bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of the prediction efficiency of two pedotransfer functions for soil cation‐exchange capacity
Authors: Horn Andreas L. , Düring Rolf‐Alexander , Gäth Stefan
Published: June 2005

The aim of this study was to provide knowledge of the prediction efficiency of two pedotransfer functions for soil cation‐exchange capacity (CEC), i.e., the approaches of Krogh et al. (2000) and Scheinost (1995). Potential CEC, i.e., CEC at pH 8.1, was predicted for 30 samples of German soils showing a strong variation of soil organic C and clay content which are important soil characteristics for CEC. The results were compared to analyzed potential CEC of the samples by coefficient‐of‐efficiency (EC) criterion of Nash and Sutcliffe (1970). Significant deviations between observed and measured CEC were found for both functions. The approach of Scheinost (1995) showed a higher prediction efficiency (EC = 0.77 in comparison to EC = 0.26 for Krogh et al., 2000) and better results under extrapolative conditions.
Modeling aluminum solubility in intrazonal podzols using WHAM‐S/Model V
Authors: Jansen Boris , Mulder Jan , Verstraten Jacobus M.
Published: June 2005

So far, research in the area of podzolization has not resulted in consensus about the role of organic matter (OM) in regulating the transport and accumulation of Al and Fe at depth. From previous laboratory studies of the role of OM as a driver for podzolization in two intrazonal podzols, we concluded that it controls the mobilization of Al and Fe in A horizons and regulates the immobilization of Al in upper B horizons. In contrast, the solubility of Al in lower B horizons is mainly regulated by equilibrium with its secondary inorganic phases, as is the case for Fe in all B horizons. In the present study, we tested the conclusions with respect to Al through the application of the comprehensive metal‐binding model WHAM‐S 1.0/Model V. Using CuCl2‐extractable Al in horizons with in‐situ pH < 4.3 and ammonium oxalate/oxalic acid‐extractable Al in horizons with in‐situ pH > 4.3 as an estimate of the “reactive” pools of solid‐phase Al, we were able to get reasonable to good descriptions of the measured total Al concentrations in all horizons studied. These results vindicate the use of WHAM‐S 1.0 to help interpret complex interactions between metals and OM as they occur in the podzolization process. They also support our previous conclusions with respect to the mechanisms governing the solubility and mobility of Al in intrazonal podzols.
Novel micro–suction‐cup design for sampling soil solution at defined distances from roots
Authors: Puschenreiter Markus , Wenzel Walter W. , Wieshammer Gottfried , Fitz Walter J. , Wieczorek Simone , Kanitsar Katherina , Köllensperger Gunda
Published: June 2005

Micro–suction cups made of nylon membranes and polyacrylic tubes with planar geometry of the membrane were designed for repeated sampling of rhizosphere solution at defined distances from a root monolayer. Adsorption tests revealed that the materials used (nylon membrane, polyacrylic tube) have little influence on the concentration of heavy metals in the sample solution, whereas some organic acids are partly retained by the suction cup. A sampling protocol was developed for collecting extremely small solution volumes (i.e., droplets of 28.3±2.46 μl) for subsequent measurements of trace elements using ICP‐SFMS. A homogeneity test showed that soil‐solution concentrations of Ca, K, Mg, and Ni could be reproduced independent of the suction‐cup position in a rhizobox experiment without plants. In a similar experiment, the rhizobox was planted with the Ni hyperaccumulator Thlaspi goesingense. Compared to more distant soil layers, an increase of Ni and a concurrent decrease of Ca, K, and Mg at 1 mm distance from the root plane was found. These changes can be related to plant uptake and mobilization processes. Our results show that the novel micro–suction cups are a valuable tool for elucidating rhizosphere processes.
Growth, phosphorus uptake, and rhizosphere microbial‐community composition of a phosphorus‐efficient wheat cultivar in soils differing in pH
Authors: Marschner Petra , Solaiman Zakaria , Rengel Zed
Published: June 2005

In a pot experiment, the P‐efficient wheat (Triticum aestivum L.) cultivar Goldmark was grown in ten soils from South Australia covering a wide range of pH (four acidic, two neutral, and four alkaline soils) with low to moderate P availability. Phosphorus (100 mg P kg–1) was supplied as FePO4 to acidic soils, CaHPO4 to alkaline, and 1:1 mixture of FePO4 and CaHPO4 to neutral soils. Phosphorus uptake was correlated with P availability measured by anion‐exchange resin and microbial biomass P in the rhizosphere. Growth and P uptake were best in the neutral soils, lower in the acidic, and poorest in the alkaline soils. The good growth in the neutral soils could be explained by a combination of extensive soil exploitation by the roots and high phosphatase activity in the rhizosphere, indicating microbial facilitation of organic‐P mineralization. The plant effect (soil exploitation by roots) appeared to dominate in the acidic soils. Alkaline phosphatase and diesterase activities in acidic soils were lower than in neutral soils, but strongly increased in the rhizosphere compared with the bulk soil, suggesting that microorganisms contribute to P uptake in these acidic soils. Shoot and root growth and P uptake per unit root length were lowest in the alkaline soils. Despite high alkaline phosphatase and diesterase activities in the alkaline soils, microbial biomass P was low, suggesting that the enzymes could not mineralize sufficient organic P to meet the demands of plants and microorganisms. Microbial‐community composition, assessed by fatty acid methylester (FAME) analysis, was strongly dependent on soil pH, whereas other soil properties (organic‐C or CaCO3 content) were less important or not important at all (soil texture).
The intake of dietary fiber from grape seeds modifies the antioxidant status in rat cecum
Authors: Goñi Isabel , Serrano José
Published: June 2005

