bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectroscopical Investigation of Ski Base Materials
Authors: Fischer Jorg , Wallner Gernot M. , Pieber Alois
Published: May 2008

Summary: Raman spectroscopy was applied to perform a comprehensive morphological analysis of polyethylene (PE) ski base materials at different processing levels. The morphological characterization included determination and evaluation of Raman spectra and examination of the crystallinity values by differential scanning calorimetry (DSC). A good agreement between Raman and DSC crystallinity fractions was obtained, thus corroborating the Raman spectroscopy approach. While for the PE grade with the lowest average molar mass no significant morphological changes due to processing from the raw material via the extruded film to the post‐treated film was found, higher molar mass PE grades exhibited a decrease of crystallinity, but an increase of the amorphous fraction along the process chain.
Investigation of Lignins by FTIR Spectroscopy
Authors: Derkacheva Olga , Sukhov Dmitry
Published: May 2008

Summary: Applying special computer mathematical treatments to increase resolution of experimental spectra there were established a set of stable characteristic bands for isolated softwood lignins. In the 740–1620 cm−1 spectral range the band maximum positions did not change but values of bandwidths and peak intensities were varied in limits 15% and 32%. After analysis of the infrared spectra of 30 investigated samples a softwood lignin spectral model was constituted. This model allowed to clear discrepancies in the bands parameters of different mild isolated (lignins of Bjorkman, Pepper and Freudenberg), dioxane and technical lignin spectra. It was helpful for studying lignin structure changes during degradation procedures.
Solid‐State NMR Studies of Polysaccharide Systems
Authors: Spěváček Jiří , Brus Jiří
Published: May 2008

Summary: Two polysaccharide systems were studied by solid‐state NMR methods: (i) Chitin/glucan complexes. The 13C NMR spectra have shown that in samples isolated from the mushroom Pleurotus sp., the glucan content was always higher in stems than in pilei. While carbonyl lineshape in complex isolated from Aspergillus niger mycelium shows similar hydrogen bonding as in neat chitin, a significantly higher amounts of hydrogen bonding between carbonyl groups of chitin and hydroxy groups of glucan was found in complexes isolated from Pleurotus sp. (ii) Biodegradable starch/polycaprolactone (PCL) blends. From the relaxation times T1(H) and T1ρ(H) it follows that blends starch/PCL, starch/ester oligomers and starch formate/ester oligomers are phase‐separated even on the scale 20–110 nm. On the contrary, starch formate/PCL blend is phase‐separated on the scale 1–9 nm but homogeneously mixed on the scale 20–90 nm. Therefore formylation of starch significantly improves its miscibility with PCL.
Phase Behaviour of Poly(styrene‐co‐methacrylic acid)/ Poly(styrene‐co‐N,N‐dimethylacrylamide)/Poly(styrene‐co‐4‐vinylpyridine) Ternary Blends by DSC and FTIR
Authors: ElMiloudi Khaled , Djadoun Said
Published: May 2008

Summary:we have investigated by DSC and FTIR the miscibility and phase behaviour of binary and ternary blends of different ratios of poly(styrene‐co‐methacrylic acid) containing 15 mol% of methacrylic acid (SMA15) with poly(styrene‐co‐N,N‐dimethylacrylamide) containing 17 mol% of N,N,‐dimethylacrylamide (SAD‐17) and poly(styrene‐ co‐4‐vinylpyridine) containing 15 mol% of 4‐vinylpyridine. SMA15 is miscible with both SAD17 and S4VP15 and interacts more strongly with S4VP15 than with SAD17 as evidenced by the positive deviations from linear average line observed with these blends and the appearance of new bands in the 1800–1550 cm−1 region. This behaviour is known as ΔK effect. The FTIR study confirms that though the specific intermolecular interactions that occurred with each pair of the SMA15/S4VP15 and SMA15/SAD17 binary components are of different strength, they still exist in the ternary blend. Even though the three binary polymer pairs are individually miscible, the ternary system of SMA15/S4VP15/SAD17 exhibits only partial miscibility with small loop of immiscibility due to a significant ΔK effect. These results obtained by DSC and FTIR are in a fair agreement with theoretical prediction applying the Painter‐Coleman association model.
In situ Fluorescence Study of Swelling, Sorption and Desorption Processes in and out of PAAm Gels
Authors: Evingur Gulşen Akın , Karslı Kadir , Pekcan Onder
Published: May 2008

Summary: Small molecule sorption and desorption in and out of polyacrylamide (PAAm) gels were studied at various temperatures. Pyranine (Py) dissolved in water used as a probe. Fluorescence emission intensity, Ip from Py was monitored for studying sorption and desorption processes. Scattered light intensities, Isc from PAAm gel was also monitored to observed structural variations during sorption and desorption process. Li‐Tanaka model was applied to produce the swelling time constants, τc and sorption coefficients, Dc for the swelling processes. On the other hand, sorption and desorption processes were studied and coefficients were produced by using Fickian model. Related activation energies were also calculated from the corresponding physical processes.
Development of Methods to Determine the Infrared‐Optical Properties of Polymer Films
Authors: Oreski Gernot , Tscharnuter Daniel , Wallner Gernot M.
Published: May 2008

