简介：使用含512个已知水稻基因3'表达序列标签的cDNA微阵列检测了萌发期水稻幼苗的基因表达谱.313个基因产生了可靠的杂交信号.其中,天冬氨酸氨基转移酶基因和4个具有核糖体功能的基因表达丰度非常高,表明萌发期幼苗中的氨基酸和蛋白质的合成代谢很活跃.β-1,3-葡聚糖酶基因是一种典型的病程相关基因,该基因的高水平表达,表明幼苗中存在着一种高度发育的抗病机制.实验也发现编码一种重要的抑制细胞凋亡的基因-Baxinhibitor-1,在幼苗中的表达丰度很高;该结果可解释为什么正常的幼苗中很少发生细胞程序性死亡现象.实验所测定的大量基因的表达丰度有助于从基因组转录水平理解萌发幼苗的生理特点.

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简介：数字阵列雷达是一种接收和发射波束都采用数字波束形成技术的全数字阵列扫描雷达.由于收发波束形成均以数字方式实现,因而它有较好的数字处理灵活性,拥有许多传统相控阵雷达所没有的优良性能.本文对数字阵列雷达进行了综述,主要介绍数字阵列雷达的基本概念、关键技术、研究进展、潜在的应用以及未来的发展趋势.

简介：MAUI12-BayHybridizationSystem微阵列杂交系统可用来适应高通量微阵列实验室的需求。这个系统可以在它独有的MAUIMixer杂交格仓中同时加工12个微阵列芯片，使用超低的样本量10-46微升就可以增加灵敏度达到3-10倍，通过在恒定的培养温度下与超微的杂交试剂的有效混合。

简介：对木头开发和形成的分子的生物研究是相关基因的发现的最近的年，而是步里的焦点，他们在木头性质的控制的函数是慢的。它在另外的工具上的高产量能力，敏感，和可靠性的优点为调查能够的基因表示patternsis开发了的microarraytechniquewith很快assaying几千基因。在这研究，从开发白杨木部纸巾的二个cDNA图书馆准备的cDNAmicroarray从Populusdeltoides的主要的茎在不同高度在不成熟的木部纸巾习惯于试金基因表示模式(15?岁)，它被证实有不同木头性质(microfibrillar角度，木质的密度)旁边X光检查。有在薄片之间的微分表示侧面的274个抄本外面被屏蔽，并且单个克隆受到5定序。用生物信息的分析，我们识别了可以影响白杨木头性质的候选人基因，许多哪个属于各种各样规章并且信号transduction基因家庭例如锌手指蛋白质抄写因素，DNA有约束力的抄写因素，乙烯反应因素等等。结果建议这些基因可以调整涉及木头形成的酶。进一步的工作将被执行克隆这些基因并且决定他们怎么影响白杨木头性质。

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简介：Phytohormoneabscisicacid(ABA)wascriticalformanyplantgrowthanddevelopmentalprocessesincludingseedmaturation,germinationandresponsetoenvironmentalfactors.WiththepurposetodetectthepossibleABArelatedsignaltransductionpathways,wetriedtoisolateABA-regulatedgenesthroughcDNAmacroarraytechnologyusingABA-treatedriceseedlingasmaterials(undertreatmentfor2,4,8and12h).Of6144cDNAclonestested,37differentialclonesshowinginductionorsuppressionforatleastonetime,wereisolated.Ofthem30and7wereup-ordown-regulatedrespectively.Sequenceanalysesrevealedthattheputativeencodedproteinswereinvolvedindifferentpossibleprocesses,includingtranscription,metabolismandresistance,photosynthesis,signaltransduction,andseedmaturation.6cDNAcloneswerefoundtoencodeproteinswithunknownfunctions.RegulationbyABAof7selectedclonesrelatingtosignaltransductionormetabolismwasconfirmedbyreversetranscriptionPCR.Inaddition,somecloneswerefurthershowntoberegulatedbyotherplantgrowthregulatorsincludingauxinandbrassinosteroid,which,however,indicatedthecomplicatedinteractionsofplanthormones.PossiblesignaltransductionpathwaysinvolvedinABAwerediscussed.

