bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of Polar Ethylene–Norbornene Copolymers by Metallocene Terpolymerization with Triisobutylaluminium‐Protected But‐3‐en‐1‐ol
Authors: Liu Shaojie , Yao Zhen , Cao Kun , Li Bogeng , Zhu Shiping 
Published: February 2009

AbstractBut‐3‐en‐1‐ol has been pre‐protected by triisobutylaluminium and terpolymerized with ethylene and norbornene by rac‐[Et(Ind)2]ZrCl2/MAO catalysts. The strong polarity of diisobutyl(but‐3‐en‐1‐oxy)aluminum causes a slight reduction in the catalyst activity and yields a small fraction of crystallinity. The but‐3‐en‐1‐ol content in the terpolymer is as high as 3.2% and can be readily adjusted by varying the reaction conditions. When the norbornene/ethylene ratio is over 10, the norbornene incorporation efficiency is not affected by the polar monomer and is close to that of the copolymerization. Similar to the ethylene/norbornene copolymers, the thermal properties of the obtained terpolymers are mainly determined by their norbornene contents.magnified image
Chemical Crosslinking of PVA and Prediction of Material Properties by Means of Fully Atomistic MD Simulations
Authors: Bermejo Javier Sacristan , Ugarte Carmen Mijangos 
Published: February 2009

AbstractA method has been developed for building fully atomistic models of chemically crosslinked PVA. It combines a dynamic crosslinking approach followed by a high‐temperature annealing procedure. The crosslinking procedure allows to control both crosslinking density and the amount of free crosslinking sites. It also takes into account some network defects, such as dangling tails and wasted loops, which have been experimentally observed on chemically crosslinked polymer networks. This procedure is applied to PVA which is chemically crosslinked with two different linear polyols. Several material properties such as glass transition temperature, Young's, shear and bulk modulus were predicted from the equilibrated structures and found to agree well with available experimental data.magnified image
Distinct patterns of regional cerebral glucose metabolism in Parkinson's disease with and without mild cognitive impairment
Authors: Hosokai Yoshiyuki , Nishio Yoshiyuki , Hirayama Kazumi , Takeda Atsushi , Ishioka Toshiyuki , Sawada Yoichi , Suzuki Kyoko , Itoyama Yasuto , Takahashi Shoki , Fukuda Hiroshi , Mori Etsuro 
Published: February 2009

AbstractThere is no consensus with regard to the clinical and neuroimaging characteristics of prodromal dementia in Parkinson's disease (PD). To delineate functional neuroimaging features of PD with mild cognitive impairment (PDMCI) and with no cognitive impairment (PDNC), we compared regional cerebral glucose metabolism (CMRglc) amongst 13 patients with PDMCI, 27 with PDNC, and 13 healthy controls. The PDNC patients had limited areas of hypometabolism in the frontal and occipital cortices. In the PDMCI patients, there were extensive areas of hypometabolism in the posterior cortical regions, including the temporo‐parieto‐occipital junction, medial parietal, and inferior temporal cortices. The present results suggest that posterior cortical dysfunction is the primary neuroimaging feature of PD patients at risk for dementia. © 2009 Movement Disorder Society
Lie group transformations for self‐similar shocks in a gas with dust particles
Authors: Jena J. 
Published: February 2009

AbstractIn this paper, Lie group of transformation method is used to investigate the self‐similar solutions for the system of partial differential equations describing one‐dimensional unsteady plane flow of an inviscid gas with large number of small dust particles. The forms of the drag force D and the heat transfer rate Q experienced by the particle not in equilibrium with the gas have been derived for which the system of equations admits self‐similar solutions. A particular solution to the problem in one case have been found out and is used to study the effect of the dust particles on the similarity exponent. Copyright © 2009 John Wiley & Sons, Ltd.
Free and bound fumonisins in gluten‐free food products
Authors: Dall'Asta Chiara , Galaverna Gianni , Mangia Mattia , Sforza Stefano , Dossena Arnaldo , Marchelli Rosangela 
Published: February 2009

