bluuebunny/crossref_metadata_2025_split huggingface dataset:
ATP‐induced apoptotic cell death in porcine ovarian theca cells through P2X7 receptor activation
Authors: Vázquez‐Cuevas Francisco G. , Juárez Bere , Garay Edith , Arellano Rogelio O. 
Published: March 2006

AbstractFolliculogenesis modulation via distinct neurotransmitters is a well‐documented phenomenon. Intraovarian purinergic signaling mechanisms have been identified previously in different species. However, the molecular elements involved and the physiological role of this purinergic signaling remain to be elucidated. Here, studies using RT‐PCR amplification, immunoblotting, and immunofluorescence microscopy showed that murine and porcine ovaries express the P2X7 subtype receptor, a cationic receptor‐channel operated by ATP. Using immunofluorescence it was demonstrated that P2X7 protein expression, in both mouse and pig, occurs specifically in the theca cells from antral follicles. Isolated porcine theca cells maintained in primary cultures and tested with 1 mM ATP or 250 µM Bz‐ATP, a specific agonist of P2X7, responded with an increase in intracellular calcium concentration, as demonstrated in cells loaded with fluo‐4 as calcium indicator. This strongly suggested that P2X7 receptors in theca cells are functional. Moreover, application for 24 hr of 1 mM ATP or 250 µM Bz‐ATP induced apoptotic cell death as indicated by the DNA fragmentation pattern, positive TUNEL test, and annexin V binding. This ATP effect was antagonized by 300 µM PPADS and 200 µM oxidized ATP. Also, addition of 5 mM EGTA in the external medium to chelate free Ca++decreased death cell to 24% of that produced by 200 µM Bz‐ATP, suggesting that Ca++influx participates in the phenomenon. The highly specific and functional expression of P2X7 receptors in theca cells suggest a role for ATP in modulating follicular physiology. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Confinement and clearance of OCT4 in the porcine embryo at stereomicroscopically defined stages around gastrulation
Authors: Vejlsted Morten , Offenberg Hanne , Thorup Flemming , Maddox‐Hyttel Poul 
Published: March 2006

AbstractIn the areas of developmental biology and embryonic stem cell research, reliable molecular markers of pluripotency and early lineage commitment are sparse in large animal species. In this study, we present morphological and immunohistochemical findings on the porcine embryo in the period around gastrulation, days 8–17 postinsemination, introducing a stereomicroscopical staging system in this species. In embryos at the expanding hatched blastocyst stage, OCT4 is confined to the inner cell mass. Following detachment of the hypoblast, and formation of the embryonic disk, this marker of pluripotency was selectively observed in the epiblast. A prominent crescent‐shaped thickening at the posterior region of the embryonic disk marked the first polarization within this structure reflecting incipient cell ingression. Following differentiation of the epiblast, clearance of OCT4 from the three germ layers was observed at defined stages, suggesting correlations to lineage specification. In the endoderm, clearance of OCT4 was apparent from early during its formation at the primitive streak stage. The endoderm harbored progenitors of the “fourth germ layer,” the primordial germ cells (PGCs), the only cells maintaining expression of OCT4 at the end of gastrulation. In the ectodermal and mesodermal cell lineages, OCT4 became undetectable at the neural groove and somite stage, respectively. As in the mouse, PGCs showed onset of c‐kit expression when located in extraembryonal compartments. They appeared to follow the endoderm during extraembryonal allocation and the mesoderm on return to the genital ridge. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Calpain 11 is unique to mouse spermatogenic cells
Authors: Ben‐Aharon Irit , Brown Paula R. , Shalgi Ruth , Eddy Edward M. 
Published: March 2006

AbstractThe calpains are a family of calcium‐dependent thiol proteases involved in intracellular processing of proteins. They occur as heterodimers containing one of various large subunits and a common small subunit. Some of the large subunits are expressed ubiquitously and others are expressed in a restricted set of tissues. We have cloned the cDNA for mouse calpain 11 and demonstrated that it is expressed specifically in the mouse testis. The mRNA begins to accumulate in the testis between days 14 and 16 after birth, corresponding to the period of pachytene spermatocyte development. The protein is detected by day 18 after birth, during mid to late pachytene spermatocyte development, and is present in the acrosomal region of spermatozoa from the cauda epididymis. The expression of calpain 11 during spermatogenesis and its localization in spermatozoa suggest that it is involved in regulating calcium‐dependent signal transduction events during meiosis and sperm functional processes. Mol. Reprod. Dev. Published 2006 Wiley‐Liss, Inc.
ProFit: two‐dimensional prior‐knowledge fitting of J‐resolved spectra
Authors: Schulte Rolf F. , Boesiger Peter 
Published: March 2006

