Counterfeiting of modern banknotes poses a significant challenge,prompting the use of various preventive measures.One such measure is the magnetic anti-counterfeiting strip.However,due to its inherent weak magnetic pr...Counterfeiting of modern banknotes poses a significant challenge,prompting the use of various preventive measures.One such measure is the magnetic anti-counterfeiting strip.However,due to its inherent weak magnetic properties,visualizing its magnetic distribution has been a longstanding challenge.In this work,we introduce an innovative method by using a fiber optic diamond probe,a highly sensitive quantum sensor designed specifically for detecting extremely weak magnetic fields.We employ this probe to achieve high-resolution imaging of the magnetic fields associated with the RMB 50denomination anti-counterfeiting strip.Additionally,we conduct computer simulations by using COMSOL Multiphysics software to deduce the potential geometric characteristics and material composition of the magnetic region within the anti-counterfeiting strip.The findings and method presented in this study hold broader significance,extending the RMB 50 denomination to various denominations of the Chinese currency and other items that employ magnetic anti-counterfeiting strips.These advances have the potential to significantly improve and promote security measures in order to prevent the banknotes from being counterfeited.展开更多
The Sb^(3+) doping strategy has been proven to be an effective way to regulate the band gap and improve the photophysical properties of organic-inorganic hybrid metal halides(OIHMHs).However,the emission of Sb^(3+) io...The Sb^(3+) doping strategy has been proven to be an effective way to regulate the band gap and improve the photophysical properties of organic-inorganic hybrid metal halides(OIHMHs).However,the emission of Sb^(3+) ions in OIHMHs is primarily confined to the low energy region,resulting in yellow or red emissions.To date,there are few reports about green emission of Sb^(3+)-doped OIHMHs.Here,we present a novel approach for regulating the luminescence of Sb^(3+) ions in 0D C_(10)H_(2)_(2)N_(6)InCl_(7)·H_(2)O via hydrogen bond network,in which water molecules act as agents for hydrogen bonding.Sb^(3+)-doped C_(10)H_(2)2N_(6)InCl_(7)·H_(2)O shows a broadband green emission peaking at 540 nm and a high photoluminescence quantum yield(PLQY)of 80%.It is found that the intense green emission stems from the radiative recombination of the self-trapped excitons(STEs).Upon removal of water molecules with heat,C_(10)H_(2)_(2)N_(6)In_(1-x)Sb_(x)Cl_(7) generates yellow emis-sion,attributed to the breaking of the hydrogen bond network and large structural distortions of excited state.Once water molecules are adsorbed by C_(10)H_(2)_(2)N_(6)In_(1-x)Sb_(x)Cl_(7),it can subsequently emit green light.This water-induced reversible emission switching is successfully used for optical security and information encryption.Our findings expand the under-standing of how the local coordination structure influences the photophysical mechanism in Sb^(3+)-doped metal halides and provide a novel method to control the STEs emission.展开更多
Rheumatoid arthritis(RA)is a systemic autoimmune disease that is primarily manifested as synovitis and polyarticular opacity and typically leads to serious joint damage and irreversible disability,thus adversely affec...Rheumatoid arthritis(RA)is a systemic autoimmune disease that is primarily manifested as synovitis and polyarticular opacity and typically leads to serious joint damage and irreversible disability,thus adversely affecting locomotion ability and life quality.Consequently,good prognosis heavily relies on the early diagnosis and effective therapeutic monitoring of RA.Activatable fluorescent probes play vital roles in the detection and imaging of biomarkers for disease diagnosis and in vivo imaging.Herein,we review the fluorescent probes developed for the detection and imaging of RA biomarkers,namely reactive oxygen/nitrogen species(hypochlorous acid,peroxynitrite,hydroxyl radical,nitroxyl),pH,and cysteine,and address the related challenges and prospects to inspire the design of novel fluorescent probes and the improvement of their performance in RA studies.展开更多
Lithium hexafluorophosphate(LiPF_(6)),the most commonly used lithium battery electrolyte salt,is vulnerable to heat and humidity.Quantitative and qualitative determination the variation of LiPF_(6)have always relied o...Lithium hexafluorophosphate(LiPF_(6)),the most commonly used lithium battery electrolyte salt,is vulnerable to heat and humidity.Quantitative and qualitative determination the variation of LiPF_(6)have always relied on advanced equipment.Herein,we develop a fast,convenient,high-selective fluorescence detection method based on metal-organic cages(MOC),whose emission is enhanced by nearly 20 times in the presence of LiPF_(6)with good stability and photobleaching resistance.The fluorescent probe can also detect moisture in battery electrolyte.We propose and verify that the luminescence enhancement is due to the presence of hydrogen bond-induced enhanced emission effect in cages.Fluorescent excitation-emission matrix spectra and variable-temperature nuclear magnetic resonance spectroscopy are employed to clarify the role of hydrogen bonds in guest-loaded cages.Density functional theory(DFT)calculation is applied to simulate the structure of host-guest complexes and estimate the adsorption energy involved in the system.The precisely matched lock-and-key model paves a new way for designing and fabricating novel host structures,enabling specific recognition of other target compounds.展开更多
A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition...A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition to emitting strong fluorescence,the peroxidase activity of Co doped g-C_(3)N_(4)can catalyze the reaction of O-phenylenediamine and H_(2)O_(2)to produce diallyl phthalate which can emit yellow fluorescence at 570 nm.Through the decomposition of Hx by xanthine oxidase,Hx can be indirectly detected by the generating hydrogen peroxide based on the measurement of fluorescent ratio I(F_(570)/F_(370)).The linear range was 1.7-272.2 mg/kg(R^(2)=0.997),and the detection limit was 1.52 mg/kg(3σ/K,n=9).The established method was applied to Hx detection in bass,grass carp,and shrimp,and the data were verified by HPLC.The result shows that the established probe is sensitive,accurate,and reliable,and can be used for Hx detection in aquatic products.展开更多
Bay-site carboxyl functionalized perylene diimide derivative 1,7-COOH-PDI-C_(12)(PDI-COOH)was synthesized and distinct enhanced fluorescence was observed through combining with calcium ion(Ca^(2+))in THF/H_(2)O soluti...Bay-site carboxyl functionalized perylene diimide derivative 1,7-COOH-PDI-C_(12)(PDI-COOH)was synthesized and distinct enhanced fluorescence was observed through combining with calcium ion(Ca^(2+))in THF/H_(2)O solution.The assembly and fluorescence behavior of PDI-COOH/Ca^(2+)were studied in detail by changing hydration state with different concentrations.Based on the differences in assembly morphology and stoichiometric ratios of PDICOOH/Ca^(2+),we proposed the fluorescence emission mechanism of PDI-COOH/Ca^(2+)in THF/H_(2)O and THF,respectively.This work reveals a novel strategy of aggregated state fluorescence enhancement and reminds us of the important role of water in molecular fluorescence emission and assembly.展开更多
