SciCombinator

Discover the most talked about and latest scientific content & concepts.

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To determine the volume recombination at high dose-per-pulse in liquid ionization chambers (LIC) and to ascertain whether existing calculation methods verified in air-filled chambers may be used to calculate a correction factor.

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Long-term mechanical circulatory support (LT-MCS) is an important treatment modality for patients with severe heart failure. Different devices are available, and many-sometimes contradictory-observations regarding patient selection, surgical techniques, perioperative management and follow-up have been published. With the growing expertise in this field, the European Association for Cardio-Thoracic Surgery (EACTS) recognized a need for a structured multidisciplinary consensus about the approach to patients with LT-MCS. However, the evidence published so far is insufficient to allow for generation of meaningful guidelines complying with EACTS requirements. Instead, the EACTS presents an expert opinion in the LT-MCS field. This expert opinion addresses patient evaluation and preoperative optimization as well as management of cardiac and non-cardiac comorbidities. Further, extensive operative implantation techniques are summarized and evaluated by leading experts, depending on both patient characteristics and device selection. The faculty recognized that postoperative management is multidisciplinary and includes aspects of intensive care unit stay, rehabilitation, ambulatory care, myocardial recovery and end-of-life care and mirrored this fact in this paper. Additionally, the opinions of experts on diagnosis and management of adverse events including bleeding, cerebrovascular accidents and device malfunction are presented. In this expert consensus, the evidence for the complete management from patient selection to end-of-life care is carefully reviewed with the aim of guiding clinicians in optimizing management of patients considered for or supported by an LT-MCS device.

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The hydrogenated black TiO2 is receiving ever-increasing atten-tion, primarily due to the ability of capturing low energy photons in the solar spectrum and the highly efficient redox reactivity for solar-driven water splitting. However, an in-depth understanding of the physical insight into the redox reactivity is still missing. In this work, we conducted the density functional theory (DFT) study based on the model obtained from spectroscopic and aber-ration-corrected scanning transmission electron microscopy (AC-STEM) characterizations to reveal the synergy of H heteroatoms located at different surface sites where six-coordinated Ti (Ti6C) atom is converted from an inert trapping site to an interchange site of the photoexcited electrons. This in-depth understanding may be applicable to the rational design of highly efficient solar-harvesting catalysts.

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Two new zirconium based metal-organic frameworks with the composition [Zr6O4(OH)4(OAc)6(BDC)3] (CAU-26) and [Zr5O4(OH)4(OAc)4(BDC)2] (CAU-27) are reported, which were synthesized from acetic acid, a rarely utilized but green and sustainable solvent (BDC2-: 1,4-benzenedicarboxylate). Structure determination aided by automated electron diffraction tomography revealed that CAU-26 is composed of layers of well-known {Zr6O8} clusters interconnected by terephthalate ions. In contrast CAU-27 exhibits a three dimensional structure with a so far unknown type of one-dimensional inorganic building unit (IBU), which can be rationalized as condensed polyhedron-sharing chains of {Zr6O8} clusters. CAU-26 occurs as an intermediate of the CAU-27 synthesis and can be isolated easily, when reaction temperature and time are decreased. We were also able to synthesize two isoreticular derivatives of CAU-27 with extended linker molecules by implementing 4,4'-biphenyldicarboxylic acid (H2BPDC) and 5,5'-dicarboxy-2,2'-bipyridine (H2BIPY). All materials show high thermal and chemical stability as well as permanent microporosity. The excellent stability of CAU-27-BIPY was exploited to synthesize a performant iridium-supported heterogeneous MOF-based catalyst for the direct C-H borylation of arenes.

