OXIDIZED HIGH-DENSITY LIPOPROTEIN PROMOTES MATURATION AND MIGRATION OF BONE MARROW DERIVED DENDRITIC CELLS FROM C57BL/6J MICE

Objective To explore the influence of oxidized high-density lipoprotein （oxHDL） on the maturation and migration of bone marrow-derived dendritic cells （BMDCs） from C57BL/6J mice. Methods The C57BL/6J mice bone marrow cell suspension was prepared and purified. Recombinant granulocyte-macrophage colony-stimulating factor （rmGM-CSF） and recombinant interleukin-4 （rmlL-4） were used to promote monocytes to differentiate and suppress lymphocytes. Then 50μg/mL oxHDL was added to stimulate BMDCs, using 50μg/mL high-density lipoprotein （HDL） as homologous protein control, PBS as negative control, and 1 μg/mL lipopolysaccharide （LPS） as positive control. The CD86 and MHCII expression rates were detected with fluorescence-activated cell sorting （FACS）. Liquid scintillation counting （LSC） was used in mixed lymphocyte reactions （MLRs） to reflect the ability of BMDCs in stimulating the proliferation of homologous T cells, Levels of cytokines IL-12 and IL-10 were detected by ELISA. The cell migration was evaluated with the transwell system. Results Compared with PBS group, the expressions of CD86 and MHCII, counts per minute of MLRs, secretion of IL-12 and IL-10, and number of migrated cells in oxHDL group and LPS group significantly increased （all P 〈 0.05）, while the increment was less in oxHDL group than LPS group. The number of migrated cells in oxHDL group was about twice of that in HDL group. Conclusion OxHDL may promote the maturation and migration of BMDCs in vitro.

Main group metal elements for ambient-condition electrochemical nitrogen reduction

Electrocatalytic N_(2) reduction under ambient-condition is considered to be the most appealing strategy to the conventional Haber-Bosch process for synthetic ammonia to alleviate greenhouse emissions and reduce environmental pollution, mainly powered by renewable energy. Recent years, rapid advances have been gained in this attractive research field, and numerous electrocatalysts have been exploited. However, its conversion efficiency is still far behind the requirement of industrial applications owing to the breakage of the N≡N triple bond, which is an energetically challenging kinetically complex multistep reaction and the strong competing reaction of hydrogen evolution reaction. Recently, main group metal-based catalysts have been demonstrated promising application prospect for ammonia production, significantly boosting their further application in this field. However, a comprehensive review of main group metal-based catalysts towards electrochemical ammonia production applications is still lacking. In this review, the fundamentals of N_(2) reduction, such as the reaction pathways, the reaction potential and the challenges of N_(2) reduction have been comprehensively discussed. And then, the role, mechanism, and effect of each main group element-based catalysts used for N_(2) reduction (Li, K, Al, Ga, Sn, Sb, Bi, and their compounds) are systematically summarized. Finally, several state-of-the-art strategies to promote their NRR catalytic performance, as well as the existing problems and prospects are put forward. This review is expected to guide the design and establishment of more efficient electrocatalytic N_(2) reduction systems based on main group metal elements in the future.