Investigating the damage evolution of surrounding rock under thermal shock cycles is crucial for ensuring the stability of engineering rock masses.This study performed Brazilian splitting tests on granite specimens un...Investigating the damage evolution of surrounding rock under thermal shock cycles is crucial for ensuring the stability of engineering rock masses.This study performed Brazilian splitting tests on granite specimens under varying temperature and cycle conditions,employing acoustic emission monitoring,digital image correlation,and three-dimensional scanning technology.A systematic analysis was conducted on the patterns of damage evolution,failure precursor,and response mechanisms under combined thermal and cyclic loading.Experimental results show that both P-wave velocity and tensile strength degrade significantly with increasing temperature and cycle count,with temperature having a more pronounced effect than cycle count.Notably,damage evolution exhibits a dual-threshold behavior in which degradation accelerates markedly above 400℃ and stabilizes after 5 thermal cycles.Fracture surfaces evolve from initially planar to rugged morphologies,with peak-valley height differences at 600℃ being approximately three times greater than those at 200℃.Furthermore,based on acoustic emission energy entropy analysis,we introduce a novel failure precursor indicator where the sustained increase and critical surge in average entropy serve as reliable early-warning signals for impending rock failure.These findings establish a solid theoretical basis and practical methodology for damage assessment and instability early-warning systems in high-temperature rock engineering.展开更多
Extensive engineering experience and research findings suggest that rock mass instability is typically attributed to human engineering activities and natural disturbances,resulting in general dynamic mechanical proper...Extensive engineering experience and research findings suggest that rock mass instability is typically attributed to human engineering activities and natural disturbances,resulting in general dynamic mechanical properties.This is attributed to external interference resulting from the extensive use of the mechanical and blasting techniques necessary for mineral extraction.Quantifying the impact of dynamic disturbances on rock deformation behavior is essential for comprehending the long-term response of surrounding rock during excavation.This study placed the rock to sustained pressure and investigated the impact of varying hammer heights and dry and wet(W-D)damage on its shear failure behavior.This study investigated the fatigue disturbance studies on W-D damaged sandstone samples via W-D equipment,a disturbance creep device,digital image correlation(DIC),and acoustic emission(AE)technology.The experimental findings suggest that acoustic emission sensors can be utilized to quantify the internal damage of rock samples during cyclic impact,whereas DIC technology(optical measurement)is capable of capturing the surface crack propagation of samples.Under repeated impact and the combined action of W-D conditions,the bearing capacity of sandstone decreases,whereas the deformation capacity increases.Furthermore,the W-D cycles and impact strength are inversely related to the fatigue life.The intensity of W-D damage and disturbances further accelerates the development and propagation of cracks under cyclic disturbances.The research results are of preventive significance to ensure the safety and sustainable development of engineering construction.展开更多
Temperature-dependent resistivity,upper critical field H_(c2)and its anisotropy in overdoped superconducting Ba_(1-x)K_x Fe_2As_2(x=0.6-1)single crystals have been measured in steady magnetic fields up to 44 T and low...Temperature-dependent resistivity,upper critical field H_(c2)and its anisotropy in overdoped superconducting Ba_(1-x)K_x Fe_2As_2(x=0.6-1)single crystals have been measured in steady magnetic fields up to 44 T and low temperatures down to 0.4 K.Analysis using both the quadratic term and power-law fitting demonstrates that the in-plane resistivityρ_(ab)(T)progressively approaches the Fermi-liquid T~2behavior with increasing K doping and reaches a saturation plateau at x≈0.8.The temperature dependence of both H_(c2)^(ab)and H^(c)_(c2)follows the Werthamer-Helfand-Hohenberg model,incorporating orbital and spin paramagnetic effects.For x≤0.8,the orbital effect dominates for H ab,while the Pauli paramagnetic effect prevails for H c.For x>0.8,the Pauli paramagnetic effect becomes dominant in both crystallographic directions.The anisotropy of H_(c2)(0)exhibits a discontinuity in its dependence on K doping concentration with a significant enhancement at x=0.8 and a maximum at x=0.9.These experimental results indicate that the electron correlation effect is enhanced in the heavily overdoped Ba_(1-x)K_(x)Fe_(2)As_(2)system where the underlying symmetries are broken due to the Fermi surface reconstruction before x=0.9.展开更多
