Impacts of surface micro-topography on cellular biological responses

与常规的细胞体外培养器皿不同，细胞在体内生长时，其微环境并不是简单的平面形式，每一种组织都有其特定的三维微结构。这类具有微结构的微环境是细胞生长、分化的重要调控因子。近年关于基底微拓扑结构影响细胞生长、分化等行为研究的文献迅速增加，研究发现，具有微拓扑结构的基底可改变细胞的铺展、迁移、取向等行为，引导细胞骨架的重排，调控干细胞分化潜能，对于体外组织构建以及医学植入材料的表面处理具有指导性意义。本文就有关基底微拓扑结构影响细胞生物学研究的最新进展进行了综述

The Acetylation of Thymosin α1 is Independent on RimL in Escherichia coli

目的:考察大肠杆菌乙酰转移酶rIMl对胸腺素α1(Tα1)乙酰化修饰的影响。方法:构建含500bP同源臂的卡那抗性基因打靶片段,利用rEd同源重组系统,使大肠杆菌bl21(dE3)的rIMl基因插入失活,随后导入质粒PCP20去除抗性基因,构建突变菌株rIMl-bl21(dE3);将重组质粒PET-Tα1-l12分别转入出发菌株和突变菌株中进行表达,经固定金属离子亲和层析和反向高效液相层析后,将所得纯品进行质谱分析,精确测定相对分子质量。结果:PCr鉴定结果证明成功敲除rIMl基因;质谱结果表明,rIMl基因敲除菌中所表达的Tα1-l12融合蛋白与出发菌株一样,均有部分乙酰化修饰。结论:Tα1的乙酰化修饰并不依赖于rIMl。Objective:To investigate the effect of RimL,a N-terminal acetyltransferase of E.coli,on thymosin α1(Tα1) acetylation.Methods:A kanamycin cassette with two 500 bp long arms homologous to the regions around rimL as the replacement fragment was electroporated into cells,in which the Red recombinant functions was induced.Subsequently,the plasmid pCP20 was transformed to eliminate the kanamycin resistant gene.The plasmid pET-Tα1-L12 was transformed into the original and mutant strains respectively.The expressed fusion protein Tα1-L12 was purified by IMAC and RP-HPLC.The accurate molecular weight of the fusion protein was measured by Q-Tof-MS.Results:The gene rimL was inactivated by insertion of the replacement fragment successfully.According to the MS results,the fusion protein Tα1-L12 was still partly acetylated when it was expressed in the mutant strains as in the original strains.Conclusion:Tα1 acetylation was independent on RimL

The Analysis and Assessment of Groundwater Quality of Qinhuangdao

针对秦皇岛市地下水位下降,环境污染日益严重的现实,开展了以海水入侵区为主的地下水质综合评价与分析。在全市境内布设76眼监测井,用单因子法和综合法对地下水质量进行了评价,并对地下水水质变化趋势进行了分析。研究结果表明:Ⅰ类水只占5.3%,Ⅱ、Ⅲ水占14.5%,Ⅳ类及超Ⅳ类水占到80%以上,其中Ⅴ类水占40%。主要污染物有Fe、Mn、NO3-N、Cl、总硬度等。地下水质监测动态变化显示:总硬度、Cl-、矿化度、F-等呈上升趋势,其中总硬度和Cl-上升达75%,说明海水入侵的影响很大。To conter the situation of increasingly declining groundwater level and environmental pollution,the water quality assessment and analysis of sea water invasion district was studied.76 monitoring wells were laid,a single index method and the method of the comprehensive evaluation were used and the groundwater trends was analyzed.The results showed that the shallow groundwater of Qinhuangdao City meeting the Ⅰcategory water standard accounted for only 5.3%,Ⅱ,Ⅲcategories 14.5%,Ⅳ,Ⅴcategories more than 80%,40% of which wasⅤcategories and that Fe,Mn,NO3-N,Cl,total hardness were the major chemical components.The dynamics monitoring of underground water indicated that total hardness,chlorine,degree of mineralization,fluorine are becoming upward trend,especially total hardness and chlorine increased by over 75%, which means salt water intrusion on the larger impact.河北省自然基金项目(301165

