541 research outputs found

    Altering Entry Angles in a Jump Landing Task Modifies Biomechanical Risk Factors of ACL Injury

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    This study investigated the effects of changing the entry-angle of a jump landing movement on ACL injury risk factors. Eight female recreational athletes performed 21 trials of a jump landing task. The direction of the first jump varied from -90° to 90° from the anterior axis in 30-degree increments. As the entry angle increased to the left, peak knee flexion and valgus angles as well as external valgus moments remained the same. In conditions where participants jumped more to their right, knee flexion angles were smaller and knee external valgus moments were greater. It can be concluded that kinematic analyses of frontal plane motion alone may not provide sufficient information for risk assessment on the field, as it may not reflect parallel changes in kinetics. These results can be used to further understand ACL injury risk factors in asymmetric jumping conditions

    Neural tangent kernel analysis of PINN for advection-diffusion equation

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    Physics-informed neural networks (PINNs) numerically approximate the solution of a partial differential equation (PDE) by incorporating the residual of the PDE along with its initial/boundary conditions into the loss function. In spite of their partial success, PINNs are known to struggle even in simple cases where the closed-form analytical solution is available. In order to better understand the learning mechanism of PINNs, this work focuses on a systematic analysis of PINNs for the linear advection-diffusion equation (LAD) using the Neural Tangent Kernel (NTK) theory. Thanks to the NTK analysis, the effects of the advection speed/diffusion parameter on the training dynamics of PINNs are studied and clarified. We show that the training difficulty of PINNs is a result of 1) the so-called spectral bias, which leads to difficulty in learning high-frequency behaviours; and 2) convergence rate disparity between different loss components that results in training failure. The latter occurs even in the cases where the solution of the underlying PDE does not exhibit high-frequency behaviour. Furthermore, we observe that this training difficulty manifests itself, to some extent, differently in advection-dominated and diffusion-dominated regimes. Different strategies to address these issues are also discussed. In particular, it is demonstrated that periodic activation functions can be used to partly resolve the spectral bias issue

    Students’ Perceptions of Online Learning to Inform Jesuit Education

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    A small group of faculty, staff, and administrators, known as the Online Learning Community (OLC) were collectively interested in enriching online learning at a Jesuit university. With a culture at this Jesuit and Mercy university driven by face-to-face (F2F) learning, the first step was to assess students’ perceptions of online learning from students who have taken online courses at the university. The survey, guided by best instructor practices in online learning and Jesuit philosophy, traditions, and concepts, was designed to explore students’ perceptions, experiences, and practices in online learning. Students (N=484) self-enrolled in the study and included students from all the colleges in the university and across four campuses. The most notable response in the data was students’ (72%) desire for more online learning opportunities at the host university. The freedom and flexibility afforded in online classes was prevalent in students open-ended statements about online learning but additionally emphasized the importance of instructor qualities of being organized in course delivery, availability, and effective communication skills. In this study, OLC members sought to place students’ perceptions at the core of efforts to inform online learning at this Jesuit and Mercy university. The findings enrich and demonstrate linkages with core Jesuit traditions and concepts

    EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI): Study protocol for a multicentre, observational trial

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    Introduction More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. Methods and analysis EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. Ethics and dissemination EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369

    Factors affecting hospital length of stay and hospital charges associated with road traffic-related injuries in Iran

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    Road traffic injuries (RTIs) are a substantial cause of mortality and disability globally. There is little published information regarding healthcare resource utilization following RTIs, especially in low and middle-income countries (LMICs). The aim of this study was to assess total hospital charges and length of stay (LOS) associated with RTIs in Iran and to explore the association with patients' socio-demographic characteristics, insurance status and injury-related factors (e.g. type of road users and safety equipment)

    A Prospective Study on Risk Factors for Acute Kidney Injury and All-Cause Mortality in Hospitalized COVID-19 Patients From Tehran (Iran)

