Developing efficient electrocatalysts for converting dinitrogen to ammonia through electrocatalysis is of significance to the decentralized ammonia production. Here, through high-throughput density functional theory c...Developing efficient electrocatalysts for converting dinitrogen to ammonia through electrocatalysis is of significance to the decentralized ammonia production. Here, through high-throughput density functional theory calculations, we demonstrated that the interfacial modulation of hexagonal boron nitride/graphene(hBN-graphene) could sufficiently improve the catalytic activity of the single transition metal atom catalysts for nitrogen reduction reaction(NRR). It was revealed that Re@hBN-graphene and Os@hBN-graphene possessed remarkable NRR catalytic activity with low limiting potentials of 0.29 V and 0.33 V, respectively. Furthermore, the mechanism of the enhanced catalytic activity was investigated based on various descriptors of the adsorption energies of intermediates, where the synergistic effect of hBN and graphene in the hybrid substrate was found to play a key role. Motivated by the synergistic effect of hybrid substrate in single-atom catalysts, a novel strategy was proposed to efficiently design dual-atom catalysts by integrating the merits of both metal components. The as-designed dual-atom catalyst Fe-Mo@hBN exhibited more excellent NRR catalytic performance with a limiting potential of 0.17 V, manifesting the solidity of the design strategy. Our findings open new avenues for the search of heterostructure substrates for single-atom catalysts and the efficient design of dualatom catalysts for NRR.展开更多
In the present study,two Ni/YSZ anodes with different volume ratios of Ni and YSZ,30:70 and 45:55 vol%,are operated in dry methane under open circuit and polarized conditions.Three-dimensional(3D)Ni/YSZ microstructure...In the present study,two Ni/YSZ anodes with different volume ratios of Ni and YSZ,30:70 and 45:55 vol%,are operated in dry methane under open circuit and polarized conditions.Three-dimensional(3D)Ni/YSZ microstructures after carbon deposition are reconstructed by the focused ion beam-scanning electron microscopy(FIB-SEM)with the help of machine learning segmentation.From the reconstructed mircostructures,volume fraction,connectivity,three phase boundary(TPB)density,and tortuosity are quantified.In addition,local carbon microstructures are quantitatively reconstructed,and the effect of polarization on carbon morphology is investigated.It is demonstrated that Ni surface in the vicinity of active TPB near the electrolyte is free from carbon formation,while remaining Ni surface at some distances from TPB exhibits severe carbon deposition.In average,total amount of carbon deposition is larger near the electrolyte.These observations imply complex interplay between the electrochemical steam generation and methane cracking on Ni surface which take place very locally near the active TPB.展开更多
Mitochondria are well cha racterized by their fundamental functions in regulating cellular homeostasis,including energy and iron metabolism.These functions are essential in neurons with high metabolic demands and elon...Mitochondria are well cha racterized by their fundamental functions in regulating cellular homeostasis,including energy and iron metabolism.These functions are essential in neurons with high metabolic demands and elongated neuronal processes.Mitochondria dynamically change morphology,localization,and activity to match neurons'spatial and temporal demands.Mitochondrial dysfunctions have been associated with many neurological disorders.展开更多
BACKGROUND： Many methods have been attempted to repair nerves following spinal cord injury, including peripheral nerve transplantation, Schwann cell transplantation, olfactory ensheathing cell transplantation, and em...BACKGROUND： Many methods have been attempted to repair nerves following spinal cord injury, including peripheral nerve transplantation, Schwann cell transplantation, olfactory ensheathing cell transplantation, and embryonic neural tissue transplantation. However, there is a need for improved outcomes. OBJECTIVE： To investigate the repair feasibility for rat spinal cord injury using human neural stem cells （hNSCs） genetically modified by lentivirus to express neurotrophin-3. DESIGN, TIME AND SETTING： In vitro cell biological experiment and in vivo randomized, controlled genetic engineering experiment were performed at the Third Military Medical University of Chinese PLA and First People＇s Hospital of Yibin, China from March 2006 to December 2007. MATERIALS： A total of 64 adult, female, Wistar rats were used for the in vivo study. Of them, 48 rats were used to establish models of spinal cord hemisection, and were subsequently equally and randomly assigned to model, genetically modified hNSC, and normal hNSC groups. The remaining 16 rats served as normal controls. METHODS： hNSCs were in vitro genetically modified by lentivirus to secrete both green fluorescence protein and neurotrophin-3. Neurotrophin-3 expression was measured by Western blot. Genetically modified hNSC or normal hNSC suspension （5 × 10^5） was injected into the rat spinal cord following T10 spinal cord hemisection. A total of 5μL Dulbecco＇s-modified Eagle＇s medium was infused into the rat spinal cord in the model grop. Transgene expression and survival of transplanted hNSCs were determined by immunohistochemistry. Motor function was evaluated using the Basso, Beattie, and Bresnahan （BBB） scale. MAIN OUTCOME MEASURES： The following parameters were measured： expression of neurotrophin-3 produced by genetically modified hNSCs, transgene expression and survival of hNSCs in rats, motor function in rats. RESULTS： hNSCs were successfully genetically modified by lentivirus to stably express neurotrophin-3. The transplanted hNSCs primarily gathered at, or around, the injection site two weeks following transplantation, and gradually migrated towards the surrounding tissue. Transplanted hNSCs were observed 7.0-8.0 mm away from the injection site. In addition, hNSCs were observed 10 weeks after transplantation. At week 4, BBB locomotor scores were significantly greater in the genetically modified hNSC and normal hNSC groups, compared with the model group （P 〈 0.05）, and scores were significantly greater in the genetically modified hNSC group compared with the normal hNSC group （P 〈 0.05）. CONCLUSION： hNSCs were genetically modified with lentivirus to stably secrete neurotrophin-3. hNSCs improved motor function recovery in rats following spinal cord injury.展开更多