AbstractA two‐dimensional fitting procedure is introduced, capable of extracting the full amount of information from 2D J‐resolved magnetic resonance spectroscopic data. The fitting procedure uses a linear combination of 2D model spectra. For reducing the degrees of freedom and increasing robustness, it is divided into a non‐linear outer loop and an inner linear least‐squares fit for the concentrations. In vitro and in vivo experiments on a whole‐body 3 T MR scanner show the detectability of a wide range of metabolites in the human brain, namely total creatine, N‐acetylaspartate, N‐acetylaspartylglutamate, choline‐containing compounds, glutamate, myo‐inositol, glutathione, scyllo‐inositol, γ‐aminobutyric acid, alanine and ascorbic acid. Copyright © 2006 John Wiley & Sons, Ltd.
Improved two‐dimensional J‐resolved spectroscopy
Authors: Schulte Rolf F. , Lange Thomas , Beck Johannes , Meier Dieter , Boesiger Peter 
Published: March 2006

AbstractLocalised two‐dimensional J‐resolved spectroscopy (JPRESS) is optimised for the in vivo detection of J‐coupled metabolites using magnetic resonance spectroscopy at 3 T. The acquisition of echo signals starts as early as possible (i.e. maximum‐echo sampling). This sampling scheme increases sensitivity and decreases overlap of peak tails, hence alleviating baseline problems. Reconstruction issues are discussed and the sensitivity is compared analytically with that of 1D PRESS. The qualitative behaviour of eddy currents in JPRESS is outlined and a 2D eddy current correction procedure based on the 1D phase deconvolution method is proposed. Copyright © 2006 John Wiley & Sons, Ltd.
Primary malignant peripheral nerve sheath tumor of the lung in a young child without neurofibromatosis type 1
Authors: Muwakkit Samar A. , Rodriguez‐Galindo Carlos , EL Samra Ahmad I. , Khoury Ruby , Akel Samir R. , Mroueh Salman , Razzouk Bassem , Abboud Miguel R. 
Published: March 2006

AbstractMalignant peripheral nerve sheath tumors (MPNST) are uncommon in children and almost half of the cases occur in patients with neurofibromatosis 1 (NF1). We report a child with a primary MPNST of the lung without NF1. MPNST of the lung has similar clinical and radiologic characteristics as pleuropulmonary blastoma. We suggest to include MPNST of the lung in the differential diagnosis of intrapulmonary masses in children. Pediatr Blood Cancer 2006; 47:636–638. © 2006 Wiley‐Liss, Inc.
Thyroid abnormalities in infantile hepatic hemangioendothelioma
Authors: Kalpatthi Ram , Germak John , Mizelle Katherine , Yeager Nicholas 
Published: March 2006

AbstractWe report an infant with hepatic hemangioendothelioma (HAE) associated with compensated hypothyroidism. The hepatic lesions regressed with steroid therapy and his thyroid function normalized with high doses of thyroxine supplement. Pediatr Blood Cancer 2007;49:1021–1024. © 2006 Wiley‐Liss, Inc.
Substructural cooperativity and parallel versus sequential events during protein unfolding
Authors: Reich Lothar , Weikl Thomas R. 
Published: March 2006

AbstractAccording to the “old view,” proteins fold along well‐defined sequential pathways, whereas the “new view” sees protein folding as a highly parallel stochastic process on funnel‐shaped energy landscapes. We have analyzed parallel and sequential processes on a large number of molecular dynamics unfolding trajectories of the protein CI2 at high temperatures. Using rigorous statistical measures, we quantify the degree of sequentiality on two structural levels. The unfolding process is highly parallel on the microstructural level of individual contacts. On a coarser, macrostructural level of contact clusters, characteristic parallel and sequential events emerge. These characteristic events can be understood from loop‐closure dependencies between the contact clusters. A correlation analysis of the unfolding times of the contacts reveals a high degree of substructural cooperativity within the contact clusters. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Transport properties of fullerene‐like WS2 nanoparticles
Authors: Kopnov F. , Yoffe A. , Leitus G. , Tenne R. 
Published: March 2006

