bluuebunny/crossref_metadata_2025_split huggingface dataset:
Airway hyperreactivity detected by methacholine challenge in children with sickle cell disease
Authors: Ozbek Ozlem Yilmaz , Malbora Baris , Sen Nazan , Yazici Ayse Canan , Ozyurek Emel , Ozbek Namik 
Published: October 2007

AbstractRecent studies have emphasized the presence of airway hyperreactivity (AHR) in children with sickle cell disease (SCD). However, various tests for the detection of AHR have yielded distinctly different results in these patients. This study identified AHR via a methacholine challenge test (MCT) in a group of children with SCD (31 patients; age range, 6–16 years). The results of pulmonary function tests (PFTs) in patients with SCD and age‐matched controls (30 healthy children) were investigated and compared. A positive methacholine challenge result was noted in 25 patients (77.5%). We found that when compared with controls, the children with SCD had lower forced vital capacity (FVC) and forced expiratory volume in 1 sec (FEV1) and that both their forced expiratory flow at 25–75% of the FVC (FEF25–75) and their FEV1/FVC ratio were not statistically significantly different from those of the controls. The statistically significant differences remained after treatment with a bronchodilator agent, but the changes in the FVC, FEV1, and FEF25–75 in response to bronchodilator treatment did not differ with statistical significance between the two groups. There was a negative correlation between the number of ACS attacks and the percent predicted of the FEV1 and the FEV1/FVC ratio. We found that the MCT reveals a high incidence of AHR in patients with SCD, regardless of whether those individuals have ACS. Pediatr Pulmonol. 2007; 42:1187–1192. © 2007 Wiley‐Liss, Inc.
Nickel catalysed sixfold ring clustering and graphitisation in C:Ni nanocomposites: A Raman analysis
Authors: Krause M. , Abrasonis G. , Kolitsch A. , Mücklich A. , Kreissig U. , Möller W. 
Published: October 2007

AbstractThe structural phases of C:Ni nanocomposite thin films prepared by ion beam co‐sputtering at temperatures 25 °C ≤ θS ≤ 500 °C were characterized by NIR Raman spectroscopy. Ni was found to catalyse sixfold ring clustering and graphitisation of carbon in C:Ni nanocomposites. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the theory of nucleation in cylindrical magnetic nanoparticles
Authors: Laroze D. , Baranov S. A. , Vargas P. , Vazquez M. 
Published: October 2007

AbstractThe phenomenon of nucleation in a single magnetic cylinder of nanometer size is considered; in particular we investigate the influence of the surface anisotropy energy. We find analytical solutions with soliton characteristics. As a function of the surface anisotropy strength, the magnetic energy exhibits a transition. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Cutting tool performance enhancement by using a B4C/BCN/C‐BN multilayer system
Authors: Bejarano Gaitan G. , Caicedo J. C. , Prieto P. , Balogh Adam G. 
Published: October 2007

AbstractThin films of B4C/BCN/c‐BN multilayers were deposited on to AISI M2 high speed steel substrates by r. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron ground state in concentric GaAs‐(Ga,Al)As single and double quantum rings
Authors: Culchac Francisco Javier , Granada Juan Carlos , Porras‐Montenegro N. 
Published: October 2007

AbstractWe study the effect of geometric confinement on the electron states in a concentric double quantum ring. We calculate the energy of the electron ground state for both symmetric and asymmetric double quantum rings as a function of the radius of the inner and outer rings, the barrier height and as a function of an applied magnetic field. We found that the probability amplitude for the electron state is approximately the same in the inner and outer wells of the structure when the width of the wells is the same, but there is a noticeable change in the probability amplitude in the well regions when the width of the inner well is slightly different from the outer one (asymmetric rings). As a result the carrier energy changes considerably from one situation to the other. On the other hand the barrier width between the inner and outer ring plays an important role in the definition of the energy of the electron ground state up to the extent that for certain values of the barrier and well widths, the energy of the ground state does not depend any more on the barrier width. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of Sm3+ ions and influence of odd third‐order intensity parameters in fluoride glasses
Authors: Flórez A. , Herrera A. , Florez M. 
Published: October 2007

