The responses of activities, abundances and community structures of soil denitrifiers to mercury （Hg） stress were investigated through a short-term incubation experiment. Four soil treatments with different concentr...The responses of activities, abundances and community structures of soil denitrifiers to mercury （Hg） stress were investigated through a short-term incubation experiment. Four soil treatments with different concentrations of Hg （CK, Hg25, Hg50, and Hg100, denoted as 0, 25, 50, and 100 mg Hg/kg dry soil, respectively） were incubated for 28 days. Soil denitrification enzyme activity （DEA） was measured at day 3, 7 and 28. The abundances and community structures of two denitrification concerning genes, nirS （cd1-nitrite reductase gene） and nosZ （nitrous oxide reductase gene）, were analyzed using real-time PCR and denaturing gradient gel electrophoresis （DGGE）. Results showed that soil DEA was significantly stimulated in the treatments of Hg25 and Hg50 compared with others at day 7. Meanwhile, no difference in the abundances of soil nirS and nosZ was found between Hg spiked treatments and CK, except the lower abundance of nirS （P 〈 0.05） in the Hg added treatments compared with that in the CK at day 28. The community structures of denitrifiers based on nirS gene presented obvious change at day 7 along with the Hg additions, however, no variation was found in all treatments based on the nosZ gene. The results indicated that Hg （Hg25 and Hg50） had a strongly short-term stimulation on soil DEA, and nirS gene is more sensitive than nosZ gene to Hg stress.展开更多
In this study, series of novel composite phase change materials(PCMs) were prepared through vacuum impregnation by using meso-porous carbon as a supporting matrix and n-octadcane as PCMs.The meso-porous carbon materia...In this study, series of novel composite phase change materials(PCMs) were prepared through vacuum impregnation by using meso-porous carbon as a supporting matrix and n-octadcane as PCMs.The meso-porous carbon material was prepared through one-pot co-assembly method, using resorcinol and formaldehyde as carbon precursor, tetraethoxysilane as silica sources and triblock copolymer F127 as a template. And the phase behaviors of n-octadcane confined in the nano-porous structure of the meso-porous carbon were further investigated. Fourier transform-infrared spectroscopy spectra show that n-octadecane was effectively encapsulated in the porous structure of mesoporous carbon and the composite PCMs were successfully prepared. Differential scanning calorimetry results confirm that the composite PCMs possess a good phase change behavior, fast thermal-response rate and excellent thermal cycling stability. In addition, the composite PCMs possess expected heat storage and heat release properties. All these results demonstrate that the composite PCMs possess good comprehensive property so that they can be used widely in energy storage systems.展开更多
The transformation of mercury(Hg) in the environment plays a vital role in the cycling of Hg and its risk to the ecosystem and human health. Of particular importance are Hg oxidation/reduction and methylation/demethyl...The transformation of mercury(Hg) in the environment plays a vital role in the cycling of Hg and its risk to the ecosystem and human health. Of particular importance are Hg oxidation/reduction and methylation/demethylation processes driven or mediated by the dynamics of light, microorganisms, and organic carbon, among others. Advances in understanding those Hg transformation processes determine our capacity of projecting and mitigating Hg risk. Here, we provide a critical analysis of major knowledge gaps in our understanding of Hg transformation in nature, with perspectives on approaches moving forward. Our analysis focuses on Hg transformation processes in the environment, as well as emerging methodology in exploring these processes. Future avenues for improving the understanding of Hg transformation processes to protect ecosystem and human health are also explored.展开更多
