Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cr...Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cross-sections of Sm^(3+)result in low luminous efficiency,posing challenges for achieving high-quality solid-state lighting.Here,the excellent white emission of Sm^(3+)doped lithium aluminum silicate(LAS)glass was realized by introducing the Ag aggregates through Ag ion exchange.Under 395 nm excitation,the Ag-doped samples exhibit significant fluo⁃rescence enhancement with color coordinates close to the equal energy white point E(0.33,0.33)and a color ren⁃dering index(CRI)of 81.8.The study reveals that the surface plasmon resonance(SPR)effect of Ag nanoparticles enhances the luminescence of Sm^(3+),while the energy transfer mechanism between Ag^(+)and Sm^(3+)also promotes fluores⁃cence enhancement.By adjusting the concentration of AgNO_(3) and the exchange time,a series of high-quality full-spectrum white light emissions were obtained,indicating that the Ag ion-exchanged Sm^(3+)-doped LAS glass has good application potential in the development of solid-state lighting devices.Moreover,variations in the excitation wave⁃length can effectively tune the emission color,further demonstrating the tunability and practicality of this material in optoelectronic applications.展开更多
The zinc indium sulfide(ZnIn_(2)S_(4))semiconductors have garnered significant interest in photocatalysis due to their environmentally friendly characteristics,appropriate bandgap,and high absorption coefficient.Howev...The zinc indium sulfide(ZnIn_(2)S_(4))semiconductors have garnered significant interest in photocatalysis due to their environmentally friendly characteristics,appropriate bandgap,and high absorption coefficient.However,the exploration of advanced strategies to realize the effective and tailored doping still poses significant challenges in enhancing hydrogen evolution performance.In this work,a mild cation exchange strategy is reported to incorporate Ag cations into flower-like ZnIn_(2)S_(4) microspheres,enabling the selective replacement of Zn atoms by Ag.Remarkably,the as-fabricated Ag-ZnIn_(2)S_(4) exhibited exceptional photocatalytic hydrogen production performance,achieving a rate of 8098μmol·g^(−1)·h^(−1) under visible light irradiation.This is 4 times than that of pristine ZnIn_(2)S_(4)(2002μmol·g^(−1)·h^(−1)),and stands as the highest one among metal-doped-ZnIn_(2)S_(4) photocatalysts ever reported.Along with the theoretical calculations,it has been confirmed that the enhanced photocatalytic hydrogen generation behavior can primarily be attributed to the synergistic effect with improved light absorption,reduced adsorption energy,increased active sites and optimized charge carrier transfer,induced by the cation exchange with Ag in ZnIn_(2)S_(4).This work might provide some valuable insights on the design and development of highly efficient visible light driven photocatalysts for water splitting applications.展开更多
Aging,mitochondria,and neurodegenerative diseases:Aging is often viewed as the buildup of changes that lead to the gradual transformations associated with getting older,along with a rising likelihood of disease and mo...Aging,mitochondria,and neurodegenerative diseases:Aging is often viewed as the buildup of changes that lead to the gradual transformations associated with getting older,along with a rising likelihood of disease and mortality.Although organis m-wide deterioration is observed during aging,organs with high metabolic demand,such as the brain,are more vulnerable.展开更多
SKI family transcriptional corepressor 1(SKOR1also known as LbxCor1, Fussel15, or CORL1), is a member of the SKI family of proteins and is transcribed from a protein-coding gene located on chromosome 15 in humans, tha...SKI family transcriptional corepressor 1(SKOR1also known as LbxCor1, Fussel15, or CORL1), is a member of the SKI family of proteins and is transcribed from a protein-coding gene located on chromosome 15 in humans, that has a molecular weight of approximately 100 kDa. Skor1 is highly expressed in neurons in the central nervous system of both humans and rodents.展开更多
Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic struct...Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic structure light pressure electric generator(Basic-LPEG),which utilized a layered configuration of Ag/Pb(Zr,Ti)O_(3)(PZT)/Pt/GaAs to generate electricity based on light-induced pressure on the PZT.In this study,we sought to enhance the performance of this Basic-LPEG by introducing Ag nanoparticles/graphene oxide(AgNPs/GO)composite units(NP-LPEG),creating upgraded harvesting device.Specifically,by depositing the AgNPs/GO units twice onto the Basic-LPEG,we observed an increase in output voltage and current from 241 mV and 3.1μA to 310 mV and 9.3μA,respectively,under a solar simulator.The increase in electrical output directly correlated with the intensity of the light pressure impacting the PZT,as well as matched the Raman measurements,finite-difference time-domain simulations,and COMSOL Multiphysics Simulation.Experimental data revealed that the enhancement in electrical output was proportional to the number of hot spots generated between Ag nanoparticles,where the electric field experienced substantial amplification.These results underline the effectiveness of AgNPs/GO units in boosting the light-induced electric generation capacity,thereby providing a promising pathway for high-efficiency energy harvesting devices.展开更多
Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pa...Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pathological factor contributing to the progression of sarcopenia.However,the morphological and functional changes in mitochondria and their interplay in the degeneration of the neuromuscular junction during aging remain poorly understood.A defined systematic search of the Pub Med,Web of Science and Embase databases(last accessed on October 30,2024)was conducted with search terms including'mitochondria','aging'and'NMJ'.Clinical and preclinical studies of mitochondrial dysfunction and neuromuscular junction degeneration during aging.Twentyseven studies were included in this systematic review.This systematic review provides a summary of morphological,functional and biological changes in neuromuscular junction,mitochondrial morphology,biosynthesis,respiratory chain function,and mitophagy during aging.We focus on the interactions and mechanisms underlying the relationship between mitochondria and neuromuscular junctions during aging.Aging is characterized by significant reductions in mitochondrial fusion/fission cycles,biosynthesis,and mitochondrial quality control,which may lead to neuromuscular junction dysfunction,denervation and poor physical performance.Motor nerve terminals that exhibit redox sensitivity are among the first to exhibit abnormalities,ultimately leading to an early decline in muscle strength through impaired neuromuscular junction transmission function.Parg coactivator 1 alpha is a crucial molecule that regulates mitochondrial biogenesis and modulates various pathways,including the mitochondrial respiratory chain,energy deficiency,oxidative stress,and inflammation.Mitochondrial dysfunction is correlated with neuromuscular junction denervation and acetylcholine receptor fragmentation,resulting in muscle atrophy and a decrease in strength during aging.Physical therapy,pharmacotherapy,and gene therapy can alleviate the structural degeneration and functional deterioration of neuromuscular junction by restoring mitochondrial function.Therefore,mitochondria are considered potential targets for preserving neuromuscular junction morphology and function during aging to treat sarcopenia.展开更多
Regenerative medicine is a promising therapeutic avenue for previously incurable diseases.As the risk of chronic and degenerative diseases significantly increases with age,the elderly population represents a major coh...Regenerative medicine is a promising therapeutic avenue for previously incurable diseases.As the risk of chronic and degenerative diseases significantly increases with age,the elderly population represents a major cohort for stem cell-based therapies.However,the regenerative potential of stem cells significantly decreases with advanced age and deteriorating health status of the donor.Therefore,the efficacy of autologous stem cell therapy is significantly compromised in older patients.To overcome these limitations,alternative strategies have been used to restore the age-and disease-depleted function of stem cells.These methods aim to restore the therapeutic efficacy of aged stem cells for autologous use.This article explores the effect of donor age and health status on the regenerative potential of stem cells.It further highlights the limitations of stem cell-based therapy for autologous treatment in the elderly.A comprehensive insight into the potential strategies to address the“age”and“disease”compromised regenerative potential of autologous stem cells is also presented.The information provided here serves as a valuable resource for physicians and patients for optimization of stem cellbased autologous therapy for aged patients.展开更多
