bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vitamin D deficiency and myocardial diseases
Authors: Pilz Stefan , Tomaschitz Andreas , Drechsler Christiane , Dekker Jacqueline M. , März Winfried 
Published: March 2010

AbstractVitamin D deficiency is common among patients with myocardial diseases because sun‐induced vitamin D production in the skin and dietary intake of vitamin D is often insufficient. Knockout mice for the vitamin D receptor develop myocardial hypertrophy and dysfunction. It has also been shown that children with rickets who suffered from severe heart failure could be successfully treated with supplementation of vitamin D plus calcium. In adults, almost all patients with heart failure exhibit reduced 25‐hydroxyvitamin D levels, which are used to classify the vitamin D status. In prospective studies, vitamin D deficiency was an independent risk factor for mortality, deaths due to heart failure and sudden cardiac death. Several vitamin D effects on the electrophysiology, contractility, and structure of the heart suggest that vitamin D deficiency might be a causal factor for myocardial diseases. Data from interventional trials, however, are rare and urgently needed to elucidate whether vitamin D supplementation is useful for the treatment of myocardial diseases. In our opinion, the current knowledge of the beneficial effects of vitamin D on myocardial and overall health strongly argue for vitamin D supplementation in all vitamin D‐deficient patients with or at high risk for myocardial diseases.
Eicosapentaenoic acid up‐regulates apelin secretion and gene expression in 3T3‐L1 adipocytes
Authors: Lorente‐Cebrián Silvia , Bustos Matilde , Marti Amelia , Martinez José Alfredo , Moreno‐Aliaga María Jesús 
Published: March 2010

AbstractRecent studies have shown the ability of apelin to restore glucose tolerance in obese and insulin‐resistant mice. Eicosapentaenoic acid (EPA) is a polyunsaturated fatty acid (PUFA) from the omega‐3 family that has many beneficial effects in obesity‐linked disorders. The aim of this study was to examine in vitro the effects of EPA on apelin secretion and gene expression in mature 3T3‐L1 adipocytes. Treatment with EPA (100 and 200 μM) significantly increased basal (p<0.01) and insulin‐stimulated (p<0.001) apelin secretion and gene expression in adipocytes. EPA also stimulated Akt phosphorylation, a down‐stream target of phosphatidylinositol 3‐kinase (PI3K), in 3T3‐L1 adipocytes. Moreover, treatment with the PI3K inhibitor LY294002 completely blocked EPA‐stimulatory action on apelin mRNA gene expression (p<0.001), but not modified the stimulatory effect of EPA on basal apelin secretion. Furthermore, the stimulatory effect of EPA on basal apelin release was also observed in the presence of Actinomycin D and Cycloheximide, suggesting that EPA might also regulate apelin secretion by via post‐transcriptional mechanisms. These findings suggest that the mechanisms mediating EPA‐induced apelin synthesis and/or secretion are complex, involving steps that are PI3K dependent and steps that are PI3K independent.
Age‐ and sex‐related differences in muscle phosphocreatine and oxygenation kinetics during high‐intensity exercise in adolescents and adults
Authors: Willcocks Rebecca J. , Williams Craig A. , Barker Alan R. , Fulford Jon , Armstrong Neil 
Published: March 2010

AbstractThe aim of this investigation was to examine the adaptation of the muscle phosphates (e.g. phosphocreatine (PCr) and ADP) implicated in regulating oxidative phosphorylation, and oxygenation at the onset of high intensity exercise in children and adults. The hypotheses were threefold: primary PCr kinetics would be faster in children than adults; the amplitude of the PCr slow component would be attenuated in children; and the amplitude of the deoxyhaemoglobin/myoglobin (HHb) slow component would be reduced in children. Eleven children (5 girls, 6 boys, 13 ± 1 years) and 11 adults (5 women, 6 men, 24 ± 4 years) completed two to four constant work rate exercise tests within a 1.5 T MR scanner. Quadriceps muscle energetics during high intensity exercise were monitored using 31P‐MRS. Muscle oxygenation was monitored using near‐infrared spectroscopy. The time constant for the PCr response was not significantly different in boys (31 ± 10 s), girls (31 ± 10 s), men (44 ± 20 s) or women (29 ± 14 s, main effects: age, p = 0.37, sex, p = 0.25). The amplitude of the PCr slow component relative to end‐exercise PCr was not significantly different between children (23 ± 23%) and adults (17 ± 13%, p = 0.47). End‐exercise [PCr] was significantly lower, and [ADP] higher, in females (18 ± 4 mM and 53 ± 16 µM) than males (23 ± 4 mM, p = 0.02 and 37 ± 11 µM, p = 0.02), but did not differ with age ([PCr]: p = 0.96, [ADP]: p = 0.72). The mean response time for muscle tissue deoxygenation was significantly faster in children (22 ± 4 s) than adults (27 ± 7 s, p = 0.01). The results of this study show that the control of oxidative metabolism at the onset of high intensity exercise is adult‐like in 13‐year‐old children, but that matching of oxygen delivery to extraction is more precise in adults. Copyright © 2010 John Wiley & Sons, Ltd.
Hybrid finite element/volume method for shallow water equations
Authors: Aliabadi Shahrouz , Akbar Muhammad , Patel Reena 
Published: March 2010

