bluuebunny/crossref_metadata_2025 huggingface dataset:
Toward a physical understanding of electron‐sharing two‐center bonds. I. General aspects
Authors: Bitter T. , Ruedenberg K. , Schwarz W. H. E.
Published: December 2006

In 1916, Lewis and Kossel laid the empirical ground for the electronic theory of valence, whose quantum theoretical foundation was uncovered only slowly. We can now base the classification of the various traditionalchemicalbond types in a threefold manner on the one‐ and two‐electron terms of the quantum‐physicalHamiltonian (kinetic, atomic core attraction, electron repulsion). Bond formation is explained by splitting up the real process into two physical steps: (i) interaction of undeformed atoms and (ii) relaxation of this nonstationary system. We aim at a flexible bond energy partitioning scheme that can avoid cancellation of large terms of opposite sign. The driving force of covalent bonding is a lowering of the quantum kinetic energy density by sharing. The driving force of heteropolar bonding is a lowering of potential energy density by charge rearrangement in the valence shell. Although both mechanisms are quantum mechanical in nature, we can easily visualize them, since they are of one‐electron type. They are however tempered by two‐electron correlations. The richness of chemistry, owing to the diversity of atomic cores and valence shells, becomes intuitively understandable with the help of effective core pseudopotentials for the valence shells. Common conceptual difficulties in understanding chemical bonds arise from quantum kinematic aspects as well as from paradoxical though classical relaxation phenomena. On this conceptual basis, a dozen different bond types in diatomic molecules will be analyzed in the following article. We can therefore examine common features as well as specific differences of various bonding mechanisms. © 2006 Wiley Periodicals, Inc. J Comput Chem 28: 411–422, 2007
Electronic reorganization: Origin of sigma trans promotion effect
Authors: Khoroshun Dmitry V. , Musaev Djamaladdin G. , Morokuma Keiji
Published: December 2006

Binding of two ligands trans to each other by some transition metal complexes may be cooperative [Khoroshun et al., Mol Phys 2002, 100, 523]. Several interesting consequent effects include (i) inverse relationship between bond strength and binding affinity; (ii) smaller coordination barriers to formation of weaker bonds; (iii) enhancement of Lewis acidity with increased number of ligands. We describe a simple model, σ trans promotion effect (TPE), which considers electronic reorganization between two Lewis structures, and predicts the above‐mentioned effects. The applied result of present study is the unified perspective on several facts of heme chemistry. Particularly, we reiterate an important but often overlooked notion, developed previously within the spin pairing model [Drago and Corden, Acc Chem Res 1980, 13, 353], that, in hemoproteins, the proximal histidine and the distal ligand such as O2 or CO cooperate in promoting electronic reorganization. As a result, depopulation of d orbital upon ligand binding contributes to the phenomenon of hemoglobin cooperativity. The presented density functional (B3LYP) calculations on realistic models, the processes of carbon monoxide binding by Fe(II) porphyrins and dinitrogen binding by triamido/triamidoamine Mo(III) complexes, particularly the evaluation of the coordination barriers due to spin‐state change by location of the minima on seams of crossing, support the TPE model predictions. From a broader theoretical perspective, the present study would hopefully stimulate the development of much needed frameworks and tools for facile comparisons of wave functions and their properties between different geometries, species, and electronic states. Advancement of practical wave function comparisons may yield fresh qualitative perspectives on chemical reactivity, and promote better understanding of related concepts such as electronic reorganization. © 2006 Wiley Periodicals, Inc. J Comput Chem 28: 423–441, 2007
Why does electron sharing lead to covalent bonding? A variational analysis
Authors: Ruedenberg Klaus , Schmidt Michael W.
Published: December 2006

Ground state energy differences between related systems can be elucidated by a comparative variational analysis of the energy functional, in which the concepts of variational kinetic pressure and variational electrostatic potential pull are found useful. This approach is applied to the formation of the bond in the hydrogen molecule ion. A highly accurate wavefunction is shown to be the superposition of two quasiatomic orbitals, each of which consists to 94% of the respective atomic 1s orbital, the remaining 6% deformation being 73% spherical and 27% nonspherical in character. The spherical deformation can be recovered to 99.9% by scaling the 1s orbital. These results quantify the conceptual metamorphosis of the free‐atom wavefunction into the molecular wavefunction by orbital sharing, orbital contraction, and orbital polarization. Starting with the 1s orbital on one atom as the initial trial function, the value of the energy functional of the molecule at the equilibrium distance is stepwise lowered along several sequences of wavefunction modifications, whose energies monotonically decrease to the ground state energy of H. The contributions of sharing, contraction and polarization to the overall lowering of the energy functional and their kinetic and potential components exhibit a consistent pattern that can be related to the wavefunction changes on the basis of physical reasoning, including the virial theorem. It is found that orbital sharing lowers the variational kinetic energy pressure and that this is the essential cause of covalent bonding in this molecule. © 2006 Wiley Periodicals, Inc. J Comput Chem 28: 391‐410, 2007
Globalisation and poverty: impacts on households of employment and restructuring in the textiles industry of South Africa
Authors: Bezuidenhout Andries , Khunou Grace , Mosoetsa Sarah , Sutherland Kirsten , Thoburn John
Published: December 2006

