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   172篇
  免费   1篇
  2021年   1篇
  2015年   2篇
  2014年   1篇
  2013年   2篇
  2012年   2篇
  2011年   5篇
  2010年   3篇
  2009年   1篇
  2008年   5篇
  2007年   3篇
  2006年   8篇
  2005年   3篇
  2004年   9篇
  2003年   13篇
  2002年   5篇
  2001年   6篇
  2000年   6篇
  1999年   8篇
  1998年   1篇
  1992年   3篇
  1991年   3篇
  1990年   4篇
  1989年   8篇
  1988年   7篇
  1987年   4篇
  1986年   6篇
  1985年   2篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1981年   1篇
  1979年   5篇
  1978年   1篇
  1977年   1篇
  1976年   3篇
  1975年   5篇
  1974年   8篇
  1973年   8篇
  1972年   2篇
  1971年   4篇
  1970年   2篇
  1968年   1篇
  1966年   5篇
  1965年   2篇
  1960年   1篇
排序方式: 共有173条查询结果,搜索用时 234 毫秒
1.
The behaviour was studied of male mice of CBA/Lac and C57BL/6j lines near transparent perforated partition in reaction to syngeneic partner which was in adjacent department of the common cage. The number of approaches to the partition and total time of staying near it during testing were used as behaviour parameters. Then the partition was removed and the success or defeat of each individual in agonistic collision and parameters of aggressive reaction of the winner male mouse were fixed. It turned out that future winners spent significantly more time near the partition than future losers. By the correlative analysis reliable interconnections were established between individuals activity near the partition (number of approaches or total time of staying) and intensity of aggression (number or total time of attacks) which reflects the level of the aggressive motivation. Variation is observed of individual correlating parameters depending on animals genotype and conditions of their keeping.  相似文献   
2.
3.
Bacteriolytic proteinase L2 is able to cleave fluorogenic synthetic tripeptide anthranoyl-alanyl-alanyl-phenylalanyl-nitroanilide (Abz-Ala-Ala-Phe-pNA) at the bond between phenylalanine and p-nitroaniline. Optimal conditions of the tripeptide cleavage have been determined: pH 6.7 + 0.1; mu = 2 (by NaCl); t = 40 degrees C; KM = 2.6 x 10(-5) M. Metal cations reduced the enzyme activity. The enzyme was inhibited by EDTA, p-CMB, DIF. The synthetic tripeptide can be used to determine the activity of the L2 enzyme.  相似文献   
4.
The relative DNA content of isolated Amoeba proteus nuclei has been measured by cytofluorometry. With the amoeba strain studied, the generation time is roughly equal to 48 hours at 25 degrees C, and with the presence of food in the medium. After the synchronous divisions, amoebae were maintained in the medium either with or without food organisms (Tetrahymena pyriformis). DNA contents in the nuclei of both the amoebae groups were measured within 4 and 48 hours after division. Before 16 hours, the nuclear DNA contents did not differ in either group. Starting from 20 hours, the DNA amount in fed amoebae exceeded that in starved animals. On the whole, the differences in DNA quantity increased by a 48th hour after division, when the nuclei of the former contained 145% DNA of the latter. The results obtained suggest that the DNA synthesis in amoeba nuclei may proceed during the whole interphase, and that during the second half of interphase the content of DNA may depend on the feeding intensity in amoebae. After refeeding the starved animals, DNA contents in their nuclei increased to reach the same level as in the constantly fed amoebae seen in the end of interphase.  相似文献   
5.
6.
A possibility is demonstrated to separate summary lupine leghemoglobins (which are salted out within 55--90% of ammonium sulphate saturation) into Lb I and Lb II components by means of ionic exchange chromatography on DEAE-cellulose. Lb I is eluted at lower ionic strength buffer than LbII, and differs from the latter in the form and the size of crystals. Both components have the same electrophoretic mobility and contain N-terminal glycine. LbII and LbI precipitate under gradual salting out within 55--75% and 78--90% of saturation respectively.  相似文献   
7.
