Glial cells play an essential part in the neuron system.They can not only serve as structural blocks in the human brain but also participate in many biological processes.Extensive studies have shown that astrocytes an...Glial cells play an essential part in the neuron system.They can not only serve as structural blocks in the human brain but also participate in many biological processes.Extensive studies have shown that astrocytes and microglia play an important role in neurodegenerative diseases,such as Alzheimer's disease,Parkinson's disease,Huntington's disease,as well as glioma,epilepsy,ischemic stroke,and infections.Positron emission tomography is a functional imaging technique providing molecular-level information before anatomic changes are visible and has been widely used in many above-mentioned diseases.In this review,we focus on the positron emission tomography tracers used in pathologies related to glial cells,such as glioma,Alzheimer's disease,and neuroinflammation.展开更多
Understanding the effect of H_(2)O adsorption on reactant activation is of great importance in heterogeneous catalysis,which remains a grand challenge particularly in oxide catalyst systems with structural complexity....Understanding the effect of H_(2)O adsorption on reactant activation is of great importance in heterogeneous catalysis,which remains a grand challenge particularly in oxide catalyst systems with structural complexity.Herein,the effect of D_(2)O adsorption on D_(2)activation over MgO nanocatalysts at different temperatures has been investigated by transmission Fourier transform infrared(FT-IR)and temperature-programmed desorption(TPD).Two sets of hydride and hydroxyl species produced from D_(2)dissociation at more active and less active Mg-O pairs can be observed by FT-IR,which all desorb via the product of D_(2)as confirmed by TPD experiments.We find that the physically adsorbed D_(2)O overlayer does not affect the dissociation of D_(2)since D_(2)may pass through the molecular layer and access the surface-active sites.When D_(2)O is partially dissociated on the MgO surface,D_(2)can only dissociate at the remaining active sites until that dissociated-ODw groups from D_(2)O occupy all active sites.These findings provide a fundamental understanding of the effect of water adsorption on D_(2)activation on oxide catalysts.展开更多
Cultivated strawberry(Fragaria×ananassa),a world-famous fruit,is subjected to rapid softening during ripening,resulting in a shorter shelf life and severe economic losses during storage and transportation.However...Cultivated strawberry(Fragaria×ananassa),a world-famous fruit,is subjected to rapid softening during ripening,resulting in a shorter shelf life and severe economic losses during storage and transportation.However,there is limited understanding of the molecular mechanism underlying differences in fruit firmness during ripening and postharvest among cultivated strawberries.Here,we explored this molecular mechanism by comparing three cultivated strawberries via firmness measurement,transcriptome analysis,quantitative real-time polymerase chain reaction,and correlation analysis,and revealed FaEXP7,FaPG2,FaPLA,and Faβ-Gal4 as potential softening activators expressed before harvest to determine fruit with more softened texture and shorter shelf life,and that extremely high expression levels of FaCEL1-1 and FaCEL1-3 during ripening might be accelerators to intensify this situation.Additionally,both the enzyme activities of FaCEL and the expression pattern of FaCEL1-3 showed a significantly negative correlation with fruit firmness after harvest,suggesting that FaCEL1-3 might play a key role in promoting strawberry fruit softening not only during ripening but also postharvest.These results showed that the difference in fruit firmness and shelf life among cultivated strawberries was controlled by the temporal expression pattern of a legion of cell wall-associated genes during ripening and postharvest.展开更多
基金This work was supported by the Key Laboratory of Biomedical Engineering of Hainan Province under Opening Foundation 2022001.
文摘Glial cells play an essential part in the neuron system.They can not only serve as structural blocks in the human brain but also participate in many biological processes.Extensive studies have shown that astrocytes and microglia play an important role in neurodegenerative diseases,such as Alzheimer's disease,Parkinson's disease,Huntington's disease,as well as glioma,epilepsy,ischemic stroke,and infections.Positron emission tomography is a functional imaging technique providing molecular-level information before anatomic changes are visible and has been widely used in many above-mentioned diseases.In this review,we focus on the positron emission tomography tracers used in pathologies related to glial cells,such as glioma,Alzheimer's disease,and neuroinflammation.
基金This work was financially supported by the National Key R&D Program of China(Nos.2021YFA1502800,2022YFA1504800 and 2022YFA1504500)the National Natural Science Foundation of China(Nos.91945302,22272162,22288201 and 21825203).
文摘Understanding the effect of H_(2)O adsorption on reactant activation is of great importance in heterogeneous catalysis,which remains a grand challenge particularly in oxide catalyst systems with structural complexity.Herein,the effect of D_(2)O adsorption on D_(2)activation over MgO nanocatalysts at different temperatures has been investigated by transmission Fourier transform infrared(FT-IR)and temperature-programmed desorption(TPD).Two sets of hydride and hydroxyl species produced from D_(2)dissociation at more active and less active Mg-O pairs can be observed by FT-IR,which all desorb via the product of D_(2)as confirmed by TPD experiments.We find that the physically adsorbed D_(2)O overlayer does not affect the dissociation of D_(2)since D_(2)may pass through the molecular layer and access the surface-active sites.When D_(2)O is partially dissociated on the MgO surface,D_(2)can only dissociate at the remaining active sites until that dissociated-ODw groups from D_(2)O occupy all active sites.These findings provide a fundamental understanding of the effect of water adsorption on D_(2)activation on oxide catalysts.
基金supported by the Key Research and Development Program of Shandong Province,China(No.2022TZXD0022)the National Natural Science Foundation of China(Nos.32102345 and 32002004)the 111 Project(No.B17039),China.
文摘Cultivated strawberry(Fragaria×ananassa),a world-famous fruit,is subjected to rapid softening during ripening,resulting in a shorter shelf life and severe economic losses during storage and transportation.However,there is limited understanding of the molecular mechanism underlying differences in fruit firmness during ripening and postharvest among cultivated strawberries.Here,we explored this molecular mechanism by comparing three cultivated strawberries via firmness measurement,transcriptome analysis,quantitative real-time polymerase chain reaction,and correlation analysis,and revealed FaEXP7,FaPG2,FaPLA,and Faβ-Gal4 as potential softening activators expressed before harvest to determine fruit with more softened texture and shorter shelf life,and that extremely high expression levels of FaCEL1-1 and FaCEL1-3 during ripening might be accelerators to intensify this situation.Additionally,both the enzyme activities of FaCEL and the expression pattern of FaCEL1-3 showed a significantly negative correlation with fruit firmness after harvest,suggesting that FaCEL1-3 might play a key role in promoting strawberry fruit softening not only during ripening but also postharvest.These results showed that the difference in fruit firmness and shelf life among cultivated strawberries was controlled by the temporal expression pattern of a legion of cell wall-associated genes during ripening and postharvest.