bluuebunny/crossref_metadata_2025 huggingface dataset:
Simplex space–time meshes in finite element simulations
Authors: Behr Marek
Published: June 2008

A straightforward method for generating simplex space–time meshes is presented, allowing arbitrary temporal refinement in selected portions of space–time slabs. The method increases the flexibility of space–time discretizations, even in the absence of dedicated space–time mesh generation tools. The resulting tetrahedral (for 2D problems) and pentatope (for 3D problems) meshes are tested in the context of advection–diffusion equation, and are shown to provide reasonable solutions, while enabling varying time refinement in portions of the domain. Copyright © 2008 John Wiley & Sons, Ltd.
The combined effects of non‐planarity and asymmetry on primary and secondary flows in the small bronchial tubes
Authors: Soni B. , Lindley C. , Thompson D.
Published: June 2008

The laminar flow in the small bronchial tubes is quite complex due to the presence of vortex‐dominated, secondary flows. In this paper, we report the results of a numerical investigation of the simultaneous effects of asymmetric and non‐planar branching on the primary and secondary flows in the small bronchial tubes, i.e. generations 6–12. We simulate steady‐state inspiratory flow at a Reynolds number of 1000 in three‐generation, asymmetric planar and non‐planar bronchial tube models. The non‐planar model was defined by applying a 90° out‐of‐plane rotation to the third‐generation branches. A detailed mesh refinement study was performed in order to demonstrate mesh independence. Significant differences were observed between flows in the planar and non‐planar models. An uneven mass flow distribution was observed in the non‐planar model in contrast to the evenly distributed mass flow in the planar model. The secondary flows created symmetric vortex patterns in the planar model, whereas vortex symmetry was lost in the non‐planar model. These results illustrate the importance of incorporating asymmetry in addition to non‐planarity in the geometric models. Copyright © 2008 John Wiley & Sons, Ltd.
Sigma transformation and ALE formulation for three‐dimensional free surface flows
Authors: Decoene A. , Gerbeau J. F.
Published: June 2008

In this paper we establish a link between the sigma transformation approach and the arbitrary Lagrangian–Eulerian (ALE) approach. For that purpose we introduce the ALE‐sigma (ALES) approach, which consists in an ALE interpretation of the sigma transformation. Taking advantage of this new approach, we propose a general ALES transformation, allowing for a great adaptability of the vertical discretization and therefore overcoming some drawbacks of the classical sigma transformation. Numerical results are presented, showing the advantages of this general coordinate system, as, for example, a better representation of horizontal stratifications. Copyright © 2008 John Wiley & Sons, Ltd.
CFD analysis of an oscillating wing at various reduced frequencies
Authors: Umar Farooq , Hamdani Hossein Raza , Anwar‐ul‐Haque  , Chaudhry Sajid Raza , Parvez Khalid
Published: June 2008

The effect of various reduced frequencies has been examined for an oscillating aspect ratio 10 NACA 0015 wing. An unsteady, compressible three‐dimensional (3D) Navier–Stokes code based on Beam and Warming algorithm with the Baldwin–Lomax turbulence model has been used. The code is validated for the study against published experimental data. The 3D unsteady flow field is simulated for reduced frequency values of 0.1, 0.2 and 0.3 for a fixed mean angle of attack position and fixed amplitude. The type of motion is sinusoidal harmonic. The force coefficients, pressure distributions and flow visualization show that at the given conditions the flow remains attached to the wing surface even at high angles of attack with no clear separation or typical light‐to‐deep category of dynamic stall. Increased magnitude of hysteresis and higher gradients are seen at higher reduced frequencies. The 3D effects are even found at midspan locations. In addition, the rate of decrease in lift near the wing tips compared with the wing root is not much like in the static cases. Copyright © 2008 John Wiley & Sons, Ltd.
Solution to transient Navier–Stokes equations by the coupling of differential quadrature time integration scheme with dual reciprocity boundary element method
Authors: Bozkaya C. , Tezer‐Sezgin M.
Published: June 2008

The two‐dimensional time‐dependent Navier–Stokes equations in terms of the vorticity and the stream function are solved numerically by using the coupling of the dual reciprocity boundary element method (DRBEM) in space with the differential quadrature method (DQM) in time. In DRBEM application, the convective and the time derivative terms in the vorticity transport equation are considered as the nonhomogeneity in the equation and are approximated by radial basis functions. The solution to the Poisson equation, which links stream function and vorticity with an initial vorticity guess, produces velocity components in turn for the solution to vorticity transport equation. The DRBEM formulation of the vorticity transport equation results in an initial value problem represented by a system of first‐order ordinary differential equations in time. When the DQM discretizes this system in time direction, we obtain a system of linear algebraic equations, which gives the solution vector for vorticity at any required time level. The procedure outlined here is also applied to solve the problem of two‐dimensional natural convection in a cavity by utilizing an iteration among the stream function, the vorticity transport and the energy equations as well. The test problems include two‐dimensional flow in a cavity when a force is present, the lid‐driven cavity and the natural convection in a square cavity. The numerical results are visualized in terms of stream function, vorticity and temperature contours for several values of Reynolds (Re) and Rayleigh (Ra) numbers. Copyright © 2008 John Wiley & Sons, Ltd.
The geometric combination of Bayesian forecasting models
Authors: Faria A. E. , Mubwandarikwa E.
Published: June 2008

