bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of melamine in royal jelly and lyophilized powder using ultrasonically assisted extraction by ion‐pair HPLC with UV detection
Authors: Zhou Jinhui , Zhao Jing , Xue Xiaofeng , Chen Fang , Zhang Jinzhen , Li Yi , Wu Liming , Chen Lanzhen
Published: December 2009

A rapid method for the analysis of melamine in royal jelly (RJ) and RJ lyophilized powder (RJLP) was developed using ion‐pair RP‐HPLC coupled with UV detector. The method utilized an optimized buffer system to avoid the elution of melamine near the column void volume and improve retention of melamine in a generic C8 chromatographic column. In addition, sample preparation included deproteination, ultrasonic‐assisted extraction, and cleanup on a mixed‐mode cation exchange extraction cartridge. The extraction procedure was optimized with regard to the amount of extraction solvent and the duration of sonication for RJ and RJLP samples. The following criteria were used to validate the HPLC–UV detection method: selectivity, linearity, precision, LOD, and LOQ. Correlation coefficient was higher than 0.999 by applying the linear regression model based on the least square method with a weighting factor (1/x). Precision was evaluated as repeatability and intermediary precision with RSD of less than 15%. The mean percentage recoveries of melamine were varied from 72.5 to 90.5% for RJ and RJLP. This approach will be of particular utility for the evaluation of melamine residue level and routine monitoring of melamine in RJ and RJLP samples.
SLC26A4 genotype, but not cochlear radiologic structure, is correlated with hearing loss in ears with an enlarged vestibular aqueduct
Authors: King Kelly A. , Choi Byung Yoon , Zalewski Christopher , Madeo Anne C. , Manichaikul Ani , Pryor Shannon P. , Ferruggiaro Anne , Eisenman David , Kim H. Jeffrey , Niparko John , Thomsen James , Butman John A. , Griffith Andrew J. , Brewer Carmen C.
Published: December 2009

Objectives/Hypothesis:

Identify correlations among SLC26A4 genotype, cochlear structural anomalies, and hearing loss associated with enlargement of the vestibular aqueduct (EVA).

Study Design:

Prospective cohort survey, National Institutes of Health, Clinical Center, a federal biomedical research facility.

Methods:

Eighty‐three individuals, 11 months to 59 years of age, with EVA in at least one ear were studied. Correlations among pure‐tone hearing thresholds, number of mutant SLC26A4 alleles, and the presence of cochlear anomalies detected by computed tomography or magnetic resonance imaging were examined.

Results:

Linear mixed‐effects model indicated significantly poorer hearing in ears with EVA in individuals with two mutant alleles of SLC26A4 than in those with EVA and a single mutant allele (P = .012) or no mutant alleles (P = .007) in this gene. There was no detectable relationship between degree of hearing loss and the presence of structural cochlear anomalies.

Conclusions:

The number of mutant alleles of SLC26A4, but not the presence of cochlear anomalies, has a significant association with severity of hearing loss in ears with EVA. This information will be useful for prognostic counseling of patients and families with EVA. Laryngoscope, 2010
Novel Shape‐Memory Materials Based on Potato Starch
Authors: Véchambre Cyril , Chaunier Laurent , Lourdin Denis
Published: December 2009

Shape‐memory properties such as shape fixity and recovery ratio of amorphous starch‐based materials extruded under normal conditions were evaluated for the case of single and cyclic recovery processing. This study focused on the effect of moisture as a stimulus for the activation of recovery. A high recovery ratio (Rr > 90%) was obtained at high relative humidity, at deformation ratios up to 200%. In the case of plasticized starch with a glycerol content of 10%, the recovery ratio was close to 50% because crystallization limited the shape recovery. Results were compared to those obtained with synthetic or bio‐based shape‐memory polymers such as semi‐crystalline PU or PLAGC. Efficient shape memory properties for a non‐modified biopolymer are highlighted in this study.

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How price increases affect future purchases: The role of mental budgeting, income, and framing
Authors: Homburg Christian , Koschate Nicole , Totzek Dirk
Published: December 2009

This article suggests that mental budgeting processes provide afurther understanding of how and to what degree price increases negatively affect a customer's future purchase behavior in a particular category of expenses. Furthermore, the authors analyze how customer income and different price presentation tactics alter this reaction. Results of two experimental studies using both students and non‐students show that customer income attenuates the negative effect of a price increase on the likelihood of a future purchase in a particular expense category. As an underlying mechanism, the influence of customer income on future purchase behavior is partially mediated by the degree to which customers engage in mental budgeting. Moreover, mental budgeting strengthens the negative effect of a price increase on a future purchase in the same category of expenses, whereas it does not alter the effect of a price increase on a future purchase in another category. Finally, the framing of a price increase as a percentage versus in absolute terms leads to a lower likelihood of a future category purchase. © 2009 Wiley Periodicals, Inc.
Salespersons' self‐monitoring: Direct, indirect, and moderating effects on salespersons' organizational citizenship behavior
Authors: Bande Vilela Belén , Varela González José Antonio , Fernández Ferrín Pilar
Published: December 2009

