全文获取类型
收费全文 | 14990篇 |
免费 | 1150篇 |
国内免费 | 1106篇 |
专业分类
17246篇 |
出版年
2024年 | 32篇 |
2023年 | 175篇 |
2022年 | 454篇 |
2021年 | 821篇 |
2020年 | 487篇 |
2019年 | 596篇 |
2018年 | 625篇 |
2017年 | 522篇 |
2016年 | 620篇 |
2015年 | 892篇 |
2014年 | 1069篇 |
2013年 | 1200篇 |
2012年 | 1397篇 |
2011年 | 1251篇 |
2010年 | 774篇 |
2009年 | 683篇 |
2008年 | 751篇 |
2007年 | 624篇 |
2006年 | 605篇 |
2005年 | 486篇 |
2004年 | 429篇 |
2003年 | 330篇 |
2002年 | 344篇 |
2001年 | 312篇 |
2000年 | 254篇 |
1999年 | 249篇 |
1998年 | 165篇 |
1997年 | 130篇 |
1996年 | 133篇 |
1995年 | 125篇 |
1994年 | 138篇 |
1993年 | 92篇 |
1992年 | 96篇 |
1991年 | 70篇 |
1990年 | 66篇 |
1989年 | 58篇 |
1988年 | 56篇 |
1987年 | 31篇 |
1986年 | 33篇 |
1985年 | 19篇 |
1984年 | 23篇 |
1983年 | 12篇 |
1982年 | 8篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1933年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
821.
Shan Song Duojun Qiu Yonghong Shi Shuai Wang Xinbo Zhou Nan Chen Jinying Wei Ming Wu Haijiang Wu Huijun Duan 《Journal of cellular physiology》2019,234(9):16485-16502
Thioredoxin-interacting protein (TXNIP) is induced by high glucose (HG), whereupon it acts to inhibit thioredoxin, thereby promoting oxidative stress. We have found that TXNIP knockdown in human renal tubular cells helped prevent the epithelial-to-mesenchymal transition (EMT). Here, we studied the potential effect of TXNIP on podocyte phenotypic alterations in diabetic nephropathy (DN) in vivo and in vitro. In conditionally immortalized mouse podocytes under HG conditions, knocking down TXNIP disrupted EMT, reactive oxygen species (ROS) production, and mammalian target of rapamycin (mTOR) pathway activation. Further, Raptor short hairpin RNA (shRNA), Rictor shRNA, and mTOR specific inhibitor KU-0063794 were used to assess if the mTOR signal pathway is involved in HG-induced EMT in podocytes. We found that Raptor shRNA, Rictor shRNA, and KU-0063794 could all restrain HG-induced EMT and ROS production in podocytes. In addition, antioxidant Tempol or N-acetylcysteine presented a prohibitive effect on HG-induced EMT in podocytes. Streptozotocin was utilized to render equally diabetic in wild-type (WT) control and TXNIP −/− (TKO) mice. Diabetes did not increase levels of 24-hr urinary protein, serum creatinine, blood urea nitrogen, and triglyceride in TXNIP −/− mice. Podocyte phenotypic alterations and podocyte loss were detected in WT but not in TKO diabetic mice. Oxidative stress was also suppressed in diabetic TKO mice relative to WT controls. Also, TXNIP deficiency suppresses the activation of mTOR in glomeruli of streptozotocin-induced diabetic mice. Moreover, TXNIP expression, mTOR activation, Nox1, and Nox4 could be detected in renal biopsy tissues of patients with DN. This suggests that decreased TXNIP could ameliorate phenotypic alterations of podocytes via inhibition of mTOR in DN, highlighting TXNIP as a promising therapeutic target. 相似文献
822.
823.
Zhang Xiaonan Lu Yufang Yang Ting Kronzucker Herbert J. Shi Weiming 《Plant and Soil》2019,441(1-2):253-259
Plant and Soil - Depending on the availability and stoichiometry of nutrients in soil, microbes and plants can compete for the same resources. In this study we aimed to test how microbial nutrient... 相似文献
824.
