bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct optimal growth analysis for timesteppers
Authors: Barkley D. , Blackburn H. M. , Sherwin S. J. 
Published: June 2008

AbstractMethods are described for transient growth analysis of flows with arbitrary geometric complexity, where in particular the flow is not required to vary slowly in the streamwise direction. Emphasis is on capturing the global effects arising from localized convective stability in streamwise‐varying flows. The methods employ the ‘timestepper's approach’ in which a nonlinear Navier–Stokes code is modified to provide evolution operators for both the forward and adjoint linearized equations. First, the underlying mathematical treatment in primitive flow variables is presented. Then, details are given for the inner level code modifications and outer level eigenvalue and SVD algorithms in the timestepper's approach. Finally, some examples are shown and guidance provided on practical aspects of this type of large‐scale stability analysis. Copyright © 2008 John Wiley & Sons, Ltd.
Numerical study of magnetohydrodynamic laminar flow separation in a channel with smooth expansion
Authors: Maikap T. K. , Mahapatra T. R. , Niyogi P. , Ghosh A. K. 
Published: June 2008

AbstractThe flow of an electrically conducting incompressible viscous fluid in a plane channel with smooth expansion in the presence of a uniform transverse magnetic field has been analysed. A solution technique for the governing magnetohydrodynamic equations in primitive variable formulation has been developed. A co‐ordinate transformation has been employed to map the infinite irregular domain into a finite regular computational domain. The governing equations are discretized using finite‐difference approximations in staggered grid. Pressure Poisson equation and pressure correction formulae are derived and solved numerically. It is found that with increase in the magnetic field, the size of the flow separation zone diminishes and for sufficiently large magnetic field, the separation zone disappears completely. The peak u‐velocity decreases with increase in the magnetic field. It is also found that the asymmetric flow in a symmetric geometry, which occurs at moderate Reynolds numbers, becomes symmetric with sufficient increase in the transverse magnetic field. Thus, a transverse magnetic field of suitable strength has a stabilizing effect in controlling flow separation, as also in delaying the transition to turbulence. Copyright © 2008 John Wiley & Sons, Ltd.
Short‐term prediction of motorway travel time using ANPR and loop data
Authors: Li Yanying 
Published: May 2008

AbstractTravel time is a good operational measure of the effectiveness of transportation systems. The ability to accurately predict motorway and arterial travel times is a critical component for many intelligent transportation systems (ITS) applications. Advanced traffic data collection systems using inductive loop detectors and video cameras have been installed, particularly for motorway networks. An inductive loop can provide traffic flow at its location. Video cameras with image‐processing software, e.g. Automatic Number Plate Recognition (ANPR) software, are able to provide travel time of a road section. This research developed a dynamic linear model (DLM) model to forecast short‐term travel time using both loop and ANPR data. The DLM approach was tested on three motorway sections in southern England. Overall, the model produced good prediction results, albeit large prediction errors occurred at congested traffic conditions due to the dynamic nature of traffic. This result indicated advantages of use of the both data sources. Copyright © 2008 John Wiley & Sons, Ltd.
Insight into Proton Conduction of Immobilised Imidazole Systems Via Simulations and Impedance Spectroscopy
Authors: Cavalcanti W. L. , Marschall R. , Tölle P. , Köhler C. , Wark M. , Frauenheim T. 
Published: June 2008

AbstractThe proton conduction in immobilised imidazole systems has been investigated in order to support the design of new membrane materials for polymer electrolyte membrane fuel cells (PEMFC). In the experimental part of this work, proton conductivities are measured via impedance spectroscopy. The simulation and modelling are performed combining molecular dynamics simulations and energy barrier calculations; the analysis is done via the proton jump energy barrier, collision ratio and radial distribution function. The dependence of the proton mobility on the temperature, spacer length and the density of conducting groups per area is presented. Donors and acceptors groups approach to each other within a distance from 2.8 to 3 Å where the energy barrier for a proton transfer is very low, which favours the proton jump under the studied conditions. The proton conductivity increases with increase in the spacer length. The simulation results are in good agreement with the proton conductivities presented.
Blocking Effect in High Purity Nanostructured Cubic Zirconia Ceramics
Authors: Boulfrad S. , Djurado E. , Dessemond L. 
Published: June 2008

