HZSM-5 zeolites with the micro-mesopore hierarchical porosity have been prepared by the post-synthesis of alkali-treatment, and their thermal and hydrothermal stabilities were studied using DTA, XRD, and NH3-TPD chara...HZSM-5 zeolites with the micro-mesopore hierarchical porosity have been prepared by the post-synthesis of alkali-treatment, and their thermal and hydrothermal stabilities were studied using DTA, XRD, and NH3-TPD characterization techniques. Compared to the unmodified zeolite, the thermal and hydrothermal stabilities of the alkali-treated ZSM-5 zeolites were slightly deteriorated because of the introduction of mesopores caused by the desilication. Nevertheless, the alkali-treated zeolite framework could be maintained until the temperature increased to 1175 ℃.展开更多
Poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this condition.The aims of this study were to...Poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this condition.The aims of this study were to(1)determine the specific relationship between hypoxic andα-synuclein during the occur of poststroke cognitive impairment and(2)assess whether the serum phosphorylatedα-synuclein level can be used as a biomarker for poststro ke cognitive impairment.We found that the phosphorylatedα-synuclein level was significantly increased and showed pathological aggregation around the cerebral infa rct area in a mouse model of ischemic stroke.In addition,neuronalα-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia,suggesting that hypoxia is the underlying cause ofα-synuclein-mediated pathology in the brains of mice with ischemic stroke.Serum phosphorylatedα-synuclein levels in patients with ischemic stroke were significantly lower than those in healt hy subjects,and were positively correlated with cognition levels in patients with ischemic stroke.Furthermore,a decrease in serum high-density lipoprotein levels in stroke patie nts was significantly correlated with a decrease in phosphorylatedα-synuclein levels.Although ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury,some of them exhibited decreased cognitive function and reduced phosphorylatedα-synuclein levels.Taken together,our results suggest that serum phosphorylatedα-synuclein is a potential biomarker for poststroke cognitive impairment.展开更多
For environmental applications,it is crucial to rationally design and synthesize photocatalysts with positive exciton splitting and interfacial charge transfer.Here,a novel Agbridged dual Z-scheme Ag/g-C_(3)N_(4)/CoNi...For environmental applications,it is crucial to rationally design and synthesize photocatalysts with positive exciton splitting and interfacial charge transfer.Here,a novel Agbridged dual Z-scheme Ag/g-C_(3)N_(4)/CoNi-LDH plasmonic heterojunction was successfully synthesized using a simple method,with the goal of overcoming the common drawbacks of traditional photocatalysts such as weak photoresponsivity,rapid combination of photogenerated carriers,and unstable structure.These materials were characterized by XRD,FT-IR,SEM,TEM UV-Vis/DRS,and XPS to verify the structure and stability of the heterostructure.The pristine LDH,g-C_(3)N_(4),and Ag/g-C_(3)N_(4)/CoNi-LDH composite were investigated as photocatalysts for water remediation,an environmentally motivated process.Specifically,the photocatalytic degradation of tetracycline was studied as a model reaction.The performance of the supports and composite catalyst were determined by evaluating both the degradation and adsorption phenomenon.The influence of several experimental parameters such as catalyst loading,pH,and tetracycline concentrationwere evaluated.The current study provides important data for water treatment and similar environmental protection applications.展开更多
Wearable thermoelectric devices hold significant promise in the realm of self-powered wearable electron-ics,offering applications in energy harvesting,movement tracking,and health monitoring.Nevertheless,developing th...Wearable thermoelectric devices hold significant promise in the realm of self-powered wearable electron-ics,offering applications in energy harvesting,movement tracking,and health monitoring.Nevertheless,developing thermoelectric devices with exceptional flexibility,enduring thermoelectric stability,multi-functional sensing,and comfortable wear remains a challenge.In this work,a stretchable MXene-based thermoelectric fabric is designed to accurately discern temperature and strain stimuli.This is achieved by constructing an adhesive polydopamine(PDA)layer on the nylon fabric surface,which facilitates the subsequent MXene attachment through hydrogen bonding.This fusion results in MXene-based thermo-electric fabric that excels in both temperature sensing and strain sensing.The resultant MXene-based thermoelectric fabric exhibits outstanding temperature detection capability and cyclic stability,while also delivering excellent sensitivity,rapid responsiveness(60 ms),and remarkable durability in strain sens-ing(3200 cycles).Moreover,when affixed to a mask,this MXene-based thermoelectric fabric utilizes the temperature difference between the body and the environment to harness body heat,converting it into electrical energy and accurately discerning the body’s respiratory rate.In addition,the MXene-based ther-moelectric fabric can monitor the state of the body’s joint through its own deformation.Furthermore,it possesses the capability to convert solar energy into heat.These findings indicate that MXene-based ther-moelectric fabric holds great promise for applications in power generation,motion tracking,and health monitoring.展开更多
Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for t...Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for the post-Moore era,offering significant potential in domains such as integrated circuits and next-generation computing.Here,in this review,the progress of 2D semiconductors in process engineering and various electronic applications are summarized.A careful introduction of material synthesis,transistor engineering focused on device configuration,dielectric engineering,contact engineering,and material integration are given first.Then 2D transistors for certain electronic applications including digital and analog circuits,heterogeneous integration chips,and sensing circuits are discussed.Moreover,several promising applications(artificial intelligence chips and quantum chips)based on specific mechanism devices are introduced.Finally,the challenges for 2D materials encountered in achieving circuit-level or system-level applications are analyzed,and potential development pathways or roadmaps are further speculated and outlooked.展开更多
Organic cathode materials present a promising alternative for the inorganic counterparts in conventional lithiumion batteries(LIBs)due to lower cost,reduced environmental impact,renewability,and enhanced energy densit...Organic cathode materials present a promising alternative for the inorganic counterparts in conventional lithiumion batteries(LIBs)due to lower cost,reduced environmental impact,renewability,and enhanced energy density.However,their practical application is hindered by dissolution in electrolytes,structural degradation,and sluggish lithium-ion transport.In this study,we introduce fluoroethylene carbonate(FEC)as an electrolyte additive to engineer a protective cathode–electrolyte interphase(CEI)layer,effectively mitigating cathode pulverization and enhancing battery stability of the organic cathode material,dilithium salt of 2,5-dihydroxy-1,4-benzoquinone(Li_(2)DHBQ).Electrochemical,morphological,and compositional analyses,including cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS),confirm that an optimal 1%FEC concentration forms a uniform CEI layer,significantly improving structural integrity and reducing interfacial resistance.Consequently,the battery with 1%FEC retains 185 mAh·g^(−1) after 200 cycles at 500 mA·g^(−1),with a capacity decay rate of just 0.049%per cycle,compared to 81 mAh·g^(−1) and 0.302%per cycle for the FEC-free battery.Additionally,the 1%FEC battery exhibits a capacitive charge storage contribution of up to 93.7%,resulting in excellent rate performance.These findings underscore the crucial role of CEI engineering in stabilizing organic cathodes,offering a practical approach to achieving high-rate and long-cycle LIBs.展开更多
Vascular cognitive impairment and dementia is a debilitating neurological disorder caused by chronic cerebral hypoperfusion,for which no effective causative treatments are currently available.Intermittent hypoxia has ...Vascular cognitive impairment and dementia is a debilitating neurological disorder caused by chronic cerebral hypoperfusion,for which no effective causative treatments are currently available.Intermittent hypoxia has been shown to enhance cerebral blood flow in mice,but its efficacy in a model of vascular cognitive impairment and dementia remains unclear.In this study,we established a mouse model of vascular cognitive impairment and dementia by bilateral carotid artery stenosis.Intermittent hypoxia was induced before and after this stenosis.We found that intermittent hypoxia increased cerebral blood flow,oxygen saturation,and microcirculation in the prefrontal cortex and hippocampus in the model mice,without causing neurovascular damage.Additionally,intermittent hypoxia significantly improved cognitive function in the mouse model of vascular cognitive impairment and dementia,with perconditioning showing greater efficacy than preconditioning.Improvements in cerebral microcirculation and blood flow were positively correlated with cognitive recovery.Even in a mouse model of vascular cognitive impairment and dementia with comorbidities induced by a high-fat,high-fructose diet,intermittent hypoxic perconditioning demonstrated protective effects on cognitive function.Proteomic analysis indicated that mitochondrial protection is a key mechanism,particularly through upregulating NDUFB8 expression and increasing the activity of mitochondrial complex I.These findings suggest that intermittent hypoxia is a potential non-invasive strategy for the prevention and treatment of vascular cognitive impairment and dementia.展开更多
基金the National Key Project for Basic Research of China(973 Project)(No.2005CB221403)the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant:DICP K2007D3)
文摘HZSM-5 zeolites with the micro-mesopore hierarchical porosity have been prepared by the post-synthesis of alkali-treatment, and their thermal and hydrothermal stabilities were studied using DTA, XRD, and NH3-TPD characterization techniques. Compared to the unmodified zeolite, the thermal and hydrothermal stabilities of the alkali-treated ZSM-5 zeolites were slightly deteriorated because of the introduction of mesopores caused by the desilication. Nevertheless, the alkali-treated zeolite framework could be maintained until the temperature increased to 1175 ℃.