This paper addresses an important but often neglected theme in debates on globalisation—the consequences for workers of engagement in global markets, particularly for those workers who are retrenched in the process. Using the South African textiles industry as a case study, the paper investigates the impact on workers' household livelihoods of industrial restructuring following trade liberalisation in the 1990s. Interviews with textile workers and retrenched textile workers were conducted in five locations in three provinces—the Western Cape, the Eastern Cape and KwaZulu‐Natal—in order to capture different local dynamics. Workers employed in textiles generally enjoy a relatively stable formal sector wage, which, though less than the manufacturing average, is well above the national poverty line. However, the benefits were not evenly spread between the regions and job insecurity has been increasing. Workers retrenched from textile employment have faced extreme difficulties in a country with exceptionally high levels of open unemployment, and many families have fallen into deep poverty, which may now be transmitted intergenerationally. Copyright © 2006 John Wiley & Sons, Ltd.
Travel and communication and international differences in GDP per capita
Authors: Anderson Edward
Published: December 2006

Economic theory predicts that wage and income levels will be higher in those developing countries to which business travel and telecommunication from developed countries is cheaper and easier. Cross‐country regression analysis, using data from the World Tourism Organisation and the method of two‐stage least squares, supports this prediction. Levels of per capita GDP are higher in those developing countries which receive higher inflows of business travel from other countries, even when controlling for other influences on per capita GDP with which those inflows are correlated. There is also evidence that governments in developing countries can attract higher inflows of business travel from developed countries by investing in travel and communications infrastructure. Copyright © 2006 John Wiley & Sons, Ltd.
Antimicrobial susceptibility of coagulase‐negative staphylococci on tissue allografts and isolates from orthopedic patients
Authors: Saegeman Veroniek , Lismont Daniel , Verduyckt Bert , Ectors Nadine , Stuyck Jos , Verhaegen Jan
Published: December 2006

Allograft infection occurs at a rate not different from that of similar procedures with large allografts or sterilized prosthetic devices and is usually caused by coagulase‐negative staphylococci (CNS). CNS are feared for their limited antimicrobial susceptibility. We aimed at investigating this risk. CNS were isolated from 260 of 1461 allograft tissue grafts and compared with 384 consecutive clinical isolates from a general orthopedic population (258 patients). The CNS were identified and examined for their susceptibility to nine antibiotics used in routine practice. Staphylococcus epidermidis was the most commonly identified (35%) and the most resistant species of the allograft isolates. Comparing the overall antibiotic susceptibility patterns, clinical pathogens were significantly more resistant to six of the nine antibiotics (p < 0.01), namely penicillin, oxacillin, erythromycin, clindamycin, ofloxacin, and gentamicin. In conclusion, massive allograft infection is a well‐known life‐threatening surgical risk. However, we did demonstrate that allograft‐related in contrast to orthopedic clinics‐related CNS, are susceptible to commonly used first and second line antibiotics. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:501–507, 2007
Retraining cervical joint position sense: The effect of two exercise regimes
Authors: Jull Gwendolen , Falla Deborah , Treleaven Julia , Hodges Paul , Vicenzino Bill
Published: December 2006

This study compared the effects of conventional proprioceptive training and craniocervical flexion (C‐CF) training on cervical joint position error (JPE) in people with persistent neck pain. The aim was to evaluate whether proprioceptive training was superior in improving proprioceptive acuity compared to another form of exercise, which has been shown to be effective in reducing neck pain. This may help to differentiate the mechanisms of effect of such interventions. Sixty‐four female subjects with persistent neck pain and deficits in JPE were randomized into two exercise groups: proprioceptive training or C‐CF training. Exercise regimes were conducted over a 6‐week period, and all patients received personal instruction by an experienced physiotherapist once per week. A significant pre‐ to postintervention decrease in JPE, neck pain intensity, and perceived disability was identified for both the proprioceptive training group (p < 0.001) and the C‐CF training group (p < 0.05). Patients who participated in the proprioceptive training demonstrated a greater reduction in JPE from right rotation compared to the C‐CF training group (p < 0.05). No other significant differences were observed between the two groups. The results demonstrated that both proprioceptive training and C‐CF training have a demonstrable benefit on impaired cervical JPE in people with neck pain, with marginally more benefit gained from proprioceptive training. The results suggest that improved proprioceptive acuity following intervention with either exercise protocol may occur through an improved quality of cervical afferent input or by addressing input through direct training of relocation sense. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 2007
Kinematic changes of the foot and ankle in patients with systemic rheumatoid arthritis and forefoot deformity
Authors: Khazzam Michael , Long Jason T. , Marks Richard M. , Harris Gerald F.
Published: December 2006

