bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cloning of an alfalfa polyphenol oxidase gene and evaluation of its potential in preventing postharvest protein degradation
Authors: Sullivan Michael L , Hatfield Ronald D , Samac Deborah A 
Published: April 2008

AbstractBACKGROUND: Ensiling forages often leads to degradation of protein to non‐protein nitrogen (NPN), which is poorly utilized by ruminants. Postharvest protein degradation is especially high in alfalfa (Medicago sativa L.). In contrast, red clover (Trifolium pratense L.) has up to 90% less protein loss during ensiling due to polyphenol oxidase (PPO) forming o‐quinones from endogenous o‐diphenols and subsequent binding of o‐quinones to cytoplasmic proteins. Here we determined whether an endogenous PPO might be exploited for postharvest protein protection in alfalfa.RESULTS: We isolated an alfalfa PPO gene (MsPPO1) that shares limited sequence identity (70–72%) with red clover PPO genes. MsPPO1 is expressed primarily in flowers and developing seed pods, but not in leaves or stems. Expression of MsPPO1 from a strong constitutive promoter in transgenic alfalfa results in accumulation of PPO transcripts in leaves, but little enzyme activity is detected using a variety of o‐diphenol substrates unless assayed in the presence of sodium dodecyl sulfate (SDS). Under this SDS‐activated condition, preference of MsPPO1 for tested substrates is catechol ≥ (−)‐epicatechin > caffeic acid. PPO activity in unactivated MsPPO1‐alfalfa extracts is sufficient to inhibit proteolysis in the presence of catechol, but not caffeic acid or (−)‐epicatechin. Inhibition is less than in extracts of alfalfa expressing the red clover PPO1 gene.CONCLUSION: Endogenous alfalfa PPO, even if expressed in appropriate target tissues, would be less effective at preventing proteolytic losses in ensiled forages than red clover PPO. Published in 2008 by John Wiley & Sons, Ltd.
Poly(ether ester amide) Microspheres for Protein Delivery: Influence of Copolymer Composition on Technological and Biological Properties
Authors: Ostacolo Luisanna , Russo Paola , De Rosa Giuseppe , La Rotonda Maria Immacolata , Maglio Giovanni , Nese Giuseppe , Spagnuolo Gianrico , Rengo Sandro , Oliva Adriana , Quaglia Fabiana 
Published: April 2008

AbstractThe production of PEEA microspheres with potential as carriers for protein oral delivery is described. PEEAs with different hydrophilicity were synthesized and characterized. Experiments showed that an increase in copolymer hydrophilicity gave particles less prone to cell interaction. BSA release profiles from PEEA microspheres demonstrated that an increase in polymer hydrophilicity was useful in limiting protein burst and modulating drug delivery rate by increasing PEEA degradability. These results show that fine‐tuning of the hydrophilic/hydrophobic properties of PCL is essential for the formulation protein‐loaded microspheres with specific properties.magnified image
Novel Triaromatic Ester Mesogenic Liquid Crystalline Epoxy Resin Containing Both Methyl Substituent and Ethoxy Flexible Spacer: Synthesis and Curing
Authors: Liu Guo‐dong , Zhou Bo , Zhao Dong‐mei , Li Qing , Gao Jun‐gang 
Published: April 2008

AbstractA novel triaromatic ester liquid crystalline epoxy resin (LCER) that contains both a methyl substituent and an ethoxy flexible spacer, p‐methylphenylene di{4‐[(2,3‐epoxypropoxy)ethoxy]benzoate} (MPEPEB), has been synthesized. The mesotropic property has been investigated by differential scanning calorimetry (DSC) and polarized light optical microscopy (POM). MPEPEB shows a lower melting temperature at 78.7 °C and a broad nematic mesophase temperature range of about 55 °C. Meanwhile MPEPEB shows a mesophase to −50 °C upon cooling. The curing behavior of MPEPEB with 2,6‐diamino‐3,5‐diethyltoluene (DAE) has been investigated by means of DSC and POM during isothermal and dynamic processes. Although there is little difference between the activation energies obtained from the kinetic data, a marked difference is found between the isothermal and dynamic investigation. The curing reaction in the isothermal investigation roughly obeys n‐th order kinetics, while two exothermal peaks appear in the dynamic DSC curves of MPEPEB/DAE. A comparison of the isothermal and dynamic data shows that the curing rate is not a unique function of temperature and curing degree. The cured networks have lower glass temperatures and show a mesophase at room temperature which disappears at about 86–88 °C.magnified image
Vacuum‐Ultraviolet Photopolymerisation of Amine‐Rich Thin Films
Authors: Truica‐Marasescu Florina , Wertheimer Michael R. 
Published: April 2008

