bluuebunny/crossref_metadata_2025 huggingface dataset:
Modification of vortex dynamics and transport properties of transitional axisymmetric jets using zero-net-mass-flux actuation
Authors: Önder Asim , Meyers Johan
Published: July 2014

We study the near field of a zero-net-mass-flux (ZNMF) actuated round jet using direct numerical simulations. The Reynolds number of the jet ReD = 2000 and three ZNMF actuators are used, evenly distributed over a circle, and directed towards the main jet. The actuators are triggered in phase, and have a relatively low momentum coefficient of Cμ = 0.0049 each. We study four different control frequencies with Strouhal numbers ranging from StD = 0.165 to StD = 1.32; next to that, also two uncontrolled baseline cases are included in the study. We find that this type of ZNMF actuation leads to strong deformations of the near-field jet region that are very similar to those observed for non-circular jets. At the end of the jet's potential core (x/D = 5), the jet-column cross section is deformed into a hexagram-like geometry that results from strong modifications of the vortex structures. Two mechanisms lead to these modifications, i.e., (i) self-deformation of the jet's primary vortex rings started by distortions in their azimuthal curvature by the actuation, and (ii) production of side jets by the development and subsequent detachment of secondary streamwise vortex pairs. Further downstream (x/D = 10), the jet transforms into a triangular pattern, as the sharp corner regions of the hexagram entrain fluid and spread. We further investigate the global characteristics of the actuated jets. In particular when using the jet preferred frequency, i.e., StD = 0.33, parameters such as entrainment, centerline decay rate, and mean turbulent kinetic energy are significantly increased. Furthermore, high frequency actuation, i.e., StD = 1.32, is found to suppress the mechanisms leading to large scale structure growth and turbulent kinetic energy production. The simulations further include a passive scalar equation, and passive scalar mixing is also quantified and visualized.
Exact dynamical coarse-graining without time-scale separation
Authors: Lu Jianfeng , Vanden-Eijnden Eric
Published: July 2014

A family of collective variables is proposed to perform exact dynamical coarse-graining even in systems without time scale separation. More precisely, it is shown that these variables are not slow in general, yet satisfy an overdamped Langevin equation that statistically preserves the sequence in which any regions in collective variable space are visited and permits to calculate exactly the mean first passage times from any such region to another. The role of the free energy and diffusion coefficient in this overdamped Langevin equation is discussed, along with the way they transform under any change of variable in collective variable space. These results apply both to systems with and without inertia, and they can be generalized to using several collective variables simultaneously. The view they offer on what makes collective variables and reaction coordinates optimal breaks from the standard notion that good collective variable must be slow variable, and it suggests new ways to interpret data from molecular dynamics simulations and experiments.
Accelerated weight histogram method for exploring free energy landscapes
Authors: Lindahl V. , Lidmar J. , Hess B.
Published: July 2014

Calculating free energies is an important and notoriously difficult task for molecular simulations. The rapid increase in computational power has made it possible to probe increasingly complex systems, yet extracting accurate free energies from these simulations remains a major challenge. Fully exploring the free energy landscape of, say, a biological macromolecule typically requires sampling large conformational changes and slow transitions. Often, the only feasible way to study such a system is to simulate it using an enhanced sampling method. The accelerated weight histogram (AWH) method is a new, efficient extended ensemble sampling technique which adaptively biases the simulation to promote exploration of the free energy landscape. The AWH method uses a probability weight histogram which allows for efficient free energy updates and results in an easy discretization procedure. A major advantage of the method is its general formulation, making it a powerful platform for developing further extensions and analyzing its relation to already existing methods. Here, we demonstrate its efficiency and general applicability by calculating the potential of mean force along a reaction coordinate for both a single dimension and multiple dimensions. We make use of a non-uniform, free energy dependent target distribution in reaction coordinate space so that computational efforts are not wasted on physically irrelevant regions. We present numerical results for molecular dynamics simulations of lithium acetate in solution and chignolin, a 10-residue long peptide that folds into a β-hairpin. We further present practical guidelines for setting up and running an AWH simulation.
Comparative study of characteristics of water-ethanol binary mixture nanofluids for heat pipe efficiency enhancement
Authors: Park Sung Seek , Kim Nam Jin
Published: July 2014

A nanofluid is a fluid containing suspended solid particles, with sizes on the order of nanometers. Normally, nanofluids have higher thermal conductivities than their base fluids. Therefore, we manufactured binary nanofluids by adding multi-walled carbon nanotubes to water-ethanol (ethanol concentration is 0.2) binary mixture nanofluids for efficiency improvement of a heat pipe. And we measured the thermal conductivity and viscosity of water-ethanol binary mixture nanofluids. The thermal conductivity and viscosity of binary nanofluids were measured by using transient hot-wire method and rotational digital viscometer, respectively. As a result, at the same volumetric ratio and temperature, the water-ethanol binary mixture nanofluids offer a lower rate of viscosity increase and a higher rate of thermal conductivity increase than distilled-water-based nanofluids. Therefore, nanofluids, formulated based on binary fluids mixed to the proper ratio, offer excellent performance that is clearly superior to that of single-component-based nanofluids.
An atomic charge model for graphene oxide for exploring its bioadhesive properties in explicit water
Authors: Stauffer D. , Dragneva N. , Floriano W. B. , Mawhinney R. C. , Fanchini G. , French S. , Rubel O.
Published: July 2014