Research into self‐monitoring (SM) confirms that people differ when it comes to how much they observe, regulate, and control themselves in certain social settings and interpersonal relationships. Research also shows that high self‐monitors, as opposed to low self‐monitors, perform better in boundary‐spanning positions that require good communication skills. Therefore, it is a matter of interest to analyze the effects of SM on salespeople's behavior, and on organizational citizenship behavior (OCB) in particular. It has been proven that this behavior affects the performance of organizations and influences supervisors' evaluations of subordinates. Although a number of studies examine the antecedents of OCB, certain relationships have yet to be looked at. This study proposes and tests a model stating that salespersons' OCB is determined by salespersons' SM, with this relationship being mediated by salespersons' person–organization (PO) fit and job satisfaction. This study also analyzes the moderating effect of salespersons' SM on PO fit to job satisfaction relationships, as well as on job satisfaction to OCB relationships. Data collected from 122 supervisor–salesperson dyads in 35 companies across 9 different sectors confirm the proposed model. In fact, the results show that SM, both directly and indirectly, has a positive effect on OCB due to the way in which it influences salespersons' PO fit and job satisfaction. The results also confirm the moderating role of SM in the relationships between job satisfaction and OCB, and between PO fit and job satisfaction. Certain implications of this study, as well as directions for future research, are also addressed. © 2009 Wiley Periodicals, Inc.
Price setting in Hungary—a store‐level analysis
Authors: Gábriel Péter , Reiff Ádám
Published: December 2009

This paper uses Hungarian micro‐CPI data between December 2001 and June 2007 to provide descriptive statistics of store‐level pricing practices in Hungary. First we present simple descriptive statistics about the frequency and average size of price changes, and compare it with similar statistics from other countries. Then we decompose the observed variations in the inflation rate to variations in frequencies and sizes. Finally, we estimate the inflation effects of three general VAT‐rate changes during our sample period. Copyright © 2009 John Wiley & Sons, Ltd.
Compact rectangular slot antenna with a novel coplanar waveguide fed diamond patch for ultra wideband applications
Authors: Koohestani Mohsen , Golpour Mohsen
Published: December 2009

This letter presents a rectangular slot antenna with a novel coplanar waveguide fed diamond patch covering frequency range from 2.27 to 10.63 GHz based on S11 < −10 dB, 129%. The fabricated antenna has a small size as high as 42 × 42 mm2. The measured results are in good agreement with simulation results. The measured radiation patterns are nearly omni‐directional over the most of the frequency bandwidth. The antenna gain ranges from 1.6 to 7.6 dBi. The simple structure, compact size, and good characteristics make the antenna easy to use in commercial ultra wideband systems. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 331–334, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24899
Compact wideband multilayer microstrip coupled lines bandpass filter for X‐band application
Authors: Adam Helmi , Ismail Alyani , Mahdi Mohd Adzir
Published: December 2009

A wideband bandpass filter for X‐band application using multilayer microstrip coupled lines is presented in this article. Strong coupling required for wideband filter is realized by arranging multiple layers of microstrip lines on two different dielectric substrates and by overlapping these lines. The filter is fabricated on 0.254 mm thickness R/T Duroid 6010 and R/T Duroid 5880 with dielectric constant 10.2 and 2.2, respectively, by using standard photolithography process. Good results are obtained where the frequency responses exhibit that the filter successfully covers whole X‐band frequencies by producing 44% bandwidth at 10.2 GHz center frequency with fifth‐order Chebyshev response. Measured responses show good agreement with the simulated responses. The measured insertion loss for the multilayer filter is better than 2.5 dB, and the passband return loss is better than −12.4 dB. ©2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 448–450, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.24916
Integrated wide–narrow band antenna for multiband applications
Authors: Ebrahimi E. , Hall P. S.
Published: December 2009

In this article, a novel integration concept is introduced for multiband antennas. An integrated wide–narrow band antenna is presented, which is composed of a shorted microstrip patch integrated to a coplanar waveguide fed ultrawideband monopole antenna. The patch is printed on the reverse side of the substrate using the monopole antenna as a ground plane. A prototype of the antenna is fabricated and verified. This antenna adds the possibility to operate in two of different standards or frequency bands at any given time. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 425–430, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24926
Design and implementation of a high‐performance V‐band CMOS bandpass filter
Authors: Chang Jin‐Fa , Lin Yo‐Sheng
Published: December 2009

In this article, we demonstrate a low‐insertion‐loss V‐band (50–75 GHz) bandpass filter with two finite transmission zeros by standard 0.13 μm CMOS technology. The proposed filter architecture has the following feature: the low‐frequency transmission‐zero and the high‐frequency transmission‐zero can be tuned by the series‐feedback capacitorCsand the parallel‐feedback capacitorCp, respectively. Besides, low‐insertion‐loss is achieved by adopting thick microstrip‐line (MSL) with optimized ground‐plane pattern as the needed inductors to minimize the metal and substrate loss. This filter achieved insertion‐loss (1/S21) lower than 3 dB over the frequency range of 52.2–76.7 GHz, input return loss (S11) better than −10 dB over the frequency range of 50.2–80.6 GHz, and output return loss (S22) better than −10 dB over the frequency range of 50.2–77.3 GHz. The minimum insertion‐loss was 2.18 dB at 63.5 GHz, an excellent result for a V‐band CMOS bandpass filter. The chip area was only 0.466 × 0.307 mm2, i.e., 0.143 mm2, excluding the test pads. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 309–316, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24935
Aperture efficiency analysis of reflectarray antennas
Authors: Yu Ang , Yang Fan , Elsherbeni Atef Z. , Huang John , Rahmat‐Samii Yahya
Published: December 2009

In the design procedure of a reflectarray antenna system, the aperture efficiency needs to be first analyzed to forecast the system performance. This article investigates the effects of the reflectarray configuration parameters on the antenna aperture efficiency. A general approach is introduced to calculate the spillover efficiency of a reflectarray with arbitrarily shaped aperture and feed scheme. Meanwhile, the illumination efficiency of the reflectarray is analyzed with a unified set of equations. On the basis of these derivations, parametric studies are performed to provide design guidelines for optimizing the aperture efficiency of reflectarray antennas. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 364–372, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24949
Design of WiFi/WiMAX dual‐band E‐shaped patch antennas through cavity model approach
Authors: Hsu Heng‐Tung , Kuo Fang‐Yao , Lu Ping‐Hung
Published: December 2009