The effects of artificial aging(T6)on the creep resistance with tensile stresses in the range of 50−80 MPa at 175℃were investigated for an extruded Mg−1.22Al−0.31Ca−0.44Mn(wt.%)alloy.The Guinier-Preston(G.P.)zones pr...The effects of artificial aging(T6)on the creep resistance with tensile stresses in the range of 50−80 MPa at 175℃were investigated for an extruded Mg−1.22Al−0.31Ca−0.44Mn(wt.%)alloy.The Guinier-Preston(G.P.)zones primarily precipitate in the sample aged at 200℃for 1 h(T6-200℃/1h),while the Al_(2)Ca phases mainly precipitate in the sample aged at 275℃for 8 h(T6-275℃/8h).The T6-200℃/1h sample exhibits excellent creep resistance,with a steady-state creep rate one order of magnitude lower than that of the T6-275℃/8h sample.The abnormally high stress exponent(~8.2)observed in the T6-200℃/1h sample is associated with the power-law breakdown mechanism.TEM analysis illuminates that the creep mechanism for the T6-200℃/1h sample is cross-slip between basal and prismatic dislocations,while the T6-275℃/8h sample exhibits a mixed mechanism of dislocation cross-slip and climb.Compared with the Al_(2)Ca phase,the dense G.P.zones effectively impede dislocation climb and glide during the creep process,demonstrating superior creep resistance of the T6-200℃/1h sample.展开更多
Aging is considered the main risk factor for the development of several diseases,including the leading neurodegenerative disorders.While the cellular features of aging are complex and multifaceted,neuronal senescence ...Aging is considered the main risk factor for the development of several diseases,including the leading neurodegenerative disorders.While the cellular features of aging are complex and multifaceted,neuronal senescence has emerged as a major contributor and driver of this process in the mammalian cell.Cellular senescence is a programmed response to stress and irreparable damage,which drives the cell into an apoptosis-resistant,non-proliferative state.Senescent cells can also deleteriously affect neighboring,non-senescent cells.Senescence is a complex and multifaceted process associated with a wide range of cellular events,including the secretion of pro-inflammatory molecules and the arrest of the cell cycle.展开更多
Myelination,the continuous ensheathment of neuronal axons,is a lifelong process in the nervous system that is essential for the precise,temporospatial conduction of action potentials between neurons.Myelin also provid...Myelination,the continuous ensheathment of neuronal axons,is a lifelong process in the nervous system that is essential for the precise,temporospatial conduction of action potentials between neurons.Myelin also provides intercellular metabolic support to axons.Even minor disruptions in the integrity of myelin can impair neural performance and increase susceptibility to neurological diseases.In fact,myelin degeneration is a well-known neuropathological condition that is associated with normal aging and several neurodegenerative diseases,including multiple sclerosis and Alzheimer’s disease.In the central nervous system,compact myelin sheaths are formed by fully mature oligodendrocytes.However,the entire oligodendrocyte lineage is susceptible to changes in the biological microenvironment and other risk factors that arise as the brain ages.In addition to their well-known role in action potential propagation,oligodendrocytes also provide intercellular metabolic support to axons by transferring energy metabolites and delivering exosomes.Therefore,myelin degeneration in the aging central nervous system is a significant contributor to the development of neurodegenerative diseases.Interventions that mitigate age-related myelin degeneration can improve neurological function in aging individuals.In this review,we investigate the changes in myelin that are associated with aging and their underlying mechanisms.We also discuss recent advances in understanding how myelin degeneration in the aging brain contributes to neurodegenerative diseases and explore the factors that can prevent,slow down,or even reverse age-related myelin degeneration.Future research will enhance our understanding of how reducing age-related myelin degeneration can be used as a therapeutic target for delaying or preventing neurodegenerative diseases.展开更多
The aging process is an inexorable fact throughout our lives and is considered a major factor in develo ping neurological dysfunctions associated with cognitive,emotional,and motor impairments.Aging-associated neurode...The aging process is an inexorable fact throughout our lives and is considered a major factor in develo ping neurological dysfunctions associated with cognitive,emotional,and motor impairments.Aging-associated neurodegenerative diseases are characterized by the progressive loss of neuronal structure and function.展开更多
