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   18061篇
  免费   950篇
  国内免费   74篇
耳鼻咽喉   266篇
儿科学   419篇
妇产科学   535篇
基础医学   2527篇
口腔科学   1334篇
临床医学   1326篇
内科学   3640篇
皮肤病学   311篇
神经病学   1539篇
特种医学   526篇
外科学   2192篇
综合类   83篇
一般理论   8篇
预防医学   1576篇
眼科学   345篇
药学   1341篇
中国医学   83篇
肿瘤学   1034篇
  2023年   121篇
  2022年   245篇
  2021年   443篇
  2020年   271篇
  2019年   360篇
  2018年   489篇
  2017年   313篇
  2016年   348篇
  2015年   498篇
  2014年   642篇
  2013年   796篇
  2012年   1239篇
  2011年   1414篇
  2010年   691篇
  2009年   603篇
  2008年   1110篇
  2007年   1111篇
  2006年   1022篇
  2005年   937篇
  2004年   894篇
  2003年   799篇
  2002年   691篇
  2001年   237篇
  2000年   187篇
  1999年   212篇
  1998年   148篇
  1997年   130篇
  1996年   136篇
  1995年   113篇
  1994年   117篇
  1993年   119篇
  1992年   165篇
  1991年   192篇
  1990年   148篇
  1989年   127篇
  1988年   137篇
  1987年   105篇
  1986年   104篇
  1985年   111篇
  1984年   118篇
  1983年   105篇
  1982年   82篇
  1981年   80篇
  1980年   87篇
  1979年   86篇
  1978年   67篇
  1976年   71篇
  1975年   64篇
  1974年   83篇
  1973年   82篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
For patients who receive a liver transplant (LTX) for alcoholic liver disease (ALD), investigators are focusing beyond survival to determine specific alcohol use outcomes. Studies suggest the use of alcohol ranges from 8 to 22% for the first post-transplant year with cumulative rates reaching 30 to 40% by 5 years following transplantation. Yet while investigators are interested in determining specific rates of alcohol use and predictors of use, only three studies since 1990 have been prospective. In 1998, we began a prospective study of post-LTX alcohol consumption in ALD recipients using multiple repeated measures of alcohol use. After 5 years of follow-up, we found that 22% had used any alcohol by the first year and 42% had a drink by 5 years. By 5 years, 26% drank at a heavier use (binge) pattern and 20% drank in a frequent pattern. In a univariate model, predictors of alcohol use included pre-transplant length of sobriety, a diagnosis of alcohol dependence, a history of other substance use, and prior alcohol rehabilitation.  相似文献   
4.
5.
To test the reported antipanic efficacy of clonazepam, the authors randomized 72 subjects with panic disorder to 6 weeks of treatment with either alprazolam, clonazepam, or placebo. Endpoint analysis demonstrated a significant beneficial effect of both active treatments, but not placebo treatment, on the frequency of panic attacks, overall phobia ratings, and the extent of disability. Comparison of the two active treatments revealed no significant differences and no consistent tendency for one agent to be favored over another, although power to detect small differences was limited. Sedation and ataxia were the most common side effects reported, but these effects were mild and transient and did not interfere with treatment outcome. The results of this double-blind, placebo-controlled trial are consistent with previous reports of clonazepam's antipanic efficacy.  相似文献   
6.
Toxic effects of colloids in the intensive care unit.   总被引:4,自引:0,他引:4  
Colloid fluid solutions are frequently used as plasma volume expanders in the critically ill. As a group, these nonblood volume replacement solutions have in common a number of potential adverse effects. Intravascular volume overload, dilutional coagulopathy, extravascular extravasation across leaky capillary membranes, and anaphylactoid reactions may all occur with administration of any colloid. In addition, individual agents have unique toxic effects. Renal dysfunction has been associated with dextran 40, myocardial depression with albumin, hypotension with purified plasma protein, and hyperamylasemia with hetastarch. Because no ideal colloidal solution exists, knowledge of type, severity, and clinical significance of adverse effects is important in determining the appropriate plasma volume expander and monitoring its effects.  相似文献   
7.
Somatostatin (SRIF) in the central nervous system is mostly concentrated in the median eminence (ME). Immunocytochemical methods have revealed high densities of SRIF-positive perikarya between the preoptic area and the periventricular nucleus of the hypothalamus (NPE). The aim of the present study was to define more precisely the specific pathways of SRIF neurons from NPE to the ME. SRIF levels were measured by radioimmunoassay, following various hypothalamic transections. Frontal periventricular sections decreased SRIF-ME content by 70% (P less than 0.01), when located at the anterior end of the ME but no diminution was observed when the cuts were located anteriorly or posteriorly. Parasaggital transections decreased SRIF-ME levels by 50% (P less than 0.05) when located at the outer border of the ventromedial and premammillary nucleus, but the decrease was not significant when cuts were located anteriorly. Taken together, our data indicate that most SRIF-containing neurons, originating in the NPE, do not reach the ME directly along the border of the 3rd ventricle; instead they form a loop across the medial forebrain bundle before re-entering the mediobasal hypothalamus at the ME level.  相似文献   
8.
9.
L1 disease is the most common genetic cause of congenital hydrocephalus. Mutations in the L1CAM gene are associated with an overlapping clinical spectrum of four X-linked neurological conditions, characterized by hydrocephalus, mental retardation, lower limb spasticity and adducted thumbs. Brain anomalies are frequently present in L1 disease. We describe these anomalies by reporting a case of a male newborn presenting with congenital hydrocephalus along with corpus callosum agenesis and enlargement of the massa intermedia. These findings, in association with the presence of clasped thumbs, raised the suspicion of L1 disease, which was confirmed by the detection of a mutation in the L1CAM gene. In cases of congenital hydrocephalus, recognition of the brain anomalies associated with L1 disease may contribute to pursuing the genetic analysis needed for the diagnosis and genetic counseling.  相似文献   
10.
OBJECTIVE: The authors tested the effect of blood sampling (skin versus venous puncture) on some biochemical and hematological blood parameters in athletes to answer whether skin puncture could be used as a substitute for venous puncture. DESIGN: Comparative study of 2 methods of blood samples collection. SETTING: The blood was collected in the same athletes at 3 different moments of the preparatory training phase. PARTICIPANTS: Fourteen male indoor soccer players (22 +/- 1 years old) and 7 female handball players (18 +/- 1 years old) participated. MAIN OUTCOME MEASUREMENT: Blood was collected in heparin and K3EDTA by Vacutainer BD or Microvette Sarstedt system for biochemical and hematological analyses, respectively. RESULTS: There were no significant statistical differences between the 2 methods for the values of creatine kinase, urea, creatinine, lymphocytes, and platelets. The other hematological analyzes and uric acid exhibited significant higher values in skin blood, although they were all within the normal expected range. A high degree of correlation was observed between the 2 techniques for all parameters. CONCLUSIONS: Skin puncture is a reliable, easy, accurate, and less invasive sampling method for assessing hematological and some biochemical parameters in athletes, respecting that blood samples should always be obtained from the same site, especially in follow-up studies.  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