全文获取类型
收费全文 | 124670篇 |
免费 | 8231篇 |
国内免费 | 454篇 |
专业分类
耳鼻咽喉 | 1631篇 |
儿科学 | 3295篇 |
妇产科学 | 2071篇 |
基础医学 | 15993篇 |
口腔科学 | 2370篇 |
临床医学 | 12546篇 |
内科学 | 26356篇 |
皮肤病学 | 1916篇 |
神经病学 | 11968篇 |
特种医学 | 4292篇 |
外国民族医学 | 4篇 |
外科学 | 18006篇 |
综合类 | 1889篇 |
现状与发展 | 1篇 |
一般理论 | 167篇 |
预防医学 | 11115篇 |
眼科学 | 2913篇 |
药学 | 8700篇 |
2篇 | |
中国医学 | 172篇 |
肿瘤学 | 7948篇 |
出版年
2023年 | 512篇 |
2022年 | 831篇 |
2021年 | 2073篇 |
2020年 | 1228篇 |
2019年 | 2014篇 |
2018年 | 2318篇 |
2017年 | 1788篇 |
2016年 | 1958篇 |
2015年 | 2416篇 |
2014年 | 3442篇 |
2013年 | 5336篇 |
2012年 | 7764篇 |
2011年 | 8285篇 |
2010年 | 4690篇 |
2009年 | 4511篇 |
2008年 | 7972篇 |
2007年 | 8518篇 |
2006年 | 8356篇 |
2005年 | 8639篇 |
2004年 | 8171篇 |
2003年 | 8004篇 |
2002年 | 7573篇 |
2001年 | 1183篇 |
2000年 | 940篇 |
1999年 | 1235篇 |
1998年 | 1703篇 |
1997年 | 1426篇 |
1996年 | 1162篇 |
1995年 | 1150篇 |
1994年 | 943篇 |
1993年 | 961篇 |
1992年 | 755篇 |
1991年 | 706篇 |
1990年 | 671篇 |
1989年 | 625篇 |
1988年 | 575篇 |
1987年 | 543篇 |
1986年 | 544篇 |
1985年 | 662篇 |
1984年 | 832篇 |
1983年 | 830篇 |
1982年 | 1162篇 |
1981年 | 1052篇 |
1980年 | 950篇 |
1979年 | 464篇 |
1978年 | 575篇 |
1977年 | 547篇 |
1976年 | 449篇 |
1975年 | 408篇 |
1974年 | 365篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
11.
Kit Galvin Jen Krenz Marcy Harrington Pablo Palmández Richard A. Fenske 《Journal of agromedicine》2016,21(1):113-122
Development of the Practical Solutions for Pesticide Safety guide used participatory research strategies to identify and evaluate solutions that reduce pesticide exposures for workers and their families and to disseminate these solutions. Project principles were (1) workplace chemicals belong in the workplace, and (2) pesticide handlers and farm managers are experts, with direct knowledge of production practices. The project’s participatory methods were grounded in self-determination theory. Practical solutions were identified and evaluated based on five criteria: practicality, adaptability, health and safety, novelty, and regulatory compliance. Research activities that had more personal contact provided better outcomes. The Expert Working Group, composed of farm managers and pesticide handlers, was key to the identification of solutions, as were farm site visits. Audience participation, hands-on testing, and orchard field trials were particularly effective in the evaluation of potential solutions. Small work groups in a Regional Advisory Committee provided the best direction and guidance for a “user-friendly” translational document that provided evidence-based practical solutions. The “farmer to farmer” format of the guide was endorsed by both the Expert Working Group and the Regional Advisory Committee. Managers and pesticide handlers wanted to share their solutions in order to “help others stay safe,” and they appreciated attribution in the guide. The guide is now being used in educational programs across the region. The fundamental concept that farmers and farmworkers are innovators and experts in agricultural production was affirmed by this study. The success of this process demonstrates the value of participatory industrial hygiene in agriculture. 相似文献
12.
13.
14.
Epistaxis is a common ear, nose and throat emergency. A variety of nasal packs are available to control the bleeding by tamponade. Training of junior doctors to insert nasal packs is difficult when dealing with a bleeding patient. We discovered a readily available and simple model to enable trainees to learn the method of nasal packing. 相似文献
15.
16.
17.
