Toxic plasma concentration of ropivacaine after a paravertebral block in a patient suffering from severe hypoalbuminemia.

Science.gov (United States)

Calenda, Emile; Baste, Jean Marc; Hajjej, Ridha; Danielou, Eric; Peillon, Christophe

2014-03-01

A case of systemic ropivacaine toxicity from a continuous thoracic paravertebral block in an adult patient who received a lobectomy is presented. The catheter was placed by the surgeon. Eleven hours after the start of the infusion, the patient experienced an arrhythmia leading to death. The total venous plasma concentration of ropivacaine was high (3.2 μg/mL). Furthermore, the patient had severe hypoalbuminemia (albumin 24 g/L), which resulted in the increase of the unbound ropivacaine plasma concentration that was responsible for the toxic side effects. Copyright © 2014 Elsevier Inc. All rights reserved.

Continuous paravertebral infusion of ropivacaine with or without fentanyl for pain relief in unilateral multiple fractured ribs

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Medha Mohta

2013-01-01

Full Text Available Background: Continuous thoracic paravertebral block (TPVB provides effective analgesia for unilateral multiple fractured ribs (MFR. However, prolonged infusion of local anaesthetic (LA in high doses can predispose to risk of LA toxicity, which may be reduced by using safer drugs or drug combinations. This study was conducted to assess efficacy and safety of paravertebral infusion of ropivacaine and adrenaline with or without fentanyl to provide analgesia to patients with unilateral MFR. Methods: Thirty adults, having ≥3 unilateral MFR, with no significant trauma outside chest wall, were studied. All received bolus of 0.5% ropivacaine 0.3 ml/kg through paravertebral catheter, followed by either 0.1-0.2 ml/kg/hr infusion of ropivacaine 0.375% with adrenaline 5 μg/ml in group RA or ropivacaine 0.2% with adrenaline 5 μg/ml and fentanyl 2 μg/ml in group RAF. Rescue analgesia was provided by IV morphine. Results: Statistical analysis was performed using unpaired Student t-test, Chi-square test and repeated measures ANOVA. After TPVB, VAS scores, respiratory rate and PEFR improved in both groups with no significant inter-group differences. Duration of ropivacaine infusion, morphine requirements, length of ICU and hospital stay, incidence of pulmonary complications and opioid-related side-effects were similar in both groups. Ropivacaine requirement was higher in group RA than group RAF. No patient showed signs of LA toxicity. Conclusion: Continuous paravertebral infusion of ropivacaine 0.375% with adrenaline 5 μg/ml at 0.1-0.2 ml/kg/hr provided effective and safe analgesia to patients with unilateral MFR. Addition of fentanyl 2 μg/ml allowed reduction of ropivacaine concentration to 0.2% without decreasing efficacy or increasing opioid-related side-effects.

Ultrasound-guided paravertebral block for pyloromyotomy in 3 neonates with congenital hypertrophic pyloric stenosis

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Javier Mata-Gómez

2015-08-01

Full Text Available BACKGROUND AND OBJECTIVES: Hypertrophic pyloric stenosis is a relatively common affection of gastrointestinal tract in childhood that results in symptoms, such as projectile vomiting and metabolic disorders that imply a high risk of aspiration during anesthetic induction. In this way, the carrying out of a technique with general anesthesia and intravenous rapid sequence induction, preoxygenation and cricoid pressure are recommended. After the correction of systemic metabolic alkalosis and pH normalization, cerebrospinal fluid can keep a state of metabolic alkalosis. This circumstance, in addition to the residual effect of neuromuscular blocking agents, inhalant anesthetics and opioids could increase the risk of postoperative apnea after a general anesthesia.CASE REPORT: We present the successful management in 3 neonates in those a pyloromyotomy was carried out because they had presented congenital hypertrophic pyloric stenosis. This procedure was done under general anesthesia with orotracheal intubation and rapid sequence induction. Then, ultrasound-guided paravertebral block was performed as analgesic method without the need for administrating opioids within intraoperative period and keeping an appropriate analgesic level.CONCLUSIONS: Local anesthesia has demonstrated to be safe and effective in pediatric practice. We consider the ultrasound-guided paravertebral block with one dose as a possible alternative for other local techniques described, avoiding the use of opioids and neuromuscular blocking agents during general anesthesia, and reducing the risk of central apnea within postoperative period.

Ultrasound-Assisted Thoracic Paravertebral Block Reduces Intraoperative Opioid Requirement and Improves Analgesia after Breast Cancer Surgery: A Randomized, Controlled, Single-Center Trial.

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Lijian Pei

Full Text Available The contribution of ultrasound-assisted thoracic paravertebral block to postoperative analgesia remains unclear. We compared the effect of a combination of ultrasound assisted-thoracic paravertebral block and propofol general anesthesia with opioid and sevoflurane general anesthesia on volatile anesthetic, propofol and opioid consumption, and postoperative pain in patients having breast cancer surgery.Patients undergoing breast cancer surgery were randomly assigned to ultrasound-assisted paravertebral block with propofol general anesthesia (PPA group, n = 121 or fentanyl with sevoflurane general anesthesia (GA group, n = 126. Volatile anesthetic, propofol and opioid consumption, and postoperative pain intensity were compared between the groups using noninferiority and superiority tests.Patients in the PPA group required less sevoflurane than those in the GA group (median [interquartile range] of 0 [0, 0] vs. 0.4 [0.3, 0.6] minimum alveolar concentration [MAC]-hours, less intraoperative fentanyl requirements (100 [50, 100] vs. 250 [200, 300]μg,, less intense postoperative pain (median visual analog scale score 2 [1, 3.5] vs. 3 [2, 4.5], but more propofol (median 529 [424, 672] vs. 100 [100, 130] mg. Noninferiority was detected for all four outcomes; one-tailed superiority tests for each outcome were highly significant at P<0.001 in the expected directions.The combination of propofol anesthesia with ultrasound-assisted paravertebral block reduces intraoperative volatile anesthetic and opioid requirements, and results in less post operative pain in patients undergoing breast cancer surgery.ClinicalTrial.gov NCT00418457.

Continuous bilateral thoracic paravertebral blockade for analgesia after cardiac surgery: a randomised, controlled trial.

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Lockwood, Geoff G; Cabreros, Leilani; Banach, Dorota; Punjabi, Prakash P

2017-10-01

Continuous bilateral thoracic paravertebral blockade has been used for analgesia after cardiac surgery, but its efficacy has never been formally tested. Fifty adult patients were enrolled in a double-blind, randomised, controlled study of continuous bilateral thoracic paravertebral infusion of 0.5% lidocaine (1 mg.kg -1 .hr -1 ) for analgesia after coronary surgery. Control patients received a subcutaneous infusion of lidocaine at the same rate through catheters inserted at the same locations as the study group. The primary outcome was morphine consumption at 48 hours using patient-controlled analgesia (PCA). Secondary outcomes included pain, respiratory function, nausea and vomiting. Serum lidocaine concentrations were measured on the first two post-operative days. There was no difference in morphine consumption or in any other outcome measure between the groups. Serum lidocaine concentrations increased during the study, with a maximum of 5.9 mg.l -1 . There were no adverse events as a consequence of the study. Bilateral paravertebral infusion of lidocaine confers no advantage over systemic lidocaine infusion after cardiac surgery. ISRCTN13424423 ( https://www.isrctn.com ).

Preoperative paravertebral blocks for the management of acute pain following mastectomy: a cost-effectiveness analysis.

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Offodile, Anaeze C; Sheckter, Clifford C; Tucker, Austin; Watzker, Anna; Ottino, Kevin; Zammert, Martin; Padula, William V

2017-10-01

Preoperative paravertebral blocks (PPVBs) are routinely used for treating post-mastectomy pain, yet uncertainties remain about the cost-effectiveness of this modality. We aim to evaluate the cost-effectiveness of PPVBs at common willingness-to-pay (WTP) thresholds. A decision analytic model compared two strategies: general anesthesia (GA) alone versus GA with multilevel PPVB. For the GA plus PPVB limb, patients were subjected to successful block placement versus varying severity of complications based on literature-derived probabilities. The need for rescue pain medication was the terminal node for all postoperative scenarios. Patient-reported pain scores sourced from published meta-analyses measured treatment effectiveness. Costing was derived from wholesale acquisition costs, the Medicare fee schedule, and publicly available hospital charge masters. Charges were converted to costs and adjusted for 2016 US dollars. A commercial payer perspective was adopted. Incremental cost-effectiveness ratios (ICERs) were evaluated against WTP thresholds of $500 and $50,000 for postoperative pain control. The ICER for preoperative paravertebral blocks was $154.49 per point reduction in pain score. 15% variation in inpatient costs resulted in ICER values ranging from $124.40-$180.66 per pain point score reduction. Altering the probability of block success by 5% generated ICER values of $144.71-$163.81 per pain score reduction. Probabilistic sensitivity analysis yielded cost-effective trials 69.43% of the time at $500 WTP thresholds. Over a broad range of probabilities, PPVB in mastectomy reduces postoperative pain at an acceptable incremental cost compared to GA. Commercial payers should be persuaded to reimburse this technique based on convincing evidence of cost-effectiveness.

In-plane ultrasound-guided thoracic paravertebral block: a preliminary report of 36 cases with radiologic confirmation of catheter position.

NARCIS (Netherlands)

Renes, S.H.; Bruhn, J.; Gielen, M.J.M.; Scheffer, G.J.; Geffen, G.J. van

2010-01-01

BACKGROUND AND OBJECTIVES: Thoracic paravertebral block (TPVB) can be used for unilateral surgical procedures. Modifications of the classic approach have been proposed to minimize the risk of pleural puncture. In this study, we evaluated the feasibility and success rate of a transverse in-plane

Effect of adding magnesium sulphate to bupivacaine on the clinical profile of ultrasound-guided thoracic paravertebral block in patients undergoing modified radical mastectomy

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Mohamed Elsayed Hassan

2015-01-01

Conclusion: Adding magnesium sulphate to bupivacaine in ultrasound-guided paravertebral block resulted in more efficient analgesia and opioid-sparing in female patients undergoing modified radical mastectomy.

A comparative randomized study of paravertebral block versus wound infiltration of bupivacaine in modified radical mastectomy

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Parul Bansal

2012-01-01

Full Text Available Background: Paravertebral block (PVB has the potential to offer long-lasting pain relief because it can uniquely eliminate cortical responses to thoracic dermatomal stimulation. Benefits include a reduction in postoperative nausea and vomiting (PONV, prolonged postoperative pain relief, and potential for ambulatory discharge. Aims: To compare PVB with local infiltration for postoperative analgesia following modified radical mastectomy (MRM. Methods: Forty patients undergoing MRM with axillary dissection were randomly allocated into two groups. Following induction of general anesthesia in group P, a catheter was inserted in the paravertebral space and 0.3 ml/kg of 0.25 % of bupivacaine was administered followed by continuous infusion, while in group L, the surgical incision was infiltrated with 0.3 ml/kg of 0.25 % bupivacaine. Statistical Analysis: The statistical tests were applied as unpaired student ′t′ test/nonparametric test Wilcoxon Mann Whitney test for comparing different parameters such as VAS score and consumption of drugs. The categorical variables such as nausea and vomiting scores, sedation score, and patient satisfaction score were computed by Chi square test/Fisher exact test. Results: VAS score was significantly lower in group P than in group L throughout the postoperative period. The mean alertness score (i.e., less sedation was higher in group P in the postoperative period than group L. The incidence of PONV was less in PVB group. Conclusion: PVB at the end of the surgery results in better postoperative analgesia, lesser incidence of PONV, and better alertness score.

Effects of thoracic paravertebral block with bupivacaine versus combined thoracic epidural block with bupivacaine and morphine on pain and pulmonary function after cholecystectomy

DEFF Research Database (Denmark)

Bigler, D; Dirkes, W; Hansen, R

1989-01-01

Twenty patients undergoing elective cholecystectomy via a subcostal incision were randomized in a double-blind study to either thoracic paravertebral blockade with bupivacaine 0.5% (15 ml followed by 5 ml/h) or thoracic epidural blockade with bupivacaine 7 ml 0.5% + morphine 2 mg followed by 5 ml...... by forced vital capacity, forced expiratory volume and peak expiratory flow rate decreased about 50% postoperatively in both groups. In conclusion, the continuous paravertebral bupivacaine infusion used here was insufficient as the only analgesic after cholecystectomy. In contrast, epidural blockade...... with combined bupivacaine and low dose morphine produced total pain relief in six of ten patients....

The application of paravertebral block in high-risk patient with cardiorespiratory, liver and kidney problems: a case report

OpenAIRE

ŽUPČIĆ, MIROSLAV; GRAF ŽUPČIĆ, SANDRA; BRUNDULA, ANA; ZRINJŠČAK, IVA KOREČIĆ; PERŠEC, JASMINKA; HUSEDŽINOVIĆ1, INO

2015-01-01

Background and Purpose: We present a case report of a patient of the American Society of Anesthesiologists’ (ASA) IV scheduled for a modified radical mastectomy (MRM) due to malignant disease. The patient was a high risk patient for general anesthesia and we opted for the application of unilateral paravertebral block on several levels. Case report. A 86-year-old female was scheduled for a surgery due to recurrent malignant process on her right breast. She was an ASA IV patie...

Analgesic Choice in Management of Rib Fractures: Paravertebral Block or Epidural Analgesia?

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Malekpour, Mahdi; Hashmi, Ammar; Dove, James; Torres, Denise; Wild, Jeffrey

2017-06-01

Rib fractures are commonly encountered in the setting of trauma. The aim of this study was to assess the association between the clinical outcome of rib fracture and epidural analgesia (EA) versus paravertebral block (PVB) using the National Trauma Data Bank (NTDB). Using the 2011 and 2012 versions of the NTDB, we retrieved completed records for all patients above 18 years of age who were admitted with rib fractures. Primary outcome was in-hospital mortality. Secondary outcomes were length of stay (LOS), intensive care unit (ICU) admission, ICU LOS, mechanical ventilation, duration of mechanical ventilation, development of pneumonia, and development of any other complication. Clinical outcomes were first compared between propensity score-matched EA and PVB patients. Then, EA and PVB patients were combined into the procedure group and the outcomes were compared with propensity score-matched patients that received neither intervention (no-procedure group). A total of 194,766 patients were included in the study with 1073 patients having EA, 1110 patients having PVB, and 192,583 patients having neither procedure. After propensity score matching, comparison of primary and secondary outcomes between EA and PVB patients showed no difference. Comparison of propensity score-matched procedure and no-procedure patients showed prolonged LOS and more frequent ICU admissions in patients receiving a procedure (both P rib fractures. There was an association between use of a block and improved outcome, but this could be explained by selection of healthier patients to receive a block. Prospective study of this association is recommended.

The evaluation of efficacy and safety of paravertebral block for perioperative analgesia in patients undergoing laparoscopic cholecystectomy

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Anil Agarwal

2012-01-01

Full Text Available Background: Paravertebral block is a popular regional anesthetic technique used for perioperative analgesia in multiple surgical procedures. There are very few randomized trials of its use in laparoscopic cholecystectomy in medical literature. This study was aimed at assessing its efficacy and opioid-sparing potential in this surgery. Methods: Fifty patients were included in this prospective randomized study and allocated to two groups: Group A (25 patients receiving general anesthesia alone and Group B (25 patients receiving nerve-stimulator-guided bilateral thoracic Paravertebral Block (PVB at T6 level with 0.3 ml/kg of 0.25% bupivacaine prior to induction of general anesthesia. Intraoperative analgesia was supplemented with fentanyl (0.5 μg/kg based on hemodynamic and clinical parameters. Postoperatively, patients in both the groups received Patient-Controlled Analgesia (PCA morphine for the first 24 hours. The efficacy of PVB was assessed by comparing intraoperative fentanyl requirements, postoperative VAS scores at rest, and on coughing and PCA morphine consumption between the two groups. Results: Intraoperative supplemental fentanyl was significantly less in Group B compared to Group A (17.6 μg and 38.6 μg, respectively, P =0.001. PCA morphine requirement was significantly low in the PVB group at 2, 6, 12, and 24 hours postoperatively compared to that in Group A (4.4 mg vs 6.9 mg, 7.6 mg vs 14.2 mg, 11.6 mg vs 20.0 mg, 16.8 mg vs 27.2 mg, respectively; P <0.0001 at all intervals. Conclusion: Pre-induction PVB resulted in improved analgesia for 24 hours following laparoscopic cholecystectomy in this study, along with a significant reduction in perioperative opioid consumption and opioid-related side effects.

Thoracic paravertebral block versus intravenous patient-controlled analgesia for pain treatment in patients with multiple rib fractures.

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Yeying, Ge; Liyong, Yuan; Yuebo, Chen; Yu, Zhang; Guangao, Ye; Weihu, Ma; Liujun, Zhao

2017-12-01

Objectives To assess the effect of thoracic paravertebral block (PVB) on pain management and preservation of pulmonary function compared with intravenous, patient-controlled analgesia (IVPCA) in patients with multiple rib fractures (MRFs). Methods Ninety patients with unilateral MRFs were included in this prospective study and randomly assigned to the TPVB or IVPCA group. The visual analogue scale (VAS) pain score, blood gas analysis, and bedside spirometry were measured and recorded at different time points after analgesia. Results TPVB and IVPCA provided good pain relief. VAS scores were significantly lower in the TPVB group than in the IVPCA group at rest and during coughing ( P pain relief and preservation of pulmonary function in patients with MRFs.

Pharmacokinetics of Lidocaine Hydrochloride Administered with or without Adrenaline for the Paravertebral Brachial Plexus Block in Dogs.

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Choquette, Amélie; Troncy, Eric; Guillot, Martin; Varin, France; Del Castillo, Jérôme R E

2017-01-01

Adrenaline is known to prolong the duration of local anesthesia but its effects on the pharmacokinetic processes of local anesthetic drugs are not fully understood. Our objective was to develop a compartmental model for quantification of adrenaline's impact on the pharmacokinetics of perineurally-injected lidocaine in the dog. Dogs were subjected to paravertebral brachial plexus block using lidocaine alone or adrenalinated lidocaine. Data was collected through a prospective, randomised, blinded crossover protocol performed over three periods. Blood samples were collected during 180 minutes following block execution. Compartmental pharmacokinetic models were developed and their goodness-of-fit were compared. The lowering effects of adrenaline on the absorption of lidocaine were statistically determined with one-sided tests. A one-compartment disposition model with two successive zero-order absorption processes best fitted our experimental data. Adrenaline decreased the peak plasma lidocaine concentration by approximately 60% (P Adrenaline decreased the absorption rate of lidocaine and prolonged the duration of its absorption.

Analgesic efficacy of ultrasound-guided paravertebral block versus serratus plane block for modified radical mastectomy: A randomised, controlled trial

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Kapil Gupta

2017-01-01

Full Text Available Background and Aims: Modified radical mastectomy (MRM may be associated with severe post-operative pain, leading to chronic pain syndrome. We compared the post-operative analgesic profile of two ultrasound-guided nerve blocks: Paravertebral block (PVB and serratus plane block (SPB. Methods: This double-blind, randomised study was conducted on fifty adult females, scheduled for MRM with axillary dissection. After inducing general anaesthesia with intravenous midazolam 1 mg, fentanyl 1.5 mcg/kg, propofol 1–2 mg/kg and vecuronium 0.1 mg/kg, patients were administered either ultrasound-guided thoracic PVB at T4 (n = 25 or SPB at 5th rib (n = 25 with 20 ml of 0.5% bupivacaine, both as a single level injection. Time to first rescue analgesia and morphine consumption in 4, 6, 24, 48 and 72 h by PCA pump, visual analogue scale score and any adverse effects were recorded. Quantitative variables were compared using the unpaired t-test or the Mann–Whitney U test between the two groups. Qualitative variables were compared using the Chi-square test or Fisher's exact test. Results: The duration of analgesia (mean ± Standard deviation [SD] was significantly longer in the PVB group compared to SPB group (346 ± 57 min vs. 245.6 ± 58 min, P< 0.001. The post-operative 24 h morphine consumption (mean ± SD was significantly higher in the SPB group (9.7 ± 2.1 mg compared to PVB group (6.5 ± 1.5 mg (P < 0.001. Conclusion: Ultrasound-guided SPB is an alternative analgesic technique to thoracic PVB for MRM although PVB provides a longer duration of analgesia.

Comparison of caudal ropivacaine-morphine and paravertebral catheter for major upper abdominal surgery in infants.

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Sato, Makoto; Iida, Takafumi; Kikuchi, Chika; Sasakawa, Tomoki; Kunisawa, Takayuki

2017-05-01

The caudal epidural block is one of the most commonly used regional anesthetic techniques in children. Administration of morphine via caudal injection enables analgesia, even for upper abdominal surgery. The thoracic paravertebral block has also been successfully used to treat perioperative pain during upper abdominal procedures in pediatric patients. In the current study, we compared the two regional techniques for upper abdominal surgery in infants to determine whether one of them was preferable to the other. Consecutive patients under 12 months of age who underwent upper abdominal surgery were retrospectively divided according to the chosen postoperative analgesia: Group C, caudal ropivacaine-morphine; Group P, paravertebral catheter. We analyzed the following outcomes: requirement for additional analgesics, pain scores, need for mechanical ventilation and oxygen dosage, postoperative blood pressure and heart rate, time to pass first stool, time until first full meal, and complications. Twenty-one consecutive patients were included: 10 in Group C and 11 in Group P. Median age at surgery was 80 (47.5-270.0) and 84.5 (34.3-287.5) days, respectively. No difference was found between the two groups in requirement for additional analgesics at 24 h after surgery (median 1 in Group C vs 1 in Group P, P = 0.288, 95% CI: -2 to 1). BOPS pain scores were only lower in Group P when compared to Group C at 24 h after surgery (median 1 vs 2, P = 0.041, 95% CI: -2 to 0). None of the patients had perioperative complications. In this small series, there was no significant difference between caudal ropivacaine-morphine and paravertebral catheter for postoperative care in infants undergoing upper abdominal surgery. Further prospective studies are needed to compare the efficacy and incidence of complications of caudal block and paravertebral catheter for postoperative analgesia. © 2017 John Wiley & Sons Ltd.

Effects of electric paravertebral muscle relaxation processes in the athletes heart

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D. V. Syshko

2013-02-01

Full Text Available Influence of paravertebrals miorelaxation on electric processes in a heart at sportsmen is studied. Paravertebrals miorelaxation was the complex of exercises in a water environment directed on the decline of tone of paravertebral muscles. Before and after it was used of paravertebrals miorelaxation registered the indexes of electrocardiography at the sportsmen engaged in the Greek-Roman fight (n=22 by football (n=24 and heavy athletics (n=25. It is got, that at the sportsmen of engaged in the Greek -Roman fight after paravertebrals miorelaxation QRS and QT were it was increased, and R-R and PQ went down. At the sportsmen of engaged in heavy athletics HR and PQ went down after paravertebrals miorelaxation, R-R, QRS and QT were it was increased. At the sportsmen of getting busy by football the PQ interval shortened, and QRS and QT has multiplied. Findings testify to the presence of different mechanisms of adaptation of the conducting system of heart in the conditions of influencing of paravertebrals miorelaxation. These distinctions are fated by two basic factors: by the functional being of the cardio-vessels system on the whole and functional being of sine knot and conducting system of heart in particular.

Paravertebral block catheter breakage by electrocautery during thoracic surgery.

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Saeki, Noboru; Sugimoto, Yuki; Mori, Yoko; Kato, Takahiro; Miyoshi, Hirotsugu; Nakamura, Ryuji; Koga, Tomomichi

2017-06-01

Advantages of thoracic paravertebral analgesia (TPA) include placement of the catheter closer to the surgical field; however, the catheter can become damaged during the operation. We experienced a case of intraoperative TPA catheter breakage that prompted us to perform an experiment to investigate possible causes. A 50-year-old male underwent a thoracoscopic lower lobectomy under general anesthesia with TPA via an intercostal approach. Following surgery, it was discovered that the catheter had become occluded, as well as cut and fused, so we reopened the incision and removed the residual catheter. From that experience, we performed an experiment to examine electrocautery-induced damage in normal (Portex™, Smith's Medical), radiopaque (Perifix SoftTip™, BBraun), and reinforced (Perifix FX™, BBraun) epidural catheters (n = 8 each). Chicken meat was penetrated by each catheter and then cut by electrocautery. In the normal group, breakage occurred in 8 and occlusion in 6 of the catheters, and in the radiopaque group breakage occurred in 8 and occlusion in 7. In contrast, breakage occurred in only 3 and occlusion in none in the reinforced group, with the 5 without breakage remaining connected only by the spring coil. Furthermore, in 7 of the reinforced catheters, electric arc-induced thermal damage was observed at the tip of the catheter. A TPA catheter for thoracic surgery should be inserted via the median approach, or it should be inserted after surgery to avoid catheter damage during surgery.

Disorders of paravertebral lumbar muscles: from pathology to cross-sectional imaging

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Bierry, Guillaume; Kremer, Stephane; Abu Eid, Maher; Bogorin, Adriana; Dietemann, Jean-Louis [University Hospital, Hautepierre Hospital, Department of Radiology 2, Strasbourg (France); Kellner, Frauke [Inselspital Bern, Department of Radiology, Berne (Switzerland)

2008-11-15

Paravertebral lumbar muscles are important for spine stabilization and mobility. They may be abnormal in several disorders that may be associated with pain or functional impairment. Special attention should be paid to the paravertebral muscles during imaging, so that a possible muscular disease is not overlooked, especially in patients with low back pain. This article reviews such imaging abnormalities. (orig.)

Disorders of paravertebral lumbar muscles: from pathology to cross-sectional imaging

International Nuclear Information System (INIS)

Bierry, Guillaume; Kremer, Stephane; Abu Eid, Maher; Bogorin, Adriana; Dietemann, Jean-Louis; Kellner, Frauke

2008-01-01

Paravertebral lumbar muscles are important for spine stabilization and mobility. They may be abnormal in several disorders that may be associated with pain or functional impairment. Special attention should be paid to the paravertebral muscles during imaging, so that a possible muscular disease is not overlooked, especially in patients with low back pain. This article reviews such imaging abnormalities. (orig.)

CT-Guided Biopsy in Suspected Spondylodiscitis--The Association of Paravertebral Inflammation with Microbial Pathogen Detection.

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Daniel Spira

Full Text Available To search for imaging characteristics distinguishing patients with successful from those with futile microbiological pathogen detection by CT-guided biopsy in suspected spondylodiscitis.34 consecutive patients with suspected spondylodiscitis underwent CT-guided biopsy for pathogen detection. MR-images were assessed for inflammatory infiltration of disks, adjacent vertebrae, epidural and paravertebral space. CT-images were reviewed for arrosion of adjacent end plates and reduced disk height. Biopsy samples were sent for microbiological examination in 34/34 patients, and for additional histological analysis in 28/34 patients.Paravertebral infiltration was present in all 10/10 patients with positive microbiology and occurred in only 12/24 patients with negative microbiology, resulting in a sensitivity of 100% and a specificity of 50% for pathogen detection. Despite its limited sensitivities, epidural infiltration and paravertebral abscesses showed considerably higher specificities of 83.3% and 90.9%, respectively. Paravertebral infiltration was more extensive in patients with positive as compared to negative microbiology (p = 0.002. Even though sensitivities for pathogen detection were also high in case of vertebral and disk infiltration, or end plate arrosion, specificities remained below 10%.Inflammatory infiltration of the paravertebral space indicated successful pathogen detection by CT-guided biopsy. Specificity was increased by the additional occurrence of epidural infiltration or paravertebral abscesses.

Paravertebral Burkitt's Lymphoma in a Child: An Unusual Presentation

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C. Hoyoux

2012-01-01

Full Text Available Paravertebral malignant tumors constitute 4.8% of cancer cases in pediatric oncology and are mostly composed of neuroblastoma (46.4% and soft tissue sarcomas (35.7%. We describe the case of a Caucasian 6-year-old boy who was admitted for middle back pain radiated to limbs and progressively increasing weakness of the legs, suggesting a spinal cord disease. The exploration revealed two paravertebral masses extending through the neural foraminae into the epidural space. The association with elevated serum neuron specific enolase suggested at first the diagnosis of neuroblastoma, but the pathological examination revealed a Burkitt's lymphoma. This is a rare location of sporadic Burkitt's lymphoma with neurologic syndrome as first symptoms.

Treatment with hydroxyurea in thalassemia intermedia with paravertebral pseudotumors of extramedullary hematopoiesis.

Science.gov (United States)

Cario, H; Wegener, M; Debatin, K-M; Kohne, E

2002-08-01

Excessive ineffective erythropoiesis in thalassemia intermedia may cause paravertebral pseudotumors of extramedullary hematopoiesis. Due to the proximity to the spinal canal, these paravertebral masses carry the risk of severe neurological damage. Treatment strategies include hypertransfusion, radiotherapy, and laminectomy. Hydroxyurea, stimulating fetal hemoglobin synthesis, may represent an alternative therapeutic approach. We report on a 26-year-old patient suffering from thalassemia intermedia with progressive anemia symptoms and presenting multiple intrathoracic paravertebral pseudotumors of extramedullary hematopoiesis. Hypertransfusion therapy and splenectomy were followed by regular transfusion (baseline hemoglobin 10 g/dl) and chelation with desferrioxamine. With this treatment, clinical symptoms disappeared, paravertebral hematopoietic masses did not progress, but severe hemosiderosis developed within a few years. Hydroxyurea therapy was initiated to increase the efficacy of erythropoiesis, thereby reducing the required transfusion volume but suppressing concomitantly further expansion of extramedullary hematopoiesis, and finally leading to a reduction of transfusional iron load. Treatment was started with 4 mg/kg per day and stepwise increased to 12.5 mg/kg per day. The fetal hemoglobin concentration increased from 4.5 to 5.5 g/dl after 1 year and to 9.9 g/dl after 2 years of treatment. The yearly transfusion volume was halved during the 1st year of treatment. At present, after 26 months of treatment, the patient has been transfusion-independent for 10 months. Serum ferritin levels decreased from 2844 to 1335 ng/ml. Size and shape of paravertebral hematopoietic pseudotumors remained stable. No side effects of hydroxyurea have been observed. In thalassemia intermedia patients with extramedullary hematopoiesis, hydroxyurea may lead to independence from regular transfusion therapy without further expansion of ectopic hematopoietic tissue.

Ultrasound-guided approach to the paravertebral space for catheter insertion in infants and children.

Science.gov (United States)

Boretsky, Karen; Visoiu, Mihaela; Bigeleisen, Paul

2013-12-01

Paravertebral perineural blocks are used to prevent pain in the thoracoabdominal dermatomes. Traditionally, a landmark-based technique is used in children, while ultrasound-guided (UG) techniques are being employed in adult patients. To describe an UG technique for placement of thoracic paravertebral nerve block (TPVNB) catheters in pediatric patients. Retrospective chart review of a series of 22 pediatric patients' ages 6 months to 17 years with weights from 6.25 kg to 135 kg using a transverse in-plane technique. Catheters were placed both bilateral and unilateral for a variety of thoracic and abdominal procedures. A linear ultrasound transducer was used in all cases with frequency of oscillation and transducer length chosen based on individual patient characteristics of age, weight, and BMI. The median pain scores at 12, 24, 36, and 48 h were 1.2 (interquartile range, 4.5), 0.84 (interquartile range 3.0), 1.6 (interquartile range 2.9), and 0.83 (interquartile range 1.74), respectively. The median dose of opioid expressed as morphine equivalents consumed during the first 24 h after surgery was 0.14 mg·kg(-1) (interquartile range, 0.78 mg·kg(-1) ) and from 24 to 48 h the median dose was 0.11 mg·kg(-1) (interquartile range 0.44 mg·kg(-1) ). No complications were noted, and catheters were left an average of 3 days with a range of 1-5 days with good pain relief. This technical description demonstrates the feasibility of placing PVNB catheters using a transverse in-line ultrasound-guided technique in a wide range of pediatric patients. © 2013 John Wiley & Sons Ltd.

1.5 T augmented reality navigated interventional MRI: paravertebral sympathetic plexus injections.

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Marker, David R; U Thainual, Paweena; Ungi, Tamas; Flammang, Aaron J; Fichtinger, Gabor; Iordachita, Iulian I; Carrino, John A; Fritz, Jan

2017-01-01

The high contrast resolution and absent ionizing radiation of interventional magnetic resonance imaging (MRI) can be advantageous for paravertebral sympathetic nerve plexus injections. We assessed the feasibility and technical performance of MRI-guided paravertebral sympathetic injections utilizing augmented reality navigation and 1.5 T MRI scanner. A total of 23 bilateral injections of the thoracic (8/23, 35%), lumbar (8/23, 35%), and hypogastric (7/23, 30%) paravertebral sympathetic plexus were prospectively planned in twelve human cadavers using a 1.5 Tesla (T) MRI scanner and augmented reality navigation system. MRI-conditional needles were used. Gadolinium-DTPA-enhanced saline was injected. Outcome variables included the number of control magnetic resonance images, target error of the needle tip, punctures of critical nontarget structures, distribution of the injected fluid, and procedure length. Augmented-reality navigated MRI guidance at 1.5 T provided detailed anatomical visualization for successful targeting of the paravertebral space, needle placement, and perineural paravertebral injections in 46 of 46 targets (100%). A mean of 2 images (range, 1-5 images) were required to control needle placement. Changes of the needle trajectory occurred in 9 of 46 targets (20%) and changes of needle advancement occurred in 6 of 46 targets (13%), which were statistically not related to spinal regions (P = 0.728 and P = 0.86, respectively) and cadaver sizes (P = 0.893 and P = 0.859, respectively). The mean error of the needle tip was 3.9±1.7 mm. There were no punctures of critical nontarget structures. The mean procedure length was 33±12 min. 1.5 T augmented reality-navigated interventional MRI can provide accurate imaging guidance for perineural injections of the thoracic, lumbar, and hypogastric sympathetic plexus.

Effects of Thoracic Paravertebral Block on Postoperative Analgesia and Serum Level of Tumor Marker in Lung Cancer Patients Undergoing Video-assisted Thoracoscopic Surgery

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Jiheng CHEN

2015-02-01

Full Text Available Background and objective Perioperative management of pain associated with the prognosis of cancer patients. Optimization of perio-perative analgesia method, then reduce perioperative stress response, reduce opioiddosage, to reduce or even avoid systemic adverse reactions and elevated levels of tumor markers. Serum levels of tumor markers in patients with lung cancer are closely related to tumor growth. Clinical research reports on regional anesthesia effect on tumor markers for lung cancer are still very little in domesticliterature. The aim of this study is to evaluate the effects of thoracic paraverte-bral block on postoperative analgesia and serum level of tumor marker in lung cancer patients undergoing video-assisted thoracoscopic surgery. Methods Lung cancer patients undergoing video-assisted thoracoscopic surgery were randomly divided into 2 groups (n=20 in each group. The patients in group G were given only general anesthesia. The thoracic paravertebral blockade (PVB was performed before general anesthesia in patients of group GP. The effect of PVB was judged by testing area of block. Patient controlled intravenous analgesia (PCIA pump started before the end of surgery in 2 groups. Visual analogue scale (VAS score was recorded after extubation 2 h (T1, 24 h (T2 and 48 h (T3 after surgery and the times of PCIA and the volume of analgesic drugs used were recorded during 48 h after surgery. The serum levels of carcino-embryonic antigen (CEA, carbohydrate antigen 199 (CA199, carbohydrate antigen 125 (CA125, neuron-specific enolase (NSE, cytokeratin 19 fragment (CYFRA21-1 and squamous cell carcinoma (SCC in 40 lung cancer cases undergoing video-assisted thoracoscopic lobectomy were measured before operation and 24 h after operation. Results Forty American Society of Anesthesiologists (ASA physical status I or II patients, aged 20 yr-70 yr, body mass index (BMI 18 kg/m2-25 kg/m2, scheduled for elective video-assisted thoraeoscopic lobectomy

Paravertebral Abscess Caused by Bukholderia Pseudomallei in

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S Ahmad

2009-05-01

Full Text Available A 53-year-old Malay man was admitted with intestinal obstruction, fever and lower limb weakness. Initial clinical impression was myelitis causing paralytic ilues and paraperesis. Blood culture showed Burkholderia pseudomallei infection and subsequent MRI showed paravertebral abscess. This case highlights a rare manifestation of melioidosis involving the spine and difficulties in establishing the diagnosis.

Thoracic Paravertebral Mass as an Infrequent Manifestation of IgG4-Related Disease

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Melissa Matzumura Kuan

2017-01-01

Full Text Available Case. A 50-year-old African American male presented with abdominal pain and significant weight loss. On physical examination, he had parotid and submandibular gland enlargement associated with right eye proptosis. Computed tomography showed a thoracic paravertebral soft tissue mass, enlarged lymph nodes, and ascending aortic aneurysm. Laboratory results were remarkable for elevated total IgG and IgG4 subclass. The submandibular gland pathology revealed chronic sclerosing sialadenitis, with a large subset of inflammatory cells positively staining for IgG4. The histology of the paravertebral mass demonstrated fibrosclerosis with increased lymphocytic infiltrate, associated with increased IgG4 plasma cells. He was diagnosed with immunoglobulin G4-related disease (IgG4-RD. Steroid therapy initially yielded improvement; however, after steroids were stopped, there was disease recurrence. Prednisone was restarted, and the plan was to start him on rituximab. Interestingly, the patient’s brother also had IgG4-RD. Conclusion. IgG4-RD can present as a paravertebral mass which is usually responsive to steroids; however, recurrent and resistant disease can be seen for which steroid-sparing agents such as rituximab should be considered. In addition, to the best of our knowledge, this is the first reported case of IgG4-RD in two family members presenting as a paravertebral mass, highlighting an exciting area for more research in the future.

[Sclerosing epithelioid fibrosarcoma of the paravertebral column. Case report and literature review].

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Puerta Roldán, Patricia; Rodríguez Rodríguez, Rodrigo; Bagué Rossell, Silvia; de Juan Delago, Manel; Molet Teixidó, Joan

2013-01-01

Sclerosing epithelioid fibrosarcoma (SEF) is a rare variant of low-grade fibrosarcoma, with specific histological and immunohistochemical features and a poor prognosis. We report a case of SEF of the paravertebral column in a 49-year old male who presented a paraspinal mass with extension into the L4-L5 neural foramen and invasion of the L5 nerve root. Histology of the tumourectomy specimen and its immunohistochemical study led to the diagnosis of SEF. This case was particularly unusual due to its paravertebral column location and, despite its low grade, illustrates the malignant potential of SEF. Copyright © 2012 Sociedad Española de Neurocirugía. Published by Elsevier España. All rights reserved.

Brucellaspondylodiscitis and Paravertebral Abscess with Negative Serology: A Case Report

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Farazi A.A.

2012-04-01

Full Text Available Background and Objectives: Brucellosis is a common zoonosis which still remains as a major health problem in certain parts of the world. Osteoarticular involvement is the most frequent complication of brucellosis, in which the diagnosis of brucellarspondylodiscitis is often difficult, since the clinical presentation may be obscured by many other conditions.Case Report: We report an uncommon case of spondylodiscitis with paravertebral abscess. The diagnosis was established by using magnetic resonance imaging that was also confirmed by positive culture. This report describes a case of a 42-year-old woman. Serodiagnosis for brucella carried out at the onset of symptoms 4 months and 1.5 months before admission were negative. When the patient was admitted to our hospital, laboratory tests showed negative agglutination, and ELISA test for brucella and magnetic resonance imaging confirmed the presence of a paravertebral abscess around the affected disc and tissue edema. Culture of needle aspiration of abscess tissue was positive for brucella melitensis.

Thalassemia paravertebral tumors and bone marrow scan

International Nuclear Information System (INIS)

Huglo, D.; Rose, C.; Deveaux, M.; Bauters, F.; Marchandise, X.

1995-01-01

Two first cousins with thalassemia and with a paravertebral mass had had an indium 111 chloride bone marrow scan. Result of scan influenced therapy: medical treatment in one case where an extramedullary erythropoiesis was confirmed, surgical treatment in the other case. The use of dual-isotope SPECT (indium 111 chloride, HDP -99 Tc) constitutes a contribution to the establishment of diagnosis of extramedullary erythropoiesis, giving to bone marrow scintigraphy a merited importance, avoiding the biopsy. (authors). 15 refs., 5 figs

Evidence of peripheral nerve blocks for cancer-related pain

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Klepstad, P; Kurita, G P; Mercadante, S

2015-01-01

The European Association for Palliative Care has initiated a comprehensive program to achieve an over-all review of the evidence of multiple cancer pain management strategies in order to extend the current guideline for treatment of cancer pain. The present systematic review analyzed the existing...... evidence of analgesic efficacy for peripheral nerve blocks in adult patients with cancer. A search strategy was elaborated with words related to cancer, pain, peripheral nerve and block. The search was performed in PubMed, EMBASE, and Cochrane for the period until February 2014. The number of abstracts...... retrieved was 155. No controlled studies were identified. Sixteen papers presented a total of 79 cases. The blocks applied were paravertebral blocks (10 cases), blocks in the head region (2 cases), plexus blocks (13 cases), intercostal blocks (43 cases) and others (11 cases). In general, most cases reported...

A Rare Cause of Chronic Low Back Pain: Paravertebral Hydatid Cyst

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Emel Atar

2016-05-01

            A 48-year-old man was admitted to our outpatient clinic with low back and right leg pain for 1 year. Lumbar spinal movements were painful and the pain radiated to his right posterolateral thigh. There was no weakness and numbness in both lower limbs but he had difficulty in load transfer during walking and therefore had ambulation difficulty. Tendon reflexes, and muscle strength examinations were normal. There was a slightly swelling at the right lumbar paravertebral region of spine by palpation. Routine blood tests were normal. Lumbar magnetic resonance examination (MRI was requested for clear evaluation of lower back structures. In MRI, we found a 8 × 5 cm multicystic mass at the level of L3–S3 located at the right paravertebral muscle. After this diagnosis, the patient began receiving albendazol.  Total cyst resection was performed and the histopathological examination confirmed hydatic cyst. 

The Use of Liposomal Bupivacaine in Erector Spinae Plane Block to Minimize Opioid Consumption for Breast Surgery: A Case Report.

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Kumar, Amanda; Hulsey, Alina; Martinez-Wilson, Hector; Kim, James; Gadsden, Jeff

2018-05-01

The erector spinae plane block is a novel interfascial plane block that can provide thoracic and abdominal analgesia. We describe a patient with opioid intolerance scheduled for breast surgery who received an erector spinae plane block with liposomal bupivacaine as well as a supplemental T1 paravertebral block resulting in profound analgesia throughout her postoperative course. This case report demonstrates that use of liposomal bupivacaine in the erector spinae plane block can be successful in providing extended duration postoperative analgesia and minimizing systemic opioid requirements.

Single-shot pectoral plane (PECs I and PECs II) blocks versus continuous local anaesthetic infusion analgesia or both after non-ambulatory breast-cancer surgery: a prospective, randomised, double-blind trial.

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O'Scanaill, P; Keane, S; Wall, V; Flood, G; Buggy, D J

2018-04-01

Pectoral plane blocks (PECs) are increasingly used in analgesia for patients undergoing breast surgery, and were recently found to be at least equivalent to single-shot paravertebral anaesthesia. However, there are no data comparing PECs with the popular practice of continuous local anaesthetic wound infusion (LA infusion) analgesia for breast surgery. Therefore, we compared the efficacy and safety of PECs blocks with LA infusion, or a combination of both in patients undergoing non-ambulatory breast-cancer surgery. This single-centre, prospective, randomised, double-blind trial analysed 45 women to receive either PECs blocks [levobupivacaine 0.25%, 10 ml PECs I and levobupivacaine 0.25%, 20 ml PECs II (PECs group); LA infusion catheter (levobupivacaine 0.1% at 10 ml h -1 for 24 h (LA infusion group); or both (PECs and LA infusion)]. The primary outcome measure was area under the curve of the pain verbal rating score whilst moving vs time (AUC) over 24 h. Secondary outcomes included total opioid consumption at 24 h. AUC moving was mean (SD) 71 (34) mm h -1 vs 58 (41) vs 23 (20) in PECs, LA infusion, and both, respectively; P=0.002. AUC at rest was also significantly lower in patients receiving both. The total 24 h opioid consumption [median (25-75%)] was 14 mg (9-26) vs 11 (8-24) vs 9 (5-11); P=0.4. No adverse events were observed. The combination of both pre-incisional PECs blocks and postoperative LA infusion provides better analgesia over 24 h than either technique alone after non-ambulatory breast-cancer surgery. NCT 03024697. Copyright © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.

Continuous celiac plexus block and spread of contrast media

International Nuclear Information System (INIS)

Itoh, Tatsushi; Kawabata, Masahiro; Suda, Takayuki; Koshimizu, Kenji

1987-01-01

A continuous celiac plexus block has been developed and is available for use. With this method, the drug can be repeatedly applied and the reproducibility of imaged findings is secured. It is possible to accurately judge the effect by the use of a local anesthetics before the injection of the neurolytics. Imaged findings at the celiac plexus block were classified into 4 types according to the pattern of CT images. Paticularly interesting is a finding that the contrast media injected in the retrocrural space for retrocrural splanchnic nerve block (RSB) permeates through the aortic hiatus as far as the area surrounding the celiac plexus and so-called transcrural celiac plexus block (TCB) takes place. Thus, it was found that the celiac plexus block so far used was a complex of RSB and TCB. (author)

Comparison of single-injection ultrasound-guided approach versus multilevel landmark-based approach for thoracic paravertebral blockade for breast tumor resection: a retrospective analysis at a tertiary care teaching institution

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Saran JS

2017-06-01

Full Text Available Jagroop Singh Saran,1 Amie L Hoefnagel,1 Kristin A Skinner,2 Changyong Feng,3 Daryl Irving Smith1 1Acute Pain Service, Department of Anesthesiology, University of Rochester School of Medicine and Dentistry, 2Department of Surgical Oncology, University of Rochester School of Medicine and Dentistry, University of Rochester Medical Center, 3Department of Biostatistics and Computational Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA Background: The role of thoracic paravertebral blockade (TPVB in decreasing opioid requirements in breast cancer surgery is well documented, and there is mounting evidence that this may improve survival and reduce the rate of malignancy recurrence following cancer-related mastectomy. We compared the two techniques currently in use at our institution, the anatomic landmark-guided (ALG multilevel versus an ultrasound-guided (USG single injection, to determine an optimal technique.Methods: We retrospectively reviewed records of patients who received TPVB from January 2013 to December 2014. Perioperative opioid use, post anesthesia care unit (PACU pain scores and length of stay, block performance, and complications were compared between the two groups.Results: We found no statistical difference between the two approaches in the studied outcomes. We did find that the number of times attending physicians in the ALG group took over the blocks from residents was significantly greater than that of the USG group (p=0.006 and more local anesthetic was used in the USG group (p=0.04.Conclusion: This study compared the ALG approach with the USG approach for patients undergoing mastectomy for breast cancer. Based on our observations, an attending physician is more likely to take over an ALG injection, and more local anesthetic is administered during USG single injection. Keywords: thoracic paravertebral block, regional anesthesia, mastectomy, breast cancer 

Merging Bottom-Up with Top-Down: Continuous Lamellar Networks and Block Copolymer Lithography

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Campbell, Ian Patrick

Block copolymer lithography is an emerging nanopatterning technology with capabilities that may complement and eventually replace those provided by existing optical lithography techniques. This bottom-up process relies on the parallel self-assembly of macromolecules composed of covalently linked, chemically distinct blocks to generate periodic nanostructures. Among the myriad potential morphologies, lamellar structures formed by diblock copolymers with symmetric volume fractions have attracted the most interest as a patterning tool. When confined to thin films and directed to assemble with interfaces perpendicular to the substrate, two-dimensional domains are formed between the free surface and the substrate, and selective removal of a single block creates a nanostructured polymeric template. The substrate exposed between the polymeric features can subsequently be modified through standard top-down microfabrication processes to generate novel nanostructured materials. Despite tremendous progress in our understanding of block copolymer self-assembly, continuous two-dimensional materials have not yet been fabricated via this robust technique, which may enable nanostructured material combinations that cannot be fabricated through bottom-up methods. This thesis aims to study the effects of block copolymer composition and processing on the lamellar network morphology of polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) and utilize this knowledge to fabricate continuous two-dimensional materials through top-down methods. First, block copolymer composition was varied through homopolymer blending to explore the physical phenomena surrounding lamellar network continuity. After establishing a framework for tuning the continuity, the effects of various processing parameters were explored to engineer the network connectivity via defect annihilation processes. Precisely controlling the connectivity and continuity of lamellar networks through defect engineering and

Continuous Thoracic Sympathetic Ganglion Block in Complex Regional Pain Syndrome Patients with Spinal Cord Stimulation Implantation

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EungDon Kim

2016-01-01

Full Text Available The sympathetic block is widely used for treating neuropathic pain such as complex regional pain syndrome (CRPS. However, single sympathetic block often provides only short-term effect. Moreover, frequent procedures for sympathetic block may increase the risk of complications. The use of epidural route may be limited by concern of infection in case of previous implantation of the spinal cord stimulation (SCS. In contrast, a continuous sympathetic block can be administered without such concerns. The continuous thoracic sympathetic block (TSGB has been used to treat the ischemic disease and other neuropathic conditions such as postherpetic neuralgia. We administered continuous thoracic sympathetic block using catheter in CRPS patients who underwent SCS implantations and achieved desirable outcomes. We believe a continuous sympathetic block is a considerable option before performing neurolysis or radiofrequency rhizotomy and even after SCS implantation.

Continuous PECS II block for postoperative analgesia in patients undergoing transapical transcatheter aortic valve implantation.

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Shakuo, Tomoharu; Kakumoto, Shinichi; Kuribayashi, Junya; Oe, Katsunori; Seo, Katsuhiro

2017-01-01

It has been reported that PECS II block can alleviate postoperative pain following transapical transcatheter aortic valve implantation (TA-TAVI). However, the effectiveness of continuous PECS II block with catheterization has not yet been reported on the postoperative pain in patients undergoing TA-TAVI. We experienced two cases of TA-TAVI who received PECS II block with catheterization to manage postoperative pain. In the first case, a bolus injection for intraoperative pain and subsequent catheterization were performed before the implantation. However, the patient developed severe pain postoperatively in spite of the continuous block due to displacement of the catheter. In the second case, a bolus injection and the catheterization for the continuous block were performed before and after the implantation, respectively, which provided high-quality pain control. Continuous PECS II block may be useful to control perioperative pain associated with TA-TAVI. The insertion of the catheter after the implantation could be useful to avoid its displacement during the surgery.

Analgesic effect of continuous femoral nerve block combined with infiltration anesthesia after total knee replacement

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Jian-Guo Tan

2016-01-01

Objective: To study the analgesic effect of continuous femoral nerve block combined with infiltration anesthesia after total knee replacement. Methods: Patients who received unilateral total knee replacement in our hospital from May 2012 to August 2015 were included for study and randomly divided into experimental group who received continuous femoral nerve block combined with infiltration anesthesia and control group who received continuous femoral nerve block, and then the co...

Comparison of Continuous Femoral Nerve Block with and Without Combined Sciatic Nerve Block after Total Hip Arthroplasty: A Prospective Randomized Study.

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Nishio, Shoji; Fukunishi, Shigeo; Fukui, Tomokazu; Fujihara, Yuki; Okahisa, Shohei; Takeda, Yu; Yoshiya, Shinichi

2017-06-23

In association with the growing interests in pain management, several modalities to control postoperative pain have been proposed and examined for the efficacy in the recent studies. Various modes of peripheral nerve block have been proposed and the effectiveness and safety have been examined for each of those techniques. We have described our clinical experiences, showing that continuous femoral nerve block could provide a satisfactory analgesic effect after total hip arthroplasty (THA) procedure. In this study, we compared the effectiveness and safety of continuous femoral nerve block with and without sciatic nerve blockade on pain control after THA. Forty patients scheduled for THA were included in the study and randomly divided into 2 groups. Postoperative analgesic measure was continuous femoral nerve block alone, while the identical regimen of continuous femoral nerve block was combined with sciatic nerve block. The amount of postoperative pain was evaluated in the immediate postoperative period, 6 hours, and 12 hours after surgery. Moreover, postoperative complications as well as requirement of supplemental analgesics during the initial 12 hours after surgery were reviewed in the patient record. The obtained study results showed that the supplemental sciatic nerve blockade provided no significant effect on arrival at the postoperative recovery room, while the NRS pain score was significantly reduced by the combined application of sciatic nerve blockade at 6 and 12 hours after surgery. In the investigation of postoperative analgesiarelated complications, no major complication was encountered without significant difference in complication rate between the groups.

Effects of adding dexamethasone or ketamine to bupivacaine for ultrasound-guided thoracic paravertebral block in patients undergoing modified radical mastectomy: A prospective randomized controlled study

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Mona Blough El Mourad

2018-01-01

Full Text Available Background and Aims: Pain after modified radical mastectomy (MRM has been successfully managed with thoracic paravertebral block (TPVB. The purpose of this study was to evaluate the effect of adding dexamethasone or ketamine as adjuncts to bupivacaine in TPVB on the quality of postoperative analgesia in participants undergoing MRM. Methods: This prospective randomised controlled study enrolled ninety adult females scheduled for MRM. Patients were randomised into three groups (30 each to receive ultrasound-guided TPVB before induction of general anaesthesia. Group B received bupivacaine 0.5% + 1 ml normal saline, Group D received bupivacaine 0.5% + 1 ml dexamethasone (4 mg and Group K received bupivacaine 0.5% + 1 ml ketamine (50 mg. Patients were observed for 24 h postoperatively to record time to first analgesic demand as a primary outcome, pain scores, total rescue morphine consumption and incidence of complications. Results: Group K had significantly longer time to first analgesic demand than group D and control group (18.0 ± 6.0, 10.3 ± 4.5 and 5.3 ± 3.1 hours respectively; P = 0.0001. VAS scores were significantly lower in group D and group K compared to control group at 6h and 12 h postoperative (p 0.0001 and 0.0001 respectively while group K had lower VAS at 18 hours compared to other two groups (P = 0.0001. Control group showed the highest mean 24 h opioid consumption (8.9 ± 7.9 mg compared to group D and group K (3.60 ± 6.92 and 2.63 ± 5.24 mg, P = 0.008,0.001 respectively. No serious adverse events were observed. Conclusion: Ketamine 50 mg or dexamethasone 4 mg added to bupivacaine 0.5% in TPVB for MRM prolonged the time to first analgesic request with no serious side effects.

Transthoracic Arteriovenous Graft Repair With the Pectoralis (PECS) II Nerve Block for Primary Intraoperative Anesthesia and Postoperative Analgesia: A Case Report.

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Farkas, Gabriel; Weber, Garret; Miller, Jonathon; Xu, Jeff

2018-05-07

The PECS II nerve block is a relatively new regional anesthetic technique that targets the medial and lateral pectoral nerves, as well as the lateral cutaneous branches of the intercostal nerves. It has been described for surgical cases involving the breast, as an adjunct or alternative to neuraxial or paravertebral techniques. This case report describes the first successful use of the PECS II nerve block placed using ultrasound guidance as the primary anesthetic and postoperative analgesic in a non-breast-related chest wall surgery.

