全文获取类型
收费全文 | 15455篇 |
免费 | 1452篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 136篇 |
儿科学 | 482篇 |
妇产科学 | 303篇 |
基础医学 | 1993篇 |
口腔科学 | 318篇 |
临床医学 | 1601篇 |
内科学 | 3389篇 |
皮肤病学 | 144篇 |
神经病学 | 1272篇 |
特种医学 | 466篇 |
外国民族医学 | 1篇 |
外科学 | 2689篇 |
综合类 | 424篇 |
一般理论 | 21篇 |
预防医学 | 1554篇 |
眼科学 | 339篇 |
药学 | 972篇 |
中国医学 | 23篇 |
肿瘤学 | 824篇 |
出版年
2023年 | 118篇 |
2022年 | 155篇 |
2021年 | 349篇 |
2020年 | 203篇 |
2019年 | 311篇 |
2018年 | 377篇 |
2017年 | 303篇 |
2016年 | 290篇 |
2015年 | 365篇 |
2014年 | 479篇 |
2013年 | 730篇 |
2012年 | 888篇 |
2011年 | 976篇 |
2010年 | 592篇 |
2009年 | 477篇 |
2008年 | 819篇 |
2007年 | 910篇 |
2006年 | 829篇 |
2005年 | 804篇 |
2004年 | 758篇 |
2003年 | 720篇 |
2002年 | 675篇 |
2001年 | 289篇 |
2000年 | 271篇 |
1999年 | 268篇 |
1998年 | 196篇 |
1997年 | 154篇 |
1996年 | 120篇 |
1995年 | 131篇 |
1994年 | 119篇 |
1993年 | 104篇 |
1992年 | 212篇 |
1991年 | 212篇 |
1990年 | 198篇 |
1989年 | 155篇 |
1988年 | 152篇 |
1987年 | 136篇 |
1986年 | 147篇 |
1985年 | 150篇 |
1984年 | 142篇 |
1983年 | 118篇 |
1982年 | 103篇 |
1981年 | 90篇 |
1980年 | 85篇 |
1979年 | 103篇 |
1978年 | 108篇 |
1977年 | 75篇 |
1975年 | 78篇 |
1973年 | 90篇 |
1972年 | 89篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Sherry M Bergeron Sheila Cameron Marjorie Armstrong-Stassen Karen Pare 《Revue canadienne de recherche en sciences infirmières》2006,38(2):42-54
The purpose of this study was to enhance our understanding of the influence of the SARS crisis on the work and personal lives of community nurses.A total of 941 community nurses employed in a range of health-care settings in the province of Ontario, Canada, provided qualitative information about their perceptions of the impact of SARS in their workplace and in their personal lives. Themes and subthemes from the data were organized into 2 categories: The Experience (operational, organizational, and personal narratives), and Learning from the Experience (opportunities for personal learning, professional and policy development, and insight into policy and administrative implications). The findings are discussed within a framework of the learning opportunity presented by the crisis at the local, national, and international levels. The roles of effective communication, emergency response coordination, and education are considered with respect to policy development and administrative responses to infectious disease protocol. The findings are particularly relevant at this time of heightened fear of global epidemics. 相似文献
62.
Acute marijuana effects on human risk taking. 总被引:6,自引:0,他引:6
Scott D Lane Don R Cherek Oleg V Tcheremissine Lori M Lieving Cythia J Pietras 《Neuropsychopharmacology》2005,30(4):800-809
Previous studies have established a relationship between marijuana use and risky behavior in natural settings. A limited number of laboratory investigations of marijuana effects on human risk taking have been conducted. The present study was designed to examine the acute effects of smoked marijuana on human risk taking, and to identify behavioral mechanisms that may be involved in drug-induced changes in the probability of risky behavior. Using a laboratory measure of risk taking designed to address acute drug effects, 10 adults were administered placebo cigarettes and three doses of active marijuana cigarettes (half placebo and half 1.77%; 1.77%; and 3.58% Delta9-THC) in a within-subject repeated-measures experimental design. The risk-taking task presented subjects with a choice between two response options operationally defined as risky and nonrisky. Data analyses examined cardiovascular and subjective effects, response rates, distribution of choices between the risky and nonrisky option, and first-order transition probabilities of trial-by-trial data. The 3.58% THC dose increased selection of the risky response option, and uniquely shifted response probabilities following both winning and losing outcomes following selection of the risky option. Acute marijuana administration thereby produced measurable changes in risky decision making under laboratory conditions. Consistent with previous risk-taking studies, shifts in trial-by-trial response probabilities at the highest dose suggested a change in sensitivity to both reinforced and losing risky outcomes. Altered sensitivity to consequences may be a mechanism in drug-induced changes in risk taking. Possible neurobiological sites of action related to THC are discussed. 相似文献
63.