AbstractNitrogen‐rich organic thin films were deposited by VUV‐assisted photochemical polymerisation of flowing C2H4/NH3 mixtures. The fundamental reaction mechanisms of these binary gas mixtures were investigated as a function of the wavelength of two almost monochromatic VUV sources. Compositions of these “UV‐PE:N” films close to the surface were determined by XPS, and the amine concentrations and selectivities were quantified via chemical derivatisation. The UV‐PE:N films were compared with plasma polymers deposited using low‐pressure glow discharges in similar gas flow mixtures, “L‐PPE:N”; it is shown that VUV photochemistry is superior to plasma chemistry in producing almost monofunctional organic thin films.magnified image
Linear High Molecular Weight Ladder Polymer via Fast Polycondensation of 5,5′,6,6′‐Tetrahydroxy‐3,3,3′,3′‐tetramethylspirobisindane with 1,4‐Dicyanotetrafluorobenzene
Authors: Du Naiying , Song Jingshe , Robertson Gilles P. , Pinnau Ingo , Guiver Michael D. 
Published: April 2008

AbstractA high molecular weight ladder polymer based on 5,5′,6,6′‐tetrahydroxy‐3,3,3′,3′‐tetramethylspirobisindane and 1,4‐dicyanotetraflurobenzene has been synthesized by polycondensation under high‐intensity mixing conditions at about 155 °C and cyclic‐free products were obtained in high yield with low molecular weight distribution (1.7–2.3). The reaction could be completed within a few minutes. The polymer properties were characterized by GPC, 1H NMR, 13C NMR, F NMR, FT‐IR, and MALDI‐TOF MS. In addition, the mechanical properties, apparent surface areas and gas permeability are also reported. This procedure can also be used for the synthesis of other ladder polymers by irreversible polycondensations of tetraphenols with activated tetrafluoro aromatics.magnified image
Enzyme‐Catalyzed Ring‐Opening Polymerization of Unsubstituted β‐Lactam
Authors: Schwab Leendert W. , Kroon Renee , Schouten Arend Jan , Loos Katja 
Published: April 2008

AbstractThe synthesis of poly(β‐alanine) by Candida antarctica lipase B immobilized as novozyme 435 catalyzed ring‐opening of 2‐azetidinone is reported. After removal of cyclic side products and low molecular weight species pure linear poly(β‐alanine) is obtained. The formation of the polymer is confirmed with 1H NMR spectroscopy and MALDI‐TOF mass spectrometry. The average degree of polymerization of the obtained polymer is limited to $\overline {DP}$ = 8 by its solubility in the reaction medium. Control experiments with β‐alanine as a substrate confirmed that the ring structure of the 2‐azetidinone is necessary to obtain the polymer.magnified image
Fiber reinforced refractory castables for SPF toolings
Authors: Bernhart G. , Nazaret F. , Cutard T. 
Published: April 2008

AbstractFiber reinforced refractory castable (FRRC) is an emerging material solution to manufacture SPF tools for forming titanium alloy sheets. Indeed, FRRC are able to conserve good mechanical properties up to 900 °C. Fiber reinforcement allows to improve mechanical properties and to avoid a catastrophic failure. Moreover, constitutive laws can be considered to reproduce the FRRC’s mechanical behaviour when using FEM codes. As a consequence, it is now possible to proceed to a numerical design of SPF tools that are based on FRRC. Following this route, large SPF tools have been designed, manufactured and tested under industrial conditions. Successful results have been obtained in the field of forming TA6V sheets.
The suitability of dental investment materials as dies for superplastic forming of medical and dental prostheses
Authors: Curtis R.V. 
Published: April 2008

