bluuebunny/crossref_metadata_2025 huggingface dataset:
Workload and Injury in Professional Soccer Players: Role of Injury Tissue Type and Injury Severity
Authors: Enright Kevin , Green Matthew , Hay Gordon , Malone James J.
Published: December 2019

The purpose of the present study was to examine the influence of workload prior to injury on injury (tissue type and severity) in professional soccer players. Twenty-eight days of retrospective training data prior to non-contact injuries (n=264) were collated from 192 professional soccer players. Each injury tissue type (muscle, tendon and ligament) and severity (days missed) were categorised by medical staff. Training data were recorded using global positioning system (GPS) devices for total distance (TD), high speed distance (HSD,>5.5 m/s−1), and sprint distance (SPR,>7.0 m/s−1). Accumulated 1, 2, 3, 4-weekly loads and acute:chronic workload ratios (ACWR) (coupled, uncoupled and exponentially weighted moving average (EWMA) approaches) were calculated. Workload variables and injury tissue type were compared using a one-way ANOVA. The association between workload variables and injury severity were examined using a bivariate correlation. There were no differences in accumulated weekly loads and ACWR calculations between muscle, ligament, and tendon injuries (P>0.05). Correlations between each workload variable and injury severity highlighted no significant associations (P>0.05). The present findings suggest that the ability of accumulated weekly workload or ACWR methods to differentiate between injury type and injury severity are limited using the present variables.
Risks and Strategies to Avoid Approach-Related Complications During Operative Treatment of Pelvic Ring or Acetabular Fractures
Authors: Küper Markus Alexander , Trulson Alexander , Minarski Christian , Stuby Fabian , Stöckle Ulrich , Konrads Christian
Published: December 2019

Injuries of the pelvic ring or the acetabulum are either to be found in young patients with high energy trauma mechanisms or in geriatric patients after simple falls with very low impact energy. The indication for surgical stabilization is given by the grade of instability. Exact knowledge of the different possible surgical approaches is essential for the planning of the surgical treatment. Both, knowledge of reachable anatomical structures and possible risks of the different approaches are important. In this review, we summarize the standard surgical approaches to the pelvic ring and to the acetabulum. We describe the reachable anatomical structures for each approach, approach-related pitfalls, and we focus on strategies to reduce approach-related complications.
Thyroid Dysfunction and Cholesterol Gallstone Disease
Authors: Kube Irina , Zwanziger Denise
Published: December 2019

Cholesterol gallstone disease (CGD) affects 10–15% of the adult population worldwide and the prevalence increases as a result of longer life expectancy as well as rising obesity in the general population. Beside well established CGD risk factors including environmental and genetic determinants (LITH genes), a correlation between thyroid dysfunction and CGD has been suggested in several human and murine studies. Although the precise underlying mechanisms are poorly understood, thyroid hormones may impact bile flow, bile composition and the maintenance of the enterohepatic circulation. Further there is evidence that thyroid hormones possibly impact LITH genes which are regulated by nuclear receptors (NRs). A better understanding of the CGD pathomechanisms might contribute to personalized prevention and therapy of highly prevalent and economically significant digestive disease. This review presents the current knowledge about the association between CGD and thyroid hormone dysfunction.
Catalytic Strategies to Enantiopure Benzoins: Past and Future
Authors: De Luca Lorena , Mezzetti Antonio
Published: December 2019

The catalytic strategies developed so far for the synthesis of enantiomerically pure benzoins are reviewed. Particular attention is given to their substrate scope and limitations. Finally, this short review highlights the advantages of more atom-economic methods that have been reported recently.

