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Three-Dimensional Superlattices Based on Unusual Chalcogenide Supertetrahedral In–Sn–S Nanoclusters
摘要： Reported here are two novel metal chalcogenide superlattices built from unusual supertetrahedral TO2-InSnS clusters. With regard to only one previously reported case of a TO2-InS-based 2D-layered structure, such a combination of In?Sn?S components is leading to the first observation of 3D superlattices based on TO2-InSnS clusters. Besides, these title semiconducting materials also display good performance on the electrocatalytic oxygen reduction reaction.
关键词： 3D superlattices,metal chalcogenide,electrocatalytic oxygen reduction reaction,supertetrahedral clusters
更新于2025-09-04 15:30:14
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Multimodal imaging and diagnosis of myopic choroidal neovascularization in Caucasians
摘要： Purpose: To investigate myopic choroidal neovascularization (mCNV) by fluorescein angiography (FA), spectral-domain optical coherence tomography (SD-OCT), near-infrared (NIR) reflectance, and autofluorescence (AF). Methods: This retrospective study included 65 eyes of 62 Caucasian patients with a mean age of 66.72 years (95% confidence interval [CI] 63–70 years) and a mean refraction of -9.72 diopters (95% CI -8.74 to -10.70 diopters). Results: Most of the mCNV cases were foveal-juxtafoveal (60/65, 92.3%), with thickening of the corresponding retina (62/65, 95.3%) and leakage on FA (44/65, 67.6%). No retinal fluid was detectable in 32 (49.2%) eyes and there was no hemorrhage in 25 (38.4%) eyes. Papillary chorioretinal atrophy was evident in 58 (89.2%), a shadowing effect in 48 (73.8%), and an epiretinal membrane in 38 (58.4%) eyes. If an area of macular chorioretinal atrophy was present, mCNV frequently developed adjacent to it and was hyperfluorescent rather than with leakage (P<0.001). In eyes with edema or hemorrhage, hyper-reflective foci were more frequent (P<0.005). NIR and AF features were indeterminable in 19 (29.2%) and 27 (41.5%) eyes, respectively. The predominant feature was black or grayish on NIR (34/65, 52.3%) and patchy (hypo- and hyperfluorescence was observed) on AF (25/65, 38.4%). FA and SD-OCT correctly detected mCNV in 49 (75.3%) and 48 (73.8%) eyes, respectively, whereas NIR and AF exhibited limited diagnostic sensitivity. Doubtful diagnosis was associated with hyperfluorescent mCNV (P<0.001), absence of retinal fluid and epiretinal membrane (P<0.05), and presence of macular chorioretinal atrophy (P<0.01). Conclusion: Tomographic, angiographic, AF, and NIR features of mCNV are described in this study. Combination of SD-OCT and FA is recommendable for diagnosis.
关键词： fluorescein angiography,pathologic myopia,myopic neovascularization,SD-OCT,CNV,imaging
更新于2025-09-04 15:30:14
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Heterometallic Organic Frameworks Built from Trinuclear Indium and Cuprous Halide Clusters: Ligand-Oriented Assemblies and Iodine Adsorption Behavior
摘要： Two novel heterometallic organic frameworks built from trinuclear indium and cuprous halide clusters, [(In3O)2(Cu2I2)3(ina)12(H2O)6](NO3)2·7DMA·10H2O (1) and [NH2(CH3)2][In3(OH)2(H2O)2(ina)8(Cu4I4)2]·5DMA·8H2O (2), where Hina = isonicotinic acid, have been successfully constructed with the orientation of the ina ligand. 1 shows a fascinating highly porous honeycomb-like 3D cationic framework with a trigonal-bipyramid-type cage based on a planar [In3O(CO2)6]+ trimer and a rhombohedral Cu2I2 cluster. Comparably, 2 displays a 3D negative network with irregular hexagonal channels constructed from a [In3(OH)2(CO2)8]? trimer and a cubane-like Cu4I4 cluster. Especially, 1 displays a reversible I2 adsorption/release performance with high adsorption capacity, whose mechanism has been disclosed by theoretical simulation. Also, the green/red emission of 2 stems from iodocuprate centers with quenched indium-centered emission.