NMR Studies on Interactions between Diperoxovanadate and Imidazole-like Ligands

为探讨咪唑环上取代基团对反应平衡的影响,在模拟生理条件(0.15 mol·L~(-1)NaCl溶液)下,应用多核(~1H、~(13)C和~(51)V)、扩散排序谱(DOSY)以及变温NMR等谱学技术研究双过氧钒配合物NH_4[OV(O_2)_2{2-(2'-Pyri-dine)- [midazole}]·4H_2O(简写为bpV(Imi-Py))和咪唑类配体(咪唑、2-甲基-咪唑、4-甲基-咪唑和组氨酸)的相互作用,其从强到弱的顺序为咪唑≈4-甲基-咪唑>2-甲基-咪唑>组氨酸.研究结果表明,咪唑环上取代基团空间位阻对反应平衡产生较大影响,同时竞争配位的结果导致新的6配位过氧物种[OV(O_2)_2L]~-(L为咪唑类配体)的生成,当配体为4-甲基-咪唑和组氨酸时,生成的则是一对异构体.To understand the substituting effects of imidazole ring on the reaction equilibrium,the interactions between diperoxovanadate complex NH_4[OV(O_2)_2{2-(2'-Pyridine)-Imidazole}]·4H_2O (abbr.bpV(Imi-Py)) and a series of imidazole-like ligands (imidazole,2-methyl-imidazole,4-methyl-imidazole,and histidine) in solution were explored using multinuclear (~1H,~(13)C,and ~(51)V) magnetic resonance,diffusion ordered spectroscopy (DOSY),and variable temperature NMR in 0.15 mol·L~(-1) NaCl ionic medium for mimicking the physiological conditions.The experimental results indicated that the activities of bpV(Imi-Py) and organic ligands were as follows:imidazole≈4-methyl-imidazole>2-methyl- imidazole>histidine.The stedc effect of the organic ligands affects the reaction equilibrium.At the same time,new six- coordinated peroxovanadate species [OV(O_2)_2L]-(L=imidazole-like ligands) were formed due to the competitive coordination between 2-(2'-pyridyl)-imidazole and the imidazole-like ligands.When the ligand was 4-methyl- imidazole or histidine,a pair of isomers was formed.国家自然科学基金(20772027);; 973子课题(2003CB716005);; 湖南省自然科学基金(06JJ30004);; 中国博士后科学基金(20070410805);; 湖南省教育厅青年项目(068028);; 卫生部(福建省)卫生教育联合攻关计划(3502220051027);; 厦门市重大疾病攻关研究基金(Wkj2005-2-019);; 固体表面物理化学国家重点实验室开放基金和湖南科技大学博士基金(E55107)资

基底力学微环境对干细胞生物学功能的影响

目的:干细胞是一类没有分化的多潜能细胞,具有无限自我增殖和分化成多种细胞的能力。干细胞生长的生理微环境称为壁龛(niche),基底硬度、拓扑结构和三维尺寸等物理力学特征决定干细胞的命运。尽管越来越多的证据证明基底力学微环境对干细胞干性及分化具有重要影响,但基底硬度、拓扑结构和三维尺寸单因素及多因素耦合如何影响干细胞的特性及其分子机制还不够清楚。方法:为模拟体内干细胞生长力学微环境,考察不同基

Differential regulation of stiffness, topography, and dimension of substrates in rat mesenchymal stem cells

The physiological microenvironment of the stem cell niche, including the three factors of stiffness, topography, and dimension, is crucial to stem cell proliferation and differentiation. Although a growing body of evidence is present to elucidate the importance of these factors individually, the interaction of the biophysical parameters of the factors remains insufficiently characterized, particularly for stem cells. To address this issue fully, we applied a micro-fabricated polyacrylamide hydrogel substrate with two elasticities, two topographies, and three dimensions to systematically test proliferation, morphology and spreading, differentiation, and cytoskeletal re-organization of rat bone marrow mesenchymal stem cells (rBMSCs) on twelve cases. An isolated but not combinatory impact of the factors was found regarding the specific functions. Substrate stiffness or dimension is predominant in regulating cell proliferation by fostering cell growth on stiff, unevenly dimensioned substrate. Topography is a key factor for manipulating cell morphology and spreading via the formation of a large spherical shape in a pillar substrate but not in a grooved substrate. Although stiffness leads to osteogenic or neuronal differentiation of rBMSCs on a stiff or soft substrate, respectively, topography or dimension also plays a lesser role in directing cell differentiation. Neither an isolated effect nor a combinatory effect was found for actin or tubulin expression, whereas a seemingly combinatory effect of topography and dimension was found in manipulating vimentin expression. These results further the understandings of stem cell proliferation, morphology, and differentiation in a physiologically mimicking microenvironment