Summary: In this paper, two methods for the determination of infrared optical properties of thick polymer films, based on FTIR spectroscopy, were implemented and used. Complex index of refraction data were generated for various ethylene copolymer films. Transmittance and reflectance spectra were measured in the mid infrared range using a gold‐coated 100 mm‐diameter integrating sphere. For the investigated films n and k values ranging from 1.3 to 1.6 and from 10−4 to 0.25 were determined, respectively. Regarding n, a good agreement was obtained for both methods, the transmittance/reflectance procedure (T/R method) used for transparent and semitransparent regions, and Single Substractive Kramers‐Kronig (SSKK) algorithm applied for non‐transparent regions. The highest k values were determined for the CH2 stretching vibration. The k values are dependent on comonomer content and film thickness. The combination of both methods allows for an accurate determination of n and k in the entire IR region relevant for solar application.
Monitoring of the Sol‐Gel Synthesis of Organic‐inorganic Hybrids by FTIR Transmission, FTIR/ATR, NIR and Raman Spectroscopy
Authors: Fischer D. , Pospiech D. , Scheler U. , Navarro R. , Messori M. , Fabbri P.
Published: May 2008

Summary: The sol‐gel synthesis of organic‐inorganic hybrids based on triethoxysilane‐ terminated poly(ethylene oxide) and tetraethylorthosilicate was monitored in‐situ using three spectroscopic methods (FTIR/ATR, Raman, NIR). These spectroscopic methods allow in‐situ monitoring of the evolution of hybrid materials starting from the modification of the polymer and the early steps of hydrolysis up to the network formation. By application of 29Si solid‐state NMR spectroscopy the assignment and quantification of the Raman bands to different end groups and different cross‐linking states was made. The sol‐gel reaction was also followed by in‐line NIR spectroscopy. A multivariate data analysis was accomplished to obtain a conversion‐time curve. Furthermore, we investigated spin‐coated films on wafers using FTIR transmission spectroscopy.
Optical Spectra of Polygermane/Mesoporous Silica Nanocomposites
Authors: Ostapenko Nina , Kozlova Nata , Suto Shozo , Nanjo Masato , Mochida Kunio
Published: May 2008

Summary: The monitoring of poly(di‐n‐hexylgermane) (PDHG) optical spectra in a variety of structures ranging from a bulk film to a nanosize polymer confined into a nanopore of SBA‐15 was performed using the fluorescence and fluorescence excitation spectra in the temperature range from 5 to 240 K as well as the absorption and FTIR spectra at room temperature. The observed data were compared with those obtained for poly(di‐n‐hexylsilane). It was shown that PDHG film absorption and fluorescence spectra strongly depend on the polymer thickness and consist of a number of bands which were assigned to centers with different amount of trans‐ and gauche‐ conformers of the polymer chains. Conformations of the polymer chains found in a thin film and in a 10 nm pore are similar while differing from the conformations of a thick film. Optical spectra of the confined PDHG are blue‐shifted relative to those of a thin film. The PDHG polymer chain conformation becomes disordered with the decrease of the polymer film thickness and the nanopore size from 10 to 6 nm.
Assessment of Beam Damage in Polymers Caused by in situ ESEM Analysis using IR Spectroscopy
Authors: Zankel Armin , Chernev Boril , Brandl Christian , Poelt Peter , Wilhelm Peter , Nase Michael , Langer Beate , Grellmann Wolfgang , Baumann Hans Joachim
Published: May 2008

Summary: The environmental scanning electron microscope (ESEM) enables in situ analyses of non‐conducting samples such as polymers, thus allowing microscopic phenomena to be correlated to macroscopic measurement data. Unfortunately, irradiation of polymers with electrons always causes beam damage1 and it is unclear whether this damage could influence the outcome of the experiments. The amount of beam damage in polymers is mainly determined by the electron dose, which is a function of the probe current, the irradiation time, the irradiated area and the type of imaging gas used. The beam damage during in situ tensile tests of peel films was assessed using Fourier transformed infrared spectroscopy (FTIR). The band at 965 cm−1 turned out to be significant for the estimation of beam damage in this material, which was verified by long‐term measurements. The measurements were performed in an ESEM Quanta 600 FEG at parameters comparable to the prior in situ tensile tests. Additional measurements were performed in a Quanta 200 at parameters typical of in situ investigations. Again, the out‐of‐plane trans CH wag at 965 cm−1 turned out to be significant for beam damage and was used as an indicator for beam damage (dehydrogenation) for this type of material.
Orientation Dependent FT Raman Microspectroscopy on Hemp Fibers
Authors: Kovur S. K. , Schenzel K. , Diepenbrock W.
Published: May 2008

Summary: FT Raman microspectroscopy was used for polarization experiments on strained hemp fibre cells. The cellulosic plant fibers were macerated with alkaline and enzymatic solutions. Those cleaned and refined single fiber cells were subjected to micro tensile tests as well as to polarization measurements under the FT Raman microscope. Mechanical parameters of the fiber cells (e.g. E‐modulus) were determined and changes in orientation of the (COC) structure units of the cellulose were considered with respect to fiber stress and molecular fiber structures. Intensity ratios R1 and R2 calculated on the polarized micro FT Raman spectra of the strained fibers describe the order parameter 〈P2〉 and 〈P4〉 allowing the quantitative determination of the orientation of the structure units (COC) of fiber cellulose with respect to the fiber cell axis.
The Structure of Aminopropylsiloxane Polymerized in DC Electric Field
Authors: Bistričić Lahorija , Volovšek Vesna
Published: May 2008

Summary: The Raman spectra of aminopropylsiloxane (APS) polymerized on PVC substrate in DC electric field were measured to study the structure of deposited films. The modelling of low wavenumber Raman spectra was achieved using contribution of acoustic phonons, intramolecular vibrations as well as optical phonons related to librational motions of ladders. Results suggest that electric field influences the orientations of ladders increasing thus the degree of order in microdomains.
Indirect Measurement of the Cooperative Hydrogen Bonding of Polymers Using NMR Quadrupole Relaxation and PFG Methods
Authors: Kříž Jaroslav , Dybal Jiří
Published: May 2008

