bluuebunny/crossref_metadata_2025 huggingface dataset:
Reactions of arenecarbonyl isothiocyanates with hydrazine hydrate and arylhydrazines
Authors: Uher Michal , Bošanský Miloš , Kováč Štefan , Martvoň Augustin
Published: January 2014

This paper describes the preparation of 1,2,4-triazoline-5-thiones from arenecarbonyl isothiocyanates and hydrazine hydrate or arylhydrazines. The IR, UV and mass spectra are commented.
Affinity chromatography of guanyloribonuclease from streptomyces aureofaciens
Authors: Kois Pavol , Rosenberg Ivan , Holý Antonín
Published: January 2014

2',3'-O-2-Carboxyethylideneinosine 5'-phosphate (Ia), 5'-phosphorothioate (IIa), 5'-O-carboxymethylinosine 2'(3')-phosphate (IIIa) and 2'(3')-phosphorothioate (IVa) were bound to 6-aminohexyl-Sepharose 4B by the method of mixed anhydrides with ethyl chloroformate. 5'-O-(2-Aminoethylamidocarbonylmethyl)inosine 2'(3')-phosphorothioate (Va), O-(4-aminophenyl)inosine 5'-phosphorothioate (VIa) and O-(4-aminophenyl)-O-phenyl phosphorothioate (VIIa) were bound to Sepharose 4B activated with cyanogen bromide. The resulting modified supports IIa-VIb bind the ribonuclease of Streptomyces aureofaciens within the pH range 6.5-7.5. The specific affinity bond manifests itself in derivatives with ligands of type IVb and Vb, on which a 50-70fold purification degree can be achieved, with respect to the crude preparation.
Influence of medium on alkaline hydrolysis of succinic acid monomethyl and monopropyl esters
Authors: Holba Vladislav , Benko Ján
Published: January 2014

The kinetics of alkaline hydrolysis of succinic acid monomethyl and monopropyl esters were studied in mixed aqueous-nonaqueous media at various temperatures and ionic strengths. The results of measurements are discussed in terms of electrostatic and specific interactions between the reactants and other components of the reaction mixture. The kinetic parameters in the media under study are related to the influence of the cosolvent on the solvation sphere of the reactants.
Catalytic effect of cetyltrimethylammonium bromide on the radical destruction oxidation of pyrocatechol violet
Authors: Lasovský Jan , Březina František , Nekl Ladislav
Published: January 2014

The effect of cetyltrimethylammonium bromide (I) on the radical oxidation of pyrocatechol violet by hydrogen peroxide was studied in the presence of N,N'-ethylenediamine-bis(o-aminobenzaldimine)cobalt(II) bromide and cobalt dichloride. After a short, faster period the reaction obeys the 1st order formalism. In the presence of I the experimental rate constants are as much as 42 times higher than in "pure" solutions. In optimum conditions (dye concentration 1.75 . 10-4 mol l-1) the reaction can be described in terms of the usual formalism of micellar catalysis. In solutions containing I the effect of cobalt compounds can be traced down to cobalt concentration levels of 10-8 mol l-1. The dependences of the experimental rate constants on the concentrations of hydrogen peroxide and cobalt compounds and on the temperature and pH are discussed.
High-performance liquid chromatography of carba-analogues of oxytocin; a method for the determination of sulfides and sulfoxides in peptides
Authors: Lebl Michal
Published: January 2014

Chromatographic properties of peptides derived from deamino-oxytocin, differing in the structure of the disulfide bridge region, were studied on a column with reversed phase. On the basis of chromatographic data the non-equivalence of the sulfur atoms in deamino-oxytocin was discussed. The analogues derived by oxidation or substitution of amino acids in the position 2 or 4 were also submitted to investigation. Rapid and selective oxidation of sulfide with periodate to sulfoxide, or the reduction of the latter with hydrogen bromide and acetone, was made use of for the determination of sulfide and sulfoxide in peptide containing sulfur-containing amino acid. The method was checked with free and protected peptides.
Synthesis of bridgehead chloro-, bromo- and iodobicyclo[2.2.2]octanes
Authors: Kopecký Jan , Šmejkal Jaroslav
Published: January 2014

The paper describes transformations of hydroxy-, acetoxy- or methoxy-bridgehead bicyclo[2.2.2]octanes into bridgehead chloro, bromo or iodo derivatives by action of inorganic halides in the medium of orthophosphoric or polyphosphoric acids.
Splitting off of water from the molecular ions of steroidal cyclopropyl ketones
Authors: Kasal Alexander , Trka Antonín
Published: January 2014

Mass spectra of 14 steroids containing a cyclopropane ring in the vicinity of a keto group were measured and the signals of the ions [M-H2O]+, [M-CH3]+ and [M-CO]+ were sought. Using models labelled selectively with deuterium it was shown that the water molecule, split off from the molecular ion of 3α,5-cyclo-5α-cholestan-6-one (I) is formed from the hydrogen atoms located in the positions 2β and 9α.
Synthesis of 14-deoxy-14α-strophanthidin
Authors: Kočovský Pavel
Published: January 2014

A seventeen step synthesis of 3β,5-dihydroxy-19-oxo-5β,14α-card-20(22)-enolide (II, title compound) from 3β-benzoyloxy-5-pregnen-20-one (IV) is described. Characteristic features of this approach are the protection of the 19-hydroxy group as methyl ether, recovery of the hydroxyl and the introduction of 5β-hydroxyl on the basis of neighboring group participation. The 19-hydroxy group was regenerated in XIV by a two-step process: Addition of hypobromous acid to the 5,6-double bond leads to the 5α,6α-bromonium ion XV, which is cleaved with 5(O)n participation of the 19-methoxyl group to the cyclic ether XVI, the latter being converted to the 19-hydroxy derivative XVII by treatment with zinc and acetic acid. The 5β-hydroxy group was introduced by hypobromous acid addition to the 5,6-unsaturated 19-formate XVIII which proceeds with 6(O)π,n participation of the formate group (XVIII → XIX → XX).
Synthesis of 3,4-, 4,5- and 5,6-unsaturated 19-substituted cholestane derivatives and related epoxides
Authors: Kočovský Pavel
Published: January 2014

