bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of N,N′‐dimethylaminoethanol as an inhibitor on the chloride threshold level for corrosion of steel reinforcement
Authors: Xu J. , Jiang L. , Xing F.
Published: November 2009

The aim of this study is to examine the influence of N,N′‐dimethylaminoethanol (DMEA) as an inhibitor on the chloride threshold level for corrosion of steel in a concrete contaminated by chlorides. The experiment has been carried out in a saturated Ca(OH)2 solution and chloride contaminated concrete containing different chloride and DMEA level. The critical point of corrosion onset is concluded by combining the open‐circuit potential (Ecorr) with corrosion current (Icorr), which is decided by electrochemical impedance spectra (EIS) in the solution. Besides, the EIS has also been applied to determinate the chloride threshold level in the chloride contaminated concrete. It has been found that the presence of DMEA represented as an amino‐alcohol inhibitor, exerts little influence on the chloride threshold level for corrosion of steel in the solution. Similarly, the effect of the DMEA on the chloride threshold level in the chloride contaminated concrete, is also negligible.
Modelling of reinforcement corrosion – geometrical effects on macrocell corrosion
Authors: Warkus J. , Raupach M.
Published: November 2009

Reinforcement corrosion is still the most frequent reason for damage of concrete structures. It can be caused by carbonation or the ingress of chlorides. In cases of localized contaminations with chlorides, macrocells with very high corrosion rates can be established. Thereby the resulting macrocell current is dependent on many different boundary conditions like driving voltage, concrete resistivity and the geometrical arrangement of anode and cathode. In order to investigate macrocell corrosion, the herein presented research work was carried out by laboratory experiments and additionally by numerical analyses. First the numerical simulations were calibrated by laboratory measurements and thereafter, a numerical parameter study was carried out to increase the available database and identify the impact of changes in single parameters. As the focus is on geometrical effects, all laboratory specimens and numerical models were designed to represent practical conditions with diverse geometrical arrangements, e.g., slabs or beams with localized depassivations. In addition, parameters like concrete resistivity, driving voltage and cathode to anode surface area ratios have been varied. Thereafter, all results were used to derive cell factors for a simple macrocell current estimation. The present status of the project will be presented and discussed.
Microstructural investigation of the oxide formed on TP 347H FG during long‐term steam oxidation
Authors: Hansson A. N. , Danielsen H. , Grumsen F. B. , Montgomery M.
Published: November 2009

The long‐term oxidation behaviour of TP347H FG in ultra supercritical steam conditions was assessed by exposing the steel in test superheater loops in a Danish coal‐fired power plant and characterising the oxide layer with reflective light and electron microscopy. Double layered oxide scales formed during steam oxidation. TEM investigations reveal that the inner oxide layer consists of particles of metallic Ni/Fe and FeCr spinel in the interior of the former alloy grains and a compact layer of FeCr spinel and Cr2O3 along the former alloy grain boundaries. The morphology suggests that the inner layer grows by internal oxidation of the interior of the alloy grains. The thickness of the inner oxide layer did not change significantly with oxidation time and temperature for exposure times up to 30 000 h. Faster Cr diffusion within the fine‐grained alloy at higher temperatures is held responsible for this observation. This hypothesis is supported by kinetic data. The oxide thickness at low and high temperatures after 58 000 h exposure was higher than expected.
Numerical model of Ca(OH)2 transport in concrete due to electrical currents
Authors: Koster T. , Peelen W. , Larbi J. , de Rooij M. , Polder R.
Published: November 2009

A mathematical model is being developed to describe a repair method in concrete, called cathodic protection (CP). The model is in principle also useful to describe electrodeposition in concrete, e.g. the process of re‐precipitation of Ca(OH)2 invoked by an electrical current. In CP, the current is sent from an external anode to the reinforcement inside the concrete. This model is implemented using the numerical software package Comsol Multiphysics. The model is based on the Nernst–Planck equations and the electroneutrality condition considering the ionic species Na+, OH− and Ca2+ and the solid Ca(OH)2. The mathematical model makes it possible to predict the location where Ca(OH)2 precipitates when a certain current density is used. This could be of great use for controlled crack repair in concrete and for electrochemical re‐alkalisation. This paper presents the qualitative behaviour of dissolution and re‐precipitation of Ca(OH)2 in CP. It discusses model calculations and preliminary experimental results. Experiments for a more complete validation of the model are in process.
Retracted: Morphology and electrochemical comparison of ceramic and composite anti‐corrosion barriers for sintered NdFeB permanent magnets
Authors: Ali A. , Ahmad A. , Deen K. M.
Published: November 2009

This article has been retracted due to a substantial overlap with a previously published article in another journal.
Corrosion and elution of harmful metals from metal buttons
Authors: Rezić I. , Zeiner M.
Published: November 2009

Metals present in metal items may due to the corrosion processes that occur in sweat cause adverse health effects, such as allergic reactions, on direct and prolonged contact with the skin. For example, 20% of female population and about 6% of male population are allergic to nickel. Therefore, three different textile accessories were tested for metal leaching: the samples were kept at 30 °C in the artificial sweat solution for different time periods and quantified. The results have shown that the limits prescribed by international standards were much exceeded. Samples of such properties present a high risk for human health and should be used with special attention.
Preparation of Polystyrene/Clay Nanocomposites by Free‐Radical Polymerization in Dispersion
Authors: Greesh Nagi , Hartmann Patrice C. , Sanderson Ronald D.
Published: November 2009

