bluuebunny/crossref_metadata_2025 huggingface dataset:
Synergy of energy resources of copper pyrometallurgy in RTB Bor-Serbia
Authors: Ćirković Milorad , Trujić Vlastimir , Bugarin Mile
Published: May 2015

Copper production is a significant consumer of energy, consisting of almost all fossil fuels, and also including electricity. This work presents a comparison of the specific energy consumption of several metallurgical copper producers in the world, with the installed different technological processes, in comparison to the production of copper in RTB Bor (Serbia). An important place is dedicated to the quantitative participation of energy fuels in the production of copper. In addition to this, an analysis of cost structure for energy fuels was shown in the production process of copper. This work particularly emphasizes the aspect of use the secondary (waste) heat energy as a prerequisite to improve the energy efficiency and economy of pyrometallurgical copper production. Using the waste heat of pyrometallurgical process, the protection of working and life environment is improved Selection and development of new metallurgical processes in order to achieve the best economic effects is achieved selecting the optimum technology, on one side, and selection of energy system with the best performances with the full utilization the secondary heat energy of the process. Concretization of this aspect also relates to the modernization of the Copper Smelter in RTB Bor installing the new technology for smelting of copper concentrates.
Influence of an accumulative roll bonding (ARB) process on the properties of AA5083 Al-Mg alloy sheets
Authors: Alil Ana , Popović Miljana , Radetić Tamara , Romhanji Endre
Published: May 2015

In this study, fully annealed AA5083 type alloy sheets with 1 mm in thickness were processed by accumulative roll bonding (ARB) at room temperature, up to 6 ARB cycles. It was found that microstructure was refined and mechanical properties were significantly improved with ARB processing. The maximum achieved values of hardness and tensile strength were two and three times greater than that of the initial material, respectively. This was attributed to the intensive strain hardening and grain size refinement which occurred during ARB deformation. However, the uniform elongation values were decreased by increasing the number of ARB cycles, and early fracture was registered. SEM fractography of fractured surfaces after tensile tests revealed a typical ductile fracture of ARB processed specimens, which was changed with ARB deformation. It was observed that ductile area on the fractured surfaces and the amount of necking, which occured before fracture, were decreased with increasing the number of ARB cycles.
Doctor Satisfaction and the Effects on Quality – Discussion
Authors: Firth-Cozens Jenny
Published: May 2015

This paper considers the question posed by Casalino and Crosson asking whether we should care about doctors’ levels of satisfaction.  It focuses initially on the evidence that satisfaction is a part of an individual’s emotional state which in turn allows us to offer studies showing that doctors perform less well when they are stressed.  It goes on to consider a large-scale survey showing a direct relationship between the satisfaction levels of healthcare staff and a variety of quality outcomes and focuses in particular on the concept of staff engagement in this regard.  Finally, it considers the role of management and context on the satisfaction and mental health of healthcare staff in general.  It concludes that, yes, we should care about doctors’ levels of satisfaction.
Alienation and Stress among Doctors: Dilemmas and Possible Solutions
Authors: Light Donald W.
Published: May 2015

Studies of alienation, stress, burnout, and dissatisfaction among doctors are plagued by unclear and varied definition of these terms. Many are small, local, and short, which limit insights. How much they harm patients is usually not studied but may be slight. A focus on patient evaluations, though resented, has led to defining quality standards that did not exist when autonomy reigned. But using consumer-oriented competition can have pernicious effects. Pharmaceutical influences are undermining trust and professionalism. But non-profit models of shared, collaborative initiatives increase morale and clinical quality as well.
Guest Editor's Introduction
Authors: Bringedal Berit
Published: May 2015

The paper provides an introduction to the special issue, as well as an overview of the collection of papers.
Physician Dissatisfaction in the United States: An Examination
Authors: Crosson Francis J. , Casalino Lawrence P.
Published: May 2015

This paper addresses several root causes of dissatisfaction with medical practice among American physicians, and suggests that some, but not all, are potentially remediable. Fixed assumptions about the nature of medical practice in the United States, developed over several decades, appear to be eroding. At the same time, increasing demands on physician time, especially involving low value documentation and administrative tasks are interfering with the physician-patient interaction. In addition, physician practice structure and payment methodologies are beginning to change in the United States leading to a sense of practice instability among physicians. Recent research conducted by the American Medical Association and the RAND Corporation has provided new qualitative and quantitative information about the impact of these trends on physician practices. An evaluation of these research findings indicates that some improvements in physician satisfaction are possible.    Keywords: physician professionalism, practice satisfaction, electronic health records, health care reform in the U.S.
Physicians' Psychosocial Work Conditions and Quality of Care: A Literature Review
Authors: Angerer Peter , Weigl Matthias
Published: May 2015

Background: Physician jobs are associated with adverse psychosocial work conditions. We summarize research on the relationship of physicians' psychosocial work conditions and quality of care. Method: A systematic literature search was conducted in MEDLINE and PsycINFO. All studies were classified into three categories of care quality outcomes: Associations between physicians' psychosocial work conditions and (1) the physician-patient-relationship, or (2) the care process and outcomes, or (3) medical errors were examined. Results: 12 publications met the inclusion criteria. Most studies relied on observational cross-sectional and controlled intervention designs. All studies provide at least partial support for physicians’ psychosocial work conditions being related to quality of care. Conclusions: This review found preliminary evidence that detrimental physicians’ psychosocial work conditions adversely influence patient care quality. Future research needs to apply strong designs to disentangle the indirect and direct effects of adverse psychosocial work conditions on physicians as well as on quality of care.

