bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical properties of compatibilized nylon 6/polypropylene blends; studies of the interfacial behavior through an emulsion model
Authors: Huber Tim , Misra Manjusri , Mohanty Amar K. 
Published: April 2014

ABSTRACTThe high interfacial tension between two immiscible phases in a polymer blend often prevents a homogenous stress distribution. Therefore, blends of Nylon 6 (Ny6) and polypropylene (PP) were compatibilized using two commercially available types of PP grafted with maleic anhydride (MAPP) with a low (∼2 %) and a high (∼7%) grade of maleation. The interfacial tension of compatibilized and non‐compatibilized blends of PA6/PP was calculated from the recoded data of oscillatory rheological measurements using an emulsion model. Both compatibilizers showed similar improvements in tensile strength of up to 25%, but the one low maleation grade compatibilizer showed improved impact properties (>200%). It could be shown that, despite, being more effective in reducing the interfacial tension, using a high grade of maleation in the compatibilizer causes no additional improvement in tensile strength over a low grade of maleation and even has a negative effect on the PA6/PP blend impact strength. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40792.
Generic roll‐to‐roll compatible method for insolubilizing and stabilizing conjugated active layers based on low energy electron irradiation
Authors: Helgesen Martin , Carlé Jon E. , Helt‐Hansen Jakob , Miller Arne , Krebs Frederik C. 
Published: April 2014

ABSTRACTIrradiation of organic multilayer films is demonstrated as a powerful method to improve several properties of polymer thin films and devices derived from them. The chemical cross‐linking that is the direct result of the irradiation with ∼100 keV electrons is fast and has a penetration power compatible with thin plastic foils of one to two hundreds of microns typical of devices explored in organic electronics. We demonstrate here that active layers and complete devices can be subjected to electron irradiation‐induced cross‐linking thus facilitating multilayer solvent processing and morphological stability. The method is fast, generic, contactless, and fully compatible with high‐speed roll‐to‐roll processing of i.e. polymer solar cells at web speeds in excess of 60 m min−1. We employ fully printed, flexible, and foil‐based indium‐tin‐oxide free polymer solar cells in this study to demonstrate the technique. We also demonstrate that polymer solar cells are exceptionally stable towards ionizing radiation and find that doses as high as 100 kGy can be used before any significant decrease in performance is observed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40795.Together with Mokarian‐Tabari et al., J. Appl. Polym. Sci. (2014) 131, 40798, doi:10.1002/app.40798, this article is part of a Special Issue on Polymers for Microelectronics. The remaining articles appear in J. Appl. Polym. Sci. (2014) volume 131, issue 24. This note was added on 1st July 2014.
Poly(l‐histidine)‐containing polymer bioconjugate hybrid materials as stimuli‐responsive theranostic systems
Authors: Johnson Renjith P. , John Johnson V. , Kim Il 
Published: April 2014

ABSTRACTFor decades, researchers have aspired to develop materials for noninvasive treatment and monitoring of pathological conditions. Various organs, tissues, subcellular compartments, and their pathophysiological states can be characterized by their pH values. pH‐dependent intracellular tumor targeting has received particular attention due to the unique acidic environment of the solid tumors created by physiological and metabolical abnormalities. Responsive nanocarriers, when exposed to these pH stimuli, respond quickly to the physicochemical changes by undergoing structural deformations, such as swelling and phase transition, which favors the drug release specifically at the diseased site. Recently, researchers have developed several new poly(L‐histidine) (p(His))‐based pH responsive systems for sustained drug release and molecular targeting. This review focuses on the p(His)‐based pH responsive nanocarriers, which are utilized in biomedical applications such as anti‐cancer drug delivery and nucleic acid delivery. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40796.
Molecular modeling approach to the prediction of mechanical properties of silica‐reinforced rubbers
Authors: Hentschke Reinhard , Hager Jonathan , Hojdis Nils W. 
Published: April 2014

