bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding geomorphic responses to environmental change: a 19 000‐year case study from semi‐arid central Texas, USA
Authors: Boulter Claire , Bateman Mark D. , Frederick Charles D.
Published: January 2010

Understanding the impact of past climatic changes on landscape stability is crucial in order to predict and mitigate the effects of future changes. However, in arid and semi‐arid environments, reconstructions are often hampered by a poor understanding of the relationship between sediment deposition and climate. We present here data from central Texas, a region that is sensitive to environmental change but has received relatively little attention. The study integrates a chronology of 29 optically stimulated luminescence (OSL) ages from six sedimentary sites in a range of depositional contexts with a 19 000 a climate record derived from pollen extracted from the adjacent Boriack Bog. By comparing the two records, we aimed to assess the relationship between climate change and geomorphic activity. Data show that extensive aeolian and colluvial deposition occurred during the mid to late Holocene, with sedimentation generally increasing during more arid phases. However, a number of depositional events on slopes were associated with moister episodes, and sediment was also deposited in a summit setting immediately after phases of increased precipitation. Linkages between climate change and geomorphic response were therefore complex, being controlled by both sediment supply and transport energy. The climatic fluctuations identified in the Boriack Bog record highlight the sensitivity of central Texas to environmental change, while disparities in conditions recorded between it and other palaeoenvironmental sites in the southern USA emphasise the need for further work in order to enhance understanding of landscape sedimentary response to climate. Copyright © 2010 John Wiley & Sons, Ltd.
1‐Methylcyclopropene affects the antioxidant system of apricots (Prunus armeniaca L. cv. Búlida) during storage at low temperature
Authors: Egea Isabel , Flores Francisco B , Martínez‐Madrid Maria C , Romojaro Felix , Sánchez‐Bel Paloma
Published: January 2010

BACKGROUND: Apricots (Prunus armeniaca cv. Búlida) were treated with 1 mL L−1 1‐methylcyclopropene (1‐MCP) immediately after harvest and stored in air at 2 °C for 21 days. Antioxidant levels (ascorbic acid and carotenoids), enzymatic antioxidant activities (superoxide dismutase (SOD) and unspecific peroxidase (POX)) and total antioxidant capacity (trolox equivalent antioxidant capacity (TEAC)) were determined. The level of oxidative stress was also established by measuring ion leakage during storage. The changes in the antioxidant potential of apricots were related to the capacity of 1‐MCP to increase their commercial life.

RESULTS: 1‐MCP‐treated fruits exhibited higher SOD activity, whereas POX activity was significantly higher only after 21 days at 2 °C. Treated fruits also exhibited better retention of ascorbate and carotenoids and higher TEAC during storage. In accordance with these observations, lower ion leakage values were detected in 1‐MCP‐treated apricots.

CONCLUSION: Taken together, these results suggest that 1‐MCP conferred a greater resistance to oxidative stress. This, along with the reduction in ethylene production, could contribute to the increase in commercial life and nutritional value observed in 1‐MCP‐treated apricots. Copyright © 2010 Society of Chemical Industry
The effect of gaseous ozone treatment on egg components
Authors: Fuhrmann Herbert , Rupp Nadine , Büchner Andrea , Braun Peggy
Published: January 2010

BACKGROUND: Because of the salmonella problem in poultry, disinfection technologies are necessary. Ozone is a strong oxidant used for the disinfection of surfaces, drinking water and foods. However, since ozone not only destroys bacteria but may also damage eggs, it is necessary to clarify the effects of ozone treatment on hatching egg components. In this study, doses of gaseous ozone ranging from 10 to 50 mL L−1 were tested. The vitamin A and E contents and fatty acid composition of the egg yolk were determined. To detect possible damage to the DNA of the germ disc, single‐cell gel electrophoresis was used. Moreover, free SH groups were measured in the egg white. The soluble cuticula proteins were analysed by polyacrylamide gel electrophoresis.

RESULTS: The yolk was not significantly affected by ozone treatment. However, the DNA of the germ disc was attacked and a significant decrease in free SH groups in the egg white was recorded at 50 mL L−1 ozone. Even at low ozone doses the soluble cuticula proteins were completely destroyed.

CONCLUSION: Significant alterations of egg components were caused by 50 mL L−1 ozone. At lower ozone doses the oxidative processes occurred mainly at the egg surface and are therefore probably harmless to the developing embryo. Copyright © 2010 Society of Chemical Industry
Comparison of different immunoprophylaxis regimens after liver transplantation with hepatitis B core antibody–positive donors: A systematic review
Authors: Saab Sammy , Waterman Benjamin , Chi Amanda C. , Tong Myron J.
Published: January 2010