64.
65.
66.
Michael R. Perkin David P. Strachan Hywel C. Williams Cameron T. C. Kennedy Jean Golding the ALSPAC Study Team 《Pediatric allergy and immunology》2004,15(3):221-229
We investigated the natural history of atopic dermatitis (AD) in a population-based birth cohort and assessed whether children at risk of visible eczema at 5 years of age can be identified from total immunoglobulin E (IgE) levels measured at 8, 12 and 18 months. AD data collected included a whole body examination for visible eczema at 49 months (4 years) and 61 months (5 years) of age and parent completed questionnaire data throughout their early lives. Children were divided into four groups based on their natural history of early AD: persistent (AD at 1, 6, 18, 30 and 42 months, n = 34), intermittent early onset (before 18 months of age, n = 495), intermittent late onset (18–42 months of age, n = 273) and unaffected ( n = 429). Visible eczema at 5 years of age was present in 12.2% (117/957) (95% confidence interval [CI] 10.1–14.3%) of the children. Levels of total IgE at 8, 12 and 18 months of age were associated with early onset of AD, but not with AD of later onset. For all four natural history groups, the geometric mean total IgE at 12 months was higher in those who subsequently had visible eczema than those who did not. However, the degree of overlap was such that total IgE at 12 months of age was a poor predictor of eczema at age five. A cutoff point of 78 kU/l had the highest positive predictive value for visible eczema at 5 years of age of 28.6%, with a sensitivity of 12% and specificity of 95%. 相似文献
67.
68.
69.
70.
Steven C. Cunningham M.D. Farin Kamangar M.D. M.P.H. Min P. Kim M.D. Sommer Hammoud Raqeeb Haque Anirban Maitra M.B.B.S. Elizabeth Montgomery M.D. Richard E. Heitmiller M.D. F.A.C.S. Michael A. Choti M.D. F.A.C.S. Keith D. Lillemoe M.D. F.A.C.S. John L. Cameron M.D. F.A.C.S. F.R.C.S. F.R.C.S.I. Charles J. Yeo M.D. F.A.C.S. Richard D. Schulick M.D. F.A.C.S. 《Journal of gastrointestinal surgery》2005,9(5):718-725
Gastric adenocarcinoma is the second leading cause of cancer death worldwide. In Western series, survival rates vary widely
and are generally lower than those reported from Eastern series. We performed a retrospective analysis of cases operated on
at the Johns Hopkins Hospital over the past 18 years and collected data on demographics, tumor characteristics, pathologic
stage, treatment methods, complications, survival time, and other relevant factors. Survival according to stage of disease,
Lauren tumor type, tumorlocation,time period, andadministration of adjuvant therapy wasanalyzed, andresultswerecompared with
those of other Western series. During this period, 436 patients with gastric adenocarcinoma underwent resection. We have shown
a statistically significant association between survival and margin status, stage of disease, and Lauren tumor type. Overall
5-year survival was 26%, and 5-year survival after R0 resection was 33%. No significant difference was detected between survival
and tumor location, time period of treatment, or administration of adjuvant therapy. Analysis of various Western series reveals
major differences between the cohorts under study, such as stage of disease, extent of resection, tumor type, and tumor location.
Many of the reported differences among Western series may be due to cohort differences, such as stage of disease, extent of
resection, tumor type, and tumor location. 相似文献