全文获取类型
收费全文 | 1160篇 |
免费 | 70篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 72篇 |
妇产科学 | 11篇 |
基础医学 | 105篇 |
口腔科学 | 31篇 |
临床医学 | 104篇 |
内科学 | 274篇 |
皮肤病学 | 21篇 |
神经病学 | 70篇 |
特种医学 | 244篇 |
外科学 | 66篇 |
综合类 | 59篇 |
预防医学 | 63篇 |
眼科学 | 20篇 |
药学 | 43篇 |
中国医学 | 9篇 |
肿瘤学 | 36篇 |
出版年
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 6篇 |
2019年 | 11篇 |
2018年 | 13篇 |
2017年 | 10篇 |
2016年 | 7篇 |
2015年 | 19篇 |
2014年 | 39篇 |
2013年 | 63篇 |
2012年 | 33篇 |
2011年 | 34篇 |
2010年 | 38篇 |
2009年 | 66篇 |
2008年 | 32篇 |
2007年 | 56篇 |
2006年 | 32篇 |
2005年 | 35篇 |
2004年 | 27篇 |
2003年 | 25篇 |
2002年 | 25篇 |
2001年 | 15篇 |
2000年 | 17篇 |
1999年 | 17篇 |
1998年 | 78篇 |
1997年 | 53篇 |
1996年 | 63篇 |
1995年 | 44篇 |
1994年 | 49篇 |
1993年 | 44篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 11篇 |
1989年 | 39篇 |
1988年 | 27篇 |
1987年 | 25篇 |
1986年 | 19篇 |
1985年 | 12篇 |
1984年 | 16篇 |
1983年 | 15篇 |
1982年 | 15篇 |
1981年 | 20篇 |
1980年 | 13篇 |
1979年 | 9篇 |
1978年 | 9篇 |
1977年 | 16篇 |
1976年 | 8篇 |
1975年 | 11篇 |
1973年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有1239条查询结果,搜索用时 15 毫秒
101.
102.
Hasegawa BH; Naimuddin S; Dobbins JT d; Mistretta CA; Peppler WW; Hangiandreou NJ; Cusma JT; McDermott JC; Kudva BV; Melbye KM 《Radiology》1986,159(2):537-543
The feasibility of producing patient-specific beam attenuators for chest radiography has been investigated using an anthropomorphic phantom and a human volunteer. A low-dose test exposure is digitized, processed, and used to print a small cerium filter, which is placed in the x-ray beam near the collimator. The final radiograph is recorded on film. The technique results in relatively uniform film exposure, so that structures in all regions of the chest are simultaneously displayed with optimal film contrast. The equalized exposure improves image quality in the normally underpenetrated regions and reduces the role of cross-scatter from the lungs. The image is analogous to optical or computer-processed unsharp masking techniques, but the processing is accomplished in the x-ray beam and results in an improved exposure distribution, giving advantages that cannot be achieved with image processing techniques alone. 相似文献
103.
104.
A normal variant, the foraminal spur, is described in five patients. It was seen on computed tomographic studies as a bony process extending from either the pars or the pedicle into the neuroforamen dorsal to the nerve root. In four of the cases it was seen bilaterally. None of the patients had any symptoms related to these spurs. No associated disease of the neuroforamen or facet was present. These spurs most likely represent ossification of the ligamentum flavum at its point of insertion and should not be mistaken for osteophytes, free disk fragments that have calcified, or fracture fragments. Sagittal reformations are helpful in visualizing the extent of the foraminal spurs. 相似文献
105.
106.
107.
Gerard de Vries Rob AH van Hest Conny CA Burdo Dick van Soolingen Jan H Richardus 《BMC infectious diseases》2009,9(1):151
Background
DNA fingerprinting of Mycobacterium tuberculosis isolates offers better opportunities to study links between tuberculosis (TB) cases and can highlight relevant issues in urban TB control in low-endemic countries. 相似文献108.
AIM: To determine the incidence of hypocalcaemia in critically ill children with meningococcal disease. METHODS: In a prospective cohort study, 70 of 80 patients admitted consecutively with a clinical diagnosis of meningococcal disease to intensive care had measurements of total and ionised calcium on admission. Parathormone and calcitonin were measured in a proportion of the children. RESULTS: Total and ionised calcium concentrations were low in 70% of the children. There was a weak relation of calcium concentration to the volume of blood derived colloid which had been given, but a good relation to disease severity, where sicker children had lower calcium concentrations. Although the parathormone concentration was higher in children with lower calcium concentrations, some children had low ionised calcium concentrations, without an increase of parathormone concentration. Serum calcitonin concentration was not related to calcium concentrations. CONCLUSION: Hypocalcaemia is common in meningococcal disease. 相似文献
109.
110.
Rosebrough SF; Grossman ZD; McAfee JG; Kudryk BJ; Subramanian G; Ritter- Hrncirik CA; Witanowski LS; Tillapaugh-Fay G; Urrutia E 《Radiology》1987,162(2):575-577
Radioimmunoimaging of fresh canine venous thrombi with a murine monoclonal antibody specific for human and dog fibrin has been reported. Successful imaging of canine deep venous thrombi 1, 3, and 5 days old at the time of antibody injection is reported. Images were positive in all dogs, and the uptake of fibrin-specific antibody was equivalent to that of fresh thrombi. 相似文献