全文获取类型
收费全文 | 14344篇 |
免费 | 1345篇 |
国内免费 | 1篇 |
出版年
2023年 | 71篇 |
2022年 | 112篇 |
2021年 | 373篇 |
2020年 | 186篇 |
2019年 | 241篇 |
2018年 | 307篇 |
2017年 | 272篇 |
2016年 | 427篇 |
2015年 | 729篇 |
2014年 | 801篇 |
2013年 | 996篇 |
2012年 | 1104篇 |
2011年 | 1175篇 |
2010年 | 724篇 |
2009年 | 599篇 |
2008年 | 854篇 |
2007年 | 846篇 |
2006年 | 720篇 |
2005年 | 692篇 |
2004年 | 637篇 |
2003年 | 522篇 |
2002年 | 491篇 |
2001年 | 134篇 |
2000年 | 117篇 |
1999年 | 128篇 |
1998年 | 117篇 |
1997年 | 97篇 |
1996年 | 81篇 |
1995年 | 104篇 |
1994年 | 83篇 |
1993年 | 78篇 |
1992年 | 78篇 |
1991年 | 70篇 |
1990年 | 82篇 |
1989年 | 76篇 |
1988年 | 61篇 |
1987年 | 74篇 |
1986年 | 55篇 |
1985年 | 46篇 |
1984年 | 91篇 |
1983年 | 67篇 |
1982年 | 69篇 |
1981年 | 62篇 |
1980年 | 53篇 |
1978年 | 50篇 |
1977年 | 43篇 |
1976年 | 46篇 |
1974年 | 51篇 |
1973年 | 46篇 |
1970年 | 43篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Zhaolin Wang Cara Fraley Adam R. Mezo 《Bioorganic & medicinal chemistry letters》2013,23(5):1253-1256
The neonatal Fc receptor, FcRn, prolongs the half-life of IgG in the serum and represents a potential therapeutic target for the treatment of autoimmune disease. Small molecules that block the protein–protein interactions of human IgG–human FcRn may lower pathogenic autoantibodies and provide effective treatment. A novel class of quinoxalines has been discovered as antagonists of the IgG:FcRn protein–protein interaction through optimization of a hit derived from a virtual ligand-based screen. 相似文献
3.
4.
Plant and Soil - Cracks and biopores in compacted soil such as plough pans could aid deep rooting, mitigating constraints to seasonal upland use of paddy fields for rice production. This research... 相似文献
5.
6.
7.
Pinealectomy or radical sham pinealectomy were performed on adult golden-mantled ground squirrels,Spermophilus (=Citellus) lateralis, approximately 1 month prior to the date of normal winter emergence. The first hibernatory period and subsequent active season were not different in either of the operated groups from intact animals. However, although the initiation of the second hibernatory period was not affected in the pinealectomized animals, this group failed to show the progressive increase in the length of heterothermic bouts that is characteristic of normal hibernation. Also, terminal arousal occurred approximately 6 weeks earlier in the second year after pinealectomy. Male squirrels showed a corresponding time compression in their annual gonadal cycle, as was assessed by testicular state.These results suggest that the pineal gland of the golden-mantled ground squirrel is involved in the expression of the annual hibernatory cycle. In the absence of the pineal gland the adult of this species is unable to sustain the normal depth and duration of hibernation in the second over-wintering period following pinealectomy.We have carried out additional experiments with young, laboratory-bornS. lateralis and with field-caught, adultS. richardsonii. The results of these studies also are described in this paper.Presented at the Ninth International Congress of Biometeorology, 23 Sept – 1 Oct 1981, Osnabrück and Hohenheim, FRG. 相似文献
8.
Hierarchy and monophyly 总被引:1,自引:0,他引:1
9.
Eliot C. Bush Anne E. Clark Chris M. DeBoever Lillian E. Haynes Sidra Hussain Singer Ma Matthew M. McDermott Adam M. Novak John S. Wentworth 《PloS one》2012,7(11)
A significant proportion of enzymes display cooperativity in binding ligand molecules, and such effects have an important impact on metabolic regulation. This is easiest to understand in the case of positive cooperativity. Sharp responses to changes in metabolite concentrations can allow organisms to better respond to environmental changes and maintain metabolic homeostasis. However, despite the fact that negative cooperativity is almost as common as positive, it has been harder to imagine what advantages it provides. Here we use computational models to explore the utility of negative cooperativity in one particular context: that of an inhibitor binding to an enzyme. We identify several factors which may contribute, and show that acting together they can make negative cooperativity advantageous. 相似文献
10.
A Adam J Damas P Franchimont 《Comptes rendus des séances de la Société de biologie et de ses filiales》1980,174(5):856-862
A radioimmunoassay for low molecular weight (LMW) human Kininogen has been carried out. The first step was to prepare LMW Kininogen from human plasma. The proposed method allowed to get chemically pure and biologically active LMW Kininogen. This preparation was used to induce antibody. Optimal conditions for labelling and incubation were determined. This method may be applied to the assay of Kininogen in human plasma. 相似文献