The Southern Great Xing’an Range(SGXR)which forms part of the eastern segment of the Central Asian Orogenic Belt(CAOB)is known as one of the most important Cu-Mo-Pb-Zn-Ag-Au metallogenic belts in China,hosting a numb...The Southern Great Xing’an Range(SGXR)which forms part of the eastern segment of the Central Asian Orogenic Belt(CAOB)is known as one of the most important Cu-Mo-Pb-Zn-Ag-Au metallogenic belts in China,hosting a number of porphyry Mo(Cu),skarn Fe(Sn),epithermal Au-Ag,and hydrothermal veintype Ag-Pb-Zn ore deposits.Here we investigate the Bianjiadayuan hydrothermal vein-type Ag-Pb-Zn ore deposit in the southern part of the SGXR.Porphyry Sn±Cu±Mo mineralization is also developed to the west of the Ag-Pb-Zn veins in the ore field.We identify a five-stage mineralization process based on field and petrologic studies including(i)the early porphyry mineralization stage,(ii)main porphyry mineralization stage,(iii)transition mineralization stage,(iv)vein-type mineralization stage and(v)late mineralization stage.Pyrite is the predominant sulfide mineral in all stages except in the late mineralization stage,and we identify corresponding four types of pyrites:Py1 is medium-grained subhedral to euhedral occurring in the early barren quartz vein;Py2 is medium-to fine-grained euhedral pyrite mainly coexisting with molybdenite,chalcopyrite,minor sphalerite and galena;Py3 is fine-grained,subhedral to irregular pyrite and displays cataclastic textures with micro-fractures;Py4 occurs as euhedral microcrystals and forms irregularly shaped aggregate with sphalerite and galena.LA-ICP-MS trace element analyses of pyrite show that Cu,Pb,Zn,Ag,Sn,Cd and Sb are partitioned into pyrite as structurally bound metals or mineral micro/nano-inclusions,whereas Co,Ni,As and Se enter the lattice via isomorphism in all types of pyrite.The Cu,Zn,Ag,Cd concentrations gradually increase from Py1 to Py4,which we correlate with cooling and mixing of ore-forming fluid with meteoric water.Py2 contains the highest contents of Co,Ni,Se,Te and Bi,suggesting high temperature conditions for the porphyry mineralization stage.Ratios of Co/Ni(0.03-10.79,average 2.13)and sulphur isotope composition of sulfide indicate typical hydrothermal origin for pyrites.Theδ^34SCDT values of Py1(0.42‰-1.61‰,average 1.16‰),Py2(-1.23‰to 0.82‰,average 0.35‰),Py3(-0.36‰to 2.47‰,average 0.97‰),Py4(2.51‰-3.72‰,average 3.06‰),and other sulfides are consistent with those of typical porphyry deposit(-5‰to 5‰),indicating that the Pb-Zn polymetallic mineralization in the Bianjiadayuan deposit is genetically linked to the Yanshanian(JurassiceCretaceous)magmatic-hydrothermal events.Variations of d34S values are ascribed to the changes in physical and chemical conditions during the evolution and migration of the ore-forming fluid.We propose that the high Sn content of pyrite in the Bianjiadayuan hydrothermal vein-type PbeZn polymetallic deposit can be used as a possible pathfinder to prospect for Sn mineralization in the surrounding area or deeper level of the ore field in this region.展开更多
对科学基金各学科的发展态势进行分析,可以为诊断学科发展现状、制定学科发展战略规划提供参考依据。本研究从科研产出视角出发,以2013—2022年的Web of Science(WoS)论文为数据源,应用科学计量学方法,从学科结构、产出成效、国际合作...对科学基金各学科的发展态势进行分析,可以为诊断学科发展现状、制定学科发展战略规划提供参考依据。本研究从科研产出视角出发,以2013—2022年的Web of Science(WoS)论文为数据源,应用科学计量学方法,从学科结构、产出成效、国际合作三个维度,对科学基金各学科的发展态势进行横向对比分析。研究发现,在学科结构方面,中国在物质科学及工程技术类优势学科规模指标表现突出,效率指标差距显著,需着重鼓励优势学科原创性、引领性研究产出,实现突破式创新发展。中国的学科结构均衡性不断加强,在学科均衡协同发展的基础上,需优先支持国家战略需求领域和科学前沿领域突破。在资助成效方面,国家自然科学基金项目的资助具有较高投入产出效率,且有效推动了重要成果的产出,需继续加强高产出效率领域及重要成果团队的后续资助力度,进一步提升投入产出效率。在国际合作方面,中国天文学、管理科学国际合作论文份额最高,化学、医学份额最低,各学科的国际合作论文份额自2020年起均呈显著下降趋势,其中中美合作大幅下滑,材料科学和力学领域下降最为明显。需聚焦全球关注的热点科研问题,构建更加多元化的国际科研合作网络。展开更多