AbstractElectrical properties of grain boundaries, free of any secondary phases, have been investigated in cubic nanostructured zirconia ceramics. Pure 8YSZ powders were synthesised by spray pyrolysis process. These powders were used to perform dense nanostructured ceramics using two compaction techniques: cold isostatic pressing (CIP) and hot uniaxial pressing (HUP) in an oxidising atmosphere. Grain sizes ranging from 25 to 242 nm and relative densities from 93 up to 98% were obtained. Electrical contribution of the bulk and the blocking effect due to grain boundaries were determined by impedance spectroscopy and analysed according to the brick layer model. The additional blocking effect is a decreasing function of the grain size but its magnitude reaches a plateau quite insensitive to the grain size below 100 nm. This indicates that the recorded electrical contribution originates from an intrinsic effect. This can be related to a dominant electrical contribution of space charge layers located at the grain boundaries area of nanoscale grain sizes.
A fragile site within the HPC1 region at 1q25.3 affecting RGS16, RGSL1, and RGSL2 in human breast carcinomas
Authors: Wiechec Emilia , Overgaard Jens , Hansen Lise Lotte 
Published: June 2008

AbstractGenomic alterations affecting chromosome arm 1q are considered to be an early event in breast carcinogenesis and are correlated with good prognosis for the patients. In the search for new breast cancer susceptibility genes, we focused on three genes from the Regulator of G protein Signaling family clustered on 1q25.3 within the HPC1 region. RGS16, RGSL2, and RGSL1 encode proteins interacting with G proteins and accelerating termination of the G protein signaling. To evaluate the implication of these genes in somatic breast cancer, we analyzed a 154‐kb segment at 1q25.3 using allelic imbalance (AI) mapping. A panel of 222 patients diagnosed with primary breast cancer was analyzed using newly identified, intragenic short tandem repeats (STRs). A high rate of AI (>50%) was found across the region and led to the identification of internal chromosomal breakpoints. A detailed mapping of the breakpoints revealed intragenic microdeletions affecting the coding regions of RGSL2, RGSL1, and the regulatory region of RGS16. The promoter region of RGS16 was found to be methylated in 10% of the tumors. A decrease in the RGS16 expression was found in tumors with chromosomal breakpoints, AI, and aberrant methylation. We found a significant association between AI of RGSL2 and localized disease, which correlated with good prognosis for patients with breast cancer. In conclusion, we found the 1q25.3 region to be highly unstable in breast tumors comprising a cluster of chromosomal breakpoints, intragenic microdeletions, frequent allelic imbalance correlating with long metastasis‐free survival, and RGS16 promoter methylation affecting the protein expression. © 2008 Wiley‐Liss, Inc.
The first functional study of MLH3 mutations found in cancer patients
Authors: Korhonen Mari K. , Vuorenmaa Elina , Nyström Minna 
Published: June 2008

AbstractThe MLH3 gene is one of the five mismatch repair (MMR) genes associated with hereditary nonpolyposis colorectal cancer (HNPCC). Eighteen different inherited MLH3 mutations have been reported as pathogenic in an international mutation database. In several cases, a mutation was found in a patient without a family history suggestive of inherited cancer susceptibility. In some cases, a similar mutation was also found in sporadic patients and/or healthy controls. Four patients carried an MLH3 mutation together with another inherited MMR gene variation. No functional analyses have been performed to assess the pathogenicity of these 18 mutations. MLH3 has been assumed to be less important in MMR than the other HNPCC susceptibility genes MSH2, MSH6, MLH1, and PMS2, and accordingly a low‐risk gene for colorectal cancer (CRC). To assess the significance of the inherited sequence variations in MLH3, we functionally characterized seven missense mutations (Q24E, R647C, S817G, G933C, W1276R, A1394T, E1451K) scattered throughout the MLH3 polypeptide. The mutations were found in CRC or endometrial cancer patients and reported as pathogenic. Our study showed that the seven mutated MLH3 proteins, in complex with their counterpart MLH1 (MutLγ), repaired mismatches as the wild type MutLγ but worse than a heterodimer of MLH1 and PMS2 (MutLα). The results confirm that MutLγ is a less efficient MMR complex than MutLα and show that the MLH3 mutations alone do not interfere with MMR. Further studies are needed to evaluate the pathogenicity of MLH3 mutations in compound with other MMR mutations. © 2008 Wiley‐Liss, Inc.
Shallow Tunnelling in Soft Ground – Influence of the Chosen Support System on the System Behaviour
Authors: Krenn Florian , Galler Robert , Junker Arne , Stacherl Bernhard 
Published: June 2008

