全文获取类型
收费全文 | 32300篇 |
免费 | 1957篇 |
国内免费 | 4770篇 |
出版年
2024年 | 52篇 |
2023年 | 505篇 |
2022年 | 634篇 |
2021年 | 988篇 |
2020年 | 876篇 |
2019年 | 1139篇 |
2018年 | 907篇 |
2017年 | 863篇 |
2016年 | 910篇 |
2015年 | 1132篇 |
2014年 | 1529篇 |
2013年 | 2085篇 |
2012年 | 1496篇 |
2011年 | 1526篇 |
2010年 | 1329篇 |
2009年 | 1625篇 |
2008年 | 1786篇 |
2007年 | 1933篇 |
2006年 | 1972篇 |
2005年 | 1827篇 |
2004年 | 1693篇 |
2003年 | 1588篇 |
2002年 | 1461篇 |
2001年 | 1195篇 |
2000年 | 994篇 |
1999年 | 924篇 |
1998年 | 810篇 |
1997年 | 701篇 |
1996年 | 681篇 |
1995年 | 654篇 |
1994年 | 616篇 |
1993年 | 435篇 |
1992年 | 382篇 |
1991年 | 319篇 |
1990年 | 268篇 |
1989年 | 187篇 |
1988年 | 207篇 |
1987年 | 183篇 |
1986年 | 134篇 |
1985年 | 119篇 |
1984年 | 104篇 |
1983年 | 49篇 |
1982年 | 64篇 |
1981年 | 32篇 |
1980年 | 36篇 |
1979年 | 23篇 |
1978年 | 17篇 |
1977年 | 9篇 |
1976年 | 16篇 |
1950年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
901.
902.
Amina‐Zahra Mouhoumed Ya‐Ni Mou Sen‐Miao Tong Sheng‐Hua Ying Ming‐Guang Feng 《Cellular microbiology》2020,22(10)
FK506‐sensitive proline rotamases (FPRs), also known as FK506‐binding proteins (FKBPs), can mediate immunosuppressive drug resistance in budding yeast but their physiological roles in filamentous fungi remain opaque. Here, we report that three FPRs (cytosolic/nuclear 12.15‐kD Fpr1, membrane‐associated 14.78‐kD Fpr2 and nuclear 50.43‐kD Fpr3) are all equally essential for cellular Ca2+ homeostasis and contribute significantly to calcineurin activity at different levels in the insect‐pathogenic fungus Beauveria bassiana although the deletion of fpr1 alone conferred resistance to FK506. Radial growth, conidiation, conidial viability and virulence were less compromised in the absence of fpr1 or fpr2 than in the absence of fpr3, which abolished almost all growth on scant media and reduced growth moderately on rich media. The Δfpr3 mutant was more sensitive to Na+, K+, Mn2+, Ca2+, Cu2+, metal chelate, heat shock and UVB irradiation than was Δfpr2 while both mutants were equally sensitive to Zn2+, Mg2+, Fe2+, H2O2 and cell wall‐perturbing agents. In contrast, the Δfpr1 mutant was less sensitive to fewer stress cues. Most of 32 examined genes involved in DNA damage repair, Na+/K+ detoxification or osmotolerance and Ca2+ homeostasis were downregulated sharply in Δfpr2 and Δfpr3 but rarely so affected in Δfpr1, coinciding well with their phenotypic changes. These findings uncover important, but differential, roles of three FPRs in the fungal adaptation to insect host and environment and provide novel insight into their essential roles in calcium signalling pathway. 相似文献
903.
Mutations in MIR396e and MIR396f increase grain size and modulate shoot architecture in rice 总被引:1,自引:0,他引:1
Chunbo Miao Dong Wang Reqing He Shenkui Liu Jian‐Kang Zhu 《Plant biotechnology journal》2020,18(2):491-501
Grain size and plant architecture are critical factors determining crop productivity. Here, we performed gene editing of the MIR396 gene family in rice and found that MIR396e and MIR396f are two important regulators of grain size and plant architecture. mir396ef mutations can increase grain yield by increasing grain size. In addition, mir396ef mutations resulted in an altered plant architecture, with lengthened leaves but shortened internodes, especially the uppermost internode. Our research suggests that mir396ef mutations promote leaf elongation by increasing the level of a gibberellin (GA) precursor, mevalonic acid, which subsequently promotes GA biosynthesis. However, internode elongation in mir396ef mutants appears to be suppressed via reduced CYP96B4 expression but not via the GA pathway. This research provides candidate gene‐editing targets to breed elite rice varieties. 相似文献
904.
