bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethanol stimulates tumor progression and expression of vascular endothelial growth factor in chick embryos
Authors: Gu Jian‐Wei , Bailey Amelia Purser , Sartin Amanda , Makey Ian , Brady Ann L.
Published: December 2004

BACKGROUND

The mechanisms by which alcohol consumption causes cancer have not been established due to a lack of experimental studies.

METHODS

A chick embryo chorioallantoic membrane (CAM) model that bore human fibrosarcoma (HT1080) was used to determine whether the administration of physiologically relevant doses of ethanol could stimulate tumor growth, angiogenesis, metastasis, and vascular endothelial growth factor (VEGF) expression in tumors. HT1080 cells were inoculated onto the “upper CAM” on Day 8, saline or ethanol was administrated at a dose of 0.25g/kg per day on the CAM, and the tumors were harvested on Day 17. VEGF mRNA and protein were determined by Northern blot analysis and enzyme‐linked immunosorbent assay. Intratumoral vascular volume density (IVVD) was determined by point counting on periodic acid–Schiff‐stained sections. Intravasation of HT1080 cells was determined using human‐Alu polymerase chain reaction analysis. The effects of ethanol on VEGF expression and cell proliferation were examined in cultured HT1080 cells.

RESULTS

Ethanol treatment for 9 days caused a 2.2‐fold increase in tumor volume (867 ± 138 mm3 vs. 402 ± 28 mm3), a 2.1‐fold increase in IVVD (0.021 ± 0.004 mm3/mm3 vs. 0.010 mm3/mm3 ± 0.002 mm3/mm3), and a significant increase in VEGF mRNA or protein expression in tumors compared with a group of control embryos (n = 6 embryos; P < 0.01). Ethanol treatment caused an increase > 8‐fold in the intravasated HT1080 cells in the CAM group compared with the control group (n = 6 embryos; P < 0.01). Physiologically relevant levels of ethanol (10 mM and 20 mM) caused a dose‐related increase in VEGF mRNA and protein expression in cultured HT1080 cells. The ethanol–HT1080‐conditioned media increased the proliferation of endothelial cells, but not of HT1080 cells.

CONCLUSIONS

The findings suggest that the induction of angiogenesis and VEGF expression by ethanol represents an important mechanism of cancer progression associated with alcoholic beverage consumption. Cancer 2005. © 2004 American Cancer Society.
EPR Characterisation of CuII Complexes of Poly(propylene imine) Dendromesogens: Using the Orienting Effect of a Magnetic Field
Authors: Domracheva Natalia , Mirea Anisoara , Schwoerer Markus , Torre‐Lorente Laura , Lattermann Günter
Published: December 2004

Liquid‐crystalline derivatives of poly(propylene imine) dendrimers of the 0th, 1st and 2nd generations, complexed with copper(II) ions, were studied by EPR spectroscopy. The structures of copper(II) complexes with different CuII loadings x per dendrimer ligand L (x=Cu/L) were determined. At the lowest concentration, the CuII ions form monomeric complexes with approximately square‐planar N2O2 coordination of both carbonyl oxygen and amido nitrogen atoms. At higher copper content, two kinds of CuII complex sites with different geometries exist. The orienting effect of a high magnetic field was used to investigate the structure and magnetic properties of the copper(II) complexes. This effect, for the first time in dendrimers, allowed the resolution of five nitrogen super‐hyperfine lines on gz components with the unusual coupling constant of aNz=35.9×10−4 cm−1. The combination of the magnetic parameters and the orienting effect indicates the presence of a monomeric complex with pseudotetrahedral N2O2 coordination of the CuII ion, as well as a “dimer” structure with fivefold coordination, presumably due to an N3O2 environment. Higher copper loadings lead to increased exchange coupling between the complex sites.
What Do a Foam Film and a Real Gas Have In Common?
Authors: Stubenrauch Cosima
Published: December 2004

The stability of well‐drained quasistatic foam films (thickness <100 nm) is usually discussed in terms of surface forces, which create an excess pressure normal to the film interfaces, called the disjoining pressureΠ. The disjoining pressure is the sum of repulsive electrostatic (Πelec), attractive van der Waals (ΠvdW), and repulsive steric (Πsr) forces on the assumption that structural forces can be neglected. On the basis of these forces two different types of thin foam films are distinguished, namely common black films (CBF), which are mainly stabilized byΠelec, and Newton black films (NBF), the stability of which is determined byΠsr. With a thin‐film pressure balance (TFPB) the thicknesshof a foam film can be measured as a function of the applied pressure from which the disjoining pressureΠcan be calculated. A thorough analysis of the results published so far reveals that theΠ–hcurves of nonionic surfactants measured at different surfactant concentrations resemblep–Vmisotherms of a real gas measured at different temperatures. On the basis of these observations the van der Waals description of a real gas can be applied to foam films and a phase diagram for a foam film was constructed using the Maxwell construction.
Solid‐State Structure, Quantum Calculations and Spectroscopic Characterization of the Hydrogen‐Bonded Complex [Os(bpy)2(CO)(EtO···H‐DMAP)][PF6]2
Authors: Garino Claudio , Gobetto Roberto , Nervi Carlo , Salassa Luca , Croce Gianluca , Milanesio Marco , Rosenberg Edward , Ross J. B. Alexander
Published: December 2004

