简介:AbstractChronic hepatitis B virus (HBV) infection due to vertical transmission remains a critical concern with regards to eliminating HBV infection. Implementation of hepatitis B vaccine, the foundation to prevent perinatal and horizontal transmission, has reduced the prevalence of HBV by >80%. In countries where the hepatitis B immune globulin (HBIG) is available, such as China and the United States, the administration of HBIG and hepatitis B vaccine to the infants of mothers who are positive for hepatitis B surface antigen has become a standard practice and is effective in preventing vertical transmission. Accumulating evidence on the efficacy and safety of antiviral prophylaxis during pregnancy indicates the probability of attaining the goal of the World Health Organization to eliminate hepatitis by 2030. In this review, we discuss the transmission routes, diagnostic criteria, and preventive strategies for vertical transmission. A preventive program that includes screening before pregnancy, antiviral prophylaxis during pregnancy, and postpartum immunoprophylaxis provides "perfect strategies" to eliminate vertical transmission. However, there is still a notable gap between "perfect strategies" and real-world application, including insufficient coverage of timely birth dose vaccine and the efficacy and necessity of HBIG, especially in mothers who are negative for hepatitis B envelope antigen. In particular, there is a clear need for a comprehensive long-term safety profile of antiviral prophylaxis. Therefore, feasible and cost-effective preventive strategies need to be determined across regions. Access also needs to be scaled up to meet the demands for prophylaxis and prevalence targets.
简介:这研究被执行在不肥沃的汉中国家庭从父亲分析YqAZFcmicrodeletions的垂直传播到儿子调查基因因素和家庭背景影响富饶地位。在19个汉家庭的不肥沃的男性的外部血与修改复合聚合酶链反应(PCR)被提取并且屏蔽。家谱根据富饶地位和这些题目的临床的特征被拉。YqAZFcmicrodeletions的垂直传播在19个调查家庭的六种情况中被检测(31.6%,6/19)。尽管父亲和儿子显示出YqAZFc删除的一种类似的类型,父亲是肥沃的,而儿子是不肥沃、显示出的严重oligozoospermia。到在代上的不肥沃的儿子的从肥沃的父亲的YqAZFcmicrodeletion的垂直传播不是稀罕的。这在汉中国家庭在父亲和儿子在富饶地位上有不同效果。基因因素和家庭背景影响spermatogenetic显型。
简介:Withthedevelopmentofhigh-resolutionandmulti-scaleunifiednumericalmodel,someoftechniquesaboutnon-hydrostaticmeso-scalenumericalweatherpredictionareaddressed.Theimpactoftheverticalcoordinatesystemisoneofthem.Inthispaper,basedonaWRF(WeatherResearchandForecast)model,theimpactonthecalculationofverticalvelocitywasstudiedwithdifferentverticalcoordinates.Thesimulationresultsshowedthatthecalculationofverticalvelocityissensitivetoverticalcoordinates.Itisespeciallymoreevidentwhentheresolutionincreased.Duetothecloserelationshipsbetweenverticalvelocityandprecipitation,thedifferenceofverticalvelocityinevitablyinfluencesmodel'sdescriptionofprecipitation.Anidealexperimentexhibitsthatpressuregradientforcecomputationsinthepressureterrain-followingcoordinatearesensitivetosurfacepressure.
简介:Densitystratifiedflowwithboththeverticaltemperaturegradientandtheverti-calsalinitygradientissimulatednumerically,inwhichturbulenttermsarecalculatedbyasim-plifiedturbulencestress/fluxalgebraicmodel.Thefeatureofstratificationandturbulenceisde-scribedcorrectlybythemodel.Thecomputationalresultsagreewellwiththeexperimentaldata.However,thek-eturbulencemodelisnotsosuccessful.
简介:Thepresentworkprovidesanovelmethodforcalculatingverticalvelocitybasedoncontinuityequationsinapressurecoordinatesystem.Themethodovercomesthedisadvantageofaccumulationofcalculatingerrorsofhorizontaldivergenceincurrentkinematicsmethodsduringtheintegrationforcalculatingverticalvelocity,andconsequentlyavoidsitssubsequentcorrection.Inaddition,throughmodificationsofthecontinuityequations,itshowsthatthevorticityoftheverticalshearvector(VVSV)isproportionalto-ω,theverticalvelocityinpcoordinates.Furthermore,ifthechangeofωinthehorizontaldirectionisneglected,thevorticityofthehorizontalvorticityvectorisproportionalto-ω.Whenωisunderafluctuatingstateintheverticaldirection,theupdraftoccurswhenthevectorofhorizontalvorticityrotatescounterclockwise;thedowndraftoccurswhenrotatingclockwise.ThevalidationresultindicatesthatthepresentmethodisgenerallybetterthantheverticalvelocitycalculatedbytheωequationusingthewetQ-vectordivergenceasaforcingterm,andtheverticalvelocitycalculatedbyutilizingthekinematicsmethodisfollowedbytheO’Brienmethodforcorrection.Theplus-minussignoftheverticalvelocityobtainedwiththismethodisnotcorrelatedwiththeintensityofdBZ,buttheabsoluteerrorincreaseswhendBZis>=40.Thismethoddemonstratesthatitisagoodreflectionofthedirectionoftheverticalvelocity.
简介:Inthispaper,theprincipleofmirrorimageisusedtotransformtheproblemofwavediffractionfromacircularcylinderinfrontoforthogonalverticalwallsintotheproblemofdiffractionoffoursymmetricincidentwavesfromfoursymmetricallyarrangedcircularcylinders,andthentheeigenfunctionexpansionofvelocitypotentialandGrafsadditiontheoremareusedtogivetheanalyticalsolutiontothewavediffractionproblem.Therelationofthetotalwaveforceoncylindertothedistancebetweenthecylinderandorthogonalverticalwallsandtheincidenceangleofwaveisalsostudiedbynumericalcomputation.
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简介:Regularandirregularwaveforcesactingonverticalwallsarestudiedbyapreviouslydevelopednumericalmodel.Thecomputedwaveforcesarecomparedwiththeavailableexperimentaldatatoverifythenumericalmodel,andsatisfactoryagreementsareobtained.Thevariationofwaveforceswithincidentanglesandtheshapeofsimultaneouspressuredistributionareinvestigated,andthecomparisonsbetweennumericalresultsandGoda'spredictionsarealsocarriedout.Itisconcludedthatthemaximumwaveforcesactingontheunitlengthofverticalwallisofteninducedbytheobliquelyincidentwavesinsteadofnormallyincidentwaves,whileGoda'sformulamaybeinapplicableforobliquewaveincidence.Theshapeofsimultaneouspressuredistributionisnotsignificantlyinfluencedbyincidentangles,anditcanbefavorablypredictedbyGoda'sformula.WhenregularwaveheightsaretakenasthesameasirregularwaveheightH1%,theirregularwaveforcesPh,1%areslightlylargerthanregularwaveforcesinmostcases.
简介:Basedonthe2ndordercnoidalwavetheory,thecharactersofshallowwaterstandingwavesandtheiractiononverticalwallsarestudiedinthispaper.Thetheoreticalexpressionsofthewavesurfaceelevationinfrontofandthewavepressureontheverticalwallareobtained.Inordertoverifythetheoreticalresults,modeltestsweremadeintheStateKeyLaboratoryofCoastalandOffshoreEngineeringatDUT.Forthewavesurfaceelevationinfrontofthewallandthewaveforcesonthewallatthemomentwhenthewavesurfaceatthewallsurfacegoesdowntothebottomofthewavetrough,thecalculatedresultscoincidequitewellwiththeexperimentalresults.Forthewaveforcesonthewallatthemomentwhenthewavesurfaceatthewallsurfacegoesuptothetopofthewavecrest,thetheoreticalexpressionsaremodifiedbytheexperimentalresults.Fortheconvenienceofpracticaluse,calculationsaremadeforthewaveconditionswhichusuallyoccurinengineringpracticebyuseoftheinves
简介:Likevaluechainandsupplychain,“industrialchain”becomesthefocusofattention.Theimplicationof“industrialchain”hasgainedalargerangeofextension.Itnotonlyexpressestheindustrial“chain”structureandrelationshipof“backandforward”inorderor“upanddown”indirection,butalsoitrepresentsaclusteroflargescaleoffirmsinanareaorcolony.Itisanetwork,oracommunity.Consequently,weconcludethat“industrialchain”isasynthesisofindustrialchain,industrialcluster,orindustrialnetwork.Inthisarticle,firstlywewilldistinguishindustrychainfromindustry.Anindustryisthecollectionoffirmsthathavethesameattribute,soanindustrycanbedefinedbyfirmcollectionofcertainattribute.Weindicatethatindustrialchainisakindofverticalandorderlyindustriallink.Itisdefinedaccordingtoaseriesofspecificproductorservicecreated.Secondlyweanalyzetheverticalorderlydefiinitionprocessfromtheaspectsofsocialdivisionoflaborandrequirementdivision,self-organizationsystem,andvalueanalysis.Non-symmetryanddependingonsystemorcommunityoflargescaleofindustrialunitsleadtoentireindustryto“orderly”structure.Ontheotherhand,thedraughtofdiversityandcomplexityofrequirementsimultaneouslyleadtoentireindustrytobemore“orderly”.Alongwithprocessesofself-organization,industrialwillappi'oachthestateofmoreorderlyandsteady,andconstantlymakeindustrialchainupgrade.Eachfirmorunit,whowillgainthevalue,hastoestablishchannelsofvalue,whichwecalled“industrialvaluechain”.Lastly,wediscusstheconsequenceofverticalandorderlydefinition,whichisexhibitedbyacertainrelationshipbody.Thetypicalformsofindustrialchainincludeindustrialcluster,strategyallianceandverticalintegrationetc.
