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   99篇
  免费   9篇
  2021年   1篇
  2020年   1篇
  2019年   1篇
  2018年   1篇
  2017年   1篇
  2016年   5篇
  2015年   2篇
  2014年   1篇
  2013年   3篇
  2012年   4篇
  2011年   7篇
  2010年   5篇
  2009年   4篇
  2008年   1篇
  2007年   2篇
  2006年   3篇
  2005年   3篇
  2004年   3篇
  2003年   7篇
  2002年   4篇
  2001年   1篇
  2000年   1篇
  1999年   3篇
  1998年   7篇
  1994年   2篇
  1993年   2篇
  1992年   3篇
  1991年   3篇
  1989年   2篇
  1988年   3篇
  1986年   1篇
  1985年   2篇
  1982年   3篇
  1981年   4篇
  1979年   1篇
  1977年   1篇
  1976年   2篇
  1975年   2篇
  1974年   1篇
  1973年   1篇
  1971年   1篇
  1970年   1篇
  1968年   1篇
  1967年   1篇
排序方式: 共有108条查询结果,搜索用时 109 毫秒
51.
52.
The content of basic fibroblast growth factor (bFGF) and also interleukins 1β and 6 (IL-1β and IL-6) has been investigated in rat buccal mucosa after its surgical injury by an erbium laser (Er:YAG laser) and a scalpel. The laser emission caused a sharp increase in the content of these regulators on the second day after treatment followed by decrease observed on the seventh day. These results may reflect synergistic effect of these peptide regulators in the wound defect. Changes in time-course of bFGF, IL-1β and IL-6 release in the wound formed by the laser beam compared with the wound induced by the cutting instrument may promote earlier appearance of the proliferation phase.  相似文献   
53.
Yeast strains belonging to the genera Candida and Hansenula were shown to differ in their susceptibility to the action of protein antibiotics produced by the yeasts Williopsis and Zygowilliopsis. This finding can be used as an additional criterion for yeast identification.  相似文献   
54.
Mutations in the Leucine Reach Repeat Kinase 2 (LRRK2) gene are the most frequent cause of familial Parkinson's disease (PD). Although the precise physiological and pathological role of LRRK2 is unclear, a direct link between mutant LRRK2 and apoptosis has been suggested. Using flow cytometric analysis (PI+Annexin V(FITC)) we showed increased spontaneous apoptosis of peripheral blood lymphocytes in patients with LRRK.2-associated PD compared to controls after 24 (P < 0.016) and 48 (P < 0.031 ) h of incubation (5 % CO2, 37 degrees C). We found the increased FAS mRNA level in peripheral blood lymphocytes of patients with LRRK2-associated PD compared to controls (P < 0.05) and to sporadic PD (sPD) (P < 0.002). Significant difference in FAS expression between patients with LRRK2-associated PD and controls remained after three years and was detected after 1 and 24 h during lymphocyte incubation (P < 0.03 and 0.05, respectively). Increased spontaneous lymphocytes apoptosis along to increased FAS expression in patients with LRRK2-associated PD suggest that LRRK2 mutations may lead to the activation of extrinsic apoptotic way.  相似文献   
55.
Possible causes limiting the multiplication of Bordetella phages or inducing their restriction, such as the influence of lysogenic immunity and the restriction-modification (R-M) system or the incompatibility of the receptor apparatus, have been studied. The limitation of the multiplication of phages by some B. bronchiseptica and B. pertussis strains has been shown to be due to the presence of the R-M system and lysogenic immunity. In five B. bronchiseptica strains and two B. pertussis strains site-specific endonucleases (restrictases) with Hind III specificity have been detected. One B. bronchiseptica strain without the R-M system has been detected. B. bronchiseptica strains producing site-specific endonucleases are practically nonpathogenic for humans, grow in common culture media and selectively produce only one restrictase, type Hind III, which guarantees from the admixture of other specific endonucleases. The B. parapertussis strains under study (altogether 100 strains) have not been found to limit the multiplication of Bordetella test phages. The absence of site-specific endonucleases has also been confirmed biochemically. These strains are recommended as indicator strains for the multiplication of Bordetella phages.  相似文献   
56.
The biological activity of the endocrine secretum fraction isolated from the rat duodenum is determined. The fraction with the molecular weight about 3 kDa is found to possess the factor which inhibits the Na+,K+-ATPase activity of enterocytes. It is found that the inhibitory factor secretum depends on the solution which irrigates the duodenum cavity. The possible regulatory role of the intestine inhibitory factor is under discussion.  相似文献   
57.
Aging is accompanied by changes in activity of electron-transport enzyme complexes in myocardial mitochondria of old rats and by increased sensitivity of the mitochondrial permeability transition pore (MPTP) to inductors of its opening (Ca2+ and phenylarsine oxide). We also observed activation of lipid and protein free-radical peroxidation processes. Administration of a complex of biologically active substances that included precursors and modulators of coenzyme Q biosynthesis (α-tocopherol acetate, 4-hydroxybenzoic acid, and methionine) caused the increase in coenzyme Q content, correction of functional activity of mitochondrial electron-transport chain enzyme complexes, the decrease in intensity of lipid and protein free-radical peroxidation in the heart mitochondria and the decrease in sensitivity of mitochondrial permeability transition pore to inductors of its opening. This complex may be recommended for treatment of mitochondrial dysfunction in various pathologies of cardiovascular system, including in aging.  相似文献   
58.
Characteristics of 13 newly isolated thermophilic, anaerobic, and cellulolytic strains were compared with previously described strains of Clostridium thermocellum: ATCC 27405 and JW20 (ATCC 31549). Colony morphology, antibiotic sensitivity, fermentation end-products, and cellulose degradation were documented. All 13 strains were sensitive to erythromycin (5 μg/ml) and chloramphenicol (25 μg/ml), and all strains but one were sensitive to kanamycin (20 μg/ml). Polymerase chain reaction (PCR) amplification using primers based on gene sequences from C. thermocellum ATCC 27405 was successful for all 13 strains in the case of the hydrogenase gene and 11 strains in the case of phosphotransacetylase/acetate kinase genes. Ten strains amplified a product of the expected size with primers developed to be specific for C. thermocellum 16SrRNA primers. Two of the 13 strains did not amplify any product with the PCR primers designed for the phosphotransacetylase/acetate kinase and 16SrRNA primers. A MboI-like GATC- recognizing restriction activity was present in all of the five strains examined. The results of this study have several positive implications with respect to future development of a transformation system for cellulolytic thermophiles. Journal of Industrial Microbiology & Biotechnology (2001) 27, 275–280. Received 12 September 2000/ Accepted in revised form 20 November 2000  相似文献   
59.
60.
The complete gene xylA that encodes endo-1,4--xylanase secreted byPenicillium canescens was cloned and sequenced. The coding region of the gene is separated by eight introns. The protein comprises 302 amino acids of the mature protein and 25 amino acids of the signal peptide. The xylanase of P. canescens belongs to the glycosyl hydrolase family 10. Nucleotide sequences for binding catabolite repression protein CREA and transactivator protein were detected in the promoter region. A set of multicopy strains displaying a seven to eightfold increase in xylanase yield was obtained. The fraction of xylanase in most productive strains amounted to 30–50% of the total secreted protein.  相似文献   
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