Fully exfoliated PS/clay nanocomposites were prepared via FRP in dispersion. Na‐MMT clay was pre‐modified using MPTMS before being used in a dispersion polymerization process. The objective of this study was to determine the impact of the clay concentrations on the monomer conversion, the polymer molecular weight, and the morphology and thermal stability of the nanocomposites prepared via dispersion polymerization. DLS and SEM revealed that the particle size decreased and became more uniformly distributed with increasing clay loading. XRD and TEM revealed that nanocomposites at low clay loading yielded exfoliated structures, while intercalated structures were obtained at higher clay loading.

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Effect of Intramolecular Transfer to Polymer on Stationary Free Radical Polymerization of Alkyl Acrylates, 4 ‐ Consideration of Penultimate Effect
Authors: Nikitin Anatoly N. , Hutchinson Robin A.
Published: November 2009

A penultimate model of acrylate polymerization has been proposed to account for reduced reactivity of radicals formed by monomer addition to midchain radicals. New expressions derived for polymerization rate, number‐average degree of polymerization and branching level are used for a comparative analysis of the penultimate and terminal models. The penultimate model has been also implemented into the simulation program PREDICI to conduct a comparative analysis of time dependencies of conversion, cumulative number‐degree of polymerization and cumulative branching levels calculated for the different models. The calculations show that, depending on radical reactivity ratio si and monomer concentrations, the predictions from the penultimate model significantly deviate from those of the terminal model.

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Properties of Polyvinyl Alcohol Oligomers: A Molecular Dynamics Study
Authors: Rossinsky Eddie , Tarmyshov Konstantin B. , Böhm Michael C. , Müller‐Plathe Florian
Published: November 2009

MD studies of liquid isopropyl alcohol and melts of short poly(vinyl alcohol) (PVA) oligomers are described. The specific volume was found to depend inversely on the number N of repeat units. If the chain length is enhanced, the viscosity of the PVA melt increases and the peaks in the radial distribution function become sharper. Additional peaks that appear in melts of PVA chains are of pure intramolecular origin. The calculated radius of gyration was found to depend on the number of formula units via $N^{0.65 \pm 0.03}$. The orientation correlation functions showed that all molecular vectors of PVA melts with chain lengths N = 1, 2, 3 relax completely within a few nanoseconds. The relaxation times for the OH bond vector as obtained via the Kohlrausch‐Williams‐Watts expression showed an exponential dependence on the number of repeat units.

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Nitroxide‐Mediated Radical Polymerization in Dispersed Systems: Compartmentalization and Nitroxide Partitioning
Authors: Zetterlund Per B.
Published: November 2009

Compartmentalization and nitroxide partitioning in NMP in dispersed systems have been investigated by modeling and simulations. Compartmentalization comprises the segregation effect on termination and the confined space effect on deactivation. Under certain conditions, it is possible to obtain an improvement in both control and livingness. The particle size threshold for compartmentalization, decreases with any system change that leads to a decrease in the number of propagating radicals and/or nitroxides per particle, and vice versa. There is direct competition between the confined space effect on deactivation and nitroxide exit–the more water‐soluble the nitroxide, the weaker the confined space effect. Nitroxide partitioning leads to an increase in polymerization rate and loss in control/livingness.

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Corneal confocal microscopy: A novel noninvasive means to diagnose neuropathy in patients with fabry disease
Authors: Tavakoli Mitra , Marshall Andrew , Thompson Lorraine , Kenny Margaret , Waldek Stephen , Efron Nathan , Malik Rayaz A.
Published: November 2009

Neuropathy is a cause of significant disability in patients with Fabry disease, yet its diagnosis is difficult. In this study we compared the novel noninvasive techniques of corneal confocal microscopy (CCM) to quantify small‐fiber pathology, and non‐contact corneal aesthesiometry (NCCA) to quantify loss of corneal sensation, with established tests of neuropathy in patients with Fabry disease. Ten heterozygous females with Fabry disease not on enzyme replacement therapy (ERT), 6 heterozygous females, 6 hemizygous males on ERT, and 14 age‐matched, healthy volunteers underwent detailed quantification of neuropathic symptoms, neurological deficits, neurophysiology, quantitative sensory testing (QST), NCCA, and CCM. All patients with Fabry disease had significant neuropathic symptoms and an elevated Mainz score. Peroneal nerve amplitude was reduced in all patients and vibration perception threshold was elevated in both male and female patients on ERT. Cold sensation (CS) threshold was significantly reduced in both male and female patients on ERT (P < 0.02), but warm sensation (WS) and heat‐induced pain (HIP) were only significantly increased in males on ERT (P < 0.01). However, corneal sensation assessed with NCCA was significantly reduced in female (P < 0.02) and male (P < 0.04) patients on ERT compared with control subjects. According to CCM, corneal nerve fiber and branch density was significantly reduced in female (P < 0.03) and male (P < 0.02) patients on ERT compared with control subjects. Furthermore, the severity of neuropathic symptoms and the neurological component of the Mainz Severity Score Index correlated significantly with QST and CCM. This study shows that CCM and NCCA provide a novel means to detect early nerve fiber damage and dysfunction, respectively, in patients with Fabry disease. Muscle Nerve, 2009
Vor Ort spektroskopieren
Authors: Brückner Peter , Lerm Steffen
Published: November 2009

