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藻胆体低温下(77K)时间分辨的能量传递过程 藻胆体低温下(77K)时间分辨的能量传递过程
Science in China. Series B, Chemistry, life sciences & earth sciences Pub Date : 1995-03-20 DOI: 10.1360/ZB1995-25-3-277
夏安东, 朱晋昌, 张新夷, 汪河洲, 郑锡光, M.Sudh
{"title":"藻胆体低温下(77K)时间分辨的能量传递过程","authors":"夏安东, 朱晋昌, 张新夷, 汪河洲, 郑锡光, M.Sudh","doi":"10.1360/ZB1995-25-3-277","DOIUrl":"https://doi.org/10.1360/ZB1995-25-3-277","url":null,"abstract":"利用皮秒(10 -12 s)时间分辨荧光光谱技术研究了蓝菌Westiellopsis prolifica中藻胆体(PBS)低温下(77K)的激发能传递的动力学过程.观察到低温下(77K)藻胆体内从C-PC-杆到APC-核之间的2条能量传递途径,它们分别是:F650→(19ps)F662→(60ps)F679和F650→(42ps)F668→(250ps)F685.并认为藻胆体内的2个终端发射体之间在能量传递过程中是相互独立的.","PeriodicalId":21648,"journal":{"name":"Science in China. Series B, Chemistry, life sciences & earth sciences","volume":"49 1","pages":"277-282"},"PeriodicalIF":0.0,"publicationDate":"1995-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86075384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
β-三苯锗丙酸与α-羟基膦酸酯缩合反应的研究和产物结构确定 β-三苯锗丙酸与α-羟基膦酸酯缩合反应的研究和产物结构确定
Science in China. Series B, Chemistry, life sciences & earth sciences Pub Date : 1995-03-10 DOI: 10.1360/ZB1995-25-3-240
毛丽娟张鸣 陈茹玉, Mao Li-Juan Zhang Ming Chen Ru-Yu
{"title":"β-三苯锗丙酸与α-羟基膦酸酯缩合反应的研究和产物结构确定","authors":"毛丽娟张鸣 陈茹玉, Mao Li-Juan Zhang Ming Chen Ru-Yu","doi":"10.1360/ZB1995-25-3-240","DOIUrl":"https://doi.org/10.1360/ZB1995-25-3-240","url":null,"abstract":"研究了β-三苯锗丙酸与α-羟基膦酸酯的缩合反应,并详细探讨、分析了常规酯缩合方法在此不能奏效的原因.合成出一系列O,O-二烷基-α-(β-三苯锗基)丙酰酯基膦酸酯新化合物(Ⅰ).培养出I a 单晶.X射线晶体结构分析表明,Ph 3 Ge基与O=P(OR) 2 基由于相互排斥作用很大,这两个基团几乎处于同一平面相距最远的位置上.初步体内、外抗癌活性结果表明,此类化合物在体内、外均有一定抗癌活性.","PeriodicalId":21648,"journal":{"name":"Science in China. Series B, Chemistry, life sciences & earth sciences","volume":"118 1","pages":"240-245"},"PeriodicalIF":0.0,"publicationDate":"1995-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88909902","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
La 2— x Sr x CoO 4 ± λ ( x =0～2)的合成,表征和完全氧化催化性能的研究 La 2— x Sr x CoO 4 ± λ ( x =0～2)的合成,表征和完全氧化催化性能的研究
Science in China. Series B, Chemistry, life sciences & earth sciences Pub Date : 1995-03-10 DOI: 10.1360/ZB1995-25-3-225
程铁欣, 杨向光
{"title":"La 2— x Sr x CoO 4 ± λ ( x =0～2)的合成,表征和完全氧化催化性能的研究","authors":"程铁欣, 杨向光","doi":"10.1360/ZB1995-25-3-225","DOIUrl":"https://doi.org/10.1360/ZB1995-25-3-225","url":null,"abstract":"合成了x值不同的La 2— x Sr x CoO 4 ± λ ( x =0～2)系列复合氧化物.用XRD研究了这一系列氧化物的晶体结构,结果表明 x 在0.25～1.5之间可形成具有K 2 NiF 4 结构的复合氧化物.用化学分析方法测定了过渡金属Co的价态和±λ含量与x值的关系.用IR,TPD,TPR,XPS,SEM等方法研究了这类复合氧化物的氧化还原性能,所含不同氧种,考察了对CH 4 ,CO的完全氧化活性,并对其活性与化学组成及结构间的关系进行了讨论.","PeriodicalId":21648,"journal":{"name":"Science in China. Series B, Chemistry, life sciences & earth sciences","volume":"15 6","pages":"225-233"},"PeriodicalIF":0.0,"publicationDate":"1995-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91481007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Functional expression of gap junction gene Cx43 and the myogenic differentiation of rhabdomyosarcoma cells. 间隙连接基因Cx43的功能表达与横纹肌肉瘤细胞成肌分化。
Science in China. Series B, Chemistry, life sciences & earth sciences Pub Date : 1995-03-10 DOI: 10.1360/YB1995-38-3-305
Z. Lin, Z. Zhang, Y. Han, C. Naus, K. Yu, H. Holtzer
{"title":"Functional expression of gap junction gene Cx43 and the myogenic differentiation of rhabdomyosarcoma cells.","authors":"Z. Lin, Z. Zhang, Y. Han, C. Naus, K. Yu, H. Holtzer","doi":"10.1360/YB1995-38-3-305","DOIUrl":"https://doi.org/10.1360/YB1995-38-3-305","url":null,"abstract":"Rhabdomyosarcoma (RD) cells express low levels of the gap junction protein connexin 43 (Cx43), and its mRNA, and display very weak gap junctional intercellular communication (GJIC) as detected by Cx43 immunofluorescence, slot-blot and dye-transfer methods. These cells grow rapidly and show aberrant and incomplete myogenic differentiation. To investigate the role of gap