AbstractA hybrid numerical scheme based on finite element and finite volume methods is developed to solve shallow water equations. In the recent past, we introduced a series of hybrid methods to solve incompressible low and high Reynolds number flows for single and two‐fluid flow problems. The present work extends the application of hybrid method to shallow water equations. In our hybrid shallow water flow solver, we write the governing equations in non‐conservation form and solve the non‐linear wave equation using finite element method with linear interpolation functions in space. On the other hand, the momentum equation is solved with highly accurate cell‐center finite volume method. Our hybrid numerical scheme is truly a segregated method with primitive variables stored and solved at both node and element centers. To enhance the stability of the hybrid method around discontinuities, we introduce a new shock capturing which will act only around sharp interfaces without sacrificing the accuracy elsewhere. Matrix‐free GMRES iterative solvers are used to solve both the wave and momentum equations in finite element and finite volume schemes. Several test problems are presented to demonstrate the robustness and applicability of the numerical method. Copyright © 2010 John Wiley & Sons, Ltd.
Copolymerization of diglycidylether of bisphenol A and bicyclic bis(γ‐lactone)s using rare earth metal triflates as initiators studied with infrared spectroscopy
Authors: Arasa Mercé , Ramis Xavier , Salla Josep Maria , Mantecón Ana , Serra Angels 
Published: March 2010

AbstractThe thermal cationic curing of mixtures, in various proportions, of diglycidylether of bisphenol A with two substituted condensed bis(γ‐lactone)s initiated using scandium, ytterbium and lanthanum triflates or a conventional boron trifluoride monoethylamine (BF3·MEA) initiator was investigated. The evolution of the various reactive groups was followed by means of attenuated total reflection Fourier transform infrared spectroscopy. The formation of mono‐spiroorthoesters (monoSOE)s and bis‐spiroorthoesters (bisSOE)s is discussed. The polymerization of bisSOE structures led to the formation of ether–ester–ketone repeat units, which implied the cationic polymerization took place by a tandem reaction. The use of scandium triflate as an initiator led to the highest chemical incorporation of lactone in the network. Moreover, this initiator was the most active, incorporating a higher proportion of lactone in a shorter time. In contrast, the conventional BF3·MEA initiator incorporated the lowest proportion of bislactone in the cured material. Copyright © 2010 Society of Chemical Industry
Glycoprotein production for structure analysis with stable, glycosylation mutant CHO cell lines established by fluorescence‐activated cell sorting
Authors: Wilke Sonja , Krausze Joern , Gossen Manfred , Groebe Lothar , Jäger Volker , Gherardi Ermanno , van den Heuvel Joop , Büssow Konrad 
Published: March 2010

AbstractStable mammalian cell lines are excellent tools for the expression of secreted and membrane glycoproteins. However, structural analysis of these molecules is generally hampered by the complexity of N‐linked carbohydrate side chains. Cell lines with mutations are available that result in shorter and more homogenous carbohydrate chains. Here, we use preparative fluorescence‐activated cell sorting (FACS) and site‐specific gene excision to establish high‐yield glycoprotein expression for structural studies with stable clones derived from the well‐established Lec3.2.8.1 glycosylation mutant of the Chinese hamster ovary (CHO) cell line. We exemplify the strategy by describing novel clones expressing single‐chain hepatocyte growth factor/scatter factor (HGF/SF, a secreted glycoprotein) and a domain of lysosome‐associated membrane protein 3 (LAMP3d). In both cases, stable GFP‐expressing cell lines were established by transfection with a genetic construct including a GFP marker and two rounds of cell sorting after 1 and 2 weeks. The GFP marker was subsequently removed by heterologous expression of Flp recombinase. Production of HGF/SF and LAMP3d was stable over several months. 1.2 mg HGF/SF and 0.9 mg LAMP3d were purified per litre of culture, respectively. Homogenous glycoprotein preparations were amenable to enzymatic deglycosylation under native conditions. Purified and deglycosylated LAMP3d protein was readily crystallized. The combination of FACS and gene excision described here constitutes a robust and fast procedure for maximizing the yield of glycoproteins for structural analysis from glycosylation mutant cell lines.
Low‐temperature transmission electron microscopy study of superconducting Nb3Sn
Authors: Schierning G. , Theissmann R. , Acet M. , Hoelzel M. , Gruendmayer J. , Zweck J. 
Published: March 2010

