bluuebunny/crossref_metadata_2025_split huggingface dataset:
AMPK synergizes with the combined treatment of 1′‐acetoxychavicol acetate and sodium butyrate to upregulate phase II detoxifying enzyme activities
Authors: Yaku Keisuke , Matsui‐Yuasa Isao , Konishi Yotaro , Kojima‐Yuasa Akiko 
Published: April 2013

ScopePhase II enzymes play important roles in detoxifying xenobiotics. We previously reported that both 1’‐acetoxychavicol acetate (ACA) and sodium butyrate individually increased phase II enzyme activities. Here, we determined the combined action of ACA and sodium butyrate on phase II enzyme activities in intestinal epithelial cells (IEC 6).Methods and resultsACA and sodium butyrate synergistically increased phase II enzyme activities. Protein levels of intranuclear transcription factor NF‐E2–related factor 2 (Nrf2) were increased by ACA or sodium butyrate treatment, but treatment with both did not produce a synergistic effect. Intranuclear p53 protein levels were increased by ACA but decreased by sodium butyrate alone or combined treatment with ACA and sodium butyrate. In contrast, p53 acetylation was promoted by sodium butyrate and the ACA and sodium butyrate combination. Inhibition of AMPK activity decreased phase II enzyme activities that were upregulated by treatment with ACA plus sodium butyrate or other phytochemicals, including kaempferol, quercetin, and epigallocatechin‐3‐gallate. Combined treatment with ACA and sodium butyrate increased phosphorylated AMPK levels.ConclusionThese results suggest that ACA and sodium butyrate synergistically contribute to xenobiotics metabolism. The combined ACA and sodium butyrate treatment synergistically upregulated phase II enzyme activities through AMPK activation and p53 acetylation.
Benzin aus Ether
Authors: Otto Thomas N. , Zimmermann Michael , Dinjus Eckhard , Ceccarelli Christina 
Published: April 2013

AbstractFlüssige Kohlenwasserstoffe für den Autotank lassen sich nicht nur aus Rohöl destillieren, sondern auch synthetisieren — aus Methanol zum Beispiel. Auch Dimethylether dient als Ausgangsprodukt. Modifizierte Zeolithe katalysieren die Reaktion.
Tanzelemente
Authors: Schoffers Elke 
Published: April 2013

AbstractDass es Chemiker gibt, die gerne tanzen, sollte niemanden wundern. Denn vor dem Klischee vom weltfremden Experimentator ohne Aussicht auf finanziellen Reichtum galt: Chemie ist Licht, Hoffnung und Fortschritt — und das wurde im Ballsaal gefeiert.
Spinat macht Skeptiker stark
Authors: Groß Michael 
Published: April 2013

AbstractSpinat enthält nicht viel mehr Eisen als andere grüne Gemüsesorten. Aber woher kam der Mythos vom außerordentlichen Eisenreichtum des Spinats, mit dem Generationen von Eltern ihre Kinder plagten? Waren ein Kommafehler oder das Trockengewicht des Grünzeugs schuld, und hat Popeye Beihilfe zur Irreführung der Kinder und Eltern geleistet?
Schweinefuttergrün war giftig
Authors: Guggolz Ernst 
Published: April 2013

AbstractDie freien Radikalen sind wieder da. Und die chemisch wie sprachlich bemerkenswerteren Unfälle. Insgesamt war die Ausbeute im letzten Jahr apriltechnisch nicht ganz so groß; dafür ließ die Qualität etwas nach. Nicht überraschend: der große Anteil von leicht vergänglichen Stilblüten aus dem Internet.
Biologisch basierte Basismoleküle
Authors: Riesmeier Jörg 
Published: April 2013

AbstractAus Biomasse hergestellte Bausteine für höherwertige Chemikalien und Produkte gibt es immer häufiger. Bereits heute sind zirka 13 Prozent der in der deutschen chemischen Industrie eingesetzten Rohstoffe biobasiert. Wie wird die Entwicklung weitergehen?
Produktionsanlagen im Wandel
Authors: Bug Thorsten 
Published: April 2013

AbstractFallende Anteile der europäischen Chemieindustrie am Weltmarkt bereiten Sorgen. Zunehmende Investitionen in Deutschland signalisieren allerdings eine hohe globale Wettbewerbsfähigkeit. Dabei erlebt die Basischemie überraschenderweise einen Aufschwung.
UHPLC‐HRMS‐Experimente planen und auswerten — Beispiel Thyroxin
Authors: Neu Volker , Bielow Chris , Schneider Peter , Braun Ralf , Stuppner Hermann , Reinert Knut , Huber Christian G. 
Published: April 2013

