bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quality changes in fresh‐cut celery as affected by heat treatment and storage
Authors: Viña Sonia Z , Osornio María M López , Chaves Alicia R 
Published: April 2007

AbstractThis work was intended to investigate the effect of thermal treatment (by immersion or heated air) on quality attributes of pre‐cut celery stored at 0 °C for 21 days. The evolution of organoleptic characteristics, weight loss, surface color, chlorophyll content, texture and microbiological counts were determined. Quality of cut celery mostly maintained its initial level up to 14 days at 0 °C, regardless of the treatment applied. The control and heated‐air‐treated samples experienced a similar evolution of surface color, chlorophyll content, texture and microbial counts. There was a slight advantage of the heated air treatment compared to the control, as measured by sensory parameters. The immersion treatment allowed a better retention of the original color and the total chlorophyll content of pieces. However, after 14 days at 0 °C, a more noticeable tissue softening along with rapid microbial development was observed. Copyright © 2007 Society of Chemical Industry
Mass spectrometry‐based “omics” technologies in cancer diagnostics
Authors: Zhang Xuewu , Wei Dong , Yap Yeeleng , Li Lin , Guo Siyuan , Chen Feng 
Published: April 2007

AbstractMany “omics” techniques have been developed for one goal: biomarker discovery and early diagnosis of human cancers. A comprehensive review of mass spectrometry‐based “omics” approaches performed on various biological samples for molecular diagnosis of human cancers is presented in this article. Furthermore, the existing and potential problems/solutions (both de facto experimental and bioinformatic challenges), and future prospects have been extensively discussed. Although the use of present omic methods as diagnostic tools are still in their infant stage and consequently not ready for immediate clinical use, it can be envisaged that the “omics”‐based cancer diagnostics will gradually enter into the clinic in next 10 years as an important supplement to current clinical diagnostics. © 2007 Wiley Periodicals, Inc., Mass Spec Rev
Myelinated nerve endings in human skin
Authors: Provitera Vincenzo , Nolano Maria , Pagano Angela , Caporaso Giuseppe , Stancanelli Annamaria , Santoro Lucio 
Published: April 2007

AbstractWe used immunohistochemical techniques and confocal microscopy to study the morphometry of myelinated nerve endings in glabrous and hairy skin. A total of 30 healthy volunteers took part in this study designed to assess the possibility of obtaining reliable information on myelinated fibers using samples of hairy skin and to determine whether differences exist between myelinated terminations from different sites. We obtained consistent information on cutaneous myelinated terminations using hairy as well as glabrous skin samples. Myelinated endings from hairy and glabrous skin differ in density and distribution. However, from a comparison of our findings with data from nerve biopsy studies, we conclude that all cutaneous myelinated terminations are thinner terminal branches of large myelinated Aβ fibers, whereas cutaneous terminations of small myelinated Aδ fibers lose their myelin before entering the dermis and become indistinguishable from C‐fiber terminations. The classic criteria, based on fiber size, used to distinguish myelinated fiber subgroups in sensory nerves are therefore not suitable for identifying myelinated terminations in the skin. Muscle Nerve, 2007
Axial myopathy due to primary amyloidosis
Authors: Friedman Yael , Paul John T. , Turley Jean , Hazrati Lili‐Naz , Munoz David 
Published: April 2007

AbstractA 74‐year‐old man presented with progressive weakness involving only his back muscles. Serum protein electrophoresis revealed the presence of a monoclonal gammopathy. Muscle biopsy of affected muscles demonstrated amyloid light chain deposition surrounding individual muscle fibers as well as in the walls of blood vessels in association with vasculitis. Selective involvement of axial muscles in isolated amyloid myopathy has not been previously described. We report the occurrence of axial myopathy with associated vasculitis as a presenting feature of primary (AL) amyloidosis. Amyloidosis should be considered in the differential diagnosis of focal myopathies, since the condition may be responsive to chemotherapy. Muscle Nerve, 2007
A novel missense mutation in the caveolin‐3 gene in rippling muscle disease
Authors: Lorenzoni Paulo J. , Scola Rosana H. , Vieira Natassia , Vainzof Mariz , Carsten Ana L. M. , Werneck Lineu C. 
Published: April 2007