Extrapleural paravertebral CT guided fine needle biopsy of subcarinal lymph nodes

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Tantawy, Wahid H., E-mail: tantawyw@yahoo.com [Radiology Department, Faculty of Medicine, Ain Shams University, Egypt Abbassyia square, Cairo (Egypt); El-Gemeie, Emad H. [Pathology Department, National Cancer Institute, Fom El Khalige Faculty of Medicine, Cairo University (Egypt); Ibrahim, Ahmed S., E-mail: asibrahima@gmail.com [Radiology Department, Faculty of Medicine, Ain Shams University, Egypt Abbassyia square, Cairo (Egypt); Mohamed, Mona A. [Radiology Department, Faculty of Medicine, Ain Shams University, Egypt Abbassyia square, Cairo (Egypt)

2012-10-15

Purpose: To report our experience in CT guided extrapleural paravertebral subcarinal lymph biopsy using a thin 25 gauge (25 G) thin needle without the need of injection of saline to widen the mediastinum. Materials and methods: Biopsy was performed using a 25 G needle which was advanced lateral to the vertebral body between the endothoracic fascia and the parietal pleura to gain access to subcarinal lymph nodes. One hundred and forty one patients were included in the study (74 females, 57 males). No artificial widening of the mediastinum using saline injection was required. The study was performed in the presence of a cytopathologist; sensitivity and specificity rates were calculated. Complications were documented for each case especially for pneumothorax and haemorrhage. Results: Cytopathological diagnosis was reached in all cases. All re-aspirations were done in the same session to reach a primary diagnosis at the time of the biopsy. Imunophenotyping study was done in 94 cases to confirm the primary diagnosis and to classify the malignant lesions. No pneumothorax was encountered. Small haematomas were noted in 5 cases (3.5%). Cytopathology showed a sensitivity of 97.2% and specificity of 100%. By adding immunophenotyping a 100% sensitivity and specificity was achieved. Conclusion: Fine needle aspiration cytology (FNAC) using a 25 gauge needle for subcarinal lymph nodes via a percutaneous extrapleural paravertebral CT guided approach is a safe, minimally invasive, and tolerable procedure yielding a high sensitivity and specificity rates without the need of artificial widening.

Extrapleural paravertebral CT guided fine needle biopsy of subcarinal lymph nodes

International Nuclear Information System (INIS)

Tantawy, Wahid H.; El-Gemeie, Emad H.; Ibrahim, Ahmed S.; Mohamed, Mona A.

2012-01-01

Purpose: To report our experience in CT guided extrapleural paravertebral subcarinal lymph biopsy using a thin 25 gauge (25 G) thin needle without the need of injection of saline to widen the mediastinum. Materials and methods: Biopsy was performed using a 25 G needle which was advanced lateral to the vertebral body between the endothoracic fascia and the parietal pleura to gain access to subcarinal lymph nodes. One hundred and forty one patients were included in the study (74 females, 57 males). No artificial widening of the mediastinum using saline injection was required. The study was performed in the presence of a cytopathologist; sensitivity and specificity rates were calculated. Complications were documented for each case especially for pneumothorax and haemorrhage. Results: Cytopathological diagnosis was reached in all cases. All re-aspirations were done in the same session to reach a primary diagnosis at the time of the biopsy. Imunophenotyping study was done in 94 cases to confirm the primary diagnosis and to classify the malignant lesions. No pneumothorax was encountered. Small haematomas were noted in 5 cases (3.5%). Cytopathology showed a sensitivity of 97.2% and specificity of 100%. By adding immunophenotyping a 100% sensitivity and specificity was achieved. Conclusion: Fine needle aspiration cytology (FNAC) using a 25 gauge needle for subcarinal lymph nodes via a percutaneous extrapleural paravertebral CT guided approach is a safe, minimally invasive, and tolerable procedure yielding a high sensitivity and specificity rates without the need of artificial widening

An unusual case of lumbar paravertebral miositis ossificans mimicking muscular skeletal tumor.

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Zoccali, C; Chichierchia, G; Covello, R

2013-12-01

Several lesions have clinical and radiological characteristics mimicking muscular skeletal tumor. Myositis ossificans usually presents a typical pattern making biopsy unnecessary; nevertheless, in rare cases, neoplasm must be ruled out. Biopsy is often sufficient to allow a diagnosis and a correct related treatment, but, unfortunately, sometimes it may lead to erroneous treatment. We report an unusual case of a lumbar paravertebral mass that had an MRI aspect similar to a chondrosarcoma, a histology pattern based on biopsy compatible with neurinoma and a definitive diagnosis of myosistis ossificans.

Ultrasound-guided continuous suprascapular nerve block for adhesive capsulitis: one case and a short topical review

DEFF Research Database (Denmark)

Neimann, Jens Dupont Børglum; Bartholdy, Anne; Hautopp, H

2011-01-01

We present a case with an ultrasound-guided (USG) placement of a perineural catheter beneath the transverse scapular ligament in the scapular notch to provide a continuous block of the suprascapular nerve (SSN). The patient suffered from a severe and very painful adhesive capsulitis of the left...... shoulder secondary to an operation in the same shoulder conducted 20 weeks previously for impingement syndrome and a superior labral anterior-posterior tear. Following a new operation with capsular release, the placement of a continuous nerve block catheter subsequently allowed for nearly pain-free low...... impact passive and guided active mobilization by the performing physiotherapist for three consecutive weeks. This case and a short topical review on the use of SSN block in painful shoulder conditions highlight the possibility of a USG continuous nerve block of the SSN as sufficient pain management...

TRUE Block Scale Continuation Project. Final Report

Energy Technology Data Exchange (ETDEWEB)

Andersson, Peter; Byegaard, Johan [Geosigma AB (Sweden); Billaux, Daniel [Itasca Consultants SA (France); Cvetkovic, Vladimir [Royal Inst. of Technology, Stockholm (Sweden); Dershowitz, William; Doe, Thomas [Golder Associates Inc. (United States); Hermanson, Jan [Golder Associates AB (Sweden); Poteri, Antti [VTT (Finland); Tullborg, Eva-Lena [Terralogica AB (Sweden); Winberg, Anders [Conterra AB (SE)] (ed.)

2007-03-15

The TRUE Block Scale project was carried out during 1996-2002. This project focused on site characterisation and building of hydrostructural and microstructural models, sorbing tracer experiments in single structures and networks of structures over distances ranging between 1 and 100 m and also involved a unified application of various model approaches for modelling the in situ experiments. In 2002, ANDRA, Posiva, JNC and SKB decided to pursue some remaining issues in the so-called TRUE Block Scale Continuation project (TRUE BS2). The specific objectives of BS2 can be summarised as: 'Improve understanding of transport pathways at the block scale, including assessment of effects of geology and geometry, macrostructure and microstructure'. In order to cater to addressing the stated objective a series of hypotheses were formulated which explored the importance of geological information for predicting transport and retention and the possible differences between transport and retention between transport paths dominated by faults and those dominated by non-fault fractures (background fractures). In the process, prospects for carrying out experiments in fracture networks over longer distances (c 20-100 m) were explored. It was identified that experiments with sorbing tracers over these distances were prohibitive because of the time frames involved and the projected low mass recoveries. Instead the experimental locus was shifted to a geological structure previously not investigated by tracer tests in the TRUE Block Scale experiments. The lower immobile zone retention material properties assigned to background fractures compared to those assigned to the fault-type Structure 19 have been verified by means of back-calculations. The evaluated Type 1 flow path (Structure 19, Flow path I) retention material properties, as expressed by {kappa} parameter, are one order of magnitude higher than for the background fracture flow path. This finding is consistent with the

Successful emergency pain control for posterior rib fractures with ultrasound-guided erector spinae plane block.

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Luftig, Josh; Mantuani, Daniel; Herring, Andrew A; Dixon, Brittany; Clattenburg, Eben; Nagdev, Arun

2017-12-28

The Eastern Association for the Surgery of Trauma and Trauma Anesthesiology Society Guidelines recommend prompt and effective multimodal analgesia for rib fractures that combines regional anesthesia (RA) techniques with pharmacotherapy to treat pain, optimize pulmonary function, and reduce opioid related complications. However, RA techniques such as epidurals and paravertebral blocks, are generally underutilized or unavailable for emergency department (ED) patients. The recently described serratus anterior plane block (SAPB) is a promising technique, but failures with posterior rib fractures have been observed. The erector spinae plane block (ESPB) is conceptually similar to the SAPB, but targets the posterior thorax making it likely more effective for ED patients with posterior rib fractures. Our initial experience demonstrates consistent success with the ESPB for traumatic posterior rib fracture analgesia. Herein, we present the first description of the ESPB utilized in the ED. Copyright © 2017 Elsevier Inc. All rights reserved.

Continuous intercostal nerve blockade for rib fractures: ready for primetime?

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Truitt, Michael S; Murry, Jason; Amos, Joseph; Lorenzo, Manuel; Mangram, Alicia; Dunn, Ernest; Moore, Ernest E

2011-12-01

Providing analgesia for patients with rib fractures continues to be a management challenge. The objective of this study was to examine our experience with the use of a continuous intercostal nerve block (CINB). Although this technique is being used, little data have been published documenting its use and efficacy. We hypothesized that a CINB would provide excellent analgesia, improve pulmonary function, and decrease length of stay (LOS). Consecutive adult blunt trauma patients with three or more unilateral rib fractures were prospectively studied over 24 months. The catheters were placed at the bedside in the extrathoracic, paravertebral location, and 0.2% ropivacaine was infused. Respiratory rate, preplacement (PRE) numeric pain scale (NPS) scores, and sustained maximal inspiration (SMI) lung volumes were determined at rest and after coughing. Parameters were repeated 60 minutes after catheter placement (POST). Hospital LOS comparison was made with historical controls using epidural analgesia. Over the study period, 102 patients met inclusion criteria. Mean age was 69 (21-96) years, mean injury severity score was 14 (9-16), and the mean number of rib fractures was 5.8 (3-10). Mean NPS improved significantly (PRE NPS at rest = 7.5 vs. POST NPS at rest = 2.6, p pain control, and shortens LOS in patients with rib fractures.

Analgesic effect of continuous femoral nerve block combined with infiltration anesthesia after total knee replacement

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Jian-Guo Tan

2016-06-01

Full Text Available Objective: To study the analgesic effect of continuous femoral nerve block combined with infiltration anesthesia after total knee replacement. Methods: Patients who received unilateral total knee replacement in our hospital from May 2012 to August 2015 were included for study and randomly divided into experimental group who received continuous femoral nerve block combined with infiltration anesthesia and control group who received continuous femoral nerve block, and then the contents of postoperative serum pain-promoting-related mediators, painsuppressing-related mediators and pain-related signal molecules were detected. Results: Serum CGRP, PS, Hist, 5-HT, AM and BK contents of experimental group were significantly lower than those of control group, AEA, β-EP, RvE1, LXA4 and LXB4 contents were significantly higher than those of control group, and P2X2, P2X7, P2X3, P2X4, P2Y1, P2Y2, P2Y4, P2Y6, P2Y 13, P2Y14, p38MAPK and PI3K contents were significantly lower than those of control group. Conclusions: Continuous femoral nerve block combined with infiltration anesthesia after total knee replacement can increase the generation of pain-suppressing mediators, decrease the generation of pain-promoting mediators and achieve more exact analgesic effect.

Post-operative bilateral continuous ultrasound-guided transversus abdominis plane block versus continuous local anaesthetic wound infusion in patients undergoing abdominoplasty

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Eman Ramadan Salama

2018-01-01

Full Text Available Background and Aims: Transversus abdominis plane (TAP block and continuous local anaesthetic wound infusion are used as part of multimodal analgesia to treat postoperative pain after lower abdominal surgeries. The aim of this randomised controlled study was to assess the efficacy of the two techniques and compare the two in patients undergoing abdominoplasty. Methods: Ninety female patients undergoing abdominoplasty were allocated to receive continuous wound infusion with saline (control group, GC, n = 30, continuous bilateral TAP block with 0.25% levobupivacaine (group GT, n = 30, or continuous wound infusion with 0.25% levobupivacaine (group GW, n = 30. The primary end-point was morphine requirement in the first 48 h. Numerical rating scale (NRS at rest and during movement, time to first morphine dose and time to first ambulation were recorded. Results: Morphine requirement in the first 48 h was significantly higher in GC than GW and GT (61.9 ± 12.8, 21.5 ± 9.5, and 18.9 ± 8.1 mg, respectively; P = 0.001, but GW and GT were comparable (P = 0.259. NRS was significantly higher in GC during movement in the first 24 h. GW and GT showed significantly longer time to first morphine dose (6.5 ± 1.7 and 8.9 ± 1.4 h, respectively, vs. 1.2 ± 0.3 h in GC and significantly shorter time to first ambulation (7.8 ± 3.1 and 6.9 ± 3.4 h, respectively, vs. 13.2 ± 4.9 h in GC (P = 0.001. Conclusion: Continuous bilateral ultrasound-guided TAP block and continuous local anaesthetic wound infusion significantly decreased total morphine consumption in the first 48 h compared to placebo; however, both treatment techniques were comparable.

Lumbar paravertebral blockade as intractable pain management method in palliative care.

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Zaporowska-Stachowiak, Iwona; Kotlinska-Lemieszek, Aleksandra; Kowalski, Grzegorz; Kosicka, Katarzyna; Hoffmann, Karolina; Główka, Franciszek; Luczak, Jacek

2013-01-01

Optimal symptoms control in advanced cancer disease, with refractory to conventional pain treatment, needs an interventional procedure. This paper presents coadministration of local anesthetic (LA) via paravertebral blockade (PVB) as the alternative to an unsuccessful subcutaneous fentanyl pain control in a 71-year old cancer patient with pathological fracture of femoral neck, bone metastases, and contraindications to morphine. Bupivacaine in continuous infusion (0.25%, 5 mL · hour(-1)) or in boluses (10 mL of 0.125%-0.5% solution), used for lumbar PVB, resulted in pain relief, decreased demand for opioids, and led to better social interactions. The factors contributing to an increased risk of systemic toxicity from LA in the patient were: renal impairment; heart failure; hypoalbuminemia; hypocalcemia; and a complex therapy with possible drug-drug interactions. These factors were taken into consideration during treatment. Bupivacaine's side effects were absent. Coadministered drugs could mask LA's toxicity. Elevated plasma α1-acid glycoprotein levels were a protective factor. To evaluate the benefit-risk ratio of the PVB treatment in boluses and in constant infusion, bupivacaine serum levels were determined and the drug plasma half-lives were calculated. Bupivacaine's elimination was slower when administered in constant infusion than in boluses (t½ = 7.80 hours versus 2.64 hours). Total drug serum concentrations remained within the safe ranges during the whole treatment course (22.9-927.4 ng mL(-1)). In the case presented, lumbar PVB with bupivacaine in boluses (≤ 137.5 mg · 24 hours(-1)) was an easy to perform, safe, effective method for pain control. Bupivacaine in continuous infusion (≤150 mg · 12 hours(-1)) had an acceptable risk-benefits ratio, but was ineffective.

Role of ultrasound-guided continuous brachial plexus block in the management of neonatal ischemia in upper limb

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Vrushali C Ponde

2012-01-01

Full Text Available Neonatal upper limb ischemia due to accidental arterial damage remains a major concern, which can lead to devastating complications if untreated. The primary objective of this case report is to emphasize the role of continuous infraclavicular brachial plexus block, the issues related with block performance in an ischemic hand, and the importance of ultrasound guidance in this particular case scenario. A 1.1 kg infant suffered from distal forearm ischemia due to accidental arterial damage, which was treated with brachial plexus block. An ultrasound-guided single shot block with 0.5 mL/kg of 0.25% bupivacaine was followed by ultrasound-guided catheter placement in the target area. A continuous infusion of 0.03% of bupivacaine at the rate of 0.5 mL/kg/hr (approx. 0.15 mg/kg/h of bupivacaine was administered for 36 h. This treatment resulted in reversal of ischemia. Permanent ischemic damage was eventually confined to the tips of 4 fingers. We conclude that ultrasound-guided continuous infraclavicular block has a therapeutic role to play in the treatment of hand ischemia due to arterial damage and subsequent arterial spasm in neonates with added benefits.

The ultrasound-guided retrolaminar block: volume-dependent injectate distribution

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Damjanovska M

2018-02-01

Full Text Available Marija Damjanovska,1 Tatjana Stopar Pintaric,1,2 Erika Cvetko,2 Kamen Vlassakov3 1Clinical Department of Anesthesiology and Intensive Therapy, University Medical Centre Ljubljana, Ljubljana, Slovenia; 2Institute of Anatomy, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia; 3Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA Purpose: The ultrasound-guided retrolaminar block is one of the newer and simpler alternatives to the traditional, often technically challenging, paravertebral (PV block. Its feasibility, safety, and efficacy have already been clinically demonstrated in patients with multiple rib fractures using higher volumes of local anesthetic, when compared with the traditional approach. The primary aim of this observational anatomical study was to assess the spread of local anesthetic from the retrolaminar injection point to the PV space and its volume dependence. Second, we assessed the incidence of epidural and contralateral PV spread in the both groups.Methods: Ten fresh porcine cadavers were randomized into 2 groups (n=5 each to receive ultrasound-guided retrolaminar injections at Th4-Th5 level with either 10 mL (low-volume group or 30 mL (high-volume group of 2% lidocaine and methylene blue mixture. After the procedure, the cadavers were dissected and frozen. Cross-section cuts (~1 cm thick were performed to evaluate the injectate spread.Results: In the high-volume group, injectate spread from the retrolaminar to the PV space was observed in all specimens (5 out of 5; 100%, while in the low-volume group, no apparent spread to the PV space was found (0 out of 5; 0%. No epidural or contralateral PV spread was observed in any of the specimens.Conclusion: Following ultrasound-guided retrolaminar injections in fresh porcine cadavers, injectate spread from the retrolaminar tissue plane to the PV space is strongly volume dependent

Ablation of lumbar sympathetic ganglia by absolute ethanol injection and paravertebral catheter placement under CT guidance: evaluation of the efficacy

International Nuclear Information System (INIS)

Xu Hua; Xiong Yuanchang; Shao Chengwei; Zuo Changjing; Sheng Jing; Tian Jianming

2009-01-01

Objective: To evaluate the ablation of lumbar sympathetic ganglia by using single injection of absolute ethanol and retaining a paravertebral catheter under CT guidance for the treatment of lower extremity ischemia. Methods: Single absolute ethanol injection of L2 sympathetic ganglia was done in 25 cases (group B), single absolute ethanol injection of L2 sympathetic ganglia together with placement of a paravertebral catheter at L3 was carried out in 23 cases (group BT). All the procedures were performed under CT guidance. Three days after the procedure, the pain severity of the lower limbs was evaluated based on VAS method. If the patient in group BT still had a VAS score ≥4 on the third day, 3 ml of 1% lidocaine was infected via the retained catheter in the prone position. If VAS score became ≤3 at 5 min after the injection, additional 5 ml of ethanol was given through the catheter. The pain severity was evaluated again one week later. VAS score, analgesic dose and temperature of lower limbs were recorded. Results: One week after the procedure the excellent rate and effective rate for group B were 32% and 80% respectively, while for group BT were 60.9% and 95.7% respectively, with a significant difference between two groups (P<0.01). Conclusion: For the ablation of lumbar sympathetic ganglia the combination of single absolute ethanol injection with paravertebral catheter placement under CT guidance is superior to the single absolute ethanol injection. This technique is more individual with better results and is more likely to be accepted by the patients. (authors)

Dyskospondylitis and paravertebral abscesses in a calf

International Nuclear Information System (INIS)

Testoni, S.

2006-01-01

A case of progressive spastic paraparesis due to a dyskospondylitis at the level of T9-T10 is described in a four-month old Holstein female calf. The calf was recumbent, but bright, alert and willing to suckle. Despite repeated attempts, the calf was not able to assume the sternal recumbency. The radiological findings were decisive for the in life diagnosis. Spinal radiography of the thoraco-lumbar region revealed lysis and collapse of T9 and T10 vertebral bodies; irregular proliferative new bone was evident. Lumbo-sacral myelography showed a narrowing and dorsal displacement of the ventral contrast column at the same spinal level, indicating a severe ventral extradural compression of the spinal cord. At the level of the thoracic cavity, a 20 x 15 cm diameter opacity extending ventrally to T8-T13 and caudo-dorsally to the heart was also evident. At gross necroscopy, two approximately 15 cm diameter encapsulated paravertebral abscesses were evident in the thoracis cavity just below the spinal column. A pure culture of Fusobacterium necrophorum was obtained from them. A saggital section of the spine showed an erosive suppurative process of T9 and T10 vertebral bodies that provoked the compression of the thoracic tract of the spinal cord [it

Sympathetic Blocks Provided Sustained Pain Relief in a Patient with Refractory Painful Diabetic Neuropathy

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Jianguo Cheng

2012-01-01

Full Text Available The sympathetic nervous system has been implicated in pain associated with painful diabetic neuropathy. However, therapeutic intervention targeted at the sympathetic nervous system has not been established. We thus tested the hypothesis that sympathetic nerve blocks significantly reduce pain in a patient with painful diabetic neuropathy who has failed multiple pharmacological treatments. The diagnosis of small fiber sensory neuropathy was based on clinical presentations and confirmed by skin biopsies. A series of 9 lumbar sympathetic blocks over a 26-month period provided sustained pain relief in his legs. Additional thoracic paravertebral blocks further provided control of the pain in the trunk which can occasionally be seen in severe diabetic neuropathy cases, consequent to extensive involvement of the intercostal nerves. These blocks provided sustained and significant pain relief and improvement of quality of life over a period of more than two years. We thus provided the first clinical evidence supporting the notion that sympathetic nervous system plays a critical role in painful diabetic neuropathy and sympathetic blocks can be an effective management modality of painful diabetic neuropathy. We concluded that the sympathetic nervous system is a valuable therapeutic target of pharmacological and interventional modalities of treatments in painful diabetic neuropathy patients.

31 CFR 595.301 - Blocked account; blocked property.

Science.gov (United States)

2010-07-01

... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY TERRORISM SANCTIONS REGULATIONS General Definitions § 595.301 Blocked account; blocked property. The terms blocked account and blocked...

A randomized comparison of ropivacaine 0.1% and 0.2% for continuous interscalene block after shoulder surgery.

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Yang, Chun Woo; Jung, Sung Mee; Kang, Po Soon; Kwon, Hee Uk; Cho, Choon Kyu; Lee, Younsuk; Kim, Chul Woung; Kim, Su Young

2013-03-01

The optimal concentration of ropivacaine for continuous interscalene block after shoulder surgery is currently unknown. Fifty-six patients received a perineural infusion of either ropivacaine 0.1% or 0.2% for 48 hours after shoulder surgery. We assessed pain scores as primary end points and supplemental analgesia, ropivacaine consumption, motor block, side effects, and patient satisfaction as secondary end points. Pain scores were not statistically different during the infusion periods; however, supplemental analgesia consumption was higher in the group receiving ropivacaine 0.1% during the first 24 hours (64% vs 28%, P = 0.022). Other secondary end points were statistically inconclusive. These results suggest that ropivacaine 0.2% provides more effective analgesia than ropivacaine 0.1% during the first 24 hours for continuous interscalene block after shoulder surgery.

31 CFR 594.301 - Blocked account; blocked property.

Science.gov (United States)

2010-07-01

... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY GLOBAL TERRORISM SANCTIONS REGULATIONS General Definitions § 594.301 Blocked account; blocked property. The terms blocked account and...

An Unusual Case of Plasmablastic Lymphoma Presenting as Paravertebral Mass Evaluated by {sup 18}F-FDG PET/CT

Energy Technology Data Exchange (ETDEWEB)

Treglia, Giorgio; Paone, Gaetano; Stathis, Anastasios; Ceriani, Luca; Giovanella, Luca [Oncology Institute of Southern Switzerland, Bellinzona (Switzerland)

2014-03-15

A 60-year-old man underwent radiological investigations due to the onset of back pain. Computed tomography (CT) and magnetic resonance imaging (MRI) showed the presence of a paravertebral mass located ahead the body of the third thoracic vertebra. Based on these findings the patient underwent biopsy of the paravertebral mass, which showed the presence of a plasmablastic lymphoma. Therefore, the patient underwent fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography ({sup 18}F-FDG PET/CT) for staging. Before {sup 18}F-FDG injection, the patient had fasted for at least 6 h; at the time of the radiopharmaceutical injection he presented glucose blood levels corresponding to 98 mg/dl. Images were acquired 1 h after intravenous injection of 280 MBq of {sup 18}F-FDG according to the body mass index. PET images were interpreted visually and semiquantitatively by using the maximal standardized uptake value (SUVmax). {sup 18}F-FDG PET/CT showed moderate radiopharmaceutical uptake corresponding to the paravertebral lesion (SUVmax 3.3) and diffuse uptake in the skeleton suspicious for bone marrow neoplastic involvement, with more evident hypermetabolic areas in the left scapula (SUVmax 3.7), right sixth rib (SUVmax 3.5), and left iliac bone (SUVmax 3.4) (Fig. 1). Subsequent bone marrow biopsy confirmed the bone marrow infiltration by plasmablastic cells. Based on these findings, a final diagnosis of plasmablastic lymphoma with bone marrow involvement was performed and the patient was addressed to chemotherapy. Plasmablastic lymphoma is a rare CD20-negative large-cell lymphoma with plasmablastic features occurring primarily in HIV or Epstein-Barr virus positive individuals. Distinguishing this tumor from myeloma could be challenging. The most frequent site of presentation is the oral cavity, whereas extraoral localizations of plasmablastic lymphoma are considered to be very rare and they should be differentiated from extraosseous localization of

Influences of continuous femoral nerve block on knee function and quality of life in patients following total knee arthroplasty.

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Wang, Fen; Zhou, Yingjie; Sun, Jiajun; Yang, Chunxi

2015-01-01

Continuous femoral nerve block (CFNB), guided by ultrasound combined nerve stimulations, offers advantages for both sides and provides effective postoperative analgesia after total knee arthroplasty (TKA). The objective of this study was to evaluate the medium-term impact of continuous femoral nerve block on knee function and quality of life in patients following TKA. This was a follow-up study. Total 168 adult patients scheduled for elective TKA were randomly allocated to receive postoperative continuous femoral nerve block guided by ultrasound combined nerve stimulator (group CFNB, n = 82) or patient-controlled epidural analgesia (group PCEA, n = 86). Quality of life, knee function, patient satisfaction, pain medication and associated adverse effects were compared at 1, 3, 6, and 12 months postoperatively. Quality of life was assessed using the Medical Outcomes Study Short Form-36 Health Survey (MOS SF-36), and clinical results were assessed using the Hospital for Special Surgery (HSS) Knee Scoring System. Patient satisfaction scores were divided into four categories. A total of 162 patients completed the 12-month follow-up. The CFNB group patients had significantly improved SF-36 scores and physical function at 1 month postoperatively (P quality of life in patients at one month postoperatively. Continuous femoral nerve block is a good choice for postoperative analgesia after TKA.

Lumbar paravertebral blockade as intractable pain management method in palliative care

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Zaporowska-Stachowiak I

2013-09-01

Full Text Available Iwona Zaporowska-Stachowiak,1,2 Aleksandra Kotlinska-Lemieszek,3 Grzegorz Kowalski,3 Katarzyna Kosicka,4 Karolina Hoffmann,5 Franciszek Główka,4 Jacek Łuczak2 1Department of Pharmacology, 2Palliative Medicine In-patient Unit, University Hospital of Lord’s Transfiguration, 3Department of Palliative Care, 4Department of Physical Pharmacy and Pharmacokinetics, 5Department of Internal Medicine, Metabolic Disorders and Arterial Hypertension, Poznan University of Medical Sciences, Poznan, Poland Abstract: Optimal symptoms control in advanced cancer disease, with refractory to conventional pain treatment, needs an interventional procedure. This paper presents coadministration of local anesthetic (LA via paravertebral blockade (PVB as the alternative to an unsuccessful subcutaneous fentanyl pain control in a 71-year old cancer patient with pathological fracture of femoral neck, bone metastases, and contraindications to morphine. Bupivacaine in continuous infusion (0.25%, 5 mL · hour-1 or in boluses (10 mL of 0.125%–0.5% solution, used for lumbar PVB, resulted in pain relief, decreased demand for opioids, and led to better social interactions. The factors contributing to an increased risk of systemic toxicity from LA in the patient were: renal impairment; heart failure; hypoalbuminemia; hypocalcemia; and a complex therapy with possible drug–drug interactions. These factors were taken into consideration during treatment. Bupivacaine’s side effects were absent. Coadministered drugs could mask LA’s toxicity. Elevated plasma α1-acid glycoprotein levels were a protective factor. To evaluate the benefit-risk ratio of the PVB treatment in boluses and in constant infusion, bupivacaine serum levels were determined and the drug plasma half-lives were calculated. Bupivacaine’s elimination was slower when administered in constant infusion than in boluses (t½ = 7.80 hours versus 2.64 hours. Total drug serum concentrations remained within the safe

Examining the Role of Perioperative Nerve Blocks in Hip Arthroscopy: A Systematic Review.

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Kay, Jeffrey; de Sa, Darren; Memon, Muzammil; Simunovic, Nicole; Paul, James; Ayeni, Olufemi R

2016-04-01

This systematic review examined the efficacy of perioperative nerve blocks for pain control after hip arthroscopy. The databases Embase, PubMed, and Medline were searched on June 2, 2015, for English-language studies that reported on the use of perioperative nerve blocks for hip arthroscopy. The studies were systematically screened and data abstracted in duplicate. Nine eligible studies were included in this review (2 case reports, 2 case series, 3 non-randomized comparative studies, and 2 randomized controlled trials). In total, 534 patients (534 hips), with a mean age of 37.2 years, who underwent hip arthroscopy procedures were administered nerve blocks for pain management. Specifically, femoral (2 studies), fascia iliaca (2 studies), lumbar plexus (3 studies), and L1 and L2 paravertebral (2 studies) nerve blocks were used. All studies reported acceptable pain scores after the use of nerve blocks, and 4 studies showed significantly lower postoperative pain scores acutely with the use of nerve blocks over general anesthesia alone. The use of nerve blocks also resulted in a decrease in opioid consumption in 4 studies and provided a higher level of patient satisfaction in 2 studies. No serious acute complications were reported in any study, and long-term complications from lumbar plexus blocks, such as local anesthetic system toxicity (0.9%) and long-term neuropathy (2.8%), were low in incidence. The use of perioperative nerve blocks provides effective pain management after hip arthroscopy and may be more effective in decreasing acute postoperative pain and supplemental opioid consumption than other analgesic techniques. Level IV, systematic review of Level I to Level IV studies. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Delayed vocal fold paralysis after continuous interscalene level brachial plexus block with catheter placement: a case report.

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Gollapalli, Lakshman; McKelvey, George; Wang, Hong

2014-08-01

We report an incident of delayed onset of true vocal fold paralysis with continuous interscalene brachial plexus block. A 51 year old woman underwent left shoulder manipulation and lysis of adhesions with fluoroscopy and general anesthesia. An interscalene brachial plexus block was performed and a catheter with a continuous infusion pump was placed for postoperative pain control. Following hospital discharge, approximately 8 hours after the initial catheter bolus the patient developed hoarseness, dysphagia, and dyspnea, secondary to left vocal fold palsy. The patient was admitted for observation and the catheter was discontinued with no intubation required. By the next morning, the patient's dysphagia and dyspnea had resolved and her hoarseness improved. Copyright © 2014. Published by Elsevier Inc.

ISSN 2073-9990 East Cent. Afr. J. surg

African Journals Online (AJOL)

Hp 630 Dual Core

Block Following Breast Cancer Surgery in a Nigerian Hospital. A Rukewe1 ... mastectomy with axillary clearance under general anaesthesia with paravertebral block and 15 ... prolonged postoperative pain relief for unilateral breast operations.

Erector spinae plane block may aid weaning from mechanical ventilation in patients with multiple rib fractures: Case report of two cases

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Amar Nandhakumar

2018-01-01

Full Text Available Uncontrolled pain in patients with rib fracture leads to atelectasis and impaired cough which can progress to pneumonia and respiratory failure necessitating mechanical ventilation. Of the various pain modalities, regional anaesthesia (epidural and paravertebral is better than systemic and oral analgesics. The erector spinae plane block (ESPB is a new modality in the armamentarium for the management of pain in multiple rib fractures, which is simple to perform and without major complications. We report a case series where ESPB helped in weaning the patients from mechanical ventilation. Further randomised controlled studies are warranted in comparing their efficacy in relation to other regional anaesthetic techniques.

Four quadrant transversus abdominis plane block and continuous transversus abdominis plane analgesia: a 3-year prospective audit in 124 patients.

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Niraj, G; Kelkar, Aditi; Hart, Elaine; Kaushik, Vipul; Fleet, Danny; Jameson, John

2015-11-01

Transversus abdominis plane (TAP) blocks have been reported to be an effective method of providing analgesia after abdominal surgery. To perform a prospective audit on the effectiveness of a novel technique of providing continuous transversus abdominis plane (TAP) analgesia in patients undergoing emergency and elective abdominal surgery. Prospective single center audit over a 3-year period. University hospital. One hundred twenty-four American Society of Anesthesiologists I to IV adult patients presenting for elective as well as emergency abdominal surgery in whom epidural analgesia was contraindicated or refused. Four quadrant TAP blocks and continuous TAP analgesia. Numerical rating scale pain scores at rest and on coughing, nausea scores, satisfaction scores, complications, frequency of analgesia failure, therapeutic failure with continuous TAP analgesia and opioid consumption. One hundred twenty-four patients who received continuous TAP analgesia were audited. This included 34 patients for elective open surgery, 36 patients for emergency laparotomy, and 54 patients who underwent elective laparoscopic colorectal surgery. Surgical incision was within the dermatomal limit of the block in 70% of the patients (88/124). Therapeutic failure with the technique was 10%. Frequency of analgesic failure over the 48-hour period was none in 39% and below 5 episodes in 57%. Four quadrant transversus abdominis plane blocks and continuous TAP analgesia is an effective technique for providing postoperative analgesia after abdominal surgery. It has the potential to be used as a sole analgesic technique when the surgical incision is within its dermatomal limit. Copyright © 2015 Elsevier Inc. All rights reserved.

Use of the cumulative sum method (CUSUM) to assess the learning curves of ultrasound-guided continuous femoral nerve block.

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Kollmann-Camaiora, A; Brogly, N; Alsina, E; Gilsanz, F

2017-10-01

Although ultrasound is a basic competence for anaesthesia residents (AR) there is few data available on the learning process. This prospective observational study aims to assess the learning process of ultrasound-guided continuous femoral nerve block and to determine the number of procedures that a resident would need to perform in order to reach proficiency using the cumulative sum (CUSUM) method. We recruited 19 AR without previous experience. Learning curves were constructed using the CUSUM method for ultrasound-guided continuous femoral nerve block considering 2 success criteria: a decrease of pain score>2 in a [0-10] scale after 15minutes, and time required to perform it. We analyse data from 17 AR for a total of 237 ultrasound-guided continuous femoral nerve blocks. 8/17 AR became proficient for pain relief, however all the AR who did more than 12 blocks (8/8) became proficient. As for time of performance 5/17 of AR achieved the objective of 12minutes, however all the AR who did more than 20 blocks (4/4) achieved it. The number of procedures needed to achieve proficiency seems to be 12, however it takes more procedures to reduce performance time. The CUSUM methodology could be useful in training programs to allow early interventions in case of repeated failures, and develop competence-based curriculum. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Continuous transversus abdominis plane block vs intermittent bolus for analgesia after abdominal surgery: a randomized trial

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Rao Kadam V

2017-07-01

Full Text Available Vasanth Rao Kadam,1 Roelof M Van Wijk,1 John L Moran,2 Shantan Ganesh,3 A Kumar,1 Rajesh Sethi,1 Patricia Williams2,4 1Department of Anaesthesia, The Queen Elizabeth Hospital, School of Medicine, University of Adelaide, Adelaide, SA, 2Intensive Care Unit, The Queen Elizabeth Hospital, School of Medicine, University of Adelaide, Adelaide, SA, 3Department of Surgery, The Queen Elizabeth Hospital, School of Medicine, University of Adelaide, Adelaide, SA, 4Department of Epidemiology and Preventive Medicine, School Public Health and Preventive Medicine, Australian and New Zealand Intensive Care Research Centre, Monash University, Melbourne, VIC, Australia Background: Continuous and intermittent bolus techniques of transversus abdominis plane (TAP blocks have been used for analgesia after abdominal surgery. Although both are effective, there are no studies comparing them. The aim of this study is to compare analgesia and cost-effectiveness between these groups.Methods: After obtaining ethical approval, 20 American Society of Anesthesiologists ASA grade I to III patients undergoing elective abdominal surgery were recruited with 10 patients allocated to each arm. Bilateral ultrasound-guided TAP blocks were performed with an initial bolus of 0.5% ropivacaine 20 mL per side, followed by catheter insertion. After surgery, the continuous infusion group received 0.2% ropivacaine 8 mL/hour on each side and the intermittent bolus group received doses of 0.2% ropivacaine 20 mL per side every 8 hours for 48 hours. Both groups received intravenous fentanyl patient-controlled analgesia and regular oral paracetamol. Parameters recorded included numerical rating scores for pain and post-operative analgesic consumption at baseline (time 0 and at 1 hour, 1 day and 2 days post-operatively. The duration of catheter insertion, complications, patient satisfaction and information regarding costs were also recorded. Patient satisfaction was assessed utilizing a 4-point �

Opioid-sparing effects of the thoracic interfascial plane blocks: A meta-analysis of randomized controlled trials.

Science.gov (United States)

Singh, Preet Mohinder; Borle, Anuradha; Kaur, Manpreet; Trikha, Anjan; Sinha, Ashish

2018-01-01

Thoracic interfascial plane blocks and modification (PECS) have recently gained popularity for analgesic potential during breast surgery. We evaluate/consolidate the evidence on opioid-sparing effect of PECS blocks in comparison with conventional intravenous analgesia (IVA) and paravertebral block (PVB). Prospective, randomized controlled trials comparing PECS block to conventional IVA or PVB in patients undergoing breast surgery published till June 2017 were searched in the medical database. Comparisons were made for 24-h postoperative morphine consumption and intraoperative fentanyl-equivalent consumption. Final analysis included nine trials (PECS vs. IVA 4 trials and PECS vs. PVB 5 trials). PECS block showed a decreased intraoperative fentanyl consumption over IVA by 49.20 mcg (95% confidence interval [CI] =42.67-55.74) ( I 2 = 98.47%, P consumption with PECS block was lower than IVA by 7.66 mg (95% CI being 6.23-9.10) ( I 2 = 63.15, P < 0.001) but was higher than PVB group by 1.26 mg (95% CI being 0.91-1.62) ( I 2 = 99.53%, P < 0.001). Two cases of pneumothorax were reported with PVB, and no complication was reported in any other group. Use of PECS block and its modifications with general anesthesia for breast surgery has significant opioid-sparing effect intraoperatively and during the first 24 h after surgery. It also has higher intraoperative opioid-sparing effect when compared to PVB. During the 1 st postoperative day, PVB has slightly more morphine sparing potential that may however be associated with higher complication rates. The present PECS block techniques show marked interstudy variations and need standardization.

Opioid Usage During Admission in Hip Fracture Patients-The Effect of the Continuous Femoral Nerve Block

DEFF Research Database (Denmark)

Helsø, Ida; Jantzen, Christopher; Lauritzen, Jes Bruun

2016-01-01

INTRODUCTION: The aim of this study was to investigate whether there was a difference in opioid usage during admission for hip fracture patients with continuous femoral nerve block (cFNB) when compared to patients nonfemoral nerve block (nFNB). METHODS AND MATERIALS: Patients were identified from...... the local database on all hip fracture patients admitted to Bispebjerg University Hospital, Denmark. Four hundred fifty-six hip fracture patients were included during the period September 2008 to October 2010. RESULTS: Three hundred sixty-six hip fracture patients had cFNB. The mean time with cFNB was 3...

Low cost continuous femoral nerve block for relief of acute severe cancer related pain due to pathological fracture femur

Directory of Open Access Journals (Sweden)

Rachel Cherian Koshy

2010-01-01

Full Text Available Pathological fractures in cancer patient cause severe pain that is difficult to control pharmacologically. Even with good pain relief at rest, breakthrough and incident pain can be unmanageable. Continuous regional nerve blocks have a definite role in controlling such intractable pain. We describe two such cases where severe pain was adequately relieved in the acute phase. Continuous femoral nerve block was used as an efficient, cheap and safe method of pain relief for two of our patients with pathological fracture femur. This method was proved to be quite efficient in decreasing the fracture-related pain and improving the level of well being.

Comparison of the Effect of Continuous Femoral Nerve Block and Adductor Canal Block after Primary Total Knee Arthroplasty.

Science.gov (United States)

Seo, Seung Suk; Kim, Ok Gul; Seo, Jin Hyeok; Kim, Do Hoon; Kim, Youn Gu; Park, Beyoung Yun

2017-09-01

This study aimed to compare the effects of femoral nerve block and adductor canal block on postoperative pain, quadriceps strength, and walking ability after primary total knee arthroplasty. Between November 2014 and February 2015, 60 patients underwent primary total knee arthroplasty. Thirty patients received femoral nerve block and the other 30 received adductor canal block for postoperative pain control. Before spinal anesthesia, the patients received nerve block via a catheter (20 mL 0.75% ropivacaine was administered initially, followed by intermittent bolus injection of 10 mL 0.2% ropivacaine every 6 hours for 3 days). The catheters were maintained in the exact location of nerve block in 24 patients in the femoral nerve block group and in 19 patients in the adductor canal block group. Data collection was carried out from these 43 patients. To evaluate postoperative pain control, the numerical rating scale scores at rest and 45° flexion of the knee were recorded. To evaluate quadriceps strength, manual muscle testing was performed. Walking ability was assessed using the Timed Up and Go test. We also evaluated analgesic consumption and complications of peripheral nerve block. No significant intergroup difference was observed in the numerical rating scale scores at rest and 45° flexion of the knee on postoperative days 1, 2, 3, and 7. The adductor canal block group had significantly greater quadriceps strength than did the femoral nerve block group, as assessed by manual muscle testing on postoperative days 1, 2, and 3. The 2 groups showed no difference in walking ability on postoperative day 1, but on postoperative days 2, 3, walking ability was significantly better in the adductor canal block group than in the femoral nerve block group. No significant intergroup difference was observed in analgesic consumption. The groups showed no difference in postoperative pain control. Adductor canal block was superior to femoral nerve block in preserving quadriceps

Ultrasound-guided continuous phrenic nerve block for persistent hiccups.

NARCIS (Netherlands)

Renes, S.H.; Geffen, G.J. van; Rettig, H.C.; Gielen, M.J.M.; Scheffer, G.J.

2010-01-01

BACKGROUND: Phrenic nerve block can be performed and repeated if necessary for persistent hiccups, when conservative and pharmacological treatment is unsuccessful. We report the first description of an in-plane ultrasound (US)-guided phrenic nerve block (PhNB) with a catheter, after US investigation

Urinary retention in unilateral total knee arthroplasty: comparison between continuous epidural analgesia and single-shot femoral nerve block

International Nuclear Information System (INIS)

Khan, A.A.; Khan, R.I.

2018-01-01

To compare the frequency of urinary retention and requirement of bladder catheterization in patients undergoing toatal knee arthroplasty while receiving either continuous epidural analgesia or single-shot femoral nerve block. Study Design: Randomized controlled study. Place and Duration of Study:Operating Rooms of Aga Khan University Hospital, Karachi, from January 2014 to January 2015. Methodology:Patients were randomized in two groups of 30 each, i.e. epidural group (group E) or femoral nerve block group (group F). Baseline parameters were recorded. Postoperatively, patients were followed for upto 24 hours to collect the data regarding urinary retention. Final outcome was taken at 24 hours postoperatively. Data was analyzed to compare the frequency of urinary retention between the two groups. Results:The average age of the patients was 59.58 +-5.85 years. There were 28 (46.7%) male and 32 (53.3%) female patients. Frequency of urinary retention was significantly high in Group E than Group F (46.7% vs. 6.7%; p=0.0005). Conclusion: Single-shot femoral nerve block offers a more favorable profile in terms of postoperative urinary retention when compared to continuous epidural analgesia. (author)

Mesoporous Bragg reflectors: block-copolymer self-assembly leads to building blocks with well defined continuous pores and high control over optical properties

KAUST Repository

Guldin, S.

2011-08-19

Mesoporous distributed Bragg re ectors (MDBRs) exhibit porosity on the sub-optical length scale. This makes them ideally suited as sensing platforms in biology and chemistry as well as for light management in optoelectronic devices. Here we present a new fast forward route for the fabrication of MDBRs which relies on the self-assembling properties of the block copolymer poly(isoprene-block -ethylene oxide) (PI-b -PEO) in combination with sol-gel chemistry. The interplay between structure directing organic host and co-assembled inorganic guest allows the ne tuning of refractive index in the outcome material. The refractive index dierence between the high and low porosity layer can be as high as 0.4, with the optical interfaces being well dened. Following a 30 min annealing protocol after each layer deposition enables the fast and reliable stacking of MDBRs which exhibit a continuous TiO2 network with large accessible pores and high optical quality.

Continuous vs. blocks of physiotherapy for motor development in children with cerebral palsy and similar syndromes: A prospective randomized study.

Science.gov (United States)

Brunner, Anne-Louise; Rutz, Erich; Juenemann, Stephanie; Brunner, Reinald

2014-12-01

To determine whether physiotherapy is more effective when applied in blocks or continuously in children with cerebral palsy (CP). A prospective randomized cross-over design study compared the effect of regular physiotherapy (baseline) with blocks of physiotherapy alternating with no physiotherapy over one year. Thirty-nine institutionalized children with CP and clinically similar syndromes (6-16 years old, Gross Motor Function Classification Scale II-IV) were included. During the first scholastic year, group A received regular physiotherapy, group B blocks of physiotherapy and vice versa in the second year. The Gross Motor Function Measure 66 (GMFM-66) was the outcome measure. Thirteen children in each group completed the study. GMFM-66 improved (p Physiotherapy may be more effective when provided regularly rather than in blocks.

Continuous Adductor Canal Blocks

DEFF Research Database (Denmark)

Monahan, Amanda M; Sztain, Jacklynn F; Khatibi, Bahareh

2016-01-01

on cutaneous knee sensation in volunteers. METHODS: Bilateral adductor canal catheters were inserted in 24 volunteers followed by ropivacaine 0.2% administration for 8 hours. One limb of each subject was assigned randomly to a continuous infusion (8 mL/h) or automated hourly boluses (8 m...

Temporal structure of first-year courses and success at course exams: comparison of traditional continual and block delivery of anatomy and chemistry courses.

LENUS (Irish Health Repository)

Salopek, Daniela

2012-01-31

AIM: To evaluate students\\' academic success at delivered in a traditional continual course, spread over the two semesters, or in alternating course blocks. METHOD: We analyzed the data on exam grades for Anatomy and Chemistry courses in the first year of the curriculum for academic year 2001\\/02, with the traditional continual delivery of the courses (n=253 for chemistry and n=243 for anatomy), and academic year 2003\\/04, with block delivery of the courses (n=255 for Chemistry and n=260 for Anatomy). Grades from the final examination were analyzed only for students who sat the exam at the first available exam term and passed the course. For the Anatomy block course, grades at 2 interim written tests and 2 parts of the final exam (practical stage exam and oral exam) in each block were analyzed for students who passed all interim tests and the final exam. RESULTS: There were no differences between two types of course delivery in the number of students passing the final examination at first attempt. There was a decrease in passing percentage for the two Anatomy block course student groups in 2003\\/04 (56% passing students in block 1 vs 40% in block 2, P=0.014). There was an increase in the average grades from 2001\\/02 to 2003\\/04 academic year due to an increase in Chemistry grades (F1,399=18.4, P<0.001, 2 x 2 ANOVA). There was no effect of the sequence of their delivery (F1,206=1.8, P=0.182, 2 x 2 ANOVA). There was also a significant difference in grades on interim assessments of Anatomy when it was delivered in the block format (F3,85=28.8, P<0.001, between-within subjects 2 x 4 ANOVA). CONCLUSIONS: The type of course delivery was not associated with significant differences in student academic success in Anatomy and Chemistry courses in the medical curriculum. Students can successfully pass these courses when they are delivered either in a continual, whole year format or in a condensed time format of a course block, regardless of the number and type of

Continuous Infraclavicular Block for Forearm Amputation After Being Bitten by a Saltwater Crocodile (Crocodylus Porosus: A Case Report

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Chin-Hsi Chiu

2009-08-01

Full Text Available Two important issues after a complete right forearm amputation are replantation and ongoing pain management. There are no reports of successful forearm replantation as a consequence of a crocodile bite. Here, we discuss our pain management in a case of complete forearm amputation after a bite from a saltwater crocodile (Crocodylus porosus, which necessitated six further operations to achieve successful replantation. Continuous infraclavicular brachial plexus block was effective for acute pain control in this case. We strongly recommend performing the block with an indwelling catheter under ultrasound guidance for higher accuracy and safety.

Efficacy of arthroscopically placed pain catheter adjacent to the suprascapular nerve (continuous arthroscopically assisted suprascapular nerve block following arthroscopic rotator-cuff repair

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Yamakado K

2014-05-01

Full Text Available Kotaro YamakadoDepartment of Orthopaedics, Fukui General Hospital, Fukui, JapanBackground: Rotator-cuff surgery is well recognized to be a painful procedure.Objectives: The purpose of this study was to examine the effectiveness of an arthroscopically placed perineural catheter at the scapular notch to provide a continuous block of the suprascapular nerve (continuous arthroscopically assisted suprascapular nerve block [ca-SSNB] following arthroscopic rotator-cuff repair (ARCR.Materials and methods: This level II, prospective, randomized, controlled trial without postoperative blinding included 40 patients, who had a 48-hour pain pump, with 0.2% ropivacaine infusion and a continuous rate of 3 mL/hour, placed via an arthroscopically placed catheter following ARCR with arthroscopic release of the superior transverse ligament: 21 patients had a ca-SSNB, and 19 patients had a continuous subacromial bursal block (SAB. The visual analog scale (at 6 hours and on the first, second, and third postoperative days and the total number of additional pain-reduction attempts during the 3 postoperative days were calculated.Results: The respective visual analog scale scores (mm obtained from the ca-SSNB and SAB groups were 62.4 and 67.6 (P=0.73 before surgery, 9.1 and 19.4 (P=0.12 at 6 hours after surgery, 24.4 and 44.6 (P=0.019 on the first postoperative day, 19.4 and 40.4 (P=0.0060 on the second postoperative day, and 18.5 and 27.8 (P=0.21 on the third postoperative day. Total additional pain-reduction attempts recorded for the ca-SSNB and SAB groups during the 3 postoperative days were 0.3 times and 1.2 times (P=0.0020, respectively.Conclusion: ca-SSNB was highly effective in controlling postoperative pain after ARCR.Keywords: shoulder, rotator cuff tear, postoperative pain control, continuous suprascapular nerve block, arthroscopic rotator cuff repair

Paravertebral Well-Differentiated Liposarcoma with Low-Grade Osteosarcomatous Component: Case Report with 11-Year Follow-Up, Radiological, Pathological, and Genetic Data, and Literature Review

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Nicolas Macagno

2017-01-01

Full Text Available Despite being one of the most frequent soft-tissue sarcomas, well-differentiated liposarcoma has never been reported near the spine. The authors present the case of a 67-year-old man with progressive history of back pain. Physical examination revealed a mass located within the right paravertebral muscles. MR and CT imaging showed a heavily ossified central mass surrounded by a peripheral fatty component. No connection with the underlying bone was detected on imagery and during surgery. After surgical resection, histopathological examination revealed a tumor harboring combined features of well-differentiated liposarcoma and low-grade osteosarcoma. Tumor cells displayed overexpression of MDM2, CDK4, and P16 by immunohistochemistry and CGH revealed amplification of 12q13-15 as the only genetic imbalance. MDM2 FISH analysis was performed but was inconclusive. The pathological, immunohistochemical, and genetic features, the differential diagnoses, and the therapeutic management of this unusual tumor are discussed. No complementary treatment was performed initially. Following first treatment, two recurrences occurred 6 and 9 years later, both displaying histological features similar to the first occurrence. Radiotherapy was started after the second recurrence. Follow-up shows no evidence of disease 11 years after initial diagnosis. This case was unusual due to the paravertebral location of the tumor and its divergent differentiation.

The analgesic efficacy of continuous transversus abdominis plane block in renal transplant recipients

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Beena Kandarp Parikh

2015-01-01

Full Text Available Background and Aims: Transversus abdominis plane (TAP block is suitable for operations where parietal pain is a major cause of pain. Renal transplant recipients are ideally suited to gain maximum benefit from TAP block as the incision classically involves the lower abdomen. This study was conducted to evaluate the analgesic efficacy of continuous TAP block in transplant recipients. Material and Methods: In a prospective double-blind study, 40 chronic renal failure patients undergoing open renal transplant were randomly divided into two groups. At the end of surgery during closure, a multiorifice epidural catheter was placed in TAP plane. Study group (Group S received Inj bupivacaine bolus 1 mg/kg (0.25% followed by infusion 0.25 mg/kg (0.125% through the catheter, whereas control group (Group C received normal saline through the catheter. Inj pentazocine (0.3 mg/kg was given as rescue analgesic at visual analogue score (VAS > 3 in any group at rest or on movement. The analgesic efficacy was judged by VAS, time of first rescue analgesic, and total analgesic consumption in 24 h. Results: Patients in Group S had significant lower VAS scores, longer time to first rescue analgesic (270 ± 347.96 vs. 42.85 ± 32.27 min and lower pentazocine consumption (9.75 ± 13.95 vs. 56.42 ± 12.46 mg in 24 h. There was significant sedation in Group C. Conclusion: The TAP catheter technique for postoperative pain control after renal transplant has proved to be effective in relieving the postoperative pain after renal transplant with less pentazocine requirement and less sedation.

Ultrasound and nerve stimulator guided continuous femoral nerve block analgesia after total knee arthroplasty: a multicenter randomized controlled study

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Fen Wang

2015-02-01

Full Text Available BACKGROUND AND OBJECTIVES: Postoperative analgesia is crucial for early functional excise after total knee arthroplasty. To investigate the clinical efficacy of ultrasound and nerve stimulator guided continuous femoral nerve block analgesia after total knee arthroplasty. METHODS: 46 patients with ASA grade I-III who underwent total knee arthroplasty received postoperative analgesia from October 2012 to January 2013. In 22 patients, ultrasound and nerve stimulator guided continuous femoral nerve block were performed for analgesia (CFNB group; in 24 patients, epidural analgesia was done (PCEA group. The analgesic effects, side effects, articular recovery and complications were compared between two groups. RESULTS: At 6 h and 12 h after surgery, the knee pain score (VAS score during functional tests after active exercise and after passive excise in CFNB were significantly reduced when compared with PCEA group. The amount of parecoxib used in CFNB patients was significantly reduced when compared with PCEA group. At 48 h after surgery, the muscle strength grade in CFNB group was significantly higher, and the time to ambulatory activity was shorter than those in PCEA group. The incidence of nausea and vomiting in CFNB patients was significantly reduced when compared with PCEA group. CONCLUSION: Ultrasound and nerve stimulator guided continuous femoral nerve block provide better analgesia at 6 h and 12 h, demonstrated by RVAS and PVAS. The amount of parecoxib also reduces, the incidence of nausea and vomiting decreased, the influence on muscle strength is compromised and patients can perform ambulatory activity under this condition.