The new H‐bonded complex [Os(bpy)2(CO)(EtO···H‐DMAP)][PF6]2, where DMAP = 4‐(dimethylamino)pyridine and bpy = 2,2′‐bipyridine, has been synthesized and characterized by X‐ray diffraction, IR, solution and solid‐state NMR spectroscopy. The complex shows a strong hydrogen bond between the protonated DMAP moiety and the deprotonated ethanolic group directly bonded to the Os atom. High‐speed (28 KHz) solid‐state1H MAS NMR spectroscopy and quantum‐mechanical calculations were used to assess the location of the hydrogen atom involved in the H‐bond. Both confirmed a proton characteristic of an N−H···O−Y hydrogen bond. A molecular orbital analysis was performed to elucidate the IR CO stretching frequency red shift of the H‐bonded complex with respect to [Os(bpy)2(CO)O(H)Et][OTf]2. Absorption spectra indicate that the H‐bond is present both in water and dichloromethane solutions. However, no direct evidence of the H‐bond interaction in solution is observed from the1H NMR spectrum (CD2Cl2) between 298 and 193 K. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Two‐stage synthesis of sorbitan esters, and physical properties of the products
Authors: Smidrkal Jan , Cervenkova Radka , Filip Vladimir
Published: December 2004

A series of sorbitan‐fatty acid esters with various fatty acid/sorbitol ratios was prepared using a 2‐stage process. In the first stage, sorbitol was dehydrated to sorbitan at 180 °C (using phosphoric acid as catalyst), and in the second stage, the sorbitan was esterified with the fatty acid at 220 °C (sodium hydroxide as catalyst). The course of the reaction was monitored and the composition of final products was determined by thin‐layer chromatography using a flame‐ionisation detector (TLC‐FID). The properties (surface tension, melting points, viscosity) of prepared sorbitan esters depend on the molecular ratio of fatty acid and sorbitol. The described method is suitable for the preparation of sorbitan esters at industrial scale.
Alcoholysis of waste fats with 2‐ethyl‐1‐hexanol using Candida antarctica lipase A in large‐scale tests
Authors: Brenneis Rudolf , Baeck Burkhard , Kley Gerd
Published: December 2004

Commercial native lipase A from Candida antarctica was used to produce alkyl esters through the alcoholysis of (waste) fats with 2‐ethyl‐1‐hexanol. The process was carried out in batch stirred tank reactors (from 100 mL up to 3000 L).

The content of alkyl esters in reaction mixtures was determined by gradient HPLC using an evaporative light scattering detector and the reaction progress was controlled by determining the ratio of the palmitic acid ester peak area to the oleic acid ester peak area in HPLC chromatograms.

The results show that alcoholysis is the favoured reaction in presence of excess water and water‐insoluble alcohols in comparison with hydrolysis (fatty acid content <5%). The optimum amount of water for the alcoholysis was found to be 80–100% of the amount of fat. In the presence of low quantities of water both alcoholysis and hydrolysis are slow.

Conversion rate increases with increasing temperature to 65–70 °C.

Based on these results a large‐scale test to produce 3000 L of alkyl ester (to be used as lubricant coolant) was carried out. The experiments have proved that alcoholysis is completed after about 7–10 h depending on temperature.
Recent advances in microemulsion electrokinetic chromatography
Authors: Marsh Alex , Clark Brian , Broderick Margo , Power Joe , Donegan Sheila , Altria Kevin
Published: December 2004

Microemulsion electrokinetic chromatography (MEEKC) is an electrodriven separation technique. Separations are typically achieved using oil‐in‐water microemulsions, which are composed of nanometre‐sized droplets of oil suspended in aqueous buffer. The oil droplets are coated in surfactant molecules and the system is stabilised by the addition of a short‐chain alcohol cosurfactant. The novel use of water‐in‐oil microemulsions for MEEKC separations has also been investigated recently. This report summarises the different microemulsion types and compositions used to‐date and their applications with a focus on recent papers (2002–2004). The effects of key operating variables (pH, surfactant, cosurfactant, oil phase, buffer, additives, temperature, organic modifier) and methodology techniques are described.
The combination of flow injection with electrophoresis using capillaries and chips
Authors: Chen Xingguo , Fan Liuyin , Hu Zhide
Published: December 2004

The combined flow injection capillary electrophoresis (FI‐CE) system that integrates the essential favorable merits of FI and CE, can significantly expand the application scope of CE by exploring the various on‐line sample pretreatments and preconcentration of FI. The principle behind this technique, some innovative designs of the split‐flow interface, as well as novel applications to a variety of analytical problems, are reviewed and discussed. Some salient features and unique advantages of this technique are outlined.
Dual injection capillary electrophoresis: Foundations and applications
Authors: Priego‐Capote Feliciano , Luque de Castro Maria D.
Published: December 2004

