Fermentation Improves Calcium Bioavailability in Moringa oleifera leaves and Prevents Bone Loss in Calcium‐deficient Rats

Abstract Nowadays, there is an increasing demand of healthier plant calcium supplements. Moringa oleifera leaves (MOL) are rich in calcium and thus are promising candidates for developing efficient calcium supplements. Here, using fermentation‐based approaches, we developed a Moringa oleifera leaf ferment (MOLF), which contents higher levels of calcium. The therapeutic potential of the MOLF was also examined both in vitro and in vivo. Nine lactic acid bacteria and four yeasts were tested for better fermentation of MOL. Calcium‐deficient rats were used for evaluating the therapeutic effects of MOLF. The results of liquid fermentation showed that the mixture of Lactobacillus reuteri, Lactobacillus acidophilus, and Candida utilis elevated the content of MOL calcium most strikingly, with the content of calcium increased nearly 2.4‐fold (from 2.08% to 4.90%). The resulting MOLF was then subjected to cell experiments and animal experiments. The results showed that calcium absorption in Caco‐2 cells in MOLF group was higher than that in CaCl2 group significantly. Interestingly, in calcium‐deficient rats, MOLF treatment significantly increased the thickness of cortical bone, rat body weight, wet weight of the femur, and the femur bone density, whereas it decreased osteoclast numbers. These results indicate that microbial fermentation increased calcium bioavailability of MOL, promote the growth and development of calcium‐deficient rats, bone calcium deposition, and bone growth; enhance bone strength; reduce bone resorption; and prevent calcium deficiency

Super-Reversible CuF2 Cathodes Enabled by Cu\u3csup\u3e2+\u3c/sup\u3e-Coordinated Alginate

Copper fluoride (CuF2) has the highest energy density among all metal fluoride cathodes owing to its high theoretical potential (3.55 V) and high capacity (528 mAh g−1). However, CuF2 can only survive for less than five cycles, mainly due to serious Cu-ion dissolution during charge/discharge cycles. Herein, copper dissolution is successfully suppressed by forming Cu2+-coordinated sodium alginate (Cu-SA) on the surface of CuF2 particles during the electrode fabrication process, by using water as a slurry solvent and sodium alginate (SA) as a binder. The trace dissolved Cu2+ in water from CuF2 can in situ cross-link with SA binder forming a conformal Cu-SA layer on CuF2 surface. After water evaporation during the electrode dry process, the Cu-SA layer is Li-ion conductor but Cu2+ insulator, which can effectively suppress the dissolution of Cu-ions in the organic 4 m LiClO4/ethylene carbonate/propylene carbonate electrolyte, enhancing the reversibility of CuF2. CuF2 electrode with SA binder delivers a reversible capacity of 420.4 mAh g-1 after 50 cycles at 0.05 C, reaching an energy density of 1009.1 Wh kg-1. Cu2+ cross-link polymer coating on CuF2 opens the door for stabilizing the high-energy and low-cost CuF2 cathode for next-generation Li-ion batteries

Controllable Synthesis of Cu₂In₂ZnS₅ Nano/Microcrystals and Hierarchical Films and Applications in Dye-Sensitized Solar Cells

Cu₂­In₂­ZnS₅ microcrystals with controllable nanostructures are synthesized via a facile solvothermal method. The microcrystals consist of numerous nanorods packed along a preferred crystal orientation. The crystal size of Cu₂­In₂­ZnS₅ is tunable into the nanoscale. Cu₂­In₂­ZnS₅ nanocrystals are composed of nanoparticles with an average size of 4.2 nm. Moreover, microcrystals were assembled on a molybdenum substrate to form a Cu₂­In₂­ZnS₅ thin film with a hierarchical architecture. The hierarchical nanostructure benefits to increase the optical path, decrease the reflection to capture photons effectively, and provide multiple channels for directly transferring charges to the conducting substrate. The hierarchical thin films were exploited as counter electrodes of dye-sensitized solar cells, which enhanced the catalytic activity of the counter electrode. The power conversion efficiency reached up to 6.1%, comparable to that of the dye-sensitized solar cells with a Pt counter electrode