Unconditional Positivity-Preserving and Energy Stable Schemes for a Reduced Poisson-Nernst-Planck System

The Poisson-Nernst-Planck (PNP) system is a widely accepted model for simulation of ionic channels. In this paper, we design, analyze, and numerically validate a second order unconditional positivity-preserving scheme for solving a reduced PNP system, which can well approximate the three dimensional ion channel problem. Positivity of numerical solutions is proven to hold true independent of the size of time steps and the choice of the Poisson solver. The scheme is easy to implement without resorting to any iteration method. Several numerical examples further confirm the positivity-preserving property, and demonstrate the accuracy, efficiency, and robustness of the proposed scheme, as well as the fast approach to steady states.     

Electronic clinical records in primary care for estimating disease burden and management. An example of COPD

Chronic obstructive pulmonary disease (COPD) is a significant health problem in developed countries. We aimed to estimate the prevalence of COPD in a single Spanish healthcare area. We also aimed to assess if there are any differences in prevalence and spirometry use among primary care services by utilizing already registered information. We designed a cross-sectional study to determine the prevalence of COPD and the performance of spirometries in each primary care service. A total of 8,444 patients were diagnosed with COPD, with a prevalence of 2.6% for individuals older than 39 years. The prevalence increased with age and was much higher in men. Significant heterogeneity was found in the prevalence of COPD and spirometry use among primary care services. COPD was underdiagnosed and there was wide variability in spirometry use in our area. Greater efforts are needed to diagnose COPD in order to improve its clinical outcomes and to refine registries so that they can be used as reliable sources of information     

Optimizing access and configuration of trauma centre care in New South Wales

IntroductionGetting the right patient, to the right place, at the right time is dependent on a multitude of modifiable and non-modifiable factors. One potentially modifiable factor is the number and location of trauma centres (TC). Overabundance of TC dilutes volumes and could be associated with worse outcomes. We describe a methodology that evaluates trauma system reconfiguration without reductions in potential access to care. We used the mature trauma system of New South Wales (NSW) as a model given the perceived overabundance of urban major trauma centres (MTC).MethodsWe first evaluated potential access to TC care via ground and air transport through the use of geographic information systems (GIS) network analysis. Potential access was defined as the proportion of the population living within 60-min transport time from a potential scene of injury to a TC by ground or rotary-wing aircraft. Sensitivity analyses were carried out in order to account for potential pre-hospital interventions and/or transport delays; travel times of 15-, 30-, 45-, 60-, and 90-min were also analyzed. We then evaluated if the current configuration of the system (number of urban MTS in the Sydney basin) could be optimized without reductions in potential access to care using two GIS methodologies: location-allocation and individual removal of MTC.Results86% of the NSW population has potential access to a TC within 60 min ground travel time; potential access improves to 99% with rotary-wing transport. The 1% of the population without potential TC access lives in 48% of the land area (>384,000km2). Utilizing two different methodologies we identified that there was no change in potential access by ground transport after removing 1 or 2 MTC in the Sydney basin at the 30-, 45-, and 60-min transport times. However, 0.02% and 0.5% of the population would not have potential access to MTC care at 15 min after removing one and two MTC respectively.DiscussionRedistribution of the number of MTC in the Sydney basin could be achieved without a significant impact on potential access to care. Our approach can be utilized as an initial tool to evaluate a trauma system where overabundance of coverage is present.     

Prevalence of and factors contributing to anxiety,depression and cognitive disorders among urban elderly in Odisha – A study through the health systems’ Lens

IntroductionGrowing geriatric mental health needs of urban population in India pose several programmatic challenges. This study aimed to assess anxiety, depression and cognitive disorders among urban elderly, and explore availability of social support mechanisms and of a responsive health system to implement the national mental health programme.Methods244 respondents were randomly selected from Berhampur city. We administered a semi-structured interview schedule to assess substance abuse, chronic morbidity, anxiety, depression and cognitive abilities. Further, in-depth interviews were conducted with 25 key informants including district officials, psychiatrists, and programme managers. We used R software and ‘thematic framework’ approach, respectively, for quantitative and qualitative data analysis. Ethical standards were complied with.ResultsAbout half of the respondents were economically dependent; 57.3% had moderate to severe anxiety; 46.7% had moderate to severe depression; while about 25% had severe cognitive impairments. We found association of chewing tobacco (1.34(0.28–2.40)) and depression (0.52(0.37–0.68)) with anxiety; negative perception about elderly-friendly society (1.64(0.75–2.53)) and physical inactivity (2.88(1.60–4.16)) with depression; and age (-0.11(-0.20 – -0.02)) and physical inactivity (-3.44(-5.13 – -1.74)) with cognitive disorders. Qualitative analysis revealed lack of awareness, social stigma, poor availability of trained human resources, and poor political commitment as important systemic barriers to early detection and treatment of mental ailments among the elderly.ConclusionEstablishing tobacco cessation centres, sensitizing community about mental health needs of elderly, incentivizing physical activity of elderly, integrating mental health with primary care, multi-skilling providers and developing a cadre of community counsellors need urgent attention of policy makers and programme implementers.     

不同浓度氯氮平对小鼠空腹血糖和骨骼肌葡萄糖转运蛋白4基因表达的影响

目的探讨氯氮平对雄性C57BL/6小鼠空腹血糖和骨骼肌葡萄糖转运蛋白4(GLUT4)基因表达的影响。方法将63只雄性C57BL/6小鼠随机分为3组,每组21只,分别灌胃给予蒸馏水、氯氮平4mg/kg及氯氮平20mg/kg,于给药后3h、1周、4周以试纸法测定各组空腹血糖,用逆转录-聚合酶链反应测定GLUT4mRNA表达。结果(1)灌药后3h、1周氯氮平4mg/kg组和氯氮平20mg/kg组空腹血糖和GLUT4mRNA的表达与空白对照组相比,差异无统计学意义(P>0.05);(2)灌药后4周氯氮平4mg/kg组和20mg/kg组的空腹血糖值[(5.6±0.5)mmol/L和(5.8±0.5)mmol/L]高于空白对照组[(4.6±0.6)mmol/L],而GLUT4mRNA的表达(0.50±0.14和0.48±0.12)却低于空白对照组(0.85±0.27),差异均有统计学意义(P<0.01)。结论氯氮平可以慢性升高空腹血糖,降低GLUT4mRNA的表达,可能是抗精神病药长期应用后血糖升高的发生机制之一。