bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-orthogonal tight-binding models: Problems and possible remedies for realistic nano-scale devices
Authors: Boykin Timothy B. , Sarangapani Prasad , Klimeck Gerhard
Published: April 2019

Due to recent improvements in computing power, non-orthogonal tight-binding models have moved beyond their traditional applications in molecular electronics to nanoelectronics. These models are appealing due to their physical chemistry content and the availability of tabulated material parameterizations. There are, however, problems with them, related to their non-orthogonality, which are more serious in nanoelectronic vs molecular applications. First, the non-orthogonal basis leads to an inherent ambiguity in the charge density. More importantly, there are problems with the position matrix in a non-orthogonal basis. The position matrix must be compatible with the underlying translationally symmetric system, which is not guaranteed if it is calculated with explicit wavefunctions. In an orthogonal basis, the only way to guarantee compatibility and gauge invariance is to use diagonal position matrices, but transforming them to a non-orthogonal basis requires major computational effort in a device consisting of 103–105 atoms. We study the charge density, position matrix, and optical absorption using a non-orthogonal two-band one-dimensional model, comparing correct and approximate calculations. We find that a typical naïve calculation produces highly inaccurate results, while in contrast a first-order orthogonalized basis can represent a reasonable accuracy-efficiency trade-off.
Effect of Ge doping on growth stress and conductivity in AlxGa1-xN
Authors: Bansal Anushka , Wang Ke , Lundh James Spencer , Choi Sukwon , Redwing Joan M.
Published: April 2019

Silicon (Si) is a common n-type donor in AlxGa1-xN; however, it induces bending of edge-type threading dislocations which can generate tensile stress in the film leading to the formation of channeling cracks in thick layers. Germanium (Ge) has previously been investigated as an alternative to Si for n-type doping of GaN, but its impact on film stress in AlxGa1-xN has not been investigated in detail. In this study, we employ in situ wafer curvature measurements combined with postgrowth characterization to investigate Ge doping of AlxGa1-xN (x = 0–0.62) layers grown on 6H-SiC by metalorganic chemical vapor deposition. It was found that Ge doping (n ∼ 1.6 × 1019 cm−3) of Al0.30Ga0.70N does not induce tensile stress during growth in contrast to that observed with a similar level of Si doping. In addition, the average inclination angle of edge dislocations was similar for undoped and Ge doped films indicating that Ge does not promote surface-mediated dislocation climb. High n-type doping was achieved in Ge doped AlxGa1-xN for lower Al fraction range (x < 0.5), but resistivity increased and carrier density decreased significantly for higher Al fractions. The results demonstrate Ge doping as a viable alternative to Si doping of AlxGa1-xN (x < 0.5) for achieving thick, crack-free layers.
Experimental investigations of wave-DSRR interactions in liquid-phase media
Authors: Li Jian , Wu Zhihao , Huang Yongjun , Ma Liang , Yu Peng , Wen Guangjun
Published: April 2019

In this paper, the mechanical displacement and the resulting resonance shift of a basic double split ring resonator (DSRR) which is placed in different low-loss liquid-phase environments are experimentally demonstrated. Such resulting dynamic process is due to the wave-DSRR interactions and the induced electromagnetic attraction force when an incident electromagnetic wave with enhanced intensity acts on the DSRR. Low-loss liquids including polyalphaolefin and polydimethylsiloxane are used in this paper as the host media to clearly show the electromagnetic resonance and its resonance shift performances. These experimental investigations and the obtained results can create a completely different research direction for the application of metamaterials in liquid-phase environments.
Structure and energy of the 〈11¯〉 screw dislocation in silicon using generalized Peierls theory
Authors: Huang Lili , Wang Shaofeng
Published: April 2019

For the ⟨11¯0⟩ screw dislocation (nondissociated) in silicon, there are three types of core structures that are, respectively, referred to as the shuffle-set dislocation (A-core), glide-set dislocation (C-core), and mix-set dislocation (B-core). Each type of core further displays a planar or nonplanar (fourfold) configuration. In this paper, in the context of the generalized Peierls theory, the energy functional and equation of equilibrium of a screw dislocation with a nonorthogonal fourfold structure is derived and is used to investigate the structure and energy of the ⟨11¯0⟩ screw dislocation in silicon. We find that the energy of the shuffle-set dislocation with a fourfold core is considerably lower than that of the other types of cores. Thus, the shuffle-set dislocation with the fourfold core is the most stable. The glide-set dislocation with a planar core has the highest energy and is the most unstable. As the most stable structure, the shuffle-set screw dislocation with the fourfold core was responsible for wavy slip traces observed at low temperature.
Terahertz emission from biased AlGaN/GaN high-electron-mobility transistors
Authors: Lisauskas Alvydas , Rämer Adam , Burakevič Marek , Chevtchenko Serguei , Krozer Viktor , Heinrich Wolfgang , Roskos Hartmut G.
Published: April 2019