This paper proposes a Reinforcement learning(RL)algorithm to find an optimal scheduling policy to minimize the delay for a given energy constraint in communication system where the environments such as traffic arrival...This paper proposes a Reinforcement learning(RL)algorithm to find an optimal scheduling policy to minimize the delay for a given energy constraint in communication system where the environments such as traffic arrival rates are not known in advance and can change over time.For this purpose,this problem is formulated as an infinite-horizon Constrained Markov Decision Process(CMDP).To handle the constrained optimization problem,we first adopt the Lagrangian relaxation technique to solve it.Then,we propose a variant of Q-learning,Q-greedyUCB that combinesε-greedy and Upper Confidence Bound(UCB)algorithms to solve this constrained MDP problem.We mathematically prove that the Q-greedyUCB algorithm converges to an optimal solution.Simulation results also show that Q-greedyUCB finds an optimal scheduling strategy,and is more efficient than Q-learning withε-greedy,R-learning and the Averagepayoff RL(ARL)algorithm in terms of the cumulative regret.We also show that our algorithm can learn and adapt to the changes of the environment,so as to obtain an optimal scheduling strategy under a given power constraint for the new environment.展开更多
Taking Ludian County in Zhaotong City of Yunnan Province for example,according to the data on residents'income gap in Ludian County during the period 2002-2011,we analyze the residents'income gap in Ludian Cou...Taking Ludian County in Zhaotong City of Yunnan Province for example,according to the data on residents'income gap in Ludian County during the period 2002-2011,we analyze the residents'income gap in Ludian County,and offer the forecast value of residents'income gap in Ludian County during the period 2012-2015,using Compertz curve model and Eviews software for fitting.The forecast value shows that the residents'income gap will continue to widen in Ludian County.Finally we put forth the recommendations for bridging the residents'income gap in Ludian County,in order to provide a reference for settling the problems concerning residents'income gap in other state-level povertystricken counties of Yunnan Province.展开更多
Objective This study aimed to investigate the neuroprotective effects of cholecalciferol cholesterol emulsion(CCE),a vitamin D(VD)precursor,in a murine model of acute cerebral infarction(ACI)and to elucidate the role ...Objective This study aimed to investigate the neuroprotective effects of cholecalciferol cholesterol emulsion(CCE),a vitamin D(VD)precursor,in a murine model of acute cerebral infarction(ACI)and to elucidate the role of the Nrf2 signaling pathway in mediating these effects.Methods Forty C57BL/6J mice(male and female)were divided into five groups(n=10 per group):control,control+CCE,ACI,ACI+CCE,and ACI+CCE+ML385(an Nrf2 inhibitor).ACI was induced by middle cerebral artery occlusion(MCAO).CCE was administered for three weeks prior to ACI induction,and ML385 was administered intravenously to inhibit Nrf2.Neurological function,brain edema,and infarct size,as well as inflammatory and apoptotic marker levels,were assessed post-ACI.Statistical analyses were conducted via one-way ANOVA and Student's t test,with P<0.05 considered significant.Results Compared to ACI group,CCE significantly reduced neurological deficits,brain edema,and infarct size(P<0.01).The ACI+CCE group presented improved short-term memory retention,as evidenced by shorter avoidance latency in shuttle avoidance tests(P<0.01).CCE administration attenuated the expression of inflammatory markers(IL-6,MIF,Lp-PLA2)while increasing IL-10 levels(P<0.001).Furthermore,CCE increased Nrf2 and HO-1 expression and reduced apoptosis by decreasing the Bax/Bcl-2 ratio in brain tissue(P<0.001).ML385 abolished these neuroprotective effects,confirming the role of the Nrf2 pathway in mediating the benefits of VD.Conclusion VD,via VD receptor-mediated activation of the Nrf2/HO-1 pathway,reduces inflammation,apoptosis,and neurological damage following ACI.These findings support the therapeutic potential of VD in the treatment of ischemic stroke and highlight the importance of Nrf2 in mediating these effects.展开更多
基金supported by National Natural Science Foundation of China (Nos.52264006,52364004,and 52464005)the Guizhou Provincial Science and Technology Foundation (No.GCC[2022]005-1)。
