bluuebunny/crossref_metadata_2025 huggingface dataset:
Wash-out of solid phase from the mechanically stirred charge
Authors: Machoň Václav , Kudrna Vladimír , Hudcová Vlasta
Published: January 2014

Experimental measurements were performed of the time dependence of solid phase concentration in suspension at the outlet from the apparatus with the mechanically stirred charge. Suspension was being withdrawn continuously with fresh water supplied into the charge. Validity of the theoretical approach proposed earlier has been verified by the performed experiments. It has been demonstrated that the studied effect can be under certain conditions described with sufficient accuracy by a simple material balance of the solid phase in the system.
The effect of steric size of leaving group on rates of the competing syn- and anti-pathways in biomolecular elimination
Authors: Závada Jiří , Pánková Magdalena
Published: January 2014

Approximate rates of the competing syn- and anti-pathways have been determined in t-C4H9OK-t-C4H9OH promoted elimination from two homologous series of tosylates: I-OTs trans-III (R = H, CH3, C2H5, n-C3H7, i-C3H7, t-C4H9) and II-OTs trans-IV (R = CH3, C2H5, n-C3H7, i-C3H7, t-C4H9). A comparison has been made with rates of the same processes in the (+) elimination of the corresponding trimethylammonium salts I-N(CH3)3 trans-III and (+) II-N(CH3)3 trans-IV. The title effect is demonstrated by a comparative analysis of the rate patterns obtained for the two leaving groups.
Degradation of the peach gum polysaccharide by the mixture of extracellular glycanohydrolases of aspergillus flavus
Authors: Kardošová Alžbeta , Rosík Jozef , Kubala Jozef
Published: January 2014

The polysaccharide of peach gum, prepared by a partial acid hydrolysis, was degraded by a mixture of extracellular glacanohydrolases of Aspergillus flavus. This way obtained polysaccharide differed from the original one especially by a higher content of D-mannose and a lower content of D-galactose bound by (1 3) glycosidic bonds. The obtained results are discussed from the standpoint of composition of the main and side chains of the native polysaccharide.
Kinetics of reactions of acyl isothiocyanates with amines
Authors: Imrich Ján , Kristian Pavol , Podhradský Dušan , Dzurilla Milan
Published: January 2014

The kinetics of reactions of 4-substituted benzoyl, cinnamoyl and phenyl isothiocyanates with aliphatic amines and glycine ethyl ester in organic solvents was studied by the stopped-flow and UV spectroscopic methods. The reaction of acyl isothiocyanates with the nucleophilic reagents employed proved to be 103 - 104 times faster than analogous reaction of phenyl isothiocyanates. A linear correlation between logk and σp constants with positive ρ slope was found. The solvent polarity has only a negligible effect on the reaction. UV spectra as well as gas chromatography of the reaction products proved that under the employed experimental conditions N,N'-disubstituted thioureas are the sole reaction products.
Isomerization of ketolactone of oxabicyclo[2.2.2]octane pattern in the E ring of ursane derivatives
Authors: Klinotová Eva , Skorkovská Hana , Protiva Jiří , Urban Jiří , Vystrčil Alois
Published: January 2014

Alkaline hydrolysis of ketolactones I and II is accompanied by quantitative acyloin rearrangement of the 20-hydroxy-21-oxo derivative III formed, under simultaneous migration of the methyl group from the position 20α to the position 21α.
The mechanism of the anionic coordination polymerization of isoprene
Authors: Kašpar Miroslav , Trekoval Jiří
Published: January 2014

The polymerization kinetics of isoprene (2-methyl-1,3-butadiene) in benzene with butyllithium as the initiator was investigated by the gas chromatographic method. After completion of the initial period of the reaction, its order with respect to the initial concentration of initiator is negative at the concentrations of the latter between 0.01 and 0.25 mol/l, and positive at higher concentrations. A reaction scheme has been suggested with respect to the "cross" association of butyllithium and of the "living" oligoisoprene.
Dipole moment and electron distribution of the amide group
Authors: Exner Otto , Papoušková Zlata
Published: January 2014

Dipole moments of five substituted N,N-dimethylbenzamides Ia-Ie were measured in benzene and dioxan solutions. The group moment of 12.7 . 10-30 C m (at an angle of 80° to the C(1)-C bond) was resolved into components and a mesomeric moment of 4.7 . 10-30 C m (in the direction from N to C) was derived, accounting for the conjugation within the dimethylamide group. A smaller mesomeric moment in the same direction was found for the unsubstituted amide group. The results are but roughly consistent with an interpretation in terms of the mesomeric formulae A ##e B.
Topological methods of quantum chemistry for a study of chemical reactivity
Authors: Pancíř Jiří
Published: January 2014

In this paper all approximations are discussed which lead to a quantum chemical model which is adequate for structural formulas known in classical organic chemistry. Neglect of the energy differences caused by changes of valence and dihedral angles, i.e. neglect of all nonbonding interactions, leads to the separation of the Hartree-Fock matrix in blocks of core electrons, nonbonding electron pairs, two center blocks of σ-bonds and delocalized π-electronic structures. Such a procedure can be formulated at all levels of sophistication - from the one electron approximation to the MC-SCF method. Even on the one electron level, the average error in heats of atomization (35.9 kJ/mol) is lower than that of the more complicated geometrical methods MINDO/3 (52.1 kJ/mol) and MNDO (39.6 kJ/mol). The procedure suggested is about two orders of magnitude more efficient than geometrical ones of the same level and can be, therefore, used for a study of reaction mechanisms of medium size systems (30-50 atoms) without large expense.
The flow of a plastic material in ducts
Authors: Wichterle Kamil , Wein Ondřej
Published: January 2014

