bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and thermal decomposition of magnesium dicarbide
Authors: Hájek Bohumil , Karen Pavel , Brožek Vlastimil
Published: March 2011

The conditions of formation of magnesium dicarbide from magnesium and acetylene were investigated; the optimum temperature, reaction period, and acetylene flow rate were sought so as to achieve high yields of dicarbide and minimize the free carbon deposit. The porosity of the magnesium dust was found to have a pronounced effect upon the yield; a considerable improvement was achieved by pressing the dust into pellets with controlled porosity. The powder X-ray diffraction patterns of MgC2 samples were studied. The intense reflection could be indexed for the bet symmetry (a = 392.9 ± 0.6 pm, c = 503.7 ± 1.2 pm), but as the intensity calculations for dicarbide models with different arrangements of the C22- groups indicate, the symmetry of the MgC2 lattice will be lower than tetragonal. The thermal decomposition of the dicarbide leading to sesquicarbide was examined in dependence on time and temperature by hydrolyzing the samples and analyzing the gaseous products by GLC. Due to the thermal decomposition, traces of sesquicarbide appear even during the dicarbide synthesis. The decomposition process was approximated by kinetic equations. The Arrhenius equation constants, in the temperature region of 485-560 °C, are AA = 4.97 . 1012 s-1, EA = 257 kJ mol-1.
Induction period of nucleation and metastable zone width
Authors: Nývlt Jaroslav
Published: March 2011

Induction periods of nucleation and metastable zone width were measured for the system KCl-H2O at 40 °C. The data for the induction period measured at constant undercooling produced at a finite rate were treated using relationships allowing for the time period of lower supersaturation. The relation NN = 1/tN has been found to apply to the system studied. The treatment of literature data for metastable zone width and induction period of nucleation in the systems KAl(SO4)2-H2O and (NH4)2Ni(SO4)2-H2O showed satisfactory agreement between values of nucleation exponent obtained by the two methods.
Drop size distribution in emulsions O/W stabilized by nonionic emulsifier; Description of distribution by empirical relations
Authors: Ludvík Miloslav , Durdil Petr
Published: March 2011

Here is analysed how suitable are the most frequently used empirical relations for description of drop size distribution. On a representative set of emulsifying experiments is demonstrated how suitable in the three-parametric logarithmic normal distribution according to Cohen and distribution according to Espenscheid-Kerker-Matijević. For these functions are proposed methods of parameter estimation suitable for their determination from the random sample of emulsion droplets. The fittnes of testing functions is discussed briefly.
Extraction of hafnium into benzene with tetraphenyl imidodiphosphate
Authors: Navrátil Oldřich , Cigánek Miroslav , Hermann Eckhard
Published: March 2011

The distribution of hafnium(IV) was studied between aqueous solutions of perchloric, hydrochloric, or nitric acids (HX) and benzene solutions of tetraphenyl imidodiphosphate (HA). From perchloric and hydrochloric acids at concentrations cHX ⪬ 3 mol l-1 hafnium extracted as HfXA3 complex. With the two acids present at higher concentrations or with nitric acid at concentrations cHNO3 ≥ 1.5 mol l-1 the initial ion exchange mechanism turns into a solvation mechanism associated with the formation of HfX4(HA)y complexes (X = ClO4, Cl). The extraction constant values are given and the extracting agent is compared with other acid organophosphorus reagents.
Autoprotolysis constants and activity ratios of the lyate ions in water-alcohol mixtures
Authors: Mollin Jiří , Pavelek Zdeněk , Schneiderová Alena , Vičar Jaroslav , Šimánek Vilím , Lasovský Jan
Published: March 2011

The autoprotolysis constants were determined potentiometrically for water-ethanol, water-1-propanol, water-2-propanol, and water-2-methyl-2-propanol mixtures containing alcohol in concentrations of 60% (m/m) and more. Three methods were employed for the calculation of the activity ratios of the lyate ions in the systems: an empirical method based on the autoprotolysis constant and the activities of the solvent constituents, a method based on thermodynamic data, particularly the Gibbs energies of ion transfer from water to the mixed solvent, and a method based on 1H NMR data. The results of the three methods are mutually compared and discussed. The known heats of ionization for the water-ethanol system and the ionization constants of the components enabled the entropy of ionization of a mixture of water with ethanol to be calculated.
Sodium tetralactamatoaluminates(1-). A study of valence vibrations of lactam grouping in sodium 6-hexanelactamato-isobutylaluminates(1-)
Authors: Kříž Otomar , Fusek Jiří , Čásenský Bohuslav
Published: March 2011

Sodium tetralactamatoaluminate(1-) complexes have been prepared by reaction of sodium tetraamidoaluminate with 4-butanelactame, 6-hexanelactame, and 12-dodecanelactame, and their infrared spectra have been measured in the region from 600 to 4 000 cm-1. For assignment of some bands, a series of sodium 6-hexanelactamato-isobutylaluminates(1-) and 2-methoxyethoxo-lactamatoaluminates(1-) have been prepared. The bands in the region 1550-1650 cm-1 are discussed.
Simultaneous mass and heat transfer to a plate electrode in the region of free convection with antiparallel fluxes of mass and heat
Authors: Novák Petr , Roušar Ivo
Published: March 2011

Simultaneous transfer of heat and ions to a vertical plate electrode in the region of free convection was treated mathematically by solving the Navier-Stokes, convective diffusion, and convective heat transfer equations. The direction of flow due to heat flux was considered opposite to that due to flux of ions. A criterion equation was proposed for the calculation of the Sherwood criterion with an error smaller than 2%. This was verified experimentally by measuring the limiting current densities for electrolytes containing K4Fe(CN)6 and K3Fe(CN)6 with KOH as base electrolyte.
Reactions graphs
Authors: Kvasnička Vladimír , Kratochvíl Milan , Koča Jaroslav
Published: March 2011

