Photocatalytic performance of Ta2O5/BiVO4 heterojunction for hydrogen production and methylene blue photodegradation

Forming semiconductor heterojunction is promising for improved photocatalytic performance due to synergistic combination of the best properties of each material. The present study reports a simple hydrothermal strategy to form n-n heterojunction of Ta2O5 nanotubes and BiVO4 microstructures. The Ta2O5/BiVO4 heterojunctions were characterized by Raman spectroscopy, UV-Vis diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and their photocatalytic activity was evaluated by hydrogen production and photodegradation of methylene blue (MB) dye in aqueous medium under AM 1.5 G (100 mW cm-2 ) condition. The heterojunctions have optical absorption in the visible region (200-500 nm) with crystal structures defined as monoclinic for BiVO4 and orthogonal for Ta2O5. For MB photodegradation, the Ta2O5/BiVO4 obtained via hydrothermal route showed a photodegradation of 72.3%, compared to 28.3% presented by the sample produced through the mechanical mixture, with the maintenance of 86.4% of its photocatalytic performance after 3 cycles of photodegradation. For H2 production, hydrothermally prepared Ta2O5/BiVO4 generated 10.2 μmol g-1 of H2 in 3 h; while Ta2O5 nanotubes and mechanical Ta2O5/BiVO4 mixture shows 6.82 and 2.80 μmol g-1, respectively. The results suggest that Ta2O5/BiVO4 is a promising material for applications in photocatalysis, promoting sustainable energy production through hydrogen and for the treatment of effluents containing cationic dyes

Clinical and genetic characterization of RDH12-retinal dystrophy in a South American cohort

Purpose: To characterize the largest cohort of individuals with RDH12-retinal dystrophy to date, and the first one from South America. // Design: Retrospective multicenter international study. // Subjects: 78 patients (66 families) with an inherited retinal dystrophy and biallelic variants in RDH12. // Methods: Review of clinical notes, ophthalmic images, and molecular diagnosis. // Main outcome measures: Visual function, retinal imaging and characteristics were evaluated and correlated. // Results: Thirty-seven individuals self-identified as Latino (51%) and 34 as White (47%). Mean age at the baseline visit was 19.8 ± 13 years old (6 months – 46 years old, median 18.5); 41 (53%) were children. Thirty-nine patients (50%) had subsequent visits, with mean follow-up of 6.8 + 7.3 years (0 – 29). Sixty-nine individuals (88%) had Leber congenital amaurosis/early onset severe retinal dystrophy (LCA/EOSRD). Macular and mid-peripheral atrophy was seen in all patients from 3 years of age. A novel retinal finding was a hyperautofluorescent ring in 2 young children with LCA. Eight variants (21%) were previously unreported and the most frequent variant was c.295C>A, p.Leu99Ile, present in 52 alleles of 32 probands. Individuals with LCA homozygous for p.Leu99Ile (31%) had a later age of onset, slower rate of BCVA decrease, the largest percentage of patients with mild visual impairment, and were predicted to reach legal blindness at an older age than the rest of the cohort. // Conclusions: By describing the largest molecularly confirmed cohort to date, improved understanding of disease progression was possible. Our detailed characterization aims to support research and the development of novel therapies that may have the potential to reduce or prevent vision loss in individuals with RDH12-associated retinal dystrophy

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

Análisis del sistema de gestión ambiental basado en la norma técnica colombiana ISO 14001:2015 para las empresas que realicen la fracturación hidráulica para la explotación de gas de lutitas

El artículo analiza la NTC ISO 14001: 2015 para las empresas que realizan fracturación hidráulica en yacimientos de lutitas en Colombia. Se utilizaron los requisitos de la norma NTC ISO 14001: 2015 aplicados a este tipo de empresas como fundamento metodológico. Se encontró que si bien la fracturación hidráulica puede traer beneficios para el sector petrolero, técnica que aumenta los impactos ambientales; de manera que la implementación de un sistema de gestión ambiental no es suficiente para controlar los impactos ambientales generados por la práctica, factor que cuestiona el papel de las organizaciones frente a la gestión de sus actividades

Effect of dexamethasone on rat plasma platelet activating factor acetylhydrolase during the perinatal period

It has been previously reported that the administration of dexamethasone (DEX) to adult rats increases the activity of plasma platelet-activating factor acetylhydrolase (PAF-AH) and prevents the development of intestinal necrosis caused by platelet activating factor (PAF) injection. In this report, we examined the effect of DEX administration on plasma PAF-AH activity during the perinatal period. Timed-pregnant rats received DEX (0.2-1.0 mg/kg/d) or normal saline (controls) on days 16-18 (early group) or days 18-20 (late group) of gestation. Maternal plasma PAF-AH activity was lower in late gestation than in postpartum period (P \u3c 0.001). Fetal and neonatal plasma PAF-AH activity was higher than maternal values (P \u3c 0.05). No changes of PAF-AH activity were seen in maternal, fetal or neonatal plasma after prenatal DEX administration at the aforementioned doses. A higher dose of DEX (1.3 mg/kg/d x 4 d) or cortisone (200 mg/kg/d) produced an elevation of maternal plasma PAF-AH activity (DEX 79.2 ± 3.0, cortisone 70.5 ± 1.9 vs. controls 49.4 ± 2.3 nmol/min/ml, P \u3c 0.01), but resulted in a high fetal mortality. Treatment of newborn rats with DEX (0.5 mg/kg/d) on days 1-3 after birth, increased plasma PAF-AH activity on day 4 (DEX 292 ± 5 versus controls 140 ± 9 nmol/min/ml, P \u3c 0.001) and day 6 (DEX 302 ± 12 versus controls 136 ± 6 nmol/min/ml, P \u3c 0.001). Postnatal administration of DEX increases the plasma PAF-AH activity in the rat. Only high doses of prenatal corticosteroids that cause fetal death can elevate maternal plasma PAF-AH activity