The kinematics and dynamics of the flow of an ideally plastic material is fully characterized by the cross section occupied by the flowing material. It will be shown that appart from the case when the flowing material occupies the total cross sectional area of the duct, nontrivial cases exist with part of the cross section occupied by a stagnant material adhering to the walls. For the calculation of pressure losses it is then usefull to characterize the cross section of the duct by the value of the maximum hydraulic radius.
Accuracy of analytical results
Authors: Eckschlager Karel , Štěpánek Vladimír
Published: January 2014

Negentropy is defined, which characterizes both the precision and the correctness of normally distributed results of quantitative analyses; its properties are discussed and its practical use is proposed in judging and optimizing analytical results.
The effect of hydrogen pressure on desulphurization of diethyl sulphide and thiophene on a cobalt-molybdenum catalyst
Authors: Maternová Jindřiška , Zdražil Miroslav
Published: January 2014

Integral kinetic data for the reaction of diethyl sulphide, thiophene and their mixture have been obtained on a Co-Mo-Al2O3 catalyst at 573 K and hydrogen pressures up to 2 MPa. In the reaction of single compounds at low hydrogen pressures and in the reaction of their mixture over the whole range of hydrogen pressures, diethyl sulphide reacts at a faster rate, compared to thiophene. However, both compounds exhibit the same reactivity in their single reactions carried out at hydrogen pressures around 2 MPa. Kinetic behaviour of intermediate products of the above reactions (ethylthiol and tetrahydrothiophene) have been examined. The results obtained lead to the following conclusions: thiophene ring is hydrogenated in the first step of the reaction, the cleavage of the C-S bond in saturated sulphides is an elimination reaction taking place without direct participation of hydrogen, and hydrodesulphurization catalysts are therefore bifunctional.
Glucosidation of 2-hydroxy- and 5-hydroxy-1,4-naphthoquinone
Authors: Steinerová Naděžda , Cudlín Josef , Vaněk Zdenko
Published: January 2014

Using the Koenigs-Knorr method two isomeric monohydroxynaphthoquinones were glucosidized, i.e. 2-hydroxy-1,4-naphthoquinone (lawson, Ia) and 5-hydroxy-1,4-naphthoquinone (juglone, IIa). The structure of the corresponding glucosides Ib and IIb was proved by 1H NMR, mass, UV, VIS and IR spectra.
Esters of 4,4-bis(4-ethylphenyl)-2,3-dibromo-2-butenoic acid and 7-ethyl-4-(4-ethylphenyl)-2,3-dibromo-1-naphthol
Authors: Křepelka Jiří , Holubek Jiří , Semonský Miroslav
Published: January 2014

Chloride of 4,4-bis(4-ethylphenyl)-2,3-dibromo-2-butenoic acid (VII), prepared in situ, reacted with aliphatic alcohols and benzyl alcohol with the formation of esters II-VI. Reaction of the chloride VII with aromatic alcohols gave 7-ethyl-4-(4'-ethylphenyl)-2,3-dibromo-1-naphthol (VIII), whose structure was corroborated by IR and 1H NMR spectra. Compounds II-VI and VIII exhibited weaker antineoplastic effects than Edikron (I).
Model of residence time distribution function in the reactor with dispersion flow and ideal mixing
Authors: Košut Jaroslav , Ilavský Ján , Dudák Martin
Published: January 2014

A function of residence time distribution is derived by the method of generalized Heaviside series and an approximative procedure for the dispersion model coupled with ideal mixing boundary conditions, for "closed-closed" reactor, were used. Model is characterized by two parameters: Peclet number and volume fraction of the region of dispersion flow. The solution is studied numerically and the advantages of the approximative solution are discussed in detail.
Preparation of derivatives of inosine 5'-phosphorothioate for use in affinity chromatography
Authors: Kois Pavol , Holý Antonín
Published: January 2014

In the paper the known methods of preparation of ribonucleoside 5'-phosphorothioates II are evaluated and an improved method of their synthesis is described, based on the reaction of 2',3'-O-ethoxymethyleneribonucleosides III with thiophosphoryl chloride in the presence of one equivalent of pyridine, and subsequent hydrolysis. Inosine 5'-phosphate and inosine 5'-phosphorothioate(IIc) were converted to 2',3'-O-cyclic ketals of levulinic acid Vb, VIb on reaction with ethyl levulinate and ethyl orthoformate and subsequent alkaline hydrolysis. O-(4-Aminophenyl)inosine 5'-phosphorothioate (IX) was prepared from 2',3'-O-isopropylideneinosine (VII) with O-(4-nitrophenyl)thiophosphoryldiimidazolide and subsequent catalytic hydrogenation of the O-(4-nitrophenyl)ester VIII formed.
Preparation of p-aminobenzyl cellulose and its utilization for immobilization of enzymes
Authors: Gemeiner Peter , Kuniak Ľudovít , Zemek Jiří
Published: January 2014