In order to improve the photocatalytic performance of mesoporous titania under visible light, a series of photocatalysts of S and Ag co-doped mesoporous titania have been successfully prepared by template method using...In order to improve the photocatalytic performance of mesoporous titania under visible light, a series of photocatalysts of S and Ag co-doped mesoporous titania have been successfully prepared by template method using thiourea, AgNO3 and tetrabutyl titanate as precursors and Pluronic P123 （EO20PO70EO20） as template. Scanning electron microscopy （SEM）, X-ray diffraction （XRD）, nitrogen adsorption-desorption measurements, and UV-visible spectroscopy （UV-Vis） were employed to characterize the morphology, crystal structure, surface structure, and optical absorption properties of the samples. The microcrystal of the photocatalysts consisted of anatase phase and was approximately present in the form of spherical particle. The photocatalytic performance was studied by photodegradation methyl orange （MO） in water under UV and visible light irradiation. The calcination temperature and the doping content influenced the photoactivity. In addition, the possibility of cyclic usage of co-doped mesoporous titania was also confirmed, the photocatalytic activity of mesoporous titania remained above 89% of that of the fresh sample after being used four times. It was shown that the co-doped mesoporous titania could be activated by visible light and could thus be potentially applied for the treatment of water contaminated by organic pollutants. The synergistic effect of sulfur and silver co-doping played an important role in improving the photocatalytic activity.展开更多
文摘Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cross-sections of Sm^(3+)result in low luminous efficiency,posing challenges for achieving high-quality solid-state lighting.Here,the excellent white emission of Sm^(3+)doped lithium aluminum silicate(LAS)glass was realized by introducing the Ag aggregates through Ag ion exchange.Under 395 nm excitation,the Ag-doped samples exhibit significant fluo⁃rescence enhancement with color coordinates close to the equal energy white point E(0.33,0.33)and a color ren⁃dering index(CRI)of 81.8.The study reveals that the surface plasmon resonance(SPR)effect of Ag nanoparticles enhances the luminescence of Sm^(3+),while the energy transfer mechanism between Ag^(+)and Sm^(3+)also promotes fluores⁃cence enhancement.By adjusting the concentration of AgNO_(3) and the exchange time,a series of high-quality full-spectrum white light emissions were obtained,indicating that the Ag ion-exchanged Sm^(3+)-doped LAS glass has good application potential in the development of solid-state lighting devices.Moreover,variations in the excitation wave⁃length can effectively tune the emission color,further demonstrating the tunability and practicality of this material in optoelectronic applications.
基金supported by the National Natural Science Foundation of China(Nos.52272085 and 52372063)Zhejiang Provincial Natural Science Foundation of China(No.LY23E020002)+1 种基金Ningbo Youth Science and Technology Innovation Leading Talents Project(No.2023QL031)the Postdoctoral Fellowship Program of CPSF(No.GZC20233006).
文摘The zinc indium sulfide(ZnIn_(2)S_(4))semiconductors have garnered significant interest in photocatalysis due to their environmentally friendly characteristics,appropriate bandgap,and high absorption coefficient.However,the exploration of advanced strategies to realize the effective and tailored doping still poses significant challenges in enhancing hydrogen evolution performance.In this work,a mild cation exchange strategy is reported to incorporate Ag cations into flower-like ZnIn_(2)S_(4) microspheres,enabling the selective replacement of Zn atoms by Ag.Remarkably,the as-fabricated Ag-ZnIn_(2)S_(4) exhibited exceptional photocatalytic hydrogen production performance,achieving a rate of 8098μmol·g^(−1)·h^(−1) under visible light irradiation.This is 4 times than that of pristine ZnIn_(2)S_(4)(2002μmol·g^(−1)·h^(−1)),and stands as the highest one among metal-doped-ZnIn_(2)S_(4) photocatalysts ever reported.Along with the theoretical calculations,it has been confirmed that the enhanced photocatalytic hydrogen generation behavior can primarily be attributed to the synergistic effect with improved light absorption,reduced adsorption energy,increased active sites and optimized charge carrier transfer,induced by the cation exchange with Ag in ZnIn_(2)S_(4).This work might provide some valuable insights on the design and development of highly efficient visible light driven photocatalysts for water splitting applications.
