全文获取类型
收费全文 | 392篇 |
免费 | 25篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 13篇 |
妇产科学 | 5篇 |
基础医学 | 43篇 |
口腔科学 | 24篇 |
临床医学 | 53篇 |
内科学 | 115篇 |
皮肤病学 | 3篇 |
神经病学 | 6篇 |
特种医学 | 74篇 |
外科学 | 19篇 |
综合类 | 18篇 |
预防医学 | 22篇 |
眼科学 | 1篇 |
药学 | 19篇 |
中国医学 | 1篇 |
肿瘤学 | 12篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2016年 | 11篇 |
2015年 | 5篇 |
2014年 | 8篇 |
2013年 | 15篇 |
2012年 | 3篇 |
2011年 | 6篇 |
2010年 | 17篇 |
2009年 | 24篇 |
2008年 | 6篇 |
2007年 | 18篇 |
2006年 | 6篇 |
2005年 | 3篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 2篇 |
2001年 | 6篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 30篇 |
1997年 | 30篇 |
1996年 | 30篇 |
1995年 | 25篇 |
1994年 | 17篇 |
1993年 | 19篇 |
1992年 | 7篇 |
1991年 | 3篇 |
1990年 | 11篇 |
1989年 | 12篇 |
1988年 | 14篇 |
1987年 | 18篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 3篇 |
排序方式: 共有429条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
Studies of proteins that inhibit tissue factor activity have generally been conducted using either an extracted tissue homogenate ("thromboplastin") or tissue factor protein reconstituted into phospholipid vesicles rather than with tissue factor expressed in cell membranes (its physiological environment). In the present study, a human fibroblast cell strain was used to evaluate the effects of lipoprotein associated coagulation inhibitor (LACI), placental anticoagulant protein (PAP), and apolipoprotein A-II (apo A-II) on human tissue factor in cell membranes. LACI was tested from 7.8 to 500 pmol/L on fibroblasts cultured at cell densities ranging from 3,500 to 9,925 cells/well, and caused a progressive inhibition of tissue factor activity. PAP was tested from 3.9 nmol/L to 1 mumol/L at cell densities ranging from 4,500 to 15,400 cells/well and caused up to 83% inhibition of tissue factor activity. Inhibition by these proteins appeared to be influenced by cell density as well as whether the cells were intact or disrupted. Apo A-II, up to 1 mumol/L, did not inhibit the tissue factor activity of intact or disrupted fibroblasts at any cell density examined even though it did inhibit the activity of tissue factor in phospholipid vesicles. Of these inhibitors of tissue factor-dependent activation of factor X, LACI was the most effective in suppressing the generation of factor Xa activity. The effects obtained with apo A-II are clearly dependent on the nature of the tissue factor preparation with which it is tested. The disparity between the inhibitory effect of apo A-II on the activity of tissue factor reconstituted into lipid vesicles and the absence of effect on the activity of tissue factor remaining in cell membranes serves to reemphasize the necessity of reexamining results obtained with model systems using as nearly physiological reagents as possible. 相似文献
5.
Black GF Weir RE Chaguluka SD Warndorff D Crampin AC Mwaungulu L Sichali L Floyd S Bliss L Jarman E Donovan L Andersen P Britton W Hewinson G Huygen K Paulsen J Singh M Prestidge R Fine PE Dockrell HM 《Clinical and diagnostic laboratory immunology》2003,10(4):602-611
We have previously shown that young adults living in a rural area of northern Malawi showed greater gamma interferon (IFN-gamma) responses to purified protein derivatives (PPD) prepared from environmental mycobacteria than to PPD from Mycobacterium tuberculosis. In order to define the mycobacterial species to which individuals living in a rural African population have been exposed and sensitized, we tested T-cell recognition of recombinant and purified antigens from M. tuberculosis (38 kDa, MPT64, and ESAT-6), M. bovis (MPB70), M. bovis BCG (Ag85), and M. leprae (65 kDa, 35 kDa, and 18 kDa) in >600 non-M. bovis BCG-vaccinated young adults in the Karonga District of northern Malawi. IFN-gamma was measured by enzyme-linked immunosorbent assay (ELISA) in day 6 supernatants of diluted whole-blood cultures. The recombinant M. leprae 35-kDa and 18-kDa and purified native M. bovis BCG Ag85 antigens induced the highest percentages of responders, though both leprosy and bovine tuberculosis are now rare in this population. The M. tuberculosis antigens ESAT-6 and MPT64 and the M. bovis antigen MPB70 induced the lowest percentages of responders. One of the subjects subsequently developed extrapulmonary tuberculosis; this individual had a 15-mm-diameter reaction to the Mantoux test and responded to M. tuberculosis PPD, Ag85, MPT64, and ESAT-6 but not to any of the leprosy antigens. We conclude that in this rural African population, exposure to M. tuberculosis or M. bovis is much less frequent than exposure to environmental mycobacteria such as M. avium, which have antigens homologous to the M. leprae 35-kDa and 18-kDa antigens. M. tuberculosis ESAT-6 showed the strongest association with the size of the Mantoux skin test induration, suggesting that among the three M. tuberculosis antigens tested it provided the best indication of exposure to, or infection with, M. tuberculosis. 相似文献
6.
Myosin VIIA gene: heterogeneity of the mutations responsible for Usher syndrome type IB 总被引:8,自引:1,他引:8
Levy G; Levi-Acobas F; Blanchard S; Gerber S; Larget-Piet D; Chenal V; Liu XZ; Newton V; Steel KP; Brown SD; Munnich A; Kaplan J; Petit C; Weil D 《Human molecular genetics》1997,6(1):111-116
Usher syndrome is recognized as the most frequent cause of hereditary
deaf-blindness. Usher syndrome type I (USH1), the most severe form of the
disease, is characterized by profound congenital sensorineural deafness,
constant vestibular dysfunction, and retinitis pigmentosa of prepubertal
onset. This form is genetically heterogeneous and five loci (USH1A-E) have
been mapped thusfar. However, only the gene responsible for USH1 B (which
accounts for approximately 75% of USH1 cases) has been characterized. It
encodes a long-tailed unconventional myosin, myosin VIIA, with a predicted
2215 amino acid sequence. Primers covering the complete myosin VIIA coding
sequence as well as the 3' non coding sequence were designed, allowing
direct sequence analysis of each of the 48 coding exons and flanking splice
sites in seven patients affected by USH1. Four novel mutations were thereby
identified. The possibility should now be considered of a sequence-based
prenatal diagnosis in some of the families affected by this very severe
form of Usher syndrome.
相似文献
7.
8.
9.
10.
Evolutionary silencing of the human elastase I gene (ELA1) 总被引:6,自引:0,他引:6