The reaction graphs for systematic and unambiguous representation of classes of reactions are suggested. This concept offers very simple and transparent method to analyze the complicated reaction schemes form the standpoint of their mechanistic realization. It is demonstrated that the reaction graphs can be used also for the canonisation of chemical reactions.
Solvatochromic study of internal charge transfer in 7,7-disubstituted quinone methides
Authors: Pavlíčková Libuše , Koutek Bohumír , Jehlička Václav , Souček Milan
Published: March 2011

Electronic spectra of 7,7-disubstituted quinone methides I-III with substituents of various electronegativities were measured in thirteen solvents. Character of the long-wavelength transition was investigated by correlation between transition energy and ionization potential of the donor part of the molecule as well as by comparison of transition moment with Δμ. The long wavelength absorption band of Ia-Id, IIa and IV does not correspond to a pure (π-π*) transition, but it is perturbed by intramolecular charge transfer.
Preparation and absolute configuration at C(22) of 21,26,27-trinor-5α-cholestane-22,25-diol derivatives
Authors: Pouzar Vladimír , Vašíčková Soňa , Drašar Pavel , Černý Ivan , Havel Miroslav
Published: March 2011

Reaction of 5α-pregnan-21-al (V), obtained from ester of the corresponding acid III via the alcohol IV, with lithium salt of 1-methoxymethoxy-2-propyne afforded both the isomeric 25-methoxymethoxy-21,26,27-trinor-5α-cholest-23-yn-22-ols (VI and VIII) which were converted into two 21,26,27-trinor-5α-cholestane-22,25-diols (XI, XV). Absolute configuration of the alcohols X and XIV was assigned by chemical correlation with derivatives XXVI and XXVII of known absolute configuration at C(20). The correlation was based on reduction of thiocarbonates derived from the diols XXII and XXIV for which also Cotton effects of their complexes with nickel acetylacetonate were studied. Both diols were prepared from 5α-pregnan-20-one (XVIII) via 5α-pregn-20-yne (XIX) and the 21,26,27-trinor-5α-cholest-20-ene derivative XXI.
Interaction of vinyl alcohol molecules
Authors: Leška Jaroslav , Žáková Mária
Published: March 2011

The interaction has been studied between two vinyl alcohol molecules giving two acetaldehyde molecules, two models being considered: The first model locates the vinyl alcohol molecules in one plane and mutually rotated by 180°. The symmetry-forbidden HOMO-LUMO interaction between the molecules in this model become allowed through free rotation of the molecules around their CC bonds whereby hydrogen transfer is facilitated. The second model locates the vinyl alcohol molecules in two parallel planes, the allowed HOMO-LUMO interaction causing stabilization of the associate. Energy minimization of the supersystem in the both models by the technique of full optimization (at the level of CNDO/2 method) leads to a barrier-free transformation of vinyl alcohol into acetaldehyde.
Amino acid sequence of the acidic acrosin inhibitor (BUSI I B2) from bull seminal plasma
Authors: Meloun Bedřich , Jonáková Věra , Čechová Dana
Published: March 2011

The molecule of the inhibitor consists of 63 amino acid residues whose sequence is the following: Glu-Ile-Tyr-Phe-Glu-Pro-Asp-Phe-Gly-Phe-Pro-Pro-Asp-Cys-Lys-Val-Tyr-Thr-Glu-Ala-Cys-Thr-Arg-Glu-Tyr-Asn-Pro-Ile-Cys-Asp-Ser-Ala-Ala-Lys-Thr-Tyr-Ser-Asn-Glu-Cys-Thr-Phe-Cys-Asn-Glu-Lys-Met-Asn-Asn-Asp-Ala-Asp-Ile-His-Phe-Gln-His-Phe-Gly-Glu-Cys-Glu-Tyr. The sequential data were obtained by the analysis of peptides isolated from the tryptic and chymotryptic digest of the carboxymethylated inhibitor. The molecular weight of the inhibitor calculated from its amino acid sequence is 7377.
Oxidation of ethylenediphosphinetetraacetate anions
Authors: Podlahová Jana , Podlaha Jaroslav
Published: March 2011

The oxidation of the ethylenediphosphinetetraacetate anion and its protonated forms by iodine, periodate, hydrogen peroxide, and oxygen has been studied in aqueous solution. The oxidation by the first three reagents is fast and yields a single product, bis(phosphine oxide), which has been isolated and characterized as ethylenebis(phosphinyl)tetraacetic acid. The oxidation by molecular oxygen proceeds considerably more slowly; in weakly acid solutions its rate is determined by the properties of the oxygen rather than by the electronic structure of the various protonated substrate species. The inhibiting effect of the phosphonium structures takes place only in strongly acid solutions.
Reexamination of the structure of veramarine
Authors: Kaneko Ko , Tanaka Mikako , Kuribayashi Taeko , Mitsuhashi Hiroshi , Tomko Jozef
Published: March 2011

The previously proposed α-orientation for the C(16)-hydroxyl group of the alkaloid veramarine (Ia) has been revised; the 1H and 13C NMR data of Ia and the base-catalyzed solvolysis of its O-diacetate Id evidenced veramarine to be (25S)-cev-5-enine-3β,16β,20β-triol (Ib).
Vasopressin analogues with effect on central nervous system: Synthesis and biological properties
Authors: Brtník František , Krejčí Ivan , Kupková Běla , Hrbas Pavel , Škopková Jana , Barth Tomislav , Jošt Karel
Published: March 2011