文摘Aging,mitochondria,and neurodegenerative diseases:Aging is often viewed as the buildup of changes that lead to the gradual transformations associated with getting older,along with a rising likelihood of disease and mortality.Although organis m-wide deterioration is observed during aging,organs with high metabolic demand,such as the brain,are more vulnerable.
基金supported by Science Foundation Ireland (Grant 19/FFP/6666),Cure Parkinson’s (Grant CP:GO01)a PhD studentship from the Anatomical Society。
文摘SKI family transcriptional corepressor 1(SKOR1also known as LbxCor1, Fussel15, or CORL1), is a member of the SKI family of proteins and is transcribed from a protein-coding gene located on chromosome 15 in humans, that has a molecular weight of approximately 100 kDa. Skor1 is highly expressed in neurons in the central nervous system of both humans and rodents.
基金supported by Korea Evaluation Institute of Industrial Technology(KEIT)grant funded by the Korea Government(MOTIE)(RS-2022-00154720,Technology Innovation Program Development of next-generation power semiconductor based on Si-on-SiC structure)the National Research Foundation of Korea(NRF)by the Korea government(RS-2023-NR076826)Global-Learning&Academic Research Institution for Master's·PhD students,and Postdocs(LAMP)Program of the National Research Foundation of Korea(NRF)by the Ministry of Education(No.RS-2024-00443714).
文摘Improving device efficiency is fundamental for advancing energy harvesting technology,particularly in systems designed to convert light energy into electrical output.In our previous studies,we developed a basic structure light pressure electric generator(Basic-LPEG),which utilized a layered configuration of Ag/Pb(Zr,Ti)O_(3)(PZT)/Pt/GaAs to generate electricity based on light-induced pressure on the PZT.In this study,we sought to enhance the performance of this Basic-LPEG by introducing Ag nanoparticles/graphene oxide(AgNPs/GO)composite units(NP-LPEG),creating upgraded harvesting device.Specifically,by depositing the AgNPs/GO units twice onto the Basic-LPEG,we observed an increase in output voltage and current from 241 mV and 3.1μA to 310 mV and 9.3μA,respectively,under a solar simulator.The increase in electrical output directly correlated with the intensity of the light pressure impacting the PZT,as well as matched the Raman measurements,finite-difference time-domain simulations,and COMSOL Multiphysics Simulation.Experimental data revealed that the enhancement in electrical output was proportional to the number of hot spots generated between Ag nanoparticles,where the electric field experienced substantial amplification.These results underline the effectiveness of AgNPs/GO units in boosting the light-induced electric generation capacity,thereby providing a promising pathway for high-efficiency energy harvesting devices.