AbstractThe Brenner corridor is part of the new North‐South European rail link for high‐speed trains and combined transport services connecting Munich in Germany and Verona in Italy. As the Lower Inn Valley in Austria is narrow and densely populated with towns lined up along the Inn river, the characteristics of the alignment of the new route is that 83 % of the 41 km long Unterinntal route will run underground. The new route includes the tunnel Vomp‐Terfens which is about 8 km long and is constructed through different types of ground – competent rock and soft ground (quaternary sediments such as ground moraine and gravel). The applied support measures varied from 150 mm steelfibre reinforced shotcrete in the hard rock sections (dolomite) to 300 mm reinforced shotcrete lining with advance support consisting of double layered pipe roof umbrella in the sections with low overburden and layers of potentially unstable gravel.Two advance support systems were used in similar ground conditions – forepoling with spiles and a pipe roof umbrella support. This paper deals with conclusions drawn from the monitoring results in the tunnel, on the surface and from the evaluation of a horizontal inclinometer which was installed in one of the pipe roofs. The main objective pursued by the authors is the comparison of the mode of loading and its effect on the overall system behaviour, not an evaluation of the “advantages” or “disadvantages” of the two different types of advance support systems. In the authors' opinion there are always “two plus” possibilities to solve a tunnelling task – the chosen solution depends on a variety of factors such as the given geotechnical boundary conditions, the adopted safety level and economic considerations.
Hydrologic history of the Mississippi and Lower Missouri Rivers based upon a refined specific‐gauge approach
Authors: Jemberie Abebe A. , Pinter Nicholas , Remo Jonathan W. F. 
Published: May 2008

AbstractA refined specific‐gauge approach was developed to quantify changes over time in hydrological response on 3260 km of the Mississippi River system using long‐term data observed at 67 hydrologic measurement stations. Of these stations, 49 were unrated (stage‐only) stations, for which over 2 000 000 ‘synthetic discharges’ were generated based on measured discharge values at nearby rated stations. The addition of these synthetic discharges nearly tripled the number of stations in the study area for which specific‐gauge analysis could be performed. In order to maintain spatial homogeneity across such a broad study area, discharges were normalized to multiples of mean daily flow (MDF). Specific‐gauge analysis calculates stage changes over time for invariant discharge conditions. Two discharges were analysed: low‐flow and flood conditions at each station. In order to avoid the large errors associated with extrapolation of annual rating curves, a new ‘enhanced interpolation’ technique was developed that calculates continuous specific‐stage time series, even for rare discharges. Thus enhanced, specific‐gauge analysis is a useful reconnaissance tool for detecting geomorphic and hydrologic trends over time. Results show that on the Middle Mississippi River and Lower Missouri River, flood stages increased at all stations in spite of widespread incision of the river bed. On the Lower Mississippi River, both low‐flow and flood stages decreased, mainly the result of artificial meander cutoffs in the late 1920s and 1930s, except downstream of Natchez, MS, where net aggradation was observed. On the Upper Mississippi River, the specific‐gauge trends were dominated by emplacement of navigational dams and impoundment of slackwater pools. On all four river reaches, these results document hydrologic responses to the different engineering toolkits used on the different portions of the Mississippi River system during the past 75–150 years. Copyright © 2008 John Wiley & Sons, Ltd.
Hypoxia‐inducible factor 1 and cancer pathogenesis
Authors: Semenza Gregg L. 
Published: May 2008

AbstractHypoxia‐inducible factor 1 (HIF‐1) is a transcriptional activator that mediates adaptive responses to hypoxia. HIF‐1 activity is increased in the majority of human cancers as a result of genetic alterations and intratumoral hypoxia. HIF‐1 activates the transcription of genes that increase O2 availability by stimulating angiogenesis or that reprogram cellular metabolism to adapt to reduced O2 availability. Proof of principle studies in mouse models suggests that inhibition of HIF‐1 activity may have therapeutic effects, especially in combination with other anticancer drugs. © 2008 IUBMB IUBMB Life, 60(9): 591–597, 2008
Metabolic regulation by lactate
Authors: Sola‐Penna Mauro 
Published: May 2008

