bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantifying the contributions of structure to annulus fibrosus mechanical function using a nonlinear, anisotropic, hyperelastic model
Authors: Guerin Heather Lynch , Elliott Dawn M. 
Published: December 2006

AbstractThe annulus fibrosus of the intervertebral disc is comprised of concentric lamella of oriented collagen fibers embedded in a hydrated proteoglycan matrix with smaller amounts of minor collagens, elastin, and small proteoglycans. Its structure and composition enable the disc to withstand complex loads and result in inhomogeneous, anisotropic, and nonlinear mechanical behaviors. The specific contributions of the annulus fibrosus constituent structures to mechanical function remain unclear. Therefore, the objective of this study was to use a structurally motivated, anisotropic, nonlinear strain energy model of annulus fibrosus to determine the relative contributions of its structural components to tissue mechanical behavior. A nonlinear, orthotropic hyperelastic model was developed for the annulus fibrosus. Terms to describe fibers, matrix, and interactions between annulus fibrosus structures (shear and normal to the fiber directions) were explicitly included. The contributions of these structures were analyzed by including or removing terms and determining the effect on the fit to multidimensional experimental data. Correlation between experimental and model‐predicted stress, a Bland‐Altman analysis of bias and standard deviation of residuals, and the contribution of structural terms to overall tissue stress were calculated. Both shear and normal interaction terms were necessary to accurately model multidimensional behavior. Inclusion of shear interactions more accurately described annulus fibrosus nonlinearity. Fiber stretch and shear interactions dominated contributions to circumferential direction stress, while normal and shear interactions dominated axial stress. The results suggest that interactions between fibers and matrix, perhaps facilitated by crosslinks, elastin, or minor collagens, augment traditional (i.e., fiber‐uncrimping) models of nonlinearity. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:508–516, 2007
Twenty Years of Polymer‐Clay Nanocomposites
Authors: Okada Akane , Usuki Arimitsu 
Published: December 2006

AbstractSummary: More than twenty years have passed since we invented PCN, in which only a few wt.‐% of silicate is randomly and homogeneously dispersed in the polymer matrix. When molded, these nanocomposites show superior properties compared to those of pristine polymers. The number of papers on PCN has increased rapidly in recent years, reaching over 500 in 2005 alone. Being pioneers of this new technology, we review its history relative to the following epochal events:

In 1985 we invented nylon 6‐clay hybrid (NCH), the first PCN.
In 1989, cars equipped with a NCH part were launched.
In 1997, Gilman found revolutionary fire retardancy in NCH.
In 1997, a PP‐clay nanocomposite was prepared using a compatibilizer.
In 1998, a compounding method for producing PCN was completed.
In 2002, Haraguchi invented a revolutionary nanocomposite hydrogel.

So far, only nylon‐clay nanocomposites have been used in practice, but other PCN will become increasingly useful in the future.SEM of etched NCH film.magnified imageSEM of etched NCH film.
Antipsychotic use in older adults with Parkinson's disease
Authors: Marras Connie , Kopp Alexander , Qiu Feng , Lang Anthony E. , Sykora Kathy , Shulman Kenneth I. , Rochon Paula A. 
Published: December 2006

AbstractThe choice of agents to treat psychotic symptoms in Parkinson's disease is important given the potential for antipsychotics to worsen Parkinsonism. The purpose of this study was to estimate the incidence of psychotic symptoms requiring treatment in individuals with Parkinson's disease after starting dopaminergic medications, and to describe the agents being selected as initial antipsychotic therapy. Using the administrative health care databases of Ontario, Canada, individuals 66 years of age or older with Parkinson's disease who were newly treated with dopaminergic agents were identified. Subsequent prescriptions for antipsychotic medications were then identified. A total of 10,347 older adults were newly started on dopaminergic agents between 1998 and 2003. The Kaplan–Meier estimate for the cumulative probability of requiring an antipsychotic at 7 years was 35%; 499 individuals (4.8%; 5.2/100 person–years) were prescribed an antipsychotic within 1 year of starting dopaminergic therapy. The proportion of initial antipsychotic prescriptions for typical antipsychotics decreased from 56% (42 of 75) in 1998 to 9% (8 of 88) in 2002. Antipsychotic use is common in individuals with Parkinsonism newly treated with dopaminergic medication. Typical antipsychotics are still commonly being chosen as first‐line agents for older patients, indicating a need for interventions to improve practice. © 2006 Movement Disorder Society
Prevalence of spinocerebellar ataxia type 2 mutation among Italian Parkinsonian patients
Authors: Modoni Anna , Contarino Maria Fiorella , Bentivoglio Anna Rita , Tabolacci Elisabetta , Santoro Massimo , Calcagni Maria Lucia , Tonali Pietro A. , Neri Giovanni , Silvestri Gabriella 
Published: December 2006

