bluuebunny/crossref_metadata_2025 huggingface dataset:
Three-Dimensional Vortex Method for Gas-Particle Two-Phase Compound Round Jet
Authors: Uchiyama Tomomi , Fukase Akihito
Published: March 2005

This paper proposes a three-dimensional vortex method for a gas-particle two-phase compound round jet. The method can take account of the interaction between the two phases by calculating the motion of particles and the behavior of gas vortex elements through the Lagrangian approach. In order to discuss the validity of the method, an air jet, loaded with small glass particles, issuing from a round nozzle into the co-flowing air stream is simulated. The simulation demonstrates that the air turbulence modulations due to the particles, such as the relaxation of velocity decay, the decrement of momentum diffusion in the radial direction at the fully developed region, and the reduction of turbulent intensity and Reynolds shear stress, are successfully captured by the method.
Validation of a 3D RANS Solver With a State Equation of Thermally Perfect and Calorically Imperfect Gas on a Multi-Stage Low-Pressure Steam Turbine Flow
Authors: Lampart Piotr , Rusanov Andrey , Yershov Sergey , Marcinkowski Stanislaw , Gardzilewicz Andrzej
Published: March 2005

A state equation of thermally perfect and calorically imperfect gas is implemented in a 3D RANS solver for turbomachinery flow applications. The specific heats are assumed as linear functions of temperature. The model is validated on a five-stage low-pressure steam turbine. The computational results exhibit the process of expansion in the turbine. The computed and measured distributions of flow parameters in axial gaps downstream of subsequent turbine stages are found to agree reasonably well. It is also shown that the obtained numerical solution gives considerable improvement over the solution based on the thermally and calorically perfect gas model.
Steady-State Residual Vibrations in High-Speed, Dwell-Type, Rotating Disk Cam-Follower Systems
Authors: Felszeghy Stephen F.
Published: March 2005

Followers driven by high-speed, dwell-type, rotating disk cams can exhibit undesirable residual vibrations during dwell. These vibrations have been studied with linear models mostly using results from transient vibration analysis, assuming quiescent initial conditions. Here, the residual vibrations are studied with closed-form solutions to the steady-state vibrations obtained with a circular convolution integral. The steady-state vibrations, which can extend over the entire cam cycle, are periodic and continuous. It is shown that significant differences exist between the residual vibration results obtained from steady-state analysis and those obtained from transient analysis. The undamped steady-state vibrations exhibit resonances. Away from the resonance conditions, the steady-state residual vibration amplitudes are consistently smaller than those predicted by transient analysis. The results from the two approaches agree quantitatively only for relatively stiff and damped follower systems.
An Efficient Technique for Design of Hydraulic Engine Mount via Design Variable-Embedded Damping Modeling
Authors: Lee Jun-Hwa , Kim Kwang-Joon
Published: March 2005

For an efficient design of hydraulic mounts, it is most important to have a good mathematical model available, which must be simple yet capable of representing dynamic characteristics of the hydraulic mounts accurately. Under high amplitude excitations in the low-frequency range, the hydraulic mounts show strongly frequency-dependent stiffness and damping characteristics, which are related with so-called inertia track dynamics. Since nonlinear damping models based on fluid mechanics are typically used to predict the dynamic characteristics of the hydraulic mounts, relations between various design variables, such as geometry of the inertia track, and resultant stiffness and damping characteristics are understood only by tedious numerical computations. In this paper, the use of an equivalent viscous damping model—derived from a nonlinear model and represented in terms of design variables in an explicit manner—is proposed and, based on the equivalent linear model, are presented simple as well as very useful formulas for an efficient design of the hydraulic mounts.
A Frequency Domain Technique for Characterizing Nonlinearities in a Tire-Vehicle Suspension System
Authors: McGee C. Gavin , Haroon Muhammad , Adams Douglas E. , Luk Yiu Wah
Published: March 2005

Characterization of tire and suspension system nonlinearities in measured data is the first step in developing input-output quarter car models; however, system identification procedures, which require a priori knowledge of all nonlinearities within a system, often receive more attention in the research community. Furthermore, relatively few investigations have focused on nonlinear characterization and identification in the absence of input measurements. A new method for characterizing nonlinearities, in the absence of an input measurement, using transmissibility functions and ordinary coherence functions between response measurement degrees of freedom is discussed here. It is shown that the nonlinear nature of a vehicle system provides information about the nominal linear system when the input is unknown. Nonlinear frequency permutations, which create drops in the ordinary coherence function, serve to characterize the associated nonlinearities. In the absence of input measurements, coherence functions of the response transmissibility between the vehicle spindle and body allow the nonlinearities in the suspension system, but not the tires, to be characterized. Simulation results are discussed and the method is applied to experimental laboratory and operating data to validate the approach.
Dynamic Response Optimization of Piezoelectrically Excited Thin Resonant Beams
Authors: Basak Sudipta , Raman Arvind , Garimella Suresh V.
Published: March 2005

