Soft tissue integration around titanium(Ti)implants is weaker than that around natural teeth,compromising long-term success of Ti implants.Carbon monoxide(CO)possesses distinctive therapeutic properties,rendering it a...Soft tissue integration around titanium(Ti)implants is weaker than that around natural teeth,compromising long-term success of Ti implants.Carbon monoxide(CO)possesses distinctive therapeutic properties,rendering it as a highly promising candidate for enhancing STI.However,achieving controlled CO generation at the STI interface remains challenging.Herein,a controlled CO-releasing dual-function coating was constructed on Ti surfaces.Under near-infrared(NIR)irradiation,the designed surface could actively accelerate CO generation for antibiosis against both aerobic and anaerobic bacteria.More importantly,in the absence of NIR,the slow release of CO induces macrophage polarization from pro-inflammatory phenotype towards pro-regenerative phenotype.In a rat implantation model with induced infection,the designed surface effectively controlled the bacterial infection,alleviates accompanying inflammation and modulated immune microenvironment,leading to enhanced STI.Single-cell sequencing revealed that the coating alters the cytokine profile within the soft tissue,thereby influencing cellular functions.Differentially expressed genes in macrophages are highly enriched in the PIK3-Akt pathway.Furthermore,the cellular communication between fibroblasts and macrophages was significantly enhanced through the CXCL12/CXCL14/CXCR4 and CSF1-CSF1R ligand-receptor pair.These findings indicate that our coating showed an appealing prospect for enhancing STI around Ti implants,which would ultimately contribute to the improved long-term success of Ti implants.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
Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide: H1N1, H3N2, and H1N2. European avian-Hke H1N1 viruses, which were initially detected in European pig populations in...Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide: H1N1, H3N2, and H1N2. European avian-Hke H1N1 viruses, which were initially detected in European pig populations in 1979, have been circulating in pigs in eastern China since 2007. In this study, six influenza A viruses were isolated from 60 swine lung samples collected from January to April 2011 in eastern China. Based on whole genome sequencing, molecular characteristics of two isolates were determined. Phylogenetic analysis showed the eight genes of the two isolates were closely related to those of the avian-like H1N1 viruses circulating in pig populations, especially similar to those found in China. Four potential glycosylation sites were observed at positions 13, 26, 198, 277 in the HA1 proteins of the two isolates. Due to the presence of a stop codon at codon 12, the isolates contained truncated PB1-F2 proteins. In this study, the isolates contained 591Q, 627E and 701N in the polymerase subunit PB2, which had been shown to be determinants of virulence and host adaptation. The isolates also had a D rather than E at position 92 of the NS1, a marker of mammalian adaptation. Both isolates contained the GPKV motif at the PDZ ligand domain of the 3' end of the NS1, a characteristic marker of the European avian-like swine viruses since about 1999, which is distinct from those of avian, human and classical swine viruses. The M2 proteins of the isolates have the mutation (S31N), a characteristic marker of the European avian-like swine viruses since about 1987, which may confer resistance to amantadine and rimantadine antivirals. Our findings further emphasize the importance of surveillance on the genetic diversity of influenza A viruses in pigs, and raise more concerns about the occurrence of cross-species transmission events.展开更多
A novel avian influenza A (H7N9) virus was discovered in February 2013 in China and has resulted in more than 100 comfirmed human infections including 26 fatal cases as of May 2, 2013. The situation raises many ur- ...A novel avian influenza A (H7N9) virus was discovered in February 2013 in China and has resulted in more than 100 comfirmed human infections including 26 fatal cases as of May 2, 2013. The situation raises many ur- gent questions and global public health concerns. In this study, epidemiologic characteristics of infected human cases in Jiangsu province were analyzed and risk assessment was undertaken based on the information available. Briefly, it is highly unlikely that a pandemic of human infection with avian influenza A (HTN9) virus will happen in Jiangsu Province in the near future. Iia the end, some measures are recommended to prevent the situation from becoming worse.展开更多
