bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fracture phenomena in micro‐ and nano‐layered polycarbonate/poly(vinylidene fluoride‐co‐hexafluoropropylene) films under electric field for high energy density capacitors
Authors: Zhou Zheng , Mackey Matt , Yin Kezhen , Zhu Lei , Schuele Donald , Flandin Lionel , Baer Eric 
Published: October 2013

ABSTRACTThe long‐term dielectric lifetime properties of multilayered polycarbonate/poly(vinylidene fluoride‐co‐hexafluoropropylene) [PC/P(VDF‐HFP)] films were measured as a function of the layer thickness. An optimum layer thickness of 160 nm was determined with the longest dielectric lifetime. The morphology of the damaged sites after dielectric breakdown was examined using scanning electron microscope. Acoustic emission detection system was coupled with the dielectric setup to correlate fracture events and dielectric breakdown to thereby elucidate the mechanisms of the enhancements in dielectric lifetime properties. Two types of acoustic signals were always observed during the breakdown process for multilayered films. The high‐amplitude signals were attributed to the formation of breakdown pinholes caused by the primary discharge from top to bottom electrode. The subsequent low‐amplitude signals were attributed to internal discharges that could further damage the film. The total number of acoustic hits, in particular, low‐amplitude hits, increased with decreasing layer thickness, indicating more internal discharges occurred along the layered interface. It was concluded that the breakdown event initiated at a defect initiated “hotspot” formed because of internal pressure buildup. The film was punctured when the pressure buildup inside the film overcame the mechanical strength of the film. More number of PC layers and layer interfaces were desirable to slow down and divert the damage propagation through the film thickness direction. The crazes in P(VDF‐HFP) can, however, easily propagate across PC layers with less than 160 nm layer thickness. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39877.
In situ preparation of cyclohexanone formaldehyde resin/layered silicate nanocomposites
Authors: Kızılcan Nilgün , Mermutlu Mehmet 
Published: October 2013

ABSTRACTIn this study, in situ modified cyclohexanone formaldehyde resin (CFR) was prepared from clay (montmorillonite) and polydimethylsiloxane with diamine chain ends [α,ω‐diamine poly(dimethyl siloxane) (DA.PDMS)] in the presence of a base catalyst. Different clay contents (from 0.5 to 3 wt %) were used to produce clay‐modified nanocomposite ketonic resins [layered clay (LC)–CFR] and clay‐ and DA.PDMS‐modified nanocomposite ketonic resins (DA.PDMS–LC–CFR). The polymeric nanocomposite material prepared by this method was directly synthesized in one step. These nanocomposites were confirmed from X‐ray diffraction to have a layered structure with a folded or penetrated CFR, and they were further characterized via Fourier transform infrared spectroscopy–attenuated total reflectance and NMR spectroscopy. The thermal properties of all of the resins were studied with differential scanning calorimetry and thermogravimetric analysis. All of the resins showed higher thermal stability than their precursor CFR resin. The obtained samples were also characterized morphologically by scanning electron microscopy. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39918.
Influence of various reaction media on the thermal and rheological properties of poly(acrylamide‐co‐N‐hexadecylacrylamide)
Authors: Hassanajili Shadi , Abdollahi Elaheh 
Published: October 2013

ABSTRACTA hydrophobically modified polyacrylamide (PAM) was synthesized by the copolymerization of acrylamide (Am) and N‐hexadecylacrylamide (hAm) through solution copolymerization in a polar organic solvent. Polymer synthesis was performed in three nonaqueous media, including dimethyl sulfoxide (DMSO), a mixture of DMSO and an anionic surfactant such as sodium dodecyl sulfate, and a mixture of DMSO and an acidic surfactant such as dodecyl benzene sulfonic acid. The obtained copolymer, poly(acrylamide‐co‐N‐hexadecylacrylamide) [poly(Am‐co‐hAm)], was characterized by 1H‐NMR. The physical properties of poly(Am‐co‐hAm)s synthesized in different media were compared with those of PAM and with each other by viscosity measurement, X‐ray diffraction, thermogravimetric analysis, and differential scanning calorimetry. We investigated the ways in which the polymerization medium affected the hydrophobic distribution within the resulting copolymer structure. This aspect, in turn, should have altered the solution properties and the microstructure of the copolymer. For this purpose, we studied the viscometric behavior in diluted solutions, the thermal behavior and thermal stability of the copolymers, and finally, the crystalline structure of the copolymers. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39939.
Plasticizer migration in bloodmeal‐based thermoplastics
Authors: Bier James Michael , Verbeek Casparus Johannes Reinhard , Lay Mark Christopher 
Published: October 2013

