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   25905篇
  免费   1598篇
  国内免费   525篇
耳鼻咽喉   729篇
儿科学   375篇
妇产科学   70篇
基础医学   1543篇
口腔科学   1138篇
临床医学   2172篇
内科学   6960篇
皮肤病学   142篇
神经病学   294篇
特种医学   712篇
外国民族医学   3篇
外科学   8267篇
综合类   3123篇
现状与发展   2篇
预防医学   391篇
眼科学   705篇
药学   815篇
  9篇
中国医学   189篇
肿瘤学   389篇
  2024年   34篇
  2023年   558篇
  2022年   779篇
  2021年   1328篇
  2020年   1341篇
  2019年   1233篇
  2018年   1155篇
  2017年   792篇
  2016年   731篇
  2015年   836篇
  2014年   1660篇
  2013年   1659篇
  2012年   1257篇
  2011年   1419篇
  2010年   1115篇
  2009年   1115篇
  2008年   1100篇
  2007年   1160篇
  2006年   1105篇
  2005年   958篇
  2004年   811篇
  2003年   714篇
  2002年   640篇
  2001年   563篇
  2000年   517篇
  1999年   498篇
  1998年   388篇
  1997年   355篇
  1996年   295篇
  1995年   266篇
  1994年   250篇
  1993年   177篇
  1992年   171篇
  1991年   129篇
  1990年   128篇
  1989年   130篇
  1988年   94篇
  1987年   95篇
  1986年   94篇
  1985年   79篇
  1984年   72篇
  1983年   39篇
  1982年   46篇
  1981年   27篇
  1980年   36篇
  1979年   22篇
  1978年   13篇
  1977年   12篇
  1976年   12篇
  1973年   8篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
151.
目的了解再次冷冻保存对主动脉瓣膜细胞活性及组织结构的影响,探讨液氮冷冻保存的主动脉瓣解冻后再次冷冻保存使用的可行性.方法将猪主动脉瓣叶在抗菌处理后按随机数字表法分成三组,每组6个瓣叶,组Ⅰ作对照,组Ⅱ、组Ⅲ控制降温速率降至-80℃后在液氮中保存,1个月后融化解冻.组Ⅲ解冻并在室温下放置15分钟后更换保存液,再次降温至-80℃后放入液氮中保存,2个月后再融化解冻.采用XTT比色法测定各组瓣膜细胞活性,用免疫荧光组织化学染色、光学显微镜、透射电子显微镜行组织学检测.结果组Ⅱ冷冻保存后瓣膜细胞活性下降到组Ⅰ的63.97%,组织结构一定程度受损;组Ⅲ瓣膜细胞活性下降至组Ⅰ的38.60%,组织结构损害也进一步加重.结论液氮冷冻保存的猪主动脉瓣一经解冻融化,不宜再次冷冻保存使用.  相似文献   
152.
带血管蒂跗骨瓣移位术修复踝及足部骨病损   总被引:6,自引:2,他引:4  
目的 为治疗踝及足部骨质病损提供系列手术方式。方法 在解剖学研究基础上,设计了带血管蒂的骰骨瓣、内侧楔骨瓣、舟骨瓣和跟骨前外侧骨瓣移位术,以修复踝及足骨质病损。临床应用55例。结果 术后经l—10年随访48例,平均为4年6个月,疗效满意。结论 上述4种跗骨瓣均具有血管蒂位置表浅、解剖容易和手术安全可靠等优点。  相似文献   
153.
目的 探讨抗菌处理对肺动脉瓣膜细胞活性和组织结构的影响因素及优化同种瓣膜的制备方法。方法 3组猪肺动脉瓣叶(n=6)浸泡在含抗生素的DMEM液中,在不同温度下孵育6h或24h。然后通过XTT比色法测定瓣膜细胞活性,用免疫组织化学荧光染色检测瓣膜细胞和细胞外基质,并行光镜观察。结果 抗菌时间为24h,37℃抗菌组与4℃抗菌组的瓣膜细胞活性与瓣膜组织结构无明显区别。抗菌6h组的瓣膜细胞活性与瓣膜组织结构明显优于抗菌24h组。结论 抗菌时间为24h时,抗菌温度对瓣膜细胞活性及结构完整性无明显影响。抗菌时间缩短至6h,有利于瓣膜细胞活性与结构完整性的保持。  相似文献   
154.
Acute aortic dissection complicated with acute myocardial infarction (AMI) is the most fatal situation. We experienced the successful treatment for acute type A aortic dissection complicated with inferior AMI following aortic valve replacement (AVR). A 60-year-old man had had AVR for aortic regurgitation. Sixteen months after the AVR, he had a sudden onset of severe chest pain with complete atrioventricular block. Immediately, temporary pacing and cardiac catheterization were conducted, showing the occlusion of the right coronary artery due to acute type A aortic dissection. On his way to our hospital, direct current shock was conducted 3 times for ventricular fibrillation. We replaced the ascending aorta combined with coronary artery bypass grafting and the postoperative course was uneventful. The key to treat acute aortic dissection complicated with AMI is early accurate diagnosis, prompt temporary pacing for bradycardia, defibrillation for lethal arrhythmia and insertion of a perfusion catheter if possible. These preoperative hemodynamic stabilization gives us the chance to save these patients.  相似文献   
155.
