bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression and characterization of functional recombinant bovine follicle‐stimulating hormone (boFSHα/β) produced in the milk of transgenic rabbits
Authors: Coulibaly S. , Besenfelder U. , Miller I. , Zinovieva N. , Lassnig C. , Kotler T. , Jameson J.L. , Gemeiner M. , Müller M. , Brem G. 
Published: October 2002

AbstractBovine follicle‐stimulating hormone (boFSH) is a heterodimeric glycoprotein that belongs to the pituitary gonadotropins. Bioactive FSH is composed of α and β subunits which require extensive N‐glycosylation and sialylation. The mammary gland of transgenic livestock is an attractive source for the synthesis of post‐translationally modified proteins. Two mammary gland‐specific gene constructs with the cDNA for the boFSH alpha (boFSHα) and beta (boFSHβ) subunits controlled by bovine alpha‐s1 casein regulatory sequences were co‐microinjected into fertilized rabbit oocytes. Two FSHα/FSHβ double transgenic rabbit lines were established. The transgene expression was strictly lactation and mammary gland specific. Protein analysis revealed the presence of the boFSH heterodimer in the milk of transgenic rabbits showing a molecular weight similar to that of purified pituitary gland derived boFSH (boFSH‐P). Subunit specific antibodies detected both polypeptides with the expected molecular sizes. Biochemical characterization demonstrated the expected isoelectric points of the recombinant boFSH. The presence of the post‐translationally added terminal sialic acid residues was indicated by wheat germ agglutinin (WGA) lectin Western blotting. The biological activity of the recombinant mammary gland produced boFSH was determined using a FSH‐dependent reporter cell line. The bioactivity of the recombinant boFSH was comparable to that of purified boFSH‐P. Mol. Reprod. Dev. 63: 300–308, 2002. © 2002 Wiley‐Liss, Inc.
Histone H1‐like protein and a testis‐specific variant in the reproductive tracts of Octopus vulgaris
Authors: Mennella Maria Rosaria Faraone , Farina Benedetta , Irace Maria Venezia , Cristo Carlo Di , Cosmo Anna Di 
Published: October 2002

AbstractIn this study, we have identified a 28‐kDa protein resembling the linker H1 in the testis and prostate of the reproductive system of Octopus vulgaris. This protein, OvH1, was partially purified by reverse phase high‐pressure liquid chromatography (HPLC) of the perchloric acid extract from testis nuclei. It showed electrophoretic mobility, CD spectrum and amino acid composition highly comparable with those of the mammalian histone. Moreover, it was microheterogeneous, as resulted from prostate and testis HPLC and mass spectrometry analyses. Such analysis showed that in testis there are two H1 subfractions, which do not appear in the prostate. Amino acid composition of the major testis specific variant (OvH1t) showed high similarity with rat testis specific H1t. The histone‐like nature of OvH1 was confirmed by its ability to bind DNA as tested both by circular dichroism and protection of the nucleic acid toward deoxyribonuclease I activity. The circular dichroism spectra of Octopus DNA in the absence and presence of increasing amounts of the protein showed a dose‐dependent effect, leading to a progressive compactness of the polynucleotide. OvH1/DNA complexes were also resistant to nuclease digestion. The presence of H1 in the testis and prostate of the reproductive system of Octopus is discussed in light of the fact that there is a similarity between its behavior and that of vertebrates. Mol. Reprod. Dev. 63: 355–365, 2002. © 2002 Wiley‐Liss, Inc.
High‐resolution, spin‐echo BOLD, and CBF fMRI at 4 and 7 T
Authors: Duong Timothy Q. , Yacoub Essa , Adriany Gregory , Hu Xiaoping , Ugurbil Kamil , Vaughan J. Thomas , Merkle Hellmut , Kim Seong‐Gi 
Published: October 2002

