1,265 research outputs found

    BIOMECHANICAL ANALYSIS OF BACK HANDSPRING TO BACKWARD SALTO WITH TRIPLE TWIST IN GYMNASTIC FLOOR EXERCISE

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    INTRODUCTION: The degree of difficulty in gymnastic movements has increased dramatically during the last 30 years, a fact is which is unimaginable to those not skilled in the art. For the gymnast, practice of a new movement is one of the most important ways to learn a new skill. The discipline of Sports Biomechanics can provide the knowledge to increase the efficiency of learning. The purpose of this study was to provide biomechanical analysis of their technique in order to identify specific characteristics and problem areas so that the skill can be mastered in as short a time as possible

    A versatile route to fabricate single atom catalysts with high chemoselectivity

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    Preparation of single atom catalysts (SACs) is of broad interest to materials scientists and chemists but remains a formidable challenge. Herein, we develop an efficient approach to synthesize SACs via a precursor-dilution strategy, in which metalloporphyrin (MTPP) with target metals are co-polymerized with diluents (tetraphenylporphyrin, TPP), followed by pyrolysis to N-doped porous carbon supported SACs (M1/N-C). Twenty-four different SACs, including noble metals and non-noble metals, are successfully prepared. In addition, the synthesis of a series of catalysts with different surface atom densities, bi-metallic sites, and metal aggregation states are achieved. This approach shows remarkable adjustability and generality, providing sufficient freedom to design catalysts at atomic-scale and explore the unique catalytic properties of SACs. As an example, we show that the prepared Pt1/N-C exhibits superior chemoselectivity and regioselectivity in hydrogenation. It only converts terminal alkynes to alkenes while keeping other reducible functional groups such as alkenyl, nitro group, and even internal alkyne intact

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    <p>Cell scratch test and Transwell were used to measure the migration abilities of HSVSMCs. NC = Negative control group, only control siRNA transfected; GAS5(-) = lncRNA-GAS5 knockdown group transfected with silence siRNA. <b>A:</b>Cell scratch test was used to measure the migration abilities of HSVSMCs. The results showed that the HSVSMCs have the best migration abilities in the first 24 hours. Values are mean±SE, N = 4. <b>B:</b> The migration abilities of HSVSMCs measured by Transwell. After transfected by lncRNA-GAS5 siRNA for 48 hours, the HSVSMCs were passage into the Transwell Inserts. Then 4 hours, 7 hours, 10 hours later, the migration HSVSMCs were photographed and counted, respectively. Knockdown of lncRNA-GAS5 expression promotes migration of HSVSMCs. Optical microscope images under 200x magnification. <b>C:</b> The migration abilities of HSVSMCs were reflected indirectly by the new migration cells counting with Transwell. Silencing of lncRNA-GAS5 expression increses migration ability of HSVSMCs. Values are mean±SE, N = 10; *, P<0.05.</p

    Transcription Profiling of a Revealed the Potential Molecular Mechanism of Governor Vessel Electroacupuncture for Spinal Cord Injury in Rats

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    Objective This study aimed to identify differentially expressed genes (DEGs) by transcriptome analysis to elucidate a potential mechanism by which governor vessel electroacupuncture (GV-EA) promotes neuronal survival, axonal regeneration, and functional recovery after complete transection spinal cord injury (SCI). Methods Sham, control, or GV-EA group adult female Sprague Dawley rats underwent a complete transection SCI protocol. SCI area RNA-seq investigated the DEGs of coding and noncoding RNAs 7 days post-SCI. Gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) enrichment analyses were used to classify DEGs functions, to explain a possible molecular mechanism. Immunofluorescence and BBB (Basso, Beattie, and Bresnahan) score were used to verify a GV-EA treatment effect following SCI. Results GV-EA treatment could regulate the expression of 173 mRNA, 260 lncRNA, and 153 circRNA genes among these DEGs resulted by SCI. GO enrichment analysis showed that the DEGs were most enriched in membrane, actin binding, and regulation of Toll-like receptor signaling pathway. KEGG pathway analysis showed enriched pathways (e.g. , Toll-like receptors, MAPK, Hippo signaling). According to the ceRNA network, miR-144-3p played a regulatory role by interacting with lncRNA and circRNA. GV-EA also promoted the injured spinal cord neuron survival, axonal regeneration, and functional improvement of hind limb locomotion. Conclusion Results of our RNA-seq suggest that post-SCI GV-EA may regulate characteristic changes in transcriptome gene expression, potential critical genes, and signaling pathways, providing clear directions for further investigation into the mechanism of GV-EA in subacute SCI treatment. Moreover, we found that GV-EA promotes neuronal survival, nerve fiber extension, and motor function recovery in subacute SCI

    Active Surveillance of Carbapenemase-Producing Organisms (CPO) Colonization With Xpert Carba-R Assay Plus Positive Patient Isolation Proves to Be Effective in CPO Containment

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    Background: Rapid screening of patients for colonization with carbapenemase-producing organisms (CPO), coupled with implementation of infection prevention strategies, has the potential to contain the spread of CPO.Methods: We first evaluated the performance of Xpert Carba-R assay (in comparison with other phenotypic methods) for carbapenemase detection using clinical isolates, and then used it to determine the intestinal CPO colonization in hospitalized patients. We then assessed the effectiveness of patient isolation in controlling the spread of CPO in a medical intensive care unit.Results: The Xpert Carba-R assay required the least processing time to reveal results and showed a 94.5% sensitivity and specificity in carbapenemase detection, except for IMP-8 (n = 4). During a 6-month study period, 134 patients in one ward were studied for CPO colonization and infection. Fifteen patients (11.2%) were colonized by CPO as detected by Xpert Carba-R assay, including three NDM, three IMP, and nine KPC possessing strains. The overall colonization and CPO infection rates were both 11.2% each. Isolation of patients with CPO led to a reduction in both colonization (from 28.6 to 5.6%) and infection rates (from 35.7 to 2.8%) during the study period (p &lt; 0.05).Conclusion: Active surveillance of CPO utilizing the Xpert Carba-R assay supplemented with immediate patient isolation, proved to be an effective strategy to limit the spread of CPO in a health care setting

