全文获取类型
收费全文 | 306508篇 |
免费 | 22382篇 |
国内免费 | 8734篇 |
专业分类
耳鼻咽喉 | 2272篇 |
儿科学 | 5463篇 |
妇产科学 | 5207篇 |
基础医学 | 46431篇 |
口腔科学 | 5671篇 |
临床医学 | 25065篇 |
内科学 | 44408篇 |
皮肤病学 | 4380篇 |
神经病学 | 17445篇 |
特种医学 | 8739篇 |
外国民族医学 | 30篇 |
外科学 | 22261篇 |
综合类 | 41626篇 |
现状与发展 | 42篇 |
一般理论 | 20篇 |
预防医学 | 32415篇 |
眼科学 | 3786篇 |
药学 | 36596篇 |
118篇 | |
中国医学 | 15888篇 |
肿瘤学 | 19761篇 |
出版年
2024年 | 612篇 |
2023年 | 4083篇 |
2022年 | 9441篇 |
2021年 | 12407篇 |
2020年 | 10541篇 |
2019年 | 9995篇 |
2018年 | 9998篇 |
2017年 | 10623篇 |
2016年 | 10978篇 |
2015年 | 10875篇 |
2014年 | 15170篇 |
2013年 | 19724篇 |
2012年 | 16245篇 |
2011年 | 18907篇 |
2010年 | 13396篇 |
2009年 | 13241篇 |
2008年 | 14417篇 |
2007年 | 15678篇 |
2006年 | 14473篇 |
2005年 | 13103篇 |
2004年 | 11330篇 |
2003年 | 9995篇 |
2002年 | 7994篇 |
2001年 | 7142篇 |
2000年 | 6086篇 |
1999年 | 5249篇 |
1998年 | 4357篇 |
1997年 | 4437篇 |
1996年 | 3971篇 |
1995年 | 3627篇 |
1994年 | 3417篇 |
1993年 | 2931篇 |
1992年 | 2570篇 |
1991年 | 2372篇 |
1990年 | 1999篇 |
1989年 | 1699篇 |
1988年 | 1625篇 |
1987年 | 1345篇 |
1986年 | 1242篇 |
1985年 | 1931篇 |
1984年 | 1545篇 |
1983年 | 1113篇 |
1982年 | 1147篇 |
1981年 | 924篇 |
1980年 | 831篇 |
1979年 | 640篇 |
1978年 | 454篇 |
1977年 | 354篇 |
1976年 | 334篇 |
1975年 | 229篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
This paper proposes that an individual's self-assessed health (SAH) does not only suffer from systematic reporting bias and adaptation bias but is also biased owing to confounding health norm effects. Using 13 waves of the British Household Panel Survey covering the period 1991–2005, I show that, while there is a negative and statistically significant correlation between SAH and individuals' own health problem index, this negative effect reduces with the average number of health problems per (other) family member. The relative health bias is small, however, which implies that measures of SAH may not suffer seriously from systematic health norm bias. This is an important finding for researchers working with SAH data as it indicates that we do not have to worry too much about controlling for confounding influences from the health of other household members when estimating SAH regression equations. 相似文献
93.
Marco Antonio Palma Rocio Ortiz Carlos Alvarez-Dardet Maria T. Ruiz 《Social science & medicine (1982)》2009
The possible effect of Government Consumption (a component of Gross Domestic Product (GDP)) on attainment of the hunger Millennium Development Goal (MDG1) was analyzed by evaluating the effect of macroeconomic, social, demographic and policy variables on average undernourished population. Eighty-four developing countries with data available on undernourished population were included in an ecological study. Regression models were applied to explore possible determinants of Undernourished between 1990 and 2004 and consequent achievement of the projected 2004 MDG1. In 2004, 1.4% of the overall undernourished population in the studied countries [70.16 million people] was in excess of the projected level required to meet MDG1. The multiple linear regression showed significant associations between Undernourished and poverty levels, the Gini Index, rural population and Government Consumption. The multiple logistic regression showed significant associations between achievement of projected 2004 MDG1 levels and Government Consumption and the Gini Index. The significant associations between Undernourished and Government Consumption suggest that the effects of GDP components on social conditions call for more thorough research and that policymakers such as governments and international financial institutions need to ensure that changes in distributive and redistributive policies do not negatively affect the possibility of achieving MDG1. 相似文献
94.
Ashwin A Kallianpur Rajinder Parshad Maya Dehran Priya Hazrah 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2007,11(2):229-234
BACKGROUND AND OBJECTIVES: Feasibility of ambulatory laparoscopic inguinal hernia repair in developing countries is not known due to lack of dedicated outpatient centers. This study prospectively evaluated the feasibility of outpatient discharge after laparoscopic total extraperitoneal inguinal hernia repair done in combination with in-hospital services and its impact on quality of life. METHODS: Forty patients were studied who had uncomplicated inguinal hernias and fulfilled the selection criteria. Quality of life was evaluated by using the SF-12 questionnaire. RESULTS: Ninety percent of patients could be discharged as outpatients. Four patients required admission. No major complications or readmissions occurred. Physical components of quality of life deteriorated in the immediate postoperative period but improved to above preoperative levels within one month. A transient deterioration in subgroups of the mental health component was observed, which recovered to normal in less than a week. There was no significant alteration in the emotional component. There has been no recurrence at a median follow-up of 25 months. CONCLUSION: It was feasible to safely perform outpatient TEP in combination with routine in-hospital services without increasing complications or causing any adverse impact on quality of life. This was possible subject to adherence to proper selection and discharge criteria. 相似文献
95.