AbstractWith growing interest in noninvasive mapping of columnar organization and other small functional structures in the brain, achieving high spatial resolution and specificity in fMRI is of critical importance. We implemented a simple method for BOLD and perfusion fMRI with high spatial resolution and specificity. Increased spatial resolution was achieved by selectively exciting a slab of interest along the phase‐encoding direction for EPI, resulting in a reduced FOV and number of phase‐encoding steps. Improved spatial specificity was achieved by using SE EPI acquisition at high fields, where it is predominantly sensitive to signal changes in the microvasculature. Robust SE BOLD and perfusion fMRI were obtained with a nominal in‐plane resolution up to 0.5 × 0.5 mm2 at 7 and 4 Tesla, and were highly reproducible under repeated measures. This methodology enables high‐resolution and high‐specificity studies of functional topography in the millimeter to submillimeter spatial scales of the human brain. Magn Reson Med 48:589–593, 2002. © 2002 Wiley‐Liss, Inc.
Human erythrocyte ghosts: Exploring the origins of multiexponential water diffusion in a model biological tissue with magnetic resonance
Authors: Thelwall Peter E. , Grant Samuel C. , Stanisz Greg J. , Blackband Stephen J. 
Published: October 2002

AbstractA tissue model composed of erythrocyte ghosts was developed to study the effects of compartmentation on the MR signal acquired from biological tissues. This simple and flexible model offers control over the biophysical parameters that contribute to multicomponent signals arising from cellular systems. Cell density, size, intra‐ and extracellular composition, and membrane permeability can be independently altered. The effects of cell density and cell size on water diffusion properties were assessed. The data demonstrate non‐monoexponential water diffusion in ghost cell suspensions of 17–67% cell density. Data were analysed with the widely employed two‐compartment (biexponential) model, and with a two‐compartment model that accounted for exchange between compartments. Water exchange between the intra‐ and extracellular compartments appeared to be significant over the range of diffusion times studied (7–35 ms). The biexponential fit to the ghost data appeared to be underparameterised as the ADCs and relative fractions of the fast and slow components were dependent on the experimental acquisition parameters, specifically the diffusion time. However, both analysis methods proved effective at tracking changes in the ghost model when it was perturbed. This was demonstrated with cell density variation, cell swelling and shrinkage experiments, and reduction of membrane water permeability using a water channel blocker (pCMBS). We anticipate that this model system could be used to investigate compartmental diffusion effects to simulate a range of pathologies, especially ischemic stroke. Magn Reson Med 48:649–657, 2002. © 2002 Wiley‐Liss, Inc.
Quadriplegic areflexic ICU illness: Selective thick filament loss and normal nerve histology
Authors: Sander Howard W. , Golden Marianna , Danon Moris J. 
Published: October 2002

AbstractAreflexic quadriplegia that occurs in the intensive care unit (ICU) is commonly ascribed to critical illness polyneuropathy based upon electrophysiology or muscle light microscopy. However, electron microscopy often documents a selective thick filament loss myopathy. Eight ICU patients who developed areflexic quadriplegia underwent biopsy. Seven patients had received steroids, and 2 had also received paralytic agents. Electrodiagnostic studies revealed absent or low‐amplitude motor responses in 7. Sensory responses were normal in 5 of 6 and absent in 1. Initial electromyography revealed absent (n = 3), small (n = 3), or polyphasic (n = 1) motor unit potentials, and diffuse fibrillation potentials (n = 5). In all 8, light microscopy of muscle revealed numerous atrophic‐angulated fibers and corelike lesions, and electron microscopy revealed extensive thick filament loss. Morphology of sural and intramuscular nerves, and, in one autopsied case, of the obturator nerve and multiple nerve roots, was normal. Although clinical, electrodiagnostic, and light microscopic features mimicked denervating disease, muscle electron microscopy revealed thick filament loss, and nerve histology was normal. This suggests that areflexic ICU quadriplegia is a primary myopathy and not an axonal polyneuropathy. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 499–505, 2002
Allotransplanted nerves regenerate inhibitory synapses on a crayfish muscle: Possible postsynaptic specification
Authors: Govind C.K. , Coulthard Rosalind , Pearce Joanne 
Published: October 2002