Ein Miniaturspektrometer erfasst bis zu vier Messstellen gleichzeitig und unabhängig voneinander. Damit lassen sich Referenzmessungen durchführen, etwa für Materialuntersuchungen oder in der Lebensmittelüberwachung.
Ins Innere der Zelle
Authors: Maritzen Tanja , Haucke Volker , Wieffer Marnix
Published: November 2009

In der Endozytose gelangt Material in die Zelle. In diesen Mechanismus einzugreifen, könnte Therapien gegen Krankheiten den Weg ebnen.
Patentrecht modernisiert
Authors: Seuß Thomas
Published: November 2009

Diensterfindungen gehören jetzt automatisch dem Arbeitgeber, wenn er sie nicht ablehnt. Zudem akzeptiert das neue Gesetz E‐Mails zwischen Arbeitgeber und Arbeitnehmer zu Diensterfindungen und regelt Nichtigkeitsberufungsverfahren neu.
Application of NMR in plant metabolomics: techniques, problems and prospects
Authors: Schripsema Jan
Published: November 2009

The present state‐of‐the‐art of NMR in plant metabolomics is reviewed. Attention is paid to the different practical aspects of the application of NMR. The sample preparation, the measurement of the spectrum, quantitative aspects and data analysis are discussed. Each stage has its specific problems, which are pointed out and recommendations are made. Copyright © 2009 John Wiley & Sons, Ltd.
Sample preparation for plant metabolomics
Authors: Kim Hye Kyong , Verpoorte Rob
Published: November 2009

Sample preparation in plant metabolomics is a fundamental and critical step with important consequences for the accuracy of results. Depending on the analytical tools and the metabolites of interest, sample preparation has to be decided. However, the various methods reported in the literature have many steps in common and consequently the practical considerations concerning the pros and cons are similar. In this review, each step of the sample preparation – harvesting, drying, extraction and purification – will be discussed in detail. Copyright © 2009 John Wiley & Sons, Ltd.
Novel reworkable resins: thermo‐ and photo‐curable di(meth)acrylates
Authors: Matsukawa Daisaku , Okamura Haruyuki , Shirai Masamitsu
Published: November 2009

The aim of the study reported in this paper was to develop new di(meth)acrylates having aromatic units and thermally degradable units in their molecules. It was also the aim to clarify the photo‐curing and degradation properties of the new monomers. Di(meth)acrylates having aromatic units and thermally degradable units were synthesized. As thermally cleavable linkages, tertiary ester moieties were incorporated into the di(meth)acrylates. Three types of processes for curing and degradation of the cured resins were studied: thermal curing and thermal degradation; thermal curing and photodegradation; and photo‐curing and thermal degradation. In the thermal curing and photodegradation process, di(meth)acrylate films containing a thermally induced radical initiator and a photoacid generator (PAG) became insoluble in solvents on heating. The cured films became soluble in solvents after ultraviolet irradiation followed by baking. The re‐dissolution behaviors were strongly affected by the structures of the PAGs. A mechanism for the photo‐ or thermo‐curing and photoassisted thermal degradation was studied using Fourier transform infrared, 1H NMR, thermogravimetric, mass spectrometric and size exclusion chromatographic analyses. Copyright © 2009 Society of Chemical Industry
Symbol nomenclature for glycan representation
Authors: Varki Ajit , Cummings Richard D. , Esko Jeffrey D. , Freeze Hudson H. , Stanley Pamela , Marth Jamey D. , Bertozzi Carolyn R. , Hart Gerald W. , Etzler Marilynn E.
Published: November 2009

The glycan symbol nomenclature proposed by Harvey et al. in these pages has relative advantages and disadvantages. The use of symbols to depict glycans originated from Kornfeld in 1978, was systematized in the First Edition of “Essentials of Glycobiology” and updated for the second edition, with input from relevant organizations such as the Consortium for Functional Glycomics. We also note that >200 illustrations in the second edition have already been published using our nomenclature and are available for download at PubMed.
Streamlined ellipsometry procedure for characterizing physical aging rates of thin polymer films
Authors: Baker Elizabeth A. , Rittigstein Perla , Torkelson John M. , Roth Connie B.
Published: November 2009

Existing studies in the research literature showing conflicting changes in physical aging rates with decreasing film thickness in nanoconfined polymer films highlight the need for a single experimental technique to efficiently characterize physical aging rates in thin polymer films of varying chemical structure. To that end, we have developed a streamlined ellipsometry procedure to measure the structural relaxation of thin glassy polymer films. We evaluate different methods of calculating a physical aging rate β from the measured thickness h(t) and index of refraction n(t) data. We present extensive measurements of β as a function of aging temperature and aging time for polystyrene (PS) films supported on silicon, and determine that the physical aging rate β can be easily and reliably determined from β = −1/h0 dh/d(log t), where h0 is the initial measure of the film thickness at an aging time of 10 min. We have also carried out oxygen permeation studies on poly(methyl methacrylate) (PMMA) films from 800 μm down to 190 nm in thickness, and find no change in the permeability with film thickness or physical aging at room temperature for up to 65 days, which suggests that gas permeation may be insensitive to physical aging in such low free volume polymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2509–2519, 2009
Effect of nanoclay on relaxation of poly(vinylidene fluoride) nanocomposites
Authors: Yu Lei , Cebe Peggy
Published: November 2009