文摘Investigating the damage evolution of surrounding rock under thermal shock cycles is crucial for ensuring the stability of engineering rock masses.This study performed Brazilian splitting tests on granite specimens under varying temperature and cycle conditions,employing acoustic emission monitoring,digital image correlation,and three-dimensional scanning technology.A systematic analysis was conducted on the patterns of damage evolution,failure precursor,and response mechanisms under combined thermal and cyclic loading.Experimental results show that both P-wave velocity and tensile strength degrade significantly with increasing temperature and cycle count,with temperature having a more pronounced effect than cycle count.Notably,damage evolution exhibits a dual-threshold behavior in which degradation accelerates markedly above 400℃ and stabilizes after 5 thermal cycles.Fracture surfaces evolve from initially planar to rugged morphologies,with peak-valley height differences at 600℃ being approximately three times greater than those at 200℃.Furthermore,based on acoustic emission energy entropy analysis,we introduce a novel failure precursor indicator where the sustained increase and critical surge in average entropy serve as reliable early-warning signals for impending rock failure.These findings establish a solid theoretical basis and practical methodology for damage assessment and instability early-warning systems in high-temperature rock engineering.
基金supported by National Natural Science Foundation of China(Grant Nos.52364004 and 52264006)The Youth Talent Growth Project of Guizhou Provincial Department of Education(Grant No.QianJiaoJi[2024]18).
文摘Extensive engineering experience and research findings suggest that rock mass instability is typically attributed to human engineering activities and natural disturbances,resulting in general dynamic mechanical properties.This is attributed to external interference resulting from the extensive use of the mechanical and blasting techniques necessary for mineral extraction.Quantifying the impact of dynamic disturbances on rock deformation behavior is essential for comprehending the long-term response of surrounding rock during excavation.This study placed the rock to sustained pressure and investigated the impact of varying hammer heights and dry and wet(W-D)damage on its shear failure behavior.This study investigated the fatigue disturbance studies on W-D damaged sandstone samples via W-D equipment,a disturbance creep device,digital image correlation(DIC),and acoustic emission(AE)technology.The experimental findings suggest that acoustic emission sensors can be utilized to quantify the internal damage of rock samples during cyclic impact,whereas DIC technology(optical measurement)is capable of capturing the surface crack propagation of samples.Under repeated impact and the combined action of W-D conditions,the bearing capacity of sandstone decreases,whereas the deformation capacity increases.Furthermore,the W-D cycles and impact strength are inversely related to the fatigue life.The intensity of W-D damage and disturbances further accelerates the development and propagation of cracks under cyclic disturbances.The research results are of preventive significance to ensure the safety and sustainable development of engineering construction.
基金supported by the National Key Research and Development Program of China(Grant Nos.2024YFA1611100,2023YFA1406100,and 2018YFA0704201)the Systematic Fundamental Research Program Leveraging Major Scientific and Technological Infrastructure,Chinese Academy of Sciences(Grant No.JZHKYPT-2021-08)+1 种基金the National Natural Science Foundation of China(Grant Nos.11704385,11874359,and 12274444)the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB25000000)。
文摘Temperature-dependent resistivity,upper critical field H_(c2)and its anisotropy in overdoped superconducting Ba_(1-x)K_x Fe_2As_2(x=0.6-1)single crystals have been measured in steady magnetic fields up to 44 T and low temperatures down to 0.4 K.Analysis using both the quadratic term and power-law fitting demonstrates that the in-plane resistivityρ_(ab)(T)progressively approaches the Fermi-liquid T~2behavior with increasing K doping and reaches a saturation plateau at x≈0.8.The temperature dependence of both H_(c2)^(ab)and H^(c)_(c2)follows the Werthamer-Helfand-Hohenberg model,incorporating orbital and spin paramagnetic effects.For x≤0.8,the orbital effect dominates for H ab,while the Pauli paramagnetic effect prevails for H c.For x>0.8,the Pauli paramagnetic effect becomes dominant in both crystallographic directions.The anisotropy of H_(c2)(0)exhibits a discontinuity in its dependence on K doping concentration with a significant enhancement at x=0.8 and a maximum at x=0.9.These experimental results indicate that the electron correlation effect is enhanced in the heavily overdoped Ba_(1-x)K_(x)Fe_(2)As_(2)system where the underlying symmetries are broken due to the Fermi surface reconstruction before x=0.9.