We report on the results of a comprehensive study of THz emission from a set of dedicated AlGaN/GaN high-electron-mobility transistors. We find that voltage-biased transistors indeed emit in the THz frequency range, as reported in the literature; however, our data let us conclude that this radiation cannot be directly attributed to plasmonic instability phenomena. Instead, two other distinct mechanisms are identified. One is based on high-frequency self-oscillations originating from positive feedback within the frequency range where the transistor provides gain. Such oscillations are especially facilitated by the integration of antenna structures and cease to exist after taking specific measures for circuit stabilization. Another mechanism is identified for the case of broadband emission from multifinger transistors fabricated without any specific antenna. In contrast to the predictions of the plasmonic instability picture, the spectra of this emission depend on the gate and drain biasing conditions and on the bias modulation frequency. This emission can be understood as a combination of thermal emission from the heated material and from thermally excited plasmons and trap states.
High-resolution terahertz spectroscopy with quantum-cascade lasers
Authors: Hübers H.-W. , Richter H. , Wienold M.
Published: April 2019

Terahertz (THz) quantum-cascade lasers (QCLs) are narrow band, high-power, and frequency-agile sources. These properties make them attractive for applications in high-resolution molecular and atomic spectroscopy. In the past few years, various techniques and methods regarding high-resolution spectroscopy with THz QCLs have been developed, namely, direct absorption spectroscopy, detection schemes such as wavelength and frequency modulation, differential spectroscopy, photoacoustic spectroscopy, and heterodyne spectroscopy. We briefly review the most relevant technological and methodological advances in this field, and we discuss perspectives and future directions.
Theoretical characterization of C doped SiGe monolayer
Authors: Sharma Durgesh Kumar , Kumar Sudhir , Auluck Sushil
Published: April 2019

Two dimensional Si1−xGeCx (SGC) alloys have been investigated within the framework of density functional theory using the hybrid functional of Heyd-Scuseria-Ernzerhof for the electron exchange correlation potential. The site occupancy disorder program is used to predict the most stable configuration for different values of carbon (C) concentration (x). With increasing C content, the lattice constant decreases almost linearly, while there is a reversal in the bandgap bowing for x>0.50. Besides the ideal solid solutions, we have also studied the effect of the C dimer. The calculated mixing enthalpy suggests that the growth of the alloys follows the endothermic reaction. The spinodal and binodal decomposition curves for Si and C rich phases have been explained along with a growth temperature equal to 2675 K. The valence and conduction band edges are aligned with respect to the vacuum level. The calculated optical absorption coefficient of SGC alloys is greater than 104cm−1, suggesting that these alloys are promising materials for opto-electronic applications. Our results may motivate experimentalists to synthesize these alloys which show promise for efficient thin film devices.
Anisotropic MHD equilibria in symmetric systems
Authors: Souza Leonardo C. , Viana Ricardo L.
Published: April 2019

Using a method developed by Clemente, it is possible to obtain anisotropic magnetohydrodynamic equilibrium in axially symmetric systems, from a previously known solution of the Grad-Schlüter-Shafranov equation. We generalize this method to symmetric systems described by orthogonal as well as nonorthogonal systems of coordinates. Two examples are presented in cylindrical and spherical geometries, for which we give an exact analytic solution of the anisotropic MHD equilibrium.
Sparse non-orthogonal wave function expansions from the extension of the generalized Pauli constraints to the two-electron reduced density matrix
Authors: Boyn Jan-Niklas , Mazziotti David A.
Published: April 2019

Generalized Pauli constraints (GPCs) impose constraints in the form of inequalities on the natural orbital occupation numbers of the one electron reduced density matrix (1-RDM), defining the set of pure N-representable 1-RDMs, or 1-RDMs that can be derived from an N-electron wave function. Saturation of these constraints is termed “pinning” and implies a significant simplification of the N-electron wave function as the number of Slater determinants required to fully describe the system is reduced. Recent research has shown pinning to occur for the ground states of atoms and molecules with N = 3 and r = 6, where N is the number of electrons and r is the number of spin orbitals. For N = 4 and r = 8, however, pinning occurs not to the GPCs but rather to inequalities defining the pure N-representable two-electron reduced density matrices (2-RDMs). Using these more general inequalities, we derive a wave function ansatz for a system with four electrons in eight spin orbitals. We apply the ansatz to the isoelectronic series of the carbon atom and the dissociation of linear H4 where the correlation energies are recovered to fractions of a kcal/mol. These results provide a foundation for further developments in wave function and RDM theories based on “pinned” solutions, and elucidate a fundamental physical basis for the emergence of non-orthogonal bases in electronic systems of N ≥ 4.
Effect of viscoelastic medium on wave propagation along protein microtubules
Authors: Safeer Muhammad , Taj M. , Abbas Syed Solat
Published: April 2019

An Orthotropic Kelvin-like model is developed here to study wave dispersion relation along microtubules when they are embedded in viscoelastic material. Owing anisotropicity of elastic shell like microtubules, an orthotropic elastic shell model is derived while the surrounding environment of microtubules is modeled as Kelvin like material. Symmetrical and asymmetrical waves are studied in embedded microtubules. We compared the wave velocities for embedded and free microtubules as well as the comparison of wave velocities for isotropic and orthotropic microtubules are also given. Longitudinal, Torsional and Radial wave velocities are obtained, noticing that torsional and radial wave velocities are lower in embedded microtubules as compared to longitudinal wave velocities in embedded microtubules. The radial wave frequency is considerably low because in cylindrical microtubules, pressure is exerted from the surroundings. The decrease in wave velocities is due to strong mechanical coupling of microtubules with surrounding medium and this decrement is more obvious when the wave length is long.
Dynamic mode decomposition for the inspection of three-regime separated transitional boundary layers using a least squares method
Authors: Alessandri A. , Bagnerini P. , Gaggero M. , Lengani D. , Simoni D.
Published: April 2019

