一种简单实用的浮子式钢带液位测量装置

本文介绍一种简单实用的液位测量装置．提出了设计方案，对变送器、显示仪表主要电路进行了原理分析     

职业院校图书馆管理与创新的思考

高校的合并与联合办学，给职业院校图书馆的生存与发展带来了一定的压力和挑战。面对挑战，各职业院校的图书馆只有从管理、形象、观念、服务等方面不断创新，才能增强自身的能力，不断发展。     

锥虫长期超低温保藏方法的研究

作者观测不同保护剂、稀释液、ＰＨ值、降温方法、复苏温度、冻融次数、液相气相交替以及解冻后在普通冰瓶中存放时间对伊氏锥虫浙江虫浙江虫株的感染性及致病力的影响。在此试验基础上，又对伊氏锥虫的６个不同虫株、媾疫锥虫、铡果锥虫、布氏锥虫等４个种的９个早株，进行了超低温保藏试验和长期保藏效果观察。已测定的有效保藏期伊氏锥虫达５７４－３２００天，媾疫锥虫达２８６６天，则果锥虫达７６３天，布氏锥虫７８３天。通过     

肉鸡血清肌钙蛋白T与腹水综合征的关系研究

本试验建立了肉鸡血清中心源性肌钙蛋白T(Tn-T)的ELISA测定方法,用于对肉鸡腹水综合征的早期非损伤性诊断指标.结果表明,患腹水综合征肉鸡的血清Tn-T平均测定值为0.242±0.0703 ng/ml,而正常鸡的平均值为0.1 79±0.0467 ng/ml;以血清肌钙蛋白T测定值大于等于0.2 ng/ml作为判定肉鸡腹水综合征的标准,判别准确性达到78%.检测血液中肌钙蛋白T是诊断幼龄鸡早期心脏病的重要方法,可作为一种非损伤性方法用于针对肉鸡腹水综合征的育种方案中.     

CAD系统中的汉字处理技术

In this paper, a method of vector chinese character font definition and vector chinese character font library organization is discussed in detail. The paper also describes a commonly used CCP technique for CAD systems in personal computers and working sta     

草菇基因文库的构建(英文)

应用基因重细技术,我们建立丁一个草菇总DNA的部分基因文库。通过限制性内切酶Sau 3AI部分酶切纯化的草菇总DNA,得到小于4kb的DNA片段。这些DNA片段插入到经Bam HI酶切及碱性磷酶酯酶处理的pUC18质粒,转化感受态细胞DH5α。在此研究中。我们比较了两种转化方法(氯化钙转化法和电转化法)的转化效率,电转化法的转化效率高于氯化钙转化法数千倍,达到2×10(2)CFU/μg DNA。在此实验中DNA重组率是64%,这个草菇总DNA的部分基因文库由8000个克隆组成,平均每个克隆含有1.5kb的草菇DNA。此基因文库含有15%的草菇总DNA。可作为分子标记用于DNA指纹图谱分析及作为遗传学标记用于RFLPs的遗传图谱分析。     

机械制图试题库建设初探

根据机械制图课程的性质，任务和教学实践，提出了机械图试题库的题型，命题依据，试卷结构及试题来源。     

Sexual mating preferences in vitro and in planta among Japanese isolates of Phytophthora infestans

The sexual preferences of Japanese isolates of Phytophthora infestans were determined by mating on agar, in broth, or in plants. The influence of their sexual preference was confirmed in the host tissues. Three wild-type isolates and a -glucuronidase (GUS) transformant were co-cultured to identify the origin of antheridia and oogonia. Japanese A1 isolate had a unique sexual preference compared with foreign isolates. It produced self-fertile oospores with about 40% of total gametangia but tended to form antheridia on V-8 agar medium. In addition, oospores were formed in plants, but their sexual preference could not be reflected in vitro.     

Molecular Cloning and Expression of IL2 cDNA from the Tibet Pig

Interleukin-2 is a vital cytokine secreted by activated T lymphocytes, and plays important role in the regulation of cellular and humoral immunity of animals. In our experiment, IL2 cDNA of the Tibet Pig was first cloned by RT-PCR from ConA-stimulated lymphocytes in the blood and subcloned into pMD-18 T vector, which then was identified with endonuclease restriction. The sequencing result showed that Tibet pig IL-2 (TPIL-2) cDNA was 503 bp long (ORF was 465 bp) (Genbank accession number: AY 294018). The recombinant prokaryotic and eukaryotic expression plasmids of the cDNA were then constructed to analyse the ability to stimulate the proliferation of porcine lymphocytes in vitro. The recombinant porcine IL-2 expressed in the prokaryotic cells was found to be of 43 kDa molecular mass, which was consistent with a 17.4 kDa protein deduced from the IL-2 cDNA sequence (glutathione S-transferase molecular mass is 26 kDa); the recombinant protein in eukaryotic cells was confirmed by use of specific rabbit anti-porcine IL-2 serum in an ELISA. The bioactivity of TPIL-2 was detected through MTT colorimetry by stimulating the proliferation of pig ConA-stimulated blasts in vitro. The results indicate that the TPIL-2 significantly promoted the proliferation of ConA-stimulated blasts of pig. This confirms that IL-2 cDNA of the Tibet pig was successfully cloned and expressed in prokaryotic and eukaryotic cells, which lays the foundation for the the preparation of specific recombinant IL-2 protein and development of novel immune adjuvants to raise the immunity of pigs against various infectious pathogens and increase the immunoprotective efficacy of vaccines.     

Epitope identification and <Emphasis Type="Italic">in silico</Emphasis> prediction of the specificity of antibodies binding to the coat proteins of <Emphasis Type="Italic">Potato Virus Y</Emphasis> strains

A phage library containing 2.7 × 10⁹ randomly expressed peptides was used to determine the epitopes of three monoclonal antibodies that bind to the coat protein of potato virus Y. Construction of the consensus sequences for the peptides obtained after three selection rounds indicated that each antibody recognized a different epitope located within the first 50 N-terminal amino acids of the coat protein. The location of the epitopes was confirmed by heterologous expression of the N-terminal part of the coat protein in Escherichia coli, and, subsequently, by performing an immunological test with the three antibodies. The accuracy of the phage library was demonstrated by predicting in silico the cross-reactivity of the three antibodies with other potyvirus family members. ELISA and in silico predictions revealed the same results in almost every case. The potential of peptide phage libraries to optimize the use of antibodies in plant virology is discussed.