79 results match your criteria: "Institute of Mineralogy and Crystallography[Affiliation]"
Biomed Mater Eng
August 2019
Department of Operative Dentistry and Endodontics, Medical University - Plovdiv, Plovdiv, Bulgaria.
Background: Human dentin is a highly calcified tissue of mesenchymal origin with a heterogeneous structure. Its morphology is constantly remodelled throughout the life span of the tooth, as well as under the influence of external stimuli.
Objective: The aim of the present study was to obtain information about the thermal changes in the crown and root dentin specimens of vital and devitalized teeth.
Dalton Trans
October 2018
Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Estrada Nacional 10, 2695-066 Bobadela LRS, Portugal.
Investigation of the system Th-Ni-B prompted a novel ternary compound ThNiB. X-ray structure analysis of single crystals obtained by the mechanical fragmentation of an as-cast sample revealed a fully ordered CeNiB-type structure (space group Cmc2, no. 36; a = 0.
View Article and Find Full Text PDFActa Crystallogr C Struct Chem
July 2018
Department of Inorganic Chemistry - Functional Materials, University of Vienna, Faculty of Chemistry, Althanstrasse 14, Vienna 1090, Austria.
A study of the ternary Rh-Mn-Bi phase diagram revealed the existence of two new ternary bismuthides, viz. hexarhodium pentamanganese octadecabismuthide (RhMnBi) and rhodium manganese tribismuthide (RhMnBi). Their crystal structures represent new structure types.
View Article and Find Full Text PDFInt J Nanomedicine
January 2018
Department of Pharmaceutical Sciences, Faculty of Pharmacy, Medical University-Plovdiv.
The purpose of the study was to investigate the stability and biopharmaceutical characteristics of ketoprofen, loaded in polymeric carriers, which were included into a bigel in a semisolid dosage form. The polymer carriers with in situ-included ketoprofen were obtained by emulsifier-free emulsion polymerization of the monomers in aqueous medium or a solution of the polymers used. The morphological characteristics of the carriers, the in vitro release and the photochemical stability of ketoprofen were evaluated.
View Article and Find Full Text PDFActa Crystallogr F Struct Biol Commun
September 2017
Institute of Mineralogy and Crystallography (IMC), Bulgarian Academy of Sciences, Acad. Georgi Bonchev Str., Bl. 107, 1113 Sofia, Bulgaria.
The structure of 4',6-diamidine-2-phenylindole (DAPI) bound to the synthetic B-DNA oligonucleotide d(CGTGAATTCACG) has been solved in space group P222 by single-crystal X-ray diffraction at a resolution of 2.2 Å. The structure is nearly isomorphous to that of the previously reported crystal structure of the oligonucleotide d(CGTGAATTCACG) alone.
View Article and Find Full Text PDFBioorg Med Chem Lett
October 2017
Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, bl. 26, Acad. G. Bonchev str., Sofia 1113, Bulgaria. Electronic address:
A series of twelve novel compounds, analogues of antiviral agent MDL-860 were synthesized and their antiviral activity was evaluated in vitro against enteroviruses poliovirus 1 (PV1), Coxsackieviruses B1 (CVB1) and Coxsackieviruses B3 (CVB3). Compounds 14, 24 and 25 manifested strong antiviral effects against CVB1 and PV1 (SI values of 405 and 118 for CVB1 and PV1 respectively). In contrast to the wide anti-enteroviral activity of MDL-860, these three compounds were inactive against CVB3.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2017
Leibniz Universität Hannover, Institute of Radioecology and Radiation Protection, Herrenhäuser Strasse 2, 30419, Hannover, Germany.
The crystallization of terbium 5,5'-azobis[1H-tetrazol-1-ide] (ZT) in the presence of trace amounts (ca. 50 Bq, ca. 1.
View Article and Find Full Text PDFBioorg Med Chem Lett
July 2017
Institute of Mineralogy and Crystallography, Bulgarian Academy of Sciences, 107 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria.
A new convenient method for preparation of 2-aroyl-[1]benzopyrano[4,3-c]pyrazol-4(1H)-one derivatives 5b-g and coumarin containing hydrazide-hydrazone analogues 4a-e was presented. The antimycobacterial activity against reference strain Mycobacterium tuberculosis H37Rv and cytotoxicity against the human embryonic kidney cell line HEK-293 were tested in vitro. All compounds demonstrated significant minimum inhibitory concentrations (MIC) ranging 0.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
April 2017
Institute of Organic Chemistry with Centre of Phytochemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria. Electronic address:
Mesoporous silica material type SBA-15 was modified with different amounts of Zn (2 and 4wt.%) by incipient wetness impregnation method in ethanol. The parent, Zn-modified and quercetin loaded samples, were characterized by XRD, N physisorption, TEM, thermal gravimetric analysis, UV-vis and FT-IR spectroscopies and in vitro release of quercetin at pH5.