The aim of this study was to measure the antioxidant activity and polyphenolic compounds in cecum and feces of rats fed with a grape seed concentrate. The grape concentrate was rich in indigestible compounds (dietary fiber, polyphenols and other associated compounds) which presented significant antioxidant activity. Polyphenols extracted by aqueous–organic solvents (extractable polyphenols, EPs) and non‐extractable polyphenols (NEPs) exhibited high antioxidant capacity as measured by the ABTS method. High correlations were found between antioxidant capacity values and EP (r2 = 0.9608) and NEP content (r2 = 0.9179). EPs and NEPs exhibited considerable antioxidant activity within the large intestine. Significant antioxidant activity was also found in feces derived from excreted EPs and NEPs. The grape fiber concentrate enhanced the antioxidant status in the large intestine. The antioxidant activity in the intestinal content should be considered when assessing the effects of dietary components on bowel diseases. Copyright © 2005 Society of Chemical Industry
Enhancing the transfer of knowledge resources through effective utilization of labor and technology in a global organization: a case study of Bovis Lend Lease Inc.'s global knowledge transfer system
Authors: Kudyba Stephan
Published: June 2005

Management initiatives have increased their intensity on enhancing operating efficiency and productivity across functional areas of the organization. Early efforts focused on investment in information technologies as organizations sought to transform their capital infrastructures to become more IT intensive. To more fully achieve productivity gains, however, management tactics have recently focused on more effectively utilizing the available knowledge resources that reside in their organization that exist in their employee base. The process of effectively identifying and transferring value‐added knowledge existing in the firm to functional areas which require the resource in a timely manner often involves the incorporation of labor and technology. The following paper illustrates current trends in knowledge management initiatives for a global real estate investment and construction services company. Copyright © 2005 John Wiley & Sons, Ltd.
Modeling of Particle Fragmentation in Heterogeneous Olefin Polymerization Reactions, 2
Authors: Merquior Douglas M. , Lima Enrique L. , Pinto José C.
Published: May 2005

Summary: A two phase dynamic model is proposed here for the first time to describe the first stages of heterogeneous olefin polymerization and to improve predictions of particle morphology. Taking into account the solid and fluid phases, the two phase model allows for the calculation of the convective flux inside the growing polymer particle. Numerical simulations performed for both gas and slurry polymerizations show that the performances of the traditional diffusion model and of the proposed heterogeneous model are similar when mild polymerization conditions are considered, but may be very different when vigorous polymerization conditions are analyzed. It is shown that the development of convective flow inside the particle can exert a large influence on the course of the polymerization and on the final morphological characteristics of the polymer particle. When the initial catalyst particle contains inert material, it is also shown here that the inert material can contribute to a reduction of local reaction rates during particle breakup and, therefore, to a more uniform particle fragmentation.

Schematic representation of a nascent polymer particle.

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Schematic representation of a nascent polymer particle.
Investigation of the Variation of Unit Cell Dimensions of Crystalline Polymers with High‐Resolution FT‐IR Spectroscopy
Authors: Su Zhiqiang , Zhao Ying , Kang Ning , Zhang Xiuqin , Xu Yizhuang , Wu Jinguang , Wang Dujin , Han Charles C. , Xu Duanfu
Published: June 2005

Summary: High‐resolution FT‐IR spectroscopy has been used for the first time to characterize the variation of the unit cell dimensions of high‐density polyethylene (HDPE). In combination with the unit cell parameters of HDPE measured at different temperatures by Swan using wide‐angle X‐ray diffraction, the relationship between the rocking band shift (730 cm−1) and the change of the unit cell volume of HDPE has been established.

High‐resolution variable‐temperature FT‐IR spectra of HDPE rocking bands with decreasing temperature.

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High‐resolution variable‐temperature FT‐IR spectra of HDPE rocking bands with decreasing temperature.
Discovering new invertebrate neuropeptides using mass spectrometry
Authors: Hummon Amanda B. , Amare Andinet , Sweedler Jonathan V.
Published: June 2005

Neuropeptides are a complex set of messenger molecules controlling a wide array of regulatory functions and behaviors within an organism. These neuromodulators are cleaved from longer protein molecules and often experience numerous post‐translational modifications to achieve their bioactive form. As a result of this complexity, sensitive and versatile analysis schemes are needed to characterize neuropeptides. Mass spectrometry (MS) through a variety of approaches has fueled the discovery of hundreds of neuropeptides in invertebrate species in the last decade. Particularly successful are direct tissue and single neuron analyses by matrix‐assisted laser desorption/ionization (MALDI) MS, which has been used to elucidate approximately 440 neuropeptides, and examination of neuronal homogenates by electrospray ionization techniques (ESI), also leading to the characterization of over 450 peptides. Additional MS methods with great promise for the discovery of neuropeptides are MS imaging and large‐scale peptidomics studies in combination with a sequenced genome. © 2005 Wiley Periodicals, Inc.
Role of Electrospun Nanofibers in Stem Cell Technologies and Tissue Engineering
Authors: Boudriot Ulrich , Goetz Bernhard , Dersch Roland , Greiner Andreas , Wendorff Joachim‐H.
Published: June 2005

