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Single phase β-NaY0.8-xGdxYb0.18Er0.02F4 nanoparticles with different concentrations of gadolinium ions were prepared via PVP-assisted solvothermal treating at 200°C (PVP- polyvinylpyrrolidone). With the increase in Gd3+ concentration, size of the nanoparticles decreased. The up-converting spectra recorded upon 980 nm irradiation showed the green (510-560 nm) and red (640-690 nm) emissions, due to 2H11/2, 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions, respectively. The strongest up-conversion luminescence was detected in 15 mol% Gd3+-doped nanoparticles obtained after 20 hours of solvothermal treating. With the rise of Gd3+ content up-conversion emission decreased due to increased defect concentration in the NaYF4 matrix. Fourier transform infrared spectroscopy proved in situ generation of hydrophilic nanoparticles as a result of PVP ligands retention at the particle surface.

DK-I-56–1 (7‑methoxy‑2-(4‑methoxy‑d3-phenyl)-2,5-dihydro-3H-pyrazolo[4,3-c]quinolin-3-one), a recently developed deuterated pyrazoloquinolinone, has been recognized as a lead candidate for treatment of various neuropsychiatric disorders. During preclinical investigation of poorly water-soluble compounds such as DK-I-56–1, the application of nanotechnology could be advantageous due to improved safety and possibly increased bioavailability of nanosized formulation. DK-I-56–1 nanosuspensions stabilized by polysorbate 80, alone or in combination with poloxamers 188 i.e. 407 or D-α-tocopheryl polyethylene glycol 1000 succinate, were prepared using a small-scale media milling device. With particle size 208.7–250.6 nm and polydispersity index <0.250, selected nanodiseprsions were stable for three weeks. Pharmacokinetic and biodistribution studies following intraperitoneal administration of three types of formulation in mice indicated high plasma DK-I-56–1 levels after solution (10,228.6 ± 1037.2 ngh/ml) and nanosuspension (6770.4 ± 770.7 ngh/ml) but not suspension administration (966.0 ± 58.1 ngh/ml). However, distribution of DK-I-56–1 after solution was heavily influenced by its composition, and brain availability of nanosuspension was superior to that of solution formulation. In spontaneous locomotor activity test, the expected hyperlocomotor effect was observed after nanosuspension administration, without compromising impact of the vehicle/excipients used. Therefore, nanonization of drug compound assembled with proper selection of stabilizers may seemingly contribute further thorough testing of DK-I-56–1 preclinical efficacy.

Barium titanate (BaTiO3) attracts high scientific and technological attention due to good dielectric and electromechanical properties. Although BaTiO3 is one of the most frequently investigated ferroelectric materials, the need for finding new and/or improved synthesis methods of this material still exists. In this paper, a novel, mild synthesis route for producing tetragonal BaTiO3 from barium nitrate and Ti-oxalate precursor is presented. Morphology of the prepared and subsequently sintered BaTiO3 was determined by SEM. Particle size distribution of the as prepared powder was monitored by the laser diffraction. The phase composition, structure and lattice dynamics were investigated by XRD and Raman spectroscopy. Finally, dielectric parameters were determined in the temperature range from 30 to 180 degrees C, and within a variety of frequencies. Curie temperature was detected at 130 degrees C.

Pt(II) and Pd(II) complexes (1 and 2, respectively) with thiomorpholine-4-carbonitrile (TM-CN), an N-substituted thiomorpholine derivative, were synthesized from tetrachlorido precursors in water. Structural analysis has shown that 1 represents the first monomeric metal complex with this ligand type with an axial M-S bond with respect to the TM-CN ring chair conformation, while in 2 a typical equatorial M-S bond position with respect to the ring chair conformation was observed. A detailed DFT investigation revealed that axial conformers are more stable for molecular forms of both metals, while intermolecular interactions in the crystals stabilize the axial conformer for Pt(II) and the equatorial conformer for Pd(II). The magnitude of this stabilization in the case of 2 is large enough to change the most stable axial conformer in the molecular form to the equatorial conformer in the crystal. Further investigation of the strength of individual intermolecular interactions revealed significant differences of some interactions between the two structures. The likely cause of the difference in the crystal structures of experimentally obtained complexes is the fact that 1 and 2 exhibit different dominant interactions: C-H/M and C-H/S are more dominant in 1 and C-H/Cl interactions are more dominant in 2. In addition, DFT calculations have shown that while the axial position of the Pt-S bond with respect to the ring chair conformation results in a significantly shorter C-H/Pt interaction distance than that in the hypothetical equatorial conformer, there is very little difference in C-H/Pd interaction distances in conformers with axial and equatorial positions of Pd-S bond with respect to the ring chair conformation.

