全文获取类型
收费全文 | 246004篇 |
免费 | 36778篇 |
国内免费 | 3145篇 |
专业分类
耳鼻咽喉 | 6219篇 |
儿科学 | 8229篇 |
妇产科学 | 4796篇 |
基础医学 | 16253篇 |
口腔科学 | 3595篇 |
临床医学 | 34223篇 |
内科学 | 68025篇 |
皮肤病学 | 9509篇 |
神经病学 | 23460篇 |
特种医学 | 10073篇 |
外国民族医学 | 23篇 |
外科学 | 53787篇 |
综合类 | 1881篇 |
现状与发展 | 72篇 |
一般理论 | 47篇 |
预防医学 | 12590篇 |
眼科学 | 4838篇 |
药学 | 8922篇 |
3篇 | |
中国医学 | 520篇 |
肿瘤学 | 18862篇 |
出版年
2024年 | 721篇 |
2023年 | 5126篇 |
2022年 | 2201篇 |
2021年 | 4841篇 |
2020年 | 7104篇 |
2019年 | 3782篇 |
2018年 | 9298篇 |
2017年 | 8794篇 |
2016年 | 9977篇 |
2015年 | 10262篇 |
2014年 | 17863篇 |
2013年 | 19186篇 |
2012年 | 10450篇 |
2011年 | 10631篇 |
2010年 | 13540篇 |
2009年 | 17000篇 |
2008年 | 10286篇 |
2007年 | 8734篇 |
2006年 | 10984篇 |
2005年 | 8120篇 |
2004年 | 7687篇 |
2003年 | 6509篇 |
2002年 | 6600篇 |
2001年 | 7473篇 |
2000年 | 6632篇 |
1999年 | 6141篇 |
1998年 | 4763篇 |
1997年 | 4333篇 |
1996年 | 4158篇 |
1995年 | 3979篇 |
1994年 | 2615篇 |
1993年 | 2221篇 |
1992年 | 3128篇 |
1991年 | 3143篇 |
1990年 | 2532篇 |
1989年 | 2598篇 |
1988年 | 2314篇 |
1987年 | 2018篇 |
1986年 | 2035篇 |
1985年 | 1737篇 |
1984年 | 1299篇 |
1983年 | 1204篇 |
1982年 | 953篇 |
1981年 | 780篇 |
1980年 | 707篇 |
1979年 | 872篇 |
1978年 | 744篇 |
1977年 | 765篇 |
1975年 | 708篇 |
1972年 | 722篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
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
85.
86.
Salwa AlDahlawi BDS MSc ; Ameneh Eslami MD ; Lari Häkkinen DDS PhD ; Hannu S. Larjava DDS PhD 《Wound repair and regeneration》2006,14(3):289-297
The alphavbeta6 integrin is an exclusively epithelial integrin that is highly expressed during fetal development. In adult tissue, alphavbeta6 integrin is expressed during inflammation, carcinogenesis, and in wound healing. We previously reported that alphavbeta6 integrin is highly expressed in poorly healing human wounds and its over-expression is associated with chronic wounds in a mouse model. The objective of this study was to investigate the role of alphavbeta6 integrin in compromised wound healing induced by hydrocortisone treatment or aging by using young and old mice deficient in or overexpressing the beta6 integrin subunit in the epidermis. Untreated aged beta6 integrin-deficient (beta6-/-) animals showed a significant delay in wound healing when compared to their age-matched controls or younger beta6-/- mice. The most significant delay was observed at the stages where granulation tissue deposition was occurring. Hydrocortisone treatment significantly delayed wound healing in wild-type and beta6 integrin-deficient mice in comparison with the untreated controls. However, hydrocortisone treatment in beta6 integrin overexpressing animals did not cause a significant delay in wound healing. The results of this study suggest that alphavbeta6 integrin plays an important role in wound healing in animals compromised by either age or stress mimicked by hydrocortisone. 相似文献
87.
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
88.
TOBIAS HUND MD BENJAMIN ASCHER MD BERTHOLD RZANY MD SCM FOR THE SMILE STUDY GROUP 《Dermatologic surgery》2006,32(10):1256-1260
BACKGROUND: Several clinical scoring systems have been used to evaluate the efficacy of botulinum toxin A in the treatment of hyperkinetic wrinkles. So far very few have been investigated for their reproducibility. OBJECTIVE: The aim of this study was to investigate the reproducibility of two clinical four-point scales for lateral canthal lines (crow's feet), at rest and at maximum smile. MATERIAL AND METHODS: Based on standardized photographs, a consensus atlas depicting the different severity grades [from 0 (none) to 3 (severe)] was developed. After training based on the atlas, 49 photographs at rest and 48 at maximum smile were graded by the same group of investigators on 2 consecutive days (n=9 on Day 1; n=8 on Day 2). The scores were compared for reproducibility using kappa statistics. RESULTS: Overall, reproducibility was good for both scales. Interobserver reproducibility showed an agreement of 0.6 at rest and 0.58 at maximum smile (unweighted kappa). Intraobserver reproducibility showed an agreement between 0.47 and 0.86 at rest and between 0.62 and 0.81 at maximum smile (unweighted kappa). Using weighted kappa analysis, the agreement ranged between 0.63 and 0.91 at rest and between 0.71 and 0.85 at maximum smile. CONCLUSION: The clinical scales using scores of 0 to 3 for crow's feet, both at rest and at maximum smile, show a good inter- and intraobserver reproducibility. The use of these scores in clinical trials can be recommended. 相似文献
89.
90.