中国物理海洋学研究70年：发展历程、学术成就概览

本文概略评述新中国成立70年来物理海洋学各分支研究领域的发展历程和若干学术成就。中国物理海洋学研究起步于海浪、潮汐、近海环流与水团,以及以风暴潮为主的海洋气象灾害的研究。随着国力的增强,研究领域不断拓展,涌现了大量具有广泛影响力的研究成果,其中包括:提出了被国际广泛采用的"普遍风浪谱"和"涌浪谱",发展了第三代海浪数值模式;提出了"准调和分析方法"和"潮汐潮流永久预报"等潮汐潮流的分析和预报方法;发现并命名了"棉兰老潜流",揭示了东海黑潮的多核结构及其多尺度变异机理等,系统描述了太平洋西边界流系;提出了印度尼西亚贯穿流的南海分支(或称南海贯穿流);不断完善了中国近海陆架环流系统,在南海环流、黑潮及其分支、台湾暖流、闽浙沿岸流、黄海冷水团环流、黄海暖流、渤海环流,以及陆架波方面均取得了深刻的认识;从大气桥和海洋桥两个方面对太平洋–印度洋–大西洋洋际相互作用进行了系统的总结;发展了浅海水团的研究方法,基本摸清了中国近海水团的分布和消长特征与机制,在大洋和极地水团分布及运动研究方面也做出了重要贡献;阐明了南海中尺度涡的宏观特征和生成机制,揭示了中尺度涡的三维结构,定量评估了其全球物质与能量输运能力;基本摸清了中国近海海洋锋的空间分布和季节变化特征,提出了地形、正压不稳定和斜压不稳定等锋面动力学机制;构建了"南海内波潜标观测网",实现了对内波生成–演变–消亡全过程机理的系统认识;发展了湍流的剪切不稳定理论,提出了海流"边缘不稳定"的概念,开发了海洋湍流模式,提出了湍流混合参数化的新方法等;在海洋内部混合机制和能量来源方面取得了新的认识,并阐述了混合对海洋深层环流、营养物质输运等过程的影响;研发了全球浪–潮–流耦合模式,推出一系列海洋与气候模式;发展了可同化主要海洋观测数据的海洋数据同化系统和用于ENSO预报的耦合同化系统;建立了达到国际水准的非地转(水槽/水池)和地转(旋转平台)物理模型实验平台;发展了ENSO预报的误差分析方法,建立了海洋和气候系统年代际变化的理论体系,揭示了中深层海洋对全球气候变化的响应;初步建成了中国近海海洋观测网;持续开展南北极调查研究;建立了台风、风暴潮、巨浪和海啸的业务化预报系统,为中国气象减灾提供保障;突破了国外的海洋技术封锁,研发了万米水深的深水水听器和海洋光学特性系列测量仪器;建立了溢油、危险化学品漂移扩散等预测模型,为伴随海洋资源开发所带来的风险事故的应急处理和预警预报提供科学支撑。文中引用的大量学术成果文献(每位第一作者优选不超过3篇)显示,经过70年的发展,中国物理海洋学研究培养了一支实力雄厚的科研队伍,这是最宝贵的成果。这支队伍必将成为中国物理海洋学研究攀登新高峰的主力军

Fluid flow-induced calcium response in early or late differentiated osteoclasts

Intracellular calcium oscillation caused by receptor activator of nuclear factor kappa-B ligand has been demonstrated to promote the differentiation of osteoclasts. Osteoclasts are recruited on the surface of trabeculae, and are exposed to fluid flow caused by the deformation of the bone matrix. However, the roles of fluid shear stress (FSS) on calcium response during the differentiation process of osteoclasts are still unknown. In the current study, the formation of tartrate-resistant acid phosphatase-positive, multinucleated osteoclasts from RAW264.7 macrophage cells were induced by co-culturing them with the conditioned medium from MC3T3-E1 osteoblasts. The in situ observations showed a high correlation between the area and the nuclear number of osteoclasts. The cells were stimulated by FSS at different levels (1 or 10 dyne/cm(2)) before (0 day) or after being induced for 4 or 8 days. The mechanically-induced calcium response was recorded and analyzed. The results indicated a different property of calcium oscillation for the osteoclasts in different fusion stages (i.e., more calcium-responsive peaks appeared in small osteoclasts than those in the larger ones). The rates of calcium influx decreased and the time of recovery in osteoclast cytosol increased along with the fusion of osteoclasts. In addition, increasing the FSS level enhanced the calcium oscillation of osteoclasts at early induction (4 days). However, this effect was weakened at the late induction (8 days). The present work could help provide understanding regarding the mechanism of the involvement of calcium in mechanically induced bone remodeling

微模式化基底上大鼠骨髓间充质干细胞的增殖、分化和迁移

目的利用微模式化基底研究基底几何微结构对骨髓间充质干细胞增殖、分化及迁移过程的影响。方法设计制作微模式化基底,用以控制细胞的铺展形态和面积。比较不同模式控制下大鼠骨髓间充质干细胞的增殖、分化和迁移数据。结果细胞铺展宽度狭小可抑制骨髓间充质干细胞的增殖,细胞铺展形状可以调节其向成骨细胞分化的进程,细胞铺展面积受限时迁移增强,其增殖迁移行为减弱与成骨细胞诱导因子地塞米松的作用有关。结论细胞铺展的几何形状和面积是骨髓间充质干细胞增殖、分化及迁移过程中的重要调节因子

Proliferation, differentiation, and migration of rat bone marrow mesenchymal stem cells on micropatterned substrate

目的 利用微模式化基底研究基底几何微结构对骨髓间充质干细胞增殖、分化及迁移过程的影响.方法 设计制作微模式化基底,用以控制细胞的铺展形态和面积.比较不同模式控制下大鼠骨髓间充质干细胞的增殖、分化和迁移数据.结果 细胞铺展宽度狭小可抑制骨髓间充质干细胞的增殖,细胞铺展形状可以调节其向成骨细胞分化的进程,细胞铺展面积受限时迁移增强,其增殖迁移行为减弱与成骨细胞诱导因子地塞米松的作用有关.结论 细胞铺展的几何形状和面积是骨髓间充质干细胞增殖、分化及迁移过程中的重要调节因子