Minimal published data exist characterizing the effect of rheumatoid arthritis of the forefoot (RA) on multi‐segmental gait kinematics. The purpose of this study was to examine specific changes in segmental foot motion in patients with RA as compared to persons without foot/ankle pathology. This was a cross‐sectional, descriptive study consisting of 22 preoperative adult patients (29 feet) diagnosed with RA and 25 adult patients with no known foot pathology (Control). All RA patients were evaluated by the same orthopaedic surgeon. This group consisted of 20 women and 2 men with a mean age of 54 years (range, 17–76 years). The Control cohort consisted of 13 men and 12 women with a mean age of 41 years (range, 27–73 years). Foot and ankle motion data for the RA population were obtained using a 15‐camera Vicon Motion Analysis System (Vicon Motion Systems, Inc., Lake Forest, CA). Anterior–posterior, lateral, and modified coronal radiographic views were obtained to relate marker position to underlying bony anatomy. Temporal and three‐dimensional kinematic parameters were obtained via the 4‐segment Milwaukee Foot Model. Quantitative comparisons of range of motion values during the seven phases of gait were made between RA and Control ankles using unpaired nonparametric methods. The RA group showed significant differences (p < 0.001) as compared to Controls with prolonged stance time, shortened stride length, increased cadence, and a walking speed that was 80% of Control. Overall, kinematic data in the RA cohort showed significant differences (p < 0.001) in motion for tibial, hindfoot, and forefoot motion as compared to Controls. The effect of RA on segmental foot motion is poorly understood. This study characterized the effect that RA has on motion about the foot and ankle during gait, providing insight into this pathology to improve quantitative assessment, treatment planning, and rehabilitative care. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 2007
Symposium on the musculoskeletal aspects of marfan syndrome: Meeting report and state of the science
Authors: Jones Kevin B. , Sponseller Paul D. , Erkula Gurkan , Sakai Lynn , Ramirez Francesco , Dietz Harry C. , Kost‐Byerly Sabine , Bridwell Keith H. , Sandell Linda
Published: December 2006

The National Marfan Foundation sponsored a symposium in August 2005 to review recent progress in the area of Marfan‐related musculoskeletal research. Orthopaedic surgeons, molecular geneticists, medical geneticists, and pain specialists met to review a variety of topics. This report reviews and summarizes the proceedings of the symposium, with emphasis on future directions for study that were identified in the course of the meeting. Areas covered include clinical detection, diagnosis, growth, spine deformity, molecular mechanisms, dural ectasia, protrusio acetabuli, and pain in Marfan syndrome. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 2007
Increased accumulation of superficial zone protein (SZP) in articular cartilage in response to bone morphogenetic protein‐7 and growth factors
Authors: Khalafi Afshin , Schmid Thomas M. , Neu Corey , Reddi A. Hari
Published: December 2006

The purpose of this study was to investigate the role of bone morphogenetic proteins (BMPs), such as BMP‐7, growth factors, and cytokines, in the accumulation of superficial zone protein (SZP) in bovine articular cartilage. Calf superficial articular cartilage discs and chondrocytes were obtained for explant and monolayer culture systems, respectively. Dose‐ and time‐dependent actions of BMP‐7 on SZP accumulation were investigated in both explant and monolayer culture systems. In addition, actions of various morphogens and growth factors [BMP‐2, BMP‐4, fibroblast growth factor 2 (FGF‐2), insulin‐like growth factor 1 (IGF‐1), platelet‐derived growth factor (PDGF), and transforming growth factor β (TGF‐β1)], and cytokines [interleukin (IL)‐1α, IL‐1β, and tumor necrosis factor (TNF‐α)] alone, and in combination with BMP‐7, on SZP accumulation were investigated in monolayer culture systems. SZP accumulation was quantified in both the cartilage and the medium using SDS‐PAGE and subsequent immunoblotting. In both explant and monolayer cultures, BMP‐7 increased SZP accumulation in a dose‐ and time‐dependent fashion (p < 0.05). Furthermore, SZP accumulation was significantly increased in monolayer cultures by FGF‐2, IGF‐1, PDGF, and TGF‐β1 (p < 0.05). Both IL‐1α and TNF‐α significantly reduced SZP accumulation (p < 0.05). The inhibition of SZP accumulation by TNF‐α was partially alleviated by concurrent treatment with BMP‐7. The results of this investigation provide novel insights into the role of morphogens, especially BMP‐7, growth factors, and cytokines in the accumulation of SZP in articular cartilage. This information has clinical implications because stimulation of SZP may ameliorate the pathology of joint function in arthritis. Furthermore, tissue engineering approaches to articular cartilage may depend on the optimal synthesis and assembly of SZP in the superficial zone to ensure functional tissue architecture. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 2007
Turbulence monitoring with Doppler Optical Coherence Tomography
Authors: Bonesi M , Churmakov D Y , Ritchie L J , Meglinski I V
Published: December 2006

The study of flow dynamics in micro vessels is highly important in rheology and cardiology to enable a better understanding of the effect of blood flow on the possible rupture of atherosclerotic plaques. Doppler Optical Coherence Tomography is able to provide a very high velocity resolution down to 10 μm s-1. The technique offers the potential to achieve a more detailed analysis of the flow/vessel interactions than current clinical practice offers; allowing simultaneously high resolution imaging of the morphology and composition of the atherosclerotic plaque and of the flow velocity vectorial field distribution along the measured cross-section. We use Doppler Optical Coherence Tomography to image high-resolution one-dimensional and multi-dimensional velocity distribution profiles of Intralipid solution flowing in complex micro-channels. A set of T- and Y-shaped phantoms were built to study the interaction of the flow dynamics with different channel geometries and to map the related velocity profiles at several inlet volume flow rates. In the current report we demonstrate the possibility of the technique for quantitative observation of the turbulence of flows arising within the complex micro-channel phantoms.
Single Polyelectrolyte Microcapsules Fabricated By Glutaraldehyde‐Mediated Covalent Layer‐By‐Layer Assembly
Authors: Tong Weijun , Gao Changyou , Möhwald Helmuth
Published: December 2006

Summary: Single polyelectrolyte component microcapsules and multilayers, exemplified by poly(allylamine hydrochloride) (PAH), have been prepared using a method of glutaraldehyde (GA)‐mediated covalent layer‐by‐layer (LbL) assembly. The GA cross‐linking of the adsorbed PAH results in surfaces covered by reactive aldehyde groups, which can then react with PAH to result in another layer of covalently linked PAH. The repeated assembly of single polyelectrolyte in an LbL manner can be thus achieved. The PAH multilayers can grow linearly along with the layer number, and their thickness can be controlled at the nanometer scale, as verified by UV‐vis absorption spectrometry and ellipsometry. Single polyelectrolyte microcapsules are obtained after removal of the template cores at low pH. The morphology and integrity are confirmed by scanning force microscopy and confocal laser scanning microscopy.