A nonlinear geometric combination of statistical models is proposed as an alternative approach to the usual linear combination or mixture. Contrary to the linear, the geometric model is closed under the regular exponential family of distributions, as we show. As a consequence, the distribution which results from the combination is unimodal and a single location parameter can be chosen for decision making. In the case of Student t‐distributions (of particular interest in forecasting) the geometric combination can be unimodal under a sufficient condition we have established. A comparative analysis between the geometric and linear combinations of predictive distributions from three Bayesian regression dynamic linear models, in a case of beer sales forecasting in Zimbabwe, shows the geometric model to consistently outperform its linear counterpart as well as its component models. Copyright © 2008 John Wiley & Sons, Ltd.
A Single‐Chamber SOFC Stack: Energy Recovery from Engine Exhaust
Authors: Nagao M. , Yano M. , Okamoto K. , Tomita A. , Uchiyama Y. , Uchiyama N. , Hibino T.
Published: June 2008

The feasibility of applying single‐chamber solid oxide fuel cells (SC‐SOFCs) to power generators for exhaust energy recovery was investigated using both model and actual exhaust gases. In the experiments with model exhaust gases, a single cell, Ni‐Ce0.8Sm0.2O1.9/YSZ/La0.8Sr0.2MnO3, was operated in a mixture of gases containing ppm levels of CH4, C2H6, C3H8, C4H10 and O2. The cell performance was considerably affected by the molar ratio of total hydrocarbons to O2, the operating temperature and the gas flow rate. The optimal operating conditions of the SC‐SOFC were found to be similar to those found in actual exhaust from gasoline engines. Thermal and mechanical loading performance tests demonstrated high tolerance towards thermal cycling and breakage of the electrolyte. Performance tests with and without a gas separator suggested that there is no requirement for a gas separator in an actual exhaust. In the experiments with actual exhaust gases, a 12‐cell stack was installed to a 250‐cm3 engine. The open circuit voltages (OCVs) were between 5 and 8 V and independent of the number of revolutions, but were lower than the values expected from the model exhaust results. This was considered to be due to the deviation of the actual exhaust gases from the model gases. Nevertheless, the stack performance was reproducible and stable in the range from 1,500 to 5,500 rpm. The resultant peak power reached above 1 W at 4,500 rpm.
Deregulated expression of miR‐106a predicts survival in human colon cancer patients
Authors: Díaz Raquel , Silva Javier , García José M. , Lorenzo Yolanda , García Vanesa , Peña Cristina , Rodríguez Rufo , Muñoz Concepción , García Fernando , Bonilla Félix , Domínguez Gemma
Published: June 2008

MicroRNAs (miRNAs) are noncoding RNAs that regulate expression of target mRNAs and are controlled by tumor suppressors and oncogenes. Altered expression of specific miRNAs in several tumor types and its association with poor prognosis parameters have been reported. Fewer data are available on its impact on patients' survival. We studied the impact of the expression ofmiR‐17‐5p,miR‐106a, andmiR‐126on survival and its correlation with the levels of their target mRNAs and host gene andTP53alterations. We assessed in 110 colon cancer patients the levels ofmiR‐17‐5p,miR‐106a,miR‐126,E2F1, andEGFL7by quantitative real‐time RT‐PCR and loss of heterozygosity (LOH) in theTP53region. Tumor characteristics, disease‐free survival (DFS), and overall survival (OS) were examined in each patient. Altered expression ofmiR‐17‐5p,miR‐106a, andEGFL7was associated with pathological tumor features of poor prognosis. Downregulation ofmiR‐106apredicted shortened DFS (P= 0.03) and OS (P= 0.04).miR‐17‐5pcorrelated with DFS only at early stages (P= 0.07). Inverse correlations were found betweenmiR‐17‐5pandmiR‐106alevels and their target expression,E2F1(P= 0.04 andP= 0.03, respectively). No correlation was found betweenmiR‐126expression and its host gene levels,EGFL7.miR‐106aderegulation was revealed as a marker of DFS and OS independent of tumor stage. The lack of association between expression ofmiR‐126and its host geneEGFL7suggests their regulation by independent stimuli. Inverse correlation betweenmiR‐17‐5pandmiR‐106aandE2F1levels supportsE2F1as a target mRNA for the two miRNAs. © 2008 Wiley‐Liss, Inc.
A Numerical Simulation Model for Shield Tunnelling with Compressed Air Support
Authors: Nagel Felix , Stascheit Janosch , Meschke Günther
Published: June 2008

This paper is concerned with a numerical simulation model (ekate) specifically designed for shield tunnelling in fully and partially saturated soils based upon the Finite Element Method (FEM). The model considers all relevant components – the soil, the lining, the tail void grouting, the hydraulic jacks and different types of face support – involved in shield tunnelling. The surrounding soft soil is formulated as a three‐phase material, consisting of the soil skeleton, pore water and air. This model allows for the simulation of consolidation processes in partially saturated soils as well as of flow of compressed air often used as temporary face support during repair interventions at the cutting wheel. Despite the complexity connected with the relatively high degree of realism of the simulation model, only little effort is required from the user to establish a realistic 3D model for shield tunnelling. To this end an automatic model generator has been developed which allows for a user friendly generation of the discretized model including all components involved and to investigate variants with a minimum effort for the user. The model allows for realistic predictions of settlements and also provides information on deformations and stresses in the ground, the lining and the TBM, respectively. In addition to its use as a prognosis tool in the design process, in particular for tunnelling projects in sensitive urban areas, the model also may be used to assist the driving and steering process in mechanized tunnelling. The paper provides an overview over the main components of the model, the automatic model generator and the tri‐phasic representation of the soil. A simulation of a compressed air intervention of a shield tunnel in soft soil demonstrates the applicability of the model.
Systemverhalten und Prozessoptimierung beim Erddruckschild
Authors: Maidl Ulrich
Published: June 2008