Starting from the 5,6-unsaturated compound X, 19-hydroxy-, 19-methoxy and 19-acetoxy derivatives with the double bond in positions 5,6- (XIV-XVI), 4,5- (XXI-XXIII) and 3,4- (XXX, XXXIII, XXXIV) were prepared by stepwise transposition of the 5,6-double bond. The route to 4,5-unsaturated steroids involves hypobromous acid addition (XVI → XVIII) followed by reductive removal of bromine and dehydration (XIX → XXI), Transposition of the 4,5-double bond to the 3,4-position is based on the conversion of the 4,5-olefin into 4β-alcohol (XXIII → XXVII) and pyrolysis of its benzoate (XXVIII → XXX).
Participation of 19-substituents in electrophilic additions. influence of 3β-substitution on hypobromous acid addition to 5,6-unsaturated steroids
Authors: Kočovský Pavel , Černý Václav
Published: January 2014

Reactions of 19-hydroxy-, methoxy- and acetoxy-5-cholestenes Ia, IIa, IIIa were studied and compared with those previously obtained with analogous 3β-acetoxy-19-substituted 5-cholestenes Ib, IIb, IIIc. A marked difference was found in 19-acetoxy derivatives where the 3-unsubstituted compound IIIa yields exclusively the bromohydrin XVIa as a product of 6(O)π,n participation while the 3β-acetoxy derivative IIIb gives, apart from the analogous bromohydrin XVIb, also products of competing reactions: The epoxide XIIb and the bromohydrin XIIIb.
Excess thermodynamic functions of kihara-molecule mixtures from the simple perturbation theory
Authors: Lago Santiago , Boublík Tomáš
Published: January 2014

Theoretical relations for excess properties, ΔGE and ΔHE, of liquid mixtures whose molecules are representable by convex bodies, were derived from Boublík's perturbation theory and semiempirical equations for the pair distribution function of a reference system. A non-spherical Kihara potential is considered and the thickness of representative bodies is determined from a generalized Barker-Henderson's theory. Computed results for binary mixtures N2 + Ar, N2 + O2, N2 + CH4 and benzene-cyclohexane are in reasonable agreement with experiment.
Determination of heats of vaporization and some other thermodynamic quantities for several fluorinated halogen derivatives of ethane and propane
Authors: Majer Vladimír , Svoboda Václav , Pošta Antonín , Pick Jiří
Published: January 2014

Some physico-chemical properties were determined for 1,1,1-trichlorotrifluoroethane, 1,1,2-trichlorotrifluoroethane, 1-bromo-1-chloro-2,2,2-trifluoroethane and 1,2-dichlorohexafluoropropane. For all the substances, their heats of vaporization in dependence on temperature were measured and their densities and refractive indices at two temperatures were determined. For 1,1,1-trichlorotrifluoroethane and 1,2-dichlorohexafluoropropane the saturated vapour pressures were measured, too. The temperature dependences of standard heats of vaporization, vaporization internal energies and cohesive energies were determined on the basis of the experimental data.
Conditions of formation of alkali hydrogenphosphites
Authors: Lukeš Ivan , Ebert Miroslav
Published: January 2014

The Filippov's eutonic method was applied to the study of M2HPO3-H3PO3-H2O heterogeneous systems (M = Li, Na, K) at 25 °C. The values of the standard Gibbs energy changes for the reactions occurring in these systems were obtained. The highest changes in the Gibbs energy accompany the formation of hydrogenphosphites M(H2PO3), the energy increases from Li to K and decreases from hydrogenphosphite to tris(orthophosphite) and bis(orthophosphite).
Mass transfer in single phase flow through fixed and fluidised beds
Authors: Kolář Václav , Červenka Jan , Brož Zdeněk
Published: January 2014

The analysis of the mass transfer mechanism in single phase flow through fixed and fluidised beds is based on the formely published theoretical model and experimental data from literature. The data in the range 5 < Re < 15 000, 0.6 < Sc < 13 000 and 0.35 ⪬ e ⪬ 0.94 have been used. The resulting relations are presented.
Liquid side mass transfer coefficient and interfacial area at vertical liquid flow on expended metal sheet packing
Authors: Brož Zdeněk , Endršt Mirko
Published: January 2014

Prediction of the liquid side mass transfer coefficient k1 at vertical liquid flow on the expanded metal packing is based on the penetration model according to Higbie. The experimental value of mass transfer coefficient k1 at absorption of sparingly soluble gases with differing diffusivities in water (propane, carbon dioxide and helium) are in a good agreement with the predicted values in a wide range of linear wetting densities. Interfacial area is determined by the chemical method and is correlated by an empirical relation.
2-styrylbenzoxazole derivatives
Authors: Arient Josef
Published: January 2014

A series of 35 derivatives of 2-styrylbenzoxazole I-XXXV with methyl, chloro, hydroxy, methoxy, dimethylamino, nitro, cyano and methoxycarbonyl substituents have been prepared by reaction of substituted 2-acetamidophenol with respective benzaldehyde derivatives.
Potential metabolites of the neuroleptic agent chlorprothixene; synthesis and pharmacology of the 3-, 4-, 6- and 7-hydroxy and methoxy derivatives of 2-chloro-9-(3-dimethylaminopropylidene)-thioxanthenes
Authors: Šindelář Karel , Jílek Jiří , Körbl Jiří , Jančik Fedir , Svátek Emil , Metyšová Jiřina , Protiva Miroslav
Published: January 2014

