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   11669篇
  免费   795篇
  国内免费   64篇
耳鼻咽喉   69篇
儿科学   162篇
妇产科学   158篇
基础医学   1493篇
口腔科学   206篇
临床医学   1057篇
内科学   2620篇
皮肤病学   306篇
神经病学   1207篇
特种医学   690篇
外科学   2217篇
综合类   48篇
一般理论   2篇
预防医学   514篇
眼科学   87篇
药学   554篇
中国医学   31篇
肿瘤学   1107篇
  2023年   82篇
  2022年   115篇
  2021年   312篇
  2020年   184篇
  2019年   270篇
  2018年   337篇
  2017年   272篇
  2016年   302篇
  2015年   325篇
  2014年   435篇
  2013年   544篇
  2012年   841篇
  2011年   909篇
  2010年   554篇
  2009年   485篇
  2008年   736篇
  2007年   728篇
  2006年   733篇
  2005年   751篇
  2004年   661篇
  2003年   629篇
  2002年   575篇
  2001年   129篇
  2000年   116篇
  1999年   141篇
  1998年   144篇
  1997年   120篇
  1996年   79篇
  1995年   74篇
  1994年   52篇
  1993年   36篇
  1992年   60篇
  1991年   54篇
  1990年   48篇
  1989年   58篇
  1988年   48篇
  1987年   57篇
  1986年   53篇
  1985年   31篇
  1984年   48篇
  1983年   34篇
  1982年   21篇
  1981年   23篇
  1980年   24篇
  1979年   27篇
  1978年   24篇
  1977年   16篇
  1976年   19篇
  1975年   15篇
  1974年   20篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
22.
目的 探讨股骨假体周骨折不同处理方法的临床应用价值。方法 对16例股骨假体周骨折分别采用钢丝、钢板螺钉、环抱器固定和更换长柄假体植入方法处理.总结分析其相关临床资料。结果 16例病人术后随访4~14个月.平均6个月,全部病例骨折愈合,功能恢复良好。髋关节功能评定:90分以上3例、80~89分9例、70-79分3例、63分1例,优良率达75%。结论 股骨假体周骨折类型不同,处理方法应不同:股骨颈端到小粗隆下缘的劈裂骨折,采用钢丝捆扎;全劈裂骨折移位明显,更换较小型号的假体,再用钢丝捆扎固定并植骨;小粗隆下缘到股骨干髓腔狭窄段的上缘骨折,选用长柄假体植入再用钢丝捆扎,假体远端加锁固定或选用环抱器固定;股骨干髓腔狭窄段以下的骨折,采用钢板固定或环抱器固定并植骨。  相似文献   
23.
Abstract: In order to evaluate the level of evidence of factors influencing the survival of reconstructions, systematic reviews of the relevant literature were prepared by a group of rapporteurs. The review papers were circulated to the members of the group before the conference and formed the basis for group and panel discussions. Subsequently, modifications were added to the review papers, and suggestions for consensus statements concerning the following topics were prepared and again critically reviewed in the group and in the plenum: Impact of (i) periodontal disease on the survival of tooth-supported reconstructions, (ii) post-surgical factors as supportive therapy on the survival of implant supported reconstructions, (iii) technical and/or biological complications on the survival of different types of reconstructions, (iiii) material choice for reconstructions on the survival of single crowns and fixed dental prostheses.  相似文献   
24.
Namensgebend für das Jo-1-Syndrom sind Autoantikörper gegen das Jo-1-Antigen, die bei diesem Krankheitsbild im Serum der betroffenen Patienten nachgewiesen werden. Der Name Jo-1 leitet sich von dem ersten Patienten (John P.) ab, bei dem diese Antikörper gefunden wurden. Dieser Patient litt an einer Polymyositis und fibrosierenden Alveolitis. Das Jo-1-Antigen ist identisch mit der Histidyl-Transfer-RNA-Synthetase im Zytosol. Das Jo-1-Syndrom gehört zu einer Familie von Autoimmunerkrankungen, die als Anti-Synthetase- Syndrome bezeichnet werden. Diese Syndrome haben gemeinsam, dass jeweils Autoantikörper gegen unterschiedliche Aminosäure-Transfer-RNASynthetasen nachweisbar sind. Klinisch handelt es sich beim Jo-1-Syndrom um eine Sonderform der Poly- bzw. Dermatomyositis von bisher ungeklärter Ätiologie. Neben einer Muskelbeteiligung kommt es charakteristischerweise zu einer interstitiellen Lungenbeteiligung, die auch prognostisch das Krankheitsbild bestimmt. Zusätzlich können klinisch eine Polyarthritis und weitere Symptome bestehen, die dem klinischen Bild anderer Kollagenosen ähneln. Ebenso wie die Polymyositis und Dermatomyositis kann sich das Jo-1-Syndrom in sog. Myositis-Overlap-Syndromen präsentieren. Zu dieser Diagnose führt ein Symptomenkomplex, der die klare Zuordnung zu einer einzelnen Erkrankung nicht möglich macht. Häufig werden in solchen Fällen U1-RNP-Antikörper nachgewiesen. Therapeutisch spricht das Jo-1-Syndrom auf die Gabe von Kortikosteroiden und—falls notwendig—Azathioprin, Methotrexat und Cyclophosphamid an. Eine Kurzbeschreibung von zwei klinischen Fällen stellt das Krankheitsbild anschaulich dar.  相似文献   
25.
