bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Characterization of Three‐Component Polyelectrolytic Amphiphilic Model Networks
Authors: Hadjiantoniou Natalia , Triftaridou Aggeliki I. , Georgiou Theoni K. , Patrickios Costas S. 
Published: August 2005

AbstractTwo hydrophilic monomers, 2‐(dimethylamino)ethyl methacrylate (DMAEMA, ionizable) and methoxy hexa(ethylene glycol) methacrylate (HEGMA, non‐ionic), and one hydrophobic monomer, n‐butyl methacrylate (BuMA) were copolymerized via group transfer polymerization (GTP) to prepare eight equimolar, isomeric, amphiphilic terpolymer networks. The degree of swelling in acidic water of these networks varied, depending on network structure.
A Study of Probe Characteristics on the Diffusion Process in Materials Containing Acryloxy and Acrylate Units
Authors: Galiatsatos Vassilios , Sherman B. Jeffrey 
Published: August 2005

AbstractWe study the diffusion of an atomic probe in materials used in restorative dentistry. We rely on computer simulation and on a version of transition state theory to access the diffusion regimes of interest. We find that the calculated logD values are in good agreement with reported results in other glassy polymeric materials. We report the effect of atomic mass and probe radius on the diffusion process.
Improved Dental Composites Utilizing Dibenzylidene Sorbitol Networks
Authors: Wilder Elizabeth A. , Antonucci Joseph M. 
Published: August 2005

AbstractDibenzylidene sorbitol (DBS) is a sugar derivative that is capable of self‐organizing into a 3D nanofibrillar network at relatively low concentrations in a wide variety of organic solvents and polymer melts to induce physical gelation. This research was aimed at determining the effect of DBS networks on vinyl conversion, polymerization shrinkage, and mechanical strength of bioactive dental composites containing zirconyl‐modified amorphous calcium phosphate (Zr‐ACP) and a polymer matrix derived from the photopolymerization of ethoxylated bisphenol‐A dimethacrylate (EBPADMA). Flexural strength was enhanced while polymerization shrinkage and its associated stress development were both significantly reduced by the incorporation of DBS into the composites, suggesting that DBS may be a useful additive for dental composites.
Imaging Therapeutic Proteins in Gelatin for Controlled Drug Release
Authors: Wagoner Johnson Amy , Serrano Nilda Juan , Whittington Morgan Abby , Jamison Russell , Choy Young Bin , Choi Hyungsoo , Kim Kyekyoon (Kevin) , DeCarlo Francesco 
Published: August 2005

AbstractPreliminary results from this study show that x‐ray microcomputed tomography can be used to image model proteins for bone inducing growth factors. Small quantities (<1 μg protein/mg gelatin) of soybean trypsin inhibitor labeled with either gold nanoparticles or nonradioactive iodine were detected using synchrotron radiation. These results could lead to a new method of measuring the release profile of therapeutic proteins.
Nanoparticles from Chitosan
Authors: Bodnár Magdolna , Hartmann John F. , Borbély János 
Published: August 2005

AbstractNovel biodegradable nanoparticles were synthesized by chemical modification of the chitosan linear chain. A natural dicarboxylic acid (malic acid) was used as a crosslinking agent for intramolecular covalent condensation reaction to obtain hydrophilic nanoparticles based on chitosan. A variety of methods including, solubility studies, laser light scattering (DLS), transmission electron microscopy (TEM) and nuclear magnetic resonance (NMR) was used to characterize the crosslinked macromolecules.The prepared biodegradable chitosan nanoparticles, soluble in aqueous media, might be useful for various biomedical applications, like injectable drug‐ or gene‐delivery systems.
Preparation and Characterization of Electroactive Biopolymers
Authors: Finkenstadt Victoria , Willett J.L. 
Published: August 2005

