全文获取类型
收费全文 | 1519篇 |
免费 | 199篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 74篇 |
妇产科学 | 25篇 |
基础医学 | 179篇 |
口腔科学 | 40篇 |
临床医学 | 174篇 |
内科学 | 328篇 |
皮肤病学 | 12篇 |
神经病学 | 159篇 |
特种医学 | 145篇 |
外科学 | 93篇 |
综合类 | 32篇 |
预防医学 | 236篇 |
眼科学 | 9篇 |
药学 | 151篇 |
1篇 | |
肿瘤学 | 74篇 |
出版年
2019年 | 16篇 |
2018年 | 22篇 |
2017年 | 18篇 |
2016年 | 20篇 |
2015年 | 24篇 |
2014年 | 39篇 |
2013年 | 50篇 |
2012年 | 29篇 |
2011年 | 46篇 |
2010年 | 38篇 |
2009年 | 38篇 |
2008年 | 42篇 |
2007年 | 71篇 |
2006年 | 48篇 |
2005年 | 32篇 |
2004年 | 26篇 |
2003年 | 30篇 |
2002年 | 30篇 |
2001年 | 20篇 |
2000年 | 34篇 |
1999年 | 27篇 |
1998年 | 58篇 |
1997年 | 62篇 |
1996年 | 61篇 |
1995年 | 57篇 |
1994年 | 41篇 |
1993年 | 38篇 |
1992年 | 24篇 |
1991年 | 33篇 |
1990年 | 25篇 |
1989年 | 23篇 |
1988年 | 32篇 |
1987年 | 32篇 |
1986年 | 27篇 |
1985年 | 26篇 |
1984年 | 17篇 |
1983年 | 17篇 |
1982年 | 23篇 |
1981年 | 20篇 |
1980年 | 24篇 |
1978年 | 16篇 |
1977年 | 18篇 |
1976年 | 15篇 |
1975年 | 20篇 |
1973年 | 23篇 |
1970年 | 17篇 |
1933年 | 22篇 |
1932年 | 15篇 |
1930年 | 18篇 |
1927年 | 21篇 |
排序方式: 共有1764条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Carel Bron Michel Wensing Jo LM Franssen Rob AB Oostendorp 《BMC musculoskeletal disorders》2007,8(1):107
Background
Shoulder disorders are a common health problem in western societies. Several treatment protocols have been developed for the clinical management of persons with shoulder pain. However available evidence does not support any protocol as being superior over others. Systematic reviews provide some evidence that certain physical therapy interventions (i.e. supervised exercises and mobilisation) are effective in particular shoulder disorders (i.e. rotator cuff disorders, mixed shoulder disorders and adhesive capsulitis), but there is an ongoing need for high quality trials of physical therapy interventions. Usually, physical therapy consists of active exercises intended to strengthen the shoulder muscles as stabilizers of the glenohumeral joint or perform mobilisations to improve restricted mobility of the glenohumeral or adjacent joints (shoulder girdle). It is generally accepted that a-traumatic shoulder problems are the result of impingement of the subacromial structures, such as the bursa or rotator cuff tendons. Myofascial trigger points (MTrPs) in shoulder muscles may also lead to a complex of symptoms that are often seen in patients diagnosed with subacromial impingement or rotator cuff tendinopathy. Little is known about the treatment of MTrPs in patients with shoulder disorders. 相似文献6.
7.
Normal cerebral perfusion measurements using arterial spin labeling: reproducibility, stability, and age and gender effects. 总被引:4,自引:0,他引:4
Laura M Parkes Waqar Rashid Declan T Chard Paul S Tofts 《Magnetic resonance in medicine》2004,51(4):736-743
Before meaningful conclusions can be drawn from clinical measures of cerebral blood perfusion, the precision of the measurement must be determined and set in the context of inter- and intrasubject sources of variability. This work establishes the reproducibility of perfusion measurements using the noninvasive MRI technique of continuous arterial spin labeling (CASL). Perfusion was measured in 34 healthy normal subjects. Intersubject variability was assessed, and age and gender contributions were estimated. Intersubject variation was found to be large, with up to 100% perfusion difference for subjects of the same age and gender. Repeated measurements in one subject showed that perfusion remains remarkably stable in the short term when compared with intersubject variation and the large capacity for perfusion change in the brain. A significant decrease in the ratio of gray-matter to white-matter perfusion was found with increasing age (0.79% per year (P < 0.0005)). This appears to be due mainly to a reduction in gray-matter perfusion, which was found to decrease by 0.45% per year (P = 0.04). Regional analysis suggested that the gray-matter age-related changes were predominantly localized in the frontal cortex. Whole-brain perfusion was 13% higher (P = 0.02) in females compared to males. 相似文献
8.
The pattern of cancer in white and Asian (Indian, Pakistani, and Bangladeshi) children living in the West Midlands Health Authority Region was investigated using age standardised incidence rates. Two sets of rates were calculated, a 10 year rate (1982-91) using survey based estimates of the ethnic population and a four year rate (1989-92) using the ethnic population counts from the 1991 census. The 10 year rates showed a significantly higher annual incidence of cancer in Asian (159.1/million/year) than in white (130.8) children. The pattern of cancers in Asian children was different, with an excess of lymphomas and germ cell tumours, and a deficit of rhabdomyosarcomas. These findings were confirmed by the four year rates. Although underestimation of the Asian population probably contributes to the apparent excess, there remains cause for concern that UK Asian children may be at higher risk of cancer. Accurate ethnic population figures and confirmatory studies are urgently required. 相似文献
9.
The sonographic appearances in postpartum thyroiditis. 总被引:2,自引:0,他引:2
H Adams M C Jones S Othman J H Lazarus A B Parkes R Hall D I Phillips C J Richards 《Clinical radiology》1992,45(5):311-315
During the postpartum period about 50% of women with circulating thyroid autoantibodies develop a transient autoimmune thyroiditis. To determine the sonographic appearances in postpartum thyroiditis (PPT), serial ultrasound (US) scans of the thyroid were performed in 135 postpartum women who were divided into three clinical groups: Group 1, 37 antibody positive subjects who developed PPT; Group 2, 28 antibody positive subjects in whom thyroid function remained normal; Group 3, 70 antibody negative controls. Thyroid hypoechogenicity was observed in 14/31 patients (45%) who were scanned between 4 and 8 weeks postpartum and who subsequently developed PPT (Group 1) compared with 4/24 patients (17%) in Group 2 (P less than 0.05) and 1/65 patients (1.5%) in Group 3 (P less than 0.001). In antibody positive patients, the positive predictive value of an abnormal scan during this period was 78%. Between 15 and 25 weeks postpartum thyroid hypoechogenicity was present in 32/37 patients (86%) in Group 1 compared with 11/28 patients (39%) in Group 2 (P less than 0.001) and 2/70 patients (3%) in Group 3 (P less than 0.001). Sonographic abnormality persisted beyond 32 weeks postpartum in 36/41 antibody positive patients (87%) who had exhibited thyroid hypoechogenicity earlier during the study and who had late scans. The characteristic US appearance in PPT is thyroid hypoechogenicity. The role of sonography in the prediction, diagnosis and follow up of patients with PPT is discussed. 相似文献
10.
F. Parkes Weber 《Journal of the Royal Society of Medicine》1939,32(5):417-418