Orthotopic liver transplantation (OLT) recipients without hepatitis B virus (HBV) infection who receive liver grafts from antibody to hepatitis B core antigen–positive [HBcAb(+)], hepatitis B surface antigen–negative [HBsAg(−)] donors have an increased risk of developing de novo hepatitis B infection. We compared the 2 most commonly employed prophylactic regimens—lamivudine (LAM) monotherapy and hepatitis B immunoglobulin (HBIG)+LAM combination therapy—to determine the relative efficacies of these 2 protocols in preventing de novo hepatitis B infection. A comprehensive search of the Cochrane Database of Systematic Reviews, MEDLINE (1966 to June 2009), and bibliographies of retrieved trials was conducted. Eligible studies included OLT recipients who received HBcAb(+) liver grafts and were treated prophylactically with either LAM monotherapy or HBIG+LAM combination therapy. 13 studies were identified as meeting the eligibility criteria. The rates of de novo hepatitis B infection, mortality, and mortality due to de novo hepatitis B infection were assessed. The incidence of de novo hepatitis B infection was 2.7% (n = 73) in patients receiving LAM-only prophylaxis versus 3.6% (n = 110) in patients receiving HBIG+LAM combination therapy. In the HBIG+LAM group, the dose and duration of HBIG therapy were highly variable. The median follow-up time for the LAM monotherapy group was 25.4 months with a range of 14.78 to 27.6 months, whereas the median follow-up time for the LAM+HBIG group was 31.1 months with a range of 15.3 to 38.5 months. The risk of developing de novo hepatitis B infection based on the pretransplant recipient HBV serology in each treatment group could not be calculated because of incomplete data and the limited number of de novo hepatitis B infection cases in the series reviewed. In conclusion, on the basis of these findings, we conclude that published studies have not shown HBIG+LAM combination therapy to be more effective than LAM-only treatment. Nucleoside analogue monotherapy should therefore be considered when one is treating HBV(−) patients who have received liver allografts from HBcAb(+) donors. Liver Transpl 16:300–307, 2010. © 2010 AASLD.
Cultural adaptation and translation of measures: An integrated method
Authors: Sidani Souraya , Guruge Sepali , Miranda Joyal , Ford‐Gilboe Marilyn , Varcoe Colleen
Published: January 2010

Differences in the conceptualization and operationalization of health‐related concepts may exist across cultures. Such differences underscore the importance of examining conceptual equivalence when adapting and translating instruments. In this article, we describe an integrated method for exploring conceptual equivalence within the process of adapting and translating measures. The integrated method involves five phases including selection of instruments for cultural adaptation and translation; assessment of conceptual equivalence, leading to the generation of a set of items deemed to be culturally and linguistically appropriate to assess the concept of interest in the target community; forward translation; back translation (optional); and pre‐testing of the set of items. Strengths and limitations of the proposed integrated method are discussed. © 2010 Wiley Periodicals, Inc. Res Nurs Health 33:133–143, 2010
Effect of elongational flow on morphology and properties of polymer/CNTs nanocomposite fibers
Authors: Dintcheva N. Tz. , Arrigo R. , Morreale M. , La Mantia F. P. , Matassa R. , Caponetti E.
Published: January 2010

Carbon nanotubes (CNTs) have been attracting increasing interest for the fabrication of polymer‐based nanocomposites because of their excellent properties. Traditional methods for the preparation of polymer/CNTs nanocomposites are in situ polymerization, solution blending, and melt mixing. The achievement of a good CNT dispersion and a percolation network is important in order to obtain better mechanical and electrical properties. However, the rheological behavior of polymer/CNTs systems, in particular regarding the extensional flow, has not been much investigated so far. In this work we present, for the first time, rheological data in non‐isothermal extensional flow and an investigation on the effect of the extensional flow upon the final properties of several polymer/CNTs systems was carried out as well. Extensional flow led to higher mechanical properties and higher melt strength, but only a slightly reduced breaking stretching ratio. This result could be particularly interesting in the view of potential industrial applications such as film blowing and spinning. Morphological analyses also showed higher degrees of dispersion and variation in the CNTs final dimensions. Copyright © 2010 John Wiley & Sons, Ltd.
Quality control of Pulsatilla koreana based on the simultaneous determination of triterpenoidal saponins by HPLC‐ELSD and principal component analysis
Authors: Lee Ki Yong , Cho Young Woong , Park Junghyun , Lee Dong Young , Kim Seung Hyun , Kim Young Choong , Sung Sang Hyun
Published: January 2010

Introduction – Pulsatilla koreana Nakai, with triterpenoidal saponins as its main pharmacological effective compounds, is known to have several biological activities, including hypoglycaemic, antitumour, cognition‐enhancing, neuroprotective, cytotoxic and antiangiogenic activities. However, few analytical methods have been reported on the quality assessment of P. koreana roots.

Obejective – To establish a high‐performance liquid chromatography coupled with evaporative light scattering detection for the simultaneous determination of five triterpenoidal saponins, including pulsatilloside E (1), pulsatilla saponin H (2), anemoside B4 (3), hederacolchiside E (4) and cussosaponin C (5) in P. koreana.

Methodology – The chromatographic separation was performed on a Shiseido CapCell PAK C18 analytical column efficiently using gradient elution with acetonitrile and water.

Results – All calibration curves showed excellent linear regressions (R2 > 0.9996) within the range of tested concentrations. The intra‐ and inter‐day variations were below 4.78% in terms of RSD. The recoveries were 94.82–102.97% with RSD of 0.27–3.92% for spiked P. koreana samples.

