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   707篇
  免费   30篇
  国内免费   15篇
儿科学   10篇
基础医学   127篇
临床医学   67篇
内科学   147篇
皮肤病学   2篇
神经病学   42篇
特种医学   26篇
外国民族医学   1篇
外科学   95篇
综合类   117篇
预防医学   17篇
药学   50篇
中国医学   17篇
肿瘤学   34篇
  2024年   2篇
  2023年   2篇
  2022年   11篇
  2021年   20篇
  2020年   13篇
  2019年   14篇
  2018年   8篇
  2017年   16篇
  2016年   6篇
  2015年   13篇
  2014年   24篇
  2013年   47篇
  2012年   19篇
  2011年   23篇
  2010年   24篇
  2009年   27篇
  2008年   43篇
  2007年   30篇
  2006年   22篇
  2005年   35篇
  2004年   24篇
  2003年   19篇
  2002年   26篇
  2001年   31篇
  2000年   18篇
  1999年   26篇
  1998年   20篇
  1997年   17篇
  1996年   18篇
  1995年   14篇
  1994年   10篇
  1993年   9篇
  1992年   15篇
  1991年   10篇
  1990年   15篇
  1989年   16篇
  1988年   10篇
  1987年   12篇
  1986年   12篇
  1985年   4篇
  1984年   4篇
  1983年   1篇
  1982年   6篇
  1981年   3篇
  1980年   1篇
  1979年   2篇
  1978年   7篇
  1977年   1篇
  1976年   1篇
  1973年   1篇
排序方式: 共有752条查询结果,搜索用时 15 毫秒
1.
Background and Aim: Duodenal lymphangitis carcinomatosa has been sporadically described, but so far little attention has been paid to duodenal lymphangitis carcinomatosa. Methods: Four cases with duodenal lymphangitis carcinomatosa were endoscopically and histologically examined. Results: The four cases exhibited multiple polypoid lesions along the Kerckring's folds and/or were covered by characteristically granular, non‐ulcerated mucosa upon thickening. The granularity seems to been caused by dilated lymph vessels containing the carcinoma cells. The lesions were microscopically characterized by: (i) involvement of lymph vessels located in the upper portion of the lamina propria; (ii) no inflammatory changes; and (iii) no desmoplastic changes. Primary sites were thought to be the stomach in case 1, the pancreas in cases 2 and 4, and unknown in case 3. All patients died within 6 months after admission or endoscopic examination. Conclusions: As duodenal lymphangitis carcinomatosis shows characteristic endoscopic appearance, endoscopic diagnosis is not difficult. We should realize that the lesion represents extremely poor prognosis, and it should be distinguished from ordinary metastatic duodenal carcinoma.  相似文献   
2.
Paraganglioma is a neoplasm of neuroectodermal origin that occurs rarely in the bowel. This case report illustrates the previously undescribed CT appearance of a duodenal paraganglioma. An intensely enhancing mass in the region of the pancreatic head was found. The intense enhancement ruled out adenocarcinoma and focal pancreatitis. An islet cell tumor of the pancreas was the major differential diagnostic consideration.  相似文献   
3.
Abstract While the volume of a liquid meal has been identified as the principal accelerator of gastric emptying of liquids, the relationship between meal volume and gastric emptying of solids has been controversial. With solid foods, the need to reduce solid foods into small particles (trituration) before passage might obscure the effect of meal volume on solid propulsion. To distinguish trituration from driving force as the rate-limiting factor for emptying, 75 (1.6 mm) nylon spheres were fed along with different amounts of steak meals (150, 300 and 600 g), or alternatively, 50, 100 or 200 (1.6 mm) nylon spheres were fed to six dogs with 300 g steak meals. To examine the effect of meal volume on gastric emptying, we studied the effect of different meal volumes on the speed of gastric emptying of liquids (150, 300, 600 and 1200 ml of phosphate buffer) and solids (150, 300 and 600 g of cooked beef steak) in five dogs with duodenal fistulas. Intestinal inhibition was eliminated by diverting all chyme through the fistulas. In the absence of intestinal feedback, we found that gastric emptying of steak and spheres were different in that steak emptying was independent of meal volume (g min-1 was constant across 150–600 g) while sphere emptying was affected by the number of spheres in the stomach and that liquid emptying was dependent on the meal volume (ml min-1 increased across 150–1200 ml). Thus, meal volume accelerated gastric emptying provided the process is not rate-limited by trituration.  相似文献   
4.
原发性十二指肠肿瘤的诊断与治疗   总被引:1,自引:0,他引:1  
目的 探讨十二指肠肿瘤的诊断及治疗。方法 回顾我院1984~2005年间收治29例PTD的临床资料进行分析。结果 良性肿瘤8例,恶性肿瘤21例。上腹部疼痛、消化道出血、呕吐、黄疸、消瘦、腹部包块等为本组病人的主要临床表现。术前十二指肠镜检查6例,均发现病灶。胃镜检查18例,9例发现病灶。B超检查20例,12例发现包块。十二指肠气钡双重造影7例,6例确诊。CT检查5例,4例确诊。全组病人均行手术治疗,术后随访6个月~21年。良性肿瘤均存活,恶性肿瘤死亡儿例,2年内死亡10例,5年死亡1例,10例生存,最长1例20年。结论 上腹部疼痛、消化道出血、呕吐是十二指肠肿瘤的最常见症状。十二指肠镜、十二指肠气钡双重造影、胃镜检查是最主要的检查手段;手术切除肿瘤是最基本、最有效的治疗方法。  相似文献   
5.