AbstractDonor nerves of different origins, when transplanted onto a previously denervated adult crayfish abdominal superficial flexor muscle (SFM), regenerate excitatory synaptic connections. Here we report that an inhibitory axon in these nerves also regenerates synaptic connections based on observation of nerve terminals with irregular to elliptically shaped synaptic vesicles characteristic of the inhibitory axon in aldehyde fixed tissue. Inhibitory terminals were found at reinnervated sites in all 12 allotransplanted‐SFMs, underscoring the fact that the inhibitory axon regenerates just as reliably as the excitatory axons. At sites with degenerating nerve terminals and at sparsely reinnervated sites, we observe densely stained membranes, reminiscent of postsynaptic membranes, but occurring as paired, opposing membranes, extending between extracellular channels of the subsynaptic reticulum. These structures are not found at richly innervated sites in allotransplanted SFMs, in control SFMs, or at several other crustacean muscles. Although their identity is unknown, they are likely to be remnant postsynaptic membranes that become paired with collapse of degenerated nerve terminals of excitatory and inhibitory axons. Because these two axons have uniquely different receptor channels and intramembrane structure, their remnant postsynaptic membranes may therefore attract regenerating nerve terminals to form synaptic contacts selectively by excitatory or inhibitory axons, resulting in postsynaptic specification. © 2002 Wiley Periodicals, Inc. J Neurobiol 53: 80–89, 2002
Sobolev space preconditioning for Newton's method using domain decomposition
Authors: Axelsson O. , Faragó I. , Karátson J. 
Published: October 2002

AbstractAn inner–outer iteration is constructed for ill‐conditioned non‐linear elliptic boundary value problems, using a damped inexact Newton Method for the outer and a conjugate gradient method for the inner iteration. The focus is on efficient preconditioning for the inner iteration. Sobolev space background is used to construct preconditioners as discretizations of appropriately chosen piecewise constant coefficient elliptic operators. The combination of this theoretical approach with a suitable domain decomposition idea results in well‐structured preconditioners that are able to compensate for the sharp gradients of the coefficients. Furthermore, convergence estimates and mesh independence of the condition numbers are direct consequences of the method. Copyright © 2002 John Wiley & Sons, Ltd.
Discrete singular convolution and its application to the analysis of plates with internal supports. Part 2: Applications
Authors: Xiang Y. , Zhao Y. B. , Wei G. W. 
Published: October 2002

AbstractPart 2 of this series of two papers presents the applications of the discrete singular convolution (DSC) algorithm. The main purpose of this paper is to explore the utility, test the accuracy and examine the convergence of the proposed approach for the vibration analysis of rectangular plates with internal supports. Both partial internal line supports and complex internal supports are considered for 21 square plates of various combinations of edge support conditions. The effects of different size, shape and topology of the internal supports and different boundary conditions on the vibration response of plates are investigated. The partial internal line supports may vary from a central point support to a full range of cross or diagonal line supports. Several closed‐loop supports, such as ring, square and rhombus, and their combinations are studied for complex internal supports. Convergence and comparison studies are carried out to establish the correctness and accuracy of the DSC algorithm. The DSC results are compared with those in the available literature obtained by using other methods. Numerical results indicate that the DSC algorithm exhibits controllable accuracy for plate analysis and shows excellent flexibility in handling complex geometries, boundary conditions and support conditions. Copyright © 2002 John Wiley & Sons, Ltd.
Numerical study of consistency of rate constitutive equations with elasticity at finite deformation
Authors: Lin Ruocheng 
Published: October 2002

AbstractThe present work is concerned with the numerical study of the elasticity consistency of the spatial rate equations using the conventional Oldroyd, Truesdell, Cotter–Rivlin, Jaumann and Green–Naghdi rates and the three novel co‐rotational ΩE‐ and Ω¯L‐based, logarithmic rates, and of the rotated material rate equation describing the relationship between the material time derivatives of the rotated Kirchhoff stress and material logarithmic strain. To this end, three integration procedures for updating stress are presented. The stress responses of several typical deformation processes are simulated. According to the numerical results we know that among the spatial rate equations only the logarithmic rate equation is consistent with elasticity under constant material parameters. Integrating the other spatial rate equations will provide path‐dependent stress response. These numerical conclusions support the arguments in H. Xiao et al. (Acta Mechanica 1999; 138:31–50). The reasons leading to elasticity inconsistency of spatial rate equations are analysed. If the material parameters are assumed to be strain‐dependent, the logarithmic rate equation loses also its elasticity‐consistent property. The numerical results prove also that the spatial logarithmic and rotated material rate equations are equivalent to each other. Copyright © 2002 John Wiley & Sons, Ltd.
Sensorless DC motor drive via optimal observer‐based servo control
Authors: Leephakpreeda Thananchai 
Published: October 2002

