De Novo Biosynthesis of Lutein in Yarrowia lipolytica.

Lutein is a high-value tetraterpenoid carotenoid that is widely used in feed, cosmetics, food, and drugs. Microbial synthesis of lutein is an important method for green and sustainable production, serving as an alternative to plant extraction methods. However, an inadequate precursor supply and low catalytic efficiency of key pathway enzymes are the main reasons for the low efficacy of microbial synthesis of lutein. In this study, some strategies, such as enhancing the MVA pathway and localizing α-carotene synthase OluLCY within the subcellular organelles in Yarrowia lipolytica, were adopted to enhance the synthesis of precursor α-carotene, which resulted in a 10.50-fold increase in α-carotene titer, reaching 38.50 mg/L. Subsequently, by improving hydroxylase activity with truncated N-terminal transport peptide and locating hydroxylases to subcellular organelles, the final strain L9 producing 75.25 mg/L lutein was obtained. Eventually, a lutein titer of 675.40 mg/L (6.13 mg/g DCW) was achieved in a 5 L bioreactor by adding the antioxidant 2,6-ditert-butyl-4-methylphenol. This study realizes de novo synthesis of lutein in Y. lipolytica for the first time and achieves the highest lutein titer reported so far.

Childhood Trauma and Malevolent Creativity in Chinese College Students: Moderated Mediation by Psychological Resilience and Aggression.

Although a previous study has shown that childhood trauma influences malevolent creativity, aggression and psychological resilience have been linked with childhood trauma and creativity. However, little is known about the complex correlations among these factors in Chinese college students. The present study aimed to investigate the mediating role of aggression and the moderating role of psychological resilience between childhood trauma and malevolent creativity. A total of 389 undergraduates were enrolled in this cross-sectional study. The moderated mediation model was conducted to explore whether aggression mediated the correlation between childhood trauma and malevolent creativity and whether psychological resilience moderated the indirect role of childhood trauma. The results showed that childhood trauma positively correlated with aggression and malevolent creativity and was negatively associated with psychological resilience. Aggression partly mediated the association of childhood trauma with malevolent creativity. Resilience moderated the indirect effect of the mediation model, such that the indirect effect of childhood trauma on malevolent creativity through aggression increased as the level of resilience increased. The study indicated that childhood trauma exposure is associated with malevolent creativity behavior, and aggression mediated this association. The level of psychological resilience differentiates the indirect paths of childhood trauma on malevolent creativity. These results have important implications for preventing and containing expressions of malevolent creativity.

Microstructure control of the wettability and adhesion of Al alloy surfaces.

This article provides a simple and fast method to adjust the wettability and adhesion of aluminum (Al) alloy surfaces after electric discharge machining (EDM). For an Al alloy plate after EDM, without any grinding and polishing, laser treatment was directly performed on the surface to prepare the Al alloy surface with different wettability and adhesion behaviors. Scanning electron microscopy was used to analyze the surface morphologies of the smooth surface, wire-cut surface, and the surface treated with different laser parameters after wire-cut. Then, the chemical composition, contact angle (CA) stability, adhesion and surface bounce behavior of the surfaces processed via different treatment steps were tested and analyzed. The results indicated that the crater structure was distributed randomly on the EDM-processed surface, with a static CA of 129 ± 1.2°. After laser engraving, the surface generates a regular arrangement of micron-level grooves/pits. Meanwhile, the molten Al alloy spattered at high temperatures and instantly solidified to produce sub-micron-sized metal particles attached to the pit/bottom of the trench and the unprocessed area, naturally forming a dual-scale structure. This naturally formed dual-scale structure makes the surface static CA up to 154.6 ± 1.2°. This technology realized that only laser treatment is used to control the wettability and adhesion of the Al alloy surface after EDM treatment and expected to provide a simple and low-cost method for the practical application of large-area superhydrophobic surfaces.