bluuebunny/crossref_metadata_2025 huggingface dataset:
Floating Diamonds with Nanomagnetic Particles
Authors: Vatta Laura L.
Published: June 2005

In the diamond industry, ferrofluids are used in ferrohydrostatic separators for the density separation of diamonds from gangue material. The size of the magnetic core of the coated particles forming the ferrofluid suspension is vital in ensuring the stability of the fluid. The particle size must be small enough such that sedimentation does not occur in a magnetic field gradient and under the influence of a gravitational field and such that magnetic agglomeration can be overcome. This paper discusses the particle size requirements for fluid stability under the influence of these effects.
Templating Polymerization of Dodecylammonium Surfactants with Polymerizable (Meth)acrylate Counter Ions
Authors: Hartmann Patrice C. , Sanderson Ronald D.
Published: June 2005

Both dodecylammonium acrylate (I) and dodecylammonium methacrylate (II) are reactive surfactants in which the polymerizable group is the organic counterion. Templating polymerization of I and II from the lyotropic liquid crystalline (LLC) lamellar phase was successfully performed with conservation of the supramolecular structure. A 20 wt% aqueous solution of II formed cubic bicontinuous phases, even upon addition of divinyl benzene (DVB). Polymerization from the cubic phases was attempted without and with DVB (3 wt%). Bicontinuous cubic phases always evolved toward lamellar structures upon polymerization.
Comprehensive Study of Free Radical Copolymerization Using a Monte Carlo Simulation Method, 1
Authors: Mohammadi Yousef , Najafi Mohammad , Haddadi‐Asl Vahid
Published: June 2005

Summary: In order to investigate the influence of reactivity ratios and initial feed composition on the microstructure of macromolecules in free radical copolymerization, a comprehensive study was carried out using a Monte Carlo simulation method. As a result, a new procedure was introduced to modify the works of others on the initiation step. The variation of the copolymer composition and the fashion of the arrangement of monomers in simulated chains were evaluated as a function of copolymerization parameters. The model was capable of monitoring any change in azeotropy as well as the magnitude and direction of composition drift from the azeotrope point. The maximum reachable conversion (MRC) was predicted for different combinations of initial feed compositions and reactivity ratios. According to the simulation results, a critical conversion where the macromolecules produced inherited the maximum allowed alternation was obtained for the reactivity ratios given.

Change of sequence distribution of simulated copolymer chains with conversion for various initial feed compositions on a triangular graph (rA = 0.5, rB = 0.9).

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Change of sequence distribution of simulated copolymer chains with conversion for various initial feed compositions on a triangular graph (rA = 0.5, rB = 0.9).
Singularity‐Free Brownian Dynamics Analyses of Rotational Dynamics: Non‐Spherical Nanoparticles in Solution
Authors: Naess Stine Nalum , Elgsaeter Arnljot
Published: June 2005

Summary: From kinetic theory we have rigorously derived singularity‐free Brownian dynamics analyses of nanoparticle rotational dynamics. The rigid non‐spherical nanoparticles incorporate all three rotational degrees of freedom. This was achieved by using the components of Cartesian rotation vectors as the generalized coordinates describing angular orientation. The new results constitute an important advance compared to the situation when Eulerian angles specify angular orientation. Our finding eliminates one of the main longstanding obstacles to detailed studies of nanoparticle rotational dynamics in the diffusion time domain. The described formalism is applicable to a wide range of nanoparticle systems including liquid crystals, biopolymers, and colloids.

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Bernoullian, Terminal, Penultimate or Third Order Markov Statistics?
Authors: Karssenberg Frederik G. , Piel Christian , Hopf Andreas , Mathot Vincent B. F. , Kaminsky Walter
Published: June 2005

Summary: A series of 7 homogeneous ethylene‐propylene copolymers is modeled by a Bernoullian, a terminal, a penultimate and a third order Markov model and it is found that the penultimate model describes this series best. The Bernoullian and terminal model prove to be insufficient and the third order Markov model is statistically not justified. Based on these results, a criterion to select the optimal Markovian order of homogeneous, single site catalyst produced copolymers is developed.

Schematic of the [(3‐MePh)(4‐MePh)C(2,7‐di‐tert‐BuFlu)(Cp)]ZrCl2 metallocene copolymerizing ethene and propene.

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Schematic of the [(3‐MePh)(4‐MePh)C(2,7‐di‐tert‐BuFlu)(Cp)]ZrCl2 metallocene copolymerizing ethene and propene.
Molecular and cell biology of the sarcoglycan complex
Authors: Ozawa Eijiro , Mizuno Yuji , Hagiwara Yasuko , Sasaoka Toshikuni , Yoshida Mikiharu
Published: June 2005

The original sarcoglycan (SG) complex has four subunits and comprises a subcomplex of the dystrophin–dystrophin‐associated protein complex. Each SG gene has been shown to be responsible for limb‐girdle muscular dystrophy, called sarcoglycanopathy (SGP). In this review, we detail the characteristics of the SG subunits, and the mechanism of the formation of the SG complex and various molecules associated with this complex. We discuss the molecular mechanisms of SGP based on studies mostly using SGP animal models. In addition, we describe other SG molecules, ϵ‐ and ζ‐SGs, with special reference to their expression and roles in vascular smooth muscle, which are currently in dispute. We further consider the maternally imprinted nature of the ϵ‐SG gene. Finally, we stress that the SG complex cannot work by itself and works in a larger complex system, called the transverse fixation system, which forms an array of molecules responsible for various muscular dystrophies. Muscle Nerve, 2005
Serial electrophysiologic studies in rhesus monkeys with Krabbe disease
Authors: Weimer Maria B. , Gutierrez Amparo , Baskin Gary B. , Borda Juan T. , Veazey Ronald S. , Myers Leann , Phillippi‐Falkenstein Kathrine M. , Bunnell Bruce A. , Ratterree Marion S. , England John D.
Published: June 2005

