全文获取类型
收费全文 | 6935篇 |
免费 | 337篇 |
国内免费 | 6篇 |
出版年
2022年 | 14篇 |
2021年 | 63篇 |
2020年 | 35篇 |
2019年 | 54篇 |
2018年 | 98篇 |
2017年 | 66篇 |
2016年 | 142篇 |
2015年 | 188篇 |
2014年 | 225篇 |
2013年 | 593篇 |
2012年 | 389篇 |
2011年 | 417篇 |
2010年 | 250篇 |
2009年 | 256篇 |
2008年 | 435篇 |
2007年 | 447篇 |
2006年 | 410篇 |
2005年 | 460篇 |
2004年 | 434篇 |
2003年 | 453篇 |
2002年 | 366篇 |
2001年 | 102篇 |
2000年 | 84篇 |
1999年 | 102篇 |
1998年 | 91篇 |
1997年 | 80篇 |
1996年 | 75篇 |
1995年 | 63篇 |
1994年 | 67篇 |
1993年 | 71篇 |
1992年 | 74篇 |
1991年 | 61篇 |
1990年 | 55篇 |
1989年 | 49篇 |
1988年 | 41篇 |
1987年 | 26篇 |
1986年 | 25篇 |
1985年 | 28篇 |
1984年 | 25篇 |
1983年 | 27篇 |
1982年 | 34篇 |
1981年 | 59篇 |
1980年 | 34篇 |
1979年 | 24篇 |
1978年 | 18篇 |
1977年 | 18篇 |
1976年 | 14篇 |
1975年 | 23篇 |
1974年 | 16篇 |
1973年 | 21篇 |
排序方式: 共有7278条查询结果,搜索用时 16 毫秒
1.
Kenji Tsuji Shinji KitamuraHirofumi Makino 《Biochemical and biophysical research communications》2014
The kidneys are exposed to hypoxic conditions during development. Hypoxia-inducible factor (HIF), an important mediator of the response to hypoxia, is believed to have an important role in development. However, the relationship between HIF and branching morphogenesis has not been elucidated clearly. 相似文献
2.
Takumi Higaki Natsumaro Kutsuna Kae Akita Hisako Takigawa-Imamura Kenji Yoshimura Takashi Miura 《PLoS computational biology》2016,12(4)
Plant leaf epidermal cells exhibit a jigsaw puzzle–like pattern that is generated by interdigitation of the cell wall during leaf development. The contribution of two ROP GTPases, ROP2 and ROP6, to the cytoskeletal dynamics that regulate epidermal cell wall interdigitation has already been examined; however, how interactions between these molecules result in pattern formation remains to be elucidated. Here, we propose a simple interface equation model that incorporates both the cell wall remodeling activity of ROP GTPases and the diffusible signaling molecules by which they are regulated. This model successfully reproduces pattern formation observed in vivo, and explains the counterintuitive experimental results of decreased cellulose production and increased thickness. Our model also reproduces the dynamics of three-way cell wall junctions. Therefore, this model provides a possible mechanism for cell wall interdigitation formation in vivo. 相似文献
3.
4.
5.
6.
Qi-Wen Fan Kenji Kadomatsu Kenji Uchimura Takashi Muramatsu 《Development, growth & differentiation》1998,40(3):277-286
Embigin and basigin are highly glycosylated transmembrane glycoproteins with two immunoglobulin domains and form a subgroup in the immunoglobulin superfamily. Previous studies have demonstrated the functional significance of these molecules. In the present study, in situ hybridization analysis of their expression was performed during mouse embryogenesis. Embigin was strongly expressed in the endoderm during early postimplantation embryogenesis, and in the somite stage in the gut and visceral endoderm. Embryonic ectoderm and its derivative tissues weakly to moderately expressed this molecule. From day 10 to 15 of gestation, no embigin signal was detected. Basigin was more broadly expressed. During the organogenesis period, basigin was expressed in various epithelial tissues, brain ventricles, the spinal cord and dorsal root ganglion. The modes of expression of these two proteins throughout the egg cylinder stage correlated with the expression of the carbohydrate markers that they carry; embigin with Dolichos biflorus agglutinin binding sites and basigin with Lex antigen and more closely with fucosyltransferase IV, which forms the antigenic epitope. These findings imply that proteins with specific carbohydrate epitopes play roles in early postimplantation embryogenesis. 相似文献
7.
8.
Cell walls were isolated by sonic disruption of log-phase cells of Clostridium botulinum type A strain 190L and purified by treatment with sodium dodecyl sulfate (SDS) followed by digestion with proteases. Electron microscopy revealed that the cell walls thus obtained were free of both cytoplasmic membrane and cytoplasmic fragments. The purified cell wall contained 8.7% total nitrogen, 15.0% total hexosamines, 22.4% reducing groups, 8.3% carbohydrate, and 3.1% glucose. The content of total phosphorus was very low (0.02%), and therefore it was expected that teichoic acid might be absent in the cell wall. The wall peptidoglycan contained glutamic acid, alanine, diaminopimelic acid, glucosamine and muramic acid in the molar ratios of 1.00:1.85:0:85:1.06:0.67. A low amount of galactosamine was also present, but no other amino acids were found in significant quantities. The SDS-treated cell walls were not attacked by lysozyme, but after extraction with hot formamide they were completely dissolved by the enzyme and released reducing groups. The lysozyme digest was separated into two constituents, the saccharide moiety and the peptide moiety on Sephadex G-50. 相似文献
9.
10.
Y Aoyagi I Tasaki J Okumura T Muramatsu 《Comparative biochemistry and physiology. A, Comparative physiology》1988,89(3):433-436
1. Effect of low ambient temperature on protein turnover in the liver and whole body was investigated in chicks together with the contribution of protein synthesis to the total heat production. 2. Both protein synthesis and degradation in the whole body were increased, the latter to a larger extent, at low ambient temperature (LT, 22 degrees C) compared with adequate temperature (AT, 30 degrees C). Liver protein synthesis was not significantly altered by the temperature treatment. 3. The total heat production of LT group was as high as 160% of the AT group. 4. The increased heat production due to enhanced whole-body protein synthesis accounted for only 1.4% of the heat increment in thermogenesis at low ambient temperature, suggesting that protein synthesis would contribute little, if any, to cold-induced thermogenesis in chicks. 相似文献