心脏瓣膜置换术后中远期疗效分析   总被引:8,自引:0,他引:8  
目的 分析探讨心脏瓣膜置换术的中远期疗效。方法  1978年至 2 0 0 1年 12月 ,行瓣膜置换手术 2 14 1例 ,同期随访 16 81例 ,计 80 2 1 1人·年 ,平均 4 77人·年。通过回顾病因、手术方式、瓣膜类型等因素 ,观察术后病人心功能改善情况 ,病死率及并发症等 ,采用t检验 ,多因素回归等统计学方法分析。结果  92例死亡。总体生存率 5年为 (92 3± 2 2 ) % ,10年生存率为 (90 1± 2 7) %。并发症有血栓栓塞、机械瓣膜功能障碍、瓣周漏、溶血、机械瓣膜感染性心内膜炎。术后心功能 (NYHA)与术前比较有明显的提高。结论  1.机械瓣置换术后中远期疗效满意 ,病死率及并发症均较低 ;与术前心功能和手术种类直接相关 ;2 .使用保留瓣下结构及三尖瓣成形术对术后心功能恢复有明显效果 ;3.术中良好心肌保护是提高手术成功率的关键。  相似文献   
156.
We report on a case of esophageal atresia following cervical spine surgery. A swallowing examination was performed using fibre-optic endoscopy and videofluoroscopy. There was scar tissue fixation of the larynx and esophagus to the cervical spine. Operative mobilization of the larynx and esophagus and formation of a sliding layer using a platysma-fascia flap was done. The PEG and tracheal cannula were removed; oral nutrition was initiated after 3 months. Swallowing disorders following operations on the upper cervical spine should be investigated. Careful preparation that preserves the layers should be carried out. Fixation of tissues as a result of scarring should be treated with a sliding layer.  相似文献   
157.
Twenty-two percutaneous transluminal balloon valvuloplasty procedures were performed on 21 patients with congenital pulmonary valve stenosis. The peak systolic pressure gradient was immediately reduced from 79.1 +/- 7.4 to 22.2 +/- 1.8 mmHg, (P less than 0.0001) and follow-up cardiac catheterization at 5.3 +/- 0.4 months in 19 patients revealed no further significant change in gradient (23.5 +/- 3.2 mmHg). The best results were obtained when balloons larger than the pulmonary annulus were used, i.e. an immediate residual transvalvular gradient of 22.0 +/- 2.2 mmHg with a balloon/annulus ratio greater than 1, as opposed to 44.2 +/- 5.4 with a balloon/annulus ratio = 1 (P less than 0.001). The angiographically determined cusp thickness of the stenotic pulmonary valves was significantly greater than that of the control group of 24 patients without pulmonary valve stenosis (1.21 +/- 0.09 vs 0.59 +/- 0.02 mmHg, P less than 0.00001). The relationship between this parameter and the residual transvalvular gradient at follow-up was found to be significant (r = 0.77, P less than 0.001). It is concluded that balloon size is a determinant factor in achieving good results with percutaneous balloon valvuloplasty although cusp thickness, a factor to which scant regard has hitherto been paid, also plays a significant role in the residual transvalvular gradient measured at follow-up.  相似文献   
158.
We used inferior pedicled composite multi-fractured osteoperiosteal flap (CMOF), our original and new surgical approach, to obliterate the mastoid cavity and reconstruct the external auditory canal (EAC) to prevent the open cavity problems. CMOF was used to obliterate the mastoid cavity and reconstruct the EAC in 24 patients (13 women, 11 men; age span 12–51 years) who underwent radical mastoidectomy to treat the chronic otitis media between 1998 and 2004. Small meatoplasty was done in all 24 patients to relive their aesthetical concerns. Temporal bone CT scanning was done to observe the neo-osteogenesis in the mastoidectomy cavity and the CMOF, and the EAC volume was measured postoperatively. All our patients were followed-up for 2 years. The epithelization of the new EAC in our patients was complete at the end of the second month. Cholesteatoma, granulation, and recurrence of osteitis did not occur in any of the patients. We saw the new bone formation filling the mastoid cavity in the postoperative temporal bone CT scanning images. The mean volume of the new EAC on the 24th month was 1.83 ± 0.56 cm3. We had an almost natural EAC, which owed its existence to the neo-osteogenesis that grows behind the CMOF, which we use to obliterate the mastoid cavity and to reconstruct the EAC.This technique, composite multi-fractured osteoperiosteal flap, was presented in the symposium of Gulhane Military Medical Academy on otology and audiology, 15–18 September, 2005, Antalya, Turkey.  相似文献   
159.
Summary The rectus abdommis myocutaneous flap, based on the deep inferior epigastric vessels, is an excellent flap for reconstructing large wounds of the groin and perineum. However, wound infection in the donor site is a potential complication, even with thorough preparation of the recipient site. We present one such case in a diabetic patient who developed a necrotizing fasciitis and evisceration following transfer of an inferiorly based myocutaneous flap.  相似文献   
160.
Foropenseverewoundandthewoundafterdebridement,mostscholarsthinkthewoundshouldbeclosedindelayedfirst-phase.Meshrelaxingshortincision(MRSI)methodcanclosemoreskindeficiencyandhightensionopenwound,andavoidsubcutaneoushematomaandskinflapdrift.Intheexperiment,theexperimentalmodelonrattensionskinflaphasbeeninvolved,andthecontentofendothelin(ET)inratskinflaptissuehasbeenmeasuredinvariousperiodofwoundhealingaftermeshedrelaxingshortincisionsuturewithimmunohistochemistry,inordertodiscussprobablemechani…  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