全文获取类型
收费全文 | 83420篇 |
免费 | 6207篇 |
国内免费 | 258篇 |
专业分类
耳鼻咽喉 | 985篇 |
儿科学 | 2116篇 |
妇产科学 | 1216篇 |
基础医学 | 11202篇 |
口腔科学 | 925篇 |
临床医学 | 8936篇 |
内科学 | 17746篇 |
皮肤病学 | 927篇 |
神经病学 | 7976篇 |
特种医学 | 3173篇 |
外科学 | 13362篇 |
综合类 | 1015篇 |
一般理论 | 92篇 |
预防医学 | 6465篇 |
眼科学 | 1993篇 |
药学 | 5715篇 |
中国医学 | 107篇 |
肿瘤学 | 5934篇 |
出版年
2023年 | 685篇 |
2022年 | 1067篇 |
2021年 | 2470篇 |
2020年 | 1402篇 |
2019年 | 2264篇 |
2018年 | 2577篇 |
2017年 | 1851篇 |
2016年 | 1942篇 |
2015年 | 2287篇 |
2014年 | 3305篇 |
2013年 | 4178篇 |
2012年 | 6730篇 |
2011年 | 6991篇 |
2010年 | 3784篇 |
2009年 | 3335篇 |
2008年 | 5514篇 |
2007年 | 5779篇 |
2006年 | 5373篇 |
2005年 | 5293篇 |
2004年 | 4805篇 |
2003年 | 4408篇 |
2002年 | 3967篇 |
2001年 | 719篇 |
2000年 | 534篇 |
1999年 | 681篇 |
1998年 | 830篇 |
1997年 | 627篇 |
1996年 | 508篇 |
1995年 | 456篇 |
1994年 | 423篇 |
1993年 | 426篇 |
1992年 | 357篇 |
1991年 | 294篇 |
1990年 | 253篇 |
1989年 | 233篇 |
1988年 | 234篇 |
1987年 | 204篇 |
1986年 | 198篇 |
1985年 | 220篇 |
1984年 | 231篇 |
1983年 | 200篇 |
1982年 | 264篇 |
1981年 | 261篇 |
1980年 | 206篇 |
1979年 | 140篇 |
1978年 | 143篇 |
1977年 | 121篇 |
1976年 | 98篇 |
1975年 | 92篇 |
1974年 | 84篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
Myths about heroin abound. They are now the basis of internationaland national policies and of widespread misery. This book tracestheir development and carefully deconstructs them, aiming primarilyto give accurate informationnot to 相似文献
63.
K Daly G S Giebink P B Batalden R S Anderson C T Le B Lindgren 《The Pediatric infectious disease journal》1991,10(7):500-506
This double blind, placebo-controlled trial was designed to determine whether intervention with a stepped regimen of trimethoprim-sulfamethoxazole (TMP-SMX) and prednisone would prevent high risk children from developing chronic otitis media with effusion (OME) and recurrent acute otitis media. Forty-two children were enrolled, assigned to treatment with active drug or placebo and then examined at 2-week intervals. They received TMP-SMX (or placebo) during the first 2 weeks, TMP-SMX and prednisone (or placebo) during Weeks 3 and 4 for persistent OME and TMP-SMX (or placebo) for Weeks 5 and 6 if OME was still unresolved. After treatment 48% of active drug and 14% of placebo subjects resolved OME bilaterally (P less than 0.05). Active drug subjects also had fewer acute otitis media episodes than placebo subjects while receiving study treatment (P less than 0.01). Although this treatment regimen produced short term OME resolution, long term benefits were not demonstrated. 相似文献
64.
65.