AbstractBy low‐temperature transmission electron microscopy we have found nanodomains in a polycrystalline Nb3Sn sample. We interpret that these nanodomains form due to a tetragonal distortion. Because twinning seems to be a prominent feature of the real structure of many high Tc superconductors, possible interactions between a twinned structure and superconductivity are briefly discussed.
Recent advances and challenges for successful p‐type control of InN films with Mg acceptor doping by molecular beam epitaxy
Authors: Yoshikawa Akihiko , Wang Xinqiang , Ishitani Yoshihiro , Uedono Akira 
Published: March 2010

AbstractInN is still the least studied material among III‐nitrides and there are several problems to be overcome for better understanding of its material properties and also its material control for device application. In particular, successful p‐type doping is a quite important issue but quite difficult in InN. In this article, we present a study on the latest advances in material control paying special attention to the p‐type doping of InN films using Mg‐acceptors by MBE, the demonstration of successful p‐type control and p‐type conduction, and their electrical and optical properties as well. Furthermore, as a prerequisite of successful p‐type doping of InN, epitaxy behaviors of InN on GaN and effects of threading dislocations on high‐purity undoped InN epilayers grown on GaN template are also discussed.
FPGA‐based LAPS device for the flexible design of sensing sites on functional interfaces
Authors: Wagner Torsten , Werner Carl Frederik , Miyamoto Ko‐ichiro , Ackermann Hans‐Josef , Yoshinobu Tatsuo , Schöning Michael J. 
Published: March 2010

AbstractThe development of new interfaces for (bio‐)chemical sensors requires comprehensive analyses and testing. The light‐addressable potentiometric sensor (LAPS) can be used as a platform to investigate the sensitivity of a newly developed interface towards (bio‐)chemical agents. LAPS measurements are spatially resolved by utilisation of focused light beams to define individual measurement spots. In this work, a new digitally modulated LAPS set‐up based on an FPGA design will be introduced to increase the number of measurement spots, to shorten the measurement time and to improve the measurement accuracy.
Deposition of functionalized gold nanoparticles onto modified silicon substrates
Authors: Riskin A. , De Dobbelaere C. , Elen K. , D'Haen J. , Van den Rul H. , Mullens J. , Hardy A. , Van Bael M. K. 
Published: March 2010

AbstractIn this report, an existing phase transfer method for the synthesis of alkylamine‐ or alkanethiol‐functionalized gold nanoparticles (NPs) is investigated. A parameter study shows that the concentration of the gold salt used is important for the stability of the resulting sol, but has little effect on the final average particle size or the size distribution. By adding dodecanethiol before the reduction, the formation of NPs was inhibited, providing evidence for the autocatalytic pathway for the formation of metallic NPs in wet chemical synthesis proposed in the literature. The resulting functionalized gold NPs are deposited onto Si–OH, octadecyltrichlorosilane (OTS) or 3‐mercaptopropyltrimethoxysilane modified SiO2/Si substrates. scanning electron microscope (SEM) is used to analyze the ordering behavior and surface coverage of the NPs and it is shown that the difference in affinity for the substrate has a profound effect on the deposition behavior. The functionalization of the substrates and of the NPs is confirmed by grazing angle attenuated total reflectance fourier transform infrared spectroscopy (GATR‐FTIR).
A hierarchical modeling approach to accelerated degradation testing data analysis: A case study
Authors: Pan Rong , Crispin Taeho 
Published: March 2010

AbstractIn this case study, we investigate the degradation process of light‐emitting diodes (LEDs), which is used as a light source in DNA sequencing machines. Accelerated degradation tests are applied by varying temperature and forward current, and the light outputs are measured by a computerized measuring system. A degradation path model, which connects to the LED function recommended in Mitsuo (1991), is used in describing the degradation process. We consider variations in both measurement errors and degradation paths among individual test units. It is demonstrated that the hierarchical modeling approach is flexible and powerful in modeling a complex degradation process with nonlinear function and random coefficient. After fitting the model by maximum likelihood estimation, the failure time distribution can be obtained by simulation. Copyright © 2010 John Wiley & Sons, Ltd.
Silver nanostructures via cementation on copper: a comparison between experimental data and statistical design model
Authors: Ahmed E. S. , Fouad O. A. , El‐Midany A. A. , El‐Sabbagh E. A. , Abd El‐Rahman A. , Ibrahim I. A. 
Published: March 2010

