全文获取类型
收费全文 | 1713篇 |
免费 | 130篇 |
出版年
2022年 | 10篇 |
2021年 | 8篇 |
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 19篇 |
2017年 | 18篇 |
2016年 | 31篇 |
2015年 | 44篇 |
2014年 | 37篇 |
2013年 | 73篇 |
2012年 | 75篇 |
2011年 | 64篇 |
2010年 | 58篇 |
2009年 | 45篇 |
2008年 | 70篇 |
2007年 | 77篇 |
2006年 | 93篇 |
2005年 | 62篇 |
2004年 | 79篇 |
2003年 | 64篇 |
2002年 | 77篇 |
2001年 | 81篇 |
2000年 | 86篇 |
1999年 | 60篇 |
1998年 | 26篇 |
1997年 | 33篇 |
1996年 | 21篇 |
1995年 | 17篇 |
1994年 | 10篇 |
1993年 | 20篇 |
1992年 | 58篇 |
1991年 | 43篇 |
1990年 | 50篇 |
1989年 | 34篇 |
1988年 | 38篇 |
1987年 | 38篇 |
1986年 | 33篇 |
1985年 | 19篇 |
1984年 | 11篇 |
1983年 | 12篇 |
1982年 | 12篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1979年 | 14篇 |
1977年 | 7篇 |
1974年 | 7篇 |
1973年 | 8篇 |
1970年 | 7篇 |
1969年 | 13篇 |
1967年 | 9篇 |
排序方式: 共有1843条查询结果,搜索用时 15 毫秒
31.
Dilip M. Shah Cathy M. Hironaka Roger C. Wiegand Elizabeth I. Harding Gwen G. Krivi David C. Tiemeier 《Plant molecular biology》1986,6(4):203-211
Summary We have used the cDNA clone encoding maize glutathione-S-transferase (GST I) to isolate a genomic DNA clone containing the complete GST I gene. Nucleotide sequence analysis of the cDNA and genomic clones has yielded a complete amino acid sequence for maize GST I and provided the exon-intron map of its gene. The mRNA homologous sequences in the maize GST I gene consist of a 107 bp 5 untranslated region, a 642 bp coding region and 340 bp of the 3 untranslated region. They are divided into three exons by two introns which interrupt the coding region. The 5 untranslated spacer contains an unusual sequence of pentamer AGAGG repeated seven times. The inbred maize line (Missouri 17) contains a single gene for GST I, whereas the hybrid line (3780A) contains two genes. Nucleotide sequence analysis of the primer extended cDNA products reveals that the 5 untranslated regions of the two genes in the hybrid 3780A are identical except for a 6 bp internal deletion (or insertion). The amino acid sequence of maize GST I shares no apparent sequence homology with the published sequences of animal GST's and represents the first published sequence of a plant GST. re]19850813 ac]19851126 相似文献
32.
Flavonoids in the leaves of twenty-eight species belonging to the Polygonaceae were studied. Thirty-three kinds of flavonoids
were isolated, and eighteen kinds were obtained as crystals. Quercetin glycosides were commonly found in the family. In the
quercetin glycosides, 3-O-rhamnoside was most frequently found: 3-O-glucuronide is also distributed widely. Myricetin glycosides were rare. Methylated flavonols were found in some species of
the sectionsEchinocaulon andPersicaria. Eleven kinds ofC-glycosylflavones were found in the present survey, andC-glycosylflavones were distributed in all species of the genusRheum and in almost all species of the section Tiniaria.Rumex Acetosella andPolygonum suffultum are exceptional, the former contains flavone glycoside and the latterC-glycosylflavones only, as main components. 相似文献
33.
It was demonstrated that thyrotropin-releasing hormone (TRH) elicited a paradoxical increase in basal GH levels in cancer patients. Out of 94 cancer patients, 50 were found to be GH responders and this phenomenon was more frequently recognized in female than in male cancer patients. In cancer patients under 59 years of age, the GH response to TRH was significantly greater in females than in males, although there was no sex difference in the GH response in patients above 60 years of age. In female cancer patients, the GH response to TRH was significantly greater in patients under 59 years of age than in patients above 60 years of age, while there was no age difference in the GH response in male cancer patients. It was concluded that paradoxical responses of serum GH to TRH were recognized in 53 per cent of cancer patients and were more frequently observed in female than in male cancer patients. 相似文献
34.
35.
36.
37.
38.
39.
A new reaction for glycine biosynthesis 总被引:3,自引:0,他引:3
40.