1,601 research outputs found

    R468C as a Low-GWP Replacement of R410A in Fin-and-Tube Evaporators

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    A five-year review of quality of reporting of research using clinician surveys in high-ranked dermatology journals

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    Surveys of clinicians play a pivotal role in dermatology research, including to determine expert opinion, identify areas of uncertainty in clinical practice, define research priorities, investigate feasibility and explore areas of clinical equipoise. Despite the commonality of research involving surveys distributed to dermatologists, we previously identified the issue of poor‐quality survey design and lack of sufficient validation prior to distribution. Furthermore, a review of postal surveys of healthcare professionals from 1996 to 2005 has shown declining response rates, introducing potential non‐responder bias. To support stronger methodological quality and reporting of clinician survey, we developed a checklist for authors, based on our experience and published literature

    Assessment of Specific Yield and Storage Capacity of Groundwater using Borehole Log

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    The study aimed at evaluating the specific yield and storage capacity of groundwater in Chapai Nawabganj District of Bangladesh using borehole log data. The boring log samples from different layers were collected from each Upazila (administrative area) of the District. The specific yield of each Upazila was determined by the Cooper-Jacob method using Math lab software and storage of groundwater was then ascertained by a mathematical formula. The specific yield of the five Upazilas was determined and the values were found around 10 (%) which indicates good permeability of the areas, except Bholahat Upazila. The results illustrate that Nachole Upazila has a large storage volume, i.e., 49,305 Hec-m, but the other Upazilas have a storage capacity between 8000 to 18000 Hec-m. The storage capacity of the five Upazilas followed the order: Nachole>Nawabganj>Shibganj>Gomastapur> Bholahat. The highest number of DTWs at Nachole Upazila extracted 8848 Hec-m indicating excessive extraction concerning sustainable water management. A well-planned water resource management would have to be taken to achieve sustainable use of groundwater for irrigation aiming to achieve food security as well as an ecologically friendly environment. Keywords: Borehole, groundwater, storage, specific yield, storage capacity DOI: 10.7176/JEES/10-8-02 Publication date:August 31st 202

    Observation of Motion Dependent Nonlinear Dispersion with Narrow Linewidth Atoms in an Optical Cavity

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    As an alternative to state-of-the-art laser frequency stabilisation using ultra-stable cavities, it has been proposed to exploit the non-linear effects from coupling of atoms with a narrow transition to an optical cavity. Here we have constructed such a system and observed non-linear phase shifts of a narrow optical line by strong coupling of a sample of strontium-88 atoms to an optical cavity. The sample temperature of a few mK provides a domain where the Doppler energy scale is several orders of magnitude larger than the narrow linewidth of the optical transition. This makes the system sensitive to velocity dependent multi-photon scattering events (Dopplerons) that affect the cavity field transmission and phase. By varying the number of atoms and the intra-cavity power we systematically study this non-linear phase signature which displays roughly the same features as for much lower temperature samples. This demonstration in a relatively simple system opens new possibilities for alternative routes to laser stabilization at the sub 100 mHz level and superradiant laser sources involving narrow line atoms. The understanding of relevant motional effects obtained here has direct implications for other atomic clocks when used in relation with ultranarrow clock transitions.Comment: 9 pages (including 4 pages of Supplemental Information), 6 figures. Updated to correspond to the published versio

    Health conditions in adults with HIV compared with the general population:A population-based cross-sectional analysis

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    BACKGROUND: Life expectancy in adults with human immunodeficiency virus (HIV) has increased and managing other health conditions is increasingly important for patients and healthcare planning. The aim of this study was to examine the prevalence and association between different health conditions and HIV status. METHODS: We performed a cross-sectional analysis of adult UK Clinical Practice Research Datalink primary care electronic medical records linked to hospital admissions as of Nov 30, 2015. We examined 47 health condition groups and 304 physical and mental health conditions by HIV status, after adjustment for age, sex, social deprivation status using logistic regression. FINDINGS: There were 964 patients with HIV (61.7% male; 92.8% aged <65 years) and 941,113 non-HIV patients (49.4% male; 75.2% aged <65 years). Condition groups with the greatest prevalence in HIV that were also highly prevalent in adults without HIV included: lipid disorder (41.4% vs 40.2%), and hypertension (19.1% vs 24.6%). Following adjustment, 18 (37.5%) condition groups were more likely in adults with HIV and ten (20.8%) were less likely. Individual conditions that were less likely in adults with HIV included: atrial fibrillation (odds ratio [OR] 0.37 [95% CI 0.20–0.64]) and hypertension (OR_0.78 [0.65–0.94]); rheumatoid arthritis (OR 0.27 [0.05–0.84]); asthma (OR_0.65 (0.53–0.80]); and certain eye diseases such as macular degeneration (OR_0.30 [0.09–0.70]). Meanwhile individual conditions that were more likely included: liver fibrosis, sclerosis, and cirrhosis (OR_3.23 [1.85–5.20]); pulmonary embolism (OR_2.06 [1.15–3.36]); male infertility (OR_2.23 [1.50–3.16]) and female infertility (OR_2.01 [1.34–2.88]); bipolar disorder (OR_2.93 [1.52–5.05]) and depression (OR_1.49 [1.28–1.71]); cervical malignancy (OR_4.64 [1.15–12.15]); and infections. INTERPRETATION: Comorbidity is common in adults with HIV, with physical and mental health conditions spanning a wide spectrum. HIV management should consider multidisciplinary care models to provide optimal patient care. FUNDING: The project was funded by the Bart’s Charity; DRM was funded by a Wellcome Trust Clinical Research Career Development Fellowship; DRM and DMM received funding from the HDR-UK Precision therapeutics programme

    Multiple stochastic pathways in forced peptide-lipid membrane detachment

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    We have used high resolution AFM based dynamic force spectroscopy to investigate peptide-lipid membrane interactions by measuring the detachment (last-rupture) force distribution, P(F), and the corresponding force dependent rupture rate, k(F), for two different peptides and lipid bilayers. The measured quantities, which differed considerably for different peptides, lipid-membranes, AFM tips (prepared under identical conditions), and retraction speeds of the AFM cantilever, could not be described in terms of the standard theory, according to which detachment occurs along a single pathway, corresponding to a diffusive escape process across a free energy barrier. In particular, the prominent retraction speed dependence of k(F) was a clear indication that peptide-lipid membrane dissociation occurs stochastically along several detachment pathways. Thereby, we have formulated a general theoretical approach for describing P(F) and k(F), by assuming that peptide detachment from lipid membranes occurs, with certain probability, along a few dominant diffusive pathways. This new method was validated through a consistent interpretation of the experimental data. Furthermore, we have found that for moderate retraction speeds at intermediate force values, k(F) exhibits catch-bond behavior (i.e. decreasing detachment rate with increasing force). According to the proposed model this behavior is due to the stochastic mixing of individual detachment pathways which do not convert or cross during rupture. To our knowledge, such catch-bond mechanism has not been proposed and demonstrated before for a peptide-lipid interaction
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