Four silver-based coordination polymers, {[Ag(L)(2)](BF4)}(infinity) (1), {[Ag(H2BTC)(L)]center dot(H3BTC)}(infinity) (2), {[Ag-2(H2BTEC)(L)(2)]..3.33H(2)O}(infinity) (3), and [Ag(H(25)SSA)(L)](infinity) (4), were synthesized using thiomorpholine-4-carbonitrile (L) as the primary ligand and three aromatic polyoxoacids as coligands: trimesic (H3BTC), pyromellitic (H4BTEC), and 5-sulfosalicylic acid (H(35)SSA). Compounds 1 and 3 are two-dimensional, while 2 and 4 are one-dimensional. L acts as a bis-monodentate ligand, while the Ag(I) ion is three-coordinated in 2 and four-coordinated in all of the other compounds. The tetrahedral coordination of Ag(I) in 3 leads to an almost complete absence of intermolecular interactions with the metal center. All compounds show reasonable photocatalytic activity for photocatalytic degradation of mordant blue 9 dye, with reaction rates in the 0.036-0.056 min(-1) range. Changes in the reaction rates can be correlated with the type and coordination of the coligand. Complex 3 exhibits photoluminescence at 77 K, while 4 exhibits photoluminescence at both room temperature and 77 K. Luminescence lifetimes indicate electronic transitions of singlet parentage, where transitions are allowed. A TD-DFT study determined the contributions of individual singlet-singlet electronic excitations to the fluorescence, indicating that metal- intraligand transitions are responsible for luminescence in both complexes.

This work is the first report of a very simple and fast one-pot synthesis of nickel oxide (NiO) and hematite (α-Fe2O3) nanoparticles by thermal decomposition of transition metal aqua complexes with camphor sulfonate anions. Obtained nanopowders were characterized by X-ray powder diffraction, Fourier transform IR analysis, scanning electron microscopy, and Energy-dispersive X-ray spectroscopy. X-ray powder diffraction confirmed the formation of high purity NiO and α-Fe2O3 crystal phases. In the case of α-Fe2O3, about five times larger average crystallite size was obtained. Fourier transform IR spectra of synthesized materials showed characteristic peaks for NiO and α-Fe2O3 nanostructures. To visualize the morphology and the chemical composition of the final products Scanning electron microscopy and Energy-dispersive X-ray spectroscopy were performed. The thermogravimetric analysis was done for a better understanding of the general thermal behavior of precursor compounds. This easy-to-perform and fast preparation method opens a broad range of obtained materials’ usage, particularly due to its economic viability

The goal of this work was the synthesis of a montmorillonite based catalyst for advanced oxidative degradation of organic water pollutants. Montmorillonite (Mt) –rich bentonite was acid-activated (MtA), and impregnated with cobalt (II) solution using the incipient wetness impregnation method. The impregnation was followed by heat treatment. Cobalt(II) ions were added in the quantities corresponding to 0.5 and 1.0 of the cation exchange capacity value. All samples were characterized by using chemical analysis, X-ray powder diffraction (XRPD), Electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) coupled with Energy-dispersive X-ray spectroscopy (EDS), Transmission electron microscopy (TEM) and low temperature N2 physisorption. The incorporation of the cobalt in the impregnated samples and the development of porous structure in the acid-activated ones were confirmed. The montmorillonite (Mt) was used as a catalyst support, while the cobalt in its oxide form was responsible for the generation of sulfo-radicals from Oxone®. Two aromatic N-compounds were tested as model pollutants: diazo dye - Acid Orange 10 (AO10) and nicotine. It was found that the synthesized catalysts could be used for the degradation of both pollutants, although more efficiently in AO10 degradation. The acid activation, higher cobalt loading, and temperature were found to be beneficial for the degradation of AO10.

The goal of this work was the synthesis of a montmorillonite based catalyst for advanced oxidative degradation of organic water pollutants. Montmorillonite (Mt) –rich bentonite was acid-activated (MtA), and impregnated with cobalt (II) solution using the incipient wetness impregnation method. The impregnation was followed by heat treatment. Cobalt(II) ions were added in the quantities corresponding to 0.5 and 1.0 of the cation exchange capacity value. All samples were characterized by using chemical analysis, X-ray powder diffraction (XRPD), Electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) coupled with Energy-dispersive X-ray spectroscopy (EDS), Transmission electron microscopy (TEM) and low temperature N2 physisorption. The incorporation of the cobalt in the impregnated samples and the development of porous structure in the acid-activated ones were confirmed. The montmorillonite (Mt) was used as a catalyst support, while the cobalt in its oxide form was responsible for the generation of sulfo-radicals from Oxone®. Two aromatic N-compounds were tested as model pollutants: diazo dye - Acid Orange 10 (AO10) and nicotine. It was found that the synthesized catalysts could be used for the degradation of both pollutants, although more efficiently in AO10 degradation. The acid activation, higher cobalt loading, and temperature were found to be beneficial for the degradation of AO10.

