bluuebunny/crossref_metadata_2025 huggingface dataset:
Formation of carbamates by reaction between ester carbanions and isocyanates: General regularities and scope
Authors: Gololobov Yuri G. , Borisov Yuri A. , Slepchenkov Nikolii , Barabanov Sergey , Petrovskii Pavel V. , Nelyubina Julija V.
Published: April 2010

General regularities and scope of reactions carbanions with the ester group at carbanionic center and arylisocyanates resulting formation of carbamates by C → N migrations of ester groups have been described. The use of tosylisocyanates terminated reactions at the first stage with formation of corresponding tosylacylamides. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 21:119–125, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20585
Experimental investigation of heat transfer enhancement using impingement of multiple water jets
Authors: Murthy Niranjan , Krishnan V. , Reddy A. Chennakesava
Published: April 2010

The problem of cooling electronic components has become a subject of special interest in recent years due to the increasing capacity and rapidly decreasing size of electronic components. Direct contact cooling using multiple jet impingement is considered the most effective method. The heat transfer problem is complex and a better understanding of the jet impingement method is essential for the proper application of this method for electronic cooling. Investigations were carried out using an electrically heated test plate. Heat flux in the range of 25 to$200 \ \hbox{W/cm}^{2}$, which is a typical requirement for cooling high power electronic components was dissipated using 0.5‐mm diameter water jets arranged in a 7×7 array with a pitch of 3 mm. Temperature difference between the test plate and water was within$30 \ ^{\circ}\hbox{C}$. Tests were performed in the flow rate range of 22 to 40 ml/min, resulting in a Reynolds number range of 1100 to 1750. Results show a significant increase in the heat transfer coefficient or Nusselt number with an increase in heat flux. The effect of the flow rate or Reynolds number on the heat transfer coefficient is found to be negligible. © 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20291
He's homotopy perturbation method for two‐dimensional heat conduction equation: Comparison with finite element method
Authors: Jalaal M. , Ganji D.D. , Mohammadi F.
Published: April 2010

Heat conduction appears in almost all natural and industrial processes. In the current study, a two‐dimensional heat conduction equation with different complex Dirichlet boundary conditions has been studied. An analytical solution for the temperature distribution and gradient is derived using the homotopy perturbation method (HPM). Unlike most of previous studies in the field of analytical solution with homotopy‐based methods which investigate the ODEs, we focus on the partial differential equation (PDE). Employing the Taylor series, the gained series has been converted to an exact expression describing the temperature distribution in the computational domain. Problems were also solved numerically employing the finite element method (FEM). Analytical and numerical results were compared with each other and excellent agreement was obtained. The present investigation shows the effectiveness of the HPM for the solution of PDEs and represents an exact solution for a practical problem. The mathematical procedure proves that the present mathematical method is much simpler than other analytical techniques due to using a combination of homotopy analysis and classic perturbation method. The current mathematical solution can be used in further analytical and numerical surveys as well as related natural and industrial applications even with complex boundary conditions as a simple accurate technique. © 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20292
Alterations of T‐cell surface markers in older women with persistent human papillomavirus infection
Authors: Rodríguez Ana Cecilia , García‐Piñeres Alfonso J. , Hildesheim Allan , Herrero Rolando , Trivett Matthew , Williams Marcus , Atmella Ivannia , Ramírez Margarita , Villegas Maricela , Schiffman Mark , Burk Robert , Freer Enrique , Bonilla José , Bratti Concepción , Pinto Ligia A.
Published: April 2010

We previously reported decreased lymphocyte proliferative responses among older women with persistent human papillomavirus (HPV) infection. To characterize the phenotype of peripheral lymphocytes associated with persistent HPV infection, we evaluated the expression of different cell surface markers in peripheral blood mononuclear cells (PBMCs) from a case–control study within a 10,049 woman population‐based cohort study in Guanacaste, Costa Rica. Women in the cohort aged 46–74 and with HPV results at their 5th year anniversary visit were considered, and all women (n = 87) with persistent HPV infections, all women (n = 196) with transient HPV infections and a random sample of HPV DNA‐negative women (n = 261) frequency‐matched to cases on age were selected for this study. A median of 3 years after the case–control matching visit, cervical cells were collected for liquid‐based cytology and repeat HPV DNA genotyping. Blood was obtained from which PBMCs were extracted and cryopreserved for immunological phenotyping via flow cytometry. Significant increases in risk of HPV persistence were observed for 3 marker subsets indicative of immune cell activation/differentiation. Relative risk estimates were 5.4 (95% CI = 2.2–13.3) for CD69+CD4+, 2.6 (95% CI = 1.2–5.9) for HLADR+CD3+CD4+ and 2.3 (95% CI = 1.1–4.7) for CD45RO+CD27−CD8+. A significant decrease in HPV persistence was observed for a subset marker indicative of an immature, undifferentiated memory state CD45RO+CD27+CD4+ (OR = 0.36; 95% CI = 0.17–0.76). Adjustment for these markers only partially explained the previously reported association between decreased lymphoproliferative responses and persistent HPV infection. Whether phenotypic alterations observed predispose to HPV persistence or result from it should be the focus of future studies.
Prolonged antiresorptive activity of zoledronate: A randomized, controlled trial
Authors: Grey Andrew , Bolland Mark , Wattie Diana , Horne Anne , Gamble Greg , Reid Ian R
Published: April 2010