Graphene Oxide (GO) has been shown to exhibit properties that are useful in applications such as biomedical imaging, biological sensors, and drug delivery. The binding properties of biomolecules at the surface of GO can provide insight into the potential biocompatibility of GO. Here we assess the intrinsic affinity of amino acids to GO by simulating their adsorption onto a GO surface. The simulation is done using Amber03 force-field molecular dynamics in explicit water. The emphasis is placed on developing an atomic charge model for GO. The adsorption energies are computed using atomic charges obtained from an ab initio electrostatic potential based method. The charges reported here are suitable for simulating peptide adsorption to GO.
Langmuir probe diagnostic suite in the C-2 field-reversed configuration
Authors: Roche T. , Sun X. , Armstrong S. , Knapp K. , Slepchenkov M.
Published: July 2014

Several in situ probes have been designed and implemented into the diagnostic array of the C-2 field-reversed configuration (FRC) at Tri Alpha Energy [M. Tuszewski et al. (the TAE Team), Phys. Rev. Lett. 108, 255008 (2012)]. The probes are all variations on the traditional Langmuir probe. They include linear arrays of triple probes, linear arrays of single-tipped swept probes, a multi-faced Gundestrup probe, and an ion-sensitive probe. The probes vary from 5 to 7 mm diameter in size to minimize plasma perturbations. They also have boron nitride outer casings that prevent unwanted electrical breakdown and reduce the introduction of impurities. The probes are mounted on motorized linear-actuators allowing for programmatic scans of the various plasma parameters over the course of several shots. Each probe has a custom set of electronics that allows for measurement of the desired signals. High frequency ( > 5MHz) analog optical-isolators ensure that plasma parameters can be measured at sub-microsecond time scales while providing electrical isolation between machine and data acquisition systems. With these probes time-resolved plasma parameters (temperature, density, spatial potential, flow, and electric field) can be directly/locally measured in the FRC jet and edge/scrape-off layer.
Asymmetric recombination and electron spin relaxation in the semiclassical theory of radical pair reactions
Authors: Lewis Alan M. , Manolopoulos David E. , Hore P. J.
Published: July 2014

We describe how the semiclassical theory of radical pair recombination reactions recently introduced by two of us [D. E. Manolopoulos and P. J. Hore, J. Chem. Phys. 139, 124106 (2013)] can be generalised to allow for different singlet and triplet recombination rates. This is a non-trivial generalisation because when the recombination rates are different the recombination process is dynamically coupled to the coherent electron spin dynamics of the radical pair. Furthermore, because the recombination operator is a two-electron operator, it is no longer sufficient simply to consider the two electrons as classical vectors: one has to consider the complete set of 16 two-electron spin operators as independent classical variables. The resulting semiclassical theory is first validated by comparison with exact quantum mechanical results for a model radical pair containing 12 nuclear spins. It is then used to shed light on the spin dynamics of a carotenoid-porphyrin-fullerene triad containing considerably more nuclear spins which has recently been used to establish a “proof of principle” for the operation of a chemical compass [K. Maeda, K. B. Henbest, F. Cintolesi, I. Kuprov, C. T. Rodgers, P. A. Liddell, D. Gust, C. R. Timmel, and P. J. Hore, Nature (London) 453, 387 (2008)]. We find in particular that the intriguing biphasic behaviour that has been observed in the effect of an Earth-strength magnetic field on the time-dependent survival probability of the photo-excited C·+PF·− radical pair arises from a delicate balance between its asymmetric recombination and the relaxation of the electron spin in the carotenoid radical.
Origins of effective resistivity in collisionless magnetic reconnection
Authors: Singh Nagendra
Published: July 2014

The mechanisms that provide effective resistivity for supporting collisonless magnetic reconnection have remained unsettled despite numerous studies. Some of these studies demonstrated that the electron pressure nongyrotropy generates the resistivity (ηnpg) in the electron diffusion region (EDR). We derive an analytical relation for the effective resistivity (ηkin) by momentum balance in a control volume in the EDR. Both ηnpg and ηkin mutually compare well and they also compare well with the resistivity required to support reconnection electric field Erec in multi-dimensional particle-in-cell simulations as well as in satellite observations when reconnection occurs in an EDR. But they are about an order of magnitude or so smaller than that required when the reconnection occurred in a much wider reconnecting current sheet (RCS) of half width (w) of the order of the ion skin depth (di), observed in the Earth magnetosphere. The chaos-induced resistivity reported in the literature is found to be even more deficient. We find that for reconnection in RCS with w ∼ di, anomalous diffusion, such as the universal Bhom diffusion and/or that arising from kinetic Alfven waves, could fairly well account for the required resistivity.
Presence of a monoclinic (Pm) phase in the morphotropic phase boundary region of multiferroic (1 − x)Bi(Ni1/2Ti1/2)O3-xPbTiO3 solid solution: A Rietveld study
Authors: Pandey Rishikesh , Singh Akhilesh Kumar
Published: July 2014

