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   5455篇
  免费   367篇
  国内免费   413篇
  2024年   7篇
  2023年   77篇
  2022年   187篇
  2021年   288篇
  2020年   176篇
  2019年   221篇
  2018年   218篇
  2017年   174篇
  2016年   247篇
  2015年   312篇
  2014年   403篇
  2013年   438篇
  2012年   504篇
  2011年   431篇
  2010年   270篇
  2009年   251篇
  2008年   272篇
  2007年   198篇
  2006年   186篇
  2005年   190篇
  2004年   173篇
  2003年   161篇
  2002年   117篇
  2001年   124篇
  2000年   85篇
  1999年   105篇
  1998年   54篇
  1997年   37篇
  1996年   40篇
  1995年   35篇
  1994年   30篇
  1993年   18篇
  1992年   28篇
  1991年   23篇
  1990年   34篇
  1989年   8篇
  1988年   17篇
  1987年   12篇
  1986年   9篇
  1985年   8篇
  1984年   10篇
  1983年   8篇
  1982年   7篇
  1981年   5篇
  1980年   6篇
  1979年   3篇
  1978年   3篇
  1977年   3篇
  1975年   6篇
  1974年   3篇
排序方式: 共有6235条查询结果,搜索用时 31 毫秒
81.
Chen  Chong-Juan  Liu  Xue-Yan  Wang  Xian-Wei  Hu  Chao-Chen  Xu  Shi-Qi  Mao  Rong  Bu  Zhao-Jun  Fang  Yun-Ting  Koba  Keisuke 《Plant and Soil》2021,467(1-2):345-357
Plant and Soil - Plant carbon (C), nitrogen (N), phosphorus (P) levels and their stoichiometry and N uptake strategies are important aspects influencing vegetation composition and C dynamics in...  相似文献   
82.
83.
Shi  Yu  Mao  Xudong  Cai  Mingcheng  Hu  Shenqiang  Lai  Xiulan  Chen  Shiyi  Jia  Xianbo  Wang  Jie  Lai  Songjia 《Molecular and cellular biochemistry》2021,476(1):425-433
Molecular and Cellular Biochemistry - Skeletal muscle satellite cells (SMSCs), also known as a multipotential stem cell population, play a crucial role during muscle growth and regeneration. In...  相似文献   
84.
Wu  Ying  Jiang  Lisha  Zhang  Lingling  Liu  Xia  Yan  Lina  Luan  Ting  Rui  Can  Mao  Zhiyuan  Fan  Chong  Liu  Yu  Li  Ping  Zeng  Xin 《Mycopathologia》2021,186(2):177-188
Mycopathologia - Vulvovaginal candidiasis (VVC) caused by Candida spp. affects 70–75% of women at least once during their lives. We aim to elucidate the potential mechanism of VVC and...  相似文献   
85.
Wang  Yue  Su  Shengnan  Chen  Guogang  Mao  Huijuan  Jiang  Ying 《Journal of Plant Growth Regulation》2021,40(3):1152-1165

Cuticular wax is an important factor that affects storage quality of fruits and vegetables. Previous studies have shown that cuticular wax of pears changes significantly during storage, whereas there are few studies on the effects of different storage methods on the wax changes and the relationship with storage quality. Cuticular wax of Korla pear stored using different methods, was measured to analyze its total wax content, chemical compositions and their relationship with storage quality. At the end of storage, the highest cuticular wax content was observed in controlled atmosphere (CA) storage and the lowest in room temperature storage. The substances of the primary components with higher contents were nonacosane, (E, E)-ɑ-farnesene, dodecan-1-ol, 1,1-dimethoxynonane, nonanal, palmitic acid, and oleic acid. Total wax content, olefins and fatty acids were most significantly with the storage quality, followed by alkanes and esters. Moreover, total wax content, wax composition and weight loss were closely related to postharvest senescence. Overall, an understanding of variations in the cuticular wax under different storage methods could provide theoretical basis for further study on the storage and preservation technology of pears.

