Orthorhombic Polymorph of ErP5O14, Crystal Structure and Characterization

Erbium pentaphosphate crystals have been characterized and the structure of the orthorhombic polymorph (type III) determined by X-rays. It has been found that the orthorhombic samples of ErP₅O₁₄, space group Pnma, crystallize mainly at higher temperatures and usually are much larger than monoclinic crystals, space group C2/c, obtained from lower-temperature crystallizations. Differences in fluorescence and upconversion properties between orthorhombic and monoclinic polymorphs have been detected.     

Biocompatibility of monoelementary carbon polymer prepared for the soft and hard tissue implantation

Abstract

Glassy-like carbon to be applicable in two amas of advanced technology:

1—as Source of sp³ organizad carbon orbitals in HP/HT diamond synthesis [1].

2—as chamically inert parts for implantation in surgery [2].

For first application the temporatwe of carbonization proam should be lower thau 1300 K, for the second one higher than 1300 K (the best ?1473 K). Usefafnercr of dense body for surgery prepared by us was analysed on: as heart valves and as parts for face-skull restoration. Biocompatibility was tested in soft tisrue of ratrr, pig8 and dogs. Positive results have shown that such a body may be applicable as biomaterial.     

Synthesis and structure of novel 4-arylhexahydro-1H,3H-pyrido[1,2-c]pyrimidine derivatives

A series of new 4-aryl-hexahydro-1H,3H-pyrido[1,2-c]pyrirnidine-1,3-dione derivatives 4a-k were prepared by catalytic hydrogenation of 4-aryl-1H,2H-pyrido[1,2-c]pyrirnidine-1,3-diones 3a-k. The structures of compounds were determined by ¹H and ¹³C nmr spectroscopy in solution. Steric hindrance caused twisting of the phenyl ring with respect to the pyridopyrimidine system, the effect was confirmed by X-ray diffraction.     

The Storage and Handling of Polymer Latices Used as Particle Standards

Latices of 2, 4 and 9 μm diameter intended for use a particle standard have been examined under a variety of storage and handling conditions. The effects of light exposure, temperature variation and storage in isotonic saline were studied as well as the handling conditions, such as multiple sampling, dispersion technique and effects of foaming. Particle sizes and particle number densities were remarkably constant, even under the most extreme conditions investigated.     

Cinnamates. III. The light sensitive polymers: Cinnamates with internal charge-transfer spectroscopic properties

In this paper, we outline the photochemical and spectroscopic properties of a new light-sensitive polymer obtained as a result of polystyrene modification by attachment of a pendant 4-dimethylamino-cinnamate ester group. This specific cinnamate displays typical charge-transfer character in the absorption and emission spectra. The photochemical and photophysical properties of photopolymer are compared with the monomeric model photochemistry and photophysics.     

Redoxindicatoren in der indirekten volumetrischen Anionenbestimmung

Zusammenfassung Es wurde eine indirekte volumetrische Methode zur Bestimmung der Sulfationen (2–100 mg) durch Fällung mit einer Bleinitratlösung und Abtitrieren der überschüssigen Bleiionen mit Kaliumhexacyanoferrat(II)-lösung in 75% igen Methanollösungen gegen den Redoxindicator Variaminblau ausgearbeitet.Natrium-, Kalium- und Ammoniumionen können ohne zu stören in bis zu 5fachem Überschuß im Verhältnis zu den abtitrierten Bleiionen zugegen sein. Die Ionen der 2- und 3 wertigen Metalle werden durch Fällung mit Kaliumcarbonatlösung entfernt. Das Verfahren wurde mit Erfolg zur Sulfatbestimmung in Wässern und Metallsulfaten angewandt.Gewidmet Herrn Prof. Dr. W.Jakób aus der Jagiellonischen Universität in Kraków.     

The photolysis of 1-(4,5-dihydro-1H-imidazol-2-yl)benzotriazole

1-(4,5-Dihydro-1H-imidazolo-2-yl)benzotriazole was photolyzed at 254 nm yielding 1,2-dihydro-4H-imidazo-[1,2-a]benzimidazole.     

High performance capillary electrophoresis method for determination of ibuprofen enantiomers in human serum and urine

A direct and stereospecific capillary zone electrophoresis (CZE) method for quantification ibuprofen enantiomers in biological matrices: human serum and urine, has been developed. Chiral separation of the enantiomers of ibuprofen and (+)-S-indobufen [(+)-S-INDB, internal standard, IS] was obtained in an uncoated silica capillary filled with a background electrolyte (BGE), consisted of heptakis 2,3,6-tri-O-methyl-β-cyclodextrin (TM-β-CD) in buffer of pH 5.0. The complete enantioselective analysis of ibuprofen and its 1-hydroxy metabolite confirmed appropriate specificity of the method. The electrophoretic parameters: electroosmotic (μ_EOF) and electrophoretic (μ_ep) mobility and resolution factor (R_s) were determined. Extraction procedures with organic solvent and solid phase extraction (SPE) with C₁₈ stationary phase for isolation of enantiomers from biological fluids were compared. SPE method for further studies was chosen. Stereoselective extraction of IBP enantiomers from serum at basic pH has been discovered. Validation of the method was carried out. Calibration curves of ibuprofen enantiomers were linear in the range of 0.1-25.0 μg/ml in serum and of 0.5-250.0 μg/ml in urine. Recovery of both enantiomers from serum and urine amounted 74-86 and 90-98%, respectively. Intra- and inter-day measurement precision and accuracy were below 15%. Limits of detection for IBP enantiomers amounted 0.05 and 0.25 μg/ml in samples of serum and urine, respectively. Limit of quantitation was also estimated. IBP enantiomers proved to be stable following three freeze and thaw cycles and during storage in autosampler at ambient temperature. The validated methods enable pharmacokinetic studies of enantiomers in both media. The elaborated HPCE method can be alternative to HPLC.