Schematic illustration of the preparation of a single polyelectrolyte component microcapsule by GA‐mediated covalent LbL assembly.

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Schematic illustration of the preparation of a single polyelectrolyte component microcapsule by GA‐mediated covalent LbL assembly.
Creep Behavior of Polystyrene/Fluorohectorite Micro‐ and Nanocomposites
Authors: Siengchin Suchart , Karger‐Kocsis József
Published: December 2006

Summary: Pristine FH is incorporated into a PS matrix by melt blending with and without latex precompounding of PS and FH. Direct melt blending results in microcomposites, whereas the latex‐mediated (masterbatch) technique results in PS/FH nanocomposites. The tensile creep response of the micro‐ and nanocomposites are determined in short‐term creep tests. The resistance to creep is improved with increasing dispersion of FH in the PS matrix. Master curves (creep compliance vs. time), constructed based on isothermal creep tests performed in the temperature range between 5 and 45 °C, show that the FH reinforcement affects mostly the initial creep compliance (interphase effect). On the other hand, the stable creep is matrix (bulk) dominated. It is established that the Williams‐Landel‐Ferry equation is fairly applicable to the creep results.

Scheme of the change of creep compliance as a function of time for micro‐ and nanocomposites with an amorphous matrix.

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Scheme of the change of creep compliance as a function of time for micro‐ and nanocomposites with an amorphous matrix.
Particle Size Effects in TEMPO‐Mediated Radical Polymerization of Styrene in Aqueous Miniemulsion
Authors: Nakamura Tadashi , Zetterlund Per B. , Okubo Masayoshi
Published: December 2006

Summary: 2,2,6,6‐Tetramethylpiperidinyl‐1‐oxy (TEMPO)‐mediated radical polymerization of styrene in aqueous miniemulsion at 125 °C using sodium dodecylbenzenesulfonate and poly(vinyl alcohol), respectively, as colloidal stabilizers has been investigated. The particle size had a dramatic effect on the polymerization process. Decreasing particle size led to a markedly higher polymerization rate, but less control and a lower degree of livingness. For particles with diameters greater than approximately 170 nm, the polymerization behavior was essentially the same as in the corresponding bulk system. By varying the particle size within an appropriate range, it is possible to tune the polymerization such that the polymerization rate is increased while still maintaining reasonable control and livingness.

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Synthesis and Alignment of Iron Oxide Nanoparticles in a Regenerated Cellulose Film
Authors: Liu Shilin , Zhou Jinping , Zhang Lina , Guan Jianguo , Wang Jianbo
Published: December 2006

Summary: A polymer‐iron oxide nanocomposite film has been successfully synthesized by using a microporous regenerated cellulose film as template and aqueous ferrous chloride as precursor. The nanocomposite film was investigated with XRD, XPS, SEM, TEM, and VSM. The nanoparticles synthesized in situ were disk‐shaped with a mean diameter of ≈24 and thicknesses of 2.5–3.5 nm. For the first time, the nanodisks were well aligned in the cellulose matrix to form an ordered multibilayer structure by the shrinkage of the hybrid film while drying. The nanocomposite film displayed anisotropic magnetic properties as a result of the alignment of magnetic nanodisks. This work provides a novel and facile method for template synthesis of nanoparticles and aligned nanocomposites.

TEM image of the air‐dried nanocomposite film; slice perpendicular to the film plane.

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TEM image of the air‐dried nanocomposite film; slice perpendicular to the film plane.
Microwave‐Assisted Ring‐Opening Polymerization of ε‐Caprolactone in the Presence of Ionic Liquid
Authors: Liao Liqiong , Liu Lijian , Zhang Chao , Gong Shaoqin (Sarah)
Published: December 2006

Summary: Microwave‐assisted ring‐opening polymerization of ε‐caprolactone in the presence of 1‐butyl‐3‐methylimidazolium tetrafluoroborate ionic liquid using zinc oxide as a catalyst is investigated. By adding 30 wt.‐% ionic liquid, poly(ε‐caprolactone) with a weight‐average molar mass of 28 500 g · mol−1 is obtained at 85 W for 30 min. The results indicate that the polymerization could be efficiently enhanced in the presence of ionic liquids under microwave irradiation because ionic liquids can effectively absorb microwave energy.