The development of effective and safe vehicles to deliver small interfering RNA(siRNA) and chemotherapeutics remains a major challenge in RNA interference-based combination therapy with chemotherapeutics,which has eme...The development of effective and safe vehicles to deliver small interfering RNA(siRNA) and chemotherapeutics remains a major challenge in RNA interference-based combination therapy with chemotherapeutics,which has emerged as a powerful platform to treat drug-resistant cancer cells.Herein,we describe the development of novel all-in-one fluorescent silicon nanoparticles(SiNPs)-based nanomedicine platform for imaging-guided co-delivery of siRNA and doxorubicin(DOX).This approach enhanced therapeutic efficacy in multidrug-resistant breast cancer cells(i.e.,MCF-7/ADR cells).Typically,the SiNP-based nanocarriers enhanced the stability of siRNA in a biological environment(i.e.,medium or RNase A) and imparted the responsive release behavior of siRNA,resulting in approximately 80% down-regulation of P-glycoprotein expression.Co-delivery of P-glycoprotein siRNA and DOX led to>35-fold decrease in the half maximal inhibitory concentration of DOX in comparison with free DOX,indicating the pronounced therapeutic efficiency of the resultant nanocomposites for drug-resistant breast cancer cells.The intracellular time-dependent release behaviors of siRNA and DOX were revealed through tracking the strong and stable fluorescence of SiNPs.These data provide valuable information for designing effective RNA interference-based co-delivery carriers.展开更多
Fluorescent silk is fundamentally important for the development of future tissue engineering scaffolds.Despite great progress in the preparation of a variety of colored silks,fluorescent silk with enhanced mechanical ...Fluorescent silk is fundamentally important for the development of future tissue engineering scaffolds.Despite great progress in the preparation of a variety of colored silks,fluorescent silk with enhanced mechanical properties has yet to be explored.In this study,we report on the fabrication of intrinsically super-strong fluorescent silk by feeding Bombyx mori silkworm carbon nanodots(CNDs).The CNDs were incorporated into silk fibroin,hindering the conformation transformation,confining crystallization,and inducing orientation of mesophase.The resultant silk exhibited super-strong mechanical properties with breaking strength of 521.9±82.7 MPa and breaking elongation of 19.2±4.3%,improvements of 55.1%and 53.6%,respectively,in comparison with regular silk.The CNDs-reinforced silk displayed intrinsic blue fluorescence when exposed to 405 nm laser and exhibited no cytotoxic effect on cells,suggesting that multi-functional silks would be potentially useful in bioimaging and other applications.展开更多
Multifunctional nanocarrier-based theranostics is supposed to overcome some key problems in cancer treatment.In this work,a novel method for the preparation of a fluorescent mesoporous silica–carbon dot nanohybrid wa...Multifunctional nanocarrier-based theranostics is supposed to overcome some key problems in cancer treatment.In this work,a novel method for the preparation of a fluorescent mesoporous silica–carbon dot nanohybrid was developed.Carbon dots(CDs),from folic acid as the raw material,were prepared in situ and anchored on the surface of amino-modified mesoporous silica nanoparticles(MSNs–NH2) via a microwave-assisted solvothermal reaction.The as-prepared nanohybrid(designated MSNs–CDs) not only exhibited strong and stable yellow emission but also preserved the unique features of MSNs(e.g.,mesoporous structure,large specific surface area,and good biocompatibility),demonstrating a potential capability for fluorescence imagingguided drug delivery.More interestingly,the MSNs–CDs nanohybrid was able to selectively target folate receptor-overexpressing cancer cells(e.g.,HeLa),indicating that folic acid still retained its function even after undergoing the solvothermal reaction.Benefited by these excellent properties,the fluorescent MSNs–CDs nanohybrid can be employed as a fluorescence-guided nanocarrier for the targeted deliveryof anticancer drugs(e.g.,doxorubicin),thereby enhancing chemotherapeutic efficacy and reducing side effects.Our studies may provide a facile strategy for the fabrication of multifunctional MSN-based theranostic platforms,which is beneficial in the diagnosis and therapy of cancers in future.展开更多
The utilization of diagnosis to guide/aid therapy procedures has shown great prospects in the era of personalized medicine along with the recognition of tumor heterogeneity and complexity.Herein,a kind of multifunctio...The utilization of diagnosis to guide/aid therapy procedures has shown great prospects in the era of personalized medicine along with the recognition of tumor heterogeneity and complexity.Herein,a kind of multifunctional silicon-based nanostructure,i.e.,gold nanoparticles-decorated fluorescent silicon nanorods(Au@SiNRs),is fabricated and exploited for tumor-targeted multimodal imaging-guided photothermal therapy.In particular,the prepared Au@SiNRs feature high photothermal conversion efficiency(~43.9%)and strong photothermal stability(photothermal performance stays constant after five-cycle NIR laser irradiation),making them high-performance agents for simultaneously photoacoustic and infrared thermal imaging.The Au@SiNRs are readily modified with targeting peptide ligands,enabling an enhanced tumor accumulation with a high value of^8.74%ID g?1.Taking advantages of these unique merits,the Au@SiNRs are superbly suitable for specifically ablating tumors in vivo without appreciable toxicity under the guidance of multimodal imaging.Typically,all the mice treated with the Au@SiNRs remain alive,and no distinct tumor recurrence is observed during 60-day investigation.展开更多
The developme nt of high-level an ti-co un terfeiti ng tech niq ues is of great sig nifica nee in econo mics and security issues.However,i ntricate read ing methods are required to obta in multi-level info rmati on st...The developme nt of high-level an ti-co un terfeiti ng tech niq ues is of great sig nifica nee in econo mics and security issues.However,i ntricate read ing methods are required to obta in multi-level info rmati on stored in differe nt colors,which greatly limits the applicati on of an ti-co un terfeit ing tech no logy on sol ving real world problems.Here in,we realize multicolor information anti-counterfeiting under simply external stimulation by utilizing the functional groups and multiple emission centers of lanthanide metal organic framework(Ln-MOFs)to tune luminescence color.Water responsive multicolor luminescence represented by both the tunable color from red to blue within the visible region and high sensitive responsivity has bee n achieved,owing to the in creased nonr adiative decay pathways and enhan ced Eu3+-to-liga nd en ergy back tra nsfer.Remarkably,i nfo rmatio n hidde n in differe nt colors n eeds to be read with a specific water content,which can be used as an en crypti on key to en sure the security of the info rmati on for high-level an ti-co un terfeiti ng.展开更多
