To build a thrombosis risk assessment model applicable to oxygenators and investigate the effects of oxygenator external configuration and membrane filaments macroscopic parameters on the performances of cylindrical o...To build a thrombosis risk assessment model applicable to oxygenators and investigate the effects of oxygenator external configuration and membrane filaments macroscopic parameters on the performances of cylindrical oxygenators.A thrombosis driven by surface contact,shear stress,and anticoagulant drugs,and considering the effects of these factors on platelet,coagulation factor,and hemostatic protein function risk model was developed and validated with clinical oxygenators.The thrombosis model combined with a pressure loss model and an oxygen partial pressure model was used to assess the effect of the external structure and macroscopic parameters of the membrane filaments(height and thickness)on the performance of the cylindrical oxygenator.The cylindrical oxygenator center circular inflow manner and tangential outflow manner from the middle region of the outside benefit the overall performance of the oxygenator(reduced pressure loss and thrombosis risk).Increasing the radial thickness of the oxygenator membrane filaments significantly increased the oxygen exchange ability of the oxygenator and reduced the thrombosis risk compared to increasing the axial height,but with a smaller increase in pressure loss.Contact activation leading to thrombin production contributes significantly to oxygenator thrombosis.The oxygenator has little effect on platelet receptor function.Thrombosis in cylindrical oxygenators tends to form in the flow-flow/border impingement regions because of the high concentration of coagulation factors and long residence times in these regions.A thrombosis risk assessment model applicable to oxygenators was developed.We disclosed the mechanism of the impact of oxygenator external configuration and membrane filaments macroscopic parameters on its internal flow fields,the risk of thrombosis,and the efficiency of gas exchange,which are useful for the design and optimization of cylindrical oxygenators.展开更多
Extracorporeal membrane oxygenation(ECMO) has been developed for nearly 70 years,and it is the main technology to treat cardiopulmonary failure and continue to maintain life.As the core component of the ECMO system,th...Extracorporeal membrane oxygenation(ECMO) has been developed for nearly 70 years,and it is the main technology to treat cardiopulmonary failure and continue to maintain life.As the core component of the ECMO system,the gas exchange membrane possesses low gas permeability and plasma leakage at present.In addition,the membrane material exists low blood compatibility,causing the formation of thrombosis.Therefore,the membrane material with high gas permeability and blood compatibility are urgently needed.This paper summarizes the membrane development process,preparation method,and modification method.It provides a new idea for the preparation and coating modification as artificial lung membrane.展开更多
Extracorporeal membrane oxygenator(ECMO) has been in development for nearly 70 years, and the oxygenator has gone through several generations of optimizations, with advances from bubble oxygenators to membrane oxygena...Extracorporeal membrane oxygenator(ECMO) has been in development for nearly 70 years, and the oxygenator has gone through several generations of optimizations, with advances from bubble oxygenators to membrane oxygenators leading to more and more widespread use of ECMO. Membrane is the core of a ECMO system and the working mechanism of membrane oxygenator depends on the membrane material,from PDMS flat membrane to PMP hollow fiber membrane, which have experienced three generations.Blood compatibility on the surface of the membrane material is very vital, which directly determines the use duration of the oxygenator and can reduce the occurrence of complications. The mechanism of mass transfer is the basis of oxygenator operation and optimization. This review summarizes the membrane development history and preparation technology, modification approaches and mass transfer theory in the process of oxygen and blood exchange. We hoped that this review will provide more ideas for the study of gas blood exchange membrane.展开更多
Modeling for evaluation of effects of an indwelling hollow fiber oxygenator on the blood flow in human vena cava was carried out with involving an additional resistance term and variable vessel radius in the blood flo...Modeling for evaluation of effects of an indwelling hollow fiber oxygenator on the blood flow in human vena cava was carried out with involving an additional resistance term and variable vessel radius in the blood flow equation.The test of the stress-strain relationshiP of Pig′s vena cava was performed usingthe precise stress-strain instrument in our laboratory. The relationship between thecircumferential strain and stress of difrerent sections were introduced in determining the aditional resistance to the blood flow. An explicit difference method and iteration method were used to determine the additional pressure drop. The calculatedresults quantitatively reveal that the effect of the indwelling oxygenator on theblood flow is dependent upon the configuration of the oxygenator,the size of the vena cava vessel and its elasticity,and the blood flow,etc.. The low elastic modulus ofthe vena cava decreases the additional pressure drop significantly.展开更多
Introduction: World Health Organization announced on April 2009 a public health emergency of international concern caused by swine-origin influenza A(H1N1) virus. Acute respiratory distress syndrome(ARDS) has been rep...Introduction: World Health Organization announced on April 2009 a public health emergency of international concern caused by swine-origin influenza A(H1N1) virus. Acute respiratory distress syndrome(ARDS) has been reported to be the most devastating complications of this pathogen. Extracorporeal membrane oxygenator(ECMO) therapy for patients with H1N1 related ARDS has been described once all other therapeutic options have been exhausted. Here, we report the case of a child(German, male) with H1N1-associated fulminate respiratory and secondary hemodynamic deterioration who was rescued by initial emergent ECMO established through a dialysis catheter and subsequent switch to central cannulation following median sternotomy. This report highlights several important issues. First, it describes a successful use of a dialysis catheter for the establishment of a veno-venous ECMO in an emergency case by child. Second, it highlights the importance of a closely monitoring of clotting parameters during ECMOtherapy and third, if severe respiratory failure is complicated by cardiogenic shock, veno-atrial ECMO support via median sternotomy should be considered as a viable treatment option without further delay.展开更多
Mass transfer in a flat plate membrane oxygenator was studied and a convective mass transfer modelfor instantaeous reversible oxygenation of Cassonian fluid was presented. Numerical solution of the model canbe obtaine...Mass transfer in a flat plate membrane oxygenator was studied and a convective mass transfer modelfor instantaeous reversible oxygenation of Cassonian fluid was presented. Numerical solution of the model canbe obtained with finite difference method. When展开更多