We present here the results of structural studies on multiferroic (1 − x)Bi(Ni1/2Ti1/2)O3-xPbTiO3 solid solution using Rietveld analysis on powder x-ray diffraction data in the composition range 0.35 ≤ x ≤ 0.55. The stability region of various crystallographic phases at room temperature for (1 − x)Bi(Ni1/2Ti1/2)O3-xPbTiO3 is determined precisely. Structural transformation from pseudo-cubic (x ≤ 0.40) to tetragonal (x ≥ 0.50) phase is observed via phase coexistence region demarcating the morphotropic phase boundary. The morphotropic phase boundary region consists of coexisting tetragonal and monoclinic structures with space group P4mm and Pm, respectively, stable in composition range 0.41 ≤ x ≤ 0.49 as confirmed by Rietveld analysis. The results of Rietveld analysis completely rule out the coexistence of rhombohedral and tetragonal phases in the morphotropic phase boundary region reported by earlier workers. A comparison between the bond lengths for “B-site cations-oxygen anions” obtained after Rietveld refinement, with the bond length calculated using Shannon-Prewitt ionic radii, reveals the ionic nature of B-O (Ni/Ti-O) bonds for the cubic phase and partial covalent character for the other crystallographic phases.
Piezoelectric energy harvesting from traffic-induced pavement vibrations
Authors: Jiang Xuezheng , Li Yancheng , Li Jianchun , Wang Jiong , Yao Jin
Published: July 2014

This paper focuses on the development and experimental testing of a potential clean energy source for powering the remote equipment used in transportation infrastructure. Traditional power sources (i.e., power cables and batteries) are excessively expensive or infeasible in this type of application. A compression-based roadway energy harvester has been developed that can be embedded into pavement to scavenge electrical energy from traffic-induced vibrations. The proposed roadway harvester employs a group of piezoelectric harvesting units to convert traffic-induced vibrations into electrical energy, and each single harvesting unit contains three piezoelectric multilayer stacks. According to the linear theory of piezoelasticity, a two-degree-of-freedom electromechanical model of the piezoelectric harvesting unit was developed to characterize its performance in generating electrical energy under external excitations. Experimental testing in the laboratory was conducted to investigate the output power properties of the harvesting unit and shows good agreement with the theoretical analysis. Based on the testing results of the harvesting unit, the capability of the proposed roadway harvester has been theoretically evaluated and demonstrated that it has the ability to generate sufficient energy for driving common electrical equipment used in transportation infrastructure.
Cell force mapping using a double-sided micropillar array based on the moiré fringe method
Authors: Zhang F. , Anderson S. , Zheng X. , Roberts E. , Qiu Y. , Liao R. , Zhang X.
Published: July 2014

The mapping of traction forces is crucial to understanding the means by which cells regulate their behavior and physiological function to adapt to and communicate with their local microenvironment. To this end, polymeric micropillar arrays have been used for measuring cell traction force. However, the small scale of the micropillar deflections induced by cell traction forces results in highly inefficient force analyses using conventional optical approaches; in many cases, cell forces may be below the limits of detection achieved using conventional microscopy. To address these limitations, the moiré phenomenon has been leveraged as a visualization tool for cell force mapping due to its inherent magnification effect and capacity for whole-field force measurements. This Letter reports an optomechanical cell force sensor, namely, a double-sided micropillar array (DMPA) made of poly(dimethylsiloxane), on which one side is employed to support cultured living cells while the opposing side serves as a reference pattern for generating moiré patterns. The distance between the two sides, which is a crucial parameter influencing moiré pattern contrast, is predetermined during fabrication using theoretical calculations based on the Talbot effect that aim to optimize contrast. Herein, double-sided micropillar arrays were validated by mapping mouse embryo fibroblast contraction forces and the resulting force maps compared to conventional microscopy image analyses as the reference standard. The DMPA-based approach precludes the requirement for aligning two independent periodic substrates, improves moiré contrast, and enables efficient moiré pattern generation. Furthermore, the double-sided structure readily allows for the integration of moiré-based cell force mapping into microfabricated cell culture environments or lab-on-a-chip devices.
Note: Design and investigation of a multichannel plasma-jet triggered gas switch
Authors: Tie Weihao , Liu Xuandong , Zhang Qiaogen , Liu Shanhong
Published: July 2014

We described the fabrication and testing of a multichannel plasma-jet triggered gas switch (MPJTGS). A novel six-channel annular micro-plasma-gun was embedded in the trigger electrode to generate multichannel plasma jets as a nanosecond trigger pulse arrived. The gas breakdown in multiple sites of the spark gap was induced and fixed around jet orifices by the plasma jets. We tested the multichannel discharge characteristics of the MPJTGS in two working modes with charge voltage of 50 kV, trigger voltage of +40 kV (25 ns rise time), and trigger energy of 240 J, 32 J, and 2 J, respectively, at different working coefficients. Results show that the average number of discharge channels increased as the trigger energy increased, and decreased as the working coefficient decreased. At a working coefficient of 87.1% and trigger energy of 240 J, the average number of discharge channels in Mode II could reach 4.1.
Macro- and microscopic properties of strontium doped indium oxide
Authors: Nikolaenko Y. M. , Kuzovlev Y. E. , Medvedev Y. V. , Mezin N. I. , Fasel C. , Gurlo A. , Schlicker L. , Bayer T. J. M. , Genenko Y. A.
Published: July 2014

