Dopaminergic(DA)neuron-like cells obtained through direct reprogramming of primary human fibroblasts offer exciting opportunities for treatment of Parkinson’s disease.A significant obstacle is the low efficiency of c...Dopaminergic(DA)neuron-like cells obtained through direct reprogramming of primary human fibroblasts offer exciting opportunities for treatment of Parkinson’s disease.A significant obstacle is the low efficiency of conversion during the reprogramming process.Here,we demonstrate that the suppression of p53 significantly enhances the efficiency of transcription factor-mediated conversion of human fibroblasts into functional dopaminergic neurons.In particular,blocking p53 activity using a dominant-negative p53(p53-DN)in IMR90 cells increases the conversion efficiency by 5–20 fold.The induced DA neuron-like cells exhibit dopamine neuron-specific gene expression,significant dopamine uptake and production capacities,and enables symptomatic relief in a rat Parkinson’s disease model.Taken together,our findings suggest that p53 is a critical barrier in direct reprogramming of fibroblast into dopaminergic neurons.展开更多
The generation of functional retinal pigment epithelium （RPE） is of great therapeutic interest to the field of regenerative medicine and may provide possible cures for retinal degenerative diseases, including age-re...The generation of functional retinal pigment epithelium （RPE） is of great therapeutic interest to the field of regenerative medicine and may provide possible cures for retinal degenerative diseases, including age-related macular degeneration （AMD）. Although RPE cells can be produced from either embryonic stem cells or induced pluripotent stem cells, direct cell reprogramming driven by lineage-determining transcription factors provides an immediate route to their generation. By monitoring a human RPE specific Bestl：：GFP reporter, we report the conversion of human fibroblasts into RPE lineage using defined sets of transcription factors. We found that Bestl：：GFP positive cells formed colonies and exhibited morphological and molecular features of early stage RPE cells. Moreover, they were able to obtain pigmen- tation upon activation of Retinoic acid （RA） and Sonic Hedgehog （SHH） signaling pathways. Our study not only established an ideal platform to investigate the tran- scriptional network regulating the RPE cell fate deter- mination, but also provided an alternative strategy to generate functional RPE cells that complement the useof pluripotent stem cells for disease modeling, drug screening, and cell therapy of retinal degeneration.展开更多
Direct conversion of methane using a metal-loaded ZSM-5 zeolite prepared viaacidic ion exchange was investigated to elucidate the roles of metal and acidity in the formation ofliquid hydrocarbons. ZSM-5 (SiO_2/Al_2O_3...Direct conversion of methane using a metal-loaded ZSM-5 zeolite prepared viaacidic ion exchange was investigated to elucidate the roles of metal and acidity in the formation ofliquid hydrocarbons. ZSM-5 (SiO_2/Al_2O_3=30) was loaded with different metals (Cr, Cu and Ga)according to the acidic ion-exchange method to produce metal-loaded ZSM-5 zeolite catalysts. XRD,NMR, FT-IR and N_2 adsorption analyses indicated that Cr and Ga species managed to occupy thealuminum positions in the ZSM-5 framework. In addition, Cr species were deposited in the pores ofthe structure. However, Cu oxides were deposited on the surface and in the mesopores of the ZSM-5zeolite. An acidity study using TPD-NH_3, FT-IR, and IR-pyridine analyses revealed that the totalnumber of acid sites and the strengths of the Broensted and Lewis acid sites were significantlydifferent after the acidic ion exchange treatment. Cu loaded HZSM-5 is a potential catalyst fordirect conversion of methane to liquid hydrocarbons. The successful production of gasoline via thedirect conversion of methane depends on the amount of aluminum in the zeolite framework and thestrength of the Broensted acid sites.展开更多
The recycling and reutilization of spent lithium-ion batteries(LIBs)have become an important measure to alleviate problems like resource scarcity and environmental pollution.Although some progress has been made,batter...The recycling and reutilization of spent lithium-ion batteries(LIBs)have become an important measure to alleviate problems like resource scarcity and environmental pollution.Although some progress has been made,battery recycling technology still faces challenges in terms of efficiency,effectiveness and environmental sustainability.This review aims to systematically review and analyze the current status of spent LIB recycling,and conduct a detailed comparison and evaluation of different recycling processes.In addition,this review introduces emerging recycling techniques,including deep eutectic solvents,molten salt roasting,and direct regeneration,with the intent of enhancing recycling efficiency and diminishing environmental repercussions.Furthermore,to increase the added value of recycled materials,this review proposes the concept of upgrading recycled materials into high value-added functional materials,such as catalysts,adsorbents,and graphene.Through life cycle assessment,the paper also explores the economic and environmental impacts of current battery recycling and highlights the importance that future recycling technologies should achieve a balance between recycling efficiency,economics and environmental benefits.Finally,this review outlines the opportunities and challenges of recycling key materials for next-generation batteries,and proposes relevant policy recommendations to promote the green and sustainable development of batteries,circular economy,and ecological civilization.展开更多