The design of dual‐band, single patch microstrip antenna covering 2.4 and 3.5 GHz for WiFi and WiMAX applications based on E‐shaped patch is presented. Although cavity model analysis is included in the design procedure, the slotted configuration is treated as the perturbed cavity to characterize the resonant frequencies of corresponding modes. Additionally, the feed point position is determined through the field distribution resulted from the modal analysis. A new equivalent circuit model based on the coupled resonators theory is proposed for analysis purposes. The relationship between cavity model analysis and antenna resonances is further evidenced by the surface current distributions on the conductors. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 471–474, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24954
Not just cattle: Cranial perforations revisited
Authors: Fabiš Marian , Thomas Richard
Published: December 2009

The phenomenon of perforated cattle skulls is well known to archaeozoologists. It is a condition that has not only been reported during routine faunal analyses but, unusually for animal palaeopathological studies, it has also been the subject of dedicated research papers. A revolutionary moment in the understanding of this anomaly came with its detection in the skull of a European bison. As a result of this discovery, a developmental disorder of genetic origin is now accepted as the most probable cause. In this paper, it is suggested that the perforations are caused by a developmental disorder that is expressed during the pneumatisation of the frontal, parietal and occipital bones in animals with a large sinus frontalis. The first published example of this condition in pig supports this hypothesis. It is argued that the anomaly is a hereditary trait caused by a recessive gene, the phenotypic expression of which only appears in homozygous recessive individuals. Higher incidences of this condition in past cattle and pig populations in certain places at times, may therefore testify to the occurrence of population bottlenecks and/or inbreeding practices. Copyright © 2009 John Wiley & Sons, Ltd.
Preparation and characterization of poly(2‐hydroxyethylme thacrylate)‐b‐P(N‐phenylmaleimide)‐ZnO and poly(2‐hydroxy ethylmethacrylate)‐b‐P(styrene)‐ ZnO micro/nanostructures: micro/nanocomposite particles with core‐shell morphology
Authors: Pizarro Guadalupe del C. , Marambio Oscar G. , Jeria‐Orell Manuel , Rivas Bernabé L. , Habicher Wolf D.
Published: December 2009

The present work reports the incorporation of the ZnO doped diblock copolymer matrix and its conversion into a self‐assembled structure. The diblock P(HEMA)80‐b‐P(N‐PhMI)20 and P(HEMA)90‐b‐P(St)10 copolymers consist of a majority (HEMA) and minority (N‐PhMI or St) block. The copolymers were synthesized with a block repeat unit ratio by atom‐transfer radical polymerization (ATRP) using a poly(2‐hydroxyethylmethacrylate)‐Cl/CuBr/bipyridine initiating system. The P(HEMA)‐Cl was prepared by reverse ATRP1. The average theoretical number molecular weight (Mn,th) was calculated from the feed capacity. The composite of the inorganic nanoparticles was achieved at room temperature in the liquid phase, using ZnCl2 precursor dopant and wet chemical processing to convert to ZnO nanoparticle films. Thermal characterization was performed using differential scanning calorimetry (DSC) and thermogravimetry (TG). The proton/area relationship confirmed the block copolymer compositions calculated by elemental analysis, consisting of a majority and minority blocks. Morphology properties of the polymer samples were investigated by scanning electron microscopy (SEM). The microphotographs of the film's surfaces show that the film's upper surfaces were generally smooth with ordered structure morphology. FT‐IR spectroscopy confirmed the association of the ZnCl2 precursor with the majority block and the formation of ZnO, the white SEM showed the morphology of ZnO nanoparticles' films when the surface relief changes principally due to surface loss rather than its orientation. Copyright © 2009 John Wiley & Sons, Ltd.
Thiotepa/topotecan/carboplatin with autologous stem cell rescue in recurrent/refractory/poor prognosis pediatric malignancies of the central nervous system
Authors: Gilheeney Stephen W. , Khakoo Yasmin , Souweidane Mark , Wolden Suzanne , Boulad Farid , Dunkel Ira J.
Published: December 2009

Background

Thiotepa and carboplatin are known to be active in central nervous system tumors. Topotecan potentiates the anti‐cancer effects of alkylators and crosses the blood–brain barrier. We present ten patients with recurrent or progressive central nervous system malignancies treated on a myeloablative regimen using these drugs.

Methods

Treatment included: Thiotepa 300 mg/m2 on days −8, −7, and −6; topotecan 2 mg/m2 on days −8, −7, −6, −5, and −4; and carboplatin ∼500 mg/m2 (Calvert formula—area under the curve = 7) on days −5, −4, and −3. Stem cell rescue was on day 0.

Results

Age at study entry ranged from 2.5 to 20 years old (median age 8.7 years). Five had medulloblastoma (MB), four had high grade glioma (HGG), and one had trilateral retinoblastoma/pineoblastoma (tRB/PB). Prior treatment for all patients included surgery and chemotherapy (1–7 regimens, median 2). Nine patients received radiotherapy; one patient did not receive radiotherapy pre‐study. Three patients had residual disease at the time of transplant. There were two toxic deaths. Four patients are event‐free survivors at a median of 6 years (range 2.8–7.6 years) after treatment including 2/5 MB patients, 1/4 HGG patients, and the tRB/PB patient. Four of the seven patients with no evidence of disease/minimal residual disease status at the time of stem cell rescue are long‐term survivors versus 1/3 with measurable disease.