Kay Teschke Susan M. Kennedy Andrew F. Olshan 《American journal of industrial medicine》1994,26(3):327-337
During an exposure monitoring study, 78 saw maintenance tradesmen were randomly assigned to be interviewed about their exposures using one of two questionnaire formats: open-ended and partly prompted questions about five categories of materials; and detailed prompting about 75 agents. The more open-ended questionnaire elicited fewer exposure responses overall, but more responses about agents not included on the detailed questionnaire. Composite materials and trade name products were more frequently cited as exposures than individual metals or compounds. Validity of responses was ascertained using air measurements (individual metals) or observations of the employees (composite materials). Sums of sensitivities and specificities were very low (near 1.0) for most of the metals for both types of questionnaire. For composite materials, validity improved substantially. Sensitivities with the partly prompted format (0.44–0.85) were always lower than with detailed prompting (0.80–1.00). Specificities were usually, but not always, higher with partial prompting (0.66–0.92) than with detailed prompting (0.18–0.86). Selection of questionnaire format for an epidemiologic study would depend on the likely prevalence of exposure in controls and the effects of trade-offs in sensitivity and specificity. 相似文献
66.
67.
68.
Eric M Cheng Andrew Siderowf Kari Swarztrauber Mahmood Eisa Martin Lee Barbara G Vickrey 《Movement disorders》2004,19(2):136-150
Parkinson's disease (PD) is a major cause of disability. To date, there have been no large-scale efforts to measure the quality of PD care because of a lack of quality indicators for conducting an explicit review of PD care processes. We present a set of quality indicators for PD care. Based on a structured review of the medical literature, 79 potential indicators were drafted. Through a two-round modified Delphi process, an expert panel of seven movement disorders specialists rated each indicator on criteria of validity, feasibility, impact on outcomes, room for improvement, and overall utility. Seventy-one quality indicators met validity and feasibility thresholds. Applying thresholds for impact on outcomes, room for improvement, and overall utility, a subset of 29 indicators was identified, spanning dopaminergic therapy, assessment of functional status, assessment and treatment of depression, coordination of care, and medication use. Multivariable analysis showed that overall utility ratings were driven by validity and impact on outcomes (P < 0.01). An expert panel can reach consensus on a set of highly rated quality indicators for PD care, which can be used to assess quality of PD care and guide the design of quality improvement projects. 相似文献
69.
Shelby D Reed Peter W Dillingham Andrew H Briggs David L Veenstra Sean D Sullivan 《Medical decision making》2003,23(3):252-264
Pharmacy and therapeutics committees commonly cite a lack of generalizability as a reason for not incorporating cost-effectiveness information into decision making. To address this concern, many committees undertake site-specific economic evaluations, which are often limited by small sample sizes and nonrandomized designs. We show how 2 complementary approaches were used to minimize these limitations in an economic evaluation of abciximab at 1 institution. Using a propensity score methodology, we selected patients who did not receive abciximab for the comparison cohort. Then, we adopted a Bayesian, hierarchical, random-effects model to integrate site-specific and clinical trial data. We applied the posterior distributions of effectiveness with local cost data in a traditional decision-analytic model. In 74% of the simulations, abciximab was cost-effective at 1 institution at the $50,000 per life year saved threshold, assuming a 50:50 split of patients undergoing coronary stenting and angioplasty. Among patients undergoing coronary stenting, the cost-effectiveness ratio of the addition of abciximab was at or below the $50,000 per life year saved threshold in 66.0% of the simulations. 相似文献
70.
Paul P. Dillon Stephen J. Daly John G. Browne Bernadette M. Manning Elma Loomans Aart Van Amerongen Richard O'Kennedy 《Food and Agricultural Immunology》2003,15(3):225-234
Public concern surrounding antibiotic contamination in food and food products has made it imperative to develop analytical methods for their detection. Polyclonal antibodies were used in the development of a surface plasmon resonance (SPR)-based inhibition immunoassay for cephalexin. A conjugate consisting of cephalexin-bovine serum albumin (BSA) was immobilized on the dextran gel surface of the sensor chip. Binding/regeneration studies of antibody to immobilized cephalexin were studied and dissociation of the antibody from the immobilized cephalexin was easily achieved with 10 mmol l-1 NaOH. Forty surface regeneration cycles were carried out and found to be reproducible with only a 7.4% decrease in binding over this number of regenerations. Model inhibition immunoassays for cephalexin were developed in PBS and spiked milk samples with detection ranges of 4.88 to 2,500 ng ml-1 and 244 to 3,906 pg ml-1, respectively. 相似文献