1 Introduction

2 Benzoin Condensation

2.1 Nucleophilic Carbenes as Catalysts

2.2 Homocondensation of Aromatic Aldehydes

2.3 Cross-Benzoin Condensation

2.4 Acyloin Condensation

2.5 Biocatalytic Methods

3 Organocatalytic Friedel–Crafts Reaction

4 Oxidative Methods

4.1 α-Hydroxylation of Ketones

4.2 Ketohydroxylation of Alkenes

4.3 Enantiospecific Oxidation of meso-Hydrobenzoins

4.4 Kinetic Resolution of Racemic Hydrobenzoins

4.5 Biocatalytic Dynamic Kinetic Resolution

5 Asymmetric Hemireduction of Benzils

5.1 Biocatalytic Reductions – A Brief Summary

5.2 Piers Hydrosilylation of Benzils

5.3 Photoreduction of Benzils to Benzoins

5.4 Metal-Catalyzed Hemihydrogenation of Benzils

6 Conclusion and Future Challenges
Investigation on piezoelectric energy harvester with different combination actuated by the hyperbaric uniform air load
Authors: Wang Yingting , Bao Gang , Xiang Dong
Published: December 2019

This paper describes an experimental study of compressed air energy harvesting by a piezoelectric energy harvester. We conducted parametric studies to evaluate the influence of different combinations of piezoelectric patches and the resulting energy output. We have demonstrated the rules for appropriate connection relationships. A peak output power of 0.65 mW occurred at the parallel connection type, and the peak voltage is 32.4 V. The results prove that the parallel connection is better than the series connection. As the number of parallel connections increases, the optimal load resistance decreases gradually. The output power becomes larger when the numbers of piezoelectric patches increase in the same condition.
Magnetic cubics in Riemannian manifolds associated with different magnetic fields
Authors: Zhang Erchuan
Published: December 2019

Analogous to magnetic curves generalizing geodesics, magnetic cubics are generalized Riemannian cubics in the presence of magnetic fields. In this paper, we mainly study magnetic cubics in Riemannian manifolds associated with different magnetic fields. In addition to presenting the differential equations for magnetic cubics, we find the connection between magnetic cubics and Riemannian cubics in Lie groups and Sasakian space forms. Furthermore, some closed form solutions are achieved for special magnetic cubics, for instance, the so-called null magnetic cubics.
Measurement of deformation and strain field of cantilever beam under forced vibration
Authors: Qian Boxing , Liang Jin , Gong Chunyuan , Li Wenpan
Published: December 2019

Based on digital image correlation and binocular stereo vision, a method is proposed for measuring full field deformation and strain of cantilever beam under forced vibration. First, in the actual measurement, the traditional correlation function with linear model may not be reliable to describe the deformation and light intensity change of subset. Therefore, the radial basis function is introduced into the correlation function to specify the weight of each pixel in the subset, which improves the reliability of the correlation matching. Second, the rigid motion of the excitation source is monitored by sticking a marker at the fixed end. By measuring the position of the marker in the process of vibration, the motion direction of the excitation source can be obtained and then define the new Z-axis along the motion direction. After transformation of the coordinate system, the pure deformation at any position of the beam surface is equal to the displacement at that point minus the displacement of the excitation source. Finally, the deformation and maximum principal strain field of cantilever beam under sinusoidal excitation at different frequencies is compared and analyzed. The method can provide a reference for the deformation measurement under forced vibration.
Jacobi-Maupertuis Randers-Finsler metric for curved spaces and the gravitational magnetoelectric effect
Authors: Chanda Sumanto , Gibbons G. W. , Guha Partha , Maraner Paolo , Werner Marcus C.
Published: December 2019

In this paper, we return to the subject of Jacobi metrics for timelike and null geodesics in stationary spacetimes, correcting some previous misconceptions. We show that not only null geodesics but also timelike geodesics are governed by a Jacobi-Maupertuis type variational principle and a Randers-Finsler metric for which we give explicit formulas. The cases of the Taub-NUT and Kerr spacetimes are discussed in detail. Finally, we show how our Jacobi-Maupertuis Randers-Finsler metric may be expressed in terms of the effective medium describing the behavior of Maxwell’s equations in the curved spacetime. In particular, we see in very concrete terms how the gravitational electric permittivity, magnetic permeability, and magnetoelectric susceptibility enter the Jacobi-Maupertuis Randers-Finsler function.
Radio frequency filter for an enhanced resolution of inelastic electron tunneling spectroscopy in a combined scanning tunneling- and atomic force microscope
Authors: Peronio Angelo , Okabayashi Norio , Griesbeck Florian , Giessibl Franz
Published: December 2019

