共查询到20条相似文献,搜索用时 15 毫秒
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目的克隆人RHD基因,并对其进行鉴定。方法以RhD阳性志愿者骨髓为材料,用TRIzol试剂提取总RNA;设计、合成人RHD基因扩增引物,RT-PCR方法扩增RHD基因片段;T/A克隆后将其亚克隆人pET28a(+)载体中,经酶切、PCR和测序对重组质粒进行鉴定。结果骨髓总RNA被成功提取;RT-PCR成功扩增出RHD基因片段,其大小与预期约509bp基本一致;T/A克隆后再将其亚克隆,通过酶切和PCR证明RHD基因成功亚克隆入pET28a(+)载体中;基因测序结果比对显示,与已公布的RHD基因(GenBank登录号为NM016124)序列基本一致,同源性为98%。结论成功克隆了RHD基因,这将为进一步研究奠定基础。 相似文献
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Arterial distribution of the upper lip was investigated in this study. The location, course, length, and diameter of the superior labial artery and its alar and septal branches were determined on 14 preserved cadaver heads. Another cadaver head was used to show the arterial tree by the colored silicone injection technique. The superior labial artery was the main artery of the upper lip and always originated from the facial artery. The superior labial artery was 45.4 mm in length, with a range from 29 to 85 mm. The mean distance of the origin of the superior labial artery from the labial commissura was 12.1 mm. The superior labial artery was 1.3 mm in external diameter at its origin. The mean distance of origin of the superior labial artery from the lower border of the mandible was 46.4 mm. The alar division of the superior labial artery was mostly found as a single branch (82 percent). Its mean length was 14.8 mm and the mean diameter at the origin was 0.5 mm. The distance between the origins of the superior labial artery and the septal branch was 33.3 mm. The septal branch was single in most of the cases (90 percent). The mean length of the septal branch was 18.0 mm and the diameter at its origin was 0.9 mm. After all dissections, it was concluded that the arterial distribution of the upper lip was not constant. The superior labial artery can occur in different locations unilaterally and bilaterally, with the branches showing variability. 相似文献
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用ISSR分子标记对内蒙古地区刺叶柄棘豆(Oxytorpis aciphylla Ledeb.) 5个地理种群进行了种群遗传多样性分析。结果表明:刺叶柄棘豆种群具有较高的遗传多样性,11个ISSR引物扩增出215条带,总的多态位点百分率为98.14%,Shannon多样性指数I=0.2108,Nei基因多样性指数 H=0.341 6,种内总基因多样性(Ht) 为0.2108,种群内基因多样性(Hs)为0.160 4, 大部分遗传变异(76.11%)的遗传变异存在于种群内, 23.89%的遗传变异存在于种群间。遗传分化系数(Gst)为0.238 9,基因流(Nm)为1.592 9。5个居群间已有遗传分化趋势,遗传漂变不会引起遗传分化。UPGMA遗传距离聚类结果表明, 5个地理种群中,植被类型为荒漠草原的4个种群之间遗传距离较近,与1个荒漠种群距离较远。 相似文献
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逆相蒸发法制备茶多酚脂质体及质量评价 总被引:1,自引:0,他引:1
采用逆相蒸发法制备茶多酚脂质体并进行质量评价。通过二次回归旋转组合设计优化茶多酚脂质体制备工艺及配方,对其形态、结构、粒径分布等性质进行考察。研究结果表明,最佳配方为m(大豆卵磷脂):m(胆固醇)=3:1、茶多酚质量浓度为7mg/mL、V(有机相):V(水相)=4:1、磷酸盐缓冲液浓度15mmoL/L,此条件下包封率为50.37%;所制备的茶多酚脂质体形态呈圆球形或椭球形,为大单室脂质体,有效粒径为165.3nm,Zeta电位为-69.3mV。逆相蒸发法制备茶多酚脂质体方法简单可行,所制备的脂质体具有一定缓释性。 相似文献
