全文获取类型
收费全文 | 546篇 |
免费 | 42篇 |
专业分类
588篇 |
出版年
2023年 | 7篇 |
2021年 | 13篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2016年 | 10篇 |
2015年 | 15篇 |
2014年 | 26篇 |
2013年 | 40篇 |
2012年 | 34篇 |
2011年 | 23篇 |
2010年 | 14篇 |
2009年 | 21篇 |
2008年 | 28篇 |
2007年 | 28篇 |
2006年 | 34篇 |
2005年 | 33篇 |
2004年 | 27篇 |
2003年 | 21篇 |
2002年 | 27篇 |
2001年 | 13篇 |
2000年 | 16篇 |
1999年 | 7篇 |
1998年 | 12篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 12篇 |
1984年 | 2篇 |
1983年 | 7篇 |
1982年 | 3篇 |
1980年 | 2篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1966年 | 4篇 |
1965年 | 2篇 |
1964年 | 2篇 |
排序方式: 共有588条查询结果,搜索用时 0 毫秒
91.
Akihiro Nita Akinobu Matsumoto Ronghao Tang Chisa Shiraishi Kazuya Ichihara Daisuke Saito Mikita Suyama Tomoharu Yasuda Gaku Tsuji Masutaka Furue Bumpei Katayama Toshiyuki Ozawa Teruasa Murata Teruki Dainichi Kenji Kabashima Atsushi Hatano Masaki Matsumoto Keiichi I. Nakayama 《PLoS genetics》2021,17(8)
92.
Takuhiro Sonoyama Kazutoshi Miyashita Kwijun Park Naofumi Oyamada Daisuke Taura Megumi Inuzuka Yasutomo Fukunaga Masakatsu Sone Kazuwa Nakao 《FEBS letters》2009,583(12):2067-2070
Anti-fibrotic and organ protective effects of brain natriuretic peptide (BNP) have been reported. In this study, effects of BNP on liver fibrosis were examined in the carbon tetrachloride (CCl4)-induced liver fibrosis model using BNP-transgenic (Tg) and wild-type (WT) mice. Twice-a-week intraperitoneal injections of CCl4 for 8 weeks resulted in massive liver fibrosis, augmented transforming growth factor (TGF)-β1 and type I procollagen α1 chain (Col1a1) mRNA expression, and the hepatic stellate cell (HSC) activation in WT mice, all of which were significantly suppressed in Tg mice. These observations indicate that BNP inhibits liver fibrosis by attenuating the activation of HSCs. 相似文献
93.
Carlos Quijano Pavel Tomancak Jesus Lopez-Marti Mikita Suyama Peer Bork Marco Milan David Torrents Miguel Manzanares 《Genome biology》2009,9(12):R176
Background
The physical organization and chromosomal localization of genes within genomes is known to play an important role in their function. Most genes arise by duplication and move along the genome by random shuffling of DNA segments. Higher order structuring of the genome occurs in eukaryotes, where groups of physically linked genes are co-expressed. However, the contribution of gene duplication to gene order has not been analyzed in detail, as it is believed that co-expression due to recent duplicates would obscure other domains of co-expression. 相似文献94.
95.
96.
Kenji Takahashi Naofumi Kamimura Shojiro Hishiyama Hirofumi Hara Daisuke Kasai Yoshihiro Katayama Masao Fukuda Shinya Kajita Eiji Masai 《Biodegradation》2014,25(5):735-745
Sphingobium sp. strain SYK-6 is capable of degrading various lignin-derived biaryls. We determined the catabolic pathway of a phenylcoumaran-type compound, dehydrodiconiferyl alcohol (DCA) in SYK-6, and identified some of the DCA catabolism genes. In SYK-6 cells, the alcohol group of DCA was oxidized to the carboxyl group, first at the B-ring side chain and then at the A-ring side chain. The resultant metabolite was degraded to 5-formylferulate and vanillin through the decarboxylation and the Cα–Cβ cleavage of the A-ring side chain. Based on the DCA catabolic pathway, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) genes are thought to be involved in the conversion of DCA into an aldehyde intermediate (DCA-L) and the conversion of DCA-L into a carboxylic acid intermediate (DCA-C), respectively. SLG_05620 and SLG_24930, which belong to quinohemoprotein ADH and aryl ADH, respectively, were isolated as the genes responsible for the oxidation of DCA. In addition to these genes, multiple genes similar to SLG_05620 and SLG_24930 were found to confer DCA oxidation activities on Escherichia coli cells. In order to identify the DCA-L dehydrogenase genes, the DCA-L oxidation activities of the SYK-6 gene products of putative twenty-one ALDH genes were examined. Significant activities were observed in the four ALDH gene products, including the SLG_27910 product, which showed the highest activity. The disruption of SLG_27910 caused a decreased conversion of DCA-L, suggesting that SLG_27910 plays an important role in the DCA-L oxidation. In conclusion, no specific gene seems to be solely responsible for the conversion of DCA and DCA-L, however, the multiple genes encoding quinohemoprotein ADH and aryl ADH genes, and four ALDH genes are probably involved in the conversion processes. 相似文献
97.