The combination of inelastic electron tunneling spectroscopy (IETS), also used for IET spectrum based on scanning tunneling microscopy with atomic force microscopy (AFM) enables us to measure the vibrational energies of a single molecule along with the force exerted by the tip of a microscope, which deepens our understanding on the interaction between the tip and the molecule on a surface. The resolution of IETS is a crucial factor in determining the vibrational energies of a molecule. However, radio frequency (RF) noise from the environment significantly deteriorates the resolution. We introduce an RF noise filtering technique, which enables high resolution IETS while maintaining uncompromised AFM performance, demonstrated by vibrational measurements of a CO molecule on a copper surface.
Gyrokinetic full-f particle-in-cell simulations on open field lines with PICLS
Authors: Boesl M. , Bergmann A. , Bottino A. , Coster D. , Lanti E. , Ohana N. , Jenko F.
Published: December 2019

While in recent years gyrokinetic simulations have become the workhorse for theoretical turbulence and transport studies in the plasma core, their application to the edge and scrape-off layer (SOL) region presents significant challenges. In particular, steep density and temperature gradients as well as large fluctuation amplitudes call for a “full-f” treatment. To specifically study problems in the SOL region, the gyrokinetic particle-in-cell (PIC) code PICLS has been developed. The code is based on an electrostatic full-f model with linearized field equations and uses kinetic electrons. Here, the well-studied parallel transport problem during an edge-localized mode in the SOL shall be investigated for one spatial dimension. The results are compared to previous gyrokinetic continuum and fully kinetic PIC simulations and show good agreement.
Enhanced co-deformation of a heterogeneous nanolayered Cu/Ni composite
Authors: Wang Yaodong , Li Jianjun , Lu Wenjun , Yuan Fuping , Wu Xiaolei
Published: December 2019

Nanolayered metallic composites have attracted intensive scientific interests due to their ultrahigh strength. However, the deformation incompatibility among the component layers with high mechanical contrast leads to extremely low tensile ductility in the nanolayered composites, which is a great setback for their engineering applications. Here, by molecular dynamics simulations, we show that a heterogeneous nanolayered design by combining 2.5 nm and 24 nm Cu/Ni bilayers in a composite in an appropriate way can promote the dislocation activity of the hard phase, i.e., the Ni layers. In the new heterogeneous structure, each 24 nm Cu or Ni layer is coated on both surfaces by one 2.5 nm Cu/Ni bilayer. The simulations show that the dislocations in the 24 nm Ni layers can nucleate and glide almost synchronously with those in the 24 nm Cu layers. The enhanced dislocation activities are attributed to the presence of the 2.5 nm Cu layer that can promote the dislocation nucleation and motion in the 24 nm Ni layer by forming more nodes in the dislocation network of the interface.
Large scale instabilities in coaxial air-water jets with annular air swirl
Authors: Kumar Abhijeet , Sahu Srikrishna
Published: December 2019

