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Search Results: 1 - 10 of 142062 matches for " 高晓冬 "
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A Study of the Karyotypes and C-bands of Paramesotriton caudopunclatus
尾斑瘰螈的核型和C带研究

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遗传 , 1997,
Abstract: The karyotpe and C-bands of Paramesotriton caudopunclatus Liu et Hu were studied by means of both conventional Giemsa staining and BSG technique.The diploid number of this species is 24,consisting of 9 pairs of metacentric and 3 pairs of submetacentric elements.All chromosomes have an inserted pericentric band in both chromosome arms except that Nos.11 and 12 chromosomes have an inserted pericentric band only in one chromosome arm.Besides the main bands,weak centromeric bands appear in all of the chromosomes.The karyotype and C-bands of Paramesotriton caudopunclatus indicated the dissimilary with other examined species in Chinese salamandrids.No heteromorphic pair of chromosomes was detected between male and female karyograms.
贵州疣螈的核型和C-带研究
,
动物学研究 , 1997,
Abstract: 贵州疣螈的核型和C-带研究ASTUDYONKARYOTYPESANDC-BANDINGSOFTylototritonkweichowensis关键词贵州疣螈,核型,ZW-染色体,C-带KeywordsTylototritonkweichowensis...
人体线粒体N-乙酰氨基葡萄糖转移酶在酿酒酵母中的表达
韩宝仙,
- , 2016, DOI: 10.3979//j.issn.1673-1689.2016.09.013
Abstract: O-GlcNAc是一种广泛存在于蛋白质丝/ 苏氨酸残基上的动态可逆的蛋白质翻译后修饰方式,广泛分布在细胞浆和细胞核中,参与调节多种细胞途径。蛋白质的O-GlcNAc 糖基化与许多疾病密切相关,如糖尿病、神经退行性疾病和癌症等。在体内,O-GlcNAc 动态修饰由N-乙酰氨基葡萄糖转移酶(OGT) 和N-乙酰氨基葡萄糖苷酶(OGA ) 协同完成。OGT具有3种异构体,分别是ncOGT、mOGT和sOGT。目前对于 mOGT的功能和调节机制尚未清楚。作者在酿酒酵母细胞中表达了人源的mOGT,发现mOGT 抑制酵母细胞的生长。在酿酒酵母细胞中 mOGT 具有O-GlcNAc糖基化活性,当其活性位点突变后,O-GlcNAc糖基化活性明显降低,但其同样能抑制酵母细胞生长。作者在酿酒酵母细胞中构建了研究mOGT的系统。可以利用该人源化的酵母筛选和mOGT 相互作用的蛋白质和基因,也可以用来筛选抑制 mOGT 活性的药物,进而研究mOGT 的功能与调节机制。
N-acetylglucosamine(O-GlcNAc) modification on protein serines/threonines is a dynamic,inducible and abundant post-translational modification,which is found on numerous cytoplasm and nucleus proteins,regulating many cellular process. It has demonstrated that O-GlcNAc plays important roles in some human diseases,such as diabetes and neurodegenerative. O-GlcNAcylation cycle is regulated by O-GlcNAc transferase(OGT) and O-GlcNAcase(OGA) in vivo. There are three isoforms of OGT have been found in mammalian cell. They are nucleoplasmic OGT(ncOGT),mitochondrial OGT(mOGT) and shorter OGT(sOGT). We have expressed mOGT in yeast cells with a final goal to study its biological function. A certain number of yeast proteins were clearly revealed in mOGT overexpressed cells,demonstrating the activity of mOGT in yeast cells. Furthermore,it was found that human mOGT protein inhibited the cell growth of yeast. This humanized yeast strain can be used for studying the biological function and the regulation mechanism of human mOGT
大型桥梁钢沉井下沉过程局部冲刷研究
正荣,黄建维,
海洋工程 , 2006,
Abstract: 钢沉井下沉过程中局部冲刷的研究是同类桥墩设计和施工十分关心的重要课题,它对保证钢沉井安全有效施工、桥梁设计中施工期桥墩最大冲深、失稳和安全计算有重要参考价值.通过室内试验研究了钢沉井下沉过程中的局部冲刷机理和冲刷形态,探讨了桥墩下部钢沉井基础施工的相对高程对局部冲刷的变化规律,并将试验研究所获得的局部冲刷规律和影响因素,采用墩型系数方法引入局部冲刷计算中,给出了计算公式.研究成果补充了国家行业规范内容,对同类工程的设计、施工具有借鉴和指导意义.
