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

在线全文

学校读者我要写书评

暂无评论

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,{2. 2.enter of mass spectrometry, institute of chemistry, chinese academy of sciences, Beijing 100080,{2. 3Graduate School of the chinese academy of sciences, Beijing 100039,{2. institute of Microbiology Chinese Academy of SciencesBeijing 100080 China Graduate School of the chinese academy of sciencesBeijing 100039 China Center of mass {2. 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.

血清(浆)类固醇激素液相色谱-串联质谱检测质量保证专家共识

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中华检验医学杂志 2024年第4期47卷 379-390页

作者：中国质谱学会临床质谱专家委员会蒋黎潘柏申王成彬中国质谱学会临床质谱专家委员会

液相色谱-串联质谱(LC-MS/MS)在人体血清(浆)类固醇激素检测中展现出优于传统免疫学方法的特异性高、分析测量范围宽、多标志物同时检测等特点, 已成为国际内分泌学领域相关疾病实验室诊断的首选方法。目前, 国内医学实验室开展血清(浆... 详细信息

液相色谱-串联质谱(LC-MS/MS)在人体血清(浆)类固醇激素检测中展现出优于传统免疫学方法的特异性高、分析测量范围宽、多标志物同时检测等特点, 已成为国际内分泌学领域相关疾病实验室诊断的首选方法。目前, 国内医学实验室开展血清(浆)类固醇激素LC-MS/MS检测多参考已发表学术论文和仪器厂家说明书提供的通用操作和检测程序。然而, 血清(浆)类固醇激素LC-MS/MS检测的技术难度大, 临床实验室检验人员大多数缺少质谱领域专业培训和实践经验, 而通用程序缺乏针对性和实操性, 尤其我国尚无针对该检测程序和质量保证的系统性文件, 导致实验室间检测结果存在较大差异, 阻碍了该技术的临床应用。为规范我国血清(浆)类固醇激素LC-MS/MS检测, 共识从检验前、中、后程序及其质量保证进行详细说明, 并提出针对性建议, 为实验室开展该检测项目提供参考, 以推动我国血清(浆)类固醇激素LC-MS/MS检测的临床应用和结果一致性。

关键词：液相色谱-质谱法类固醇激素标准化质量保证

High Throughput SNP Genotyping with Two Mini-sequencing Assays

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2004年第6期36卷 379-384页

作者： Chunqing LUO1,2., Libin DENG1#, and Changqing ZENG1,2. The institute of Genetic and Developmental Biology, the chinese academy of sciences, Beijing 100101,{2. 2.eijing Genomics institute, the chinese academy of sciences, Beijing 101300,{2. The institute of Genetic and Developmental Biology the Chinese Academy of SciencesBeijing 100101 China Beijing Genomics institute the Chinese Academy of SciencesBeijing 101300 China

Two mini-sequencing methods, FP-TDI (template-directed dye-terminator incorporation with fluorescence-polarization) and massArray (matrix assisted laser desorption ionization time of flight detection mass {2.), were optimized. A numeric standard was introduced to evaluate the SNP scoring quality of FP-TDI assay, thus made the optimization work easier. At the same time, using multi-PCR technology, 8-plex genotyping of massArray assay was successfully carried out, some softwares were developed and the data process of massArray was highly automated. Then these two methods were applied to high throughput SNP genotyping, the accuracy, efficiency and robustness were compared. The result shows FP-TDI is more sensitive to the concentration of SNPprimer and PCR product, as well as extension cycles, the SNPprimer length of FP-TDI should be 2.–30 bp long, whereas massArray assay prefers to be as short as only 16 *** 6440 SNP sites of human chromosome 3 were genotyped in a sample of 90 individuals, 4792.sites by FP-TDI assay and 1648 sites by massArray assay, the success rates of FP-TDI and massArray were 67.7% and 93.6% respectively. The throughput of massArray was higher than FP-TDI, and the cost of massArray was lower, massArray was more suitable for high throughput SNP genotyping.

