bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Trace Tin by Anodic Stripping Voltammetry at a Carbon Paste Electrode
Authors: Li Yi‐Heng , Xie Hong‐Qi , Zhou Fang‐Qin , Guo Hui‐Shi
Published: April 2006

A sensitive and selective procedure for the determination of trace tin at a carbon paste electrode was described. Each measurement cycle consisted of three steps: accumulation, reduction and stripping. The tin complex with bromopyrogallol red (BPR) was accumulated on the electrode surface in 0.10 mol/L acetate buffer (pH 4.5). After electrochemical reduction of Sn(II) had been carried out, the reoxidation wave of Sn(0) appeared at −0.69 V (vs. SCE) on scanning the potential in the positive direction in 4.0 mol/L HCl. For a preconcentration time of 2 min, the detection limit was 0.06 μg/L (5×10−10 mol/L ) and the linear range was from 0.1 to 50 μg/L. The proposed method was applied to the determination of tin in canned food and waste water samples with satisfactory results.
Carbon Powder Based Films on Traditional Solid Electrodes as an Alternative to Disposable Electrodes
Authors: Yosypchuk Bogdan , Barek Jiří , Fojta Miroslav
Published: April 2006

The covering of conventional solid electrode with a film using an ink containing a conductive powder and a polymer enables to broaden the potential window of the original solid electrode. A solid silver amalgam electrode covered with such a film exhibits a potential window from −600 mV to +1400 mV vs. SCE reference electrode. The renewal of the film is fast and simple: the electrode can be simply wiped with a filter paper to remove the old film and immersed into an ink solution or 1–2 μL of this ink solution can be applied to the surface of the electrode with a micro dispenser to form a new film. Therefore, just the inexpensive film at the electrode surface is disposable and there is no need to dispose the whole, more expensive electrode. Moreover, when a suitable electrochemical pretreatment of the film electrode is applied, the same film can be used for reproducible measurements for several days.
Electrochemical Detection of ClO$\rm{ {_{3}^{-}}}$, BrO$\rm{ {_{3}^{-}}}$, and IO$\rm{ {_{3}^{-}}}$ at a Phosphomolybdic Acid Linked 3‐Aminopropyl‐Trimethoxysilane Modified Electrode
Authors: Rahman Md. Aminur , Won Mi‐Sook , Wei Pei‐Hai , Shim Yoon‐Bo
Published: April 2006

A composite film modified electrode containing a Keggin‐type heteropolyanion, H3(PMo12O40)⋅H2O, was fabricated with 3‐aminopropyltrimethoxysilane (APMS) attached on an electrochemically activated glassy carbon (GC) electrode through the formation of COSi bond. PMo12O$\rm{ {_{40}^{3-}}}$ was then complexed with APMS through the electrostatic interaction between the phosphate groups of PMo12O$\rm{ {_{40}^{3-}}}$ and amine groups of APMS (PMo12O$\rm{ {_{40}^{3-}}}$‐APMS). XPS and cyclic voltammetry were employed for characterization of the composite film. The PMo12O$\rm{ {_{40}^{3-}}}$‐APMS modified electrode showed three reversible redox pairs with smaller peak‐separation and was stable in the larger pH range compared with that in a solution phase. The catalytic properties of the modified electrode for the reduction of ClO$\rm{ {_{3}^{-}}}$, BrO$\rm{ {_{3}^{-}}}$, and IO$\rm{ {_{3}^{-}}}$ were studied and the modified electrode exhibited good electrocatalytic activities for the three anions. The experimental parameters, such as pH, temperature, and the applied potential were optimized. The detection limits were determined to be 7.0±0.35 μM, 4.0±0.17 μM, and 0.1±0.04 μM for ClO$\rm{ {_{3}^{-}}}$, BrO$\rm{ {_{3}^{-}}}$, and IO$\rm{ {_{3}^{-}}}$ , respectively. The modified electrode was applied to natural water samples for the detection of ClO$\rm{ {_{3}^{-}}}$, BrO$\rm{ {_{3}^{-}}}$, and IO$\rm{ {_{3}^{-}}}$.
Microwave Activation of Processes in Mesopores: The Thiourea Electrooxidation at Mesoporous Platinum
Authors: Ghanem Mohamed A. , Coles Barry A. , Compton Richard G. , Marken Frank
Published: April 2006

In situ microwave activation is applied to the electrochemical oxidation of thiourea at low surface area (polished polycrystalline) and at high surface area (electrodeposited mesoporous platinum coated) platinum microelectrodes. The one electron oxidation of thiourea to formamidine disulfide is monitored as a function of the different activation parameters. In the absence of microwaves (ambient temperature, low mass transport) increasing the surface area (roughness) increases the thiourea oxidation response predominantly due to adsorption effects. In the presence of high microwave intensities, high mass transport and thermal effects further increase the oxidation current at mesoporous platinum. The most effective thickness of the mesoporous platinum film for the thiourea oxidation process is estimated as 3 μm independent of electrode diameter, temperature, or mass transport effects.
Universal interpolating function for the dispersion coefficient of DNA fragments in sieving matrices
Authors: Mercier Jean‐François , Slater Gary W.
Published: April 2006