Keywords: psychosocial work conditions, physicians, quality of care, physician-patient-relationship, hospital, errors, review, work stress, clinicians
Healthy Doctors – Sick Medicine
Authors: Aasland Olaf Gjerløw
Published: May 2015

Doctors are among the healthiest segments of the population in western countries. Nevertheless, they complain strongly of stress and burnout. Their own explanation is deprofessionalisation: The honourable art of doctoring has been replaced by standardised interventions and production lines; professional autonomy has withered. This view is shared by many medical sociologists who have identified a “golden age of medicine,” or “golden age of doctoring,” starting after World War II and declining around 1970. This article looks at some of the central sociological literature on deprofessionalisation, particularly in a perspective of countervailing powers. It also looks into another rise-and-fall model, proposed by the medical profession itself, where the fall in professional power was generated by the notion that there are no more white spots to explore on the map of medicine. Contemporary doctoring is a case of cognitive dissonance, where the traditional doctor role seems incompatible with modern health care.

Keywords: deprofessionalisation, professional autonomy, cognitive dissonance, golden age of doctoring
Redox‐controlled preservation of organic matter during “OAE 3” within the Western Interior Seaway
Authors: Tessin Allyson , Hendy Ingrid , Sheldon Nathan , Sageman Bradley
Published: May 2015

During the Cretaceous, widespread black shale deposition occurred during a series of Oceanic Anoxic Events (OAEs). Multiple processes are known to control the deposition of marine black shales, including changes in primary productivity, organic matter preservation, and dilution. OAEs offer an opportunity to evaluate the relative roles of these forcing factors. The youngest of these events—the Coniacian to Santonian OAE 3—resulted in a prolonged organic carbon burial event in shallow and restricted marine environments including the Western Interior Seaway. New high‐resolution isotope, organic, and trace metal records from the latest Turonian to early Santonian Niobrara Formation are used to characterize the amount and composition of organic matter preserved, as well as the geochemical conditions under which it accumulated. Redox sensitive metals (Mo, Mn, and Re) indicate a gradual drawdown of oxygen leading into the abrupt onset of organic carbon‐rich (up to 8%) deposition. High Hydrogen Indices (HI) and organic carbon to total nitrogen ratios (C:N) demonstrate that the elemental composition of preserved marine organic matter is distinct under different redox conditions. Local changes in δ13C indicate that redox‐controlled early diagenesis can also significantly alter δ13Corg records. These results demonstrate that the development of anoxia is of primary importance in triggering the prolonged carbon burial in the Niobrara Formation. Sea level reconstructions, δ18O results, and Mo/total organic carbon ratios suggest that stratification and enhanced bottom water restriction caused the drawdown of bottom water oxygen. Increased nutrients from benthic regeneration and/or continental runoff may have sustained primary productivity.
Microbubble transport in water‐saturated porous media
Authors: Ma Y. , Kong X.‐Z. , Scheuermann A. , Galindo‐Torres S. A. , Bringemeier D. , Li L.
Published: May 2015

Laboratory experiments were conducted to investigate flow of discrete microbubbles through a water‐saturated porous medium. During the experiments, bubbles, released from a diffuser, moved upward through a quasi‐2‐D flume filled with transparent water‐based gelbeads and formed a distinct plume that could be well registered by a calibrated camera. Outflowing bubbles were collected on the top of the flume using volumetric burettes for flux measurements. We quantified the scaling behaviors between the gas (bubble) release rates and various characteristic parameters of the bubble plume, including plume tip velocity, plume width, and breakthrough time of the plume front. The experiments also revealed circulations of ambient pore water induced by the bubble flow. Based on a simple momentum exchange model, we showed that the relationship between the mean pore water velocity and gas release rate is consistent with the scaling solution for the bubble plume. These findings have important implications for studies of natural gas emission and air sparging, as well as fundamental research on bubble transport in porous media.
Simulation of energetic particle precipitation effects during the 2003–2004 Arctic winter
Authors: Randall C. E. , Harvey V. L. , Holt L. A. , Marsh D. R. , Kinnison D. , Funke B. , Bernath P. F.
Published: May 2015

Energetic particle precipitation (EPP) during the 2003–2004 Arctic winter led to the production and subsequent transport of reactive odd nitrogen (NOx = NO + NO2) from the mesosphere and lower thermosphere (MLT) into the stratosphere. This caused NOx enhancements in the polar upper stratosphere in April 2004 that were unprecedented in the satellite record. Simulations of the 2003–2004 Arctic winter with the Whole Atmosphere Community Climate Model using Specified Dynamics (SD‐WACCM) are compared to satellite measurements to assess our understanding of the observed NOx enhancements. The comparisons show that SD‐WACCM clearly displays the descent of NOx produced by EPP but underestimates the enhancements by at least a factor of four. Comparisons with NO measurements in January and February indicate that SD‐WACCM most likely underestimates EPP‐induced NO production locally in the mesosphere because it does not include precipitation of high energy electrons. Comparisons with temperature measurements suggest that SD‐WACCM does not properly simulate recovery from a sudden stratospheric warming in early January, resulting in insufficient transport from the MLT into the stratosphere. Both of these factors probably contribute to the inability of SD‐WACCM to simulate the stratospheric NOx enhancements, although their relative importance is unclear. The work highlights the importance of considering the full spectrum of precipitating electrons in order to fully understand the impact of EPP on the atmosphere. It also suggests a need for high‐quality meteorological data and measurements of NOx throughout the polar winter MLT.
Detection and attribution of urbanization effect on flood extremes using nonstationary flood‐frequency models
Authors: Prosdocimi I. , Kjeldsen T. R. , Miller J. D.
Published: May 2015

