bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of reference electrode position on the compound muscle action potential (CMAP) onset latency
Authors: Phongsamart Gulapar , Wertsch Jacqueline J. , Ferdjallah Mohammed , King John C. , Foster D. Terrence
Published: October 2002

Compound muscle action potential (CMAP) onset latency is interpreted to reflect the arrival time at the muscle of impulses in the fastest‐conducting motor nerve fiber. However, we have observed that the position of the reference or indifferent electrode (E2) affects CMAP onset latency. Motor nerve conduction studies (NCS) of the median, ulnar, and deep ulnar motor (DUM) nerves on 20 normal hands were performed using both traditional bipolar and experimental monopolar (referenced to the contralateral hand) montages. As the position of E2 was altered, the CMAP onset latency varied 0.1–0.5 ms for the median NCS, 0.1–0.3 ms for the ulnar NCS, and 0.1–1.5 ms for the DUM NCS. This study demonstrates that E2 recorded potentials are significant and vary with positioning, affecting motor onset latency. This has implications both for reference values and the physiologic interpretation of the CMAP waveform. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
GDNF is regulated in an activity‐dependent manner in rat skeletal muscle
Authors: Wehrwein Erica A. , Roskelley Eric M. , Spitsbergen John M.
Published: October 2002

Glial cell line–derived neurotrophic factor (GDNF) is produced by skeletal muscle and affects peripheral motor neurons. Elevated expression of GDNF in skeletal muscle leads to hyperinnervation of neuromuscular junctions, whereas postnatal administration of GDNF causes synaptic remodeling at the neuromuscular junction. Studies have demonstrated that altered physical activity causes changes in the neuromuscular junction. However, the role played by GDNF in this process in not known. The objective of this study was to determine whether changes in neuromuscular activity cause altered GDNF content in rat skeletal muscle. Following 4 weeks of walk‐training on a treadmill, or 2 weeks of hindlimb unloading, soleus, gastrocnemius, and pectoralis major were removed and analyzed for GDNF content by enzyme‐linked immunosorbant assay. Results indicated that walk‐training is associated with increased GDNF content. Skeletal muscle from hindlimb‐unloaded animals showed a decrease in GDNF in soleus and gastrocnemius, and an increase in pectoralis major. The altered production of GDNF may be responsible for activity‐dependent remodeling of the neuromuscular junction and may aid in recovery from injury and disease. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 206–211, 2002
Reduced thrombomodulin in human peripheral nerve microvasculature
Authors: Hafer‐Macko Charlene E. , Ivey Frederick M. , Gyure Kymberly A. , Sorkin John D. , Macko Richard F.
Published: October 2002

Thrombomodulin (TM), a vascular endothelial receptor, terminates the actions of thrombin and accelerates activated protein C formation. TM is ubiquitous throughout the systemic microcirculation but is reduced in brain regions predisposed to lacunar infarction. We investigated whether TM is present within human nerve and differentially expressed according to vessel caliber and proximity to the blood–nerve barrier. Vascular endothelial TM was detected on sural nerve biopsies with immunohistochemistry. The proportion of TM‐positive microvessels was expressed relative to total von Willebrand factor (vWF)–positive vessels. Although vWF was detectable in all microvessels, TM expression was absent from the perineurial vessels. TM was detected in 47% (15–80%, 95% confidence level) of larger epineurial arterioles, in 43% (30–61%) of smaller epineurial vessels, and in 30% (19–47%) of endoneurial vessels. These findings demonstrate that TM is present in human nerve microvasculature but is regionally deficient in proximity to the blood–nerve barrier, which may predispose nerve to microvascular ischemia in inflammatory/prothrombotic conditions. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 218–224, 2002
Propriospinal transmission of part of the corticospinal excitation in humans
Authors: Pierrot‐Deseilligny Emmanuel
Published: October 2002

In humans a substantial part of corticospinal excitation to upper limb motoneurons is mediated through cervical premotoneurons located rostral to motoneurons, analogous to the feline system of C3–C4 propriospinal neurons. The indirect (disynaptic) component of the corticospinal command passing through the propriospinal relay may be updated by the extensive convergence at this level of afferent inputs (both excitatory and inhibitory) from the moving limb. Propriospinal neurons are potently inhibited by feedback inhibitory interneurons facilitated from the motor cortex, and this explains why artificial volleys delivered to the pyramidal system by itself have failed to demonstrate this indirect corticospinal projection. The strength of this indirect corticospinal projection may be estimated in routine practice by the amount of suppression elicited by a cutaneous volley on the ongoing electromyogram of extensor carpi radialis, and is increased in patients recovering from hemiplegia and in early Parkinson's disease. © 2002 Wiley Periodicals, Inc. Muscle Nerve 26: 155–172, 2002
Simulation of localization failure with strain‐gradient‐enhanced damage mechanics
Authors: Zhou Weiyuan , Zhao Jidong , Liu Yuangao , Yang Qiang
Published: October 2002