A series of Cu-Mg-Al hydrotalcites derived oxides with a(Cu+Mg)/Al mole ratio of 3 and varied Cu/Mg mole ratio(from 0.07 to 0.30) were prepared by co-precipitation and calcination methods, then they were introduced to...A series of Cu-Mg-Al hydrotalcites derived oxides with a(Cu+Mg)/Al mole ratio of 3 and varied Cu/Mg mole ratio(from 0.07 to 0.30) were prepared by co-precipitation and calcination methods, then they were introduced to the hydrogenation of furfural in aqueous-phase. Effects of Cu/Mg mole ratio, reaction temperature, initial hydrogen pressure, reaction time and catalyst amount on the conversion rate of furfural as well as the selectivity toward desired product cyclopentanol were systematically investigated. The conversion of furfural over calcined hydrotalcite catalyst with a Cu/Mg mole ratio of 0.2 was up to 98.5% when the reaction was carried out under 140 ?C and the initial hydrogen pressure of 4 MPa for 10 h, while the selectivity toward cyclopentanol was up to 94.8%. The catalysts were characterized by XRD and SEM. XRD diffraction of all the samples showed characteristic pattern of hydrotalcite with varied peak intensity as a result of different Cu content. The catalytic activity was improved gradually with the increase of Cu component in the hydrotalcite.展开更多
Depression is a prevalent mental disorder that is associated with aging and contributes to increased mortality and morbidity.The overall prevalence of geriatric depression with clinically significant symptoms is curre...Depression is a prevalent mental disorder that is associated with aging and contributes to increased mortality and morbidity.The overall prevalence of geriatric depression with clinically significant symptoms is currently on the rise.Recent studies have demonstrated that altered expressions of long non-coding RNAs(lncRNAs)in the brain affect neurodevelopment and manifest modulating functions during the depression.However,most lncRNAs have not yet been studied.Herein,we analyzed the transcriptome of dysregulated lncRNAs to reveal their expressions in a mouse model exhibiting depressive-like behaviors,as well as their corresponding response following antidepressant fluoxetine treatment.A chronic unpredictable mild stress(CUMS)mouse model was applied.A sixweek fluoxetine intervention in CUMS-induced mice attenuated depressive-like behaviors.In addition,differential expression analysis of lncRNAs was performed following RNA-sequencing.A total of 282 lncRNAs(134 up-regulated and 148 down-regulated)were differentially expressed in CUMS-induced mice relative to non-stressed counterparts(P<0.05).Moreover,370 differentially expressed lncRNAs were identified in CUMS-induced mice after fluoxetine intervention.Gene Ontology(GO)analyses showed an association between significantly dysregulated lncRNAs and protein binding,oxygen binding,and transport activity,while the Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis indicated that these dysregulated lncRNAs might be involved in inflammatory response pathways.Fluoxetine effectively ameliorated the symptoms of depression in CUMS-induced mice by regulating the expression of lncRNAs in the hippocampus.The findings herein provide valuable insights into the potential mechanism underlying depression in elderly people.展开更多
Ischemic stroke is a serious cerebrovascular disease with high morbidity and mortality.As a result of ischemia-reperfusion,a cascade of pathophysiological responses is triggered by the imbalance in metabolic supply an...Ischemic stroke is a serious cerebrovascular disease with high morbidity and mortality.As a result of ischemia-reperfusion,a cascade of pathophysiological responses is triggered by the imbalance in metabolic supply and demand,resulting in cell loss.These cellular injuries follow various molecular mechanisms solely or in combination with this disorder.Mitochondria play a driving role in the pathophysiological processes of ischemic stroke.Once ischemic stroke occurs,damaged cells would respond to such stress through mitophagy.Mitophagy is known as a conservatively selective autophagy,contributing to the removal of excessive protein aggregates and damaged intracellular components,as well as aging mitochondria.Moderate mitophagy may exert neuroprotection against stroke.Several pathways associated with the mitochondrial network collectively contribute to recovering the homeostasis of the neurovascular unit.However,excessive mitophagy would also promote ischemia-reperfusion injury.Therefore,mitophagy is a double-edged sword,which suggests that maximizing the benefits of mitophagy is one of the direction of future efforts.This review emphasized the role of mitophagy in ischemic stroke,and highlighted the crosstalk between mitophagy and apoptosis/necroptosis.展开更多
