Large bone defects resulting from fractures and disease are a major clinical challenge,being often unable to heal spontaneously by the body’s repair mechanisms.Lines of evidence have shown that hypoxia-induced overpr...Large bone defects resulting from fractures and disease are a major clinical challenge,being often unable to heal spontaneously by the body’s repair mechanisms.Lines of evidence have shown that hypoxia-induced overproduction of ROS in bone defect region has a major impact on delaying bone regeneration.However,replenishing excess oxygen in a short time cause high oxygen tension that affect the activity of osteoblast precursor cells.Therefore,reasonably restoring the hypoxic condition of bone microenvironment is essential for facilitating bone repair.Herein,we designed ROS scavenging and responsive prolonged oxygen-generating hydrogels(CPP-L/GelMA)as a“bone microenvironment regulative hydrogel”to reverse the hypoxic microenvironment in bone defects region.CPP-L/GelMA hydrogels comprises an antioxidant enzyme catalase(CAT)and ROS-responsive oxygen-releasing nanoparticles(PFC@PLGA/PPS)co-loaded liposome(CCP-L)and GelMA hydrogels.Under hypoxic condition,CPP-L/GelMA can release CAT for degrading hydrogen peroxide to generate oxygen and be triggered by superfluous ROS to continuously release the oxygen for more than 2 weeks.The prolonged oxygen enriched microenvironment generated by CPP-L/GelMA hydrogel significantly enhanced angiogenesis and osteogenesis while inhibited osteoclastogenesis.Finally,CPP-L/GelMA showed excellent bone regeneration effect in a mice skull defect model through the Nrf2-BMAL1-autophagy pathway.Hence,CPP-L/GelMA,as a bone microenvironment regulative hydrogel for bone tissue respiration,can effectively scavenge ROS and provide prolonged oxygen supply according to the demand in bone defect region,possessing of great clinical therapeutic potential.展开更多
针对快速变压吸附制氧浓度和回收率低问题,提出了用于提高产氧浓度和回收率的中间气两步充压的快速真空变压吸附流程,并对该流程进行了研究。结果表明:在快速真空变压吸附制氧过程中,中间气先在出气端充压可以有效提高产氧浓度,之后再...针对快速变压吸附制氧浓度和回收率低问题,提出了用于提高产氧浓度和回收率的中间气两步充压的快速真空变压吸附流程,并对该流程进行了研究。结果表明:在快速真空变压吸附制氧过程中,中间气先在出气端充压可以有效提高产氧浓度,之后再在进气端充压可提高氧气回收率。出气端充压前中间气压力及氧浓度和进气端充压后床层压力是影响产氧浓度和回收率提高的关键参数。当吸附和解吸压力分别为240、60 k Pa时,循环氧气回收率为34.57%,且每天产单位吨氧需吸附剂量为61.18 kg·TPD-1。展开更多
To further understand the effect of structural defects on the electrochemical and photocatalytic properties of TiO2, two synthetic approaches based on hydrothermal synthesis and post-synthetic chemical reduction to ac...To further understand the effect of structural defects on the electrochemical and photocatalytic properties of TiO2, two synthetic approaches based on hydrothermal synthesis and post-synthetic chemical reduction to achieve oxygen defect- implantation were developed herein. These approaches led to the formation of TiO2 nanorods with uniformly distributed defects in either the bulk or on the surface, or the combination of both, in the formed TiO2 nanorods （NRs）. Both approaches utilize unique TiN nanoparticles as the reaction precursor. Electron microscopy and Brunauer-Emmett-Teller （BET） analyses indicate that all the studied samples exhibit similar morphology and similar specific surface areas. X-ray photoelectron spectroscopy （XPS） and electron paramagnetic resonance （EPR） data confirm the existence of oxygen defects （Vo）. The photocatalytic properties of TiO2 with different types of implanted Vo were evaluated based on photocatalytic H2 production. By optimizing the concentration of Vo among the TiO2 NRs subjected to different treatments, significantly higher photocatalytic activities than that of the stoichiometric TiO2 NRs was achieved. The incident photon-to-current efficiency （IPCE） data indicate that the enhanced photocatalytic activity arises mainly from defect-assisted charge separation, which implies that photo-generated electrons or holes can be captured by Vo and suppress the charge recombination process. The results show that the defective TiO2 obtained by combining the two approaches exhibits the greatest photocatalytic activity enhancement amon~ all the samples.展开更多