Krabbe disease is a progressive leukodystrophy that results in demyelination in the central and peripheral nervous systems in humans. It has been described in a number of mammalian species including the rhesus monkey. We performed serial nerve conduction studies beginning within the first 2 months of life in four homozygous, two heterozygous, and two normal rhesus monkeys (Macaca mulatta) to characterize the peripheral neuropathy. Mean conduction velocities of the median, ulnar, and tibial nerves were significantly slower in the affected than unaffected monkeys at all ages (P < 0.0001). The conduction velocity differences became more apparent between the affected and unaffected as the monkeys aged. When compared to the unaffected monkeys, the serial conduction velocities suggested occurrence of dysmyelination followed by demyelination in the affected monkeys. These observations provide further insight into the disease process and suggest an early window of opportunity for treating Krabbe disease. Muscle Nerve, 2005
Chronic exercise accelerates the degeneration–regeneration cycle and downregulates insulin‐like growth factor‐1 in muscle of mdx mice
Authors: Okano T. , Yoshida K. , Nakamura A. , Sasazawa F. , Oide T. , Takeda S. , Ikeda S.
Published: June 2005

The aim of this study was to examine the effects of chronic running exercise on degenerative–regenerative processes in the hindlimb muscles of dystrophin‐deficient mdx mice. The number of large‐sized degenerative–regenerative groups (DRGs) was markedly decreased, whereas that of small‐sized DRGs was unchanged by exercise. Expression of insulin‐like growth factor‐1 (Igf1), as well as a myogenic factor MyoD (Myod1), was downregulated in mdx muscles by exercise. The downregulation of Igf1 may well correlate with the decrease in the population of early regenerating fibers, which existed predominantly in DRGs, because IGF‐1 was mainly localized in these fibers. Our data indicate that chronic exercise may accelerate the active cycle of degeneration–regeneration in mdx skeletal muscles. This means that mdx skeletal muscles can temporarily cope with work‐induced injury by enhancing muscle regeneration and repair, but we speculate that an early decline of IGF‐1 will accelerate age‐dependent muscle wasting and weakness in the later stage of life in mdx mice. Muscle Nerve, 2005
Effect of transcranial magnetic stimulation on voluntary activation in patients with quadriceps weakness
Authors: Urbach Dietmar , Berth Alexander , Awiszus Friedemann
Published: June 2005

Joint disease causes weakness and wasting of adjacent muscles, in part because of inability to fully activate these muscles voluntarily. Previous findings suggest that transcranial magnetic stimulation (TMS) paired with muscle contractions enhances maximal voluntary contraction force (MVC) in healthy subjects by improving voluntary activation (VA). The aim of the present study was to evaluate whether such an effect is also present in subjects suffering from diminished muscle force due to decreased VA. Three single TMS over resting motor threshold were applied in 10 patients with a mean age of 62 years after total‐knee arthroplasty either during MVC or during muscle relaxation (control experiment) in a blinded randomized crossover study. MVC and VA were determined using a twitch‐interpolation technique at 1, 15, 30, and 60 min after stimulation. There was a significant effect of TMS on MVC if applied in synchrony with muscle contraction, and this persisted for at least 60 min beyond stimulation. In patients suffering from joint disease, TMS might make physiotherapy more effective. Muscle Nerve, 2005
Pain ratings at the thresholds are necessary for interpretation of quantitative sensory testing
Authors: Kelly Kiesa Getz , Cook Thomas , Backonja Misha‐Miroslav
Published: June 2005

Published databases of quantitative sensory testing (QST) for sensory thresholds provide a means for detecting deficits of the thermonociceptive sensory nervous system. These databases, however, do not assist in the assessment of neuropathic pain, which is characterized by pain or hyperalgesia, or both. We utilized the method of levels for innocuous thermal stimuli, warm and cool, and the method of limits for noxious thermal stimuli, hot pain and cold pain, to determine QST thresholds. Stimuli were applied to distal and proximal sites in the upper and lower limbs of 50 healthy volunteers, ranging in age from 19 to 59 years. Thresholds for innocuous and noxious stimuli in this study were similar to previously published results. The mean pain rating across all sites at thresholds for noxious heat and cold stimuli was 4.10, as rated on a 0–10 numeric scale. Suggestions are provided for combining threshold information for innocuous and noxious stimuli and related pain ratings for the evaluation of sensory nervous system function and, specifically, neuropathic pain. © 2005 Wiley Periodicals, Inc. Muscle Nerve, 2005
Hypercholesterolemia as a risk factor for idiopathic carpal tunnel syndrome
Authors: Nakamichi Ken‐Ichi , Tachibana Shintaro
Published: June 2005