AbstractWe evaluated the prevalence of the SCA2 mutation among 224 Italian patients affected by typical Parkinsonism, including 145 sporadic and 79 familial forms. Pink1, Parkin, and LRRK2 gene mutations had been excluded previously. Molecular testing for the CAG expansion at the SCA 2 locus was performed on leukocyte DNA. Cloning and sequencing of the expanded allele was performed in patients positive for the SCA2 expansion. A 38 CAG expansion was detected in 1 of 79 families studied. The proband, a male age 67, and his sister, age 69, were both affected by a benign form of L‐dopa–responsive Parkinsonism not associated with cerebellar signs. The inheritance was autosomal dominant. The CAG expansion was stable through meiotic transmission: sequence analysis showed that the CAG stretch was interrupted by 3 CAA. Our study shows that CAG expansion at the SCA 2 locus may represent a genetic cause of familial L‐dopa–responsive Parkinsonism among Italian patients. The stability of the pathological CAG expansion detected in this family was related to the presence of CAA interruptions. These findings, together with literature data, suggest that the molecular intrinsic structure of the expanded allele may modulate the phenotypic expression of the SCA2 mutation. © 2006 Movement Disorder Society
Loss of dopaminergic responsiveness in a double lesion rat model of the Parkinson variant of multiple system atrophy
Authors: Köllensperger Martin , Stefanova Nadia , Reindl Markus , Poewe Werner , Wenning Gregor K. 
Published: December 2006

AbstractThe Parkinson variant of multiple system atrophy (MSA‐P) is a distinct atypical parkinsonian disorder with a loss of dopaminergic neurons comparable to that found in Parkinson's disease (PD). The additional loss of striatopallidal projections is thought to account for levodopa unresponsiveness in MSA‐P. Whereas histological features of MSA‐P have been successfully reproduced in the double lesion rat model, loss of levodopa responsiveness has so far not been demonstrated. In the current study, 6‐hydroxydopamine (6‐OHDA) induced unilateral lesions of the substantia nigra produced a marked contralateral forelimb stepping deficit, which improved significantly after challenge with levodopa (P < 0.001). This response was abolished by the subsequent striatal quinolinic acid (QA) lesion. In the cylinder test, the marked asymmetry observed after 6‐OHDA lesioning was reversed by levodopa to baseline levels. After QA, cylinder test performance under levodopa failed to reach baseline (P = 0.001) or 6‐OHDA + levodopa (P = 0.002) levels. Nigral cell loss (90% ± 5%) correlated with both stepping test (r = 0.608; P = 0.008) and cylinder test results (r = 0.656; P = 0.005). Lesion extent of the dorsal striatum correlated significantly with the loss of levodopa response (r = 0.593; P = 0.01) in the stepping test. These findings contribute further to the behavioral characterization of the double lesion rat model of MSA, improving its value in the evaluation of future neurorestorative strategies. © 2006 Movement Disorder Society
Randomized trial of the triple monoamine reuptake inhibitor NS 2330 (tesofensine) in early Parkinson's disease
Authors: Hauser Robert A. , Salin Laurence , Juhel Nolwenn , Konyago Victor L. 
Published: December 2006

