The photocatalytic reduction of carbon dioxide(CO2)into high-value C2+hydrocarbons represents a sustainable pathway to alleviate energy shortages and reduce atmospheric CO2levels.In this study,a unique tandem...The photocatalytic reduction of carbon dioxide(CO2)into high-value C2+hydrocarbons represents a sustainable pathway to alleviate energy shortages and reduce atmospheric CO2levels.In this study,a unique tandem photocatalyst(CoTi-CN)is constructed by integrating bimetallic CoTi-MOF with metal-free half-metallic C(CN)3.This composite demonstrates markedly enhanced activity and selectivity in the photocatalytic CO2reduction to ethylene(C2H4),achieving a C2H4selectivity of 36.8%and a generation yield of 31.3μmol g-1over 5 h.Density functional theory(DFT)calculations combined with in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)analysis reveal that C(CN)3acts as an efficient CO2to CO converter,while CoTi-MOF favors the adsorption and C-C coupling of*CO intermediates.The spatially decoupled CO generation and C-C coupling processes lead to optimized intermediate coverage and reduced energy barriers,resulting in superior selectivity toward multi-carbon products.This work opens new horizons for the design of tandem photocatalysts that combine half-metallic catalysts with bimetallic MOFs,achieving a significant enhancement in the activity and selectivity of photocatalytic C2H4production.展开更多
Activation of spinal cord neural stem cells(NSCs)and subsequent neurogenesis holds a promising alternative for spinal cord injury(SCI)repair.Our previous study demonstrated that complement C3a,derived from reactive as...Activation of spinal cord neural stem cells(NSCs)and subsequent neurogenesis holds a promising alternative for spinal cord injury(SCI)repair.Our previous study demonstrated that complement C3a,derived from reactive astrocytes,inhibits NSC proliferation by suppressing protein aggregate clearance through the deubiquitinating enzyme ubiquitin carboxy-terminal hydrolase L1(UCHL1)-proteasome system post-SCI.However,the potential molecular mechanism by which C3a modulates NSC activation via this pathway remains unclear.Here,we revealed that C3a/C3a receptor(C3aR)signaling activated NF-κB p65,which in turn inhibited Nrf2 activity and UCHL1 expression,resulting in diminished proteasome activity and the accumulation of protein aggregates,and ultimately impaired NSC activation.Both knockdown of NF-κB p65 and Nrf2 upregulation restored UCHL1 expression and proteasome activity in vitro,promoting NSC activation by enhancing protein aggregate clearance.Mechanistically,we found that NF-κB p65 regulated Nrf2 activity through a dual mechanism:(1)promoting Keap1-dependent ubiquitination and proteasome degradation of Nrf2;(2)inhibiting protein kinase C-mediated Nrf2 phosphorylation and nuclear translocation.Using the dual-luciferase reporter assay and chromatin immunoprecipitation(ChIP)analysis,we further identified UCHL1 as a direct transcriptional target of Nrf2.Importantly,in vivo experiments using SCI mice confirmed that either C3aR blockade,NF-κB p65 knockdown,or Nrf2 overexpression could rescue SCI-induced UCHL1 downregulation.Together,this study uncovers the C3a-NF-κB p65-Nrf2-UCHL1-proteasome axis as a critical regulator of NSC activation after SCI.This may provide novel molecular targets and intervention strategies for SCI repair.展开更多
目的:通过对C3H10T1/2细胞分化为成熟棕色脂肪细胞的培养、诱导分化及鉴定,深入探讨棕色脂肪细胞的生物学特性,为人类棕色脂肪细胞的相关研究提供实验参考与理论依据。方法:C3H10T1/2细胞经细胞接种、培养及诱导分化处理,利用光学显微...目的:通过对C3H10T1/2细胞分化为成熟棕色脂肪细胞的培养、诱导分化及鉴定,深入探讨棕色脂肪细胞的生物学特性,为人类棕色脂肪细胞的相关研究提供实验参考与理论依据。方法:C3H10T1/2细胞经细胞接种、培养及诱导分化处理,利用光学显微镜观察细胞形态变化,并通过油红O染色、免疫荧光法、线粒体探针法以及线粒体电镜技术对分化细胞进行鉴定分析。结果:未分化的C3H10T1/2细胞形态多样,具有突触伸展特征;分化后的细胞逐渐变为圆形或椭圆形,形成环形脂滴;未分化组细胞形态无明显变化。油红O染色显示,未分化组细胞基本无染色,而分化组中约90%的细胞红染,脂滴分布于细胞核周围,吸光度值显著升高(P<0.05)。分化组解偶联蛋白1(uncoupling protein 1,UCP1)、过氧化物酶体增殖激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)辅激活因子1α(PPARγco-activator-1α,PGC-1α)、PPARγ和转录因子PRDM16的相对荧光强度和蛋白表达量显著高于未分化组(P<0.05),且线粒体活性增强。结论:本研究成功诱导C3H10T1/2细胞分化为成熟棕色脂肪细胞,结合细胞形态观察、关键蛋白表达检测及线粒体功能分析进行综合评估,证实了细胞的有效分化及成熟棕色脂肪细胞的功能特性。展开更多