In idiopathic carpal tunnel syndrome (CTS), the median nerve is enlarged within the carpal tunnel due to intraneural connective tissue proliferation. Because hypercholesterolemia, especially increase in low‐density lipoprotein (LDL), has been associated with fibrogenesis, we investigated the association of median nerve cross‐sectional area and prevalence of idiopathic CTS with serum lipid measurements in middle‐aged patients and controls. We found that nerve area and prevalence of CTS were correlated with serum LDL levels. Thus, high LDL levels in middle age are a risk factor for idiopathic CTS, suggesting that the LDL‐correlated median nerve enlargement increases the volume of the carpal tunnel contents. Muscle Nerve, 2005
Minimum principle and related numerical scheme for simulating initial flow and subsequent propagation of liquefied ground
Authors: Montassar Sami , de Buhan Patrick
Published: June 2005

The problem of predicting the evolution of liquefied ground, modelled as a viscoplastic material, is addressed by combining a minimum principle for the velocity field, which characterizes such an evolution, and a time step integration procedure. Two different numerical schemes are then presented for the finite element implementation of this minimum principle, namely, the regularization technique and the decomposition‐co‐ordination method by augmented Lagrangian. The second method, which proves more accurate and efficient than the first, is finally applied to simulate the incipient flow failure and subsequent spreading of a liquefied soil embankment subject to gravity. The strong influence of liquefied soil residual shear strength on reducing the maximum amplitude of the ground displacement is particularly emphasized in such an analysis. Copyright © 2005 John Wiley & Sons, Ltd.
Modelling chemo‐hydro‐mechanical behaviour of unsaturated clays: a feasibility study
Authors: Liu Z. , Boukpeti N. , Li X. , Collin F. , Radu J.‐P. , Hueckel T. , Charlier R.
Published: June 2005

Effective capabilities of combined chemo‐elasto‐plastic and unsaturated soil models to simulate chemo‐hydro‐mechanical (CHM) behaviour of clays are examined in numerical simulations through selected boundary value problems. The objective is to investigate the feasibility of approaching such complex material behaviour numerically by combining two existing models. The chemo‐mechanical effects are described using the concept of chemical softening consisting of reduction of the pre‐consolidation pressure proposed originally by Hueckel (Can. Geotech. J. 1992; 29:1071–1086; Int. J. Numer. Anal. Methods Geomech. 1997; 21:43–72). An additional chemical softening mechanism is considered, consisting in a decrease of cohesion with an increase in contaminant concentration. The influence of partial saturation on the constitutive behaviour is modelled following Barcelona basic model (BBM) formulation (Géotech. 1990; 40(3):405–430; Can. Geotech. J. 1992; 29:1013–1032).

The equilibrium equations combined with the CHM constitutive relations, and the governing equations for flow of fluids and contaminant transport, are solved numerically using finite element. The emphasis is laid on understanding the role that the individual chemical effects such as chemo‐elastic swelling, or chemo‐plastic consolidation, or finally, chemical loss of cohesion have in the overall response of the soil mass. The numerical problems analysed concern the chemical effects in response to wetting of a clay specimen with an organic liquid in rigid wall consolidometer, during biaxial loading up to failure, and in response to fresh water influx during tunnel excavation in swelling clay. Copyright © 2005 John Wiley & Sons, Ltd.
A viscoplastic model including anisotropic damage for the time dependent behaviour of rock
Authors: Pellet F. , Hajdu A. , Deleruyelle F. , Besnus F.
Published: June 2005

This paper presents a new constitutive model for the time dependent mechanical behaviour of rock which takes into account both viscoplastic behaviour and evolution of damage with respect to time. This model is built by associating a viscoplastic constitutive law to the damage theory. The main characteristics of this model are the account of a viscoplastic volumetric strain (i.e. contractancy and dilatancy) as well as the anisotropy of damage. The latter is described by a second rank tensor. Using this model, it is possible to predict delayed rupture by determining time to failure, in creep tests for example. The identification of the model parameters is based on experiments such as creep tests, relaxation tests and quasi‐static tests. The physical meaning of these parameters is discussed and comparisons with lab tests are presented. The ability of the model to reproduce the delayed failure observed in tertiary creep is demonstrated as well as the sensitivity of the mechanical response to the rate of loading. The model could be used to simulate the evolution of the excavated damage zone around underground openings. Copyright © 2005 John Wiley & Sons, Ltd.
Scattering of elastic wave by a partially sealed cylindrical shell embedded in poroelastic medium
Authors: Gan‐Bin Liu , Kang‐He Xie , Hai‐lin Yao
Published: June 2005

Scattering of an elastic wave by a cylindrical shell embedded in poroelastic medium is investigated theoretically with the assumption that the shell material is also a porous elastic medium. The porous medium is modellized via Biot's theory and the scattering by cylindrical shell is expressed by the definition of scattering matrix. The normal mode expansion technique is employed for analysing the scattering field, and the asymptotic solutions of displacements, stresses and pore pressure are derived. Two limiting cases‐scattering by a poroelastic cylinder in Biot medium and a elastic cylindrical shell in elastic medium are obtained from the general solutions. The dispersion curves of displacement amplitude at the interface of shell and medium is compared with the case of elastic shell. The scattering amplitude associated with the fast, slow and transverse waves are identified by numerical simulation. Furthermore, the influence of the poroelastic property of shell material on scattering amplitude is analysed. Copyright © 2005 John Wiley & Sons, Ltd.
Compatibilization of polystyrene/poly(butyl methacrylate)/poly[(ethylene glycol) dimethacrylate] blends via concentrated emulsion polymerization
Authors: Du Zhongjie , Zhang Chen , Li Hangquan
Published: June 2005