简介：FemaleinflorescenceofBetulaplatyphyllawassampledatanintervalofeachtwodaystoanalyzethebackgroundofgeneexpressioninfloralphase.OnthebasisofSMARTstrategy,thedrivercDNAwasobtainedfromtotalRNAofthelastsampleandthetestercDNAwasfromthatoftheothersbyRT-PCRwhichweresubsequentlyusedtoconstructasubtractedcDNAlibrary.TheresultoftheESTs(expressionsequencetags)blastXshowedthatthegenesinthesubtractedcDNAlibrarycouldbemainlyclusteredinto5groupsrelatedtometabolism,transportationandsignaltransduction,cellcycle,stressresponse,andregulation.Therelationshipbetweengeneexpressionanddevelopmentwasalsodiscussed.

简介：Objective:Toclonemultidrugresistance(MDR)relatedgenesinlungadenocarcinomacelllines.Methods:ThedifferentiallyexpressedcDNAfragmentsbetweenA549andA549DDPcellswereanalyzedbymRNAdifferentialdisplayPCR(DDRT-PCR).ThefragmentsthusobtainedwerefurtheranalyzedbyDNAsequencingandNorthernblotting.Results:ThreedifferentiallyexpressedcDNAfragmentswereobtainedandconfirmedbyNorthernblot.Sequenceanalysisrevealedthattwoofthemwerenovelandonewas100%identicalwithICEgene.Conclusion:AnalyzingdifferentiallyexpressedfragmentbetweenA549andA549DDPcellsmaybehelpfulforfindingnewMDRrelatedgenes.ThedrugresistanceofA549DDPcellsmayberelatedtotheinhibitionordown-regulationofICEgene.

简介：目的：克隆COPS3基因cDNA,构建其原核融合蛋白表达载体并表达和鉴定。方法：从培养的人骨肉瘤细胞系SOSP-9607细胞中提取总RNA,经RT-PCR获得COPS3基因。将该基因克隆到pGEM-T-Easy载体中,酶切及测序鉴定。将COPS3基因插入pET28a融合蛋白表达载体中,IPTG诱导表达,进行SDS-PAGE分析。免疫印迹法鉴定COPS3蛋白的表达。结果：cDNA测序证明,获得了COPS3基因cDNA,其序列与Genebank中报道序列完全一致。酶切分析表明,成功构建了含COPS3基因的pET28a融合蛋白表达载体。SDS-PAGE以及免疫印迹法鉴定分析表明,COPS3蛋白获得高效表达,分子质量为51Ku,表达量约占菌体总蛋白的30%。结论：成功克隆和表达了COPS3cDNA。

简介：微电子学的发展彻底改变了计算机的设计:集成电路技术增加了单个芯片中的元器件数目及其复杂度.因此,采用这种技术可以构建低成本、专用的外围器件,从而迅速地解决复杂的问题.

简介：曼切斯特大学发明的一种新颖、成本低、重量轻、极宽带阵列天线具有双偏振能力的天线阵列。该天线阵列的频率比〉3：1，使其应用范围可以扩展到更多领域。它可以作为一个可操纵的阵列（发送，接收或两者），并具有低的交叉极化水平。同时它也可以进行多种传输服务。该天线应用领域包括移动／海洋通信，国防／安全，雷达成像，医疗保健监测等。其频率可扩展到3．0GHz、10GHz，甚至上限可达60至120GHz。此为，它还具有成本低、易于制造、尺寸小、重量低、易于安装等优点。

简介：LittleDipper微阵列处理系统是一种经济适用的工具，它用于实验室标准微阵列杂交、洗涤和干燥，目标是减少实验室水浴之间和实验人员之间在微阵列分析结果上的系统误差。它包括一个可旋转的自动臂，可以移动微阵列架．通过5个温度控制水浴并放置到一个整合的离心机用于干燥。

简介：阵列代数与高阶矩李作发，罗玉芳（武汉测绘科技大学，武汉４３００７０）在概率中，ｎ维随机变量的协方差阵表达了各分量围绕它们的数学期望的疏散程度，以及各分量间相关程度的一组数字特征．我们将利用阵列代数引进ｔ个ｎ维随机向量的各分量间相关程度的ｔ阶相关中心矩...