The effect of Lucentite™ STN nanoclay on the relaxation behavior of poly(vinylidene fluoride) (PVDF) nanocomposites was investigated using dielectric relaxation spectroscopy (DRS) and wide‐ and small‐angle X‐ray scattering. Lucentite™ STN is a synthetic nanoclay based on hectorite structure containing an organic modifier between the hectorite layers. The addition of this nanoclay to PVDF results in preferential formation of the beta‐crystallographic phase. When the STN content increased to 5% and 10%, only the beta‐phase was observed. Bragg long period and lamellar thickness both decrease with STN addition. The relaxation rates for processes termedαa(glass transition, related to polymer chain motions in the amorphous regions) andαc(related to polymer chain motions in the crystalline regions and fold surfaces) can be described either with the Vogel‐Fulcher‐Tamman equation or with Arrhenius behavior, respectively. DRS shows that theαarelaxation rate increases with the concentration of STN because of the reduction of intermolecular correlations between the polymer chains, caused by the presence of layered silicate nanoclay particles, which serve to segregate polymer chains in the amorphous regions. Comparing samples with beta‐crystal phase dominant, the relaxation rate for theαcrelaxation also increases with concentration of STN in all nanocomposite samples. Dielectric properties at low frequencies are dominated by the dc conductivity, and as more STN is added, the conductivity increases rapidly. The addition of 10% STN makes the dc conductivity increase by almost four decades when compared with neat PVDF. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2520–2532, 2009
Characteristics of the Deposition Rate per Unit Power on Pulsed‐DC Magnetron Sputtering Source
Authors: An Sanghyuk , In Junghwan , Chang Hongyoung
Published: November 2009

The deposition rate per unit power in a pulsed‐DC magnetron sputtering source was examined according to the target material, average power, and duty cycle. In a short duty cycle condition, the deposition rate per unit power of Ti and Cu decreased with increasing the pulse power, while that of Al and Ti in a long duty cycle condition did not change in relation to the pulse power. These results can be explained in terms of the characteristics of the sputtering yield in relation to the bombarding ion energy. Based on these results, a pulse voltage with two steps is proposed in order to increase the deposition rate per unit power.

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Plasma Polymer Coatings to Support Mesenchymal Stem Cell Adhesion, Growth and Differentiation on Variable Stiffness Silicone Elastomers
Authors: Colley Helen E. , Mishra Gautam , Scutt Andrew M. , McArthur Sally L.
Published: November 2009

The mechanical properties of the underlying substratum have previously been shown to affect a number of cellular processes including locomotion, proliferation and differentiation. Although polyacrylamide is the most studied variable‐stiffness substrate, silicone elastomers offer a more physiologically relevant range of moduli. Here, we employ plasma polymerisation to apply an acid‐containing polymer thin film to silicone elastomer substrates. This simple one‐step surface modification process renders the surfaces hydrophilic and does not require the introduction of extracellular matrix (ECM) proteins commonly used as modification agents to support cell attachment. Contact angle and XPS analysis demonstrates that the coating chemistry is consistent across all of the materials and critically, we show that the addition of this coating does not alter the underlying mechanical properties of the elastomer. The surface modification supports mesenchymal stem cell (MSC) adhesion to a level that is comparable to that seen for tissue culture polystyrene (TCPS). When used as a variable‐stiffness substrate to study cell behaviour we demonstrate that MSC proliferation is unaltered but osteogenic differentiation varies with substrate stiffness.

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The conserved active site tryptophan of thioredoxin has no effect on its redox properties
Authors: Roos Goedele , Geerlings Paul , Messens Joris
Published: November 2009

In Staphylococcus aureus thioredoxin (Trx) it has been shown that mutation of the conserved active site tryptophan residue (Trp28) has a large effect on the protein stability, on the pKa of the nucleophilic cysteine and on the redox potential. Since these effects can either be due to the partially unfolding of the Trp28Ala mutant or to the absence of the indole side chain of Trp28 as possible interaction partner for the active site cysteines, the origin of the experimentally observed effects is not known and is beyond experimental approach. With theoretical pKa and density functional theory reactivity analysis on model systems where Trp28 has been replaced by an alanine within the structural environment of Trx it is shown that Trp28 does not affect the redox parameters of Trx. As such, the experimentally observed redox effects of the Trx W28A mutant might be due to structural changes induced by partial unfolding.
Structural differences between apolipoprotein E3 and E4 as measured by 19F NMR
Authors: Garai Kanchan , Mustafi Sourajit M. , Baban Berevan , Frieden Carl
Published: November 2009