Conclusion – The validated method was successfully used for the analysis of five saponins in P. koreana from different locations. Moreover, the different samples were clustered in accordance with contents of triterpenoidal saponins based on aglycon type by a principal component analysis. Copyright © 2010 John Wiley & Sons, Ltd.
Polypyrrole free‐standing electrodes sense temperature or current during reaction
Authors: Valero Laura , Arias‐Pardilla Joaquin , Smit Mascha , Cauich‐Rodríguez Juan , Otero Toribio F
Published: January 2010

The electrochemical activity of self‐supported thick (70 µm) polypyrrole films electrogenerated in a mixed electrolyte of dodecylbenzenesulfonic acid and LiClO4 was studied in aqueous solutions of LiClO4. This material inhibits hydrogen evolution up to cathodic potentials of −3.0 V versus Ag/AgCl. During oxidation or reduction reactions under galvanostatic conditions, the electrical energy consumed for a constant charge is a function of either the working temperature or the flowing current. As a consequence any electrochemical device, moreover artificial muscles, constructed with reactive conducting polymers is expected to work simultaneously as a sensor of the working temperature. Copyright © 2010 Society of Chemical Industry
Preparation and characterization of monodisperse CdS quantum dot‐polymer microspheres
Authors: Shao Qian , Yang Chengli , Jiang Lingzhi , He Jie , Li Shijie , Jiang Biwang
Published: January 2010

A novel and effective method for the preparation of monodisperse CdS quantum dot‐polymer microspheres was proposed. The monodisperse hollow polymer microspheres were firstly swelled in chloroform. Then, the reaction precursor composed of CdO and sulfur, was impregnated into the hollow polymer microspheres. Subsequently, the CdS quantum dots were synthesized directly within the polymer microspheres by thermal decomposition. The morphology, structure, and fluorescence properties of CdS quantum dot‐polymer microspheres were studied by scanning electron microscope, transmission electron microscope, fluorescence microscope, and flow cytometry. The results indicate that the fluorescent CdS quantum dots are successfully synthesized in the monodisperse hollow polymer microspeheres, which provide very strong fluorescence intensity, and offer excellent photostability due to the compact structure of the polymer matrix. These CdS quantum dot‐polymer microspheres have potential applications in biotechnology and biomedicine. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 751–755, 2010
Poly(terthiophene)s from copolymer precursors via solid‐state oxidative conversion
Authors: Kumar Arvind , Invernale Michael A. , Jang Sung‐Yeon , Sotzing Gregory A.
Published: January 2010

Herein, we report the synthesis of conducting poly (terthiophene)s using a side chain precursor polymer approach. Random copolymers were prepared by ring opening metathesis polymerization of two norbornylene monomers, one containing a pendant terthiophene group and the other containing a pendant acetate group. Solid‐state oxidative conversion of the terthiophene units was used to produce conductive polymers. Oxidative solid‐state conversion was successful for copolymers containing as little as 1 mol % of terthiophene comonomer. The electrical and optical properties of CPs were studied as a function of the amount of electroactive moiety, terthiophene (3T), present in the copolymer. The CPs were found to have conductivity varying between 10−1 and 10−4 S/cm depending on the precursor copolymer compositions. The CPs obtained from all precursors had no significant difference in their energy gaps and showed blue to orange color transitions when switching from the oxidized to the neutral states, respectively. The absorbance intensity at 426 nm for poly(3T) from the precursors fits the Beer–Lambert law corresponding to the range of initial 3T content in the precursor copolymer composition (from 1 to 100 mol %). © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 756–763, 2010
Thermoresponsive terpolymers based on methacrylate monomers: Effect of architecture and composition
Authors: Ward Mark A. , Georgiou Theoni K.
Published: January 2010

A series of amphiphilic thermoresponsive copolymers was synthesized by group transfer polymerization. Seven copolymers were prepared based on the nonionic hydrophobic n‐butyl methacrylate (BuMA), the ionizable hydrophilic and thermoresponsive 2‐(dimethylamino)ethyl methacrylate (DMAEMA) and the nonionic hydrophilic poly(ethylene glycol)methyl methacrylate (PEGMA). In particular, one diblock copolymer and six tricomponent copolymers of different architectures and compositions, one random and five triblock copolymers, were synthesized. The polymers and their precursors were characterized in terms of their molecular weight and composition using gel permeation chromatography and proton nuclear magnetic resonance spectroscopy, respectively. Aqueous solutions of the polymers were studied by turbidimetry, hydrogen ion titration, and light scattering to determine their cloud points, pKas, and hydrodynamic diameters and investigate the effect of the polymers' composition and architecture. The thermoresponsive behavior of the copolymers was also studied. By increasing the temperature, all polymer solutions became more viscous, but only one polymer, the one with the highest content of the hydrophobic BuMA, formed a stable physical gel. Interestingly, the thermoresponsive behavior of these triblock copolymers was affected not only by the terpolymers' composition but also by the terpolymers' architecture. These findings can facilitate the design and engineering of injectable copolymers for tissue engineering that could enable the in situ formation of physical gels at body temperature. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 775–783, 2010
Synthesis and properties of high‐molecular‐weight stereo di‐block polylactides with nonequivalent D/L ratios
Authors: Hirata Masayuki , Kobayashi Kaori , Kimura Yoshiharu
Published: January 2010