The aim of this paper is to characterize large-scale instabilities during the primary breakup process in liquid centered coaxial air-water jets. The interest here is to investigate the role of annular air swirl on such instabilities. A coaxial airblast atomizer that incorporates an axial swirler is considered for this purpose. The atomizer was operated in a wide range of the Weber number, Weg(80–958), momentum flux ratio, M(1–26), and air swirl strength, S(0–1.6). High-speed shadowgraphic images of the primary jet breakup process were recorded. Proper orthogonal decomposition (POD) analysis of the time-resolved images was performed for each operating condition. The 2nd and 3rd POD modes depicted some universal spatial features which refer to large scale instabilities. Three different dominant large scale instabilities were identified, viz., jet flapping, wavy breakup, and explosive breakup, for the entire range of the injector operating condition either in the presence or absence of air swirl. It was found that jet flapping (referred to as the lateral oscillation of the tail end of the jet) is the dominant mode of jet instability for a lower range of M, while explosive jet breakup (referred to as the radial expansion of the jet) governs jet breakup unsteadiness for a higher range of M. The wavy or sinuous mode of breakup is a secondary mechanism relevant under low M conditions. The mechanisms of large scale instabilities and the role of air swirl in that context are explained based on the Fourier analysis of the temporal coefficients of the corresponding POD modes.
Effect of the interface morphology on the lateral electron transport in (001) GaP/Si heterostructures
Authors: Ostheim L. , Klar P. J. , Moryson Y. , Rohnke M. , Beyer A. , Volk M. , Munde M. , Stolz W. , Volz K.
Published: December 2019

We study the magnetotransport properties along the interface of various epitaxial (001) GaP/Si heterostructures of different interface morphologies. The samples are grown by metal-organic vapor-phase epitaxy exploring different approaches for optimizing the interface for device applications. We apply magnetic fields up to 10 T and temperatures between 1.5 and 300 K in the measurement. We alternate Ar-ion-beam etching for reducing the thickness of the GaP layer and transport measurements in order to distinguish transport paths in the bulk of the materials and at the interface. The transport behavior is correlated with structural properties obtained by secondary ion mass spectroscopy, atomic-force microscopy, and scanning transmission electron microscopy. We find a conducting path along the interface that correlates with the formation of antiphase boundaries at the interface.
Effects of upstream perturbations on the solution of the laminar and fully turbulent boundary layer equations with pressure gradients
Authors: Vaquero J. , Renard N. , Deck S.
Published: December 2019

The aim of this work is to contribute to the understanding of sensitivity of boundary layers to the upstream boundary condition and history effects for both laminar and fully turbulent states in equilibrium conditions as well as some nonequilibrium turbulent boundary layers. Solutions of the two-dimensional boundary layer equations are obtained numerically for this study together with the Reynolds-averaged Navier-Stokes approach for turbulence modeling. The external pressure gradient is imposed through an evolution of the external velocity of the form Ue∝(x−x0)m, and boundary layers are initialized from a profile giving a perturbed shape factor. It is found that laminar boundary layers require very long distances for convergence toward the nondisturbed profiles in terms of the initial boundary layer thickness (∼104δin) and that this distance is dependent on m. In turbulent boundary layers, much shorter distances, although still large (∼102δin), are observed and they are also dependent on m. The maximum adverse pressure gradient for which convergence to a reference solution is possible is also studied finding that there is no limit for attached laminar boundary layers, whereas turbulent boundary layers do not converge once they are out of equilibrium. The convergence distances in turbulent boundary layers are also studied in terms of the turnover length (δUe+) because it has been shown to be more appropriate to refer the convergence distance to this length rather than the boundary layer thickness. The values for convergence using this criterion are extended to pressure gradient boundary layers. Moreover, an equivalent criterion is proposed and studied for laminar boundary layers based on the viscous characteristic time.
Acoustic tunable metamaterials based on anisotropic unit cells
Authors: Bai Lin , Song Gang Yong , Jiang Wei Xiang , Cheng Qiang , Cui Tie Jun
Published: December 2019

We propose a tunable acoustic metamaterial based on anisotropic elements. By changing the incident angle or rotating the unit cell, the refractive index can be tuned continuously. Such an acoustic metamaterial element can be used to design and fabricate tunable gradient-index lenses, such as fundamental functional lenses, convergent lens, divergent lens, and deflection lens. These functions can be switched in real time without changing the physical structure. A prototype of the acoustic lens is fabricated by using three-dimensional printing technology, and the regulatory mechanism is implemented to testify its versatility. Our finding opens an avenue for designing tunable acoustic metamaterials and is expected to have wide applications in acoustic devices.
The Riemann problem of selfsimilar ZND model for the pressure gradient system in gas dynamical combustion
Authors: Liu Yujin , Sheng Wancheng
Published: December 2019