Hausmannite is a common low valence Mn oxide mineral,with a distorted spinel structure,in surficial sediments.Although natural Mn oxides often contain various impurities of transitional metals(TMs),few studies have ad...Hausmannite is a common low valence Mn oxide mineral,with a distorted spinel structure,in surficial sediments.Although natural Mn oxides often contain various impurities of transitional metals(TMs),few studies have addressed the effect and related mechanism of TM doping on the reactivity of hausmannite with metal pollutants.Here,the reactivity of cobalt(Co)doped hausmannite with aqueous As(Ⅲ)and As(Ⅴ)was studied.Co doping decreased the point of zero charge of hausmannite and its adsorption capacity for As(Ⅴ).Despite a reduction of the initial As(Ⅲ)oxidation rate,Co-doped hausmannite could effectively oxidize As(Ⅲ)to As(Ⅴ),followed by the adsorption and fixation of a large amount of As(Ⅴ)on the mineral surface.Arsenic K-edge EXAFS analysis of the samples after As(Ⅴ)adsorption and As(Ⅲ)oxidation revealed that only As(Ⅴ)was adsorbed on the mineral surface,with an average As-Mn distance of 3.25–3.30 A,indicating the formation of bidentate binuclear complexes.These results provide new insights into the interaction mechanism between TMs and low valence Mn oxides and their effect on the geochemical behaviors of metal pollutants.展开更多
The single-locked photosensitizers(PSs)still suffer from off-target activation and skin phototoxicity in photodynamic therapy(PDT).Moreover,the efficacy of PDT is significantly limited by the antioxidant defense syste...The single-locked photosensitizers(PSs)still suffer from off-target activation and skin phototoxicity in photodynamic therapy(PDT).Moreover,the efficacy of PDT is significantly limited by the antioxidant defense system of tumor cells,particularly reduced glutathione(GSH).To address these limitations,we have developed a programmed activatable PS,designated as LET-19,specifically designed for acidity/GSH dual-locked PDT of tumors.LET-19 is constructed upon an iodinated cyanine structure,incorporating an oxazinane moiety and a 3,5-bis(trifluoromethyl)benzenethiol group.One lock is the oxazinane moiety that is capable of responding to acidic tumor microenvironment(TME),another lock is the 3,5-bis(trifluoromethyl)benzenethiol group that reacts to GSH.Notably,the fluorescence(FL),photoacoustic(PA),and photodynamic properties of LET-19 are initially suppressed.The programmed activation of acidity/GSH dual-locked PS is achieved by following steps:i)Once LET-19 enters tumor tissues,it is activated by the acidic TME;ii)Subsequently,LET-19 is taken up by tumor cells and further activated by GSH.Only in the occurrence of H+and GSH,whether in vitro or in vivo,both of the responsive units were sequentially recognized,thereby restoring FL/PA signals and the photodynamic capability of LET-19.This mechanism allows LET-19 to perform precise tumor identification by FL/PA dual-modality imaging,as well as improve the efficacy and safety of PDT.Meanwhile,in vitro and in vivo results demonstrate that LET-19 depletes GSH to inhibit the activity of glutathione peroxidase 4,disrupting redox homeostasis and thus amplifying the efficacy of PDT.This study provides a strategy to construct programmed activatable PSs for precision photodynamic theranostics of tumors.展开更多
Companion diagnostics(CDx)plays a pivotal role in precision medicine for cancer treatment.However,con-ventional CDx are often limited by their inability to provide real-time monitoring of cancer progression and therap...Companion diagnostics(CDx)plays a pivotal role in precision medicine for cancer treatment.However,con-ventional CDx are often limited by their inability to provide real-time monitoring of cancer progression and therapeutic responses.Herein,we develop a dual-modality imaging-based companion theranostic(CTx)nano-platform(LET-Cl@GOx),which integrates activatable photoacoustic(PA)and fluorescence(FL)imaging to enable the enhanced diagnostic accuracy and real-time therapeutic feedback,while demonstrating cascade-amplified photothermal/starvation synergistic therapy.The LET-Cl@GOx is designed by the assembly of glucose oxidase(GOx)with a pH-activatable near-infrared(NIR)dye(LET-Cl),enabling the turn-on of PA/FL imaging within the acidic tumor microenvironment(TME).The dynamic alterations of PA/FL imaging signals provide real-time feedback on TME acidification,enabling accurate monitoring of GOx catalysis progression and precision timing of photothermal therapy(PTT)intervention.Furthermore,the GOx-mediated tumor starvation reduces adenosine triphosphate(ATP)levels,leading to the diminished heat shock protein expression and consequently enhanced the sensitivity to PTT.Concurrently,the photothermal effect reciprocally enhances the catalytic activity of GOx,establishing a triple closed-loop system with positive feedback amplification.This multiscale-augmented synergistic therapy triggers robust pyroptosis via the Caspase-3/gasdermin E signaling pathway,demonstrating remarkable therapeutic efficacy of tumors in vivo.展开更多