Solid state synthesis and physical mechanisms of electrical conductivity variation in polycrystalline, strontium doped indium oxide In2O3:(SrO)x were investigated for materials with different doping levels at different temperatures (T = 20–300 °C) and ambient atmosphere content including humidity and low pressure. Gas sensing ability of these compounds as well as the sample resistance appeared to increase by 4 and 8 orders of the magnitude, respectively, with the doping level increase from zero up to x = 10%. The conductance variation due to doping is explained by two mechanisms: acceptor-like electrical activity of Sr as a point defect and appearance of an additional phase of SrIn2O4. An unusual property of high level (x = 10%) doped samples is a possibility of extraordinarily large and fast oxygen exchange with ambient atmosphere at not very high temperatures (100–200 °C). This peculiarity is explained by friable structure of crystallite surface. Friable structure provides relatively fast transition of samples from high to low resistive state at the expense of high conductance of the near surface layer of the grains. Microscopic study of the electro-diffusion process at the surface of oxygen deficient samples allowed estimation of the diffusion coefficient of oxygen vacancies in the friable surface layer at room temperature as 3 × 10−13 cm2/s, which is by one order of the magnitude smaller than that known for amorphous indium oxide films.
Communication: Asymmetrical cation movements through G-quadruplex DNA
Authors: Zhu Hong , Xiao Shiyan , Wang Lei , Liang Haojun
Published: July 2014

G-quadruplex is a specific DNA structure stabilized by cations dwelling between adjacent G-quartets. The cation which dwelling in the coordination sites can move to the bulk solution through two terminals of G-quadruplex in an asymmetrical manner. In this study, we used molecular dynamics simulations and adaptive biasing force method to investigate the influence of glycosidic bond orientations of guanosines on the moving of cations through the G-quartet. We found that syn glycosidic bond orientation penalizes the escaping of K+ ions, which results in the asymmetrical cation movements through the two terminals of G-quadruplexes. Nonetheless, the syn orientations have slight influence on the energy barrier for Na+ ions penetrating the terminal G-quartets because of its relatively smaller radius. This study contributes to the understanding of the asymmetrical cation displacement in G-quadruplex systems.
Tunable electronic structures of p-type Mg doping in AlN nanosheet
Authors: Peng Yuting , Xia Congxin , Zhang Heng , Wang Tianxing , Wei Shuyi , Jia Yu
Published: July 2014

The p-type impurity properties are investigated in the Mg-doped AlN nanosheet by means of first-principles calculations. Numerical results show that the transition energy levels reduce monotonously with the increase in Mg doping concentration in the Mg-doped AlN nanosheet systems, and are lower than that of the Mg-doped bulk AlN case for the cases with larger doping concentration. Moreover, Mg substituting Al atom is energy favorably under N-rich growth experimental conditions. These results are new and interesting to further improve p-type doping efficiency in the AlN nanostructures.
Improved efficiency of P3HT:PCBM solar cells by incorporation of silver oxide interfacial layer
Authors: Das Sayantan , Alford T. L.
Published: July 2014

In recent years, a substantial amount of research has been focused on identifying suitable interfacial layers in organic light-emitting diodes and organic solar cells which has efficient charge transport properties. In this work, a very thin layer of AgOx is deposited on top of the ITO layer along with PEDOT:PSS and is observed that the solar cells having the AgOx interfacial layer showed a 28% increase in power conversion efficiency in comparison to that of the control cell. The enhancement in efficiency has been ascribed to improvements in fill factor as well as the increase in shunt resistance and decrease in the series resistance of the solar cells. An equivalent circuit model is also provided to understand the changes in the series and shunt resistances in the AgOx modified devices.
Magnetic dynamics studies of the newest-generation iron deficiency drugs based on ferumoxytol and iron isomaltoside 1000
Authors: Prester M. , Drobac D. , Marohnić Ž.
Published: July 2014

Magnetic dynamics studies by AC susceptibility technique have been performed on the two newest-generation iron deficiency drugs, commercialized under the trade names Feraheme and Monofer. In all aspects, these magnetic nanoparticle systems obey a common pattern of superparamagnetism characterized by similar blocking temperatures, average particle sizes, and magnetocrystalline anisotropy energy. However, effective magnetic moments associated with average particle of each drug are remarkably different, being approximately 10630 μB (Feraheme) and 134 μB (Monofer). The difference relies on qualitatively different magnetic interaction permeating the iron cores of the constituent nanoparticles. The nanoparticle of each system can be classified as monodomain ferrimagnet (Feraheme) and almost compensated antiferromagnet (Monofer). In accordance with different associated moments the dipole-dipole interaction between nanoparticles for the two drugs differs for orders of magnitudes but remains safely small at room temperatures. For reference, the corresponding measurements on previously better investigated iron-sucrose haematinic Venofer has been also performed and included in this article.
Surface donor states distribution post SiN passivation of AlGaN/GaN heterostructures
Authors: Goyal Nitin , Fjeldly Tor A.
Published: July 2014