Transitional boundary layers undergoing separated flow transition for different free stream turbulence intensity levels and Reynolds numbers have been inspected by applying dynamic mode decomposition (DMD) to time-resolved particle image velocimetry data. The identification of the unstable modes responsible for transition suffers from nonlinear effects if the whole dataset is considered for the construction of the snapshot matrix underlying the flow evolution. To overcome this limit, piecewise linear models aimed at the identification of the different regimes in the entire transition process are proposed. In particular, the flow is initially laminar (i.e., stable), it becomes unstable due to transition, and once transition is completed, the fully turbulent condition leads the boundary layer to a stable regime. The norm of the residuals resulting from the application of DMD on a variable streamwise extension of the dataset shows a trend that is associated with the variation of regime. This trend is analyzed by means of the least squares method, which allows identifying the change in the regime with stable, unstable, and turbulent behaviors. The validity of this procedure is proved by comparing it with previously published results. Moreover, since the DMD is applied to limited temporal snapshots, it provides a temporal resolution of growth rate and positions of switch between the boundary layer states. Such information is used to extract from the big dataset under analysis the time sequences characterized by the largest growth rate, hence quickly highlighting the flow physics driving transition.
Breakdown of the scallop theorem for an asymmetrical folding molecular motor in soft matter
Authors: Teboul Victor , Rajonson Gabriel
Published: April 2019

We use molecular dynamic simulations to investigate the motion of a folding molecular motor inside soft matter. Purcell’s scallop theorem forbids the displacement of the motor due to time symmetrical hydrodynamic laws at low Reynolds numbers whatever the asymmetry of the folding and unfolding rates. However, the fluctuation theorems imply a violation of the time symmetry of the motor’s trajectories due to the entropy generated by the motor, suggesting a breakdown of the scallop theorem at the nanoscale. To clarify this picture, we study the predicted violation of time reversibility of the motor’s trajectories, using two reverse asymmetric folding mechanisms. We actually observe this violation of time reversibility of the motor’s trajectories. We also observe the previously reported fluidization of the medium induced by the motor’s folding, but find that this induced diffusion is not enough to explain the increase of the motor’s displacement. As a result, the motor is not carried by the medium in our system but moves by its own, in violation of the scallop theorem. The observed violation of the scallop theorem opens a route to create very simple molecular motors moving in soft matter environments.
Tuning interlayer coupling by laser irradiation and broadband photodetection in vertical MoTe2/WS2 vdW heterostructure
Authors: Wu Zhangting , Zhu Nianchuang , Jiang Jie , Zafar Amina , Hong Jintao , Zhang Yang
Published: April 2019

van der Waals (vdW) heterostructures constructed by stacking different two dimensional layered materials are extensively utilized in designing novel optoelectronic devices, such as photodetectors and light-emitting diodes. However, the performance of vertical heterostructures is impeded by challenges in effectively achieving interlayer coupling. Here, the systematic demonstration of vertical MoTe2/WS2 vdW heterostructures assembled by a mechanical transfer technique is reported, whereas the interlayer interaction is tuned from weak coupling to strong coupling by laser irradiation. Thereafter, the improved interlayer interaction of heterostructures is characterized by photoluminescence spectroscopy and further confirmed by electrical transport. Moreover, visible-infrared broadband photoresponse is achieved in the vertical stacking with the built-in field generated between MoTe2 and WS2. Thus, the outstanding findings of our experimental approach can facilitate novel two-dimensional devices for the optoelectronics industry.
Scaling laws for the transient convective flow in a differentially and linearly heated rectangular cavity at Pr > 1
Authors: Liu Yang , Bian Yongning , Zhao Yongling , Zhang Shuaikun , Suo Qinghui
Published: April 2019

The convective flow in a differentially heated cavity, with linear temperature profiles at two sidewalls, is investigated in the present study by a scaling analysis and direct numerical simulations (DNS). Scales for the thermal boundary layer and the subsequent intrusion are obtained through the scaling analysis. The velocity scale reveals that the characteristic velocity of the thermal boundary layer depends on both the streamwise position and the time after the initiation of the flow, which suggests a two-dimensional growth at the start-up stage, rather than the well-known one-dimensional growth of the thermal boundary layer induced by a constant temperature boundary condition. Furthermore, unlike the typical transition of the thermal boundary layer to a two-dimensional and steady stage that is characterized by the dying out of a “temperature overshoot” phenomenon, the thermal boundary layer under consideration enters a two-dimensional and steady stage smoothly, without the occurrence of the temperature overshoot. It is also found that, with the passage of time, whilst the characteristic velocity of the thermal boundary layer depends on the streamwise position, the thickness of the thermal boundary layer is streamwise position independent due to infinitesimally small time. Four possible flow regimes and corresponding scales for the unsteady intrusion flow underneath the cavity ceiling are finally obtained, which are two types of viscous-buoyancy dominated regimes and two types of inertial-buoyancy dominated ones. The important scales obtained in the present study are validated by corresponding DNS results.
Effects of laser wavelength on aluminum plasma in transverse magnetic fields
Authors: Dieffenbach Payson C. , Borkowski Carolyn M. , Elsied Ahmed , Diwakar Prasoon K. , Sizyuk Tatyana , Hassanein Ahmed
Published: April 2019