Introduction: Extracorporeal Membrane Oxygenation (ECMO) is used in selected patient with cardiogenic and/or re- spiratory shock. We report our experience with standardized management protocols and the application of ...Introduction: Extracorporeal Membrane Oxygenation (ECMO) is used in selected patient with cardiogenic and/or re- spiratory shock. We report our experience with standardized management protocols and the application of the Qua- droxD oxygenator with a centrifugal pump to maximize end-organ recovery and improve survival. Methods: This is an Internal Review Board (IRB) approved, single institution retrospective study of end-organ recovery and survival in pa- tients who required ECMO for cardiogenic and/or respiratory shock between July 2010 and June 2011. Results: Sixteen patients (median age: 46 years) were initiated on either Veno-Arterial (VA) or Veno-Venous (VV) ECMO. Cardiogenic shock, acute respiratory distress syndrome (ARDS) and a combined respiratory and cardiogenic compromise were the primary indications for ECMO in 8 (50%), 5 (31%) and 3 (19%) patients respectively. The median time on ECMO was 8 days (range: 4 - 26 days). Twelve patients (75%) were successfully weaned off ECMO, of which four (25%) were bridged to a ventricular assist device (VAD) and eight (50%) were weaned to recovery. All eight patients (100%) that were weaned to recovery and two patients (50%) that were bridged to a VAD were successfully discharged from the hospital, resulting in a discharge rate of 63%. There was an improvement in pre- vs. post-ECMO AST (449 IU/L vs. 63 IU/L, p Conclusion: ECMO using the QuadroxD oxygenator and a centrifugal pump, coupled with standardized management protocols is beneficial in carefully selected patients. Improvement or main- tenance of end-organ function is associated with successful bridge to device therapy and/or increased survival.展开更多
Ischemia–reperfusion injury is a common pathophysiological mechanism in retinal degeneration.PANoptosis is a newly defined integral form of regulated cell death that combines the key features of pyroptosis,apoptosis,...Ischemia–reperfusion injury is a common pathophysiological mechanism in retinal degeneration.PANoptosis is a newly defined integral form of regulated cell death that combines the key features of pyroptosis,apoptosis,and necroptosis.Oligomerization of mitochondrial voltage-dependent anion channel 1 is an important pathological event in regulating cell death in retinal ischemia–reperfusion injury.However,its role in PANoptosis remains largely unknown.In this study,we demonstrated that voltage-dependent anion channel 1 oligomerization-mediated mitochondrial dysfunction was associated with PANoptosis in retinal ischemia–reperfusion injury.Inhibition of voltage-dependent anion channel 1 oligomerization suppressed mitochondrial dysfunction and PANoptosis in retinal cells subjected to ischemia–reperfusion injury.Mechanistically,mitochondria-derived reactive oxygen species played a central role in the voltagedependent anion channel 1-mediated regulation of PANoptosis by promoting PANoptosome assembly.Moreover,inhibiting voltage-dependent anion channel 1 oligomerization protected against PANoptosis in the retinas of rats subjected to ischemia–reperfusion injury.Overall,our findings reveal the critical role of voltage-dependent anion channel 1 oligomerization in regulating PANoptosis in retinal ischemia–reperfusion injury,highlighting voltage-dependent anion channel 1 as a promising therapeutic target.展开更多
Blood-brain barrier disruption and the neuroinflammatory response are significant pathological features that critically influence disease progression and treatment outcomes.This review systematically analyzes the curr...Blood-brain barrier disruption and the neuroinflammatory response are significant pathological features that critically influence disease progression and treatment outcomes.This review systematically analyzes the current understanding of the bidirectional relationship between blood-brain barrier disruption and neuroinflammation in traumatic brain injury,along with emerging combination therapeutic strategies.Literature review indicates that blood-brain barrier disruption and neuroinflammatory responses are key pathological features following traumatic brain injury.In the acute phase after traumatic brain injury,the pathological characteristics include primary blood-brain barrier disruption and the activation of inflammatory cascades.In the subacute phase,the pathological features are characterized by repair mechanisms and inflammatory modulation.In the chronic phase,the pathological features show persistent low-grade inflammation and incomplete recovery of the blood-brain barrier.Various physiological changes,such as structural alterations of the blood-brain barrier,inflammatory cascades,and extracellular matrix remodeling,interact with each other and are influenced by genetic,age,sex,and environmental factors.The dynamic balance between blood-brain barrier permeability and neuroinflammation is regulated by hormones,particularly sex hormones and stress-related hormones.Additionally,the role of gastrointestinal hormones is receiving increasing attention.Current treatment strategies for traumatic brain injury include various methods such as conventional drug combinations,multimodality neuromonitoring,hyperbaric oxygen therapy,and non-invasive brain stimulation.Artificial intelligence also shows potential in treatment decision-making and personalized therapy.Emerging sequential combination strategies and precision medicine approaches can help improve treatment outcomes;however,challenges remain,such as inadequate research on the mechanisms of the chronic phase traumatic brain injury and difficulties with technology integration.Future research on traumatic brain injury should focus on personalized treatment strategies,the standardization of techniques,costeffectiveness evaluations,and addressing the needs of patients with comorbidities.A multidisciplinary approach should be used to enhance treatment and improve patient outcomes.展开更多
A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and...A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and Mo2S3 nanoparticles were integrated at the edges of Co3O4 nanosheets,creating a rich,heterogeneous interface that enhances the synergistic effects of each component.In an alkaline electrolyte,the synthesized CoMoNiO-S/NF-110 exhibited superior electrocatalytic performance for oxygen evolution reaction(OER),achieving current densities of 100 and 200 mA·cm^(-2) with low overpotentials of 199.4 and 224.4 mV,respectively,outperforming RuO2 and several high-performance Mo and Ni-based catalysts.This excellent performance is attributed to the rich interface formed between the components and active sites exposed by the defect structure.展开更多
The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecul...The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecules and{[Co2(BINDI)(DMA)_(2)]·DMA}_(n)(Co-MOF,H4BINDI=N,N'-bis(5-isophthalic acid)naphthalenediimide,DMA=N,N-dimethylacetamide)was synthesized via a one-pot method,leveragingπ-πinteractions between pyrene and Co-MOF to modulate electrical conductivity.Results demonstrate that the Py@Co-MOF catalyst exhibited significantly enhanced OER performance compared to pure Co-MOF or pyrene-based electrodes,achieving an overpotential of 246 mV at a current density of 10 mA·cm^(-2) along with excellent stability.Density functional theory(DFT)calculations reveal that the formation of O*in the second step is the rate-determining step(RDS)during the OER process on Co-MOF,with an energy barrier of 0.85 eV due to the weak adsorption affinity of the OH*intermediate for Co sites.CCDC:2419276.展开更多