Annual intravenous administration of 5 mg of zoledronate decreases fracture risk over 3 years. The optimal dosing interval of 5 mg of zoledronate is not known. In order to determine the duration of the antiresorptive action of a single 5-mg dose of intravenous zoledronate, we conducted a 3-year double-blind, randomized, placebo-controlled trial in a volunteer sample of 50 postmenopausal women with osteopenia. The coprimary endpoints were the bone turnover markers β-C-terminal telopeptide of type I collagen (β-CTX) and serum procollagen type-I N-terminal propeptide (P1NP). Secondary endpoints were bone mineral density (BMD) at the lumbar spine, total hip, and total body. After 3 years, mean (95% confidence interval) levels of serum β-CTX and P1NP were 44% (27–60) and 40% (24%–56%) lower in the zoledronate group (p < .001 versus placebo for each marker). BMD was higher in the zoledronate group than in the placebo group by an average of 6.8% (4.6%–9.1%) at the lumbar spine, 4.0% (1.8%–6.3%) at the total hip, and 2.0% (0.9%–3.0%) at the total body (p < .001 for each skeletal site). Between-group differences in markers of bone turnover and BMD were stable from 12 to 36 months. These data demonstrate that the antiresorptive effects of a single 5-mg dose of zoledronate are sustained for 3 years; clinical trials to investigate the antifracture efficacy of dosing intervals longer than 1 year are justified. © 2010 American Society for Bone and Mineral Research.
Prenatal and early life arsenic exposure induced oxidative damage and altered activities and mRNA expressions of neurotransmitter metabolic enzymes in offspring rat brain
Authors: Xi Shuhua , Guo Li , Qi Rong , Sun Wenjuan , Jin Yaping , Sun Guifan
Published: April 2010

To better understand the effect of arsenic on central nervous system by prenatal and early life exposure, the oxidative stress and neurotransmitter metabolic enzymes were determined in offspring rats' brain cortex and hippocampus. Forty‐eight pregnant rats were randomly divided into four groups, each group was given free access to drinking water that contained 0, 10, 50, and 100 mg/L NaAsO2 from gestation day 6 (GD 6) until postnatal day 42 (PND 42). Once pups were weaned, they started to drink the same arsenic (As)‐containing water as the dams. The level of malondialdehyde in 100 mg/L As‐exposed pup's brain on PND 0 and cortex on PND 28 and 42 were significantly higher than in the control group (p < 0.05). Reduced glutathione (GSH) levels showed a clear decreasing trend in pup's cortex and hippocampus on PND 42. Activity of acetylcholinesterase was significantly higher in 100 mg/L As‐exposed pup's hippocampus than in control group on PND 28 and 42. mRNA expression of glutamate decarboxylase (GAD65 and GAD67) in 100 mg/L As‐exposed pup's cortex or hippocampus on PND 28 and 42 were significantly higher than in control (p < 0.05). These alterations in the neurotransmitters and reduced antioxidant defence may lead to neurobehavioral and learning and memory changes in offspring rats. © 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 24:368–378, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.20349
The dialectical behavior therapy ways of coping checklist: development and psychometric properties
Authors: Neacsiu Andrada D. , Rizvi Shireen L. , Vitaliano Peter P. , Lynch Thomas R. , Linehan Marsha M.
Published: April 2010

Skills training is a crucial mode of treatment in dialectical behavioral therapy (DBT; Linehan, 1993b), yet a psychometrically sound measure of DBT skills use does not exist. We adapted the Revised Ways of Coping Checklist (RWCCL; Vitaliano, Russo, Carr, Maiuro, & Becker, 1985) to create the DBT Ways of Coping Checklist (DBT‐WCCL). Using factor analysis procedures, two subscales emerged: one assessing coping via DBT skills, the DBT Skills Subscale (DSS), and one assessing coping via dysfunctional means, the Dysfunctional Coping Subscale (DCS). Principal component, internal consistency, test‐retest reliability, and content validity analyses suggested that the scale has good to excellent psychometric properties. In addition, the DSS successfully discriminated patients who received skills training during 4 months of treatment from patients who did not. Moderators of skills use are also discussed. The DBT‐WCCL appears to be a promising new measure of DBT skills use. © 2010 Wiley Periodicals, Inc. J Clin Psychol: 66:1–20, 2010.
A geospatial statistical analysis of the density of lottery outlets within ethnically concentrated neighborhoods
Authors: Wiggins Lyna , Nower Lia , Mayers Raymond Sanchez , Peterson N. Andrew
Published: April 2010

This study examines the density of lottery outlets within ethnically concentrated neighborhoods in Middlesex County, New Jersey, using geospatial statistical analyses. No prior studies have empirically examined the relationship between lottery outlet density and population demographics. Results indicate that lottery outlets were not randomly dispersed across the county but rather were significantly clustered in some census tracts. Using geospatial statistical analysis, percent poverty was found to be negatively related to the density of lottery outlets, while percent commercial use was highly positively related. Percent Hispanic was strongly significant in all the models predicting lottery outlet density and had the highest explanatory power other than percent commercial. Other independent variables, including median household income and race (African American and White) were not found to be significant predictors of lottery outlet density. Implications for policy and research are discussed.
History of studies on mammalian middle ear evolution: A comparative morphological and developmental biology perspective
Authors: Takechi Masaki , Kuratani Shigeru
Published: April 2010

