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   18966篇
  免费   863篇
  国内免费   96篇
耳鼻咽喉   236篇
儿科学   304篇
妇产科学   221篇
基础医学   2467篇
口腔科学   539篇
临床医学   1260篇
内科学   4520篇
皮肤病学   241篇
神经病学   1348篇
特种医学   956篇
外科学   3507篇
综合类   88篇
现状与发展   1篇
一般理论   1篇
预防医学   539篇
眼科学   368篇
药学   1245篇
中国医学   27篇
肿瘤学   2057篇
  2023年   126篇
  2022年   240篇
  2021年   384篇
  2020年   223篇
  2019年   283篇
  2018年   340篇
  2017年   290篇
  2016年   388篇
  2015年   404篇
  2014年   514篇
  2013年   597篇
  2012年   984篇
  2011年   1065篇
  2010年   618篇
  2009年   576篇
  2008年   946篇
  2007年   1050篇
  2006年   1035篇
  2005年   996篇
  2004年   1030篇
  2003年   1005篇
  2002年   965篇
  2001年   484篇
  2000年   528篇
  1999年   491篇
  1998年   247篇
  1997年   211篇
  1996年   186篇
  1995年   155篇
  1994年   151篇
  1993年   141篇
  1992年   374篇
  1991年   330篇
  1990年   293篇
  1989年   259篇
  1988年   257篇
  1987年   227篇
  1986年   194篇
  1985年   175篇
  1984年   141篇
  1983年   122篇
  1979年   71篇
  1978年   64篇
  1977年   55篇
  1975年   61篇
  1973年   48篇
  1972年   57篇
  1971年   48篇
  1968年   61篇
  1967年   65篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
The calcifying cystic odontogenic tumor is a rare benign odontogenic lesion. This report documents a case of this lesion associated with odontoma arising from the anterior maxilla in a 14-year-old boy. The diagnosis was confirmed based on computerized tomography findings, which clearly depicted the internal structures obscured in conventional images.  相似文献   
53.
A 75-year-old man was admitted to our hospital with the chief complaint of a choking feeling around the esophagus. Laboratory examinations revealed eosinophilia, and high levels of serum immunoglobulin (Ig) E. A computed tomography scan (CT) showed wall thickening of the esophagus and terminal ileum, and ascites around the liver. An endoscopic examination revealed mild mucosal edema in the esophagus, stomach, and small intestine. Biopsy specimens showed diffuse eosinophilic infiltration in the mucosa. We therefore diagnosed eosinophilic gastroenteritis. Oral prednisolone relieved clinical conditions and the CT image improved. This case was considered valuable, because there have been few reports of eosinophilic esophagitis in Japan.  相似文献   
54.
55.
Although the causes of stroke are diverse, thromboembolism due to a mobile aortic thrombus is rare. We describe a surgical case of acute massive pulmonary embolism after critical cerebral infarction associated with a mobile ascending aortic thrombus in a 52-year-old woman. Concomitant surgical removal of the aortic thrombus and pulmonary embolectomy was performed successfully, and the patient has been stable without recurrent thromboembolic complications after 18 months of follow-up.  相似文献   
56.
Phototransduction mechanisms have been so far investigated mostly in rods, whereas those in cones are much less known. In the present experiment, we investigated phototransduction mechanisms in inside-out patches excised from cone outer segments of the carp. Cyclic GMP-activated channels on the patch became light-sensitive when both GTP and Mg2+ were supplied by perfusion. When the channels were activated by a hydrolysis-resistant analogue of cGMP, activities were not suppressed by light even though both GTP and Mg2+ were present. Thus activation of transducin and phosphodiesterase (PDE) were involved in the transduction processes, indicating that phototransduction mechanisms in cones are qualitatively similar to those in rods. In cone patches, however, light responses fully terminated even though ATP was absent, opposing to the report that ATP was indispensable for light response termination in rods. The response termination in the cone patch might result from activation of guanylate cyclase and/or inactivation of PDE. Under the perfusion of GTP together with Mg2+ and 3-isobutyl-1-methyl xanthine, no channel activities were observed, indicating that no guanylate cyclase activity was present in cone patch preparations. Therefore, termination of the light response in the patch might be caused by inactivation of PDE which resulted from inactivation of photopigment and transducin. Based on these observations, differences in light response kinetics between the rod and cone are discussed.  相似文献   
57.
58.
To clarify the physiological role of the mechanism that adrenergic nerve inhibits Ach release from intramural cholinergic nerve endings, the influence of Midaglizole, alpha 2-adrenergic receptor antagonist, to postprandial gastrointestinal motilities in conscious dogs was investigated. Postprandial motilities of gastric antrum, duodenum, ileum, and colon were significantly enhanced by Midaglizole (3.0-5.0 mg/kg body weight, i.v.). These excitatory responses were abolished by atropine (0.05-0.1 mg/kg body weight, i.v.). On the other hand, in most cases (29 cases out of 32), when Midaglizole was administered during quiesent phase of IMC, no change occurred in gastrointestinal motility. However, after subliminal dose of pentagastrin or cisapride, which stimulated Ach release from intramural cholinergic neuron without development of motility, was administered, Midaglizole induced phasic, postprandial motility-like contraction in gastrointestinal tract. Even in the fasted state, when Midaglizole was administered intragastrically, irregular contractions with high amplitude occurred in every regions from gastric antrum to colon. And these excitatory responses were abolished by atropine. Similar reaction was observed also in truncal vagotomized dogs. These results suggest that it is the physiological mechanism that adrenergic nerve presynaptically inhibits Ach release from intramural cholinergic neuron, which is the main mechanism of development of postprandial motility, acting on alpha 2-adrenergic receptor, and has tonic control of postprandial motility.  相似文献   
59.
60.
Pyoderma gangrenosum is a rare, chronic, inflammatory ulcerative skin disease of unknown etiology and pathogenesis. It is often associated with systemic disease. We describe a patient with pyoderma gangrenosum associated with ulcerative colitis and aseptic abscesses of the subcutis and spleen, which have been rarely reported previously. These manifestations were cleared by combined therapy with minocycline hydrochloride and diaphenylsulfone.  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