bluuebunny/crossref_metadata_2025 huggingface dataset:
Bio Organic-Based Gate Dielectric Materials for Thin Film Transistors
Authors: Grote James G. , Ouchen Fahima , Joyce Donna M. , Singh Kristi M. , Venkat Narayanan , Smith Steven R. , Yaney Perry P. , Heckman Emily M. , Bartsch Carrie M. , Naik Rajesh R.
Published: November 2012

The potential of bio-dielectrics for thin film transistor applications was explored via the incorporation of titanium dioxide (TiO2) nanoparticles, rutile form, a high dielectric constant (ε) ceramic, in the deoxyribonucleic acid (DNA) bio-polymer. The DNA-ceramic hybrid films were fabricated from stable suspensions of the TiO2 nanoparticles in viscous, aqueous DNA solutions. Dielectric characterization revealed that the incorporation of TiO2 in DNA resulted in enhanced dielectric constant (14.3 at 1 kHz for 40 wt % TiO2) relative to that of DNA in the entire frequency range of 1 kHz-1 MHz. Variable temperature dielectric measurements, in the 20-80°C range, of the DNA-TiO2 films revealed that the ceramic additive stabilizes DNA against large temperature dependent variations in both ε and the dielectric loss factor tan δ. The bulk resistivity of the DNA-TiO2 hybrid films was measured to be two to three orders of magnitude higher than that of the control DNA films, indicating their potential for utilization as insulating dielectrics in transistor and capacitor applications.
Plasma agriculture based on quantitative monitoring of reactions between fungal cells and atmospheric-pressure plasmas
Authors: Ito Masafumi , Ohta Takayuki , Takeda Keigo
Published: November 2012

A high-density non-equilibrium atmospheric pressure plasma (NEAPP) applied for inactivating fungal spores of P. digitatum is introduced as an environmentally safe and rapid-inactivation method. The contributions of ozone, ultra violet (UV) radiation and ground-state atomic oxygen in the NEAPP on the inactivation of the spores are evaluated using colony count method.

The absolute densities of ozone were measured by using ultraviolet absorption spectroscopy. The ozone density increased from 2 to 8 ppm with an increase in the distance from the plasma source, while the inactivation rate decreased. The inactivation rate of plasma was evaluated to be thousand times higher than that of an ozone generator using the integrated number density of ozone. In addition, it was clarified that the contribution of UV radiation to inactivation was not dominant for P. digitatum inactivation by NEAPP by filtering the active species using quartz plate. From these results, we can speculate that the inactivation efficiency of reactive oxygen species (ROS) will be larger than those of others.

In order to investigate the effect of ground-state atomic oxygen as one of ROS, the inactivation of P. digitatum spores using an oxygen radical source that employs a high-density atmospheric-pressure O2/Ar plasma. The absolute O density was measured to be 1.4×1014 and 1.5×1015 cm–3 using vacuum ultra violet absorption spectroscopy (VUVAS) using a microdischarge hollow cathode lamp. The behaviors of the O densities as a function of O2/(Ar+O2) mixture flow rate ratio correspond to that of the inactivation rate. This result indicates that ground-state atomic oxygen is concluded to be the dominant species that causes inactivation.
Microencapsulation of Liquid Cyanoacrylate via In situ Polymerization for Self-healing Bone Cement Application
Authors: Gandham Vineela D. , Brochu Alice B.W. , Reichert William M.
Published: November 2012

Structural polymers are susceptible to accumulated damage in the form of internal microcracks that propagate through the material, resulting in mechanical failure. Self- healing approaches offer a solution to repair these damages automatically. The first generation self-healing material system includes a microencapsulated healing agent within a catalyst-embedded matrix. Propagating microcracks rupture the microcapsules, releasing the liquid healing agent into the damaged region. Catalyst-triggered polymerization of the released healing agent repairs the damage. Our research focuses on a similar approach for addressing “damage accumulation failure” of poly(methyl methacrylate) (PMMA) bone cement caused by microcrack initiation and propagation. In this study, polyurethane (PU) microcapsules containing a tissue adhesive, 2-octylcyanoacrylate (OCA) were synthesized using in situ interfacial polymerization of toluene-2,4-diisocynate (TDI) and polyethylene glycol 200 (PEG 200) through an oil-in-oil-in-water microemulsion (o/o/w). The process was optimized by studying different combinations of organic solvents, surfactants, temperatures, agitation rates, pH, and reaction times and their effects on microencapsulation were observed. Microcapsule surface morphology, size, shell thickness, encapsulated OCA viability, thermal degradation, and chemical structure of the microcapsule shell were evaluated using a stereoscope, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and fourier transform infrared spectroscopy (FT-IR).
Stability of Electrical Characteristics of SiC “Super” Junction Transistors under Long-Term DC and Pulsed Operation at various Temperatures
Authors: Sundaresan Siddarth G. , Soe Aye-Mya , Singh Ranbir
Published: November 2012

The reliability of the electrical characteristics of SiC “Super” Junction Transistors (SJTs) is investigated under long-term avalanche-mode, DC and pulsed-current operation. There is absolutely no change in the blocking I-V characteristics after a 934 hour repetitive avalanche stress test. Long-term operation of the Gate-Source diode (open-Drain mode) alone does not result in any degradation of the on-state voltage drop (VF) or current gain (β). Long-term operation in common-Source mode results in negligible VF or β degradation, if the base-plate is maintained at 25 °C. A greater degradation of β results with increasing base-plate temperature. The same total electrical charge, if passed through the SJT as a pulsed current instead of a DC current results in a smaller β reduction. It is also shown that this β degradation can be reversed by annealing at ≥ 200 °C, suggesting the possibility of degradation-free operation of SiC SJTs, when operating in pulsed current mode at ≥ 200 °C temperatures.
Growth and processing of heteroepitaxial 3C-SiC films for electronic devices applications
Authors: Severino A. , Mauceri M. , Anzalone R. , Canino A. , Piluso N. , Vecchio C. , Camarda M. , Via F.La
Published: November 2012

