拟穴青蟹抗菌肽Crustin新变体的表达特性与抗菌功能

Crustins是一类较早发现并广泛分布在甲壳动物中且富含半胱氨酸的阳离子抗菌肽,能够参与抗细菌的免疫应答。从拟穴青蟹（Scylla paramamosain）中克隆获得Crustin基因,命名为SpCrus1a,其cDNA序列全长744 bp,开放阅读框编码113个氨基酸,成熟肽分子量10.03 kDa,等电点8.30。表达分析结果发现其转录本主要存在于鳃、卵巢、上皮组织中,脂多糖刺激后SpCrus1a会上调表达。体外合成SpCrus1a的第29～47位氨基酸进行抗菌活性实验发现,其对革兰氏阳性菌具有较强的抗菌活性,对被测的革兰氏阴性菌抗菌活性较弱或无抗菌活性。合成肽Sp Crus1a29-47能够在较短时间内杀死绝大多数的金黄色葡萄球菌,2 h内杀死全部的金黄色葡萄球菌。扫描电镜发现合成肽Sp Crus1a29-47可造成金黄色葡萄球菌表面结构崎岖不平,高浓度Sp Crus1a29-47造成细菌的大量死亡。上述结果表明,SpCrus1a是抗菌肽Crustins的新变体。国家自然科学基金(U205123,31172438);;厦门南方海洋研究中心科技项目(14PYY050SF03

自适应光学对大气扰动波前的补偿效果研究：II.水平大气传输时…

讨论了光波在水平大气湍流中传输时的情况。计算结果表明自适应光学系统的补偿效果与光波传播路径上的横向风有很大的关系。大气湍流的强度越大, 自适应光学系统的截止频率越高, 横向风的影响也越大。计算结果还表明在相同的r0 或者相同的大气湍流强度下, 球面波所受大气扰动的自适应光学补偿效果受横向风的影响要比平面波的厉害。本文还将理论分析的结果和数值模拟的结果进行了比较, 表明数值模拟结果受横向风的影响比理论分析结果受横向风的影响大。最后, 文中分析了以上现象并对此作出了合理的解释

Spatiotemporal Changes of Farming-Pastoral Ecotone in Northern China, 1954–2005: A Case Study in Zhenlai County, Jilin Province

Analyzing spatiotemporal changes in land use and land cover could provide basic information for appropriate decision-making and thereby plays an essential role in promoting the sustainable use of land resources, especially in ecologically fragile regions. In this paper, a case study was taken in Zhenlai County, which is a part of the farming-pastoral ecotone of Northern China. This study integrated methods of bitemporal change detection and temporal trajectory analysis to trace the paths of land cover change for every location in the study area from 1954 to 2005, using published land cover data based on topographic and environmental background maps and also remotely sensed images including Landsat MSS (Multispectral Scanner) and TM (Thematic Mapper). Meanwhile, the Lorenz curve and Gini coefficient derived from economic models were also used to study the land use structure changes to gain a better understanding of human impact on this fragile ecosystem. Results of bitemporal change detection showed that the most common land cover transition in the study area was an expansion of arable land at the expense of grassland and wetland. Plenty of grassland was converted to other unused land, indicating serious environmental degradation in Zhenlai County during the past decades. Trajectory analysis of land use and land cover change demonstrated that settlement, arable land, and water bodies were relatively stable in terms of coverage and spatial distribution, while grassland, wetland, and forest land had weak stability. Natural forces were still dominating the environmental processes of the study area, while human-induced changes also played an important role in environmental change. In addition, different types of land use displayed different concentration trends and had large changes during the study period. Arable land was the most decentralized, whereas forest land was the most concentrated. The above results not only revealed notable spatiotemporal features of land use and land cover change in the time series, but also confirmed the applicability and effectiveness of the methodology in our research, which combined bitemporal change detection, temporal trajectory analysis, and a Lorenz curve/Gini coefficient in analyzing spatiotemporal changes in land use and land cover

胸腺肽类药物对体外诱导ES细胞分化为T细胞的作用

【目的】研究目前临床常用的增强细胞免疫功能的胸腺肽，胸腺5肽和胸腺素α-1在小鼠胚胎干细胞向T淋巴细胞分化过程中的作用。【方法】借助小鼠胚胎干细胞（ESC）体外自然分化形成的类胚体（EB）中含有三胚层细胞的独特细胞环境，加入多种细胞因子和胸腺多肽，体外诱导小鼠ESC向T淋巴细胞分化。利用流式细胞仪检测在三种不同胸腺多肽的诱导下．不同时间点的小鼠ESC来源的细胞表面CD3分子的表达水平。并在相应时间点通过RT—PCR检测与T淋巴细胞发育密切相关的Notch信号分子的转录水平。【结果】在加入胸腺肽和胸腺素α1诱导的实验组，均有细胞表达CD3分子，CD3^＋细胞的百分比随诱导时间的增加而增多；而加入胸腺五肽的实验组无CD3^＋细胞出现。加入胸腺素α1和胸腺肽的实验组．有Notchl及其配体delta-like-1和delta—like-4的转录；而加入胸腺五肽的实验组的细胞无Notch1及其配体转录。【结论】胸腺素α1或胸腺肽可能通过影响Notchl信号途径支持ES细胞向T细胞分化，而胸腺五肽无此作用

