Luminescent metal-organic frameworks(MOFs)have garnered significant attention due to their structural tunability and potential applications in solid-state lighting,bioimaging,sensing,anticounterfeiting,and other field...Luminescent metal-organic frameworks(MOFs)have garnered significant attention due to their structural tunability and potential applications in solid-state lighting,bioimaging,sensing,anticounterfeiting,and other fields.Nevertheless,due to the tendency of1,4-benzenedicarboxylic acid(BDC)to rotate within the framework,MOFs composed of it exhibit significant non-radiative energy dissipation and thus impair the emissive properties.In this study,efficient luminescence of MIL-140A nanocrystals(NCs)with BDC rotors as ligands is achieved by pressure treatment strategy.Pressure treatment effectively modulates the pore structure of the framework,enhancing the interactions between the N,N-dimethylformamide vip molecules and the BDC ligands.The enhanced host-vip interaction contributes to the structural rigidity of the MOF,thereby suppressing the rotation-induced excited-state energy loss.As a result,the pressure-treated MIL-140A NCs displayed bright blue-light emission,with the photoluminescence quantum yield increasing from an initial 6.8%to 69.2%.This study developed an effective strategy to improve the luminescence performance of rotor ligand MOFs,offers a new avenue for the rational design and synthesis of MOFs with superior luminescent properties.展开更多
Blue-light emitting materials with high purity and good luminous efficiency have attracted considerable attention from both academic and commercial researchers for their great potential use in OLEDs.In order to improv...Blue-light emitting materials with high purity and good luminous efficiency have attracted considerable attention from both academic and commercial researchers for their great potential use in OLEDs.In order to improve thermal stability and lower the possibility to generate fluorescence quenching of organic blue-light emitting materials formed by carbazole,a linear organic molecule containing carbazole and triarylamine group,named N4,N4’-bis(9-ethyl-9H-carbazol-3-yl)-N4,N4’-diphenyl-[1,1’-biphenyl]-4,4’-diamine(DPECB),was synthesized via the Buchwald-Hartwig reaction.The structure of DPECB was characterized by nuclear magnetic resonance(NMR)and infrared spectroscopy.The UV-Vis absorption spectrum shows that DPECB exhibits two strong absorption peaks in the near ultraviolet region(around 305 and 355 nm).The fluorescence emission spectrum indicates that DPECB displays blue light emission both in solution(428-445 nm)and solid-state(466 nm).Additionally,DPECB shows clearly aggregation-induced emission enhancement(AIEE)effect in the mixed solvent of DMF/H2O.As the thermogravimetric analysis shows,DPECB demonstrates excellent thermostability with a 5%decomposition temperature of 457℃owing to the introduction of triarylamine group.The electrochemical property of DPECB was studied through cyclic voltammetry,and its HOMO and LUMO energy levels are-5.27 and-2.25 eV,respectively.These results indicate that DPECB is a promising blue-light emitting material with potential commercial applications.展开更多
In this paper, we report on the first observation of blue-light emission bands from europium-doped tantalum pentoxide (Ta2O5:Eu) thin films prepared using a simple co-sputtering method. We prepared four specimens from...In this paper, we report on the first observation of blue-light emission bands from europium-doped tantalum pentoxide (Ta2O5:Eu) thin films prepared using a simple co-sputtering method. We prepared four specimens from one as-deposited sample, and we subsequently annealed them at 700°C, 800°C, 900°C, or 1000°C for 20 min. Four remarkable photoluminescence (PL) peaks at wavelengths of 600, 620, 650, and 700 nm due to the 5D0→7F1, 5D0→7F2, 5D0→7F3, and 5D0→7F4 transitions of Eu3+ were observed from all the specimens, and blue PL peaks around a wavelength of 450 nm were also observed from the specimens annealed at 800°C, 900°C, and 1000°C. The blue PL peaks seem to be originated from the 4f65d1→4f7 transition of Eu2+. Both Eu3+ and Eu2+ ions seem to exist in our Ta2O5:Eu co-sputtered thin films annealed at temperatures from 800°C to 1000°C. Such Ta2O5:Eu co-sputtered thin films seem to be used as multi-functional coating films having both anti-reflection and down-conversion effects for realizing high-efficiency silicon solar cells.展开更多
