全文获取类型
收费全文 | 34571篇 |
免费 | 2666篇 |
国内免费 | 404篇 |
专业分类
耳鼻咽喉 | 359篇 |
儿科学 | 1142篇 |
妇产科学 | 971篇 |
基础医学 | 4196篇 |
口腔科学 | 489篇 |
临床医学 | 6066篇 |
内科学 | 5789篇 |
皮肤病学 | 421篇 |
神经病学 | 3146篇 |
特种医学 | 713篇 |
外国民族医学 | 4篇 |
外科学 | 2883篇 |
综合类 | 1134篇 |
一般理论 | 64篇 |
预防医学 | 4335篇 |
眼科学 | 523篇 |
药学 | 2320篇 |
1篇 | |
中国医学 | 264篇 |
肿瘤学 | 2821篇 |
出版年
2023年 | 229篇 |
2022年 | 388篇 |
2021年 | 725篇 |
2020年 | 614篇 |
2019年 | 883篇 |
2018年 | 906篇 |
2017年 | 712篇 |
2016年 | 832篇 |
2015年 | 929篇 |
2014年 | 1221篇 |
2013年 | 1730篇 |
2012年 | 2354篇 |
2011年 | 2453篇 |
2010年 | 1389篇 |
2009年 | 1196篇 |
2008年 | 2173篇 |
2007年 | 2363篇 |
2006年 | 2345篇 |
2005年 | 2257篇 |
2004年 | 2054篇 |
2003年 | 1949篇 |
2002年 | 1856篇 |
2001年 | 367篇 |
2000年 | 356篇 |
1999年 | 429篇 |
1998年 | 509篇 |
1997年 | 396篇 |
1996年 | 369篇 |
1995年 | 352篇 |
1994年 | 311篇 |
1993年 | 297篇 |
1992年 | 217篇 |
1991年 | 175篇 |
1990年 | 165篇 |
1989年 | 175篇 |
1988年 | 140篇 |
1987年 | 113篇 |
1986年 | 130篇 |
1985年 | 142篇 |
1984年 | 125篇 |
1983年 | 126篇 |
1982年 | 149篇 |
1981年 | 143篇 |
1980年 | 149篇 |
1979年 | 66篇 |
1978年 | 64篇 |
1977年 | 65篇 |
1976年 | 64篇 |
1975年 | 54篇 |
1974年 | 50篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
53.
54.
Rachel Yehuda Ann Steiner Boaz Kahana Karen Binder-Brynes Steven M. Southwick Shelly Zemelman Earl L. Giller 《Journal of traumatic stress》1997,10(1):93-100
Alexithymia was measured in non-treatment seeking, community-dwelling Holocaust survivors using the Toronto Alexithymia Scale—Twenty Item Version (TAS-20). Scores of survivors with (n = 30) and without (n = 26) posttraumatic stress disorder (PTSD) were compared, and associations among alexithymia, severity of trauma, and severity of PTSD symptoms were determined. Survivors with PTSD had significantly higher scores on the TAS-20 compared to survivors without PTSD. TAS-20 scores were significantly associated with severity of PTSD symptoms, but not with severity of trauma. This study adds to our knowledge of the relationship between alexithymia and trauma by demonstrating that this characteristic is related to the presence of posttraumatic symptoms and not simply exposure to trauma. 相似文献
55.
56.
Ann Bowling Morag Farquhar Emily Grundy Juliet Formby 《International journal of geriatric psychiatry》1992,7(5):307-321
This article reports findings from a longitudinal survey of very elderly people living at home in London. The research aimed to identify social, psychological and physical characteristics associated with positive ageing and successful survival in the community in later life and its converse—negative ageing—as well as the associated policy implications. Associations with psychiatric morbidity, measured using the General Health Questionnaire, among sample members without cognitive impairment between the baseline interviews in 1987 and at follow-up, two and a half years later in 1990, are reported. Twenty-five per cent of survivors scored over the threshold of the GHQ in 1987 and 30% scored over the threshold in 1990. Half of those with a score over the threshold in 1990 also scored over the threshold in 1987. Hierarchical regression (using residualized change analysis) was used to estimate the effects of the independent variables on changes in psychiatric morbidity. The most significant predictor of psychiatric morbidity (GHQ score) in 1990 was baseline GHQ score, followed by health and functional status scores. Health and functional status were also the strongest predictors of baseline (1987) GHQ scores. The uniqueness of the study lies in the collection of follow-up data on a sample of very elderly people, given that most surveys are corss-sectional and contain too few people aged 85+ to merit separate analysis. It contributes to the small body of literature on outcome of depression. The lack of consistent associations with recovery from psychiatric morbidity in the literature enhances the importance of studies aiming to identify factors associated with different outcomes. 相似文献
57.