The state of the art of capillary electrophoresis (CE) approaches based on dual injection is here reported. Dual injection strategies have been proposed with three main objectives: (i) to provide information about reaction kinetics and/or related parameters, (ii) to perform in‐capillary derivatization for improving separation and/or determination, (iii) to develop electrophoretic methods for the simultaneous analysis of anionic and cationic compounds. For the first two purposes, dual injection, which involves sample and reagent, can be realized either from the same end of the capillary (electrophoretically mediated microanalysis, EMMA) or from the two ends of the capillary (electroinjection analysis, EIA). The third objective, with dual injection of sample from the two ends of the capillary, takes advantage of moving cationic and anionic compounds with opposite directions. The foundations of each alternative, conditions necessary for working with them, restrictions, applications as well as perspectives are reviewed in order to establish the advantages, shortcomings, and convenience or no of their use in comparison to conventional CE.
The GEOTOP snow module
Authors: Zanotti Fabrizio , Endrizzi Stefano , Bertoldi Giacomo , Rigon Riccardo
Published: December 2004

A snow accumulation and melt module implemented in the GEOTOP model is presented and tested. GEOTOP, a distributed model of the hydrological cycle, based on digital elevation models (DEMs), calculates the discharge at the basin outlet and estimates the local and distributed values of several hydro‐meteorological quantities. It solves the energy and the mass balance jointly and deals accurately with the effects of topography on the interactions among radiation physics, energy balance and the hydrological cycle. Soil properties are considered to depend on soil temperature and moisture, and the heat and water transfer in the soil is modelled using a multilayer approach. The snow module solves for the soil–snow energy and mass exchanges, and, together with a runoff production module, is embedded in a more general energy balance model that provides all the boundary conditions required. The snowpack is schematized as a single snow layer where a limited number of physical processes are described. The module can be seen essentially as a parameter‐free model. The application to an alpine catchment (Rio Valbiolo, Trentino, Italy), monitored by an in situ snow‐depth sensor, is discussed and shown to give results comparable to those of more complex models. Copyright © 2004 John Wiley & Sons, Ltd.
Effects of LDL‐immunoapheresis on plasma concentrations of vitamin E and carotenoids in patients with familial hypercholesterolemia
Authors: Cauza Edmund , Jansen Martin , Resch Ulrike , Dunky Attila , Derfler Kurt , Winklhofer‐Roob Brigitte M. , Kostner Karam
Published: December 2004

Recently very potent extracorporeal cholesterol‐lowering treatment options have become available for patients with hypercholesterolemia. LDL immunoapheresis treatment selectively removes LDL and lipoprotein(a) from the circulation. Since LDL is the major carrier of lipophilic antioxidants in plasma, the purpose of the present study was to assess the effects of a single LDL apheresis treatment on plasma concentrations of tocopherols (α‐ and γ‐tocopherol) and carotenoids (α‐ and β‐carotene, zeaxanthin, cryptoxanthin, canthaxanthin, lycopene, and retinol). Plasma antioxidant concentrations were determined by HPLC in 7 patients with familial hypercholesterolemia before and after LDL immunoapheresis treatment. Plasma concentrations of both α‐ and γ‐tocopherol and the different carotenoids were significantly reduced by LDL apheresis. However, when standardized for cholesterol to adjust for cholesterol removal, α‐ and γ‐tocopherol, retinol, and the more polar carotenoids lutein and zeaxanthin increased in response to apheresis treatment, while the more unpolar carotenoids such as β‐carotene and lycopene did not change. These data demonstrate that a single LDL immunoapheresis treatment affects tocopherols and individual carotenoids differently. This may be explained by differences in chemical structure and preferential association with different lipoproteins. These results further imply that tocopherols, lutein, zeaxanthin, and retinol, are associated in part with lipoproteins and other carriers such as retinol‐binding protein that are not removed during apheresis treatment. J. Clin. Apheresis 19:174–179, 2004. © 2004 Wiley‐Liss, Inc.
New Fluorinated Thermoplastic Elastomers, 4
Authors: Andre Sébastian , Guida‐Pietrasanta Francine , Rousseau Alain , Boutevin Bernard , Caporiccio Gérardo
Published: December 2004

Summary: The synthesis of fluorinated polyimide‐polyhybridsiloxane block copolymers (FPI‐HPHSX) was performed by polycondensation of α,ω‐dichlorosilane fluorinated polyimides (SiCl‐FPI) and α,ω‐disilanol‐polyhybridsiloxanes (SiOH‐HPHSX). The α,ω‐disilanol polyhybridsiloxanes were synthesized by polyhydrosilylation between 1,7‐octadiene and hexamethyltrisiloxane (HMTS). The resulting siloxanes exhibit a glass transition temperature close to −98 °C. The α,ω‐dichlorosilane fluorinated polyimide was prepared by hydrosilylation of α,ω‐diallyl fluorinated polyimide and dimethylchlorosilane in the presence of Karstedt's catalyst. Then a series of four FPI‐HPHSX was synthesized by polycondensation and, with tuning of the number average molecular weight ($\overline M _{\rm n}$) of the soft polyhybridsiloxane and the hard polyimide groups, they were characterized. The influence of the segment lengths on the behavior (surface tension and thermal stability) of the thermoplastic elastomer (TPE) material was studied. The FPI‐HPHSX block copolymers' thermomechanical properties are also reported and discussed.