AbstractElectrical resistivity and Hall effect measurements of pellets compacted from fullerene‐like WS2 nanoparticles (IF ‐WS2) and bulk 2H‐WS2 powder were carried out using the van der Pauw method over a wide temperature range. In addition IF ‐WS2 pellets were annealed at elevated temperatures under vacuum in a specially designed system. Arrhenius plots for the conductivities of the WS2 samples (2H, IF and IF +annealing) exhibit marked uprise of ∂ ln (sT –1)/∂T –1 with temperature. The resistivity of the non‐annealed IF ‐WS2 pellets is higher by 2–8 orders of magnitude than that of 2H‐WS2 pellets, whereas the resistivity of the annealed IF pellets is higher than that of the non‐annealed ones. Hall Effect measurements at 300 K show p‐type conductivity and similar carrier concentration for both types of materials. The carrier mobility of 2H‐WS2 platelets is found to be in the range of the reported values. However, IF ‐WS2 pellets have shown an unusually low mobility for a semiconducting material. The experimental data was found to be in a good agreement with a model used for analyzing the conductivity of polycrystalline semiconductors, which takes into consideration fluctuations of the barrier heights among the different nanoparticles as well as within a single nanoparticle boundary. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Numerical simulation of inhomogeneous and nonlinear diffusion
Authors: Sharma Anurag , Shishodia Manmohan Singh , Reddy G. B. 
Published: March 2006

AbstractA numerical technique, based on the collocation method, for solving the diffusion equation is presented. The method is applicable to general problem of diffusion including the cases where the diffusion properties are inhomogeneous and time dependent. It is also applicable to the problem of nonlinear diffusion where the diffusion coefficient is dependent on the concentration of the diffusants. Examples to show the applicability and computational efficiency of the method have also been included. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A study of the ferromagnetic behavior of Nd16Co76–xRuxB8 alloys
Authors: Paduani C. , Valcanover J. A. , Ardisson J. D. , Yoshida M. I. 
Published: March 2006

AbstractThe structural and magnetic properties of the tetragonal 2:14:1 hard magnetic phase (ϕ ) were investigated in Nd16Co76–x Rux B8 alloys. The results indicated that Ru substitution does not harm the formation of ϕ in Co‐rich alloys. An antiferromagnetic Co–Ru coupling is concluded. The cell volume initially decreases with the Ru substitution. The coercivity is enhanced and reaches a maximum at the composition where the saturation magnetization has the lowest value. The Curie temperature as well as the mean magnetic moment decrease with increasing Ru concentration. With the increase of the Ru concentration the unit‐cell volume increases. A ferrimagnetic ordering is predicted at higher Ru concentrations. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Some electronic and optical properties of self‐assembled quantum dots: asymmetries in a lens domain
Authors: Rodríguez A. H. , Meza‐Montes L. 
Published: March 2006

AbstractThe self‐assembled quantum dot with lens domain has rotational symmetry but it is intrinsically asymmetric when the electron moves perpendicularly to its circular base, i.e. along the rotational axis. To characterize this asymmetry, an external electric field is applied along either the positive or negative direction of the rotational axis. We report the different Stark shifts appearing in the spectra as a function of the field intensity for different lens domains. It is shown that for a flat lens domain the asymmetry effects decrease, but even for very flat lenses they can not be approximated by a cylindrical domain. Finally, some optical properties such as the dielectric constant and electroabsorption are studied. Signatures of the energy spectrum reveal in these quantities. The importance of considering the proper lens domain as long as the magnitude and direction field to tune a specific level transition is stressed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Acoustic phonon power spectra in a periodic superlattice
Authors: Mauriz P. W. , Vasconcelos M. S. , Albuquerque E. L. 
Published: March 2006

AbstractWe consider a Green function formalism, based on the frequency distribution, to study the propagation of acoustic phonon modes in a periodic superlattice. The calculations are based on the linear response function approach, which is very convenient to deal with this kind of problem. A damping term γ is included in a phenomenological way into the wavevector expression. In order to examine the phonon excitation, we also determine, by using the fluctuation‐dissipation theorem, their power spectra, which have many interesting properties. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoelectrical and noise processes in CdTe crystals
Authors: Virt I. S. , Bilyk I. S. , Popovych V. D. , Rudyj I. O. , Kurilo I. V. , Kolek A. , Bester M. , Kuzma M. 
Published: March 2006

