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   66527篇
  免费   4515篇
  国内免费   393篇
耳鼻咽喉   539篇
儿科学   1836篇
妇产科学   1524篇
基础医学   9383篇
口腔科学   1251篇
临床医学   6840篇
内科学   14938篇
皮肤病学   1099篇
神经病学   7566篇
特种医学   1810篇
外科学   7097篇
综合类   443篇
一般理论   61篇
预防医学   6646篇
眼科学   872篇
药学   4548篇
中国医学   153篇
肿瘤学   4829篇
  2024年   75篇
  2023年   778篇
  2022年   1412篇
  2021年   2689篇
  2020年   1683篇
  2019年   2262篇
  2018年   2648篇
  2017年   1801篇
  2016年   2019篇
  2015年   2244篇
  2014年   2792篇
  2013年   3563篇
  2012年   5700篇
  2011年   5676篇
  2010年   2957篇
  2009年   2615篇
  2008年   4150篇
  2007年   4201篇
  2006年   3900篇
  2005年   3760篇
  2004年   3366篇
  2003年   3000篇
  2002年   2661篇
  2001年   415篇
  2000年   365篇
  1999年   433篇
  1998年   567篇
  1997年   410篇
  1996年   324篇
  1995年   289篇
  1994年   226篇
  1993年   216篇
  1992年   212篇
  1991年   162篇
  1990年   143篇
  1989年   121篇
  1988年   118篇
  1987年   99篇
  1986年   103篇
  1985年   88篇
  1984年   99篇
  1983年   84篇
  1982年   70篇
  1981年   76篇
  1980年   62篇
  1979年   35篇
  1978年   34篇
  1977年   35篇
  1973年   32篇
  1970年   25篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
Several tools to facilitate the risk assessment and management of manufactured nanomaterials (MN) have been developed. Most of them require input data on physicochemical properties, toxicity and scenario-specific exposure information. However, such data are yet not readily available, and tools that can handle data gaps in a structured way to ensure transparent risk analysis for industrial and regulatory decision making are needed. This paper proposes such a quantitative risk prioritisation tool, based on a multi-criteria decision analysis algorithm, which combines advanced exposure and dose-response modelling to calculate margins of exposure (MoE) for a number of MN in order to rank their occupational risks. We demonstrated the tool in a number of workplace exposure scenarios (ES) involving the production and handling of nanoscale titanium dioxide, zinc oxide (ZnO), silver and multi-walled carbon nanotubes. The results of this application demonstrated that bag/bin filling, manual un/loading and dumping of large amounts of dry powders led to high emissions, which resulted in high risk associated with these ES. The ZnO MN revealed considerable hazard potential in vivo, which significantly influenced the risk prioritisation results. In order to study how variations in the input data affect our results, we performed probabilistic Monte Carlo sensitivity/uncertainty analysis, which demonstrated that the performance of the proposed model is stable against changes in the exposure and hazard input variables.  相似文献   
15.
16.
17.

Objective

To explore from a gender perspective the association with subjective health of the interaction between education and household arrangements within the framework of social determinants of health placed at the micro and mezzo levels.

Methods

The data comes from the Spanish sample of the European Union Statistics on Income and Living Conditions for 2014. Independent logistic regression models for men and women were run to analyze the association with subjective health of the interaction between education and household arrangements. An additive model was run to assess possible advantages over the interaction approach.

Results

The interaction models show a lower or even no significant effect on health of household arrangements usually negatively associated with health among individuals with high education, displaying specific patterns according to sex.

Conclusions

Health profiles of women and men are more precisely drawn if both social determinants of health are combined. Among the women, the important role was confirmed of both social determinants of health in understanding their health inequalities. Among the men, mainly those with low educational achievement, the interaction revealed that the household was a more meaningful social determinant of health. This could enable the definition of more efficient public policies to reduce health and gender inequalities.  相似文献   
18.

Background

Radium 223 was introduced for metastatic castration-resistant prostate cancer based on the results of a randomized controlled trial showing risk reduction for death and skeletal events. Our aim was to evaluate the outcome of patients receiving radium 223 in a real-world setting.

Patients and Methods

We conducted a multicenter retrospective analysis in the Triveneto region of Italy.

Results

One hundred fifty-eight patients received radium 223 in our region. After a median follow-up of 9.5 months, 75 patients died. The median overall survival (OS) was 14.2 months, and the median progression-free survival (PFS) was 6.2 months. Seventy-one (45%) patients achieved progression as best response. Thirty-seven (23%) patients stopped the treatment early because of progression. Eastern Cooperative Oncology Group performance status was prognostic for OS (18.4 vs. 12.3 vs. 7.5 months; 0 vs. 1, P = .0062; 0 vs. 2, P = .0002), whereas previous prostatectomy or docetaxel exposure were not. A neutrophil to lymphocytes ratio ≥ 3 significantly impacted OS (18.1 vs. 9.7 months; P < .001) and slightly impacted PFS (6.6 vs. 5.6 months; P = .05). Patients with a baseline alkaline phosphatase (ALP) value ≥ 220 U/L had worse OS and PFS (24.1 vs. 10.5 months; 7.2 vs. 5.5 months; P < .001). Patients with changes in ALP value achieved better OS (P = .029) and PFS (P = .002). There was no difference according to the line of therapy (0 vs. ≥ 1; P = .490). The main grade 3/4 toxicities were anemia, asthenia, and thrombocytopenia.

Conclusion

This large real-world report confirms comparable OS and PFS data when compared with the pivotal study, as well as the predictive role of ALP and neutrophil to lymphocytes ratio. The definition of the optimal position of radium 223 in the treatment of metastatic castration-resistant prostate cancer has still to be defined.  相似文献   
19.
20.
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