718 research outputs found

    A highly active and synergistic Pt/Mo<inf>2</inf>C/Al<inf>2</inf>O<inf>3</inf>catalyst for water-gas shift reaction

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    Catalysts consisting of Pt and Cu supported on Mo2C/η-Al2O3, Mo2C/γ-Al2O3or Mo2C were prepared and used for the low-temperature water gas shift reaction (WGSR). The catalysts were characterized by elemental analysis, powder X-ray diffraction (XRD), temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The catalysts were studied in water gas shift reaction with a reaction mixture containing 11% CO, 43% H2, 6% CO2, 21% H2O (real feed composition mixture from the reformer) and balance He, with a reaction temperature range of 180–300 °C at a space velocity (SV) of 125,000 h−1. Catalyst supports (η-Al2O3and γ-Al2O3), led to different synergetic effect between the two most active phases of Pt metal and Mo2C. Pt/Mo2C/η-Al2O3is a promising catalyst (44% conversion at 180 °C) due to the close interaction between Pt and Mo2C phases on the surface of the catalyst. The 4 wt% Pt-Mo2C showed the highest activity where the temperature at which 50% conversion observed was at only 180 °C with SV of 125,000 h−1and constant stability over 85 h

    Capturing the essence of folding and functions of biomolecules using Coarse-Grained Models

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    The distances over which biological molecules and their complexes can function range from a few nanometres, in the case of folded structures, to millimetres, for example during chromosome organization. Describing phenomena that cover such diverse length, and also time scales, requires models that capture the underlying physics for the particular length scale of interest. Theoretical ideas, in particular, concepts from polymer physics, have guided the development of coarse-grained models to study folding of DNA, RNA, and proteins. More recently, such models and their variants have been applied to the functions of biological nanomachines. Simulations using coarse-grained models are now poised to address a wide range of problems in biology.Comment: 37 pages, 8 figure

    Oxidative Stress Impairs the Heat Stress Response and Delays Unfolded Protein Recovery

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    Background: Environmental changes, air pollution and ozone depletion are increasing oxidative stress, and global warming threatens health by heat stress. We now face a high risk of simultaneous exposure to heat and oxidative stress. However, there have been few studies investigating their combined adverse effects on cell viability. Principal Findings: Pretreatment of hydrogen peroxide (H2O2) specifically and highly sensitized cells to heat stress, and enhanced loss of mitochondrial membrane potential. H 2O 2 exposure impaired the HSP40/HSP70 induction as heat shock response (HSR) and the unfolded protein recovery, and enhanced eIF2a phosphorylation and/or XBP1 splicing, land marks of ER stress. These H2O2-mediated effects mimicked enhanced heat sensitivity in HSF1 knockdown or knockout cells. Importantly, thermal preconditioning blocked H 2O 2–mediated inhibitory effects on refolding activity and rescued HSF1 +/+ MEFs, but neither blocked the effects nor rescued HSF1-/- MEFs. These data strongly suggest that inhibition of HSR and refolding activity is crucial for H2O2–mediated enhanced heat sensitivity. Conclusions: H2O2 blocks HSR and refolding activity under heat stress, thereby leading to insufficient quality control and enhancing ER stress. These uncontrolled stress responses may enhance cell death. Our data thus highlight oxidative stres

    Phylogenomics illuminates the backbone of the Myriapoda Tree of Life and reconciles morphological and molecular phylogenies

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    © The Author(s) 2017 This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. The attached file is the published version of the article

    The proteoglycan osteoglycin/mimecan is correlated with arteriogenesis

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    Arteriogenesis or collateral growth is able to compensate for the stenosis of major arteries. Using differential display RT-PCR on growing and quiescent collateral arteries in a rabbit femoral artery ligation model, we cloned the rabbit full-length cDNA of osteoglycin/mimecan. Osteoglycin was present in the adventitia of collateral arteries as a glycosylated protein without keratan sulfate side chains, mainly produced by smooth muscle cells (SMCs) and perivascular fibroblasts. Northern blot, Western blot, and immunohistochemistry confirmed a collateral artery-specific downregulation of osteoglycin from 6 h to 3 weeks after the onset of arteriogenesis. Treatment of primary SMCs with the arteriogenic protein fibroblast growth factor-2 (FGF-2) resulted in a similar reduction of osteoglycin expression as observed in vivo. Application of the FGF-2 inhibitor polyanethole sulfonic acid (PAS) blocked the downregulation of osteoglycin and interfered with arteriogenesis. From our study we conclude that downregulation of osteoglycin is a fundamental requirement for proper arteriogenesis

    Aggregating sequences that occur in many proteins constitute weak spots of bacterial proteostasis

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    Aggregation is a sequence-specific process, nucleated by short aggregation-prone regions (APRs) that can be exploited to induce aggregation of proteins containing the same APR. Here, we find that most APRs are unique within a proteome, but that a small minority of APRs occur in many proteins. When aggregation is nucleated in bacteria by such frequently occurring APRs, it leads to massive and lethal inclusion body formation containing a large number of proteins. Buildup of bacterial resistance against these peptides is slow. In addition, the approach is effective against drug-resistant clinical isolates of Escherichiacoli and Acinetobacterbaumannii, reducing bacterial load in a murine bladder infection model. Our results indicate that redundant APRs are weak points of bacterial protein homeostasis and that targeting these may be an attractive antibacterial strategy

    COVID Isolation Eating Scale (CIES): Analysis of the impact of confinement in eating disorders and obesity-A collaborative international study

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    Confinement during the COVID-19 pandemic is expected to have a serious and complex impact on the mental health of patients with an eating disorder (ED) and of patients with obesity. The present manuscript has the following aims: (1) to analyse the psychometric properties of the COVID Isolation Eating Scale (CIES), (2) to explore changes that occurred due to confinement in eating symptomatology; and (3) to explore the general acceptation of the use of telemedicine during confinement. The sample comprised 121 participants (87 ED patients and 34 patients with obesity) recruited from six different centres. Confirmatory Factor Analyses (CFA) tested the rational-theoretical structure of the CIES. Adequate goodness-of-fit was obtained for the confirmatory factor analysis, and Cronbach alpha values ranged from good to excellent. Regarding the effects of confinement, positive and negative impacts of the confinement depends of the eating disorder subtype. Patients with anorexia nervosa (AN) and with obesity endorsed a positive response to treatment during confinement, no significant changes were found in bulimia nervosa (BN) patients, whereas Other Specified Feeding or Eating Disorder (OSFED) patients endorsed an increase in eating symptomatology and in psychopathology. Furthermore, AN patients expressed the greatest dissatisfaction and accommodation difficulty with remote therapy when compared with the previously provided face-to-face therapy. The present study provides empirical evidence on the psychometric robustness of the CIES tool and shows that a negative confinement impact was associated with ED subtype, whereas OSFED patients showed the highest impairment in eating symptomatology and in psychopathology.This manuscript and research was supported by grants from the Ministeriode Economía y Competitividad (PSI2015-68701-R), Instituto de Salud Carlos III (ISCIII) (FIS PI14/00290/ INT19/00046nd PI17/01167) and co-funded by FEDER funds/European Regional Development Fund (ERDF), a way to build Europe. CIBERobn, CIBERsam and CIBERDEM are all initiatives of ISCIII. GMB is supported by a postdoctoral grant from FUNCIVA. This initiative is supported by Generalitat de Catalunya. LM is supported by a postdoctoral grant of the mexican institution Consejo Nacional de Ciencia y Tecnología (CONACYT). PPM was supported, in part, by a Portuguese Foundation for Science and Technology grant (POCI-01-0145-FEDER-028145). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript
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