unknown. The purpose of this investigation was to examine the constitutive and stress-induced effects of GINST15 supplement on hypo-pituitary-adrenal (HPA) and antioxidant activity in addition to muscle damage. Ten women (age: 38.7 ± 7.8 years; height: 163.81 ± 4.4 cm; body mass 76.0 ± 11.6 kg) and nine men (age: 41.2. ± 9.7 years; height: 177.4 ± 5.3 cm; body mass: 88.5 ± 5.0 kg) participated in a double-blinded, placebo-controlled, counterbalanced within-group study. Participants completed three 14-day treatment cycles with different doses (high: 960 mg; low: 160 mg; placebo: 0 mg) separated by a 1-week washout period. At the end of treatment, physical stress was imposed with intense resistance exercise work stress. Participants provided blood at rest and various time points after exercise (immediately [IP], 30 min [30], 60 min [60], 24 h [+24HR]). Cortisol (CORT), superoxide dismutase (SOD), total glutathione, nonspecific antioxidant activity, total antioxidant power (TAP), and creatine kinase were measured. GINST15 supplementation produced stress-inducible dose-dependent reductions in circulating cortisol and increased enzymatic and nonspecific antioxidant activity. Twenty-four hours after intense exercise, a high dose GINST15, a bioactive ginsenoside metabolite, significantly reduces muscle damage and HPA responses to physical stress in humans; these effects may result from increased antioxidant expression.

  14. Improvement of the calculation of the stress intensity factors for underclad and through-clad defects in a reactor pressure vessel subjected to a pressurised thermal shock

    International Nuclear Information System (INIS)

    Marie, S.; Chapuliot, S.

    2008-01-01

    The analysis of the stability of a defect in a cladded reactor pressure vessel (RPV) of a nuclear pressure water reactor (PWR) subjected to pressurised thermal shock (PTS) is one main elements of the general safety demonstration. Recently, CEA proposed several improved analytical tools for the analysis of the PTS. First, an analytical solution for the vessel through-thickness temperature variation has been developed to deal with any fluid temperature, taking into account the possible presence of a cladding, in the case of an internal PTS. The associated thermal stress expression has been simplified and a complete linearised solution is given for the thermal loading and also for internal pressure, depending on the main vessel material and on the cladding properties. Finally, a complete compendium is also given for the elastic stresses intensity factor calculation. This paper proposes several improvements of the proposed analytical method to deal with a PTS in a PWR cladded vessel. A variable heat transfer coefficient is now taken into account based on an equivalent fluid temperature variation determination, associated with a constant heat transfer coefficient, to keep the same thermal exchange between the fluid and the inner skin of the vessel obtained with the initial data. A more accurate expression for the linearised stresses due to the internal pressure is given, and a possible effect of residual stresses due to the difference between the operating temperature and the stress-free temperature is also taken into account. Finally, an extension of the domain of definition of the influence functions for the elastic stress intensity factor calculation is given

  15. Clinical validity of a relocation stress scale for the families of patients transferred from intensive care units.

    Science.gov (United States)

    Oh, HyunSoo; Lee, Seul; Kim, JiSun; Lee, EunJu; Min, HyoNam; Cho, OkJa; Seo, WhaSook

    2015-07-01

    This study was conducted to develop a family relocation stress scale by modifying the Son's Relocation Stress Syndrome Scale, to examine its clinical validity and reliability and to confirm its suitability for measuring family relocation stress. The transfer of ICU patients to general wards is a significant anxiety-producing event for family members. However, no relocation stress scale has been developed specifically for families. A nonexperimental, correlation design was adopted. The study subjects were 95 family members of 95 ICU patients at a university hospital located in Incheon, South Korea. Face and construct validities of the devised family relocation stress scale were examined. Construct validity was examined using factor analysis and by using a nomological validity test. Reliability was also examined. Face and content validity of the scale were verified by confirming that its items adequately measured family relocation stress. Factor analysis yielded four components, and the total variance explained by these four components was 63·0%, which is acceptable. Nomological validity was well supported by significant relationships between relocation stress and degree of preparation for relocation, patient self-care ability, family burden and satisfaction with the relocation process. The devised scale was also found to have good reliability. The family relocation stress scale devised in this study was found to have good validity and reliability, and thus, is believed to offer a means of assessing family relocation stress. The findings of this study provide a reliable and valid assessment tool when nurses prepare families for patient transfer from an ICU to a ward setting, and may also provide useful information to those developing an intervention programme for family relocation stress management. © 2015 John Wiley & Sons Ltd.

  16. Clinical utility and prognostic value of appropriateness criteria in stress echocardiography for the evaluation of valvular heart disease.

    Science.gov (United States)

    Bhattacharyya, Sanjeev; Kamperidis, Vasilis; Shah, Benoy Nalin; Roussin, Isabelle; Chahal, Navtej; Li, Wei; Khattar, Rajdeep; Senior, Roxy

    2013-09-01

    We examined the prognostic value of stress echocardiography appropriateness criteria for evaluation of valvular heart disease in 100 consecutive patients. Of the studies, 49%, 36%, and 15% were classified as appropriate, uncertain, and inappropriate, respectively. Over a median of 12.6 months, 24 events (12 deaths and 12 heart failure admissions) occurred. The 12-month event-free survival was significantly reduced in patients with appropriate or uncertain studies compared with patients with inappropriate studies (p = 0.04 and p = 0.005, respectively). There was no survival difference between patients with an appropriate or uncertain indication (p = 0.1). The only independent predictors of events were a positive stress echocardiogram (hazard ratio: 15.5, p valvular heart disease provide the ability to differentiate between patients at high- (appropriate group) and low- (inappropriate group) risk of cardiac events. Reclassification of the uncertain group may improve the differential value of these criteria. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  17. Myocardial sestamibi single-photon emission tomography: variations in reference values with gender, age and rest versus stress?

    International Nuclear Information System (INIS)

    Toft, J.; Hesse, B.; Raboel, A.; Carstensen, S.; Ali, S.

    1997-01-01

    Reference data files support the evaluation of myocardial perfusion single-photon emission tomography (SPET). The aim of this study was to create a large reference data base for technetium-99m sestamibi SPET, age and gender matched to the general patient population. One hundred and twenty-eight healthy volunteers (76 males and 52 females) with a likelihood of coronary artery disease of less than 5% underwent rest and maximal exercise 99m Tc-sestamibi SPET with a 2-day protocol and 180 elliptical rotation. The normalized activity values of 99m Tc-sestamibi in the inferior wall differed significantly between men and women. Age variations were found for men in the anterior wall. Normalized activity values in all four walls were strikingly similar during rest and stress. Our results suggest that the use of reference files in 99m Tc-sestamibi SPET requires a gender- and, for males, possibly an age-matched reference population. Different reference files at rest and during stress might not be necessary. (orig.). With 3 figs., 3 tabs

  18. Nuclear Scan Strategy and Outcomes in Chest Pain Patients Value of Stress Testing with Dipyridamole or Adenosine

    International Nuclear Information System (INIS)

    Conti, Alberto; Mariannini, Yuri; Canuti, Erica; Petrova, Tetyana; Innocenti, Francesca; Zanobetti, Maurizio; Gallini, Chiara; Costanzo, Egidio

    2014-01-01

    To update the prognostic value of scan strategy with pharmacological stress agent in chest pain (CP) patients presenting with normal electrocardiography (ECG) and troponin. Two consecutive nonrandomized series of patients with CP and negative first-line workup inclusive of serial ECG, serial troponin, and echocardiography underwent myocardial perfusion imaging single photon emission computed tomography (SPECT) in the emergency department. Of 170 patients enrolled, 52 patients underwent dipyridamole-SPECT and 118 adenosine-SPECT. Patients with perfusion defects underwent angiography, whereas the remaining patients were discharged and followed-up. Primary endpoint was the composite of nonfatal myocardial infarction, unstable angina, revascularization, and cardiovascular death at follow-up or the presence of coronary stenosis > 50% at angiography. At multivariate analysis, the presence of perfusion defects or hypertension was independent predictor of the primary endpoint. Sensitivity and negative predictive value were higher in patients subjected to adenosine-SPECT (95% and 99%, respectively) versus dipyridamole-SPECT (56% and 89%; yield 70% and 11%, respectively; P < 0.03). Of note, sensitivity, negative, and positive predictive values were high in patients with hypertension (100%, 93%, and 60%, respectively) or nonischemic echocardiography alterations (100%, 100%, and 100%, respectively). In CP patients, presenting with normal ECG and troponin, adenosine-SPECT adds incremental prognostic values to dipyridamole-SPECT. Costly scan strategy is more appropriate and avoids unnecessary angiograms in patients with hypertension or nonischemic echocardiography alterations

  19. Stress

    Science.gov (United States)

    ... taking care of an aging parent. With mental stress, the body pumps out hormones to no avail. Neither fighting ... with type 1 diabetes. This difference makes sense. Stress blocks the body from releasing insulin in people with type 2 ...

  20. Comparison of standardized uptake values measured on {sup 18}F-NaF PET/CT scans using three different tube current intensities

    Energy Technology Data Exchange (ETDEWEB)

    Valadares, Agnes Araujo; Woellner, Eduardo Bechtloff; Sapienza, Marcelo Tatit; Buchpiguel, Carlos Alberto, E-mail: agnesvaladares@me.com [Universidade de Sao Paulo (HC/FMUSP), Sao Paulo, SP (Brazil). Fac. de Medicina. Hospital das Clinicas; Duarte, Paulo Schiavom; Coura-Filho, George Barberio [Instituto do Cancer do Estado de Sao Paulo Octavio Frias de Oliveira (ICESP), Sao Paulo, SP (Brazil)

    2015-01-15

    Objective: to analyze standardized uptake values (SUVs) using three different tube current intensities for attenuation correction on {sup 18}FNaF PET/CT scans. Materials and methods: a total of 254 {sup 18}F-NaF PET/CT studies were analyzed using 10, 20 and 30 mAs. The SUVs were calculated in volumes of interest (VOIs) drawn on three skeletal regions, namely, right proximal humeral diaphysis (RH), right proximal femoral diaphysis (RF), and first lumbar vertebra (LV1) in a total of 712 VOIs. The analyses covered 675 regions classified as normal (236 RH, 232 RF, and 207 LV1). Results: mean SUV for each skeletal region was 3.8, 5.4 and 14.4 for RH, RF, and LV1, respectively. As the studies were grouped according to mAs value, the mean SUV values were 3.8, 3.9 and 3.7 for 10, 20 and 30 mAs, respectively, in the RH region; 5.4, 5.5 and 5.4 for 10, 20 and 30 mAs, respectively, in the RF region; 13.8, 14.9 and 14.5 for 10, 20 and 30 mAs, respectively, in the LV1 region. Conclusion: the three tube current values yielded similar results for SUV calculation. (author)

  1. Comparison of standardized uptake values measured on 18F-NaF PET/CT scans using three different tube current intensities

    International Nuclear Information System (INIS)

    Valadares, Agnes Araujo; Woellner, Eduardo Bechtloff; Sapienza, Marcelo Tatit; Buchpiguel, Carlos Alberto

    2015-01-01

    Objective: to analyze standardized uptake values (SUVs) using three different tube current intensities for attenuation correction on 18 FNaF PET/CT scans. Materials and methods: a total of 254 18 F-NaF PET/CT studies were analyzed using 10, 20 and 30 mAs. The SUVs were calculated in volumes of interest (VOIs) drawn on three skeletal regions, namely, right proximal humeral diaphysis (RH), right proximal femoral diaphysis (RF), and first lumbar vertebra (LV1) in a total of 712 VOIs. The analyses covered 675 regions classified as normal (236 RH, 232 RF, and 207 LV1). Results: mean SUV for each skeletal region was 3.8, 5.4 and 14.4 for RH, RF, and LV1, respectively. As the studies were grouped according to mAs value, the mean SUV values were 3.8, 3.9 and 3.7 for 10, 20 and 30 mAs, respectively, in the RH region; 5.4, 5.5 and 5.4 for 10, 20 and 30 mAs, respectively, in the RF region; 13.8, 14.9 and 14.5 for 10, 20 and 30 mAs, respectively, in the LV1 region. Conclusion: the three tube current values yielded similar results for SUV calculation. (author)

  2. Comparison of standardized uptake values measured on F-NaF PET/CT scans using three different tube current intensities.

    Science.gov (United States)

    Valadares, Agnes Araujo; Duarte, Paulo Schiavom; Woellner, Eduardo Bechtloff; Coura-Filho, George Barberio; Sapienza, Marcelo Tatit; Buchpiguel, Carlos Alberto

    2015-01-01

    To analyze standardized uptake values (SUVs) using three different tube current intensities for attenuation correction on (18)FNaF PET/CT scans. A total of 254 (18)F-NaF PET/CT studies were analyzed using 10, 20 and 30 mAs. The SUVs were calculated in volumes of interest (VOIs) drawn on three skeletal regions, namely, right proximal humeral diaphysis (RH), right proximal femoral diaphysis (RF), and first lumbar vertebra (LV1) in a total of 712 VOIs. The analyses covered 675 regions classified as normal (236 RH, 232 RF, and 207 LV1). Mean SUV for each skeletal region was 3.8, 5.4 and 14.4 for RH, RF, and LV1, respectively. As the studies were grouped according to mAs value, the mean SUV values were 3.8, 3.9 and 3.7 for 10, 20 and 30 mAs, respectively, in the RH region; 5.4, 5.5 and 5.4 for 10, 20 and 30 mAs, respectively, in the RF region; 13.8, 14.9 and 14.5 for 10, 20 and 30 mAs, respectively, in the LV1 region. The three tube current values yielded similar results for SUV calculation.

  3. Assessing Covariation of Holocene Monsoon Intensity and Local Moisture Conditions in Eastern and Southwestern Amazon Basin Using Speleothem δ18O and 87Sr/86Sr Values

    Science.gov (United States)

    Ward, B. M.; Wong, C. I.; Novello, V. F.; Silva, L.; McGee, D.; Cheng, H.; Wang, X.; Edwards, R. L.; Cruz, F. W., Sr.; Santos, R. V.

    2017-12-01

    δ18O records from South America offer insight into past variability of the South American Monsoon System (SAMS). Potential, however, for understanding local moisture conditions is limited as precipitation δ18O is strongly influenced by regional climate dynamics. Here we create Holocene speleothem 87Sr/86Sr records at 200-yr resolution using TIMS methods in the Center for Isotope Geochemistry at Boston College to complement existing Holocene δ18O speleothem records and investigate local moisture conditions above caves located in the eastern Amazon Basin (PAR - 4°S, 55°W) and southwestern Brazil (JAR - 21°S, 56°W). Speleothem 87Sr/86Sr variability is interpreted to reflect differences in the extent of water-rock interaction due to differences in infiltration rates under wet and dry conditions. Drier conditions promote longer residence time, enhanced water-rock interaction, and greater evolution of dripwater 87Sr/86Sr values from an initial isotopic signature acquired from the soil to the signature of the cave host rock. PAR speleothem 87Sr/86Sr values range from 0.71024 to 0.71067 and are bracketed by soil (0.71710 to 0.70956) and bedrock (0.70852 to 0.70899) values. JAR speleothem 87Sr/86Sr values range from 0.71216 to 0.71539 and are greater than bedrock values (0.70825 to 0.71219), although some speleothem values exceed the single analysis conducted of the soil isotopic composition (0.71473). JAR speleothem 87Sr/86Sr values increase from the early to mid Holocene, consistent with increase in local moisture availability associated with intensification of the SAMS suggested by decreasing δ18O values in many records from the region. Speleothem 87Sr/86Sr values at JAR decrease from the mid to late Holocene, consistent with an increase in δ18O values at PAR that suggest a decline in monsoon intensity. 87Sr/86Sr variability at JAR, however, is positively correlated with the δ18O record. Preliminary 87Sr/86Sr results from PAR are only broadly consistent with

  4. Regular moderate or intense exercise prevents depression-like behavior without change of hippocampal tryptophan content in chronically tryptophan-deficient and stressed mice.

    Directory of Open Access Journals (Sweden)

    Hosung Lee

    Full Text Available Regular exercise has an antidepressant effect in human subjects. Studies using animals have suggested that the antidepressant effect of exercise is attributable to an increase of brain 5-hydroxytryptamine (5-HT; however, the precise mechanism underlying the antidepressant action via exercise is unclear. In contrast, the effect of 5-HT on antidepressant activity has not been clarified, in part because the therapeutic response to antidepressant drugs has a time lag in spite of the rapid increase of brain 5-HT upon administration of these drugs. This study was designed to investigate the contribution of brain 5-HT to the antidepressant effect of exercise. Mice were fed a tryptophan-deficient diet and stressed using chronic unpredictable stress (CUS for 4 weeks with or without the performance of either moderate or intense exercise on a treadmill 3 days per week. The findings demonstrated that the onset of depression-like behavior is attributable not to chronic reduction of 5-HT but to chronic stress. Regular exercise, whether moderate or intense, prevents depression-like behavior with an improvement of adult hippocampal cell proliferation and survival and without the recovery of 5-HT. Concomitantly, the mice that exercised showed increased hippocampal noradrenaline. Regular exercise prevents the impairment of not long-term memory but short-term memory in a 5-HT-reduced state. Together, these findings suggest that: (1 chronic reduction of brain 5-HT may not contribute to the onset of depression-like behavior; (2 regular exercise, whether moderate or intense, prevents the onset of chronic stress-induced depression-like behavior independent of brain 5-HT and dependent on brain adrenaline; and (3 regular exercise prevents chronic tryptophan reduction-induced impairment of not long-term but short-term memory.

  5. The additional value of first pass myocardial perfusion imaging during peak dose of dobutamine stress cardiac MRI for the detection of myocardial ischemia

    NARCIS (Netherlands)

    Lubbers, Daniel D.; Janssen, Caroline H. C.; Kuijpers, Dirkjan; Van Dijkman, Paul R. M.; Overbosch, Jelle; Willems, Tineke P.; Oudkerk, Matthijs

    Purpose of this study was to assess the additional value of first pass myocardial perfusion imaging during peak dose of dobutamine stress Cardiac-MR (CMR). Dobutamine Stress CMR was performed in 115 patients with an inconclusive diagnosis of myocardial ischemia on a 1.5 T system (Magnetom Avanto,

  6. Predictors of posttraumatic stress and quality of life in family members of chronically critically ill patients after intensive care.

    Science.gov (United States)

    Wintermann, Gloria-Beatrice; Weidner, Kerstin; Strauß, Bernhard; Rosendahl, Jenny; Petrowski, Katja

    2016-12-01

    Prolonged mechanical ventilation for acute medical conditions increases the risk of chronic critical illness (CCI). Close family members are confronted with the life-threatening condition of the CCI patients and are prone to develop posttraumatic stress disorder affecting their health-related quality of life (HRQL). Main aim of the present study was to investigate patient- and family-related risk factors for posttraumatic stress and decreased HRQL in family members of CCI patients. In a cross-sectional design nested within a prospective longitudinal cohort study, posttraumatic stress symptoms and quality of life were assessed in family members of CCI patients (n = 83, aged between 18 and 72 years) up to 6 months after transfer from ICU at acute care hospital to post-acute rehabilitation. Patients admitted a large rehabilitation hospital for ventilator weaning. The Posttraumatic Stress Scale-10 and the Euro-Quality of life-5D-3L were applied in both patients and their family members via telephone interview. A significant proportion of CCI patients and their family members (14.5 and 15.7 %, respectively) showed clinically relevant scores of posttraumatic stress. Both CCI patients and family members reported poorer HRQL than a normative sample. Factors independently associated with posttraumatic stress in family members were the time following ICU discharge (β = .256, 95 % confidence interval .053-.470) and the patients' diagnosis of PTSD (β = .264, 95 % confidence interval .045-.453). Perceived satisfaction with the relationship turned out to be a protective factor for posttraumatic stress in family members of CCI patients (β = -.231, 95 % confidence interval -.423 to -.015). Regarding HRQL in family members, patients' acute posttraumatic stress at ICU (β = -.290, 95 % confidence interval -.360 to -.088) and their own posttraumatic stress 3 to 6 months post-transfer (β = -.622, 95 % confidence interval -.640 to -.358) turned out to be

  7. Hepatoprotective Effect of Quercetin on Endoplasmic Reticulum Stress and Inflammation after Intense Exercise in Mice through Phosphoinositide 3-Kinase and Nuclear Factor-Kappa B

    Directory of Open Access Journals (Sweden)

    Yuhan Tang

    2016-01-01

    Full Text Available The mechanisms underlying intense exercise-induced liver damage and its potential treatments remain unclear. We explored the hepatoprotection and mechanisms of quercetin, a naturally occurring flavonoid, in strenuous exercise-derived endoplasmic reticulum stress (ERS and inflammation. Intense exercise (28 m/min at a 5° slope for 90 min resulted in the leakage of aminotransferases in the BALB/C mice. The hepatic ultrastructural malformations and oxidative stress levels were attenuated by quercetin (100 mg/kg·bw. Intense exercise and thapsigargin- (Tg- induced ERS (glucose-regulated protein 78, GRP78 and inflammatory cytokines levels (IL-6 and TNF-α were decreased with quercetin. Furthermore, quercetin resulted in phosphoinositide 3-kinase (PI3K induction, Ca2+ restoration, and blockade of the activities of Jun N-terminal kinase (JNK, activating transcription factor 6 (ATF6 and especially NF-κB (p65 and p50 nuclear translocation. A PI3K inhibitor abrogated the protection of quercetin on ERS and inflammation of mouse hepatocytes. SP600125 (JNK inhibitor, AEBSF (ATF6 inhibitor, and especially PDTC (NF-κB inhibitor enhanced the quercetin-induced protection against Tg stimulation. Collectively, intense exercise-induced ERS and inflammation were attenuated by quercetin. PI3K/Akt activation and JNK, ATF6, and especially NF-κB suppression were involved in the protection. Our results highlight a novel preventive strategy for treating ERS and inflammation-mediated liver damage induced by intense exercise using natural phytochemicals.