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Halogen‐Free Polyarylphosphonates and Polyelectrolyte Membranes for PEMFC by Nickel‐Catalyzed Phosphonylation with Silylated Phosphates
Authors: Bock Thorsten , Mülhaupt Rolf , Möhwald Helmut
Published: December 2006

Summary: The nickel‐catalyzed arylphosphonylation with tris(trimethylsilyl) phosphite (TMSP) is applied to brominated high‐performance (HP) polymers in weakly coordinating high temperature solvents. At elevated temperatures, this affords halogen‐free, soluble, phosphonic acid‐functionalized polyelectrolytes and an unprecedented control of the degree of phosphonylation (dsP). Brominated polysulfone (PSU) of various degrees of bromination (dsBr) has been phosphonylated with TMSP in diphenyl ether at 200 °C in the presence of 1–10 mol‐% NiCl2. Upon methanolysis, arylphosphonic PSU with dsP up to 223 mol‐% is obtained in near quantitative bromine conversion. Catalyst residues are readily removed during methanolysis. This very versatile two‐step process affords soluble arylphosphonic polymers for casting tough membrane films. In contrast to sulfonated PSU, the arylphosphonic PSU membranes exhibit improved thermal and chemical stabilities, combined with far lower water swelling in accordance with the demands of polyelectrolyte membrane fuel cell (PEMFC) applications.

Mass swelling (swM) in water of sulfonated (A–C) and phosphonylated PSU (D).

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Mass swelling (swM) in water of sulfonated (A–C) and phosphonylated PSU (D).
Dimension estimate of the exponential attractor for the chemotaxis‐growth system
Authors: Efendiev Messoud , Kläre Michael , Lasser Rupert
Published: December 2006

We consider a chemotaxis‐growth model which takes into account diffusion, chemotaxis, production of chemical substance, and growth. We present estimates from above and below of the fractal dimension dim𝔐 of the exponential attractor 𝔐 in terms of the coefficients of the system. Comparisons are made between the sizes of the global and exponential attractors. Numerical simulations are presented which confirm the analytical results obtained. Copyright © 2006 John Wiley & Sons, Ltd.
Myopathy associated with anti–signal recognition peptide antibodies: Clinical heterogeneity contrasts with stereotyped histopathology
Authors: Dimitri Dalia , Andre Chantal , Roucoules Jacques , Hosseini Hassan , Humbel René‐Louis , Authier François‐Jérôme
Published: December 2006

We report three patients with anti–signal recognition particle antibodies who had different presenting clinical pictures, mimicking acute polymyositis, limb‐girdle muscular dystrophy, and acute rhabdomyolysis. Muscle biopsies typically showed necrotizing myopathy with little or no inflammation and deposits of membrane attack complex (C5b‐9) in endomysial capillaries. The clinical course was severe in two patients and mild in one. The combination of corticosteroid with either an immunosuppressive agent or intravenous immunoglobulins was required to improve the condition of these patients. Muscle Nerve, 2006
Epidemiology of cauda equina and conus medullaris lesions
Authors: Podnar Simon
Published: December 2006

The epidemiology of cauda equina and conus medullaris lesions is not well known, and this study aimed to provide further information on this topic. In the period 1996–2004, patients fulfilling the clinical, electrodiagnostic, and radiological criteria for such lesions were identified. For cauda equina/conus medullaris lesions an annual incidence rate of 3.4/1.5 per million, and period prevalence of 8.9/4.5 per 100,000 population were calculated. The values obtained are probably valid estimates of the incidence and prevalence of these lesions in developed countries. Muscle Nerve, 2006
Intrinsic laryngeal muscles are spared from myonecrosis in the mdx mouse model of Duchenne muscular dystrophy
Authors: Marques Maria Julia , Ferretti Renato , Vomero Viviane Urbini , Minatel Elaine , Neto Humberto Santo
Published: December 2006

Intrinsic laryngeal muscles share many anatomical and physiological properties with extraocular muscles, which are unaffected in both Duchenne muscular dystrophy and mdx mice. We hypothesized that intrinsic laryngeal muscles are spared from myonecrosis in mdx mice and may serve as an additional tool to understand the mechanisms of muscle sparing in dystrophinopathy. Intrinsic laryngeal muscles and tibialis anterior (TA) muscle of adult and aged mdx and control C57Bl/10 mice were investigated. The percentage of central nucleated fibers, as a sign of muscle fibers that had undergone injury and regeneration, and myofiber labeling with Evans blue dye, as a marker of myofiber damage, were studied. Except for the cricothyroid muscle, none of the intrinsic laryngeal muscles from adult and old mdx mice showed signs of myofiber damage or Evans blue dye labeling, and all appeared to be normal. Central nucleation was readily visible in the TA of the same mdx mice. A significant increase in the percentage of central nucleated fibers was observed in adult cricothyroid muscle compared to the other intrinsic laryngeal muscles, which worsened with age. Thus, we have shown that the intrinsic laryngeal muscles are spared from the lack of dystrophin and may serve as a useful model to study the mechanisms of muscle sparing in dystrophinopathy. Muscle Nerve, 2006
Mechanically evoked sensory and motor responses to dynamic compression of the ulnar nerve
Authors: Clarke Elizabeth C. , McNulty Penelope A. , Macefield Vaughan G. , Bilston Lynne E.
Published: December 2006

