bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of crosslinkable latices with poly(vinyl acetate‐co‐VeoVa10) cores and poly(glycidyl methacrylate) shells and online‐FTIR analysis of the amine induced curing process
Authors: Lu Jia , Easteal Allan J. , Edmond Neil
Published: March 2012

Crosslinkable latex particles with poly(vinyl acetate‐co‐VeoVa10) core and poly(glycidyl methacrylate) shell were synthesized by emulsion polymerization. Starved feed and seed emulsion polymerization were used to control the morphology of the core‐shell latex particles. The effect of emulsifier concentration, chain transfer agent, and starved feeding on the core‐shell morphology were investigated. The formation of core‐shell particles was promoted by increasing seed particle numbers and by the starved‐feed condition. Investigation of isothermal crosslinking of the core‐shell latex and the curing agent Anquamine 419 (a modified aliphatic amine), using real‐time Fourier transform infrared spectroscopy, revealed that the cure rate was relatively low at ambient temperature, but curing was complete within about 4 h at 30°C and about 1.5 h at 40°C. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of pressure on the performance of poly(ethylene‐vinyl acetate) as wax deposition inhibitors by calorimetric method
Authors: Vieira Lenise C. , Buchuid Maria B. , Lucas Elizabete F.
Published: March 2012

Chemical inhibition is one of the traditional methods used by the petroleum industry to prevent or correct the problems caused by the formation of organic deposits. In this work, three samples of poly(ethylene‐co‐vinyl acetate)s (EVAs) were added at different concentrations to three different Brazilian crude oils, and their effect on the wax appearance temperature (WAT) and crystallization enthalpy of the oils was evaluated as a function of increasing pressure and the type of saturation gas, using high‐pressure microcalorimetry (HPμDSC). The results show that different copolymer compositions present dissimilar performance in reducing WAT, and, in some cases, an optimum concentration was observed. When rising pressure, a positive influence on the WAT is observed, but the performance of organic deposition inhibitors that are ineffective at atmospheric pressure is not enhanced at higher pressures. On the other hand, additives able to modify the crystallization kinetics of waxes at atmospheric pressure show a synergy when evaluated in the presence of light fractions and under high pressures. HPμDSC analysis is an important tool to optimize the additive concentration to be used in oil fields. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effects of compatibilizers on the mechanical properties of ABS/PLA composites
Authors: Jo Mi Yeong , Ryu Yeon Jong , Ko Jun Hee , Yoon Jin‐San
Published: March 2012

Composites composed of acrylonitrile‐butadiene‐styrene copolymer (ABS) and poly(lactic acid) were prepared to develop ABS‐based automobile console boxes with improved environmental friendliness. ABS/PLA composites without any additives showed extremely poor mechanical properties. However, increase in the content of polybutadiene moiety of ABS and introduction of proper compatibilizer and heat stabilizer enhanced the mechanical properties of ABS/PLA composites significantly. Thermal stabilization effect of the heat stabilizer was assessed by determining the activation energy of thermal degradation, by measuring the molecular weight variation of PLA and by observing the morphology of the fractured surface. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Bycatch susceptibility in pelagic longline fisheries: are albatrosses affected by the diving behaviour of medium‐sized petrels?
Authors: Jiménez Sebastián , Domingo Andrés , Abreu Martin , Brazeiro Alejandro
Published: March 2012

Species of petrels and shearwaters with high diving ability could facilitate the catch of albatrosses in pelagic longline fisheries, because they retrieve bait to the surface from depths that albatrosses cannot reach. Once on the surface, large seabirds such as albatrosses can easily displace smaller species thus gaining access to baited hooks which increases their likelihood of getting caught.

This paper evaluates the extent to which diving species (i.e. Procellaria aequinoctialis, Procellaria conspicillata and Puffinus gravis) increase the susceptibility of albatross to bycatch in pelagic longline fisheries. In 48 sets, attacks on baits were quantified. When more than one bird (of the same or different species) tried to attack the same bait this was defined as a multiple attack.

There were 384 attacks on baits, of which 260 were made by a single individual and 124 by more than one. Multiple attacks were the largest source of bycatch of albatrosses (22 of 27 albatrosses whose attacks were observed).

Of the baits attacked by albatrosses (n = 244), 17% were indirectly facilitated by diving medium‐sized petrels. Considering only the multiple attacks in which albatrosses participated (n = 114), 36% were initiated by these medium‐sized petrels. Eleven (41%) of the albatrosses captured, and whose attacks were observed, resulted from a diving medium‐sized seabird species first having contacted the terminal tackle.

This paper shows that medium‐sized petrels, with a strong ability to dive, increase considerably the access to bait, and indirectly, the incidental bycatch of albatrosses. Observations made in the absence of mitigation measures also provide useful information to improve the performance of tori lines. Based on the seabird behaviour, it is recommended that tori lines should have a minimum aerial coverage of 50 m. Copyright © 2012 John Wiley & Sons, Ltd.
Semi‐Global Output Feedback Stabilization for a Class of Uncertain Nonlinear Systems
Authors: Zhai Junyong , Qian Chunjiang , Du Haibo
Published: March 2012