关键词： SNP genotyping FP-TDI massArray high throughput

Numerical simulation of Meiyu front and the diagnosis of moist vorticity vector

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第11期17卷 1341-1347页

作者： Ping Fan1,2.and Luo Zhexian2.1. institute of Atmospheric Physics, chinese academy of sciences, Beijing 10002.,{2. 2. Nanjing University of Information sciences & Technology, Nanjing 2.0044,{2.) institute of Atmospheric Physics Chinese Acad. of Sci. Beijing 100029 China Nanjing University of Information sciences and Technology Nanjing 210044 China

Moist vorticity vector is introduced to study the development and evolution of mesoscale convective vortex (MCV) in the Meiyu front precipitation with the Advanced Regional Predication System (ARPS). In this study, the heavy rainfall is simulated to investigate the genesis, development and dissipation of middle scale convective vortex, which occurred from 0000 UTC 3 July to 12.0 UTC 5 July over the Jianghuai River valley. Moist vorticity vector (MVV) has zonal, radial and vertical components in its 3D spatial distribution. The simulation shows that the vertical component of moist vorticity vector well demonstrates the spatial distribution characteristics of middle scale convective vortex, especially in the process of Meiyu front precipitation. Diagnosis upon zonal, radial averaged and mass-integrated quantities of MVV shows that its vertical component and the surface precipitating ratio are in phase with a correlation coefficient of 0.68, indicating that the vertical component of MVV is closely associated with the Meiyu front precipitation. In addition, the tendency of the vertical component of MVV is mainly determined by the interaction between the vorticity and the zonal and radial gradient of condensational or depositional heating.

关键词： moist vorticity vector mesoscale convective vortex Meiyu front precipitation

Strengthening of the boreal winter Hadley circulation and its connection with ENSO

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第11期17卷 1327-1333页

作者： Ma Jie1,2.and Li Jianping2.1. College of Atmospheric sciences, Lanzhou University, Lanzhou 730000, china 2. LASG, {2. of Atmospheric Physics, chinese academy of sciences, Beijing 10002., china) College of Atmospheric sciences Lanzhou University Lanzhou 730000 China LASG Institute of Atmospheric Physics Chinese Acad. of Sci. Beijing 100029 China

Empirical orthogonal function (EOF) analysis is carried out for the year-to-year variability of the boreal winter (DJF) mass stream function of the mean meridional circulation (MMC) during the period 1948—2.05. The results demonstrate that it is dominated by the equatorially asymmetric and symmetric modes. Further analysis shows that the former mode is linked with the boreal winter Hadley cell mainly on the decadal time-scale, and the latter on the interannual time-scale. The asymmetric mode index (AMI) with a clear upward trend contributes to the decadal strengthening of the boreal Hadley circulation, and is closely correlated with the tropical SST warming, especially in the region of Indo-west Pacific warm pool (INWP). Furthermore, the AMI also contributes to the abrupt change of the correlation coefficient between the boreal Hadley circulation and ENSO after 1976. The symmetric mode index (SMI) with robust and stable linkage with ENSO shows a significant interannual variability, suggesting that the variability of the Hadley circulation is mainly associated with ENSO on the interannual time-scale.

关键词： the Hadley circulation interannual time-scale decadal time-scale

Explicit analytical solutions of the anisotropic Brinkman model for the natural convection in porous media(Ⅱ)

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(Physics,Mechanics & Astronomy) 2005年第4期48卷 422-430页

作者： CAI Ruixian1, GOU Chenhua1, 2.& ZHANG Na1 1. institute of Engineering Thermophysics, chinese academy of sciences, Beijing 100080,{2. 2. Graduate School, chinese academy of sciences, Beijing 100080,{2. institute of Engineering Thermophysics Chinese Academy of Sciences Beijing China Graduate School Chinese Academy of Sciences Beijing China

Some algebraically explicit analytical solutions are derived for the anisotropic Brinkman model―an improved Darcy model―describing the natural convection in porous media. Besides their important theoretical meaning (for example, in analyzing the non-Darcy and anisotropic effects on the convection), such analytical solutions can be the benchmark solutions that can promote the development of computational heat and mass transfer. Some solutions considering the anisotropic effect of permeability have been given previously by the authors, and this paper gives solutions including the anisotropic effect of thermal conductivity and the effect of heat sources.

关键词： explicit analytical solution, porous medium, natural convection, Brinkman model, anisotropic.

