To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral cortex.However,these me...To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral cortex.However,these methods often require complex systems and the effect of age on cerebral embolism has not been adequately studied,although ischemic stroke is strongly age-related.In this study,we propose an optical-resolution photoacoustic microscopy-based visualized photothrombosis methodology to create and monitor ischemic stroke in mice simultaneously using a 532 nm pulsed laser.We observed the molding process in mice of different ages and presented age-dependent vascular embolism differentiation.Moreover,we integrated optical coherence tomography angiography to investigate age-associated trends in cerebrovascular variability following a stroke.Our imaging data and quantitative analyses underscore the differential cerebrovascular responses to stroke in mice of different ages,thereby highlighting the technique's potential for evaluating cerebrovascular health and unraveling age-related mechanisms involved in ischemic strokes.展开更多
This study demonstrated that damage to the cerebral microvasculature, the formation of microthrombi and swelling of vascular endothelial cells occur early and peak 12 hours after injury in a rat model of diffuse axona...This study demonstrated that damage to the cerebral microvasculature, the formation of microthrombi and swelling of vascular endothelial cells occur early and peak 12 hours after injury in a rat model of diffuse axonal injury. Moreover, these pathological changes were most evident in the cerebral cortex. Cerebral microcirculatory dysfunction peaked later and had a shorter duration than axonal injury. In addition, the radioactive imaging agent, 99Tcm-4, 9-diaza-2, 3, 10, 10- tetramethyldodecan-2, 11 -dione dioxime, was used to visualize the dynamic changes that occur in tissue with cerebral hypoxia. The results demonstrated that cerebral hypoxia occurs at an early stage in diffuse axonal injury. Cerebral hypoxia was evident 12 hours after injury and declined slightly 24 hours after injury, but was significantly higher than in the control group. The pathological changes that underpin microcirculatory dysfunction did not occur at the same time as axonal injury, but did occur simultaneously with neuronal injury. Cerebral hypoxia plays a key role in promoting the secondary brain injury that occurs after diffuse axonal injury.展开更多
An experimental investigation into the thermal conductivity of CF-SiC two-phase composite asphalt concrete is presented.The main objective of this study was to verify the possibility of using SiC powder instead of min...An experimental investigation into the thermal conductivity of CF-SiC two-phase composite asphalt concrete is presented.The main objective of this study was to verify the possibility of using SiC powder instead of mineral powder as the thermal conductive filler to prepare a new type of asphalt concrete and improve the efficiency of electrothermal snow and ice melting systems accordingly.The thermal conductivity of asphalt concrete prepared with different thermally conductive fillers was tested by a transient plane source method,and the related performances were measured.Then the temperature rise rate and surface temperature were studied through field heating tests.Finally,the actual ice melting efficiency of the thermally conductive asphalt concrete was evaluated using an effective electrothermal system.As shown by the experimental results,the composite made of SiC powder and carbon fiber has a high thermal conductivity.When SiC replaces mineral powder,the thermal conductivity of the asphalt mixture increases first and then decreases with the increase of carbon fiber content.In the present study,in particular,the thermal conductivity attained a peak when the carbon fiber content was 0.2%of the aggregate mass.展开更多
Acute myocardial infarction(MI)remains one of the leading causes of mortality and morbidity in the global communities.A prevailing topic that has attracted increasing attentions over the past few decades is the so-cal...Acute myocardial infarction(MI)remains one of the leading causes of mortality and morbidity in the global communities.A prevailing topic that has attracted increasing attentions over the past few decades is the so-called heart-brain interaction,in particular following a major traumatic event such as MI.Increased prevalence of depression and other mental disorders has been recognized in cardiac patients after MI,coronary catheterization,or cardiothoracic surgeries.In this review,we focus on the potential pathogenic mechanisms and pre-clinical transcriptomic evidence for identifying potential mediators of post-MI depression.We first summarize the conventional mechanistic understanding that leads to the current clinical management of post-MI depression with the use of selective serotonin reuptake inhibitors(SSRIs)and cognitive behavior and exercise therapies.We further envisage a possible role played by certain chemokines,e.g.,Chemokine(C-X-C motif)ligand 12(CXCL12)and Chemokine(C-C motif)ligand 2(CCL22),in serving as signaling molecules to connect the MI-induced heart damage to the pro-depressive changes in brain during the post-MI period.Future in-depth investigations into this chemokine hypothesis will be instrumental in developing new chemokine-targeted therapies for better management of the cardiac patients suffering from post-MI depression.展开更多
基金supported by University of Macao,China,Nos.MYRG2022-00054-FHS and MYRG-GRG2023-00038-FHS-UMDF(to ZY)the Macao Science and Technology Development Fund,China,Nos.FDCT0048/2021/AGJ and FDCT0020/2019/AMJ and FDCT 0011/2018/A1(to ZY)Natural Science Foundation of Guangdong Province of China,No.EF017/FHS-YZ/2021/GDSTC(to ZY)。
文摘To investigate the mechanisms underlying the onset and progression of ischemic stroke,some methods have been proposed that can simultaneously monitor and create embolisms in the animal cerebral cortex.However,these methods often require complex systems and the effect of age on cerebral embolism has not been adequately studied,although ischemic stroke is strongly age-related.In this study,we propose an optical-resolution photoacoustic microscopy-based visualized photothrombosis methodology to create and monitor ischemic stroke in mice simultaneously using a 532 nm pulsed laser.We observed the molding process in mice of different ages and presented age-dependent vascular embolism differentiation.Moreover,we integrated optical coherence tomography angiography to investigate age-associated trends in cerebrovascular variability following a stroke.Our imaging data and quantitative analyses underscore the differential cerebrovascular responses to stroke in mice of different ages,thereby highlighting the technique's potential for evaluating cerebrovascular health and unraveling age-related mechanisms involved in ischemic strokes.