The separation of DNA fragments by (slab or capillary) gel electrophoresis has been studied extensively. To characterize the separation achieved by such systems, one needs to understand the impact (and their dependency upon the experimental quantities) of two physical parameters: the electrophoretic mobility μ and the diffusion coefficient D. Three different regimes have been shown to exist for both μ and D: the Ogston regime, the reptation regime and the reptation with orientation regime (note that separation is only possible for the first two regimes). In the small electric field limit, both μ and D are apparently well described by theories for all three regimes. Unfortunately this results in disjointed scaling laws and no theory‐based general equations can apply to all regimes. Recently, an empirical interpolating formula has been proposed that adequately fits the low electric field mobility μ of dsDNA fragments across all three regimes and is compatible with accepted theories. In this article we review and clarify the current state of knowledge regarding the size dependence of the mobility and the diffusion coefficient and propose an interpolating formula for molecular size dependence of the low field diffusion coefficient D. With formulas for both the mobility and the diffusion coefficient as a function of the experimental conditions one could, in principle, optimize any gel/polymer matrix‐based electrophoresis system for a wide range of DNA molecular sizes.
Improved 2‐DE of microorganisms after acidic extraction
Authors: Herbert Ben R. , Grinyer Jasmine , McCarthy John T. , Isaacs Mitchell , Harry Elizabeth J. , Nevalainen Helena , Traini Mathew D. , Hunt Sybille , Schulz Ben , Laver Matthew , Goodall Anthony R. , Packer Joanne , Harry Jenny L. , Williams Keith L.
Published: April 2006

2‐DE separations of protein extracts sometimes have problems with poor resolution and streaking. This problem is particularly apparent with microorganisms, most notably those with a large cell wall. Here we describe a novel, rapid protocol for the extraction of microorganisms in acidic conditions, leading to increased resolution and 2‐D gel quality. The efficiency of the protocol is demonstrated with extracts of bacteria, Escherichia coli and Bacillus subtilis; fungus, Trichoderma harzianum and yeast, Saccharomyces cerevisiae. We also demonstrate using a membrane centrifugal filtration, that large acidic molecules in excess of 100 kDa, probably including cell wall material, are responsible for the separation difficulties. A range of acidic extraction conditions were investigated, and it was found that optimal extraction is achieved using an extraction solution acidified to pH 3 by 80 mM citric acid. These findings have significant implications for the proteomic study of many medically, agriculturally and environmentally significant microorganisms, as the cell walls of these organisms are often considerably more complex than many commonly studied laboratory strains.
The human heart proteome: Two‐dimensional maps using narrow‐range immobilised pH gradients
Authors: Westbrook Jules A. , Wheeler Jun X. , Wait Robin , Welson Sandy Y. , Dunn Michael J.
Published: April 2006

The analysis of complex proteomes is undertaken using a variety of techniques and technologies such as 2‐DE, surface‐enhanced laser desorption ionisation, and various types of MS. In order to overcome the complexities of protein expression in discrete proteomes, sample fractionation has become an important aspect of proteomic experiments. The use of narrow‐range IPGs (nrIPGs) is of special importance using the 2‐DE proteomics workflow, since an enhanced visualisation of a given proteome is achieved through an improved physical separation and resolution of proteins. The work described in this paper presents a series of protein maps of the human heart left ventricle proteome that have been generated using nrIPGs for the first, IEF, dimension of 2‐DE. A total of 374 gel spots were excised from seven different pH gradients, covering the range pH 3–10, giving rise to a total of 388 identifications from 110 unique proteins. Using Gene Ontologies (GOs), the identified proteins were found to be associated with 97 types of GO Process, 144 types of GO Function, and 54 types of GO Component. It is hoped that the maps presented in this paper will be of use to other researchers for reference purposes.
Role of chemical structure in stereoselective recognition of beta‐blockers and H1‐antihistamines by human serum transferrin in capillary zone electrophoresis
Authors: Gagyi László , Gyéresi Árpád , Kilár Ferenc
Published: April 2006

Studies on chiral resolution of beta‐blocker and H1‐antihistamine drugs by CZE using human serum transferrin are described. The drugs with different structures passed a pseudostationary protein zone in a coated capillary applying the partial filling method for the chiral separation. In this study we screened 15 compounds; most of them showed longer migration time, indicating an interaction with transferrin. Stereoselective interaction was observed only for five beta‐blockers (celiprolol, talinolol, mepindolol, bopindolol, and oxprenolol) and for one H1‐antihistamine (brompheniramine). The most important finding was that very small differences in the chemical structure of the drug resulted in significant changes in the stereoselective recognition. Resolution of mepindolol enantiomers was observed showing the essential role of one methyl group compared to pindolol, which is not resolved by transferrin. Bopindolol, also a derivative of pindolol having bigger difference in the structure, showed more experienced separation. The very slight difference between alprenolol and oxprenolol was also revealed with these methods, since only oxprenolol enantiomers, having an extra oxygen in the structure, are resolved. Determining the migration order of the eutomers and distomers (chlorpheniramine, brompheniramine) we can deduct conclusions about the role of serum proteins in the delivery of drugs within the body.
Estimating the long memory granger causality effect with a spectrum estimator
Authors: Chen Wen‐Den
Published: April 2006