Conclusion

Thiotepa/topotecan/carboplatin may help consolidate remission of poor prognosis pediatric central nervous system tumors. Diagnosis and extent of disease prior to stem cell rescue may have an impact on outcome. Pediatr Blood Cancer 2010;54:591–595. © 2009 Wiley‐Liss, Inc.
Pseudometastasis secondary to histoplasmosis infection: False‐positive PET/CT findings
Authors: Perko Ross , Messinger Yoav , Moertel Christopher
Published: December 2009

Positron emission computed tomography (PET)/CT is a common modality used in the workup of neoplastic conditions. However, false‐positive results may be produced by underlying infectious processes. We report two cases of false‐positive PET/CT studies secondary to histoplasmosis infections in both a pediatric and a young adult patient. After the diagnoses, one patient was observed with no therapy and the other received a complete course of itraconazole. In both cases biopsy results were positive for fungal elements consistent with histoplasmosis. Both patients were successfully managed and have had follow‐up histoplasmosis titers that reveal resolving infections. Pediatr Blood Cancer 2010;54:621–623. © 2009 Wiley‐Liss, Inc.
Mefloquine prescriptions in the presence of contraindications: prevalence among US military personnel deployed to Afghanistan, 2007
Authors: Nevin Remington L.
Published: December 2009

Purpose

Contraindications to mefloquine use include a history of certain prevalent neuropsychiatric disorders, which are thought to increase the risk of severe adverse events including anxiety, paranoia, depression, hallucinations, psychosis, and possibly suicide. Within the US military, the continued availability and use of mefloquine is subject to administrative policies dating to 2002 that require clinicians to exercise added caution during prescribing. This analysis was performed to quantify the effectiveness of these policies in ensuring health care provider compliance with package insert prescribing guidance.

Methods

A previously identified cohort consisting of 11 725 active duty US military personnel, among whom 1127 (9.6%) had contraindications to mefloquine use identified through medical surveillance and pharmaceutical databases, was examined to identify individuals receiving prescriptions for mefloquine in the 45 days prior to a combat deployment in 2007.

Results

Among the 11 725 cohort members, 4505 (38.4% of the cohort) received a prescription for mefloquine. Among the 1127 cohort members with contraindications, 155 (1.3% of the cohort) were prescribed mefloquine, comprising 13.8% of those with contraindications.

Conclusions

Despite the longstanding administrative policies meant to reduce such events, approximately one in seven individuals with neuropsychiatric contraindications received a prescription for mefloquine prior to a recent combat deployment, significantly increasing the risk of subsequent adverse events. Given the prevalence of neuropsychiatric disorders among US military personnel and the continued availability of mefloquine, additional study is recommended to describe and quantify the nature and extent of mefloquine‐associated adverse events experienced among this group. Published in 2009 by John Wiley & Sons, Ltd.
Thiazolidinediones and the risk of incident strokes in patients with type 2 diabetes: a nested case‐control study
Authors: Azoulay Laurent , Schneider‐Lindner Verena , Dell'Aniello Sophie , Filion Kristian B. , Suissa Samy
Published: December 2009

Purpose

To determine whether the use of thiazolidinediones (TZDs) decreases the risk of incident strokes in patients with type 2 diabetes.

Methods

We conducted a nested case‐control study within a population‐based cohort from the UK General Practice Research Database (GPRD). The cohort comprised patients over the age of 40 who were prescribed a first oral hypoglycemic agent between 1 January 1988 and 30 June 2008. Cases included all subjects who experienced a first stroke during follow‐up. Up to 10 controls were matched to each case on age (±2 years), sex, date of cohort entry (±1 year), and duration of follow‐up. Rate ratios (RRs) of stroke associated with TZD use, including rosiglitazone and pioglitazone, relative to combinations of other oral hypoglycemic agents, were estimated using conditional logistic regression.

Results

The cohort comprised 75 717 users of oral hypoglycemic agents, of whom 2417 had a stroke during follow‐up. The rate of stroke in users of TZDs given as monotherapy (RR: 1.20, 95%CI: 0.77, 1.86) or in combination with other oral hypoglycemic agents (RR: 0.78, 95%CI: 0.58, 1.04) was not lower than combinations of other oral hypoglycemic agents. The RRs were similar for rosiglitazone and pioglitazone.

Conclusions

The results of this study indicate that TZDs do not appear to decrease the incidence of first strokes. Copyright © 2009 John Wiley & Sons, Ltd.
Congenital abnormalities in children of 43 pregnant women who attempted suicide with large doses of nitrazepam
Authors: Gidai János , Ács Nándor , Bánhidy Ferenc , Czeizel Andrew E
Published: December 2009

Objective

To evaluate the teratogenic effect of very large doses of nitrazepam in children born to pregnant women who attempted suicide and to check the feasibility of self‐poisoning pregnant women model.

Design and setting

Comparative analysis of exposed children and their unexposed sibs born to the same mothers who attempted suicide during the study pregnancy and admitted to the toxicological inpatients clinic, Budapest, 1960–1993.

Study participants

Of 1044 pregnant women who attempted suicide, 107 (10.3%) used large doses of nitrazepam alone or combination with other drugs, and 43 delivered live‐born babies, these exposed children were evaluated.

Main outcomes measures

Structural birth defects, i.e., congenital abnormalities (CAs), pregnancy age at delivery, and birth weight.