Synthesis of four vasopressin analogues which do not contain the glycinamine residue in position 9 and have a basic non-coded amino acid in position 8 is described. All the analogues exhibit very low endocrine activities and are effective in the passive avoidance test.
Determination of platinum in biological material by differential pulse polarography: Analysis in urine, plasma and tissue following sample combustion
Authors: Vrabec Viktor , Vrána Oldřich , Kleinwächter Vladimír
Published: March 2011

A method is described for determining total platinum content in urine, blood plasma and tissues of patients or experimental animals receiving cis-dichlorodiamineplatinum(II). The method is based on drying and combustion of the biological material in a muffle furnace. The product of the combustion is dissolved successively in aqua regia, hydrochloric acid and ethylenediamine. The resulting platinum-ethylenediamine complex yields a catalytic current at a dropping mercury electrode allowing to determine platinum by differential pulse polarography. Platinum levels of c. 50-1 000 ng per ml of the biological fluid or per 0.5 g of a tissue can readily be analyzed with a linear calibration.
The characteristic ratio of butadiene-styrene and butadiene-acrylonitrile copolymers
Authors: Bohdanecký Miloslav , Petrus Vladimír
Published: March 2011

A method advanced recently is used to estimate the characteristic ratio C∞ for statistical butadiene-styrene and butadiene-acrylonitrile copolymers from the reported data of the limiting viscosity number and sedimentation coefficient. The results are compared with those of the traditional methods. The dependences of C∞ on the copolymer composition are discussed and interpreted in terms of steric and/or dipole-dipole interactions of adjacent monomeric units.
Intermolecular hydrogen transfer in unsaturated hydrocarbons induced by dimeric titanocene
Authors: Mach Karel , Petrusová Lidmila , Antropiusová Helena , Hanuš Vladimír , Tureček František , Sedmera Petr
Published: March 2011

μ-(η5 : η5-Fulvalene)-di-μ-hydrido-bis(η5-cyclopentadienyltitanium) and μ-(η5 : η5-fulvalene)-μ-chloro-μ-hydrido-bis(cyclopentadienyltitanium) form a thermally stable complex which catalyzes the intermolecular hydrogen transfer in unsaturated hydrocarbons, in addition to isomerizations and cyclizations. Cyclic hydrocarbons disproportionate under catalysis to saturated and aromatic hydrocarbons, while linear olefins yield predominantly linear alkanes and high molecular weight tar. The catalyst enables the hydrocarbon system to approach the thermodynamic equilibrium through a series of substitution reactions between alkyl- and allyltitanocene-like species and olefins and dienes. The catalytic complex was characterized by UV and ESR spectra. About one half of overall titanium content could be converted to mononuclear η3-allyltitanocene-like species, stable up to 400 °C. This exceptional thermal stability is ascribed to a firmly bound allyl containing ligand.
syn-anti Dichotomy in zinc-promoted dehalogenation of open-chain vicinal dihalides: The effect of the leaving groups
Authors: Pánková Magdalena , Kocián Oldřich , Krupička Josef , Závada Jiří
Published: March 2011

The title effect has been investigated in the homologous series of erythro- and threo-5,6-dihalodecanes (X = Br, Y = I; X = Cl, Y = I; X = F, Y = I; X = Br, Y = Br; X = Cl, Y = Br; X = F, Y = Br; X = Cl, Y = Cl; X = F, Y = Cl). It has been found that proportion of syn-elimination in the overall reaction varies with the variation of the halogen leaving groups in the order I < Br < Cl < F, ranging between the extreme 3-30% in the erythro- and 5-60% in the threo-series. On basis of the variable transition state theory, observed pattern of syn-anti dichotomy has been correlated with the extent of double bond development in the transition state.
The structural requirements of oxytocin and vassopressin analogues for the activation of adenylate cyclase in the rat kidney medullary membrane system
Authors: Butlen Daniel , Barth Tomislav , Cantau Bernard , Guillon Gilles , Jard Serge , Lebl Michal , Brtník František , Jošt Karel
Published: March 2011

The binding properties and the activation of adenylate cyclase by the structural analogues of neurohypophysial hormones in the rat kidney membrane system were investigated. Certain structural modifications of the vasopressin molecule, i.e. absence of the primary amino group, removal of the carboxy-terminal part and combinations of the modifications lowered the affinity and activating properties of the compounds. A similar effect was observed in the oxytocin series where the absence of the primary amino group decreased the binding and activation of the adenylate cyclase. Two modifications improved the binding affinity: the carba substitution in both the series of deamino-analogues and the introduction of a lipophilic substituent in the para-position of the aromatic amino acid in position 2 of the peptide chain. An attempt was made to correlate the binding and activating properties with the biological effects.
On the activity coefficients of components in molten salts
Authors: Malinovský Milan , Koštenská Irena , Vrbenská Jaroslava
Published: March 2011

The classical activity coefficient is shown to be unsuitable for a characterization of the interaction of components in molten salts. A better approach consists in the use of the „global" activity coefficient by which the model activity must be multiplied to give the thermodynamic activity, or of the suggested „internal"activity coefficient by which the concentration variable is multiplied in the expression for the model activity to become identical with the thermodynamic activity. The conclusions are illustrated on a LiF-NaCl melt. The interrelation between the global and the internal activity coefficients is analyzed. It is suggested that the internal activity coefficient may find application is statistical modelling of melt systems.
Effect of Fe(III) on specific adsorption of aliphatic carbamide derivatives at the dropping mercury electrode
Authors: Masłowska Joanna , Czerwinska Halina
Published: March 2011