The influence of the laser wavelength on nanosecond laser-produced Al plasma in a transverse magnetic field is studied and presented. A Q-switch Nd:YAG pulsed laser (FWHM: 6 ns) is used to ablate an aluminum sample at 50 mJ at the fundamental, second, and fourth harmonics of 1064 nm, 532 nm, and 266 nm, respectively. A permanent magnetic trap is used with a nearly uniform magnetic field of 0.8 T to confine plasma expansion, reduce both fast and slow components of plasma velocity, and increase signal intensity. Fast photography is performed using an Intensified Charged Coupled Device camera to study the plume hydrodynamics as it evolves through the induced magnetic field. Optical Emission Spectroscopy is used to determine the effect of the laser wavelength on key ionic and neutral emission lines, as well as to study the enhancement and reduction of certain emission lines in the presence of a magnetic field. Fast photography results confirm that the laser wavelength has a significant effect on plume hydrodynamics, especially as it evolves through the magnetic field. The magnetic field confines both fast and slow components of the plasma as early as ∼45 ns after laser impact for all laser wavelengths used, as well as reducing the velocity of the plasma by about 5×. It is shown that the 266 nm laser wavelength under the magnetic field enhanced both ionic and neutral lines by up to 11×, while 532 nm laser plasma only showed enhancements in ionic lines with reduction in neutral. A laser wavelength of 1064 nm showed a slight enhancement of ionic lines with a significant reduction in neutral lines under the same conditions.
Investigation of the crystal structure of polymorphic KNbO3 nanowires by pressure
Authors: Oh Kyoung Hun , Ko Young-Ho , Kim Kwang-Joo
Published: April 2019

We have investigated the pressure-induced structural phase transition of orthorhombic and monoclinic KNbO3 nanowires by using x-ray diffraction (XRD) and Raman spectroscopy. Monoclinic KNbO3 nanowires underwent phase transitions three times: monoclinic to tetragonal, tetragonal to cubic, and cubic to orthorhombic-2 phase near 2.2 GPa, 8.2 GPa, and 40.0 GPa, respectively. Meanwhile, orthorhombic KNbO3 nanowires showed a phase transition once, orthorhombic to cubic phase near 8.5 GPa. Their exact structures were determined by the Rietveld method and confirmed by Raman spectroscopy. P-V equations of state for two kinds of KNbO3 nanowires were also derived from XRD data. Moreover, the elastic properties of the two nanowires in various structural phases were calculated. It was observed that two polymorphic nanowires, one from the monoclinic phase and the other from the orthorhombic phase, might have different isothermal bulk moduli even in the same crystal phase under high pressure.
A computational study of gadolinium-doped ceria: Relationship between atomic arrangement and electrostriction
Authors: Asher M. , Diéguez O.
Published: April 2019

Experimental studies have found a giant electrostriction effect in gadolinium-doped ceria (GDC) despite its low permittivity. This unique phenomenon has been linked to the presence of overcompensating vacancies and to the occurrence of a phase transition, implying an abrupt change in cation-oxygen bond distance. In this study, we have used computational methods based on density functional theory and on interatomic potentials to help understand the mechanism of the electrostriction effect in GDC. By combining these two methods, we obtained the lowest-energy configurations of Ce1−xGdxO2−x/2 in the entire range of x. Our results suggest that no ordinary phase transition exists as a function of the composition. However, the atomic rearrangements that occur as the concentration of vacancies and dopants increases cause an abrupt change in cation-oxygen bond distance that could be responsible for the electrostrictive properties of GDC.
Using artificial magnetic conductors to improve the efficiency of wireless power transfer
Authors: Shi Taixia , Dong Lijuan , Chen Yongqiang , Sun Yong , Liu Yanhong , Deng Fusheng , Liu Lixiang , Shi Yunlong , Shen Yanyan
Published: April 2019

In this study, an advanced wireless power transfer (WPT) system of two coils with the artificial magnetic conductors (AMC) is explored through simulations and experiments. The AMC structure is added on the transmitter coil, and the multiple resonant modes on the surface of the AMC can be energized. On the other hand, the AMC structure act as a magnetic field shield, which leads to the magnetic field above AMC structure is localized. Therefore, the localized resonant magnetic field enhance the transmission coefficient of the WPT system. The results show that the WPT transmission coefficient is increased from 16% to 35% in the experiment at 26.2 MHz resonant frequency when transmission distance is 3 cm. The experimental results agree with the simulation results. Additionally, AMC has the advantages of low-cost and can easily be installed on the WPT system.
A practical X-ray photoelectron spectroscopy guide aims to improve the method’s widespread usage
Authors: Johnson-Groh Mara
Published: April 2019

