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121.
Jin-Cherng Lien Li-Jiau Huang Jih-Pyang Wang Che-Ming Teng Kuo-Hsiung Lee Sheng-Chu Kuo 《Bioorganic & medicinal chemistry》1997,5(12):2111-2120
A series of 2-substituted 3-chloro-1,4-naphthoquinones was synthesized, and the antiplatelet, antiinflammatory, and antiallergic activities of these compounds were evaluated. The structure-activity relationships in this series were also examined. Most of the 2-alkyl/arylcarboxamido derivatives of 3-chloro-1,4-naphthoquinone showed potent activities with similar trends in each of the activities evaluated. 相似文献
122.
Jih-Shiou Liu Yau-Heiu Hsu Tzu-Yu Huang Na-Sheng Lin 《Journal of molecular evolution》1997,44(2):207-213
Satellite RNA of bamboo mosaic potexvirus (satBaMV) is a linear RNA molecule which encodes a 20-kDa nonstructural protein.
Sequences of seven different satBaMV isolates from bamboo hosts in three genera showed 0.7% to 7.5% base variation which spanned
the whole RNA molecule. However, the putative 20-kDa open reading frame was all preserved in these isolates. The phylogenetic
relationship based on the nucleotide sequence did not show particular grouping of satBaMV from the host in one genus; neither
was the grouping of satBaMV evident by location of sampling. Putative secondary structures of the 3′ untranslated regions
showed a basic pattern with conserved hexanucleotides (ACCUAA) and polyadenylation signal (AAUAAA) located in the loop regions.
Although the satBaMV-encoded 20-kDa protein is a nonstructural protein, its predicted secondary structure contains eight-stranded
β-sheets which may form ``jelly-roll' structure similar to that found in capsid protein encoded by satellite virus of panicum
mosaic virus.
Received: 26 June 1996 / Accepted: 9 September 1996 相似文献
123.
124.
Nonuniform spatial patterns of respiratory activity within biofilms during disinfection. 总被引:12,自引:5,他引:7 下载免费PDF全文
Fluorescent stains in conjunction with cryoembedding and image analysis were applied to demonstrate spatial gradients in respiratory activity within bacterial biofilms during disinfection with monochloramine. Biofilms of Klebsiella pneumoniae and Pseudomonas aeruginosa grown together on stainless steel surfaces in continuous-flow annular reactors were treated with 2 mg of monochloramine per liter (influent concentration) for 2 h. Relatively little biofilm removal occurred as evidenced by total cell direct counts. Plate counts (of both species summed) indicated an average 1.3-log decrease after exposure to 2 mg of monochloramine per liter. The fluorogenic redox indicator 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) and the DNA stain 4',6-diamidino-2-phenylindole (DAPI) were used to differentiate respiring and nonrespiring cells in biofilms. Epifluorescence micrographs of frozen biofilm cross sections clearly revealed gradients of respiratory activity within biofilms in response to monochloramine treatment. These gradients in specific respiratory activity were quantified by calculating the ratio of CTC and DAPI intensities measured by image analysis. Cells near the biofilm-bulk fluid interface lost respiratory activity first. After 2 h of biocide treatment, greater respiratory activity persisted deep in the biofilm than near the biofilm-bulk fluid interface. 相似文献
125.
新疆10种沙生植物旱生结构的解剖学研究 总被引:17,自引:1,他引:16
新疆10种沙生植物的形态解剖研究表明,它们为适应沙生环境形态结构发生变化。叶器官的形态呈三种类型:叶片退化成膜质或鳞片状,而由同化枝执行光合功能;叶片上下都具栅栏组织,表皮角质膜厚,表皮毛发达,气孔下陷,输导组织和机械组织都发达;叶片肉质化,叶肉组织不分化,贮水组织发达而输导组织不发达。轴器官中厚壁组织发达,围绕维管组织,维管组织内部也有发达的厚壁组织。根中普遍具有周皮,一些植物存在异常的维管组织,部分植物还具有粘液细胞或结晶。沙生植物形成各种旱生结构,以不同的方式适应沙生环境。 相似文献
126.
127.
大鼠胸部照射γ射线20Gy,照射后观察支气管肺泡灌洗液(BALF)中蛋白质含量、细胞总数和分类及巨噬细胞存活率,肺指数及肺组织纤溶活力,并做了大体解剖和组织学检查。结果为:照射后2周开始BALF中蛋白质含量、细胞总数和中性粒细胞即明显增多,照射后1——2个月持续处于高水平,高峰在1.5─2个月,照射后3─4个月有所下降,肺指数有相应变化;肺组织纤溶活力则相反,从照射后2周开始持续下降,至照射后2个月已降至最低,接近于零。形态学观察也见到有早期肺水肿和晚期肺萎缩等变化。由上结果可见,大鼠胸部照射后的早期主要为渗出性病变和纤溶活力的降低。文中讨论了照射后血管内皮细胞的损伤在放射性肺损伤发病中的作用。 相似文献
128.
129.
We have generated four xenogeneic rat antimouse IgG3 monoclonal antibodies recognizing at least three different antigenic determinants (epitopes) on BALB/c IgG3 molecules. These antibodies were used in solid-phase blocking radioimmunoassays for detection of the epitopes in sera of 40 inbred strains and 134 wild mice. These antibodies detect genetic polymorphism of IgG3 isotype among wild mice even though there is no polymorphism found among 40 inbred strains tested (except X-chromosome-linked immunodeficient CBA/N strain which lacks IgG3 molecules). An IgG3 variant was also isolated from hybridomas derived from Mus spretus.Abbreviations
Igh-C
immunoglobulin heavy chain constant region
- PVC
polyvinyl chloride
- RIA
radioimmune assay
- ELISA
enzyme linked immunosorbent assay 相似文献
130.
Hormone-regulated expression of cellular rasH oncogene in mammary carcinomas in rats 总被引:1,自引:0,他引:1
Differential gene expression has been observed in hormone-dependent rat mammary carcinomas during their growth and regression. A 22K MW protein, a prominent in vitro translation product of the growing as compared to the regressing tumor, was identified as the c-rasH-21,000-dalton transforming protein (p21) using a monoclonal antibody that reacts specifically with Harvey-related p21 species. The amount of p21-translated protein sharply decreased in the translation products of the regressing tumors within 6 hours post ovariectomy or dibutyryl cyclic AMP treatment. The results show that an enhanced expression of the c-rasH oncogene is associated with hormone-dependent growth of mammary carcinomas in vivo and that suppression of this oncogene precedes the tumor regression induced by either hormone withdrawal or dibutyryl cyclic AMP treatment. 相似文献