To improve two-photon absorption(TPA)response of a newly synthesized probe,a series of ratiometric two-photon fluorescent Zn^(2+) sensors based on quinoline and DPA moieties have been designed.The one-photon absorptio...To improve two-photon absorption(TPA)response of a newly synthesized probe,a series of ratiometric two-photon fluorescent Zn^(2+) sensors based on quinoline and DPA moieties have been designed.The one-photon absorption,TPA,and emission properties of the experimental and designed probes before and after coordination with Zn^(2+) are investigated employing the density functional theory in combination with response functions.The design consists of two levels.In the first level of design,five probes are constructed through using several electron acceptors or donors to increase accepting or donating ability of the fluorophores.It shows that all the designed probes have stronger TPA intensities at longer wavelengths with respect to the experimental probe because of the increased intra-molecular charge transfer.Moreover,it is found that the probe 4 built by adding an acyl unit has the largest TPA cross section among the designed structures due to the form of longer conjugated length and more linear backbone.One dimethylamino terminal attached along the skeleton can improve TPA intensity more efficiently than two side amino groups.Therefore,in the second level of design,a new probe 7 is formed by both an acyl unit and a dimethylamino terminal.It exhibits that the TPA cross sections of probe 7 and its zinc complex increase dramatically.Furthermore,the fluorescence quantum yields of the designed probes4 and 7 are calculated in a new way,which makes use of the relation between the computed difference of dipole moment and the measured fluorescence quantum yield.The result shows that our design also improves the fluorescence quantum yield considerably.All in all,the designed probes 4 and 7 not only possess enhanced TPA intensities but also have large differences of emission wavelength upon Zn^(2+) coordination and strong fluorescence intensity,which demonstrates that they are potential ratiometric two-photon fluorescent probes.展开更多
Polyacrylamide microspheres have been suc- cessfully used to reduce water production in reservoirs, but it is impossible to distinguish polyacrylamide microspheres from polyacrylamide that is used to enhance oil recov...Polyacrylamide microspheres have been suc- cessfully used to reduce water production in reservoirs, but it is impossible to distinguish polyacrylamide microspheres from polyacrylamide that is used to enhance oil recovery and is already present in production fluids. In order to detect polyacrylamide microspheres in the reservoir pro- duced fluid, fluorescent polyacrylamide microspheres P（AM-BA-AMCO）, which fluoresce under ultraviolet irradiation, were synthesized via an inverse suspension polymerization. In order to keep the particle size distribu- tion in a narrow range, the synthesis conditions of the polymerization were studied, including the stirring speed and the concentrations of initiator, NaaCO3, and dispersant. The bonding characteristics of microspheres were deter- mined by Fourier transform infrared spectroscopy. The surface morphology of these microspheres was observed under ultraviolet irradiation with an inverse fluorescence microscope. A laboratory evaluation test showed that the fluorescent polymer microspheres had good water swelling capability, thus they had the ability to plug and migrate in a sand pack. The plugging rate was 99.8 % and the residual resistance coefficient was 800 after microsphere treatment in the sand pack. Furthermore, the fluorescent microspheres and their fragments were accurately detected under ultra- violet irradiation in the produced fluid, even though theyhad experienced extrusion and deformation in the sand pack.展开更多
We have constructed a retroviral vector mediated mammalian cell expression system of the capsid precursor protein of foot-and-mouth disease virus(FMDV).The recombinant retroviral vector pBABEpuro-P1-2A-EGFP was constr...We have constructed a retroviral vector mediated mammalian cell expression system of the capsid precursor protein of foot-and-mouth disease virus(FMDV).The recombinant retroviral vector pBABEpuro-P1-2A-EGFP was constructed by sequentially inserting capsid precursor protein gene(P1) of FMDV and enhanced green fluorescent protein gene(EGFP) into pBABEpuro.The recombinant retroviral vector and the pVSV-G plasmid were co-transfected into packaging cells(GP2-293) by liposomemediated transduction to produce the pseudovirus.The pseudovirus was used to infect BHK-21 cells and resistant cells were screened with puromycin.Green fluorescent proteins were observed by fluorescence microscopy and expression of the capsid precursor protein gene of FMDV was detected by indirect immunofluorescence.The recombinant retroviral vector pBABEpuro-P1-2A-EGFP was constructed successfully.The capsid precursor protein of FMDV and green fluorescent protein were expressed in BHK-21 cells.The mammalian cell expression system for the capsid precursor protein of FMDV has been constructed successfully,which lays the foundation of development of a FMDV subunit vaccine.展开更多
The combination of magnetic trap(MT) and fluorescence resonant energy transfer(FRET) allows for nanoscale measurements of configurational changes of biomolecules under force. However, the magnetic bead involved in MT ...The combination of magnetic trap(MT) and fluorescence resonant energy transfer(FRET) allows for nanoscale measurements of configurational changes of biomolecules under force. However, the magnetic bead involved in MT experiments introduces a substantial amount of background fluorescence which reduces the signal-to-noise ratio(SNR) of FRET significantly. Moreover, the short lifetime of the dye used in FRET limits the total sampling time when combined with MT. Here we use a moveable tube lens to adjust the wave front in the light pathway of MT so that both images of the magnetic bead and the fluorescent signals can be detected when long DNA handles are used to reduce the auto-fluorescence of the magnetic bead. We utilize the internal trigger of an electron multiplying charge-coupled device camera to control a shutter so that the dye can be excited intermittently when long time measurement of FRET is needed. As a demonstration of the hybrid technique, we observe the unfolding/refolding dynamics of a DNA hairpin and measure the DNA unwinding activity of the saccharomyces cerevisiae Pif1(Pif1). Our results show that the unwinding burst of Pif1 under external force is different from that without the force. In addition, the improvement provides a better SNR and a longer sampling time in experiments in the MT-FRET assay.展开更多