Exploring cost-effective and efficient catalysts for oxygen reduction reaction(ORR)poses a significant challenge,espe-cially in the pursuit of alternatives to precious metals like platinum.Significant advancements hav...Exploring cost-effective and efficient catalysts for oxygen reduction reaction(ORR)poses a significant challenge,espe-cially in the pursuit of alternatives to precious metals like platinum.Significant advancements have driven electrochem-ists to develop efficient ORR catalysts using abundant materials,particularly iron(Fe)-based,known for their exceptional performance in ORR.While the crucial function of Fe in boosting ORR catalytic activity is recognized,the connection between material attributes and catalytic performance remains enigmatic.Understanding the dynamic processes involved in oxygen electrocatalysis is paramount for designing precious-metals-free ORR electrocatalysts.Mössbauer spectroscopy stands out as a powerful technique for deciphering the structural characteristics of Fe species in catalysis,facilitating the identification of active sites and the clarification of catalytic mechanisms.By showcasing noteworthy case studies within this review,we demonstrate the application of in-situ/operando 57Fe Mössbauer spectroscopy across diverse Fe-involved materials in ORR catalysis.This sheds light on various aspects of ORR catalysis,such as identifying active sites,assessing stability,and understanding the reaction mechanism.Our inquiry drives towards the opportunities and hurdles associ-ated with Mössbauer spectroscopy,unveiling potential breakthroughs and avenues for enhancement within this pivotal research realm.展开更多
Proton exchange membrane fuel cells(PEMFCs)are considered as a promising renewable power source.However,the massive commercial application of PEMFCs has been greatly hindered by their high expense and less-satisfied p...Proton exchange membrane fuel cells(PEMFCs)are considered as a promising renewable power source.However,the massive commercial application of PEMFCs has been greatly hindered by their high expense and less-satisfied performance mainly due to the sluggish oxygen reduction reaction(ORR)kinetics even on state-of-the-art Pt catalyst.Octahedral PtNi nanoparticles(oct-PtNi NPs)with excellent ORR activity in a half-cell have been widely studied,while their performance in membrane electrode assembly(MEA)has much less reported.Herein,we investigated the MEA performance using the carbon supported oct-PtNi NPs(oct-PtNi/C)as the cathode catalyst.Under the mild acid washing condition,the surface Ni atoms of oct-PtNi/C were largely removed,and the performance of the MEA using the acid-leaching oct-PtNi/C(PNC-A)as the cathode catalyst was greatly improved.The maximum power density of the MEA reached 1.0 W·cm^(-2) with the cath-ode Pt loading of 0.2 mg·cm^(-2),which is 15%higher than that using Pt/C as the catalyst.After 30k cycles in the accelerated degradation test(ADT),the MEA using PNC-A as the catalyst showed a performance retention of 82%,higher than that of Pt/C(74%).The results reported here verify the possibility of using PNC-A as an advanced cathode catalyst in PEMFCs,thus enhancing the performance of PEMFCs while lowering the amount of expensive Pt.展开更多
Oxygen carriers play a fundamental role in chemical looping combustion(CLC).Iron-based carriers have been extensively investigated owing to their abundance and environmentally friendly.However,the reactivity and separ...Oxygen carriers play a fundamental role in chemical looping combustion(CLC).Iron-based carriers have been extensively investigated owing to their abundance and environmentally friendly.However,the reactivity and separability of iron-based carriers require further enhancement.This study investigates the effect of the concentration of Mn doping on reactivity,elastic properties and magnetic properties based on density functional theory(DFT)calculations.Theoretical results demonstrate that Mn doping effectively enhances reactivity by reducing the oxygen vacancy formation energy(E_(vac))from 2.33 to 0.87 eV.However,Mn doping introduces HV/EV Ms lattice distortions that deteriorate elastic properties,thereby reducing wear resistance,as evidenced by a 54.54%decrease in the hardness-to-Young's modulus ratio(H_(v)/E_(v))forα-Fe_(2)O_(3)and an 83.33%reduction for Fe_(3)O_(4).Furthermore,Mn doping also modifies magnetic properties.The maximum of saturation magnetization(M_(s))of Fe_(3)O_(4)reaches 121.02 emu/g at 33.33%Mn doping concentration.Finally,systematic evaluation identifies 33.33%as the optimal Mn doping concentration,achieving a balance in enhanced reactivity,superior magnetic performance,and retained elastic stability.展开更多
The escalating pace of industrialization has significantly intensified water pollution challenges,for instance,the persistent organic pollutants like methyl orange(MO).Conventional remediation techniques,such as adsor...The escalating pace of industrialization has significantly intensified water pollution challenges,for instance,the persistent organic pollutants like methyl orange(MO).Conventional remediation techniques,such as adsorption and biological degradation,are often hampered by low efficiency and the risk of secondary pollution.Photocatalysis emerges as a promising sustainable alternative;however,the benchmark material titanium dioxide(TiO_(2))suffers from its intrinsic limitations,notably its wide bandgap energy(≥3.4 eV)restricting its activity to the region of the ultraviolet light and its rapid recombination of photogenerated charge carriers.To overcome these constraints,this research focused on synthesizing novel TiO_(2)/Sn_(3)O_(4) heterojunction composite photocatalysts via a solvothermal approach.Comprehensive characterization techniques confirmed the successful formation of the composite,which revealed that ultrathin Sn3O4 nanosheets uniformly coated TiO_(2) nanospheres.This unique architecture effectively reduced the overall crystallinity and introduced the beneficial oxygen vacancies.Under visible-light irradiation(λ≥420 nm),the optimized TiO_(2)/Sn3O4 composite exhibited the exceptional photocatalytic performance,which achieved 96%degradation of MO within just 60 minutes.The calculated apparent kinetic rate constant(0.103 min^(-1))was remarkably(5.15 times)higher than that of pristine TiO_(2).ESR experiments identified that hydroxyl radicals(·OH)was the predominant active species driving the degradation.Furthermore,cyclic degradation tests demonstrated its excellent material stability,with the composite retaining 85%of its initial efficiency after four consecutive reuse cycles.This work underscored the synergistic effects within the TiO_(2)/Sn_(3)O_(4) heterojunction,which significantly enhanced the visible-light absorption,charge separation,and photocatalytic activity,which provided the valuable insights for designing efficient,stable catalysts for the advanced environmental remediation applications.展开更多