Two concentrated emulsions in water containing styrene and butyl methacrylate (BMA) as dispersed phases were prepared. Each of them contained a small amount of an amphiphilic macromonomer, poly[(ethylene glycol) dimethacrylate] (PEGD), in the continuous phase. The two concentrated emulsions were partially polymerized at 50 °C until conversions of about 22.5 % were reached. They were then mixed mechanically and the mixture was subjected to complete polymerization. During the latter polymerization, homopolymers of styrene and BMA and copolymers of the two were generated. The copolymers, particularly the crosslinked structures, which were formed through copolymerization of PEGD with styrene and BMA at the interface of the latexes, provided compatibilizers for the homopolymers. This blend of homopolymers, copolymers and crosslinked structures possessed excellent toughness and processability. The blends were characterized by their gel content, and by X‐ray photoelectron spectroscopy, rheometric testing, dynamic mechanical thermal analysis, transmission electron microscopy and impact strength measurements. Copyright © 2005 Society of Chemical Industry
De novo sequence analysis of N‐terminal sulfonated peptides after in‐gel guanidination
Authors: Sergeant Kjell , Samyn Bart , Debyser Griet , Van Beeumen Jozef
Published: June 2005

Here we report a novel approach in which gel‐separated proteins are guanidinated in‐gel prior to enzymatic cleavage. In contrast to previously described techniques, this procedure allows the extracted tryptic peptides to be N‐terminal sulfonated without any further sample purification. The derivatized peptides were subsequently fragmented using a matrix‐assisted laser desorption/ionization time of flight/time of flight instrument. The approach facilitates the de novo sequence analysis and allows obtaining longer stretches of amino acid sequence information. We demonstrate that the obtained information can be used to identify proteins using a sequence similarity search algorithm. The technique was compared to the standard peptide mass fingerprint approach, applied either in‐gel or in solution, using a number of sodium dodecyl sulfate‐polyacrylamide gel electrophoresis separated model proteins. Finally, the new protocol was applied on a proteomic study of two‐dimensional PAGE separated proteins from Shewanella oneidensis. More than 50 proteins from this organism were identified using sub‐picomol quantities of protein, and peptide sequences of up to 20 amino acid residues in length have been determined.
Editorial: Proteomics 9/2005
Authors: Dunn Michael J.
Published: June 2005

No abstracts.
A “de‐streaking” method for two‐dimensional electrophoresis using the reducing agent tris(2‐carboxyethyl)‐phosphine hydrochloride and alkylating agent vinylpyridine
Authors: Bai Fengju , Liu Sheng , Witzmann Frank A.
Published: June 2005

See original http://dx.doi.org/10.1002/pmic.200501291
Directly copolymerized poly(arylene sulfide sulfone) disulfonated copolymers for PEM‐based fuel cell systems. I. Synthesis and characterization
Authors: Wiles K. B. , Wang F. , McGrath J. E.
Published: June 2005

Direct aromatic nucleophilic substitution polycondensations of disodium 3,3′‐disulfonate‐4,4′‐difluorodiphenylsulfone (SDFDPS), 4,4′‐difluorodiphenylsulfone (DFDPS) (or their chlorinated analogs), and 4,4′‐thiobisbenzenethiol in the presence of potassium carbonate were investigated. Electrophilic aromatic substitution was employed to synthesize the SDFDPS comonomer in high yields and purity. High molecular weight disulfonated copolymers were easily obtained using the SDFDPS monomers, but in general, slower rates and a lower molecular weight copolymer were obtained using the analogous chlorinated monomers. Tough and ductile membranes were solution cast from N,N‐dimethylacetamide for both series of copolymers. The degrees of disulfonation (20–50%) were controlled by varying the ratio of disulfonated to unsulfonated comonomers. Precise control of the ionic concentration, well‐defined ionic locations, and enhanced stability due to the deactivated position of the –SO3H group are some of the suggested advantages of direct copolymerization of sulfonated monomers. Further publications will discuss additional characteristics of these copolymers that have the same repeat unit, but different molecular weights, using methanol permeability, water uptake, protonic conductivity, and dynamic mechanical analysis. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2964‐2976, 2005
Preparation of poly(ethylene oxide)‐block‐poly(isoprene) by nitroxide‐mediated free radical polymerization from PEO macroinitiators
Authors: Wegrzyn Jakub K. , Stephan Tim , Lau Ryan , Grubbs Robert B.
Published: June 2005

Amphiphilic poly(ethylene oxide)‐block‐poly(isoprene) (PEO‐b‐PI) diblock copolymers were prepared by nitroxide‐mediated polymerization of isoprene from alkoxyamine‐terminal poly(ethylene oxide) (PEO). PEO monomethyl ether (Mn ≈ 5200 g/mol) was functionalized by esterification with 2‐bromopropionyl bromide with subsequent copper‐mediated replacement of the terminal bromine with 2,2,5‐trimethyl‐4‐phenyl‐3‐azahexane‐3‐nitroxide. The resulting PEO‐alkoxyamine macroinitiator was used to initiate polymerization of isoprene in bulk and in solution at 125 °C to yield PEO‐b‐PI block copolymers with narrow molecular weight distributions (Mw/Mn ≤ 1.1). Polymerizations were first order in isoprene through 35% conversion. Micellar aggregates of PEO‐b‐PI in aqueous solution were crosslinked by treatment with a water‐soluble redox initiating system, and persistent micellar structures were observed in the dry state by AFM. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2977–2984, 2005
Synthesis and characterization of organosoluble ditrifluoromethylated aromatic polyimides
Authors: Liu Baijun , Hu Wei , Matsumoto Toshihiko , Jiang Zhenhua , Ando Shinji
Published: June 2005

