全文获取类型
收费全文 | 937篇 |
免费 | 51篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 22篇 |
妇产科学 | 30篇 |
基础医学 | 92篇 |
口腔科学 | 8篇 |
临床医学 | 94篇 |
内科学 | 222篇 |
皮肤病学 | 10篇 |
神经病学 | 164篇 |
特种医学 | 7篇 |
外科学 | 54篇 |
综合类 | 13篇 |
一般理论 | 3篇 |
预防医学 | 103篇 |
眼科学 | 19篇 |
药学 | 62篇 |
中国医学 | 2篇 |
肿瘤学 | 53篇 |
出版年
2023年 | 8篇 |
2022年 | 6篇 |
2021年 | 38篇 |
2020年 | 20篇 |
2019年 | 36篇 |
2018年 | 36篇 |
2017年 | 17篇 |
2016年 | 22篇 |
2015年 | 28篇 |
2014年 | 30篇 |
2013年 | 60篇 |
2012年 | 53篇 |
2011年 | 64篇 |
2010年 | 34篇 |
2009年 | 24篇 |
2008年 | 61篇 |
2007年 | 55篇 |
2006年 | 43篇 |
2005年 | 33篇 |
2004年 | 32篇 |
2003年 | 41篇 |
2002年 | 34篇 |
2001年 | 25篇 |
2000年 | 41篇 |
1999年 | 30篇 |
1998年 | 11篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 11篇 |
1990年 | 9篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 7篇 |
1986年 | 8篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有991条查询结果,搜索用时 31 毫秒
1.
2.
Power density producing damage at a probability of 0.5 (ie, damage threshold, DT-50) was determined for PMMA (with/without UV absorber) and Silicone intraocular lenses. Scattered light from a collinear diagnostic He:Ne beam was one of four damage monitors deployed to enhance the sensitivity of the system. In order of increasing laser resistance the following results were obtained: injection molded PMMA (1.9/GW/cm2) Silicone (2.63 GW/cm2) Lathe-cut PMMA (4.47 GW/cm2), Lathe-cut PMMA with UV absorber (8.32 GW/cm2), Cast-molded PMMA (12.30 GW/cm2). An analysis of variance revealed interclass differences significant at the .01 level. Cast-molded PMMA was the most laser-resistant IOL material. 相似文献
3.
4.
S. Strada A. Barzaghi A. Piroddi G. Bovo A. Brenna C. Ballabio G. Masera C. Uderzo 《Pediatric hematology and oncology》1994,11(4):427-432
The article describes a relatively rare congenital anomaly that was difficult to diagnose in a 10-year-old child with acute nonlymphoblastic leukemia. Just at diagnosis of leukemia, the patient showed a pathologic chest radiograph because of a parenchymal thickening at the right lung apex. The presence of bronchopneumonia was suspected, and broad-spectrum antibiotic therapy was started with subsequent antifungal treatment for persistent fever and concurrent chemotherapy-induced marrow aplasia, which did not favor pulmonary infiltrate recovery. Continuous culture tests, including bronchial swab, proved negative for Koch-Weeks bacillus, fungal organisms, and other pathogens. Computed tomography, however, was suggestive of Aspergillus lung involvement, and apical sepmentectomy was performed. The anatomic pathologist suggested the diagnosis of intralobar sequestration. In summary, when pulmonary pathology with an excavation is found in a leukemic child, one must consider the possibility of pulmonary sequestration complicated by an infectious disease. 相似文献
5.
Damodaran Shivashankar Bullock Brenna Ekwenna Obi Nayebpour Mehdi Koizumi Naoru Sindhwani Puneet Ortiz Jorge 《International urology and nephrology》2021,53(3):439-446
International Urology and Nephrology - Delayed graft function (DGF) is a manifestation of acute kidney injury uniquely framed within the transplant process and a predictor of poor long-term graft... 相似文献
6.
7.
Economic evaluation of pharmaceuticals: a European perspective 总被引:1,自引:0,他引:1
Drummond M Rutten F Brenna A Pinto CG Horisberger B Jönsson B Le Pen C Rovira J von der Schulenburg MG Sintonen H 《PharmacoEconomics》1993,4(3):173-186
In recent years there has been a large increase in the number of economic evaluations of pharmaceuticals. Many of these studies have been commissioned by individual pharmaceutical companies, in support of new or existing products. In 2 countries, Australia and Canada (in the province of Ontario), draft guidelines issued by the government have outlined the requirements for economic evaluations to be submitted in support of requests for reimbursement (government subsidy) of particular products. One consequence of the guidelines is that they clarify what is required, and in specifying the procedure for submission of dossiers, identify a clear audience for the economic evaluation. In contrast, the situation in Europe is diverse. A wide range of healthcare systems exist, including national health services and more liberal systems, involving a wide range of insurers and providers. European countries also differ widely in their approach to the pricing and reimbursement of pharmaceuticals. Because of this diversity, the nature, conduct and impact of economic evaluation in Europe is not clear. It is therefore difficult for pharmaceutical companies to develop appropriate strategies for economic evaluation and for analysts to decide on appropriate study methodology. This article reviews the nature of any official guidance or requirements for economic evaluation, the potential for use of economic evaluation, the range of studies carried out and the identifiable impacts. There is currently no official guidance in any country, although some countries are considering issuing guidelines. In some countries there is official encouragement to pharmaceutical companies to undertake studies, and where economic data have been presented they have been considered by the relevant committees. The potential uses of economic evaluation vary widely from country to country. These can be classified in terms of a potential role in undertaking national price negotiations, deciding on reimbursement status or copayment level, deciding on inclusion in local formularies or in treatment guidelines, or in improving prescribing decisions. Approximately 80 economic evaluations of pharmaceutical products have been conducted to date in Europe, covering a wide range of clinical areas. There are relatively few examples of identifiable effects of such studies. In part this is because it is often difficult to assess the part played by various items of data. Nevertheless, the overriding conclusion is that economic evaluation of medicines is likely to be more relevant in Europe in the future. The problem for the pharmaceutical industry is in determining when and how. 相似文献
8.