Li3V2(PO4)3 is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li3V_...Li3V2(PO4)3 is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li3V2(PO4)3(LVP@C)nanoparticles on carbon nanofibers(CNFs)has been achieved by an electrospinning technique followed by calcination.The protective carbon coating prevents the aggregation of the LVP nanoparticles and suppresses V dissolution by preventing direct contact with aqueous electrolytes.The CNFs derived from the electrospun nanofibers provide a 3D network to increase the electronic conductivity of the LVP electrode,and the LVP@C-CNF hybrid film can be directly used as a freestanding cathode for zinc-ion batteries without adding conductive additives and binders.A mechanism for the formation of a uniform and continuous carbon coating has been proposed.This nanostructure,combined with the uniform and intact carbon coverage,significantly increases the electronic conductivity.This LVP@C-CNF freestanding electrode has an excellent rate capability(47.3%retention at 2 C)and cycling stability(61.2%retention after 100 cycles)within the voltage range 0.6 V to 1.95 V and is highly suitable for zinc-ion battery applications.展开更多
The selective cleavage of Cα-Cβbonds is of great significance to lignin valorization,and photocataly-sis offers an eco-friendly pathway to achieve this process.Here,graphitic carbon nitride(g-C3N4)modifi...The selective cleavage of Cα-Cβbonds is of great significance to lignin valorization,and photocataly-sis offers an eco-friendly pathway to achieve this process.Here,graphitic carbon nitride(g-C3N4)modified with hollow tubular In2O3was constructed via the calcination method for the photocatalytic cleavage of lignin Cα-Cβbonds.MIL-68(In)was used as the precursor of In2O3,imparting a unique hollow tubular structure and a relatively large specific surface area.The hollow tubular structure is helpful for light penetration and scattering,as well as rapid migration of the lignin substrate.The Z-scheme g-C3N4/In2O3heterojunction exhibited 92.1% conversion(corresponding benzaldehyde yield:82.4%)of the lignin model compound 2-phenoxy-1-phenylethanol(PP-ol),outperforming pure In2O3and g-C3N4by 40-and 2.3-fold,respectively,under 395 nm light illumination.By varying the illumination wavelength,the conversion and yields of the g-C3N4/In2O3composites were found to follow wavelength-dependent reactivities.Additionally,photogenerated holes are capable of converting PP-ol into benzoic acid,whereas1O2mainly converts PP-ol into benzaldehyde.This work could encourage the application of metal-organic frameworks in biomass conversion and provide insight into photocatalytic lignin valorization.展开更多
基金supported by the National Natural Science Foundation of China(51303083)the National Natural Science Foundation of China for Excellent Young Scholars(51922050)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20191293)the Fundamental Research Funds for the Central Universities(30920021123).
摘要The photocatalytic reduction of carbon dioxide(CO2)into high-value C2+hydrocarbons represents a sustainable pathway to alleviate energy shortages and reduce atmospheric CO2levels.In this study,a unique tandem photocatalyst(CoTi-CN)is constructed by integrating bimetallic CoTi-MOF with metal-free half-metallic C(CN)3.This composite demonstrates markedly enhanced activity and selectivity in the photocatalytic CO2reduction to ethylene(C2H4),achieving a C2H4selectivity of 36.8%and a generation yield of 31.3μmol g-1over 5 h.Density functional theory(DFT)calculations combined with in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)analysis reveal that C(CN)3acts as an efficient CO2to CO converter,while CoTi-MOF favors the adsorption and C-C coupling of*CO intermediates.The spatially decoupled CO generation and C-C coupling processes lead to optimized intermediate coverage and reduced energy barriers,resulting in superior selectivity toward multi-carbon products.This work opens new horizons for the design of tandem photocatalysts that combine half-metallic catalysts with bimetallic MOFs,achieving a significant enhancement in the activity and selectivity of photocatalytic C2H4production.
基金supported by the National Natural Science Foundation of China(82071362 and 82270669)Key Project of the Regional Joint Fund of Guangdong Province(2023B1515120077)+3 种基金Basic Research Program of Shenzhen Science and Technology Innovation Commission(JCYJ20210324123001003 and JCYJ20220530144801003)Shenzhen Key Laboratory of Bone Tissue Repair and Translational Research(ZDSYS20230626091402006)the Innovation and Entrepreneurship Training Program for College Students,Sun Yat-sen University(20242150)the Leading Innovation and Entrepreneurship Team Program of Zhejiang Province,China(2023R01005).