  8. The Effects of Emotional Intelligence (EI Items Education on Job Related Stress in Physicians and Nurses who Work in Intensive Care Units

    Directory of Open Access Journals (Sweden)

    Kh Nooryan

    2011-12-01

    Full Text Available Background & Aim: Intensive care units (ICUs are recognized as stressful environments. The objective of this study was to determine the effects of emotional intelligence education items on job related stress on physicians and nurses who work in intensive care units at hospitals of Yerevan, Armenia. Methods: A interventional study design was implemented with 106 registered hospital physicians and nurses, who were widely distributed all the way through. Case group was taught about 15 E.I items. For data collection, the 20-question Berger situational (overt anxiety questionnaire, the 20-item personality (covert anxiety questionnaire, and the Bar-on emotional intelligence questionnaire with 133 questions were used. Statistical descriptive methods, chi-square (X2 and t-tests were used to analyze data. Results: The research achievements revealed that the average score of the case group`s situational anxiety was 46.59 before intervention, which decreased to 39.95 after the training of the items of emotional intelligence. The average score of situational anxiety of control group was 44.32 before intervention which increased to 44.76 after examination. There was a meaningful statistical difference between case and control group after education of emotional intelligence`s items (p=0.001. Conclusion: Results of the current study showed that physicians and nurses experience high level of stress. The ability to effectively deal with emotion intelligence and emotional information in the workplace assists employees in coping with occupational stress and should be developed in stress managing trainings.

  9. Fatigue threshold studies in Fe, Fe-Si, and HSLA steel: Part II. thermally activated behavior of the effective stress intensity at threshold

    Science.gov (United States)

    Yu, W.; Esaklul, K.; Gerberich, W. W.

    1984-05-01

    It is shown that closure mechanisms alone cannot fully explain increasing fatigue thresholds with decreasing test temperature for a sequence of Fe-Si binary alloys and an HSLA steel. Implications are that fatigue crack propagation near threshold is a thermally activated process. The effective threshold stress intensity, which was obtained by subtracting the closure portion from the fatigue threshold, was examined. This effective stress intensity was found to correlate very well to the thermal component of the flow stress. A detailed fractographic study of the fatigue surface was performed. Water vapor in the room air was found to promote the formation of oxide and intergranular crack growth. At lower temperature, a brittle-type cyclic cleavage fatigue surface was observed but the ductile process persisted even at 123 K. Arrest marks were found on all three modes of fatigue crack growth. The regular spacings between these lines and dislocation modeling suggested that fatigue crack growth was controlled by the subcell structure near threshold. A model based on the slip-off of dislocations was examined. From this, it is shown that the effective fatigue threshold may be related to the square root of (one plus the strain rate sensitivity).

  10. Local topology via the invariants of the velocity gradient tensor within vortex clusters and intense Reynolds stress structures in turbulent channel flow

    International Nuclear Information System (INIS)

    Buchner, Abel-John; Kitsios, Vassili; Atkinson, Callum; Soria, Julio; Lozano-Durán, Adrián

    2016-01-01

    Previous works have shown that momentum transfer in the wall–normal direction within turbulent wall–bounded flows occurs primarily within coherent structures defined by regions of intense Reynolds stress [1]. Such structures may be classified into wall–attached and wall–detached structures with the latter being typically weak, small–scale, and isotropically oriented, while the former are larger and carry most of the Reynolds stresses. The mean velocity fluctuation within each structure may also be used to separate structures by their dynamic properties. This study aims to extract information regarding the scales, kinematics and dynamics of these structures within the topological framework of the invariants of the velocity gradient tensor (VGT). The local topological characteristics of these intense Reynolds stress structures are compared to the topological characteristics of vortex clusters defined by the discriminant of the velocity gradient tensor. The alignment of vorticity with the principal strain directions within these structures is also determined, and the implications of these findings are discussed. (paper)

  11. Comparative Analysis of Signal Intensity and Apparent Diffusion Coefficient at Varying b-values in the Brain : Diffusion Weighted-Echo Planar Image (T2 and FLAIR) Sequence

    International Nuclear Information System (INIS)

    Oh, Jong Kap; Im, Jung Yeol

    2009-01-01

    Diffusion-weighted imaging (DWI) has been demonstrated to be a practical method for the diagnosis of various brain diseases such as acute infarction, brain tumor, and white matter disease. In this study, we used two techniques to examine the average signal intensity (SI) and apparent diffusion coefficient (ADC) of the brains of patients who ranged in age from 10 to 60 years. Our results indicated that the average SI was the highest in amygdala (as derived from DWI), whereas that in the cerebrospinal fluid was the lowest. The average ADC was the highest in the cerebrospinal fluid, whereas the lowest measurement was derived from the pons. The average SI and ADC were higher in T 2 -DW-EPI than in FLAIR-DW-EPI. The higher the b-value, the smaller the average difference in both imaging techniques; the lower the b-value, the greater the average difference. Also, comparative analysis of the brains of patients who had experienced cerebral infarction showed no distinct lesion in the general MR image over time. However, there was a high SI in apparent weighted images. Analysis of other brain diseases (e.g., bleeding, acute, subacute, chronic infarction) indicated SI variance in accordance with characteristics of the two techniques. The higher the SI, the lower the ADC. Taken together, the value of SI and ADC in accordance with frequently occurring areas and various brain disease varies based on the b-value and imaging technique. Because they provide additional useful information in the diagnosis and treatment of patients with various brain diseases through signal recognition, the proper imaging technique and b-value are important for the detection and interpretation of subacute stroke and other brain diseases.

  12. Avaliação do Nível de Estresse da Equipe de Enfermagem em Terapia Intensiva/Evaluation of Stress Level Team Nursing in Intensive Care

    Directory of Open Access Journals (Sweden)

    Patrícia Costa dos Santos da Silva

    2012-12-01

    Full Text Available Objetivo: Avaliar o nível de estresse da equipe de enfermagem que atua em Terapia Intensiva, em um Hospital Universitário do Sul de Minas Gerais. Materiais e Métodos: Trata-se de um estudo descritivo, transversal, de abordagem quantitativa, aprovado pelo Comitê de Ética sob o Parecer nº 48/2011, desenvolvido em uma Unidade de Terapia Intensiva.A amostra constituiu-se de 20 profissionais de enfermagem. Para coleta de dados utilizou-se um questionário com questões semi-estruturadas e o Inventário de Sintomas de Stress para adultos de Lipp. Resultados: Verificou-se que a maioria dos sujeitos encontra-se na faixa etária de 20 a 30 anos (50%. Diante das situações de estresse, notou-se que 55% dos profissionais encontram-se na fase de resistência. A equipe considerou muito desgastante o relacionamento com outras unidades e supervisores (15%, a previsão e reposição de materiais (25%, assistência de enfermagem (10% e as condições de trabalho (10%. Conclusão: O estudo demonstra que a maioria dos profissionais de enfermagem atuante em terapia intensiva, apresenta sinais e sintomas de estresse, principalmente, na fase de resistência. Objective: To evaluate the stress level of the nursing team that works in the Intensive Care Unit in a School Hospital in southern Minas Gerais. Materials and Methods: This is a descriptive transversal study with a quantitative approach, approved by the Ethics Committee under the Opinion n. 48/2011, developed in an intensive care unit. The sample was consisted of 20 nurses. For data collection a questionnaire with semi-structured questions andthe Symptoms of Stress Inventory for adults Lipp was used . Results: It has beenfound that most subjects are aged 20 to 30 years (50%. In the face of stressful situations, it was noted that 55% of professionals are at the stage of resistance. The team considered to be very stressful the relationship with other units and supervisors (15%, forecasting and replenishment

  13. High positive predictive value of Gram stain on catheter-drawn blood samples for the diagnosis of catheter-related bloodstream infection in intensive care neonates.

    Science.gov (United States)

    Deleers, M; Dodémont, M; Van Overmeire, B; Hennequin, Y; Vermeylen, D; Roisin, S; Denis, O

    2016-04-01

    Catheter-related bloodstream infections (CRBSIs) remain a leading cause of healthcare-associated infections in preterm infants. Rapid and accurate methods for the diagnosis of CRBSIs are needed in order to implement timely and appropriate treatment. A retrospective study was conducted during a 7-year period (2005-2012) in the neonatal intensive care unit of the University Hospital Erasme to assess the value of Gram stain on catheter-drawn blood samples (CDBS) to predict CRBSIs. Both peripheral samples and CDBS were obtained from neonates with clinically suspected CRBSI. Gram stain, automated culture and quantitative cultures on blood agar plates were performed for each sample. The paired quantitative blood culture was used as the standard to define CRBSI. Out of 397 episodes of suspected CRBSIs, 35 were confirmed by a positive ratio of quantitative culture (>5) or a colony count of CDBS culture >100 colony-forming units (CFU)/mL. All but two of the 30 patients who had a CDBS with a positive Gram stain were confirmed as having a CRBSI. Seven patients who had a CDBS with a negative Gram stain were diagnosed as CRBSI. The sensitivity, specificity, positive predictive value and negative predictive value of Gram stain on CDBS were 80, 99.4, 93.3 and 98.1 %, respectively. Gram staining on CDBS is a viable method for rapidly (<1 h) detecting CRBSI without catheter withdrawal.

  14. Evidence of Complex Posttraumatic Stress Disorder (CPTSD) across populations with prolonged trauma of varying intensity and ages of exposure

    DEFF Research Database (Denmark)

    Palic, Sabina; Zerach, G; Shevlin, Mark

    2016-01-01

    , with a "Dissociative PTSD-subtype" class. ICD-11's CPTSD was not exclusively associated with childhood abuse, but also with exposure to adulthood trauma of severe interpersonal intensity. Furthermore, all types of prolonged trauma were equally associated with the "Anxiety symptoms" class. Finally, of all the classes......The ICD-11 proposes different types of prolonged trauma as risk factors for complex PTSD (CPTSD). However, CPTSD's construct validity has only been examined in childhood abuse, and single trauma exposure samples. Thus, the extent to which CPTSD applies to other repeatedly traumatized populations...... is unknown. This study examined ICD-11's PTSD and CPTSD across populations with prolonged trauma of varying interpersonal intensity and ages of exposure, including: 1) childhood sexual abuse, 2) adulthood trauma of severe interpersonal intensity (refugees and ex-prisoners of war), and 3) adulthood trauma...

  15. The Pursuit of K: Reflections on the Current State-of-the-Art in Stress Intensity Factor Solutions for Practical Aerospace Applications

    Science.gov (United States)

    CraigMcClung, R.; Lee, Yi-Der; Cardinal, Joseph W.; Guo, Yajun

    2012-01-01

    The elastic stress intensity factor (SIF, commonly denoted as K) is the foundation of practical fracture mechanics (FM) analysis for aircraft structures. This single parameter describes the first-order effects of stress magnitude and distribution as well as the geometry of both structure/component and crack. Hence, the calculation of K is often the most significant step in fatigue analysis based on FM. This presentation will provide several reflections on the current state-of-the-art in SIF solution methods used for practical aerospace applications, including a brief historical perspective, descriptions of some recent and ongoing advances, and comments on some remaining challenges. Newman and Raju made significant early contributions to practical structural analysis by developing closed-form SIF equations for surface and corner cracks in simplified geometries, often based on empirical fits of finite element (FE) solutions. Those solutions (and others like them) were sometimes revised as new analyses were conducted or limitations discovered. The foundational solutions have exhibited striking longevity, despite the relatively "coarse" FE models employed many decades ago. However, in recent years, the accumulation of different generations of solutions for the same nominal geometry has led to some confusion (which solution is correct?), and steady increases in computational capabilities have facilitated the discovery of inaccuracies in some (not all!) of the legacy solutions. Some examples of problems and solutions are presented and discussed, including the challenge of maintaining consistency with legacy design applications. As computational power has increased, the prospect of calculating large numbers of SIF solutions for specific complex geometries with advanced numerical methods has grown more attractive. Fawaz and Andersson, for example, have been generating literally millions of new SIF solutions for different combinations of multiple cracks under simplified

  16. [Diagnostic efficiency of decline rate of signal intensity and apparent diffusion coefficient with different b values for differentiating benign and malignant breast lesions on diffusion-weighted 3.0T magnetic resonance imaging].

    Science.gov (United States)

    Jiang, Jing; Liu, Wanhua; Ye, Yuanyuan; Wang, Rui; Li, Fengfang; Peng, Chengyu

    2014-06-17

    To investigate the diagnostic efficiency of decline rate of signal intensity and apparent diffusion coefficient with different b values for differentiating benign and malignant breast lesions on diffusion-weighted 3.0 T magnetic resonance imaging. A total of 152 patients with 162 confirmed histopathologically breast lesions (85 malignant and 77 benign) underwent 3.0 T diffusion-weighted magnetic resonance imaging. Four b values (0, 400, 800 and 1 000 s/mm²) were used. The signal intensity and ADC values of breast lesions were measured respectively. The signal intensity decline rate (SIDR) and apparent diffusion coefficient decline rate (ADCDR) were calculated respectively. SIDR = (signal intensity of lesions with low b value-signal intensity of lesions with high b value)/signal intensity of lesions with low b value, ADCDR = (ADC value of lesions with low b value-ADC value of lesions with high b value) /ADC value of lesions with low b value. The independent sample t-test was employed for statistical analyses and the receiver operating characteristic (ROC) curve for evaluating the diagnosis efficiency of SIDR and ADCDR values. Significant differences were observed in SIDR between benign and malignant breast lesions with b values of 0-400, 400-800 and 800-1 000 s/mm². The sensitivities of SIDR for differentiating benign and malignant breast lesions were 61.2%, 68.2% and 67.1%, the specificities 74.0%, 85.7% and 67.5%, the diagnosis accordance rates 67.3%, 76.5% and 67.3%, the positive predictive values 72.2%, 84.1% and 69.5% and the negative predictive values 63.3%, 71.0% and 65.0% respectively. Significant differences were observed in ADCDR between benign and malignant breast lesions with b values of 400-800 s/mm² and 800-1 000 s/mm². The sensitivities of SDR for differentiating benign and malignant breast lesions were 80.0% and 65.9%, the specificities 72.7% and 65.0%, the diagnostic accordance rates 76.5% and 65.4%, the positive predictive values 76.4% and 67

  17. Enhanced biofuel production potential with nutritional stress amelioration through optimization of carbon source and light intensity in Scenedesmus sp. CCNM 1077.

    Science.gov (United States)

    Pancha, Imran; Chokshi, Kaumeel; Mishra, Sandhya

    2015-03-01

    Microalgal mixotrophic cultivation is one of the most potential ways to enhance biomass and biofuel production. In the present study, first of all ability of microalgae Scenedesmus sp. CCNM 1077 to utilize various carbon sources under mixotrophic growth condition was evaluated followed by optimization of glucose concentration and light intensity to obtain higher biomass, lipid and carbohydrate contents. Under optimized condition i.e. 4 g/L glucose and 150 μmol m(-2) s(-1) light intensity, Scenedesmus sp. CCNM 1077 produced 1.2g/L dry cell weight containing 23.62% total lipid and 42.68% carbohydrate. Addition of glucose shown nutritional stress ameliorating effects and around 70% carbohydrate and 25% total lipid content was found with only 21% reduction in dry cell weight under nitrogen starved condition. This study shows potential application of mixotrophically grown Scenedesmus sp. CCNM 1077 for bioethanol and biodiesel production feed stock. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Stress intensity evaluation for surface crack with use of boundary element method and influence function method and the surface crack extension analysis

    International Nuclear Information System (INIS)

    Yuuki, R.; Ejima, K.

    1991-01-01

    In this study, three-dimensional boundary element elastostatic analysis is carried out on various surface crack problems. The present BEM uses a Mindlin's solution as well as a Kelvin's solution as a fundamental solution. So we can obtain accurate solutions for a surface crack just before or after a penetration. The obtained solutions for various shapes of surface cracks are stored as the data base, based on the influence function method. We develop the surface crack extension analysis system using the stress intensity factor data base and also the fatigue crack growth law. Our system seems to be useful especially for the analysis of the surface crack just before or after the penetration and also under the residual stresses

  19. Fatigue threshold studies in Fe, Fe-Si, and HSLA steel: Part II. Thermally activated behavior of the effective stress intensity at threshold

    International Nuclear Information System (INIS)

    Yu, W.; Esaklul, K.; Gerberich, W.W.

    1984-01-01

    It is shown that closure mechanisms alone cannot fully explain increasing fatigue thresholds with decreasing test temperature. Implications are that fatigue crack propagation near threshold is a thermally activated process. The effective threshold stress intensity correlate to the thermal component of the flow stress. A fractographic study of the fatigue surface was performed. Water vapor in room air promotes the formation of oxide and intergranular crack growth. At lower temperatures, a brittle-type cyclic cleavage fatigue surface was observed but the ductile process persisted even at 123 K. Arrest marks found on all three modes of fatigue crack growth suggest that fatigue crack growth controlled by the subcell structure near threshold. The effective fatigue threshold may be related to the square root of (one plus the strain rate sensitivity)

  20. A Brief Cognitive-Behavioral Psycho-Education (B-CBE Program for Managing Stress and Anxiety of Main Family Caregivers of Patients in the Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Vico Chung Lim Chiang

    2016-09-01

    Full Text Available Having a loved one in the intensive care unit (ICU is a stressful event, which may cause a high level of anxiety to the family members. This could threaten their wellbeing and ability to support the patients in, or after discharge from, the ICU. To investigate the outcomes of a brief cognitive-behavioral psycho-education program (B-CBE to manage stress and anxiety of the main family caregivers (MFCs, a pragmatic quasi-experimental study involving 45 participants (treatment group: 24; control group: 21 was conducted in an ICU. The Depression and Anxiety Stress Scale and the Critical Care Family Need Inventory were used to evaluate the primary outcomes on stress and anxiety, and satisfaction with family needs. The treatment group reported significantly better improvement in the information satisfaction score compared to the control group (p < 0.05; η2 = 0.09. Overall main effects were observed on the stress (p < 0.01; η2 = 0.20, anxiety (p < 0.01; η2 = 0.18, depression (p < 0.05; η2 = 0.13, support satisfaction (p < 0.05; η2 = 0.13, and comfort satisfaction (p < 0.05; η2 = 0.11 scores. The experience of this study suggest that MFCs are in great need of additional support like B-CBE to manage their stress and anxiety. Given the brevity of B-CBE, it is practical for critical care nurses to deliver and MFCs to take within the industrious context of an ICU. More studies are needed to investigate these types of brief psychological interventions.

  1. Diffusion-weighted magnetic resonance imaging for the initial characterization of non-fatty soft tissue tumors: correlation between T2 signal intensity and ADC values

    Energy Technology Data Exchange (ETDEWEB)

    Gondim Teixeira, Pedro Augusto [Service d' Imagerie Guilloz, CHU Nancy, Nancy (France); Universite de Lorraine, IADI, UMR S 947, Vandoeuvre-les-Nancy (France); Gay, Frederique; Blum, Alain [Service d' Imagerie Guilloz, CHU Nancy, Nancy (France); Chen, Bailiang; Felblinger, Jacques [Universite de Lorraine, IADI, UMR S 947, Vandoeuvre-les-Nancy (France); Zins, Marie [University Versailles St-Quentin, Versailles (France); Inserm, Centre for research in Epidemiology and Population Health (CESP), U1018, Villejuif (France); Sirveaux, Francois [Centre Chirurgical Emile Galle, Service de Chirurgie Traumatologique et Orthopedique, Nancy (France)

    2016-02-15

    To evaluate the performance of quantitative diffusion-weighted imaging (DWI) correlated with T2 signal in differentiating non-fatty benign from malignant tumors. A total of 76 patients with a histologically confirmed non-fatty soft tissue tumors (46 benign and 30 malignant) were prospectively included in this ethics committee approved study. All patients signed an informed consent and underwent MRI with DWI with two b values (0 and 600). ADC values from the solid components of these tumors were obtained and were correlated with the lesion's signal intensity on T2-weighted fat-saturated sequences. ADC values were obtained from adjacent normal muscle to allow calculation of tumor/muscle ADC ratios. There were 58 hyperintense and 18 iso or hypointense lesions. All hypointense lesions were benign. The mean ADC values for benign and malignant tumors were 1.47 ± 0.54 x 10{sup -3} and 1.17 ± 0.38 x 10{sup -3} mm{sup 2}/s respectively (p < 0.005). The mean ADC ratio in benign iso or hypointense tumors was significantly lower than that of hyperintense ones (0.76 ± 0.21 versus 1.58 ± 0.82 - p < 0.0001). An ADC ratio lower than 0.915 was highly specific for malignancy (96.4 %), whereas an ADC ratio higher than 1.32 was highly sensitive for benign lesions (90 %). ADC analysis can be useful in the initial characterization of T2 hyperintense non-fatty soft tissue masses, although this technique alone is not likely to change patient management. (orig.)