AbstractRippling muscle disease (RMD) is a benign myopathy with symptoms and signs of muscular hyperirritability. We report a 17‐year‐old patient who presented with muscular hypertrophy, local mounding on percussion, and a rippling phenomenon. Needle electromyography showed electrical silence during the rippling phenomenon. Muscle protein immunohistochemical analysis showed a partial deficiency of caveolin‐3. Molecular analysis revealed a novel heterozygous A>C transition at nucleotide position 140 in exon 2 of the caveolin‐3 gene. We associated this novel mutation with RMD. Muscle Nerve, 2007
The effect of ultraviolet radiation on the physical properties of stabilised poly (vinyl chloride)
Authors: Khalifa B. A. , Morsi S. E. , Khalifa W. M. , Barsoum S. 
Published: April 2007

AbstractThe electrical and physical properties of unstabilised and stabilised poly(vinyl chloride) (PVC) have been measured before and after ultraviolet irradiation. The results showed that the percentage changes in properties can be correlated with the structure of stabiliser added to the polymer.
The supermolecular structures found in cured epoxy resins
Authors: Aspbury Peter J. , Wake William C. 
Published: April 2007

AbstractThe work arose from the need to explain the beneficial effect of post‐curing at an elevated temperature on the strengths of lap‐shear joints made with amine‐cured epoxy resins. Supermolecular structures were imaged by several electromicroscopy techniques, usually at 100,000 X. Three, if not four, stages of supermolecular structure were made visible. (i) A phase‐contrast image of 1.3 to 2.1 nm diameter which are probably stacked residues of bisphenol A. The d‐spacing seen in the diffracting mode of the microscope probably arises from within this structure. (ii) A nodular structure of ca. 5 nm. (iii) Aggregates of nodules of ca. 17 nm rising to 40 n m on post‐cure. These dimensions were obtained from cumulative distributions of sizes based on photodensitometer records from the electron‐micrograph negatives. Aggregate dimensions vary with curing agent and state of cure although minor variations occur with specimen preparation.
A thermoanalytical study of the cure characteristics of an epoxy resin system
Authors: Barton John M. 
Published: April 2007

AbstractRates and extents of cure at different times and temperatures are determined for a modified epoxy resin system and related to gel time measurements. An empirical equation based on time‐temperature superposition determines cure time as a function of degree and temperature of cure. The dependence of glass transition temperature on degree of cure, and heat capacity measurements on the cured resin, are discussed.
What information will differential scanning calorimetry give on glassy polymers?
Authors: Richardson Michael J. , Savill Norman G. 
Published: April 2007

AbstractThe heat capacity of an amorphous polymer is insensitive to molecular and processing variables except in the glass transition region. Here DSC shows a variety of potentially confusing curves that result from a coupling of instrumental‐ and sample‐based rate effects. The curves can be simply analysed to give true glass temperatures that characterise the method of glass formation.
Some applications of ultra‐violet microscopy to polymers
Authors: Billingham Norman C. , Calvert Paul D. , Knight Jeremy B. , Ryan Timothy G. 
Published: April 2007

AbstractThe experimental requirements for ultraviolet and fluorescence microscopy are briefly discussed. The application of these techniques to polymers usually depends upon the use of some form of staining reagent to develop contrast within the polymer and three variations of this principle are described. In the first, ultraviolet absorbing or fluorescent additives are monitored during spherulitic crystallisation of a polymer with quantitative results which demonstrate rejection of the additive by the crystalline polymer and allow the diffusion coefficient for the additive in the molten polymer to be estimated. In the second application, the equilibrium distribution of absorbing additives after crystallisation is used to reveal crystallinity variations within the sample and to study the influence of non‐crystallisable fractions upon these variations. Finally, reaction of carbonyl groups, with fluorescent or absorbing reagents, in oxidised polymers, has been investigated as a way of revealing uneven oxidation in polypropylene.
General expressions of average molecular weights in condensation polymerisation of polyfunctional monomers
Authors: Durand Dominique , Bruneau Claude M. 
Published: April 2007

AbstractA new method, using the propagation expectation defined by Case, is presented to compute directly and simply the general expressions of average molecular weights for condensation polymerisation of polyfunctional monomers. In particular, the weight average molecular weight in systems composed of monomers endowed with both A and B coreactive functional groups is derived.
The role of liquid crystals in the formation of graphitizable carbons (cokes)
Authors: Atkinson Colin J. , Lander Jacqueline R. , Marsh Harry 
Published: April 2007