Results

The mean dose of nitrazepam used for suicide attempt was 204 mg. Of 43 exposed children, 13 (30.2%) were affected with CAs, while of their 29 sib controls, 3 (10.3%) (OR with 95%CI: 3.8, 1.0–14.6). Most CAs in exposed children were mild and belonged to the deformation type. The mean pregnancy age was shorter.

Conclusions

The very large doses of nitrazepam used for suicide attempt during pregnancy resulted in a high rate of CAs which may be connected with the disruption of protein metabolism in fetal mesenchyma. The self‐poisoning pregnant women model is feasible for the evaluation of teratogenic effect of drugs. Copyright © 2009 John Wiley & Sons, Ltd.
Nanostructured thermosets from self‐assembled amphiphilic block copolymer/epoxy resin mixtures: effect of copolymer content on nanostructures
Authors: Blanco Miren , López Marta , Kortaberria Galder , Mondragon Iñaki
Published: December 2009

Nanostructure formation in thermosets can allow the design of materials with interesting properties. The aim of this work was to obtain a nanostructured epoxy system by self‐assembly of an amphiphilic diblock copolymer in an unreacted epoxy/amine mixture followed by curing of the matrix. The copolymer employed was polystyrene‐block‐poly(methyl methacrylate) (PS‐b‐PMMA). The thermoset system, formed by a diglycidyl ether of bisphenol A‐type epoxy resin and diaminodiphenylmethane hardener, was chosen to ensure the miscibility of most of the PMMA block until matrix gelation. Transparent materials with microphase‐separated domains were obtained for copolymer contents lower than 40 wt%. In systems containing 20 and 30 wt% block copolymer, the PS block formed spherical micelles or worm‐like structures before curing, which were stabilized through curing by the more compatible PMMA block phase. Nanostructured thermoset systems were successfully synthesized for self‐assembled amphiphilic block copolymer–epoxy/amine mixtures for copolymer contents lower than 40 wt%. Copyright © 2009 Society of Chemical Industry
Solution properties of polyaniline
Authors: Yılmaz Faris , Küçükyavuz Zuhal
Published: December 2009

Solution properties of polyaniline (PANI) synthesized at various temperatures were studied using static light scattering (SLS), intrinsic viscosity, and dynamic light scattering (DLS). We demonstrated that average radius of gyration 〈Rg〉, intrinsic viscosity [η], and average hydrodynamic radius 〈RH〉, of polyaniline molecules in dilute N‐methyl‐2‐pyrrolidinone (NMP) solutions increased with decreasing synthesis temperatures, i.e.; increasing molecular weight. SLS data demonstrate that second virial coefficient (A2) decreased with increasing particle sizes suggesting that solubility of PANI in NMP decreased with increasing particle sizes. We also find that the polymers extend as the polymer concentration is lowered and that the increase in the hydrodynamic radius can be expressed by a power law of the electrostatic screening length. This behavior is typical of polyelectrolytes in dilute solution, providing a basis for understanding the conformation changes of this metallic polymer in solution. Copyright © 2009 Society of Chemical Industry
A highly controllable latent ruthenium Schiff base olefin metathesis catalyst: Catalyst activation and mechanistic studies
Authors: Monsaert Stijn , Ledoux Nele , Drozdzak Renata , Verpoort Francis
Published: December 2009

A ruthenium Schiff base catalyst (5), bearing an N‐heterocyclic carbene ligand, was found to be a latent catalyst for the ring‐opening metathesis polymerization of cis,cis‐1,5‐cyclooctadiene and dicyclopentadiene and is activated efficiently on addition of hydrochloric acid. A benchmark study was performed using the Grubbs first (1), second (2), and third (3) generation catalyst. Results further illustrate that the catalyst can be stored in dicyclopentadiene at a monomer/catalyst ratio of 15,000/1 without any significant polymerization during at least 12 months. After activation of the catalyst with a Brønsted acid, no undesired loss of performance can be detected. This concept of activation can be easily adapted to a Reaction Injection Molding process, and reaction control is obtained via the in situ generation of the cocatalyst as the outcome of the reaction of alcohols with Lewis acids. Insight into the activation mechanism was gained through an in‐depth nuclear magnetic resonance study, and a plausible mechanism is proposed. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 302–310, 2010
Facile one‐step synthesis of electromagnetic functionalized polypyrrole/Fe3O4 nanotubes via a self‐assembly process
Authors: Zhang Wei‐Dong , Xiao Hong‐Mei , Zhu Lu‐Ping , Fu Shao‐Yun , Wan Mei‐Xiang
Published: December 2009

This article reports a simple self‐assembly process for facile one‐step synthesis of novel electromagnetic functionalized polypyrrole (PPy)/Fe3O4 composite nanotubes using p‐toluenesulfonic acid (p‐TSA) as the dopant and FeCl3 as the oxidant. The key trick of the present method is to use FeCl3 as the oxidant for both PPy and Fe3O4 in the same time to synthesize PPy/Fe3O4 composite nanotubes in one‐step. This facile one‐step method is much simpler than the conventional approach using the Fe3O4 nanoparticles as the additives. Compared to the similar composites synthesized using the conventional method, the as‐prepared PPy‐p‐TSA/Fe3O4 composite nanotubes using the facile one‐step self‐assembly process show much higher room‐temperature conductivity. Moreover, the composite nanotubes display interesting ferromagnetic behavior. The electrical properties of the PPy‐p‐TSA/Fe3O4 composite nanotubes are dominated by the amount of FeCl3 while their magnetic properties are controlled by the amount of FeCl2. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 320–326, 2010
Effect of solvent on the dehydrogenation of poly(1,3‐cyclohexadiene): Formation and characteristics of benzoquinone–aromatic hydrocarbon charge‐transfer complexes
Authors: Natori Itaru , Natori Shizue , Sekikawa Hiroyuki , Ogino Kenji
Published: December 2009