Eine konsequente Analyse der Prozessdaten kann die Sicherheit, aber auch die Effektivität des Ressourceneinsatzes beim hoch technisierten Schildvortrieb erheblich steigern. Präventive Maßnahmen zur Prozessoptimierung können durch die zeitnahe Analyse des Systemverhaltens während des Bauablaufs rechtzeitig eingeleitet werden. Eine Analyse des Systemverhaltens wird durch die Aufspaltung des Bauablaufs in Teilprozesse und die Definition der Schlüsselprozesse möglich. Im folgenden Artikel wird am Beispiel des Erddruckschilds aufgezeigt, wie beim heutigen Stand der Technik Prozesse realitätsnah simuliert und während der Ausführung unter Einsatz der vorhandenen Mess‐ und Datenerfassungstechnik analysiert werden können.
Implementierung des Sicherheitsmanagements in die Planung und Bauüberwachung am Beispiel des Lainzer Tunnels Baulos LT31 Maxing
Authors: Heissenberger Roman , Lackner Johannes , Koch Daniel
Published: June 2008

Innerstädtische Bauvorhaben stellen besonders hohe Ansprüche an alle Projektbeteiligte von der Projektierungs‐ bis hin zur Ausführungsphase. Der Beitrag befasst sich mit dem konsequenten Einsatz von Sicherheitsmanagementwerkzeugen in den einzelnen Projektphasen. Dabei werden sowohl das grundsätzliche Vortriebskonzept mit der Auswahl der Vortriebsmethode und der Stützmittel in der Projektierungsphase als auch die erforderliche Anpassung im Zuge der Ausführungsphase erläutert. Weiterhin wird auf Risikofaktoren eingegangen, die sich aus den vorhandenen Randbedingungen (Grundwassersituation, Ausführungsqualität) ergeben, und Maßnahmen erläutert, die im Zuge der Ausführung das Gefährdungspotenzial minimieren.
Elliniko Extension of Athens Metro – Project Description, Structuring and Implementation
Authors: Leoutsakos George , Le Van Cuong , Doulakis Ioannis
Published: June 2008

The present paper describes the main aspects of a metro extension project in Athens – extension of line 2 to Elliniko. The general project characteristics – resembling the character of typical metro projects in a congested urban environment – the project benefits, the geology and geotechnical information, the construction methods and other special issues are presented, while the impacts of archaeology and the searching and deactivation of bombs buried from the World War II offer challenges that need to be addressed with minimum impact to the project. The project organization and structuring is also presented for a multi contract implementation with one main contractor and several smaller ones, while the project funding, budget‐cost breakdown and time schedule aspects are also addressed and compared to previous projects.
A common cortactin gene variation confers differential susceptibility to severe asthma
Authors: Ma Shwu‐Fan , Flores Carlos , Wade Michael S. , Dudek Steven M. , Nicolae Dan L. , Ober Carole , Garcia Joe G.N.
Published: June 2008

Genomic regions with replicated linkage to asthma‐related phenotypes likely harbor multiple susceptibility loci with relatively minor effects on disease susceptibility. The 11q13 chromosomal region has repeatedly been linked to asthma with five genes residing in this region with reported replicated associations. Cortactin, an actin‐binding protein encoded by the CTTN gene in 11q13, constitutes a key regulator of cytoskeletal dynamics and contractile cell machinery, events facilitated by interaction with myosin light chain kinase; encoded by MYLK, a gene we recently reported as associated with severe asthma in African Americans. To evaluate potential association of CTTN gene variation with asthma susceptibility, CTTN exons and flanking regions were re‐sequenced in 48 non‐asthmatic multiethnic samples, leading to selection of nine tagging polymorphisms for case‐control association studies in individuals of European and African descent. After ancestry adjustments, an intronic variant (rs3802780) was significantly associated with severe asthma (odds ratio [OR]: 1.71; 95% confidence interval [CI]: 1.20–2.43; p=0.003) in a joint analysis. Further analyses evidenced independent and additive effects of CTTN and MYLK risk variants for severe asthma susceptibility in African Americans (accumulated OR: 2.93, 95% CI: 1.40–6.13, p=0.004). These data suggest that CTTN gene variation may contribute to severe asthma and that the combined effects of CTTN and MYLK risk polymorphisms may further increase susceptibility to severe asthma in African Americans harboring both genetic variants. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
Ecstasy‐related deficits in the updating component of executive processes
Authors: Montgomery Catharine , Fisk John E.
Published: June 2008

Aims

Research shows that users of ecstasy (MDMA) exhibit deficits in executive processes. The updating component appears to be particularly susceptible. Less is known about the precise nature of such deficits. The present study sought to determine if ecstasy‐related deficits in memory updating are related to serial position of items presented, or length of the list of items.

Method

Seventy‐three ecstasy/polydrug users and seventy‐three non‐ecstasy users completed tasks of verbal and spatial memory running memory, recalling the most recent items, in lists of varying and unknown length. Participants were categorised according to letter and spatial span (four, five or six), producing six sub‐samples for analysis.

Results

Ecstasy‐polydrug users were impaired in four out of the six sub‐sample analyses. Three of these were due to impaired recall of earlier serial positions.