  2. 24-Epibrassinoslide enhances plant tolerance to stress from low temperatures and poor light intensities in tomato (Lycopersicon esculentum Mill.).

    Science.gov (United States)

    Cui, Lirong; Zou, Zhirong; Zhang, Jing; Zhao, Yanyan; Yan, Fei

    2016-01-01

    Brassinosteroids (Brs) are a newly recognized group of active steroidal hormones that occur at low concentrations in all plant parts and one of the active and stable forms is 24-epibrassinolide (EBR). We investigated the effect of EBR on tomato (Lycopersicon esculentum Mill.) and its mechanism when seedlings were exposed to low temperature and poor light stress conditions. Leaves of stress-tolerant 'Zhongza9' and stress-sensitive 'Zhongshu4' cultivars were pre-treated with spray solutions containing either 0.1 μM EBR or no EBR (control). The plants were then transferred to chambers where they were exposed to low temperatures of 12 °C/6 °C (day/night) under a low light (LL) level of 80 μmol · m(-2) · s(-1). Exogenous application of EBR significantly increased the antioxidant activity of superoxide dismutase, catalase and peroxidase, and decreased the rate of O2 · (-) formation and H2O2 and malondialdehyde contents. Additionally, the ATP synthase β subunit content was increased by exogenous hormone application. Based on these results, we conclude that exogenous EBR can elicit synergism between the antioxidant enzyme systems and the ATP synthase β subunit so that scavenging of reactive oxygen species becomes more efficient. These activities enable plants to cope better under combined low temperature and poor light stresses.

  3. MRI-detected skull-base invasion. Prognostic value and therapeutic implication in intensity-modulated radiotherapy treatment for nasopharyngeal carcinoma

    International Nuclear Information System (INIS)

    Cheng, Yi-Kan; Jiang, Ning; Yue, Dan; Tang, Ling-Long; Zhang, Fan; Lin, Li; Liu, Xu; Chen, Lei; Ma, Jun; Liu, Li-Zhi

    2014-01-01

    With advances in imaging and radiotherapy, the prognostic value of skull-base invasion in nasopharyngeal carcinoma (NPC) needs to be reassessed. We aimed to define a classification system and evaluate the prognostic value of the classification of magnetic resonance imaging (MRI)-detected skull-base invasion in NPC treated with intensity-modulated radiotherapy (IMRT). We retrospectively reviewed 749 patients who underwent MRI and were subsequently histologically diagnosed with nondisseminated NPC and treated with IMRT. MRI-detected skull-base invasion was not found to be an independent prognostic factor for overall survival (OS), distant metastasis-free survival (DMFS), local relapse-free survival (LRFS), or disease-free survival (DFS; p > 0.05 for all). Skull-base invasion was classified according to the incidence of each site (type I sites inside pharyngobasilar fascia and clivus vs. type II sites outside pharyngobasilar fascia). The 5-year OS, DMFS, LRFS, and DFS rates in the classification of skull-base invasion in NPC were 83 vs. 67 %, 85 vs.75 %, 95 vs. 88 %, and 76 vs. 62 %, respectively (p [de

  4. Comparative analysis of salt stress, duration and intensity, on the chloroplast ultrastructure and photosynthetic apparatus in Thellungiella salsuginea.

    Science.gov (United States)

    Goussi, Rahma; Manaa, Arafet; Derbali, Walid; Cantamessa, Simone; Abdelly, Chedly; Barbato, Roberto

    2018-06-01

    Salinity is one of the most important abiotic stress affecting plant growth and productivity worldwide. Photosynthesis, together with cell growth, is among the primary process affected by salinity. Here, we report the effects of salt stress on photosynthesis in the model halophyte Thellungiella salsuginea. Plants were grown in hydroponic system and then treated for 2 weeks with different NaCl concentrations (0, 100, 200 and 400 mM). Leaf analysis using both photonic and transmission electron microscopes showed some changes in mesophyll cell organization, including shape and dimension. Under high NaCl concentration (400 mM) a swelling of thylakoids and starch accumulation was also observed. The obtained results also showed a change in the photosynthetic efficiency of both photosystems (PSI and PSII), depending on both NaCl concentrations and duration of the stress treatment. Under moderate salinity (100 and 200 mM NaCl) no significant variation was observed in PSI and PSII yield parameters. Chlorophyll a fluorescence transient showed some variations in OJ, JI and IP phases under salt stress depending also on NaCl levels and the duration of stress. Under high salinity PSII donor side was affected as well as quantum yield of PSI which also showed a donor side limitation. A significant decrease on quantum yields Y(I) and Y(II) under high salt treatment (400 mM NaCl) for prolonged period of time (15 days) was observed. The decrease of these parameters was quantitatively compensated by a corresponding increase of energy thermal dissipation Y(NPQ) in photosystem II and a increase in the Y(ND) in PSI. Analysis of derived parameters from the OJIP transient curve revealed that ABS/RC decreased under NaCl treatment by reason of the increase in size of antenna of active reaction centers. An increase in the performance index PI (ABS) , a slight decrease in the rate of DI O /RC, TR O /RC and the level of electron transport per PSII RC (ET O /RC) were observed during

  5. Influence of the crack propagation rate in the obtaining opening and closing stress intensity factor by finite element method

    OpenAIRE

    Luiz Carlos H. Ricardo; Carlos Alexandre J. Miranda

    2016-01-01

    Crack propagation simulation began with the development of the finite element method; the analyses were conducted to obtain a basic understanding of the crack growth. Today structural and materials engineers develop structures and materials properties using this technique as criterion design. The aim of this paper is to verify the effect of different crack propagation rates in determination of crack opening and closing stress of an ASTM specimen under a standard suspension spectrum loading fr...

  6. Stress-induced brain histone H3 phosphorylation: contribution of the intensity of stressors and length of exposure.

    Science.gov (United States)

    Rotllant, David; Pastor-Ciurana, Jordi; Armario, Antonio

    2013-05-01

    Expression of c-fos is used for the characterization of brain areas activated by stressors. Recently, some epigenetic markers associated with enhanced transcription have been identified that may be also useful to detect neuronal populations important for the processing of stressors: phosphorylation of histone H3 in serine 10 or 28 (pH3S₁₀ or pH3S₂₈). Then, we compared in rats the response to stress of c-fos and these epigenetic changes. More specifically, we studied the influence of the type of stressor (novel environment vs. immobilization, IMO) and the dynamics of the response to IMO. Stress increased pH3S₁₀ positive neurons, with a more restricted pattern than that of c-fos, both in terms of brain areas activated and number of positive neurons. Changes in pH3S₁₀ showed a maximum at 30 min, then progressively declining in most areas in spite of the persistence of IMO. Moreover, the decline was in general more sensitive than c-fos to the termination of IMO. The pattern of pH3S₂₈ was even more restricted that of pH3S₁₀, but they showed co-localization. The present data demonstrate a more selective pattern of stress-induced histone H3 phosphorylation than c-fos. The factors determining such a selectivity and its biological meaning remain to be studied. © 2013 International Society for Neurochemistry.

  7. [The combined action of drinking mineral water and low-intensity electromagnetic radiation under the immobilization stress conditions (an experimental study)].

    Science.gov (United States)

    Korolev, Yu N; Bobrovnitsky, I P; Geniatulina, M S; Mikhailik, L V; Nikulina, L A; Bobkova, A S; Yakovlev, M Yu

    2015-01-01

    The present study carried out on white male rats in experiments with the use of biochemical, radioimmunological, and electron- microscopic methods. It was shown that the combined treatment with potable mineral water (MV) and low-intensity electromagnetic radiation (LIEMR) of ultrahigh frequency (power density less than 1 pW/cm2, the frequency about 1000 MHz) facilitated the activation of metabolic and intracellular regenerative processes in the liver and testes. One of the advantages of the combined application of MV and LIEMR over the single-factor treatment manifested itself as the weakening of stress reactions, the increase in the frequency of the plastic processes, and the more harmonious development of different forms of intracellular regeneration. The results of the study provide a deeper insight ino the mechanisms underlying the combined actions of drinking mineral water and low-intensity electromagnetic radiation; also, they justify the application of these factors for the protection of the reproductive system and the entire body from stress-induced disorders.

  8. Application of A Physiological Strain Index in Evaluating Responses to Exercise Stress – A Comparison Between Endurance and High Intensity Intermittent Trained Athletes

    Directory of Open Access Journals (Sweden)

    Pokora Ilona

    2016-04-01

    Full Text Available The study evaluated differences in response to exercise stress between endurance and high-intensity intermittent trained athletes in a thermoneutral environment using a physiological strain index (PSI. Thirty-two subjects participated in a running exercise under normal (23°C, 50% RH conditions. The group included nine endurance trained athletes (middle-distance runners - MD, twelve high-intensity intermittent trained athletes (soccer players - HIIT and eleven students who constituted a control group. The exercise started at a speed of 4 km·h–1 which was increased every 3 min by 2 km·h–1 to volitional exhaustion. The heart rate was recorded with a heart rate monitor and aural canal temperature was measured using an aural canal temperature probe. The physiological strain index (PSI and the contribution of the circulatory and thermal components to the overall physiological strain were calculated from the heart rate and aural canal temperature. The physiological strain index differed between the study and control participants, but not between the MD and HIIT groups. The physiological strain in response to exercise stress in a thermoneutral environment was mainly determined based on the circulatory strain (MD group - 73%, HIIT group – 70%. The contribution of the circulatory and thermal components to the physiological strain did not differ significantly between the trained groups (MD and HIIT despite important differences in morphological characteristics and training-induced systemic cardiovascular and thermoregulatory adaptations.

  9. Increased objectively assessed vigorous-intensity exercise is associated with reduced stress, increased mental health and good objective and subjective sleep in young adults.

    Science.gov (United States)

    Gerber, Markus; Brand, Serge; Herrmann, Christian; Colledge, Flora; Holsboer-Trachsler, Edith; Pühse, Uwe

    2014-08-01

    The role of physical activity as a factor that protects against stress-related mental disorders is well documented. Nevertheless, there is still a dearth of research using objective measures of physical activity. The present study examines whether objectively assessed vigorous physical activity (VPA) is associated with mental health benefits beyond moderate physical activity (MPA). Particularly, this study examines whether young adults who accomplish the American College of Sports Medicine's (ACSM) vigorous-intensity exercise recommendations differ from peers below these standards with regard to their level of perceived stress, depressive symptoms, perceived pain, and subjective and objective sleep. A total of 42 undergraduate students (22 women, 20 men; M=21.24years, SD=2.20) volunteered to take part in the study. Stress, pain, depressive symptoms, and subjective sleep were assessed via questionnaire, objective sleep via sleep-EEG assessment, and VPA via actigraphy. Meeting VPA recommendations had mental health benefits beyond MPA. VPA was associated with less stress, pain, subjective sleep complaints and depressive symptoms. Moreover, vigorous exercisers had more favorable objective sleep pattern. Especially, they had increased total sleep time, more stage 4 and REM sleep, more slow wave sleep and a lower percentage of light sleep. Vigorous exercisers also reported fewer mental health problems if exposed to high stress. This study provides evidence that meeting the VPA standards of the ACSM is associated with improved mental health and more successful coping among young people, even compared to those who are meeting or exceeding the requirements for MPA. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Effect of the Yield Stress and r-value Distribution on the Earing Profile of Cup Drawing with Yld2000-2d Yield Function

    Science.gov (United States)

    Lou, Yanshan; Bae, Gihyun; Lee, Changsoo; Huh, Hoon

    2010-06-01

    This paper deals with the effect of the yield stress and r-value distribution on the earing in the cup drawing. The anisotropic yield function, Yld2000-2d yield function, is selected to describe the anisotropy of two metal sheets, 719B and AA5182-O. The tool dimension is referred from the Benchmark problem of NUMISHEET'2002. The Downhill Simplex method is applied to identify the anisotropic coefficients in Yld2000-2d yield function. Simulations of the drawing process are performed to investigate the earing profile of two materials. The earing profiles obtained from simulations are compared with the analytical model developed by Hosford and Caddell. Simulations are conducted with respect to the change of the yield stress and r-value distribution, respectively. The correlation between the anisotropy and the earing tendency is investigated based on simulation data. Finally, the earing mechanism is analyzed through the deformation process of the blank during the cup deep drawing. It can be concluded that ears locate at angular positions with lower yield stress and higher r-value while the valleys appear at the angular position with higher yield stress and lower r-value. The effect of the yield stress distribution is more important for the cup height distribution than that of the r-value distribution.

  11. Stress

    DEFF Research Database (Denmark)

    Keller, Hanne Dauer

    2015-01-01

    Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb.......Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb....

  12. Stress !!!

    OpenAIRE

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten. Opvallend is dat mannelijke studenten uit Twente zich veel minder druk lijken te maken over hun studie. Onder vrouwen ligt de stress juist erg hoog ten opzichte van het landelijk gemiddelde.

  13. Effects of High-Intensity Swimming on Lung Inflammation and Oxidative Stress in a Murine Model of DEP-Induced Injury.

    Science.gov (United States)

    Ávila, Leonardo C M; Bruggemann, Thayse R; Bobinski, Franciane; da Silva, Morgana Duarte; Oliveira, Regiane Carvalho; Martins, Daniel Fernandes; Mazzardo-Martins, Leidiane; Duarte, Marta Maria Medeiros Frescura; de Souza, Luiz Felipe; Dafre, Alcir; Vieira, Rodolfo de Paula; Santos, Adair Roberto Soares; Bonorino, Kelly Cattelan; Hizume Kunzler, Deborah de C

    2015-01-01

    Studies have reported that exposure to diesel exhaust particles (DEPs) induces lung inflammation and increases oxidative stress, and both effects are susceptible to changes via regular aerobic exercise in rehabilitation programs. However, the effects of exercise on lungs exposed to DEP after the cessation of exercise are not clear. Therefore, the aim of this study was to evaluate the effects of high-intensity swimming on lung inflammation and oxidative stress in mice exposed to DEP concomitantly and after exercise cessation. Male Swiss mice were divided into 4 groups: Control (n = 12), Swimming (30 min/day) (n = 8), DEP (3 mg/mL-10 μL/mouse) (n = 9) and DEP+Swimming (n = 8). The high-intensity swimming was characterized by an increase in blood lactate levels greater than 1 mmoL/L between 10th and 30th minutes of exercise. Twenty-four hours after the final exposure to DEP, the anesthetized mice were euthanized, and we counted the number of total and differential inflammatory cells in the bronchoalveolar fluid (BALF), measured the lung homogenate levels of IL-1β, TNF-α, IL-6, INF-ϫ, IL-10, and IL-1ra using ELISA, and measured the levels of glutathione, non-protein thiols (GSH-t and NPSH) and the antioxidant enzymes catalase and glutathione peroxidase (GPx) in the lung. Swimming sessions decreased the number of total cells (pswimming groups compared with the control groups, as did the CAT lung levels (p = 0.0001). Simultaneously, swimming resulted in an increase in the GSH-t and NPSH lung levels in the DEP group (p = 0.0001 and pswimming sessions decreased the lung inflammation and oxidative stress status during DEP-induced lung inflammation in mice.

  14. Stress intensity factor at the tip of cladding incipient crack in RIA-simulating experiments for high-burnup PWR fuels

    International Nuclear Information System (INIS)

    Udagawa, Yutaka; Suzuki, Motoe; Sugiyama, Tomoyuki; Fuketa, Toyoshi

    2009-01-01

    RIA-simulating experiments for high-burnup PWR fuels have been performed in the NSRR, and the stress intensity factor K 1 at the tip of cladding incipient crack has been evaluated in order to investigate its validity as a PCMI failure threshold under RIA conditions. An incipient crack depth was determined by observation of metallographs. The maximum hydride-rim thickness in the cladding of the test fuel rod was regarded as the incipient crack depth in each test case. Hoop stress in the cladding periphery during the pulse power transient was calculated by the RANNS code. K 1 was calculated based on crack depth and hoop stress. According to the RANNS calculation, PCMI failure cases can be divided into two groups: failure in the elastic phase and failure in the plastic phase. In the former case, elastic deformation was predominant around the incipient crack at failure time. K 1 is available only in this case. In the latter, plastic deformation was predominant around the incipient crack at failure time. Failure in the elastic phase never occurred when K 1 was less than 17 MPa m 1/2 . For failure in the plastic phase, the plastic hoop strain of the cladding periphery at failure time clearly showed a tendency to decrease with incipient crack depth. The combination of K 1 , for failure in the elastic phase, and plastic hoop strain at failure, for failure in the plastic phase, can be an effective index of PCMI failure under RIA conditions. (author)

  15. Early intra-intensive care unit psychological intervention promotes recovery from post traumatic stress disorders, anxiety and depression symptoms in critically ill patients.

    Science.gov (United States)

    Peris, Adriano; Bonizzoli, Manuela; Iozzelli, Dario; Migliaccio, Maria Luisa; Zagli, Giovanni; Bacchereti, Alberto; Debolini, Marta; Vannini, Elisetta; Solaro, Massimo; Balzi, Ilaria; Bendoni, Elisa; Bacchi, Ilaria; Trevisan, Monica; Giovannini, Valtere; Belloni, Laura

    2011-01-01

    Critically ill patients who require intensive care unit (ICU) treatment may experience psychological distress with increasing development of psychological disorders and related morbidity. Our aim was to determine whether intra-ICU clinical psychologist interventions decrease the prevalence of anxiety, depression and posttraumatic stress disorder (PTSD) after 12 months from ICU discharge. Our observational study included critical patients admitted before clinical psychologist intervention (control group) and patients who were involved in a clinical psychologist program (intervention group). The Hospital Anxiety and Depression Scale (HADS) and Impact of Event Scale-Revised questionnaires were used to assess the level of posttraumatic stress, anxiety and depression symptoms. The control and intervention groups showed similar demographic and clinical characteristics. Patients in the intervention group showed lower rates of anxiety (8.9% vs. 17.4%) and depression (6.5% vs. 12.8%) than the control group on the basis of HADS scores, even if the differences were not statistically significant. High risk for PTSD was significantly lower in patients receiving early clinical psychologist support than in the control group (21.1% vs. 57%; P < 0.0001). The percentage of patients who needed psychiatric medications at 12 months was significantly higher in the control group than in the patient group (41.7% vs. 8.1%; P < 0.0001). Our results suggest that that early intra-ICU clinical psychologist intervention may help critically ill trauma patients recover from this stressful experience.

  16. Demographic and occupational predictors of stress and fatigue in French intensive-care registered nurses and nurses' aides: a cross-sectional study.

    Science.gov (United States)

    Jones, Gabrielle; Hocine, Mounia; Salomon, Jérôme; Dab, William; Temime, Laura

    2015-01-01

    Healthcare workers (HCWs) working in intensive-care units (ICUs) are exposed to high physical and mental demands potentially affecting their health or having repercussions on patient care. Although several studies have explored the links between some aspects of working conditions in hospitals and HCW health, the complex dynamics at play are not fully understood. This study aimed to explore the impact of a wide array of demographic, employment and organizational factors related to fatigue and stress of French ICU HCWs. A cross-sectional study was conducted in ICUs of Paris-area hospitals between January 18, 2013 and April 2, 2013. All types of adult ICUs were included (medical, surgical and polyvalent). Included in the study were HCWs with patient contact (doctors, residents, registered nurses, nurse's aides and physical therapists). Participation was proposed to all eligible HCWs present during on-site visits. Temporary staff not typically assigned to the given ICU was excluded. Data were collected using an individual questionnaire administered in interviews during day and night shifts (N=682). Stress and fatigue outcomes included the 10-item Perceived Stress Scale (PSS10), the Nottingham Health Profile sleep and energy level rubrics and the current fatigue state at the interview. Multivariate analysis was restricted to nurse and nurse's aide data (n=536). Doctors and residents reported fewer sleep difficulties but were more likely to report a tired current state. Female gender was associated with higher stress levels and greater fatigue for all outcomes, while greater social support of supervisor or colleagues decreased stress and fatigue. At the organizational level, longer shifts (12 h vs. 8 h) were associated with tired current state and greater sleep difficulties. Personnel on rotating shifts had lower stress and a better current state, while those on night shifts had greater sleep and energy level difficulties. Even when controlling for demographic factors

  17. Value and limitations of segmental analysis of stress thallium myocardial imaging for localization of coronary artery disease

    International Nuclear Information System (INIS)

    Rigo, P.; Bailey, I.K.; Griffith, L.S.C.; Pitt, B.; Borow, R.D.; Wagner, H.N.; Becker, L.C.