Mechanical deformation of a peripheral nerve can evoke action potentials in sensory and motor axons. The generation of these impulses with brief stimuli (<0.5 s) and their relationship to the deformation conditions have not been systematically studied in human subjects. Controlled compression stimuli over a range of amplitudes, durations, and loading rates were delivered to the ulnar nerve at the medial epicondyle in awake human subjects. Compound muscle action potentials were recorded from the first dorsal interosseous muscle. Subjects rated the magnitude of evoked paresthesias. Mechanically evoked motor and sensory responses varied linearly with the magnitude (P < 0.001) and rate of deformation (P < 0.01), but not the duration, and occurred only during the compression phase. Cutaneous axons had lower mechanical thresholds than motor axons. We relate these findings to the viscoelastic properties of peripheral nerves and differences in biophysical properties of cutaneous and motor axons. Muscle Nerve, 2006
Physical activity and motor decline in older persons
Authors: Buchman A.S. , Boyle P.A. , Wilson R.S. , Bienias Julia L. , Bennett D.A.
Published: December 2006

We tested the hypothesis that physical activity modifies the course of age‐related motor decline. More than 850 older participants of the Rush Memory and Aging Project underwent baseline assessment of physical activity and annual motor testing for up to 8 years. Nine strength measures and nine motor performance measures were summarized into composite measures of motor function. In generalized estimating equation models, global motor function declined during follow‐up (estimate, −0.072; SE, 0.008;P< 0.001). Each additional hour of physical activity at baseline was associated with about a 5% decrease in the rate of global motor function decline (estimate, 0.004; SE, 0.001;P= 0.007). Secondary analyses suggested that the association of physical activity with motor decline was mostly due to the effect of physical activity on the rate of motor performance decline. Thus, higher levels of physical activity are associated with a slower rate of motor decline in older persons. Muscle Nerve, 2006
Mechanomyographic and electromyographic responses to stimulated and voluntary contractions in the dorsiflexors of young and old men
Authors: Shima Norihiro , McNeil Chris J. , Rice Charles L.
Published: December 2006

The effect of age on mechanomyography (MMG) has not been examined for electrically evoked contractions. Similar to torque, we expected that postactivation potentiation of the MMG would differ between young and old subjects. Additionally, under voluntary conditions, we compared normalized MMG and electromyographic (EMG) signals in relation to torque, and expected that MMG, unlike EMG, would be affected by age. In 10 young and 10 old men, electrical stimulation was delivered before and after a 10‐s maximal voluntary contraction (MVC) to assess potentiation of contractile (twitch torque; Pt), electrical (M‐wave amplitude), and mechanical (MMG amplitude) properties of the dorsiflexors. Subsequently, subjects performed voluntary contractions at 20%, 40%, 60%, 80%, and 100% MVC for calculation of normalized MMG–torque and EMG–torque relationships. Following the MVC, Pt and evoked MMG were larger than at rest in both groups, but M‐wave amplitude was unchanged. Twitch potentiation was greater in young than old, whereas evoked MMG was unaffected by age. Under voluntary conditions, values for MMG and EMG were similar between groups, except for greater MMG at MVC in young men. The shape of MMG and EMG relationships to torque was similar only in young men. Using the aging model, our results indicate that potentiation of the mechanical components (MMG) differ from those of twitch torque. Furthermore, the comparison of normalized voluntary MMG with age provides additional support for the concept of age‐related motor unit remodeling. Muscle Nerve, 2006
Myopathy associated with gluten sensitivity
Authors: Hadjivassiliou Marios , Chattopadhyay Arup K. , Grünewald Richard A. , Jarratt John A. , Kandler Rosalind H. , Rao D. G. , Sanders D. S. , Wharton S. B. , Davies‐Jones G. A. B.
Published: December 2006

Ataxia and peripheral neuropathy are the most common neurological manifestations of gluten sensitivity. Myopathy is a less common and poorly characterized additional neurological manifestation of gluten sensitivity. We present our experience with 13 patients who presented with symptoms and signs suggestive of a myopathy and in whom investigation led to the diagnosis of gluten sensitivity. Three of these patients had a neuropathy with or without ataxia in addition to the myopathy. The mean age at onset of the myopathic symptoms was 54 years. Ten patients had neurophysiological evidence of myopathy. Inflammatory myopathy was the most common finding on neuropathological examination. One patient had basophilic rimmed vacuoles suggestive of inclusion‐body myositis. Six patients received immunosuppressive treatment in addition to starting on a gluten‐free diet; five improved and one remained unchanged. Among seven patients not on immunosuppressive treatment, four showed clinical improvement of the myopathy with a gluten‐free diet. The improvement was also associated with reduction or normalization of serum creatine kinase level. The myopathy progressed in one patient who refused the gluten‐free diet. Myopathy may be another manifestation of gluten sensitivity and is likely to have an immune‐mediated pathogenesis. A gluten‐free diet may be a useful therapeutic intervention. Muscle Nerve, 2006
A total ALE FE formulation for axisymmetric and torsional problems (including viscoplasticity, thermodynamic coupling and dynamics)
Authors: Celigoj C. C. , Außerlechner P.
Published: December 2006

This paper—first—extends a recent ‘assumed enhanced deformation gradient’ finite ring(segment) element (Int. J. Numer. Methods Eng. 2001; 50:899–918.) to Arbitary Lagrange Euler (ALE) computations, by setting up the assumed tensor on the computational configuration, and—second—shows an elegant way of incorporating dynamics into real ALE computations (no splitting into purely—Lagrange steps and then—remeshing steps), by introducing material mesh velocities and accelerations and spatial mesh velocities and accelerations. Copyright © 2006 John Wiley & Sons, Ltd.
Analysis of modified Reynolds equation using the wavelet‐multigrid scheme
Authors: Bujurke N.M. , Salimath C.S. , Kudenatti Ramesh B. , Shiralashetti S.C.
Published: December 2006