junctions in these cells, the expression of Cx43 with relation to cell growth and myogenic differentiation in RD single-cell subclones-RDL3 and RDL6 is studied. The subclone RDL3 grows slowly and displays better myogenic differentiation. The expression of Cx43, its mRNA and the GJIC in RDL3 is comparable to that in normal myoblasts. Another subclone RDL6 which grows rapidly, but is poorly differentiated, expresses very low levels of Cx43 and its mRNA, and very weak GJIC. By using the calcium phosphate precipitate transfection technique, a full-length cDNA-encoding Cx43 and a pSV2neo have been introduced into the RDL6 cells. Several stably transfected clones have been obtained. A stable Cx43-transfectant clone RDL6/C-4 expresses high level of Cx43 and its mRNA, and results in dramatic increase of GJIC. These cells grow slowly but display the enhanced myogenic differentiation. A correlation between the down-regulation of Cx43 gene expression and a reduced expression of myogenic differentiation in RD cells is is demonstrated. Forced expression of Cx43 not only inhibits cell growth but also correlates with the improved myogenic differentiation of RD cells.","PeriodicalId":21648,"journal":{"name":"Science in China. Series B, Chemistry, life sciences & earth sciences","volume":"34 1","pages":"305-12"},"PeriodicalIF":0.0,"publicationDate":"1995-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73115715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
准经典轨迹法对CH 4 ,SiH 4 ,GeH 4 分子振动激发态局域模振动的研究 准经典轨迹法对CH 4 ,SiH 4 ,GeH 4 分子振动激发态局域模振动的研究
Science in China. Series B, Chemistry, life sciences & earth sciences Pub Date : 1995-03-10 DOI: 10.1360/ZB1995-25-3-234
杨忠志唐敖庆 李慎敏, Yang Zhong-Zhi Tang Ao-Qiang Li Shen-Min
{"title":"准经典轨迹法对CH 4 ,SiH 4 ,GeH 4 分子振动激发态局域模振动的研究","authors":"杨忠志唐敖庆 李慎敏, Yang Zhong-Zhi Tang Ao-Qiang Li Shen-Min","doi":"10.1360/ZB1995-25-3-234","DOIUrl":"https://doi.org/10.1360/ZB1995-25-3-234","url":null,"abstract":"采用准经典轨迹法,讨论了XH 4 分子(X=C,Si,Ge)简正模和局域模振动激发态能量与时间的变化关系.结果表明,CH 4 分子中,C—H键伸缩振动与H—C—H弯曲振动耦合作用较大,能量转移迅速;SiH 4 ,GeH 4 分子中,这种耦合作用较小,可以观察到明显的能量驰豫.在一定的振动激发态下存在着近似的局域模振动.","PeriodicalId":21648,"journal":{"name":"Science in China. Series B, Chemistry, life sciences & earth sciences","volume":"17 1","pages":"234-239"},"PeriodicalIF":0.0,"publicationDate":"1995-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85072884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
HBV surface antigen proteins with deletions in the preS region. preS区缺失的HBV表面抗原蛋白。
Science in China. Series B, Chemistry, life sciences & earth sciences Pub Date : 1995-03-01
K Xu, X Yu, Y Kong, Y Wang, Z Li
{"title":"HBV surface antigen proteins with deletions in the preS region.","authors":"K Xu,&nbsp;X Yu,&nbsp;Y Kong,&nbsp;Y Wang,&nbsp;Z Li","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Four pairs of HBV surface antigen genes, in which the preS region was partially deleted, were constructed by the polymerase chain reaction (PCR). The comparison of the levels of the expression in mammalian cells of these genes and the ones constructed before, and the properties of these gene products showed that the missing of a part of the preS region did not affect the overall spatial structure of the S region and the surface localization of the preS region. The removal of the preS1 retention sequence (a. a. 2-19) alleviated significantly the shelter of the major antigenic determinants in the S region by the preS sequence. It was found that the long preS region seriously impaired the secretion of the surface antigen proteins from mammalian cells. In addition to the previously reported preS1 retention sequence, the preS1 sequence (a.a. 48-65) may also inhibit the secretion of the surface antigen proteins, whereas the preS2 region exerts no major influence on the retention of the large surface antigen protein. One of the expressed surface antigen proteins, in which the preS1 sequence (a.a. 21-47) and the S region were directly fused, deserves further study and may be developed into a new HBV vaccine which contains the preS1 binding site for hepatocyte receptors due to its stability, fine secretability and strong preS1 antigenicity.