Natural gas hydrate,oil and gas were all found together in the Qilian Mountain permafrost area,northeast of Qinghai-Tibet Plateau,China.They are closely associated with each other in space,but whether they are in any ...Natural gas hydrate,oil and gas were all found together in the Qilian Mountain permafrost area,northeast of Qinghai-Tibet Plateau,China.They are closely associated with each other in space,but whether they are in any genetic relations are unknown yet.In this paper,a hydrocarbon gas-generation series,gas-fluid migration series and hydrocarbon gas-accumulation series are analyzed to probe the spatial,temporal and genetic relationships among natural natural gas hydrate,oil and gas.The subsequent results show that natural gas hydrate,oil and gas actually form a natural gas hydrate-oil-gas system.Based on the Middle Jurassic and the Upper Triassic hydrocarbon gas-generation series,it is divided into four major sub-systems in the study area:(1)A conventional Upper Triassic gas-bearing sub-system with peak hydrocarbon gas-generation in the late Middle Jurassic;(2)a conventional Middle Jurassic oil-bearing sub-system with low to mature hydrocarbon gas-generation in the late Middle Jurassic;(3)a natural gas hydrate sub-system with main gas source from the Upper Triassic gas-bearing sub-system and minor gas source from the Middle Jurassic oil-bearing sub-system as well as little gas source from the Middle Jurassic coal-bed gas and the microbial gas;(4)a shallower gas sub-system with microbial alteration of the main gas source from the Upper Triassic gas-bearing sub-system.This natural gas hydrate-oil-gas system and its sub-systems are not only theoretical but also practical,and thus they will play an important role in the further exploration of natural gas hydrate,oil and gas,even other energy resources in the study area.展开更多
Co-pyrolysis of lignin and waste plastics,for example polyethylene(PE),has been studied,but related reports are basically on condition optimizations.This study revealed a new perspective on PE-promoted lignin pyrolysi...Co-pyrolysis of lignin and waste plastics,for example polyethylene(PE),has been studied,but related reports are basically on condition optimizations.This study revealed a new perspective on PE-promoted lignin pyrolysis to phenolic monomers with mass transfer and radical explanation.Lignin and PE were first pyrolyzed individually to identify pyrolysis characteristics,pyrolytic products,as well as the suitable copyrolysis temperature.Then,co-pyrolysis of blended lignin/PE with various ratios was investigated.Yields of lignin products reached the maximum under lignin/PE ratio of 1:1,but blended approach always inhibited the production of lignin phenols.This resulted from the poor mass transfer and interactions between lignin and PE,in which PE pyrolysates could easily escape from the particle gaps.While in layered approach,PE pyrolysates had to pass through the lignin layer which contributed to the good interactions with lignin pyrolysis intermediates,thus the yields of lignin-derived products were significantly improved.Interactions between lignin and PE(or their pyrolysates)were mainly radical quenching reactions,and X-ray photoelectron spectrum(XPS)and electron paramagnetic resonance(EPR)of pyrolytic chars were conducted to verify these interactions controlled by mass transfer.The percentage of C]C(sp^(2))and concentration of organic stable radicals in layered lignin/PE char were both the lowest compared with those in blended lignin/PE and lignin char,indicating the stabilization of lignin-derived radicals by PE pyrolysates.Moreover,the spin concentration of radicals in the char from layered char/PE was lower than that in lignin char,which further affirmed the quenching of radicals by PE in the layered co-pyrolysis mode.展开更多
The effect of self-reactivation on the CO_(2) capture capacity of the spent calcium based sorbent was investigated in a dual-fixed bed reactor.The sampled sorbents from the dual-fixed bed reactor were sent for XRD,SEM...The effect of self-reactivation on the CO_(2) capture capacity of the spent calcium based sorbent was investigated in a dual-fixed bed reactor.The sampled sorbents from the dual-fixed bed reactor were sent for XRD,SEM and N_2 adsorption analysis to explain the self-reactivation mechanism.The results show that the CaO in the spent sorbent discharged from the calciner absorbs the vapor in the air to form Ca(OH)_(2) and further Ca(OH)_(2)·2 H_(2) O under environmental conditions,during which process the CO_(2) capture capacity of the spent sorbent can be self-reactivated.The microstructure of the spent sorbent is improved by the self-reactivation process,resulting in more porous microstructure,higher BET surface area and pore volume.Compared with the calcined spent sorbent that has experienced 20 cycles,the pore volume and BET surface area are increased by 6.69 times and 56.3% after self-reactivation when φ=170%.The improved microstructure makes it easier for the CO_(2) diffusion and carbonation reaction in the sorbent.Therefore,the CO_(2) capture capacity of the spent sorbent is enhanced by self-reactivation process.A self-reactivation process coupled with calcium looping process was proposed to reuse the discharged spent calcium based sorbent from the calciner.Higher average carbonation conversion and CO_(2) capture efficiency can be achieved when self-reactivated spent sorbent is used as supplementary sorbent in the calciner rather than fresh CaCO_(3) under the same conditions.展开更多
The chemical looping process,where an oxygen carrier is reduced and oxidized in a cyclic manner,offers a promising option for hydrogen production through splitting water because of the much higher water splitting effi...The chemical looping process,where an oxygen carrier is reduced and oxidized in a cyclic manner,offers a promising option for hydrogen production through splitting water because of the much higher water splitting efficiency than solar electrocatalytic and photocatalytic process.A typical oxygen carrier has to comprise a significant amount of inert support,to maintain stability in multiple redox cycles,thereby resulting in a trade-off between the reaction reactivity and stability.Herein,we proposed the use of ion-conductive yttria-stabilized zirconia(YSZ)support Fe_(2)O_(3)to prepare oxygen carriers materials.The obtained Fe_(2)O_(3)/YSZ composites showed high reactivity and stability.Particularly,Fe_(2)O_(3)/YSZ-20(oxygen storage capacity,24.13%)exhibited high hydrogen yield of~10.30 mmol g^(-1) and hydrogen production rate of~0.66 mmol g^(-1) min^(-1) which was twice as high as that of Fe_(2)O_(3)/Al_(2)O_(3).Further,the transient pulse test indicated that active oxygen diffusion was the ratelimiting step during the redox process.The electrochemical impedance spectroscopy(EIS)measurement revealed that the YSZ support addition facilitated oxygen diffusion of materials,which contributed to the improved hydrogen production performance.The support effect obtained in this work provides a potentially efficient route for the modification of oxygen carrier materials.展开更多