Guaiacol was chosen to represent O-containing chemicals with lower effective hydrogen carbon ratio(H/Ceff factor) in bio-oil,and the hydrodeoxygenation of guaiacol was investigated over non-precious and nonsulfided ...Guaiacol was chosen to represent O-containing chemicals with lower effective hydrogen carbon ratio(H/Ceff factor) in bio-oil,and the hydrodeoxygenation of guaiacol was investigated over non-precious and nonsulfided catalysts. Effects of metal composition,reaction temperature,and hydrogen pressure on conversion and selectivity were investigated systematically. Among various compositions of catalysts,Ni Co/CNT exhibited best performance of guaiacol conversion with higher selectivity towards desired alcohols with higher H/Cefffactor. The reaction pathways of guaiacol in aqueous were proposed based on the product analyzed.Results show that metal composition and temperature have great effects on the conversion of guaiacol and the yields of desired products.展开更多
Objective: To explore the relationships between the daily total intake of fluoride, dental fluorosis and dental caries. Methods: An epidemiological method was used to investigate the daily total intake of fluoride, ...Objective: To explore the relationships between the daily total intake of fluoride, dental fluorosis and dental caries. Methods: An epidemiological method was used to investigate the daily total intake of fluoride, dental fluorosis, and dental caries among 236 and 290 children aged 8-13 years in a severe endemic area and in a non-fluorosis control area, respectively. The children were divided into eight subgroups according to each child' s estimated daily total intake of fluoride. The prevalence of dental fluorosis and dental caries in each group was calculated. Results: As expected, elevated levels of fluoride intake were significantly associated with a higher prevalence of dental fluorosis and an increasing amount of more severe defect dental fluorosis. When the daily total F intake was 2.78 mg/child/day, the prevalence of dental fluorosis was nearly 100%, with the prevalence of defect dental fluorosis increasing with increasing fluoride intake. There was also a significant negative(inverse) dose-response relationship between the daily total intake of fluoride and the overall prevalence of dental caries, the prevalence of which decreased when the daily total intake of fluoride increased up to 3.32 mg/child/day. However, at higher levels of daily total intake of fluoride the prevalence of dental caries increased, giving rise to a U-shaped dose-response relationship curve. Conclusion: It is important to monitor total fluoride exposure and protect children from excessive fluoride intake, especially during the years of tooth development.展开更多
The actual incidence of human H7N9 infection is supposed to be much higher than the documented laboratoryconfirmed cases.In this study,we estimated the number of the actual H7N9 cases in Jiangsu,China using a probabil...The actual incidence of human H7N9 infection is supposed to be much higher than the documented laboratoryconfirmed cases.In this study,we estimated the number of the actual H7N9 cases in Jiangsu,China using a probabilistic multiplier model.Then,disability adjusted life years(DALYs),direct and indirect economic loss caused by this disease were calculated and analyzed.Till September 2017,the estimated total number of H7N9 cases was 2952[median,90%probability range(PR):1487-22094],which was 11.8 times(5.9-88.4)as large as the reported number.The median morbidity was estimated to be 4(90%PR:2-29)per 100000 population.The total DALYs loss was 16548 years,and the total economic loss(direct and indirect)was estimated to be RMB 1044618758(US$16.7 M).The average economic loss for per case and for per year was RMB 353868(US$56440)and RMB 232137502(US$37.0 M),respectively.The actual burden of human H7N9 infections was much heavier than what was documented.Our study provided an approach to estimate actual burden of infectious diseases using laboratory-confirmation.展开更多
Zirconia-loaded sulfuric acid (SO2-/ZrO2) catalysts were prepared by impregnation method, molded by punch tablet machine and characterized by X-ray diffraction. SO4^2-/ZrO2 catalyst was used to obtain glycerol triac...Zirconia-loaded sulfuric acid (SO2-/ZrO2) catalysts were prepared by impregnation method, molded by punch tablet machine and characterized by X-ray diffraction. SO4^2-/ZrO2 catalyst was used to obtain glycerol triacetate (GTA) directly from glycerin. The effect of some factors, such as different temperatures of calcination and catalysts molded or not, on the reusable times of catalysts and the yield of GTA were investigated. The optimum reaction conditions were shown as follows: the reaction temperature was 403 K; the reaction time continued for 8 h; the amount of molded catalysts was 5 wt% of glycerin and the molar ratio of glycerin to acetic acid was 1 : 8. The yield of GTA was 97.93% under the optimum condition.展开更多