To estimate the life of vacuum fluorescent display （VFD） more accurately and reduce test time and cost, four constant stress accelerated life tests （CSALTs） were conducted on an accelerated life test model. In the...To estimate the life of vacuum fluorescent display （VFD） more accurately and reduce test time and cost, four constant stress accelerated life tests （CSALTs） were conducted on an accelerated life test model. In the model, statistical analysis of test data is achieved by applying lognormal function to describe the life distribution, and least square method （LSM） to calculate the mean value and the standard deviation of logarithm. As a result, the accelerated life equation was obtained, and then a self-developed software was developed to predict the VFD life. The data analysis results demonstrate that the VFD life submits to lognormal distribution, that the accelerated model meets the linear Arrhenius equation, and that the precise accelerated parameter makes it possible to acquire the life information of VFD within one month.展开更多
The properties of one-photon absorption(OPA),emission and two-photon absorption(TPA)of a bipyridine-based zinc ion probe are investigated employing the density functional theory in combination with response functions....The properties of one-photon absorption(OPA),emission and two-photon absorption(TPA)of a bipyridine-based zinc ion probe are investigated employing the density functional theory in combination with response functions.The responsive mechanism and coordination mode effect are explored.The structural fluctuation is illustrated by molecular dynamics simulation.The calculated OPA and emission wavelengths of the probe are consistent with the experimental data.It is found that the red-shift of OPA wavelength and the enhancement of TPA intensity are induced by the increased intra-molecular charge transfer mechanism upon metal binding.The structural fluctuation could result in the blue-shift of TPA wavelength and the decrease of the TPA cross section.The TPA properties are quite different among the zinc complexes with different coordination modes.The TPA wavelength of the complexes with two ligands is close to that of the probe,which is in agreement with the experimental observation.展开更多
Specific fluorophore was introduced into ionic liquid based on its tunability,thus a kind of novel fluorescent ionic liquid probe[P66614][HQS]was designed,synthesized and characterized.Compared with non-fluorescent HQ...Specific fluorophore was introduced into ionic liquid based on its tunability,thus a kind of novel fluorescent ionic liquid probe[P66614][HQS]was designed,synthesized and characterized.Compared with non-fluorescent HQS,ionic liquid[P66614][HQS]emitted a certain amount of fluorescence,which could be attributed to the well-delocalized frontier orbitals and its charge transfer character,as demonstrated by quantum chemical calculation.Considering the interaction of[P66614][HQS]with metal ions,the application for detecting specific substance as a chemical sensor,such as Al3+was investigated.Compared with the traditional probe HQS,significant improvements in Al^3+detecting was achieved by[P66614][HQS]with stronger binding ability,better sensitivity and selectivity.The better performance of[P66614][HQS]was contributed to the changed charge distribution,leading to the stronger binding interaction.We believe that this new fluorescent ionic liquid exhibited unique properties in detecting Al^3+in aqueous solution,which would broaden the application of ionic liquids.展开更多
The properties of one-photon absorption（OPA）, emission and two-photon absorption（TPA） of a di-2-picolylaminebased zinc ion sensor are investigated by employing the density functional theory in combination with res...The properties of one-photon absorption（OPA）, emission and two-photon absorption（TPA） of a di-2-picolylaminebased zinc ion sensor are investigated by employing the density functional theory in combination with response functions.The responsive mechanism is explored. It is found that the calculated OPA and TPA properties are quite consistent with experimental data. Because the intra-molecular charge transfer（ICT） increases upon zinc ion binding, the TPA intensity is enhanced dramatically. According to the model sensor, we design a series of zinc ion probes which differ by conjugation center, acceptor and donor moieties. The properties of OPA, emission and TPA of the designed molecules are calculated at the same computational level. Our results demonstrate that the OPA and emission wavelengths of the designed probes have large red-shifts after zinc ions have been bound. Comparing with the model sensor, the TPA intensities of the designed probes are enhanced significantly and the absorption positions are red-shifted to longer wavelength range. Furthermore, the TPA intensity can be improved greatly upon zinc ion binding due to the increased ICT mechanism. These compounds are potential excellent candidates for two-photon fluorescent zinc ion probes.展开更多
Objective: To study the role of macrophage inflammatory protein (MIP)-2γ in myocarditis pathogenesis in BALB/c mice. Methods: The relationship between the progression of Coxsarckie virus B3(CVB3) viral myocarditis an...Objective: To study the role of macrophage inflammatory protein (MIP)-2γ in myocarditis pathogenesis in BALB/c mice. Methods: The relationship between the progression of Coxsarckie virus B3(CVB3) viral myocarditis and experimental autoimmune myocarditis and MIP-2γ mRNA expression in mouse was studied by TaqMan real-time fluorescent quantitative RT-PCR. Results: MIP-2γ mRNA expression rose on 3 to 5 d after CVB3 infection, reached peak on 7 d, and returned to normal level until 14 d, which corresponded well with the disease course. The MIP-2γ mRNA expression level rose significantly on the day 18 d after immunization with porcine cardiac myosin, which was consistent with pathological examination. Conclusion: MIP-2γ may be involved in the pathogenesis of myocarditis.展开更多
基金Project supported by the National Key Research and Development Program of China (Grant No.2021YFB2012600)the Shanghai Aerospace Science and Technology Innovation Fund,China (Grant No.SAST-2022-102)。
文摘Counterfeiting of modern banknotes poses a significant challenge,prompting the use of various preventive measures.One such measure is the magnetic anti-counterfeiting strip.However,due to its inherent weak magnetic properties,visualizing its magnetic distribution has been a longstanding challenge.In this work,we introduce an innovative method by using a fiber optic diamond probe,a highly sensitive quantum sensor designed specifically for detecting extremely weak magnetic fields.We employ this probe to achieve high-resolution imaging of the magnetic fields associated with the RMB 50denomination anti-counterfeiting strip.Additionally,we conduct computer simulations by using COMSOL Multiphysics software to deduce the potential geometric characteristics and material composition of the magnetic region within the anti-counterfeiting strip.The findings and method presented in this study hold broader significance,extending the RMB 50 denomination to various denominations of the Chinese currency and other items that employ magnetic anti-counterfeiting strips.These advances have the potential to significantly improve and promote security measures in order to prevent the banknotes from being counterfeited.
