全文获取类型
收费全文 | 3048篇 |
免费 | 286篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 119篇 |
妇产科学 | 42篇 |
基础医学 | 379篇 |
口腔科学 | 84篇 |
临床医学 | 522篇 |
内科学 | 621篇 |
皮肤病学 | 37篇 |
神经病学 | 165篇 |
特种医学 | 221篇 |
外科学 | 303篇 |
综合类 | 60篇 |
一般理论 | 1篇 |
预防医学 | 330篇 |
眼科学 | 41篇 |
药学 | 230篇 |
中国医学 | 2篇 |
肿瘤学 | 173篇 |
出版年
2021年 | 30篇 |
2020年 | 20篇 |
2019年 | 43篇 |
2018年 | 48篇 |
2017年 | 34篇 |
2016年 | 42篇 |
2015年 | 52篇 |
2014年 | 73篇 |
2013年 | 106篇 |
2012年 | 119篇 |
2011年 | 138篇 |
2010年 | 76篇 |
2009年 | 111篇 |
2008年 | 128篇 |
2007年 | 127篇 |
2006年 | 135篇 |
2005年 | 146篇 |
2004年 | 96篇 |
2003年 | 127篇 |
2002年 | 111篇 |
2001年 | 102篇 |
2000年 | 91篇 |
1999年 | 78篇 |
1998年 | 74篇 |
1997年 | 66篇 |
1996年 | 71篇 |
1995年 | 65篇 |
1994年 | 42篇 |
1993年 | 42篇 |
1992年 | 59篇 |
1991年 | 54篇 |
1990年 | 48篇 |
1989年 | 67篇 |
1988年 | 70篇 |
1987年 | 55篇 |
1986年 | 55篇 |
1985年 | 57篇 |
1984年 | 39篇 |
1983年 | 33篇 |
1982年 | 38篇 |
1981年 | 25篇 |
1980年 | 28篇 |
1979年 | 27篇 |
1978年 | 26篇 |
1977年 | 31篇 |
1976年 | 29篇 |
1975年 | 28篇 |
1974年 | 16篇 |
1973年 | 19篇 |
1970年 | 21篇 |
排序方式: 共有3354条查询结果,搜索用时 15 毫秒
1.
Lorraine Greaves Nancy Poole Natalie Hemsing 《Journal of obstetric, gynecologic, and neonatal nursing : JOGNN / NAACOG》2019,48(1):90-98
Rates of smoking during pregnancy remain high in Canada, and cessation rates are low among women who are younger than 24 years and who are socially disadvantaged, that is, have few social and economic resources because of poverty, violence, or mental health issues. On the basis of findings from literature reviews and consultation with policy makers, we developed and operationalized four approaches that can be used by health care providers to tailor interventions for tobacco use in pregnancy. These four approaches are woman centered, trauma informed, harm reducing, and equitable. Public health initiatives that address smoking in young and socially disadvantaged women could be more sharply focused by shifting to such tailored approaches that are grounded in social justice aims, span pre- and postpregnancy periods, and can be used to address women’s social contexts and concerns. 相似文献
2.
3.
4.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
5.
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
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.
The purpose of this pilot study was to observe both relaxed and deep breathing patterns in a convenience sample to determine the incidence of normal versus faulty patterns of respiration. These observations were then combined with respondent answers to a survey on pain history to determine if there is any correlation between faulty breathing and musculo-skeletal pain patterns. If such a correlation can be made, then we propose that clinicians working with chronic pain patients may have improved outcomes if they address and correct faulty breathing patterns. Based on this study, it is suggested to include the evaluation and treatment of faulty respiration in the rehabilitation of chronic musculo-skeletal conditions, most notably cervical pain. 相似文献
10.
Chondrons were isolated from human and canine osteoarthritic cartilage using low-speed homogenization techniques. Changes in chondron morphology were evaluated using differential interference-contrast microscopy, phase-contrast microscopy, and histochemical and ultrastructural methods. Chondrocyte viability was assessed using fluorescein diacetate staining, and chondron metabolism was investigated using autoradiography. The results suggest that initial changes in the collagen and proteoglycan distribution within the chondron are followed by chondrocyte proliferation to form clusters. These techniques offer the potential to study cell matrix interactions in degenerative osteoarthritis. 相似文献