This paper addresses the problem of semi‐global stabilization by output feedback for a class of nonlinear systems whose output gains are unknown. For each subsystem, we first design a state compensator and use the compensator states to construct a control law to stabilize the nominal linear system without the perturbing nonlinearities. Then, combining the output feedback domination approach with block‐backstepping scheme, a series of homogeneous output feedback controllers are constructed recursively for each subsystem and the closed‐loop system is rendered semi‐globally asymptotically stable.
Focus and Standardization of Sustainability Reporting – A Comparative Study of the United Kingdom and Finland
Authors: Fifka Matthias S. , Drabble Maria
Published: March 2012

Sustainability reporting has attracted significant attention from the business as well as the academic community in recent years. Not only has the latter frequently made recommendations on reporting, it has also extensively examined factors that have an influence on reporting. Several studies have noted differences in the extent and style of reporting across countries, but the influence of specific cultural and socio‐economic environments on reporting has only been given limited consideration so far. It is the goal of this paper to help fill this gap. For this purpose, we examine the sustainability reporting of the 100 largest companies in the United Kingdom and Finland, as both are highly developed countries in North‐Western Europe, but with significantly different cultural and socio‐economic systems. Aside from the extent of reporting and media used, we examine the reporting standards and guidelines applied. Moreover, the focus of disclosure (economic, social or environmental) was investigated, which also brings a new perspective to the academic literature. Our results suggest that the cultural and socio‐economic environment has an impact on the extent of reporting, but with regard to the focus of reporting and the application of standards the results are mixed. A stronger shareholder oriented culture does not lead to a more extensive inclusion of economic issues in sustainability reporting, while the extent of environmental reporting depends on the strength of environmentalism. The impact of cultural and socio‐economic factors on the application of standards, such as the Global Reporting Initiative, appears to be limited. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.
Volumetric intravascular ultrasound assessment of mechanisms and results of stent expansion in heart transplant patients
Authors: Sanidas Elias A. , Maehara Akiko , Mintz Gary S. , Kubo Takashi , Gupta Anuj , Apfelbaum Mark A. , Hakim Diaa , Moses Jeffrey W. , Mancini Donna M. , Rabbani LeRoy E.
Published: March 2012

Background

Percutaneous coronary intervention with stent placement for the treatment of patients with cardiac allograft vasculopathy is common, but data regarding stent behavior in this setting is lacking.

Objectives

We investigated mechanisms and potential differences in stent expansion among transplant patients vs. patients with native coronary artery atherosclerotic disease (“controls”).

Methods

We compared pre‐ and poststent intravascular ultrasound in 12 transplant patients (17 lesions) and 33 control patients (34 lesions) matched according to age (60.1 ± 9.2 years), diabetes mellitus, and lesion location. Planar and volumetric analysis was conducted for every 1 mm at the lesion site as well as the first 5 mm proximal and distal to the stent edge. Focal stent expansion was defined as minimum stent area (MSA) divided by mean reference lumen area. Diffuse stent expansion was defined as mean stent area divided by mean reference lumen area.

Results

Transplant patients had more plaque than “controls” prestenting, but similar MSA and focal and diffuse stent expansion afterwards. The increase in mean lumen area correlated with the increase in mean vessel area in both groups, transplant (R = 0.64, P = 0.008) and controls (R = 0.70, P < 0.0001), but correlated inversely with changes in mean plaque area only in the transplant group (R = 0.55, P = 0.027). There were no differences in calcification between the two groups and no axial plaque distribution from the lesion into the reference segments in either group.

Conclusions

The mechanism of stent expansion in transplant vasculopathy appears to be similar to de novo atherosclerosis—i.e., mainly vessel expansion to achieve similar acute results. © 2012 Wiley Periodicals, Inc.
Sensitivity to outflow boundary conditions and level of geometry description for a cerebral aneurysm
Authors: Ramalho S. , Moura A. , Gambaruto A.M. , Sequeira A.
Published: March 2012

Mathematical models, namely the flow boundary conditions, as well as the detail of the bounding geometry, can highly influence the computed flow field. In this work, an anatomically realistic portion of cerebral vasculature with a saccular aneurysm, and its geometric idealisation, are considered. The importance of the geometric description, namely including the side branches or modelling them as holes in the main vessel, is studied. Several approaches to prescribe the outflow boundary conditions at the side branches are analysed, including the traction‐free condition, zero velocity (hence neglecting the side‐branch), and the coupling with simple zero‐dimensional and one‐dimensional models. Results of the effects of outflow boundary modelling choice on computed haemodynamic parameters are used to identify appropriateness of the models based on the physical interpretation. Estimated range of error‐bars associated to outflow boundary model choice and the level of geometric details are presented for patient‐specific computational haemodynamics, and can serve as invitation for future studies. The zero‐dimensional and one‐dimensional models are shown to provide good representations of the side branches in the case of the clipped geometry. Copyright © 2012 John Wiley & Sons, Ltd.
A Review of Dutch Corporate Sustainable Development Reports
Authors: Asif Muhammad , Searcy Cory , Santos Paulo dos , Kensah David
Published: March 2012

There is increasing pressure on corporations for sustainability reporting. However, current patterns in corporate sustainability reporting are not well understood. Additional research is needed to identify the contents of current reports and to provide a basis for improvement. The aim of this research is to analyze the sustainable development reporting patterns of Dutch companies. A content analysis of Dutch sustainability reports was conducted. The findings show that the contents of Dutch sustainability reports vary widely. While some areas in these reports are well developed, others – such as the use of cross‐cutting indicators, linking sustainability initiatives with broader public policy, future reporting directions, systematic presentation of data, and discussion of non‐conformances – require significant improvement. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment
Determinants of GRI G3 Application Levels: The Case of the Fortune Global 500
Authors: Legendre Stéphane , Coderre François
Published: March 2012