    1980-01-01

    This study was done to determine the value of thallium-201 myocardial scintigraphic imaging (MSI) for identifying disease in the individual coronary arteries. Segmental analysis of rest and stress MSI was performed in 133 patients with ateriographically proved coronary artery disease (CAD). Certain scintigraphic segments were highly specific (97 to 100%) for the three major coronary arteries: anterior wall and septum for the left anterior descending (LAD) coronary artery; the inferior wall for the right coronary artery (RCA); and the proximal lateral wall for the circumflex (LCX) artery. Perfusion defects located in the anterolateral wall in the anterior view were highly specific for proximal disease in the LAD involving the major diagonal branches, but this was not true for septal defects. The apical segments were not specific for any of the three major vessels. Although MSI was abnormal in 89% of these patients with CAD, it was less sensitive for identifying individual vessel disease: 63% for LAD, 50% for RCA, and 21% for LCX disease (narrowings > = 50%). Sensitivity increased with the severity of stenosis, but even for 100% occlusions was only 87% for LAD, 58% for RCA and 38% for LCX. Sensitivity diminished as the number of vessels involved increased: with single-vessel disease, 80% of LAD, 54% of RAC and 33% of LCX lesions were detected, but in patients with triple-vessel disease, only 50% of LAD, 50% of RCA and 16% of LCX lesions were identified. Thus, although segmented analysis of MSI can identify disease in the individual coronary arteries with high specificity, only moderate sensitivity is achieved, reflecting the tendency of MSI to identify only the most severely ischemic area among several that may be present in a heart. Perfusion scintigrams display relative distributions rather than absolute values for myocardial blood flow

  18. Assessing archetypes of organizational culture based on the Competing Values Framework: the experimental use of the framework in Japanese neonatal intensive care units.

    Science.gov (United States)

    Sasaki, Hatoko; Yonemoto, Naohiro; Mori, Rintaro; Nishida, Toshihiko; Kusuda, Satoshi; Nakayama, Takeo

    2017-06-01

    To assess organizational culture in neonatal intensive care units (NICUs) in Japan. Cross-sectional survey of organizational culture. Forty NICUs across Japan. Physicians and nurses who worked in NICUs (n = 2006). The Competing Values Framework (CVF) was used to assess the organizational culture of the study population. The 20-item CVF was divided into four culture archetypes: Group, Developmental, Hierarchical and Rational. We calculated geometric means (gmean) and 95% bootstrap confidence intervals of the individual dimensions by unit and occupation. The median number of staff, beds, physicians' work hours and work engagement were also calculated to examine the differences by culture archetypes. Group (gmean = 34.6) and Hierarchical (gmean = 31.7) culture archetypes were higher than Developmental (gmean = 16.3) and Rational (gmean = 17.4) among physicians as a whole. Hierarchical (gmean = 36.3) was the highest followed by Group (gmean = 25.8), Developmental (gmean = 16.3) and Rational (gmean = 21.7) among nurses as a whole. Units with dominant Hierarchical culture had a slightly higher number of physicians (median = 7) than dominant Group culture (median = 6). Units with dominant Group culture had a higher number of beds (median = 12) than dominant Hierarchical culture (median = 9) among physicians. Nurses from units with a dominant Group culture (median = 2.8) had slightly higher work engagement compared with those in units with a dominant Hierarchical culture (median = 2.6). Our findings revealed that organizational culture in NICUs varies depending on occupation and group size. Group and Hierarchical cultures predominated in Japanese NICUs. Assessing organizational culture will provide insights into the perceptions of unit values to improve quality of care. © The Author 2017. Published by Oxford University Press in association with the International Society for Quality in Health Care

  19. Incremental value of contrast myocardial perfusion to detect intermediate versus severe coronary artery stenosis during stress-echocardiography

    Directory of Open Access Journals (Sweden)

    Ugo Fabrizio

    2010-05-01

    Full Text Available Abstract Background We aimed to compare the incremental value of contrast myocardial perfusion imaging (MPI for the detection of intermediate versus severe coronary artery stenosis during dipyridamole-atropine echocardiography (DASE. Wall motion (WM assessment during stress-echocardiography demonstrates suboptimal sensitivity to detect coronary artery disease (CAD, particularly in patients with isolated intermediate (50%-70% coronary stenosis. Methods We performed DASE with MPI in 150 patients with a suspected chest pain syndrome who were given clinical indication to coronary angiography. Results and discussion When CAD was defined as the presence of a ≥50% stenosis, the addition of MPI increased sensitivity (+30% and decreased specificity (-14%, with a final increase in total diagnostic accuracy (+16%, p Conclusions The addition of MPI on top of WM analysis during DASE increases the diagnostic sensitivity to detect obstructive CAD, whatever its definition (≥50% or > 70% stenosis, but it is mainly driven by the sensitivity increase in the intermediate group (50%-70% stenosis. The total diagnostic accuracy increased only when defining CAD as ≥50% stenosis, since in patients with severe stenosis (> 70% the decrease in specificity is not counterbalanced by the minor sensitivity increase.

  20. Analysis of the influence of the complex structure of clay hollow bricks on the values of electric field intensity by using the FDTD method

    Directory of Open Access Journals (Sweden)

    Choroszucho Agnieszka

    2016-12-01

    Full Text Available The study presents the analysis of the effects occurring at the propagation of electromagnetic waves within an area containing non-ideal, non-homogenous and absorbing dielectric. The analysed models are connected with housing constructions and include single and double-layered walls made of clay hollow bricks. The influence of the size of holes, the contained clay mass percentage and conductivity of brick on the distribution of electric field is presented. Double-layered wall causes more heterogeneity in distribution of electric field and numerous maxima and minima to compare with singlelayered construction. The presented results refer to the electromagnetic field generated by a wireless communication system (Wi-Fi, operating within the standard frequencies (2.4 GHz and 5 GHz. A FDTD method was used to the analysis of electric field distribution. Also in this paper all formulations of difference method (FDTD is presented. The possibilities of modifying the described method are indicated too. The obtained values of electric field intensity allow to determining the attenuation coefficient for different variants of the walls. Detailed analysis of influence of different types of building construction will make it possible to better understand the wave phenomena and counteract local fading at planning of wireless networks systems.

  1. Comparison of PSA value at last follow-up of patients who underwent low-dose rate brachytherapy and intensity-modulated radiation therapy for prostate cancer.

    Science.gov (United States)

    Tanaka, Nobumichi; Asakawa, Isao; Nakai, Yasushi; Miyake, Makito; Anai, Satoshi; Fujii, Tomomi; Hasegawa, Masatoshi; Konishi, Noboru; Fujimoto, Kiyohide

    2017-08-25

    To compare the PSA value at the last follow-up of patients who underwent prostate low-dose rate brachytherapy (LDR-BT) with that of patients who underwent intensity-modulated radiation therapy (IMRT). A total of 610 prostate cancer patients (cT1c-3bN0M0) were enrolled, and 445 of them underwent LDR-BT, while 165 received IMRT (74-76 Gy). The median follow-up period of these two groups was 75 months (LDR-BT) and 78 months (IMRT), respectively. We also evaluated the biochemical recurrence (BCR)-free rate using two definitions (Phoenix definition and PSA ≥ 0.2 ng/mL). The percentage of patients who achieved PSA LDR-BT group and 49.7% in the IMRT group (p LDR-BT group and 32.1% in the IMRT group (p LDR-BT groups was 89.5 and 95.0% (p LDR-BT groups, respectively (p LDR-BT was significantly lower than that of IMRT, and this result was particularly marked in patients with a normal testosterone level at the last follow-up.

  2. Influence of the crack propagation rate in the obtaining opening and closing stress intensity factor by finite element method

    Directory of Open Access Journals (Sweden)

    Luiz Carlos H. Ricardo

    2016-03-01

    Full Text Available Crack propagation simulation began with the development of the finite element method; the analyses were conducted to obtain a basic understanding of the crack growth. Today structural and materials engineers develop structures and materials properties using this technique as criterion design. The aim of this paper is to verify the effect of different crack propagation rates in determination of crack opening and closing stress of an ASTM specimen under a standard suspension spectrum loading from FD&E SAE Keyhole Specimen Test Load Histories by finite element analysis. The crack propagation simulation was based on release nodes at the minimum loads to minimize convergence problems. To understand the crack propagation processes under variable amplitude loading, retardation effects are discussed.

  3. Effects of High-Intensity Swimming on Lung Inflammation and Oxidative Stress in a Murine Model of DEP-Induced Injury.

    Directory of Open Access Journals (Sweden)

    Leonardo C M Ávila

    Full Text Available Studies have reported that exposure to diesel exhaust particles (DEPs induces lung inflammation and increases oxidative stress, and both effects are susceptible to changes via regular aerobic exercise in rehabilitation programs. However, the effects of exercise on lungs exposed to DEP after the cessation of exercise are not clear. Therefore, the aim of this study was to evaluate the effects of high-intensity swimming on lung inflammation and oxidative stress in mice exposed to DEP concomitantly and after exercise cessation. Male Swiss mice were divided into 4 groups: Control (n = 12, Swimming (30 min/day (n = 8, DEP (3 mg/mL-10 μL/mouse (n = 9 and DEP+Swimming (n = 8. The high-intensity swimming was characterized by an increase in blood lactate levels greater than 1 mmoL/L between 10th and 30th minutes of exercise. Twenty-four hours after the final exposure to DEP, the anesthetized mice were euthanized, and we counted the number of total and differential inflammatory cells in the bronchoalveolar fluid (BALF, measured the lung homogenate levels of IL-1β, TNF-α, IL-6, INF-ϫ, IL-10, and IL-1ra using ELISA, and measured the levels of glutathione, non-protein thiols (GSH-t and NPSH and the antioxidant enzymes catalase and glutathione peroxidase (GPx in the lung. Swimming sessions decreased the number of total cells (p<0.001, neutrophils and lymphocytes (p<0.001; p<0.05 in the BALF, as well as lung levels of IL-1β (p = 0.002, TNF-α (p = 0.003, IL-6 (p = 0.0001 and IFN-ϫ (p = 0.0001. However, the levels of IL-10 (p = 0.01 and IL-1ra (p = 0.0002 increased in the swimming groups compared with the control groups, as did the CAT lung levels (p = 0.0001. Simultaneously, swimming resulted in an increase in the GSH-t and NPSH lung levels in the DEP group (p = 0.0001 and p<0.002. We concluded that in this experimental model, the high-intensity swimming sessions decreased the lung inflammation and oxidative stress status during DEP-induced lung

  4. MRI-detected skull-base invasion. Prognostic value and therapeutic implication in intensity-modulated radiotherapy treatment for nasopharyngeal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Yi-Kan; Jiang, Ning; Yue, Dan; Tang, Ling-Long; Zhang, Fan; Lin, Li; Liu, Xu; Chen, Lei; Ma, Jun [Sun Yat-sen University Cancer Center, Department of Radiation Oncology, Guangzhou (China); Liu, Li-Zhi [Sun Yat-sen University Cancer Center, Department of Radiology, Guangzhou (China)

    2014-10-15

    With advances in imaging and radiotherapy, the prognostic value of skull-base invasion in nasopharyngeal carcinoma (NPC) needs to be reassessed. We aimed to define a classification system and evaluate the prognostic value of the classification of magnetic resonance imaging (MRI)-detected skull-base invasion in NPC treated with intensity-modulated radiotherapy (IMRT). We retrospectively reviewed 749 patients who underwent MRI and were subsequently histologically diagnosed with nondisseminated NPC and treated with IMRT. MRI-detected skull-base invasion was not found to be an independent prognostic factor for overall survival (OS), distant metastasis-free survival (DMFS), local relapse-free survival (LRFS), or disease-free survival (DFS; p > 0.05 for all). Skull-base invasion was classified according to the incidence of each site (type I sites inside pharyngobasilar fascia and clivus vs. type II sites outside pharyngobasilar fascia). The 5-year OS, DMFS, LRFS, and DFS rates in the classification of skull-base invasion in NPC were 83 vs. 67 %, 85 vs.75 %, 95 vs. 88 %, and 76 vs. 62 %, respectively (p < 0.05 for all). Multivariate analysis indicated the classification of skull-base invasion was an independent prognostic factor. MRI-detected skull-base invasion is not an independent prognostic factor in patients with NPC treated with IMRT. However, classification according to the site of invasion has prognostic value. Therefore, patients with various subclassifications of stage T3 disease may receive treatment with different intensities; however, further studies are warranted to prove this. (orig.) [German] Aufgrund der Fortschritte der bildgebenden Verfahren und der Strahlentherapie muss der prognostische Wert der Invasion des nasopharyngealen Karzinoms (NPC) in die Schaedelbasis erneut bewertet werden. Unser Ziel ist die Definition eines Klassifikationssystems und die Untersuchung des prognostischen Werts der Klassifikation der MRT-ermittelten Invasion des mit

  5. Effects of cold working ratio and stress intensity factor on intergranular stress corrosion cracking susceptibility of non-sensitized austenitic stainless steels in simulated BWR and PWR primary water

    International Nuclear Information System (INIS)

    Yaguchi, Seiji; Yonezawa, Toshio

    2012-01-01

    To evaluate the effects of cold working ratio, stress intensity factor and water chemistry on an IGSCC susceptibility of non-sensitized austenitic stainless steel, constant displacement DCB specimens were applied to SCC tests in simulated BWR and PWR primary water for the three types of austenitic stainless steels, Types 316L, 347 and 321. IGSCC was observed on the test specimens in simulated BWR and PWR primary water. The observed IGSCC was categorized into the following two types. The one is that the IGSCC observed on the same plane of the pre-fatigue crack plane, and the other is that the IGSCC observed on a plane perpendicular to the pre-fatigue crack plane. The later IGSCC fractured plane is parallel to the rolling plane of a cold rolled material. Two types of IGSCC fractured planes were changed according to the combination of the testing conditions (cold working ratio, stress intensity factor and simulated water). It seems to suggest that the most susceptible plane due to fabrication process of materials might play a significant role of IGSCC for non-sensitized cold worked austenitic stainless steels, especially, in simulated PWR primary water. Based upon evaluating on the reference crack growth rate (R-CGR) of the test specimens, the R-CGR seems to be mainly affected by cold working ratio. In case of simulated PWR primary water, it seems that the effect of metallurgical aspects dominates IGSCC susceptibility. (author)

  6. Prediction of wall motion improvement after coronary revascularization in patients with postmyocardial infarction. Diagnostic value of dobutamine stress echocardiography and myocardial contrast echocardiography

    International Nuclear Information System (INIS)

    Waku, Sachiko; Ohkubo, Tomoyuki; Takada, Kiyoshi; Ishihara, Tadashi; Ohsawa, Nakaaki; Adachi, Itaru; Narabayashi, Isamu

    1997-01-01

    The diagnostic value of dobutamine stress echocardiography, myocardial contrast echocardiography and dipyridamole stress thallium-201 single photon emission computed tomography (SPECT) for predicting recovery of wall motion abnormality after revascularization was evaluated in 13 patients with postmyocardial infarction. Seventeen segments showed severe wall motion abnormalities before revascularization. Nine segments which had relatively good Tl uptake on delayed SPECT images despite severely abnormal wall motion were opacified during myocardial contrast echocardiography, and showed improved wall motion after revascularization. In contrast, three segments which had poor Tl uptake and severely abnormal wall motion were not opacified during myocardial contrast echocardiography, and showed no improvement in wall motion during dobutamine stress echocardiography and after revascularization. The following three findings were assumed to be signs of myocardial viability: good Tl uptake on delayed SPECT images, improved wall motion by dobutamine stress echocardiography, and positive opacification of the myocardium by myocardiai contrast echocardiography. Myocardial contrast echocardiography had the highest sensitivity (100%) and negative predictive value (100%). Delayed SPECT images had the highest specificity (100%) and positive predictive value (100%). Dobutamine stress echocardiography had a sensitivity of 83.0%, specificity of 80.0%, positive predictive value of 90.9%, and negative predictive value of 66.7%, respectively. Myocardial contrast echocardiography showed the lowest specificity (60.0%). The techniques of dobutamine stress echocardiography and SPECT, though noninvasive, may underestimate wall motion improvement after revascularization. Further examination by myocardial contrast echocardiography is recommended to assess myocardial viability for determining the indications for coronary revascularization in spite of its invasiveness. (author)

  7. Stress !!!

    NARCIS (Netherlands)

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten.

  8. Determining the Threshold Value of Basil Yield Reduction and Evaluation of Water Uptake Models under Salinity Stress Condition

    Directory of Open Access Journals (Sweden)

    M. Sarai Tabrizi

    2016-10-01

    Full Text Available Introduction: Several mathematical models are being used for assessing the plant response to the salinity of the root zone. The salinity of the soil and water resources is a major challenge for agricultural sector in Iran. Several mathematical models have been developed for plant responses to the salinity stress. However, these models are often applicable in particular conditions. The objectives of this study were to evaluate the threshold value of Basil yield reduction, modeling Basil response to salinity and to evaluate the effectiveness of available mathematical models for the yield estimation of the Basil . Materials and Methods: The extensive experiments were conducted with 13 natural saline water treatments including 1.2, 1.8, 2, 2.2, 2.5, 2.8, 3, 3.5, 4, 5, 6, 8, and 10 dSm-1. Water salinity treatments were prepared by mixing Shoor River water with fresh water. In order to quantify the salinity effect on Basil yield, seven mathematical models including Maas and Hoffman (1977, van Genuchten and Hoffman (1984, Dirksen and Augustijn (1988, and Homaee et al., (2002 were used. One of the relatively recent methods for soil water content measurements is theta probes instrument. Theta probes instrument consists of four probes with 60 mm long and 3 mm diameter, a water proof container (probe structure, and a cable that links input and output signals to the data logger display. The advantages that have been attributed to this method are high precision and direct and rapid measurements in the field and greenhouse. The range of measurements is not limited like tensiometer and is from saturation to wilting point. In this study, Theta probes instrument was calibrated by weighing method for exact irrigation scheduling. Relative transpiration was calculated using daily soil water content changes. A coarse sand layer with 2 centimeters thick was used to decrease evaporation from the surface soil of the pots. Quantity comparison of the used models was done

  9. Vacuum expectation value of the stress-energy tensor of a 2D-gravity field and loop amplitudes for strings of noncritical dimensions

    International Nuclear Information System (INIS)

    Danilov, G.S.

    1995-01-01

    It is shown that, in the theory of free noncritical strings, there are no modular-invariant partition functions on surfaces of higher genus. This is due to the fact that the vacuum expectation value of the stress-energy tensor is singular in the fundamental region on the complex plane in which Riemann surfaces are mapped. The above singularity is associated with a nonzero vacuum expectation value of the 2D-gravity field. 15 refs

  10. Current state of low-cycle fatigue research based on multiaxial stress intensity and its challenges. Part 1. Focusing on low-cycle fatigue strength evaluation method of elbow piping subjected to in-plane cyclic bending displacement load

    International Nuclear Information System (INIS)

    Urabe, Yoshio

    2017-01-01

    The R and D of fatigue strength at multiaxial stress intensity is recognized to become extremely important in the future in terms of the elaboration of low-cycle fatigue evaluation of various structures including piping systems and reflection on those standards. This paper focuses on the evaluation method developed by the author, namely cumulative damage rule in consideration of multiaxial stress intensity, and explains the concept and the results of verification and evaluation. It also discusses the engineering problems of the current low cycle fatigue assessment technology that were clarified in the process of developing low-cycle fatigue assessment method based on multiaxial stress intensity. The conservative lifespan and somewhat more conservative actual lifetime of elbow piping can be estimated by the conventional 'revised universal slope method' and 'advanced revised universal slope method.' However, these are empirical rules, and the theoretical basis is not clear. From 'cumulative damage rule in consideration of multiaxial stress intensity,' the author calculated furthermore 'low cycle fatigue evaluation formula based on cumulative damage rule in consideration of multi-axial stress intensity,' and examined it. As a result, an evaluation formula that can reasonably assume the equivalent thermoplastic strain range could be obtained at half of the repeat count as targeted. Furthermore, at the stage where future high precision FEM analysis can be used, direct low-cycle fatigue life curve can be established. (A.O.)

  11. A new plastic correction for the stress intensity factor of an under-clad defect in a PWR vessel subjected to a pressurised thermal shock

    International Nuclear Information System (INIS)

    Marie, S.; Nedelec, M.