This study investigates whether long‐term changes in observed series of high flows can be attributed to changes in land use via nonstationary flood‐frequency analyses. A point process characterization of threshold exceedances is used, which allows for direct inclusion of covariates in the model; as well as a nonstationary model for block maxima series. In particular, changes in annual, winter, and summer block maxima and peaks over threshold extracted from gauged instantaneous flows records in two hydrologically similar catchments located in proximity to one another in northern England are investigated. The study catchment is characterized by large increases in urbanization levels in recent decades, while the paired control catchment has remained undeveloped during the study period (1970–2010). To avoid the potential confounding effect of natural variability, a covariate which summarizes key climatological properties is included in the flood‐frequency model. A significant effect of the increasing urbanization levels on high flows is detected, in particular in the summer season. Point process models appear to be superior to block maxima models in their ability to detect the effect of the increase in urbanization levels on high flows.
Landscape reorganization under changing climatic forcing: Results from an experimental landscape
Authors: Singh Arvind , Reinhardt Liam , Foufoula‐Georgiou Efi
Published: May 2015

Understanding how landscapes respond to climate dynamics in terms of macroscale (average topographic features) and microscale (landform reorganization) is of interest both for deciphering past climates from today's landscapes and for predicting future landscapes in view of recent climatic trends. Although several studies have addressed macro‐scale response, only a few have focused on quantifying smaller‐scale basin reorganization. To that goal, a series of controlled laboratory experiments were conducted where a self‐organized complete drainage network emerged under constant precipitation and uplift dynamics. Once steady state was achieved, the landscape was subjected to a fivefold increase in precipitation (transient state). Throughout the evolution, high‐resolution spatiotemporal topographic data in the form of digital elevation models were collected. The steady state landscape was shown to possess three distinct geomorphic regimes (unchannelized hillslopes, debris‐dominated channels, and fluvially dominated channels). During transient state, landscape reorganization was observed to be driven by hillslopes via accelerated erosion, ridge lowering, channel widening, and reduction of basin relief as opposed to channel base‐level reduction. Quantitative metrics on which these conclusions were based included slope‐area curve, correlation analysis of spatial and temporal elevation increments, and wavelet spectral analysis of the evolving landscapes. Our results highlight that landscape reorganization in response to increased precipitation seems to follow “an arrow of scale”: major elevation change initiates at the hillslope scale driving erosional regime change at intermediate scales and further cascading to geomorphic changes at the channel scale as time evolves.
Aqueous Solution‐Processable Small Molecular Metal‐Chelate Complex Electrolyte for Flexible All‐Solid State Energy Storage Devices
Authors: Lee Hyena , Jeong Jaehoon , Kim Hwajeong , Kim Youngkyoo
Published: May 2015

A small molecular metal‐chelate complex, tris(8‐hydroxyquinoline‐5‐sulfonic acid) aluminum (AlQSA3), that has three sulfonic acid groups per molecule leading to an excellent solubility in water is reported as a liquid‐free perfect solid‐state electrolyte for flexible film‐type all‐solid‐state energy storage devices. The AlQSA3 material is synthesized by one‐step reaction of aluminum triisopropoxide and 8‐hydroxyquinoline‐5‐sulfonic acid. The aqueous solutions of AlQSA3 are applied to fabricate flexible film‐type all‐solid state electric double layer capacitors with indium‐tin oxide thin film electrodes. The ion conductivity of the AlQSA3 film reaches 0.116 mS cm−1, while a pronounced hysteresis are obtained in the cyclic voltammetry measurement. The AlQSA3 film capacitors exhibit an output voltage of 1.5 V at 20 μA cm−2, which is considerably stable by the repeated operation. In particular, the peak output voltage is well kept even after 180° bending for 500 times in the case of the flexible AlQSA3 film capacitors.
Multiscale model for solid oxide fuel cell with electrode containing mixed conducting material
Authors: Chen Daifen , Wang Hanzhi , Zhang Shundong , Tade Moses O. , Shao Zongping , Chen Huili
Published: May 2015

Solid oxide fuel cells (SOFCs) with electrodes that contain mixed conducting materials usually show very different relationships among microstructure parameters, effective electrode characteristics, and detailed working processes from conventional ones. A new multiscale model for SOFCs using mixed conducting materials, such as LSCF or BSCF, was developed. It consisted of a generalized percolation micromodel to obtain the electrode properties from microstructure parameters and a multiphysics single cell model to relate these properties to performance details. Various constraint relationships between the activation overpotential expressions and electric boundaries for SOFC models were collected by analyzing the local electrochemical equilibrium. Finally, taking a typical LSCF‐SDC/SDC/Ni‐SDC intermediate temperature SOFC as an example, the application of the multiscale model was illustrated. The accuracy of the models was verified by fitting 25 experimental I‐V curves reported in literature with a few adjustable parameters; additionally, and several conclusions were drawn from the analysis of simulation results. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3786–3803, 2015
Micro‐structured Bi1.5Y0.3Sm0.2O3−δ catalysts for oxidative coupling of methane
Authors: Othman Nur Hidayati , Wu Zhentao , Li Kang
Published: May 2015