Two novel diamine monomers, 1,4‐bis (4‐aminophenoxy)‐2‐[(3′,5′‐ditrifluoromethyl)phenyl]benzene and 1,4‐bis [2′‐cyano‐3′(4″‐amino phenoxy)phenoxy]‐2‐[(3′,5′‐ditrifluoromethyl)phenyl] benzene, were synthesized from (3,5‐ditrifluoromethyl)phenylhydroquinone. A series of ditrifluoromethylated aromatic polyimides derived from the diamines were prepared through a typical two‐step polymerization method. These polyimides had a high thermal stability, and the temperatures at 10% weight loss were above 507 °C in nitrogen. Most of the polymers showed good solubility in anhydrated 1‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, N,N‐dimethylformamide, chloroform, and tetrahydrofuran at room temperature. All the polymers formed transparent, strong, and flexible films with tensile strengths of 63.6–95.8 MPa, elongations at break of 5–10%, and Young's moduli of 2.38–2.96 GPa. The dielectric constants estimated from the average refractive indices are 2.69–2.89. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3018–3029, 2005
Synthesis of poly(isobutyl‐co‐2,2,2‐trifluoroethyl methacrylate) with 5,10,15,20‐tetraphenylporphinato platinum(II) moiety as an oxygen‐sensing dye for pressure‐sensitive paint
Authors: Obata Makoto , Tanaka Yurie , Araki Naoko , Hirohara Shiho , Yano Shigenobu , Mitsuo Kazunori , Asai Keisuke , Harada Masafumi , Kakuchi Toyoji , Ohtsuki Chikara
Published: June 2005

Pressure‐sensitive paint (PSP), which consists of luminescent molecules embedded in an oxygen‐permeable polymer, has been developed for use in wind‐tunnel experiments. To improve the PSP technique, a novel luminescent methacrylate monomer, 5‐[4‐(2‐methacryloyloxyethoxycarbonyl)phenyl]‐10,15,20‐triphenylporphinato platinum(II), was synthesized and copolymerized with isobutyl methacrylate and 2,2,2‐trifluoroethyl methacrylate to produce a dye‐pendant copolymer (2). The introduction of 5,10,15,20‐tetraphenylporphinato platinum(II) (PtTPP) dye into 2 was confirmed by ultraviolet–visible spectroscopy and extended X‐ray absorption fine structure measurements. The extent of PtTPP dye incorporation in 2 was proportional to the molar fraction of the PtTPP‐pendant methacrylate monomer in the feed. The oxygen‐sensing property of 2 was compared with that of a PSP consisting of PtTPP dye embedded in poly(isobutyl‐co‐2,2,2‐trifluoroethyl methacrylate). Although the simple mixture of PtTPP and poly(isobutyl‐co‐2,2,2‐trifluoroethyl methacrylate) showed a marked deviation from a single Stern–Volmer relation, novel copolymer 2 gave a highly linear Stern–Volmer plot. This was unequivocal evidence of dye conjugation on the oxygen‐sensing polymer film. © 2005Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2997–3006, 2005
Pt‐catalyzed chemical modification of α,ω‐bis(hydrido)polydimethylsiloxanes and copoly(methylhydridosiloxane/dimethylsiloxane) with vinylheptaphenylcyclotetrasiloxane
Authors: Gädda Thomas M. , Weber William P.
Published: June 2005

Pt‐catalyzed hydrosilylation between vinylheptaphenylcyclotetrasiloxane and a series of α,ω‐bis(hydrido)polydimethylsiloxanes and copoly(methylhydridosiloxane/dimethylsiloxane) was used to prepare chemically modified materials. These modified polymers were characterized by IR, UV, and 1H, 13C, and 29Si NMR spectroscopy and gel permeation chromatography (GPC). The molecular weights, determined by GPC, UV, and NMR end‐group analysis, showed the anticipated increases. The thermal properties of the polymers were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The crystallinity, determined by DSC, was either reduced or completely eliminated for the modified polymers. The thermal stabilities, measured in both air and nitrogen by TGA, were slightly higher than the thermal stability of α,ω‐bis(trimethylsiloxy)polydimethylsiloxane. Significantly increased bulk viscosities were observed for all the modified polymers. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3007‐3017, 2005
Preparation and characterization of the chromatographic properties of ethylene glycol dimethacrylate/divinylbenzene polymeric microspheres
Authors: Maciejewska Małgorzata , Osypiuk Joanna , Gawdzik Barbara
Published: June 2005

The preparation of porous ethylene glycol dimethacrylate/divinylbenzene polymeric microspheres is presented. These materials were investigated as column packings for high‐performance liquid chromatography. Their porous structures in both the dry and wet states were also studied. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3049–3058, 2005
Synthesis of carbohydrate‐linked poly(polyoxometalate) poly(amido)amine dendrimers
Authors: Morgan Joel R. , Cloninger Mary J.
Published: June 2005

