全文获取类型
收费全文 | 96584篇 |
免费 | 5037篇 |
国内免费 | 276篇 |
专业分类
耳鼻咽喉 | 1138篇 |
儿科学 | 2119篇 |
妇产科学 | 2057篇 |
基础医学 | 12968篇 |
口腔科学 | 3499篇 |
临床医学 | 7519篇 |
内科学 | 23840篇 |
皮肤病学 | 2211篇 |
神经病学 | 8545篇 |
特种医学 | 2328篇 |
外科学 | 12962篇 |
综合类 | 455篇 |
现状与发展 | 1篇 |
一般理论 | 36篇 |
预防医学 | 8307篇 |
眼科学 | 1787篇 |
药学 | 6315篇 |
中国医学 | 330篇 |
肿瘤学 | 5480篇 |
出版年
2024年 | 64篇 |
2023年 | 610篇 |
2022年 | 637篇 |
2021年 | 1901篇 |
2020年 | 1041篇 |
2019年 | 1879篇 |
2018年 | 3006篇 |
2017年 | 1910篇 |
2016年 | 2005篇 |
2015年 | 2635篇 |
2014年 | 2920篇 |
2013年 | 4123篇 |
2012年 | 8311篇 |
2011年 | 8428篇 |
2010年 | 4003篇 |
2009年 | 3079篇 |
2008年 | 7097篇 |
2007年 | 7293篇 |
2006年 | 7177篇 |
2005年 | 6956篇 |
2004年 | 6224篇 |
2003年 | 5704篇 |
2002年 | 5389篇 |
2001年 | 1717篇 |
2000年 | 2163篇 |
1999年 | 1168篇 |
1998年 | 400篇 |
1997年 | 331篇 |
1996年 | 303篇 |
1995年 | 293篇 |
1994年 | 230篇 |
1993年 | 219篇 |
1992年 | 210篇 |
1991年 | 188篇 |
1990年 | 119篇 |
1989年 | 131篇 |
1988年 | 97篇 |
1987年 | 94篇 |
1986年 | 111篇 |
1985年 | 126篇 |
1984年 | 151篇 |
1983年 | 95篇 |
1982年 | 126篇 |
1981年 | 120篇 |
1980年 | 113篇 |
1979年 | 79篇 |
1978年 | 78篇 |
1977年 | 61篇 |
1976年 | 69篇 |
1974年 | 65篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Thomas J van Brakel Gil Bolotin L Wiley Nifong André L A J Dekker Maurits A Allessie W Randolph Chitwood Jos G Maessen 《European heart journal》2005,26(13):1321-1326
AIMS: To study the feasibility and electrophysiological efficacy of minimally invasive beating heart ablation of the pulmonary veins (PVs) via a robot-assisted single-sided approach. BACKGROUND: PV isolation by minimally invasive epicardial ablation may offer a new treatment for patients with lone atrial fibrillation (AF). However, complete PV isolation has been shown to be difficult to obtain. METHODS AND RESULTS: In 14 mongrel dogs, robot-assisted epicardial microwave ablation was performed on the beating heart by a single-sided right chest approach. Isolation of all PVs was performed in two steps to study the effect of an incomplete and a complete isolation on AF. AF was studied by random and burst pacing. Incremental pacing was performed to study conduction characteristics across the lesions. Opening of the pericardial reflections, introduction of the catheter and ablation were robotically feasible by a single-sided approach in 11 dogs. The AF duration decreased from 6.6+/-4.1 to 1.3+/-0.8 s (P=0.03) and 1.6+/-1.6 s (P=0.04 compared with control) after incomplete and completed isolation of the PVs. The AF cycle length increased from 134+/-5 to 141+/-5 and 145+/-8 ms (P=0.03) after incomplete and complete isolation, respectively. Several incomplete lesions showed 2:1 exit and/or entrance block during incremental pacing. After complete isolation, AF was no longer inducible from the PVs. CONCLUSION: Epicardial PV isolation can be successfully performed by a single-sided robot-assisted approach. The effect of PV ablation on AF is not an all or none phenomenon. Incomplete isolation already decreases AF duration and lengthens the AF cycle length. However, complete isolation is necessary to prevent AF induction by triggering from the isolated area. 相似文献
993.
994.
Lewden C Raffi F Cuzin L Cailleton V Vildé JL Chêne G Allavena C Salamon R Leport C 《The Journal of infectious diseases》2002,186(5):710-714
This study attempted to identify factors associated with mortality among human immunodeficiency virus (HIV)-infected adults starting a protease inhibitor (PI)-containing therapy. Among 1155 patients consecutively enrolled in the APROCO study between May 1997 and June 1998, clinical characteristics were as follows: median age, 36 years; median baseline CD4 cell count, 288 cells/mm(3); and median baseline plasma HIV RNA load, 4.4 log(10) copies/mL. After a median follow-up of 27 months, 48 deaths had occurred, of which 44% were related to acquired immune deficiency syndrome. The mortality rate was 2.9% at 12 months. When both data at baseline and data at 4 months after the start of PI therapy were considered, factors independently associated with mortality were (Cox model) low baseline plasma creatinine level, low school education level, low CD4 cell count at 4 months, low hemoglobin level, and elevated hepatic transaminase levels. Thus, social context plus clinical and biologic data, including the 4-month response to treatment, must be considered in treatment of HIV-infected patients. 相似文献
995.