Efficacy and Safety of Ketamine Added to Local Anesthetic in Modified Pectoral Block for Management of Postoperative Pain in Patients Undergoing Modified Radical Mastectomy.

Science.gov (United States)

Othman, Ahmed H; El-Rahman, Ahmad M Abd; El Sherif, Fatma

2016-01-01

Breast surgery is an exceedingly common procedure with an increased incidence of acute and chronic pain. Pectoral nerve block is a novel peripheral nerve block alternative to neuro-axial and paravertebral blocks for ambulatory breast surgeries. This study aims to compare the analgesic efficacy and safety of modified Pecs block with ketamine plus bupivacaine versus bupivacaine in patients undergoing breast cancer surgery. A randomized, double-blind, prospective study. Academic medical center. This study is registered at www.clinicaltrials.gov under number: (NCT02620371) after approval by the ethics committee of South Egypt Cancer Institute, Assuit University, Assuit, Egypt. Sixty patients aged 18 - 60 years scheduled for modified radical mastectomy were enrolled and randomly assigned into 2 groups (30 patients each): Control group patients were given ultrasound-guided, Pecs block with 30 mL of 0.25% bupivacaine only. Ketamine group patients were given ultrasound-guided, Pecs block with 30 mL of 0.25% bupivacaine plus ketamine hydrochloride (1 mg/kg). Patients were followed up for 48 hours postoperatively for vital signs, VAS score, first request of rescue analgesia and total morphine consumption, sedation score, and side effects. Ketamine plus bupivacaine in Pecs block compared to bupivacaine alone prolonged the mean time of first request of analgesia (18.25 ± 1.98), (12.56 ± 2.64), respectively (P 0.05). This study is limited by its sample size. The addition of ketamine to modified Pecs block prolonged the time to first request of analgesia and reduced total opioid consumption without serious side effects in patients who underwent a modified radical mastectomy. Ketamine, bupivacaine, pecs block, postoperative, pain, breast cancer.

Continuous Femoral Nerve Block versus Intravenous Patient Controlled Analgesia for Knee Mobility and Long-Term Pain in Patients Receiving Total Knee Replacement: A Randomized Controlled Trial

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Lihua Peng

2014-01-01

Full Text Available Objectives. To evaluate the comparative analgesia effectiveness and safety of postoperative continuous femoral nerve block (CFNB with patient controlled intravenous analgesia (PCIA and their impact on knee function and chronic postoperative pain. Methods. Participants were randomly allocated to receive postoperative continuous femoral nerve block (group CFNB or intravenous patient controlled analgesia (group PCIA. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC scores for knee and incidence of chronic postoperative pain at 3, 6, and 12 months postoperatively were compared. postoperative pain and salvage medication at rest or during mobilization 24 hours, 48 hours, and 7 days postoperatively were also recorded. Results. After discharge from the hospital and rehabilitation of joint function, patients in group CFNB reported significantly improved knee flexion and less incidence of chronic postoperative pain at 3 months and 6 months postoperatively (P<0.05. Analgesic rescue medications were significantly reduced in patients receiving CFNB (P<0.001 and P=0.031, resp.. Conclusion. With standardized rehabilitation therapy, continuous femoral nerve block analgesia reduced the incidence of chronic postoperative pain, improved motility of replaced joints, and reduced the dosages of rescue analgesic medications, suggesting a recovery-enhancing effect of peripheral nerve block analgesia.

Comparison of analgesic interventions for traumatic rib fractures: a systematic review and meta-analysis.

Science.gov (United States)

Peek, Jesse; Smeeing, Diederik P J; Hietbrink, Falco; Houwert, Roderick M; Marsman, Marije; de Jong, Mirjam B

2018-02-06

Many studies report on outcomes of analgesic therapy for (suspected) traumatic rib fractures. However, the literature is inconclusive and diverse regarding the management of pain and its effect on pain relief and associated complications. This systematic review and meta-analysis summarizes and compares reduction of pain for the different treatment modalities and as secondary outcome mortality during hospitalization, length of mechanical ventilation, length of hospital stay, length of intensive care unit stay (ICU) and complications such as respiratory, cardiovascular, and/or analgesia-related complications, for four different types of analgesic therapy: epidural analgesia, intravenous analgesia, paravertebral blocks and intercostal blocks. PubMed, EMBASE and CENTRAL databases were searched to identify comparative studies investigating epidural, intravenous, paravertebral and intercostal interventions for traumatic rib fractures, without restriction for study type. The search strategy included keywords and MeSH or Emtree terms relating blunt chest trauma (including rib fractures), analgesic interventions, pain management and complications. A total of 19 papers met our inclusion criteria and were finally included in this systematic review. Significant differences were found in favor of epidural analgesia for the reduction of pain. No significant differences were observed between epidural analgesia, intravenous analgesia, paravertebral blocks and intercostal blocks, for the secondary outcomes. Results of this study show that epidural analgesia provides better pain relief than the other modalities. No differences were observed for secondary endpoints like length of ICU stay, length of mechanical ventilation or pulmonary complications. However, the quality of the available evidence is low, and therefore, preclude strong recommendations.

49 CFR 236.804 - Signal, block.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Signal, block. 236.804 Section 236.804 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Signal, block. A roadway signal operated either automatically or manually at the entrance to a block. ...

Paravertebral block as a sole technique for the anaesthetic ...

African Journals Online (AJOL)

Kinsley Enohumah

2016-04-11

Apr 11, 2016 ... anaesthetic management of a ME patient who underwent breast cancer surgery. ... some minor discomfort in the axillary area. Since the patient ... postoperative analgesia without increased toxicity in healthy adults.

21 CFR 882.5070 - Bite block.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bite block. 882.5070 Section 882.5070 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Therapeutic Devices § 882.5070 Bite block. (a) Identification. A bite block...

Isostatic compression of buffer blocks. Middle scale

International Nuclear Information System (INIS)

Ritola, J.; Pyy, E.

2012-01-01

Manufacturing of buffer components using isostatic compression method has been studied in small scale in 2008 (Laaksonen 2010). These tests included manufacturing of buffer blocks using different bentonite materials and different compression pressures. Isostatic mould technology was also tested, along with different methods to fill the mould, such as vibration and partial vacuum, as well as a stepwise compression of the blocks. The development of manufacturing techniques has continued with small-scale (30 %) blocks (diameter 600 mm) in 2009. This was done in a separate project: Isostatic compression, manufacturing and testing of small scale (D = 600 mm) buffer blocks. The research on the isostatic compression method continued in 2010 in a project aimed to test and examine the isostatic manufacturing process of buffer blocks at 70 % scale (block diameter 1200 to 1300 mm), and the aim was to continue in 2011 with full-scale blocks (diameter 1700 mm). A total of nine bentonite blocks were manufactured at 70 % scale, of which four were ring-shaped and the rest were cylindrical. It is currently not possible to manufacture full-scale blocks, because there is no sufficiently large isostatic press available. However, such a compression unit is expected to be possible to use in the near future. The test results of bentonite blocks, produced with an isostatic pressing method at different presses and at different sizes, suggest that the technical characteristics, for example bulk density and strength values, are somewhat independent of the size of the block, and that the blocks have fairly homogenous characteristics. Water content and compression pressure are the two most important properties determining the characteristics of the compressed blocks. By adjusting these two properties it is fairly easy to produce blocks at a desired density. The commonly used compression pressure in the manufacturing of bentonite blocks is 100 MPa, which compresses bentonite to approximately

Isostatic compression of buffer blocks. Middle scale

Energy Technology Data Exchange (ETDEWEB)

Ritola, J.; Pyy, E. [VTT Technical Research Centre of Finland, Espoo (Finland)

2012-01-15

Manufacturing of buffer components using isostatic compression method has been studied in small scale in 2008 (Laaksonen 2010). These tests included manufacturing of buffer blocks using different bentonite materials and different compression pressures. Isostatic mould technology was also tested, along with different methods to fill the mould, such as vibration and partial vacuum, as well as a stepwise compression of the blocks. The development of manufacturing techniques has continued with small-scale (30 %) blocks (diameter 600 mm) in 2009. This was done in a separate project: Isostatic compression, manufacturing and testing of small scale (D = 600 mm) buffer blocks. The research on the isostatic compression method continued in 2010 in a project aimed to test and examine the isostatic manufacturing process of buffer blocks at 70 % scale (block diameter 1200 to 1300 mm), and the aim was to continue in 2011 with full-scale blocks (diameter 1700 mm). A total of nine bentonite blocks were manufactured at 70 % scale, of which four were ring-shaped and the rest were cylindrical. It is currently not possible to manufacture full-scale blocks, because there is no sufficiently large isostatic press available. However, such a compression unit is expected to be possible to use in the near future. The test results of bentonite blocks, produced with an isostatic pressing method at different presses and at different sizes, suggest that the technical characteristics, for example bulk density and strength values, are somewhat independent of the size of the block, and that the blocks have fairly homogenous characteristics. Water content and compression pressure are the two most important properties determining the characteristics of the compressed blocks. By adjusting these two properties it is fairly easy to produce blocks at a desired density. The commonly used compression pressure in the manufacturing of bentonite blocks is 100 MPa, which compresses bentonite to approximately

Predictability of blocking

International Nuclear Information System (INIS)

Tosi, E.; Ruti, P.; Tibaldi, S.; D'Andrea, F.

1994-01-01

Tibaldi and Molteni (1990, hereafter referred to as TM) had previously investigated operational blocking predictability by the ECMWF model and the possible relationships between model systematic error and blocking in the winter season of the Northern Hemisphere, using seven years of ECMWF operational archives of analyses and day 1 to 10 forecasts. They showed that fewer blocking episodes than in the real atmosphere were generally simulated by the model, and that this deficiency increased with increasing forecast time. As a consequence of this, a major contribution to the systematic error in the winter season was shown to derive from the inability of the model to properly forecast blocking. In this study, the analysis performed in TM for the first seven winter seasons of the ECMWF operational model is extended to the subsequent five winters, during which model development, reflecting both resolution increases and parametrisation modifications, continued unabated. In addition the objective blocking index developed by TM has been applied to the observed data to study the natural low frequency variability of blocking. The ability to simulate blocking of some climate models has also been tested

Comparison of efficacy of continuous epidural block and pulsed radiofrequency to the dorsal root ganglion for management of pain persisting beyond the acute phase of herpes zoster.

Directory of Open Access Journals (Sweden)

Eung Don Kim

Full Text Available There is little evidence regarding the effectiveness of intervention methods in the treatment of zoster-related pain (ZAP after the acute phase of zoster. Generally, if ZAP remains after more than 180 days from its onset, the likelihood of pain reduction is very low; this condition is considered as a "well established" post-herpetic neuralgia (PHN. Although the clinical efficacy of intrathecal steroid injection and spinal cord stimulation (SCS for ZAP management has been reported, these interventions are not widely used due to inherent disadvantages. Continuous epidural block is widely used in clinical practice, and the effectiveness of pulsed radiofrequency (PRF to the dorsal root ganglion (DRG in the treatment of ZAP already has been reported.The purpose of this study was to compare the clinical efficacy of continuous epidural block and DRG PRF beyond acute phase of zoster, bur before PHN was well established (from 30 days to180 days after zoster onset.Retrospective comparative study.A total of 42 medical records were analyzed. Patients were divided into two groups according to the type of procedure utilized: continuous epidural block (continuous epidural group and DRG PRF (PRF group. The clinical efficacy of the procedure was evaluated using a numeric rating scale (NRS and the medication dose before and 1 to 6 months after the procedure.There was a significant decrease in the NRS value with time in both groups. However, this decrease was more significant in the PRF group than in the continuous epidural group. The medication doses decreased significantly in the PRF group over time, but not in the continuous epidural group. The rate of clinically meaningful PHN (NRS≥3 was also lower in the PRF group than in the continuous epidural group.This study revealed that DRG PRF was more effective than a continuous epidural block in treating ZAP after the acute phase of zoster. A neuromodulation method such as DRG PRF may be a useful option for

Ultrasound-guided continuous interscalene block: the influence of local anesthetic background delivery method on postoperative analgesia after shoulder surgery: a randomized trial.

Science.gov (United States)

Hamdani, Mehdi; Chassot, Olivier; Fournier, Roxane

2014-01-01

Automated bolus delivery has recently been shown to reduce local anesthetic consumption and improve analgesia, compared with continuous infusion, in continuous sciatic and epidural block. However, there are few data on the influence of local anesthetic delivery method on local anesthetic consumption following interscalene blockade. This randomized, double-blind trial was designed to determine whether hourly automated perineural boluses (4 mL) of local anesthesia delivered with patient-controlled pro re nata (PRN, on demand) boluses would result in a reduction in total local anesthesia consumption during continuous interscalene blockade after shoulder surgery compared with continuous perineural infusion (4 mL/h) plus patient-controlled PRN boluses. One hundred one patients undergoing major shoulder surgery under general anesthesia with ultrasound-guided continuous interscalene block were randomly assigned to receive 0.2% ropivacaine via interscalene end-hole catheter either by continuous infusion 4 mL/h (n = 50) or as automated bolus 4 mL/h (n = 51). Both delivery methods were combined with 5 mL PRN boluses of 0.2% ropivacaine with a lockout time of 30 minutes. Postoperative number of PRN boluses, 24- and 48-hour local anesthetic consumption, pain scores, rescue analgesia (morphine), and adverse events were recorded. There were no significant differences in either the number of PRN ropivacaine boluses or total 48 hour local anesthetic consumption between the groups (18.5 [11-25.2] PRN boluses in the continuous infusion group vs 17 [8.5-29] PRN boluses in the automated bolus group). Postoperative pain was similar in both groups; on day 2, the median average pain score was 4 (2-6) in the continuous infusion group versus 3 (2-5) in the automated bolus group (P = 0.54). Nor were any statistically significant intergroup differences observed with respect to morphine rescue, incidence of adverse events, or patient satisfaction. In continuous interscalene blockade under

Block Play: Practical Suggestions for Common Dilemmas

Science.gov (United States)

Tunks, Karyn Wellhousen

2009-01-01

Learning materials and teaching methods used in early childhood classrooms have fluctuated greatly over the past century. However, one learning tool has stood the test of time: Wood building blocks, often called unit blocks, continue to be a source of pleasure and learning for young children at play. Wood blocks have the unique capacity to engage…

Phrenic palsy and analgesic quality of continuous supraclavicular vs. interscalene plexus blocks after shoulder surgery.

Science.gov (United States)

Wiesmann, T; Feldmann, C; Müller, H H; Nentwig, L; Beermann, A; El-Zayat, B F; Zoremba, M; Wulf, H; Steinfeldt, T

2016-09-01

Hemidiaphragmatic palsy is a common consequence of the interscalene brachial plexus block. It occurs less commonly with the supraclavicular approach. Register data suggest that the analgesic quality of a supraclavicular blockade is sufficient for arthroscopic shoulder surgery, although data on the post-operative analgesic effect are lacking. After approval by the ethics committee, patients having arthroscopic shoulder surgery under general anaesthesia were randomized to receive a continuous interscalene or supraclavicular blockade. Phrenic nerve function was evaluated through ultrasound examination of the diaphragm in combination with spirometry. Pain scores at rest and activity etc. were determined before catheter insertion, during observation in the post- anaesthesia care unit (PACU) and on post-operative day 1 (POD1). The initial application of 10 ml of ropivacaine 0.2% was followed by continuous application of 4 ml of ropivacaine 0.2%, plus a patient controlled analgesia (PCA) bolus of 4 ml/h. One hundred and twenty patients were randomized, of which 114 data sets were analysed. Complete hemidiaphragmatic paresis occurred in 43% of the interscalene group vs. 24% in the supraclavicular group during PACU stay. Rates of dyspnoea and hoarseness were similar. Horner's syndrome occurred in 21% of the interscalene but only 3% of the supraclavicular group on POD1. Pain scores were comparable for pain at rest and during stress at each time point. This trial showed a significantly greater incidence of phrenic nerve palsy of the interscalene group in PACU, but not on POD1. Post-operative analgesic quality was similar in both groups. Continuous supraclavicular blockade is a suitable alternative to the continuous interscalene technique. © 2016 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Multiple blocks of intermittent and continuous theta-burst stimulation applied via transcranial magnetic stimulation differently affect sensory responses in rat barrel cortex.

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Thimm, Andreas; Funke, Klaus

2015-02-15

Theta-burst stimulation (TBS) applied via transcranial magnetic stimulation is able to modulate human cortical excitability. Here we investigated in a rat model how two different forms of TBS, intermittent (iTBS) and continuous (cTBS), affect sensory responses in rat barrel cortex. We found that iTBS but less cTBS promoted late (>18 ms) sensory response components while not affecting the earliest response (8-18 ms). The effect increased with each of the five iTBS blocks applied. cTBS somewhat reduced the early response component after the first block but had a similar effect as iTBS after four to five blocks. We conclude that iTBS primarly modulates the activity of (inhibitory) cortical interneurons while cTBS may first reduce general neuronal excitability with a single block but reverse to iTBS-like effects with application of several blocks. Cortical sensory processing varies with cortical state and the balance of inhibition to excitation. Repetitive transcranial magnetic stimulation (rTMS) has been shown to modulate human cortical excitability. In a rat model, we recently showed that intermittent theta-burst stimulation (iTBS) applied to the corpus callosum, to activate primarily supragranular cortical pyramidal cells but fewer subcortical neurons, strongly reduced the cortical expression of parvalbumin (PV), indicating reduced activity of fast-spiking interneurons. Here, we used the well-studied rodent barrel cortex system to test how iTBS and continuous TBS (cTBS) modulate sensory responses evoked by either single or double stimuli applied to the principal (PW) and/or adjacent whisker (AW) in urethane-anaesthetized rats. Compared to sham stimulation, iTBS but not cTBS particularly enhanced late (>18 ms) response components of multi-unit spiking and local field potential responses in layer 4 but not the very early response (iTBS diminished the suppression of the second response evoked by paired PW or AW-PW stimulation at 20 ms intervals. The effects

Effect of continuous magnesium sulfate infusion on spinal block characteristics: A prospective study

Directory of Open Access Journals (Sweden)

Akansha Agrawal

2014-01-01

Full Text Available Background: Spinal anesthesia is an established mode of anesthesia for lower limb orthopedic surgeries. The limitations of the technique are short duration of action and limited post-operative analgesia. Concomitant use of intravenous infusion of magnesium sulfate may have an effect on the block characteristics and duration of action of intrathecal bupivacaine. Methods: A total of 80 American Society of Anesthesiologists I and II patients, either sex, 20-60 years of age scheduled for elective orthopedic fixation of fracture of long bones of lower limbs under spinal anesthesia were included. Spinal anesthesia administered with 2.5 ml heavy bupivacaine mixed with 10 mcg fentanyl. The groups were then divided to receive an infusion of injection magnesium sulfate 50 mg/kg/h over 15 min followed by 15 mg/kg/h until the end of the surgery (Group M and 15 ml of Normal Saline over 15 min followed by 100 ml/h until the end of surgery (Group S. Onset, duration of sensory and motor block and amount of post-operative analgesic were noted. Results: A total of 6 patients (Group M and seven patients (Group S had inadequate block and excluded from the study. Mean block height was T6. Time required to achieve block height was 8.82 min versus 7.42 min in Groups M and S respectively (P = 0.04. Mean duration of motor block was longer in group M (160.63 ± 17.76 min compared with Group S (130.12 ± 20.70 min (P = 0.000. Time for regression of sensory block to T12/L1was 206.88 ± 20.96 min (Group M and 163.88 ± 15.46 min (Group S (P = 0.000. Hemodynamic parameters were similar and statistically not significant. Need for first analgesic requirement was after 262.88 ± 21.11 min in group M and 193.25 ± 17.74 min in the group S (P = 0.000. Mean dosage of tramadol needed in first 24 h was less in group M (190 ± 30.38 mg vs. 265 ± 48.30 mg, P = 0.000. Conclusion: Use of intravenous magnesium with spinal anesthesia reduces post-operative pain and analgesic consumption.

Paroxysmal atrioventricular block: Electrophysiological mechanism of phase 4 conduction block in the His-Purkinje system: A comparison with phase 3 block.

Science.gov (United States)

Shenasa, Mohammad; Josephson, Mark E; Wit, Andrew L

2017-11-01

Paroxysmal atrioventricular (A-V) block is relatively rare, and due to its transient nature, it is often under recognized. It is often triggered by atrial, junctional, or ventricular premature beats, and occurs in the presence of a diseased His-Purkinje system (HPS). Here, we present a 45-year-old white male who was admitted for observation due to recurrent syncope and near-syncope, who had paroxysmal A-V block. The likely cellular electrophysiological mechanisms(s) of paroxysmal A-V block and its differential diagnosis and management are discussed. Continuous electrocardiographic monitoring was done while the patient was in the cardiac unit. Multiple episodes of paroxysmal A-V block were documented in this case. All episodes were initiated and terminated with atrial/junctional premature beats. The patient underwent permanent pacemaker implantation and has remained asymptomatic since then. Paroxysmal A-V block is rare and often causes syncope or near-syncope. Permanent pacemaker implantation is indicated according to the current guidelines. Paroxysmal A-V block occurs in the setting of diseased HPS and is bradycardia-dependent. The detailed electrophysiological mechanisms, which involve phase 4 diastolic depolarization, and differential diagnosis are discussed. © 2017 Wiley Periodicals, Inc.

The Safety and Efficacy of the Continuous Peripheral Nerve Block in Postoperative Analgesia of Pediatric Patients

Directory of Open Access Journals (Sweden)

Dušica Simić

2018-03-01

Full Text Available Postoperative analgesia is imperative in the youngest patients. Pain, especially if experienced during childhood, has numerous adverse effects—from psychological, through complications of the underlying disease (prolonged treatment, hospital stay, and increased costs of the treatment to an increase in the incidence of death due to the onset of the systemic inflammatory response. Peripheral blocks provide analgesia for 12–16 h, and are safer due to rare side effects that are easier to treat. The continuous peripheral block (CPNB has been increasingly used in recent years for complete and prolonged analgesia of pediatric patients, as well as a part of multidisciplinary treatment of complex regional pain syndrome. It has been shown that outpatient CPNB reduces the need for parenteral administration of opioid analgetics. It has also been proved that this technique can be used in pediatric patients in home conditions. Safety of CPNB is based on the increasing use of ultrasound as well as on the introduction of single enantiomers local anesthetics (ropivacaine and levobupivacaine in lower concentrations. It is possible to discharge patient home with catheter, but it is necessary to provide adequate education for staff, patients, and parents, as well as to have dedicated anesthesiology team. Postoperative period without major pain raises the morale of the child, parents. and medical staff.

On multiple blocking sets in Galois planes

NARCIS (Netherlands)

Blokhuis, A.; Lovász, L.; Storme, L.; Szönyi, T.

2007-01-01

This article continues the study of multiple blocking sets in PG(2, q). In [A. Blokhuis, L. Storme, T. Szonyi, Lacunary polynomials, multiple blocking sets and Baer subplanes. J. London Math. Soc. (2) 60 (1999), 321–332. MR1724814 (2000j:05025) Zbl 0940.51007], using lacunary polynomials, it was

21 CFR 177.1810 - Styrene block polymers.

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2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Styrene block polymers. 177.1810 Section 177.1810... FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1810 Styrene block polymers. The styrene...

[Dexmedetomidine combined with ropivacaine for continuous femoral nerve block improved postoperative sleep quality in elderly patients after total knee arthroplasty].

Science.gov (United States)

Wang, X L; Wang, J; Mu, D L; Wang, D X

2018-03-13

Objective: To investigate the effect of dexmedetomidine adding to ropivacaine for continuous femoral nerve block on the improvement of postoperative sleep quality in elderly patients after total knee arthroplasty. Methods: One hundred and sixty patients aged 60 years or older in Jishuitan Hospital scheduled for single total knee arthroplasty between Nov. 2016 and Jun. 2017 were recruited. All patients received spinal anesthesia and were randomized to receive either combined ropivacaine and dexmedetomidine (0.2% ropivacaine 250 ml and 5 μg/kg dexmedetomidine, at a rate of 5 ml/h or 0.1 μg·kg -1 ·h -1 dexmedetomidine, dexmedetomidine group) or only ropivacaine (0.2% ropivacaine, at a rate of 5 ml/h, controlled group) for continuous femoral nerve block as postoperative analgesia after surgery. The severity of postoperative pain was assessed with numeric rating scale at 4, 24, and 48 hours after surgery both at rest and with movement. Subjective sleep quality and delirium were evaluated daily during the first 3 days postoperatively. Results: The subjective sleep quality scores were 2(1-4), 2(1-4) and 4(2-8), 4(2-7) in dexmedetomidine group and controlled group respectively on the 1st and 2nd days after surgery. The scores of dexmedetomidine group were much better than those of controlled group ( Z =-4.597, -4.183, both P quality, postoperative analgesia, and reduce delirium in the elderly after total knee arthroplasty.

An efficient, block-by-block algorithm for inverting a block tridiagonal, nearly block Toeplitz matrix

International Nuclear Information System (INIS)

Reuter, Matthew G; Hill, Judith C

2012-01-01

We present an algorithm for computing any block of the inverse of a block tridiagonal, nearly block Toeplitz matrix (defined as a block tridiagonal matrix with a small number of deviations from the purely block Toeplitz structure). By exploiting both the block tridiagonal and the nearly block Toeplitz structures, this method scales independently of the total number of blocks in the matrix and linearly with the number of deviations. Numerical studies demonstrate this scaling and the advantages of our method over alternatives.

Child Care and Development Block Grant (CCDBG) Participation Continues to Fall

Science.gov (United States)

Matthews, Hannah; Schmit, Stephanie

2014-01-01

Child care subsidies help make quality child care affordable for low-income parents, allowing them to attend work or school to support their families while ensuring their children's healthy development. The Child Care and Development Block Grant (CCDBG) is the primary source of federal funding for child care subsidies for low-income working…

Clustering of GPS velocities in the Mojave Block, southeastern California

Science.gov (United States)

Savage, James C.; Simpson, Robert W.

2013-01-01

We find subdivisions within the Mojave Block using cluster analysis to identify groupings in the velocities observed at GPS stations there. The clusters are represented on a fault map by symbols located at the positions of the GPS stations, each symbol representing the cluster to which the velocity of that GPS station belongs. Fault systems that separate the clusters are readily identified on such a map. The most significant representation as judged by the gap test involves 4 clusters within the Mojave Block. The fault systems bounding the clusters from east to west are 1) the faults defining the eastern boundary of the Northeast Mojave Domain extended southward to connect to the Hector Mine rupture, 2) the Calico-Paradise fault system, 3) the Landers-Blackwater fault system, and 4) the Helendale-Lockhart fault system. This division of the Mojave Block is very similar to that proposed by Meade and Hager. However, no cluster boundary coincides with the Garlock Fault, the northern boundary of the Mojave Block. Rather, the clusters appear to continue without interruption from the Mojave Block north into the southern Walker Lane Belt, similar to the continuity across the Garlock Fault of the shear zone along the Blackwater-Little Lake fault system observed by Peltzer et al. Mapped traces of individual faults in the Mojave Block terminate within the block and do not continue across the Garlock Fault [Dokka and Travis, ].

76 FR 38533 - Alphabetical Listings: Specially Designated Nationals and Blocked Persons; Blocked Vessels...

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2011-06-30

.... * * * * * PART 546--DARFUR SANCTIONS REGULATIONS 0 22. The authority citation for part 546 continues to read as... Nationals and Blocked Persons List (``SDN List'') with the identifier ``[DARFUR].'' The SDN List is... Federal Register and incorporated into the SDN List with the identifier ``[BPI-DARFUR].'' * * * * * PART...

Single‑shot lamina technique of paravertebral block as an adjunct to ...

African Journals Online (AJOL)

2014-08-28

Aug 28, 2014 ... adjunct to GA for modified radical mastectomy with axillary dissection for breast cancer. The total ... treatment modality in many parts of the world, especially ... postoperative pain, reduced opioid consumption and.

Ion Transport in Nanostructured Block Copolymer/Ionic Liquid Membranes

OpenAIRE

Hoarfrost, Megan Lane

2012-01-01

Incorporating an ionic liquid into one block copolymer microphase provides a platform for combining the outstanding electrochemical properties of ionic liquids with a number of favorable attributes provided by block copolymers. In particular, block copolymers thermodynamically self-assemble into well-ordered nanostructures, which can be engineered to provide a durable mechanical scaffold and template the ionic liquid into continuous ion-conducting nanochannels. Understanding how the additio...

BlockLogo: Visualization of peptide and sequence motif conservation

DEFF Research Database (Denmark)

Olsen, Lars Rønn; Kudahl, Ulrich Johan; Simon, Christian

2013-01-01

BlockLogo is a web-server application for the visualization of protein and nucleotide fragments, continuous protein sequence motifs, and discontinuous sequence motifs using calculation of block entropy from multiple sequence alignments. The user input consists of a multiple sequence alignment, se...

Enzymatic Continuous Flow Synthesis of Thiol-Terminated Poly(δ-Valerolactone) and Block Copolymers.

Science.gov (United States)

Zhu, Ning; Huang, Weijun; Hu, Xin; Liu, Yihuan; Fang, Zheng; Guo, Kai

2018-04-01

Thiol-terminated poly(δ-valerolactone) is directly synthesized via enzymatic 6-mercapto-1-hexanol initiated ring-opening polymerization in both batch and microreactor. By using Candida antartica Lipase B immobilized tubular reactor, narrowly dispersed poly(δ-valerolactone) with higher thiol fidelity is more efficiently prepared in contrast to the batch reactor. Moreover, the integrated enzyme packed tubular reactor system is established to perform the chain extension experiments. Thiol-terminated poly(δ-valerolactone)-block-poly(ε-caprolactone) and poly(ε-caprolactone)-block-poly(δ-valerolactone) are easily prepared by modulating the monomer introduction sequence. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cellient™ automated cell block versus traditional cell block preparation: a comparison of morphologic features and immunohistochemical staining.

Science.gov (United States)

Wagner, David G; Russell, Donna K; Benson, Jenna M; Schneider, Ashley E; Hoda, Rana S; Bonfiglio, Thomas A

2011-10-01

Traditional cell block (TCB) sections serve as an important diagnostic adjunct to cytologic smears but are also used today as a reliable preparation for immunohistochemical (IHC) studies. There are many ways to prepare a cell block and the methods continue to be revised. In this study, we compare the TCB with the Cellient™ automated cell block system. Thirty-five cell blocks were obtained from 16 benign and 19 malignant nongynecologic cytology specimens at a large university teaching hospital and prepared according to TCB and Cellient protocols. Cell block sections from both methods were compared for possible differences in various morphologic features and immunohistochemical staining patterns. In the 16 benign cases, no significant morphologic differences were found between the TCB and Cellient cell block sections. For the 19 malignant cases, some noticeable differences in the nuclear chromatin and cellularity were identified, although statistical significance was not attained. Immunohistochemical or special stains were performed on 89% of the malignant cases (17/19). Inadequate cellularity precluded full evaluation in 23% of Cellient cell block IHC preparations (4/17). Of the malignant cases with adequate cellularity (13/17), the immunohistochemical staining patterns from the different methods were identical in 53% of cases. The traditional and Cellient cell block sections showed similar morphologic and immunohistochemical staining patterns. The only significant difference between the two methods concerned the lower overall cell block cellularity identified during immunohistochemical staining in the Cellient cell block sections. Copyright © 2010 Wiley-Liss, Inc.

47 CFR 24.711 - Installment payments for licenses for frequency Block C.

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2010-10-01

... Block C. 24.711 Section 24.711 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON....711 Installment payments for licenses for frequency Block C. Installment payments. Each eligible licensee of frequency Block C may pay the remaining 90 percent of the net auction price for the license in...

47 CFR 24.716 - Installment payments for licenses for frequency Block F.

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2010-10-01

... Block F. 24.716 Section 24.716 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON....716 Installment payments for licenses for frequency Block F. Installment Payments. Each eligible licensee of frequency Block F may pay the remaining 80 percent of the net auction price for the license in...

Analgesic efficacy of continuous femoral nerve block commenced prior to operative fixation of fractured neck of femur

LENUS (Irish Health Repository)

Szucs, Szilard

2012-06-27

AbstractBackgroundPeripheral nerve blocks are effective in treating acute pain, thereby minimizing the requirement for opiate analgesics. Fractured neck of femur (FNF) is a common, painful injury. The provision of effective analgesia to this cohort is challenging but an important determinant of their functional outcome. We investigated the analgesic efficacy of continuous femoral nerve block (CFNB) in patients with FNF.MethodsFollowing institutional ethical approval and with informed consent, patients awaiting FNF surgery were randomly allocated to receive either standard opiate-based analgesia (Group 1) or a femoral perineural catheter (Group 2). Patients in Group 1 received parenteral morphine as required. Those in Group 2 received a CFNB comprising a bolus of local anaesthetic followed by a continuous infusion of 0.25% bupivacaine. For both Groups, rescue analgesia consisted of intramuscular morphine as required and all patients received paracetamol regularly. Pain was assessed using a visual analogue scale at rest and during passive movement (dynamic pain score) at 30 min following first analgesic intervention and six hourly thereafter for 72 hours. Patient satisfaction with the analgesic regimen received was recorded using verbal rating scores (0-10). The primary outcome measured was dynamic pain score from initial analgesic intervention to 72 hours later.ResultsOf 27 recruited, 24 patients successfully completed the study protocol and underwent per protocol analysis. The intervals from recruitment to the study until surgery were similar in both groups [31.4(17.7) vs 27.5(14.2) h, P = 0.57]. The groups were similar in terms of baseline clinical characteristics. For patients in Group 2, pain scores at rest were less than those reported by patients in Group 1 [9.5(9.4) vs 31(28), P = 0.031]. Dynamic pain scores reported by patients in Group 2 were less at each time point from 30 min up to 54 hours [e.g at 6 h 30.7(23.4) vs 67.0(32.0), P = 0

47 CFR 24.712 - Bidding credits for licenses won for frequency Block C.

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2010-10-01

... Block C. 24.712 Section 24.712 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON....712 Bidding credits for licenses won for frequency Block C. (a) Except with respect to licenses won in... acquired in either the auction for frequency block C that began on December 18, 1995, or the reauction of...

Complete heart block due to diphtheritic myocarditis in the present era

Directory of Open Access Journals (Sweden)

Mithun J Varghese

2013-01-01

Full Text Available Diphtheria continues to be reported from many parts of the world. Complete heart block is rare but often fatal complication of diphtheric myocarditis. We report six children with diphtheric myocarditis who presented with complete heart block. Three patients survived, one with persistent complete heart block. Aggressive supportive management including transvenous pacing may result in complete recovery in a significant number of children with diphtheric myocarditis.

Bilateral transversus abdominis plane (TAP) block with 24 hours ropivacaine infusion via TAP catheters

DEFF Research Database (Denmark)

Petersen, Pernille L; Hilsted, Karen L; Dahl, Jørgen B

2013-01-01

The analgesic effect of a TAP block has been investigated in various surgical settings. There are however limited information about block level and block duration. Furthermore, there is a lack of information about continuous TAP block after ultrasound-guided posterior TAP blocks.The aim of this d...... of this double-blind randomized study was therefore to investigate the effect of an ultrasound-guided posterior TAP block with 24 hours local anesthetic infusion via a TAP catheter....

Analysis of Block OMP using Block RIP

OpenAIRE

Wang, Jun; Li, Gang; Zhang, Hao; Wang, Xiqin

2011-01-01

Orthogonal matching pursuit (OMP) is a canonical greedy algorithm for sparse signal reconstruction. When the signal of interest is block sparse, i.e., it has nonzero coefficients occurring in clusters, the block version of OMP algorithm (i.e., Block OMP) outperforms the conventional OMP. In this paper, we demonstrate that a new notion of block restricted isometry property (Block RIP), which is less stringent than standard restricted isometry property (RIP), can be used for a very straightforw...

Building blocks of Collagen based biomaterial devices

Indian Academy of Sciences (India)

First page Back Continue Last page Overview Graphics. Building blocks of Collagen based biomaterial devices. Collagen as a protein. Collagen in tissues and organs. Stabilizing and cross linking agents. Immunogenicity. Hosts (drugs). Controlled release mechanisms of hosts. Biodegradability, workability into devices ...

Hoarseness of voice after supraclavicular ultrasound-guided subclavian perivascular brachial plexus block

Directory of Open Access Journals (Sweden)

Monika Gupta

2017-01-01

Full Text Available Supraclavicular brachial plexus nerve block is ideal for surgical procedures at or distal to the elbow. Ultrasound (USG continues to grow in popularity as a method of nerve localization, and for the supraclavicular block, it has the advantage of allowing real-time visualization of the plexus, pleura, and vessels along with the needle and local anesthetic spread, but it may conversely create a false sense of security. The incidence of the recurrent laryngeal nerve (RLN block occurring with supraclavicular approach is 1.3% of patients.[10] Incidence of RLN block with USG-guided supraclavicular block is not known. In this case report, we discuss a rare complication of RLN block which occurred while performing a supraclavicular perivascular block performed under USG guidance.

Microtome Sliced Block Copolymers and Nanoporous Polymers as Masks for Nanolithography

DEFF Research Database (Denmark)

Shvets, Violetta; Schulte, Lars; Ndoni, Sokol

2014-01-01

Introduction. Block copolymers self-assembling properties are commonly used for creation of very fine nanostructures [1]. Goal of our project is to test new methods of the block-copolymer lithography mask preparation: macroscopic pieces of block-copolymers or nanoporous polymers with cross...... PDMS can be chemically etched from the PB matrix by tetrabutylammonium fluoride in tetrahydrofuran and macroscopic nanoporous PB piece is obtained. Both block-copolymer piece and nanoporous polymer piece were sliced with cryomicrotome perpendicular to the axis of cylinder alignment and flakes...... of etching patterns appear only under the certain parts of thick flakes and are not continuous. Although flakes from block copolymer are thinner and more uniform in thickness than flakes from nanoporous polymer, quality of patterns under nanoporous flakes appeared to be better than under block copolymer...

Nerve Blocks

Science.gov (United States)

... News Physician Resources Professions Site Index A-Z Nerve Blocks A nerve block is an injection to ... the limitations of Nerve Block? What is a Nerve Block? A nerve block is an anesthetic and/ ...

47 CFR 24.717 - Bidding credits for licenses for frequency Block F.

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2010-10-01

... 47 Telecommunication 2 2010-10-01 2010-10-01 false Bidding credits for licenses for frequency Block F. 24.717 Section 24.717 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON....717 Bidding credits for licenses for frequency Block F. (a) Except with respect to licenses won in...

Business continuity 2014: From traditional to integrated Business Continuity Management.

Science.gov (United States)

Ee, Henry

As global change continues to generate new challenges and potential threats to businesses, traditional business continuity management (BCM) slowly reveals its limitations and weak points to ensuring 'business resiliency' today. Consequently, BCM professionals also face the challenge of re-evaluating traditional concepts and introducing new strategies and industry best practices. This paper points to why traditional BCM is no longer sufficient in terms of enabling businesses to survive in today's high-risk environment. It also looks into some of the misconceptions about BCM and other stumbling blocks to establishing effective BCM today. Most importantly, however, this paper provides tips based on the Business Continuity Institute's (BCI) Good Practices Guideline (GPG) and the latest international BCM standard ISO 22301 on how to overcome the issues and challenges presented.

Comparison of continuous interscalene block and subacromial infusion of local anesthetic for postoperative analgesia after open shoulder surgery.

Science.gov (United States)

Baskan, Semih; Cankaya, Deniz; Unal, Hidayet; Yoldas, Burak; Taspinar, Vildan; Deveci, Alper; Tabak, Yalcin; Baydar, Mustafa

2017-01-01

This study compared the efficacy of continuous interscalene block (CISB) and subacromial infusion of local anesthetic (CSIA) for postoperative analgesia after open shoulder surgery. This randomized, prospective, double-blinded, single-center study included 40 adult patients undergoing open shoulder surgery. All patients received a standardized general anesthetic. The patients were separated into group CISB and group CSIA. A loading dose of 40 mL 0.25% bupivacaine was administered and patient-controlled analgesia was applied by catheter with 0.1% bupivacaine 5 mL/h throughout 24 h basal infusion, 2 mL bolus dose, and 20 min knocked time in both groups postoperatively. Visual analog scale (VAS) scores, additional analgesia need, local anesthetic consumption, complications, and side effects were recorded during the first 24 h postoperatively. The range of motion (ROM) score was recorded preoperatively and in the first and third weeks postoperatively. A statistically significant difference was determined between the groups in respect of consumption of local anesthetic, VAS scores, additional analgesia consumption, complications, and side effects, with lower values recorded in the CISB group. There were no significant differences in ROM scoring in the preoperative and postoperative third week between the two groups but there were significant differences in ROM scoring in the postoperative first week, with higher ROM scoring values in the group CISB patients. The results of this study have shown that continuous interscalene infusion of bupivacaine is an effective and safe method of postoperative analgesia after open shoulder surgery.

Testing block subdivision algorithms on block designs

Science.gov (United States)

Wiseman, Natalie; Patterson, Zachary

2016-01-01

Integrated land use-transportation models predict future transportation demand taking into account how households and firms arrange themselves partly as a function of the transportation system. Recent integrated models require parcels as inputs and produce household and employment predictions at the parcel scale. Block subdivision algorithms automatically generate parcel patterns within blocks. Evaluating block subdivision algorithms is done by way of generating parcels and comparing them to those in a parcel database. Three block subdivision algorithms are evaluated on how closely they reproduce parcels of different block types found in a parcel database from Montreal, Canada. While the authors who developed each of the algorithms have evaluated them, they have used their own metrics and block types to evaluate their own algorithms. This makes it difficult to compare their strengths and weaknesses. The contribution of this paper is in resolving this difficulty with the aim of finding a better algorithm suited to subdividing each block type. The proposed hypothesis is that given the different approaches that block subdivision algorithms take, it's likely that different algorithms are better adapted to subdividing different block types. To test this, a standardized block type classification is used that consists of mutually exclusive and comprehensive categories. A statistical method is used for finding a better algorithm and the probability it will perform well for a given block type. Results suggest the oriented bounding box algorithm performs better for warped non-uniform sites, as well as gridiron and fragmented uniform sites. It also produces more similar parcel areas and widths. The Generalized Parcel Divider 1 algorithm performs better for gridiron non-uniform sites. The Straight Skeleton algorithm performs better for loop and lollipop networks as well as fragmented non-uniform and warped uniform sites. It also produces more similar parcel shapes and patterns.

47 CFR 52.20 - Thousands-block number pooling.

Science.gov (United States)

2010-10-01

... aligned with any particular telecommunication industry segment, and shall comply with the same neutrality... 47 Telecommunication 3 2010-10-01 2010-10-01 false Thousands-block number pooling. 52.20 Section 52.20 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES...

Combination of Transversus abdominis plane block and Serratus plane block anesthesia in dogs submitted to masctetomy

Directory of Open Access Journals (Sweden)

Luciana G. Teixeira

Full Text Available ABSTRACT: This paper pretends to demonstrate the effect of the combination of transversus abdominis plane block (TAP block and Serratus plane block (SP block techniques in analgesia of 4 dogs undergoing total unilateral mastectomy. Dogs were premedicated with methadone (0.5mg.kg-1 intramuscularly. Anesthesia was induced with propofol (6mg.kg-1 and midazolam (0.3mg.kg-1 and maintained with isoflurane. SP and TAP block were performed unilaterally using ultrasound by the injection of bupivacaine 0.25% (0.3mL kg-1 diluted with NaCl solution 1:1. Heart rate (HR, respiratory rate (f, non-invasive arterial pressure, esophageal temperature (T, oxygen saturation (SpO2 and electrocardiogram were monitored continuously. Animals were monitored for two and four hours after extubation for pain by using the Canine Acute Pain Scale from Colorado State University. Two hours after extubation, tramadol (4mg.kg-1 and dipyrone (25mg.kg-1 was administered to all dogs. It was not observed any alteration on cardiac rhythm. HR, f, T and mean arterial pressure remained below the preincisional values for all dogs. No dog required intraoperative rescue analgesia. Recovery from anesthesia was without any complication. All animals scored 0 (0/5 at pain scale, two and four hours after extubation and none of them expressed concern over the surgical wound. Dogs were able to walk before two hours after extubation. The combination of both techniques is effective in anesthetic blocking the thoracic and abdominal walls and it is suggested both may be included in the multimodal analgesia protocols for this type of surgery.

Cutaneous Sensory Block Area, Muscle-Relaxing Effect, and Block Duration of the Transversus Abdominis Plane Block

DEFF Research Database (Denmark)

Støving, Kion; Rothe, Christian; Rosenstock, Charlotte V

2015-01-01

BACKGROUND AND OBJECTIVES: The transversus abdominis plane (TAP) block is a widely used nerve block. However, basic block characteristics are poorly described. The purpose of this study was to assess the cutaneous sensory block area, muscle-relaxing effect, and block duration. METHODS: Sixteen...... healthy volunteers were randomized to receive an ultrasound-guided unilateral TAP block with 20 mL 7.5 mg/mL ropivacaine and placebo on the contralateral side. Measurements were performed at baseline and 90 minutes after performing the block. Cutaneous sensory block area was mapped and separated...... into a medial and lateral part by a vertical line through the anterior superior iliac spine. We measured muscle thickness of the 3 lateral abdominal muscle layers with ultrasound in the relaxed state and during maximal voluntary muscle contraction. The volunteers reported the duration of the sensory block...

Optimizing block-based maintenance under random machine usage

NARCIS (Netherlands)

de Jonge, Bram; Jakobsons, Edgars

Existing studies on maintenance optimization generally assume that machines are either used continuously, or that times until failure do not depend on the actual usage. In practice, however, these assumptions are often not realistic. In this paper, we consider block-based maintenance optimization

Reactivity effect of poisoned beryllium block shuffling in the MARIA reactor

International Nuclear Information System (INIS)

Andrzejewski, K.; Kulikowska, T.

2000-01-01

The paper is a continuation of the analysis of beryllium blocks poisoning by Li-6 and He-3 in the MARIA reactor, presented at the 22 RERTR Meeting in Budapest. A new computational tool, the REBUS-3 code, has been used for predicting the amount of poison. The code has been put into operation on a HP computer and the beryllium transmutation chains have been activated with assistance of the ANL RERTR staff. The horizontal and vertical poison distribution within beryllium blocks has been studied. A simple shuffling of beryllium blocks has been simulated to check the effect of exchanging a block with high poison concentration, adjacent to fuel elements, with a peripheral one with a low poison concentration

["Habitual" left branch block alternating with 2 "disguised" bracnch block].

Science.gov (United States)

Lévy, S; Jullien, G; Mathieu, P; Mostefa, S; Gérard, R

1976-10-01

Two cases of alternating left bundle branch block and "masquerading block" (with left bundle branch morphology in the stnadard leads and right bundle branch block morphology in the precordial leads) were studied by serial tracings and his bundle electrocardiography. In case 1 "the masquerading" block was associated with a first degree AV block related to a prolongation of HV interval. This case is to our knowledge the first cas of alternating bundle branch block in which his bundle activity was recorded in man. In case 2, the patient had atrial fibrilation and His bundle recordings were performed while differents degrees of left bundle branch block were present: The mechanism of the alternation and the concept of "masquerading" block are discussed. It is suggested that this type of block represents a right bundle branch block associated with severe lesions of the "left system".

E-Block: A Tangible Programming Tool with Graphical Blocks

Directory of Open Access Journals (Sweden)

Danli Wang

2013-01-01

Full Text Available This paper designs a tangible programming tool, E-Block, for children aged 5 to 9 to experience the preliminary understanding of programming by building blocks. With embedded artificial intelligence, the tool defines the programming blocks with the sensors as the input and enables children to write programs to complete the tasks in the computer. The symbol on the programming block's surface is used to help children understanding the function of each block. The sequence information is transferred to computer by microcomputers and then translated into semantic information. The system applies wireless and infrared technologies and provides user with feedbacks on both screen and programming blocks. Preliminary user studies using observation and user interview methods are shown for E-Block's prototype. The test results prove that E-Block is attractive to children and easy to learn and use. The project also highlights potential advantages of using single chip microcomputer (SCM technology to develop tangible programming tools for children.

E-Block: A Tangible Programming Tool with Graphical Blocks

OpenAIRE

Danli Wang; Yang Zhang; Shengyong Chen

2013-01-01

This paper designs a tangible programming tool, E-Block, for children aged 5 to 9 to experience the preliminary understanding of programming by building blocks. With embedded artificial intelligence, the tool defines the programming blocks with the sensors as the input and enables children to write programs to complete the tasks in the computer. The symbol on the programming block's surface is used to help children understanding the function of each block. The sequence information is transfer...

Strategies for Teaching in a Block-of-Time Schedule.

Science.gov (United States)

Hackmann, Donald G.; Schmitt, Donna M.

1997-01-01

Offers suggestions for developing creative instructional approaches in time-blocked classes. Teachers should continuously engage students in active learning, include group activities to encourage student participation, incorporate activities addressing multiple intelligences, use creative thinking activities, move outside the classroom, employ…

A standard graphite block

Energy Technology Data Exchange (ETDEWEB)

Ivkovic, M; Zdravkovic, Z; Sotic, O [Department of Reactor Physics and Dynamics, Boris Kidric Institute of nuclear sciences Vinca, Belgrade (Yugoslavia)

1966-04-15

A graphite block was calibrated for the thermal neutron flux of the Ra-Be source using indium foils as detectors. Experimental values of the thermal neutron flux along the central vertical axis of the system were corrected for the self-shielding effect and depression of flux in the detector. The experimental values obtained were compared with the values calculated on the basis of solving the conservation neutron equation by the continuous slowing-down theory. In this theoretical calculation of the flux the Ra-Be source was divided into three resonance energy regions. The measurement of the thermal neutron diffusion length in the standard graphite block is described. The measurements were performed in the thermal neutron region of the system. The experimental results were interpreted by the diffusion theory for point thermal neutron source in the finite system. The thermal neutron diffusion length was calculated to be L= 50.9 {+-}3.1 cm for the following graphite characteristics: density = 1.7 g/cm{sup 3}; boron content = 0.1 ppm; absorption cross section = 3.7 mb.

A standard graphite block

International Nuclear Information System (INIS)

Ivkovic, M.; Zdravkovic, Z.; Sotic, O.

1966-04-01

A graphite block was calibrated for the thermal neutron flux of the Ra-Be source using indium foils as detectors. Experimental values of the thermal neutron flux along the central vertical axis of the system were corrected for the self-shielding effect and depression of flux in the detector. The experimental values obtained were compared with the values calculated on the basis of solving the conservation neutron equation by the continuous slowing-down theory. In this theoretical calculation of the flux the Ra-Be source was divided into three resonance energy regions. The measurement of the thermal neutron diffusion length in the standard graphite block is described. The measurements were performed in the thermal neutron region of the system. The experimental results were interpreted by the diffusion theory for point thermal neutron source in the finite system. The thermal neutron diffusion length was calculated to be L= 50.9 ±3.1 cm for the following graphite characteristics: density = 1.7 g/cm 3 ; boron content = 0.1 ppm; absorption cross section = 3.7 mb

Poly(ferrocenylsilane)-block-Polylactide Block Copolymers

NARCIS (Netherlands)

Roerdink, M.; van Zanten, Thomas S.; Hempenius, Mark A.; Zhong, Zhiyuan; Feijen, Jan; Vancso, Gyula J.

2007-01-01

A PFS/PLA block copolymer was studied to probe the effect of strong surface interactions on pattern formation in PFS block copolymer thin films. Successful synthesis of PFS-b-PLA was demonstrated. Thin films of these polymers show phase separation to form PFS microdomains in a PLA matrix, and

Anesthetic considerations in the patients of chronic obstructive pulmonary disease undergoing laparoscopic surgeries.

Science.gov (United States)

Khetarpal, Ranjana; Bali, Kusum; Chatrath, Veena; Bansal, Divya

2016-01-01

The aim of this study was to review the various anesthetic options which can be considered for laparoscopic surgeries in the patients with the chronic obstructive pulmonary disease. The literature search was performed in the Google, PubMed, and Medscape using key words "analgesia, anesthesia, general, laparoscopy, lung diseases, obstructive." More than thirty-five free full articles and books published from the year 1994 to 2014 were retrieved and studied. Retrospective data observed from various studies and case reports showed regional anesthesia (RA) to be valid and safer option in the patients who are not good candidates of general anesthesia like patients having obstructive pulmonary diseases. It showed better postoperative patient outcome with respect to safety, efficacy, postoperative pulmonary complications, and analgesia. So depending upon disease severity RA in various forms such as spinal anesthesia, paravertebral block, continuous epidural anesthesia, combined spinal epidural anesthesia (CSEA), and CSEA with bi-level positive airway pressure should be considered.

Access block in NSW hospitals, 1999-2001: does the definition matter?

Science.gov (United States)

Forero, Roberto; Mohsin, Mohammed; Bauman, Adrian E; Ieraci, Sue; Young, Lis; Phung, Hai N; Hillman, Kenneth M; McCarthy, Sally M; Hugelmeyer, C David

2004-01-19

To estimate the magnitude of access block and its trend over time in New South Wales hospitals, using different definitions of access block, and to explore its association with clinical and non-clinical factors. An epidemiological study using the Emergency Department Information System datasets (1 January 1999 to 31 December 2001) from a sample of 55 NSW hospitals. Prevalence of access block measured by four different definitions; strength of association between access block, type of hospital, year of presentation, mode and time of arrival, triage category (an indicator of urgency), age and sex. Rates of access block (for all four definitions) increased between 1999 and 2001 by 1%-2% per year. There were increases across all regions of NSW, but urban regions in particular. Patients presenting to Principal Referral hospitals and those who arrived at night were more likely to experience access block. After adjusting for triage category and year of presentation, the mode of arrival, time of arrival, type of hospital, age and sex were significantly associated with access block. Access block continues to increase across NSW, whatever the definition used. We recommend that hospitals in NSW and Australia move to the use of one standard definition of access block, as our study suggests there is no significant additional information emerging from the use of multiple definitions.

Temporary persistence of conduction block after prolonged kilohertz frequency alternating current on rat sciatic nerve

Science.gov (United States)

Bhadra, Narendra; Foldes, Emily; Vrabec, Tina; Kilgore, Kevin; Bhadra, Niloy

2018-02-01

Objective. Application of kilohertz frequency alternating current (KHFAC) waveforms can result in nerve conduction block that is induced in less than a second. Conduction recovers within seconds when KHFAC is applied for about 5-10 min. This study investigated the effect of repeated and prolonged application of KHFAC on rat sciatic nerve with bipolar platinum electrodes. Approach. Varying durations of KHFAC at signal amplitudes for conduction block with intervals of no stimulus were studied. Nerve conduction was monitored by recording peak Gastrocnemius muscle force utilizing stimulation electrodes proximal (PS) and distal (DS) to a blocking electrode. The PS signal traveled through the block zone on the nerve, while the DS went directly to the motor end-plate junction. The PS/DS force ratio provided a measure of conduction patency of the nerve in the block zone. Main results. Conduction recovery times were found to be significantly affected by the cumulative duration of KHFAC application. Peak stimulated muscle force returned to pre-block levels immediately after cessation of KHFAC delivery when it was applied for less than about 15 min. They fell significantly but recovered to near pre-block levels for cumulative stimulus of 50  ±  20 min, for the tested On/Off times and frequencies. Conduction recovered in two phases, an initial fast one (60-80% recovery), followed by a slower phase. No permanent conduction block was seen at the end of the observation period during any experiment. Significance. This carry-over block effect may be exploited to provide continuous conduction block in peripheral nerves without continuous application of KHFAC.