AbstractFluoride glasses in the following compositions (39‐x)InF3‐20ZnF2‐20SrF2‐16BaF2‐2GdF3‐2NaF‐1GaF3‐xTRF3, with x = 1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 mol%: and TR = Sm were prepared in a dry box. Absorption spectra at room temperature are obtained in the spectral range from 340 to 2700 nm. From the area under the absorption band we obtained the experimental oscillator strengths, fExp.. By using the Judd‐Ofelt theory and a least‐square fit process, we obtained the phenomenological intensity parameters, Ωλ (λ = 2, 4, 6), and calculated the theoretical oscillator strengths, fCal. In order to evaluate the influence of the odd third‐order intensity parameter over oscillator strengths, we used the modified Judd‐Ofelt model. The better set (the set with smaller r.m.s.) is used to analyze the influence of third‐order effects through odd intensity parameters in the modified model. The results obtained with the standard and modified model are analyzed. In order to evaluate potential applications of Sm3+ ions in these glasses, the better set is used to calculate the following spectroscopy parameters: radiative lifetime, τr, transition probability between multiplets, AJJ’︁, peak cross section to stimulate emission, ρp and branching ratio, βJJ' are calculated. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Application of a phenomenological model for the surface impedance in high temperature superconducting films
Authors: Mosquera A. S. , Landínez Téllez D. A. , Roa‐Rojas J. 
Published: October 2007

AbstractWe report the application of a phenomenological model for the microwave surface impedance in high temperature superconducting films. This model is based on the modified two‐fluid model, in which the real and imaginary parts of the surface impedance use the modelling parameter γ. This is responsible for the superconducting and normal charge carrier density and is used for the description of the temperature dependence of the London penetration depth λL(T) including λL(0). The relaxation time model also uses the γ parameter in combination with the residual resistance parameter α. The parameter δ1<< 1 provides a finite value of the relaxation time at T = 0. The normal conductivity is described by the metals conduction model and the phenomenological description of the normal conductivity contains four parameters: δ1, γ, α, and δ2. The parameter δ2<< 1 is responsible for the non‐pairing part of the charge carrier at T = 0. Temperature dependence of σn(T) is a result of the competition between the increase of the relaxation time and the decrease of the normal charge‐carrier density. We applied this model to analyze experimental results of MgB2, YBa2Cu3O7‐δand GdBa2Cu3O7‐δsuperconducting material. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Conductivity fluctuation in the high temperature superconductor with planar weight disparity Y0.5Sm0.5Ba2Cu3O7−δ
Authors: Barrera E. W. , Rojas Sarmiento M. P. , Rincón L. F. , Landínez Téllez D. A. , Roa‐Rojas J. 
Published: October 2007

AbstractThe synthesis of the Y0.5Sm0.5Ba2Cu3O7–δ superconducting material by the standard solid state reaction is reported. DC resistivity measurements reveal the improvement of the critical temperature (Tc) when substitution of exact 50‐50 mix of Yttrium and Samarium is performed. A bulk Tc = 101 K was determined by the criterion of the maximum in the temperature derivative of electrical resistivity. Structure characterization by means the x‐ray diffraction technique shows the crystalline appropriated distribution of Yttrium and Samarium to create substantial planar weight disparity (PWD) in alternating layers. This PWD increases Tc in copper‐oxide superconductors. In order to examine the effect of PWD on the pairing mechanism close to Tc, conductivity fluctuation analysis was performed by the method of logarithmic temperature derivative of the conductivity excess. We found the occurrence of Gaussian and genuinely critical fluctuations. Our results are in agreement with reports on YBa2Cu3O7–δ, but an enhancement of the Gaussian fluctuation regimes was experimentally detected as a result of the PWD. The correlations of the critical exponents with the dimensionality of the fluctuation system for each Gaussian regime were performed by using the Aslamazov‐Larkin theory. The genuinely critical exponent is interpreted by the 3D‐XY model as corresponding with the dynamical universality class of the E‐model. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Co‐doping effect of Fe2O3 on the ionic transport of Na2SO4
Authors: Torijano E. , Vargas R. A. , Mellander B.‐E. 
Published: October 2007