Rare earth-doped oxide thin-film phosphors may emerge as an alternate choice for the blue phosphor, due to their chemical and thermal stability in high vacuum and absence of corrosive gas emission under electron bomba...Rare earth-doped oxide thin-film phosphors may emerge as an alternate choice for the blue phosphor, due to their chemical and thermal stability in high vacuum and absence of corrosive gas emission under electron bombardment. The blue phosphors in this study were activated in air at temperatures suitable for glass substrates, which have been used in a number of applications. The effects of rare earth ions and oxide hosts on the blue-light-emitting properties of phosphors are discussed. In addition, novel blue-light emission was observed in certain typical undoped wide bandgap oxides. The luminescence of the oxides depends on the growth and annealing conditions under different atmospheres, suggesting that it is associated with the presence of oxygen vacancies. Radiative processes related to oxygen vacancies were also presented.展开更多
The phototropins phot1 and phot2 are plant blue-light receptors that mediate phototropism, chloroplast movements, stomatal opening, leaf expansion, the rapid Inhibition of hypocotyl growth in etiolated seedlings, and ...The phototropins phot1 and phot2 are plant blue-light receptors that mediate phototropism, chloroplast movements, stomatal opening, leaf expansion, the rapid Inhibition of hypocotyl growth in etiolated seedlings, and possibly solar tracking by leaves in those species in which It occurs. The phototroplns are plasma membrane-associated hydrophilic proteins with two chromophore domains （designated LOV1 and LOV2 for their resemblance to domains In other signaling proteins that detect light, oxygen, or voltage） in their Nterminal half and a classic serine/threonlne kinase domain in their C-terminal half. Both chromophore domains bind flavin mononucleotide （FMN） and both undergo light-activated formation of a covalent bond between a nearby cystelne and the C（4a） carbon of the FMN to form the signaling state. LOV2-cystelnyl adduct formation leads to the release downstream of a tightly bound amphlpathlc α-helix, a step required for activation of the klnase function. This cysteinyl adduct then slowly decays over a matter of seconds or minutes to return the photoreceptor chromophore modules to their ground state. Functional LOV2 is required for light-activated phosphorylation and for various blue-light responses mediated by the phototroplns. The function of LOV1 is still unknown, although It may serve to modulate the signal generated by LOV2. The LOV domain Is an ancient chromophore module found In a wide range of otherwise unrelated proteins In fungi and prokaryotes, the latter Including cyanobacterla, eubacterla, and archaea. Further general reviews on the phototropins are those by Celaya and Liscum （2005） and Christie and Briggs （2005）.展开更多
In the outer periclinal cytoplasm of leaf epidermal cells of an aquatic angiosperm Vallisneria, blue light induces ＂chloroplast de-anchoring＂, a rapid decline in the resistance of chloroplasts against centrifugal fo...In the outer periclinal cytoplasm of leaf epidermal cells of an aquatic angiosperm Vallisneria, blue light induces ＂chloroplast de-anchoring＂, a rapid decline in the resistance of chloroplasts against centrifugal force. Chloroplast de- anchoring is known induced within lmin of irradiation with high-fluence-rate blue light specifically, preceding the com- mencement of chloroplasts migration toward