Laurent C Bourgeois A Faye MA Mougnutou R Seydi M Gueye M Liégeois F Kane CT Butel C Mbuagbaw J Zekeng L Mboup S Mpoudi-Ngolé E Peeters M Delaporte E 《The Journal of infectious diseases》2002,186(4):486-492
To compare human immunodeficiency virus (HIV) type 1 disease progression in patients infected by the predominant strain circulating recombinant form (CRF) 02_AG in western and west-central Africa and in patients infected by other strains, a prospective multicenter cohort study was conducted in Cameroon and Senegal. Among the 335 patients, a broad HIV-1 group M subtype diversity was observed in the envelope V3-V5 region, but strain CRF02_AG predominated in both Cameroon and Senegal (61.2% and 62.9%, respectively; P<.8). Multivariate analyses showed no difference between patients infected by CRF02 strains and those infected by other strains in terms of survival (adjusted hazards ratio [HR], 1.16; 95% confidence interval [CI], 0.76-1.78; P=.5), clinical disease progression (HR, 0.79; 95% CI, 0.50-1.25; P=.3), or square root CD4 cell decline (regression coefficient, -0.01; 95% CI, -0.82 to 0.81; P=.9). This study suggests that the predominance of HIV-1 CRF02_AG strain in western and west-central Africa should have no major clinical consequences. 相似文献
996.
997.
Focal nodular hyperplasia occurring after blunt abdominal trauma 总被引:2,自引:0,他引:2
Savoye-Collet C Hervé S Koning E Scotté M Dacher JN 《European journal of gastroenterology & hepatology》2002,14(3):329-330
Focal nodular hyperplasia of the liver is a benign neoplasm. The pathogenesis is unknown, but it was hypothesized that focal nodular hyperplasia may be a response to a vascular abnormality. We report on a case of focal nodular hyperplasia that developed in a young patient 1 year after a blunt hepatic injury. 相似文献
998.
999.
Girard F Chaboillez S Cartier A Côté J Hargreave FE Labrecque M Malo JL Tarlo SM Lemière C 《American journal of respiratory and critical care medicine》2004,170(8):845-850
Monitoring airway inflammation by means of induced sputum cell counts seems to improve the management of asthma. We sought to assess whether such monitoring at the end of periods at and away from work combined with the monitoring of PEF could improve the diagnosis of occupational asthma. We enrolled subjects suspected of having occupational asthma. Serial monitoring of PEF was performed during 2 weeks at and away from work. At the end of each period, induced sputum was collected. Specific inhalation challenge was subsequently performed. PEF graphs were interpreted visually by five independent observers. Forty-nine subjects, including 23 with positive specific inhalation challenge, completed the study. The addition of sputum cell counts to the monitoring of PEF increased the specificity of this test, respectively, by 18 (range [r] 13.7-25.5) or 26.8% (r 24.8-30.4) depending if an increase of sputum eosinophils greater than 1 or 2% when at work was considered as significant. The sensitivity increased by 8.2% (r 4.1-13.4) or decreased by 12.3% (r 3.1-24.1) depending on the cutoff value in sputum eosinophils chosen (greater than 1 or 2%, respectively). The addition of sputum cell counts to PEF monitoring is useful to improve the diagnosis of occupational asthma. 相似文献
1000.
Martínez E Milinkovic A de Lazzari E Ravasi G Blanco JL Larrousse M Mallolas J García F Miró JM Gatell JM 《Lancet》2004,364(9428):65-67
The rise in didanosine concentrations in plasma when given with tenofovir raises concern for a high risk of toxic effects. Recommendations to reduce didanosine dose have been issued, but only for adults weighing more than 60 kg. We reviewed cases of pancreatitis in patients receiving didanosine plus tenofovir, didanosine alone, and tenofovir alone to assess the incidence of and risk factors for pancreatitis. Between Aug 1, 2001, and Nov 30, 2003, five of 185 (2.7%) patients receiving didanosine plus tenofovir, one of 182 (0.5%) on didanosine without tenofovir, and none of 208 on tenofovir without didanosine developed pancreatitis (p=0.016). Co-administration of both drugs versus each of them individually was an independent risk factor for pancreatitis (crude hazard ratio 10.666, 95% CI 1.246-91.294, p=0.031). These results suggest that the risk of pancreatitis is heightened when didanosine and tenofovir are given together. 相似文献