AbstractThe formation of cokes and graphites proceeds via the creation from the isotropic fluid phase of carbonization of pitch and coal, of lamellar nematic liquid crystals or mesophase. This anisotropic fluid, deformable mesophase, develops as spheres within which constituent molecules are stacked parallel to an equatiorial plane. This type of structure facilitates coalescence to a coherent mass which eventually forms a graphitisable carbon. The ‘onion‐skin’ structure of mesophase spheres cannot so coalesce. Different optical textures of cokes and graphites owe their origin to different chemical reactivities and fluidities of mesophase, the lower the fluidity the smaller the size of the optical texture. Mesophase from lameller molecules is compared with conventional rod‐like nematic liquid crystals. Structures in needle‐cokes, metallurgical coke, coke from solvent refiend coal and carbon fibre from pitch are discussed in terms of formation and properties of lamellar nematic liquid crystals.
Calorimetric determination of polymerisation conversion in a large laboratory reactor
Authors: Nilsson Holger , Silvegren Christer , Törnell Bertil 
Published: April 2007

AbstractA calorimetric measuring system for continuous recording of rate of reaction and conversion in a 14 1 polymerisation reactor has been developed. The reactor was jacketed and thermostated with circulating water. The measuring signals to the calculating unit represented the temperature difference between inlet and outlet water, the water flow and the heat losse from reactor to the environment. The measuring system was constructed to calculate correctly the conversion even if the heat losses to the environment changes during the reaction. The applicability of the reactor system was demonstrated by its use in suspension polymerisation of vinyl chloride.
Synthesis, properties, and solvatochromism of 1,3‐dimethyl‐5‐{(thien‐2‐yl)‐[4‐(1‐piperidyl) phenyl]methylidene}‐(1H,3H)‐pyrimidine‐2,4,6‐trione
Authors: El‐Sayed Mohamed , Spange Stefan 
Published: April 2007

AbstractA new merocyanine dye, 1,3‐Dimethyl‐5‐{(thien‐2‐yl)‐[4‐(1‐piperidyl)phenyl]methylidene}‐ (1H, 3H)‐pyrimidine‐2,4,6‐trione 3, has been synthesized by condensation of 2‐[4‐(piperidyl)benzoyl]thiophene 1 with N,N′‐dimethyl barbituric acid 2. The solvatochromic response of 3 dissolved in 26 solvents of different polarity has been measured. The solvent‐dependent long‐wavelength UV/Vis spectroscopic absorption maxima, vmax, are analyzed using the empirical Kamlet–Taft solvent parameters π* (dipolarity/polarizability), α (hydrogen‐bond donating capacity), and β (hydrogen‐bond accepting ability) in terms of the well‐established linear solvation energy relationship (LSER):

The solvent independent coefficients s, a, and b and (vmax)0 have been determined. The McRae equation and the empirical solvent polarity index, ET(30) have been also used to study the solvatochromism of 3. Copyright © 2007 John Wiley & Sons, Ltd.
Titanium dioxide photoinduced degradation of some pesticide/fungicide precursors
Authors: Kuehr Ivana , Núñez Oswaldo 
Published: April 2007

AbstractFive‐membered nitrogen heterocycles (pyrrole, imidazole and 1,2,4‐triazole) have been degraded using titanium dioxide and simulated solar radiation at pH = 8. The degradations followed a simple Langmuir–Hinshelwood mechanism. Accordingly, the adsorption equilibrium constants K of the heterocycles on the titanium dioxide surface and the rate constants k of degradation of the heterocycle–catalyst adduct have been obtained experimentally. While the K values decrease with heterocycle pKa, the k values increase with increasing pKa. Therefore, apparently, the rate constant depends on the availability of the electron pair on nitrogen, but at the same time the electron pair repulsion induced by the negatively charged titanium dioxide surface at pH = 8 causes a reverse effect in the adsorption equilibrium constant. Only in the case of imidazole, where the adsorption equilibrium constant is low enough (K = 0.013 M−1), can the rate constant be approximated to a pseudo‐first‐order rate expression: kobs = Kk. In all other cases, kobs = Kk/(1 + Kheterocycle). Copyright © 2007 Society of Chemical Industry
Synergistic interaction of physcion and chrysophanol on plant powdery mildew
Authors: Yang Xiaojun , Yang Lijun , Wang Shaonan , Yu Dazhao , Ni Hanwen 
Published: April 2007