This paper discusses the Granger causality test by a spectrum estimator which allows the transfer function to have long memory properties. In traditional methodology the relationship among variables is usually assumed to be short memory or contemporaneous. Hence, we have to make sure they are of the same integrated order, else there might be a spurious regression problem. In practice, not all the variables are fractionally co‐integrated in the economic model. They may have the same random resources, but under a different integrated order. This paper focuses on how to capture the long memory Granger causality effect in the transfer function. This does not necessarily assume the variables are of the same fractional integrated order. Moreover, by the transfer function we construct an estimator to test the long memory effect with the Granger causality sense. Copyright © 2006 John Wiley & Sons, Ltd.
[1‐Me‐1‐closo‐SnB11H11]− as a potential weakly coordinating anion: Synthesis of Rh(PPh3)2(1‐Me‐closo‐SnB11H11) and comparisons with Rh(PR3)2 (1‐H‐closo‐CB11 H11)
Authors: Molinos Eduardo , Player Thomas P. H. , Kociok‐Köhn Gabriele , Ruggerio Giuseppe D. , Weller Andrew S.
Published: April 2006

The closo‐stannaborane salt [Rh(PPh3)2‐(nbd)][1‐Me‐1‐closo‐SnB11H11] reacts with H2 in CH2 Cl2 solution to afford the contact ion‐pair Rh(PPh3)2(1‐Me‐closo‐SnB11H11), which has been characterized in solution and the solid state by X‐ray diffraction. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:174–180, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20218
Metallacyclopentadienes and related heterocycles via 1,1‐organoboration of alkyn‐1‐ylmetal compounds
Authors: Wrackmeyer Bernd
Published: April 2006

Metallacyclopentadienes (metalloles) containing M = Si, Ge, Sn, Pb, Ti, Pt can be prepared by 1,1‐organoboration of alkyn‐1‐ylmetal compounds LnMCCR1(R1 = H, alkyl, aryl, silyl, etc; L depends on M, and can be hydrogen, alkyl, aryl, Cl, Br, amino groups, a chelating diphosphane, and one or more L can be again alkynyl groups). These reactions proceed via activation of the MC bond(s) by an electron‐deficient triorganoborane BR3 (R = alkyl, aryl; non‐cyclic, monocyclic, bicyclic, and tricyclic boranes), at first intermolecular and then intramolecular. In the course of these reactions, the MC bonds are cleaved, zwitterionic alkynylborate‐like intermediates are formed, in which the metal‐containing fragments are coordinated side‐on to the CC bonds. In most cases, the 1,1‐organoboration reactions tolerate various functional groups at the alkyne as well as at the metal. The characterization of intermediates and final products by X‐ray structural analysis and by multinuclear magnetic resonance spectroscopy (NMR) is documented and described. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:188–208, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20222
Synthesis and structure of the coordinatively unsaturated boron subphthalocyanine cation, [B(SubPc)]+
Authors: Kato Tsuyoshi , Tham Fook S. , Boyd Peter D. W. , Reed Christopher A.
Published: April 2006

The boron subphthalocyanine cation, B(SubPc)+, has been prepared as a salt of a weakly coordinating carborane anion, CHB11Me5Br6−, by a metathesis reaction of Et3Si(CHB11Me5Br6) with B(SubPc)Cl. The separation of the cation and anion in the X‐ray structure indicates coordinative unsaturation at the boron center, and this is corroborated by DFT calculations. A strongly Lewis acidic nature for the B(SubPc)+ cation is indicated by its hydrolysis to an unusual product, the di‐meso‐N‐protonated μ‐oxo dimer, [H(SubPc)B‐O‐B(SubPc)H]2+. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:209–216, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20223
Reactivity of terminal transition metal borylene complexes
Authors: Braunschweig Holger , Rais Daniela
Published: April 2006

The chemistry of terminal transition metal borylene complexes is reviewed, with particular attention to recent developments concerning the reactivity of these species. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:238–238, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20247
Theoretical analysis on thermoelectric power generation with rectangular‐fin elements and its applicability in micro systems
Authors: Oda Yutaka , Yoshida Hideo
Published: April 2006

A thermoelectric module, which consists of rectangular‐fin elements and has a simple structure suitable for micro fabrication, was newly proposed for a micro‐ to milli‐scale thermoelectric power generator. A unit model was introduced to examine the basic characteristics of thermoelectric power generation with rectangular‐fin elements. Theoretical descriptions of the power density and conversion efficiency were given by solving one‐dimensional heat and current flows inside the elements. Then, it was found that there exist optimum aspect ratios of the elements to achieve maximum power density and conversion efficiency. Power density becomes larger if the module is downsized with a similarity in shape, while conversion efficiency remains constant, i.e., smaller devices show better performance. Finally, comparative analysis with a standard pi‐type module was conducted to emphasize the superiority of the proposed module in micro systems, when convective heat transfer resistance is taken into account. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(3): 224–244, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20108
The heat transfer and pressure drop characteristics of finned tube banks in forced convection (effects of fin height on pressure drop characteristics)
Authors: Kawaguchi Kiyoshi , Okui Kenichi , Asai Toshihiro , Hasegawa Yutaka
Published: April 2006

In recent years the requirement for the reduction of energy consumption has been increasing to solve the problems of global warming and the shortage of petroleum resources. For example, in the power generation field, as thermal power generation occupied 60% of the power generation demand, considerable improvement of the thermal efficiency is required. This paper describes the pressure drop characteristics of finned tube banks used for heat exchangers in thermal power generation that were clarified by testing serrated finned tube banks with different fin heights for improved heat transfer and conventional spiral finned tube banks with different fin heights, and an equation to predict pressure drop which is necessary for the heat exchanger design is proposed. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(3): 179–193, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20112
Cannabinoid agonist WIN55,212‐2 induces apoptosis in cerebellar granule cells via activation of the CB1 receptor and downregulation of bcl‐xL gene expression
Authors: Pozzoli Giacomo , Tringali Giuseppe , Vairano Mauro , D'Amico Monia , Navarra Pierluigi , Martire Maria
Published: April 2006