AbstractUltrahochleistungs‐Flüssigchromatographie und hochauflösende Massenspektrometrie geben neue und detaillierte Einblicke in die Zusammensetzung synthetischer pharmazeutischer Wirkstoffe. Die Geräte detektieren Spuren von Verunreinigungen und Abbauprodukten, und die Methoden machen Abbaumechanismen sichtbar.
A selective strategy for shakedown analysis of engineering structures
Authors: Simon J.‐W. , Kreimeier M. , Weichert D. 
Published: April 2013

SUMMARYDetermining the load‐bearing capacity of engineering structures is essential for their design. In the case of varying thermo‐mechanical loading beyond the elastic limit, the statical shakedown analysis constitutes a particularly suitable tool for this. The application of the statical shakedown theorem, however, leads to a nonlinear convex optimization problem, which is typically characterized by large numbers of variables and constraints. In the present work, this optimization problem is solved by a primal–dual interior‐point algorithm, which shows a remarkable performance due to its problem‐tailored formulation. Nevertheless, the solution procedure remains still a demanding task from computational point of view. Thus, the aim of this paper is to tackle the task of solving large‐scale problems by use of a new so‐called selective algorithm. This algorithm detects automatically the plastically most affected zones within the structure, which have the highest influence on the solution. The entire system is then reduced to a substructure consisting of these zones, based upon which a new optimization problem can be set up, which is solved with significantly less effort. Consequently, the running time decreases drastically, as is shown by application to numerical examples from the field of power plant engineering. Copyright © 2013 John Wiley & Sons, Ltd.
Sustaining International Partnerships: The European Master of Science Programme in Occupational Therapy, a Case Study
Authors: Ilott Irene , Kottorp Anders , la Cour Karen , van Nes Fenna , Jonsson Hans , Sadlo Gaynor 
Published: April 2013

AbstractInternational partnerships are a mechanism for supporting the academic development of occupational therapy and promoting cultural competence. This case study describes the factors that have helped to sustain a post‐qualifying programme implemented by five higher education institutions in Denmark, the Netherlands, Sweden, Switzerland and the UK since 1999. Data collection methods were documentary analysis and the reflections of a purposive sample of six key informants. Cohort and outcome data, from 193 students from 31 countries who enrolled between 1999 and 2011, are reported. Each cohort comprises students from an average of eight countries to optimize inter‐cultural dialogue. Four factors support sustainability. These are 1) supportive professional European networks; 2) timeliness and alignment with European higher education policy; 3) partnership structures and processes that emphasize joint decision making and accountability; and 4) the stimulus and satisfaction associated with internationalization. The main limitations are considering the OT‐EuroMaster as an intrinsic case study and using opportunistic data collection that undermines the rigor and transferability of the findings. Future opportunities include doctoral networks, transnational research and sharing our curricula design with other Regions to spread the collaborative, capacity building endeavours more widely. Copyright © 2013 John Wiley & Sons, Ltd.
Halo‐isocyanates as ‘transformation’ reagents
Authors: Bamsford Clement H. , Middleton Ian P. , Ai‐Lamee Kadem G. , Paprotny Jerzy 
Published: April 2013

AbstractThe advantages of halo‐isocyanates as ‘transformation’ reagents in the synthesis of block and graft copolymers are elaborated. These compounds permit polymeric blocks of vinyl units to be attached to a wide range of starting materials, natural or synthetic. Two stages are involved—isocyanation and grafting—and both may be carried out homogeneously or heterogeneously. Attention is here focused on poly(ether‐urethanes), e.g. Biomer, dextran and poly(ethylene glycol) to which chains of several water‐soluble polymers have been attached.
Morphologies and properties of polyblends. II: Blends of poly(methyl methacrylate) and a chlorine‐containing polycarbonate; effect of added copolymer
Authors: Eastmond G. C. , Jiang M. , Malinconico M. 
Published: April 2013

AbstractThis paper extends our previous study of the morphology and properties of polyblends of a polycarbonate and poly(methyl methacrylate) to an investigation of the influence of small amounts of added graft copolymer. The results demonstrate that, in spite of the complexity of the molecular species involved, graft copolymers can act as effective surfactants in polymer blends. The dominant effect is to form finer dispersions of one component in the other, with commensurate increases in interfacial area. A preliminary investigation of the influence of molecular parameters in the graft copolymer is reported; in all cases the molecular weight of the poly(methyl methacrylate) in the copolymer was kept constant and greater than that of the homopolymer whereas the molecular weight of the polycarbonate was varied. Finer dispersions and greater modifications to the relaxation behaviour were found as the molecular weights of the polycarbonate blocks in the copolymer increased and became comparable with the molecular weight of the homopolymer, and as the copolymer content increased.
Electron spin resonance studies of spin‐labelled polymers. 19. Spin‐labelled poly(vinyl acetate) plasticised with dibutyl phthalate
Authors: Cameron G. Gordon , Clark Peter W. , Bullock Anthony T. 
Published: April 2013

