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61.
The fate of [14C] gibberellin A3 and [3H] gibberellin A1 was examined in senescing fruit of Shamouti orange (Citrus sinensis L. Osbeck) and tomato (Lycopersicon esculentum Mill.). Gibberellin A3 was highly persistent in Citrus peel (t 1/2=18 days) and to a lesser degree in tomato (t 1/2=5.5 days). Ethylene and ethephon caused a slight enhancement of gibberellin A3 metabolism in Citrus and tomato fruit, respectively. Gibberellin A1 was metabolized by Citrus peel at a relatively high rate (t 1/2 < 24 h) and ethylene slightly reduced this rate. It is concluded that the ethylene-induced enhancement of senescence does not involve major effects on the deactivation of applied gibberellins.Abbreviations GA3
gibberellin A3
- GA1
gibberellin A1 相似文献
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Nissim Garti Francoise Tibika Sara Sarig Shaul Perlberg 《Biochemical and biophysical research communications》1980,97(3):1154-1162
A new method has been established to follow the inhibitory effect of some polymeric-dicarboxylic-amino-acids and other poly-anionic derivatives. The technique is based on using calcium specific electrode to measure continuously free calcium ion activity in solution to assess the formation of calcium oxalate precipitate.The retardation effect of Poly-L-glutamic and aspartic acids has been established in 5–100 ppm range and compared to other monomeric and polymeric compounds with inactivated functional groups. The retardation effect is in agreement with previous reports on inhibition effect on crystal growth rate of seed crystals, with the same retardants.The inhibitory effect was also determined with normal urine and compared to pathological urine. 相似文献
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65.
De Dreu CK Greer LL Handgraaf MJ Shalvi S Van Kleef GA 《Proceedings. Biological sciences / The Royal Society》2012,279(1731):1150-1154
In intergroup competition and conflict, humans benefit from coalitions with strong partners who help them to protect their in-group and prevail over competing out-groups. Here, we link oxytocin, a neuropeptide produced in the hypothalamus, to ally selection in intergroup competition. In a double-blind placebo-controlled experiment, males self-administered oxytocin or placebo, and made selection decisions about six high-threat and six low-threat targets as potential allies in intergroup competition. Males given oxytocin rather than placebo viewed high-threat targets as more useful allies and more frequently selected them into their team than low-threat targets. 相似文献
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Preis M Cohen T Sarnatzki Y Ben Yosef Y Schneiderman J Gluzman Z Koren B Lewis BS Shaul Y Flugelman MY 《Biochemical and biophysical research communications》2006,348(3):1024-1033
BACKGROUND: Fibulin-5 is a novel extracellular protein that is thought to act as a bridging peptide between elastin fibers and cell surface integrins in blood vessel wall. Fibulin-5 binding to endothelial cell (EC) surface integrins may effect cell proliferation and cell attachment to extracellular matrix (ECM) or to artificial surfaces. In this paper, we describe the effects of fibulin-5 on attachment, adhesion, and proliferation of primary human EC. After demonstrating that fibulin-5 over-expression inhibited EC proliferation, we tested the hypothesis that co-expression of fibulin-5 and VEGF165 will lead to unique EC phenotype that will exhibit increased adherence properties and retain its proliferation capacity. METHODS AND RESULTS: Fibulin-5 and VEGF165 gene transfer to primary human saphenous vein endothelial cells was accomplished using retroviral vectors encoding the two genes. Transgene expression was verified using immunohistochemistry, Western blotting, and ELISA. Fibulin 5 over-expression tended to improve immediate EC attachment (30 min after seeding) and improved significantly adhesion (>40%) under shear stress tested 24h after EC seeding. The effects of fibulin-5 and VEGF165 on EC proliferation in the presence or absence of basic FGF were also tested. EC expressing fibulin-5 had reduced proliferation while VEGF165 co-expression ameliorated this effect. CONCLUSION: Fibulin-5 improved EC attachment to artificial surfaces. Dual transfer of fibulin-5 and VEGF165 resulted in EC phenotype with increased adhesion and improved proliferation. This unique EC phenotype can be useful for tissue engineering on endovascular prostheses. 相似文献
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c-Abl tyrosine kinase is activated by agents that induce double-strand DNA breaks (DSBs) and interacts with key components of the DNA damage response and of the DSB repair machinery. However, the functional significance of c-Abl in these processes, remained unclear. In this study, we demonstrate, using comet assay and pulsed-field gel electrophoresis, that c-Abl inhibited the repair of DSBs induced by ionizing radiation, particularly during the second and slow phase of DSB repair. Pharmacological inhibition of c-Abl and c-Abl depletion by siRNA-mediated knockdown resulted in higher DSB rejoining. c-Abl null MEFs exhibited higher DSB rejoining compared with cells reconstituted for c-Abl expression. Abrogation of c-Abl kinase activation resulted in higher H2AX phosphorylation levels and higher numbers of post-irradiation γH2AX foci, consistent with a role of c-Abl in DSB repair regulation. In conjunction with these findings, transient abrogation of c-Abl activity resulted in increased cellular radioresistance. Our findings suggest a novel function for c-Abl in inhibition of the slow phase of DSB repair. 相似文献