Chemical looping technology holds great potential on efficient CO2 splitting with much higher CO production and CO2 splitting rate than photocatalytic processes.Conventional oxygen carrier requires high temperature(ty...Chemical looping technology holds great potential on efficient CO2 splitting with much higher CO production and CO2 splitting rate than photocatalytic processes.Conventional oxygen carrier requires high temperature(typically 850–1000°C)to ensure sufficient redox activity,but the stable and high CO2 conversion is favored at a lower temperature,leading to the degrading on the reaction kinetics as well as the low CO production and CO2 splitting rate.In this paper,we prepared several ternary spinels and demonstrated their performance for chemical looping CO2 splitting at moderate temperatures.Using the promotion effect of Cu to cobalt ferrite reduction and reversible phase change of the reduced metals,Cu0.4 Co0.6 Fe2 O4 exhibits high CO2 splitting rate(144.6μmol g–1 min–1)and total CO production(9100μmol g–1)at 650°C.The high performance of this earth-abundant spinel material is also consistent in repeated redox cycles,enabling their potential in industrial use.展开更多
Operating chemical looping process at mid-temperatures(550–750℃)presents exciting potential for the stable production of hydrogen.However,the reactivity of oxygen carriers is compromised by the detrimental effect of...Operating chemical looping process at mid-temperatures(550–750℃)presents exciting potential for the stable production of hydrogen.However,the reactivity of oxygen carriers is compromised by the detrimental effect of the relatively low temperatures on the redox kinetics.Although the reactivity at mid-temperature can be improved by the addition of noble metals,the high cost of these noble metal containing materials significantly hindered their scalable applications.In the current work,we propose to incorporate earth-abundant metals into the ironbased spinel for hydrogen production in a chemical looping scheme at mid-temperatures.Mn0.2Co0.4Fe2.4O4 shows a high hydrogen production performance at the average rate of~0.62 mmol g^(-1) min^(-1) and a hydrogen yield of~9.29 mmol g^(-1) with satisfactory stability over 20 cycles at 550℃.The mechanism studies manifest that the enhanced hydrogen production performance is a result of the improved oxygen-ion conductivity to enhance reduction reaction and high reactivity of reduced samples with steam.The performance of the oxygen carriers in this work is comparable to those noble-metal containing materials,enabling their potential for industrial applications.展开更多
As industrialization accelerates and the amount of hazardous waste generated gradually increases,the means of disposal of hazardous waste is of increasing concern.In this paper,a 40 t/d counter-fow rotary kiln inciner...As industrialization accelerates and the amount of hazardous waste generated gradually increases,the means of disposal of hazardous waste is of increasing concern.In this paper,a 40 t/d counter-fow rotary kiln incineration system owned by a Jiangsu environmental protection company was researched.The software Aspen Plus was used to build the mixed pyrolysis model and the software Fluent was used to build the computational fuid dynamics model of the incineration system.The infuence of the calorifc value of the hazardous waste,the operating temperature and the air supply on the operational efectiveness of the incineration system were analyzed by varying the simulation conditions.The results show that the SO_(x)and NO_(x)content of the product is lower when the operating temperature is above 800℃.The incineration system could only operate above 800℃when the calorifc value of the hazardous waste is not less than 1500 kcal/kg.The incineration system operated best at a primary air velocity of 1.5 m/s.The simulation results in this paper serve as a guide for the operation of counter-fow rotary kiln incineration systems.展开更多
基金the financial support from the National Natural Science Foundation of China (52076045)the Ministry of Science and Technology of China (2019YFC1906700, 2018YFC1902600)the support from “Zhishan Scholar” of Southeast University。
文摘Developing efficient electrocatalysts for converting dinitrogen to ammonia through electrocatalysis is of significance to the decentralized ammonia production. Here, through high-throughput density functional theory calculations, we demonstrated that the interfacial modulation of hexagonal boron nitride/graphene(hBN-graphene) could sufficiently improve the catalytic activity of the single transition metal atom catalysts for nitrogen reduction reaction(NRR). It was revealed that Re@hBN-graphene and Os@hBN-graphene possessed remarkable NRR catalytic activity with low limiting potentials of 0.29 V and 0.33 V, respectively. Furthermore, the mechanism of the enhanced catalytic activity was investigated based on various descriptors of the adsorption energies of intermediates, where the synergistic effect of hBN and graphene in the hybrid substrate was found to play a key role. Motivated by the synergistic effect of hybrid substrate in single-atom catalysts, a novel strategy was proposed to efficiently design dual-atom catalysts by integrating the merits of both metal components. The as-designed dual-atom catalyst Fe-Mo@hBN exhibited more excellent NRR catalytic performance with a limiting potential of 0.17 V, manifesting the solidity of the design strategy. Our findings open new avenues for the search of heterostructure substrates for single-atom catalysts and the efficient design of dualatom catalysts for NRR.
