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101.
XU Zhi-Jin YAN Ji-MinInstitute of Chemistry Chinese Academy of Sciences Beijing China 《中国化学》1996,14(6):481-489
The interaction between C60's in solid C60 has been calculated by (exp-6-1) potential, and the cause and the controlled factor of the high rapid rotations of C60 's were discussed. In order to describe the disordered degree of C60 rotation, an equivalent M is introduced. The phase transitions at the ~260 K and at the ~90 K are studied from the viewpoint of C60 rotation. The potential barriers of the ordered rotation below the ~260 K and the disordered rotation above the ~260 K have been given, and the effect of the external pressure on the temperature of phase transition has also been given. 相似文献
102.
LI Wan-nan ZHUANG Yan LI He SUN Ying FU Yao WU Xiao-xia ZHAO Zhi-zhuang FU Xue-qi . Edmond H. Fischer Signal Transduction Laboratory College of Life Sciences . Key Laboratory for Molecular Enzymology & Engineering Ministry of Education Jilin University Changchun P. R. China 《高等学校化学研究》2008,24(5):592-596
This study is focused on the expression of an SH2 domain-truncated form of protein tyrosine phosphatase SHP-1(designated ΔSHP-1) and the preparation of its polyclonal antibodies. A cDNA fragment encoding ΔSHP-1 was amplified by PCR and then cloned into the pT7 expression vector. The recombinant pT7-ΔSHP-1 plasmid was used to transform Rosetta(DE3) E. coli cells. ΔSHP-1 was distributed in the exclusion body of E. coli cell extracts and was purified through a two-column chromatographic procedure. The purified enzyme exhibited an expected molecular weight on SDS-gels and HPLC gel filtration columns. It possesses robust tyrosine phosphatase activity and shows typical enzymatic characteristics of classic tyrosine phosphatases. To generate polyclonal anti-ΔSHP-1 antibodies, purified recombinant ΔSHP-1 was used to immunize a rabbit. The resultant anti-serum was subjected to purification on ΔSHP-1 antigen affinity chromatography. The purified polyclonal antibody displayed a high sensitivity and specificity toward ΔSHP-1. This study thus provides the essential materials for further investigating the biological function and pathological implication of SHP-1 and screening the inhibitors and activators of the enzyme for therapeutic drug development. 相似文献
103.
随着糖组学的发展,研究表明某些疾病如肿瘤等的发生伴随着体内糖蛋白表面糖链结构的变化,而糖链结构的形成与修饰经过糖基转移酶、糖苷酶和磺基转移酶的参与.本研究从Genebank等数据库中选取人类糖基转移酶基因127条、糖苷酶基因34条和磺基转移酶34条以及管家基因10条.通过对每个基因的mRNA序列进行探针设计,制备出一款糖类相关基因芯片,用于研究糖类相关基因的表达谱,旨在揭示疾病发生与糖类相关基因表达变化的关联性.制备的芯片应用于人肝癌细胞系SMMC-7721与正常肝细胞系Chang’s liver的研究,筛选出差异表达的基因34个,其中上调基因19个、下调基因15个.通过对2个上调基因和2个下调基因进行Realtime-PCR验证,得到了一致的实验结果. 相似文献
104.
Xue Yuan HU Xue Sen FAN Xin Ying ZHANG Gui Rong QU Yan Zhen LI School of Chemical Environmental Sciences Henan Key Laboratory for Environmental Pollution Control Henan Normal University Xinxiang Chongqing University of Medical Sciences Chongqing 《中国化学快报》2005,(7)
Construction of tetrahydropyran rings has attracted a great deal of interests in organic synthesis in recent years1, since tetrahydropyran moiety constitutes a structural unit in a number of natural products2. In addition, tetrahydropyran derivatives possess wide range of biological activities and pharmacological properties, such as anticancer activity3 and antihypersensitivity4. Many methods for the preparation of such compounds have already been developed5. Among them, condensation of α, β… 相似文献
105.
YU Qing CAO Jie LIU Tao WANG Zhi-xiang . College of Chemistry Chemical Engineering Graduate School of the Chinese Academy of Sciences Beijing P. R. China 《高等学校化学研究》2009,25(3)
It is well-known that primary amines form inclusive complexes with crown ethers. This kind of noncova-lently inclusive complexes,exemplified tryptophan complex with 18-crown-6,was studied by combination of two experimental methods,fluorimetry and mass spectrometry,with theoretical calculation. Fluorescence intensity of tryptophan in the absence and the presence of 18-crown-6 in aqueous HAc-NaAc buffer solution at pH=3.73 has been studied by fluorometry. The fluorescence intensity decreases significantly wit... 相似文献
106.
Films obtained via drying a polymeric latex dispersion are normally colloidal crystalline where latex particles are packed into a face centered cubic (fcc) structure.Different from conventional atomic crystallites or hard sphere colloidal crystallites,the crystalline structure of these films is normally deformable due to the low glass transition temperature of the latex particles.Upon tensile deformation,depending on the drawing direction with respect to the normal of specific crystallographic plane,one ... 相似文献
107.
Hua Su Zhao Hui Yuan Jing Li Shu Ju Guo Li Ping Deng Li Jun Han Xiao Bin Zhu Da Yong Shi 《中国化学快报》2009,20(4):456-458
Two new bromoindole alkaloids have been isolated from the ethanolic extract of the red alga Laurencia similis.On the basis of chemical and spectroscopic methods(including 1D and 2D NMR technique),their structures have been elucidated as 2,2′,5,5′,6,6′-sixibromo -3,3′-bi-1H-indole and 3,5-dibromo-1-methylindole,respectively. 相似文献
108.
Two new triterpenes,2α,3β-dihydroxyurs-12-en-18,19-epoxy-28-oic acid(1)and 18,19-seco,2α,3α-dihydroxyl-19-oxo-urs-11, 13(18)-dien-28-oic acid(2)were isolated from the herbaceous part of Duchesnea indica.Their structures were elucidated by spectroscopic analysis,including 2D NMR technique.The isolated compounds exhibited moderate cytotoxic activities against HeLa and L929 cell lines. 相似文献
109.
Ying Peng Huo Xu Qiu Wei Yan Shao Lin Kun An Xian Zhang Bu Lian Quan Gu 《中国化学快报》2009,20(11):1291-1295
Series of new 2-aryl-6-styryl-2,3-dihydropyridin-4(1H)-one derivatives were synthesized in acceptable to good yields by treatment of the curcuminoids with aqueous ammonia,the mechanism was proposed.By modification of the primary products,total 13 new compounds were obtained.The structures of all products were elucidated by spectroscopy analysis including HR-MS,~1H NMR and ~(13)C NMR. 相似文献
110.
TUNG ChenHo 《中国科学B辑(英文版)》2009,(6)
Imine-bridged TTF-π-pyridine derivatives, 2NTTF, 3NTTF and 4NTTF, were synthesized and the cation-binding study was performed. It is noted that with the addition of the micromolar concentration of Pb2+ to the solution, these compounds display remarkable changes in solution color, 1H NMR spectra and electrochemical properties. The nitrogen atom of the imine-bridge in 2NTTF not only serves as a π-conjugated spacer but also participates in the sensing and coordinating properties. 相似文献