ABSTRACTTri‐ethylene glycol (TEG) is an effective plasticizer for many protein‐based thermoplastics because of its low volatility, however, partial miscibility with the protein matrix may still lead to some phase separation. Spatial variation of TEG concentration in bloodmeal‐based thermoplastics as a result of processing was investigated using synchrotron‐based FT‐IR micro‐spectroscopy. Although TEG forms strong hydrogen bonding with proteins, for the protein to fold into β‐sheets bound plasticizer must be released. TEG can then migrate, pooling into localized areas, rich in plasticizer. Further heating causes further migration towards the edge of plasticized bloodmeal particles where the TEG may evaporate. Thermo‐gravimetric analysis confirmed that loss of TEG by evaporation may occur at 120°C, given enough time for diffusion. Efficient mixing combined with a short residence time at elevated temperature mean significant plasticizer loss is unlikely during processing. However, it does limit long‐term use at elevated temperatures. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39969.
The Public Roles of the Private Sector in Asia: The Emerging Research Agenda
Authors: Florini Ann 
Published: October 2013

AbstractIt is no longer possible to understand public policy without focusing intensively on the public roles of the business sector. The world is awash in experimental private governance, from corporate codes of conduct, to demands for disclosure of private sector environmental and social impacts, to ‘social enterprises’ that aim to save the world the profitable way. Such experiments are emerging within Asia, changing the terms of the social licence to operate as society becomes more adept at making demands for good corporate citizenship and as the natural resource crisis begins to hit home. And as Asian corporations go global, they encounter new standards for social responsibility. Yet far too little is known about the status of these trends in Asia and how the debates over corporate responsibility, developed in a Western context, might translate given the very different relationships among government, business and society in the region. This article explores practice and theory to uncover what is already known and how to frame further research. It concludes by laying out a research agenda to analyse how the public roles of the private sector in Asia are evolving, and why they matter.
Food Security in Asia and the Pacific: The Rapidly Changing Role of Rice
Authors: Timmer C. Peter 
Published: October 2013

AbstractFood security in Asia and the Pacific presents a frustrating paradox. At one level, huge progress has been made in the past half century in bringing most of the population out of poverty and hunger. Measured by the key determinants of food security—improved availability, access, utilisation and stability—food security has never been at higher levels. Large pockets of food‐insecure populations remain in the region, especially in South Asia, and continued efforts to reach these households are necessary. At the same time, food security strategies in Asia are mostly in disarray. Most countries are protecting their rice farmers and providing high price supports, but high rice prices hurt the vast majority of the poor. Continued efforts to stabilise rice prices are understandable politically and desirable economically, but much more open trade regimes for rice will help food security throughout the region.
Light Emission in Water‐Containing Cocrystals: the Influence of Water Molecules on the Fluorescence Properties of a Schiff‐Base Molecule
Authors: Zhou Feng , Tan Pengli , Ma Yong , Li Youyong , Li Najun , Li Hua , Wang Lihua , Gu Hongwei , Xu Qingfeng , Lu Jianmei 
Published: October 2013

AbstractIn the presence or absence of water, a Schiff‐base compound, 4‐amino‐3‐(2‐(2‐hydroxybenzylidene)hydrazinyl)‐1H‐1,2,4‐triazole‐5(4H)‐thione (HATT), forms different crystalline states (HATT, HATT⋅2 H2O, and a lamellar structure, m‐HATT⋅n H2O), which show different luminescence emission properties. Herein, we investigate the emission of HATT and the role of water molecules. A water molecule, which acts as both a hydrogen‐bond acceptor and ‐donor, enlarges the distance between adjacent HATT molecules and hinders non‐radiative decay pathways.
IMC–PID Design: Analytical Optimization for Performance/Robustness Tradeoff Tuning for Servo/Regulation Mode
Authors: Jin Qi‐bing , Liu Qie , Wang Qi , Li Si‐nian , Wang Zhu 
Published: October 2013

