简介:摘要下腰疼痛正在成为目前影响人们生活质量的重要因素,其发病的年龄越来越趋于年轻化,每年因下腰痛带来的社会经济损失巨大。椎间盘退变(intervertebral disc degeneration,IDD)是引起下腰疼的重要原因,在多重因素作用下,椎间盘组织出现生物力学和结构的变化,发生纤维环破裂、髓核组织突出,使脊髓和神经根受压,从而引起患者出现下腰疼。微小RNA(Micro-RNA,miRNA)是一类长度为18~24个核苷酸序列的单链非编码小分子RNA,其在真核生物中广泛存在,作为基因表达的重要调控分子之一,已被证明在许多种疾病起始及进展阶段发挥着关键作用,故认为其可能在椎间盘退变中也发挥着重要的作用。目前,临床上针对IDD的治疗手段主要以手术治疗缓解临床症状为主,即使当前手术治疗可以取得良好的疗效,但是手术治疗会给患者带来更大的身体创伤和经济负担。miRNA在椎间盘退变过程中的作用是当前学术界研究的热点之一,研究表明miRNA在退变的椎间盘组织中呈现异常的表达模式,参与IDD的多种病理过程。目前,一些miRNA已被证明与椎间盘退变过程中的多种病理过程有关,包括髓核细胞凋亡和增殖、细胞外基质的降解、细胞自噬、炎症反应及软骨终板的退变等。基因芯片对比研究显示一些miRNA在退变髓核细胞中的表达与正常髓核细胞存在明显差异,这些差异表达的miRNA通过调控其各自的上、下游通路可能参与髓核细胞退变的进程,调控通路多有交叉并行,构建出一个庞大的miRNA调控网。了解miRNA在发病过程中的靶基因和机制,能够在疾病的起源、发展和预后等方面提供重要参考。因此,综述了miRNA在椎间盘退变过程中的重要作用和潜在的临床治疗意义。随着对miRNA研究的深入,通过了解椎间盘退变的分子生物学机制,可以为IDD的诊断和治疗提供新思路,非常有可能成为IDD生物学治疗的新策略。
简介:Basedonthegivenreactionconditionandmedium,thegrowthofmicro-andnanocrystalscanbedividedintofourtypes,growthinsolutionatnormalpressure,hydrothermalgrowth,solvothermalgrowth,andmolten-saltgrowth.Whenthewaterororganicsolventasthereactionmedium,surfactant,suchassodiumdodecylbenzenesulfonate,canbeaddedtoregulatethe
简介:ThePhilippinedepartmentofEnergy(DOE)hassignedamemorandumofagreementwiththeJapanesegovernmentforaP33.SM(US$0.67M)demonstrationproject.The65kWmicrohydropowersystemwillbenefitabout200householdsinLeyte.
简介:AIM:ToscreenmicroRNAs(miRNAs)andsetuptargetmiRNAsinpterygium.METHODS:PrimaryfibroblastswereisolatedfrompterygiumandTenon’scapsuleandcultured.ImmunocytochemicalanalysisandWesternblottingwereperformedtoconfirmthecultureoffibroblasts.Inall,1733miRNAswerescreenedinthefirststepbyusingGeneChip?miRNA3.0Array.SpecificmiRNAsinvolvedinthepathogenesisofpterygiumweresubsequentlydeterminedusingthefollowingcriteria:1)highreproducibilityinarepetitivetest;2)baselogvalueof>7.0forbothcontrolandpterygialfibroblasts;and3)logratioof>1.0betweenpterygialfibroblastsandcontrolfibroblasts.RESULTS:Primaryscreeningshowedthat887/1733miRNAswereup-regulatedand846/1733miRNAsweredown-regulatedinpterygialfibroblastscomparedwiththoseincontrolfibroblasts.Ofthe1733miRNAsscreened,4miRNAs,namely,miRNA-143a-3p,miRNA-181a-2-3p,miRNA-377-5pandmiRNA-411a-5p,mettheabove-mentionedcriteria.Primaryscreeningshowedthatthese4miRNAswereup-regulatedinpterygialfibroblastscomparedwithcontrolfibroblastsandthatmiRNA-143a-3phadthehighestmeanratiocomparedwiththemiRNAsincontrolfibroblasts.CONCLUSION:miRNA-143a-3p,miRNA-181a-2-3p,miRNA-377-5pandmiRNA-411a-5pareup-regulatedinpterygialfibroblastscomparedwithcontrolfibroblasts,suggestingtheirinvolvementinthepathogenesisofpterygium.
简介:ThispaperisfocusedonthemodelidentificationofaMicroAirVehicle(MAV)instraightsteadyflightcondition.Theidentificationisbasedoninput-outputdatacollectedfromflighttestsusingbothfrequencyandtimedomaintechniques.Thevehicleisanin-house40cmwingspanairplane.Becauseofthecomplexcoupled,multivariableandnonlineardynamicsoftheaircraft,linearSISOstructuresforboththelateralandlongitudinalmodelsaroundareferencestatewerederived.TheaimoftheidentificationistoprovidemodelsthatcanbeusedinfuturedevelopmentofcontroltechniquesfortheMAV.
简介:Effectofvelocityjumpandtemperaturejumpontheheatandmomentumtransferinmicro-domainsisdiscussedindetail.Asimulationaidedbylocallyfullydevelopedassumptionisdevelopedtoexplaintheexperimentalresultsdifferentfromthosepredictedbyconventionaltheory.Heattransferinmicro-channelsundertheuniformheatfluxisalsoanalyzed.Itisfoundthatvelocity-jumpandtemperature-jumphaveanoppositeinfluenceandNusseltnumberhasagreatervaluewhentheKnudsennumberisverysmall,WiththeincreasingofKnudsenNumber,Nussqltnumberbecamesmallerthan8.24.
简介:李德美V:这种消息不是第一次出现了。英国mayfaire早些年不就是这样?所以前几天电台采访关于葡萄酒投资,忘了提到这点了,还有“人为的风险”。
简介:Fivekindsof45#steelsampleswithconcavefeaturesonthesurfaceweremanufacturedusingLaserTexturingTechnology(LTT).Optimumdesigntheorywasusedtodesigntheexperiment,andatwo-levelorthogonaltable-L16(215)designwasadopted.Micro-wearandmicro-frictionexperiencedbysampleswithconcavesurfacefeaturesandsampleswithsmoothsurfaceswerecomparedexperimentally.Thewearresistanceofsampleswithconcavesurfacefeatureswasincreasedmost,anddifferentsurfacemorphologieshaddifferenteffectsonfrictionandwearproperties.