The level of glutathione(GSH)is significantly associated with numerous pathological processes,thus,real-time detection of the GSH level is of significance for early diagnosis of GSH-related diseases.Herein,we develope...The level of glutathione(GSH)is significantly associated with numerous pathological processes,thus,real-time detection of the GSH level is of significance for early diagnosis of GSH-related diseases.Herein,we developed in vivo second near-infrared(NIR-II)window fluorescence(FL)and ratiometric photoacoustic(RPA)dual-modality imaging of GSH using a GSH-activatable probe(LET-14).LET-14 was synthesized based on a rhodamine hybrid xanthene skeleton with a FL shielding 2,4-dinitrobenzene sulfonyl group that can be specifically cleaved by GSH,thus resulting in a markedly bathochromic-shift absorption,a 6.5-fold increase in NIR-II FL intensity(FL_(920))and a 13-fold increase in RPA signal(PA_(880)/PA_(705))in vitro.Intriguingly,LET-14 exhibits good selectivity and sensitivity for NIR-II FL and RPA dual-modality imaging of GSH in 4T1 tumor-bearing mouse model.Our findings develop an in vivo detection tool of GSH,which has great potential in the field of cancer diagnosis.展开更多
L10-FePt nan oparticles(NPs)with high chemical ordering represent effective electrocatalysts to reduce the cost and enhance theircatalytic performanee in fuel cells.A molecular strategy of preparing highly ordered FeP...L10-FePt nan oparticles(NPs)with high chemical ordering represent effective electrocatalysts to reduce the cost and enhance theircatalytic performanee in fuel cells.A molecular strategy of preparing highly ordered FePt NPs was used by direct pyrolysis of a Fe,Pt-containing bimetallic complex.The resultant L10-FePt NPs had very high crystallinity as reflected by the obvious diffractionpatterns,clear lattice fringes and characteristic X-ray diffraction peaks,etc.Besides,the strong ferromagnetism with room temperaturecoercivity of 27 kOe further confirmed the face-centered tetrag on al(fet)phase in good agreement with the ordered nano structures.TheFePt NPs can be used as electrocatalysts to catalyze oxygen reduction reaction(ORR)in an O2·saturated 0.1 M HClO4 solution andhydrogen evolution reaction(HER)in the 0.5 M H2SO4 electrolyte with much better performance than commercial Pt/C,and showedquite high stability after 10,000 cycles.The strategy utilizing orga no metallic precursors to prepare metal alloy NPs was dem on strated tobe a reliable approach for improving the catalytic efficiency in fuel cells.展开更多
基金supported by the Natural Science Foundation of China (No. 41020114001, 50921064)the Ministry of Sciences and Technology (No. 2009AA06Z402,2008ZX07209-006-04)the CAS/SAFEA International Partnership Program for Creative Research Teams of"Ecosystem Processes and Services"
文摘The responses of activities, abundances and community structures of soil denitrifiers to mercury （Hg） stress were investigated through a short-term incubation experiment. Four soil treatments with different concentrations of Hg （CK, Hg25, Hg50, and Hg100, denoted as 0, 25, 50, and 100 mg Hg/kg dry soil, respectively） were incubated for 28 days. Soil denitrification enzyme activity （DEA） was measured at day 3, 7 and 28. The abundances and community structures of two denitrification concerning genes, nirS （cd1-nitrite reductase gene） and nosZ （nitrous oxide reductase gene）, were analyzed using real-time PCR and denaturing gradient gel electrophoresis （DGGE）. Results showed that soil DEA was significantly stimulated in the treatments of Hg25 and Hg50 compared with others at day 7. Meanwhile, no difference in the abundances of soil nirS and nosZ was found between Hg spiked treatments and CK, except the lower abundance of nirS （P 〈 0.05） in the Hg added treatments compared with that in the CK at day 28. The community structures of denitrifiers based on nirS gene presented obvious change at day 7 along with the Hg additions, however, no variation was found in all treatments based on the nosZ gene. The results indicated that Hg （Hg25 and Hg50） had a strongly short-term stimulation on soil DEA, and nirS gene is more sensitive than nosZ gene to Hg stress.