AbstractThe extract of the plant Rheum officinale Baill, mainly containing the anthraquinones physcion and chrysophanol, is highly active against plant powdery mildew. Experiments were conducted in the laboratory and greenhouse to determine the interaction of the two compounds on cucumber powdery mildew [Sphaerotheca fuliginea (Schlecht.) Poll] and on wheat powdery mildew [Blumeria graminis (DC.) Speer f. sp. tritici Marchal]. Physcion was much more bioactive than chrysophanol against these powdery mildews. There was a significant synergistic interaction between the two compounds on the diseases when the ratios of physcion to chrysophanol ranged from 1:9 to 5:5. The synergistic degree increased with increase in the chrysophanol proportion in the combination. The findings indicate that, in order to ensure constant efficacy of the extract on the disease, both the contents and the proportion of the main active ingredients physcion and chrysophanol have to be determined. Copyright © 2007 Society of Chemical Industry
Distribution and efficacy of drip‐applied metam‐sodium against the survival of Rhizoctonia solani and yellow nutsedge in plastic‐mulched sandy soil beds
Authors: Candole Byron L , Csinos Alexander S , Wang Dong 
Published: April 2007

AbstractThe effects of metam‐sodium application rate on soil residence time, spatial and temporal distributions of methyl isothiocyanate and pest control efficacy were studied in a Georgia sandy soil. Metam‐sodium 420 g L−1 SL was drip applied at rates of 147 and 295 L ha−1 in plastic‐mulched raised beds. Methyl isothiocyanate concentrations in soil air space were monitored from four preselected sites: 10 and 20 cm below the emitter, and 20 and 30 cm laterally away from the emitter at 3, 12, 24, 48, 72, 120 and 240 h after chemigation. A higher rate of metam‐sodium application resulted in higher methyl isothiocyanate concentrations in the soil. Highest methyl isothiocyanate concentrations were found at 20 cm below the emitter, and lowest at 30 cm laterally away from the emitter. Methyl isothiocyanate concentrations decreased with time and distance from the emitter. Lower methyl isothiocyanate concentration × time product values at 20 and 30 cm away from the emitter resulted in lower mortalities of Rhizoctonia solani Kühn and yellow nutsedge (Cyperus esculentus L.). The results demonstrated that methyl isothiocyanate can be delivered at lethal doses with drip‐applied water downward within the beds. Lateral diffusion of methyl isothiocyanate from the point of application did not reach biologically active concentrations to affect the survival of R. solani or yellow nutsedge. Further studies on the lateral distribution of methyl isothiocyanate in sandy soils are needed to circumvent this limitation. Copyright © 2007 Society of Chemical Industry
Dielectric and magnetic properties of citrate‐route‐processed Li–Co spinel ferrites
Authors: Gupta Nutan , Kashyap S. C. , Dube D. C. 
Published: April 2007

AbstractCobalt‐substituted lithium ferrites (with general composition Li0.5–x /2Cox Fe2.5–x /2O4, where x = 0.0, 0.2, 0.4, 0.5 and 0.6) were prepared at lower processing temperatures (∼600 °C) by the citrate route. The single‐phase spinel structure was confirmed by X‐ray diffraction. The average particle size of calcined powders calculated by the Scherrer formula is estimated to be 8–90 nm, whereas an average particle size of ∼20 nm is observed from TEM for Co concentration x = 0.5. Average grain sizes from SEM micrographs of pellets sintered at 1000 °C (1 h) are observed to be 0.5–1 μm, much smaller than the size reported for the standard ceramic method (2.1–6.8 μm). The experimental density is observed to be 3.59–4.47 gm/cm3, which is greater than 85% of the densities evaluated from XRD. Compared with the standard ceramic method, lower dielectric constant (10–103) and higher dc resistivity (105–1010 Ω cm) is observed for Li–Co ferrites prepared by the citrate route. Improved magnetic properties, such as higher saturation magnetization (38–79 emu g–1) and Curie temperature (535 to 620 °C) are also investigated for the citrate‐route‐processed samples. These results demonstrate promising features of Li–Co ferrites in microwave applications. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Physical properties and photoelectrochemical characterization of SrPbO3
Authors: Hadjarab B. , Saadi S. , Bouguelia A. , Trari M. 
Published: April 2007