In this paper, we present a physics based analytical model to describe the effect of SiN passivation on two-dimensional electron gas density and surface barrier height in AlGaN/GaN heterostructures. The model is based on an extraction technique to calculate surface donor density and surface donor level at the SiN/AlGaN interface. The model is in good agreement with the experimental results and promises to become a useful tool in advanced design and characterization of GaN based heterostructures.
Annular nanoplasmonic void arrays as tunable surface enhanced Raman spectroscopy substrates
Authors: Li Zhibo , Clark Alasdair W. , Cooper Jonathan M.
Published: July 2014

We report the use of annular nano-voids in a metallic thin-film as programmable molecular sensors for surface-enhanced Raman spectroscopy (SERS). To date, research into these structures has focused on the exploration of their extraordinary optical transmission attributes. We now show that by using advanced lithography and simulation tools, we can generate a porous SERS material for molecular interrogation. Using ultra-thin annular structures, rather than simple circular holes, allows us to reduce both the volume and cross-sectional area of the void, maximizing the electric-field confinement, while, importantly for SERS, producing resonant conditions in the visible region of the spectrum. By comparing our annular films with conventional circular films with the same resonant frequency, we show a significant improvement in the efficiency of Raman scatter, creating stronger signals that also contain more spectral information.
Observation of the high-sensitivity plasmonic dipolar antibonding mode of gold nanoantennas in evanescent waves
Authors: Chen Yi-Hsun , Chen Kuo-Ping , Shih Min-Hsiung , Chang Che-Yuan
Published: July 2014

Plasmonic dipolar antibonding modes of gold nanoantennas are observed in evanescent waves. Comparing with the bonding mode for normal incidence, the use of prism coupling to transfer the energy of incident light to plasmonic resonance in nanoantennas not only has a higher extinction coefficient but also achieves higher sensitivity to the surrounding environment. The sensitivity of the antibonding mode of gold nanoantenna is 4.84 times that of the bonding mode in terms of the figure of merit.
Electric toroidal metamaterial for resonant transparency and circular cross-polarization conversion
Authors: Guo Lin-Yan , Li Min-Hua , Huang Xiao-Jun , Yang He-Lin
Published: July 2014

Electric toroidal dipolar response has been achieved by metamaterial based on sun-like aperture element at microwave frequency. It is confirmed numerically by scattered powers that the electric toroidal dipolar moment dominates over other moments at the corresponding resonance. This proposed metamaterial exhibits resonant transparency under linearly polarized incidence caused by destructive interference between magnetic dipole and electric toroidal dipole. Notably, it also provides circular cross-polarization conversions between left-handed circularly polarized wave and right-handed circularly polarized wave at the same frequency. These properties associated with elusive electric toroidal dipolar moment offer an avenue for various potential applications in microwave devices.
Ion-Velocity Map Imaging Study of Photodissociation Dynamics of Acetaldehyde
Authors: Zhang Zhi-guo , Chen Zhi-chao , Zhang Cui-mei , Jin Yan-ling , Zhang Qun , Chen Yang , Huang Cun-shun , Yang Xue-ming
Published: July 2014

The photodissociation dynamics of acetaldehyde in the radical channel CH3+HCO has been reinvestigated using time-sliced velocity map imaging technique in the photolysis wavelength range of 275–321 nm. The CH3 fragments have been probed via (2+1) resonance-enhanced multiphoton ionization. Images are measured for CH3 formed in the ground and excited states (v2=0 and 1) of the umbrella vibrational mode. For acetaldehyde dissociation on T1 state after intersystem crossing from S1 state, the products are formed with high translational energy release and low internal excitation. The rotational and vibrational energy of both fragments increases with increasing photodissociation energy. The triplet barrier height is estimated at 3.881±0.006 eV above the ground state of acetaldehyde.
Laser Light Scattering Study on Aggregation of Cellulose Diacetate in Acetone
Authors: Xie Ding-hai , Li Xu-hua , Fang Xi-ling , Ma Chun-feng
Published: July 2014

We have investigated the properties of cellulose diacetate in solution by using laser light scattering. The cellulose diacetate molecules can form micelles and micellar clusters in acetone besides the individual chains. As the concentration increases, the average hydrodynamic radius 〈Rh〉 linearly increases, whereas the ratio of gyration radius to hydrodynamic radius 〈Rg〉/〈Rh〉 linearly decreases. It indicates that the micelles associate and form micellar clusters due to the intermolecular interactions.
Density Functional Theory Study on Raman Spectra of Rhodamine Molecules in Different Forms
Authors: Ma Yong , Hu Wei , Song Xiu-neng , Wang Chuan-kui
Published: July 2014

Rhodamine molecules are one of the most used dyes for applications related to Raman spectroscopy. We have systematically studied Raman spectra of Rhodamine 6G, Rhodamine 123, and Rhodamine B (RhB) molecules using density functional theory. It is found that with BP86 functional the calculated Raman spectra of cationic Rhodamine molecules are in good agreement with corresponding experimental spectra in aqueous solution. It is shown that the involvement of the counter ion, chlorine, and the specific hydrogen bonds has noticeable effects on the Raman spectra of RhB that can partially explain the observed difference between Raman spectra of RhB in solution and on gold surfaces. It also indicates that an accurate description of surface enhanced Raman scattering for Rhodamine molecules on metal surface still requires to take into account the changes induced by the interfacial interactions.
Preparation of Surfactant-Free Pt and PtRu Nanoparticles with High Activity for Methanol Oxidation
Authors: Yao Yao , Cai Jun , Zheng Yong-li , Chen Yan-xia
Published: July 2014