Tissue engineering is a promising tool to manage structural and functional defects in bone and cartilage. To provide optimal conditions for three‐dimensional cell growth the use of a scaffold is necessary. The aim of the study was to prove osteogenic differentiation of human mesenchymal stem cells (hMSC) onto a three‐dimensional, nanostructured scaffold of electrospun poly (l‐lactide)‐nanofibers. HMSC were seeded onto this matrix and differentiated for 21 days. Cells clearly preferred a guided growth along the nanofibers and revealed no signs of cell‐death. Osteogenic differentiation of hMSC onto the matrix has been demonstrated. Due to the fine structure, electrospun nanofibers promises to be an ideal scaffold for tissue engineering. They can be enriched with additives and are equally biocompatible and biodegradable.
Ultra‐Hydrophilic Transition Metals as Histophilic Biomaterials
Authors: Jennissen Herbert P.
Published: June 2005

Extremely hydrophilic surfaces have been prepared on titanium, stainless steel and cobalt chromium alloys after treatment by a chromosulfuric acid method at 200‐240 °C. In spite of a ca. 300‐500‐fold higher surface roughness (Ra ∼ 880‐1100 nm) in comparison to the quartz glass controls (Ra ∼ 2‐3 nm), surfaces with contact angles close to 0° in the absence of contact angle hysteresis (ultra‐hydrophilic surfaces) were obtained. We have called this phenomenon “Inverse Lotus Effect”. Metal surface layers exhibiting such properties form excellent priming coats with bioadhesive properties (histophilic surfaces) for the attachment of biocoats consisting of BMP‐2 with bioactive properties in bone. Direct immobilization of BMP‐2 on implant surfaces eliminates the need for a separate BMP‐2 carrier or delivery system such as collagen, as is widely employed by others. A fundamental problem in such surfaces is that it is not at all certain that a protein immobilized in such a manner will retain its biological activity. In the case of BMP‐2 it can be shown in vitro that the novel surfaces are biologically active. Similarly in vivo studies indicate an accelerated and improved osseointegration.
The Effect of Degradation and Stabilization on the Mechanical Properties of Polymers Using Polypropylene Blends as the Main Example
Authors: Kausch H.H.
Published: June 2005

Degradation can result from a variety of chemical, physical and mechanical mechanisms, most of them involving a reduction of molecular weight and thus a decrease in the mechanical performance of the degraded polymer. A clear understanding and control of these mechanisms is absolutely essential: without stabilization some polymers (e.g. PVC, polyolefins) would not survive their processing undamaged. In this paper an overview of the different degradation mechanisms, their effect on molecular chains, and the methods used to characterize the extent of degradation will be given. Subsequently we establish some fundamental relationships between the microstructure and the mechanical performance (of thermoplastic polymers) using differently aged and stabilized polypropylene (PP) ‐ EPR compounds.

In particular we investigate the influence of two types of heat stabilizers (phenolic antioxidants and hindered amine stabilizer HAS) on the degradation behaviour of test specimens thermally aged at 120 and 135°C respectively. From an investigation of the changes with aging time in structure and low‐strain properties (yield stress, strain at yield, tensile modulus) and from the differences in the evolution of the fracture properties a molecular model of the chain scission mechanisms and of inter‐lamellar connectivity (through tie‐chain molecules) has been established, which allowed an explanation of the gradual change of the dominant deformation mechanism from cold drawing to crazing and brittle fracture.
Degradation of Polyolefins Prepared with Fischer‐Tropsch Derived Olefins
Authors: Tincul I. , Govender V. Thakally
Published: June 2005

Degradation of some copolymers of ethylene with Fischer‐Tropsch derived olefins was investigated. Hydroperoxide and carbonyl formation in samples of ethylene copolymers with heptene‐1, and ethylene multiple polymers with the Fischer‐Tropsch derived 3,4 methyl‐pentene and linear olefins were monitored by IR spectroscopy. The results correlated with results obtained from thermogravimetry, multiple extrusion and rheology in previous studies. It was shown that degradation of ethylene with Fischer‐Tropsch derived olefins is related to the type of branch introduced into the chain by the copolymerization with the particular olefin.
Theoretical Modeling of the Phase Separation Dynamics in Blends of Reactive Monomers
Authors: Yandek Gregory R. , Kyu Thein
Published: June 2005

Summary: Experimental observations of the dynamics of phase behavior for blends of reactive constituents, i.e. diglycidyl ether of bisphenol A (DGEBA), curing agent methylene dianiline (MDA), and a reactive liquid rubber (R45EPI), have been theoretically modeled by coupling system thermodynamics governed by a summation of the free energies of mixing and network elasticity with reaction kinetics and diffusion equations. Snap‐shots of the temporal evolution of ternary phase diagrams have been established based on the self‐condensation reactions of DGEBA‐MDA and R45EPI as well as a cross‐reaction between the two constituents forming a copolymer. Numerical solution of the proposed mean‐field model provides good qualitative agreement with experimental results, namely, the observance of phase separation followed by a phase dissolution and subsequent secondary segregation in a 50/25.4/50 DGEBA/MDA/R45EPI mixture, as well as a single gradual phase separation in a 70/25.4/30 mixture. The phase separation dynamics are explained by a competition between the growth in molecular weights of the reactive species rendering the systems towards instability, and the formation of copolymer acting to compatibilize the mixtures.

