全文获取类型
收费全文 | 1673篇 |
免费 | 150篇 |
国内免费 | 15篇 |
专业分类
儿科学 | 116篇 |
妇产科学 | 13篇 |
基础医学 | 191篇 |
口腔科学 | 46篇 |
临床医学 | 211篇 |
内科学 | 422篇 |
皮肤病学 | 11篇 |
神经病学 | 113篇 |
特种医学 | 220篇 |
外科学 | 116篇 |
综合类 | 73篇 |
预防医学 | 118篇 |
眼科学 | 2篇 |
药学 | 79篇 |
肿瘤学 | 107篇 |
出版年
2021年 | 7篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 14篇 |
2017年 | 8篇 |
2016年 | 18篇 |
2015年 | 19篇 |
2014年 | 28篇 |
2013年 | 36篇 |
2012年 | 44篇 |
2011年 | 48篇 |
2010年 | 35篇 |
2009年 | 49篇 |
2008年 | 58篇 |
2007年 | 73篇 |
2006年 | 71篇 |
2005年 | 65篇 |
2004年 | 65篇 |
2003年 | 46篇 |
2002年 | 33篇 |
2001年 | 50篇 |
2000年 | 40篇 |
1999年 | 50篇 |
1998年 | 50篇 |
1997年 | 55篇 |
1996年 | 52篇 |
1995年 | 46篇 |
1994年 | 36篇 |
1993年 | 34篇 |
1992年 | 46篇 |
1991年 | 45篇 |
1990年 | 50篇 |
1989年 | 43篇 |
1988年 | 55篇 |
1987年 | 51篇 |
1986年 | 58篇 |
1985年 | 43篇 |
1984年 | 28篇 |
1983年 | 21篇 |
1982年 | 32篇 |
1981年 | 21篇 |
1980年 | 31篇 |
1979年 | 16篇 |
1978年 | 21篇 |
1977年 | 29篇 |
1976年 | 18篇 |
1975年 | 18篇 |
1974年 | 8篇 |
1972年 | 12篇 |
1970年 | 7篇 |
排序方式: 共有1838条查询结果,搜索用时 0 毫秒
91.
Antibodies to tumor necrosis factor alpha prevent increases in cell replication in liver due to the potent peroxisome proliferator, WY- 14,643 总被引:7,自引:6,他引:7
Bojes HK; Germolec DR; Simeonova P; Bruccoleri A; Schoonhoven R; Luster MI; Thurman RG 《Carcinogenesis》1997,18(4):669-674
Several structurally dissimilar hypolipidemic drugs, plasticizers and
halogenated hydrocarbons induce peroxisomes in hepatocytes, and cause
hepatocellular adenoma and carcinoma in rats and mice. The mechanism by
which these agents act is unknown, although recent studies have suggested a
link between increased cell proliferation and hepatic cancer caused by
peroxisome proliferators. Here, we demonstrate that neutralizing antibodies
to tumor necrosis factor alpha (TNF alpha) block increases in protein
kinase C and cell proliferation due to [4-
chloro-6-(2,3-xylidino)-2-pyrimidinylthio]acetic acid (WY-14,643), a
hypolipidemic drug and potent peroxisome proliferator that causes tumors.
WY-14,643 moderately elevated the level of TNF alpha mRNA in the liver. TNF
alpha was detected immunohistochemically exclusively in Kupffer cells.
These results demonstrate that WY-14,643 acts as an indirect mitogen on
hepatocytes via TNF alpha. We propose that the Kupffer cell, a major source
of TNF alpha in the liver, is involved in the mechanism of the mitogenic
effect of WY-14,643.
相似文献
92.
