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Continuous In Vivo Monitoring of the Oxygen Concentration in Tissues
摘要： The kinetics of delayed fluorescence and phosphorescence of xanthene dyes in mouse tissues under the pulse-periodic excitation of molecules was studied in vivo and in vitro. The advantages of continuous monitoring of oxygen content in tissues by the kinetics of delayed fluorescence caused by singlet–triplet annihilation of singlet oxygen with triplet excitation of fluorophore are demonstrated. A method is proposed for determining the time of recovery of the concentration of oxygen consumed in tissues in vivo and in vitro during photodynamic processes.
关键词： delayed luminescence,singlet oxygen,tissues,xanthene dyes
更新于2025-09-23 15:22:29
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Application of Response Surface Methodology to Evaluate Photodynamic Inactivation Mediated by Eosin Y and 530 nm LED against Staphylococcus aureus
摘要： Photodynamic antimicrobial chemotherapy (PAC) is an efficient tool for inactivating microorganisms. This technique is a good approach to inactivate the foodborne microorganisms, which are responsible for one of the major public health concerns worldwide—the foodborne diseases. In this work, response surface methodology (RSM) was used to evaluate the interaction of Eosin Y (EOS) concentration and irradiation time on Staphylococcus aureus counts and a sequence of designed experiments to model the combined effect of each factor on the response. A second-order polynomial empirical model was developed to describe the relationship between EOS concentration and irradiation time. The results showed that the derived model could predict the combined influences of these factors on S. aureus counts. The agreement between predictions and experimental observations (R2 adj = 0.9159, p = 0.000034) was also observed. The significant terms in the model were the linear negative effect of photosensitizer (PS) concentration, followed by the linear negative effect of irradiation time, and the quadratic negative effect of PS concentration. The highest reductions in S. aureus counts were observed when applying a light dose of 9.98 J/cm2 (498 nM of EOS and 10 min. irradiation). The ability of the evaluated model to predict the photoinactivation of S. aureus was successfully validated. Therefore, the use of RSM combined with PAC is a promising approach to inactivate foodborne pathogens.
关键词： photodynamic inactivation,xanthene dye,foodborne pathogen,green LED light,mathematical model
更新于2025-09-23 15:19:57
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Xanthene Dye-Functionalized Conjugated Porous Polymers as Robust and Reusable Photocatalysts for Controlled Radical Polymerization
摘要： Photoinduced electron/energy transfer?reversible addition?fragmentation chain transfer (PET?RAFT) polymerization represents a versatile and highly e?cient method for polymerizations of wide-ranging monomer variances upon solar energy harvesting. Although signi?cant progress has been achieved, several drawbacks are still associated with existing photocatalysts, such as toxicity of transition metals, high cost, poor stability, and unavoidable puri?cation procedures because of the photobleaching e?ect, to name a few. Herein, 1,4-diethynylbenzene-linked xanthene dye-conjugated porous polymers (CPPs) have been established as potential heterogenous photocatalysts of PET?RAFT polymerization. With this two-dimensional planar architecture, we demonstrate dual-stimuli toggling of RAFT polymerization using two di?erent external physical manipulations: light “ON”/“OFF” and solution pH “LOW”/“HIGH”. In addition, these CPPs endowed radical polymerizations with various impressive features such as compatibility of diverse monomer formulations, unique oxygen tolerance, and ppm-level catalyst dosage. Demonstrations of chain extension and catalyst recycling further highlight the robustness and performance of this CPP catalyst. Through the study of structure?property relationship using the experimental analyses, we envisage that a series of xanthene dye-functionalized CPPs can be developed as visible light-absorbing organocatalysts rivaling transition-metal photocatalysts.
关键词： PET?RAFT polymerization,visible light-absorbing organocatalysts,xanthene dye-functionalized conjugated porous polymers,dual-stimuli toggling,heterogeneous photocatalysts
更新于2025-09-23 15:19:57
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Pulsed laser ablated zeolite nanoparticles: A novel nano‐catalyst for the synthesis of 1,8‐dioxo‐octahydroxanthene and <i>N</i> ‐aryl‐1,8‐dioxodecahydroacridine with molecular docking validation
摘要： There is an increasing interest in the synthesis of metal nanoparticles (NPs) from bulk metals using pulsed laser ablation in liquids (PLAL), as it offers an easy and simple synthesis route. In this work, zeolite NPs (molecular sieve 4A) were successfully synthesized by the PLAL technique, and characterized by X‐ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, field emission scanning electron microscopy, and high‐resolution transmission electron microscopy. Data obtained confirm the formation of the crystalline phase of zeolite. The synthesized catalyst (zeolite molecular sieve 4A) was used as an efficient and facile promotor for the synthesis of xanthene and acridine derivatives. Molecular docking of the synthesized compounds was validated using quinone reductase 2 (NQO2) and acridine orange as the ligand, with the synthesized molecules showing good drug–ligand interaction on the active site of NQO2, compared with that of acridine orange.
关键词： zeolite,acridine,xanthene,laser ablation,nanoparticles,dimedone
更新于2025-09-12 10:27:22
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Organosoluble and transparent cardo polyimides with high <i>T</i> <sub/>g</sub> derived from 9,9-bis(4-aminophenyl)xanthene
摘要： 9,9-Bis(4-aminophenyl)xanthene (BAPX) was prepared simply and effectively via one-pot, two-step procedure using xanthenone and aniline as main substrates. The monomer BAPX was reacted with six aromatic dianhydrides in N,N-dimethylacetamide (DMAc) to yield the corresponding polyimides (PIs) via the poly(amic acid) precursors and subsequent thermal or chemical imidization. The resulting PIs exhibited good thermal stability with glass transition temperatures of 308–348°C, initial decomposition temperatures of 470–510°C, 10% weight loss temperatures of 540–565°C, and char yields of 55–59% at 800°C in nitrogen, respectively. All polymers were amorphous and readily soluble in organic solvents such as N-methyl-2-pyrrolidone and DMAc. The PI films had tensile strengths of 71–92 MPa, tensile moduli of 1.91–2.35 GPa, and elongations at break of 5–13%. Meanwhile, these polymer films also had high optical transparency with a cutoff wavelength in the range of 367–415 nm, lower dielectric constants (3.02–3.34 at 10 MHz), and low water uptake of 0.30–0.52%.
关键词： Aromatic polyimide,9,9-bis(4-aminophenyl)xanthene,bulky pendent xanthene cardo group,thermal property,optical transparency,solubility
更新于2025-09-04 15:30:14
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Guiding the Design of Organic Photocatalyst for PET-RAFT Polymerization: Halogenated Xanthene Dyes
摘要： By examining structurally similar halogenated xanthene dyes, this study establishes a guiding principle for resolving structure?property?performance relationships in the photocontrolled PET-RAFT polymerization system (PET-RAFT: photoinduced electron/energy transfer?reversible addition?fragmentation chain transfer). We investigated the effect of the halogen substituents on the photophysical and electrochemical properties of the xanthene dyes acting as photocatalysts and their resultant effect on the performance of PET-RAFT polymerization. Consideration of the structure?property?performance relationships allowed design of a new xanthene photocatalyst, where its photocatalytic activity (oxygen tolerance and polymerization rate) was successfully optimized for PET-RAFT polymerization. We expect that this study will serve as a theoretical framework in broadly guiding the design of high performance photocatalysts for organic photocatalysis.
关键词： PET-RAFT polymerization,structure?property?performance relationships,oxygen tolerance,photocatalysts,halogenated xanthene dyes
更新于2025-09-04 15:30:14