The endogenous cannabinoid system is involved in the regulation of a number of physiologic effects in both the central and peripheral nervous systems. Its role in the control of neuronal cell proliferation has attracted major attention because of its potential implications for new therapeutic strategies. In the present study, we demonstrated that treatment of cultured cerebellar granule cells with the synthetic cannabinoid WIN55,212‐2, causes cell‐body and nuclear shrinkage, which are hallmarks of neuronal apoptosis, as well as concentration‐dependent decrease in cell viability. Staining with the fluorescent nuclear dye, Hoechst 33258, revealed apoptosis in 27.1% and 58.5% of cells exposed to 1 and 10 μM of WIN55,212‐2, respectively (P < 0.01 and P < 0.001 vs. control respectively) after 36 hr. After 24 hr of exposure to WIN55,212‐2, mRNA levels for the anti‐apoptotic gene bcl‐xL were reduced to 45.6% of those found in control (P < 0.01). These effects were completely reverted when cells were exposed to the synthetic cannabinoid in the presence of the specific CB1‐receptor antagonist, SR141716A (1 μM). Moreover, the pro‐apoptotic effect of 10 μM WIN55,212‐2 could be reduced by the addition to the incubation medium of a cell‐permeant inhibitor of caspase‐1 (50 nM). Finally, WIN55,212‐2 significantly increased caspase‐1 activity after 24 hr. These findings show that the activation of CB1 receptors on cerebellar granule cells induces apoptotic cell death, which is associated with downregulation of the anti‐apoptotic gene, bcl‐xL, and at least in part, activation of caspase‐1. © 2006 Wiley‐Liss, Inc.
Kinetics of endothelin‐induced inhibition and glucose permeability of astrocyte gap junctions
Authors: Blomstrand F. , Giaume C.
Published: April 2006

Gap junctions contribute to important functions of communicating glial cells in brain physiology and pathology. Endothelins (ETs), a vasoactive family of peptides present in the brain, have been described as potent inhibitors of astrocyte gap junctional communication. Through dye‐coupling studies we demonstrate here that this inhibition occurs rapidly and then successively reverses and returns to control levels after 90 min of continuous ET1 or ET3 exposure. In addition, long‐term exposure of cells to ET3, which acts mainly on ETB receptors, also desensitized the acute action of ET1, which was previously shown to act through either ETA or ETB receptor sites, or both. The gap junction blocker carbenoxolone did not show any time‐dependent desensitization and was fully effective also in cultures treated with ETs for prolonged times. The ETs inhibitory effects were partially prevented when blocking pertussis toxin‐sensitive G‐proteins, chelating intracellular Ca2+, or omitting extracellular Ca2+. We further show that ETs modulate gap junction‐mediated transfer of 2‐[N‐(7‐nitrobenz‐2‐oxa‐1,3‐diazol‐4‐Y1)amino]‐2‐deoxyglucose (2‐NBDG), a fluorescent glucose molecule, indicating a role of astrocyte gap junction coupling in metabolic trafficking and suggesting the importance of these peptides in the control of intercellular diffusion of energetic compounds. These findings might have particular relevance in early tissue reactions after various cerebral injuries, which commonly involve increased cerebral ET levels. © 2006 Wiley‐Liss, Inc.
Accumulation of LPS by polyethylene particles decreases bone attachment to implants
Authors: Xing Zhiqing , Pabst Michael J. , Hasty Karen A. , Smith Richard A.
Published: April 2006

Molecules absorbed on the surface of particulate wear debris may contribute to inflammatory reactions that lead to aseptic loosening of implants. Lipopolysaccharide (LPS), a bacterial endotoxin, can attach to many biomaterials and stimulate macrophages to secrete osteoclast‐activating cytokines. We tested the adsorption of LPS by polyethylene particles in vitro and examined the biological effects of LPS absorption on bone remodeling around implants in vivo. Polyethylene particles were incubated in radiolabeled LPS solutions, and adsorption of LPS by the particles was quantified by radioassay. Because polyethylene particles are hydrophobic and less dense than water, they floated and clumped when incubated in a water solution of LPS, resulting in low adsorption of LPS. However, when particles were incubated in an ethanol solution of LPS, most of the LPS was adsorbed by the particles, and was resistant to washing with water. Triton X‐100 (10%), however, effectively washed the LPS off the particles. In a rat model, the presence of polyethylene particles around the implant in the femoral canal decreased bone attachment to the implant at 6 weeks. Incubating the particles with LPS before implantation, or intermittent administration of LPS systemically, further decreased bone–implant attachment to similar extents, but had no effect on the bone density of the control side femurs. Our data indicate that polyethylene particles have high affinity for LPS, depending on many factors, especially the solvents of the LPS. Intermittent systemic administration of LPS affects bone remodeling but only occurs in the area containing polyethylene particles and titanium implants, supporting the hypothesis that the presence of polyethylene particles around implants can result in accumulation of LPS from exogenous sources. This may cause local levels of LPS that are high enough to affect bone remodeling around implants. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Effective therapy of transected quadriceps muscle in rat: Gastric pentadecapeptide BPC 157
Authors: Staresinic Mario , Petrovic Igor , Novinscak Tomislav , Jukic Ivana , Pevec Damira , Suknaic Slaven , Kokic Neven , Batelja Lovorka , Brcic Luka , Boban‐Blagaic Alenka , Zoric Zdenka , Ivanovic Domagoj , Ajduk Marko , Sebecic Bozidar , Patrlj Leonardo , Sosa Tomislav , Buljat Gojko , Anic Tomislav , Seiwerth Sven , Sikiric Predrag
Published: April 2006