The objectives of this research are to analyze the determinants for the adoption of the Global Reporting Initiative (GRI) G3 guidelines and GRI G3 application levels (undeclared, C, C+, B, B+, A, A+). Content analysis of the 2009 sustainability reports published by the world's 500 largest companies (Fortune Global 500) was conducted. Based on legitimacy theory and signalling theory, the study yielded two main findings. First, the binary logistic regression reveals that the adoption of GRI G3 guidelines is influenced by company size, profitability, business culture of a country, and industry. These results are consistent with past research on the factors influencing sustainability reporting. Second, the ordinal logistic regression shows that the GRI G3 application level is influenced by the industry in which a firm operates but not by company size, profitability or business culture of a country. In high‐risk industries, the GRI G3 application level is more likely to be considered as a signal to manage the reputational risk of the companies. Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment.
On the delay of single‐electron logic devices
Authors: Hoekstra J.
Published: March 2012

Recent research on the modeling of switching speed in single‐electron tunneling (SET) logic devices suggests that the delay in SET logic devices increases with a decreasing number of electrons involved in the logic operation. This result is based on the stochastic model of a sequence of tunnel events and on the so‐called orthodox theory (OT) of single electronics. In fact, it predicts that the SET gate delay in really single‐electron logic gates (those in which the logic operation is performed by a SET event) is significantly degraded and might even rule out such logic. However, as is shown in this paper, the results are only a consequence of the modeling of SET devices with the OT, not of the applied correct statistical simulation model. If we combine this stochastic model and the modeling of SET devices with the impulse circuit model, this degradation does not appear, due to continuous charging of the tunneling junction. And SET logic operations might be still possible for real single‐electron logic. Copyright © 2012 John Wiley & Sons, Ltd.
Malononitrile‐Assisted Highly Chemoselective Bismuth Triflate Catalyzed Conjugate Reduction of α,β‐Unsaturated Ketones
Authors: Shang Jun‐Yan , Li Fei , Bai Xing‐Feng , Jiang Jian‐Xiong , Yang Ke‐Fang , Lai Guo‐Qiao , Xu Li‐Wen
Published: March 2012

A very simple, direct, bismuth‐catalyzed conjugate reduction protocol that allows for the catalytic regioselective formation of substituted ketones from enones under mild conditions has been developed. We have shown for the first time that the combined poly(methylhydro)siloxane‐malononitrile system can serve as an efficient reductant/reagent in 1,4‐conjugate reduction of enones. The regioselectivity, efficiencies, and experimental simplicity of the present method complements the more complex methods previously employed in copper or palladium‐catalyzed reduction. This method should prove attractive because of its mild reaction conditions and the interesting chemistry of combining the use of poly(methylhydro)siloxane and malononitrile for selective reduction.
Ethanol production from date syrup with flocculent yeast: Optimization study
Authors: Ali Hayder Kh. Q. , Zulkali Mohammed M.D.
Published: March 2012

The current study was an attempt to produce ethanol from date syrup by using flocculent yeast, Saccharomyces uvarum. Due to its availability and cheap, the date syrup was used as the main carbon source. The central composite design (CCD) was applied to determine the optimum conditions of fermentation parameters in order to achieve high ethanol production. The selected parameters, fermentation temperature, concentration of date syrup sugar, and feed flow rate, were optimized through CCD. The study was conducted in a pilot scale plant tower fermenter. The highest conversion of the sugars was 95.75%, where it was achieved under the following optimum fermentation conditions: 29.06°C, sugar concentration of 55.00 mg/mL, and the feed flow rate of 100 mL/h (dilution rate 0.133 h−1). The flocculent yeast seemed to have a significant impact on the continuous ethanol production process due to its flocculent behavior. The phenomenon seemed to reduce the washout of cells with the product. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 818–823, 2013
Thermal and mechanical properties of light‐weight concrete exposed to high temperature
Authors: Felicetti Roberto , Gambarova Pietro G. , Bamonte Patrick
Published: March 2012

The extensive studies devoted so far to normal‐strength light‐weight aggregate concrete (LWAC or LWC) have exhaustively clarified its behaviour in ordinary conditions. However, the introduction of high‐performance light‐weight aggregate concrete (HPLWAC or HPLWC), containing such pozzolanic components as microsilica and fly ash, raises some concerns, for instance about the behaviour at high temperature and after cooling. To investigate the temperature‐induced mechanical damage, both in compression and tension, of silica‐fume HPLWCs, a systematic research program was carried out at the Politecnico di Milano on materials residual behaviour (testing after cooling down to room temperature). Three concrete mixes (Normal‐Strength Concrete = NSC, fc20 = 30 MPa; Light‐Weight Concrete = LWC, fc20 ≈ 40 MPa; and High‐Performance Light‐Weight Concrete = HPLWC, fc20 ≈ 60 MPa), five temperature levels (20, 105, 250, 500 and 750 °C, no loads applied during heating), one thermal state (after cooling), three nominally‐equal tests for each case (for repeatability) were planned, bringing the total number of specimens to 120 (45 tested in compression, 45 in direct tension and 30 in indirect tension by splitting). At the same time, the thermal diffusivity of the materials was evaluated up to 750 °C (4 specimens). The results show that HPLWC is somewhat more temperature‐sensitive than both NSC and LWC, but this extra sensitivity is counterbalanced by HPLWC's lower diffusivity. Its better insulation properties are advantageous for the concrete in axially‐loaded members and for the tension bars in the beams, as demonstrated by the thermo‐mechanical analyses of three typical R/C sections (rectangular, T and slab sections) carried out in the second part of the paper. Copyright © 2012 John Wiley & Sons, Ltd.
A Bayesian Integrative Genomic Model for Pathway Analysis of Complex Traits
Authors: Fridley Brooke L. , Lund Steven , Jenkins Gregory D. , Wang Liewei
Published: March 2012