Study on the atmospheric photochemical reaction of CF_3 radicals using ultraviolet photoelectron and photoionization mass spectrometer

在线全文

学校读者我要写书评

暂无评论

Science china chemistry 2008年第4期51卷 316-321页

作者： YAO Li1,2. DU Lin1,2. YIN Shi1,2.& GE MaoFa1 1 Beijing National Laboratory for Molecular sciences (BNLMS), State Key Laboratory for Structural chemistry of Unstable and Stable Species,{2., chinese academy of sciences, Beijing 100080, china 2.Graduate University of chinese academy of sciences, Beijing 100080, china Beijing National Laboratory for Molecular sciences (BNLMS) State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing China Graduate University of chinese academy of sciences Beijing China

A study of the atmospheric photochemical reaction of CF3 radical with CO and O2.was performed by using a homemade ultraviolet photoelectron spectrometer-photoionization mass spectrometer (PES- PIMS). The electronic structures and mechanism of ionization and dissociation of CF3OC(O)OOC(O)- OCF3 were investigated. It was indicated that the two bands on the photoelectron spectrum of CF3OC(O)OOC(O)OCF3 are the result of ionization of an electron from a lone pair of oxygen and a fluo- rine lone pair of CF3 group. The outermost electrons reside in the oxygen lone pair. The experimental and theoretical first vertical ionization energy is 13.2. and 13.178 eV, respectively, with the PES and OVGF method. They are in good agreement. The photo ionization and dissociation processes were discussed with the help of theoretical calculations and PES-PIMS experiment. After ionization, the parent ions prefer the dissociation of the C-O bond and giving the fragments CF3OCO+ and CF3+. It demonstrated that the ultraviolet photoelectron and photoionization mass spectrometer could be ap- plied widely in the study of atmospheric photochemical reaction.

关键词： photochemical reaction CF3 radical ultraviolet photoelectron and photoionization mass spectroscopy transient species

Tissue Distribution and Purification of Prophenoloxidase in Larvae of Asian Corn Borer, Ostrinia furnacalis Guenée (Lepidoptera: Pyralidae)

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2004年第5期36卷 360-364页

作者： Cong-Jing FENG1,2.and Wen-Jun FU1* 1institute of Plant Physiology and Ecology, Shanghai institute for Biological {2., the chinese academy of sciences, Shanghai 2.002., china 2.he GraduateSchool of the chinese academy of sciences, Beijing 100039, china institute of Plant Physiology and Ecology Shanghai Institute for Biological Sciences the Chinese Academy of Sciences Shanghai 200025 China The Graduate School of the chinese academy of sciences Beijing 100039 China

Using ammonium sulphate precipitation, Blue-Sepharose CL-6B, Phenyl-Sepharose CL-4B, prophenoloxidase (PPO) was isolated and purified from hemolymph of Ostrinia furnacalis larvae. This zy- mogen was a heterodimer, and composed of two subunits with the relative molecular mass ranging from 66.2. kD to 97.4 kD determined by SDS-PAGE. Western blotting and indirect immunofluorescence test showed that PPO was present in integument, hemolymph plasma and cell membrane of granular hemocytes and oenocytoids of O. furnacalis larvae.

关键词： Ostrinia furnacalis prophenoloxidase tissue distribution purification

A mathematical model for solid liquid and mass transfer coupling and numerical simulation for hydraulic fracture in rock salt

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2005年第8期15卷 742-748页

作者： LIANG Weiguo 1,2. and ZHAO Yangsheng1(1. Mining Technology institute, Taiyuan University of Technology, Taiyuan 03002., china 2. Rock and Soil Mechanics institute, chinese academy of sciences, Wuhan 430071, china) Mining Technology institute Taiyuan University of Technology Taiyuan 030024 China Rock and Soil Mechanics institute Chinese Academy of Sciences Wuhan 430071 China

The hydraulic fracture in rock salt is a complicated solid fluid and mass transfer coupling process. Through theoretical analysis, a solid fluid and mass transfer coupling mathematical model of hydraulic fracture in rock salt is established in this work, and numerical simulations are carried out with the model. The simulation results indicate that rock salt cracks in the typical way of wing-crack(or tensile crack) during the fracture, and the relation of fracture aperture (w) with expanding distance (x) and fracture time (t) is w=(0.0034+0.0006t)e (0.0007+0.0018t)x. Furthermore, it has been found that both the water pressure in the crack and the expanding velocity of the crack decrease gradually as a result of the influence of salt dissolving during fracturing. These numerical simulations well illustrate the process of hydraulic fracture in rock salt and are significantly meaningful in engineering practice.

关键词： rock salt hydraulic fracture solid liquid and mass transfer coupling mathematical model numerical simulation.