The mammalian middle ear represents one of the most fundamental morphological features that define this class of vertebrates. Its skeletal pattern differs conspicuously from those of other amniotes and has attracted the attention of comparative zoologists for about 200 years. To reconcile this morphological inconsistency, early comparative morphologists suggested that the mammalian middle ear was derived from elements of the jaw joint of nonmammalian amniotes. Fossils of mammalian ancestors also implied a transition in skeletal morphology that resulted in the mammalian state. During the latter half of the 20th century, developmental mechanisms controlling the formation of the jaw skeleton became the subject of studies in developmental biology and molecular genetics. Mammalian middle ear evolution can now be interpreted as a series of changes in the developmental program of the pharyngeal arches. In this review, we summarize the history of middle ear research, highlight some of the remaining problems, and suggest possible future directions. We propose that to understand mammalian middle ear evolution, it is essential to identify the critical developmental events underlying the particular mammalian anatomy and to describe the evolutionary sequence of changes in developmental and molecular terms. We also discuss the degree of consistency between the developmental explanation of the mammalian middle ear based on molecular biology and morphological changes in the fossil record. J. Exp. Zool. (Mol. Dev. Evol.) 314B:417–433, 2010. © 2010 Wiley‐Liss, Inc.
Force spectroscopy of barnase–barstar single molecule interaction
Authors: Sekatskii S. K. , Favre M. , Dietler G. , Mikhailov A. G. , Klinov D. V. , Lukash S. V. , Deyev S. M.
Published: April 2010

Results of the single molecule force spectroscopy study of specific interactions between ribonuclease barnase and its inhibitor barstar are presented. Experimental data obtained for the force loading rate ranging 2–70 nN/s are well approximated by a single straight line, from which the dissociation barrier of the width of 0.12 nm and height of 0.75–0.85×10−19 J can be inferred. The measured value of specific interaction does not depend on the NaCl concentration. This apparently contradicts the well‐known dependence of the binding energy of this pair on the salt concentration, but such a “contradiction” is explained by the insensitivity of the force spectroscopy data to the relatively long‐range electrostatic interaction. The latter essentially contributes to the value of barnase–barstar binding energy revealed by biochemical measurements, and it is exactly this electrostatic interaction which is influenced by the salt concentration. Copyright © 2010 John Wiley & Sons, Ltd.
Assessing 20th century climate–vegetation feedbacks of land‐use change and natural vegetation dynamics in a fully coupled vegetation–climate model
Authors: Strengers Bart J. , Müller Christoph , Schaeffer Michiel , Haarsma Reindert J. , Severijns Camiel , Gerten Dieter , Schaphoff Sibyll , van den Houdt Roy , Oostenrijk Rineke
Published: April 2010

This study describes the coupling of the dynamic global vegetation model (DGVM), Lund–Potsdam–Jena Model for managed land (LPJmL), with the general circulation model (GCM), Simplified Parameterizations primitivE Equation DYnamics model (SPEEDY), to study the feedbacks between land‐use change and natural vegetation dynamics and climate during the 20th century. We show that anthropogenic land‐use change had a stronger effect on climate than the natural vegetation's response to climate change (e.g. boreal greening). Changes in surface albedo are an important driver of the climate's response; but, especially in the (sub)tropics, changes in evapotranspiration and the corresponding changes in latent heat flux and cloud formation can be of equal importance in the opposite direction. Our study emphasizes that implementing dynamic vegetation into climate models is essential, especially at regional scales: the dynamic response of natural vegetation significantly alters the climate change that is driven by increased atmospheric greenhouse gas concentrations and anthropogenic land‐use change. Copyright © 2010 Royal Meteorological Society
More than symptom reduction: Changes in executive function over the course of PTSD treatment
Authors: Walter Kristen H. , Palmieri Patrick A. , Gunstad John
Published: April 2010

Persons with posttraumatic stress disorder (PTSD) have neuropsychological impairments in multiple cognitive domains, though particularly in executive function. This exploratory study examined whether these cognitive impairments were alleviated following trauma‐focused treatment. Fifteen women underwent neuropsychological testing within a week of treatment onset and approximately 3 months later. Results suggest medium‐sized improvement in multiple aspects of executive function, including tests of cognitive flexibility/set‐shifting and organization/planning. If replicated in larger samples, such findings raise the possibility that treatment may alleviate neuropsychological impairment in persons with PTSD and thus reduce risk for poor outcome.
Strategic command taking the long view for organizational success
Authors: Beatty Katherine , Quinn Laura
Published: April 2010

Organizations can best gain an advantage over their competitors by practicing strategic leadership. But how is strategic leadership accomplished, and who in an organization should be responsible for it? Strategic leadership is a complex process of thinking, acting, and influencing, and it can be exercised not just by individuals but also by teams.
Smart Hydrogels Based on Modified Gum Arabic as a Potential Device for Magnetic Biomaterial
Authors: Paulino Alexandre T. , Guilherme Marcos R. , Mattoso Luiz H. C. , Tambourgi Elias B.
Published: April 2010

By means of a conventional cross‐linking/co‐polymerization reaction of modified gum arabic (M‐GA), acrylamide (AAm), and potassium acrylate (KAAc) in the presence of magnetite (Fe3O4) nanoparticles, a magnetic field‐sensitive M‐GA‐based hydrogel (smart hydrogel) was synthesized to investigate its potential as a magnetic biomaterial and as a intelligent hydrogel. Characterizations through FT‐IR, NMR, XRD, Mössbauer, SEM, and EDX inferred that the smart hydrogel was efficiently formed. Theoretically, the smart hydrogel obtained in this work may effectively be applied as biomaterial either on remote controlled release or tissue engineering or even in other areas of science and technology.

