全文获取类型
收费全文 | 1979篇 |
免费 | 161篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 102篇 |
妇产科学 | 22篇 |
基础医学 | 231篇 |
口腔科学 | 43篇 |
临床医学 | 278篇 |
内科学 | 310篇 |
皮肤病学 | 16篇 |
神经病学 | 81篇 |
特种医学 | 210篇 |
外科学 | 368篇 |
综合类 | 43篇 |
预防医学 | 180篇 |
眼科学 | 16篇 |
药学 | 118篇 |
肿瘤学 | 134篇 |
出版年
2023年 | 10篇 |
2021年 | 24篇 |
2020年 | 11篇 |
2019年 | 27篇 |
2018年 | 30篇 |
2017年 | 23篇 |
2016年 | 26篇 |
2015年 | 33篇 |
2014年 | 58篇 |
2013年 | 63篇 |
2012年 | 74篇 |
2011年 | 63篇 |
2010年 | 65篇 |
2009年 | 73篇 |
2008年 | 70篇 |
2007年 | 83篇 |
2006年 | 61篇 |
2005年 | 53篇 |
2004年 | 59篇 |
2003年 | 67篇 |
2002年 | 63篇 |
2001年 | 62篇 |
2000年 | 61篇 |
1999年 | 58篇 |
1998年 | 54篇 |
1997年 | 51篇 |
1996年 | 45篇 |
1995年 | 45篇 |
1994年 | 39篇 |
1993年 | 39篇 |
1992年 | 39篇 |
1991年 | 45篇 |
1990年 | 38篇 |
1989年 | 56篇 |
1988年 | 54篇 |
1987年 | 38篇 |
1986年 | 46篇 |
1985年 | 41篇 |
1984年 | 43篇 |
1983年 | 37篇 |
1982年 | 38篇 |
1981年 | 18篇 |
1980年 | 25篇 |
1979年 | 16篇 |
1978年 | 16篇 |
1977年 | 15篇 |
1976年 | 15篇 |
1975年 | 9篇 |
1970年 | 8篇 |
1937年 | 7篇 |
排序方式: 共有2160条查询结果,搜索用时 281 毫秒
1.
2.
3.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
4.
Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence. 相似文献
5.
6.
7.
Huang Guo-Shu MD Chang Wei-Chou MD Lee Herng-Sheng MD † Taylor John A. M. DC DACBR ‡ Cheng Tiang-Yeu MD § Chen Cheng-Yu MD 《Dermatologic surgery》2005,31(6):717-719
BACKGROUND: Merkel cell carcinoma is a rare malignant neuroendocrine neoplasm characteristically arising from the dermis of sunlight-exposed skin. It rarely arises outside the skin. OBJECTIVE: We present a patient with primary Merkel cell carcinoma arising from subcutaneous fat, with no involvement of the overlying skin. We describe the clinical manifestations and magnetic resonance imaging (MRI) findings. METHODS: We report a 63-year-old woman with a primary lesion of Merkel cell carcinoma that arose from the subcutaneous fat layer of the left arm. The lesion presented as a subcutaneous nodule with intact overlying skin. MRI showed that the nodular lesion was located entirely in the subcutaneous fat layer, with no involvement of the dermis. Peritumoral infiltration around the lesion and enlarged lymph nodes deep to the lesion were noted. The patient received wide excision of the lesion with dissection of the regional lymph nodes and adjuvant radiotherapy and chemotherapy. RESULTS: Histopathologic examination confirmed the diagnosis of Merkel cell carcinoma with local lymphatic metastasis, and the lesion was completely located in the subcutaneous fat, with no involvement of the dermis. These findings were well correlated with MRI findings. CONCLUSION: Primary Merkel cell carcinoma may arise from the subcutaneous fat and present as an entirely subcutaneous lesion with intact skin. MRI is helpful to evaluate the local extension of the lesion and regional lymphatic metastasis. 相似文献
8.
表小檗碱对α受体的作用 总被引:2,自引:0,他引:2
表小檗碱(epiberberine,EB)是从湖北产黄连(Coptis chinensis Franch)中提取的一种生物碱,属苯喹嗪类原小檗碱,对其药理作用的研究资料甚少,未见其对α肾上腺素体作用的报道。资料表明,许多原小檗碱类化合物有α受体阻滞作用,为从该类化合物中选择 相似文献
9.
Wolfgang Lutz Michael J. Lambert S. Cory Harmon Armita Tschitsaz Eva Schürch Niklaus Stulz 《Clinical psychology & psychotherapy》2006,13(4):223-232
Empirical methods have been found to be superior to clinical judgment for the purpose of correctly identifying patients at risk for treatment failure and, hence, to enhance psychotherapy outcomes. The development and evaluation of an empirical approach aimed at supporting clinical decisions during the course of psychotherapy is described. The tool provides predictions based on a patient‐specific sampling strategy called the nearest neighbors method and on growth curve approaches to model an expected treatment course for each patient. Using session‐by‐session data from an outpatient center in the US (N = 4365), this new empirically derived decision model was evaluated and compared with a clinically based approach loosely based on an adaptation of clinically significant change concepts. The empirically derived decision system was found to be superior to the rational clinically based one in almost all measures of prediction accuracy, indicating its potential to identify patients at risk for treatment failure. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
10.
Valves in the subclavian and internal jugular veins were studied in 100 autopsy cases (52 men and 48 women; range, 18 to 91 years old; mean, 67 years). In 87 cases, valves were present in all 4 veins, and in 13 cases, valves anatomically were absent from 16 veins, 9 of which were the left internal jugular vein. The average distance from the valve to the junction with the innominate vein was 1.7 cm for the subclavian vein and 0.3 cm for the internal jugular vein. Cuspid height averaged 0.9 cm. Valves were bicuspid in 347 (90%) and unicuspid in 39 (10%); unicuspid valves were more common in the internal jugular vein than in the subclavian vein. Catheter-induced trauma was observed in 4 cases and implied in 4 more. These findings may have important implications concerning the failure, in some cases, of closed-chest cardiac resuscitation to maintain forward blood flow at adequate pressure. 相似文献