测试了微型制氧吸附剂的平衡吸附特性,在此基础上选出适合快速真空变压吸附制氧的吸附剂.针对传统的单塔两步快速变压吸附制氧含量低问题,提出了提高产品气氧含量的单塔快速变压吸附制氧的排放气和原料气组合充压流程,并对该流程进行实...测试了微型制氧吸附剂的平衡吸附特性,在此基础上选出适合快速真空变压吸附制氧的吸附剂.针对传统的单塔两步快速变压吸附制氧含量低问题,提出了提高产品气氧含量的单塔快速变压吸附制氧的排放气和原料气组合充压流程,并对该流程进行实验研究.结果表明:在单塔快速真空变压吸附制氧过程中,采用排放气和原料气组合充压流程可以有效提高产品气氧含量.充压前排放气的压力和氧含量是影响产品气氧含量的关键参数,采取合适的排放气压力和较高氧含量的排放气可获得更高的产品气氧含量.在吸附和解吸压力分别为240 k Pa和60 k Pa时,采用排放气和原料气组合充压的快速真空变压吸附流程可获得氧体积分数90%的产品气,其产氧率为325.08 L·h-1·kg-1.展开更多
Inspired by erythrocytes that contain oxygen-carrying hemoglobin(Hb)and that exhibit photo-driven activity,we introduce homogenous-sized erythrocyte-like Hb microgel(μGel)systems(5-6μm)that can(i)emit heat,(ii)suppl...Inspired by erythrocytes that contain oxygen-carrying hemoglobin(Hb)and that exhibit photo-driven activity,we introduce homogenous-sized erythrocyte-like Hb microgel(μGel)systems(5-6μm)that can(i)emit heat,(ii)supply oxygen,and(iii)generate reactive oxygen species(ROS;1O2)in response to near-infrared(NIR)laser irradiation.Hb μGels consist of Hb,bovine serum albumin(BSA),chlorin e6(Ce6)and erbium@lutetium upconverting nanoparticles(UCNPs;~35 nm)that effectively convert 808 nm NIR light to 660 nm visible light.These Hb μGels are capable of releasing oxygen to help generate sufficient reactive oxygen species(^(1)O_(2))from UCNPs/Ce6 under severely hypoxic condition upon NIR stimulation for efficient photodynamic activity.Moreover,the Hb μGels emit heat and increase surface temperature due to NIR light absorption by heme(iron protoporphyrin IX)and display photothermal activity.By changing the Hb/UCNP/Ce6 ratio and controlling the amount of NIR laser irradiation,it is possible to formulate bespoke Hb μGels with either photothermal or photodynamic activity or both in the context of combined therapeutic effect.These Hb μGels effectively suppress highly hypoxic 4T1 cell spheroid growth and xenograft mice tumors in vivo.展开更多
Amultifunctional liposomal polydopamine nanoparticle(MPM@Lipo)was designed in this study,to combine chemotherapy,photothermal therapy(PTT)and oxygen enrichment to clear hyperproliferating inflammatory cells and improv...Amultifunctional liposomal polydopamine nanoparticle(MPM@Lipo)was designed in this study,to combine chemotherapy,photothermal therapy(PTT)and oxygen enrichment to clear hyperproliferating inflammatory cells and improve the hypoxic microenvironment for rheumatoid arthritis(RA)treatment.MPM@Lipo significantly scavenged intracellular reactive oxygen species and relieved joint hypoxia,thus contributing to the repolarization of M1 macrophages into M2 phenotype.Furthermore,MPM@Lipo could accumulate at inflammatory joints,inhibit the production of inflammatory factors,and protect cartilage in vivo,effectively alleviating RA progression in a rat adjuvant-induced arthritis model.Moreover,upon laser irradiation,MPM@Lipo can elevate the temperature to not only significantly obliterate excessively proliferating inflammatory cells but also accelerate the production of methotrexate and oxygen,resulting in excellent RA treatment effects.Overall,the use of synergistic chemotherapy/PTT/oxygen enrichment therapy to treat RA is a powerful potential strategy.展开更多