Strain gradient implies an important characteristic in localized damage deformation, which can be observed in the softening state of brittle materials, and strain gradients constitute the basic behaviours of localization failure area of the materials. The most important point in strain gradient is its damaging function including an internal length scale, which can be used to express the scale effects of mechanical responses of brittle rock mass. By extending the strain gradient theory and introducing an intrinsic material length scale into the constitutive law, the authors develop an isotropic damage model as well as a micro‐crack‐based anisotropic damage model for rock‐like materials in this paper. The proposed models were used to simulate the damage localization under uniaxial tension and plain strain compression, respectively. The simulated results well illustrated the potential of these models in dealing with the well‐known mesh‐sensitivity problem in FEM. In the computation, elements with C1 continuity have been implemented to incorporate the proposed models for failure localization. When regular rectangle elements are encountered, the coupling between finite difference method (FDM) and conventional finite element method (FEM) is used to avoid large modification to the existing FEM code, and to obtain relatively higher efficiency and reasonably good accuracy. Application of the anisotropic model to the 3D‐non‐linear FEM analysis of Ertan arch dam has been conducted and the results of its numerical simulation coincide well with those from the failure behaviours obtained by Ertan geophysical model test. In this paper, new applications of gradient theories and models for a feasible approach to simulate localized damage in brittle materials are presented. Copyright © 2002 John Wiley & Sons, Ltd.
Designing a screening experiment for highly reliable products
Authors: Yu Hong‐Fwu , Tseng Sheng‐Tsaing
Published: October 2002

Within a reasonable life‐testing time, how to improve the reliability of highly reliable products is one of the great challenges to today's manufacturers. By using a resolution III experiment together with degradation test, Tseng, Hamada, and Chiao (1995) presented an interesting case study of improving the reliability of fluorescent lamps. However, in conducting such an experiment, they did not address the problem of how to choose the optimal settings of variables, such as sample size, inspection frequency, and termination time for each run, which are influential to the correct identification of significant factors and the experimental cost. Assuming that the product's degradation paths satisfy Wiener processes, this paper proposes a systematic approach to the aforementioned problem. First, an intuitively appealing identification rule is proposed. Next, under the constraints of a minimum probability of correct decision and a maximum probability of incorrect decision of the proposed identification rule, the optimum test plan (including the determinations of inspection frequency, sample size, and termination time for each run) can be obtained by minimizing the total experimental cost. An example is provided to illustrate the proposed method. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 514–526, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10024
Using hybrid metaheuristics for the one‐way and two‐way network design problem
Authors: Drezner Zvi , Salhi Said
Published: October 2002

A network with traffic between nodes is known. The links of the network can be designed either as two‐way links or as one‐way links in either direction. The problem is to find the best configuration of the network which minimizes total travel time for all users. Branch and bound optimal algorithms are practical only for small networks (up to 15 nodes). Effective simulated annealing and genetic algorithms are proposed for the solution of larger problems. Both the simulated annealing and the genetic algorithms propose innovative approaches. These innovative ideas can be used in the implementation of these heuristic algorithms for other problems as well. Additional tabu search iterations are applied on the best results obtained by these two procedures. The special genetic algorithm was found to be the best for solving a set of test problems. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 49: 449–463, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/nav.10026
Distributions of estrogen receptors alpha and beta in sympathetic neurons of female rats: Enriched expression by uterine innervation
Authors: Zoubina Elena V. , Smith Peter G.
Published: October 2002

Estrogen modulates many features of the sympathetic nervous system, including cell numbers and ganglion synapses, and can induce uterine sympathetic nerve degeneration. However, distributions of estrogen receptors α and β within sympathetic neurons have not been described, and their regulation by target tissue or estrogen levels has not been explored. We used immunofluorescence and retrograde tracing to define estrogen receptor expression in sympathetic neurons at large in pre‐ and paravertebral ganglia and in those projecting to the uterine horns. Estrogen receptor α immunoreactivity was present in 29 ± 1%, while estrogen receptor β was expressed by 92 ± 1% of sympathetic neurons at large. The proportions of neurons expressing these receptors were comparable in the superior cervical and thoraco‐lumbar paravertebral ganglia from T11 through L5, and in the suprarenal, celiac, and superior mesenteric prevertebral ganglia. Injections of FluoroGold into the uterine horns resulted in labeled neurons, with peak occurrences in T13, L1, and the suprarenal ganglion. Uterine‐projecting neurons showed small but significantly greater incidence of estrogen receptor β expression relative to the neuronal population at large, whereas the proportion of uterine‐projecting neurons with estrogen receptor α‐immunoreactivity was nearly threefold greater. Numbers of estrogen receptor‐expressing neurons were not altered by acute estrogen administration. We conclude that the vast majority of sympathetic neurons express estrogen receptor β immunoreactive protein, whereas a smaller, presumably overlapping subset expresses the estrogen receptor α. Expression of the latter apparently can be enhanced by target‐mediated mechanisms. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 14–23, 2002
Improved implicit integrators for transient impact problems—geometric admissibility within the conserving framework
Authors: Laursen T. A. , Love G. R.
Published: October 2002