Mannose‐functionalized and ethoxyethanol‐functionalized poly(amido)amine dendrimers bound multiple vanadate‐substituted polyoxotungstate Wells–Dawson‐type polyoxometalates (POMs). Dendrimers incorporating 10–30 POMs were characterized with NMR, transmission electron microscopy, and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry techniques. The number of metal clusters per dendrimer molecule varied according to the dendrimer generation and the nature of the surface functional groups. Efforts aimed at using the poly(polyoxometalate) dendrimers as oxidation catalysts are also described. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3059–3066, 2005
Kinetically controlled phase transitions in liquid‐crystalline polymers. II. Isothermal degradation of ferroelectric switching in a chiral side‐chain polysiloxane during slow smectic B phase formation
Authors: Kozlovsky Mikhail , Skarp Kent
Published: June 2005

The kinetics of phase transformations in a chiral siloxane polymer has been studied with an Avrami analysis of the differential scanning calorimetry data. Ferroelectric switching has been measured as a function of the driving voltage and temperature. The evolution of the switching at a constant temperature has been studied within the temperature range of the kinetically governed smectic C*/smectic B phase transition. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1779–1784, 2005
Viscoelastic characterization of polymers using instrumented indentation. II. Dynamic testing*
Authors: White C. C. , VanLandingham M. R. , Drzal P. L. , Chang N.‐K. , Chang S.‐H.
Published: June 2005

Dynamic nanoindentation was performed on a cured epoxy, a poly(methyl methacrylate) (PMMA), and two poly(dimethyl siloxane) (PDMS) samples of different crosslink densities. These samples were used to compare dynamic nanoindentation with classical rheological measurements on polymeric samples in the glassy and rubbery plateau regions. Excellent agreement between bulk rheological data and dynamic nanoindentation data was observed for the two glassy materials (epoxy and PMMA) and the less compliant PDMS sample. More divergent results were observed for the more compliant PDMS sample. The theoretical foundation and historical development of the working equations for these two types of instrumentation are presented and discussed. The major difference between nanoindentation and the more classical rheological results is in the treatment of the instrument–sample interface. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1812–1824, 2005
Morphology and elastic modulus of novel poly[oligo(ethylene glycol) diacrylate]‐montmorillonite nanocomposites
Authors: Chen Biqiong , Bowden Allen A. , Greenwell H. Chris , Boulet Pascal , Coveney Peter V. , Whiting Andrew , Evans Julian R. G.
Published: June 2005

Novel thermosetting poly[oligo(ethylene glycol) diacrylate]‐sodium montmorillonite nanocomposites containing a range of clay volume fractions were prepared by an in situ polymerization method. X‐ray diffraction showed that the basal plane spacing of the clay was increased to approximately 1.7 nm regardless of clay volume fraction. Transmission electron microscopy confirmed the basal spacing and intercalated structure. The elastic moduli of the composites were measured using ultrasonic pulse‐echo equipment. The results show that the Young's modulus and shear modulus increase with nominal clay volume fraction up to 0.22, and are in good agreement with the well‐established Christensen method and derived Hashin–Shtrikman bounds for conventional composites provided that the true volume fraction of clay reinforcement filler is calculated. At low clay volume fractions, the composites were transparent. When the nominal clay volume fraction was further increased, cracks and porous surfaces appeared, as observed by scanning electron microscopy. These defects decreased the elastic modulus, indicating an upper limit for clay additions in this preparation route. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1785–1793, 2005
Numerical Calculation of London‐van der Waals Adhesion Force Distributions for Different Superquadric Shaped Particles
Authors: Sonnenberg Jost‐Peter , Schmidt Eberhard
Published: June 2005

The macroscopic behavior of dry submicron particle systems, for example the flowability, the agglomeration behavior and the dispersing properties, is influenced decisively by the London‐van der Waals dispersion force. Knowledge of expectable interparticular dispersion forces could be useful to characterize applications in practice, regarding e.g. process parameters, product quality, environmental and industrial safety. In this paper a basic method for forecasting interparticular dispersion forces is introduced. One method to obtain information about the dispersion forces is to start by analyzing a single particle of a given shape in a certain system, and consider the particle‐wall system for which the dispersion force distribution is calculated. The distribution describes the resulting calculated adhesive forces when pairing the particle with a semi‐infinite wall surface in all of the possible positions, assuming a constant surface distance is maintained. Additionally, it is shown that the knowledge of the particle projection screen shape in many cases is sufficient to calculate the force distribution for the associated 3D particle. Thereby, calculation of the dispersion forces for moderate sized (radius < 30 nm) two‐ and three‐dimensional particles represents no great difficulty, but rather the challenge is the allocation of the 2D to the 3D data. The aim is to reduce the time and effort spent on calculation in order to establish a basis for later dispersion force calculations of bigger particles and particle collectives.
The Wall Stresses and Insert Load in a Two‐Dimensional Flat‐bottomed Bin with an Equilateral Triangle Insert
Authors: Chou Chuen‐Shii , Tseng Chun‐Yuan
Published: June 2005