The effect of solvent on the dehydrogenation of poly(1,3‐cyclohexadiene) (PCHD) with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) [or 2,3,5,6‐tetrachloro‐1,4‐(p‐)‐benzoquinone (TCQ)] was examined to improve the reactivity of benzoquinones for this dehydrogenation reaction. The dehydrogenation of PCHD with DDQ (or TCQ) was strongly affected by the type of solvent, and aromatic hydrocarbon based solvents were appropriate for this dehydrogenation reaction. A charge‐transfer complex between DDQ (or TCQ) and aromatic hydrocarbons was formed in the reaction mixture, and the reactivity of the complex was much higher than that of free DDQ (or TCQ). The formation of a DDQ–aromatic hydrocarbon complex, which has a large diamagnetic shift of the 13C NMR signals with respect to DDQ, was the primary factor for improvement of the reactivity of DDQ. For the TCQ–aromatic hydrocarbon complex, the existence of an electron‐withdrawing group on the aromatic hydrocarbon was the major factor for improvement of the reactivity of TCQ. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 342–350, 2010
Investigation of spacer influences in phosphorescent‐emitting nonconjugated PLED systems
Authors: Thesen Manuel W. , Krueger Hartmut , Janietz Silvia , Wedel Armin , Graf Marion
Published: December 2009

An assay was introduced to clarify influences on electroluminescent behavior for RGB‐colored phosphorescent terpolymers with N,N‐Di‐p‐tolyl‐aniline as hole‐transporting unit, 2‐(4‐biphenyl)‐5‐(4‐tert‐butylphenyl)‐1,3,4‐oxadiazole (tert‐BuPBD) as electron‐transporting unit, and different iridium complexes in RGB‐colors as triplet emitting materials. All monomers were attached with spacer moieties to the “para” position of a polystyrene. Polymer light emitting diodes (PLEDs) were built to study the electro‐optical behavior of these materials. The gist was a remarkable influence of hexyl‐spacer units to the PLED performance. For all three colors only very restricted PLED performances were found. In comparison RGB‐terpolymers were synthesized with directly attached charge transport materials to the polymer backbone. For this directly linked systems efficiencies were 28 cd A−1 @ 6 V (green), 4.9 cd A−1 @ 5 V (red) and 4.3 cd A−1 @ 6 V (bluish). In summary we assume that an improved charge percolation pathways regarding to the higher content of semiconducting molecules and an improved charge transfer to the phosphorescent dopand in the case of the copolymers without spacers are responsible for the better device performance comparing the copolymers with hexyl spacers. The approach of the directly connected charge transport materials at the nonconjugated styrene polymer backbone should be favored for further investigations, therefore. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 389–402, 2010
Synthesis, one‐ and two‐photon properties of poly[9,10‐bis(3,4‐bis(2‐ethylhexyl‐oxy)phenyl)‐2,6‐anthracenevinylene‐alt‐N‐octyl‐3,6‐/2,7‐carbazolevinylene]
Authors: Zhang Haichang , Guo Erqian , Zhang Xueheng , Yang Wenjun
Published: December 2009

The synthesis, one‐ and two‐photon absorption (TPA) and emission properties of two novel 2,6‐anthracenevinylene‐based copolymers, poly[9,10‐bis(3,4‐bis(2‐ethylhexyloxy)phenyl)‐2,6‐anthracenevinylene‐alt‐N‐octyl‐3,6‐carbazolevinyl‐ene] (P1) and poly[9,10‐bis(3,4‐bis(2‐ethylhexyloxy)phenyl)‐2,6‐anthracenevinyl‐ene‐alt‐N‐octyl‐2,7‐carbazolevinylene] (P2) were reported. The as‐synthesized polymers have the number‐average molecular weights of 1.56 × 104 for P1 and 1.85 × 104 g mol−1 for P2 and are readily soluble in common organic solvents. They emit strong bluish‐green one‐ and two‐photon excitation fluorescence in dilute toluene solution (ϕP1 = 0.85, ϕP2 = 0.78, λem(P1) = 491 nm, λem(P2) = 483 nm). The maximal TPA cross‐sections of P1 and P2 measured by the two‐photon‐induced fluorescence method using femtosecond laser pulses in toluene are 840 and 490 GM per repeating unit, respectively, which are obviously larger than that (210 GM) of poly[9,10‐bis‐(3,4‐bis(2‐ethylhexyloxy) phenyl)‐2,6‐anthracenevinylene], indicating that the poly(2,6‐anthracenevinylene) derivatives with large TPA cross‐sections can be obtained by inserting electron‐donating moieties into the polymer backbone. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 463–470, 2010
Highly efficient catalysts‐acetylacetonato complexes of transition metals in the 4th period for ring‐opening polymerization of 1,3‐benzoxazine
Authors: Sudo Atsushi , Hirayama Shoji , Endo Takeshi
Published: December 2009

Acetylacetonato (acac) complexes of transition metals in the 4th period were examined as catalysts for the ring‐opening polymerization of benzoxazine. This examination revealed that acac complexes of manganese, iron, and cobalt exhibited the highest activity, which was comparable or slightly higher than that exhibited by p‐toluenesulfonic acid. By replacing acac ligand by hexafluoroacetylacetonato (F6‐acac) ligand, the activity of manganese and iron complexes was remarkably enhanced. These metal F6‐acac complexes were tolerant to moisture to allow their use under air without special caution. Another advantage was their negligible effect to promote unfavorable weight loss during the polymerization. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 479–484, 2010
Crystalline microstructure and mechanical properties of crosslinked EPDM aged under gamma irradiation
Authors: Planes Emilie , Chazeau Laurent , Vigier Gérard , Chenal Jean‐Marc , Stuhldreier Thomas
Published: December 2009