Piezoelectrically excited, resonant, elastic beams find wide use as piezoelectric fans, optical choppers, MEMS sensors, and piezoelectric motors. The devices consist of either one piezoelectric ceramic patch (piezopatch) bonded on one side (asymmetric configuration), or of two oppositely poled patches placed symmetrically on either side of a thin, flexible elastic beam (symmetric configuration). Field equations of the coupled structure governing the coupled longitudinal and bending motions of the resonator are derived using linear constitutive equations, slender beam approximations, and Hamilton’s principle. Analytical solutions are found to the coupled eigenvalue problem. Eigenvalues and eigenfunctions for the short-circuited and open-circuited configurations are predicted analytically and are found to be in excellent agreement with results from three-dimensional finite element simulations. Electromechanical coupling factors (EMCF) are computed using the analytical and finite element model and optimal resonator geometries are identified for maximal EMCF. The EMCF predictions are also compared with experiments for an asymmetrically configured resonator. The analytical solution provides a convenient tool for the optimal design of such devices.
Nonlinear Vibration of Sheet Metal Plates Under Interacting Parametric and External Excitation During Manufacturing
Authors: Kim Chung Hwan , Lee Chong-Won , Perkins N. C.
Published: March 2005

This study is motivated by the vibrations that plague coating processes used in the manufacturing of coated sheet metal. These vibrations arise from time-dependent tension fluctuations within the sheet metal plate as well as from the eccentricity of the rollers used to transport the plate. The time-dependent tension is observed to be rather broad-band and creates multi-frequency parametric excitation. By contrast, the roller eccentricity is largely single-frequency (synchronized with the roller speed) and creates single-frequency external excitation. The plate and excitation sources are studied herein using a single-degree-of-freedom model with a cubic nonlinearity, subject to combined parametric and external excitation. In our study, we investigate the resonances that arise from the synergistic effects of multi-frequency parametric excitation and single-frequency external excitation. For the simpler case of single-frequency parametric excitation, we observe both sum and difference combination resonances in addition to principal parametric resonance. For the case of multi-frequency parametric excitation, we observe a frequency shift for the parametric resonance that derives from the cubic nonlinearity and external excitation. Moreover, the phase relationships of the external and each parametric excitation source have a significant effect on the resulting response amplitude. We use these analyses to explain the resonance mechanisms observed in experiments conducted on an example sheet metal coating process.
DORSAL PENTAGONAL ISLAND FLAP: A TECHNIQUE OF WEB RECONSTRUCTION FOR SYNDACTYLY THAT FACILITATES DIRECT CLOSURE
Authors: Teoh L. C. , Lee J. Y. L.
Published: March 2005

Though many techniques have been described for the correction of syndactyly, current methods result in skin deficiency that requires skin grafting, especially at the finger bases. We discuss the technical aspects and document our experience with the dorsal pentagonal metacarpal island flap for reconstruction of the web commissure in a series of 12 patients (22 webs) with syndactyly of varying complexity.

In appropriately selected cases, this technique can improve reconstruction of the web commissure, facilitating direct closure, minimising the need for skin grafts and offers the potential for continued growth. This reduces operative time significantly and simplifies post-operative wound care. In this series, all our cases healed primarily in two to three weeks with minimal donor site morbidity. There were no post-operative complications, although the prominent dorsal scar remains a concern. At an average follow-up of 33.7 months, no cases of contracture or web creep after correction were noted.
Developmental Origins of the Metabolic Syndrome: Prediction, Plasticity, and Programming
Authors: Mcmillen I. Caroline , Robinson Jeffrey S.
Published: March 2005

The “fetal” or “early” origins of adult disease hypothesis was originally put forward by David Barker and colleagues and stated that environmental factors, particularly nutrition, act in early life to program the risks for adverse health outcomes in adult life. This hypothesis has been supported by a worldwide series of epidemiological studies that have provided evidence for the association between the perturbation of the early nutritional environment and the major risk factors (hypertension, insulin resistance, and obesity) for cardiovascular disease, diabetes, and the metabolic syndrome in adult life. It is also clear from experimental studies that a range of molecular, cellular, metabolic, neuroendocrine, and physiological adaptations to changes in the early nutritional environment result in a permanent alteration of the developmental pattern of cellular proliferation and differentiation in key tissue and organ systems that result in pathological consequences in adult life. This review focuses on those experimental studies that have investigated the critical windows during which perturbations of the intrauterine environment have major effects, the nature of the epigenetic, structural, and functional adaptive responses which result in a permanent programming of cardiovascular and metabolic function, and the role of the interaction between the pre- and postnatal environment in determining final health outcomes.
Embryonic Stem Cells: Prospects for Developmental Biology and Cell Therapy
Authors: Wobus Anna M. , Boheler Kenneth R.
Published: March 2005

Stem cells represent natural units of embryonic development and tissue regeneration. Embryonic stem (ES) cells, in particular, possess a nearly unlimited self-renewal capacity and developmental potential to differentiate into virtually any cell type of an organism. Mouse ES cells, which are established as permanent cell lines from early embryos, can be regarded as a versatile biological system that has led to major advances in cell and developmental biology. Human ES cell lines, which have recently been derived, may additionally serve as an unlimited source of cells for regenerative medicine. Before therapeutic applications can be realized, important problems must be resolved. Ethical issues surround the derivation of human ES cells from in vitro fertilized blastocysts. Current techniques for directed differentiation into somatic cell populations remain inefficient and yield heterogeneous cell populations. Transplanted ES cell progeny may not function normally in organs, might retain tumorigenic potential, and could be rejected immunologically. The number of human ES cell lines available for research may also be insufficient to adequately determine their therapeutic potential. Recent molecular and cellular advances with mouse ES cells, however, portend the successful use of these cells in therapeutics. This review therefore focuses both on mouse and human ES cells with respect to in vitro propagation and differentiation as well as their use in basic cell and developmental biology and toxicology and presents prospects for human ES cells in tissue regeneration and transplantation.
Single Nucleotide Polymorphisms Associated with Hepatocellular Carcinoma in Patients with Chronic Hepatitis B Virus Infection
Authors: Kim Yoon Jun , Lee Hyo-Suk
Published: March 2005

