42 research outputs found

    Studying the Effect of Aluminum Powder Addition on Dielectric Behavior of Polyester Composite Materials

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    The effect of both weight fraction of aluminium and frequency on dielectric properties of Al- powder reinforced polyester composite materials were investigated. We study the dielectric behaviour of composite materials reinforced with (0, 5, 15, 30 &45) weight fraction of Al and frequency ranges (50-106) Hz at room temperature. The results show the dielectric constant and dielectric losses factor were increased with increasing in weight fraction of aluminium due to high conductivity of aluminium. The decrease in the dielectric constant and dielectric losses with higher frequencies can be explained by the fact that as the frequency increases, the interfacial dipoles have less time to orient themselves in the direction of the alternating field

    EFFECT OF USING BASIC EXERCISE WITH AN INNOVATIVE DEVICE TO IMPROVE PERFORMANCE IN WEIGHT PUSHING AND ACHIEVEMENT FOR SPECIAL OLYMPICS ATHLETES

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    هدفت هذه الدراسة إلىابتكار جهاز يحافظ على بقاء المرفق عالياً عند اداء مرحلة الرمي لذوي الاعاقة العقلية البسيطة بدفع الثقل، واستخدام الجهاز المبتكر في تمرينات تحسين التعلم لذوي الاعاقة العقلية البسيطة بمرحلة الرمي لدفع الثقل، معرفة تأثير استخدام الجهاز المبتكر في تحسين اداء مرحلة الرمي والانجاز لذوي الاعاقة العقلية البسيطة بدفع الثقل. افترض الباحثون تحسين اداء مرحلة الرمي وانجار ذوي الاعاقة العقلية البسيطة بدفع الثقل واستمرت التجربة الرئيسة(8) اسابيع بمعدل(4) وحدات تعليمية وضعت من قبل المدرب ووضع الباحثون الجهاز المبتكر تحت تصرف المدرب لاستخدامه في الوحدات التعليمية المطبقة على الافراد من ذوي الاعاقة العقلية البسيطة كتعويض عن نظرية التعلم بالعمل. توصل الباحثون إلىعدة استنتاجات اهمها تحسين اداء مرحلة الرمي والانجاز لذوي الاعاقة العقلية البسيطة بدفع الثقل وأوصى الباحثون بضرورة استثمار الجهاز المبتكر في تحسين اداء مرحلة الرمي للاطفال الاصحاء ولذوي الاعاقات الاخرى بدفع الثقل.The aim of this study was to an innovate a device to keep the elbow high when throwing the weight for athletes with intellectual disability, and using the innovate device in exercises to improve learning abilities for intellectual disability at the phase of weight pushing and to know the effect of the innovate device. The researchers hypothesized improvement of the performance at throwing phase and the achievement of persons with intellectual disabilities. The main experimental lasted (8) weeks with an average of( 4) training units every week used from the coach as compensation for work learning theory. The researcher found improvement of performance for persons with intellectual disabilities in the throwing phase. The researchers recommend to invest the device used in improving the performance of the throwing phase for persons with and without disabilities

    Surgical Management of Lumbar Spine Fractures and Dislocations

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    Background: Lumbar spine fractures and dislocations, which are part of the thoracolumbar region, are critical injuries with significant morbidity. The epidemiological shift in the median age of injury and the high prevalence of these injuries, particularly in the T10-L2 region, highlight the necessity for effective therapeutic interventions. With advancements in spine biomechanics, imaging technologies, and surgical techniques, there has been a paradigm shift from conservative to surgical management, though high-quality comparative studies remain limited. Objective: To synthesize recent data on the epidemiology, evaluation, and management of lumbar spine fractures and dislocations, and to elucidate the comparative efficacy of surgical interventions and conservative approaches in optimizing patient outcomes. Method: This paper conducts a comprehensive review of epidemiological data on thoracolumbar traumatic injuries, diagnostic techniques, and management strategies, especially focusing on surgical interventions. The review also details specific surgical techniques utilized for lumbar spine fractures and their underlying rationale. Findings and Conclusion: Thoracolumbar injuries primarily affect the transitional zone (T11-L2) and show a higher incidence in males aged between 20 and 40. Imaging, especially CT scans, offers a definitive diagnostic approach, with MRI providing insights on soft tissue interactions. While historically, conservative methods dominated therapeutic interventions, surgical techniques, including Posterior Instrumentation, Anterior Lumbar Interbody Fusion (ALIF), Transforaminal Lumbar Interbody Fusion (TLIF), and Posterior Lumbar Interbody Fusion (PLIF), are increasingly being utilized. Some specific fractures even warrant a combined posterior-anterior surgical approach. Notably, certain case studies highlight the potential for superior outcomes with surgical intervention, even in the absence of neurological deficits. Selecting the appropriate management strategy should be tailored to individual patient factors, nature of the injury, and available expertise and resources

    Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

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    The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

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    AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Timing of surgery following SARS-CoV-2 infection: an international prospective cohort study.