Proper usage of X-ray photoelectron spectroscopy is often challenging for new users, but a new guide provides the first steps to correctly planning, conducting, and reporting XPS measurements.
Physical activity counselling and referrals by general practitioners for prostate cancer survivors in Australia
Authors: Barnes Katelyn , Ball Lauren , Galvão Daniel A. , Newton Robert U. , Chambers Suzanne K. , Harrison Christopher
Published: April 2019

Physical activity is an important component of standard care to ensure quality of life for prostate cancer survivors. This paper describes the frequency of physical activity management (physical activity counselling or referrals) by GPs for prostate cancer survivors. A secondary aim is to explore GP characteristics that may influence physical activity recommendations, such as GP or patient age, GP gender and GP geographical location. Analysis was conducted using the longitudinal survey data from the Bettering the Care and Evaluation of Health (BEACH) study. Consultations where prostate cancer was managed, but not classified as a new problem or associated with palliative care, were included. GPs provided physical activity recommendations at 2.0% (n = 58/2882) of prostate cancer survivorship management contacts. The physical activity management provided was physical activity counselling on 39 occasions and a physical activity referral on 19 occasions. All physical activity referrals were made to physiotherapy. After controlling for potential confounding factors, results showed that younger GPs used physical activity management at four-fold the rate of older GPs, and that GPs in major cities used physical activity management at twice the rate of rural GPs. No patient characteristics influenced physical activity management. Australian GPs rarely incorporate physical activity management as part of their management of prostate cancer. Strategies are needed to increase the frequency with which GPs recommend physical activity for prostate cancer survivors.
Xenophobic Trumpeters
Authors: Knoblock Natalia
Published: April 2019

Immigration has been and remains a conspicuous topic in American political
debate, and the ongoing refugee crisis in Europe, exasperated by the Syrian conflict, has brought the issue of Muslim immigration into focus. The topic has been exploited, among others, by the presidential candidate Donald J. Trump. His proposal to ban Muslims from entering the U.S. achieved great resonance and stimulated passionate discussion. This discussion, which displayed a high degree of xenophobia and verbal aggression, is the target of this paper’s investigation. Material was collected from Trump’s official Facebook page and was analyzed using Critical Discourse Analysis and Corpus Linguistic methods. The results highlight the strategies employed in discourse that aims to posit Muslims as “Others” and as incompatible with American society, as well as dangerous, aggressive, and inferior, through the choice of semantic, syntactic, and rhetorical discursive structures.
Multi-twist polarization ribbon topologies in highly-confined optical fields
Authors: Bauer Thomas , Banzer Peter , Bouchard Frédéric , Orlov Sergej , Marrucci Lorenzo , Santamato Enrico , Boyd Robert W , Karimi Ebrahim , Leuchs Gerd
Published: April 2019

Electromagnetic plane waves, solutions to Maxwell’s equations, are said to be ‘transverse’ in vacuum. Namely, the waves’ oscillatory electric and magnetic fields are confined within a plane transverse to the waves’ propagation direction. Under tight-focusing conditions however, the field can exhibit longitudinal electric or magnetic components, transverse spin angular momentum, or non-trivial topologies such as Möbius strips. Here, we show that when a suitably spatially structured beam is tightly focused, a three-dimensional polarization topology in the form of a ribbon with two full twists appears in the focal volume. We study experimentally the stability and dynamics of the observed polarization ribbon by exploring its topological structure for various radii upon focusing and for different propagation planes.
Observation of ladder-type electromagnetically induced transparency with atomic optical lattices near a nanofiber
Authors: Su Dianqiang , Liu Ruijuan , Ji Zhonghua , Qi Xiaodong , Song Zixuan , Zhao Yanting , Xiao Liantuan , Jia Suotang
Published: April 2019

Tapered nanofiber is an efficient tool for enhancing light–matter interactions. Here, we experimentally demonstrate the ladder-type electromagnetically induced transparency (EIT) in one-dimensional atomic lattices near an optical nanofiber (ONF). A typical EIT signal is well fitted from experimental data according to a semiclassical model and implies a transmission nearly 35%. We investigate the dependence of EIT transmission on the coupling power and its saturation condition. In addition, we show a large fraction of the transmission spectral broadening is induced by lattice effects. Our results may pave the road towards generating correlations and entanglement through four-wave mixing with ONFs, which may facilitate the realization of efficient quantum optical networks.
Huge power factor in p-type half-Heusler alloys NbFeSb and TaFeSb
Authors: Naydenov G A , Hasnip P J , Lazarov V K , Probert M I J
Published: April 2019

NbFeSb is a promising thermoelectric material which according to experimental and theoretical studies exhibits a high power factor of up to 10 mW m−1 K−2 at room temperature and ZT of 1 at 1000 K. In all previous theoretical studies, κ

latt
is calculated using simplified models, which ignore structural defects. In this work, we calculate κ

latt
by solving the Boltzmann transport equation and subsequently including the contributions of grain boundaries, point defects and electron–phonon interaction. The results for κ

latt
and ZT are in excellent agreement with experimental measurements. In addition, we investigate theoretically the thermoelectric properties of TaFeSb. The material has recently been synthesised experimentally, thus confirming the theoretical hypothesis for its stability. This encourages a full-scale computation of its thermoelectric performance. Our results show that TaFeSb is indeed an excellent thermoelectric material which has a very high power factor of 16 mW m−1 K−2 at room temperature and ZT of 1.5 at 1000 K.
Current practices in the delivery of pharmacogenomics: Impact of the recommendations of the Pharmacy Practice Model Summit
Authors: Valgus John , Weitzel Kristin W , Peterson Josh F , Crona Daniel J , Formea Christine M
Published: April 2019

Purpose

This report examines and evaluates pharmacogenomics as an emerging science as it relates to the Practice Advancement Initiative and its predecessor the Pharmacy Practice Model Initiative’s consensus statements for optimal pharmacy practice models.

