全文获取类型
收费全文 | 1528122篇 |
免费 | 95053篇 |
国内免费 | 2916篇 |
专业分类
耳鼻咽喉 | 21056篇 |
儿科学 | 47309篇 |
妇产科学 | 41961篇 |
基础医学 | 208280篇 |
口腔科学 | 41447篇 |
临床医学 | 125460篇 |
内科学 | 295929篇 |
皮肤病学 | 31110篇 |
神经病学 | 123746篇 |
特种医学 | 62837篇 |
外国民族医学 | 435篇 |
外科学 | 240547篇 |
综合类 | 33785篇 |
现状与发展 | 6篇 |
一般理论 | 440篇 |
预防医学 | 110625篇 |
眼科学 | 34231篇 |
药学 | 110779篇 |
4篇 | |
中国医学 | 3623篇 |
肿瘤学 | 92481篇 |
出版年
2018年 | 34625篇 |
2017年 | 27875篇 |
2016年 | 31694篇 |
2015年 | 12934篇 |
2014年 | 17617篇 |
2013年 | 26128篇 |
2012年 | 40032篇 |
2011年 | 56548篇 |
2010年 | 39832篇 |
2009年 | 32307篇 |
2008年 | 54701篇 |
2007年 | 61050篇 |
2006年 | 37869篇 |
2005年 | 38959篇 |
2004年 | 39510篇 |
2003年 | 39973篇 |
2002年 | 37211篇 |
2001年 | 64058篇 |
2000年 | 66011篇 |
1999年 | 55645篇 |
1998年 | 14937篇 |
1997年 | 13784篇 |
1996年 | 13116篇 |
1995年 | 12406篇 |
1994年 | 11663篇 |
1992年 | 42891篇 |
1991年 | 41446篇 |
1990年 | 40729篇 |
1989年 | 39673篇 |
1988年 | 37064篇 |
1987年 | 36516篇 |
1986年 | 34991篇 |
1985年 | 33199篇 |
1984年 | 24885篇 |
1983年 | 21118篇 |
1982年 | 12753篇 |
1981年 | 11584篇 |
1979年 | 23994篇 |
1978年 | 17127篇 |
1977年 | 14848篇 |
1976年 | 13446篇 |
1975年 | 15272篇 |
1974年 | 18115篇 |
1973年 | 17569篇 |
1972年 | 16811篇 |
1971年 | 15717篇 |
1970年 | 14949篇 |
1969年 | 14387篇 |
1968年 | 13490篇 |
1967年 | 12015篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
61.
Oga Emmanuel. A. Peters Erica. N. Mark Katrina Trocin Kathleen Coleman-Cowger Victoria. H. 《Maternal and child health journal》2019,23(2):250-257
Maternal and Child Health Journal - Background Prenatal substance use screening is recommended. The 4 P’s Plus screener includes questions on perceived problematic substance use in parents... 相似文献
62.
63.
Elizabeth A. Mosley PhD MPH Amy J. Schulz PhD MPH MSW Lisa H. Harris MD PhD Barbara A. Anderson PhD 《Women & health》2020,60(7):806-820
ABSTRACT Abortion is legal in South Africa, but negative abortion attitudes remain common and are poorly understood. We used nationally representative South African Social Attitudes Survey data to analyze abortion attitudes in the case of fetal anomaly and in the case of poverty from 2007 to 2016 (n = 20,711; ages = 16+). We measured correlations between abortion attitudes and these important predictors: religiosity, attitudes about premarital sex, attitudes about preferential hiring and promotion of women, and attitudes toward family gender roles. Abortion acceptability for poverty increased over time (b = 0.05, p < .001), but not for fetal anomaly (b = ?0.008, p = .284). Highly religious South Africans reported lower abortion acceptability in both cases (Odds Ratio (OR)anomaly = 0.85, p = .015; ORpoverty = 0.84, p = .02). Premarital sex acceptability strongly and positively predicted abortion acceptability (ORanomaly = 2.63, p < .001; ORpoverty = 2.46, p < .001). Attitudes about preferential hiring and promotion of women were not associated with abortion attitudes, but favorable attitudes about working mothers were positively associated with abortion acceptability for fetal anomaly ((ORanomaly = 1.09, p = .01; ORpoverty = 1.02, p = .641)). Results suggest negative abortion attitudes remain common in South Africa and are closely tied to religiosity, traditional ideologies about sexuality, and gender role expectations about motherhood. 相似文献
64.