The multidisciplinary treatment of a case of bilateral dental fusion of the upper central incisors with maxillary constriction, crowding, and palatal inversion of one of the lateral incisors is reported. The rarity with which this anomaly appears, along with its complex characteristics, often make it extremely difficult to treat. It requires the involvement of different specialists to find the most suitable treatment for each individual patient. CLINICAL SIGNIFICANCE: This particular case of bilateral dental fusion required the involvement of orthodontists, periodontists, endodontists, and restorative specialists. For the individual evaluation of these extremely complex cases, the esthetic and functional results to be reached must be assessed compared to treatment times and biologic and economical costs. The long-term prognoses of these complex therapies also must be borne in mind. 相似文献
9.
Whitaker SB Singh BB Weller RN Bath KR Loushine RJ 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》1999,87(2):233-237
OBJECTIVE: The purpose of this study was to determine whether the dental pulp and lesions of pulpal origin (eg, pulp polyps, periapical granulomas, and periapical cysts) exhibit receptors for the sex steroid hormones estrogen, progesterone, and androgen. STUDY DESIGN: Staining for the receptors of the hormones estrogen, progesterone, and androgen was accomplished through use of available immunohistochemical detection techniques. Pulpal tissues were obtained from freshly extracted human third molars; the other tissues were obtained from the Oral and Maxillofacial Pathology Laboratory archives. Ten samples of each tissue were processed and immunostained for these specific receptors. RESULTS: Staining for estrogen and androgen receptors was essentially negative for all cell populations examined. However, positive progesterone receptor staining of varying degrees was noted in 8 of 10 pulpal specimens. Primarily, pulpal fibroblasts and odontoblasts exhibited positive immunoreactivity. CONCLUSIONS: The results of this study suggest that although the dental pulp may be a potential target tissue for progesterone, evidence is lacking with respect to the other sex steroid hormones. 相似文献
10.
Low-molecular-weight heparins and heparinoids in acute ischemic stroke : a meta-analysis of randomized controlled trials 总被引:24,自引:0,他引:24
BACKGROUND AND PURPOSE: Low-molecular-weight heparins and heparinoids (LMWHs) are superior to unfractionated heparin in the prevention and treatment of venous thromboembolism and acute coronary syndromes. We performed a systematic review of randomized controlled trials (RCTs) to examine the safety and efficacy of LMWH in acute ischemic stroke. METHODS: Randomized, controlled, and nonconfounded trials of LMWH in acute ischemic stroke were identified from the Cochrane Library (version 2, 1999), previous systematic reviews, and a review of publication quality relating to acute stroke trials. The authors each independently extracted data by treatment group and assessed trial quality using Cochrane Collaboration criteria. RESULTS: Eleven completed RCTs involving 3048 patients were identified; data were available from 10 of these. Four trials explicitly excluded patients with presumed cardioembolic stroke. Treatment with LMWH was associated with significant reductions in prospectively identified deep vein thrombosis (OR 0.27, 95% CI 0.08 to 0.96) and symptomatic pulmonary embolism (OR 0.34, 95% CI 0.17 to 0.69) and with increased major extracranial hemorrhage (OR 2.17, 95% 1.10 to 4.28). Nonsignificant increases in end-of-treatment (OR 1.20, 95% CI 0.86 to 1.69) and end-of-trial (OR 1.05, 95% CI 0.83 to 1.32) case fatality and symptomatic intracranial hemorrhage (OR 1.77, 95% CI 0. 95 to 3.31) were observed. End-of-trial death and disability was nonsignificantly reduced (OR 0.87, 95% CI 0.72 to 1.06). CONCLUSIONS: ++LMWHs reduce venous thromboembolic events in patients with acute ischemic stroke and increase the risk of extracranial bleeding. A nonsignificant reduction in combined death and disability and nonsignificant increases in case fatality and symptomatic intracranial hemorrhage were also observed. On the basis of the current evidence, LMWH should not be used in the routine management of patients with ischemic stroke. 相似文献