Pharmacogenomics is one of many emerging sciences to impact medication management and delivery of patient care. Increasingly, biomarkers are included in drug labeling and can assist pharmacists with personalizing medicine to optimize patient therapies and avoid adverse effects. The 2011 ASHP Pharmacy Practice Model Summit generated a list of 147 consensus statements for optimal pharmacy practice. Of these, 1 statement explicitly describes adjustment of drug regimens based on genetic factors as an essential activity of pharmacist-provided drug regimens, and 9 other statements provide additional support for incorporation of this emerging science into all aspects of patient care provided by pharmacists. We describe 4 institutions that have made significant inroads to implementing pharmacogenomics, to provide a framework and serve as resources for other institutions initiating their own pharmacogenomics implementation journeys.

Conclusion

Through prioritized efforts of the pharmacy profession and health care institutions, pharmacogenomics will be disseminated and implemented, and the goal of the Pharmacy Practice Model Initiative’s consensus statements of improving health care using patients’ genetic characteristics will be realized.
Perivascular Hyaluronidase With Alteplase as Treatment for Hyaluronic Acid Thrombosis
Authors: Baley-Spindel Isaac , Villaseñor-Villalpando Eduardo , Márquez-Espriella Cuahutémoc , Rivera-Salgado Ma. Irene , Dávila-Díaz Rodrigo
Published: April 2019

Background

Hyaluronic acid fillers are the second-most commonly performed nonsurgical procedure. Arterial thrombosis is their most devastating complication. Recent research shows that along hyaluronic acid thrombi, a platelet/fibrin thrombus forms in the site of injection. This is not addressed by current management protocols, which focus on perivascular hyaluronidase plus adjuvant strategies to increase blood flow. We experimented with an animal model utilizing both hyaluronidase and a thrombolytic agent for treatment of occlusion.

Objectives

The authors sought to evaluate the efficacy of a combined treatment of hyaluronidase with a thrombolytic agent applied perivascularly to an artery occluded with hyaluronic acid.

Methods

After direct intravascular injection into the femoral artery, rats were randomized to receive one of the following perivascular solutions: saline, hyaluronidase, alteplase, or hyaluronidase + alteplase. Reperfusion, distal bleeding, and microscopic findings were evaluated 4 hours after intervention.

Results

None of the subjects in the control group showed signs of reperfusion. In the hyaluronidase group, 60% reperfused, 10% completely, the rest only partially. In the alteplase group, 50% reperfused partially. In the hyaluronidase + alteplase group, 50% had partial and 50% complete prepermeabilization. Kruskal-Wallis test showed a P < 0.0001 favoring hyaluronidase + alteplase. Microscopic findings were compatible with bleeding rates.

Conclusions

Both hyaluronic acid and red thrombi play a role in the occluded vessel. Perivascular application of hyaluronidase with a thrombolytic agent seems to achieve greater reperfusion rates than either one alone. If proven safe in humans, this strategy could make treatment more effective while still being suitable for an outpatient setting.
The Impact of Skin Care Product Sales in an Aesthetic Plastic Surgery Practice
Authors: Austin Ryan E , Ahmad Jamil , Lista Frank
Published: April 2019

Background

Despite significant growth of the global skin care market, many plastic surgeons do not offer skin care products through their aesthetic practice. However, skin care products represent a significant potential revenue stream for plastic surgeons, not only by generating revenue from product sales but by improving patient retention over time and, in turn, generating additional surgical and nonsurgical revenue.

Objectives

The purpose of this study was to determine the financial implications that skin care sales can have for an aesthetic surgery practice. Our hypothesis was that patients making skin care purchases would generate higher non-skin care revenue than patients not purchasing skin care products.

Methods

A retrospective chart review was performed of all purchases made within a single aesthetic surgery practice during a 6-year period (2012-2017). Pre-tax revenue ($CAD) from each category was recorded for any patient who made a purchase during the study period.

Results

A total 3785 patients purchased skin care products, 5088 patients purchased nonsurgical treatments, and 3504 patients underwent surgery. Average patient spending was $720.73 (skin care), $1272.63 (nonsurgical), and $10,048.34 (surgery), respectively. Overall, patients who purchased skin care generated more revenue from the purchases of nonsurgical treatments and surgery than patients who did not purchase skin care products.