关键词： I2 adsorption,cuprous halide clusters,luminescence properties,heterometallic organic frameworks,trinuclear indium
更新于2025-09-04 15:30:14
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Columnar Iridium(III) Metallomesogens Based on Polycatenar Pyridyltetrazolate with Ambipolar Carrier Mobility Behavior
摘要： In this paper, we have designed and synthesized a series of liquid-crystalline iridium(III) complexes based on polycatenar 2,5-diphenylpyridine and pyridyltetrazolate derivatives. Iridium(III) complexes all display highly emissive behavior with photoluminescence quantum yields in the range of 0.45?0.66 and a maximum emission wavelength at ～563 nm. Hexagonal columnar mesophases of iridium(III) complexes can be obtained by changing the number and length of peripheral alkoxyl chains attached to a 2,5-diphenylpyridine ligand (main ligand) and a pyridyltetrazolate ligand (auxiliary ligand). Moreover, experimental results of the charge transport properties for these iridium(III) complexes, which were measured by the space charge limited-current method, exhibit ambipolar carrier mobility behavior. In particular, the liquid-crystalline iridium(III) complexes can self-organize into one-dimensional (1D) nanostructure after thermal annealing treatment in their liquid-crystalline phase. The devices based on liquid crystal ?lm display improved charge transport behavior compared with that of the devices based on polycrystalline ?lm, indicating 1D nanostructure is bene?cial to charge carrier injection and transportation.
更新于2025-09-04 15:30:14
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Confocal Fluorescence Microscopy and Kinetics of the Cr3+-Chromate Ion Oxidation Equilibria at the Solid Liquid Interface
摘要： Silica-borax pearl samples impregnated with 0.17 and 0.64% Cr3+ were characterized by specific surface area measurements, UV-Vis spectroscopy, energy-dispersive X-ray fluorescence and laser-scanning confocal microscopy. Pearl stability against oxidizing conditions was tested by adding samples to an aqueous hydrogen peroxide solution. The reaction was examined by UV-Vis spectroscopic measurements of the supernatant and laser-scanning confocal microscopy images of the substrate. Overall, hydrogen peroxide-induced Cr3+ to Cr6+ oxidation across the solid-liquid interface promoted solid matrix cleavage pearl degradation and concomitant formation of multiple scattering centers was observed. A dual-detection scheme was employed in the confocal microscopy measurements allowing us to separate scattering and absorptive contributions to the observed signals. The confocal microscopy images indicate that Cr3+ oxidation induced by hydrogen peroxide solutions occurs throughout the entire pearl sample and indicate that oxidation reactions induce leakage of chromate ion into aqueous solutions.
关键词： energy dispersive X-ray fluorescence,confocal fluorescence microscopy,chromium mobility,H2O2 oxidation equilibria,mass transfer phenomena,solid liquid interfaces
更新于2025-09-04 15:30:14
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Simulating Fluorescence Detected Two-Dimensional Electronic Spectroscopy of Multi-Chromophoric Systems
摘要： We present a theory for modeling fluorescence detected two-dimensional electronic spectroscopy of multichromophoric systems. The theory is tested by comparison of the predicted spectra of the light-harvesting complex LH2 with experimental data. A qualitative explanation of the strong cross-peaks as compared to conventional two-dimensional electronic spectra is given. The strong cross-peaks are attributed to the clean ground state signal that is revealed when the annihilation of exciton pairs created on the same LH2 complex cancels oppositely-signed signals from the doubly-excited state. This annihilation process occurs much faster than the non-radiative relaxation. Furthermore, the lineshape difference is attributed to slow dynamics, exciton delocalization within the bands and intraband exciton-exciton annihilation. This is in line with existing theories presented for model systems. We further propose the use of time-resolved fluorescence detected two-dimensional spectroscopy to study state resolved exciton-exciton annihilation.