The specific adsorption of carbamide and its aliphatic derivatives (L) was studied by the droptime method in the system Fe(ClO4)3-L-HClO4-H2O, and the adsorption process was elucidated. From the calculated surface concentrations and adsorption isotherms, it was found that the adsorption of aliphatic carbamide derivatives is higher in the presence of Fe(III) ions than in their absence under the same conditions. In the presence of Fe(III) ions at the interface, free molecules of carbamide derivatives and the complexes [Fe(H2O)6-nLn]3+ as well as the complexes [Fe(H2O)5-nLnLads]3+ and [Fe(H2O)5-nLnLads]2+ formed with the adsorbed ligand are adsorbed. The adsorption was found to proceed according to the Frumkin's isotherm.
NMR spectra (13C and 29Si) as a probe into the electronic structure of cyclopropylsilanes
Authors: Schraml Jan , Grignon-dubois Micheline , Dunoguès Jacques , Jancke Harald , Engelhardt Günter , Chvalovský Václav
Published: March 2011

29Si and 13C NMR chemical shifts are reported for cyclopropyl derivatives with the structure (CH3)3-nRnSiC3H5 where R = OSi(CH3)3 and OCH3. He carbon chemical shifts show substituent effects which are intermediate between those found in the corresponding vinyl and ethyl silanes. The 29Si chemical shifts, however, do not provide any evidence for back bonding between the cyclopropane ring and the silicon atom.
[3,3]-Sigmatropic reactions in the enamine series
Authors: Červinka Otakar , Fábryová Anna , Josef Jan , Sermek Vladimír , Smrčková Svatava
Published: March 2011

Thermal isomerization of 1-methyl-2-(3-butenylidene)pyrrolidine (Ib) afforded a mixture of Ib and 1,2-dimethyl-3-allyl-2-pyrroline (IIIa). Analogous reaction with 1-methyl-2-(3-butenyl)-2-piperidine (IIa) gave quantitatively 1,2-dimethyl-3-allyl-2-piperideine (IVa) by [3,3]-sigmatropic rearrangement.
Synthesis and stability of 2-oxoisothiocyanates
Authors: Bobošík Vladimír , Piklerová Anna , Martvoň Augustin
Published: March 2011

Enolizable 2-oxoisothiocyanates Ia-If were prepared from hydrochlorides of amino ketones, containing a hydrogen atom in the α-position, by reaction with thiophosgene in the presence of CaCO3. At room temperature the enol form of these compounds undergoes slow cyclization to give the isomeric 4-oxazoline-2-thiones IIb-IIf. In the presence of bases this isomerization proceeds rapidly even at room temperature. 2-Isothiocyanatocyclopentanone (Ia) does not cyclize to the corresponding oxazolinethione either on heating or action of bases. The rate of the thermally initiated isomerization of the 2-oxoisothiocyanates Ib-If was determined by IR spectroscopy.
Synthesis of 2-amino-5,7-dimethyl-4-oxopyrido[3,4-e]-1,3-thiazines
Authors: Koščík Dušan , Kristian Pavol , Forgáč Ondrej
Published: March 2011

New synthesis of pyrido[3,4-e]-1,3-thiazines consisting in reaction of 2,6-dimethyl-4-chloronicotinoyl isothiocyanate with primary or secondary amines, or with benzaldehyde phenylhydrazone, is described. High reactivity of the chlorine atom does not allow isolation of the corresponding thioureas, arising as intermediates, except in the case of the benzylamino derivative. Structure of the products was unequivocally confirmed by their spectral data (IR, UV, 1H NMR, 13C NMR and mass spectra). The synthesized derivatives do not undergo the Dimroth rearrangement.
Potential hypnotics and anxiolytics: 8-Chloro-6-(2-chlorophenyl)-1-[4-(2-methoxyethyl)piperazino]-methyl-4H-s-triazolo[4,3-a]-1,4-benzodiazepine and related compounds
Authors: Polívka Zdeněk , Holubek Jiří , Metyš Jan , Šedivý Zdeněk , Protiva Miroslav
Published: March 2011

Ethyl esters of 4-substituted piperazinoacetic acids IIIa-f were prepared by alkylation of 1-(ethoxycarbonylmethyl)piperazine with 2-methoxyethyl bromide, 2-ethoxyethyl bromide, 2-methylthioethyl chloride, 2-phenoxyethyl bromide and 2-phenylthioethyl bromide or by reactions of 1-(3-methoxypropyl)piperazine and 1-(2-methylthioethyl)piperazine with ethyl chloroacetate. Reactions of the esters with hydrazine hydrate gave the hydrazides IVa-f. Their treatment with 7-chloro-5-(2-chlorophenyl)-1,3-dihydro-1,4-benzodiazepin-2-thione resulted in the title compound Ia and analogues Ib-f. 1-(4-Methylpiperazinomethyl) derivatives Ig and IIg were similarly prepared from 4-methylpiperazinoacetic acid hydrazide (IVg). Compound Ig showed significant central depressant and anticonvulsant (electroshock) activity in mice. The enlargement of the substituent in position 4 of the piperazine residue results in an important decrease of these activities.
The bromination of the epimeric 4,5-cyclopropanocholestan-3-ones
Authors: Fajkoš Jan , Joska Jiří , Zajíček Jaroslav
Published: March 2011

Bromination of the epimeric 4,5-cyclopropanocholestan-3-ones I and XIII has been studied and structures of the products were established by chemical and spectral means. Conformation of the A ring in the bromo ketones and bromohydrins is discussed on the basis of spectral evidence.
Reactivity of the solid sodium carbonate towards the gaseous hydrogen chloride and the sulphur dioxide
Authors: Mocek Karel , Lippert Erich , Erdös Emerich
Published: March 2011