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To find more effective test and intervention measures, and to achieve the first 90 of the 90-90-90 target, this study was conducted for the first time to develop and assess an innovative HIV anonymous urine test service-based vending machine and Internet at universities of China. From June to December 2016, 11 vending machines were placed in 7 pilot universities in Beijing, Sichuan, Yunnan and Heilongjiang provinces. A total of 957 HIV urine collection kits were dispensed free and also through vending machines and 378 (39.5%) urine samples were returned and 376 (99.5%) of them were qualified to be tested for HIV antibody in professional laboratories. Participants searched for confidential test results using an ID code online. Only seven (1.86%) urine samples were positive. Monitoring data showed 67.8% (255/376) participants searched for test results online, 72.2% of kits were purchased in dormitory buildings and 27.8% were purchased in teaching buildings and 88.9% were purchased between 21:00 and 24:00. In conclusion, this study analyzes the acceptability, feasibility and effectiveness of HIV testing and intervention service.

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Designing hollow/porous structure is regarded as an effective approach to address the dramatic volumetric variation issue for Si-based anode materials in Li-ion batteries (LIBs). Pioneer works mainly focused on acid/alkali etching to create hollow/porous structures, which are, however, highly corrosive and may lead to complicated synthetic process. In this paper, a dual carbon conductive networks encapsulated hollow SiOx (DC-HSiOx) is fabricated through a green route where polyacrylic acid is adopted as an eco-friendly soft template. Low electrical resistance and integrated electrode structure can be maintained during cycles due to the dual carbon conductive networks distributed both on the surface of single particle formed by amorphous carbon and among particles constructed by reduced graphene oxide. Importantly, hollow space is reserved within SiOx spheres to accommodate the huge volumetric variation and shorten the transport pathway of Li+ ions. As a result, the DC-HSiOx composite delivers a large reversible capacity of 1113 mAh g-1 at 0.1 A g-1, an excellent cycling performance up to 300 cycles with capacity retention of 92.5% at 0.5 A g-1, and a good rate capability. Furthermore, the DC-HSiOx//LiNi0.8Co0.1Mn0.1O2 full cell exhibits high energy density (419 Wh kg-1) and superior cycling performance. These results render an opportunity for the unique DC-HSiOx composite as a potential anode material for use in high-performance LIBs.

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Hypercholesterolemia is a main risk factor of cardiovascular disease. Probiotics are a safe approach to reduce elevated cholesterol without any deleterious effect to human health. Saccharomyces boulardii CNCM I-745 probiotic properties are well documented in a context of intestinal dysbiosis. Recent in vitro and preclinical studies have suggested its potential effects on dyslipidemia. This is the first controlled study investigating the effects of S. boulardii CNCM I-745 on lipidemic profile and gut microbiota in a hamster hypercholesterolemic model. Daily administration (3 g/kg) of S. boulardii for 21 or 39 days in hamsters fed a 0.3% cholesterol-diet significantly reduced total plasma cholesterol (P<0.001) and increased faecal total cholesterol (P<0.05) compared to vehicle-treated animals. S. boulardii significantly modified the gut microbiota composition of the hamster fed a 0.3% cholesterol-diet. These microbial abundancy modifications of the microbiota were correlated to variations of lipidemic values or liver genes expressions. In particularly we found that abundance of g_Allobaculum, the most modified taxon after S. boulardii treatment (+236%; P<0.05), was correlated to variations in plasmatic lipoproteins level and ABCG5 hepatic gene expression. We also observed a not previously described correlation between the levels of g_Oxalobacter in the gut microbiota and total cholesterol plasma concentration. In conclusion, we confirmed the cholesterol-lowering effects of S. boulardii intake and we demonstrated for the first time the S. boulardii effect on gut microbiota in the context of hypercholesterolemia in hamsters. Our results provide new insights for a beneficial and safe approach of hypercholesterolemia treatment and could be considered for clinical development, alone or in addition to conventional treatment.

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To develop methods of extraction and purification of Cterminal NUDT9 homology domain of human transient receptor potential melastatin 2 (TRPM2) channel.

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To investigate the mechanism of congenital paramyotonia caused by human skeletal muscle voltage-gated sodium channel hNav1.4 mutant I1363T.

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To construct a three-dimensional structural model for the selectivity filter in the transient receptor pontential melastatin 8 (TRPM8) ion channel.