With new technologies, multiple types of genomic data are commonly collected on a single set of samples. However, standard analysis methods concentrate on a single data type at a time and ignore the relationships between genes, proteins, and biochemical reactions that give rise to complex phenotypes. In this paper, we propose a novel integrative model to incorporate multiple types of genomic data into an association analysis with a complex phenotype. The method combines path analysis and stochastic search variable selection into a Bayesian hierarchical model that simultaneously identifies both direct and indirect genomic effects on the phenotype. Results from a simulation study and application of the Bayesian model to a pharmacogenomic study of the drug gemcitabine demonstrate greater sensitivity to detect genomic effects in some simulation scenarios, when compared to the standard single data type analysis. Further research is required to extend and modify this integrative modeling framework to increase computational efficiency to best capitalize on the wealth of information available across multiple genomic data types. Genet. Epidemiol. 36:352–359, 2012. © 2012 Wiley Periodicals, Inc.
Multimodal optical imaging with multiphoton microscopy and optical coherence tomography
Authors: Tang Shuo , Zhou Yifeng , Ju Myeong Jin
Published: March 2012

Two types of combined multiphoton microscopy and optical coherence tomography (MPM/OCT) are compared for multimodal optical imaging. Single‐scale multiphoton microscopy and optical coherence microscopy (MPM/OCM) is shown to acquire multiple contrasts from MPM and OCT simultaneously. Multi‐scale MPM/OCT is shown to provide multiple field‐of‐views (FOVs), where OCT provides tissue level imaging and MPM provides cellular level imaging. In both types, the MPM includes two channels which are two‐photon excited fluorescence (TPEF) and second harmonic generation (SHG). Representative images using each system are demonstrated on biological specimens. A detailed comparison of the two types of MPM/OCT shows that each system has its own pros and cons. MPM/OCM is high‐resolution but with limited FOV, and OCM may or may not provide additional information than MPM depending on the samples. Multi‐scale MPM/OCT can change FOV but need both low and high NA objectives. For future development, the two types of MPM/OCT can be further integrated to achieve both functions on a single system. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Intercoupling surface plasmon resonance and diffusion reflection measurements for real‐time cancer detection
Authors: Ankri Rinat , Meiri Amihai , Lau Shemuel I. , Motiei Menachem , Popovtzer Rachela , Fixler Dror
Published: March 2012

Spatial diffusion reflection (DR) measurements of gold nanorods (GNR) were recently suggested as a simple and highly sensitive non‐invasive and non‐ionizing method for real‐time cancer detection. In this paper we demonstrate that wavelength dependent DR measurements enable the spectral red‐shift observation of highly concentrated GNR. By conjugating targeting moieties to the GNR, large density of GNR can specifically home onto cancer cells. The inter‐particle plasmon resonance pattern of the highly concentrated GNR leads to an extension and a red‐shift (Δλ) in the absorption spectrum of the concentrated GNR. Dark‐field microscopy was used in order to measure the expected Δλ in different GNR concentrations in vitro. Double‐wavelength DR measurements of tissue‐like phantoms and tumor bearing mice containing different GNR concentrations are presented. We show that the DR profile of the highly concentrated GNR directly correlate with the spectral extension and red‐shift. This presented work suggests that wavelength dependent DR method can serve as a promising tool for real‐time superficial tumor detection. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Assessment of the mass, length, center of mass, and principal moment of inertia of body segments in adult males of the brown anole (Anolis sagrei) and green, or carolina, anole (Anolis carolinensis)
Authors: Legreneur Pierre , Homberger Dominique G. , Bels Vincent
Published: March 2012

This study provides a morphometric data set of body segments that are biomechanically relevant for locomotion in two ecomorphs of adult male anoles, namely, the trunk‐ground Anolis sagrei and the trunk‐crown Anolis carolinensis. For each species, 10 segments were characterized, and for each segment, length, mass, location of the center of mass, and radius of gyration were measured or calculated, respectively. The radii of gyration were computed from the moments of inertia by using the double swing pendulum method. The trunk‐ground A. sagrei has relatively longer and stockier hindlimbs and forelimbs with smaller body than A. carolinensis. These differences between the two ecomorphs demonstrated a clear relationship between morphology and performance, particularly in the context of predator avoidance behavior, such as running or jumping in A. sagrei and crypsis in A. carolinensis. Our results provide new perspectives on the mechanism of adaptive radiation as the limbs of the two species appear to scale via linear factors and, therefore, may also provide explanations for the mechanism of evolutionary changes of structures within an ecological context. J. Morphol., 2012. © 2012 Wiley Periodicals, Inc.
GC‐MSn and LC‐MS/MS couplings for the identification of degradation products resulting from the ozonation treatment of Acetochlor
Authors: Bouchonnet Stéphane , Bourcier Sophie , Souissi Yasmine , Genty Christophe , Sablier Michel , Roche Pascal , Boireau Véronique , Ingrand Valérie
Published: March 2012

The degradation of the chloracetamide herbicide acetochlor has been studied under simulated ozonation treatment plant conditions. The degradation of acetochlor included the formation of several degradation products that were identified using GC/ion‐trap mass spectrometry with EI and CI and HPLC/electrospray‐QqTOF mass spectrometry. Thirteen ozonation products of acetochlor have been identified. Ozonation of the deuterated herbicide combined to MSn and high‐resolution mass measurement allowed effective characterization of the degradation products. At the exception of one of them, the product B (2‐chloro‐2', ethyl‐6', methyl‐acetanilide), none of the identified degradation products has been already reported in the literature.

