90 research outputs found
An open-source software framework for the integrated simulation of structures in fire
The traditional methods to understand the development of elevated temperature in a structure, and also the associated structural response, are not representative of realistic fire scenarios. To provide a more accurate and realistic reflection of the fire development, the current paper develops a generic middleware which interfaces between the computational fluid dynamics (CFD) software Fire Dynamics Simulator (FDS) and the finite element (FE) analysis software OpenSees. This framework enables a fully integrated simulation of a realistic fire scenario including the heat transfer through the structure and the resulting thermo-mechanical response. The proposed framework is open-source and freely available and therefore can be used and further developed by researchers and practicing engineers and customised to their requirements. This paper shows validation against two sets of experimental results and one real fire incident. A number of different types of thermal boundary conditions such as gas temperatures and heat fluxes, are obtained from the CFD analysis and are then used in the subsequent heat transfer and thermo-mechanical analysis. The primary advantage of this computational tool is that it provides consultants and designers with the means to undertake large-scale projects requiring performance-based fire engineering solutions
The Role of Socioeconomic Status, Race, and Gender in Patient-Reported Outcomes Following Total Hip Arthroplasty
Background
Disparities in total joint arthroplasty are well-documented. However, much of the research regarding disparities in vulnerable populations receiving total hip arthroplasty (THA) have focused on short-term outcomes. The purpose of this study was to examine the effects of race, gender, and socioeconomic status (SES) on patient-reported outcomes six months following THA.
Methods
Electronic health record data were retrospectively analyzed for 269 individuals who underwent THA at a large urban hospital from 2013-16. Data retrieved included patient demographics, baseline health information, data regarding hospital length of stay when undergoing THA, post-operative complications, and patient-reported function, measured by the Harris Hip Score (HHS) at baseline (pre-operative) and six months post-operatively.
Results
Compared to White patients and male patients, non-White (p = .01) and female (p = .02) patients were lower-functioning prior to surgery. At six months post-operatively, White patients had significantly better function than non-White patients, (p = .05) and patients of higher SES had significantly better function than patients of lower SES (p = .05). Regression analyses revealed that, after controlling for race, gender, and SES, the only significant predictor of six-month improvement in HHS was the pre-operative HHS score (p \u3c .001).
Conclusion
These results indicate that female, non-White, and lower SES patients undergoing THA may have lower function pre-operatively and may not experience as much improvement in physical function post-operatively as their male, White, and higher SES counterparts.
Further research is needed to determine if race, gender, and socioeconomic differences in pre-operative function lead to long-term disparities in function following THA, using larger sample sizes and outcomes beyond 6 months post-operatively
Parameters to Assess Nutritional Status in a Moroccan Hemodialysis Cohort
Introduction: Malnutrition is common in maintenance hemodialysis (HD) and is associated with increased mortality and morbidity in affected patients. The aim of this study was to determine the prevalence of malnutrition and correlate the methods of nutritional assessment.Methods: We evaluated the nutritional status of 40 prevalent HD patients by subjective global assessment (SGA) score, anthropometrics [body mass index (BMI), arm circumference (AC), triceps skin-fold thicknesses (TSF), arm muscle circumference (AMC)], biochemical tests [normalized protein equivalent to total nitrogen appearance (nPNA), and pre-dialysis serum albumin and serum prealbumin levels] and bio-electrical impedance (BEI) analysis to estimate body composition [lean tissue index (LTI) and fat tissue index (FTI)].Results: The study assessed 40 patients (20 males and 20 females) with a mean age of 50.7±16.5 years. The prevalence of malnutrition according to the different methods ranged from 5 % to 65%. There were highly significant gender-specific differences in AMC (p < 0.001) and TSF (p < 0.001). The BEI revealed a highly significant difference in LTI (p < 0.001) but no difference in FTI (p = 0.14) according to gender. There was a positive correlation between LTI and both serum albumin (r = 0.37; p = 0.018) and serum prealbumin (r = 0.53; p < 0.001). Also, there was a significant positive correlation between FTI and BMI (r = 0.59; p < 0.001), AC (r = 0.44; p = 0.004) and TSF (r = 0.61; p < 0.001).Conclusion: Our data suggest that BEI analysis provides a useful means of assessing nutritional status and was correlated with anthropometrics and biochemical findings.Keywords: Anthropometric Measurements; Bioelectrical Impedance; Hemodialysis; Malnutrition; Subjective Global Assessmen