基金financially supported by National Key Research and Development Program of China(2016YFC0600504)Fundamental Research Funds for the Central Universities(2652017218)
文摘The Southern Great Xing’an Range(SGXR)which forms part of the eastern segment of the Central Asian Orogenic Belt(CAOB)is known as one of the most important Cu-Mo-Pb-Zn-Ag-Au metallogenic belts in China,hosting a number of porphyry Mo(Cu),skarn Fe(Sn),epithermal Au-Ag,and hydrothermal veintype Ag-Pb-Zn ore deposits.Here we investigate the Bianjiadayuan hydrothermal vein-type Ag-Pb-Zn ore deposit in the southern part of the SGXR.Porphyry Sn±Cu±Mo mineralization is also developed to the west of the Ag-Pb-Zn veins in the ore field.We identify a five-stage mineralization process based on field and petrologic studies including(i)the early porphyry mineralization stage,(ii)main porphyry mineralization stage,(iii)transition mineralization stage,(iv)vein-type mineralization stage and(v)late mineralization stage.Pyrite is the predominant sulfide mineral in all stages except in the late mineralization stage,and we identify corresponding four types of pyrites:Py1 is medium-grained subhedral to euhedral occurring in the early barren quartz vein;Py2 is medium-to fine-grained euhedral pyrite mainly coexisting with molybdenite,chalcopyrite,minor sphalerite and galena;Py3 is fine-grained,subhedral to irregular pyrite and displays cataclastic textures with micro-fractures;Py4 occurs as euhedral microcrystals and forms irregularly shaped aggregate with sphalerite and galena.LA-ICP-MS trace element analyses of pyrite show that Cu,Pb,Zn,Ag,Sn,Cd and Sb are partitioned into pyrite as structurally bound metals or mineral micro/nano-inclusions,whereas Co,Ni,As and Se enter the lattice via isomorphism in all types of pyrite.The Cu,Zn,Ag,Cd concentrations gradually increase from Py1 to Py4,which we correlate with cooling and mixing of ore-forming fluid with meteoric water.Py2 contains the highest contents of Co,Ni,Se,Te and Bi,suggesting high temperature conditions for the porphyry mineralization stage.Ratios of Co/Ni(0.03-10.79,average 2.13)and sulphur isotope composition of sulfide indicate typical hydrothermal origin for pyrites.Theδ^34SCDT values of Py1(0.42‰-1.61‰,average 1.16‰),Py2(-1.23‰to 0.82‰,average 0.35‰),Py3(-0.36‰to 2.47‰,average 0.97‰),Py4(2.51‰-3.72‰,average 3.06‰),and other sulfides are consistent with those of typical porphyry deposit(-5‰to 5‰),indicating that the Pb-Zn polymetallic mineralization in the Bianjiadayuan deposit is genetically linked to the Yanshanian(JurassiceCretaceous)magmatic-hydrothermal events.Variations of d34S values are ascribed to the changes in physical and chemical conditions during the evolution and migration of the ore-forming fluid.We propose that the high Sn content of pyrite in the Bianjiadayuan hydrothermal vein-type PbeZn polymetallic deposit can be used as a possible pathfinder to prospect for Sn mineralization in the surrounding area or deeper level of the ore field in this region.