Post‐ozonation kinetics studies revealed that the concentrations of most degradation products evolved noticeably with time, particularly during the first hours following the ozonation treatment. This raises concerns about the fate of degradation products in the effluents of treatment plants and suggests the need for a better control on these products if their toxicity was demonstrated. Copyright © 2012 John Wiley & Sons, Ltd.
Identification of isomeric 5‐hydroxytryptophan‐ and oxindolylalanine‐containing peptides by mass spectrometry
Authors: Todorovski Toni , Fedorova Maria , Hoffmann Ralf
Published: March 2012

Cells continuously produce reactive oxidative species that can modify all cellular components. In proteins, for example, cysteine, methionine, tryptophan (Trp), and tyrosine residues are particularly prone to oxidation. Here, we report two new approaches to distinguish two isomeric oxidation products of Trp residues, i.e. 5‐hydroxytryptophan (5‐HTP) and oxindolylalanine (Oia) residues, in peptides. First, 2‐nitrobenzenesulfenyl chloride, known to derivatize Trp residues in position 2 of the indole ring, was used to label 5‐HTP residues. The mass shift of 152.98 m/z units allowed identifying 5‐HTP‐ besides Trp‐containing peptides by mass spectrometry, whereas Oia residues were not labeled. Second, fragmentation of the Oia‐ and 5‐HTP‐derived immonium ions at m/z 175.08 produced ions characteristic for each residue that allowed their identification even in the presence of y1 ions at m/z 175.12 derived from peptides with C‐terminal arginine residues. The pseudo MS3 spectra acquired on a quadrupole time‐of‐flight hybrid mass spectrometer displayed two signals at m/z 130.05 and m/z 132.05 characteristic for Oia‐containing peptides and a group of six signals (m/z 103.04, 120.04, 130.04, 133.03, 146.04, and 148.04) for 5‐HTP‐cointaining peptides. In both cases, the relative signal intensities appeared to be independent of the sequence providing a specific fingerprint of each oxidative modification. Copyright © 2012 John Wiley & Sons, Ltd.
Platinum‐Based Poly(Aryleneethynylene) Polymers Containing Thiazolothiazole Group with High Hole Mobilities for Field‐Effect Transistor Applications
Authors: Yan Lei , Zhao Yan , Wang Xiaohui , Wang Xing‐Zhu , Wong Wai‐Yeung , Liu Yunqi , Wu Weiping , Xiao Qingzhen , Wang Guo , Zhou Xuan , Zeng Wei , Li Chengxi , Wang Xiaoyu , Wu Hongbin
Published: March 2012

Two solution‐processable platinum‐acetylide polymers functionalized with the electron‐deficient thiazolothiazole spacer are synthesized and show absorption features spanning from 320 to 600 nm and optical bandgaps of 2.15 and 2.05 eV. The spin‐coated polymer thin films of both materials exhibit p‐channel field‐effect charge transport characteristics with impressive peak field‐effect charge‐carrier mobilities of (2.1–2.8) × 10−2 cm2 V−1 s−1 and on/off ratios of (0.8–1.0) × 105 for the holes. The high hole mobility value reported for one of the polymers is among the highest reported for metallopolyynes to date. It is also shown that the hole mobility can be notably increased by extending the conjugation length of the chain from the monothienyl to the bithienyl segment on each side of the thiazolothiazole ring.
A direct complementarity approach for the elastoplastic analysis of plane stress and plane strain structures
Authors: Tangaramvong S. , Tin‐Loi F. , Song Ch.
Published: March 2012

This paper presents a direct complementarity approach for carrying out the elastoplastic analysis of plane stress and plane strain structures. Founded on a traditional finite‐step formulation, our approach, however, avoids the typically cumbersome implementation of iterative predictor–corrector procedures associated with the ubiquitous return mapping algorithm. Instead, at each predefined step, the governing formulation—cast in its most natural mathematical programming format known as a mixed complementarity problem—is directly solved by using a complementarity solver run from within a mathematical modeling system. We have chosen the industry‐standard General Algebraic Modeling System/PATH mixed complementarity problem solver that is called from within the General Algebraic Modeling System environment. We consider both von Mises and Tresca materials, with perfect or hardening (kinematic and isotropic) behaviors. Our numerical tests, five (benchmark) examples of which are presented in this paper, have been carried out using models constructed from the mixed finite element of Capsoni and Corradi (Comput. Methods Appl. Mech. Eng. 1997; 141:67–93), which beneficially offers a locking‐free behavior and coarse‐mesh accuracy. The results indicate, in addition to an isochoric locking‐free behavior, good accuracy and the ability to circumvent the difficult singularity problem associated with the corners of Tresca yield surfaces. Copyright © 2012 John Wiley & Sons, Ltd.
A back propagation through time‐like min–max optimal control algorithm for nonlinear systems
Authors: Milić Vladimir , Kasać Josip , Majetić Dubravko
Published: March 2012

