6 research outputs found

    Preliminary archaeometric investigation on Middle Neolithic siliceous tools from Limba-Oarda de Jos (Transylvania, Romania)

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    The present archaeometric study focuses on a set of archaeological siliceous lithic tools that are assigned to the early Vinča culture period (Vinča A and Vinča B1). They were found in several pit-houses at Limba-Oarda de Jos (SW Transylvania, Romania), an open settlement that has been dated to 5,405-5,310 cal. BCE, a period in the Middle Neolithic. A total of 322 retouched tools and débitage pieces were typologically and macroscopically investigated. From these, 20 pieces were analyzed by polarized light optical microscopy (OM) and 10 pieces were analyzed by Fourier-transform infrared spectroscopy (FTIR) in order to identify compositional characteristics, define the petrographic type, and establish the spectral fingerprint of each material. Four petrographic types were discriminated: radiolarite, chert, fossiliferous chert, and siliceous limestone. Mineralogically, the tools primarily consist of a mass of microquartz and fibrous microquartz (called also ‘chalcedony’) associated with radiolarians remnants (in radiolarites); fossil shell fragments (in the fossiliferous chert); and limestone components, such as ooliths and pellets (in the siliceous limestone). All samples show distinct FTIR bands, most of which are assigned to microquartz, quartz, and fibrous microquartz. The deconvolution of the FTIR spectra in the 950-1300 cm-1 domain reveals the contribution of several other phases, such as calcite and clay minerals. The results support the assumption that the tools made of chert, fossiliferous chert, and siliceous limestone were produced at the site from nodules that probably originated from the Upper Jurassic chert-bearing limestone that crops out nearby in the Trascău Mts. The tools made of radiolarite were most likely brought to the site as finished products from the Trascău Mts

    Arany nanorészecskéket tartalmazó bioaktív üveg – biopolimér kompozítok előállítása, jellemzése és alkalmazhatósága: Synthesis, characterization and applicability of bioactive glass – biopolymer composites with gold nanoparticles

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    Considering that the median age of our population is increasing, bone disorders or skin regeneration problems are of significant concern. The bioactive glass-biopolymer composites are materials with real potential to be used in tissue engineering. It is well-known, that the bioactive glasses (BG) can lead the promotion of growth of granulation tissue. The gold nanoparticles (AuNPs; ~20 nm) can induced the acceleration of wound healing including tissue regeneration, connective tissue regeneration and angiogenesis. It was demonstrated that the AuNPs in the sol-gel derived glass structure retain their properties. Alginate-pullulan (Alg-Pll) composites have good bioactivity and in vivo qualities in terms of bone regeneration. The goal of this study was to obtain the functional composites for future tissue engineering applications using BG with AuNPs introduced in Alg-Pll composites. After structural and morphological characterization of the composites, in vitro and in vivo bioactivity and biocompatibility were evaluated. The obtained results suggest that the obtained composites are materials for future soft tissue and bone engineering applications.  Kivonat A várható élettartam növekedésével egyre növekszik azon betegek száma, amelyek ortopédiai vagy bőr rekonstrukcióra szorulnak. A bioaktív üveg-biopolimer kompozitok potenciálisan alkalmazható anyagok a szövettani sebészetben. Ismert dolog, hogy a bioaktív üvegek (BG) elősegítik a granulációs szövetek növekedését. Az arany nanorészecskék (AuNPs; ~20 nm) gyorsítják a sebgyógyulást beleértve angiogenézist, a szövetek és kötőszövet regenerálódását. Tudjuk, hogy a szól-gél módszerrel előállított üveg szerkezetben bevitt AuNPs képes megőrizni ezen tulajdonságait. Az alginát-pullulán (kompozitok) remek bioaktivitásuknak köszönhetően aktívan részt vesznek az in vivo csont regenerálódásban. A tanulmány célja, hogy olyan funkcionális kompozitokat hozzunk létre, amelyek alkalmazhatók a szövettani sebészetben. Ehhez az Alg-Pll kompozitokban AuNPs tartalmazó BG vittünk be, majd szerkezeti és morfológiai jellemzéseket végeztünk. Ezt követtően az in vitro és in vivo bioaktivitás, valamint biokompatibilitást vizsgáltuk. A kapott eredmények azt sugallják, hogy az előállított kompozitok megfelelnek a lágyrész- és csonttechnikai alkalmazás elvárásainak

    Crystal Structure and Physicochemical Characterization of Ambazone Monohydrate, Anhydrous, and Acetate Salt Solvate

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    The crystal structures of the monohydrate and anhydrous forms of ambazone were determined by single-crystal X-ray diffraction (SC-XRD). Ambazone monohydrate is characterized by an infinite three-dimensional network involving the water molecules, whereas anhydrous ambazone forms a two-dimensional network via hydrogen bonds. The reversible transformation between the monohydrate and anhydrous forms of ambazone was evidenced by thermal analysis, temperature-dependent X-ray powder diffraction and accelerated stability at elevated temperature, and relative humidity (RH). Additionally, a novel ambazone acetate salt solvate form was obtained and its nature was elucidated by SC-XRD. Powder dissolution measurements revealed a substantial solubility and dissolution rate improvement of acetate salt solvated form in water and physiological media compared with ambazone forms. Also, the acetate salt solvate displayed good thermal and solution stability but it transformed to the monohydrate on storage at elevated temperature and RH. Our study shows that despite the requirement for controlled storage conditions, the acetate salt solvated form could be an alternative to ambazone when solubility and bioavailability improvement is critical for the clinical efficacy of the drug product
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