简介：进入2004年后，腾讯一直在不遗余力地为QQ注入新的活力，经过几个月的QQ预览版后，腾讯QQ终于推出了功能更为强大的QQ2004Beta版，你可不要小看这个Beta版，它所包含的内容可一点不弱呦！

简介：INTRODUCTIONPolyhydroxybutyrate(PHB)andit'scopolymerPHBVachievedbythebiosyntheticpathway,hasattractedmuchattentionasanalternationbiodegradablematerials.Theyhavetheexcellentbiocompatibilityandproperdegradationperiodsbyoptimizationofpertinentmolecularweightandcopolymercompositions.

简介：1.IntrodnctionThispaperextendsthestudyofthesingularmatrixvariatebetadistributionofrank1[1]tothecaseofageneralrank.Astherelateddistributiontonormalsampling,thematrixvariatebetadistribution(alsocalledthemultivariatebetadistribution)hasbeenstudiedextens...

简介：Aprobabilitydensityfunction(PDF)isderivedofbetadistributionwithbothλ3(skewness)andλ4(kurtosis)asparametersforweaklynonlinearwavesurfaceelevationbyuseofamethodrecentlyproposedbySrokosz.ThisPDFnotonlyhasasimplerformthanthewell-knownGram-CharlierSeriesPDFderivedbyLonguet-Higgins,butalsoovercomesanobviousshortcomingofthelatterthatwhentheseriesisunsuitablytruncated,theresultingPDFislocallynegative.TotestthederivedbetaPDF,laboratorialexperimentsofwindwavesareconducted.TheexperimentaldataindicatethatthetheoreticalrequirementsoftheparametersinthebetaPDFarefulfilled.TheexperimentalresultsshowthatthepresentPDFisinbetteragreementwiththemeasureddatathanthebetaPDFonlyincludingparameterλ3,andalsothantheGram-CharlierSeriesPDFtruncateduptothetermofH6.

简介：对于MMO这种类型的游戏来说，发行前能否获得玩家群体的支持（communitysupport）对于游戏上市后能否取得成功有着至关重要的影响。要想让你的游戏成为大家茶余饭后的焦点，一个最好的办法就是让游戏玩家群中经验丰富的成员参加到游戏的早期测试中。话虽如此，但在实际操作中，还是需要谨慎地把握好尺度。

简介：Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/Organophilicmontmorillonite(PHBV/OMMT)nanocompositeswerepreparedandthebiodegradabilityofthePHBV/OMMTnanocompositeswasstudiedbyacultivationdegradingmethodinsoilsuspension.TherelationshipbetweenstructureandbiodegradabilityofPHBV/OMMTnanocompositeswasinvestigated.TheresultsshowedthatthebiodegradabilityofPHBV/OMMTnanocompositesdecreasedwithincreasingamountofOMMTanditwasrelatedtothenumberofPHBVdegradingmicroorganismsindegradationenvironment,theanti-microbialpropertyofOMMTandthedegreeofcrystallinityofthenanocomposites.

简介：ObjectivesToinvestigatetheeffectsoftestosteroneenanthate(TE)onserumlipidsandlipoproteinsmetabolismandtheexpressionofandrogenreceptor(AR),estrogenreceptorbeta(ER-β)andplateletderivedgrowthfactorbeta(PDGFR-β)inaorticvascularsmoothmuscletissues(VSMTs).MethodsFortyagedmaleratswererandomlydividedinto4groups,groupA(placebogroup),groupB(2.5mg/kgintramuscularinjectionofTEonceaweek),groupC(5.0mg/kgintramuscularinjectionofTEonceaweek),groupD(10.0mg,/kgintramuscularinjectionofTEonceaweek).Allanimalswerefedfreelyduring16-weektreatmentperiods.TheexpressionofAR,ER-βandPDGFR-βwerestudiedbyWesternbolt.ResultsAverageserumLDL-CwasloweringroupDthanthatingroupA(p＜0.01).Comparedwiththeothergroups,averageserumTCwasalsoloweringroupD(p＜0.05).ARexpressioninaorticvascularsmoothmuscletissuescouldberegulatedbyTE:99.50±21.74,125.38±28.68and101.98±15.42forTEconcentrationsat2.5mg/kg,5.0mg/kgand10.0mg/kg,respectively,theexpressionofER-βcouldberegulatedbyTE:92.34±18.68,47.72±18.12,82.13±23.50,andtheexpressionofPDGFR-βcouldberegulatedaswellbyTE:219.70±45.59,50.16±9.72,125.36±15.74(DataforAR,ER-βandPDGFR-βproteinbandintensitywereexpressedwithx±s,withcontrolgrouptakenas100).ConclusionsThisstudyindicatesthatandrogenshavesignificanteffectsonserumlipidsandlipoproteinmetabolism.Testosteroneenanthateat5.0mg/kgcanstimulatetheexpressionofAR,butinhibitetheexpressionofPDGFR.Testosteroneenanthateattheconcentrationsof5.0mg/kgand10.0mg/kgcaninhibitetheexpressionofER-β.

