316 research outputs found

    Reactions of p-Nitrophenyloxirane with Amines Containing Fragments with Bicyclic Skeleton

    Get PDF
    Reactions of p-nitrophenyloxirane with amines containing fragments with bicyclic skeleton of norbornene, norbornane, epoxynorbornane (stereoisomeric exo- and endo-5-aminomethylbicyclo[2.2.1]hept-2-enes, N-benzyl-endo-5-aminomethylbicyclo[2.2.1]hept-2-ene, endo-5-(2-aminoethyl)bicyclo[2.2.1]hept-2-ene, stereoisomeric exo- and endo-2-aminomethylbicyclo[2.2.1]heptanes, 2-(1-aminoethyl)bicyclo[2.2.1]-heptane, exo-5-aminomethyl-exo-2,3-epoxybicyclo[2.2.1]heptane) were investigated. The aminolysis of pnitrophenyloxirane occurred regioselectively according to Krasusky rule as was proved by 1H and 13C NMR data. As shown by 1H and 13C NMR spectroscopy the oxyalkylation product obtained from N-benzyl-endo-5-aminomethylbicyclo[2.2.1]hept-2-ene was composed of two diastereomers originating from the presence of a chiral nitrogen atom in the rear part of the rigid bicyclic skeleton. New products of amino groups transformation in the molecules of hydroxyamines were obtained by reaction with p-methylbenzoyl chloride and p-nitrophenylsulfonyl chloride. Regioselectivity of the attack of electrophilic reagents on the nitrogen in the hydroxyamines was confirmed by IR and 1H NMR spectra of the products. The data on pharmacological activity tests of N-2-hydroxyethyl(p-nitrophenyl)-5-aminomethylbicyclo[2.2.1]hept-2-ene are reported

    Determination Methods of Food Fibers Characteristics in Milk Mixtures with the Modified Fat Composition

    Full text link
    The article presents main determination methods of technological parameters of food fibers in milk mixtures of the modified fat composition.The methods of studying the ability of food fibers to water and fat-absorption are offered. The values that characterize swelling parameters of vegetable ingredients in experimental mixtures are obtained.The effectiveness of the method of IR-spectroscopy for indentifying and comparing water-binding forms in mixtures of food fibers with water and butterdish is proved.The indices of thermal stability and degree of liquid fat outflow for mixtures with the modified fat composition with the maximal replacement of cream butter by 25 % of oil are obtained. The research results indicate objective possibilities for the effective use of food fibers Vicetal for stabilizing the structure and preventing consistence defects of products with the modified fat composition

    A study of cell membranes in nasal epithelial cells from patients with chronic rhinosinusitis with nasal polyps by means of a fluorescent probe

    Get PDF
    Aim. To assess the state of membranes in nasal epithelial cells obtained from the patients with chronic rhinosinusitis with nasal polyps (CRSwNP) with the help of the fluorescent probe 2-(2ʹ-ОН-phenyl)-5-phenyl-1,3-oxazole. Methods. The state of membrane phospholipid bilayer in suspensions of nasal epithelial cells isolated from ten patients with CRSwNP was evaluated using the fluorescent probe 2-(2ʹ-ОН-phenyl)-5-phenyl-1,3-oxazole that reacts on the physico-chemical properties of its microenvironment. Changes in fluorescence spectra were determined using a Thermo Scientific Lumina fluorescence spectrometer (Thermo Fisher Scientific) 1 hour after the addition of the probe to nasal epithelial cell suspensions. Results. CRSwNP was found to be associated with a higher rate of nasal epithelial cell membrane hydration in the region of phospholipid glycerol moiety, carbonyl groups and aliphatic chains of fatty acids attached to the carbonyl groups. Conclusion. Our findings suggest that CRSwNP is accompanied by the elevated hydration rate of the most polar region, namely polar heads of phospholipids of nasal epithelial cell membranes

    A study of cell membranes in nasal epithelial cells from patients with chronic rhinosinusitis with nasal polyps by means of a fluorescent probe

    Get PDF
    Aim. To assess the state of membranes in nasal epithelial cells obtained from the patients with chronic rhinosinusitis with nasal polyps (CRSwNP) with the help of the fluorescent probe 2-(2ʹ-ОН-phenyl)-5-phenyl-1,3-oxazole. Methods. The state of membrane phospholipid bilayer in suspensions of nasal epithelial cells isolated from ten patients with CRSwNP was evaluated using the fluorescent probe 2-(2ʹ-ОН-phenyl)-5-phenyl-1,3-oxazole that reacts on the physico-chemical properties of its microenvironment. Changes in fluorescence spectra were determined using a Thermo Scientific Lumina fluorescence spectrometer (Thermo Fisher Scientific) 1 hour after the addition of the probe to nasal epithelial cell suspensions. Results. CRSwNP was found to be associated with a higher rate of nasal epithelial cell membrane hydration in the region of phospholipid glycerol moiety, carbonyl groups and aliphatic chains of fatty acids attached to the carbonyl groups. Conclusion. Our findings suggest that CRSwNP is accompanied by the elevated hydration rate of the most polar region, namely polar heads of phospholipids of nasal epithelial cell membranes