Block and sub-block boundary strengthening in lath martensite

NARCIS (Netherlands)

Du, C.; Hoefnagels, J.P.M.; Vaes, R.; Geers, M.G.D.

2016-01-01

Well-defined uniaxial micro-tensile tests were performed on lath martensite single block specimens and multi-block specimens with different number of block boundaries parallel to the loading direction. Detailed slip trace analyses consistently revealed that in the {110}<111> slip system with the

On the Eigenvalues and Eigenvectors of Block Triangular Preconditioned Block Matrices

KAUST Repository

Pestana, Jennifer

2014-01-01

Block lower triangular matrices and block upper triangular matrices are popular preconditioners for 2×2 block matrices. In this note we show that a block lower triangular preconditioner gives the same spectrum as a block upper triangular preconditioner and that the eigenvectors of the two preconditioned matrices are related. © 2014 Society for Industrial and Applied Mathematics.

Powder wastes confinement block and manufacturing process of this block

International Nuclear Information System (INIS)

Dagot, L.; Brunel, G.

1996-01-01

This invention concerns a powder wastes containment block and a manufacturing process of this block. In this block, the waste powder is encapsulated in a thermo hardening polymer as for example an epoxy resin, the encapsulated resin being spread into cement. This block can contain between 45 and 55% in mass of wastes, between 18 and 36% in mass of polymer and between 14 and 32% in mass of cement. Such a containment block can be used for the radioactive wastes storage. (O.M.). 4 refs

Blocked Randomization with Randomly Selected Block Sizes

Directory of Open Access Journals (Sweden)

Jimmy Efird

2010-12-01

Full Text Available When planning a randomized clinical trial, careful consideration must be given to how participants are selected for various arms of a study. Selection and accidental bias may occur when participants are not assigned to study groups with equal probability. A simple random allocation scheme is a process by which each participant has equal likelihood of being assigned to treatment versus referent groups. However, by chance an unequal number of individuals may be assigned to each arm of the study and thus decrease the power to detect statistically significant differences between groups. Block randomization is a commonly used technique in clinical trial design to reduce bias and achieve balance in the allocation of participants to treatment arms, especially when the sample size is small. This method increases the probability that each arm will contain an equal number of individuals by sequencing participant assignments by block. Yet still, the allocation process may be predictable, for example, when the investigator is not blind and the block size is fixed. This paper provides an overview of blocked randomization and illustrates how to avoid selection bias by using random block sizes.

Population Blocks.

Science.gov (United States)

Smith, Martin H.

1992-01-01

Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

Identification of fractional-order systems with time delays using block pulse functions

Science.gov (United States)

Tang, Yinggan; Li, Ning; Liu, Minmin; Lu, Yao; Wang, Weiwei

2017-07-01

In this paper, a novel method based on block pulse functions is proposed to identify continuous-time fractional-order systems with time delays. First, the operational matrices of block pulse functions for fractional integral operator and time delay operator are derived. Then, these operational matrices are applied to convert the continuous-time fractional-order systems with time delays to an algebraic equation. Finally, the system's parameters along with the differentiation orders and the time delays are all simultaneously estimated through minimizing a quadric error function. The proposed method reduces the computation complexity of the identification process, and also it does not require the system's differentiation orders to be commensurate. The effectiveness of the proposed method are demonstrated by several numerical examples.

Pectoral nerves (PECS) and intercostal nerve block for cardiac resynchronization therapy device implantation.

Science.gov (United States)

Fujiwara, Atsushi; Komasawa, Nobuyasu; Minami, Toshiaki

2014-01-01

A 71-year-old man was scheduled to undergo cardiac resynchronization therapy device (CRTD) implantation. He was combined with severe chronic heart failure due to ischemic heart disease. NYHA class was 3 to 4 and electrocardiogram showed non-sustained ventricular. Ejection fraction was about 20% revealed by transthoracic echocardiogram. He was also on several anticoagulation medications. We planned to implant the device under the greater pectoral muscle. As general anesthesia was considered risky, monitored anesthesia care utilizing peripheral nerve block and slight sedation was scheduled. Pectoral nerves (PECS) block and intercostal block was performed under ultrasonography with ropivacaine. For sedation during the procedure, continuous infusion of dexmedetomidine without a loading dose was performed. The procedure lasted about 3 hours, but the patient showed no pain or restlessness. Combination of PECS block and intercostal block may provide effective analgesia for CRTD implantation.

Development of experimental approach to examine U occurrence continuity over the extended area reconnoitory boreholes: Lostoin Block, West Khasi Hills district, Meghalaya (India).

Science.gov (United States)

Kukreti, B M; Kumar, Pramod; Sharma, G K

2015-10-01

Exploratory drilling was undertaken in the Lostoin block, West Khasi Hills district of Meghalaya based on the geological extension to the major uranium deposit in the basin. Gamma ray logging of drilled boreholes shows considerable subsurface mineralization in the block. However, environmental and exploration related challenges such as climatic, logistic, limited core drilling and poor core recovery etc. in the block severely restricted the study of uranium exploration related index parameters for the block with a high degree confidence. The present study examines these exploration related challenges and develops an integrated approach using representative sampling of reconnoitory boreholes in the block. Experimental findings validate a similar geochemically coherent nature of radio elements (K, Ra and Th) in the Lostoin block uranium hosting environment with respect to the known block of Mahadek basin and uranium enrichment is confirmed by the lower U to Th correlation index (0.268) of hosting environment. A mineralized zone investigation in the block shows parent (refers to the actual parent uranium concentration at a location and not a secondary concentration such as the daughter elements which produce the signal from a total gamma ray measurement) favoring uranium mineralization. The confidence parameters generated under the present study have implications for the assessment of the inferred category of uranium ore in the block and setting up a road map for the systematic exploration of large uranium potential occurring over extended areas in the basin amid prevailing environmental and exploratory impediments. Copyright © 2015 Elsevier Ltd. All rights reserved.

Theoretical and computational studies of entangled rod-coil block copolymer diffusion

Science.gov (United States)

Wang, Muzhou; Alexander-Katz, Alfredo; Olsen, B. D.

2012-02-01

Despite continued interest in the thermodynamics of rod-coil block copolymers for functional nanostructured materials in organic electronics and biomaterials, relatively few studies have investigated the dynamics of these systems which are important for understanding diffusion, mechanics, and self-assembly kinetics. Here, the diffusion of coil-rod-coil block copolymers through entangled melts is simulated using the Kremer-Grest molecular dynamics model, demonstrating that the mismatch between the curvature of the rod and coil blocks results in dramatically slower reptation through the entanglement tube. For rod lengths near the tube diameter, this hindered diffusion is explained by a local curvature-dependent free energy penalty produced by the curvature mismatch, resulting in a rough energy surface as the rod moves along the tube contour. Compared to coil homopolymers which reptate freely along the tube, rod-coil block copolymers undergo an activated diffusion process which is considerably slower as the rod length increases. For large rods, diffusion of the rod through the tube only occurs when the coil blocks occupy straight entanglement tubes, which requires ``arm retraction'' as the dominant relaxation mechanism.

Minimum description length block finder, a method to identify haplotype blocks and to compare the strength of block boundaries.

Science.gov (United States)

Mannila, H; Koivisto, M; Perola, M; Varilo, T; Hennah, W; Ekelund, J; Lukk, M; Peltonen, L; Ukkonen, E

2003-07-01

We describe a new probabilistic method for finding haplotype blocks that is based on the use of the minimum description length (MDL) principle. We give a rigorous definition of the quality of a segmentation of a genomic region into blocks and describe a dynamic programming algorithm for finding the optimal segmentation with respect to this measure. We also describe a method for finding the probability of a block boundary for each pair of adjacent markers: this gives a tool for evaluating the significance of each block boundary. We have applied the method to the published data of Daly and colleagues. The results expose some problems that exist in the current methods for the evaluation of the significance of predicted block boundaries. Our method, MDL block finder, can be used to compare block borders in different sample sets, and we demonstrate this by applying the MDL-based method to define the block structure in chromosomes from population isolates.

Oligomers and Polymers Based on Pentacene Building Blocks

Science.gov (United States)

Lehnherr, Dan; Tykwinski, Rik R.

2010-01-01

Functionalized pentacene derivatives continue to provide unique materials for organic semiconductor applications. Although oligomers and polymers based on pentacene building blocks remain quite rare, recent synthetic achievements have provided a number of examples with varied structural motifs. This review highlights recent work in this area and, when possible, contrasts the properties of defined-length pentacene oligomers to those of mono- and polymeric systems.

A modified Delphi survey on the signs and symptoms of low back pain: indicators for an interventional management approach.

Science.gov (United States)

Cid, José; De La Calle, José L; López, Esther; Del Pozo, Cristina; Perucho, Alfredo; Acedo, María Soledad; Bedmar, Dolores; Benito, Javier; De Andrés, Javier; Díaz, Susana; García, Juan Antonio; Gómez-Caro, Leticia; Gracia, Adolfo; Hernández, José María; Insausti, Joaquín; Madariaga, María; Moñino, Pedro; Ruiz, Manuel; Uriarte, Estrella; Vidal, Alfonso

2015-01-01

Low back pain (LBP) symptoms and signs are nonspecific. If required, diagnostic blocks may find the source of pain, but indicators of suspect diagnosis must be defined to identify anatomical targets. To reach a consensus from an expert panel on the indicators for the most common causes of LBP. A 3-round (2 telematic and 1 face-to-face) modified Delphi survey with a questionnaire on 78 evidence-based indicators of 7 LBP etiologies was completed by 23 experts. 98.7% of the questionnaire was consensuated. The most accepted indicators were for zygapophysial joint pain, painful ipsilateral paravertebral palpation, worsening with trunk extension, paravertebral musculature spasm on the affected articulation, and referred pain above the knee, without radicular pattern. For sacroiliac joint pain, unilateral pain when seating, with at least 3 described provoking tests: Approximation; gapping; Patrick's; Gaenslen's; thigh thrust; Fortin finger; and Gillet's tests. For discogenic pain, midline pain that may be provoked by pressure on the spinal processes at the affected level; for quadratus lumborum muscle, painful palpation on both the L1 level paravertebral region, referred to iliac crest, and the iliac crest, referred to greater trochanter. For iliopsoas muscle, pain elicited by thigh flexion, referred to buttock, inguinal region, and anterior thigh. For pyramidal muscle, pain while sitting on the affected side and positive Freiberg's test. For radicular pain, paresthesias and positive Lassègue's test at 60°. Seventy-seven diagnostic suspect indicators of LBP conditions were consensuated. These may facilitate conservative or interventional pain management decision-making. © 2013 World Institute of Pain.

Ultrasound-guided peripheral and truncal blocks in pediatric patients

Directory of Open Access Journals (Sweden)

Mohamed Bilal Delvi

2011-01-01

Full Text Available Ultrasound has added a feather in the cap of the anesthesiologists as real-time nerve localization and drug deposition around the nerve structure under real-time guidance is now a reality, as the saying "seeing is believing" has been proven true with the advent of ultrasound in anesthesia. Pediatric patients are a unique group regarding their anatomical and physiological features in comparison with adults; regional blocks in adults with the anatomical landmark and surface marking are almost uniform across the adult population. The landmark technique in pediatric patients is not reliable in all patients due to the variability in the age and size; the advent of ultrasound in assisting nerve localization has changed the way regional blocks are achieved in children and the range of blocks performed on adults can now be performed on pediatric patients; with advances in the technology and dexterity of ultrasound equipment, the chances of success of blocks has increased with a smaller dose of the local anesthetic in comparison to the traditional methods. Anesthesiologists are now able to perform blocks with more accuracy and avoid complications like intravascular injection and injury to the pleura and peritoneum during routine practice with the assistance of high-frequency transducers and top of the range portable ultrasound machines; catheters can be inserted to provide a continuous analgesia in the postoperative period. This review article describes the common peripheral blocks in pediatric patients; the readers are encouraged to gain experience by attending workshops, hands-on practice under supervision, and conduct random controlled trials pertaining to ultrasound-guided blocks in the pediatric age group. The recent literature is encouraging and further research is promising; a wide range of blocks being described in detail by many prominent experts from all over the world.

Ultrasound-guided paravertebral block for pyloromyotomy in 3 neonates with congenital hypertrophic pyloric stenosis

OpenAIRE

Mata-Gómez, Javier; Guerrero-Domínguez, Rosana; García-Santigosa, Marta; Ontanilla, Antonio

2015-01-01

BACKGROUND AND OBJECTIVES: Hypertrophic pyloric stenosis is a relatively common affection of gastrointestinal tract in childhood that results in symptoms, such as projectile vomiting and metabolic disorders that imply a high risk of aspiration during anesthetic induction. In this way, the carrying out of a technique with general anesthesia and intravenous rapid sequence induction, preoxygenation and cricoid pressure are recommended. After the correction of systemic metabolic alkalosis and pH ...

Increasing Humidity Blocks Continuous Positive Airflow-induced Apnea Responses in Rats

Directory of Open Access Journals (Sweden)

Ching-Ting Tan

2010-07-01

Conclusion: Laryngeal cold dry air stimulation triggered an apneic response, which could be eliminated by humidification but not by the heating of air. These results suggest that using continuous positive airway pressure (CPAP with humidified air decreases CPAP-induced apnea.

Identifying a Small Molecule Blocking Antigen Presentation in Autoimmune Thyroiditis.

Science.gov (United States)

Li, Cheuk Wun; Menconi, Francesca; Osman, Roman; Mezei, Mihaly; Jacobson, Eric M; Concepcion, Erlinda; David, Chella S; Kastrinsky, David B; Ohlmeyer, Michael; Tomer, Yaron

2016-02-19

We previously showed that an HLA-DR variant containing arginine at position 74 of the DRβ1 chain (DRβ1-Arg74) is the specific HLA class II variant conferring risk for autoimmune thyroid diseases (AITD). We also identified 5 thyroglobulin (Tg) peptides that bound to DRβ1-Arg74. We hypothesized that blocking the binding of these peptides to DRβ1-Arg74 could block the continuous T-cell activation in thyroiditis needed to maintain the autoimmune response to the thyroid. The aim of the current study was to identify small molecules that can block T-cell activation by Tg peptides presented within DRβ1-Arg74 pockets. We screened a large and diverse library of compounds and identified one compound, cepharanthine that was able to block peptide binding to DRβ1-Arg74. We then showed that Tg.2098 is the dominant peptide when inducing experimental autoimmune thyroiditis (EAT) in NOD mice expressing human DRβ1-Arg74. Furthermore, cepharanthine blocked T-cell activation by thyroglobulin peptides, in particular Tg.2098 in mice that were induced with EAT. For the first time we identified a small molecule that can block Tg peptide binding and presentation to T-cells in autoimmune thyroiditis. If confirmed cepharanthine could potentially have a role in treating human AITD. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Multi-block methods in multivariate process control

DEFF Research Database (Denmark)

Kohonen, J.; Reinikainen, S.P.; Aaljoki, K.

2008-01-01

methods the effect of a sub-process can be seen and an example with two blocks, near infra-red, NIR, and process data, is shown. The results show improvements in modelling task, when a MB-based approach is used. This way of working with data gives more information on the process than if all data...... are in one X-matrix. The procedure is demonstrated by an industrial continuous process, where knowledge about the sub-processes is available and X-matrix can be divided into blocks between process variables and NIR spectra.......In chemometric studies all predictor variables are usually collected in one data matrix X. This matrix is then analyzed by PLS regression or other methods. When data from several different sub-processes are collected in one matrix, there is a possibility that the effects of some sub-processes may...

Morphological studies on block copolymer modified PA 6 blends

Energy Technology Data Exchange (ETDEWEB)

Poindl, M., E-mail: marcus.poindl@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de; Bonten, C., E-mail: marcus.poindl@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de [Institut für Kunststofftechnik, University of Stuttgart (Germany)

2014-05-15

Recent studies show that compounding polyamide 6 (PA 6) with a PA 6 polyether block copolymers made by reaction injection molding (RIM) or continuous anionic polymerization in a reactive extrusion process (REX) result in blends with high impact strength and high stiffness compared to conventional rubber blends. In this paper, different high impact PA 6 blends were prepared using a twin screw extruder. The different impact modifiers were an ethylene propylene copolymer, a PA PA 6 polyether block copolymer made by reaction injection molding and one made by reactive extrusion. To ensure good particle matrix bonding, the ethylene propylene copolymer was grafted with maleic anhydride (EPR-g-MA). Due to the molecular structure of the two block copolymers, a coupling agent was not necessary. The block copolymers are semi-crystalline and partially cross-linked in contrast to commonly used amorphous rubbers which are usually uncured. The combination of different analysis methods like atomic force microscopy (AFM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) gave a detailed view in the structure of the blends. Due to the partial cross-linking, the particles of the block copolymers in the blends are not spherical like the ones of ethylene propylene copolymer. The differences in molecular structure, miscibility and grafting of the impact modifiers result in different mechanical properties and different blend morphologies.

Comparative Analysis of the Paravertebral Analgesic Pump Catheter with the Epidural Catheter in Elderly Trauma Patients with Multiple Rib Fractures.

Science.gov (United States)

Shapiro, Brian S; Wasfie, Tarik; Chadwick, Mathew; Barber, Kimberly R; Yapchai, Raquel

2017-04-01

Presently, trauma guidelines recommend epidural analgesia as the optimal modality of pain relief from rib fractures. They are not ideally suited for elderly trauma patients and have disadvantages including bleeding risk. The paravertebral analgesic pump (PVP) eliminates such disadvantages and includes ease of placement in the trauma setting. This study compares pain control in patients treated by EPI versus PVP. This is a retrospective, historical cohort study comparing two methods of pain management in the trauma setting. Before 2010, patients who had epidural catheters (EPI) placed for pain control were compared with patients after 2010 in which the PVP was used. All patients had multiple rib fractures as diagnosed by CT scan. Analysis was adjusted for age, number of fractures, and comorbid conditions. Multiple linear regression analysis was conducted to compare average reported pain. A total of 110 patients, 31 PVP and 79 epidural catheters, were included in the study. Overall mean age was 65 years. The mean Injury Severity Score was 12.0 (EPI) and 11.1 (PVP). Mean number rib fractures was 4.29 (EPI) and 4.71 (PVP). PVP was associated with a 30 per cent greater decrease in pain than that seen with EPI (6.0-1.9 vs 6.4-3.4). After controlling for age, Injury Severity Score, and number of rib fractures, there were no differences in intensive care unit or total length of stay (P = 0.35) or in pain score (3.76 vs 3.56, P = 0.64). In conclusion, the PVP compares well with epidural analgesia in older trauma patients yet is safe, well tolerated, and easily inserted.

Oligomers and Polymers Based on Pentacene Building Blocks

Directory of Open Access Journals (Sweden)

Dan Lehnherr

2010-04-01

Full Text Available Functionalized pentacene derivatives continue to provide unique materials for organic semiconductor applications. Although oligomers and polymers based on pentacene building blocks remain quite rare, recent synthetic achievements have provided a number of examples with varied structural motifs. This review highlights recent work in this area and, when possible, contrasts the properties of defined-length pentacene oligomers to those of mono- and polymeric systems.

Continuous spinal anesthesia.

Science.gov (United States)

Moore, James M

2009-01-01

Continuous spinal anesthesia (CSA) is an underutilized technique in modern anesthesia practice. Compared with other techniques of neuraxial anesthesia, CSA allows incremental dosing of an intrathecal local anesthetic for an indefinite duration, whereas traditional single-shot spinal anesthesia usually involves larger doses, a finite, unpredictable duration, and greater potential for detrimental hemodynamic effects including hypotension, and epidural anesthesia via a catheter may produce lesser motor block and suboptimal anesthesia in sacral nerve root distributions. This review compares CSA with other anesthetic techniques and also describes the history of CSA, its clinical applications, concerns regarding neurotoxicity, and other pharmacologic implications of its use. CSA has seen a waxing and waning of its popularity in clinical practice since its initial description in 1907. After case reports of cauda equina syndrome were reported with the use of spinal microcatheters for CSA, these microcatheters were withdrawn from clinical practice in the United States but continued to be used in Europe with no further neurologic sequelae. Because only large-bore catheters may be used in the United States, CSA is usually reserved for elderly patients out of concern for the risk of postdural puncture headache in younger patients. However, even in younger patients, sometimes the unique clinical benefits and hemodynamic stability involved in CSA outweigh concerns regarding postdural puncture headache. Clinical scenarios in which CSA may be of particular benefit include patients with severe aortic stenosis undergoing lower extremity surgery and obstetric patients with complex heart disease. CSA is an underutilized technique in modern anesthesia practice. Perhaps more accurately termed fractional spinal anesthesia, CSA involves intermittent dosing of local anesthetic solution via an intrathecal catheter. Where traditional spinal anesthesia involves a single injection with a

Generalized Block Failure

DEFF Research Database (Denmark)

Jönsson, Jeppe

2015-01-01

Block tearing is considered in several codes as a pure block tension or a pure block shear failure mechanism. However in many situations the load acts eccentrically and involves the transfer of a substantial moment in combination with the shear force and perhaps a normal force. A literature study...... shows that no readily available tests with a well-defined substantial eccentricity have been performed. This paper presents theoretical and experimental work leading towards generalized block failure capacity methods. Simple combination of normal force, shear force and moment stress distributions along...... yield lines around the block leads to simple interaction formulas similar to other interaction formulas in the codes....

Eficacia de la infiltración de ozono paravertebral lumbar y en puntos gatillos como coadyuvante del tratamiento en pacientes con dolor lumbar crónico y lumbociatalgia crónica en el síndrome doloroso miofascial aislado o acompañado de otras patologías

OpenAIRE

E. Silva Jiménez; M. Toro; C. Baíz

2014-01-01

Introducción: Posterior al primer episodio de dolor lumbar, la recurrencia persiste durante un año o más en el 25 al 60 %, afectando a población económicamente activa, causando discapacidad y en 80 % ausentismo laboral. Objetivo: Evaluar el grado de eficacia del uso de la técnica de infiltración con ozono paravertebral lumbar y en puntos gatillos junto al tratamiento farmacológico y rehabilitador, en pacientes con dolor lumbar crónico y lumbociatalgia crónica debido al síndrome doloroso miofa...

Epidural block

Science.gov (United States)

... page: //medlineplus.gov/ency/patientinstructions/000484.htm Epidural block - pregnancy To use the sharing features on this page, please enable JavaScript. An epidural block is a numbing medicine given by injection (shot) ...

Combination Therapy with Continuous Three-in-One Femoral Nerve Block and Periarticular Multimodal Drug Infiltration after Total Hip Arthroplasty

Directory of Open Access Journals (Sweden)

Tomonori Tetsunaga

2016-01-01

Full Text Available Background. Various postoperative pain relief modalities, including continuous femoral nerve block (CFNB, local infiltration analgesia (LIA, and combination therapy, have been reported for total knee arthroplasty. However, no studies have compared CFNB with LIA for total hip arthroplasty (THA. The aim of this study was to compare the efficacy of CFNB versus LIA after THA. Methods. We retrospectively reviewed the postoperative outcomes of 93 THA patients (20 men, 73 women; mean age 69.2 years. Patients were divided into three groups according to postoperative analgesic technique: CFNB, LIA, or combined CFNB+LIA. We measured the following postoperative outcome parameters: visual analog scale (VAS for pain at rest, supplemental analgesia, side effects, mobilization, length of hospital stay, and Harris Hip Score (HHS. Results. The CFNB+LIA group had significantly lower VAS pain scores than the CFNB and LIA groups on postoperative day 1. There were no significant differences among the three groups in use of supplemental analgesia, side effects, mobilization, length of hospital stay, or HHS at 3 months after THA. Conclusions. Although there were no clinically significant differences in outcomes among the three groups, combination therapy with CFNB and LIA provided better pain relief after THA than CFNB or LIA alone, with few side effects.

Amphiphilic block copolymers for biomedical applications

Science.gov (United States)

Zupancich, John Andrew

Amphiphilic block copolymer self-assembly provides a versatile means to prepare nanoscale objects in solution. Control over aggregate shape is granted through manipulation of amphiphile composition and the synthesis of well-defined polymers offers the potential to produce micelles with geometries optimized for specific applications. Currently, polymer micelles are being investigated as vehicles for the delivery of therapeutics and attempts to increase efficacy has motivated efforts to incorporate bioactive ligands and stimuli-responsive character into these structures. This thesis reports the synthesis and self-assembly of biocompatible, degradable polymeric amphiphiles. Spherical, cylindrical, and bilayered vesicle structures were generated spontaneously by the direct dispersion of poly(ethylene oxide)-b-poly(gamma-methyl-ε-caprolactone) block copolymers in water and solutions were characterized with cryogenic transmission electron microscopy (cryo-TEM). The dependence of micelle structure on diblock copolymer composition was examined through the systematic variation of the hydrophobic block molecular weight. A continuous evolution of morphology was observed with coexistence of aggregate structures occurring in windows of composition intermediate to that of pure spheres, cylinders and vesicles. A number of heterobifunctional poly(ethylene oxide) polymers were synthesized for the preparation of ligand-functionalized amphiphilic diblock copolymers. The effect of ligand conjugation on block copolymer self-assembly and micelle morphology was also examined. An RGD-containing peptide sequence was efficiently conjugated to a set of well characterized poly(ethylene oxide)-b-poly(butadiene) copolymers. The reported aggregate morphologies of peptide-functionalized polymeric amphiphiles deviated from canonical structures and the micelle clustering, cylinder fragmentation, network formation, and multilayer vesicle generation documented with cryo-TEM was attributed to

Supramolecular self-assembly and opto-electronic properties of semiconducting block copolymers

NARCIS (Netherlands)

Boer, Bert de; Stalmach, Ulf; Hutten, Paul F. van; Melzer, Christian; Krasnikov, Victor V.; Hadziioannou, Georges

2001-01-01

With continuous and nanometre-scale interpenetrating phases of electron donor and acceptor components, a novel diblock copolymer, in which one block is poly(p-phenylene vinylene) (PPV) and the other is a C60-functionalized polystyrene, is designed to be an efficient photovoltaic material. The

Design and Synthesis of Network-Forming Triblock Copolymers Using Tapered Block Interfaces

Science.gov (United States)

Kuan, Wei-Fan; Roy, Raghunath; Rong, Lixia; Hsiao, Benjamin S.; Epps, Thomas H.

2012-01-01

We report a strategy for generating novel dual-tapered poly(isoprene-b-isoprene/styrene-b-styrene-b-styrene/methyl methacrylate-b-methyl methacrylate) [P(I-IS-S-SM-M)] triblock copolymers that combines anionic polymerization, atom transfer radical polymerization (ATRP), and Huisgen 1,3-dipolar cycloaddition click chemistry. The tapered interfaces between blocks were synthesized via a semi-batch feed using programmable syringe pumps. This strategy allows us to manipulate the transition region between copolymer blocks in triblock copolymers providing control over the interfacial interactions in our nanoscale phase-separated materials independent of molecular weight and block constituents. Additionally, we show the ability to retain a desirous and complex multiply-continuous network structure (alternating gyroid) in our dual-tapered triblock material. PMID:23066522

Multistep Continuous-Flow Synthesis in Medicinal Chemistry

DEFF Research Database (Denmark)

Petersen, Trine P; Mirsharghi, Sahar; Rummel, Pia Cwarzko

2013-01-01

A three-step continuous-flow synthesis system and its application to the assembly of a new series of chemokine receptor ligands directly from commercial building blocks is reported. No scavenger columns or solvent switches are necessary to recover the desired test compounds, which were obtained i...... studies in medicinal chemistry....

Homogeneous bilateral block shifts

Indian Academy of Sciences (India)

Douglas class were classified in [3]; they are unilateral block shifts of arbitrary block size (i.e. dim H(n) can be anything). However, no examples of irreducible homogeneous bilateral block shifts of block size larger than 1 were known until now.

CO2 permeation properties of poly(ethylene oxide)-based segmented block copolymers

NARCIS (Netherlands)

Husken, D.; Visser, Tymen; Wessling, Matthias; Gaymans, R.J.

2010-01-01

This paper discusses the gas permeation properties of poly(ethylene oxide) (PEO)-based segmented block copolymers containing monodisperse amide segments. These monodisperse segments give rise to a well phase-separated morphology, comprising a continuous PEO phase with dispersed crystallised amide

Detection block

International Nuclear Information System (INIS)

Bezak, A.

1987-01-01

A diagram is given of a detection block used for monitoring burnup of nuclear reactor fuel. A shielding block is an important part of the detection block. It stabilizes the fuel assembly in the fixing hole in front of a collimator where a suitable gamma beam is defined for gamma spectrometry determination of fuel burnup. The detector case and a neutron source case are placed on opposite sides of the fixing hole. For neutron measurement for which the water in the tank is used as a moderator, the neutron detector-fuel assembly configuration is selected such that neutrons from spontaneous fission and neutrons induced with the neutron source can both be measured. The patented design of the detection block permits longitudinal travel and rotation of the fuel assembly to any position, and thus more reliable determination of nuclear fuel burnup. (E.S.). 1 fig

Synthesis of amylose-block-polystyrene rod-coil block copolymers

NARCIS (Netherlands)

Loos, Katja; Stadler, Reimund

1997-01-01

In the present communication we demonstrate the synthesis of a hybrid block copolymer based on the combination of a biopolymer (amylose) with a synthetic block (polystyrene). To obtain such materials, amino-functionalized polymers were modified with maltoheptaose moieties that serve as initiators

Neurotrophic and X-ray blocks in the blastemal cell cycle

International Nuclear Information System (INIS)

Maden, M.

1979-01-01

Using microdensitometry techniques the points in the cycle where blastemal cells become blocked after X-irradiation or denervation of the regenerating amphibian limb have been identified. X-irradiation blocks cells in both G 1 and G 2 and those cells that were in S at the time of irradiation presumably proceed to G 2 . After denervation, however, cells accumulate only in G 1 and those that were in S or G 2 continue through the cycle to the next G 1 . The latter results are clearly contradictory to a recent theory proposing a G 2 neurotrophic control of blastemal cells and a solution to the contradiction is presented in the light of the recent results. (author)

Perioperative management of an elderly patient of hypertrophic obstructive cardiomyopathy for knee arthroplasty and the role of peripheral nerve blocks

Directory of Open Access Journals (Sweden)

Sunny Rupal

2013-01-01

Full Text Available This case report exemplifies how the anaesthetic technique of general anesthesia with continuous bilateral femoral nerve block for bilateral knee arthroplasty was well chosen for the management of perioperative complications in an elderly patient with hypertrophic obstructive cardiomyopathy (HOCM. A 69-year-old female patient of HOCM was scheduled for bilateral total knee replacement. Echocardiography revealed severe left ventricular outflow tract obstruction with peak systolic gradient of 56 mmHg. The surgery was conducted under general anaesthesia with invasive monitoring and bilateral continuous femoral nerve blocks for postoperative analgesia. Postoperatively, she developed pulmonary oedema due to the liberal administration of fluids. This complication was successfully managed without interrupting the management of pain. Management of patients with HOCM for noncardiac surgery requires knowledge of variable presentation of two forms of disease. Also, this case report highlights the practical advantage of continuous femoral nerve block (CFNBs over epidural anaesthesia.

Influence of anchor block size on the thickness of adsorbed block copolymer layers

NARCIS (Netherlands)

Belder, G.F; ten Brinke, G.; Hadziioannou, G

1997-01-01

We present surface force data on three different polystyrene/poly(2-vinylpyridine) block copolymers (PS/P2VP) with a fixed size of the nonadsorbing PS block but widely varying sizes of the adsorbing P2VP block. With respect to the sizes of the two blocks, they range from moderately to highly

Should continuous rather than single-injection interscalene block be routinely offered for major shoulder surgery? A meta-analysis of the analgesic and side-effects profiles.

Science.gov (United States)

Vorobeichik, L; Brull, R; Bowry, R; Laffey, J G; Abdallah, F W

2018-04-01

Major shoulder surgery is associated with moderate-to-severe pain, but consensus on the optimal analgesic approach is lacking. Continuous catheter-based interscalene block (CISB) prolongs the analgesic benefits of its single-injection counterpart (SISB), but concerns over CISB complications and difficulties in interpreting comparative evidence examining major and minor shoulder procedures simultaneously, despite their differences in postoperative pain, have limited CISB popularity. This meta-analysis evaluates the CISB analgesic role and complications compared with SISB for major shoulder surgery. We retrieved randomised controlled trials (RCTs) comparing the effects of CISB to SISB on analgesic outcomes and side-effects after major shoulder surgery. Postoperative opioid consumption at 24 h was designated as the primary outcome. Secondary outcomes included 24-48 h opioid consumption, postoperative rest and dynamic pain scores up to 72 h, time-to-first analgesic, recovery room and hospital stay durations, patient satisfaction, postoperative nausea and vomiting, respiratory function, and block-related complications. Data from 15 RCTs were pooled using random-effects modelling. Compared with SISB, CISB reduced 24- and 48-h oral morphine consumption by a weighted mean difference [95% confidence interval] of 50.9 mg [-81.6, -20.2], (P=0.001) and 44.7 mg [-80.9, -8.7], (Pshoulder surgery, without increasing side-effects, compared with SISB. The importance of CISB-related changes in respiratory indices is questionable. Copyright © 2017 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.

Combined KHFAC + DC nerve block without onset or reduced nerve conductivity after block

Science.gov (United States)

Franke, Manfred; Vrabec, Tina; Wainright, Jesse; Bhadra, Niloy; Bhadra, Narendra; Kilgore, Kevin

2014-10-01

Objective. Kilohertz frequency alternating current (KHFAC) waveforms have been shown to provide peripheral nerve conductivity block in many acute and chronic animal models. KHFAC nerve block could be used to address multiple disorders caused by neural over-activity, including blocking pain and spasticity. However, one drawback of KHFAC block is a transient activation of nerve fibers during the initiation of the nerve block, called the onset response. The objective of this study is to evaluate the feasibility of using charge balanced direct current (CBDC) waveforms to temporarily block motor nerve conductivity distally to the KHFAC electrodes to mitigate the block onset-response. Approach. A total of eight animals were used in this study. A set of four animals were used to assess feasibility and reproducibility of a combined KHFAC + CBDC block. A following randomized study, conducted on a second set of four animals, compared the onset response resulting from KHFAC alone and combined KHFAC + CBDC waveforms. To quantify the onset, peak forces and the force-time integral were measured during KHFAC block initiation. Nerve conductivity was monitored throughout the study by comparing muscle twitch forces evoked by supra-maximal stimulation proximal and distal to the block electrodes. Each animal of the randomized study received at least 300 s (range: 318-1563 s) of cumulative dc to investigate the impact of combined KHFAC + CBDC on nerve viability. Main results. The peak onset force was reduced significantly from 20.73 N (range: 18.6-26.5 N) with KHFAC alone to 0.45 N (range: 0.2-0.7 N) with the combined CBDC and KHFAC block waveform (p conductivity was observed after application of the combined KHFAC + CBDC block relative to KHFAC waveforms. Significance. The distal application of CBDC can significantly reduce or even completely prevent the KHFAC onset response without a change in nerve conductivity.

Effect of transversus abdominis plane block on cost of laparoscopic cholecystectomy anesthesia.

Science.gov (United States)

Kokulu, Serdar; Bakı, Elif Doğan; Kaçar, Emre; Bal, Ahmet; Şenay, Hasan; Üstün, Kübra Demir; Yılmaz, Sezgin; Ela, Yüksel; Sıvacı, Remziye Gül

2014-12-23

Use of transversus abdominis plane (TAP) block for postoperative analgesia is continuously increasing. However, few studies have investigated intraoperative effects of TAP block. We aimed to study the effects of TAP block in terms of cost-effectiveness and consumption of inhalation agents. Forty patients undergoing laparoscopic cholecystectomy were enrolled in this study. Patients were randomly divided into 2 groups: Group 1 (n=20) patients received TAP block and Group 2 (n=20) patients did not receive TAP block. Standard anesthesia induction was used in all patients. For the maintenance of anesthesia, fractional inspired oxygen (FIO2) of 50% in air with desflurane was used with a fresh gas flow of 4 L/min. All patients were monitored with electrocardiography and for peripheral oxygen saturation (SpO2), end-tidal carbon dioxide (ET), heart rate (HR), noninvasive mean blood pressure (MBP), and bispectral index (BIS). Bilateral TAP blocks were performed under ultrasound guidance to Group 1 patients. The BIS value was maintained at between 40 and 50 during the surgery. The Dion formula was used to calculate consumption of desflurane for each patient. There was no difference between the groups with respect to demographic characteristics of the patients. Duration of anesthesia, surgery time, and dosage of fentanyl were similar in the 2 groups. However, the cost and consumption of desflurane was significantly lower in Group 1. Total anesthesia consumption was lower and the cost-effectiveness of anesthesia was better in TAP block patients with general anesthesia than in non-TAP block patients undergoing laparoscopic cholecystectomy.

Abdominal wall blocks in adults

DEFF Research Database (Denmark)

Børglum, Jens; Gögenür, Ismail; Bendtsen, Thomas F

2016-01-01

been introduced with success. Future research should also investigate the effect of specific abdominal wall blocks on neuroendocrine and inflammatory stress response after surgery.  Summary USG abdominal wall blocks in adults are commonplace techniques today. Most abdominal wall blocks are assigned......Purpose of review Abdominal wall blocks in adults have evolved much during the last decade; that is, particularly with the introduction of ultrasound-guided (USG) blocks. This review highlights recent advances of block techniques within this field and proposes directions for future research.......  Recent findings Ultrasound guidance is now considered the golden standard for abdominal wall blocks in adults, even though some landmark-based blocks are still being investigated. The efficiency of USG transversus abdominis plane blocks in relation to many surgical procedures involving the abdominal wall...

Fermion-scalar conformal blocks

Energy Technology Data Exchange (ETDEWEB)

Iliesiu, Luca [Joseph Henry Laboratories, Princeton University,Washington Road, Princeton, NJ 08544 (United States); Kos, Filip [Department of Physics, Yale University,217 Prospect Street, New Haven, CT 06520 (United States); Poland, David [Department of Physics, Yale University,217 Prospect Street, New Haven, CT 06520 (United States); School of Natural Sciences, Institute for Advanced Study,1 Einstein Dr, Princeton, New Jersey 08540 (United States); Pufu, Silviu S. [Joseph Henry Laboratories, Princeton University,Washington Road, Princeton, NJ 08544 (United States); Simmons-Duffin, David [School of Natural Sciences, Institute for Advanced Study,1 Einstein Dr, Princeton, New Jersey 08540 (United States); Yacoby, Ran [Joseph Henry Laboratories, Princeton University,Washington Road, Princeton, NJ 08544 (United States)

2016-04-13

We compute the conformal blocks associated with scalar-scalar-fermion-fermion 4-point functions in 3D CFTs. Together with the known scalar conformal blocks, our result completes the task of determining the so-called ‘seed blocks’ in three dimensions. Conformal blocks associated with 4-point functions of operators with arbitrary spins can now be determined from these seed blocks by using known differential operators.

High-efficiency Gaussian key reconciliation in continuous variable quantum key distribution

Science.gov (United States)

Bai, ZengLiang; Wang, XuYang; Yang, ShenShen; Li, YongMin

2016-01-01

Efficient reconciliation is a crucial step in continuous variable quantum key distribution. The progressive-edge-growth (PEG) algorithm is an efficient method to construct relatively short block length low-density parity-check (LDPC) codes. The qua-sicyclic construction method can extend short block length codes and further eliminate the shortest cycle. In this paper, by combining the PEG algorithm and qua-si-cyclic construction method, we design long block length irregular LDPC codes with high error-correcting capacity. Based on these LDPC codes, we achieve high-efficiency Gaussian key reconciliation with slice recon-ciliation based on multilevel coding/multistage decoding with an efficiency of 93.7%.

Block Cipher Analysis

DEFF Research Database (Denmark)

Miolane, Charlotte Vikkelsø

ensurethat no attack violatesthe securitybounds specifiedbygeneric attack namely exhaustivekey search and table lookup attacks. This thesis contains a general introduction to cryptography with focus on block ciphers and important block cipher designs, in particular the Advanced Encryption Standard(AES...... on small scale variants of AES. In the final part of the thesis we present a new block cipher proposal Present and examine its security against algebraic and differential cryptanalysis in particular....

Comparison of analgesic efficacy of four-quadrant transversus abdominis plane (TAP) block and continuous posterior TAP analgesia with epidural analgesia in patients undergoing laparoscopic colorectal surgery: an open-label, randomised, non-inferiority trial.

Science.gov (United States)

Niraj, G; Kelkar, A; Hart, E; Horst, C; Malik, D; Yeow, C; Singh, B; Chaudhri, S

2014-04-01

Posterior transversus abdominis plane blocks have been reported to be an effective method of providing analgesia after lower abdominal surgery. We compared the efficacy of a novel technique of providing continuous transversus abdominis plane analgesia with epidural analgesia in patients on an enhanced recovery programme following laparoscopic colorectal surgery. A non-inferiority comparison was used. Adult patients undergoing elective laparoscopic colorectal surgery were randomly assigned to receive continuous transversus abdominis plane analgesia (n = 35) vs epidural analgesia (n = 35), in addition to a postoperative analgesic regimen comprising regular paracetamol, regular diclofenac and tramadol as required. Sixty-one patients completed the study. The transversus group received four-quadrant transversus abdominis plane blocks and bilateral posterior transversus abdominis plane catheters that were infused with levobupivacaine 0.25% for 48 h. The epidural group received an infusion of bupivacaine and fentanyl. The primary outcome measure was visual analogue scale pain score on coughing at 24 h after surgery. We found no significant difference in median (IQR [range]) visual analogue scores during coughing at 24 h between the transversus group 2.5 (1.0-3.0 [0-5.5]) and the epidural group 2.5 (1.0-5.0 [0-6.0]). The one-sided 97.5% CI was a 0.0 (∞-1.0) difference in means, establishing non-inferiority. There were no significant differences between the groups for tramadol consumption. Success rate was 28/30 (93%) in the transversus group vs 27/31 (87%) in the epidural group. Continuous transversus abdominis plane infusion was non-inferior to epidural infusion in providing analgesia after laparoscopic colorectal surgery. © 2013 The Association of Anaesthetists of Great Britain and Ireland.

A Four-Step Block Hybrid Adams-Moulton Methods For The Solution ...

African Journals Online (AJOL)

This paper examines application of the Adam-Moulton's Method and proposes a modified self-starting continuous formula Called hybrid Adams-Moulton methods for the case k=4. It allows evaluation at both grid and off grid points to obtain the discrete schemes used in the block methods. The order, error constant and ...

Main-chain supramolecular block copolymers.

Science.gov (United States)

Yang, Si Kyung; Ambade, Ashootosh V; Weck, Marcus

2011-01-01

Block copolymers are key building blocks for a variety of applications ranging from electronic devices to drug delivery. The material properties of block copolymers can be tuned and potentially improved by introducing noncovalent interactions in place of covalent linkages between polymeric blocks resulting in the formation of supramolecular block copolymers. Such materials combine the microphase separation behavior inherent to block copolymers with the responsiveness of supramolecular materials thereby affording dynamic and reversible materials. This tutorial review covers recent advances in main-chain supramolecular block copolymers and describes the design principles, synthetic approaches, advantages, and potential applications.

Ultrasound guided supraclavicular block.

LENUS (Irish Health Repository)

Hanumanthaiah, Deepak

2013-09-01

Ultrasound guided regional anaesthesia is becoming increasingly popular. The supraclavicular block has been transformed by ultrasound guidance into a potentially safe superficial block. We reviewed the techniques of performing supraclavicular block with special focus on ultrasound guidance.

Die design and process optimization of die cast V6 engine blocks

Directory of Open Access Journals (Sweden)

Henry Hu

2005-02-01

Full Text Available The use of aluminum, particularly for engine blocks, has grown considerably in the past ten years, and continues to rise in the automotive industry. In order to enhance the quality and engineering functionality of die cast engine blocks, die design and processes have to be optimized. In this study, a computer simulation software, MAGMAsoft, as an advanced tool for optimizing die design and casting process, was emplooyed to virtually visualize cavity filling and patterns of a V6 engine block. The original die design and process was simulated first to establish a baseline. A reality check was used to verify the predicted results. Then, the die modification with a different unner system was made by using a CAD software, Unigraphics (UG. The simulation on combinations of the modified die design and revised process was performed to examine the effect of die modification and process change on flow filling of V6 engine blocks. The simulated prediction indicateds that the enhancement of cavity filling due to the die and process modification minimizeds the occurrence of defects during casting, and consequently improves the quality of blocks. The results of mechanical testing show a significant increase in fatigue strengths, and a moderately improvement on tensile properties for the blocks die cast with the new die design and prpocess in comparison with those produced by the original ones.

Generation and Development of Paravertebral Ossification in Cervical Artificial Disk Replacement: A Detailed Analytic Report Using Coronal Reconstruction CT.

Science.gov (United States)

Tian, Wei; Han, Xiao; Liu, Bo; He, Da; Lv, Yanwei; Yue, James

2017-04-01

A retrospective follow-up study and review of images in published papers. To determine whether true heterotopic ossification (HO) occurs in artificial disk replacement (ADR); to evaluate the incidence of paravertebral ossification (PO) and its influence on ADR. HO is typically defined as the abnormal formation of true bone within extraskeletal soft tissues. However, HO in ADR does not fit this definition precisely, as it originates from vertebral body, making it hard to distinguish radiologically from preexisting osteophytes. In this study, the term used for bone formation around ADR is PO. First, all images in the published papers were evaluated as to whether the presented PO in ADR fit the classic definition of HO or osteophytes. Second, we studied 37 consecutive patients who underwent ADR and follow-up for minimum 24 months. The preoperative and follow-up incidence of PO and its influence on range of motion were evaluated using x-ray and computed tomography. All 52 images of PO were found adjacent to the disk in 1 segment rather than entire cervical spine. Fifty (96.2%) of the POs were found to originate from the vertebral body rather than in the soft tissue. A total of 31 patients were included in the follow-up study. No significant difference was found in the incidence of PO between the follow-up and preoperation (61.29% vs. 48.39%, P>0.05). The range of motion of the ADR segment in patients with progressed PO (7.44±4.64 degrees) was significantly lower than that of patients with stable PO grade (12.13±4.42 degrees, P<0.01) at last follow-up. A proportion of HO might in fact be the natural development of preoperative osteophytes, which is unrelated to ADR; the remaining HO might be due to changes in biomechanical environment after surgery, which promotes the grade of osteophytes and affects the segment motion.

Effects of Cocos Ridge Collision on the Western Caribbean: Is there a Panama Block?

Science.gov (United States)

Kobayashi, D.; La Femina, P. C.; Geirsson, H.; Chichaco, E.; Abrego M, A. A.; Fisher, D. M.; Camacho, E. I.

2011-12-01

It has been recognized that the subduction and collision of the Cocos Ridge, a 2 km high aseismic ridge standing on >20 km thick oceanic crust of the Cocos plate, drives upper plate deformation in southern Central America. Recent studies of Global Positioning System (GPS) derived horizontal velocities relative to the Caribbean Plate showed a radial pattern centered on the Cocos Ridge axis where Cocos-Caribbean convergence is orthogonal, and margin-parallel velocities to the northwest. Models of the full three-dimensional GPS velocity field and earthquake slip vectors demonstrate low mechanical coupling along the Middle America subduction zone in Nicaragua and El Salvador, and a broad zone of high coupling beneath the Osa Peninsula, where the Cocos Ridge intersects the margin. These results suggest that Cocos Ridge collision may be the main driver for trench-parallel motion of the fore arc to the northwest and for uplift and shortening of the outer fore arc in southern Central America, whereby thickened and hence buoyant Cocos Ridge crust acts as an indenter causing the tectonic escape of the fore arc. These studies, however, were not able to constrain well the pattern of surface deformation east-southeast of the ridge axis due to a lack of GPS stations, and Cocos Ridge collision may be responsible for the kinematics and deformation of the proposed Panama block. Recent reinforcement of the GPS network in southeastern Costa Rica and Panama has increased the spatial and temporal resolution of the network and made it possible to further investigate surface deformation of southern Central America and the Panama block. We present a new regional surface velocity field for Central America from geodetic GPS data collected at 11 recently-installed and 178 existing episodic, semi-continuous, and continuous GPS sites in Nicaragua, Costa Rica, and Panama. We investigate the effects of Cocos Ridge collision on the Panama block through kinematic block modeling. Published

Paleomagnetic evidence for the continuity and independent movement of a distinct major crustal block in the southern Appalachians

International Nuclear Information System (INIS)

Ellwood, B.B.

1982-01-01

The magnetization of 22 granitic and gneissic southern Appalachian rock units, with estimated cooling ages of 415--250 m.y., has been determined. Included are 842 samples from 114 sites within 19 granites (100 sites) and 3 gneisses (14 sites) located in North Carolina, South Carolina, and Georgia. Data for units which cooled to temperatures 0 C between 350--240 m.y., a period of apparently only slight North American plate motion, can be divided into two groups. A mean paleopole calculated for the first of these groups, group A (derived from six granites and gneisses 365--325 m.y. in age), located in the vicinity of Atlanta, Ga., is coincident with well-defined Lower Carboniferous North American paleopoles. Site paleolatitude is estimated to be approx.11 0 S. Group B granites (six units) range in age from 350--250 m.y., are located to the SE of an arc drawn from Columbia, S.C., through Athens, Ga., to Macon, Ga., are apparently anomalous, and lie in a crustal block >20,000 km 2 in size. A mean paleopole for this group, with corrections for maximum tilt estimates, exhibits good precision but has a paleosite latitude of approx.10 0 N. Without tilt correction the paleopole for group B still exhibits an anomalous paleosite latitude of approx.4 0 N. These data indicate that the group B block (Elberton-Sparta Crustal Block) lying to the SE has an apparent paleosite latitude corresponding to magnetization at a location to the north of the zone containing group A units

Adductor Canal Block With Continuous Infusion Versus Intermittent Boluses and Morphine Consumption

DEFF Research Database (Denmark)

Jaeger, Pia; Baggesgaard, Jonas; Sørensen, Johan K

2018-01-01

a randomized, blinded, controlled study, including patients scheduled for total knee arthroplasty with spinal anesthesia. Patients received 0.2% ropivacaine via a catheter in the adductor canal administered as either repeated intermittent boluses (21 mL/3 h) or continuous infusion (7 mL/h). The primary outcome...

Adductor Canal Block versus Femoral Nerve Block and Quadriceps Strength

DEFF Research Database (Denmark)

Jæger, Pia Therese; Nielsen, Zbigniew Jerzy Koscielniak; Henningsen, Lene Marianne

2013-01-01

: The authors hypothesized that the adductor canal block (ACB), a predominant sensory blockade, reduces quadriceps strength compared with placebo (primary endpoint, area under the curve, 0.5-6 h), but less than the femoral nerve block (FNB; secondary endpoint). Other secondary endpoints were...

Traveling Rocky Roads: The Consequences of Transcription-Blocking DNA Lesions on RNA Polymerase II.

Science.gov (United States)

Steurer, Barbara; Marteijn, Jurgen A

2017-10-27

The faithful transcription of eukaryotic genes by RNA polymerase II (RNAP2) is crucial for proper cell function and tissue homeostasis. However, transcription-blocking DNA lesions of both endogenous and environmental origin continuously challenge the progression of elongating RNAP2. The stalling of RNAP2 on a transcription-blocking lesion triggers a series of highly regulated events, including RNAP2 processing to make the lesion accessible for DNA repair, R-loop-mediated DNA damage signaling, and the initiation of transcription-coupled DNA repair. The correct execution and coordination of these processes is vital for resuming transcription following the successful repair of transcription-blocking lesions. Here, we outline recent insights into the molecular consequences of RNAP2 stalling on transcription-blocking DNA lesions and how these lesions are resolved to restore mRNA synthesis. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Asymmetric PS-block-(PS-co-PB)-block-PS block copolymers: morphology formation and deformation behaviour

International Nuclear Information System (INIS)

Adhikari, Rameshwar; Huy, Trinh An; Buschnakowski, Matthias; Michler, Goerg H; Knoll, Konrad

2004-01-01

Morphology formation and deformation behaviour of asymmetric styrene/butadiene triblock copolymers (total polystyrene (PS) content ∼70%) consisting of PS outer blocks held apart by a styrene-co-butadiene random copolymer block (PS-co-PB) each were investigated. The techniques used were differential scanning calorimetry, transmission electron microscopy, uniaxial tensile testing and Fourier-transform infrared spectroscopy. A significant shift of the phase behaviour relative to that of a neat symmetric triblock copolymer was observed, which can be attributed to the asymmetric architecture and the presence of PS-co-PB as a soft block. The mechanical properties and the microdeformation phenomena were mainly controlled by the nature of their solid-state morphology. Independent of morphology type, the soft phase was found to deform to a significantly higher degree of orientation when compared with the hard phase

Ultrasound description of Pecs II (modified Pecs I): a novel approach to breast surgery.

Science.gov (United States)

Blanco, R; Fajardo, M; Parras Maldonado, T

2012-11-01

The Pecs block (pectoral nerves block) is an easy and reliable superficial block inspired by the infraclavicular block approach and the transversus abdominis plane blocks. Once the pectoralis muscles are located under the clavicle the space between the two muscles is dissected to reach the lateral pectoral and the medial pectoral nerves. The main indications are breast expanders and subpectoral prosthesis where the distension of these muscles is extremely painful. A second version of the Pecs block is described, called "modified Pecs block" or Pecs block type II. This novel approach aims to block at least the pectoral nerves, the intercostobrachial, intercostals III-IV-V-VI and the long thoracic nerve. These nerves need to be blocked to provide complete analgesia during breast surgery, and it is an alternative or a rescue block if paravertebral blocks and thoracic epidurals failed. This block has been used in our unit in the past year for the Pecs I indications described, and in addition for, tumorectomies, wide excisions, and axillary clearances. The ultrasound sequence to perform this block is shown, together with simple X-ray dye images and gadolinium MRI images to understand the spread and pathways that can explain the benefit of this novel approach. Copyright © 2012 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

Adductor canal block versus femoral nerve block for analgesia after total knee arthroplasty

DEFF Research Database (Denmark)

Jaeger, Pia; Zaric, Dusanka; Fomsgaard, Jonna Storm

2013-01-01

Femoral nerve block (FNB), a commonly used postoperative pain treatment after total knee arthroplasty (TKA), reduces quadriceps muscle strength essential for mobilization. In contrast, adductor canal block (ACB) is predominately a sensory nerve block. We hypothesized that ACB preserves quadriceps...

Implementasi Highly Available Website Dengan Distributed Replicated Block Device

Directory of Open Access Journals (Sweden)

Mulyanto Mulyanto

2016-07-01

Full Text Available As an important IT infrastructure, website is a system which requires high reliability and availability levels. Website meets the criteria as a highly available system because website must provide services to clients in real time, handle a large amount of data, and not lose data during transaction. A highly available system must meet the condition of being able to run continuously as well as guaranteeing consistency on data requests. This study designed a website with high availability. The approach was building network cluster with failover and replicated block device functions. Failover was built to provide service availability, while replicated block device provides data consistency during failure of service.  With failover cluster and replicated block device approaches, a cluster which is able to handle service failures of web server and database server on the website. The result of this study was the services of the website could run well if there was any failure in node members of the cluster. The system was able to provide 99,999 (five nines availability on database server services and 99,98  (three nines on web server services.

Block That Pain!