The morphology and the mechanical properties at room temperature of crosslinked EPDM irradiated or not have been studied. It has been shown that these materials are composed of two phases: semicrystalline zones with a crystallinity ratio of 20% and mainly amorphous zones. The semicrystalline zones make a continuous path through the film and therefore control the mechanical properties of the material below the melting temperature. As irradiation (in the tested range of irradiation dose) and crosslinking degree have no significant influence on the arrangement and proportion of the crystalline lamellae, all samples have nearly the same mechanical behavior at small strains. At large strains, the interactions between amorphous and crystalline parts in semicrystalline zones play the main role in the mechanical response; irradiation, by degradation of these interactions, leads to a smaller hardening phenomenon and a decrease in elongation at break. From an application point of view, in spite of the low crystallinity fraction of these materials, the presence of an important number of crystallites, as evidenced by SAXS measurements, strongly limits the consequences of irradiation on the mechanical properties. However, the mechanical reinforcement strongly depending on the presence of these crystallites, it is therefore highly sensitive to temperature: this can be an important issue for the applications of these materials since their use temperature is close to the crystallite melting temperature. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 97–105, 2010
Porous Photoresist Stamps for Selective Plasma Treatment
Authors: Stöhr Uwe , Dohse Antje , Hoppe Paul , Gehringer Andreas , Thomas Michael , Klages Claus‐Peter , Reinecke Holger
Published: December 2009

A porous plasma stamp has been developed allowing selective plasma treatment and coating of flat surfaces by using a dielectric barrier discharge arrangement at atmospheric pressure. The stamp consists of a porous sinter metal plate covered with photoresist. The photoresist is structured to form cavities in which the plasma is burning. The cavity footprint is the desired structure to be reproduced or “plasma printed” on the substrate. It is shown that flat substrate surfaces can be treated in the same scale as the cavity dimensions and that the treated areas are defined by the footprint of the cavities with a precision in micrometer scale. This work describes in detail the manufacturing process of the plasma stamp and furthermore shows that the stamp can be used to plasma‐coat surfaces selectively because the stamp cavities can continuously be filled with process gases through the porous metal plate. Applying process gas containing polymerizable monomers to a porous material will close the pores after a certain plasma treatment time. As a consequence this work also addresses the issue of cleaning the stamp to keep it intact for a long term usage.

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Growth and luminescent properties of TbAlO3: Mn single‐crystalline films
Authors: Zorenko Yu. , Gorbenko V. , Vozniak T. , Batentschuk M. , Osvet A. , Winnacker A.
Published: December 2009

The paper is dedicated to the investigation of growth processes by liquid phase epitaxy (LPE) and the luminescent properties of single‐crystalline films (SCFs) of TbAlO3 terbium‐aluminum perovskite (TbAP) perovskite doped with manganese ions. We found that the Mn2+ and Mn3+ or even Mn5+ states can occur in TbAP:Mn SCF depending on the concentration of manganese ions in the 0.01–1.1 at.% range. The Mn2+ ions in TbAP host possess orange luminescence in the band peaked at 572 nm with a lifetime of 1.24 ms at 300 K that is caused by the 4T1 →6 A1 radiative transitions. The cascade energy‐transfer processes can be realized in TbAP:Mn SCF: (i) from 5d–4f states of Tb3+ cations to Mn2+ ions; (ii) from Mn2+ ions to 4f states of Tb3+ cations. The latest process strongly decreases the efficiency of Mn2+ luminescence in TbAlO3 perovskite with respect to the Tb3Al5O12 garnet host.
Phase structure and electrical properties of 0.8Pb(Mg1/3Nb2/3)O3–0.2PbTiO3 relaxor ferroelectric ceramics prepared by the reaction‐sintering method
Authors: Ding Chenlu , Fang Bijun , Du Qingbo , Zhou Limin
Published: December 2009

Phase pure perovskite 0.8Pb(Mg1/3Nb2/3)O3–0.2PbTiO3 (0.8PMN–0.2PT) ferroelectric (FE) ceramics were prepared by the reaction‐sintering method at a sintering temperature range of 1200–1250 °C. The sintered ceramics exhibit large relative density, where the 0.8PMN–0.2PT ceramics sintered at 1250 °C possess the largest value of relative density, reaching 99.56% of the theoretical density. All the sintered 0.8PMN–0.2PT ceramics exhibit broad, diffused, and frequency‐dependent dielectric response peaks at around 80 °C and saturated and symmetric P–E hysteresis loops. The 0.8PMN–0.2PT ceramics exhibit excellent electrical properties, where the value of dielectric constant maximum εm is 35 750 at 1 kHz, the remanent polarization Pr is 33.01 µC/cm2, the coercive field Ec is 2.79 kV/cm, and the piezoelectric constant d33 is 259 pC/N.
New MBE growth method for high quality InN and related alloys using in situ monitoring technology
Authors: Yamaguchi Tomohiro , Nanishi Yasushi
Published: December 2009