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Microstructure and Indentation Behaviour of Polyhedral Oligomeric Silsesquioxanes‐Modified Thermoplastic Polyurethane Nanocomposites
Authors: Lach Ralf , Michler Goerg Hannes , Grellmann Wolfgang
Published: April 2010

Morphological analyses of nanocomposites based on TPU and polyhedral oligomeric silsesquioxanes (POSS) was performed using different techniques (transmission electron microscopy, small‐ and wide‐angle X‐ray scattering, differential scanning calorimetry) as a function of molecular weight of poly(ethylene glycol) (PEG) and PEG/POSS mol ratio. A strong interdependence in crystallisation behaviour between the two (POSS and the soft segments of TPU) specified to be able to crystallise in TPU/POSS was found. The mechanical properties determined by using recording microindentation techniques at room temperature were significantly improved by POSS for two material formulations.

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From a commodity to an experience: The moderating role of thematic positioning on congruity‐based product judgment
Authors: Noseworthy Theodore J. , Finlay Karen , Islam Towhidul
Published: April 2010

Research in positioning strategy suggests that a product schema, when presented in a moderately incongruent fashion, can evoke a greater degree of positive evaluation than if presented congruently with consumer expectations. This phenomenon has been coined the schema congruity effect. To date, one of the limitations of the phenomenon is that it has been applied almost exclusively to taxonomic stimuli, with little reference to thematic, eventlike stimuli. Two experiments verified that taxonomic and thematic product categories differ with respect to their unique characteristics. Consequently, despite successful replication of the schema congruity effect during taxonomic interpretation, when pushed thematically, the schema congruity effect failed to manifest. Furthermore, both experiments confirmed that, unlike taxonomic product categories that benefit from abstract and moderately incongruent positioning, thematic product categories benefit from concrete and congruent positioning. Implications for understanding the moderating role of thematic positioning on congruity‐based product evaluation as well as the differences between taxonomic and thematic stimuli are discussed. © 2010 Wiley Periodicals, Inc.
Aggregation‐Induced Emission in a Hyperbranched Poly(silylenevinylene) and Superamplification in Its Emission Quenching by Explosives
Authors: Lu Ping , Lam Jacky W. Y. , Liu Jianzhao , Jim Cathy K. W. , Yuan Wangzhang , Xie Ni , Zhong Yongchun , Hu Qin , Wong Kam Sing , Cheuk Kevin K. L. , Tang Ben Zhong
Published: April 2010

A silicon‐containing hyperbranched polymer (hb‐P1/2) with σ*–π* conjugation was prepared in a good yield and high molecular weight by rhodium‐catalyzed alkyne polyhydrosilylation of 1,2‐bis(4‐ethynylphenyl)‐1,2‐diphenylethene (1) with tris(4‐dimethylsilylphenyl)amine (2). The polymer was thermally stable, losing merely 5% of its weight when heated to ≈445 °C. Whereas hb‐P1/2 was weakly luminescent when molecularly dissolved, it became highly emissive when supramolecularly aggregated, showing an aggregation‐induced emission (AIE) phenomenon. A superamplification effect was observed when the AIE nanoaggregates were used as fluorescent chemosensor for explosive detection: the quenching efficiency was greatly increased in a nonlinear fashion with increasing quencher concentration.

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Synthesis of Prussian Blue Coordination Polymer Nanocubes via Confinement of the Polymerization Field Using Miniemulsion Periphery Polymerization (MEPP)
Authors: McHale Ronan , Ghasdian Negar , Liu Yibo , Wang Huihui , Miao Yuqing , Wang Xiaosong
Published: April 2010

Miniemulsion periphery polymerization (MEPP) has been used for the synthesis of Prussian blue (PB) nanocubes. Pentacyano ferrate functionalized surfactant in combination with a co‐surfactant containing 4‐(dimethylamino)‐pyridine (DMAP) or OH end groups in lieu of ferrate functionality (EPE‐DMAP or EPE‐OH) were used to prepare a miniemulsion system comprising 20 wt.‐% toluene and 0.5 wt.‐% total surfactant. On addition of Fe3+ to the miniemulsion, metal coordination polymerization occurred with nanocubes generated when the ratio of EPE‐Fe:EPE‐DMAP (or EPE‐OH) was 60:40 (w/w). The resulting nanocubes are apparently amorphous. Particles with irregular shape have been observed on reacting EPE‐Fe and Fe3+ directly in water, thus suggesting that confinement of the polymerization field on the periphery of the miniemulsion droplets is a primary factor in the formation of cubic structures.

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Electropolymerization of a Ruthenium(II) Bis(pyrazolyl)pyridine Complex to Form a Novel Ru‐Containing Conducting Metallopolymer
Authors: Zhu Xun Jin , Holliday Bradley J.
Published: April 2010

A new derivative of 2,6‐bis(pyrazol‐1‐yl)pyridine (bpp) symmetrically substituted with 3,4‐ethylenedioxy‐thienyl (EDOT) substituent groups, and the corresponding ruthenium(II) complex was synthesized and characterized by NMR spectroscopy, elemental analysis, mass spectrometry, and single‐crystal X‐ray diffraction. A new linear conducting metallopolymer consisting of [Ru(bpp‐(EDOT)2)(terpy)]2+ fragments was deposited directly on to electrode surfaces as a transparent, deep red film by electrochemical coupling of the pendant EDOT moieties. XPS analysis reveals that the film has the expected structure consisting of monomer repeats without degradation or loss of metal ions. Additionally, the absorption spectrum of the polymer film shows a broad absorption range from 310 to 700 nm.

