bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dermal fibroblasts cultured on small intestinal submucosa: Conditions for the formation of a neotissue
Authors: Cimini Massimo , Boughner Derek R. , Ronald John A. , Johnston Danielle E. , Rogers Kem A. 
Published: August 2005

AbstractSmall intestinal submucosa (SIS) is a naturally occurring, acellular biomaterial that has been used extensively as a soft tissue replacement, as a scaffold for tissue engineering, and as a substrate for the study of cells in 3D culture. The aim of this study is to define culture parameters that promote neotissue formation with the use of dermal fibroblasts and SIS. SIS sheets were seeded with dermal fibroblasts and cultured for 4 weeks. The resultant cell‐scaffold composites (CSCs) were cultured with media alone, media supplemented with ascorbic acid, or fibronectin‐pretreated SIS and ascorbic acid. CSCs were analyzed for cellular invasion into the scaffold, the rate of type I collagen production, MMP gelatinolytic activity, thickness, and ultrastructural morphology. CSCs treated with fibronectin and ascorbate showed an increase in Type I collagen production, no change in the MMP gelatinolytic activity, an increase in CSC thickness, and an organized neotissue on the surface of the SIS. Minimal cellular invasion was noted, suggesting that fibroblasts use the SIS as a template for neotissue growth rather than as a scaffold. These results indicate that fibronectin‐treated SIS cultured with dermal fibroblasts in the presence of ascorbic acid will promote true neotissue formation for future cardiovascular tissue engineering efforts. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Three‐dimensional fiber‐deposited PEOT/PBT copolymer scaffolds for tissue engineering: Influence of porosity, molecular network mesh size, and swelling in aqueous media on dynamic mechanical properties
Authors: Moroni L. , de Wijn J. R. , van Blitterswijk C. A. 
Published: August 2005

AbstractAmong novel scaffold fabrication techniques, 3D fiber deposition (3DF) has recently emerged as a means to fabricate well‐defined and custom‐made scaffolds for tissue regeneration, with 100% interconnected pores. The mechanical behavior of these constructs is dependent not only on different three‐dimensional architectural and geometric features, but also on the intrinsic chemical properties of the material used. These affect the mechanics of the solid material and eventually of 3D porous constructs derived from them. For instance, poly(ethylene oxide terephthalate)‐poly(butylene terephthalate) (PEOT/PBT) block copolymers are known to have mechanical properties, depending on the PEOT/PBT weight ratio in block form and on the molecular weight of the initial poly(ethylene glycol) (PEG) blocks. These differences are enhanced even more by their different swelling properties in aqueous media. Therefore, this article examines the influence of copolymer compositions in terms of their swelling on dynamic mechanical properties of solid material and porous 3DF scaffolds. The molecular weight of the starting PEG blocks used in the copolymer synthesis varied from 300 to 1000 g/mol. The PEOT/PBT weight ratio in the blocks used varied from 55/45 to 80/20. This corresponded to an increase of the swelling ratio Q from 1.06 to 2.46, and of the mesh size ξ from ∼ 9 Å to ∼ 47 Å. With increased swelling, dynamic mechanical analysis (DMA) revealed a decrease in elastic response and an increase of viscoelasticity. Thus, by coupling structural and chemical characteristics, the viscoelastic properties of PEOT/PBT 3DF scaffolds may be fine tuned to achieve mechanical requirements for a variety of engineered tissues. Ultimately, the combination of 3DF and DMA may be useful to validate the hypothesis that mimicking the biomechanical behavior of a specific tissue for its optimal replacement is an important issue for at least some tissue‐engineering applications. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Determination of bradykinin and arg‐bradykinin in rat muscle tissue by microdialysis and capillary column‐switching liquid chromatography with mass spectrometric detection
Authors: Wilson Steven Ray , Boix Fernando , Holm Anders , Molander Pål , Lundanes Elsa , Greibrokk Tyge 
Published: August 2005