The oxygen evolution reaction(OER)is a crucial step in metal-air batteries and water splitting technologies,playing a significant role in the efficiency and achievable heights of these two technologies.However,the OER...The oxygen evolution reaction(OER)is a crucial step in metal-air batteries and water splitting technologies,playing a significant role in the efficiency and achievable heights of these two technologies.However,the OER is a four-step,four-electron reaction,and its slow kinetics result in high overpotentials,posing a challenge.To address this issue,numerous strategies involving modified catalysts have been proposed and proven to be highly efficient.In these strategies,the introduction of strain has been widely reported because it is generally believed to effectively regulate the electronic structure of metal sites and alter the adsorption energy of catalyst surfaces with reaction intermediates.However,strain has many other effects that are not well known,making it an important yet unexplored area.Based on this,this review provides a detailed introduction to the various roles of strain in OER.To better explain these roles,the review also presents the definition of strain and elucidates the potential mechanisms of strain in OER based on the d-band center theory and adsorption volcano plot.Additionally,the review showcases various ways of introducing strain in OER through examples reported in the latest literature,aiming to provide a comprehensive perspective for the development of strain engineering.Finally,the review analyzes the appropriate proportion of strain introduction,compares compressive and tensile strain,and examines the impact of strain on stability.And the review offers prospects for future research directions in this emerging field.展开更多
基金supported by National Science Foundation of China(Grant No.32271409,82002370,31800806)National Basic Research Program of China(2021YFA1201404)+5 种基金China Postdoctoral Science Foundation(Grant No.2019M661806)Major Project of NSFC(81991514)Natural Science Foundation of Jiangsu Province(Grant No.BK20200117)Jiangsu postdoctoral research support project(Grant No.2021K059A)Program of Innovation and Entrepreneurship of Jiangsu Province,Jiangsu Provincial Key Medical Center Foundation,Jiangsu Provincial Medical Outstanding Talent Foundation,Jiangsu Provincial Medical Youth Talent Foundation and Jiangsu Provincial Key Medical Talent Foundation,the Fundamental Research Funds for the Central Universities(14380493,14380494)Changzhou Sci&Tech Program(Grant No.CJ20220103).
文摘Large bone defects resulting from fractures and disease are a major clinical challenge,being often unable to heal spontaneously by the body’s repair mechanisms.Lines of evidence have shown that hypoxia-induced overproduction of ROS in bone defect region has a major impact on delaying bone regeneration.However,replenishing excess oxygen in a short time cause high oxygen tension that affect the activity of osteoblast precursor cells.Therefore,reasonably restoring the hypoxic condition of bone microenvironment is essential for facilitating bone repair.Herein,we designed ROS scavenging and responsive prolonged oxygen-generating hydrogels(CPP-L/GelMA)as a“bone microenvironment regulative hydrogel”to reverse the hypoxic microenvironment in bone defects region.CPP-L/GelMA hydrogels comprises an antioxidant enzyme catalase(CAT)and ROS-responsive oxygen-releasing nanoparticles(PFC@PLGA/PPS)co-loaded liposome(CCP-L)and GelMA hydrogels.Under hypoxic condition,CPP-L/GelMA can release CAT for degrading hydrogen peroxide to generate oxygen and be triggered by superfluous ROS to continuously release the oxygen for more than 2 weeks.The prolonged oxygen enriched microenvironment generated by CPP-L/GelMA hydrogel significantly enhanced angiogenesis and osteogenesis while inhibited osteoclastogenesis.Finally,CPP-L/GelMA showed excellent bone regeneration effect in a mice skull defect model through the Nrf2-BMAL1-autophagy pathway.Hence,CPP-L/GelMA,as a bone microenvironment regulative hydrogel for bone tissue respiration,can effectively scavenge ROS and provide prolonged oxygen supply according to the demand in bone defect region,possessing of great clinical therapeutic potential.
