检索结果-南通市图书馆

Mass Spectrometric Evidence of Heparin Disaccharides for the Catalytic Characterization of A Novel Endolytic Heparinase

引用

Acta Biochimica et Biophysica Sinica 2004年第12期36卷 840-844页

作者： Yapeng CHAO1,3, Shaoxiang XIONG2, Xiulan CHENG1, and Shijun QIAN1* 1Institute of Microbiology, chinese academy of sciences, beijing 100080, china 2Center of Mass Spectrometry, Institute of Chemistry, chinese academy of sciences, beijing 100080, china 3graduate school of the chinese academy of sciences, beijing 100039, china Institute of Microbiology Chinese Academy of SciencesBeijing 100080 China graduate school of the chinese academy of sciencesbeijing 100039 China Center of Mass Spectrometry Institute of Chemistry Chinese Academy of SciencesBeijing 100080 China

Heparinase from different sources can eliminate heparin or/and heparan sulfate into various low-molecular weight heparins with different characteristics. Porcine intestinal mucosa heparin was de- graded into a series of oligosaccharides by a novel heparinase from the species Sphingobacterium. Disaccha- ride components from the digests were separated and purified by ultrafiltration and HPLC. Five major peaks appeared as three types according to their retention time. The mass spectrometry of peak I mainly gave the non-sulfated disaccharide with the mass of 379 Da. Peak II and III were indicated as two major monosulfated disaccharides with molecular mass of 417 and 459 Da respectively. Moreover, the peak III represented an N- acetyl disaccharide. Both peak IV and V showed the same mass of 496 Da, hinting that they were disulfate- substituted disaccharides. No trisulfate-substituted disaccharides were detected in the mixture of the heparin digest though they were abundant in the heparin structure. The results revealed that the heparinase might specifically cut the sites with low sulfated domain in heparin.

关键词： electrospray ionization-mass spectrometry heparin disaccharides heparinase high perfor- mance liquid chromatography Sphingobacterium sp.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Preliminary studies on differential defense responses induced during plant communication

引用

Cell Research 2005年第3期15卷 187-192页

作者： Jin Ying PENG1,3,Zhong Hai LI2,Hui XIANG1,3,Jian Hua HUANG1,3,Shi Hai JIA1,3,Xue Xia MIAO1,Yong Ping HUANG1* 1Institute of Plant Physiology and Ecology,Shanghai Institute for Biological sciences,graduate school of the chinese academy of sciences,chinese academy of sciences,300 Fenglin Road,Shanghai 200032,china 2chinese National Human Genome Center at Shanghai,250 Bibo Road,Shanghai 201203,china 3graduate school of the chinese academy of sciences,beijing 100039,china Institute of Plant Physiology and Ecology Shanghai Institute for Biological Sciences Graduate School of the Chinese Academy of Sciences Chinese Academy of Sciences Shanghai China graduate school of the chinese academy of sciences Beijing China chinese National Human Genome Center at Shanghai Shanghai China

We compared the expression patterns of three representative genes in undamaged tomato and tobacco plants in response to exposure to either tomato or tobacco fed on by Helicoverpa armigera (cotton bollworm). When tomato and tobacco, two species of one family, were incubated in the chambers with the tomato plants damaged by the cotton bollworm, the expression of the PR1, BGL2, and PAL genes was up-regulated in leaves of both plants. However, the levels of gene expression were significantly higher in the tomato than that in the tobacco. In addition, the activities of enzymes, peroxidase, polyphenol oxidase, and lipoxygenase were found to be higher in the tomato than those in the tobacco. Similar results were obtained when the damaged plants were replaced by the tobacco.