Conclusions

The results of the present study provide further support for updating deficits in ecstasy‐polydrug users. The results are suggestive of a breakdown in the maintenance of information in working memory in terms of chunking; it appears that ecstasy/polydrug users are as able as non‐ecstasy users to form memory ‘chunks’ from the items, but that such chunks are not retained as effectively. Copyright © 2008 John Wiley & Sons, Ltd.
Simvastatin induces apoptosis in human colon cancer cells and in tumor xenografts, and attenuates colitis‐associated colon cancer in mice
Authors: Cho Soo‐Jeong , Kim Joo Sung , Kim Jung Mogg , Lee Jong Yeul , Jung Hyun Chae , Song In Sung
Published: June 2008

Statins, HMG‐CoA reductase inhibitors could be associated with the risk reduction of colorectal cancer. We previously demonstrated that simvastatin inhibits NF‐κB signaling in human intestinal epithelial cells and ameliorates acute murine colitis. The aim of our study was to evaluate the effects of simvastatin on the apoptotic pathways related to NF‐κB signaling in colon cancer cells, and on anticancer effects in 2 different animal models. We treated cell lines (COLO 205 and HCT 116) with simvastatin or vehicle and determined apoptosis by cell cycle analysis, Annexin V‐FITC staining, caspase‐3 activity assay and confocal microscopy. We assessed the expression of antiapoptotic factors by RT‐PCR and Western blotting. In the colitis‐associated colon cancer (CAC) model, we induced colonic tumors in C57/BL6 mice by azoxymethane and dextran sulfate sodium administration, and evaluated simvastatin's effect on tumor growth. In the xenograft model, we evaluated its effect on the inoculated tumor growth. In both cell lines, simvastatin caused dose‐ and time‐dependent cell death. Annexin V staining significantly increased after simvastatin treatment. It augmented caspase‐3 activity and downregulated the expression of Bcl‐2, Bcl‐xL, cIAP1 and cFLIP. In the CAC model, simvastatin significantly reduced tumor development. In the xenograft model, tumors from animals treated with simvastatin had smaller volumes, larger necrotic areas, lower expression of VEGF and higher apoptotic scores. In conclusion, simvastatin inhibited colon cancer development by induction of apoptosis and suppression of angiogenesis. These results suggest that simvastatin could be a potential chemopreventive and therapeutic agent of CAC as well as de novo colon cancer. © 2008 Wiley‐Liss, Inc.
Legume and isoflavone intake and prostate cancer risk: The Multiethnic Cohort Study
Authors: Park Song‐Yi , Murphy Suzanne P. , Wilkens Lynne R. , Henderson Brian E. , Kolonel Laurence N.
Published: June 2008

Findings from studies of legume, soy and isoflavone intake and prostate cancer risk are as yet inconclusive, although soy has received considerable attention due to its high phytoestrogen content. Therefore, the present study investigated the relationship of these dietary exposures to prostate cancer risk in the Multiethnic Cohort Study in Hawaii and Los Angeles. The analyses included 82,483 men who completed a detailed quantitative food frequency questionnaire in 1993–1996. A total of 4,404 prostate cancer cases including 1,278 nonlocalized or high‐grade cases were recorded during the average follow‐up period of 8 years. Multivariate relative risks (RR) and 95% of confidence intervals (CI) were estimated using Cox proportional hazards models with age as the time metric. Among men with the highest intake of legumes, the risk reduction was 11% for total prostate cancer (RR = 0.89, 95% CI = 0.80–0.99, p for trend = 0.007) and 26% for nonlocalized or high‐grade cancer (RR = 0.74, 95% CI = 0.61–0.90, p for trend = 0.007) compared to men with the lowest intake. Similar risk reductions were observed for soy products and for legumes excluding soy products in separate analyses. We found no significant risk reduction associated with intake of total or specific isoflavones for either total prostate cancer or for nonlocalized or high‐grade cancer. The findings of our study suggest that legume intake is associated with a moderate reduction in prostate cancer risk and that the isoflavones in soy products are probably not responsible for this effect. © 2008 Wiley‐Liss, Inc.
An alternative approach to estimate the wage returns to private‐sector training
Authors: Leuven Edwin , Oosterbeek Hessel
Published: June 2008

This paper follows an alternative approach to identify the wage effects of private‐sector training. The idea is to narrow down the comparison group by only taking into consideration the workers who wanted to participate in training but did not do so because of some random event. This makes the comparison group increasingly similar to the group of participants in terms of observed individual characteristics and the characteristics of (planned) training events. At the same time, the point estimate of the average return to training consistently drops from a large and significant return to a point estimate close to zero. Copyright © 2008 John Wiley & Sons, Ltd.
Evaluation of an orthotopically implanted calcium phosphate cement containing gelatin microparticles
Authors: Link Dennis P. , van den Dolder Juliette , van den Beucken Jeroen J. J. P. , Habraken Wouter , Soede Annemieke , Boerman Otto C. , Mikos Antonios G. , Jansen John A.
Published: June 2008

This study focused on the degradation properties of gelatin microparticles incorporated in calcium phosphate (CaP) cement and the subsequent effect of these composites on bone formation. Positively charged alkaline gelatin (type A) microparticles or negatively charged acidic gelatin (type B) microparticles were incorporated in CaP cement, which was implanted in critical‐sized cranial defect in rats and left in place for 2, 4, and 8 weeks. The degradation of the gelatin was monitored using radioiodinated microparticles. After 4 and 8 weeks of implantation, a significantly faster degradation of type A gelatin over type B gelatin was found. Light microscopic analysis of the specimens showed similar bone response concerning implants containing either type A or B gelatin microparticles. At 2 weeks of implantation, a minimal amount of bone formation was observed from the cranial bone toward the implant, while after 8 weeks of implantation an entire layer of newly formed bone was present from the cranial bone toward the implant periphery. Bone ingrowth into the implant was observed at sites of gelatin microparticle degradation, predominantly at the implant periphery. Histomorphometrical evaluation did not reveal significant differences in bone formation between CaP cement incorporated with either type A or B gelatin microparticles during implantation periods up to 8 weeks. In conclusion, this study demonstrates that gelatin type influences the degradation of gelatin microparticles incorporated in CaP cements. However, this difference in degradation and the concomitant subsequent macroporosity did not induce differences in the biological response. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Effects of mobility/immobility of surface modification by 2‐methacryloyloxyethyl phosphorylcholine polymer on the durability of polyethylene for artificial joints
Authors: Kyomoto Masayuki , Moro Toru , Miyaji Fumiaki , Hashimoto Masami , Kawaguchi Hiroshi , Takatori Yoshio , Nakamura Kozo , Ishihara Kazuhiko
Published: June 2008