We report complete transection of major muscle and the systemic peptide treatment that induces healing of quadriceps muscle promptly and then maintains the healing with functional restoration. Initially, stable gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, M.W. 1419, PL‐10, PLD‐116, PL 14736 Pliva, Croatia; in trials for inflammatory bowel disease; wound treatment; no toxicity reported; effective alone without carrier) also superiorly accelerates the healing of transected Achilles tendon. Regularly, quadriceps muscle completely transected transversely 1.0 cm proximal to patella presents a definitive defect that cannot be compensated in rat. BPC 157 (10 µg, 10 ng, 10 pg/kg) is given intraperitoneally, once daily; the first application 30 min posttransection, the final 24 h before sacrifice. It consistently improves muscle healing throughout the whole 72‐day period. Improved are: (i) biomechanic (load of failure increased); (ii) function (walking recovery and extensor postural thrust/motor function index returned toward normal healthy values); (iii) microscopy/immunochemistry [i.e., mostly muscle fibers connect muscle segments; absent gap; significant desmin positivity for ongoing regeneration of muscle; larger myofibril diameters on both sides, distal and proximal (normal healthy rat‐values reached)]; (iv) macroscopic presentation (stumps connected; subsequently, atrophy markedly attenuated; finally, presentation close to normal noninjured muscle, no postsurgery leg contracture). Thus, posttransection healing—consistently improved—may suggest this peptide therapeutic application in muscle disorders. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Effect of aging and degeneration on disc volume and shape: A quantitative study in asymptomatic volunteers
Authors: Pfirrmann Christian W. A. , Metzdorf Alexander , Elfering Achim , Hodler Juerg , Boos Norbert
Published: April 2006

Debate continues on the effect of disc degeneration and aging on disc volume and shape. So far, no quantitative in vivo MRI data is available on the factors influencing disc volume and shape. The objective of this MRI study was to quantitatively investigate changes in disc height, volume, and shape as a result of aging and/or degeneration omitting pathologic (i.e., painful) disc alterations. Seventy asymptomatic volunteers (20–78 years) were investigated with sagittal T1‐ and T2‐weighted MR‐images encompassing the whole lumbar spine. Disc height was determined by the Dabbs method and the Farfan index. Disc volume was calculated by the Cavalieri method. For the disc shape the “disc convexity index” was calculated by the ratio of central disc height and mean anterior/posterior disc height. Disc height, disc volume, and the disc convexity index measurements were corrected for disc level and the individuals age, weight, height, and sex in a multilevel regression analysis. Multilevel regression analysis showed that disc volume was negatively influenced by disc degeneration (p < 0.001) and positively correlated with body height (p < 0.001) and age (p < 0.01). Mean disc height and the disc convexity index were negatively influenced by disc degeneration but not by gender, weight, and height. Disc height was positively correlated with age (p < 0.01). From the results of this study, it can be concluded that disc degeneration generally results in a decrease of disc height and volume as well as a less convex disc shape. In the absence of disc degeneration, however, age tends to result in an inverse relationship on disc height, volume, and shape. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Six DOF in vivo kinematics of the ankle joint complex: Application of a combined dual‐orthogonal fluoroscopic and magnetic resonance imaging technique
Authors: de Asla Richard J. , Wan Lu , Rubash Harry E. , Li Guoan
Published: April 2006

Accurate knowledge of in vivo ankle joint complex (AJC) biomechanics is critical for understanding AJC disease states and for improvement of surgical treatments. This study investigated 6 degrees‐of‐freedom (DOF) in vivo kinematics of the human AJC using a combined dual‐orthogonal fluoroscopic and magnetic resonance imaging (MRI) technique. Five healthy ankles of living subjects were studied during three in vivo activities of the foot, including maximum plantarflexion and dorsiflexion, maximum supination and pronation, and three weight‐bearing positions in simulated stance phases of walking. A three‐dimensional (3D) computer model of the AJC (including tibia, fibula, talus, and calcaneus) was constructed using 3D MR images of the foot. The in vivo AJC position at each selected position of the foot was captured using two orthogonally positioned fluoroscopes. In vivo AJC motion could then be reproduced by coupling the orthogonal images with the 3D AJC model in a virtual dual‐orthogonal fluoroscopic system. From maximum dorsiflexion to plantarflexion, the arc of motion of the talocrural joint (47.5 ± 2.2°) was significantly larger than that of the subtalar joint (3.1 ± 6.8°). Both joints showed similar degrees of internal–external and inversion–eversion rotation. From maximum supination to pronation, all rotations and translations of the subtalar joint were significantly larger than those of the talocrural joint. From heel strike to midstance, the plantarflexion contribution from the talocrural joint (9.1 ± 5.3°) was significantly larger than that of the subtalar joint (−0.9 ± 1.2°). From midstance to toe off, internal rotation and inversion of the subtalar joint (12.3 ± 8.3° and −10.7 ± 3.8°, respectively) were significantly larger than those of the talocrural joint (−1.6 ± 5.9° and −1.7 ± 2.7°). Strong kinematic coupling between the talocrural and subtalar joints was observed during in vivo AJC activities. The contribution of the talocrural joint to active dorsi‐plantarflexion was higher than that of the subtalar joint, whereas the contribution of the subtalar joint to active supination–pronation was higher than that of the talocrural joint. In addition, the talocrural joint demonstrated larger motion during the early part of stance phase while the subtalar joint contributes more motion during the later part of stance phase. The results add quantitative data to an in vivo database of normals that can be used in clinical diagnosis, treatment, and evaluation of the AJC after injuries. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Kinetics and mechanism of the oxidative regeneration of carbonyl compounds from oximes by pyridinium bromochromate
Authors: Sharma Pradeep K.
Published: April 2006