ABSTRACTRecently, we have suggested a nanomechanical model for dissipative loss in filled elastomer networks in the context of the Payne effect. The mechanism is based on a total interfiller particle force exhibiting an intermittent loop, due to the combination of short‐range repulsion and dispersion forces with a long‐range elastic attraction. The sum of these forces leads, under external strain, to a spontaneous instability of “bonds” between the aggregates in a filler network and attendant energy dissipation. Here, we use molecular dynamics simulations to obtain chemically realistic forces between surface modified silica particles. The latter are combined with the above model to estimate the loss modulus and the low strain storage modulus in elastomers containing the aforementioned filler‐compatibilizer systems. The model is compared to experimental dynamic moduli of silica filled rubbers. We find good agreement between the model predictions and the experiments as function of the compatibilizer's molecular structure and its bulk concentration. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40806.
Selective oxidation of kraft lignin over zeolite‐encapsulated Co(II) [H4]salen and [H2]salen complexes
Authors: Zhou Xue‐Fei 
Published: April 2014

ABSTRACTThe Co([H4]salen) and the corresponding Co([H2]salen) complexes were encapsulated in NaY by the impregnation (IM) and flexible ligand ship‐in‐a‐botttle (SB) method for oxidation of kraft lignin to obtain chemical compounds. The neat and encapsulated complexes were characterized by XRD, FTIR, DR UV–Vis spectroscopy and BET, which showed the observed changes in the molecular structure to be correlated to the enhanced activity of the complexes. GC‐MS confirmed that the catalytic reactions of kraft lignin in the presence of peracetic acid produced major products including 2‐methoxy phenol, 2‐hydroxy benzaldehyde, 4‐hydroxy‐3,5‐dimethoxyphenyl ethanone. The encapsulated complexes exhibited improved reactivity compared to the corresponding neat complexes. Additionally, there was a greater improvement in TOF value for complexes upon IM‐immobilization as compared to SB‐immobilization. The improved salen, that is, [H4]salen, was beneficial to the enhancement of catalytic activity as compared to [H2]salen, as revealed by the high TOF values due to the incorporation of a modified coordination environment of the central cobalt cation by C=N hydrogenation. Actually, Co([H4]salen)/IM was proved to be most active. Lignin conversion and TOF were high over the neat cobalt complexes when using 100% H2O as the solvent, and the values were high over the corresponding encapsulated analogues when using 80% H2O + 20% CH3OH as the solvent. It can be found that encapsulation and hydrogenation of the complexes can improve the selectivity to 2‐methoxy phenol in the oxidation of kraft lignin. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2014,131, 40809.
Antibacterial activity against Escherichia coli of Cu‐BTC (MOF‐199) metal‐organic framework immobilized onto cellulosic fibers
Authors: Rodríguez Haendel S. , Hinestroza Juan P. , Ochoa‐Puentes Cristian , Sierra Cesar A. , Soto Carlos Y. 
Published: April 2014

ABSTRACTA strong antimicrobial activity against Escherichia coli of Cu‐BTC metal‐organic frameworks immobilized over cellulosic fibers is hereby reported. The in situ synthesis of Cu‐BTC metal‐organic frameworks, aka MOF‐199 or HKUST‐1, onto cellulosic substrates was carried out by exposing carboxymethylated cellulosic substrates to Cu(OAC)2, 1,3,5‐benzenetricarboxylic acid and triethylamine solutions following a very specific order. Using an in vitro model, in accordance to ASTM E2149‐13a, we observed that the cellulose‐MOF system was able to completely eliminate the growth of E. coli on agar plates and liquid cultures. The antibacterial activity of the comprising components of MOF‐199 and the cellulosic substrate was also evaluated and determined to be negligible. Since the method used to synthesize MOF‐199 crystals provides a strong bond between the crystals and the cellulosic substrates, the crystals not detach from the anionic cellulosic fibers allowing the modified textile to be washed and reused hence opening a new avenue to fabricate antibacterial clinical fabrics. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40815.
Overproduction of fatty acids in engineered Saccharomyces cerevisiae
Authors: Li Xiaowei , Guo Daoyi , Cheng Yongbo , Zhu Fayin , Deng Zixin , Liu Tiangang 
Published: April 2014