AbstractQuantification of bradykinin peptides in limited amounts of rat muscle tissue dialysate has been performed using a packed capillary LC‐ESI‐TOF‐MS method. The micro dialysate samples (450 μL) with added internal standard were loaded onto a 1 mm×5 mm loading column packed with 5 μm Kromasil C18 particles by a carrier solution of 0.1% formic acid in ACN/water (5:95, v/v) at a flow rate of 250 μL/min for online preconcentration of the analytes. Back‐flushed elution onto a 150 mm× 0.5 mm Zorbax C18 column packed with 5 μm particles was conducted using a linear solvent ACN/H2O gradient containing 0.1% formic acid. (Tyr8)‐bradykinin was used as an internal standard and was added to the dialysis sample prior to injection. Baseline separation of bradykinin, arg‐bradykinin and (tyr8)‐bradykinin was achieved within 10 min. Positive ESI was performed in the m/z range of 200–1300. The method was validated in the range 0.2–1.0 ng/mL dialysate, yielding correlation coefficients of 0.995 and 0.990 for bradykinin and arg‐bradykinin, respectively. The within‐assay and between‐assay precisions were between 4.3–9.6% and 6.2–10.6%, respectively. Both arg‐bradykinin and bradykinin were detected in dialysate from rat muscle tissue, <?tws=0p><?twb=.18w>at concentrations of 0.1 and 0.4 ng/mL for bradykinin and arg‐bradykinin, respectively, confirming the presence of arg‐bradykinin in rat muscles.
Analysis of Internet topology with a three‐level components model
Authors: Ida Takanori 
Published: August 2005

AbstractThe vertical structure of the Internet is considered as having three‐level components: backhyphen‐bone‐level interconnection, mid‐level transit, and local‐level access. This paper considers single and cross mergers between an integrated provider and an entrant in the different area. As a result of these mergers, cross entry, in which both integrated providers merge with the retail entrants in the other areas, is more socially desirable than single entry, in which only one firm merges, which is, in turn, preferred to no entry. Copyright © 2005 John Wiley & Sons, Ltd.
GABA modulates Drosophila circadian clock neurons via GABAB receptors and decreases in calcium
Authors: Hamasaka Yasutaka , Wegener Christian , Nässel Dick R. 
Published: August 2005

AbstractCircadian clocks play vital roles in the control of daily rhythms in physiology and behavior of animals. In Drosophila, analysis of the molecular and behavioral rhythm has shown that the master clock neurons are entrained by sensory inputs and are synchronized with other clock neurons. However, little is known about the neuronal circuits of the Drosophila circadian system and the neurotransmitters that act on the clock neurons. Here, we provide evidence for a new neuronal input pathway to the master clock neurons, s‐LNvs, in Drosophila that utilizes GABA as a slow inhibitory neurotransmitter. We monitored intracellular calcium levels in dissociated larval s‐LNvs with the calcium‐sensitive dye Fura‐2. GABA decreased intracellular calcium in the s‐LNvs and blocked spontaneous oscillations in calcium levels. The duration of this response was dose‐dependent between 1 nM and 100 μM. The response to GABA was blocked by a metabotropic GABAB receptor (GABAB‐R) antagonist, CGP54626, but not by an ionotropic receptor antagonist, picrotoxin. The GABAB‐R agonist, 3‐APMPA, produced a response similar to GABA. An antiserum against one of the Drosophila GABAB‐Rs (GABAB‐R2) labeled the dendritic regions of the s‐LNvs in both adults and larvae, as well as the dissociated s‐LNvs. We found that some GABAergic processes terminate at the dendrites of the LNvs, as revealed by GABA immunostaining and a GABA‐specific GAL4 line (GAD1‐gal4). Our results suggest that the s‐LNvs receive slow inhibitory GABAergic inputs that decrease intracellular calcium of these clock neurons and block their calcium cycling. This response is mediated by postsynaptic GABAB receptors. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005
Three‐dimensional immersed finite element methods for electric field simulation in composite materials
Authors: Kafafy R. , Lin T. , Lin Y. , Wang J. 
Published: August 2005