View Article and Find Full Text PDFBioorg Med Chem Lett
January 2017
Bulgarian Academy of Sciences, Institute of Mineralogy and Crystallography, 107, Acad. G. Bonchev St., 1113 Sofia, Bulgaria.
This study reports the synthesis of new 2H-chromene or coumarin based acylhydrazones, which were evaluated for their in vitro antimycobacterial activity against reference strain Mycobacterium tuberculosis H37Rv and compared to the first-line antituberculosis drugs, isoniazid (INH) and ethambutol (EMB). The most active compounds 7m (MIC 0.13μM), 7o (MIC 0.
View Article and Find Full Text PDFColloids Surf B Biointerfaces
January 2017
Sofia University "St. Kliment Ohridski", Department of Biochemistry, Faculty of Biology, 8 Dragan Tzankov str., 1164 Sofia, Bulgaria. Electronic address:
Human bestrophin-1 (hBest1) is a transmembrane calcium-activated chloride channel protein - member of the bestrophin family of anion channels, predominantly expressed in the membrane of retinal pigment epithelium (RPE) cells. Mutations in the protein cause ocular diseases, named Bestrophinopathies. Here, we present the first Fourier transform infrared (FTIR) study of the secondary structure elements of hBest1, π/A isotherms and hysteresis, Brewster angle microscopy (BAM) and atomic force microscopy (AFM) visualization of the aggregation state of protein molecules dispersed as Langmuir and Langmuir-Blodgett films.
View Article and Find Full Text PDFPhys Chem Chem Phys
August 2016
Institute of Materials Chemistry and Research, University of Vienna, Währingerstraße 42, A-1090 Vienna, Austria. and Christian Doppler Laboratory for Thermoelectricity, Vienna, Austria.
As the Ti-Mn phase diagram is part of numerous ternary and higher order systems of technological importance, the present paper defines phase relations which have been experimentally established throughout this work from 800 °C to the melting range based on Differential Thermal Analyses (DTA), X-ray powder diffraction, metallography and Electron Probe Micro Analysis (EPMA) techniques on ∼50 alloys, which were prepared by arc melting or high frequency melting under high purity argon starting from freshly cleaned metal ingots. Novel compounds were identified and reaction isotherms were redefined accordingly. In the Ti-rich region a novel compound TiMn was detected, sandwiched between the known phases: TiMn1-x (∼45 at% Mn) and TiMn1+x (∼55 at% Mn).
View Article and Find Full Text PDFInorg Chem
August 2016
Institute of Materials Chemistry and Research, University of Vienna, Währingerstraße 42, A-1090 Wien, Austria.
Atom order in the crystal structures of Yb2Cu2-xMg (x = 0.17; Mo2FeB2-type; P4/mbm; a = 0.75592(2) nm; c = 0.
View Article and Find Full Text PDFDalton Trans
July 2016
Institute of Materials Chemistry & Research, University of Vienna, Währinger Straße 42, A-1090 Vienna, Austria. and Christian Doppler Laboratory for Thermoelectricity, Vienna, Austria.
Novel filled skutterudites BayNi4Sb12-xSnx (ymax = 0.93) have been prepared by arc melting followed by annealing at 250, 350 and 450 °C up to 30 days in vacuum-sealed quartz vials. Extension of the homogeneity region, solidus temperatures and structural investigations were performed for the skutterudite phase in the ternary Ni-Sn-Sb and in the quaternary Ba-Ni-Sb-Sn systems.
View Article and Find Full Text PDFEur J Med Chem
September 2016
University of Sofia "St. Kliment Ohridski", Faculty of Chemistry and Pharmacy, Department of Pharmaceutical and Applied Organic Chemistry, 1 James Bourchier Blvd, 1164 Sofia, Bulgaria.
In order to design and synthesize a new class of heterocyclic analogues of natural combretastatin A-4 and its synthetic derivative AVE8062, the benzoxazolone ring was selected as a scaffold for a bioisosteric replacement of the ring B of both molecules. A library of 28 cis- and trans-styrylbenzoxazolones was obtained by a modified Wittig reaction under Boden's conditions. Structures of the newly synthesized compounds bearing the 3,4,5-trimethoxy-, 3,4-dimethoxy-, 3,5-dimethoxy-, and 4-methoxystyryl fragment at position 4, 5, 6 or 7 of benzoxazolone core were determined on the basis of spectral and X ray data.
View Article and Find Full Text PDFDalton Trans
March 2016
Institute of Materials Chemistry and Research, University of Vienna, Währingerstraße 42, A-1090 Vienna, Austria. and Christian Doppler Laboratory for Thermoelectricity, Vienna, Austria.