E. Drakaki E. Borisova M. Makropoulou L. Avramov A. A. Serafetinides I. Angelov 《Skin research and technology》2007,13(4):350-359
BACKGROUND/PURPOSE: Laser-induced autofluorescence spectroscopy provides excellent possibilities for medical diagnostics of different tissue pathologies including cancer. However, to create the whole picture of pathological changes, investigators collect spectral information from patients in vivo or they study different tumor models to obtain objective information for fluorescent properties of every kind of healthy and diseased tissue. Therefore, it is very important to find the most appropriate, and close to the human skin, animal samples from the fluorescence point of view, which will allow the extrapolation of the animal data to human spectroscopic diagnostics. METHODS: In the present work, we examined the autofluorescence properties of different animal skin tissues, which are considered as the most common skin models. A nitrogen laser was used as an excitation source. Samples of healthy mouse, chicken and pig skin in vivo and/or ex vivo were studied and were compared with results obtained from investigations of healthy human skin in vivo. RESULTS AND CONCLUSION: Specific features of the recorded spectra are discussed and the possible origin of the obtained fluorescence signals is proposed. Quantitative evaluation of data extrapolation for each skin type is also depicted. 相似文献
96.
风疹易感人群婚前风疹疫苗接种预防先天性风疹综合征 总被引:1,自引:0,他引:1
目的探讨婚前风疹易感人群风疹疫苗接种在提高孕妇对风疹的免疫力,预防先天性风疹综合征中的作用.方法对10 913例婚前风疹病毒抗体IgG阴性者给予国产风疹减毒活疫苗注射.3个月随防671例,比较风疹疫苗接种前后该地区孕妇近期风疹感染的发病率.结果818例风疹病毒抗体IgG阴性者接种后抗体转阳率为99.8%.风疹疫苗接种前后3年孕妇近期风疹感染率分别为0.37%及0.08%,有明显下降,有非常显著差异(P<0.001).结论应用国产风疹减毒活疫苗对婚前易感人群作预防接种可提高育龄妇女对风疹的免疫力,降低孕期风疹感染的发生率,是预防先天性风疹综合征及风疹致畸的有效、安全措施. 相似文献
97.
Ferry Verbaan Inger van Dam Yoshinubu Takakura Mitsuru Hashida Wim Hennink Gert Storm Christien Oussoren 《European journal of pharmaceutical sciences》2003,20(4-5):419-427
The objective of this study was to assess the in vivo fate of poly(2-(dimethylamino)ethyl methacrylate) (pDMAEMA)-based polyplexes after intravenous administration into mice. Circulation kinetics and tissue distribution in terms of plasmid localization and transfection efficiency were assessed. To gain more insight into the observed biodistribution and gene expression profile, the interaction of pDMAEMA-based polyplexes with blood components (erythrocytes and albumin) was investigated in vitro. In the case of i.v. injection of positively charged polyplexes at a dose of 30 microg DNA most of the radioactivity was found in the lungs and the liver 60 min after injection. In the case of pDMAEMA/DNA polyplexes with a negative charge, uptake occurred mainly by the liver. Administration of positively charged complexes at a 30 microg DNA dose resulted in reporter gene expression primarily in the lungs. Injection of negatively charged complexes and naked plasmid did not result in luciferase expression in any of the organs examined. In vitro turbidity experiments showed the induction of a charge dependent aggregation process upon addition of albumin to the polyplexes pointing out to the involvement of aggregate formation in the dominant lung uptake of the positively charged polyplexes. Also, incubations of polyplexes after pre-incubation with a physiological concentration of albumin with washed erythrocytes confirmed that polyplexes induce the formation of extremely large structures. This paper underlines the need for the design of systems with reduced interaction with blood components to promote the delivery of DNA to target tissues outside the lungs. 相似文献
98.
基于人文理念的护理质量例会实践与体会 总被引:1,自引:0,他引:1
张育 《中国卫生质量管理》2010,17(5):13-14
建立以人文理念为核心的护理质量分析例会制度,每月召开门诊护士长、护士组长、护士代表例会,分析、讲评门诊护理服务中存在的问题,并提出改进方案,持续改进门诊护理服务质量。 相似文献
99.
目的 研究腹腔内注射三氧化二砷(arsenic trioxide,As2O3)对小鼠CO2气腹下肝癌H22转移的影响. 方法 昆明鼠40只(清洁级),中腹部穿刺置入1 mm套管针,自套管针注入1×106肿瘤细胞后,建立CO2气腹,压力8 mm Hg,时间30 min.术后随机分4组,每组10只,分别腹腔内注入生理盐水,1 ml;As2O3(2 mg/kg),1 ml;As2O3(4 mg/kg),1 ml;As2O3(4mg/kg)+肝素(10 U/ml),共1 ml.气腹后第3、7天测量肿瘤黏附因子(CD44)、血管内皮生长因子(vascular endothelial growth factor,VEGF)的变化;比较各组生存状态、腹围、体重变化及转移瘤直径.结果 气腹后第3、7天,与对照组相比,各As2O3组CD44、VEGF表达均明显降低(P<0.05).2个高剂量组的气腹后第3天VEGF、第7天CD44比低剂量组降低明显(P<0.05).4组戳口种植率分别为9/10、8/10、7/10、6/10,差异无显著性(x2=2.667,P=0.446). 结论 As2O3对CO2气腹腹腔镜肿瘤生长转移有抑制作用. 相似文献
100.
The enormous development in the field of molecular genetics during the last decades has lead to optimism concerning the possibilities for identifying the causes of multiple sclerosis (MS) through genetic studies. However, we have learned that dense mapping of large sample sets is needed, which only can be achieved through large collaborative studies. The contribution from each yet unidentified gene is probably weaker than that of the well established human leukocyte antigen association. The ultimate goal of the search for susceptibility genes in MS is to develop diagnostic tools and better treatments that can prevent or reduce the development of symptoms of this often devastating disease. 相似文献