Bi1.5Y0.3Sm0.2O3−δ (BYS), a ceramic material showing great activity and selectivity to oxidative coupling of methane (OCM), has been fabricated into catalyst rings (i.e., capillary tubes) with a plurality of self‐organized radial microchannels. The unique microchannels inside such BYS catalyst rings allow easier access of reactants, as well as increased the surface area, which potentially contributes to higher reaction efficiencies due to improved mass transfer. The micro‐structured BYS catalyst rings were investigated systematically via two types of reactors; (1) randomly packed fixed bed reactor and (2) monolithic‐like structured reactor. These two reactor designs have different flow patterns of reactants, that is, non‐ideal and ideal flows, which can significantly affect the final OCM performance. A remarkable improvement in C2+ yield (YC2+ > 20%) was obtained in the monolith‐like structured reactor, in contrast to randomly packed powder and micro‐structured rings (YC2+ < 15%), which proves the advantages of using a micro‐structured catalyst with an ideal flow in the feed for OCM. © 2015 American Institute of Chemical Engineers AIChE J, 61: 3451–3458, 2015
Research on properties of rigid polyurethane foam with heteroaromatic and brominated benzyl polyols
Authors: Guo Hong , Gao Qun , Ouyang Chunfa , Zheng Kangsheng , Xu Wei
Published: May 2015

Rigid polyurethane foams (RPUFs) were prepared with specific heteroaromatic and brominated benzyl polyols. The mechanical properties and thermal stability were studied using dynamic mechanical analysis (DMA) and thermogravimetric analysis (TG). The limiting oxygen index (LOI) was used to investigate the flame retardancy of the RPUFs. The results showed that the glass transition temperature (Tg) of the RPUF prepared by heteroaromatic polyol was 182°C, demonstrating an improved thermal stability for this specific heteroaromatic polyol. Brominated benzyl polyol exhibited less negative influence on mechanical properties of the RPUFs at the same time of improving the flame retardancy. The LOI values increased with an increase in the brominated polyol content to 27.5%, and the char‐forming ability of the RPUF improved; the char residue rate reached 12.6% at 700°C, but it was only 6.2% without the flame retardant. Scanning electron microscope (SEM) and energy‐dispersive spectrometry (EDS) verified that the mechanism of flame retardancy was due to a synergistic effect of the gas phase and the condensed phase. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42349.
Synthesis of seaweed polysaccharide‐based polyvinylpyrrolidone copolymer with adhesive properties
Authors: Chhatbar Mahesh U. , Siddhanta Arup K.
Published: May 2015

Polyvinylpyrrolidone (PVP) grafted sulfated polysaccharide of the seaweed Cystoseira indica (CIsps) (CIsps‐graft‐PVP) was synthesized in aqueous medium under microwave irradiation in the presence of potassium persulfate (KPS), as a free radical initiator. Varying the reaction parameters, e.g., concentration of PVP and KPS, reaction time and temperature, optimum grafting condition was identified as the one having the highest grafting ratio (Gr 2.30) and grafting efficiency (Ge 0.92). The grafted copolymer was characterized by FT‐IR, 13C‐NMR and thermo gravimetric analysis (TGA). The 5% (w/v) dispersion of the new material CIsps‐graft‐PVP in water exhibited comparable binding properties with papers, polyethylene sheets, and wood pieces as against that of a commercial adhesive. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42383.
An UV‐curable epoxy acrylate oligomer with high refractive index containing fluorene: Preparation, characterization, and application
Authors: Chen Jia , Zhou Yuming , Ding Qinghua , He Man
Published: May 2015

In this article, a novel UV‐curable epoxy acrylate oligomer (BPEFPGMA) with high refractive index is successfully prepared through semi‐esterification reaction of 9,9‐bis[4‐(2‐hydroxyethoxy)phenyl]fluorene and phthalic anhydride, followed by end‐caping of glycidyl methacrylate. After 15 times’ repetitions, the process and properties of this oligomer are stable and reliable. The resulting BPEFPGMA exhibited low solvent content (≤1600 ppm), low viscosity (1900–2500 mPa s at 60°C), high refractive index (1.587 ± 0.003 at 20°C), and normal Mw (2550–3536 g/mol). The coating formulations of 1.57 UV‐curable glue are mixed with BPEFPGMA as reactive oligomer. Through the technology of UV‐curing forming, the corresponding brightness enhancement films are obtained. The resulting films exhibit normal structure, excellent adhesion (5B), good scratch resistance (50 g), and good abrasion resistance (50 g). They show excellent performance, and have reached the quality standard for use in liquid crystal display industry. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42386.
Polyvinylbutyral‐assisted synthesis and characterization of SnS mesoporous fibers via electrospinning process
Authors: Hsu Kuo‐Chin , Wu Dong‐Yang , Lin Pei‐Ying , Fu Yaw‐Shyan , Liao Jiuun‐Der
Published: May 2015

