全文获取类型
收费全文 | 3759篇 |
免费 | 197篇 |
国内免费 | 1篇 |
出版年
2021年 | 43篇 |
2019年 | 27篇 |
2018年 | 49篇 |
2017年 | 40篇 |
2016年 | 55篇 |
2015年 | 99篇 |
2014年 | 115篇 |
2013年 | 279篇 |
2012年 | 182篇 |
2011年 | 196篇 |
2010年 | 138篇 |
2009年 | 126篇 |
2008年 | 172篇 |
2007年 | 151篇 |
2006年 | 144篇 |
2005年 | 144篇 |
2004年 | 152篇 |
2003年 | 144篇 |
2002年 | 177篇 |
2001年 | 141篇 |
2000年 | 141篇 |
1999年 | 122篇 |
1998年 | 58篇 |
1997年 | 27篇 |
1996年 | 37篇 |
1995年 | 28篇 |
1994年 | 21篇 |
1993年 | 29篇 |
1992年 | 80篇 |
1991年 | 76篇 |
1990年 | 72篇 |
1989年 | 65篇 |
1988年 | 60篇 |
1987年 | 63篇 |
1986年 | 49篇 |
1985年 | 52篇 |
1984年 | 32篇 |
1983年 | 33篇 |
1982年 | 25篇 |
1981年 | 21篇 |
1980年 | 21篇 |
1979年 | 34篇 |
1978年 | 20篇 |
1977年 | 25篇 |
1976年 | 25篇 |
1975年 | 23篇 |
1974年 | 28篇 |
1973年 | 15篇 |
1969年 | 18篇 |
1968年 | 17篇 |
排序方式: 共有3957条查询结果,搜索用时 62 毫秒
221.
222.
Yasunori Sugiyama Sho Yamashita Yuuki Uezato Yukako Senga Syouichi Katayama Naoki Goshima Yasushi Shigeri Noriyuki Sueyoshi Isamu Kameshita 《Analytical biochemistry》2016
To analyze a variety of protein phosphatases, we developed phosphorylated TandeMBP (P-TandeMBP), in which two different mouse myelin basic protein isoforms were fused in tandem, as a protein phosphatase substrate. P-TandeMBP was prepared efficiently in four steps: (1) phosphorylation of TandeMBP by a protein kinase mixture (Ca2+/calmodulin-dependent protein kinase Iδ, casein kinase 1δ, and extracellular signal-regulated kinase 2); (2) precipitation of both P-TandeMBP and protein kinases to remove ATP, Pi, and ADP; (3) acid extraction of P-TandeMBP with HCl to remove protein kinases; and (4) neutralization of the solution that contains P-TandeMBP with Tris. In combination with the malachite green assay, P-TandeMBP can be used to detect protein phosphatase activity without using radioactive materials. Moreover, P-TandeMBP served as an efficient substrate for PPM family phosphatases (PPM1A, PPM1B, PPM1D, PPM1F, PPM1G, PPM1H, PPM1K, and PPM1M) and PPP family phosphatase PP5. Various phosphatase activities were also detected with high sensitivity in gel filtration fractions from mouse brain using P-TandeMBP. These results indicate that P-TandeMBP might be a powerful tool for the detection of protein phosphatase activities. 相似文献
223.
224.
225.
Atsushi Yamashita Yukino Hatazawa Yuma Hirose Yusuke Ono 《Bioscience, biotechnology, and biochemistry》2016,80(8):1531-1535
Unloading stress, such as bed rest, inhibits the regenerative potential of skeletal muscles; however, the underlying mechanisms remain largely unknown. FOXO1 expression, which induces the upregulated expression of the cell cycle inhibitors p57 and Gadd45α, is known to be increased in the skeletal muscle under unloading conditions. However, there is no report addressing FOXO1-induced inhibition of myoblast proliferation. Therefore, we induced muscle injury by cardiotoxin in transgenic mice overexpressing FOXO1 in the skeletal muscle (FOXO1-Tg mice) and observed regeneration delay in skeletal muscle mass and cross-sectional area in FOXO1-Tg mice. Increased p57 and Gadd45α mRNA levels, and decreased proliferation capacity were observed in C2C12 myoblasts expressing a tamoxifen-inducible active form of FOXO1. These results suggest that decreased proliferation capacity of myoblasts by FOXO1 disrupts skeletal muscle regeneration under FOXO1-increased conditions, such as unloading. 相似文献
226.