The combined study of effects of surface roughness and poroelasticity on the squeeze film behavior of bearings in general and that of synovial joints in particular are presented. The modified form of Reynolds equation, which incorporates the randomized roughness structure as well as elastic nature of articular cartilage, is derived. Christensen stochastic theory describing roughness structure of cartilage surfaces is used by assuming the roughness asperity heights to be small compared to the film thickness. A recently developed wavelet‐multigrid method is used for the solution of Reynolds equation. The method has the greatest advantage of minimizing the errors using wavelet transforms in obtaining accurate solution, as grid size tends to zero. Based on the results obtained, the influence of roughness and elasticity on bearing characteristics are discussed in some detail. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2007
Factors in successful program implementation in Russia during the transition: pilot programs as a guide
Authors: Struyk Raymond J.
Published: December 2006

While much of the implementation literature over the past several decades has recognised the importance of context (e.g. in issues of institutional culture, degree of hierarchy), little of the literature comparing the results of numerous program implementation experiences examines the experience of non‐Western contexts. This study seeks to partially fill this gap by applying the ‘conventional wisdom’ of implementation theory to program implementation experience in Russia. We analyse the implementation of 18 demonstration projects in Russia against 9 success factors identified in the implementation literature. Most of the pilots involved multiple cities; so there are a total of 48 city‐case observations to study. Overall, the findings are that the factors associated with successful program implementation among OECD countries are also those at work in Russia's transitional economy. The weights associated with the various factors may differ, however. One could imagine, for example, that political support counts for more in Russia than in the western local governments. One might also believe that opportunities for learning from other implementers could be more important in the West, where professional associations are more highly developed. The core finding of consistency should be valuable to administrators across transitional economies who can now refer to the rich findings of implementation research with greater confidence of its applicability to their programs. Perhaps equally important is the finding that some of the same factors predominantly associated with successful or troubled implementation in Russia have similar effects in implementation examples drawn from transition and developing nations; there are, however, some important differences. Copyright © 2006 John Wiley & Sons, Ltd.
Recombinant tissue plasminogen activator may reduce frequency of central venous access device infection in hemophilia patients undergoing immune tolerance therapy
Authors: Dunn Amy L. , Abshire Thomas C.
Published: December 2006

Many patients with hemophilia, particularly those with inhibitory antibodies, utilize central venous access devices (CVADs) to facilitate frequent infusions. Infection of these devices is a common complication of factor replacement therapy. This communication reports our center's experience with CVAD infection in three patients with severe hemophilia A undergoing immune tolerance therapy (ITT) in whom intermittent infusions of recombinant tissue plasminogen activator (rTPA, Cathflo™ Activase®) were utilized. In this small experience, patients experienced a decreased frequency of gram‐positive infections when receiving routine rTPA treatments. Larger randomized trial should be performed in this patient population at high risk of CVAD infection. Pediatr Blood Cancer 2008;50:627–629. © 2006 Wiley‐Liss, Inc.
Serum levels of mannose‐binding lectin and the risk of fever in neutropenia pediatric cancer patients
Authors: Schlapbach L.J. , Aebi C. , Otth M. , Luethy A. Ridolfi , Leibundgut K. , Hirt A. , Ammann R.A.
Published: December 2006

Background

Fever in neutropenia (FN) is a frequent complication in pediatric oncology. Deficiency of mannose‐binding lectin (MBL), an important component of innate immunity, is common due to genetic polymorphisms, but its impact on infections in oncologic patients is controversial. This study investigated whether MBL serum levels at cancer diagnosis are associated with the development of FN in pediatric cancer patients.

Procedure

Serum MBL was measured using ELISA. Frequency, duration, and cause of FN were assessed retrospectively. Association with MBL level was analyzed using uni‐ and multivariate Poisson regression taking into account both intensity and duration of chemotherapy.

Results

In 94 children, with a cumulative follow‐up time of 81.7 years, 177 FN episodes were recorded. Patients with both very low MBL levels (<100 µg/L; risk ratio (RR), 1.93; 95% CI, 1.14–3.28; P = 0.014) and normal MBL levels (≥1,000 µg/L; RR, P = 0.011) had significantly more frequent FN episodes than patients with low MBL levels (100–999 µg/L). Patients with very low MBL levels had significantly more episodes of FN with severe bacterial infection (bacteremia or pneumonia; RR, 4.49; 1.69 = 11.8; P = 0.003), while those with normal MBL levels had more FN episodes with no microbial etiology identified (RR, 1.85; 1.14 = 3.03; P = 0.014).