AbstractFor more than a century, the metabolic role of lactate has intrigued physiologists and biochemists. Yet, for the first half of the last century lactate had been designated as a waste product, and assigned no additional significance besides its controversial role in muscle fatigue. The decline of the lactate hypothesis for the onset of muscle fatigue and the defining of some modulatory properties attributed to lactate have increased the interest on this molecule. The present critical review aimed at evaluating some recent publications concerned with unveiling the regulatory actions of lactate in cellular function. Lactate has been described to modulate enzymes catalytic properties to affect hormonal release and responsiveness, and to control body homeostasis. Moreover, these properties are directly related to the genesis and the sustainability of pathological conditions, such as diabetes and cancer. In the end, we concluded that lactate should not be regarded as simply an anaerobic metabolite, but should be considered as a regulatory molecule that modulates the integration of metabolism. © 2008 IUBMB IUBMB Life, 60(9): 605–608, 2008
The estimation of utility‐consistent labor supply models by means of simulated scores
Authors: Bloemen Hans G. , Kapteyn Arie 
Published: June 2008

AbstractWe consider a utility‐consistent static labor supply model with flexible preferences and a nonlinear and possibly non‐convex budget set. Stochastic error terms are introduced to represent optimization and reporting errors, stochastic preferences, and heterogeneity in wages. Coherency conditions on the parameters and the support of error distributions are imposed for all observations. The complexity of the model makes it impossible to write down the probability of participation. Hence we use simulation techniques in the estimation. We compare our approach with various simpler alternatives proposed in the literature. Both in Monte Carlo experiments and for real data the various estimation methods yield very different results. Copyright © 2008 John Wiley & Sons, Ltd.
Biocompatibility of total joint replacements: A review
Authors: Goodman Stuart B. , Gómez Barrena Enrique , Takagi Michiaki , Konttinen Yrjo T. 
Published: May 2008

AbstractTotal joint replacement is one of the most clinically successful, cost‐effective surgical procedures. These operations have been shown to improve pain, function and mobility in patients with end‐stage arthritis. However, joint replacements that will allow full, unrestricted, high impact activities and last the patient's lifetime have not yet been devised. This is due to biocompatibility issues related to material science, biomechanics, and host responses. In this review, three issues that are highly pertinent to biocompatibility of joint replacements are examined. These topics include how implants initially osseointegrate within bone, potential adverse effects of byproducts of wear that can lead to aseptic loosening and perprosthetic osteolysis, and the potential for new bearing surfaces to extend the lifetime of implants. A clear understanding of these important issues will facilitate the development of novel strategies to improve the longevity and function of implants for joint replacement in the future. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Protein recognition onto silica particles using chitosan as intermedium substrate
Authors: Xia Yong‐Qing , Guo Tian‐Ying , Zhao Hai‐Li , Song Mou‐Dao , Zhang Bang‐Hua , Zhang Bao‐Long 
Published: May 2008

AbstractA novel molecular imprinting method was used to prepare twice‐coated silica particles with specific recognition sites for hemoglobin. Chitosan was used as an intermedium to be coated on silica particles via phase inversion process, and the abundance of exposed amine groups (NH2) were active sites for introducing aldehyde groups. After hemoglobin was covalently immobilized by forming imine bonds with the aldehyde groups, acrylamide was then polymerized onto chitosan‐coated silica particles to form the recognition sites. The obtained hemoglobin imprinted [molecularly imprinted polymer (MIP)] beads were characterized by FTIR spectroscopy, thermogravimetric analysis (TG), and scanning electron microscopy (SEM). The MIP particles exhibited selectively adsorption for the imprinted protein compared to the nonselectively adsorption for most of proteins of the nonimprinted (NIP) beads. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Novel poly(HEMA‐co‐METAC)/alginate semi‐interpenetrating hydrogels for biomedical applications: Synthesis and characterization
Authors: La Gatta Annalisa , Schiraldi Chiara , Esposito Annaclaudia , D'Agostino Antonella , De Rosa Alfredo 
Published: May 2008