Summary: A general method of measurement of polymer hydrogen bond (HB) cooperativity using a low‐molecular weight model ligand named marker and two independent methods of 2H NMR is presented. As marker, a deutero‐compound chemically similar to the functional groups of one of the polymers is used, e.g. pyridine‐d5 in the investigated interaction of poly(4‐vinylpyridine) with poly(4‐vinylphenol) or acetic acid‐d4 in the interaction of polyacrylic acid with poly(4‐vinylphenol) reported here. The method is based on the fact that a substantial fraction of the marker, originally bound to the groups of one of the polymers, is liberated by the cooperative interaction between the two polymers. For the establishment of the fraction of the bound marker before and after mixing the polymers, 2H NMR quadrupolar relaxation or 2H PFG NMR diffusion measurement can be used with comparable precision. In both these methods, the results must be normalized to a standard viscosity using the relaxation or diffusion of an added inert compound such as CDCl3.
Fourier‐Filtering Methods of Interference‐Patterned Spectra in Multivariate Calibration and Prediction for Sample Identification and Thickness Determination
Authors: Jeszenszky Éva , Kocsányi László , Barócsi Attila , Richter Péter
Published: May 2008

Summary: Determining the thickness or identification of polymer materials with building a multivariate calibration model is based on the near infrared spectral information of the material. The spectrum of a thin plastic sheet is modulated by the interference of multiply reflected beams from the boundary surfaces and causes a disturbing signal component. On one hand, this yields unidentifiable samples or introduces large errors in the sample prediction set. On the other hand, interference‐patterned spectra have to be excluded from the calibration set. Fourier‐transformation of an interference‐patterned spectrum vs. wave number leads to a Fourier‐spectrum as a function of the optical path length (OPL) containing a well recognizable interference peak. After replacing these interference‐components and performing an inverse Fourier‐transformation, the spectra can be used for calibration or prediction. Two types of replacing were studied: the spline‐interpolation on Fourier‐ spectrum vs. OPL and a novel method based on linear approximation between Fourier‐spectra and thickness values. The effectiveness of each filtering method was tested on low‐density polyethylene and polypropylene sheets.
Interactions and Temperature Transitions of Ethylene Oxide – Propylene Oxide – Ethylene Oxide tri‐block Copolymers in Water Media
Authors: Schmidt Pavel , Dybal Jiří
Published: May 2008

Summary: ATR FTIR spectra of two ethylene oxide – propylene oxide – ethylene oxide (EO)n‐(PO)m‐(EO)n tri‐block copolymers (Pluronics) with different lengths of the EO blocks were investigated in water media at various temperatures. The observed wavenumber shifts and intensity changes of the bands of different chemical groups of polymers and of water molecules served as a basis for the estimation of structural changes and interactions of polymers with the surrounding water molecules. Two types of such interactions, i.e. hydrophilic (ether group – water) and a hydrophobic (methyl group – water) are detected. In the copolymer with shorter length of the EO blocks, an interchain H2O bridge in a liquid crystalline phase was discovered and confirmed by ab initio calculations. A model for the structural changes during the temperature transitions is specified.
Absorption Study of Norfloxacin – DNA Interaction
Authors: Vijan L. E. , Conci M.
Published: May 2008

Summary: Norfloxacin, a quinolone antibacterial reagent, has been studied with respect to its binding to calf thymus DNA using absorption spectroscopy. We examined the self‐association of the norfloxacin, in order to determine the molar absorption coefficient of the monomer, the molar absorption coefficient of the dimer and the dimerization constant. We also examined the interaction of norfloxacin with DNA by measuring the number of binding sites per DNA segment and the binding constant. Hypochromism, broadening of the envelope and a red‐shift in the drug absorption region are apparent for the norfloxacin that bound to DNA. The results were rationalized taking into account both self‐association of the drug and the cooperatively effects, in terms of several literature models, Benesi‐Hildebrand, Scott, Scatchard, Schwarz and Watanabe‐Schwarz.
Spectroscopic Study of Hedamycin – DNA Interaction
Authors: Vijan L.E. , Raducu A.
Published: May 2008

Summary: Binding of hedamycin, a member of the antitumour antibiotics pluramycin class, to calf thymus DNA has been studied using UV‐Vis absorption spectroscopy. The results have been rationalized in terms of several literature models: Wolfe, Benesi‐Hildebrand, Scott and Scatchard.
Investigations on Multilayer Films: Electron Microscopy and Infrared Spectroscopy – Possibilities and Limitations
Authors: Chernev B. , Belegratis M. R. , Ingolič E.
Published: May 2008

Summary: The study of multilayer films has become an important issue, since every year improved materials are produced. They have to be optimally designed in order to enable the maintenance of aroma, taste and nutritional value of the goods. This is primarily achieved by the use of special laminated films, additives and oxygen barriers. In addition, ecological and economical factors force the industry forwards to create more environmental‐friendly and cheaper films. In this study, two multilayer packaging films differing in the layer and barrier composition are examined with light microscopy (LM), transmission electron microscopy (TEM) and Fourier transformed infrared (FTIR) microspectroscopy: LM gives the number and the thickness of the layers, but there is no information about the chemical composition and the coatings. FTIR and Raman Spectroscopy enable the chemical characterization of the identified layers, but the lateral resolution is restricted in the µm range. TEM visualizes the important characteristics (coatings, filler particles) and enables the detection of inorganic fillers (EELS, EDX), but the organic components cannot be analyzed. Therefore, the use of complementary techniques is crucial in order to achieve a complete analysis of multilayer foils.

