Predicting Shunt Currents in Stacks of Bipolar Plate Cells with Conducting Manifolds

A method is presented for predicting shunt currents in stacks of bipolar plate cells with conducting manifolds. The method is based on the requirement that the potential drop through the solution in a manifold be large enough to force current to leave the solution and to enter the conducting manifold. The current that leaves the solution in the manifold enters the conducting manifold at the anode end of the stack and returns to the solution at the cathode end. This could cause catastrophic failure of a manifold

From Transplant to Tablets : A paradigm shift in Oncology

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Acute myeloid leukemia in children in Pakistan: an audit

Objective: To see the clinical features and treatment of children with Acute Myeloid Leukemia (AML) in Pakistan. Setting: Tertiary referral at a specialist Hematology/Oncology center. Methods: Retrospective, chart-based review of children (less than 14 years) admitted to the hospital with a diagnosis of AML between January 1987 and August 1997. Results: A total of 23 patients were admitted. There were 18 males and 5 females. The mean age was 8 5 years. M3 was the commonest morphological subtype (43%). Twenty- two percent of the patients presented with hyperleucocytosis (TLC\u3e 100 x i09 /L) and 95% with an elevated LDH (\u3e548 lUlL). Pneumonia at presentation was seen in 29%. Of 23 patients 14 were evaluable for responses. Six patients died early (43%); 3 before starting the chemotherapy and 3 during the induction chemotherapy, 8/11 (73%) patients entered remission. The median survival was 9 months. Conclusion: The pediatric patients with acute myeloid leukemia present with advanced disease. There is a high early death rate (within 28 days of diagnosis). The long-term outcome was inferior to that reported in the literature (JPMA 52:247; 2002)

Methods for attributing land-use emissions to products

Roughly one-third of anthropogenic GHG emissions are caused by agricultural and forestry activities and land-use change (collectively, land-use emissions'). Understanding the ultimate drivers of these emissions requires attributing emissions to specific land-use activities and products. Although quantities of land-use emissions are matters of fact, the methodological choices and assumptions required to attribute those emissions to activities and products depend on research goals and data availability. In this review, we explore several possible accounting methods. Our results highlight the sensitivity of accounting to temporal distributions of emissions and the consequences of replacing spatially-explicit data with aggregate proxies such as production or harvested area data. Different accounting options emphasize different causes of land-use emissions (e.g., proximate or indirect drivers of deforestation). To support public policies that effectively balance competing objectives, analysts should carefully consider and communicate implications of accounting choices

Experimental validation of a flat punch indentation methodology calibrated against unconfined compression tests for determination of soft tissue biomechanics

AbstractMechanical characterisation of soft biological tissues using standard compression or tensile testing presents a significant challenge due to specimen geometrical irregularities, difficulties in cutting intact and appropriately sized test samples, and issues with slippage or damage at the grips. Indentation can overcome these problems but requires fitting a model to the resulting load–displacement data in order to calculate moduli. Despite the widespread use of this technique, few studies experimentally validate their chosen model or compensate for boundary effects. In this study, viscoelastic hydrogels of different concentrations and dimensions were used to calibrate an indentation technique performed at large specimen-strain deformation (20%) and analysed with a range of routinely used mathematical models. A rigid, flat-ended cylindrical indenter was applied to each specimen from which ‘indentation moduli’ and relaxation properties were calculated and compared against values obtained from unconfined compression. Only one indentation model showed good agreement (<10% difference) with all moduli values obtained from compression. A sample thickness to indenter diameter ratio ≥1:1 and sample diameter to indenter diameter ratio ≥4:1 was necessary to achieve the greatest accuracy. However, it is not always possible to use biological samples within these limits, therefore we developed a series of correction factors. The approach was validated using human diseased omentum and bovine articular cartilage resulting in mechanical properties closely matching compression values. We therefore present a widely useable indentation analysis method to allow more accurate calculation of material mechanics which is important in the study of soft tissue development, ageing, health and disease

What are our Options in the Fight against Breast Cancer?

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Contemporary Prevalence of Byssinosis in Low- and Middle-Income Countries: A Systematic Review

We aimed to identify the contemporary prevalence of byssinosis through a systematic review. Medline, Web of Science, Embase, and Global Health databases were used to identify studies published in any language between 2000 and 2019, reporting primary data on byssinosis among adults. We used the Joanna Briggs Institute checklist to estimate the risk of bias in studies and undertook a qualitative, narrative data analysis. The review considered the prevalence of byssinosis, chest tightness, and airflow obstruction in textile workers in low- and middle-income countries (LMICs). We found 26 relevant studies that included 6930 workers across 12 countries. Most of the studies (n = 19) were from Asia, and seven from African countries. Twenty-five studies were cross-sectional surveys while one was a cohort study. The prevalence of byssinosis was reported by 18 studies, and ranged from 8% to 38%, without any clear associations, at the group level, between the prevalence of byssinosis and durations of workers’ exposures. Prevalence of chest tightness ranged between 4% and 58% and that of airflow obstruction between 10% and 30%. A strong correlation (r = 0.72) was found between prevalence of byssinosis and cotton dust levels. Our findings indicate that byssinosis remains a significant, contemporary problem in some parts of the textile sector in LMICs