The value of energy and momentum conserving algorithms has been well established for the analysis of highly non‐linear systems, including those characterized by the nonsmooth non‐linearities of an impact event. This work proposes an improved integration scheme for frictionless dynamic contact, seeking to preserve the stability properties of exact energy and momentum conservation without the heretofore unavoidable compromise of violating geometric admissibility as established by the contact constraints. The physically motivated introduction of a discrete contact velocity provides an algorithmic framework that ensures exact conservation locally while remaining independent of the choice of constraint treatment, thus making full conservation equally possible in conjunction with a penalty regularization as with an exact Lagrange multiplier enforcement. The discrete velocity effects are incorporated as a post‐convergence update to the system velocities, and thus have no direct effect on the non‐linear solution of the displacement equilibrium equation. The result is a robust implicit algorithmic treatment of dynamic frictionless impact, appropriate for large deformations and fully conservative for a range of geometric constraints. Copyright © 2001 John Wiley & Sons, Ltd.
Characteristics of waves in a functionally graded cylinder
Authors: Han X. , Liu G. R. , Xi Z. C. , Lam K. Y.
Published: October 2002

An analytical‐numerical method is presented for analysing characteristics of waves in a cylinder composed of functionally graded material (FGM). In this method, the FGM cylinder is divided into a number of annular elements with three‐nodal‐lines in the wall thickness. The elemental material properties are assumed to vary linearly in the thickness direction so as to better model the spatial variation of material properties of FGM. The Hamilton principle is used to develop the dispersion equations for the cylinder, and the frequency and the group velocity are established in terms of the Rayleigh quotient. The method is applied to analyse several FGM cylinders, and its efficiency is demonstrated. Numerical results demonstrate that the ratio of radius to thickness has a stronger influence on the frequency spectra in the circumferential wave than on that in the axial wave, that negative group velocity presents at a range of smaller wave numbers and that the range varies as the wave normal and the ratio of radius to thickness of FGM cylinders. Copyright © 2001 John Wiley & Sons, Ltd.
Use of the tangent derivative boundary integral equations for the efficient computation of stresses and error indicators
Authors: Muci‐Küchler K. H. , Miranda‐Valenzuela J. C. , Soriano‐Soriano S.
Published: October 2002

In this work, a new global reanalysis technique for the efficient computation of stresses and error indicators in two‐dimensional elastostatic problems is presented. In the context of the boundary element method, the global reanalysis technique can be viewed as a post‐processing activity that is carried out once an analysis using Lagrangian elements has been performed. To do the reanalysis, the functional representation for the displacements is changed from Lagrangian to Hermite, introducing the nodal values of the tangential derivatives of those quantities as additional degrees of freedom. Next, assuming that the nodal values of the displacements and the tractions remain practically unchanged from the ones obtained in the analysis using Lagrangian elements, the tangent derivative boundary integral equations are collocated at each functional node in order to determine the additional degrees of freedom that were introduced. Under this scheme, a second system of equations is generated and, once it is solved, the nodal values of the tangential derivatives of the displacements are obtained. This approach gives more accurate results for the stresses at the nodes since it avoids the need to differentiate the shape functions in order to obtain the normal strain in the tangential direction. When compared with the use of Hermite elements, the global reanalysis technique has the attraction that the user does not have to give as input data the additional information required by this type of elements. Another important feature of the proposed approach is that an efficient error indicator for the values of the stresses can also be obtained comparing the values for the stresses obtained through the use of Lagrangian elements and the global reanalysis technique. Copyright © 2001 John Wiley & Sons, Ltd.
Non‐weak/strong solutions in gas dynamics: a C11p‐version STLSFEF in Lagrangian frame of reference using ρ, u, p primitive variables
Authors: Surana K. S. , Van Dyne David G.
Published: October 2002

In this paper, we present computations of the non‐weak solutions of class C11 of transient Navier–Stokes equations for compressible flow in Lagrangian frame of reference using space‐time least squares finite element formulation with primitive variables ρ, u, p. For high speed compressible flows the solutions reported here possess the same orders of continuity as the governing differential equations. The role of diffusion i.e. viscosity (physical or artificial) and thermal conductivity on shock structure is demonstrated. Compression of air in a rigid cylinder by a rigid, massless and frictionless piston is used as a model problem. True time evolutions of class C11 are reported beginning with the first time step until steady shock conditions are achieved. Comparisons with analytical solutions are presented when possible. Copyright © 2001 John Wiley & Sons, Ltd.
A GA‐based technique for layout optimization of truss with stress and displacement constraints
Authors: Azid I. A. , Kwan A. S. K. , Seetharamu K. N.
Published: October 2002

Various developments of increasing complexity involved in layout optimization are discussed. The use of conventional GA in layout optimization is briefly mentioned with emphasis on its limitations and conditions imposed in finding the optimal design. The proposed new technique is applied to the benchmark example of Michell's truss for verification. The approach has also been applied to new examples of bridge truss and crane truss problems in order to demonstrate the generality and robustness for topology optimization. The approach is extended to include dual stress‐displacements constraints since many practical problems involve these two constraints simultaneously. Two‐bar and 10‐bar trusses are solved as examples for layout optimization with both stress and displacement constraints with satisfactory results. The effect of mutation on the final topology is also discussed. The major drawbacks of the ground structure approach are overcome in this proposed new method. The optimal designs obtained demonstrate the ability, robustness and generality of using the proposed new technique in layout optimization problems. Copyright © 2001 John Wiley & Sons, Ltd.
A simplified approach for incorporating thickness stress in the analysis of sheet metal forming using shell elements
Authors: Cho J. W. , Yang D. Y. , Chung W. J.
Published: October 2002