ABSTRACTThe long hydrocarbon fatty acyl chain is energy rich, making it an ideal precursor for liquid transportation fuels and high‐value oleo chemicals. As Saccharomyces cerevisiae has many advantages for industrial production compared to Escherichia coli. Here, we attempted to engineer Saccharomyces cerevisiae for overproduction of fatty acids. First, disruption of the beta‐oxidation pathway, elimination of the acyl‐CoA synthetases, overexpression of different thioesterases and acetyl‐CoA carboxylase ACC1, and engineering the supply of precursor acetyl‐CoA. The engineered strain XL122 produced more than 120 mg/L of fatty acids. In parallel, we inactivated ADH1, the dominant gene for ethanol production, to redirect the metabolic flux to fatty acids synthesis. The engineered strain DG005 produced about 140 mg/L fatty acids. Additionally, Acetyl‐CoA carboxylase was identified as a critical bottleneck of fatty acids synthesis in S. cerevisiae with a cell‐free system. However, overexpression of ACC1 has little effect on fatty acids biosynthesis. As it has been reported that phosphorylation of ACC1 may influent its activity, so phosphorylation sites of ACC1 were further identified. Although the regulatory mechanisms remain unclear, our results provide rationale for future studies to target this critical step. All these efforts, particularly the discovery of the limiting step are critical for developing a “cell factory” for the overproduction of fatty acids by using type I fatty acids synthase in yeast or other fungi. Biotechnol. Bioeng. 2014;111: 1841–1852. © 2014 Wiley Periodicals, Inc.
A comparative study of orthotropic and isotropic bone adaptation in the femur
Authors: Geraldes Diogo M. , Phillips Andrew T. M. 
Published: April 2014

SUMMARYFunctional adaptation of the femur has been studied extensively by embedding remodelling algorithms in finite element models, with bone commonly assumed to have isotropic material properties for computational efficiency. However, isotropy is insufficient in predicting the directionality of bone's observed microstructure. A novel iterative orthotropic 3D adaptation algorithm is proposed and applied to a finite element model of the whole femur. Bone was modelled as an optimised strain‐driven adaptive continuum with local orthotropic symmetry. Each element's material orientations were aligned with the local principal stress directions and their corresponding directional Young's moduli updated proportionally to the associated strain stimuli. The converged predicted density distributions for a coronal section of the whole femur were qualitatively and quantitatively compared with the results obtained by the commonly used isotropic approach to bone adaptation and with ex vivo imaging data. The orthotropic assumption was shown to improve the prediction of bone density distribution when compared with the more commonly used isotropic approach, whilst producing lower comparative mass, structurally optimised models. It was also shown that the orthotropic approach can provide additional directional information on the material properties distributions for the whole femur, an advantage over isotropic bone adaptation. Orthotropic bone models can help in improving research areas in biomechanics where local structure and mechanical properties are of key importance, such as fracture prediction and implant assessment. © 2014 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons, Ltd.
Modeling and simulation of the effects of cyclic loading on articular cartilage lesion formation
Authors: Wang Xiayi , Ayati Bruce P. , Brouillete Marc J. , Graham Jason M. , Ramakrishnan Prem S. , Martin James A. 
Published: April 2014

SUMMARYWe present a model of articular cartilage lesion formation to simulate the effects of cyclic loading. This model extends and modifies the reaction‐diffusion‐delay model by Graham et al., 2012 for the spread of a lesion formed though a single traumatic event. Our model represents ‘implicitly’ the effects of loading, meaning through a cyclic sink term in the equations for live cells.Our model forms the basis for in silico studies of cartilage damage relevant to questions in osteoarthritis, for example, that may not be easily answered through in vivo or in vitro studies.Computational results are presented that indicate the impact of differing levels of erythropoietin on articular cartilage lesion abatement. Copyright © 2014 John Wiley & Sons, Ltd.
Patient‐specific assessment of cardiovascular function by combination of clinical data and computational model with applications to patients undergoing Fontan operation
Authors: Liang Fuyou , Sughimoto Koichi , Matsuo Kozo , Liu Hao , Takagi Shu 
Published: April 2014