Theoretical phase diagram for a DGEBA/MDA/R45EPI system.

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Theoretical phase diagram for a DGEBA/MDA/R45EPI system.
Interface Structure between Immiscible Reactive Polymers under Transreaction: a Monte Carlo Simulation
Authors: He Xuehao , Nagel Jürgen , Lehmann Dieter , Heinrich Gert
Published: June 2005

Summary: The interface structure between two immiscible melts, a polycondensate polymer A (e.g., polycarbonate, polyester or polyamide) and a polymer B, was studied by means of Monte Carlo simulations using the bond fluctuation model. Polymer B contained a reactive end group (e.g., OH, NH2 or COOH). Copolymers were generated in‐situ at the interfaces by transreactions (alcoholysis, aminolysis or acidolysis), composing of various length of block A, depending on the position of transreaction in the polycondensate chain A. The content of copolymer at the interface increased with the time, particular fast at the early stage. Fragments of polymers A were released with an end group, reactive to polymers A. This resulted in the proceeding of internal transreactions. An asymmetric interface structure was formed. The simulation also showed that copolymers generated by interfacial transreactions increased the compatibility of the two polymers and enhanced the adhesion strength at the interfaces.

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Muscle‐fiber apoptosis in neuromuscular diseases
Authors: Tews Dominique S.
Published: June 2005

Muscle‐fiber loss is a characteristic of many progressive neuromuscular disorders. Over the past decade, identification of a growing number of apoptosis‐associated factors and events in pathological skeletal muscle provided increasing evidence that apoptotic cell‐death mechanisms account significantly for muscle‐fiber atrophy and loss in a wide spectrum of neuromuscular disorders. It became obvious that there is not one specific pathway for muscle fibers to undergo apoptotic degradation. In contrast, certain neuromuscular diseases seem to involve characteristic expression patterns of apoptosis‐related factors and pathways. Furthermore, there are some characteristics of muscle‐fiber apoptosis that rely on the muscle fiber itself as an extremely specified cell type. Multinucleated muscle fibers with successive muscle‐fiber segments controlled by individual nuclei display some specifics different from apoptosis of mononucleated cells. This review focuses on the expression patterns of apoptosis‐associated factors in different primary and secondary neuromuscular disorders and gives a synopsis of current knowledge. Muscle Nerve, 2005
Cardiac involvement in muscular dystrophies: Molecular mechanisms
Authors: Goodwin Fiona C. , Muntoni Francesco
Published: June 2005

In this review, we draw attention to the multiple mechanisms responsible for the pathogenesis of cardiomyopathies in patients with muscular dystrophies. More than one single mechanism is likely to be involved in the development of skeletal and cardiac muscle pathology even when there is a single protein defect. The best example is dystrophin deficiency, in which increased sarcolemmal permeability following eccentric exercise, reduced force generation, and abnormal signaling are all likely to contribute to the progressive muscle damage observed. In other conditions, such as the sarcoglycanopathies, a protein deficiency both in the striated cardiomyocte and the vascular smooth muscle appears to play a significant role. An entirely different mechanism of disease is likely in defects of nuclear envelope proteins, although the precise pathogenesis of this group of conditions is still not clear. Differences between the organization of skeletal and cardiac muscle protein complex are also only starting to emerge and will very likely be the focus of future research. Muscle Nerve, 2005
Motor unit action potential topography and its use in motor unit number estimation
Authors: Blok Joleen H. , van Dijk Johannes P. , Zwarts Machiel J. , Stegeman Dick F.
Published: June 2005

High‐density multichannel electromyography (EMG) recordings add spatial information to the temporal information content of the surface EMG (sEMG) signal. This study explores the potential value of such multichannel information at a single motor unit level, in particular for the improvement of motor unit number estimation (MUNE) techniques. It is shown that multichannel recordings make it easier to distinguish motor unit action potentials (MUAPs) and that MUAP combinations can be better resolved. Furthermore, the spatiotemporal information allows a quantitative assessment of the representativity of the mean of the recorded MUAPs in relation to the maximum CMAP, i.e., for the muscle as a whole. In general, this is practically impossible on the basis of temporal information alone. For these reasons, we expect that high‐density sEMG has the potential to address several methodological limitations of single channel surface EMG recordings. This is specifically illustrated in this study for one of the MUNE techniques in use, the F‐response method. Muscle Nerve, 2005
Spastic muscle properties are affected by length changes of adjacent structures
Authors: Smeulders Mark J. C. , Kreulen Michiel , Hage J. Joris , Huijing Peter A. , van der Horst Chantal M. A. M.
Published: June 2005

Recent animal experiments have shown that up to 37% of muscle force may be transmitted to adjacent structures rather than reach the insertion of the muscle's tendon, and that the extent of such force transmission depends on the length and relative position of these structures. We tested whether the force–length characteristics of the distally tenotomized human flexor carpi ulnaris muscle (FCU) of nine patients with cerebral palsy varied with the change of relative length of adjacent structures induced by a change of wrist position. In four patients, the FCU exerted up to 40% more active force in a flexed wrist position at short FCU length, whereas the active force was not significantly higher in the other five. In the same manner, passive force–length characteristics of the spastic FCU changed upon changes in wrist position. Variability in myofascial force transmission may partly explain the variability in success of the FCU‐transfer. Muscle Nerve, 2005
Neuropathology of paraneoplastic neuropathy with anti‐disialosyl antibody
Authors: Kobayashi Michio , Kato Kazumaro , Funakoshi Kei , Watanabe Sumio , Toyoshima Itaru
Published: June 2005

