The effect of Mg location on Co-Mg-Ru/γ-Al2O3 Fischer–Tropsch catalysts

© 2016 The Author(s) Published by the Royal Society. All rights reserved.The effectiveness of Mg as a promoter of Co-Ru/γ-Al2O3 Fischer-Tropsch catalysts depends on how and when the Mg is added. When the Mg is impregnated into the support before the Co and Ru addition, some Mg is incorporated into the support in the form of MgxAl2O3+x if the material is calcined at 550°C or 800°C after the impregnation, while the remainder is present as amorphous MgO/MgCO3 phases. After subsequent Co-Ru impregnation MgxCo3-xO4 is formed which decomposes on reduction, leading to Co(0) particles intimately mixed with Mg, as shown by high-resolution transmission electron microscopy. The process of impregnating Co into an Mg-modified support results in dissolution of the amorphous Mg, and it is this Mg which is then incorporated into MgxCo3-xO4. Acid washing or higher temperature calcination after Mg impregnation can remove most of this amorphous Mg, resulting in lower values of x in MgxCo3-xO4. Catalytic testing of these materials reveals that Mg incorporation into the Co oxide phase is severely detrimental to the site-Time yield, while Mg incorporation into the support may provide some enhancement of activity at high temperature

Impact of co-adsorbed oxygen on crotonaldehyde adsorption over gold nanoclusters : a computational study

Crotonaldehyde (2-butenal) adsorption over gold sub-nanometer particles, and the influence of co-adsorbed oxygen, has been systematically investigated by computational methods. Using density functional theory, the adsorption energetics of crotonaldehyde on bare and oxidised gold clusters (Au13, d = 0.8 nm) were determined as a function of oxygen coverage and coordination geometry. At low oxygen coverage, sites are available for which crotonaldehyde adsorption is enhanced relative to bare Au clusters by 10 kJ mol−1. At higher oxygen coverage, crotonaldehyde is forced to adsorb in close proximity to oxygen weakening adsorption by up to 60 kJ mol−1 relative to bare Au. Bonding geometries, density of states plots and Bader analysis, are used to elucidate crotonaldehyde bonding to gold nanoparticles in terms of partial electron transfer from Au to crotonaldehyde, and note that donation to gold from crotonaldehyde also becomes significant following metal oxidation. At high oxygen coverage we find that all molecular adsorption sites have a neighbouring, destabilising, oxygen adatom so that despite enhanced donation, crotonaldehyde adsorption is always weakened by steric interactions. For a larger cluster (Au38, d = 1.1 nm) crotonaldehyde adsorption is destabilized in this way even at a low oxygen coverage. These findings provide a quantitative framework to underpin the experimentally observed influence of oxygen on the selective oxidation of crotyl alcohol to crotonaldehyde over gold and gold–palladium alloys

Impact of co-adsorbed oxygen on crotonaldehyde adsorption over gold nanoclusters : a computational study

Crotonaldehyde (2-butenal) adsorption over gold sub-nanometer particles, and the influence of co-adsorbed oxygen, has been systematically investigated by computational methods. Using density functional theory, the adsorption energetics of crotonaldehyde on bare and oxidised gold clusters (Au13, d = 0.8 nm) were determined as a function of oxygen coverage and coordination geometry. At low oxygen coverage, sites are available for which crotonaldehyde adsorption is enhanced relative to bare Au clusters by 10 kJ mol−1. At higher oxygen coverage, crotonaldehyde is forced to adsorb in close proximity to oxygen weakening adsorption by up to 60 kJ mol−1 relative to bare Au. Bonding geometries, density of states plots and Bader analysis, are used to elucidate crotonaldehyde bonding to gold nanoparticles in terms of partial electron transfer from Au to crotonaldehyde, and note that donation to gold from crotonaldehyde also becomes significant following metal oxidation. At high oxygen coverage we find that all molecular adsorption sites have a neighbouring, destabilising, oxygen adatom so that despite enhanced donation, crotonaldehyde adsorption is always weakened by steric interactions. For a larger cluster (Au38, d = 1.1 nm) crotonaldehyde adsorption is destabilized in this way even at a low oxygen coverage. These findings provide a quantitative framework to underpin the experimentally observed influence of oxygen on the selective oxidation of crotyl alcohol to crotonaldehyde over gold and gold–palladium alloys

The Rewiring of Ubiquitination Targets in a Pathogenic Yeast Promotes Metabolic Flexibility, Host Colonization and Virulence

Funding: This work was funded by the European Research Council [http://erc.europa.eu/], AJPB (STRIFE Advanced Grant; C-2009-AdG-249793). The work was also supported by: the Wellcome Trust [www.wellcome.ac.uk], AJPB (080088, 097377); the UK Biotechnology and Biological Research Council [www.bbsrc.ac.uk], AJPB (BB/F00513X/1, BB/K017365/1); the CNPq-Brazil [http://cnpq.br], GMA (Science without Borders fellowship 202976/2014-9); and the National Centre for the Replacement, Refinement and Reduction of Animals in Research [www.nc3rs.org.uk], DMM (NC/K000306/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgments We thank Dr. Elizabeth Johnson (Mycology Reference Laboratory, Bristol) for providing strains, and the Aberdeen Proteomics facility for the biotyping of S. cerevisiae clinical isolates, and to Euroscarf for providing S. cerevisiae strains and plasmids. We are grateful to our Microscopy Facility in the Institute of Medical Sciences for their expert help with the electron microscopy, and to our friends in the Aberdeen Fungal Group for insightful discussions.Peer reviewedPublisher PD

A new species of Sellaphora (Sellaphoraceae) from Hannaberry Lake, Arkansas, U.S.A.