A simple and green approach to synthesize highly active electro-catalysts for methanol oxidation reaction (MOR) without using any organic agents is described. Pt nanoparticles are directly deposited on the pre-cleaned and pre-oxidized multiwall carbon nanotubes (MWC-NTs) from Pt salt by using CO as the reductant. MOR activity has been characterized by both cyclic voltammetry and chronoamperometry, the current density and mass specific current at the peak potential (ca. 0.9 V vs. RHE) reaches 11.6 mA/cm2 and 860 mA/mgPt, respectively. After electro-deposition of Ru onto the Pt/MWCNTs surface, the catalysts show steady state mass specific current of 20 and 80 mA/mgPt at 0.5 and 0.6 V, respectively.
The Rise of Elemental Two-Dimensional Materials Beyond Graphene
Authors: Le Lay Guy , Salomon Eric , De Padova Paola , Layet Jean-Marc , Angot Thierry
Published: July 2014

Following the publication in 2012 of the first compelling evidence of the synthesis of silicene, the silicon based counterpart of graphene, the last two years have seen a surge of articles on elemental, novel two-dimensional materials beyond graphene. Here, research in this burgeoning field is highlighted.
Public perceptions of cancer risk factors: a Western Australian study
Authors: MacTiernan Anna , Fritschi Lin , Slevin Terry , Jalleh Geoffrey , Donovan Rob , Heyworth Jane
Published: July 2014

Issue addressed

People's perceptions of risk may influence health‐related behaviours. The aim of this study was to investigate the perception of cancer risk factors among Western Australian adults in order to inform health promotion policies.

Methods

Cross‐sectional surveys of 2094 adults were undertaken in 2007/2008 in which respondents were asked whether they thought factors increased or decreased the risk of cancer. Factors included both established and unestablished risk factors for cancer. The distribution of perceptions was compared according to age and sex.

Results

The study found high levels of endorsement for some unestablished risk factors (74–91%) and comparatively lower levels of endorsement for many established risk factors (33–80%). The established risk factors of smoking and asbestos received high levels of endorsement (94–98%).

Conclusion

It appears that the alignment between scientifically established risk factors and the Western Australian public's perception of cancer risk factors could be improved.

So what?

Health promotion strategies are needed to improve the public's awareness of cancer risk factors. The high levels of endorsement attributed to unestablished risk factors highlight the need to dispel myths surrounding cancer and to reinforce the key factors in cancer prevention. Ongoing assessment of the alignment between community perceptions of cancer risk and the scientific evidence for cancer risk is important for guiding prioritisation within public health organisations.
Usability and Impact of a Computerized Clinical Decision Support Intervention Designed to Reduce Urinary Catheter Utilization and Catheter-Associated Urinary Tract Infections
Authors: Baillie Charles A. , Epps Mika , Hanish Asaf , Fishman Neil O. , French Benjamin , Umscheid Craig A.
Published: July 2014

Objective

To evaluate the usability and effectiveness of a computerized clinical decision support (CDS) intervention aimed at reducing the duration of urinary tract catheterizations.

Design

Retrospective cohort study.

Setting

Academic healthcare system.

Patients.

All adult patients admitted from March 2009 through May 2012.

Intervention.

A CDS intervention was integrated into a commercial electronic health record. Providers were prompted at order entry to specify the indication for urinary catheter insertion. On the basis of the indication chosen, providers were alerted to reassess the need for the urinary catheter if it was not removed within the recommended time. Three time periods were examined: baseline, after implementation of the first intervention (stock reminder), and after a second iteration (homegrown reminder). The primary endpoint was the usability of the intervention as measured by the proportion of reminders through which providers submitted a remove urinary catheter order. Secondary endpoints were the urinary catheter utilization ratio and the rate of hospital-acquired catheter-associated urinary tract infections (CAUTIs).

Result.

The first intervention displayed limited usability, with 2% of reminders resulting in a remove order. Usability improved to 15% with the revised reminder. The catheter utilization ratio declined over the 3 time periods (0.22, 0.20, and 0.19, respectively; P < .001), as did CAUTIs per 1,000 patient-days (0.84, 0.70, and 0.51, respectively; P < .001).

Conclusions

A urinary catheter removal reminder system was successfully integrated within a healthcare system’s electronic health record. The usability of the reminder was highly dependent on its user interface, with a homegrown version of the reminder resulting in higher impact than a stock reminder.

Infect Control Hosp Epidemiol 2014;35(9):1147-1155
Infection Prevention Practices in Neonatal Intensive Care Units Reporting to the National Healthcare Safety Network
Authors: Hocevar Susan N. , Lessa Fernanda C. , Gallagher Lauren , Conover Craig , Gorwitz Rachel , Iwamoto Martha
Published: July 2014

Background.

Patients in the neonatal intensive care unit (NICU) are at high risk for healthcare-associated infections. Variability in reported infection rates among NICUs exists, possibly related to differences in prevention strategies. A better understanding of current prevention practices may help identify prevention gaps and areas for further research.