    2007-01-01

    For the assessment of an under-clad defect in a vessel subjected to a cold pressurised thermal shock, plasticity is considered through the amplification β of the elastic stress intensity factor K I in the ferritic part of the vessel. An important effort has been made recently by CEA to improve the analytical tools in the frame of R and D activities funded by IRSN. The current solution in the French RSE-M code has been developed from fitted F.E. calculation results. A more physical solution is proposed in this paper. This takes into account two phenomena: the amplification of the elastic K I due to plasticity in the cladding and a plastic zone size correction in the ferritic part. The first correction has been established by representing the cladding plasticity by an imposed displacement on the crack faces at the interface between the cladding and the ferritic vessel. The corresponding elastic stress intensity factor is determined from the elastic plane strain asymptotic solution for the opening displacement. Plasticity in the ferritic steel is considered through a classical plastic zone size correction. The application of the solution to axisymmetric defects is first checked. The case of semi-elliptical defects is also investigated. For the correction determined at the interface between the cladding and the ferritic vessel, an amplification of the correction proposed for the deepest point is determined from a fitting of the 3D F.E. calculation results. It is also shown that the proposition of RSE-M, which consists in applying the same β correction at the deepest point and the interface point is not suitable. The applicability to a thermal shock, eventually combined with an internal pressure has been verified. For the deepest point, the proposed correction leads to similar results to the RSE-M method, but presents an extended domain of validity (no limits on the crack length are imposed)

  12. EFFECT OF THE PRODUCTION SEASON ON NUTRITIONAL VALUE AND TECHNOLOGICAL SUITABILITY OF MILK OBTAINED FROM INTENSIVE (TMR AND TRADITIONAL FEEDING SYSTEM OF COWS

    Directory of Open Access Journals (Sweden)

    Aneta Brodziak

    2012-04-01

    Full Text Available The seasonal variations in milk yield and its chemical composition arise mainly from changes in feeding of the cattle in different seasons of the year. A constant quantity of production and a similar quality of the raw material supply farms, where the feeding of cows is uniform throughout the year (TMR and PMR. The study included 1211 samples of milk obtained in the summer season (663 and in the winter season (548 from cows maintained in traditional and intensive (TMR system of production. Following parameters were determined: content of fat, protein, casein, lactose and dry matter; acidity (pH value; heat stability; rennet coagulation time; content of α-lactalbumin, β-lactoglobulin, bovine serum albumin, lactoferrin, lysozyme and fatty acid profiles. Cows fed in the TMR system produced significantly (P≤0.01 more milk and of a better chemical composition regardless of the season of production. Milk obtained from cows fed traditionally had the most profitable protein to fat ratio (0,90 and the shortest time of rennet coagulation (3:26 min. It contained significantly (P≤0.01 more whey proteins and had better fatty acid profiles for health. In addition the differences were usually larger in the summer season than in the winter season. It is possible to state that in summer season, when the animals are maintained on the pasture, milk obtained from cows fed traditionally is more suitable for processing and contains more biologically active substances. The daily milk yield and other important quality features of milk, significant interactions between season of production and system of feeding were revealed.

  13. Predictive value of the time-intensity curves on dynamic contrast-enhanced magnetic resonance imaging for lymphatic spreading in breast cancer

    International Nuclear Information System (INIS)

    Komatsu, Shuhei; Lee, Chol Joo; Ichikawa, Daisuke

    2005-01-01

    Dynamic contrast-enhanced magnetic resonance imaging (CE-MRI) has emerged as a promising diagnostic modality in various breast cancer treatments. However, little is known about the correlation between the pattern of time to signal intensity curves (TIC) on the CE-MRI and clinicopathologic features. This study was designed to investigate these correlations and evaluate the predictive value of TIC on CE-MRI in order to identify high-risk patients. Between 2001 and 2003, 101 lesions were evaluated to detect malignancy on CE-MRI in 101 women who were suspected of having breast tumors based on either clinical findings or conventional imaging studies. Moreover, the clinicopathologic findings were compared with the pattern of TIC for the 69 surgically treated malignant lesions. In detecting malignancy, the sensitivity, specificity, and accuracy were 78.7%, 88.5%, and 81.2%, respectively, in the 101 breast lesions. Especially for the 69 surgically treated malignant lesions, in comparison with breast cancer tumors with the benign pattern of TIC, the breast cancer tumors with a malignant pattern were found more frequently in lymphatic invasion (P<0.01) and lymph node metastasis (P<0.005), although no statistical correlation regarding the histological type, tumor size, vascular invasion, extensive intraductal component, hormone receptor status, or pathological stage was noted between the two groups. According to a logistic regression model, lymph node metastasis was found to be a significant independent variable. The pattern of TIC could be used to predict lymphatic spreading associated with lymph node metastasis prior to surgery as well as to detect malignancy. Therefore, a more detailed evaluation should be made to identify the presence of lymphatic spreading in patients with a malignant pattern of TIC. (author)

  14. The predictive value of demonstrable stress incontinence during basic office evaluation and urodynamics in women without symptomatic urinary incontinence undergoing vaginal prolapse surgery

    NARCIS (Netherlands)

    van der Ploeg, J. Marinus; Zwolsman, Sandra E.; Posthuma, Selina; Wiarda, Hylco S.; van der Vaart, C. Huub; Roovers, Jan-Paul W. R.

    2017-01-01

    Women with pelvic organ prolapse without symptoms of urinary incontinence (UI) might demonstrate stress urinary incontinence (SUI) with or without prolapse reduction. We aimed to determine the value of demonstrable SUI during basic office evaluation or urodynamics in predicting SUI after vaginal

  15. Correlates of improvement in substance abuse among dually diagnosed veterans with post-traumatic stress disorder in specialized intensive VA treatment.

    Science.gov (United States)

    Coker, Kendell L; Stefanovics, Elina; Rosenheck, Robert

    2016-01-01

    Substantial rates of substance use comorbidity have been observed among veterans with Post-Traumatic Stress Disorder (PTSD), highlighting the need to identify patient and program characteristics associated with improved outcomes for substance abuse. Data were drawn from 12,270 dually diagnosed veterans who sought treatment from specialized intensive Veterans Health Administration PTSD programs between 1993 and 2011. The magnitude of the improvement in Addiction Severity Index (ASI) alcohol and drug use composite scores from baseline was moderate, with effect sizes (ES) of -.269 and -.287, respectively. Multivariate analyses revealed that treatment in longer-term programs, being prescribed psychiatric medication, and planned participation in reunions were all associated with slightly improved outcomes. Reductions in substance use measures were associated with robust improvements in PTSD symptoms and violent behavior. These findings suggest not only synergistic treatment effects linking improvement in PTSD symptoms with substance use disorders among dually diagnosed veterans with PTSD, but also to reductions in violent behavior. Furthermore, the findings indicate that proper discharge planning in addition to intensity and duration of treatment for dually diagnosed veterans with severe PTSD may result in better outcomes. Further dissemination of evidence-based substance abuse treatment may benefit this population. (c) 2016 APA, all rights reserved).

  16. Low intensity shear stress increases endothelial ELR+ CXC chemokine production via a focal adhesion kinase-p38{beta} MAPK-NF-{kappa}B pathway.

    Science.gov (United States)

    Shaik, Sadiq S; Soltau, Thomas D; Chaturvedi, Gaurav; Totapally, Balagangadhar; Hagood, James S; Andrews, William W; Athar, Mohammad; Voitenok, Nikolai N; Killingsworth, Cheryl R; Patel, Rakesh P; Fallon, Michael B; Maheshwari, Akhil

    2009-02-27

    CXC chemokines with a glutamate-leucine-arginine (ELR) tripeptide motif (ELR(+) CXC chemokines) play an important role in leukocyte trafficking into the tissues. For reasons that are not well elucidated, circulating leukocytes are recruited into the tissues mainly in small vessels such as capillaries and venules. Because ELR(+) CXC chemokines are important mediators of endothelial-leukocyte interaction, we compared chemokine expression by microvascular and aortic endothelium to investigate whether differences in chemokine expression by various endothelial types could, at least partially, explain the microvascular localization of endothelial-leukocyte interaction. Both in vitro and in vivo models indicate that ELR(+) CXC chemokine expression is higher in microvascular endothelium than in aortic endothelial cells. These differences can be explained on the basis of the preferential activation of endothelial chemokine production by low intensity shear stress. Low shear activated endothelial ELR(+) CXC chemokine production via cell surface heparan sulfates, beta(3)-integrins, focal adhesion kinase, the mitogen-activated protein kinase p38beta, mitogen- and stress-associated protein kinase-1, and the transcription factor.

  17. The Effects of Kangaroo Care in the Neonatal Intensive Care Unit on the Physiological Functions of Preterm Infants, Maternal-Infant Attachment, and Maternal Stress.

    Science.gov (United States)

    Cho, Eun-Sook; Kim, Shin-Jeong; Kwon, Myung Soon; Cho, Haeryun; Kim, Eun Hye; Jun, Eun Mi; Lee, Sunhee

    2016-01-01

    This study was conducted to identify the effects of kangaroo care on the physiological functions of preterm infants, maternal-infant attachment, and maternal stress. For this study, a quasi-experiment design was used with a nonequivalent control group, and a pre- and post-test. Data were collected from preterm infants with corrected gestational ages of ≥33weeks who were hospitalized between May and October 2011. Twenty infants were assigned to the experimental group and 20 to the control group. As an intervention, kangaroo care was provided in 30-min sessions conducted thrice a week for a total of 10 times. The collected data were analyzed by using the t test, repeated-measures ANOVA, and the ANCOVA test. After kangaroo care, the respiration rate significantly differed between the two groups (F=5.701, p=.020). The experimental group had higher maternal-infant attachment scores (F=25.881, pinfant physiological functions such as respiration rate, increasing maternal-infant attachment, and reducing maternal stress. This study suggests that kangaroo care can be used to promote emotional bonding and support between mothers and their babies, and to stabilize the physiological functions of premature babies. Kangaroo care may be one of the most effective nursing interventions in the neonatal intensive care unit for the care of preterm infants and their mothers. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Acute effects of resistance exercise and intermittent intense aerobic exercise on blood cell count and oxidative stress in trained middle-aged women.

    Science.gov (United States)

    Cardoso, A M; Bagatini, M D; Roth, M A; Martins, C C; Rezer, J F P; Mello, F F; Lopes, L F D; Morsch, V M; Schetinger, M R C

    2012-12-01

    The aim of this study was to compare the effect of an intermittent intense aerobic exercise session and a resistance exercise session on blood cell counts and oxidative stress parameters in middle-aged women. Thirty-four women were selected and divided into three groups: RE group (performing 60 min of resistance exercises, N = 12), spinning group (performing 60 min of spinning, N = 12), and control group (not exercising regularly, N = 10). In both exercise groups, lymphocytes and monocytes decreased after 1-h recuperation (post-exercise) compared to immediately after exercise (P exercise, in both exercised groups, a significant increase in TBARS (from 16.5 ± 2 to 25 ± 2 for the spinning group and from 18.6 ± 1 to 28.2 ± 3 nmol MDA/mL serum for the RE group) and protein carbonyl (from 1.0 ± 0.3 to 1.6 ± 0.2 for the spinning group and from 0.9 ± 0.2 to 1.5 ± 0.2 nmol/mg protein for the RE group) was observed (P exercise induces immune suppression and increases the production of reactive oxygen species, causing oxidative stress in middle-aged and trained women. Furthermore, we demonstrated that trained women show improved antioxidant capacity and lower oxidative damage than sedentary ones, demonstrating the benefits of chronic regular physical activity.

  19. Influence of Mild Traumatic Brain Injury (TBI) and Posttraumatic Stress Disorder (PTSD) on Pain Intensity Levels in OEF/OIF/OND Veterans.

    Science.gov (United States)

    Stojanovic, Milan P; Fonda, Jennifer; Fortier, Catherine Brawn; Higgins, Diana M; Rudolph, James L; Milberg, William P; McGlinchey, Regina E

    2016-11-01

    Mild traumatic brain injury (mTBI) and posttraumatic stress disorder (PTSD) are common among US veterans of Operation Enduring Freedom/Operation Iraqi Freedom/Operation New Dawn (OEF/OIF/OND). We postulated that these injuries may modulate pain processing in these individuals and affect their subjective pain levels. Cross-sectional. 310 deployed service members of OEF/OIF/OND without a lifetime history of moderate or severe TBI were included in this study. All participants completed a comprehensive evaluation for Blast Exposure, mTBI, PTSD, and Pain Levels. The Boston Assessment of TBI-Lifetime Version (BAT-L) was used to assess blast exposure and potential brain injury during military service. The Clinician-Administered PTSD Scale (CAPS) characterized presence and severity of PTSD. The Visual Analog Scale (VAS) was used to assess pain intensity over the previous month before the interview, with higher scores indicative of worse pain. Statistical analysis was performed by ANOVA and results were adjusted for co-morbidities, clinical characteristics and demographic data. In comparison to control participants (veterans without mTBI or current PTSD), veterans with both current PTSD and mTBI reported the highest pain intensity levels, followed by veterans with PTSD only (P Pain levels in veterans with mTBI only were comparable to control participants. Comorbid PTSD and mTBI is associated with increased self-reported pain intensity. mTBI alone was not associated with increased pain. Published by Oxford University Press on behalf of the American Academy of Pain Medicine 2016. This work is written by US Government employees and is in the public domain in the US.

  20. High-intensity interval training beneficial effects on body mass, blood pressure, and oxidative stress in diet-induced obesity in ovariectomized mice.

    Science.gov (United States)

    Pimenta, Marcel; Bringhenti, Isabele; Souza-Mello, Vanessa; Dos Santos Mendes, Iara Karise; Aguila, Marcia B; Mandarim-de-Lacerda, Carlos A

    2015-10-15

    To investigate the possible beneficial effect of high-intensity interval training (HIIT) on skeletal muscle oxidative stress, body mass (BM) and systolic blood pressure (SBP) in ovariectomized mice fed or not fed a high-fat diet. Three-month-old female C57BL/6 mice were bilaterally ovariectomized (OVX group) or submitted to surgical stress without ovariectomy (SHAM group) and separated into standard chow (SHAM-SC; OVX-SC) and high-fat diet (SHAM-HF; OVX-HF) groups. After 13 weeks, an HIIT program (swimming) was carried out for 8 weeks in non-trained (NT) and trained (T) groups. The significant reduction of uterine mass and the cytological examination of vaginal smears in the OVX group confirmed that ovariectomy was successful. Before the HIIT protocol, the ovariectomized groups showed a greater BM than the SHAM group, irrespective of the diet they received. The HIIT minimized BM gain in animals fed an HF diet and/or ovariectomized. SBP and total cholesterol were increased in the OVX and HF animals compared to their counterparts, and the HIIT efficiently reduced these factors. In the HF and OVX mice, the muscular superoxide dismutase and catalase levels were low while their glutathione peroxidase and glutathione reductase levels were high and the HIIT normalized these parameters. Diet-induced obesity maximizes the deleterious effects of an ovariectomy. The HIIT protocol significantly reduced BM, SBP and oxidative stress in the skeletal muscle indicating that HIIT diminishes the cardiovascular and metabolic risk that is inherent to obesity and menopause. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Transtorno de estresse pós-traumático em pacientes de unidade de terapia intensiva Post-traumatic stress disorder in intensive care unit patients

    Directory of Open Access Journals (Sweden)

    Andrea Vannini Santesso Caiuby

    2010-03-01

    Full Text Available O transtorno de estresse pós-traumático tem sido descrito em pacientes após tratamento em unidade de terapia intensiva. O objetivo foi revisar estudos sobre os aspectos psicológicos e as intervenções terapêuticas destes pacientes após internação em unidade de terapia intensiva. Trinta e oito artigos foram incluídos. A prevalência de transtorno de estresse pós-traumático variou de 17% a 30% e a incidência de 14% a 24%. Os fatores de risco foram: história prévia de ansiedade, depressão ou pânico, ter memórias traumáticas ilusórias (memórias derivadas de formações psíquicas como sonho e delirium, tempo de ventilação mecânica, experiências estressantes, crenças e comportamentos de característica depressiva. Doses altas de opióides, sintomas na retirada da sedação ou analgesia e o uso de lorazepam foram relacionados ao aumento de delirium e de memória ilusória. A sintomatologia do transtorno pode ser reduzida com a administração de hidrocortisona, com a interrupção diária da sedação e não foram encontrados estudos de efetividade de intervenção psicológica.Post-traumatic stress disorder has been detected in patients after treatment in intensive care unit. The main goal of this study is to review the psychological aspects and therapeutic interventions on those patients after their treatment on intensive care unit. Thirty eight articles have been included. The prevalence of post-traumatic stress disorder has varied from 17% up to 30% and the incidence from 14% to 24%. The risk factors were: previous anxiety historic, depression or panic, having delusional traumatic memories (derived from psychic formations as dreams and delirium, belief effects, depressive behavior, stressing experiences and mechanical ventilation. High doses of opiates, symptoms caused by sedation or analgesia reduction and the use of lorazepam were related with the increase of delirium and delusional memory. The disorder sintomatology

  2. A study of an influence of a fiber arrangement of a laminate ply on the distribution and values of stresses in the multi-layered composite material

    Directory of Open Access Journals (Sweden)

    Herbuś Krzysztof

    2017-01-01

    Full Text Available In the work are presented studies related with the influence of a fiber arrangement of a laminate ply on the distribution and values of stresses in the multi-layered composite material. For this purpose, the characteristics of the three-point bending test, according to the standard PN-EN ISO 7438, of specimens made from the composite material, where a single ply is a composition of epoxy resin and glass fibres, was mapped. The modelling process of the multi-layered composite material and its strength verification was performed in the PLM Siemens NX system. Based on the results of performed numerical studies, the relation between the value of the main angle of an arrangement of fibers in each plies of the laminate, and the distribution and values of stresses, occurring in the examined specimens has been determined.

  3. Most oxidative stress response in water samples comes from unknown chemicals: the need for effect-based water quality trigger values.

    Science.gov (United States)

    Escher, Beate I; van Daele, Charlotte; Dutt, Mriga; Tang, Janet Y M; Altenburger, Rolf

    2013-07-02

    The induction of adaptive stress response pathways is an early and sensitive indicator of the presence of chemical and non-chemical stressors in cells. An important stress response is the Nrf-2 mediated oxidative stress response pathway where electrophilic chemicals or chemicals that cause the formation of reactive oxygen species initiate the production of antioxidants and metabolic detoxification enzymes. The AREc32 cell line is sensitive to chemicals inducing oxidative stress and has been previously applied for water quality monitoring of organic micropollutants and disinfection byproducts. Here we propose an algorithm for the derivation of effect-based water quality trigger values for this end point that is based on the combined effects of mixtures of regulated chemicals. Mixture experiments agreed with predictions by the mixture toxicity concept of concentration addition. The responses in the AREc32 and the concentrations of 269 individual chemicals were quantified in nine environmental samples, ranging from treated effluent, recycled water, stormwater to drinking water. The effects of the detected chemicals could explain less than 0.1% of the observed induction of the oxidative stress response in the sample, affirming the need to use effect-based trigger values that account for all chemicals present.

  4. Ultimate pH values and bacteriological condition of meat and stress metabolites in blood of transported reindeer bulls

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    E. Wiklund

    2001-03-01

    Full Text Available Twenty-three reindeer bulls, aged 2-3 years, fed during two winter months at the Vuolda reindeer research station in Arjeplog, Sweden, were used in the study. The first group of eight reindeer was moved from their feeding corral to a selection corral, captured by lasso and stunned with a captive bolt outside the selection corral. The second group of seven reindeer was moved to the selection corral, captured by lasso and restrained, after which they were loaded onto a lorry- and transported for 1 hour and then slaughtered. The third group of eight reindeer was moved to the selection corral and herded directly onto the lorry, without any manual handling. They were transported for 5 h and then slaughtered. In both transport groups, four reindeer were fitted with pre-programmed automatic blood sampling equipment (ABSE. ABSE sampled blood at predetermined times via a jugular vein catheter. Ultimate pH-values in three muscles (Mm. longissimus, triceps brachii and biceps femoris were significantly lower in the group carefully handled and transported for 5 h compared with the other two groups. The physiological mechanisms behind these results are discussed. Samples from M. semimembranosus were collected at slaughter and after 2, 6 and 10 days of refrigerated storage (+4 °C. The samples were analysed for total counts of aerobic bacteria (pour-plated in Tryptone Glucose Extract Agar, Difco, incubated at 20 °C and 30 °C, respectively for 72 h, coliform bacteria 37 °C (pour-plated in Violet Red Bile Agar, Oxoid, incubated at 37 °C for 24 h, Enterococci (surface-plated onto Slantez and Bartley Agar, Oxoid, incubated at 44 °C for 48 h and Bacillus cereus (surface-plated onto Blood Agar Plates (Blood Agar Base, Difco, supplemented with 5% defibrinated horse blood 30 °C for 24 h. All samples fell in the range 'fit for consumption'. At slaughter, there was no difference in ASAT activity, urea and Cortisol concentrations between the two transported groups

  5. Prognostic value of KRAS genotype in metastatic colorectal cancer (MCRC patients treated with intensive triplet chemotherapy plus bevacizumab (FIr-B/FOx according to extension of metastatic disease

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    Bruera Gemma

    2012-11-01

    Full Text Available Abstract Background Bevacizumab (BEV plus triplet chemotherapy can increase efficacy of first-line treatment of metastatic colorectal cancer (MCRC, particularly integrated with secondary liver surgery in liver-limited (L-L patients. The prognostic value of the KRAS genotype in L-L and other or multiple metastatic (O/MM MCRC patients treated with the FIr-B/FOx regimen was retrospectively evaluated. Methods Tumoral and metastatic samples were screened for KRAS codon 12 and 13 and BRAF mutations by SNaPshot and/or direct sequencing. Fit MCRC patients 2, days 1, 2, 8, 9, 15, 16, 22 and 23; irinotecan (CPT-11 160 mg/m2 plus BEV 5 mg/kg, days 1, 15; oxaliplatin (OXP 80 mg/m2, days 8, 22; every 4 weeks. MCRC patients were classified as L-L and O/MM. Activity and efficacy were evaluated and compared using log-rank test. Results In all, 59 patients were evaluated: 31 KRAS wild-type (53%, 28 KRAS mutant (47%. At 21.5 months median follow-up, objective response rate (ORR, progression-free survival (PFS and overall survival (OS were, respectively: KRAS wild-type 90%, 14 months, 38 months; KRAS mutant 67%, 11 months, 20 months. PFS and OS were not significantly different. PFS and OS were significantly different in L-L compared to O/MM evaluable patients. In KRAS wild-type patients, clinical outcome of 12 L-L compared to 18 O/MM was significantly different: PFS 21 versus 12 months and OS 47 versus 28 months, respectively. In KRAS mutant patients, the clinical outcome of 13 L-L compared to 14 O/MM was not significantly different: PFS 11 months equivalently and OS 39 versus 19 months, respectively. Conclusions The KRAS genotype wild-type and mutant does not significantly affect different clinical outcomes for MCRC patients treated with the first-line FIr-B/FOx intensive regimen. KRAS wild-type patients with L-L disease may achieve a significantly prolonged clinical outcome due to integration with secondary liver surgery, with respect to KRAS mutant patients.