The effect of copper concentration on the performance of the catalytic reaction between silicon and methyl chloride was investigated using online gas chromatogram. The catalyst concentration greatly influences various...The effect of copper concentration on the performance of the catalytic reaction between silicon and methyl chloride was investigated using online gas chromatogram. The catalyst concentration greatly influences various aspects of the direct organosilane synthesis process, including the reaction rate, the selec- tivity, and the silicon conversion. The reaction activity and the silicon conversion increase as the catalyst concentration increases. However, the reaction selectivity decreases for the catalyst concentrations more .than 9 wt.%. The cross-sections of deactivated contact mass particles were observed by optical microscopy and analyzed by scanning electron microscope combined with energy dispersive X-ray detector （SEM-EDX） The observations showed that a textured substance formed on the original flat surface of the silicon particles after deactivation with copper only in a shallow surface layer of the contact mass. This indicates that the copper diffusion is the rate limiting step which causes the reaction deactivation.展开更多
Developing high-performance energy storage and conversion(ESC)device relies on both the utilization of good constituent materials and rational design of assembly structure.Graphene-based materials,due to their superio...Developing high-performance energy storage and conversion(ESC)device relies on both the utilization of good constituent materials and rational design of assembly structure.Graphene-based materials,due to their superior properties like high electrical/thermal conductivity,large surface area,and unique optical properties,have been extensively reported for ESC applications.The emerging three-dimensional(3D)printing techniques,especially extrusion-based direct ink writing technique,have brought a revolutionary improvement in structure control accuracy and designing capability to graphene-based macro-assemblies,triggering a boost in functionalities and performances of graphene-based ESC devices.In these circumstances,understanding the very recent progress of 3Dprinted graphene materials and their design philosophy to bring new concepts for material designs and address the requirements for high-performance ESC devices are urgently important.In this review,we aim to outline recent developments in 3D printing of graphene-based materials and their applications in ESC applications.Basic requirements and theoretical analysis for preparation printable inks are discussed,as well as feasible GO ink preparation strategies in existing literatures.The representative explorations of 3D-printed graphenematerials in ESC applications like batteries,supercapacitors,solar steam generators,and electro-thermal conversion are also reviewed.This study attempts to provide a comprehensive overview of the progresses and limitations of present 3D printed graphenematerials,and seeks to enlighten the opportunities and orientations of future research in this field.展开更多
Neurogenesis is a tightly regulated process in time and space both in the developing embryo and in adult neurogenic niches.A drastic change in the transcriptome and proteome of radial glial cells or neural stem cells ...Neurogenesis is a tightly regulated process in time and space both in the developing embryo and in adult neurogenic niches.A drastic change in the transcriptome and proteome of radial glial cells or neural stem cells towards the neuronal state is achieved due to sophisticated mechanisms of epigenetic,transcriptional,and post-transcriptional regulation.Understanding these neurogenic mechanisms is of major importance,not only for shedding light on very complex and crucial developmental processes,but also for the identification of putative reprogramming factors,that harbor hierarchically central regulatory roles in the course of neurogenesis and bare thus the capacity to drive direct reprogramming towards the neuronal fate.The major transcriptional programs that orchestrate the neurogenic process have been the focus of research for many years and key neurogenic transcription factors,as well as repressor complexes,have been identified and employed in direct reprogramming protocols to convert non-neuronal cells,into functional neurons.The post-transcriptional regulation of gene expression during