The apolipoprotein E family contains three major isoforms (ApoE4, E3, and E2) that are directly involved with lipoprotein metabolism and cholesterol transport. ApoE3 and apoE4 differ in only a single amino acid with an arginine in apoE4 changed to a cysteine at position 112 in apoE3. Yet only apoE4 is recognized as a risk factor for Alzheimer's disease. Here we used 19F NMR to examine structural differences between apoE4 and apoE3 and the effect of the C‐terminal domain on the N‐terminal domain. After incorporation of 5‐19F‐tryptophan the 1D 19F NMR spectra were compared for the N‐terminal domain and for the full length proteins. The NMR spectra of the N‐terminal region (residues 1–191) are reasonably well resolved while those of the full length wild‐type proteins are broad and ill‐defined suggesting considerable conformational heterogeneity. At least four of the seven tryptophan residues in the wild type protein appear to be solvent exposed. NMR spectra of the wild‐type proteins were compared to apoE containing four mutations in the C‐terminal region that gives rise to a monomeric form either of apoE3 under native conditions (Zhang et al., Biochemistry 2007; 46: 10722–10732) or apoE4 in the presence of 1 M urea. For either wild‐type or mutant proteins the differences in tryptophan resonances in the N‐terminal region of the protein suggest structural differences between apoE3 and apoE4. We conclude that these differences occur both as a consequence of the Arg158Cys mutation and as a consequence of the interaction with the C‐terminal domain.
Immunosuppressive CD14+HLA‐DRlow/− monocytes in prostate cancer
Authors: Vuk‐Pavlović Stanimir , Bulur Peggy A. , Lin Yi , Qin Rui , Szumlanski Carol L. , Zhao Xinghua , Dietz Allan B.
Published: November 2009

OBJECTIVE

To determine if the levels of circulating myeloid‐derived suppressor cells increase with progression of prostate cancer (PCa); to determine if such cells could contribute to the relative inefficiency of PCa immunotherapy.

MATERIALS AND METHODS

We analyzed peripheral blood mononuclear cells isolated from untreated PCa patients (uPCa; N = 18; mean age ± SD: 72.1 ± 6.9 years), tPCa (N = 22; 72.8 ± 9.8 years) and age matched controls (AMC; N = 12; 68.8 ± 7.5 years). We quantified surface marker phenotype, differentiation potential, effects on T cell proliferation and intracellular cytokines.

RESULTS

We observed an unexpectedly high percentage of a type of myeloid‐derived suppressor cells, CD14+HLA‐DRlow/− monocytes, in tPCa (30.7 ± 15.0% of CD14+ cells) relative to AMC (4.1 ± 6.5%, P < 0.0001) and uPCa (10.6 ± 14.3%, P = 0.0001). The levels of CD14+ HLA‐DRlow/− cells were significantly correlated with circulating PSA levels and treatment with LHRH‐agonist leuprolide in combination with either an antiandrogen or dexamethasone. Monocytes from tPCa inhibited autologous T cell proliferation statistically significantly more effectively than AMC monocytes and were defective in their ability to differentiate into phenotypically mature dendritic cells. Isolated CD14+HLA‐DRlow/− cells expressed higher levels of intracellular interleukin‐10 and suppressed T cell proliferation more effectively than isolated CD14+HLA‐DR+ cells.

CONCLUSIONS

This is the first report of CD14+ cells exhibiting reduced expression of HLA‐DR molecules in PCa patients. These cells suppress immune cell function in vitro and, plausibly, in vivo, a finding that must be factored into the design of immunotherapy protocols for PCa patients. Prostate 70: 443–455, 2010. © 2009 Wiley‐Liss, Inc.
Monocyte chemotactic protein‐1 (MCP‐1/CCL2) is associated with prostatic growth dysregulation and benign prostatic hyperplasia
Authors: Fujita Kazutoshi , Ewing Charles M. , Getzenberg Robert H. , Parsons J. Kellogg , Isaacs William B. , Pavlovich Christian P.
Published: November 2009

BACKGROUND

Chronic inflammation is commonly observed in benign prostate hyperplasia (BPH), and prostate tissue often contains increased inflammatory infiltrates, including T cells and macrophages. Cytokines are not only key mediators of inflammation but may also play important roles in the initiation and progression of BPH.

METHODS

In order to determine what cytokines might be involved in prostatic enlargement, expressed prostatic secretions (EPS) from ex vivo prostates were analyzed by human cytokine antibody microarray and ELISA. Prostate epithelial cells (PrEC) and prostate stromal cells (PrSC) were used for ELISA, proliferation, and Western blot assays.

RESULTS

Monocyte chemotactic protein‐1 (MCP‐1/CCL2) was one of the most elevated proteins in secretions from large prostate glands. PrSC were found to secrete MCP‐1; Western blotting showed that both PrSC and PrEC express the MCP‐1 receptor CCR2 which by RT‐PCR was the CCR2b isoform. Proliferation assays showed that MCP‐1 stimulates the proliferation of PrEC, but not PrSC, and that a specific MCP‐1 antagonist (RS102895) suppressed this effect. Conditioned medium from PrSC stimulated the proliferation of PrEC as well, an effect completely inhibited by both RS102895 and a neutralizing anti‐MCP‐1 monoclonal antibody. The inflammatory cytokines interleukin (IL)‐1β, interferon‐γ, and IL‐2 enhanced the secretion of MCP‐1 from PrEC and PrSC. In addition, MCP‐1 levels in EPS correlated with mRNA levels of the macrophage marker CD68 in the same secretions.