Conclusions

Skin care sales not only generate revenue, but over time these patients spend more on nonsurgical and surgical treatments than patients who do not purchase skin care. Skin care is an important adjuvant to nonsurgical and surgical treatments that should be considered by all aesthetic surgeons.
Gone with the rain: negative effects of rainfall on male reproductive success in a nest-building arachnid
Authors: Rojas Andrés , Solano-Brenes Diego , Muniz Danilo G , Machado Glauco
Published: April 2019

In nest-building species, offspring survival and reproductive success of parental individuals are strongly influenced by nest quality. Thus, quantifying the influence of abiotic conditions on nest integrity is important to predict the effects of weather variability on the fitness of parental individuals. Here, we investigated how rainfall affects nest integrity and how nest integrity influences males’ attractiveness and nest tenure. Our study species was the harvestman Quindina limbata, in which males build mud nests on fallen logs and protect the eggs against predators and fungi. Our data set comprises 12 months of regular inspections of 149 nests in a Costa Rican rainforest. We found that almost 50% of the nests were destroyed by rainfall. The drag force caused by rainfall running on the fallen log surface negatively affected nest integrity. Fungi cover on nests was influenced by an interaction between rainfall and nest position on the fallen log. Irrespective of their body size, males in nests with high integrity received more eggs than males in nests with low integrity. Fungi cover did not influence the number of eggs received by the males. Finally, nest integrity and fungi cover did not affect nest tenure, but males that did not receive eggs for a long time tended to abandon their nests. Considering that intense rainfall occurs all year long in tropical forests, males should build their nests in protected sites that preserve nest structure. Protected sites may keep nest structure better preserved, improve offspring survival, attract more females, and increase males’ reproductive success.
A comprehensive overview of oncogenic pathways in human cancer
Authors: Li Feng , Wu Tan , Xu Yanjun , Dong Qun , Xiao Jing , Xu Yingqi , Li Qian , Zhang Chunlong , Gao Jianxia , Liu Liqiu , Hu Xiaoxu , Huang Jian , Li Xia , Zhang Yunpeng
Published: April 2019

Alterations of biological pathways can lead to oncogenesis. An overview of these oncogenic pathways would be highly valuable for researchers to reveal the pathogenic mechanism and develop novel therapeutic approaches for cancers. Here, we reviewed approximately 8500 literatures and documented experimentally validated cancer-pathway associations as benchmarking data set. This data resource includes 4709 manually curated relationships between 1557 paths and 49 cancers with 2427 upstream regulators in 7 species. Based on this resource, we first summarized the cancer-pathway associations and revealed some commonly deregulated pathways across tumor types. Then, we systematically analyzed these oncogenic pathways by integrating TCGA pan-cancer data sets. Multi-omics analysis showed oncogenic pathways may play different roles across tumor types under different omics contexts. We also charted the survival relevance landscape of oncogenic pathways in 26 tumor types, identified dominant omics features and found survival relevance for oncogenic pathways varied in tumor types and omics levels. Moreover, we predicted upstream regulators and constructed a hierarchical network model to understand the pathogenic mechanism of human cancers underlying oncogenic pathway context. Finally, we developed `CPAD’ (freely available at http://bio-bigdata.hrbmu.edu.cn/CPAD/), an online resource for exploring oncogenic pathways in human cancers, that integrated manually curated cancer-pathway associations, TCGA pan-cancer multi-omics data sets, drug–target data, drug sensitivity and multi-omics data for cancer cell lines. In summary, our study provides a comprehensive characterization of oncogenic pathways and also presents a valuable resource for investigating the pathogenesis of human cancer.
Modelling G×E with historical weather information improves genomic prediction in new environments
Authors: Gillberg Jussi , Marttinen Pekka , Mamitsuka Hiroshi , Kaski Samuel
Published: April 2019

Motivation

Interaction between the genotype and the environment (G×E) has a strong impact on the yield of major crop plants. Although influential, taking G×E explicitly into account in plant breeding has remained difficult. Recently G×E has been predicted from environmental and genomic covariates, but existing works have not shown that generalization to new environments and years without access to in-season data is possible and practical applicability remains unclear. Using data from a Barley breeding programme in Finland, we construct an in silico experiment to study the viability of G×E prediction under practical constraints.

Results

We show that the response to the environment of a new generation of untested Barley cultivars can be predicted in new locations and years using genomic data, machine learning and historical weather observations for the new locations. Our results highlight the need for models of G×E: non-linear effects clearly dominate linear ones, and the interaction between the soil type and daily rain is identified as the main driver for G×E for Barley in Finland. Our study implies that genomic selection can be used to capture the yield potential in G×E effects for future growth seasons, providing a possible means to achieve yield improvements, needed for feeding the growing population.

Availability and implementation

The data accompanied by the method code (http://research.cs.aalto.fi/pml/software/gxe/bioinformatics_codes.zip) is available in the form of kernels to allow reproducing the results.