This paper presents a conjugate gradient‐based algorithm for feedback min–max optimal control of nonlinear systems. The algorithm has a backward‐in‐time recurrent structure similar to the back propagation through time (BPTT) algorithm. The control law is given as the output of the one‐layer NN. Main contribution of the paper includes the integration of BPTT techniques, conjugate gradient methods, Adams method for solving ODEs and automatic differentiation, to provide an effective, numerically robust algorithm for solving optimal min–max control problems. The proposed algorithm is evaluated on a robotic system with two DOFs. Copyright © 2012 John Wiley & Sons, Ltd.
Comparative effectiveness of statin plus fibrate combination therapy and statin monotherapy in patients with type 2 diabetes: use of propensity‐score and instrumental variable methods to adjust for treatment‐selection bias
Authors: Suh Hae Sun , Hay Joel W. , Johnson Kathleen A. , Doctor Jason N.
Published: March 2012

Purpose

Type 2 diabetes is associated with increased cardiovascular risk. The comparative effectiveness of statin plus fibrate combination therapy and statin monotherapy in reducing risk of cardiovascular disease in real‐world settings is unknown.

Methods

A retrospective database analysis was performed using a large managed care claims database of patients identified with type 2 diabetes based on diagnosis codes from January 2002 through December 2003 and continuously enrolled for the entire study period, 5.5 years. A statin plus fibrate combination therapy group (patients who used statins less than 6 months and augmented with fibrates for more than 6 months) and a statin monotherapy group (patients who used statins persistently) among patients with type 2 diabetes were followed for 3 years to examine the relationship between the intervention and cardiovascular events using a multivariable logistic regression model, propensity score method, and instrumental variable approach.

Results

The statin plus fibrate combination therapy group of 318 and the statin monotherapy group of 9928 were identified from 75 515 diabetics. After adjusting for factors that can impact cardiovascular outcomes, the combination therapy group did not significantly experience a reduction in cardiovascular disease, as compared with the statin monotherapy group (OR = 0.77; p = 0.083). The statin plus fibrate combination therapy group was significantly associated with a reduction in cardiovascular events after propensity matching (OR = 0.53; p = 0.002). Using the physician prescribing preference instrument to adjust for unmeasured confounding, we did not find evidence that subjects in the statin plus fibrate combination therapy group versus stain monotherapy group experienced a significant reduction in cardiovascular events (p = 0.124).

Conclusions

We did not find a difference in effectiveness regarding cardiovascular outcomes between the statin plus fibrate combination therapy and the statin monotherapy after controlling for hidden bias. Copyright © 2012 John Wiley & Sons, Ltd.
Application of thiol‐ene click chemistry to preparation of functional polyethylene with high molecular weight and high polar group content: Influence of thiol structure and vinyl type on reactivity
Authors: Hong Miao , Liu San‐Rong , Li Bai‐Xiang , Li Yue‐Sheng
Published: March 2012

A series of functional polyethylenes have been simply and efficiently synthesized via the combination of regioselective ethylene/5‐vinyl‐2‐norbornene (VNB) copolymerization using [PhNC(CF3)CHCO(Ph)]2TiCl2 catalyst and following ultraviolet light initiated thiol‐ene click reaction. On treatment of ethylene/VNB copolymer with different thiols including mercaptoethanol, 1‐thioglycerol, methyl mercaptoacetate, methyl mercaptopropionate, 2‐mercaptoethylamine, mercaptoacetic acid, and mercaptopropanoic acid, various polar groups have been successfully introduced into the polyethylene. Except 2‐mercaptoethylamine, the functionalizations are quite efficient with the degree of functionalization higher than 94%, which is independent of thiol structure and double bond content. The content of polar group in functional polyethylene can be tuned in a wide range of 0–30 mol %. Gel permeation chromatography profiles indicate all functional polyethylenes that have very high molecular weights (160–336 kg/mol) with homogeneous formation. Besides, systematic investigation of the influence of vinyl type and thiol structure on reactivity has been also carried out. By treatment of mercaptoethanol with different copolymers (ethylene/VNB, ethylene/5‐ethylidene‐2‐norbornene, and ethylene/dicyclopentadiene copolymer), the order of vinyl reactivity can be summarized as terminal > internal > cyclic double bond. For different thiols, the reactivity has the sequence of SHCH2COOH > SHCH2COOCH3 > SHCH2CH2COOH > SHCH2CH2COOCH3 > SHCH2CH(OH)CH2OH > SHCH2CH2OH > SHCH2CH2NH2, which is depended on the solubility and the electron‐withdrawing inductive effect of polar group. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
Naphthodioxinone‐1,3‐benzodioxole as photochemically masked one‐component type II photoinitiator for free radical polymerization
Authors: Kumbaraci Volkan , Aydogan Binnur , Talinli Naciye , Yagci Yusuf
Published: March 2012

A 1,3‐benzodioxole derivative of naphthodioxinone, namely 2‐(benzo[d][1,3]dioxol‐5‐yl)‐9‐hydroxy‐2‐phenyl‐4H‐naphtho[2,3‐d][1,3]dioxin‐4‐one was synthesized and characterized. Its capability to act as caged one‐component Type II photoinitiator for free radical polymerization was examined. Upon irradiation, this photoinitiator releases 5‐benzoyl‐1,3‐benzodioxole possessing both benzophenone and 1,3‐dioxole groups in the structure as light absorbing and hydrogen donating sites, respectively. Subsequent photoexcitation of the benzophenone chromophore followed by hydrogen abstraction generates radicals capable of initiating free radical polymerization of appropriate monomers. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
On supermembrane supercurrent and special minimal supergravity
Authors: Bandos I.A. , Meliveo C.
Published: March 2012