3C-SiC is very attractive due the chance to be grown on large-area, low-cost Si substrates. Moreover, 3C-SiC has higher channel electron mobility with respect to 4H-SiC, interesting property in MOSFET applications. Other application fields where 3C-SiC can play a significant role are solar cells and MEMS-based sensors. In this work, we present a general overview of 3C-SiC growth on Si substrate. The influence of growth parameters, such as the growth rate, on the crystal quality of 3C-SiC films is discussed. The main issue for 3C-SiC development is the reduction of the stacking fault density, which shows an exponential decreasing trend with the film thickness tending to a saturation value of about 1000 cm-1. Some aspect of processing will be also faced with the realization of cantilever for Young modulus calculations and the implantation of Al ions for the study of damaging and recovery of the 3C-SiC crystal.
Conversion of Basal Plane Dislocations to Threading Edge Dislocations by High Temperature Annealing of 4H-SiC Epilayers
Authors: Zhang Xuan , Tsuchida Hidekazu
Published: November 2012

Conversion of basal plane dislocations (BPDs) to threading edge dislocations (TEDs) has been observed in 4H-SiC epilayers by simple high temperature annealing. Grazing incidence reflection synchrotron X-ray topography was used to image the dislocations in the epilayers. By comparing the X-ray topographs before and after annealing, some of the BPDs were confirmed to convert to TEDs from the epilayer surface. The dislocation behaviors during annealing are explained and the mechanism of BPD conversion is discussed. It is argued that the conversion process is realized by constricted BPD segments cross-slipping to the prismatic plane driven by the image force and TED glide on its slip plane driven by the line tension. Certain kinetic processes may assist the formation of constrictions on the BPDs.
Simple Structure and High Efficiency Phosphorescent OLEDs Using Narrow Band-gap Bipolar Host Material
Authors: Son Young Hoon , Kwon Jang Hyuk
Published: November 2012

We report high-efficiency phosphorescent blue OLEDs with an organic three stacked structure. Using a high-triplet-energy-hole transporting material of TAPC and a high-triplet-energy-electron transporting material of TmPyPB, the organic three stacked structure has been realized with three new narrow band-gap blue host materials. These host materials have bipolar characteristics and high triplet energy of >2.8 eV. Very low onset voltages of 2.8~3.0 V and driving voltages of 4.2~4.6 V to obtain a brightness of 1000 cd/m2 are achieved in this three stacked device configuration. Maximum external quantum efficiency above 20% is reported.
One- vs two-step preparation of antimicrobial coatings composed of laser ablated copper nanoparticles and poly-lactic acid
Authors: Longano Daniela , Ditaranto Nicoletta , Cioffi Nicola , Di Niso Francesca , Sibillano Teresa , Mezzapesa Francesco P. , Ancona Antonio , Conte Amalia , Del Nobile Matteo A. , Sabbatini Luigia , Torsi Luisa
Published: November 2012

Copper-containing nanomaterials have been developed as antimicrobial additives for food packaging applications. These nano-antimicrobials are composed of copper nanoparticles (CuNPs) embedded in poly-lactic acid (PLA), which has been selected as a biodegradable polymer matrix. Copper nanostructures have been synthesized by laser ablation following two different protocols: (I) one-pot synthesis in presence of PLA and (II) in absence of polymer matrix. In the latter route, the as prepared CuNPs suspension has been subsequently mixed to a PLA solution. The resulting dispersions have been directly drop-cast on several substrates. Nanoantimicrobials have been characterized by UV-Vis and x-ray photoelectron spectroscopies, and transmission electron microscopy. The kinetics of copper release in aqueous solution from antimicrobial nanomaterials have been studied by means of Electro-Thermal Atomic Absorption Spectroscopy. Finally, preliminary biological tests have been performed on Pseudomonas species by JIS methods (Japanese Industrial Standard, JIS Z 2801:2000).
Multi-Scale Modeling of Interstitial Dislocation Loop Growth in Irradiated Materials
Authors: Ye Bei , Yun Di , Insepov Zeke , Rest Jeffrey
Published: November 2012

In order to reduce the inherent uncertainty in kinetic theory models and promote their transition to become predictive methodologies, a multi-scale modeling approach is proposed and demonstrated in this work. KiValues of key materials properties such as point defect (vacancy and interstitial) migration enthalpies, as well as kinetic factors, such as dimer formation and defect recombination coefficients and self-interstitial atom – interstitial loop reaction rates, were obtained by ab initio/molecular dynamics calculations. A rate theory model was used to interpret the evolution of dislocation loops in irradiated molybdenum. Calculations of the dose dependence of average loop diameter were performed and compared to experimental measurements obtained from irradiations with high-energy electrons. The comparison demonstrates reasonable agreement between model-predicted and experiment-measured data.
Measurement of the Phonon Density of States of PuO2(+2%Ga)
Authors: Manley M. E. , Jeffries J. R. , Said A. H. , Marianetti C. A. , Cynn H. , Leu B. M. , Wall M.
Published: November 2012