In this paper, we construct all solutions of the Riemann problem of the self-similar Zeldovich-von Neumann-Döring (SZND) combustion model for the pressure gradient system in gas dynamics. By investigating the temperatures along the SZND burning solutions, we prove that all the detonation solutions of the Chapman-Jouguet model are the limits of the solutions as the reaction rate goes to infinity.
Field-induced nucleation switching in binary ovonic threshold switches
Authors: Lee Sangmin , Yoo Jongmyung , Park Jaehyuk , Hwang Hyunsang
Published: December 2019

In this study, we investigate the initial electroforming and electrically driven threshold switching characteristics of a binary boron-tellurium-based ovonic threshold switch (OTS) device using field-induced nucleation theory and related material parameters. First, an analysis of the current-voltage characteristics of devices with various electrode areas shows that the OTS device exhibits filamentary switching, consistent with the field-induced nucleation framework. Further, we find that the OFF-state current depends on the device area, whereas the hold current remains constant regardless of the device area, indicating that the ON-state current flows through a local conduction path. For verifying field-induced nucleation phenomena in the forming and subsequent switching of the OTS device, we apply constant voltage pulses and measure the delay time required for electrical switching of the device. During both forming and switching processes, the switching time is exponential in inverse voltage with different nucleation energy (W0) values; W0 for forming is larger than that for switching. To verify this analysis, incremental voltage pulses with various pulse widths are also applied to confirm the relation between the threshold voltage and time. The W0 values for the two types of switching in this analysis are consistent, solidifying our understanding of the critical contribution of nucleation phenomena in OTS. The smaller W0 for switching can be explained by the generation of clusterlike nucleation sites during forming with lower nucleation energy than in the surrounding matrix.
Optical and electrical properties of highly ordered α-, γ- and α + γ-MnS films deposited by reactive sputtering technique
Authors: Tiwari Pranjala , Jaiswal Jyoti , Chandra Ramesh
Published: December 2019

In this article, we have studied the detailed electrical and optical characteristics of crystalline α-, γ-, and α + γ-manganese sulfide (MnS) thin films. Highly ordered thin films of α-, γ-, and α + γ-MnS were prepared by direct current reactive sputtering on glass substrates at different substrate temperatures (room temperature to 400 °C) while maintaining other parameters at optimized values. The X-ray diffraction measurement revealed the synthesis of γ-, α + γ-, and α-phase of MnS thin films with preferred orientations (002), (002) + (200), and (200), respectively. The morphological and topographical results demonstrated that the particle size as well as the average roughness of MnS samples varied as a linear function of the substrate temperature. The x-ray photoelectron spectroscopy study revealed that the γ-MnS sample prepared at room temperature has the lowest oxygen related vacancy (12.7%). The optical characteristics such as refractive index n, extinction coefficient k, and optical bandgap Eg are determined in the broad wavelength range of 246–688 nm using spectroscopic ellipsometry. Moreover, the nonlinear refractive index n2 and the third-order nonlinear optical susceptibility χ(3) are determined using the Tichy–Ticha relation and Wemple–Didomenico parameters. The ratio of the carrier concentration to the effective mass N/m* has also been determined, indicating best electrical properties for γ-MnS films. The current research on the optical and electrical properties of highly ordered α-, γ-, and α + γ-MnS thin films is expected to have a significant impact on advanced optoelectronic, photonic, and energy applications.
Spin-wave frequency division multiplexing in an yttrium iron garnet microstripe magnetized by inhomogeneous field
Authors: Zhang Zhizhi , Vogel Michael , Holanda José , Jungfleisch M. Benjamin , Liu Changjiang , Li Yi , Pearson John E. , Divan Ralu , Zhang Wei , Hoffmann Axel , Nie Yan , Novosad Valentyn
Published: December 2019