General procedure for the synthesis of alternating block copolymers FPI‐HPHSX by polycondensation.

magnified image

General procedure for the synthesis of alternating block copolymers FPI‐HPHSX by polycondensation.
1H and 13C spectral assignments of 7β‐(cinnamoyl‐substituted)amino‐3‐acetoxymethyl‐cephalosporins
Authors: López Miguel A. , Rodríguez Zalua , González Maritza , Tolón Blanca , Avila Rizette , Mamposo Taimirys , Vélez Hermán , Fini Adamo
Published: December 2004

The 1H and 13C spectroscopic data for 7β‐(cinnamoyl‐substituted)amino‐3‐acetoxymethyl‐cephalosporins were fully assigned by a combination of one‐ and two‐dimensional experiments. Substitution on the aromatic ring and on the double‐bond α‐position of the cinnamoyl moiety has little influence on the spectroscopic properties of the 7β‐aminocephalosporanic acid parent moiety. Copyright © 2004 John Wiley & Sons, Ltd.
The (3,4) Mode Interaction in the GeoFlow Framework
Authors: Beltrame Philippe , Egbers Christoph
Published: December 2004

The problem of convection in a self‐gravitating spherical shell of fluid is commonly encountered in sciences like astrophysics and geophysics (earth's liquid core). The GEOFLOW‐experiment is a project of the European Space Agency in order to perform the spherical Rayleigh‐Bénard convection problem on the International Space Station in a micro‐gravity environment: the central force field is simulated by a dielectrophoretic one. Beyond a critical Rayleigh number Rac, generically an unique spherical ℓ mode becomes unstable and only stationary or travelling waves solutions are expected near the onset. But, for a critical aspect ratio ηc two consecutive modes (ℓ, ℓ + 1) are unstable. The (1,2) and (2,3) interactions have showed a rich bifurcation diagram, in particular, we have found heteroclinic cycles predicted by the theoretical study. Because of the experiment requirements, only the (3,4) one is possible. So, this paper purposes to analyse this bifurcation in non‐rotating case in the GEOFLOWframework using the theory of bifurcation with the spherical symmetry.
Numerical simulation of 1‐D incompressible laminar micro‐flow convection behaviour with temperature dependent fluid properties
Authors: Mahulikar S. P. , Herwig H. , Hausner O. , Kock F.
Published: December 2004

This paper investigates the qualitative behaviour of single‐phase laminar convection for microchannels and conventionallysized channels formed between two parallel plates, captured by a numerical simulation on water flow. The convection parameters are obtained by separate numerical calculations on a series of parallel plates at constant temperatures. The pairs of parallel plates are maintained at progressively greater temperatures, to simulate the condition of increasing fluid temperature in a channel. The governing one‐dimensional (1‐D) momentum and energy equations are formulated to incorporate the dependence on temperature of both fluid viscosity (μ) and thermal conductivity (k). The qualitative behaviour of Nusselt number (Nu) decreasing with increasing Reynolds number (Re), exhibited by reported experimental data in literature, is simulated. Results show that it is practically dif_cult to observe this behaviour in the conventionally‐sized channels, but the effect easily surfaces in microchannels for practical lengths of flow and allowable high heat flux (q″W). (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Isotropic models for a heat transfer in periodic composites
Authors: Wierzbicki Ewaryst , Siedlecka Urszula
Published: December 2004

A macroscopic model for the non – stationary heat transfer processes in a periodic honeycomb – type anisotropic rigid conductor is formulated. The main aim of this contribution is to show that the macroscopic properties of this conductor are isotropic. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Experiments on baroclinic instabilities
Authors: von Larcher Th. , Beyer W. , Egbers C.
Published: December 2004

We study experiments on baroclinic instabilities in a different heated rotating annulus cooled from within. Characteristic time series of the flow velocity are measured with the Laser–Doppler–Velocimetry (LDV) technique. The surface flow is observed with a co–rotating camera. Steady waves as well as complex flow states are observed. Hysteresis is also found. The drift rate of stable baroclinic waves is determined. The methods of non–linear time series analysis are used to investigate the dynamics of baroclinic waves, particulary in transition zones between different flow regimes. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Taylor‐Couette Strömung von Nichtnewtonschen Fluiden
Authors: Smieszek M. , Farnik J. , Egbers C.
Published: December 2004

Es wird das Strömungsverhalten von einem Newtonschen und einem Nichtnewtonschen Fluid im Taylor‐Couette System untersucht. Für beide Fluide werden Stabilitätsdiagramme aufgenommen. Das Nichtnewtonsche Fluid basiert auf einer Saccharoselösung und einem Polyacrylamid. Als Newtonsches Fluid wird ein Silikonöl (Baysilone M3) eingesetzt. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A ray‐integral solution for the wave‐field in the Sommerfeld model
Authors: Borejko Piotr
Published: December 2004

A ray‐integral solution is presented for the wave‐field in the Sommerfeld model (liquid half‐space over solid half‐space), where a point source is placed in the fluid and the two media (fluid and solid) of contrasting densities and wave speeds are homogeneous. This exact closed form solution is then used to evaluate complete time records of the acoustic pressure (at a point receiver located in the fluid in the vicinity of the penetrable fluid‐solid interface) for two Sommerfeld models: one where the shear wave speed in the solid bottom is lower than the sound speed in the fluid and the other where the shear wave speed is higher. These pressure response curves indicate the relative importance of the various wave‐forms (the critically refracted longitudinal and shear waves, the pseudo‐Rayleigh and Stoneley interface waves, the direct wave, and the totally reflected wave) contributing to the solution and the possibility of utilizing the arrival times of the refracted and interface waves to determine the bottom rigidity. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sound Insulation of Porous Plates
Authors: Busse Anke , Schanz Martin
Published: December 2004