The O-alkylation of non cross-linked celluloses with p-nitrobenzyl chloride according to Campbell does not afford satisfying results (alkylation degree Da ⪬ 0.025). On the other hand, the use of cross-linked celluloses makes it possible to prepare p-nitrobenzyl cellulose under substantially milder reaction conditions (Da ⪬ 0.42); the degree of cross linking of cellulose considerably affected the Da of p-nitrobenzyl cellulose. The same also holds for O-alkylation of cross-linked celluloses with p-nitrobenzyl chloride according to Hakomori. Reduction of p-nitrobenzyl cellulose with dithionite is considerably associated with side reactions in which sulfur became embodied, whereas reduction with titanous chloride resulted in noticeable losses of p-nitrobenzyl groups. p-Aminobenzyl cellulose is, after activation with carboxyl groups, a suitable carrier for immobilization of enzymes as acetylcholinesterase, glucoamylase and α-amylase. The respective immobilized enzymes retained relatively high relative activities, in the last two cases also for high-molecular substrates.
Synthesis and pharmacological properties of oxytocin analogues modified simultaneously in position 2 and in the disulfide bridge
Authors: Lebl Michal , Barth Tomislav , Jošt Karel
Published: January 2014

Analogues of deamino-6-carba-oxytocin, containing isoleucine, O-methyltyrosine or methionine in position 2, either in the sulfide or sulfoxide form, were prepared and studied pharmacologically. These compounds had considerably lower biological activities than the analogous compounds of the 1-carba series. Furthermore, analogues of [1,6-homolanthionine]deamino-oxytocin were prepared with O-methyltyrosine or isoleucine in position 2; these compounds had a certain degree of oxytocic activity.
Synthesis and some pharmacological properties of [7-glycine, 8-ornithine]vasopressin and two of its analogues
Authors: Lebl Michal , Barth Tomislav , Škopková Jana , Jošt Karel
Published: January 2014

Protected peptides were prepared by fragment condensation according to the scheme 6 + 3 or 9 + 3, which, after the removal of the protecting groups by sodium in liquid ammonia and oxidative cyclization, afforded [7-glycine,8-ornithine]vasopressin, [7-glycine,8-ornithine]deaminovasopressin, and Nα-glycyl-glycyl-glycyl[7-glycine,8-ornithine]vasopressin. All the analogues had very low intrinsic vasopressin-like activities; the analogue with hormonogen nature had a depressor effect and inhibited the pressor action of lysine-vasopressin.
Fourier components analysis of internal rotation in carbofunctional derivatives of group iv b elements
Authors: Ponec Robert , Dejmek Luboš , Chvalovský Václav
Published: January 2014

On the basis of Fourier component analysis of internal rotation around the C-X bond in α- and β-functional derivatives of the type Y-(CH2)n-X (X = NH2, OH; Y = CH3, SiH3, GeH3; n = 1, 2) the nature of intramolecular interactions in these compounds was analysed. Electronic effects of polarisable silyl and germyl groups were found to be dramatically influenced by the molecular conformation.
Control of an adiabatic continuous reactor by feeding catalyst
Authors: Horák Josef , Valášková Zina , Jiráček František
Published: January 2014

Algorithms have been presented, analyzed and experimentally tested to stabilize the reaction temperature at constant inlet temperature and composition of the feed by controlled dispensing of the catalyst. The information for the control element is the course of the reaction temperature. If the temperature of the reaction mixture is below the set point, the catalyst is being fed into the reactor at a constant rate. If the reaction temperature is higher the catalyst dispenser is blocked; dispensing of the catalyst is not resumed until the set point temperature has been reached again. The amount of catalyst added is a function of the duration of the switching cycle. The effect has been discussed of the form of this function on the course of the switching cycle. The results have been tested experimentally on a laboratory reactor controlled in an unstable steady state.
Capillary gas chromatography of trimethyl- and methylethylbiphenyls
Authors: Novrocík Jan , Novrocíková Marta
Published: January 2014

Capillary gas-liquid chromatography with three columns impregnated with non-polar, medium and polar stationary phases has been used for determination of the Kováts indexes of methylethyl- and trimethylbiphenyls carrying the alkyl groups in the both rings. From elution data of isomeric methyl- and ethylbiphenyls the increments of methyl and ethyl groups have been determined, the theoretical Kováts indexes of the mentioned methylethyl- and trimethylbiphenyls have been calculated, and possibility of prediction and assessment of the Kováts indexes of these substances has been discussed. Parameters of the straight line given by the relation IApiez.L = k . Istat.phase(2) + q have been determined, and correlation coefficients of these relations have been estimated.
Polarographic reduction of 2-nitromethyl-4,4,6-trimethyl-3,5-dicyano-1,4-dihydropyridine and of its 4,4-spiroanalogues
Authors: Kuthan Josef , Kurfürst Antonín , Raclová Františka , Volke Jiří
Published: January 2014

The reduction of 2-nitromethyl substituted 1,4-dihydropyridines at a dropping mercury electrode and their electron absorption spectra were studied. The probable mechanism of the electroreduction is discussed.
Synthesis of bridgehead fluorobicyclo[2.2.2]octanes
Authors: Kopecký Jan , Šmejkal Jaroslav
Published: January 2014

The paper describes preparation of bridgehead, i.e. 1 and/or 4-fluorobicyclo[2.2.2]octanes from the respective bicyclo[2.2.2]octanols with the Yarovenko reagent.
Synthesis and transformations of mercaptobicyclo[2.2.2]octanes
Authors: Kopecký Jan , Šmejkal Jaroslav
Published: January 2014

The paper describes preparation of 1-mercaptobicyclo[2.2.2]octanes by the isothiouronium method and transformations of 1-mercapto-4-methyl derivative into the corresponding methyl sulphide, methyl sulphoxide, methyl sulphone and disulphide.
Participation of 19-substituents in hypobromous acid addition to 3,4- and 4,5-unsaturated steroids
Authors: Kočovský Pavel , Černý Václav
Published: January 2014