The combination of small-animal PET and MRI data provides quantitative in vivo insights into cardiac pathophysiology, integrating information on biology and morphology. We sought to determine the feasibility of PET and MRI for the quantification of ischemic injury in the rat model. METHODS: Fourteen healthy male Wistar rats were studied with 18F-FDG PET and cine MRI. Myocardial viability was determined in a transmural myocardial infarction model in 12 additional rats, using 18F-FDG PET and delayed-enhancement MRI with gadolinium-diethylenetriaminepentaacetic acid. All PET was acquired with a dedicated small-animal PET system. MRI was performed on a 1.5-T clinical tomograph with a dedicated small-animal electrocardiographic triggering device and a small surface coil. RESULTS: In normal rats, 18F-FDG uptake was homogeneous throughout the left ventricle. The lowest mean uptake of the 18F-FDG was found in the apical regions (79% +/- 6.0% of maximum) and the highest uptake was in the anterior wall (93% +/- 4.3 % of maximum). Myocardial infarct size as determined by histology correlated well with defects of glucose metabolism obtained with 18F-FDG PET (r = 0.89) and also with delayed-enhancement MRI (r = 0.91). Left ventricular ejection fraction in normal rats measured by cine MRI was 57% +/- 5.4% and decreased to 38% +/- 12.9% (P < 0.001) in the myocardial infarction model. CONCLUSION: Integrating information from small-animal PET and clinical MRI instrumentation allows for the quantitative assessment of cardiac function and infarct size in the rat model. The MRI measurements of scar can be complemented by metabolic imaging, addressing the extent and severity of ischemic injury and providing endpoints for therapeutic interventions.  相似文献   
26.
OBJECTIVE: The 'frozen' elephant trunk technique allows for single-stage repair of combined aortic arch and descending aortic aneurysms using a 'hybridprosthesis' with a stented and a non-stented end. This report summarizes the operative- and follow-up data (mean follow-up 14 months) with this new treatment. METHODS: Between 09/01 and 4/04, 22 patients (62+/-9 years; 9 female) with different aortic pathologies (15 aortic dissections, 7 aneurysms) were operated on after approval from the local institutional review board. The stented end of the hybridprosthesis was deployed in the descending aorta through the opened aortic arch during hypothermic circulatory arrest and selective antegrade cerebral perfusion. RESULTS: All patients survived the procedure but one patient died of acute hemorrhage due to rupture of the false lumen in the descending aorta on the second postoperative day. Two patients required reexploration of the chest for bleeding complications. In 2 of 4 patients who developed neurological dysfunction, symptoms resolved completely. In one of them, the descending aorta was perforated intraoperatively due to misplacement of the stented end of the hybridprosthesis. In all follow-up CT-scans thrombus formation in the descending aortic aneurysm excluded by the stented end of the hybridprosthesis has been observed. CONCLUSIONS: This procedure is performed through median sternotomy and combines the concepts of the elephant trunk operation and endovascular stenting of descending aortic aneurysms. Favourable intraoperative and postoperative results during follow-up with regard to thrombus formation around the stented descending aortic segment encourage us to evaluate all patients with thoracic aneurysms extending to proximal and distal of the left subclavian artery for this treatment.  相似文献   
27.
Joint cartilage functions as a barrier against the extension of bone tumors. However, transarticular invasion by iliopelvic sarcomas across the sacroiliac (SI) joints into the sacrum sometimes occurs. We made a radiological analysis (CT and/or MRI) of 47 bone sarcomas which originated in the ilium and extended nearly to the SI joint. 8 of 17 chondrosarcomas and 3 of 30 other sarcomas (2 of 23 Ewing's sarcomas and 1 of 7 osteosarcomas) invaded the sacrum through the SI joint.  相似文献   
28.
We reviewed the treatment outcome of 69 patients with Ewing's sarcoma of the femur. The patients received chemotherapy according to the CESS 81 (n 14), CESS 86 (n 43), and CESS 91P (n 12) protocols. The 10-year relapse-free survival rates were 36%, 65%, and 65% (p = 0.01). 68 patients received local treatment. The primary tumor was treated by surgery without radiotherapy in 28 patients; 1 developed a local recurrence and 7 metastases. 10 patients received radiotherapy alone; 4 developed metastases and 4 local recurrences and metastases. 30 cases had a combination of surgery and radiotherapy; 7 developed metastases and 1 a local recurrence and metastasis. The survival of patients after radiotherapy alone was worse than that of patients after surgery with/without radiotherapy (p = 0.005). Pathological fractures (n 16) did not influence the prognosis.  相似文献   
29.
Zusammenfassung Operationsziel Schmerzfrei belastungsf?hige Fü?e. Indikationen Gehen und Stehen schmerzhaft. Unbefriedigende Einlagen- und Schuhversorgung. Unbefriedigende ?sthetik. Kontraindikationen Schlechte Hautverh?ltnisse. Operationstechnik Dorsaler Zugang beiderseits. Resektion von intermetatarsalen Knochenbrücken. Korrekturosteotomien fehlstehender Mittelfu?knochen. Beseitigung des Hallux varus durch Reposition der Gro?zehe im Grundgelenk und tempor?re Kirschner-Drahtfixation des Gro?zehenstrahls und der Mittelfu?fragmente. Ergebnisse Zw?lf Jahre nach den Eingriffen an beiden Fü?en lag ein ?sthetisch und funktionell sehr gutes Resultat vor. Die Patientin trug normale Kaufschuhe und belastete beide Fü?e tadellos. Die Fü?e konnten allerdings wegen ausgedehnter angeborener Synostosen der Fu?wurzel- und Tarsometatarsalgelenke nicht befriedigend abgerollt werden.  相似文献   
30.
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