</p>","PeriodicalId":21648,"journal":{"name":"Science in China. Series B, Chemistry, life sciences & earth sciences","volume":"38 3","pages":"320-7"},"PeriodicalIF":0.0,"publicationDate":"1995-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18767277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Metabolic approach for regulation of IL-1 beta in vivo. 体内调节IL-1 β的代谢方法。
Science in China. Series B, Chemistry, life sciences & earth sciences Pub Date : 1995-03-01
T Yang, X Zhu, B Shen, W Xu
{"title":"Metabolic approach for regulation of IL-1 beta in vivo.","authors":"T Yang,&nbsp;X Zhu,&nbsp;B Shen,&nbsp;W Xu","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>IL-1 beta, the autoantibodies to IL-1 beta and IL-1 beta-containing immune complex in pleural effusion and cerebrospinal fluid were detected using anti-recombinant human IL-1 beta monoclonal antibody. The results indicate that IL-1 beta is detectable in some cases, and the amounts decrease gradually with the chemotherapy following the autoantibodies and the specific detectable immune complex. These autoantibodies may have a feedback effect, inhibiting the IL-1 beta activity, and forming the immune complex to speed the clearance of activated IL-1 beta.</p>","PeriodicalId":21648,"journal":{"name":"Science in China. Series B, Chemistry, life sciences & earth sciences","volume":"38 3","pages":"345-51"},"PeriodicalIF":0.0,"publicationDate":"1995-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18767927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Nucleotide sequence of maize dwarf mosaic virus capsid protein gene and its expression in Escherichia coli. 玉米矮花叶病毒衣壳蛋白基因核苷酸序列及其在大肠杆菌中的表达。
Science in China. Series B, Chemistry, life sciences & earth sciences Pub Date : 1995-03-01
J Sai, L Kang, Z Huang, C Shi, B Tian, Y Xie
{"title":"Nucleotide sequence of maize dwarf mosaic virus capsid protein gene and its expression in Escherichia coli.","authors":"J Sai,&nbsp;L Kang,&nbsp;Z Huang,&nbsp;C Shi,&nbsp;B Tian,&nbsp;Y Xie","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The 3'-terminal 1,279 nucleotide sequence of maize dwarf mosaic virus (MDMV) genome has been determined. This sequence contains an open reading frame of 1,023 nucleotides and a 3'-non-coding region of 256 nucleotides. The open reading frame includes all of the coding regions for the viral capsid protein (CP) and part of the viral nuclear inclusion protein (NIb). The predicted viral CP consists of 313 amino acid residues with a calculated molecular weight of 35,400. The amino acid sequence of the viral CP derived from MDMV cDNA shows about 47%-54% homology to that of 4 other potyviruses. The viral CP gene was constructed in frame with the lacZ gene in pUC19 plasmid and expressed in E. coli cells. The fusion polypeptide positively reacted in Western blot with an antiserum prepared against the native viral CP.</p>","PeriodicalId":21648,"journal":{"name":"Science in China. Series B, Chemistry, life sciences & earth sciences","volume":"38 3","pages":"313-9"},"PeriodicalIF":0.0,"publicationDate":"1995-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18767276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Comparison between conformational change and inactivation rates of aminoacylase during denaturation in urea solutions. 尿素溶液中变性过程中氨基酰化酶的构象变化和失活速率的比较。
Science in China. Series B, Chemistry, life sciences & earth sciences Pub Date : 1995-03-01
H Wang, X Wang, T Zhang, H Zhou