Developing efficient and durable electrocatalysts for acidic oxygen evolution reaction(OER)is pivotal for advancing proton exchange membrane water electrolysis(PEMWEs),yet balancing activity and stability remains a fo...Developing efficient and durable electrocatalysts for acidic oxygen evolution reaction(OER)is pivotal for advancing proton exchange membrane water electrolysis(PEMWEs),yet balancing activity and stability remains a formidable challenge.Herein,we propose a dual-engineering strategy to stabilize Ru-based catalysts by synergizing the oxygen vacancy site-synergized mechanism-lattice oxygen mechanism(OVSM-LOM)with Ru-N bond stabilization.The engineered RuO_(2)@NCC catalyst exhibits exceptional OER performance in 0.5 M H2SO4,achieving an ultralow overpotential of 215 mV at 10 mA cm^(-2) and prolonged stability for over 327 h.The catalyst delivers 300 h of continuous operation at 1 A cm^(-2),with a negligible degradation rate of only 0.067 mV h-1,further demonstrating its potential for practical application.Oxygen vacancies unlock the OVSM-LOM pathway,bypassing the sluggish adsorbate evolution mechanism(AEM)and accelerating reaction kinetics,while the Ru-N bonds suppress Ru dissolution by anchoring low-valent Ru centers.Quasi-in situ X-ray photoelectron spectroscopy(XPS),X-ray absorption spectroscopy(XAS),and isotopic labeling experiments confirm the lattice oxygen participation with *O formation as the rate-determining step.The Ru-N bonds reinforce the structural integrity by stabilizing low-valent Ru centers and inhibiting overoxidation.Theoretical calculations further verify that the synergistic interaction between OVs and Ru-O(N)active sites optimizes the Ru d-band center and stabilizes intermediates,while Ru-N coordination enhances structural integrity.This study establishes a novel paradigm for designing robust acidic OER catalysts through defect and coordination engineering,bridging the gap between activity and stability for sustainable energy technologies.展开更多
Lithium-oxygen(Li-O2)batteries are perceived as a promising breakthrough in sustainable electrochemical energy storage,utilizing ambient air as an energy source,eliminating the need for costly cathode materials,and of...Lithium-oxygen(Li-O2)batteries are perceived as a promising breakthrough in sustainable electrochemical energy storage,utilizing ambient air as an energy source,eliminating the need for costly cathode materials,and offering the highest theoretical energy density(~3.5 k Wh kg^(-1))among discussed candidates.Contributing to the poor cycle life of currently reported Li-O_(2)cells is singlet oxygen(1O_(2))formation,inducing parasitic reactions,degrading key components,and severely deteriorating cell performance.Here,we harness the chirality-induced spin selectivity effect of chiral cobalt oxide nanosheets(Co_(3)O_(4)NSs)as cathode materials to suppress 1O_(2)in Li-O_(2)batteries for the first time.Operando photoluminescence spectroscopy reveals a 3.7-fold and 3.23-fold reduction in 1O_(2)during discharge and charge,respectively,compared to conventional carbon paperbased cells,consistent with differential electrochemical mass spectrometry results,which indicate a near-theoretical charge-to-O_(2)ratio(2.04 e-/O_(2)).Density functional theory calculations demonstrate that chirality induces a peak shift near the Fermi level,enhancing Co 3d-O 2p hybridization,stabilizing reaction intermediates,and lowering activation barriers for Li_(2)O_(2)formation and decomposition.These findings establish a new strategy for improving the stability and energy efficiency of sustainable Li-O_(2)batteries,abridging the current gap to commercialization.展开更多
Magnetic field-driven spin polarization modulation has emerged as an effective way to boost the electrocatalytic oxygen evolution reaction(OER).However,the correlation among catalyst structure,magnetic property,and ma...Magnetic field-driven spin polarization modulation has emerged as an effective way to boost the electrocatalytic oxygen evolution reaction(OER).However,the correlation among catalyst structure,magnetic property,and magnetic field enhanced-electrochemical activity remains to be fully elucidated.Herein,single-domain CoFe_(2)O_(4) catalysts with tunable oxygen vacancies(CFO-V_(O)) were synthesized to probe how V_(O) mediates magnetism and OER activity under magnetic field.The introduction of V_(O) can simultaneously modulate saturation magnetization(M_(s)) and coercivity(H_(c)),where the increased M_(s) dominates the magnetic field-enhanced OER activity.Under a 14,000 G magnetic field,the optimized CFO-V_(O) exhibits up to 16.1 % reduction in overpotential and 365 % enhancement in magnetocurrent(MC).Electrochemical analyses and post-OER characterization reveal that the magnetic field synergistically improves OER kinetics through lattice distortion induction,magnetohydrodynamic effect,and spin charge transfer effect.Importantly,the magnetic field promotes additional Co^(3+) generation to compensate for charge imbalance caused by V_(O) filling,maintaining dynamic equilibrium of V_(O) and effective reactant adsorption-conversion processes.This work unveils the synergistic mechanism of V_(O) and magnetic parameters for enhancing OER performance under the magnetic field,providing new insights into the design of high-efficiency spinregulated OER catalysts.展开更多
After injury,bone tissue initiates a reparative response to restore its structure and function.The failure to initiate or delay this response could result in fracture nonunion.The molecular mechanisms underlying the o...After injury,bone tissue initiates a reparative response to restore its structure and function.The failure to initiate or delay this response could result in fracture nonunion.The molecular mechanisms underlying the occurrence of fracture nonunion are not yet established.We propose that hypoxia-triggered signaling pathways,mediated by reactive oxygen species(ROS)homeostasis,control Bmp2 expression and fracture healing initiation.The excessive ROS leads to oxidative stress and,ultimately,fracture nonunion.In this study,we silenced Apex1,the final ROS signaling transducer that mediates the activation of key transcription factors by their cysteines oxidoreduction,evaluating its role during endochondral ossification and fracture repair.Silencing Apex1 in limb bud mesenchyme results in transient metaphyseal dysplasia derived from impaired chondrocyte differentiation.During bone regeneration,Apex1 silencing induces a fracture nonunion phenotype,characterized by delayed fracture repair initiation,impaired periosteal response,and reduced chondrocyte and osteoblast differentiation.This compromised chondrocyte differentiation hampers callus vascularization and healing progression.Our findings highlight a critical mechanism where hypoxia-driven ROS signaling in mesenchymal progenitors through APEX1 is essential for fracture healing initiation.展开更多
Silica nanoparticles-stabilized cobalt and nitrogen-doped carbon materials were synthesized through pyrolysis of metal-organic-framework of ZIF-67 supported by silica nanoparticles.The experimental results reveal that...Silica nanoparticles-stabilized cobalt and nitrogen-doped carbon materials were synthesized through pyrolysis of metal-organic-framework of ZIF-67 supported by silica nanoparticles.The experimental results reveal that the introduction of the silica nanoparticles can stabilize the microstructure of the derived CoN-C materials,which in turn exhibits the promising electrocatalytic activity towards both oxygen reduction and oxygen evolution reactions.The optimized sample exhibits a better oxygen reduction activity than commercial Pt/C catalyst as confirmed by the positive shift of half-wave potential by 20 mV while it has a low overpotential of 273 mV for oxygen evolution reactions with the retained performance over 80%after 25,000 s of continuous operation.It is demonstrated that the introduction of support frame might be an effective way to improve the activity and stability of metal-organic-framework derived electrocatalyst with stabilized microstructure.展开更多
基金supported by the National Key R&D Program of China(Grant Nos.2020YFC0862904,2020YFC0862900,and 2020YFC0862902)the National Natural Science Foundation of China(Grant Nos.12372300,U23A20486,and 32071311)the Fundamental Research Funds for the Central Universities,and the Academic Excellence Foundation of BUAA for PhD Students.