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Restless legs syndrome: Evidence for nocturnal hypothalamic‐pituitary‐adrenal system activation
Authors: Schilling Claudia , Schredl Michael , Strobl Philipp , Deuschle Michael
Published: April 2010

Epidemiological studies consistently point to a relationship between restless legs syndrome (RLS) and cardiovascular disease. The mechanism underlying this association is unclear. Activation of the hypothalamic‐pituitary‐adrenal (HPA) system has been shown to contribute to the metabolic syndrome and an enhanced cardiovascular risk. We investigated cortisol levels as an indicator of HPA system activity in RLS during the nighttime, when RLS symptoms are at their maximum. We assessed nocturnal urinary cortisol excretion in 73 patients with RLS and 34 healthy controls, controlling for age and gender. Urine sampling was paralleled by polysomnographic recordings. We found significantly enhanced nocturnal cortisol excretion in RLS, demonstrating nocturnal HPA system overactivity in RLS. HPA system overactivity is a possible mechanism contributing to the enhanced load of cardiovascular disease in RLS patients. Nocturnal cortisol release showed weak correlations with some polysomnographic parameters of disturbed sleep, making a potential contribution of RLS‐induced sleep disruption to HPA system activation conceivable. © 2010 Movement Disorder Society
Synthesis and Characterization of Benzyl Methacrylate/Styrene Random Copolymers Prepared by NMP
Authors: Zhang Chi , Lessard Benoit , Maric Milan
Published: April 2010

BzMA/styrene random copolymers were synthesized in bulk (molar feed compositions fBzMA,0 = 10–90 mol‐%) at 90 °C by NMP with about 10% free SG1 relative to BlocBuilder initiator. Reactivity ratios (rBzMA = 0.86 ± 0.36, rstyrene = 0.27 ± 0.14) were comparable to those reported by conventional radical polymerization. Linear $\overline M _{\rm n} $ increase with conversion was observed up to ∼50% conversion, and all copolymers had low $\overline M _{\rm w} /\overline M _{\rm n} $ = 1.2–1.4. The $\left\langle {k_{\rm p} } \right\rangle \left\langle K \right\rangle $ ($\left\langle {k_{\rm p} } \right\rangle $ = average propagation rate constant and $\left\langle K \right\rangle $ = average equilibrium constant) exponentially increased with increasing fBzMA,0. Chain extensions with styrene at 110 °C initiated by BzMA/styrene copolymers made with fBzMA,0 <80 mol‐% were highly living while macroinitatiors with fBzMA,0 >90 mol‐% were not, based on GPC and 31P NMR results.

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Mechanical properties of glass bead‐ and wollastonite‐filled isotactic‐polypropylene composites modified with thermoplastic elastomers
Authors: Balkan Onur , Demirer Halil
Published: April 2010

Mechanical properties of the isotactic‐polypropylene/glass bead (iPP/GB) and iPP/wollastonite (iPP/W) composites modified with thermoplastic elastomers, the poly(styrene‐b‐ethylene‐co‐butylene‐b‐styrene) copolymer (SEBS) and corresponding block copolymer grafted with maleic anhydride (SEBS‐g‐MA), were investigated. An increase in toughness of iPP with the elastomers was associated with a decrease in rigidity and strength. Mechanical performance of iPP increased more with acicular W than with spherical GB due to reinforcing effect of W. Comparing the (iPP/GB)/SEBS and (iPP/W)/SEBS composites having the separate microstructure, strength and toughness values of the iPP/GB and iPP/W composites increased more with SEBS‐g‐MA at the expense of rigidity due to the core‐shell microstructure with strong interfacial adhesion. Moreover, the iPP/W composite exhibited superior mechanical performance with 2.5 and 5 vol% of SEBS‐g‐MA because of a positive synergy between the core‐shell microstructure and reinforcing effect of acicular W. The extended models revealed that the elastomer and filler particles in the (iPP/GB)/SEBS and (iPP/W)/SEBS composites acted individually due to the separate microstructure. However, the rigid GB and W particles encapsulated with the thick elastomer interlayer (R0/R1 = 0.91) in the (iPP/GB)/SEBS‐g‐MA and (iPP/W)/SEBS‐g‐MA composites acted like neither big elastomer particles nor like individual rigid particles, inferring more complicated failure mechanisms in the core‐shell composites. POLYM. COMPOS., 31:1285–1308, 2010. © 2010 Society of Plastics Engineers
Twin anemia polycythemia sequence from a prenatal perspective
Authors: Gucciardo Léonardo , Lewi Liesbeth , Vaast Pascal , Debska Marzena , De Catte Luc , Van Mieghem Tim , Done Elisa , Devlieger Roland , Deprest Jan
Published: April 2010

Objectives

To describe the prevalence, management and outcome of spontaneous twin anemia polycythemia sequence (TAPS) diagnosed in the prenatal period.

Method

Retrospective analysis of 142 consecutive monochorionic twin pregnancies not diagnosed with twin to twin transfusion syndrome. TAPS cases were identified based on the presence of discordant middle cerebral artery peak systolic velocity (MCA‐PSV) measurements and signs suggestive of a chronic intertwin transfusion imbalance: either an elevated reticulocyte count in the anemic twin or the presence of few small unidirectional anastomoses during fetoscopy or at postnatal placental examination.

Results

Three cases were identified, giving an estimated prevalence of 2%. Prenatal interventions were tailored to the characteristics of each case and consisted of intrauterine transfusion and interruption of the shared circulation by cord coagulation or laser separation.