摘要Activation of spinal cord neural stem cells(NSCs)and subsequent neurogenesis holds a promising alternative for spinal cord injury(SCI)repair.Our previous study demonstrated that complement C3a,derived from reactive astrocytes,inhibits NSC proliferation by suppressing protein aggregate clearance through the deubiquitinating enzyme ubiquitin carboxy-terminal hydrolase L1(UCHL1)-proteasome system post-SCI.However,the potential molecular mechanism by which C3a modulates NSC activation via this pathway remains unclear.Here,we revealed that C3a/C3a receptor(C3aR)signaling activated NF-κB p65,which in turn inhibited Nrf2 activity and UCHL1 expression,resulting in diminished proteasome activity and the accumulation of protein aggregates,and ultimately impaired NSC activation.Both knockdown of NF-κB p65 and Nrf2 upregulation restored UCHL1 expression and proteasome activity in vitro,promoting NSC activation by enhancing protein aggregate clearance.Mechanistically,we found that NF-κB p65 regulated Nrf2 activity through a dual mechanism:(1)promoting Keap1-dependent ubiquitination and proteasome degradation of Nrf2;(2)inhibiting protein kinase C-mediated Nrf2 phosphorylation and nuclear translocation.Using the dual-luciferase reporter assay and chromatin immunoprecipitation(ChIP)analysis,we further identified UCHL1 as a direct transcriptional target of Nrf2.Importantly,in vivo experiments using SCI mice confirmed that either C3aR blockade,NF-κB p65 knockdown,or Nrf2 overexpression could rescue SCI-induced UCHL1 downregulation.Together,this study uncovers the C3a-NF-κB p65-Nrf2-UCHL1-proteasome axis as a critical regulator of NSC activation after SCI.This may provide novel molecular targets and intervention strategies for SCI repair.
摘要目的:通过对C3H10T1/2细胞分化为成熟棕色脂肪细胞的培养、诱导分化及鉴定,深入探讨棕色脂肪细胞的生物学特性,为人类棕色脂肪细胞的相关研究提供实验参考与理论依据。方法:C3H10T1/2细胞经细胞接种、培养及诱导分化处理,利用光学显微镜观察细胞形态变化,并通过油红O染色、免疫荧光法、线粒体探针法以及线粒体电镜技术对分化细胞进行鉴定分析。结果:未分化的C3H10T1/2细胞形态多样,具有突触伸展特征;分化后的细胞逐渐变为圆形或椭圆形,形成环形脂滴;未分化组细胞形态无明显变化。油红O染色显示,未分化组细胞基本无染色,而分化组中约90%的细胞红染,脂滴分布于细胞核周围,吸光度值显著升高(P<0.05)。分化组解偶联蛋白1(uncoupling protein 1,UCP1)、过氧化物酶体增殖激活受体γ(peroxisome proliferator-activated receptorγ,PPARγ)辅激活因子1α(PPARγco-activator-1α,PGC-1α)、PPARγ和转录因子PRDM16的相对荧光强度和蛋白表达量显著高于未分化组(P<0.05),且线粒体活性增强。结论:本研究成功诱导C3H10T1/2细胞分化为成熟棕色脂肪细胞,结合细胞形态观察、关键蛋白表达检测及线粒体功能分析进行综合评估,证实了细胞的有效分化及成熟棕色脂肪细胞的功能特性。
摘要Li3V2(PO4)3 is a promising high-voltage cathode for zincion batteries,but it suffers from a poor electronic conductivity and vanadium dissolution in aqueous electrolytes.The growth of carboncoated Li3V2(PO4)3(LVP@C)nanoparticles on carbon nanofibers(CNFs)has been achieved by an electrospinning technique followed by calcination.The protective carbon coating prevents the aggregation of the LVP nanoparticles and suppresses V dissolution by preventing direct contact with aqueous electrolytes.The CNFs derived from the electrospun nanofibers provide a 3D network to increase the electronic conductivity of the LVP electrode,and the LVP@C-CNF hybrid film can be directly used as a freestanding cathode for zinc-ion batteries without adding conductive additives and binders.A mechanism for the formation of a uniform and continuous carbon coating has been proposed.This nanostructure,combined with the uniform and intact carbon coverage,significantly increases the electronic conductivity.This LVP@C-CNF freestanding electrode has an excellent rate capability(47.3%retention at 2 C)and cycling stability(61.2%retention after 100 cycles)within the voltage range 0.6 V to 1.95 V and is highly suitable for zinc-ion battery applications.
摘要The selective cleavage of Cα-Cβbonds is of great significance to lignin valorization,and photocataly-sis offers an eco-friendly pathway to achieve this process.Here,graphitic carbon nitride(g-C3N4)modified with hollow tubular In2O3was constructed via the calcination method for the photocatalytic cleavage of lignin Cα-Cβbonds.MIL-68(In)was used as the precursor of In2O3,imparting a unique hollow tubular structure and a relatively large specific surface area.The hollow tubular structure is helpful for light penetration and scattering,as well as rapid migration of the lignin substrate.The Z-scheme g-C3N4/In2O3heterojunction exhibited 92.1% conversion(corresponding benzaldehyde yield:82.4%)of the lignin model compound 2-phenoxy-1-phenylethanol(PP-ol),outperforming pure In2O3and g-C3N4by 40-and 2.3-fold,respectively,under 395 nm light illumination.By varying the illumination wavelength,the conversion and yields of the g-C3N4/In2O3composites were found to follow wavelength-dependent reactivities.Additionally,photogenerated holes are capable of converting PP-ol into benzoic acid,whereas1O2mainly converts PP-ol into benzaldehyde.This work could encourage the application of metal-organic frameworks in biomass conversion and provide insight into photocatalytic lignin valorization.