首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5391篇
  免费   516篇
  国内免费   21篇
耳鼻咽喉   95篇
儿科学   265篇
妇产科学   183篇
基础医学   872篇
口腔科学   71篇
临床医学   793篇
内科学   1110篇
皮肤病学   68篇
神经病学   326篇
特种医学   231篇
外国民族医学   2篇
外科学   547篇
综合类   82篇
一般理论   12篇
预防医学   573篇
眼科学   47篇
药学   347篇
中国医学   4篇
肿瘤学   300篇
  2021年   82篇
  2020年   46篇
  2019年   73篇
  2018年   95篇
  2017年   64篇
  2016年   87篇
  2015年   92篇
  2014年   95篇
  2013年   132篇
  2012年   213篇
  2011年   227篇
  2010年   125篇
  2009年   116篇
  2008年   253篇
  2007年   235篇
  2006年   215篇
  2005年   200篇
  2004年   223篇
  2003年   202篇
  2002年   186篇
  2001年   184篇
  2000年   212篇
  1999年   149篇
  1998年   93篇
  1997年   66篇
  1996年   60篇
  1995年   63篇
  1994年   68篇
  1993年   65篇
  1992年   141篇
  1991年   133篇
  1990年   128篇
  1989年   137篇
  1988年   118篇
  1987年   110篇
  1986年   109篇
  1985年   118篇
  1984年   73篇
  1983年   68篇
  1982年   47篇
  1981年   49篇
  1980年   43篇
  1979年   68篇
  1978年   59篇
  1977年   57篇
  1976年   46篇
  1975年   45篇
  1974年   66篇
  1973年   44篇
  1970年   41篇
排序方式: 共有5928条查询结果,搜索用时 220 毫秒
71.
Six villages in Lofa County, north-west Liberia, and one near the coast were surveyed for the presence of indirect fluorescent antibodies (IFA) to Lassa virus (LV). Prevalences were similar among males and females, and among various age groups. The prevalence of IFA positive sera, 6.4%, in two roadside villages was significantly higher than in two matched villages "in the bush", 1.9%. It was also higher in Gbanwei, a roadside village which did not maintain traditional sanitary measures, than in Zuwulo, similarly located but with maintenance of clean-swept areas without shrubbery or rubble between the houses. In another pair of villages, the one adjacent to a Mission Clinic with a very high prevalence of IFA positive staff members had significantly higher prevalence, 14.1%, than did the other, a roadside village with 5.1% seropositives. LV antibodies were also found in 4.3% of the inhabitants of a small coastal village near Robertsfield International Airport. Though LV infections are more common in villages in which traditional practices have been modified, they are present even in villages which are relatively unchanged. In the former they appear to be continuous while sporadic in the latter. The prevalences of IFA in the villages with the highest rates are about one third of what is found in personnel of hospitals near them, suggesting that hospital staff members acquire infections from patients as well as from the communities in which they live.  相似文献   
72.
73.
同种异体黑素细胞移植治疗白癜风   总被引:2,自引:2,他引:0  
卢涛  高天文  刘玉峰  李春英  孙林潮 《医学争鸣》2001,22(12):1147-1147
0 引言 白癜风患者免疫紊乱 ,黑素细胞 (melanocyte,MC)异体移植有可能不被排斥 ,治疗如成功将有很大临床前景 [1 ] .探索同种异体黑素细胞移植后的效果很有意义 .1 病例报告 女 ,2 7岁 ,确诊白癜风 (稳定期 ) ,患者皮肤自幼出现色素脱失斑 ,逐渐增多扩大 . 1996年外用“敏白灵”,前2 mo有效 . 1999- 0 7外用补骨酯酊 ,日服 5 g· L- 1 硫酸铜 10m L和中药 1剂 ,转移因子 4m L ,sc,1· 2 d- 1 .皮损缩小 ,4mo后稳定 .用健康男青年环切的包皮培养 MC,第 4代大约80 %融合时 ,用 2 .5 g· L- 1 胰酶消化 5 min,加入含 2 0 0 g·L- 1小…  相似文献   
74.
