Publications by authors named "Vourlias G"

A novel nanocomposite consisting of FeO-loaded tin oxyhydroxy-chloride is demonstrated as an efficient adsorbent for the removal of hexavalent chromium in compliance to the new drinking water regulation. This study introduces a continuous-flow production of the nanocomposite through the separate synthesis of (i) 40 nm FeO nanoparticles and (ii) multilayered spherical arrangements of a tin hydroxy-chloride identified as abhurite, before the application of a wet-blending process. The homogeneous distribution of FeO nanoparticles on the abhurite's morphology, features nanocomposite with magnetic response whereas the 10 % loaded nanocomposite preserves a Cr(VI) uptake capacity of 7.

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Tin oxide nanoparticles optimized to capture low concentrations of hexavalent chromium from water were developed through a facile, scalable, and low-cost one-step solar vapor deposition methodology. Considering the preservation of high electron donation capacity as the key to support the reduction of mobile Cr(VI) into insoluble forms, the growth of SnO nanoparticles was favored by the co-evaporation of SnO with Fe powders at various mass ratios. Characterization techniques indicated that the percentage and the stability of SnO is proportional to the Fe content in the target with a requirement of at least 50% wt to inhibit the formation of a passive SnO surface layer.

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Maximizing the safe removal of hexavalent chromium (Cr) from waste streams is an increasing demand due to the environmental, economic and health benefits. The integrated adsorption and bio-reduction method can be applied for the elimination of the highly toxic Cr and its detoxification. This work describes a synthetic method for achieving the best chemical composition of spherical and flower-like manganese ferrite (MnFeO) nanostructures (NS) for Cr adsorption.

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Magnetic particle hyperthermia (MPH) is a promising method for cancer treatment using magnetic nanoparticles (MNPs), which are subjected to an alternating magnetic field for local heating to the therapeutic range of 41-45 °C. In this window, the malignant regions (i.e.

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Article Synopsis
  • Silica-based ceramics doped with calcium and magnesium, particularly akermanite, show promise for bone regeneration due to their beneficial properties like controllable biodegradation and strong mechanical characteristics.
  • The incorporation of synthetic biopolymers (PLGA) and silica-based nanoparticles (NPs) containing essential elements (e.g., copper and strontium) enhances the mechanical performance and degradation rates of these ceramic scaffolds while incorporating an antibiotic (Moxifloxacin) for antimicrobial benefits.
  • The study demonstrated that these composite scaffolds exhibited improved strength, hemocompatibility, and sustained drug release, making them effective candidates for applications in bone regeneration.
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Poly(ethylene 2,5-furandicarboxylate) (PEF) nanocomposites reinforced with Graphene nanoplatelets (GNPs) and Carbon nanotubes (CNTs) were in situ synthesized in this work. PEF is a biobased polyester with physical properties and is the sustainable counterpart of Polyethylene Terephthalate (PET). Its low crystallizability affects the processing of the material, limiting its use to packaging, films, and textile applications.

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Recent developments in nanomagnetism and spintronics have enabled the use of ultrafast spin physics for terahertz (THz) emission. Spintronic THz emitters, consisting of ferromagnetic (FM)/non-magnetic (NM) thin film heterostructures, have demonstrated impressive properties for the use in THz spectroscopy and have great potential in scientific and industrial applications. In this work, we focus on the impact of the FM/NM interface on the THz emission by investigating Fe/Pt bilayers with engineered interfaces.

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Engineered electrospun membranes have emerged as promising materials in guided tissue regeneration, as they provide an appropriate framework for the formation of new functional periodontal tissues. The development of multifunctional local drug delivery systems with sustained release of drugs for prolonged infection control can be used in periodontal surgical interventions to simultaneously prohibit epithelium downgrowth and ensure proper healing and regeneration of damaged periodontal tissues. The aim of the present study was the fabrication of novel composite membranes from PLGA/moxifloxacin-loaded mesoporous nanocarriers through electrospinning and the evaluation of their drug release profiles.

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We have explored the impact of elevated growth and annealing temperatures on the local interfacial structure of thin Fe(12 nm)/Pt(10 nm) spintronic bilayers, epitaxially grown on MgO (100), and their correlation to magnetization reversal and dynamics. Electron-beam evaporation growth and subsequent annealing at 450 °C causes significant roughening of the MgO/Fe interface with irregular steps and multilevel (100) MgO surface terraces. Consequently, threading dislocations emerging at the step edges propagated in the Fe layer and terminated at the Fe/Pt interface, which appears pitted with pits 1.

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The present study focuses on the investigation of the successive pictorial phases of the wall painting which survives on the missing eastern part of the magnificent mosaic composition in the interior of Rotunda, Thessaloniki, Greece. Rotunda, a circular domed monumental building, was constructed in the early 4th century AD and it is included in the UNESCO World Heritage List. Characterization analysis was performed by means of microscopic, spectroscopic and crystallographic techniques, in order to identify the technological features of the wall painting and the materials used, to document the initial Byzantine pictorial phase -known from the archaeological research- along with the overpaintings attributed to the 19th and 20th centuries.

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Interim restorations are essential in fixed prosthodontics as they provide temporary protection of teeth before the insertion of the permanent restoration. Poly(methyl methacrylate) (PMMA) is widely used in the fabrication of interim-fixed restorations as it is a biocompatible material with a lot of convenient properties. However, it exhibits low impact and tensile strength and therefore it is necessary to be reinforced.