    Determination Methods Of Defrosted Protein-vegetable Mixtures Parameters Development

    Get PDF
    The aim of the work is to develop methods of investigating the influence of semolina and extruded semolina on quality and quantity parameters of mixtures with milk-protein concentrates in a cycle of freezing-defrost that allows to substantiate resource-saving in semi-products manufacturing.Obtained results of changes of the quality of protein-vegetable mixtures after the effect of negative temperatures confirm cryo-protective properties of carbohydrates of products of wheat processing.There were studied methods of extracting proteins of whey for getting albumin mass and using in the composition of milk-protein concentrates. It was established, that adding collagen-containing ingredients in amount 0,4 % for intensifying thermal coagulation of whey proteins decreases the duration of precipitation to (55±2) and (40±2) min respectively depending on a type of raw material processing. There were studied both native whey and protein concentrate, obtained by the method of ultra-filtration with mass share of dry substances (16±2) %.The method of thermal analysis determined a cryoscopic temperature of sour-milk fatless cheese and also albumin mass, obtained using «Collagen pro 4402». The calculation method, based on cryoscopic temperature indices determined an amount of moisture, frozen out in milk-whey mixtures with wheat processing products. The presented information is enough for estimating traditional modes of freezing milk-protein concentrates objectively.The obtained results of the studies indicate the effectiveness of the offered methods for determining parameters of protein-vegetable mixtures after defrosting. Measurements of quality parameters may be used for correcting mass losses of concentrates effectively

    Spectral Formation in Accreting X-Ray Pulsars: Bimodal Variation of the Cyclotron Energy with Luminosity

    Full text link
    Accretion-powered X-ray pulsars exhibit significant variability of the Cyclotron Resonance Scattering Feature (CRSF) centroid energy on pulse-to-pulse timescales, and also on much longer timescales. Two types of spectral variability are observed. For sources in group 1, the CRSF energy is negatively correlated with the variable source luminosity, and for sources in group 2, the opposite behavior is observed. The physical basis for this bimodal behavior is currently not understood. We explore the hypothesis that the accretion dynamics in the group 1 sources is dominated by radiation pressure near the stellar surface, and that Coulomb interactions decelerate the gas to rest in the group 2 sources. We derive a new expression for the critical luminosity such that radiation pressure decelerates the matter to rest in the supercritical sources. The formula for the critical luminosity is evaluated for 5 sources, using the maximum value of the CRSF centroid energy to estimate the surface magnetic field strength. The results confirm that the group 1 sources are supercritical and the group 2 sources are subcritical, although the situation is less clear for those highly variable sources that cross over the critical line. We also explain the variation of the CRSF energy with luminosity as a consequence of the variation of the characteristic emission height. The sign of the height variation is opposite in the supercritical and subcritical cases, hence creating the observed bimodal behavior.Comment: Accepted for publication in Astronomy & Astrophysic

    Pyramidal amide nitrogen in N-acyloxy-N-alkoxyureas and N-acyloxy-N-alkoxycarbamates

    Get PDF
    The XRD studies of N-acyloxy-N-alkoxyamides 1, 2 have revealed a highly pyramidal configuration of amide nitrogen in the O–N–O group

    Synthesis, structure and properties of N-alkoxy-N-(1-pyridinium)urea salts, N-alkoxy-N-acyloxyureas and N,N-dialkoxyureas

    Get PDF
    N-Alkoxy-N-(1-pyridinium)urea salts 3, 4 have been prepared, the conversions of N-acetoxy-N-methoxyurea 7 into N,N-dimethoxyurea 8 and of N-n-propyloxy-N-(1-pyridinium)-N',N'-dimethylurea chloride 6 into N,N dimethoxy-N',N'-dimethylurea 11 were carried out. A high pyramidality of the amide nitrogen in O–N–X groups [X = N+C5H5, OMe, OC(O)C6H4Cl-p] has been revealed by XRD studies of ureas 3b, 8 and N-p chlorobenzoyloxy-N-n-butyloxyurea 9
    corecore