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 51102230, 51462006, 51361005, 51863005, U1501242, 51371060 and 51671062)the Guangxi Natural Science Foundation (Nos. 2014GXNSFAA118401, 2013GXNSFBA019244, 2014GXNSFAA118319 and 2014GXNAFDA118005)+2 种基金Guangxi Key Laboratory of Information Materials (Nos. 161002-Z, 171027-Z and 161002-K)Guangxi Scientific Technology Team (No. 2012GXNSFGA06002, AA17202030)the Program for Postgraduate Joint Training Base of GUET-CJYRE (No. 20160513-14-Z)
文摘In this study, series of novel composite phase change materials(PCMs) were prepared through vacuum impregnation by using meso-porous carbon as a supporting matrix and n-octadcane as PCMs.The meso-porous carbon material was prepared through one-pot co-assembly method, using resorcinol and formaldehyde as carbon precursor, tetraethoxysilane as silica sources and triblock copolymer F127 as a template. And the phase behaviors of n-octadcane confined in the nano-porous structure of the meso-porous carbon were further investigated. Fourier transform-infrared spectroscopy spectra show that n-octadecane was effectively encapsulated in the porous structure of mesoporous carbon and the composite PCMs were successfully prepared. Differential scanning calorimetry results confirm that the composite PCMs possess a good phase change behavior, fast thermal-response rate and excellent thermal cycling stability. In addition, the composite PCMs possess expected heat storage and heat release properties. All these results demonstrate that the composite PCMs possess good comprehensive property so that they can be used widely in energy storage systems.
基金supported by the National Natural Science Foundation of China (Nos. U2032201 and 21976193 )the Canada Research Chairs Program。
文摘The transformation of mercury(Hg) in the environment plays a vital role in the cycling of Hg and its risk to the ecosystem and human health. Of particular importance are Hg oxidation/reduction and methylation/demethylation processes driven or mediated by the dynamics of light, microorganisms, and organic carbon, among others. Advances in understanding those Hg transformation processes determine our capacity of projecting and mitigating Hg risk. Here, we provide a critical analysis of major knowledge gaps in our understanding of Hg transformation in nature, with perspectives on approaches moving forward. Our analysis focuses on Hg transformation processes in the environment, as well as emerging methodology in exploring these processes. Future avenues for improving the understanding of Hg transformation processes to protect ecosystem and human health are also explored.
基金supported by the Key science and Technology Projects of Inner Mongolia Autonomous Region(No.2019ZD001)the National Natural Science Foundation of China(Nos.42077015,41771267 and 41877030)+1 种基金the National Key Research and Development Program of China(No.2016YFD0800403)the Fundamental Research Funds for the Central Universities(No.103-510320036)。
文摘Hausmannite is a common low valence Mn oxide mineral,with a distorted spinel structure,in surficial sediments.Although natural Mn oxides often contain various impurities of transitional metals(TMs),few studies have addressed the effect and related mechanism of TM doping on the reactivity of hausmannite with metal pollutants.Here,the reactivity of cobalt(Co)doped hausmannite with aqueous As(Ⅲ)and As(Ⅴ)was studied.Co doping decreased the point of zero charge of hausmannite and its adsorption capacity for As(Ⅴ).Despite a reduction of the initial As(Ⅲ)oxidation rate,Co-doped hausmannite could effectively oxidize As(Ⅲ)to As(Ⅴ),followed by the adsorption and fixation of a large amount of As(Ⅴ)on the mineral surface.Arsenic K-edge EXAFS analysis of the samples after As(Ⅴ)adsorption and As(Ⅲ)oxidation revealed that only As(Ⅴ)was adsorbed on the mineral surface,with an average As-Mn distance of 3.25–3.30 A,indicating the formation of bidentate binuclear complexes.These results provide new insights into the interaction mechanism between TMs and low valence Mn oxides and their effect on the geochemical behaviors of metal pollutants.
