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Synthesis of Al-MCM-41@Ag/TiO <sub/>2</sub> Nanocomposite and Its Photocatalytic Activity for Degradation of Dibenzothiophene
摘要： Mesoporous Al-MCM-41@Ag/TiO2 nanocomposites were synthesized successfully by combining the sol-gel method and hydrothermal treatment, using titanium isopropoxide (TTIP), AgNO3, and Vietnamese bentonite as precursors of Ti, Ag, and Si, respectively. The synthesized materials were well characterized by X-ray powder di?raction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption-desorption isotherm measurements, energy dispersive X-ray spectroscopy (EDX), UV-visible di?use re?ectance spectroscopy (UV-Vis/DRS), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity was evaluated by the photodegradation of dibenzothiophene (DBT) under both UV and visible light irradiation. MCM-41@Ag/TiO2 catalyst exhibited high catalytic activity for the oxidative desulfurization (ODS) of DBT reaching almost 100% conversions at 50°C after 2 h under UV and visible light irradiations. The signi?cant enhanced degradation of DBT over Al-MCM-41@Ag/TiO2 might be due to the synergy e?ects of high surface area of MCM-41, well-distributed TiO2 anatase, and reduced electron-hole recombination rates due to the dispersion of Ag nanoparticles.
关键词： photocatalytic activity,Al-MCM-41@Ag/TiO2,dibenzothiophene,visible light irradiation,oxidative desulfurization
更新于2025-09-04 15:30:14
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mpg-C <sub/>3</sub> N <sub/>4</sub> /Ag <sub/>2</sub> O Nanocomposites Photocatalysts with Enhanced Visible-Light Photocatalytic Performance
摘要： To study the photocatalytic activity under visible light irradiation, a series of mesoporous graphitic carbon nitride (mpg-C3N4)/Ag2O photocatalysts were synthesized. The as-prepared photocatalysts were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 adsorption Brunauer-Emmett-Teller method (N2-BET), Fourier transform infrared spectroscopy (FT-IR), UV-vis diffuse reflectance spectra (DRS), and photoluminescence spectra (PL) methods to determine their phase structure, purity, morphology, spectroscopic and photoluminescence emission performance, respectively. Photocatalytic degradation of methyl orange (MO) aqueous solution under visible-light irradiation indicated that the mpg-C3N4/Ag2O-50 nanocomposite exhibited the best activity. The degradation rate of MO reached to 90.8% in 120 min onto the mpg-C3N4/Ag2O-50 nanocomposite, and as compared with the pure mpg-C3N4 and Ag2O samples, the photocatalytic activity of the mpg-C3N4/Ag2O-50 nanocomposite was greatly enhanced. The enhancement of photocatalytic activity was mainly ascribed to the enhanced visible-light absorption ability and the formation of p–n heterojunctions between counterparts of the nanocomposites, which promoted the generation and separation of charge carriers.
关键词： mpg-C3N4/Ag2O,MO Degradation,Photocatalytic Activity,Visible-Light Photocatalysis,p–n Heterojunctions
更新于2025-09-04 15:30:14
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Preparation of Nano Spinel Doped TiO <sub/>2</sub> and Its Photocatalytic Activity Evaluation Under Visible Light Irradiation
摘要： Nano MgFe–TiO2 photocatalyst was prepared by mixing nanoscale spinel compounds such as magnesium ferrite (MgFe) and TiO2. The cations produced by MgFe are affected by various influencing factors such as calcination temperature, precursor, and mass ratio of Mg and Fe. This study is to evaluate the photocatalytic efficiency of nano MgFe-doped TiO2 under visible light according to the composition ratio of Mg, Fe and TiO2. With an increase the percentage of doping (i.e., Mg and Fe) over TiO2, the band gap between conduction band and valance band decreases, therefore showing better photocatalytic activity in visible light. Also as percentage of doping over TiO2 increases, surface area of the catalyst also increases subsequently resulting in an increase in the adsorption capacity.
