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   8557篇
  免费   609篇
  国内免费   90篇
耳鼻咽喉   142篇
儿科学   114篇
妇产科学   182篇
基础医学   1448篇
口腔科学   122篇
临床医学   739篇
内科学   1520篇
皮肤病学   232篇
神经病学   566篇
特种医学   370篇
外科学   1300篇
综合类   54篇
一般理论   2篇
预防医学   390篇
眼科学   156篇
药学   699篇
中国医学   135篇
肿瘤学   1085篇
  2023年   46篇
  2022年   34篇
  2021年   283篇
  2020年   177篇
  2019年   251篇
  2018年   318篇
  2017年   244篇
  2016年   327篇
  2015年   456篇
  2014年   503篇
  2013年   560篇
  2012年   803篇
  2011年   816篇
  2010年   484篇
  2009年   388篇
  2008年   591篇
  2007年   514篇
  2006年   430篇
  2005年   421篇
  2004年   328篇
  2003年   255篇
  2002年   230篇
  2001年   115篇
  2000年   110篇
  1999年   78篇
  1998年   35篇
  1997年   29篇
  1996年   26篇
  1995年   20篇
  1994年   21篇
  1993年   18篇
  1992年   24篇
  1991年   25篇
  1990年   30篇
  1989年   32篇
  1988年   25篇
  1987年   22篇
  1986年   23篇
  1985年   19篇
  1984年   13篇
  1983年   10篇
  1980年   6篇
  1979年   13篇
  1977年   10篇
  1976年   8篇
  1975年   9篇
  1974年   15篇
  1973年   12篇
  1971年   11篇
  1968年   6篇
排序方式: 共有9256条查询结果,搜索用时 18 毫秒
1.
PurposeTumor size and lymph node metastasis are important factors that contribute to the progression of breast cancer. We aimed to analyze the relationship between tumor size and lymph node metastasis molecular subtype and examine the effects of nodal metastasis on overall survival (OS).MethodsWe retrospectively reviewed the data of 16,552 patients who underwent breast surgery in Samsung Medical Center between 2000 and 2015. Information on tumor size (largest diameter of the invasive component), number of positive lymph nodes, and molecular subtype were obtained. We constructed a linear regression model to evaluate the relationship between tumor size and lymph node metastasis. To determine the effect of nodal metastasis on OS, we performed a Cox proportional regression analysis with Np/T (number of metastatic lymph nodes [n]/tumor size [cm]).ResultsThis study included 12,007 patients with a median follow-up of 62 months. The linear regression coefficients were 1.043 for luminal A, 1.024 for luminal B, 0.656 for HER2, and 0.435 for triple-negative breast cancer (TNBC) subtypes. No significant difference was observed in the coefficients between the luminal A and B subtypes (p = 0.797), while all other coefficients showed significant difference. After adjusting for other risk factors, the hazard ratio (HR) of Np/T for each subtype was significant for OS: luminal A (HR, 1.134; 95% confidence interval [CI], 1.097–1.171; p < 0.001), luminal B (HR, 1.049; 95% CI, 1.013–1.086; p = 0.007), HER2 (HR, 1.069; 95% CI, 1.014–1.126; p = 0.013), and TNBC (HR, 1.038; 95% CI, 1.01–1.067; p = 0.008).ConclusionThe incidence of lymph node metastasis differed according to molecular subtype. Luminal types have higher incidence of nodal metastasis than HER2 and TNBC. The HR of Np/T was highest in luminal A subtypes and lowest in TNBC subtypes.  相似文献   
2.
3.
Genetic and epigenetic alterations importantly contribute to the pathogenesis of lung cancer. In the study, we measured the frequency and distribution of molecular abnormalities of EGFR as well as the aberrant promoter methylations of BRCA1, MGMT, MLH1, and RASSF1A in Vietnamese lung adenocarcinomas. We investigated the association between genetic and epigenetic alteration, and between each abnormality with clinicopathologic parameters. Somatic EGFR mutation that was found in 49/139 (35.3%) lung adenocarcinomas showed a significant association with young age, female gender, and non-smokers. EGFR overexpression was identified in 82 tumors (59.0%) and statistical relationships with EGFR or BRCA1 methylation but not EGFR mutation. In addition, EGFR, BRCA1, MGMT, MLH1, and RASSF1A methylations were found in 33 (23.7%), 41 (29.5%), 46 (33.1%), 28 (20.1%), and 41 (29.5%) cases of a total of 139 lung adenocarcinomas, respectively. The RASSF1A methylation was found to be linked to the smoking habit. Methylations in MGMT and RASSF1A were also found to correlate with metastasis status. Furthermore, the distribution of EGFR mutation and that of BRCA1, MGMT or RASSF1A methylation were significantly exclusive in lung adenocarcinomas. The main finding of our study demonstrate that epigenetic abnormalities might play a critical role for the lung tumorigenesis in patients with smoking history and metastasis, and partly affect the predictive value of EGFR mutations through blocking expression due to promoter EGFR hypermethylation. Mutually exclusive distribution of genetic and epigenetic alterations reflects differently biological characteristics in the etiology of lung adenocarcinomas.  相似文献   
4.
5.
[Purpose] This study aimed to examine the correlation between health consciousness behavior and health-promoting behavior and quality of life, and to examine the factors affecting the quality of life for elders in South Korea. [Participants and Methods] This study is a cross-sectional study. A total of 191 respondents were selected through convenient sampling. Data were collected with a self-reported questionnaire from August 20 to September 20, 2019. [Results] Differences in health consciousness behavior and health-promoting behavior according to general characteristics and health behavior were as follows. Health consciousness behavior was significantly different according to gender, age, education, religion, occupation, exercise, smoking, drinking, health checkup. Health health-promoting behavior was significantly different according to gender, age, education, stress, health status, drinking. Quality of life was significantly different according to education, stress, health status, exercise, drinking. There was a positive correlation between health-promoting behavior and quality of life. Fifty three point zero percent of the variance in quality of life was explained by health-promoting behavior, health status and exercise. [Conclusion] The findings of this study may be useful in understanding the quality of life for elders and developing more specific programs about health-promoting behavior programs and health status and exercise management strategy is required.Key words: Health behavior, Health promotion, Quality of life  相似文献   
6.
7.
8.
9.
10.
Kim  Chae-Yong  Paek  Sun Ha  Nam  Do-hyun  Chang  Jong-Hee  Hong  Yong-Kil  Kim  Jeong Hoon  Kim  Oh Lyong  Kim  Se-Hyuk 《Journal of neuro-oncology》2020,146(3):399-406
Journal of Neuro-Oncology - Tumor treating fields (TTFields) are anti-mitotic, non-invasive loco-regional cancer therapy comprising low intensity, intermediate frequency alternating electric...  相似文献   
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