全文获取类型
收费全文 | 148235篇 |
免费 | 9766篇 |
国内免费 | 846篇 |
专业分类
耳鼻咽喉 | 1758篇 |
儿科学 | 4346篇 |
妇产科学 | 3711篇 |
基础医学 | 21599篇 |
口腔科学 | 3581篇 |
临床医学 | 12795篇 |
内科学 | 31292篇 |
皮肤病学 | 2766篇 |
神经病学 | 13792篇 |
特种医学 | 5865篇 |
外国民族医学 | 66篇 |
外科学 | 20172篇 |
综合类 | 2171篇 |
一般理论 | 121篇 |
预防医学 | 9861篇 |
眼科学 | 2560篇 |
药学 | 11588篇 |
3篇 | |
中国医学 | 655篇 |
肿瘤学 | 10145篇 |
出版年
2022年 | 1333篇 |
2021年 | 2580篇 |
2020年 | 1647篇 |
2019年 | 2355篇 |
2018年 | 2899篇 |
2017年 | 2154篇 |
2016年 | 2339篇 |
2015年 | 2742篇 |
2014年 | 3553篇 |
2013年 | 5515篇 |
2012年 | 7242篇 |
2011年 | 7481篇 |
2010年 | 5089篇 |
2009年 | 4401篇 |
2008年 | 6678篇 |
2007年 | 7017篇 |
2006年 | 6811篇 |
2005年 | 6472篇 |
2004年 | 6849篇 |
2003年 | 6507篇 |
2002年 | 6580篇 |
2001年 | 5497篇 |
2000年 | 5527篇 |
1999年 | 4651篇 |
1998年 | 1867篇 |
1997年 | 1519篇 |
1996年 | 1360篇 |
1995年 | 1362篇 |
1994年 | 1176篇 |
1993年 | 1175篇 |
1992年 | 3056篇 |
1991年 | 2952篇 |
1990年 | 2682篇 |
1989年 | 2624篇 |
1988年 | 2287篇 |
1987年 | 2180篇 |
1986年 | 2116篇 |
1985年 | 1910篇 |
1984年 | 1389篇 |
1983年 | 1289篇 |
1982年 | 850篇 |
1981年 | 781篇 |
1980年 | 695篇 |
1979年 | 1142篇 |
1978年 | 755篇 |
1977年 | 697篇 |
1975年 | 779篇 |
1974年 | 874篇 |
1973年 | 787篇 |
1972年 | 736篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
W De Wever Y Vankan S Stroobants J Verschakelen 《The European respiratory journal》2007,29(5):995-1002
The aim of the present study was to assess retrospectively the additional value of positron emission tomography (PET)/computed tomography (CT) in the detection of unexpected extrapulmonary lesions in the staging of patients with a malignant pulmonary lesion in comparison with CT and PET used alone. A total of 217 patients with a pathologically proven lung tumour underwent PET/CT. CT, PET and PET/CT were evaluated in the detection of extrapulmonary lesions. These abnormalities were compared with the final diagnosis obtained from the medical records and statistical analysis was carried out. In total, 108 lesions were clinically detected. PET/CT showed a sensitivity, specificity, positive and negative predictive values and accuracy of 100, 81, 71, 100 and 87%, respectively, for the detection of extrapulmonary lesions and 92, 98, 89, 98 and 97%, respectively, for the detection of malignant extrapulmonary lesions. PET/CT was significantly better than CT and PET used alone. Conventional staging work-up has a poor sensitivity in detecting second primary cancers or unexpected metastases. The detection of malignant extrapulmonary lesions is necessary for correct tumour staging. By combining both metabolic and anatomical information, positron emission tomography/computed tomography is able to depict more unexpected extrapulmonary lesions than computed tomography and positron emission tomography used alone, and positron emission tomography/computed tomography provides more additional information of malignancy or benignancy of lesions detected with one of the two imaging modalities alone. 相似文献
43.
E Gadelha Figueiredo M Castillo De la Cruz N Theodore P Deshmukh M C Preul 《Minimally invasive neurosurgery》2006,49(1):37-42
We describe a modified keyhole laminoforaminotomy (LF) using anatomic landmarks on the posterior aspect of the cervical vertebral body to decompress the intervertebral foramen with minimal bone removal. Twenty-four procedures were performed at C3-4, C4-5, and C5-6; 12 at C6-7; and 3 at C7-Tl. Facets and laminae structures were identified based on relative surgical perspectives. Bony resection was limited as follows: 1) inferior limit; inferior border of the superior facet; 2) superior limit, superior border of the superior facet; 3) lateral limit, a vertical line linking the junction of the lamina-facet to the lateral end of the superior limit; and 4) lateral aspect of the dural sac. Fluoroscopy was used to confirm that the intervertebral space was reached. The amount of bony removal was quantified for the superior and inferior laminae and facets. The length of the exposed nerve root was measured. The intervertebral foramen was exposed and the intervertebral disc reached in all specimens. Fluoroscopy showed that the center of the exposure remained at the same height with the intervertebral space. The mean length of the nerve root was 4.6 mm; the mean percentage of bony resection was 21.8%, 7.5%, 11.3%, and 11.5% for the superior and inferior laminae and facets, respectively. Opening the intervertebral foramen posteriorly consistently exposed sufficient nerve root length and allowed access to the intervertebral disc. The technique offers the most direct and safest method of decompressing the intervertebral foramen while minimizing bony resection. This simple surgical procedure may help reduce postoperative morbidity. 相似文献
44.
Factors affecting aseptic loosening of 4750 total hip arthroplasties: multivariate survival analysis
Barbara Bordini Susanna Stea Manuela De Clerico Sergio Strazzari Antonio Sasdelli Aldo Toni 《BMC musculoskeletal disorders》2007,8(1):69
Background
Total hip arthroplasty is a successful surgery, that fails at a rate of approximately 10% at ten years from surgery. Causes for failure are mainly aseptic loosening of one or both components partially due to wear of articular surfaces and partially to design. The present analysis aimed to identify risk factors and quantify their effects on aseptic failure. 相似文献45.
A survey was performed on the radiotherapy practice of malignant pleural mesothelioma in The Netherlands and Belgium in 2002. Thirty-eight out of 47 centres (81%) responded. Prophylactic radiotherapy to intervention sites is given by 32/38 (84%) centres, with all centres offering palliative radiation. For both prophylactic and palliative indications, all centres use hypo-fractionated schedules. The present study shows that in the radiotherapy community in The Netherlands and in Belgium, a de facto consensus exists that both prophylactic and symptomatic radiotherapy to intervention sites of malignant pleural mesothelioma are effective and that hypo-fractionated schedules should be used. 相似文献
46.
47.
48.
49.
The effect of diaper type and overclothing on fecal contamination in day-care centers 总被引:2,自引:0,他引:2
Fecal coliform contamination of environmental surfaces and hands in the day-care center is common. This study evaluated the effect of two diaper types on fecal contamination. Ten rooms in four day-care centers containing 141 children were studied in a prospective, randomized, crossover study. A total of 2946 samples were cultured during the 9-week study. Fecal coliforms were isolated from 307 inanimate objects (15%), 73 toy balls (46%), and 131 hands (17%). The number of contaminated inanimate objects was significantly less in rooms where paper diapers were worn when compared with that in rooms where double cloth diapers with plastic overpants were worn and in rooms where clothes were worn over diapers. Inanimate object cultures had more contamination in rooms in which diarrhea had occurred. Containment of feces by overclothes and diaper type may be important in decreasing transmission of enteric pathogens in day-care environments. 相似文献
50.