The oxidative deoximination of several aldo‐ and keto‐oximes by pyridinium bromochromate (PBC), in dimethylsulfoxide, exhibited a first‐order dependence on both the reductant (oxime) and the oxidant (PBC). The oxidation of ketoximes is slower than that of aldoximes. The rates of oxidation of aldoximes correlated well in terms of the Pavelich–Taft dual substituent‐parameter equation. The low positive value of polar reaction constant indicated a nucleophilic attack by a chromate‐oxygen on the carbon. The reaction is subject to steric hindrance by the alkyl groups. The reaction of acetaldoxime has been studied in 19 different organic solvents. The solvent effect has been analyzed by Taft's and Swain's multiparametric equations. A mechanism involving the formation of a cyclic intermediate, in the rate‐determining step, has been proposed. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 364–368, 2006
Complete assignments of 1H and 13C NMR spectral data for a novel diterpenoid from Semiaquilegia adoxoides
Authors: Niu Feng , Cui Zheng , Li Qin , Chang Haitao , Jiang Yong , Qiao Liang , Tu Peng‐fei
Published: April 2006

Semiaquilegoside A (1), a new diterpenoid, was isolated from the roots of Semiaquilegia adoxoides. Its chemical structure was established as 3β, 11‐ dihydroxy‐12‐O‐β‐D‐glucopyranosyl‐8,11,13‐abietatrien‐6‐one through spectroscopic techniques and chemical analysis. Copyright © 2006 John Wiley & Sons, Ltd.
Multifocal acquired demyelinating sensory and motor neuropathy presenting as a peripheral nerve tumor
Authors: Allen David C. , Smallman Clare A. , Mills Kerry R.
Published: April 2006

A man with multifocal acquired demyelinating sensory and motor neuropathy (MADSAM), or Lewis–Sumner syndrome, presented with a progressive left lumbosacral plexus lesion resembling a neurofibroma. After 7 years he developed a left ulnar nerve lesion with conduction block in its upper segment. Treatment with intravenous immunoglobulin improved the symptoms and signs of both lesions. We conclude that inflammatory neuropathy must be considered in the differential diagnosis of peripheral nerve tumors, and that unifocal lesions may precede multifocal involvement in MADSAM by several years. In addition, we discuss the clinical features in 9 patients attending a specialist peripheral nerve clinic and review the literature. Muscle Nerve, 2006
A case of Lewis–Sumner syndrome with conduction abnormalities only in the brachial plexus and roots
Authors: Dionne Annie , Brunet Denis
Published: April 2006

We present a case of subacute weakness of one hand with unusual sensory involvement including the upper thorax. Despite normal distal conduction studies, a clinical diagnosis of Lewis–Sumner syndrome was made and the patient responded well to intravenous immunoglobulins. Repeated studies after clinical exacerbation finally proved the demyelinating nature of the neuropathy using proximal magnetic nerve stimulation. This case underlies the importance of seeking proximal conduction blocks in patients with suspected demyelinating neuropathy. Muscle Nerve, 2006
Interrater reliability of the needle examination in lumbosacral radiculopathy
Authors: Kendall Richard , Werner Robert A.
Published: April 2006

Low back pain and lumbar radiculopathy are among the most common painful disorders affecting the adult population. This study hypothesizes that there is good correlation between the diagnostic impression of an unblinded electromyographer, using clinical and electromyographic information, and an independent electromyographer, who uses the needle examination only to assess for lumbar radiculopathy. This is a prospective, single‐blinded, observational pilot study. The needle examination was electronically recorded, reproduced, and shown to a second examiner, blinded to all clinical data. Diagnostic impressions from both examiners were recorded and evaluated for agreement. Six recorded cases were reviewed by 66 blinded examiners. Overall diagnostic agreement was 46.9% (60.5% faculty level, 28.5% resident level). Logistic regression shows a strong association between training level and agreement on diagnostic impression (odds ratio, 1.9; 95% confidence interval, 1.12–3.22; P = 0.019). This study shows that there is fair interrater reliability between faculty‐level examiners and poor reliability among resident‐level examiners when the needle examination is used to evaluate patients with lumbar radiculopathy. Muscle Nerve, 2006
Inappropriate surgeries resulting from misdiagnosis of early amyotrophic lateral sclerosis
Authors: Srinivasan Jayashri , Scala Stephanie , Jones H. Royden , Saleh Firas , Russell James A.
Published: April 2006

