全文获取类型
收费全文 | 409篇 |
免费 | 18篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 30篇 |
妇产科学 | 5篇 |
基础医学 | 76篇 |
口腔科学 | 4篇 |
临床医学 | 47篇 |
内科学 | 115篇 |
皮肤病学 | 11篇 |
神经病学 | 10篇 |
特种医学 | 58篇 |
外科学 | 26篇 |
综合类 | 17篇 |
预防医学 | 13篇 |
眼科学 | 4篇 |
药学 | 16篇 |
肿瘤学 | 12篇 |
出版年
2022年 | 6篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 8篇 |
2014年 | 12篇 |
2013年 | 17篇 |
2012年 | 7篇 |
2011年 | 14篇 |
2010年 | 19篇 |
2009年 | 22篇 |
2008年 | 21篇 |
2007年 | 24篇 |
2006年 | 10篇 |
2005年 | 8篇 |
2004年 | 3篇 |
2003年 | 8篇 |
2002年 | 7篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 10篇 |
1998年 | 13篇 |
1997年 | 15篇 |
1996年 | 19篇 |
1995年 | 9篇 |
1994年 | 19篇 |
1993年 | 15篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 15篇 |
1988年 | 6篇 |
1987年 | 10篇 |
1986年 | 15篇 |
1985年 | 12篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 10篇 |
1980年 | 7篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 6篇 |
1975年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有445条查询结果,搜索用时 31 毫秒
1.
2.
3.
Promoting clinically effective practice: general practitioners' awareness of sources of research evidence 总被引:3,自引:1,他引:2
Prescott K; Lloyd M; Douglas HR; Haines A; Humphrey C; Rosenthal J; Watt I 《Family practice》1997,14(4):320-323
BACKGROUND: Practitioners are being encouraged to base their clinical
practice on research evidence. In order to do this, they must be aware of
and use the sources of evidence. METHODS: A questionnaire survey was
undertaken to establish GPs' awareness of research evidence in their
clinical practice and, in fundholding practices, its influence on
purchasing plans. Questionnaires were sent to 360 lead fundholders in North
Thames Region and 440 of a random sample of the remaining general
practitioners in the region for comparison. RESULTS: Questionnaires were
returned by 62% of lead fundholders and 63% of GPs in the random sample.
There was limited use of the electronic sources of clinical effectiveness.
There was greater reported awareness of published sources of research
evidence and fundholding GPs were significantly more likely to have
referred to publications summarizing research evidence. CONCLUSIONS: GPs
seem to make more use of published clinical effectiveness sources than the
electronic databases. Consequently, they need educational and technical
support if they are to make full use of the available sources of research
evidence available in other media.
相似文献
4.
5.
Liver-infiltrating T helper cells in autoimmune chronic active hepatitis stimulate the production of autoantibodies against the human asialoglycoprotein receptor in vitro. 总被引:2,自引:0,他引:2 下载免费PDF全文
H. L
HR U. TREICHEL T. PORALLA M. MANNS K. H. MEYER ZUM BÜSCHENFELDE B. FLEISCHER 《Clinical and experimental immunology》1992,88(1):45-49
Autoantibodies against the human asialoglycoprotein receptor (ASGPR) occur in the sera of patients with autoimmune liver disorders. Liver-infiltrating T cell clones that specifically recognize the ASGPR have been described in patients with autoimmune chronic active hepatitis (AI-CAH) and primary biliary cirrhosis (PBC). Recently, we have shown that peripheral blood mononuclear cells (PBMC) from patients with AI-CAH or PBC but not chronic viral hepatitis secreted anti-ASGPR antibodies in vitro. In this study we characterized the influence of liver-infiltrating T cells on the secretion of ASGPR-specific autoantibodies by autologous B cells in cell culture supernatants. T cell clones from liver biopsies of three patients with chronic autoimmune liver disorders (one with AI-CAH, two with PBC) were isolated and investigated for their proliferative response to soluble ASGPR and their helper function provided to autoantibody-secreting B lymphocytes. PBMC from these patients secreted autoantibodies spontaneously in their cell culture supernatants and showed a proliferative response to ASGPR. T cell-depleted PBMC, however, lacked spontaneous antibody secretion. Four CD4+CD8- liver-infiltrating T cell clones showed a proliferative response to ASGPR and also induced spontaneous anti-ASGPR antibody production in cell culture supernatants when added to autologous T cell depleted PBMC. Activated supernatants of these T cell clones failed to induce antibody production. None of seven CD4+CD8- and two CD4-CD8+ T cell clones non-responding to ASGPR provided this help for antibody secretion. Anti-ASGPR secretion in vitro could not be inhibited by the addition of MoAbs raised against monomorphic determinants on HLA class II molecules. The addition of purified ASGPR or polyclonal-activating pokeweed mitogen showed no influence on the production of autoantibodies in these cultures. These data show that B lymphocytes require T cell help for the production of ASGPR-specific antibodies. This help can be provided by ASGPR-responsive T helper cells via cellular interactions. 相似文献
6.