AbstractBiopolymers have the potential for use as a matrix for applications such as controlled release devices, environmentally sensitive membranes, mimic materials and energetic applications. Renewable resources (such as starch) can be utilized as polymer matrices for electroactive materials that are sensitive to their environment. Natural polymers are generally more environmentally‐friendly and biocompatible than existing synthetic products. Thermoplastic starch is naturally insulative; however, the chemical, electrical, and mechanical properties of the biopolymer matrix can be tailored for specific functionality in a continuous process utilizing reactive extrusion. Conductance can be measured in the solid state by a direct‐current resistance method. Ion‐conducting materials, produced by doping thermoplastic starch and biopolymers with metal halides, have 5 orders of magnitude greater conductance than native materials. There is a correlation between polymer mobility and conductance. Plant or microbial biopolymers with ionic functional groups have shown promise for higher levels of conductance. The conductance approaches the level of synthetic polymer electrolytes.
Role of PI3K/Akt signaling in insulin‐like growth factor‐1 (IGF‐1) skin tumor promotion
Authors: Wilker Erik , Lu Jerry , Rho Okkyung , Carbajal Steve , Beltrán Linda , DiGiovanni John 
Published: August 2005

AbstractOverexpression of human IGF‐1 with the bovine keratin 5 (BK5) promoter (BK5.IGF‐1 transgenic mice) induces persistent epidermal hyperplasia and leads to spontaneous skin tumor formation. In previous work, PI3K and Akt activities were found to be elevated in the epidermis of BK5.IGF‐1 transgenic mice compared to nontransgenic littermates. In the present study, we examined the importance of the PI3K/Akt signaling pathway in mediating the skin phenotype and the skin tumor promoting action of IGF‐1 in these mice. Western blot analyses with epidermal lysates showed that signaling components downstream of PI3K/Akt were altered in epidermis of BK5.IGF‐1 mice. Increased phosphorylation of GSK‐3 (Ser9/21), TSC2(Thr1462), and mTOR(Ser2448) was observed. In addition, hypophosphorylation and increased protein levels of β‐catenin were observed in the epidermis of BK5.IGF‐1 mice. These data suggested that components downstream of Akt might be affected, including cell cycle machinery in the epidermis of BK5.IGF‐1 mice. Protein levels of cyclins (D1, E, A), E2F1, and E2F4 were all elevated in the epidermis of BK5.IGF‐1 mice. Also, immunoprecipitation experiments demonstrated an increase in cdk4/cyclin D1 and cdk2/cyclin E complex formation, suggesting increased cdk activity in the epidermis of transgenic mice. In further studies, the PI3K inhibitor, LY294002, significantly blocked IGF‐1‐mediated epidermal proliferation and skin tumor promotion in DMBA‐initiated BK5.IGF‐1 mice. In addition, inhibition of PI3K/Akt with LY294002 reversed many of the cell cycle related changes observed in untreated transgenic animals. Collectively, the current results supported the hypothesis that elevated PI3K/Akt activity and subsequent activation of one or more downstream effector pathways contributed significantly to the tumor promoting action of IGF‐1 in the epidermis of BK5.IGF‐1 mice. © 2005 Wiley‐Liss, Inc.
Measurement of dielectric constant using a microwave microstrip ring resonator (MMRR) at 10 GHz irrespective of the type of overlay
Authors: Sofin R. G. Sumesh , Aiyer R. C. 
Published: August 2005

AbstractA new equation to measure the dielectric constant of materials using a microwave microstrip ring resonator (MMRR) at 10 GHz by empirically modifying the design equation of the effective dielectric constant of the system is proposed. Each material, with the proper size of interest, is overlaid on the MMRR and the change in resonance frequency caused by the change of effective dielectric constant of the system is measured, which depends on the dielectric constant, thickness, and type of overlay (complete or partial). No equations are available for obtaining the dielectric constant of the materials, which are used as partial overlays. The proposed equation can be used for both a complete and a crossed partial overlay. Validation of the equation is done using different dielectric materials and is in good agreement with the experimental results (within ±1%). This will be useful in applications such as grain‐moisture sensing using MMRR. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 11–14, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21066
Conductor and dielectric‐property extraction using microstrip tee resonators
Authors: Fulford Andrew R. , Wentworth Stuart M. 
Published: August 2005

AbstractA pair of microstrip tee resonators, each with a different impedance resonating element, are employed to extract conductor‐sheet resistance as well as dielectric properties. The method's performance is evaluated for copper lines on microwave laminate substrate. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 14–16, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21067
On the evaluation of self‐patch integrals in the method of moments
Authors: Knockaert Luc , Olyslager Frank , Vande Ginste Dries 
Published: August 2005