This paper presents a review on the recent research and technical progress of electric motor systems and electric powertrains for new energy vehicles.Through the analysis and comparison of direct current motor,inducti...This paper presents a review on the recent research and technical progress of electric motor systems and electric powertrains for new energy vehicles.Through the analysis and comparison of direct current motor,induction motor,and synchronous motor,it is found that permanent magnet synchronous motor has better overall performance;by comparison with converters with Si-based IGBTs,it is found converters with SiC MOSFETs show significantly higher efficiency and increase driving mileage per charge.In addition,the pros and cons of different control strategies and algorithms are demonstrated.Next,by comparing series,parallel,and power split hybrid powertrains,the series-parallel compound hybrid powertrains are found to provide better fuel economy.Different electric powertrains,hybrid powertrains,and range-extended electric systems are also detailed,and their advantages and disadvantages are described.Finally,the technology roadmap over the next 15 years is proposed regarding traction motor,power electronic converter and electric powertrain as well as the key materials and components at each time frame.展开更多
The general approach for fabricating solid-state materials showing circularly polarized luminescence(CPL)is still in its challenge.In this work,chiral metal-organic frameworks(MOFs)with full-color and white-color circ...The general approach for fabricating solid-state materials showing circularly polarized luminescence(CPL)is still in its challenge.In this work,chiral metal-organic frameworks(MOFs)with full-color and white-color circularly polarized light emission are firstly achieved through a host-guest emitter-loading strategy.Chiral zeolitic imidazolate frameworks(ZIFs,a class of MOFs)are fabricated by a facile and simple mixed-ligand coassembly pathway.Meantime,achiral dyes,quantum dots(QDs),and upconversion nanoparticles(UCNPs)are easily loaded into the chiral ZIFs during the synthetic process.Size-matched dyes can be solely encapsulated into the chiral cages of ZIF,resulting in induced CPL and enhanced luminescence efficiency in solid-state ZIF⊃dye composites.Large-sized QDs,after embedding into the gap of the ZIF particles,also exhibited intense CPL activity.Furthermore,through modulating the blending ratio of colored dyes or QDs in chiral ZIFs,white light-emitting ZIFs with circular polarization could be constructed in a solid state.In addition,through loading rare earth element-based upconversion nanoparticles(UCNPs)into chiral ZIFs,upconverted CPL(UC-CPL)could be achieved with a high dissymmetry factor(glum).Thus,various achiral luminophores were endowed with CPL upon coupling with chiral ZIFs,which significantly deepened and enlarged the research scope of the chiroptical materials in a solid state.展开更多
Achieving large luminescence dissymmetry factors(pium)is challenging in the research field of circularly polarized luminescence(CPL).While various approaches have been developed to construct organic systems with CPL a...Achieving large luminescence dissymmetry factors(pium)is challenging in the research field of circularly polarized luminescence(CPL).While various approaches have been developed to construct organic systems with CPL activity,there is still a lack of effective methods for fabricating CPL active inorganic materials.Herein,we propose an approach for endowing upconversion nanoparticles(UCNPs)and perovskite nanocrystal(PKNC)hybrid nanomaterials with upconverted circularly polarized luminescence(UC-CPL)activity.Chiral cesium lead bromides(CsPbBr_(3))PKNCs were synthesized by a chiral-ligand-assistant method.Meanwhile,UCNP could be embedded into the chiral PKNC,enabling a photon upconvesion feature to the PKNC.The embedded UCNPs in PKNCs were confirmed by electron tomography.Consequently,various CPL activities,including prompt CPL,UC-CPL,and energy transfer enhanced circularly polarized luminescence(ET-CPL),were realized.The chiral perovskite nanocrystals could reabsorb the chiral energy generated from UCNPs,showing energy transfer enhanced CPL activity with four times magnification of the circular polarization.These findings provide a meaningful strategy for designing chiral photon upconversion inorganic nanomaterials with highly efficient UC-CPL activity.展开更多
基金support from the Natural Science Foundation of China(52073224 and 52073230)the Shaanxi Provincial Science Fund for Distinguished Young Scholars(2023-JC-JQ-32)+1 种基金Key Research and Development Program of Shaanxi(2024SFYBXM-438 and 2022SF-165)Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0225).
