Sequence analysis and prokaryotic expression system construction of PIA genes isolated from Neisseria gonorrhoeae

AIM: To analyze the nucleotide and putative amino acid sequences of PIA genes isolated from N.gonorrhoeae and to construct the prokaryotic expression system of PIA gene.METHODS: The entire PIA genes from 9 strains of N.gonorrhoeae were amplified by using high fidelity PCR.The target amplification fragments were sequenced after T-A cloning.Homology comparison of the nucleotide and putative amino acid sequences of PIA genes from the isolates with the reported sequences in GenBank was then performed.A prokaryotic expression system of PIA gene was constructed.Different dosages of IPTG were applied to induce the expression of the target recombinant protein (rPIA) and 10% SDS-PAGE plus Bio-Rad Agarose Image Analysor was used to determine the expression level of rPIA.rPIA was extracted using Ni-NTA affinity chromatography and the purified effect was detected by SDS-PAGE.RESULTS: In comparison with the reported PIA gene sequences (GenBank No: L19962),the homologies of nucleotide and putative amino acid sequences of PIA genes from the isolates were 99.6%-100% and 99.1%-100%,respectively,which indicated that all the isolates were belonging to serovars IA6.Output of rPIA was as high as 50.1% of the total bacterial proteins.The purified rPIA only showed a single target protein fragment in gel.CONCLUSION: Serovar IA6 is dominant in the local N.gonorrhoeae isolates and sequences of the encoding gene are relatively conserved.The constructed prokaryotic expression system is able to express rPIA with high efficiency,which may lay a foundation for further development of serological detection kit and vaccine of N.gonorrhoeae.     

α-萘乙酸对樱桃番茄扦插繁殖生根的影响

以樱桃番茄幼嫩侧枝为插穗,采用不同浓度的α-萘乙酸、不同育苗基质进行扦插试验.结果表明:在侧枝营养液生根试验中,以0.08mg/L处理的效果最好,平均生根数达68.5条;在侧枝苗床扦插试验中,以0.50 mg/L处理的效果好,平均生根数达44.5条;营养液生根优于苗床扦插生根效果.     

生长调节剂对黄绿蜜环菌菌丝生长的影响

选用三十烷醇(triacontanol)和肌醇(inositol)两种生长调节剂对黄绿蜜环菌(Armillaria luteo-virens)菌丝生长的影响进行研究。结果表明:三十烷醇和肌醇对菌丝生长都有较明显的影响,但肌醇效果不如三十烷醇。在培养基中添加1.5ⅹ10-7mg.mL-1三十烷醇,可明显提高菌丝生长速度,缩短培养周期。     

中国牡丹切花保鲜研究进展

对近20年来中国牡丹切花保鲜方面的最新研究进行了综述,以期为正在和将要从事牡丹切花保鲜研究的人们提供参考.我国的牡丹切花保鲜研究的对象多为中原牡丹品种群的品种,研究问题主要涉及乙烯、水分、保鲜剂等方面,关于分子水平上牡丹切花保鲜机理的研究未见报道.牡丹切花保鲜方面还有不少问题亟待开展或进行深入研究.     

草地植被盖度的近距离遥感测定

盖度或者覆盖度是植物群落结构的一个重要数量指标。通常的目视估测植物群落盖度方法不仅精度低,而且因人而异。本研究采用近距离遥感方法测定草地植物群落盖度,该方法主要包括数据获取、图像处理、像元数量提取和盖度计算4个部分。精度评价表明,该方法测定的绿色植被盖度误差很小,与目视估测方法比较,它具有客观、一致和精度高的优点。     

Study on bone marrow angiogenic mediators and inhibitors in aplastic anemia

AIM: Through detecting bone marrow angiogenic mediators and inhibitors in aplastic anemia (AA) patients,the value of angionesis in AA pathogenesis was elucidated.METHODS: The patients were divided into severe AA group (SAA,8 patients),non severe AA group (NSAA,10 patients),and normal control group (7 persons),5 patients were observed before treating (group beginning) and getting improvement (group improving).The angiogenic mediators vascular endothelial growth factor (VEGF) and bFGF were detected by ELISA,angiogenic inhibitors IFN-γ and TSP were detected by ELISA and flow cytometry,respectively.RESULTS: The levels of VEGF were lower in SAA group and NSAA group than those in control group significantly (P<0.05),the levels of IFN-γ and TSP were higher than those in control group (P<0.05),especially in SAA group (P<0.01).Compared with group beginning,the level of VEGF was higher in group improving (P<0.05),the levels of IFN-γ,TSP were lower (P<0.05),there was no obviously difference between group beginning and group improving except IFN-γ.CONCLUSION: The dropping of angiogenic mediators and the rising of angiogenic inhibitors may be one reason of reducing the number of microvessel,which result in deficiency in supporting hemapoietic stem cells by bone marrow microenvironment.     

晋西黄土丘陵边缘土石山区天然次生林群落β多样性研究

对晋西黄土丘陵边缘土石山区不同海拔高度木本植物物种丰富度以及各群落间β多样性特征进行了分析.结果表明,木本植物总物种丰富度随海拔高度的升高呈下降趋势,乔木种在海拔较高地段丰富度较大,灌木种则是在海拔较低地段丰富度较大.群落相异性指数Cody指数和Whittaker 指数多以相邻海拔群落间的指数值最小,群落间海拔差异越大指数值越大.而群落相似性指数Jaccard和Sorenson指数则表现出相反的变化规律,即随着群落间海拔差距的增大,指数值呈逐渐减小的趋势,相邻群落间的群落相似性指数值最大.     

秦岭南麓贫困山区经济与生态“双赢”互动模式研究

秦岭南麓贫困山区商南县自1999年实施退耕还林(草)工程以来,森林覆盖率达到52.7%,增加了1.5个百分点,林草覆盖率增加了4.6个百分点,但经济增长速度始终比较缓慢。为进一步了解退耕还林(草)工程对农村经济及退耕户带来的受益情况,以实地抽样调研为依据,通过对该县生态建设基本情况的深入调查,在初步掌握调查户普遍反映的主要问题基础上,依据该地区实际情况,提出了商南县生态与经济“双赢”互动模式,并对生态与经济互动途径提出了相关建议。     

基于气温、降水变化的南疆气候变化分析

近年来新疆气候尤其是南疆气候出现了一些引人注目的变化。本文采用南疆10个站点1955~2000年的气温和降水资料进行了研究,分别分析了南疆近50年来气温和降水的年际变化、季节变化,并对其进行了异常性分析。研究表明:在这45年里南疆气候已呈现出较明显的变暖变湿趋势。