AbstractStarting with the general expression for the m‐dimensional scalar Green's function or its singular part, we transform the 2n‐dimensional moment integral into an n‐dimensional integral in the Fourier domain. This allows us to perform a powerful singularity extraction and to replace the singular Green's kernel by a nonsingular truncated kernel, for which the moment integrals can be evaluated by means of numerical‐quadrature methods. Additionally, when utilizing a Galerkin pulse basis, a double Gauss theorem permits us to replace the 2n‐dimensional moment integral with a 2(n − 1)‐dimensional boundary integral, again offering dimensionality and computational gain. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 22–26, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21070
Hybrid packaging for a 1.25‐Gb/s bidirectional transceiver using a filter‐integrated planar lightwave circuit platform
Authors: Moon Sungwook , Han Sub , Choi Jung‐Ho , Shin Sang‐Gil , Ryu Gihan , Park Sung‐Woong , Song Sun‐Ho , Margalit Moti , Avni Eitan , Rogovsky Gideon 
Published: August 2005

AbstractA 1.25‐Gb/s bidirectional transceiver is designed and fabricated on a filter‐integrated PLC platform for access networks. The fabricated transceiver has optical output of 2.2 dBm at 30 mA and minimum sensitivity of −22.7 dBm at 10−12at a 1.25‐Gb/s NRZ signal and crosstalk penalty of 0.8 dB. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 34–36, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21073
Fully matched dual‐operation‐mode GaAs FET amplifier for efficiency enhancement at low‐power level
Authors: Chung Younkyu , Song Reem , Itoh Tatsuo 
Published: August 2005

AbstractThis paper presents a 2.12‐GHz GaAs FET dual‐operation‐mode amplifier with a new efficiency‐enhancing technique that employs novel switchable 1:1/1:0 ratio power‐routing schemes. The amplifier switches its operation, depending upon a required power level, to either a low‐power or high‐power mode. The integrated power routers enable all matching requirements in both modes to be satisfied regardless of the operating condition of the reference amplifiers. The measurement results show an improved efficiency performance in a low‐operation power range, as compared to a conventional balanced amplifier, due to the power‐routing schemes and demonstrated dual‐mode operation. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 41–44, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21075
NMR measurements of gaseous sulfur hexafluoride (SF6) to probe the cross‐linking of EPDM rubber
Authors: Terekhov M. , Neutzler S. , Aluas M. , Hoepfel D. , Oellrich L. R. 
Published: August 2005

AbstractThe effects of embedding gaseous SF6 into EPDM rubber were investigated using NMR methods. It was found that observed sorption and desorption processes follow the behavior of the dual mode sorption model. A strong correlation was found between EPDM cross‐linking and transversal relaxation time of embedded SF6. EPDM samples with different cross‐link densities, preliminarily determined by 1H transversal relaxation using the Gotlib model and Litvinov's method, were investigated using embedded SF6. The sensitivity of the 19F transversal relaxation rate of SF6 to the EPDM cross‐link density variation was found to be at least 10 times higher than for 1H in the polymer chain. First experiments on probing the swelling effects in EPDM due to its contact with polar liquids have been performed. Copyright © 2005 John Wiley & Sons, Ltd.
Resolution and reproducibility of BOLD and perfusion functional MRI at 3.0 Tesla
Authors: van Gelderen Peter , W.H. Wu Carolyn , de Zwart Jacco A. , Cohen Leonardo , Hallett Mark , Duyn Jeff H. 
Published: August 2005

AbstractVisual and somatosensory activation studies were performed on normal subjects to compare the spatial discrimination and reproducibility between functional MRI (fMRI) methods based on blood oxygen level‐dependent (BOLD) and perfusion contrast. To allow simultaneous measurement of BOLD and perfusion contrast, a dedicated MRI acquisition technique was developed. Repeated experiments of sensory stimulation of single digits of the right hand showed an average variability of activation amplitude of 25% for BOLD data, and a significantly lower variability of 21% for perfusion data. No significant difference in the variability of the locus of activity was observed between the BOLD and perfusion data. In somatotopy experiments, digits II and V were subjected to passive sensory stimulation. Both the BOLD and perfusion data showed substantial overlap in the activation patterns from the two digits. In a retinotopy study, two stimuli were alternated to excite different patches of V1. Again there was substantial overlap between the activation patterns from both stimuli, although the perfusion performed somewhat better than the BOLD method. Particularly for the visual studies, the overlap in activation patterns was more than expected based on the fine‐scale retinotopic mapping of cortical activity, suggesting that both BOLD and perfusion contrast mechanisms contribute substantially to the point‐spread function (PSF). Magn Reson Med, 2005. Published 2005 Wiley‐Liss, Inc.
Magnetic resonance imaging assessment of myocardial elastic modulus and viscosity using displacement imaging and phase‐contrast velocity mapping
Authors: Wen Han , Bennett Eric , Epstein Neal , Plehn Jonathan 
Published: August 2005

