全文获取类型
收费全文 | 14523篇 |
免费 | 1153篇 |
国内免费 | 106篇 |
专业分类
耳鼻咽喉 | 125篇 |
儿科学 | 377篇 |
妇产科学 | 346篇 |
基础医学 | 2010篇 |
口腔科学 | 385篇 |
临床医学 | 1595篇 |
内科学 | 3075篇 |
皮肤病学 | 266篇 |
神经病学 | 1028篇 |
特种医学 | 877篇 |
外国民族医学 | 17篇 |
外科学 | 1849篇 |
综合类 | 159篇 |
一般理论 | 6篇 |
预防医学 | 1321篇 |
眼科学 | 190篇 |
药学 | 957篇 |
中国医学 | 20篇 |
肿瘤学 | 1179篇 |
出版年
2021年 | 175篇 |
2020年 | 129篇 |
2019年 | 194篇 |
2018年 | 254篇 |
2017年 | 161篇 |
2016年 | 239篇 |
2015年 | 268篇 |
2014年 | 339篇 |
2013年 | 470篇 |
2012年 | 631篇 |
2011年 | 617篇 |
2010年 | 376篇 |
2009年 | 394篇 |
2008年 | 596篇 |
2007年 | 633篇 |
2006年 | 601篇 |
2005年 | 569篇 |
2004年 | 547篇 |
2003年 | 555篇 |
2002年 | 530篇 |
2001年 | 521篇 |
2000年 | 556篇 |
1999年 | 498篇 |
1998年 | 249篇 |
1997年 | 226篇 |
1996年 | 222篇 |
1995年 | 187篇 |
1994年 | 154篇 |
1993年 | 163篇 |
1992年 | 365篇 |
1991年 | 321篇 |
1990年 | 306篇 |
1989年 | 293篇 |
1988年 | 289篇 |
1987年 | 261篇 |
1986年 | 267篇 |
1985年 | 254篇 |
1984年 | 201篇 |
1983年 | 195篇 |
1982年 | 115篇 |
1981年 | 110篇 |
1980年 | 119篇 |
1979年 | 152篇 |
1978年 | 116篇 |
1977年 | 104篇 |
1976年 | 80篇 |
1975年 | 91篇 |
1974年 | 105篇 |
1973年 | 116篇 |
1971年 | 86篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Immunopathology of glomerulonephritis associated with chronic woodchuck hepatitis virus infection in woodchucks (Marmota monax).
下载免费PDF全文
![点击此处可从《The American journal of pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
D. N. Peters H. Steinberg W. I. Anderson W. E. Hornbuckle P. J. Cote J. L. Gerin R. M. Lewis B. C. Tennant 《The American journal of pathology》1992,141(1):143-152
Retrospective analysis of necropsy findings of 705 woodchucks was performed to determine the prevalence and morphology of immune-mediated glomerulonephritis, its relationship to woodchuck hepatitis virus (WHV) infection, and the presence of major WHV antigens. Twenty-six woodchucks had glomerular lesions. Renal tissue of the 26 animals was evaluated histologically and immunohistochemically for immune-mediated glomerulonephritis. Of these 26 animals, immune-mediated glomerulonephritis was diagnosed in six, all of which were chronic WHV carriers. Membranous glomerulonephritis was identified in three animals, two of which also had mesangial proliferation. Host immunoglobulin was present within the mesangium and along capillary loops in all three. Woodchuck hepatitis virus core antigen (WHcAg) was present along capillary loops of two of these animals, one membranous and one mixed, and in the mesangium of all three. Woodchuck hepatitis virus surface antigen (WHsAg) deposition was similar to WHcAg deposition but was only present along capillaries in those animals with mixed nephritis. The remaining three animals had mesangial proliferation. WHsAg and host immunoglobulin deposition were predominately mesangial; WHcAg was not detected. Transmission electron microscopy showed thickening of the capillary loop basement membranes and subepithelial electron-dense deposits in animal one, and deposits in the mesangium in animal six. 相似文献
43.
In order to identify risk factors for preterm birth in singletons, data from a population-based case control survey on the island of Curacao were re-analysed. Both medical and sociodemographic variables were examined. Overall, a history of previous preterm birth and severe hypertension during the index pregnancy were indicators of adverse pregnancy outcome, in terms of preterm birth. The contribution of sociodemographic factors to the risk of preterm birth is relatively low. 相似文献
44.
45.
A comprehensive study of smoking in primary school children in Hong Kong: implications for prevention.
