Mechanical Parameters Effects on Acoustic Absorption at Polymer Foam

Polymer foams have acoustic absorption properties that play an important role in reducing noise level. When the skeleton is set to motion, it is necessary to use generalized Biot-Allard model which takes into account the deformation of the skeleton and the fluid and the interactions between them. The aim of this work is to study the quality of acoustic absorption in polyurethane foam and to show the importance of the structural vibration of this foam on the absorption by varying mechanical parameters (Young’s modulus E, Poisson’s coefficient ν, structural damping factor η, and the density ρ1). We calculated the absorption coefficient analytically using classical Biot formulation (us, uf) and numerically using Biot mixed formulation (us, p) in 3D COMSOL Multiphysics. The obtained results are compared together and show an excellent agreement. Afterwards, we studied the effect of varying each mechanical parameter independently on the absorption in interval of ±20%. The simulations show that these parameters have an influence on the sound absorption around the resonance frequency fr

Epidemiology of biliary duct cancers

Les cancers des voies biliaires sont rares et représentent 3 % des cancers digestifs. Leur progression est insidieuse, aboutissant souvent à un diagnostic tardif et à un pronostic sombre. L’incidence augmente dans les pays occidentaux au cours des trois dernières décennies. Les cholangiocarcinomes intra (60 %) et extra-hépatiques (25 %) sont à distinguer des cancers de la vésicule biliaire (15 %) dont la preuve histologique est souvent présente, la prédominance plutôt féminine et la répartition géographique différente. Les facteurs de risque sont assez similaires et agissent par l’intermédiaire de l’inflammation des tissus biliaires. Le traitement curatif est la chirurgie, et seule la chimiothérapie palliative des cholangiocarcinomes a fait, récemment, la preuve de sa modeste efficacité.Biliary tract cancers are rare and represent 3% of all digestive tract cancers. These tumors progress insidiously and involve a poor prognosis. Their incidence is increasing in Western countries during the last three decades. Cholangiocarcinoma can affect either the intrahepatic (60%) or extrahepatic (25%) biliary ducts and should be separated from gallbladder carcinoma. This latest is most common in women, gives frequently its histological proof and has different geographic localization. The risk factors induce cancer through inflammatory reaction on the biliary epithelium.Resection is the curative treatment and only palliative chemotherapy is proved efficient in cholangiocarcinoma

0455 : Relationship of hyperglycemia to the no-reflow phenomenon in ST-elevation myocardial infarction patients treated by primary percutaneous coronary intervention

BackgroundIt has been shown that elevated blood glucose levels on admission are associated with worse outcome in ST elevation myocardial infarction.Impaired microvascular function and no-reflow phenomenon seem to be one of the underlying mechanisms of hyperglycemia deleterious effectsAimTo establish the relationship between hyperglycemia on admission and the no-reflow phenomenonMethodsPatients presenting with acute STEMI who underwent primary percutaneous coronary intervention (PCI) were enrolled. ST segment resolution was evaluated at 90 minutes in the worst lead. No-reflow was defined as a resolution of ST segment less than 50% in the worst lead at 90 minutesResults102 consecutive patients were enrolled (87 men and 15 women) with a mean age of 56.95±12.89 years. The no-reflow phenomenon was observed in 28 (27.45%) patients, their glucose level on hospital admission was significantly higher than in patients whithout no-reflow phenomenon (12.48±7.48 vs. 8.55±2.27 mmol/l; p = 0.01). Multivariate analysis showed that hyperglycemia defined as glycemia >11mmol/L was an independent predictor factor for no-reflow (OR = 2.18, CI = 1.42 – 3.84; p = 0.002)ConclusionHyperglycemia on admission is associated with higher risk of no-reflow in STEMI patients undergoing primary PCI

Catalytic removal of Alizarin Red using chromium manganese oxide nanorods: degradation and kinetic studies

