全文获取类型
收费全文 | 2410篇 |
免费 | 109篇 |
国内免费 | 3篇 |
出版年
2022年 | 7篇 |
2021年 | 12篇 |
2020年 | 6篇 |
2019年 | 9篇 |
2018年 | 12篇 |
2017年 | 18篇 |
2016年 | 26篇 |
2015年 | 39篇 |
2014年 | 74篇 |
2013年 | 391篇 |
2012年 | 97篇 |
2011年 | 122篇 |
2010年 | 91篇 |
2009年 | 63篇 |
2008年 | 137篇 |
2007年 | 138篇 |
2006年 | 126篇 |
2005年 | 154篇 |
2004年 | 159篇 |
2003年 | 142篇 |
2002年 | 149篇 |
2001年 | 23篇 |
2000年 | 11篇 |
1999年 | 27篇 |
1998年 | 29篇 |
1997年 | 25篇 |
1996年 | 32篇 |
1995年 | 24篇 |
1994年 | 13篇 |
1993年 | 22篇 |
1992年 | 21篇 |
1991年 | 24篇 |
1990年 | 16篇 |
1989年 | 11篇 |
1988年 | 17篇 |
1987年 | 9篇 |
1986年 | 10篇 |
1985年 | 14篇 |
1984年 | 19篇 |
1983年 | 12篇 |
1982年 | 24篇 |
1981年 | 30篇 |
1980年 | 22篇 |
1979年 | 10篇 |
1978年 | 15篇 |
1977年 | 15篇 |
1976年 | 14篇 |
1975年 | 11篇 |
1974年 | 13篇 |
1973年 | 6篇 |
排序方式: 共有2522条查询结果,搜索用时 0 毫秒
981.
Hidehito Urata Masayuki Urata Masao Akagi Hidekazu Hiroaki Seiich Uesugi 《Nucleosides, nucleotides & nucleic acids》2013,32(6-7):1259-1269
Abstract We investigated the structure of a decadeoxynucleotide duplex which was modified with Dichloroethylenediamineplatinum(II) (PtCl2(en)) at the central GG site by using some spectroscopic techniques. The results suggest that the DNA structural changes induced by binding of PtCl2(en) are quite similar to those of cisplatin. 相似文献
982.
Sera Toshihiro Kobayashi Hiroaki Hoshino Masato Uesugi Kentaro Matsumoto Takeshi Tanaka Masao 《Biomechanics and modeling in mechanobiology》2019,18(2):375-385
Biomechanics and Modeling in Mechanobiology - In this study, based on the measurements of intracortical vascular canal structure, we investigated the disuse effect on local O2 supply in the... 相似文献
983.
984.
985.
Takashi Matsumoto Naomi Kanno Tsutomu Ikeda Yukiteru Obi Takuro Kisaki Masao Noguchi 《Bioscience, biotechnology, and biochemistry》2013,77(7):1627-1633
Strains producing high levels of ubiquinone 10 were isolated from tobacco cell suspension cultures by a cell cloning technique, and the UQ content of these cell strains was analyzed by high performance liquid chromatography. Three strains with high UQ yields in suspension culture were selected and used for investigations on the necessary cultural conditions for UQ production. Sucrose concentration, 2,4-D concentration and culture temperature did not have marked effects on UQ formation. These results differed from those of the original cell lines. Furthermore, the addition of yeast extract to the medium promoted cell growth in these strains remarkably but did not enhance UQ production in the cell strains. According to these investigations, UQ production was increased to 15mg/liter and the UQ level to 1890 μg/g dry wt. of cells after 11 days of incubation. 相似文献
986.
Superoxide dismutase (SOD)-like compounds and activators of SOD were screened for in the extracts of fruits, vegetables, and mushrooms by measuring their effects on pyrogallol autoxidation, which is catalyzed by superoxide anion. SOD-like activity was high in aqueous extract of nameko, garlic, broccoli, and oriental lettuce. Ethanolic extracts of onion and watermelon could enhance human SOD activity more than 40%. 相似文献
987.
988.
989.
Two 5′-nucleotidase-lacking mutants, R–42 and A–1, were derived from an adenine-requiring mutant, B. subtilis 1145–2–83, which has productivity of both inosine and hypoxanthine. Strain A–1 accumulated 5′-IMP as well as inosine and hypoxanthine, and strain R–42 accumulated 5′-IMP and 5′-GMP as well as inosine and hypoxanthine in their culture fluids. These mutants responded to either adenine or adenosine, but did not to 5′-AMP. This fact suggests that adenine or adenosine may be incorporated into the cells, but 5′-AMP may neither be incorporated into the cells nor be degraded during culture. 5′-GMP was converted to 5′-IMP, and 5′-AMP was phosphrylated to ADP in the growing culture of strain A–1. 相似文献
990.
Pao-Shui Wang Hiromichi Kato Masao Fujimaki 《Bioscience, biotechnology, and biochemistry》2013,77(12):1775-1781
Basic compounds in the volatiles of roasted barley were analyzed by a gas chromatograph and a combination instrument of gas chromatograph-mass spectrometer. As major components, the following nitrogeneous aromatic compounds were identified: pyridine, 2-methylpyrazine, 2,5-dimethylpyrazine, 2-ethyl-5-methylpyrazine, 2,3,5-trimethylpyrazine and a dimethylethylpyrazine. Ammonia was also detected in the volatiles of roasted barley by an amino acid analyzer.The formation of 2,5-dimethylpyrazine from pyruvaldehyde-amino acid model systems during roasting was shown, and the possible formation mechanism of pyrazines was presented. 相似文献