Tin sulfide (SnS) has the potential to be used as a low‐cost absorber material for applications in thin film photovoltaic solar cells. In this study, polyvinylbutyral/SnS (PVB/SnS) composite fibers were synthesized through a relatively simple electrospinning process. SnS mesoporous fibers were obtained from PVB/SnS composite fibers after sintering treatment at 500°C for 1 h in N2 atmosphere. The SnS mesoporous fibers were then characterized using X‐ray powder diffraction, scanning electron microscopy, thermogravimetric analysis, and transmission electron microscopy. The optical properties of SnS mesoporous fibers were also recorded by UV–vis absorption spectroscopy. The results showed that the synthesized SnS mesoporous fibers exhibited a single phase, stoichiometric composition, with good crystallinity, a size ranging from 100 to 200 nm, and a band gap of 1.49 eV. The as‐prepared SnS mesoporous fibers are thus a suitable material to achieve visible light absorption in a thin film solar cell. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42388.
Preparation of zirconia loaded poly(acrylate) antistatic hard coatings on PMMA substrates
Authors: Chang Chao‐Ching , Hsieh Chin‐Yuan , Huang Feng‐Hsi , Cheng Liao‐Ping
Published: May 2015

Zirconia (ZrO2) nanoparticles were synthesized by hydrolysis and condensation of zirconium‐n‐propoxide (ZNP) in 1‐propanol at the presence of methacrylic acid (MA), serving as a chelating agent for ZNP. The formed nanoparticles were chemically modified by the UV‐curable coupling agent, 3‐(trimethoxysilyl)propyl methacrylate (MSMA). The modified particles were then crosslinked with the hexa‐functional monomer, dipentaerythritol hexaacrylate (DPHA), to produce transparent antistatic hard coatings on poly(methyl methacrylate) (PMMA) substrates. Sizes of the modified particles, as determined by the dynamic light scattering technique, fell over a small range of 2–20 nm. Chemical analyses of the particles and the coatings were performed using FTIR and/or solid 29SiNMR spectroscopy. Surface resistivities of the coatings were measured, and the results indicated that with inclusion of 10 wt % modified zirconia, surface resistivity of ∼109 Ω/sq could be achieved, which amounted to ∼6 order magnitude lower than that of the particle‐free polymeric binder. Furthermore, this antistatic coating was very hard with pencil hardness of 8–9H, and attached perfectly to the PMMA substrate according to the peel test. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42411.
Advanced ultra‐high molecular weight polyethylene/antioxidant‐functionalized carbon nanotubes nanocomposites with improved thermo‐oxidative resistance
Authors: Dintcheva Nadka Tzankova , Arrigo Rossella , Gambarotti Cristian , Carroccio Sabrina , Coiai Serena , Filippone Giovanni
Published: May 2015

Multiwalled carbon nanotubes (CNTs) functionalized with hindered phenol moieties are dispersed in ultra‐high molecular weight polyethylene (UHMWPE), and the stabilizing action of the antioxidant (AO) functionalized CNTs (AO‐f‐CNTs) is studied through a combination of rheological and spectroscopic (FT‐IR) analyses. The effectiveness of two alternative compounding methods, namely hot compaction (HC) and melt mixing (MM), is compared. The combination of high temperature and mechanical stress experienced during MM brings about noticeable degradation phenomena of the matrix already in the course of the compounding step. Differently, the milder conditions of the HC process preserve the stability of the polymer, making this method preferable when dealing with highly viscous matrices. In addition, HC guarantees a better CNT dispersion, allowing for the maximization of the stabilizing action of the AO grafted on the nanotubes. As a result, the HC samples exhibit improved thermo‐oxidative resistance despite the very low amount of AO grafted onto the CNTs. Besides demonstrating the effectiveness of our AO‐f‐CNTs as stabilizers for polymer matrices, our results prove that CNTs can serve as a support on which grafting specific functional molecules to be dispersed in a host polymer matrix. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42420.
Poly(l‐lactide)/zno nanocomposites as efficient UV‐shielding coatings for packaging applications
Authors: Lizundia Erlantz , Ruiz‐Rubio Leire , Vilas José Luis , León Luis Manuel
Published: May 2015

Poly(l‐lactide) (PLLA)/ZnO nanocomposites have been developed as efficient UV‐shielding coatings for packaging applications. ZnO have been selected as the most suitable UV‐shielding material over 10 different metallic nanoparticles. Results reveal a nucleating effect of ZnO in which PLLA crystallization half time is reduced from 7.4 to 4.7 min with only 0.05 wt % ZnO. UV–vis spectroscopy confirms the UV‐shielding effect in PLLA/ZnO nanocomposites, where the ultraviolet spectrum is blocked by 61.2% for a concentration as low as 0.45 vol %, while the 95.9% of the visible radiation passes through the material. A schematic representation explaining obtained UV‐shielding effect is constructed based on the photon mean free path reduction as ZnO concentration increases. Water contact angle increased from 81° up to 91° for the 5 wt % nanocomposite, which would result beneficial in view to develop materials for packaging applications. Dynamic mechanical analysis exhibits a Tg increase with nanoparticle loading arising from the chain confinement caused by the presence of ZnO interacting surfaces. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42426.
Characterization of poly (N‐vinyl formamide) by size exclusion chromatography–multiangle light scattering and asymmetric‐flow field‐flow fractionation–multiangle light scattering
Authors: Zataray Julieta , Agirre Amaia , Carretero Paula , Meabe Leire , de la Cal José C. , Leiza Jose R.
Published: May 2015

