简介:背景:老年人肌肉蛋白质代谢出现了负平衡状态,这被认为是老年人肌肉丢失和肌肉功能衰退的重要原因。近年来的许多研究都证实,抗阻训练和蛋白质补充可以有效地改善老年人肌肉蛋白质代谢的负平衡现象,并提高老年人肌肉质量,改善其肌肉功能。目的:综述老年人抗阻训练、蛋白质补充以及抗阻训练结合蛋白质补充对老年人肌肉蛋白质代谢和肌肉功能的影响,探讨改善老年人肌肉功能和抑制肌肉丢失的可行办法。方法:应用计算机检索CNKI期刊全文数据库(2005年1月至2012年12月)和PubMed数据库(2010年1月至2012年12月)与肌肉蛋白质代谢、蛋白补充及抗阻训练对老年人肌肉蛋白质代谢影响的相关文献。检索词分别为“蛋白质代谢;肌细胞;肌肉丢失;抗阻训练;蛋白补充”和“muslcecell,resistancetraining,Sarcopenia,proteinmotablism”。结果与结论:在检索到的81篇文献中排除22篇不符合标准的文献,最终纳入59篇文献进行了分析、综述。结果表明,老年人肌肉蛋白质代谢的负平衡状态是导致老年肌肉丢失的直接原因。抗阻训练和给予富含亮氨酸的蛋白质补充能够有效增强老年人肌肉蛋白质合成代谢水平,并改善老年人肌肉功能。但老年人肌肉蛋白合成代谢对抗阻训练和蛋白补充的反应能力远低于年轻人。
简介:Inrecentyears,agreatdealofefforthasbeenmadetoacreateterahertz(THz)waveabsorberbasedonmetamaterials(MM).Metamaterialsabsorbershaveavarietyofpotentialapplicationsincludingthermalemitters,detector,stealthtechnology,phaseimaging,etc.Inthispaper,wefirstlyintroducethebasicstructureandworkprincipleoftheTHzMMabsorbers,andatransmissionlinemodelisdevelopedfordevicesanalysis.ToexpandtheapplicationofTHzabsorbers,dual-bandandbroadbandTHzMMabsorbersaredesigned,fabricated,andmeasured.Attheendofthisarticle,thefuturedevelopmenttrendsofMMabsorbersarediscussed.
简介:Anovelcompactelectromagneticbandgap(EBG)structureconstructedbyetchingtworeversesplitrings(RSRs)andinsertinginterleavingedge(IE)onthepatchofconventionalmushroom-likeEBG(CML-EBG)isinvestigated.SimulateddispersiondiagramsshowthattheproposedEBGstructurepresentsa13.6%sizereductioninthecenterfrequencyofthebandgap.TwocomparisonshavebeencarriedoutfortheanalysisoftheeffectoftheRSRsandIEconfiguration.Then,asampleofthisnovelEBGisfabricatedandtested,furtherexperimentaldataagreewellwiththesimulatedresults.Thus,thisEBGstructuremakesagoodcandidatetodecreasemutualcouplingincompactmicrostrippatcharray.
简介:录像显示器单位(VDU)的显示器图象能被收到并且分析意外电磁的噪音重建从一个个人计算机系统发出了。这个事实是在信息安全的信息漏威胁之一。因此,有效地并且快速形成PC显示以便为收到电磁的妥协辐射选择最好的频率范围,一个方法基于关联电源分析(CPA)和普通设备被建议。第一,当PC正在显示白黑色的垂直脱衣图象和黑图象时,到1GHz的10MHz的频率光谱分别地被测量大约10次。包含显示信息的频率范围能通过CPA被获得。然后,特殊图象信号在点频率和泛音附近被寻找。如果当显示全部的黑图象时,特殊信号消失,是真实特殊信号能被判定。最后,最好的收到频率范围能被全面考虑选CPA和信号的结果到特殊图象信号的噪音比率(SNR)。为了检查选择频率的有效性,变化,偷听实验被执行。结果证明选择频率范围能比另外的频率乐队检索高质量的图象。
简介:Akindofdual-band-stopfilterwithanunsymmetricalT-shapedefectedgroundstructure(DGS)isproposed.Thefilterhastwobandgapcentersat4.9GHzand7.35GHz,respectively,wherethetwocentrefrequenciesarejustthesecondandthirdharmonics2.45GHz.Thefilterswithhighband-stopperformanceandwidebandspurioussuppressioncanbeachievedbycascadingminiaturizedunsymmetricalT-shapeDGS.Theattenuationofthree-cascadedT-shapeDGSfilteris30.77dBat4.9GHzand17.96dBat7.35GHzrespectively.Theaboveexperimentalresultsareingoodagreementwiththesimulationresults,especiallyforthethirdharmonic.
简介:摘要目的探讨等长抗阻力性肌力训练防治颈型颈椎病的作用;方法将92例患者随机分为对照组及康复组各46例,对照组应用常规推拿,康复组加用等长抗阻力性肌力训练;结果康复组不仅痊愈率和总有效率都高于对照组(P<005)而且总治疗次数、半年复发率及一年复发率都明显低于对照组(P<005);结论等长抗阻力性肌力训练不仅对治疗而且对预防颈型颈椎病都有明显的效果,值得进一步临床研究并广泛推广。
简介:Higher-bandself-trappingandoscillation(rotation)ofnonlinearquadruplebeamsintwo-dimensional(2D)squarephotoniclatticesarenumericallydemonstrated.Underappropriateconditionsofnonlinearity,aquadruple-likebeamcanself-trapintolocalizedmodesthatresideinthesecondBraggreflectiongapthroughsingle-siteexcitation.Bychangingtheinitialorientationoftheincidentquadruplebeamrelatedtothelattices,periodicoscillationsofthelocalizedquadruplemodemaybeobtained.Thelocalizedquadruplestatebecomesarotatingdoublychargedopticalvortex(DCV)duringrotationandshouldundergocharge-flippingwhentherotatingdirectionisreversed.
简介:Inrecentyears,microstripantennashavebeenmorewidelyappliedinsatellitecommunications,mobilephones,unmannedaerialvehicle(UAV),andweapons.Amicro-electro-mechanicalsystems-based(MEMS-based)high-resistancesiliconC-bandmicrostripantennaarrayhasbeendesignedfortheintelligentammunition.Thecenterfrequencyis4.5GHz.Acavityhasbeendesignedinsubstratetoreducethedielectricconstantofsiliconandhigh-resistancesiliconhasbeenusedasthematerialofsubstratetoimprovethegainofantenna.ItisveryeasytobemanufacturedbyusingMEMStechnologybecauseoftheimprovedstructureoftheantenna.Theresultsshowthatthegainoftheantennais8dBandvoltagestandingwaveratio(VSWR)islessthan2bytheanalysisandsimulationinhighfrequencystructuresimulator(HFSS).
简介:Atunablenegativecoefficientband-passmicrowavephotonicfilter(MPF)withimprovedmainlobe-to-sidelobesup-pressionratio(MSSR)byaSagnacinterferometer(SI)isexperimentallydemonstrated.ThenegativecoefficientcharacteristicofMPFisachievedbyusingthephasemodulationtechnology.Thecentralfrequencyoftheband-passMPFistunablecontinuouslybychangingthewavelengthseparationofmulti-wavelengthopticalcarriers.A38-tapnegativecoefficientband-passMPFwhoseMSSRisincreasedbyabout6.371dBisachievedinexperimentbyapodizingthetapcoefficientwiththeSagnacinterferometer.