首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   33642篇
  免费   2226篇
  国内免费   206篇
耳鼻咽喉   319篇
儿科学   569篇
妇产科学   449篇
基础医学   4719篇
口腔科学   896篇
临床医学   3460篇
内科学   7176篇
皮肤病学   666篇
神经病学   3775篇
特种医学   1963篇
外科学   5320篇
综合类   185篇
一般理论   7篇
预防医学   1463篇
眼科学   688篇
药学   2015篇
中国医学   69篇
肿瘤学   2335篇
  2024年   21篇
  2023年   238篇
  2022年   504篇
  2021年   894篇
  2020年   640篇
  2019年   830篇
  2018年   947篇
  2017年   811篇
  2016年   941篇
  2015年   1141篇
  2014年   1376篇
  2013年   1674篇
  2012年   2724篇
  2011年   2837篇
  2010年   1691篇
  2009年   1512篇
  2008年   2399篇
  2007年   2408篇
  2006年   2253篇
  2005年   2199篇
  2004年   1975篇
  2003年   1801篇
  2002年   1665篇
  2001年   285篇
  2000年   202篇
  1999年   263篇
  1998年   312篇
  1997年   233篇
  1996年   185篇
  1995年   161篇
  1994年   132篇
  1993年   124篇
  1992年   73篇
  1991年   58篇
  1990年   56篇
  1989年   39篇
  1988年   39篇
  1987年   31篇
  1986年   33篇
  1985年   31篇
  1984年   40篇
  1983年   29篇
  1982年   32篇
  1981年   29篇
  1980年   18篇
  1978年   12篇
  1977年   12篇
  1974年   9篇
  1931年   7篇
  1927年   8篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
41.
The aim of this study was to evaluate a case-mix system to classify inpatients with mental disorders in Germany by means of self-report and expert-rated instruments. The use of case-mix systems enhances the transparency of performance and cost structure and can thus improve the quality of mental health care. We analysed a consecutive sample of 1677 inpatients with mental disorders from 11 hospitals using regression tree analysis. The model assigns patients to 17 groups, accounting for 17% of the variance for duration of stay. Patients with eating disorders had a longer duration of stay than patients with anxiety disorder, duration of mental illness of less than 3–5 years, lower levels of interpersonal problems and higher occupational position. The results showed that besides diagnosis, variables such as duration of illness and interpersonal problems are important for classifying inpatients with mental disorders. The results of the study should be critically reviewed regarding the empirical results of other studies and the appropriateness of case group concepts for inpatients with mental disorders.  相似文献   
42.
43.
It obviously escaped the notion of Egeland and Brinchman thatthe protocols additionally differ with regard to the washingsteps and buffer components used in the  相似文献   
44.
PURPOSE: To study the effect of treatment time prolongation following initial dose acceleration on the response of subcutaneously growing R1H tumor. MATERIAL AND METHODS: Continuous standard fractionation (30 fractions/40 days) was compared to initially accelerated treatment (30 fractions/21 days) followed by five to two fractions per week yielding total treatment times from 40 to 72 days. Local tumor control was assessed as endpoint. RESULTS: Radiation dose to control 50% of the tumors (TCD50%) decreased statistically significant from 83.5 Gy (95% confidence interval [CI]: 78.6 .. 88.4) for standard fractionation to 74.1 Gy (95% CI: 72.7 .. 75.5) determined for all accelerated treatment arms (p = 0.003). Prolongation of treatment time after initial acceleration from 40 to 72 days led to a small but statistically not significant increase in TCD50% from 72.0 Gy (95% CI: 71.0 .. 72.9) to 76.2 Gy (95% CI: 69.9 .. 82.4) corresponding to a repopulated dose of 0.9 Gy per week. This time factor is considerably smaller than for conventional radiation treatment as determined in previous experiments. CONCLUSION: The results indicate that initially accelerated irradiation not only improves local tumor control but also minimizes the negative effect of treatment time prolongation. This might be due to changes in tumor cell repopulation kinetics.  相似文献   
45.
46.
Background: Although the activation-induced intracellular Ca2+ signal is disrupted by sensory neuron injury, the contribution of specific Ca2+ channel subtypes is unknown.

Methods: Transients in dissociated rat dorsal root ganglion neurons were recorded using fura-2 microfluorometry. Neurons from control rats and from neuropathic animals after spinal nerve ligation were activated either by elevated bath K+ or by field stimulation. Transients were compared before and after application of selective blockers of voltage-activated Ca2+ channel subtypes.

Results: Transient amplitude and area were decreased by blockade of the L-type channel, particularly during sustained K+ stimulation. Significant contributions to the Ca2+ transient are attributable to the N-, P/Q-, and R-type channels, especially in small neurons. Results for T-type blockade varied widely between cells. After injury, transients lost sensitivity to N-type and R-type blockers in axotomized small neurons, whereas adjacent small neurons showed decreased responses to blockers of R-type channels. Axotomized large neurons were less sensitive to blockade of N- and P/Q-type channels. After injury, neurons adjacent to axotomy show decreased sensitivity of K+-induced transients to L-type blockade but increased sensitivity during field stimulation.  相似文献   

47.
48.
Introduction Choroid plexus cysts can lead to isolation of the lateral ventricles and distension of the third ventricle. We present an ultrasonographic video documentation of an infant with variably shaped and localized choroid plexus cyst of the third ventricle. Case report An infant had periods of increased intracranial pressure with changing dilatation of the first to third ventricle. Cerebral ultrasonography of the not crying boy demonstrated a choroid plexus cyst limply hanging down from the roof of the third ventricle to the beginning of the aqueduct of Sylvius. During crying, the cyst prolapsed from the third into left lateral ventricle and was strangled by the foramen of Monro. Endoscopic cyst fenestration and third ventriculostomy continuously solved the problem of intermittent hydrocephalus occlusus. Conclusion Depending not only on localization and size but also on cyst form and cerebrospinal fluid pressure, a single choroid plexus cyst can cause various obstructions of cerebrospinal fluid pathways.  相似文献   
49.
50.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号