基金supported by grants from Collaborative Research Fund(Ref:C4032-21GF)General Research Grant(Ref:14114822)+1 种基金Group Research Scheme(Ref:3110146)Area of Excellence(Ref:Ao E/M-402/20)。
文摘Mitochondrial dysfunction and oxidative stress are widely regarded as primary drivers of aging and are associated with several neurodegenerative diseases.The degeneration of motor neurons during aging is a critical pathological factor contributing to the progression of sarcopenia.However,the morphological and functional changes in mitochondria and their interplay in the degeneration of the neuromuscular junction during aging remain poorly understood.A defined systematic search of the Pub Med,Web of Science and Embase databases(last accessed on October 30,2024)was conducted with search terms including'mitochondria','aging'and'NMJ'.Clinical and preclinical studies of mitochondrial dysfunction and neuromuscular junction degeneration during aging.Twentyseven studies were included in this systematic review.This systematic review provides a summary of morphological,functional and biological changes in neuromuscular junction,mitochondrial morphology,biosynthesis,respiratory chain function,and mitophagy during aging.We focus on the interactions and mechanisms underlying the relationship between mitochondria and neuromuscular junctions during aging.Aging is characterized by significant reductions in mitochondrial fusion/fission cycles,biosynthesis,and mitochondrial quality control,which may lead to neuromuscular junction dysfunction,denervation and poor physical performance.Motor nerve terminals that exhibit redox sensitivity are among the first to exhibit abnormalities,ultimately leading to an early decline in muscle strength through impaired neuromuscular junction transmission function.Parg coactivator 1 alpha is a crucial molecule that regulates mitochondrial biogenesis and modulates various pathways,including the mitochondrial respiratory chain,energy deficiency,oxidative stress,and inflammation.Mitochondrial dysfunction is correlated with neuromuscular junction denervation and acetylcholine receptor fragmentation,resulting in muscle atrophy and a decrease in strength during aging.Physical therapy,pharmacotherapy,and gene therapy can alleviate the structural degeneration and functional deterioration of neuromuscular junction by restoring mitochondrial function.Therefore,mitochondria are considered potential targets for preserving neuromuscular junction morphology and function during aging to treat sarcopenia.
文摘Regenerative medicine is a promising therapeutic avenue for previously incurable diseases.As the risk of chronic and degenerative diseases significantly increases with age,the elderly population represents a major cohort for stem cell-based therapies.However,the regenerative potential of stem cells significantly decreases with advanced age and deteriorating health status of the donor.Therefore,the efficacy of autologous stem cell therapy is significantly compromised in older patients.To overcome these limitations,alternative strategies have been used to restore the age-and disease-depleted function of stem cells.These methods aim to restore the therapeutic efficacy of aged stem cells for autologous use.This article explores the effect of donor age and health status on the regenerative potential of stem cells.It further highlights the limitations of stem cell-based therapy for autologous treatment in the elderly.A comprehensive insight into the potential strategies to address the“age”and“disease”compromised regenerative potential of autologous stem cells is also presented.The information provided here serves as a valuable resource for physicians and patients for optimization of stem cellbased autologous therapy for aged patients.
基金supported by the National Natural Science Foundation of China (Nos. 52175322, 52271031)the Natural Science Foundation of Jilin Province, China (No. SKL202302015)。
文摘The effects of artificial aging(T6)on the creep resistance with tensile stresses in the range of 50−80 MPa at 175℃were investigated for an extruded Mg−1.22Al−0.31Ca−0.44Mn(wt.%)alloy.The Guinier-Preston(G.P.)zones primarily precipitate in the sample aged at 200℃for 1 h(T6-200℃/1h),while the Al_(2)Ca phases mainly precipitate in the sample aged at 275℃for 8 h(T6-275℃/8h).The T6-200℃/1h sample exhibits excellent creep resistance,with a steady-state creep rate one order of magnitude lower than that of the T6-275℃/8h sample.The abnormally high stress exponent(~8.2)observed in the T6-200℃/1h sample is associated with the power-law breakdown mechanism.TEM analysis illuminates that the creep mechanism for the T6-200℃/1h sample is cross-slip between basal and prismatic dislocations,while the T6-275℃/8h sample exhibits a mixed mechanism of dislocation cross-slip and climb.Compared with the Al_(2)Ca phase,the dense G.P.zones effectively impede dislocation climb and glide during the creep process,demonstrating superior creep resistance of the T6-200℃/1h sample.
