Diverse Krill Lipid Fractions Differentially Reduce LPS-Induced Inflammatory Markers in RAW264.7 Macrophages In Vitro

Antarctic krill oil is an emerging marine lipid and expected to be a potential functional food due to its diverse nutrients, such as eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), phospholipids, astaxanthin and tocopherols. Although krill oil has been previously proved to have anti-inflammatory activity, there is little information about the relationship between its chemical compositions and anti-inflammatory activity. In this study, the RAW264.7 macrophages model was used to elucidate and compare the anti-inflammatory potential of different krill lipid fractions: KLF-A, KLF-H and KLF-E, which have increasing phospholipids, EPA and DHA contents but decreasing astaxanthin and tocopherols levels. Results showed that all the krill lipid fractions alleviated the inflammatory reaction by inhibition of production of nitric oxide (NO), release of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 and gene expression of proinflammatory mediators including TNF-α, IL-1β, IL-6, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). In addition, KLF-E with the highest phospholipids, EPA and DHA contents showed the strongest inhibition effect on the LPS-induced proinflammatory mediator release and their gene expressions. The results would be helpful to provide powerful insights into the underlying anti-inflammatory mechanism of krill lipid and guiding the production of krill oil products with tailor-made anti-inflammatory activity

Positive Feedback of Dust Direct Radiative Effect on Dust Emission in Taklimakan Desert

Abstract Dust direct radiative effect (DDRE) can modify the near‐surface air temperature, which can in turn influence dust emission. However, the feedback mechanism of DDRE on dust emission is poorly understood. In this study, the influence of DDRE on dust emission in Taklimakan Desert (TD) was investigated using comprehensive ground‐based observations. The results show that the near‐surface air temperature significantly decreased as a result of DDRE, corresponding to dust emission enhanced. Statistically, the contributions of DDRE to dust emission during light, moderate, and heavy dusty episodes were 5.0% (3.6%), 5.2% (2.8%), and 6.1% (3.3%) in spring (summer), respectively. From the perspective of mechanism, DDRE can induce an increase in air density by cooling the near‐surface, causing an enhancement of aerodynamic drag, promoting dust emission in TD. Such positive feedback of DDRE on dust emission may be a potential contributor to improving the dust emission scheme of numerical modeling in the future

Phase-enabled metal-organic framework homojunction for highly selective CO2 photoreduction

Conversion of clean solar energy to chemical fuels is one of the promising and up-and-coming applications of metal–organic frameworks. However, fast recombination of photogenerated charge carriers in these frameworks remains the most significant limitation for their photocatalytic application. Although the construction of homojunctions is a promising solution, it remains very challenging to synthesize them. Herein, we report a well-defined hierarchical homojunction based on metal–organic frameworks via a facile one-pot synthesis route directed by hollow transition metal nanoparticles. The homojunction is enabled by two concentric stacked nanoplates with slightly different crystal phases. The enhanced charge separation in the homojunction was visualized by in-situ surface photovoltage microscopy. Moreover, the as-prepared nanostacks displayed a visible-light-driven carbon dioxide reduction with very high carbon monooxide selectivity, and excellent stability. Our work provides a powerful platform to synthesize capable metal–organic framework complexes and sheds light on the hierarchical structure-function relationships of metal–organic frameworks