Because of the still increasing noise pollution the numerical simulation of acoustic problems becomes more and more important. One essential aspect is the numerical treatment of noise insulation of solid walls. The main noise source is the bending vibration of separating components. In general, they consist of porous material, e.g., concrete or bricks. To take into account the porous structure as well as the damping effect of the porosity of these components a poroelastic plate theory is developed. The Finite Element implementation of this plate theory shows the importance of taking porous materials into account. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
FEM–BEM–Kopplung und strukturakustische Sensitivitätsanalyse f ür Schalengeometrien
Authors: Fritze Denny , Marburg Steffen , Hardtke Hans‐Jürgen
Published: December 2004

Durch lokale Veränderungen der Geometrie kann bei Schalen direkt in die Steifigkeit und somit in das Schwingungsverhalten bzw. die Schallemission eingegriffen werden. In der gradientenbasierten strukturakustischen Optimierung stellt allerdings die Sensitivitätsanalyse den zeitaufwendigsten Teil dar. Es wird ein Konzept vorgestellt, welches die Schalengeometrie parametrisiert, die Fluid‐Struktur‐Kopplung vereinfacht und strukturelle Sensitivitäten effizient bestimmt. Dabei wird für die Strukturanalyse die Finite‐Elemente‐Methode und für die akustische Simulation die Randelementemethode verwendet. Beide Verfahren werden dann so gekoppelt, daß an der Schnittsteile nichtidentische Diskretisierungen beider Modelle zugelassen werden. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Composite beams with shape memory alloy fibres
Authors: Kuczma Mieczysław S.
Published: December 2004

We are concerned with the bending problem of fibrous composite beams in which fibres are made of shape memory alloys. These are alloys that may undergo a stress‐induced martensitic phase transformation. The matrix is treated as an elastic medium, and perfect bonding between matrix and fibres is supposed. In our model, the beam is decomposed into layers and the hysteretic behaviour of the shape memory fibres is taken into account. The boundary value problem is formulated in the form of an evolution variational inequality which, after finite element discretization, can be solved incrementally as a sequence of linear complementarity problems. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of filler size and heat treatment on the crystallization behavior of glass bead‐filled polypropylene
Authors: Yuan Qiang , Jiang Wei , An Lijia , Li R. K. Y.
Published: December 2004

The effects of glass bead (GB) size and annealing temperature on the formation of β‐crystals of glass bead‐filled polypropylene (PP) are studied in this articles. Differential scanning calorimetry (DSC) measurements indicated that the amount of β‐form in PP crystals was a function of the glass bead content and size. For a fixed glass bead content, it was found that the smaller the diameter of the glass bead, the higher was the content of β‐crystals formed in the PP. On the other hand, wide‐angle X‐ray diffraction (WAXD) measurements revealed that the annealing temperature was also a major factor that affected the crystallization behavior of glass bead‐filled PP. It seemed that the blends with different glass bead contents had their own optimal annealing temperatures for β‐crystal formation. As an example, when the glass bead content was 48 wt %, the optimal annealing temperature for β‐crystal formation was about 108 °C, whereas it shifted to 100 °C for 14 wt % glass bead‐filled polypropylene. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 306–313, 2005
Pseudospin Hamiltonian parameters evaluated with regard to alkali metal ions in K3(H/D)(SO4)2 materials
Authors: Dolin S. P. , Levin A. A. , Mikhailova T. Yu. , Solin M. V. , Gavriluyk A. B. , Polyakov E. V.
Published: December 2004

An analysis of ferroelectric behavior of K3(H/D)(SO4)2 as members of the M3(H/D)(AO4)2 family is examined quantum chemically in the cluster approach using the structural models extended through the incorporation of K ions in an explicit form. We apply several structural models that describe the different types of (H/D)(SO4)2‐dimer surrounded by K ions, the geometry of the dimer being borrowed from the corrected diffraction data of the K3D(SO4)2 crystal in its ordered phase at the temperature below critical point Tc = 85 K. The calculations of the pseudospin Hamiltonian parameters—the Ising coupling parameters Jij and tunneling integrals Ω—were performed on the Hartree–Fock and second‐order Møller–Plesset perturbation theory levels with the 6‐31G–type basis sets. It is demonstrated that an effect of the K ions incorporation on the Jij values is minor (about several Kelvins). At the same time an influence of these ions on the double‐well potential characteristics (particularly, on the barrier heights) and thus on the tunneling integral value is more pronounced for both D‐ and H‐containing species. Despite the changes of the Hamiltonian parameters found, the major conclusion obtained earlier, referring to the suppression of the structural phase transition in H‐containing specimens due to proton quantum fluctuations, remains valid. The numerical estimations of the critical temperature Tc for completely deuterated materials that are obtained with and without regard to alkali metal ions are discussed. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Initial velocity distributions of ions generated by in‐flight laser desorption/ionization of individual polystyrene latex microparticles as studied by the delayed ion extraction method
Authors: Vera César Costa , Trimborn Achim , Hinz Klaus‐Peter , Spengler Bernhard
Published: December 2004

