42 research outputs found

    Antifouling pseudo-zwitterionic poly(vinylidene fluoride) membranes with efficient mixed-charge surface grafting via glow dielectric barrier discharge plasma-induced copolymerization

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    This work reports on the glow dielectric barrier discharge (GDBD) plasma-induced surface grafting of poly(vinylidene fluoride) (PVDF) membranes with mixed-charge copolymers of [2-(methacryloyloxy)ethyl] trimethylammonium (TMA) and sulfopropyl methacrylate (SA). The aim is to investigate the antifouling properties and the hemocompatibility of this system. We first characterize the physico-chemical properties of the membranes. With SA alone in the coating solution, efficient grafting cannot be achieved as monomer is blown away during grafting. Membranes grafted with a mixture of SA and TMA, or TMA alone do not meet this problem and grafting density ranged between 0.29 and 0.41 mg/cm2. Bovine-serum-albumin and lysozyme adsorption tests (70% reduction) and Escherichia coli attachment test (annihilation of adhesion) unveil that pseudo-zwitterionic PVDF membranes are very efficient to reduce biofouling in static condition. Different fouling resistance behaviors are observed in dynamic conditions. Permeability of virgin membranes progressively decreases over the cycles, arising from a gradual pore blockage and irreversible fouling. All potential adsorption sites of pseudo-zwitterionic membrane and membrane with positive charge-bias are fouled after the first cycle, and flux recovery is maximal in the following cycles. This behavior is ascribed to the lack of homogeneity of the surface grafting. Finally, pseudo-zwitterionic membranes are hemocompatible (resistance to blood cells, low hemolysis activity). Provided a better tuning of surface uniformity, the method and system presented in this work are a promising approach to the new generation of antifouling mixed-charge membranes for water treatment or blood contacting devices

    Isomer Spectroscopy of Neutron-rich 165,167Tb

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    Open Access JournalWe present information on the excited states in the prolate-deformed, neutron-rich nuclei 165;167Tb100;102. The nuclei of interest were synthesized following in-flight fission of a 345 MeV per nucleon 238U primary beam on a 2 mm 9Be target at the Radioactive Ion-Beam Factory (RIBF), RIKEN, Japan. The exotic nuclei were separated and identified event-by-event using the BigRIPS separator, with discrete energy gamma-ray decays from isomeric states with half-lives in the _s regime measured using the EURICA gamma-ray spectrometer. Metastable-state decays are identified in 165Tb and 167Tb and interpreted as arising from hindered E1 decay from the 7/2-[523] single quasi-proton Nilsson configuration to rotational states built on the 3/2-[411] single quasi-proton ground state. These data correspond to the first spectroscopic information in the heaviest, odd-A terbium isotopes reported to date and provide information on proton Nilsson configurations which reside close to the Fermi surface as the 170Dy doubly-midshell nucleus is approached.postprin

    Prevalence and progression of diabetic nephropathy in South Asian, white European and African Caribbean people with type 2 diabetes: A systematic review and meta-analysis

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    AIMS: To conduct a systematic review and meta-analysis of published observational evidence to assess the difference in the prevalence and progression of diabetic nephropathy, and the development of end-stage renal disease (ESRD) in people from three different ethnic groups with type 2 diabetes (T2DM). MATERIALS AND METHODS: Relevant studies were identified in a literature search of MEDLINE, EMBASE and reference lists of relevant studies published up to May 2018. We decided a priori that there were no differences in the prevalence and progression of diabetic nephropathy, and the development of ESRD in the three ethnicities with T2DM. Pooled relative risks of microalbuminuria by ethnicity were estimated by fitting three random effects meta-analyses models. A narrative synthesis of the nephropathy progression in the studies was carried out. The review was registered in PROSPERO (CRD42018107350). RESULTS: Thirty-two studies with data on 153 827 unique participants were eligible for inclusion in the review. The pooled prevalence ratio of microalbuminuria in South Asian compared with white European participants was 1.14 (95% confidence interval [CI] 0.99, 1.32; P = 0.065), while for African Caribbean vs South Asian participants the pooled prevalence ratio was 1.08 (95% CI 0.93, 1.24; P = 0.327). Results for renal decline were inconsistent, with preponderance towards a high rate of disease progression in South Asian compared with white participants. The estimated pooled incidence rate ratio (IRR) for ESRD was significantly higher in African Caribbean vs white European participants: 2.75 (95% CI 2.01, 3.48; P < 0.001). CONCLUSION: The results of this review did not show a significant link between ethnicity (South Asian, white European and African Caribbean) and the prevalence of microalbuminuria; however, the IRR for ESRD in African Caribbean compared with white European participants was significantly higher. Further research is needed to explore the potential non-albuminuric pathways of progression to ESRD