AbstractIn this work a multiresidual LC‐ESI‐MS/MS method for the simultaneous detection of free and bound fumonisins is described, which allowed for a very low LOD and a very good recovery for all the analytes. The method was applied to the determination of free and bound fumonisins in several gluten‐free products from the Italian market. Free fumonisins were found to occur in 90% of the samples: the overall median value was below the EU legal limit for foods for human consumption (800 μg/kg). Nonetheless, fumonisins occurred in several samples at concentrations above the legal limit, reaching also very strong contamination levels (maximum concentration level: 3310 μg/kg). Anyway, considering the limited diet of people suffering of the celiac disease or allergic to other wheat proteins, the incidence of fumonisin contamination may be envisaged as problematic. Furthermore, bound fumonisins were found to be present in all the analysed samples at similar or even higher amounts than the free forms. In many cases the sum of free and bound fumonisins exceeded the EU legal limit for total fumonisins also for those samples characterized by a low contamination of free fumonisins, thus opening a new important task to be addressed for the risk assessment in this field.
Phenolic acids in black raspberry and in the gastrointestinal tract of pigs following ingestion of black raspberry
Authors: Wu Xianli , Pittman III Hoy E. , Hager Tiffany , Hager Aaron , Howard Luke , Prior Ronald L. 
Published: February 2009

AbstractBlack raspberries (BRB) contain high levels of polyphenols and have been demonstrated to be chemopreventive. In order to investigate the underlying mechanism and study the metabolism of anthocyanins, pigs were fed freeze‐dried BRB powder or purified diet (control) and three segments of the gastrointestinal (GI) tract (small intestine, cecum, and colon; 4 h after feeding) were collected for analysis of phenolic acids. Protocatechuic acid was the major phenolic acid (8.35 mg/100 g, dry weight (DW)) in BRB, followed by p‐coumaric acid (1.63 mg/100 g, DW), caffeic acid (1.34 mg/100 g, DW), ferulic acid (0.24 mg/100 g, DW), and 3‐hydroxybenzoic acid (0.20 mg/100 g, DW). Recoveries of these five phenolic acids in the whole GI tract were 199.9 ± 54.0%, 7.0 ± 3.0%, 37.0 ± 9.7%, 56.6 ± 31.3%, and 916.8 ± 642.3% (mean ± SEM, n = 5), respectively, and quantities in contents of the GI tract ranged from 0.13 ± 0.05 μmol (p‐coumaric acid) to 23.47 ± 6.09 μmol (protocatechuic acid) (mean ± SEM, n = 5). Six other phenolic acids were detected primarily in the cecum and/or colon which were not in BRB, with total contents in the GI tract ranging from 0.18 ± 0.18 μmol (homovanillic acid) to 8.49 ± 4.31 μmol (homoprotocatechuic acid). Total phenolic acids in the GI tract were 49.32 ± 16.37 μmol (mean ± SEM, n = 5). Phenolic acids measured in the GI tract accounted for only 6.31% of the degraded anthocyanins.
Towards DSM‐V: considering other withdrawal‐like symptoms of pathological gambling disorder
Authors: Cunningham‐Williams Renee M. , Gattis Maurice N. , Dore Peter M. , Shi Peichang , Spitznagel Edward L. 
Published: February 2009

AbstractDespite clinical reports of other withdrawal‐like symptoms, the DSM‐IV considers only restlessness/irritability as a withdrawal‐like criterion comprising pathological gambling disorder (PGD). We explored whether this criterion should be broadened to include other gambling withdrawal‐like symptoms.Community‐recruited adult gamblers (n = 312) participated in telephone interviews about gambling and related behaviors as a part of a larger psychometric study. Frequency and chi‐square analyses described the association of gambling withdrawal‐like symptoms by gambling disorder status. Multinomial forward selection logistic regression obtained a multivariate model describing the simultaneous relationship between these symptoms and gambling disorder status.One‐quarter of the sample experienced the DSM‐IV PGD criterion of restlessness/irritability. However, 41% experienced additional gambling withdrawal‐like symptoms when attempting to quit or control gambling. A model including restlessness/irritability and three additional non‐DSM‐IV withdrawal‐like symptoms (i.e. feelings of anger, guilt, and disappointment) is a stronger model of gambling disorder (χ2 = 217.488; df = 8, p < 0.0001; R2 = 0.5428; p < 0.0001) than restlessness/irritability alone (χ2 = 151.278; df = 2, p < 0.0001; R2 = 0.4133). The overlap of gambling withdrawal‐like symptoms with substance use withdrawal (11%) and depressive symptoms (34%) failed to fully account for these associations with gambling disorder status.Future PGD conceptualization and potential criteria revisions for DSM‐V may warrant a broader inclusion of gambling withdrawal‐like symptoms. Copyright © 2009 John Wiley & Sons, Ltd.
Dicer is required for female reproductive tract development and fertility in the mouse
Authors: Gonzalez Gabriel , Behringer Richard R. 
Published: February 2009

