Thermally Excited Resonating Membrane Mass Flow Sensor

A mass flow sensor based on the frequency shift of a resonating microstructure is being developed, using a measurement principle of the thermoanemometry type. The sensor is to be applied for mass flows up to 10 standard cubic centimeters per minute (sccm; 10sccm = 0.17 mg s-1), with a high sensitivity, a high resolution and a fast response. Here we report on the first prototype consisting of a 2 μm thick membrane: the temperature elevation of the thermally excited vibrating membrane affects its resonance frequency. The three-dimemsional heat transfer within the membrane and the mass flow is modeled, and expressions are derived for the resonance frequencies of initially curved and stressed membranes. Experiments have been carried out for nitrogen flows of up to 500 sccm passing over thermally excited membranes. Predicted and measured values for the shift of the resonance frequency agree well. The sensitivity of the average temperature elevation to the mass flow is quite small: at 10 sccm the cooling effect of the mass flow is only 0.2% of the heat loss by conduction to the substrate. At a resonance frequency of 5.0 kHz, and an average temperature elevation of the mebrane of 8°C, this still leads to a frequency change of 13 Hz in the mass flow range from zero to 10 sccm. Suggestions are presented for increasing the sensitivity of the sensor

A house is not a home: a network model perspective on the dynamics between subjective quality of living conditions, social support, and mental health of refugees and asylum seekers

Background: Providing adequate living conditions for forcibly displaced people represents a significant challenge for host countries such as Germany. This study explores refugee mental health’s reciprocal, dynamic relationship with post-migration living conditions and social support. Methods: The study sample included 325 Arabic- or Farsi-speaking asylum seekers and refugees residing in Germany since 2014 and seeking mental health treatment. Associations between reported symptoms of post-traumatic stress and depression and the subjective quality of living conditions and perceived social support were analyzed using a two-level approach including multiple linear regression and network analyses. Results: Post-migration quality of living conditions and perceived social support were significantly associated with negative mental health outcomes on both levels. In the network, both post-migration factors were negatively connected with overlapping symptoms of psychiatric disorders, representing potential target symptoms for psychological treatment. Conclusion: Post-migration quality of living conditions and social support are important factors for refugee mental health and should be targeted by various actors fostering mental well-being and integration

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

Background: The EMPA KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population. Methods: EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110. Findings: Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5–2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62–0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16–1·59), representing a 50% (42–58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1). Interpretation: In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease. Funding: Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council

Some geomorphic models of flood hazards on distributary flow areas in southern Arizona

The Federal Emergency Management Agency (FEMA) uses a method for evaluating flood hazards on alluvial fans that assumes an equal chance of flooding along a radial arc across the fan surface. In southern Arizona there are distributary flow areas (alluvial fans) that do not conform with FEMA's assumption. Thirty-nine sample sites were chosen from the Basin and Range physiographic province in southern Arizona. These sites were classified into five categories of flood hazard; A, B, C, D, and E. The classification scheme is based on the potential randomness of flooding across each site. A method is proposed for locating the primary diffluence (apex) of a distributary flow area. Texture curve analysis is used to locate distributary flow areas on the piedmont plain. Two alternative methods, topologic analysis and a multiple regression model, are presented for evaluating flood hazards on distributary flow areas in southern Arizona. Only eight of the sample sites studied strictly conformed with FEMA's assumption of an equal probability of flooding along a radial arc across the fan surface. The topologic analysis may be used to determine if the FEMA method is appropriate for a given site. A multiple regression model provides rough predictions of the degree of flood hazard based on morphometric and hydrologic variables.hydrology collectio