ABSTRACTA monocausal bacteriological understanding of infectious disease orients tuberculosis control efforts towards antimicrobial interventions. A bias towards technological solutions can leave multistranded public health and social interventions largely neglected. In the context of globalising biomedical approaches to infectious disease control, this ethnography-inspired review article reflects upon the implementation of rapid diagnostic technology in low- and middle-income countries. Fieldwork observations in Vietnam provided a stimulus for a critical review of the global rollout of tuberculosis diagnostic technology. To address local needs in tuberculosis control, health managers in resource-poor settings are readily cooperating with international donors to deploy novel diagnostic technologies throughout national tuberculosis programme facilities. Increasing investment in new diagnostic technologies is predicated on the supposition that these interventions will ameliorate disease outcomes. However, suboptimal treatment control persists even when accurate diagnostic technologies are available, suggesting that promotion of singular technological solutions can distract from addressing systemic change, without which disease susceptibility, propagation of infection, detection gaps, diagnostic delays, and treatment shortfalls persist. 相似文献
65.
66.
67.
Worsening pneumonitis due to a pharmacokinetic drug–drug interaction between everolimus and voriconazole in a renal transplant patient 下载免费PDF全文
68.
Konrad Matyja Anna Małachowska-Jutsz Anna K. Mazur Kazimierz Grabas 《Ecotoxicology (London, England)》2016,25(5):924-939
Dehydrogenase activity is frequently used to assess the general condition of microorganisms in soil and activated sludge. Many studies have investigated the inhibition of dehydrogenase activity by various compounds, including heavy metal ions. However, the time after which the measurements are carried out is often chosen arbitrarily. Thus, it can be difficult to estimate how the toxic effects of compounds vary during the reaction and when the maximum of the effect would be reached. Hence, the aim of this study was to create simple and useful mathematical model describing changes in dehydrogenase activity during exposure to substances that inactivate enzymes. Our model is based on the Lagergrens pseudo-first-order equation, the rate of chemical reactions, enzyme activity, and inactivation and was created to describe short-term changes in dehydrogenase activity. The main assumption of our model is that toxic substances cause irreversible inactivation of enzyme units. The model is able to predict the maximum direct toxic effect (MDTE) and the time to reach this maximum (TMDTE). In order to validate our model, we present two examples: inactivation of dehydrogenase in microorganisms in soil and activated sludge. The model was applied successfully for cadmium and copper ions. Our results indicate that the predicted MDTE and TMDTE are more appropriate than EC50 and IC50 for toxicity assessments, except for long exposure times. 相似文献
69.
As countries implement Article 11 of the World Health Organization (WHO) Framework Convention on Tobacco Control, graphic warning labels that use images of people and their body parts to illustrate the consequences of smoking are being added to cigarette packs. According to exemplification theory, these case examples—exemplars—can shape perceptions about risk and may resonate differently among demographic subpopulations. Drawing on data from eight focus groups (N = 63) with smokers and nonsmokers from vulnerable populations, this qualitative study explores whether people considered exemplars in their reactions to and evaluations of U.S. graphic health warning labels initially proposed by the Food and Drug Administration. Participants made reference to prior and concurrent mass media messages and exemplars during the focus groups and used demographic cues in making sense of the images on the warning labels. Participants were particularly sensitive to age of the exemplars and how it might affect label effectiveness and beliefs about smoking. Race and socioeconomic status also were salient for some participants. We recommend that exemplars and exemplification be considered when selecting and evaluating graphic health warnings for tobacco labels and associated media campaigns. 相似文献
70.
best practice onkologie - 相似文献