Special attention was paid on the preparation procedure, since ultrathin sections are an important prerequisite for TEM observation and there is little known about the “perfect” preparation of multilayer films.
An FTIR Study on the Solid‐State Copolymerization of bis(2‐hydroxyethyl)terephthalate and Poly(butylene terephthalate) and the Resulting Copolymers
Authors: Ziari Maya , van Asselen Otto , Jansen Martijn , Goossens Han , Schoenmakers Peter
Published: May 2008

Summary: The first aim of this work was to study the solid‐state copolymerization (SSP) of bis(2‐hydroxyethyl)terephthalate (BHET) with poly(butylene terephthalate) (PBT) by FTIR spectroscopy. The development of the chemical microstructure during the SSP‐reaction was examined as a function of the BHET content, showing the different regimes. The thermal behaviour of the resulting copolymers with different BHET contents was also investigated during cooling using infra‐red dynamic spectra. For low BHET‐concentrations, only crystallization of PBT‐sequences was observed, while for high BHET‐concentrations, only crystallization of PET‐sequences was detectable with a cross‐over behaviour for intermediate concentrations.
Simulation of RAFT Dispersion Polymerization in Supercritical Carbon Dioxide
Authors: Jaramillo‐Soto Gabriel , Castellanos‐Cárdenas M. Luz , García‐Morán Pedro R. , Vivaldo‐Lima Eduardo , Luna‐Bárcenas Gabriel , Penlidis Alexander
Published: May 2008

The RAFT radical polymerization of vinyl monomers in supercritical carbon dioxide was modeled using the Predici® simulation package. The sensitivity of polymerization responses on formulation and process variables was analyzed. The simulations were carried out using kinetic and physical parameters corresponding to the polymerization of methyl methacrylate in supercritical carbon dioxide, using AIBN as initiator, at 65 °C and 200 bar, and using values of the addition and fragmentation kinetic rate constants of a “typical” RAFT agent, as reference conditions. This is the first report in the literature addressing the modeling or simulation of RAFT polymerization in supercritical carbon dioxide.

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Potent cell growth inhibitory effects in hepatitis B virus X protein positive hepatocellular carcinoma cells by the selective cyclooxygenase‐2 inhibitor celecoxib
Authors: Xie Huahong , Gao Liucun , Chai Na , Song Jiugang , Wang Jun , Song Zhenshun , Chen Caiping , Pan Yanglin , Zhao Lina , Sun Shiren , Wu Kaichun , Feitelson Mark A. , Liu Jie , Fan Daiming
Published: May 2008

Hepatitis B virus (HBV) X protein (HBx) and cyclooxygenase‐2 (COX‐2) are all playing roles in hepatocellular carcinoma (HCC), but the reversing effects of COX‐2 inhibitors on the neoplastic features caused by HBx protein is still unclear. To further evaluate the therapeutic potential of celecoxib on HBx mediated transformation, HCC cells transfected with HBx gene were treated with COX‐2 selective inhibitor, celecoxib. The amount the main metabolite of COX‐2, prostaglandin E2 (PGE2), was determined by using high sensitivity ELISA. Electron microscope and flow cytometry was used to analyze cell apoptosis and cell cycle distribution. RT‐PCR and Western blot were used to identify the molecules involved in celecoxib induced cell apoptosis. The results showed that celecoxib inhibited cell growth more significantly and also induced more cell apoptosis in HBx over‐expression cells than in control cells. Celecoxib could selectively inhibited COX‐2 expression and PGE2 production. Celecoxib also inhibited p473SerAkt, raf and p53 expression, and induced apoptosis by release of cytochrome c and activation of caspase 9, 3, and 6, which were more remarkably in HBx positive cells than in control cells. These results suggest that celecoxib had potent cell growth inhibitory effects on HBx positive HCC cells mainly through inducing more cell apoptosis, and these findings provide a new insight into the anticancer effects of celecoxib against HBx related HCC. © 2008 Wiley‐Liss, Inc.
Variability of low monthly rainfall in La Plata Basin
Authors: Penalba Olga C. , Vargas Walter M.
Published: May 2008

Water resources management and agriculture planning models require a statistical synthesis of some rainfall features, in particular those representing dry atmospheric conditions. The bigger the basin, the more important these features become, as is the case of the La Plata Basin (LPB).

This paper focuses on the precipitation variability in the large LPB in South America, analysing the number of months per year with low rainfall and the sequences of months with low rainfall, their theoretical distributions and stability, which are needed as input for the models mentioned above.

Long time series are used to analyse the low‐frequency variability and the relative importance of decadal variability. Changes are evident in the number of months per year with low rainfall, with a decrease of about 20% in the period after 1970.

Theoretical distribution models (binomial and geometric) are fitted to these empirical distributions, and the regional variability of the fitting parameters is shown. In practically the entire region, the goodness‐of‐fit of the two theoretical models considered is statistically satisfactory.

The temporal variability of the parameters of the theoretical binomial (p) and geometric (α) distributions is analysed, in excluding sub‐periods of 10 and 5 years, respectively. The results show low‐frequency variability overlapped on a decadal variability, with low homogeneous regional behaviour.

