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   150719篇
  免费   31250篇
  国内免费   2406篇
耳鼻咽喉   5179篇
儿科学   5349篇
妇产科学   2405篇
基础医学   3165篇
口腔科学   1482篇
临床医学   26600篇
内科学   47244篇
皮肤病学   7440篇
神经病学   14723篇
特种医学   6375篇
外科学   40969篇
综合类   252篇
现状与发展   73篇
预防医学   6988篇
眼科学   3350篇
药学   1023篇
中国医学   24篇
肿瘤学   11734篇
  2024年   684篇
  2023年   4788篇
  2022年   1193篇
  2021年   3086篇
  2020年   6017篇
  2019年   2146篇
  2018年   7371篇
  2017年   7336篇
  2016年   8415篇
  2015年   8419篇
  2014年   15486篇
  2013年   15612篇
  2012年   5463篇
  2011年   5500篇
  2010年   10348篇
  2009年   14215篇
  2008年   5744篇
  2007年   3996篇
  2006年   6456篇
  2005年   3727篇
  2004年   2988篇
  2003年   1945篇
  2002年   2060篇
  2001年   3827篇
  2000年   3026篇
  1999年   3224篇
  1998年   3646篇
  1997年   3457篇
  1996年   3367篇
  1995年   3220篇
  1994年   1943篇
  1993年   1558篇
  1992年   1372篇
  1991年   1411篇
  1990年   1059篇
  1989年   1176篇
  1988年   1021篇
  1987年   850篇
  1986年   892篇
  1985年   730篇
  1984年   551篇
  1983年   523篇
  1982年   513篇
  1981年   406篇
  1980年   362篇
  1979年   310篇
  1978年   331篇
  1977年   399篇
  1975年   280篇
  1972年   303篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
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   
82.
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   
83.
84.
85.
86.
87.
88.
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   
89.
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