Di‐stereoblock polylactides (di‐sb‐PLA: PLLA‐b‐PDLA) having high molecular weight (Mn > 100 kDa) were successfully synthesized by two‐step ring‐opening polymerization (ROP) of L‐ and D‐lactides using tin(2‐ethylhexanoate) as a catalyst. By optimizing the polymerization conditions, the block sequences were well regulated at non‐equivalent feed ratios of PLLA and PDLA. This synthetic method consisted of three stages: (1) polymerization of either L‐ or D‐lactide to obtain a PLLA or PDLA prepolymer with a molecular weight less than 50 kDa, (2) purification of the obtained prepolymer to remove residual lactide, and (3) polymerization of the enantiomeric lactide in the presence of the purified prepolymer. Their 13C and 31P NMR spectra of the resultant di‐sb‐PLAs strongly supported their di‐stereo block structure. These di‐sb‐PLAs, having weight‐average molecular weights higher than 150 kDa, were fabricated into polymer films by solution casting and showed exclusive stereocomplexation. The thermomechanical analysis of the films revealed that their heat deformation temperature was limited probably because of their low crystallinity owing to the non‐equivalent PLLA/PDLA ratio. The blend systems of the di‐sb‐PLAs having complementary stereo‐sequences (the one with a long PLLA block and the other with long PDLA block) were also prepared and characterized to enhance the sc crystallinity. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 794–801, 2010
Three‐component polyaddition of diamines, carbon disulfide, and diacrylates in water
Authors: Nagai Daisuke , Imazeki Tsutomu , Morinaga Hisatoyo , Oku Hiroyuki , Kasuya Ken‐Ichi
Published: January 2010

The three‐component polyaddition of diamines, carbon disulfide (CS2), and diacrylates in water was successfully achieved without the use of a surfactant or catalyst. Appropriate reaction conditions (i.e., reaction temperature, reaction time, and CS2 feed) enabled the polyaddition of 1,3‐di‐4‐piperidylpropane (1a), CS2, and 1,6‐hexanediol diacrylate (2a) to afford the corresponding poly(dithiourethane‐amine) containing 83% of dithiourethane units in 84% yield. Polyaddition of other monomers also proceeded under the optimum conditions to afford various poly(dithiourethane‐amine)s. Unsuccessful results for polyaddition in organic solvents such as toluene, tetrahydrofuran, and N,N‐dimethylformamide revealed that the polyaddition is accelerated in water. The obtained poly(dithiourethane‐amine)s adsorbed Au (III) efficiently under acidic conditions, due to the strong interaction of the thiocarbonyl sulfur in the dithiourethane unit with Au (III). The poly(dithiourethane‐amine)s also showed selective adsorption for Au (III) from a mixture of metal ions [Au (III), Fe (III), Mn (II), and Zn (II)], which indicates their potential utilization for the collection of gold. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 845–851, 2010
Quinoline‐containing networks from enone and aldehyde triglyceride derivatives
Authors: Montero de Espinosa Lucas , Ronda Juan C. , Galià Marina , Cádiz Virginia
Published: January 2010

The crosslinking reaction of a triglyceride derivative containing α,β‐unsaturated ketones with diaminodiphenylmethane via aza‐Michael addition has been extensively studied. First, a model study with monofunctional compounds showed that the conjugated addition product undergoes a series of transformations leading to formation of a substituted quinoline. The proposed reaction pathway is presented as a variation of the Skraup‐Doebner‐Von Miller quinoline synthesis. The presence of quinolines as crosslinking points in the cured materials has been proved by means of different characterization techniques, and the properties derived from this aromatization process have been described. This new crosslinking approach has been successfully applied to an aldehyde‐containing triglyceride to obtain quinoline‐containing thermosets. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 869–878, 2010
Preparation, characterization, and electrical properties of dual‐emissive Langmuir‐Blodgett films of some europium‐substituted polyoxometalates and a platinum polyyne polymer
Authors: Liu Li , Chen Ming , Yang Jun , Liu Shi‐Zhong , Du Zu‐Liang , Wong Wai‐Yeung
Published: January 2010

A new series of organometallic/inorganic composite Langmuir‐Blodgett (LB) films consisting of a rigid‐rod polyplatinyne polymer coordinated with 2,7‐bis(buta‐1,3‐diynyl)‐9,9‐dihexylfluorene (denoted as PtP) as the π‐conjugated organometallic molecule, an europium‐substituted polyoxometalate (POM; POM = Na9EuW10O36, K13[Eu(SiW11O39)2] and K5[Eu(SiW11O39)(H2O)2]) as the inorganic component, and an amphiphilic behenic acid (BA) as the auxiliary film‐forming agent were prepared. Structural and photophysical characterization of these LB films were achieved by π–A isotherms, absorption and photoluminescence spectra, atomic force microscopy imaging, scanning tunneling microscopy, and low‐angle X‐ray diffraction. Our experimental results indicate that stable, well‐defined, and well‐organized Langmuir and LB films are formed in pure water and POM subphases, and the presence of Eu‐based POM in the subphase causes an area expansion. It is proposed that a lamellar layered structure exists for the PtP/BA/POM LB film in which the POM and PtP molecules can lay down with the interfacial planes. Luminescence spectra of the prepared hybrid LB films show that near‐white emission spectra can be obtained due to the dual‐emissive nature of the mixed PtP/POM blends. These Pt‐polyyne‐based LB films displayed interesting electric conductivity behavior. Among them, PtP/BA/POM 13‐layer films showed a good electrical response, with the tunneling current up to ±100 nA when the voltage was monitored between −1 and 7 V. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 879–888, 2010
Influence of structural features on the self‐assembly of short ionic oligopeptides
Authors: Desii Andrea , Chiellini Federica , Duce Celia , Ghezzi Lisa , Monti Susanna , Tiné Maria R. , Solaro Roberto
Published: January 2010