58.
T Nagatake V T Hoang T Tegoshi J Rabbege T K Ann M Aikawa 《The American journal of tropical medicine and hygiene》1992,47(2):259-264
Autopsy samples from the brains of 20 patients who died of falciparum malaria were examined by light microscopy and by an immunohistologic method. Particular attention was paid to a comparison of the pathologic features of the white matter and the cortex. In the high-sequestration (greater than 50%) group (n = 8), the mean +/- SD percentage of cerebral microvessels that showed parasitized red blood cell (PRBC) sequestration was 71.2 +/- 8.1% in the cortex and 84.0 +/- 6.7% in the white matter. The difference in the PRBC sequestration rate between cortex and white matter was statistically significant (P less than 0.01). Perivascular and ring hemorrhages were seen more frequently in the white matter than in the cortex. Deposition of IgG and Plasmodium falciparum antigen in the cerebral microvessels was more highly significant in the white matter than in the cortex (P less than 0.01). Our study demonstrated that the localized concentration of PRBC sequestration in the brain correlated with the marked immunohistologic differences in the microvessels of cortex and white matter. 相似文献
59.
Levodopa improves physical fatigue in Parkinson's disease: a double-blind, placebo-controlled, crossover study. 总被引:1,自引:0,他引:1
Jau-Shin Lou Greg Kearns Theodore Benice Barry Oken Gary Sexton John Nutt 《Movement disorders》2003,18(10):1108-1114
We quantitatively investigated the effect of carbidopa/levodopa (25/100) on physical fatigue during finger tapping and force generation in a double-blind, placebo-controlled crossover study. Parkinson's disease (PD) subjects were randomly assigned to carbidopa/levodopa or placebo for Visit 1 or 2 and participated in the following two studies: (1) Finger tapping. Twenty-five PD patients used their index fingers to strike two keys 20 cm apart on a musical instrument digital interface (MIDI) keyboard. The slopes of the regression line of dwell time and movement time were used to assess the rate of fatigue development. (2) Force generation. Twelve PD patients contracted the wrist extensors maximally to obtain a baseline maximum voluntary contraction (BMVC) force. Then they repetitively contracted the wrist extensors at 50% of the BMVC for 7 seconds and rested for 3 seconds. An interval maximum voluntary contraction (IMVC) was measured every three repetitions. Fatigue was defined as an IMVC of less than 60% of the BMVC. The slope of the regression line of IMVC was used to assess the rate of force decline. These two studies were repeated 1 hour after carbidopa/levodopa (25/100) or placebo. Subjects filled out the Multidimensional Fatigue Inventory (MFI) at the beginning of the first visit. Results showed that the slope of dwell time decreased with levodopa but not with placebo (P = 0.004). The rate of force decline also decreased with levodopa but not with placebo (P = 0.01). The subscores in the dimension of physical fatigue in the MFI did not correlate with the rate changes in dwell time or the rate changes in force decline. We concluded that (1) levodopa improves physical fatigue in finger tapping and force generation, (2) physical fatigue in Parkinson's disease is at least partially related to dopamine deficiency, and (3) the MFI measures different aspects of physical fatigue compared with those measured by finger tapping and force generation. 相似文献
60.
Background. A single deep inspiration (DI) is known to be a potent bronchodilator but it is not known if repeated DI can accelerate sustained recovery from bronchoconstriction. Methods. We induced sustained bronchoconstriction using increasing concentrations of nebulized methacholine (Mch) during tidal breathing and assessed airway narrowing by measuring respiratory resistance (Rrs) using forced oscillation in six healthy subjects. On separate days we examined the effects of DI every 3 minutes and of prohibition of DI on recovery of Rrs for 30 minutes after the end of Mch nebulization. Results. Bronchoconstriction (Rrs ∼ 150% above baseline) was induced. DI during recovery had a transient bronchodilator effect but no cumulative effect. At 30 minutes after end of nebulization (and 2 minutes after the last DI) Rrs was 87% above baseline compared to 93% above baseline when DI was prohibited. Conclusion. Recovery from induced bronchoconstriction with methacholine was slow (∼ 2%/min) and not accelerated by frequent DI. 相似文献