It is estimated that there are millions of single nucleotide polymorphisms (SNPs) within human genome and there are likely to explain much of the genetic diversity of individuals. Hepatocellular carcinoma (HCC) is etiologically associated with hepatitis B virus (HBV) in 80% of cases, and is the dominant cause of death among HBV carriers. Among patients with chronic HBV infection, family history is a known risk factor for the development of HCC; therefore, genetic factors are likely to modify the risk of HCC. However, the genetic factors that determine progression to HCC remain mostly to be investigated. In this review, we discussed that the natural history of HBV infection and host genetic factors related to HCC, study design and target gene selection for the detection of SNPs related to the occurrence of HCC. Also, we reviewed that several SNPs or haplotypes, which were reportedly associated with increased or reduced risk of HCC occurrence in patients with chronic HBV infection. Screening of these polymorphisms might be useful in clinical practice to stratify the lower or higher risk group for HCC and might modify the design of HCC surveillance programs in patients with chronic HBV infection, if further genetic susceptibilities are identified.
Brucellosis: Haemorrhagic Pleural Effusion
Authors: Al-Anazi Awadh R. , Aziz Shahid , Fouda Mona A.
Published: March 2005

Objectives: To describe haemorrhagic pleural effusion as a rare complication of brucellosis that finally needed lung decortication. Clinical Presentation and Intervention: A 37-year-old female presented with a 1-week history of fever, dry cough and pleuritic chest pain. Physical examination showed signs of right pleural effusion and hepatosplenomegaly. Complete blood count showed pancytopenia, white blood cells 2.9/mm3, haemoglobin 10 g/dl, platelets 131/mm3. Chest X-ray confirmed a moderate right pleural effusion, that was found to be exudative biochemically. Culture of pleural fluid and blood grew Brucella species. Fever subsided with Brucella chemotherapy, but pleural effusion persisted. Computed tomographic (CT) chest scan showed a large loculated pleural effusion, which failed to resolve despite repeated aspirations under CT guidance. Fluid was always found to be haemorrhagic. Finally, lung decortication was done with successful outcome. Conclusion: This case showed that brucellosis can cause haemorrhagic pleural effusion that needs lung decortication.
Identification of Adenosine Receptor Subtypes Expressed in the Human Endothelial-Like ECV304 Cells
Authors: Kobayashi Ryoko , Saitoh Osamu , Nakata Hiroyasu
Published: March 2005

Adenosine, acting through its receptors, is a potent endogenous regulator of endothelial cells. The cultured endothelial cells expressing adenosine receptors are thus important for elucidation of molecular mechanism of adenosine functions in these cell systems. Therefore, identification of adenosine receptors in the human ECV304 cell line derived from a human umbilical vein endothelial cell culture was performed. RT-PCR experiments revealed that ECV304 cells express mRNAs for A1 and A2B adenosine receptors. The expression of mRNA for A2A adenosine receptor was not in a significant level and that for A3 adenosine receptor was not detected. The binding study of ECV304 cell membrane fractions using various radiolabeled ligands for adenosine receptors indicated the presence of A1 adenosine receptors 245 fmol/mg of membrane proteins, but the specific binding for A2A and for A3 adenosine receptors were found to be negligible. The functional expression of A1 and A2B adenosine receptors in ECV304 cells was detected by assays for adenosine-3′,5′-cyclic monophosphate and for extracellular signal-regulated kinase, but that of A2A adenosine receptors was not confirmed under the assay conditions employed. In conclusion, this study presented evidence for functional A1 and A2B adenosine receptors in human endothelial-like ECV304 cells, indicating that ECV304 cells can be a good model for the study of adenosine receptors, especially for A2B adenosine receptor, in endothelial cells.
The Effect of Simvastatin Treatment on the Amyloid Precursor Protein and Brain Cholesterol Metabolism in Patients with Alzheimer’s Disease
Authors: Höglund K. , Thelen K.M. , Syversen S. , Sjögren M. , von Bergmann K. , Wallin A. , Vanmechelen E. , Vanderstichele H. , Lütjohann D. , Blennow K.
Published: March 2005