AbstractE.s.r. spectra of spin‐labelled poly(vinyl acetate) plasticised to varying extents with dibutyl phthalate have been analysed to yield the temperature, T50G, at which the separation of the extrema is 50 G. As in the case of spin‐probed, plasticised poly(vinyl acetate), the reciprocal of T50G shows a linear dependence on the weight fraction of polymer. This observation supports the view that in the region of T50G the label responds to the glass‐to‐rubber relaxation. At temperatures immediately below T50G the low‐field peak in the spectrum is split, indicating that motion of the label occurs with a distribution of correlation times.
Use of poly(styrene‐divinylbenzene) packing materials and tetrahydrofuran for the g.p.c. analysis of cellulose derivatives
Authors: Lloyd Linda L. , White Charles A. , Brookes Alan P. , Kennedy John F. , Warner Frank P. 
Published: April 2013

AbstractThe g.p.c. analysis of nitrate and tricarbanilate derivatives of cellulose is described for the determination of molecular weight distribution. The method uses macroreticular poly(styrene‐divinylbenzene) packing materials with tetrahydrofuran as eluent. The full molecular weight distribution analysis with a three‐column system takes less than 30 min, making the method additionally suitable for the monitoring of industrial nitration processes. A simpler two‐column system is also described which is suitable for the analysis of lower molecular weight materials with improved resolution.
Lithiation, mercuriation, and thalliation of poly(N‐vinylcarbazole): Chemical transformations of the products
Authors: Al‐Kadhumi Ahmed A. H. A. , Hodge Philip , Thorpe F. Gordon 
Published: April 2013

AbstractN‐Vinylcarbazole was homopolymerised or was copolymerised with divinylbenzene (2% and 4%) using AIBN as initiator. The linear homopolymer was shown not to undergo direct lithiation using n‐butyllithium, but lithiation was achieved using n‐butyllithium and brominated linear poly(N‐vinylcarbazole). The polymers reacted smoothly with mercury (II) acetate or trifluoroacetate in THF or dichloromethane to give mercuriated polymers with high degrees of substitution (approx. 80%); with thallium (III) trifluoroacetate in dichloromethane a thalliated polymer was formed, but with a lower degree of substitution (approx. 20%). The mercuriated and thalliated polymers reacted with iodine (or potassium iodide) to give polymers containing an iodo‐substituent. All the metallated polymers reacted with borane to give polymer‐supported organoboranes which, on treatment with water or alkaline hydrogen peroxide, gave polymers containing boronic acid residues or phenolic residues, respectively. The lithio‐substituent in the linear polymer was converted into chloromercury and carboxylic acid groups.
Radical copolymerisation of maleic anhydride with trans‐stilbene
Authors: Ebdon John R. , Hunt Barry J. , Hussein Shamima 
Published: April 2013

AbstractRadical copolymerisations of maleic anhydride and trarcs‐stilbene have been carried out in methyl ethyl ketone at 60°C using 2,2′‐azo‐bis‐isobutyronitrile as initiator. The copolymers formed at all feeds are slightly rich in maleic anhydride units but are heterogeneous with regard to both composition and molecular weight distribution. It is concluded that this effect is probably produced by phase separation during the copolymerisation and that any interpretation of copolymerisation rates or copolymer compositions in terms of mechanism is not straightforward.
Poly(n‐butyl α‐cyanoacrylate): A highly sensitive and high contrast resist for electron‐beam and X‐ray lithography
Authors: Eranian Armand , Datamanti Evelyne , Dubois Jean‐Claude , Serre Brigitte , Schué Francois , Montginoul Claude , Giral Louis 
Published: April 2013

AbstractHigh molecular weight poly(n‐butyl α‐cyanoacrylate) has been obtained by zwitterionic polymerization. This polymer exhibits sensitivity to an electron beam (20 keV) about 25 times higher than that of PMMA, with a contrast of 3, and a sensitivity to X‐rays (λ = 13−34 Å) about 15 times higher than that of PMMA, with a contrast of 2 3.
Block polymerisation by interfacial coupling of immiscible polymers bearing mutually reactive end‐groups: Interfacial activity of ω‐functionalised polymers
Authors: Paulus Gerard , Jérôme Robert , Teyssié Philippe 
Published: April 2013