基金partly supported by the New Energy and Industrial Technology Development Organization(NEDO)by the Japan Society for the Promotion of Science KAKENHI(21K14090)+3 种基金the National Key R&D Program of China(2019YFE0122000)the Scientific Research Foundation of Graduate School of Southeast University(YBPY2106)the China Scholarship Councilby the Advanced Research Infrastructure for Materials and Nanotechnology in Japan(ARIM Japan)sponsored by the Ministry of Education,Culture,Sport,Science and Technology(MEXT),Japan。
文摘In the present study,two Ni/YSZ anodes with different volume ratios of Ni and YSZ,30:70 and 45:55 vol%,are operated in dry methane under open circuit and polarized conditions.Three-dimensional(3D)Ni/YSZ microstructures after carbon deposition are reconstructed by the focused ion beam-scanning electron microscopy(FIB-SEM)with the help of machine learning segmentation.From the reconstructed mircostructures,volume fraction,connectivity,three phase boundary(TPB)density,and tortuosity are quantified.In addition,local carbon microstructures are quantitatively reconstructed,and the effect of polarization on carbon morphology is investigated.It is demonstrated that Ni surface in the vicinity of active TPB near the electrolyte is free from carbon formation,while remaining Ni surface at some distances from TPB exhibits severe carbon deposition.In average,total amount of carbon deposition is larger near the electrolyte.These observations imply complex interplay between the electrochemical steam generation and methane cracking on Ni surface which take place very locally near the active TPB.
基金supported by grants from the National Institute on Aging(AG063766and AG028740 to RX,AG066654 to SMH,T32AG062728 to TM)the American Cancer Society(RSG-17-171-01-DMC to RX)the American Federation for Aging Research(AGR DT07-2502019 and AGR DTD 09-15-2021 to SMH)。
文摘Mitochondria are well cha racterized by their fundamental functions in regulating cellular homeostasis,including energy and iron metabolism.These functions are essential in neurons with high metabolic demands and elongated neuronal processes.Mitochondria dynamically change morphology,localization,and activity to match neurons'spatial and temporal demands.Mitochondrial dysfunctions have been associated with many neurological disorders.
文摘BACKGROUND： Many methods have been attempted to repair nerves following spinal cord injury, including peripheral nerve transplantation, Schwann cell transplantation, olfactory ensheathing cell transplantation, and embryonic neural tissue transplantation. However, there is a need for improved outcomes. OBJECTIVE： To investigate the repair feasibility for rat spinal cord injury using human neural stem cells （hNSCs） genetically modified by lentivirus to express neurotrophin-3. DESIGN, TIME AND SETTING： In vitro cell biological experiment and in vivo randomized, controlled genetic engineering experiment were performed at the Third Military Medical University of Chinese PLA and First People＇s Hospital of Yibin, China from March 2006 to December 2007. MATERIALS： A total of 64 adult, female, Wistar rats were used for the in vivo study. Of them, 48 rats were used to establish models of spinal cord hemisection, and were subsequently equally and randomly assigned to model, genetically modified hNSC, and normal hNSC groups. The remaining 16 rats served as normal controls. METHODS： hNSCs were in vitro genetically modified by lentivirus to secrete both green fluorescence protein and neurotrophin-3. Neurotrophin-3 expression was measured by Western blot. Genetically modified hNSC or normal hNSC suspension （5 × 10^5） was injected into the rat spinal cord following T10 spinal cord hemisection. A total of 5μL Dulbecco＇s-modified Eagle＇s medium was infused into the rat spinal cord in the model grop. Transgene expression and survival of transplanted hNSCs were determined by immunohistochemistry. Motor function was evaluated using the Basso, Beattie, and Bresnahan （BBB） scale. MAIN OUTCOME MEASURES： The following parameters were measured： expression of neurotrophin-3 produced by genetically modified hNSCs, transgene expression and survival of hNSCs in rats, motor function in rats. RESULTS： hNSCs were successfully genetically modified by lentivirus to stably express neurotrophin-3. The transplanted hNSCs primarily gathered at, or around, the injection site two weeks following transplantation, and gradually migrated towards the surrounding tissue. Transplanted hNSCs were observed 7.0-8.0 mm away from the injection site. In addition, hNSCs were observed 10 weeks after transplantation. At week 4, BBB locomotor scores were significantly greater in the genetically modified hNSC and normal hNSC groups, compared with the model group （P 〈 0.05）, and scores were significantly greater in the genetically modified hNSC group compared with the normal hNSC group （P 〈 0.05）. CONCLUSION： hNSCs were genetically modified with lentivirus to stably secrete neurotrophin-3. hNSCs improved motor function recovery in rats following spinal cord injury.