In this contribution we review recent progress in studying the superfield Lagrangian description of the interacting system of D = 4 𝒩 = 1 supergravity (SUGRA) and supermembrane in the frame of Wess–Zumino superfield approach. The off‐shell formulation of simple SUGRA by Ovrut and Waldram, which we prefer to call `special minimal supergravity', is appropriate for this purpose. We discuss the superfield form of this formulation, showing how the basic variations of minimal SUGRA are restricted by the conditions of the existence of a three‐form potential C3 in its superspace. We also describe the effect of dynamical generation of cosmological constant, known to be characteristic for this formulation of SUGRA, in its superfield form, and notice that the same effect had been found by Ogievetsky and Sokatchev in their formulation of SUGRA as a theory of axial vector superfield. We vary the supermembrane action with respect to the special minimal SUGRA superfields (basic variations) and obtain the supercurrent superfields as well as the supergravity superfield equations with the supermembrane contributions.
Polarized electroluminescence from silicon nanostructures
Authors: Bagraev Nikolay , Danilovsky Eduard , Gets Dmitry , Klyachkin Leonid , Kudryavtsev Andrey , Kuzmin Roman , Malyarenko Anna , Mashkov Vladimir
Published: March 2012

We present the first findings of the circularly polarized electroluminescence (CPEL) from silicon nanostructures which are the p‐type ultra‐narrow silicon quantum well (Si‐QW) confined by δ‐barriers heavily doped with boron. The CPEL dependences on the forward current and lateral electric field show the circularly polarized light emission which appears to be caused by the exciton recombination through the negative‐U dipole boron centers at the Si‐QW–δ‐barriers interface with the assistance of phosphorus donors. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and characterization of new monomers and oligomers containing pyrimidine core
Authors: Abashev Georgiy , Sosnin Evgeniy , Shklyaeva Elena , Ustalova Tatiana , Osorgina Irina , Romanova Valentina
Published: March 2012

There has been prepared and eletro(spectroelectro)chemically studied a series of new pyrimidine‐based monomers and polymers containing carbazole moieties. The electrochemically obtained films were found to become reversibly green‐colored under the influence of an applied anodic potential. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Anomalous dielectric behaviour and thermal motion of water molecules incorporated in porous crystals
Authors: Zhou Biao , Kobayashi Akiko , Wang Zhe‐Ming , Long La‐Sheng , Kobayashi Hayao
Published: March 2012

By combining physical measurements and molecular dynamics (MD) simulations, we investigated the dielectric properties of guest water molecules confined in the channels of porous coordination polymer crystals. [Ln2Cu3(IDA)6] · n H2O (Ln = La, Nd, Sm, Gd, Ho, Er; IDA = [NH(CH2COO)2]2‐; n ≈ 9) exhibited large dielectric constants (ε) and antiferroelectric behaviours at high temperatures. In particular, ε of [Sm2Cu3(IDA)6] · n H2O became as large as 1300 at around 400 K. In addition, the crystals exhibited broad dielectric peaks at around 170 K below which ε became very small, indicating the freezing of the positional freedom of guest water molecules. The dielectric constants of [Cu(IN)2] · n H2O (IN = (C6H4NO2)‐) also increased fairly rapidly with temperature, which attributed to the melting of the hydrogen‐bonded water chain system. These temperature dependences of ε were consistent with the results of MD simulation (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Description of conductivity steps in polymer and other materials by functions of p‐adic argument
Authors: Zharkov Viktor
Published: March 2012

We study the quantum jumps of physical quantities in a strongly correlated many electron systems based on a new p‐adic functional integral approach. It is shown that a description in terms of the p‐adic numbers leads to the fractal behavior and can describe the quantum jumps in the conductivity and magnetization as a function of voltage and magnetic field in nanotechnology devices and low‐dimensional strongly correlated organic metals and other materials. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Radical cation salts of CLEDO‐TTF with octahedral anions
Authors: Ishikawa Manabu , Nakano Yoshiaki , Uruichi Mikio , Yakushi Kyuya , Yamochi Hideki
Published: March 2012

A new π‐donor, 4‐chloro‐4′,5′‐ethylenedioxytetrathiafulvalene (CLEDO‐TTF) was synthesized from 4‐methoxycarbonyl‐4′,5′‐ethylenedioxytetrathiafulvalene in the yield of 85%. In the crystal of neutral molecule, the head‐to‐head type uniform stacking column, in which the donor molecules are related by a unit cell translation, was formed. The electrocrystallization of CLEDO‐TTF with PF6 afforded two kinds of 1:1 salts of purple rods and green plates as miner species. In both 1:1 salts, the head‐to‐tail dimers with ring‐over‐ring overlapping mode were formed. Geometrically, the dimers were included in slipped stacking column in the purple rod salt, while the two‐dimensional network was formed in the green plate salt. The significant steric effect of chlorine atom along the molecular long axis was confirmed by the intermolecular arrangement in the green plate salt, in which the chlorine atom is faced to the hydrogen atom of the neighbouring donor along the long axis. The normal mode analyses were carried out for the neutral and monocationic CLEDO‐TTF, which agreed well with the observed Raman spectra. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Phase transition behavior in the mixed crystal of pristine and mono‐methyl substituted EDO‐TTF
Authors: Hiramatsu Takaaki , Murata Tsuyoshi , Shao Xiangfeng , Nakano Yoshiaki , Yamochi Hideki , Uruichi Mikio , Yakushi Kyuya , Tanaka Koichiro
Published: March 2012

