Search

Soil pollution by heavy metals is a serious environmental concern globally. Hexavalent (VI) chromium (Cr) is one of the main pollutants causing groundwater and soil heavy metal pollution. Miscanthus sinensis is a C4 perennial grass species with a high level of heavy metal tolerance. This species can effectively remove Cr from soils and maintain desirable biomass production under Cr stress. This research aimed to characterize and compare Cr accumulation in 58 genotypes of M. sinensis and to develop Expressed Sequence Tag–Simple Sequence Repeat (EST-SSR) markers associated with Cr tolerance. The results show that the pattern of translocation of Cr in plants differed among the 58 M. sinensis genotypes following treatment of 200 mg/L of Cr6+; however, in most genotypes, the Cr was primarily accumulated in roots. A total of 43,367 EST-SSRs were identified, and 88 EST-SSR primer pairs corresponding to candidate genes involved in Cr accumulation in M. sinensis were selected for validation. Subsequently, 170 polymorphic loci generated from 24 validated EST-SSRs were used for the population structure and marker–trait association analysis. Based on a general linear model (GLM), a total of 46 associations were identified (p < 0.05), with 14 EST-SSRs markers associated with target traits. Among them, four genes related to ABC transporters, wall-associated receptor kinases, as well as two high-affinity sulfate transporters (ST), were identified under Cr stress (p < 0.05). The results of this study help to accelerate the screening across M. sinensis genotypes for desirable traits under Cr stress and provide a platform for M. sinensis genetic improvement and molecular-marker-assisted breeding. [ABSTRACT FROM AUTHOR]

Summary: Edeines, a group of cationic antimicrobial peptides produced by the soil bacterium Brevibacillus, have broad biological effects, such as antimicrobial, anticancer and immunosuppressive activities. However, the yield of edeines in wild‐type (WT) Brevibacillus is extremely low, and chemical synthesis of edeines is a time‐consuming process. Genetic engineering has proven to be an effective approach to produce antibiotics with high yield. In this study, the edeine biosynthetic gene cluster (ede BGC), which is involved in edeine production, was identified and characterized in Brevibacillus brevis X23. To improve edeine production in B. brevis X23, the ede BGC promoter was replaced with six different promoters, Pmwp, Pspc, PxylA, Pshuttle‐09, Pgrac or P43, through double‐crossover homologous recombination. The new promoters significantly increased the expression of the ede BGC as well as edeine production by 2.9 ± 0.4 to 20.5 ± 1.2‐fold and 3.6 ± 0.1to 8.7 ± 0.7‐fold respectively. The highest yield of edeines (83.6 mg l−1) was obtained in B. brevis X23 with the Pmwp promoter. This study provides a practical approach for producing high yields of edeines in B. brevis. [ABSTRACT FROM AUTHOR]

To improve the aerodynamic sound quality of centrifugal fan, a centrifugal fan with rotating guide vanes was designed by the research group in which the flow field was simulated using MRF (multi-reference frame) method, so as to analyze the effect of number and profile of rotating guide vanes on the flow field of the centrifugal fan with and without rotating guide vanes. The results indicate that the rotating guide vanes can effectively uniform the flow field of the centrifugal fan, which creates favorable conditions for the improvement of the aerodynamic sound quality of the centrifugal fan; there is an optimum number of rotating guide vanes, so that when the flow field distribution is uniform, the work efficiency of centrifugal fan is the highest; the flow field uniformity of the centrifugal fan with inverse S-shaped guide vane profile is obviously better than that with normal S-shaped guide vane profile. The engineering application results are consistent with the simulation results. [ABSTRACT FROM AUTHOR]

Keloids are a common type of pathological skin healing, characterized by the destruction of the vascular network. Thus, keloids often exhibit anoxic conditions. Hypoxia‐inducible factor‐1α (HIF‐1α) is a core factor that mediates hypoxia stress responses and allows the cells to adapt to low‐oxygen conditions. In the current study, we identified that Parkin acted as an E3 ubiquitin ligase, contributing to the degradation of HIF‐1α in keloid fibroblasts (KFs). Silencing of Parkin in KFs upregulated HIF‐1α expression and prolonged its protein half‐life. Furthermore, Parkin influenced transforming growth factor β (TGF‐β)/Smad signaling by targeting HIF‐1α. Under hypoxic conditions, silencing Parkin enhanced KF proliferation and inhibited apoptosis through the TGF‐β/Smad signaling pathway. Notably, metformin, an antidiabetic drug, could significantly induce Parkin expression and enhance the interaction between Parkin and HIF‐1α. As a result, we revealed an important mechanism for Parkin in keloid development and suggested that targeting Parkin could be an alternative method for keloid treatment. [ABSTRACT FROM AUTHOR]

Based on the analysis of sampling data of Third National Women's Status Survey in 2010, this paper finds that household division of housework in urban China displays a characteristic of "women do much more than men". Household division of housework is influenced by the economic dependent relation between the couple, time spent on paid work and gender role attitude, and with quite different mechanisms for male and female. For male, economic independence and success is the best indicator for time spent on housework, with those more dependent economically shouldering much more household work. The influence of gender role attitude on division of housework is significant statistically and independently regardless of other factors. No gender display exists for male. Economic dependency is not the best predictor for female's housework involvement, and gender role attitude does not work independently as well. The interaction of economic dependency and gender-role attitude on household division displays very complex results for female, and the gender display appeared under such context has quite different patterns and effects. The effects of gender display decrease if women's gender-role attitude is increasingly toward modern. The gendered division of housework is shaped by the economic status of labor market and social cultural expectation and their interactions as well. Gender-role attitude plays as an intermediate variable between economic dependency and household division. So we give an explanation why household division of housework in China remains women doing more housework than men despite the fact that Chinese female greatly improve their economic situation and pay as much time as male on productive work. [ABSTRACT FROM AUTHOR]