AbstractThermal and transport properties of Na2SO4‐Fe2O3 composites, with molar composition in the range x = 0.1‐0.5, were studied by using impedance spectroscopy and thermal analysis. The electrical conductivity of this solid solution increases rapidly with increasing Fe2O3 content, from a value at about 0.05 × 10–4 S/cm (for x = 0.0) up to 0.22 × 10–4 S/cm for x = 0.1. The largest enhancement in the conductivity is observed for 10, 20 and 40 mol% Fe2O3 compositions, a feature not commonly encountered in known composite systems. The step change in the conductivity of pure sodium sulphate at 241 °C, associated with a first order phase transition, that not only shifts slightly to a higher temperatures when the Fe2O3 content increases, but it is also observed a reduction of the step hight. The results are discussed considering an approximation effect of the nanoparticles on the Na+ transport in the Na2SO4 compound. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Pure spin‐currents
Authors: Hoffmann Axel 
Published: October 2007

AbstractThe new development of spintronics aims at utilizing the spin degree of freedom for electronic applications. To this date, in most investigated spintronics systems and devices the spin and charge currents are in parallel and therefore directly coupled. However, using non‐local lateral devices allows to separate spin and charge currents, which allows the investigation of pure spin‐currents. This article reviews the recent developments using non‐local spin‐dependent measurements and other approaches towards utilizing pure spin‐currents. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the improvement of the electroluminescent signal of organic light emitting diodes by the presence of an ultra‐thin metal layer at the interface organic/ITO
Authors: Bernède J. C. , Martinez F. , Neculqueo G. , Cattin L. 
Published: October 2007

AbstractThe electroluminescent (EL) signal of organic light emitting diodes (OLEDs) based on simple “hole transporting layer/electron transporting layer” (HTL/ETL) structures has been studied as a function of the anode/HTL interface, the anode being an indium tin oxide (ITO) film. It is shown that the electroluminescent (EL) signal increases when a metal ultra‐thin layer is introduced between the anode and the HTL. Experimental results show that the work function value of the metal is only one of the factors which allow improving the EL signal via better hole injection efficiency. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Subacute H2O2, but not poly(IC), upregulates dopamine D2 receptors in retinoic acid differentiated SH‐SY5Y neuroblastoma
Authors: Larouche Annie , Berube Patrick , Sarret Philippe , Grignon Sylvain 
Published: October 2007

AbstractAbnormalities of striatal dopaminergic neurotransmission play a significant role in the pathophysiology of central nervous system disorders such as movement disorders, addictions and schizophrenia. The striatum appears to be exposed to intrinsically high levels of oxidative stress (OS). Little is known, however, on the effect of OS on the regulation of the dopamine D2 receptor (DRD2), a key component of striatal dopaminergic neurotransmission. We report here on the effects of H2O2 (a canonical oxidant and non conventional messenger) and polyinosinic‐polycytidylic acid (poly(IC) which elicits schizophrenia‐like behaviors in newborn rodents and disrupts dopaminergic system development), on DRD2 levels in retinoic acid differentiated SH‐SY5Y neuroblastoma. H2O2 elicited a significant increase in DRD2 mRNA and protein levels. Conversely, poly(IC) did not regulate DRD2 levels, although SH‐SY5Y cells were confirmed to express TLR3 receptors. Under our conditions, H2O2, but not poly(IC), increased NFκB activation (as assessed by p65 nuclear translocation), which paralleled their effects on DRD2 levels regulation. Synapse 62:70–73, 2008. © 2007 Wiley‐Liss, Inc.
Differential distribution of PDE4B splice variant mRNAs in rat brain and the effects of systemic administration of LPS in their expression
Authors: Reyes‐Irisarri Elisabet , Pérez‐Torres Silvia , Miró Xavier , Martínez Emili , Puigdomènech Pere , Palacios José M. , Mengod Guadalupe 
Published: October 2007

AbstractPhosphodiesterases (PDE) control intracellular cyclic adenosine monophosphate (cAMP) levels, which appear to play an important role in the regulation of inflammation. PDE4B is especially important in this process. Using in situ hybridization histochemistry we first mapped the expression sites of the four PDE4B splicing forms in rat brain. Using the systemic administration of the bacterial endotoxin lipopolysaccharide (LPS) as an inflammation model in rats, we found an increase in PDEB2 mRNA expression in choroid plexus. The differential expression of PDE4B spliced forms and the differential regulation of PDE4B2 in an inflammatory model further supports an involvement of this splicing variant in the inflammatory response. Synapse 62:74–79, 2008. © 2007 Wiley‐Liss, Inc.
Comparison of cartridge case and airborne GSR—a study of the elemental composition and morphology by means of SEM‐EDX
Authors: Brożek‐Mucha Zuzanna 
Published: October 2007