Inelastic x-ray scattering measurements of the phonon density of states (DOS) of PuO2(+2%Ga) were made and compared to recent predictions from the literature made using three leading theoretical approaches; Density Functional Theory (DFT), DFT plus the Hubbard U (DFT+U), and Dynamical Mean-Field Theory (DMFT). The DFT prediction, which does not account for strong electronic correlations, underestimates the measured energies of most features. The DFT+U and DMFT predictions, which include approximations to strong correlation effects, more accurately reflect the low energy features but exaggerate splitting in the highest energy optic oxygen modes. The exaggeration of the splitting is worse for DFT+U than for DMFT. The transverse acoustic mode shows the least sensitivity to calculation type, and is well reproduced by all three theories. The longitudinal acoustic mode, which is thought to control the thermal conductivity, is more sensitive to calculation type, suggesting an important role for electronic correlations in making application-critical predictions.
Thermo-optics of Luminescent Solar Concentrators
Authors: Hajiaboli Ahmadreza , Andrews Mark P.
Published: November 2012

We present a numerical study on effect of temperature on the performance of a waveguide luminescent solar concentrator (LSC). The purpose is to determine how changes in temperature of the ambient environment of an LSC affect device performance. The thermo-optical coefficient of the polymer waveguide is modeled using the well known Prod’homme formulation and applied in a forward Monte Carlo ray-tracing simulation. We show that the number of collected photons decreases almost linearly as the ambient temperature increases from -50 ºC to +50ºC. This behavior is associated with several competing loss mechanisms in the waveguide. For example, increases in optical confinement due to increased refractive index at low temperature are opposed by increases in cone loss (escape loss) of photons. Other competing mechanisms that exhibit temperature dependence are explained in terms of a detailed balance treatment of the LSC as a function of temperature.
Manipulation of 10 – 40 μm Diameter Cells Using a Thermally Actuated Microgripper
Authors: Daunton Rachael , Gallant Andrew J. , Wood David
Published: November 2012

This work presents the successful fabrication of a thermally actuated U-shaped microgripper that has been specially designed to enable low voltage operation for bidirectional in plane deflection. The microgripper tips are carefully designed to match the biological species being manipulated, which has been demonstrated by the successful manipulation of 10 – 40 μm diameter particles used to simulate biological cells.
Improved Temperature Stability of Atomic Layer Deposition Coated Cellulose Nanocrystal Aerogels
Authors: Smith Sean W. , Chan Han , Buesch Christian , Simonsen John , Conley John F.
Published: November 2012

Atomic layer deposition (ALD) was used to coat cellulose nanocrystal (CNC) aerogel scaffolds with a thin conformal layer of Al2O3. Electron probe microanalysis indicates that the penetration of Al2O3 into the aerogel was greater than 50 μm. Thermogravimetric analysis (TGA) shows that Al2O3 coated CNC aerogel composites have improved temperature and oxidation resistance.
Antimony sulfide and Silver antimony sulfide absorbers for thin film solar cells
Authors: Jesús Capistrán M. , Nair M.T.S. , Nair P.K.
Published: November 2012

Thin films of antimony sulfide (Sb2S3) were prepared with different silver-ion content in a chemical deposition bath, and silver antimony sulfide (AgSbS2) was produced through the addition of higher concentrations of silver-ions in the bath. The chemical deposition solution mixture contained antimony trichloride (SbCl3) and sodium thiosulfate (Na2S2O3). For molar ratio, AgNO3:SbCl3, 0.002 – 0.02, XRD patterns of the Sb2S3-Ag films heated at 280 ºC match that of the mineral stibnite (Sb2S3). The optical band gap (Eg) of these films is in the 1.93-1.80 eV range. At higher molar concentrations of Ag, lower is the Eg of the films. Electrical conductivity under illumination (σph) is 7.4x10-5 Ω-1cm-1 for a film with Ag:Sb 0.002 in the bath, which is about three orders of magnitude higher than that of a film prepared without Ag. At Ag:Sb 0.2, the XRD pattern of the heated film shows the presence of Ag3SbS3 and AgSbS2. Single-phase AgSbS2 (cubic miargyrite, a = 0.5652 nm) film is formed for Ag:Sb 0.4 and the film heated at 260 oC. The Eg of the film is 1.75 eV for the Sb2S3/Ag-Sb-S film and 1.68 eV for AgSbS2. Solar cell structures of TCO(SnO2:F)/CdS(200 nm)/Sb2S3(150 nm)/graphite, as well as with Sb2S3-Ag absorbers were developed through sequential chemical deposition. The cells with the colloidal graphite paint on the absorber were heated at 260 ºC for 15 min each. The Voc of the cells are 620-635 mV, with the cell using Sb2S3-Ag (0.004) film showing a Jsc of 2.00 mA/cm2, which is higher than the 1.69 mA/cm2 observed in cells with Sb2S3 absorber. In cells using AgSbS2 absorber, Voc is 490 mV, and Jsc is very low, 0.12 mA/cm2. The present work offers a wider range of absorber materials for thin film and hybrid solar cells.
Ab initio determination of the elastic properties of cubic Ge1Sb2Te4
Authors: Kohary K. , Marmier A. S. H. , Wright C. D.
Published: November 2012

The elastic properties of chalcogenide materials used for phase change applications in rewritable optical media (such as CD-RW, DVD-RW, etc) are still poorly characterized and the previously published experimental and theoretical values show large discrepancies. In this manuscript, we review these results and carry out a careful analysis of the elastic properties of a model system, crystalline Ge1Sb2Te4, using density functional theory and elastic anisotropy considerations. We show that Ge1Sb2Te4exhibits significant anisotropy in its elastic properties.
A Thin-Film Infrared Absorber using CNT/Nanodiamond Nanocomposite
Authors: Sui Yu , Gokhale Vikrant J. , Shenderova Olga A. , McGuire Gary E. , Rais-Zadeh Mina
Published: November 2012