A new small-size species of Sellaphora was found in sediments from Hannaberry Lake, Arkansas, during the National Lakes Assessment project conducted by the United States Environmental Protection Agency. The species was studied with light microscopy and scanning electron microscopy. It differs from previously reported Sellaphora species by its small and delicate frustule with striation irresolvable in light microscopy. Here we present details on its morphology and size variation and report the characteristics of the lake where the species was found

Measurement of the vector and tensor analyzing powers for Dp-elastic scattering at the energy of 800 MeV

The vector Ay and tensor analyzing powers Ayy and Axx for dp-elastic scattering were measured at the energy of 800 MeV and at the angular range from 60° to 135° in the center-of-mass system at the JINR Nuclotron. The experimental data are compared with the calculations obtained within framework of relativistic multiple scattering approac

Expression variability of co-regulated genes differentiates Saccharomyces cerevisiae strains

Background: Saccharomyces cerevisiae (Baker’s yeast) is found in diverse ecological niches and is characterized by high adaptive potential under challenging environments. In spite of recent advances on the study of yeast genome diversity, little is known about the underlying gene expression plasticity. In order to shed new light onto this biological question, we have compared transcriptome profiles of five environmental isolates, clinical and laboratorial strains at different time points of fermentation in synthetic must medium, during exponential and stationary growth phases. Results: Our data unveiled diversity in both intensity and timing of gene expression. Genes involved in glucose metabolism and in the stress response elicited during fermentation were among the most variable. This gene expression diversity increased at the onset of stationary phase (diauxic shift). Environmental isolates showed lower average transcript abundance of genes involved in the stress response, assimilation of nitrogen and vitamins, and sulphur metabolism, than other strains. Nitrogen metabolism genes showed significant variation in expression among the environmental isolates. Conclusions: Wild type yeast strains respond differentially to the stress imposed by nutrient depletion, ethanol accumulation and cell density increase, during fermentation of glucose in synthetic must medium. Our results support previous data showing that gene expression variability is a source of phenotypic diversity among closely related organisms.Fundação para a Ciência e TecnologiaThe authors wish to thank Adega Cooperativa da Bairrada, Cantanhede, Portugal, for providing the commercial strains

Mild Traumatic Brain Injury: Epidemiology, Management, Outcome

Introduction: Mild traumatic brain injuries represent 80% of the total traumatic brain injuries. Their management is conducted as recommended by EBIC (European Brain Injury Consortium) or WFNS (World Federation of Neurosurgical Societies).The aim of the study is to analyze the management of patients with mild traumatic brain injuries who present at the Emergency Department (ED), of the admitted ones, the paraclinical investigations used and the cerebral lesions which these identify.Material and methods: During a 3 months period, 533 patients with mild traumatic brain injuries presented at the ED. We have followed these patients regarding the demographic data, the causes that led to the mild traumatic brain injuries and the paraclinical investigations used. Regarding the admitted patients, we have taken into consideration risk factors, neurological symptoms, the need to repeat a paraclinical investigation, their management and outcome.Results: Out of the 533 patients who presented at the ED, 248 (65%) were adults and 158 (29.64%) were third age patients. The remaining 27 (5%) were aged between 0-18 years old. Male patients (359; 67%) were more frequently affected than female patients (174; 32.6%). The top three causes were aggressions (57%), car accidents (27%) and same level falls (6.3%). The patients were investigated by skull X-rays (47.8%) and cerebral CT (computed tomography) scans (52.35%).Out of the total number of patients, 198 were admitted; these had the following risk factors: age > 65 years old (31%), alcohol use (18.6%), seizures (7.57%) and the following clinical symptoms: headaches (71%), vomiting (9.6%), dizziness (36.8%), loss of consciousness (31.8%).Out of the admitted patients, only 12 presented cerebral lesions: hemorrhagic brain contusions (n=5), small subdural blood collections (n=3), traumatic subarachnoid hemorrhages (n=2), acute subdural hematoma (n=1) and intraventricular hemorrhage (n=1).The patient with acute subdural hematoma was operated on and had a favorable outcome.The patient with intraventricular hemorrhage, who was 90 years old and presented with coagulopathy, has deceased.All the other patients were discharged after a mean hospitalization period of 3 days.Conclusions: Out of the patients with mild traumatic brain injuries, only a small number present cerebral lesions. For their diagnosis, expensive paraclinical investigations are used in both the ED and the neurosurgical department.Careful monitoring of the evolution of the neurological status and performing a cerebral CT scan only in case of neurological deterioration would save resources that could be targeted for the therapeutic stage

First results on the energy scan of the vector Ay and tensor Ayy and Axx analyzing powers in deuteronproton elastic scattering at Nuclotron

New results on the vector A y and tensor Ayy and Axx analyzing powers in deuteronproton elastic scattering obtained at Nuclotron in the energy range 400-1800 MeV are presented. These data have been obtained in 2016-2017 at DSS setup at internal target station using polarized deuteron beam from new source of polarized ions. The preliminary data on the deuteron analyzing powers in in the wide energy range demonstrate the sensitivity to the shortrange spin structure of the nucleon-nucleon correlation