基金supported by the National Hi-tech Research and Development Program of China(863 Program)(2012AA051801)the Fundamenta lResearch Funds for the Central Universities(No.CXZZ13 0112)
文摘A series of Cu-Mg-Al hydrotalcites derived oxides with a(Cu+Mg)/Al mole ratio of 3 and varied Cu/Mg mole ratio(from 0.07 to 0.30) were prepared by co-precipitation and calcination methods, then they were introduced to the hydrogenation of furfural in aqueous-phase. Effects of Cu/Mg mole ratio, reaction temperature, initial hydrogen pressure, reaction time and catalyst amount on the conversion rate of furfural as well as the selectivity toward desired product cyclopentanol were systematically investigated. The conversion of furfural over calcined hydrotalcite catalyst with a Cu/Mg mole ratio of 0.2 was up to 98.5% when the reaction was carried out under 140 ?C and the initial hydrogen pressure of 4 MPa for 10 h, while the selectivity toward cyclopentanol was up to 94.8%. The catalysts were characterized by XRD and SEM. XRD diffraction of all the samples showed characteristic pattern of hydrotalcite with varied peak intensity as a result of different Cu content. The catalytic activity was improved gradually with the increase of Cu component in the hydrotalcite.
基金This work was supported by the Scientific Research Projects of Universities in Inner Mongolia Autonomous Region(NJZY111)Natural Scientific Research Projects of Inner Mongolia Autonomous Region(2020MS03060)We thank Elsevier Ltd.,UK and FreeScience,China for their assistance in English editing of the manuscript.
文摘Depression is a prevalent mental disorder that is associated with aging and contributes to increased mortality and morbidity.The overall prevalence of geriatric depression with clinically significant symptoms is currently on the rise.Recent studies have demonstrated that altered expressions of long non-coding RNAs(lncRNAs)in the brain affect neurodevelopment and manifest modulating functions during the depression.However,most lncRNAs have not yet been studied.Herein,we analyzed the transcriptome of dysregulated lncRNAs to reveal their expressions in a mouse model exhibiting depressive-like behaviors,as well as their corresponding response following antidepressant fluoxetine treatment.A chronic unpredictable mild stress(CUMS)mouse model was applied.A sixweek fluoxetine intervention in CUMS-induced mice attenuated depressive-like behaviors.In addition,differential expression analysis of lncRNAs was performed following RNA-sequencing.A total of 282 lncRNAs(134 up-regulated and 148 down-regulated)were differentially expressed in CUMS-induced mice relative to non-stressed counterparts(P<0.05).Moreover,370 differentially expressed lncRNAs were identified in CUMS-induced mice after fluoxetine intervention.Gene Ontology(GO)analyses showed an association between significantly dysregulated lncRNAs and protein binding,oxygen binding,and transport activity,while the Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis indicated that these dysregulated lncRNAs might be involved in inflammatory response pathways.Fluoxetine effectively ameliorated the symptoms of depression in CUMS-induced mice by regulating the expression of lncRNAs in the hippocampus.The findings herein provide valuable insights into the potential mechanism underlying depression in elderly people.
基金This work was supported by grants from the National Natural Science Foundation of China(No.81971891,No.82172196,No.81772134 and No.81571939)Key Laboratory of Emergency and Trauma(Hainan Medical University)of Ministry of Education(No.KLET-202108)the College Students’Innovation and Entrepreneurship Project(No.S20210026020013).
文摘Ischemic stroke is a serious cerebrovascular disease with high morbidity and mortality.As a result of ischemia-reperfusion,a cascade of pathophysiological responses is triggered by the imbalance in metabolic supply and demand,resulting in cell loss.These cellular injuries follow various molecular mechanisms solely or in combination with this disorder.Mitochondria play a driving role in the pathophysiological processes of ischemic stroke.Once ischemic stroke occurs,damaged cells would respond to such stress through mitophagy.Mitophagy is known as a conservatively selective autophagy,contributing to the removal of excessive protein aggregates and damaged intracellular components,as well as aging mitochondria.Moderate mitophagy may exert neuroprotection against stroke.Several pathways associated with the mitochondrial network collectively contribute to recovering the homeostasis of the neurovascular unit.However,excessive mitophagy would also promote ischemia-reperfusion injury.Therefore,mitophagy is a double-edged sword,which suggests that maximizing the benefits of mitophagy is one of the direction of future efforts.This review emphasized the role of mitophagy in ischemic stroke,and highlighted the crosstalk between mitophagy and apoptosis/necroptosis.
