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   69088篇
  免费   4119篇
  国内免费   1121篇
耳鼻咽喉   555篇
儿科学   1611篇
妇产科学   1755篇
基础医学   7573篇
口腔科学   1292篇
临床医学   5993篇
内科学   17499篇
皮肤病学   1230篇
神经病学   6195篇
特种医学   2510篇
外国民族医学   2篇
外科学   9919篇
综合类   2143篇
现状与发展   1篇
一般理论   6篇
预防医学   3255篇
眼科学   905篇
药学   5131篇
  8篇
中国医学   1000篇
肿瘤学   5745篇
  2023年   609篇
  2022年   1449篇
  2021年   2269篇
  2020年   1453篇
  2019年   1669篇
  2018年   1895篇
  2017年   1536篇
  2016年   1689篇
  2015年   2023篇
  2014年   2634篇
  2013年   3396篇
  2012年   4743篇
  2011年   4724篇
  2010年   2812篇
  2009年   2537篇
  2008年   4135篇
  2007年   4066篇
  2006年   3753篇
  2005年   3645篇
  2004年   3292篇
  2003年   2891篇
  2002年   2670篇
  2001年   1556篇
  2000年   1437篇
  1999年   1382篇
  1998年   647篇
  1997年   521篇
  1996年   489篇
  1995年   432篇
  1994年   391篇
  1993年   335篇
  1992年   751篇
  1991年   637篇
  1990年   618篇
  1989年   589篇
  1988年   501篇
  1987年   455篇
  1986年   448篇
  1985年   364篇
  1984年   312篇
  1983年   246篇
  1982年   166篇
  1981年   123篇
  1980年   130篇
  1979年   235篇
  1978年   143篇
  1977年   123篇
  1974年   142篇
  1973年   137篇
  1972年   132篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.
73.
Using radioimmunoassay methods, the blood of patients with pancreatic tumors was screened for circulating polypeptide hormones. This screening discovered pancreatic polypeptide in abnormally high concentration in the serum of six of seven patients with adenocarcinomas of the bile duct. the assay appears to be very sensitive finding excessive residual pancreatic polypeptide production after palliative resections. Serum pancreatic polypeptide assays warrant evaluation as an aid in the diagnosis and management of patients with bile duct tumors.  相似文献   
74.
For the past 10 years the alfa-hydroxyacids and the bovine collagen injection have been used for peeling and the correction of multiple skin diseases. Until now, such progressive achievement has occurred in separate parallels just like the indications that have been held distinct. However, the studies carried out in order to clarify the mechanical action of the two substances have shown a common and fundamental denominator: the stimulation of synthesis of the new collagen in the patient's skin. On the basis of these results and the existence of common clinical indications of the use of glycolic acid and collagen, the authors have worked out a protocol involving a combined and contemporary application in progressive steps. They developed the rationales of such protocol and analyzed the results of its application on a number of carefully selected patients for a clinical comparison and on a sample of rats for a histological comparison. They have concluded that the contemporary use of glycolic acid and bovine collagen is a simple and safe method whose synergy action leads to more intense and long-lasting effects than the ones observed in the isolated application of the two substances. The authors have also obtained interesting and significant histological results.  相似文献   
75.
BACKGROUND: In maintenance haemodialysis patients, daily food intake is changeable; however, its relationship with nutritional status is unexplored. This study aimed to evaluate the isolated, long-term effect of daily nutrient intake on nutritional status in haemodialysis patients. METHODS: We performed a prospective 1-year controlled study in 27 chronic haemodialysis patients, without recognized risk factors for malnutrition. Each day for 1 week, four times in the year, we measured protein nitrogen appearance, and assessed dietary protein (DPI) and energy (DEI) intake from dietary diaries. We compared the nutritional outcome of patients spontaneously reducing nutrient intake below the threshold of 0.8 g/kg body weight/day for DPI and 25 kcal/kg body weight/day for DEI during the week (LOW, n = 8), with controls at adequate nutrient intake (CON, n = 19). An interventional 6-month study was then carried out in LOW to verify the cause-effect relationship. RESULTS: All patients showed a day-by-day reduction of whole nutrient intake during interdialytic period, which was mostly relevant in the third interdialytic day (L3). During the 1-year study, even in the presence of adequate dialysis dose and normal inflammatory indexes, body weight (68.0 +/- 5.5 to 65.8 +/- 5.9 kg), serum albumin (3.96 +/- 0.07 to 3.66 +/- 0.06 g/dl) and creatinine (9.2 +/- 1.1 to 8.1 +/- 0.7 mg/dl) significantly decreased in LOW but not in CON. Diaries evidenced in LOW a reduced number of meals at L3 that was explained by the fear of excessive interdialytic weight gain. During the interventional study, daily DPI and DEI increased at L3; this was associated with a significant increment of body weight, and serum albumin and creatinine levels. CONCLUSIONS: In maintenance haemodialysis patients the persistent, marked reduction of daily nutrient intake, even if limited to a single day of the week, is an independent determinant of reversible impairment of nutritional status.  相似文献   
76.
77.
Ultrafiltration and solute transport during 60-min peritoneal dialyses of normal rabbits with intraperitoneal administration of phosphatidylcholine were compared to control values. The ultrafiltration rate of 0.27 mL/Kg/min did not increase when phosphatidylcholine was added. This agent had no effect on the ultrafiltration coefficient, sodium mass transport or solute clearances. Previously reported beneficial results with this agent could be due to repletion of a deficiency or an effect of the organic solvent. More studies of safety and efficacy of phosphatidylcholine are warranted before widespread clinical use.  相似文献   
78.
Sir, We are writing to provide some clarifications on the EditorialComment by Drüeke et al. [1]. We would have been happyto provide these very same clarifications had we been fairlyinvited to do so before the publication of the article. First of all, we would like to  相似文献   
79.
80.
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