the anticlinal cytoplasm. However, its regulatory mechanism has remained elusive, although pharmacological analysis suggested that a calcium release from intracellular calcium stores is necessary for the response, in search of the responsible photoreceptors, immunoblotting analysis using antibodies against phototropins demonstrated that cross-reactive polypeptides of 120-kDa exist in the plasma-membrane fraction prepared from the leaves. In vitro phosphorylation analysis revealed that 120-kDa polypeptides were phosphorylated by exposure to blue light in a fluence-dependent manner. The blue-light-induced phosphorylation activity was sensitive to a Ser/Thr kinase inhibitor, staurosporine, and unusually was retained at a high level for a long time in darkness. Furthermore, phototropin gene homologs （Vallisneria PHOTOTROPINI and PHOTOTROPIN2） expressed in leaves were isolated. We propose that calcium- regulated chloroplast de-anchoring, possibly mediated by phototropins, is an initial process of the blue-light-induced avoidance response of chloroplasts in Vallisneria.展开更多
The novel fluorinated distyrylarylene, 4,4＇-bis（2,2-di（4-fluorophenyl）vinyl）biphenyl （DFPVBi）, was synthesized and fully characterized. The structure was confirmed with IR, 1↑H NMR, 13↑C NMR, 19↑F NMR and MS...The novel fluorinated distyrylarylene, 4,4＇-bis（2,2-di（4-fluorophenyl）vinyl）biphenyl （DFPVBi）, was synthesized and fully characterized. The structure was confirmed with IR, 1↑H NMR, 13↑C NMR, 19↑F NMR and MS analyses. Its electronic and photoluminescence properties were investigated by UV-Vis absorption, cyclic voltammetry and fluorescence spectroscopy. The energy levels of the highest occupied molecular orbital （HOMO） and the lowest unoccupied molecular orbital （LUMO） are --5.77 and --2.75 eV, respectively. The electroluminescence proper- ties of the organic light-emitting diode fabricated by DFPVBi were also studied. The device exhibits a pure blue emission peaked at 454 nm, which indicates a maximum luminance of 5872 cd/m^2 at 14.2 V and a maximum current efficiency of 2.82 cd/A at 10V, respectively.展开更多
Nonmuscle invasive bladder cancer is associated with a high risk of recurrence as well as progression to muscle-invasive disease.Therefore,adequate visualization and identification of malignant lesions as well as comp...Nonmuscle invasive bladder cancer is associated with a high risk of recurrence as well as progression to muscle-invasive disease.Therefore,adequate visualization and identification of malignant lesions as well as complete resection are critical.Traditional white-light cystoscopy is limited in its ability to detect bladder cancer,specifically carcinoma in situ.Blue-light cystoscopy makes use of the intravesical instillation of a heme precursor to differentiate areas of malignancy from normal tissue.A narrative review of the literature on the use of blue-light cystoscopy in bladder cancer was conducted.Blue-light cystoscopy has been shown in several randomized clinical trials to increase detection of Ta,T1,and carcinoma in situ,as well as reduce risk of recurrence at 12 months as compared with traditional white-light cystoscopy.Research into the effects of blue-light cystoscopy on risk of disease progression has produced mixed results,in part due to changing definitions of progression.However,more recent research suggests a correlation with decreased risk of progression.Whereas the use of blue-light was initially limited to rigid cystoscopy in the operating room,results from a recent randomized clinical trial showing enhanced detection of recurrent disease using blue-light in-office surveillance flexible cystoscopy have led to expanded Food and Drug Administration approval.Overall,blue-light cystoscopy offers promise as an enhancement to white-light cystoscopy for the detection of nonmuscle invasive bladder cancer and may yield additional benefits in reducing disease recurrence and progression.Further prospective research is needed to evaluate the true benefit of blue-light cystoscopy in terms of disease progression as well as the cost-effectiveness of this technique.展开更多