  6. Stress.

    Science.gov (United States)

    Chambers, David W

    2008-01-01

    We all experience stress as a regular, and sometimes damaging and sometimes useful, part of our daily lives. In our normal ups and downs, we have our share of exhaustion, despondency, and outrage--matched with their corresponding positive moods. But burnout and workaholism are different. They are chronic, dysfunctional, self-reinforcing, life-shortening habits. Dentists, nurses, teachers, ministers, social workers, and entertainers are especially susceptible to burnout; not because they are hard-working professionals (they tend to be), but because they are caring perfectionists who share control for the success of what they do with others and perform under the scrutiny of their colleagues (they tend to). Workaholics are also trapped in self-sealing cycles, but the elements are ever-receding visions of control and using constant activity as a barrier against facing reality. This essay explores the symptoms, mechanisms, causes, and successful coping strategies for burnout and workaholism. It also takes a look at the general stress response on the physiological level and at some of the damage American society inflicts on itself.

  7. Adaptação cultural e validação para a língua portuguesa da Parental Stress Scale: Neonatal Intensive Care Unit (PSS:NICU Adaptación cultural y validación al idioma português del Parental Stress Scale: Neonatal Intensive Care Unit (PSS:NICU Cultural adaptation and validation for the portuguese language of the Parental Stress Scale: Neonatal Intensive Care Unit (PSS:NICU

    Directory of Open Access Journals (Sweden)

    Sandra Regina de Souza

    2012-01-01

    Full Text Available OBJETIVO: Traduzir, realizar a adaptação cultural e validar a escala Parental Stress Scale:Neonatal Intensive Care Unit (PSS:NICU para a língua portuguesa. MÉTODOS: Utilizou-se o método descritivo de validação de instrumentos de medida, baseado nas etapas propostas por Guillemin et al. A análise da confiabilidade foi realizada por meio dos testes e retestes e da consistência interna. Na validação clínica, participaram 163 pais de recém-nascidos internados em Unidade de Terapia Intensiva Neonatal (UTIN. RESULTADOS: Os coeficientes de correlação intraclasse ficaram em torno de 0,70 mostrando boa estabilidade entre as duas avaliações. A análise fatorial pelo método de componentes principais utilizou os mesmos critérios da escala original, com rotação Varimax, com grau de variância adequado de 57,9%. Os maiores níveis de estresse dos pais foram obtidos na subescala "alteração do papel de pais". CONCLUSÃO: A PSS:NICU na versão em português é uma ferramenta válida e confiável para avaliação do estresse de pais com filho internado na UTIN.OBJETIVO: Traducir, realizar la adaptación cultural y validar la escala Parental Stress Scale:Neonatal Intensive Care Unit (PSS:NICU al idioma portugués. MÉTODOS: Se utilizó el método descriptivo de validación de instrumentos de medida, basado en las etapas propuestas por Guillemin et al. El análisis de la confiabilidad fue realizado por medio de los tests y retests y de la consistencia interna. En la validación clínica, participaron 163 padres de recién nacidos internados en una Unidad de Cuidados Intensivos Neonatal (UCIN. RESULTADOS: Los coeficientes de correlación intraclase quedaron alrededor de 0,70 mostrando buena estabilidad entre las dos evaluaciones El análisis factorial por el método de componentes principales utilizó los mismos criterios de la escala original, con rotación Varimax, con grado de varianza adecuado de 57,9%. Los mayores niveles de estrés de

  8. The value of SPECT in the detection of stress injury to the pars interarticularis in patients with low back pain

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    Grant Frederick D

    2010-03-01

    Full Text Available Abstract The medical cost associated with back pain in the United States is considerable and growing. Although the differential diagnosis of back pain is broad, epidemiological studies suggest a correlation between adult and adolescent complaints. Injury of the pars interarticularis is one of the most common identifiable causes of ongoing low back pain in adolescent athletes. It constitutes a spectrum of disease ranging from bone stress to spondylolysis and spondylolisthesis. Bone stress may be the earliest sign of disease. Repetitive bone stress causes bone remodeling and may result in spondylolysis, a non-displaced fracture of the pars interarticularis. A fracture of the pars interarticularis may ultimately become unstable leading to spondylolisthesis. Results in the literature support the use of bone scintigraphy to diagnose bone stress in patients with suspected spondylolysis. Single photon emission computed tomography (SPECT provides more contrast than planar bone scintigraphy, increases the sensitivity and improves anatomic localization of skeletal lesions without exposing the patient to additional radiation. It also provides an opportunity for better correlation with other imaging modalities, when necessary. As such, the addition of SPECT to standard planar bone scintigraphy can result in a more accurate diagnosis and a better chance for efficient patient care. It is our expectation that by improving our ability to correctly diagnose bone stress in patients with suspected injury of the posterior elements, the long-term cost of managing this condition will be lowered.

  9. Acute effects of resistance exercise and intermittent intense aerobic exercise on blood cell count and oxidative stress in trained middle-aged women

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, A.M. [Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Bagatini, M.D. [Curso de Enfermagem, Campus Chapecó, Universidade Federal da Fronteira Sul, Chapecó, SC (Brazil); Roth, M.A. [Departamento de Desportos Individuais, Centro de Educação Física e Desportos, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Martins, C.C.; Rezer, J.F.P. [Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Mello, F.F. [Departamento de Desportos Individuais, Centro de Educação Física e Desportos, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Lopes, L.F.D. [Departamento de Administração, Centro de Ciências Sociais e Humanas, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Morsch, V.M.; Schetinger, M.R.C. [Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil)

    2012-10-26

    The aim of this study was to compare the effect of an intermittent intense aerobic exercise session and a resistance exercise session on blood cell counts and oxidative stress parameters in middle-aged women. Thirty-four women were selected and divided into three groups: RE group (performing 60 min of resistance exercises, N = 12), spinning group (performing 60 min of spinning, N = 12), and control group (not exercising regularly, N = 10). In both exercise groups, lymphocytes and monocytes decreased after 1-h recuperation (post-exercise) compared to immediately after exercise (P < 0.05). Immediately after exercise, in both exercised groups, a significant increase in TBARS (from 16.5 ± 2 to 25 ± 2 for the spinning group and from 18.6 ± 1 to 28.2 ± 3 nmol MDA/mL serum for the RE group) and protein carbonyl (from 1.0 ± 0.3 to 1.6 ± 0.2 for the spinning group and from 0.9 ± 0.2 to 1.5 ± 0.2 nmol/mg protein for the RE group) was observed (P < 0.05). A decrease in antioxidant activities (non-protein sulfhydryl, superoxide dismutase, catalase) was also demonstrated with a negative correlation between damage markers and antioxidant body defenses (P < 0.05). These results indicate that an acute bout of intermittent or anaerobic exercise induces immune suppression and increases the production of reactive oxygen species, causing oxidative stress in middle-aged and trained women. Furthermore, we demonstrated that trained women show improved antioxidant capacity and lower oxidative damage than sedentary ones, demonstrating the benefits of chronic regular physical activity.

  10. Acute effects of resistance exercise and intermittent intense aerobic exercise on blood cell count and oxidative stress in trained middle-aged women

    Directory of Open Access Journals (Sweden)

    A.M. Cardoso

    2012-12-01

    Full Text Available The aim of this study was to compare the effect of an intermittent intense aerobic exercise session and a resistance exercise session on blood cell counts and oxidative stress parameters in middle-aged women. Thirty-four women were selected and divided into three groups: RE group (performing 60 min of resistance exercises, N = 12, spinning group (performing 60 min of spinning, N = 12, and control group (not exercising regularly, N = 10. In both exercise groups, lymphocytes and monocytes decreased after 1-h recuperation (post-exercise compared to immediately after exercise (P < 0.05. Immediately after exercise, in both exercised groups, a significant increase in TBARS (from 16.5 ± 2 to 25 ± 2 for the spinning group and from 18.6 ± 1 to 28.2 ± 3 nmol MDA/mL serum for the RE group and protein carbonyl (from 1.0 ± 0.3 to 1.6 ± 0.2 for the spinning group and from 0.9 ± 0.2 to 1.5 ± 0.2 nmol/mg protein for the RE group was observed (P < 0.05. A decrease in antioxidant activities (non-protein sulfhydryl, superoxide dismutase, catalase was also demonstrated with a negative correlation between damage markers and antioxidant body defenses (P < 0.05. These results indicate that an acute bout of intermittent or anaerobic exercise induces immune suppression and increases the production of reactive oxygen species, causing oxidative stress in middle-aged and trained women. Furthermore, we demonstrated that trained women show improved antioxidant capacity and lower oxidative damage than sedentary ones, demonstrating the benefits of chronic regular physical activity.

  11. Acute effects of resistance exercise and intermittent intense aerobic exercise on blood cell count and oxidative stress in trained middle-aged women

    International Nuclear Information System (INIS)

    Cardoso, A.M.; Bagatini, M.D.; Roth, M.A.; Martins, C.C.; Rezer, J.F.P.; Mello, F.F.; Lopes, L.F.D.; Morsch, V.M.; Schetinger, M.R.C.

    2012-01-01

    The aim of this study was to compare the effect of an intermittent intense aerobic exercise session and a resistance exercise session on blood cell counts and oxidative stress parameters in middle-aged women. Thirty-four women were selected and divided into three groups: RE group (performing 60 min of resistance exercises, N = 12), spinning group (performing 60 min of spinning, N = 12), and control group (not exercising regularly, N = 10). In both exercise groups, lymphocytes and monocytes decreased after 1-h recuperation (post-exercise) compared to immediately after exercise (P < 0.05). Immediately after exercise, in both exercised groups, a significant increase in TBARS (from 16.5 ± 2 to 25 ± 2 for the spinning group and from 18.6 ± 1 to 28.2 ± 3 nmol MDA/mL serum for the RE group) and protein carbonyl (from 1.0 ± 0.3 to 1.6 ± 0.2 for the spinning group and from 0.9 ± 0.2 to 1.5 ± 0.2 nmol/mg protein for the RE group) was observed (P < 0.05). A decrease in antioxidant activities (non-protein sulfhydryl, superoxide dismutase, catalase) was also demonstrated with a negative correlation between damage markers and antioxidant body defenses (P < 0.05). These results indicate that an acute bout of intermittent or anaerobic exercise induces immune suppression and increases the production of reactive oxygen species, causing oxidative stress in middle-aged and trained women. Furthermore, we demonstrated that trained women show improved antioxidant capacity and lower oxidative damage than sedentary ones, demonstrating the benefits of chronic regular physical activity

  12. Stress mitigation to promote development of prosocial values and school engagement of inner-city urban African American and Latino youth.

    Science.gov (United States)

    Tolan, Patrick; Lovegrove, Peter; Clark, Eren

    2013-01-01

    Studies of predictors of development of young men of color have been primarily focused on factors that impede positive development rather than factors that promote it. There are also few examples of longitudinal studies of positive development of this population and few that consider multiple protective factors simultaneously. Little is also known about how such positive outcomes might relate to prediction of problematic functioning. This study tests a developmental-ecological framework of positive and risky development among a sample of young men of color growing up in high-risk urban environments. African American and Latino adolescent males (148 African American, 193 Latino) were followed from early to late adolescence. Stress in early adolescence was related to school engagement and prosocial values as well as depressive symptoms and problems assessed 2 years later. The role of family and individual protective factors as direct effects and as mitigating the stress-outcome relation were also tested. Stress predicted problem outcomes but not positive functioning. Early engagement in prosocial activities and coping skills did predict positive outcomes. In contrast, problem outcomes were predicted directly by stress, with some indication of interaction with some protective factors for both such outcomes. Overall results suggest value in focusing on positive outcomes along with negative outcomes, as they are not the antithesis and have some shared but some different predictors. Implications for supporting positive development are presented. © 2013 American Orthopsychiatric Association.

  13. Marked lability in urinary cortisol levels in subgroups of combat veterans with posttraumatic stress disorder during an intensive exposure treatment program.

    Science.gov (United States)

    Mason, John W; Wang, Sheila; Yehuda, Rachel; Lubin, Hadar; Johnson, David; Bremner, J Douglas; Charney, Dennis; Southwick, Steven

    2002-01-01

    The objective of this study was to obtain longitudinal data on lability of cortisol levels in posttraumatic stress disorder (PTSD) because previous studies have largely been based on sampling at a single time point and have yielded varying results. This study measured urinary cortisol levels at admission, midcourse, and discharge during a 90-day hospitalization period in male Vietnam combat veterans with PTSD (N = 51). Although there were no significant differences in the mean +/- SEM urinary cortisol levels between the admission (59.4 +/- 3.0 microg/d), midcourse (55.6 +/- 3.9 microg/d), and discharge (53.4 +/- 3.4 microg/d) values, marked lability of cortisol levels in individual patients was observed over time, with changes ranging from +93 to -58 microg/d from admission to midcourse. In addition, this hormonal lability defined discrete subgroups of patients on the basis of the longitudinal pattern of cortisol change during exposure treatment, and there were significant psychometric differences in the level of social functioning between these subgroups. The findings do not support the concept of either a static "hypocortisolism" or "hypercortisolism" in PTSD, but rather suggest a psychogenic basis for cortisol alterations in PTSD in relation to psychosocial stress and indicate a central regulatory dysfunction of the hypothalamic-pituitary-adrenal axis characterized by a dynamic tendency to overreact in both upward and downward directions. The longitudinal findings fit with recent observations that cortisol elevations occur when acutely superimposed stressful conditions emotionally engage patients and overwhelm the usually dominating disengaging coping mechanisms associated with suppression of cortisol levels in PTSD. The findings emphasize the importance of longitudinal data in studies of the hypothalamic-pituitary-adrenal axis in PTSD.

  14. Occurrence of ventilator-associated pneumonia in mechanically ventilated pediatric intensive care patients during stress ulcer prophylaxis with sucralfate, ranitidine, and omeprazole.

    Science.gov (United States)

    Yildizdas, Dincer; Yapicioglu, Hacer; Yilmaz, Hayri Levent

    2002-12-01

    The purpose of the study was to evaluate the effects of sucralfate, ranitidine, and omeprazole use on incidence of ventilatory-associated pneumonia (VAP) and mortality in ventilated pediatric critical care patients. This prospective study was conducted at the pediatric intensive care unit (PICU) between August 2000 and February 2002. A total of 160 patients who needed mechanical ventilation were randomized into 4 groups according to the computer-generated random number table: group (S), (n = 38) received sucralfate suspension 60 mg/kg/d in 4 doses via the nasogastric tube that was flushed with 10 mL of sterile water; group (R), (n = 42) received ranitidine 2 mg/kg/d intravenously in 4 doses; group (O), (n = 38) received omeprazole 1 mg/kg/d intravenously in 2 doses; and group (P), (n = 42) did not receive any medication for stress ulcer prophylaxis. Treatment was begun within 6 hours of PICU admission. Seventy patients (44%) developed VAP. VAP rate was 42% (16 of 38) in the sucralfate group, 48% (20 of 42) in the ranitidine group, 45% (17 of 38) in the omeprazole group, and 41% (17 of 42) in the nontreated group. Overall mortality rate was 22% (35 of 160); it was 21% (8 of 38) in the sucralfate group, 23% (10 of 42) in the ranitidine group, 21% (8 of 38) in the omeprazole group, and 21% (9 of 42) in the nontreated group. Our results did not show any difference in the incidence of VAP and mortality in mechanically ventilated PICU patients treated with ranitidine, omeprazole, or sucralfate, or nontreated subjects (P =.963, confidence interval [CI] = 0.958-0.968; P =.988, CI = 0.985-0.991, respectively). Nine patients (5.6%) had macroscopic bleeding. There was no statistically significant difference in macroscopic bleeding between groups. Our results did not show any difference in the incidence of VAP, macroscopic stress ulcer bleeding, and mortality in the mechanically ventilated PICU patients treated with ranitidine, omeprazole, or sucralfate, or nontreated subjects

  15. The study of treatment value of concurrent chemotherapy for patients with esophageal carcinoma received three-dimensional conformal radiotherapy or intensity modulated radiotherapy

    International Nuclear Information System (INIS)

    Wang Lan; Wang Jun; Han Chun; Zhang Jing; Li Xiaoning; Gao Chao

    2011-01-01

    Objective: To observe the acute side effects, local control rate and survival rate of concurrent chemoradiotherapy (CC) and radiotherapy alone (R) for patients with esophageal carcinoma. Methods: From June 2006 to February 2009, 209 patients with esophageal carcinoma were observed, 105 of them were treated with CC. Of all the patients, 117 received three-dimensional conformal radiotherapy, 92 received intensity modulated radiotherapy, the median prescription dose was 60 Gy. The regimen of LFP (5-FU, cisplatin and calcium folinate) was selected for this study, side effects, local control rate and survival rate were observed and subsets analysis were performed. Results: The overall follow-up rate was 99.0%,there were 99 and 44 patients whose follow-up time was more than 2 and 3 years, respectively;for the CC group, the data were 45 and 14, respectively; and for the R group, 54 and 30, respectively. The 1-, 2-, 3-year local control rates of CC group and R group were 88.1%, 69.2%, 66.2% and 81.0%, 64.0%, 54.9% (χ 2 =2.31, P=0.128), respectively. The 1-, 2-, 3-year overall survival rates of CC group and R group were 84.4%, 52.9%, 45.6% and 75.2%, 50.7%, 37.0%(χ 2 =1.57, P=0.210), respectively. Subset analysis indicated that for the patients of N 0 group and whose length of GTV >7 cm, the local control rate of CC was significantly higher than that of radiotherapy alone (χ 2 =5.11, 7.66; P=0.024, 0.006). For N 0 group, the survival rate of CC was higher than that of R alone. (χ 2 =5.07, P=0.024). The incidence of WBC, PLT and HGB reduction for the two groups were 81.9% and 49.0% (χ 2 =36.45, P=0.000), 14.3% and 1.9% (χ 2 =10.54, P=0.006), and 24.8% and 2.9% (χ 2 =22.95, P=0.000), respectively. The incidence of nausea, vomiting and constipation for the two groups were 63.8% and 7.7% (χ 2 =71.52, P=0.000), respectively. The incidence of ≥2 grade esophagitis of CC group and R group were 48.57% and 38.46% (χ 2 =2.17, P=0.141), respectively. The incidence of ≥2

  16. The Influence of Pressure Distribution on the Maximum Values of Stress in FEM Analysis of Plain Bearings

    Directory of Open Access Journals (Sweden)

    Vasile Cojocaru

    2016-12-01

    Full Text Available Several methods can be used in the FEM studies to apply the loads on a plain bearing. The paper presents a comparative analysis of maximum stress obtained for three loading scenarios: resultant force applied on the shaft – bearing assembly, variable pressure with sinusoidal distribution applied on the bearing surface, variable pressure with parabolic distribution applied on the bearing surface.

  17. Predictive Value of Urodynamics on Outcome After Midurethral Sling Surgery for Female Stress Urinary Incontinence EDITORIAL COMMENT

    NARCIS (Netherlands)

    Houwert, R. Marijn; Venema, Pieter L.; Aquarius, Annelies E.; Bruinse, Hein W.; Kil, Paul J. M.; Vervest, Harry A. M.