AbstractThe coupling of polymers bearing mutually reactive groups is generally prevented by the low concentration of end‐groups and the immiscibility of the polymers. This can be overcome by an interfacial technique concentrating the reactive groups in the interfacial region. This paper focuses on the effect that an end‐group has on the behaviour of a polymer of opposite philicity at a water‐toluene interface. Measurements of the reduction in interfacial tension promoted by poly(ethylene oxide) (PEO) end‐capped by a hydrophobic C10H18 group, and polystyrene (PS) terminated by an ammonium bromide group shed light on the role played by the end‐group in the polymer adsorption. Values of the equilibrium interfacial tension support the conclusion that the adsorption of the hydrophilic polymer (PEO) is largely independent of the C10H18 end‐group whereas the ammonium bromide effectively drives PS to the interfacial region.
Langmuir—Biodgett supermolecular assemblies
Authors: Barraud Andre 
Published: April 2013

AbstractMolecular electronics and biomimetic chemistry are two promising fields of research which involve micro‐machineries at a molecular level. Such molecular assemblies have to be designed for a specific function and to exhibit selective properties. The Langmuir‐BIodgett (L.B.) method is the simplest and the best suited method to build up molecular assemblies tailored for a specific purpose.Two examples of molecular assemblies are presented to illustrate the high versatility of this supermolecular engineering: the dioxygen trap, based on alternate L.B. layers, which exhibits biomimetic chemical properties; and lamellar conductors, which make extensive use of semi‐amphiphilic compounds and chemical film manipulations and are tailored for electronic properties.The advantages of combining solid state chemistry and semi‐amphiphilic compounds are analysed and emphasised.
Cross‐linkable polyester imides
Authors: Serna Felipe J. , de Abajo Javier , de la Campa José G. 
Published: April 2013

AbstractAromatic polyesters containing imide pendant groups have been prepared from diphenols and 5‐imidoisophthaloyl chlorides by the interfacial polycondensation method. Linear polyesters without substituents have also been synthesized by the same method for comparative purposes.The presence of side imide groups enhances the solubility of aromatic polyesters in organic solvents, and the thermal properties are greatly affected, with increases in the glass transition temperatures of up to 60°C, while the thermal resistance (t.g.a.) seems not to be so greatly affected.When the imide pendant groups are unsaturated, as derived from maleimide, nadimide and tetrahydrophthalimide, the polyesters can be converted into crosslinked materials by means of the appropriate thermal treatment, either as a polymeric powder or as films. Properties such as solubility, thermal resistance and mechanical strength were investigated before and after the cross‐linking reaction.
Solution properties of polyelectrolytes. I. Exclusion chromatography of sodium polystyrene sulphonate in salt‐free water as eluent
Authors: Abad Concepción , Braco Lorenzo , Soria Vicente , García Rosa , Campos Agustín 
Published: April 2013

AbstractThe effect of concentration of sodium polystyrene sulphonate on the elution volume in exclusion chromatography has been investigated using salt‐free water as eluent. A non‐linear increase in the elution volume has been observed with increasing injected sample concentration. Concentration‐dependent calibrations have been obtained which approach the universal calibration for uncharged polymers (dextrans) as polyelectrolyte concentration increases. The separation mechanisms are interpreted in terms of electrostatic and hydrodynamic interactions. A semi‐empirical model is proposed to predict concentration effects of linear polyions in exclusion chromatography and good agreement has been found between experimental and calculated elution volumes.
Behaviour of composites used in the confinement of nuclear wastes. 3. Diffusion of ions through epoxide networks
Authors: Nicaise Elisabeth , Gandini Alessandro , Cheradame Hervé 
Published: April 2013

AbstractThe diffusion of cesium and chloride ions through epoxide membranes was studied under a variety of conditions including self‐diffusion, the presence of other salts in the aqueous solution, an excess of either reagent used in the manufacture of the membrane, the addition of various fillers in the epoxide network and two temperatures. At 23°C, the diffusion coefficient D was (2–6) × 10‐13cm2s−1 for most systems, except when the epoxide was prepared with an excess of the dioxirane component or when untreated glass beads were added to the network. In the latter instance D increased and most notably with glass beads. On the contrary, addition of sand to the epoxide resulted in a more effective barrier against diffusion as shown by a decrease in D. It is concluded that most of these materials should be suitable for the confinement of low and medium activity nuclear wastes.
Photoluminescence and Raman spectroscopy of Cd(S,Se) under hydrostatic pressure
Authors: Sander Thomas , Rinn Markus S. , Klar Peter J. 
Published: April 2013