文摘对科学基金各学科的发展态势进行分析,可以为诊断学科发展现状、制定学科发展战略规划提供参考依据。本研究从科研产出视角出发,以2013—2022年的Web of Science(WoS)论文为数据源,应用科学计量学方法,从学科结构、产出成效、国际合作三个维度,对科学基金各学科的发展态势进行横向对比分析。研究发现,在学科结构方面,中国在物质科学及工程技术类优势学科规模指标表现突出,效率指标差距显著,需着重鼓励优势学科原创性、引领性研究产出,实现突破式创新发展。中国的学科结构均衡性不断加强,在学科均衡协同发展的基础上,需优先支持国家战略需求领域和科学前沿领域突破。在资助成效方面,国家自然科学基金项目的资助具有较高投入产出效率,且有效推动了重要成果的产出,需继续加强高产出效率领域及重要成果团队的后续资助力度,进一步提升投入产出效率。在国际合作方面,中国天文学、管理科学国际合作论文份额最高,化学、医学份额最低,各学科的国际合作论文份额自2020年起均呈显著下降趋势,其中中美合作大幅下滑,材料科学和力学领域下降最为明显。需聚焦全球关注的热点科研问题,构建更加多元化的国际科研合作网络。
基金This work was supported by the research fund of Hanyang University(HY-2019-N)This work was supported by the National Key Research&Development Program 2018YFA0701601.
文摘This paper proposes a Reinforcement learning(RL)algorithm to find an optimal scheduling policy to minimize the delay for a given energy constraint in communication system where the environments such as traffic arrival rates are not known in advance and can change over time.For this purpose,this problem is formulated as an infinite-horizon Constrained Markov Decision Process(CMDP).To handle the constrained optimization problem,we first adopt the Lagrangian relaxation technique to solve it.Then,we propose a variant of Q-learning,Q-greedyUCB that combinesε-greedy and Upper Confidence Bound(UCB)algorithms to solve this constrained MDP problem.We mathematically prove that the Q-greedyUCB algorithm converges to an optimal solution.Simulation results also show that Q-greedyUCB finds an optimal scheduling strategy,and is more efficient than Q-learning withε-greedy,R-learning and the Averagepayoff RL(ARL)algorithm in terms of the cumulative regret.We also show that our algorithm can learn and adapt to the changes of the environment,so as to obtain an optimal scheduling strategy under a given power constraint for the new environment.
文摘Taking Ludian County in Zhaotong City of Yunnan Province for example,according to the data on residents'income gap in Ludian County during the period 2002-2011,we analyze the residents'income gap in Ludian County,and offer the forecast value of residents'income gap in Ludian County during the period 2012-2015,using Compertz curve model and Eviews software for fitting.The forecast value shows that the residents'income gap will continue to widen in Ludian County.Finally we put forth the recommendations for bridging the residents'income gap in Ludian County,in order to provide a reference for settling the problems concerning residents'income gap in other state-level povertystricken counties of Yunnan Province.
基金supported by the Medical Science Research Project Program of Hebei Province(20211722).
文摘Objective This study aimed to investigate the neuroprotective effects of cholecalciferol cholesterol emulsion(CCE),a vitamin D(VD)precursor,in a murine model of acute cerebral infarction(ACI)and to elucidate the role of the Nrf2 signaling pathway in mediating these effects.Methods Forty C57BL/6J mice(male and female)were divided into five groups(n=10 per group):control,control+CCE,ACI,ACI+CCE,and ACI+CCE+ML385(an Nrf2 inhibitor).ACI was induced by middle cerebral artery occlusion(MCAO).CCE was administered for three weeks prior to ACI induction,and ML385 was administered intravenously to inhibit Nrf2.Neurological function,brain edema,and infarct size,as well as inflammatory and apoptotic marker levels,were assessed post-ACI.Statistical analyses were conducted via one-way ANOVA and Student's t test,with P<0.05 considered significant.Results Compared to ACI group,CCE significantly reduced neurological deficits,brain edema,and infarct size(P<0.01).The ACI+CCE group presented improved short-term memory retention,as evidenced by shorter avoidance latency in shuttle avoidance tests(P<0.01).CCE administration attenuated the expression of inflammatory markers(IL-6,MIF,Lp-PLA2)while increasing IL-10 levels(P<0.001).Furthermore,CCE increased Nrf2 and HO-1 expression and reduced apoptosis by decreasing the Bax/Bcl-2 ratio in brain tissue(P<0.001).ML385 abolished these neuroprotective effects,confirming the role of the Nrf2 pathway in mediating the benefits of VD.Conclusion VD,via VD receptor-mediated activation of the Nrf2/HO-1 pathway,reduces inflammation,apoptosis,and neurological damage following ACI.These findings support the therapeutic potential of VD in the treatment of ischemic stroke and highlight the importance of Nrf2 in mediating these effects.