AbstractSilver nanostructures have been precipitated successfully from acidic solutions of silver ions via cementation on copper sheets. The experimental parameters that have been studied are time, temperature of reaction, pH and initial silver ion concentration. XRD analysis showed that precipitated silver particles werecomposed mainly of metallic silver. No other phases such as silver oxide, sulfide or sulfate could be detected. SEM investigations confirmed that silver nanostructures were deposited mainly in the form of nanoparticles, dendrites or nanorods as the parameters varied. The average silver nanoparticle size that could be obtained by optimizing the experimental conditions of cementation process was about 60 nm. This value was in agreement with that obtained from application of factorial design under the same conditions. Copyright © 2010 John Wiley & Sons, Ltd.
Ancient surfaces in thought and reality
Authors: Paparazzo Ernesto 
Published: March 2010

AbstractThis article discusses the issue of surfaces, as seen under the different standpoints of archaeometric surface science studies and ancient philosophy. Previous XPS and scanning Auger microscopy (SAM) archaeometric studies which were conducted to analyse the microchemical composition of ancient metals are reviewed and shown that a careful consultation of relevant ancient sources can greatly assist in achieving both a correct interpretation of the experimental results and an assessment of their archaeological import. Then other ancient sources in which surfaces are the subject of speculation in Greek philosophy, focusing particularly on the views of surfaces enterained by Plato, Aristotle and the Stoic philosopher Posidonius are reviewed. It is concluded by arguing that under both the scientific–archaeometric and the philosophical standpoints, surfaces should be considered an important aspect of our cultural heritage. Copyright © 2010 John Wiley & Sons, Ltd.
The effect of insulator layer thickness on the main electrical parameters in (Ni/Au)/AlxGa1−xN/AlN/GaN heterostructures
Authors: Altındal Şemsettin , Şafak Yasemin , Taşçıoğlu İlke , Özbay Ekmel 
Published: March 2010

Abstract(Ni/Au)AlxGa1−xN/AlN/GaN(x = 0.22) heterostructures with and without a passivation layer of the SiNx were fabricated in order to see the effect of the insulator layer on the main electrical parameters such as zero‐bias barrier height (BH) (ΦB0), ideality factor (n), series resistance (Rs) of the structure, and the interface state density (Nss). Some of these parameters were determined from both I–V and admittance (C–V and G/ω–V) measurements at room temperature and at 1 MHz and were compared. The experimental results show that the value of Nss in a Schottky contact without passivation is nearly 1 order of magnitude larger than that in a Schottky contact with SiNx passivation layers. Also, the values of Rs increase with the increasing thickness of the passivation layer. In the forward bias region, the negative values of capacitance are an attractive result of this study. This negative capacitance disappears in presence of the passivation layer. Copyright © 2010 John Wiley & Sons, Ltd.
Preparation of exfoliated clay/polymer nanocomposites via organosilane grafting and in situ ATRP of glycidyl methacrylate
Authors: Djouani Fatma , Herbst Frederic , Chehimi Mohamed M. , Benzarti Karim 
Published: March 2010

AbstractClay/polymer nanocomposites, of the type montmorillonite/poly(glycidyl methacrylate) (MMT/PGMA), were synthesized via atom transfer radical polymerization (ATRP). MMT was amino‐silanized and then reacted with 2‐bromoisobutyryl bromide (BIB) to provide NH‐C(‐C(CH3)2Br groups attached to the clay. The latter (MMT‐SiBr) served as macroinitiator for the in situ ATRP of GMA. The resulting MMT/PGMA nanocomposites were found to be highly exfoliated, as judged by X‐ray diffraction (XRD) measurements. Thermogravimetric analysis (TGA) and XPS analyses suggest that the nanocomposites have PGMA‐rich bulk and surface. Indeed, the mass loading of PGMA reached 65 wt. % while XPS spectra, particularly the high‐resolution C1s region, resemble those of pure PGMA.These clay/PGMA nanocomposites are suitable as nanofillers for epoxy adhesives, since PGMA chains are both compatible with epoxy resins and reactive towards crosslinkers via the pendant glycidyl groups from PGMA grafts. Copyright © 2010 John Wiley & Sons, Ltd.
Chemical analysis of a sulfur‐treated InSb(111)A surface by XPS
Authors: Lebedev Mikhail V. , Shimomura Masaru , Fukuda Yasuo 
Published: March 2010