Copolymers containing alternating flexible aliphatic blocks and rigid poly (p-phenylenevinylene) (PPV) blocks were synthesized and characterized. It was found that the fluorescent intensity increases with increasing l...Copolymers containing alternating flexible aliphatic blocks and rigid poly (p-phenylenevinylene) (PPV) blocks were synthesized and characterized. It was found that the fluorescent intensity increases with increasing length of the flexible blocks. Bright blue-light emitting diodes were fabricated using PPV copolymers as electroluminescent layers. The devices show 190 cd/m2 light-emitting brightness at 460 nm and 15 V turn-on voltage. The effects of oxadiawle derivative PBD and tris(8-hydroxyquinoline) aluminum Alq3 electron-transporting layers on the luminance and stability of the devices are discussed.展开更多
基金supported by the National Key R&D Program of China(Grant No.2023YFA1406200)the National Natural Science Foundation of China(No.12274177 and 12304261)the China Postdoctoral Science Foundation(No.2024M751076)。
文摘Luminescent metal-organic frameworks(MOFs)have garnered significant attention due to their structural tunability and potential applications in solid-state lighting,bioimaging,sensing,anticounterfeiting,and other fields.Nevertheless,due to the tendency of1,4-benzenedicarboxylic acid(BDC)to rotate within the framework,MOFs composed of it exhibit significant non-radiative energy dissipation and thus impair the emissive properties.In this study,efficient luminescence of MIL-140A nanocrystals(NCs)with BDC rotors as ligands is achieved by pressure treatment strategy.Pressure treatment effectively modulates the pore structure of the framework,enhancing the interactions between the N,N-dimethylformamide vip molecules and the BDC ligands.The enhanced host-vip interaction contributes to the structural rigidity of the MOF,thereby suppressing the rotation-induced excited-state energy loss.As a result,the pressure-treated MIL-140A NCs displayed bright blue-light emission,with the photoluminescence quantum yield increasing from an initial 6.8%to 69.2%.This study developed an effective strategy to improve the luminescence performance of rotor ligand MOFs,offers a new avenue for the rational design and synthesis of MOFs with superior luminescent properties.
基金Fundamental Research Program of Shanxi Province(20210302124637,202203021211102,J20230701)。
文摘Blue-light emitting materials with high purity and good luminous efficiency have attracted considerable attention from both academic and commercial researchers for their great potential use in OLEDs.In order to improve thermal stability and lower the possibility to generate fluorescence quenching of organic blue-light emitting materials formed by carbazole,a linear organic molecule containing carbazole and triarylamine group,named N4,N4’-bis(9-ethyl-9H-carbazol-3-yl)-N4,N4’-diphenyl-[1,1’-biphenyl]-4,4’-diamine(DPECB),was synthesized via the Buchwald-Hartwig reaction.The structure of DPECB was characterized by nuclear magnetic resonance(NMR)and infrared spectroscopy.The UV-Vis absorption spectrum shows that DPECB exhibits two strong absorption peaks in the near ultraviolet region(around 305 and 355 nm).The fluorescence emission spectrum indicates that DPECB displays blue light emission both in solution(428-445 nm)and solid-state(466 nm).Additionally,DPECB shows clearly aggregation-induced emission enhancement(AIEE)effect in the mixed solvent of DMF/H2O.As the thermogravimetric analysis shows,DPECB demonstrates excellent thermostability with a 5%decomposition temperature of 457℃owing to the introduction of triarylamine group.The electrochemical property of DPECB was studied through cyclic voltammetry,and its HOMO and LUMO energy levels are-5.27 and-2.25 eV,respectively.These results indicate that DPECB is a promising blue-light emitting material with potential commercial applications.