A simplified scheme for considering the thickness stress of shell elements induced by contact is presented which improves the accuracy of sheet metal forming analysis. The yield function formulated on the basis of plane stress conditions is modified to incorporate the effect of transverse normal stress induced by contact forces acting on shell elements and return mapping routine is used to update in‐plane stresses at each time step. The transverse normal stress distributions in the thickness direction are determined using the analytic solution of the cylindrical tube under the internal pressure. As numerical examples, uni‐axial compression, bi‐axial tension and bending tests are treated. The problem of cylindrical cup drawing is also calculated. Each result is compared with the results obtained by the analysis using ABAQUS continuum elements. Copyright © 2002 John Wiley & Sons, Ltd.
A p‐version finite element approach for two‐ and three‐dimensional problems of the J2 flow theory with non‐linear isotropic hardening
Authors: Düster A. , Rank E.
Published: October 2002

In this paper an implementation of a two‐ and three‐dimensional p‐version approach to the J2 flow theory with non‐linear isotropic hardening for small displacements and small strains is presented. Based on higher‐order quadrilateral and hexahedral element formulations, a Newton–Raphson iteration scheme combined with a radial return algorithm is applied to find approximate solutions for the underlying physically non‐linear model problem. Curved boundaries are taken care of with the blending function method, allowing an accurate representation of geometry with only a few p‐elements. Numerical examples demonstrate, that the p‐version supplies efficient and accurate approximations to this class of physically non‐linear problems. Copyright © 2001 John Wiley & Sons, Ltd.
Studies of multi‐start clustering for global optimization
Authors: Tu W. , Mayne R. W.
Published: October 2002

Global/multi‐modal optimization problems arise in many engineering applications. Owing to the existence of multiple minima, it is a challenge to solve the multi‐modal optimization problem and to identify the global minimum especially if efficiency is a concern. In this paper, variants of the multi‐start with clustering strategy are developed and studied for identifying multiple local minima in nonlinear global optimization problems. The study considers the sampling procedure, the use of Hessian information in forming clusters, the technique for cluster analysis and the local search procedure. Variations of multi‐start with clustering are applied to 15 multi‐modal problems. A comparative study focuses on the overall search effectiveness in terms of the number of local searches performed, local minima found and required function evaluations. The performance of these multi‐start clustering algorithms ranges from very efficient to very robust. Copyright © 2002 John Wiley & Sons, Ltd.
A comprehensive catastrophe theory for non‐linear buckling of simple systems exhibiting fold and cusp catastrophes
Authors: Lignos X. A. , Parke G. A. R. , Harding J. E. , Kounadis A. N.
Published: October 2002

Non‐linear static buckling of simple systems associated with typical discrete critical points is comprehensively presented using elementary Catastrophe Theory. Attention is focused on the Fold and Cusp Catastrophe, all local properties of which are assessed in detail. Hence, in dealing with stability problems of potential systems there is no need to seek any of these properties since all of these are known a priori. Then, one has only to classify, after reduction, the total potential energy of a system into one of the universal unfoldings of the above types of catastrophe. Two illustrative numerical examples show the methodology of the proposed technique. Copyright © 2002 John Wiley & Sons, Ltd.
On boundary conditions of the characteristic based split (CBS) algorithm for fluid dynamics
Authors: Nithiarasu P.
Published: October 2002

This paper discusses alternative procedures which can be used in the application of boundary conditions for the CBS algorithm. Attention is focused on the problem of application of prescribed velocity and traction conditions. The paper is illustrated with some incompressible flow problems. Although previously logical and correct boundary condition specifications were introduced, the procedures outlined in this paper simplify calculations and generally make it more accurate. Copyright © 2002 John Wiley & Sons, Ltd.
Stress intensity factors for three‐dimensional surface cracks using enriched finite elements
Authors: Ayhan A. O. , Nied H. F.
Published: October 2002

The analysis of three‐dimensional crack problems using enriched crack tip elements is examined in this paper. It is demonstrated that the enriched finite element approach is a very effective technique for obtaining stress intensity factors for general three‐dimensional crack problems. The influence of compatibility, integration, element shape function order, and mesh refinement on solution convergence is investigated to ascertain the accuracy of the numerical results. It is shown that integration order has the greatest impact on solution accuracy. Sample results are presented for semi‐circular surface cracks and compared with previously obtained solutions available in the literature. Good agreement is obtained between the different numerical solutions, except in the small zone near the free surface where previously published results have often neglected the change in the stress singularity at the free surface. The enriched crack tip element appears to be particularly effective in this region, since boundary conditions can be easily imposed on the stress intensity factors to accurately represent the correct free surface condition. Copyright © 2002 John Wiley & Sons, Ltd.
An augmented spatial digital tree algorithm for contact detection in computational mechanics
Authors: Feng Y. T. , Owen D. R. J.
Published: October 2002