AbstractDental investment materials have long been used in the manufacture of a whole variety of customised prostheses for dental restorative procedures. The metal castings produced often have very complex shapes and unless certain protocols are followed the range of casting errors can be great. Fortunately, the dental profession has a long experience with the Lost Wax Casting procedure and such problems are rare.More recently, the investment materials commonly used to manufacture the casting moulds have been applied to the manufacture of dies for the production of dental and maxillofacial prostheses in titanium materials, such as Ti‐6Al‐4V and SP700 alloys. A range of studies has been conducted to assess the suitability of a variety of investment material types, all of which are available commercially. This paper will focus upon the physical properties of dental investment materials that are used to manufacture dies for the superplastic forming of dental and maxillofacial prostheses. In addition to the consideration of the physical properties of the die materials, other relevant issues include the die – titanium sheet interactions and post‐forming titanium sheet properties such as contamination and biocompatibility.Such issues will be discussed in relation to regulatory issues concerning the use of biomaterials for the restoration of bodily function.
Some examples of current diffusion bonding applications
Authors: Wilden J. , Jahn S. , Beck W. 
Published: April 2008

AbstractIn recent years a renaissance of diffusion bonding can be observed. Beside applications in the aerospace industry more and more industrial users take advantage of the solid state joining process. The progressive development of micro technologies results from the systematic miniaturization efforts for electrical, optical and mechanical components. A major role for this is taken by the application of scale effects. Today, micro structured‐components are already deployed in telecommunication, mechanical engineering, medicine‐ and biotechnology.During this continuous top‐down process the performance of a component should at least be equal or rather enhanced as compared to the conventional processed part. Increasing computational power needs a safely controlled and managed heat generation and distribution in any of such components.This is not only important for electronic devices, but also for tools used for micro injection molding. With the combination of machining or laser cutting and subsequent diffusion bonding it is possible to freely design and manufacture the required parts with an inside structure. In this paper an enhanced process chain for production of parts by a lamination technology, which is capable to solve scale restrictions, is presented as well as application examples and process specific features, Fig. 1.
Cavity growth simulation for superplastic deformation of tetragonal Zirconia polycrystal, 3Y‐TZP
Authors: Harjo S. , Kojima N. , Motohashi Y. 
Published: April 2008

AbstractA simulation based on cavity number ‐ radius distribution obtained from a scanning electron microscopy analysis was made to consider cavity growth rate and its mechanism during superplastic deformation of a tetragonal zirconia polycrystal (3Y‐TZP). It is found that (1) newly formed cavities grow very rapidly in an early stage of their growth process and then the growth rate becomes gradually slow with the increase in cavity size, and (2) the cavity growth process in the 3Y‐TZP is governed by the diffusion‐controlled mechanism.
String theory and cosmic connection during super plastic flow
Authors: Muñoz‐Andrade J.D. 
Published: April 2008

AbstractThe objective of this work is to describe the string theory and cosmic connection during super plastic flow in spatially extended polycrystalline systems (SEPCS), where the phenomenology and mechanics of the crystalline structure of the universe in a relativistic framework at Max Planck scale plays an important role. According to string theory as the unified theory of every thing, dislocations dynamics is related in nature form with the string theory. Consequently, dislocations at Max Plank scale are the universal way of working of every thing. In this physical framework, the theoretical model of Muñoz‐Andrade allows obtained the activation energy for super plastic flow in SEPCS. Finally, the main results of this work are analyzed in the context of the unified interpretation of string theory as cosmic connection during Hubble flow, plastic flow and super plastic flow.
Novel efficient DOPO‐based flame‐retardants for PWB relevant epoxy resins with high glass transition temperatures
Authors: Ciesielski M. , Schäfer A. , Döring M. 
Published: April 2008