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简介：9月7日，FreeBSD项目组发布FreeBSD6．0-Beta4版。这是继7月15日发布FreeBSD6．0第一个测试版后推出的第四个Beta版本。FreeBSD6．0增加了更多无线网卡和无线安全标准支持，并且改进文件系统，支持对Linux所使用的ReiserFS文件系统进行读操作。FreeBSD项目组计划在FreeBSD6．0正式推出后，对FreeBSD开发网站进行改版。

简介：一套完全免费的动态域名解析服务客户端软件。当你安装并注册该项服务，无论你在任何地点．任何时间使用任何线路，均可利用这一服务建立拥有固定域名和最大自主权的互联网主机。“花生壳”支持的线路包括普通电话线．ISDN．ADSL、有线电视网络，双绞线到户的宽带网和其它任何能够提供互联网真实IP的接入服务线路，

简介：Texturepatternmappingisoneofthemostimportanttechniquesforhighqualityimagesyn-thesis.Itcanlargelyenhancethevisualrichnessofraster-scanimages.Inthispaperispresentedanewmethodofmappingplanartexturepatternontobeta-splinecurvedsurfaces——bilinearmappingmethodwhichcanmapplanartexturepatternontocurvedsurfaceswithlessdistortion,andalsocanfulfillthegeometrictransformationofthetexturepatternonthecurvedsurfacesbyoperatingthepatternwin-dow.ItisvaluabletobothCAD/CAMinartisticfieldandcomputergraphics.

简介：介绍了视频跟踪中图像边缘检测的基于Beta样条函数的边缘检测算子,该算法是利用Beta样条函数对原始图像进行拟合,然后求拟合曲面的二阶导数零交叉点来检测图像的边缘.根据Beta样条函数的局部性质得到具体卷积模板,由于它具有两个自由参数,使它比B样条边缘检测算子具有更大的灵活性.

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简介：Toinvestigatetheprevalenceandgenotypeofextendedspectrumbeta-lactamases(ESBLs)mediatedbyplasmidinGram-negativebacteriafoundinsouthernChina,atotalof1184clinicalisolatesofnon-repetitivestrainsofGram-negativebacteriawerecollectedin2001from5differentcitiesinsouthernChina.TheESBLs-producingisolatesweredistinguishedbymeansofthephenotypeconfimatorytestbasedontheNCCLScriteriaandweresubjectedtoplasmidconjugationandelectroporationexperiments.Thoseclinicalisolatessucceededinplasmidtransfershadundergoneplasmidconjugationandelectro-transformation,plasmidDNAextractionandPstⅠdigestlinger-printinganalysis,aswellasthetmiversalprimerPCRamplificationoftheTEM,SHV,CTX-M,VEB,PERandSFOgenesandtheDNAsequencinginordertodeterminethegenotypesofESBLsandtheirplasmidlocations.ItwasfoundthattheincidenceoftheESBLs-producingstrainsofGram-negativebacteriawas14.6%(173/1184)with67strainsoftransconjugantsand11strainsofelectro-transformants,inwhichCTX-M-14typewas33.3%(26/78);CTX-M-3typewas23.1%(18/78);CTX-M-9typewas14.1%(11/78);CTX-M-5typewas6.4%(5/78);CTX-M-13typewas2.6%(2/78);SHV-5typewas7.7%(6/78);SHV-12typewas5.1%(4/78),SHV-2atypewas2.6%(2/78)andunidentifiedtypewas5.1%(4/78).29.5%ofthewildstrainsalsocarriedbroad-spectrumbeta-lactamasesTEM-1andSHV-1types.TheabovementionedESBLsgeneswerelocatedontransferableplasmidswithvariablesizes(from35to190kb).TheCTX-MtypeESBLswascharacterizedbyhigh-levelofresistancetocefotaxime.ItconcludedthattheCTX-M-typewasthemostprevalentgenotypeinclinicalisolatesofGram-negativebacteriainsouthernChina,andtheSHVtyperanksinthesecondplace.TEM-,VEB-,Toho-andPER-typeswerenotfoundintheseisolates.

简介：Thefastions,producedinD-3Hefusionplasma,arethe14.7MeVprotonsand3.6MeVαparticles.Becausetheirslowingdowntimesarefinite,therefore,theydevelopacertainamountofadditionalbeta(fir)whichhastobesupportedbythemagneticfield.