Based on the understanding of existing spatial digital tree‐based contact detection approaches, and the alternating digital tree (ADT) algorithm in particular, a more efficient algorithm, termed the augmented spatial digital tree (ASDT) algorithm, is proposed in the present work. The ASDT algorithm adopts a different point representation scheme that uses only the lower corner vertex to represent a (hyper‐)rectangle, with the upper corner vertex serving as the augmented information. Consequently, the ASDT algorithm can keep the working space the same as the original n‐dimensional space and, in general, a much better balanced tree can be expected. This, together with the introduction of an additional bounding subregion for the rectangles associated with each tree node, makes it possible to significantly reduce the number of node visits in the region search, although each node visit may be slightly more expensive. Three examples arising in computational mechanics are presented to provide an assessment of the performance of the ASDT. The numerical results indicate that the ASDT is, at least, over 3.9 times faster than the ADT. Copyright © 2002 John Wiley & Sons, Ltd.
The effect of zeolite on the curing of epoxy resin by polyaniline: a kinetic study
Authors: Sreedhar B. , Palaniappan S. , Narayanan S.
Published: October 2002

Polyaniline sulfate‐zeolite composite was prepared by emulsion polymerization. Epoxy resin was cured using polyaniline‐sulfate salt and various amounts of polyaniline sulfate‐zeolite composite. The kinetics of the cure reaction for an epoxy resin based on the diglycidyl ether of bisphenol A (DGEBA) with polyaniline‐sulfate and polyaniline sulfate‐zeolite composite have been studied using differential scanning calorimetry (DSC) under isothermal and dynamic conditions. Isothermal kinetics analysis was performed using the phenomenological model of Kamal. Dynamic kinetic analysis was performed using Kissinger's method. Copyright © 2002 John Wiley & Sons, Ltd.
p27/kip1 expression in normal epithelium, benign and neoplastic breast lesions
Authors: De Paola Franca , Maria Vecci Anna , Maria Granato Anna , Liverani Marilena , Monti Franco , Maria Innoceta Anna , Gianni Lorenzo , Saragoni Luca , Ricci Monica , Falcini Fabio , Amadori Dino , Volpi Annalisa
Published: October 2002

The development of cancer in the breast and in other sites is a complex process requiring a number of different genetic and epigenetic alterations. The accumulation of the genetic changes is thought to underlie the progression from precancerous lesions to carcinomas. The expression of p27/kip1 protein, a cyclin‐dependent kinase inhibitor, was investigated by immunohistochemistry in normal epithelial specimens, benign alterations, and malignant lesions of the breast. The number of p27/kip1‐positive cells ranged from none to more than 98% in the overall series. Wide ranges of p27/kip1‐positive cells were consistently observed within each histological category, but the median value progressively decreased in typical hyperplasia and fibroadenoma, with an even more marked reduction in malignant lesions, compared with normal epithelium. Moreover, the percentage of cells expressing p27/kip1 in tumours was about three times lower in invasive than in in situ lesions and was inversely related to tumour size, but not to lymph node involvement. In conclusion, the degree to which p27 expression is altered in typical hyperplastic lesions and fibroadenomas indicates that the deregulation of p27 may occur very early on during breast cell transformation, but the usefulness of its determination to categorize subgroups of lesions at different risk of evolution remains somewhat doubtful. Copyright © 2001 John Wiley & Sons, Ltd.
Abnormal immunoreactivity of the E‐cadherin/catenin (α‐, β‐, and γ‐) complex in premalignant and malignant non‐melanocytic skin tumours
Authors: Papadavid Evangelia , Pignatelli Massimo , Zakynthinos Spyridon , Krausz Thomas , Chu Anthony C.
Published: October 2002

E‐cadherin/catenin (α‐, β‐, and γ‐) complex plays a critical role in the control of epithelial differentiation. The aim of this study was to examine the immunoreactivity of E‐cadherin and α‐, β‐, and γ‐catenins in premalignant and malignant non‐melanocytic skin tumours (NMST) and to correlate their expression with the grade of tumour differentiation, as assessed by the established histopathological criteria and by the Ki‐67 index. Benign NMSTs were also studied. To investigate any possible influence of immunosuppression in the expression of E‐cadherin and catenins, the study compared tumours obtained from renal transplant recipients (RTRs) and immunocompetent patients. Immunoperoxidase staining of E‐cadherin and α‐, β‐, and γ‐catenins was performed in 42 squamous cell carcinomas (SCCs) (26 from RTRs and 16 from non‐RTRs), 30 lesions of Bowen's disease (11 from RTRs and 19 from non‐RTRs), 11 atypical squamoproliferative lesions from RTRs, 19 actinic keratoses (9 from RTRs and 10 from non‐RTRs), and 20 viral warts from RTRs. The findings of this study were as follows. Firstly, the probability of abnormal expression of E‐cadherin and α‐, β‐, and γ‐catenins increased from benign to premalignant and malignant NMSTs (p<0.001 for all). Secondly, there was agreement in abnormal expression between most of the molecules measured in malignant and premalignant NMSTs (p<0.05). Thirdly, in SCC, abnormal expression of E‐cadherin and catenins was more frequent in lesions with a high (>40%) Ki‐67 index than in those with a low Ki‐67 index (<40%) (p=0.003). However, only the abnormal expression of γ‐catenin increased with the grade of SCC differentiation (p=0.008). Fourthly, abnormal expression of γ‐catenin predicted a high proliferation index (Ki‐67 index 40%) in NMSTs (p<0.01, OR=6.19). Finally, there was no difference in the abnormal expression of E‐cadherin and catenins between NMSTs from immunosuppressed and immunocompetent patients. Thus, abnormal expression of the E‐cadherin/catenin complex was quite common in SCC and Bowen's disease and also in a proportion of intraepithelial dysplastic lesions, such as atypical squamoproliferative lesions and actinic keratosis, suggesting that these changes may be early indicators of the neoplastic process. Abnormal expression of γ‐catenin was the sole predictor of high proliferation in NMST and was also correlated with the tumour grade, suggesting a possible important role for γ‐catenin in tumourigenesis. Copyright © 2001 John Wiley & Sons, Ltd.
Glomerulo‐tubular junction stenosis as a factor contributing to glomerular obsolescence in IgA nephropathy
Authors: Sato Mitsuhiro , Hotta Osamu , Taguma Yoshio
Published: October 2002