文摘Aging is considered the main risk factor for the development of several diseases,including the leading neurodegenerative disorders.While the cellular features of aging are complex and multifaceted,neuronal senescence has emerged as a major contributor and driver of this process in the mammalian cell.Cellular senescence is a programmed response to stress and irreparable damage,which drives the cell into an apoptosis-resistant,non-proliferative state.Senescent cells can also deleteriously affect neighboring,non-senescent cells.Senescence is a complex and multifaceted process associated with a wide range of cellular events,including the secretion of pro-inflammatory molecules and the arrest of the cell cycle.
基金supported by grants from Guangdong Basic and Applied Basic Research Foundation,No.2021A1515110801(to SW)the National Natural Science Foundation of China,No.82301511(to SW)+1 种基金“Double First-Class”Construction Project of NPU,Nos.0515023GH0202320(to JC),0515023SH0201320(to JC)973 Program,No.2011CB504100(to JC).
文摘Myelination,the continuous ensheathment of neuronal axons,is a lifelong process in the nervous system that is essential for the precise,temporospatial conduction of action potentials between neurons.Myelin also provides intercellular metabolic support to axons.Even minor disruptions in the integrity of myelin can impair neural performance and increase susceptibility to neurological diseases.In fact,myelin degeneration is a well-known neuropathological condition that is associated with normal aging and several neurodegenerative diseases,including multiple sclerosis and Alzheimer’s disease.In the central nervous system,compact myelin sheaths are formed by fully mature oligodendrocytes.However,the entire oligodendrocyte lineage is susceptible to changes in the biological microenvironment and other risk factors that arise as the brain ages.In addition to their well-known role in action potential propagation,oligodendrocytes also provide intercellular metabolic support to axons by transferring energy metabolites and delivering exosomes.Therefore,myelin degeneration in the aging central nervous system is a significant contributor to the development of neurodegenerative diseases.Interventions that mitigate age-related myelin degeneration can improve neurological function in aging individuals.In this review,we investigate the changes in myelin that are associated with aging and their underlying mechanisms.We also discuss recent advances in understanding how myelin degeneration in the aging brain contributes to neurodegenerative diseases and explore the factors that can prevent,slow down,or even reverse age-related myelin degeneration.Future research will enhance our understanding of how reducing age-related myelin degeneration can be used as a therapeutic target for delaying or preventing neurodegenerative diseases.
文摘The aging process is an inexorable fact throughout our lives and is considered a major factor in develo ping neurological dysfunctions associated with cognitive,emotional,and motor impairments.Aging-associated neurodegenerative diseases are characterized by the progressive loss of neuronal structure and function.
基金This work was supported by the National Natural Sci- ence Foundation of China （No.41373127） and the Liaoning Provincial Natural Science Foundation of China （No.2013020121）.
文摘In order to improve the photocatalytic performance of mesoporous titania under visible light, a series of photocatalysts of S and Ag co-doped mesoporous titania have been successfully prepared by template method using thiourea, AgNO3 and tetrabutyl titanate as precursors and Pluronic P123 （EO20PO70EO20） as template. Scanning electron microscopy （SEM）, X-ray diffraction （XRD）, nitrogen adsorption-desorption measurements, and UV-visible spectroscopy （UV-Vis） were employed to characterize the morphology, crystal structure, surface structure, and optical absorption properties of the samples. The microcrystal of the photocatalysts consisted of anatase phase and was approximately present in the form of spherical particle. The photocatalytic performance was studied by photodegradation methyl orange （MO） in water under UV and visible light irradiation. The calcination temperature and the doping content influenced the photoactivity. In addition, the possibility of cyclic usage of co-doped mesoporous titania was also confirmed, the photocatalytic activity of mesoporous titania remained above 89% of that of the fresh sample after being used four times. It was shown that the co-doped mesoporous titania could be activated by visible light and could thus be potentially applied for the treatment of water contaminated by organic pollutants. The synergistic effect of sulfur and silver co-doping played an important role in improving the photocatalytic activity.