关键词： Visible Light,Spinel Compound,Magnesium Ferrite,Photocatalysis,TiO2
更新于2025-09-04 15:30:14
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Macular Pigment and Visual Performance in Low-Light Conditions
摘要： By reducing rod intrusion and improving efficiency of neural signaling throughout the visual system, macular pigment (MP) could improve many aspects of visual performance in low-light level conditions. Our study examined this possibility for a variety of visual performance parameters, including spatial resolution, dark adaptation kinetics, and color detection.
关键词： light/dark adaptation,macular pigment,lutein,visual acuity,visual performance
更新于2025-09-04 15:30:14
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Heterochromatic Flicker Photometry for Objective Lens Density Quantification
摘要： PURPOSE. Although several methods have been proposed to evaluate lens transmittance, to date there is no consensual in vivo approach in clinical practice. The aim of this study was to compare ocular lens density and transmittance measurements obtained by an improved psychophysical scotopic heterochromatic flicker photometry (sHFP) technique to the results obtained by three other measures: a psychophysical threshold technique, a Scheimpflug imaging technique, and a clinical assessment using a validated subjective scale. METHODS. Forty-three subjects (18 young, 9 middle aged, and 16 older) were included in the study. Individual lens densities were measured and transmittance curves were derived from sHFP indexes. Ocular lens densities were compared across methods by using linear regression analysis. RESULTS. The four approaches showed a quadratic increase in lens opacification with age. The sHFP technique revealed that transmittance decreased with age over the entire visual spectrum. This decrease was particularly pronounced between young and older participants in the short (53.03% decrease in the 400–500 nm range) wavelength regions of the light spectrum. Lens density derived from sHFP highly correlated with the values obtained with the other approaches. Compared to other objective measures, sHFP also showed the lowest variability and the best fit with a quadratic trend (r2 ? 0.71) of lens density increase as a function of age. CONCLUSIONS. The sHFP technique offers a practical, reliable, and accurate method to measure lens density in vivo and predict lens transmittance over the visible spectrum. An accurate quantification of lens transmittance should be obtained in clinical practice, but also in research in visual and nonvisual photoreception.
关键词： non-image forming,circadian light,ocular media,psychophysics,heterochromatic flicker photometry,cataract,clinical,lens density,photoreception
更新于2025-09-04 15:30:14
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Intense regulated pulse light for the meibomian gland dysfunction
摘要： Purpose: To assess the effect of intense regulated pulse light (E-Eye; E-Swin, France) on the treatment of meibomian gland dysfunction. Setting: Health Sciences University, Ankara Numune Training and Research Hospital, Department of Ophthalmology. Methods: A total of 26 patients underwent intense pulsed light treatment (E-Eye; E-Swin), with homogeneously sequenced five light pulses delivered to one eye at 1, 15, and 45 days following baseline evaluation. At each visit, subjective clinical parameters (ocular surface disease index questionnaire and standard patient evaluation of eye dryness questionnaire) and objective clinical parameters (Schirmer I test scores, tear break-up times, Oxford grading, lid margin abnormality score, secretion quality and expressibility degree) were recorded. The subjective and objective parameters at Days 15 and 45 were compared with baseline values. Results: Patients underwent three sessions of intense pulsed light treatment. Schirmer test and tear break-up time improved significantly from baseline to Day (D) 45 (8.53 ± 4.31 mm vs 12.6 ± 3.14 mm, 4.53 ± 1.33 sn vs 11.07 ± 2.87 sn, p = 0.003 and p < 0.001). Ocular surface disease index and standard patient evaluation of eye dryness scores improved from baseline to D15 and baseline to D45 (all with p < 0.05). All the subjects reported reduced symptoms by D45. There were no cases of adverse ocular effects. There was no significant change in Oxford grading, lid margin abnormality score, secretion quality, and expressibility degree. Conclusions: Intense regulated pulse light seems a safe treatment procedure for meibomian gland dysfunction, improving tear film quality and reducing symptoms of dry eye.
关键词： intense regulated pulse light,meibomian gland disease,Dry eye
更新于2025-09-04 15:30:14
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Multifunctional Magnetic Bead-Based Dynamic Light Scattering Aptasensor with Rapid and Feasible Determination of Disease-Related Biomarkers
摘要： A simple and feasible sensing strategy based on target-induced aggregation of aptasensor-conjugated multifunctional magnetic beads was designed for sensitive detection of low-abundant proteins (carcinoembryonic antigen, CEA, used as an example), coupling with dynamic light scatting technique.