基金This work was supported by the projects of China Geological Survey(DD20160223,DD20190102).
文摘Natural gas hydrate,oil and gas were all found together in the Qilian Mountain permafrost area,northeast of Qinghai-Tibet Plateau,China.They are closely associated with each other in space,but whether they are in any genetic relations are unknown yet.In this paper,a hydrocarbon gas-generation series,gas-fluid migration series and hydrocarbon gas-accumulation series are analyzed to probe the spatial,temporal and genetic relationships among natural natural gas hydrate,oil and gas.The subsequent results show that natural gas hydrate,oil and gas actually form a natural gas hydrate-oil-gas system.Based on the Middle Jurassic and the Upper Triassic hydrocarbon gas-generation series,it is divided into four major sub-systems in the study area:(1)A conventional Upper Triassic gas-bearing sub-system with peak hydrocarbon gas-generation in the late Middle Jurassic;(2)a conventional Middle Jurassic oil-bearing sub-system with low to mature hydrocarbon gas-generation in the late Middle Jurassic;(3)a natural gas hydrate sub-system with main gas source from the Upper Triassic gas-bearing sub-system and minor gas source from the Middle Jurassic oil-bearing sub-system as well as little gas source from the Middle Jurassic coal-bed gas and the microbial gas;(4)a shallower gas sub-system with microbial alteration of the main gas source from the Upper Triassic gas-bearing sub-system.This natural gas hydrate-oil-gas system and its sub-systems are not only theoretical but also practical,and thus they will play an important role in the further exploration of natural gas hydrate,oil and gas,even other energy resources in the study area.
基金support of the National Key R&D Program of China(Grant no.2018YFB1501402)the Natural Science Foundation of Jiangsu Province(Grant no.BK20190363)the Fundamental Research Funds for the Central Universities(Grant no.2242020R20009).
文摘Co-pyrolysis of lignin and waste plastics,for example polyethylene(PE),has been studied,but related reports are basically on condition optimizations.This study revealed a new perspective on PE-promoted lignin pyrolysis to phenolic monomers with mass transfer and radical explanation.Lignin and PE were first pyrolyzed individually to identify pyrolysis characteristics,pyrolytic products,as well as the suitable copyrolysis temperature.Then,co-pyrolysis of blended lignin/PE with various ratios was investigated.Yields of lignin products reached the maximum under lignin/PE ratio of 1:1,but blended approach always inhibited the production of lignin phenols.This resulted from the poor mass transfer and interactions between lignin and PE,in which PE pyrolysates could easily escape from the particle gaps.While in layered approach,PE pyrolysates had to pass through the lignin layer which contributed to the good interactions with lignin pyrolysis intermediates,thus the yields of lignin-derived products were significantly improved.Interactions between lignin and PE(or their pyrolysates)were mainly radical quenching reactions,and X-ray photoelectron spectrum(XPS)and electron paramagnetic resonance(EPR)of pyrolytic chars were conducted to verify these interactions controlled by mass transfer.The percentage of C]C(sp^(2))and concentration of organic stable radicals in layered lignin/PE char were both the lowest compared with those in blended lignin/PE and lignin char,indicating the stabilization of lignin-derived radicals by PE pyrolysates.Moreover,the spin concentration of radicals in the char from layered char/PE was lower than that in lignin char,which further affirmed the quenching of radicals by PE in the layered co-pyrolysis mode.
基金supported by the National Natural Science Foundation of China (51706094)。
文摘The effect of self-reactivation on the CO_(2) capture capacity of the spent calcium based sorbent was investigated in a dual-fixed bed reactor.The sampled sorbents from the dual-fixed bed reactor were sent for XRD,SEM and N_2 adsorption analysis to explain the self-reactivation mechanism.The results show that the CaO in the spent sorbent discharged from the calciner absorbs the vapor in the air to form Ca(OH)_(2) and further Ca(OH)_(2)·2 H_(2) O under environmental conditions,during which process the CO_(2) capture capacity of the spent sorbent can be self-reactivated.The microstructure of the spent sorbent is improved by the self-reactivation process,resulting in more porous microstructure,higher BET surface area and pore volume.Compared with the calcined spent sorbent that has experienced 20 cycles,the pore volume and BET surface area are increased by 6.69 times and 56.3% after self-reactivation when φ=170%.The improved microstructure makes it easier for the CO_(2) diffusion and carbonation reaction in the sorbent.Therefore,the CO_(2) capture capacity of the spent sorbent is enhanced by self-reactivation process.A self-reactivation process coupled with calcium looping process was proposed to reuse the discharged spent calcium based sorbent from the calciner.Higher average carbonation conversion and CO_(2) capture efficiency can be achieved when self-reactivated spent sorbent is used as supplementary sorbent in the calciner rather than fresh CaCO_(3) under the same conditions.