Science.gov (United States)

Skip Navigation Bar Home Current Issue Past Issues Block That Pain! Past Issues / Fall 2007 Table of ... contrast, most pain relievers used for surgical procedures block activity in all types of neurons. This can ...

Continuous-Flow Biochips: Technology, Physical Design Methods and Testing

DEFF Research Database (Denmark)

Pop, Paul; Araci, Ismail Emre; Chakrabarty, Krishnendu

2015-01-01

This article is a tutorial on continuous-flow biochips where the basic building blocks are microchannels, and microvalves, and by combining them, more complex units such as mixers, switches, and multiplexers can be built. It also presents the state of the art in flow-based biochip technology...

Transversus abdominis plane block in renal allotransplant recipients: A retrospective chart review.

Science.gov (United States)

Gopwani, S R; Rosenblatt, M A

2016-01-01

The efficacy of the transversus abdominis plane (TAP) block appears to vary considerably, depending on the surgical procedure and block technique. This study aims to add to the existing literature and provide a more clear understanding of the TAP blocks role as a postoperative analgesic technique, specifically in renal allotransplant recipients. A retrospective chart review was conducted by querying the intraoperative electronic medical record system of a 1200-bed tertiary academic hospital over a 5 months period, and reviewing anesthetic techniques, as well as postoperative morphine equivalent consumption. Fifty renal allotransplant recipients were identified, 13 of whom received TAP blocks while 37 received no regional analgesic technique. All blocks were performed under ultrasound guidance, with 20 mL of 0.25% bupivacaine injected in the transversus abdominis fascial plane under direct visualization. The primary outcome was postoperative morphine equivalent consumption. Morphine consumption was compared with the two-tailed Mann-Whitney U -test. Continuous variables of patient baseline characteristics were analyzed with unpaired t -test and categorical variables with Fischer Exact Test. A P consumption was found in the group that received the TAP block at 6 h (2.46 mg vs. 7.27 mg, P = 0.0010), 12 h (3.88 mg vs. 10.20 mg, P = 0.0005), 24 h (6.96 mg vs. 14.75 mg, P = 0.0013), and 48 h (11 mg vs. 20.13 mg, P = 0.0092). The TAP block is a beneficial postoperative analgesic, opiate-sparing technique in renal allotransplant recipients.

Bundle Branch Block

Science.gov (United States)

... known cause. Causes can include: Left bundle branch block Heart attacks (myocardial infarction) Thickened, stiffened or weakened ... myocarditis) High blood pressure (hypertension) Right bundle branch block A heart abnormality that's present at birth (congenital) — ...

A randomized trial comparing surgeon-administered intraoperative transversus abdominis plane block with anesthesiologist-administered transcutaneous block.

Science.gov (United States)

Narasimhulu, D M; Scharfman, L; Minkoff, H; George, B; Homel, P; Tyagaraj, K

2018-04-27

Injection of local anesthetic into the transversus abdominis plane (TAP block) decreases systemic morphine requirements after abdominal surgery. We compared intraoperative surgeon-administered TAP block (surgical TAP) to anesthesiologist-administered transcutaneous ultrasound-guided TAP block (conventional TAP) for post-cesarean analgesia. We hypothesized that surgical TAP blocks would take less time to perform than conventional TAP blocks. We performed a randomized trial, recruiting 41 women undergoing cesarean delivery under neuraxial anesthesia, assigning them to either surgical TAP block (n=20) or conventional TAP block (n=21). Time taken to perform the block was the primary outcome, while postoperative pain scores and 24-hour opioid requirements were secondary outcomes. Student's t-test was used to compare block time and Kruskal-Wallis test opioid consumption and pain-scores. Time taken to perform the block (2.4 vs 12.1 min, P consumption (P=0.17) and postoperative pain scores at 4, 8, 24 and 48 h were not significantly different between the groups. Surgical TAP blocks are feasible and less time consuming than conventional TAP blocks, while providing comparable analgesia after cesarean delivery. Copyright © 2018 Elsevier Ltd. All rights reserved.

Influence of Chirality in Ordered Block Copolymer Phases

Science.gov (United States)

Prasad, Ishan; Grason, Gregory

2015-03-01

Block copolymers are known to assemble into rich spectrum of ordered phases, with many complex phases driven by asymmetry in copolymer architecture. Despite decades of study, the influence of intrinsic chirality on equilibrium mesophase assembly of block copolymers is not well understood and largely unexplored. Self-consistent field theory has played a major role in prediction of physical properties of polymeric systems. Only recently, a polar orientational self-consistent field (oSCF) approach was adopted to model chiral BCP having a thermodynamic preference for cholesteric ordering in chiral segments. We implement oSCF theory for chiral nematic copolymers, where segment orientations are characterized by quadrupolar chiral interactions, and focus our study on the thermodynamic stability of bi-continuous network morphologies, and the transfer of molecular chirality to mesoscale chirality of networks. Unique photonic properties observed in butterfly wings have been attributed to presence of chiral single-gyroid networks, this has made it an attractive target for chiral metamaterial design.

Thinking Outside the Block: An Innovative Alternative to 4X4 Block Scheduling.

Science.gov (United States)

Frank, Myra

2002-01-01

Introduces a 4x1 block scheduling method that was developed as an alternative to 4x4 block scheduling. Schedules Fridays for summer school, test preparation, and enrichment and elective courses. Includes suggestions on how to alleviate drawbacks of the 4x1 block schedule. (YDS)

Distribution of short block copolymer chains in Binary Blends of Block Copolymers Having Hydrogen Bonding

Science.gov (United States)

Kwak, Jongheon; Han, Sunghyun; Kim, Jin Kon

2014-03-01

A binary mixture of two block copolymers whose blocks are capable of forming the hydrogen bonding allows one to obtain various microdomains that could not be expected for neat block copolymer. For instance, the binary blend of symmetric polystyrene-block-poly(2-vinylpyridine) copolymer (PS-b-P2VP) and polystyrene-block-polyhydroxystyrene copolymer (PS-b-PHS) blends where the hydrogen bonding occurred between P2VP and PHS showed hexagonally packed (HEX) cylindrical and body centered cubic (BCC) spherical microdomains. To know the exact location of short block copolymer chains at the interface, we synthesized deuterated polystyrene-block-polyhydroxystyrene copolymer (dPS-b-PHS) and prepared a binary mixture with PS-b-P2VP. We investigate, via small angle X-ray scattering (SAXS) and neutron reflectivity (NR), the exact location of shorter dPS block chain near the interface of the microdomains.

Minimum Description Length Block Finder, a Method to Identify Haplotype Blocks and to Compare the Strength of Block Boundaries

OpenAIRE

Mannila, H.; Koivisto, M.; Perola, M.; Varilo, T.; Hennah, W.; Ekelund, J.; Lukk, M.; Peltonen, L.; Ukkonen, E.

2003-01-01

We describe a new probabilistic method for finding haplotype blocks that is based on the use of the minimum description length (MDL) principle. We give a rigorous definition of the quality of a segmentation of a genomic region into blocks and describe a dynamic programming algorithm for finding the optimal segmentation with respect to this measure. We also describe a method for finding the probability of a block boundary for each pair of adjacent markers: this gives a tool for evaluating the ...

Sensory mediation of memory blocking stressors in the pond snail Lymnaea stagnalis.

Science.gov (United States)

Dalesman, Sarah; Karnik, Vikram; Lukowiak, Ken

2011-08-01

The great pond snail, Lymnaea stagnalis, is commonly used as a model species to study how stress affects the ability to form long-term memory (LTM); however, we still have little information about how the snail senses stressful stimuli. The osphradium is an external sensory organ that demonstrates electrophysiological responses to a variety of external chemical stimuli. We examined the role, if any, played by the osphradium in sensing two environmental stressors, crowding and low environmental calcium, both known to block LTM in intact animals. We severed the osphradial nerve, blocking external sensory input from this organ to the central nervous system, and then exposed the snails to low environmental calcium or crowding stress to assess whether these stressors continued to block LTM formation. When exposed to low environmental calcium, snails with their osphradial nerve severed responded as if they were maintained in our standard calcium environment. That is, they did not respond to low calcium as a stressor blocking LTM; therefore, the osphradium plays a crucial role in mediating how snails respond to this stressor. However, following crowding, LTM formation was blocked in both control groups and snails that had the osphradial nerve severed, indicating that sensory information from the osphradium is not required to sense crowded conditions. Together these data show that two stressors that result in the same behavioural phenotype, blocking LTM formation, do so via two distinct sensory pathways.

Research on Disaster Early Warning and Disaster Relief Integrated Service System Based on Block Data Theory

Science.gov (United States)

Yang, J.; Zhang, H.; Wang, C.; Tang, D.

2018-04-01

With the continuous development of social economy, the interaction between mankind and nature has become increasingly evident. Disastrous global catastrophes have occurred from time to time, causing huge losses to people's lives and property. All governments recognize the importance of the establishment of disaster early warning and release mechanisms, and it is also an urgent issue to improve the comprehensive service level of emergency response and disaster relief. However, disaster early warning and emergency relief information is usually generated by different departments, and the diverse data sources, difficult integration, and limited release speed have always been difficult issues to be solved. Block data is the aggregation of various distributed (point data) and segmentation (data) big data on a specific platform and make them happen continuous polymerization effect, block data theory is a good solution to cross-sectoral, cross-platform Disaster information data sharing and integration problems. This paper attempts to discuss the integrated service mechanism of disaster information aggregation and disaster relief based on block data theory and introduces a location-based integrated service system for disaster early warning and disaster relief.

Development of connecting method for mechanically cut reinforced concrete blocks

International Nuclear Information System (INIS)

Nishiuchi, Tatsuo

2005-01-01

The purpose of the study is to develop a practical method of disposing and recycling in dismantled reinforced concrete structures. We have devised a new method in which mechanically cut reinforced concrete blocks are connected and they are reused as a structural beam. In this method, concrete blocks are connected with several steel bars and the connected surface is wrapped with a fiber sheet. We verified that the load capacity of renewal beams was considerably large as same as that of continuous structural beams on the basis of experimental as well as numerical analysis results. As far as construction cost of reinforced concrete walls are concerned, we demonstrated that the cost of this method is slightly lower than that of the plan to use new and recycle materials. (author)

Simulation of mixed bond graphs and block diagrams on personal computers using TUTSIM

NARCIS (Netherlands)

Beukeboom, J.J.A.J.; van Dixhoorn, J.J.; Meerman, J.W.

1985-01-01

The TUTSIM simulation program for continuous dynamic systems accepts (nonlinear) block diagrams, bond graphs or a free mix of both. The simulation is “hands on” interactive, providing a direct contact with the model. The implementation of the program on existing personal computers (Apple II, IBM PC)

The wild tapered block bootstrap

DEFF Research Database (Denmark)

Hounyo, Ulrich

In this paper, a new resampling procedure, called the wild tapered block bootstrap, is introduced as a means of calculating standard errors of estimators and constructing confidence regions for parameters based on dependent heterogeneous data. The method consists in tapering each overlapping block...... of the series first, the applying the standard wild bootstrap for independent and heteroscedastic distrbuted observations to overlapping tapered blocks in an appropriate way. Its perserves the favorable bias and mean squared error properties of the tapered block bootstrap, which is the state-of-the-art block......-order asymptotic validity of the tapered block bootstrap as well as the wild tapered block bootstrap approximation to the actual distribution of the sample mean is also established when data are assumed to satisfy a near epoch dependent condition. The consistency of the bootstrap variance estimator for the sample...

Initial Mechanical Testing of Superalloy Lattice Block Structures Conducted

Science.gov (United States)

Krause, David L.; Whittenberger, J. Daniel

2002-01-01

, which were not considered in the simplified computer models. The fatigue testing proved the value of redundancies since specimen strength was maintained even after the fracture of one or two ligaments. This ongoing test program is planned to continue through high-temperature testing. Also scheduled for testing are IN 718 lattice block panels with integral face sheets, as well as specimens cast from a higher temperature alloy. The initial testing suggests the value of this technology for large panels under low and moderate pressure loadings and for high-risk, damage-tolerant structures. Potential aeropropulsion uses for lattice blocks include turbine-engine actuated panels, exhaust nozzle flaps, and side panel structures.

A 2d Block Model For Landslide Simulation: An Application To The 1963 Vajont Case

Science.gov (United States)

Tinti, S.; Zaniboni, F.; Manucci, A.; Bortolucci, E.

A 2D block model to study the motion of a sliding mass is presented. The slide is par- titioned into a matrix of blocks the basis of which are quadrilaterals. The blocks move on a specified sliding surface and follow a trajectory that is computed by the model. The forces acting on the blocks are gravity, basal friction, buoyancy in case of under- water motion, and interaction with neighbouring blocks. At any time step, the position of the blocks on the sliding surface is determined in curvilinear (local) co-ordinates by computing the position of the vertices of the quadrilaterals and the position of the block centre of mass. Mathematically, the topology of the system is invariant during the motion, which means that the number of blocks is constant and that each block has always the same neighbours. Physically, this means that blocks are allowed to change form, but not to penetrate into each other, not to coalesce, not to split. The change of form is compensated by the change of height, under the computational assumption that the block volume is constant during motion: consequently lateral expansion or contraction yield respectively height reduction or increment of the blocks. This model is superior to the analogous 1D model where the mass is partitioned into a chain of interacting blocks. 1D models require the a-priori specification of the sliding path, that is of the trajectory of the blocks, which the 2D block model supplies as one of its output. In continuation of previous studies on the catastrophic slide of Vajont that occurred in 1963 in northern Italy and caused more than 2000 victims, the 2D block model has been applied to the Vajont case. The results are compared to the outcome of the 1D model, and more importantly to the observational data concerning the deposit position and morphology. The agreement between simulation and data is found to be quite good.

Clinical Guidelines for Stellate Ganglion Block to Treat Anxiety Associated With Posttraumatic Stress Disorder

Science.gov (United States)

2015-07-01

maintained by the sympathetic branch of the autonomic nervous system as well as the somatic nervous system. Block- ade of the sympathetic nervous...through sternocleidomas- toid, continuing just ventral to the tip of the anterior tubercle of C6, then continuing on until the needle tip has just...know that questioning them is just another way to monitor how they are doing. It is absolutely critical to constantly keep the needle tip in view. If

Designers Block 2002

DEFF Research Database (Denmark)

Dickson, Thomas

2002-01-01

Artiklen indleder med: ved siden aaf Londons etablerede designmesse '100% Design', er der vokset et undergrundsmiljø af designudstillinger op. Det dominerende og mest kendte initiativ er Designers Block, der i år udstillede to steder i byen. Designers Block er et mere uformelt udstillingsforum...

Traveling Rocky Roads: The Consequences of Transcription-Blocking DNA Lesions on RNA Polymerase II

NARCIS (Netherlands)

B. Steurer (Barbara); J.A. Marteijn (Jurgen)

2016-01-01

textabstractThe faithful transcription of eukaryotic genes by RNA polymerase II (RNAP2) is crucial for proper cell function and tissue homeostasis. However, transcription-blocking DNA lesions of both endogenous and environmental origin continuously challenge the progression of elongating RNAP2. The

Quantum teleportation for continuous variables and related quantum information processing

International Nuclear Information System (INIS)

Furusawa, Akira; Takei, Nobuyuki

2007-01-01

Quantum teleportation is one of the most important subjects in quantum information science. This is because quantum teleportation can be regarded as not only quantum information transfer but also a building block for universal quantum information processing. Furthermore, deterministic quantum information processing is very important for efficient processing and it can be realized with continuous-variable quantum information processing. In this review, quantum teleportation for continuous variables and related quantum information processing are reviewed from these points of view

Integrative assessment of kick boxers’ brain blood circulation and bio-electrical activity in conditions of correction technologies’ application

Directory of Open Access Journals (Sweden)

Y.N. Romanov

2016-06-01

Full Text Available Purpose: to scientifically substantiate the role of para-vertebral impacts on blood circulation and bio-electrical activity of kick boxers’ cortex. Material: in the research participated kick boxers (main group, n=62 and university students (control group, n=25 of 18-23 years’ age. Assessment of para-vertebral impacts with device Armos and classic massage was fulfilled with the help of the following methodic: trans-cranial dopplerography of head main arteries and cortex EEG of the tested. Results: it was found that with the help of para-vertebral impacts by device Armos linear velocity of cerebral blood flow reduces to normal limits and in- and inter-hemispheres’ interaction strength increases. Conclusions: para-vertebral impacts by device Armos activate integrative processes and inter-hemispheres’ interactions of different cortex areas of kick boxers. It can witness about better formation of functional systems, ensuring sports efficiency.

Functional materials derived from block copolymer self-assembly

DEFF Research Database (Denmark)

Li, Tao

deposition methods, namely nanocasting and atomic layer deposition (ALD) will be applied to fabricate compact, inter-connected, and continuous metal oxide films. In this way, the structure integrity will be preserved after template removal during the annealing procedure. Another objective of this project......-casting, the block copolymer self-organizes into monolayer packed sphere pattern, without any surface treatment of the substrate and annealing process. Arrays of nano-pillars and nanowells of various materials are fabricated in dry etch processes over wafer scale without defects. We also show an in situ Al2O3 hard...

Arthroscopic medial meniscus trimming or repair under nerve blocks: Which nerves should be blocked?

Science.gov (United States)

Taha, AM; Abd-Elmaksoud, AM

2016-01-01

Background: This study aimed to determine the role of the sciatic and obturator nerve blocks (in addition to femoral block) in providing painless arthroscopic medial meniscus trimming/repair. Materials and Methods: One hundred and twenty patients with medial meniscus tear, who had been scheduled to knee arthroscopy, were planned to be included in this controlled prospective double-blind study. The patients were randomly allocated into three equal groups; FSO, FS, and FO. The femoral, sciatic, and obturator nerves were blocked in FSO groups. The femoral and sciatic nerves were blocked in FS group, while the femoral and obturator nerves were blocked in FO group. Intraoperative pain and its causative surgical maneuver were recorded. Results: All the patients (n = 7, 100%) in FO group had intraoperative pain. The research was terminated in this group but completed in FS and FSO groups (40 patients each). During valgus positioning of the knee for surgical management of the medial meniscus tear, the patients in FS group experienced pain more frequently than those in FSO group (P = 0.005). Conclusion: Adding a sciatic nerve block to the femoral nerve block is important for painless knee arthroscopy. Further adding of an obturator nerve block may be needed when a valgus knee position is required to manage the medial meniscus tear. PMID:27375382

ON DISCRETE STRUCTURE OF GEOLOGIC MEDIUM AND CONTINUAL APPROACH TO MODELING ITS MOVEMENTS

OpenAIRE

Sh. A. Mukhamediev

2016-01-01

This paper discusses the structure of a geologic medium represented by accessible lithified rocks and provides an overview of methods used to describe its movements. Two basic opinions are considered in the framework of the discussion: (1) an initially homogeneous and continuous geologic medium acquires the structure composed of blocks in the process of the geologic medium’s deformation/destruction/degradation, and (2) a geologic medium is composed of blocks (and often has hierarchic, active,...

Optimizing Music Learning: Exploring How Blocked and Interleaved Practice Schedules Affect Advanced Performance.

Science.gov (United States)

Carter, Christine E; Grahn, Jessica A

2016-01-01

Repetition is the most commonly used practice strategy by musicians. Although blocks of repetition continue to be suggested in the pedagogical literature, work in the field of cognitive psychology suggests that repeated events receive less processing, thereby reducing the potential for long-term learning. Motor skill learning and sport psychology research offer an alternative. Instead of using a blocked practice schedule, with practice completed on one task before moving on to the next task, an interleaved schedule can be used, in which practice is frequently alternated between tasks. This frequent alternation involves more effortful processing, resulting in increased long-term learning. The finding that practicing in an interleaved schedule leads to better retention than practicing in a blocked schedule has been labeled the "contextual interference effect." While the effect has been observed across a wide variety of fields, few studies have researched this phenomenon in a music-learning context, despite the broad potential for application to music practice. This study compared the effects of blocked and interleaved practice schedules on advanced clarinet performance in an ecologically valid context. Ten clarinetists were given one concerto exposition and one technical excerpt to practice in a blocked schedule (12 min per piece) and a second concerto exposition and technical excerpt to practice in an interleaved schedule (3 min per piece, alternating until a total of 12 min of practice were completed on each piece). Participants sight-read the four pieces prior to practice and performed them at the end of practice and again one day later. The sight-reading and two performance run-throughs of each piece were recorded and given to three professional clarinetists to rate using a percentage scale. Overall, whenever there was a ratings difference between the conditions, pieces practiced in the interleaved schedule were rated better than those in the blocked schedule

Optimizing Music Learning: Exploring How Blocked and Interleaved Practice Schedules Affect Advanced Performance

Science.gov (United States)

Carter, Christine E.; Grahn, Jessica A.

2016-01-01

Repetition is the most commonly used practice strategy by musicians. Although blocks of repetition continue to be suggested in the pedagogical literature, work in the field of cognitive psychology suggests that repeated events receive less processing, thereby reducing the potential for long-term learning. Motor skill learning and sport psychology research offer an alternative. Instead of using a blocked practice schedule, with practice completed on one task before moving on to the next task, an interleaved schedule can be used, in which practice is frequently alternated between tasks. This frequent alternation involves more effortful processing, resulting in increased long-term learning. The finding that practicing in an interleaved schedule leads to better retention than practicing in a blocked schedule has been labeled the “contextual interference effect.” While the effect has been observed across a wide variety of fields, few studies have researched this phenomenon in a music-learning context, despite the broad potential for application to music practice. This study compared the effects of blocked and interleaved practice schedules on advanced clarinet performance in an ecologically valid context. Ten clarinetists were given one concerto exposition and one technical excerpt to practice in a blocked schedule (12 min per piece) and a second concerto exposition and technical excerpt to practice in an interleaved schedule (3 min per piece, alternating until a total of 12 min of practice were completed on each piece). Participants sight-read the four pieces prior to practice and performed them at the end of practice and again one day later. The sight-reading and two performance run-throughs of each piece were recorded and given to three professional clarinetists to rate using a percentage scale. Overall, whenever there was a ratings difference between the conditions, pieces practiced in the interleaved schedule were rated better than those in the blocked schedule

Optimizing music learning: Exploring how blocked and interleaved practice schedules affect advanced performance

Directory of Open Access Journals (Sweden)

Christine E Carter

2016-08-01

Full Text Available Repetition is the most commonly used practice strategy by musicians. Although blocks of repetition continue to be suggested in the pedagogical literature, work in the field of cognitive psychology suggests that repeated events receive less processing, thereby reducing the potential for long-term learning. Motor skill learning and sport psychology research offer an alternative. Instead of using a blocked practice schedule, with practice completed on one task before moving on to the next task, an interleaved schedule can be used, in which practice is frequently alternated between tasks. This frequent alternation involves more effortful processing, resulting in increased long-term learning. The finding that practicing in an interleaved schedule leads to better retention than practicing in a blocked schedule has been labeled the contextual interference effect. While the effect has been observed across a wide variety of fields, few studies have researched this phenomenon in a music-learning context, despite the broad potential for application to music practice. This study compared the effects of blocked and interleaved practice schedules on advanced clarinet performance in an ecologically valid context. Ten clarinetists were given one concerto exposition and one technical excerpt to practice in a blocked schedule (twelve minutes per piece and a second concerto exposition and technical excerpt to practice in an interleaved schedule (three minutes per piece, alternating until a total of twelve minutes of practice were completed on each piece. Participants sight-read the four pieces prior to practice and performed them at the end of practice and again one day later. The sight-reading and two performance run-throughs of each piece were recorded and given to three professional clarinetists to rate using a percentage scale. Overall, whenever there was a ratings difference between the conditions, pieces practiced in the interleaved schedule were rated

Coastal protection using topological interlocking blocks

Science.gov (United States)

Pasternak, Elena; Dyskin, Arcady; Pattiaratchi, Charitha; Pelinovsky, Efim

2013-04-01

The coastal protection systems mainly rely on the self-weight of armour blocks to ensure its stability. We propose a system of interlocking armour blocks, which form plate-shape assemblies. The shape and the position of the blocks are chosen in such a way as to impose kinematic constraints that prevent the blocks from being removed from the assembly. The topological interlocking shapes include simple convex blocks such as platonic solids, the most practical being tetrahedra, cubes and octahedra. Another class of topological interlocking blocks is so-called osteomorphic blocks, which form plate-like assemblies tolerant to random block removal (almost 25% of blocks need to be removed for the assembly to loose integrity). Both classes require peripheral constraint, which can be provided either by the weight of the blocks or post-tensioned internal cables. The interlocking assemblies provide increased stability because lifting one block involves lifting (and bending) the whole assembly. We model the effect of interlocking by introducing an equivalent additional self-weight of the armour blocks. This additional self-weight is proportional to the critical pressure needed to cause bending of the interlocking assembly when it loses stability. Using beam approximation we find an equivalent stability coefficient for interlocking. It is found to be greater than the stability coefficient of a structure with similar blocks without interlocking. In the case when the peripheral constraint is provided by the weight of the blocks and for the slope angle of 45o, the effective stability coefficient for a structure of 100 blocks is 33% higher than the one for a similar structure without interlocking. Further increase in the stability coefficient can be reached by a specially constructed peripheral constraint system, for instance by using post-tension cables.

Patients' and procedural characteristics of AV-block during slow pathway modulation for AVNRT-single center 10year experience.

Science.gov (United States)

Wasmer, Kristina; Dechering, Dirk G; Köbe, Julia; Leitz, Patrick; Frommeyer, Gerrit; Lange, Phillip S; Kochhäuser, Simon; Reinke, Florian; Pott, Christian; Mönnig, Gerold; Breithardt, Günter; Eckardt, Lars

2017-10-01

Permanent AV-block is a recognized and feared complication of slow pathway modulation for AVNRT. We aimed to assess incidence of transient and permanent AV-block as well as consequences of transient AV-block in a large contemporary AVNRT ablation cohort. We searched our single center prospective ablation database for occurrence of transient and permanent AV-block during slow pathway modulation between January 2004 and October 2015. We analyzed patients' and procedural characteristics as well as outcome of patients in whom transient or permanent AV-block occurred. Of 9170 patients who underwent a catheter ablation at our institution between January 2004 and October 2015, 2101 patients (64% women, mean age 50±18years) underwent slow pathway modulation. In three patients, permanent AV-block occurred during RF application. Additional two patients had transient AV-block that recovered (after a few minutes and 25min), but recurred within two days of the procedure. All five patients underwent dual chamber pacemaker implantation (0.2%). Transient AV-block related to RF delivery occurred in 44 patients (2%). Transient mechanical AV-block occurred in additional 17 patients (0.8%). In 12 patients, ablation was continued despite transient AV-block. One of these patients developed permanent AV-block. Permanent AV-block following slow pathway modulation is a rare event, occurring in 0.2% of patients in a large contemporary single center cohort. Transient AV-block is more frequent (2%). Copyright © 2017 Elsevier B.V. All rights reserved.

Nalbuphine as an adjuvant to 0.25% levobupivacaine in ultrasound-guided supraclavicular block provided prolonged sensory block and similar motor block durations (RCT).

Science.gov (United States)

Abdelhamid, Bassant Mohamed; Omar, Heba

2018-05-28

Prolonged postoperative analgesia with early motor recovery for early rehabilitation is a challenge in regional block. The purpose of this study is to evaluate the effect of adding 20 mg nalbuphine to 25 ml of 0.25% levobupivacaine in supraclavicular brachial plexus block. One hundred thirty-five (135) patients scheduled for hand and forearm surgeries with supraclavicular block were randomly allocated into three equal groups. Group L received 25 ml of 0.5% levobupivacaine + 1 ml normal saline; group H received 25 ml of 0.25% levobupivacaine + 1 ml normal saline; and group N received 25 ml of 0.25% levobupivacaine + 1 ml (20 mg) nalbuphine. Onset time and duration of sensory and motor block, and time to first analgesic dose were recorded. Sensory block onset was comparable between the three groups. Motor block onset in group L and group N was comparable (13.16 ± 3.07 and 13.84 ± 3.05 min, respectively) and was shorter than that in group H (15.71 ± 2 0.91 min). Sensory block duration in group L and group N was comparable (522.22 ± 69.57 and 533.78 ± 66.03 min, respectively) and was longer than that in group H (342.67 ± 92.80 min). Motor block duration in group N and group H was comparable (272.00 ± 59.45 and 249.78 ± 66.01 min, respectively) and was shorter than that in group L (334.67 ± 57.90 min). Time to first analgesic dose was significantly longer in group N (649.78 ± 114.76 min) than that of group L and group H (575.56 ± 96.85 and 375.56 ± 84.49 min, respectively) and longer in group L when compared to group H. Adding 20 mg nalbuphine to 25 ml of 0.25% levobupivacaine in supraclavicular block provided prolonged duration of sensory block with similar duration of motor block.

Continuous recording and interobserver agreement algorithms reported in the Journal of Applied Behavior Analysis (1995-2005).

Science.gov (United States)

Mudford, Oliver C; Taylor, Sarah Ann; Martin, Neil T

2009-01-01

We reviewed all research articles in 10 recent volumes of the Journal of Applied Behavior Analysis (JABA): Vol. 28(3), 1995, through Vol. 38(2), 2005. Continuous recording was used in the majority (55%) of the 168 articles reporting data on free-operant human behaviors. Three methods for reporting interobserver agreement (exact agreement, block-by-block agreement, and time-window analysis) were employed in more than 10 of the articles that reported continuous recording. Having identified these currently popular agreement computation algorithms, we explain them to assist researchers, software writers, and other consumers of JABA articles.

CT of osteomyelitis of the spine

International Nuclear Information System (INIS)

Golimbu, C.; Firooznia, H.; Rafii, M.

1984-01-01

Computed tomography (CT) scans were performed in 17 adults with osteomyelitis of the spine. The dominant features were paravertebral soft-tissue swelling, abscess formation, and bone erosion. In two patients there were no findings indicative of osteomyelitis on conventional radiographs, but CT revealed paravertebral abscesses and bone lysis, helping to establish the diagnosis of osteomyelitis, chiefly because of its ability to detect early erosion of spongy vertabral bone, disk involvement, paravertebral soft-tissue swelling or abscess, and extension of the pathology into the spinal canal. Furthermore, CT facilitated closed-needle biopsy, helping to establish the pathologic diagnosis

Delayed appearance of hypaesthesia and paralysis after femoral nerve block

OpenAIRE

Stefan Landgraeber; Thomas Albrecht; Ulrich Reischuck; Marius von Knoch

2012-01-01

We report on a female patient who underwent an arthroscopy of the right knee and was given a continuous femoral nerve block catheter. The postoperative course was initially unremarkable, but when postoperative mobilisation was commenced, 18 hours after removal of the catheter, the patient noticed paralysis and hypaesthesia. Examination confirmed the diagnosis of femoral nerve dysfunction. Colour duplex sonography of the femoral artery and computed tomography of the lumbar spine and pelvis yie...

Approximate design theory for a simple block design with random block effects

OpenAIRE

Christof, Karin

1985-01-01

Approximate design theory for a simple block design with random block effects / K. Christof ; F. Pukelsheim. - In: Linear statistical inference / ed. by T. Calinski ... - Berlin u. a. : Springer, 1985. - S. 20-28. - (Lecture notes in statistics ; 35)

Membrane InP saturable absorbers on silicon as building blocks for transparent optical networks

NARCIS (Netherlands)

Raz, O.; Tassaert, M.; Roelkens, G.C.; Dorren, H.J.S.

2013-01-01

As silicon photonics continues to gain research and industrial relevance, some of the building blocks in this technology such as modulators and switches still suffer from limitation when it comes to insertion losses and/or extinction ratio. In the past two years we have been investigating a

Solving block linear systems with low-rank off-diagonal blocks is easily parallelizable

Energy Technology Data Exchange (ETDEWEB)

Menkov, V. [Indiana Univ., Bloomington, IN (United States)

1996-12-31

An easily and efficiently parallelizable direct method is given for solving a block linear system Bx = y, where B = D + Q is the sum of a non-singular block diagonal matrix D and a matrix Q with low-rank blocks. This implicitly defines a new preconditioning method with an operation count close to the cost of calculating a matrix-vector product Qw for some w, plus at most twice the cost of calculating Qw for some w. When implemented on a parallel machine the processor utilization can be as good as that of those operations. Order estimates are given for the general case, and an implementation is compared to block SSOR preconditioning.

Rolling block mazes are PSPACE-complete

NARCIS (Netherlands)

Buchin, K.; Buchin, M.

2012-01-01

In a rolling block maze, one or more blocks lie on a rectangular board with square cells. In most mazes, the blocks have size k × m × n where k, m, n are integers that determine the size of the block in terms of units of the size of the board cells. The task of a rolling block maze is to roll a

Solving the Telegraph and Oscillatory Differential Equations by a Block Hybrid Trigonometrically Fitted Algorithm

Directory of Open Access Journals (Sweden)

F. F. Ngwane

2015-01-01

Full Text Available We propose a block hybrid trigonometrically fitted (BHT method, whose coefficients are functions of the frequency and the step-size for directly solving general second-order initial value problems (IVPs, including systems arising from the semidiscretization of hyperbolic Partial Differential Equations (PDEs, such as the Telegraph equation. The BHT is formulated from eight discrete hybrid formulas which are provided by a continuous two-step hybrid trigonometrically fitted method with two off-grid points. The BHT is implemented in a block-by-block fashion; in this way, the method does not suffer from the disadvantages of requiring starting values and predictors which are inherent in predictor-corrector methods. The stability property of the BHT is discussed and the performance of the method is demonstrated on some numerical examples to show accuracy and efficiency advantages.

A PMT-Block test bench

International Nuclear Information System (INIS)

Adragna, P.; Antonaki, A.

2006-01-01

The front-end electronics of the ATLAS hadronic calorimeter (Tile Cal) is housed in a unit, called PMT-Block. The PMT-Block is a compact instrument comprising a light mixer, a PMT together with its divider and a 3-in-1 card, which provides shaping, amplification and integration for the signals. This instrument needs to be qualified before being assembled on the detector. A PMT-Block test bench has been developed for this purpose. This test bench is a system which allows fast, albeit accurate enough, measurements of the main properties of a complete PMT-Block. The system, both hardware and software, and the protocol used for the PMT-Blocks characterization are described in detail in this report. The results obtained in the test of about 10 000 PMT-Blocks needed for the instrumentation of the ATLAS (LHC-CERN) hadronic Tile Calorimeter are also reported

A PMT-Block test bench

Energy Technology Data Exchange (ETDEWEB)

Adragna, P [Dipartimento di Fisica ' E.Fermi' , Universita di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Largo B. Pontecorvo 3, Pisa 56127 (Italy); Universita degli studi di Siena, via Roma 56, 53100 Siena (Italy); Antonaki, A [Institute of Accelerating Systems and Applications, P.O. Box 17214, Athens 10024 (Greece); National Capodistrian University of Athens, 30 Panepistimiou st., Athens 10679 (Greece)] (and others)

2006-08-01

The front-end electronics of the ATLAS hadronic calorimeter (Tile Cal) is housed in a unit, called PMT-Block. The PMT-Block is a compact instrument comprising a light mixer, a PMT together with its divider and a 3-in-1 card, which provides shaping, amplification and integration for the signals. This instrument needs to be qualified before being assembled on the detector. A PMT-Block test bench has been developed for this purpose. This test bench is a system which allows fast, albeit accurate enough, measurements of the main properties of a complete PMT-Block. The system, both hardware and software, and the protocol used for the PMT-Blocks characterization are described in detail in this report. The results obtained in the test of about 10 000 PMT-Blocks needed for the instrumentation of the ATLAS (LHC-CERN) hadronic Tile Calorimeter are also reported.

Masquerading bundle branch block as a presenting manifestation of complete atrioventricular block that caused syncope.

Science.gov (United States)

Jiao, Zhenyu; Tian, Ying; Yang, Xinchun; Liu, Xingpeng

2017-10-01

A 59-year-old male patient was admitted with the main complaints of stuffiness and shortness of breath. An ECG from precordial leads on admission showed masquerading bundle branch block. Syncope frequently occurred after admission. During syncope episodes, ECG telemetry showed that the syncope was caused by intermittent complete atrioventricular block, with the longest RR interval lasting for 4.36 s. At the gap of syncope, ECG showed complete right bundle branch block accompanied by alternation of left anterior fascicular block and left posterior fascicular block. The patient was implanted with a dual-chamber permanent pacemaker. Follow-up of 9 months showed no reoccurrence of syncope.

Backfilling of deposition tunnels, block alternative

International Nuclear Information System (INIS)

Keto, P.; Roennqvist, P.-E.

2007-03-01

This report presents a preliminary process description of backfilling the deposition tunnels with pre-compacted blocks consisting of a mixture of bentonite and ballast (30:70). The process was modified for the Finnish KBS-3V type repository assuming that the amount of spent fuel canisters disposed of yearly is 40. Backfilling blocks (400 x 300 x 300 mm) are prepared in a block production plant with a hydraulic press with an estimated production capacity of 840 blocks per day. Some of the blocks are modified further to fit the profile of the tunnel roof. Prior to the installation of the blocks, the deposition tunnel floor is levelled with a mixture of bentonite and ballast (15:85). The blocks are placed in the tunnel with a modified reach truck. Centrifugal pellet throwing equipment is used to fill the gap between the blocks and the rock surface with bentonite pellets. Based on a preliminary assessment, the average dry density achieved with block backfill is sufficient to fulfil the criteria set for the backfill in order to ensure long-term safety and radiation protection. However, there are uncertainties concerning saturation, homogenisation, erosion, piping and self-healing of the block backfill that need to be studied further with laboratory and field tests. In addition, development efforts and testing concerning block manufacturing and installation are required to verify the technical feasibility of the concept. (orig.)

Emplacement of small and large buffer blocks

International Nuclear Information System (INIS)

Saari, H.; Nikula, M.; Suikki, M.

2010-05-01

The report describes emplacement of a buffer structure encircling a spent fuel canister to be deposited in a vertical hole. The report deals with installability of various size blocks and with an emplacement gear, as well as evaluates the achieved quality of emplacement and the time needed for installing the buffer. Two block assembly of unequal size were chosen for examination. A first option involved small blocks, the use of which resulted in a buffer structure consisting of small sector blocks 200 mm in height. A second option involved large blocks, resulting in a buffer structure which consists of eight blocks. In these tests, the material chosen for both block options was concrete instead of bentonite. The emplacement test was a three-phase process. A first phase included stacking a two meter high buffer structure with small blocks for ensuring the operation of test equipment and blocks. A second phase included installing buffer structures with both block options to a height matching that of a canister-encircling cylindrical component. A third phase included testing also the installability of blocks to be placed above the canister by using small blocks. In emplacement tests, special attention was paid to the installability of blocks as well as to the time required for emplacement. Lifters for both blocks worked well. Due to the mass to be lifted, the lifter for large blocks had a more heavy-duty frame structure (and other lifting gear). The employed lifters were suspended in the tests on a single steel wire rope. Stacking was managed with both block sizes at adequate precision and stacked-up towers were steady. The stacking of large blocks was considerably faster. Therefore it is probably that the overall handling of the large blocks will be more convenient at a final disposal site. From the standpoint of reliability in lifting, the small blocks were safer to install above the canister. In large blocks, there are strict shape-related requirements which are

Three new karst-dwelling Cnemaspis Strauch, 1887 (Squamata; Gekkoniade from Peninsular Thailand and the phylogenetic placement of C. punctatonuchalis and C. vandeventeri

Directory of Open Access Journals (Sweden)

Perry Lee Wood Jr

2017-01-01

Full Text Available Three new species of Rock Geckos Cnemaspis lineogularis sp. nov., C. phangngaensis sp. nov., and C. thachanaensis sp. nov. of the chanthaburiensis and siamensis groups are described from the Thai portion of the Thai-Malay Peninsula. These new species are distinguished from all other species in their two respective groups based on a unique combination of morphological characteristics, which is further supported by mitochondrial DNA (mtDNA from the NADH dehydrogenase subunit 2 gene (ND2. Cnemaspis lineogularis sp. nov. is differentiated from all other species in the chanthaburiensis group by having a smaller maximum SVL 38 mm, 13 paravertebral tubercles, enlarged femoral scales, no caudal bands, and a 19.5–23.0% pairwise sequence divergence (ND2. Cnemaspis phangngaensis sp. nov. is differentiated from all other species in the siamensis group by having the unique combination of 10 infralabial scales, four continuous pore-bearing precloacal scales, paravertebral tubercles linearly arranged, lacking tubercles on the lower flanks, having ventrolateral caudal tubercles anteriorly present, caudal tubercles restricted to a single paraveterbral row on each side, a single median row of keeled subcaudals, and a 8.8–25.2% pairwise sequence divergence (ND2. Cnemaspis thachanaensis sp. nov. is distinguished from all other species in the siamensis group by having 10 or 11 supralabial scales 9–11 infralabial scales, paravertebral tubercles linearly arranged, ventrolateral caudal tubercles anteriorly, caudal tubercles restricted to a single paravertebral row on each side, a single median row of keeled subcaudal scales, lacking a single enlarged subcaudal scale row, lacking postcloaclal tubercles in males, the presence of an enlarged submetatarsal scale at the base if the 1st toe, and a 13.4–28.8% pairwise sequence divergence (ND2. The new phylogenetic analyses place C. punctatonuchalis and C. vandeventeri in the siamensis group with C

Effects of concentrate replacement by feed blocks on ruminal fermentation and microbial growth in goats and single-flow continuous-culture fermenters.

Science.gov (United States)

Molina-Alcaide, E; Pascual, M R; Cantalapiedra-Hijar, G; Morales-García, E Y; Martín-García, A I

2009-04-01

The effect of replacing concentrate with 2 different feed blocks (FB) on ruminal fermentation and microbial growth was evaluated in goats and in single-flow continuous-culture fermenters. Diets consisted of alfalfa hay plus concentrate and alfalfa hay plus concentrate with 1 of the 2 studied FB. Three trials were carried out with 6 rumen-fistulated Granadina goats and 3 incubation runs in 6 single-flow continuous-culture fermenters. Experimental treatments were assigned randomly within each run, with 2 repetitions for each diet. At the end of each in vivo trial, the rumen contents were obtained for inoculating the fermenters. For each incubation run, the fermenters were inoculated with ruminal fluid from goats fed the same diet supplied to the corresponding fermenter flask. The average pH values, total and individual VFA, and NH(3)-N concentrations, and acetate:propionate ratios in the rumen of goats were not affected (P >or= 0.10) by diet, whereas the microbial N flow (MNF) and efficiency were affected (P fermenters, the diet affected pH (Por= 0.05), and total (P=0.02), NH(3) (P=0.005), and non-NH(3) (P=0.02) N flows, whereas the efficiency of VFA production was not affected (P=0.75). The effect of diet on MNF and efficiency depended on the bacterial pellet used as a reference. An effect (Pfermenter contents and effluent were similar (P=0.05). Differences (Pfermentation variables and bacterial pellet compositions were found. Partial replacement of the concentrate with FB did not greatly compromise carbohydrate fermentation in unproductive goats. However, this was not the case for MNF and efficiency. Differences between the results obtained in vivo and in vitro indicate a need to identify conditions in fermenters that allow better simulation of fermentation, microbial growth, and bacterial pellet composition in vivo. Reduced feeding cost could be achieved with the inclusion of FB in the diets of unproductive goats without altering rumen fermentation.

Evidence of structurally continuous collagen fibrils in tendon

DEFF Research Database (Denmark)

Svensson, Rene B; Herchenhan, Andreas; Starborg, Tobias

2017-01-01

favor continuity. This study initially set out to trace the full length of individual fibrils in adult human tendons, using serial block face-scanning electron microscopy. But even with this advanced technique the required length could not be covered. Instead a statistical approach was used on a large...... volume of fibrils in shorter image stacks. Only a single end was observed after tracking 67.5 mm of combined fibril lengths, in support of fibril continuity. To shed more light on this observation, the full length of a short tendon (mouse stapedius, 125 μm) was investigated and continuity of individual...... fibrils was confirmed. In light of these results, possible mechanisms that could reconcile the opposing findings on fibril continuity are discussed. STATEMENT OF SIGNIFICANCE: Connective tissues hold all parts of the body together and are mostly constructed from thin threads of the protein collagen...

Pyomyositis of the iliacus muscle and pyogenic sacroiliitis after sacroiliac joint block -A case report-.

Science.gov (United States)

Lee, Mi Hyeon; Byon, Hyo-Jin; Jung, Hyun Jun; Cha, Young-Deog; Lee, Doo Ik

2013-05-01

Sacroiliac joint block can be performed for the diagnosis and treatment of sacroiliac joint dysfunction. Although sacroiliac joint block is a common procedure, complications have not been reported in detail. We report a case of iliacus pyomyositis and sacroiliac joint infection following a sacroiliac joint block. A 70-year-old female patient received sacroiliac joint blocks to relieve pelvic pain. The patient was admitted to the emergency room two days after the final sacroiliac joint block (SIJB) with the chief complaints of left pelvic pain corresponding to a visual analogue scale (VAS) score of 9 and fever. A pelvic MRI indicated a diagnosis of myositis. After 1 month of continuous antibiotic therapy, the patient's erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level remained elevated. A (67)Ga SPECT/CT was done. Abnormal uptake was seen at the left sacroiliac joint (SIJ), and septic sacroiliitis was suspected. The CRP normalized to 0.29 mg/dl and the ESR decreased to 60 mm/hr, and the patient had no fever after 57 days of antibiotic therapy. She was directed for follow up at an outpatient clinic.

Ionization of amphiphilic acidic block copolymers.

Science.gov (United States)

Colombani, Olivier; Lejeune, Elise; Charbonneau, Céline; Chassenieux, Christophe; Nicolai, Taco

2012-06-28

The ionization behavior of an amphiphilic diblock copolymer poly(n-butyl acrylate(50%)-stat-acrylic acid(50%))(100)-block-poly(acrylic acid)(100) (P(nBA(50%)-stat-AA(50%))(100)-b-PAA(100), DH50) and of its equivalent triblock copolymer P(nBA(50%)-stat-AA(50%))(100)-b-PAA(200)-b-P(nBA(50%)-stat-AA(50%))(100) (TH50) were studied by potentiometric titration either in pure water or in 0.5 M NaCl. These polymers consist of a hydrophilic acidic block (PAA) connected to a hydrophobic block, P(nBA(50%)-stat-AA(50%))(100), whose hydrophobic character has been mitigated by copolymerization with hydrophilic units. We show that all AA units, even those in the hydrophobic block could be ionized. However, the AA units within the hydrophobic block were less acidic than those in the hydrophilic block, resulting in the preferential ionization of the latter block. The preferential ionization of PAA over that of P(nBA(50%)-stat-AA(50%))(100) was stronger at higher ionic strength. Remarkably, the covalent bonds between the PAA and P(nBA(50%)-stat-AA(50%))(100) blocks in the diblock or the triblock did not affect the ionization of each block, although the self-association of the block copolymers into spherical aggregates modified the environment of the PAA blocks compared to when PAA was molecularly dispersed.

Integral-fuel blocks

International Nuclear Information System (INIS)

Cunningham, C.; Simpkin, S.D.

1975-01-01

A prismatic moderator block is described which has fuel-containing channels and coolant channels disposed parallel to each other and to edge faces of the block. The coolant channels are arranged in rows on an equilateral triangular lattice pattern and the fuel-containing channels are disposed in a regular lattice pattern with one fuel-containing channel between and equidistant from each of the coolant channels in each group of three mutually adjacent coolant channels. The edge faces of the block are parallel to the rows of coolant channels and the channels nearest to each edge face are disposed in two rows parallel thereto, with one of the rows containing only coolant channels and the other row containing only fuel-containing channels. (Official Gazette)

Powered Explicit Guidance Modifications and Enhancements for Space Launch System Block-1 and Block-1B Vehicles

Science.gov (United States)

Von der Porten, Paul; Ahmad, Naeem; Hawkins, Matt; Fill, Thomas

2018-01-01

NASA is currently building the Space Launch System (SLS) Block-1 launch vehicle for the Exploration Mission 1 (EM-1) test flight. NASA is also currently designing the next evolution of SLS, the Block-1B. The Block-1 and Block-1B vehicles will use the Powered Explicit Guidance (PEG) algorithm (of Space Shuttle heritage) for closed loop guidance. To accommodate vehicle capabilities and design for future evolutions of SLS, modifications were made to PEG for Block-1 to handle multi-phase burns, provide PEG updated propulsion information, and react to a core stage engine out. In addition, due to the relatively low thrust-to-weight ratio of the Exploration Upper Stage (EUS) and EUS carrying out Lunar Vicinity and Earth Escape missions, certain enhancements to the Block-1 PEG algorithm are needed to perform Block-1B missions to account for long burn arcs and target translunar and hyperbolic orbits. This paper describes the design and implementation of modifications to the Block-1 PEG algorithm as compared to Space Shuttle. Furthermore, this paper illustrates challenges posed by the Block-1B vehicle and the required PEG enhancements. These improvements make PEG capable for use on the SLS Block-1B vehicle as part of the Guidance, Navigation, and Control (GN&C) System.

Continuous Recording and Interobserver Agreement Algorithms Reported in The Journal of Applied Behavior Analysis (1995–2005)

Science.gov (United States)

Mudford, Oliver C; Taylor, Sarah Ann; Martin, Neil T

2009-01-01

We reviewed all research articles in 10 recent volumes of the Journal of Applied Behavior Analysis (JABA): Vol. 28(3), 1995, through Vol. 38(2), 2005. Continuous recording was used in the majority (55%) of the 168 articles reporting data on free-operant human behaviors. Three methods for reporting interobserver agreement (exact agreement, block-by-block agreement, and time-window analysis) were employed in more than 10 of the articles that reported continuous recording. Having identified these currently popular agreement computation algorithms, we explain them to assist researchers, software writers, and other consumers of JABA articles. PMID:19721737

Building Curriculum during Block Play

Science.gov (United States)

Andrews, Nicole

2015-01-01

Blocks are not just for play! In this article, Nicole Andrews describes observing the interactions of three young boys enthusiastically engaged in the kindergarten block center of their classroom, using blocks in a building project that displayed their ability to use critical thinking skills, physics exploration, and the development of language…

Region 9 Census Block 2010

Science.gov (United States)

Geography:The TIGER Line Files are feature classes and related database files (.) that are an extract of selected geographic and cartographic information from the U.S. Census Bureau's Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) Database (MTDB). The MTDB represents a seamless national file with no overlaps or gaps between parts, however, each TIGER Line File is designed to stand alone as an independent data set, or they can be combined to cover the entire nation. Census Blocks are statistical areas bounded on all sides by visible features, such as streets, roads, streams, and railroad tracks, and/or by non visible boundaries such as city, town, township, and county limits, and short line-of-sight extensions of streets and roads. Census blocks are relatively small in area; for example, a block in a city bounded by streets. However, census blocks in remote areas are often large and irregular and may even be many square miles in area. A common misunderstanding is that data users think census blocks are used geographically to build all other census geographic areas, rather all other census geographic areas are updated and then used as the primary constraints, along with roads and water features, to delineate the tabulation blocks. As a result, all 2010 Census blocks nest within every other 2010 Census geographic area, so that Census Bureau statistical data can be tabulated at the block level and aggregated up t

Various semiclassical limits of torus conformal blocks

Energy Technology Data Exchange (ETDEWEB)

Alkalaev, Konstantin [I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky ave. 53, Moscow, 119991 (Russian Federation); Department of General and Applied Physics, Moscow Institute of Physics and Technology,Institutskiy per. 7, Dolgoprudnyi, Moscow region, 141700 (Russian Federation); Geiko, Roman [Mathematics Department, National Research University Higher School of Economics,Usacheva str. 6, Moscow, 119048 (Russian Federation); Rappoport, Vladimir [I.E. Tamm Department of Theoretical Physics, P.N. Lebedev Physical Institute,Leninsky ave. 53, Moscow, 119991 (Russian Federation); Department of Quantum Physics, Institute for Information Transmission Problems,Bolshoy Karetny per. 19, Moscow, 127994 (Russian Federation)

2017-04-12

We study four types of one-point torus blocks arising in the large central charge regime. There are the global block, the light block, the heavy-light block, and the linearized classical block, according to different regimes of conformal dimensions. It is shown that the blocks are not independent being connected to each other by various links. We find that the global, light, and heavy-light blocks correspond to three different contractions of the Virasoro algebra. Also, we formulate the c-recursive representation of the one-point torus blocks which is relevant in the semiclassical approximation.

Common blocks for ASQS(12

Directory of Open Access Journals (Sweden)

Lorenzo Milazzo

1997-05-01

Full Text Available An ASQS(v is a particular Steiner system featuring a set of v vertices and two separate families of blocks, B and G, whose elements have a respective cardinality of 4 and 6. It has the property that any three vertices of X belong either to a B-block or to a G-block. The parameter cb is the number of common blocks in two separate ASQSs, both defined on the same set of vertices X . In this paper it is shown that cb ≤ 29 for any pair of ASQSs(12.

Pectoral nerve block (Pecs block) with sedation for breast conserving surgery without general anesthesia.

Science.gov (United States)

Moon, Eun-Jin; Kim, Seung-Beom; Chung, Jun-Young; Song, Jeong-Yoon; Yi, Jae-Woo

2017-09-01

Most regional anesthesia in breast surgeries is performed as postoperative pain management under general anesthesia, and not as the primary anesthesia. Regional anesthesia has very few cardiovascular or pulmonary side-effects, as compared with general anesthesia. Pectoral nerve block is a relatively new technique, with fewer complications than other regional anesthesia. We performed Pecs I and Pec II block simultaneously as primary anesthesia under moderate sedation with dexmedetomidine for breast conserving surgery in a 49-year-old female patient with invasive ductal carcinoma. Block was uneventful and showed no complications. Thus, Pecs block with sedation could be an alternative to general anesthesia for breast surgeries.

Mesoporous Bragg reflectors: block-copolymer self-assembly leads to building blocks with well defined continuous pores and high control over optical properties

KAUST Repository

Guldin, S.; Kolle, M.; Stefik, M.; Wiesner, U.; Steiner, U.

2011-01-01

dened. Following a 30 min annealing protocol after each layer deposition enables the fast and reliable stacking of MDBRs which exhibit a continuous TiO2 network with large accessible pores and high optical quality.

49 CFR 236.708 - Block.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Block. 236.708 Section 236.708 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.708 Block. A length of track of defined limits, the use of which by trains is governed by block signals, cab signals, or both. ...

Ultrasound-Guided Single-Injection Infraclavicular Block Versus Ultrasound-Guided Double-Injection Axillary Block: A Noninferiority Randomized Controlled Trial.