AbstractThe objective of this study was to evaluate the efficacy and safety of three daily dosages of the triple monoamine reuptake inhibitor NS 2330 (tesofensine) compared to placebo as monotherapy in early Parkinson's disease (PD). In MPTP (1‐methyl 4‐phenyl‐tetrahydropyridine 1,2,3,6)‐lesioned marmosets, dopamine reuptake inhibitors have been demonstrated to reverse parkinsonian signs without evoking established dyskinesia. NS 2330 inhibits reuptake of dopamine, serotonin, and norepinephrine. We performed a proof‐of‐concept, randomized, double‐blind trial of NS 2330. Two hundred sixty‐one subjects with PD < 5 years and not receiving dopaminergic treatment were randomly assigned to daily treatment with NS 2330 at 0.25 mg, 0.5 mg, 1.0 mg, or placebo. Adjusted mean difference in total Unified Parkinson's Disease Rating Scale (UPDRS) scores from baseline to week 14 was −0.7 (P = 0.64) in the 0.25‐mg group, −1.3 (P = 0.41) in the 0.5‐mg group, and −1.7 (P = 0.27) in the 1.0‐mg group. The adjusted mean difference in total UPDRS score for the highest dose group (1.0 mg/day) was superior to placebo at week 6 (−3.1; P = 0.02), but this effect was not sustained. NS 2330 was generally well tolerated and the most commonly reported adverse events were constipation, insomnia, and dry mouth. Decreased body weight and elevated heart rate were common in the 1.0‐mg dosage group. At the dosages tested, NS 2330 did not provide significantly greater benefit than placebo. It is possible that inhibition of dopamine reuptake alone does not provide clinical benefit in early PD, adequate inhibition of dopamine reuptake was not achieved in this study, or countervailing physiologic mechanisms offset the potential benefit. © 2006 Movement Disorder Society
Parkinsonism and essential tremor in a family with pseudo‐dominant inheritance of PARK2: An FP‐CIT SPECT study
Authors: Pellecchia Maria Teresa , Varrone Andrea , Annesi Grazia , Amboni Marianna , Cicarelli Giulio , Sansone Valeria , Annesi Ferdinanda , Rocca Francesca Emanuela , Vitale Carmine , Pappatà Sabina , Quattrone Aldo , Barone Paolo 
Published: December 2006

AbstractWe report a family with 5 affected individuals manifesting either essential tremor (ET), Parkinsonism, or both, consistent with pseudo‐dominant inheritance of PARK2. Two homozygotes presented postural and kinetic tremor several years before the onset of Parkinsonism. Postural and kinetic tremor mimicking ET was the only feature in 1 homozygous and 2 heterozygous carriers of the mutation. Striatal dopamine transporter density was reduced in accordance with phenotype and number of mutated alleles. In 3 homozygotes and 1 heterozygote, a 2‐year follow‐up single photon emission computed tomography suggested no progression of nigrostriatal deficit. © 2006 Movement Disorder Society
Spinocerebellar ataxia 14: Novel mutation in exon 2 of PRKCG in a German family
Authors: Nolte Dagmar , Landendinger Melanie , Schmitt Eberhard , Müller Ulrich 
Published: December 2006

AbstractWe describe a novel mutation in the gene coding for protein kinase C gamma (PRKCG) in patients of a German family affected with slowly progressive gait ataxia, dysarthria, and nystagmus. The G/T missense mutation occurred in exon 2 of PRKCG and results in a substitution of glycine by valine (G63V) in the evolutionarily highly conserved cysteine‐rich region 1/C1 domain of PRKCG. Among the 20 mutations described to date, this is the first mutation located in exon 2 of PRKCG. © 2006 Movement Disorder Society
Auditory startle reaction in primary blepharospasm
Authors: Müller Jörg , Rinnerthaler Martina , Poewe Werner , Kofler Markus 
Published: December 2006

AbstractPrimary dystonia is associated with abnormal brainstem function, as shown by abnormalities of the blink reflex in blepharospasm (BSP) and of the auditory startle reaction in cervical dystonia. We examined the auditory startle reaction—a brainstem reflex elicited by an unexpected loud stimulus—in patients with primary BSP to expand knowledge on brainstem pathophysiology in primary focal dystonia. Thirteen patients with primary BSP were included and 13 age‐ and sex‐matched healthy volunteers served as controls. Auditory startle responses (ASRs) were elicited by binaural high‐intensity auditory stimuli, and reflex electromyographic activity was recorded simultaneously with surface electrodes bilaterally from masseter, orbicularis oculi, sternocleidomastoid, and biceps brachii muscles. Patients with BSP showed higher ASR probabilities (masseter, sternocleidomastoid, biceps brachii), shorter ASR onset latencies (masseter, orbicularis oculi, sternocleidomastoid), and larger ASR area‐under‐the‐curve (masseter, sternocleidomastoid) as compared with normal controls. Habituation of ASRs did not differ significantly between patients and controls. These results corroborate previous findings of increased brainstem excitability in primary BSP but point to a different pattern of brainstem dysfunction compared to cervical dystonia, indicating that different pathophysiological mechanisms are involved in the two types of focal dystonia. © 2006 Movement Disorder Society
Holmes‐like tremor of the lower extremity following brainstem hemorrhage
Authors: Walker Melanie , Kim Hojoong , Samii Ali 
Published: December 2006