The rate of reaction of the anhydrous sodium carbonate with the hydrogen chloride and its mixture with sulphur dioxide was measured in an integral fixed-bed reactor. Reactivity of the active sodium carbonate towards the hydrogen chloride is lower as compared with its reactivity towards the sulphur dioxide. A relationship was found between the reactivity of the solid and the way of its preparation. The inactive form of the sodium carbonate is inactive towards both the sulphur dioxide and the hydrogen chloride. The active form of the sodium carbonate exhibits towards the hydrogen chloride a reactivity which is by orders of magnitude higher than that of the inactive form. The variation of the ratio of partial pressures of the hydrogen chloride and the sulphur dioxide in the reaction with the sodium carbonate does not affect significantly the total degree of the solid conversion, which attained a value of 65% in laboratory experiments. The degree of gas purification from the acid components did not fall under a value of 99% up to a solid conversion of about 50% at a mean gas contact time of about 10-2 s.
Semiempirical calculations of alkylation and protonation energies of bases of nucleic acids
Authors: Miertuš Stanislav , Trebatická Magdaléna
Published: March 2011

The semiempirical quantum-chemical MINDO/3 method has been used to study protonation and alkylation of bases of nucleic acids: cytosine, thymine, uracil, adenine, and guanine. The optimum sites of attack of the reagents H(+), CH3(+), and C2H5(+) have been found among selected nucleophilic positions of the mentioned bases. At the same time interaction energies of protonation and alkylation have been expressed, and relative affinity of the considered positions to the protonation and alkylation has been evaluated.
Randomised, Controlled Study of Preoperative Eletroacupuncture for Postoperative Pain Control after Cardiac Surgery
Authors: Coura Luiz Eduardo Faria , Manoel Cláudia Hideco Uratsuka , Poffo Robinson , Bedin Antonio , Westphal Glauco Adrieno
Published: March 2011

Background

This study aims to evaluate the effects of preoperative electroacupuncture (EA) on the need for opioids in the postoperative stage of conventional cardiac surgery.

Methods

A prospective, randomised and controlled study was conducted at Unimed Hospital Centre in Joinville, SC, Brazil. The day before the surgery, 32 patients undergoing cardiac surgery were randomised into two groups: patients from the treatment group received preoperative EA at bilateral points (LI4–LI11, LR3–ST36, PC6–TE5) for 30 min with alternating frequencies of 3 and 15 Hz. Patients from the control group received sham transcutaneous electrical nerve stimulation (TENS). Use of fentanyl during the postoperative period was measured.

Results

10 patients were excluded because of hemodynamic and ventilatory instability leaving 13 (10 male) in the treatment group and 9 (4 male) in the control group. The average total doses of fentanyl given were 13.1±2.2 and 16.3±1.6 μg/kg in the treatment and control groups respectively (p<0.002). The doses of patient controlled analgesia were 4.1±2.0 and 6.9±1.7 μg/kg in the treatment and control groups respectively (p<0.003). The number of boluses issued also differed (treatment 13.9±7.0 vs control 24.8±7.0, p<0.002). Pain intensity scores differed between the groups (treatment 2.5±1.1 vs control 4.0±2.0, p<0.04). One patient from the control group experienced drowsiness that justified a change in fentanyl infusion, as decided by the anaesthetist.

Conclusion

Preoperative electro-acupuncture in conventional cardiac surgery may reduce the postoperative consumption of fentanyl.
Disease, diagnosis or syndrome?
Authors: Pearce J M S
Published: March 2011

The advance of medical semantics is, in general, towards causation. As knowledge increases, the common consequence is the re-definition of disease. This starts with symptoms then a disorder of structure or function, abnormalities of images, genetics or biochemistry, the ultimate aim being a specific aetiological mechanism which replaces broader descriptions. But medical terminology of diseases, diagnoses and syndromes is inherently imprecise. Careless nomenclature causes confused dialogue and communication. Symptoms of uncertain cause are commonly lumped together and given a new ‘diagnostic’ label which also may confuse and produce false concepts that stultify further thought and research. Such medicalisation of non-specific aggregations of symptoms should be avoided. The defining characteristics of diseases and diagnoses should be validated and agreed. The pragmatic diagnoses of ‘symptom of unknown cause’ or ‘non-disease’ are preferable to falsely labelling patients with obscure or non-existent diseases.

“I tried to unveil the stillness of existence through a counteracting murmur of words, and, above all, I confused things with their names: that is belief.”

Jean-Paul Sartre (The Words, 1964).
CONSTANT SURFACE GRAVITY AND DENSITY PROFILE OF DARK MATTER
Authors: DE VEGA H. J. , SANCHEZ N. G.
Published: March 2011

Cumulative observational evidence confirms that the surface gravity of dark matter (DM) halos μ0 D = r0ρ0, where r0 and ρ0 are the halo core radius and central density, respectively, is nearly constant and independent of galaxy luminosity for a high number of galactic systems (spirals, dwarf irregular and spheroidals, elliptics) spanning over 14 magnitudes in luminosity and of different Hubble types. Remarkably, its numerical value, μ0D ≃140M⊙/ pc 2 = (18.6 MeV )3, is approximately the same (up to a factor of 2) in all these systems. First, we present the physical consequences of the independence of μ0D from r0: the energy scales as the volume [Formula: see text], while the mass and the entropy scale as the surface [Formula: see text] and the surface times log r0, respectively. Namely, the entropy scales similarly to the black hole entropy but with a much smaller coefficient. Second, we compute the surface gravity and the density profile for small scales from first principles and the evolution of primordial density fluctuations from the end of inflation till today using the linearized Boltzmann–Vlasov equation. The density profile ρ lin (r) obtained in this way decreases as r-1-ns/2 for intermediate scales, where ns≃0.964 is the primordial spectral index. This scaling is in remarkable agreement with the empirical behavior found observationally and in N-body simulations: r-1.6±0.4. The observed value of μ0D indicates that the DM particle mass m is on the keV scale. The theoretically derived density profiles ρ lin (r) turn to be cored for m on the keV scale and they are cusped for m on the GeV scale or beyond. We consider both fermions and bosons as DM particles decoupling either ultrarelativistically or nonrelativistically. Our results do not use any particle physics model and vary slightly with the statistics of the DM particle.
ETA-NUCLEON COUPLING CONSTANT IN QCD WITHSU(3)SYMMETRY BREAKING
Authors: SINGH JANARDAN P. , LEE FRANK X. , WANG LAI
Published: March 2011

