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   40087篇
  免费   1957篇
  国内免费   172篇
耳鼻咽喉   308篇
儿科学   696篇
妇产科学   479篇
基础医学   5273篇
口腔科学   1129篇
临床医学   2691篇
内科学   10490篇
皮肤病学   803篇
神经病学   2891篇
特种医学   1521篇
外科学   6510篇
综合类   154篇
一般理论   1篇
预防医学   1351篇
眼科学   721篇
药学   2791篇
中国医学   74篇
肿瘤学   4333篇
  2023年   195篇
  2022年   440篇
  2021年   741篇
  2020年   373篇
  2019年   522篇
  2018年   688篇
  2017年   551篇
  2016年   663篇
  2015年   691篇
  2014年   896篇
  2013年   1130篇
  2012年   1788篇
  2011年   2058篇
  2010年   1104篇
  2009年   1038篇
  2008年   1798篇
  2007年   1960篇
  2006年   1986篇
  2005年   1948篇
  2004年   1860篇
  2003年   1956篇
  2002年   1952篇
  2001年   1509篇
  2000年   1490篇
  1999年   1310篇
  1998年   544篇
  1997年   414篇
  1996年   354篇
  1995年   310篇
  1994年   270篇
  1993年   276篇
  1992年   937篇
  1991年   829篇
  1990年   769篇
  1989年   764篇
  1988年   702篇
  1987年   703篇
  1986年   616篇
  1985年   589篇
  1984年   376篇
  1983年   320篇
  1982年   171篇
  1979年   249篇
  1978年   191篇
  1977年   155篇
  1975年   156篇
  1974年   160篇
  1973年   171篇
  1969年   156篇
  1967年   156篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Since somatostatin is a local hormone controlling gastric acid secretion and gastrin release, quantitative histopological distribution of the G-cells and D-cells in the canine whole stomach was investigated by the specific immunoperoxidase staining technique. The G-cells were identified only in the pyloric antrum and the estimated total number of G-cells was 15.5 X 10(6) cells. Most of the D-cells were also found in the pyloric antrum but a few were found scattered diffusely throughout body and fundus of the stomach. The estimated total number of D-cells was 11 X 10(6) cells in the pyloric antrum and 4 X 10(6) cells in the corpus and fundus. The G-/D-cell ratio in the antrum was 1.4:1. The number of G-cells as well as D-cells per unit mucosal surface area was significantly higher on the greater curvature and the proximal part of the antrum than on other areas of the antrum. Thus, the pattern of distribution in G-cells was similar to that of D-cells and there was a highly significant correlation between G- and D-cells per unit mucosal surface area. It would appear that under normal conditions, the number of G- and D-cells in the antrum are in good balance and may play an important role in the control mechanisms related to gastric secretion.  相似文献   
62.
63.
A black adenoma of the adrenal cortex was surgically removed from an 18-year-old female who had clinical and laboratory findings characteristic of Cushing's syndrome. The electron microscopic study revealed typical features of steroid-producing cells, including a prominent smooth and rough endoplasmic reticulum, and mitochondria. In addition, many of the adenoma cells contained numerous pigmented granules which were lipofuscin. Three months after the surgery, the hormone levels returned to the normal range. The Japanese literature of functional black adenoma is reviewed.  相似文献   
64.
65.
66.
S-8666, [6, 7-dichloro-5-(N, N-dimethylsulfamoyl)-2, 3-dihydrobenzofurancarboxylic acid] is a potent diuretic with uricosuric action. Although the major site of action of S-8666 has been proven by the in vitro microperfusion study to be the thick ascending limb of Henle's loop, clearance studies in the rat suggested that this drug has an additional thiazide-like action. To provide direct evidence that S-8666 acts also on distal nephron segments, we examined effect of S-8666 on Cl- flux across the rabbit connecting tubule perfused in vitro. The drug suppressed the lumen-to-bath Cl- flux by 96 +/- 41 (S.E.)pmol.mm-1.min-1 (n = 9) without affecting transmural voltage. To demonstrate that S-8666 acts on the connecting tubule cell, the target of thiazide diuretics, we compared effects of S-8666 and trichlormethiazide on the basolateral membrane voltage of the connecting tubule cell. Both drugs added to the lumen caused a small but significant hyperpolarization of the basolateral membrane without affecting transmural voltage. We conclude that S-8666 is a unique uricosuric diuretic having actions on both thick ascending limb of Henle's loop and connecting tubule.  相似文献   
67.
Endoscopic placement of metal stents are used widely for patients with esophageal obstruction and fistula due to progressive esophageal cancer, but cause high rate of severe complications associated with the immediate causes of death. To determine severe complications caused by stents, we studied clinical data and autopsy of six patients who had been treated with stents for inoperable progressive esophageal cancer. Occording to the clinical records only two patients had severe complications due to stents. But at autopsy, three patients had massive hemorrhage in the stent placement, one patient had mediastinitis, and one patient were in imminent danger of perforation whose stent had been incorporated into the adventitia of the wall. More severe complications were revealed than those expected clinically. Endoscopic placement of metal stents have a great deal for the improvement of quality of life. But we should carefully decide the indication because endoscopic placement of metal stents could cause severe complications associated with the immediate causes of death.  相似文献   
68.
69.
70.
We report on a male patient with Pick disease who had shown severe white matter atrophy and dilatation of the lateral ventricle in the frontal lobe from an early stage. Upon admission to our hospital 2 years after disease onset, the patient showed apathy, and MRI revealed severe atrophy of the cortex and white matter of the frontal lobe. He died at age 74, 11 years after disease onset. Autopsy revealed severe atrophy of the frontal and temporal lobes, severe loss of white matter in the frontal lobe, dilatation of the lateral ventricles, and cortical thinning. Histopathological examination showed severe loss of myelinated fibers in the frontal white matter and severe neuronal loss with gliosis in the frontal and temporal cortices. Many Pick bodies were seen. Our patient had a rare case of Pick disease predominantly affecting the frontal lobe with severe involvement of the white matter from an early stage. This case suggests that myelinated fibers in the white matter as well as cerebral neurons are primarily affected in Pick disease.  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