简介:在那里存在,这被证明了在垂直的热之间的生气联合由使用线性热力学的狂暴的运输和垂直速度。这结果断言热的垂直部件狂暴的运输流动由垂直潜在的温度梯度的运输和垂直速度的联合运输组成。在这篇论文,垂直的热上的垂直速度的联合效果狂暴的交通被从大气的边界层使用观察数据决定联合系数的十字验证,并且狂暴的交通的一系列重要性质外面被打开。这些性质显示生气联合系数是尺寸的对数功能不太垂直的速度和尺寸更少高度,并且不仅与磨擦速度u*,有关而且到联合粗糙高度zW0和联合温度T垂直速度的W0。另外,仅仅当垂直速度大小遵循限制|W/u*时,功能关系建议那|≠1,并且在水平z然后,垂直速度导致生气联合的W0,垂直的热上的效果狂暴的运输流动。生气联合理论和试验性的结果提供挑战给传统的狂暴的K闭合理论和Monin-Obukhov类似理论。
简介:Discussionsarecarriedoutontheverticaldiscretizationofcurrentatmosphericmodels.Itispointedoutthatthereexistproblemsintheintegrationofthehydrostaticequationandthecomputationofverticaladvection,verticaldiffusionandsoon.Thensomepossiblewaysforsolvingoralleviatingthemaresuggested.Finally,thechoiceofverticalcoordinateandbasisfunctionsisdiscussed.
简介:Magneticforcetransmissionofareciprocatingmotionisstudiedbytheoreticalanalysisandexperiment.Amathematicalmodelforcalculatingthemagneticforceisderivedusingthetheoryofequivalentmagneticcharges.Anexperimentalrigisconstructedtotestthetransmissionandthemodelisverifiedbyexperiment.Effectofthetransmissionparametersonthemagneticforceisanalyzedtheoreticallyfromthemodel,andcharacteristicofthetransmissionisstudiedexperimentally.Sincethetransmissioniswithoutdirectcontactbetweentwoelements,itissuitableforapplicationinanorganism.
简介:AbstractTransmission network analysis is a crucial evaluation tool aiming to explore the characteristics of the human immunodeficiency virus epidemic, develop evidence-based prevention strategies, and contribute to various areas of human immunodeficiency virus/acquired immunodeficiency syndrome prevention and control. Over recent decades, transmission networks have made tremendous strides in terms of modes, methods, applications, and various other aspects. Transmission network methods, including social, sexual, and molecular transmission networks, have played a pivotal role. Each transmission network research method has its advantages, as well as its limitations. In this study, we established a systematic review of these aforementioned transmission networks with respect to their definitions, applications, limitations, recent progress, and synthetic applications.
简介:Toanalyzetheinfluenceof±400kVQinghai-TibetHVDCtransmissionsystemontransmissionlineprotectionsinQinghaiACpowersystem,aclosed-loopsimulationsystemwasconstructedbycombingHyperSimsystemwithHVDCcontrolprotectiondevices.Variousfaultsondouble-circuit750kVandmulticircuit330kVACtransmissionlinesinQinghaipowersystemweresimulated.TheimpedancecharacteristicsandharmoniccomponentsatQinghaisideofQing-TibetDCtransmissionlinewereanalyzed.TheharmonicproportioninvoltagesandcurrentswerestudiedforfaultsthattookplaceatdifferentlocationsneartheDCsystem.TheinflenceofQing-TibetDCsystemonthedirectionalcomponentsofprotections,differentialprotectionsanddistanceprotectionsofACtransmissionlineswasdiscussedanddrewtheconclusionsthattheDCsytemhadlittleinfluenceondifferentialprotections,whilehadgreatinflenceondirectionalcomponentsanddistanceprotection.TheconclusionscanprovidereferenceforstudyingtheinteractionbetweenACandDCsystems.