We study the ηNN coupling constant using the method of QCD sum rules starting from the vacuum-to-eta correlation function of the interpolating fields of two nucleons. The matrix element of this correlation has been taken with respect to nucleon spinors to avoid unwanted pole contribution. The SU(3) -flavor symmetry breaking effects have been accounted for via the η-mass, s-quark mass and eta decay constant to leading order. Out of the four sum rules obtained by taking the ratios of the two sum rules in conjunction with the two sum rules in nucleon mass, three are found to give mutually consistent results. We find the SU(3) breaking effects significant, as large as 50% of the SU(3) symmetric part.
CHARACTERIZATION OF CHEMICALLY DEPOSITED CADMIUM SULFIDE THIN FILMS
Authors: CHOWDHURY R. I. , HOSSEN M. A. , MUSTAFA G. , HUSSAIN S. , RAHMAN S. N. , FARHAD S. F. U. , MURATA K. , TAMBO T. , ISLAM A. B. M. O.
Published: March 2011

Cadmium sulfide (CdS) thin films have been deposited on glass/conducting glass substrates using low-cost chemical bath deposition method. The deposited films have been characterized using various techniques in order to optimize growth parameters. It has been confirmed by X-ray diffraction measurement that the deposited layers are mainly consisting of CdS phase. The PEC measurements indicate that the deposited CdS layer is n-type in electrical conduction, and optical absorbance measurements show that the band gap is 2.42 eV for as-deposited film and 2.27 eV upon heat treatment for one hour in air ambient. Both atomic force microscopy and scanning electron microscopy measurements indicate the formation of pinhole free and smooth surface of CdS films of nanosized grains. The electrical resistivity is also observed in the order of 1044 Ω cm and decreases as temperature increases.
A framework of the use of certifications by hiring personnel in it hiring decisions
Authors: Hunsinger D. Scott , Smith Michael Alan , Winter Susan J.
Published: March 2011

IT certification represents a common and growing practice with significant implications for managing in-house IT workers and outsourcing contracts. Prior research is of limited value in understanding its use in common personnel decisions, such as hiring, and its role in the IS profession because of possible sponsor bias, conflicting findings, and inattention to the hiring process or the value of certification from the perspective of hiring personnel. Using an inductive approach, we developed a framework for understanding the use of IT certification in hiring. Contextual and proximate factors are identified, as are the various ways that IT certification is used. Our study provides a bridge between the beliefs of hiring personnel and existing theories to better understand a phenomenon of growing importance. Research questions for further empirical investigation are explored, showing that our conceptual framework provides a base for future research.
Immunotherapy of Brain Cancers: The Past, the Present, and Future Directions
Authors: Ge Lisheng , Hoa Neil , Bota Daniela A. , Natividad Josephine , Howat Andrew , Jadus Martin R.
Published: March 2011

Treatment of brain cancers, especially high grade gliomas (WHO stage III and IV) is slowly making progress, but not as fast as medical researchers and the patients would like. Immunotherapy offers the opportunity to allow the patient′s own immune system a chance to help eliminate the cancer. Immunotherapy′s strength is that it efficiently treats relatively small tumors in experimental animal models. For some patients, immunotherapy has worked for them while not showing long‐term toxicity. In this paper, we will trace the history of immunotherapy for brain cancers. We will also highlight some of the possible directions that this field may be taking in the immediate future for improving this therapeutic option.
Low-Complexity Online Synthesis for AMIDAR Processors
Authors: Döbrich Stefan , Hochberger Christian
Published: March 2011

Future chip technologies will change the way we deal with hardware design. First of all, logic resources will be available in vast amount. Furthermore, engineering specialized designs for particular applications will no longer be the general approach as the nonrecurring expenses will grow tremendously. Reconfigurable logic has often been promoted as a solution to these problems. Today, it can be found in two varieties: field programmable gate arrays or coarse-grained reconfigurable arrays. Using this type of technology typically requires a lot of expert knowledge, which is not sufficiently available. Thus, we believe that online synthesis that takes place during the execution of an application is one way to broaden the applicability of reconfigurable architectures. In this paper, we show that even a relative simplistic synthesis approach with low computational complexity can have a strong impact on the performance of compute intensive applications.
The Potential for a GPU-Like Overlay Architecture for FPGAs
Authors: Kingyens Jeffrey , Steffan J. Gregory
Published: March 2011

We propose a soft processor programming model and architecture inspired by graphics processing units (GPUs) that are well-matched to the strengths of FPGAs, namely, highly parallel and pipelinable computation. In particular, our soft processor architecture exploits multithreading, vector operations, and predication to supply a floating-point pipeline of 64 stages via hardware support for up to 256 concurrent thread contexts. The key new contributions of our architecture are mechanisms for managing threads and register files that maximize data-level and instruction-level parallelism while overcoming the challenges of port limitations of FPGA block memories as well as memory and pipeline latency. Through simulation of a system that (i) is programmable via NVIDIA's high-levelCglanguage, (ii) supports AMD's CTM r5xx GPU ISA, and (iii) is realizable on an XtremeData XD1000 FPGA-based accelerator system, we demonstrate the potential for such a system to achieve 100% utilization of a deeply pipelined floating-point datapath.
Serum Omega-3 and Omega-6 Fatty Acids and Cutaneous p53 Expression in an Australian Population
Authors: van der Pols Jolieke C. , Xu Chunxia , Boyle Glen M. , Hughes Maria C. , Carr Samuel J. , Parsons Peter G. , Green Adèle C.
Published: March 2011

Background: There is some evidence from experimental studies that long-chain n-3 and n-6 fatty acids may be able to modify early skin carcinogenesis, but whether this applies in the general population is not known.