文摘Soft tissue integration around titanium(Ti)implants is weaker than that around natural teeth,compromising long-term success of Ti implants.Carbon monoxide(CO)possesses distinctive therapeutic properties,rendering it as a highly promising candidate for enhancing STI.However,achieving controlled CO generation at the STI interface remains challenging.Herein,a controlled CO-releasing dual-function coating was constructed on Ti surfaces.Under near-infrared(NIR)irradiation,the designed surface could actively accelerate CO generation for antibiosis against both aerobic and anaerobic bacteria.More importantly,in the absence of NIR,the slow release of CO induces macrophage polarization from pro-inflammatory phenotype towards pro-regenerative phenotype.In a rat implantation model with induced infection,the designed surface effectively controlled the bacterial infection,alleviates accompanying inflammation and modulated immune microenvironment,leading to enhanced STI.Single-cell sequencing revealed that the coating alters the cytokine profile within the soft tissue,thereby influencing cellular functions.Differentially expressed genes in macrophages are highly enriched in the PIK3-Akt pathway.Furthermore,the cellular communication between fibroblasts and macrophages was significantly enhanced through the CXCL12/CXCL14/CXCR4 and CSF1-CSF1R ligand-receptor pair.These findings indicate that our coating showed an appealing prospect for enhancing STI around Ti implants,which would ultimately contribute to the improved long-term success of Ti implants.
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Supported by the Natural Science Foundation of Jiangsu Province(BK2009434)the Innovation Platform for Public Health Emergency Preparedness and Response(NO.ZX201109)the Key Medical Talent Foundation of Jiangsu Province(RC2011084)
文摘Currently, three predominant subtypes of influenza virus are prevalent in pig populations worldwide: H1N1, H3N2, and H1N2. European avian-Hke H1N1 viruses, which were initially detected in European pig populations in 1979, have been circulating in pigs in eastern China since 2007. In this study, six influenza A viruses were isolated from 60 swine lung samples collected from January to April 2011 in eastern China. Based on whole genome sequencing, molecular characteristics of two isolates were determined. Phylogenetic analysis showed the eight genes of the two isolates were closely related to those of the avian-like H1N1 viruses circulating in pig populations, especially similar to those found in China. Four potential glycosylation sites were observed at positions 13, 26, 198, 277 in the HA1 proteins of the two isolates. Due to the presence of a stop codon at codon 12, the isolates contained truncated PB1-F2 proteins. In this study, the isolates contained 591Q, 627E and 701N in the polymerase subunit PB2, which had been shown to be determinants of virulence and host adaptation. The isolates also had a D rather than E at position 92 of the NS1, a marker of mammalian adaptation. Both isolates contained the GPKV motif at the PDZ ligand domain of the 3' end of the NS1, a characteristic marker of the European avian-like swine viruses since about 1999, which is distinct from those of avian, human and classical swine viruses. The M2 proteins of the isolates have the mutation (S31N), a characteristic marker of the European avian-like swine viruses since about 1987, which may confer resistance to amantadine and rimantadine antivirals. Our findings further emphasize the importance of surveillance on the genetic diversity of influenza A viruses in pigs, and raise more concerns about the occurrence of cross-species transmission events.
基金supported by the Jiangsu Province Health Development Project with Science and Education (No.ZX201109 and RC2011085)the Research Projects of Jiangsu Preventive Medicine (No.YZ201020)
文摘A novel avian influenza A (H7N9) virus was discovered in February 2013 in China and has resulted in more than 100 comfirmed human infections including 26 fatal cases as of May 2, 2013. The situation raises many ur- gent questions and global public health concerns. In this study, epidemiologic characteristics of infected human cases in Jiangsu province were analyzed and risk assessment was undertaken based on the information available. Briefly, it is highly unlikely that a pandemic of human infection with avian influenza A (HTN9) virus will happen in Jiangsu Province in the near future. Iia the end, some measures are recommended to prevent the situation from becoming worse.