基金National Natural Science Foundation of China(11974063)Graduate research innovation project,School of Optoelectronic Engineering,Chongqing University(GDYKC2023002)+1 种基金Fundamental Research Funds for the Central Universities(2022CDJQY-010)The authors extend their appreciation to the Deputyship for Research and Innovation,Ministry of Education in Saudi Arabia for funding this research work through the project no.(IFKSUOR3-073-9).
文摘The Sb^(3+) doping strategy has been proven to be an effective way to regulate the band gap and improve the photophysical properties of organic-inorganic hybrid metal halides(OIHMHs).However,the emission of Sb^(3+) ions in OIHMHs is primarily confined to the low energy region,resulting in yellow or red emissions.To date,there are few reports about green emission of Sb^(3+)-doped OIHMHs.Here,we present a novel approach for regulating the luminescence of Sb^(3+) ions in 0D C_(10)H_(2)_(2)N_(6)InCl_(7)·H_(2)O via hydrogen bond network,in which water molecules act as agents for hydrogen bonding.Sb^(3+)-doped C_(10)H_(2)2N_(6)InCl_(7)·H_(2)O shows a broadband green emission peaking at 540 nm and a high photoluminescence quantum yield(PLQY)of 80%.It is found that the intense green emission stems from the radiative recombination of the self-trapped excitons(STEs).Upon removal of water molecules with heat,C_(10)H_(2)_(2)N_(6)In_(1-x)Sb_(x)Cl_(7) generates yellow emis-sion,attributed to the breaking of the hydrogen bond network and large structural distortions of excited state.Once water molecules are adsorbed by C_(10)H_(2)_(2)N_(6)In_(1-x)Sb_(x)Cl_(7),it can subsequently emit green light.This water-induced reversible emission switching is successfully used for optical security and information encryption.Our findings expand the under-standing of how the local coordination structure influences the photophysical mechanism in Sb^(3+)-doped metal halides and provide a novel method to control the STEs emission.
基金supported by the National Natural Science Foundation of China(82072432)the China-Japan Friendship Hospital Horizontal Project/Spontaneous Research Funding(2022-HX-JC-7)+1 种基金the National High Level Hospital Clinical Research Funding(2022-NHLHCRF-PY-20)the Elite Medical Professionals project of China-Japan Friendship Hospital(ZRJY2021-GG12).
文摘Rheumatoid arthritis(RA)is a systemic autoimmune disease that is primarily manifested as synovitis and polyarticular opacity and typically leads to serious joint damage and irreversible disability,thus adversely affecting locomotion ability and life quality.Consequently,good prognosis heavily relies on the early diagnosis and effective therapeutic monitoring of RA.Activatable fluorescent probes play vital roles in the detection and imaging of biomarkers for disease diagnosis and in vivo imaging.Herein,we review the fluorescent probes developed for the detection and imaging of RA biomarkers,namely reactive oxygen/nitrogen species(hypochlorous acid,peroxynitrite,hydroxyl radical,nitroxyl),pH,and cysteine,and address the related challenges and prospects to inspire the design of novel fluorescent probes and the improvement of their performance in RA studies.
基金supported by National Natural Science Foundation of China(No.22278308,22109114 and 22102099)。
文摘Lithium hexafluorophosphate(LiPF_(6)),the most commonly used lithium battery electrolyte salt,is vulnerable to heat and humidity.Quantitative and qualitative determination the variation of LiPF_(6)have always relied on advanced equipment.Herein,we develop a fast,convenient,high-selective fluorescence detection method based on metal-organic cages(MOC),whose emission is enhanced by nearly 20 times in the presence of LiPF_(6)with good stability and photobleaching resistance.The fluorescent probe can also detect moisture in battery electrolyte.We propose and verify that the luminescence enhancement is due to the presence of hydrogen bond-induced enhanced emission effect in cages.Fluorescent excitation-emission matrix spectra and variable-temperature nuclear magnetic resonance spectroscopy are employed to clarify the role of hydrogen bonds in guest-loaded cages.Density functional theory(DFT)calculation is applied to simulate the structure of host-guest complexes and estimate the adsorption energy involved in the system.The precisely matched lock-and-key model paves a new way for designing and fabricating novel host structures,enabling specific recognition of other target compounds.
基金supported by the National Natural Science Foundation of China(21804050)the National Key R and D Program of China(2018YFD0901003)+2 种基金the Science and Technology Planning Project of Xiamen,China(3502Z20183031)the Fujian Provincial Fund Project(2018J01432)the Xiamen Science and Technology Planning Project,China(3502Z20183031)。
文摘A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition to emitting strong fluorescence,the peroxidase activity of Co doped g-C_(3)N_(4)can catalyze the reaction of O-phenylenediamine and H_(2)O_(2)to produce diallyl phthalate which can emit yellow fluorescence at 570 nm.Through the decomposition of Hx by xanthine oxidase,Hx can be indirectly detected by the generating hydrogen peroxide based on the measurement of fluorescent ratio I(F_(570)/F_(370)).The linear range was 1.7-272.2 mg/kg(R^(2)=0.997),and the detection limit was 1.52 mg/kg(3σ/K,n=9).The established method was applied to Hx detection in bass,grass carp,and shrimp,and the data were verified by HPLC.The result shows that the established probe is sensitive,accurate,and reliable,and can be used for Hx detection in aquatic products.