Previously, we have demonstrated that chronic-alcohol exposure alters insulin-like growth factor 1 (IGF1) signaling in adult rat heart cells. This report examines the effects of alcohol in vitro on the expression of protein kinase C (PKC) alpha, delta, and epsilon using the embryonic heart cell line, H9c2, and how this may be linked to changes in IGF1 signal transduction. Western blot analyses of H9c2 protein preparations demonstrate that there are significant increases in the total protein levels of PKC delta and epsilon after 4 days exposure to alcohol, and similar increases were found after 2 and 6 days exposure. In addition, there was a significant increase in PKC delta and epsilon in the membranal fractions and a decrease in the cytosolic fractions. No change was found in the expression or activity levels for PKC alpha. Chronic-alcohol exposure (100 mM, 4 days) increased the basal tyrosine kinase activity of the IGF1 receptor (IGF1R), and altered its rate of activation. Chronic-alcohol exposure also reduced the rate of Erk1/Erk2 activation by IGF1. Chronic alcohol blocked the proliferative effects of IGF1 on cell growth and reduced cell viability both in the presence and absence of IGF1, and this alcohol-induced reduction in cell viability was blocked using siRNA to inhibit PKC delta. In addition, a reduction in the amount of myosin light chain 2 was found in the alcohol-exposed cells. In conclusion, chronic alcohol alters PKC delta and epsilon expression and activity, and suppresses the IGF1 signaling pathway in embryonic heart cell culture. Blockage of PKC delta expression using siRNA inhibits the suppressive effects of alcohol on cell viability. 相似文献
18.
Severe persistent asthma can have a substantial impact on a patient's health-related quality of life (HRQL), both as a result of symptoms and from side effects of treatment. The HRQL impact of two doses (400 and 800 microg twice daily) of mometasone furoate dry powder inhaler (MF DPI) was compared with placebo in patients with severe persistent asthma previously maintained on oral steroids as a component of a previously published randomized, 12-week, double-blind, placebo-controlled, multicenter trial. A 9-month open-label extension (OLE), with all patients treated with MF DPI, followed. Patients 12 years of age or older completed a generic HRQL measure, the Medical Outcomes Trust Short Form-36 (SF-36), and an asthma-specific measure, the Marks Asthma Quality of Life Questionnaire (AQLQ-M), at baseline, at endpoint (last evaluable visit) of the double-blind phase (EODBP), and after the first 3 months of the OLE. Of 132 patients enrolled in the study, 128 provided HRQL data at baseline and at EODBP. Mean SF-36 scores at baseline showed significant HRQL impairment compared with U.S. general population norms. With treatment, the reduction in oral corticosteroid (OCS) requirements of the MF-DPI-treated groups was accompanied by significant (p < 0.05) improvement over placebo in the physical domain of HRQL (SF-36 physical component summary score and the physical function subscale) at EODBP. MF-DPI-treated patients also showed significant improvements at EODBP in each of the four subscales of the AQLQ-M (p<0.05). From EODBP to the OLE 3-month endpoint, patients treated with MF DPI twice daily maintained, or improved, SF-36 scores in most domains. Symptomatic improvement and reduction in OCS use with MF DPI were accompanied by significant improvement in HRQL in patients with severe persistent asthma. These improvements were maintained during the 3-month period of the OLE in which HRQL was evaluated. 相似文献
19.
Anne Pavy-Le Traon Richard L Hughson Claire Thalamas Monique Galitsky Nelly Fabre Olivier Rascol Jean-Michel Senard 《Movement disorders》2006,21(12):2122-2126
Patients with multiple system atrophy (MSA) present large changes in blood pressure (BP) due to autonomic disturbances. We analyzed how this change may influence dynamic cerebral autoregulation (DCA). Simultaneous recordings of arterial BP (Finapres) and middle cerebral artery (MCA) blood flow velocity (BFV) (transcranial Doppler) were performed in 10 patients with MSA (61 +/- 12 yr of age) and 12 healthy volunteers (61 +/- 11 yr of age): cerebral BFV response to oscillations in mean BP was studied in the supine position by cross-spectral analysis of mean BP and mean MCA BFV. The DCA was also studied during the decrease in BP the first seconds when standing up from a sitting position by the assessment of the cerebrovascular resistance index (CR; mean BP/mean MCA BFV ratio). The MCA BFV/BP cross-spectral analysis showed a phase for the mid-frequency band (0.07-0.2 Hz) significantly larger in MSA, suggesting more active autoregulation in response to larger changes in BP. Changes in CR reflecting the rate of autoregulation, when standing did not differ between the two groups. These data suggest that dynamic cerebral autoregulation is preserved in MSA. 相似文献
20.