RESUMEN
Catalytic transformation of low-cost glycerol to value-added lactic acid (LA) is considered as one of the most promising technologies for the upgradation of glycerol into renewable products. Currently, research studies reveal that anaerobic transformation of glycerol to LA could also obtain green H2 with the same yield of LA. However, the combined value-added utilization of released H2 with high selectivity of LA during glycerol conversion under mild conditions still remains a grand challenge. In this perspective, for the first time, we conducted a comprehensive and critical discussion on current strategies for combined one-pot/tandem dehydrogenation of glycerol to LA with catalytic transfer hydrogenation of H2 acceptors (such as CO2) to other chemicals. The aim of this overview was to provide a general guidance on the atomic economic reaction pathway for upgrading low-cost glycerol and CO2 to LA as well as other chemicals.
RESUMEN
OBJECTIVE: To observe the effect of the estrogen on the mRNA expression of osteoprotegerin (OPG), osteoclast differentiation factor (ODF) and macrophage colony stimulating factor (M-CSF) in bone tissue of ovariectomized rats, and investigate the possible pathway of estrogen in preventing and treating postmenopausal osteoporosis. METHODS; Thirty healthy adult SD rats were randomly divided into sham operation group, ovariectomized group and estrogen-treated group. All rats were ovariectomized except those in the sham operation group. Bone density of the L3-L6 vertebra was detected 12 weeks after the operation. The total RNA were extracted from the femur to examine mRNA expression of OPG, ODF and M-CSF by real-time PCR. RESULTS: Estrogen increased the bone density of the ovariectomized rat lumbar vertebra and up-regulated the expression of OPG, whereas down-regulated the expression of M-CSF and lowered ODF:OPG ratio. CONCLUSION: The effect of estrogen in treating postmenopausal osteoporosis is closely correlated with the regulation of OPG and M-CSF expressions and ODF:OPG ratio.