Methods: We investigated associations between serum polyunsaturated fatty acid concentrations and p53 expression in normal skin, as a biomarker of early UV-induced carcinogenesis, in an unselected sample of Australian adults. Participants in the Nambour Skin Cancer Prevention Trial provided a dorsal hand punch biopsy which was used for immunohistochemical assessment of p53 immunoreactivity. Cross-sectional associations with serum fatty acid concentrations were analyzed in 139 participants, adjusting for confounding variables including skin phenotype, past sun exposure, and smoking status.

Results: There was an inverse association, showing a dose–response relationship, between total n-3 fatty acid serum concentrations and p53 immunoreactivity in the whole epidermis and the basal layer. This was particularly due to eicosapentanoic acid and docosahexanoic acid concentrations. There was no evidence for increased p53 immunoreactivity in participants with relatively high serum n-6 fatty acid concentrations. The ratio of n-3 to n-6 fatty acid concentrations was not associated with p53 immunoreactivity.

Conclusion: These results add to growing evidence that long-chain fatty acids may be able to modify early skin carcinogenesis.

Impact: The prospect that increased intake of n-3 fatty acids could help prevent skin cancer is attractive. Cancer Epidemiol Biomarkers Prev; 20(3); 530–6. ©2011 AACR.
Body Size, Physical Activity, and Risk of Triple-Negative and Estrogen Receptor–Positive Breast Cancer
Authors: Phipps Amanda I. , Chlebowski Rowan T. , Prentice Ross , McTiernan Anne , Stefanick Marcia L. , Wactawski-Wende Jean , Kuller Lewis H. , Adams-Campbell Lucile L. , Lane Dorothy , Vitolins Mara , Kabat Geoffrey C. , Rohan Thomas E. , Li Christopher I.
Published: March 2011

Background: Triple-negative breast cancer, characterized by a lack of hormone receptor and HER2 expression, is associated with a particularly poor prognosis. Focusing on potentially modifiable breast cancer risk factors, we examined the relationship between body size, physical activity, and triple-negative disease risk.

Methods: Using data from 155,723 women enrolled in the Women's Health Initiative (median follow-up, 7.9 years), we assessed associations between baseline body mass index (BMI), BMI in earlier adulthood, waist and hip circumference, waist–hip ratio, recreational physical activity, and risk of triple-negative (n = 307) and estrogen receptor–positive (ER+, n = 2,610) breast cancers.

Results: Women in the highest versus lowest BMI quartile had 1.35-fold (95% CI, 0.92–1.99) and 1.39-fold (95% CI, 1.22–1.58) increased risks of triple-negative and ER+ breast cancers, respectively. Waist and hip circumferences were positively associated with risk of ER+ breast cancer (Ptrend = 0.01 for both measures) but were not associated with triple-negative breast cancer. Compared with women who reported no recreational physical activity, women in the highest activity tertile had similarly lower risks of triple-negative and ER+ breast cancers (HR = 0.77; 95% CI, 0.51–1.13; and HR = 0.85; 95% CI, 0.74–0.98, respectively).

Conclusions: Despite biological and clinical differences, triple-negative and ER+ breast cancers are similarly associated with BMI and recreational physical activity in postmenopausal women. The biological mechanisms underlying these similarities are uncertain and these modest associations require further investigation.

Impact: If confirmed, these results suggest potential ways postmenopausal women might modify their risk of both ER+ and triple-negative breast cancers. Cancer Epidemiol Biomarkers Prev; 20(3); 454–63. ©2011 AACR.
Fumonisin B1 as a Urinary Biomarker of Exposure in a Maize Intervention Study Among South African Subsistence Farmers
Authors: van der Westhuizen Liana , Shephard Gordon S. , Burger Hester M. , Rheeder John P. , Gelderblom Wentzel C.A. , Wild Christopher P. , Gong Yun Yun
Published: March 2011

Background: The consumption of maize highly contaminated with carcinogenic fumonisins has been linked to high oesophageal cancer rates. The aim of this study was to validate a urinary fumonisin B1 (UFB1) biomarker as a measure of fumonisin exposure and to investigate the reduction in exposure following a simple and culturally acceptable intervention.

Methods: At baseline home-grown maize, maize-based porridge, and first-void urine samples were collected from female participants (n = 22), following their traditional food practices in Centane, South Africa. During intervention the participants were trained to recognize and remove visibly infected kernels, and to wash the remaining kernels. Participants consumed the porridge prepared from the sorted and washed maize on each day of the two-day intervention. Porridge, maize, and urine samples were collected for FB1 analyses.

Results: The geometric mean (95% confidence interval) for FB1 exposure based on porridge (dry weight) consumption at baseline and following intervention was 4.84 (2.87–8.14) and 1.87 (1.40–2.51) μg FB1/kg body weight/day, respectively, (62% reduction, P < 0.05). UFB1C, UFB1 normalized for creatinine, was reduced from 470 (295–750) at baseline to 279 (202–386) pg/mg creatinine following intervention (41% reduction, P = 0.06). The UFB1C biomarker was positively correlated with FB1 intake at the individual level (r = 0.4972, P < 0.01). Urinary excretion of FB1 was estimated to be 0.075% (0.054%–0.104%) of the FB1 intake.

