全文获取类型
收费全文 | 598篇 |
免费 | 65篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 15篇 |
妇产科学 | 7篇 |
基础医学 | 83篇 |
口腔科学 | 6篇 |
临床医学 | 62篇 |
内科学 | 113篇 |
皮肤病学 | 3篇 |
神经病学 | 9篇 |
特种医学 | 234篇 |
外科学 | 22篇 |
综合类 | 7篇 |
预防医学 | 61篇 |
眼科学 | 4篇 |
药学 | 25篇 |
肿瘤学 | 16篇 |
出版年
2022年 | 2篇 |
2021年 | 9篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 8篇 |
2014年 | 7篇 |
2013年 | 3篇 |
2012年 | 7篇 |
2011年 | 17篇 |
2010年 | 10篇 |
2009年 | 15篇 |
2008年 | 24篇 |
2007年 | 22篇 |
2006年 | 25篇 |
2005年 | 20篇 |
2004年 | 21篇 |
2003年 | 23篇 |
2002年 | 23篇 |
2001年 | 14篇 |
2000年 | 11篇 |
1999年 | 14篇 |
1998年 | 24篇 |
1997年 | 21篇 |
1996年 | 17篇 |
1995年 | 16篇 |
1994年 | 22篇 |
1993年 | 18篇 |
1992年 | 10篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 24篇 |
1988年 | 23篇 |
1987年 | 28篇 |
1986年 | 23篇 |
1985年 | 20篇 |
1984年 | 23篇 |
1983年 | 14篇 |
1982年 | 12篇 |
1981年 | 19篇 |
1980年 | 15篇 |
1979年 | 3篇 |
1978年 | 13篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 4篇 |
1974年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有669条查询结果,搜索用时 0 毫秒
101.
Tuberculous mediastinal lymphadenopathy in adults 总被引:2,自引:0,他引:2
102.
Young AT; Hunter DW; Castaneda-Zuniga WR; Hulbert JC; Lange P; Reddy P; Mercado S; Amplatz K 《Radiology》1985,154(3):633-638
The authors achieved successful percutaneous extraction of urinary calculi via an intercostal approach in 24 patients. In one patient, a large hydrothorax developed and thoracentesis was required; 2 patients had moderate and 6 minimal pleural fluid collections which did not require treatment. No patient had pneumothorax. Intercostal puncture provides direct access to the upper and middle poles of the kidney when they lie above the twelfth rib and subcostal angulation is not feasible. Such an approach is advantageous for stones in the ureter, as well as renal stones which are inaccessible from the lower pole. Fluoroscopy should be performed when planning the puncture in order to avoid the lung, and a working sheath is recommended. 相似文献
103.
104.
A malignant human urothelial cell line (J82) has been cultured in a serum-free medium (HMRI-1) developed specifically for normal human urothelium. Unlike the normal human urothelium which grew as an attached monolayer, the J82 cells proliferated as free floating cellular aggregates. Comparative growth kinetic studies have shown that the J82 cells, unlike normal cultured urothelial cells, did not require epidermal growth factor, bovine pituitary extract or transferrin as single additives in the HMRI-1. However, deletion of certain combinations of these factors markedly reduced growth. It was concluded that the J82 cells had a reduced dependency on the normal urothelial cell growth factors suggesting that the J82 cells had altered nutritional requirements which might possibly be associated with the production of autocrine growth factors. 相似文献
105.
The dynamics of labor force participation and joblessness during young adulthood influence access to social and material resources and shape exposure to different sources of psychosocial strain. Differences in these dynamics by race, ethnicity, and gender are related to changes in a behavioral determinant of poor health (tobacco use) for young adults aging into midlife. Using discrete-time hazards models, we estimate the relationship between labor force participation in the past year and smoking cessation for US adults (ages 14-21 years in 1979) followed in a population-representative sample until 1998 (i.e. the National Longitudinal Survey of Youth). We assess the unique role of racial, ethnic and gender differences in exposure, vulnerability, and reactivity to employment and joblessness by controlling for social and economic resources obtained through working and by controlling for early life factors that select individuals into certain labor force and smoking trajectories. There are three main findings: (1) joblessness is more strongly associated with persistent daily smoking among women than among men; (2) fewer social and economic resources for women out of the labor force compared to employed women explains their lower cessation rates; and (3) lower cessation among unemployed women compared to employed women can only partially be explained by these resources. These findings illustrate how differential access to work-related social and economic resources is an important mediator of poor health trajectories. Contextual factors such as social norms and psychosocial strains at work and at home may play a unique role among European American men and women in explaining gender differences in smoking. 相似文献
106.
107.
108.
A hybrid digital subtraction angiography technique and noise-reduction algorithm were used to evaluate the carotid bifurcation. Temporal, hybrid, and reduced-noise hybrid images were obtained in right and left anterior oblique projections, and both single- and multiple-frame images were created with each method. The resulting images were graded on a scale of 1 to 5 by three experienced neuroradiologists. Temporal images were preferred over hybrid images (average score = 3.2 and 2.4, respectively). The percentage of nondiagnostic examinations, as agreed upon by two readers, was higher for temporal alone than temporal + hybrid (4 and 1, respectively). In addition, also by agreement between two readers, temporal + hybrid images significantly increased the number of bifurcations seen in two views (87%) compared to temporal subtraction alone (64%). 相似文献
109.
110.
Maturo VG; Zusmer NR; Gilson AJ; Smoak WM; Janowitz WR; Bear BE; Goddard J; Dick DE 《Radiology》1980,137(2):457-463
Innovations in design of a dedicated breast scanner resulted in automation of the scanning process, the production of high resolution images of the whole breast and an efficient mode of image review. The results of clinical evaluation of the prototype of this breast scanner investigating normal breasts as well as benign and malignant breast lesions are presented. 相似文献