ABSTRACTThis paper addresses the analytical design of a one‐degree‐of‐freedom (1‐DoF) robust proportional–integral–derivative (PID) controller for the servo/regulation mode in line with the enhanced internal model control (IMC) principle based on a first order plus dead time (FOPDT) model. The proposed enhanced IMC–PID can provide acceptable performance both for set‐point tracking and for load disturbance rejection. The design procedure is formulated as a constrained optimization problem, in which the robustness of the system is adequately considered. Therefore, the resulting PID controller gives optimal performance with an exact selected robustness degree. Illustrative examples are given to show the effectiveness and merits of the analytical tuning rules for a wide range of plants.
Phenol removal from refinery wastewater by mutant recombinant horseradish peroxidase
Authors: Asad Sedigheh , Dabirmanesh Bahareh , Khajeh Khosro 
Published: October 2013

AbstractApplication of mutated recombinant horseradish peroxidase (HRP) for phenol removal from refinery effluents is reported. Recombinant HRP produced in Escherichia coli suffers from the disadvantage of lacking glycosylation, which affects its catalytic efficiency and stability toward inactivating parameters such as increased temperature and enhanced amounts of hydrogen peroxide. In the present study, the previously reported variant (in which Asn268 was substituted with Asp, N268D) with improved stability characteristics and catalytic efficiency was used to remove phenol from a petroleum refinery effluent. The presence and removal of phenol was studied by high‐performance liquid chromatography; the precipitated oxidized phenol was also observed and removed from the sample by centrifugation. Results showed that the N268D variant can remove 61%, 67%, and 81% of phenol from effluent in 1, 2, and 16 H, respectively. By exploiting the N268D mutant, removal of 50% phenol could be achieved in 42 Min, which was more than 22 times less than the treatment time required by native recombinant enzyme.
Optimal durations of single exposures to a frequency‐modulated magnetic field immediately after bisection in planarian predict final growth values
Authors: Tessaro Lucas W.E. , Persinger Michael A. 
Published: October 2013

AbstractPlanarian (Dugesia tigrinia) were exposed to a frequency‐modulated (“Thomas”), patterned electromagnetic field (EMF) immediately following transection through the pharynx. Subjects were exposed from 15 min to 3 h as well as single versus repeated exposures. Results from multiple experiments indicated that those planaria exposed from 45 to 90 min regenerated at significantly higher rates than those exposed less than 45 min. In addition, the study revealed that exposures greater than 45 min were not significantly different beyond this inflection point. We suggest that this particular pattern of EMF is capable of inducing biochemical pathways associated with cell proliferation, in particular the p38‐MAPK and hsp70 pathways. Bioelectromagnetics 34:613–617, 2013. © 2013 Wiley Periodicals, Inc.
The interaction between cepharanthine and two serum albumins: multiple spectroscopic and chemometric investigations
Authors: Cheng Zhengjun , Liu Rong , Jiang Xiaohui , Xu Qianyong 
Published: October 2013

ABSTRACTThe binding modes of cepharanthine (CEPT) with bovine serum albumin (BSA) and human serum albumin (HSA) have been established by reproducing physiological conditions, which is very important to understand the pharmacokinetics and toxicity of CEPT. These spectral data were further analyzed by the multivariate curve resolution‐alternating least squares method. Moreover, the concentration profiles and pure spectra of three species (BSA/HSA, CEPT and CEPT–BSA/HSA) and the apparent equilibrium constants Kapp were evaluated. The experimental results showed that CEPT could quench the fluorescence intensity of BSA/HSA by a combined quenching (static and dynamic) procedure. The binding constant (K), the thermodynamic parameters (ΔG, ΔH and ΔS) and binding subdomain were measured, and indicated that CEPT could spontaneously bind to BSA/HSA on subdomain IIA through the hydrophobic interactions. The effect of CEPT on the secondary structure of proteins has been analyzed by circular dichroism, 3D fluorescence and Fourier transform infrared spectra. The binding distance between CEPT and tryptophan of BSA/HSA was 2.305/1.749 nm, which is based on the Förster resonance energy transfer theory. Copyright © 2013 John Wiley & Sons, Ltd.
A new quaternary photoluminescence enhancement system of Eu−N‐(o‐vanillin)‐1,8‐diaminonaphthalene−1,10‐phenanthroline−Zn and its application in determining trace amounts of europium and zinc
Authors: Zhou Yunshan , Ahmad Waqar , An Yugang , Zhang Lijuan , Zheng Xiaorui 
Published: October 2013