Phase relations and crystal structures have been evaluated within the sections LaNi2Si2-LaZn2Si2 and CeNi2Si2-CeZn2Si2 at 800 °C using electron microprobe analysis and X-ray powder and single crystal structure analyses. Although the systems La-Zn-Si and Ce-Zn-Si at 800 °C do not reveal compounds such as "LaZn2Si2" or "CeZn2Si2", solid solutions {La,Ce}(Ni1-xZnx)2Si2 exist with the Ni/Zn substitution starting from {La,Ce}Ni2Si2 (ThCr2Si2-type; I4/mmm) up to x = 0.18 for Ce(Ni1-xZnx)2Si2 and x = 0.
View Article and Find Full Text PDFInorg Chem
November 2015
Institute of Solid State Physics, TU Wien , A-1040 Vienna, Austria.
On the basis of a detailed study applying X-ray single-crystal and powder diffraction, differential scanning calorimetry, and scanning electron microscopy analysis, it was possible to resolve existing uncertainties in the Pt-rich section (≥65 atom % Pt) of the binary Pt-B phase diagram above 600 °C. The formation of a unique structure has been observed for Pt2B [X-ray single-crystal data: space group C2/m, a = 1.62717(11) nm, b = 0.
View Article and Find Full Text PDFChempluschem
November 2015
Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria.
Sodium-deficient nickel-manganese oxides exhibit a layered structure, which is flexible enough to acquire different layer stacking. The effect of layer stacking on the intercalation properties of P3-Na Ni Mn O (x=0.50, 0.
View Article and Find Full Text PDFActa Crystallogr E Crystallogr Commun
June 2015
Centre of Advanced Studies in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025, India.
The complete mol-ecule of the title compound, C22H16N2O2, is generated by a crystallographic inversion centre at the mid-point of the central N-N bond. Two intra-molecular O-H⋯N hydrogen bonds occur.
View Article and Find Full Text PDFActa Crystallogr B Struct Sci Cryst Eng Mater
June 2015
Institute of Physical Chemistry, Johannes Gutenberg University, Jacob Welderweg 11, 55128 Mainz, Germany.
The M2O-Al2O3-WO3 (M = alkaline metals) system has attracted the attention of the scientific community because some of its members showed potential applications as single crystalline media for tunable solid-state lasers. These materials behave as promising laser host materials due to their high and continuous transparency in the wide range of the near-IR region. A systematic investigation of these phases is nonetheless hampered because it is impossible to produce large crystals and only in a few cases a pure synthetic product can be achieved.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
July 2015
Institute of Applied Problems of Physics, NAS of Armenia, 25 Nersessyan Str., 0014 Yerevan, Armenia. Electronic address:
β-Alaninium tetrafluoroborate crystallizes in the monoclinic system (space group P21/n, Z=4). The asymmetric unit contains one β-alaninium cation and one tetrafluoroborate anion, in which the fluorine atoms are disordered. All β-alaninium cations are connected with the symmetry related cations via an inversion center, thus forming dimeric centrosymmetric β-Ala(+)···β-Ala(+) cations.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2016
National Academy of Art, Faculty of Applied Arts, Sofia, Bulgaria.
A profound study of samples obtained from Thracian tomb wall paintings at Alexandrovo, Bulgaria (dating back to the fourth century BC) were carried out by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and Attenuated Total Reflectance Fourier transform infrared spectroscopy (ATR FTIR), high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDS). The current work provides a glimpse of the ingenious construction and painting techniques used in Thracian tomb at Alexandrovo. The results suggest that beeswax was used as a paint binder and also revealed presence of various nano-materials.
View Article and Find Full Text PDFJ Solid State Chem
December 2014
Institute of Inorganic Chemistry (Materials Chemistry), University of Vienna, Währingerstraße 42, A-1090 Wien, Vienna.
The stannides CuLiSn (CSD-427095) and CuLiSn (CSD-427096) were synthesized by induction melting of the pure elements and annealing at 400 °C. The phases were reinvestigated by X-ray powder and single-crystal X-ray diffractometry. Within both crystal structures the ordered CuSn and CuSn lattices form channels which host Cu and Li atoms at partly mixed occupied positions exhibiting extensive vacancies.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
February 2015
Institute of Applied Problems of Physics, NAS of Armenia, 25 Nersessyan Str., 0014 Yerevan, Armenia. Electronic address:
L-tryptophan L-tryptophanium chloride is a new salt with (A⋯A(+)) type dimeric cation. It crystallizes in the monoclinic system (space group P2(1), Z=2). The asymmetric unit contains one zwitterionic L-tryptophan molecule, one L-tryptophanium cation and one chloride anion.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2014
Departments of Human Evolution and.
The first settlement of Europe by modern humans is thought to have occurred between 50,000 and 40,000 calendar years ago (cal B.P.).
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