This paper reports on the fabrication and characterization of thin-film nanocomposites comprised of tangled carbon nanotubes in a polymer matrix. The concentration of nanotubes in the polymer was significantly increased using detonation nanodiamonds. Nanodiamonds reduce the surface forces between the polymer and the nanotubes and mitigate the agglomeration problem of nanotubes in polymer. This resulted in thinner and more uniform networks that are efficient absorbers of infrared energy over a broad spectrum, ranging from the visible to the mid-wavelength infrared. An infrared absorbance of 97% was achieved for a 1.6 μm thick nanocomposite film across the spectral range of 714 nm to 5 μm. The films are mechanically and thermally stable up to 300 °C, and can be integrated with microbolometers to enhance their responsivity.
Electrospun Nylon-Graphene Nanocomposites Synthesis and Microstructure
Authors: Albañil-Sanchez Loyda , Romo-Uribe Angel , Flores Araceli , Cruz-Silva R
Published: November 2012

There has been much interest in the last few years on materials reinforced with nanometer scale particles. These so-called nanocomposites can exhibit hybrid properties derived from its components. One of the most promising nanocomposites is that based on polymers reinforced with single-layered carbon sheets named graphene. The reason is that graphene can significantly improve the physical properties of the polymeric material once it is completely dispersed in the matrix. In this work nylon/graphene nanocomposites were prepared starting from the synthesis of graphite oxide (GO). Direct oxidation of graphite powder was utilized to produce GO. That is, the oxidation reaction produced graphite layers with functional groups containing oxygen. The aim was to increase the polarity of GO to enable a good dispersion in polar solvents. Then, nylon/graphene nanocomposites were prepared by reducing GO in the presence of nylon. Finally, non-woven membranes, with nanometer sized filaments, of nylon/graphene were electrospun. The morphology and microstructure of the nanocomposites was investigated via electron microscopy and X-ray diffraction.
Conductive AFM: Probing Nano-scale Electrical Properties of Model Cell Membranes
Authors: Farrar Paul , Atkinson Del , Gallant Andrew J.
Published: November 2012

Biologically relevant lipid bilayers supported on highly ordered pyrolytic graphite (HOPG) were probed both mechanically and electrically with a Conductive Atomic Force Microscope (C-AFM) capable of measuring ultra-low currents. Results show that these membranes undergo an elastic response up to 26 nN on average when compressed with an AFM tip. Measuring the films with a low contact force demonstrates that contact mode AFM can be used repeatedly to image without damaging the film. Based on current-voltage measurements made with the C-AFM, it is shown that apparently high resistances seen for the films could be the result of variable electrical contact between the tip and surface. As a result, the paper proposes that the deflection of the cantilever should always be measured in order to ensure knowledge of the location of the tip during all electrical measurements.
Electronic Structure, Localization and 5f Occupancy in Pu Materials
Authors: Beaux Miles F. , Joyce John J. , Durakiewicz Tomasz , Graham Kevin S. , Bauer Eric D. , Mitchell Jeremy N. , Tobash Paul H. , Richmond Scott
Published: November 2012

The electronic structure of delta plutonium (δ-Pu) and plutonium compounds is investigated using photoelectron spectroscopy (PES). Results for δ-Pu show a small component of the valence electronic structure which might reasonably be associated with a 5f6 configuration. PES results for PuTe are used as an indication for the 5f6 configuration due to the presence of atomic multiplet structure. Temperature dependent PES data on δ-Pu indicate a narrow peak centered 20 meV below the Fermi energy and 100 meV wide. The first PES data for PuCoIn5 indicate a 5f electronic structure more localized than the 5fs in the closely related PuCoGa5. There is support from the PES data for a description of Pu materials with an electronic configuration of 5f5 with some admixture of 5f6 as well as a localized/delocalized 5f5 description.
Alpha-Decay Effects in 241Am-Doped Gadolinium Zirconate
Authors: Stefanovsky S.V. , Ptashkin A.G. , Yudintsev S.V. , Myasoedov B.F.
Published: November 2012

Sample of zirconate ceramic with a composition corresponding to formula Gd1.7241Am0.3Zr2O7 was synthesized by heat-treatment of mechanically activated and compacted in pellet oxide mixture at 1500 °C for 30 min. The d values on XRD pattern of the sample soon after synthesis (D = 7.9×1015 α-decays/g or 0.001 dpa) demonstrated fluorite structure with the most intensive peak with d111 =3.042 Å (a = 5.269 Å) and very weak diffuse reflections due to d-pyrochlore. At a dose of 7.9×1017 α-decays/g or 0.11 dpa the reflections were broadened by approximately 20% and their relative intensity slightly reduced. At higher doses all the weak superstructure reflections disappeared and the growth in intensity and narrowing of the main reflection occurred. Lattice parameter a increased with the dose and reached 5.343 Å (d111 = 3.085 Å) at a dose of 4.6×1018 α-decays/g or 0.42 dpa. At a dose of 5.5×1018 α-decays/g or 0.78 dpa positions of reflections were shifted to lower d-spaces (d111 value reduced to 3.071 Å) and the half-width of the major reflection was 67% of initial. For the 241Am-doped Gd-zirconate the structure recovery rate exceeds disordering rate and no amorphization occurred at doses higher than ∼0.2-0.3 dpa.
Adsorption of Atmospheric Gases on Pu Surfaces
Authors: Nelson A.J. , Holliday K.S. , Stanford J.A. , Grant W.K. , Erler R.G. , Allen P. , McLean W. , Roussel P.
Published: November 2012