Conclusion

In monochorionic twin pregnancies, TAPS is an uncommon prenatal finding. Nonetheless, its incidence seems high enough to recommend screening for this disease by MCA‐PSV measurements. Copyright © 2010 John Wiley & Sons, Ltd.
Uptake of prenatal diagnostic testing and the effectiveness of prenatal screening for Down syndrome
Authors: Jaques Alice M. , Collins Veronica R. , Muggli Evelyne E. , Amor David J. , Francis Ivan , Sheffield Leslie J. , Halliday Jane L.
Published: April 2010

Objectives

To map prenatal screening and diagnostic testing pathways in Victorian pregnant women during 2003 to 2004; measure the impact of prenatal diagnostic testing uptake on the effectiveness of prenatal screening for Down syndrome; and assess factors influencing uptake of diagnostic testing following screening.

Methods

State‐wide data collections of prenatal screening and diagnostic tests were linked to all Victorian births and pregnancy terminations for birth defects.

Results

Overall, 52% of women had a prenatal test (65 692/126 305); screening (44.9%), diagnostic testing (3.9%), or both (3.2%). Uptake of diagnostic testing was 71.4% (2390/3349) after an increased risk screen result, and 2.5% (1381/54 286) after a low risk result. Variation in uptake of diagnostic testing reduced the effectiveness of the screening program by 11.2%: from 87.4% (sensitivity − 125/143) to 76.2% (prenatal diagnoses of Down syndrome − 109/143). In both the increased and low risk groups, uptake was influenced by absolute numerical risk, as well as by the change in numerical risk from a priori risk.

Conclusions

This comprehensive follow‐up demonstrates clearly that numerical risk is being used to aid in decision making about confirmatory diagnostic testing. Collectively, these fundamental individual decisions will impact on the overall effectiveness of screening programmes for Down syndrome. Copyright © 2010 John Wiley & Sons, Ltd.
Three‐dimensional simulation on multilayer parison shape at pinch‐off stage in extrusion blow molding
Authors: Fukuzawa Youhei , Tanoue Shuichi , Iemoto Yoshiyuki , Kawachi Ryuichi , Tomiyama Hideki
Published: April 2010

We tried to predict the multilayer parison shape at pinch‐off stage in extrusion blow molding by nonisothermal and purely viscous non‐Newtonian flow simulation using the finite element method (FEM). We assumed the parison deformation as a flow problem. The Carreau model was used as the constitutive equation and FEM was used for calculation method. Multilayer parison used in this simulation was composed of high‐density polyethylene (HDPE) as inner and outer layers and low‐density polyethylene (LDPE) of which viscosity is five times lower than HDPE as a middle layer. We discussed multilayer parison shape in pinch‐off region. The results obtained are as follows; the parison shape of each layer was clearly visible in the pinch‐off during the mold closing. In addition, the distribution of parison thickness ratios for each layer was located for a large deformation near the pinch‐off region. The melt viscosity for each layer has an influence on the melt flow in the pinch‐off region. In a comparison with an experimental data of parison thickness ratios, the simulation results are larger than the experimental data. These simulation results obtained are in good agreement with the experimental data in consideration of the standard deviations. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers
Polymerization of ethylene by (α‐Diimine) nickel catalyst and statistical analysis of the effects of reaction conditions
Authors: Ferreira Luis Carlos , Melo Priamo Albuquerque , Crossetti Geraldo Lopes , Galland Griselda Barrera , Nele Marcio , Pinto José Carlos
Published: April 2010

This article regards the ethylene polymerization catalyzed by a nickel catalyst and activated by ethylaluminum sesquichloride (EASC). The effects of the reaction conditions [polymerization temperature, cocatalyst (EASC) concentration, and ethylene concentration] on the average molecular weights of the final polymers and reaction yields were evaluated with the help of empirical statistical models. It is shown that reaction temperature and cocatalyst (EASC) concentration exert the most important effects on average molecular weights and catalyst activity. The polydispersities of the obtained polyethylenes are larger than the polydispersities of polyethylenes obtained with typical Brookhart catalysts. The analysis of polymer branching frequencies shows new types of short branching and significant amounts of long branches, which may explain the relatively large polydispersities of the obtained polymer samples. POLYM. ENG. SCI., 50:1797–1808, 2010. © 2010 Society of Plastics Engineers
Polymer electrolyte membranes based on p‐toluenesulfonic acid doped poly(1‐vinyl‐1,2,4‐triazole): Synthesis, thermal and proton conductivity properties
Authors: Özden Şehmus , Çeli̇k Sevi̇m Ünügür , Bozkurt Ayhan
Published: April 2010

Throughout this work, the synthesis, thermal as well as proton conducting properties of acid doped heterocyclic polymer were studied under anhydrous conditions. In this context, poly(1‐vinyl‐1,2,4‐triazole), PVTri was produced by free radical polymerization of 1‐vinyl‐1,2,4‐triazole with a high yield. The structure of the homopolymer was proved by FTIR and solid state 13C CP‐MAS NMR spectroscopy. The polymer was doped with p‐toluenesulfonic acid at various molar ratios, x = 0.5, 1, 1.5, 2, with respect to polymer repeating unit. The proton transfer from p‐toluenesulfonic acid to the triazole rings was proved with FTIR spectroscopy. Thermogravimetry analysis showed that the samples are thermally stable up to ∼250 °C. Differential scanning calorimetry results illustrated that the materials are homogeneous and the dopant strongly affects the glass transition temperature of the host polymer. Cyclic voltammetry results showed that the electrochemical stability domain extends over 3 V. The proton conductivity of these materials increased with dopant concentration and the temperature. Charge transport relaxation times were derived via complex electrical modulus formalism (M*). The temperature dependence of conductivity relaxation times showed that the proton conductivity occurs via structure diffusion. In the anhydrous state, the proton conductivity of PVTri1PTSA and PVTri2PTSA was measured as 8 × 10−4 S/cm at 150 °C and 0.012 S/cm at 110 °C, respectively. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1016–1021, 2010
Poly(bis‐2,2,2‐trifluoroethoxymethyl oxetane): Multiple crystal phases, crystallization‐induced surface topological complexity and enhanced hydrophobicity
Authors: Zheng Ying , Zhang Wei , Gupta Murari , Kankanala Spandana , Marks Carolyn , Carpenter Everett , Carroll Kyler , Wynne Kenneth J.
Published: April 2010