Methods

We surveyed infection control staff in NICUs reporting to the National Healthcare Safety Network (NHSN) to assess strategies used to prevent methicillin-resistant Staphylococcus aureus (MRSA) transmission and central line–associated bloodstream infections in NICUs.

Results

Staff from 162 of 342 NICUs responded (response rate, 47.3%). Most (92.3%) NICUs use central line insertion and maintenance bundles, but maintenance practices varied, including agents used for antisepsis and frequency of dressing changes. Forty-two percent reported routine screening for MRSA colonization upon admission for all patients. Chlorhexidine gluconate (CHG) use for central line care for at least 1 indication (central line insertion, dressing changes, or port/cap antisepsis) was reported in 82 NICUs (51.3%). Among sixty-five NICUs responding to questions on CHG use restrictions, 46.2% reported no restrictions.

Conclusions

Our survey illustrated heterogeneity of CLABSI and MRSA prevention practices and underscores the need for further research to define optimal strategies and evidence-based prevention recommendations for neonates.

Infect Control Hosp Epidemiol 2014;35(9):1126-1132
Toric stacks II: Intrinsic characterization of toric stacks
Authors: Geraschenko Anton , Satriano Matthew
Published: July 2014

The purpose of this paper and its prequel is to introduce and develop a theory of toric stacks which encompasses and extends several notions of toric stacks defined in the literature, as well as classical toric varieties.

While the focus of the prequel is on how to work with toric stacks, the focus of this paper is how to show a stack is toric. For toric varieties, a classical result says that a finite type scheme with an action of a dense open torus arises from a fan if and only if it is normal and separated. In the same spirit, the main result of this paper is that any Artin stack with an action of a dense open torus arises from a stacky fan under reasonable hypotheses.
The European Union and its Competition Law and Institutions
Authors: Jones Alison , Sufrin Brenda
Published: July 2014

All books in this flagship series contain carefully selected substantial extracts from key cases, legislation, and academic debate, providing able students with a stand-alone resource. This chapter sketches the history of the EU and its institutions in order to set the competition rules in context. It then discusses the competition provisions themselves, and explains the way in which those rules are applied and enforced. The EU competition rules are primarily contained in Title VII, Chapter 1 of the Treaty on the Functioning of the European Union (TFEU). The two main competition articles are Article 101 TFEU, which applies to agreements between undertakings, and Article 102, which applies to the conduct of undertakings in a ‘dominant position’. Articles 101 and 102 are supplemented by Article 106 (public undertakings and undertakings with special or exclusive rights), and by articles concerned with powers and procedures.
Vertical Agreements
Authors: Jones Alison , Sufrin Brenda
Published: July 2014

All books in this flagship series contain carefully selected substantial extracts from key cases, legislation, and academic debate, providing able students with a stand-alone resource. This chapter, which discusses EU competition policy towards vertical agreements, begins by outlining the choices available to a supplier when deciding how best to market and sell its products or services to customers, and the impact that the competition rules may have on a supplier's choice. It then discusses the EU approach to vertical restraints; the application of Article 101(1) and Article 101(3) to vertical agreements; sub-contracting agreements; and the possible application of Article 102 to distribution agreements.
Licensing Agreements and Other Agreements Involving Intellectual Property Rights
Authors: Jones Alison , Sufrin Brenda
Published: July 2014

All books in this flagship series contain carefully selected substantial extracts from key cases, legislation, and academic debate, providing able students with a stand-alone resource. This chapter examines some of the different types of intellectual property rights (IPRs) before outlining the relationship between intellectual property and both EU competition law and the EU free movement rules. It focuses, however, on IP licensing agreements and their treatment under Article 101. The chapter is organized as follows. Section 3 traces the development of EU competition policy to IP licensing agreements. Sections 4 and 5 examine the current Technology Transfer Block Exemption, Regulation 772/2004 (TTBER) and the Guidelines in detail (noting where significant changes might occur in 2014). Sections 6, 7, and 8 deal with trade mark licences, trade mark delimitation agreements, and copyright (other than software) licences not covered by the TTBER and Guidelines. Section 9 outlines issues arising in cases involving IPRs under Article 102, while Section 10 concludes.
Mergers
Authors: Jones Alison , Sufrin Brenda
Published: July 2014

All books in this flagship series contain carefully selected substantial extracts from key cases, legislation, and academic debate, providing able students with a stand-alone resource. This chapter discusses the following: the purposes of merger control; the history of the European merger control regulation; the scheme of the European merger control regulation; jurisdiction; procedure; substantive appraisal of concentrations under the European Union Merger Regulation (EUMR); EUMR statistics; appeals; and international issues.
International Aspects
Authors: Jones Alison , Sufrin Brenda
Published: July 2014

All books in this flagship series contain carefully selected substantial extracts from key cases, legislation, and academic debate, providing able students with a stand-alone resource. This chapter first examines the question of competition law and extraterritoriality, particularly in relation to the EU and the USA. It then looks at the ‘internationalization’ of competition law and the efforts to deal with competition issues on a global perspective to match the global operations of undertakings on world markets.
Quantifying mesh resistance to opening of netting panels: experimental method, regression models, and parameter estimation strategies
Authors: de la Prada Amelia , González Manuel
Published: July 2014