基金supported by National Natural Science Foundation of China(U23A2097,82302362,and T2421003)Shenzhen Science and Technology Program(JCYJ20220818095806014,KQTD20190929172538530,and JCYJ20240813143026034)+3 种基金the Key Project of Department of Education of Guangdong Province(2025ZDZX2060)Research Team Cultivation Program of Shenzhen University(2023QNT019)the Shenzhen University 2035 Program for Excellent Research(2023B006)the Program for Youzuzhikeyan of Shenzhen University(SZU2024YZZKY002).
文摘The single-locked photosensitizers(PSs)still suffer from off-target activation and skin phototoxicity in photodynamic therapy(PDT).Moreover,the efficacy of PDT is significantly limited by the antioxidant defense system of tumor cells,particularly reduced glutathione(GSH).To address these limitations,we have developed a programmed activatable PS,designated as LET-19,specifically designed for acidity/GSH dual-locked PDT of tumors.LET-19 is constructed upon an iodinated cyanine structure,incorporating an oxazinane moiety and a 3,5-bis(trifluoromethyl)benzenethiol group.One lock is the oxazinane moiety that is capable of responding to acidic tumor microenvironment(TME),another lock is the 3,5-bis(trifluoromethyl)benzenethiol group that reacts to GSH.Notably,the fluorescence(FL),photoacoustic(PA),and photodynamic properties of LET-19 are initially suppressed.The programmed activation of acidity/GSH dual-locked PS is achieved by following steps:i)Once LET-19 enters tumor tissues,it is activated by the acidic TME;ii)Subsequently,LET-19 is taken up by tumor cells and further activated by GSH.Only in the occurrence of H+and GSH,whether in vitro or in vivo,both of the responsive units were sequentially recognized,thereby restoring FL/PA signals and the photodynamic capability of LET-19.This mechanism allows LET-19 to perform precise tumor identification by FL/PA dual-modality imaging,as well as improve the efficacy and safety of PDT.Meanwhile,in vitro and in vivo results demonstrate that LET-19 depletes GSH to inhibit the activity of glutathione peroxidase 4,disrupting redox homeostasis and thus amplifying the efficacy of PDT.This study provides a strategy to construct programmed activatable PSs for precision photodynamic theranostics of tumors.
基金financially supported by the National Natural Science Foundation of China(U23A2097,82020108017,and 81921002)the Guangdong Basic and Applied Basic Research Foundation(2025A1515011950)+3 种基金the Shenzhen Science and Technology Program(KQTD20190929172538530,JCYJ20210324093815040)the Standard Project of Shanghai Science and Technology Commission(21DZ2203200)the Research Team Cultivation Program of Shenzhen University(2023QNT017 and 2023QNT019)the Shenzhen Uni-versity 2035 Program for Excellent Research.