Surface modification is important for the improvement in medical device materials. 2‐Methacryloyloxyethyl phosphorylcholine (MPC) polymers have attracted considerable attention as surface modifiable polymers for several medical devices. In this study, we hypothesize that the structure of the surface modification layers might affect the long‐term stability, hydration kinetics, wear resistance, and so forth, of medical devices such as artificial joints, and the poly(MPC) (PMPC) grafted surface might assure the long‐term performance of such devices. Therefore, we investigate the surface properties of various surface modifications by using dip coatings of MPC‐co‐n‐butyl methacrylate (PMB30) and MPC‐co‐3‐methacryloxypropyl trimethoxysilane (PMSi90) polymers, or photoinduced radical grafting of PMPC and also the effects of the surface properties on the durability of cross‐linked polyethylene (CLPE) for artificial joints. The PMPC‐grafted CLPE has an extremely low and stable coefficient of dynamic friction and volumetric wear as compared to the untreated CLPE, PMB30‐coated CLPE, and PMSi90‐coated CLPE. It is concluded that the photoinduced radical graft polymerization of MPC is the best method to retain the benefits of the MPC polymer used in artificial joints under variable and multidirectional loads for long periods with strong bonding between the MPC polymer and the CLPE surface, and also to retain the high mobility of the MPC polymer. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Frizzled‐1 is involved in the neuroprotective effect of Wnt3a against Aβ oligomers
Authors: Chacón Marcelo A. , Varela‐Nallar Lorena , Inestrosa Nibaldo C.
Published: June 2008

The activation of the canonical Wnt signaling pathway protects hippocampal neurons against the toxicity of Alzheimer's amyloid‐β‐peptide (Aβ), however, the role played by the Wnt receptors Frizzleds, has not been studied. We report here that Frizzled‐1 mediates the activation of the canonical Wnt/β‐catenin pathway by Wnt3a in PC12 cells. In addition, the protective effect of Wnt3a against the toxicity of Aβ oligomers was modulated by Frizzled‐1 expression levels in both PC12 cells and hippocampal neurons. Over‐expression of Frizzled‐1 significantly increased cell survival induced by Wnt3a and diminished caspase‐3 activation, while knocking‐down Frizzled‐1 expression by antisense oligonucleotides decreased the Wnt3a protection. Over‐expression of wild‐type β‐catenin, but not a transcriptionally inactive mutated version, prevented the toxicity of Aβ suggesting that the transcription of Wnt target genes may be involved in these events. This was confirmed by co‐transfecting both Frizzled‐1 and the inactive form of β‐catenin, which does not elicited protection levels similar to those showed with endogenous β‐catenin. Our results indicate that Wnt3a protects from Aβ‐oligomers toxicity by activating the canonical Wnt signaling pathway through the Frizzled‐1 receptor, suggesting a therapeutic potential for this signaling pathway in the treatment of Alzheimer's disease. J. Cell. Physiol. 217: 215–227, 2008. © 2008 Wiley‐Liss, Inc.
Lipopolysaccharide plus hypoxia and reoxygenation synergistically reduce electrical coupling between microvascular endothelial cells by dephosphorylating Connexin40
Authors: Bolon Michael L. , Peng Tianqing , Kidder Gerald M. , Tyml Karel
Published: June 2008

We showed that lipopolysaccharide (LPS) or hypoxia and reoxygenation (H/R) decreases electrical coupling between microvascular endothelial cells by targeting the gap junction protein connexin40 (Cx40), tyrosine kinase‐, ERK1/2‐, and PKA‐dependently. Since LPS can compromise microvascular blood flow, resulting in micro‐regional H/R, the concurrent LPS + H/R could reduce coupling to a much greater extent than LPS or H/R alone. We examined this possibility in a model of cultured microvascular endothelial cells (mouse skeletal muscle origin) in terms of electrical coupling and the phosphorylation status of Cx40. To assess coupling, we measured the spread of electrical current injected into the cell monolayer and computed the intercellular resistance as an inversed measure of coupling. In wild type cells, but not in Cx40 null cells, concurrent LPS + H/R synergistically increased resistance by ∼270%, well above the level observed for LPS or H/R alone. Cx37 and Cx43 protein expression did not differ between Cx40 null and wild type cells. LPS + H/R increased resistance PKA‐ and PKC‐dependently. By immunoprecipitating Cx40, we found that LPS + H/R reduced serine phosphorylation to a much greater degree than that observed for LPS or H/R alone. Further, PKA‐specific, but not PKC‐specific serine phosphorylation of Cx40 was also significantly reduced following LPS + H/R. This reduction was prevented by tyrosine kinase and MEK1/2 inhibition, by PKA activation, and mimicked in control cells by PKA inhibition. We conclude that LPS + H/R initiates tyrosine kinase‐ and ERK1/2‐sensitive signaling that synergistically reduces inter‐endothelial electrical coupling by dephosphorylating PKA‐specific serine residues of Cx40. J. Cell. Physiol. 217: 350–359, 2008. © 2008 Wiley‐Liss, Inc.
Mixing time in an agitated multi‐lamp cylindrical photoreactor using electrical resistance tomography
Authors: Zhao Zhen Fang , Mehrvar Mehrab , Ein‐Mozaffari Farhad
Published: June 2008

BACKGROUND: There is scarce information on the application of electrical resistance tomography (ERT) in UV photoreactors, in which mixing and mass transfer are important. Therefore, the feasibility of an ERT system in an agitated multi‐lamp UV photoreactor was investigated to monitor the mixing process.