The distribution models have proven to be efficient for frequency adjustments of the rainfall properties studied. These results are an acceptable and necessary input to decision models in LPB. They also make it possible to infer effects of climate change. Copyright © 2008 Royal Meteorological Society
Kinetics of the Anionic Polymerization of Buta‐1,3‐diene Considering Different Reactivities of the cis, trans and vinyl Structural Units
Authors: Tenorio López José A. , Benvenuta Tapia Juan J. , Montiel Maldonado Celestino , Ríos Guerrero Leonardo
Published: May 2008

The anionic solution polymerization of buta‐1,3‐diene was modeled, considering the reactivity of the active sites to be different due to varying geometric configurations. With the first‐order Markov model, expressions for the fraction of active sites and dyad distribution were obtained. The rate constants were determined by fitting to the conversion and dyad experimental data using the nonlinear least squares method. The kinetic model shows that the microstructure and the dyads do not depend on initiator and butadiene concentration but only on rate constants. Without a modifier, the butadiene addition mechanism is entropic; with a modifier, the mechanism changes to entropic‐enthalpic.

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“Living” Radical Polymerization in Tubular Reactors, 2 – Process Optimization for Tailor‐Made Molecular Weight Distributions
Authors: Asteasuain Mariano , Soares Matheus , Lenzi Marcelo K. , Hutchinson Robin A. , Cunningham Michael , Brandolin Adriana , Pinto José Carlos , Sarmoria Claudia
Published: May 2008

“Living” radical polymerization is a relatively new polymerization process that can be used to prepare resins with controlled structures. In this work, a mathematical model developed previously to describe nitroxide‐mediated “living” radical polymerizations performed in tubular reactors is used for the optimization of the process and obtainment of tailor‐made MWDs. Operating conditions and design variables are determined with the help of optimization procedures in order to produce polymers with specified MWDs. It is shown that bimodal and trimodal MWDs, with given peak locations, can be obtained through proper manipulation of the operating conditions. This indicates that the technique discussed in this work is suitable for detailed design of the MWD of the final polymer.

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Effects of changes in intracellular action potential on potentials recorded by single‐fiber, macro, and belly–tendon electrodes
Authors: Arabadzhiev Todor I. , Dimitrov George V. , Chakarov Vichren E. , Dimitrov Alexander G. , Dimitrova Nonna A.
Published: May 2008

Some myopathies are accompanied by abnormal calcium homeostasis. Electromyography (EMG) in such patients shows signs of normal or myopathic EMG when detected by a single‐fiber electrode and abnormally increased values in macro EMG. As calcium accumulation might be accompanied by changes in intracellular action potential (IAP) and muscle‐fiber propagation velocity, we simulated the effects of such changes on motor unit potentials (MUPs) recorded by different kinds of electrodes. We found that: (1) the requirements for what potential can be accepted as a single‐fiber action potential (SFAP) are too rigorous; (2) macro MUP amplitude can increase while SFAP amplitude can decrease when there is an increase in the spatial length of IAP spike; and (3) changes in the second phase of a belly–tendon‐detected MUP or M wave could be used for noninvasive detection of increased IAP depolarizing (negative) after‐potential. Muscle Nerve 37: 700–712, 2008
Amyloidogenic transthyretin Val30Met homozygote showing unusually early‐onset familial amyloid polyneuropathy
Authors: Tojo Kana , Sekijima Yoshiki , Machida Kazuko , Tsuchiya Ayako , Yazaki Masahide , Ikeda Shu‐Ichi
Published: May 2008

We report an amyloidogenic transthyretin (ATTR) Val30Met homozygote showing extremely early‐onset, severe familial amyloid polyneuropathy (FAP). Although homozygotes have been reported to show late‐onset and mild clinical manifestations, detailed analyses of the present and previously reported families suggest that homozygotes have a slightly more severe clinical course than heterozygotes. This is the youngest reported patient with ATTR Val30Met FAP, a condition believed to be attributable to homozygosity of this mutation. The clinical severity is consistent with TTR protein instability. Muscle Nerve, 2008
Changes in Na+ channel expression and nodal persistent Na+ currents associated with peripheral nerve regeneration in mice
Authors: Nakata Miho , Baba Hiroko , Kanai Kazuaki , Hoshi Tomiko , Sawai Setsu , Hattori Takamichi , Kuwabara Satoshi
Published: May 2008

Patients with peripheral neuropathy frequently suffer from positive sensory (pain and paresthesias) and motor (muscle cramping) symptoms even in the recovery phase of the disease. To investigate the pathophysiology of increased axonal excitability in peripheral nerve regeneration, we assessed the temporal and spatial expression of voltage‐gated Na+ channels as well as nodal persistent Na+ currents in a mouse model of Wallerian degeneration. Crushed sciatic nerves of 8‐week‐old C57/BL6J male mice underwent complete Wallerian degeneration at 1 week. Two weeks after crush, there was a prominent increase in the number of Na+ channel clusters per unit area, and binary or broad Na+ channel clusters were frequently found. Excess Na+ channel clusters were retained up to 20 weeks post‐injury. Excitability testing using latent addition suggested that nodal persistent Na+ currents markedly increased beginning at week 3, and remained through week 10. These results suggest that axonal regeneration is associated with persistently increased axonal excitability resulting from increases in the number and conductance of Na+ channels. Muscle Nerve, 2008
A new method for measuring compound muscle action potentials in facial palsy: A preliminary study
Authors: Haginomori Shin‐Ichi , Wada Shin‐Ichi , Takamaki Atsuko , Nonaka Ryuzaburo , Takenaka Hiroshi , Takubo Takayuki
Published: May 2008

