简介:目的选择弓形虫RH株主要表面抗原P30、P22的有效基因片段和霍乱毒素A2/B亚基共同构建在同一真核表达载体pcDNA3.1(-)上,并保证其连接方向和开放读码框的正确.方法用PCR技术分别从弓形虫RH株基因组DNA和pUAB024-CTXA28/B质粒中扩增编码P30、P22基因片段和CTXA2/B,定向重组入pUC18克隆载体,然后酶切释放P30-P22-CTXA2/B复合基因片段,亚克隆入pcDNA3.1(-)真核表达载体,再经含氨苄青霉索的LB培养基筛选、酶切及测序鉴定.结果酶切产物经电泳显示条带清晰,P30、P22和CTXA2/B基因片段的泳动位置分别在786bp、492bp、512bp的位置,与预计结果一致;测序结果表明插入的基因片段方向及序列均正确.结论成功地构建了真核表达重组质粒pcDNA3.1-P30-P22-CTXA2/B,保证了三个基因连接方向,序列及开放读码框的正确,为下一步融合蛋白P30-P22-CTXAA/B在哺乳动物细胞中的表达及动物实验奠定了基础.
简介:ThecompressionbehaviourofPd39Ni10Cu30P21bulkmetallicglassisivestigatedatroomtemperatureupto23.5GPausinginsituhighpressureenergydispersivex-raydiffractionwithasynchrotronradiationsource.Pressureinducedstrucuralrelaxationofthebulkmetallicglassisexhibitedwithinthepressurerange.Itisfoundthatbelowabout5GPa,theexistenceofexcessfreevolumecontributestorapidstructuralrelaxation,whichgivesrisetorapidvolumeticchange.Underhigherpressure,furtherrelaxationresultsinstructuralstiffness.
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简介:引进分次Armendariz环的概念,讨论了分次环R=n∈ZRn及由它导出的非分次环R,R0,及R[x]之间关于Armendariz环性质的关系,并推广了[8]的结论,得到在R=n∈ZRn是Z-型正分次环的前提下,若R是分次Armendariz,分次正规环,则R是P.P.环(Baer环)当且仅当R是分次P.P.环(分次Baer环).
简介:AsoilpotcultureexperimentwithfoursuppliedPlevels(i.e.P30,P50,P100,P200,representingsupplementalP30,50,100,200mg/kg,respectively)wasconductedtoinvestigateuptakeanduseabilitytoPandZninthericegenotypeswithdifferentP-efficiency,ofwhichricegenotypes508,99011,580,99112werelow-Ptolerantand99056,99012werelow-Psensitive.Low-Ptolerantrice580and99011absorbedmorePthantheothers,andricegenotype580hadstrongeruptakeabilityespeciallyatlow-PlevelsuchasP50andP30.508couldabsorbconsiderableP,andhadthelowestPpercentageofshoot,indicatingithadgoodperformanceinP-useefficiency.ThesethreericegenotypeshadlargerbiomassandlessresponsetochangedPlevelthanricegenotype99112,99056and99012.Ricegenotype99112showedLow-Ptolerancemainlybysacrificingbiomasstomaintainhighrelativegrainyield.TheleastamountofPabsorbedby99056showedithadthelowestPuptakeefficiency,andthehighestPpercentageinshootof99012meantithadthelowestPuseefficiency.Sotheytwoshowedlow-Psensitivity.ZncontentsinshootunderP200,P100andP50weresimilar,butP30increasedZncontentinshootsignificantly.TheZncontentsinshootof99112,99056and99012werehigherthanthoseof508,99011and580,especiallyattilleringstageandbootingstage.AsfortotalZncontentinshoot,Low-Ptolerantricegenotype580hadthelargestamountandfollowedby99011and508,low-Ptolerantricegenotype99012hadthesmallestamountatthethreesamplingstageandfollowedby99056.Furthermore,P/Zninshootof99012wasthehighest,andthatof99056wasthesmallestatthesamePlevel.