Evaluation of attempted prevention of unexpected infant death in very high-risk infants by planned health care 总被引:1,自引:0,他引:1
Three hundred and ninety-six babies born in Sheffield between 1982 and 1990 identified as being at "very high risk" of unexpected infant death by means of a scoring system, received an intensive programme of health care including a case discussion between a paediatrician, the GP and the health visitor held in the family doctor's surgery, weekly visits from the health visitor and informal hospital admission. Significantly fewer sudden unexpected infant deaths occurred in this group than were expected by logistic regression anlysis or occurred in the best available control group with comparable scores ( p = 0.024). Problems in evaluation include identification of an adequate control population, ethical difficulties in introducing a controlled study when the programme is already perceived as effective, and the calculation of "expected death rates". The results of this study indicate that very energetic programmes of intervention may prevent some deaths in vulnerable infants. 相似文献
93.
PJ Fielder SE Gargosky M Vaccarello K Wilson P Cohen F Diamond J Guevara-Aguirre AL Rosenbloom RG Rosenfeld 《Acta paediatrica (Oslo, Norway : 1992)》1993,82(S389):40-43
Six adult patients with growth hormone receptor deficiency (GHRD) (2 men, 4 women) with an identical defect in the growth hormone receptor (GHR) gene, were treated with recombinant human insulin-like growth factor I (IGF-I), 40 μgikg S.C. twice daily, for 7 days. Serum concentrations of IGF peptide and IGF binding protein-3 (IGFBP-3) were measured by specific radioimmunoassays; serum IGFBPs were also measured by Western ligand blotting. The size distribution of both IGF-I and IGF-II was measured in serum following size-exclusion fast-performance liquid chromatography. IGF-I treatment resulted in a normalization of serum IGF-I levels on days 1–7 of treatment and a decrease in serum IGF-II levels. The fall in IGF-II levels and the simultaneous rise in IGF-I levels, however, resulted in an unchanged total serum IGF level. The low IGFBP-3 values did not significantly change during treatment, whereas there was a slight increase in IGFBP-2 levels. Preliminary analysis of size-fractionated sera suggested an increase in IGF-I levels in the 40 and 150 kDa regions at the expense of IGF-II levels. The results suggest that despite the failure of IGF-I treatment to increase IGFBPs significantly, serum IGFBP concentrations were sufficient to maintain normal levels of IGF-I. 0 Laron syndrome, growth hormone receptor deficiency, insulin-like growth factors, insulin-like growth factor binding protein 相似文献
94.
95.
96.
97.
Subclinical inflammatory activity may be one of the factors which influences the variable natural history of farmers' lung. Serum lysozyme (LYS) and angiotensin converting enzyme (ACE) have been measured in 52 farmers with a previous history of farmers' lung and in 51 healthy control farmers. The group with farmers' lung assessed during the winter, although having had no recent acute symptoms, had significantly higher levels of LYS and ACE compared to both healthy control farmers seen in winter and farmers' lung subjects seen in summer. There was a mild but significant negative correlation between LYS and farm size in the farmers' lung subjects assessed in winter. The results suggest that active inflammation may be present in subjects with farmers' lung in the absence of acute symptoms during the season when dust exposure occurs as the result of feeding cattle. 相似文献
98.
Cardiovascular effects of morphine, pethidine, diamorphine and nalorphine on the cat and rabbit 总被引:1,自引:0,他引:1 下载免费PDF全文
H. F. Grundy 《British journal of pharmacology》1971,42(2):159-178
1. The predominant effect of morphine, diamorphine, pethidine or nalorphine on the blood pressure of the anaesthetized cat or rabbit is hypotension although, occasionally, a pressor action may predominate or intervene.2. Possible mechanisms of the depressor phases of action have been studied on cardiac and vascular preparations both in situ and in vitro.3. While in the whole animal, catecholamine release from the adrenal medulla and histamine liberation may be implicated in the responses, the vasodilator and vascular relaxant actions of morphine and, probably, pethidine, nalorphine and diamorphine on the isolated preparations are not mediated by the liberation of known peripheral transmitters or autacoids or by interaction with their specific receptors. 相似文献
99.
100.