AbstractThis paper proposes an alternative design of a sensorless DC motor drive via optimal observer‐based servo control. Without the speed sensor, the extended Luenberger observer is implemented to estimate the rotor speed of the DC motor in the presence of the disturbance torque. With this knowledge of the speed estimated from the observer, the servo state‐feedback controller can drive such a rotor speed to follow the desired one. The stability and performance of the DC drive system can be guaranteed by the optimal control which minimizes the H2 norm of the closed‐loop feedback control and observer system. The simulation and experiment studies are demonstrated for the effectiveness of the proposed control methodology in a practical approach for the sensorless DC drive. Copyright © 2002 John Wiley & Sons, Ltd.
Gamma radiation induced graft copolymerization of acrylamide onto EPDM blended with PE
Authors: El‐Nesr E. M. 
Published: October 2002

AbstractGamma radiation induced grafting of acrylamide (AAm) onto vulcanized strips of EPDM and EPDM/PE blends has been carried out. The effects of different parameters on the graft yield have been investigated. These parameters include: radiation dose, monomer concentration, diluent composition and types of inhibitors. It has been found that water is the most appropriate solvent. The preswelling of crosslinked rubber samples in cyclohexane prior to grafting enhances the grafting and the addition of methanol to water as binary diluent in the ratio (1 : 1) decreases the graft yield. The presence of Mohr's salt and copper sulfate in the reaction mixture in the molar ratio (2.1 : 0.5) markedly increases the graft yield. Evidence of grafting have been conducted using thermal analysis as well as swelling measurements in water. Also, it has been found that the mechanical properties of the blends decrease at graft yield 13%. Copyright © 2002 John Wiley & Sons, Ltd.
Epoxy‐functionalized, low‐glass‐transition‐temperature latex. II. Interdiffusion versus crosslinking in the presence of a diamine
Authors: Tronc Frédéric , Chen Warner , Winnik Mitchell A. , Eckersley Sarah T. , Rose Gene D. , Weishuhn J. M. , Meunier D. M. 
Published: October 2002

AbstractThis article describes the results of experiments examining the competition between the polymer diffusion rate and the crosslinking rate in low‐glass‐transition‐temperature, epoxy‐containing latex films in the presence of a diamine. We examined films formed from donor‐ and acceptor‐labeled poly(butyl acrylate‐co‐methyl methacrylate‐co‐glycidyl methacrylate) copolymer latex and studied the influence of several parameters on the growth rate of gel content and the rate of polymer diffusion. These factors include the molecular weight of the latex polymer, the presence or absence of a diamine crosslinking agent, and the cure protocol. The results were compared to the predictions of a recent theory of the competition between crosslinking and polymer diffusion across interfaces. In the initially formed films, polymer diffusion occurs more rapidly than the chemical reaction rate. Therefore, these films fall into the fast‐diffusion category of this model. In our system (unlike in the model), the latex polymer has a broad distribution of molecular weights and a distribution of diffusivities. The shortest chains contribute to the early time diffusion that we measure. At later stages of our experiment, slower diffusing species contribute to the signal that we measure. The diffusion time decreases substantially, and we observe a crossover to a regime in which the chemical reaction dominates. The increases in chain branching and gel formation bring polymer diffusion to a halt. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4098–4116, 2002
Fluoropolyethers end‐capped by polar functional groups. III. Kinetics of the reactions of hydroxy‐terminated fluoropolyethers and model fluorinated alcohols with cyclohexyl isocyanate catalyzed by organotin compounds
Authors: Mashlyakovskiy Leonid , Khomko Elena , Volynkina Natalya , Tonelli Claudio 
Published: October 2002

