玉米铁微营养生物有效性与生物强化的研究进展

综述了玉米子粒中铁的分析方法、生物有效性及其影响因素、铁生物强化的传统与分子育种途径的研究进展,并对HarvestPlus项目与组织作了概略的介绍。     

Impact of delphinidin on the maintenance of DNA integrity in human colon carcinoma cells

Delphinidin has been found to possess DNA strand-breaking properties in cell culture. In the present study, we demonstrated that the extent of DNA damage by delphinidin is not affected by the expression of tyrosyl-DNA-phosphodiesterase 1, indicating that the induction of DNA strand breaks is not predominantly topoisomerase-mediated. However, the DNA-damaging properties of delphinidin were decreased by the addition of catalase to the cell culture medium, counteracting delphinidin-mediated hydrogen peroxide formation. Under these conditions, delphinidin showed clearly antioxidative properties in HT29 cells, preventing menadione-induced oxidative DNA damage. In contrast, in the absence of catalase, delphinidin lacked antioxidative properties. In conclusion, delphinidin acted as an effective antioxidant within intact cells if the formation of hydrogen peroxide was prevented. In the absence of catalase, the accumulated hydrogen peroxide appears to play a substantial role for the observed DNA-damaging properties of delphinidin and the apparent lack of antioxidative properties of this anthocyanidin.     

Larval abundance across the European eel spawning area: An analysis of recent and historic data

The abundance and distribution of leptocephalus larvae of the European eel (Anguilla anguilla, Anguillidae) were examined using ten historic and recent Sargasso Sea expeditions that were selected on the basis of having the largest number of sampling stations and highest catches. The surveys cover the period 1920–2014. Station data were recalculated to the same unit of larval density per unit area, and the irregular station positions were transformed to a regular spatial grid to allow calculation of comparable measures of abundance of the youngest (0+) leptocephalus cohort. The result is that the mean and maximum densities of 0+ leptocephali after 2007 on average have decreased by 70%–80% from the densities during the period before the drastic decrease in glass eel recruitment, which started in the 1980s. This is of the same magnitude as the change in spawning stock, if the total continental commercial landings are used as a proxy. In the same period, the glass eel recruitment in Europe has decreased by more than 95%. The conclusion is that a major cause for the recruitment decrease may be an increased leptocephalus mortality during the oceanic phase or a large geographic shift in glass eel arrival. Combining the survey data, the spatial distribution of 0+ leptocephali was concentrated south of the northernmost front in the Subtropical Convergence Zone, but high densities were also found far south of the front in the western part of the distribution area and leptocephali were present also north of the average frontal position.