Dye removal through photocatalytic degradation employing nanomaterials as catalysts is a growing research area. In current studies, photocatalytic alizarin red (AR) dye degradation has been investigated by designing a series of Cr based manganese oxide nanomaterials (MH1–MH5). Synthesized nanomaterials were characterized by powder X-ray diffraction, scanning electron microscopy/energy dispersive x-ray, Brunauer–Emmett–Teller, and photoluminescence techniques and were utilized for photocatalytic AR dye degradation under UV light. AR dye degradation was monitored by UV–visible spectroscopy and percent degradation was studied for the effect of time, catalyst dose, different dye concentrations, and different pH values of dye solution. All the catalysts have shown more than 80% dye degradation exhibiting good catalytic efficiencies for dye removal. The catalytic pathway was analyzed by applying the kinetic model. A pseudo second-order model was found the best fitted kinetic model indicating a chemically-rate controlled mechanism. Values of constant R2 for all the factors studied were close to unity depicting a good correlation between experimental data

Dynamics of Mycobacterium tuberculosis Lineages in Oman, 2009 to 2018

Study aim. Effective Tuberculosis (TB) control measures in Oman have reduced the annual incidence of tuberculosis cases by 92% between 1981 and 2016. However, the current incidence remains above the program control target of <1 TB case per 100,000 population. This has been partly attributed to a high influx of migrants from countries with high TB burdens. The present study aimed to elucidate Mycobacterium tuberculosis infection dynamics among nationals and foreigners over a period of 10 years. Methods. The study examined TB cases reported between 2009 and 2018 and examined the spatial heterogeneity of TB cases and the distribution of M. tuberculosis genotypes defined by spoligotypes and MIRU-VNTR among Omanis and foreigners. Results. A total of 484 spoligoprofiles were detected among the examined isolates (n = 1295). These include 943 (72.8%) clustered and 352 (27.2%) unique isolates. Diverse M. tuberculosis lineages exist in all provinces in Oman, with most lineages shared between Omanis and foreigners. The most frequent spoligotypes were found to belong to EAI (318, 30.9%), CAS (310, 30.1%), T (154, 14.9%), and Beijing (88, 8.5%) lineages. However, the frequencies of these lineages differed between Omanis and foreigners. Of the clustered strains, 192 MTB isolates were further analysed via MIRU-VNTR. Each isolate exhibited a unique MIRU-VNTR profile, indicative of absence of ongoing transmission. Conclusions. TB incidence exhibits spatial heterogeneity across Oman, with high levels of diversity of M. tuberculosis lineages among Omanis and foreigners and sub-lineages shared between the two groups. However, MIRU-VNTR analysis ruled out ongoing transmission

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

chaotic leadership style as a predictor Of teachers organizational commitment : A field study on some primary schools in the city of M'sila

هدفت الدراسة إلى معرفة مدى إمكانية التنبؤ بالالتزام التنظيمي لدى معلمي المرحلة الابتدائية بمدينة المسيلة بناءاً على درجاتهم في النمط القيادي الفوضوي. &nbsp;تكونت عينة الدراسة من(414) معلماً ومعلمة، تم اختيارهم بطريقة عشوائية بسيطة من معلمي المدارس الابتدائية بمدينة المسيلة للموسم الدراسي 2017/2018. وتوصلت دراستنا إلى وجود علاقة سالبة بين النمط القيادي الفوضوي والالتزام التنظيمي، أي علاقة عكسية وضعيفة، بوجود تأثير دال إحصائياً بين النمط القيادي الفوضوي والالتزام التنظيمي، بنسبة تأثير قدرت بـ2.7%.The study aimed to determine the predictability of the organizational commitment of primary school teachers in M'sila city based on their grades in the chaotic leadership style.The sample consisted of (414) females and males teachers randomly selected from primary schools in M'sila for the academic year 2017/2018.The study results indicated a presence of negative relationship between the chaotic leadership style and the organizational commitment. However, there is a statistically significant impact between chaotic leadership style and organizational commitment with an estimated impact of 2.7%