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    Background: Several reports suggested that acute kidney injury (AKI) is a relatively common occurrence in hospitalized COVID-19 patients, but its prevalence is inconsistently reported across different populations. Moreover, it is unknown whether AKI results from a direct infection of the kidney by SARS-CoV-2 or it is a consequence of the physiologic disturbances and therapies used to treat COVID-19. We aimed to estimate the prevalence of AKI since it varies by geographical settings, time periods, and populations studied and to investigate whether clinical information and laboratory findings collected at hospital admission might influence AKI incidence (and mortality) in a particular point in time during hospitalization for COVID-19. Methods: Herein we conducted a prospective longitudinal study investigating the prevalence of AKI and associated factors in 997 COVID-19 patients admitted to the Baqiyatallah general hospital of Tehran (Iran), collecting both clinical information and several dates (of: birth; hospital admission; AKI onset; ICU admission; hospital discharge; death). In order to examine how the clinical factors influenced AKI incidence and all-cause mortality during hospitalization, survival analysis using the Cox proportional-hazard models was adopted. Two separate multiple Cox regression models were fitted for each outcome (AKI and death). Results: In this group of hospitalized COVID-19 patients, the prevalence of AKI was 28.5% and the mortality rate was 19.3%. AKI incidence was significantly enhanced by diabetes, hyperkalemia, higher levels of WBC count, and blood urea nitrogen (BUN). COVID-19 patients more likely to die over the course of their hospitalization were those presenting a joint association between ICU admission with either severe COVID-19 or even mild/moderate COVID-19, hypokalemia, and higher levels of BUN, WBC, and LDH measured at hospital admission. Diabetes and comorbidities did not increase the mortality risk among these hospitalized COVID-19 patients. Conclusions: Since the majority of patients developed AKI after ICU referral and 40% of them were admitted to ICU within 2 days since hospital admission, these patients may have been already in critical clinical conditions at admission, despite being affected by a mild/moderate form of COVID-19, suggesting the need of early monitoring of these patients for the onset of eventual systemic complications

    Experimental and Theoretical Study of Phase Equilibria in Aqueous Mixtures of Lactic Acid with Benzyl Alcohol and p-Xylene at Various Temperatures

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    Liquid-liquid equilibria for the (water + lactic acid + benzyl alcohol or p-xylene) ternary systems were investigated at atmospheric pressure and in the temperature range from 298.15-318.15 K. The studied systems exhibit two types of liquid-liquid equilibrium (LLE) behavior. The system consisting of benzyl alcohol displays type-1 LLE behavior, while a type-2 behavior is exhibited by the other system. The quality of the experimental tie line data was determined using the Othmer-Tobias and Hand equations. Distribution coefficients and separation factors were calculated over the biphasic region. The experimental tie line data were regressed using the UNIQUAC and NRTL models and the binary interaction parameters were obtained

    Early manifestation of ARDS in COVID-19 infection in a 51- year-old man affected by Mounier-Kuhn syndrome

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    A 51-year-old man known to be affected by Mounier-Kuhn syndrome (MKS). presented to Accident & Emergecy (A&E) with fever, dyspnea and deterioration of his chronic coughs. Increased diameters of his trachea (39 mm), right (30 mm) and left (26 mm) main bronchi were revealed by chest computerized tomography (CT) scan. CT scan showed also ground-glass opacities (GGO) and bronchiectasis in the mid and lower zones of both lungs. COIVD-19 infection was eventually confirmed by RT-PCR. A severe form of COVID-19 could occur even in the early stages of the disease in presence of underlying co-morbidities including MKS, which increases the susceptibility to more recurrent and severe respiratory infections. © 2020 Elsevier Inc

    Molecular detection of prostate specific antigen in patients with prostate cancer or benign prostate hyperplasia the first investigation from Iran

