Water-involving transfer hydrogenation and dehydrogenation of N-heterocycles over a bifunctional MoNi_(4)electrode

A room-temperature electrochemical strategy for hydrogenation(deuteration)and reverse dehydrogenation of N-heterocycles over a bifunctional MoNi_(4)electrode is developed,which includes the hydrogenation of quinoxaline using H2O as the hydrogen source with 80%Faradaic efficiency and the reverse dehydrogenation of hydrogen-rich 1,2,3,4-tetrahydroquinoxaline with up to 99%yield and selectivity.The in situ generated active hydrogen atom(H^(*))is plausibly involved in the hydrogenation of quinoxaline,where a consecutive hydrogen radical coupled electron transfer pathway is proposed.Notably,the MoNi_(4)alloy exhibits efficient quinoxaline hydrogenation at an overpotential of only 50 mV,owing to its superior water dissociation ability to provide H^(*)in alkaline media.In situ Raman tests indicate that the Ni^(Ⅱ)/Ni^(Ⅲ)redox couple can promote the dehydrogenation process,representing a promising anodic alternative to low-value oxygen evolution.Impressively,electrocatalytic deuteration is easily achieved with up to 99%deuteration ratios using D2O.This method is capable of producing a series of functionalized hydrogenated and deuterated quinoxalines.

Bifurcation and optimal control for an infectious disease model with the impact of information

A nonlinear infectious disease model with information-influenced vaccination behavior and contact patterns is proposed in this paper,and the impact of information related to disease prevalence on increasing vaccination coverage and reducing disease incidence during the outbreak is considered.First,we perform the analysis for the existence of equilibria and the stability properties of the proposed model.In particular,the geometric approach is used to obtain the sufficient condition which guarantees the global asymptotic stability of the unique endemic equilibrium Ee when the basic reproduction number Ro>1.Second,mathematical derivation combined with numerical simulation shows the existence of the double Hopf bifurcation around Ee.Third,based on the numerical results,it is shown that the information coverage and the average information delay may lead to more complex dynamical behaviors.Finally,the optimal control problem is established with information-infuenced vaccination and treatment as control variables.The corresponding optimal paths are obtained analytically by using Pontryagin's maximum principle,and the applicability and validity of virous intervention strategies for the proposed controls are presented by numerical experiments.

Natural okra-based hydrogel for chronic diabetic wound healing

As a representative of chronic wounds,the long-term high levels of oxidative stress and blood sugar in chronic diabetic wounds lead to serious complications,making them the biggest challenge in the research on wound healing.Many edible natural biomaterials rich in terpenes,phenols,and flavonoids can act as efficient antioxidants.In this study,okra extract was selected as the main component of a wound dressing.The okra extracts obtained via different methods comprehensively maintained the bioactivity of multiple molecules.The robust antioxidant properties of okra significantly reduced intracellular reactive oxygen species production,thereby accelerating the wound healing process.The results showed that okra extracts and their hydrogel dressings increased cell migration,angiogenesis,and re-epithelization of the chronic wound area,considerably promoting wound remodeling in diabetic rats.Therefore,okra-based hydrogels are promising candidates for skin regeneration and wider tissue engineering applications.

Three-dimensional (3D) scaffolds as powerful weapons for tumor immunotherapy

Though increasing understanding and remarkable clinical successes have been made, enormous challenges remain to be solved in the field of cancer immunotherapy. In this context, biomaterial-based immunomodulatory strategies are being developed to boost antitumor immunity. For the local immunotherapy, macroscale bioma-terial scaffolds with 3D network structures show great superiority in the following aspects: facilitating the encapsulation, localized delivery, and controlled release of immunotherapeutic agents and even immunocytes for more efficient immunomodulation. The concentrating immunomodulation in situ could minimize systemic tox-icities, but still exert abscopal effects to harness the power of overall anticancer immune response for eradicating malignancy. To promote such promising immunotherapies, the design requirements of macroscale 3D scaffolds should comprehensively consider their physicochemical and biological properties, such as porosity, stiffness, surface modification, cargo release kinetics, biocompatibility, biodegradability, and delivery modes. To date, increasing studies have focused on the relationships between these parameters and the biosystems which will guide/assist the 3D biomaterial scaffolds to achieve the desired immunotherapeutic outcomes. In this review, by highlighting some recent achievements, we summarized the latest advances in the development of various 3D scaffolds as niches for cancer immunotherapy. We also discussed opportunities, challenges, current trends, and future perspectives in 3D macroscale biomaterial scaffold-assisted local treatment strategies. More importantly, this review put more efforts to illustrate how the 3D biomaterial systems affect to modulate antitumor immune activities, where we discussed how significant the roles and behaviours of 3D macroscale scaffolds towards in situ cancer immunotherapy in order to direct the design of 3D immunotherapeutic.