排序方式： 共有5条查询结果，搜索用时 78 毫秒
1
1.
2.
Hitoshi Obata Atsuo Shimoyama Masanao Umebayashi 《Soil Science and Plant Nutrition》2013,59(4):933-936
Under Zn deficiency, some major deficiency symptoms were observed on rice plants, i.e., reduction of young leaf elongation and development of necrosis on the expanded leaves. To clarify the former phenomena, the physiological role of Zn was studied from the standpoint of protein synthesis (Kitagishi and Obata 1986; Obata et al. 1994, 1996) and metabolism of auxin (Takaki and Arita 1986; Domingo et al. 1992). In contrast, the direct cause of the latter phenomenon has not yet been studied. 相似文献
3.
木塑复合材料耐候性能研究进展 总被引：1，自引：0，他引：1
木塑复合材料(WPC)的耐候性能决定了材料的户外使用寿命。文中介绍了国内外在WPC耐热氧老化、耐光氧老化、耐真菌腐朽及耐潮湿与冻融性能方面的研究进展。现有研究表明, 热氧老化与光氧老化均使得WPC发生褪色现象, 力学性能下降, 添加抗氧化剂与光稳定剂可分别改善二者对WPC的破坏作用。WPC中木粉含量较高时更易发生真菌腐朽现象, 添加化学防腐剂或其他助剂、木粉改性及涂饰可有效抑制真菌腐朽。WPC的吸水性是其热氧老化、光氧老化、真菌腐朽及冻融循环过程的催化剂。文中还总结了目前WPC耐候性能研究存在的主要问题, 并对其未来趋势进行了展望。 相似文献
4.
In order to study the photoreactivity and possible photodegradation pathways of ethiofencarb (2-ethylthiomethylphenyl methylcarbamate) on plant surfaces, model experiments in the presence of cyclohexane, cyclohexene methylcarbamate)onand iso-propanol were performed. Both artificial light (λ > 280 nm) and natural sunlight were used. Half-lives of the ethiofencarb photodegradation were in the order cyclohexane < isopropanol < cyclohexene and ranged from 75 min to more than 20 h. Depending on the solvent and the light source chosen, different photo-products were obtained. When ethiofencarb was irradiated in the presence of cyclohexane, photo-oxidation to the corresponding sulfoxide was the main degradation pathway, followed by a cyclization reaction. In the case of isopropanol as model solvent, numerous photoproducts were detected as a result of photo-oxidation, hydrolysis and the addition to ethiofencarb of the solvent molecule. 相似文献
5.
Enzymatic hydrolysates from Oysters (OAH) display multiple biological activities. Previously, a 3~5 KDa oyster ultrafiltration component (OUP) showed a high property of preventing skin oxidation. Subsequently, we identified specific peptides with such activity. OUP was fractionated stepwise by Sephadex-G25 and RP-HPLC, and active fractions were screened using UV-irradiated HaCaT cells. The most active fractions (OP5-3) were analyzed by LC-MS/MS and a total of 17 peptides were identified. Results from mass spectrometry showed that OP5-3 consisted of peptides with a molecular weight range of 841.51–1786.92 Da. Six of these peptides were synthesized for validating the activity of resisting skin oxidation in the same cell model. All six peptides showed varying degrees of antioxidant activity, while pretreatment of HaCaT cells with AIVAEVNEAAK alleviated UV cytotoxicity, inhibited metalloproteinase 1 (MMP-1) expression, and showed the highest activity to resist UV-induced skin photo-oxidation among these peptides. In addition, results from molecular docking analysis of MMP-1 with AIVAEVNEAAK showed that AIVAEVNEAAK suppresses its enzymatic activity by directly interacting with MMP-1 and thus exhibit anti-photoaging activity. 相似文献
1