SUMMARYThe assessment of cardiovascular function is becoming increasingly important for the care of patients with single‐ventricle defects. However, most measurement methods available in the clinical setting cannot provide a separate measure of cardiac function and loading conditions. In the present study, a numerical method has been proposed to compensate for the limitations of clinical measurements. The main idea was to estimate the parameters of a cardiovascular model by fitting model simulations to patient‐specific clinical data via parameter optimization. Several strategies have been taken to establish a well‐posed parameter optimization problem, including clinical data‐matched model development, parameter selection based on an extensive sensitivity analysis, and proper choice of parameter optimization algorithm. The numerical experiments confirmed the ability of the proposed parameter optimization method to uniquely determine the model parameters given an arbitrary set of clinical data. The method was further tested in four patients undergoing the Fontan operation. Obtained results revealed a prevalence of ventricular abnormalities in the patient cohort and at the same time demonstrated the presence of marked inter‐patient differences and preoperative to postoperative changes in cardiovascular function. Because the method allows a quick assessment and makes use of clinical data available in clinical practice, its clinical application is promising. Copyright © 2014 John Wiley & Sons, Ltd.
Bdnf DNA methylation modifications in the hippocampus and amygdala of male and female rats exposed to different caregiving environments outside the homecage
Authors: Roth Tania L. , Matt Stephanie , Chen Kenneth , Blaze Jennifer 
Published: April 2014

ABSTRACTWe have previously shown in infant rats that brief and repeated experiences with a stressed dam outside the homecage (maltreatment) alters methylation of DNA associated with the brain‐derived neurotrophic factor (bdnf) gene within the developing and adult prefrontal cortex. BDNF is a key mediator of activity‐dependent processes that have a profound influence on neural development and plasticity. Here we examined whether maltreatment also alters bdnf DNA methylation in two additional regions known to be prominently affected by diverse forms of early life adversity in humans‐ the hippocampus and amygdala. We found significant bdnf DNA methylation modifications present within the adult hippocampus (dorsal and ventral) and amygdala (central/basolateral complex). We observed that the nature of change differed between sexes, gene locus (bdnf I vs. IV), and brain region. Furthermore, a manipulation that did not produce any obvious behavior difference in infants (brief and repeated experiences with a nurturing foster dam) also had long‐term effects on methylation. These data provide further empirical support of DNA methylation modifications as biological consequences of caregiving environments. © 2014 Wiley Periodicals, Inc. Dev Psychobiol 56: 1755–1763, 2014.
Bird and mammal species composition in distinct geographic regions and their relationships with environmental factors across multiple spatial scales
Authors: Kent Rafi , Bar‐Massada Avi , Carmel Yohay 
Published: April 2014

AbstractGlobal patters of species distributions and their underlying mechanisms are a major question in ecology, and the need for multi‐scale analyses has been recognized. Previous studies recognized climate, topography, habitat heterogeneity and disturbance as important variables affecting such patterns. Here we report on analyses of species composition – environment relationships among different taxonomic groups in two continents, and the components of such relationships, in the contiguous USA and Australia. We used partial Canonical Correspondence Analysis of occurrence records of mammals and breeding birds from the Global Biodiversity Information Facility, to quantify relationships between species composition and environmental variables in remote geographic regions at multiple spatial scales, with extents ranging from 105 to 107 km2 and sampling grids from 10 to 10,000 km2. We evaluated the concept that two elements contribute to the impact of environmental variables on composition: the strength of species' affinity to an environmental variable, and the amount of variance in the variable. To disentangle these two elements, we analyzed correlations between resulting trends and the amount of variance contained in different environmental variables to isolate the mechanisms behind the observed relationships. We found that climate and land use‐land cover are responsible for most explained variance in species composition, regardless of scale, taxonomic group and geographic region. However, the amount of variance in species composition attributed to land use / land cover (LULC) was closely related to the amount of intrinsic variability in LULC in the USA, but not in Australia, while the effect of climate on species composition was negatively correlated to the variability found in the climatic variables. The low variance in climate, compared to LULC, suggests that species in both taxonomic groups have strong affinity to climate, thus it has a strong effect on species distribution and community composition, while the opposite is true for LULC.
Current Control for SPMSM in Field‐Weakening Region Based on Final‐State Control
Authors: Miyajima Takayuki , Fujimoto Hiroshi , Fujitsuna Masami 
Published: April 2014