南通地区城镇用地扩展时空特征分析
储金龙,, , 徐建刚
自然资源学报 , 2006, DOI: 10.11849/zrzyxb.2006.01.007
Abstract: ?以多时相LandsatTM/ETM卫星遥感影像为数据源,引入扩展速度、扩展强度、分维数、空间自相关指数等测度指标,分析了南通地区各类城镇的用地扩展过程、形态变化、结构分异及空间格局等时空特征。结果表明:①各类城镇用地扩展速度逐渐提高,扩展强度逐渐加大;②区域城镇用地扩展在1980年代以中心城市扩展为主,1990年代以后则以县(市)城和建制镇用地扩展为主;③因区域城市化进程加速和自然条件的影响,城镇用地分维数呈现逐渐增大的趋势,表明城镇用地的形态越来越不稳定;④城镇用地扩展主要以中、低速扩展类型为主;⑤城镇用地扩展速度、扩展强度的空间自相关性偏弱,但个别类型也呈现出集聚分布的趋势,如扩展速度的高值区域呈现出一定的临江和沿交通干线分布的特征,扩展强度的高值区围绕中心城市分布。
一种带储能功能的新型光伏并网逆变器研究
志刚,,
电网技术 , 2012,
Abstract: 为了减少光伏发电功率的波动,并进一步降低并网电流的谐波含量,提出了一种带储能功能的新型光伏并网逆变器,通过对光伏发电电能进行储存和释放,改善了光伏发电并网输出功率的波动问题。针对提出的逆变器拓扑结构,建立了相应的输出电压数学模型,并提出了一种新型调制算法达到了改善输出电压谐波特性的效果。实验结果表明,提出的并网逆变器工作正常,调制策略和控制算法有效可行,可实现对能量的存储和释放。
人工神经网络模型在油气层识别技术中的应用
徐景祯,,春文
天然气工业 , 1996,
Abstract: ?据油气层综合解释的特点,提出了单井油气层综合解释的人工神经网络方法.采用简单的分层网络、向后传播算法和误差逐次修正法建立的人工神经网络模型,是一个包含28个输入神经元、26个隐含神经元和4个输出神经元的三层网络.选择了松辽盆地北部大庆长垣以西地区91个已试油气层段的资料对网络进行了训练,通过对已知样品的交叉验证,训练后的神经网络识别符合率达93.4%,高于现场测井解释和综合判断的符合率.
osw2对酿酒酵母孢子固定化酶影响的分析
赵强,李子杰,中西秀树,
- , 2018, DOI: 10.3969/j.issn.1673-1689.2018.08.010
Abstract: 构建了α-半乳糖苷酶(Mel1p)的多拷贝质粒pRS426-TEFpr-MEL1,转入酿酒酵母野生型AN120及osw2Δ突变株并进行固定化酶活性测定。实验分别选取蜜二糖、棉子糖(三糖)与水苏糖(四糖)3种低聚寡糖作为Mel1p的底物,检测两种菌株孢子固定化酶对这3种底物的催化活性,结果表明野生型AN120酵母孢子壁的孔径最大只允许介于三糖和四糖之间的底物通过,四糖不能通过;而osw2?驻突变株酵母孢子壁的孔径可以允许四糖通过。通过孢子固定化酶保护性实验,发现孢子固定化酶可以完全抵抗2% SDS的处理,也可部分抵抗10% SDS的处理。通过8 mol/L尿素处理后,酶活检测发现野生型AN120酵母孢子可阻挡尿素对孢子固定化酶的影响,而osw2Δ孢子不能;蛋白免疫印迹分析进一步表明,尿素处理后野生型AN120酵母孢子固定化酶的含量几乎不变,而osw2Δ突变株孢子固定化酶的含量明显降低,说明尿素可进入osw2Δ突变株孢子内部溶解并降低固定化酶的含量,但对AN120酵母孢子影响。本研究也在多种突变株孢子中表达Mel1p,并进行活性比较,发现osw2,osw2Δydl186wΔ及osw2Δydr326cΔ突变株固定化酶均有很高的催化活性。
In this study,the multicopy plasmid pRS426-TEFpr-MEL1 expressing α- galactosidase enzyme(Mel1p) was transformed into the Saccharomyces cerevisiae AN120 wild type and osw2Δ mutant strains. Three different oligosaccharides(melibiose,raffinose and stachyose) were used as substrates to detect the catalytic activity of immobilized enzyme on yeast spores. The results indicated that the pore size of AN120 wild-type spore wall was larger than trisaccharide but smaller than tetrasaccharide;however,the pore size of osw2Δ mutant yeast spore wall was larger than tetrasaccharide. The protective assay of immobilized enzyme suggested that enzyme immobilized on wild type and osw2?