AbstractDicer encodes a riboendonuclease required for microRNA biosynthesis. Dicer was inactivated in Müllerian duct mesenchyme‐derived tissues of the reproductive tract of the mouse, using an Amhr2‐Cre allele. Although Amhr2‐Cre; Dicer conditional mutant males appeared normal and were fertile, mutant females were infertile. In adult mutant females, there was a reduction in the size of the oviducts and uterine horns. The oviducts were less coiled compared to controls and cysts formed at the isthmus near the uterotubal junction. Unfertilized, degenerate oocytes were commonly found within these cysts, indicating a defect in embryo transit. Beads transferred into the mutant oviduct failed to migrate into the uterus. In addition, blastocysts transferred directly into the mutant uterus did not result in pregnancy. Histological analysis demonstrated that the mutant uterus contained less glandular tissue and often the few glands that remained were found within the myometrium, an abnormal condition known as adenomyosis. In adult mutants, there was ectopic expression of Wnt4 and Wnt5a in the luminal epithelium (LE) and glandular epithelium (GE) of the uterus, and Wnt11 was ectopically expressed in GE. These results demonstrate that Dicer is necessary for postnatal differentiation of Müllerian duct mesenchyme‐derived tissues of the female reproductive tract, suggesting that microRNAs are important regulators of female reproductive tract development and fertility. Mol. Reprod. Dev. 76: 678–688, 2009. © 2009 Wiley‐Liss, Inc.
Perceived behavioral atypicality as a predictor of social rejection and peer victimization: Implications for emotional adjustment and academic achievement
Authors: DeRosier Melissa E. , Mercer Sterett H. 
Published: February 2009

AbstractThis study examined perceived behavioral atypicality as a predictor of children's school‐based adjustment. First, a descriptive pilot study was conducted to examine children's reasons for nominating peers as behaviorally atypical. Then, atypicality was investigated in relation to school‐based adjustment in a two‐wave panel design. Social problems, emotional adjustment, and academic achievement were assessed in the fall and spring of a school year with 1,193 third‐grade students via peer‐, teacher‐, and self‐report instruments as well as school records. In the fall, atypicality was related to higher levels of social rejection and peer victimization as well as impaired emotional adjustment and academic achievement. When examined across the school year, atypicality, as mediated by higher levels of social rejection and peer victimization, predicted impaired emotional adjustment and academic achievement. Discussion focuses on the importance of considering behavioral atypicality as a broad risk factor with implications for school‐based intervention. © 2009 Wiley Periodicals, Inc.
Layered silicate‐polyamide‐6 nanocomposites: Influence of silicate species on morphology and properties
Authors: Tamura Kenji , Uno Hikaru , Yamada Hirohisa , Umeyama Kiyoshi 
Published: February 2009

AbstractThe effect of two different species of layered silicates on the morphology, mechanical properties, and methanol vapor barrier properties of polyamide‐6 (PA6) nanocomposites was examined using identical experimental conditions for both species. The layered silicate species used were natural montmorillonite (MMT) and synthetic expandable fluoro‐mica (FM), the chemical compositions of which were Na0.43(Al1.56Mg0.31Fe2+
0.09)(Si3.95Al0.05)O10(OH)2 and Na0.66Mg2.68(Si3.98Al0.02)O10F2, respectively. The layered silicates were modified with a dodecylammonium salt (DDA) using an ion‐exchange method. The resulting organically modified layered silicates were melt‐kneaded with PA6 in a twin‐screw kneader at 260 °C. By quantitative analysis of the silicate layers dispersed in the PA6, the number‐average aspect ratio was estimated to be 76 for DDAMMT‐PA6 and 85 for DDAFM‐PA6. This confirmed that the primary particle size of the initial silicate did affect the aspect ratio. The rigidity and gas barrier properties of the nanocomposites appeared to depend upon the morphology of the nanocomposite. On the other hand, the elongation at break of the nanocomposites decreased as the amount of silicate increased. This reduction in ductility was ascribed to the difference in morphology of the nanocomposites, that is, distribution of silicate nanolayers in the polymer matrix. The homogeneity of the particle fraction of exfoliated nanolayers was clearly an important factor affecting the properties of the nanocomposites. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 583–595, 2009
Synthesis of Allylamine Plasma Polymer Films: Correlation between Plasma Diagnostic and Film Characteristics
Authors: Denis Laurent , Cossement Damien , Godfroid Thomas , Renaux Fabian , Bittencourt Carla , Snyders Rony , Hecq Michel 
Published: February 2009