The study deals with a comparative analysis of the relative abundances of the carbon isotopes 12C and 13C in the metabolites and biomass of the Burkholderia sp. BS3702 and Pseudomonas putida BS202-p strains capable of utilizing aliphatic (n-hexadecane) and aromatic (naphthalene) hydrocarbons as sources of carbon and energy. The isotope composition of the carbon dioxide, biomass, and exometabolites produced during the growth of Burkholderia sp. BS3702 on n-hexadecane (delta 13C = -44.6 +/- 0.2@1000) were characterized by the isotope effects delta 13CCO2 = -50.2 +/- 0.4@1000, delta 13Cbiom = -46.6 +/- 0.4@1000 and delta 13Cexo = -41.5 +/- 0.4@1000, respectively. The isotope composition of the carbon dioxide, biomass, and exometabolites produced during the growth of the same bacterial strain on naphthalene (delta 13C = -21 +/- 0.4@1000) were characterized by the isotope effects delta 13CCO2 = -24.1 +/- 0.4@1000, delta 13Cbiom = -19.2 +/- 0.4@1000 and delta 13Cexo = -19.1 +/- 0.4@1000, respectively. The possibility of using the isotope composition of metabolic carbon dioxide for the rapid monitoring of the microbial degradation of petroleum hydrocarbons in the enviroment is discussed.  相似文献   
8.
Using cytophotometric method, the content of glycogen was studied in hepatocytes of the portal and central zones of a liver lobule in norm, in cirrhosis, and 1, 3, and 6 months after a partial hepatectomy of the normal and cirrhotic rat liver. As we showed earlier, glycogen content in cirrhotic liver hepatocytes rose 2-3-fold, along with obvious impairment of glycogen metabolic heterogeneity in these. In cirrhotic liver glycogen dominates in the central zone, whereas in norm more glycogen is observed in the portal one. The objective of this study was to find out to what degree a partial hepatectomy of cirrhotic liver may promote recovery of the metabolic glycogen heterogeneity in hepatocytes. Glycogen was determined in hepatocytes, using a quantitative variant of PAS-reaction on sections of the material obtained from serial supravital punctate liver biopsies. Glycogen amount in hepatocytes of different liver lobule zones was determined by an image analyzer technique that allows to bring together the cytophotometric analysis of the substance with its localization in a particular liver lobule. Results of these studies have shown that a partial hepatectomy of cirrhotic liver promotes restoration of the hepatocyte metabolic heterogeneity in the liver lobule.  相似文献   
9.
Application of partition test measuring the behavioural activity of animals near the transparent perforated partition (dividing the experimental cage onto two halves) as a reaction to the partner in the neighbouring compartment of common cage, is considered. Behavioural reaction as a response to other individual differs in dependence on psychological and physiological states, social experience, strains of the animals and kinds of partner. Partition test may be productive in experiments studying mechanisms of sociability, anxiety, aggressive and sexual motivations, olfaction, as well as for screening of psychotropic drugs.  相似文献   
10.
The principles of the primary prophylaxis, analogous to the program "Harm Reduction", are presented. The basis for placing this work on broad footing was the rapid assessment of the situation with the use of narcotic drugs in the city (the number of users exceeded 10,000 per 238,000 inhabitants) with a tendency towards a sharp decrease of the age of the users (9-13 years). The experience of work on the training of medical personnel, directly contacting with blood and thus considered to be a risk group, taking into account risky professional behavior (potentially dangerous), was accumulated. The training activities among students of medical schools proved to be effective. They became the best volunteers and leaders among young people. Adolescents aged 14-18 years were enlisted as volunteers: they worked in different places usually attended by young people and invited drug addicts to the anonymous examination room. The role of local mass media in educating the public on of the problems of the prevention of HIV infection is discussed. As a result, the activation of the youth movement in support of the program "Anti-AIDS" and an increase in the number of people in target groups coming to the anonymous examination room are noted.  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