基金supported by the Scientific Research Project of China Rehabilitation Research Center,No.2021zx-23the National Natural Science Foundation of China,No.32100925the Beijing Nova Program,No.Z211100002121038。
文摘Poststro ke cognitive impairment is a major secondary effect of ischemic stroke in many patients;however,few options are available for the early diagnosis and treatment of this condition.The aims of this study were to(1)determine the specific relationship between hypoxic andα-synuclein during the occur of poststroke cognitive impairment and(2)assess whether the serum phosphorylatedα-synuclein level can be used as a biomarker for poststro ke cognitive impairment.We found that the phosphorylatedα-synuclein level was significantly increased and showed pathological aggregation around the cerebral infa rct area in a mouse model of ischemic stroke.In addition,neuronalα-synuclein phosphorylation and aggregation were observed in the brain tissue of mice subjected to chronic hypoxia,suggesting that hypoxia is the underlying cause ofα-synuclein-mediated pathology in the brains of mice with ischemic stroke.Serum phosphorylatedα-synuclein levels in patients with ischemic stroke were significantly lower than those in healt hy subjects,and were positively correlated with cognition levels in patients with ischemic stroke.Furthermore,a decrease in serum high-density lipoprotein levels in stroke patie nts was significantly correlated with a decrease in phosphorylatedα-synuclein levels.Although ischemic stroke mice did not show significant cognitive impairment or disrupted lipid metabolism 14 days after injury,some of them exhibited decreased cognitive function and reduced phosphorylatedα-synuclein levels.Taken together,our results suggest that serum phosphorylatedα-synuclein is a potential biomarker for poststroke cognitive impairment.
文摘For environmental applications,it is crucial to rationally design and synthesize photocatalysts with positive exciton splitting and interfacial charge transfer.Here,a novel Agbridged dual Z-scheme Ag/g-C_(3)N_(4)/CoNi-LDH plasmonic heterojunction was successfully synthesized using a simple method,with the goal of overcoming the common drawbacks of traditional photocatalysts such as weak photoresponsivity,rapid combination of photogenerated carriers,and unstable structure.These materials were characterized by XRD,FT-IR,SEM,TEM UV-Vis/DRS,and XPS to verify the structure and stability of the heterostructure.The pristine LDH,g-C_(3)N_(4),and Ag/g-C_(3)N_(4)/CoNi-LDH composite were investigated as photocatalysts for water remediation,an environmentally motivated process.Specifically,the photocatalytic degradation of tetracycline was studied as a model reaction.The performance of the supports and composite catalyst were determined by evaluating both the degradation and adsorption phenomenon.The influence of several experimental parameters such as catalyst loading,pH,and tetracycline concentrationwere evaluated.The current study provides important data for water treatment and similar environmental protection applications.
基金supported by the National Natural Science Foundation of China(No.21975107)the China Scholarship Council(No.202206790046).
文摘Wearable thermoelectric devices hold significant promise in the realm of self-powered wearable electron-ics,offering applications in energy harvesting,movement tracking,and health monitoring.Nevertheless,developing thermoelectric devices with exceptional flexibility,enduring thermoelectric stability,multi-functional sensing,and comfortable wear remains a challenge.In this work,a stretchable MXene-based thermoelectric fabric is designed to accurately discern temperature and strain stimuli.This is achieved by constructing an adhesive polydopamine(PDA)layer on the nylon fabric surface,which facilitates the subsequent MXene attachment through hydrogen bonding.This fusion results in MXene-based thermo-electric fabric that excels in both temperature sensing and strain sensing.The resultant MXene-based thermoelectric fabric exhibits outstanding temperature detection capability and cyclic stability,while also delivering excellent sensitivity,rapid responsiveness(60 ms),and remarkable durability in strain sens-ing(3200 cycles).Moreover,when affixed to a mask,this MXene-based thermoelectric fabric utilizes the temperature difference between the body and the environment to harness body heat,converting it into electrical energy and accurately discerning the body’s respiratory rate.In addition,the MXene-based ther-moelectric fabric can monitor the state of the body’s joint through its own deformation.Furthermore,it possesses the capability to convert solar energy into heat.These findings indicate that MXene-based ther-moelectric fabric holds great promise for applications in power generation,motion tracking,and health monitoring.