The delayed ion extraction method has been used to study characteristics of the initial velocity distributions of positive and negative ions produced simultaneously by laser desorption/ionization (LDI) from non‐impacted single aerosol polymeric particles, using a bipolar time‐of‐flight (TOF) instrument (LAMPAS 2). Due to the geometry of the setup and the characteristics of the ablation process, only the projections of the velocities on the axis of the mass spectrometer can be directly studied. Additionally, since the mean initial velocity under these conditions should be close to zero, it was necessary to extend the method by taking into account higher order contributions of the velocity distribution. Theoretical expressions for these higher order terms are presented and discussed. The bipolar characteristics of the instrument permit evaluation and treatment of a possible instrumental artifact caused by small inclinations of the ionizing laser with respect to the ideal incidence direction. Results of a number of experiments are presented and discussed in relation to the theoretical expressions presented, and to possible ablation scenarios. Evidence pointing out that, under our experimental conditions, only partial ablation of the latex particles occurs was obtained. The variance of the distribution of the projection of the initial velocities can be directly estimated from these results. By assuming that the total initial velocities of the ions are developed completely according to a single‐temperature adiabatic expansion mechanism, temperatures of approximately 50  K/Da can be assigned to the ion clouds from the variance estimations. If a two‐temperature model is used, a radial temperature of about 100 K/Da results. These values are in reasonable agreement with results for polymer ablation from the literature. Copyright © 2004 John Wiley & Sons, Ltd.
Fast gas‐phase hydrogen/deuterium exchange observed for a DNA G‐quadruplex
Authors: Gabelica Valérie , Rosu Frederic , Witt Matthias , Baykut Gökhan , De Pauw Edwin
Published: December 2004

The gas‐phase hydrogen/deuterium (H/D) exchange kinetics of DNA G‐quadruplexes has been investigated using Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). The quadruplex [(TGGGGT)4 · 3NH] undergoes very fast H/D exchange, in both the positive and in the negative ion modes, compared to DNA duplexes and other quadruplexes tested, and compared to the corresponding single‐stranded TGGGGT. Substitution of NH for K+ did not alter this fast H/D exchange, indicating that the hydrogens of the ammonium ions are not those exchanged. However, stripping of the interior cations of the quadruplex by source collision‐induced dissociation (CID) in the positive ion mode showed that the presence of the inner cations is essential for the fast exchange to be possible. Molecular dynamics simulations show that the G‐quadruplex is very rigid in the gas phase with NH ions inside the tetrads. We suggest that the fast H/D exchange is favored by this rigid quadruplex conformation. This example illustrates that the concept that compact DNA structures exchange H for D slower than unfolded ones is a misconception. Copyright © 2004 John Wiley & Sons, Ltd.
Changing aspects of psychiatric inpatient treatment
Authors: Rittmannsberger Hans , Sartorius Norman , Brad Mihaela , Burtea Victoria , Capraru Nora , Cernak Pavel , Dernovçek Mojca , Dobrin Ionescu , Frater Rosa , Hasto Jozef , Hategan Mieta , Haushofer Manfred , Kafka J. , Kasper Siegfried , Macrea Rodica , Nabelek Ludvik , Nawka Peter , Novotny Vladimir , Platz Thomas , Pojar Adela , Silberbauer Christoph , Fekete Sandor , Wancata Johannes , Windhager Elmar , Zapotoczky Hans-Georg , Zöchling Robert
Published: December 2004

This paper presents data obtained in a one-day census investigation in five European countries (Austria, Hungary, Romania, Slovakia, Slovenia). The census forms were filled in for 4191 psychiatric inpatients. Concerning legal status, 11.2% were hospitalised against their will (committed) and 21.4% were treated in a ward with locked doors. There was only a small correlation between commitment and treatment in a locked ward. More frequent than treatment of committed patients in locked wards was treatment of committed patients in open wards (Austria, Hungary) and treatment of voluntary patients in closed wards (Slovakia, Slovenia). Concerning employment, 27.7% of patients aged 18–60 held a job before admission. The vast majority of patients (84.8%) had a length of stay of less than 3 months. A comparison of these data with the results of a study performed in 1996 and using the same method shows a decrease of rates of long-stay patients. In 1996 the rates of employment were significantly higher in Romania (39.3%) and Slovakia (42.5%) compared to Austria (30.7%). These differences disappeared in 1999 due to decreasing rates of employment in Romania and Slovakia. The numbers of mental health personnel varies between types of institution (university or non-university) and countries, being highest in Austria and lowest in Romania. A considerable increase in the numbers of staff was found in Slovakia.
Is it worth while changing clinically stable schizophrenic out-patients with mild to moderate residual symptoms and/or side effects from conventional to atypical antipsychotics? A prospective, randomised study with olanzapine
Authors: Appelberg Björn , Tuisku Katinka , Joffe Grigori
Published: December 2004

Fifty clinically stable, schizophrenic outpatients, suffering from residual schizophrenic symptoms and/or neurological side effects, were randomised to either continue their conventional neuroleptic(s) or change it to olanzapine. After 12 weeks patients on olanzapine exhibited significant improvement in neurological side effects and psychotic symptomatology as compared to patients on conventional antipsychotics.
Patients’ satisfaction with hospitalization in a mixed psychiatric and somatic care unit
Authors: Eytan Ariel , Bovet Laurence , Gex-Fabry Marianne , Alberque Christel , Ferrero François
Published: December 2004