Surface adsorption represents a competition between collision and scattering processes that depend on surface energy, surface structure and temperature. The surface reactivity of the actinides can add additional complexity due to radiological dissociation of the gas and electronic structure. Here we elucidate the chemical bonding of gas molecules adsorbed on Pu metal and oxide surfaces. Atmospheric gas reactions were studied at 190 and 300 K using x-ray photoelectron spectroscopy. Evolution of the Pu 4f and O 1s core-level states were studied as a function of gas dose rates to generate a set of Langmuir isotherms. Results show that the initial gas dose forms Pu2O3 on the Pu metal surface followed by the formation of PuO2 resulting in a layered oxide structure. This work represents the first steps in determining the activation energy for adsorption of various atmospheric gases on Pu.
Melting Temperatures and Thermal Conductivities of Corium Prepared from UO2 and Zircaloy-2
Authors: Kato Masato , Uchida Teppei , Hirooka Shun , Akashi Masatoshi , Komeno Akira , Morimoto Kyoichi
Published: November 2012

Corium which simulates the molten core of a Boiling Water Reactor was prepared as a parameter of Zr content, and melting temperatures and thermal conductivities were measured. The melting temperatures were measured by the thermal arrest method and were 2622 oC, 2509 oC and 2540 oC, respectively, in the specimens of 24.3 at%, 49.0 at% and 73.5 at% Zr content. Thermal conductivities had low values of 2.0-3.5 W/m oC at temperatures of 400 to 1600 oC.
The Influence of Vacuum Annealing on the Nucleation and Growth Kinetics of Uranium Hydride
Authors: Knowles J.P. , Findlay I.M. , Geeson D.A. , Bazley S.G.
Published: November 2012

The reaction kinetics of depleted uranium under constant hydrogen pressure (1 bar) have been measured as a function of reaction temperatures between 65 and 385 °C for as-polished and vacuum annealed samples. Enhanced hydrogen reactivity was observed on samples that underwent vacuum annealing prior to hydrogen exposure. The enhanced reactivity was found to be the result of enhanced nucleation rates on annealed samples since the specific rate per reacting unit area remained unaffected. X-ray photoelectron spectroscopy demonstrates that the nucleation kinetics were promoted on annealed samples as a result of the dehydration and partial reduction of the UO2+x outer oxide layer and the formation of an oxycarbide (UOxCy) sub-layer.
A spatial view of the flow of force in masonry bridges
Authors: Harvey Bill
Published: November 2012

Owners need to be able to determine, with some certainty, which of their bridges are at risk of damage by loading and which are not. The underlying rules of distribution encapsulated in current assessment codes for arch bridges are not capable of yielding useful results. It is not, therefore, possible to distinguish effectively between those bridges which have an indefinite life and those which will fail in the near future if loads are increased. Experience suggests that short-span bridges with shallow fill are most at risk and increasing either span or fill depth reduces the risk dramatically. A useful model must be capable of following this trend. The paper presents evidence of failure under live load, a proposal for a new (still relatively simple) model for distribution and a link between that simple model and results from tests and analysis.
Lateral stiffness of hybrid foundations: field investigations and 3D FEM analysis
Authors: TROJNAR K.
Published: November 2012

The paper presents stability problems of horizontally loaded pile–soil interaction in the three-dimensional (3D) state of strain. The results obtained are based on full-scale tests and numerical 3D finite-element method analyses including an evaluation of the interaction between the soil and a pile with a cantilever plate. The research and analyses carried out resulted in a better specification of the current methods calculation for a single pile with cap. An analysis of the 3D pile–soil interaction enabled development of the basis for a more precise determination of the lateral stiffness of a pile with cap in cohesionless soil. A better understanding of the problem is of vital importance for designing bridge abutments, retaining walls founded on single rows of piles, foundations supporting structures, and offshore wind turbines subjected to large lateral loads.
Design and construction of Shoreditch High Street Bridge, UK
Authors: Allen Martin
Published: November 2012

The £500 million East London railway works contract in the UK includes the design and construction of a series of underline bridge structures, carrying the upgraded and extended railway between the refurbished Kingsland viaduct at its northern end and the former Great Eastern railway. One of these is Shoreditch High Street Bridge, a bowstring arch bridge forming a landmark where a new section of the railway crosses Shoreditch High Street just north-east of the City of London. It is an unusual form of railway bridge, chosen primarily for its appearance, having solid round bar hangers and no bracing between arch ribs above deck level. The East London railway Balfour Beatty–Carillion joint venture directed the design and constructed the bridge, while the bridge design was undertaken by URS. This paper describes the design and construction of Shoreditch High Street Bridge, highlighting some of the more unusual features.
The Upregulation of Transglutaminase‐2 by Cyclosporin A in Human Gingival Fibroblasts Is Augmented by Oxidative Stress
Authors: Lee Shiuan‐Shinn , Tsai Chung‐Hung , Kuan Yu‐Hsiang , Huang Fu‐Mei , Chang Yu‐Chao
Published: November 2012

Background: Transglutaminase‐2 (TGM‐2) has been implicated in several fibrotic disorders and can be induced by reactive oxygen species (ROS). Hence, the authors hypothesize that cyclosporin A (CsA) may regulate TGM‐2 via ROS, and this regulation may have a role in the pathogenesis of CsA‐induced gingival overgrowth.