nervous system development has emerged as another important and intricate regulatory layer,strongly contributing to the complexity of the mechanisms controlling neurogenesis and neuronal function.In particular,recent advances are highlighting the importance of specific RNA binding proteins that control major steps of mRNA life cycle during neurogenesis,such as alternative splicing,polyadenylation,stability,and translation.Apart from the RNA binding proteins,microRNAs,a class of small non-coding RNAs that block the translation of their target mRNAs,have also been shown to play crucial roles in all the stages of the neurogenic process,from neural stem/progenitor cell proliferation,neuronal differentiation and migration,to functional maturation.Here,we provide an overview of the most prominent post-transcriptional mechanisms mediated by RNA binding proteins and microRNAs during the neurogenic process,giving particular emphasis on展开更多
Integrated optical chips have already been established for application in optical communication.They also offer interesting future perspectives for integrated quantum optics on a chip.At present,however,they are mostl...Integrated optical chips have already been established for application in optical communication.They also offer interesting future perspectives for integrated quantum optics on a chip.At present,however,they are mostly fabricated using essentially planar fabrication approaches like electron-beam lithography or UV optical lithography.Many further design options would arise if one had complete fabrication freedom in regard to the third dimension normal to the chip without having to give up the virtues and the know-how of existing planar fabrication technologies.As a step in this direction,we here use three-dimensional dip-in direct-laser-writing optical lithography to fabricate three-dimensional polymeric functional devices on pre-fabricated planar optical chips containing Si3N4 waveguides as well as grating couplers made by standard electron-beam lithography.The first example is a polymeric dielectric rectangular-shaped waveguide which is connected to Si3N4 waveguides and that is adiabatically twisted along its axis to achieve geometrical rotation of linear polarization on the chip.The rotator’s broadband performance at around 1550 nm wavelength is verified by polarization-dependent grating couplers.Such polarization rotation on the optical chip cannot easily be achieved by other means.The second example is a whispering-gallery-mode optical resonator connected to Si_(3)N_(4) waveguides on the chip via polymeric waveguides.By mechanically connecting the latter to the disk,we can control the coupling to the resonator and,at the same time,guarantee mechanical stability of the three-dimensional architecture on the chip.展开更多
基金supported in part by grants from the US National Institutes of Health(CA131408,CA136748,CA155270,ES024015)to Li Chuan-Yuan
文摘Dopaminergic(DA)neuron-like cells obtained through direct reprogramming of primary human fibroblasts offer exciting opportunities for treatment of Parkinson’s disease.A significant obstacle is the low efficiency of conversion during the reprogramming process.Here,we demonstrate that the suppression of p53 significantly enhances the efficiency of transcription factor-mediated conversion of human fibroblasts into functional dopaminergic neurons.In particular,blocking p53 activity using a dominant-negative p53(p53-DN)in IMR90 cells increases the conversion efficiency by 5–20 fold.The induced DA neuron-like cells exhibit dopamine neuron-specific gene expression,significant dopamine uptake and production capacities,and enables symptomatic relief in a rat Parkinson’s disease model.Taken together,our findings suggest that p53 is a critical barrier in direct reprogramming of fibroblast into dopaminergic neurons.
文摘The generation of functional retinal pigment epithelium （RPE） is of great therapeutic interest to the field of regenerative medicine and may provide possible cures for retinal degenerative diseases, including age-related macular degeneration （AMD）. Although RPE cells can be produced from either embryonic stem cells or induced pluripotent stem cells, direct cell reprogramming driven by lineage-determining transcription factors provides an immediate route to their generation. By monitoring a human RPE specific Bestl：：GFP reporter, we report the conversion of human fibroblasts into RPE lineage using defined sets of transcription factors. We found that Bestl：：GFP positive cells formed colonies and exhibited morphological and molecular features of early stage RPE cells. Moreover, they were able to obtain pigmen- tation upon activation of Retinoic acid （RA） and Sonic Hedgehog （SHH） signaling pathways. Our study not only established an ideal platform to investigate the tran- scriptional network regulating the RPE cell fate deter- mination, but also provided an alternative strategy to generate functional RPE cells that complement the useof pluripotent stem cells for disease modeling, drug screening, and cell therapy of retinal degeneration.