Semicrystalline poly(bis‐trifluoroethoxymethyl)oxetane, P(B‐3FOx), was prepared by cationic ring‐opening polymerization at −5 °C with Mn up to 21 kDa. Differences in cooling rates from the melt have substantial effects on crystal phase, percent crystallinity, surface topography, and wetting behavior. DSC and WAXD show that cooling from the melt at slow rates (<5 °C/min) gives α‐P(B‐3FOx) with ΔHf = 22–27 J/g. Quenching from the melt results in β‐P(B‐3FOx) for which a mesophase structure is suggested. β‐P(B‐3FOx) melts at 53 °C followed by recrystallization to α‐P(B‐3FOx). Solution casting from THF results in third phase, γ‐P(B‐3FOx). TM‐AFM and SEM imaging for α‐P(B‐3FOx) showed that cold crystallization at 25 °C brought about increased crystallinity and surface topologies characterized by sharp asperities and lath‐shaped crystals. Spontaneous surface roughening of α‐P(B‐3FOx) results in a discontinuous three‐phase contact line with water and an increase in water sessile drop contact angle from 106° to 136°. The ∼30° increase in water contact angle was attributed primarily to a topological change from a relatively smooth surface (Wenzel state) to an asperity‐rich surface yielding a discontinuous three‐phase contact line (composite of Wenzel and Cassie‐Baxter state). The oleophobicity for this polymer, which contains only a single CF3 end group on each side chain, compares favorably with more highly fluorinated acrylates. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1022–1034, 2010
The origin of DC electrical conduction and dielectric relaxation in pristine and doped poly(3‐hexylthiophene) films
Authors: Singh Ramadhar , Singh Rajiv K. , Kumar Jitendra , Kant Rama , Kumar Vikram
Published: April 2010

We present here the evidence for the origin of dc electrical conduction and dielectric relaxation in pristine and doped poly(3‐hexylthiophene) (P3HT) films. P3HT has been synthesized and purified to obtain pristine P3HT polymer films. P3HT films are chemically doped to make conducting P3HT films with different conductivity level. Temperature (77–350 K) dependent dc conductivity (σdc) and dielectric constant (ε′(ω)) measurements on pristine and doped P3HT films have been conducted to evaluate dc and ac electrical conduction parameters. The relaxation frequency (fR) and static dielectric constant (ε0) have been estimated from dielectric constant measurements. A correlation between dc electrical conduction and dielectric relaxation data indicates that both dc and ac electrical conductions originate from the same hopping process in this system. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1047–1053, 2010
Hydrophobically modified poly(vinyl alcohol) using alkoxy‐substituted methyl gallate: Synthesis and rheology
Authors: Shedge Aarti S. , Wadgaonkar Prakash P. , Lele Ashish K. , Badiger Manohar V.
Published: April 2010

Hydrophobically modified poly(vinyl alcohol) (HMPVA) polymers were synthesized by potassium t‐butoxide‐catalyzed reaction of PVA with methyl 3,4,5‐tris(n‐octyloxy) benzoate (MGC8)/3,4,5‐tris(n‐dodecyloxy) benzoate (MGC12) and 1,3‐propane sultone. The concentration of 1,3‐propane sultone was kept constant at 10 mol % and that of MGC8 (2, 3, and 4 mol %)/MGC12 (2 and 3 mol %) was varied to obtain HMPVAs with different hydrophobic contents. The incorporation of MGC8/MGC12 and 1,3‐propane sultone onto HMPVA was confirmed by NMR spectroscopy. Rheological properties of aqueous solutions also confirmed the presence of hydrophobic and charged functional groups on HMPVAs. In the semidilute regime, the specific viscosity of HMPVAs followed concentration scaling that is typical of polyelectrolytes. At higher concentrations, the HMPVA solutions with 3 and 4 mol % of MGC8 exhibited large increase in specific viscosity. Oscillatory experiments on these solutions exhibited gel‐like behavior at polymer concentrations of 40–50 g/L. Confocal microscopy images of HMPVA with 4 mol % of MGC8 clearly indicated the existence of microgels. The tendency of formation of microgels further increased with increasing chain length of the hydrophobe, that is, with MGC12. These samples exhibited rheological behavior that is typical of soft solids and was therefore probed by the strain‐rate frequency superposition technique reported recently in the literature. HMPVAs with improved rheological properties show potential applications as thickeners in cosmetic creams, lotions and as drug carriers in pharmaceutical formulations. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1054–1063, 2010
Nonisothermal crystallization kinetics of poly (phenylene sulphide) in composites with a liquid crystalline polymer
Authors: Kalkar Arun K. , Deshpande Vineeta D. , Kulkarni Milind J.
Published: April 2010