Spin waves are promising candidates for information processing and transmission in a broad frequency range. In the realization of magnonic devices, the frequency related division of the spin waves is a critical function for parallel information processing. In this work, we demonstrate a proof-of-concept spin-wave frequency division multiplexing method by magnetizing a homogeneous magnetic microstripe with an inhomogeneous field. The symmetry breaking additional field is introduced by a Permalloy stripe simply placed in lateral proximity to an yttrium iron garnet waveguide. Spin waves with different frequencies can propagate independently, simultaneously, and separately in space along the shared waveguide. This work demonstrates one potential way for parallel information transmission and processing in magnonics.
RPA natural orbitals and their application to post-Hartree-Fock electronic structure methods
Authors: Ramberger Benjamin , Sukurma Zoran , Schäfer Tobias , Kresse Georg
Published: December 2019

We present a method to approximate post-Hartree-Fock correlation energies by using approximate natural orbitals obtained by the random phase approximation (RPA). We demonstrate the method by applying it to the helium atom, the hydrogen and fluorine molecule, and to diamond as an example of a periodic system. For these benchmark systems, we show that RPA natural orbitals converge the MP2 correlation energy rapidly. Additionally, we calculated full configuration interaction energies for He and H2, which are in excellent agreement with the literature and experimental values. We conclude that the proposed method may serve as a compromise to reach good approximations to correlation energies at moderate computational cost, and we expect the method to be especially useful for theoretical studies on surface chemistry by providing an efficient basis to correlated wave function based methods.
Abnormal physical behaviors of hafnium diboride under high pressure
Authors: Liang Hao , Peng Fang , Guan Shixue , Tan Lijie , Chen Haihua , Lei Li , He Duanwei , Lu Cheng
Published: December 2019

Hafnium diboride (HfB2) is one of the most promising hard-brittle ceramic materials with unique physical properties. Here, we have synthesized the well-crystallized HfB2 by a high-pressure solid-state reaction and employ in situ high-pressure synchrotron radiation angle-dispersive X-ray diffraction to investigate the size-effect of HfB2. An abnormal physical behavior of HfB2 under high pressure is observed. The microsized HfB2 shows slight anisotropy along a and c axes; however, the nanosized HfB2 reveals a different compression behavior with pressure-induced shell structural transition from a disordered symmetric amorphous shell state to an asymmetric amorphous shell state. In addition, the results indicate that the pressure calibrations are sensitive to the grain size. The present findings offer insights into the physical behaviors of different sized HfB2, which may also provide valuable information for other transition metal borides under high pressure.
Strong electrostatic adsorption of Pt onto SiO2 partially overcoated Al2O3—Towards single atom catalysts
Authors: Bo Zhenyu , McCullough Lauren R. , Dull Samuel , Ardagh M. Alexander , Wang Jie , Notestein Justin
Published: December 2019

It is frequently desired to synthesize supported metal catalysts that consist of very small clusters or single atoms. In this work, we combine strong electrostatic adsorption (SEA) of H2PtCl6 and engineered oxide supports to ultimately produce very small Pt clusters, including a large fraction of single Pt atoms. The supports are synthesized by depositing controlled amounts of SiO2 onto Al2O3 (SiO2@Al2O3) that has been previously grafted with bulky organic templates. After the templates are removed, the oxide supports are largely negatively charged, like SiO2, but have small patches of positively charged Al2O3, derived from the regions previously covered by the template. The overall point of zero charge of these materials decreases from pH 6.4 for 1 cycle of SiO2 deposition to a SiO2-like <2 for materials with more than 5 cycles of SiO2 deposition. SEA at pH 4 on templated SiO2@Al2O3 deposits from 1 wt. % to 0.05 wt. % Pt as the amount of SiO2 increases. Pt loadings drop to near zero in the absence of a template. The resulting Pt nanoparticles are generally <1 nm and have dispersion near 100% by CO chemisorption. Finally, CO DRIFTS shows that the CO nanoparticles become increasingly well defined and have a higher percentage of Pt single atoms as the amount of SiO2 increases on the SiO2@Al2O3 particles. Overall, this method of synthesizing patches of charge on a carrier particle appears to be a viable route to creating extremely highly dispersed supported metal catalysts.
BAlGaN alloys nearly lattice-matched to AlN for efficient UV LEDs
Authors: Williams Logan , Kioupakis Emmanouil
Published: December 2019