The wall stresses and insert load in a two‐dimensional flat‐bottomed bin with a flow corrective insert were investigated. The static wall stress distributions produced by the granular solids were measured and compared with the theoretical prediction using the differential slice method. The variations in the dynamic wall stresses and the dynamic response of the insert load with time were obtained. The comparison of the experimental insert load to the theoretical prediction was demonstrated. In addition, the effect of the flow corrective insert upon the wall stress and insert load was investigated. As the insert half‐angle increases, the effect of disrupting the contact force network above the insert decreases, and the insert load produced by the granular solids increases. Employing the results obtained using stress measurements, the pulsation phenomena of wall stress and insert load in a bin with a triangle flow corrective insert may be further understood.
Expansions in Free Space of Arbitrary Quantum Wavepackets, Quantum Laser Beams, and Gaussian Quantum (On‐axis and Off‐axis) Laser Beams in Terms of Free Spherical Waves
Authors: Gouesbet Gérard
Published: June 2005

Electromagnetic generalized Lorenz‐Mie Theory (GLMT) describes the interaction between an arbitrary shaped electromagnetic laser beam and a homogeneous sphere, with an isotropic and linear material. We are interested in the study of analogies and differences between the electromagnetic GLMT and a quantum GLMT, and to their exploitation. To build a quantum GLMT, a prerequisite is the description of the incident quantum state in terms of spherical partial waves. In this framework, this paper deals with the expansions in free space of arbitrary quantum wave packets, quantum laser beams, and quantum Gaussian (on‐axis and off‐axis) laser beams in terms of free spherical waves.
Shape and Size Determination by Laser Diffraction: Average Aspect Ratio and Size Distributions by Volume; Feasibility of Data Analysis by Neural Networks
Authors: Deriemaeker Luc , Finsy Robert
Published: June 2005

A new strategy for the recovery of the average shape factor and the volume weighted size distribution from laser diffraction data using neural networks is presented. The method yields reliable estimates for both the shape factor and the volume weighted size distribution.
Statistical and molecular dynamics studies of buried waters in globular proteins
Authors: Park Sheldon , Saven Jeffery G.
Published: June 2005

Buried solvent molecules are common in the core of globular proteins and contribute to structural stability. Folding necessitates the burial of polar backbone atoms in the protein core, whose hydrogen‐bonding capacities should be satisfied on average. Whereas the residues in α‐helices and β‐sheets form systematic main‐chain hydrogen bonds, the residues in turns, coils and loops often contain polar atoms that fail to form intramolecular hydrogen bonds. The statistical analysis of 842 high resolution protein structures shows that well‐resolved, internal water molecules preferentially reside near residues without α‐helical and β‐sheet secondary structures. These buried waters most often form primary hydrogen bonds to main‐chain atoms not involved in intramolecular hydrogen bonds, providing strong evidence that hydrating main‐chain atoms is a key structural role of buried water molecules. Additionally, the average B‐factor of protein atoms hydrogen‐bonded to waters is smaller than that of protein atoms forming intramolecular hydrogen bonds, and the average B‐factor of water molecules involved in primary hydrogen bonds with main‐chain atoms is smaller than the average B‐factor of water molecules involved in secondary hydrogen bonds to protein atoms that form concurrent intramolecular hydrogen bonds. To study the structural coupling between internal waters and buried polar atoms in detail we simulated the dynamics of wild‐type FKBP12, in which a buried water, Wat137, forms one side‐chain and multiple main‐chain hydrogen bonds. We mutated E60, whose side‐chain hydrogen bonds with Wat137, to Q, N, S or A, to modulate the multiplicity and geometry of hydrogen bonds to the water. Mutating E60 to a residue that is unable to form a hydrogen bond with Wat137 results in reorientation of the water molecule and leads to a structural readjustment of residues that are both near and distant to the water. We predict that the E60A mutation will result in a significantly reduced affinity of FKBP12 for its ligand FK506. The propensity of internal waters to hydrogen bond to buried polar atoms suggests that ordered water molecules may constitute fundamental structural components of proteins, particularly in regions where α‐helical or β‐sheet secondary structure is not present. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Impact of maize mucilage on atrazine mineralization and atzC abundance
Authors: López‐Gutiérrez Juan C , Philippot Laurent , Martin‐Laurent Fabrice
Published: June 2005

Soil was amended with maize mucilage, a major rhizodeposit, to study its role on the number of culturable soil micro‐organisms, the structure of the bacterial community, atrazine mineralization and atzC abundance. The maximal percentage of atrazine mineralization was lower for mucilage‐amended than for water‐amended soil. Total culturable soil bacteria and 16S rDNA copy number, measured by RT‐PCR, presented similar values and were not significantly (P < 0.05) different among treatments. Mucilage applied at a rate of 70 µg C g−1 dry soil day−1 over two weeks did not modify the abundance of the total soil microflora. Global structure of soil bacterial communities revealed by RISA analysis was not modified by maize mucilage amendment. Abundance of atzC sequence was only augmented by mucilage addition at the beginning of the experiment. However, this increase was not sustainable in time, as atzC copy number increased in water‐amended soil which, in turn, corresponded with the higher percentage of atrazine mineralization observed in this soil. Maize mucilage amendment alone contributed only to minor changes in the atrazine‐degrading community in the studied soil. Copyright © 2005 Society of Chemical Industry
Parametric amplification and polariton liquids in semiconductor microcavities
Authors: Baumberg Jeremy J. , Lagoudakis Pavlos G.
Published: June 2005