825.
Xu Chen Lei Shi Yuqin Chen Lu Zhu Dasheng Zhang Shi Xiao Asaph Aharoni Jianxin Shi Jie Xu 《Plant, cell & environment》2019,42(4):1190-1204
Sepals play important roles in protecting inner floral organs from various stresses and in guaranteeing timely flower opening. However, the exact role of sepals in coordinating interior and exterior signals remains elusive. In this study, we functionally characterized a heat shock protein gene, Arabidopsis HSP70‐16, in flower opening and mild heat stress response, using combined genetics with anatomic, physiological, chemical, and molecular analyses. We showed that HSP70‐16 is required for flower opening and mild heat response. Mutation of HSP70‐16 led to a significant reduction in seed setting rate under 22°C, which was more severe at 27°C. Mutation of HSP70‐16 also caused postgenital fusion at overlapping tips of two lateral sepals, leading to failed flower opening, abnormal floral organ formation, and impaired fertilization and seed setting. Chemical and anatomic analyses confirmed specific chemical and morphological changes of cuticle property in mutant lateral sepals, and qRT‐PCR data indicated that expression levels of different sets of cuticle regulatory and biosynthetic genes were altered in mutants grown at both 22°C and 27°C temperatures. This study provides a link between thermal and developmental perception signals and expands the understanding of the roles of sepal in plant development and heat response. 相似文献
826.
827.
Liu Shuai Li Su Fan Xiao-Yang Yuan Guo-Di Hu Tao Shi Xian-Meng Huang Jun-Biao Pu Xiao-Yan Wu Chuan-Sheng 《Photosynthesis research》2019,141(2):245-257
Photosynthesis Research - Chlorophyll content in lichens is routinely used as an accurate indicator of lichen vigor, interspecific differences, and the effect of site-related environmental... 相似文献
828.
Dan Liu Xiaoxi Li Xintian Chen Yu Sun Anqun Tang Zhongwei Li Junnian Zheng Ming Shi 《生物化学与生物物理学报:癌评论》2019,1871(1):20-28
The treatment of cancer has made great progress. However, drug resistance remains problematic. Multiple physiologic processes of tumor development can be dominated by central and sympathetic nervous systems. The interactions between the nervous system, immune system, and tumor occur consistently and dynamically. Recent evidence suggests that nerves and neural signals are intimately involved in the development of resistance to cancer therapies. In this review, we will provide an overview of the recent progress in this rapidly growing area and discuss the potential new strategies for targeting the neural signaling pathway to improve the effectiveness of chemotherapies, targeted therapies, and immunotherapies. 相似文献
829.
Long Huiping Zhong Gang Wang Chengzhi Zhang Jian Zhang Yueling Luo Jinglian Shi Shengliang 《Neurochemical research》2019,44(8):1830-1839
Neurochemical Research - The pathogenesis of late-onset Alzheimer's disease (LOAD) mainly involves abnormal accumulation of extracellular β-amyloid (Aβ) and the consequent neurotoxic... 相似文献
830.
Pseudomonas amygdali pv. lachrymans is currently of important plant pathogenic bacteria that causes cucumber angular leaf spot worldwide. The pathogen has been studied for its roles in pathogenicity and plant inheritance resistance. To further delineate traits critical to virulence, invasion and survival in the phyllosphere, we reported the first complete genome of P. amygdali pv. lachrymans NM002. Analysis of the whole genome in comparison with three closely-related representative pathovars of P. syringae identified the conservation of virulence genes, including flagella and chemotaxis, quorum-sensing systems, two-component systems, and lipopolysaccharide and antiphagocytosis. It also revealed differences of invasion determinants, such as type III effectors, phytotoxin (coronatine, syringomycin and phaseolotoxin) and cell wall-degrading enzyme, which may contribute to infectivity. The aim of this study was to derive genomic information that would reveal the probable molecular mechanisms underlying the virulence, infectivity and provide a better understanding of the pathogenesis of the P. syringae pathovars. 相似文献