Initial symptoms of amyotrophic lateral sclerosis (ALS) may mimic radiculopathy, myelopathy, mononeuropathy, or arthropathy. A retrospective review of 260 consecutive patients with ALS evaluated between 1996 and 2004 revealed that 55 (21%) had had surgery within the 5 years prior to ALS diagnosis. Thirty‐four of these 55 (61%) had surgery for symptoms and signs that retrospectively were attributable to early manifestations of ALS. Misdiagnosis of early ALS may lead to unnecessary surgeries with their attendant potential complications. Muscle Nerve, 2006
The Characteristic‐Based Split (CBS) scheme—a unified approach to fluid dynamics
Authors: Nithiarasu P. , Codina R. , Zienkiewicz O. C.
Published: April 2006

This paper presents a comprehensive overview of the characteristic‐based methods and Characteristic‐Based Split (CBS) scheme. The practical difficulties of employing the original characteristic schemes are discussed. The important features of the CBS scheme are brought out by studying several problems of compressible and incompressible flows. All special consideration necessary for solving these problems are thoroughly discussed. The CBS scheme is presented in such a way that any interested researcher should be able to develop a code using the information provided. Several invicid and viscous flow examples are also provided to demonstrate the unified CBS approach. For sample two‐dimensional codes, input files and instructions, the readers are referred to ‘www.nithiarasu.co.uk’ Copyright © 2006 John Wiley & Sons, Ltd.
Charge distribution on thin conducting nanotubes—reduced 3‐D model
Authors: Chen Hui , Mukherjee Subrata
Published: April 2006

The subject of this paper is the calculation of charge distribution on the surfaces of thin conducting nanotubes in electrostatic problems, by the boundary element method (BEM). A line model of a nanotube is proposed here. This model overcomes the problem of dealing with nearly singular matrices that occur when the standard BEM is applied to very thin features (objects or gaps). This new approach is also very efficient. Numerical results are presented for selected examples. Copyright © 2006 John Wiley & Sons, Ltd.
Accelerating iterative solution methods using reduced‐order models as solution predictors
Authors: Markovinović R. , Jansen J. D.
Published: April 2006

We propose the use of reduced‐order models to accelerate the solution of systems of equations using iterative solvers in time stepping schemes for large‐scale numerical simulation. The acceleration is achieved by determining an improved initial guess for the iterative process based on information in the solution vectors from previous time steps. The algorithm basically consists of two projection steps: (1) projecting the governing equations onto a subspace spanned by a low number of global empirical basis functions extracted from previous time step solutions, and (2) solving the governing equations in this reduced space and projecting the solution back on the original, high dimensional one. We applied the algorithm to numerical models for simulation of two‐phase flow through heterogeneous porous media. In particular we considered implicit‐pressure explicit‐saturation (IMPES) schemes and investigated the scope to accelerate the iterative solution of the pressure equation, which is by far the most time‐consuming part of any IMPES scheme. We achieved a substantial reduction in the number of iterations and an associated acceleration of the solution. Our largest test problem involved 93 500 variables, in which case we obtained a maximum reduction in computing time of 67%. The method is particularly attractive for problems with time‐varying parameters or source terms. Copyright © 2006 John Wiley & Sons, Ltd.
A new finite element formulation for internal acoustic problems with dissipative walls
Authors: Larbi W. , Deü J.‐F. , Ohayon R.
Published: April 2006

This work concerns the variational formulation and the numerical computation of internal acoustic problems with absorbing walls. The originality of the proposed approach, compared to other existing methods, is the introduction of the normal fluid displacement field on the damped walls. This additional variable allows to transpose formulations in frequency domain to time domain when the fluid is described by a scalar field (pressure or fluid displacement potential). With this new scalar unknown, various absorbing wall models can be introduced in the variational formulation. Moreover, the associated finite element matrix system in symmetric form can be solved in frequency and time domain. Copyright © 2006 John Wiley & Sons, Ltd.
Combining interface damage and friction in a cohesive‐zone model
Authors: Alfano Giulio , Sacco Elio
Published: April 2006

A new method to combine interface damage and friction in a cohesive‐zone model is proposed. Starting from the mesomechanical assumption, typically made in a damage‐mechanics approach, whereby a representative elementary area of the interface can be additively decomposed into an undamaged and a fully damaged part, the main idea consists of assuming that friction occurs only on the fully damaged part. The gradual increase of the friction effect is then a natural outcome of the gradual increase of the interface damage from the initial undamaged state to the complete decohesion. Suitable kinematic and static hypotheses are made in order to develop the interface model whereas no special assumptions are required on the damage evolution equations and on the friction law. Here, the Crisfield's interface model is used for the damage evolution and a simple Coulomb friction relationship is adopted. Numerical and analytical results for two types of constitutive problem show the effectiveness of the model to capture all the main features of the combined effect of interface damage and friction. A finite‐step interface law has then been derived and implemented in a finite‐element code via interface elements. The results of the simulations made for a fibre push‐out test and a masonry wall loaded in compression and shear are then presented and compared with available experimental results. They show the effectiveness of the proposed model to predict the failure mechanisms and the overall structural response for the analysed problems. Copyright © 2006 John Wiley & Sons, Ltd.
A parallel hp‐FEM infrastructure for three‐dimensional structural acoustics
Authors: Dey Saikat , Datta Dibyendu K.
Published: April 2006

This paper describes a parallel three‐dimensional numerical infrastructure for the solution of a wide range of time‐harmonic problems in structural acoustics and vibration. High accuracy and rate of error‐convergence, in the mid‐frequency regime,is achieved by the use of hp‐finite and infinite element approximations. The infrastructure supports parallel computation in both single and multi‐frequency settings. Multi‐frequency solves utilize concurrent factoring of the frequency‐dependent linear algebraic systems and are naturally scalable. Scalability of large‐scale single‐frequency problems is realized by using FETI‐DP—an iterative domain‐decomposition scheme.