Periglomerular fibrosis (PF) is an interstitial injury observed in various renal diseases. It is speculated that this lesion, by occluding the glomerulo‐tubular junction (GTJ) and causing atubular glomeruli, may result functionally in a reduction of the glomerular filtration rate (GFR) and may be a factor contributing to the progression of renal disease. In the present study, 340 renal biopsy specimens were analysed to determine whether or not there was nephron injury derived from such a mechanism, as well as direct glomerular injury, in IgA nephropathy (IgAN). The patients were divided into five groups according to the degree of glomerular sclerosis. The average age was lower in groups with milder sclerosis and serum creatinine (Cr) was elevated in groups with more severe sclerosis. Because the GTJ was assumed to disappear when an atubular glomerulus was formed, the ratio of the number of glomeruli with discernible GTJ to the total number of glomeruli was evaluated. As glomerular sclerosis progressed, discernible GTJ reduced significantly (p<0.001) and the degree of PF increased significantly (p<0.05). By serial section study in cases with pronounced PF, transitions between the stages of stenosis of the GTJ and atubular glomeruli were observed. It is speculated that the occlusion of the GTJ eventually hyalinizes the glomerulus; in such cases, glomerular obsolescence of the collapse type might be formed. On the other hand, obsolescence of the mesangial proliferative type might be formed in the hyalinization derived from direct glomerular injury. In this context, glomerular obsolescence of the collapse type was observed more frequently and was accompanied by more increased PF than obsolescence of the mesangial proliferative type (p<0.001). These results suggest that in addition to direct glomerular injury, nephron injury derived from interstitial damage of this type plays an important contributory role in the progression of IgAN. Copyright © 2002 John Wiley & Sons, Ltd.
Expression of 4C8 antigen, a novel transendothelial migration‐associated molecule on activated T lymphocytes, in inflammatory bowel disease
Authors: Oshitani Nobuhide , Hato Fumihiko , Kitagawa Seiichi , Masuyama Junichi , Higuchi Kazuhide , Matsumoto Takayuki , Arakawa Tetsuo
Published: October 2002

Recruitment of peripheral leukocytes to intestine is an essential process for intestinal inflammation. This study examined the localization of a novel molecule, 4C8 antigen, in inflammatory bowel disease; this molecule is involved in the transendothelial migration of T lymphocytes. Surgical specimens of human intestine were obtained from nine patients with ulcerative colitis, 13 with Crohn's disease, and eight controls. Immunohistological staining was performed using antibodies against 4C8 antigen, and CD3, CD4, CD8, CD20, CD68, CD45RA, CD45RO, CD11a, and CD62 (E‐ and P‐selectin) by the peroxidase method. Immunological double staining was subsequently performed for the same specimens stained with anti‐4C8 antibody using the alkaline phosphatase method. In normal controls, 4C8‐positive cells were mainly found in lamina propria. 4C8‐positive cells were increased in lamina propria and submucosa of specimens with Crohn's disease. Accumulation of 4C8‐positive cells surrounding CD62‐positive vessels was found in the submucosa of specimens with inflammatory bowel disease, but not in controls. Immunohistological double staining revealed that the major subsets of 4C8‐positive cells were positive for CD3, CD4, CD45RO, and CD11a. 4C8‐positive cells in human intestine belong to the subset of helper/inducer memory T cells newly recruited from the peripheral pool. Inhibition of the 4C8‐ligand system could have potentially uses in the treatment of inflammatory bowel disease. Copyright © 2002 John Wiley & Sons, Ltd.
An increase in cost‐effectiveness of first trimester maternal screening programmes for fetal chromosome anomalies is obtained by contingent testing
Authors: Christiansen Michael , Olesen Larsen Severin
Published: October 2002

We assessed the discriminatory efficiency and cost‐effectiveness of a novel way of organising first trimester screening for Down syndrome (DS), contingent testing, where a serological test (PAPP‐A and β‐hCG: the double test) is made in early first trimester and followed by nuchal translucency testing (NT) only in women with an intermediate risk, e.g. <1:65 and >1:1000, and not in all women as in normal first trimester screening (NFTS). Using Monte Carlo simulation contingent testing had a detection rate (DR) of 78.9% and a false‐positive rate (FPR) of 4.0% for DS with 19.4% of women offered NT testing. The DR of NFTS was 85.5% and the FPR 4.4%. The decrease in NT screening was associated with an increase from 23% to 29% in the proportion of DS cases born. The cost of the contingent testing programme was £53 000 per DS case not born and £91 000 in NFTS. The number of aborted fetuses per DS case were 0.35 and 0.36, respectively. Thus, contingent testing is an organisation of first trimester screening where costs can be reduced with a marginal decrease in performance. Contingent testing is attractive in areas where NT screening is the bottleneck preventing the introduction of first trimester screening. Copyright © 2002 John Wiley & Sons, Ltd.
Prenatal diagnosis of female monozygotic twins discordant for Turner syndrome: implications for prenatal genetic counselling
Authors: Gilbert B. , Yardin C. , Briault S. , Belin V. , Lienhardt A. , Aubard Y. , Battin J. , Servaud M. , Philippe H. J. , Lacombe D.
Published: October 2002

