628 research outputs found

    Proteomic analysis of endothelial cold-adaptation

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    <p>Abstract</p> <p>Background</p> <p>Understanding how human cells in tissue culture adapt to hypothermia may aid in developing new clinical procedures for improved ischemic and hypothermic protection. Human coronary artery endothelial cells grown to confluence at 37°C and then transferred to 25°C become resistant over time to oxidative stress and injury induced by 0°C storage and rewarming. This protection correlates with an increase in intracellular glutathione at 25°C. To help understand the molecular basis of endothelial cold-adaptation, isolated proteins from cold-adapted (25°C/72 h) and pre-adapted cells were analyzed by quantitative proteomic methods and differentially expressed proteins were categorized using the DAVID Bioinformatics Resource.</p> <p>Results</p> <p>Cells adapted to 25°C expressed changes in the abundance of 219 unique proteins representing a broad range of categories such as translation, glycolysis, biosynthetic (anabolic) processes, NAD, cytoskeletal organization, RNA processing, oxidoreductase activity, response-to-stress and cell redox homeostasis. The number of proteins that decreased significantly with cold-adaptation exceeded the number that increased by 2:1. Almost half of the decreases were associated with protein metabolic processes and a third were related to anabolic processes including protein, DNA and fatty acid synthesis. Changes consistent with the suppression of cytoskeletal dynamics provided further evidence that cold-adapted cells are in an energy conserving state. Among the specific changes were increases in the abundance and activity of redox proteins glutathione S-transferase, thioredoxin and thioredoxin reductase, which correlated with a decrease in oxidative stress, an increase in protein glutathionylation, and a recovery of reduced protein thiols during rewarming from 0°C. Increases in S-adenosylhomocysteine hydrolase and nicotinamide phosphoribosyltransferase implicate a central role for the methionine-cysteine transulfuration pathway in increasing glutathione levels and the NAD salvage pathway in increasing the reducing capacity of cold-adapted cells.</p> <p>Conclusions</p> <p>Endothelial adaptation to mild-moderate hypothermia down-regulates anabolic processes and increases the reducing capacity of cells to enhance their resistance to oxidation and injury associated with 0°C storage and rewarming. Inducing these characteristics in a clinical setting could potentially limit the damaging effects of energy insufficiency due to ischemia and prevent the disruption of integrated metabolism at low temperatures.</p

    Assessment of optical, mechanical and nonlinear properties of potassium acid phthalate single crystal: a potential candidate for optoelectronic applications

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    A good optical quality semi-organic single crystal of Potassium Acid Phthalate (KAP) was harvested from aqueous solution by using slow evaporation solution growth technique (SEST) at ambient condition. The defect free single crystal of KAP was analyzed by different instrumentation techniques, for checking its compatibility for different applications. Its unit cell dimensions and phase purity was examined by powder X-ray diffraction (PXRD) and found that it crystallizes in orthorhombic with non-centrosymmetric in nature. The quality of the grown ingot was assessed by high resolution X-ray diffraction (HRXRD) technique and found that, the crystalline quality is better with less grain boundaries. Its optical properties were scrutinized by UV-vis., photoluminescence (PL) and time resolved photoluminescence (TRPL) measurements respectively. The mechanical stability of the grown crystal was tested by Vickers microhardness method and found that the grown crystal shows indentation size effect (ISE) which was explained using different theoretical models. Its third order nonlinear optical properties were studied by Z-scan measurement by using Ti:Sapphire laser as a source and determined its nonlinear absorption coefficient (beta) and it was found that the KAP crystal is one of the preferable choices for optical limiting applications

    SIRT3 Deacetylates and Activates OPA1 To Regulate Mitochondrial Dynamics during Stress

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    Mitochondrial morphology is regulated by the balance between two counteracting mitochondrial processes of fusion and fission. There is significant evidence suggesting a stringent association between morphology and bioenergetics of mitochondria. Morphological alterations in mitochondria are linked to several pathological disorders, including cardiovascular diseases. The consequences of stress-induced acetylation of mitochondrial proteins on the organelle morphology remain largely unexplored. Here we report that OPA1, a mitochondrial fusion protein, was hyperacetylated in hearts under pathological stress and this posttranslational modification reduced the GTPase activity of the protein. The mitochondrial deacetylase SIRT3 was capable of deacetylating OPA1 and elevating its GTPase activity. Mass spectrometry and mutagenesis analyses indicated that in SIRT3-deficient cells OPA1 was acetylated at lysine 926 and 931 residues. Overexpression of a deacetylation-mimetic version of OPA1 recovered the mitochondrial functions of OPA1-null cells, thus demonstrating the functional significance of K926/931 acetylation in regulating OPA1 activity. Moreover, SIRT3-dependent activation of OPA1 contributed to the preservation of mitochondrial networking and protection of cardiomyocytes from doxorubicin-mediated cell death. In summary, these data indicated that SIRT3 promotes mitochondrial function not only by regulating activity of metabolic enzymes, as previously reported, but also by regulating mitochondrial dynamics by targeting OPA1