AbstractA comparative study of the properties of gunshot residue (GSR) collected from shooter's hands and from inside the case of the same cartridge used in a shooting experiment was performed. Three types of popular Luger 9 mm ammunition were chosen with primer mixtures based on different types of detonators: mercury fulminate, lead styphnate or lead azide and an organic one, e.g. diazodinitrophenol. Two modifications of lead‐free ammunition, with copper and tin plated projectiles were used. Samples of GSR were examined by means of scanning electron microscopy and energy dispersiveX‐ray spectrometry. Both, similarities and differences in the chemical composition and morphology of GSR secured from the hands of the shooting person and from the appropriate cartridge case were observed. The chemical composition of the characteristic gunshot particles originating from the primer may be influenced by the chemical composition of other parts of the cartridge case, especially the core and the jacket of the projectile. Thus, the distribution of the chemical elements in GSR strongly depends on the direction of the reaction path starting in the primer cup placed at the bottom of the cartridge case, moving along the cartridge case and finishing when the projectile leaves the gun muzzle. A reliable comparison of the airborne residue to these taken from cartridge case for forensic purposes requires some experience based on laboratory experiments performed under controlled conditions. Copyright © 2007 John Wiley & Sons, Ltd.
Culture and Acculturation Influences on Palestinian Perceptions of Prenatal Genetic Counseling
Authors: Awwad Rawan , Veach Patricia McCarthy , Bartels Dianne M. , LeRoy Bonnie S. 
Published: October 2007

AbstractPatient cultural backgrounds strongly influence decision‐making processes and outcomes in genetic counseling. The present study investigated influences of culture and acculturation on prenatal decision making processes of native Palestinians and Palestinian Americans. Seventeen native Palestinians and 14 first‐generation, Palestinian Americans were interviewed and asked to imagine themselves as patients in hypothetical premarital and prenatal situations. Five major issues were investigated: 1) Influence of family history of an inherited condition on pre‐marital decisions; 2) Perceptions of non‐directive genetic counselor statements regarding options; 3) Role of gender in prenatal decisions; 4) Gender differences in emotional expression; and 5) Role of family and society in prenatal decisions. Several similarities and differences in native Palestinian and Palestinian American responses were obtained. Similarities appear to be due to common cultural roots, while differences may be due to acculturation. Practice and research recommendations are provided.
Tobacco smoke‐induced left ventricular remodelling is not associated with metalloproteinase‐2 or ‐9 activation
Authors: Castardeli Edson , Duarte Daniella R. , Minicucci Marcos F. , Azevedo Paula S. , Matsubara Beatriz B. , Matsubara Luiz S. , Campana Álvaro O. , Paiva Sergio A.R. , Zornoff Leonardo A.M. 
Published: October 2007

AbstractAimTo investigate the role of MMP‐2 and MMP‐9 in cardiac remodelling induced by tobacco smoke exposure in rats.MethodsRats were allocated into two groups: C (n=9): control animals; ETS (n=9): exposed to tobacco smoke. After 4months, the animals underwent echocardiography, morphometric study and determination of MMP‐2 and MMP‐9 activity.ResultsETS rats had larger diastolic (C=15.6 ±1.2mm/kg, ETS=18.0±0.9mm/kg; p < 0.001) and systolic (C=7.3±1.2mm/kg, ETS=9.2±0.9mm/kg; p=0.001) ventricular diameters adjusted for body weight. Fractional shortening (C53–4.8%, ETS+48±3.3%; p=0.031) and ejection fraction (C=0.89±0.03, ETS=0.86±0.02; p=0.030) were smaller in the ETS group. Myocyte cross‐sectional area (C=245±8μm2, ETS=253±8μm2; p=0.028) was higher in ETS rats. There were no differences in MMP‐2 (C=50±14%; ETS=43±11%, p=0.228) or MMP‐9 (C=0.36±0.3%; ETS=0.62±0.3%, p=0.630) activity between the groups.ConclusionMMP‐2 and MMP‐9 did not participate in the remodelling process induced by tobacco smoke exposure.
Nonlinear dynamics of the filamentation of the resistive instability of a current-carrying plasma
Authors: NIKNAM A. R. , SHOKRI B. 
Published: October 2007

