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   152214篇
  免费   31316篇
  国内免费   2412篇
耳鼻咽喉   5171篇
儿科学   5383篇
妇产科学   2385篇
基础医学   3312篇
口腔科学   1543篇
临床医学   26733篇
内科学   47804篇
皮肤病学   7492篇
神经病学   14796篇
特种医学   6424篇
外科学   41145篇
综合类   240篇
现状与发展   72篇
预防医学   6968篇
眼科学   3385篇
药学   1008篇
中国医学   16篇
肿瘤学   12065篇
  2024年   689篇
  2023年   4813篇
  2022年   1252篇
  2021年   3175篇
  2020年   6061篇
  2019年   2206篇
  2018年   7432篇
  2017年   7377篇
  2016年   8484篇
  2015年   8460篇
  2014年   15533篇
  2013年   15682篇
  2012年   5547篇
  2011年   5549篇
  2010年   10419篇
  2009年   14260篇
  2008年   5843篇
  2007年   4081篇
  2006年   6543篇
  2005年   3828篇
  2004年   3084篇
  2003年   2055篇
  2002年   2173篇
  2001年   3798篇
  2000年   3004篇
  1999年   3216篇
  1998年   3663篇
  1997年   3480篇
  1996年   3379篇
  1995年   3220篇
  1994年   1959篇
  1993年   1578篇
  1992年   1379篇
  1991年   1406篇
  1990年   1053篇
  1989年   1183篇
  1988年   1012篇
  1987年   855篇
  1986年   886篇
  1985年   717篇
  1984年   549篇
  1983年   524篇
  1982年   515篇
  1981年   402篇
  1980年   365篇
  1979年   311篇
  1978年   331篇
  1977年   398篇
  1975年   280篇
  1972年   304篇
排序方式: 共有10000条查询结果,搜索用时 1 毫秒
71.
Although lesions of the pterygopalatine space are uncommon, there are instances in which this relatively inaccessible region must be entered for biopsy or excision of masses. Traditional open approaches to the pterygopalatine space, involving external or intraoral incisions, provide limited visualization and carry associated morbidities. The evolution and advancement of endoscopic sinus surgical technique in recent years has led to its application to anatomic areas outside the strict limits of the sinonasal cavities. Such minimally invasive approaches are safe, effective, and spare unnecessary discomfort to the patient. This article describes the authors' method for performing an endoscopic approach to the pterygopalatine space.  相似文献   
72.
73.
74.
75.
76.
77.
78.
Three patients with dysphagia caused by compression of the distal esophagus by a tortuous nonaneurysmal atherosclerotic aorta are described. All three patients were elderly women; systemic hypertension and cardiomegaly were present in two patients. Barium studies of the esophagus showed displacement and compression of the distal esophagus by the thoracic aorta. Debilitating dysphagia was treated surgically in one patient. The other two patients had milder symptoms and were managed conservatively. Esophageal manometry in these three patients showed superimposed pulsations and elevated intraluminal pressure just proximal to the lower esophageal sphincter. To evaluate the significance of these manometric findings and their correlation with clinical symptoms, we reviewed manometric tracings in 47 normal subjects. Ten of these subjects had an elevation of baseline intraluminal esophageal pressure as a result of superimposed vascular pulsations. We conclude that (1) compression of the distal esophagus by a tortuous atherosclerotic aorta in the appropriate setting can lead to clinically significant dysphagia and (2) a manometric finding of vascular compression of the esophagus does not necessarily correlate symptomatic dysphagia.  相似文献   
79.
MICHELLE EHRLICH  MD    JAGGI RAO  MD    ANJU PABBY  MD    MITCHEL P. GOLDMAN  MD 《Dermatologic surgery》2006,32(5):618-625
BACKGROUND AND OBJECTIVE: Facial rhytides are a common cosmetic concern. Surgical treatment effects dramatic improvement; however, the associated risk and cost may be prohibitive. Recent focus is on developing topical products containing biologically active ingredients for at-home therapy. Our study examines the effects of a topical cream containing transforming growth factor-beta(1) (TGF-beta(1)), l-ascorbic acid, and Cimicifuga racemosa extract (CRS) (Topix Pharmaceuticals, North Amityville, NY, USA). MATERIALS AND METHODS: In the first arm of the study, 12 subjects were randomized to apply CRS to the left or right side of their face and a cream containing l-ascorbic acid and C. racemosa in silicone base (vitamin C [Vit C]) to the contralateral side twice daily for 3 months. In the second arm of the study, 20 subjects were randomized to apply CRS to the left or right side of their face and Tissue Nutrient Solution Recovery Complex (TNS) (SkinMedica, Carlsbad, CA, USA), a product containing a variety of growth factors including VEGF, PDGF-A, G-CSF, HGF, IL-6, IL-8, and TGF-beta(1) (Nouricel-MD) without l-ascorbic acid, C. racemosa extract, or silicone base, to the contralateral side of their face twice daily for 3 months. Digital photographs were scored by study-blinded physicians, and self-assessments were completed by all subjects at baseline and at the conclusion of the protocol. RESULTS: CRS and TNS were well tolerated, and all subjects completed the 3-month protocol for the CRS versus Vit C arm of the study. Physicians rated success in facial wrinkling scores on the CRS-treated side of the face for 27 of 31 subjects. Responders showed, on average, 21.7% improvement in physician-rated wrinkle scores. The mean improvement in the group of 31 patients as a whole was 12%. Eighteen of 31 subjects reported a noticeable improvement on their CRS-treated side. Both CRS and TNS demonstrate significant success between baseline and 3-month scores, and both growth factor products are superior to Vit C. Patients preferred CRS over TNS. CONCLUSION: CRS is effective in minimizing the appearance of facial rhytides. The success of the CRS product is largely attributable to the incorporation of TGF-beta(1).  相似文献   
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