AbstractApproximately half of patients experiencing congestive heart failure present with a normal left ventricular ejection fraction. Perturbations in material properties affecting ventricular pressure/volume relationships likely play an important role in the “stiff heart syndrome” yet noninvasive tools permitting the accurate assessment of myocardial elasticity are extremely limited. We developed an MRI‐based technique to examine regional left ventricular stress/strain relationships by incorporating displacement‐encoding with stimulated‐echoes (DENSE) and phase‐contrast (PC) velocity mapping and compared regional elastic moduli (EM) and viscous delay time constants (VDTCs) (N = 10) with immediate postmortem direct strain gauge measurements (N = 8) and global chamber compliance (literature) in normal dogs. EMs by MRI were significantly greater in papillary muscle columns when compared with lateral wall and septal locations by MRI (7.59 ± 1.65 versus 3.40 ± 0.87 versus 2.55 ± 0.93 kPa, P < 0.0001) and were in agreement with direct strain gauge measurements (3.78 ± 0.93 and 2.96 ± 0.88 kPa for the lateral wall and the septum, P = ns for both versus MRI). MRI‐determined VDTCs were similar in the three regions (VDTC = −1.15 ± 12.37 versus 3.04 ± 7.25 versus 4.17 ± 5.76 ms, P = ns) and did not differ from lateral and septal wall strain gauge assessment (VDTC = 3.09 ± 0.40 and 4.57 ± 1.86 ms, P = ns for both versus MRI). Viscoelastic measurements obtained in six normal volunteers demonstrated the feasibility of this technique in humans. Noninvasive, regional assessment of myocardial stiffness using DENSE and PC velocity mapping techniques is accurate in a canine model and feasible in humans. Magn Reson Med, 2005. Published 2005 Wiley‐Liss, Inc.
Full‐brain T1 mapping through inversion recovery fast spin echo imaging with time‐efficient slice ordering
Authors: Zhu David C. , Penn Richard D. 
Published: August 2005

AbstractBrain T1 mapping has important clinical applications in detecting brain disorders. Conventional T1 mapping techniques are usually based on inversion recovery spin echo (IRSE) imaging or its more time‐efficient counterpart inversion recovery fast spin echo (IRFSE) imaging because they can deliver good image quality. Multiple inversion times are required to accurately estimate T1 over a wide range of values. Without acquisition optimization, both the IRSE and the IRFSE T1 mapping techniques require long scan times to image the whole brain. To reduce the scan time and maintain the quality of the T1 maps, we propose a new full‐brain T1 mapping pulse sequence based on a multislice inversion recovery fast spin echo imaging using a time‐efficient slice ordering technique. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Synthesis of well‐defined AB20‐type star polymers with cyclodextrin‐core by combination of NMP and ATRP
Authors: Miura Yutaka , Narumi Atsushi , Matsuya Soh , Satoh Toshifumi , Duan Qian , Kaga Harumi , Kakuchi Toyoji 
Published: August 2005

AbstractThe synthesis of an AB20‐type heteroarm star polymer consisting of a polystyrene arm and 20‐arms of poly(methyl methacrylate) or poly(tert‐butyl acrylate) was carried out using the combination of nitroxide‐mediated polymerization (NMP) and atom transfer radical polymerization (ATRP). The NMP of styrene was carried out using mono‐6‐[4‐(1′‐(2″,2″,6″,6″‐tetramethyl‐1″‐piperidinyloxy)‐ethyl)benzamido]‐β‐cyclodextrin peracetate (1) to afford end‐functionalized polystyrene with an acetylated β‐cyclodextrin (β‐CyD) unit (prepolymer 2) with a number‐average molecular weight (Mn) of 11700 and a polydispersity (Mw/Mn) of 1.17. After deacetylation of prepolymer 2, the resulting polymer was reacted with 2‐bromoisobutyric anhydride to give end‐functionalized polystyrene with 20(2‐bromoisobutyrol)s β‐CyD, macroinitiator 4. The copper (I)‐mediated ATRP of methyl methacrylate (MMA) and tert‐butyl acrylate (tBA) was carried out using macroinitiator 4. The resulting polymers were isolated by SEC fractionation to produce AB20‐type star polymers with a β‐CyD‐core, 5. The well‐defined structure of 5 with weight‐average molecular weight (Mw)s of 13,500–65,300 and Mw/Mn's of 1.26–1.28 was demonstrated by SEC and light scattering measurements. The arm polymers were separated from 5 by destruction with 28 wt % sodium methoxide in order to analyze the details of their characteristic structure. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4271–4279, 2005
Analysis of charge transient spectroscopy data originating from Gaussian densities of electron states in organics
Authors: Thurzo I. , Méndez H. , Zahn D. R. T. 
Published: August 2005