文摘To build a thrombosis risk assessment model applicable to oxygenators and investigate the effects of oxygenator external configuration and membrane filaments macroscopic parameters on the performances of cylindrical oxygenators.A thrombosis driven by surface contact,shear stress,and anticoagulant drugs,and considering the effects of these factors on platelet,coagulation factor,and hemostatic protein function risk model was developed and validated with clinical oxygenators.The thrombosis model combined with a pressure loss model and an oxygen partial pressure model was used to assess the effect of the external structure and macroscopic parameters of the membrane filaments(height and thickness)on the performance of the cylindrical oxygenator.The cylindrical oxygenator center circular inflow manner and tangential outflow manner from the middle region of the outside benefit the overall performance of the oxygenator(reduced pressure loss and thrombosis risk).Increasing the radial thickness of the oxygenator membrane filaments significantly increased the oxygen exchange ability of the oxygenator and reduced the thrombosis risk compared to increasing the axial height,but with a smaller increase in pressure loss.Contact activation leading to thrombin production contributes significantly to oxygenator thrombosis.The oxygenator has little effect on platelet receptor function.Thrombosis in cylindrical oxygenators tends to form in the flow-flow/border impingement regions because of the high concentration of coagulation factors and long residence times in these regions.A thrombosis risk assessment model applicable to oxygenators was developed.We disclosed the mechanism of the impact of oxygenator external configuration and membrane filaments macroscopic parameters on its internal flow fields,the risk of thrombosis,and the efficiency of gas exchange,which are useful for the design and optimization of cylindrical oxygenators.
基金the support of this work by State Key Laboratory of Tribology in Advanced Equipment,Tsinghua University(61012205321)。
文摘Extracorporeal membrane oxygenation(ECMO) has been developed for nearly 70 years,and it is the main technology to treat cardiopulmonary failure and continue to maintain life.As the core component of the ECMO system,the gas exchange membrane possesses low gas permeability and plasma leakage at present.In addition,the membrane material exists low blood compatibility,causing the formation of thrombosis.Therefore,the membrane material with high gas permeability and blood compatibility are urgently needed.This paper summarizes the membrane development process,preparation method,and modification method.It provides a new idea for the preparation and coating modification as artificial lung membrane.
基金financial support of the National Key Research and Development Program of China (2020YFC0862903)the National Natural Science Foundation of China (22078146)+1 种基金the Key Research and Development program of Jiangsu Province (BE2021022)the Natural Science Foundation of Jiangsu Province (BK20200091)。
文摘Extracorporeal membrane oxygenator(ECMO) has been in development for nearly 70 years, and the oxygenator has gone through several generations of optimizations, with advances from bubble oxygenators to membrane oxygenators leading to more and more widespread use of ECMO. Membrane is the core of a ECMO system and the working mechanism of membrane oxygenator depends on the membrane material,from PDMS flat membrane to PMP hollow fiber membrane, which have experienced three generations.Blood compatibility on the surface of the membrane material is very vital, which directly determines the use duration of the oxygenator and can reduce the occurrence of complications. The mechanism of mass transfer is the basis of oxygenator operation and optimization. This review summarizes the membrane development history and preparation technology, modification approaches and mass transfer theory in the process of oxygen and blood exchange. We hoped that this review will provide more ideas for the study of gas blood exchange membrane.
文摘Modeling for evaluation of effects of an indwelling hollow fiber oxygenator on the blood flow in human vena cava was carried out with involving an additional resistance term and variable vessel radius in the blood flow equation.The test of the stress-strain relationshiP of Pig′s vena cava was performed usingthe precise stress-strain instrument in our laboratory. The relationship between thecircumferential strain and stress of difrerent sections were introduced in determining the aditional resistance to the blood flow. An explicit difference method and iteration method were used to determine the additional pressure drop. The calculatedresults quantitatively reveal that the effect of the indwelling oxygenator on theblood flow is dependent upon the configuration of the oxygenator,the size of the vena cava vessel and its elasticity,and the blood flow,etc.. The low elastic modulus ofthe vena cava decreases the additional pressure drop significantly.
文摘Introduction: World Health Organization announced on April 2009 a public health emergency of international concern caused by swine-origin influenza A(H1N1) virus. Acute respiratory distress syndrome(ARDS) has been reported to be the most devastating complications of this pathogen. Extracorporeal membrane oxygenator(ECMO) therapy for patients with H1N1 related ARDS has been described once all other therapeutic options have been exhausted. Here, we report the case of a child(German, male) with H1N1-associated fulminate respiratory and secondary hemodynamic deterioration who was rescued by initial emergent ECMO established through a dialysis catheter and subsequent switch to central cannulation following median sternotomy. This report highlights several important issues. First, it describes a successful use of a dialysis catheter for the establishment of a veno-venous ECMO in an emergency case by child. Second, it highlights the importance of a closely monitoring of clotting parameters during ECMOtherapy and third, if severe respiratory failure is complicated by cardiogenic shock, veno-atrial ECMO support via median sternotomy should be considered as a viable treatment option without further delay.
基金The paper was presented in the lst National Rheology Conference of China and was supported by NatiOnal Natural Science Foundation of China.
