Hydrogen evolution reaction is a critical reaction in water splitting for hydrogen production.However,developing effective and stable non‐noble‐metal electrocatalysts which work well at high current densities demand...Hydrogen evolution reaction is a critical reaction in water splitting for hydrogen production.However,developing effective and stable non‐noble‐metal electrocatalysts which work well at high current densities demanded by industry still remain great challenge.Herein,taking advantage of the highly tunable metal‐organic framework(MOF)templates,nitrogen doped binary transition metal phosphides electrocatalysts(N‐CoP_(x)/Ni_(2)P)with three‐dimensional(3D)conductive network structure were successfully synthesized.The 3D open porous channels could expose more catalytically active sites;nitrogen doping and the synergistic effect between CoP and Ni_(2)P can increase the electron density of Co atoms at active sites,further optimizing the Gibbs free energy of hydrogen(ΔGH*)and water(ΔG_(H_(2)O*)).As a result,the obtained N‐CoP_(x)/Ni_(2)P catalyst exhibits extraordinary electrocatalytic activity in a wide pH range.Especially,it requires an extremely low overpotential of 152 mV to deliver a high current density of 650 mA cm^(–2) in alkaline media.This work may shed some light on the rational design of cheap electrocatalysts and electrode materials that work well at high current densities.展开更多
Objective： To investigate the molecular pathway of substance P （SP） to induce osteoblastic differentiation. Methods： Mesenchymal stem cells were isolated and cultured. The cultures were divided into four groups w...Objective： To investigate the molecular pathway of substance P （SP） to induce osteoblastic differentiation. Methods： Mesenchymal stem cells were isolated and cultured. The cultures were divided into four groups with Group A （control group） cultured without any factors, Group B cultured with SP, Group C cultured with SP and SP receptor neurokinin-1 （NK1） antagonist, and Group D cultured with SP NK1 antagonist respectively to induce osteoblastic cells differentiation. Osterix gene expression was detected by reverse transcription-polymerase chain reaction （RT-PCR） for three times after 1-2 weeks of cultivation and the results were analyzed by one-way analysis of variance （ANOVA）. Results： The log phase of bone marrow stromal cells appeared at 4-6 days. ALP staining revealed that the majority of cells, more than 95%, were positive and small bluepurple granules were found in the cytoplasm. And Group B, treated with SP, showed a higher level of ALP activity than the other three groups. Meanwhile, RT-PCR found that Osterix expression in Group B was obviously up-regulated, compared with other groups. But Osterix expression in Group D had no remarkable differences, compared with the controls. Conclusions： SP can up-regulate Osterix gene expression to stimulate differentiation of mesenchymal stem cells into osteoblastic cells at the final stage. The regulatory effect of SP on Osterix expression was dependant on SP NK1 receptors.展开更多
文摘Hydrogen evolution reaction is a critical reaction in water splitting for hydrogen production.However,developing effective and stable non‐noble‐metal electrocatalysts which work well at high current densities demanded by industry still remain great challenge.Herein,taking advantage of the highly tunable metal‐organic framework(MOF)templates,nitrogen doped binary transition metal phosphides electrocatalysts(N‐CoP_(x)/Ni_(2)P)with three‐dimensional(3D)conductive network structure were successfully synthesized.The 3D open porous channels could expose more catalytically active sites;nitrogen doping and the synergistic effect between CoP and Ni_(2)P can increase the electron density of Co atoms at active sites,further optimizing the Gibbs free energy of hydrogen(ΔGH*)and water(ΔG_(H_(2)O*)).As a result,the obtained N‐CoP_(x)/Ni_(2)P catalyst exhibits extraordinary electrocatalytic activity in a wide pH range.Especially,it requires an extremely low overpotential of 152 mV to deliver a high current density of 650 mA cm^(–2) in alkaline media.This work may shed some light on the rational design of cheap electrocatalysts and electrode materials that work well at high current densities.
文摘Objective： To investigate the molecular pathway of substance P （SP） to induce osteoblastic differentiation. Methods： Mesenchymal stem cells were isolated and cultured. The cultures were divided into four groups with Group A （control group） cultured without any factors, Group B cultured with SP, Group C cultured with SP and SP receptor neurokinin-1 （NK1） antagonist, and Group D cultured with SP NK1 antagonist respectively to induce osteoblastic cells differentiation. Osterix gene expression was detected by reverse transcription-polymerase chain reaction （RT-PCR） for three times after 1-2 weeks of cultivation and the results were analyzed by one-way analysis of variance （ANOVA）. Results： The log phase of bone marrow stromal cells appeared at 4-6 days. ALP staining revealed that the majority of cells, more than 95%, were positive and small bluepurple granules were found in the cytoplasm. And Group B, treated with SP, showed a higher level of ALP activity than the other three groups. Meanwhile, RT-PCR found that Osterix expression in Group B was obviously up-regulated, compared with other groups. But Osterix expression in Group D had no remarkable differences, compared with the controls. Conclusions： SP can up-regulate Osterix gene expression to stimulate differentiation of mesenchymal stem cells into osteoblastic cells at the final stage. The regulatory effect of SP on Osterix expression was dependant on SP NK1 receptors.