AbstractThis paper presents two immersed finite element (IFE) methods for solving the elliptic interface problem arising from electric field simulation in composite materials. The meshes used in these IFE methods can be independent of the interface geometry and position; therefore, if desired, a structured mesh such as a Cartesian mesh can be used in an IFE method to simulate 3‐D electric field in a domain with non‐trivial interfaces separating different materials. Numerical examples are provided to demonstrate that the accuracies of these IFE methods are comparable to the standard linear finite element method with unstructured body‐fit mesh. Copyright © 2005 John Wiley & Sons, Ltd.
The maximization of fundamental frequency of structures under arbitrary initial stress states
Authors: de Faria Alfredo R. , de Almeida Sérgio Frascino M. 
Published: August 2005

AbstractA general technique is proposed to maximize the lowest natural frequency of structures subjected to an arbitrary state of initial stresses. The arbitrary states of initial stresses are represented by nondimensional loading parameters that describe an admissible loading space, i.e. every possible initial stress state lies within the admissible loading space. The key to the proposed optimization strategy is shown to be the concavity of the first natural frequency with respect to variations of the loading parameters within the admissible loading space. A rigorous demonstration is presented to show that, provided buckling has not occurred, all the possible initial stress states must not be considered. Instead, assessment of only a small number of initial stress states must be done in order to guarantee that the first natural frequency does not decrease for all the other initial stress states within the admissible loading space. A minimax optimization technique is used to maximize the lowest natural frequency of a simply supported rectangular plate where the thickness distribution is the design variable and normal and shear initial stress states are considered. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis and properties of highly branched polycations with an aliphatic polyether scaffold
Authors: Schwab Ernst , Mecking Stefan 
Published: August 2005

AbstractCationic polyelectrolytes with pyridinium and 1,2‐dimethylimidazolium functionalities based on a hyperbranched polyglycerol scaffold with a narrow polydispersity were prepared by a polymer analogous reaction in a one‐pot synthesis. By the variation of the spacer lengths between the cationic functionalities and polyether scaffold, a simple method was developed to adjust the charge density and flexibility of the polycations, as reflected by their glass‐transition temperature. The polyelectrolytes were further characterized in detail by1H NMR,13C NMR, and IR spectroscopy, as well as thermogravimetric analysis. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4609–4617, 2005
Interaction‐induced magnetic field asymmetry of nonlinear mesoscopic electrical transport
Authors: Büttiker Markus , Sánchez David 
Published: August 2005

AbstractWe demonstrate that the nonlinear I–V characteristics of a two‐probe conductor are not an even function of a magnetic field. While the conductance of a two‐probe conductor is even in a magnetic field, we find that already the contributions to the current that are second order in voltage, are in general not even. This implies a departure from the Onsager microreversibility principle in the weakly nonlinear regime. Interestingly, the effect that we find is due to the Coulomb interaction. A measurement of magnetic field asymmetry can be used to determine the effective interaction strength. As a generic example, we discuss the I–V characteristics of a chaotic quantum dot. The ensemble averaged I–V of such a cavity is linear: nonlinearities are due to quantum interference. Consequently, phase‐breaking reduces the asymmetry. We support this statement with a calculation that treats inelastic scattering with the help of a voltage probe. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Association of psychological and physiological measures of stress in health‐care professionals during an 8‐week mindfulness meditation program: mindfulness in practice
Authors: Galantino Mary Lou , Baime Michael , Maguire Maureen , Szapary Philippe O , Farrar John T 
Published: August 2005