AbstractTwo types of cadmium telluride single crystals were investigated: undoped CdTe grown by Bridgeman method and highly doped CdTe:Cl obtained by STHM. Photoconductivity properties of CdTe crystals were studied by the transient photoconductivity method. Persistent photo response due to the polarization effect was revealed in undoped samples. Noise spectra have been measured over a wide range of frequencies, from below 1 Hz up to 1 MHz, and for voltages applied the samples from 0 up to 200 V. Two type of noise dominates in the range of voltages and frequencies under investigation, namely excess 1/f noise and generation‐recombination (G‐R) noise. Two‐phase model were applied to explain noise experimental results, which consider the presence of precipitates. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Luminescent properties of ZnS:Ce,Y phosphor
Authors: Okamoto Shinji , Tanaka Katsu 
Published: March 2006

AbstractThe ZnS:Ce phosphor together with a co‐activator Y3+ ion shows a bright saturated blue luminescence whose spectrum is a band with a peak wavelength of 450 nm. The chromaticity coordinates are x = 0.15 and y = 0.09, and thus this phosphor would be good for the blue primary color in displays and light sources. The blue luminescence is due to the 5d‐4f internal transition of the Ce3+ ion. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exciton‐donor complexes in a semiconductor quantum dot in a magnetic field
Authors: Djotyan A. P. , Avetisyan A. A. , Kazaryan E. M. , Moulopoulos K. 
Published: March 2006

AbstractThe binding energy of the ground state of a charged exciton‐donor complex in a spherical semiconductor quantum dot in the presence of a homogeneous magnetic field has been calculated. The theoretical analysis is carried out using a variational approach in the framework of the adiabatic approximation. The behavior of the binding energy of the complex in a QD on magnetic field is investigated for different values of the QD radius. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of annealing on the structural and magnetic properties of epitaxial Zn1–xMnxO films grown by MOCVD on sapphire
Authors: Chikoidze E. , von Bardeleben H. J. , Dumont Y. , Jomard F. , Gorochov O. 
Published: March 2006

AbstractThermal annealing of MOCVD grown Zn1–xMnxO layers between 300 °C and 1000 °C in an oxygen atmosphere modifies both their latttice parameters and their magnetic properties. Combined X‐ray diffraction and EPR studies indicate a redistribution of intrinsic defects but persistent antiferromagnetic phase in the annealed films. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evaluation of crystal structure and photoluminescence for ZnTe epilayers grown on a 2o off‐oriented GaAs (100) substrate
Authors: Yu Young‐Moon , Yoon M.‐Y. , Choi Yong Dae 
Published: March 2006

AbstractHigh quality zincblende ZnTe epitaxial layers have been grown on a tilted GaAs (100) substrate by hot‐wall epitaxy. The surface morphology and the crystallinity were investigated in terms of their growth temperature dependence while the optical properties were analyzed by photoluminescence spectroscopy (PL). It was found that the orientation of the epitaxial layer was inclined to the substrate crystal plane. The optimum growth condition was found to be a growth temperature of 470 °C. The ground state and excited states of free exciton emissions were clearly observed at 10 K PL. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of GaN buffer layers on the polarity and properties of ZnO epilayers on nitrided c‐Al2O3 by MBE
Authors: Roh O. H. , Wang X. , Che S. B. , Ishitani Y. , Yoshikawa A. 
Published: March 2006

AbstractZnO epilayers were grown on nitrided c‐Al2O3 substrates by MBE and the effect of the deposition temperature for GaN buffer layers on the polarity of ZnO epilayer and their properties such as structural and optical properties were investigated. Zn‐polar ZnO was normally obtained by using the low temperature GaN buffer layer at 650 °C, while O‐polar ZnO were obtained by the high‐temperature GaN buffer layer at 850 °C. PL spectra for Zn‐polar and O‐polar ZnO epilayers, PL spectra were dominated by donor‐bound exciton at 3.361 eV and acceptor‐bound exciton at 3.356 eV, respectively. It was found that the position of emission peak was affected by the strain in the ZnO layer. PL spectra observed in ZnO epilayers with different polarities are discussed together with their reflectance spectra and strains of ZnO epilayers with different polarities. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of the ex‐situ and in‐situ annealed self‐buffer layer on ZnO film
Authors: Wang Jinzhong , Sallet Vincent , Amiri Gaëlle , Rommelluere Jean‐François , Lusson Alain , Rzepka E. , Lewis John E. , Galtier Pierre , Fortunato Elvira , Martins Rodrigo , Gorochov Ouri 
Published: March 2006