    2009-01-01

    Urodynamic investigation (UDI) is routinely performed before midurethral sling surgery (MUS) for female stress urinary incontinence to detect factors that may adversely affect the surgical outcome or confirm the diagnosis. A recent review, however, concluded that there was insufficient evidence to

  18. Growth and content of Spirulina platensis biomass chlorophyll cultivated at different values of light intensity and temperature using different nitrogen sources

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    Eliane Dalva Godoy Danesi

    2011-03-01

    Full Text Available The effects of light intensity and temperature in S. platensis cultivation with potassium nitrate or urea as nitrogen source were investigated, as well as the biomass chlorophyll contents of this cyanobacteria, through the Response Surface Methodology. Experiments were performed at temperatures from 25 to 34.5ºC and light intensities from 15 to 69 µmol photons m-2 s-1, in mineral medium. In cultivations with both sources of nitrogen, KNO3 and urea, statistic evaluation through multiple regression, no interactions of such independent variables were detected in the results of the dependent variables maximum cell concentration, chlorophyll biomass contents, cell and chlorophyll productivities, as well as in the nitrogen-cell conversion factor. In cultivation performed with both sources of nitrogen, it was possible to obtain satisfactory adjustments to relate the dependent variables to the independent variables. The best results were achieved at temperature of 30ºC, at light intensity of 60 µmol photons m-2s-1, for cell growth, with cell productivity of approximately 95 mg L-1 d-1 in cultivations with urea. For the chlorophyll biomass content, the most adequate light intensity was 24 µmol photons m-2 s-1.

  19. A pilot study on peritraumatic dissociation and coping styles as risk factors for posttraumatic stress, anxiety and depression in parents after their child's unexpected admission to a Pediatric Intensive Care Unit

    NARCIS (Netherlands)

    Bronner, Madelon B.; Kayser, Anne-Marie; Knoester, Hendrika; Bos, Albert P.; Last, Bob F.; Grootenhuis, Martha A.

    2009-01-01

    ABSTRACT: Aim: To study the prevalence of posttraumatic stress, anxiety and depression in parents three months after pediatric intensive care treatment of their child and examine if peritraumatic dissocation and coping styles are related to these mental health problems. METHODS: This is a

  20. Zoonotic and Non-Zoonotic Diseases in Relation to Human Personality and Societal Values: Support for the Parasite-Stress Model

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    Randy Thornhill

    2010-04-01

    Full Text Available The parasite-stress model of human sociality proposes that humans' ontogenetic experiences with infectious diseases as well as their evolutionary historical interactions with these diseases exert causal influences on human psychology and social behavior. This model has been supported by cross-national relationships between parasite prevalence and human personality traits, and between parasite prevalence and societal values. Importantly, the parasite-stress model emphasizes the causal role of non-zoonotic parasites (which have the capacity for human-to-human transmission, rather than zoonotic parasites (which do not, but previous studies failed to distinguish between these conceptually distinct categories. The present investigation directly tested the differential predictive effects of zoonotic and non-zoonotic (both human-specific and multihost parasite prevalence on personality traits and societal values. Supporting the parasite-stress model, cross-national differences in personality traits (unrestricted sexuality, extraversion, openness to experiences and in societal values (individualism, collectivism, gender equality, democratization are predicted specifically by non-zoonotic parasite prevalence.

  1. c-Fos expression in the supraoptic nucleus is the most intense during different durations of restraint water-immersion stress in the rat.

    Science.gov (United States)

    Zhang, Yu-Yu; Zhu, Wen-Xing; Cao, Guo-Hong; Cui, Xi-Yun; Ai, Hong-Bin

    2009-09-01

    Restraint water-immersion stress (RWIS) can induce anxiety, hypothermia, and severe vagally-mediated gastric dysfunction. The present work explored the effects of different durations of RWIS on neuronal activities of the forebrain by c-Fos expression in conscious rats exposed to RWIS for 0, 30, 60, 120, or 180 min. The peak of c-Fos induction was distinct for different forebrain regions. The most intense c-Fos induction was always observed in the supraoptic nucleus (SON), and then in the hypothalamic paraventricular nucleus (PVN), posterior cortical amygdaloid nucleus (PCoA), central amygdaloid nucleus (CeA), and medial prefrontal cortex (mPFC). Moreover, body temperature was reduced to the lowest degree after 60 min of RWIS, and the gastric lesions tended to gradually worsen with the prolonging of RWIS duration. These data strongly suggest that these nuclei participate in the organismal response to RWIS to different degrees, and may be involved in the hypothermia and gastric lesions induced by RWIS.

  2. The Effectiveness of Mindfulness-Based Stress Reduction on Perceived Pain Intensity and Quality of Life in Patients With Chronic Headache.

    Science.gov (United States)

    Bakhshani, Nour Mohammad; Amirani, Ahmadreza; Amirifard, Hamed; Shahrakipoor, Mahnaz

    2015-08-06

    The aim of this study was to determine the effectiveness of Mindfulness-Based Stress reduction (MBSR) on perceived pain intensity and quality of life in patients with chronic headache. Thus, forty patients based on the diagnosis of a neurologist and diagnostic criteria of the International Headache Society (IHS) for migraine and chronic tension-type headache were selected and randomly assigned to the intervention group and control group, respectively. The participants completed the Pain and quality of life (SF-36) questionnaire. The intervention group enrolled in an eight-week MBSR program that incorporated meditation and daily home practice, per week, session of 90-minutes. Results of covariance analysis with the elimination of the pre-test showed significantly improvement of pain and quality of life in the intervention group compared with the control group. The findings from this study revealed that MBSR can be used non-pharmacological intervention for improvement the quality of life and development of strategies to cope with pain in patients with chronic headache. And can be used in combination with other therapies such as pharmacotherapy.

  3. Resistive indices of cerebral arteries in very preterm infants : values throughout stay in the neonatal intensive care unit and impact of patent ductus arteriosus

    NARCIS (Netherlands)

    Ecury-Goossen, Ginette M; Raets, Marlou M A; Camfferman, Fleur A; Vos, Rik H J; van Rosmalen, Joost; Reiss, Irwin K M; Govaert, Paul; Dudink, Jeroen

    BACKGROUND: Little is known about cerebral artery resistive index values in infants born extremely preterm. OBJECTIVE: To report resistive index values in various cerebral arteries in a prospective cohort of preterm infants born at <29 weeks' gestation, and to compare resistive index in these

  4. Predictive value of age for coping: the role of self-efficacy, social support satisfaction and perceived stress.

    Science.gov (United States)

    Trouillet, Raphaël; Gana, Kamel; Lourel, Marcel; Fort, Isabelle

    2009-05-01

    The present study was prompted by the lack of agreement on how coping changes with age. We postulate that the effect of age on coping is mediated by coping resources, such as self-efficacy, perceived stress and social support satisfaction. The participants in the study were community dwelling and aged between 22 and 88 years old. Data were collected using the General Self Efficacy Scale, the Social Support Questionnaire, the Perceived Stress Scale, the Geriatric Depression Scale, the Social Readjustment Rating Scale (life-events) and the Way of Coping Checklist. We performed path analyses for two competitive structural models: M1 (age does not directly affect coping processes) and M2 (age directly affects coping processes). Our results supported a modified version of M2. Age was not found to predict either of two coping strategies: problem-focused coping is predicted by self-efficacy and social support satisfaction; emotion-focused coping is predicted by social support satisfaction and perceived stress. Changes in coping over the lifespan reflect the effectiveness with which a person's adaptive processes deal with age-associated changes in self-referred beliefs and environment perception.

  5. The Clinical Value of Non-Coplanar Photon Beams in Biologically Optimized Intensity Modulated Dose Delivery on Deep-Seated Tumours

    International Nuclear Information System (INIS)

    Ferreira, Brigida C.; Svensson, Roger; Loef, Johan; Brahme, Anders

    2003-01-01

    The aim of the present study is to compare the merits of different radiobiologically optimized treatment techniques using few-field planar and non-coplanar dose delivery on an advanced cancer of the cervix, with rectum and bladder as principal organs at risk. Classically, the rational for using non-coplanar beams is to minimize the overlap of beam entrance and exit regions and to find new beam directions avoiding organs at risk, in order to reduce damage to sensitive normal tissues. Two four-beam configurations have been extensively studied. The first consists of three evenly spaced coplanar beams and a fourth non-coplanar beam. A second tetrahedral-like configuration, with two symmetric non-coplanar beams at the same gantry angle and two coplanar beams, with optimized beam directions, was also tested. The present study shows that when radiobiologically optimized intensity modulated beams are applied to such a geometry, only a marginal increase in the treatment outcome can be achieved by non-coplanar beams compared to the optimal coplanar treatment. The main reason for this result is that the high dose in the beam-overlap regions is already optimally reduced by biologically optimized intensity modulation in the plane. The large number of degrees of freedom already incorporated in the treatment by the use of intensity modulation and radiobiological optimization, leads to the saturation of the benefit acquired by a further increase in the degrees of freedom with non-coplanar beams. In conclusion, the use coplanar of radiobiologically optimized intensity modulation simplifies the dose delivery, reducing the need for non-coplanar beam portals

  6. The effects of aerobic exercise training at two different intensities in obesity and type 2 diabetes: implications for oxidative stress, low-grade inflammation and nitric oxide production.

    Science.gov (United States)

    Krause, Mauricio; Rodrigues-Krause, Josianne; O'Hagan, Ciara; Medlow, Paul; Davison, Gareth; Susta, Davide; Boreham, Colin; Newsholme, Philip; O'Donnell, Mark; Murphy, Colin; De Vito, Giuseppe

    2014-02-01

    To investigate the effect of 16 weeks of aerobic training performed at two different intensities on nitric oxide (tNOx) availability and iNOS/nNOS expression, oxidative stress (OS) and inflammation in obese humans with or without type 2 diabetes mellitus (T2DM). Twenty-five sedentary, obese (BMI > 30 kg/m2) males (52.8 ± 7.2 years); 12 controls versus 13 T2DM were randomly allocated to four groups that exercised for 30 min, three times per week either at low (Fat-Max; 30-40% VO(2max)) or moderate (T(vent); 55-65 % VO(2max)) intensity. Before and after training, blood and muscle samples (v. lateralis) were collected. Baseline erythrocyte glutathione was lower (21.8 ± 2.8 vs. 32.7 ± 4.4 nmol/ml) and plasma protein oxidative damage and IL-6 were higher in T2DM (141.7 ± 52.1 vs. 75.5 ± 41.6 nmol/ml). Plasma catalase increased in T2DM after T(vent) training (from 0.98 ± 0.22 to 1.96 ± 0.3 nmol/min/ml). T2DM groups demonstrated evidence of oxidative damage in response to training (elevated protein carbonyls). Baseline serum tNOx were higher in controls than T2DM (18.68 ± 2.78 vs. 12.34 ± 3.56 μmol/l). Training at T(vent) increased muscle nNOS and tNOx in the control group only. Pre-training muscle nNOS was higher in controls than in T2DMs, while the opposite was found for iNOS. No differences were found after training for plasma inflammatory markers. Exercise training did not change body composition or aerobic fitness, but improved OS markers, especially when performed at T(vent). Non-diabetics responded to T(vent) training by increasing muscle nNOS expression and tNOx levels in skeletal muscle while these parameters did not change in T2DM, perhaps due to higher insulin resistance (unchanged after intervention).

  7. Threshold values characterizing iodine-induced SCC of zircaloys

    International Nuclear Information System (INIS)

    Une, K.

    1984-01-01

    Threshold values of stress, stress intensity factor, strain, strain rate and iodine concentration for SCC of unirradiated and irradiated Zircaloys are reviewed. The ratio of σsub(th)/σsub(y) adequately represents the effects of cold work and irradiation damage on the SCC susceptibility, where threshold stress σsub(th) is defined as the minimum stress to cause SCC to failure after -6 and 10 -3 min -1 . A comparison of SCC data between constant strain rate and constant stress tests is presented in order to examine the validity of a cumulative-damage concept under SCC conditions. (author)

  8. Characterization of Residual Stress Effects on Fatigue Crack Growth of a Friction Stir Welded Aluminum Alloy

    Science.gov (United States)

    Newman, John A.; Smith, Stephen W.; Seshadri, Banavara R.; James, Mark A.; Brazill, Richard L.; Schultz, Robert W.; Donald, J. Keith; Blair, Amy

    2015-01-01

    An on-line compliance-based method to account for residual stress effects in stress-intensity factor and fatigue crack growth property determinations has been evaluated. Residual stress intensity factor results determined from specimens containing friction stir weld induced residual stresses are presented, and the on-line method results were found to be in excellent agreement with residual stress-intensity factor data obtained using the cut compliance method. Variable stress-intensity factor tests were designed to demonstrate that a simple superposition model, summing the applied stress-intensity factor with the residual stress-intensity factor, can be used to determine the total crack-tip stress-intensity factor. Finite element, VCCT (virtual crack closure technique), and J-integral analysis methods have been used to characterize weld-induced residual stress using thermal expansion/contraction in the form of an equivalent delta T (change in local temperature during welding) to simulate the welding process. This equivalent delta T was established and applied to analyze different specimen configurations to predict residual stress distributions and associated residual stress-intensity factor values. The predictions were found to agree well with experimental results obtained using the crack- and cut-compliance methods.

  9. Clinical value of the major types of reactions of the body’s stress-regulating systems in ischemic stroke

    Directory of Open Access Journals (Sweden)

    Aleksandr Mikhailovich Dolgov

    2013-01-01

    Full Text Available The time course of changes in the parameters reflecting the status of different components of the body’s regulatory systems was studied in 125patients with hemispheric ischemic stroke via comprehensive evaluation of the hypothalamo-pituitary axes and some endocrine glands. There were three types of reactions of the body’s stress-regulating systems: 1 normergic; 2 hyperergic; 3 disergic, which characterized adaptive and disadaptive reactions in stroke. The changes in the nitroxydergic mechanisms of vascular tone regulation, which constrain the possible involvement of the vascular wall endothelium in the body’s adaptive reactions, progress as the condition becomes severe.

  10. The Value of Screening Parents for Their Risk of Developing Psychological Symptoms After PICU: A Feasibility Study Evaluating a Pediatric Intensive Care Follow-Up Clinic.

    Science.gov (United States)

    Samuel, Victoria M; Colville, Gillian A; Goodwin, Sarah; Ryninks, Kirsty; Dean, Suzanne

    2015-11-01

    This study aimed to assess whether prospectively screening parents for psychological vulnerability would enable beneficial targeting of a subsequent follow-up clinic. Parents of children consecutively admitted to a PICU were assessed for risk of developing posttraumatic stress disorder at discharge using the Posttraumatic Adjustment Scale. High-risk parents were then randomized to the intervention (follow-up clinic, 2 mo after discharge) or control condition. All parents completed Impact of Event Scale-Revised and Hospital Anxiety and Depression Scale at 6 months. Of the 209 parents of 145 children recruited to the study, 78 (37%) were identified, on the basis of their Posttraumatic Adjustment Scale score at baseline, as being at risk of developing posttraumatic stress disorder, and randomized to the control or intervention condition. Follow-up data were provided by 157 of 209 parents (75%). Logistic regression analyses controlling for parent gender and child length of stay showed that high-risk control parents (n = 32) were significantly more likely to score above the clinical cutoff for all three psychological outcomes than parents deemed low risk at baseline (n = 89) (posttraumatic stress: odds ratio = 3.39; 95% CI, 1.28-8.92; p = 0.014; anxiety: odds ratio = 6.34; 95% CI, 2.55-15.76; p parents attended the follow-up clinic appointment they were offered. At follow-up, there were no statistically significant differences between the intervention and control groups, but there were small effect sizes in favor of the intervention for anxiety scores (Cohen d = 0.209) and depression scores (Cohen d = 0.254) CONCLUSIONS:: Screening parents for psychological vulnerability using measures such as the Posttraumatic Adjustment Scale may enable more efficient targeting of support. However, further research is needed on how best to provide effective follow-up intervention for families.

  11. Clinical value of periventricular low-intensity areas detected by fluid attenuated inversion recovery (FLAIR). Relationships between perinatal vital parameter and neonatal MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kadowaki, Sachiko; Iwata, Osuke; Tamura, Masanori [Nagano Children' s Hospital, Toyoshina (Japan)] (and others)

    2002-01-01

    A follow-up study was performed to assess the correlation among the incidence of periventricular low intensities (PVLI) on MRI (magnetic resonance imaging) FLAIR (fluid attenuated inversion recovery) imaging, clinical evidence of perinatal insults that may cause white matter damage, and the outcome of the infants. We evaluated periventricular white matter lesions of 329 neonates whose MRI were obtained before two months corrected age. The detective rate of periventricular abnormalities on FLAIR imaging was significantly higher than that of T1-T2 weighted imaging. The most typical lesion detected on FLAIR imaging was periventricular low intensities (PVLI), frequently observed in the neonates with a history of preterm labour, very low birth weight, birth asphyxia and severe respiratory failure. Although we could not characterize the risk factors of PVLI, the incidence of PVLI had a strong correlation with the scores of motor and developmental tests at 12 and 36-months corrected age. In conclusion, FLAIR imaging, detecting the border zone damage of white matter, would be a strong tool to pick out neonates at high risk of neurological disturbances from those without clinical evidence of neurological insults in the neonatal period. (author)

  12. The economic value of remote sensing of earth resources from space: An ERTS overview and the value of continuity of service. Volume 3: Intensive use of living resources: Agriculture. Part 1: Overview

    Science.gov (United States)

    Kornhauser, A. L.; Wilson, L. B.

    1974-01-01

    Potential economic benefits obtainable from a state-of-the-art ERS system in the resource area of intensive use of living resources, agriculture, are studied. A spectrum of equal capability (cost saving), increased capability, and new capability benefits are quantified. These benefits are estimated via ECON developed models of the agricultural marketplace and include benefits of improved production and distribution of agricultural crops. It is shown that increased capability benefits and new capability benefits result from a reduction of losses due to disease and insect infestation given ERS's capability to distinguish crop vigor and from the improvement in world trade negotiations given ERS's worldwide surveying capability.

  13. The value and throughput of rest Thallium-201/stress Technetium -99m sestamibi dual-isotope myocardial SPECT.

    Science.gov (United States)

    Okudan, Berna; Smitherman, Thomas C

    2004-06-01

    Myocardial perfusion scintigraphy is an established method in cardiology for the diagnosis and evaluation of coronary artery disease (CAD). Thallium-201 and Tc-99m sestamibi myocardial perfusion imaging has been widely accepted as non-invasive diagnostic procedure for detection of CAD, risk stratification and myocardial viability assessment. But, standard Tl-201 redistribution and same day or 2-day rest/stress Tc-99m sestamibi protocols are time-consuming. Hence, the dual isotope rest thallium-201/stress technetium-99m sestamibi gated single-photon emission tomography protocol has gained increasing popularity for these applications. Combining the use of thallium-201 with technetium-99m agents permits optimal image resolution and simultaneous assessment of viability. Dual-isotope imaging may be separate or simultaneous acquisition set-up. The more rapid completion of these studies is appreciated as an advantage by patients, technologists, interpreting and referring physicians, nurses and hospital management. Simultaneous imaging has the potential advantages of precise pixel registration and artifacts, if present, are identical in both thallium and sestamibi, and require only one set of imaging. Also, there are some disadvantages of spillover of activity from the Tc-99m to the Tl-201 window. Fortunately, despite this problem it can be overcome. Separate acquisition dual isotope also has some disadvantages. Difference in defect resolution in attenuation and scatter between T-201 and Tc-99m sestamibi potentially results in interpretation problems. But, studies about cost-effectiveness of dual isotope imaging showed that some selective elimination of the rest studies may decrease the cost of the nuclear procedures and should be considered in the current care health system.

  14. Errors and limits in the determination of plasma electron density by measuring the absolute values of the emitted continuum radiation intensity

    International Nuclear Information System (INIS)

    Bilbao, L.; Bruzzone, H.; Grondona, D.

    1994-01-01

    The reliable determination of a plasma electron structure requires a good knowledge of the errors affecting the employed technique. A technique based on the measurements of the absolute light intensity emitted by travelling plasma structures in plasma focus devices has been used, but it can be easily modified to other geometries and even to stationary plasma structures with time-varying plasma densities. The purpose of this work is to discuss in some detail the errors and limits of this technique. Three separate errors are shown: the minimum size of the density structure that can be resolved, an overall error in the measurements themselves, and an uncertainty in the shape of the density profile. (author)

  15. The economic value of remote sensing of earth resources from space: An ERTS overview and the value of continuity of service. Volume 3: Intensive use of living resources, agriculture. Part 2: Distribution effects

    Science.gov (United States)

    Bradford, D. F.; Kelejian, H. H.

    1974-01-01

    The results of an investigation of the value of improving information for forecasting future crop harvests are described. A theoretical model is developed to calculate the value of increased speed of availablitiy of that information. The analysis of U.S. domestic wheat consumption was implemented. New estimates of a demand function for wheat and of a cost of storage function were involved, along with a Monte Carlo simulation for the wheat spot and future markets and a model of market determinations of wheat inventories. Results are shown to depend critically on the accuracy of current and proposed measurement techniques.