简介：DWR开发小组近日宣布DWR1．1Beta3发布了。

简介：甘氨酸甜菜碱是植物细胞内一种重要的调渗物质，盐胁迫下，甘氨酸甜菜碱的积累可以保护细胞内蛋白质的结构和功能，降低细胞水势，从而增强植物自身的耐盐能力。从大肠杆菌中克隆的胆碱脱氢酶基因（betA）是甘氨酸甜菜碱合成的关键酶基因，该基因编码的胆碱脱氢酶（CDH）可将胆碱一步合成为甜菜碱。本实验室已将胆碱脱氢酶基因（betA）转入到小黑杨花粉植株基因组中，并最终获得了4个转基因株系。本研究以4个转betA基因株系（TB1、TB2、TB3、TB4）及非转基因对照为试材，在浓度为1．2％的NaCl盐胁迫下，测定其甜菜碱含量、超氧化物歧化酶（SOD）活性、过氧化物酶（POD）活性和丙二醛（MDA）含量，并调查试材的盐害情况，计算盐害指数，目的是为了研究转基因株系的耐盐效果，从中筛选出耐盐能力较强的转基因株系。试验结果表明，4个转基因株系的甜菜碱含量均高于非转基因对照；在1．2％NaCl胁迫下TB1、TB2、TB3的超氧化物歧化酶活性、过氧化物酶活性均高于非转基因对照，TB3低于对照：TB1、TB4的丙二醛含量低于对照，TB2、TB3与对照相近。进一步的盐害分析表明4个转基因株系中的TB1和TB4株系的盐害指数低于对照的42．1％和33．4％，TB2、TB3与对照无显著差异。综合各转基因株系的耐盐性及生理指标测定结果，4个转基因株系中，TB1、TB2的耐盐性明显优于对照，有希望用于盐碱地造林及推广。

简介：CellsregulatephospholipaseD(PLD)activityinresponsetonumerousextracellularsignals.Here,weinvestigatedtheinvolvementofPLDactivityintransforminggrowthfactor-β(TGF-β1)-mediatedgrowthinhibitionofepithelialcells.TGF-β1)-mediatedgrowthinhibitionofepithelialcells.TGF-β1inhibitsthegrowthofMDCK,Mv1Lu,andA-549cells.Inthepresenceof0.4%butanol,TGF-β1inducesanincreaseintheformationofphosphatidylbutanol,auniqueproductcatalyzedbyPLD.TGF-β1alsoinducesanincreaseinphosphatidicacid(PA)levelinA-549andMDCKcells.TGF-β1inducesanincreaseinthelevelsofDAGlabeledwith[^3H]-myristicacidinA-549andMDCKcellsbutnotinMv1Lucells.NoincreaseofDAGwasobservedincellsprelabeledwith[^3H]-arachidonicacid.ThedatapresentedsuggestthatPLDactivationisinvolvedintheTGF-β1-inducedcellgrowthinhibition.

简介：Betaeffectsonsurfaceflowsinarotatingannuluswitharadialtemperaturegradientandaslopingbottomwerestudiedexperimentally.AnazimuthaljetwasproducedbytheactionoftheCoriolisforceintheconvectiveregionbetweenthetwosidewallsoftheannulus.Propagatingvelocityandpatternsofthebaroclinicwaveonthesurfacewereobtainedbyusingafrequency-meterandastreakphotographrespectively.Itisshownthatthereexiststhenonlinearinteractionbetweenthebaroclinicandbetaeffects.Thebetaeffectexertslittleinfluenceonthestratificationflowsandconstrainsthebaroclinicinstability,anditpromptstheinstabilityoftheweakstratificationflowsandresultsinthesurfacepatternofwaveswithhigherfrequency.Itisalsoindicatedthatthebetaeffectcanreducethepropagatingspeedofthesurfacewavesinthejet,andincreasethethermalRossbynumberforthosesamesurfacepatternsunderagivenTaylornumber.

简介：Blendsofpoly(3-hydroxybutyrate-co-3-hydroxyhexanoate)(PHBHHx)andpoly(butylenesuccinate-adipate)(PBSA),bothbiodegradablesemicrystallinepolyesters,werepreparedwiththeratioofPHBHHx/PBSArangingfrom80/20to20/80bymeltmixingmethod.Differentialscanningcalorimetry(DSC),thermogravimetryanalysis(TGA),dynamicmechanicalthermalanalysis(DMA),polarizingopticalmicroscopy(POM)andwideangleX-raydiffractometer(WAXD)wereusedtostudythemiscibilityandcrystallizationbehaviorofPHBHHx/PBSAblends.ExperimentalresultsindicatethatPHBHHxisimmisciblewithPBSAasshownbythealmostunchangedglasstransitiontemperatureandthebiphasicmelt.