全文获取类型
收费全文 | 1512026篇 |
免费 | 106702篇 |
国内免费 | 2538篇 |
专业分类
耳鼻咽喉 | 20821篇 |
儿科学 | 44750篇 |
妇产科学 | 38186篇 |
基础医学 | 223941篇 |
口腔科学 | 44862篇 |
临床医学 | 134010篇 |
内科学 | 290911篇 |
皮肤病学 | 32750篇 |
神经病学 | 112866篇 |
特种医学 | 57543篇 |
外国民族医学 | 151篇 |
外科学 | 236427篇 |
综合类 | 31109篇 |
现状与发展 | 2篇 |
一般理论 | 382篇 |
预防医学 | 106144篇 |
眼科学 | 35277篇 |
药学 | 116669篇 |
4篇 | |
中国医学 | 4202篇 |
肿瘤学 | 90259篇 |
出版年
2018年 | 15453篇 |
2017年 | 12043篇 |
2016年 | 13409篇 |
2015年 | 15081篇 |
2014年 | 20610篇 |
2013年 | 30627篇 |
2012年 | 41203篇 |
2011年 | 43290篇 |
2010年 | 25615篇 |
2009年 | 24323篇 |
2008年 | 41359篇 |
2007年 | 43753篇 |
2006年 | 44924篇 |
2005年 | 42586篇 |
2004年 | 41343篇 |
2003年 | 39491篇 |
2002年 | 38680篇 |
2001年 | 81851篇 |
2000年 | 83997篇 |
1999年 | 69792篇 |
1998年 | 17188篇 |
1997年 | 14963篇 |
1996年 | 15263篇 |
1995年 | 14384篇 |
1994年 | 13301篇 |
1993年 | 12224篇 |
1992年 | 53292篇 |
1991年 | 51989篇 |
1990年 | 50221篇 |
1989年 | 49262篇 |
1988年 | 44765篇 |
1987年 | 43634篇 |
1986年 | 41066篇 |
1985年 | 39003篇 |
1984年 | 28191篇 |
1983年 | 23960篇 |
1982年 | 12768篇 |
1981年 | 11220篇 |
1979年 | 25398篇 |
1978年 | 17446篇 |
1977年 | 14884篇 |
1976年 | 13590篇 |
1975年 | 14925篇 |
1974年 | 17856篇 |
1973年 | 17014篇 |
1972年 | 16079篇 |
1971年 | 15112篇 |
1970年 | 14462篇 |
1969年 | 13478篇 |
1968年 | 12345篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
51.
M Bernasconi P N Chhajed F Gambazzi L Bubendorf H Rasch S Kneifel M Tamm 《The European respiratory journal》2006,27(5):889-894
There are no data available combining transbronchial needle aspiration (TBNA) of mediastinal lymph nodes and positron emission tomography (PET) in the staging of nonsmall cell lung cancer (NSCLC). The aim of the current study was to determine if these two methods can enhance the negative predictive value of the individual modality alone, for a specific lymph node station, and if this integrated approach can reduce the number of mediastinoscopies. A total of 113 patients with enlarged mediastinal lymph nodes (> or = 1 cm), who underwent both TBNA and PET scanning, were included. In 51 patients, histopathology, confirmed by surgical lymph node dissection, was compared with PET results and TBNA. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy to detect malignant lymphadenopathy was 68 (13/19), 89 (119/134), 46 (13/28), 95 (119/125) and 86% (132/152) for PET, respectively; 54% (6/11), 100 (53/53), 100 (6/6), 91 (53/58) and 92% (59/64), respectively for TBNA; and 100 (11/11), 94 (50/53), 79 (11/14), 100 (50/50) and 95 (61/64) for combined TBNA and PET, respectively. Combination of transbronchial needle aspiration and positron emission tomography has the potential to allow adequate mediastinal staging of nonsmall cell lung cancer with enlarged lymph nodes in most patients without the need for mediastinoscopy. 相似文献
52.
T. Svara M. Gombac M. Vrecl P. Juntes R. Kostanjsek A. Pogacnik M. Pogacnik 《Transboundary and Emerging Diseases》2006,53(1):26-29
Clinicopathological and electron microscopical findings of eight cases of enzootic nasal adenocarcinoma of sheep, diagnosed solely in one big flock in Slovenia between years 2001 and 2003 are described. All affected sheep were female, their mean age was 4.5 ± 1.5 years and they either belonged to the Istrian pramenka breed (five sheep) or were crossbreeds (three sheep). Tumours that arose from the ethmoid area of the nasal cavity were unilateral in six cases (75%) and bilateral in two cases (25%). All tumours were classified as adenocarcinomas by histopathological examination and they displayed either a combination of tubular and papillary growth or less often solely tubular proliferation. No metastases were detected in regional lymph nodes, brain or other organs. Electron microscopical studies performed on the reprocessed paraffin‐embedded tissues revealed the presence of the virus‐like particles with an average diameter between 70 and 90 nm. 相似文献
53.
54.
M Engelhardt P Bast N Jeblink W Lauer A Popovic H Eufinger M Scholz A Christmann A Harders K Radermacher K Schmieder 《Minimally invasive neurosurgery》2006,49(2):98-103
This study was performed to evaluate the surgical strategy in patients with calvarial tumours, in order to design and modify a robot-assisted trepanation system. A total of 75 patients underwent craniectomy for the treatment of calvarial tumours during the 10-year period from 1993 to 2002. The patients' complaints, the size, location and histology of the tumour, and the various cranioplasty techniques used were analysed retrospectively. In a second procedure several craniectomies at typical locations according to the study's results were performed in a laboratory setting using a hexapod robotic tool, constructed at the Helmholtz-Institute, RWTH Aachen University, and plastic model heads. The workflow was documented and the reproducibility and the accuracy of the procedure were registered. A total of 83 surgical procedures were performed on 75 patients. The majority (87 %) of lesions treated surgically were located in the frontal, temporal and anterior parts of the parietal region. Histological examination revealed benign lesions in 66 % of the patients and dural involvement in 46 %. According to these results craniectomies were performed using the robotic system. Mean positioning accuracy of the robotic system while milling was 0.24 mm, with a standard deviation of 0.04 mm, and maximum error under 1 mm. Craniectomies leaving a 1-mm layer of the tabula interna intact to ensure a healthy dura were performed in several regions successfully. The majority of calvarial tumours, requiring surgical treatment in our patients, were located in cosmetically relevant areas in which drilling can be carried out with the robotic trepanation system. Consequently, the surgical approach had to be planned carefully in order to achieve a good cosmetic outcome. 相似文献
55.
For many parents stopping life-sustaining medical treatment on their dying infant is psychologically impossible. Dostoevsky's insights into human behavior, particularly the fact that individuals do not want the anxiety and guilt associated with responsibility for making difficult decisions, might change the way physicians approach parents for permission to withdraw life-prolonging medical interventions on dying infants. 相似文献
56.
57.
58.
59.
60.