During the last years, several clinical studies have been published trying to elucidate the effect of statin treatment on amyloid precursor protein (APP) processing and metabolism of brain cholesterol in Alzheimer’s disease (AD) in humans. We present an open biochemical study where 19 patients with AD have been treated with simvastatin (20 mg/day) for 12 months. The aim was to further investigate the effect of simvastatin treatment on cerebrospinal fluid (CSF) biomarkers of APP processing, AD biomarkers as total tau and tau phosphorylated at threonine 181, brain cholesterol metabolism as well as on cognitive decline in patients with AD. Despite biochemical data suggesting that treatment with 20 mg/day of simvastatin for 12 months does affect the brain cholesterol metabolism, we did not find any change in CSF or plasma levels of β-amyloid (Aβ)1–42. However, by analysis of APP isoforms, we found that statin treatment may favor the nonamyloidogenic pathway of APP processing. The relevance and mechanism between statin treatment and AD has to be further elucidated by using statins of different lipophility in different dosages over a longer period of time.
Motor Function in Subjects with Mild Cognitive Impairment and Early Alzheimer’s Disease
Authors: Pettersson A.F. , Olsson E. , Wahlund L.-O.
Published: March 2005

Basic mobility, balance, gait and dual-task performance were characterised in 140 consecutive subjects referred to a multidisciplinary university hospital in a geriatric setting for cognitive symptoms and possible dementia. After completion of an extensive diagnostic evaluation, subjects were classified into four diagnostic categories: no cognitive impairment, mild cognitive impairment, Alzheimer’s disease (AD) and other dementia. Mean age was 57 ± 9.2, 60 ± 7.3, 68 ± 9.9 and 64 ± 10.5, respectively. Data on motor function, medication use and presence of white matter changes were evaluated and compared between the diagnostic groups. Motor function seems to be affected in very mild AD but not in mild cognitive impairment, as assessed with performance-based tests. AD subjects were slowed and had difficulties in dual-task performance requiring concurrently performing a cognitive task while walking.
Does Alzheimer’s Disease Affect Hippocampal Asymmetry? Evidence from a Cross-Sectional and Longitudinal Volumetric MRI Study
Authors: Barnes Josephine , Scahill Rachael I. , Schott Jonathan M. , Frost Chris , Rossor Martin N. , Fox Nick C.
Published: March 2005

Objective: To determine whether Alzheimer’s disease (AD) is associated with preferential atrophy of either the left or right hippocampus. Methods: We examined right-left asymmetry in hippocampal volume and atrophy rates in 32 subjects with probable AD and 50 age-matched controls. Hippocampi were measured on two serial volumetric MRI scans using a technique that minimizes laterality bias. Results: We found a non-significant trend for right > left (R > L) asymmetry in controls at both time points (R > L: 1.7%; CI: –0.3–3.7%; p = 0.1). AD subjects showed a similar non-significant trend for R > L asymmetry at baseline (R > L: 1.8%; CI: –1.9–5.5%; p = 0.32), but not at repeat (p = 0.739). Change in R/L ratio between visits in AD patients was significant (p = 0.02). The AD group had significantly higher variance in these ratios than the controls at baseline (p = 0.02), but not repeat (p = 0.06). AD patients had higher atrophy rates than controls (p < 0.001). Mean (CI) annualized atrophy rates for left and right hippocampi were 1.2% (0.5–1.8%) and 1.1% (0.5–1.8%) for the controls, and 4.6% (3.3–6.0%) and 6.3% (4.9–7.8%) for AD subjects. There was no significant asymmetry in atrophy rates in controls (p = 0.9), but borderline significantly higher atrophy rates in the right hippocampus of the AD group (p = 0.05) compared to the left. Presence of an APOEΕ4 allele had no significant effect on the size, asymmetry or atrophy rates in AD (p > 0.20). Conclusions: We report minor R > L asymmetry in hippocampal volumes in controls and present some evidence to suggest that there is a change in the natural R > L asymmetry during the progression of AD.
Study of Cardiac Rate and Rhythm Patterns in Ambulatory and Hospitalized Children
Authors: Massin Martial M. , Bourguignont Astrid , Gérard Paul
Published: March 2005

Our aim was to underline possible differences in heart rate and rhythm patterns between ambulatory and hospitalized children. Holter monitoring was performed on 264 healthy ambulatory children and on 112 children who were hospitalized for noncardiotoxic conditions. Maximal, mean and minimal heart rates decreased with age. Maximal heart rate was significantly higher in ambulatory schoolchildren and adolescents than in hospitalized ones. Sinus arrhythmia was noted on every recording. Some children had episodes of first- or second-degree atrioventricular block while sleeping. Supraventricular and uniform ventricular extrasystoles were common. The incidence of all types of arrhythmia and conduction disturbances was similar in ambulatory and hospitalized children. These data can be taken as a basis for the analysis of 24-hour electrocardiogram monitoring in ambulatory but also in hospitalized children.
Levels of, and Factors Associated with, C-Reactive Protein in Employees Attending a Company-Sponsored Cardiac Screening Program
Authors: Godefroi Robert , Klementowicz Peter , Pepler Catherine , Lewis Barbara , McDonough Kenneth , Goldberg Robert J.
Published: March 2005