6.
胆总管的矢状断层解剖研究   总被引:1,自引:0,他引:1  
刘树伟  王凡 《解剖学杂志》1993,16(5):391-394
在30套成人腹部连续矢状断层标本上,胆总管与下腔静脉主要出现于R2-R3断层;胆总管胰腺段与胰头的关系有部分包埋,完全包埋及胰腺后型;十二指肠大乳头集中出现于R3断层;胆总管的行程有4种形式。文内还探讨了矢状断层里胆总管各段的毗邻及识别标志。  相似文献   
7.
Duodenal mucosal alkaline secretion increases in response to hydrochloric acid exposure. The tentative role of nitric oxide (NO) in the mediation of this response was investigated. The mucosal alkaline output by a duodenal segment was recorded by in situ titration in chloralose-anaesthetized rats. In some experiments the duodenal blood flow was estimated by laser-Doppler flowmetry. Exposure of the duodenum to acid (0.01 M HCl, 5 min) increased the alkaline secretion by ≈85%. The NO synthase inhibitor NG-nitro-L -arginine methyl ester (L -NAME, 10 mg kg?1 intravenously or 0.3 mM intraluminally) blocked the secretory increment after mucosal acid exposure. Mean arterial pressure and basal alkaline secretion were markedly raised, whereas duodenal blood flow was decreased, when L -NAME was given intravenously (i.v.). Intraluminal (i.l.) administration left mean arterial pressure as well as duodenal blood flow unaltered, and the duodenal mucosal alkaline secretion was only slightly elevated. The stereoisomer NG-nitro-D -arginine methyl ester (D -NAME) had no effect on either basal or acid-induced duodenal alkaline output. In animals receiving L -arginine (10 mg kg?1 min?1 i.v., or 3 mM i.l.) and L -NAME, the acid exposure elicited an increase in duodenal mucosal alkaline secretion, similar to that observed in controls. The results suggest that the acid-induced increase in duodenal mucosal alkaline secretion involves NO synthesis, which takes place close to the lumen, probably within the mucosa.  相似文献   
8.
脂糖舒对大鼠离体小肠运动的影响   总被引:4,自引:2,他引:2  
观察纯中药复方脂糖舒对小肠运动的影响。方法:大鼠随机分组,采用离休肠平滑肌实验装置,应用三种不同浓度脂糖舒(0.20%、0.60%、1.20%),观察其对离体十二指肠和回肠自发运动的作用及高浓度脂糖舒(1.20%)对乙酰胆碱、氯化钡、肾上腺素的拮抗作用。结果:各浓度脂糖舒对十二指肠自发运动均有抑制作用,且随剂量增大而增强;高浓度脂糖舒对乙酰胆碱、氯化钡、紧不素有拮抗作用,对乙酰胆碱的拮抗作用最明显  相似文献   
9.
Vascular anatomy of the pancreaticoduodenal region: A review   总被引:4,自引:0,他引:4  
Vascular anatomy of the pancreaticoduodenal region has been the subject of numerous studies. However, several essential areas of confusion remain in interpretation of the vascular configuration. We note and discuss three key points in relation to this confusion: (1) a missing vascular arcade, (2) a rearrangement of the arcade by collateral and/or transverse vessels, and (3) a solitary vessel without an accompanying comites vein or artery. In addition, we consider that different interpretations as well as varying reported incidences depend on different "thresholds" when observations are made. Consideration of new aspects of vascular anatomy of the pancreaticoduodenal region is required for further improvement of surgical procedures. In terms of the selection of lymph node resection procedure, we discuss mainly the inferior arterial origin. Special attention should be paid to the ligation of inferior arteries because of the high incidence of the common trunk formation of the upper jejunal and inferior pancreaticoduodenal arteries. With regard to duodenum-preserving pancreatic head resection for benign tumors, our observations are introduced in view of either arterial or venous configuration. First, a communicating artery between the anterior and posterior arterial arcades is noted because of its possible critical role in blood supply to the papilla of Vater. Second, a venous drainage route from the duodenum to the retroperitoneal space in "normal" specimens is described. Received for publication on June 17, 1998; accepted on July 27, 1998  相似文献   
10.
目的 探讨在体胃、十二指肠协调运动的实验方法学。方法 青紫蓝兔胃、十二指肠水囊植入 ,应用计算机生物信号分析系统 ,记录生理状态、运动低下、运动亢进动物胃、十二指肠运动。结果  3种不同功能状态下的胃、十二指肠运动协调性实时记录结果与理论预测运动形式相符合 ,无显著性差异 ,P >0 .0 5。结论 水囊植入法适于胃、十二指肠运动协调性的实验研究  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