Science.gov (United States)

Boivin, Ariane; Nadeau, Marie-Josée; Dion, Nicolas; Lévesque, Simon; Nicole, Pierre C; Turgeon, Alexis F

2016-01-01

Single-injection ultrasound-guided infraclavicular block is a simple, reliable, and effective technique. A simplified double-injection ultrasound-guided axillary block technique with a high success rate recently has been described. It has the advantage of being performed in a superficial and compressible location, with a potentially improved safety profile. However, its effectiveness in comparison with single-injection infraclavicular block has not been established. We hypothesized that the double-injection ultrasound-guided axillary block would show rates of complete sensory block at 30 minutes noninferior to the single-injection ultrasound-guided infraclavicular block. After approval by our research ethics committee and written informed consent, adults undergoing distal upper arm surgery were randomized to either group I, ultrasound-guided single-injection infraclavicular block, or group A, ultrasound-guided double-injection axillary block. In group I, 30 mL of 1.5% mepivacaine was injected posterior to the axillary artery. In group A, 25 mL of 1.5% mepivacaine was injected posteromedial to the axillary artery, after which 5 mL was injected around the musculocutaneous nerve. Primary outcome was the rate of complete sensory block at 30 minutes. Secondary outcomes were the onset of sensory and motor blocks, surgical success rates, performance times, and incidence of complications. All outcomes were assessed by a blinded investigator. The noninferiority of the double-injection ultrasound-guided axillary block was considered if the limits of the 90% confidence intervals (CIs) were within a 10% margin of the rate of complete sensory block of the infraclavicular block. At 30 minutes, the rate of complete sensory block was 79% in group A (90% CI, 71%-85%) compared with 91% in group I (90% CI, 85%-95%); the upper limit of CI of group A is thus included in the established noninferiority margin of 10%. The rate of complete sensory block was lower in group A (proportion

Block copolymer battery separator

Science.gov (United States)

Wong, David; Balsara, Nitash Pervez

2016-04-26

The invention herein described is the use of a block copolymer/homopolymer blend for creating nanoporous materials for transport applications. Specifically, this is demonstrated by using the block copolymer poly(styrene-block-ethylene-block-styrene) (SES) and blending it with homopolymer polystyrene (PS). After blending the polymers, a film is cast, and the film is submerged in tetrahydrofuran, which removes the PS. This creates a nanoporous polymer film, whereby the holes are lined with PS. Control of morphology of the system is achieved by manipulating the amount of PS added and the relative size of the PS added. The porous nature of these films was demonstrated by measuring the ionic conductivity in a traditional battery electrolyte, 1M LiPF.sub.6 in EC/DEC (1:1 v/v) using AC impedance spectroscopy and comparing these results to commercially available battery separators.

Atrial Fibrillation, Atrioventricular Blocks and Bundle Branch Blocks in Hemodialysis Patients

OpenAIRE

Mandic, Ante; Tomic, Monika; Petrov, Bozo; Romic, Zeljko

2012-01-01

Atrial fibrillation is one of the most frequent arrhythmias diagnosed in clinical practice and it is also relatively common in dialysis patients. Atrioventricular and intraventricular conduction disturbances are less investigated in hemodialysis patients and data about their prevalence are insufficient. The objective of this study was to determine the prevalence of atrial fibrillation, atrioventricular blocks and bundle branch blocks in hemodialysis patients and to analyze different clinical ...

Strength and deformability of hollow concrete blocks: correlation of block and cylindrical sample test results

Directory of Open Access Journals (Sweden)

C. S. Barbosa

Full Text Available This paper deals with correlations among mechanical properties of hollow blocks and those of concrete used to make them. Concrete hollow blocks and test samples were moulded with plastic consistency concrete, to assure the same material in all cases, in three diferente levels of strength (nominally 10 N/mm², 20 N/mm² and 30 N/mm². The mechanical properties and structural behaviour in axial compression and tension tests were determined by standard tests in blocks and cylinders. Stress and strain analyses were made based on concrete’s modulus of elasticity obtained in the sample tests as well as on measured strain in the blocks’ face-shells and webs. A peculiar stress-strain analysis, based on the superposition of effects, provided an estimation of the block load capacity based on its deformations. In addition, a tentative method to preview the block deformability from the concrete mechanical properties is described and tested. This analysis is a part of a broader research that aims to support a detailed structural analysis of blocks, prisms and masonry constructions.

Reversible chronic acquired complete atrioventricular block.

Science.gov (United States)

Rakovec, P; Milcinski, G; Voga, G; Korsic, L

1982-01-01

The return of atrioventricular conduction is reported in a case after nearly four years of complete acquired heart block. After recovery from atrioventricular block, right bundle branch block persisted, but P-R interval and H-V interval were normal. Three months later a relapse of second degree infranodal atrioventricular block was noted. A short review of similar cases from the literature is given.

Block-and-break generation of microdroplets with fixed volume

Science.gov (United States)

van Steijn, Volkert; Korczyk, Piotr M.; Derzsi, Ladislav; Abate, Adam R.; Weitz, David A.; Garstecki, Piotr

2013-01-01

We introduce a novel type of droplet generator that produces droplets of a volume set by the geometry of the droplet generator and not by the flow rates of the liquids. The generator consists of a classic T-junction with a bypass channel. This bypass directs the continuous fluid around the forming droplets, so that they can fill the space between the inlet of the dispersed phase and the exit of the bypass without breaking. Once filled, the dispersed phase blocks the exit of the bypass and is squeezed by the continuous fluid and broken off from the junction. We demonstrate the fixed-volume droplet generator for (i) the formation of monodisperse droplets from a source of varying flow rates, (ii) the formation of monodisperse droplets containing a gradation of solute concentration, and (iii) the parallel production of monodisperse droplets. PMID:24404013

Compaction of bentonite blocks. Development of techniques for production of blocks with different shapes and sizes

International Nuclear Information System (INIS)

Johannesson, Lars-Erik; Boergesson, Lennart

1998-09-01

In this report useful techniques for producing both smaller blocks manageable by man (10-15 kg) and larger blocks which need special equipment for handling (weight up to 600 kg) are described. Tests for producing blocks with a weight of approximately 10 kg were carried out at Hoeganaes Bjuf AB in Bjuv. This industry is normally producing refractory bricks and other refractory products. The plant has facilities for handling large volumes of clay. It also has machines suitable for producing uniaxially compacted blocks. Tests performed at the plant show that it is possible to compact blocks with good quality. The best quality was reached with a coarsely ground bentonite at a water ratio of 17 %. The compaction rate was high and performed with lubricated form and stepwise loading. Tests, in order to find a technique for producing larger blocks with a diameter of the same size as a deposition hole (about 1.65 m), were also made. The technique was developed in a smaller scale (250 mm). Ring-shaped blocks with the same outer diameter and with an inner diameter of about 156 mm were also compacted. The compaction was made with vacuum in the form. The outer surface of the form was conical and most of the tests were performed with a lubricated form. Tests were performed with different water ratios of the bentonite. All the blocks had a good quality. In consequence of the good test results a form with a 1000 mm diameter was constructed and a number of compaction tests were performed. The same technique was used as for the smaller blocks. The compaction pressure in most tests was 100 MPa (maximum compaction load 80.000 kN). The tests were performed at HYDROWELD in Ystad in a press with a maximum capacity of 300.000 kN. All tests were performed with MX-80. Most of the blocks had a good quality. A small damage close to the upper surface of all blocks was observed but is considered to be of no importance for the possibility to handle the blocks and is not affecting the properties

Compaction of bentonite blocks. Development of techniques for production of blocks with different shapes and sizes

Energy Technology Data Exchange (ETDEWEB)

Johannesson, Lars-Erik; Boergesson, Lennart [Clay Technology AB, Lund (Sweden)

1998-09-01

In this report useful techniques for producing both smaller blocks manageable by man (10-15 kg) and larger blocks which need special equipment for handling (weight up to 600 kg) are described. Tests for producing blocks with a weight of approximately 10 kg were carried out at Hoeganaes Bjuf AB in Bjuv. This industry is normally producing refractory bricks and other refractory products. The plant has facilities for handling large volumes of clay. It also has machines suitable for producing uniaxially compacted blocks. Tests performed at the plant show that it is possible to compact blocks with good quality. The best quality was reached with a coarsely ground bentonite at a water ratio of 17 %. The compaction rate was high and performed with lubricated form and stepwise loading. Tests, in order to find a technique for producing larger blocks with a diameter of the same size as a deposition hole (about 1.65 m), were also made. The technique was developed in a smaller scale (250 mm). Ring-shaped blocks with the same outer diameter and with an inner diameter of about 156 mm were also compacted. The compaction was made with vacuum in the form. The outer surface of the form was conical and most of the tests were performed with a lubricated form. Tests were performed with different water ratios of the bentonite. All the blocks had a good quality. In consequence of the good test results a form with a 1000 mm diameter was constructed and a number of compaction tests were performed. The same technique was used as for the smaller blocks. The compaction pressure in most tests was 100 MPa (maximum compaction load 80.000 kN). The tests were performed at HYDROWELD in Ystad in a press with a maximum capacity of 300.000 kN. All tests were performed with MX-80. Most of the blocks had a good quality. A small damage close to the upper surface of all blocks was observed but is considered to be of no importance for the possibility to handle the blocks and is not affecting the properties

Bullet-Block Science Video Puzzle

Science.gov (United States)

Shakur, Asif

2015-01-01

A science video blog, which has gone viral, shows a wooden block shot by a vertically aimed rifle. The video shows that the block hit dead center goes exactly as high as the one shot off-center. (Fig. 1). The puzzle is that the block shot off-center carries rotational kinetic energy in addition to the gravitational potential energy. This leads a…

Compatibilization of low-density polyethylene/polystyrene blends by segmented EB(PS-block-EB)(n) block copolymers

NARCIS (Netherlands)

Kroeze, E; ten Brinke, G.; Hadziioannou, G

Hydrogenated segmented poly[butadiene-block-(styrene-block-butadiene)(n)] block copolymers, which were developed by use of a polymeric iniferter technique, were tested on their compatibilizing effectiveness for (10/90) LDPE/PS blends. They were found to be effective compatibilizers for this mixture,

Light extraction block with curved surface

Science.gov (United States)

Levermore, Peter; Krall, Emory; Silvernail, Jeffrey; Rajan, Kamala; Brown, Julia J.

2016-03-22

Light extraction blocks, and OLED lighting panels using light extraction blocks, are described, in which the light extraction blocks include various curved shapes that provide improved light extraction properties compared to parallel emissive surface, and a thinner form factor and better light extraction than a hemisphere. Lighting systems described herein may include a light source with an OLED panel. A light extraction block with a three-dimensional light emitting surface may be optically coupled to the light source. The three-dimensional light emitting surface of the block may includes a substantially curved surface, with further characteristics related to the curvature of the surface at given points. A first radius of curvature corresponding to a maximum principal curvature k.sub.1 at a point p on the substantially curved surface may be greater than a maximum height of the light extraction block. A maximum height of the light extraction block may be less than 50% of a maximum width of the light extraction block. Surfaces with cross sections made up of line segments and inflection points may also be fit to approximated curves for calculating the radius of curvature.

Contributions of hard and soft blocks in the self-healing of metal-ligand-containing block copolymers

NARCIS (Netherlands)

Bose, Ranjita K.; Enke, Marcel; Grande, Antonio M.; Zechel, Stefan; Schacher, Felix H.; Hager, Martin D.; Garcia, Santiago J.; Schubert, Ulrich S.; van der Zwaag, Sybrand

2017-01-01

The main aim of this work is to study the respective contribution of the hard and soft blocks of a metal-ligand containing block copolymer to the self-healing behavior. To this aim, different block copolymers containing terpyridine were synthesized using reversible addition-fragmentation chain

Delayed appearance of hypaesthesia and paralysis after femoral nerve block

Directory of Open Access Journals (Sweden)

Stefan Landgraeber

2012-03-01

Full Text Available We report on a female patient who underwent an arthroscopy of the right knee and was given a continuous femoral nerve block catheter. The postoperative course was initially unremarkable, but when postoperative mobilisation was commenced, 18 hours after removal of the catheter, the patient noticed paralysis and hypaesthesia. Examination confirmed the diagnosis of femoral nerve dysfunction. Colour duplex sonography of the femoral artery and computed tomography of the lumbar spine and pelvis yielded no pathological findings. Overnight the neurological deficits decreased without therapy and were finally no longer detectable. We speculate that during the administration of the local anaesthetic a depot formed, localised in the medial femoral intermuscular septa, which was leaked after first mobilisation. To our knowledge no similar case has been published up to now. We conclude that patients who are treated with a nerve block should be informed and physician should be aware that delayed neurological deficits are possible.

Delayed appearance of hypaesthesia and paralysis after femoral nerve block

Science.gov (United States)

Landgraeber, Stefan; Albrecht, Thomas; Reischuck, Ulrich; von Knoch, Marius

2012-01-01

We report on a female patient who underwent an arthroscopy of the right knee and was given a continuous femoral nerve block catheter. The postoperative course was initially unremarkable, but when postoperative mobilisation was commenced, 18 hours after removal of the catheter, the patient noticed paralysis and hypaesthesia. Examination confirmed the diagnosis of femoral nerve dysfunction. Colour duplex sonography of the femoral artery and computed tomography of the lumbar spine and pelvis yielded no pathological findings. Overnight the neurological deficits decreased without therapy and were finally no longer detectable. We speculate that during the administration of the local anaesthetic a depot formed, localised in the medial femoral intermuscular septa, which was leaked after first mobilisation. To our knowledge no similar case has been published up to now. We conclude that patients who are treated with a nerve block should be informed and physician should be aware that delayed neurological deficits are possible. PMID:22577509

Contributions of hard and soft blocks in the self-healing of metal-ligand-containing block copolymers

NARCIS (Netherlands)

Bose, R.K.; Enke, Marcel; Grande, A.M.; Zechel, Stefan; Schacher, Felix H.; Hager, Martin D.; Garcia Espallargas, Santiago J.; Schubert, Ulrich S.; van der Zwaag, S.

2017-01-01

The main aim of this work is to study the respective contribution of the hard and soft blocks of a metal-ligand containing block copolymer to the self-healing behavior. To this aim, different block copolymers containing terpyridine were synthesized using reversible addition-fragmentation chain

Study of radioactivity diffusion for bitumen-coated blocks produced by an industrial coating plant

International Nuclear Information System (INIS)

Rodier, J.; Lefillatre, G.

1969-01-01

The solidification by bitumen of chemical coprecipitation sludges from the Marcoule waste treatment station has been studied in the laboratory and has led to the construction of an industrial coating plant. The quality of the coated material obtained has been controlled by the lixiviation test carried out with ordinary water and with sea-water on 45 ml laboratory samples and on industrial coated blocks of 150 litres. Tests on blocks of such a size have necessitated the installation of three special tanks. Two, each of 2000 litres capacity, contain ordinary and sea-water which was continuously recycled at a rate of 2.5 cm/hr and renewed periodically. In the third tank having a capacity of 11000 litres, the coated block was buried in earth and sprinkled with ordinary water with a view to studying the migration of radioelements in soil. The results of these tests confirm those obtained during the laboratory experiments. (authors) [fr

Blending of styrene-block-butadiene-block-styrene copolymer with sulfonated vinyl aromatic polymers

NARCIS (Netherlands)

Ruggeri, Giacomo; Passaglia, Elisa; Giorgi, Ivan; Picchioni, Francesco; Aglietto, Mauro

2001-01-01

Different polymers containing sulfonic groups attached to the phenyl rings were prepared by sulfonation of polystyrene (PS) and styrene-block-(ethylene-co-1-butene)-block-styrene (SEBS). The sulfonation degree (SD) was varied between 1 and 20 mol% of the styrene units. Polyphase materials containing

Comparison of the Cellient(™) automated cell block system and agar cell block method.

Science.gov (United States)

Kruger, A M; Stevens, M W; Kerley, K J; Carter, C D

2014-12-01

To compare the Cellient(TM) automated cell block system with the agar cell block method in terms of quantity and quality of diagnostic material and morphological, histochemical and immunocytochemical features. Cell blocks were prepared from 100 effusion samples using the agar method and Cellient system, and routinely sectioned and stained for haematoxylin and eosin and periodic acid-Schiff with diastase (PASD). A preliminary immunocytochemical study was performed on selected cases (27/100 cases). Sections were evaluated using a three-point grading system to compare a set of morphological parameters. Statistical analysis was performed using Fisher's exact test. Parameters assessing cellularity, presence of single cells and definition of nuclear membrane, nucleoli, chromatin and cytoplasm showed a statistically significant improvement on Cellient cell blocks compared with agar cell blocks (P cell groups, PASD staining or the intensity or clarity of immunocytochemical staining. A discrepant immunocytochemistry (ICC) result was seen in 21% (13/63) of immunostains. The Cellient technique is comparable with the agar method, with statistically significant results achieved for important morphological features. It demonstrates potential as an alternative cell block preparation method which is relevant for the rapid processing of fine needle aspiration samples, malignant effusions and low-cellularity specimens, where optimal cell morphology and architecture are essential. Further investigation is required to optimize immunocytochemical staining using the Cellient method. © 2014 John Wiley & Sons Ltd.

Two injection digital block versus single subcutaneous palmar injection block for finger lacerations.

Science.gov (United States)

Okur, O M; Şener, A; Kavakli, H Ş; Çelik, G K; Doğan, N Ö; Içme, F; Günaydin, G P

2017-12-01

We aimed to compare two digital nerve block techniques in patients due to traumatic digital lacerations. This was a randomized-controlled study designed prospectively in the emergency department of a university-based training and research hospital. Randomization was achieved by sealed envelopes. Half of the patients were randomised to traditional (two-injection) digital nerve block technique while single-injection digital nerve block technique was applied to the other half. Score of pain due to anesthetic infiltration and suturing, onset time of total anesthesia, need for an additional rescue injection were the parameters evaluated with both groups. Epinephrin added lidocaine hydrochloride preparation was used for the anesthetic application. Visual analog scale was used for the evaluation of pain scores. Outcomes were compared by using Mann-Whitney U test and Student t-test. Fifty emergency department patients ≥18 years requiring digital nerve block were enrolled in the study. Mean age of the patients was 33 (min-max: 19-86) and 39 (78 %) were male. No statistically significant difference was found between the two groups in terms of our main parameters; anesthesia pain score, suturing pain score, onset time of total anesthesia and rescue injection need. Single injection volar digital nerve block technique is a suitable alternative for digital anesthesias in emergency departments.

Related Drupal Nodes Block

NARCIS (Netherlands)

Van der Vegt, Wim

2010-01-01

Related Drupal Nodes Block This module exposes a block that uses Latent Semantic Analysis (Lsa) internally to suggest three nodes that are relevant to the node a user is viewing. This module performs three tasks. 1) It periodically indexes a Drupal site and generates a Lsa Term Document Matrix.

Application of multi-block methods in cement production

DEFF Research Database (Denmark)

Svinning, K.; Høskuldsson, Agnar

2008-01-01

distribution and the two last blocks the superficial microstructure analysed by differential thermo gravimetric analysis. The multi-block method is used to identify the role of each part. The score vectors of each block can be analysed separately or together with score vectors of other blocks. Stepwise......Compressive strength at 1 day of Portland cement as a function of the microstructure of cement was statistically modelled by application of multi-block regression method. The observation X-matrix was partitioned into four blocks, the first block representing the mineralogy, the second particle size...... regression is used to find minimum number of variables of each block. The multi-block method proved useful in determining the modelling strength of each data block and finding minimum number of variables within each data block....

Subpleural thoracic fat as defined with CT of the chest

International Nuclear Information System (INIS)

Anderson, D.J.; Glazer, H.S.; Molina, P.L.; Sagel, S.S.

1988-01-01

Consecutive computed tomographic (CT) examinations of the chest (n=202) were reviewed to determine the location, thickness, and extent of subpleural fat. Patient age, thickness of subcutaneous fat, and adjacent pleural or parenchymal abnormalities were recorded. Subpleural fat was most often identified in the paravertebral region (48%) and in the apices (23%). Fatty deposits anterolaterally were seen in seven individuals. Subpleural fat thickness ranged from 1 to 19 mm, except in the apex, where fat sometimes filled the space. A direct relationship between subcutaneous fat thickness and a higher incidence of subpleural fat was observed in the paravertebral region. Subpleural fat occurs commonly in the paravertebral regions but is unusual in other areas

Right bundle branch block

DEFF Research Database (Denmark)

Bussink, Barbara E; Holst, Anders Gaarsdal; Jespersen, Lasse

2013-01-01

AimsTo determine the prevalence, predictors of newly acquired, and the prognostic value of right bundle branch block (RBBB) and incomplete RBBB (IRBBB) on a resting 12-lead electrocardiogram in men and women from the general population.Methods and resultsWe followed 18 441 participants included...... in the Copenhagen City Heart Study examined in 1976-2003 free from previous myocardial infarction (MI), chronic heart failure, and left bundle branch block through registry linkage until 2009 for all-cause mortality and cardiovascular outcomes. The prevalence of RBBB/IRBBB was higher in men (1.4%/4.7% in men vs. 0.......5%/2.3% in women, P block was associated with significantly...

Uniaxial backfill block compaction

International Nuclear Information System (INIS)

Koskinen, V.

2012-05-01

The main parts of the project were: to make a literature survey of the previous uniaxial compaction experiments; do uniaxial compaction tests in laboratory scale; and do industrial scale production tests. Object of the project was to sort out the different factors affecting the quality assurance chain of the backfill block uniaxial production and solve a material sticking to mould problem which appeared during manufacturing the blocks of bentonite and cruched rock mixture. The effect of mineralogical and chemical composition on the long term functionality of the backfill was excluded from the project. However, the used smectite-rich clays have been tested for mineralogical consistency. These tests were done in B and Tech OY according their SOPs. The objective of the Laboratory scale tests was to find right material- and compaction parameters for the industrial scale tests. Direct comparison between the laboratory scale tests and industrial scale tests is not possible because the mould geometry and compaction speed has a big influence for the compaction process. For this reason the selected material parameters were also affected by the previous compaction experiments. The industrial scale tests were done in summer of 2010 in southern Sweden. Blocks were done with uniaxial compaction. A 40 tons of the mixture of bentonite and crushed rock blocks and almost 50 tons of Friedland-clay blocks were compacted. (orig.)

Impression block with orientator

International Nuclear Information System (INIS)

Brilin, V I; Ulyanova, O S

2015-01-01

Tool review, namely the impression block, applied to check the shape and size of the top of fish as well as to determine the appropriate tool for fishing operation was realized. For multiple application and obtaining of the impress depth of 3 cm and more, the standard volumetric impression blocks with fix rods are used. However, the registered impress of fish is not oriented in space and the rods during fishing are in the extended position. This leads to rods deformation and sinking due to accidental impacts of impression block over the borehole irregularity and finally results in faulty detection of the top end of fishing object in hole. The impression blocks with copy rods and fixed magnetic needle allow estimating the object configuration and fix the position of magnetic needle determining the position of the top end of object in hole. However, the magnetic needle fixation is realized in staged and the rods are in extended position during fishing operations as well as it is in standard design. The most efficient tool is the impression block with copy rods which directs the examined object in the borehole during readings of magnetic needles data from azimuth plate and averaging of readings. This significantly increases the accuracy of fishing toll direction. The rods during fishing are located in the body and extended only when they reach the top of fishing object

Phrenic nerve block caused by interscalene brachial plexus block: breathing effects of different sites of injection.

Science.gov (United States)

Bergmann, Lars; Martini, Stefan; Kesselmeier, Miriam; Armbruster, Wolf; Notheisen, Thomas; Adamzik, Michael; Eichholz, Rϋdiger

2016-07-29

Interscalene brachial plexus (ISB) block is often associated with phrenic nerve block and diaphragmatic paresis. The goal of our study was to test if the anterior or the posterior ultrasound guided approach of the ISB is associated with a lower incidence of phrenic nerve blocks and impaired lung function. This was a prospective, randomized and single-blinded study of 84 patients scheduled for elective shoulder surgery who fullfilled the inclusion and exclusion critereria. Patients were randomized in two groups to receive either the anterior (n = 42) or the posterior (n = 42) approach for ISB. Clinical data were recorded. In both groups patients received ISB with a total injection volume of 15 ml of ropivacaine 1 %. Spirometry was conducted at baseline (T0) and 30 min (T30) after accomplishing the block. Changes in spirometrical variables between T0 and T30 were investigated by Wilcoxon signed-rank test for each puncture approach. The temporal difference between the posterior and the anterior puncture approach groups were again analyzed by the Wilcoxon-Mann-Whitney test. The spirometric results showed a significant decrease in vital capacity, forced expiratory volume per second, and maximum nasal inspiratory breathing after the Interscalene brachial plexus block; indicating a phrenic nerve block (p Wilcoxon signed-rank). A significant difference in the development of the spirometric parameters between the anterior and the posterior group could not be identified (Wilcoxon-Mann-Whitney test). Despite the changes in spirometry, no cases of dyspnea were reported. A different site of injection (anterior or posterior) did not show an effect in reducing the cervical block spread of the local anesthetic and the incidence of phrenic nerve blocks during during ultrasound guided Interscalene brachial plexus block. Clinical breathing effects of phrenic nerve blocks are, however, usually well compensated, and subjective dyspnea did not occur in our patients. German

Toward Composable Hardware Agnostic Communications Blocks Lessons Learned

Science.gov (United States)

2016-11-01

block-by-block level or on a multi- block level. In the block-by-block pushback approach, queues between each block are small and blocks processing data...medium access, and physical layers of the waveform has limited our ability to take advantage of technology advances in signal processing , rate...pro- cessing functions, and application processing functions as shown in Figure 1 [1]. Transceiver functions are functions associated with transmitting

Micellar aggregates of amylose-block-polystyrene rod-coil block copolymers in water and THF

NARCIS (Netherlands)

Loos, Katja; Böker, Alexander; Zettl, Heiko; Zhang, Mingfu; Krausch, Georg; Müller, Axel H.E.; Boker, A.; Zhang, A.F.

2005-01-01

Amylose-block-polystyrenes with various block copolymer compositions were investigated in water and in THF solution. Fluorescence correlation spectroscopy, dynamic light, scattering (DLS), and asymmetric flow field-flow fractionation with multiangle light scattering detection indicate the presence

Habitat Blocks and Wildlife Corridors

Data.gov (United States)

Vermont Center for Geographic Information — Habitat blocks are areas of contiguous forest and other natural habitats that are unfragmented by roads, development, or agriculture. Vermonts habitat blocks are...

Controlling sub-microdomain structure in microphase-ordered block copolymers and their nanocomposites

Science.gov (United States)

Bowman, Michelle Kathleen

Block copolymers exhibit a wealth of morphologies that continue to find ubiquitous use in a diverse variety of mature and emergent (nano)technologies, such as photonic crystals, integrated circuits, pharmaceutical encapsulents, fuel cells and separation membranes. While numerous studies have explored the effects of molecular confinement on such copolymers, relatively few have examined the sub-microdomain structure that develops upon modification of copolymer molecular architecture or physical incorporation of nanoscale objects. This work will address two relevant topics in this vein: (i) bidisperse brushes formed by single block copolymer molecules and (ii) copolymer nanocomposites formed by addition of molecular or nanoscale additives. In the first case, an isomorphic series of asymmetric poly(styrene-b -isoprene-b-styrene) (S1IS2) triblock copolymers of systematically varied chain length has been synthesized from a parent SI diblock copolymer. Small-angle x-ray scattering, coupled with dynamic rheology and self-consistent field theory (SCFT), reveals that the progressively grown S2 block initially resides in the I-rich matrix and effectively reduces the copolymer incompatibility until a critical length is reached. At this length, the S2 block co-locates with the S1 block so that the two blocks generate a bidisperse brush (insofar as the S1 and S2 lengths differ). This single-molecule analog to binary block copolymer blends affords unique opportunities for materials design at sub-microdomain length scales and provides insight into the transition from diblock to triblock copolymer (and thermoplastic elastomeric nature). In the second case, I explore the distribution of molecular and nanoscale additives in microphase-ordered block copolymers and demonstrate via SCFT that an interfacial excess, which depends strongly on additive concentration, selectivity and relative size, develops. These predictions are in agreement with experimental findings. Moreover, using a

A novel closed reduction with extension block and flexion block using Kirschner wires and microscrew fixation for mallet fractures.

Science.gov (United States)

Shimura, Haruhiko; Wakabayashi, Yoshiaki; Nimura, Akimoto

2014-03-01

Some patients with mallet fractures who undergo extension block pinning complain of exposed wires, which delay their return to sports and causes inconvenience while performing tasks that require the use of hands during the early postoperative period. The purpose of this retrospective study was to present and evaluate a novel surgical procedure for mallet fractures. We treated 20 patients (14 males and six females; mean age, 38.4 years; range 17-68 years) with displaced mallet fractures involving >30 % of the articular surface using the closed reduction and microscrew fixation between January 2009 and January 2012. The distal interphalangeal joint (DIP) joint was immobilized with a splint for 1-3 weeks on an individual case basis. According to Wehbe and Schneider's classification, there were 12 type IB, six type IIB, and two type IA fractures. The mean follow-up duration was 12.6 months (range 6-31 months). Bone union was achieved in all patients within a mean period of 6.8 weeks, with no incidence of infection, skin necrosis, permanent nail deformity, or secondary osteoarthritis. Only two complications-temporary nail ridging in one patient and a dorsal bump caused by the screw in one patient-were observed. Minimum postoperative displacement was observed in one patient, for whom immobilization with a splint was continued for 4 weeks. Articular incongruity was <1.0 mm in four patients and 1.0-2.0 mm in two patients. Mean DIP joint extension loss was 6.5° and mean flexion was 67.8°. The surgical outcomes were excellent in seven patients, good in nine, and fair in four according to Crawford's evaluation criteria. Our novel surgical procedure combining closed reduction with extension block and flexion block using Kirschner wires and microscrew fixation produces good clinical results with relatively few complications.

Recursion Relations for Conformal Blocks

CERN Document Server

Penedones, João; Yamazaki, Masahito

2016-09-12

In the context of conformal field theories in general space-time dimension, we find all the possible singularities of the conformal blocks as functions of the scaling dimension $\\Delta$ of the exchanged operator. In particular, we argue, using representation theory of parabolic Verma modules, that in odd spacetime dimension the singularities are only simple poles. We discuss how to use this information to write recursion relations that determine the conformal blocks. We first recover the recursion relation introduced in 1307.6856 for conformal blocks of external scalar operators. We then generalize this recursion relation for the conformal blocks associated to the four point function of three scalar and one vector operator. Finally we specialize to the case in which the vector operator is a conserved current.

Block-Parallel Data Analysis with DIY2

Energy Technology Data Exchange (ETDEWEB)

Morozov, Dmitriy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Peterka, Tom [Argonne National Lab. (ANL), Argonne, IL (United States)

2017-08-30

DIY2 is a programming model and runtime for block-parallel analytics on distributed-memory machines. Its main abstraction is block-structured data parallelism: data are decomposed into blocks; blocks are assigned to processing elements (processes or threads); computation is described as iterations over these blocks, and communication between blocks is defined by reusable patterns. By expressing computation in this general form, the DIY2 runtime is free to optimize the movement of blocks between slow and fast memories (disk and flash vs. DRAM) and to concurrently execute blocks residing in memory with multiple threads. This enables the same program to execute in-core, out-of-core, serial, parallel, single-threaded, multithreaded, or combinations thereof. This paper describes the implementation of the main features of the DIY2 programming model and optimizations to improve performance. DIY2 is evaluated on benchmark test cases to establish baseline performance for several common patterns and on larger complete analysis codes running on large-scale HPC machines.

Assessment of exit block following pulmonary vein isolation: far-field capture masquerading as entrance without exit block.

Science.gov (United States)

Vijayaraman, Pugazhendhi; Dandamudi, Gopi; Naperkowski, Angela; Oren, Jess; Storm, Randle; Ellenbogen, Kenneth A

2012-10-01

Complete electrical isolation of pulmonary veins (PVs) remains the cornerstone of ablation therapy for atrial fibrillation. Entrance block without exit block has been reported to occur in 40% of the patients. Far-field capture (FFC) can occur during pacing from the superior PVs to assess exit block, and this may appear as persistent conduction from PV to left atrium (LA). To facilitate accurate assessment of exit block. Twenty consecutive patients with symptomatic atrial fibrillation referred for ablation were included in the study. Once PV isolation (entrance block) was confirmed, pacing from all the bipoles on the Lasso catheter was used to assess exit block by using a pacing stimulus of 10 mA at 2 ms. Evidence for PV capture without conduction to LA was necessary to prove exit block. If conduction to LA was noticed, pacing output was decreased until there was PV capture without conduction to LA or no PV capture was noted to assess for far-field capture in both the upper PVs. All 20 patients underwent successful isolation (entrance block) of all 76 (4 left common PV) veins: mean age 58 ± 9 years; paroxysmal atrial fibrillation 40%; hypertension 70%, diabetes mellitus 30%, coronary artery disease 15%; left ventricular ejection fraction 55% ± 10%; LA size 42 ± 11 mm. Despite entrance block, exit block was absent in only 16% of the PVs, suggesting persistent PV to LA conduction. FFC of LA appendage was noted in 38% of the left superior PVs. FFC of the superior vena cava was noted in 30% of the right superior PVs. The mean pacing threshold for FFC was 7 ± 4 mA. Decreasing pacing output until only PV capture (loss of FFC) is noted was essential to confirm true exit block. FFC of LA appendage or superior vena cava can masquerade as persistent PV to LA conduction. A careful assessment for PV capture at decreasing pacing output is essential to exclude FFC. Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Screening and managing obstructive sleep apnoea in nocturnal heart block patients: an observational study.

Science.gov (United States)

Wu, Xu; Liu, Zilong; Chang, Su Chi; Fu, Cuiping; Li, Wenjing; Jiang, Hong; Jiang, Liyan; Li, Shanqun

2016-02-16

Nocturnal heart block often occurs in patients with obstructive sleep apnoea (OSA). It is more likely to be undiagnosed in heart block patients who are ignorant of the symptoms of sleep disorder. Berlin Questionnaire (BQ) is a highly reliable way to discover the risk factors of OSA, whereas the validity in sleep-related heart block patients is uncertain. We performed an observational study to address these issues and confirmed the potential protective effect of continuous positive airway pressure (CPAP). Patients who were previously diagnosed with nocturnal heart block with R-R pauses exceeding 2 seconds were retrospective screened from the ECG centre of Zhongshan hospital. These recruited participants completed Berlin Questionnaire and underwent polysomnography synchronously with 24-hour Holter monitoring. A cross-sectional analysis was performed to confirm the association between nocturnal arrhythmia and OSA, as well as to assess the diagnostic accuracy of the BQ. Subsequently, subjects diagnosed with OSA (apnoea-hypopnoea index > 5) underwent 3 consecutive days of CPAP therapy. On the third day, patients repeated 24-hour Holter monitoring within the institution of CPAP. The symptoms of disruptive snoring and hypersomnolence in 72 enrolled patients were more related to the occurrence of nocturnal heart block (r = 0.306, 0.226, respectively, p = 0.015, 0.019) than syncope (r = 0.134, p = 0.282) and palpitations (r = 0.106, p = 0.119), which were prominent trait of our study population. The sensitivity, specificity, positive and negative predictive value of the BQ at a cut-off point of 5 of AHI for detecting OSA in heart block patients was 81.0 %, 44.4 %, 91.07 % and 25 %. Nocturnal heart block does not appear to occur exclusively in severe sleep apnoea. The frequent occurrence of arrhythmias in prominent oxygen desaturation supports the correlation between them. CPAP therapy resulted in significant decrease in the average number of

Nanoporous polymeric nanofibers based on selectively etched PS-b-PDMS block copolymers.

Science.gov (United States)

Demirel, Gokcen B; Buyukserin, Fatih; Morris, Michael A; Demirel, Gokhan

2012-01-01

One-dimensional nanoporous polymeric nanofibers have been fabricated within an anodic aluminum oxide (AAO) membrane by a facile approach based on selective etching of poly(dimethylsiloxane) (PDMS) domains in polystyrene-block-poly(dimethylsiloxane) (PS-b-PDMS) block copolymers that had been formed within the AAO template. It was observed that prior to etching, the well-ordered PS-b-PDMS nanofibers are solid and do not have any porosity. The postetched PS nanofibers, on the other hand, had a highly porous structure having about 20-50 nm pore size. The nanoporous polymeric fibers were also employed as a drug carrier for the native, continuous, and pulsatile drug release using Rhodamine B (RB) as a model drug. These studies showed that enhanced drug release and tunable drug dosage can be achieved by using ultrasound irradiation. © 2011 American Chemical Society

Atrioventricular block, ECG tracing (image)

Science.gov (United States)

... an abnormal rhythm (arrhythmia) called an atrioventricular (AV) block. P waves show that the top of the ... wave (and heart contraction), there is an atrioventricular block, and a very slow pulse (bradycardia).

Quadratus Lumborum Block Versus Transversus Abdominis Plane Block for Postoperative Pain After Cesarean Delivery: A Randomized Controlled Trial.

Science.gov (United States)

Blanco, Rafael; Ansari, Tarek; Riad, Waleed; Shetty, Nanda

Effective postoperative analgesia after cesarean delivery enhances early recovery, ambulation, and breastfeeding. In a previous study, we established the effectiveness of the quadratus lumborum block in providing pain relief after cesarean delivery compared with patient-controlled analgesia (morphine). In the current study, we hypothesized that this method would be equal to or better than the transversus abdominis plane block with regard to pain relief and its duration of action after cesarean delivery. Between April 2015 and August 2015, we randomized 76 patients scheduled for elective cesarean delivery under spinal anesthesia to receive the quadratus lumborum block or the transversus abdominis plane block for postoperative pain relief. This trial was registered prospectively (NCT 02489851) [corrected]. Patients in the quadratus lumborum block group used significantly less morphine than the transversus abdominis plane block group (P consumption and demands than transversus abdominis plane blocks after cesarean section. This effect was observed up to 48 hours postoperatively.

[THE TECHNOLOGY "CELL BLOCK" IN CYTOLOGICAL PRACTICE].

Science.gov (United States)

Volchenko, N N; Borisova, O V; Baranova, I B

2015-08-01

The article presents summary information concerning application of "cell block" technology in cytological practice. The possibilities of implementation of various modern techniques (immune cytochemnical analysis. FISH, CISH, polymerase chain reaction) with application of "cell block" method are demonstrated. The original results of study of "cell block" technology made with gelatin, AgarCyto and Shadon Cyoblock set are presented. The diagnostic effectiveness of "cell block" technology and common cytological smear and also immune cytochemical analysis on samples of "cell block" technology and fluid cytology were compared. Actually application of "cell block" technology is necessary for ensuring preservation of cell elements for subsequent immune cytochemical and molecular genetic analysis.

System Level Design of a Continuous-Time Delta-Sigma Modulator for Portable Ultrasound Scanners

DEFF Research Database (Denmark)

Llimos Muntal, Pere; Færch, Kjartan; Jørgensen, Ivan Harald Holger

2015-01-01

In this paper the system level design of a continuous-time ∆Σ modulator for portable ultrasound scanners is presented. The overall required signal-to-noise ratio (SNR) is derived to be 42 dB and the sampling frequency used is 320 MHz for an oversampling ratio of 16. In order to match these requir......, based on high-level VerilogA simulations, the performance of the ∆Σ modulator versus various block performance parameters is presented as trade-off curves. Based on these results, the block specifications are derived.......In this paper the system level design of a continuous-time ∆Σ modulator for portable ultrasound scanners is presented. The overall required signal-to-noise ratio (SNR) is derived to be 42 dB and the sampling frequency used is 320 MHz for an oversampling ratio of 16. In order to match...

21 CFR 520.1448a - Monensin blocks.

Science.gov (United States)

2010-04-01

...) Limitations. Block to be fed free choice to pasture cattle (slaughter, stocker, feeder, and dairy and beef.... Blocks to be fed free choice to pasture cattle (slaughter, stocker, feeder, and dairy and beef.... Blocks to be fed free choice to pasture cattle (slaughter, stocker, and feeder). Provide at least 1 block...

Approximating the imbibition and absorption behavior of a distribution of matrix blocks by an equivalent spherical block

International Nuclear Information System (INIS)

Zimmerman, R.W.; Bodvarsson, G.S.

1994-03-01

A theoretical study is presented of the effect of matrix block shape and matrix block size distribution on liquid imbibition and solute absorption in a fractured rock mass. It is shown that the behavior of an individual irregularly-shaped matrix block can be modeled with reasonable accuracy by using the results for a spherical matrix block, if one uses an effective radius a = 3V/A, where V is the volume of the block and A is its surface area. In the early-time regime of matrix imbibition, it is shown that a collection of blocks of different sizes can be modeled by a single equivalent block, with an equivalent radius of -1 > -1 , where the average is taken on a volumetrically-weighted basis. In an intermediate time regime, it is shown for the case where the radii are normally distributed that the equivalent radius is reasonably well approximated by the mean radius . In the long-time limit, where no equivalent radius can be rigorously defined, an asymptotic expression is derived for the cumulative diffusion as a function of the mean and the standard deviation of the radius distribution function

Application of interconnected porous hydroxyapatite ceramic block for onlay block bone grafting in implant treatment: A case report.

Science.gov (United States)

Ohta, Kouji; Tada, Misato; Ninomiya, Yoshiaki; Kato, Hiroki; Ishida, Fumi; Abekura, Hitoshi; Tsuga, Kazuhiro; Takechi, Masaaki

2017-12-01

Autogenous block bone grafting as treatment for alveolar ridge atrophy has various disadvantages, including a limited availability of sufficiently sized and shaped grafts, donor site morbidity and resorption of the grafted bone. As a result, interconnected porous hydroxyapatite ceramic (IP-CHA) materials with high porosity have been developed and used successfully in orthopedic cases. To the best of the author's knowledge, this is the first report of clinical application of an IP-CHA block for onlay grafting for implant treatment in a patient with horizontal alveolar atrophy. The present study performed onlay block grafting using an IP-CHA block to restore bone volume for implant placement in the alveolar ridge area without collecting autogenous bone. Dental X-ray findings revealed that the border of the IP-CHA block became increasingly vague over the 3-year period, whereas CT scanning revealed that the gap between the block and bone had a smooth transition, indicating that IP-CHA improved the process of integration with host bone. In follow-up examinations over a period of 5 years, the implants and superstructures had no problems. An IP-CHA block may be useful as a substitute for onlay block bone grafting in implant treatment.

Ultrasound guided TAP block versus ultrasound guided caudal block for pain relief in children undergoing lower abdominal surgeries

Directory of Open Access Journals (Sweden)

Wafaa Mohamed Alsadek

2015-04-01

Conclusion: TAP block and caudal block under ultrasound guidance proved to be safe with no recorded complications either intra or postoperatively. Patient and parent satisfaction was markedly observed in case of TAP block.

Naming Block Structures: A Multimodal Approach

Science.gov (United States)

Cohen, Lynn; Uhry, Joanna

2011-01-01

This study describes symbolic representation in block play in a culturally diverse suburban preschool classroom. Block play is "multimodal" and can allow children to experiment with materials to represent the world in many forms of literacy. Combined qualitative and quantitative data from seventy-seven block structures were collected and analyzed.…

Method for quantifying percentage wood failure in block-shear specimens by a laser scanning profilometer

Science.gov (United States)

C. T. Scott; R. Hernandez; C. Frihart; R. Gleisner; T. Tice

2005-01-01

A new method for quantifying percentage wood failure of an adhesively bonded block-shear specimen has been developed. This method incorporates a laser displacement gage with an automated two-axis positioning system that functions as a highly sensitive profilometer. The failed specimen is continuously scanned across its width to obtain a surface failure profile. The...

Using Interference to Block RFID Tags

DEFF Research Database (Denmark)

Krigslund, Rasmus; Popovski, Petar; Pedersen, Gert Frølund

We propose a novel method to block RFID tags from responding, using intentional interference. We focus on the experimental evaluation, where we impose interference on the download and uplink, respectively. The results are positive, where modulated CCI shows most effective to block a tag.......We propose a novel method to block RFID tags from responding, using intentional interference. We focus on the experimental evaluation, where we impose interference on the download and uplink, respectively. The results are positive, where modulated CCI shows most effective to block a tag....

Ground reaction curve based upon block theory

International Nuclear Information System (INIS)

Yow, J.L. Jr.; Goodman, R.E.

1985-09-01

Discontinuities in a rock mass can intersect an excavation surface to form discrete blocks (keyblocks) which can be unstable. Once a potentially unstable block is identified, the forces affecting it can be calculated to assess its stability. The normal and shear stresses on each block face before displacement are calculated using elastic theory and are modified in a nonlinear way by discontinuity deformations as the keyblock displaces. The stresses are summed into resultant forces to evaluate block stability. Since the resultant forces change with displacement, successive increments of block movement are examined to see whether the block ultimately becomes stable or fails. Two-dimensional (2D) and three-dimensional (3D) analytic models for the stability of simple pyramidal keyblocks were evaluated. Calculated stability is greater for 3D analyses than for 2D analyses. Calculated keyblock stability increases with larger in situ stress magnitudes, larger lateral stress ratios, and larger shear strengths. Discontinuity stiffness controls blocks displacement more strongly than it does stability itself. Large keyblocks are less stable than small ones, and stability increases as blocks become more slender

CHOBS: Color Histogram of Block Statistics for Automatic Bleeding Detection in Wireless Capsule Endoscopy Video.

Science.gov (United States)

Ghosh, Tonmoy; Fattah, Shaikh Anowarul; Wahid, Khan A

2018-01-01

Wireless capsule endoscopy (WCE) is the most advanced technology to visualize whole gastrointestinal (GI) tract in a non-invasive way. But the major disadvantage here, it takes long reviewing time, which is very laborious as continuous manual intervention is necessary. In order to reduce the burden of the clinician, in this paper, an automatic bleeding detection method for WCE video is proposed based on the color histogram of block statistics, namely CHOBS. A single pixel in WCE image may be distorted due to the capsule motion in the GI tract. Instead of considering individual pixel values, a block surrounding to that individual pixel is chosen for extracting local statistical features. By combining local block features of three different color planes of RGB color space, an index value is defined. A color histogram, which is extracted from those index values, provides distinguishable color texture feature. A feature reduction technique utilizing color histogram pattern and principal component analysis is proposed, which can drastically reduce the feature dimension. For bleeding zone detection, blocks are classified using extracted local features that do not incorporate any computational burden for feature extraction. From extensive experimentation on several WCE videos and 2300 images, which are collected from a publicly available database, a very satisfactory bleeding frame and zone detection performance is achieved in comparison to that obtained by some of the existing methods. In the case of bleeding frame detection, the accuracy, sensitivity, and specificity obtained from proposed method are 97.85%, 99.47%, and 99.15%, respectively, and in the case of bleeding zone detection, 95.75% of precision is achieved. The proposed method offers not only low feature dimension but also highly satisfactory bleeding detection performance, which even can effectively detect bleeding frame and zone in a continuous WCE video data.

Strength and deformability of hollow concrete blocks: correlation of block and cylindrical sample test results

OpenAIRE

Barbosa, C. S.; Hanai, J.B.

2009-01-01

This paper deals with correlations among mechanical properties of hollow blocks and those of concrete used to make them. Concrete hollow blocks and test samples were moulded with plastic consistency concrete, to assure the same material in all cases, in three diferente levels of strength (nominally 10 N/mm², 20 N/mm² and 30 N/mm²). The mechanical properties and structural behaviour in axial compression and tension tests were determined by standard tests in blocks and cylinders. Stress and str...

Encoders for block-circulant LDPC codes

Science.gov (United States)

Divsalar, Dariush (Inventor); Abbasfar, Aliazam (Inventor); Jones, Christopher R. (Inventor); Dolinar, Samuel J. (Inventor); Thorpe, Jeremy C. (Inventor); Andrews, Kenneth S. (Inventor); Yao, Kung (Inventor)

2009-01-01

Methods and apparatus to encode message input symbols in accordance with an accumulate-repeat-accumulate code with repetition three or four are disclosed. Block circulant matrices are used. A first method and apparatus make use of the block-circulant structure of the parity check matrix. A second method and apparatus use block-circulant generator matrices.

How to block and tackle the face.

Science.gov (United States)

Zide, B M; Swift, R

1998-03-01

Regional blocking techniques as noted in dentistry, anesthesia, and anatomy texts may result in inconsistent and imperfect analgesia when needed for facial aesthetic surgery. The advent of laser facial surgery and more complicated aesthetic facial procedures has thus increased the demand for anesthesia support. Surgeons should know a fail-safe method of nerve blocks. Fresh cadaver dissections are used to demonstrate a series of eight regional nerve-blocking routes. This sequence of bilateral blocks will routinely provide profound full facial anesthesia. Certain groupings of blocks are effective for perioral or periorbital laser surgery.

The effect of UV-blocking contact lenses as a therapy for canine chronic superficial keratitis.

Science.gov (United States)

Denk, Nora; Fritsche, Jens; Reese, Sven

2011-05-01

To evaluate the effect of UV-blocking soft contact lenses in treatment for chronic superficial keratitus (CSK). Twenty six dogs with CSK were treated continuously with UV-blocking contact lenses for 6 months. A contact lens was placed on one eye of each dog; the other eye remained without a lens as a control eye. After this primary study, five of the dogs were further treated and they wore then contact lenses in both eyes. Continuously, all patients were concurrently treated topically with cyclosporine. The contact lenses were changed every 4 weeks and an ophthalmic examination performed. Evaluation criteria included corneal alterations as pigmentation, edema, pannus and vascularization. To determine the transmittance characteristics of the contact lenses before and after use, 32 contact lenses were measured with a UV-vis-NIR spectrophotometer. Pigmentation increased in eyes wearing lenses and in control eyes over the evaluation period of 6 months. Corneal edema increased in the eyes wearing lenses, but remained unaffected in the control eyes. A significant difference in the incidence of pannus and the extent of corneal vascularisation could not be evaluated. Adverse effects were noted in six cases (corneal edema and vascularisation, conjunctivitis, blepharospasm). All new lenses studied reduced UV-radiation to a safe level, whereas used lenses did not maintain their transmittance characteristics. No positive effect of UV-blocking contact lenses could be proven with the study design used. © 2011 American College of Veterinary Ophthalmologists.

Amphiphilic block copolymers for drug delivery.

Science.gov (United States)

Adams, Monica L; Lavasanifar, Afsaneh; Kwon, Glen S

2003-07-01

Amphiphilic block copolymers (ABCs) have been used extensively in pharmaceutical applications ranging from sustained-release technologies to gene delivery. The utility of ABCs for delivery of therapeutic agents results from their unique chemical composition, which is characterized by a hydrophilic block that is chemically tethered to a hydrophobic block. In aqueous solution, polymeric micelles are formed via the association of ABCs into nanoscopic core/shell structures at or above the critical micelle concentration. Upon micellization, the hydrophobic core regions serve as reservoirs for hydrophobic drugs, which may be loaded by chemical, physical, or electrostatic means, depending on the specific functionalities of the core-forming block and the solubilizate. Although the Pluronics, composed of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide), are the most widely studied ABC system, copolymers containing poly(L-amino acid) and poly(ester) hydrophobic blocks have also shown great promise in delivery applications. Because each ABC has unique advantages with respect to drug delivery, it may be possible to choose appropriate block copolymers for specific purposes, such as prolonging circulation time, introduction of targeting moieties, and modification of the drug-release profile. ABCs have been used for numerous pharmaceutical applications including drug solubilization/stabilization, alteration of the pharmacokinetic profile of encapsulated substances, and suppression of multidrug resistance. The purpose of this minireview is to provide a concise, yet detailed, introduction to the use of ABCs and polymeric micelles as delivery agents as well as to highlight current and past work in this area. Copyright 2003 Wiley-Liss, Inc. and the American Pharmacists Association

A Trigonometrically Fitted Block Method for Solving Oscillatory Second-Order Initial Value Problems and Hamiltonian Systems

Directory of Open Access Journals (Sweden)

F. F. Ngwane

2017-01-01

Full Text Available In this paper, we present a block hybrid trigonometrically fitted Runge-Kutta-Nyström method (BHTRKNM, whose coefficients are functions of the frequency and the step-size for directly solving general second-order initial value problems (IVPs, including Hamiltonian systems such as the energy conserving equations and systems arising from the semidiscretization of partial differential equations (PDEs. Four discrete hybrid formulas used to formulate the BHTRKNM are provided by a continuous one-step hybrid trigonometrically fitted method with an off-grid point. We implement BHTRKNM in a block-by-block fashion; in this way, the method does not suffer from the disadvantages of requiring starting values and predictors which are inherent in predictor-corrector methods. The stability property of the BHTRKNM is discussed and the performance of the method is demonstrated on some numerical examples to show accuracy and efficiency advantages.

CMOS continuous-time adaptive equalizers for high-speed serial links

CERN Document Server

Gimeno Gasca, Cecilia; Aldea Chagoyen, Concepción

2015-01-01

This book introduces readers to the design of adaptive equalization solutions integrated in standard CMOS technology for high-speed serial links. Since continuous-time equalizers offer various advantages as an alternative to discrete-time equalizers at multi-gigabit rates, this book provides a detailed description of continuous-time adaptive equalizers design - both at transistor and system levels-, their main characteristics and performances. The authors begin with a complete review and analysis of the state of the art of equalizers for wireline applications, describing why they are necessary, their types, and their main applications. Next, theoretical fundamentals of continuous-time adaptive equalizers are explored. Then, new structures are proposed to implement the different building blocks of the adaptive equalizer: line equalizer, loop-filters, power comparator, etc.  The authors demonstrate the design of a complete low-power, low-voltage, high-speed, continuous-time adaptive equalizer. Finally, a cost-...

Which Ultrasound-Guided Sciatic Nerve Block Strategy Works Faster? Prebifurcation or Separate Tibial-Peroneal Nerve Block? A Randomized Clinical Trial.

Science.gov (United States)

Faiz, Seyed Hamid Reza; Imani, Farnad; Rahimzadeh, Poupak; Alebouyeh, Mahmoud Reza; Entezary, Saeed Reza; Shafeinia, Amineh

2017-08-01

Peripheral nerve block is an accepted method in lower limb surgeries regarding its convenience and good tolerance by the patients. Quick performance and fast sensory and motor block are highly demanded in this method. The aim of the present study was to compare 2 different methods of sciatic and tibial-peroneal nerve block in lower limb surgeries in terms of block onset. In this clinical trial, 52 candidates for elective lower limb surgery were randomly divided into 2 groups: sciatic nerve block before bifurcation (SG; n = 27) and separate tibial-peroneal nerve block (TPG; n = 25) under ultrasound plus nerve stimulator guidance. The mean duration of block performance, as well as complete sensory and motor block, was recorded and compared between the groups. The mean duration of complete sensory block in the SG and TPG groups was 35.4 ± 4.1 and 24.9 ± 4.2 minutes, respectively, which was significantly lower in the TPG group (P = 0.001). The mean duration of complete motor block in the SG and TPG groups was 63.3 ± 4.4 and 48.4 ± 4.6 minutes, respectively, which was significantly lower in the TPG group (P = 0.001). No nerve injuries, paresthesia, or other possible side effects were reported in patients. According to the present study, it seems that TPG shows a faster sensory and motor block than SG.

Harmony of spinning conformal blocks

Energy Technology Data Exchange (ETDEWEB)

Schomerus, Volker [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Sobko, Evgeny [Stockholm Univ. (Sweden); Nordita, Stockholm (Sweden); Isachenkov, Mikhail [Weizmann Institute of Science, Rehovoth (Israel). Dept. of Particle Physics and Astrophysics

2016-12-07

Conformal blocks for correlation functions of tensor operators play an increasingly important role for the conformal bootstrap programme. We develop a universal approach to such spinning blocks through the harmonic analysis of certain bundles over a coset of the conformal group. The resulting Casimir equations are given by a matrix version of the Calogero-Sutherland Hamiltonian that describes the scattering of interacting spinning particles in a 1-dimensional external potential. The approach is illustrated in several examples including fermionic seed blocks in 3D CFT where they take a very simple form.

PEO-related block copolymer surfactants

DEFF Research Database (Denmark)

Mortensen, K.