AbstractPrimary amine‐based plasma polymer films (NH2‐PPF) were synthesized using plasma polymerization of allylamine in continuous wave (CW) and pulsed radio‐frequency (RF) modes. Plasma chemistry, studied by residual gas analysis mass spectrometry, revealed that the precursor fragmentation is a function of the equivalent power (Peq) dissipated in the discharge, independently of the plasma mode used. X‐ray photoelectron spectroscopy combined with time‐of‐flight secondary ion mass spectrometry suggests as the precursor fragmentation in the plasma increases: (i) a decrease of the primary amine concentration in the NH2‐PPF (%NH2) and (ii) an increase of the cross‐linking degree. For a given Peq, similar to the precursor fragmentation in the plasma, the NH2‐PPF characteristics were found to be independent of the plasma mode used. Therefore, the main advantage of using pulsed RF processes over CW ones is the possibility to work at very low Peq which enables low precursor fragmentation, optimization of %NH2, and reduction of the film cross‐linking degree. The chemical composition and the cross‐linking degree of the NH2‐PPF synthesized by allylamine plasma polymerization can thus be tailored by adjusting the equivalent RF power injected in the plasma.magnified image
The EPR of monoclinic KY(WO4)2 single crystal doped with Sm3+ ion
Authors: Borowiec M. T. , Prokhorov A. D. , Dyakonov V. P. , Kamenev V. I. , Prokhorov A. A. , Aleshkevych P. , Zayarnyuk T. , Szymczak H. 
Published: February 2009

AbstractThe electron paramagnetic resonance (EPR) of Sm3+ ion in KY(WO4)2 single crystal was investigated at T = 4.2 K using an X‐band spectrometer. The observed resonance absorption represents the complex superposition of three spectra corresponding to samarium isotopes with different nuclear moment. The EPR spectrum is characterised by a strong g ‐factor anisotropy. The temperature dependences of the g ‐factor were shown to be caused by strong spin–orbital and orbital–lattice coupling. The resonance lines become broader as temperature increases due to the short spin–lattice relaxation time. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Goos–Hänchen shift in one‐dimensional photonic crystals containing uniaxial indefinite medium
Authors: Pan Tao , Xu Guoding , Zang Taocheng , Gao Lei 
Published: February 2009

AbstractWe study numerically the Goos–Hänchen (GH) shift of a light wave transmitted from one‐dimensional photonic crystals containing a uniaxial indefinite medium. It is found that the permittivity and permeability of the indefinite medium strongly affect the properties of the GH shift. The (positive or negative) GH shift is greatly enhanced near the band edge of photonic crystals, the sign of the GH shift in the low‐ and high‐frequency edges of the photonic bandgap can be different. In addition, the properties of the GH shift are also strongly dependent on the incident light frequency, incident angle and the orientation of the optical axis. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination of homogeneous and inhomogeneous broadenings of quantum‐well excitons by 2DFTS: An experiment‐theory comparison
Authors: Kuznetsova Irina , Thomas Peter , Meier Torsten , Zhang Tianhao , Cundiff Steven T. 
Published: February 2009

AbstractThe cover picture of this issue of Phys. Status Solidi C has been taken from the article [1] (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Survival analysis using inverse probability of treatment weighted methods based on the generalized propensity score
Authors: Sugihara Masahiro 
Published: February 2009

AbstractIn survival analysis, treatment effects are commonly evaluated based on survival curves and hazard ratios as causal treatment effects. In observational studies, these estimates may be biased due to confounding factors. The inverse probability of treatment weighted (IPTW) method based on the propensity score is one of the approaches utilized to adjust for confounding factors between binary treatment groups. As a generalization of this methodology, we developed an exact formula for an IPTW log‐rank test based on the generalized propensity score for survival data. This makes it possible to compare the group differences of IPTW Kaplan–Meier estimators of survival curves using an IPTW log‐rank test for multi‐valued treatments. As causal treatment effects, the hazard ratio can be estimated using the IPTW approach. If the treatments correspond to ordered levels of a treatment, the proposed method can be easily extended to the analysis of treatment effect patterns with contrast statistics. In this paper, the proposed method is illustrated with data from the Kyushu Lipid Intervention Study (KLIS), which investigated the primary preventive effects of pravastatin on coronary heart disease (CHD). The results of the proposed method suggested that pravastatin treatment reduces the risk of CHD and that compliance to pravastatin treatment is important for the prevention of CHD. Copyright © 2009 John Wiley & Sons, Ltd.
Metabolism of methyltestosterone in the greyhound
Authors: Biddle S. T. B. , O'Donnell A. , Houghton E. , Creaser C. 
Published: February 2009

