全文获取类型
收费全文 | 68822篇 |
免费 | 6779篇 |
国内免费 | 42篇 |
出版年
2021年 | 816篇 |
2020年 | 511篇 |
2019年 | 628篇 |
2018年 | 817篇 |
2017年 | 734篇 |
2016年 | 1316篇 |
2015年 | 2209篇 |
2014年 | 2542篇 |
2013年 | 3279篇 |
2012年 | 4271篇 |
2011年 | 4231篇 |
2010年 | 2825篇 |
2009年 | 2585篇 |
2008年 | 3685篇 |
2007年 | 3902篇 |
2006年 | 3716篇 |
2005年 | 3489篇 |
2004年 | 3561篇 |
2003年 | 3421篇 |
2002年 | 3227篇 |
2001年 | 833篇 |
2000年 | 658篇 |
1999年 | 923篇 |
1998年 | 967篇 |
1997年 | 739篇 |
1996年 | 615篇 |
1995年 | 633篇 |
1994年 | 624篇 |
1993年 | 668篇 |
1992年 | 729篇 |
1991年 | 634篇 |
1990年 | 629篇 |
1989年 | 616篇 |
1988年 | 601篇 |
1987年 | 600篇 |
1986年 | 594篇 |
1985年 | 650篇 |
1984年 | 758篇 |
1983年 | 681篇 |
1982年 | 769篇 |
1981年 | 816篇 |
1980年 | 775篇 |
1979年 | 553篇 |
1978年 | 570篇 |
1977年 | 541篇 |
1976年 | 486篇 |
1975年 | 441篇 |
1974年 | 486篇 |
1973年 | 464篇 |
1972年 | 332篇 |
排序方式: 共有10000条查询结果,搜索用时 171 毫秒
1.
2.
3.
Widespread occurrence of AP in amyloidotic tissues. An immunohistochemical observation 总被引:1,自引:0,他引:1
T Shirahama M Skinner J D Sipe A S Cohen 《Virchows Archiv. B, Cell pathology including molecular pathology》1985,48(3):197-206
Plasma (P)-component of amyloid (AP or SAP), while not an integral part of the amyloid fibril, has been considered to be intimately associated with virtually every different type of amyloid. In the present study, we evaluated the distribution of AP in the organs frequently involved in two forms of human systemic amyloidosis (AA and AF) and in mouse AA amyloidosis, by use of immunohistochemistry with anti-AP. Although the amyloid deposits generally showed moderate reactions with anti-AP, they were not always clearly distinguished from the surrounding non-amyloid tissue elements which often stained as well. The basement membrane often showed even stronger reaction to anti-AP than the adjacent amyloid deposits, and liver sections demonstrated such a high overall reaction to anti-AP that the anti-AP reaction on the amyloid deposits was often obscurred. The present results suggest that the binding between AP and the amyloid fibril may not be monospecific, that AP by this technique occurs rather widely throughout the body, and therefore that anti-AP may not be considered as specific a marker for amyloid deposits in immunohistochemical and perhaps other studies as well. 相似文献
4.
5.
6.
Wendy A. Douglass Robert H. Hyland Christopher D. Buckley Aymen Al-Shamkhani Jacqueline M. Shaw Sarah L. Scarth David L. Simmons S.K.Alex Law 《FEBS letters》1998,440(3):125
The cysteine-rich region (CRR) of the β2 integrin subunit was replaced by that of β1 to give the chimera β2NV1. β2NV1 can combine with αL to form a variant leukocyte-function-associated antigen (LFA)-1 on COS cell surface, suggesting that the specificity of the β2 interaction with αL does not lie in the CRR. Unlike those expressing wild-type LFA-1, COS cells expressing αLβ2NV1 are constitutively active in intercellular adhesion molecule (ICAM)-1 adhesion. These results suggest that activation of LFA-1 involves the release of an intramolecular constraint, which is maintained, in part, by the authentic β2 CRR. 相似文献
7.
Grape thaumatin-like proteins (TLPs) play roles in plant-pathogen interactions and can cause protein haze in white wine unless removed prior to bottling. Different isoforms of TLPs have different hazing potential and aggregation behavior. Here we present the elucidation of the molecular structures of three grape TLPs that display different hazing potential. The three TLPs have very similar structures despite belonging to two different classes (F2/4JRU is a thaumatin-like protein while I/4L5H and H2/4MBT are VVTL1), and having different unfolding temperatures (56 vs. 62°C), with protein F2/4JRU being heat unstable and forming haze, while I/4L5H does not. These differences in properties are attributable to the conformation of a single loop and the amino acid composition of its flanking regions. 相似文献
8.
9.
Robert S. Steneck 《Current biology : CB》2009,19(3):R117-R119
10.