Consumption of CH3Cl, CH3Br, and CH3I and emission of CHCl3, CHBr3, and CH2Br2 from the forefield of a retreating Arctic glacier

The Arctic is one of the most rapidly warming regions of the Earth, with predicted temperature increases of 5–7 ∘C and the accompanying extensive retreat of Arctic glacial systems by 2100. Retreating glaciers will reveal new land surfaces for microbial colonisation, ultimately succeeding to tundra over decades to centuries. An unexplored dimension to these changes is the impact upon the emission and consumption of halogenated organic compounds (halocarbons). Halocarbons are involved in several important atmospheric processes, including ozone destruction, and despite considerable research, uncertainties remain in the natural cycles of some of these compounds. Using flux chambers, we measured halocarbon fluxes across the glacier forefield (the area between the present-day position of a glacier's ice-front and that at the last glacial maximum) of a high-Arctic glacier in Svalbard, spanning recently exposed sediments (<10 years) to approximately 1950-year-old tundra. Forefield land surfaces were found to consume methyl chloride (CH3Cl) and methyl bromide (CH3Br), with both consumption and emission of methyl iodide (CH3I) observed. Bromoform (CHBr3) and dibromomethane (CH2Br2) have rarely been measured from terrestrial sources but were here found to be emitted across the forefield. Novel measurements conducted on terrestrial cyanobacterial mats covering relatively young surfaces showed similar measured fluxes to the oldest, vegetated tundra sites for CH3Cl, CH3Br, and CH3I (which were consumed) and for CHCl3 and CHBr3 (which were emitted). Consumption rates of CH3Cl and CH3Br and emission rates of CHCl3 from tundra and cyanobacterial mat sites were within the ranges reported from older and more established Arctic tundra elsewhere. Rough calculations showed total emissions and consumptions of these gases across the Arctic were small relative to other sources and sinks due to the small surface area represented by glacier forefields. We have demonstrated that glacier forefields can consume and emit halocarbons despite their young age and low soil development, particularly when cyanobacterial mats are present

Facile MOF Support Improvement in Synergy with Light Acceleration for Efficient Nanoalloy-Catalyzed H2 Production from Formic Acid

International audienceHydrogen (H2) generation and storage are actively investigated to provide a green source of energy, and formic acid (HCOOH), a major product obtained from the biomass, is regarded as a productive source of H2. Therefore, improvements in heterogeneous catalysts are called for. Here, a novel type of catalyst support is proposed involving simple addition of the mixture of metal ion precursors to core-shell ZIF-8@ZIF-67, followed by reduction with NaBH4, with performances surpassing those obtained using nanocatalysts in ZIF-8 or ZIF-67. The nanocatalysts PdxAg were optimized with ZIF-8@Pd2Ag1@ZIF-67 under visible-light illumination for selective HCOOH dehydrogenation involving a turnover frequency value of 430 h-1 under light irradiation at 353 K. These results also reveal the crucial roles of the Pd sites electronically promoted in the presence of visible by the plasmon resonance and the core-shell light by Ag plasmon advantageous MOF structure. In order to examine the potential of extending this catalyst improvement principle to other catalytic reactions, 4nitrophenol reduction, a benchmarking model of catalytic reaction, was tested, and the results also confirmed the superiority of the performance of ZIF-8@Pd2Ag1@ZIF-67 over Pd2Ag1@ZIF-8 and Pd2Ag1@ZIF-67, confirming the interest in the novel catalyst design

Bile Salts Enhance the Susceptibility of the Peach Allergenic Lipid Transfer Protein, Pru p 3, to in vitro gastrointestinal proteolysis

Abstract Sensitisation to the lipid transfer protein Pru p 3 is associated with severe allergic reactions to peach, the proteins stability being thought to play a role in its allergenicity. Lipid binding increases susceptibility of Pru p 3 to digestion and so the impact of bile salts on the in vitro gastrointestinal digestibility of Pru p 3 was investigated and digestion products mapped by SDS-PAGE and mass spectrometry. Bile salts enhanced the digestibility of Pru p 3 resulting in an ensemble of around 100 peptides spanning the protein’s sequence which were linked by disulphide bonds into structures of ~ 5–6 kDa. IgE binding studies with a serum panel from peach allergic subjects showed digestion reduced, but did not abolish, the IgE reactivity of Pru p 3. These data show the importance of including bile salts in vitro digestion systems and emphasise the need to profile of digestion in a manner that allows identification of immunologically relevant disulphide-linked peptide aggregates

Misalignment of the knees: Does it affect human stance stability

Introduction: Data describing the relationships between postural alignment and stance stability are scarce and controversial. Objective: The aim of this study was to evaluate the effects of sensory disturbances on knee alignment in upright stance and the effects of knee hyperextension on stance stability. Method: Kinetic and kinematic data of 23 healthy adult women were collected while quietly standing in four sensory conditions. Kinematic data: knee angle (dependent variables) variations were analyzed across sensory conditions. Kinetic data: as subjects with hyperextended knees showed a clear tendency to flex their knees as balance challenge increased, center of pressure (COP) parameters (dependent variables) were analyzed in each sensory condition among trial sub-groups: Aligned-Trials (knee angle 180°) and Adjusted-Trials (>180° initially, turned <180° under challenging conditions). Results: Differences were found in mean velocity of COP in two conditions showing that knee alignment can affect stance stability. Conclusion: Knee hyperextension is a transient condition changing under postural challenges. Knee hyperextension affected postural control as mean velocity was the highest in the hyperextended group in natural standing sensory condition and lowest with sensory disturbance. © 2009 Elsevier Ltd