AbstractGas chromatography/mass spectrometry and selective derivatisation techniques have been used to identify urinary metabolites of methyltestosterone following oral administration to the greyhound. Several metabolites were identified including reduced, mono‐, di‐ and trihydroxylated steroids. The major metabolites observed were 17α‐methyl‐5β‐androstane‐3α‐17β‐diol, 17α‐methyl‐5β‐androstane‐3α,16α,17β‐triol, and a further compound tentatively identified as 17α‐methyl‐5z‐androstane‐6z,17β‐triol. The most abundant of these was the 17α‐methyl‐5β‐androstane‐3α,16α,17β‐triol. This metabolite was identified by comparison with a reference standard synthesised using a Grignard procedure and characterised using trimethylsilyl (TMS) and acetonide‐TMS derivatisation techniques. There did not appear to be any evidence for 16β‐hydroxylation as a phase I metabolic transformation in the greyhound. However, significant quantities of 16α‐hydroxy metabolites were detected. Selective enzymatic hydrolysis procedures indicated that the major metabolites identified were excreted as glucuronic acid conjugates. Metabolic transformations observed in the greyhound have been compared with those of other mammalian species and are discussed here. Copyright © 2009 John Wiley & Sons, Ltd.
Terrain Adaptive Navigation for planetary rovers
Authors: Helmick Daniel , Angelova Anelia , Matthies Larry 
Published: February 2009

AbstractThis paper describes the design, implementation, and experimental results of a navigation system for planetary rovers called Terrain Adaptive Navigation (TANav). This system was designed to enable greater access to and more robust operations within terrains of widely varying slippage. The system achieves this goal by using onboard stereo cameras to remotely classify surrounding terrain, predict the slippage of that terrain, and use this information in the planning of a path to the goal. This navigation system consists of several integrated techniques: goodness map generation, terrain triage, terrain classification, remote slip prediction, path planning, High‐Fidelity Traversability Analysis, and slip‐compensated path following. Results from experiments with an end‐to‐end onboard implementation of the TANav system in a Mars analog environment are shown and compared to results from experiments with a more traditional navigation system that does not account for terrain properties. © 2009 Wiley Periodicals, Inc.
Field‐Emission Resonances at Tip/α,ω‐Mercaptoalkyl Ferrocene/Au Interfaces Studied by STM
Authors: Müller‐Meskamp Lars , Karthäuser Silvia , Zandvliet Harold J. W. , Homberger Melanie , Simon Ulrich , Waser Rainer 
Published: February 2009

AbstractThe electrical properties of α,ω‐mercaptoalkyl ferrocenes with different alkyl chain lengths embedded in a self‐assembled host matrix of alkanethiols on Au(111) are studied by scanning tunneling microscopy and spectroscopy. Based on current–distance spectroscopy, as well as on the evaluation of Fowler–Nordheim tunneling current oscillations, the apparent barrier height of ferrocene is determined independently by two methods. The electronic coupling of the ferrocene moiety to the Au(111) substrate is shown to depend on the length of the alkane‐spacer chain. In a double tunnel junction model our experimental findings are explained, addressing the role of the different molecular moieties of the mercaptoalkyl ferrocenes.
AFM Tip Hammering Nanolithography
Authors: Wang You , Hong Xiaodong , Zeng Jun , Liu Baoquan , Guo Bin , Yan Honghua 
Published: February 2009

AbstractNanolithography at low cost and high speed is made possible by using a vibrating AFM tip in tapping‐mode as a nanohammer to forge polystyrene‐block‐poly(ethylene/butylenes)‐block‐polystyrene triblock copolymer monolayer thin films after annealing to transform their microstructures from as‐cast poorly ordered cylinders into well‐ordered hexagonal spheres. Annealing is accomplished in cyclohexane vapor, a selective solvent for the majority poly(ethylene/butylenes) block. Experimental results demonstrate that such structure‐tailored thin films enable macroscopic AFM tip writing to be performed in their surface; imprinted and embossed patterns can be generated with a sub‐20‐nm line‐width resolution. In addition, it is found that the lithographic patterns generated can be erased within 5 min by thermal annealing at 70 °C, and if necessary the erasion process can be expedited by increasing the annealing temperature.