AbstractWork stress, burnout, and diminished empathy are prevalent issues for health‐care professionals. Mindfulness meditation (MM) is one commonly used strategy to manage stress. Measuring salivary cortisol allows for the assessment of serum cortisol level, a known stress level indicator. This study evaluated the association of subject‐reported stress symptoms and salivary cortisol in health‐care professionals, in an 8‐week MM program, with data collected prospectively at baseline and 8 weeks after program completion. Questionnaires [Profile of Mood States—Short Form (POMS‐SF), Maslach Burnout Inventory (MBI), and Interpersonal Reactivity Index (IRI)] measured mood, burnout and empathy.A paired t‐test between groups for pre/post‐salivary cortisol yielded no significant change. The POMS‐SF was most sensitive to change (mean increase 12.4; p = 0.020). Emotional exhaustion, measured in the MBI, was also affected by MM (mean decrease 4.54; p = 0.001). Changes in empathy may not have been captured due to either absence of effect of MM on empathy, subject number or scale sensitivity. Baseline and 8‐week correlations between salivary cortisol and survey results, and correlations between changes in these measures, were weak and not statistically significant. Nevertheless, psychometric results present a strong case for additional clinical trials of MM to reduce stress for health‐care professionals. Copyright © 2005 John Wiley & Sons, Ltd.
Variability in the Coordination Modes of 2‐Pyridineformamide Thiosemicarbazone (HAm4DH) in some Zinc(II), Cadmium(II), and Mercury(II) Complexes
Authors: Bermejo Elena , Castiñeiras Alfonso , García‐Santos Isabel , West Douglas X. 
Published: August 2005

AbstractThe reduction of 2‐cyanopyridine by sodium in dry methanol in the presence of thiosemicarbazide produces 2‐pyridineformamide thiosemicarbazone, HAm4DH. The reactions of the potentially tridentate ligand HAm4DH with salts of Zn, Cd, and Hg gave a variety of metal‐ligand complexes. The complexes were characterized by mass spectrometry as well as IR and multinuclear NMR (1H, 13C, 13C CP/MAS, 113Cd, 199Hg) spectroscopy. The crystal structures of [Zn(Am4DH)(OAc)]2·H2O, [Hg(HAm4DH)2Br2]·C2H5OH and $^{1}_{\infty}$[Hg(μ‐S‐Am4DH)Br] were obtained. Coordination of anionic Am4DH− occurs through the pyridyl nitrogen, imine nitrogen and thiolato sulfur atoms, while the neutral ligands in [Hg(HAm4DH)2Br2] coordinate as monodentate ligands through their thione sulfur atoms. One of the acetate ligands in [Zn(Am4DH)(OAc)]2·H2O is bridging monodentate and the other bridging bidentate. $^{1}_{\infty}$[Hg(μ‐S‐Am4DH)Br] features five‐coordinate mercury centers with bridging thiolato sulfur atoms. The intermolecular arrangement is dictated by hydrogen bonding from the amino groups and by π‐π stacking of the pyridine rings.
Synthesis and X‐Ray Single Crystal Structure of Two New Copper Complexes with the Redox Active Ligand 1,10‐Phenanthroline‐5,6‐dione
Authors: Galet Ana , Muñoz M. Carmen , Agustí Gloria , Martínez Víctor , Gaspar Ana B. , Real José Antonio 
Published: August 2005

AbstractThe synthesis and the crystal structures of the complexes [Cu(LI)2](ClO4) (1) and [Cu(LI)(CH3CN)2(ClO4)2] (2) are reported. 1 crystallizes in the monoclinic space group C2/c with the unit cell dimensions a = 13.169(4), b = 12.289(3), c = 14.732(3) Å, β = 109.03(2)° and Z = 4. Copper(I) is coordinated to four N atoms of the two 1,10‐Phenanthroline‐5,6‐dione (LI) ligands with a two‐fold axis passing between the ligands. The copper(II) compound 2 crystallizes in the orthorhombic space group Pbn21 with unit cell dimensions of a = 7.498(5), b = 23.492(7), c = 12.363(4) Å and Z = 4. Copper(II) coordination can be described as a distorted octahedron with the N donor atoms of one LI ligand and of two molecules of CH3CN occupying the equatorial positions completed by two oxygen atoms of the two perchlorate molecules in the axial positions.
Effect of the Atmospheric Conditions on the Thermal Behaviour of the Sarkinite Mineral, Mn2(OH)AsO4
Authors: de Pedro I. , Rojo J. M. , Insausti M. , Mesa J. L. , Arriortua M. I. , Rojo T. 
Published: August 2005