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Massatoshi Kondoh Ayumi Murakami Chiaki Shigeta Shizufumi Tanimoto 《Plant Growth Regulation》1999,28(2):107-116
The flower-inducing and -inhibiting activities of phloem exudate (PE) prepared from cotyledons of Pharbitis seedlings were examined, using apex cultures in vitro from Pharbitis as a bioassay system.The PE was prepared from photoperiodically-induced cotyledons (SD-PE). The SD-PE was subjected to the following fractionations: When the SD-PE was extracted with CHCl3 and then ethyl acetate, the inducing activity was located in the final aqueous fraction. The activity was localized in the diffusate when the aqueous fraction was dialyzed (molecular weight cut off was 10,000). The diffusate was fractionated by ion exchange chromatography, and flower-inducing activity was found in the fraction adsorbed onto anion exchange resin. When the fraction was applied to a Sep-Pak C18 cartridge, the activity eluted with 25% MeOH. As a result of the above fractionation, activity was increased about 30-fold.The nature of the flower-inhibiting activity of the PE taken from cotyledons exposed to continuous-light conditions was examined (CL-PE). The inhibiting activity was decreased as the cotyledons were exposed to longer dark periods; it appeared to be heat-stable. The CL-PE also inhibited flowering in Lemna. The CL-PE was subjected to the following fractionations: When the CL-PE was extracted with CHCl3 and ethyl acetate, activity was located in the final aqueous fraction. Activity was localized in the diffusate when the aqueous fraction was dialyzed (molecular weight cut off was 10,000). When the diffusate was fractionated by ion exchange chromatography, the activity was found in the flow-through fraction. When the fraction was applied to a hydroxyapatite cartridge, the activity eluted with 25 mM sodium phosphate buffer. When the fraction was re-dialyzed (molecular weight cut off was 1,000), the diffusate contained the activity. As a result of the above fractionation, activity was increased about 10-fold. 相似文献
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S. G. Gyulakhmedov Y. A. Omarov Z. M. Mamedov A. A. Kuliev 《Applied Biochemistry and Microbiology》2006,42(5):468-471