The risk of psychiatric patient assaults on staff members is increasing yearly, with resultant increases in employee victim suffering, medical expense, and lost productivity. Traditionally considered a clinician responsibility, the management of patient violence also has important administrative implications. This article presents a review of the risk factors associated with violence that includes the characteristics of patients who assault but adds the characteristics of employee victims of such assaults as well as contextual variables. Additional data from a two-year study of a peer-help crisis intervention program for employee victims of patient assaults are included. The mental health administrative implications of this approach are outlined.  相似文献   
75.
The effect of big endothelin-1 (big ET-1) and its conversion to endothelin-1 (ET-1) in rabbit cerebral arteries were examined. Big ET-1 and ET-1 induced concentration-dependent contractions in the basilar artery; ET-1 was approximately 8 times more potent than big ET-1. The metalloprotease inhibitor phosphoramidon (30 ol/1) almost abolished the contractile response to big ET-1, whereas the ET-1-induced contraction was unaffected. Removal of the endothelium did not attenuate the big ET-1-induced contraction. ET-1 was approximately 14 times more potent than endothelin-3 (ET-3) to elicit contraction. The contractions induced by big ET-1, ET-1 and ET-3 were all inhibited by the ETA receptor antagonist BQ 123 (3 mol/l). The ETB receptor antagonist IRL 1038 (3 mol/l) had no effect on the contractile responses to big ET-1 and ET 1, but produced a small inhibition of the ET-3-induced contraction. Formation of ET-1 was demonstrated in membrane fractions of cerebral arteries incubated with big ET-1 as measured by high pressure liquid chromatography followed by radioimmunoassay. These results suggest that externally applied big ET-1 is converted to ET-1 by a phosphoramidon-sensitive endothelin converting enzyme present in the vascular smooth muscle cells. The ET-1 formed subsequently mediates the big ET-1-induced contraction by activation of mainly ETA receptors, although a small contribution of ETB receptors cannot be excluded.  相似文献   
76.
OBJECTIVE: To study the effects of participation rate in sampling on "normative" bone mass data. DESIGN: This was a comparison between two randomly selected samples from the same population. The participation rates in the two samples were 61.9% and 83.6%. Measurements were made of bone mass at different skeletal sites and of muscle strength, as well as an assessment of physical activity. SETTING: Malmö, Sweden. SUBJECTS: There were 230 subjects (117 men, 113 women), aged 21 to 42 years. RESULTS: Many subjects participated in both studies (163). Those who took part only in the study with the higher participation rate (67) almost invariably had higher values for bone mass density at the sites measured (up to 7.6% for men) than participants in the study with the lower participation rate. No differences in muscle strength were recorded. CONCLUSION: A high degree of compliance is important to achieve a reliable result in determining normal values in population based studies.  相似文献   
77.
Respiratory function changes after asbestos pleurisy.   总被引:10,自引:7,他引:3       下载免费PDF全文
P H Wright  A Hanson  L Kreel    L H Capel 《Thorax》1980,35(1):31-36
Six patients with radiographic evidence of diffuse pleural thickening after industrial asbestos exposure are described. Five had computed tomography of the thorax. All the scans showed marked circumferential pleural thickening often with calcification, and four showed no significant evidence of intrapulmonary fibrosis (asbestosis). Lung function testing showed reduction of the inspiratory capacity and the single-breath carbon monoxide transfer factor (TLCO). The transfer coefficient, calculated as the TLCO divided by the alveolar volume determined by helium dilution during the measurement of TLCO, was increased. Pseudo-static compliance curves showed markedly more negative intrapleural pressures at all lung volumes than found in normal people. These results suggest that the circumferential pleural thickening was preventing normal lung expansion despite abnormally great distending pressures. The pattern of lung function tests is sufficiently distinctive for it to be recognised in clinical practice, and suggests that the lungs are held rigidly within an abnormal pleura. The pleural thickening in our patients may have been related to the condition described as "benign asbestos pleurisy" rather than the interstitial fibrosis of asbestosis.  相似文献   
78.
79.
80.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号