We describe a set of monozygotic (MZ) female twins, one of whom presented with a typical Turner syndrome (TS) phenotype and the other a normal female phenotype. Prenatal fetal ultrasonographic examination showed a monochorial diamniotic pregnancy with a hygroma colli and growth delay in Twin A and no anomalies in Twin B. Karyotypic analysis performed on fetal blood samples demonstrated a 46,XX/45,X (23/2) mosaicism in Twin A and a normal 46,XX chromosome constitution in Twin B. At birth, Twin A presented with a typical TS and Twin B had a normal female phenotype. Postnatal cytogenetic investigation of blood lymphocytes showed the same 46,XX/45,X mosaicism in both twins: 46,XX/45,X (40/7) in Twin A and 46,XX/45,X (40/5) in Twin B. Further investigations at the age of 10 months showed in Twin A a 46,XX/45,X (98/2) mosaicism in lymphocytes and 100% of 45,X (50 analysed cells) in fibroblasts, and in Twin B a normal 46,XX (100 analysed cells) chromosome constitution in lymphocytes but a mild 46,XX/45,X (78/2) mosaicism in fibroblasts. Monozygosity was confirmed by molecular analysis. To our knowledge, this is the first report of prenatal diagnosis of MZ female twins discordant for TS. Review of reported sets of MZ female twins (eight cases) or triplets (one case) discordant for TS shows, as in the present case, that the phenotype correlates better with the chromosomal distribution of mosaicism in fibroblasts than in lymphocytes. In the blood of MZ twins chimerism may modify the initial allocation of the mosaicism. These results suggest that, in cases of prenatal diagnosis of MZ female twins discordant for TS, the phenotype of each twin would be better predicted from karyotype analysis of cells from amniotic fluid than from fetal blood. Copyright © 2002 John Wiley & Sons, Ltd.
Study on polypropylene/natural rubber blend with polystyrene‐modified natural rubber as compatibilizer
Authors: Hashim Azanam S , Ong S K
Published: October 2002

Polystyrene‐modified natural rubber (SNR) was prepared in the laboratory and subsequently used as compatibilizer in polypropylene/natural rubber (PP/NR) blends. The effect of SNR (at 5%, 10%, 15% and 20% by volume) in PP/NR (70/30) blend was studied by maintaining the rubber volume while PP volume was replaced by SNR accordingly. The sequence of mixing was found to affect the blend morphology and tensile properties. The effect of curatives on the tensile properties of the blends was also investigated. The addition of curatives into the rubbers in PP/NR/SNR improved the tensile properties significantly compared with the PP/NR reference blend. For a semi‐efficient curative system, SNR loading at 10% gave the best overall tensile properties, while for an efficient curative system, 5% SNR loading resulted in improvements in tensile strength and stiffness of over 20% and 40%, respectively, compared with the reference.

© 2002 Society of Chemical Industry
Acidity and basicity of primary N‐phenylnitramines: catalytic effect of protons on the nitramine rearrangement
Authors: Daszkiewicz Zdzisław , Spaleniak Grzegorz , Kyzioł Janusz B.
Published: October 2002

Para‐substituted N‐phenylnitramines were prepared either by oxidation of diazonium salts or by nitration under alkaline or acidic conditions. Isotopic [15N‐NO2] labelling indicated that the bands characteristic of the N‐nitro group appear in the 1318–1323 and 1585–1607 cm−1 regions. In the nitrogen NMR spectra, the nitramino group gives two resonances at −193 ± 3 (NH) and −32 ± 3 ppm (NO2). The chemical shifts in proton and carbon NMR spectra are predictable, based on increments and the additivity rule. The spectral data indicate the lack of conjugation between the nitramino group and another substituent bound to the ring. It seems to contradict the well‐known fact that substituents strongly (ρ = 4) influence the rate of nitramine rearrangement. The acidities of primary N‐phenylnitramines (3.77 < pKA < 5.62) are similar to those of benzoic acids and weakly dependent (ρ = 1) on the electronic character of a substituent. Based on the analogy with benzoic acids, it has been calculated that basicities of nitramines (pKB ≈ 21) are extremely low. Consequently, addition of protons to an intact nitramine molecule, as the preliminary step of the rearrangement, seems to be improbable. Migration of the N‐nitro group precedes protonation; the latter process facilitates transformation of intermediates into stable final products. Copyright © 2001 John Wiley & Sons, Ltd.
Anisotropic molecular movements in organic crystals by mechanical stress
Authors: Kaupp Gerd , Schmeyers Jens , Hangen Ude D.
Published: October 2002