To establish a simple, reproducible procedure for studying facial motor nerve conduction (MNC), we determined the optimal electrode position to record evoked compound muscle action potentials (CMAPs) from perioral muscles in normal subjects. We examined three new electrode positions in which the electrode connected to the one input of the amplifier was placed on the mental protuberance, and the one connected to the other input was placed on the skin over the orbicularis oris muscle (the philtrum, mouth angle, or lower lip). We then compared the morphology and amplitudes of the CMAPs, right–left differences, and the reproducibility of CMAP amplitudes with recordings taken from the standard electrode position in which one electrode was placed on the nasolabial fold closely lateral to the ala nasi, and the other was placed on the skin over the orbicularis oris. Percutaneous supramaximal electrical stimulation was applied to the main trunk of the facial nerve. All three of the new recording positions showed greater amplitudes and more obvious biphasic CMAPs than the standard method. Positioning the electrode connected to the negative input on the philtrum was optimal in terms of right–left differences and the reproducibility of CMAP amplitudes. Therefore, this midline recording is a simple, reproducible method for calculating the CMAP amplitude ratio. However, prior to clinical use of this procedure, analyses of patients with facial palsy are required. Muscle Nerve 37: 764–769, 2008
Childhood multifocal acquired demyelinating sensory and motor neuropathy
Authors: Wakamoto Hiroyuki , Chisaka Aya , Inoue Naozou , Nakano Naoko
Published: May 2008

We report the first pediatric cases of multifocal acquired demyelinating sensory and motor neuropathy with electrophysiologic evidence of proximal conduction abnormalities but no definite conduction block. Intravenous immunoglobulin caused clinical improvement followed by long‐term remission without maintenance therapy; one patient has exhibited a monophasic course and the other has had a single relapse during the last 5 years. These cases suggest that there may be a long‐term sustained beneficial effect of intravenous immunoglobulin therapy for children with this neuropathy. Muscle Nerve, 2008
Reference jitter values for concentric needle electrodes in voluntarily activated extensor digitorum communis and orbicularis oculi muscles
Authors: Kouyoumdjian João Aris , Stålberg Erik V.
Published: May 2008

The aim of this study was to estimate normal jitter in voluntarily activated extensor digitorum communis (EDC) and orbicularis oculi (OOc) muscles using a disposable concentric needle electrode (CNE). The EDC of 67 normal subjects (22 males and 45 females, mean age 35.5 ± 10.2 years) and the OOc of 50 normal subjects (13 males and 37 females, mean age 37.9 ± 9.6 years) were studied. Jitter values were expressed as the mean consecutive difference (MCD) of 20 potential pairs. The mean MCD for EDC was 23.6 ± 3.1 μs (upper 95% confidence limit [CL]: 29.7 μs). The mean MCD of all potential pairs (n = 1340) was 23.5 ± 7.3 μs (95% CL: 38.2 μs). The mean MCD for the 18th highest value was 31.4 ± 4.9 μs (95% CL: 41.2 μs). The mean MCD for OOc was 24.7 ± 3.1 μs (95% CL: 31.0 μs). The mean MCD of all potential pairs (n = 1000) was 24.7 ± 7.1 μs (95% CL: 39.0 μs). The mean MCD for the 18th highest value was 32.7 ± 4.1 μs (95% CL: 40.9 μs). Our reported CNE jitter values obtained during voluntary activation represent the largest series currently available. The suggested practical limit in the EDC for mean MCD was 30 μs and for outliers was 42 μs, and in the OOc for mean MCD was 31 μs and 41 μs for outliers. The present study confirms that CNE can be used to assess jitter values, although certain precautions must be taken. Muscle Nerve 37: 694–699, 2008
Morphology of poly(ε‐caprolactone)‐b‐poly(ethylene glycol)‐b‐poly(ε‐caprolactone) assemblies in diluted aqueous solution and gel studied by atomic force microscopy
Authors: Guo Shengrong , Zhang Yaqiong , Yu Zhang
Published: May 2008

Morphologies of poly(ε‐caprolactone)‐b‐poly(ethylene glycol)‐b‐poly(ε‐caprolactone) (PCL‐PEG‐PCL) triblock copolymer self‐assemblies in the diluted solution and in gel were studied by atomic force microscopy (AFM). The copolymer self‐assembled into wormlike aggregates, of uniform diameter, in water. The wormlike aggregates arranged in order to form separate clusters in the diluted copolymer solution; at a higher copolymer concentration, the clusters became bigger and bigger, and packed together to form gel. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and characterization of κ‐carrageenan/poly(N,N‐diethylacrylamide) semi‐interpenetrating polymer network hydrogels with rapid response to temperature
Authors: Chen Jun , Liu Mingzhu , Jin Shuping , Liu Hongliang
Published: May 2008

In this study, a novel classical thermo‐ and salt‐sensitive semi‐interpenetrating polymer network (semi‐IPN) hydrogel composed of poly(N,N‐diethylacrylamide) (PDEAm) and κ‐carrageenan (KC) was synthesized by free radical polymerization. The structure of the hydrogels was studied by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). FTIR and SEM revealed that the semi‐IPN hydrogels possessed the structure of H‐bonds and larger number of pores in the network. Compared to the PDEAm hydrogel, the prepared semi‐IPN hydrogels exhibited a much faster response rate to temperature changes and had larger equilibrium swelling ratios at temperatures below the lower critical solution temperature (LCST). The salt‐sensitive behavior of the semi‐IPN hydrogels was dependent on the content of KC. In addition, during the reswelling process, semi‐IPN hydrogels showed a non‐sigmoidal swelling pattern. Copyright © 2008 John Wiley & Sons, Ltd.
Prognostic factors for patients with Ewing sarcoma (EWS) at first recurrence following multi‐modality therapy: A report from the Children's Oncology Group
Authors: Leavey Patrick J. , Mascarenhas Leo , Marina Neyssa , Chen Zhengjia , Krailo Mark , Miser James , Brown Ken , Tarbell Nancy , Bernstein Mark L. , Granowetter Linda , Gebhardt Mark , Grier Holcombe E.
Published: May 2008

Background

The prognosis for patients with recurrent Ewing sarcoma (EWS) is very poor with 5‐year survival of 13%.