905.
Yingfan Cai Xiaoyan Cai Qinglian Wang Ping Wang Yu Zhang Chaowei Cai Yanchao Xu Kunbo Wang Zhongli Zhou Chenxiao Wang Shuaipeng Geng Bo Li Qi Dong Yuqing Hou Heng Wang Peng Ai Zhen Liu Feifei Yi Minshan Sun Guoyong An Jieru Cheng Yuanyuan Zhang Qian Shi Yuanhui Xie Xinying Shi Ying Chang Feifei Huang Yun Chen Shimiao Hong Lingyu Mi Quan Sun Lin Zhang Baoliang Zhou Renhai Peng Xiao Zhang Fang Liu 《Plant biotechnology journal》2020,18(3):814-828
906.
Nikkhil Velingkaar Volha Mezhnina Allan Poe Kuldeep Makwana Richa Tulsian Roman V. Kondratov 《Aging cell》2020,19(4)
Caloric restriction (CR) has positive effects on health and longevity. CR in mammals implements time‐restricted (TR) feeding, a short period of feeding followed by prolonged fasting. Periodic fasting, in the form of TR or mealtime, improves metabolism without reduction in caloric intake. In order to understand the relative contribution of reduced food intake and periodic fasting to the health benefits of CR, we compared physiological and metabolic changes induced by CR and TR (without reduced food intake) in mice. CR significantly reduced blood glucose and insulin around the clock, improved glucose tolerance, and increased insulin sensitivity (IS). TR reduced blood insulin and increased insulin sensitivity, but in contrast to CR, TR did not improve glucose homeostasis. Liver expression of circadian clock genes was affected by both diets while the mRNA expression of glucose metabolism genes was significantly induced by CR, and not by TR, which is in agreement with the minor effect of TR on glucose metabolism. Thus, periodic fasting contributes to some metabolic benefits of CR, but TR is metabolically different from CR. This difference might contribute to differential effects of CR and TR on longevity. 相似文献
907.
Pablo Ferreira das Chagas Mirella Baroni María Sol Brassesco Luiz Gonzaga Tone 《The journal of gene medicine》2020,22(1)
Musashi comprises an evolutionarily conserved family of RNA‐binding proteins (RBP) that regulate cell fate decisions during embryonic development and play key roles in the maintenance of self‐renewal and differentiation of stem cells and adult tissues. More recently, several studies have shown that any dysregulation of MSI1 and MSI2 can lead to cellular dysfunctions promoting tissue instability and tumorigenesis. Moreover, several reports have characterized many molecular interactions between members of the Musashi family with ligands and receptors of the signaling pathways responsible for controlling normal embryonic development: Notch, Transforming Growth Factor Beta (TGF‐β), Wingless (Wnt) and Hedgehog Signaling (Hh); all of which, when altered, are strongly associated with cancer onset and progression, especially in pediatric tumors. In this context, the present review aims to compile possible cross‐talks between Musashi proteins and members of the above cited molecular pathways for which dysregulation plays important roles during carcinogenesis and may be modulated by these RBP. 相似文献
908.
Yann Thierry Le Guen Tony Le Gall Patrick Midoux Philippe Gugan Serge Braun Tristan Montier 《The journal of gene medicine》2020,22(2)
Hydrodynamic limb vein injection is an in vivo locoregional gene delivery method. It consists of administrating a large volume of solution containing nucleic acid constructs in a limb with both blood inflow and outflow temporarily blocked using a tourniquet. The fast, high pressure delivery allows the musculature of the whole limb to be reached. The skeletal muscle is a tissue of choice for a variety of gene transfer applications, including gene therapy for Duchenne muscular dystrophy or other myopathies, as well as for the production of antibodies or other proteins with broad therapeutic effects. Hydrodynamic limb vein delivery has been evaluated with success in a large range of animal models. It has also proven to be safe and well‐tolerated in muscular dystrophy patients, thus supporting its translation to the clinic. However, some possible limitations may occur at different steps of the delivery process. Here, we have highlighted the interests, bottlenecks and potential improvements that could further optimize non‐viral gene transfer following hydrodynamic limb vein injection. 相似文献
909.