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   161152篇
  免费   32358篇
  国内免费   2423篇
耳鼻咽喉   5233篇
儿科学   5761篇
妇产科学   2635篇
基础医学   4386篇
口腔科学   1811篇
临床医学   27817篇
内科学   49107篇
皮肤病学   7582篇
神经病学   15685篇
特种医学   6702篇
外科学   42728篇
综合类   628篇
现状与发展   72篇
一般理论   30篇
预防医学   7989篇
眼科学   3501篇
药学   1849篇
中国医学   11篇
肿瘤学   12406篇
  2024年   685篇
  2023年   4827篇
  2022年   1242篇
  2021年   3174篇
  2020年   6106篇
  2019年   2274篇
  2018年   7516篇
  2017年   7433篇
  2016年   8487篇
  2015年   8505篇
  2014年   15676篇
  2013年   15902篇
  2012年   5829篇
  2011年   5866篇
  2010年   10535篇
  2009年   14440篇
  2008年   6180篇
  2007年   4459篇
  2006年   6895篇
  2005年   4208篇
  2004年   3405篇
  2003年   2368篇
  2002年   2408篇
  2001年   4230篇
  2000年   3408篇
  1999年   3557篇
  1998年   3779篇
  1997年   3554篇
  1996年   3473篇
  1995年   3310篇
  1994年   2053篇
  1993年   1669篇
  1992年   1715篇
  1991年   1707篇
  1990年   1353篇
  1989年   1456篇
  1988年   1269篇
  1987年   1113篇
  1986年   1151篇
  1985年   964篇
  1984年   736篇
  1983年   683篇
  1982年   649篇
  1981年   505篇
  1980年   447篇
  1979年   440篇
  1978年   425篇
  1977年   481篇
  1975年   373篇
  1972年   404篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
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   
82.
83.
84.
85.
86.
87.
88.
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   
89.
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   
90.
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