Conclusions

Very low MBL levels are associated with more frequent FN episodes, mainly due to severe bacterial infections. The surprising finding that children with normal MBL levels had more frequent FN episodes than those with low MBL levels needs testing in prospective studies. Pediatr Blood Cancer 2007;49:11–16. © 2006 Wiley‐Liss, Inc.
Characterisation of gamma‐irradiated polyetherimide films with infrared spectroscopy and thermally stimulated current measurements
Authors: Smaoui Hichem , Mzabi Nissaf , Guermazi Hajer , Mlik Youssef , Agnel Serge , Toureille Alain , Schué François
Published: December 2006

The performance of insulators is usually affected by the presence of space charges. The evolution of these charges under applied constraints in many cases leads to the degradation of these materials. To evaluate the performance of an insulator it is necessary to study the evolution of the physical and chemical properties in the presence of space charges. In this paper, the effect of gamma irradiation on the space charge behaviour in polyetherimide (PEI; Ultem 1000) has been investigated at different radiation doses. Space charge measurements were made using thermally stimulated currents. Infrared spectroscopy characterisation was performed to investigate the effect of gamma irradiation on the physicochemical properties of PEI. The results obtained show minor differences in the infrared spectra, mainly in the 410 cm−1 region. It is found that irradiation leads to a few structural changes in the material. The thermostimulated depolarisation current (TSDC) results show that β relaxations in PEI are affected by gamma irradiation. The activation energies of dipoles were calculated from the TSDC curves. Copyright © 2006 Society of Chemical Industry
Study of biomineralization of poly(vinyl alcohol)‐based scaffolds using an alternate soaking approach
Authors: Bajpai AK , Singh Raghvendra
Published: December 2006

The present work adds to the continuing efforts of designing a natural bone‐like structure by synthesizing a semi‐interpenetrating polymer network (IPN) of poly(vinyl alcohol)–poly[(acrylic acid)‐co‐acrylonitrile] and impregnating hydroxyapatite (HAP) into the polymer matrix by an alternate soaking process. The prepared HAP–polymer scaffolds were characterized using techniques like Fourier transform infrared spectroscopy, X‐ray diffraction, differential scanning calorimetry, thermogravimetric analysis and environmental scanning electron microscopy. The biomineralized semi‐IPN was evaluated for water sorption capacity and the data were utilized for calculating network parameters such as average molecular weight between crosslinks (Mc) and crosslink density (q). The impregnated HAP was quantified as a function of the chemical architecture of the semi‐IPN, number of reaction cycles and temperature of the swelling bath. Copyright © 2006 Society of Chemical Industry
Organosoluble and light‐colored fluorinated polyimides derived from 5,5′‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy) phenyl]‐4,7‐methanohexahydroindan
Authors: Yang Chin‐Ping , Su Yu‐Yang , Hsu Mei‐Yuan
Published: December 2006

A novel bis(ether amine) monomer, 5,5′‐bis[4‐(4‐amino‐2‐trifluoromethylphenoxy)phenyl]‐4,7‐methanohexahydroindan (2), was synthesized through the nucleophilic aromatic substitution reaction of 5,5′‐bis‐(4‐hydroxyphenyl)‐4,7‐methanohexahydroindan with 2‐chloro‐5‐nitrobenzotrifluoride to yield the intermediate dinitro compound, followed by catalytic reduction with hydrazine and Pd/C. A series of polyimides were synthesized from 2 and various aromatic dianhydrides using a standard two‐stage process with chemical or thermal imidization of poly(amic acid). All of these polymer films were soluble in amide‐type solvents above 10% w/v, had tensile strengths of 97–117 MPa, and the 10% weight loss temperature was above 464 °C with their residues exceeding 46% at 800 °C in nitrogen. Compared with the non‐fluorinated polyimides, the fluorinated series were observed to have lower dielectric constants (2.92–3.28 at 1 MHz) and lower moisture absorptions (0.15–0.43 wt%) as well as lower color intensity and better solubility. Copyright © 2006 Society of Chemical Industry
Characteristics of dual‐type electrochromic devices based on poly(ethylene oxide) copolymers
Authors: Yildiz Huseyin Bekir , Sahin Elif , Cirpan Ali , Toppare Levent , Yagci Yusuf
Published: December 2006

Dual‐type polymer electrochromic devices based on [(3‐thienyl)methylmethacrylate]‐co‐[p‐vinyl benzyloxy poly(ethylene oxide)]/polythiophene and thiophene‐capped poly(ethylene oxide)/polythiophene and ethylene dioxythiophene were constructed via electropolymerization. Spectroelectrochemistry, switching ability and stability of the devices were investigated using UV‐visible spectrophotometry and cyclic voltammetry. These devices exhibit low switching voltages and short switching times with reasonable switching stability under atmospheric conditions. Copyright © 2006 Society of Chemical Industry
Preparation, characterization, and mechanical properties of microcellular poly(aryl ether ketone) foams
Authors: Wang Dong , Jiang Wei , Gao Hong , Jiang Zhenhua
Published: December 2006

High‐performance microcellular closed‐cell foams were prepared by a two‐stage batch foaming process from fluorinated poly(ether ether ketone) and characterized by scanning electronic microscopy, tensile, and dynamic mechanical analysis (DMA). The effects of saturation pressure and temperature on the cell size, cell density, and bulk density of porous materials had been discussed. The resulting materials had average cell diameters in the range 3–17 μm, and cell densities (Nf) in the order of 0.6 × 109–1.39 × 1010 cells/cm3. The porosity (Vf) was in the range of 0.2–0.85. In contrast, experimental values of Young's moduli were in good agreement with theoretically predicted values, but the relative strengths were somewhat lower than that predicted. The relaxation mechanism of microcellular was systematically investigated by DMA. The dynamic mechanical spectrometry showed that the storage modulus curve at high temperature region appeared a peak and the loss modulus was lower as compared to their solid counterparts. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 173–183, 2007