Cyclization of the acids IV-VII with sulfuric or polyphosphoric acid resulted in the thioxanthones VIIIa-d which were treated with 3-dimethylaminopropylmagnesium chloride and gave the amino alcohols Xa-d. Their acid catalyzed dehydrations afforded the methoxy derivatives of chlorprothixene IIIa-d, mostly in form of mixtures of geometric isomers. Whereas the results of attempts to demethylate these products with boron tribromide gave mostly unsatisfactory results, the demethylation with pyridine hydrochloride at 190-200 °C was successful; alcohols X were the most suitable starting materials. In this manner, the hydroxy derivatives of chloroprothixene IIa-d were obtained, mostly as pure geometric isomers. The configuration was assigned on the basis of their IR spectra. Z-Isomers are potential metabolites of the neuroleptic agent chlorprothixene (I). Compounds II and III are little toxic, have low central depressant activity and are inactive cataleptically.
Tricyclic potential neuroleptics: 2-chloro-11-[4-(4-fluoroaralkyl)piperazino]-10,11-dihydrodibenzo[b,f]thiepins and related compounds
Authors: Bártl Václav , Dlabač Antonín , Protiva Miroslav
Published: January 2014

Alkylation of 1-ethoxycarbonylpiperazine with 4-fluorobenzyl bromide, 2-(4-fluorophenyl)ethyl bromide and 4,4-bis(4-fluorophenyl)butyl bromide gave the carbamates IIa, IIb and IIf. Two further similar compounds (IIc, IId) were obtained by reactions of 1-(2-chloroethyl)-4-ethoxycarbonylpiperazine with 4-fluorophenol, and with 4-fluorothiophenol, respectively. Hydrolysis of carbamates IIa-f resulted in piperazine derivatives IIIa-f affording the title compounds by substitution reactions with 2,11-dichloro-10,11-dihydrodibenzo[b,f]thiepin. Out of the compounds prepared only the fluorophenethyl derivative Ib and the fluorobenzoylpropyl derivative Ie maintain the neuroleptic character, i.e. clear central depressant and cataleptic activity.
Participation of 19-substituents in acid cleavage of steroidal 5α,6α-epoxides
Authors: Kočovský Pavel , Černý Václav
Published: January 2014

Participation of the 19-methoxy and 19-acetoxy group in 5α,6α-epoxides IIIa and IVa on treatment with aqueous perchloric acid is investigated and compared with acid cleavage of previously studied 3β-acetoxy epoxides IIIb and IVb. The methoxy group in IIIa participates by a 5(O)n process. The participation is predominant on treatment with perchloric acid but is completely suppressed by the attack of an external nucleophile on treatment with hydrobromic acid. The acetoxy group in IVa participates by a 6(O)π,n process. Participation is predominant on treatment with perchloric acid and is only partially suppressed by a competitive external nucleophile attack on the action of hydrobromic acid. This behavior constitutes a difference to the 3β-acetoxy derivative IVb where hydrobromic acid completely suppresses the participation in favor of an external attack.
Participation of 19-substituents in acid cleavage of steroidal 3α,4α- and 4α,5α-epoxides
Authors: Kočovský Pavel , Černý Václav
Published: January 2014

Participation of the 19-methoxy and 19-acetoxy group in 3α,4α- and 4α,5α-epoxides IIIc, IVb,c on treatment with aqueous perchloric or hydrobromic acid is investigated and compared with acid treatment of structurally similar 19-substituted 6α,7α- and 5α,6α-epoxides V and VI and with the behavior of analogous 3α,4α- and 4α,5α-bromonium ions. The 3α,4α-epoxides III react readily with 5(O)n participation. The reaction is practically quantitative on perchloric acid treatment. Under the same conditions, the 19-methoxy-4α,5α-epoxide IVb suffers mainly external attack leading to the diol XIb. The neighboring group participation is solely a 5(O)n process giving rise to the cyclic ether X. The 19-acetoxy-4α,5α-epoxide IVc reacts predominantly with participation of the ambident acetoxy group. This reaction is exclusively a 6(O)π,n process affording the diol XVI. External attack proceeds to a limited extent to give the isomeric diol XIc. In this respect the latter compounds react quite analogously to 5α,6α-epoxides VI and 4α,5α- and 5α,6α-bromonium ions bearing 19-acetoxyl.
Effect of adenosine nucleolipids on the activity of rabbit skeletal muscle protein kinase
Authors: Hynie Sixtus , Smrt Jiří
Published: January 2014

The inhibitory effects of adenosine 5'-phosphate esters with lipoid hydroxy compounds on rabbit skeletal muscle protein kinase are in comparison with adenosine or adenosine 5'-monophosphate relatively weak. The inhibitory effect is in some cases preceded by the enzyme stimulation which can reach up to 70-80% of the stimulation by cyclic AMP. While the inhibitory effect seems to be caused by the adenosine moiety of the compound, the nature of the stimulatory effect is not yet elucidated.
Preparation, antibacterial effects and enzymatic degradation of 5-fluorouracil nucleosides
Authors: Schwarz Beatrice , Cech Dieter , Holý Antonín , Škoda Jan
Published: January 2014

