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   4005篇
  免费   231篇
  国内免费   11篇
耳鼻咽喉   33篇
儿科学   255篇
妇产科学   43篇
基础医学   509篇
口腔科学   94篇
临床医学   289篇
内科学   815篇
皮肤病学   37篇
神经病学   257篇
特种医学   185篇
外科学   448篇
综合类   76篇
一般理论   1篇
预防医学   257篇
眼科学   394篇
药学   281篇
  1篇
中国医学   15篇
肿瘤学   257篇
  2023年   33篇
  2022年   63篇
  2021年   122篇
  2020年   74篇
  2019年   84篇
  2018年   99篇
  2017年   69篇
  2016年   82篇
  2015年   97篇
  2014年   158篇
  2013年   167篇
  2012年   296篇
  2011年   275篇
  2010年   164篇
  2009年   139篇
  2008年   231篇
  2007年   252篇
  2006年   226篇
  2005年   213篇
  2004年   203篇
  2003年   135篇
  2002年   123篇
  2001年   102篇
  2000年   87篇
  1999年   76篇
  1998年   28篇
  1997年   23篇
  1996年   17篇
  1995年   22篇
  1994年   14篇
  1993年   15篇
  1992年   34篇
  1991年   38篇
  1990年   42篇
  1989年   45篇
  1988年   28篇
  1987年   33篇
  1986年   32篇
  1985年   27篇
  1984年   21篇
  1983年   19篇
  1982年   14篇
  1981年   22篇
  1980年   13篇
  1979年   32篇
  1977年   16篇
  1975年   17篇
  1973年   13篇
  1972年   13篇
  1970年   13篇
排序方式: 共有4247条查询结果,搜索用时 15 毫秒
11.
The possibility of pineal gland involvement as a part of "neuroendocrine dysfunction" in some of the psychiatric diseases has received special attention in recent years. The discovery of a cascade of receptors and the action of many psychoactive drugs on pineal gland supports the concept that the pineal gland can be considered as a suitable model system for assessing the action of psychotropic drugs. Psychotropic drugs, particularly antidepressants both tricyclics and monoamine oxidase inhibitors when administered either to animals or to patients suffering from depressive illness affects the pineal gland function and melatonin concentration. This raises the possibility that the beneficial effects of these drugs may relate to their ability to alter the pineal gland function and melatonin secretion. The occurrence of seasonal affective disorders and their response to bright light treatment implicate, melatonin as a "bio-chemical marker" for these disease states. In view of these facts it can be suggested that pineal gland does play an important role in the etiology of mental diseases, especially affective disorders.  相似文献   
12.
13.

Background  

Lymph node infarction is known to occur in association with many non-neoplastic and neoplastic conditions however its occurrence in association with DIC is not reported hitherto in the literature.  相似文献   
14.
15.
16.
17.
Responses of rapidly adapting Meissner corpuscle mechanoreceptive afferent fibers (RAs) to steps of varying shape stroked across the distal fingerpad were recorded from anesthetized monkeys. A series of flat plates were used, each having an increase in thickness (a step) in the middle so that one-half of the plate was thicker than the other. The cross-sectional shape of the step approximated that of a half-cycle sinusoid, 0.5 mm high. The width (half-cycle wavelength) of the sinusoidal step was varied from 0 to 3.13 mm, producing a series of step shapes that differed in steepness and curvature. These steps could be broadly categorized into 2 groups, "steep" and "gradual." Each step was stroked back and forth under constant compressional force, using a servocontrolled mechanical stimulator. The RA's response to a step provided a spatial pattern of action potentials in which the occurrence of each impulse corresponded to a position of the step on the skin. This response consisted of a single "burst" of impulses to the sinusoidal portion of the step. Changes in stroke direction, step shape, or velocity of stroking primarily affected the RA discharge rate during the burst, and, less consistently, the spatial width of the burst. For a given step shape and stroke velocity, the discharge rate was greater for strokes from the low to the high side of the step than for strokes from the high to the low side. Discharge rate was greater for steep than for gradual steps and, for a given step, it increased with stroke velocity. All the major features of the responses were interpreted as being due predominantly to the sensitivity of the RA to vertical velocity at the most sensitive spot on its receptive field, together with a sensitivity to the rate of change in skin curvature at that spot. RA discharge rate distinguished not only the gross differences between steep and gradual steps, but also some of the finer differences in sharpness among steep steps. From a comparison with the human capacity for tactile discrimination of the steps, it was concluded that RAs, through their discharge rates, provide primarily "intensive" information about the sharpness of shapes.  相似文献   
18.
Maternal and Child Health Journal - Each year, 3% of infants in the Unites States (US) are born with congenital anomalies, including 3000 with neural tube defects. Multivitamins (MVIs) including...  相似文献   
19.
The prevalence of type 2 diabetes in youth has increased substantially, yet the genetic underpinnings remain largely unexplored. To identify genetic variants predisposing to youth-onset type 2 diabetes, we formed ProDiGY, a multiethnic collaboration of three studies (TODAY, SEARCH, and T2D-GENES) with 3,006 youth case subjects with type 2 diabetes (mean age 15.1 ± 2.9 years) and 6,061 diabetes-free adult control subjects (mean age 54.2 ± 12.4 years). After stratifying by principal component–clustered ethnicity, we performed association analyses on ∼10 million imputed variants using a generalized linear mixed model incorporating a genetic relationship matrix to account for population structure and adjusting for sex. We identified seven genome-wide significant loci, including the novel locus rs10992863 in PHF2 (P = 3.2 × 10−8; odds ratio [OR] = 1.23). Known loci identified in our analysis include rs7903146 in TCF7L2 (P = 8.0 × 10−20; OR 1.58), rs72982988 near MC4R (P = 4.4 × 10−14; OR 1.53), rs200893788 in CDC123 (P = 1.1 × 10−12; OR 1.32), rs2237892 in KCNQ1 (P = 4.8 × 10−11; OR 1.59), rs937589119 in IGF2BP2 (P = 3.1 × 10−9; OR 1.34), and rs113748381 in SLC16A11 (P = 4.1 × 10−8; OR 1.04). Secondary analysis with 856 diabetes-free youth control subjects uncovered an additional locus in CPEB2 (P = 3.2 × 10−8; OR 2.1) and consistent direction of effect for diabetes risk. In conclusion, we identified both known and novel loci in the first genome-wide association study of youth-onset type 2 diabetes.  相似文献   
20.
Lipomas are common benign tumours that can occur in most parts of the body. Lipomas arising from the deep temporal fat pad, found between the two layers of the deep temporal fascia, are rare, however; there has been only one documented case report to our knowledge. We describe a second case arising from the temporal fat pad in a patient treated at our unit, having previously reported the first one, and discuss the relevant anatomy and management.  相似文献   
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