40 results match your criteria: "Ilie Murgulescu Institute of Physical Chemistry of the Romanian Academy[Affiliation]"

A rapid and feasible approach was used to develop visible-light-driven-type Dion-Jacobson perovskites by the modification of the RbLaTaO host (RbLTO) with FeCl through the molten salt route. X-ray diffraction (XRD) characterization showed that FeCl-modified layered perovskite (e.g.

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The significance of HER-1 and CA 125 lies in their ability to guide cancer diagnosis, treatment, and monitoring, improving personalized care and enhancing prognostic accuracy. The utilization of HER-1 and CA 125 as screening biomarkers for the anticipation of early-stage cancer and monitoring cancer progression is expanding due to the invasive and costly nature of present techniques. In this study, a novel stochastic sensor was developed for the simultaneous determination of HER-1 and CA 125 in whole blood, saliva, and gastric tumor tissue samples using a fast, easy, inexpensive, and portable method.

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Fast, reliable methods for characterizing the micelle-to-gel transition in emerging Pluronic F127/polysaccharide materials are essential for tailoring their applications as in situ gelling delivery systems. This study describes a simple fluorimetric method based on the response to gelation of the molecular probe thioflavin T (ThT). The techniques employed are (second derivative) steady-state and synchronous fluorescence.

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Nanostructured oxides (SiO, TiO) were synthesized using the sol-gel method and modified with noble metal nanoparticles (Pt, Au) and ruthenium dye to enhance light harvesting and promote the photogeneration of reactive oxygen species, namely singlet oxygen (O) and hydroxyl radical (•OH). The resulting nanostructures were embedded in a transparent polyvinyl alcohol (PVA) hydrogel. Morphological and structural characterization of the bare and modified oxides was performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), UV-Vis spectroscopy, and X-ray photoelectron spectroscopy (XPS).

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In this study, the effect of gamma irradiation (10 kGy) on proteins extracted from animal hide, scales, and wool was evidenced by calorimetric (μDSC) and spectroscopic (IR, circular dichroism, and EPR) methods. Keratin was obtained from sheep wool, collagen and bovine gelatin from bovine hide, and fish gelatin from fish scales. The μDSC experiments evidenced that gamma irradiation influences the thermal stability of these proteins differently.

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A novel electrochemical platform for amaranth determination has been developed using a rapid, easy, inexpensive, and portable molecularly imprinted polymer technique. The MIP platform was fabricated by electropolymerizing melamine as monomer in the presence of amaranth as template on the surface of ZnO-MWCNT/SPCE. Then, amaranth was completely eluted, leaving imprinted cavities in the polymeric film that could effectively recognize amaranth in solution.

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ZnSe, ZnSe-TiO microspheres and nanostructured TiO obtained by hydrothermal and sol-gel methods were tested against ATCC 25923 and ATCC 4698 before and after lysozyme (Lys) loading. Morphological characterization of inorganic matrices and hybrid organic-inorganic complexes were performed by microscopy techniques (SEM, AFM and Dark Field Hyperspectral Microscopy). Light absorption properties of ZnSe, ZnSe-TiO and TiO powders were assessed by UV-visible spectroscopy and their ability to generate reactive oxygen species (•OH and O) under visible light irradiation was investigated.

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Article Synopsis
  • This study investigates how the order of adding cross-linking agents affects the properties of interpenetrated polymer networks (IPNs) made from chitosan and alginate.
  • It utilizes three methods—rheology, IR spectroscopy, and electron paramagnetic resonance (EPR) spectroscopy—to analyze the physical and chemical characteristics of the polymer systems.
  • Findings indicate that the order of introducing cross-linkers impacts both the gel behavior and the dynamic structure of the network, with the alginate network significantly influencing the overall characteristics of the IPN systems.
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This work was devoted to the first multi-parametric unitary comparative analysis of a selection of sintered piezoceramic materials synthesised by solid-state reactions, aiming to delineate the most promising biocompatible piezoelectric material, to be further implemented into macro-porous ceramic scaffolds fabricated by 3D printing technologies. The piezoceramics under scrutiny were: KNbO, LiNbO, LiTaO, BaTiO, Zr-doped BaTiO, and the (BaCa)(TiZr)O solid solution (BCTZ). The XRD analysis revealed the high crystallinity of all sintered ceramics, while the best densification was achieved for the BaTiO-based materials via conventional sintering.