We report a paraneoplastic neuropathy with severe motor involvement following sensory‐ataxic disturbance. Anti‐disialosyl immunoglobulin M (IgM) antibody was detected in the course of malignant lymphoma of diffuse large B‐cell type, which usually spares the motor system. Onset was subacute, with relapsing and remitting sensory ataxia, muscle weakness, bulbar palsy, respiratory paralysis, and ophthalmoplegia; only neck rotation was retained in the terminal stage. Autopsy showed no lymphoma cells infiltrating the nervous system. Motor neurons survived in the spinal cord, but mean diameter of the ventral spinal nerve roots was reduced considerably. The gracile fasciculus and the sural nerve were more markedly degenerated than proximal portions. Morphometric study showed that most of the proximal motor and sensory axons did not extend distally. This autopsy report provides further definition of a neuropathy associated with malignant lymphoma and IgM antibodies against disialosyl residues. Muscle Nerve, 2005
A counterfort versus a cantilever retaining wall—a seismic equivalence
Authors: Chugh Ashok K.
Published: June 2005

A procedure is presented to develop geometric dimensions and material property values for a model cantilever wall from those of a prototype counterfort wall such that the model wall will simulate the response of the prototype wall for seismic loads. The equivalency criteria are given. A sample problem is included to illustrate the use of the proposed procedure. Accuracy of results is discussed. Published in 2005 by John Wiley & Sons, Ltd.
Secondary Burkitt lymphoma in a retinoblastoma patient with 13q deletion syndrome
Authors: Hongeng Suradej , Parapakpenjun Surapan , Pakakasama Samart , Rerkamnuaychoke Busaba , Pornkul Ratanaporn
Published: May 2005

We report a boy with constitutional deletion 13q chromosome associated with dysmorphic features and bilateral retinoblastoma. The patient developed secondary Burkitt lymphoma 5 years after the diagnosis of retinoblastoma at the age of 8 months. He has completed treatment for both malignancies. At present, he is 7 years old and still in remission. Pediatr Blood Cancer 2006,46:524–526. © 2005 Wiley‐Liss, Inc.
Multicentric osteosarcoma presenting as retrobulbar mass: A diagnostic enigma
Authors: Wong K.F. , Shu S.J. , Luk I.S.C. , Yuen H.L. , Leung J.N.S. , Chan J.K.C.
Published: May 2005

Osteosarcoma is the most common primary malignant bone tumor of children and adolescents. It often presents as a solitary lesion; multicentric osteosarcoma with synchronous lesions occurring at multiple skeletal sites is very rare. We report a 9‐year‐old boy with multicentric osteosarcoma who presented with a left retrobulbar non‐sclerotic mass. The multiple lesions in bone were mostly non‐sclerotic on radiological examination except for a single lesion in the left tibia. Biopsy of the retrobulbar mass showed an unclassifiable poorly differentiated malignant tumor. Marrow aspiration smears showed many large, often segregated, round cells that expressed NB84a. However, trephine biopsy showed the formation of tumoral osteoid by the malignant cells, finally permitting the definitive diagnosis of osteosarcoma to be made. A hypertetraploid clone with complex structural abnormalities was demonstrated by cytogenetic study. © 2005 Wiley‐Liss, Inc.
Free volume and the physico‐mechanical behaviour of polyurethane/polyacrylonitrile interpenetrating polymer networks: positron annihilation results
Authors: Kumar H , Siddaramaiah  , Kumaraswamy GN , Ravikumar HB , Ranganathaiah C
Published: June 2005

A series of semi‐interpenetrating polymer networks (SIPNs) of polyurethane (PU) and polyacrylonitrile (PAN) in the weight ratios 90/10, 70/30, 60/40 and 50/50 PU/PAN were prepared using polyethylene glycol, 4,4′‐diphenylmethane diisocyanate and acrylonitrile by sequential polymerization. Differential scanning calorimetry and scanning electron microscopy techniques were used to find the glass transition temperature and surface morphology of SIPNs. The tough and transparent SIPN films were characterized for physico‐mechanical properties such as density, surface hardness and tensile properties. Positron annihilation lifetime spectroscopy (PALS) was used to measure the free volume behaviour of the IPNs. The sorption behaviour of IPNs with benzene penetrant was also measured. An attempt was made to correlate the PALS results with the mechanical and sorption properties of the SIPNs. Copyright © 2005 Society of Chemical Industry
Spatial and temporal evolution of the photo initiation rate for thick polymer systems illuminated on both sides
Authors: Stephenson Nicole , Kriks Dane , El‐Maazawi Mohamed , Scranton Alec
Published: June 2005