AbstractChemistry of an InSb(111)A surface treated with ammonium sulfide solution followed by annealing at various temperatures has been studied by x‐ray photoelectron spectroscopy (XPS). It is found that indium sulfide is formed and the intensity ratio of indium sulfide to indium antimonide on the as‐treated surface is almost unity at the detection angles of the normal (0° ) and 80° off the normal to the surface. Upon annealing the sample at 250 °C, the ratio significantly increased and slightly decreased at 80° and 0° , respectively. It decreased upon further annealing and finally indium sulfide disappeared at 390 °C, where the 2 × 2 low energy electron diffraction (LEED) patters were observed. The SbS/O component is detected for the as‐treated surface and it disappeared upon annealing at 250 °C. Three components of sulfur are found: the main one at 161.6 eV, and the other weak ones at 163.1 and 160.2 eV. The 161.6‐ and 163.1‐eV peaks can be ascribed to sulfur bonded to indium and antimony, respectively. The latter component disappeared upon annealing at 250 °C. The behavior of the sulfides upon annealing the sample at various temperatures is discussed in terms of dissociation of SbS and diffusion of sulfur in the surface region. Copyright © 2010 John Wiley & Sons, Ltd.
XPS investigations of valence changes during cycling of LiCrMnO4‐based cathodes in Li‐ion batteries
Authors: Oswald S. , Nikolowski K. , Ehrenberg H. 
Published: March 2010

AbstractLi‐ion batteries have to be improved for high‐performance applications especially for automotive application. One aim is the search for new electrode materials with superior properties and their detailed characterization. We used ‘quasi in situ’ X‐ray photoelectron spectroscopy (XPS) to investigate electrode material of the spinel‐type LiCrMnO4 for the cathode during electrochemical cycling. It was found that during charging (de‐intercalation of Li from the cathode) chromium is converted from Cr3+ to Cr6+, whereas manganese changes from Mn4+ to Mn3+. Especially when charging to the maximum capacity (at about 5.2 V), this conversion seems to be partially irreversible. The chemical and structural changes connected with this conversion are the possible reason for the irreversible capacity loss at such high charging voltages, which is confirmed by the analysis of the electrode material after 100 charging/discharging cycles. Copyright © 2010 John Wiley & Sons, Ltd.
Phase explosion in tungsten target under interaction with Nd:YAG laser tripled in frequency
Authors: Yahiaoui K. , Kerdja T. , Malek S. 
Published: March 2010

AbstractIn this work, we report on the ablation of a tungsten target with a nanosecond Nd:YAG laser of high intensity, ranging from 2 × 108 to 1011 W/cm2, at 355 nm wavelength. We use a microbalance device and SEM to analyze the phase explosion mechanism. The microbalance was placed in front of the target where the maximum ejection of matter took place. The results obtained showed two kinds of ablation process: normal surface evaporation at low laser intensity (below 1010 W/cm2) followed by explosive boiling (also called phase explosion) at a threshold laser intensity of 6 × 1010 W/cm2. The analysis of the surface crater formed by 1, 5 and 10 laser shots on the target at high laser intensity by SEM showed that the morphology of the crater consists of pores and cavities which are due to bubble nucleation when the critical temperature of tungsten is reached. These bubbles are the characteristic of phase explosion transformation. Copyright © 2010 John Wiley & Sons, Ltd.
Surface modification of 2017‐T4 aluminium alloy by high power diode laser melting
Authors: Arias J. , Benedetti A. , Cabeza M. , Castro G. , Feijoo I. , Merino P. , Nóvoa X. R. 
Published: March 2010

AbstractLaser surface melting (LSM) using a high power diode laser was used to modify the surface of AA 2017‐T4 alloy. The first part of this work concerns the applicability of diode laser to surface melting of the AA2017‐T4 alloy. Irradiation conditions were varied to investigate the effect of process parameters on the treated surface. The results show that the application of diode laser makes treating the surface of this alloy possible. Microstructural characterisation of the bulk material and the remelted surface layer was performed using scanning electron microscopy, transmission electron microscopy and X‐ray diffraction. The combination of the three techniques allows the identification of the intermetallic compounds—down to nanometre size—in the surface layer. Copyright © 2010 John Wiley & Sons, Ltd.