荧光法直接测定环境中邻羟基苯甲酸和苯酚混合物的含量

本文研究了用荧光分光度法测定环境水中苯酚和邻羟基苯甲酸的含量碘在ＰＨ〉１１时直接测定邻羟基苯甲酸的含量,波长为λｅｘ／λｅｍ＝２８９／３３８ｎｍ,检出 为３．４ｎｇ／ｍＬ,线性范围０－６．０μｇ／ｍＬ。在ＰＨ＝６,波长为λｅｘ／λｅｍ＝２７０／２９７ｎｍ测得苯酚含量,检出限为４．０ｎｇ／ｍＬ,线性范围在０－０．８５μｇ／ｍＬ,回收率为９８－１０１％,,结果满意。     

荧光法直接测定环境水中邻羟基苯甲酸和苯酚混合物的含量

本文研究了用荧光分光光度法测定环境水中苯酚和邻羟基苯甲酸的含量,在pH＞11时直接测定邻羟基苯甲酸的含量,波长为λex/λem=289/338nm,检出限为3.4ng/mL,线性范围0-6.0μg/mL.在pH=6,波长为λex/λem=270/297nm测得苯酚含量,检出限为4.0ng/mL,线性范围在0-0.85μg/mL,回收率为98%-101%,结果满意.     

Determination of Multiple φ-Torsion Angles in Proteins by Selective and Extensive C Labeling and Two-Dimensional Solid-State NMR

We describe an approach to efficiently determine the backbone conformation of solid proteins that utilizes selective and extensive ¹³C labeling in conjunction with two-dimensional magic-angle-spinning NMR. The selective ¹³C labeling approach aims to reduce line broadening and other multispin complications encountered in solid-state NMR of uniformly labeled proteins while still enhancing the sensitivity of NMR spectra. It is achieved by using specifically labeled glucose or glycerol as the sole carbon source in the protein expression medium. For amino acids synthesized in the linear part of the biosynthetic pathways, [1-¹³C]glucose preferentially labels the ends of the side chains, while [2-¹³C]glycerol labels the C^α of these residues. Amino acids produced from the citric-acid cycle are labeled in a more complex manner. Information on the secondary structure of such a labeled protein was obtained by measuring multiple backbone torsion angles φ simultaneously, using an isotropic–anisotropic 2D correlation technique, the HNCH experiment. Initial experiments for resonance assignment of a selectively ¹³C labeled protein were performed using ¹⁵N–¹³C 2D correlation spectroscopy. From the time dependence of the ¹⁵N–¹³C dipolar coherence transfer, both intraresidue and interresidue connectivities can be observed, thus yielding partial sequential assignment. We demonstrate the selective ¹³C labeling and these 2D NMR experiments on a 8.5-kDa model protein, ubiquitin. This isotope-edited NMR approach is expected to facilitate the structure determination of proteins in the solid state.     

高效液相色谱法测定血小板释放的5-HT

用HPLC／ECD法,采用国产10cmC18柱,测定激活因子诱导的血小板5－HT释放反应。日内变异系数为4.65％。线性范围为0.0025～1mg／L。方法具有速度快、灵敏度高、特异性强、样品制备简便、所需作本量少、试剂成本低等优点,能准确反应血小板做活状况,可应用于其它生物样本。     

A New Competitive Inhibitory Monoclonal Antibody to Carboxypcptidase A (CPA)

Catalyticantibodiesareanewclassofbiocatalysts,andhavebeenusedtocatalyzemanytypesofchemicalreactionsuccessfully'.Atpresent,itisdifficulttousecatalyticantibodiestocatalyzethehydrolysisofamidebond.Howtodesignandpreparethecatalyticantibodiesthatcaneffectivelycatalyzethehydrolysisofamidebondhasbeenanunsolvedproblem.Butthehydrolysisandsynthesisofamidebondareveryimportantchemicalandbiologicalreactions.Therefore,toproducethecatalyticantibodieswhichcancatalyzethehydrolysisofamidebondisasignificantresea…     

A Comparison of Three Heuristic Algorithms for Molecular Docking

Thed0ckingpr0cedurebetweeninhibitorsandproteinisaverys0phisticatedoptimizati0npr0blem;itisverydifficuIttocarry0utminimizati0nusinggradientmeth0dssuchasthesteepestdescentmeth0d,Gauss-Newtonmethod,whichareveryeasytofallint0theI0calpotentialwellsandverydifficultt0escapefr0mthem.S0s0meheuristicmeth0dshavebeenintr0ducedint0thestudies0fmolecuIarrec0gniti0n.Howt0chooseadequate0ptin1izationmeth0dinthed0ckingprocedureiscriticaIt0thecalcuIati0nresults.Inthispaper,wedescribetheimplementati0nandc0mpari…     

Spectroscopic Study of the Interaction between New Fluorescent Dyes with Nucleic Acids

Considerableefforthasbeencofltinuingtofocusonthedevelopmentofnewfluorescentdyestorecognizenucleicacids'-'.Althoughdansylisawell-knownsensitivehydrophobicprobewhichhasbeenwidelyutilizedasafluorescentprobeforthestudyofproteins,yetlittleefforthasbeenfocusedontheexploringdansylamidederivativeswhichmayhavespecificeffectsonnucleicacids.Sincethebindingaffinityofsuchfluorophorestopolynucleotideswasgreatlyaffectedbytheirsidechainsubstitutions,inthisworkseveralnewdansylderivativeswithspecificbindingtonu…     

Yamabe不变量与在非紧流形上预定纯量曲率

我们得到关于Ｙａｍａｂｅ不变量的某些条件,使得非紧流形通过共形形变后,纯量曲率为常数．     

变质量完整力学系统的Lie对称与守恒量

研究变质量完整系统的Lie对称和守恒量。利用常微分方程在无限小变换下的不变性建立系统Lie对称的确定方程。给出结构方程和守恒量。举例说明结果的应用。     

单位球面中极小子流形的曲率拼挤

本文证明了单位球面中极小子流形的一些拼挤定理,特别注意到单位球面中的极小超曲面、给出了截曲率的拼挤常数,我们也改进了由Ｎ．Ｅｊｉｒｉ得到的Ｒｉｃｃｉ曲率拼挤常数。