利用加设钢支撑改变单跨框架结构体系的抗震加固效果研究

单跨框架结构大量存在于中小学建筑中,中小学建筑已提高到乙类设防,根据抗震鉴定标准GB50023-2009,框架结构不宜为单跨框架;乙类设防时,不应为单跨框架。单跨框架是一种抗震严重不利体系,缺乏冗余约束,易发生整体倒塌。若从构件加固层次提高建筑的抗震性能,不但造价高、施工复杂,而且效果也不明显。加设支撑是一种改变建筑结构体系的方法,本文结合工程实例,讨论了加设钢支撑后原结构性能变化以及加固过程中应该注意的问题。研究表明,利用支撑改变结构受力体系,可以明显改善结构性能,提高抗震能力

试论上市公司高管薪酬的粘性——基于我国金融业上市公司的研究视角

本文以中国股票市场中金融业上市公司为样本,对高层管理人员薪酬粘性问题展开研究。研究发现,高管薪酬存在粘性,即在公司绩效上升时高管薪酬增加幅度显著高于公司绩效下降时的减少幅度。进一步研究还发现,公司规模、股权安排、负债比例等一系列特征对高管薪酬粘性具有显著的影响关系。本文研究不仅揭示我国上市公司高管薪酬变动特征,同时也为学术界进一步研究高管薪酬粘性问题提供理论基础与数据支持

NMR Studies on Interactions between Diperoxovanadate Complex and 3-Substituted Pyridines

为探讨有机配体上取代基团对反应平衡的影响,在模拟生理条件下(0.15mol/LNaCl溶液),应用多核(1H、13C和51V)多维(DOSY)以及变温NMR技术研究双过氧钒配合物[OV(O2)2(D2O)]-/[OV(O2)2(HOD)]-(简写为dpV)与3-取代吡啶的相互作用,并首次报道了一些物种的NMR化学位移.dpV与有机配体的反应性从强到弱的顺序为:吡啶>烟酸根>烟酸甲酰胺≈烟酸甲酯,这说明吡啶环上取代基影响反应平衡.竞争配位导致一系列新的6配位的过氧钒物种生成.密度泛函计算结果合理地解释了实验结果,并表明溶剂化效应在反应中起重要作用.To understand the substituting group effects of organic ligands on the reaction equilibrium, the interactions between a diperoxovanadate complex [OV(O2)2(D2O)]-/[OV(O2)2(HOD)]- (abbr. dpV) and a series of 3-substituted pyridines in solution were explored using multinuclear (1H, 13C, and 51V) magnetic resonance, DOSY, and variable temperature NMR in 0.15 mol/L NaCl ionic medium for mimicking the physiological condition. Some direct NMR data were given for the first time. The reactivity among the 3-substituted pyridines towards dpV takes the order of pyridine>nicotinate>N-methyl nicotinamide≈ methyl nicotinate. The competitive coordination results in the formation of a series of new six-coordinated peroxovanadate species [OV(O2)2L]n- (L=3-substituted pyridines, n=1 or 2). The results of density func-tional calculations provided a reasonable explanation of the relative reactivity of the 3-substituted pyridines. Solvation effects play an important role in these reactions.国家自然科学基金(Nos.20772027,20803020);; 973子课题(No.2003CB716005);; 湖南省自然科学基金(No.06JJ30004);; 中国博士后科学基金(No.20070410805);; 湖南省教育厅青年项目(No.06B028);; 固体表面物理化学国家重点实验室资助项目;; 湖南科技大学博士基金(No.E-55107)资助项

NMR and Theoretical Study on Interactions between Diperoxovanadate Complex and Substituted Pyridines