文摘Direct conversion of methane using a metal-loaded ZSM-5 zeolite prepared viaacidic ion exchange was investigated to elucidate the roles of metal and acidity in the formation ofliquid hydrocarbons. ZSM-5 (SiO_2/Al_2O_3=30) was loaded with different metals (Cr, Cu and Ga)according to the acidic ion-exchange method to produce metal-loaded ZSM-5 zeolite catalysts. XRD,NMR, FT-IR and N_2 adsorption analyses indicated that Cr and Ga species managed to occupy thealuminum positions in the ZSM-5 framework. In addition, Cr species were deposited in the pores ofthe structure. However, Cu oxides were deposited on the surface and in the mesopores of the ZSM-5zeolite. An acidity study using TPD-NH_3, FT-IR, and IR-pyridine analyses revealed that the totalnumber of acid sites and the strengths of the Broensted and Lewis acid sites were significantlydifferent after the acidic ion exchange treatment. Cu loaded HZSM-5 is a potential catalyst fordirect conversion of methane to liquid hydrocarbons. The successful production of gasoline via thedirect conversion of methane depends on the amount of aluminum in the zeolite framework and thestrength of the Broensted acid sites.
基金financially supported by the National Natural Science Foundation of China(NSFC)(52274295)the Natural Science Foundation of Hebei Province(E2020501001,E2021501029,A2021501007,E2022501028,E2022501029)+5 种基金the Natural Science Foundation-Steel,the Iron Foundation of Hebei Province(No.E2022501030)the Performance subsidy fund for Key Laboratory of Dielectric and Electrolyte Functional Material Hebei Province(22567627H)the Science and Technology Project of Hebei Education Department(ZD2022158)the Central Guided Local Science and Technology Development Fund Project of Hebei province(226Z4401G)the China Scholarship Council(No.202206080061,202206050119)the 2023 Hebei Provincial Postgraduate Student Innovation Ability training funding project(CXZZSS2023195)。
文摘The recycling and reutilization of spent lithium-ion batteries(LIBs)have become an important measure to alleviate problems like resource scarcity and environmental pollution.Although some progress has been made,battery recycling technology still faces challenges in terms of efficiency,effectiveness and environmental sustainability.This review aims to systematically review and analyze the current status of spent LIB recycling,and conduct a detailed comparison and evaluation of different recycling processes.In addition,this review introduces emerging recycling techniques,including deep eutectic solvents,molten salt roasting,and direct regeneration,with the intent of enhancing recycling efficiency and diminishing environmental repercussions.Furthermore,to increase the added value of recycled materials,this review proposes the concept of upgrading recycled materials into high value-added functional materials,such as catalysts,adsorbents,and graphene.Through life cycle assessment,the paper also explores the economic and environmental impacts of current battery recycling and highlights the importance that future recycling technologies should achieve a balance between recycling efficiency,economics and environmental benefits.Finally,this review outlines the opportunities and challenges of recycling key materials for next-generation batteries,and proposes relevant policy recommendations to promote the green and sustainable development of batteries,circular economy,and ecological civilization.
文摘The effect of copper concentration on the performance of the catalytic reaction between silicon and methyl chloride was investigated using online gas chromatogram. The catalyst concentration greatly influences various aspects of the direct organosilane synthesis process, including the reaction rate, the selec- tivity, and the silicon conversion. The reaction activity and the silicon conversion increase as the catalyst concentration increases. However, the reaction selectivity decreases for the catalyst concentrations more .than 9 wt.%. The cross-sections of deactivated contact mass particles were observed by optical microscopy and analyzed by scanning electron microscope combined with energy dispersive X-ray detector （SEM-EDX） The observations showed that a textured substance formed on the original flat surface of the silicon particles after deactivation with copper only in a shallow surface layer of the contact mass. This indicates that the copper diffusion is the rate limiting step which causes the reaction deactivation.