Molecular Characterization of Mercury Resistant Bacteria Isolated from Tannery Wastewater
Mercury resistant (HgR) bacteria were isolated from heavy metal polluted wastewater and soil, collected from the proximity of some tanneries from Kasur, Pakistan. Three out of 30 bacterial strains were screened out on the basis of resistance level against various concentrations of HgCl2. Bacterial isolates AZ-1, AZ-2 and AZ-3 showed resistance up to 40 μg/mL of HgCl2 and mercury sensitive (HgS) isolate ZA-15 was taken as a negative control. 16S rDNA ribotyping and phylogenetic analysis were performed for the characterization of isolates as Bacillus sp. AZ-1 (KT270477), B. cereus AZ-2 (KT270478), B. cereus AZ-3 (KT270479) and Enterobacter cloacae ZA-15 (KJ728671). Phylogenetic relationship on the basis of merA nucleotide sequence confirmed 51-100% homology with the corresponding region of the merA gene of already reported mercury resistant Gram-positive bacteria. Restriction fragment length polymorphism (RFLP) analysis was applied to the amplification products of 16S rRNA and merA genes and a specific restriction patterns was successfully obtained after treatment with different endonucleases. A small-scale reservoir of Luria Bertani (LB) medium supplemented with 30 μg/mL of HgCl2 was designed to check the detoxification ability of the selected strains. The results demonstrated 83% detoxification of mercury by both B. cereus AZ-2 and B. cereus AZ-3, and 76% detoxification by Bacillus sp. AZ-1 (p<0.05)
Technoeconomic Modeling of Plant-Based Griffithsin Manufacturing
Griffithsin is a marine algal lectin that exhibits broad-spectrum antiviral activity by binding oligomannose glycans on viral envelope glycoproteins, including those found in HIV-1, HSV-2, SARS, HCV and other enveloped viruses. An efficient, scalable and cost-effective manufacturing process for Griffithsin is essential for the adoption of this drug in human antiviral prophylaxis and therapy, particularly in cost-sensitive indications such as topical microbicides for HIV-1 prevention. The production of certain classes of recombinant biologics in plants can offer scalability, cost and environmental impact advantages over traditional biomanufacturing platforms. Previously, we showed the technical viability of producing recombinant Griffithsin in plants. In this study, we conducted a technoeconomic analysis (TEA) of plant-produced Griffithsin manufactured at commercial launch volumes for use in HIV microbicides. Data derived from multiple non-sequential manufacturing batches conducted at pilot scale and existing facility designs were used to build a technoeconomic model using SuperPro Designer® modeling software. With an assumed commercial launch volume of 20 kg Griffithsin/year for 6.7 million doses of Griffithsin microbicide at 3 mg/dose, a transient vector expression yield of 0.52 g Griffithsin/kg leaf biomass, recovery efficiency of 70%, and purity of >99%, we calculated a manufacturing cost for the drug substance of 0.38/dose assuming a 20% net fee for a contract manufacturing organization (CMO). This is the first report modeling the manufacturing economics of Griffithsin. The process analyzed is readily scalable and subject to efficiency improvements and could provide the needed market volumes of the lectin within an acceptable range of costs, even for cost-constrained products such as microbicides. The manufacturing process was also assessed for environmental, health and safety impact and found to have a highly favorable environmental output index with negligible risks to health and safety. The results of this study help validate the plant-based manufacturing platform and should assist in selecting preferred indications for Griffithsin as a novel drug
Costs and Consequences: Hepatitis C Seroprevalence in the Military and Its Impact on Potential Screening Strategies
UNLABELLED: Knowledge of the contemporary epidemiology of hepatitis C viral (HCV) infection among military personnel can inform potential Department of Defense screening policy. HCV infection status at the time of accession and following deployment was determined by evaluating reposed serum from 10,000 service members recently deployed to combat operations in Iraq and Afghanistan in the period 2007-2010. A cost model was developed from the perspective of the Department of Defense for a military applicant screening program. Return on investment was based on comparison between screening program costs and potential treatment costs avoided. The prevalence of HCV antibody-positive and chronic HCV infection at accession among younger recently deployed military personnel born after 1965 was 0.98/1000 (95% confidence interval 0.45-1.85) and 0.43/1000 (95% confidence interval 0.12-1.11), respectively. Among these, service-related incidence was low; 64% of infections were present at the time of accession. With no screening, the cost to the Department of Defense of treating the estimated 93 cases of chronic HCV cases from a single year\u27s accession cohort was 3.1 million dollar advantage over not screening.
