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   20101篇
  免费   1203篇
  国内免费   656篇
耳鼻咽喉   147篇
儿科学   360篇
妇产科学   147篇
基础医学   1749篇
口腔科学   103篇
临床医学   2915篇
内科学   3793篇
皮肤病学   59篇
神经病学   864篇
特种医学   1528篇
外国民族医学   3篇
外科学   3626篇
综合类   2869篇
现状与发展   1篇
预防医学   423篇
眼科学   1115篇
药学   1296篇
  9篇
中国医学   421篇
肿瘤学   532篇
  2024年   37篇
  2023年   321篇
  2022年   509篇
  2021年   731篇
  2020年   693篇
  2019年   614篇
  2018年   556篇
  2017年   617篇
  2016年   602篇
  2015年   640篇
  2014年   1184篇
  2013年   1233篇
  2012年   1140篇
  2011年   1212篇
  2010年   1042篇
  2009年   1011篇
  2008年   1087篇
  2007年   1057篇
  2006年   984篇
  2005年   864篇
  2004年   746篇
  2003年   618篇
  2002年   520篇
  2001年   438篇
  2000年   347篇
  1999年   305篇
  1998年   330篇
  1997年   327篇
  1996年   224篇
  1995年   217篇
  1994年   205篇
  1993年   160篇
  1992年   160篇
  1991年   134篇
  1990年   116篇
  1989年   89篇
  1988年   117篇
  1987年   93篇
  1986年   100篇
  1985年   94篇
  1984年   78篇
  1983年   41篇
  1982年   67篇
  1981年   67篇
  1980年   50篇
  1979年   56篇
  1978年   37篇
  1977年   24篇
  1976年   23篇
  1974年   11篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
AimThe purpose of this study was to evaluate the efficiency of pyramidal and posterior osseous release (PPOR) for maxillary impaction using an ultrasonic bone-cutting device after Le Fort I (LFI) osteotomy.Materials and methodsIn total, 31 Japanese adults with jaw deformities, diagnosed as having maxillary excess with mandibular prognathism or deficiency, underwent LFI osteotomy and bilateral sagittal split osteotomy. The patients were divided into two groups: a trimming group (15 patients, four men and 11 women; mean age 24.8 years) and a PPOR group (16 patients, seven men and nine women; mean age 22.8 years). In the trimming group, osseous interference around the descending palatine artery (DPA) was removed using forceps, rounding bur, and reciprocating rasp. The PPOR technique was used to remove osseous fragments created by V-shaped osteotomy around the DPA following vertical osteotomy behind the DPA using an ultrasonic bone-cutting device (Variosurg 3; NSK, Tochigi, Japan). The operative times for maxillary osteotomy, total operative times (including bilateral sagittal split osteotomy), and total blood loss were assessed.ResultsThe mean planned amounts of maxillary impaction were 4.37 ± 1.27 mm in the trimming group and 4.38 ± 1.36 mm in the PPOR group (p = 0.98). The mean maxillary operative time for the PPOR group was significantly shorter, by 25.5% (p < 0.001). Total operative time for the PPOR group was also significantly shorter, by 24.3% (p < 0.001). Mean blood loss was significantly lower in the PPOR group than in the trimming group (p = 0.003).ConclusionThe PPOR technique for maxillary impaction after LFI osteotomy shortened the operative time and enabled secure reduction of the maxilla in patients who required the treatment of maxillary impaction with preservation of the DPA bundle.  相似文献   
3.
4.
ObjectiveThe objective of this study was to investigate the association between morphological variation and postsurgical pulmonary vein (PV) stenosis (PPVS) in patients with cardiac total anomalous pulmonary venous connection (TAPVC).MethodsThis single-center, retrospective study included 168 pediatric patients who underwent surgical repair of cardiac TAPVC from 2013 to 2019 (connection to the coronary sinus [CS], n = 136; connection directly to the right atrium [RA], n = 32). Three-dimensional computed tomography modeling and geometric analysis were performed to investigate the morphological features; their relevance to the PPVS was examined.ResultsThe connection type had no association with PPVS (CS type: 18% vs right atrial type: 19%; P = .89) but there was a higher incidence of PPVS in patients with a single PV orifice than > 1 orifice (P < .001). Confluence-to-total PV area ratio (hazard ratio, 4.78, 95% CI, 1.86-12.32; P = .001) and length of drainage route (hazard ratio, 1.22; 95% CI, 1.14-1.31; P < .001) had a 4- and 1-fold increase in the risk for PPVS in the CS type after adjustment for age and preoperative pulmonary venous obstruction. In the right atrial type, those with anomalous PV return to the RA roof were more likely to develop PPVS than to the posterior wall of the RA (P < .001).ConclusionsThe number of inter-junction PV orifice correlated with PPVS development in cardiac TAPVC. The confluence-to-total PV ratio, length of drainage route, and anomalous PV return to the RA roof are important predictors for PPVS. Morphological subcategorization in this clinical setting can potentially assist in surgical decision-making.  相似文献   
5.
6.
7.
8.
Idiopathic myointimal hyperplasia of mesenteric veins (IMHMV) is a rare and poorly understood ischemic colitis that occurs in the rectosigmoid colon of predominantly young, previously healthy, male patients. A 76‐year‐old Japanese man presented to our hospital with a 1‐year history of worsening diarrhea, lower abdominal pain, and weight loss (−6 kg). Laboratory evaluation revealed white blood cell count of 13 200/μL, C‐reactive protein level of 2.0 mg/dL (normal range, 0.0–0.3), and negative results for stool culture (including Clostridium difficile). Colonoscopy showed circumferential and edematous narrowing of the sigmoid colon with deep longitude ulceration. Biopsy was done and examination of the specimen demonstrated no specific ischemia. The patient was treated with bowel rest, antibiotics, and i.v. fluids; however, his symptoms worsened. Finally, sigmoidectomy was carried out. Histological examination demonstrated significant myointimal hyperplasia of mesenteric veins leading to thickening and stenosis of the venous lumen. Therefore, the final diagnosis was IMHMV. Three months following sigmoidectomy, he was asymptomatic.  相似文献   
9.
10.
《Heart rhythm》2022,19(7):1104-1108
  1. Download : Download high-res image (116KB)
  2. Download : Download full-size image
  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