ABSTRACTA new sensitive quaternary photoluminescence enhancement system has been successfully developed to determine trace amounts of Eu3+and Zn2+. The photoluminescence intensity of Eu − N‐(o‐vanilin)‐1,8‐diaminonaphthalene systems was greatly increased by the addition of specific concentrations of 1, 10‐phenanthroline and Zn2+. The excitation and emission wavelengths were 274 and 617 nm, respectively. Under optimal system conditions, the photoluminescence intensity showed a linear response toward Eu3+in the range of 5.0 × 10–6 ~ 2.0 × 10–5 M with a limit of detection (= 2.2 × 10–9 M) and the photoluminescence intensity of the system decreased linearly by increasing the Zn2+concentration in the range of 5.0 × 10–8 ~ 1.0 × 10–6 M with a limit of detection (= 8.8 × 10–11 M). This system was successfully applied for the determination of trace amounts of Eu3+in a high purity La2O3matrix and in the synthetic rare earth oxide mixture, and of Zn2+in a high purity Mg(NO3)2 · 6H2O matrix and in synthetic coexisting ionic matrixes. The energy transfer mechanism, photoluminescence enhancement of the system and interference of other lanthanide ions and common coexisting ions were also studied in detail. Copyright © 2013 John Wiley & Sons, Ltd.
Applications of cell‐free protein synthesis in synthetic biology: Interfacing bio‐machinery with synthetic environments
Authors: Lee Kyung‐Ho , Kim Dong‐Myung 
Published: October 2013

AbstractSynthetic biology is built on the synthesis, engineering, and assembly of biological parts. Proteins are the first components considered for the construction of systems with designed biological functions because proteins carry out most of the biological functions and chemical reactions inside cells. Protein synthesis is considered to comprise the most basic levels of the hierarchical structure of synthetic biology. Cell‐free protein synthesis has emerged as a powerful technology that can potentially transform the concept of bioprocesses. With the ability to harness the synthetic power of biology without many of the constraints of cell‐based systems, cell‐free protein synthesis enables the rapid creation of protein molecules from diverse sources of genetic information. Cell‐free protein synthesis is virtually free from the intrinsic constraints of cell‐based methods and offers greater flexibility in system design and manipulability of biological synthetic machinery. Among its potential applications, cell‐free protein synthesis can be combined with various man‐made devices for rapid functional analysis of genomic sequences. This review covers recent efforts to integrate cell‐free protein synthesis with various reaction devices and analytical platforms.
Spectroscopic studies of the unfolding of a multimeric protein α‐crystallin
Authors: Chowdhury Aritra , Choudhury Aparajita , Banerjee Victor , Banerjee Rajat , Das K. P. 
Published: October 2013

ABSTRACTα‐Crystallin is a multimeric eye lens protein having molecular chaperone‐like function which is crucial for lens transparency. The stability and unfolding‐refolding properties of α‐crystallin plays important roles for its function. We undertook a multi probe based fluorescence spectroscopic approach to explore the changes in the various levels of organization of this protein at different urea concentration. Steady state fluorescence studies reveal that at 0.6M urea a compact structural intermediate is formed which has a native‐like secondary structure with enhanced surface exposure of hydrophobic groups. At 2.8M urea the tertiary interactions are largely collapsed with partial collapse of secondary and quaternary structure. The surface solvation probed by picosecond time resolved fluorescence of acrylodan labeled α‐crystallin revealed dry native‐like core of α‐crystallin at 0.6M urea compared to enhanced water penetration at 2.8M urea and extensive solvation at 6M urea. Activation energy for the subunit exchange decreased by 22 kJ mol−1 on changing urea concentration from 0 to 0.6M compared with over 75 kJ mol−1 on changing urea concentration from 0 to 2.8M. Light scattering and analytical ultracentrifugation techniques were used to determine size and oligomerization of the unfolding intermediates. The data indicated swelling but no oligomer breakdown at 0.6M urea. At 2.8M urea the oligomeric size is considerably reduced and a monomer is produced at 6M urea. The data clearly reveals that structural breakdown of α‐crystallin does not follow hierarchical sequence as tertiary structure dissolution takes place before complete oligomeric dissociation. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 549–560, 2014.
Antimicrobial peptides against Pseudomonas syringae pv. actinidiae and Erwinia amylovora: Chemical synthesis, secondary structure, efficacy, and mechanistic investigations
Authors: Cameron Alan , Zoysa Gayan Heruka De , Sarojini Vijayalekshmi 
Published: October 2013