关键词： fluorescence detected two-dimensional electronic spectroscopy,multichromophoric systems,light-harvesting complex LH2,exciton-exciton annihilation,time-resolved fluorescence detected two-dimensional spectroscopy
更新于2025-09-04 15:30:14
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On the Fluorescent, Steric and Electronic Factors Affecting the Detection of Metallic Ions Using an Imidazolyl-Phenolic Derived Fluorescent Probe
摘要： The imidazolyl-phenolic probe used at the present study has its photophysic properties regulated by a tautomeric equilibrium. After the absorption of a photon, an excited state intramolecular proton transfer process generates a ketonic species, responsible for the 440 nm emission (in CH3CN/H2O, 95:5, v/v). Addition of Cu2+, Al3+, Cr3+ and Fe3+ suppresses emission through a combination of dynamic and static-like quenching, as indicated by Stern-Volmer plots, with a higher sensitivity for Cu2+ (KSV = 1.90 × 105 and 2.40 × 104 L mol–1, respectively, for Cu2+ and Fe3+). The trivalent ions led to the formation of a locked-enol tautomer that emits at shorter wavelengths; this coordinated compound is also quenched at metallic ions concentrations above 20 μmol L–1, due to a collisional process. When compared to another imidazolyl-phenolic probe, experimental and simulated data revealed that fluorescent, steric and electronic effects regulate their sensitivity towards the ions.
关键词： iron(III),copper(II),fluorescent sensor,ESIPT,tautomerization
更新于2025-09-04 15:30:14
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Is Vibrational Coherence a Byproduct of Singlet Exciton Fission?
摘要： A phenomenological wavefunction-based model of vibrationally coherent absorption modulation is proposed and applied to reproduce the triplet-triplet absorption spectra of bis-triisopropylsilylethynyl (TIPS)-pentacene, with the objective of testing whether the singlet fission process in that system spontaneously generates coherent vibrational packets, as recently suggested for TIPS-tetracene. The model is parametrized by a complete set of Franck-Condon parameters obtained from methodologically consistent DFT calculations for all relevant normal modes in all relevant electronic states. The results strongly depend on inhomogeneous broadening of absorption bands, which is explicitly included. They very well agree with the recently published experimental coherence spectra of the pertinent system, validating our underlying principal assumption that the singlet fission process, which generates the observed triplet states, is neutral with respect to vibrational coherences. Experimental confirmation of this interpretational posit demonstrates that in the pentacene derivative, apparently in contrast to the case of its tetracene analogue, fission is not a source of vibrational coherence. Our finding suggests that although the singlet fission process may possibly in individual cases induce vibrational coherence, this feature is not a constitutive characteristic of the fission phenomenon.
关键词： DFT calculations,singlet exciton fission,Franck-Condon parameters,TIPS-pentacene,vibrational coherence
更新于2025-09-04 15:30:14
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A study of the impact of VLC on the quality of lighting and display – EPSRC
摘要： Dr Wasiu Popoola of the University of Edinburgh talks about his research into visible light communication and shares the results of his latest work examining the underutilised optical spectrum as a potential pathway to wirelessly connect devices. The research investigates the impacts of visible light communication (VLC) on the fundamental properties of energy efficiency, light quality and life expectancy of a light-emitting diode (LED) that is primarily designed for lighting or display. It aims to deliver the required approach for optimising VLC and safeguard the LED’s reliability, durability and emitted light quality.
关键词： light quality,LED,VLC,energy efficiency,visible light communication,life expectancy
更新于2025-09-04 15:30:14
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VALIDATION STUDY OF STEROIDAL DRUGS (DEXAMETHASONE AND BETAMETHASONE) BY U.V. SPECTROPHOTOMETRIC METHOD
摘要： Objective: The present investigation involves development and validation of ultraviolet (UV) spectroscopic method for estimation of dexamethasone and betamethasone in a pharmaceutical dosage as per International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. Method: Betamethasone and dexamethasone were dissolved in 50 mL Methanol: water (1:2) and 50 mL distilled water, respectively. The method was validated for accuracy, precision, linearity, ruggedness, and robustness to check its consistency. Result: The λmax or the absorption maxima of both the drugs was found to be 241 nm. A linear response was observed in the range of 10–20 μg/mL. Conclusion: The method could be applied for the analysis of marketed tablets and also can be used for the routine analysis of dexamethasone and betamethasone in bulk formulations using UV method. It is suitable for the intended purpose especially in forensic science laboratories and other laboratories involved in the pharmaceutical analysis.
关键词： Accuracy,Method validation,Betamethasone,Precision,Dexamethasone,Ultraviolet spectroscopy
更新于2025-09-04 15:30:14