AbstractA series of Cd(S,Se) crystals grown by a sublimation method ranging from pure CdS to CdSe were investigated by photoluminescence (PL) and Raman spectroscopy under hydrostatic pressure. The ternary alloy Cd(S,Se) crystallizes in a direct bandgap wurtzite structure at ambient pressure. It undergoes a phase transition to an indirect bandgap rocksalt structure between a pressure of 2 and 3.5 GPa. According to group theory the wurtzite structure possesses four Raman modes whereas the rocksalt structure does not exhibit any active first order Raman modes. Upon release of pressure the Raman signals are recovered whereas the PL signals do not reappear. This may indicate that small domains with rocksalt structure still exist after cycling through the phase transition and thus lead to a nonradiative recombination. The pressure dependence of the longitudinal optical phonons of the ternary alloy were estimated. The pressure slopes tend to increase with the selenium concentration in the samples. This effect can be explained by changing of the bulk modulus from small for CdSe to large for CdS. Furthermore, Grüneisen parameters have been calculated for Cd(S,Se), assuming a linear relationship between the bulk moduli of the pure materials CdS and CdSe.
Formation of the defect halo of swift heavy ion tracks in LiF due to spatial redistribution of valence holes
Authors: Medvedev N. A. , Schwartz K. , Trautmann C. , Volkov A. E. 
Published: April 2013

AbstractThe fundamental effect of the relaxation kinetics of the ensemble of generated valence holes on structure transformations in swift heavy ions tracks in alkali halides is demonstrated. The parameters of the spatial distributions of F‐color centers formed in the nanometric vicinities of the trajectories of different ions (from C to U) decelerated in LiF in the electronic stopping regime were extracted from the in situ spectroscopy experiments. Formation of these defects results from self‐trapping of valence holes appearing during material ionizations followed by creation and decay of self‐trapped excitons. The Monte‐Carlo model is applied in order to determine the initial radial distributions of valence holes in tracks of different ions. The detected large difference between the hole and defect distributions indicates fast and long‐range diffusion of valence holes from the ion trajectory before their self‐trapping. The averaged diffusion coefficient (Dh) of hot holes at the subpicosecond time scale after the projectile passage as well as the conversion efficiencies of valence holes into color centers (β) in relaxing tracks of different ions are estimated (Dh = 0.016–1.4 cm2 s−1, β = 0.01–0.04).
The apparent paradox of maternal seropositivity as a risk factor for congenital cytomegalovirus infection: a population‐based prediction model
Authors: de Vries Jutte J. C. , van Zwet Erik W. , Dekker Friedo W. , Kroes Aloys C. M. , Verkerk Paul H. , Vossen Ann C. T. M. 
Published: April 2013

SUMMARYBecause maternal seropositivity for CMV is associated with substantial protection against congenital CMV infection, prevention measures have focused mainly on seronegative pregnant women for decades. However, population‐wide insight in the contribution of nonprimary infection (reactivation and/or re‐infection with a different strain) on the most common sequela, hearing loss, is missing.A population‐based prediction model was developed to estimate the proportion of congenital CMV‐related hearing loss resulting from nonprimary maternal infection. Incorporated was a meta‐analysis of the risk of hearing loss, calculating pooled proportions of children with hearing loss after nonprimary and primary infection. Subsequently, the model was applied for worldwide present population seroprevalences (range 30–95%).It was estimated that, for all population seroprevalences, nonprimary maternal infections are responsible for the majority of congenital CMV infections. This proportion increased with seroprevalence, ranging from 57% (95%CI 24–85%) to 96% (95% CI 88–99%) for seroprevalences of 30% to 95%. Our meta‐analysis (six reports) showed that the risk of hearing loss after nonprimary infection was 11% (28/253 children, 95% CI 7–15%) versus 13% (50/385 children, 95% CI 10–16%) after primary infection. Incorporating this risk into our model, we estimated that nonprimary infections also accounted for the majority of CMV‐related hearing loss. This proportion ranged from 53% (95% CI 13–86%) to 95% (95% CI 62–99%) for seroprevalences of 30% to 95%.Our data underline the worldwide contribution of nonprimary infections in causing CMV‐related hearing loss. These results imply that prevention research such as vaccine and hygiene studies should not only be directed at seronegative but also seropositive pregnant women. Copyright © 2013 John Wiley & Sons, Ltd.