    Spin flip scattering in magnetic junctions

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    Processes which flip the spin of an electron tunneling in a junction made up of magnetic electrodes are studied. It is found that: i) Magnetic impurities give a contribution which increases the resistance and lowers the magnetoresistance, which saturates at low temperatures. The conductance increases at high fields. ii) Magnon assisted tunneling reduces the magnetoresistance as T3/2T^{3/2}, and leads to a non ohmic contribution to the resistance which goes as V3/2V^{3/2}, iii) Surface antiferromagnetic magnons, which may appear if the interface has different magnetic properties from the bulk, gives rise to T2T^2 and V2V^2 contributions to the magnetoresistance and resistance, respectively, and, iv) Coulomb blockade effects may enhance the magnetoresistance, when transport is dominated by cotunneling processes.Comment: 5 page

    Work function changes in the double layered manganite La1.2Sr1.8Mn2O7

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    We have investigated the behaviour of the work function of La1.2Sr1.8Mn2O7 as a function of temperature by means of photoemission. We found a decrease of 55 +/- 10 meV in going from 60 K to just above the Curie temperature (125 K) of the sample. Above T_C the work function appears to be roughly constant. Our results are exactly opposite to the work function changes calculated from the double-exchange model by Furukawa, but are consistent with other measurements. The disagreement with double-exchange can be explained using a general thermodynamic relation valid for second order transitions and including the extra processes involved in the manganites besides double-exchange interaction.Comment: 6 pages, 4 figures included in tex

    A Survey of Cybersecurity of Digital Manufacturing

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    The Industry 4.0 concept promotes a digital manufacturing (DM) paradigm that can enhance quality and productivity, which reduces inventory and the lead time for delivering custom, batch-of-one products based on achieving convergence of additive, subtractive, and hybrid manufacturing machines, automation and robotic systems, sensors, computing, and communication networks, artificial intelligence, and big data. A DM system consists of embedded electronics, sensors, actuators, control software, and interconnectivity to enable the machines and the components within them to exchange data with other machines, components therein, the plant operators, the inventory managers, and customers. This article presents the cybersecurity risks in the emerging DM context, assesses the impact on manufacturing, and identifies approaches to secure DM

    Management of chronic obstructive pulmonary disease in India: a systematic review.

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    OBJECTIVES: Chronic diseases are fast becoming the largest health burden in India. Despite this, their management in India has not been well studied. We aimed to systematically review the nature and efficacy of current management strategies for chronic obstructive pulmonary disease (COPD) in India. METHODS: We used database searches (MEDLINE, EMBASE, IndMED, CENTRAL and CINAHL), journal hand-searches, scanning of reference lists and contact with experts to identify studies for systematic review. We did not review management strategies aimed at chronic diseases more generally, nor management of acute exacerbations. Due to the heterogeneity of reviewed studies, meta-analysis was not appropriate. Thus, narrative methods were used. SETTING: India. PARTICIPANTS: All adult populations resident in India. MAIN OUTCOME MEASURES: 1. Trialled interventions and outcomes 2. Extent and efficacy of current management strategies 3. Above outcomes by subgroup. RESULTS: We found information regarding current management - particularly regarding the implementation of national guidelines and primary prevention - to be minimal. This led to difficulty in interpreting studies of management strategies, which were varied and generally of positive effect. Data regarding current management outcomes were very few. CONCLUSIONS: The current understanding of management strategies for COPD in India is limited due to a lack of published data. Determination of the extent of current use of management guidelines, availability and use of treatment, and current primary prevention strategies would be useful. This would also provide evidence on which to interpret existing and future studies of management outcomes and novel interventions

    Diverse and healthy cropping systems trial protocol

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    On-Farm Research Trials are part of TAFSSA’s Work Package 2 (WP2) activities. WP2 emphasizes farm-and landscape-level interdisciplinary research to identify strategies to increase farmers’ profits and nutritional yields, conserve resources, and maintain or enhance ecological services, while also mitigating greenhouse gas (GHG) emissions from farms and agricultural landscapes. Going beyond typical agriculture-nutrition programs in South Asia we explore field-and landscape-scale crop and animal farm diversification options supporting multiple benefits, including potential nutritional yield, across environmental and socioeconomic gradients of rice and maize-based farming systems. Nalanda district of Bihar in eastern India has been selected as a learning site based on key information on food and nutrition security gaps, environmental stresses and climate challenges as well as the prevalence of commodities and farming systems that offer the greatest potential to achieve TAFSSA’s outcomes

    Human protein reference database—2006 update

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    Human Protein Reference Database (HPRD) () was developed to serve as a comprehensive collection of protein features, post-translational modifications (PTMs) and protein–protein interactions. Since the original report, this database has increased to >20 000 proteins entries and has become the largest database for literature-derived protein–protein interactions (>30 000) and PTMs (>8000) for human proteins. We have also introduced several new features in HPRD including: (i) protein isoforms, (ii) enhanced search options, (iii) linking of pathway annotations and (iv) integration of a novel browser, GenProt Viewer (), developed by us that allows integration of genomic and proteomic information. With the continued support and active participation by the biomedical community, we expect HPRD to become a unique source of curated information for the human proteome and spur biomedical discoveries based on integration of genomic, transcriptomic and proteomic data
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