We investigated the self‐aggregation of 12 short ionic oligopeptides constituted by 4–7 amino acid residues to establish useful structure–property relationships that might be exploited in the biomedical field by using the concept of molecular Lego. We show that the critical aggregation concentration (CAC) of tetrapeptides decreases with increasing hydrophobicity of neutral residues. Additionally, the dependence of the CAC of isomeric oligopeptides on the distribution of amino acid residues confirms the high tendency to self‐organization of molecules with alternating ionic and neutral residues. Indeed, atomic force microscopy (AFM) images recorded on oligopeptide solutions above the CAC show the presence of either fibrillar or spherical aggregates depending on oligopeptide structure and concentration, steric hindrance, solution pH, and time. The potential of the investigated oligopeptides in tissue engineering applications is supported by their in vitro cytocompatibility. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 889–897, 2010
Chiral arylnickel complexes as highly active initiators for screw‐sense selective living polymerization of 1,2‐diisocyanobenzenes
Authors: Yamada Tetsuya , Noguchi Hiroyoshi , Nagata Yuuya , Suginome Michinori
Published: January 2010

Optically active chiral organonickel complexes served as efficient chiral initiators for living aromatizing polymerization of 1,2‐diisocyanobenzene derivatives, which afford optically active helical poly(quinoxaline‐2,3‐diyl)s up to 84% s.e. (screw‐sense excess). In comparison with asymmetric polymerization with the corresponding organopalladium initiators, the nickel initiators show a much greater polymerization rate, while the selectivity remains high. The organonickel initiators can be generated in situ from nickel(0) precursors with the corresponding enantiopure (S,S)‐2‐(4,5‐diphenylimidazolin‐2‐yl)phenyl chloride, leading to the convenient synthesis of highly stereo‐controlled poly(quinoxaline‐2,3‐diyl)s. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 898–904, 2010
Enhanced mobility and increased gas sorption capacity in thin film and nanoconduit confined polymers
Authors: Killgore Jason P. , Kocherlakota Lakshmi S. , Overney René M.
Published: January 2010

Poly(tert butyl acrylate) (PTBA) is found to exhibit enhanced mobility when spun cast into thin films or impregnated into cylindrical anodic aluminum oxide (AAO) nanoscale pores. In a thin film configuration, the glass transition temperature of 20 nm thick PTBA is found to decrease almost 20 °C compared to the bulk. Consistent with this mobility increase, an increased volume fraction of interphase polymer leads to at least a 2.4 times viscosity reduction when PTBA is impregnated in 100 nm pores versus 200 nm pores. Such increases in mobility result in a 15‐fold increase in CO2 permeability for an AAO confined geometry compared to a bulk film. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 434–441, 2010
Effect of molecular weight and substrate on silicone segregation from UV resin at plasma polymerized mold interface
Authors: Zhou Wen Xiu , Yan Ye Hai , Pan Xiaoyong , Xu Rong , Chan‐Park Mary B.
Published: January 2010

Pristine‐, poly(octafluorotoluene)‐ (POFT), and polyacetylene (PAc)‐coated Si wafers were used as substrates for the study of segregation of silicone diacrylate (SA) from a formulation containing other oligomeric and monomeric acrylates. POFT and PAc were microwave plasma polymerized on the Si wafers. Three SAs with molecular weights ranging from 700 to 6000 Da were synthesized and characterized. Formulations with 2 wt % SA were ultraviolet cured on the silicon wafers. The surface composition of formulation‐substrate side of the cured film was analyzed with X‐ray photoelectron spectroscopy, and the depth profile was analyzed with time of flight‐secondary ion mass spectrometry. The analysis results indicated that SA aggregated on all three types of Si surfaces. However, SA segregation is highest on the low surface energy POFT‐coated Si substrate, and low‐molecular‐weight SA is favorable to the segregation. For high‐molecular‐weight SA, the different Si substrates do not affect the degree of aggregation at the formulation‐substrate interface. The observed SA aggregation trend can be predicted by the Gibbs‐adsorption equation correlated to the resin surface tension and contact angle on substrates. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 442–450, 2010
Enhanced dielectric response in P(VDF‐TrFE) based all‐organic nanocomposites
Authors: Wang Jingwen , Wang YE , Li Shuqin , Xiao Jun
Published: January 2010