为探讨有机配体上取代基团对反应平衡的影响,在模拟生理条件下(0.15mol/L NaCl溶液),应用多核(1H,13C和51V)多维(DOSY)以及变温NMR技术研究双过氧钒配合物[OV(O2)2(D2O)]-/[OV(O2)2(HOD)]-(简写为bpV)与取代吡啶的相互作用.bpV与有机配体的反应性从强到弱的顺序为:皮考林酸根>异烟酸根>异烟酸甲酯>皮考林甲酯,这说明吡啶环上同一位置上的不同取代基团和同一取代基团在不同位置上都影响反应平衡,竞争配位导致一系列新的6配位(配体为异烟酸根和异烟酸甲酯)或7配位(配体为皮考林酸根和皮考林甲酯)的过氧钒物种[OV(O2)2L]n-(L=取代吡啶,n=1或2)生成,密度泛函计算结果较合理地解释了实验结果,并表明溶剂化在反应中起重要作用.To understand the substitution group effects of organic ligands on the reaction equilibrium,the interactions between diperoxovanadate complex [OV(O2)2(D2O)]-/[OV(O2)2(HOD)]-(abbr. bpV) and a series of substituted pyridines were explored using multinuclear(1H,13C,and 51V) magnetic resonance,DOSY,and variable temperature NMR in 0.15 mol/L NaCl ionic medium for mimicking the physiological condition. The reactivity order among the substituted pyridines and bpV is picolinate>isonicotinate> methyl isonicotinate>methyl picolinate. The competitive coordination results in the formation of a series of new six-coordinated(isonicotinate and methyl isonicotinate) or seven-coordinated(picolinate and methyl picolinate) peroxovanadate species [OV(O2)2L]n-(L=substituted pyridines,n=1 or 2). Both the different substitution groups at the same position and the same groups at the different substitution position affect these reactions. The results of density functional calculations provide someway a reasonable explanation for the relative reactivity of the substituted pyridines. Solvation effects play an important role in these reactions.国家自然科学基金(Nos.20772027,20803020);; 973子课题(No.2003CB716005);; 湖南省自然科学基金(No.06JJ30004);; 中国博士后科学基金(No.20070410805);; 湖南省教育厅青年项目(No.06B028);; 固体表面物理化学国家重点实验室资助项目;; 湖南科技大学博士基金(No.E-55107)资助项目

Purification and Properties of Soluble Hydrogenase from Photosynthetic Bacterium Chromatium vinosum

联系人: 龙敏南, 男, 1965 年1 月生, 博士, 副教授 T el : 0592-2186392 E-mail : longmn@ jin gxian. xmu. edu. cn光合细菌 Chromatium vinosum可溶性氢酶经 4次柱层析 (Whatman DE- 52 ,TSK- DEAE,Ultragel Ac A- 44 ,Mono Q)分离提纯后被纯化 630倍 ,得率为 33.5% .可溶性氢酶催化放氢比活性为 7.5μmol· min-1· mg-1.SDS- PAGE结果显示 ,可溶性氢酶由 52 k D和 2 1 .5k D两个亚基组成 .大亚基 N端氨基酸序列为 :SRTITIEPVTRXEGHAR;小亚基 N端氨基酸序列为 :STQPKIT-VATXLDG.氧化态可溶性氢酶在 54K时产生了典型的 Ni( )电子顺磁共振 (EPR)信号 (gxyz=2 .37、2 .1 6、2 .0 1 6和 gxyz=2 .30、2 .2 3、2 .0 1 6) .研究结果表明 ,C.vinosum可溶性氢酶是一种新的催化放氢的 Ni Fe-氢酶 .教育部重点科技项目!资助 (No.990 70

化学模拟生物固氮——Ⅸ 铁钼辅基模型化合物的合成和性能表征

本文曾在全国化学摸拟生物固氮协作组领导小组扩大会议(昆明,1980,8)上宣读。[中文文摘]采用乙二醇基阴离子作为活插头(可通过水解除去的双配位螯形配位体),对前文提出的合成方法作了重要改进,以期所合成的铁钼辅基模型化合物中Mo~(Ⅳ(Ⅲ))第一配位界内两个不稳定的配位体处于相邻的位置,如厦门模型Ⅲ(或厦门模型Ⅱ)所要求。合成和重组活性评价结果,重组活性比使用乙腈等为活插头的提高2个数量级,化学催化活性和选择性接近于天然FeMo-co水平。[英文文摘]A significant improvement has been made to the method previously proposed[3] for synthesizing FeMo-co modeling compounds. With the use of ethylene glycolate anion as labilizable blocking agent (hydrolyzable bidentatc chelating ligand)to protect two neighboring coordination sites in the first coordination sphere of MoIV(III) of the synthesized FeMo-co modeling compound, an increase in reconstituted-nitrogenase activity of 2 orders of magnitude of the sample synthesized (as compared with the use of acetoni-trile or other monodentare ligands as bloeking agents)has been obtained.Catalytic activity and selectivity assays as well as preliminary characterization by EPR method have also been made