文摘In this paper, we report on the first observation of blue-light emission bands from europium-doped tantalum pentoxide (Ta2O5:Eu) thin films prepared using a simple co-sputtering method. We prepared four specimens from one as-deposited sample, and we subsequently annealed them at 700°C, 800°C, 900°C, or 1000°C for 20 min. Four remarkable photoluminescence (PL) peaks at wavelengths of 600, 620, 650, and 700 nm due to the 5D0→7F1, 5D0→7F2, 5D0→7F3, and 5D0→7F4 transitions of Eu3+ were observed from all the specimens, and blue PL peaks around a wavelength of 450 nm were also observed from the specimens annealed at 800°C, 900°C, and 1000°C. The blue PL peaks seem to be originated from the 4f65d1→4f7 transition of Eu2+. Both Eu3+ and Eu2+ ions seem to exist in our Ta2O5:Eu co-sputtered thin films annealed at temperatures from 800°C to 1000°C. Such Ta2O5:Eu co-sputtered thin films seem to be used as multi-functional coating films having both anti-reflection and down-conversion effects for realizing high-efficiency silicon solar cells.
基金Project supported bythe National Natural Science Foundation of China (50472079)
文摘Rare earth-doped oxide thin-film phosphors may emerge as an alternate choice for the blue phosphor, due to their chemical and thermal stability in high vacuum and absence of corrosive gas emission under electron bombardment. The blue phosphors in this study were activated in air at temperatures suitable for glass substrates, which have been used in a number of applications. The effects of rare earth ions and oxide hosts on the blue-light-emitting properties of phosphors are discussed. In addition, novel blue-light emission was observed in certain typical undoped wide bandgap oxides. The luminescence of the oxides depends on the growth and annealing conditions under different atmospheres, suggesting that it is associated with the presence of oxygen vacancies. Radiative processes related to oxygen vacancies were also presented.
基金Supported by the National Science Foundation, USA, grants MCB 0091384 and 0444504 to WRB, MCB0444390 to RAB, and by the UK Biotechnology and Biological Sciences Research Council, grant BB/C000366/1 to JMC. Publication of this paper is supported by the National Natural Science Foundation of China （30624808） and Science Publication Foundation of the Chinese Academy of Sciences.
文摘The phototropins phot1 and phot2 are plant blue-light receptors that mediate phototropism, chloroplast movements, stomatal opening, leaf expansion, the rapid Inhibition of hypocotyl growth in etiolated seedlings, and possibly solar tracking by leaves in those species in which It occurs. The phototroplns are plasma membrane-associated hydrophilic proteins with two chromophore domains （designated LOV1 and LOV2 for their resemblance to domains In other signaling proteins that detect light, oxygen, or voltage） in their Nterminal half and a classic serine/threonlne kinase domain in their C-terminal half. Both chromophore domains bind flavin mononucleotide （FMN） and both undergo light-activated formation of a covalent bond between a nearby cystelne and the C（4a） carbon of the FMN to form the signaling state. LOV2-cystelnyl adduct formation leads to the release downstream of a tightly bound amphlpathlc α-helix, a step required for activation of the klnase function. This cysteinyl adduct then slowly decays over a matter of seconds or minutes to return the photoreceptor chromophore modules to their ground state. Functional LOV2 is required for light-activated phosphorylation and for various blue-light responses mediated by the phototroplns. The function of LOV1 is still unknown, although It may serve to modulate the signal generated by LOV2. The LOV domain Is an ancient chromophore module found In a wide range of otherwise unrelated proteins In fungi and prokaryotes, the latter Including cyanobacterla, eubacterla, and archaea. Further general reviews on the phototropins are those by Celaya and Liscum （2005） and Christie and Briggs （2005）.
基金supported by the Japanese Ministry of Education, Culture, Sports, Science and Technology (grant Nos. 19039020 and 20570037 to S.T.)