AbstractNovel derivatives of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) were obtained by a simple synthetic route and incorporated in epoxy resins, consisting of epoxy novolac (DEN 438), dicyandiamide (DICY), and fenuron. The thermal and fire‐retardant properties of DICY‐cured DEN 438 epoxy samples containing the novel DOPO‐based additives were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and the UL 94 test. The obtained results were compared to those of specimens containing commercially available phosphates as flame‐retardants. UL 94 tests showed that nitrogen‐containing substituents at the phosphorus atom increase the fire‐retardant efficiency of DOPO‐based additives. Two nitrogen‐substituted DOPO derivatives 4,4′‐Diaminodiphenylmethane (DDM)‐(DOP)2 and DDM‐(DOP)2‐S were found to be very powerful fire‐retardants in DICY‐cured DEN 438 epoxy resins. The V0 rating was achieved at approximately 1% phosphorus in the resin and the glass transition temperature (Tg) was maintained at the high level of the pure DEN 438/DICY epoxy material (Tg = 180–185°C). These novel DOPO derivatives are the first non‐reactive additives having no influence on the Tg of the epoxy material. They not only surpass the capabilities of the other additives used in this work, but also those of all commercially available flame‐retardants for epoxy resins. Therefore, DDM‐(DOP)2 and DDM‐(DOP)2‐S are expected to be qualified for high‐Tg resins commonly used in printed wiring boards (PWB) for high‐performance applications. Copyright © 2008 John Wiley & Sons, Ltd.
Nanostructured polyolefins/clay composites: role of the molecular interaction at the interface
Authors: Passaglia Elisa , Bertoldo Monica , Coiai Serena , Augier Sylvain , Savi Stefania , Ciardelli Francesco 
Published: April 2008

AbstractThe extent of interphase interactions between polymer phase and inorganic particles is the driving force addressing the preparation/properties design in the field of the corresponding micro‐ and nanocomposites. In the case of preparation of nanocomposites based on polyolefins (POs) and inorganic compounds as potentially nanodispersed phase, the use of a PO with proper functional groups is necessary for the interface adhesion and stabilization of the nanostructured morphology. According to this approach, ethylene/propylene copolymers with a different propylene content were used for the preparation of nanocomposites through melt mixing with organophilic montmorillonites (OMMT). By taking into account the important role of functionalities grafted onto POs, two different synthetic approaches were compared here: (1) the dispersion of the inorganic filler was obtained by using previously functionalized POs bearing carboxylate groups as matrices; (2) the nanocomposites were prepared by performing contemporaneously the functionalization of POs (by using maleic anhydride (MAH) and/or diethyl maleate (DEM)) and the dispersion of the filler in a one‐step process. The morphology of the nanocomposites as well as the variation of solubility and glass transition temperature (Tg) of the PO matrix were evaluated and tentatively discussed with reference to functionalization degrees, structure of PO, and preparation procedure. Copyright © 2008 John Wiley & Sons, Ltd.
Influence of talc on the fire retardant properties of highly filled intumescent polypropylene composites
Authors: Duquesne S. , Samyn F. , Bourbigot S. , Amigouet P. , Jouffret F. , Shen K. 
Published: April 2008

AbstractIntumescent systems have been developed since many years for a wide range of applications, even if they are mainly used in coatings nowadays. The objective of this paper is to determine if the intumescent concept can be applied to highly filled reinforced polypropylene (PP) composites containing talc. Formulations that meet the electrical industry requirements have been developed, even if it has been observed that the addition of talc into intumescent PP leads to a decrease in the fire retardancy of the systems. A thermal stabilization of the material is noted at high temperature in the presence of talc. An increase in the crystallinity of the intumescent structure is suspected to be, at least partially, responsible for the decrease in the performance. Copyright © 2008 John Wiley & Sons, Ltd.
Polychromatic light‐emitting conjugated polymer prepared by controlling its structure through active free radical addition
Authors: Zhang Jian‐Jun , Gao Ge , Dong Wei , Zhao Da‐Cheng , Liu Feng‐Qi 
Published: April 2008