AbstractThe sarkinite, Mn2(OH)AsO4, mineral has been synthesized in laboratory as pure phase under mild hydrothermal conditions. The decomposition process of the hydroxiarsenate compound is strongly dependent on the atmospheric conditions. The results of the thermal treatment in air or argon are quite different. In this way, a new black phase appears in air atmosphere in the 400‐630 °C temperature range whereas under inert atmosphere the structure of Mn2(OH)AsO4 at room temperature is maintained up to 560 °C. The weight loss is attributed to the partial decomposition of Mn2(OH)AsO4 above 400 °C with removal of OH groups and the oxidation of MnII to MnIII that occur simultaneously. Above 650 °C, the structures of the intermediate compounds are broken and the evolution of the inorganic residues gives rise to the formation of arsenates and oxides of MnII and MnIII in inert and air atmospheres.
Electrochemical Synthesis and Characterization of Tin(IV) Complexes of Dianionic Terdentate Schiff Base Ligands
Authors: Labisbal Elena , Rodríguez Laura , Vizoso Araceli , Alonso Mónica , Romero Jaime , García‐Vázquez José‐Arturo , Sousa‐Pedrares Antonio , Sousa Antonio 
Published: August 2005

AbstractTin(IV) complexes of the series of dianionic terdentate Schiff bases N‐[(2‐pyrroyl)methylidene]‐N′‐tosylbenzene‐1,2‐diamine, (H2L1), N‐[(2‐hydroxyphenyl)methylidene]‐N′‐tosylbenzene‐1,2‐diamine (H2L2) and some R substituted 2‐{[(2‐hydroxyphenyl)imino]methyl}phenols [R = H (H2L3), 4,6‐(OCH3)2 (H2L4), 3‐(OC2H5) (H2L5) and 3,5‐Br2 (H2L6)] have been synthesized. The compounds were obtained by the electrochemical oxidation of a tin anode in a cell containing an acetonitrile solution of the corresponding ligand. The complex [SnL12] was also obtained by reaction of SnCl2·2H2O and H2L1 in methanol in the presence of triethylamine. The crystal structure of the ligand [H2L6] and the complexes [SnL12] (1), [SnL22] (2), [SnL32] (3) and [SnL62] (6) were determined by X‐ray diffraction. In the complexes, the tin atom is in an octahedral environment coordinated by two dianionic terdentate ligands. Spectroscopic data for the complexes (IR, 1H and 119Sn NMR and mass spectra) are discussed and related to structural information.
Infrared Spectroscopic Studies on the Surface Chemistry of High‐Surface‐Area Gallia Polymorphs
Authors: Delgado M. Rodríguez , Areán C. Otero 
Published: August 2005

AbstractPolymorphs α, β, and γ of Ga2O3 having hexagonal (corundum‐type), monoclinic and cubic (spinel‐type) structure, respectively, were prepared in a high‐surface‐area form, and characterized by powder X‐ray diffraction. Nitrogen adsorption at 77 K showed these gallia samples to have specific surface areas of 77 (α‐Ga2O3), 40 (β‐Ga2O3) and 120 m2 g−1 (γ‐Ga2O3). Fourier transform infrared spectroscopy of adsorbed carbon monoxide (at 77 K) and pyridine (at room temperature) showed that the three gallia polymorphs have a very similar surface Lewis acidity, regardless of their different crystal structures. This Lewis acidity was assigned, mainly, to coordinatively unsaturated tetrahedral Ga3+ ions situated on the surface of the small crystallites which constitute the different metal oxide varieties. Ga3+···CO adducts formed after CO adsorption gave (in all cases) a characteristic C–O stretching band at 2195–2200 cm−1, while Lewis‐type adducts formed with adsorbed pyridine were characterized by IR absorption bands at 1610–1612 and 1446–1450 cm−1. The three (partially hydroxylated) gallia polymorphs showed also a very weak Brønsted acidity, which they manifested by forming hydrogen‐bonded adducts with both CO and pyridine; however no protonation of adsorbed pyridine occurred.
Preparation and Properties of Nickel and Iron Oxides obtained by Calcination of Layered Double Hydroxides
Authors: Ruano‐Casero R. J. , Pérez‐Bernal M. E. , Rives V. 
Published: August 2005

