2,717 research outputs found

    Nocturnal CPAP improves walking capacity in COPD patients with obstructive sleep apnoea

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    BACKGROUND: Exercise limitation is an important issue in patients with chronic obstructive pulmonary disease (COPD), and it often co-exists with obstructive sleep apnoea (overlap syndrome). This study examined the effects of nocturnal continuous positive airway pressure (CPAP) treatment on walking capacity in COPD patients with or without obstructive sleep apnoea. METHODS: Forty-four stable moderate-to-severe COPD patients were recruited and completed this study. They all underwent polysomnography, CPAP titration, accommodation, and treatment with adequate pressure. The incremental shuttle walking test was used to measure walking capacity at baseline and after two nights of CPAP treatment. Urinary catecholamine and heart rate variability were measured before and after CPAP treatment. RESULTS: After two nights of CPAP treatment, the apnoea-hypopnoea index and oxygen desaturation index significantly improved in both overlap syndrome and COPD patients, however these changes were significantly greater in the overlap syndrome than in the COPD group. Sleep architecture and autonomic dysfunction significantly improved in the overlap syndrome group but not in the COPD group. CPAP treatment was associated with an increased walking capacity from baseline from 226.4 ± 95.3 m to 288.6 ± 94.6 m (P < 0.05), and decreased urinary catecholamine levels, pre-exercise heart rate, oxygenation, and Borg scale in the overlap syndrome group. An improvement in the apnoea-hypopnoea index was an independent factor associated with the increase in walking distance (r = 0.564). CONCLUSION: Nocturnal CPAP may improve walking capacity in COPD patients with overlap syndrome. TRIAL REGISTRATION: NCT0091426

    Development of a deep learning-based tool to assist wound classification

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    This paper presents a deep learning-based wound classification tool that can assist medical personnel in non-wound care specialization to classify five key wound conditions, namely deep wound, infected wound, arterial wound, venous wound, and pressure wound, given color images captured using readily available cameras. The accuracy of the classification is vital for appropriate wound management. The proposed wound classification method adopts a multi-task deep learning framework that leverages the relationships among the five key wound conditions for a unified wound classification architecture. With differences in Cohen's kappa coefficients as the metrics to compare our proposed model with humans, the performance of our model was better or non-inferior to those of all human medical personnel. Our convolutional neural network-based model is the first to classify five tasks of deep, infected, arterial, venous, and pressure wounds simultaneously with good accuracy. The proposed model is compact and matches or exceeds the performance of human doctors and nurses. Medical personnel who do not specialize in wound care can potentially benefit from an app equipped with the proposed deep learning model

    Single atom and defect engineering of CuO for efficient electrochemical reduction of CO 2 to C 2 H 4

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    Electrochemical CO2 transformation to high‐value ethylene (C2H4) at high currents and efficiencies is desired and yet remains a grand challenge. We show for the first time that coupling single Sb atoms and oxygen vacancies of CuO enable synergistic electrocatalytic reduction of CO2 to C2H4 at low overpotentials. Highly dispersed Sb atoms occupying metal substitutional sites of CuO are synthesized under mild conditions. The overall CO2 reduction faradaic efficiency (FE) reaches 89.3 ± 1.1% with an FE toward C2H4 exceeding 58.4% at a high‐current density of 500 mA/cm2. Addition of the p‐block metal is found to induce transformation of CuO from flakes to nanoribbons rich in nanoholes and oxygen vacancies, greatly enhancing CO2 adsorption and activation while suppressing hydrogen evolution. Further density functional theory calculations with in situ X‐ray diffraction reveal that combining Sb sites and oxygen vacancies prominently lessen the dimerization energy of adsorbed CO intermediate, thus boosting the conversion of CO2 to produce C2H4. This study provides a new perspective for promoting selective C–C coupling for electrochemical CO2 reduction

    Particulate Matter Promotes In Vitro Receptor‐Recognizable Low‐Density Lipoprotein Oxidation and Dysfunction of Lipid Receptors

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    Particulate matter may promote cardiovascular disease, possibly as a consequence of its oxidative potential. Studies using susceptible animals indicate that particulate matter aggravates atherosclerosis by increasing lipid/macrophage content in plaques. Macrophage lipid uptake requires oxidized low‐density lipoprotein and scavenger receptors; same receptors are involved in particulate matter uptake. We studied in vitro particulate matter potential to oxidize low‐density lipoproteins and subsequent cell uptake through scavenger receptors. Particulate matter‐induced low‐density lipoproteins oxidation was evaluated by the thiobarbituric acid assay. Binding/internalization was tested in wild type and scavenger receptor–transfected Chinese hamster ovary cells, and in RAW264.7 cells using fluorescently labeled low‐density lipoproteins. Dose‐dependent binding/internalization only occurred in scavenger receptor–transfected Chinese hamster ovary cells and RAW264.7 cells. Competition binding/internalization using particles showed that particulate matter induced decreased binding (∼50%) and internalization (∼70%) of particle‐oxidized low‐density lipoproteins and native low‐density lipoproteins. Results indicate that particulate matter was capable of oxidizing low‐density lipoproteins, favoring macrophage internalization, and also altered scavenger and low‐density lipoproteins receptor function. © 2012 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:69‐76, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.21452Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/96297/1/jbt21452.pd

    Probing Specific Interaction Forces Between Human IgG and Rat Anti-Human IgG by Self-Assembled Monolayer and Atomic Force Microscopy

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    Interaction forces between biological molecules such as antigen and antibody play important roles in many biological processes, but probing these forces remains technically challenging. Here, we investigated the specific interaction and unbinding forces between human IgG and rat anti-human IgG using self assembled monolayer (SAM) method for sample preparation and atomic force microscopy (AFM) for interaction force measurement. The specific interaction force between human IgG and rat anti-human IgG was found to be 0.6–1.0 nN, and the force required for unbinding a single pair of human IgG and rat anti-human IgG was calculated to be 144 ± 11 pN. The results are consistent with those reported in the literatures. Therefore, SAM for sample preparation combined with AFM for interaction measurement is a relatively simple, sensitive and reliable technique to probe specific interactions between biological molecules such as antigen and antibody

    Mini Black Holes in the first year of the LHC

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    The experimental signatures of TeV-mass black hole (BH) formation in heavy ion collisions at the LHC is examined. We find that the black hole production results in a complete disappearance of all very high pTp_T ({>500> 500} GeV) back-to-back correlated di-jets of total mass {M>Mf1M > M_f \sim 1}TeV. We show that the subsequent Hawking-decay produces multiple hard mono-jets and discuss their detection. We study the possibility of cold black hole remnant (BHR) formation of mass Mf\sim M_f and the experimental distinguishability of scenarios with BHRs and those with complete black hole decay. Due to the rather moderate luminosity in the first year of LHC running the least chance for the observation of BHs or BHRs at this early stage will be by ionizing tracks in the ALICE TPC. Finally we point out that stable BHRs would be interesting candidates for energy production by conversion of mass to Hawking radiation.Comment: 10 pages, 2 figure
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