Supplementary information

Supplementary data are available at Bioinformatics online.
The Potential of Equine-Assisted Psychotherapy for Treating Trauma in Australian Aboriginal Peoples
Authors: Bennett Bindi , Woodman Elise
Published: April 2019

Colonisation and subsequent policies targeting Aboriginal peoples in Australia have had devastating consequences, including trauma, disadvantage and marginalisation. These effects have passed from generation to generation and continue to manifest in poor health and well-being outcomes, particularly mental health disorders. Innovative and culturally relevant techniques are needed to remedy inequality and address intergenerational trauma. Equine-assisted psychotherapy (EAP)—an experiential therapy involving horses—is a new and increasingly evidence-based treatment approach, which offers potential for working with Aboriginal peoples. This article reviews the literature on outcomes of EAP to consider its potential as a culturally responsive therapy to treat trauma and increase well-being for Aboriginal people in Australia.
E6AP goes viral: the role of E6AP in viral- and non-viral-related cancers
Authors: Bandilovska Ivona , Keam Simon P , Gamell Cristina , Machicado Claudia , Haupt Sue , Haupt Ygal
Published: April 2019

Since its discovery, the E3 ubiquitin ligase E6-associated protein (E6AP) has been studied extensively in two pathological contexts: infection by the human papillomavirus (HPV), and the neurodevelopmental disorder, Angelman syndrome. Vital biological links between E6AP and other viruses, namely hepatitis C virus and encephalomyocarditis virus, have been recently uncovered. Critically, oncogenic E6AP activities have been demonstrated to contribute to cancers of both viral and non-viral origins. HPV-associated cancers serve as the primary example of E6AP involvement in cancers driven by viruses. Studies over the past few years have exposed a role for E6AP in non-viral-related cancers. This has been demonstrated in B-cell lymphoma and prostate cancers, where oncogenic E6AP functions drive these cancers by acting on key tumour suppressors. In this review we discuss the role of E6AP in viral infection, viral propagation and viral-related cancer. We discuss processes affected by oncogenic E6AP, which promote cancers of viral and non-viral aetiology. Overall, recent findings support the role of oncogenic E6AP in disrupting key cellular processes, including tumour suppression and the immune response. E6AP is consequently emerging as an attractive therapeutic target for a number of specific cancers.
The Graded Change in Connectivity across the Ventromedial Prefrontal Cortex Reveals Distinct Subregions
Authors: Jackson Rebecca L , Bajada Claude J , Lambon Ralph Matthew A , Cloutman Lauren L
Published: April 2019

The functional heterogeneity of the ventromedial prefrontal cortex (vmPFC) suggests it may include distinct functional subregions. To date these have not been well elucidated. Regions with differentiable connectivity (and as a result likely dissociable functions) may be identified using emergent data-driven approaches. However, prior parcellations of the vmPFC have only considered hard splits between distinct regions, although both hard and graded connectivity changes may exist. Here we determine the full pattern of change in structural and functional connectivity across the vmPFC for the first time and extract core distinct regions. Both structural and functional connectivity varied along a dorsomedial to ventrolateral axis from relatively dorsal medial wall regions to relatively lateral basal orbitofrontal cortex. The pattern of connectivity shifted from default mode network to sensorimotor and multimodal semantic connections. This finding extends the classical distinction between primate medial and orbital regions by demonstrating a similar gradient in humans for the first time. Additionally, core distinct regions in the medial wall and orbitofrontal cortex were identified that may show greater correspondence to functional differences than prior hard parcellations. The possible functional roles of the orbitofrontal cortex and medial wall are discussed.
Arrhythmogenic propensity of the fibrotic substrate after atrial fibrillation ablation: a longitudinal study using magnetic resonance imaging-based atrial models
Authors: Ali Rheeda L , Hakim Joe B , Boyle Patrick M , Zahid Sohail , Sivasambu Bhradeev , Marine Joseph E , Calkins Hugh , Trayanova Natalia A , Spragg David D
Published: April 2019

Aims

Inadequate modification of the atrial fibrotic substrate necessary to sustain re-entrant drivers (RDs) may explain atrial fibrillation (AF) recurrence following failed pulmonary vein isolation (PVI). Personalized computational models of the fibrotic atrial substrate derived from late gadolinium enhanced (LGE)-magnetic resonance imaging (MRI) can be used to non-invasively determine the presence of RDs. The objective of this study is to assess the changes of the arrhythmogenic propensity of the fibrotic substrate after PVI.

Methods and results

Pre- and post-ablation individualized left atrial models were constructed from 12 AF patients who underwent pre- and post-PVI LGE-MRI, in six of whom PVI failed. Pre-ablation AF sustained by RDs was induced in 10 models. RDs in the post-ablation models were classified as either preserved or emergent. Pre-ablation models derived from patients for whom the procedure failed exhibited a higher number of RDs and larger areas defined as promoting RD formation when compared with atrial models from patients who had successful ablation, 2.6 ± 0.9 vs. 1.8 ± 0.2 and 18.9 ± 1.6% vs. 13.8 ± 1.5%, respectively. In cases of successful ablation, PVI eliminated completely the RDs sustaining AF. Preserved RDs unaffected by ablation were documented only in post-ablation models of patients who experienced recurrent AF (2/5 models); all of these models had also one or more emergent RDs at locations distinct from those of pre-ablation RDs. Emergent RDs occurred in regions that had the same characteristics of the fibrosis spatial distribution (entropy and density) as regions that harboured RDs in pre-ablation models.

Conclusion

Recurrent AF after PVI in the fibrotic atria may be attributable to both preserved RDs that sustain AF pre- and post-ablation, and the emergence of new RDs following ablation. The same levels of fibrosis entropy and density underlie the pro-RD propensity in both pre- and post-ablation substrates.