AbstractBACKGROUND: The HOMO–LUMO energy level width of conjugated polymers can be manipulated by controlling the conjugation length of the polymeric materials in order to adjust their properties in terms of emission of different colors and realize polychromatic displays. In the work reported in this paper azobisisobutyronitrile (AIBN) was used to control the conjugation length of poly[2‐methoxy‐5‐(2′‐ethylhexyloxy)‐co‐(1,4‐phenylene vinylene)] (MEH‐PPV) by free radical addition. In this way a series of MEH‐PPV with various conjugation lengths was obtained.RESULTS: Characterization of MEH‐PPV using 1H NMR and Fourier transform infrared spectroscopy demonstrated that the cyano groups of AIBN hydrolyzed into carboxyls. The carboxyl free radicals attacked the conjugated double bonds of MEH‐PPV, resulting in a decrease of trans‐vinylenes and in an increase of cis‐vinylenes as well as tert‐methyls on the backbone. Changing the conjugated structure of the polymer caused the peaks of UV and fluorescence spectra to shift to the blue.CONCLUSION: The resulting MEH‐PPV derivatives can emit orange‐red, green and blue light. It is expected that they could be used to prepare PPV‐based materials that could modulate white light emission, by simply blending the PPV derivatives emitting different colors. Copyright © 2008 Society of Chemical Industry
Applied Plasma Medicine
Authors: Fridman Gregory , Friedman Gary , Gutsol Alexander , Shekhter Anatoly B. , Vasilets Victor N. , Fridman Alexander 
Published: April 2008

AbstractAn emerging field of plasma medicine is discussed, where non‐equilibrium plasmas are shown to be able to initiate, promote, control, and catalyze various complex behaviors and responses in biological systems. More importantly, it will be shown that plasma can be tuned to achieve the desired medical effect, especially in medical sterilization and treatment of different kind of skin diseases. Wound healing and tissue regeneration can be achieved following various types of plasma treatment in a multitude of wound pathologies. Non‐equilibrium plasmas will be shown to be non‐destructive to tissue, safe, and effective in inactivation of various parasites and foreign organisms.magnified image
Localised attitudes matter: a study of sickness absence in Sweden
Authors: Haugen Katarina , Holm Einar , Lundevaller Erling , Westin Kerstin 
Published: April 2008

AbstractThe central issues explored in this article are the importance of geographical location in explaining the attitudes of individuals, and the interplay between these attitudes and overt behaviour. The context is as follows: In the late 1990's, sick‐listings in Sweden underwent a substantial increase, causing the public expenses for the general sickness insurance to soar. Moreover, the extent of the usage of the insurance was found to vary significantly across different regions within the country. This development of the sickness insurance generally, and the regional differences specifically, have since been the subject of an intense debate. Differences and/or changes in attitudes toward sick leave within the population have been proposed as possible reasons for the regional variations. Much of the discussion has, however, been based on speculative arguments rather than empirical studies. Using data from a survey conducted in 2005, this research explores whether geographical location influences individual attitudes toward sick leave, and whether these attitudes in turn influence the sickness absence of individuals. The data are analysed using factor analysis, ordinary linear regressions and logistic regressions. The results provide some support for the idea that geographical factors matter to individual attitudes, and that variation in these attitudes is in turn associated with propensity for sickness absence. Copyright © 2008 John Wiley & Sons, Ltd.
SIMS and Raman studies of Mg‐doped InN
Authors: Davydov V. Yu. , Klochikhin A. A. , Smirnov M. B. , Kitaev Yu. E. , Smirnov A. N. , Lundina E. Y. , Lu Hai , Schaff William J. , Lee H.‐M. , Lin H.‐W. , Hong Y.‐L. , Gwo S. 
Published: April 2008

AbstractRaman and SIMS studies of Mg‐doped InN films with a Mg content from NMg = 3.3 × 1019 to 5.5 × 1021 cm–3 are reported. Lattice dynamics of hexagonal InN with substitutional impurities and vacancies has been investigated theoretically and calculated Raman spectra were compared with experimental ones. It is concluded that Raman spectroscopy is a good tool for quantitative characterization of Mg‐doped InN. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excitonic spin relaxation in GaN
Authors: Brimont C. , Gallart M. , Crégut O. , Hönerlage B. , Gilliot P. 
Published: April 2008

AbstractBy performing non‐degenerate pump‐probe experiments, we study the relaxation dynamics of spin‐polarized A and B excitons in wurtzite epitaxial GaN. By analyzing the differential reflection of the two circularly polarized probe components, we extract characteristic times of the different spin relaxation processes. We show that the spin relaxation of the exciton as a whole is negligible in regard to the spin relaxation of the individual carriers. We determined Te = 15 ps for the electron in the conduction band, Thh = 5 ps, and Tlh = 1.5 ps for the heavy hole and for the light hole, respectively. The quite long HH relaxation time can be related to the band structure in which the degeneracy between different spin valence bands is lifted. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)