Methods

To evaluate prognostic factors for these patients we studied patients initially treated on the multi‐institutional study INT0091.

Results

Two hundred sixty‐two patients experienced disease recurrence. The median time to first recurrence was 1.3 years (0–7.4 years), 1.4 years (0–7.4 years) for patients with initially localized disease and 1 year (0–6 years) for patients with initially metastatic disease. Time to first recurrence from date of initial diagnosis was a predictor of post‐recurrence survival (P < 0.0001). Twenty‐one percent of patients, with recurrent or progressive disease ≥2 years from initial diagnosis, had an estimated 5‐year survival of 30% (vs. 7% estimated 5‐year survival with an earlier recurrence). No statistical difference was detected between patients whose disease recurred <1 year and between 1 and 2 years from initial diagnosis. A stepwise relative risk model and backwards stepwise regression was used to explore factors significantly associated with risk for post‐recurrence death. Significant risk factors for death after recurrence included recurrence at combined local and distant sites, elevated LDH at initial diagnosis and initial recurrence less than 2 years after diagnosis. Isolated pulmonary recurrence was not predictive of survival after recurrence.

Conclusion

Patients with a longer disease control interval represent the subset of patients most likely to survive following recurrence of EWS. All patients with recurrence would benefit from collaborative trials to investigate new therapeutic options. Pediatr Blood Cancer 2008;51:334–338. © 2008 Wiley‐Liss, Inc.
Numb chin syndrome as initial manifestation in a child with acute lymphoblastic leukemia
Authors: Kraigher‐Krainer Elisabeth , Lackner Herwig , Sovinz Petra , Schwinger Wolfgang , Benesch Martin , Urban Christian
Published: May 2008

Numb chin syndrome (NCS) describes the affection of the inferior alveolar nerve and is a purely sensory neuropathy. Its symptoms include numbness of the skin of the chin, the lip and the gingival mucosa. Mostly seen in adults, it has rarely been described in children. We report on an 11‐year‐old male who presented with NCS as initial manifestation of acute lymphoblastic leukemia of B‐cell type. Pediatr Blood Cancer 2008;51:426–428. © 2008 Wiley‐Liss, Inc.
Conservative management of priapism secondary to leukemia
Authors: Castagnetti Marco , Sainati Laura , Giona Fiorina , Varotto Stefania , Carli Modesto , Rigamonti Waifro
Published: May 2008

We report four cases of leukemia (three chronic myeloid and one T‐cell acute lymphoblastic) presenting with priapism in children 9‐ to 13‐year old. All of them presented with hyperleukocytosis, and three had anemia plus thrombocytosis. All patients underwent chemotherapy and two had leukopheresis. In all cases, priapism was managed conservatively. Erection required up to 13 days to start improving but none of the patients developed clinical evidence of long‐term erectile dysfunction. Based on these cases, conservative management of priapism in children with leukemia might be adequate and not lead to long‐term erectile dysfunction. Pediatr Blood Cancer 2008;51:420–423. © 2008 Wiley‐Liss, Inc.
Host factors and consequence of chemotherapy in pediatric cancer patients
Authors: Johnson L'Aurelle A. , Ross Julie A.
Published: May 2008

The 5‐year survival rates for childhood ALL are approaching 80%, but therapy‐related toxicities are common. One of the challenges in this population is determining the most efficacious therapeutic regimens for these individuals. Factors such as drug metabolism, genetics, and concomitant disease affect drug efficacy and may be important in determining therapeutic outcomes in these patients. This review will focus on these factors in the treatment of childhood ALL. Pediatr Blood Cancer 2008;51:320–326. © 2008 Wiley‐Liss, Inc.
Extra‐renal non‐cerebral rhabdoid tumours
Authors: Bourdeaut Franck , Fréneaux Paul , Thuille Bénédicte , Bergeron Christophe , Laurence Valérie , Brugières Laurence , Vérité Cécile , Michon Jean , Delattre Olivier , Orbach Daniel
Published: May 2008

Background

Rhabdoid tumours (RTs) are aggressive malignancies of childhood, mainly occurring in the kidney and brain. We describe a national multi‐centre retrospective analysis of extra‐renal non‐cranial RTs (ERRTs).

Procedure

Diagnosis relied on central histological review and/or on hSNF5/INI1 defect, evidenced by immunohistochemistry or molecular screening. Clinical data were obtained from physicians.

Results

Twenty six patients fulfilled the inclusion criteria. Median age at diagnosis was 28 months [0–366], including late childhood and young adults cases. Surgery, either initial or secondary, was complete in three. All but three patients received chemotherapy, with variable regimens. Additional radiotherapy was used in six patients. Median time to recurrence or progression was 5 months [0–44], and one patient remained free of disease at 7 years.