文摘Mass transfer in a flat plate membrane oxygenator was studied and a convective mass transfer modelfor instantaeous reversible oxygenation of Cassonian fluid was presented. Numerical solution of the model canbe obtained with finite difference method. When
文摘Introduction: Extracorporeal Membrane Oxygenation (ECMO) is used in selected patient with cardiogenic and/or re- spiratory shock. We report our experience with standardized management protocols and the application of the Qua- droxD oxygenator with a centrifugal pump to maximize end-organ recovery and improve survival. Methods: This is an Internal Review Board (IRB) approved, single institution retrospective study of end-organ recovery and survival in pa- tients who required ECMO for cardiogenic and/or respiratory shock between July 2010 and June 2011. Results: Sixteen patients (median age: 46 years) were initiated on either Veno-Arterial (VA) or Veno-Venous (VV) ECMO. Cardiogenic shock, acute respiratory distress syndrome (ARDS) and a combined respiratory and cardiogenic compromise were the primary indications for ECMO in 8 (50%), 5 (31%) and 3 (19%) patients respectively. The median time on ECMO was 8 days (range: 4 - 26 days). Twelve patients (75%) were successfully weaned off ECMO, of which four (25%) were bridged to a ventricular assist device (VAD) and eight (50%) were weaned to recovery. All eight patients (100%) that were weaned to recovery and two patients (50%) that were bridged to a VAD were successfully discharged from the hospital, resulting in a discharge rate of 63%. There was an improvement in pre- vs. post-ECMO AST (449 IU/L vs. 63 IU/L, p Conclusion: ECMO using the QuadroxD oxygenator and a centrifugal pump, coupled with standardized management protocols is beneficial in carefully selected patients. Improvement or main- tenance of end-organ function is associated with successful bridge to device therapy and/or increased survival.
基金supported by the National Natural Science Foundation of China,Nos.82172196(to KX),82372507(to KX)the Natural Science Foundation of Hunan Province,China,No.2023JJ40804(to QZ)the Key Laboratory of Emergency and Trauma(Hainan Medical University)of the Ministry of Education,China,No.KLET-202210(to QZ)。
文摘Ischemia–reperfusion injury is a common pathophysiological mechanism in retinal degeneration.PANoptosis is a newly defined integral form of regulated cell death that combines the key features of pyroptosis,apoptosis,and necroptosis.Oligomerization of mitochondrial voltage-dependent anion channel 1 is an important pathological event in regulating cell death in retinal ischemia–reperfusion injury.However,its role in PANoptosis remains largely unknown.In this study,we demonstrated that voltage-dependent anion channel 1 oligomerization-mediated mitochondrial dysfunction was associated with PANoptosis in retinal ischemia–reperfusion injury.Inhibition of voltage-dependent anion channel 1 oligomerization suppressed mitochondrial dysfunction and PANoptosis in retinal cells subjected to ischemia–reperfusion injury.Mechanistically,mitochondria-derived reactive oxygen species played a central role in the voltagedependent anion channel 1-mediated regulation of PANoptosis by promoting PANoptosome assembly.Moreover,inhibiting voltage-dependent anion channel 1 oligomerization protected against PANoptosis in the retinas of rats subjected to ischemia–reperfusion injury.Overall,our findings reveal the critical role of voltage-dependent anion channel 1 oligomerization in regulating PANoptosis in retinal ischemia–reperfusion injury,highlighting voltage-dependent anion channel 1 as a promising therapeutic target.
基金supported by Open Scientific Research Program of Military Logistics,No.BLB20J009(to YZhao).
文摘Blood-brain barrier disruption and the neuroinflammatory response are significant pathological features that critically influence disease progression and treatment outcomes.This review systematically analyzes the current understanding of the bidirectional relationship between blood-brain barrier disruption and neuroinflammation in traumatic brain injury,along with emerging combination therapeutic strategies.Literature review indicates that blood-brain barrier disruption and neuroinflammatory responses are key pathological features following traumatic brain injury.In the acute phase after traumatic brain injury,the pathological characteristics include primary blood-brain barrier disruption and the activation of inflammatory cascades.In the subacute phase,the pathological features are characterized by repair mechanisms and inflammatory modulation.In the chronic phase,the pathological features show persistent low-grade inflammation and incomplete recovery of the blood-brain barrier.Various physiological changes,such as structural alterations of the blood-brain barrier,inflammatory cascades,and extracellular matrix remodeling,interact with each other and are influenced by genetic,age,sex,and environmental factors.The dynamic balance between blood-brain barrier permeability and neuroinflammation is regulated by hormones,particularly sex hormones and stress-related hormones.Additionally,the role of gastrointestinal hormones is receiving increasing attention.Current treatment strategies for traumatic brain injury include various methods such as conventional drug combinations,multimodality neuromonitoring,hyperbaric oxygen therapy,and non-invasive brain stimulation.Artificial intelligence also shows potential in treatment decision-making and personalized therapy.Emerging sequential combination strategies and precision medicine approaches can help improve treatment outcomes;however,challenges remain,such as inadequate research on the mechanisms of the chronic phase traumatic brain injury and difficulties with technology integration.Future research on traumatic brain injury should focus on personalized treatment strategies,the standardization of techniques,costeffectiveness evaluations,and addressing the needs of patients with comorbidities.A multidisciplinary approach should be used to enhance treatment and improve patient outcomes.
文摘A composite electrocatalyst,CoMoNiO-S/NF-110(NF is nickel foam),was synthesized through electrodeposition,followed by pyrolysis and then the vulcanization process.CoMoNiO-S/NF-110 exhibited a structure where Ni3S2 and Mo2S3 nanoparticles were integrated at the edges of Co3O4 nanosheets,creating a rich,heterogeneous interface that enhances the synergistic effects of each component.In an alkaline electrolyte,the synthesized CoMoNiO-S/NF-110 exhibited superior electrocatalytic performance for oxygen evolution reaction(OER),achieving current densities of 100 and 200 mA·cm^(-2) with low overpotentials of 199.4 and 224.4 mV,respectively,outperforming RuO2 and several high-performance Mo and Ni-based catalysts.This excellent performance is attributed to the rich interface formed between the components and active sites exposed by the defect structure.
文摘The poor electrical conductivity of metal-organic frameworks(MOFs)limits their electrocatalytic performance in the oxygen evolution reaction(OER).In this study,a Py@Co-MOF composite material based on pyrene(Py)molecules and{[Co2(BINDI)(DMA)_(2)]·DMA}_(n)(Co-MOF,H4BINDI=N,N'-bis(5-isophthalic acid)naphthalenediimide,DMA=N,N-dimethylacetamide)was synthesized via a one-pot method,leveragingπ-πinteractions between pyrene and Co-MOF to modulate electrical conductivity.Results demonstrate that the Py@Co-MOF catalyst exhibited significantly enhanced OER performance compared to pure Co-MOF or pyrene-based electrodes,achieving an overpotential of 246 mV at a current density of 10 mA·cm^(-2) along with excellent stability.Density functional theory(DFT)calculations reveal that the formation of O*in the second step is the rate-determining step(RDS)during the OER process on Co-MOF,with an energy barrier of 0.85 eV due to the weak adsorption affinity of the OH*intermediate for Co sites.CCDC:2419276.
