Preparation ,Characterization and Thermal Properties of New Aromatic Polyester Based on Di ,Tri and Tetra Hydroxyl Monomers with 4,4Azo Di Benzoic Acid and Adipic Acid

A series of new aromatic Polyesters were  synthesized by  polycondensation of various aromatic monomers  di ,tri and tetra diols (BCAHPMNM , BHPMB, BHPPB , BPBHP) with Acids(4,4Azo Di benzoic acid  and Adipic acid) using  dibutyltine dilaurate as Catalyst .all polyesters(P.E1-P.E4)containing pyridine heterocyclic group, aliphatic methylene linkage, and Azo group. The yield of Polyesters varies from 60-85%. All of  these  new  aromatic polyester  show very good  solubility in common organic  solvents , such as (pyridine , CHCl3 ,  CH2Cl2 , NaOH , H2SO4 , HNO3 , Acetone , Benzene ,  DMF , DMSO , THF) without need for heating. Thermal analysis of polyesters by thermo gravimetric analysis (TGA) reveals that these Aromatic polyesters possess thermal stability. Monomers and polyesters characterized by FT-IRand1HNMRspectrosticcopy. Keywords: Aromatic polyester , 4,4Azo Di benzoic acid  , Adipic acid,  dibutyltine dilaurate

The Artin's Exponent of A Special Linear Group SL(2,2k)

The set of all n×n non singular matrices over the field F form a group underthe operation of matrix multiplication, This group is called the general linear groupof dimension n over the field F, denoted by GL(n,F) .The subgroup from this group is called the special linear group denoted by SL(n,F).We take n=2 and F=2k where k natural, k>1. Thus we have SL (2,2k).Our work in this thesis is to find the Artin's exponent from the cyclic subgroups ofthese groups and the character table of it's.Then we have that: a SL(2,2k ) is equal to 2k-1

Surgical Management of Lumbar Spine Fractures and Dislocations

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

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

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

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

Effects of fibres and headed bars on the response of concrete corbels

Six full-scale reinforced concrete corbel specimens were tested to study the influence of steel and polypropylene fibres, headed bars, and horizontal loading on their responses. The experimentally determined capacities were compared with predictions using simplified and refined strut-and-tie models, with the refined models providing better predictions of the capacities.The experimental study demonstrated the beneficial use of fibres in reinforced concrete corbels, that is a reduction in the number and the width of cracks at service loads. Headed bars provided excellent anchorage of the main tension tie reinforcement and eliminated the need to weld bearing plates to the reinforcement, as traditionally done in practice. Refined strut-and-tie models provide better predications to the ultimate load capacities.The improved crack control, using fibre reinforced concrete, and the excellent end anchorage provided by the headed bars provides more durable corbels, suitable for use in parking garage structures

Knowledge, Attitude and Practices regarding Contraceptive Pill and Its Side Effects among Women in Jazan Region, Saudi Arabia

Contraception is one of the common methods of family planning. The oral contraceptive pill (OCP) is among the most effective methods of contraception. This study aimed to assess the knowledge, attitude, and practice of oral contraception use and its side effects among women in the Jazan region, Saudi Arabia. A cross-sectional study was carried out among adult women 18 years and older in the Jazan region. A pre-tested questionnaire was used to assess their demographic characteristics, knowledge, attitudes, previous experience, and pattern of OCP usage. Descriptive analysis and a logistic regression model were used to analyse data. About 570 questionnaires were distributed and achieved a 98.3% response rate. The majority of women participants were between 18 and 25 years old, and 51.4% of the respondents reported that they had previously used or were using OCP. We found that women had good knowledge and a positive attitude towards OCP, with more than half of the users preferring them over other contraceptive methods. This study indicates that attitude, knowledge, and prior experience of OCP have no significant effect on the usage pattern of OCP among women with relatively high socioeconomic status in the Jazan region, Saudi Arabia