The molar mass and the radius of gyration of three poly N‐vinyl formamide (polyNVF) synthesized in aqueous solution polymerization were characterized using two different fractionation techniques: size exclusion chromatography (SEC) and asymmetric‐flow field‐flow fractionation (AF4) coupled with a multiangle light scattering (MALS) and a refractive index (RI) detector. For the sake of comparison, the polymers were also characterized by MALS using the Zimm plot approach (no fractionation). The dn dc−1 of the poly (N‐vinyl formamide) was measured (0.1564 mL g−1) and it was found to be insensitive to the molar mass (in the range 150–450 kDa) and also to the eluents used (DDI water or mixed eluent DDI water/acetonitrile (80 : 20) at pH = 5.5). Interestingly, the concentrations of the samples injected in the SEC and AF4 should be different because concentrations in the range of 20–40 mg mL−1 used for the AF4 caused overloading and anomalous elution in the SEC and hence misleading molar masses. At adequate concentrations in each fractionation equipment, the molar masses were in reasonable good agreement although AF4/MALS provided larger values than the other two techniques likely because samples were not filtered before injection. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42434.
Polypropylene reinforced with nanocrystalline cellulose: Coupling agent optimization
Authors: Hassanabadi Hojjat Mahi , Alemdar Ayse , Rodrigue Denis
Published: May 2015

Five different grades of maleic anhydride polypropylene (MAPP) having different molecular weight and acid value (AV) were used as coupler in PP‐nanocrystalline cellulose (NCC) composites. The main objective was to study the effect of MAPP structure (Mw, AV) and filler/coupler (F/C) ratio on mechanical properties in order to find optimum mechanical properties in tension, flexion, and impact. Results showed that both Mw and AV have direct effect on mechanical properties and a balance between both must be achieved to get the best performance. However, regardless of MAPP structure, optimum improvement was obtained for F/C = 7.5/1. Shear rheological data showed that at high MAPP content, MAPP acts as lubricant. DSC and AFM analysis showed small reduction in the size of PP crystals in the presence of NCC. Rheological data under large amplitude oscillatory shear showed that the nanocomposites used here are under percolation. Using these analyses, possible reinforcement mechanisms were investigated. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42438.
Few‐layer‐graphene/polycarbonate nanocomposites as dielectric and conducting material
Authors: Sain P. K. , Goyal R. K. , Prasad Y. V. S. S. , Jyoti  , Sharma K. B. , Bhargava A. K.
Published: May 2015

An attempt is taken to develop a flexible and light weight polycarbonate‐based nanocomposite system which could be successfully used as a dielectric material below percolation and as conducting material beyond percolation. The nanocomposite system has been prepared by solution mixing method in which few layer graphene was incorporated as conductive filler. X‐ray diffractometry, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy techniques were employed for characterization studies. The dielectric constant and conductivity were evaluated using precision impedance analyzer. Percolation threshold has been observed to occur at 3.5 wt % of few layer graphene. Dielectric constant of the nanocomposite system, in the smearing region, has been found to increase from ∼3.3 (without filler) to ∼70 (at 5 wt % FLG) with a dissipation factor of 0.07. The conductivity of the system was increased from 10−9 S/cm without FLG to 10−2 S/cm with 7 wt % of few layer graphene. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42443.
An investigation of sound absorption coefficient on sisal fiber poly lactic acid bio‐composites
Authors: Jayamani Elammaran , Hamdan Sinin , Rahman Md Rezaur , Bakri Muhammad Khusairy Bin , Kakar Akshay
Published: May 2015

In this research, the mechanical, acoustical, thermal, morphological, and infrared spectral properties of untreated, heat and alkaline‐treated sisal fiber‐reinforced poly‐lactic‐acid bio‐composites were analyzed. The bio‐composite samples were fabricated using a hot press molding machine. The properties mentioned above were evaluated and compared with heat‐treated and alkaline‐treated sisal fibers. Composites with heat‐treated sisal fibers were found to exhibit the best mechanical properties. Thermo‐gravimetric analysis (TGA) was conducted to study the thermal degradation of the bio‐composite samples. It was discovered that the PLA‐sisal composites with optimal heat‐treated at 160°C and alkaline‐treated fibers possess good thermal stability as compared with untreated fiber. The results indicated that the composites prepared with 30wt % of sisal had the highest sound absorption as compared with other composites. Evidence of the successful reaction of sodium hydroxide and heat treatment of the sisal fibers was provided by the infrared spectrum and implied by decreased bands at certain wavenumbers. Observations based on scanning electron microscopy of the fracture surface of the composites showed the effect of alkaline and heat treatment on the fiber surface and improved fiber‐matrix adhesion. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42470.
A promising RVO4:Eu3+,Li+@SiO2 (R = Gd, Y and Gd/Y) red‐emitting phosphor with improved luminescence (cd/m2) and colour purity for optical display applications
Authors: Rambabu Urlagaddala , Munirathnam Nagegownivari Ramachandra , Reddy Busireddy Sudhakar , Chatterjee Sandip
Published: May 2015

Red emission intensity was optimized in three stages, by investigating the effects of: (i) host composition (Gd, Y and Gd/Y), (ii) codoping Li+ as a sensitizer and, finally, (iii) with a SiO2 shell coating as a protecting layer. Lanthanide vanadate powder phosphors were synthesized using a modified colloidal precipitation technique. The effects of SiO2 coating on phosphor particles were characterized using scanning electron microscopy (SEM)‐EDAX, transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and photoluminescence (PL) measurements. An improvement in the PL intensity on Li codoping was due to improved crystallinity, which led to higher oscillating strengths for the optical transitions, and also a lowering of the inversion symmetry of Eu3+ ions. Red emission intensity due to 5D0 → 5D2 transition of the phosphor Y0.94VO4:Eu3+0.05,Li+0.01 was enhanced by 22.28% compared with Y0.95VO4:Eu3+0.05, and was further improved by 58.73% with SiO2 coating. The luminescence intensity (I) and colour coordinates (x, y) of the optimized phosphor Y0.94VO4:Eu3+0.05,Li+0.01@SiO2, where I = 13.07 cd/m2 and (x = 0.6721, y = 0.3240), were compared with values for a commercial red phosphor (Y2O2S:Eu3+), where I = 27 cd/m2 and (x = 0.6522, y = 0.3437). The measured colour coordinates are superior to those of the commercial red phosphor, and moreover, match well with standard NTSC values (x = 0.67, y = 0.33). Copyright © 2015 John Wiley & Sons, Ltd.
Microfluidic wound model for studying the behaviors of Pseudomonas aeruginosa in polymicrobial biofilms
Authors: Wright Evan , Neethirajan Suresh , Weng Xuan
Published: May 2015

Pseudomonas aeruginosa is a particularly problematic opportunistic pathogen due to its capacity to form recalcitrant biofilm structures, while cohabiting with other harmful/pathogenic species and harboring the capability to release toxins that cause tissue necrosis. Although it is now recognized that the majority of biofilm infections are polymicrobial, little is known about the complex interactions that occur within polymicrobial communities and few tools exist for studying these interactions. In this study, we have designed a microfluidic model that mimics the relevant physiological properties of wound microenvironment, while incorporating materials present in the human extracellular matrix/wound environment. Using microfluidics combined with imaging techniques, we have validated the robustness of our model comparing traditional GFP‐tagging to new fluorescent staining techniques to visualize/resolve individual species within a polymicrobial habitat. We have also demonstrated that chemotactic stimuli may be incorporated into our model through specialized ports in our chamber. Our system is specifically designed for use with high resolution imaging techniques, allowing for data collection throughout the life of the biofilm and in real‐time. Ultimately, this model can be used to investigate the spatio‐temporal mechanobiological structures of the wound environment, and the response of the bacteria to the drug transport which will significantly contribute to our understanding of the development and progression of polymicrobial biofilm infections. Biotechnol. Bioeng. 2015;112: 2351–2359. © 2015 Wiley Periodicals, Inc.
Hyperthermia approaches for enhanced delivery of nanomedicines to solid tumors
Authors: Frazier Nick , Ghandehari Hamidreza
Published: May 2015

Drug delivery to solid tumors has received much attention in order to reduce harmful side effects and improve the efficacy of treatment. Different strategies have been utilized with nanoparticle drug delivery systems, or nanomedicines, including passive and active targeting strategies, as well as the incorporation of stimuli sensitivity. Additionally, hyperthermia has been used in combination with such systems to further improve accumulation, localization, penetration, and subsequently efficacy. Localized hyperthermia within the solid tumor tissue can be applied through different mechanisms able to trigger vascular and cellular mechanisms for enhanced delivery of nanomedicines. This review covers the use of nanoparticles in drug delivery, the different methods for inducing localized hyperthermia, combination effects of hyperthermia, and successful strategies for improving the delivery of nanomedicines using hyperthermia. Biotechnol. Bioeng. 2015;112: 1967–1983. © 2015 Wiley Periodicals, Inc.
A flexible toolbox to study protein‐assisted metalloenzyme assembly in vitro
Authors: Schiffels Johannes , Selmer Thorsten
Published: May 2015

A number of metalloenzymes harbor unique cofactors, which are incorporated into the apo‐enzymes via protein‐assisted maturation. In the case of [NiFe]‐hydrogenases, minimally seven maturation factors (HypABCDEF and a specific endopeptidase) are involved, making these enzymes an excellent example for studying metallocenter assembly in general. Here, we describe an innovative toolbox to study maturation involving multiple putative gene products. The two core elements of the system are a modular, combinatorial cloning system and a cell‐free maturation system, which is based on recombinant Escherichia coli extracts and/or purified maturases. Taking maturation of the soluble, oxygen‐tolerant [NiFe]‐hydrogenase (SH) from Cupriavidus necator as an example, the capacities of the toolbox are illustrated. In total 18 genes from C. necator were analyzed, including four SH‐structural genes, the SH‐dedicated hyp‐genes and a second set of hyp‐genes putatively involved in maturation of the Actinobacterium‐like hydrogenase (AH). The two hyp‐sets were either expressed in their entirety from single vectors or split into functional modules, which enabled flexible approaches to investigate limitations, specificities and the capabilities of individual constituents to functionally substitute each other. Affinity‐tagged Hyp‐Proteins were used in pull‐down experiments to demonstrate direct interactions between dedicated or non‐related constituents. The dedicated Hyp‐set from C. necator exhibited the highest maturation efficiency in vitro. Constituents of non‐related maturation machineries were found to interact with and to accomplish partial activation of SH. In contrast to homologues of the Hyp‐family, omission of the SH‐specific endopeptidase HoxW completely abolished in vitro maturation. We detected stoichiometric imbalances inside the recombinant production system, which point to limitations by the cyanylation complex HypEF and the premature subunit HoxH. Purification of HoxW revealed strong indications for the presence of a putative [4Fe‐4S]‐cluster, which is unique among this class of maturases. Results are discussed in the context of [NiFe]‐hydrogenase maturation, and in light of the capacity of the novel toolbox. Biotechnol. Bioeng. 2015;112: 2360–2372. © 2015 Wiley Periodicals, Inc.
Lipophilicity study of eight cephalosporins by reversed‐phase thin‐layer chromatographic method
Authors: Dąbrowska Monika , Komsta Łukasz , Krzek Jan , Kokoszka Kinga
Published: May 2015

The lipophilicity (RM0) and specific hydrophobic surface area for the representatives of four generation cephalosporins have been determined by reversed‐phase thin‐layer chromatography, and the effect of different mobile‐phase modifiers (such as methanol, acetonitrile, acetone, 1,4‐dioxane and 2‐propanol) on the retention has been studied. The compounds studied showed typical retention behavior; their RM values decreased linearly with increasing concentration of the organic modifier in the eluent. The linear correlations between the volume fraction of the organic solvent and the RM values over a limited range were established for each solute, resulting in high values of correlation coefficients (>0.95 in most cases). RM values were determined by various concentrations of organic modifier, and the correlation obtained was extrapolated to 0% of organic modifier. Chromatographically established logP (RM0) parameters were compared with computationally calculated partition coefficients values (AClogP, ALOGP, KOWWIN, ALOGPs, XLOGP2, MLOGP and XLOGP3) and experimental octanol–water logP values (measured by the shake flask method). The received results demonstrate that RP‐TLC may be a good alternative technique for analytics in describing the lipophilic nature of investigated cephalosporins as well as the activity. Copyright © 2015 John Wiley & Sons, Ltd.
Adsorption of cinnabarinic acid from culture fluid with magnetic microbeads
Authors: Göçenoğlu Sarıkaya Aslı , Osman Bilgen , Kara Ali , Pazarlioglu Nurdan , Beşirli Necati
Published: May 2015

In this study, antimicrobial pigment cinnabarinic acid (CA) was produced from Pycnoporus cinnabarinus in laboratory‐scale batch cultures. Magnetic poly(ethylene glycol dimethacrylate‐N‐methacryloyl‐l‐tryptophan methyl ester) [m‐poly(EGDMA‐MATrp)] beads (average diameter = 53–103 µm) were synthesized by copolymerizing of N‐methacryloyl‐l‐tryptophan methyl ester (MATrp) with ethylene glycol dimethacrylate (EGDMA) in the presence of magnetite (Fe3O4) and used for the adsorption of CA. The m‐poly(EGDMA‐MATrp) beads were characterized by N2 adsorption/desorption isotherms (Brunauer Emmet Teller), X‐ray photoelecron spectroscopy, scanning electron microscopy, infrared spectroscopy, thermal gravimetric analysis, electron spin resonance and swelling studies. The efficiency of m‐poly(EGDMA‐MATrp) beads for separation of CA from culture fluid was evaluated. The effects of pH, initial concentration, contact time and temperature on adsorption were analyzed. The maximum CA adsorption capacity of the m‐poly(EGDMA‐MATrp) beads was 272.9 mg g−1 at pH 7.0, 25 °C. All the isotherm data can be fitted with the Langmuir, Freundlich and Dubinin–Radushkevich isotherm models. The adsorption process obeyed pseudo‐second‐order kinetic model. Thermodynamic parameters ΔH = 5.056 kJ mol−1, ΔS = 52.44 J K−1 mol−1 and ΔG = −9.424 kJ mol−1 to ‐11.27 kJ mol−1 with the rise in temperature from 4 to 40 °C indicated that the adsorption process was endothermic and spontaneous. Copyright © 2015 John Wiley & Sons, Ltd.
The long‐term outcomes of alternating chemoradiotherapy for locoregionally advanced nasopharyngeal carcinoma: a multiinstitutional phase II study
Authors: Fuwa Nobukazu , Kodaira Takeshi , Daimon Takashi , Yoshizaki Tomokazu
Published: May 2015

To examine the long‐term outcomes of alternating chemoradiotherapy (ALCRT) for patients with locoregionally advanced nasopharyngeal carcinoma (NPC) and to assess the efficacy of ALCRT for NPC. Patients with stage IIB to IVB, ECOG PS 0–2, 18–70 years‐old, and sufficient organ function were eligible for this study. First, chemotherapy, consisting of 5‐fluorouracil (800 mg/m2 per 24 h on days 1–5) and cisplatin (100 mg/m2 per 24 h on day 6), was administered, then a wide field of radiotherapy (36 Gy/20 fraction), chemotherapy, a shrinking field of radiotherapy (34 Gy/17 fraction), and chemotherapy were performed alternately. Between December 2003 and March 2006, 90 patients in 25 facilities were enrolled in this study, 87 patients were finally evaluated. A total of 67 patients (76.1%) completed the course of treatment. The overall survival and the progression‐free survival rates at 5 years were 78.04% (95% CI: 69.1~87.0%), and 68.74% (95% CI: 58.8~78.7%), respectively. The long‐term outcomes of ALCRT for NPC were thought to be promising. ALCRT will be considered to be a controlled trial to compare therapeutic results with those of concurrent chemoradiotherapy for NPC.
Genomic characterization of chromosome 8 pericentric trisomy
Authors: Vander Pluym Juliana H. , O'Sullivan Julia , Andrew Gail , Bolduc Francois V.
Published: May 2015

Key Clinical Message

We present a patient with trisomy 8p11.21q11.21 associated with language, gross motor, fine motor, and cognitive delay. Furthermore, using array‐based comparative genomic hybridization, we identify the specific genes duplicated in our patient.