基金financially supported by the National Natural Science Foundation of China (22350410386,W2412116,22375200,U22A202175,21961142006)。
文摘Exploring cost-effective and efficient catalysts for oxygen reduction reaction(ORR)poses a significant challenge,espe-cially in the pursuit of alternatives to precious metals like platinum.Significant advancements have driven electrochem-ists to develop efficient ORR catalysts using abundant materials,particularly iron(Fe)-based,known for their exceptional performance in ORR.While the crucial function of Fe in boosting ORR catalytic activity is recognized,the connection between material attributes and catalytic performance remains enigmatic.Understanding the dynamic processes involved in oxygen electrocatalysis is paramount for designing precious-metals-free ORR electrocatalysts.Mössbauer spectroscopy stands out as a powerful technique for deciphering the structural characteristics of Fe species in catalysis,facilitating the identification of active sites and the clarification of catalytic mechanisms.By showcasing noteworthy case studies within this review,we demonstrate the application of in-situ/operando 57Fe Mössbauer spectroscopy across diverse Fe-involved materials in ORR catalysis.This sheds light on various aspects of ORR catalysis,such as identifying active sites,assessing stability,and understanding the reaction mechanism.Our inquiry drives towards the opportunities and hurdles associ-ated with Mössbauer spectroscopy,unveiling potential breakthroughs and avenues for enhancement within this pivotal research realm.
基金supported by grants from the Natural Science Foundation of China(22362031 and 21805121)the Science and Technology Project of Yunnan Province(2019FD137)。
文摘Proton exchange membrane fuel cells(PEMFCs)are considered as a promising renewable power source.However,the massive commercial application of PEMFCs has been greatly hindered by their high expense and less-satisfied performance mainly due to the sluggish oxygen reduction reaction(ORR)kinetics even on state-of-the-art Pt catalyst.Octahedral PtNi nanoparticles(oct-PtNi NPs)with excellent ORR activity in a half-cell have been widely studied,while their performance in membrane electrode assembly(MEA)has much less reported.Herein,we investigated the MEA performance using the carbon supported oct-PtNi NPs(oct-PtNi/C)as the cathode catalyst.Under the mild acid washing condition,the surface Ni atoms of oct-PtNi/C were largely removed,and the performance of the MEA using the acid-leaching oct-PtNi/C(PNC-A)as the cathode catalyst was greatly improved.The maximum power density of the MEA reached 1.0 W·cm^(-2) with the cath-ode Pt loading of 0.2 mg·cm^(-2),which is 15%higher than that using Pt/C as the catalyst.After 30k cycles in the accelerated degradation test(ADT),the MEA using PNC-A as the catalyst showed a performance retention of 82%,higher than that of Pt/C(74%).The results reported here verify the possibility of using PNC-A as an advanced cathode catalyst in PEMFCs,thus enhancing the performance of PEMFCs while lowering the amount of expensive Pt.
基金Supported by National Natural Science Foundation of China(50976032,51776070)。
文摘Oxygen carriers play a fundamental role in chemical looping combustion(CLC).Iron-based carriers have been extensively investigated owing to their abundance and environmentally friendly.However,the reactivity and separability of iron-based carriers require further enhancement.This study investigates the effect of the concentration of Mn doping on reactivity,elastic properties and magnetic properties based on density functional theory(DFT)calculations.Theoretical results demonstrate that Mn doping effectively enhances reactivity by reducing the oxygen vacancy formation energy(E_(vac))from 2.33 to 0.87 eV.However,Mn doping introduces HV/EV Ms lattice distortions that deteriorate elastic properties,thereby reducing wear resistance,as evidenced by a 54.54%decrease in the hardness-to-Young's modulus ratio(H_(v)/E_(v))forα-Fe_(2)O_(3)and an 83.33%reduction for Fe_(3)O_(4).Furthermore,Mn doping also modifies magnetic properties.The maximum of saturation magnetization(M_(s))of Fe_(3)O_(4)reaches 121.02 emu/g at 33.33%Mn doping concentration.Finally,systematic evaluation identifies 33.33%as the optimal Mn doping concentration,achieving a balance in enhanced reactivity,superior magnetic performance,and retained elastic stability.
文摘The escalating pace of industrialization has significantly intensified water pollution challenges,for instance,the persistent organic pollutants like methyl orange(MO).Conventional remediation techniques,such as adsorption and biological degradation,are often hampered by low efficiency and the risk of secondary pollution.Photocatalysis emerges as a promising sustainable alternative;however,the benchmark material titanium dioxide(TiO_(2))suffers from its intrinsic limitations,notably its wide bandgap energy(≥3.4 eV)restricting its activity to the region of the ultraviolet light and its rapid recombination of photogenerated charge carriers.To overcome these constraints,this research focused on synthesizing novel TiO_(2)/Sn_(3)O_(4) heterojunction composite photocatalysts via a solvothermal approach.Comprehensive characterization techniques confirmed the successful formation of the composite,which revealed that ultrathin Sn3O4 nanosheets uniformly coated TiO_(2) nanospheres.This unique architecture effectively reduced the overall crystallinity and introduced the beneficial oxygen vacancies.Under visible-light irradiation(λ≥420 nm),the optimized TiO_(2)/Sn3O4 composite exhibited the exceptional photocatalytic performance,which achieved 96%degradation of MO within just 60 minutes.The calculated apparent kinetic rate constant(0.103 min^(-1))was remarkably(5.15 times)higher than that of pristine TiO_(2).ESR experiments identified that hydroxyl radicals(·OH)was the predominant active species driving the degradation.Furthermore,cyclic degradation tests demonstrated its excellent material stability,with the composite retaining 85%of its initial efficiency after four consecutive reuse cycles.This work underscored the synergistic effects within the TiO_(2)/Sn_(3)O_(4) heterojunction,which significantly enhanced the visible-light absorption,charge separation,and photocatalytic activity,which provided the valuable insights for designing efficient,stable catalysts for the advanced environmental remediation applications.
基金support from the National Natural Science Foundation of China(Nos.12305373 and 52276220)the Guangzhou Basic Research Program(No.SL2024A04J00234).