Background: Relatively limited contemporary information is available about the distribution of, and factors associated with, levels of C-reactive protein (CRP) in adult men and women. The purpose of our descriptive study was to examine the prevalence and predictors of this marker of inflammation in a sample of employed adults attending a worksite cardiovascular screening program. Methods: The study sample consisted of 876 men and women between the ages of 21 and 77 years from 6 locations of the parent company. These individuals attended an employer-sponsored cardiovascular screening and wellness program during 2003. A standardized questionnaire was administered to all study participants, and a number of different coronary risk factors were measured. Results: Approximately 25% of the study sample was classified as having elevated CRP levels (≧3 mg/l). Women, obese individuals, subjects with increasing heart rate and higher levels of serum triglycerides were more likely to have elevated concentrations of CRP than the corresponding comparison groups. Subjects who reported regularly exercising, individuals with a history of heart disease and those with lower total cholesterol levels were less likely to have elevated CRP levels. A relatively similar risk factor profile was noted in individuals without a self-reported history of prior cardiovascular disease. Conclusions: The results of our cross-sectional observational study suggest that the prevalence of elevated CRP levels in the general adult population is considerable. A number of demographic, comorbid and other factors are associated with this inflammatory marker of increased risk of cardiovascular disease, which demands increased attention and modification of potential predisposing factors.
Lack of Association between Common Polymorphisms in Genes of the Renin-Angiotensin System and Mortality after Myocardial Infarction
Authors: Andrikopoulos George K. , Tzeis Stylianos M. , Needham Edward W. , Richter Dimitri J. , Zairis Michalis N. , Gialafos Elias J. , Kardaras Fotios G. , Foussas Stefanos G. , Stefanadis Christodoulos I. , Toutouzas Pavlos K. , Mattu Raj
Published: March 2005

The insertion/deletion (I/D) polymorphism in the ACE gene and the A1166C polymorphism in the AT1R gene have been associated with left ventricular remodelling and prognosis after acute myocardial infarction (AMI). We investigated whether these genetic variants associate with impaired left ventricular ejection fraction (LVEF) and increased risk for in-hospital mortality after AMI. Consecutive AMI patients were recruited on admission and were genotyped for the above-mentioned polymorphisms. The frequency of the studied genotypes did not differ significantly between deceased patients and those who survived. The LVEF did not differ among patients with or without the DD genotype (45 ± 10 vs. 45 ± 10%, p = 0.892) or the CC genotype (45 ± 10 vs. 46 ± 10%, p = 0.859). These data question the role of the studied genotypes in the pathogenesis of AMI and do not support the previously supported hypothesis that these genotypes influence prognosis after AMI.
A Recombinant Precursor of the Mustard Allergen Sin a 1 Retains the Biochemical and Immunological Features of the Heterodimeric Native Protein
Authors: Palomares Oscar , Cuesta-Herranz Javier , Rodríguez Rosalía , Villalba Mayte
Published: March 2005

Background: Mustard has been an important cause of food allergy of increasing incidence in the last years. Sin a 1, a storage 2S albumin, is the most relevant allergen from this spice. Methods:Pichia pastoris has been used as host for the recombinant production of the precursor form of Sin a 1 (rproSin a 1). rproSin a 1 was purified to homogeneity by three chromatographic steps: gel filtration, anion exchange and reverse-phase HPLC. Molecular characterization was performed using Edman degradation, mass spectrometry, amino acid composition, and circular dichroism. Immunological properties were analyzed by immunoblotting, ELISA, and ELISA inhibition experiments. Results: We overexpressed rproSin a 1 as a single polypeptide with both large and small chains linked by an internal processed fragment at high yield. The purified rproSin a 1 (>95%) was obtained as a monomeric and soluble protein. rproSin a 1 showed equivalent structural and immunological properties to natural heterodimeric Sin a 1 allergen. rproSin a 1 was recognized by 75% of the patients allergic to mustard. The inhibitory capacity of rproSin a 1 to the total allergenicity of mustard extracts varied from 13 to 83% in different patients, with a mean value of 54%. Conclusions: rproSin a 1 is a good candidate to replace natural allergen in diagnosis protocols of mustard allergy. P. pastoris has been demonstrated to be a suitable expression system for the production of allergenic derivates of Sin a 1 that could be used for immunotherapy purposes in future.
Elevation of Plasma Soluble T Cell Costimulatory Molecules CTLA-4, CD28 and CD80 in Children with Allergic Asthma
Authors: Ip W.K. , Wong C.K. , Leung T.F. , Lam C.W.K.
Published: March 2005

Background: The surface expression of T cell costimulatory molecules CTLA-4 and CD28 and their counter-ligands, B7 molecules (CD80, CD86), is differentially induced for T cell activation and expansion in allergic asthma. However, the role of their soluble forms in plasma has not yet been elucidated. In this study, we investigated whether expression is altered and whether soluble costimulatory molecules are clinically relevant in asthmatic patients. Methods: Plasma concentrations of soluble CTLA-4 (sCTLA-4), CD28, CD80 and CD86 in 51 children with chronic allergic asthma with or without inhaled corticosteroid treatment, and 22 sex- and age-matched control subjects were measured by enzyme-linked immunosorbent assay. Plasma total IgE concentration was measured using a microparticle immunoassay. Results: Asthmatic patients had higher logarithmic plasma total IgE concentration (IgElog) than healthy subjects (p < 0.0001). In non-steroid-treated patients, plasma sCTLA-4, sCD28 and sCD80 but not sCD86 concentrations were significantly higher than those of control subjects (all p < 0.05). Plasma sCD80 and sCD86 but not sCTLA-4 and sCD28 concentrations correlated significantly with IgElog of all subjects (p < 0.05). There were also significant positive correlations between sCTLA-4 and sCD28 (p = 0.0007), and between sCD80 and sCD86 in all asthmatic patients (p = 0.001). Conclusions: Plasma sCTLA-4, sCD28 and sCD80 concentrations are elevated in allergic asthma. The increased expression of these soluble proteins may reflect the dysregulation of T cell activation, contributing to the immunopathogenesis of allergic asthma.
Biological Relevance of E-Cadherin-Catenin Complex Proteins in Primary Epithelial Ovarian Tumours
Authors: Faleiro-Rodrigues C. , Macedo-Pinto I.M. , Maia S.S. , Vieira R.H. , Lopes C.S.
Published: March 2005