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One of the major clinical issues during the implantation procedure is the bacterial infections linked to biofilms. Due to their tissue localization and the type of bacteria involved, bacterial infections at implant sites are usually difficult to treat, which increases patient morbidity and even mortality. The difficulty of treating biofilm-associated infections and the emergence of multidrug-resistant bacteria are further challenges for the scientific community to develop novel biomaterials with excellent biocompatibility and antibacterial properties.

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A polymer-based carbon paste electrode was constructed by electropolymerized Alizarin Red S (ARS) film on the carbon paste electrode (CPE) surface. The electrochemical properties of poly-ARS/CPE were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Scanning electron microscopy (SEM) was utilized for electrode characterization.

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Three enantiomeric pairs consisting of copper(II) complexes with tridentate Schiff bases have been synthesized for employing in biological assessments: 1∞[Cu(/-salmet)(HO)] (1-R/S·H2O), 1∞[Cu(/-3-HOMe-5-Me-salmet)] (2-R/S), and 1∞[Cu(/-3-MeO-salmet)] (3-R/S) (where /-salmetH, /-3-HOMe-5-Me-salmetH, and /-3-MeO-salmetH result from the condensation of /-methionine with salicylaldehyde, 2-hydroxy-3-(hydroxymethyl)-5-methylbenzaldehyde, and 3-methoxy-salicylaldehyde, respectively, in a 1 : 1 molar ratio). The crystal structures of 1-R·H2O and 2-R/S are reported. Moreover, the 1-R/S·H2O enantiomers have been subjected to a single-crystal-to-single-crystal (SC-SC) transformation by heating at 160 °C to afford their dehydrated forms, 1∞[Cu(/-salmet)] (1-R/S), whose structures have also been crystallographically determined.

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This work presents the synthesis of nanostructured TiO modified with noble metal nanoparticles (Au, Ag) and lysozyme and coated on titanium foil. Moreover, the specific structural and functional properties of the resulting inorganic and hybrid materials were explored. The purpose of this study was to identify the key parameters for developing engineered coatings on titanium foil appropriate for efficient dental implants with intrinsic antibacterial activity.

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The deep eutectic solvent (DES)-based biocatalysis of l-menthol acylation was designed for the production of fatty acid l-menthyl ester (FME) using fatty acid methyl ester (FAME). The biocatalytic reaction was assisted by a lipase enzyme in the DES reaction medium. ւՒ-menthol and fatty acids (e.

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This study presents the preparation of hybrid nanofiltration membranes based on poly(1,4-phenylene ether ether sulfone), polyacrylonitrile, poly(vinyl pyrrolidone), and SBA-15 mesoporous silica. Laser treatment of polymeric solutions to enhance the hydrophilicity and performance of membranes was investigated. The membranes' structure was characterized using scanning electron (SEM) and atomic force (AFM) microscopy and contact angle measurements.

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In this work, we explored by means of electron paramagnetic resonance (EPR) spectroscopy the accessibility of a series of spin probes, covering a scale of molecular weights in the range of 200-60,000 Da, in a variety of hydrogels: covalent network, ionotropic, interpenetrating polymer network (IPN) and semi-IPN. The covalent gel network consists of polyethylene or polypropylene chains linked isocyanate groups with cyclodextrin, and the ionotropic gel is generated by alginate in the presence of Ca ions, whereas semi-IPN and IPN gel networks are generated in a solution of alginate and chitosan by adding crosslinking agents, Ca for alginate and glutaraldehyde for chitosan. It was observed that the size of the diffusing species determines the ability of the gel to uptake them.