基金NationalNatural Science Foundation of China,Grant/Award Numbers:52090030,51533008,51973191,51703194,51803177China Postdoctoral Science Foundation,Grant/Award Number:2021M692772+4 种基金National Key R&D Program of China,Grant/Award Number:2016YFA0200200FundamentalResearch Funds for the CentralUniversities,Grant/Award Numbers:30920041106,K20200060,30919011271Hundred Talents Programof Zhejiang University,Grant/Award Number:188020*194231701/113Key Research and Development Plan of Zhejiang Province,Grant/Award Number:2018C01049KeyLaboratory of Novel Adsorption and Separation Materialsand Application Technology of Zhejiang Province,Grant/AwardNumber:512301-I21502。
文摘Developing high-performance energy storage and conversion(ESC)device relies on both the utilization of good constituent materials and rational design of assembly structure.Graphene-based materials,due to their superior properties like high electrical/thermal conductivity,large surface area,and unique optical properties,have been extensively reported for ESC applications.The emerging three-dimensional(3D)printing techniques,especially extrusion-based direct ink writing technique,have brought a revolutionary improvement in structure control accuracy and designing capability to graphene-based macro-assemblies,triggering a boost in functionalities and performances of graphene-based ESC devices.In these circumstances,understanding the very recent progress of 3Dprinted graphene materials and their design philosophy to bring new concepts for material designs and address the requirements for high-performance ESC devices are urgently important.In this review,we aim to outline recent developments in 3D printing of graphene-based materials and their applications in ESC applications.Basic requirements and theoretical analysis for preparation printable inks are discussed,as well as feasible GO ink preparation strategies in existing literatures.The representative explorations of 3D-printed graphenematerials in ESC applications like batteries,supercapacitors,solar steam generators,and electro-thermal conversion are also reviewed.This study attempts to provide a comprehensive overview of the progresses and limitations of present 3D printed graphenematerials,and seeks to enlighten the opportunities and orientations of future research in this field.
基金supported by Stavros Niarhos FoundationGreek‘Flagship Action for the Study of Neurodegenerative Diseases on the Basis of Precision Medicine’(to DT).
文摘Neurogenesis is a tightly regulated process in time and space both in the developing embryo and in adult neurogenic niches.A drastic change in the transcriptome and proteome of radial glial cells or neural stem cells towards the neuronal state is achieved due to sophisticated mechanisms of epigenetic,transcriptional,and post-transcriptional regulation.Understanding these neurogenic mechanisms is of major importance,not only for shedding light on very complex and crucial developmental processes,but also for the identification of putative reprogramming factors,that harbor hierarchically central regulatory roles in the course of neurogenesis and bare thus the capacity to drive direct reprogramming towards the neuronal fate.The major transcriptional programs that orchestrate the neurogenic process have been the focus of research for many years and key neurogenic transcription factors,as well as repressor complexes,have been identified and employed in direct reprogramming protocols to convert non-neuronal cells,into functional neurons.The post-transcriptional regulation of gene expression during nervous system development has emerged as another important and intricate regulatory layer,strongly contributing to the complexity of the mechanisms controlling neurogenesis and neuronal function.In particular,recent advances are highlighting the importance of specific RNA binding proteins that control major steps of mRNA life cycle during neurogenesis,such as alternative splicing,polyadenylation,stability,and translation.Apart from the RNA binding proteins,microRNAs,a class of small non-coding RNAs that block the translation of their target mRNAs,have also been shown to play crucial roles in all the stages of the neurogenic process,from neural stem/progenitor cell proliferation,neuronal differentiation and migration,to functional maturation.Here,we provide an overview of the most prominent post-transcriptional mechanisms mediated by RNA binding proteins and microRNAs during the neurogenic process,giving particular emphasis on
基金We acknowledges support by DFG grant PE 1832/1-1 and PE 1832/2-1the Helmholtz Society through grant HIRG-0005.
文摘Integrated optical chips have already been established for application in optical communication.They also offer interesting future perspectives for integrated quantum optics on a chip.At present,however,they are mostly fabricated using essentially planar fabrication approaches like electron-beam lithography or UV optical lithography.Many further design options would arise if one had complete fabrication freedom in regard to the third dimension normal to the chip without having to give up the virtues and the know-how of existing planar fabrication technologies.As a step in this direction,we here use three-dimensional dip-in direct-laser-writing optical lithography to fabricate three-dimensional polymeric functional devices on pre-fabricated planar optical chips containing Si3N4 waveguides as well as grating couplers made by standard electron-beam lithography.The first example is a polymeric dielectric rectangular-shaped waveguide which is connected to Si3N4 waveguides and that is adiabatically twisted along its axis to achieve geometrical rotation of linear polarization on the chip.The rotator’s broadband performance at around 1550 nm wavelength is verified by polarization-dependent grating couplers.Such polarization rotation on the optical chip cannot easily be achieved by other means.The second example is a whispering-gallery-mode optical resonator connected to Si_(3)N_(4) waveguides on the chip via polymeric waveguides.By mechanically connecting the latter to the disk,we can control the coupling to the resonator and,at the same time,guarantee mechanical stability of the three-dimensional architecture on the chip.