This studyanalysed the biological relevance of E-cadherin, α-catenin, β-catenin and γ-catenin immunoexpression pattern (reduced vs. preserved phenotype) in epithelial ovarian tumours. Immunohistochemistry was used to evaluate the expression of these proteins in 154 epithelial ovarian tumours, consisting of 17 benign, 33 borderline and 104 malignant tumours. In borderline tumours, the immunoexpression pattern of E-cadherin (p = 0.014) and α-catenin (p = 0.030) associated with histological type. In malignant tumours, the immunoexpression pattern of E-cadherin was related with histological type (p = 0.001). The immunoexpression pattern of β-catenin associated with histological type and tumour differentiation (p = 0.005, p = 0.025, respectively). The preserved phenotype of E-cadherin was most frequently observed in mucinous tumours, whereas reduced E-cadherin was most frequently observed in serous tumours. The preserved phenotype of β-catenin associated with endometrioid carcinomas, while reduced β-catenin associated with poorly differentiated serous and clear cell carcinomas. Although the reduced phenotype was the most frequent immunoexpression observed for all proteins of the E-cadherin-catenin complex in epithelial ovarian tumours, only β-catenin showed a significant difference between benign, borderline and malignant tumours (p = 0.045), since borderline and malignant tumours most frequently showed the reduced phenotype. The immunohistochemical profile of β-catenin was shown to be of biological relevance: reduced β-catenin was correlated with loss of tumour differentiation and serous carcinomas that are known to depict aggressive biological behaviour in epithelial ovarian tumours.
Gastric Perception Thresholds Are Low and Sensory Neuropeptide Levels High in Helicobacter pylori-Positive Functional Dyspepsia
Authors: Mönnikes Hubert , van der Voort Ivo R. , Wollenberg Birgit , Heymann-Mönnikes Ingeborg , Tebbe Johannes J. , Alt Wibke , Arnold Rudolf , Klapp Burghard F. , Wiedenmann Bertram , McGregor Gerard P.
Published: March 2005

Background and Aims: In functional dyspepsia (FD) decreased perception levels can be shown on gastric distension. Substance P (SP) and calcitonin gene-related peptide (CGRP) are involved in the sensitization of afferent neuronal pathways due to chronic inflammation. The role of Helicobacter pylori-induced gastric mucosal inflammation in the pathogenesis of FD is controversial. The aim of this study was to assess whether FD patients have altered mucosal concentrations of CGRP and SP, and to investigate whether this is associated with visceral hypersensitivity or H. pylori infection. Methods: Gastrointestinal symptoms, H. pylori status, perception thresholds at gastric balloon distension, and gastric mucosal concentrations of CGRP and SP were determined in 13 FD patients and 18 healthy controls (HC). Results: In H. pylori-positive FD patients discomfort and pain thresholds on gastric distension were lower compared to other groups. Antral mucosal levels of CGRP and SP were higher in H. pylori-positive subjects. In FD significantly negative correlations between discomfort and pain thresholds and antral mucosal concentrations of CGRP and SP were observed. Conclusions: In FD low perception thresholds on gastric distension are associated with high levels of CGRP and SP in the antrum, suggesting that sensory neuropeptides are involved in FD pathophysiology.
Effects of Antenatal Glucocorticoids on Circulatory Adaptation at Birth in the Ovine Fetus
Authors: Houfflin-Debarge V. , Deruelle P. , Jaillard S. , Magnenant E. , Riou Y. , Devisme L. , Puech F. , Storme L.
Published: March 2005

Objective: Adaptation to extra-uterine life requires dramatic increase in pulmonary blood flow. Mechanisms that induce pulmonary vasodilatation at birth are incompletely understood but include alveolar ventilation, increase in PaO2, and production of vasoactive mediators. We hypothesized that antenatal glucocorticoids (GC) increase pulmonary vasodilatation to birth-related stimuli. Study Design: To test this hypothesis, we studied the pulmonary hemodynamic response at birth to mechanical ventilation with low (<10%) and then with high (100%) FiO2 in chronically prepared late-gestation fetal lambs treated or not by antenatal maternal steroids. Results: Basal mean aortic and pulmonary artery pressure (PAP), left pulmonary blood flow, pulmonary vascular resistance (PVR), and blood gas were similar between control and dexamethasone-treated animals (GC group). During mechanical ventilation with low FiO2, mean PVR decreased by 40% in the control group (from 0.44 ± 0.01 to 0.25 ± 0.01 mm Hg/ml/min) and by 60% in the GC group (from 0.44 ± 0.02 to 0.19 ± 0.02 mm Hg/ml/min) (p < 0.01). When subsequently ventilated with 100% O2, there was no difference in PVR decrease between groups (0.15 ± 0.02 mm Hg/ml/min in the GC group vs. 0.14 ± 0.01 mm Hg/ml/min in the control group). Conclusion: Antenatal GC enhance pulmonary vasodilatation induced by alveolar ventilation at birth but do not alter the pulmonary vascular response to O2. We speculate that antenatal steroids exposure improve adaptation at birth through acceleration of both parenchymal and vascular lung maturation.
Effects of the Tyrosine Kinase Inhibitor Imatinib on Neuroendocrine Tumor Cell Growth
Authors: Lankat-Buttgereit Brigitte , Hörsch Dieter , Barth Peter , Arnold Rudolf , Blöcker Silke , Göke Rüdiger
Published: March 2005

