Gypsum twins are frequently observed in nature, triggered by a wide array of impurities that are present in their depositional environments and that may exert a critical role in the selection of different twin laws. Identifying the impurities able to promote the selection of specific twin laws has relevance for geological studies aimed at interpreting the gypsum depositional environments in ancient and modern deposits. Here, the effect of calcium carbonate (CaCO) on gypsum (CaSO·2HO) growth morphology has been investigated by performing temperature-controlled laboratory experiments with and without the addition of carbonate ions.
View Article and Find Full Text PDF2D and 3D epitaxies of the main {010}, {001} and {100} forms of deposited bassanite (CaSO·0.5HO) on {10.4} calcite (CaCO) as a substrate are described to provide a theoretical crystallographic background for the replacement of calcite by bassanite both in nature and in the laboratory and by weathering linked to cultural heritage.
View Article and Find Full Text PDFPhys Chem Chem Phys
September 2021
In this study the absorption of glycine, α-alanine and β-alanine amino acids into the pores of the synthetic zeolite Na-mordenite was investigated with the aim of: (i) evaluating the effectiveness of the MOR framework type in amino acid adsorption ( vapor and aqueous loading); (ii) understanding the host-guest and guest-guest interactions to possibly design a tailor made material and a loading procedure able to maximize the amino acid adsorption; (iii) studying the effect of pressure on the adsorbed amino acids such as, for instance, possible amino acid condensation. The structural characterization, carried out with the combination of diffractometric and infrared spectroscopy analyses, shows that MOR can adsorb amino acids, which are found both in protonated/deprotonated (possibly also generating zwitterions) form. Vapor loading is ineffective for α-alanine, while it is effective in β-alanine and glycine adsorption, even if using different loading degrees.
View Article and Find Full Text PDFSonodynamic therapy (SDT) is an innovative anticancer approach, based on the excitation of a given molecule (usually a porphyrin) by inertial acoustic cavitation that leads to cell death the production of reactive oxygen species (ROS). This study aims to prepare and characterize nanosystems based on porphyrin grafted carbon nanotubes (SWCNTs), to understand some aspects of the mechanisms behind the SDT phenomenon. Three different porphyrins have been covalently linked to SWCNTs using either Diels-Alder or 1,3-dipolar cycloadditions.
View Article and Find Full Text PDFThe increase in the amount of carbon dioxide (CO) emissions related to many anthropic activities is a persistent and growing problem. During the last years, many solutions have been set out, none of them being the ultimate one. Investigators agree on the need of a synergic approach to the problem, in terms of many complementary methods of sequestration that, combined with the reduction of production, will be able to decrease the concentration of the CO in the atmosphere.
View Article and Find Full Text PDFThe aim of this study is twofold: (i) characterization of the bottom ashes from the Incinerator plant of the city of Turin (northern Italy), in terms of their chemical/phase compositions and capacity to release heavy metals in leachates, as a function of particle size; (ii) investigation of thermal treatments' efficacy to promote inertization of the same bottom ashes, exploring time-temperature ranges with t ≤ 6 h and T ≤ 1000 °C. Special attention is paid to macro-sampling techniques in order to have samples that are representative of the average bottom ashes production. Micro-XRF, ICP-OES, SEM-EDS, Ion Chromatography and X-ray powder diffraction were used to investigate bottom ashes and leachates.
View Article and Find Full Text PDFThis work describes the design of a modified porphyrin that bears four furan rings linked by 1,2-bis-(2-aminoethoxy)ethane spacers. This unit is a well-suited scaffold for a Diels-Alder reaction with commercial reduced-graphene oxide, which is also described in this paper. A new hybrid material is obtained, thanks to efficient grafting under microwave irradiation, and fully characterized in terms of structure (UV, TGA, Raman) and morphology (HR-TEM and AFM).
View Article and Find Full Text PDFCyclodextrin-based nanosponges (NS) are solid nanoparticles, obtained from the cross-linking of cyclodextrins that have been proposed as delivery systems for many types of drugs. Various NS derivatives are currently under investigation in order that their properties might be tuned for different applications. In this work, new carboxylated cyclodextrin-based nanosponges (Carb-NS) carrying carboxylic groups within their structure were purposely designed as novel Acyclovir carriers.
View Article and Find Full Text PDFCamptothecin (CAM), a plant alkaloid and a potent antitumor agent, has a limited therapeutic utility because of its poor aqueous solubility, lactone ring instability and serious side effects. Cyclodextrin-based nanosponges (NS) are a novel class of cross-linked derivatives of cyclodextrins. They have been used to increase the solubility of poorly soluble actives, to protect the labile groups and control the release.
View Article and Find Full Text PDFAlkylcarbonates of gamma-cyclodextrins were produced and their inclusion complexes with four poorly water-soluble drugs of different structures and solubilities were prepared. The alkylcarbonates and the alkylcarbonate drug complexes were characterized by DSC and XRPD; the physical mixtures were used as control. Solubility capacities were evaluated by phase solubility studies.
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