In this paper we present the phase and morphological characteristics of urinary stones from Serbian patients. The study included for the first time the determination of the phase composition and a statistical analysis of the presence of different types of urinary stones in both men and women in Serbia. The main goal of study was representation of collected data for the first time. For past three years, more than 600 samples were collected from Serbian patients. The phase composition of all samples of urinary stones was investigated using XRD analysis. Morphology and chemical composition of phases in some characteristic samples was determinate by the SEM-EDS analysis. Results indicate that there are several different types of urinary stones that vary in mineral composition, chemistry and morphology. It was found that 312 (52%) of the 600 stones were composed of calcium oxalate minerals (CaOx): 17.3% of which were pure calcium oxalate monohydrate COM, 4% were pure calcium oxalate dihydrate COD; 200 (33.3%) were a mixture of CaOx and Hydroxyapatite HA, 19 (3.1%) were uric acid (uricite) UA and uric acid dihydrate UAD, 17 (2.8%) were a combination of UA and CaOx minerals, 41 (6.8%) were combination of CaP minerals and CaOx, 11 (1.9%) were cystine (Cy) stones. The obtained data shows the diversity of types of urinary stones. Morphological, chemical and XRPD analysis give us statistical data which shows that the most common urinary stones from Serbian patients are from CaOx group and in most of cases are associated with CaP. © 2019 Elsevier B.V.

A simple organic-phase synthesis process was used to produce bare NiFe2O4 and ZnFe2O4 and core-shell ZnFe2O4@NiFe2O4 ferrite nanoparticles. X-ray powder diffractograms for all investigated powders show characteristic peaks of a spinel cubic structure without a secondary phase. Transmission electron microscopy (TEM) indicated the presence of nanoparticles that are smaller than 20 nm. The release of divalent ions (Ni2+ and Zn2+) from synthesized nanoparticles that were dispersed in saline solution, phosphate-buffered saline (PBS) and human serum, as determined by the inductively coupled plasma mass spectrometry (ICP-MS) method, was lower than 2 wt %. These results demonstrate the stability of the investigated nanoparticles in biologically relevant media and exclude the toxicity of Ni2+ and Zn2+ due to metal ion release, thereby opening a broad range of (bio)medical applications.

Izrada velike studije o opekarskoj proizvodnji VII Klaudijeve legije na teritoriji provincije Gornje Mezije započeta je pre desetak godina. Glavni logor legije i centar njene proizvodne delatnosti u periodu od kraja I do kraja IV veka nalazio se u Viminacijumu. Osim ostataka 16 peći za pečenje opeka, koji direktno svedoče o opekarskoj proizvodnji na prostoru Viminacijuma (Jevtović, Danković in press) (slika 1), do sada je prikupljena i kolekcija od oko 2000 opeka sa žigom VII Klaudijeve legije, različitih formata (imbrex, tegula, lydion, bessalis, pedalis, bipedalis)*, kao i ulomci opeka nedefinisane forme. Krajem 2019. godine započeta je i mineraloško-petrološka analiza opeka sa ciljem da se utvrde njihov sastav, karakteristike glinene paste, tehnologija proizvodnje, kao i poreklo sirovine. Prvobitna ispitivanja obuhvatila su uzorke pronađene tokom novih istraživanja legijskog utvrđenja koje se nalazi na lokalitetu Čair – Castrum**.

In this paper, grandite core with Grs64±1Adr36±1Sps2 composition was crystallographically studied. This core represents zone A of the macroscopically visible five A–E zones of the optically anisotropic Grs58–64Adr36–42Sps2 grandite. The applied procedure includes the detailed analysis of the powder diffraction patterns, and the Rietveld refinements of the crystal structures in a series of 18 space groups and two mixtures, which were followed by the comparative analysis of the R-values, site occupancy factors, and the bond lengths and angles. Synthesis of all of the presented results allows us to undoubtedly conclude that studied grandite is not cubic, neither as monophase nor as multiple phases in a mixture. Namely, it was established that structural dissymmetrization occurred and that it crystallized in the disordered rhombohedral R-3c or orthorhombic Fddd space groups, whereby the first one is more probable. Beside the established lower symmetry of the studied grandite, which could be treated as the primary cause, the residual strain is also not excluded as the second possible cause for its slight optical anisotropy.

Monosized up-converting nanoparticles (UCNPs) with a spherical shape and biocompatible surface have a wide application in biomedicine as new cell markers or light-triggered drug delivery agents. The synthesis of the hexagonal β-NaYF4:Yb/Er phase is of a great interest, because of its most efficient up-conversion luminescence. Beside it, synthesis of the UCNPs based on YF3:Yb/Er phase is also attractive due to its orthorhombic phase arrangement and fact that higher concentration of dopants could be introduced in such crystal lattice. In this work the synthesis of pure and Gd-doped YF3:Yb/Er phases were performed through hydro/solvo thermal method using a biocompatible chitosan as a surfactant. The XRD analysis showed that independently of the gadolinium content formation of the orthorhombic phase is achieved, but intensity of the green emission due to the (2H11/2, 4S3/2) → 4I15/2 electronic transitions was highest for un-doped YF3:Yb/Er sample.