Methods: Cytotoxicity, 2′,7′‐dichlorodihydrofluorescein diacetate assay, and Western blot were used to investigate the effects of CsA in human gingival fibroblasts (HGFs). In addition, extracellular signal‐regulated kinase (ERK) inhibitor PD98059, phosphatidylinositol 3‐kinase inhibitor LY294002, glutathione precursor N‐acetyl‐L‐cysteine (NAC), curcumin, epigallocatechin‐3 gallate (EGCG), and p38 inhibitor SB203580 were added to find the possible regulatory mechanisms.

Results: Concentrations of CsA >500 ng/mL demonstrated cytotoxicity to HGFs (P < 0.05). CsA enhanced the generation of intracellular ROS at concentrations >200 ng/mL (P <0.05). TGM‐2 protein induced by CsA was found in HGFs in a dose‐ and time‐dependent manner (P <0.05). The addition of PD98059, LY294002, NAC, curcumin, EGCG, and SB203580 markedly inhibited TGM‐2 expression induced by CsA (P <0.05).

Conclusions: These results demonstrate that CsA significantly upregulates intracellular ROS generation and elevates TGM‐2 expression in HGFs. In addition, TGM‐2 induced by CsA is downregulated by PD98059, LY294002, NAC, curcumin, EGCG, and SB203580.
Dose and Time Dependence of Targeted and Untargeted Effects after Very Low doses of α-Particle Irradiation of Human Lung Cancer Cells
Authors: Belchior A. , Gil O. Monteiro , Almeida P. , Vaz P.
Published: November 2012

Understanding the effects to human health resulting from exposure to low doses of ionizing radiation is a persisting challenge. No one questions the deleterious consequences for humans following exposure to high radiation doses; however, in the low dose range, the complex and to some extent unknown cellular responses raise important misgivings about the resulting protective or potentially detrimental effects. Bystander effects are involved in low dose exposures, being characterized by the appearance in unirradiated cells of a cellular damage associated with direct radiation exposure. The purpose of our work was to assess, by using clonogenic and micronuclei assays, the dose and time dependence of the bystander response after cells exposure to very low doses of α-particles and to evaluate its importance in the overall induced damage. The study includes an irradiated cells culture, a medium transfer culture with non-irradiated cells and a culture with irradiated cells after centrifugation. We observed a non-negligible contribution of the bystander effects in the overall cellular damage. Low-dose hyper-sensitivity was observed for medium transfer and irradiated cells after centrifugation cultures. Delayed and earlier cellular damage were similar in almost all experiments, suggesting an effectiveness of irradiated medium to induce a bystander response soon after irradiation.
Low-Dose Gamma-Radiation Inhibits Benzo[a]pyrene-Induced Lung Adenoma Development in A/J Mice
Authors: Bruce Veronica R. , Belinsky Steven A. , Gott Katherine , Liu Yushi , March Thomas , Scott Bobby , Wilder Julie
Published: November 2012

Low-dose ionizing radiation (LDR) may lead to suppression of smoking-related lung cancer. We examined the effects of a known cigarette smoke carcinogen Benzo[a]pyrene (B[a]P) alone or in combination with fractionated low-dose gamma radiation (60 – 600 mGy total dose) on the induction of lung neoplasms in the A/J mouse. Our results show that 600 mGy of gamma radiation delivered in six biweekly fractions of 100 mGy starting 1 month after B[a]P injection significantly inhibits the development of lung adenomas per animal induced by B[a]P. Our data also indicated that the six biweekly doses suppressed the occurrence of spontaneous hyperplastic foci in the lung, although this suppression failed to reach statistical significance when analyzed as average foci per lung possibly related to the small sample sizes used for the control and test groups.
Ongoing measures to enhance the efficiency of prescribing of proton pump inhibitors and statins in The Netherlands: influence and future implications
Authors: Woerkom Menno van , Piepenbrink Hans , Godman Brian , Metz Joost de , Campbell Stephen , Bennie Marion , Eimers Marietta , Gustafsson Lars L
Published: November 2012

Background:
Multiple reforms have recently been introduced in The Netherlands to improve prescribing efficiency. These include preference pricing policies for multiple sourced products, guidelines, and quality and efficiency targets, as well as regular pharmacotherapy meetings.
Objectives:
Assess the influence of these multiple measures on prescribing efficiency.
Methods:
Retrospective observational study of all reimbursed prescriptions for proton pump inhibitors and statins between 2000 and 2010 using the Genees-en hulpmiddelen Informatie Project (Health Insurance) database. Utilization measured in defined daily doses. Narrative review of reforms.
Results:
Reimbursed expenditure for the proton pump inhibitors fell by 58% in 2010 versus 2000 despite a threefold increase in utilization, helped by increasing utilization of generic omeprazole at only 2% of the prepatent loss price in 2010. Similarly, reimbursed expenditure for the statins fell by 14% in 2010 versus 2000 despite a 3.8-fold increase in utilization. Again, this was helped by increasing utilization of generic simvastatin at only 2% of the prepatent loss originator price.
Conclusion:
Multiple supply and demand measures, including the preference pricing policy, appear to have appreciably enhanced proton pump inhibitor and statin prescribing efficiency, providing examples to other countries.
Anti-VEGF therapies for the treatment of age-related macular degeneration
Authors: Gower Emily W
Published: November 2012

Evaluation of: Martin DF, Maguire MG, Fine SL
et al.
Ranibizumab and bevacizumab for treatment of neovascular age-related macular degeneration two-year results.
Ophthalmology
119(7), 1388–1398 (2012).