文摘Developing efficient and durable electrocatalysts for acidic oxygen evolution reaction(OER)is pivotal for advancing proton exchange membrane water electrolysis(PEMWEs),yet balancing activity and stability remains a formidable challenge.Herein,we propose a dual-engineering strategy to stabilize Ru-based catalysts by synergizing the oxygen vacancy site-synergized mechanism-lattice oxygen mechanism(OVSM-LOM)with Ru-N bond stabilization.The engineered RuO_(2)@NCC catalyst exhibits exceptional OER performance in 0.5 M H2SO4,achieving an ultralow overpotential of 215 mV at 10 mA cm^(-2) and prolonged stability for over 327 h.The catalyst delivers 300 h of continuous operation at 1 A cm^(-2),with a negligible degradation rate of only 0.067 mV h-1,further demonstrating its potential for practical application.Oxygen vacancies unlock the OVSM-LOM pathway,bypassing the sluggish adsorbate evolution mechanism(AEM)and accelerating reaction kinetics,while the Ru-N bonds suppress Ru dissolution by anchoring low-valent Ru centers.Quasi-in situ X-ray photoelectron spectroscopy(XPS),X-ray absorption spectroscopy(XAS),and isotopic labeling experiments confirm the lattice oxygen participation with *O formation as the rate-determining step.The Ru-N bonds reinforce the structural integrity by stabilizing low-valent Ru centers and inhibiting overoxidation.Theoretical calculations further verify that the synergistic interaction between OVs and Ru-O(N)active sites optimizes the Ru d-band center and stabilizes intermediates,while Ru-N coordination enhances structural integrity.This study establishes a novel paradigm for designing robust acidic OER catalysts through defect and coordination engineering,bridging the gap between activity and stability for sustainable energy technologies.
基金supported by Basic Science Research Program(Priority Research Institute)through the NRF of Korea funded by the Ministry of Education(2021R1A6A1A10039823)by the Korea Basic Science Institute(National Research Facilities and Equipment Center)grant funded by the Ministry of Education(2020R1A6C101B194)。
文摘Lithium-oxygen(Li-O2)batteries are perceived as a promising breakthrough in sustainable electrochemical energy storage,utilizing ambient air as an energy source,eliminating the need for costly cathode materials,and offering the highest theoretical energy density(~3.5 k Wh kg^(-1))among discussed candidates.Contributing to the poor cycle life of currently reported Li-O_(2)cells is singlet oxygen(1O_(2))formation,inducing parasitic reactions,degrading key components,and severely deteriorating cell performance.Here,we harness the chirality-induced spin selectivity effect of chiral cobalt oxide nanosheets(Co_(3)O_(4)NSs)as cathode materials to suppress 1O_(2)in Li-O_(2)batteries for the first time.Operando photoluminescence spectroscopy reveals a 3.7-fold and 3.23-fold reduction in 1O_(2)during discharge and charge,respectively,compared to conventional carbon paperbased cells,consistent with differential electrochemical mass spectrometry results,which indicate a near-theoretical charge-to-O_(2)ratio(2.04 e-/O_(2)).Density functional theory calculations demonstrate that chirality induces a peak shift near the Fermi level,enhancing Co 3d-O 2p hybridization,stabilizing reaction intermediates,and lowering activation barriers for Li_(2)O_(2)formation and decomposition.These findings establish a new strategy for improving the stability and energy efficiency of sustainable Li-O_(2)batteries,abridging the current gap to commercialization.
基金supported by the “Climbing Plan” of Harbin Normal University (No.XKB202301)National Natural Science Foundation of China (Nos.21871065 and 22071038)。
文摘Magnetic field-driven spin polarization modulation has emerged as an effective way to boost the electrocatalytic oxygen evolution reaction(OER).However,the correlation among catalyst structure,magnetic property,and magnetic field enhanced-electrochemical activity remains to be fully elucidated.Herein,single-domain CoFe_(2)O_(4) catalysts with tunable oxygen vacancies(CFO-V_(O)) were synthesized to probe how V_(O) mediates magnetism and OER activity under magnetic field.The introduction of V_(O) can simultaneously modulate saturation magnetization(M_(s)) and coercivity(H_(c)),where the increased M_(s) dominates the magnetic field-enhanced OER activity.Under a 14,000 G magnetic field,the optimized CFO-V_(O) exhibits up to 16.1 % reduction in overpotential and 365 % enhancement in magnetocurrent(MC).Electrochemical analyses and post-OER characterization reveal that the magnetic field synergistically improves OER kinetics through lattice distortion induction,magnetohydrodynamic effect,and spin charge transfer effect.Importantly,the magnetic field promotes additional Co^(3+) generation to compensate for charge imbalance caused by V_(O) filling,maintaining dynamic equilibrium of V_(O) and effective reactant adsorption-conversion processes.This work unveils the synergistic mechanism of V_(O) and magnetic parameters for enhancing OER performance under the magnetic field,providing new insights into the design of high-efficiency spinregulated OER catalysts.
文摘After injury,bone tissue initiates a reparative response to restore its structure and function.The failure to initiate or delay this response could result in fracture nonunion.The molecular mechanisms underlying the occurrence of fracture nonunion are not yet established.We propose that hypoxia-triggered signaling pathways,mediated by reactive oxygen species(ROS)homeostasis,control Bmp2 expression and fracture healing initiation.The excessive ROS leads to oxidative stress and,ultimately,fracture nonunion.In this study,we silenced Apex1,the final ROS signaling transducer that mediates the activation of key transcription factors by their cysteines oxidoreduction,evaluating its role during endochondral ossification and fracture repair.Silencing Apex1 in limb bud mesenchyme results in transient metaphyseal dysplasia derived from impaired chondrocyte differentiation.During bone regeneration,Apex1 silencing induces a fracture nonunion phenotype,characterized by delayed fracture repair initiation,impaired periosteal response,and reduced chondrocyte and osteoblast differentiation.This compromised chondrocyte differentiation hampers callus vascularization and healing progression.Our findings highlight a critical mechanism where hypoxia-driven ROS signaling in mesenchymal progenitors through APEX1 is essential for fracture healing initiation.
基金Funded by the National Natural Science Foundation of China Guangdong(No.22279096)。
文摘Silica nanoparticles-stabilized cobalt and nitrogen-doped carbon materials were synthesized through pyrolysis of metal-organic-framework of ZIF-67 supported by silica nanoparticles.The experimental results reveal that the introduction of the silica nanoparticles can stabilize the microstructure of the derived CoN-C materials,which in turn exhibits the promising electrocatalytic activity towards both oxygen reduction and oxygen evolution reactions.The optimized sample exhibits a better oxygen reduction activity than commercial Pt/C catalyst as confirmed by the positive shift of half-wave potential by 20 mV while it has a low overpotential of 273 mV for oxygen evolution reactions with the retained performance over 80%after 25,000 s of continuous operation.It is demonstrated that the introduction of support frame might be an effective way to improve the activity and stability of metal-organic-framework derived electrocatalyst with stabilized microstructure.