Conclusions

ERRTs share the same chemosensitivity, early recurrence, and poor prognosis as renal and cerebral RTs. No chemotherapy regimen demonstrates a superior response. Pediatr Blood Cancer 2008;51:363–368. © 2008 Wiley‐Liss, Inc.
Successful topical treatment with mitomycin‐C in a female with post‐brachytherapy vaginal stricture
Authors: Betalli Pietro , De Corti Federica , Minucci Daria , Mazzarotto Renzo , Meneghini Luisa , Bisogno Gianni , Cecchetto Giovanni
Published: May 2008

Vaginal strictures are rare entities in pediatric population, mainly due to congenital genito‐urinary tract malformations and sequelae of their surgical treatment, recurrent vaginitis and multisciplinary therapy for malignant tumors. The therapy of choice is not standardized. Conservative treatments are favored and dilators seem to be very effective, but their use in children is difficult due to poor compliance. We report our experience with topical application of mitomycin‐C in a female with vaginal stricture secondary to brachytherapy. Pediatr Blood Cancer 2008;51:550–552. © 2008 Wiley‐Liss, Inc.
Cocontinuous cellulose acetate/polyurethane composite nanofiber fabricated through electrospinning
Authors: Tang Chunyi , Chen Pingping , Liu Haiqing
Published: May 2008

Cocontinuous cellulose acetate (CA)/polyurethane (PU) composite nanofibers were obtained through electrospinning of partially miscible CA and PU in 2:1 N,N‐dimethylacetamide (DMAc)/acetone mixture solvent. Their structures, mechanical, and thermal properties were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and differential scanning calorimetry (DSC). The structures and morphologies of the nanofibers were affected by component ratio in the binary mixtures. PU component not only facilitated the electrospinning of CA at CA concentration down to 12 wt%, but reinforced the tensile strength of CA/PU nanofibrous mats, while semirigid component CA in the composite nanofibers could greatly improve the rigidity and dimensional stability of CA/PU nanofibrous mats. In a series of nanofibrous mats with varied CA/PU composition ratios, CA/PU 20/80 showed excellent tensile strength and Young's modulus. The residual product after selective removal of any one of the components in CA/PU composite nanofibers by washing with proper solvent maintained the fiber structure but greatly reduced the fiber size, suggesting CA/PU composite fibers showed a cocontinuous nanofiber structure due to phase separation in the spinning solution and in the course of electrospinning. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Cell coalescence suppressed by crosslinking structure in polypropylene microcellular foaming
Authors: Zhai Wentao , Wang Hongying , Yu Jian , Dong Jinyong , He Jiasong
Published: May 2008

A series of crosslinked polypropylene samples with increased melt strengths were prepared via a copolymerization reaction, followed by melt processing. These crosslinked PP samples (PP‐Cs) were foamed by a temperature rising process using supercritical CO2 as the physical blowing agent. The introduction of crosslinking structure resulted in PP‐Cs foams with well‐defined closed cell structure, decreased cell size, and increased cell density in comparison with a linear PP, which were attributed to the suppressed cell coalescence due to the significant increase in melt strength of PP‐Cs. Further increasing the crosslinking degree tended to enhance the suppression effect on the cell coalescence, and hence increase the cell density of PP foams under the same foaming conditions, especially at the longer foaming times. The well‐defined closed cell structure was observed at the foaming temperature of 170–250°C and saturation pressure of 12–20 MPa. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
A novel biobased resin‐epoxidized soybean oil modified cyanate ester
Authors: Zhan Guozhu , Zhao Lin , Hu Sheng , Gan Wenjun , Yu Yingfeng , Tang Xiaolin
Published: May 2008

Cyanate ester (CE) resin was modified with renewable resource, i.e. epoxidized soybean oil (ESO), and the effects of ESO content on the curing co‐reaction, morphologies, water absorption behaviors, thermal and mechanical properties of CE/ESO blends were studied. Differential scanning calorimeter (DSC), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and dynamic mechanical analysis (DMA) were employed to characterize the ESO‐modified CE polymer networks. Homogeneous structures were observed for low‐content of ESO modified CE systems by SEM, while ESO‐rich particles were observed in the modified systems with ESO above 15 wt %. The blend of the CE and ESO resulted in an excellent combination as a new biobased thermoset material having relatively high mechanical properties with 15 and 20 wt % ESO as replacement of CE. Enhanced elongations at break were observed for the modified systems while the tensile strengths kept about the same level at the same time. The storage moduli and glass transition temperatures of the modified systems in the glassy state and rubber plateau were observed to be lower than those of neat CE with the increase of ESO weight percent. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Design of experiments applied to the study of the reaction between phenylphosphonic dichloride with bisphenol by inverse phase transfer catalysis method
Authors: Iliescu Smaranda , Grozav Ion , Plesu Nicoleta , Pascariu Aurelia , Ilia Gheorghe
Published: May 2008

The reaction of phenylphosphonic dichloride with bisphenol A (BA) by inverse phase transfer catalysis method was investigated. The design of experiments method was applied to establish the correlation between the simultaneous influence of the parameters (alkaline medium, reaction temperature, reagents molar ratio, and stirring speed) on yield and inherent viscosity, as well as for identifying the best reaction conditions. This method allows the simultaneous variation of control factors, thus decreasing the number of experiments in the polyphosphate synthesis. The process control factors used in this study were reagents' molar ratio, base concentration, and reaction temperature. The experimental results using 20 and 14 process runs, lead to an optimal synthesis procedure. The optimal values for yield and viscosity were obtained at molar ratio = 1, base concentration = 1.1 M, and reaction temperature = −12°C and have been experimentally verified with a series of four runs. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers