Experimental and Numerical Investigation of Creep Behavior In Isotropic Composites

Creep testing is an important part of the characterization of composite materials. It is crucial to determine long-term deflection levels and time-to-failure for these advanced materials. The work is carried out to investigate creep behavior on isotropic composite columns. Isotropy property was obtained by making a new type of composite made from a paste of particles of carbon fibers mixed with epoxy resin and E-glass particles mixed with epoxy resin. This type of manufacturing process can be called the compression mold composite or the squeeze mold composite. Experimental work was carried out with changing the fiber concentration (30, 40 and 50% mass fraction), cross section shape, and type of composite. The creep results showed that the higher the fiber concentration, the more the creep resistance. Type of fiber plays a very critical role, where carbon/epoxy composite showed much higher creep resistance and also showed much higher modulus of elasticity than the E-glass/epoxy composite. Specimen shape factor noticed to play a very small role. However, square cross sectional area showed slightly higher resistance for creep than the rectangular cross sectional area. This difference is not critical and can be ignored. F.E.M simulation with ANSYS Inc. software was implied and results were compatible with the experimental work with a maximum discrepancy of (17.24%)

Standerd cervical mediastinoscopy in the diagnosis of mediastinal mass in Ghazi Al-Hariri Hospital

Background: Mediastinoscopy is an integral part in the diagnosis of mediastinal mass. The most common indications for mediastinoscopy is for tissue sampling and determining the extent of lung cancer. Objectives: To validate our experience with standard cervical mediastinoscopy and to evaluate the usefulness of cervical mediastinoscopy in the assessing the mediastinal diseases when imaging modalities are none diagnostic. Material and Methods: A retrospective study of 16 patients between January 2012 and July 2014. Mediastinoscopy was indicated for diagnostic staging of nodal disease related to lung cancer in 8 patients (group I) and for isolated mediastinal lymphadenopathy in 8 patients (group II) Results: There were 11 males and 5 females, with a mean age of 47 years. The mean operative time was 30 minutes and the mean hospital stay was 8 hours. In lung cancer (group I) there was positive results in 3 patients and negative results in 5 patients. In patients with isolated mediastinal lymphadenopathy (group II), TB was the commonest diagnosis. There was no surgical related morbidity or mortality in our study. The sensitivity and specificity of standard cervical mediastinoscopy in this study was 100% Conclusion: Standard cervical mediastinoscopy is safe in the hands of well trained persons and needs a good knowledge of the anatomy of the region, cost effective, highly specific and still the first investigation of choice in the diagnosis of mediastinal nodal involvement

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Effectiveness of peer-assisted teaching of medical English skills to non-native English-speaking medical students [version 2; peer review: 2 approved]

Background Peer-assisted learning has been shown to be constructive in numerous aspects of undergraduate medical education. The purpose of this study was to evaluate the effectiveness of peer-assisted teaching of medical English skills to non-native English-speaking students. Methods A medical English conversation course was conducted at Damascus University by a group of students. Targeted participants were intermediate level fellow students from the same program. A longitudinal study was carried out between 1st to 31st March 2019 to assess changes in self-assessment of English language skills among course participants. Pre- and post-course appraisal involved a review of previous experience with medical English language, a self-assessment of five English language skills, and an objective measurement of medical English knowledge. In addition, participants were requested to respond to a set of statements related to the importance and the usefulness of peer-assisted teaching of medical English skills. Paired-sample Student t-test was used to compare pre- and post-course appraisal results. Results 42 students attended the course and completed pre- and post-course appraisals in full. Data analyses showed a statistically significant increase in participants’ confidence in speaking medical English in public (p<0.001) and using English in various medical settings (presenting and discussing cases, writing clinical reports, interviewing patients and reading English medical texts). Objective measurements of medical English knowledge confirmed a significant increase in participants’ knowledge of methods of administration of therapeutics, knowledge of human body parts in English and familiarity with English medical abbreviations. Most participants agreed that peer-education was effective in teaching medical English skills to non-native English-speaking students and in increasing their confidence when using English in real-life medical scenarios. Conclusions The present study highlights the effectiveness of peer-assisted teaching of medical English skills to non-native English-speaking medical students. Further validation is required and should compare the effectiveness of traditional versus peer-assisted teaching approaches

Implementation of enhanced recovery after surgery for pancreatoduodenectomy increases the proportion of patients achieving textbook outcome: A retrospective cohort study

Background: Enhanced Recovery After Surgery (ERAS) for patients undergoing pancreatoduodenectomy is associated with reduced length of stay (LOS) and morbidity. However, external validating of the impact is difficult due to the multimodal aspects of ERAS. This study aimed to assess implementation of ERAS for pancreatoduodenectomy with a composite measure of multiple ideal outcome indicators defined as 'textbook outcome' (TBO).Methods: In a tertiary referral center, 250 patients undergoing pancreatoduodenectomy were included in ERAS (May 2012-January 2017) and compared to a cohort of 125 patients undergoing traditional perioperative management (November 2009-April 2012). TBO was defined as proportion of patients without prolonged LOS, Clavien-Dindo >= III complications, postoperative pancreatic fistula, postpancreatectomy hemorrhage, bile leakage, readmissions or 30-day/in-hospital mortality. Additionally, overall treatment costs were calculated and compared using bootstrap independent t-test.Results: The two cohorts were comparable in terms of demographic and surgical details. Implementation of ERAS was associated with reduced median LOS (10 days vs 13 days, p < 0.001) and comparable overall complication rate (62.0% vs 61.6%, p = 0.940) when compared to the traditional management group. In addition, a higher proportion of patients achieved TBO (56.4% vs 44.0%, p = 0.023) when treated according to ERAS principles. Furthermore, ERAS was associated with reduced mean total costs (18132 pound vs 19385 pound, p < 0.005).Conclusion: Implementation of ERAS for patients undergoing pancreatoduodenectomy is beneficial for both patients and hospitals. ERAS increased the proportion of patients achieving TBO and reduced overall costs. TBO is a potential measure for the evaluation of ERAS. Crown Copyright (c) 2020 Published by Elsevier B.V. on behalf of IAP and EPC. All rights reserved

