首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   44篇
  免费   1篇
  2021年   1篇
  2018年   1篇
  2015年   1篇
  2014年   4篇
  2012年   3篇
  2010年   2篇
  2007年   3篇
  2006年   1篇
  2005年   1篇
  2004年   2篇
  2003年   8篇
  2002年   3篇
  2001年   2篇
  2000年   4篇
  1998年   1篇
  1993年   1篇
  1991年   2篇
  1989年   1篇
  1988年   1篇
  1985年   2篇
  1975年   1篇
排序方式: 共有45条查询结果,搜索用时 15 毫秒
1.
The isolation and identification of biphenyl catabolism products in Pseudomonas putida BS 893 (pBS241) showed the presence of benzoic, m-hydroxybenzoic and cinnamic acids. The two latter compounds were not found in biphenyl degradation by other bacterial strains. P. putida BS 893 (pBS241) differed from other biphenyl-positive Pseudomonas strains in the enzyme activity. These differences may stem from peculiarities in the pathway of biphenyl catabolism controlled by plasmid pBS241.  相似文献   
2.
By pharmacological manipulation of endogenous adenosine, using chemically distinct methods, we tested the hypothesis that endogenous adenosine tempers proinflammatory cytokine responses and oxyradical-mediated tissue damage during endotoxemia and sepsis. Rats were pretreated with varying doses of pentostatin (PNT; adenosine deaminase inhibitor) or 8-sulfophenyltheophylline (8-SPT; adenosine receptor antagonist) and then received either E. coli endotoxin (lipopolysaccharide; 0.01 or 2.0 mg/kg) or a slurry of cecal matter in 5% dextrose in water (200 mg/kg). Resultant levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, and IL-10 were measured in serum and in liver and spleen. Untreated, 2 mg/kg lipopolysaccharide elevated serum TNF-alpha, IL-1beta, and IL-10. PNT dose dependently attenuated, without ablating, the elevation in serum TNF-alpha and IL-1beta and raised liver and spleen IL-10. PNT also attenuated elevation of TNF-alpha in serum, liver, and spleen at 4 and 24 h after sepsis induction, and 8-SPT resulted in higher proinflammatory cytokines. Modulating endogenous adenosine was also effective in exacerbated (8-SPT) or diminished (PNT) tissue peroxidation. Survival from sepsis was also improved when PNT was used as a posttreatment. These data indicate that endogenous adenosine is an important modulatory component of systemic inflammatory response syndromes. These data also indicate that inhibition of adenosine deaminase may be a novel and viable therapeutic approach to managing the systemic inflammatory response syndrome without ablating important physiological functions.  相似文献   
3.
The type strain Penicillium vitale Pidoplichko et Bilai apud Bilai 1961 VKM F-3624 was found to considerably differ from a sibling species P. janthinellium (syn. P. simplicissimum) in some physiological and morphological features (growth rates at different temperatures, the size of philiades, and the shape of conidia), as well as in the pattern of the nitrogen-containing secondary metabolites produced (roquefortine, 3,12-dihydroroquefortine, meleagrin, aurantioclavine, indole-3-acetic acid, and N-acetyltryptamine). The data obtained suggest that P. vitale represent an independent species.  相似文献   
4.
It was demonstrated that the fungus Penicillium expansum 2-7, a resident strain of the orbital complex Mir, which became dominant at the end of a long-term space flight, formed biologically active secondary metabolites (antibiotics). Using physicochemical methods these metabolites were identified as xanthocyllin X and questiomycin A. The time courses of their biosyntheses during the growth and development of the producer culture were studied. The addition of zinc to the culture medium affected both the growth of the culture and the biosyntheses of the antibiotics. The concentrations of zinc in the medium, optimum for xanthocyllin X and questiomycin A production, were 0.3 and 3.0 mg/l, respectively.  相似文献   
5.
The study of the secondary metabolites of the relict strain Penicillium citrinum VKM FW-800 isolated from ancient Arctic permafrost sediments showed that this fungus produces agroclavine-1 and epoxyagroclavine-1, which are rare ergot alkaloids with the 5R,10S configuration of the tetracyclic ergoline ring system. The production of the alkaloids by the fungus showed a biphasic behavior, being intense in the phase of active growth and slowing down in the adaptive lag phase and in the stationary growth phase. The addition of zinc ions to the incubation medium led to a fivefold increase in the yield of the alkaloids. The alkaloid-producing Penicillium fungi isolated from different regions exhibited the same tendencies of growth and alkaloid production.  相似文献   
6.
Two diketopiperazine alkaloids, rugulosuvines A and B (tryptophan and phenylalanine are precursors), were isolated and purified from the culture liquid of Penicillium rugulosum VKM F-352 and Penicillium piscarium VKM F-325 fungi. Physical and physicochemical studies showed the absolute structure of rugulosuvine A. The absolute structure of rugulosuvine B was demonstrated to be similar to that of rugulosuvine A.  相似文献   
7.

Background  

Parathyroid hormone (PTH) and PTH-related peptide (PTHrP) belong to a family of endocrine factors that share a highly conserved N-terminal region (amino acids 1-34) and play key roles in calcium homeostasis, bone formation and skeletal development. Recently, PTH-like peptide (PTH-L) was identified in teleost fish raising questions about the evolution of these proteins. Although PTH and PTHrP have been intensively studied in mammals their function in other vertebrates is poorly documented. Amphibians and birds occupy unique phylogenetic positions, the former at the transition of aquatic to terrestrial life and the latter at the transition to homeothermy. Moreover, both organisms have characteristics indicative of a complex system in calcium regulation. This study investigated PTH family evolution in vertebrates with special emphasis on Xenopus and chicken.  相似文献   
8.
Pseudomonas strains harboring plasmids pBS3, pBS4, NAH7 were shown to carry out initial transformation of dibenzofurane to 4-[2'-(3'-hydroxy)-benzofuranyl]-2-keto-3-butenic acid due to broad substrate specificity of the enzymes of naphthalene catabolism nahA, nahB, nahC and nahD. These strains did not grow on dibenzofurane because of the inability of the enzyme nahE to split pyruvate of 4-[2'-(3' hydroxy)-benzofuranyl]-2-keto-3-butenic acid, which leads to accumulation of the latter. The strains harboring plasmids pBS2 and NPL-1 are not capable of any transformation of dibenzofurane.  相似文献   
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号