关键词： plant-plant communication tomato (Lycopersicon esculentum) tobacco (Nicotiana tabacum) cotton boll- worm (Helicoverpa armigera) inducible defenses.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

分子检测技术对活性污泥中氨氧化细菌的比较研究

引用

微生物学报 2003年第3期43卷 372-378页

作者：许玫英曾国驱任随周岑英华孙国萍郭俊广东省微生物研究所广州51007 中国科学院华南植物研究所

采用PCR扩增、随机克隆测序等技术 ,分析处理含高浓度氨氮的废水处理系统不同驯化时期的 4个活性污泥样品 ,对样品中氨氧化细菌 (AOB)的种类和氨单加氧酶 (AMO)的活性进行分析比较 ,并在国内首次采用PCR 变性梯度凝胶电泳 (DGGE)相结合... 详细信息

采用PCR扩增、随机克隆测序等技术 ,分析处理含高浓度氨氮的废水处理系统不同驯化时期的 4个活性污泥样品 ,对样品中氨氧化细菌 (AOB)的种类和氨单加氧酶 (AMO)的活性进行分析比较 ,并在国内首次采用PCR 变性梯度凝胶电泳 (DGGE)相结合的技术对样品中总的细菌类群的差异进行研究。结果表明所检测到的氨氧化细菌优势菌群均属于变形细菌的β亚类 ,与Nitrosomonassp .具有较高的相似性。活性污泥驯化成熟后 ,废水处理系统中AMO的活性有明显提高 ,活性污泥中的细菌类群更加集中 ,优势菌群相对稳定 ,系统对废水的处理效率也相应提高。结果表明采用分子检测技术有利于更全面地了解AOB的类群和功能 ,进而改善废水处理系统的处理效果。

关键词：分子检测技术活性污泥氨氧化细菌变性梯度凝胶电泳废水处理

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of cosmological constant on motion of UHECR particles

引用

Science china(Physics,Mechanics & Astronomy) 2005年第1期48卷 44-56页

作者： CHEN Shaoxia & CHANG Zhe Institute of High Energy Physics, chinese academy of sciences, beijing 100039, china graduate school of chinese academy of sciences, beijing 100039, china Institute of High Energy Physics Chinese Academy of Sciences Beijing 100039 China graduate school Chinese Academy of Sciences Beijing 100039 China

Recent astronomical observations manifest that about two-thirds of the whole energy in the Universe is contributed by a small positive cosmological constant A (> 0). Then, an asymptotically de Sitter spacetime is premised naturally. However, physics in the de Sitter spacetime is very different from that in the Minkowski spacetime. As the first step, a covariant formalism of the kinematics in the de Sitter spacetime is presented here. By solving exactly the equations of motion for a field, we obtain the dispersion relation of a free particle. It is noticed that the dispersion relation is dependent on the degree of freedom of angular momentum of the particle. We show the threshold anomaly of the ultra high energy cosmic ray disappears naturally in the framework of the de Sitter kinematics.

关键词： ultrahigh energy cosmic ray, cosmological constant, curved spacetime.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Recent advances in the data analysis method of functional magnetic resonance imaging and its applications in neuroimaging

引用

Progress in Natural Science:Materials International 2006年第8期16卷 785-795页

作者： TIAN Jie, YANG Lei and HU Jin (Institute of Automation, chinese academy of sciences, beijing 100080, china graduate school of chinese academy of sciences, beijing 100039, china) Institute of Automation Chinese Academy of Sciences Beijing 100080 China graduate school of chinese academy of sciences Beijing 100039 China

Functional magnetic resonance imaging (fMRI) has opened a new area to explore the human brain. The fMRI can reveal the deep insights of spatial and temporal changes underlying a broad range of brain function, such as motor, vision, memory and emotion, all of which are helpful in the clinical investigation. In this paper, we introduce some recent-developed algorithms for fMRI signal detection such as model-driven method (general linear model, deconvolution model, non-linear model, etc. ) and data-driven method (principle component analysis, independent component analysis, self-organization mapping, clustered constrained non-negative matrix factorization, etc. ). We also propose several important applications of neuroimaging and point out their shortcomings and future perspectives.