The activity of ATP-dependent phosphofructokinase (PFK) from subepidermal tissue of apple fruits was studied. The enzyme extracted under optimal conditions was stable for 14 h at room temperature. The enzyme was partially purified by ammonium sulfate fractionation and dialysis. PFK from apple fruits was found to be ATP-, UTP-, and CTP-specific. It was inhibited by PEP, Gly-2-P, Gly-1,3-DP, and ADP. The effect of the listed inhibitors was diminished by the presence of phosphate. The activity of PFK was stimulated by magnesium cations. The activity of the enzyme in fruits of an Antonovka cultivar was higher than in the Simirenko rennet cultivar by a factor of 1.3. 相似文献
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以白腐菌为出发菌株,利用紫外线(UV)进行诱变,筛选高产漆酶突变菌株。通过测定致死率绘制出发菌株的致死曲线,采用PDA-RBBR平板变色法进行初筛,ABTS检测酶活对突变株进行摇瓶复筛。结果表明:利用15 w紫外灯在照射距离为30 cm,照射时间为120 s,致死率为72.1%的条件下进行诱变处理,获得一株高产菌株,其酶活提高79.54%,经过5代传代培养,未见酶活下降,具有较好的遗传稳定性,进一步研究了初始pH值,接种量和培养基装液量等对诱变菌株产酶的影响,结果表明在最佳的培养条件pH值6.0,15%的装液量于28℃下,酶活达214.9 U/L。 相似文献
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【目的】利用筛选培养基,从肉牛瘤胃液中分离筛选产乙酰酯酶的细菌菌株,并研究菌株的产酶特征。【方法】利用厌氧培养技术,以木质素为唯一碳源,筛选并驯化所得菌株。根据菌株16S rDNA序列分析、革兰氏染色、伊红美蓝培养基培养、甲基红试验和柠檬酸盐利用试验,鉴定菌株。采用对-硝基苯乙酯测定酶活力。【结果】筛选得到产乙酰酯酶活力较高细菌菌株RB1,初步鉴定为Escherichia coli。菌株RB1的生长曲线表明,0 42 h为菌株的延迟期,42 60 h为菌株的对数期,60 66 h为菌株的稳定期,66 86 h为菌株的衰亡期。菌株所产乙酰酯酶最适温度为40°C,最适pH为8.0,在最适温度与pH条件下,培养基中添加玉米秸秆粉,乙酰酯酶最高酶活力达到0.52 U/mL。【结论】筛选获得产乙酰酯酶的细菌菌株RB1,其乙酰酯酶活力高于已报道的菌株,是一株具有研究和应用潜力的产乙酰酯酶的菌株。 相似文献
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A Monascus pilosus strain was selected for production of intracellular alpha-galactosidase. Optimum conditions for mycelial growth and enzyme induction were determined. Galactose was one of the best enzyme inducers. The enzyme was purified by ammonium sulfate precipitation, gel filtration, and ion exchange chromatography and was demonstrated to be homogeneous by slab gel electrophoresis. The molecular weight of this enzyme, estimated by gel filtration, was about 150,000. The optimum conditions for the enzyme reaction was pH 4.5 to 5.0 at 55 degrees C. The purified enzyme was stable at 55 degrees C or below and in buffer at pH 3 to 8. The activity was inhibited by mercury, silver, and copper ions. The kinetics of this enzyme, with p-nitrophenyl-alpha-d-galactoside as substrate, was determined: K(m) was about 0.8 mM, and V(max) was 39 mumol/min per mg of protein. Enzymatic hydrolysis of melibiose, raffinose, and stachyose was analyzed by thin-layer chromatography. 相似文献
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内切葡聚糖酶基因在巨大芽孢杆菌中的表达及其酶学性质研究 总被引:1,自引:0,他引:1
通过PCR方法将已克隆的内切葡聚糖酶基因(GenBank No. DQ782954)信号肽编码序列去除, 然后与表达载体pHIS1525连接后转化大肠杆菌DH5a, 筛选出阳性转化子DH5 a -pHIS1525-G7并提取质粒进一步转化巨大芽孢杆菌WH320原生质体, 获得基因工程菌WH320-pHIS1525-G7。刚果红染色和SDS-PAGE分析表明该基因在巨大芽孢杆菌中得到了有效表达。基因工程菌经优化培养后, 胞外上清液中的酶活力可达889 U, 是出发菌株(即枯草芽孢杆菌C-36)的11.22倍。酶学性质研究表明: 该酶的最适反应温度与pH值分别为65℃与pH 6.0, 在pH 4.5~10.0范围内50℃保温30 min可保持在最高酶活的80%以上。 相似文献