文摘Bay-site carboxyl functionalized perylene diimide derivative 1,7-COOH-PDI-C_(12)(PDI-COOH)was synthesized and distinct enhanced fluorescence was observed through combining with calcium ion(Ca^(2+))in THF/H_(2)O solution.The assembly and fluorescence behavior of PDI-COOH/Ca^(2+)were studied in detail by changing hydration state with different concentrations.Based on the differences in assembly morphology and stoichiometric ratios of PDICOOH/Ca^(2+),we proposed the fluorescence emission mechanism of PDI-COOH/Ca^(2+)in THF/H_(2)O and THF,respectively.This work reveals a novel strategy of aggregated state fluorescence enhancement and reminds us of the important role of water in molecular fluorescence emission and assembly.
基金financial support from the National Basic Research Program of China(973 Program,2013CB934400)the National Natural Science Foundation of China(Nos.21825402,31400860,21575096,and 21605109)+3 种基金the Natural Science Foundation of Jiangsu Province of China(BK20170061)a Project funded by Collaborative Innovation Center of Suzhou Nano Science&Technology(NANO-CIC)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 Project as well as Joint International Research Laboratory of Carbon-Based Functional Materials and Devices
文摘The development of effective and safe vehicles to deliver small interfering RNA(siRNA) and chemotherapeutics remains a major challenge in RNA interference-based combination therapy with chemotherapeutics,which has emerged as a powerful platform to treat drug-resistant cancer cells.Herein,we describe the development of novel all-in-one fluorescent silicon nanoparticles(SiNPs)-based nanomedicine platform for imaging-guided co-delivery of siRNA and doxorubicin(DOX).This approach enhanced therapeutic efficacy in multidrug-resistant breast cancer cells(i.e.,MCF-7/ADR cells).Typically,the SiNP-based nanocarriers enhanced the stability of siRNA in a biological environment(i.e.,medium or RNase A) and imparted the responsive release behavior of siRNA,resulting in approximately 80% down-regulation of P-glycoprotein expression.Co-delivery of P-glycoprotein siRNA and DOX led to>35-fold decrease in the half maximal inhibitory concentration of DOX in comparison with free DOX,indicating the pronounced therapeutic efficiency of the resultant nanocomposites for drug-resistant breast cancer cells.The intracellular time-dependent release behaviors of siRNA and DOX were revealed through tracking the strong and stable fluorescence of SiNPs.These data provide valuable information for designing effective RNA interference-based co-delivery carriers.
基金sponsored by the National Key Research and Development Program of China(2016YFA0201700,2016YFA0201702)the Fundamental Research Funds for the Central Universities(2232019A3-06,2232019D3-02)+2 种基金the National Key Research and Development Program of China(2018YFC1105800)the National Natural Science Foundation of China(21674018,51903045)the Shanghai Belt and Road Joint Laboratory of Advanced Fiber and Low-Dimension Materials(18520750400).
文摘Fluorescent silk is fundamentally important for the development of future tissue engineering scaffolds.Despite great progress in the preparation of a variety of colored silks,fluorescent silk with enhanced mechanical properties has yet to be explored.In this study,we report on the fabrication of intrinsically super-strong fluorescent silk by feeding Bombyx mori silkworm carbon nanodots(CNDs).The CNDs were incorporated into silk fibroin,hindering the conformation transformation,confining crystallization,and inducing orientation of mesophase.The resultant silk exhibited super-strong mechanical properties with breaking strength of 521.9±82.7 MPa and breaking elongation of 19.2±4.3%,improvements of 55.1%and 53.6%,respectively,in comparison with regular silk.The CNDs-reinforced silk displayed intrinsic blue fluorescence when exposed to 405 nm laser and exhibited no cytotoxic effect on cells,suggesting that multi-functional silks would be potentially useful in bioimaging and other applications.
基金the financial support from the National Natural Science Foundation of China(51872300 and U1832110)Ningbo Science and Technology Bureau(2016C50009)the W.C.Wong Education Foundation(rczx0800)
文摘Multifunctional nanocarrier-based theranostics is supposed to overcome some key problems in cancer treatment.In this work,a novel method for the preparation of a fluorescent mesoporous silica–carbon dot nanohybrid was developed.Carbon dots(CDs),from folic acid as the raw material,were prepared in situ and anchored on the surface of amino-modified mesoporous silica nanoparticles(MSNs–NH2) via a microwave-assisted solvothermal reaction.The as-prepared nanohybrid(designated MSNs–CDs) not only exhibited strong and stable yellow emission but also preserved the unique features of MSNs(e.g.,mesoporous structure,large specific surface area,and good biocompatibility),demonstrating a potential capability for fluorescence imagingguided drug delivery.More interestingly,the MSNs–CDs nanohybrid was able to selectively target folate receptor-overexpressing cancer cells(e.g.,HeLa),indicating that folic acid still retained its function even after undergoing the solvothermal reaction.Benefited by these excellent properties,the fluorescent MSNs–CDs nanohybrid can be employed as a fluorescence-guided nanocarrier for the targeted deliveryof anticancer drugs(e.g.,doxorubicin),thereby enhancing chemotherapeutic efficacy and reducing side effects.Our studies may provide a facile strategy for the fabrication of multifunctional MSN-based theranostic platforms,which is beneficial in the diagnosis and therapy of cancers in future.
基金financial support from the National Basic Research Program of China(973 Program,2013CB934400)the National Natural Science Foundation of China(21825402,31400860,21575096,and 21605109)+3 种基金the Natural Science Foundation of Jiangsu Province of China(BK20170061)Collaborative Innovation Center of Suzhou Nano Science and Technology,and the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 ProjectJoint International Research Laboratory of Carbon-Based Functional Materials and Devices.