CONCLUSIONS

The cytokine MCP‐1, of apparent prostatic stromal cell origin, may play an important role in prostatic enlargement and BPH, and is a candidate biomarker for these pathologic processes. Prostate 70: 473–481, 2010. © 2009 Wiley‐Liss, Inc.
Vacancy‐patterned graphene: A meta‐material for spintronics
Authors: Artyukhov Vasilii I. , Chernozatonskii Leonid A.
Published: November 2009

We use density functional theory to explore the implications of atomically precise patterning of graphene with monovacancies. We show that one‐dimensional tracks of vacancies can be used to turn graphene into a magnetic meta‐material with properties that can be flexibly varied by external factors such as doping. Chemical functionalization by H or F atoms does not disrupt the magnetic structure of the material; moreover, controlled passivation with appropriate chemical species could be used as an additional means to tailor the properties of the meta‐material. This leads us to propose patterning of graphene with vacancy tracks as a possible route towards integrated spintronic circuits on single graphene sheets. Several possible pathways towards practical fabrication of such systems are discussed.

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Spin density in graphene with periodically arranged monovacancies.
Preparation and electrochemical characterization of LiMnPO4/single‐walled carbon nanotube composites as cathode material for Li‐ion battery
Authors: Dettlaff‐Weglikowska Urszula , Sato Norio , Yoshida Jun , Roth Siegmar
Published: November 2009

We investigated the synthesis of the nanocrystalline LiMnPO4 and its composites with single‐walled carbon nanotubes (SWNTs) in order to apply them as cathode material in Li‐ion battery. Two synthesis routes, precipitation and sol–gel, have been evaluated with regard to elemental composition, crystal size and crystal structure. Precipitation of LiMnPO4 from aqueous solution produces microcrystalline material with low specific surface area of 5 m2/g. Sol–gel procedure and in situ incorporation of SWNTs reduce the particle size to less than 100 nm and enhances specific surface area by factor of 10. Both materials have been used to prepare a cathode and the electrochemical performance of assembled battery has been tested. Whereas the electrical conductivity of the composite increases by 5 orders of magnitude upon addition of 1 wt.% of SWNTs, the battery capacity with a value of 20 mAh/g (theoretical 175 mAh/g) still appears low. We found out that incorporation of LiMnPO4 nanocrystals in a dense SWNT network (bucky paper) improves significantly the battery performance, and capacity approaching 150 mAh/g can be achieved. Our experiments provides the proof of principle that individual nanosize particles of LiMnPO4 can be sufficiently separated by conducting SWNTs to prevent their agglomeration, and electrically wired in a network for efficient electronic and ionic transport through the cathode.
Gas chromatography coupled to electron capture negative ion mass spectrometry with nitrogen as the reagent gas – an alternative method for the determination of polybrominated compounds
Authors: Rosenfelder Natalie , Vetter Walter
Published: November 2009

Gas chromatography in combination with electron capture negative ion mass spectrometry (GC/ECNI‐MS) is a sensitive method for the determination of polybrominated compounds in environmental and food samples via detection of the bromide ion isotopes m/z 79 and 81. The standard reagent gas for inducing chemical ionization in GC/ECNI‐MS is methane. However, the use of methane has some drawbacks as it promotes carbonization of the filament and ion source. In this study, we explored the suitability of nitrogen as reagent gas for the determination of brominated flame retardants (polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), allyl‐2,4,6‐tribromophenyl ether (ATE) and 2,3‐dibromopropyl‐2,4,6‐tribromophenyl ether (DPTE)) and halogenated natural products (for instance, methoxylated tetrabrominated diphenylethers and polybrominated hexahydroxanthene derivatives). An ion source temperature of 250°C and a nitrogen pressure of 7 Torr in the ion source gave the highest response for m/z 79 and 81 of virtually all investigated polybrominated compounds. Using these conditions, nitrogen‐mediated GC/ECNI‐MS usually gave higher sensitivity than the method with methane previously used in our lab. In addition, the ion source was not contaminated to the same degree and the lifetime of the filament was significantly increased. Moreover, the response factors of the different polybrominated compounds with the exception of 2,4,6‐tribromophenol were more uniform than with methane. Nitrogen is available at very high purity at relatively low price. Copyright © 2009 John Wiley & Sons, Ltd.
Re‐presenting the social construction of science in light of the propositions of Bruno Latour: For a renewal of the school conception of science in secondary schools
Authors: Richard Vincent , Bader Barbara
Published: November 2009

Current opinion holds that school science has not been producing the expected outcomes. Highlighted by a considerable body of research, one of the concerns is that young people still mobilize a naive conception of science. Consequently, we must pursue the reflection process concerning ways of renewing the school conception of science so as to propose ways of representing and doing that are a greater source of participation among students. In this article, we argue for the importance of enriching school discourses by mobilizing a socialized conception of science. Our perspective seeks to highlight the major theoretical contributions of ethnomethodology put forward by Bruno Latour. Hence, we propose an operational definition of the social construction of science based on actor‐network theory as an attempt to produce a more focused conceptualization of science as a social enterprise. This theoretical work enables us to bring out various facets of the social construction of science that, in our view, should be accounted for in classes to renew the school image of science in line with the characteristics of contemporary technosciencesin the making. Finally, we illustrate how we can mobilize this understanding of science for secondary students. © 2009 Wiley Periodicals, Inc.Sci Ed94:743–759, 2010
Micro X‐ray diffraction and fluorescence tomography for the study of multilayered automotive paints
Authors: De Nolf Wout , Janssens Koen
Published: November 2009