文摘Companion diagnostics(CDx)plays a pivotal role in precision medicine for cancer treatment.However,con-ventional CDx are often limited by their inability to provide real-time monitoring of cancer progression and therapeutic responses.Herein,we develop a dual-modality imaging-based companion theranostic(CTx)nano-platform(LET-Cl@GOx),which integrates activatable photoacoustic(PA)and fluorescence(FL)imaging to enable the enhanced diagnostic accuracy and real-time therapeutic feedback,while demonstrating cascade-amplified photothermal/starvation synergistic therapy.The LET-Cl@GOx is designed by the assembly of glucose oxidase(GOx)with a pH-activatable near-infrared(NIR)dye(LET-Cl),enabling the turn-on of PA/FL imaging within the acidic tumor microenvironment(TME).The dynamic alterations of PA/FL imaging signals provide real-time feedback on TME acidification,enabling accurate monitoring of GOx catalysis progression and precision timing of photothermal therapy(PTT)intervention.Furthermore,the GOx-mediated tumor starvation reduces adenosine triphosphate(ATP)levels,leading to the diminished heat shock protein expression and consequently enhanced the sensitivity to PTT.Concurrently,the photothermal effect reciprocally enhances the catalytic activity of GOx,establishing a triple closed-loop system with positive feedback amplification.This multiscale-augmented synergistic therapy triggers robust pyroptosis via the Caspase-3/gasdermin E signaling pathway,demonstrating remarkable therapeutic efficacy of tumors in vivo.
基金supported by the National Natural Science Foundation of China(Nos.82372116,U23A2097)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515010620)+2 种基金Shenzhen Medical Research Fund(Nos.B2302047,A2302047)Shenzhen Science and Technology Program(No.JCYJ20220818095806014)Research Team Cultivation Program of Shenzhen University(No.2023QNT019).
文摘The level of glutathione(GSH)is significantly associated with numerous pathological processes,thus,real-time detection of the GSH level is of significance for early diagnosis of GSH-related diseases.Herein,we developed in vivo second near-infrared(NIR-II)window fluorescence(FL)and ratiometric photoacoustic(RPA)dual-modality imaging of GSH using a GSH-activatable probe(LET-14).LET-14 was synthesized based on a rhodamine hybrid xanthene skeleton with a FL shielding 2,4-dinitrobenzene sulfonyl group that can be specifically cleaved by GSH,thus resulting in a markedly bathochromic-shift absorption,a 6.5-fold increase in NIR-II FL intensity(FL_(920))and a 13-fold increase in RPA signal(PA_(880)/PA_(705))in vitro.Intriguingly,LET-14 exhibits good selectivity and sensitivity for NIR-II FL and RPA dual-modality imaging of GSH in 4T1 tumor-bearing mouse model.Our findings develop an in vivo detection tool of GSH,which has great potential in the field of cancer diagnosis.
基金This work was supported by the National Natural Science Foundation of China(No.21701112)Science,Technology and Innovation Committee of Shenzhen Municipality(No.JCYJ20170303160036674)+2 种基金Hong Kong Research Grants Council(PolyU153062/18R C4006-17G and HKUST16304117)the Hong Kong Polytechnic University(1-ZE1C)Ms Clarea Au(847S)for the Endowed Professorship in Energy.Special thanks were also given to Instrumental Analysis Center of Shenzhen University(Xili Campus).
文摘L10-FePt nan oparticles(NPs)with high chemical ordering represent effective electrocatalysts to reduce the cost and enhance theircatalytic performanee in fuel cells.A molecular strategy of preparing highly ordered FePt NPs was used by direct pyrolysis of a Fe,Pt-containing bimetallic complex.The resultant L10-FePt NPs had very high crystallinity as reflected by the obvious diffractionpatterns,clear lattice fringes and characteristic X-ray diffraction peaks,etc.Besides,the strong ferromagnetism with room temperaturecoercivity of 27 kOe further confirmed the face-centered tetrag on al(fet)phase in good agreement with the ordered nano structures.TheFePt NPs can be used as electrocatalysts to catalyze oxygen reduction reaction(ORR)in an O2·saturated 0.1 M HClO4 solution andhydrogen evolution reaction(HER)in the 0.5 M H2SO4 electrolyte with much better performance than commercial Pt/C,and showedquite high stability after 10,000 cycles.The strategy utilizing orga no metallic precursors to prepare metal alloy NPs was dem on strated tobe a reliable approach for improving the catalytic efficiency in fuel cells.