AbstractNovel p(HEMA‐co‐METAC)/alginate semi‐interpenetrating hydrogels (semi‐IPNs) were developed in the attempt to improve poly(hydroxyethylmethacrylate) biological response, extending its applications in the biomedical field. Materials with different alginate contents were synthesized by copolymerization of 2‐hydroxyethylmethacrylate and 2‐methacryloxy ethyltrimethyl ammonium chloride monomers in the presence of aqueous solutions of alginate and characterized with respect to p(HEMA‐co‐METAC) synthesized in the presence of water. Swelling studies in water revealed high values of water uptake (>100%) with marked differences in the swelling degree at increasing polysaccharide content. The effect of ionic strength and of pH on the swelling behavior of hydrogels was also investigated. Higher ionic strengths resulted in a minor swelling degree accordingly with hydrogels polyelectrolyte nature. The introduction of the natural ionizable polysaccharide into the network made the semi‐IPNs swelling depending on pH values of the solutions. A biological characterization was performed in terms of protein absorption on hydrogel surfaces, cytotoxicity (ISO 10993‐5) and cell adhesion and proliferation studies using both murine 3T3 and human fibroblasts. Hydrogels proved noncytotoxic; moreover, semi‐IPN surfaces allowed cell attachment and proliferation, thus supporting their potential biomedical use. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Abrogation of the inflammatory response in LPS‐stimulated RAW 264.7 murine macrophages by Zn‐ and Cu‐doped bioactive sol–gel glasses
Authors: Varmette Elizabeth A. , Nowalk Jessica R. , Flick Lisa M. , Hall Matthew M. 
Published: May 2008

AbstractThe attenuation of an in vitro inflammatory response in RAW 264.7 murine macrophages stimulated with lipopolysaccharide (LPS) endotoxin was tested using sol–gel‐derived bioactive glasses. Three general types of sol–gel‐derived samples were evaluated: 58S, zinc‐containing glasses, and copper‐containing glasses. Distinct experimental procedures were used to test the potential of bioactive glasses to attenuate the inflammatory response in three situations: (1) therapeutically following LPS stimulation, (2) prophylactically before LPS stimulation of macrophages, and (3) indirectly via the glass dissolution products after stimulation with LPS. A sandwich enzyme‐linked immunosorbent assay (ELISA) was used to monitor the concentration of tumor necrosis factor‐α (TNF‐α) secreted by macrophage cells. The strongest reduction in TNF‐α concentration was observed when macrophage cells were first incubated with bioactive glass powder and then stimulated with LPS. This suggests a possible prophylactic application of these bioactive glasses for the prevention of inflammation. The 58S glass was capable of reducing the expression of TNF‐α by macrophages, although the zinc‐ and copper‐containing were more effective at suppressing the inflammatory response. The additional benefit of using zinc‐ and copper‐doped bioactive glasses may be explained by the direct interactions of zinc and copper ions in key regulatory pathways for the inflammation response. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Intracerebral microinjection of stannous 2‐ethylhexanoate affects dopamine turnover in cerebral cortex and locomotor activity in rats
Authors: Yamada Takashi , Jung Duk‐Young , Sawada Rumi , Tsuchiya Toshie 
Published: May 2008

AbstractStannous 2‐ethylhexanoate [Sn(Oct)2] is used as a catalyst for production of poly‐L‐lactic acid and copolymers that are implanted in cranial surgery, but reports on its effects on the central nervous system are few. We examined the effects of Sn(Oct)2 on cell viability in vitro and on neurotransmission and behavior in the rat. Treatment of normal human astrocytes with 10 mg/mL Sn(Oct)2 reduced mitochondrial activity to 16% of the control. Injection of Sn(Oct)2 at 6.28 mg/kg BW (2 mg/kg BW Sn) into right lateral ventricle of the rat brain tended to increase the ambulation distance after 30 days when compared with the control group. The turnover of dopamine neurotransmission was increased in the cerebral cortex. These results suggest that Sn(Oct)2 is cytotoxic to astrocytes in vitro. Injection of Sn(Oct)2 into the brain had no or very weak immediate neurotoxicity, but long‐term exposure to Sn(Oct)2 increased dopamine neurotransmission turnover. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008