基金the National Natural Science Foundationof China, No. 30471774the Program for New Century Excellent Talents in University, Ministry of Education,China, No. NCET-05-0831
文摘This study demonstrated that damage to the cerebral microvasculature, the formation of microthrombi and swelling of vascular endothelial cells occur early and peak 12 hours after injury in a rat model of diffuse axonal injury. Moreover, these pathological changes were most evident in the cerebral cortex. Cerebral microcirculatory dysfunction peaked later and had a shorter duration than axonal injury. In addition, the radioactive imaging agent, 99Tcm-4, 9-diaza-2, 3, 10, 10- tetramethyldodecan-2, 11 -dione dioxime, was used to visualize the dynamic changes that occur in tissue with cerebral hypoxia. The results demonstrated that cerebral hypoxia occurs at an early stage in diffuse axonal injury. Cerebral hypoxia was evident 12 hours after injury and declined slightly 24 hours after injury, but was significantly higher than in the control group. The pathological changes that underpin microcirculatory dysfunction did not occur at the same time as axonal injury, but did occur simultaneously with neuronal injury. Cerebral hypoxia plays a key role in promoting the secondary brain injury that occurs after diffuse axonal injury.
基金the support of the Joint Funds of the Natural Science Foundation of Hubei Province(2022CFD130)the Technology Innovation Project of Hubei Province(Key Program,No.2023BEB010)+1 种基金the Key Research and Development Program of Hubei Province(No.2021BGD015)the Knowledge Innovation Project of Wuhan(No.2022010801010259).
文摘An experimental investigation into the thermal conductivity of CF-SiC two-phase composite asphalt concrete is presented.The main objective of this study was to verify the possibility of using SiC powder instead of mineral powder as the thermal conductive filler to prepare a new type of asphalt concrete and improve the efficiency of electrothermal snow and ice melting systems accordingly.The thermal conductivity of asphalt concrete prepared with different thermally conductive fillers was tested by a transient plane source method,and the related performances were measured.Then the temperature rise rate and surface temperature were studied through field heating tests.Finally,the actual ice melting efficiency of the thermally conductive asphalt concrete was evaluated using an effective electrothermal system.As shown by the experimental results,the composite made of SiC powder and carbon fiber has a high thermal conductivity.When SiC replaces mineral powder,the thermal conductivity of the asphalt mixture increases first and then decreases with the increase of carbon fiber content.In the present study,in particular,the thermal conductivity attained a peak when the carbon fiber content was 0.2%of the aggregate mass.
文摘Acute myocardial infarction(MI)remains one of the leading causes of mortality and morbidity in the global communities.A prevailing topic that has attracted increasing attentions over the past few decades is the so-called heart-brain interaction,in particular following a major traumatic event such as MI.Increased prevalence of depression and other mental disorders has been recognized in cardiac patients after MI,coronary catheterization,or cardiothoracic surgeries.In this review,we focus on the potential pathogenic mechanisms and pre-clinical transcriptomic evidence for identifying potential mediators of post-MI depression.We first summarize the conventional mechanistic understanding that leads to the current clinical management of post-MI depression with the use of selective serotonin reuptake inhibitors(SSRIs)and cognitive behavior and exercise therapies.We further envisage a possible role played by certain chemokines,e.g.,Chemokine(C-X-C motif)ligand 12(CXCL12)and Chemokine(C-C motif)ligand 2(CCL22),in serving as signaling molecules to connect the MI-induced heart damage to the pro-depressive changes in brain during the post-MI period.Future in-depth investigations into this chemokine hypothesis will be instrumental in developing new chemokine-targeted therapies for better management of the cardiac patients suffering from post-MI depression.