基金support from the National Hi-tech Research and Development Program of China (863 Program) (2012AA051801)the Fundamental Research Funds for the Central Universities (No.CXZZ13_0112)the Scientific Research Foundation of Graduate School of Southeast University (YBPY1408)
文摘Guaiacol was chosen to represent O-containing chemicals with lower effective hydrogen carbon ratio(H/Ceff factor) in bio-oil,and the hydrodeoxygenation of guaiacol was investigated over non-precious and nonsulfided catalysts. Effects of metal composition,reaction temperature,and hydrogen pressure on conversion and selectivity were investigated systematically. Among various compositions of catalysts,Ni Co/CNT exhibited best performance of guaiacol conversion with higher selectivity towards desired alcohols with higher H/Cefffactor. The reaction pathways of guaiacol in aqueous were proposed based on the product analyzed.Results show that metal composition and temperature have great effects on the conversion of guaiacol and the yields of desired products.
基金supported by Jiangsu Provincial Foundation of Prevention Medicine(Y200621)
文摘Objective: To explore the relationships between the daily total intake of fluoride, dental fluorosis and dental caries. Methods: An epidemiological method was used to investigate the daily total intake of fluoride, dental fluorosis, and dental caries among 236 and 290 children aged 8-13 years in a severe endemic area and in a non-fluorosis control area, respectively. The children were divided into eight subgroups according to each child' s estimated daily total intake of fluoride. The prevalence of dental fluorosis and dental caries in each group was calculated. Results: As expected, elevated levels of fluoride intake were significantly associated with a higher prevalence of dental fluorosis and an increasing amount of more severe defect dental fluorosis. When the daily total F intake was 2.78 mg/child/day, the prevalence of dental fluorosis was nearly 100%, with the prevalence of defect dental fluorosis increasing with increasing fluoride intake. There was also a significant negative(inverse) dose-response relationship between the daily total intake of fluoride and the overall prevalence of dental caries, the prevalence of which decreased when the daily total intake of fluoride increased up to 3.32 mg/child/day. However, at higher levels of daily total intake of fluoride the prevalence of dental caries increased, giving rise to a U-shaped dose-response relationship curve. Conclusion: It is important to monitor total fluoride exposure and protect children from excessive fluoride intake, especially during the years of tooth development.
基金supported by the Science&Technology Demonstration Project for Emerging Infectious Diseases Control and Prevention under Grant(BE2015714&BE2017749)supported by the Key Medical Discipline of Jiangsu Science&Technology Project under Grant(epidemiology,ZDXKA2016008)+1 种基金supported by the National Science and Technology Major Project under Grant(2015ZX09101044)the Jiangsu Provincial Medical Youth Talents under Grant(QNRC2016539)
文摘The actual incidence of human H7N9 infection is supposed to be much higher than the documented laboratoryconfirmed cases.In this study,we estimated the number of the actual H7N9 cases in Jiangsu,China using a probabilistic multiplier model.Then,disability adjusted life years(DALYs),direct and indirect economic loss caused by this disease were calculated and analyzed.Till September 2017,the estimated total number of H7N9 cases was 2952[median,90%probability range(PR):1487-22094],which was 11.8 times(5.9-88.4)as large as the reported number.The median morbidity was estimated to be 4(90%PR:2-29)per 100000 population.The total DALYs loss was 16548 years,and the total economic loss(direct and indirect)was estimated to be RMB 1044618758(US$16.7 M).The average economic loss for per case and for per year was RMB 353868(US$56440)and RMB 232137502(US$37.0 M),respectively.The actual burden of human H7N9 infections was much heavier than what was documented.Our study provided an approach to estimate actual burden of infectious diseases using laboratory-confirmation.
基金supported by the National High Technology Research and Development Program of China (No. 2009AA03Z222 and No. 2009AA05Z437)the "Six Talents Pinnacle Program" of Jiangsu Province of China (No. 2008028)
文摘Zirconia-loaded sulfuric acid (SO2-/ZrO2) catalysts were prepared by impregnation method, molded by punch tablet machine and characterized by X-ray diffraction. SO4^2-/ZrO2 catalyst was used to obtain glycerol triacetate (GTA) directly from glycerin. The effect of some factors, such as different temperatures of calcination and catalysts molded or not, on the reusable times of catalysts and the yield of GTA were investigated. The optimum reaction conditions were shown as follows: the reaction temperature was 403 K; the reaction time continued for 8 h; the amount of molded catalysts was 5 wt% of glycerin and the molar ratio of glycerin to acetic acid was 1 : 8. The yield of GTA was 97.93% under the optimum condition.