A nanocomposite with enhanced dielectric response is developed using poly(vinylidene fluoride‐trifluoroethylene) [P(VDF‐TrFE)] as matrix and Chemically modified high dielectric constant organic semiconductor—copper phthalocyanine oligomer (CuPc)—as filler. Transmission electron microscope (TEM)‐observed morphologies reveal that in the nanocomposite the average size of CuPc particles is about 25 nm [1/24 of that of CuPc in physical blend of P(VDF‐TrFE) and CuPc]. The hot‐press nanocomposite film with 15 wt % CuPc can realize a dielectric constant of 540 at 100 Hz. The enhanced dielectric response in the nanocomposite demonstrates the significance of the interface effect in raising the material responses far beyond that expected by simple mixing rules when there is a large dielectric contrast between the polymer matrix and the dielectric filler in the composite. It is also interesting to note that at high frequencies (such as 100 MHz) the nanocomposite has a dielectric constant of ∼100 and this value is comparable to those of current materials used in microwave applications. At 105 °C that is near the ferroelectric‐to‐paraelectric phase transition temperature of the P(VDF‐TrFE) ferroelectric, a much higher dielectric constant (about 1200 at 100 Hz) is obtained. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 490–495, 2010
One‐Step Plasma Deposition of Platinum Containing Nanocomposite Coatings
Authors: Dilonardo Elena , Milella Antonella , Palumbo Fabio , Capitani Giancarlo , d'Agostino Riccardo , Fracassi Francesco
Published: January 2010

In this paper a single step process for the synthesis of composite thin films made of platinum nanoclusters embedded in a porous hydrocarbon matrix is proposed. The process consists of a simultaneous plasma enhanced‐chemical vapour deposition of ethylene and sputtering of a platinum target. Films were characterized by means of Fourier transform‐infrared spectroscopy, X‐ray photoelectron spectroscopy, atomic force microscopy, scanning electron microscopy and transmission electron microscopy. Optical emission spectroscopy was used to investigate the plasma phase and to find correlations with the metal content of the film. The effect of radio frequency power, deposition time, and ethylene flow rate on the chemical composition and structure of the film is presented. Results show that the platinum content in the film can be controlled by tuning the power delivered to the plasma and the monomer flow rate, and that the metal aggregates in crystalline nanoclusters uniformly distributed in the material. Film morphology is characterized by columnar structures of variable diameter and orientation depending on the deposition conditions.

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Measurement of pesticide residues in peppers by near‐infrared reflectance spectroscopy
Authors: Sánchez María‐Teresa , Flores‐Rojas Katherine , Guerrero José Emilio , Garrido‐Varo Ana , Pérez‐Marín Dolores
Published: January 2010

BACKGROUND: Peppers are a frequent object of food safety alerts in various member states of the European Union owing to the presence in some batches of unauthorised pesticide residues. This study assessed the viability of near‐infrared reflectance spectroscopy (NIRS) for the measurement of pesticide residues in peppers. Commercially available spectrophotometers using different sample‐presentation methods were evaluated for this purpose: a diode‐array spectrometer for intact raw peppers and two scanning monochromators fitted with different sample‐presentation accessories (transport and spinning modules) for crushed peppers and for dry extract system for infrared analysis (DESIR), respectively.

RESULTS: Models developed using partial least squares–discriminant analysis (PLS2‐DA) correctly classified between 62 and 68% of samples by presence/absence of pesticides, depending on the instrument used. At model validation, the highest percentage of correctly classified samples—75 and 82% for pesticide‐free and pesticide‐containing samples respectively—were obtained for intact peppers using the diode‐array spectrometer.

CONCLUSION: The results obtained confirmed that NIRS technology may be used to provide swift, non‐destructive preliminary screening for pesticide residues; suspect samples may then be analysed by other confirmatory analytical methods. Copyright © 2010 Society of Chemical Industry
Hepatitis C virus nonstructural protein 4B: a journey into unexplored territory
Authors: Gouttenoire Jérôme , Penin François , Moradpour Darius
Published: January 2010

Hepatitis C virus (HCV) is a positive‐strand RNA virus that replicates its genome in a membrane‐associated replication complex. Nonstructural protein 4B (NS4B) induces the specific membrane alteration, designated as membranous web (MW), that harbours this complex. HCV NS4B is an integral membrane protein predicted to comprise four transmembrane segments in its central part. The N‐terminal part comprises two amphipathic α‐helices of which the second has the potential to traverse the membrane bilayer, likely upon oligomerisation. The C‐terminal part comprises a predicted highly conserved α‐helix, a membrane‐associated amphipathic α‐helix and two reported palmitoylation sites. NS4B interacts with other viral nonstructural proteins and has been reported to bind viral RNA. In addition, it was found to harbour an NTPase activity. Finally, NS4B has recently been found to have a role in viral assembly. Much work needs to be done with respect to further dissecting these multiple functions as well as providing a refined membrane topology and complete structure of NS4B. Progress in this direction should yield important insights into the functional architecture of the HCV replication complex and may reveal new opportunities for antiviral intervention against a leading cause of chronic hepatitis, liver cirrhosis and hepatocellular carcinoma worldwide. Copyright © 2010 John Wiley & Sons, Ltd.
Nanoscale positioning of inorganic nanoparticles using biological ferritin arrays fabricated by dip‐pen nanolithography
Authors: Bellido Elena , de Miguel Rocío , Sesé Javier , Ruiz‐Molina Daniel , Lostao Anabel , Maspoch Daniel
Published: January 2010

