全文获取类型
收费全文 | 1719篇 |
免费 | 294篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 101篇 |
妇产科学 | 19篇 |
基础医学 | 95篇 |
口腔科学 | 42篇 |
临床医学 | 285篇 |
内科学 | 576篇 |
皮肤病学 | 61篇 |
神经病学 | 171篇 |
特种医学 | 279篇 |
外科学 | 201篇 |
综合类 | 31篇 |
预防医学 | 55篇 |
眼科学 | 16篇 |
药学 | 53篇 |
中国医学 | 1篇 |
肿瘤学 | 53篇 |
出版年
2024年 | 9篇 |
2023年 | 52篇 |
2022年 | 13篇 |
2021年 | 28篇 |
2020年 | 90篇 |
2019年 | 13篇 |
2018年 | 88篇 |
2017年 | 70篇 |
2016年 | 71篇 |
2015年 | 60篇 |
2014年 | 95篇 |
2013年 | 110篇 |
2012年 | 48篇 |
2011年 | 37篇 |
2010年 | 78篇 |
2009年 | 110篇 |
2008年 | 48篇 |
2007年 | 48篇 |
2006年 | 46篇 |
2005年 | 27篇 |
2004年 | 17篇 |
2003年 | 11篇 |
2002年 | 15篇 |
2001年 | 29篇 |
2000年 | 12篇 |
1999年 | 24篇 |
1998年 | 80篇 |
1997年 | 95篇 |
1996年 | 78篇 |
1995年 | 69篇 |
1994年 | 49篇 |
1993年 | 52篇 |
1992年 | 26篇 |
1991年 | 14篇 |
1990年 | 25篇 |
1989年 | 52篇 |
1988年 | 42篇 |
1987年 | 26篇 |
1986年 | 20篇 |
1985年 | 20篇 |
1984年 | 16篇 |
1983年 | 9篇 |
1982年 | 14篇 |
1981年 | 14篇 |
1980年 | 14篇 |
1979年 | 8篇 |
1978年 | 8篇 |
1977年 | 9篇 |
1976年 | 10篇 |
1971年 | 8篇 |
排序方式: 共有2052条查询结果,搜索用时 15 毫秒
991.
992.
Background
Barriers to oral health utilization are many, but those that are significant for our environment are not yet clear. The current study was designed to identify and graduate the barriers to receipt of oral health care among a cross-section of patients attending our centre. We also investigated the influence of socio demographic factors on the highly rated barriers.Methods
This cross-sectional study was conducted among patients visiting UCH, Ibadan using a self-administered questionnaire. Socio-demographic variables and oral health care seeking behaviour were requested and in addition, the respondents were asked to rank 11 listed barriers to receipt of oral health care and any other barriers they may think of in order of strength. Factor analysis was employed in order to identify four factors with the highest loading. The mean scores were compared using t-test and one-way ANOVA and the level of significance was set at 0.05Results
Only 400 questionnaires were properly filled (84.9%) out of the 471 that were administered. The mean age of these participants was 37.85±15.38 years. Most of the respondents (55.8%) consulted the dentists only when there was pain while 109(27.3%) had never visited the dentist. Fear of dental injection, cost of treatment, feeling of insecurity when the dentist is operating and disturbing noise from dental drill were the major barriers. There was a statistically significant association between age groups and feeling of insecurity (p=006).Conclusion
The major barriers to oral health care utilization among our patients were fear related. 相似文献993.
994.
Endoscopic insertion of plastic or metal stents is a wellestablished treatment for malignant biliary obstruction. The major
limitation of this technique is stent occlusion. Duodenobiliary reflux has been considered a key contributor to stent occlusion.
The presence of plant fibers in 35% to 60% of occluded stents on confocal laser microscopy has further confirmed the presence
of reflux when the stent is placed across the papilla. Antireflux stents address this problem by allowing normal antegrade
flow but preventing reflux. Recent studies comparing these antireflux stents with the standard Tannenbaum stents have shown
significantly prolonged patency. Although initial results are encouraging, larger randomized trials are required to establish
efficacy. 相似文献
995.
Hypertension is one of the leading causes of death and disability in developing countries. The increasing burden of hypertension
in these countries has been attributed to several indicators of economic progress such as increased life expectancy, urbanization
and its attendant lifestyle changes, and the overall epidemiologic transition these countries are experiencing currently.
The public health response to this challenge must be to promote health among all sections of the populations of these countries,
and a concerted effort to promote awareness about hypertension, its risk factors, and risk behaviors. The health policies
of these countries need to be reoriented to include chronic diseases in their ambit. These efforts have the potential to reduce
the emergence or lessen the toll of hypertension and its complication in many parts of the developing world. 相似文献
996.
997.
可重复性小鼠局灶性脑缺血/再灌注模型的探讨 总被引:1,自引:1,他引:0
目的介绍一种标准的小鼠局灶性脑缺血/再灌注模型的制作方法,并观察不同脑缺血/再灌注时间脑梗死体积和脑水肿的变化。方法用腔内线栓法制作脑缺血/再灌注动物模型,用TTC染色法进行脑大体观察,用甲酚紫染色法观察脑切片梗死灶,用脑血流激光多普勒监测脑血流的变化,用ImageJ软件计算脑梗死体积和脑水肿。结果当线栓封闭大脑中动脉时,脑血流就会急剧下降至最低水平,拔出线栓后脑血流迅速上升至缺血前水平。脑缺血后,脑片上呈现明显的梗死灶,脑梗死体积和脑水肿的大小较恒定。脑缺血90min再灌注24h组梗死体积、脑水肿体积、脑水肿百分数及神经功能缺损程度均显著大于脑缺血30min再灌注24h组(P<0.001)。脑缺血30min/再灌注72h脑水肿非常明显(72.6±4.3)mm3,再灌注7d时脑水肿开始减退,仅为(50.9±4.1)mm3,再灌注30d时脑容积出现萎缩,脑水肿呈负值(-20.1±1.8)mm3。结论该小鼠局灶性脑缺血/再灌注模型具有重复性好、容易操作的优点。脑缺血30min就可造成不可逆性脑损害,脑水肿在再灌注72h即达到高峰。 相似文献
998.
Expansions of CAG repeat tracts are frequent in a yeast mutant defective in Okazaki fragment maturation 总被引:16,自引:4,他引:12
To understand the causes of CAG repeat tract changes that occur in the
passage of human disease alleles, we are studying the effect of replication
and repair mutations on CAG repeat tracts embedded in a yeast chromosome.
In this report, we examine the effect of a mutation in the RTH1/RAD27 gene
encoding a deoxyribonuclease needed for removal of excess nucleotides at
the 5'-end of Okazaki fragments. Deletion of the RTH1/RAD27 gene has two
effects on CAG tracts. First, the rth1/rad27 mutation destabilizes CAG
tracts. Second, although most tract length changes in wild-type yeast cells
are tract contractions, approximately half of the changes that occur as a
result of the rth1/rad27 mutation are expansions of one or more repeat
units. These results support the hypothesis that tract expansions that
occur during passage of human disease alleles bearing expanded CAG tracts
result from excess DNA synthesis on the lagging strand of replication.
相似文献
999.
K Karthikeyan PK Kaviarasan DM Thappa 《Journal of the European Academy of Dermatology and Venereology》2002,16(1):72-73
Urethral caruncle in a 60-year-old male labourer is being reported. Its occurrence in male urethra has not been reported so far in the literature. 相似文献
1000.