2001-01-01

Non-ionic block copolymer systems based on hydrophilic poly(ethylene oxide) and more hydrophobic co-polymer blocks are used intensively in a variety of industrial and personal applications. A brief description on the applications is presented. The physical properties of more simple model systems...... of such PEG-based block copolymers in aqueous suspensions are reviewed. Based on scattering experiments using either X-ray or neutrons, the phase behavior is characterized, showing that the thermo-reversible gelation is a result of micellar ordering into mesoscopic crystalline phases of cubic, hexagonal...

Harmony of spinning conformal blocks

Energy Technology Data Exchange (ETDEWEB)

Schomerus, Volker [DESY Hamburg, Theory Group,Notkestraße 85, 22607 Hamburg (Germany); Sobko, Evgeny [Nordita and Stockholm University,Roslagstullsbacken 23, SE-106 91 Stockholm (Sweden); Isachenkov, Mikhail [Department of Particle Physics and Astrophysics, Weizmann Institute of Science,Rehovot 7610001 (Israel)

2017-03-15

Conformal blocks for correlation functions of tensor operators play an increasingly important role for the conformal bootstrap programme. We develop a universal approach to such spinning blocks through the harmonic analysis of certain bundles over a coset of the conformal group. The resulting Casimir equations are given by a matrix version of the Calogero-Sutherland Hamiltonian that describes the scattering of interacting spinning particles in a 1-dimensional external potential. The approach is illustrated in several examples including fermionic seed blocks in 3D CFT where they take a very simple form.

Metallo-supramolecular block copolymer micelles

NARCIS (Netherlands)

Gohy, J.M.W.

2009-01-01

Supramolecular copolymers have become of increasing interest in recent years in the search for new materials with tunable properties. In particular, metallo-supramolecular block copolymers in which metal-ligand complexes are introduced in block copolymer architectures, have known important progress,

Inferior alveolar nerve block: Alternative technique.

Science.gov (United States)

Thangavelu, K; Kannan, R; Kumar, N Senthil

2012-01-01

Inferior alveolar nerve block (IANB) is a technique of dental anesthesia, used to produce anesthesia of the mandibular teeth, gingivae of the mandible and lower lip. The conventional IANB is the most commonly used the nerve block technique for achieving local anesthesia for mandibular surgical procedures. In certain cases, however, this nerve block fails, even when performed by the most experienced clinician. Therefore, it would be advantageous to find an alternative simple technique. The objective of this study is to find an alternative inferior alveolar nerve block that has a higher success rate than other routine techniques. To this purpose, a simple painless inferior alveolar nerve block was designed to anesthetize the inferior alveolar nerve. This study was conducted in Oral surgery department of Vinayaka Mission's dental college Salem from May 2009 to May 2011. Five hundred patients between the age of 20 years and 65 years who required extraction of teeth in mandible were included in the study. Out of 500 patients 270 were males and 230 were females. The effectiveness of the IANB was evaluated by using a sharp dental explorer in the regions innervated by the inferior alveolar, lingual, and buccal nerves after 3, 5, and 7 min, respectively. This study concludes that inferior alveolar nerve block is an appropriate alternative nerve block to anesthetize inferior alveolar nerve due to its several advantages.

Diaphragm-Sparing Nerve Blocks for Shoulder Surgery.

Science.gov (United States)

Tran, De Q H; Elgueta, Maria Francisca; Aliste, Julian; Finlayson, Roderick J

Shoulder surgery can result in significant postoperative pain. Interscalene brachial plexus blocks (ISBs) constitute the current criterion standard for analgesia but may be contraindicated in patients with pulmonary pathology due to the inherent risk of phrenic nerve block and symptomatic hemidiaphragmatic paralysis. Although ultrasound-guided ISB with small volumes (5 mL), dilute local anesthetic (LA) concentrations, and LA injection 4 mm lateral to the brachial plexus have been shown to reduce the risk of phrenic nerve block, no single intervention can decrease its incidence below 20%. Ultrasound-guided supraclavicular blocks with LA injection posterolateral to the brachial plexus may anesthetize the shoulder without incidental diaphragmatic dysfunction, but further confirmatory trials are required. Ultrasound-guided C7 root blocks also seem to offer an attractive, diaphragm-sparing alternative to ISB. However, additional large-scale studies are needed to confirm their efficacy and to quantify the risk of periforaminal vascular breach. Combined axillary-suprascapular nerve blocks may provide adequate postoperative analgesia for minor shoulder surgery but do not compare favorably to ISB for major surgical procedures. One intriguing solution lies in the combined use of infraclavicular brachial plexus blocks and suprascapular nerve blocks. Theoretically, the infraclavicular approach targets the posterior and lateral cords, thus anesthetizing the axillary nerve (which supplies the anterior and posterior shoulder joint), as well as the subscapular and lateral pectoral nerves (both of which supply the anterior shoulder joint), whereas the suprascapular nerve block anesthetizes the posterior shoulder. Future randomized trials are required to validate the efficacy of combined infraclavicular-suprascapular blocks for shoulder surgery.

Brief reports: a clinical evaluation of block characteristics using one milliliter 2% lidocaine in ultrasound-guided axillary brachial plexus block.

LENUS (Irish Health Repository)

O'Donnell, Brian

2010-09-01

We report onset and duration of ultrasound-guided axillary brachial plexus block using 1 mL of 2% lidocaine with 1:200,000 epinephrine per nerve (total local anesthetic volume 4 mL). Block performance time, block onset time, duration of surgery, and block duration were measured. Seventeen consecutive patients were recruited. The mean (SD) block performance and onset times were 271 (67.9) seconds and 9.7 (3.7) minutes, respectively. Block duration was 160.8 (30.7) minutes. All operations were performed using regional anesthesia alone. The duration of anesthesia obtained is sufficient for most ambulatory hand surgery.

ALS insertion device block measurement and inspection

International Nuclear Information System (INIS)

Marks, S.; Carrieri, J.; Cook, C.; Hassenzahl, W.V.; Hoyer, E.; Plate, D.

1991-05-01

The performance specifications for ALS insertion devices require detailed knowledge and strict control of the Nd-Fe-B permanent magnet blocks incorporated in these devices. This paper describes the measurement and inspection apparatus and the procedures designed to qualify and characterize these blocks. A detailed description of a new, automated Helmholtz coil facility for measurement of the three components of magnetic moment is included. Physical block inspection and magnetic moment measurement procedures are described. Together they provide a basis for qualifying blocks and for specifying placement of blocks within an insertion devices' magnetic structures. 1 ref., 4 figs

Ultrasound-guided block of the axillary nerve

DEFF Research Database (Denmark)

Rothe, C; Lund, J; Jenstrup, M T

2012-01-01

The specific blocking of the axillary nerve has never been investigated clinically. We present four cases illustrating potential applications of the axillary nerve block in the perioperative setting and discuss possible directions for future research in this area. The axillary nerve blocks were all...... performed using a newly developed in-plane ultrasound-guided technique. In one patient undergoing arthroscopic shoulder surgery, we used the axillary nerve block as the only analgesic combined with propofol sedation and spontaneous breathing. Chronic shoulder pain was eliminated after the axillary nerve...... block in two patients. The pain score after arthroscopic shoulder surgery in these two patients remained low until termination of the nerve block. In a fourth patient, severe post-operative pain after osteosynthesis of a displaced proximal humerus fracture was almost eliminated after performing...

Nonaqueous Dispersion Formed by an Emulsion Solvent Evaporation Method Using Block-Random Copolymer Surfactant Synthesized by RAFT Polymerization.

Science.gov (United States)

Ezaki, Naofumi; Watanabe, Yoshifumi; Mori, Hideharu

2015-10-27

As surfactants for preparation of nonaqueous microcapsule dispersions by the emulsion solvent evaporation method, three copolymers composed of stearyl methacrylate (SMA) and glycidyl methacrylate (GMA) with different monomer sequences (i.e., random, block, and block-random) were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. Despite having the same comonomer composition, the copolymers exhibited different functionality as surfactants for creating emulsions with respective dispersed and continuous phases consisting of methanol and isoparaffin solvent. The optimal monomer sequence for the surfactant was determined based on the droplet sizes and the stabilities of the emulsions created using these copolymers. The block-random copolymer led to an emulsion with better stability than obtained using the random copolymer and a smaller droplet size than achieved with the block copolymer. Modification of the epoxy group of the GMA unit by diethanolamine (DEA) further decreased the droplet size, leading to higher stability of the emulsion. The DEA-modified block-random copolymer gave rise to nonaqueous microcapsule dispersions after evaporation of methanol from the emulsions containing colored dyes in their dispersed phases. These dispersions exhibited high stability, and the particle sizes were small enough for application to the inkjet printing process.

Reversible conduction block in peripheral nerve using electrical waveforms.

Science.gov (United States)

Bhadra, Niloy; Vrabec, Tina L; Bhadra, Narendra; Kilgore, Kevin L

2018-01-01

Electrical nerve block uses electrical waveforms to block action potential propagation. Two key features that distinguish electrical nerve block from other nonelectrical means of nerve block: block occurs instantly, typically within 1 s; and block is fully and rapidly reversible (within seconds). Approaches for achieving electrical nerve block are reviewed, including kilohertz frequency alternating current and charge-balanced polarizing current. We conclude with a discussion of the future directions of electrical nerve block. Electrical nerve block is an emerging technique that has many significant advantages over other methods of nerve block. This field is still in its infancy, but a significant expansion in the clinical application of this technique is expected in the coming years.

Morphology-properties relationship on nanocomposite films based on poly(styrene-block-diene-block-styrene copolymers and silver nanoparticles

Directory of Open Access Journals (Sweden)

2011-02-01

Full Text Available A comparative study on the self-assembled nanostructured morphology and the rheological and mechanical properties of four different triblock copolymers, based on poly(styrene-block-diene-block-styrene and poly(styrene-block-diene-block-styrene matrices, and of their respective nanocomposites with 1 wt% silver nanoparticles, is reported in this work. In order to obtain well-dispersed nanoparticles in the block copolymer matrix, dodecanethiol was used as surfactant, showing good affinity with both nanoparticles and the polystyrene phase of the matrices as predicted by the solubility parameters calculated based on Hoftyzer and Van Krevelen theory. The block copolymer with the highest PS content shows the highest tensile modulus and tensile strength, but also the smallest elongation at break. When silver nanoparticles treated with surfactant were added to the block copolymer matrices, each system studied shows higher mechanical properties due to the good dispersion and the good interface of Ag nanoparticles in the matrices. Furthermore, it has been shown that semiempirical models such as Guth and Gold equation and Halpin-Tsai model can be used to predict the tensile modulus of the analyzed nanocomposites.

Palatability and efficacy of bromadiolone rodenticide block bait previously exposed to environmental conditions.

Science.gov (United States)

Nakagawa, Lia; de Masi, Eduardo; Narciso, Emerson; Neto, Hildebrando Montenegro; Papini, Solange

2015-10-01

In São Paulo city, rodent infestation is considered to be a serious public health problem and is the object of a municipal rodent control programme. One of the most important routine methods involves baiting in sewers, using bromadiolone block bait in a pulsed baiting strategy. It has been observed that, after each pulse, bait is not always consumed, and its appearance is altered, which has led to concerns about efficacy. We assessed whether exposure to sewer conditions influences the palatability and efficacy of rodenticide baits to Norway rats (Rattus norvegicus). Baits containing bromadiolone as active ingredient were placed in sewers, removed after 30 days and offered to rats in a two-choice food trial and a no-choice food trial. The appearance of the rodenticide baits changed after 30 days exposure to sewer conditions, but they continued to be palatable and effective against rats. The level of mortality was considered to be satisfactory, 75% in the two-choice food trial and 100% in the no-choice food trial. Results support the reuse of rodenticide block bait in rodent control. It seems to be justified to continue using/reuse baits even when their appearance has changed after 30 days exposure in sewer systems. © 2014 Society of Chemical Industry.

Blocking in Category Learning

OpenAIRE

Bott, Lewis; Hoffman, Aaron B.; Murphy, Gregory L.

2007-01-01

Many theories of category learning assume that learning is driven by a need to minimize classification error. When there is no classification error, therefore, learning of individual features should be negligible. We tested this hypothesis by conducting three category learning experiments adapted from an associative learning blocking paradigm. Contrary to an error-driven account of learning, participants learned a wide range of information when they learned about categories, and blocking effe...

The barrier to misfit dislocation glide in continuous, strained, epitaxial layers on patterned substrates

International Nuclear Information System (INIS)

Watson, G.P.; Ast, D.G.; Anderson, T.J.; Pathangey, B.

1993-01-01

In a previous report [G. P. Watson, D. G. Ast, T. J. Anderson, and Y. Hayakawa, Appl. Phys. Lett. 58, 2517 (1991)] we demonstrated that the motion of misfit dislocations in InGaAs, grown by organometallic vapor phase epitaxy on patterned GaAs substrates, can be impeded even if the strained epitaxial layer is continuous. Trenches etched into GaAs before growth are known to act as a barrier to misfit dislocation propagation [E. A. Fitzgerald, G. P. Watson, R. E. Proano, D. G. Ast, P. D. Kirchner, G. D. Pettit, and J. M. Woodall, J. Appl. Phys. 65, 2220 (1989)] when those trenches create discontinuities in the epitaxial layers; but even shallow trenches, with continuous strained layers following the surface features, can act as barriers. By considering the strain energy required to change the length of the dislocation glide segments that stretch from the interface to the free surface, a simple model is developed that explains the major features of the unique blocking action observed at the trench edges. The trench wall angle is found to be an important parameter in determining whether or not a trench will block dislocation glide. The predicted blocking angles are consistent with observations made on continuous 300 and 600 nm thick In 0.04 Ga 0.96 As films on patterned GaAs. Based on the model, a structure is proposed that may be used as a filter to yield misfit dislocations with identical Burgers vectors or dislocations which slip in only one glide plane

Enhanced recovery pathways in thoracic surgery from Italian VATS Group: perioperative analgesia protocols.

Science.gov (United States)

Piccioni, Federico; Segat, Matteo; Falini, Stefano; Umari, Marzia; Putina, Olga; Cavaliere, Lucio; Ragazzi, Riccardo; Massullo, Domenico; Taurchini, Marco; Del Naja, Carlo; Droghetti, Andrea

2018-03-01

Video-assisted thoracoscopic surgery (VATS) is a minimally invasive technique that allows a faster recovery after thoracic surgery. Although enhanced recovery after surgery (ERAS) principles seem reasonably applicable to thoracic surgery, there is little literature on the application of such a strategy in this context. In regard to pain management, ERAS pathways promote the adoption of a multimodal strategy, tailored to the patients. This approach is based on combining systemic and loco-regional analgesia to favour opioid-sparing strategies. Thoracic paravertebral block is considered the first-line loco-regional technique for VATS. Other techniques include intercostal nerve block and serratus anterior plane block. Nonsteroidal anti-inflammatory drugs and paracetamol are essential part of the multimodal treatment of pain. Also, adjuvant drugs can be useful as opioid-sparing agents. Nevertheless, the treatment of postoperative pain must take into account opioid agents too, if necessary. All above is useful for careful planning and execution of a multimodal analgesic treatment to enhance the recovery of patients. This article summarizes the most recent evidences from literature and authors' experiences on perioperative multimodal analgesia principles for implementing an ERAS program after VATS lobectomy.

Coupled deformation and fluid-flow behavior of a natural fracture in the CSM in situ test block

International Nuclear Information System (INIS)

Gertsch, L.S.

1989-01-01

The primary goal was the evaluation of an in situ block test as a data source for modeling the coupled flow and mechanical behavior of natural rock fractures. The experiments were conducted with the Colorado School of Mines in situ test block, an 8 m 3 (280 ft 3 ) gneiss cube which has been the focus of several previous studies. A single continuous fracture within the block was surrounded with instruments to measure stresses, deformations, and gas conductivity. The setup was subjected to combinations of normal and shear stress by pressurizing the block sides differentially with hydraulic flatjacks. The induced fracture deformation, as measured by two separate sensor systems, did not correlate closely with the fracture conductivity changes or with each other. The test fracture is more complicated physically than two parallel rock faces. Many joints which were not detected by mapping intersect the test fracture and strongly influence its behavior. These invisible joints create sub-blocks which react complexly to changes in applied load. The flow tests reflected the aggregate sub-block dislocations in the flow path. The deformation readings, however, were the movements of discrete points sparsely located among the sub-blocks. High-confidence extrapolation of block test results to large volumes, such as required for nuclear waste repository design, is not feasible currently. Present instrumentation does not sample rock mass behavior in situ at the proper scales. More basically, however, a fundamental gap exists between the nature of jointed rock and our conception of it. Therefore, the near-field rock mass must be discounted as an easily controllable barrier to groundwater flow, until radically different approaches to rock mass testing and modeling are developed

MRI of lumbar trunk muscles in patients with Parkinson's disease and camptocormia.

Science.gov (United States)

Margraf, N G; Rohr, A; Granert, O; Hampel, J; Drews, A; Deuschl, G

2015-07-01

Camptocormia in Parkinson's disease (PD) is an axial postural disorder usually accompanied by histopathological changes in the paravertebral muscles of unknown etiology. The diagnostic potential of magnetic resonance imaging (MRI) of back muscles in camptocormia has not been systematically assessed. Our objective was to characterize pathological muscle changes with MRI and to develop radiological criteria for camptocormia. The criteria edema, swelling and fatty degeneration in 20 idiopathic PD patients with camptocormia were assessed using MRI (T1w and short tau inversion recovery (STIR) sequences) of the lumbar trunk muscles and compared with 20 group-matched PD patients without camptocormia. Edema and fatty degeneration of the paravertebral muscles were significantly more frequent in camptocormia. Edema correlated negatively and fatty degeneration positively with the duration of camptocormia and not PD. Swelling of the paravertebral muscles, edema and swelling of the quadratus lumborum muscle and rare edema of the psoas muscle were only found in camptocormia patients. In this case-control study the defined MRI criteria distinguish the group of PD patients with camptocormia versus those without. Our findings suggest dynamic changes in the MRI signals over time in the paravertebral muscles: edema and swelling are found initially, followed by fatty atrophic degeneration 2-3 years after the beginning of camptocormia. Muscle MRI qualifies as a tool for categorizing phases of camptocormia as acute or chronic, with potential consequences for therapeutic approaches. The involvement of muscles beyond an isolated impairment of the paravertebral muscles implies a more systemic view with a deregulation of lumbar trunk muscles.

[Complete atrioventricular block in Duchenne muscular dystrophy].

Science.gov (United States)

Kuru, Satoshi; Tanahashi, Tamotsu; Matsumoto, Shinjirou; Kitamura, Tetsuya; Konagaya, Masaaki

2012-01-01

We report a case of complete atrioventricular (AV) block in a 40-year-old patient with Duchenne muscular dystrophy (DMD). While he was bed-ridden and required mechanical ventilation, his cardiac involvement was mild. He had the deletion of exon 45-52 in the dystrophin gene. He underwent transient complete AV block and came to require pacemaker implantation due to recurrence of complete AV block ten days after the first attack. Electrophysiological study revealed mild prolonged AH and HV interval. Although DMD patients with AV block have been rarely reported so far, attention should be paid to AV block for patients who prolonged their lives.

Emulsion Solvent Evaporation-Induced Self-Assembly of Block Copolymers Containing pH-Sensitive Block.

Science.gov (United States)

Wu, Yuqing; Wang, Ke; Tan, Haiying; Xu, Jiangping; Zhu, Jintao

2017-09-26

A simple yet efficient method is developed to manipulate the self-assembly of pH-sensitive block copolymers (BCPs) confined in emulsion droplets. Addition of acid induces significant variation in morphological transition (e.g., structure and surface composition changes) of the polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) assemblies, due to the hydrophobic-hydrophilic transition of the pH-sensitive P4VP block via protonation. In the case of pH > pKa (P4VP) (pKa (P4VP) = 4.8), the BCPs can self-assemble into pupa-like particles because of the nearly neutral wetting of PS and P4VP blocks at the oil/water interface. As expected, onion-like particles obtained when pH is slightly lower than pKa (P4VP) (e.g., pH = 3.00), due to the interfacial affinity to the weakly hydrophilic P4VP block. Interestingly, when pH was further decreased to ∼2.5, interfacial instability of the emulsion droplets was observed, and each emulsion droplet generated nanoscale assemblies including vesicles, worm-like and/or spherical micelles rather than a nanostructured microparticle. Furthermore, homopolymer with different molecular weights and addition ratio are employed to adjust the interactions among copolymer blocks. By this means, particles with hierarchical structures can be obtained. Moreover, owing to the kinetically controlled processing, we found that temperature and stirring speed, which can significantly affect the kinetics of the evaporation of organic solvent and the formation of particles, played a key role in the morphology of the assemblies. We believe that manipulation of the property for the aqueous phase is a promising strategy to rationally design and fabricate polymeric assemblies with desirable shapes and internal structures.

[Postoperative analgesia in knee arthroplasty using an anterior sciatic nerve block and a femoral nerve block].

Science.gov (United States)

del Fresno Cañiaveras, J; Campos, A; Galiana, M; Navarro-Martínez, J A; Company, R

2008-11-01

To evaluate the efficacy of a nerve block as an alternative technique for analgesia after knee arthroplasty and to indicate the usefulness and advantages of the anterior approach to the sciatic nerve block. Between April 2004 and March 2006, we studied a series of consecutive patients undergoing knee arthroplasty in which a subarachnoid block was used as the anesthetic technique and postoperative analgesia was provided by means of a combined peripheral femoral nerve block and an anterior sciatic nerve block. We evaluated the mean length of time free from pain, quality of analgesia, and length of stay in hospital. Seventy-eight patients were included in the study. The mean (SD) length of time free from pain for the group was 42.1 (3.9) hours. Patients reported mild pain after 34.8 (4.1) hours and moderate to severe pain after 42.4 (3.5) hours. By the third day, 62.8% of patients were able to bend the knee to 90 degrees. There were no complications resulting from the technique and the level of patient satisfaction was high. A combined femoral-sciatic nerve block is effective in knee arthroplasty. It controls postoperative pain and allows for early rehabilitation. The anterior approach to the sciatic nerve is relatively simple to perform without removing the pressure bandaging from the thigh after surgery. This approach also makes it unnecessary to move the patient.

Ultrasound Guided Transversus Thoracic Plane block, Parasternal block and fascial planes hydrodissection for internal mammary post thoracotomy pain syndrome.

Science.gov (United States)

Piraccini, E; Biondi, G; Byrne, H; Calli, M; Bellantonio, D; Musetti, G; Maitan, S

2018-05-16

Pectoral Nerves Block (PECS) and Serratus Plane Block (SPB) have been used to treat persistent post-surgical pain after breast and thoracic surgery; however, they cannot block the internal mammary region, so a residual pain may occur in that region. Parasternal block (PSB) and Thoracic Transversus Plane Block (TTP) anaesthetize the anterior branches of T2-6 intercostal nerves thus they can provide analgesia to the internal mammary region. We describe a 60-year-old man suffering from right post-thoracotomy pain syndrome with residual pain located in the internal mammary region after a successful treatment with PECS and SPB. We performed a PSB and TTP and hydrodissection of fascial planes with triamcinolone and Ropivacaine. Pain disappeared and the result was maintained 3 months later. This report suggests that PSB and TTP with local anaesthetic and corticosteroid with hydrodissection of fascial planes might be useful to treat a post thoracotomy pain syndrome located in the internal mammary region. The use of Transversus Thoracic Plane and Parasternal Blocks and fascial planes hydrodissection as a novel therapeutic approach to treat a residual post thoracotomy pain syndrome even when already treated with Pectoral Nerves Block and Serratus Plane Block. © 2018 European Pain Federation - EFIC®.

Post-cracking behavior of blocks, prisms, and small concrete walls reinforced with plant fiber

Directory of Open Access Journals (Sweden)

I. I. Soto

Full Text Available Structural masonry using concrete blocks promotes the rationalization of construction projects, lowering the final cost of a building through the elimination of forms and the reduction of the consumption of reinforcement bars. Moreover, production of a block containing a combination of concrete and vegetable fiber sisal results in a unit with properties such as mechanical strength, stiffness, flexibility, ability to absorb energy, and post-cracking behavior that are comparable to those of a block produced with plain concrete. Herein are reported the results of a study on the post-cracking behavior of blocks, prisms, and small walls reinforced with sisal fibers (lengths of 20 mm and 40 mm added at volume fractions of 0.5% and 1%. Tests were performed to characterize the fibers and blocks and to determine the compressive strength of the units, prisms, and small walls. The deformation modulus of the elements was calculated and the stress-strain curves were plotted to gain a better understanding of the values obtained. The compression test results for the small walls reinforced with fibers were similar to those of the reference walls and better than the blocks and prisms with added fibers, which had resistances lower than those of the corresponding conventional materials. All elements prepared with the addition of sisal exhibited an increase in the deformation capacity (conferred by the fibers, which was observed in the stress-strain curves. The failure mode of the reference elements was characterized by an abrupt fracture, whereas the reinforced elements underwent ductile breakage. This result was because of the presence of the fibers, which remained attached to the faces of the cracks via adhesion to the cement matrix, thus preventing loss of continuity in the material. Therefore, the cement/plant fiber composites are advantageous in terms of their ductility and ability to resist further damage after cracking.

Anthropogenic Changes in Mid-latitude Storm and Blocking Activities from Observations and Climate Models

Science.gov (United States)

Li, D.

2017-12-01

blocking activities in the case of continued anthropogenic CO2 forcing.

Readiness for surgery after axillary block

DEFF Research Database (Denmark)

Koscielniak-Nielsen, Z J; Stens-Pedersen, H L; Lippert, F K

1997-01-01

required less time for block performance (mean 5.5 min) than multiple injections (mean 9.5 min), P requirement for supplemental nerve blocks was greater, after single injections (33 min and 57%) than after multiple injections (15.5 min and 7......We have assessed prospectively the time to readiness for surgery following axillary block (sum of block performance and latency times) in 80 patients. The brachial plexus was identified using a nerve stimulator, and anaesthetized with 45 mL of mepivacaine 1% with adrenaline 5 micrograms mL-1......%, respectively), P effectiveness was 100% in group 1 and 98% in group 2 (NS). The frequency of adverse effects (vessel puncture or paraesthesia) was similar...

Writing Blocks and Tacit Knowledge.

Science.gov (United States)

Boice, Robert

1993-01-01

A review of the literature on writing block looks at two kinds: inability to write in a timely, fluent fashion, and reluctance by academicians to assist others in writing. Obstacles to fluent writing are outlined, four historical trends in treating blocks are discussed, and implications are examined. (MSE)

A Retrospective Study Evaluating the Effect of Low Doses of Perineural Dexamethasone on Ropivacaine Brachial Plexus Peripheral Nerve Block Analgesic Duration.

Science.gov (United States)

Schnepper, Gregory D; Kightlinger, Benjamin I; Jiang, Yunyun; Wolf, Bethany J; Bolin, Eric D; Wilson, Sylvia H

2017-09-23

Examination of the effectiveness of perineural dexamethasone administered in very low and low doses on ropivacaine brachial plexus block duration. Retrospective evaluation of brachial plexus block duration in a large cohort of patients receiving peripheral nerve blocks with and without perineural dexamethasone in a prospectively collected quality assurance database. A single academic medical center. A total of 1,942 brachial plexus blocks placed over a 16-month period were reviewed. Demographics, nerve block location, and perineural dexamethasone utilization and dose were examined in relation to block duration. Perineural dexamethasone was examined as none (0 mg), very low dose (2 mg or less), and low dose (greater than 2 mg to 4 mg). Continuous catheter techniques, local anesthetics other than ropivacaine, and block locations with fewer than 15 subjects were excluded. Associations between block duration and predictors of interest were examined using multivariable regression models. A subgroup analysis of the impact of receiving dexamethasone on block duration within each block type was also conducted using a univariate linear regression approach. A total of 1,027 subjects were evaluated. More than 90% of brachial plexus blocks contained perineural dexamethasone (≤4 mg), with a median dose of 2 mg. Increased block duration was associated with receiving any dose of perineural dexamethasone (P block duration did not differ with very low- or low-dose perineural dexamethasone after controlling for other factors (P = 0.420). Perineural dexamethasone prolonged block duration compared with ropivacaine alone; however, duration was not greater with low-dose compared with very low-dose perineural dexamethasone. © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Polybenzimidazole block copolymers for fuel cell: synthesis and studies of block length effects on nanophase separation, mechanical properties, and proton conductivity of PEM.

Science.gov (United States)

Maity, Sudhangshu; Jana, Tushar

2014-05-14

A series of meta-polybenzimidazole-block-para-polybenzimidazole (m-PBI-b-p-PBI), segmented block copolymers of PBI, were synthesized with various structural motifs and block lengths by condensing the diamine terminated meta-PBI (m-PBI-Am) and acid terminated para-PBI (p-PBI-Ac) oligomers. NMR studies and existence of two distinct glass transition temperatures (Tg), obtained from dynamical mechanical analysis (DMA) results, unequivocally confirmed the formation of block copolymer structure through the current polymerization methodology. Appropriate and careful selection of oligomers chain length enabled us to tailor the block length of block copolymers and also to make varieties of structural motifs. Increasingly distinct Tg peaks with higher block length of segmented block structure attributed the decrease in phase mixing between the meta-PBI and para-PBI blocks, which in turn resulted into nanophase segregated domains. The proton conductivities of proton exchange membrane (PEM) developed from phosphoric acid (PA) doped block copolymer membranes were found to be increasing substantially with increasing block length of copolymers even though PA loading of these membranes did not alter appreciably with varying block length. For example when molecular weight (Mn) of blocks were increased from 1000 to 5500 then the proton conductivities at 160 °C of resulting copolymers increased from 0.05 to 0.11 S/cm. Higher block length induced nanophase separation between the blocks by creating less morphological barrier within the block which facilitated the movement of the proton in the block and hence resulting higher proton conductivity of the PEM. The structural varieties also influenced the phase separation and proton conductivity. In comparison to meta-para random copolymers reported earlier, the current meta-para segmented block copolymers were found to be more suitable for PBI-based PEM.

Natural convection in a horizontal channel provided with heat generating blocks: Discussion of the isothermal blocks validity

International Nuclear Information System (INIS)

Mouhtadi, D.; Amahmid, A.; Hasnaoui, M.; Bennacer, R.

2012-01-01

Highlights: ► We examine the validity of isothermal model for blocks with internal heat generation. ► Criteria based on comparison of total and local quantities are adopted. ► Thermal conductivity and Biot number required for the validity of the isothermal model are dependent on the Rayleigh number. ► The validity conditions are also affected by the multiplicity of solutions. - Abstract: This work presents a numerical study of air natural convection in a horizontal channel provided with heating blocks periodically distributed on its lower adiabatic surface. The blocks are submitted to a uniform heat generation and the channel upper surface is maintained at a cold constant temperature. The main objective of this study is to examine the validity of the model with isothermal blocks for the system under consideration. Then the calculations are performed using two different models. In the first (denoted Model 1 or M1) the calculations are performed by imposing a uniform volumetric heat generation inside the blocks. In the second model (denoted Model 2 or M2), the blocks are maintained isothermal at the average blocks surface temperature deduced from the Model 1. The controlling parameters of the present problem are the thermal conductivity ratio of the solid block and the fluid (0.1 ⩽ k* = k s /k a ⩽ 200) and the Rayleigh number (10 4 ⩽ Ra ⩽ 10 7 ). The validity of the isothermal model is examined for various Ra by using criteria based on local and mean heat transfer characteristics. It is found that some solutions of the isothermal model do not reproduce correctly the results of the first model even for very large conductivity ratios. The Biot number below which the Model 2 is valid depends strongly on the Rayleigh number and the type of solution.

Conformal Nets II: Conformal Blocks

Science.gov (United States)

Bartels, Arthur; Douglas, Christopher L.; Henriques, André

2017-08-01

Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

Inferior alveolar nerve block: Alternative technique

OpenAIRE

Thangavelu, K.; Kannan, R.; Kumar, N. Senthil

2012-01-01

Background: Inferior alveolar nerve block (IANB) is a technique of dental anesthesia, used to produce anesthesia of the mandibular teeth, gingivae of the mandible and lower lip. The conventional IANB is the most commonly used the nerve block technique for achieving local anesthesia for mandibular surgical procedures. In certain cases, however, this nerve block fails, even when performed by the most experienced clinician. Therefore, it would be advantageous to find an alternative simple techni...

Natural convective flows in a horizontal channel provided with heating isothermal blocks: Effect of the inter blocks spacing

International Nuclear Information System (INIS)

Bakkas, M.; Hasnaoui, M.; Amahmid, A.

2010-01-01

A numerical study of laminar steady natural convection induced in a two dimensional horizontal channel provided with rectangular heating blocks, periodically mounted on its lower wall, is carried out. The blocks' surface temperature, T H ' , is maintained constant and the former are connected with adiabatic surfaces. The upper wall of the channel is maintained cold at a temperature T C ' H ' . Fluid flow, temperature fields and heat transfer rates are presented for different combinations of the governing parameters which are the Rayleigh number (10 2 ≤Ra≤2x10 6 ), the blocks' spacing (1/4≤C=l ' /H ' ≤1), the blocks' height (1/8≤B=h ' /H ' ≤1/2) and the relative width of the blocks (A=(L ' -l ' )/H ' =1/2). The results obtained in the case of air (Pr = 0.72) show that the flow structure and the heat transfer are significantly influenced by the control parameters. It is found that there are situations where the increase of the blocks' spacing leads to a reduction of heat transfer.

MARINE BOTTOM COMMUNITIES OF BLOCK ISLAND WATERS

Science.gov (United States)

The sea has long been an integral part of Block Island's natural history, beginning when the rising sea surrounded the high spot on a Pleistocene terminal moraine that became Block Island. The southern New England continental shelf, which lies around Block Island, and the Great S...

Compaction of bentonite blocks. Development of technique for industrial production of blocks which are manageable by man

Energy Technology Data Exchange (ETDEWEB)

Johannesson, L E; Boergesson, L; Sanden, T [Clay Technology AB, Lund (Sweden)

1995-04-01

In this report a useful technique for producing compacted blocks of bentonite is described. The report only deals with the technique to produce uniaxially compacted blocks (weight of the blocks: 10-15 kg) which are manageable by man. Tests for producing blocks with a weight of approximately 10 kg were carried out at Hoeganaes Bjuf AB in Bjuf. This industry is normally producing refractory bricks and other refractory products. The plant has facilities for handling large volumes of clay. Furthermore there are machines suitable for producing uniaxially compacted blocks. Performed tests at the plant show that it is possible to compact blocks with good quality. Best quality was reached with a coarsely ground bentonite at a water ratio of 20 %. The compaction was performed with lubricated form and stepwise loading. The tests at Hoeganaes Bjuf AB were preceded by tests in the laboratory. In these tests smaller samples were compacted for studying how different factors affect the quality of the samples (density, water ratio, homogeneity et cetera). The influence of following factors was studied: water ratio of bentonite; bentonite type and granulometry; compaction pressure; compaction rate; form geometry; form lubrication; form heating. The results from these tests were used to modify and optimize the technique in the factory.

Electrocardiographic characteristics of atrioventricular block induced by tilt testing.

Science.gov (United States)

Zyśko, Dorota; Gajek, Jacek; Koźluk, Edward; Mazurek, Walentyna

2009-02-01

The electrocardiographic (ECG) characteristics of atrioventricular (AV) block during reflex syncope may be unique due to the presence of hypervagotonia. The aim of the present study was to define the ECG characteristics of the AV block induced by neurocardiogenic reflex provoked by tilt testing (TT). A series of 31 patients with presumed vasovagal syncope and AV block provoked by TT was studied. The duration of PP and PR interval, AV block grade and type, concomitant arrhythmias, and timing of the AV block occurrence were assessed. The AV block occurred at TT termination in 26 patients, in the recovery in 4 patients, and in both periods in 1 patient. Atrioventricular block was preceded by sinus slowing, and sinus rhythm during AV block was slow and instable. Mobitz I, 2:1 second-degree AV block, and advanced second-degree AV block were recognized in 35.5, 48.4, and 67.8% of patients, respectively. Third-degree AV block was diagnosed in 41.9% of patients. Twenty-one patients had at least two AV block forms. The most prevalent concomitant arrhythmia was junctional escape rhythm (61.3%). (i) The occurrence of the AV block during neurocardiogenic reaction induced by TT is always preceded by sinus rhythm slowing and usually by PR interval prolongation. (ii) The AV block provoked by TT usually occurs at TT termination, but may occur even in the recovery period in a supine position. Sometimes the AV block may be present both at TT termination and during the recovery period.

A multistep continuous-flow system for rapid on-demand synthesis of receptor ligands

DEFF Research Database (Denmark)

Petersen, Trine P; Ritzén, Andreas; Ulven, Trond

2009-01-01

A multistep continuous-flow system for synthesis of receptor ligands by assembly of three variable building blocks in a single unbroken flow is described. The sequence consists of three reactions and two scavenger steps, where a Cbz-protected diamine is reacted with an isocyanate, deprotected, an......, and reacted further with an alkylating agent....

30 CFR 250.511 - Traveling-block safety device.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Traveling-block safety device. 250.511 Section... Traveling-block safety device. All units being used for well-completion operations that have both a traveling block and a crown block must be equipped with a safety device that is designed to prevent the...

The undesirable effects of neuromuscular blocking drugs

DEFF Research Database (Denmark)

Claudius, C; Garvey, L H; Viby-Mogensen, J

2009-01-01

Neuromuscular blocking drugs are designed to bind to the nicotinic receptor at the neuromuscular junction. However, they also interact with other acetylcholine receptors in the body. Binding to these receptors causes adverse effects that vary with the specificity for the cholinergic receptor...... in question. Moreover, all neuromuscular blocking drugs may cause hypersensitivity reactions. Often the symptoms are mild and self-limiting but massive histamine release can cause systematic reactions with circulatory and respiratory symptoms and signs. At the end of anaesthesia, no residual effect...... of a neuromuscular blocking drug should be present. However, the huge variability in response to neuromuscular blocking drugs makes it impossible to predict which patient will suffer postoperative residual curarization. This article discusses the undesirable effects of the currently available neuromuscular blocking...

A Randomized Controlled Trial Examining the Effect of the Addition of the Mandibular Block to Cervical Plexus Block for Carotid Endarterectomy.

Science.gov (United States)

Kavrut Ozturk, Nilgun; Kavakli, Ali Sait; Sagdic, Kadir; Inanoglu, Kerem; Umot Ayoglu, Raif

2018-04-01

Although the cervical plexus block generally provides adequate analgesia for carotid endarterectomy, pain caused by metal retractors on the inferior surface of the mandible is not prevented by the cervical block. Different pain relief methods can be performed for patients who experience discomfort in these areas. In this study, the authors evaluated the effect of mandibular block in addition to cervical plexus block on pain scores in carotid endarterectomy. A prospective, randomized, controlled trial. Training and research hospital. Patients who underwent a carotid endarterectomy. Patients scheduled for carotid endarterectomy under cervical plexus block were randomized into 2 groups: group 1 (those who did not receive a mandibular block) and group 2 (those who received a mandibular block). The main purpose of the study was to evaluate the mandibular block in addition to cervical plexus block in terms of intraoperative pain scores. Intraoperative visual analog scale scores were significantly higher in group 1 (p = 0.001). The amounts of supplemental 1% lidocaine and intraoperative intravenous analgesic used were significantly higher in group 1 (p = 0.001 and p = 0.035, respectively). Patient satisfaction scores were significantly lower in group 1 (p = 0.044). The amount of postoperative analgesic used, time to first analgesic requirement, postoperative visual analog scale scores, and surgeon satisfaction scores were similar in both groups. There was no significant difference between the groups with respect to complications. No major neurologic deficits or perioperative mortality were observed. Mandibular block in addition to cervical plexus block provides better intraoperative pain control and greater patient satisfaction than cervical plexus block alone. Copyright © 2017 Elsevier Inc. All rights reserved.

[Conduction block: a notion to let through].

Science.gov (United States)

Fournier, E

2012-12-01

Historical study of electrodiagnosis indicates that nerve conduction block is an old notion, used as early as the second century by Galien and then early in the 19th by physiologists such as Müller and Mateucci. Although introduced into the field of human pathology by Mitchell in 1872, who used it to study nerve injuries, and then by Erb in 1874 to study radial palsy, the contribution of nerve conduction blocks to electrodiagnosis was not exploited until the 1980s. At that time, attempts to improve early diagnosis of Guillain-Barré syndrome showed that among the electrophysiological consequences of demyelination, conduction block was the most appropriate to account for the paralysis. At the same time, descriptions of neuropathies characterized by conduction blocks led to considering conduction block as a major electrophysiological sign. Why was it so difficult for this sign to be retained for electrodiagnosis? Since the notion is not always associated with anatomical lesions, it doesn't fit easily into anatomoclinical reasoning, but has to be thought of in functional terms. Understanding how an uninjured axon could fail to conduct action potentials leads to an examination of the intimate consequences of demyelinations and axonal dysfunctions. But some of the difficulty encountered in adding this new old sign to the armamentarium of electrophysiological diagnosis was related to the technical precautions required to individualize a block. Several pitfalls have to be avoided if a conduction block is to be afforded real diagnostic value. Similar precautions and discussions are also needed to establish an opposing sign, the "excitability block" or "inverse block". Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Block Copolymers: Synthesis and Applications in Nanotechnology

Science.gov (United States)

Lou, Qin

This study is focused on the synthesis and study of (block) copolymers using reversible deactivation radical polymerizations (RDRPs), including atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer (RAFT) polymerization. In particular, two primary areas of study are undertaken: (1) a proof-of-concept application of lithographic block copolymers, and (2) the mechanistic study of the deposition of titania into block copolymer templates for the production of well-ordered titania nanostructures. Block copolymers have the ability to undergo microphase separation, with an average size of each microphase ranging from tens to hundreds of nanometers. As such, block copolymers have been widely considered for nanotechnological applications over the past two decades. The development of materials for various nanotechnologies has become an increasingly studied area as improvements in many applications, such as those found in the semiconductor and photovoltaic industries are constantly being sought. Significant growth in developments of new synthetic methods ( i.e. RDRPs) has allowed the production of block copolymers with molecular (and sometimes atomic) definition. In turn, this has greatly expanded the use of block copolymers in nanotechnology. Herein, we describe the synthesis of statistical and block copolymers of 193 nm photolithography methacrylate and acrylate resist monomers with norbornyl and adamantyl moieties using RAFT polymerization.. For these resist (block) copolymers, the phase separation behaviors were examined by atomic force microscopy (AFM). End groups were removed from the polymers to avoid complications during the photolithography since RAFT end groups absorb visible light. Poly(glycidyl methacrylate-block-polystyrene) (PGMA-b-PS) was synthesize by ATRP and demonstrated that this block copolymer acts as both a lithographic UV (365 nm) photoresist and a self-assembly material. The PGMA segments can undergo cationic

Comparison of peri- and intraarticular analgesia with femoral nerve block after total knee arthroplasty: a randomized clinical trial

DEFF Research Database (Denmark)

Toftdahl, Karen; Nikolajsen, Lone; Haraldsted, Viggo

2007-01-01

to receive continuous femoral nerve block (group F) or peri- and intraarticular infiltration and injection (group I). Group I received a solution of 300 mg ropivacaine, 30 mg ketorolac, and 0.5 mg epinephrine by infiltration of the knee at the end of surgery, and 2 postoperative injections...

30 CFR 250.611 - Traveling-block safety device.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Traveling-block safety device. 250.611 Section... Traveling-block safety device. After May 31, 1989, all units being used for well-workover operations which have both a traveling block and a crown block shall be equipped with a safety device which is designed...

Brief Announcement: ZeroBlock: Timestamp-Free Prevention of Block-Withholding Attack in Bitcoin

OpenAIRE

Solat , Siamak; Potop-Butucaru , Maria

2017-01-01

International audience; Bitcoin was recently introduced as a peer-to-peer electronic currency in order to facilitate transactions outside the traditional financial system. The core of Bitcoin, the Blockchain, is the history of the transactions in the system maintained by all miners as a distributed shared register. New blocks in the Blockchain contain the last transactions in the system and are added by miners after a block mining process that consists in solving a resource consuming proof-of...

30 CFR 77.1505 - Auger holes; blocking.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Auger holes; blocking. 77.1505 Section 77.1505 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH... § 77.1505 Auger holes; blocking. Auger holes shall be blocked with highwall spoil or other suitable...

30 CFR 57.19079 - Blocking mine cars.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Blocking mine cars. 57.19079 Section 57.19079... Hoisting Procedures § 57.19079 Blocking mine cars. Where mine cars are hoisted by cage or skip, means for blocking cars shall be provided at all landings and also on the cage. ...

30 CFR 56.19079 - Blocking mine cars.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Blocking mine cars. 56.19079 Section 56.19079... Hoisting Procedures § 56.19079 Blocking mine cars. Where mine cars are hoisted by cage or skip, means for blocking cars shall be provided at all landings and also on the cage. ...

OPAL Various Lead Glass Blocks

CERN Multimedia

These lead glass blocks were part of a CERN detector called OPAL (one of the four experiments at the LEP particle detector). OPAL uses some 12 000 blocks of glass like this to measure particle energies in the electromagnetic calorimeter. This detector measured the energy deposited when electrons and photons were slowed down and stopped.

Steam-cured stabilised soil blocks for masonry construction

Energy Technology Data Exchange (ETDEWEB)

Venkatarama Reddy, B.V. [Indian Inst. of Science, Bangalore (India). Dept. of Civil Engineering; Lokras, S.S. [Indian Inst. of Science, Bangalore (India). ASTRA

1998-12-01

Energy-efficient, economical and durable building materials are essential for sustainable construction practices. The paper deals with production and properties of energy-efficient steam-cured stabilised soil blocks used for masonry construction. Problems of mixing expansive soil and lime, and production of blocks using soil-lime mixtures have been discussed briefly. Details of steam curing of stabilised soil blocks and properties of such blocks are given. A comparison of energy content of steam-cured soil blocks and burnt bricks is presented. It has been shown that energy-efficient steam cured soil blocks (consuming 35% less thermal energy compared to burnt clay bricks) having high compressive strength can be easily produced in a decentralised manner. (orig.)

A Lack of Continuity in Education, Training, and Practice Violates the "Do No Harm" Principle.

Science.gov (United States)

Englander, Robert; Carraccio, Carol

2018-03-01

The paradigm shift to competency-based medical education (CBME) is under way, but incomplete implementation is blunting the potential impact on learning and patient outcomes. The fundamental principles of CBME call for standardizing outcomes addressing population health needs, then allowing time-variable progression to achieving them. Operationalizing CBME principles requires continuity within and across phases of the education, training, and practice continuum. However, the piecemeal origin of the phases of the "continuum" has resulted in a sequence of undergraduate to graduate medical education to practice that may be continuous temporally but bears none of the integration of a true continuum.With these timed interruptions during phase transitions, learning is not reinforced because of a failure to integrate experiences. Brief block rotations for learners and ever-shorter supervisory assignments for faculty preclude the development of relationships. Without these relationships, feedback falls on deaf ears. Block rotations also disrupt learners' relationships with patients. The harms resulting from such a system include decreases in patient satisfaction with their care and learner satisfaction with their work. Learners in this block system also demonstrate an erosion of empathy compared with those in innovative longitudinal training models. In addition, higher patient mortality during intern transitions has been demonstrated.The current medical education system is violating the first principle of medicine: "Do no harm." Full implementation of competency-based, time-variable education and training, with fixed outcomes aligned with population health needs, continuity in learning and relationships, and support from a developmental program of assessment, holds great potential to stop this harm.

A MAC Mode for Lightweight Block Ciphers

DEFF Research Database (Denmark)

Luykx, Atul; Preneel, Bart; Tischhauser, Elmar Wolfgang

2016-01-01

Lightweight cryptography strives to protect communication in constrained environments without sacrificing security. However, security often conflicts with efficiency, shown by the fact that many new lightweight block cipher designs have block sizes as low as 64 or 32 bits. Such low block sizes lead...... no effect on the security bound, allowing an order of magnitude more data to be processed per key. Furthermore, LightMAC is incredibly simple, has almost no overhead over the block cipher, and is parallelizable. As a result, LightMAC not only offers compact authentication for resource-constrained platforms...

Climatological features of blocking anticyclones

International Nuclear Information System (INIS)

Lupo, A.R.; Smith, P.J.; Oglesby, R.J.

1994-01-01

Several climatological studies have been previously performed using large observational data sets (i.e., 10 years or longer) in order to determine the predominant characteristics of blocking anticyclones, including favored development regions, duration, preferred seasonal occurrence, and frequency of occurrence. These studies have shown that blocking anticyclones occur most frequently from October to April over the eastern Atlantic and Pacific oceans downstream from both the North American and Asian continental regions and the storm track regions to the east of these continents. Some studies have also revealed the presence of a third region block formation in western Russia near 40 degrees E which is associated with another storm track region over the Mediterranean and western Asia

Rectangular amplitudes, conformal blocks, and applications to loop models

Energy Technology Data Exchange (ETDEWEB)

Bondesan, Roberto, E-mail: roberto.bondesan@cea.fr [LPTENS, Ecole Normale Superieure, 24 rue Lhomond, 75231 Paris (France); Institute de Physique Theorique, CEA Saclay, F-91191 Gif-sur-Yvette (France); Jacobsen, Jesper L. [LPTENS, Ecole Normale Superieure, 24 rue Lhomond, 75231 Paris (France); Universite Pierre et Marie Curie, 4 place Jussieu, 75252 Paris (France); Saleur, Hubert [Institute de Physique Theorique, CEA Saclay, F-91191 Gif-sur-Yvette (France); Physics Department, USC, Los Angeles, CA 90089-0484 (United States)

2013-02-21

In this paper we continue the investigation of partition functions of critical systems on a rectangle initiated in [R. Bondesan, et al., Nucl. Phys. B 862 (2012) 553-575]. Here we develop a general formalism of rectangle boundary states using conformal field theory, adapted to describe geometries supporting different boundary conditions. We discuss the computation of rectangular amplitudes and their modular properties, presenting explicit results for the case of free theories. In a second part of the paper we focus on applications to loop models, discussing in details lattice discretizations using both numerical and analytical calculations. These results allow to interpret geometrically conformal blocks, and as an application we derive new probability formulas for self-avoiding walks.

Thermal-stress analysis of HTGR fuel and control rod fuel blocks in in-block carbonization and annealing furnace

International Nuclear Information System (INIS)

Gwaltney, R.C.; McAfee, W.J.

1977-01-01

The equivalent solid plate method, in conjunction with two-dimensional plane stress and plane strain analyses, was used in assessing the thermal stress behavior of HTGR fuel and control rod fuel blocks. For the control rod fuel blocks, particular attention was given to ascertaining the effects of the reserve shutdown hole and the control rod channel holes. The assumed safety factor of 2 on the failure criteria was considered adequate to account for neglecting the axial temperature gradient in the plane analyses of the ends of the blocks. The analyses indicated that the maximum calculated tensile stress values were smaller than the criteria values except for the plane strain analysis of the control rod fuel block end surfaces and the axisymmetric analysis of the fuel block as a circular cylinder. However, most of the maximum calculated strain values were greater than the criteria values

Functional Nanoporous Polymers from Block Copolymer Precursors

DEFF Research Database (Denmark)

Guo, Fengxiao

Abstract Self-assembly of block copolymers provides well-defined morphologies with characteristic length scales in the nanometer range. Nanoporous polymers prepared by selective removal of one block from self-assembled block copolymers offer great technological promise due to their many potential...... functionalities remains a great challenge due to the limitation of available polymer synthesis and the nanoscale confinement of the porous cavities. The main topic of this thesis is to develop methods for fabrication of functional nanoporous polymers from block copolymer precursors. A method has been developed......, where living anionic polymerization and atom transfer radical polymerization (ATRP) are combined to synthesize a polydimethylsiloxane-b-poly(tert-butyl acrylate)-b-polystyrene (PDMS-b-PtBA-b-PS) triblock copolymer precursor. By using either anhydrous hydrogen fluoride or trifluoroacetic acid, PtBA block...

Forbidden subgraph pairs for traceability of block-chains

Directory of Open Access Journals (Sweden)

Binlong Li

2013-04-01

Full Text Available A block-chain is a graph whose block graph is a path, i.e. it is either a $P_1$, a $P_2$, or a 2-connected graph, or a graph of connectivity 1 with exactly two end-blocks. A graph is called traceable if it contains a Hamilton path. A traceable graph is clearly a block-chain, but the reverse does not hold in general.In this paper we characterize all pairs of connected graphs $\\{R,S\\}$ such that every $\\{R,S\\}$-free block-chain is traceable.

Synthesis of Functional Block Copolymers Carrying One Poly( p -phenylenevinylene) and One Nonconjugated Block in a Facile One-Pot Procedure

KAUST Repository

Menk, Florian

2016-02-29

Block copolymers composed of a MEH-PPV block and a nonconjugated functional block (molecular weights between 5 and 90 kg/mol) were synthesized in a facile one-pot procedure via ROMP. This one-pot procedure permits the synthesis of numerous block copolymers with little effort. Amphiphilic block copolymers were obtained via incorporation of oxanorbornene carrying a PEG side chain as well as via postpolymerization modification of a reactive ester carrying norbornene derivative with methoxypoly(ethylene glycol)amine. These amphiphilic block copolymers can be self-assembled into micelles exhibiting different sizes (60-95 nm), morphologies (micelles or fused, caterpillar-like micelles), and optical properties depending on the polymer composition and the micellization procedure. Furthermore, the reactive ester carrying block copolymers enabled the introduction of anchor groups which facilitated the preparation of nanocomposites with CdSe/CdZnS core-shell QDs. The obtained composites were studied using time-resolved photoluminescence measurements. The results revealed an increased interaction based on an accelerated decay of the QD emission for composites as compared to the mixture of the QDs with unfunctionalized polymers. © 2016 American Chemical Society.

Synthesis of Functional Block Copolymers Carrying One Poly( p -phenylenevinylene) and One Nonconjugated Block in a Facile One-Pot Procedure

KAUST Repository

Menk, Florian; Shin, Suyong; Kim, Kyung-Oh; Scherer, Martin; Gehrig, Dominik; Laquai, Fré dé ric; Choi, Tae-Lim; Zentel, Rudolf

2016-01-01

Block copolymers composed of a MEH-PPV block and a nonconjugated functional block (molecular weights between 5 and 90 kg/mol) were synthesized in a facile one-pot procedure via ROMP. This one-pot procedure permits the synthesis of numerous block copolymers with little effort. Amphiphilic block copolymers were obtained via incorporation of oxanorbornene carrying a PEG side chain as well as via postpolymerization modification of a reactive ester carrying norbornene derivative with methoxypoly(ethylene glycol)amine. These amphiphilic block copolymers can be self-assembled into micelles exhibiting different sizes (60-95 nm), morphologies (micelles or fused, caterpillar-like micelles), and optical properties depending on the polymer composition and the micellization procedure. Furthermore, the reactive ester carrying block copolymers enabled the introduction of anchor groups which facilitated the preparation of nanocomposites with CdSe/CdZnS core-shell QDs. The obtained composites were studied using time-resolved photoluminescence measurements. The results revealed an increased interaction based on an accelerated decay of the QD emission for composites as compared to the mixture of the QDs with unfunctionalized polymers. © 2016 American Chemical Society.

Quantization Distortion in Block Transform-Compressed Data

Science.gov (United States)

Boden, A. F.

1995-01-01

The popular JPEG image compression standard is an example of a block transform-based compression scheme; the image is systematically subdivided into block that are individually transformed, quantized, and encoded. The compression is achieved by quantizing the transformed data, reducing the data entropy and thus facilitating efficient encoding. A generic block transform model is introduced.

