全文获取类型
收费全文 | 276篇 |
免费 | 12篇 |
国内免费 | 25篇 |
出版年
2024年 | 2篇 |
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 10篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 5篇 |
2017年 | 7篇 |
2016年 | 7篇 |
2015年 | 10篇 |
2014年 | 15篇 |
2013年 | 36篇 |
2012年 | 17篇 |
2011年 | 10篇 |
2010年 | 7篇 |
2009年 | 17篇 |
2008年 | 12篇 |
2007年 | 11篇 |
2006年 | 14篇 |
2005年 | 17篇 |
2004年 | 16篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有313条查询结果,搜索用时 31 毫秒
301.
302.
303.
Mengen Li ;Yiwen Chen ;Zhongyu Liu ;Fubing Shen ;Xiaoxiao Bian ;Yanfa Meng 《Acta biochimica et biophysica Sinica》2009,(9):792-799
Ribosome-inactivating proteins (RIPs) are a family of enzymes that depurinate rRNA and inhibit protein biosynthesis. Here we report the purification, apoptosisinducing activity, and polyethylene glycol (PEG) modification of RIP from the bitter melon seeds. The protein has a homogenous N-terminal sequence of N- Asp-Val-Ser-Phe-Arg. Moreover, the RIP displayed strong apoptosis-inducing activity and suppressed cancer cell growth. This might be attributed to the acti- vation of caspases-3. To make it available for in vivo application, the immunogenicity of RIP was reduced by chemical modification with 20 kDa (mPEG)2-Lys-NHS. The inhibition activity of both PEGylated and non- PEGylated RIP against cancer cells was much stronger than against normal cells, and the antigenicity of PEGylated RIP was reduced significantly. Our results suggested that the PEGylated RIP might be potentially developed as anti-cancer drug. 相似文献
304.
Lindsay A. Greer John D. I. Harper Christopher C. Steel 《Journal of Phytopathology》2014,162(6):407-410
Detached Vitis vinifera (cv Chardonnay) inflorescences were inoculated with spore suspensions of either Colletotrichum acutatum or Greeneria uvicola at 25°C, and a combination of light microscopy, scanning electron microscopy and plating out of inoculated flowers on to dichloran rose bengal chloramphenicol agar was used to investigate the time frame for infection. Colletotrichum acutatum infection commenced within 2 h of inoculation, while infection by G. uvicola commenced between 12 and 18 h postinoculation. All parts of the flowers were infected by both fungi. 相似文献
305.
306.
In Humulus lupulus, leucine undergoes transamination, and incorporation into desoxyhumulone and lupulone. We therefore propose that leucine is the precursor for the isovaleryl residue of the hop bitter compounds; the same appears to be true for valine and isoleucine as precursors for the isobutyryl and 2-methyl butyryl residues. 相似文献
307.
Melon aphid performance on chrysanthemum as mediated by cultivar, and differential levels of fertilization and irrigation 总被引:4,自引:0,他引:4
James A. Bethke Richard A. Redak Ursula K. Schuch 《Entomologia Experimentalis et Applicata》1998,88(1):41-47
Population parameters of the melon aphid, Aphis gossypii Glover, were compared for insects grown on six cultivars of chrysanthemum, Dendranthema grandiflora Tzvelev ('Fontana', 'Iridon', 'Pink Lady', 'Splendor', 'White Diamond', and 'White View Time') fertilized with 3 different levels of nitrogen (80, 160 and 240 mg N/l) and 2 levels of irrigation (high 300 ml and low 210 ml every other day). Fecundity, longevity, and survivorship of aphids were significantly affected by the cultivar treatment, but were not affected by irrigation or fertilizer treatments or by any combination of interactions among cultivar, fertilizer and irrigation. Significantly fewer aphids survived on the cultivar 'Pink Lady' (populations reduced by 20.8%) than any other cultivar examined. Intrinsic rates of increase r
m
, finite rates of increase (R
0), and population doubling times (DT) for aphids were different among fertilizer levels and cultivars, but were not different among irrigation levels. There were no significant fertilizer by irrigation interaction effects upon r
m
, R
0, or DT. The highest rate of fertilizer applied (240 mg N/liter) adversely affected the intrinsic rate of increase of melon aphids; however, aphid intrinsic rate of increase was weakly correlated with foliar soluble protein levels (r=0.989, P=0.0954). Foliar soluble protein levels were not associated with fertilization treatment. Melon aphids perform consistently better on the cultivars 'White Diamond', 'Fontana', and 'Splendor', relative to those aphids growing on 'Iridon', 'Pink Lady', or 'White View Time'. In general, melon aphids performed best on 'White Diamond' and poorest on 'Pink Lady'. 相似文献
308.
Cucurbitacin Q1, a compound isolated from the fruit of Cucumis prophetarum, has been shown to be the pure trans component of cucurbitacin Q. 相似文献
309.
The incorporation of labeled precursors into hop bitter compounds is presented and a scheme for the biosynthesis of these substances via 1-acyl-3-prenyl phloroglucinols is proposed. 相似文献
310.