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   4967篇
  免费   0篇
  2021年   1篇
  2018年   2篇
  2017年   1篇
  2015年   1篇
  2013年   1篇
  2012年   189篇
  2011年   349篇
  2010年   146篇
  2009年   2篇
  2008年   308篇
  2007年   422篇
  2006年   449篇
  2005年   431篇
  2004年   451篇
  2003年   487篇
  2002年   474篇
  2001年   299篇
  2000年   514篇
  1999年   262篇
  1998年   34篇
  1997年   13篇
  1992年   7篇
  1991年   15篇
  1990年   13篇
  1989年   14篇
  1988年   13篇
  1987年   11篇
  1986年   14篇
  1985年   9篇
  1984年   8篇
  1983年   4篇
  1982年   1篇
  1981年   1篇
  1979年   3篇
  1977年   4篇
  1976年   1篇
  1975年   1篇
  1974年   2篇
  1973年   3篇
  1972年   1篇
  1971年   1篇
  1969年   1篇
  1968年   1篇
  1966年   2篇
  1965年   1篇
排序方式: 共有4967条查询结果,搜索用时 15 毫秒
1.
The data are provided on the possibility of detecting interindividual polymorphism from the organization of repeated DNA sequences of the alphoid type in human genome. The data were obtained on the basis of the Sothern blotting hybridization method whose efficacy was raised by means of vacuum transfer of DNA from gel to nitrocellulose filters.  相似文献   
2.
Indomethacin and substance BW-755C in experiments on isolated myometrium striae of pregnant white rats exert an inhibiting effect on the contractile uterus function due to inhibition of cyclooxygenase or lipoxygenase ways of the arachidonic acid transformation. Prostaglandin F2 alpha is sensitive to functioning of the cyclooxygenase and lipoxygenase ways of the arachidonic acid transformation, while oxytocin--only lipoxygenase one. Conclusions rest on results from multiparametric analysis of the contractile uterus function suggested by authors and confirmed by the pattern recognition method--the Karunen-Loev orthogonal decomposition.  相似文献   
3.
A multichannel Thomson scattering diagnostics for measuring the plasma parameters in the GOL-3 facility was designed and created at the Budker Institute of Nuclear Physics of the Siberian Division of the Russian Academy of Sciences. The diagnostics operates at the fundamental harmonic of a neodymium laser (1.06 μm) and allows one to perform measurements over a wide range of electron temperatures and densities with high spatial and time resolutions. A special multipulse oscillator is developed that makes it possible to perform up to 20 measurements of the plasma temperature and density over a period of 300 μs during one shot. The laser used to generate probing radiation, the recording system, and the calibration procedure are described. Results from measurements of the temporal evolution of the plasma density in the GOL-3 in different stages of the discharge are presented to illustrate the system operation. Original Russian Text ? S.V. Polosatkin, A.V. Burdakov, M.V. Ivantsivskiĭ, V.S. Koĭdan, V.K. Ovchar, A.F. Rovenskikh, V.V. Semionov, M.G. Fedotov, 2006, published in Fizika Plazmy, 2006, Vol. 32, No. 2, pp. 128–133.  相似文献   
4.
The dynamics of the formation of postvaccinal immunity after immunization with preparations obtained with the use of hydroxylamine (HA) preparations from Proteus strains of different O serogroups, Salmonella minnesota Re-mutant and the common antimicrobial antigen isolated from Escherichia coli 14 has been studied on mice with Proteus peritonitis-bacteremia used as a model. The study has revealed that intraperitoneal immunization with Proteus HA preparations stimulates the phagocytic activity of peritoneal mononuclear cells in mice and induces an increase in the titers of specific O antibodies. Proteus antigens ensure the formation of anti-Proteus immunity, preventing the death of the animals from peritonitis-bacteremia. The protection of mice from such infection resulting from the injection of the common antigens of gram-negative bacteria is considerably less. These data are indicative of the possibility of using Proteus peritonitis-bacteremia as a model for the study of the protective potency of Proteus vaccines.  相似文献   
5.
Toxin production and the intensity of toxin formation in 265 C. diphtheriae strains circulating in different areas of the USSR have been studied by the method of the enzyme-linked immunosorbent assay (ELISA). This study has been carried out with the use of the assay system consisting of monoclonal antibodies to the COOH-area of the B-fragment of the toxin molecule adsorbed onto the surface of polystyrene plates, affinity-purified polyclonal antidiphtheria antibodies labeled with horse-radish peroxidase and substrate indicator mixture (5-aminosalicylic acid and hydrogen peroxide). Some specific features of using ELISA for the detection of C. diphtheriae toxin directly in liquid culture medium are presented. High sensitivity, specificity and good reproducibility of this method permitting the detection of C. diphtheriae toxin and the determination of the intensity of toxin formation in the C. diphtheriae strains under study are shown. The method may be recommended for practical use at health institutions.  相似文献   
6.
Studied has been the fine structure of the kidney's glomerulus endotheliocyte of man (age 2-6 years) and fish (year-old Atlantic salmon Salmo salar L.), as organisms occupying extreme place in development of kidney in phylogenetic line of the vertebrates. Revealed has been the uniformity of geometric reconstruction of vascular endothelium of kidney's glomerulus of investigated objects under heterogeneous factors' influence (compensatory hyperfunction of man and environment influence of fish). Formation of star-shaped structures with large open fenestrae in its central part (diameter 100-150 nm) both in the local parts of endothelium and in space between them (diameter 250-350 nm) has been observed. Such construction peculiarity sharply increases permeability of capillaries of kidney's glomerulus and thus appears as a characteristic sign of strenuous functional activity of the filtration apparatus of metanephros of man and mesonephros of fish. Revealed reaction of endothelium is considered as universal and nonspecific.  相似文献   
7.
8.
9.
The effect of temperature, nutrition, and density stresses on phenotypic and genetic variation in morphological traits (thorax length, wing length, number of sternopleural and abdominal bristles, and number of arista branches) was examined in Drosophila melanogaster. In addition, the effect of stress on developmental stability measured as fluctuation asymmetry of bilateral traits was analyzed. All of the stresses were shown to increase phenotypic variation and fluctuating asymmetry of bilateral traits. Genetic variation of morphometric traits estimated using the isofemale line technique was higher under stressful than under normal conditions. Biotic and abiotic stresses were similar in their effect on phenotypic and genetic variation. The effect of stress on variability of morphometric traits was generally higher than on that of meristic traits. Possible causes of the increase of genetic variation under stress are discussed.  相似文献   
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