Ischaemic stroke can induce rapid activation of microglia.As the resident immune cells of the central nervous system,microglial activation is believed to play a central role in neuroinflammation and pathological progr...Ischaemic stroke can induce rapid activation of microglia.As the resident immune cells of the central nervous system,microglial activation is believed to play a central role in neuroinflammation and pathological progression of ischaemic tissue.The activation of microglia after ischaemia involves several stereotypical events including morphological transformation,proliferation and polarisation.Studies using confocal or two-photon imaging techniques have revealed that the degree of microglial activation is correlated with the degree of ischaemia.Activated microglia display diverse polarisation phenotypes.It remains largely unclear regarding whether activated microglia are beneficial or detrimental to poststroke recovery.This mini-review focuses on the morphological and functional aspects of microglial activation,with particular attention to progress in two-photon imaging studies.展开更多
Oxidation of organic pollutants by sulfate radicals produced via activation of persulfate has emerged as a promising advanced oxidation technology to address various challenging environmental issues. The development o...Oxidation of organic pollutants by sulfate radicals produced via activation of persulfate has emerged as a promising advanced oxidation technology to address various challenging environmental issues. The development of an effective, environmentally-friendly, metal-free catalyst is the key to this technology. Additionally, a supported catalyst design is more advantageous than conventional suspended powder catalysts from the point of view of mass transfer and practical engineering applications （e.g. post-use separation）. In this study, a metal-free N-doped reduced graphene oxide （N-rGO） catalyst was prepared via a facile hydrothermal method. N-rGO filters were then synthesized by facile vacuum filtration, such that water can flow through nanochannels within the filters. Various advanced characterization techniques were employed to obtain structural and compositional information of the as-synthesized N-rGO filters. An optimized phenol oxidative flux of 0.036 ＋_ 0.002 mmol.h ~ was obtained by metal-flee catalytic activation of persulfate at an influent persulfate concentration of 1.0 mmol-L 1 and filter weight of 15 rag, while a N-free rGO filter demonstrated negligible phenol oxidation capability under similar conditions. Compared to a conventional batch system, the flow-through design demonstrates obviously enhanced oxidation kinetics （0.036 vs. 0.010 retool-h-I）, mainly due to the liquid flow through the filter leading to convection-enhanced transfer of the target molecule to the filter active sites. Overall, the results exemplified the advantages of organic compound removal by catalytic activation of persulfate using a metal-free catalyst in flow- through mode, and demonstrated the potential of N-rGO filters for practical environmental applications.展开更多
CRISPR-Cas9,-Cas12a,-Cas12b,and-Cas13 have been harnessed for genome engineering in human and plant cells(Liu et al.,2022).However,the large size of these Cas proteins(e.g.190 kDa for SpCas9)makes them difficult to de...CRISPR-Cas9,-Cas12a,-Cas12b,and-Cas13 have been harnessed for genome engineering in human and plant cells(Liu et al.,2022).However,the large size of these Cas proteins(e.g.190 kDa for SpCas9)makes them difficult to deliver into cells via a viral vector.The development of smaller Cas proteins will lead to reduced viral vector sizes that can be more widely adopted in versatile genome engineering systems.Recently,a CRISPR-Cas12j2(CasF)system was discovered in huge phages and developed into a hypercompact genome editor due to the small size of Cas12j2(80 kDa)(Pausch et al.,2020).Unfortunately,the gene editing efficiency of Cas12j2 in Arabidopsis protoplasts using ribonucleoprotein delivery was less than one percent(Pausch et al.,2020).Further optimization of this system is clearly required if CRISPR-Cas12j2-mediated editing in plant genomes is to be adopted by the plant sciences community.展开更多
Naturally occurring hematite has been widely studied in the Fenton-like system for water pollutant remediation due to its abundance and non-toxicity.However,its inadequate catalytic activity results in difficulty in e...Naturally occurring hematite has been widely studied in the Fenton-like system for water pollutant remediation due to its abundance and non-toxicity.However,its inadequate catalytic activity results in difficulty in effectively degrading pollutants in the catalytic degradation system that it constitutes.Thus,we constructed a photochemical system composed of hematite with{001}facet of high activity facet and low-cost and non-toxic oxalic acid(OA)for the removal of various types of pollutants.The removal rate for the degradation of