AbstractA constant pH precipitation method has been applied to obtain solids with Ni/Fe molar ratios of 2/1, 3/2, 1/1, 2/3, and 1/2. In all cases, a phase with the hydrotalcite‐like structure is obtained, containing NiII and FeIII in the brucite‐like layers and carbonate in the interlayer, and, for samples with a Ni/Fe molar ratio lower than 2/1, amorphous hydrated iron oxides, undetected by X‐ray diffraction, are also formed. The solids have been characterized by element chemical analysis, powder X‐ray diffraction, differential thermal analysis, thermogravimetric and differential thermogravimetric analysis, FT‐IR spectroscopy, temperature‐programmed reduction and assessment of specific surface area by nitrogen adsorption at −196 °C. In all cases reduction leads to zero‐valent state for the metals, reduced nickel particles probably favouring reduction of FeIII species; the specific surface area increases with the iron content, probably due to the amorphous nature of the hydrated iron oxides formed. Calcination at 1200 °C in air leads to well crystallized solids, formed by NiFe2O4 spinel and, additionally, rocksalt‐type NiO for Ni/Fe ratios larger than 1/2. In this way, solids with tailored compositions of these two phases can be prepared.
Complexes of Cu2(μ‐OAc)4(H2O)2 with 1,10‐Phenanthroline and Comparison with those of 2,2′‐Bipyridine. Crystal Structure of the Dimer [Cu(OAc)2(phen)](μ‐H2O)
Authors: Barquín Montserrat , Garmendia María J. González , Larrínaga Liher , Pinilla Elena , Torres María R. 
Published: August 2005

AbstractThe two complexes of composition Cu2(OAc)4(phen)(H2O)2 (1) andCu2(OAc)4(phen)2(H2O) (2) have been synthesized and characterized by chemical analysis and IR and electronic spectroscopies. Compound 2 has the structure of a dimer with a phenanthroline molecule and two monodentate acetate groups coordinated to each copper atom and a water molecule as the only bridging ligand between them. Each copper atom has a distorted square‐planar pyramidal coordination, determined by two oxygen atoms at 1.94(3) and 1.959(3) Å, two nitrogen atoms at 2.023(4) Å and the oxygen atom of the bridging water molecule at 2.289(2) Å. The distance between the two copper atoms is of 4.29 Å and the angle Cu(1)‐O(3)‐Cu(1A) 139.2(2)°. The water molecule is involved in two intramolecular hydrogen bonds with non coordinated oxygen atoms. The distance between the molecules of phenanthroline is 3.75 Å. Magnetic and EPR results for Cu2(OAc)4(phen)(H2O)2 (1), Cu2(OAc)4(phen)2(H2O) (2), Cu2(OAc)4(bipy) (3) and Cu2(OAc)4(bipy)2(H2O)2 (4) have been analysed and compared. For 1 and 3 an antiferromagnetic dimer unit [Cu2(μ‐OAc)4] with 2J = −325 and −292 cm−1, respectively, and other two copper atoms without significant magnetic interaction are present. Triplet signals are detected in the EPR spectra. In 2 and 4 there is no practically magnetic exchange and the orthorhombic signals are observed in the EPR spectra.