关键词： Aptasensor,Cancer markers,Magnetic beads,Dynamic light scattering
更新于2025-09-04 15:30:14
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Preparation of erythromycin imprinted polymer by metal-free visible-light–induced ATRP and its application in sensor
摘要： Erythromycin (ERY) molecular imprinted polymer was prepared on the surface of Au electrode modified with Ni and Au nanoclusters (MIP/AuNCs/Ni/Au) via metal-free visible-light–induced atom transfer radical polymerization, which was very easy, controllable, and environmentally benign. MIP/AuNCs/Ni/Au was examined by energy dispersive spectrometer (EDS), scanning electron microscope (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Further, MIP/AuNCs/Ni/Au was successfully used for the determination of ERY by differential pulse voltammetry (DPV). Under the optimal conditions, MIP/AuNCs/Ni/Au gave a linear correlation over the ERY concentration from 1.0 × 10?8 to 1.0 × 10?1 mg/L with the detection limit of 3.2 × 10?9 mg/L (S/N = 3). Comparing with the similar sensors, the larger linear range and lower detection limit indicated the promising prospect of this electrochemical sensor. Hence, this study was of great importance for the polymer-modified electrodes and the sensitive detection of ERY.
关键词： Molecular imprinted polymer (MIP),Metal-free visible-light–induced atom transfer radical polymerization (MVL ATRP),Erythromycin (ERY)
更新于2025-09-04 15:30:14
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Photocatalytic C(sp3)-H activation towards α-methylenation of ketones using MeOH as 1C source steering reagent
摘要： Unprecedented direct access to terminal enones via α-methylenation of aryl ketones to form C=C bond is achieved under visible-light conditions using methanol as one carbon source substrate and solvent as well. The reaction involves Cu@g-C3N4-catalysed in situ oxidation of methanol into formaldehyde followed by dehydrative cross aldol type reaction. Various aryl ketones react efficiently with MeOH, producing α,β-unsaturated carbonyl compounds only in 4-8 h at room temperature in excellent yield (84-97%). Operational simplicity, wide substrate scope, ambient reaction conditions, visible-light photocatalysis and novel application of MeOH as methylene donor substrate are the salient features making the envisaged protocol mild, efficient and green alternative to the existing methods for synthesis of such fine chemicals.
关键词： g-C3N4,1 C source,Ketone,Visible-light,Terminal enone
更新于2025-09-04 15:30:14
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Unusual Light-Tunable Thermoresponsive Behavior of OEGylated Homopolypeptide with Azobenzene and Thioether Spacers
摘要： OEGylated homopolypeptide (i.e., P(Azo-S-OEG7)) bearing azobenzene, thioether spacers, and oligo(ethylene glycol) OEG tails were prepared via a copper-mediated 1,3-dipolar cycloaddition. P(Azo-S-OEG7) showed an upper critical solution temperature (UCST)-type thermo-, light-, and oxidation-responsive in ethanol/water solvent mixtures. The UCST-type cloud point temperature (Tcp) decreased after UV irradiation and it increased after visible light irradiation due to the trans-cis isomerization of azobenzene moieties. P(Azo-S-OEG7) can be readily oxidized in the presence of H2O2, yielding P(Azo-SOX-OEG7) with sulfone or sulfoxide spacers. P(Azo-SOX-OEG7) showed an increase of UCST-type Tcp after UV irradiation and the Tcp decreased after visible light irradiation, which is an opposite trend to the UCST-type phase behavior of P(Azo-S-OEG7) as well as previous report. P(Azo-S-OEG7) showed poor water-solubility, yet it underwent H2O2 induced solution phase transition yielding P(Azo-SOX-OEG7) with lower critical solution temperature (LCST)-type phase behavior in water. The P(Azo-SOX-OEG7) aqueous solutions showed a decrease of LCST-type Tcp after UV irradiation and consequently Tcp decreased after visible light irradiation.
关键词： upper critical solution temperature,oxidation-responsive polymer,light-responsive polymer,polypeptide,lower critical solution temperature
更新于2025-09-04 15:30:14