AbstractSrPbO3–δ is n‐type, narrow‐bandgap semiconductor crystallizing in a distorted perovskite structure. The electrical conductivity varies with temperature but in a nonmonotonic manner. At high temperatures, the thermal evolution of the conductivity follows an Arrhenius‐type law with an activation energy of 0.11 eV attributed to mixed valency states Pb4+/2+ and leading to a dielectric constant of 13.6. The sign of thermopower S is negative, indicating that the mobile carriers are electrons, which is ascribed to oxygen extraction. The electron hopping occurs between similar electronic localized states in the vicinity of the mobility edge with an electron mobility of ∼10–2 m2 V–1 s–1 that is thermally activated. The variation S (T) suggests a finite density of states at the Fermi level. At low temperatures, the conduction mechanism changes to a variable‐range hopping. The weak hybridization of the Pb–O bond, due to the tilting of PbO6 octahedra, lowers the energy of the antibonding conduction band resulting in a small optical gap Eg. The Eg value was found to be 1.76 eV and the transition is directly allowed; a further indirect transition occurs at 0.79 eV. The flat potential Vfb measured from the Mott–Schottky plot was equal to –0.38 VSCE. The upper valence‐band edge, located at 6.8 eV below vacuum, is made from mainly the O:2p orbital, whereas the conduction band consists of empty 6s levels. The linear plot log real capacitance‐log frequency indicates a capacitive behavior. The relevance of 6s conduction band to the performance of semiconducting photoelectrodes will be discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A numerical method for the analysis of nonlinear carrier diffusion in cylindrical semiconductor optoelectronic devices
Authors: Shishodia M. S. , Sharma A. , Reddy G. B. 
Published: April 2007

AbstractA numerical method to simulate radial distribution of carrier concentration in cylindrical semiconductor optoelectronic devices is presented. Method is based on the collocation principle and employs sinusoidal functions as the basis. The two approaches, evolutionary as well as iterative are presented for solving the governing differential equations. Coordinate transformation is shown to be extremely advantageous for enhancing the computational efficiency. To illustrate the versatility of the method, several examples where the geometry demands different sets of boundary conditions are included. The application of this technique for analyzing carrier concentration profiles in cylindrical optoelectronic devices, for the first time, has demonstrated its multi‐utility in addition to the established ability in solving electromagnetic wave equation. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excitons in ZnO/Zn1–xMnxO quantum wells
Authors: Tchelidze T. , Chikoidze E. , Kereselidze T. , Dumont Y. 
Published: April 2007

AbstractIn order to estimate the perspectives of using ZnO/Zn1–x Mnx O quantum wells for reliable high temperature ferromagnetism (specially for increasing Curie temperature in this structure) we investigate excitons in ZnO/Zn1–x Mnx O quantum wells. The existence of weak built‐in electric field is investigated. Electric field and Coulomb interaction is accounted by means of direct diagonalization. Calculations showed weak dependence of exciton binding energy on well width. Electric field only slightly increases the distance between electron and hole. It rotates ground state excitons and aligns them along the field. Calculations also showed increase of ground state exciton lifetime with increasing well width. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phonon‐ and electron‐related far‐infrared absorption in CdTe and ZnTe crystals
Authors: Brazis R. , Nausewicz D. , Raguotis R. 
Published: April 2007

AbstractConstants characterising the efficiency of far‐infrared (FIR) photon coupling to phonon sum and difference combination processes are elucidated from existing experimental data in CdTe and ZnTe crystals. Two‐phonon difference processes are concluded to play leading role in the FIR absorption in the range of 1–4 THz. LO phonon band population inversion relative to LA band at the same phonon momentum is revealed in electric field acting on the conduction‐band electrons using Monte Carlo method. Radiative decay of acumulated LO phonons and daughter TO and LA phonons is considered. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A simple method for inference on an overall effect in meta‐analysis
Authors: Brockwell Sarah E. , Gordon Ian R. 
Published: April 2007

AbstractThe random effects approach in meta‐analysis due to DerSimonian and Laird is well established and used pervasively. It has been established by Brockwell and Gordon that this method, when used for confidence intervals, leads to coverage probabilities lower than the nominal value. A number of alternatives have been proposed, but these either have the defect of iterative and complicated calculation, or deficient coverage. In this paper we propose a new approach, which is simple to use, and has coverage probabilities better than the alternatives, based on extensive simulation. We call this approach the ‘quantile approximation’ method. Copyright © 2007 John Wiley & Sons, Ltd.