AbstractHolmes tremor is an arrhythmic, 2‐ to 5‐Hz resting, postural, and kinetic upper extremity movement disorder that occurs weeks to months after acute mesencephalic pathology. We present a patient who developed tremor in three body parts postbrainstem hemorrhage with subsequent hypertrophic olivary degeneration and discuss the relevant clinical evolution. Our case is unique because in addition to expected upper extremity and cervical dystonic head tremors, the patient also developed a severe lower extremity movement disorder, which we believe to be a form of Holmes tremor. Tremor involving the lower extremity in this setting has not been previously reported. © 2006 Movement Disorder Society
Neuropathology of Parkinson's disease associated with the LRRK2 Ile1371Val mutation
Authors: Giordana Maria Teresa , D'Agostino Carla , Albani Giovanni , Mauro Alessandro , Di Fonzo Alessio , Antonini Angelo , Bonifati Vincenzo 
Published: December 2006

AbstractLeucine‐Rich Repeat Kinase 2 (LRRK2) gene mutations are the most common known cause of Parkinson's disease (PD), but neuropathological studies are available on very few patients with LRRK2 mutation. The reported findings range from Lewy body–positive pathology to different pathologies, including nigral degeneration without distinctive features, neuronal loss with only ubiquitin‐positive inclusions, and tau‐positive–only pathology. Here we report the first neuropathological study in an Italian PD case carrying a different LRRK2 mutation, Ile1371Val, and showing typical ubiquitin‐ and α‐synuclein–positive Lewy body pathology. These findings support the concept that the neurodegeneration associated with LRRK2 mutations might be clinically and pathologically indistinguishable from typical PD. © 2006 Movement Disorder Society
A three‐dimensional model of an underground excavation and comparison with in situ measurements
Authors: Exadaktylos G. , Tsouvala S. , Liolios P. , Barakos G. 
Published: December 2006

AbstractIn this paper we make the first attempt to construct a three‐dimensional (3D) distinct element model (DEM) of an underground room with a central pillar in Dionysos marble deposit. This model can be employed in the future by the quarrymen to improve the design of the underground quarry. In order to decrease the effort and time of the simulations, the approach followed here is first to upscale intact rock properties to the size of the pillar considering also secondary joints, and next to model explicitly the major joint sets that transect the marble by virtue of a 3D DEM. The estimation of the effective marble properties is based on the concept of ‘damage’ as it is defined in damage mechanics theory, the phenomenon of the size effect of strength of intact rocks and the Rock Mass Rating (RMR) classification. Furthermore, a pre‐processor has been written in C language for the efficient transfer of the large number of successive excavations around the central pillar to the 3D numerical model. Finally, the validity of this first series of numerical simulations, results and inherent assumptions are checked against in situ stress and deformation measurements inside the underground quarry. Copyright © 2006 John Wiley & Sons, Ltd.
Presentation and management of major complications of midurethral slings: Are complications under‐reported?
Authors: Deng Donna Y. , Rutman Matthew , Raz Shlomo , Rodriguez Larissa V. 
Published: December 2006

AbstractAimsMidurethral slings have become the mainstay of stress urinary incontinence (SUI) treatment due to their efficacy and low complication rates. The purpose of this study was to report the presentation and treatment of major complications from these minimally invasive treatments presented to a tertiary referral practice and to highlight a discrepancy in major complications between literature and the food and drug administration (FDA) device failure database.MethodsFrom 2001 through 2005, we reviewed all cases of midurethral sling complications that presented to our institution. A literature review of all complications due to midurethral slings during the same time period was performed as was the FDA manufacturer and user facility device experience (MAUDE) database queried for self‐reported complications.ResultsA total of 26 patients referred to UCLA with voiding dysfunction after sling placement was found to have mesh in the urethra or bladder. Treatments required a combination of urethrolysis with mesh removal, urethral reconstruction with graft, and bladder excision. These were compared to major complications reported in the world literature of <1%. The MAUDE database contained 161 major complications out of a total of 928 complications reported for suburethral slings. There was significantly more major complications reported in MAUDE than in published literature.ConclusionsAlthough rare, major complications of midurethral slings are more common than appear in literature. Devastating complications involving urethral and bladder perforations can present with mild urinary symptoms and thus are likely under‐diagnosed and under‐reported. Most of these cases need to be managed with additional reconstructive surgery. Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.
On positive definite solution of a nonlinear matrix equation
Authors: Peng Zhen‐yun , El‐Sayed Salah M. 
Published: December 2006