基金supported in part by STI 2030-Major Projects under Grant 2022ZD0209200sponsored by Tsinghua-Toyota Joint Research Fund+12 种基金in part by National Natural Science Foundation of China under Grant 62374099, Grant 62022047, Grant U20A20168, Grant 51861145202, Grant 51821003, and Grant 62175219in part by the National Key R&D Program under Grant 2016YFA0200400in part by Beijing Natural Science-Xiaomi Innovation Joint Fund Grant L233009in part supported by Tsinghua University-Zhuhai Huafa Industrial Share Company Joint Institute for Architecture Optoelectronic Technologies (JIAOT KF202204)in part by the Daikin-Tsinghua Union Programin part sponsored by CIE-Tencent Robotics X Rhino-Bird Focused Research Programin part by the Guoqiang Institute, Tsinghua Universityin part by the Research Fund from Beijing Innovation Center for Future Chipin part by Shanxi “1331 Project” Key Subjects Constructionin part by the Youth Innovation Promotion Association of Chinese Academy of Sciences (2019120)the opening fund of Key Laboratory of Science and Technology on Silicon Devices, Chinese Academy of Sciencesin part by the project of MOE Innovation Platformin part by the State Key Laboratory of Integrated Chips and Systems
文摘Due to the constraints imposed by physical effects and performance degra certain limitations in sustaining the advancement of Moore’s law.Two-dimensional(2D)materials have emerged as highly promising candidates for the post-Moore era,offering significant potential in domains such as integrated circuits and next-generation computing.Here,in this review,the progress of 2D semiconductors in process engineering and various electronic applications are summarized.A careful introduction of material synthesis,transistor engineering focused on device configuration,dielectric engineering,contact engineering,and material integration are given first.Then 2D transistors for certain electronic applications including digital and analog circuits,heterogeneous integration chips,and sensing circuits are discussed.Moreover,several promising applications(artificial intelligence chips and quantum chips)based on specific mechanism devices are introduced.Finally,the challenges for 2D materials encountered in achieving circuit-level or system-level applications are analyzed,and potential development pathways or roadmaps are further speculated and outlooked.
基金supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)through the Discovery Grants(No.RGPIN-2022-03835)Alliance Grants(No.ALLRP 581429-23)the Mitacs Accelerate Fellowship(No.IT35432).
文摘Organic cathode materials present a promising alternative for the inorganic counterparts in conventional lithiumion batteries(LIBs)due to lower cost,reduced environmental impact,renewability,and enhanced energy density.However,their practical application is hindered by dissolution in electrolytes,structural degradation,and sluggish lithium-ion transport.In this study,we introduce fluoroethylene carbonate(FEC)as an electrolyte additive to engineer a protective cathode–electrolyte interphase(CEI)layer,effectively mitigating cathode pulverization and enhancing battery stability of the organic cathode material,dilithium salt of 2,5-dihydroxy-1,4-benzoquinone(Li_(2)DHBQ).Electrochemical,morphological,and compositional analyses,including cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS),confirm that an optimal 1%FEC concentration forms a uniform CEI layer,significantly improving structural integrity and reducing interfacial resistance.Consequently,the battery with 1%FEC retains 185 mAh·g^(−1) after 200 cycles at 500 mA·g^(−1),with a capacity decay rate of just 0.049%per cycle,compared to 81 mAh·g^(−1) and 0.302%per cycle for the FEC-free battery.Additionally,the 1%FEC battery exhibits a capacitive charge storage contribution of up to 93.7%,resulting in excellent rate performance.These findings underscore the crucial role of CEI engineering in stabilizing organic cathodes,offering a practical approach to achieving high-rate and long-cycle LIBs.
基金supported by the Beijing Nova Program,Nos.20230484436,Z211100002121038the Chinese Institutes for Medical Research,No.CX23YQ01+1 种基金the NationalNatural Science Foundation of China,Nos.32100925,82027802Beijing-Tianjin-Hebei Basic Research Cooperation Project,No.22JCZXJC00190(all to XJand JL).
文摘Vascular cognitive impairment and dementia is a debilitating neurological disorder caused by chronic cerebral hypoperfusion,for which no effective causative treatments are currently available.Intermittent hypoxia has been shown to enhance cerebral blood flow in mice,but its efficacy in a model of vascular cognitive impairment and dementia remains unclear.In this study,we established a mouse model of vascular cognitive impairment and dementia by bilateral carotid artery stenosis.Intermittent hypoxia was induced before and after this stenosis.We found that intermittent hypoxia increased cerebral blood flow,oxygen saturation,and microcirculation in the prefrontal cortex and hippocampus in the model mice,without causing neurovascular damage.Additionally,intermittent hypoxia significantly improved cognitive function in the mouse model of vascular cognitive impairment and dementia,with perconditioning showing greater efficacy than preconditioning.Improvements in cerebral microcirculation and blood flow were positively correlated with cognitive recovery.Even in a mouse model of vascular cognitive impairment and dementia with comorbidities induced by a high-fat,high-fructose diet,intermittent hypoxic perconditioning demonstrated protective effects on cognitive function.Proteomic analysis indicated that mitochondrial protection is a key mechanism,particularly through upregulating NDUFB8 expression and increasing the activity of mitochondrial complex I.These findings suggest that intermittent hypoxia is a potential non-invasive strategy for the prevention and treatment of vascular cognitive impairment and dementia.