SPIN: A Blockchain-Based Framework for Sharing COVID-19 Pandemic Information across Nations

The COVID-19 pandemic has caused many countries around the globe to put strict policies and measures in place in an attempt to control the rapid spread of the virus. These measures have affected economic activities and have impacted a broad range of businesses, such as international traveling, restaurants, and shopping malls. As COVID-19 vaccination efforts progress, countries are starting to relax international travel constraints and permit passengers from certain destinations to cross the border. Moreover, travelers from those destinations are likely required to provide certificates of vaccination results or negative COVID-19 tests before crossing the borders. Implementing these travel guidelines requires sharing information between countries, such as the number of COVID-19 cases and vaccination certificates for travelers. In this paper, we introduce SPIN, a framework leveraging a permissioned blockchain for sharing COVID-19 information between countries. This includes public data, such as the number of vaccinated people, and private data, such as vaccination certificates for individuals. Additionally, we employ cancelable fingerprint templates to authenticate private information about travelers. We analyze the framework from scalability, efficiency, security, and privacy perspectives. To validate our framework, we provide a prototype implementation using the Hyperledger Fabric platform

Outcome of childhood lupus nephritis in Saudi children

Our aim in this study is to report the long-term renal outcome of a cohort of Saudi children with systemic lupus erythematosus (SLE). All patients with childhood lupus nephritis (cLN) proved by renal biopsy seen between January 2000 and June 2015 were reviewed. The renal outcome was assessed according to serum creatinine level, protein/creatinine ratio at the last follow-up visit, and/or evidence of renal impairment during follow-up period and end-stage renal disease (ESRD). Additional outcome measures include accrual damage measured by pediatric adaptation of the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (pSDI), and death related to SLE was determined. A total of 84 (72 females) cLN patients with follow-up duration of 9.3 years (±5.2) were included in this study. The mean current age was 19.4 years (±5.5) and mean age at onset was 9.2 years (±2.4). The most frequent histopathological class was proliferative glomerulonephritis (64.3%) followed by membranous nephritis (27.4%). The mean activity and chronicity indices were 5.9 (±3.9) and 2.9 (±2.2), respectively. Renal microthrombosis was found in 9 (10.7%) patients. All patients treated with immunosuppressive medications; cyclophosphamide used in 64 followed by mycophenolate mofetil in 42, then azathioprine in 19 patients, while rituximab used in 24 patients. At the last follow-up visit, the mean serum creatinine was 147 umol/L (±197) and the mean protein/ creatinine ratio was 0.8 (± 1.1) while the mean total pSDI was 1.9 (±1.9) and mean renal SDI was 0.7 (±1.1). Sixteen (19%) patients had ESRD and eight of them had class IV nephritis. However, there was no significant difference in ESRD by histological class. The overall survival rates were five years: 94% and 10 years: 87%. Infection was the leading cause of mortality. Our patients had severe cLN and required intensive treatment. Despite the survival rate is comparable to other studies, ESRD is more frequent and this may be attributed to genetic or ethnic factors

Joint beamforming and combining design for mmWave integrated access and backhaul networks

Integrated access and backhaul (IAB) networks operating in full-duplex (FD) mode at millimeter wave frequencies have been actively investigated in the context of future-generation communications networks. However, conventional analog cancellation techniques cannot adequately mitigate the self-interference resulting from the FD operation and the multi-user interference. Hence, in this paper, we consider a multi-cell, multi-user IAB network and jointly design the beamforming and combining matrices to maximize the networks weighted sum rate. Given the non-convex nature of the problem, we reformulate it using weighted minimum-mean-square-error (WMMSE) and extended fractional programming (FP) techniques followed by a block coordinate descent (BCD) approach. Extensive simulation results validate the superior performance of our proposed algorithms. Specifically, the WMMSE and FP methods can achieve 50 bits/sec/Hz higher than the benchmark scheme for a network employing three cells with two uplink and two downlink users per cell