Aim: We investigated the effects of the tyrosine kinase inhibitor imatinib (Gleevec®) on neuroendocrine tumor cells. Methods: Neuroendocrine tumor cells were incubated without and with imatinib. The effects on growth were examined by methylthiazoletetrazolium (MTT) assay. The c-Kit expression in human endocrine tumor tissue and cell lines was determined by immunohistochemistry and Western blot analysis, respectively. Cytotoxicity assay was performed by fluorescence-activated cell sorting. The telomerase activity was determined using the telomeric repeat amplification protocol. Results: 28% of the insulinomas, 100% of the gastrinomas, and 38% of the carcinoids expressed c-Kit. Imatinib at concentrations >5 µM inhibited cell proliferation and induced apoptosis in both c-Kit-positive and c-Kit-negative cell lines. The PI-3K inhibitor wortmannin did not enhance the effects of imatinib. Imatinib did not sensitize endocrine tumor cells to doxorubicin and 5-fluorouracil. Imatinib inhibited the telomerase activity. Conclusion: Imatinib inhibits neuroendocrine tumor cell growth independently of c-Kit by inhibition of other tyrosine kinases or through tyrosine kinase independent pathways.
Extended Learning Time and Student Accountability: Assessing Outcomes and Options for Elementary and Middle Grades
Authors: Smith BetsAnn , Roderick Melissa , Degener Sophie C.
Published: March 2005

This article considers the relative impacts of student accountability policies and extended learning programs on the achievement gains of elementary and middle grade students. It shares qualitative and quantitative analyses of an extended learning time initiative implemented in conjunction with a high-stakes testing and retention policy. The influences of the extended learning initiative on students, teachers, and school organizations are described, and the achievement effects associated with the initiative are compared to those associated with the retention policy. Findings are interpreted in light of demands made by the No Child Left Behind Act and the concerns of policy makers and administrators as to how best to employ incentives, sanctions, and/or supplemental supports to promote student and school achievement. In closing, researchers are invited to pursue work that uncovers the specific effects of these strategies among particular students and learning contexts.
Conducting Fabric-reinforced Polyaniline Film Using p-Chlorophenol as Secondary Dopant for the Control of Electromagnetic Radiations
Authors: Geetha Sivasubramanian , Kumar Konda Kannan Satheesh , Trivedi Dinesh Chandra
Published: March 2005

Polyaniline (PAn) is a commercially viable conducting polymer exhibiting enough metallic conductivity to replace carbon/metal filled composites as a shield to control electromagnetic radiations. In this paper, we discuss the process to achieve a pore-free conducting fabric reinforced with PAn. The process involves the pretreatment of glass fabric before the in situ polymerization of aniline in the presence of either p-toluenesulfonic acid (PTSA) or camphor-10-sulfonic acid (CSA). The conducting E-glass fabric is coated with a conductive paste prepared from PAn-PTSA or PAn-CSA/p-chlorophenol (PCP) as the secondary dopant come solvent at 60 C to achieve a pore-free flexible conducting surface. The reinforced conducting fabrics are characterized by UV-Vis spectroscopy, conductivity, scanning electron microscopy (SEM), X-ray diffraction study (XRD), and thermogravimetric analysis (TGA). The electromagnetic interference shielding effectiveness (EMI SE) studies are carried out using the co-axial transmission line method in the frequency range of 0.1-1000 MHz. The pore-free conducting fabric reinforced with PAn-PTSA/PCP and PAn-CSA/PCP of 3 mm thickness offered an EMI SE of 58 and 55 dB at 1000 MHz. The study indicates that the SE increases with the increase in thickness and conductivity of the test coupon.
Lignocellulose-based Hybrid Bilayer Laminate Composite: Part I - Studies on Tensile and Impact Behavior of Oil Palm Fiber-Glass Fiber-reinforced Epoxy Resin
Authors: Hariharan Abu Bakar A. , Khalil H. P. S. Abdul
Published: March 2005

The tensile and impact behavior of the oil palm fiber-glass fiber hybrid bilayer laminate composites are studied. The fiber mats are impregnated with epoxy resin and cured at 100°C for 1 h followed by post curing at 105°C. The hybridization of the oil palm fibers with glass fibers increases the tensile strength, the Young’s modulus, and also the elongation at break of the hybrid composites. A negative hybrid effect is observed for the tensile strength and Young’s modulus while a positive hybrid effect was observed for the elongation at break of the hybrid composites. The impact strength of the hybrid composite increases with the addition of glass fibers. The hybrid composites which are impacted at the glass fiber layer exhibit a higher impact strength and a positive hybrid effect compared to those impacted at the oil palm fiber layer. The scanning electron micrographs and photomicrographs of tensile and impact fracture samples are taken to study the failure mechanism and fiber-matrix interface adhesion.
Finite Element Modeling of a Membrane Sector of a Satellite Reflector Made of Triaxial Composites
Authors: Zhao Qi , Hoa S. V.
Published: March 2005