In this manuscript we demonstrate the spatially controlled immobilization of ferritin proteins by directly writing them on a wide range of substrates of technological interest. Optical and fluorescence microscopy, AFM and TOF‐SIMS studies confirm the successful deposition of the protein on those surfaces. Control on nanostructure shape and size, by miniaturizing the dot‐like features down to a 100 nm, demonstrates the particular capabilities of the DPN approach. Ultimately, this study gives the opportunity to design nanoparticle‐based arrays regarding the growing interest in the use of nanoparticles as structural and functional elements for fabricating nanodevices. Herein, we demonstrate how the protein shell of ferritins can be removed by a simple heat‐treatment process while maintaining the encapsulated inorganic nanoparticle intact on the same location of the nanoarray. As a result, this study establishes how direct‐write DPN approach could give the opportunity to design not only protein‐based nanoarrays but also nanoparticle‐based nanoarrays with high‐resolution and control. SCANNING 32: 35–41, 2010. © 2010 Wiley Periodicals, Inc.
Inverse model of fiber probe aperture size using a non‐destructive method
Authors: Lin Zone‐Ching , Yang Ching‐Been
Published: January 2010

This study establishes a set of theoretical line segment fabrication models of near‐field photolithography using radiation field theory—Dill's exposure model and Mack's development model. By combining the theoretical line segment fabrication model and experiments, this work constructs a novel theory of inverse calculation of fiber probe aperture size using the non‐destructive method. The experimental and simulation results obtained using the theoretical line segment fabrication model are compared; the error between these results is utilized as an objective function. The Levenberg–Marquardt method is used to search and rationalize the convergence criterion. Fiber probe aperture size that fits the experimental and theoretical model is inverse calculated. According to the results, the probe aperture obtained by this inverse model is d=250.6 nm, while the average size certified by SEM is davg=253.4 nm, the close match indicated that the probe aperture calculated with the inverse model is reasonable and can be accepted. The lithographic fabrication profile can be predicted with the inverse model to get the probe aperture and, then, cooperated with the theoretical simulated values and experimental parameter control. Such a fabrication has an application value for industry. This non‐destructive fiber probe aperture measured model can overcome the bottleneck at present to get this value by destructive measurement, thus, it has surmounted contribution in fiber probe aperture measuring techniques. SCANNING 31: 211–220, 2009. © 2010 Wiley Periodicals, Inc.
A semiparametric probit model for case 2 interval‐censored failure time data
Authors: Lin Xiaoyan , Wang Lianming
Published: January 2010

Interval‐censored data occur naturally in many fields and the main feature is that the failure time of interest is not observed exactly, but is known to fall within some interval. In this paper, we propose a semiparametric probit model for analyzing case 2 interval‐censored data as an alternative to the existing semiparametric models in the literature. Specifically, we propose to approximate the unknown nonparametric nondecreasing function in the probit model with a linear combination of monotone splines, leading to only a finite number of parameters to estimate. Both the maximum likelihood and the Bayesian estimation methods are proposed. For each method, regression parameters and the baseline survival function are estimated jointly. The proposed methods make no assumptions about the observation process and can be applicable to any interval‐censored data with easy implementation. The methods are evaluated by simulation studies and are illustrated by two real‐life interval‐censored data applications. Copyright © 2010 John Wiley & Sons, Ltd.
A polytomous conditional likelihood approach for combining matched and unmatched case–control studies
Authors: Gebregziabher Mulugeta , Guimaraes Paulo , Cozen Wendy , Conti David V.
Published: January 2010

In genetic association studies it is becoming increasingly imperative to have large sample sizes to identify and replicate genetic effects. To achieve these sample sizes, many research initiatives are encouraging the collaboration and combination of several existing matched and unmatched case–control studies. Thus, it is becoming more common to compare multiple sets of controls with the same case group or multiple case groups to validate or confirm a positive or negative finding. Usually, a naive approach of fitting separate models for each case–control comparison is used to make inference about disease–exposure association. But, this approach does not make use of all the observed data and hence could lead to inconsistent results. The problem is compounded when a common case group is used in each case–control comparison. An alternative to fitting separate models is to use a polytomous logistic model but, this model does not combine matched and unmatched case–control data. Thus, we propose a polytomous logistic regression approach based on a latent group indicator and a conditional likelihood to do a combined analysis of matched and unmatched case–control data. We use simulation studies to evaluate the performance of the proposed method and a case–control study of multiple myeloma and Inter‐Leukin‐6 as an example. Our results indicate that the proposed method leads to a more efficient homogeneity test and a pooled estimate with smaller standard error. Copyright © 2010 John Wiley & Sons, Ltd.
A multiple imputation approach for clustered interval‐censored survival data
Authors: Lam K. F. , Xu Ying , Cheung Tak‐Lun
Published: January 2010

Multivariate interval‐censored failure time data arise commonly in many studies of epidemiology and biomedicine. Analysis of these type of data is more challenging than the right‐censored data. We propose a simple multiple imputation strategy to recover the order of occurrences based on the interval‐censored event times using a conditional predictive distribution function derived from a parametric gamma random effects model. By imputing the interval‐censored failure times, the estimation of the regression and dependence parameters in the context of a gamma frailty proportional hazards model using the well‐developed EM algorithm is made possible. A robust estimator for the covariance matrix is suggested to adjust for the possible misspecification of the parametric baseline hazard function. The finite sample properties of the proposed method are investigated via simulation. The performance of the proposed method is highly satisfactory, whereas the computation burden is minimal. The proposed method is also applied to the diabetic retinopathy study (DRS) data for illustration purpose and the estimates are compared with those based on other existing methods for bivariate grouped survival data. Copyright © 2010 John Wiley & Sons, Ltd.
Breakthrough and future: nanoscale controls of compositions, morphologies, and mesochannel orientations toward advanced mesoporous materials
Authors: Yamauchi Yusuke , Suzuki Norihiro , Radhakrishnan Logudurai , Wang Liang
Published: January 2010