驻 mutant spores can completely resist 2% SDS treatment and partially resist 10% SDS treatment. Wild type spore can resist the treatment by 8 mol/L urea,whereas osw2Δ mutant spore was sensitive to urea.Furthermore,western blot analysis showed that the amounts of enzyme in the wild type spores were stable after urea treatment,but the amounts of enzyme onosw2Δ mutant spores decreased significantly. These results demonstrated that urea could enter into osw2Δ mutant spores and dissolve the enzyme,leading to the decrease of the amount of enzyme. Moreover,the immobilized enzymes on osw2Δ,osw2Δydl186Δand osw2Δydr326cΔspores all have high catalytic activity
甘油激酶的表达纯化及在酮糖合成中的应用
吴晓茹,李子杰,中西秀树,
- , 2018, DOI: 10.3969/j.issn.1673-1689.2018.08.006
Abstract: 研究了大肠杆菌MG1655来源的甘油激酶(GK)的表达及其在酮糖合成中的应用。本研究从大肠杆菌MG1655扩增了甘油激酶的基因片段glpK,连接到表达载体pET-28a上,在大肠杆菌Rosetta(DE3)中进行IPTG诱导表达,利用Ni2+亲和层析柱纯化目的蛋白。利用该甘油激酶可以催化成本较低的底物甘油生成L-3-磷酸甘油,再经过磷酸甘油氧化酶(GPO)的催化生成磷酸二羟基丙酮(DHAP),生成的DHAP可以在不同的DHAP依赖性醛缩酶的催化下与受体D-甘油醛合成酮糖-1-磷酸,最终用酸性磷酸酶脱掉磷酸生成一系列酮糖。结果表明,该酶成功地用于“一釜多酶法”合成体系中,以便宜的底物甘油为前体,合成出包括稀有糖在内的一系列酮糖,生成的产物、产率及比例用TLC、HPLC进行检测。该方法的建立将为其他稀有糖及其衍生物的合成提供理论依据。
In this paper,the expression of glycerol kinase(GK) from Escherichia coli MG1655 and its application for ketose synthesis were investigated. The gene glpK encoding GK was amplified and cloned into the expression plasmid pET-28a. The recombinant plasmid was transformed into the E.coli Rosetta(DE3) to express the protein induced by IPTG. GK enzyme was purified by Ni2+ chelating affinity column chromatography. The GK enzyme can catalyze cheap substrate glycerol to produce L-glycerol 3-phosphate which is converted into DHAP by glycerol phosphate oxidase(GPO).The generated DHAP can be coupled with the acceptor D-glyceraldehyde catalyzed by different DHAP-dependent aldolases to produce ketose-1-phosphate,which can be dephosphorylated with acid phosphatase(AP) to get a series of ketoses. The results demonstrated that a series of ketoses including rare sugars were successfully synthesized using one-pot multienzymatic reaction with the cheap substrate glycerol as the precursor. The product yields and ratios were detected by TLC and HPLC. This approach could provide the theory basis for the synthesis of more other rare sugars and their derivatives
基于核酸分子杂交的免疫芯片抗体固定新方法
沙莎,殷赟,,黄庄荣,余挺,
分析化学 , 2013, DOI: 10.3724/SP.J.1096.2013.20667
Abstract: 基于核酸分子杂交原理构建了一种新型抗体固定方法。先将抗体与寡核苷酸单链交联,再将两者的复合物与固相载体表面上的互补寡核苷酸链结合,从而将抗体固定到载体的表面。在磁珠表面对该固定方法进行实验,证明了方法的可行性。以本方法构建了针对转基因BtCry1Ac蛋白的免疫芯片,用Cy3标记二抗对其探针固定效果进行分析,并且在芯片上对BtCry1Ac蛋白进行梯度浓度检测试验。结果表明,以本方法构建的抗体芯片,探针分布具有良好的特异性;探针层分布均匀,非特异吸附小;检测灵敏度达到0.01-0.05μg/L;此外,通过杂交核酸双链的解离成功实现了芯片的再生,有助于解决传统抗体固定方法中芯片不可再生的问题。
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