Photopolymerizations of thick systems are inherently non‐uniform and much more complex than polymerizations of films and coatings. This contribution presents a mathematical description of the evolution of the photoinitiation rate profile for a thick photopolymerization system illuminated on two sides. Simulation results revealed that when two lamps of equal intensity are used, the spatial and temporal evolution of the photoinitiation rate profile follows a characteristic progression from a bimodal distribution to a unimodal shape with a maximum in the center of the sample. The addition of a second light source can lead to an initiation profile that is more uniform throughout the sample. System variables such as the initiator concentration, molar absorptivity and monomer absorptivity determine how the photoinitiation rate profile evolves. For example, increasing initiator concentration results in sharper initiation fronts which move through the sample more slowly. A reflective boundary condition, a special case of two‐sided illumination using only one lamp, was found to enhance the initiation rate and uniformity for some reaction systems. This model provides the fundamental understanding needed to ensure proper selection of reaction components for effective photoinitiation in thick systems, including the possibility of a second light source as an additional design variable. Copyright © 2005 Society of Chemical Industry
Synthesis and characterization of homo‐ and copolymers of 3‐(2‐cyano ethoxy)methyl‐ and 3‐[methoxy(triethylenoxy)]methyl‐3′‐methyl‐oxetane
Authors: Ye Lin , Feng Zeng‐guo , Su Yue‐feng , Wu Feng , Chen Shi , Wang Guo‐qing
Published: June 2005

Two oxetane‐derived monomers 3‐(2‐cyanoethoxy)methyl‐ and 3‐(methoxy(triethylenoxy)) methyl‐3′‐methyloxetane were prepared from the reaction of 3‐methyl‐3′‐hydroxymethyloxetane with acrylonitrile and triethylene glycol monomethyl ether, respectively. Their homo‐ and copolyethers were synthesized with BF3· Et2O/1,4‐butanediol and trifluoromethane sulfonic acid as initiator through cationic ring‐opening polymerization. The structure of the polymers was characterized by FTIR and1H NMR. The ratio of two repeating units incorporated into the copolymers is well consistent with the feed ratio. Regarding glass transition temperature (Tg), the DSC data imply that the resulting copolymers have a lower Tg than pure poly(ethylene oxide). Moreover, the TGA measurements reveal that they possess in general a high heat decomposition temperature. The ion conductivity of a sample (P‐AN 20) is 1.07 × 10−5 S cm−1 at room temperature and 2.79 × 10−4 S cm−1 at 80 °C, thus presenting the potential to meet the practical requirement of lithium ion batteries for polymer electrolytes. Copyright © 2005 Society of Chemical Industry
Francisella tularensis live vaccine strain: Proteomic analysis of membrane proteins enriched fraction
Authors: Pávková Ivona , Hubálek Martin , Zechovská Jana , Lenčo Juraj , Stulík Jiří
Published: June 2005

Proteome analysis of Gram‐negative facultative intracellular pathogen Francisella tularensis (F. tularensis) live vaccine strain has been performed only on whole‐cell extracts so far. This is the first study dealing with the analysis of the membrane subproteome of this microorganism. A fraction enriched in membrane proteins obtained by carbonate extraction was separated using two‐dimensional electrophoresis and all visualized spots were identified by mass spectrometry. The reference map is the basis for further comparative analyses of virulent and non‐virulent F. tularensis strains.
Lipase‐catalyzed ring‐opening polymerization of 6(S)‐methyl‐morpholine‐2,5‐dione
Authors: Feng Yakai , Klee Doris , Höcker Hartwig
Published: June 2005

Lipase‐catalyzed ring‐opening bulk polymerizations of 6(S)‐methyl‐morpholine‐2,5‐dione (MMD) were investigated. Selected commercial lipases were screened as catalysts for MMD polymerization at 100 °C. Polymerizations catalyzed with 10 wt % porcine pancreatic lipase type II crude (PPL), lipase from Pseudomonas cepacia, and lipase type VII from Candida rugosa resulted in MMD conversions of about 75% in 3 days and in molecular weights ranging from 8200 to 12,100. Poly(6‐methyl‐morpholine‐2,5‐dione) [poly(MMD)] had a carboxylic acid group at one end and a hydroxyl group at the other end. However, lipase from Mucor javanicus showed lower catalytic activity for the polymerization. During the polymerization, racemization of the lactate residue took place. PPL was selected for further studies. The rate of polymerization increased with increasing PPL concentration under otherwise identical conditions. When the PPL concentration was 5 or 10 wt % with respect to MMD, a conversion of about 70% was reached after 6 days or 1 day, respectively, whereas for a PPL concentration of 1 wt %, the conversion was less than 20% even after 6 days. High concentrations of PPL (10 wt %) resulted in high number‐average molecular weights (<3 days); with a lower concentration of PPL, lower molecular weight poly(MMD) was obtained. The concentration of water was an important factor that controlled not only the conversion but also the molecular weight. With increasing water content, enhanced polymerization rates were achieved, whereas the molecular weight of poly(MMD) decreased. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3030–3039, 2005
Novel photocurable monomers: The synthesis of difunctional vinyl ethers with a phosphonate group and difunctional 1‐propenyl ethers with a phosphonate group and their photoinitiated cationic polymerization
Authors: Minegishi Shouji , Otsuka Tetsurou , Kameyama Atsushi , Nishikubo Tadatomi
Published: June 2005

Phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were prepared by the regioselective addition reaction of glycidyl vinyl ether (GVE) or 1‐propenyl glycidyl ether with diaryl phosphonates with quaternary onium salts as catalysts. The reaction of GVE with bis(4‐chlorophenyl) phenylphosphonate gave bis[1‐(4‐chlorophenoxy methyl)‐2‐(vinyloxy)ethyl]phenylphosphonate in a 68% yield. The structures of the resulting phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were confirmed by IR and 1H NMR spectra and elemental analysis. Photoinitiated cationic polymerizations of the resulting phosphorus‐containing vinyl ether monomers and 1‐propenyl ether monomers were investigated with photoacid generators. The polymerization of vinyl ether groups and 1‐propenyl ether groups of the obtained monomers proceeded very smoothly with a sulfonium‐type cationic photoinitiator, bis[4‐(diphenylsulfonio)phenyl]sulfide‐bis(hexafluorophosphate), upon UV irradiation. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3105–3115, 2005
Synthesis and characterization of novel biodegradable epoxy‐modified polyurethane elastomers
Authors: Yeganeh Hamid , Lakouraj Moslem Mansour , Jamshidi Sadegh
Published: June 2005

Biodegradable polyurethane elastomers with the potential for applications in medical implants were synthesized from the reaction of epoxy‐terminated polyurethane prepolymers (EUPs) with 1,6‐hexamethylenediamine as a curing agent. EUPs were themselves prepared from the reaction of glycidol and isocyanate‐terminated polyurethanes made from different molecular weights of poly(ε‐caprolactone) (CAPA) and 1,6‐hexamethylene diisocyanate. All materials were characterized by spectroscopic methods. The curing conditions were optimized by gel content measurements. The curing kinetic and kinetic parameters were determined from differential scanning calorimetry measurements. The effects of changing the crosslink density and crystallinity of elastomers via the alteration of the CAPA polyol molecular weight on the physical, mechanical, and degradation properties of the final elastomeric polymers were examined fully. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2985‐2996, 2005
Synthesis and characterization of side‐chain liquid‐crystalline polymers and study of their role in the crystallization of high‐density polyethylene
Authors: Qiao Wen‐Qiang , Fan Xiao‐Dong , Kong Jie , Xie Yun‐Chuan , Si Qing‐Fa , Wang Sheng‐Jie , Liu Yu‐Yang
Published: June 2005

Side‐chain liquid‐crystalline polymers (SCLCPs) as nucleating agents for high‐density polyethylene (HDPE) were investigated. For this purpose, the molecular architectures of four different vinyl monomers with liquid‐crystalline properties were designed and prepared with 1‐butanol, 1‐pentanol, 4‐hydroxybenzoic acid, hydroquinone, and acryloyl chloride as the starting materials through alkylation and acylation reactions. The corresponding polymers were synthesized by homopolymerization in 1,4‐dioxane with benzoyl peroxide as the initiator at 60 °C. Both the monomers and the synthesized polymers were characterized with elemental analysis, Fourier transform infrared, and 1H NMR measurements. Differential scanning calorimetry, thermogravimetric analysis, and hot stage polarized optical microscopy were employed to study the phase‐transition temperature, mesophase texture, and thermal stability of the liquid‐crystalline polymers. The results showed that all the polymers had thermotropic liquid‐crystalline features. Being used as nucleating agents, SCLCPs effectively increased both the crystallization temperature and rate and, at the same time, raised the crystallinity for HDPE. In comparison with common small‐molecule nucleating agents, such as 1,3:2,4‐dibenzylidenesorbitol, SCLCPs are more efficient and are indeed excellent nucleating agents for HDPE. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3067–3078, 2005
Highly conductive soluble terpolymers of aniline, toluidine, and o‐aminobenzoic acid/m‐aminobenzenesulfonic acid
Authors: Savitha P. , Sathyanarayana D. N.
Published: June 2005

Two series of terpolymers, one of o‐/m‐toluidine and aniline with o‐aminobenzoic acid and the other of o‐/m‐toluidine and aniline with m‐aminobenzenesulfonic acid, have been synthesized by oxidative polymerization via an emulsion method with ammonium persulfate as the oxidant and HCl as the external dopant. The terpolymers exhibit excellent solubility and retain the high conductivity (∼1 S cm−1) characteristic of the unsubstituted homopolymer, polyaniline. The terpolymers also possess higher thermal stability than polyaniline. This can be attributed to the presence of internal doping groups and substituents, which introduce flexibility to the otherwise rigid polyaniline backbone. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 3040–3048, 2005
Viscoelastic characterization of polymers using instrumented indentation. I. Quasi‐static testing*
Authors: VanLandingham M. R. , Chang N.‐K. , Drzal P. L. , White C. C. , Chang S.‐H.
Published: June 2005

The use of instrumented indentation to characterize the mechanical response of polymeric materials was studied. A model based on contact between a rigid probe and a linear viscoelastic material was used to calculate values for the creep compliance and stress relaxation modulus for two glassy polymeric materials, epoxy and poly(methyl methacrylate), and two poly(dimethyl siloxane) (PDMS) elastomers. Results from bulk rheometry studies were used for comparison with the indentation stress relaxation results. For the two glassy polymers, the use of sharp pyramidal tips produced responses that were considerably more compliant (less stiff) than the rheometry values. Additional study of the deformation remaining in epoxy after indentation creep testing as a function of the creep hold time revealed that a large portion of the creep displacement measured was due to postyield flow. Indentation creep measurements of the epoxy with a rounded conical tip also produced nonlinear responses, but the creep compliance values appeared to approach linear viscoelastic values with decreasing creep force. Responses measured for the unfilled PDMS were mainly linear elastic, with the filled PDMS exhibiting some time‐dependent and slight nonlinear responses in both rheometry and indentation measurements. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1794–1811, 2005
Perceptions of changes in weight among African American breast cancer survivors
Authors: Weathers Benita , Barg Frances K. , Collier Aliya , Halbert Chanita Hughes
Published: June 2005

Back ground: Although African American breast cancer survivors are most likely to gain weight following diagnosis and treatment compared to women from other ethnic groups, limited information is available on psychological and behavioral reactions to weight change in this population.

