全文获取类型
收费全文 | 213406篇 |
免费 | 15613篇 |
国内免费 | 755篇 |
专业分类
耳鼻咽喉 | 2293篇 |
儿科学 | 5538篇 |
妇产科学 | 4422篇 |
基础医学 | 27690篇 |
口腔科学 | 4592篇 |
临床医学 | 20284篇 |
内科学 | 45468篇 |
皮肤病学 | 2889篇 |
神经病学 | 20615篇 |
特种医学 | 7071篇 |
外国民族医学 | 13篇 |
外科学 | 33343篇 |
综合类 | 3462篇 |
现状与发展 | 2篇 |
一般理论 | 315篇 |
预防医学 | 19362篇 |
眼科学 | 4390篇 |
药学 | 14604篇 |
1篇 | |
中国医学 | 375篇 |
肿瘤学 | 13045篇 |
出版年
2023年 | 867篇 |
2022年 | 1422篇 |
2021年 | 3481篇 |
2020年 | 2133篇 |
2019年 | 3434篇 |
2018年 | 4027篇 |
2017年 | 3253篇 |
2016年 | 3446篇 |
2015年 | 4111篇 |
2014年 | 6155篇 |
2013年 | 8924篇 |
2012年 | 13219篇 |
2011年 | 14446篇 |
2010年 | 8172篇 |
2009年 | 7363篇 |
2008年 | 13709篇 |
2007年 | 14546篇 |
2006年 | 14048篇 |
2005年 | 14518篇 |
2004年 | 13916篇 |
2003年 | 13003篇 |
2002年 | 12531篇 |
2001年 | 1986篇 |
2000年 | 1600篇 |
1999年 | 2138篇 |
1998年 | 2873篇 |
1997年 | 2475篇 |
1996年 | 2250篇 |
1995年 | 1977篇 |
1994年 | 1788篇 |
1993年 | 1689篇 |
1992年 | 1306篇 |
1991年 | 1248篇 |
1990年 | 1137篇 |
1989年 | 1043篇 |
1988年 | 1085篇 |
1987年 | 1088篇 |
1986年 | 1073篇 |
1985年 | 1154篇 |
1984年 | 1531篇 |
1983年 | 1512篇 |
1982年 | 1852篇 |
1981年 | 1668篇 |
1980年 | 1575篇 |
1979年 | 856篇 |
1978年 | 996篇 |
1977年 | 966篇 |
1976年 | 861篇 |
1975年 | 703篇 |
1974年 | 704篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Economic efficiency versus social equality? The U.S. liberal model versus the European social model.
This article begins by challenging the widely held view in neoliberal discourse that there is a necessary trade-off between higher efficiency and lower reduction of inequalities: the article empirically shows that the liberal, U.S. model has been less efficient economically (slower economic growth, higher unemployment) than the social model in existence in the European Union and in the majority of its member states. Based on the data presented, the authors criticize the adoption of features of the liberal model (such as deregulation of their labor markets, reduction of public social expenditures) by some European governments. The second section analyzes the causes for the slowdown of economic growth and the increase of unemployment in the European Union--that is, the application of monetarist and neoliberal policies in the institutional frame of the European Union, including the Stability Pact, the objectives and modus operandi of the European Central Bank, and the very limited resources available to the European Commission for stimulating and distributive functions. The third section details the reasons for these developments, including (besides historical considerations) the enormous influence of financial capital in the E.U. institutions and the very limited democracy. Proposals for change are included. 相似文献
42.
Zia Hossein Ma Joseph K. H. O'Donnell John P. Luzzi Louis A. 《Pharmaceutical research》1991,8(4):502-504
Dimethyl isosorbide (DMI), which is currently under investigation for its potential use as a pharmaceutical vehicle and drug permeation enhancer, is a water-miscible liquid with relatively low viscosity. The solubilization behavior of DMI as a cosolvent for nonpolar drugs was characterized via dielectric constant measurements of binary solvent systems containing DMI and either water, propylene glycol (PG), or polyethylene glycol (PEG). Evidence from the dielectric constant profiles and NMR studies suggest that DMI undergoes complexation with water and PG, but not with PEG, through hydrogen bonding interactions. The solvent complexation exhibited a major effect on the solubilities of prednisone, dexamethasone, and prednisolone in the mixed solvent systems. Maximum solubility of each drug was found to occur near a DMI/water or DMI/PG concentration ratio of 1:2. In the DMI–PEG mixed system, while there is no apparent interaction between DMI and PEG molecules, the solubility of prednisone was found to increase with decreasing dielectric constant. 相似文献
43.
John Hawk 《Photodermatology, photoimmunology & photomedicine》2002,18(3):146-146
44.