Reaction of perbenzoylated aldopentafuranosyl derivatives of uracil with fluorine in acetic acid afforded perbenzoylated 5-fluorouracil nucleosides. Their methanolysis gave the following free nucleosides of 5-fluorouracil: β-D-ribofuranoside (Id), 2-deoxy-β-D-ribofuranoside (IId), their enantiomers VIII and IX, α-D-ribofuranoside (XIII), 2-deoxy-α-D-ribofuranoside (XV), β-D-arabinofuranoside (IV) and its L-enantiomer X, β-D-xylofuranoside (V) and its α-D-anomer XI, α-L-lyxofuranoside (VI) and 2-deoxy-α-L-lyxofuranoside (VII) and the enantiomers of the latter two compounds, XII and XIV, respectively. Analogously were obtained 5-deoxy-β-D-ribofuranoside (III), β-D-ribopyranoside (XVI) and 1-(S)-(2,3-dihydroxypropyl)-5-fluorouracil (XVIIc). 1-Allyl-5-fluorouracil (XVIII) was prepared by reaction of allyl bromide with 2,4-bis(trimethylsilyloxy)-5-fluoropyrimidine. The cell-free extract from Escherichia coli cleaves all the 5-fluorouracil nucleosides in which the nucleoside carbon atom has the R-configuration and the 3'-hydroxyl of the sugar moiety is in trans-relation to the base. Compounds which have not these structural features are resistant. Besides nucleosides which on enzymatic cleavage afford 5-fluorouracil, also the non-cleavable 1-(2-deoxy-β-L-ribofuranosyl)-5-fluorouracil (IX), 1-(2-deoxy-α-D-ribofuranosyl)-5-fluorouracil (XV) and 1-(2-deoxy-α-D-lyxofuranosyl)-5-fluorouracil (XIV) exhibit an antibacterial effect towards E. coli (ID50 1.0-2.5 . 10-5 M). This effect can be reversed by 2'-deoxyuridine but not by thymidine.
Heats of vaporization of alkyl esters of formic, acetic and propionic acids
Authors: Svoboda Václav , Uchytilová Věra , Majer Vladimír , Pick Jiří
Published: January 2014

Heats of vaporization of ethyl, propyl, butyl esters of formic acid, methyl, ethyl, propyl and butyl esters of acetic acid and methyl, ethyl and propyl esters of propionic acid were measured. These measurements reassume and complete data known from the literature. From the combination of values of heats of vaporization, the cohesive and vaporization internal energies of the set investigated were computed in the dependence on temperature.
Relation between the activity of electrodes from various carbonaceous meterials for reduction of oxygen to hydrogen peroxide and concentration of their paramagnetic centers
Authors: Balej Jan , Balogh Karel , Stopka Pavel , Špalek Otomar
Published: January 2014

The current yield of hydrogen peroxide during cathodic readuction of oxygen in porous electrodes from various carbonaceous materials is the lower the higher is the number of paramagnetic centers in these materials. A substantial decrease in the concentration of paramagnetic centers by heating to 900 °C in vacuum is only temporary, whereas by heating with alkali metal sulphides it is practically permanent.
Mechanism of formation of peroxomonosulphuric acid during electrolytic preparation of peroxodisulphates
Authors: Balej Jan , Thumová Milada , Kadeřávek Martin
Published: January 2014

The content of peroxomonosulphuric acid in the anolyte flowing out from a continual flow-through laboratory electrolyser for the preparation of concentrated ammonium peroxodisulphate solutions was always lower than would correspond to its rate of formation by spontaneous hydrolysis of S2O82- ions in acid medium. Hence, peroxomonosulphuric acid is formed during electrosynthesis of peroxodisulphates only by reactions taking place also in hydrolysis of S2O82- ions. The formation of peroxomonosulphuric acid by direct anodic discharge of HSO4- ions is improbable. A modified mechanism of the formation of H2SO5 either during hydrolysis or during electrolytic manufacture of peroxodisulphates is proposed.
Distinguishing between outer-sphere and inner-sphere redox mechanism on the basis of the solvent effect
Authors: Treindl Ľudovít , Adamčíková Ľubica
Published: January 2014

During kinetic studies of redox reactions of U3+ ions, we paid special attention to the influence of water-alcohol binary mixtures on the reaction rate. Kinetic data suggest that the water-tert-butanol system is of a high diagnostic value. The dependence of log kexp on the molar fraction of tert-butanol passes through a characteristic minimum in the case of an outer-sphere mechanism, whereas in the other case it decreases monotonously.
Reactions of gallocyanine methyl ester with vanadates and molybdates
Authors: Kotouček Milan , Barešová Marie , Son Nguyen Truong
Published: January 2014

Reactions of gallocyanine methyl ester with vanadates and molybdates were examined spectrophotometrically in weakly acidic solutions in 10% (m/m) ethanol. Vanadates form the VO2L2, VO2(OH)L, and VO3L complexes at pH 3-6.5, molybdates form the MoO2L2 and MoO3L complexes at pH 1.5-4.4 and pH 3-5.3, respectively. The equilibrium constants of the systems concerned were calculated from the data of the concentration curves. Use has been made of the formation of the MoO2L2 complex for photometric determination of molybdenum.
Determination of trace amounts of cobalt by homogeneous isotope exchange in an organic phase
Authors: Jiránek Václav
Published: January 2014

A new radiochemical method for determining trace amounts of cobalt has been worked out. It is based on a homogeneous isotope exchange between cobalt(III) diethyldithiocarbamate and cobalt(III) caprate in an organic phase. The method, tested in the range 0.005-8 μg Co, has proved to be selective.
The effect of electrondonors on the polymerization kinetics of isoprene
Authors: Kašpar Miroslav , Trekoval Jiří
Published: January 2014

The effect of small additions of 1-octene, butyl ethyl ether and triethylamine on the polymerization kinetics of isoprene (2-methyl-1,3-butadiene) in benzene initiated with butyllithium was investigated by employing the GLC analysis. The addition of 1-octane was reflected only in a shorter induction period of the reaction; the effect on the propagation rate was insignificant. With the increasing amount of butyl ethyl ether, the polymerization rate increases linearly, while the reaction order with respect to the concentration of triethylamine is variable and increases from 0.33 to 0.66 with the increasing concentration of the initiator. For a constant concentration of triethylamine, the reaction order with respect to the initial concentration of the initiator was found to vary considerably, reaching even negative values. A reaction scheme was suggested, taking into account the competition between two different solvates of alkyllithium.
Electron transfer processes. reactions of 5-nitrofuryl derivatives going by anionradical mechanism
Authors: Prousek Josef
Published: January 2014

5-Nitrofurfuryl nitrate and bromide (Ia,b) react with electron donors to give 1,2-bis(5-nitro-2-furyl)ethane (II), 1,2-bis(5-nitro-2-furyl)ethylene (III), 5-nitro-2-methylfurane (IV), products of SRN1 reactions Va, Vb and other derivatives. Formation of the derivatives II to V is discussed on the basis of anionradical mechanism. 4-Nitrobenzyl bromide reacts by a SRN1 reaction with 5-nitrofurfuryl phenyl sulphone (Va) in basic medium to give 1-(5-nitro-2-furyl)-1-phenylsulphonyl-2-(4-nitrophenyl)ethane (VIII) and 1-(5-nitro-2-furyl)-2-(4-nitrophenyl)ethylene (IX).
Anionic cis-trans isomerisation of dimethyl perfluoro-(4-methyl-2-pentene)dioate
Authors: Paleta Oldřich , Svoboda Jiří , Havlů Václav , Dědek Václav
Published: January 2014

Potassium fluoride induced cis-trans isomerisation of the title compound I was investigated. The isomerisation takes place in a heterogeneous system and is enabled by solvation effect of dipolar aprotic solvents. Dimethyl 2,3,3,4-tetrafluoro-2-trifluoromethylpentanedioate (II) is formed as side product by proton transfer from the solvent to the intermediate 1,3-bis(methoxycarbonyl)perfluoro-1-butanide (III). The mechanism was deduced from the reaction conditions and results of the isomerisation. Composition of the equilibrium mixture of cis- and trans-isomer (Ia, Ib, respectively) studied in the interval 2-75 °C, shows an extreme. In the interval 2-30 °C the reaction Ia → Ib appears to be exothermic (ΔH = -21.2 kJ mol-1), in the interval 35-47 °C the enthalpy equals practically zero and in the maximum of the curve at 42.5 °C the entropic factor ΔS = 2.82 J mol-1 K-1. In the interval 50-75 °C the reaction is endothermic (ΔH = 15.2 kJ mol-1). In this context the effect of steric interactions between the substituents -COOCH3 and -CF(CF3)COOCH3, as well as of the so called cis-effect in 1,2-dihalogenoethylenes, on the Ia ##e Ib equilibrium are discussed.
Kinetics of catalytic conversion of methanol at higher pressures
Authors: Bartoň Jaroslav , Pour Vladimír
Published: January 2014

The course of the conversion of methanol with water vapour was followed on a low-temperature Cu-Zn-Cr-Al catalyst at pressures of 0.2 and 0.6 MPa. The kinetic data were evaluated together with those obtained at 0.1 MPa and the following equation for the reaction kinetics at the given conditions was derived: r = [p(CH3OH)p(H2O)]0.5[p(H2)]-1.3.
Reactions of bases of nucleic acids with mercury electrode. anodic pulse-polarographic currents of pyrimidine bases and their derivatives
Authors: Paleček Emil , Jelen František , Manoušek Osvald
Published: January 2014

Anodic currents of pyrimidine bases were studied by using differential and normal pulse polarography, cyclic voltammetry, and classical polarography in alkaline medium. All pyrimidine bases occurring usually in nucleic acids (cytosine, uracil, thymine, 5-methylcytosine, and hydroxymethylcytosine) gave anodic DPP peaks, NPP and d.c. polarographic waves at potentials close to 0 V due to the formation of sparingly soluble salts with mercury. Nucleosides and nucleotides derived from cytosine, uracil, and thymine were inactive. The mentioned bases and other pyrimidine derivatives (isocytosine, uracil-5-carboxylic acid, uracil-6-carboxylic acid (orotic acid), 2-amino-4,6-dioxypyrimidine, 2-amino-4,6-dioxy-5-methylpyrimidine, 4-amino-2,6-dioxy-pyrimidine, and 5-amino-2,4-dioxypyrimidine) gave anodic peaks and cathodic stripping peaks during reversal of the potential sweep on a hanging drop electrode, whereas 2-aminopyrimidine and 2-hydroxypyrimidine were inactive; the concentrations used were 5 . 10-6 - 5 . 10-5M. The bahaviour of cytosine, uracil, and thymine in DPP and NPP was studied at various concentrations of the bases, pH values, pulse amplitudes, etc. Differences between the behaviour of uracil and thymine were large at higher concentrations at which the electrode surface was fully covered, and they were explained on the assumption of a different adsorption behaviour of these compounds and a large tendency of uracil to form a film on the electrode.
Reaction of nucleic acid bases with the mercury electrode: determination of submicromolar concentrations of pyrimidine bases by means of cathodic stripping voltammetry
Authors: Paleček Emil , Jelen František
Published: January 2014

Pyrimidine bases commonly occurring in nucleic acids i.e. cytosine, uracil and thymine and further pyrimidine derivatives such as 5-methylcytosine, 5-hydroxymethylcytosine, isocytosine, uracil-6-carboxylic acid (orotic acid), 5-amino-2,4-dioxypyrimidine, 2-amino-4,6-dioxypyrimidine and 4-amino-2,6-dioxypyrimidine and thio derivatives and halogen derivatives of uracil and cytosine were analyzed by means of cathodic stripping voltammetry (CSV). As compared with most of the sulphur-containing substances the deposition potential optima of the pyrimidine derivatives (not containing sulphur) were substantially narrower and shifted to more positive potentials. Cytosine, thymine and uracil can be determined by means of differential pulse CSV at concentrations of the order of magnitude 10-7 - 10-8 mol/l. Nucleosides and nucleotides derived from the pyrimidine bases are inactive and do not substantially interfere with the determination of bases. Bases can be determined even in an excess of DNA and proteins.
Catalytic activity of copper oxides and chlorides in the redox chain addition of tetrachloromethane to styrene
Authors: Hájek Milan , Šilhavý Přemysl , Málek Jaroslav
Published: January 2014