文摘针对快速变压吸附制氧浓度和回收率低问题,提出了用于提高产氧浓度和回收率的中间气两步充压的快速真空变压吸附流程,并对该流程进行了研究。结果表明:在快速真空变压吸附制氧过程中,中间气先在出气端充压可以有效提高产氧浓度,之后再在进气端充压可提高氧气回收率。出气端充压前中间气压力及氧浓度和进气端充压后床层压力是影响产氧浓度和回收率提高的关键参数。当吸附和解吸压力分别为240、60 k Pa时,循环氧气回收率为34.57%,且每天产单位吨氧需吸附剂量为61.18 kg·TPD-1。
文摘To further understand the effect of structural defects on the electrochemical and photocatalytic properties of TiO2, two synthetic approaches based on hydrothermal synthesis and post-synthetic chemical reduction to achieve oxygen defect- implantation were developed herein. These approaches led to the formation of TiO2 nanorods with uniformly distributed defects in either the bulk or on the surface, or the combination of both, in the formed TiO2 nanorods （NRs）. Both approaches utilize unique TiN nanoparticles as the reaction precursor. Electron microscopy and Brunauer-Emmett-Teller （BET） analyses indicate that all the studied samples exhibit similar morphology and similar specific surface areas. X-ray photoelectron spectroscopy （XPS） and electron paramagnetic resonance （EPR） data confirm the existence of oxygen defects （Vo）. The photocatalytic properties of TiO2 with different types of implanted Vo were evaluated based on photocatalytic H2 production. By optimizing the concentration of Vo among the TiO2 NRs subjected to different treatments, significantly higher photocatalytic activities than that of the stoichiometric TiO2 NRs was achieved. The incident photon-to-current efficiency （IPCE） data indicate that the enhanced photocatalytic activity arises mainly from defect-assisted charge separation, which implies that photo-generated electrons or holes can be captured by Vo and suppress the charge recombination process. The results show that the defective TiO2 obtained by combining the two approaches exhibits the greatest photocatalytic activity enhancement amon~ all the samples.
文摘测试了微型制氧吸附剂的平衡吸附特性,在此基础上选出适合快速真空变压吸附制氧的吸附剂.针对传统的单塔两步快速变压吸附制氧含量低问题,提出了提高产品气氧含量的单塔快速变压吸附制氧的排放气和原料气组合充压流程,并对该流程进行实验研究.结果表明:在单塔快速真空变压吸附制氧过程中,采用排放气和原料气组合充压流程可以有效提高产品气氧含量.充压前排放气的压力和氧含量是影响产品气氧含量的关键参数,采取合适的排放气压力和较高氧含量的排放气可获得更高的产品气氧含量.在吸附和解吸压力分别为240 k Pa和60 k Pa时,采用排放气和原料气组合充压的快速真空变压吸附流程可获得氧体积分数90%的产品气,其产氧率为325.08 L·h-1·kg-1.
基金This work was supported by a National Research Foundation of Korea(NRF)grants funded by the Korean government(No.NRF-2019R1A5A2027340)the Bio&Medical Technology Development Program of the National Research Foundation(NRF)funded by the Korean government(MSIT)(No.NRF-2022M3A9G8017220).