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    Peri-operative SARS-CoV-2 infection increases postoperative mortality. The aim of this study was to determine the optimal duration of planned delay before surgery in patients who have had SARS-CoV-2 infection. This international, multicentre, prospective cohort study included patients undergoing elective or emergency surgery during October 2020. Surgical patients with pre-operative SARS-CoV-2 infection were compared with those without previous SARS-CoV-2 infection. The primary outcome measure was 30-day postoperative mortality. Logistic regression models were used to calculate adjusted 30-day mortality rates stratified by time from diagnosis of SARS-CoV-2 infection to surgery. Among 140,231 patients (116 countries), 3127 patients (2.2%) had a pre-operative SARS-CoV-2 diagnosis. Adjusted 30-day mortality in patients without SARS-CoV-2 infection was 1.5% (95%CI 1.4-1.5). In patients with a pre-operative SARS-CoV-2 diagnosis, mortality was increased in patients having surgery within 0-2 weeks, 3-4 weeks and 5-6 weeks of the diagnosis (odds ratio (95%CI) 4.1 (3.3-4.8), 3.9 (2.6-5.1) and 3.6 (2.0-5.2), respectively). Surgery performed ≥ 7 weeks after SARS-CoV-2 diagnosis was associated with a similar mortality risk to baseline (odds ratio (95%CI) 1.5 (0.9-2.1)). After a ≥ 7 week delay in undertaking surgery following SARS-CoV-2 infection, patients with ongoing symptoms had a higher mortality than patients whose symptoms had resolved or who had been asymptomatic (6.0% (95%CI 3.2-8.7) vs. 2.4% (95%CI 1.4-3.4) vs. 1.3% (95%CI 0.6-2.0), respectively). Where possible, surgery should be delayed for at least 7 weeks following SARS-CoV-2 infection. Patients with ongoing symptoms ≥ 7 weeks from diagnosis may benefit from further delay

    69. Does pulmonary hypertension affect outcome after mitral valve surgery

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    Pulmonary hypertension (PH) due to left heart disease (LHD) is the most common form of pulmonary hypertension. We know from previous studies that PH in patients with LHD is associated with poor prognosis. Regarding incidence and prevalence of PH associated with mitral valve disease we have different data depending of study population. The purpose of this study was to evaluate effects of pulmonary hypertension on short and long term survival following mitral valve surgery at KFSH&RC. Methods: Retrospective study of all patients who have undergone mitral valve (MV) surgery since January 2010 until December 2011 with follow up to December 2013. Pulmonary artery pressure was assessed by Doppler echocardiography pre- and postoperatively. The impact of pulmonary hypertension (PASp ⩾ 50 mm Hg) on early (30 days) and late outcomes and duration of hospital stay was analyzed. Results: During the period of 2 years 233 patients (63% female) with mean age 45 ± 14 (range 19–83 years) underwent MV surgery. Mean follow up was 2.8 ± 0.97 years. Main indication for MV surgery was rheumatic valve disease (83%). Isolated MV surgery has been performed in 130 patients and combine valve surgery in 103 patients. Mortality was significantly higher after combine valve surgery (p = 0.028). Primary valve surgery has been done in 162 cases and re-do surgery in 71 cases. Interesting, there were no difference in survival between these two groups (p = 0.88). There were no significant difference in survival after MV replacement (n = 195) and MV repair (n = 38; p = 0.18). Pulmonary hypertension was present in 115 (51%) patients. Duration of hospitalization stay after valve surgery was almost twofold longer in patients with PH (24 ± 48 vs.13 ± 14 days, p = 0.02). Patients died within 30 days had a significantly higher PASp (64 ± 30 vs. 48 ± 17 mmHg; p = 0.003). We found a clear tendency to higher mortality in patients with pulmonary hypertension. Conclusions: Pulmonary hypertension clearly affects early and late survival after MV surgery. Better survival and shorter duration of hospital stay in patients without PH supports early admission for MV surgery before occurrence of PH
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