全文获取类型
收费全文 | 4197篇 |
免费 | 302篇 |
国内免费 | 87篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 227篇 |
妇产科学 | 175篇 |
基础医学 | 500篇 |
口腔科学 | 128篇 |
临床医学 | 401篇 |
内科学 | 839篇 |
皮肤病学 | 78篇 |
神经病学 | 204篇 |
特种医学 | 316篇 |
外科学 | 587篇 |
综合类 | 89篇 |
预防医学 | 247篇 |
眼科学 | 136篇 |
药学 | 296篇 |
中国医学 | 31篇 |
肿瘤学 | 312篇 |
出版年
2023年 | 34篇 |
2022年 | 34篇 |
2021年 | 128篇 |
2020年 | 70篇 |
2019年 | 90篇 |
2018年 | 109篇 |
2017年 | 83篇 |
2016年 | 84篇 |
2015年 | 97篇 |
2014年 | 146篇 |
2013年 | 156篇 |
2012年 | 252篇 |
2011年 | 280篇 |
2010年 | 168篇 |
2009年 | 177篇 |
2008年 | 198篇 |
2007年 | 243篇 |
2006年 | 200篇 |
2005年 | 201篇 |
2004年 | 162篇 |
2003年 | 132篇 |
2002年 | 145篇 |
2001年 | 156篇 |
2000年 | 133篇 |
1999年 | 114篇 |
1998年 | 73篇 |
1997年 | 63篇 |
1996年 | 56篇 |
1995年 | 52篇 |
1994年 | 50篇 |
1993年 | 39篇 |
1992年 | 59篇 |
1991年 | 54篇 |
1990年 | 42篇 |
1989年 | 54篇 |
1988年 | 64篇 |
1987年 | 66篇 |
1986年 | 56篇 |
1985年 | 39篇 |
1984年 | 27篇 |
1983年 | 21篇 |
1982年 | 23篇 |
1981年 | 23篇 |
1980年 | 14篇 |
1979年 | 16篇 |
1978年 | 18篇 |
1977年 | 17篇 |
1976年 | 19篇 |
1975年 | 10篇 |
1973年 | 9篇 |
排序方式: 共有4586条查询结果,搜索用时 15 毫秒
91.
92.
93.
Tseng SK Chang MC Su CY Chi LY Chang JZ Tseng WY Yeung SY Hsu ML Jeng JH 《Clinical oral investigations》2012,16(4):1267-1273
Betel quid (BQ) chewing is a common oral habit in South Asia and Taiwan. BQ consumption may increase the risk of oral squamous cell carcinoma (OSCC), oral submucous fibrosis (OSF), and periodontitis as well as systemic diseases (atherosclerosis, hypertension, etc.). However, little is known about the toxic effect of BQ components on endothelial cells that play important roles for angiogenesis, carcinogenesis, tissue fibrosis, and cardiovascular diseases. EAhy 926 (EAHY) endothelial cells were exposed to arecoline, a major BQ alkaloid, for various time periods. Cytotoxicity was estimated by 3-(4, 5- dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay. The cell cycle distribution of EAHY cells residing in sub-G0/G1, G0/G1, S-, and G2/M phases was analyzed by propidium iodide staining of cellular DNA content and flow cytometry. Some EAHY cells retracted, became round-shaped in appearance, and even detached from the culture plate after exposure to higher concentrations of arecoline (> 0.4 mM). At concentrations of 0.4 and 0.8 mM, arecoline induced significant cytotoxicity to EAHY cells. At similar concentrations, arecoline induced G2/M cell cycle arrest and increased sub-G0/G1 population, a hallmark of apoptosis. Interestingly, prolonged exposure to arecoline (0.1 mM) for 12 and 21 days significantly suppressed the proliferation of EAHY cells, whereas EAHY cells showed adaptation and survived when exposed to 0.05 mM arecoline. These results suggest that BQ components may contribute to the pathogenesis of OSF and BQ chewing-related cardiovascular diseases via toxicity to oral or systemic endothelial cells, leading to impairment of vascular function. During BQ chewing, endothelial damage may be induced by areca nut components and associate with the pathogenesis of OSF, periodontitis, and cardiovascular diseases. 相似文献
94.
95.
96.
97.
Nosocomial outbreaks of influenza are reportable in New York State, but reporting compliance is unknown. We describe a surveillance system, instituted during the 2009 H1N1 outbreak, that coincidently allowed for the identification of influenza outbreaks in long-term care facilities. 相似文献
98.
99.
ObjectiveTo establish the presence or absence of an age effect on the ipsilateral silent period (iSP) for the abductor pollicis brevis (APB) muscle in healthy subjects.MethodsTwenty young adults (10 men, 10 women; age range: 20–40) and 20 older adults (10 men, 10 women; age range: 50–70) were matched by age (+30 years), gender and height (±5 cm). All were right-handed. We investigated the iSP for the APB by applying transcranial magnetic stimulation (TMS) and recording surface electromyograms. The contralateral motor-evoked potential (MEP) onset latency, the iSP onset and end latency (iSPOL and iSPEL) were measured and the iSP duration (iSPD) and transcallosal conduction time (TCT) were calculated. We evaluated the correlation between age and iSP, the latter’s intra- and intersession reproducibility and potential influencing factors.ResultsMean iSPOL, iSPEL and TCT values were significantly greater in older adults (both men and women) than in young adults. Intra- and intersession reproducibility was good. The mean left-side iSPEL and iSPD were longer than the right-side mean values in young adults but not in older adults. In both age groups, women displayed shorter latencies than men.ConclusionsThere is a strong effect of age on iSP parameters.SignificanceOur iSP results may evidence a decrease in transcallosal excitability with age, rather than slowing of the transcallosal interneuron conduction velocity. 相似文献
100.