文摘Inspired by erythrocytes that contain oxygen-carrying hemoglobin(Hb)and that exhibit photo-driven activity,we introduce homogenous-sized erythrocyte-like Hb microgel(μGel)systems(5-6μm)that can(i)emit heat,(ii)supply oxygen,and(iii)generate reactive oxygen species(ROS;1O2)in response to near-infrared(NIR)laser irradiation.Hb μGels consist of Hb,bovine serum albumin(BSA),chlorin e6(Ce6)and erbium@lutetium upconverting nanoparticles(UCNPs;~35 nm)that effectively convert 808 nm NIR light to 660 nm visible light.These Hb μGels are capable of releasing oxygen to help generate sufficient reactive oxygen species(^(1)O_(2))from UCNPs/Ce6 under severely hypoxic condition upon NIR stimulation for efficient photodynamic activity.Moreover,the Hb μGels emit heat and increase surface temperature due to NIR light absorption by heme(iron protoporphyrin IX)and display photothermal activity.By changing the Hb/UCNP/Ce6 ratio and controlling the amount of NIR laser irradiation,it is possible to formulate bespoke Hb μGels with either photothermal or photodynamic activity or both in the context of combined therapeutic effect.These Hb μGels effectively suppress highly hypoxic 4T1 cell spheroid growth and xenograft mice tumors in vivo.
文摘Amultifunctional liposomal polydopamine nanoparticle(MPM@Lipo)was designed in this study,to combine chemotherapy,photothermal therapy(PTT)and oxygen enrichment to clear hyperproliferating inflammatory cells and improve the hypoxic microenvironment for rheumatoid arthritis(RA)treatment.MPM@Lipo significantly scavenged intracellular reactive oxygen species and relieved joint hypoxia,thus contributing to the repolarization of M1 macrophages into M2 phenotype.Furthermore,MPM@Lipo could accumulate at inflammatory joints,inhibit the production of inflammatory factors,and protect cartilage in vivo,effectively alleviating RA progression in a rat adjuvant-induced arthritis model.Moreover,upon laser irradiation,MPM@Lipo can elevate the temperature to not only significantly obliterate excessively proliferating inflammatory cells but also accelerate the production of methotrexate and oxygen,resulting in excellent RA treatment effects.Overall,the use of synergistic chemotherapy/PTT/oxygen enrichment therapy to treat RA is a powerful potential strategy.
基金financially supported by the National Natural Science Foundation of China(52071072)the Fundamental Research Funds for the Central Universities(2023GFZD03)+4 种基金the Natural Science Foundation-Steel,the Iron Foundation of Hebei Province(E2022501030)the Key Research and Development Plan of Qinhuangdao City(202302B013)the Liaoning Applied Basic Research Program(2023JH2/101300011)the Basic scientific research project of Liaoning Province Department of Education(LJKZZ20220024)the Shenyang Science and Technology Project(23-407-3-13)。
文摘The oxygen evolution reaction(OER)is a crucial step in metal-air batteries and water splitting technologies,playing a significant role in the efficiency and achievable heights of these two technologies.However,the OER is a four-step,four-electron reaction,and its slow kinetics result in high overpotentials,posing a challenge.To address this issue,numerous strategies involving modified catalysts have been proposed and proven to be highly efficient.In these strategies,the introduction of strain has been widely reported because it is generally believed to effectively regulate the electronic structure of metal sites and alter the adsorption energy of catalyst surfaces with reaction intermediates.However,strain has many other effects that are not well known,making it an important yet unexplored area.Based on this,this review provides a detailed introduction to the various roles of strain in OER.To better explain these roles,the review also presents the definition of strain and elucidates the potential mechanisms of strain in OER based on the d-band center theory and adsorption volcano plot.Additionally,the review showcases various ways of introducing strain in OER through examples reported in the latest literature,aiming to provide a comprehensive perspective for the development of strain engineering.Finally,the review analyzes the appropriate proportion of strain introduction,compares compressive and tensile strain,and examines the impact of strain on stability.And the review offers prospects for future research directions in this emerging field.