AbstractThe kinetics of the dibutyltin dilaurate (DBTDL)‐catalyzed urethane formation reactions of cyclohexyl isocyanate (CHI) with model monofunctional fluorinated alcohols and fluoropolyether diol Z‐DOL H‐1000 of various molecular weights (100–1084 g mol−1) in different solvents were studied. IR spectroscopy and chemical titration methods were used for measuring the rate of the total NCO disappearance at 30–60 °C. The effects of the reagents and DBTDL catalyst concentrations, the solvent and hydroxyl‐containing compound nature, and the temperature on the reaction rate and mechanism were investigated. Depending on the initial reagent concentration and solvent, the reactions could be well described by zero‐order, first‐order, second‐order, or more complex equations. The reaction mechanism, including the formation of intermediate ternary or binary complexes of reagents with the tin catalyst, could vary with the concentration and solvent and even during the reaction. The results were treated with a rate expression analogous to those used for enzymatic reactions. Under the explored conditions, the rate of the uncatalyzed reaction of fluorinated alcohols with CHI was negligible. Moreover, there was no allophanate formation, nor were there other side reactions, catalysis by urethane in the absence of DBTDL, or a synergetic effect in the presence of the tin catalyst. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3771–3795, 2002
Synthesis and characterization of novel poly(vinyl chloride)‐based grafts: Poly(vinyl chloride‐co‐2‐chloropropene) fitted with multiple high‐glass‐transition‐temperature polyolefin branches
Authors: Pi Zhengjie , Kennedy Joseph P. , Summers James W. 
Published: October 2002

AbstractThe tertiary chlorine (Clt) content of vinyl chloride/2‐chloropropene copolymers [P(VC‐co‐2CP)] was determined by NMR spectroscopy. Copolymers containing 6.8–47.0 Clt's per P(VC‐co‐2CP) chain were used to initiate the cationic grafting of α‐methylstyrene, norbornadiene, indene, and norbornene with Et2AlCl under various conditions. Grafting was demonstrated by selective solvent extraction, and the effect of the experimental conditions on the grafting efficiency was examined. Select rheological and thermal characteristics of P(VC‐co‐2CP) grafts, including the glass‐transition temperature, heat deflection temperature, and discoloration upon heating, were studied. P(VC‐co‐2CP) carrying 7–11 poly(α‐methylstyrene) or polynorbornadiene branches per chain raised the glass‐transition temperature to, or above, that of a blend control. P(VC‐co‐2CP)s fitted with polyindene or polynorbornene branches were less effective in raising the mechanical properties. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3644–3651, 2002
Radical telomerization of 1,3‐butadiene with perfluoroalkyl iodides in the presence of potassium carbonate
Authors: Lebreton Pierre , Ameduri Bruno , Boutevin Bernard , Cot Didier , Corpart Jean‐Marc 
Published: October 2002

AbstractThe radical telomerization of 1,3‐butadiene with perfluoroalkyl iodides (C6F13I or merely C8F17I) initiated by di‐tert‐butyl peroxide was studied in the presence of various amounts of potassium carbonate at 145 °C in acetonitrile. The influence of this salt on both the kinetics and the telomer characteristics (color, molar mass, and functionality) was established. First, the determination of the chain‐transfer constant of C8F17I led to a value (2.52) similar to that obtained under the same conditions without any K2CO3 (2.59). Second, 1,3‐butadiene conversion was much faster, and the molar mass/time profiles were also quite different, revealing the formation of high molar mass polymers at the end of conversion, which was not observed in previous studies without any K2CO3. Moreover, great improvements in the functionality of the fluorinated telomers were achieved (closer to unity). The products were also not as colored as before (black in the absence of K2CO3), and this allowed valuable application tests. With electronic microscopy, K2CO3 was shown to neutralize hydrogen iodide (HI) produced in the course of the reaction, which caused major drawbacks (e.g., low functionality and dark color). © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3743–3756, 2002
Effect of the segmental mobility restriction on the thermoset chemical kinetics
Authors: Antonucci V. , Giordano M. , Nicolais L. 
Published: October 2002

AbstractThe cure kinetics of an epoxy–amine commercial thermoset system have been investigated with the isothermal differential scanning calorimetry technique. In particular, a kinetic study has been performed in the glass–transition zone, in which diffusion phenomena compete with the chemical transformations and the overall reaction rate is partially slowed by the reduced segmental chain mobility. A generalized form of the Vogel equation has been formulated to account for the effect of the increasing glass–transition temperature on the chain mobility and, therefore, on the overall reaction rate. The kinetic model has been expressed with two factors representing the chemical reaction rate and the segmental mobility reduction. As the main result, the activation energy relative to the diffusion phenomena has been found to be very low, having a value of 42.5 K ≈ 0.356 kJ/mol, which is compatible only with the small‐angle rotation of the reactive unit. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3757–3770, 2002