The increased mesh resistance to opening of netting panels manufactured with thick and stiff twines has a notable impact in the structural response and selective performance of the fishing gears. The only available method to quantify the mesh resistance to opening of netting panels was described in Sala et al. (in Experimental method for quantifying resistance to the opening of netting panels. ICES Journal of Marine Science, 64: 1573–1578, 2007b). We present an alternative method with a similar methodology: we attempt to estimate the mechanical and geometrical properties of a netting material that best fits the experimental measurements of a netting panel. We introduce three major contributions: (i) a considerably simpler uniaxial experimental set-up, which stretches a netting sample in the normal direction of the meshes while leaving free its deformation in the transverse direction; (ii) more accurate theoretical models for mesh resistance to opening; and (iii) new strategies to estimate the parameters of the models. We present the results of the analysis of polyethylene, compacted polyethylene, single-twine, and double-twine netting. Some of the assessed combinations of estimation strategies and theoretical models have an excellent goodness of fit with experimental data. The method proved to be a simple yet accurate way to quantify the mesh resistance to opening of netting panels.
Immunizations
Authors: Issa Nicolas C. , Pisculli Mary L. , Baden Lindsey R.
Published: July 2014

Childhood immunizations are responsible for the control of many infectious diseases once common in the United States including polio, measles, mumps, rubella, diphtheria, pertussis, and Haemophilus influenzae type b. Vaccine-induced immunity, however, may decrease with time, and adult immunization recommendations take into account both waning immunity and age-related risks of exposure and infection. Benefits of immunization are not limited to the vaccinated individual but also include promotion of herd immunity for the population at large, including nonimmunized persons and those with waning immunity or who may not have fully responded to prior vaccination. Immunizations, however, also carry risks that can range from common minor local skin reactions to rare, life-threatening adverse reactions. These risks are carefully weighed in the creation of immunization schedule recommendations, balancing the individual's risk of exposure with the earliest timing that immunizations can be safely and effectively administered.
Infectious Disease Summary
Authors: Klompas Michael , Sax Paul E.
Published: July 2014

This chapter provides an infectious disease summary.
Breast Cancer
Authors: Hassett Michael J. , Shulman Lawrence N.
Published: July 2014

This chapter discusses the epidemiology, prevention, pathology and staging, and treatment of breast cancer.
Gastrointestinal Cancers
Authors: Meyerhardt Jeffrey A.
Published: July 2014

In the United States there will be an estimated 270,000 cases of gastrointestinal malignancies leading to 124,000 deaths annually (table 12.1). Gastrointestinal cancers are the second most common cancers behind those of the genital system (inclusive of gynecological, prostate, and testicular cancer). Worldwide, an estimated 6 million new cases of gastrointestinal cancers are diagnosed annually, accounting for 2.5 million deaths. The most common gastrointestinal cancers in the United States are esophageal, gastric, pancreatic, and colorectal, and these are the focus of this review.
Leukemia
Authors: Antin Joseph H.
Published: July 2014

A lifetime of sustained lymphohematopoiesis requires a stem cell compartment that produces maturing progeny with immaculate fidelity over almost a century. The stem cell gives rise to progenitor cells that are committed to either lymphoid or myeloid development. A variety of mutations can occur in either the stem cell or in a more committed cell that result in excessive proliferation, failure of differentiation, or both. The genes that are affected determine whether the leukemia is myeloid or lymphoid, whether acute or chronic, response to therapy, and, ultimately, prognosis.
Multiple Myeloma
Authors: Mitsiades Constantine S. , Anderson Kenneth C. , Richardson Paul G.
Published: July 2014

Multiple myeloma (MM) is a clonal accumulation of malignant plasma cells (PCs) that typically produce a monoclonal immunoglobulin (Ig) (or fragment thereof), termed M-protein, detectable in the serum or urine. Despite recent advances in its treatment (median overall survival is now 5–7 years, compared to 2–3 years for patients diagnosed 10 or more years ago), MM remains incurable. Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant condition in which a clonal population of plasma cells accumulates in the bone marrow (BM). MGUS is asymptomatic and does not otherwise meet diagnostic criteria for MM, but it can develop into MM, other plasma cell dyscrasia, or lymphoproliferative disease with a transformation rate of approximately 2% per year.
Rheumatoid Arthritis
Authors: Todd Derrick J. , Coblyn Jonathan S.
Published: July 2014

Rheumatoid arthritis (RA) is an idiopathic systemic autoimmune disorder that primarily involves the joints. It causes inflammation of the synovium (synovitis) that can lead to cartilage destruction and bone erosions. Extra-articular manifestations may also occur. The diagnosis of RA is based on a combination of clinical features, laboratory tests, and imaging studies. In recent years, great strides have been made in the pharmacologic treatment of RA, which consists primarily of immunosuppressive or immunomodulatory therapy with disease-modifying antirheumatic drugs (DMARDs). It is important to understand that RA is a heterogeneous disorder: some patients may have a severe, rapidly progressive disease with life-threatening extra-articular symptoms, whereas other patients may have indolent symptoms with little if any joint destruction over time. This point is important when making a diagnosis of RA, and especially when considering treatment options.