AbstractTwo self‐buffer layers were grown on c‐plane sapphire substrates by atmospheric MOCVD method using DEZn, tert‐butanol as precursors and H2 as carrier gas. Then, they were respectively annealed in growth process and oxygen environment. After that, ZnO films were respectively grown on them. XRD spectra show that all the films were grown in [002] orientation. Furthermore, the film with a buffer layer annealed in oxygen exhibits much higher crystal quality. Its FWHM of the rocking curve is only 567 arcsec. Furthermore, its Raman scattering spectrum appears a much stronger E2 mode peak at 436 cm–1 and its PL spectrum appears a shoulder at 3.367 eV on the higher energy side. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oligomerization process in MOVPE growth of ZnO
Authors: Maejima K. , Fujita S. 
Published: March 2006

AbstractChemical reactions in the vapor phase during metalorganic vapor phase epitaxy growth of ZnO are investigated with in‐situ monitoring using Fourier transform infrared spectroscopy. Diethylzin (DEZn) and nitrous oxide (N2O) were used for zinc and oxygen source, respectively. DEZn reacts first with oxygen atom generated from N2O dissociation, and changes to diethoxy zinc (DEOZn; Zn(OC2H5)2). Then C2H4 is eliminated from DEOZn at high temperature, and DEOZn changes to zinc dihydroxide (Zn(OH)2). In addition to these reactions, oligomerization of the reactants occurs, that is, they make their dimers, trimers, tetramers and higher‐order oligomers, and they contribute to the formation of ZnO on the substrates. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetoresistance of n‐type ZnO:Al and Zn1–xMnxO:Al thin films
Authors: Andrearczyk T. , Jaroszyński J. , Grabecki G. , Dietl T. , Fukumura T. , Kawasaki M. 
Published: March 2006

AbstractThe role of spin‐orbit and s‐d exchange interactions is investigated by magnetoresistance (MR) measurements carried out down to 50 mK on ZnO and Zn1–x Mnx O with x = 3 and 7% and electron concentration ∼1020 cm–3. The data for ZnO:Al leads to the coupling constant λ so = (4.4 ± 0.4) × 10–11 eV cm of the kp hamiltonian for the wurzite structure, H so = λ soc(s × k). Complex MR of Zn1–x Mnx O:Al is interpreted in terms of the influence of the s‐d spin‐splitting on the disorder‐modified electron‐electron interactions and precursor effects of magnetism‐related localization. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigations of p‐type signal for ZnO thin films grown on (100) GaAs substrates by pulsed laser deposition
Authors: Rogers D. J. , Teherani F. Hosseini , Monteiro T. , Soares M. , Neves A. , Carmo M. , Pereira S. , Correia M. R. , Lusson A. , Alves E. , Barradas N. P. , Morrod J. K. , Prior K. A. , Kung P. , Yasan A. , Razeghi M. 
Published: March 2006

AbstractIn this work we investigated ZnO films grown on semi‐insulating (100) GaAs substrates by pulsed laser deposition. Samples were studied using techniques including X‐ray diffraction (XRD), scanning electron microscopy, atomic force microscopy, Raman spectroscopy, temperature dependent photoluminescence, C‐V profiling and temperature dependent Hall measurements. The Hall measurements showed a clear p‐type response with a relatively high mobility (∼260 cm2/V s) and a carrier concentration of ∼1.8 × 1019 cm–3. C‐V profiling confirmed a p‐type response. XRD and Raman spectroscopy indicated the presence of (0002) oriented wurtzite ZnO plus secondary phase(s) including (101) oriented Zn2As2O7. The results suggest that significant atomic mixing was occurring at the film/substrate interface for films grown at substrate temperatures of 450 ºC (without post‐annealing). (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Catalyst‐free vapor‐phase transport growth of vertically aligned ZnO nanorods on 6H‐SiC and (11‐20)Al2O3
Authors: Mofor A. C. , Bakin A. S. , Elshaer A. , Fuhrmann D. , Bertram F. , Hangleiter A. , Christen J. , Waag A. 
Published: March 2006

AbstractZnO nanostructures are expected to pave the way for many interesting applications in optoelectronics, spin electronics gas sensor technology and biomedicine. Fabrication methods, especially for nanorods have been based mostly on catalyst‐assisted growth methods that employ metal‐organic sources and other contaminating agents like graphite to grow ZnO nanorods at relatively high temperatures. We report on the growth of ZnO nanorods on 6H‐SiC and (11‐20)Al2O3 using purely elemental sources, without catalysis and at relatively low temperatures and growth pressure in a specially designed vapor‐phase transport system. ZnO nanorods with widths of 80‐900 nm and lengths of 4–12 µm were obtained. Nanorod concentrations of up to 109 cm–2 with homogenous luminescence and high purity were noted. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)