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   108097篇
  免费   8387篇
  国内免费   9076篇
  125560篇
  2024年   243篇
  2023年   1421篇
  2022年   3266篇
  2021年   5518篇
  2020年   3780篇
  2019年   4685篇
  2018年   4433篇
  2017年   3242篇
  2016年   4595篇
  2015年   6679篇
  2014年   7851篇
  2013年   8311篇
  2012年   9994篇
  2011年   8984篇
  2010年   5551篇
  2009年   4977篇
  2008年   5714篇
  2007年   5133篇
  2006年   4461篇
  2005年   3498篇
  2004年   2973篇
  2003年   2721篇
  2002年   2273篇
  2001年   1868篇
  2000年   1695篇
  1999年   1671篇
  1998年   1040篇
  1997年   1001篇
  1996年   943篇
  1995年   821篇
  1994年   788篇
  1993年   618篇
  1992年   818篇
  1991年   618篇
  1990年   466篇
  1989年   443篇
  1988年   354篇
  1987年   344篇
  1986年   266篇
  1985年   286篇
  1984年   156篇
  1983年   161篇
  1982年   99篇
  1981年   85篇
  1980年   60篇
  1979年   77篇
  1977年   59篇
  1975年   56篇
  1974年   52篇
  1973年   56篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
In the present study, we explored the clinical and immunological characteristics of 575 uterine corpus endometrial carcinoma (UCEC) samples obtained from The Cancer Genome Atlas (TCGA) using the ESTIMATE and CIBERSORT algorithms. First, Kaplan–Meier and univariate Cox regression analyses indicated that the immune cell score was a prognostic factor for overall survival (OS) and recurrence-free survival (RFS). Multivariate Cox regression analysis further revealed that the immune cell score was an independent prognostic factor for UCEC patients. Second, we investigated the correlation between the infiltration levels of 22 types of immune cells and the immune score. Survival analysis based on the 22 immune cell types showed that higher levels of regulatory T cell, activated NK cell, and follicular helper T-cell infiltration were associated with longer OS, while higher levels of CD8+ T cell and naive B-cell infiltration were associated with longer RFS. Next, we performed differential expression and prognosis analyses on 1534 immune-related genes and selected five from 14 candidate genes to construct a prognostic prediction model. The area under the receiver-operating characteristic (ROC) curve (AUC) for 3- and 5-year survival were 0.711 and 0.728, respectively. Further validation using a stage I–II subgroup showed similar results, presenting AUC values for 3- and five-year survival of 0.677 and 0.692, respectively. Taken together, the present study provides not only a deeper understanding of the relationship between UCEC and the immune landscape but also guidance for the future development of UCEC immunotherapy.  相似文献   
992.
Mu  Dan  Pan  Chenyang  Qi  Zehua  Qin  Huaguang  Li  Qin  Liang  Kexin  Rao  Yuchun  Sun  Tingzhe 《Plant Growth Regulation》2021,95(1):111-120
Plant Growth Regulation - The tea green leafhopper (Empoasca onukii Matsuda) is a severe pest for the tea plant (Camellia sinensis (L.) O. Ktze), which significantly reduces the tea yields and...  相似文献   
993.
Wang  Jing  Wen  Xuefa  Lyu  Sidan  Zhang  Xinyu  Li  Shenggong  Guo  Qingjun 《Plant and Soil》2021,460(1-2):609-623
Plant and Soil - Forest recovery from disturbance can alter soil nitrogen (N) status as a result of complex interactions in plant-soil system. The δ15N and δ18O are indicators that...  相似文献   
994.
995.
996.
997.
998.
999.
1000.

Sex dimorphism is ubiquitous in the animal kingdom and can be influenced by environmental factors. However, relatively little is known about how the degree and direction of sex difference vary with environmental factors, including food quality and temperature. With the spider mites from the family Tetranychidae as subjects, the sex difference of life-history traits in responses to host plant and temperature were determined in this meta-analytic review. Across the 42 studies on 26 spider mite species (N?=?8057 and 3922 for female and male mites, respectively), female spider mites showed longer developmental duration than the males in all except two species. The direction of sex difference in development was consistent regardless of temperature and host plant. The 16 spider mite species in 33 studies generally showed female-biased longevity, with an overall effect size of 0.6043 [95%CI = 0.4054–0.8031]. Host plant significantly influenced the sex difference in longevity, where the males lived longer than females below 22.5 ℃, but the reverse was true at higher and fluctuating temperature. Host plant also influenced the magnitude of sex difference in longevity, with females living longer than males when reared on herbs but not on trees. This study indicated that life-history traits are highly variable between sexes under temperature and host plant influence, highlighting that environmental conditions can significantly shape the direction and magnitude of sexual dimorphism of life-history traits.

  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