  16. Measurements of emission rates of hydrocarbons from sunflower as a function of temperature, light intensity and stress (ozone levels); Bestimmung von Emissionsraten pflanzlicher Kohlenwasserstoffe bei Sonnenblumen in Abhaengigkeit von Temperatur, Lichtintensitaet und Stress, insbesondere von der Belastung mit Ozon

    Energy Technology Data Exchange (ETDEWEB)

    Schuh, G.; Wildt, J.; Kley, D.

    1996-08-01

    The emission rates of isoprene, mono- and sesquiterpenes from sunflower (Helianthus annuus L. cv. giganteus) were determined in an environmental chamber, a continuously stirred tank reactor. {alpha}-pinene, {beta}-caryophyllene and two oxygenated compounds were emitted. The emission rates of all terpenes increased exponentially with temperature. Substance specific differences of the rate of increase of the emission rates were observed. For all substances the dependence of their emission rates on temperature increased with increasing light intensity. Increasing lightflux resulted in an increase of the emission rates for all substances. The raise of emission rates with lightflux was dependent on temperature and increased with increasing temperature. During periods without plant stress the emission rates exhibited a good correlation with the rate of transpiration as well as with the rate of net photosynthesis. Sunflowers emitted higher amounts of terpenes when they were stressed by mechanical, wounding and ozone treatment as well as nutrient- or water deficiency. The emission rates increased by a factor of 5-300. Exposure with ozone had an effect on hydrocarbon emission rates with a delay-time. 3-4 h after exposure with 25-120 ppb ozone the emission rates increased by factor of 5-100. This increase was only observed on the first day of exposure. Nutrient deficiency resulted in an increase of emission rates by a factor of 10-300. In situations of mechanical, wounding and ozone stress, substance specific changes in the emission spectrum were observed. A model was developed to explain the observed phenomena. The main pathway of ozone loss in the chamber is caused by the uptake through the stomata of the plants. However, up to 50% of the ozone loss must be explained by other processes indirectly caused by the plants. (orig./MG) [Deutsch] In Laborversuchen wurden Emissionsraten biogener Kohlenwasserstoffe von Sonnenblumen gemessen. Die groessten Emissionsraten wiesen die

  17. Effect of pH Value on the Electrochemical and Stress Corrosion Cracking Behavior of X70 Pipeline Steel in the Dilute Bicarbonate Solutions

    Science.gov (United States)

    Cui, Z. Y.; Liu, Z. Y.; Wang, L. W.; Ma, H. C.; Du, C. W.; Li, X. G.; Wang, X.

    2015-11-01

    In this work, effects of pH value on the electrochemical and stress corrosion cracking (SCC) behavior of X70 pipeline steel in the dilute bicarbonate solutions were investigated using electrochemical measurements, slow strain rate tensile tests and surface analysis techniques. Decrease of the solution pH from 6.8 to 6.0 promotes the anodic dissolution and cathodic reduction simultaneously. Further decrease of the pH value mainly accelerates the cathodic reduction of X70 pipeline steel. As a result, when the solution pH decreases form 6.8 to 5.5, SCC susceptibility decreases because of the enhancement of the anodic dissolution. When the solution pH decreases from 5.5 to 4.0, SCC susceptibility increases gradually because of the acceleration of cathodic reactions.

  18. Methods for determining thermal stresses values. Some examples relating to nuclear reactors; Methodes de determination des contraintes thermiques. Quelques exemples d'application aux reacteurs

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, J; Gautier, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Peres, A [Israel Institute of Technology, Dept. of Nuclear Science Technion (Israel)

    1958-07-01

    As modern techniques develop more elaborate machines, and make their way towards higher and higher temperatures and pressures, the thermal stresses become a matter of major importance in the design of mechanical structures. In the first part of this paper, the authors examine the problem from a theoretical standpoint, and try to evaluate the aptitude and limitation of mathematical techniques to attain the quantitative values of thermal stresses. This paper deals mainly with the experimental methods to measure thermal stresses. The authors show some examples relating to nuclear reactors. (author)Fren. [French] Au fur et a mesure que la technique moderne developpe des machines plus poussees et s'oriente vers des temperatures et des pressions toujours plus elevees, les contraintes thermiques deviennent un facteur d'importance capitale dans le calcul des structures mecaniques. Les auteurs examinent d'abord l'aspect theorique du probleme, ainsi que l'aptitude et les limites du calcul pour exprimer quantitativement la valeur des contraintes thermiques. Les auteurs exposent principalement, ensuite, les methodes experimentales qui permettent de mesurer ces contraintes, et illustrent cet expose de quelques exemples relatifs aux installations nucleaires. (auteur)

  19. Value of conventional, and diffusion- and perfusion weighted MRI in the management of patients with unclear cerebral pathology, admitted to the intensive care unit

    International Nuclear Information System (INIS)

    Sundgren, P.C.; Reinstrup, P.; Romner, B.; Holtaas, S.; Maly, P.

    2002-01-01

    The aim of our retrospective study was to determine the extent to which diffusion- and perfusion- weighted MRI combined with conventional MRI could be helpful in the evaluation of intensive care unit (ICU) patients who have unknown or unclear cerebral pathology underlying a serious clinical condition. Twenty-one ICU patients with disparity between the findings on brain CT scan and their clinical status were studied. All patients underwent conventional MR and diffusion-weighted imaging and 14 also had MR perfusion studies. Abnormalities were present on diffusion-weighted imaging of 17 of the 21 patients and on perfusion-weighted studies of 7 of 14 patients. The MRI results changed the preliminary/working diagnosis in six patients. In eight other patients, MRI revealed additional pathology that had not been suspected clinically, and/or characterized more closely findings that had already been detected by CT or suspected clinically. MRI showed abnormalities in four of the five patients who had normal CT. MRI findings suggested a negative clinical outcome in all nine patients who subsequently died. MRI findings also suggested positive long-term outcome in five of nine patients who improved significantly as based on Glasgow and extended Glasgow outcome scales. In the three unconscious patients who had normal diffusion- and perfusion-weighted imaging the clinical outcome was good. This study suggests that MRI in seriously ill ICU patients with unclear cerebral pathology can provide information that changes, characterizes, or supports diagnoses and/or prognoses and therefore facilitates further management. (orig.)

  20. The value of Doppler LiDAR systems to monitor turbulence intensity during storm events in order to enhance aviation safety in Iceland

    Science.gov (United States)

    Yang, Shu; Nína Petersen, Guðrún; Finger, David C.

    2017-04-01

    Turbulence and wind shear are a major natural hazards for aviation safety in Iceland. The temporal and spatial scale of atmospheric turbulence is very dynamic, requiring an adequate method to detect and monitor turbulence with high resolution. The Doppler Light Detection and Ranging (LiDAR) system can provide continuous information about the wind field using the Doppler effect form emitted light signals. In this study, we use a Leosphere Windcube 200s LiDAR systems stationed near Reykjavik city Airport and at Keflavik International Airport, Iceland, to evaluate turbulence intensity by estimating eddy dissipation rate (EDR). For this purpose, we retrieved radial wind velocity observations from Velocity Azimuth Display (VAD) scans (360°scans at 15° and 75° elevation angle) to compute EDR. The method was used to monitor and characterize storm events in fall 2016 and the following winter. The preliminary result reveal that the LiDAR observations can detect and quantify atmospheric turbulence with high spatial and temporal resolution. This finding is an important step towards enhanced aviation safety in subpolar climate characterized by sever wind turbulence.

  1. The optimal exercise intensity for the unbiased comparison of thermoregulatory responses between groups unmatched for body size during uncompensable heat stress.

    Science.gov (United States)

    Ravanelli, Nicholas; Cramer, Matthew; Imbeault, Pascal; Jay, Ollie

    2017-03-01

    We sought to identify the appropriate exercise intensity for unbiased comparisons of changes in rectal temperature (ΔT re ) and local sweat rates (LSR) between groups unmatched for body size during uncompensable heat stress. Sixteen males vastly different in body morphology were separated into two equal groups [small (SM): 65.8 ± 6.2 kg, 1.8 ± 0.1 m 2 ; large (LG): 100.0 ± 13.1 kg, 2.3 ± 0.1 m 2 ], but matched for sudomotor thermosensitivity (SM: 1.3 ± 0.6; LG: 1.1 ± 0.4 mg·cm -2 ·min -1 ·°C -1 ). The maximum potential for evaporation (E max ) for each participant was assessed using an incremental humidity protocol. On separate occasions, participants then completed 60 min of cycling in a 35°C and 70% RH environment at (1) 50% of VO 2max , (2) a heat production (H prod ) of 520 W, (3) H prod relative to mass (6 W·kg -1 ), and (4) H prod relative to mass above E max (3 W·kg -1 >E max ). E max was similar between LG (347 ± 39 W, 154 ± 15 W·m -2 ) and SM (313 ± 63 W, 176 ± 34 W·m -2 , P  >   0.12). ΔT re was greater in SM compared to LG at 520 W (SM: 1.5 ± 0.5; LG 0.8 ± 0.3°C, P  E max (SM: 1.4 ± 0.5; LG 1.3 ± 0.4°C, P  =   0.99). LSR was similar between LG and SM irrespective of condition, suggesting maximum LSR was attained (SM: 1.10 ± 0.23; LG: 1.07 ± 0.35 mg·cm -2 ·min -1 , P  =   0.50). In conclusion, systematic differences in ΔT re and LSR between groups unmatched for body size during uncompensable heat stress can be avoided by a fixed H prod in W·kg -1 or W·kg -1 >E max . © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  2. Bleeding and pneumonia in intensive care patients given ranitidine and sucralfate for prevention of stress ulcer: meta-analysis of randomised controlled trials

    Science.gov (United States)

    Messori, A; Trippoli, S; Vaiani, M; Gorini, M; Corrado, A

    2000-01-01

    Objectives To determine the effectiveness of ranitidine and sucralfate in the prevention of stress ulcer in critical patients and to assess if these treatments affect the risk of nosocomial pneumonia. Design Published studies retrieved through Medline and other databases. Five meta-analyses evaluated effectiveness in terms of bleeding rates (A: ranitidine v placebo; B: sucralfate v placebo) and infectious complications in terms of incidence of nosocomial pneumonia (C: ranitidine v placebo; D: sucralfate v placebo; E: ranitidine v sucralfate). Trial quality was determined with an empirical ad hoc procedure. Main outcome measures Rates of clinically important gastrointestinal bleeding and nosocomial pneumonia (compared between the two study arms and expressed with odds ratios specific for individual studies and meta-analytic summary odds ratios). Results Meta-analysis A (five studies) comprised 398 patients; meta-analysis C (three studies) comprised 311 patients; meta-analysis D (two studies) comprised 226 patients: and meta-analysis E (eight studies) comprised 1825 patients. Meta-analysis B was not carried out as the literature search selected only one clinical trial. In meta-analysis A ranitidine was found to have the same effectiveness as placebo (odds ratio of bleeding 0.72, 95% confidence interval 0.30 to 1.70, P=0.46). In placebo controlled studies (meta-analyses C and D) ranitidine and sucralfate had no influence on the incidence of nosocomial pneumonia. In comparison with sucralfate, ranitidine significantly increased the incidence of nosocomial pneumonia (meta-analysis E: 1.35, 1.07 to 1.70, P=0.012). The mean quality score in the four analyses (on a 0 to 10 scale) ranged from 5.6 in meta-analysis E to 6.6 in meta-analysis A. Conclusions Ranitidine is ineffective in the prevention of gastrointestinal bleeding in patients in intensive care and might increase the risk of pneumonia. Studies on sucralfate do not provide conclusive results. These findings are

  3. Prognostic value of high-dose dobutamine stress magnetic resonance imaging in 1,493 consecutive patients: assessment of myocardial wall motion and perfusion.

    Science.gov (United States)

    Korosoglou, Grigorios; Elhmidi, Yacine; Steen, Henning; Schellberg, Dieter; Riedle, Nina; Ahrens, Johannes; Lehrke, Stephanie; Merten, Constanze; Lossnitzer, Dirk; Radeleff, Jannis; Zugck, Christian; Giannitsis, Evangelos; Katus, Hugo A

    2010-10-05

    This study sought to determine the prognostic value of wall motion and perfusion assessment during high-dose dobutamine stress (DS) cardiac magnetic resonance imaging (MRI) in a large patient cohort. DS-MRI offers the possibility to integrate myocardial perfusion and wall motion analysis in a single examination for the detection of coronary artery disease (CAD). A total of 1,493 consecutive patients with suspected or known CAD underwent DS-MRI, using a standard protocol in a 1.5-T magnetic resonance scanner. Wall motion and perfusion were assessed at baseline and during stress, and outcome data including cardiac death, nonfatal myocardial infarction ("hard events"), and "late" revascularization performed >90 days after the MR scans were collected during a 2 ± 1 year follow-up period. Fifty-three hard events, including 14 cardiac deaths and 39 nonfatal infarctions, occurred during the follow-up period, whereas 85 patients underwent "late" revascularization. Using multivariable regression analysis, an abnormal result for wall motion or perfusion during stress yielded the strongest independent prognostic value for both hard events and late revascularization, clearly surpassing that of clinical and baseline magnetic resonance parameters (for wall motion: adjusted hazard ratio [HR] of 5.9 [95% confidence interval (CI): 2.5 to 13.6] for hard events and of 3.1 [95% CI: 1.7 to 5.6] for late revascularization, and for perfusion: adjusted HR of 5.4 [95% CI: 2.3 to 12.9] for hard events and of 6.2 [95% CI: 3.3 to 11.3] for late revascularization, p < 0.001 for all). DS-MRI can accurately identify patients who are at increased risk for cardiac death and myocardial infarction, separating them from those with normal findings, who have very low risk for future cardiac events. (Prognostic Value of High Dose Dobutamine Stress Magnetic Resonance Imaging; NCT00837005). Copyright © 2010 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  4. The influence of value of intensity of constant electric field on structure, thermal physic and conductivity nanocomposites epoxy resin-oxide metal

    International Nuclear Information System (INIS)

    Vilensky, V.O.; Demchenko, V.I.

    2009-01-01

    Influence of constant electric field on structure, specific thermal capacity, thermomechanical properties and electrical conduction nanocomposites on a basis epoxy resin and fillers Fe 2 O 3 , Al 2 O 3 is investigated. The received results show, that application of constant electric field gives the chance to influence level of perfection of crystal structure filler (Fe 2 O 3 ) in structure to a composite, thus the size of crystals decreases from 18.0 nm (for initial samples of composites) to 7.7 nm (for the composites generated under the influence of CEF). Nanocomposites generated in CEF characterization the higher values of a electrical conduction

  5. The prognostic value of 99MTc-MIBI stress-rest myocardial perfusion imaging in patients suspected with coronary artery disease

    International Nuclear Information System (INIS)

    Wu Zhifang; Li Sijin; Liu Jianzhong; Zhang Wanchun

    2004-01-01

    Objective: To evaluate the prognostic value of 99mTc-MIBI stress-rest myocardial perfusion imaging (MPI) for patients suspected with coronary artery disease (CAD). Methods: 206 consecutive patients suspected with CAD (165 males, 41 females; age range 16-90 years, mean age 55.94±12.46 years) underwent 99mTc-MIBI stress-rest myocardial perfusion imaging (two days protocol), 57 pts with hypertension, 68 pts with hyperlipemia, 39 pts with diabetes and 62 pts with the family history of CAD. According to the imaging results, the 206 patients were divided into 3 groups. G1, normal, 135 pts; G2, reversible defects, 20 pts; G3, fixed defects, 51 pts. The mean time of follow-up was 33.25±14.95 (1-56) months. Results: The rate of cardiac events (CE) occurrence of the three groups was 1.5% (2/135), 65% ( 13/20) and 7.8% (4/51) respectively and there was significant difference between them. Kaplan-Meier survival curves analyzing the no-CE rates in the three groups, ischemic patients demonstrated a more significantly lower than normal and infarction ones in the no-CE rates(Log-rank statistic, chi-square 124.89, P <0.0001). The better predictor of future cardiac events is the reversible defect. Over all, 23.9% of the patients with abnormal stress MPI occurred cardiac events, but only 7.5% of the patients with abnormal rest ones did(chi-square 5.80, P =0.016). The prognoses of patients with normal stress MPI result were better than those with normal rest ones (1.5% versus 9.7%, chi-square 8.94, P =0.0028). Compared with rest MPI, the stress one is a better predictable method to analyze the patient' s condition and evaluate the prognosis. Conclusions: 99mTc-MIBI stress-rest myocardial perfusion imaging is a better Methods to evaluate the prognosis of patients suspected with CAD, and the rate of CE occurrence was 65% in reversible defects patients in this study. (authors)

  6. Academic Expectations as Sources of Stress in Asian Students

    Science.gov (United States)

    Tan, Joyce Beiyu; Yates, Shirley

    2011-01-01

    Education is highly valued in Confucian Heritage Culture (CHC) countries such as China, Taiwan, Singapore, Hong Kong, Japan and Korea but the expectations of parents, teachers and students themselves to excel academically can also be a source of intense stress for many students. The "Academic Expectations Stress Inventory" (AESI),…

  7. Bell's palsy: what is the prognostic value of measurements of signal intensity increases with contrast enhancement on MRI?

    Energy Technology Data Exchange (ETDEWEB)

    Kress, B.P.J.; Efinger, K.; Solbach, T.; Gottschalk, A.; Baehren, W. [Department of Radiology, Armed Forces Hospital, Deutsche Bundeswehr, Ulm (Germany); Griesbeck, F.; Kornhuber, A.W. [Department of Neurology/Psychiatry, Armed Forces Hospital, Deutsche Bundeswehr, Ulm (Germany)

    2002-05-01

    Our objective was to assess the prognostic value of measurements of the degree of contrast enhancement of the intratemporal segments of the facial nerve. We prospectively obtained MRI, slice thickness <1 mm of 20 patients with a facial palsy on the first day of inpatient treatment, and measured contrast enhancement of the nerve. The data were compared with compound muscle action potential (CMAP) measurements and the clinical course. Analysis of the initial enabled differentiation of three patients whose palsy was to show no improvement from 17 whose palsy was to resolve as expected. No patient with a poor outcome showed lesser increase in signal in the internal auditory canal, pars tympanica and pars mastoidea than patients who fully recovered. In no patient who had been diagnosed on the basis of the initial MRI as having a ''normal'' palsy was the amplitude of the (CMAP) reduced to less than 20% that of the normal side. Measurement of contrast enhancement was thus shown to be a prognostic indicator and may provide a basis for a differential treatment of facial palsy. (orig.)

  8. The contribution of total and free iodothyronines to welfare maintenance and management stress coping in Ruminants and Equines: Physiological ranges and reference values.

    Science.gov (United States)

    Ferlazzo, Adriana; Cravana, Cristina; Fazio, Esterina; Medica, Pietro

    2018-06-01

    In order to acquire a pattern of thyroid involvement in welfare maintenance in Ruminants and Equines, this review summarizes data concerning the reference values of total and free iodothyronines and their modifications in physiological conditions and in different management conditions (pregnancy, lactation, weaning, growth, isolation, restraint, shearing, confinement and transportation). Thyroidal and extrathyroidal tissues efficiently respond to management practices, giving a differentiated contribution to circulating iodothyronine changes. The hormonal response could be mainly attributed to the intracellular deiodination of T 4 to T 3. Triiodothyronine (T 3 ) and free iodothyronines (fT 3 and fT 4 ) result more responsive to management stress, showing different pattern with species and to various conditions, as to environmental conditions in which activities are performed. Intrinsic seasonal changes of iodothyronines and a significant pregnancy effect for T 3 were recorded in mares. Higher, although not significant, T 3 and T 4 concentrations in barren than pregnant mares were observed in donkeys. A positive significant correlation between T 3 and T 4 was described only in pregnant donkeys. Moreover, a significant effect of season on T 3 and fT 3 changes was observed both in pregnant and barren donkeys. A significant lactating effect compared with nonlactating stage for T 3 and T 4 was recorded in mares. In growing foals, body weight (BW) and age were positively correlated with T 3 and negatively correlated with T 4 , fT 4 and fT 3 . Weaning effects were shown for T 3 and fT 4 concentrations, indicating that weaning represents a severe stress and the presence of conspecific does not reduce psychological stress in this phase. Lambs showed significant decreased T 3 and elevated T 4 concentrations two weeks after weaning, with higher concentrations in both males and females compared to 24 h. Significant positive correlations were observed between BW and T 4 , fT 3

  9. Associations between sedation, delirium and post-traumatic stress disorder and their impact on quality of life and memories following discharge from an intensive care unit.

    Science.gov (United States)

    Svenningsen, Helle

    2013-04-01

    In the intensive care units (ICUs) sedation strategies have changed in the past decade towards less sedation and daily wake-up calls. Recent studies indicate that no sedation (after intubation) is most beneficial for patients. A smaller number of these patients have been assessed for post-trau