文摘The utilization of diagnosis to guide/aid therapy procedures has shown great prospects in the era of personalized medicine along with the recognition of tumor heterogeneity and complexity.Herein,a kind of multifunctional silicon-based nanostructure,i.e.,gold nanoparticles-decorated fluorescent silicon nanorods(Au@SiNRs),is fabricated and exploited for tumor-targeted multimodal imaging-guided photothermal therapy.In particular,the prepared Au@SiNRs feature high photothermal conversion efficiency(~43.9%)and strong photothermal stability(photothermal performance stays constant after five-cycle NIR laser irradiation),making them high-performance agents for simultaneously photoacoustic and infrared thermal imaging.The Au@SiNRs are readily modified with targeting peptide ligands,enabling an enhanced tumor accumulation with a high value of^8.74%ID g?1.Taking advantages of these unique merits,the Au@SiNRs are superbly suitable for specifically ablating tumors in vivo without appreciable toxicity under the guidance of multimodal imaging.Typically,all the mice treated with the Au@SiNRs remain alive,and no distinct tumor recurrence is observed during 60-day investigation.
基金This work was supported by the National Natural Science Foundation of China(Nos.52025131,51632008,51772268,and 61721005)Zhejiang Provincial Natural Science Foundation of China(No.LD18E020001).
文摘The developme nt of high-level an ti-co un terfeiti ng tech niq ues is of great sig nifica nee in econo mics and security issues.However,i ntricate read ing methods are required to obta in multi-level info rmati on stored in differe nt colors,which greatly limits the applicati on of an ti-co un terfeit ing tech no logy on sol ving real world problems.Here in,we realize multicolor information anti-counterfeiting under simply external stimulation by utilizing the functional groups and multiple emission centers of lanthanide metal organic framework(Ln-MOFs)to tune luminescence color.Water responsive multicolor luminescence represented by both the tunable color from red to blue within the visible region and high sensitive responsivity has bee n achieved,owing to the in creased nonr adiative decay pathways and enhan ced Eu3+-to-liga nd en ergy back tra nsfer.Remarkably,i nfo rmatio n hidde n in differe nt colors n eeds to be read with a specific water content,which can be used as an en crypti on key to en sure the security of the info rmati on for high-level an ti-co un terfeiti ng.
基金Project supported by the Shandong Provincial Natural Science Foundation,China(Grant No.ZR2020MA078)。
文摘To improve two-photon absorption(TPA)response of a newly synthesized probe,a series of ratiometric two-photon fluorescent Zn^(2+) sensors based on quinoline and DPA moieties have been designed.The one-photon absorption,TPA,and emission properties of the experimental and designed probes before and after coordination with Zn^(2+) are investigated employing the density functional theory in combination with response functions.The design consists of two levels.In the first level of design,five probes are constructed through using several electron acceptors or donors to increase accepting or donating ability of the fluorophores.It shows that all the designed probes have stronger TPA intensities at longer wavelengths with respect to the experimental probe because of the increased intra-molecular charge transfer.Moreover,it is found that the probe 4 built by adding an acyl unit has the largest TPA cross section among the designed structures due to the form of longer conjugated length and more linear backbone.One dimethylamino terminal attached along the skeleton can improve TPA intensity more efficiently than two side amino groups.Therefore,in the second level of design,a new probe 7 is formed by both an acyl unit and a dimethylamino terminal.It exhibits that the TPA cross sections of probe 7 and its zinc complex increase dramatically.Furthermore,the fluorescence quantum yields of the designed probes4 and 7 are calculated in a new way,which makes use of the relation between the computed difference of dipole moment and the measured fluorescence quantum yield.The result shows that our design also improves the fluorescence quantum yield considerably.All in all,the designed probes 4 and 7 not only possess enhanced TPA intensities but also have large differences of emission wavelength upon Zn^(2+) coordination and strong fluorescence intensity,which demonstrates that they are potential ratiometric two-photon fluorescent probes.
基金supported by the National Natural Science Foundation of China (No.21273286)Doctoral Program Foundation of the Education Ministry (No.20130133110005)
文摘Polyacrylamide microspheres have been suc- cessfully used to reduce water production in reservoirs, but it is impossible to distinguish polyacrylamide microspheres from polyacrylamide that is used to enhance oil recovery and is already present in production fluids. In order to detect polyacrylamide microspheres in the reservoir pro- duced fluid, fluorescent polyacrylamide microspheres P（AM-BA-AMCO）, which fluoresce under ultraviolet irradiation, were synthesized via an inverse suspension polymerization. In order to keep the particle size distribu- tion in a narrow range, the synthesis conditions of the polymerization were studied, including the stirring speed and the concentrations of initiator, NaaCO3, and dispersant. The bonding characteristics of microspheres were deter- mined by Fourier transform infrared spectroscopy. The surface morphology of these microspheres was observed under ultraviolet irradiation with an inverse fluorescence microscope. A laboratory evaluation test showed that the fluorescent polymer microspheres had good water swelling capability, thus they had the ability to plug and migrate in a sand pack. The plugging rate was 99.8 % and the residual resistance coefficient was 800 after microsphere treatment in the sand pack. Furthermore, the fluorescent microspheres and their fragments were accurately detected under ultra- violet irradiation in the produced fluid, even though theyhad experienced extrusion and deformation in the sand pack.
基金supported by the National Programs for High Technology Research and Development of China (2006AA10A204)the Gansu Key Technologies R&D Program(ZGS-052-A41-0006-03)the Programs for Director Fund of Lanzhou Veterinary Research Institute
文摘We have constructed a retroviral vector mediated mammalian cell expression system of the capsid precursor protein of foot-and-mouth disease virus(FMDV).The recombinant retroviral vector pBABEpuro-P1-2A-EGFP was constructed by sequentially inserting capsid precursor protein gene(P1) of FMDV and enhanced green fluorescent protein gene(EGFP) into pBABEpuro.The recombinant retroviral vector and the pVSV-G plasmid were co-transfected into packaging cells(GP2-293) by liposomemediated transduction to produce the pseudovirus.The pseudovirus was used to infect BHK-21 cells and resistant cells were screened with puromycin.Green fluorescent proteins were observed by fluorescence microscopy and expression of the capsid precursor protein gene of FMDV was detected by indirect immunofluorescence.The recombinant retroviral vector pBABEpuro-P1-2A-EGFP was constructed successfully.The capsid precursor protein of FMDV and green fluorescent protein were expressed in BHK-21 cells.The mammalian cell expression system for the capsid precursor protein of FMDV has been constructed successfully,which lays the foundation of development of a FMDV subunit vaccine.