{"title":"Comparison between conformational change and inactivation rates of aminoacylase during denaturation in urea solutions.","authors":"H Wang,&nbsp;X Wang,&nbsp;T Zhang,&nbsp;H Zhou","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The kinetic method of the substrate reaction in the presence of inactivator previously described by Tsou has been applied to the determination of inactivation rates of aminoacylase during denaturation in urea solutions. The protective effect of substrate on the inactivation of aminoacylase by urea has been investigated. Simultaneously, the comparison between conformational change and inactivation rates of enzyme in the urea solutions of different concentrations has been studied. Results obtained show that the inactivation rate constants of the enzyme are larger than the rate constants of conformational changes. The present results show that the active site of metal enzyme-aminoacylase is also located in a limited and flexible region of the molecule that is more sensitive to denaturants than the enzyme as a whole.</p>","PeriodicalId":21648,"journal":{"name":"Science in China. Series B, Chemistry, life sciences & earth sciences","volume":"38 3","pages":"328-35"},"PeriodicalIF":0.0,"publicationDate":"1995-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18767926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Functional expression of gap junction gene Cx43 and the myogenic differentiation of rhabdomyosarcoma cells. 间隙连接基因Cx43的功能表达与横纹肌肉瘤细胞成肌分化。
Science in China. Series B, Chemistry, life sciences & earth sciences Pub Date : 1995-03-01
Z Lin, Z Zhang, Y Han, C C Naus, K R Yu, H Holtzer
{"title":"Functional expression of gap junction gene Cx43 and the myogenic differentiation of rhabdomyosarcoma cells.","authors":"Z Lin,&nbsp;Z Zhang,&nbsp;Y Han,&nbsp;C C Naus,&nbsp;K R Yu,&nbsp;H Holtzer","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Rhabdomyosarcoma (RD) cells express low levels of the gap junction protein connexin 43 (Cx43), and its mRNA, and display very weak gap junctional intercellular communication (GJIC) as detected by Cx43 immunofluorescence, slot-blot and dye-transfer methods. These cells grow rapidly and show aberrant and incomplete myogenic differentiation. To investigate the role of gap junctions in these cells, the expression of Cx43 with relation to cell growth and myogenic differentiation in RD single-cell subclones-RDL3 and RDL6 is studied. The subclone RDL3 grows slowly and displays better myogenic differentiation. The expression of Cx43, its mRNA and the GJIC in RDL3 is comparable to that in normal myoblasts. Another subclone RDL6 which grows rapidly, but is poorly differentiated, expresses very low levels of Cx43 and its mRNA, and very weak GJIC. By using the calcium phosphate precipitate transfection technique, a full-length cDNA-encoding Cx43 and a pSV2neo have been introduced into the RDL6 cells. Several stably transfected clones have been obtained. A stable Cx43-transfectant clone RDL6/C-4 expresses high level of Cx43 and its mRNA, and results in dramatic increase of GJIC. These cells grow slowly but display the enhanced myogenic differentiation. A correlation between the down-regulation of Cx43 gene expression and a reduced expression of myogenic differentiation in RD cells is is demonstrated. Forced expression of Cx43 not only inhibits cell growth but also correlates with the improved myogenic differentiation of RD cells.</p>","PeriodicalId":21648,"journal":{"name":"Science in China. Series B, Chemistry, life sciences & earth sciences","volume":"38 3","pages":"305-12"},"PeriodicalIF":0.0,"publicationDate":"1995-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"18767274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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