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目的:建立肾衰康浓缩丸质量控制方法。方法:采用TLC鉴别肾衰康浓缩丸中大黄、丹参;采用HPLC-ELSD对制剂中黄芪甲苷进行含量测定,流动相为乙腈-水(30:70),流速:1 mL/min,柱温:28℃,漂移管温度:42℃,氮气:355kPa。结果:大黄、丹参的TLC鉴别斑点清晰、专属性强;黄芪甲苷在1.0μg-10.0μg之间呈良好的线性关系(r=0.9997,n=5),平均回收率为99.81%,RSD为1.73%(n=6)。结论:所建立的方法简便准确、专属性强、重现性好,可作为控制肾衰康浓缩丸质量的方法。 相似文献
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目的:利用AdEasy腺病毒表达系统构建含有小鼠脂肪储存小滴蛋白5(LSDP5)基因的重组腺病毒。方法:从小鼠肝脏cDNA克隆出LSDP5基因全长,克隆至pMD18-T载体中,酶切测序。回收酶切产物,连接到腺病毒穿梭载体pShuttle-CMV,构建pShuttle-CMV-LSDP5重组质粒,经PmeI酶切线性化后转化至含有腺病毒骨架质粒pAdEasy-1的BJ5183中。筛选阳性克隆,提取重组质粒,PacI酶切线性化并转染AD293细胞进行包装,提取病毒DNA,鉴定重组病毒并检测病毒滴度。结果:LSDP5基因克隆经测序证实与Genebank公布一致,双酶切重组pMD18-T载体得到1400 bp左右的片段。重组穿梭载体经Kpn I和Sal I双酶切后得到预期片段。PacI酶切得到30 Kb大片段和4.5 Kb小片段。转染AD293细胞后收集病毒,经PCR鉴定,获得理想的目的片段。取病毒上清反复感染AD293细胞以扩增病毒,最后所得病毒滴度为2.5×109pfu/ml。结论:成功构建了携带脂肪储存小滴蛋白5基因的重组腺病毒载体,为进一步研究LSDP5基因功能奠定基础。 相似文献
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枯草芽胞杆菌微生态制剂的研制 总被引:4,自引:0,他引:4
采用液体发酵工艺,确定枯草芽胞杆菌的最适发酵条件为:发酵温度30℃,初始pH值7.2,并以1%海藻酸钠和3%明胶组成的混合胶体溶液为囊壁材料,以4%氯化钙作固化剂将枯草芽胞杆菌制成微胶囊剂,稳定性试验结果显示经微胶囊包埋的枯草芽胞杆菌制剂,室温下保存1个月,活菌存活率为98.8%,保存3个月,活菌存活率为50.6%,保存6个月,活菌存活率为15.7%,均高于未经微胶囊化的样品;在4℃冷藏下保存3个月,未经微胶囊化的样品活菌存活率仅为经微胶囊包埋制剂的66.2%。该微胶囊制剂提高了活菌存活率,延长了活菌常温保存期。 相似文献
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首次将胞外邻苯二酚1,2-双加氧酶固定化,并用于制备顺,顺—己二烯二酸.该固定化酶表观活力高,使用范围扩大,耐酸性及耐碱性都有显著提高,并且使用稳定性好,得到的产物浓度及纯度均较高,酶与产物容易分离,整个工艺简单、独特、新颖,有利于工业化应用. 相似文献
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经硫酸铵分级沉淀,离子交换层析和凝胶过滤等步骤,从人肝中获得了PAGE单一条带的谷胱甘肽过氧化物酶,比活提高120倍,得率为25%。凝胶过滤法测得分子量为90980,SDS-PAGE测定亚基分子量为22423.原子吸收法测得每分子酶含有四个硒原子。等电聚焦显示该酶等电点为5.0.酶活力的最适pH为8.5,最适温度为37℃。动力学实验提示该酶作用机理属于乒乓机制型。 相似文献
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Nakamura K Nakamura M Yoshikawa H Amano Y 《Bioscience, biotechnology, and biochemistry》2001,65(1):102-108
A key enzyme of the thiosulfate oxidation pathway in Acidithiobacillus thiooxidans JCM7814 was investigated. As a result of assaying the enzymatic activities of thiosulfate dehydrogenase, rhodanese, and thiosulfate reductase at 5.5 of intracellular pH, the activity of thiosulfate dehydrogenase was measured as the key enzyme. The thiosulfate dehydrogenase of A. thiooxidans JCM7814 was purified using three chromatographies. The purified sample was electrophoretically homogeneous. The molecular mass of the enzyme was 27.9 kDa and it was a monomer. This enzyme had cytochrome c. The optimum pH and temperature of this enzyme were 3.5 and 35 degrees C. The enzyme was stable in the pH range from 5 to 7, and it was stable up to 45 degrees C. The isoelectric point of the enzyme was 8.9. This enzyme reacted with thiosulfate as a substrate. The Km was 0.81 mM. 相似文献