1,339 research outputs found

    VARIABILITY OF BARBELL TRAJECTORY DURING SNATCH FOR AN ELITE YOUNG FEMALE WEIGHTLIFTER

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    The purpose of this study was to investigate the variability of the barbell trajectory for an elite young female weightlifter. One high speed camera (120Hz) was used to film the barbell trajectories of a female lifter during snatch. The subject was asked to lift different barbell mass from 65 to 80 kg (fourteen lifts in total), and thirteen successful lifts were analyzed. The barbell trajectories and movement pattern of different lifts were similar to the results of previous studies, and the barbell paths almost were overlapping for the heaviest four successful lifts. The coefficients of variation (CV) of four kinematic parameters of barbell trajectory were smaller than the results of previous studies. It can be concluded that this female weightlifter has a stable pattern of barbell trajectory under different barbell mass lifting

    BIOMECHANICS OF STOP-JUMP LANDING AND IN-LINE SKATING JUMP LANDING

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    The purpose of this study was to identify the movement characteristics of lower extremities during stop-jump landing and in-line skating jump landing. Two subjects were asked to perform three jump landing tasks: stop-jump with barefoot (BF), stop-jump with ankle constrain (AC) and jump with in-line skating boots (IS). Landing movements in sagittal plane were recorded by one high speed camera. The activation of four muscles during landing was measured by EMG system. The kinematic results showed that most variables were significantly different between the three jump landing tasks, except for knee angle at ground contact. More activated rectus femoris and smaller knee flexion acceleration found in IS have been considered to be related the ACL injury. It can be concluded that in-line skating jump landing might have higher lower limbs injury risk

    Nasal Packing after Functional Endoscopic Sinus Surgery

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    This chapter was to have a systematic review and meta‐analysis on the available literature in order to compare the efficacy and postoperative outcomes of nasal packing (absorbable vs. nonabsorbable) after treatment of chronic rhinosinusitis with functional endoscopic sinus surgery (FESS). The systematic review included five studies with 241 nasal cavities in each treatment group. The prevalence of synechia in the absorbable groups ranged from 4.6 to 8.0% while nonabsorbable groups ranged from 8.0 to 35.7%. The absorbable group had a lower postoperative bleeding; however, there were no clear findings on postoperative pain. Postoperative edema was in general similar among groups, and no consistent findings were found on bleeding and pain while removing packing. The meta‐analysis included two studies using the same type of packing material. The combined OR (0.33, 95% CI = 0.04–2.78) for postoperative synechia did not significantly favor (P = 0.016308) absorbable packing over nonabsorbable packing. The available literature showed that there is some evidence that absorbable nasal packing may provide superior outcomes to nonabsorbable packing after FESS. However, lack of homogeneity between these studies makes it impossible to have a definitive conclusion

    Effect of Surface Tension on Mass Transfer Devices

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    Discussions of Effects of Surface Tension on Water Vapor Absorbed by Triethylene Glycol Solution Films

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    The surface tension gradient can result from releasing a surfactant from the liquid film or feeding a vapor into the liquid film, and the interfacial disturbance will be induced by them. The flowing phenomena were termed “Marangoni effect,” and the mass transfer performance was enhanced by the effect. The objective of this study was to apply the Marangoni effect, such as water vapors absorbed by the liquid film of triethylene glycol (TEG) solution, and to analysze mass transfer behaviors with and without surfactants’ addition in the liquid film. The interfacial disturbance resulted from the surface tension gradient was considered in this study, and the mass transfer behaviors for packed-bed absorbers were discussed to elucidate the influence of the Marangoni effect on the absorbers. It was observed that the trends of mass transfer rates could be increased significantly as the surfactant is added into the absorption system. Experimental results showed that feeding a vapor or adding a surfactant with lower surface tension and/or higher volatility in the liquid will result in the surface tension gradient on the gas-liquid interface. The induced flowing disturbance will lead to an increment of mass transfer rate for a gas-liquid contact system

    Polarity-dependent electro-wetting or -dewetting on a conductive silicon substrate

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    We demonstrate droplet manipulation using electric signals to induce the liquid to wet or dewet on a hydrophilic conductive substrate in air without the needed for added layers. In this phenomenon, the contact angle changes more than 15{\deg} or -20{\deg} by using the ionic surfactant mediated droplets, with only 3 volts of the actuation voltage

    AGE-BSA down-regulates endothelial connexin43 gap junctions

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    <p>Abstract</p> <p>Background</p> <p>Advanced glycation end products generated in the circulation of diabetic patients were reported to affect the function of vascular wall. We examined the effects of advanced glycation end products-bovine serum albumin (AGE-BSA) on endothelial connexin43 (Cx43) expression and gap-junction communication.</p> <p>Results</p> <p>In human aortic endothelial cells (HAEC) treated with a series concentrations of AGE-BSA (0-500 μg/ml) for 24 and 48 hours, Cx43 transcript and Cx43 protein were reduced in a dose dependent manner. In addition, gap-junction communication was reduced. To clarify the mechanisms underlying the down-regulation, MAPKs pathways in HAEC were examined. Both a MEK1 inhibitor (PD98059) and a p38 MAPK inhibitor (SB203580) significantly reversed the reductions of Cx43 mRNA and protein induced by AGE-BSA. Consistently, phosphorylation of ERK and p38 MAPK was enhanced in response to exposure to AGE-BSA. However, all reversions of down-regulated Cx43 by inhibitors did not restore the functional gap-junction communication.</p> <p>Conclusions</p> <p>AGE-BSA down-regulated Cx43 expression in HAEC, mainly through reduced Cx43 transcription, and the process involved activation of ERK and p38 MAPK.</p

    A novel regulatory event-based gene set analysis method for exploring global functional changes in heterogeneous genomic data sets

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    <p>Abstract</p> <p>Background</p> <p>Analyzing gene expression data by assessing the significance of pre-defined gene sets, rather than individual genes, has become a main approach in microarray data analysis and this has promisingly derive new biological interpretations of microarray data. However, the detection power of conventional gene list or gene set-based approaches is limited on highly heterogeneous samples, such as tumors.</p> <p>Results</p> <p>We developed a novel method, the regulatory <b>e</b>vent-based <b>G</b>ene <b>S</b>et <b>A</b>nalysis (eGSA), which considers not only the consistently changed genes but also every gene regulation (event) of each sample to overcome the detection limit. In comparison with conventional methods, eGSA can detect functional changes in heterogeneous samples more precisely and robustly. Furthermore, by utilizing eGSA, we successfully revealed novel functional characteristics and potential mechanisms of very early hepatocellular carcinoma (HCC).</p> <p>Conclusion</p> <p>Our study creates a novel scheme to directly target the major cellular functional changes in heterogeneous samples. All potential regulatory routines of a functional change can be further analyzed by the regulatory event frequency. We also provide a case study on early HCCs and reveal a novel insight at the initial stage of hepatocarcinogenesis. eGSA therefore accelerates and refines the interpretation of heterogeneous genomic data sets in the absence of gene-phenotype correlations.</p
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