Keiko Ueno-Shuto Kosuke Kato Yukihiro Tasaki Miki Sato Keizo Sato Yuji Uchida Hiromichi Sakai Tomomi Ono Mary Ann Suico Kazunori Mitsutake Naofumi Tokutomi Hirofumi Kai Tsuyoshi Shuto 《The Journal of biological chemistry》2014,289(26):18097-18109
Single immunoglobulin interleukin-1 receptor-related molecule (SIGIRR) is one of the immunoglobulin-like membrane proteins that is crucial for negative regulation of toll-like receptor 4 (TLR4) and interleukin-1 receptor. Despite the importance of understanding its expression and function, knowledge is limited on the regulatory mechanism in the epithelial tissues, such as the liver, lung, and gut, where its predominant expression is originally described. Here, we found expression of SIGIRR in non-epithelial innate immune cells, including primary peripheral blood monocytes, polymorphonuclear neutrophils, monocytic RAW264 cells, and neutrophilic-differentiated HL-60 cells. Consistent with previous findings in epithelial tissues, SIGIRR gene and protein expression were also down-regulated by LPS treatment in a time-dependent manner in primary blood monocytes and polymorphonuclear neutrophils. A reduction was also observed in RAW264 and differentiated HL-60 cells. Notably, exogenous introduction of the dominant negative form of TLR4 and siRNA of p38 resulted in inhibition of LPS-induced SIGIRR down-regulation, whereas treatment with p38 activator anisomycin showed a dose-dependent decrease in SIGIRR expression, suggesting TLR4-p38 signal as a critical pathway for LPS-induced SIGIRR down-regulation. Finally, reporter gene and chromatin immunoprecipitation assays demonstrated that Sp1 is a key factor that directly binds to the proximal promoter of SIGIRR gene and consequently regulates basal SIGIRR expression, which is negatively regulated by the LPS-dependent TLR4-p38 pathway. In summary, the data precisely demonstrate how LPS down-regulates SIGIRR expression and provide a role of LPS signal that counteracts Sp1-dependent basal promoter activation of SIGIRR gene via TLR4-p38 pathway in non-epithelial innate immune cells. 相似文献
98.
DNA was isolated from a mitochondrial fraction of each of the following plant materials: Mung bean (Phaseolus aureus) etiolated hypocotyl; turnip (Brassica rapa) root; sweet potato (Ipomoea batatas) root; and onion (Allium cepa) bulb. It was found that all of these mitochondrial fractions contained DNA, the densities of which were identical (ρ=1.706 g·cm−3). An additional DNA (ρ=1.695) band found in the mitochondrial fraction of Brassica rapa, was identical to DNA separately isolated from the chloroplast-rich fraction. The origin of the second DNA from Allium mitochondrial fraction was not identified.
Contrary to the identity of the mitochondrial DNA, DNA from nuclear fractions differed not only with each other but from the corresponding mitochondrial DNA.
DNA from Phaseolus and Brassica mitochondria showed the hyperchromicity characteristic of double stranded, native DNA upon heating; Tm's in 0.0195 Na+ were the same; 72.0°. The amount of DNA within the mitochondrion of Phaseolus was estimated to be 5.0 × 10−10 μg; this estimate was made by isolating the mitochondrial DNA concomitantly with the known amount of added 15N2H B. subtilis DNA (ρ=1.740). Approximately the same amount of DNA was present in the mitochondrion of Brassica or Ipomoea.
相似文献99.
Tetsuya Masuda Keisuke Ohta Fumito Tani Bunzo Mikami Naofumi Kitabatake 《Biochemical and biophysical research communications》2011,(3):41
Thaumatin, an intensely sweet-tasting protein, elicits a sweet taste sensation at 50 nM. Here the X-ray crystallographic structure of one of its variants, thaumatin II, was determined at a resolution of 1.27 Å. Overall structure of thaumatin II is similar to thaumatin I, but a slight shift of the Cα atom of G96 in thaumatin II was observed. Furthermore, the side chain of residue 67 in thaumatin II is highly disordered. Since residue 67 is one of two residues critical to the sweetness of thaumatin, the present results suggested that the critical positive charges at positions 67 and 82 are disordered and the flexibility and fluctuation of these side chains would be suitable for interaction of thaumatin molecules with sweet receptors. 相似文献
100.
Yuta?Suzuki Dinesh?Adhikari Kazuhito?ItohEmail author Kousuke?Suyama 《Plant and Soil》2014,374(1-2):915-924