Parametric amplification in semiconductor microcavities provides an example in which nonlinear optical interactions produced by the exchange interaction of excitons become so large that multiple scattering of polaritons becomes important. Here we review time‐resolved observations of the polariton interactions in a number of different geometries including pumping at either the magic angle, or the bottom of the polariton trap. Situations in which the polariton dispersion is multiply occupied by large populations give rise to k‐dependent energy shifts, modifying the dispersion dynamically, a situation we term the strongly‐interacting ‘polariton liquid’. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Safe sites for establishment of Nymphoides peltata seedlings for recovering the population from the soil seed bank
Authors: Takagawa Shinichi , Nishihiro Jun , Washitani Izumi
Published: June 2005

The population of the endangered plant species Nymphoides peltata in Lake Kasumigaura, Japan, has been declining drastically recently, and seedlings that emerge from the remaining soil seed bank have entirely failed to establish. The decline has followed artificial control of the water level in the lake. To examine the environmental requirements at the seedling establishment stage, we investigated the survival and growth of emerged seedlings at various microsites on the lakeshore by manipulating environmental conditions such as exposure to waves, inundation, and light availability so as to include the conditions of the presumed safe sites. Seedling survival at the early stage was affected most by environmental variables relating to the susceptibility to inundation. Survival until seedling establishment was profoundly affected by light availability as well as by susceptibility to inundation. In all, 136 genets were established in quadrats less prone to inundation and with sufficient light availability, which is consistent with the presumed safe‐site characteristics of the original water regime: bare ground exposed during the spring water‐level drawdown. Recovering the original water regime with seasonal drawdown will be indispensable for recovering a self‐sustainable population. However, as first‐aid measures, active restoration efforts through adaptive management using the remnant soil seed bank are urgently needed before the soil seed bank becomes exhausted.
Molecular cloning, expression profile and functional implications of clusterin in the pituitary gland of helmeted guinea fowl (Numida meleagris)
Authors: Claudius Luziga , Yoshimi Yamamoto , Yoichiro Horii , Rudovick Kazwala , Koichi Mamba
Published: June 2005

Clusterin is shown to contain putative amphipathic α‐helices that mediate hydrophobic interactions with numerous types of molecules and may be involved in clearance of cellular debris caused by cell injury or death. To assess this function in vivo, we have cloned the full‐length cDNA encoding guinea fowl (Numida meleagris) clusterin and studied its synthesis and expression pattern in specific cell types in pituitary. Quantity of clusterin mRNA expressed in pituitary and endocrine tissues was quantified by real‐time PCR. Highest levels were detected in gonads. In situ hybridization showed clusterin mRNA in endocrine cells and folliculostellate cells. Clusterin protein detected by immunohistochemistry was observed in endocrine cells, folliculostellate cells and in colloid. The expression pattern suggests that clusterin is produced by endocrine cells for cytoprotection. Degenerating endocrine cells are phagocytosed by folliculostellate cells and digested by their lysosomal enzymes. In folliculostellate cells clusterin interacts and aggregates with by‐products of digestion that subsequently become stored in colloid.
Chemopreventive activities of Trigonella foenum graecum (Fenugreek) against breast cancer
Authors: Amin Amr , Alkaabi Aysha , Al‐Falasi Shamaa , Daoud Sayel A.
Published: June 2005

Cancer is the second leading cause of death worldwide. Conventional therapies cause serious side effects and, at best, merely extend the patient's lifespan by a few years. Cancer control may therefore benefit from the potential that resides in alternative therapies. There is thus an increasing demand to utilize alternative concepts or approaches to the prevention of cancer. In this report, we show a potential protective effect of Fenugreek seeds against 7,12‐dimethylbenz(α)anthracene (DMBA)‐induced breast cancer in rats. At 200 mg/kg b.wt., Fenugreek seeds' extract significantly inhibited the DMBA‐induced mammary hyperplasia and decreased its incidence. Epidemiological studies also implicate apoptosis as a mechanism that might mediate the Fenugreek's anti‐breast cancer protective effects. To our knowledge, this is the first study that suggests significant chemopreventive effects of Fenugreek seeds against breast cancer.
Sleep Disturbances in Patients with Chronic Heart Failure and Their Holistic Consequences—What Different Care Actions can be Implemented?
Authors: Broström Anders , Johansson Peter
Published: June 2005

Background: Sleep disturbances are prevalent among elderly, especially among those with chronic heart failure (CHF) and can affect all dimensions of quality of life (QOL) negatively.

Aim: To describe the most common causes leading to sleep disturbances in patients with CHF, their consequences from a holistic perspective and different care actions that can be implemented.

Methods: MEDLINE and CINAHL databases were searched from 1989 to July 2004.

Findings: Sleep disordered breathing (SDB), and insomnia were the most common causes for sleep disturbances and occurs in 45–82% (SDB) and one-third (insomnia) of all patients with CHF. SDB cause a disturbed sleep structure with frequent awakenings, as well as several adverse effects on the cardiovascular system causing increased morbidity and mortality. Insomnia, caused by anxiety, an unknown life situation in relation to the debut of CHF, or symptoms/deteriorations of CHF can lead to negative effects on all aspects of QOL, as well as daytime sleepiness.

Conclusion: The high prevalence of sleep disturbances and their holistic consequences should be taken into account when nurses asses and plan the care for patients with CHF. Randomized studies with large sample sizes evaluating non-pharmacological nursing interventions that improve sleep are needed.