文摘This paper presents a review on the recent research and technical progress of electric motor systems and electric powertrains for new energy vehicles.Through the analysis and comparison of direct current motor,induction motor,and synchronous motor,it is found that permanent magnet synchronous motor has better overall performance;by comparison with converters with Si-based IGBTs,it is found converters with SiC MOSFETs show significantly higher efficiency and increase driving mileage per charge.In addition,the pros and cons of different control strategies and algorithms are demonstrated.Next,by comparing series,parallel,and power split hybrid powertrains,the series-parallel compound hybrid powertrains are found to provide better fuel economy.Different electric powertrains,hybrid powertrains,and range-extended electric systems are also detailed,and their advantages and disadvantages are described.Finally,the technology roadmap over the next 15 years is proposed regarding traction motor,power electronic converter and electric powertrain as well as the key materials and components at each time frame.
基金This work was supported by the National Natural Science Foundation of China(51673050 and 91856115)the Ministry of Science and Technology of the People’s Republic of China(2017YFA0206600 and 2016YFA0203400)。
文摘The general approach for fabricating solid-state materials showing circularly polarized luminescence(CPL)is still in its challenge.In this work,chiral metal-organic frameworks(MOFs)with full-color and white-color circularly polarized light emission are firstly achieved through a host-guest emitter-loading strategy.Chiral zeolitic imidazolate frameworks(ZIFs,a class of MOFs)are fabricated by a facile and simple mixed-ligand coassembly pathway.Meantime,achiral dyes,quantum dots(QDs),and upconversion nanoparticles(UCNPs)are easily loaded into the chiral ZIFs during the synthetic process.Size-matched dyes can be solely encapsulated into the chiral cages of ZIF,resulting in induced CPL and enhanced luminescence efficiency in solid-state ZIF⊃dye composites.Large-sized QDs,after embedding into the gap of the ZIF particles,also exhibited intense CPL activity.Furthermore,through modulating the blending ratio of colored dyes or QDs in chiral ZIFs,white light-emitting ZIFs with circular polarization could be constructed in a solid state.In addition,through loading rare earth element-based upconversion nanoparticles(UCNPs)into chiral ZIFs,upconverted CPL(UC-CPL)could be achieved with a high dissymmetry factor(glum).Thus,various achiral luminophores were endowed with CPL upon coupling with chiral ZIFs,which significantly deepened and enlarged the research scope of the chiroptical materials in a solid state.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB36000000)the National Natural Science Foundation of China(Nos.21802027,21908161,51673050,and 91856115)+1 种基金the Ministry of Science and Technology of the Peoples Republic of China(No.2017YFA0206600,and 2016YFA0203400)Beijing Natural Science Foundation(No.2212023)。
文摘Achieving large luminescence dissymmetry factors(pium)is challenging in the research field of circularly polarized luminescence(CPL).While various approaches have been developed to construct organic systems with CPL activity,there is still a lack of effective methods for fabricating CPL active inorganic materials.Herein,we propose an approach for endowing upconversion nanoparticles(UCNPs)and perovskite nanocrystal(PKNC)hybrid nanomaterials with upconverted circularly polarized luminescence(UC-CPL)activity.Chiral cesium lead bromides(CsPbBr_(3))PKNCs were synthesized by a chiral-ligand-assistant method.Meanwhile,UCNP could be embedded into the chiral PKNC,enabling a photon upconvesion feature to the PKNC.The embedded UCNPs in PKNCs were confirmed by electron tomography.Consequently,various CPL activities,including prompt CPL,UC-CPL,and energy transfer enhanced circularly polarized luminescence(ET-CPL),were realized.The chiral perovskite nanocrystals could reabsorb the chiral energy generated from UCNPs,showing energy transfer enhanced CPL activity with four times magnification of the circular polarization.These findings provide a meaningful strategy for designing chiral photon upconversion inorganic nanomaterials with highly efficient UC-CPL activity.