Dipankar Nandi Helen Smith Sarah Owen Carole Joint John Stein Tipu Aziz 《Journal of clinical neuroscience》2002,9(5):557-561
Central post stroke pain is often difficult to manage satisfactorily with conventional treatment modalities for pain. In the last decade functional neurosurgery has offered hope with motor cortex stimulation achieving significant alleviation of pain in some patients. Unfortunately this has led to the neglect of chronic stimulation of deep grey matter as another modality of treating this condition. In this article we present our experience with motor cortex stimulation and that with deep grey matter stimulation in patients with post stroke pain. We argue that both modalities have a significant role and that what is required are better methods of identifying particular patients who are more likely to respond to one or the other. 相似文献
45.
46.
47.
Addition of bevacizumab to bolus fluorouracil and leucovorin in first-line metastatic colorectal cancer: results of a randomized phase II trial. 总被引:11,自引:0,他引:11
Fairooz F Kabbinavar Joseph Schulz Michael McCleod Taral Patel John T Hamm J Randolph Hecht Robert Mass Brent Perrou Betty Nelson William F Novotny 《Journal of clinical oncology》2005,23(16):3697-3705
PURPOSE: Bevacizumab, a monoclonal antibody against vascular endothelial growth factor, increases survival when combined with irinotecan-based chemotherapy in first-line treatment of metastatic colorectal cancer (CRC). This randomized, phase II trial compared bevacizumab plus fluorouracil and leucovorin (FU/LV) versus placebo plus FU/LV as first-line therapy in patients considered nonoptimal candidates for first-line irinotecan. PATIENTS AND METHODS: Patients had metastatic CRC and one of the following characteristics: age > or = 65 years, Eastern Cooperative Oncology Group performance status 1 or 2, serum albumin < or = 3.5 g/dL, or prior abdominal/pelvic radiotherapy. Patients were randomly assigned to FU/LV/placebo (n = 105) or FU/LV/bevacizumab (n = 104). The primary end point was overall survival. Secondary end points were progression-free survival, response rate, response duration, and quality of life. Safety was also assessed. RESULTS: Median survival was 16.6 months for the FU/LV/bevacizumab group and 12.9 months for the FU/LV/placebo group (hazard ratio, 0.79; P = .16). Median progression-free survival was 9.2 months (FU/LV/bevacizumab) and 5.5 months (FU/LV/placebo); hazard ratio was 0.50; P = .0002. Response rates were 26.0% (FU/LV/bevacizumab) and 15.2% (FU/LV/placebo) (P = .055); duration of response was 9.2 months (FU/LV/bevacizumab) and 6.8 months (FU/LV/placebo); hazard ratio was 0.42; P = .088. Grade 3 hypertension was more common with bevacizumab treatment (16% v 3%) but was controlled with oral medication and did not cause study drug discontinuation. CONCLUSION: Addition of bevacizumab to FU/LV as first-line therapy in CRC patients who were not considered optimal candidates for first-line irinotecan treatment provided clinically significant patient benefit, including statistically significant improvement in progression-free survival. 相似文献
48.
Background
Cerebral arterial gas embolism is a potentially life-threatening event. Intraarterial air can occlude blood flow directly or cause thrombosis. Sclerotherapy is an extremely rare cause of cerebral arterial gas embolism. 相似文献49.
Anthony P. Belanger John F. Byrne Justin M. Paolino Timothy R. DeGrado 《Nuclear medicine and biology》2009,36(8):955-959
The bubble point test is the de facto standard for postproduction filter membrane integrity test in the radiopharmaceutical community. However, the bubble point test depends on a subjective visual assessment of bubbling rate that can be obscured by significant diffusive gas flows below the manufacturer's prescribed bubble point. To provide a more objective means to assess filter membrane integrity, this study evaluates the pressure-hold test as an alternative to the bubble point test. In our application of the pressure-hold test, the nonsterile side of the sterilizing filter is pressurized to 85% of the predetermined bubble point with nitrogen, the filter system is closed off from the pressurizing gas and the pressure is monitored over a prescribed time interval. The drop in pressure, which has a known relationship with diffusive gas flow, is used as a quantitative measure of membrane integrity. Characterization of the gas flow vs. pressure relationship of each filter/solution combination provides an objective and quantitative means for defining a critical value of pressure drop over which the membrane is indicated to be nonintegral. The method is applied to sterilizing filter integrity testing associated with the commonly produced radiopharmaceuticals, [18F]FDG and [11C]PIB. The method is shown to be robust, practical and amenable to automation in radiopharmaceutical manufacturing environments (e.g., hot cells). 相似文献
50.