AbstractIn this paper, some necessary and sufficient conditions for the existence of the positive definite solutions for the matrix equationX+A*X−αA=Qwith α ∈ (0, ∞) are given. Iterative methods to obtain the positive definite solutions are established and the rates of convergence of the considered methods are obtained. Copyright © 2006 John Wiley & Sons, Ltd.
Optimal Gerschgorin‐type inclusion intervals of singular values
Authors: Li Hou‐Biao , Huang Ting‐Zhu , Li Hong , Shen Shu‐Qian 
Published: December 2006

AbstractIn this paper, some optimal inclusion intervals of matrix singular values are discussed in the set ΩA of matrices equimodular with matrix A. These intervals can be obtained by extensions of the Gerschgorin‐type theorem for singular values, based only on the use of positive scale vectors and their intersections. Theoretic analysis and numerical examples show that upper bounds of these intervals are optimal in some cases and lower bounds may be non‐trivial (i.e. positive) when PA is a H‐matrix, where P is a permutation matrix, which improves the conjecture in Reference (Linear Algebra Appl 1984; 56:105‐119). Copyright © 2006 John Wiley & Sons, Ltd.
Coupled thermo/hydro/chemical/mechanical model for unsaturated soils—Numerical algorithm
Authors: Seetharam S. C. , Thomas H. R. , Cleall P. J. 
Published: December 2006

AbstractThis paper presents the implementation of a numerical algorithm for a new coupled thermal–hydraulic–chemical–mechanical model for unsaturated soil. A brief treatment of the theoretical development of the coupled model is presented first, with specific attention to the multi‐component chemical transport theory and its cross couplings with other primary variables. The system of coupled equations is based on a mechanistic approach with conservation of mass or energy equations defining the flow behaviour and a stress–strain equilibrium equation defining the mechanical behaviour. The geochemical interactions are incorporated by linking a geochemical model with the system of coupled flow and deformation equations. Two coupling strategies, namely, sequential non‐iterative and sequential iterative approaches are incorporated to link the multi‐component chemical transport equation with geochemical interactions. The model's ability is then demonstratedviaa series of 1D examples, which consider complex coupling scenarios involving all the primary variables. Specifically, the effects of multi‐component precipitation/dissolution and ion exchange reactions in a variable thermal–hydraulic–mechanical field are considered. The numerical efficiency of the model is also analysed based on these examples. It is concluded that the model not only provides a stable solution but is able to produce results that are qualitatively consistent with observed behaviour. Copyright © 2006 John Wiley & Sons, Ltd.
Sorption and diffusion of water into melamine–formaldehyde‐incorporated poly(vinyl acetate)–polyester nonwoven fabric composites
Authors: Satheesh Kumar Maddur Nagaraju , Siddaramaiah  
Published: December 2006

AbstractA series of composites were fabricated by impregnating a polyester nonwoven fabric with melamine–formol (MF)‐incorporated poly(vinyl acetate) (PVAc) latex. The effect of different weight ratios of MF/PVAc, i.e. 0/100, 5/100, 10, 100, 15/100 and 20/100 (dry, wt/wt), on the water sorption and diffusion into the composites was evaluated. Water sorption studies were carried out at different temperatures, i.e. 30, 50 and 70 °C, based on the immersion weight gain method. From the sorption results, the diffusion (D) and permeation (P) coefficients of water penetrant were calculated. A significant increase in the diffusion and permeation coefficients was observed with an increase in the temperature of sorption. Drastic reductions in diffusion and permeation coefficients were noticed with increasing MF content in the composites. Attempts were made to estimate the empirical parameters liken, which suggests the mode of transport, andK, a constant which depends on the structural characteristics of the composite in addition to its interaction with water. The temperature dependence of the transport coefficients was used to estimate the activation energy parameters for diffusion (ED) and permeation (Ep) processes from Arrhenius plots. Copyright © 2006 Society of Chemical Industry