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A novel electrochemical sensor based on the modification of carbon paste electrode with an ionic liquid (1-butyl-2,3-dimethylimidazolium tetrafluoroborate) and AuTiO/GO composite (IL/AuTiO/GO/CPE) was developed for rapid and sensitive determination of tartrazine by differential pulse voltammetry. Under the optimum experimental conditions, the peak current was linear to concentration of tartrazine in the ranges of 1-400 µmol L and 400-1000 µmol L, with sensitivities of 0.008 µA µmol L and 0.

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Article Synopsis
  • Biocompatible gel microemulsions using essential oils like cinnamon, oregano, and clove have been developed to improve the skin absorption and effectiveness of the antifungal drug fluconazole.
  • The study focused on enhancing the adhesion of these microemulsions by incorporating chitosan, a biopolymer with antifungal properties, and analyzed how different formulation components affected their overall performance.
  • Results indicated that specific formulations significantly improved drug release and antifungal activity, showcasing these microemulsions as effective delivery systems for topical fluconazole treatments.
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Article Synopsis
  • Riboflavin, when exposed to UVA radiation, generates reactive oxygen species (ROS), which can alter biological systems and be utilized in treating ocular and dermal diseases.
  • In corneal cross-linking (CXL) for keratoconus, riboflavin and UVA work together to promote collagen fibril formation, but polysaccharides like dextran are added to mitigate the harmful effects of ROS.
  • The study investigates how riboflavin affects collagen fibril formation using methods such as microcalorimetry, rheology, and STEM imaging, with evidence of ROS production in collagen, hyaluronic acid, and riboflavin solutions from spin trapping experiments.
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The nanofiltration composite membranes were obtained by incorporation of KIT-6 ordered mesoporous silica, before and after its functionalization with amine groups, into polyphenylene-ether-ether-sulfone (PPEES) matrix. The incorporation of silica nanoparticles into PPEES polymer matrix was evidenced by FTIR and UV-VIS spectroscopy. SEM images of the membranes cross-section and their surface topology, evidenced by AFM, showed a low effect of KIT-6 silica nanoparticles loading and functionalization.

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The environmental monitoring of Ni is targeted at a threshold limit value of 0.34 μM, as set by the World Health Organization. This sensitivity target can usually only be met by time-consuming and expensive laboratory measurements.

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In this work, (BaSr) (TiCo) O perovskite nanostructured material, denoted subsequently as Co-doped BaSrTiO, was synthesized in a one-step process in hydrothermal conditions. The obtained powder was heat-treated at 800 °C and 1000 °C, respectively, in order to study nanostructured powder behavior during thermal treatment. The Co-doped BaSrTiO powder was pressed into pellets of 5.

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Electron paramagnetic resonance (EPR) spectroscopy is the main tool for evidencing the formation of inclusion complexes of cyclodextrins with paramagnetic guests, based on changes in the EPR parameters. In-depth information on complexation can only be obtained by a combination of physico-chemical methods. Herein we report on the interaction of three TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) type radicals with cyclodextrins by collecting and analysing data provided experimentally by EPR and circular dichroism spectroscopies and theoretically by density functional theory and molecular docking.

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Solvatochromic characteristics of dansyl molecular probes bearing alkyl diamine chains.

Spectrochim Acta A Mol Biomol Spectrosc

August 2020

"Ilie Murgulescu" Institute of Physical Chemistry of the Romanian Academy, 202 Splaiul Independentei, Bucharest 060021, Romania. Electronic address:

A series of dansyl-based fluorescent probes bearing linear alkyl-1,n-diamine chains of different length (DA, n = 2-8, 10, 12) was characterized in terms of the absorptive and emissive features in solvents of different polarity and hydrogen bond donor/hydrogen bond acceptor character. The probes show solvent-dependent absorption, a feature that is uncommon among dansyl derivatives. The dual emission of DA probes is strong in non-aqueous solvents and is influenced by the chain length and interactions with the solvent.

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The formation and growth of gold nanoparticles (AuNPs) were investigated in pH 7 buffer solution of bovine serum albumin (BSA) at room temperature. The processes were monitored by UV-Vis, circular dichroism, Raman and electron paramagnetic resonance (EPR) spectroscopies. TEM microscopy and dynamic light scattering (DLS) measurements were used to evidence changes in particle size during nanoparticle formation and growth.

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