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A series of high-density polyethylene nanocomposites filled with different diameter sizes (5, 15, and 25 μm) of graphene nanoplatelets at various amounts (0.5-5 wt.%) are prepared by the melt-mixing method.

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IrO/Ir(Ni) film electrodes of variable Ni content have been prepared via a galvanic replacement method, whereby surface layers of pre-deposited Ni are replaced by Ir, followed by electrochemical anodization. Electrodeposition of Ni on a glassy carbon electrode support has been carried out at constant potential and the charge of electrodeposited Ni controlled so as to investigate the effect of precursor Ni layer thickness on the electrocatalytic activity of the corresponding IrO/Ir(Ni)/GC electrodes for the oxygen evolution reaction (OER). After their preparation, these electrodes were characterized by microscopic (SEM) and spectroscopic (EDS, XPS) techniques, revealing the formation of Ir deposits on the Ni support and a thin IrO layer on their surfaces.

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This study is focused on the preparation of metal (Cu, Zn) nanopowders by an electrochemical reduction/precipitation procedure, which provides the primary components for the development of CuZn alloy metallic foams. This well-controlledmethod allows straight forward control of the reaction parameters and the restriction of oxidation effects, while resulting in stable and small grain size metal nanopowders. Whether precipitation of Cu and Zn is held separately or in alternating deposition mode, the characteristics of synthesized nanopowders assist easier mixing, alloying and realization of metallic foams suitable for water treatment applications.

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Article Synopsis
  • * Copper oxide nanoparticles (CuO NPs) demonstrated stronger antibacterial properties than cuprous-ferric delafossite (CuFeO NPs), but CuFeO NPs exhibited lower genotoxicity and better biocompatibility.
  • * CuFeO NPs also performed better in protecting against protein denaturation, suggesting potential for superior anti-inflammatory effects compared to CuO NPs and similar to standard medications like acetylsalicylic acid.
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In the present work, the stabilization/solidification of a Cr-rich ash obtained from the anoxic incineration of tannery hazardous wastes was studied. Chromium in the starting waste was exclusively in amorphous form and in trivalent state. The waste was embedded in fly ash-based cementitious material matrices.

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The fabrication, by an all electrochemical process, of porous Si/ZnO nanostructures with engineered structural defects, leading to strong and broadband deep level emission from ZnO, is presented. Such nanostructures are fabricated by a combination of metal-assisted chemical etching of Si and direct current electrodeposition of ZnO. It makes the whole fabrication process low-cost, compatible with Complementary Metal-Oxide Semiconductor technology, scalable and easily industrialised.

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Improving the charge carrier mobility of solution-processable organic semiconductors is critical for the development of advanced organic thin-film transistors and their application in the emerging sector of printed electronics. Here, a simple method is reported for enhancing the hole mobility in a wide range of organic semiconductors, including small-molecules, polymers, and small-molecule:polymer blends, with the latter systems exhibiting the highest mobility. The method is simple and relies on admixing of the molecular Lewis acid B(CF) in the semiconductor formulation prior to solution deposition.

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The mineralogy, morphology, and chemical composition of magnetic fractions separated from fly ashes (FAs) originating from Greek lignite-burning power plants was investigated. The oral bioaccessibility of potentially harmful elements (PHEs) from the fly ash magnetic fractions (FAMFs) was also assessed using in vitro gastrointestinal extraction (BARGE Unified Bioaccessibility Method, UBM). The FAMFs isolated were in the range 4.

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The vitrification process was applied for the stabilization and solidification of a rich in chromium ash that was the by-product of incineration of tannery sludge. Six different batch compositions were produced, based on silica as the glass former and sodium and calcium oxides as flux agents. As-vitrified products (monoliths) were either composed of silicate matrices with separated from the melt Eskolaite (CrO) crystallites or were homogeneous glasses (in one case).

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There is a growing field of research into the physicochemical properties of metal oxide nanoparticles (NPs) and their potential use against tumor formation, development and progression. Coated NPs with biocompatible surfactants can be incorporated into the natural metabolic pathway of the body and specifically favor delivery to the targeted cancerous cells versus normal cells. Polyethylene glycol (PEG) is an FDA approved, biocompatible synthetic polymer and PEGylated NPs are regarded as "stealth" nanoparticles, which are not recognized by the immune system.

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A ternary organic semiconducting blend composed of a small-molecule, a conjugated polymer, and a molecular p-dopant is developed and used in solution-processed organic transistors with hole mobility exceeding 13 cm(2) V(-1) s(-1) (see the Figure). It is shown that key to this development is the incorporation of the p-dopant and the formation of a vertically phase-separated film microstructure.

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Magnetic nanoparticles (MNPs) can play a distinct role in magnetic drug delivery via their distribution to the targeted area. The preparation of such MNPs is a challenging multiplex task that requires the optimization of size, magnetic, and surface properties for the achievement of desirable target selectivity, along with the sustained drug release as a prerequisite. In that context, CoFe2O4 MNPs with a small size of ∼7 nm and moderate saturation magnetization of ∼60 emu g(-1) were solvothermally synthesized in the presence of octadecylamine (ODA) with a view to investigate the functionalization route effect on the drug release.

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Perhaps the simplest method for creating metal nanoparticles on a substrate is by driving their self-assembly with the thermal annealing of a thin metal film. By properly tuning the annealing parameters one hopes to discover a recipe that allows the pre-determined design of the NP arrangement. However, thermal treatment is known for detrimental effects and is not really the manufacturer's route of choice when it comes to large-scale applications.

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