Conclusion: UFB1 reflects individual FB1 exposure and thus represents a valuable biomarker for future fumonisin risk assessment.

Impact: The simple intervention method, hand sorting and washing, could positively impact on food safety and health in communities exposed to fumonisins. Cancer Epidemiol Biomarkers Prev; 20(3); 483–9. ©2011 AACR.
Radon and Lung Cancer in the American Cancer Society Cohort
Authors: Turner Michelle C. , Krewski Daniel , Chen Yue , Pope C. Arden , Gapstur Susan , Thun Michael J.
Published: March 2011

Background: Case–control studies conducted in North America, Europe, and Asia provided evidence of increased lung cancer risk due to radon in homes. Here, the association between residential radon and lung cancer mortality was examined in a large-scale cohort study.

Methods: Nearly 1.2 million Cancer Prevention Study-II participants were recruited in 1982. Mean county-level residential radon concentrations were linked to study participants according to ZIP code information at enrollment [mean (SD) = 53.5 Bq/m3 (38.0)]. Cox proportional hazards regression models were used to obtain adjusted HR and 95% CI for lung cancer mortality associated with radon. Potential effect modification by cigarette smoking, ambient sulfate concentrations, and other risk factors was assessed on both the additive and multiplicative scales.

Results: Through 1988, 3,493 lung cancer deaths were observed among 811,961 participants included in the analysis. A significant positive linear trend was observed between categories of radon concentrations and lung cancer mortality (P = 0.02). A 15% (95% CI, 1–31) increase in the risk of lung cancer mortality was observed per 100 Bq/m3 increase in radon. Participants with mean radon concentrations above the EPA guideline value (148 Bq/m3) experienced a 34% (95% CI, 7–68) increase in risk for lung cancer mortality relative to those below the guideline value.

Conclusions: This large prospective study showed positive associations between ecological indicators of residential radon and lung cancer.

Impact: These results further support efforts to reduce radon concentrations in homes to the lowest possible level. Cancer Epidemiol Biomarkers Prev; 20(3); 438–48. ©2011 AACR.
Racial Differences in the Incidence of Mesenchymal Tumors Associated with EWSR1 Translocation
Authors: Worch Jennifer , Cyrus Jobin , Goldsby Robert , Matthay Katherine K. , Neuhaus John , DuBois Steven G.
Published: March 2011

Background: The incidence of Ewing sarcoma varies by race, with very low rates among persons of African and East Asian ancestry. The incidence by race of other mesenchymal tumors that also harbor EWSR1 translocations has not been studied.

Methods: The SEER database was queried to find cases of mesenchymal tumors associated with EWSR1 translocations: Ewing sarcoma; clear cell sarcoma; extraskeletal myxoid chondrosarcoma; myxoid liposarcoma; desmoplastic small round cell tumor; and myoepithelial tumor. Age-adjusted incidence rates were calculated for white, African American, and Asian/Native American populations and compared statistically.

Results: Ewing sarcoma was significantly less common in the African American and Asian/Native American populations compared with the white population, with incidence rate ratios of 0.12 (95% CI, 0.08–0.20; P < 0.001) and 0.54 (95% CI, 0.41–0.69; P < 0.001), respectively. Desmoplastic small round cell tumor was significantly more common in the African American population compared with the white population (incidence rate ratio = 3.0; 95% CI, 1.62–5.49; P < 0.001). Myxoid liposarcoma was significantly less common in the Asian/Native American population compared with the white population (incidence rate ratio = 0.72; 95% CI, 0.56–0.92; P = 0.006). The incidence rates for extraskeletal myxoid chondrosarcoma, myoepithelial tumors, and clear cell sarcoma did not differ significantly by race.

Conclusions: Tumors associated with EWSR1 translocation are not uniformly more common in people of European ancestry.

Impact: The relationship between race and EWSR1 somatic translocation is complex. Future studies investigating the genetic epidemiology of EWSR1 translocated tumors are required. Cancer Epidemiol Biomarkers Prev; 20(3); 449–53. ©2011 AACR.
Results from a Dose–Response Study Using 3,3′-Diindolylmethane in the K14-HPV16 Transgenic Mouse Model: Cervical Histology
Authors: Sepkovic Daniel W. , Stein Johann , Carlisle Antoine D. , Ksieski H. Barbara , Auborn Karen , Raucci Laura , Nyirenda Themba , Bradlow H. Leon
Published: March 2011

The human papilloma virus is the major cause of cervical cancer. Viral infection initiates cervical intraepithelial neoplasia, which progresses through several stages to cervical cancer. The objective of this study is to identify the minimum effective dose of diindolylmethane that prevents the progression from cervical dysplasia to carcinoma in situ. We document cervical histology in K14-HPV16 mice receiving different doses of diindolylmethane. Urinary diindolylmethane concentrations are reported. Diindolylmethane could enhance the efficacy of human papilloma virus vaccines, creating a new therapeutic use for these vaccines in women already infected with the virus. Five doses (0–2,500 ppm) of diindolylmethane were incorporated into each mouse diet. The reproductive tract was serially sectioned and urine was obtained for analysis of urinary diindolylmethane. The results indicate that 62% of mice receiving 1,000 ppm diindolylmethane remained dysplasia-free after 20 weeks compared with 16% of mice receiving no diindolylmethane and 18% receiving 500 ppm; 1,000 ppm of 3,3′-diindolylmethane in the diet completely suppressed the development of cervical cancer. Urinary diindolylmethane levels increased significantly as diindolylmethane in food increased. These findings imply usefulness for diindolylmethane in the search to prevent cervical cancer when used in combination with prophylactic or therapeutic vaccines. Cancer Prev Res; 4(6); 890–6. ©2011 AACR.