基金Supported by the National Natural Science Foundation of China under Grant No 11574382
文摘The combination of magnetic trap(MT) and fluorescence resonant energy transfer(FRET) allows for nanoscale measurements of configurational changes of biomolecules under force. However, the magnetic bead involved in MT experiments introduces a substantial amount of background fluorescence which reduces the signal-to-noise ratio(SNR) of FRET significantly. Moreover, the short lifetime of the dye used in FRET limits the total sampling time when combined with MT. Here we use a moveable tube lens to adjust the wave front in the light pathway of MT so that both images of the magnetic bead and the fluorescent signals can be detected when long DNA handles are used to reduce the auto-fluorescence of the magnetic bead. We utilize the internal trigger of an electron multiplying charge-coupled device camera to control a shutter so that the dye can be excited intermittently when long time measurement of FRET is needed. As a demonstration of the hybrid technique, we observe the unfolding/refolding dynamics of a DNA hairpin and measure the DNA unwinding activity of the saccharomyces cerevisiae Pif1(Pif1). Our results show that the unwinding burst of Pif1 under external force is different from that without the force. In addition, the improvement provides a better SNR and a longer sampling time in experiments in the MT-FRET assay.
基金Shanghai Municipal Natural Science Foun-dation (NO.09ZR1413000)Undergraduate Education High-land Construction Project of ShanghaiKey Technology R&D Program of Shanghai Municipality (No.08160510600)
文摘To estimate the life of vacuum fluorescent display （VFD） more accurately and reduce test time and cost, four constant stress accelerated life tests （CSALTs） were conducted on an accelerated life test model. In the model, statistical analysis of test data is achieved by applying lognormal function to describe the life distribution, and least square method （LSM） to calculate the mean value and the standard deviation of logarithm. As a result, the accelerated life equation was obtained, and then a self-developed software was developed to predict the VFD life. The data analysis results demonstrate that the VFD life submits to lognormal distribution, that the accelerated model meets the linear Arrhenius equation, and that the precise accelerated parameter makes it possible to acquire the life information of VFD within one month.
基金the Natural Science Foundation of Shandong Province,China(Grant No.ZR2014AM026).
文摘The properties of one-photon absorption(OPA),emission and two-photon absorption(TPA)of a bipyridine-based zinc ion probe are investigated employing the density functional theory in combination with response functions.The responsive mechanism and coordination mode effect are explored.The structural fluctuation is illustrated by molecular dynamics simulation.The calculated OPA and emission wavelengths of the probe are consistent with the experimental data.It is found that the red-shift of OPA wavelength and the enhancement of TPA intensity are induced by the increased intra-molecular charge transfer mechanism upon metal binding.The structural fluctuation could result in the blue-shift of TPA wavelength and the decrease of the TPA cross section.The TPA properties are quite different among the zinc complexes with different coordination modes.The TPA wavelength of the complexes with two ligands is close to that of the probe,which is in agreement with the experimental observation.
基金We acknowledge the support of the National Key Basic Research Program of China(2015CB251401)the Natural Science Foundation of China(21776239)+1 种基金Zhejiang Provincial Natural Science Foundation of China(LZ17B060001)the Fundamental Research Funds of the Central Universities,the instrument support of professor Peng Xiaogang,professor Jin Yizheng and associate professor Qin Haiyan.
文摘Specific fluorophore was introduced into ionic liquid based on its tunability,thus a kind of novel fluorescent ionic liquid probe[P66614][HQS]was designed,synthesized and characterized.Compared with non-fluorescent HQS,ionic liquid[P66614][HQS]emitted a certain amount of fluorescence,which could be attributed to the well-delocalized frontier orbitals and its charge transfer character,as demonstrated by quantum chemical calculation.Considering the interaction of[P66614][HQS]with metal ions,the application for detecting specific substance as a chemical sensor,such as Al3+was investigated.Compared with the traditional probe HQS,significant improvements in Al^3+detecting was achieved by[P66614][HQS]with stronger binding ability,better sensitivity and selectivity.The better performance of[P66614][HQS]was contributed to the changed charge distribution,leading to the stronger binding interaction.We believe that this new fluorescent ionic liquid exhibited unique properties in detecting Al^3+in aqueous solution,which would broaden the application of ionic liquids.
基金Project supported by the Shandong Provincial Natural Science Foundation,China(Grant No.ZR2014AM026)the National Natural Science Foundation of China(Grant Nos.11374195 and 11404193)the Taishan Scholar Project of Shandong Province,China
文摘The properties of one-photon absorption（OPA）, emission and two-photon absorption（TPA） of a di-2-picolylaminebased zinc ion sensor are investigated by employing the density functional theory in combination with response functions.The responsive mechanism is explored. It is found that the calculated OPA and TPA properties are quite consistent with experimental data. Because the intra-molecular charge transfer（ICT） increases upon zinc ion binding, the TPA intensity is enhanced dramatically. According to the model sensor, we design a series of zinc ion probes which differ by conjugation center, acceptor and donor moieties. The properties of OPA, emission and TPA of the designed molecules are calculated at the same computational level. Our results demonstrate that the OPA and emission wavelengths of the designed probes have large red-shifts after zinc ions have been bound. Comparing with the model sensor, the TPA intensities of the designed probes are enhanced significantly and the absorption positions are red-shifted to longer wavelength range. Furthermore, the TPA intensity can be improved greatly upon zinc ion binding due to the increased ICT mechanism. These compounds are potential excellent candidates for two-photon fluorescent zinc ion probes.
文摘Objective: To study the role of macrophage inflammatory protein (MIP)-2γ in myocarditis pathogenesis in BALB/c mice. Methods: The relationship between the progression of Coxsarckie virus B3(CVB3) viral myocarditis and experimental autoimmune myocarditis and MIP-2γ mRNA expression in mouse was studied by TaqMan real-time fluorescent quantitative RT-PCR. Results: MIP-2γ mRNA expression rose on 3 to 5 d after CVB3 infection, reached peak on 7 d, and returned to normal level until 14 d, which corresponded well with the disease course. The MIP-2γ mRNA expression level rose significantly on the day 18 d after immunization with porcine cardiac myosin, which was consistent with pathological examination. Conclusion: MIP-2γ may be involved in the pathogenesis of myocarditis.