关键词： fMR1 data analysis neuroimaging.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Reconstruction of temperature series in china for the last 5000 years

引用

Progress in Natural Science:Materials International 2006年第8期16卷 838-845页

作者： GE Quansheng, WANG Shunbing and ZHENG Jingyun (Institute of Geographical sciences and Natural Resources Research, chinese academy of sciences, beijing 100101, china graduate school of the chinese academy of sciences, beijing 100039, china) Institute of Geographical sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China graduate school of the chinese academy of sciences Beijing 100039 China

A temperature series with a 100 year resolution for the last 5000 years in china has been reconstructed by using 31 longterm temperature proxy series selected from recent publications in the last 20 years. The proxy records include pollens, stalagmites, lake-sediments, peat, ice cores and historical documents. The result reveals that in the millennial scale temperature variation it was warm in 3050-250 BC and it was cold in 250 BC-1950 AD. In the above two periods there were many stages of sub-scale temperature fluctuations. The result also shows an obvious temperature discrepancy on the century to multi-century scale between the Eastern Monsoon Region, the Qinghai-Tibet Region and the Northwestern Region in 2850 BC, 2350 BC, 1350 BC, 950-350 BC, 50-250 AD, and 550 AD. A comparison between the reconstructed series of this paper and some North Hemisphere temperature series indicates that in the longterm scale change, the temperature change in china is in phrase with that of the Northern Hemisphere during the last 5000 years, while on the century to multi-century scale there are differences at the beginning and end times, which may imply that temperature change does not occur simultaneously in different regions.

关键词： temperature series the last 5000 years china.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Identification of novel SINEs from Cyprinidae and their evolutionary significance

引用

Progress in Natural Science:Materials International 2007年第3期17卷 270-279页

作者： HAN Yawei, HE Slumping and CHEN Yiyu ( Institute of Hydrobiology, chinese academy of sciences, Wuhan 430072, china. graduate school, chinese academy of sciences, beijing 100039, china) Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China graduate school Chinese Academy of Sciences Beijing 100039 China

Short interspersed nuclear elements (SINEs) are widespread among eukaryotic genomes. They are repetitive DNA sequences that have been amplified by retrotransposition. In this study, a class of SINEs were isolated from the Opsariichthys bidens genome, and named Opsar. Sequence analysis confirmed that Opsar is a new class of typical SINEs derived from tRNA molecules. With the tRNA-derived region of Opsar and through BLASTN search, we further identified Zb-SINEs from the zebrafish genome, which includes two groups: Zb-SINE-A and Zb-SINE-B. The Zb-SINE-A. group comprises subfamilies of -Al--A5, and the Zb-SINE-B group is a dimer of the tRNA -derived region and shares a similar dimeric composition to Alu. Zb-SINEs are composed of three distinct regions: a 5’ end tRNA-derived region, a tRNA-unrelated region and a 3’ end AT-rich region. The flanking regions are AT rich. The average length of Zb-SINEs elements is about 340 bp. Zb-SINEs account for as much as 0.1 % of the whole zebrafish genome. About 70% of the Zb-SINEs are on chromosomes 11, 18, and 19. These Zb-SINEs were characterized by PCR and dot hybridization. The distribution pattern of Zb-SINEs in genome strongly supports the master genes model. The tRNA-derived regions of Opsar and Zb-SINEs were compared with the tRNAAla gene, and they showed 76% similarity, indicating that Opsar and Zb-SINEs originated from an inactive tRNA sequence or a tRNA -like sequence. In view of the evolutionary status of zebrafish in the Cyprinidae, we deduced that Zb-SINEs were a very old class of interspersed sequences.

关键词： short interspersed nuclear elements (SINEs) master gene model Opsar Zb-SINEs and Cyprinidae.