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    Prostate cancer is the second common form of cancer in men. Detection of circulating Prostate Specific Antigen (PSA) transcripts has effectively been used for early diagnosis of prostate cancer cells. This investigation employed a reverse transcriptase polymerase chain reaction (RT-PCR) technique to distinguish the patients with either localized or metastatic prostate cancer (CaP) vs. Benign Prostate Hyperplasia (BPH) and control subjects, as compared with clinical and pathological records. With reservation of ethical issues, blood samples were collected from 60 cases. Based on pathological and clinical findings, 25 patients (20 with localized cancer, 5 with metastatic), 22 with BPH, and 13 healthy (including 3 females) subjects as negative controls, were selected from Shariati, Mehrad, Sina,, Khatam and Atie Hospitals in Tehran, Iran. RT-PCR for a 260 bp PSA transcript was then performed. Clinical and pathological records were used for the assessment and comparison of PSA RT-PCR results. None of the control subjects and BPH (with 7 exceptions) were found positive by RT-PCR (Relative specificity= 72.7). In patients with prostate cancer, 21 out of 25 were found PSA positive (Relative sensitivity= 83.4) and the remaining 3 have been shown to be PSA negative (Positive predictive value= 83.4). All of 5 metastatic patients (100) revealed PSA positive results. Our data reflects the clinical relevance and significance of RT-PCR results as assessed with clinical and pathological examinations. PSA RT-PCR might be used as a powerful means for diagnosis, even when either pathological or clinical findings are negative, and could be employed for further molecular epidemiology surveys

    Effectiveness and safety of non-steroidal anti-inflammatory drugs and opioid treatment for knee and hip osteoarthritis: network meta-analysis

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    OBJECTIVE: To assess the effectiveness and safety of different preparations and doses of non-steroidal anti-inflammatory drugs (NSAIDs), opioids, and paracetamol for knee and hip osteoarthritis pain and physical function to enable effective and safe use of these drugs at their lowest possible dose. DESIGN: Systematic review and network meta-analysis of randomised trials. DATA SOURCES: Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, regulatory agency websites, and ClinicalTrials.gov from inception to 28 June 2021. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Randomised trials published in English with ≥100 patients per group that evaluated NSAIDs, opioids, or paracetamol (acetaminophen) to treat osteoarthritis. OUTCOMES AND MEASURES: The prespecified primary outcome was pain. Physical function and safety outcomes were also assessed. REVIEW METHODS: Two reviewers independently extracted outcomes data and evaluated the risk of bias of included trials. Bayesian random effects models were used for network meta-analysis of all analyses. Effect estimates are comparisons between active treatments and oral placebo. RESULTS: 192 trials comprising 102 829 participants examined 90 different active preparations or doses (68 for NSAIDs, 19 for opioids, and three for paracetamol). Five oral preparations (diclofenac 150 mg/day, etoricoxib 60 and 90 mg/day, and rofecoxib 25 and 50 mg/day) had ≥99% probability of more pronounced treatment effects than the minimal clinically relevant reduction in pain. Topical diclofenac (70-81 and 140-160 mg/day) had ≥92.3% probability, and all opioids had ≤53% probability of more pronounced treatment effects than the minimal clinically relevant reduction in pain. 18.5%, 0%, and 83.3% of the oral NSAIDs, topical NSAIDs, and opioids, respectively, had an increased risk of dropouts due to adverse events. 29.8%, 0%, and 89.5% of oral NSAIDs, topical NSAIDs, and opioids, respectively, had an increased risk of any adverse event. Oxymorphone 80 mg/day had the highest risk of dropouts due to adverse events (51%) and any adverse event (88%). CONCLUSIONS: Etoricoxib 60 mg/day and diclofenac 150 mg/day seem to be the most effective oral NSAIDs for pain and function in patients with osteoarthritis. However, these treatments are probably not appropriate for patients with comorbidities or for long term use because of the slight increase in the risk of adverse events. Additionally, an increased risk of dropping out due to adverse events was found for diclofenac 150 mg/day. Topical diclofenac 70-81 mg/day seems to be effective and generally safer because of reduced systemic exposure and lower dose, and should be considered as first line pharmacological treatment for knee osteoarthritis. The clinical benefit of opioid treatment, regardless of preparation or dose, does not outweigh the harm it might cause in patients with osteoarthritis. SYSTEMATIC REVIEW REGISTRATION: PROSPERO number CRD42020213656
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