SUMMARYSPMSMs (surface permanent magnet synchronous motors) are employed for many industrial applications. SPMSM drive systems should realize a quick torque response and have a wide operating range. For quick current response in the field‐weakening region, a new current control based on final‐state control (FSC) is proposed in this study. FSC settles the state variables in a final state from an initial state with feedforward input during a finite time. In addition, the current response under voltage limit is analyzed by the voltage limit circle of the SPMSM with a transient term.
Evaluation of Electronic States of Polymer Surface Using Photoelectron Spectroscopy in Air
Authors: Hashimoto Yuichi 
Published: April 2014

SUMMARYWe investigated shallow surface states relevant to electrification between polymer film and metal ring by photoelectron spectroscopy in air. It was found that the charge transferred from the metal ring to the polyethylene terephthalate (PET) film depended on the work function of the metal ring and the distribution of the density of states in the PET film. It was also found that electrification between the polymer and an aluminum ring was related to the chemical structure, i.e., pendant groups in the polymer.
A CTI System to Support the Seamless Workplace and Its Implementation
Authors: Watanabe Toru , Koizumi Hisao 
Published: April 2014

SUMMARYThis paper proposes a CTI client/server coordination system exclusively for use with a smart phone. The system makes use of a CTI client, performing combined functions of a SIP phone and a Web browser. The proposed CTI client/server coordination system comprises SIP servers and Web servers, both of which are installed in enterprises, and CTI clients that run on smart phones in a mobile environment. Furthermore, the CTI clients perform the function of SIP phone by communicating with SIP servers. In addition, CTI clients can display telephone directories and logging of phone calls stored in Web servers. They can display screens of ordinary Web browsers. Here, one might switch between a SIP phone function and a Web communication screen with merely a single touch of the tab key. Consequently, smart phones in the mobile environment make it possible to conduct telephone meetings while browsing with a Web screen.
An advanced numerical model of elastomeric seismic isolation bearings
Authors: Kumar Manish , Whittaker Andrew S. , Constantinou Michael C. 
Published: April 2014

SUMMARYThe nuclear accident at Fukushima Daiichi in March 2011 has led the nuclear community to consider seismic isolation for new large light water and small modular reactors to withstand the effects of beyond design basis loadings, including extreme earthquakes. The United States Nuclear Regulatory Commission is sponsoring a research project that will quantify the response of low damping rubber (LDR) and lead rubber (LR) bearings under loadings associated with extreme earthquakes. Under design basis loadings, the response of an elastomeric bearing is not expected to deviate from well‐established numerical models, and bearings are not expected to experience net tension. However, under extended or beyond design basis shaking, elastomer shear strains may exceed 300% in regions of high seismic hazard, bearings may experience net tension, the compression and tension stiffness will be affected by isolator lateral displacement, and the properties of the lead core in LR bearings will degrade in the short‐term because of substantial energy dissipation.New mathematical models of LDR and LR bearings are presented for the analysis of base isolated structures under design and beyond design basis shaking, explicitly considering both the effects of lateral displacement and cyclic vertical and horizontal loading. These mathematical models extend the available formulations in shear and compression. Phenomenological models are presented to describe the behavior of elastomeric isolation bearings in tension, including the cavitation and post‐cavitation behavior. The elastic mechanical properties make use of the two‐spring model. Strength degradation of LR bearing under cyclic shear loading due to heating of lead core is incorporated. The bilinear area reduction method is used to include variation of critical buckling load capacity with lateral displacement. The numerical models are coded in OpenSees, and the results of numerical analysis are compared with test data. The effect of different parameters on the response is investigated through a series of analyses. Copyright © 2014 John Wiley & Sons, Ltd.