Objectives: To explore perceptions and reactions to weight change in African American breast cancer survivors.

Methodology: A parallel mixed methods approach was used to explore experiences with and reactions to weight change following breast cancer diagnosis and treatment. Participants were 16 short‐ and long‐term African American breast cancer survivors.

Results: Nine out of 16 participants gained weight following diagnosis and treatment and most participants were concerned about these changes. Most participants were also interested in diet and exercise programs; however, a holistic and common sense approach to diet and physical activity emerged as key themes.

Conclusions: Although prior reports have found that African American women in the general population report a greater tolerance for larger body sizes, most participants in this study were concerned about changes in their weight and were actively trying to minimize weight gain. Several themes emerged regarding physical activity and dietary behaviors; overall, participants described a holistic and practical approach to these behaviors. Copyright © 2005 John Wiley & Sons, Ltd.
Soft Plasma Treated Surfaces: Tailoring of Structure and Properties for Biomaterial Applications
Authors: Förch Renate , Zhang Zhihong , Knoll Wolfgang
Published: June 2005

Summary: This paper aims to discuss and review developments in plasma surface modification techniques which have been seen over the past few years, with particular emphasis on low energy or soft plasma assisted surface polymerisation processes. While early work focussed mainly on protective coatings and surface activation, the advancements in microtechnology in the 1980s followed by those in nanotechnology in the 1990s and 2000s have resulted in new challenges for surface processing and surface modification processes. The latest advancements in plasma polymer chemistry have shown tremendous potential for the synthesis of reasonably well defined molecular structures with a high retention of functional groups. Some of the latest achievements and newest insights into the behaviour of such deposits in a liquid environment will be discussed, with a particular focus on bio‐nanotechnological applications. Utilising novel approaches in surface and interface analysis, it will be shown that plasma polymers can be tailored to have considerable elasticity with reversible swelling characteristics, offering a three‐dimensional interface for biomolecular immobilisation procedures in a liquid environment.

SPR data suggesting the elastic and reproducible swelling and shrinking of pp‐allylamine under a humid nitrogen environment.

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SPR data suggesting the elastic and reproducible swelling and shrinking of pp‐allylamine under a humid nitrogen environment.
RF Plasma Sputtering Deposition of Hydroxyapatite Bioceramics: Synthesis, Performance, and Biocompatibility
Authors: Xu Shuyan , Long Jidong , Sim Lina , Diong Cheong Hoong , Ostrikov Kostya (Ken)
Published: June 2005

Summary: Hydroxyapatite (HA) coatings have numerous applications in orthopedics and dentistry, owing to their excellent ability to promote stronger implant fixation and faster bone tissue ingrowth and remodeling. Thermal plasma spray and other plasma‐assisted techniques have recently been used to synthesize various calcium phosphate‐based bioceramics. Despite notable recent achievements in the desired stoichiometry, phase composition, mechanical, structural, and biocompatible properties, it is rather difficult to combine all of the above features in a single coating. For example, many existing plasma‐sprayed HA coatings fall short in meeting the requirements of grain size and crystallinity, and as such are subject to enhanced resorption in body fluid. On the other hand, relatively poor interfacial bonding and stability is an obstacle to the application of the HA coatings in high load bearing Ti6Al4V knee joint implants. Here, we report on an alternative: a plasma‐assisted, concurrent, sputtering deposition technique for high performance biocompatible HA coatings on Ti6Al4V implant alloy. The plasma‐assisted RF magnetron co‐sputtering deposition method allows one to simultaneously achieve most of the desired attributes of the biomimetic material and overcome the aforementioned problems. This article details the film synthesis process specifications, extensive analytical characterization of the material's properties, mechanical testing, simulated body fluid assessments, biocompatibility and cytocompatibility of the HA‐coated Ti6Al4V orthopedic alloy. The means of optimization of the plasma and deposition process parameters to achieve the desired attributes and performance of the HA coating, as well as future challenges in clinical applications are also discussed.

SEM image of differentiated cells on HA bioceramics deposited by plasma sputtering, after a two‐day incubation period.

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SEM image of differentiated cells on HA bioceramics deposited by plasma sputtering, after a two‐day incubation period.
Transmission Fluctuation Spectrometry in Concentrated Suspensions. Part Three: Measurements
Authors: Shen Jianqi , Riebel Ulrich
Published: June 2005

The theory of transmission fluctuation spectrometry (TFS) was developed for particle size analysis in flowing particle suspensions, whereby the statistical transmission fluctuations are used to extract the particle size distribution (PSD) and particle concentration.

In the previous parts of this publication high concentration effects on TFS were investigated theoretically and by simulation. This work presents a study on TFS measurements in concentrated suspensions. By introducing an empirical correction to include the high concentration effects from both the monolayer structure and particle overlapping in the inversion algorithm, it is possible to obtain the particle size distribution and particle concentration over broad ranges of particle sizes and concentrations.