227.
Amin Soltangheisi Paul J. A. Withers Paulo Sergio Pavinato Maurício Roberto Cherubin Raffaella Rossetto Janaina Braga Do Carmo Gustavo Casoni da Rocha Luiz Antonio Martinelli 《Global Change Biology Bioenergy》2019,11(12):1444-1455
Phosphorus (P) use in global food and bioenergy production needs to become more efficient and sustainable to reduce environmental impacts and conserve a finite and critical resource (Carpenter & Bennett, Environmental Research Letters, 2011, 6, 014009; Springmann et al., Nature, 2018, 562, 519). Sugarcane is one crop with a large P footprint because production is centered on P‐fixing soils with low P availability (Roy et al., Nature Plants, 2016, 2, 16043; Withers et al., Scientific Reports, 2018, 8, 2537). As global demand for processed sugar and bioethanol continues to increase, we advocate that improving P efficiency could become a key sustainability goal for the sugarcane industry. Here, we applied the 5R global P stewardship framework (Withers et al., Ambio, 2015, 44, 193) to identify more sustainable options to manage P in Brazilian sugarcane production. We show that current inputs of P fertilizer to the current crop area could be reduced by over 305 Gg, or 63%, over the next three decades by reducing unnecessary P fertilizer use, better utilization of recyclable bioresources and redesigning recommendation systems. Adoption of these 5R options would save the sugarcane industry in Brazil 528 US$ million and help safeguard global food and energy security. 相似文献
228.
229.
Takefumi Yamashita Eiichi Mizohata Satoru Nagatoishi Takahiro Watanabe Makoto Nakakido Hiroko Iwanari Yasuhiro Mochizuki Taisuke Nakayama Yuji Kado Yuki Yokota Hiroyoshi Matsumura Takeshi Kawamura Tatsuhiko Kodama Takao Hamakubo Tsuyoshi Inoue Hideaki Fujitani Kouhei Tsumoto 《Structure (London, England : 1993)》2019,27(3):519-527.e5
230.
Pelczar H Caulet S Thibier C Aubet G Poulhe R Vallianou I Yamashita M Andéol Y 《Development, growth & differentiation》2007,49(5):407-419
The M phase promoting factor (MPF) is a dimer composed of a catalytic Cdk1 subunit and a Cyclin B regulatory subunit. We have characterized a cDNA containing the entire coding sequence of an axolotl Cyclin B1 protein that is able to promote MPF activity when added to a fraction from prophase I oocytes that contains monomeric Cdk1. The axolotl cyclin B1 gene is expressed as a maternal mRNA in oocytes and early embryos. Its poly(A) tail length increases in metaphase II oocytes and then decreases regularly during the first embryonic cell cycles. Endogenous Cyclin B1 protein is first expressed during oocyte meiotic maturation. Its level oscillates after fertilization and is coordinated to the phosphorylation level of tyrosine 15 residue of Cdk1 (pTyr15), with both maxima preceding each cell division. As expected, when translated into microinjected oocytes, axolotl Cyclin B1 induces the resumption of meiosis. In electrically activated unfertilized eggs (UFE), Cyclin B1 and pTyr15 cyclic accumulations are observed with kinetics different from those of the early embryonic cycles. The axolotl embryo and UFE provide interesting in vivo comparative models for studying events controlling Cyclin B1 regulation during development. 相似文献