RESULTS: The locations of the UV tubes had a significant impact on the mixing time, particularly at the lower impeller speeds (45 and 150 rpm). Also, at the higher impeller speeds (250, 350, and 500 rpm) and the same radial position (r), changing the angle θ from 15 to 45°, resulted in only a slight variation of the mixing time. Finally, the maximum mixing time occurred when UV tubes were positioned at r = 13 cm (r/R = 0.68) and θ = 0°, while minimum mixing time occurred at location r = 16 cm (r/R = 0.83) and θ = 45°.

CONCLUSION: The experimental results demonstrated the feasibility of the ERT system to monitor the mixing process in the UV photoreactor. The ERT results also indicated that the locations of the UV tubes had a significant effect on the mixing performance of the photoreactor. Furthermore, the mixing time varied inversely with the rotational speed, and this effect was more pronounced at lower speeds. Copyright © 2008 Society of Chemical Industry
Comparative study of the volatile composition in wines obtained from traditional vinification and from the Ganimede method
Authors: Garde‐Cerdán Teresa , Jarauta Idoia , Salinas M Rosario , Ancín‐Azpilicueta Carmen
Published: June 2008

BACKGROUND: This study compares the volatile composition between wines obtained from vinification carried out by the traditional method or using a new method of vinification (so‐called Ganimede). For this, Shiraz, Merlot and Cabernet Sauvignon musts were fermented by both vinification methods.

RESULTS: The volatile compounds that were above their threshold of perception in the wines were practically the same, irrespective of the vinification method used. Most of the compounds studied did not present significant differences in their concentrations between the wines obtained from the traditional and the new vinification methods. When there were significant differences, the concentration of alcohols and acids was higher in the wines vinificated by the traditional method rather than in the wines vinificated by the Ganimede method, whereas for esters, the concentration in the wines depended on the grape variety.

CONCLUSION: The Ganimede method favoured polyphenol extraction without greatly affecting the studied volatile composition of the wines. Copyright © 2008 Society of Chemical Industry
Chemical composition, organic matter digestibility and fatty acid content of linseed (Linum usitatissimum L.) harvested at five stages of growth
Authors: Peiretti Pier Giorgio , Meineri Giorgia
Published: June 2008

BAKGROUND: The quality of forages changes according to the morphological stage and it is important to define the nutritive characteristics and fatty acid (FA) content of the crop during growth. That allows a choice of cutting time in order to optimise the uilisation of the forages and to identify new sources of polyunsatured fatty acids (PUFAs) for ruminants. Our aim was to study changes in the chemical composition, in vitro organic matter digestibility, gross energy, and FA content, of linseed (Linum usitatissimum L.) samples collected from the stem extension to the mature seed stage.

RESULTS: The development of linseed quality during growth is characterised by a progressive increase in the fibrous fractions and a decrease in crude protein, ether extract, ash, and in vitro organic matter digestibility (IVOMD). The FA profiles in the plant were characterised by four dominant FAs: palmitic acid (PA, 16:0), stearic acid (SA, 18:0), linoleic acid (LA, 18:2n‐6) and α‐linolenic acid (ALA, 18:3n‐3). PA, SA and LA increased from the visible bud stage to mature seed stage, while ALA decreased, consequently the n‐6/n‐3 polyunsaturated FA ratio of the plant increased during growth.

CONCLUSION: The chemical composition and FA profile of linseed is closely connected to the development of the plant. Forage with a good nutritive value and with a content of unsaturated FA that is suitable for herbivorous feeding is still obtained by harvesting green linseed at the brown capsule stage. Copyright © 2008 Society of Chemical Industry
Variability in the content of soluble sugars and cell wall polysaccharides in red‐ripe cherry and high‐pigment tomato cultivars
Authors: Lenucci Marcello Salvatore , Leucci Maria Rosaria , Piro Gabriella , Dalessandro Giuseppe
Published: June 2008

BACKGROUND: Soluble sugars and cell wall polysaccharides are well known for contributing to a range of ‘quality’ characteristics of fresh vegetables such as flavour, texture and healthy properties. Red‐ripe berries of 14 cultivars of cherry tomatoes and four cultivars of high‐pigment tomato hybrids, cultivated in the south of Italy, were analysed for their content of these important qualitative parameters.

RESULTS: Sakura appeared to be the cultivar with the highest amount of soluble sugars (53 g kg−1 fresh weight (f.w.)), mainly glucose and fructose, and, hence the ‘sweetest’ among cherry tomatoes. High‐pigment tomatoes, especially HLY02 and HLY13, showed a soluble sugar content much lower than cherry tomatoes, as expected for industrial, normal‐size tomatoes. Variations in the fructose/glucose ratio, of between 0.68 and 1.48, were evidenced among the different tomato cultivars. Cell wall polysaccharides isolated from whole fresh red‐ripe berries of each cultivar were analysed chemically. The amount of matrix polysaccharides (0.9–3.4 g kg−1 f.w.) and cellulose (0.16–1.86 g kg−1 f.w.), as well as their glycosidic composition, showed significant differences among the different cultivars. Cellulose to matrix polysaccharide ratio was highly variable and ranged between 0.06–1.44 and 0.17–0.77 in cherry and high‐pigment tomato cultivars, respectively.