metronidazole,tetracycline hydrochloride,Rhodamine B,and hexavalent chromium by hematite nanoplate with the exposed{001}facet activating OA under visible light irradiation was 4.75,2.25,2.33,and 2.74 times than that by the exposed{110}facet,respectively.Density functional theory(DFT)calculation proved that the OA molecule was more easily adsorbed on the{001}facet of hematite than that on the{110}facet,which would favor the formation of the more Fe(Ⅲ)-OA complex and reactive species.In addition,the reactive site of metronidazole for the attraction of radicals was identified on the basis of the DFT calculation on the molecular occupied orbitals,and the possible degradation pathway for metronidazole included carbon chain fracture,hydroxyethyl-cleavage,denitrogenation,and hydroxylation.Thus,this finding may offer a valuable direction in designing an efficient iron-based catalyst based on facet engineering for the improved activity of Fenton-like systems such as OA activation.展开更多
Kinetics study of gaseous hydrocarbons generated from vitrinites based on pyrolysis of gold tube closed system shows that the activation energies of methane generated from telocollinite are higher than that from desmo...Kinetics study of gaseous hydrocarbons generated from vitrinites based on pyrolysis of gold tube closed system shows that the activation energies of methane generated from telocollinite are higher than that from desmocol-linite due to structure differences. But carbon isotope ratios of generated methane in pyrolysates of vitrinites at the same temperature points are similar. Carbon isotope ratio of methane may decrease in the early stage of gas generation and then increase in the later stage. But at higher temperature, δ13C1 decreases slightly or almost keeps stable with increasing temperature. Since it is known that carbon isotope distillation is controlled by time, temperature and carbon isotope ratio of bulk organic matter, the character of side chains connected to macromolecule of vitrinite and distribution of activation energies have no obvious effect on carbon isotope fraction. Decreasing trend of δ13C1 in the early stage may be caused by contagious structure of vitrinite or differences of展开更多
基金This work was supported by grants from the National Natural Science Foundation of China(Nos.31471045 and 81771324).
文摘Ischaemic stroke can induce rapid activation of microglia.As the resident immune cells of the central nervous system,microglial activation is believed to play a central role in neuroinflammation and pathological progression of ischaemic tissue.The activation of microglia after ischaemia involves several stereotypical events including morphological transformation,proliferation and polarisation.Studies using confocal or two-photon imaging techniques have revealed that the degree of microglial activation is correlated with the degree of ischaemia.Activated microglia display diverse polarisation phenotypes.It remains largely unclear regarding whether activated microglia are beneficial or detrimental to poststroke recovery.This mini-review focuses on the morphological and functional aspects of microglial activation,with particular attention to progress in two-photon imaging studies.
文摘Oxidation of organic pollutants by sulfate radicals produced via activation of persulfate has emerged as a promising advanced oxidation technology to address various challenging environmental issues. The development of an effective, environmentally-friendly, metal-free catalyst is the key to this technology. Additionally, a supported catalyst design is more advantageous than conventional suspended powder catalysts from the point of view of mass transfer and practical engineering applications （e.g. post-use separation）. In this study, a metal-free N-doped reduced graphene oxide （N-rGO） catalyst was prepared via a facile hydrothermal method. N-rGO filters were then synthesized by facile vacuum filtration, such that water can flow through nanochannels within the filters. Various advanced characterization techniques were employed to obtain structural and compositional information of the as-synthesized N-rGO filters. An optimized phenol oxidative flux of 0.036 ＋_ 0.002 mmol.h ~ was obtained by metal-flee catalytic activation of persulfate at an influent persulfate concentration of 1.0 mmol-L 1 and filter weight of 15 rag, while a N-free rGO filter demonstrated negligible phenol oxidation capability under similar conditions. Compared to a conventional batch system, the flow-through design demonstrates obviously enhanced oxidation kinetics （0.036 vs. 0.010 retool-h-I）, mainly due to the liquid flow through the filter leading to convection-enhanced transfer of the target molecule to the filter active sites. Overall, the results exemplified the advantages of organic compound removal by catalytic activation of persulfate using a metal-free catalyst in flow- through mode, and demonstrated the potential of N-rGO filters for practical environmental applications.