文摘In the outer periclinal cytoplasm of leaf epidermal cells of an aquatic angiosperm Vallisneria, blue light induces ＂chloroplast de-anchoring＂, a rapid decline in the resistance of chloroplasts against centrifugal force. Chloroplast de- anchoring is known induced within lmin of irradiation with high-fluence-rate blue light specifically, preceding the com- mencement of chloroplasts migration toward the anticlinal cytoplasm. However, its regulatory mechanism has remained elusive, although pharmacological analysis suggested that a calcium release from intracellular calcium stores is necessary for the response, in search of the responsible photoreceptors, immunoblotting analysis using antibodies against phototropins demonstrated that cross-reactive polypeptides of 120-kDa exist in the plasma-membrane fraction prepared from the leaves. In vitro phosphorylation analysis revealed that 120-kDa polypeptides were phosphorylated by exposure to blue light in a fluence-dependent manner. The blue-light-induced phosphorylation activity was sensitive to a Ser/Thr kinase inhibitor, staurosporine, and unusually was retained at a high level for a long time in darkness. Furthermore, phototropin gene homologs （Vallisneria PHOTOTROPINI and PHOTOTROPIN2） expressed in leaves were isolated. We propose that calcium- regulated chloroplast de-anchoring, possibly mediated by phototropins, is an initial process of the blue-light-induced avoidance response of chloroplasts in Vallisneria.
文摘The novel fluorinated distyrylarylene, 4,4＇-bis（2,2-di（4-fluorophenyl）vinyl）biphenyl （DFPVBi）, was synthesized and fully characterized. The structure was confirmed with IR, 1↑H NMR, 13↑C NMR, 19↑F NMR and MS analyses. Its electronic and photoluminescence properties were investigated by UV-Vis absorption, cyclic voltammetry and fluorescence spectroscopy. The energy levels of the highest occupied molecular orbital （HOMO） and the lowest unoccupied molecular orbital （LUMO） are --5.77 and --2.75 eV, respectively. The electroluminescence proper- ties of the organic light-emitting diode fabricated by DFPVBi were also studied. The device exhibits a pure blue emission peaked at 454 nm, which indicates a maximum luminance of 5872 cd/m^2 at 14.2 V and a maximum current efficiency of 2.82 cd/A at 10V, respectively.
基金supported by a grant from the National Cancer Institute(P30CA072720).
文摘Nonmuscle invasive bladder cancer is associated with a high risk of recurrence as well as progression to muscle-invasive disease.Therefore,adequate visualization and identification of malignant lesions as well as complete resection are critical.Traditional white-light cystoscopy is limited in its ability to detect bladder cancer,specifically carcinoma in situ.Blue-light cystoscopy makes use of the intravesical instillation of a heme precursor to differentiate areas of malignancy from normal tissue.A narrative review of the literature on the use of blue-light cystoscopy in bladder cancer was conducted.Blue-light cystoscopy has been shown in several randomized clinical trials to increase detection of Ta,T1,and carcinoma in situ,as well as reduce risk of recurrence at 12 months as compared with traditional white-light cystoscopy.Research into the effects of blue-light cystoscopy on risk of disease progression has produced mixed results,in part due to changing definitions of progression.However,more recent research suggests a correlation with decreased risk of progression.Whereas the use of blue-light was initially limited to rigid cystoscopy in the operating room,results from a recent randomized clinical trial showing enhanced detection of recurrent disease using blue-light in-office surveillance flexible cystoscopy have led to expanded Food and Drug Administration approval.Overall,blue-light cystoscopy offers promise as an enhancement to white-light cystoscopy for the detection of nonmuscle invasive bladder cancer and may yield additional benefits in reducing disease recurrence and progression.Further prospective research is needed to evaluate the true benefit of blue-light cystoscopy in terms of disease progression as well as the cost-effectiveness of this technique.
文摘Copolymers containing alternating flexible aliphatic blocks and rigid poly (p-phenylenevinylene) (PPV) blocks were synthesized and characterized. It was found that the fluorescent intensity increases with increasing length of the flexible blocks. Bright blue-light emitting diodes were fabricated using PPV copolymers as electroluminescent layers. The devices show 190 cd/m2 light-emitting brightness at 460 nm and 15 V turn-on voltage. The effects of oxadiawle derivative PBD and tris(8-hydroxyquinoline) aluminum Alq3 electron-transporting layers on the luminance and stability of the devices are discussed.