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Twistor bundle theory and its application

引用

Science china Mathematics 2004年第4期47卷 605-616页

作者： PENG Chia-Kuei & TANG ZizhouDepartment of Mathematics, graduate school of chinese academy of sciences, beijing 100039, china Department of Mathematical sciences, Tsinghua University, beijing 100084, china Department of Mathematics Graduate School of Chinese Academy of Sciences Beijing China Department of Mathematical sciences Tsinghua University Beijing China

Over an oriented even dimensional Riemannian manifold(M 2m ,ds2 ), in terms of the Levi-Civita connection form Ω and the canonical form Θ on the bundle of positive orthonormal frames, we give a detailed description of the twistor bundle Гm = SO(2m)/U(m)? J +(@#@ M,ds2 ) →M. The integrability on an almost complex structureJ compatible with the metric and the orientation, is shown to be equivalent to the fact that the corresponding cross section of the twistor bundle is holomorphic with respect toJ and the canonical almost complex structureJ 1 onJ +(M,ds2 ), by using moving frame theory. Moreover, for various metrics and a fixed orientation onM, a canonical bundle isomorphism is established. As a consequence, we generalize a celebrated theorem of LeBrun.

关键词： almost complex structure, integrability, twistor bundle.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Isolation and Characterization of Photosystem Ⅱ of Porphyra yezoensis Ueda

引用

Acta Biochimica et Biophysica Sinica 2004年第11期36卷 780-785页

作者： Zheng-Quan GAO, Guang-Ce WANG, and Cheng-Kui TSENGKey Laboratory of Experimental Marine Biology, Institute of Oceanology, the chinese academy of sciences, Qingdao 266071, china graduate school, the chinese academy of sciences, beijing 100039, china Key Laboratory of Experimental Marine Biology Institute of Oceanology the Chinese Academy of SciencesQingdao 266071 China graduate school the Chinese Academy of SciencesBeijing 100039 China

The thylakoid membranes were isolated and purified from gametophyte of Porphyra yezoensis Ueda (P. yezoensis) by sucrose density gradient ultracentrifugation. After P. yezoensis gametophyte thylakoid membranes were so... 详细信息

关键词： red algae Porphyra yezoensis Ueda photosystem Ⅱ polypeptide composition extrinsic protein

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

An improved method for evaluating the seasonal variability of total suspended sediment flux field in the Yellow and East china Seas

引用

International Journal of Sediment Research 2011年第1期26卷 1-14页

作者： PANG Chongguang~1,YU Wei~2,YANG Yang~3,and HAN Danxiu~4 Institute of Oceanology,chinese academy of sciences,Qingdao 266071,china, 2 Institute of Oceanology,chinese academy of sciences,Qingdao 266071,china,graduate school of chinese academy of sciences,beijing 100039,china 3 Institute of Oceanology,chinese academy of sciences,Qingdao 266071,china,graduate school of chinese academy of sciences,beijing 100039,china 4 china University of Petroleum,beijing 102249,china Doctor Researcher Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China Graduate School of Chinese Academy of Sciences Beijing 100039 China china University of Petroleum Beijing 102249 China

The suspended sediment flux field in the Yellow and East china Seas(YECS) displays its seasonal variability.A new method is introduced in this paper to obtain the flux field via retrieval of ocean color remote sensing data,statistical analysis of historical suspended sediment concentration data,and numerical simulation of three-dimensional(3D) flow *** components of the sediment flux field include(i) surface suspended sediment concentration inverted from ocean color remote sensing data;(ii) vertical distribution of suspended sediment concentration obtained by statistical analysis of historical observation data;and(iii) 3D flow field modeled by a numerical *** the improved method,the 3D suspended sediment flux field in the YECS has been *** comparison with the suspended sediment flux field solely based on the numerical simulation of a suspended sediment transport model,the suspended sediment flux field obtained by the improved method is found to be more *** 3D suspended sediment flux field from ocean colour remote sensing and in situ observation are more closer to the ***,by quantitatively analyzing the newly obtained suspended sediment flux field,the quantity of sediment erosion and deposition within the different regions can be *** sediment exchange between the Yellow Sea and the East china Sea can be *** mechanism of suspended sediment transport in the YECS can be better *** particular,it is suggested that the long-term transport of suspended sediment is controlled mainly by the circulation pattern,especially the current in winter.

关键词： Suspended sediment flux field Seasonal variability Yellow and East china Seas Regression equation Numerical simulation

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：