ABSTRACTWe report on structurally modified dodecapeptide amides (KYKLFKKILKFL‐NH2) and two analogs of a hexapeptide amide (WRWYCR‐NH2) with antibacterial activity against the Gram negative pathogens Pseudomonas syringae pv. actinidiae (Psa) and Erwinia amylovora (Ea). Dodecapeptide minimal inhibitory concentrations (MICs) ranged from 3.2 to 15.4 µM, with the unmodified peptide being the most potent against both pathogens. The unmodified dodecapeptide also had 32–58% α‐helicity in membrane mimetic environments (50% v/v trifluoroethanol and 30 mM SDS micelles). Structural modifications which included branching, acylation, and conjugation with 5‐nitro‐2‐furaldehyde (NFA) proved detrimental to both antimicrobial activity and α‐helicity. Scanning electron microscopy (SEM) revealed distinct morphological changes to bacterial cells treated with the different peptides, leading to blistering of the membrane and cell lysis. MICs of the hexapeptide amide were 3.9–7.7 µM against both pathogens. The hexapeptide acid did not show anti‐bacterial activity against either pathogen. However, the NFA conjugated hexapeptide acid was more active than the parent peptide or NFA alone with MICs of 1.6–3.2 µM against the pathogens. SEM analysis revealed shriveling and collapse of bacterial cells treated with the hexapeptide, whereas shortening and compactness on exposure to streptomycin. A colorimetric assay demonstrated that the dodecapeptides were likely to act by targeting the bacterial membrane, whereas the hexapeptides, streptomycin, and NFA were not, thereby supporting the morphological changes observed during SEM. To the best of our knowledge, this appears to be the first report of antimicrobial peptide activity against Psa, a pathogen that is currently devastating the kiwifruit industry internationally. © 2013 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 102: 88–96, 2014.
Novel thermo‐responsive fucose binding ligands for glycoprotein purification by affinity precipitation
Authors: Arnold Lindsay , Chen Rachel 
Published: October 2013

ABSTRACTNovel thermo‐responsive affinity sugar binders were developed by fusing a bacterial fucose lectin with a thermo‐responsive polypeptide. These designer affinity ligand fusions were produced using an Escherichia coli system capable of extracellular secretion of recombinant proteins and were isolated with a high recovery yield (95%) directly from growth medium by Inverse Temperature Cycling (ITC). With horse radish peroxidase (HRP) as a model protein, we demonstrate here that the designer thermo‐responsive ligands are capable of interacting with glycans on a glycoprotein, a property that was used to develop a novel affinity precipitation method for glycoprotein purification. The method, requiring only simple process steps, affords full recovery of a target glycoprotein, and is effective at a target glycoprotein concentration as low as 1.4 pM in the presence of large amounts of contaminants. By developing other sugar binders in the similar fashion, the method should be highly useful for glycoprotein purification and detection. Biotechnol. Bioeng. 2014;111: 413–417. © 2013 Wiley Periodicals, Inc.
Fluorogen‐activating‐proteins as universal affinity biosensors for immunodetection
Authors: Gallo Eugenio , Vasilev Kalin V. , Jarvik Jonathan 
Published: October 2013

ABSTRACTFluorogen‐activating‐proteins (FAPs) are a novel platform of fluorescence biosensors utilized for protein discovery. The technology currently demands molecular manipulation methods that limit its application and adaptability. Here, we highlight an alternative approach based on universal affinity reagents for protein detection. The affinity reagents were engineered as bi‐partite fusion proteins, where the specificity moiety is derived from IgG‐binding proteins—Protein A or Protein G—and the signaling element is a FAP. In this manner, primary antibodies provide the antigenic selectivity against a desired protein in biological samples, while FAP affinity reagents target the constant region (Fc) of antibodies and provide the biosensor component of detection. Fluorescence results using various techniques indicate minimal background and high target specificity for exogenous and endogenous proteins in mammalian cells. Additionally, FAP‐based affinity reagents provide enhanced properties of detection previously absent using conventional affinity systems. Distinct features explored in this report include: (1) unfixed signal wavelengths (excitation and emission) determined by the particular fluorogen chosen, (2) real‐time user controlled fluorescence on‐set and off‐set, (3) signal wavelength substitution while performing live analysis, and (4) enhanced resistance to photobleaching. Biotechnol. Bioeng. 2014;111: 475–484. © 2013 Wiley Periodicals, Inc.