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   2858篇
  免费   168篇
  3026篇
  2022年   12篇
  2021年   29篇
  2020年   14篇
  2019年   15篇
  2018年   26篇
  2017年   36篇
  2016年   51篇
  2015年   76篇
  2014年   68篇
  2013年   139篇
  2012年   132篇
  2011年   158篇
  2010年   86篇
  2009年   86篇
  2008年   146篇
  2007年   136篇
  2006年   142篇
  2005年   144篇
  2004年   113篇
  2003年   114篇
  2002年   136篇
  2001年   109篇
  2000年   110篇
  1999年   88篇
  1998年   42篇
  1997年   50篇
  1996年   24篇
  1995年   17篇
  1994年   30篇
  1993年   21篇
  1992年   64篇
  1991年   58篇
  1990年   56篇
  1989年   54篇
  1988年   77篇
  1987年   46篇
  1986年   32篇
  1985年   25篇
  1984年   30篇
  1983年   21篇
  1982年   22篇
  1981年   9篇
  1980年   14篇
  1979年   21篇
  1978年   23篇
  1975年   16篇
  1974年   13篇
  1973年   19篇
  1971年   12篇
  1968年   9篇
排序方式: 共有3026条查询结果,搜索用时 15 毫秒
1.
The effect of griseofulvin treatment on the synthesis of cytochrome c oxidase was studied with the liver of the tadpole, Rana catesbeiana. (1) In the liver of tadpole treated with griseofulvin, a ferrochelatase inhibitor, the synthesis of heme a, but not cytochrome c oxidase protein, is inhibited. (2) The apocytochrome c oxidase which is formed in the liver of tadpole treated with griseofulvin is converted to the active holoenzyme by exogenously added heme a.  相似文献   
2.
Bacteriocin sensitivity typing according to the method of Traub (Appl. Microbiol. 1971. 21: 837-840) was carried out on 226 clinical isolates of Serratia marcescens obtained from inpatients at Nagasaki University Hospital during the period from January 1976 to December 1978. The isolates were divided into 16 different bacteriocin types, mainly 26, 4, and 9. The distribution of the types suggests that Serratia marcescens infections may be caused by cross infection. Reproducibility of bacteriocin typing and the relationship between serotypes (O-antigen) and bacteriocin types are discussed in regard to the application of this method to the study of nosocomial infections.  相似文献   
3.
4.
T Goto  T Watanabe  A Endo 《Teratology》1985,31(3):425-427
When pregnant mice were fed biotin-deficient diets, cleft palate occurred more frequently in male fetuses than in female fetuses. Possible underlying mechanisms are speculated on, and some methodological problems in the analysis of sex-related differences in multiparous animals are discussed.  相似文献   
5.
6.
Juvenile three-spined stickleback Gasterosteus aculeatus in their nursery pond had a bimodal length distribution after October in their first year of life. A sea-run migration of all individuals belonging to the lower modal group was observed, with a peak in early November. These data suggest that partial migration based on the early status of individual juveniles occurs in the Pacific Ocean form of three-spined stickleback.  相似文献   
7.
N Goto 《Stain technology》1987,62(5):305-315
This paper describes a new series of staining methods which can discriminatively demonstrate every structure of the nervous system, including axons and capillaries, in animal and human materials. Methods described in this paper consist of one primary stain, luxol fast blue-periodic acid Schiff-hematoxylin (LPH) and six different subsidiary staining methods. The LPH triple stain can precisely differentiate the following structures: neurons (Nissl bodies, cytoplasm, nuclear membrane and nucleolus), various kinds of nuclei (glia, ependyma, endothelium, leucocyte, connective tissue, etc.), myelin sheaths, neuronal processes (axons and dendrites), reacted glial cell bodies (protoplasmic astrocytes, foamy cells, etc.), blood vessels (arteries, veins and capillaries), meninges, intervening connective tissue, erythrocytes, lipofuscin granules, amyloid bodies, and others. Subsidiary staining methods are also described briefly. Applications are discussed in the context of staining technology and neuromorphological research.  相似文献   
8.
Summary The introduction of acrylate resins (Lowicryl K 4M, LR White) into electronmicroscopic immunocytochemistry applied to embedded tissue (post-embedding method) has improved the localization of antigens because of a satisfactory preservation of both ultrastructure and antigenicity of tissues. Here we describe a method that allows double staining of intracellular and membranous determinants in ultrathin sections of nervous tissue and cultures of peripheral nervous system cells. Ultrathin sections of the rat central nervous system fixed on uncoated grids were stained first for MBP selectively on the one face, then the opposite face was stained for GFAP using monoclonal antibodies and indirect immunogold staining method (IGS). Cultured Schwann cells induced to express major histocompatibility complex (MHC) class II antigens were stained for class. H antigens by pre-embedding method then followed by post-embedding IGS for the other intracytopasmic antigens.The Clinical Research Unit for Multiple Sclerosis is supported by Hermann and Lilly Schilling foundation  相似文献   
9.
10.
T Goto  P Macdonald  T Maniatis 《Cell》1989,57(3):413-422
We have identified the regulatory sequences required for the periodic expression of the Drosophila pair rule gene even skipped (eve). We find that the gradually changing pattern of periodic eve expression during early embryogenesis is directed by two distinct regulatory programs. Initially, eve expression in individual stripes is established by different regulatory elements, each of which responds to nonperiodic spatial cues provided, at least in part, by the gap genes. Later, coordinate expression of eve in all seven stripes is directed by a single regulatory region that responds to periodic cues provided by primary pair rule genes, including eve itself. As a consequence of this two-step regulatory program, eve functions both in the establishment of the periodic pattern of gene expression and in the subsequent specification of parasegmental boundaries.  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