Numerical examples are presented to cover applications in vibratory response of fluid‐filled elastic structures as well as radiation and scattering from elastic structures submerged in an infinite acoustic medium. We demonstrate both the numerical accuracy as well as parallel scalability of the infrastructure in terms of problem parameters that include wavenumber and number of frequencies, polynomial degree of finite/infinite element approximations as well as the number of processors. Scalability and accuracy is evaluated for both single and multiple frequency sweeps on four high‐performance parallel computing platforms: SGI Altix, SGI Origin, IBM p690 SP and Linux‐cluster. Results show good performance on shared as well as distributed‐memory architecture. Copyright © 2006 John Wiley & Sons, Ltd.
Chemotherapy for myeloid malignancy in children with Fanconi anemia
Authors: Mehta Parinda A. , Ileri Talia , Harris Richard E. , Williams David A. , Mo Jun , Smolarek Teresa , Auerbach Arleen D. , Kelly Patrick , Davies Stella M.
Published: April 2006

Background

Children with Fanconi anemia (FA) have a markedly increased risk of developing myeloid malignancies. Historically, patients with FA and myeloid malignancy have extremely poor outcomes. There are currently no clinical trials or case series addressing the use of chemotherapy for children with FA, except in the context of preparative regimens for stem cell transplantation (SCT). In this report we describe the toxicity of a chemotherapy approach for patients with FA and myeloid malignancy to achieve cytoreduction prior to SCT.

Patients and Methods

Four patients with FA and myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) were treated with chemotherapy (fludarabine 30 mg/m2 and cytosine arabinoside 300 mg/m2 each on days 2–4 and granulocyte‐colony stimulating factor (G‐CSF) 5 µg/kg on days 1–5), termed reduced intensity FLAG prior to SCT.

Results

The chemotherapy was well tolerated with expected hematologic toxicity and no measurable toxicity in other organs. Two of the three patients with AML cleared blasts from their bone marrow. Reduction in marrow cellularity was also achieved in one patient with hypercellular MDS.

Conclusion

These data indicate that children with FA and myeloid malignancy can tolerate chemotherapy and achieve clearance of disease. It remains unclear whether pre‐SCT chemotherapy improves currently poor survival rates for SCT in FA patients with myeloid malignancies and further studies are needed to determine if there is a clinical role for this strategy. Pediatr Blood Cancer 2007;48:668–672. © 2006 Wiley‐Liss, Inc.
Effect of dialysis on all trans retinoic acid levels in a child with acute promyelocytic leukemia and renal failure
Authors: Rajpurkar Madhvi , Alcasabas Patricia , Warrier Indulekha , Valentini Rudolph P. , Fassinger Nancy , Frattarelli Daniel A.C. , Ravindranath Yaddanapudi
Published: April 2006

All trans retinoic acid (ATRA) combined with chemotherapy has become the mainstay of treatment for patients with acute promyelocytic leukemia (APL). Renal dysfunction (RD) is commonly seen in patients with APL. We describe a patient with APL and multi‐organ failure, who was on chronic veno‐venous hemofiltration followed by hemodialysis (HD) and later peritoneal dialysis (PD), who received ATRA. ATRA levels were assessed as the body clearance of ATRA in children on HD and/or PD was unknown. Neither HD nor PD significantly affected ATRA levels, suggesting that dose modifications of ATRA may not be necessary for children with these forms of renal replacement therapy. Pediatr Blood Cancer 2007;49:994–996. © 2006 Wiley‐Liss, Inc.
Morphology, tensile properties, and fracture toughness of epoxy/Al2O3 nanocomposites
Authors: Naous Walid , Yu Xiao‐Yan , Zhang Qing‐Xin , Naito Kimiyoshi , Kagawa Yutaka
Published: April 2006

Epoxy/Al2O3 nanocomposites were prepared using an epoxy resin, diglycidyl ether of bisphenol A, and cured with a polyoxypropylene diamine (Jeffamine D‐400). Transmission electron microscopy and wide angle X‐ray diffraction were employed to reveal the morphology of epoxy/Al2O3 nanocomposites. Dynamic mechanical analysis results showed that the storage modulus and the glass transition temperature (Tg) of epoxy were improved. Tensile strength and Young's modulus also increased with increasing Al2O3 loading. Fracture toughness, as indicated by the stress intensity factor, KQ, was determined using single edge notch bending method, and 40% increase in KQ was observed with only 2 vol % Al2O3. Scanning electron microscopy study of fracture surface showed a rather smooth and flat morphology for neat epoxy. However, massive plastic deformation was observed for epoxy/Al2O3 nanocomposites, leading to the significant increase in fracture toughness. The influence of spherical Al2O3 nanoparticles on thermophysical properties of epoxy was discussed and compared with that of sheet‐like nanoclays. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1466–1473, 2006