Participation of a 19-substituent (hydroxyl, methoxyl, acetoxyl) in hypobromous acid addition to 3- and 4-cholestenes was investigated. All three 3,4-unsaturated compounds Ia-Ic yielded exclusively the cyclic ether VI as a product of 5(O)n participation. Contrasting with this behavior, the isomeric 4-cholestenes react differently depending on the substituent at C(19): Either exclusively (IIa → XI) or predominantly (IIb → XI) with 5(O)n participation or with 6(O)π,n participation (IIc → XIVc). These results are compared with those of 19-substituted 6- and 5-cholestenes III and IV.
Vapour-phase non-ideality in low-pressure vapour-liquid equilibrium data correlation
Authors: Linek Jan
Published: January 2014

The effect of vapour-phase imperfections and the volumetric behavior of liquid phase on the low-pressure VLE data reduction was investigated. The errors in the vapour-phase composition due to processing experimental data assuming ideal behavior of the vapour phase were evaluated.
Hydrolysis kinetics and mechanism of diarylthiocarbamates in 20% aqueous dioxane medium
Authors: Mindl Jaromír , Balcárek Pavel , Šilar Lubomír , Večeřa Miroslav
Published: January 2014

Substituted S-aryl and O-aryl N-arylthiocarbamates have been synthetized. Kinetic studies of hydrolysis of these compounds in 20% aqueous dioxane prove the E1cB mechanism. The found Hammett reaction constants, activation entropy values, Broensted coefficients, and comparison of reactivity with N-methyl analogues have been discussed as criteria of the mentioned mechanism. Hydrolysis results of thiocarbamates in the same medium are compared.
The effect of crown ether on steric hindrance to base approach in bimolecular elimination: evidence against clump aggregate model of ion-paired alkoxide base
Authors: Pánková Magdalena , Závada Jiří
Published: January 2014

The effect of 18-crown-6-ether upon geometrical orientation and rates was investigated in tert-C4H9OK-tert-C4H9OH promoted anti-elimination from two homologous series of tosylates, RCH2CHOTsC5H11 and RCHOTsCH2C5H11 (R = H, CH3, C2H5, n-C3H5, iso-C3H7, tert-C4H9). Steric requirements of the cis- and trans-stereoselective base species operating in the reaction in the absence and in the presence of the crown ether, respectively, have been assessed. An unambiguous distinction has been made between two pending models of the cis-stereoselective (ion-paired) base.
Effect of withdrawal flow velocity on the composition of a two phase system in a mixing tank
Authors: Sharma R. N. , Das H. C. L.
Published: January 2014

When a two phase mixture containing solids dispersed in a liquid medium is continuously fed and withdrawn from a mixing tank then, at steady state, the concentration of solids in the tank will equal the inlet and outlet concentrations only at the conditions of isokinetic withdrawal where the velocity in the withdrawal tube is the same as the approach velocity at the tip of the discharge opening. For a preferred withdrawal position the data is analysed to give an empirical correlation from which the steady state concentration of solids in the tank can be calculated if the withdrawal velocity is known for glass beads-water system stirred in a tank using turbine type mixing impeller.
Atomic absorption spectrometry of cobalt in the presence of chelating agents
Authors: Komárek Josef , Kolčava Dalibor , Sommer Lumír
Published: January 2014

The effect of chelating agents on the determination of cobalt in various flames, in a graphite cuvette and tantalum boat was studied considering the expected reaction mechanism of the atomization of cobalt and the reagent donor atom. A marked increase in the sensitivity of the determination of cobalt was observed in the presence of 1-(2-pyridylazo)-2-naphthol, pyrrolidinedithiocarboxylate, diethyldithiocarbamate, 8-mercaptoquinoline, 8-hydroxyquinoline and thenoyltrifluoroacetone for atomization from a tantalum boat. The optimum conditions for the determination of cobalt in the presence of 1-(2-pyridylazo)-1-naphthol are given.
Global steady state simulation of complex technological systems - an unified approach
Authors: Vrba Josef
Published: January 2014

In general, mathematical models of steady state simulation schemas of complex technological processes are formed by sets of algebraic equations. The formal description of global approach to the solution of such sets is presented. The utilization of preliminary solution of linear equations of the set for its reduction and for the expression of dependency of the so-called eliminated variables on the remaining ones, as arguments of the reduced set, (i.e. the first decomposition level) is considered. The determination of disjoint subsystems of the reduced set (i.e. the subsets of nonlinear equations which may be solved serially and independently of each other in a sequence) and the determination of the hierarchy of their solution, when there are several such subsystems, is meant as the second decomposition level. The possibility of including of special models with particular computational algorithms in the equation-like model of complex system and the way of solution of such a problem with the mentioned two-level decomposition is also discussed. The including of both types of decomposition and the solution of the reduced set of equations in common computational block is dealt with.
Metal-oxide induced redox chain addition of tetrachloromethane to a carbon-carbon double bond
Authors: Hájek Milan , Šilhavý Přemysl , Málek Jaroslav
Published: January 2014

Formation of 1 : 1 adducts in the addition of tetrachloromethane to a terminal carbon-carbon double bond was investigated at 76-200 °C. The redox chain addition reaction with 1-octene, electron-deficient alkenes and unconjugated aliphatic dienes induced by catalytic amounts of copper(I) or copper(II) oxides in conjugation with diethylamine or diisopropylamine afforded the corresponding 1 : 1 adducts up to in 85% yields. Aliphatic 1,3-dienes underwent redox chain 1,4-addition giving isomeric 1,1,1,5-tetrachloro-3-alkenes.
Liquid-phase catalytic hydrogenation of unsaturated ethers
Authors: Červený Libor , Šabata Stanislav , Růžička Vlastimil
Published: January 2014

Catalytic hydrogenations of 3-phenyloxy-1-propene, 3-phenyl-3-methoxy-1-propene, and 1-phenyl-3-methoxy-1-propene were studied at normal conditions, in substance, in methanol, and in cyclohexane on platinum and palladium carrier catalysts. The hydrogenations were usually accompanied by hydrogenolysis of the ether bond. The effects of the substance structure, solvent, and catalyst type on the course of the hydrogenation and hydrogenolysis were examined. Reaction schemes were suggested, described in some cases by power 1st order kinetic equations.
Hydrogenation of 2-phenyl-1-propene on platinum black modified with copper
Authors: Paseka Ivo , Červený Libor , Mach Josef , Růžička Vlastimil
Published: January 2014

Copper deposited from a solution of copper(II) formate on Pt-black at surface coverage lower than unity is present on the platinum surface both in the form of ad-atoms and in the form of multiatomic layers. From the dependence of the hydrogenation rate on coverage by copper is followed that the reaction rate depended on the number of free pairs of the adsorption sites of platinum unoccupied by copper.
Products formed in the radiation synthesis of 5-oxo-tetrahydrofuran-3-carboxylic acid derivatives
Authors: Kučera Jaromír , Moravec Jaromír
Published: January 2014

After the radiation-induced addition of 2-propanol to the diesters of cis-2-butenedioic (maleic) acid at 20 °C the reaction mixture contains not only the expected lactone-type products, i.e., the derivatives of 2,2-dimethyl-5-oxotetrahydrofuran-3-carboxylic acid (II) but also the corresponding hydroxy derivatives, i.e., the derivatives of 3-carboxy-4-methyl-4-hydroxypentanoic acid (IV). These hydroxy derivatives are formed as the primary products, however, they are not stable in the solution even in the form of their diesters. Their lactonization accompanied by the splitting off of alcohols proceeds rather slowly. The lactonization rate constant of the di-isopropyl ester of the acid IV is 1.61 . 10-5 s-1, of the di-n-octyl ester of IV it is 7.41 . 10-6 s-1 at 25 °C. At a higher temperature, e.g., during the esterification, the hydroxy derivatives of IV are partly lactonized, partly they form the respective unsaturated diesters by splitting off a molecule of water. A series of new esters of the acid II and of the triesters of its 4-(1,2-dicarboxyethyl) derivative (telomer 1 : 2) are described and the wavenumbers of the characteristic lactone bands in the region 1 777 - 1 786 cm-1 in the IR spectra of both types of lactone-esters are given.
The synthesis of methyl tetrosides and their methyl ethers
Authors: Jarý Jiří , Marek Miroslav
Published: January 2014

Methyl α- and β-D-threofuranosides (I and II) and methyl α- and β-D-erythrofuranosides (VII and VIII) were prepared in a modified manner. For the preparation of monomethyl ethers of compounds I and II 1,2-O-isopropylidene-β-D-threofuranose (IV) was prepared as the starting compound. For the synthesis of monomethyl ethers of compounds VII and VIII partial methylation of these diols was made use of.
Psychotropic derivatives of 5-phenyl-7-chloro-1,3-dihydro-1,4-benzodiazepin-2-one and contribution to the synthesis of its 5-(2-chlorophenyl) analogue
Authors: Vejdělek Zdeněk , Rajšner Miroslav , Dlabač Antonín , Ryska Miroslav , Holubek Jiří , Svátek Emil , Protiva Miroslav
Published: January 2014

Alkylation of 7-chloro-5-phenyl-1,3-dihydro-1,4-benzodiazepin-2-one (I) with 2,5-dimethoxyphenacyl bromide and 3-(4-phenylpiperazino)propyl chloride afforded the N-substituted derivatives of nordazepam III and IV; compound IV revealed properties of a potential hypnotic agent. Reaction of 4-chloronitrobenzene with (2-chlorophenyl)acetonitrile in methanolic solutions of alkali hydroxides gave mixtures from which the following compounds were isolated: 5-chloro-3-(2-chlorophenyl)-2,1-benzisoxazole (VII), the O-methyloxime X, 5-chloro-2,3-bis(2-chlorophenyl)indole (XI), 2-chloro-4'-nitrobenzophenone (XVII) and 2-chloro-9-cyanoacridine N-oxide (XX). A similar reaction of 4-chloronitrobenzene with (2-fluorophenyl)acetonitrile gave compound XX as the main product; in smaller amounts 4-nitroanisole, 2-fluoro-4'-nitrobenzophenone (XVIII) and 2-chloroacridine-9-carbonitrile (XXIV) were obtained. Compound VII was reduced to the aminobenzophenone derivative V which was transformed via the phthalimidoacetyl derivative VI to the chlorodemethyldiazepam II.
Use of strategies to improve retention in primary care randomised trials: a qualitative study with in-depth interviews
Authors: Brueton V C , Stevenson F , Vale C L , Stenning S P , Tierney J F , Harding S , Nazareth I , Meredith S , Rait G
Published: January 2014

Objective

To explore the strategies used to improve retention in primary care randomised trials.

Design

Qualitative in-depth interviews and thematic analysis.

Participants

29 UK primary care chief and principal investigators, trial managers and research nurses.

Methods

In-depth face-to-face interviews.

Results

Primary care researchers use incentive and communication strategies to improve retention in trials, but were unsure of their effect. Small monetary incentives were used to increase response to postal questionnaires. Non-monetary incentives were used although there was scepticism about the impact of these on retention. Nurses routinely used telephone communication to encourage participants to return for trial follow-up. Trial managers used first class post, shorter questionnaires and improved questionnaire designs with the aim of improving questionnaire response. Interviewees thought an open trial design could lead to biased results and were negative about using behavioural strategies to improve retention. There was consensus among the interviewees that effective communication and rapport with participants, participant altruism, respect for participant's time, flexibility of trial personnel and appointment schedules and trial information improve retention. Interviewees noted particular challenges with retention in mental health trials and those involving teenagers.

Conclusions

The findings of this qualitative study have allowed us to reflect on research practice around retention and highlight a gap between such practice and current evidence. Interviewees describe acting from experience without evidence from the literature, which supports the use of small monetary incentives to improve the questionnaire response. No such evidence exists for non-monetary incentives or first class post, use of which may need reconsideration. An exploration of barriers and facilitators to retention in other research contexts may be justified.
Conducting qualitative research in the British Armed Forces: theoretical, analytical and ethical implications
Authors: Finnegan Alan
Published: January 2014

The aim of qualitative research is to produce empirical evidence with data collected through means such as interviews and observation. Qualitative research encourages diversity in the way of thinking and the methods used. Good studies produce a richness of data to provide new knowledge or address extant problems. However, qualitative research resulting in peer review publications within the Defence Medical Services (DMS) is a rarity. This article aims to help redress this balance by offering direction regarding qualitative research in the DMS with a focus on choosing a theoretical framework, analysing the data and ethical approval. Qualitative researchers need an understanding of the paradigms and theories that underpin methodological frameworks, and this article includes an overview of common theories in phenomenology, ethnography and grounded theory, and their application within the military. It explains qualitative coding: the process used to analyse data and shape the analytical framework. A popular four phase approach with examples from an operational nursing research study is presented. Finally, it tackles the issue of ethical approval for qualitative studies and offers direction regarding the research proposal and participant consent. The few qualitative research studies undertaken in the DMS have offered innovative insights into defence healthcare providing information to inform and change educational programmes and clinical practice. This article provides an extra resource for clinicians to encourage studies that will improve the operational capability of the British Armed Forces. It is anticipated that these guidelines are transferable to research in other Armed Forces and the military Veterans population.
Distal aspiration with retrievable stent assisted thrombectomy for the treatment of acute ischemic stroke
Authors: Humphries William , Hoit Daniel , Doss Vinodh T , Elijovich Lucas , Frei Donald , Loy David , Dooley Gwen , Turk Aquilla S , Chaudry Imran , Turner Raymond , Mocco J , Morone Peter , Fiorella David , Siddiqui Adnan , Mokin Maxim , Arthur Adam S
Published: January 2014

Objective

Flexible large lumen aspiration catheters and stent retrievers have recently become available in the USA for the revascularization of large vessel occlusions presenting within the context of acute ischemic stroke (AIS). We describe a multicenter experience using a combined aspiration and stent retrieval technique for thrombectomy.

Design

A retrospective analysis to identify patients receiving combined manual aspiration and stent retrieval for treatment of AIS between August 2012 and April 2013 at six high volume stroke centers was conducted. Outcome variables, including recanalization rate, post-treatment National Institutes of Health Stroke Scale (NIHSS) score, symptomatic intracranial hemorrhage, discharge 90 day modified Rankin Scale (mRS) score, and mortality were evaluated.

Results

105 patients were found that met the inclusion criteria for this retrospective study. Successful recanalization (Thrombolysis in Cerebral Infarction score 2B) was achieved in 92 (88%) of these patients. 44% of patients had favorable (mRS score 0–2) outcomes at 90 days. There were five (4.8%) symptomatic intracerebral hemorrhages and three procedure related deaths (2.9%).

Conclusions

Mechanical thrombectomy utilizing combined manual aspiration with a stent retriever is an effective and safe strategy for endovascular recanalization of large vessel occlusions presenting within the context of AIS.
Outcome of surgical treatment for umbilical swellings in bovine youngstock
Authors: Williams H. J. , Gillespie A. V. , Oultram J. W. , Cripps P. J. , Holman A. N.
Published: January 2014

Umbilical swellings are commonly identified in calves and can be caused by hernia formation, infection of the remnants of umbilical vessels or a combination of both. Ninety‐one cases with umbilical swellings were admitted to the Leahurst Farm Animal Practice (LFAP) between July 2004 and February 2012; 55 were simple hernias and 36 had associated infection. Eighty‐seven cases underwent surgery of which 86 survived until discharge. Postoperative complications occurred in 65/86 animals (73 per cent). In 51 cases (81 per cent) this was classified as minor requiring no additional treatment. Placement of a prosthetic mesh was associated with a higher OR for developing severe postoperative complication when compared with those not receiving a mesh (OR=19.3; 95% CI 4.5 to 83.5). Long‐term survival results were available for 49 animals, 22 of which were remaining in the herd with a median age of 1346 days (3.7 years). Of the 27 animals which had exited the herd, 16 were adult dairy cows, 7 were dairy heifers, 2 were beef animals and 2 exited at an unknown stage. Umbilical surgery in calves carries a good prognosis, although placement of a mesh increases the risk of complications occurring in the postoperative period.
Estimating farm‐level private expenditure on veterinary medical inputs in England
Authors: Gilbert W. , Rushton J.
Published: January 2014

The current re‐evaluation of responsibility and cost sharing between the public and private sectors with reference to animal health and welfare (AHW) would be improved by a greater understanding of the contributions made at farm level. This knowledge would facilitate the design of a cost‐sharing system which best balances technical, economic and political objectives. This paper presents a framework by which the farm‐level investment in AHW can be assessed. An evaluation of data available for the framework was made and, as a benchmark, an estimate of total expenditure on veterinary medical inputs for commercial agricultural holdings in England calculated. In 2010/2011 it is calculated that farmers on commercial holdings in England spent £230 million on veterinary medicines and fees, with an additional £160 million being spent for horses kept on non‐commercial holdings. By contrast, for 2012/2013, Defra budgeted £277 million on AHW. The results presented emphasise the critical importance of generating sufficient evidence to support the development of an efficient, equitable and sustainable AHW strategy.
Traditional Chinese Medicine Injection for Angina Pectoris: An Overview of Systematic Reviews
Authors: Luo Jing , Shang Qinghua , Han Mei , Chen Keji , Xu Hao
Published: January 2014

Traditional Chinese medicine (TCM) injection is widely used to treat angina pectoris in China. This overview aims to systematically summarize the general characteristics of systematic reviews (SRs) on TCM injection in treating angina, and assess the methodological and reporting quality of these reviews. We searched PubMed, Embase, the Cochrane Library and four Chinese databases from inception until March 2013. Data were extracted according to a preset form. The AMSTAR and PRISMA checklists were used to explore the methodological quality and reporting characteristics of included reviews, respectively. All data analyses were descriptive. 46 SRs involving over 57,463 participants with angina reviewing 23 kinds of TCM injections were included. The main outcomes evaluated in the reviews were symptoms (43/46, 93.5%), surrogate outcomes (42/46, 91.3%) and adverse events (41/46, 87.0%). Few reviews evaluated endpoints (7/46, 15.2%) and quality of life (1/46, 2.2%). One third of the reviews (16/46, 34.8%) drew definitely positive conclusions while the others (30/46, 65.2%) suggested potential benefits mainly in symptoms, electrocardiogram and adverse events. With many serious flaws such as lack of a protocol and inappropriate data synthesis, the overall methodological and reporting quality of the reviews was limited. While many SRs of TCM injection on the treatment of angina suggested potential benefits or definitely positive effects, stakeholders should not accept the findings of these reviews uncritically due to the limited methodological and reporting quality. Future SRs should be appropriately conducted and reported according to international standards such as AMSTAR and PRISMA, rather than published in large numbers.
Clinical Efficacy of Aconitum-Containing Traditional Chinese Medicine for Diabetic Peripheral Neuropathic Pain
Authors: Feng Ling , Liu Wen-Ke , Deng Lan , Tian Jia-Xing , Tong Xiao-Lin
Published: January 2014

Diabetic peripheral neuropathy is a common chronic complication of diabetes. Routine clinical management uses analgesics to relieve pain in combination with drugs for nerve repair. The drugs are often not effective for the severe pain cases, and these western medications also have side effects. We report a more effective treatment of diabetic peripheral neuropathic pain using a high dose of a traditional Chinese medicine, aconitum (including both Radix aconite preparata and Radix aconite kusnezoffii), in combination with Huangqi Guizhi Wuwu Tang (i.e., astragalus, cassia twig, white peony root, and spatholobi). In order to achieve stronger analgesic effects, we increased the clinical dosage of aconitum from 15 to 120 g. The aconitum was boiled for 6–8 hours, and licorice was also used to reduce potential toxicities of aconitum. In the four reported cases, the patients' neuropathic pain was remarkably reduced and the EMG profile was also improved with this treatment regimen. Adverse reactions were not observed during the therapy. Thus, aconitum represents a promising and safe treatment for the well-being of patients and their diabetic peripheral neuropathic pain. Future controlled clinical trials using traditional Chinese medicines containing aconitum in treating the neuropathic pain are warranted.
NUCLEAR LEVEL DENSITY OF HEAVY NUCLEI Z≥90 THROUGH SEMICLASSICAL METHOD
Authors: PAHLAVANI M. R. , ALAVI S. A. , FARHADI E.
Published: January 2014

The nuclear level density parameters of back shift Fermi gas model, including single-particle level density parameter a and excitation energy shift E1, for some heavy nuclei have been calculated in the framework of semiclassical approach. The single-particle level density have been obtained for mean-field Woods–Saxon potential. By using the obtained values of single-particle level density parameter and excitation energy shift, the spin cut-off factor has been calculated at the neutron binding energy.
Challenges in Marine Affairs Management under the New Chinese Leadership
Authors: TSENG Katherine Hui-Yi
Published: January 2014

The Xi administration has established a new task force for high-level coordination and policy promulgation of maritime affairs. The move further echoes Beijing's determination to pursue new policies to establish China into a new marine power. Beijing is restructuring its marine affairs administration and law enforcement as its first step. Yet, challenges remain on tackling the different departmental interests and the culture of intra-agency competition for central budget and policy support.
Chinese Contractors in the United States
Authors: CO Catherine Yap
Published: January 2014

A 2009 American Society of Civil Engineers report indicates significant underinvestment in the maintenance and upgrading of US infrastructure. The group estimates a five-year investment of US$2.2 trillion is required. This presents an exciting opportunity for Chinese construction and engineering firms. Because infrastructure work provides long-term economic benefits, if done without controversy, they might generate goodwill towards China and may even help advance Chinese commercial interests in the United States.
China's Expanding Outward Foreign Direct Investment in Southeast Asia and its Impacts
Authors: ZHAO Hong
Published: January 2014

The surge in China's outward foreign direct investment (OFDI) has attracted considerable attention, largely projected as “neo-colonialism” in Africa and having potential effects on the host countries. In Southeast Asia, however, Chinese investment provides capital, employment, income and regional labour-division. This article analyses the nature and distribution of these investments, the main drivers of China's OFDI to Southeast Asia and the impact on economic integration in this region.
Modelling and simulation of a Jurassic carbonate ramp outcrop, Amellago, High Atlas Mountains, Morocco
Authors: Shekhar R. , Sahni I. , Benson G. , Agar S. , Amour F. , Tomás S. , Christ N. , Alway R. , Mutti M. , Immenhauser A. , Karcz Z. , Kabiri L.
Published: January 2014

Carbonate reservoirs pose significant challenges for reservoir modelling and flow prediction due to heterogeneities in rock properties, limits to seismic resolution and limited constraints on subsurface data. Hence, a systematic and streamlined approach is needed to construct geological models and to quickly evaluate key sensitivities in the flow models. This paper discusses results from a reservoir analogue study of a Middle Jurassic carbonate ramp in the High Atlas Mountains of Morocco that has stratigraphic and structural similarities to selected Middle East reservoirs. For this purpose, high-resolution geological models were constructed from the integration of sedimentological, diagenetic and structural studies in the area. The models are approximately 1200×1250 m in size, and only faults (no fractures) with offsets greater than 1 m are included. Novel methods have been applied to test the response of flow simulations to the presence or absence of specific geological features, including proxies for hardgrounds, stylolites, patch reefs, and mollusc banks, as a way to guide the level of detail that is suitable for modelling objectives. Our general conclusion from the study is that the continuity of any geological feature with extreme permeability (high or low) has the most significant impact on flow.
On detection and tracking of variant phenomena clouds
Authors: Thai My T. , Tiwari Ravi , Bose Raja , Helal Abdelsalam
Published: January 2014

Phenomena clouds are characterized by nondeterministic, dynamic variations of shapes, sizes, direction, and speed of motion along multiple axes. The phenomena detection and tracking should not be limited to some traditional applications such as oil spills and gas clouds but also be utilized to more accurately observe other types of phenomena such as walking motion of people. This wider range of applications requires more reliable, in-situ techniques that can accurately adapt to the dynamics of phenomena. Unfortunately, existing works which only focus on simple and well-defined shapes of phenomena are no longer sufficient.

In this article, we present a new class of applications together with several distributed algorithms to detect and track phenomena clouds, regardless of their shapes and movement direction. We first propose a distributed algorithm for in-situ detection and tracking of phenomena clouds in a sensor space. We next provide a mathematical model to optimize the energy consumption, on which we further propose a localized algorithm to minimize the resource utilization. Our proposed approaches not only ensure low processing and networking overhead at the centralized query processor but also minimize the number of sensors which are actively involved in the detection and tracking processes. We validate our approach using both real-life smart home applications and simulation experiments, which confirm the effectiveness of our proposed algorithms. We also show that our algorithms result in significant reduction in resource usage and power consumption as compared to contemporary stream-based approaches.
An integrated approach to safety and security based on systems theory
Authors: Young William , Leveson Nancy G.
Published: January 2014

Applying a more powerful new safety methodology to security risks.
Report on INEX 2013
Authors: Bellot P. , Doucet A. , Geva S. , Gurajada S. , Kamps J. , Kazai G. , Koolen M. , Mishra A. , Moriceau V. , Mothe J. , Preminger M. , SanJuan E. , Schenkel R. , Tannier X. , Theobald M. , Trappett M. , Trotman A. , Sanderson M. , Scholer F. , Wang Q.
Published: January 2014

INEX investigates focused retrieval from structured documents by providing large test collections of structured documents, uniform evaluation measures, and a forum for organizations to compare their results. This paper reports on the INEX 2013 evaluation campaign, which consisted of four activities addressing three themes:
searching professional and user generated data
(Social Book Search track);
searching structured or semantic data
(Linked Data track); and
focused retrieval
(Snippet Retrieval and Tweet Contextualization tracks). INEX 2013 was an exciting year for INEX in which we consolidated the collaboration with (other activities in) CLEF and for the second time ran our workshop as part of the CLEF labs in order to facilitate knowledge transfer between the evaluation forums. This paper gives an overview of all the INEX 2013 tracks, their aims and task, the built test-collections, and gives an initial analysis of the results.
Report on the SIGIR 2013 workshop on benchmarking adaptive retrieval and recommender systems
Authors: Castells Pablo , Hopfgartner Frank , Said Alan , Lalmas Mounia
Published: January 2014

In recent years, immense progress has been made in the development of recommendation, retrieval, and personalisation techniques. The evaluation of these systems is still based on traditional information retrieval and statistics metrics, e.g., precision, recall and/or RMSE, often not taking the use-case and situation of the actual system into consideration. However, the rapid evolution of recommender and adaptive IR systems in both their goals and their bapplication domains foster the need for new evaluation methodologies and environments. In the Workshop on Benchmarking Adaptive Retrieval and Recommender Systems, we aimed to provide a platform for discussions on novel evaluation and benchmarking approaches.