Implementation of enhanced recovery after surgery for pancreatoduodenectomy increases the proportion of patients achieving textbook outcome: A retrospective cohort study

Background: Enhanced Recovery After Surgery (ERAS) for patients undergoing pancreatoduodenectomy is associated with reduced length of stay (LOS) and morbidity. However, external validating of the impact is difficult due to the multimodal aspects of ERAS. This study aimed to assess implementation of ERAS for pancreatoduodenectomy with a composite measure of multiple ideal outcome indicators defined as ‘textbook outcome’ (TBO). Methods: In a tertiary referral center, 250 patients undergoing pancreatoduodenectomy were included in ERAS (May 2012–January 2017) and compared to a cohort of 125 patients undergoing traditional perioperative management (November 2009–April 2012). TBO was defined as proportion of patients without prolonged LOS, Clavien-Dindo ≥ III complications, postoperative pancreatic fistula, postpancreatectomy hemorrhage, bile leakage, readmissions or 30-day/in-hospital mortality. Additionally, overall treatment costs were calculated and compared using bootstrap independent t-test. Results: The two cohorts were comparable in terms of demographic and surgical details. Implementation of ERAS was associated with reduced median LOS (10 days vs 13 days, p < 0.001) and comparable overall complication rate (62.0% vs 61.6%, p = 0.940) when compared to the traditional management group. In addition, a higher proportion of patients achieved TBO (56.4% vs 44.0%, p = 0.023) when treated according to ERAS principles. Furthermore, ERAS was associated with reduced mean total costs (£18132 vs £19385, p < 0.005). Conclusion: Implementation of ERAS for patients undergoing pancreatoduodenectomy is beneficial for both patients and hospitals. ERAS increased the proportion of patients achieving TBO and reduced overall costs. TBO is a potential measure for the evaluation of ERAS

Performance and oncologic safety of sentinel lymph node biopsy after neoadjuvant chemotherapy: Results from a tertiary care center in Lebanon

Abstract Background The feasibility of sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NACT) in initially node‐positive patients is still controversial. We aim to evaluate the oncologic outcomes of SLNB after NACT and further compare the results between those who were initially node‐negative and node‐positive. Methods This is a retrospective cohort that included patients diagnosed with invasive breast cancer and had surgical management between January 2010 and December 2016. Survival and recurrence data after 3–5 years were collected from patients' records. We divided patients into Group A who were initially node‐negative and had SLNB ± axillary lymph node dissection (ALND) and Group B who were node‐positive and had SLNB ± ALND. Results Among initially node‐negative patients, 43 out of 63 patients did SLNB (Group A). However, among initially node‐positive patients only 28 out of 123 patients did SLNB (Group B). Out of the 71 patients who did SLNB after NACT, 26 patients had positive SLNs with only 14 patients who further underwent ALND. The identification rate of SLNB was 100% in Group A and 96.4% in Group B. The survival curves by nodal status showed no significant difference between overall survival and recurrence‐free survival at 5 years between patients in Group A versus Group. Conclusion The results suggest that in properly selected patients, SLNB can be feasible after NACT. Our results resemble the reported literature on accuracy of SLNB after NACT and adds to the growing pool of data on this topic

Prolonged Intragastric Drug Delivery Mediated by Eudragit®E-Carrageenan Polyelectrolyte Matrix Tablets

Interpolyelectrolyte (IPE) complexation between carrageenan (CG) and Eudragit E (EE) was studied in 0.1 M HCl and was used to develop floating matrix tablets aimed to prolong gastric-residence time and sustain delivery of the loaded drug. The optimum EE/CG IPE complexation weight ratio (0.6) was determined in 0.1 M HCl using apparent viscosity measurements. The IPE complex was characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry. Metronidazole matrix tablets were prepared by direct compression using EE, CG, or hybrid EE/CG with ratio optimal for IPE complexation. Corresponding effervescent tablets were prepared by including Na bicarbonate as an effervescent agent. Tablets were evaluated for in vitro buoyancy and drug release in 0.1 M HCl. Both CG and EE–CG effervescent matrices (1:2 drug to polymer weight ratio, 60 mg Na bicarbonate) achieved fast and prolonged floating with floating lag times less than 30 s and floating duration of more than 10 h. The corresponding EE effervescent matrices showed delayed floating and rapid drug release, and completely dissolved after 3 h of dissolution. CG matrices showed an initial burst drug release (48.3 ± 5.0% at 1 h) followed by slow drug release over 8 h. EE–CG matrices exhibited sustained drug release in almost zero-order manner for 10 h (68.2 ± 6.6%). The dissolution data of these matrices were fitted to different dissolution models. It was found that drug release followed zero-order kinetics and was controlled by the superposition of the diffusion and erosion