A patient satisfaction survey was undertaken in a mixed psychiatric and somatic care unit. An anonymous self-report questionnaire covering setting and satisfaction with care was completed by 60 patients. Median age was 42 (range 20–64), and the majority female (63%). Main ICD-10 diagnostic categories were depressive disorders (51.7%), substance-related disorders (33%) and personality disorders (25%). Somatic comorbidity was present in 60% of patients. Overall satisfaction with care and setting was high. Higher satisfaction was significantly associated with a history of previous hospitalizations in a psychiatric hospital and with being referred to the program by a psychiatrist. These findings emphasize the perceived advantages of mixed units, such as decreased stigmatization of psychiatric inpatients and opportunity to receive adequate treatment for both physical and mental problems during a single hospital stay.
PD98059 and U0126 activate AMP‐activated protein kinase by increasing the cellular AMP:ATP ratio and not via inhibition of the MAP kinase pathway
Authors: Dokladda Kanchana , Green Kevin A. , Pan David A. , Hardie D. Grahame
Published: December 2004

The MAP kinase pathway inhibitor U0126 caused phosphorylation and activation of AMP‐activated protein kinase (AMPK) and increased phosphorylation of its downstream target acetyl‐CoA carboxylase, in HEK293 cells. This effect only occurred in cells expressing the upstream kinase, LKB1. Of two other widely used MAP kinase pathway inhibitors not closely related in structure to U0126, PD98059 also activated AMPK but PD184352 did not. U0126 and PD98059, but not PD184352, also increased the cellular ADP:ATP and AMP:ATP ratios, accounting for their ability to activate AMPK. These results suggest the need for caution in interpreting experiments conducted using U0126 and PD98059.
Identification and characterisation of a novel splice variant of the human CB1 receptor
Authors: Ryberg Erik , Vu Huy Khang , Larsson Niklas , Groblewski Thierry , Hjorth Stephan , Elebring Thomas , Sjögren Sven , Greasley Peter J.
Published: December 2004

Cannabinoid ligands are implicated in many physiological processes and to date two receptors have been identified. However, a growing body of evidence exists that suggests the presence of additional receptors. Whilst cloning the previously described hCB1a, we have identified a novel variant that we call hCB1b. Characterising these two splice variants demonstrates that they have a unique pharmacological profile and that their RNA's are expressed at low levels in a variety of tissues.
Angiogenin and vascular endothelial growth factor in pregnancies complicated by preeclampsia
Authors: Shaarawy M. , Al‐Sokkary F. , Sheba M. , Wahba O. , Kandil H.O. , Abdel‐Mohsen I.
Published: December 2004

Objective

To investigate the role of the angiogenic factors, vascular endothelial growth factor (VEGF) and angiogenin in the pathophysiology of preeclampsia and how their concentrations correlate with the severity of the disease and fetal outcome.

Patients and Methods

A prospective study was carried out on 71 pregnant patients with preeclampsia and 20 pregnant normotensive controls. Maternal serum levels of VEGF and angiogenin were determined in all cases by enzyme immunoassay. Assessment of fetal well‐being using the Biophysical Profile Score (BPS), umbilical and uterine artery Doppler velocimetry, and infant birthweight were carried out.

Results

Maternal serum VEGF and angiogenin levels were significantly increased in cases of mild and severe preeclampsia compared to controls. Their increase was positively correlated with elevated systolic and diastolic blood pressure, as well as poor BPS, abnormal Doppler velocimetry, and low birthweight.

Conclusion

Elevated levels of both VEGF and angiogenin could confirm the existence of vascular reactivity and endothelial disturbance in preeclampsia. Measurement of these angiogenic factors in maternal serum may be a useful as biomarkers for the assessment of the severity of the disease and of fetal outcome.
An asymptotic solution for two‐phase flow in the presence of capillary forces
Authors: Vasco D. W.
Published: December 2004

Under the assumption of smoothly varying background properties I derive an asymptotic solution for two‐phase flow. This formulation partitions the modeling of two‐phase flow into two subproblems: an arrival time calculation and a saturation amplitude computation. The asymptotic solution itself is defined along a trajectory though the model. If gravitational forces are not important and the flow field is independent of changes in the background saturation, the trajectory may be identified with a streamline, and the asymptotic approach provides a mathematical basis for streamline simulation. The evolution of the saturation amplitude is governed by a generalization of Burgers' equation, defined along the trajectory. If the capillary properties are uniform and gravitational forces are negligible, one can derive self‐similar solutions for the three limiting behaviors of a two‐phase front. Asymptotic solutions were found to deviate by less than 5% from saturations calculated using a numerical simulator. The numerical results indicate that changes in capillary properties can introduce significant variations in the arrival time of a specific aqueous fraction. A more robust definition of arrival time appears to be the time associated with the peak rate of change in aqueous phase fraction, the greatest slope of the breakthrough curve.
Introduction to special section: Results of the Meteor 55: Tropical SOLAS Expedition
Authors: Wallace Douglas W. R. , Bange Hermann W.
Published: December 2004