  相似文献   
86.
87.
Yang  Jing  Xun  HongWei  Niu  Lu  He  Hongli  Cheng  Yunqing  Zhong  Xiaofang  Zhao  Qianqian  Xing  Guojie  Liu  Jianfeng  Yang  Xiangdong 《Transgenic research》2021,30(5):675-686
Transgenic Research - Soybean seeds are an ideal host for the production of recombinant proteins because of their high content of proteins, long-term stability of seed proteins under ambient...  相似文献   
88.
光免疫治疗是一种新兴的肿瘤靶向光疗手段,它将单克隆抗体的肿瘤特异性与光吸收剂的光毒性相结合,可以快速且极具免疫原选择性地诱导靶肿瘤细胞的死亡。由于靶向性强,光免疫治疗的副作用小。而且因为该疗法诱导的免疫原性死亡会引起垂死肿瘤细胞周围未成熟树突状细胞的快速成熟,继而将肿瘤抗原提呈给CD8+T细胞,导致治疗后CD8+T细胞的激活和增殖,增强宿主抗肿瘤免疫反应。不仅如此,光免疫治疗还能通过增强纳米药物的肿瘤组织穿透性而提高疗效。鉴于光免疫治疗的优良应用前景,文中从其免疫激活机制、超级高渗透长滞留效应、新进展与联合治疗等方面进行综述,旨在为其深入研究和临床转化提供参考。  相似文献   
89.
He  Lingge  Zhang  Wenjie  Yang  Shuangyu  Meng  Wenting  Dou  Xia  Liu  Jianfeng  Liu  Yuanwei  Li  Haiyue  Jin  Tianbo 《Biochemical genetics》2021,59(3):697-713

The expression of IL-2RA and IL-2RB was correlated with breast cancer (BC) progression. However, there is no literature investigating the association of IL-2RA and IL-2RB polymorphisms with BC predisposition among Chinese Han Women. Seven SNPs in IL-2RA and IL-2RB were genotyped by Agena MassARRAY platform among 553 BC patients and 550 healthy controls. Odds ratios (OR) and 95% confidence interval (CI) adjusted for age were calculated for the effect of IL-2RA and IL-2RB variants on BC susceptibility. IL-2RA rs12722498 was a protective factor for BC occurrence (OR?=?0.70, p?=?0.019), especially in subjects with age?≤?52 years (OR?=?0.55, p?=?0.004). IL-2RA rs12569923 (OR?=?9.07, p?=?0.033), IL-2RB rs2281089 (OR?=?0.67, p?=?0.043) and rs9607418 (OR?=?0.59, p?=?0.012) were related to the incidence of estrogen receptor positive (ER?+) BC. IL-2RB rs3218264 (OR?=?1.38, p?=?0.010) and rs9607418 (OR?=?0.56, p?=?0.009) were associated with the risk of developing progesterone receptor positive (PR?+) BC. Rs2281089 (OR?=?1.54, p?=?0.012) and rs1573673 (OR?=?0.72, p?=?0.035) were correlated to Ki-67 level. Moreover, IL-2RB rs2281089 (OR?=?0.72, p?=?0.022) showed a reduced risk of BC metastasis, and IL-2RA rs12722498 (OR?=?0.54, p?=?0.030) had a lower frequency in BC patients with tumor size?>?2 cm. Our study identified the potential effect of genetic variations in IL-2RA and IL-2RB on BC susceptibility and/or BC clinicopathologic indicators among Chinese Han Women.

  相似文献   
90.
Long noncoding RNAs (lncRNAs) have been proven to exert important functions in the various biological processes of human cancers. It has been reported that lncRNA HNF1 homeobox A antisense RNA 1 (HNF1A‐AS1) was abnormally expressed and played a role in the initiation and development of various human cancers. In this study, we confirmed that the expression level of HNF1A‐AS1 was increased in glioma tissues and cells. Knockdown of HNF1A‐AS1 inhibited cell proliferation and promoted cell apoptosis in glioma. Then, we disclosed the downregulation of miR‐363‐3p in glioma tissues and cell lines. The interaction between HNF1A‐AS1 and miR‐363‐3p was identified in glioma cells. Furthermore, an inverse correlation between HNF1A‐AS1 and miR‐363‐3p was observed in glioma tissues. Afterwards, we recognized that MAP2K4 was a direct target of miR‐363‐3p. The expression of MAP2K4 was negatively correlated with miR‐363‐3p while positively related to HNF1A‐AS1 in glioma tissues. We also found the regulatory effect of HNF1A‐AS1 on the MAP2K4‐dependent JNK signaling pathway. All findings indicated that HNF1A‐AS1 induces the upregulation of MAP2K4 to activate the JNK signaling pathway to promote glioma cell growth by acting as a miR‐363‐3p sponge.  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