The catalytic activity of redox systems based on copper oxide or chloride and diethylamine (DEA) in the addition of tetrachloromethane to styrene at 76 °C increases in the order CuO-DEA < Cu2O-DEA < CuCl2-DEA ~ CuCl-DEA ##i CuCl.2 DEA. Reactions catalysed by systems Cu2O-DEA and CuO-DEA display significant induction periods which decrease with increasing DEA concentration. The dependence of reaction rates on the concentration of DEA indicates formation of the CuCl.2 DEA complex. Inhibition method was used to estimate the rate of the initiating step in the addition reaction catalysed by CuO-DEA.
Protonation-induced variability of electronic effects of silyl and germyl substituents in α-carbofunctional derivatives
Authors: Dejmek Luboš , Ponec Robert , Chvalovský Václav
Published: January 2014

On the basis of Fourier analysis of internal rotation curves for α-carbofunctional derivatives of Group IVb elements the effect of protonation of parent molecules on the nature of electronic effects of methyl, silyl and germyl substituents is discussed.
Hydrogenation and isomerisation of unsaturated compounds on a palladium catalyst
Authors: Červený Libor , Lövyová Alena , Růžička Vlastimil
Published: January 2014

Catalytic hydrogenation and simultaneous isomerisation of 1- and 2-hexene and of three unsaturated alcohols was studied under normal conditions on a palladium catalyst. The effect of solvents and of substrate structure on the course of this reaction is reported. The structure of the starting compound was found to have dominant effect on the selectivity of hydrogenation while solvents influenced significantly the reaction rate and selectivity of competition reactions of 1-hexene and unsaturated alcohols.
Some ω-(2-amino-6-hydroxy-4-oxo-3,4-dihydro-5-pyrimidinyl) alkanoic acids, their derivatives and analogues
Authors: Semonský Miroslav , Černý Antonín , Křepelka Jiří , Kotva Rudolf , Kakáč Bohumil , Holubek Jiří , Vachek Jaroslav
Published: January 2014

Condensation of 1,1,ω-alkanetricarboxylic acids triethyl esters XIV-XXI with guanidine gave ω-(2-amino-6-hydroxy-4-oxo-3,4-dihydro-5-pyrimidinyl) alkanoic acids I-IV, VI-VIII, XIII of which some were converted to derivatives (ethyl ester V, N-acyl derivatives XI and XII). Similarly, triester XVII gave by condensation with urea or thiourea the analogous 5-substituted derivatives of barbituric acid X, and thiobarbituric acid IX, respectively. The structures of selected compounds of this group (IV, V, IX-XI and XIII) were determined by spectral methods. Of interest, from the pharmacological point of view, has proved compound IV, which exhibited a significant antineoplastic effect on some experimental tumours in mice and rats, and enhanced the action of some current cytostatics.
Disease status, patient quality of life and healthcare resource use for ulcerative colitis in the UK: an observational study
Authors: Vaizey Carolynne J , Gibson Peter R , Black Christopher M , Nicholls Rebecca J , Weston Adèle R , Gaya Daniel R , Sebastian Shaji , Shaw Ian , Lewis Stephen , Bloom Stuart , Gordon John N , Beale Amanda , Arnott Ian , Campbell Simon , Fan Tao
Published: January 2014

Background

Ulcerative colitis is a lifelong, chronic, relapsing-remitting disease.

Objective

To assess the relationship between ulcerative colitis disease status and patient quality of life, and to determine the impact of ulcerative colitis on healthcare costs and work productivity, in the UK.

Methods

Clinicians assessed 173 adult patients’ current disease status at a single study visit using the partial Mayo (pMayo) instrument. Patients completed the Euro Quality of Life 5-dimension, 5-level (EQ-5D-5L) questionnaire, the Work Productivity and Activity Impairment (WPAI) questionnaire. Healthcare resource use was determined from questionnaires and from patients’ medical charts.

Results

Patients in remission had a significantly higher EQ-5D-5L scores (mean (SD) 0.86 (0.15)) than patients with active disease (0.71 (0.20); p<0.001). Patients with mild disease had significantly higher mean (SD) EQ-5D-5L scores than patients with moderate/severe disease: 0.77 (0.11) and 0.66 (0.24), respectively (p<0.001). The mean percent productivity impairment was greater for patients with active disease than for patients in remission on all items of the WPAI questionnaire: 24.6% vs 1.8% for work time missed, 34.1% vs 12.9% for impairment while working, 40.8% vs 14.4% for overall work impairment and 42.7% vs 13.0% for activity impairment (p<0.001 for all comparisons). The mean (SD) total cost of healthcare for ulcerative colitis in the prior 3 months was £1211 (1588).

Conclusions

When compared with patients in remission, patients with active ulcerative colitis have significantly worse quality of life and significantly more work impairment. The healthcare costs of ulcerative colitis are considerable.
Expression of EpCAMMFand EpCAMMTvariants in human carcinomas
Authors: Fong Dominic , Seeber Andreas , Terracciano Luigi , Kasal Armin , Mazzoleni Guido , Lehne Florian , Gastl Guenther , Spizzo Gilbert
Published: January 2014

Aims

Regulated intramembrane proteolysis has been shown to be an important mechanism for oncogenic activation of epithelial cell adhesion molecule (EpCAM) through nuclear translocation of the intracellular domain EpICD. Recent studies have identified new membrane-bound EpCAM variants. To evaluate the prevalence of two membranous EpCAM variants in human tumours, we performed a large-scale expression analysis using specific antibodies against the extracellular domain EpEX (MOC-31 clone) and the intracellular domain EpICD (9-2 clone) of the EpCAM antigen by immunohistochemistry.

Material and methods

Two multi-tissue microarrays (TMA) series containing 1564 tissue samples each of 53 different histological tumour types were stained and compared. One TMA was stained for EpEX and one for EpICD. Membranous full-length EpCAM (EpCAMMF) expression in tissues was defined by the expression of EpEX and EpICD, while the truncated variant of EpCAM (EpCAMMT) was characterised by a significant loss of membranous EpICD expression compared with EpEX expression.

Results

We defined tumours with high EpCAMMTexpression (ie, cancers of the endometrium and bladder), tumours with intermediate (ie, gastric, pancreatic, colorectal and oesophageal cancer) and tumours with low rates of expression of the EpCAMMTvariant (ie, lung, ovarian, gallbladder, breast and prostate cancer).

Conclusions

Our results indicate that loss of membranous EpICD expression is a common event in human epithelial carcinomas, arguing for the expression of different degrees of EpCAMMFand EpCAMMTvariants across the most important tumour entities. Future studies evaluating the prognostic and predictive role of these variants in human malignancies, especially in patients treated with EpCAM-specific antibodies, are clearly warranted.
Young men and the morning after: a missed opportunity for emergency contraception provision?
Authors: Schrager Sheree M , Olson Johanna , Beharry Meera , Belzer Marvin , Goldsich Katherine , Desai Mona , Clark Leslie F
Published: January 2014

Objectives

Although adolescents and young adults of lower socioeconomic status (SES) are disproportionately affected by unintended pregnancies, research on experiences with emergency contraception (EC) in this population has lagged. Furthermore, it is unclear whether EC-related knowledge and behaviour varies between young men and women. This study investigated knowledge, attitudes and experiences with EC among low SES young men and women aged 18–25 years.

Methods

One hundred and ninety-eight new enrollees at two Los Angeles primary medical care clinics completed surveys about their knowledge, past use and likelihood of using EC. Chi square (χ2) and regression analyses assessed gender differences in knowledge and attitudes.

Results

Women were more likely than men to accurately answer questions about EC and its use. Across both sexes, accurate knowledge predicted future willingness to use EC. Only half the women and a third of men knew that EC could be directly dispensed by pharmacists; even fewer knew that the legal access age for EC was 17 years (13%) or that men could access EC from pharmacies for their female partners (24%). Although respondents most commonly reported that friends were their source of current information about EC, both men and women chose health care professionals as their desired source of future information about EC.

Conclusions

Young men in this sample were significantly less knowledgeable than young women about EC. Educating young men about EC by health care providers during routine visits may be a unique opportunity to increase EC knowledge, access and use among low-income young couples to decrease undesired pregnancies.
Contraceptive use among women presenting to pharmacies for emergency contraception: an opportunity for intervention
Authors: Michie Lucy , Cameron Sharon T , Glasier Anna , Greed Elizabeth
Published: January 2014

Objectives

Most women who use emergency contraception (EC) do so because of unprotected sexual intercourse or condom failure and so remain at risk of pregnancy unless they commence an effective method of contraception. In Great Britain, increasingly women now choose to obtain EC from a pharmacy; however, pharmacists do not currently provide effective ongoing contraception. We sought to determine the views of women obtaining EC from pharmacies and clinicians working in sexual and reproductive health care (SRH) about the possibility of pharmacists providing a temporary supply of a progestogen-only pill (POP) together with EC.

Methods

Self-administered, anonymous questionnaires of (1) women requesting EC from pharmacies in Edinburgh, Scotland and (2) SRH clinicians attending a major UK scientific meeting.

Results

A total of 211/232 women completed questionnaires in pharmacies (a 91% response rate). Of those women not using a hormonal method of contraception at the time of EC (n=166; 79%), almost half (44%) wished to use an effective method. Most women (64%) agreed that the option of a pharmacist being able to supply a POP would have been helpful. Among the SRH clinicians, 110 completed questionnaires out of 150 distributed (a 73% response rate). The majority of respondents (92%) were positive about a pharmacist supplying a POP at the time of EC.

Conclusions

A reasonable proportion of women requesting EC would like to start using an effective contraceptive method. Both the women and the SRH clinicians we surveyed are positive about the option of a short supply of a POP being provided by the pharmacy in the UK together with EC.
Primary blast lung injury at a NATO Role 3 hospital
Authors: Aboudara Matthew , Mahoney P F , Hicks B , Cuadrado D
Published: January 2014

Background

Primary blast lung injury (PBLI) is defined as lung contusion from barotrauma following an explosive mechanism of injury (MOI). Military data have focused on PBLI characteristics following evacuation from the combat theatre; less is known about its immediate management and epidemiology in the deployed setting. We conducted a quality improvement project to describe the prevalence, clinical characteristics, management strategies and evacuation techniques for PBLI patients prior to evacuation.

Methods

Patients admitted to a Role 3 hospital in southwest, Afghanistan, from January 2008 to March 2013 with a blast MOI were identified through the Department of Defense Trauma Registry; International Classification of Diseases 9 codes and patient record review were used to identify the PBLI cohort from radiology reports. Descriptive statistics and Fishers exact test were used to report findings.

Results

Prevalence of PBLI among blast injured patients with radiology reports was 11.2% (73/648). The population exhibited high Injury Severity Scores median 25 (IQR 14–34) and most received a massive blood transfusion (mean 33.4±38.3 total blood products/24 h). The mean positive end expiratory pressure (PEEP) requirement was 6.2±3.7 (range 5–15) cm H2O and PaO2to FiO2ratio was 297±175.2 (66–796) mm Hg. However, 16.6% of patients had a PaO2to FiO2ratio <200, 13.3% required PEEP ≥10 cm H2O and one patient required specialised evacuation for respiratory failure. A dismounted MOI (72.8%) and evacuation from point of injury by the Medical Emergency Response Team (62.3%) appeared to be associated with worse lung injury. Only eight of the 73 PBLI patients died and of the five with retrievable records, none died from respiratory failure.