Combined microscopic X‐ray fluorescence/microscopic X‐ray diffraction (µ‐XRF/µ‐XRD) tomography is a recently developed method that allows the visualization of the distribution of chemical elements and the associated crystalline phases inside complex, heterogeneous materials of extended thickness (millimeter range) in a nondestructive fashion. In this paper, the accuracy and resolution with which the individual layers in a multilayer stack of automotive paints can be distinguished is evaluated, and some of their properties measured. A paint layer system of eight layers was investigated, in which eight different crystalline substances were identified, each layer consisting of an organic, synthetic resin doped with finely milled inorganic compounds that serve as pigments or to strengthen the layer. In the XRD tomograms, all paint layers could be straightforwardly distinguished and their average thickness calculated. In case the filtered back projection method was used for tomogram reconstruction, a spatial resolution comparable to the microbeam size was obtained indicating no significant reconstruction blurring. When a more robust reconstruction method, such as the maximum‐likelihood expectation maximization method, was employed, tomograms showing fewer artifacts were obtained, but with a spatial resolution that was two times worse. In the corresponding XRF tomograms, significant self‐absorption distorted the element‐specific tomograms corresponding to the low‐energy (<7 keV) characteristic radiation and limited their usefulness. It can be concluded that microbeam XRD tomography allows the accurate visualization of the distribution of crystalline phases in multilayered automotive paint materials of millimeter dimensions with sufficient resolution to allow separate characterization of each layer in terms of its crystal‐phase composition and thickness. Copyright © 2009 John Wiley & Sons, Ltd.
Optimal combination of estimating equations in the analysis of multilevel nested correlated data
Authors: Stoner J. A. , Leroux B. G. , Puumala M.
Published: November 2009

Multilevel nested, correlated data often arise in biomedical research. Examples include teeth nested within quadrants in a mouth or students nested within classrooms in schools. In some settings, cluster sizes may be large relative to the number of independent clusters and the degree of correlation may vary across clusters. When cluster sizes are large, fitting marginal regression models using Generalized Estimating Equations with flexible correlation structures that reflect the nested structure may fail to converge and result in unstable covariance estimates. Also, the use of patterned, nested working correlation structures may not be efficient when correlation varies across clusters. This paper describes a flexible marginal regression modeling approach based on an optimal combination of estimating equations. Particular within‐cluster and between‐cluster data contrasts are used without specification of the working covariance structure and without estimation of covariance parameters. The method involves estimation of the covariance matrix only for the vector of component estimating equations (which is typically of small dimension) rather than the covariance matrix of the observations within a cluster (which may be of large dimension). In settings where the number of clusters is large relative to the cluster size, the method is stable and is highly efficient, while maintaining appropriate coverage levels. Performance of the method is investigated with simulation studies and an application to a periodontal study. Copyright © 2009 John Wiley & Sons, Ltd.
Voluntary agreements to improve environmental quality: symbolic and substantive cooperation
Authors: Delmas Magali A. , Montes‐Sancho Maria J.
Published: November 2009

Within the context of environmental voluntary agreements (VAs), this paper analyzes the determinants of the degree of participation by firms in collective corporate political strategies that aim to shape government policy. We demonstrate that substantive cooperative strategies are more likely to be pursued by firms that enter a VA close to its initiation, while symbolic cooperation is more likely behavior by late joiners. We show that late joiners and early joiners within VAs adopt different cooperative strategies because they face different institutional pressures. Our analysis is based on the strategies of firms participating in the Climate Challenge program (1995–2000) established by the U.S. Department of Energy and representatives of the national electric utilities to reduce greenhouse gas emissions. Our results show that early joiners were subjected to higher levels of political pressure at the state level and were more dependent on local and federal regulatory agencies than late joiners were. Early joiners were also better connected to the trade association and more visible. Late joiners had undertaken significantly less investment in environmental improvements than early joiners. Our paper also illustrates the difficulty involved in using VAs to try to induce improved environmental outcomes when there are no sanctioning mechanisms. Although early entrants reduced their emissions more than nonparticipants, our results show no significant difference overall between participants and nonparticipants in the reduction of their emissions. Copyright © 2010 John Wiley & Sons, Ltd.
Tunable Two‐Dimensional Binary Molecular Networks
Authors: Huang Yu Li , Chen Wei , Li Hui , Ma Jing , Pflaum Jens , Wee Andrew Thye Shen
Published: November 2009

A novel approach to constructing tunable and robust 2D binary molecular nanostructures on an inert graphite surface is presented. The guest molecules are embedded into a host molecular matrix and constrained via the formation of multiple intermolecular hydrogen bonds. By varying the binary molecular ratio and the molecular geometry, various molecular arrays with tunable intermolecular distances are fabricated. The results suggest a promising route for the fabrication of ordered and stable molecular nanostructure arrays for molecular sensors, molecular spintronic devices, and molecular p–n nanojunctions.
Proteolytic Fluorescent Signal Amplification on Gold Nanoparticles for a Highly Sensitive and Rapid Protease Assay
Authors: Kim Joong H. , Chung Bong H.
Published: November 2009