This special section presents results from an interdisciplinary research cruise to the northern tropical Atlantic Ocean, which took place in October–November 2002. The cruise was planned as a pilot study for the international Surface Ocean – Lower Atmosphere Study (SOLAS) project. This introduction summarizes the goals as well as the hydrographic and atmospheric setting of the expedition. We also present a brief review of the findings published in this section and elsewhere concerning controls on trace gas fluxes and the biogeochemical significance of dust composition and deposition.
Testing loss mechanisms capable of rapidly depleting relativistic electron flux in the Earth's outer radiation belt
Authors: Green J. C. , Onsager T. G. , O'Brien T. P. , Baker D. N.
Published: December 2004

We investigate how relativistic electrons are lost from the Earth's magnetosphere in order to better understand the dynamic variability of the radiation belts. We identify 52 events where the >2 MeV electron flux at geostationary orbit decreases rapidly and use a superposed epoch analysis of multispacecraft data to characterize the accompanying solar wind and geomagnetic conditions and examine the relevance of potential loss mechanisms. The results show that the flux decrease events follow a common sequence. The electron flux is reduced first in the dusk sector concurrent with the stretching of the magnetic field to a more tail‐like configuration. The extreme stretching at dusk is caused by the formation of a partial ring current driven by changing solar wind conditions. We investigate three possible causes of the ensuing flux decrease: adiabatic electron motion in response to the changing magnetic field topology, drift out the magnetopause boundary, and precipitation into the atmosphere. The analysis reveals that the flux depletion is likely due to enhanced precipitation into the atmosphere, but the exact cause of the enhanced precipitation is still uncertain.
South Atlantic response to El Niño–Southern Oscillation induced climate variability in an ocean general circulation model
Authors: Colberg F. , Reason C. J. C. , Rodgers K.
Published: December 2004

The response of the South Atlantic Ocean to El Niño‐Southern Oscillation (ENSO) is investigated by means of an ocean general circulation model (ORCA2) forced with National Centers for Environmental Prediction (NCEP) reanalyses for the 1948–1999 period. Seasonal ENSO composites suggest that the ENSO‐induced wind anomalies play a major role in driving upper ocean temperatures by altering the net surface heat fluxes, the meridional Ekman heat transport, and Ekman pumping. Model diagnostics indicate that the Ekman heat transport changes are in better agreement with the upper ocean temperature anomalies during the first half of the ENSO event whereas, in the latter half, the surface heat flux anomalies agree better. In general, the atmospheric forcing tends to lead to a coherent ocean response with a time lag of about one season. Subsurface temperatures evolve more slowly in response to ENSO forcing than the upper ocean. They receive time‐filtered ENSO signals from mainly Ekman pumping (suction) and variations in thermocline depth that result in the poleward and equatorward margins of the subtropical gyre exhibiting temperature anomalies of the same sign but opposite to those in the central regions of the gyre.
Circulation and water masses beneath the northern Ronne Ice Shelf, Antarctica
Authors: Nicholls Keith W. , Makinson Keith , Østerhus Svein
Published: December 2004

We present oceanographic data from beneath the northern Ronne Ice Shelf. The data were collected during the austral summer of 2002–2003 from four sites located near the ice front in the Ronne Depression. They consist of conductivity‐temperature‐depth (CTD) profiles and time series from moored instruments that vary in length from 9 to 20 weeks. A strong, tidally modulated inflow of relatively fresh water was found at the eastern margin of the Ronne Depression. This low‐density inflow powers high basal melt rates that are responsible for a substantially thinned area of ice shelf. A northward flow of Ice Shelf Water along the western margin of the depression (the Antarctic Peninsula coast) was inferred from the CTD data. From the new CTD and current meter data, and from published results from cruises along the ice front, we suggest that the flows at the margins of the Ronne Depression establish east‐west density gradients that drive an anticyclonic circulation within the depression. The barotropic component of the circulation forms a gyre of strength 5 × 105 m3 s−1 and occupies a bowl in the field of water column thickness in the northern portion of the depression. All water masses sampled had temperatures below the surface freezing point and are therefore classified as Ice Shelf Water. The relatively complex nature of the oceanographic regime in the Ronne Depression is overlain by a seasonal variability that is hinted at by the available time series, probably explaining the apparent absence of inflowing HSSW at the time of the measurements.
Two‐dimensional steady unsaturated flow through embedded elliptical layers
Authors: Bakker Mark , Nieber John L.
Published: December 2004

New analytic element solutions are presented for unsaturated, two‐dimensional steady flow in vertical planes that include nonoverlapping impermeable elliptical layers and elliptical inhomogeneities. The hydraulic conductivity, which is represented by an exponential function of the pressure head, differs between the inside and outside of an elliptical inhomogeneity; both the saturated hydraulic conductivity and water retention parameters are allowed to differ between the inside and outside. The Richards equation is transformed, through the Kirchhoff transformation and a second standard transformation, into the modified Helmholtz equation. Analytic element solutions are obtained through separation of variables in elliptical coordinates. The resulting equations for the Kirchhoff potential consist of infinite sums of products of exponentials and modified Mathieu functions. In practical applications the series are truncated but still fulfill the differential equation exactly; boundary conditions are met approximately but up to machine accuracy, provided that enough terms are used. The pressure head, saturation, and flow may be computed analytically at any point in the vadose zone. Examples are given of the shadowing effect of an impermeable elliptical layer in a uniform flow field and funnel‐type flow between two elliptical inhomogeneities. The presented solutions may be applied to study transport processes in vadose zones containing many impermeable elliptical layers or elliptical inhomogeneities.