CONCLUSION: The differences evidenced in the total soluble sugar and cell wall polysaccharide composition, not only among different types of tomatoes but also different cultivars within the same typology, may play a fundamental role in the quality of tomatoes and deserve further investigations. Copyright © 2008 Society of Chemical Industry
Is gastrectomy mandatory for all residual or recurrent gastric cancer following endoscopic resection? a large‐scale Korean multi‐center study
Authors: Song Kyo Young , Hyung Woo Jin , Kim Hyung Ho , Han Sang Uk , Cho Gyu Seok , Ryu Seung Wan , Lee Hyuk Joon , Kim Min Chan
Published: June 2008

Background and Objectives

To clarify optimal treatment guidelines for residual or local recurrence after endoscopic resection (ER).

Methods

Eighty‐six patients underwent gastrectomy due to incomplete ER and local recurrence after ER. The pathological findings of ER and gastrectomy specimens were analyzed.

Results

The cause of gastrectomy was categorized into five groups; submucosal (sm) invasion without margin involvement, positive margin, margin not evaluable, high risk of lymph node metastasis and local recurrence after ER. According to the pathological findings of gastrectomy specimens, remnant cancer and lymph node metastases were found in 56 (65.1%) and in 5 patients (5.8%), respectively. At 10 gastrectomy specimens which were sm invasion without margin involvement, the scattered residual cancer cells were found around the ulcer scar in 2 (20%) patients. In 11 of 44 margin involvement specimens, no residual cancer or lymph node metastasis was found. In patients with local recurrence, mean duration from ER to surgery was 14.8 months, and 19% of patients were found to have sm or deeper depth of invasion.

Conclusion

Gastrectomy with lymph node dissection should be performed in patients with sm invasion with or without margin involvement. However, minimal approach other than gastrectomy could further be applied to selected patients. J. Surg. Oncol. 2008;98:6–10. © 2008 Wiley‐Liss, Inc.
Cellular and peritoneal immune response after radical laparoscopy‐assisted and open gastrectomy for gastric cancer
Authors: Jung Il‐Kwon , Kim Min‐Chan , Kim Kyeong‐Hee , Kwak Jong‐Young , Jung Ghap‐Joong , Kim Hyung‐Ho
Published: June 2008

Background and objectives

The aim of this study was to assess cellular and peritoneal immune responses after radical laparoscopic surgery in gastric cancer.

Methods

Peripheral heparinized plasma and plain serum tube samples were collected preoperatively, and at 2 hr, 1 day, and 4 days postoperatively for analysis o; white blood cells, total lymphocytes, T‐helper lymphocytes, T‐suppressor lymphocytes, B‐lymphocytes, natural killer cells, plasma C‐reactive protein and serum amyloid‐A. Twenty‐four hours peritoneal fluid collection was performed on days 1 and 4 for TNF‐α, IL‐6, and IL‐10 analysis.

Results

No statistical differences were observed between the two groups with respect to immunocompetent cell counts. The serum levels of plasma CRP and SAA gradually increased significantly with time in both groups, but these temporal increases were lower in the LADG group (CRP; P = 0.03, SAA; P = 0.01). Peritoneal TNF‐α levels in the CODG group at 4 days postoperatively were significantly higher than at day 1, but remained almost unchanged in the LADG group, and this difference was significant (P = 0.02).

Conclusion

Because of its association with reduced peritoneal immune activity, laparoscopic surgery for advanced gastric cancer may require careful consideration in practice. Additional, larger prospective multicenter trials are required before a consensus can be reached. J. Surg. Oncol. 2008;98:54–59. © 2008 Wiley‐Liss, Inc.
Electrolytic ablation is as effective as radiofrequency ablation in the treatment of artificial liver metastases in a pig model
Authors: Hinz Sebastian , Egberts Jan‐Hendrik , Pauser Ursula , Schafmayer Clemens , Fändrich Fred , Tepel Jürgen
Published: June 2008

Background

The best treatment option for liver metastases is complete surgical resection. Unfortunately, at the time of diagnosis, not all patients are candidates for complete resection. Electrolytic therapy (ECT) is a novel non‐thermal method of tissue destruction. We evaluated its safety and effectiveness in comparison with radiofrequency ablation (RFA).

Methods

Tumor mimics were created by injecting a gel into the pig liver. The volume of the lesions was measured by ultrasound before treatment. The tumor mimics were treated with either RFA or electrolytic ablation. 48 h after treatment the liver was fixed in formalin and subjected to histological examination.

Results

Histological investigation confirmed that all lesions were completely surrounded by necrosis after treatment with either ECT or RFA. Two different types of necrosis were identified. After RFA the cell membranes disappeared but the nuclei were still intact, whereas after ECT these structures were completely disrupted. After ECT the necrosis was often surrounded by infiltrating lymphocytes. This inflammatory reaction was not apparent after RFA.

