Preparation and application in electrochemistry of nanocrystalline CeO_2

Investigation on the synthetic structural and functional properties as well as applications of the nanomaterials has become a quite common subject that people focus on. CeO_2 is a cheap material extensively used in the areas of luminous materials, catalysts, electronic ceramics, etc. Cytochrome C is a metallic protein molecule (?)     

煤气脱硫工程工艺改造及运行小结

从脱硫工艺的改造、装置完善配套及日常管理等方面阐述了笔者对山西静乐煤焦化有限公司煤气脱硫工艺运行的一些体会。     

黄孢平革霉（Phanerochaete chrysosporium）木质素过氧化物酶基因的克隆与分析

用大肠杆菌克隆载体ｐＵＣ１０构建白腐丝状担子真菌黄孢平革霉（Ｐｈａｎｅｒｏｃｈａｅｔｅｃｈｒｙｓｏｓｐｏｒｉｕｍ）ＭＥ４４６基因组文库，用分离自ＢＫＭ－Ｆ１７６７菌株的木质素过氧化物酶ｃＤＮＡ片段ＣＬＧ４和ＣＬＧ５为探针，从构建的基因组文库中分离到一个含木质素过氧化物酶基因的重组子ｐＧＬＧ－Ｍ１。对该重组子插入片段所作的限制酶谱分析结果表明，它与来自ＢＫＭ－Ｆ１７６７的ＧＬＧ２片段的限制酶谱十分相似。     

Cloning, sequencing and expression analysis of cDNA encoding a constitutive heat shock protein 70 （HSC70） in Fenneropenaeus chinensis

The cDNA encoding hsc70 of Chinese shrimp Fenneropenaeus chinensis was cloned from hepatopancreas by RT-PCR based on its EST sequence. The full length cDNA of 2090 bp contained an open reading frame of 1956 nucleotides and partial 5‘- and 3‘-untranslated region(5‘- and 3‘-UTR). PCR amplification and sequencing analysis showed the existence of introns in the region of 1--547 bp, but they did not exist in the region of 548--2090 bp of hsc70 cDNA. When the deduced 652 amino acid sequence of HSC70 was compared with the members of HSP70 family from other organisms, the results showed 85.9% similarity with HSC71 from Oncorhynchus mykiss and HSC70 from Homo sapiens. It also exhibited 85.8% similarity with HSP70 from Mus musculu and 85.4% with HSC70 from Manduca sexta. Expression analysis showed that hsc70 mRNA was espressed constitutively in hepatopancreas, muscle, eyestalks, haemocytes, heart, ovary, intestine and gills in Fenneropenaeus chinensis. No difference could be detected on hsc70 mRNA level in muscle between heat-shocked and control animals.     

Upstream CRP-binding site is not essential for CRP-cAMP-mediated inhibition on the nifU promoter

When the NifA-mediated activation of Klebsiella pneumoniae nifU promoter is recreated in Escherichia coli, it has been observed that CRP-cAMP has an inhibitory effect on the nifU promoter. Sequence analysis indicates that there is a strong CRP-binding site located upstream of the nifU promoter, overlapping completely with a previously identified NifA-binding site. In vitro gel retardation analysis indicates that this putative CRP-binding site has similar affinity for CRP, when compared with that at the lac promoter, suggesting that CRP could effectively compete with NifA for such a binding site under physiological conditions. When this putative CRP-binding site on nifU was mutated, in vitro gel retardation analysis indicates that CRP can no longer bind to the mutant promoter. However, when constitutively expressed NifA is used as the activator, CRP-cAMP-mediated inhibitory effect on this mutant nifU promoter has no significant difference when compared with that obtained from its wild-type promoter. These results suggest that direct interaction between CRP and Eσ54, other than the DNA binding site(s) competition between CRP and NifA, plays the principal role in the CRP-cAMP-mediated inhibitory effect on nifU.     

水稻花粉Profilin基因启动子的克隆及序列分析

作者使用两次染色体步移（Genome walking)法，从灿稻（Oryza sativa subsp.indica)IR36中克隆到长度为569bp的花粉proiflin基因的启动子片段，并进行了全序列测定和分析。结果表明：在该段序列中含有3个TATA box，3个CAAT box和2个G－box。通过EPD（The Eukaryotic Promoter Database)的比较发现，序列的＋2－-71区域与番茄（Lycopersicon esculentum)花粉特异基因LAT52，向日葵（Helianthus annuus)花药特异基因SF2启动子关键序列的同源性为50％左右。     

Characterization and fine mapping of an early senescence mutant （es-t） in Oryza sativa L.

An es-t (early senescence-temporary) mutant, produced by ethylene methylsulfonate treatment of strain Nipponbare, was identified in rice. The leaves of es-t appeared yellow at the seedling stage, and had decreased chlorophyll content. Rust spots were found during growth in es-t, especially at the leaf margin and tip. The plants showed a typical early-senescence phenotype at the milky stage. The leaf surface of es-t appeared smoother than wild-type leaves under a scanning electron microscope, because the lea...     

半夏属植物凝集素基因片段克隆与序列分析

半夏属植物凝集素同其他天南星科植物凝集素一样,有3个甘露糖专一结合位点,且具显著的抗虫性.本研究根据已知掌叶半夏凝集素基因表达序列的相关信息设计引物,采用RT-PCR方法,分别从滴水珠、石蜘蛛、盾叶半夏、掌叶半夏、三叶半夏中克隆出长约530bp的凝集素基因片段.使用Genescan软件、ORF finder软件、Ex2PASy Proteomics Server软件对5个凝集素基因片段进行分析,结果表明:克隆出的滴水珠、石蜘蛛、盾叶半夏、掌叶半夏、三叶半夏凝集素基因片段分别编码107、171、170、170、170个氨基酸,在它们所编码的肽链中,都具有酪蛋白激酶II磷酸化位点、蛋白激酶C磷酸化位点和N-糖基化位点三类不同的功能位点.但由于编码序列碱基的突变,引起肽链中的氨基酸发生变化,从而导致这五种植株的凝集素基因存在较高的多态性以及存在功能位点的差异.其凝集素基因多态性及功能位点的差异对凝集素功能的影响需进一步分析.本实验为克隆五种植物凝集素基因的表达序列与结构基因以及深入研究半夏属凝集素的功能提供了有意义的参考资料.