Summary. Iris yellow spot virus (IYSV), a tentative virus species in the genus Tospovirus and family Bunyaviridae, is considered a rapidly emerging threat to onion production in the western United States (US). The present study was undertaken
to determine the sequence diversity of IYSV isolates from infected onion plants grown in California, Colorado, Idaho, Oregon,
Utah and Washington. Using primers derived from the small RNA of IYSV, the complete sequence of the nucleoprotein (NP) gene
of each isolate was determined and the sequences compared. In addition, a shallot isolate of IYSV from Washington was included
in the study. The US isolates of IYSV shared a high degree of sequence identity (95 to 99%) with one another and to previously
reported isolates. Phylogenetic analyses showed that with the exception of one isolate from central Oregon and one isolate
from California, all the onion and shallot isolates from the western US clustered together. This cluster also included onion
and lisianthus isolates from Japan. A second distinct cluster consisted of isolates from Australia (onion), Brazil (onion),
Israel (lisianthus), Japan (alstroemeria), the Netherlands (iris) and Slovenia (leek). The IYSV isolates evaluated in this
study appear to represent two distinct groups, one of which largely represents isolates from the western US. Understanding
of the population structure of IYSV would potentially provide insights into the molecular epidemiology of this virus. 相似文献
7.
8.
Summary Western blot analysis of several dasheen mosaic virus isolates revealed molecular weight differences among their capsid proteins (CPs). Sequence analysis of the CP gene showed that the CP of isolate TEN was 15 amino acids shorter than that of isolate LA due to a 57-base deletion and a 12-base insertion into the 5 end of the TEN CP gene. Our data suggest that frequent deletions and insertions are responsible for the CP size diversity among DMV isolates.Sequence data presented here are deposited with the GenBank database under the accession number U08124. Florida Agricultural Experiment Station Journal Series No. R-03574. 相似文献
9.
One hundred patients undergoing abdominal surgery were included in this prospective study. The role of local application of Betadine, use of synthetic sutures, and use of low pressure subcutaneous suction drainage were evaluated in preventing post-operative wound infection. The infection rate was 15 per cent with Betadine, 15.4 per cent with prolene, 20 per cent with subcutaneous suction drainage and 30.8 per cent in the control group.KEY WORDS: Surgical wound infection, Betadine, Sutures, Infection control 相似文献
10.
FJ Cowan JT Warner FD Dunstan WD Evans JW Gregory HR Jenkins 《Archives of disease in childhood》1997,76(4):325-329
The prevalence of osteopenia in children with inflammatory bowel disease (IBD) is unknown. The effect of nutritional state, disease activity, and steroid therapy on bone mineral content (BMC) of whole body, lumbar spine, and left femoral neck measured by dual energy x ray absorptiometry in 32 children with IBD was assessed by comparison with 58 healthy local school children. Using the control data, a predicted BMC was calculated taking into account bone area, age, height, weight, and pubertal stage. The measured BMC in children with IBD was expressed as a percentage of this predicted value (% BMC). Mean (SD) % BMC was significantly reduced for the whole body and left femoral neck in the children with IBD (97.0 (4.5)% and 93.1 (12.0)% respectively, p < 0.05). Of the children with IBD, 41% had a % BMC less than 1 SD below the mean for the whole body and 47% at the femoral neck. Reduction in % BMC was associated with steroid usage but not with the magnitude of steroid dose, disease activity, or biochemical markers of bone metabolism. In conclusion, osteopenia is relatively common in childhood IBD and may be partly related to the previous use of steroids. 相似文献