A new radio‐frequency plasma‐assisted molecular beam epitaxy (RF‐MBE) method, named droplet elimination by radical beam irradiation (DERI), is utilized for the growth of InN. This method is composed of two series of growth processes: (1) InN growth under an In‐rich condition and (2) consecutive nitrogen radical beam irradiation. This method is simple, enabling the reproducible growth of a high‐quality thick InN film with a flat surface. This method is also effective for monitoring a nitrogen radical beam that is responsible for InN growth. This new growth method is also applied to InGaN growth. The results indicate a preferable Ga capturing process on an InGaN growing surface, particularly when the samples are grown under a metal‐rich condition.
Whispering gallery mode in periodic InGaN‐based hexagonal nanoring arrays grown by rf‐MBE using Ti‐mask selective‐area growth
Authors: Kouno Tetsuya , Kishino Katsumi , Kikuchi Akihiko
Published: December 2009

We fabricated periodic InGaN‐based hexagonal nanoring arrays by rf‐molecular beam epitaxy (rf‐MBE) with Ti‐mask selective‐area growth (SAG). Multiple photoluminescence peaks from InGaN‐based hexagonal nanorings were observed in room temperature photoluminescence (RT‐PL) measurements with a 325 nm He–Cd laser. We employed a simple plane wave model and a two‐dimensional finite difference time domain (2D‐FDTD) method in the numerical analysis to investigate these multiple peaks. Experimental data was in good coincidence with calculated data, evincing that whispering gallery modes (WGMs) supported in the InGaN‐based hexagonal nanorings were responsible for the multipeaks.
MOVPE growth and characterization of indium nitride on C‐, A‐, M‐, and R‐plane sapphire
Authors: Moret Matthieu , Ruffenach Sandra , Briot Olivier , Gil Bernard
Published: December 2009

We have investigated the heteroepitaxial growth of indium nitride on sapphire substrates having different orientations. Growths were performed on C‐, A‐, M‐, and R‐plane‐oriented sapphire in order to analyze the substrate orientation effect on the structural, optical, and electronic properties of InN. The orientation relationship between InN and sapphire was deduced by θ/2θ High‐resolution X‐ray diffraction (HRXRD) measurements. These experiments show the ability to grow InN along nonpolar (1120) orientation and the semipolar (1122) orientation, depending of the orientations of the sapphire substrate. The crystalline quality was assessed by XRD symmetric and asymmetric rocking curve measurements. We observed no drastic disparity between our samples, all exhibiting a reasonable crystalline quality. Atomic force microscopy imaging on these layers revealed different surface morphologies with a roughness varying between 30 and 60 nm. Electrical properties of the InN samples were investigated by room temperature Hall effect measurements and a line shape fitting of the photoluminescence was performed in order to get optically the values of the residual carrier density in the nitride layers.
A modelling case‐study of soil moisture–atmosphere coupling
Authors: Gaertner M. A. , Domínguez M. , Garvert M.
Published: December 2009

A sensitivity analysis of a moist convection case‐study of the 2005 West African monsoon has been performed with the limited‐area model PROMES. In the control simulation, soil moisture was initialized based on European Centre for Medium‐Range Weather Forecasts (ECMWF) soil moisture. A relatively wet patch appears over an area that was affected later by the passage of a squall line. The control simulation is able to reproduce a squall line that crosses over this wet surface, which makes it possible to analyse the sensitivity of the modelled convective system to a soil moisture increase up to saturation in the cited patch. The wetter land surface in the sensitivity run generates a cooler and moister area in the near‐surface atmospheric fields compared to the control run, and the surface wind differences between both runs show a divergent pattern. The humidity and temperature differences follow the diurnal cycle of the monsoon flow, as the cool and moist atmospheric perturbation remains over the wet patch during the afternoon, and moves towards the northeast during the night. There is a clear interaction between the soil moisture perturbation and an approximating African Easterly Wave. This interaction generates larger differences between the two runs on the second simulation day than on the first. The precipitation is reduced over the wet patch in the sensitivity run, but over a larger area a precipitation increase is obtained, reflecting a complex soil moisture‐precipitation feedback. Copyright © 2009 Royal Meteorological Society
The effect of iron phosphate, alumina and silica coatings on the morphology of carbonyl iron particles
Authors: Bruncková H. , Kabátová M. , Dudrová E.
Published: December 2009

Carbonyl iron powders were coated with iron phosphate using phosphating method and boehmite (γ‐AlOOH) or silicon hydroxide (Si(OH)4) nanoparticles derived from the hydrolysis of tri‐sec‐butoxide (Al(OC4H9)3) or tetramethylsilane (Si(OCH3)4) using sol–gel method. The coated powders were dried and calcined at 400 °C for 3 h in air. Cross‐section morphology of coated carbonyl iron powders were investigated by scanning electron microscopy energy dispersive X‐ray analysis. Coated Fe micro‐particles were spherical in shape with ‘shell/core’ structures. The shells consisted of an amorphous layer with varying thickness (100–800 nm) and the core represented a carbonyl iron.

Gelatinous morphology of dried FePO4 coating composed from nanoparticles of iron oxyhydroxides and hydrated iron phosphate with a shell thickness of ∼100 nm around iron particles was observed. In coatings based on alumina or silica xerogels with a thickness of ∼100–150 nm or ∼200–500 nm, the coatings were composed of iron oxyhydroxides and γ‐AlOOH or Si(OH)4. The resulting XRD diffractograms revealed the hematite (α‐Fe2O3) and magnetite (Fe3O4) that were formed in phosphated and sol–gel coated iron powders. The X‐ray diffraction patterns did not verify the presence of phosphates, alumina or silica and indicate the amorphous or nanocrystalline structure of FePO4, γ‐Al2O3 and SiO2. Copyright © 2009 John Wiley & Sons, Ltd.