Conclusion

ECT produced predictable and reproducible necrosis in pig livers and was as effective as RFA at destroying a defined target lesion. A local inflammatory reaction after ECT may favour the development of a systemic immune response. Our results indicate that ECT is an alternative treatment option for irresectable liver metastases. J. Surg. Oncol. 2008;98:135–138. © 2008 Wiley‐Liss, Inc.
Elevated p21 expression is associated with poor prognosis of rectal stromal tumors after resection
Authors: Hu Tsung‐Hui , Tai Ming‐Hong , Chuah Seng‐Kee , Chen Hong‐Hwa , Lin Jui‐Wei , Huang Hsuan‐Ying , Chou Yeh‐Pin , Yi Li‐Na , Kuo Chung‐Mou , Changchien Chi‐Sin
Published: June 2008

Background and Objectives

The pathogenic role of alteration of cell‐cycle proteins in rectal stromal tumors (GISTs) remains unclear. This study aimed to elucidate the prognostic role of p21 to compare with p53, PCNA, and Ki‐67 in rectal GISTs.

Methods

Forty‐nine surgically resected CD117 (+) rectal GISTs were enrolled from 1986 to 2006. Immunohistochemical studies were performed with antibodies of p21, p53, PCNA, and Ki‐67.

Results

The labeling index (LI) of immunoreactivities range from 0% to 65% for p53, 0% to 60% for p21, 0% to 67% for Ki‐67, and 30% to 93% for PCNA. LI of four markers were positively correlated (P < 0.05). LI of four markers were also positively correlated with tumor mitosis and tumor size (P < 0.05). Tumors with high p53, p21, or Ki‐67 LI were associated with increased NIH risk, non‐spindle cell type, and high cell pleomorphism (P < 0.05). Survival analyses demonstrated that large tumor size (P = 0.012), high tumor mitosis (P < 0.001), increased NIH risk (P = 0.003), high cell pleomorphism (P = 0.004), high p53 LI (P = 0.005), high p21 LI (P = 0.009), high PCNA LI (P = 0.001), and high Ki‐67 LI (P = 0.042) were poor prognostic factors for disease‐specific survival.

Conclusions

Elevated p21 expression is associated with poor prognosis of rectal stromal tumors after resection. J. Surg. Oncol. 2008;98:117–123. © 2008 Wiley‐Liss, Inc.
Macromol. Biosci. 6/2008
Authors: Mark Sonny S. , Stolper Samuel I. , Baratti Carla , Park Jason Y. , Taku Maria A. , Santiago‐Avilés Jorge J. , Kricka Larry J.
Published: June 2008

Cover: The cover shows the bioconjugation and characterization of aqueous suspendible polymer nanostructures prepared by simple microtome processing of electrospun nylon 6 nanofibers. Mechanically shortened, aqueous dispersed electrospun polymer nanofibers have potential application as enzyme scaffolds in chemiluminescent‐based assay systems. Further details can be found in the article by S. S. Mark,* S. I. Stolper, C. Baratti, J. Y. Park, M. A. Taku, J. J. Santiago‐Avilés, and L. J. Kricka on page 484.
Effect of fluctuation and modification on microstructure and impact toughness of 20 wt.% Cr hypereutectic white cast iron. Einfluss durch Partikelzugaben und Modifikationen auf die Mikrostruktur und die Kerbschlagzähigkeit von übereutektischem weißen Gusseisen mit 20 Gew.‐% Cr
Authors: Zhi X. , Xing J. , Fu H. , Gao Y.
Published: June 2008

In the present study, Fe‐Cr‐C hypereutectic high chromium white cast iron were prepared from industry‐grade materials and subjected to the treatment of modification using Fe‐Si‐RE alloy, aluminum and a self‐made intermediate alloy, fluctuation (ferroalloy powder), and the combination of the fluctuation and the modification respectively. The structures of the treated alloy were investigated by means of the optical microscopy (OM). The impact toughness of the specimens was also examined. The fractographs of the samples were examined by scanning electron microscopy (SEM). The results showed that, with the addition of fluctuation or modifying agents, the primary carbides were refined and the impact toughness of the alloys was improved, especially with the combination of them.
Effect of the load location along the involute curve of spur gears on the applied stress at the fillet radius
Authors: Khoshnaw F. M. , Ahmed N. M.
Published: June 2008

In this study, attempts are carried out to determine the amount of stress at the fillet radius region of spur gears when the applied load location changes, along the involute curve, from the top surface to the bottom. For this purpose the photoelastic method and numerical MSC/NASTRAN software are used. The gears with pressure angle (ϕ) 20o, and 25o were prepared from photoelastic material type PLM‐4B in this study. Practical calibration is used to determine the fringe order value of this material. Four different modules (m); 6, 10, 14, and 20 mm were prepared for two different numbers of teeth (N); 18 and 26, with different face widths (B1, B2, B3); 10, 17, 25.4 mm respectively. Four load values were applied on each tooth at five to six different load locations along the involutes curve profile. In order to accomplish the comparison between the results for different methods, the same sample dimensions and parameters were prepared again for the MSC/NASTRAN software.

The results showed that the maximum applied stress at the fillet radius occur when the applied load location is on the top land of a tooth, and then that amount is decreased when the applied load positions change toward the bottom land. The results of the NASTRAN method showed that the applied stress at the fillet radius would be minimum when the loading point locates between the pitch circle and dedendum circle, in particular around 1.5 times module (1.5 m) of the total tooth height which equals 2.25 module, and then the applied stresses are increased again. However, in the photoelastic method the applied stresses were decreased continuously to the bottom land. The reasons behind such results can be attributed to the type of failure theories that can be used in NASTRAN software for characterization the applied stresses, i.e. considering types of applied stresses into account, such as bending, direct compressive, and shear stresses. Moreover, in order to compare the applied stress values at fillet regions, obtained by theoretical and practical approaches, four different standard mathematical equations are used for stress calculation at fillet radius of spur gears to show the difference of the parameters and variables that can affect the applied stress results.