下载免费PDF全文
![点击此处可从《Journal of epidemiology and community health》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J Peters A J Hedley T H Lam C L Betson C M Wong 《Journal of epidemiology and community health》1997,51(3):239-245
STUDY OBJECTIVE: To identify factors associated with smoking behaviour in primary school children in Hong Kong. DESIGN: A cross sectional survey in which both children and parents completed questionnaires. The main outcome measure was the smoking status of the children; and risk factors (knowledge of and attitude to smoking and demographic and socioeconomic background) were identified as predictors of ever/never smoking. SETTING AND SUBJECTS: Altogether 9598 primary school children, aged 8-13 years, and attending 27 schools from two districts in Hong Kong participated. MAIN RESULTS: The prevalence of ever-smoking was 12% (1119)-15% (760) in boys and 7% (359) in girls. It ranged from 3% in 8 year old girls to 52% in 13 year old boys. The factors associated with ever-smoking included the following: being a boy (adjusted odds ratio 2.21; 95% confidence interval 1.89, 2.59), increasing age per year (1.48; 1.40, 1.57), living in Kwai Tsing district (1.29; 1.10, 1.50), having one or more smokers at home (2.07; 1.78, 2.39), and having a father who was not working (1.41; 1.19, 1.67). Children who were ever-smokers had both seen and approved of their friends' smoking (8.79; 5.33, 14.50), had a more positive attitude towards smoking (3.35; 2.21, 5.09), and were more successful in recognising cigarette brand names and logos (1.67; 1.42, 1.96), but they lacked confidence (1.78; 1.32, 2.39). CONCLUSIONS: The influences on child smoking are multifactorial and programmes in Hong Kong are falling to curb them. The control of these risk factors must be incorporated in the smoking prevention policy of Hong Kong and supported by future enforced legislation. 相似文献
46.
47.
D P Griswold M W Trader E Frei W P Peters M K Wolpert W R Laster 《Cancer research》1987,47(9):2323-2327
Alkylating agent-sensitive and -resistant L1210 leukemia cell lines were used to determine the tumor response to dose levels of drugs that exceeded conventional doses up to a factor of 10. Since those dose levels were lethal to the host mice, tumor response was based on the results of in vivo bioassays of spleen and/or tumor from drug-treated and control mice. When mice bearing about 10(8) drug-sensitive leukemic cells were treated with a single, conventional (approximately 10% lethal) dose of cis-diamminedichloroplatinum, L-phenylalanine mustard (melphalan), or 1,3-bis(2-chloroethyl)-1-nitrosourea, 10(1) to 10(4) tumor cells were recovered by bioassay. Treatment at doses that were 2 to 8 times the 10% lethal dose of either of those drugs resulted in no recoverable cells and survival of all bioassay recipient mice. Mice bearing advanced L1210 leukemia resistant to cis-diamminedichloroplatinum (L1210/DDPt), 1,3-bis-(2-chloroethyl)-1-nitrosourea (L1210/BCNU), cyclophosphamide (L1210/CPA), or melphalan(L1210/L-PAM) also were treated with a 10% lethal dose and greater doses of the drug to which the tumor line was resistant. Bioassay results indicated a direct correlation between dose intensity and tumor cell kill, the response being linear. Similarly, when mice with L1210/BCNU were treated with high doses of N-(2-chloroethyl)-N'-(2,6-dioxo-3-piperidinyl)-N-nitrosourea or 1,1',1'-phosphinothioylidynetrisaziridine (thioTEPA) and when mice with L1210/DDPt were treated with cyclophosphamide, an increasing, linear cell kill resulted throughout the high-dose range. Overall, these results indicate that resistance to these alkylating agents can be overcome by dose intensification and that the tumor response is linear in relation to increasing dose level. 相似文献
48.
Invasive pulmonary aspergillosis is characterized by radiological signs allowing a correct diagnosis, including differentiation from pulmonary candidiasis, when they are associated with appropriate clinical symptoms (neutropenia and fever persisting despite broad-spectrum antibiotics). In particular the formation of a pulmonary mycetoma in a previously normal lung is one of these signs. Unlike a simple fungus ball (the saprophytic form of aspergillosis), the rounded density of invasive pulmonary aspergillosis consists of sequestrum of devitalized lung tissue owing to blood vessel invasion by Aspergillus hyphae. This morphologic phenomenon is demonstrated in the present case report and is discussed together with the other roentgenological signs of the invasive aspergillosis. 相似文献
49.
The effect of valproic acid on the distribution of gavaged 65Zn in maternal and embryonic tissue of Sprague-Dawley rats was examined 24 h after gavaging of the drug on d 13 of pregnancy. Valproic acid treatment resulted in a significantly higher retention of 65Zn in maternal liver and lower amounts in uterus, placenta and embryos than in controls. Compared to controls, gel chromatography of maternal liver from valproic acid-treated dams showed higher 65Zn counts associated with a protein peak of molecular weight of 6,500, the approximate molecular weight of the Zn-binding protein metallothionein. These results support the idea that the teratogenicity of valproic acid is in part due to an induction of embryonic Zn deficiency secondary to a drug-induced sequestering of Zn into maternal liver that results in a decrease in maternal plasma Zn and subsequent reduction in embryonic Zn uptake. 相似文献
50.