基金the National Natural Science Foundation of China(Grant No.51906041)the Natural Science Foundation of Jiangsu Province(Grant NO.BK20190360)the National Science Foundation for Distinguished Young Scholars of China(Grant No.51525601)。
文摘The chemical looping process,where an oxygen carrier is reduced and oxidized in a cyclic manner,offers a promising option for hydrogen production through splitting water because of the much higher water splitting efficiency than solar electrocatalytic and photocatalytic process.A typical oxygen carrier has to comprise a significant amount of inert support,to maintain stability in multiple redox cycles,thereby resulting in a trade-off between the reaction reactivity and stability.Herein,we proposed the use of ion-conductive yttria-stabilized zirconia(YSZ)support Fe_(2)O_(3)to prepare oxygen carriers materials.The obtained Fe_(2)O_(3)/YSZ composites showed high reactivity and stability.Particularly,Fe_(2)O_(3)/YSZ-20(oxygen storage capacity,24.13%)exhibited high hydrogen yield of~10.30 mmol g^(-1) and hydrogen production rate of~0.66 mmol g^(-1) min^(-1) which was twice as high as that of Fe_(2)O_(3)/Al_(2)O_(3).Further,the transient pulse test indicated that active oxygen diffusion was the ratelimiting step during the redox process.The electrochemical impedance spectroscopy(EIS)measurement revealed that the YSZ support addition facilitated oxygen diffusion of materials,which contributed to the improved hydrogen production performance.The support effect obtained in this work provides a potentially efficient route for the modification of oxygen carrier materials.
基金National Natural Science Foundation of China(Grant No.51706041)the National Natural Science Foundation of China(NSFC)Projects(Grant No.51661145011)the National Science Foundation for Distinguished Young Scholars of China(Grant No.51525601)。
文摘Chemical looping technology holds great potential on efficient CO2 splitting with much higher CO production and CO2 splitting rate than photocatalytic processes.Conventional oxygen carrier requires high temperature(typically 850–1000°C)to ensure sufficient redox activity,but the stable and high CO2 conversion is favored at a lower temperature,leading to the degrading on the reaction kinetics as well as the low CO production and CO2 splitting rate.In this paper,we prepared several ternary spinels and demonstrated their performance for chemical looping CO2 splitting at moderate temperatures.Using the promotion effect of Cu to cobalt ferrite reduction and reversible phase change of the reduced metals,Cu0.4 Co0.6 Fe2 O4 exhibits high CO2 splitting rate(144.6μmol g–1 min–1)and total CO production(9100μmol g–1)at 650°C.The high performance of this earth-abundant spinel material is also consistent in repeated redox cycles,enabling their potential in industrial use.
基金The authors gratefully acknowledge the National Natural Science Foundation of China(Grant No.51906041)the Natural Science Foundation of Jiangsu Province(Grant NO.BK20190360)the National Science Foundation for Distinguished Young Scholars of China(Grant No.51525601).
文摘Operating chemical looping process at mid-temperatures(550–750℃)presents exciting potential for the stable production of hydrogen.However,the reactivity of oxygen carriers is compromised by the detrimental effect of the relatively low temperatures on the redox kinetics.Although the reactivity at mid-temperature can be improved by the addition of noble metals,the high cost of these noble metal containing materials significantly hindered their scalable applications.In the current work,we propose to incorporate earth-abundant metals into the ironbased spinel for hydrogen production in a chemical looping scheme at mid-temperatures.Mn0.2Co0.4Fe2.4O4 shows a high hydrogen production performance at the average rate of~0.62 mmol g^(-1) min^(-1) and a hydrogen yield of~9.29 mmol g^(-1) with satisfactory stability over 20 cycles at 550℃.The mechanism studies manifest that the enhanced hydrogen production performance is a result of the improved oxygen-ion conductivity to enhance reduction reaction and high reactivity of reduced samples with steam.The performance of the oxygen carriers in this work is comparable to those noble-metal containing materials,enabling their potential for industrial applications.
基金supported by the National Key R&D Program of China(No.2018YFC1902600)。
文摘As industrialization accelerates and the amount of hazardous waste generated gradually increases,the means of disposal of hazardous waste is of increasing concern.In this paper,a 40 t/d counter-fow rotary kiln incineration system owned by a Jiangsu environmental protection company was researched.The software Aspen Plus was used to build the mixed pyrolysis model and the software Fluent was used to build the computational fuid dynamics model of the incineration system.The infuence of the calorifc value of the hazardous waste,the operating temperature and the air supply on the operational efectiveness of the incineration system were analyzed by varying the simulation conditions.The results show that the SO_(x)and NO_(x)content of the product is lower when the operating temperature is above 800℃.The incineration system could only operate above 800℃when the calorifc value of the hazardous waste is not less than 1500 kcal/kg.The incineration system operated best at a primary air velocity of 1.5 m/s.The simulation results in this paper serve as a guide for the operation of counter-fow rotary kiln incineration systems.