21 CFR 520.905e - Fenbendazole blocks.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Fenbendazole blocks. 520.905e Section 520.905e... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.905e Fenbendazole blocks. (a) Specifications. (1) Each pound of molasses block contains 750 milligrams of fenbendazole. (2) Each pound of...

Ultrasound-guided truncal blocks: A new frontier in regional anaesthesia

Directory of Open Access Journals (Sweden)

Arunangshu Chakraborty

2016-01-01

Full Text Available The practice of regional anaesthesia is rapidly changing with the introduction of ultrasound into the working domain of the anaesthesiologist. New techniques are being pioneered. Among the recent techniques, notable are the truncal blocks, for example, the transversus abdominis plane block, rectus sheath block, hernia block and quadratus lumborum block in the abdomen and the pectoral nerves (Pecs block 1 and 2, serratus anterior plane block and intercostal nerve block. This narrative review covers the brief anatomical discourse along with technical description of the ultrasound-guided truncal blocks.

Block copolymer membranes for aqueous solution applications

KAUST Repository

Nunes, Suzana Pereira

2016-03-22

Block copolymers are known for their intricate morphology. We review the state of the art of block copolymer membranes and discuss perspectives in this field. The main focus is on pore morphology tuning with a short introduction on non-porous membranes. The two main strategies for pore formation in block copolymer membranes are (i) film casting and selective block sacrifice and (ii) self-assembly and non-solvent induced phase separation (SNIPS). Different fundamental aspects involved in the manufacture of block copolymer membranes are considered, including factors affecting the equilibrium morphology in solid films, self-assembly of copolymer in solutions and macrophase separation by solvent-non-solvent exchange. Different mechanisms are proposed for different depths of the SNIPS membrane. Block copolymer membranes can be prepared with much narrower pore size distribution than homopolymer membranes. Open questions and indications of what we consider the next development steps are finally discussed. They include the synthesis and application of new copolymers and specific functionalization, adding characteristics to respond to stimuli and chemical environment, polymerization-induced phase separation, and the manufacture of organic-inorganic hybrids.

Capacitor blocks for linear transformer driver stages.

Science.gov (United States)

Kovalchuk, B M; Kharlov, A V; Kumpyak, E V; Smorudov, G V; Zherlitsyn, A A

2014-01-01

In the Linear Transformer Driver (LTD) technology, the low inductance energy storage components and switches are directly incorporated into the individual cavities (named stages) to generate a fast output voltage pulse, which is added along a vacuum coaxial line like in an inductive voltage adder. LTD stages with air insulation were recently developed, where air is used both as insulation in a primary side of the stages and as working gas in the LTD spark gap switches. A custom designed unit, referred to as a capacitor block, was developed for use as a main structural element of the transformer stages. The capacitor block incorporates two capacitors GA 35426 (40 nF, 100 kV) and multichannel multigap gas switch. Several modifications of the capacitor blocks were developed and tested on the life time and self breakdown probability. Blocks were tested both as separate units and in an assembly of capacitive module, consisting of five capacitor blocks. This paper presents detailed design of capacitor blocks, description of operation regimes, numerical simulation of electric field in the switches, and test results.

Block copolymer membranes for aqueous solution applications

KAUST Repository

Nunes, Suzana Pereira

2016-01-01

Block copolymers are known for their intricate morphology. We review the state of the art of block copolymer membranes and discuss perspectives in this field. The main focus is on pore morphology tuning with a short introduction on non-porous membranes. The two main strategies for pore formation in block copolymer membranes are (i) film casting and selective block sacrifice and (ii) self-assembly and non-solvent induced phase separation (SNIPS). Different fundamental aspects involved in the manufacture of block copolymer membranes are considered, including factors affecting the equilibrium morphology in solid films, self-assembly of copolymer in solutions and macrophase separation by solvent-non-solvent exchange. Different mechanisms are proposed for different depths of the SNIPS membrane. Block copolymer membranes can be prepared with much narrower pore size distribution than homopolymer membranes. Open questions and indications of what we consider the next development steps are finally discussed. They include the synthesis and application of new copolymers and specific functionalization, adding characteristics to respond to stimuli and chemical environment, polymerization-induced phase separation, and the manufacture of organic-inorganic hybrids.

MRI findings on iatrogenic spinal infection following various pain management procedures

International Nuclear Information System (INIS)

Kim, Yu Jin; Lee, Jee Young; Kim, Bong Man; Min, Sang Hyuk

2014-01-01

The aim of this study was to investigate and report magnetic resonance imaging (MRI) findings of iatrogenic spinal infection (ISI). We retrospectively reviewed the clinical and MRI findings on 18 patients diagnosed with ISI. The MRI findings were evaluated for the number of spinal segments showing inflammation in the longitudinal span and affected vertebral bodies and discs, the presence of abscess in the epidural or paravertebral space, paravertebral myositis, and skip lesions. Among the 18 patients, the range of the longitudinal span of spinal inflammation was 2-11 (mean = 5.84) vertebral segments. 17 of the 18 patients had three or more contiguous vertebral segments. The osteomyelitis and disc destruction was apparent in 77.8% and 66.7% of the patients, and 78% of patients with osteomyelitis showed involvement of one or two vertebrae; 91.7% of patients with disc destruction showed involvement of single disc. The incidence of epidural or paravertebral abscesses, and paravertebral myositis were 88.9%, and 94.4%. There were no spinal skip lesions. MRI findings of those are wide longitudinal span of infection, involvement of no more than one or two vertebral bodies and a single disc, large abscesses, extensive myositis and no skip lesions, can be a useful ISI-diagnostic tool.

MRI findings on iatrogenic spinal infection following various pain management procedures

Energy Technology Data Exchange (ETDEWEB)

Kim, Yu Jin; Lee, Jee Young; Kim, Bong Man [Dept. of Radiology, Dankook University Hospital, Cheonan (Korea, Republic of); Min, Sang Hyuk [Dept. of Orthopedic Surgery, Dankook University Hospital, Cheonan (Korea, Republic of)

2014-12-15

The aim of this study was to investigate and report magnetic resonance imaging (MRI) findings of iatrogenic spinal infection (ISI). We retrospectively reviewed the clinical and MRI findings on 18 patients diagnosed with ISI. The MRI findings were evaluated for the number of spinal segments showing inflammation in the longitudinal span and affected vertebral bodies and discs, the presence of abscess in the epidural or paravertebral space, paravertebral myositis, and skip lesions. Among the 18 patients, the range of the longitudinal span of spinal inflammation was 2-11 (mean = 5.84) vertebral segments. 17 of the 18 patients had three or more contiguous vertebral segments. The osteomyelitis and disc destruction was apparent in 77.8% and 66.7% of the patients, and 78% of patients with osteomyelitis showed involvement of one or two vertebrae; 91.7% of patients with disc destruction showed involvement of single disc. The incidence of epidural or paravertebral abscesses, and paravertebral myositis were 88.9%, and 94.4%. There were no spinal skip lesions. MRI findings of those are wide longitudinal span of infection, involvement of no more than one or two vertebral bodies and a single disc, large abscesses, extensive myositis and no skip lesions, can be a useful ISI-diagnostic tool.

Block circulant and block Toeplitz approximants of a class of spatially distributed systems-An LQR perspective

NARCIS (Netherlands)

Iftime, Orest V.

2012-01-01

In this paper block circulant and block Toeplitz long strings of MIMO systems with finite length are compared with their corresponding infinite-dimensional spatially invariant systems. The focus is on the convergence of the sequence of solutions to the control Riccati equations and the convergence

Gnawing blocks as cage enrichment and dietary supplement for does and fatteners: intake, performance and behaviour

Directory of Open Access Journals (Sweden)

Luc Maertens

2013-09-01

Full Text Available The aim of this study was to evaluate different experimental gnawing blocks as cage enrichment in rabbits. One hundred and five pregnant rabbit does housed in conventional wire cages were distributed according to their parity number in 4 homogenous treatment groups. Throughout one complete reproductive cycle (from day 18 of pregnancy till weaning of the litter, does either received no enrichment (controls or a gnawing block hung from a wire on the cage wall. The 3 different blocks had the same basal components (wheat, molasses and oligoelements, but additionally wood mash (WM, wood mash+chicory pulp (ChP or wood mash and inulin syrup (I were respectively incorporated. After weaning, each litter continued to receive the same blocks as before and block consumption was measured as well as the performance of the fatteners. Weight development during the lactation was comparable except in does that received the wood powder blocks. These females had a significantly lower weight (P<0.05 at different time points compared to controls. Litter weight or kit weight was not significantly different at any of the time points measured, but again the treatment with wood powder blocks presented the lowest weight. The consumption of blocks during the whole reproduction cycle (42 d was 11.0±1.1; 6.8±1.0 and 4.4±0.7 g/d per cage for wood mash, chicory pulp or inulin enriched blocks, respectively. A very high variability in consumption of blocks was observed between females. This varied between 1 and 5 (I or ChP group or even 1 and 9 blocks (WM group per reproductive cycle. In fatteners, daily block consumption was significantly different (P<0.05 and reached on average 7.0±0.5; 3.9±0.5 and 2.2±0.2 g/d per fattener, respectively for WM, ChP and I. Five females with a block and 5 females without a block were observed for 1 h 3 d before the expected parturition and at 2 time points during lactation. Distinction was made between 15 different behaviours. Although the

Block storage subsystem performance analysis

CERN Multimedia

CERN. Geneva

2016-01-01

You feel that your service is slow because of the storage subsystem? But there are too many abstraction layers between your software and the raw block device for you to debug all this pile... Let's dive on the platters and check out how the block storage sees your I/Os! We can even figure out what those patterns are meaning.

A Novel Tetrathiafulvalene Building Block

DEFF Research Database (Denmark)

Jeppesen, Jan Oskar; Takimiya, Kazuo; Thorup, Niels

1999-01-01

Efficient synthesis of a novel tetrathiafulvalene building block. 2,3-bis(2-cyanoethylthio)-6,7-bis(thiocyanato-methyl)tetrathiafulv alene (7) useful for stepwise and asymmetrical bis-function-alization is reported.......Efficient synthesis of a novel tetrathiafulvalene building block. 2,3-bis(2-cyanoethylthio)-6,7-bis(thiocyanato-methyl)tetrathiafulv alene (7) useful for stepwise and asymmetrical bis-function-alization is reported....

Forbidden subgraph pairs for traceability of block-chains

NARCIS (Netherlands)

Li, Binlong; Li, Binlong; Broersma, Haitze J.; Zhang, Shenggui

2013-01-01

A block-chain is a graph whose block graph is a path, i.e. it is either a P1, a P2, or a 2-connected graph, or a graph of connectivity 1 with exactly two end-blocks. A graph is called traceable if it contains a Hamilton path. A traceable graph is clearly a block-chain, but the reverse does not hold

Blocking device especially for circulating pumps

International Nuclear Information System (INIS)

Susil, J.; Vychodil, V.; Lorenc, P.

1976-01-01

The claim of the invention is a blocking device which blocks reverse flow occurring after the shutdown of circulating pumps, namely in the operation of nuclear power plants or in pumps with a high delivery head. (F.M.)

Rapid self-assembly of block copolymers to photonic crystals

Science.gov (United States)

Xia, Yan; Sveinbjornsson, Benjamin R; Grubbs, Robert H; Weitekamp, Raymond; Miyake, Garret M; Atwater, Harry A; Piunova, Victoria; Daeffler, Christopher Scot; Hong, Sung Woo; Gu, Weiyin; Russell, Thomas P.

2016-07-05

The invention provides a class of copolymers having useful properties, including brush block copolymers, wedge-type block copolymers and hybrid wedge and polymer block copolymers. In an embodiment, for example, block copolymers of the invention incorporate chemically different blocks comprising polymer size chain groups and/or wedge groups that significantly inhibit chain entanglement, thereby enhancing molecular self-assembly processes for generating a range of supramolecular structures, such as periodic nanostructures and microstructures. The present invention also provides useful methods of making and using copolymers, including block copolymers.

Conjugated Polymer Chains Confined in Vertical Nanocylinders of a Block-Copolymer Film: Preparation, Characterization, and Optoelectronic Function

KAUST Repository

Dong, Ban Xuan; Honmou, Yoshihiro; Komiyama, Hideaki; Furumaki, Shu; Iyoda, Tomokazu; Vacha, Martin

2013-01-01

Hybrid materials composed of phase-separated block copolymer films and conjugated polymers of the phenylenevinylene family (PPV) are prepared. The PPV chains are embedded in vertical cylinders of nanometer diameter in the block-copolymer films. The cylinders span continuously the whole film thickness of 70 nm. Incorporation of the PPV chains into the one-dimensional cylinders leads to modified photoluminescence spectra and to large absorption anisotropy. The hybrid films show electroluminescence from the PPV chains in a simple light-emitting device at minute doping concentrations, and also exhibit a factor of 19 increase in electron transport efficiency along the single PPV chains. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Conjugated Polymer Chains Confined in Vertical Nanocylinders of a Block-Copolymer Film: Preparation, Characterization, and Optoelectronic Function

KAUST Repository

Dong, Ban Xuan

2013-01-15

Hybrid materials composed of phase-separated block copolymer films and conjugated polymers of the phenylenevinylene family (PPV) are prepared. The PPV chains are embedded in vertical cylinders of nanometer diameter in the block-copolymer films. The cylinders span continuously the whole film thickness of 70 nm. Incorporation of the PPV chains into the one-dimensional cylinders leads to modified photoluminescence spectra and to large absorption anisotropy. The hybrid films show electroluminescence from the PPV chains in a simple light-emitting device at minute doping concentrations, and also exhibit a factor of 19 increase in electron transport efficiency along the single PPV chains. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Functionalization of Block Copolymer Vesicle Surfaces

Directory of Open Access Journals (Sweden)

Wolfgang Meier

2011-01-01

Full Text Available In dilute aqueous solutions certain amphiphilic block copolymers self-assemble into vesicles that enclose a small pool of water with a membrane. Such polymersomes have promising applications ranging from targeted drug-delivery devices, to biosensors, and nanoreactors. Interactions between block copolymer membranes and their surroundings are important factors that determine their potential biomedical applications. Such interactions are influenced predominantly by the membrane surface. We review methods to functionalize block copolymer vesicle surfaces by chemical means with ligands such as antibodies, adhesion moieties, enzymes, carbohydrates and fluorophores. Furthermore, surface-functionalization can be achieved by self-assembly of polymers that carry ligands at their chain ends or in their hydrophilic blocks. While this review focuses on the strategies to functionalize vesicle surfaces, the applications realized by, and envisioned for, such functional polymersomes are also highlighted.

Theory of circuit block switch-off

Directory of Open Access Journals (Sweden)

S. Henzler

2004-01-01

Full Text Available Switching-off unused circuit blocks is a promising approach to supress static leakage currents in ultra deep sub-micron CMOS digital systems. Basic performance parameters of Circuit Block Switch-Off (CBSO schemes are defined and their dependence on basic circuit parameters is estimated. Therefore the design trade-off between strong leakage suppression in idle mode and adequate dynamic performance in active mode can be supported by simple analytic investigations. Additionally, a guideline for the estimation of the minimum time for which a block deactivation is useful is derived.

Productivity assessment of Angola's oil blocks

International Nuclear Information System (INIS)

Barros, Carlos Pestana; Managi, Shunsuke

2009-01-01

This paper analyzes the change in productivity as a result of Angola oil policy from 2001 to 2007. Angola oil blocks are the main source of tax receipts and, therefore, strategically important for public finances. A Malmquist index with the input technological bias is applied to measure productivity change. Oil blocks on average became both more efficient and experienced technological progress. Our results indicate that the traditional growth accounting method, which assumes Hicks neutral technological change, is not appropriate for analyzing changes in productivity for Angola oil blocks. Policy implications are derived. (author)

The use of non-invasive fetal electrocardiography in diagnosing second-degree fetal atrioventricular block.

Science.gov (United States)

Lakhno, Igor; Behar, Joachim A; Oster, Julien; Shulgin, Vyacheslav; Ostras, Oleksii; Andreotti, Fernando

2017-01-01

Complete atrioventricular block in fetuses is known to be mostly associated with autoimmune disease and can be irreversible if no steroids treatment is provided. Conventional methods used in clinical practice for diagnosing fetal arrhythmia are limited since they do not reflect the primary electrophysiological conduction processes that take place in the myocardium. The non-invasive fetal electrocardiogram has the potential to better support fetal arrhythmias diagnosis through the continuous analysis of the beat to beat variation of the fetal heart rate and morphological analysis of the PQRST complex. We present two retrospective case reports on which atrioventricular block diagnosis could have been supported by the non-invasive fetal electrocardiogram. The two cases comprised a 22-year-old pregnant woman with the gestational age of 31 weeks and a 25-year-old pregnant woman with the gestational age of 41 weeks. Both women were admitted to the Department of Maternal and Fetal Medicine at the Kyiv and Kharkiv municipal perinatal clinics. Patients were observed using standard fetal monitoring methods as well as the non-invasive fetal electrocardiogram. The non-invasive fetal electrocardiographic recordings were analyzed retrospectively, where it is possible to identify the presence of the atrioventricular block. This study demonstrates, for the first time, the feasibility of the non-invasive fetal electrocardiogram as a supplementary method to diagnose of the fetal atrioventricular block. Combined with current fetal monitoring techniques, non-invasive fetal electrocardiography could support clinical decisions.

Comparison of extent of sensory block following posterior and subcostal approaches to ultrasound-guided transversus abdominis plane block.

Science.gov (United States)

Lee, T H W; Barrington, M J; Tran, T M N; Wong, D; Hebbard, P D

2010-05-01

Transversus abdominis plane block provides postoperative analgesia following abdominal surgery by targeting thoracolumbar nerves between the internal oblique and transversus abdominis muscles. Posterior and subcostal approaches using ultrasound guidance have been described. However there have been inconsistent results in relation to the extent of the sensory block. This observational study evaluated the distributions of sensory block following either a posterior or subcostal approach and the quality of analgesia achieved. Following ethics committee approval, 50 patients undergoing minimally invasive and major abdominal surgery were recruited. A total of 81 transversus abdominis plane blocks were performed preoperatively under real-time ultrasound guidance. Postoperatively, patients received multimodal analgesia including morphine via patient-controlled pumps. Ninety-eight percent of patients had some degree of demonstrable sensory block and the dermatomal spread differed between posterior and subcostal approaches (P interquartile range 2 to 4), the most cephalad being T10 (interquartile range T9 to T10), while the subcostal approach blocked a median of four segments (interquartile range 3 to 5), the most cephalad being T8 (interquartile range T7 to T9, P interquartile range 17 to 50 mg) at 24 hours. Median pain scores at rest and with coughing were 20 (interquartile range 10 to 35) and 50 (interquartile range 29 to 67) respectively at 24 hours. The posterior approach appears to be more appropriate for lower abdominal surgery and the subcostal approach better suited to upper abdominal surgery. Whichever approach is used, transversus abdominis plane block is only one component of a multimodal analgesic technique.

Block Textured a-Si:H Solar Cell

Directory of Open Access Journals (Sweden)

Seung Jae Moon

2014-01-01

Full Text Available A series of etching experiments on light trapping structure have been carried out by glass etching. The block structure provides long light traveling path and a constant distance between the cathode and anode electrodes regardless of the block height, which results in higher efficiency of the block textured solar cell. In terms of etching profile of the glass substrate, the addition of NH4F resulted in the smooth and clean etching profile, and the steep slope of the block was obtained by optimizing the composition of etching solution. For a higher HF concentration, a more graded slope was obtained and the addition of HNO3 and NH4F provided steep slope and clean etching profile. The effects of the block textured glass were verified by a comparison of the solar cell efficiency. For the textured solar cell, the surface was much rougher than that of the plain glass, which also contributes to the improvement of the efficiency. We accomplished block shaped light trapping structure for the first time by wet etching of the glass substrate, which enables the high efficiency thin film solar cell with the aid of the good step coverage deposition.

Direct block scheduling technology: Analysis of Avidity

Directory of Open Access Journals (Sweden)

Felipe Ribeiro Souza

Full Text Available Abstract This study is focused on Direct Block Scheduling testing (Direct Multi-Period Scheduling methodology which schedules mine production considering the correct discount factor of each mining block, resulting in the final pit. Each block is analyzed individually in order to define the best target period. This methodology presents an improvement of the classical methodology derived from Lerchs-Grossmann's initial proposition improved by Whittle. This paper presents the differences between these methodologies, specially focused on the algorithms' avidity. Avidity is classically defined by the voracious search algorithms, whereupon some of the most famous greedy algorithms are Branch and Bound, Brutal Force and Randomized. Strategies based on heuristics can accentuate the voracity of the optimizer system. The applied algorithm use simulated annealing combined with Tabu Search. The most avid algorithm can select the most profitable blocks in early periods, leading to higher present value in the first periods of mine operation. The application of discount factors to blocks on the Lerchs-Grossmann's final pit has an accentuated effect with time, and this effect may make blocks scheduled for the end of the mine life unfeasible, representing a trend to a decrease in reported reserves.

Exploring atmospheric blocking with GPS radio occultation observations

Directory of Open Access Journals (Sweden)

L. Brunner

2016-04-01

Full Text Available Atmospheric blocking has been closely investigated in recent years due to its impact on weather and climate, such as heat waves, droughts, and flooding. We use, for the first time, satellite-based observations from Global Positioning System (GPS radio occultation (RO and explore their ability to resolve blocking in order to potentially open up new avenues complementing models and reanalyses. RO delivers globally available and vertically highly resolved profiles of atmospheric variables such as temperature and geopotential height (GPH. Applying a standard blocking detection algorithm, we find that RO data robustly capture blocking as demonstrated for two well-known blocking events over Russia in summer 2010 and over Greenland in late winter 2013. During blocking episodes, vertically resolved GPH gradients show a distinct anomalous behavior compared to climatological conditions up to 300 hPa and sometimes even further up into the tropopause. The accompanying increase in GPH of up to 300 m in the upper troposphere yields a pronounced tropopause height increase. Corresponding temperatures rise up to 10 K in the middle and lower troposphere. These results demonstrate the feasibility and potential of RO to detect and resolve blocking and in particular to explore the vertical structure of the atmosphere during blocking episodes. This new observation-based view is available globally at the same quality so that blocking in the Southern Hemisphere can also be studied with the same reliability as in the Northern Hemisphere.

The blocking reagent optimization for the magnetoelastic biosensor

Science.gov (United States)

Hu, Jiajia; Chai, Yating; Horikawa, Shin; Wikle, Howard C.; Wang, Feng'en; Du, Songtao; Chin, Bryan A.; Hu, Jing

2015-06-01

The wireless phage-based magnetoelastic (ME) biosensor has proven to be promising for real-time detection of pathogenic bacteria on fresh produces. The ME biosensor consists of a freestanding ME resonator as the signal transducer and filamentous phage as the biomolecular-recognition element, which can specifically bind to a pathogen of interest. Due to the Joule magnetostriction effect, the biosensors can be placed into mechanical resonance when subjected to a time-varying magnetic field alternating at the sensor's resonant frequency. Upon the attachment of the target pathogen, the mass of the biosensor increases, thereby decreasing its resonant frequency. This paper presents an investigation of blocking reagents immobilization for detecting Salmonella Typhimurium on fresh food surfaces. Three different blocking reagents (BSA, SuperBlock blocking buffer, and blocker BLOTTO) were used and compared. The optical microscope was used for bacterial cells binding observation. Student t-test was used to statistically analysis the experiment results. The results shows that SuperBlock blocking buffer and blocker BLOTTO have much better blocking performance than usually used BSA.

Block ground interaction of rockfalls

Science.gov (United States)

Volkwein, Axel; Gerber, Werner; Kummer, Peter

2016-04-01

During a rockfall the interaction of the falling block with the ground is one of the most important factors that define the evolution of a rockfall trajectory. It steers the rebound, the rotational movement, possibly brake effects, friction losses and damping effects. Therefore, if most reliable rockfall /trajectory simulation software is sought a good understanding of the block ground interaction is necessary. Today's rockfall codes enable the simulation of a fully 3D modelled block within a full 3D surface . However, the details during the contact, i.e. the contact duration, the penetration depth or the dimension of the marks in the ground are usually not part of the simulation. Recent field tests with rocks between 20 and 80 kg have been conducted on a grassy slope in 2014 [1]. A special rockfall sensor [2] within the blocks measured the rotational velocity and the acting accelerations during the tests. External video records and a so-called LocalPositioningSystem deliver information on the travel velocity. With these data not only the flight phases of the trajectories but also the contacts with the ground can be analysed. During the single jumps of a block the flight time, jump length, the velocity, and the rotation are known. During the single impacts their duration and the acting accelerations are visible. Further, the changes of rotational and translational velocity influence the next jump of the block. The change of the rotational velocity over the whole trajectory nicely visualizes the different phases of a rockfall regarding general acceleration and deceleration in respect to the inclination and the topography of the field. References: [1] Volkwein A, Krummenacher B, Gerber W, Lardon J, Gees F, Brügger L, Ott T (2015) Repeated controlled rockfall trajectory testing. [Abstract] Geophys. Res. Abstr. 17: EGU2015-9779. [2] Volkwein A, Klette J (2014) Semi-Automatic Determination of Rockfall Trajectories. Sensors 14: 18187-18210.

Degenerate operators and the 1/c expansion: Lorentzian resummations, high order computations, and super-Virasoro blocks

Energy Technology Data Exchange (ETDEWEB)

Chen, Hongbin [Department of Physics and Astronomy, Johns Hopkins University,Charles Street, Baltimore, MD 21218 (United States); Fitzpatrick, A. Liam [Department of Physics, Boston University,Commonwealth Avenue, Boston, MA 02215 (United States); Kaplan, Jared; Li, Daliang; Wang, Junpu [Department of Physics and Astronomy, Johns Hopkins University,Charles Street, Baltimore, MD 21218 (United States)

2017-03-30

One can obtain exact information about Virasoro conformal blocks by analytically continuing the correlators of degenerate operators. We argued in recent work that this technique can be used to explicitly resolve information loss problems in AdS{sub 3}/CFT{sub 2}. In this paper we use the technique to perform calculations in the small 1/c∝G{sub N} expansion: (1) we prove the all-orders resummation of logarithmic factors ∝(1/c)log z in the Lorentzian regime, demonstrating that 1/c corrections directly shift Lyapunov exponents associated with chaos, as claimed in prior work, (2) we perform another all-orders resummation in the limit of large c with fixed cz, interpolating between the early onset of chaos and late time behavior, (3) we explicitly compute the Virasoro vacuum block to order 1/c{sup 2} and 1/c{sup 3} with external dimensions fixed, corresponding to 2 and 3 loop calculations in AdS{sub 3}, and (4) we derive the heavy-light vacuum blocks in theories with N=1,2 superconformal symmetry.

From global to heavy-light: 5-point conformal blocks

International Nuclear Information System (INIS)

Alkalaev, Konstantin; Belavin, Vladimir

2016-01-01

We consider Virasoro conformal blocks in the large central charge limit. There are different regimes depending on the behavior of the conformal dimensions. The most simple regime is reduced to the global sl(2,ℂ) conformal blocks while the most complicated one is known as the classical conformal blocks. Recently, Fitzpatrick, Kaplan, and Walters showed that the two regimes are related through the intermediate stage of the so-called heavy-light semiclassical limit. We study this idea in the particular case of the 5-point conformal block. To find the 5-point global block we use the projector technique and the Casimir operator approach. Furthermore, we discuss the relation between the global and the heavy-light limits and construct the heavy-light block from the global block. In this way we reproduce our previous results for the 5-point perturbative classical block obtained by means of the monodromy method.

Crustal block motion model and interplate coupling along Ecuador-Colombia trench based on GNSS observation network

Science.gov (United States)

Ito, T.; Mora-Páez, H.; Peláez-Gaviria, J. R.; Kimura, H.; Sagiya, T.

2017-12-01

IntroductionEcuador-Colombia trench is located at the boundary between South-America plate, Nazca Plate and Caribrian plate. This region is very complexes such as subducting Caribrian plate and Nazca plate, and collision between Panama and northern part of the Andes mountains. The previous large earthquakes occurred along the subducting boundary of Nazca plate, such as 1906 (M8.8) and 1979 (M8.2). And also, earthquakes occurred inland, too. So, it is important to evaluate earthquake potentials for preparing huge damage due to large earthquake in near future. GNSS observation In the last decade, the GNSS observation was established in Columbia. The GNSS observation is called by GEORED, which is operated by servicing Geologico Colomiano. The purpose of GEORED is research of crustal deformation. The number of GNSS site of GEORED is consist of 60 continuous GNSS observation site at 2017 (Mora et al., 2017). The sampling interval of almost GNSS site is 30 seconds. These GNSS data were processed by PPP processing using GIPSY-OASYS II software. GEORED can obtain the detailed crustal deformation map in whole Colombia. In addition, we use 100 GNSS data at Ecuador-Peru region (Nocquet et al. 2014). Method We developed a crustal block movements model based on crustal deformation derived from GNSS observation. Our model considers to the block motion with pole location and angular velocity and the interplate coupling between each block boundaries, including subduction between the South-American plate and the Nazca plate. And also, our approach of estimation of crustal block motion and coefficient of interplate coupling are based on MCMC method. The estimated each parameter is obtained probably density function (PDF). Result We tested 11 crustal block models based on geological data, such as active fault trace at surface. The optimal number of crustal blocks is 11 for based on geological and geodetic data using AIC. We use optimal block motion model. And also, we estimate

Stabilization of colloidal palladium particles by a block copolymer of polystyrene and a block containing amide sidegroups

NARCIS (Netherlands)

Roescher, G.A.; Roescher, A.; Hempenius, Mark A.; Klok, H.A.; Moller, M.; Möller, M.

1996-01-01

A block copolymer of polystyrene and poly(tert-butylmethacrylate) was prepared by anionic polymerization. The ester groups of the poly(tert-butylmethacrylate) were hydrolyzed, after wich the remaining carboxyl groups were reacted with pyrrolidine. The resulting block copolymer with amide sidegroups

Fabrication and handling of bentonite blocks

International Nuclear Information System (INIS)

1978-06-01

In accordance with the project for the final storage of spent nuclear fuel, the waste will be encapsulated into copper canisters, which will be deposited in a final repository located in rock 500 m below ground level. The canisters will be placed in vertical holes in the bottoms of the tunnels, where the copper cylinders will be surrounded by blocks of highly compacted bentonite. When the blocks are saturated with water and expansion is essentially retained as in the actual case, a very high swelling pressure will arise. The bentonite will be extremely impermeable and thus it will form a barrier against transport of corrosive matters to the canister. The blocks are fabricated by means of cold isostatic pressing of bentonite powder. The base material in the form of powder is enclosed in flexible forms, which are introduced into pressure vessels where the forms are surrounded by oil or water. Thus the powder is compacted into rigid bodies with a bulk density of about 2.2 t/m 3 for ''air dry'' bentonite, which might be compared with a specific density of about 2.7 t/m 3 . The placing of a canister is preceded by piling up bentonite blocks to a level just below the canister lid position, after which the slot around the blocks is filled with bentonite powder. The rest of the blocks are mounted after filling bentonite powder into the inner slot around the canister as well. Finally the storage tunnels will be sealed by filling them with a mixture o02067NRM 0000181 45

Peripheral nerve blocks in pediatric anesthesia

Directory of Open Access Journals (Sweden)

Novaković Dejan

2009-01-01

Full Text Available Introduction Most children undergoing surgery can benefit from regional anesthetic techniques, either as the sole anesthetic regimen or, as usual in pediatric practice, in combination with general anesthesia. The use of peripheral nerve blocks (PNBs in pediatric anesthesia is an effective way to decrease the side-effects and complications associated with central blocks. In spite of their many advantages, including easy performance end efficacy, peripheral nerve blocks are still underused. Objective This article discusses a general approach to PNBs in children and provides data concerning the practice of this regional technique in different age groups. Methods Data from 1,650 procedures were prospectively collected during the period from March 1, 2007 to February 29, 2008. The type of PNB, if any, as well as the patient age were noted. Our patients were divided into four groups: 0-3 years, 4-7 years, 8-12 years and 13-18 years. Results During the investigated period, PNBs as a sole technique or in anesthetized children were performed in 7.45% of cases. Ilioingunal/iliohypogastric nerve block and penile block were the most common (70% of all PNBs distributed mainly among the children between 4-7 years of age (p<0.05. In older children, extremity PNBs predominate in regard to other types of blocks. PNBs are most frequently performed under general anesthesia (85%, so the perineural approach requires a safe technique to avoid nerve damage. Conclusion The observed differences in PNB usage seem to be related to patient age and correlate with common pathology and also with technical availability of PNB performance.

CONJUGATED BLOCK-COPOLYMERS FOR ELECTROLUMINESCENT DIODES

NARCIS (Netherlands)

Hilberer, A; Gill, R.E; Herrema, J.K; Malliaras, G.G; Wildeman, J.; Hadziioannou, G

In this article we review results obtained in our laboratory on the design and study of new light-emitting polymers. We are interested in the synthesis and characterisation of block copolymers with regularly alternating conjugated and non conjugated sequences. The blocks giving rise to luminescence

Superintegrability of d-dimensional conformal blocks

International Nuclear Information System (INIS)

Isachenkov, Mikhail

2016-02-01

We observe that conformal blocks of scalar 4-point functions in a d-dimensional conformal field theory can mapped to eigenfunctions of a 2-particle hyperbolic Calogero-Sutherland Hamiltonian. The latter describes two coupled Poeschl-Teller particles. Their interaction, whose strength depends smoothly on the dimension d, is known to be superintegrable. Our observation enables us to exploit the rich mathematical literature on Calogero-Sutherland models in deriving various results for conformal field theory. These include an explicit construction of conformal blocks in terms of Heckman-Opdam hypergeometric functions and a remarkable duality that relates the blocks of theories in different dimensions.

Superintegrability of d-dimensional conformal blocks

Energy Technology Data Exchange (ETDEWEB)

Isachenkov, Mikhail [Weizmann Institute of Science, Rehovot (Israel). Dept. of Particle Physics and Astronomy; Schomerus, Volker [DESY Theory Group, Hamburg (Germany)

2016-02-15

We observe that conformal blocks of scalar 4-point functions in a d-dimensional conformal field theory can mapped to eigenfunctions of a 2-particle hyperbolic Calogero-Sutherland Hamiltonian. The latter describes two coupled Poeschl-Teller particles. Their interaction, whose strength depends smoothly on the dimension d, is known to be superintegrable. Our observation enables us to exploit the rich mathematical literature on Calogero-Sutherland models in deriving various results for conformal field theory. These include an explicit construction of conformal blocks in terms of Heckman-Opdam hypergeometric functions and a remarkable duality that relates the blocks of theories in different dimensions.

Three-dimensional Reconstruction of Block Shape Irregularity and its Effects on Block Impacts Using an Energy-Based Approach

Science.gov (United States)

Zhang, Yulong; Liu, Zaobao; Shi, Chong; Shao, Jianfu

2018-04-01

This study is devoted to three-dimensional modeling of small falling rocks in block impact analysis in energy view using the particle flow method. The restitution coefficient of rockfall collision is introduced from the energy consumption mechanism to describe rockfall-impacting properties. Three-dimensional reconstruction of falling block is conducted with the help of spherical harmonic functions that have satisfactory mathematical properties such as orthogonality and rotation invariance. Numerical modeling of the block impact to the bedrock is analyzed with both the sphere-simplified model and the 3D reconstructed model. Comparisons of the obtained results suggest that the 3D reconstructed model is advantageous in considering the combination effects of rockfall velocity and rotations during colliding process. Verification of the modeling is carried out with the results obtained from other experiments. In addition, the effects of rockfall morphology, surface characteristics, velocity, and volume, colliding damping and relative angle are investigated. A three-dimensional reconstruction modulus of falling blocks is to be developed and incorporated into the rockfall simulation tools in order to extend the modeling results at block scale to slope scale.

Zero-block mode decision algorithm for H.264/AVC.

Science.gov (United States)

Lee, Yu-Ming; Lin, Yinyi

2009-03-01

In the previous paper , we proposed a zero-block intermode decision algorithm for H.264 video coding based upon the number of zero-blocks of 4 x 4 DCT coefficients between the current macroblock and the co-located macroblock. The proposed algorithm can achieve significant improvement in computation, but the computation performance is limited for high bit-rate coding. To improve computation efficiency, in this paper, we suggest an enhanced zero-block decision algorithm, which uses an early zero-block detection method to compute the number of zero-blocks instead of direct DCT and quantization (DCT/Q) calculation and incorporates two adequate decision methods into semi-stationary and nonstationary regions of a video sequence. In addition, the zero-block decision algorithm is also applied to the intramode prediction in the P frame. The enhanced zero-block decision algorithm brings out a reduction of average 27% of total encoding time compared to the zero-block decision algorithm.

Risking Aggression: Reply to Block

OpenAIRE

Kris Borer

2010-01-01

In his paper, “Is There an ‘Anomalous’ Section of the Laffer Curve?”, Walter Block describes some situations in which it appears that a libertarian should violate the non-aggression principle. To rectify this, Block proposes a different perspective on libertarianism which he calls punishment theory. This paper argues that no new theory is needed, as the non-aggression principle can be used to resolve theapparent conundrums.

Regional anesthesia in transurethral resection of prostate (TURP surgery: A comparative study between saddle block and subarachnoid block

Directory of Open Access Journals (Sweden)

Susmita Bhattacharyya

2015-01-01

Full Text Available Background: Spinal anesthesia is the technique of choice in transurethral resection of prostate (TURP. The major complication of spinal technique is risk of hypotension. Saddle block paralyzed pelvic muscles and sacral nerve roots and hemodynamic derangement is less. Aims and objectives: To compare the hemodynamic changes and adequate surgical condition between saddle block and subarachnoid block for TURP. Material and methods: Ninety patients of aged between 50 to 70 years of ASA-PS I, II scheduled for TURP were randomly allocated into 2 groups of 45 in each group. Group A patients were received spinal (2 ml of hyperbaric bupivacaine and Group B were received saddle block (2 ml of hyperbaric bupivacaine. Baseline systolic, diastolic and mean arterial pressure, heart rate, oxygen saturation were recorded and measured subsequently. The height of block was noted in both groups. Hypotension was corrected by administration of phenylephrine 50 mcg bolus and total requirement of vasopressor was noted. Complications (volume overload, TURP syndrome etc. were noted. Results: Incidence of hypotension and vasopressor requirement was less (P < 0.01 in Gr B patients.Adequate surgical condition was achieved in both groups. There was no incidence of volume overload, TURP syndrome, and bladder perforation. Conclusion: TURP can be safely performed under saddle block without hypotension and less vasopressor requirement.

21 CFR 882.1925 - Ultrasonic scanner calibration test block.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ultrasonic scanner calibration test block. 882... Ultrasonic scanner calibration test block. (a) Identification. An ultrasonic scanner calibration test block is a block of material with known properties used to calibrate ultrasonic scanning devices (e.g., the...

Thermal-stress analysis of HTGR fuel and control rod fuel blocks in in-block carbonization and annealing furnace

International Nuclear Information System (INIS)

Gwaltney, R.C.; McAfee, W.J.

1977-01-01

A new method for performing thermal stress analyses in structures with multiple penetrations was applied to these analyses. This method couples the development of an equivalent thermal conductivity for the blocks, a technique that has been used extensively for modeling the thermal characteristics of reactor cores, with the use of the equivalent solid plate method for stress analysis. Using this equivalent thermal conductivity, which models as one material the heat transfer characteristics of the fuel, coolant, and graphite two-dimensional, steady-state thermal analyses of the fuel and control rod fuel blocks were performed to establish all temperature boundaries required for the stress analyses. In applying the equivalent solid plate method, the region of penetrations being modeled was replaced by a pseudo material having the same dimensions but whose materials properties were adjusted to account for the penetration. The peak stresses and strains were determined by applying stress and strain intensification factors to the calculated distributions. The condition studied was where the blocks were located near the center of the furnace. In this position, the axial surface of the block is heated near one end and cooled near the other. The approximate axial surface temperatures ranged from 1521 0 C at both the heated and the cooled ends to a peak of 1800 0 C near the center. Five specific cases were analyzed: plane (two-dimensional thermal, plane stress strain) analyses of each end of a standard fuel block (2 cases), plane analyses of each end of a control rod fuel block (2 cases), and a two-dimensional analysis of a fuel block treated as an axisymmetric cylind

Block Gas Sol Unit in Haderslev

DEFF Research Database (Denmark)

Vejen, Niels Kristian

2000-01-01

Investigation of a SDHW system based on a Block Gas Sol Unit from Baxi A/S installed by a consumer i Haderslev, Denmark.......Investigation of a SDHW system based on a Block Gas Sol Unit from Baxi A/S installed by a consumer i Haderslev, Denmark....

Secure Block Ciphers - Cryptanalysis and Design

DEFF Research Database (Denmark)

Tiessen, Tyge

be applied to the AES can be transferred to this block cipher, albeit with a higher attack complexity. The second publication introduces a new block cipher family which is targeted for new applications in fully homomorphic encryption and multi-party computation. We demonstrate the soundness of the design...... is encrypted using so-called symmetric ciphers. The security of our digital infrastructure thus rests at its very base on their security. The central topic of this thesis is the security of block ciphers – the most prominent form of symmetric ciphers. This thesis is separated in two parts. The first part...... is an introduction to block ciphers and their cryptanalysis, the second part contains publications written and published during the PhD studies. The first publication evaluates the security of a modification of the AES in which the choice of S-box is unknown to the attacker. We find that some of the attacks that can...

Transversus abdominis plane block vs. wound infiltration in Caesarean section: a randomised controlled trial.

Science.gov (United States)

Telnes, A; Skogvoll, E; Lonnée, H

2015-04-01

Multiple studies suggest that transversus abdominis plane (TAP) block (without intrathecal morphine) after Caesarean section (CS) reduces post-operative morphine consumption. In our study, we wanted to compare the analgesic effect of TAP block with infiltration of the wound after CS. We included 60 pregnant women scheduled for elective CS under spinal anaesthesia in a randomised, single-centre, double-blind study. Thirty patients received ultrasound-guided TAP block using 20 ml bupivacaine 0.25% with adrenaline 5 μg/ml bilaterally and 20 ml normal saline as wound infiltration (TAP group). The other 30 patients (the control group) received normal saline 20 ml bilaterally in the TAP, and 20 ml bupivacaine 0.25% with adrenaline 5 μg/ml as wound infiltration. The main outcome was cumulative morphine consumption at 48 h after surgery. In addition, continuous morphine consumption, pain scores and side effects were registered. Fifty-seven patients completed the study. Cumulative morphine consumption at 48 h (mean±standard deviation) was 41±34 mg in the TAP group and 38±27 mg in the control group (P=0.7); a difference of 3 mg (95% confidence interval -13 to 19 mg). Morphine consumption at any time up to 48 h was virtually identical in both groups. Side effects were similar, except for a higher degree of sedation in the TAP group (P=0.04). Compared with wound infiltration with local anaesthetics, TAP block did not reduce cumulative morphine consumption following CS. The TAP block was associated with more pronounced sedation. © 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

RADIOMETRIC BLOCK ADJUSMENT AND DIGITAL RADIOMETRIC MODEL GENERATION

Directory of Open Access Journals (Sweden)

A. Pros

2013-05-01

Full Text Available In this paper we present a radiometric block adjustment method that is related to geometric block adjustment and to the concept of a terrain Digital Radiometric Model (DRM as a complement to the terrain digital elevation and surface models. A DRM, in our concept, is a function that for each ground point returns a reflectance value and a Bidirectional Reflectance Distribution Function (BRDF. In a similar way to the terrain geometric reconstruction procedure, given an image block of some terrain area, we split the DRM generation in two phases: radiometric block adjustment and DRM generation. In the paper we concentrate on the radiometric block adjustment step, but we also describe a preliminary DRM generator. In the block adjustment step, after a radiometric pre-calibraton step, local atmosphere radiative transfer parameters, and ground reflectances and BRDFs at the radiometric tie points are estimated. This radiometric block adjustment is based on atmospheric radiative transfer (ART models, pre-selected BRDF models and radiometric ground control points. The proposed concept is implemented and applied in an experimental campaign, and the obtained results are presented. The DRM and orthophoto mosaics are generated showing no radiometric differences at the seam lines.

Pre-operative brachial plexus block compared with an identical block performed at the end of surgery: a prospective, double-blind, randomised clinical trial.

Science.gov (United States)

Holmberg, A; Sauter, A R; Klaastad, Ø; Draegni, T; Raeder, J C

2017-08-01

We evaluated whether pre-emptive analgesia with a pre-operative ultrasound-guided infraclavicular brachial plexus block resulted in better postoperative analgesia than an identical block performed postoperatively. Fifty-two patients undergoing fixation of a fractured radius were included. All patients received general anaesthesia with remifentanil and propofol. Patients were randomly allocated into two groups: a pre-operative block or a postoperative block with 0.5 ml.kg -1 ropivacaine 0.75%. After surgery, all patients received regular paracetamol plus opioids for breakthrough pain. Mean (SD) time to first rescue analgesic after emergence from general anaesthesia was 544 (217) min in the pre-operative block group compared with 343 (316) min in the postoperative block group (p = 0.015). Postoperative pain scores were higher and more patients required rescue analgesia during the first 4 h after surgery in the postoperative block group. There were no significant differences in plasma stress mediators between the groups. Analgesic consumption was lower at day seven in the pre-operative block group. Pain was described as very strong at block resolution in 27 (63%) patients and 26 (76%) had episodes of mild pain after 6 months. We conclude that a pre-operative ultrasound-guided infraclavicular brachial plexus block provides longer and better analgesia in the acute postoperative period compared with an identical postoperative block in patients undergoing surgery for fractured radius. © 2017 The Association of Anaesthetists of Great Britain and Ireland.

A fast direct method for block triangular Toeplitz-like with tri-diagonal block systems from time-fractional partial differential equations

Science.gov (United States)

Ke, Rihuan; Ng, Michael K.; Sun, Hai-Wei

2015-12-01

In this paper, we study the block lower triangular Toeplitz-like with tri-diagonal blocks system which arises from the time-fractional partial differential equation. Existing fast numerical solver (e.g., fast approximate inversion method) cannot handle such linear system as the main diagonal blocks are different. The main contribution of this paper is to propose a fast direct method for solving this linear system, and to illustrate that the proposed method is much faster than the classical block forward substitution method for solving this linear system. Our idea is based on the divide-and-conquer strategy and together with the fast Fourier transforms for calculating Toeplitz matrix-vector multiplication. The complexity needs O (MNlog2 ⁡ M) arithmetic operations, where M is the number of blocks (the number of time steps) in the system and N is the size (number of spatial grid points) of each block. Numerical examples from the finite difference discretization of time-fractional partial differential equations are also given to demonstrate the efficiency of the proposed method.

Robust and Adaptive Block Tracking Method Based on Particle Filter

Directory of Open Access Journals (Sweden)

Bin Sun

2015-10-01

Full Text Available In the field of video analysis and processing, object tracking is attracting more and more attention especially in traffic management, digital surveillance and so on. However problems such as objects’ abrupt motion, occlusion and complex target structures would bring difficulties to academic study and engineering application. In this paper, a fragmentsbased tracking method using the block relationship coefficient is proposed. In this method, we use particle filter algorithm and object region is divided into blocks initially. The contribution of this method is that object features are not extracted just from a single block, the relationship between current block and its neighbor blocks are extracted to describe the variation of the block. Each block is weighted according to the block relationship coefficient when the block is voted on the most matched region in next frame. This method can make full use of the relationship between blocks. The experimental results demonstrate that our method can provide good performance in condition of occlusion and abrupt posture variation.

BCYCLIC: A parallel block tridiagonal matrix cyclic solver

Science.gov (United States)

Hirshman, S. P.; Perumalla, K. S.; Lynch, V. E.; Sanchez, R.

2010-09-01

A block tridiagonal matrix is factored with minimal fill-in using a cyclic reduction algorithm that is easily parallelized. Storage of the factored blocks allows the application of the inverse to multiple right-hand sides which may not be known at factorization time. Scalability with the number of block rows is achieved with cyclic reduction, while scalability with the block size is achieved using multithreaded routines (OpenMP, GotoBLAS) for block matrix manipulation. This dual scalability is a noteworthy feature of this new solver, as well as its ability to efficiently handle arbitrary (non-powers-of-2) block row and processor numbers. Comparison with a state-of-the art parallel sparse solver is presented. It is expected that this new solver will allow many physical applications to optimally use the parallel resources on current supercomputers. Example usage of the solver in magneto-hydrodynamic (MHD), three-dimensional equilibrium solvers for high-temperature fusion plasmas is cited.

Peripheral nerve blocks in patients with Ehlers-Danlos syndrome, hypermobility type: a report of 2 cases.

Science.gov (United States)

Patzkowski, Michael S

2016-03-01

Ehlers-Danlos syndrome is an inherited disorder of collagen production that results in multiorgan dysfunction. Patients with hypermobility type display skin hyperextensibility and joint laxity, which can result in chronic joint instability, dislocation, peripheral neuropathy, and severe musculoskeletal pain. A bleeding diathesis can be found in all subtypes of varying severity despite a normal coagulation profile. There have also been reports of resistance to local anesthetics in these patients. Several sources advise against the use of regional anesthesia in these patients citing the 2 previous features. There have been reports of successful neuraxial anesthesia, but few concerning peripheral nerve blocks, none of which describe nerves of the lower extremity. This report describes 2 cases of successful peripheral regional anesthesia in the lower extremity. In case 1, a 16-year-old adolescent girl with hypermobility type presented for osteochondral grafting of tibiotalar joint lesions. She underwent a popliteal sciatic (with continuous catheter) and femoral nerve block under ultrasound guidance. She proceeded to surgery and tolerated the procedure under regional block and intravenous sedation. She did not require any analgesics for the following 15 hours. In case 2, an 18-year-old woman with hypermobility type presented for medial patellofemoral ligament reconstruction for chronic patella instability. She underwent a saphenous nerve block above the knee with analgesia in the distribution of the saphenous nerve lasting for approximately 18 hours. There were no complications in either case. Prohibitions against peripheral nerve blocks in patients with Ehlers-Danlos syndrome, hypermobility type, appear unwarranted. Published by Elsevier Inc.

The Building Blocks for JWST I and T (Integrations and Test) to Operations - From Simulator to Flight Units

Science.gov (United States)

Fatig, Curtis; Ochs, William; Johns, Alan; Seaton, Bonita; Adams, Cynthia; Wasiak, Francis; Jones, Ronald; Jackson, Wallace

2012-01-01

The James Webb Space Telescope (JWST) Project has an extended integration and test (I&T) phase due to long procurement and development times of various components as well as recent launch delays. The JWST Ground Segment and Operations group has developed a roadmap of the various ground and flight elements and their use in the various JWST I&T test programs. The JWST Project s building block approach to the eventual operational systems, while not new, is complex and challenging; a large-scale mission like JWST involves international partners, many vendors across the United States, and competing needs for the same systems. One of the challenges is resource balancing so simulators and flight products for various elements congeal into integrated systems used for I&T and flight operations activities. This building block approach to an incremental buildup provides for early problem identification with simulators and exercises the flight operations systems, products, and interfaces during the JWST I&T test programs. The JWST Project has completed some early I&T with the simulators, engineering models and some components of the operational ground system. The JWST Project is testing the various flight units as they are delivered and will continue to do so for the entire flight and operational system. The JWST Project has already and will continue to reap the value of the building block approach on the road to launch and flight operations.

Risking Aggression: Reply to Block

Directory of Open Access Journals (Sweden)

Kris Borer

2010-05-01

Full Text Available In his paper, “Is There an ‘Anomalous’ Section of the Laffer Curve?”, Walter Block describes some situations in which it appears that a libertarian should violate the non-aggression principle. To rectify this, Block proposes a different perspective on libertarianism which he calls punishment theory. This paper argues that no new theory is needed, as the non-aggression principle can be used to resolve theapparent conundrums.

Patchy micelles based on coassembly of block copolymer chains and block copolymer brushes on silica particles.

Science.gov (United States)

Zhu, Shuzhe; Li, Zhan-Wei; Zhao, Hanying

2015-04-14

Patchy particles are a type of colloidal particles with one or more well-defined patches on the surfaces. The patchy particles with multiple compositions and functionalities have found wide applications from the fundamental studies to practical uses. In this research patchy micelles with thiol groups in the patches were prepared based on coassembly of free block copolymer chains and block copolymer brushes on silica particles. Thiol-terminated and cyanoisopropyl-capped polystyrene-block-poly(N-isopropylacrylamide) block copolymers (PS-b-PNIPAM-SH and PS-b-PNIPAM-CIP) were synthesized by reversible addition-fragmentation chain transfer polymerization and chemical modifications. Pyridyl disulfide-functionalized silica particles (SiO2-SS-Py) were prepared by four-step surface chemical reactions. PS-b-PNIPAM brushes on silica particles were prepared by thiol-disulfide exchange reaction between PS-b-PNIPAM-SH and SiO2-SS-Py. Surface micelles on silica particles were prepared by coassembly of PS-b-PNIPAM-CIP and block copolymer brushes. Upon cleavage of the surface micelles from silica particles, patchy micelles with thiol groups in the patches were obtained. Dynamic light scattering, transmission electron microscopy, and zeta-potential measurements demonstrate the preparation of patchy micelles. Gold nanoparticles can be anchored onto the patchy micelles through S-Au bonds, and asymmetric hybrid structures are formed. The thiol groups can be oxidized to disulfides, which results in directional assembly of the patchy micelles. The self-assembly behavior of the patchy micelles was studied experimentally and by computer simulation.

Fabrication of calcite blocks from gypsum blocks by compositional transformation based on dissolution-precipitation reactions in sodium carbonate solution.

Science.gov (United States)

Ishikawa, Kunio; Kawachi, Giichiro; Tsuru, Kanji; Yoshimoto, Ayami

2017-03-01

Calcium carbonate (CaCO 3 ) has been used as a bone substitute, and is a precursor for carbonate apatite, which is also a promising bone substitute. However, limited studies have been reported on the fabrication of artificial calcite blocks. In the present study, cylindrical calcite blocks (ϕ6×3mm) were fabricated by compositional transformation based on dissolution-precipitation reactions using different calcium sulfate blocks as a precursor. In the dissolution-precipitation reactions, both CaSO 4 ·2H 2 O and CaSO 4 transformed into calcite, a polymorph of CaCO 3 , while maintaining their macroscopic structure when immersed in 1mol/L Na 2 CO 3 solution at 80°C for 1week. The diametral tensile strengths of the calcite blocks formed using CaSO 4 ·2H 2 O and CaSO 4 were 1.0±0.3 and 2.3±0.7MPa, respectively. The fabrication of calcite blocks using CaSO 4 ·2H 2 O and CaSO 4 proposed in this investigation may be a useful method to produce calcite blocks because of the self-setting ability and high temperature stability of gypsum precursors. Copyright © 2016 Elsevier B.V. All rights reserved.

Spectral flow and conformal blocks in AdS{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Cagnacci, Yago [Instituto de Astronomía y Física del Espacio (IAFE, CONICET-UBA),Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina); Iguri, Sergio M. [Instituto de Astronomía y Física del Espacio (IAFE, CONICET-UBA),Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina); Institut de Physique Théorique, CEA/Saclay,91191 Gif-sur-Yvette Cedex (France)

2015-09-08