Currently, ordered mesoporous materials prepared through the self‐assembly of surfactants have attracted growing interests owing to their special properties, including uniform mesopores and a high specific surface area. Here we focus on fine controls of compositions, morphologies, mesochannel orientations which are important factors for design of mesoporous materials with new functionalities. This Review describes our recent progress toward advanced mesoporous materials. Mesoporous materials now include a variety of inorganic‐based materials, for example, transition‐metal oxides, carbons, inorganic‐organic hybrid materials, polymers, and even metals. Mesoporous metals with metallic frameworks can be produced by using surfactant‐based synthesis with electrochemical methods. Owing to their metallic frameworks, mesoporous metals with high electroconductivity and high surface areas hold promise for a wide range of potential applications, such as electronic devices, magnetic recording media, and metal catalysts. Fabrication of mesoporous materials with controllable morphologies is also one of the main subjects in this rapidly developing research field. Mesoporous materials in the form of films, spheres, fibers, and tubes have been obtained by various synthetic processes such as evaporation‐mediated direct templating (EDIT), spray‐dried techniques, and collaboration with hard‐templates such as porous anodic alumina and polymer membranes. Furthermore, we have developed several approaches for orientation controls of 1D mesochannels. The macroscopic‐scale controls of mesochannels are important for innovative applications such as molecular‐scale devices and electrodes with enhanced diffusions of guest species. © 2010 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 9: 321–339; 2009: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.200900022
Tricuspid atresia with absent pulmonary valve and intact ventricular septum: intrauterine course and outcome of an unusual congenital heart defect
Authors: Lato K. , Gembruch U. , Geipel A. , Lachmann R. , Schneider M. , Hraska V. , Berg C.
Published: January 2010

The extremely rare syndrome including absent pulmonary valve associated with membranous tricuspid atresia or severe tricuspid stenosis, intact ventricular septum and patent ductus arteriosus has been reported sporadically in the postnatal literature. This cardiac defect is characterized by right ventricular dysplasia with asymmetrical ventricular septal hypertrophy, ventricular septum bulging into the left ventricle, small right ventricular cavity, membranous tricuspid atresia or severe stenosis with abnormal papillary muscles and leaflets and absence of the pulmonary valve leaflets. The only prenatal case reported so far was diagnosed at 33 weeks of gestation and terminated shortly thereafter; the natural history of prenatally diagnosed cases is therefore unknown. We report on the intrauterine course of a case diagnosed at 17 weeks of gestation that had a favorable postnatal outcome after palliation. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
First‐trimester markers for the prediction of pre‐eclampsia in women with a‐priori high risk
Authors: Khalil A. , Cowans N. J. , Spencer K. , Goichman S. , Meiri H. , Harrington K.
Published: January 2010

Objective

To investigate the predictive value of the combination of first‐trimester serum placental protein 13 (PP13), uterine artery Doppler pulsatility index (PI) and pulse wave analysis (augmentation index at a heart rate of 75 beats per min (AIx‐75)), and to evaluate concurrent and contingent strategies using this combination for assessing the risk of pre‐eclampsia in high‐risk women.

Methods

In this nested case–control study, serum PP13, uterine artery mean PI and AIx‐75 were measured at between 11 + 0 and 13 + 6 weeks' gestation in women at increased risk of pre‐eclampsia. For each case of pre‐eclampsia (n = 42), five matched controls were randomly selected from the study group. Gestation specific multiples of the median (MoMs) were adjusted for body mass index, ethnicity, smoking, age and parity. MoMs were compared between cases and controls using the Wilcoxon rank sum test. Sensitivities and specificities were derived from receiver–operating characteristics curves.

Results

Compared with controls, women who developed pre‐eclampsia had lower PP13, higher uterine artery mean PI and higher AIx‐75 (P < 0.001). For a 10% false‐positive rate, the best detection rate for pre‐eclampsia (85.7% (95% CI, 71.5–94.6%)) and pre‐eclampsia requiring delivery before 34 weeks (92.9% (95% CI, 66.1–99.8%)) was achieved by concurrent testing with all three markers. The best contingency screening sequences for pre‐eclampsia were (AIx‐75 → PP13 → mean PI) and (PP13 → AIx‐75 → mean PI), with an 86% detection rate for false‐positive rates of 9 and 10%, respectively. These two sequences would require 410 and 414 tests, respectively, compared with 756 tests in concurrent testing.

Conclusion

Combination of first‐trimester PP13, uterine artery mean PI and pulse‐wave analysis is promising for the prediction of pre‐eclampsia in women at increased @ a‐priori risk and may be useful in clinical practice. Contingency screening achieved similar detection rates to concurrent testing, but required almost 50% fewer tests, making it a more cost‐effective option. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.