AbstractFor a large number of organic disordered semiconductors the transport of electrons or holes via hopping is mediated by localized states in the band gap. An attempt is presented towards testing the widely met hopping transport model based on the assumption of a Gaussian density of states (DOS). An analysis of both isothermal and thermal charge transient spectroscopy (QTS) response to recharging the Gaussian DOS by a sudden change in the applied bias (pulse) is presented. A three‐channel correlator is used for processing the exponential decay of transient charge Q(t) after the pulse: ΔQ = Q(t1) – 3/2Q(2t1) + 1/2Q(4t1), the response ΔQ peaking at the delay t1max ≈ τi, the latter quantity standing for the time constant of recharging the i‐th level of a discrete Gaussian spectrum of electron states. It is shown how the variances w of the isothermal ΔQ–log10(t1) spectrum and wT (in K) of a thermal ΔQ–T peak (T → temperature) are transformed to the variances in energy σ and σT, respectively. For the isothermal regime there is an analytical expression for the error of the transform due to the finite energy resolution of the ΔQ filter of time constants, however, the error in σT is to be assessed via simulation. Practical usage of the formalism is exemplified, taking QTS spectra of Ag/Dimethyl‐PTCDI/GaAs diodes as reference. The dominant peak (0.26 eV) is assigned to a dielectric relaxation, i.e. to charging the depletion layer capacitance of GaAs through the equivalent parallel resistance of the organic layer. In addition, QTS responses of metal/Alq3/indium‐tin‐oxide diodes are analysed, Alq3 being known as a prototypic disordered organic material with hopping transport of electrons via localized states in the band gap. In the latter case two processes have been envisaged, assigned to hopping of free charge carriers (signal tail at short times) and a distributed dielectric relaxation peak, respectively. This is to be compared with the case of locally ordered Alq3 layer on the same substrate, the QTS spectrum comprising three linear relaxation processes characterized by discrete time constants, while the signal tail pointing to the hopping transport being absent. The linear dependence of the peak heights on both the excitation pulse amplitude and polarity is suggestive of the presence of “dipolar” defects, envisaged as rotating polar molecules. The relative density of these (polarization) is peaking in the nitrogen‐rich Alq3 thin films. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identification of vacancy‐type defects in ZnTe using positron annihilation spectroscopy
Authors: Hamid A. S. , Shaban H. , Mansour B. A. , Uedono A. 
Published: August 2005

AbstractThe species of defects in Mg0.5Zn0.5Te, Li‐doped and P‐doped ZnTe samples were investigated by using positron‐based experiments. The positron lifetime experiments along with the atomic superposition (AT‐SUP) method were used to predict the positron trapping centers in the samples. The results of lifetime of positron were combined with the 2D angular correlation of annihilation radiation (ACAR) experiments to get information on the electronic structure of these defects. The momentum density distributions permitted the vacancy‐type defect to be distinguished in each sample. In addition, the results of the 2D‐ACAR experiments disclosed a relaxation of the atoms around the vacancy in the P‐doped ZnTe sample. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Erratum: E.A. Boudreaux and E. Baxter, “More QR‐SCMEH‐MO calculations on group VIB transition metal molecules, M2 (M = Cr, Mo, W, Sg) valence and valence‐core effects,” International Journal of Quantum Chemistry(2004) 100(6)1170–1178
Authors: Boudreaux E. A. , Baxter E. 
Published: August 2005

AbstractThe original article to which this Erratum refers was published in International Journal of Quantum Chemistry (2004) 100(6) 1170–1178.