    Impacts of Hypoxia-Inducible Factor-1 Knockout in the Retinal Pigment Epithelium on Choroidal Neovascularization

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    PURPOSE. Hypoxia-inducible factor (HIF)-1 is a key oxygen sensor and is believed to play an important role in neovascularization (NV). The purpose of this study is to determine the role of retinal pigment epithelium (RPE)-derived HIF-1a on ocular NV. METHODS. Conditional HIF-1a knockout (KO) mice were generated by crossing transgenic mice expressing Cre in the RPE with HIF-1a floxed mice, confirmed by immunohistochemistry, Western blot analysis, and fundus fluorescein angiography. The mice were used for the oxygen-induced retinopathy (OIR) and laser-induced choroidal neovascularization (CNV) models. RESULTS. HIF-1a levels were significantly decreased in the RPE layer of ocular sections and in primary RPE cells from the HIF1a KO mice. Under normal conditions, the HIF-1a KO mice exhibited no apparent abnormalities in retinal histology or visual function as shown by light microscopy and electroretinogram recording, respectively. The HIF-1a KO mice with OIR showed no significant difference from the wild-type (WT) mice in retinal levels of HIF-1a and VEGF as well as in the number of preretinal neovascular cells. In the laser-induced CNV model, however, the disruption of HIF-1a in the RPE attenuated the over expression of VEGF and the intercellular adhesion molecule 1 (ICAM-1), and reduced vascular leakage and CNV area. CONCLUSIONS. RPE-derived HIF-1a plays a key role in CNV, but not in ischemia-induced retinal NV. (Invest Ophthalmol Vis Sci

    Mesenchymal Stem Cells Combined With Electroacupuncture Treatment Regulate the Subpopulation of Macrophages and Astrocytes to Facilitate Axonal Regeneration in Transected Spinal Cord

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    Objective Herein, we investigated whether mesenchymal stem cells (MSCs) transplantation combined with electroacupuncture (EA) treatment could decrease the proportion of proinflammatory microglia/macrophages and neurotoxic A1 reactive astrocytes and inhibit glial scar formation to enhance axonal regeneration after spinal cord injury (SCI). Methods Adult rats were divided into 5 groups after complete transection of the spinal cord at the T10 level: a control group, a nonacupoint EA (NA-EA) group, an EA group, an MSC group, and an MSCs+EA group. Immunofluorescence labeling, quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blots were performed. Results The results showed that MSCs+EA treatment reduced the proportion of proinflammatory M1 subtype microglia/macrophages, but increased the differentiation of anti-inflammatory M2 phenotype cells, thereby suppressing the mRNA and protein expression of proinflammatory cytokines (tumor necrosis factor-α and IL-1β) and increasing the expression of an anti-inflammatory cytokine (interleukin [IL]-10) on days 7 and 14 after SCI. The changes in expression correlated with the attenuated neurotoxic A1 reactive astrocytes and glial scar, which in turn facilitated the axonal regeneration of the injured spinal cord. In vitro, the proinflammatory cytokines increased the level of proliferation of astrocytes and increased the expression levels of C3, glial fibrillary acidic protein, and chondroitin sulfate proteoglycan. These effects were blocked by administering inhibitors of ErbB1 and signal transducer and activator of transcription 3 (STAT3) (AG1478 and AG490) and IL-10. Conclusion These findings showed that MSCs+EA treatment synergistically regulated the microglia/macrophage subpopulation to reduce inflammation, the formation of neurotoxic A1 astrocytes, and glial scars. This was achieved by downregulating the ErbB1-STAT3 signal pathway, thereby providing a favorable microenvironment conducive to axonal regeneration after SCI

    Cytochrome P450 3A Enzymes Are Key Contributors for Hepatic Metabolism of Bufotalin, a Natural Constitute in Chinese Medicine Chansu

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    Bufotalin (BFT), one of the naturally occurring bufodienolides, has multiple pharmacological and toxicological effects including antitumor activity and cardiotoxicity. This study aimed to character the metabolic pathway(s) of BFT and to identify the key drug metabolizing enzyme(s) responsible for hepatic metabolism of BFT in human, as well as to explore the related molecular mechanism of enzymatic selectivity. The major metabolite of BFT in human liver microsomes (HLMs) was fully identified as 5β-hydroxylbufotalin by LC-MS/MS and NMR techniques. Reaction phenotyping and chemical inhibition assays showed that CYP3A4 and CYP3A5 were key enzymes responsible for BFT 5β-hydroxylation. Kinetic analyses demonstrated that BFT 5β-hydroxylation in both HLMs and human CYP3A4 followed the biphasic kinetics, while BFT 5β-hydroxylation in CYP3A5 followed substrate inhibition kinetics. Furthermore, molecular docking simulations showed that BFT could bind on two different ligand-binding sites on both CYP3A4 and CYP3A5, which partially explained the different kinetic behaviors of BFT in CYP3A4 and CYP3A5. These findings are very helpful for elucidating the phase I metabolism of BFT in human and for deeper understanding the key interactions between CYP3A enzymes and bufadienolides, as well as for the development of bufadienolide-type drugs with improved pharmacokinetic and safety profiles
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