Age-related macular degeneration is the leading cause of blindness in European-derived populations. Recently, drugs have been developed that not only reduce the risk of vision loss, but can actually improve visual acuity. This article provides a summary of a recent comparative effectiveness trial evaluating two of these drugs. The study found that visual acuity outcomes were similar for the two drugs and that monthly dosing provided a slight advantage over as-needed treatment. The role of long-term differences in retinal thickening, geographic atrophy and potential differences in serious adverse events between the two drugs need further research.
The utilization of telephone follow-up in the advanced cancer population: a review of the literature
Authors: Zhou Michelle , Holden Lori , Bedard Gillian , Zeng Liang , Lam Henry , Chu Dominic , Lao Nicholas , Lauzon Natalie , Chow Edward
Published: November 2012

Background:
Palliative cancer patients often require clinic or hospital follow-up after any treatment intervention they may have received. This is typically done in person at either a hospital or a clinic. In these advanced cancer patients, this may be burdensome and result in attrition. Telephone follow-up is becoming more frequently used as an adjunct to clinical follow-up. It can be conducted for both clinical trials, as well as interventional purposes. The purpose of this study was to review the literature and examine the utility and effectiveness of telephone follow-up in the advanced cancer population.
Methods:
A literature search was conducted on Medline (1980 – April week 4 2012), Embase (1980 – week 17 2012), the Cochrane Central Register of Controlled Trials (April 2012) and CINAHL (1981–July 31 2012).
Results:
A total of 11 studies were identified that were published between 2001 and 2011. All studies were in the clinical trial setting. Studies that utilized telephone follow-up in the advanced cancer population, as well as studies that compared the feasibility of telephone follow-up with hospital follow-up, were included in this review. Follow-up at week 4 (month 1) was the most common interval for patient contact. Information collected during the contact varied with the study; however, the most commonly used tool was the Edmonton Symptom Assessment System. Other information included analgesic diary, patient feedback, satisfaction with the care and post-treatment side effects, along with a variety of quality of life questionnaires. Some studies provided information to the patient about protocols for care, advice and coping strategies. Attrition was common even with the use of telephone contact in place of clinical follow-up.
Conclusion:
Telephone follow-up is a feasible alternative to traditional hospital follow-ups for assessment of symptom palliation. There are fewer burdens on the patient, allowing for a better maintenance of quality of life and lower rates of attrition in clinical trials. Patients had an overall positive opinion of the use of this alternative approach with no common disadvantages. A combination of follow-up strategies, such as clinic follow-up and telephone contact for those not attending, may result in a more comprehensive assessment.
Comparison of venous sampling methods for thromboelastography in clinically normal dogs
Authors: Walker Julie M. , Hanel Rita M. , Hansen Bernard D. , Motsinger-Reif Alison A.
Published: November 2012

Objective—To evaluate effects of blood collection method and site on results of thromboelastography in healthy dogs.

Animals—8 clinically normal purpose-bred dogs.

Procedures—Blood was collected from the external jugular vein by syringe aspiration via direct venipuncture with a 20-gauge needle, through a central venous catheter, or into an evacuated tube with a 21-gauge winged needle catheter. Blood was collected from the lateral saphenous vein by syringe aspiration via direct venipuncture with a 20-gauge needle or into an evacuated tube with a 21-gauge winged needle catheter. Kaolin-activated thromboelastographic analyses were performed, and R (reaction time), K (clot formation time), α angle, maximal amplitude, and G (global clot strength) were analyzed.

Results—No significant differences were observed with regard to sampling site. Sample collection method had no effect on thromboelastographic results for saphenous vein samples. Blood samples collected from the jugular vein by syringe aspiration had a lower R and K and higher α angle than did blood samples collected from the jugular vein by evacuated tube collection. Significant differences were observed between blood samples collected from the jugular vein by syringe aspiration and samples collected from the saphenous vein by evacuated tube collection and between samples collected from the saphenous vein by evacuated tube collection and samples collected from the jugular vein through a central venous catheter.

Conclusions and Clinical Relevance—Different sampling methods resulted in small but significant differences in thromboelastographic values. Results justify the use of standardized techniques for research purposes, but all of these sampling methods were acceptable for 1-time clinical use.
Effect of trotting speed and circle radius on movement symmetry in horses during lunging on a soft surface
Authors: Pfau Thilo , Stubbs Narelle C. , Kaiser LeeAnn J. , Brown Lucy E. A. , Clayton Hilary M.
Published: November 2012

Objective—To determine whether body lean angle could be predicted from circle radius and speed in horses during lunging and whether an increase in that angle would decrease the degree of movement symmetry (MS).

Animals—11 medium- to high-level dressage horses in competition training.

Procedures—Body lean angle, head MS, and trunk MS were quantified during trotting while horses were instrumented with a 5-sensor global positioning system–enhanced inertial sensor system and lunged on a soft surface. Speed and circle radius were varied and used to calculate predicted body lean angle. Agreement between observed and predicted values was assessed, and the association between lean angle and MS was determined via least squares linear regression.

Results—162 trials totaling 3,368 strides (mean, 21 strides/trial) representing trotting speeds of 1.5 to 4.7 m/s and circle radii of 1.8 to 11.2 m were conducted in both lunging directions. Differences between observed and predicted lean angles were small (mean ± SD difference, −1.2 ± 2.4°) but significantly greater for circling to the right versus left. Movement symmetry values had a larger spread for the head than for the pelvis, and values of all but 1 MS variable changed with body lean angle.

Conclusions and Clinical Relevance—Body lean angle agreed well with predictions from gravitational and centripetal forces, but differences observed between lunging directions emphasize the need to investigate other factors that might influence this variable. For a fair comparison of MS between directions, body lean angle needs to be controlled for or corrected with the regression equations. Whether the regression equations need to be adapted for lame horses requires additional investigation.
Serum calprotectin concentrations in dogs with idiopathic inflammatory bowel disease
Authors: Heilmann Romy M. , Jergens Albert E. , Ackermann Mark R. , Barr James W. , Suchodolski Jan S. , Steiner Jörg M.
Published: November 2012

Objective—To measure serum calprotectin concentration in dogs with inflammatory bowel disease (IBD) before and after initiation of treatment and evaluate its correlation with a clinical scoring system (canine IBD activity index), serum canine C-reactive protein concentration, and severity of histopathologic changes.

Animals—34 dogs with idiopathic IBD and 139 healthy control dogs.

Procedures—From dogs with IBD, blood samples were collected immediately before (baseline) and 3 weeks after initiation of 1 of 2 treatments: prednisone (1 mg/kg, PO, q 12 h; n = 21) or a combination of prednisone and metronidazole (10 mg/kg, PO, q 12 h; 13). Blood samples were collected once from each of the control dogs. For all samples, serum calprotectin concentration was determined via radioimmunoassay.

Results—Mean serum calprotectin concentrations for dogs with IBD at baseline (431.1 μg/L) and 3 weeks after initiation of treatment (676.9 μg/L) were significantly higher, compared with that (219.4 μg/L) for control dogs, and were not significantly correlated with the canine IBD activity index, serum C-reactive protein concentration, or severity of histopathologic changes. The use of a serum calprotectin concentration of ≥ 296.0 μg/L as a cutoff had a sensitivity of 82.4% (95% confidence interval, 65.5% to 93.2%) and specificity of 68.4% (95% confidence interval, 59.9% to 76.0%) for distinguishing dogs with idiopathic IBD from healthy dogs.

Conclusions and Clinical Relevance—Serum calprotectin concentration may be a useful biomarker for the detection of inflammation in dogs, but the use of certain drugs (eg, glucocorticoids) appears to limit its clinical usefulness.
In vitro effect of hydroxyethyl starch 130/0.42 on canine platelet function
Authors: Classen Janine , Adamik Katja N. , Weber Karin , Rubenbauer Stephanie , Hartmann Katrin
Published: November 2012

Objective—To evaluate the effect of 6% hydroxyethyl starch (HES) solution, with a molecular weight of 130 kDa and a degree of substitution of 0.42, on canine platelet function in vitro.

Samples—Blood samples from 31 healthy adult dogs.

Procedures—Citrated blood was diluted with saline (0.9% NaCl) solution or HES 130/0.42 in ratios of 1:9 (ie, 1 part saline solution or HES 130/0.42 and 9 parts blood) and 1:3. Platelet plug formation time (closure time [Ct]) was measured with a platelet function analyzer and cartridges coated with collagen and ADP.

Results—Median baseline Ct with citrated blood was 84.0 seconds (interquartile range, 74.5 to 99.5 seconds). Results obtained with 1:9 dilutions with saline solution and HES 130/0.42 were not significantly different from baseline results. The 1:3 dilutions with saline solution and HES 130/0.42 resulted in median Cts of 96.0 seconds (interquartile range, 85.5 to 110.8 seconds) and 112.0 seconds (92.0 to 126.0 seconds), respectively. Results obtained with both 1:3 dilutions were significantly different from baseline results. The Ct obtained with the HES dilution was also significantly different from that of the 1:3 dilution with saline solution.

Conclusions and Clinical Relevance—Saline solution and HES 130/0.42 in a 1:3 dilution affected canine platelet function by prolonging Cts. The HES 130/0.42 had a significantly greater effect on canine platelets than did saline solution.
Magnetic resonance imaging of the brain and skull of sheep with cerebral coenurosis
Authors: Manunta Maria L. , Evangelisti Maria A. , Burrai Giovanni P. , Columbano Nicolò , Ligios Ciriaco , Varcasia Antonio , Scala Antonio , Sanna Passino Eraldo
Published: November 2012

Objective—To determine MRI characteristics of the skulls and brains of sheep with chronic cerebral coenurosis (CC) caused by naturally acquired Taenia multiceps infection.

Animals—33 sheep with CC and 10 healthy control sheep.

Procedures—Sheep underwent MRI of the head. Volumes of the cranial cavity and rostral and caudal fossas of the cranial cavity were determined. For CC-affected sheep, the number, location, and volume of T multiceps cysts were determined and the percentage volumes of cysts in the cranial cavity and rostral and caudal fossas of the cranial cavity were calculated. Focal and diffuse abnormalities of cranial bones in CC-affected sheep were identified. Brain edema and hemorrhage and signs of increased cranial pressure (ICP) in MRI images were determined.

Results—Volumes of the cranial cavity and rostral and caudal fossas of the cranial cavity were significantly larger for CC-affected sheep versus healthy control sheep. Total volumes of cysts ranged from 4.40% to 46.93% in cranial cavities of sheep, 4.12% to 51.53% in rostral fossas of cranial cavities of sheep, and 15.24% to 68.30% in caudal fossas of cranial cavities of sheep. Moderate to severe diffuse cranial bone abnormalities and signs of increased ICP in MRI images were detected in 21 and 24 sheep, respectively, and were positively correlated with cyst volumes.

Conclusions and Clinical Relevance—Results suggested that cranial cavity volume and morphological abnormalities can be detected in sheep with CC. These changes may reflect abnormalities in ossification of the cranial bones secondary to chronically increased ICP caused by development of T multiceps cysts.