We report the mixed crystals of pristine and monomethyl substituted EDO‐TTF with PF6, [(EDO‐TTF)1–x(MeEDO ‐TTF)x ]2PF6 (x = mole fraction of MeEDO‐TTF, x = 0.095, 0.210, 0.345). While three mechanisms of Peierls, charge order (CO), and anion order (AO) transiton concurrently cause the metal‐insulator (M‐I) transion at about 280 K in the pristine crystal (x = 0), the cooperativity was modulated in the mixed crystals. The mixed crystals of x = 0.095‐0.210 showed the M‐I transition originated only from Peierls mechanism and that of x = 0.345 did not show the unit cell‐doubling down to 100 K. The analysis of anion motion revealed that AO transition does not cooperate with Peierls transition for the mixed crystals with intermediate x. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Vibrational spectroscopic study of carbon nano‐onions coated with polyaniline
Authors: Łapiński Andrzej , Dubis Alina T. , Plonska‐Brzezinska Marta E. , Mazurczyk Julita , Breczko Joanna , Echegoyen Luis
Published: March 2012

Carbon nano‐onions (CNOs) coated with polyaniline (PANI) were synthesized by using an in situ chemical oxidative polymerization method. Two types of PANI were used in our investigations: the green protonated conducting emeraldine (PANI‐ES) and nonconducting blue emeraldine base (PANI‐EB). Vibrational spectroscopic study of the composites containing carbon nano‐onions and polyaniline were carried out using infrared absorption and Raman spectroscopy. The spectra of carbon nano‐onions with polyaniline and reference molecules were recorded. For some of the investigated molecules and/or their fragments theoretical analysis of normal mode calculations were performed. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First‐principles study of vanadium adsorption and diffusion on the AlN(0001) surface
Authors: Rivera‐Julio Jagger , López‐Pérez William , González‐Hernández Rafael , Escorcia‐Salas Gene E. , Sierra‐Ortega José
Published: March 2012

We have performed spin‐polarized first‐principles calculations to explore the vanadium adsorption and diffusion on the AlN(0001)‐(2 × 2) surface. The calculations were performed using the generalized gradient approximation with ultrasoft pseudopotential within the density functional theory. The surface is modeled using the repeated slabs approach. To study the most favorable reconstruction with vanadium adatom, we considered H3, T4, and T1 high‐symmetry sites. We found that the most energetically favorable structure corresponds to the V‐T4 reconstruction or the vanadium adatom located at the hcp‐hollow (T4) site whereas the vanadium adsorption on‐top of a aluminium atom (T1 position) is energetically unfavorable. The vanadium diffusion on surface shows an activation energy of 0.262 eV (T4–H3). The resultant reconstruction of the vanadium adsorption on AlN(0001)‐(2 ×2) surface presents a lateral relaxation of some hundredth of Å in the most stable site. The comparison between the density of states of the AlN(0001) clean surface and with vanadium adatom is also examined. © 2012 Wiley Periodicals, Inc.
Novel product ions of 2‐aminoanilide and benzimidazole Ag(I) complexes using electrospray ionization with multi‐stage tandem mass spectrometry
Authors: Johnson Byron S. , Burinsky David J. , Burova Svetlana A. , Davis Roman , Fitzgerald Russ N. , Matsuoka Richard T.
Published: March 2012

RATIONALE

The 2‐aminoaniline scaffold is of significant value to the pharmaceutical industry and is embedded in a number of pharmacophores including 2‐aminoanilides and benzimidazoles. A novel application of coordination ion spray mass spectrometry (CIS‐MS) for interrogating the silver ion (Ag+) complexes of a homologous series of these compounds using multi‐stage tandem mass spectrometry is described. Unlike the ubiquitous alkali metal ion complexes, Ag+ complexes of 2‐aminoanilides and benzimidazoles were found to yield [M – H]+ ions in significant abundance via gas‐phase elimination of the metal hydride (AgH) resulting in unique product ion cascades.

METHODS

Sample introduction was by liquid chromatography with mass spectrometry analysis performed on a hybrid linear ion trap/orbitrap instrument capable of high‐resolution measurements.

RESULTS

Rigorous structural characterization by multi‐stage tandem mass spectrometry using [M + H]+, [M – H]– and [M – H]+ precursor ions derived from ESI and CIS experiments was performed for the homologous series of 2‐aminoanilide and benzimidazole compounds. A full tabular comparison of structural information resulting from these product ion cascades was produced.

CONCLUSIONS

Multi‐stage tandem mass spectrometry of [M – H]+ ions resulting from Ag+ complexes of 2‐aminoanilides and benzimidazoles in CIS‐MS experiments produced unique product ion cascades that exhibited complementary structural information to that obtained from tandem mass spectrometry of [M + H]+ and [M – H]– ions by electrospray ionization (ESI). These observations may be broadly applicable to other compounds that are observed to form Ag+ complexes and eliminate AgH. Copyright © 2012 John Wiley & Sons, Ltd.