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简介：摘 要：本文将相控阵之间的近场耦合等价于元素远场耦合的叠加。提出了发射相控阵与接收相控阵耦合的噪声功率计算方法。该方法也适用于发射信号的耦合。仿真计算由Matlab进行计算。

简介：TherootofPanaxginsengplantundergoesaspecificdevelopmentalprocesstobecomeabiosynthesisandaccumulationtissueforginsenosides.Toidentifyandanalyzegenesinvolvedinthebiosynthesisofginsenoside,weconstructedandcharacterizedafull-lengthcDNAlibraryfor6-year-oldNorthAmericanginseng.ThetiterofprimarycDNAlibraryis1.2×106pfu/mL,thetiterofamplifiedlibraryis2.6×1010pfu/mLandtherateofrecombinantisabove86%.Theinsertsizerangesfrom0.3to2.0kb.Sequencingresultsshowthat18of58genesarehighhomologoustothegenes(GBR5,GBR3andGBR1)knowninGenBank,whichareinvolvedinbiosynthesisofginsenosideinNorthAmericanginsengplant;16of58genesarenovelgenes.Thefull-lengthcDNAlibraryofNorthAmericanginsengroottissuesisessentialforthecloningofgenesknownanditisalsoaninitialkeyforthescreeningandcloningofnewgenes.

简介：Objective:Toanalyzethechangesofgeneexpressioninphenylbutyrateinduceddifferentiationofgliomacells.Methods:Theexpressionlevelsof14000genesingliomacellsbeforeandafterinducementwithsodiumphenyl-butyratefor2hor6dayswereevaluatedbycDNAarraytechniqueandprovedbymulti-dotblotting.Results:expressionof98genesingliomacellsshowedchangesaftertheinducement.Somegenesinvolvedintranscriptionandtranslationandsomeoncogenesaredown-regulated,whilesomegeneinvolvedindifferentiationorapoptosisareup-regulated.18unknownexpressionsequencingtag(EST)changedtoo.Conclusion:Ageneexpressionprofileassociatedwithdifferentiationofgliomacellswasestablished.

简介：Throughexploitingthehighhomologyofcerealcropgenes,membranouscDNAmicroarrayscontaining3311uniquericetranscripts(including1639cndosperm-derivedtranscriptsand1672maturestem-derivedtranscripts)wereusedformonitoringtheexpressionprofilesofl-leafstageseedlingsof4cerealcropspecies:rice,maize,sorghumandbarley.Afterhybridizingwith[P]labeledprobes,73.6%ofthearrayedgenesgeneratedreliablesignalsinallofthefourcerealcrops.Furtheranalysisrevealedthatamongthearrayedgenes,ahigherpercentageoftheendosperm-derivedtranscripts(86.6%)expressedthanthatofthematurestem-derivedgenes(60.9%),indicatingthatmostoftheendospermexpressedgenesfunctionedinyoungseedlingswhilcconsiderableamountofmaturestemtissueexpressedgenesdidnotexpress.Theseresultsalsoinferredthatsomegenesmightfunctiononlyatcertaindevelopmentalstages.Bycomparingtheobtainedprofdes,84geneswereidentifiedconstantlyexpressedinallthefourcerealcrops.Manyhousekeepinggenes,suchaspolyubiquitin,ubiquitinconjugatingenzymeandribosomalproteinswereincludedinthiscatalogue.Theexperimentalsoidentified14riceseedlingspecificallyexpressedgenes,including3bioticandabioticstressinducedgenesand1apoptosissuppressorencodinggeneBaxinhibitor-1.Thisinvestigationprovidedinvaluableinformationforcomparativegenomicsofgramineaemembers.

简介：Twostarch-branchingenzyme(SBE)inrice,isknowntobeakeyenzymeinamylopectinbiosynthesis.ThecDNAoftwoSBE(starch-branchingenzyme)genesSheIandShedencodingSBEⅠandSBEⅢ(twomajorisoformsinrice)wereclonedbyanimprovedRT-PCRtechnique,fromatemplatecDNAlibray,derivedfromthetotalmRNAsextractedfromtheimmatureseedsofajaponicariceWuyunjing7.DNAsequenceanalysisshowedthatthesizeoftheclonedSheIandShedcDNAswere2490and2481bplong,respectively,includingtheirentirecodingsequences.ComparisonanalysisindicatedthatthenucleotidesequenceofShe3wasthesameasthatofshed(GenbankAccessionNo.D16201)asreportedpreviously.Therewereonlyfourbase-pairsdifference,whichresultedinchangesoftwodeducedaminoacidsbetweentheclonedShe1cDNAandthereportedshe1(GenbankAccessionNo.D11082).TheclonedSheIandShedcDNAsmakeitpossibletoimprovericestarchqualitythroughgeneticengineering.