Conclusions

PBLI has a low prevalence and conventional lung protective ventilator management is generally appropriate immediately after injury; application of advanced modes of ventilation and specialised evacuation assistance may be required. PBLI may be a marker of underlying injury severity since all deaths were not due to respiratory failure. Further work is needed to determine exact MOI in mounted and dismounted casualties.
Translational research to improve the treatment of severe extremity injuries
Authors: Brown Kate V , Penn-Barwell J G , Rand B C , Wenke J C
Published: January 2014

Objectives

Severe extremity injuries are the most significant injury sustained in combat wounds. Despite optimal clinical management, non-union and infection remain common complications. In a concerted effort to dovetail research efforts, there has been a collaboration between the UK and USA, with British military surgeons conducting translational studies under the auspices of the US Institute of Surgical Research. This paper describes 3 years of work.

Methods

A variety of studies were conducted using, and developing, a previously validated rat femur critical-sized defect model. Timing of surgical debridement and irrigation, different types of irrigants and different means of delivery of antibiotic and growth factors for infection control and to promote bone healing were investigated.

Results

Early debridement and irrigation were independently shown to reduce infection. Normal saline was the most optimal irrigant, superior to disinfectant solutions. A biodegradable gel demonstrated superior antibiotic delivery capabilities than standard polymethylmethacrylate beads. A polyurethane scaffold was shown to have the ability to deliver both antibiotics and growth factors.

Discussion

The importance of early transit times to Role 3 capabilities for definitive surgical care has been underlined. Novel and superior methods of antibiotic and growth factor delivery, compared with current clinical standards of care, have been shown. There is the potential for translation to clinical studies to promote infection control and bone healing in these devastating injuries.
Empathy and integrative thinking: Talmudic paradigms for the essentials of a medical interview
Authors: Davidson John H
Published: January 2014

Intentional empathy and integrative thinking are essential elements of a medical interview. Yet the repetitive, sometimes monotonous, nature of medical practice can compromise their achievement. Emotional and intellectual fatigue may lead to clouded observation with diagnostic errors resulting. In spite of a long extant pedagogy of teaching interviewing techniques and creative mnemonics, hurdles remain and significant miscues continue. The challenge is one of surmounting these obstacles and of finding ‘new’ ways to perform ‘old’ tasks. It is to do what we already know to do but somehow do not. In the essay which follows, two Talmudic legends are identified and discussed as paradigms for empathy and integrative thinking. They are offered as ‘literary mnemonics’ for potential use in physician–patient encounters. The legends are linked to the insights of contemporary scholars including Jerome Groopman, Danielle Ofri, Roger Martin and others who have considered concepts of cognition, emotion, empathy, ‘opposable mind’ and integrative thinking in medical and non-medical settings.
Contrast-enhanced time-resolved MRA for pre-angiographic evaluation of suspected spinal dural arterial venous fistulas
Authors: Saindane Amit M , Boddu Srikanth R , Tong Frank C , Dehkharghani Seena , Dion Jacques E
Published: January 2014

Background

Spinal digital subtraction angiography (DSA) is the gold standard for diagnosis of spinal dural arterial venous fistulas (SDAVFs), but can require extensive time, radiation exposure and contrast dose. We hypothesize that contrast-enhanced time-resolved MR angiography (CE-TR MRA) will have utility for the non-invasive diagnosis and pre-angiographic localization of SDAVFs.

Methods

Eighteen patients underwent both CE-TR MRA and DSA for suspected SDAVFs, with DSA performed a median of 11 days (range 0–41) after MRA. CE-TR MRA was performed on a 1.5 T GE unit using Time Resolved Imaging of Contrast Kinetics (TRICKS). CE-TR MRA and DSA images were evaluated for the presence of SDAVFs and location of the feeding arterial supply, with DSA as the reference standard. DSA was also evaluated for the number of vessels catheterized, contrast volume and fluoroscopic and procedure times.

Results

Eight of the 18 patients were positive for SDAVF on DSA. Sensitivity, specificity, positive predictive value and negative predictive value for the 18 CE-TR MRAs were 88%, 90%, 88% and 90%, respectively. Localization of the SDAVF arterial supply on CE-TR MRA was within one vertebral level from DSA for 6/7 SDAVFs. Compared with patients with a SDAVF and feeding artery identified on CE-TR MRA, patients with negative or suboptimal CE-TR MRA had a significantly increased number of vessels catheterized (p=0.027) and larger contrast volumes (p=0.022).

Conclusions

CE-TR MRA is a useful initial examination for the diagnosis and localization of SDAVFs, with a high concordance rate with DSA. When CE-TR MRA demonstrates a SDAVF, the number of catheterized vessels and contrast dose can be decreased during DSA.
Mesna and furosemide for prevention of cyclophosphamide‐induced sterile haemorrhagic cystitis in dogs – a retrospective study
Authors: Laberke S. , Zenker I. , Hirschberger J.
Published: January 2014

Sterile haemorrhagic cystitis (SHC) is a possible side effect of cyclophosphamide which can severely impact quality of life. Mesna and diuresis are effective in human medicine to prevent SHC. The aim of the present study was to compare the efficacy of mesna versus diuresis with furosemide in preventing SHC in dogs treated with cyclophosphamide within a multidrug chemotherapy induction protocol for malignant lymphoma. Medical records of dogs treated at the Clinic of Small Animal Medicine, Munich, between 1997 and 2009 were analysed retrospectively. Of the 131 dogs included, 33 received no prophylaxis (group 1), 43 received mesna (group 2), and 55 received furosemide (group 3). Age, gender, breed, bodyweight, body surface area, dose and application method of cyclophosphamide, and the method of SHC prophylaxis were compared between dogs with and without SHC. Six dogs (4.6 per cent) developed SHC. The incidence of SHC in groups 1, 2 and 3 was 4/33 (12.1 per cent), 1/43 (2.3 per cent), and 1/55 (1.8 per cent), respectively. Dogs receiving either mesna or furosemide were significantly less likely to develop SHC (P=0.03). Otherwise no significant differences were found. In conclusion, this study demonstrates the efficacy and the medical indication of mesna and furosemide for prevention of cyclophosphamide‐induced SHC.