全文获取类型
收费全文 | 1629篇 |
免费 | 149篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 75篇 |
妇产科学 | 34篇 |
基础医学 | 186篇 |
口腔科学 | 48篇 |
临床医学 | 139篇 |
内科学 | 394篇 |
皮肤病学 | 27篇 |
神经病学 | 36篇 |
特种医学 | 428篇 |
外科学 | 200篇 |
综合类 | 43篇 |
一般理论 | 1篇 |
预防医学 | 42篇 |
眼科学 | 9篇 |
药学 | 65篇 |
1篇 | |
肿瘤学 | 40篇 |
出版年
2023年 | 6篇 |
2022年 | 10篇 |
2021年 | 12篇 |
2020年 | 9篇 |
2019年 | 10篇 |
2018年 | 11篇 |
2017年 | 16篇 |
2016年 | 11篇 |
2015年 | 18篇 |
2014年 | 37篇 |
2013年 | 40篇 |
2012年 | 23篇 |
2011年 | 33篇 |
2010年 | 42篇 |
2009年 | 57篇 |
2008年 | 40篇 |
2007年 | 54篇 |
2006年 | 44篇 |
2005年 | 40篇 |
2004年 | 29篇 |
2003年 | 30篇 |
2002年 | 25篇 |
2001年 | 31篇 |
2000年 | 25篇 |
1999年 | 26篇 |
1998年 | 84篇 |
1997年 | 80篇 |
1996年 | 81篇 |
1995年 | 68篇 |
1994年 | 44篇 |
1993年 | 60篇 |
1992年 | 14篇 |
1991年 | 19篇 |
1990年 | 36篇 |
1989年 | 61篇 |
1988年 | 51篇 |
1987年 | 64篇 |
1986年 | 61篇 |
1985年 | 74篇 |
1984年 | 46篇 |
1983年 | 37篇 |
1982年 | 35篇 |
1981年 | 35篇 |
1980年 | 38篇 |
1979年 | 12篇 |
1978年 | 19篇 |
1977年 | 29篇 |
1976年 | 22篇 |
1975年 | 23篇 |
1970年 | 2篇 |
排序方式: 共有1782条查询结果,搜索用时 15 毫秒
101.
Multiple myeloma: evaluation by CT 总被引:3,自引:0,他引:3
Although patients who have multiple myeloma usually have straightforward clinical symptoms and corroborative radiographs, in some instances, these patients will present atypically, with symptoms suggesting active disease but radiographs that are normal or nonspecific. We reviewed the records of 32 patients who had documented multiple myeloma and had undergone CT examinations, assessing the value of those examinations. Although CT is not indicated in all patients who have multiple myeloma, it is especially useful in patients who have bone pain and normal or nonspecific radiographs. CT provided confirmatory information in all cases in which lesions were seen on radiographs. CT also frequently demonstrated a greater extent of disease than could be appreciated on the radiographs. 相似文献
102.
BACKGROUND—IgG subclass deficiency is often
associated with recurrent pulmonary infections. The prevalence of
deficiency in a large well characterised group of patients with
bronchiectasis has not previously been established.
METHODS—Serum IgG subclass concentrations in 89 patients with bronchiectasis were compared with those obtained from a group of 82age and sex matched normal healthy controls. Sputum IgG subclass concentrations were also assessed in 44 of the patients. Albumin was measured as a marker of protein transudation from plasma to determine the degree of local IgG subclass production.
RESULTS—The serum concentrations of IgG1, IgG2 and IgG3 were increased in the patients compared with the control group whereas IgG4 concentrations were not. There was an overall incidence of deficiency of 1% for subclasses 1-3 and 5% for subclass 4 in patients with bronchiectasis based on observed concentrations being below the lower limit of the control group range. The concentrations of IgG subclasses in sputum were partly dependent upon the degree of inflammation as assessed by the macroscopic appearance of purulence. A comparison of the ratio of sputum:serum subclass concentration and sputum:serum albumin, however, revealed that all of the subclasses were present at greater concentrations than could be accounted for by transudation alone.
CONCLUSIONS—A new normal control range for serum IgG subclasses has been established and from this range it was found that IgG subclass deficiency in a group of unselected patients with bronchiectasis was comparatively rare. A significant degree of local IgG production was also suggested in the lungs of these patients.
相似文献
METHODS—Serum IgG subclass concentrations in 89 patients with bronchiectasis were compared with those obtained from a group of 82age and sex matched normal healthy controls. Sputum IgG subclass concentrations were also assessed in 44 of the patients. Albumin was measured as a marker of protein transudation from plasma to determine the degree of local IgG subclass production.
RESULTS—The serum concentrations of IgG1, IgG2 and IgG3 were increased in the patients compared with the control group whereas IgG4 concentrations were not. There was an overall incidence of deficiency of 1% for subclasses 1-3 and 5% for subclass 4 in patients with bronchiectasis based on observed concentrations being below the lower limit of the control group range. The concentrations of IgG subclasses in sputum were partly dependent upon the degree of inflammation as assessed by the macroscopic appearance of purulence. A comparison of the ratio of sputum:serum subclass concentration and sputum:serum albumin, however, revealed that all of the subclasses were present at greater concentrations than could be accounted for by transudation alone.
CONCLUSIONS—A new normal control range for serum IgG subclasses has been established and from this range it was found that IgG subclass deficiency in a group of unselected patients with bronchiectasis was comparatively rare. A significant degree of local IgG production was also suggested in the lungs of these patients.
相似文献
103.
Insufficiency fractures in the supraacetabular region were identified in five women, aged 55-83 years. Factors contributing to the diminished resistance of their bones included postmenopausal osteoporosis, steroid therapy, radiation therapy, and rheumatoid arthritis. The supraacetabular fractures were seen on routine radiographs as hazy bands of sclerosis located immediately above and parallel to the acetabular roof. All five patients had additional fractures in the spine or pelvis. Supraacetabular insufficiency fractures may be an unsuspected cause of hip pain, especially in older women. 相似文献
104.
105.
106.
107.
108.
109.
110.
A number of surgical clips and other metallic materials embedded within patients have ferromagnetic properties that present a potential hazard when in the strong fields associated with magnetic resonance imaging. Several types of magnetometers and metal detectors were investigated as possible pre-imaging screening devices. The sensitivities and costs of these devices are given. 相似文献