Single layers of triaxial woven fabric composites have been used to make communication satellite reflectors due to their extremely light weight with good stiffness and strength property. Special superfinite elements have been developed for the analysis of these lightweight materials. These superfinite elements are used for the deflection and stress analysis of a membrane sector of the satellite reflector subjected to lateral pressure. Due to the significant difference in the size of the satellite structure (order of meters) and the size of the superfinite elements (order of millimeters) it is not possible to model the satellite structure using the superfinite elements and computer facilities available in most labs (personal computers). In the process of finding a solution to this problem, a special similitude behavior for the deflection of the curved panels made of triaxial fabrics was discovered. Using this behavior, the deflection of a large-size reflector panel (order of meters) can be analyzed using models in the millimeters size range. Stresses in the triax reflector model were also calculated. However, no special similitude behavior was obtained for the stresses.
‘Leaps of Faith’ and MMR: An Empirical Study of Trust
Authors: Brownlie Julie , Howson Alexandra
Published: March 2005

Möllering has argued for sociological research on trust that pays attention to the ‘fine details of interpretation’ and begins from the perspectives of those engaged in relations of trust. In this article we explore what it would mean to take up Möllering’s challenge to explore the interpretative elements of trust and the ‘leaps of faith’ trusting entails.We do this through an empirical study of parental and professional talk about the MMR (measles, mumps and rubella) vaccination. We examine trust as operating in a number of interrelated ways: as a practice based on knowledge; as a ‘leap of faith’ experienced through relationality and familiarity; as working at a system level; and as shaped by relations of governance and by anxieties to do with the nature of social and technological change. Through this analysis, we suggest how an interpretive approach to thinking about trust is a worthwhile exercise.
Generalization in Qualitative Research
Authors: Payne Geoff , Williams Malcolm
Published: March 2005

Earlier treatments of moderatum generalization (e.g. Williams, 2000a) explicitly addressed interpretivist sociology. This article extends that earlier argument by examining some of its implications for a wider range of qualitative research methods. It first adopts an empirical approach, providing concrete illustrations from the most recent volume of Sociology of what sociologists actually do when describing the meaning of their findings. In the light of this, we reconsider the significance of moderatum generalization for research practice and the status of sociological knowledge, in particular making the case that research design should plan for anticipated generalizations, and that generalization should be more explicitly formulated within a context of supporting evidence.
Sabbath, Identity and Universalism Go Together after the Return from Exile
Authors: Gosse Bernard
Published: March 2005

In Isaiah 56.1-2 there is identification between ‘to keep justice’ and ‘to keep the Sabbath’. The Sabbath plays an important part in the construction ofexilic and post-exilic identity. At the same time, ‘to keep the Sabbath’ permits the eunuch and foreigner (56.3) to hope that they will enter the house of the Lord (56.4-7). This article explores the relationship between Isa. 56.1-2and the verses immediately following, as well as Ezekiel 18–20, chapters inwhich the Sabbath and justice are also associated. The thematic association of the keeping of justice and the keeping of the Sabbath thus seems to highlight an interesting case of identity and universalism going together.
The Use of Knee Braces, Part 1: Prophylactic Knee Braces in Contact Sports
Authors: Najibi Soheil , Albright John P.
Published: March 2005

Surrogate knee model biomechanical studies have indicated that off-the-shelf braces provide 20% to 30% greater resistance to a lateral blow when the knee is in full extension. Custom functional braces doubled the protective effects and proved effective with the knee in some flexion. Although functional performance studies are not consistent, preventive knee braces may slow straight-ahead sprint speed, cause early fatigue, and increase muscular relaxation pressures, energy expenditure, blood lactate levels, maximal torque output, oxygen consumption, and heart rate. Two epidemiologic studies have been performed. At West Point, a randomized control study of 71 injuries in 1396 cadets indicated knee brace effectiveness with a statistically higher rate of injury in the control group (3.4/1000 exposures) than in the braced group (1.5/1000 exposures), with the most significance for medial collateral ligament sprains in defensive players. The Big Ten Conference conducted a descriptive study of 100 medial collateral ligament sprains among 987 players in different positions, strings, and types of session. Brace-wear tendency varied directly with the unbraced player counterpart's risk of medial collateral ligament sprain, with the nonplayer linemen experiencing both the greatest risk of unbraced practice session injury (0.0801 injuries/1000 exposures) and the highest incidence of brace wear (85%). During practices, there was a nonsignificant but very consistent reduction in injury rate for braced players in every position and string. During games, there was also a reduced rate for linemen and the linebacker/tight end group. The study concluded that although the issue is not closed, preventive knee braces appear to offer some protection to the medial collateral ligament from a contact injury involving a valgus blow, but there may be negative effects on performance level, leg cramping, and fatigue symptoms.