    The association of weight change and all-cause mortality in older adults: a systematic review and meta-analysis

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    Abstract Objective there may be age-related differences in the impact of weight change on health. This study systematically reviewed the evidence on the relationship between weight change and all-cause mortality in adults aged 65 years and older. Methods MEDLINE, EMBASE and CINAHL were searched from inception to 11 June 2020, PROSPERO CRD 42019142268. We included observational studies reporting on the association between weight change and all-cause mortality in older community-dwelling adults. A random-effects meta-analysis was performed to calculate pooled hazard ratios and scored based on the Agency for Healthcare Research and Quality guidelines. Results a total of 30 studies, including 1,219,279 participants with 69,255 deaths, demonstrated that weight loss was associated with a 59% increase in mortality risk (hazard ratio (HR): 1.59; 95% confidence interval (CI): 1.45–1.74; P &amp;lt; 0.001). Twenty-seven studies that reported outcomes for weight gain (1,210,116 participants with 65,481 deaths) indicated that weight gain was associated with a 10% increase in all-cause mortality (HR: 1.10; 95%CI: 1.02, 1.17; P = 0.01). Four studies investigated weight fluctuation (2,283 events among 6,901 participants), which was associated with a 63% increased mortality risk (HR: 1.66; 95%CI: 1.28, 2.15). No evidence of publication bias was observed (all P &amp;gt; 0.05). Conclusion for community-dwelling older adults, weight changes (weight loss, gain or weight fluctuation) are associated with an increased risk of all-cause mortality risk relative to stable weight. Further research is needed to determine whether these associations vary depending upon initial weight, and whether or not the weight loss/gain was intentional. </jats:sec

    COVID-19: Factors associated with psychological distress, fear, and coping strategies among community members across 17 countries

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    Abstract Background The current pandemic of COVID-19 impacted the psychological wellbeing of populations globally. Objectives We aimed to examine the extent and identify factors associated with psychological distress, fear of COVID-19 and coping. Methods We conducted a cross-sectional study across 17 countries during Jun-2020 to Jan-2021. Levels of psychological distress (Kessler Psychological Distress Scale), fear of COVID-19 (Fear of COVID-19 Scale), and coping (Brief Resilient Coping Scale) were assessed. Results A total of 8,559 people participated; mean age (&plusmn;SD) was 33(&plusmn;13) years, 64% were females and 40% self-identified as frontline workers. More than two-thirds (69%) experienced moderate-to-very high levels of psychological distress, which was 46% in Thailand and 91% in Egypt. A quarter (24%) had high levels of fear of COVID-19, which was as low as 9% in Libya and as high as 38% in Bangladesh. More than half (57%) exhibited medium to high resilient coping; the lowest prevalence (3%) was reported in Australia and the highest (72%) in Syria. Being female (AOR 1.31 [95% CIs 1.09-1.57]), perceived distress due to change of employment status (1.56 [1.29-1.90]), comorbidity with mental health conditions (3.02 [1.20-7.60]) were associated with higher levels of psychological distress and fear. Doctors had higher psychological distress (1.43 [1.04-1.97]), but low levels of fear of COVID-19 (0.55 [0.41-0.76]); nurses had medium to high resilient coping (1.30 [1.03-1.65]). Conclusions The extent of psychological distress, fear of COVID-19 and coping varied by country; however, we identified few higher risk groups who were more vulnerable than others. There is an urgent need to prioritise health and well-being of those people through well-designed intervention that may need to be tailored to meet country specific requirements. </jats:sec
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