CONCLUSIONS: Applicant screening will reduce chronic HCV infection in the force, result in a small system costs savings, and decrease the threat of transfusion-transmitted HCV infection in the battlefield blood supply and may lead to earlier diagnosis and linkage to care; initiation of an applicant screening program will require ongoing evaluation that considers changes in the treatment cost and practice landscape, screening options, and the epidemiology of HCV in the applicant/accession and overall force populations
Hepatitis B Seroprevalence in the U.S. Military and its Impact on Potential Screening Strategies
INTRODUCTION: Knowledge of the contemporary epidemiology of hepatitis B virus (HBV) infection among military personnel can inform potential Department of Defense (DoD) screening policy and infection and disease control strategies.
MATERIALS AND METHODS: HBV infection status at accession and following deployment was determined by evaluating reposed serum from 10,000 service members recently deployed to combat operations in Iraq and Afghanistan in the period from 2007 to 2010. A cost model was developed from the perspective of the Department of Defense for a program to integrate HBV infection screening of applicants for military service into the existing screening program of screening new accessions for vaccine-preventable infections.
RESULTS: The prevalence of chronic HBV infection at accession was 2.3/1,000 (95% CI: 1.4, 3.2); most cases (16/21, 76%) identified after deployment were present at accession. There were 110 military service-related HBV infections identified. Screening accessions who are identified as HBV susceptible with HBV surface antigen followed by HBV surface antigen neutralization for confirmation offered no cost advantage over not screening and resulted in a net annual increase in cost of $5.78 million. However, screening would exclude as many as 514 HBV cases each year from accession.
CONCLUSIONS: Screening for HBV infection at service entry would potentially reduce chronic HBV infection in the force, decrease the threat of transfusion-transmitted HBV infection in the battlefield blood supply, and lead to earlier diagnosis and linkage to care; however, applicant screening is not cost saving. Service-related incident infections indicate a durable threat, the need for improved laboratory-based surveillance tools, and mandate review of immunization policy and practice
Common genetic variation and susceptibility to partial epilepsies: a genome-wide association study
Partial epilepsies have a substantial heritability. However, the actual genetic causes are largely unknown. In contrast to many other common diseases for which genetic association-studies have successfully revealed common variants associated with disease risk, the role of common variation in partial epilepsies has not yet been explored in a well-powered study. We undertook a genome-wide association-study to identify common variants which influence risk for epilepsy shared amongst partial epilepsy syndromes, in 3445 patients and 6935 controls of European ancestry. We did not identify any genome-wide significant association. A few single nucleotide polymorphisms may warrant further investigation. We exclude common genetic variants with effect sizes above a modest 1.3 odds ratio for a single variant as contributors to genetic susceptibility shared across the partial epilepsies. We show that, at best, common genetic variation can only have a modest role in predisposition to the partial epilepsies when considered across syndromes in Europeans. The genetic architecture of the partial epilepsies is likely to be very complex, reflecting genotypic and phenotypic heterogeneity. Larger meta-analyses are required to identify variants of smaller effect sizes (odds ratio <1.3) or syndrome-specific variants. Further, our results suggest research efforts should also be directed towards identifying the multiple rare variants likely to account for at least part of the heritability of the partial epilepsies. Data emerging from genome-wide association-studies will be valuable during the next serious challenge of interpreting all the genetic variation emerging from whole-genome sequencing studie
Common genetic variation and susceptibility to partial epilepsies: a genome-wide association study
Partial epilepsies have a substantial heritability. However, the actual genetic causes are largely unknown. In contrast to many other common diseases for which genetic association-studies have successfully revealed common variants associated with disease risk, the role of common variation in partial epilepsies has not yet been explored in a well-powered study. We undertook a genome-wide association-study to identify common variants which influence risk for epilepsy shared amongst partial epilepsy syndromes, in 3445 patients and 6935 controls of European ancestry. We did not identify any genome-wide significant association. A few single nucleotide polymorphisms may warrant further investigation. We exclude common genetic variants with effect sizes above a modest 1.3 odds ratio for a single variant as contributors to genetic susceptibility shared across the partial epilepsies. We show that, at best, common genetic variation can only have a modest role in predisposition to the partial epilepsies when considered across syndromes in Europeans. The genetic architecture of the partial epilepsies is likely to be very complex, reflecting genotypic and phenotypic heterogeneity. Larger meta-analyses are required to identify variants of smaller effect sizes (odds ratio <1.3) or syndrome-specific variants. Further, our results suggest research efforts should also be directed towards identifying the multiple rare variants likely to account for at least part of the heritability of the partial epilepsies. Data emerging from genome-wide association-studies will be valuable during the next serious challenge of interpreting all the genetic variation emerging from whole-genome sequencing studies
Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey
Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020
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