基金supported by the National Key Research and Development Program of China(award no.NK2022010204)to Y.Z.the National Natural Science Foundation of China(award nos.32270433,32101205,32072045,and 31960423)to X.T.,X.Z.,and Y.Z.+3 种基金the Sichuan Science and Technology Program(award no.2021JDRC0032)to Y.Z.the Technology Innovation and Application Development Program of Chongqing(award no.CSTC2021JSCX-CYLHX0001)to X.T.and Y.Z.supported by the National Science Foundation Plant Genome Research Program grant(award nos.IOS-1758745 and IOS2029889)USDA-AFRI Agricultural Innovations Through Gene Editing Program(award no.2021-67013-34554)to Y.Q.S.S.is a fellow of the Foundation for Food and Agriculture Research.
文摘CRISPR-Cas9,-Cas12a,-Cas12b,and-Cas13 have been harnessed for genome engineering in human and plant cells(Liu et al.,2022).However,the large size of these Cas proteins(e.g.190 kDa for SpCas9)makes them difficult to deliver into cells via a viral vector.The development of smaller Cas proteins will lead to reduced viral vector sizes that can be more widely adopted in versatile genome engineering systems.Recently,a CRISPR-Cas12j2(CasF)system was discovered in huge phages and developed into a hypercompact genome editor due to the small size of Cas12j2(80 kDa)(Pausch et al.,2020).Unfortunately,the gene editing efficiency of Cas12j2 in Arabidopsis protoplasts using ribonucleoprotein delivery was less than one percent(Pausch et al.,2020).Further optimization of this system is clearly required if CRISPR-Cas12j2-mediated editing in plant genomes is to be adopted by the plant sciences community.
基金supported by the National Natural Science Foundation of China(No.22176151)。
文摘Naturally occurring hematite has been widely studied in the Fenton-like system for water pollutant remediation due to its abundance and non-toxicity.However,its inadequate catalytic activity results in difficulty in effectively degrading pollutants in the catalytic degradation system that it constitutes.Thus,we constructed a photochemical system composed of hematite with{001}facet of high activity facet and low-cost and non-toxic oxalic acid(OA)for the removal of various types of pollutants.The removal rate for the degradation of metronidazole,tetracycline hydrochloride,Rhodamine B,and hexavalent chromium by hematite nanoplate with the exposed{001}facet activating OA under visible light irradiation was 4.75,2.25,2.33,and 2.74 times than that by the exposed{110}facet,respectively.Density functional theory(DFT)calculation proved that the OA molecule was more easily adsorbed on the{001}facet of hematite than that on the{110}facet,which would favor the formation of the more Fe(Ⅲ)-OA complex and reactive species.In addition,the reactive site of metronidazole for the attraction of radicals was identified on the basis of the DFT calculation on the molecular occupied orbitals,and the possible degradation pathway for metronidazole included carbon chain fracture,hydroxyethyl-cleavage,denitrogenation,and hydroxylation.Thus,this finding may offer a valuable direction in designing an efficient iron-based catalyst based on facet engineering for the improved activity of Fenton-like systems such as OA activation.
文摘Kinetics study of gaseous hydrocarbons generated from vitrinites based on pyrolysis of gold tube closed system shows that the activation energies of methane generated from telocollinite are higher than that from desmocol-linite due to structure differences. But carbon isotope ratios of generated methane in pyrolysates of vitrinites at the same temperature points are similar. Carbon isotope ratio of methane may decrease in the early stage of gas generation and then increase in the later stage. But at higher temperature, δ13C1 decreases slightly or almost keeps stable with increasing temperature. Since it is known that carbon isotope distillation is controlled by time, temperature and carbon isotope ratio of bulk organic matter, the character of side chains connected to macromolecule of vitrinite and distribution of activation energies have no obvious effect on carbon isotope fraction. Decreasing trend of δ13C1 in the early stage may be caused by contagious structure of vitrinite or differences of
