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   206372篇
  免费   33558篇
  国内免费   2891篇
耳鼻咽喉   5678篇
儿科学   6410篇
妇产科学   3869篇
基础医学   9786篇
口腔科学   3464篇
临床医学   30935篇
内科学   63087篇
皮肤病学   8413篇
神经病学   19679篇
特种医学   7996篇
外科学   49143篇
综合类   429篇
现状与发展   72篇
一般理论   9篇
预防医学   9841篇
眼科学   4130篇
药学   3905篇
中国医学   132篇
肿瘤学   15843篇
  2024年   718篇
  2023年   5130篇
  2022年   2116篇
  2021年   4779篇
  2020年   6930篇
  2019年   3524篇
  2018年   9127篇
  2017年   8481篇
  2016年   9712篇
  2015年   9954篇
  2014年   17617篇
  2013年   18478篇
  2012年   9929篇
  2011年   9914篇
  2010年   12781篇
  2009年   16359篇
  2008年   9604篇
  2007年   8013篇
  2006年   10199篇
  2005年   7420篇
  2004年   6436篇
  2003年   4998篇
  2002年   4723篇
  2001年   4138篇
  2000年   3242篇
  1999年   3552篇
  1998年   4093篇
  1997年   3846篇
  1996年   3676篇
  1995年   3534篇
  1994年   2197篇
  1993年   1773篇
  1992年   1548篇
  1991年   1547篇
  1990年   1186篇
  1989年   1273篇
  1988年   1098篇
  1987年   931篇
  1986年   989篇
  1985年   797篇
  1984年   642篇
  1983年   604篇
  1982年   612篇
  1981年   479篇
  1980年   439篇
  1979年   353篇
  1978年   381篇
  1977年   439篇
  1975年   309篇
  1972年   318篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
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   
94.
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   
95.
96.
97.
98.
99.
100.
Background contextLarge, prominent osteophytes along the anterior aspect of the cervical spine have been reported as a cause of dysphagia. Improvement of swallowing after surgical resection has been reported in a few case reports with short-term follow-up. The current report describes outcomes of a series of five patients with surgical treatment for this rare disorder, with a long-term follow-up.PurposeTo study the clinical and radiographic outcomes of a case series of patients surgically treated for dysphagia secondary to cervical diffuse idiopathic skeletal hyperostosis (DISH).Study designRetrospective review of a case series.Patient sampleFive cases from a University Hospital.Outcome measuresClinical and imagenological follow-up.MethodsThe records of five patients with dysphagia who had undergone anterior surgical resection of prominent osteophytes secondary to DISH were reviewed. Extrinsic esophageal compression secondary to anterior cervical osteophytes was radiographically confirmed via preoperative barium esophagogram swallowing study. All patients underwent anterior cervical osteophytes resection without fusion. Postoperatively, patients were followed-up clinically and radiographically with routine lateral cervical radiographs.ResultsPreoperative esophagogram showed that the esophageal obstruction was present at one level in three cases and two levels in two cases. The C3–C4 level was involved in three cases, C4–C5 in three cases, and C5–C6 in one case. There were no postoperative complications, including recurrent laryngeal nerve palsy, wound infection, or hematomas. All patients had resolution of dyphagia soon after surgery (within 2 weeks). Postoperative radiographs demonstrated complete removal of osteophytes. At final follow-up, ranging from 1 to 9 years (average 59.8 months, median 53 months), no patients reported recurrence of dysphagia. Final radiographic examination demonstrated minimal regrowth of the osteophytes.ConclusionsAlthough rarely indicated, surgical resection of anterior cervical osteophytes from DISH causing dyphagia produces good clinical and radiographical outcomes. After thorough evaluation to rule out other intrinsic or extrinsic causes of swallowing difficulty, surgical treatment of this uncommon condition might be considered.  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