Nanoindents and nanoscratching on organic crystals with their anisotropic molecular packing explore far‐reaching molecular movements or abrasion of material by the application of mechanical stress. Only intermolecular hydrogen bonds and van der Waals ‘bonds’ are broken in these experiments. Thiohydantoin (1) is a particularly suitable model owing to its well‐defined layered crystal packing and its cleavability at the (10–2)‐planes. Indents with a cube corner indenter on the natural (110)‐face give piling‐up of material by molecular movements only to one side by following the direction of the slopes of the molecular monolayers. Four orthogonal nanoscratches along and across the long crystal edge (each back and forth) on (110) give four different very distinct results: (1) molecular movements to both sides and in front with symmetric piling‐up, (2) abrasion of material, (3) molecular movements to the right and (4) molecular movements to the left. The influence of the single molecular layers that stand 66° steep is clearly expressed by these results. No molecular movement but abrasion of material occurs upon nanoscratching on the (10–2) cleavage plane of 1, now with the molecular monolayers flat. These anisotropic molecular responses to mechanical stress are detected by atomic force microscopy. They may be of use in nanotechnology, but cannot be predicted by the more common collective mechanical properties such as hardness or Young's elasticity modulus, quantities that do not at all relate to the extreme anisotropies that are reported here for the first time. Copyright © 2002 John Wiley & Sons, Ltd.
Looking for a contribution of the non‐equilibrium solvent polarization to the activation barrier of the SN2 reaction
Authors: Jaworski Jan S.
Published: October 2002

The solvent effect on the activation free energy of the Finkelstein reaction between methyl iodide and Cl− ions was analysed in terms of the recent Marcus theory unifying the SN2 and the electron transfer reactions. The homolytic bond dissociation energy and the related resonance energy of interaction of the states seem to be almost solvent independent. The sum of the work term wr and the solvent reorganization energy λ0/4 depends strongly on the solvent acidity parameter, e.g. ETN, describing the solvation/desolvation of anions. However, after removing the contribution of the specific solvation the linear increase of the remaining part of λ0/4 with the Pekar factor, describing the non‐equilibrium solvent polarization, was observed for six aprotic solvents. Copyright © 2002 John Wiley & Sons, Ltd.
Kinetic and mechanistic studies on the inhibition of free radical‐initiated polymerization of styrene by β‐carotene and α‐tocopherol
Authors: Li Zhaolong , Cui Jian , Hong Xiaoyin , Liu Youcheng , Liu Zhongli
Published: October 2002

The inhibition of free radical‐initiated polymerization of styrene by β‐carotene (βC) and α‐tocopherol (TOH) was studied by dilatometry. The polymerization was initiated by 2,2′‐azobis(isobutyronitrile) at 50 °C in chlorobenzene and inhibited by βC and/or TOH. It was found that βC and TOH could efficiently inhibit the polymerization, either used individually or in combination, and a significant synergistic effect was observed when they were used in combination. It is proposed that retinal, which is the principal oxidation product of βC, may be involved in the synergistic inhibition reaction of βC and TOH. Copyright © 2002 John Wiley & Sons, Ltd.
Acid‐catalyzed hydrolysis of bridged bi‐ and tricyclic compounds. XXXIX—Kinetics and mechanisms of the hydration reactions of 1‐ and 3‐acetylnortricyclanes
Authors: Lajunen Martti , Salmi Jani , Limnell Taru
Published: October 2002

The disappearance of 1‐ and 3‐acetylnortricyclanes (1‐Ac and 2‐Ac) in aqueous perchloric acid was followed by capillary gas chromatography at different temperatures and acid concentrations. 1‐Ac is much less reactive than 2‐Ac. The activation parameters, solvent deuterium isotope effects and parameters of excess acidity equations were measured and the products studied. 1‐Acetylnortricyclane is hydrated according to the A‐2 mechanism, i.e. the carbonyl oxygen is protonated in the fast pre‐equilibrium and one water molecule attacks at the rate‐limiting stage the partially open cyclopropane ring, producing 6‐acetyl‐2‐norborneols. 3‐Acetylnortricyclane is hydrated according to the AdE2 mechanism, i.e. the cyclopropane ring is slowly protonated and opened, with subsequent fast attack of water producing 3‐, 5‐ and 7‐acetyl‐2‐norborneols. Copyright © 2002 John Wiley & Sons, Ltd.
Controlled ring‐opening polymerization of cyclic carbonates and lactones by an activated monomer mechanism
Authors: Endo Takeshi , Shibasaki Yuji , Sanda Fumio
Published: October 2002

This article reviews recent topics in the controlled synthesis of polycarbonates and polylactones with small polydispersity indices by activated monomer cationic ring‐opening polymerizations, especially with new initiator systems, such as alcohol/protonic acid and boron alkoxide/protonic acid. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2190–2198, 2002
Single‐electron and two‐electron transfer in the anionic polymerization of vinyl monomers and the ring‐opening polymerization of lactones*
Authors: Jedliński Zbigniew
Published: October 2002

Single‐electron‐transfer (SET) and two‐electron‐transfer reactions and their mechanisms were examined in the anionic polymerization of vinyl monomers and in the ring‐opening polymerization of lactones. SET resulted in the formation of radical anions or enolates at the initiation step of styrene or lactone polymerization with naphthalene sodium as a catalyst. However, alkali‐metal supramolecular complexes such as M+crown–M− (M = Na or K) were able to transfer two electrons to both these monomers to form carbanions as reactive intermediates. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2158–2165, 2002