全文获取类型
收费全文 | 11597篇 |
免费 | 993篇 |
国内免费 | 2篇 |
专业分类
12592篇 |
出版年
2022年 | 97篇 |
2021年 | 164篇 |
2020年 | 128篇 |
2019年 | 167篇 |
2018年 | 208篇 |
2017年 | 186篇 |
2016年 | 280篇 |
2015年 | 472篇 |
2014年 | 474篇 |
2013年 | 681篇 |
2012年 | 795篇 |
2011年 | 745篇 |
2010年 | 501篇 |
2009年 | 468篇 |
2008年 | 629篇 |
2007年 | 678篇 |
2006年 | 614篇 |
2005年 | 605篇 |
2004年 | 597篇 |
2003年 | 592篇 |
2002年 | 653篇 |
2001年 | 155篇 |
2000年 | 118篇 |
1999年 | 154篇 |
1998年 | 163篇 |
1997年 | 160篇 |
1996年 | 145篇 |
1995年 | 122篇 |
1994年 | 108篇 |
1993年 | 111篇 |
1992年 | 115篇 |
1991年 | 94篇 |
1990年 | 80篇 |
1989年 | 82篇 |
1988年 | 68篇 |
1987年 | 58篇 |
1986年 | 52篇 |
1985年 | 60篇 |
1984年 | 76篇 |
1983年 | 67篇 |
1982年 | 98篇 |
1981年 | 94篇 |
1980年 | 75篇 |
1979年 | 64篇 |
1978年 | 60篇 |
1977年 | 57篇 |
1976年 | 58篇 |
1975年 | 42篇 |
1974年 | 41篇 |
1973年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
W J Allard C D Cheli D L Morris J Goldblatt Y Pierre L Kish Y Chen J Dai R L Vessella D W Chan M K Schwartz Z Zhou K K Yeung 《The International journal of biological markers》1999,14(2):73-83
We conducted a multicenter evaluation of the analytical and clinical performance of the automated Bayer Immuno 1 complexed PSA (cPSA) assay, and compared assay performance to the Bayer Immuno 1 PSA assay. We sought to determine whether measurements of cPSA could be of clinical utility in the management of patients with prostate cancer. Results of the 10-day imprecision across three evaluation sites produced total CV < 2.50% and an analytical sensitivity of 0.02 microgram/L. There was an increased trend in clinical sensitivity for prostate cancer with increasing stage of disease (71-86%). Clinical specificity for patients with benign urogenital disease was 74.8%, and for other nonprostate diseases ranged from 91.1-100%. Retrospective serial monitoring of 155 patients with prostate cancer demonstrated concordance of cPSA measurements to clinical status for 97% of the patients analyzed. Results from the clinical studies using the Bayer Immuno 1 cPSA assay were comparable to results obtained with the Bayer Immuno 1 PSA assay. The Bayer Immuno 1 cPSA assay demonstrates analytical performance and clinical effectiveness in the management of prostate cancer patients during the course of disease and therapy. 相似文献
12.
Phillip A. Morin 《Conservation Genetics》2000,1(3):271-275
13.
14.
Role of different lymphoid tissues in the initiation and maintenance of DNA-raised antibody responses to the influenza virus H1 glycoprotein. 下载免费PDF全文
Antibody responses in mice immunized by a single gene gun inoculation of plasmid expressing the influenza virus H1 hemagglutinin and in mice immunized by a sublethal H1 influenza virus infection have been compared. Both immunizations raised long-lived serum responses that were associated with the localization of antibody-secreting cells (ASC) to the bone marrow. However, the kinetics of these responses were 4 to 8 weeks slower in the DNA-immunized than in the infection-primed mice. Following a gene gun booster, the presence of ASC in the inguinal lymph nodes, but not in other lymph nodes, revealed gene gun responses being initiated in the nodes that drain the skin target site. Both pre- and postchallenge, the DNA-immunized mice had 5- to 10-times-lower levels of antibody and ASC than the infection-primed mice. 相似文献
15.
Using the imidate procedure, 2,3,4,6-tetra-O-benzyl-1-O-(N-methylacetimidoyl)-β-d-galactopyranose was condensed with various monosaccharides to provide, in good yield and with high stereoselectivity, α-linked disaccharides. 相似文献
16.
17.
Pierre Fellmann Jens Andersen Philippe F. Devaux Marc le Maire Alain Bienvenue 《Biochemical and biophysical research communications》1980,95(1):289-295
A spin labeled fatty acid (16-doxylstearic acid) was linked to a photochemical reacting group (azido derivative). When the molecule is introduced, at a low concentration, into rabbit sarcoplasmic reticulum membranes, the spectrum before illumination is identical to the spectrum obtained with the corresponding spin labeled fatty acid. After illumination, a large immobilized components is seen. It corresponds to about 70% of the ESR signal of the effectively bound label, at room temperature. The fraction of immobilized component varies with temperature, from 100% at 0°C to 50% at 35°C. Addition of a small amount of detergent (dodecyl octaethylene glycol monoether), under non solubilizing conditions, decreases the fraction of signal due to a strongly immobilized probe. A possible interpretation is that the immobilized signal reflects protein bound spin labels trapped in Ca2+ ATPase oligomers, which are partially dissociated by detergent addition or temperature increase. 相似文献
18.
Pierre Bongrand Gilles Bouvenot Robert Bartolin J Jeanne Tatossian Bernard Bruguerolle 《Chronobiology international》1988,5(1):81-83
Eleven male subjects were investigated to detect a possible circadian rhythm of the polymorphonuclear phagocytosis. Both cell activity and serum opsonins were studied for numerical detection of granulocytes having ingested at least one particle and for the mean number of ingested particles per cell. No significant temporal differences (ANOVA and cosinor) were found. 相似文献
19.
20.
Pierre Livet 《PSN》2003,1(1):45-52
Every emotion can be characterized by its temporal dynamics, which also allow emotions to be categorised. Emotions, understood as resulting from the perception of a difference between expectations and the observed consequences of a course of action, are constantly interacting with cognitive processes that underlie these emotions and react to them. This is the case, in particular, for revision processes concerning one’s beliefs. In this view, anxiety can be understood as a signal of a difficulty to revise profoundly one’s beliefs, which explains the tendency to make only small revisions. Resistance to revision (of beliefs or preferences) can also be an indication of one’s values. It is mainly at the level of affective attitudes (with longer temporal scope and requiring deeper revisions) that mental diseases can be observed and can be described from the standpoint of their own strategies of revision. 相似文献