AbstractThe filamentation of the resistive instability in a weakly ionized quasi-neutral current-carrying plasma in the diffusion frequency region in the nonlinear regime is investigated. By using the magnetohydrodynamics equations and Ampere's law and assuming that the plasma is non-isothermal and inhomogeneous, the evolution of the magnetic field diffusion into the plasma is described by the Lienard nonlinear differential equation. Furthermore, it is shown that the departure of the profiles of the magnetic field and electron density variation from a sinusoidal shape in the nonlinear regime and a transverse filamentation and density steepening can occur in the static limit. Also, it is shown that the shape of the transverse filamentation can vary in this regime depending on the gradient of the magnetic field.
New approaches to pathogenesis of malaria in pregnancy
Authors: ROGERSON S. J. , BOEUF P. 
Published: October 2007

SUMMARYMalaria infection during pregnancy is associated with poor maternal and foetal outcomes including low birth weight. In malaria-endemic areas, low birth weight is primarily a consequence of foetal growth restriction. Little is known on the pathogenesis of foetal growth restriction and our understanding of the relationship between epidemiological observations and the pathogenesis or consequences of disease is incomplete. In this review, we describe these gaps in our knowledge and also try to identify goals for future research into malaria in pregnancy. Foetal growth restriction results from a complex four-dimensional interaction between the foetus, the mother and the malaria parasite over gestation, and research into its pathogenesis may be advanced by combining longitudinal studies with techniques and approaches new to the field of malaria in pregnancy. Such approaches would greatly increase our knowledge on the pathogenesis of this disease and may provide new avenues for intervention strategies.
VAR2CSA and protective immunity against pregnancy-associatedPlasmodium falciparummalaria
Authors: HVIID L. , SALANTI A. 
Published: October 2007

SUMMARYPeople living in areas with stable transmission ofP. falciparumparasites acquire protective immunity to malaria over a number of years and following multiple disease episodes. Immunity acquired this way is mediated by IgG with specificity for parasite-encoded, clonally variant surface antigens (VSA) on the surface of infected erythrocytes (IEs). However, women in endemic areas become susceptible toP. falciparuminfection when they become pregnant, particularly for the first time, regardless of previously acquired protective immunity. This conundrum was resolved when it was observed that the selective placental accumulation of IEs that characterizes pregnancy-associated malaria (PAM) is caused by an immunologically and functionally unique subset of VSA (VSAPAM) that is only expressed by parasites infecting pregnant women, and that protective immunity to PAM is mediated by IgG with specificity for VSAPAM. In this review we summarize the research leading to the identification of the distinctly structured PfEMP1 variant VAR2CSA as the dominant PAM-type VSA and as the clinically most important target of the protective immune response to placentalP. falciparuminfection.
The host-parasite relationship in pregnant cattle infected withNeospora caninum
Authors: INNES ELISABETH A. 
Published: October 2007

SUMMARYThe protozoan parasiteNeospora caninumis an important cause of reproductive disease in cattle worldwide. The dog is a definitive host for the parasite and the oocyst stage, shed in the faeces, is a source of infection for cattle through consumption of contaminated feed or water. In addition, transplacental transmission ofN. caninumis a very efficient means of the parasite infecting a new host and this can occur in successive pregnancies and over several generations.Neosporaparasites may cause disease during pregnancy resulting in death of the foetus or birth of live congenitally infected calves that may show some neurological clinical signs at birth. The stage of pregnancy at which infection/parasitaemia occurs is an important factor in determining disease severity.Neosporainfection in the first trimester of pregnancy may have more severe consequences for the foetus compared with infection occurring in the final trimester. The host-parasite relationship during pregnancy is a fascinating interaction and research in this area will improve understanding of disease pathogenesis and the various consequences of the host immune response, being host-protective, parasite protective and contributing to disease pathology. Pregnancy poses an interesting problem for the immune system of the dam as she is essentially carrying a semi-allogeneic tissue graft (the foetus) without immunological rejection taking place. To facilitate the pregnancy the cytokine environment in the placenta favours the regulatory Th-2-type cytokines, whose role is to counteract the pro-inflammatory Th1-type immune responses. Protective immunity toN. caninum, similar to many other intracellular parasites, involves Th1-type immune responses, which may pose problems for the dam trying to control aNeosporainfection during pregnancy.This paper will discuss the host-parasite relationship at different stages of gestation in pregnant cattle and review the implications of this research for our understanding of disease pathogenesis, parasite transmission and host protection.