The article deals with the melting and nonisothermal crystallization behavior of neat poly (phenylene sulphide) (PPS) and its composites with a thermotropic liquid crystalline polymer (TLCP)—Vectra A950, prepared by melt mixing and probed by differential scanning calorimetry. The various macrokinetic models namely, the Ozawa, the modified Avrami, the Tobin, and the Mo models were applied to describe the crystallization kinetics under nonisothermal conditions. The kinetic crystallizabilty of PPS/TLCP composites calculated using the approach of Ziabicki varies depending on these two composite composition‐induced effects. Similarly Mo model predicts that to obtain a higher degree of crystallizabilty for PPS/TLCP composites, a higher cooling rate should be used. The effective energy barrier based on the differential isoconversional method of Friedman is found to be an increasing function of relative degree of melt conversion. The effect is explained in terms of nucleation theory proposed by Wunderlich to crystallization of polymers. The Lauritzen–Hoffman parameters are estimated using G = 1/t0.5 effective activation energy equation proposed by Vyazovkin and Sbirrazzuoli. The Kg values estimated from latter equations are more comparable with values obtained using isothermal crystallization data than 1/t0.5 method. Furthermore, the kinetic analysis using this equation shows a regime transition from regime II to regime III for 100/00, 90/10, 80/20 PPS/TLCP composites, basically attributed to reduced mobility of PPS chains in composites. This regime II to III transition is accompanied by a morphological transition from defective spherulitic sheaf‐like structures to ordered sheaf‐like structures. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1070–1100, 2010
Stability of hierarchical lamellar morphologies formed in ABC star triblock copolymers
Authors: Xu Yuci , Li Weihua , Qiu Feng , Zhang Hongdong , Yang Yuliang , Shi An‐Chang
Published: April 2010

The stability of hierarchical lamellar morphologies formed in ABC star triblock copolymers, is studied using the self‐consistent mean‐field theory. The hierarchical lamellae consist of repeating period of the largest block A‐formed layer and B/C coformed layer where B and C domains are arranged alternatively. An angle, which is used to characterize the shifting magnitude between two neighbor B/C coformed layers, varies from 0 to 180 degrees. By comparing the free energy among the lamellar morphologies with various shift angle, their relative stability is analyzed. Our results show that the morphology with larger shift has lower entropic energy and higher internal energy. In general, the morphology with the largest shift of 180‐degree is stable compared with those with smaller shift as the entropic energy dominates the internal energy. However, the relative stability can be tuned by the interactions among the three components as well as their relative compositions. PACS numbers: 61.25.Hq, 64.60.Cn, 64.75.+g. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1001–1109, 2010
Synthesis and characterization of grafted/crosslinked proton conducting membranes based on amphiphilic PVDF copolymer
Authors: Roh Dong Kyu , Ahn Sung Hoon , Seo Jin Ah , Shul Yong Gun , Kim Jong Hak
Published: April 2010

A novel graft copolymer consisting of a poly(vinylidene fluoride‐co‐chlorotrifluoroethylene) backbone and poly(glycidyl methacrylate) side chains, that is, P(VDF‐co‐CTFE)‐g‐PGMA, was synthesized through atom transfer radical polymerization (ATRP) using CTFE units as a macroinitiator. Successful synthesis and microphase‐separated structure of the polymer were confirmed by 1H NMR, FTIR spectroscopy, and TEM. As‐synthesized P(VDF‐co‐CTFE)‐g‐PGMA copolymer was sulfonated by sodium bisulfite, followed by thermal crosslinking with sulfosuccinic acid (SA) via the esterification to produce grafted/crosslinked polymer electrolyte membranes. The IEC values continuously increased with increasing SA content but water uptake increased with SA content up to 10 wt %, above which it decreased again as a result of competitive effect between crosslinking and hydrophilicity of membranes. At 20 wt % of SA content, the proton conductivity reached 0.057 and 0.11 S/cm at 20 and 80 °C, respectively. The grafted/crosslinked P(VDF‐co‐CTFE)‐g‐PGMA/SA membranes exhibited good mechanical properties (>400 MPa of Young's modulus) and high thermal stability (up to 300 °C), as determined by a universal testing machine (UTM) and TGA, respectively. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1110–1117, 2010
Seeking informed consent to Phase I cancer clinical trials: identifying oncologists' communication strategies
Authors: Brown Richard , Bylund Carma L. , Siminoff Laura A. , Slovin Susan F.
Published: April 2010

Purpose: Phase I clinical trials are the gateway to effective new cancer treatments. Many physicians have difficulty when discussing Phase I clinical trials. Research demonstrates evidence of suboptimal communication. Little is known about communication strategies used by oncologists when recruiting patients for Phase I trials. We analyzed audio recorded Phase I consultations to identify oncologists' communication strategies.

Patients and Methods: Subjects were consecutive cancer patients from six medical oncologists attending one of three outpatient clinics at a major Cancer Center in the United States. Sixteen patients signed informed consent for audio recording of their consultations in which a Phase I study was discussed. These were transcribed in full and analyzed to identify communication strategies.

Results: Six communication themes emerged from the analysis: (1) orienting, (2) educating patients, (3) describing uncertainty and prognosis, (4) persuading, (5) decision making, and (6) making a treatment recommendation. As expected, although there was some common ground between communication in Phase I and the Phase II and III settings, there were distinct differences.

Conclusions: Oncologists used persuasive communication, made explicit recommendations, or implicitly expressed a treatment preference and were choice limiting. This highlights the complexity of discussing Phase I trials and the need to develop strategies to aid oncologists and patients in these difficult conversations. Patient centered communication that values patient preferences while preserving the oncologist's agenda can be a helpful approach to these discussions. Copyright © 2010 John Wiley & Sons, Ltd.