A new strategy for highly sensitive and rapid protease assay is developed by mediating proteolytic formation of oligonucleotide duplexes and using the duplexes for signal amplification. In the presence of matrix metalloprotease‐2 (MMP‐2), fragmentation of the intact DNA–peptide on gold nanoparticles (GNP) by hydrolytic cleavage of a peptide bond within the substrate allows diffusion of DNA away from the GNP and the formation of a DNA/RNA heteroduplex, leading to digestion of RNA by RNase H. Because of the high quenching efficacy of GNP to the fluorophore in RNA and multiple digestions of the RNA, the fluorescence signal recovery is amplified. This method permits the assessment of the activity of MMP‐2 at concentrations as low as 10 pMwithin 4 h. Compared with the reported protease nanosensors using quantum dots, GNP, and magnetic nanoparticles with the same peptide sequence, the assay time of this method is sixfold faster and the limit of detection is 100‐fold more sensitive. The formulations for proteolytic formations of oligonucleotides duplexes for signal amplification on GNP could lead to the development of more sensitive and rapid protease assay techniques, thus extending the role of proteases as therapeutic targets and disease indicators.
Rank methods
Authors: Wolfe Douglas A.
Published: November 2009

One of the major goals of statistics is to use data collected from a population to make inferences (hypothesis tests, confidence regions, and point estimators) about unknown attributes of the population. When there are good reasons to believe that the basic features of a population can be well approximated by a standard probability distribution, such as the commonly used Gaussian distribution, then a variety of approaches are available to construct procedures with optimal properties. When, however, a particular distribution is not an appropriate model for a population, the statistical procedures that are optimal for that distribution may not perform well; that is, model‐based statistical procedures may not be robust to departures from the assumed model. In such situations, one can use nonparametric procedures that maintain important stipulated properties (such as nominal significance level for hypothesis tests and coverage probability for confidence regions) over broad classes of probability distributions. While such nonparametric procedures are not optimal for a specific probability model, they are generally robust to deviations from that model. Many nonparametric procedures rely on simple counting and ranking processes applied either directly to the sample data or to some natural function of it and they are commonly known in the statistical literature as rank methods. In this article, we discuss the two basic approaches that lead to distribution‐free test procedures based on ranks and then illustrate how distribution‐free confidence intervals and robust point estimators can be derived directly from these hypothesis tests. Copyright © 2009 John Wiley & Sons, Inc.

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Nonparametric Methods
The boundary of source materials for recent Chinese history and the integrity of historiography: With reference to the compilation and publication of relevant historical materials
Authors: Bing SANG
Published: November 2009

With a dramatic expansion in quantity and variety, the amount of recent history source materials has surpassed the sum total of those available for all earlier dynasties. At the same time, compared with the case in ancient history study, the obscure boundary of source materials has made it difficult for historians to locate and obtain what they need for their research. Since it is impossible to exhaust or to ascertain the boundary of relevant sources, scholars either retreat into narrower fields or make arbitrary interpretations of materials, both contributing to the loss of orientation in historical study, and, for that matter, eroding the integrity of historiography. Historians must, first and foremost, acquire a comprehensive understanding of the discipline before they can undertake studies on any particular subject, which is the proper way to conduct historical study and to avoid short-sightedness or a tunnel vision of the scene. The author of this paper believes that it is urgent to resolve the dilemma in preserving and utilizing source materials by publishing as many materials as possible efficiently so that scholars on recent Chinese history can stand on an equal footing as far as materials are concerned. Only in this way will they be able to undertake deeper investigations, to uncover the complex correlation between source materials and historical study, and ultimately, to contribute to recent history study as a whole.
On Thomas Aquinas’ doctrine of materia signata
Authors: Dezhi DUAN , Dunhua ZHAO
Published: November 2009

Aquinas’ doctrine of materia signata or “designated matter” is an important deviation from the traditional doctrines on matter. Through in-depth typological and genetic analyses of the related concepts, this essay explores materia signata’s ontological qualities, generative mechanism and function, as well as its academic significance in the history of both Christian theology and Western philosophy.
The philosophy of scientific practice in naturalist thought: Its approaches and problems
Authors: Xiaofei TIAN
Published: November 2009

It is the continuity between epistemology and empirical science that the naturalism in contemporary philosophy of science emphasizes. After its individual and social dimensions, the philosophy of scientific practice takes a stand on naturalism in order to observe complex scientific activities through practice. However, regarding the naturalism’s problem of normativity, the philosophy of scientific practice today has deconstructed more than it has constructed.
The three-form reasoning of new Hetu-vidya in Indian logic from the perspective of modern logic
Authors: Zhongyi ZHANG , Jialong ZHANG
Published: November 2009

Comparing the three-form reasoning of new Hetu-vidya with Western logic, scholars have put forward four perspectives. Combining their strengths and shortcomings, and the examples of Hetu-vidya reasoning, we can conclude that the three-form reasoning should have four forms: (1) the affirmative expression of formal implication; (2) the modus ponens of hypothetical reasoning concerning sufficient conditions after universal instantiation; (3) the negative expression of a formal implication; and (4) the modus tollens of hypothetical reasoning concerning sufficient conditions after universal instantiation.