The lattice mismatch between AlGaN and AlN substrates limits the design and efficiency of UV light-emitting diodes, but it can be mitigated by the coincorporation of boron. We employ hybrid density functional theory to investigate the thermodynamic, structural, and electronic properties of BAlGaN alloys. We show that BAlGaN can lattice match AlN with bandgaps that match AlGaN of the same gallium content. We predict that BAlGaN emits transverse-electric polarization for a gallium content of ∼45% or more. Our results indicate that BAlGaN alloys are promising materials for higher efficiency UV optoelectronic devices on bulk AlN substrates.
Highly versatile laboratory X-ray scattering instrument enabling (nano-)material structure analysis on multiple length scales by covering a scattering vector range of almost five decades
Authors: Bolze Joerg , Gateshki Milen
Published: December 2019

A compact laboratory X-ray scattering platform that uniquely enables for high-performance ultra-small-angle X-ray scattering (USAXS), small- and wide-angle X-ray scattering (SAXS/WAXS), and total scattering (atomic pair distribution function analysis; PDF) experiments was developed. It covers Bragg spacings from sub-Angstroms to 1.7 μm, thus allowing the analysis of dimensions and complex structures in (nano-)materials on multiple length scales. The accessible scattering vector q-range spans over almost five decades (qmin = 0.0036 nm−1, qmax = 215 nm−1), without any gaps. Whereas SAXS is suitable to characterize materials on a length scale of 1–100 nm, with USAXS, this range can be significantly extended to the micrometer range. On the other end, from WAXS and particularly from PDF measurements, information about the local atomic order and disorder can be obtained. The high performance, exceptional versatility, and ease-of-use of the instrument are enabled by a high-resolution 2-circle goniometer with kinematic mounts, a modular concept based on prealigned, quickly interchangeable X-ray components, and advanced detector technology. For USAXS measurements, a modified Bonse-Hart experimental setup with single crystal collimator and analyzer optics is used. SAXS/WAXS measurements are enabled by focusing optics, an evacuated beam path, and a 2D detector. For total scattering experiments, a high-energy X-ray source is used in combination with a hybrid pixel array detector that is based on a CdTe sensor for the highest counting efficiency. To ensure high resolution and sensitivity in these various applications, special care is taken to suppress any type of background scattering signal. The high resolution that can be achieved with the USAXS collimation system is demonstrated on a set of monodisperse, colloidal silica dispersions and derived colloidal crystals, with particle diameters in the range of hundreds of nanometers up to 1.6 µm. USAXS and SAXS results are shown to be consistent with those obtained by static light scattering (SLS) and dynamic light scattering. It is demonstrated that the obtainable USAXS data bridge the gap in q between SAXS and SLS. The capabilities of the instrument to acquire high-quality total scattering data for PDF analysis are demonstrated on amorphous SiO2 nanoparticles as well as on NaYF4 upconversion nanocrystals. To the best of our knowledge, it is for the first time that we present a single laboratory instrument that enables measurements of high-quality X-ray scattering data within such a wide q-range, by combining four complementary elastic X-ray scattering techniques. The modular design concept of the instrument allows for incremental improvements as well as to add more applications in the future.
Flattening van der Waals heterostructure interfaces by local thermal treatment
Authors: Boddison-Chouinard Justin , Scarfe Samantha , Watanabe K. , Taniguchi T. , Luican-Mayer Adina
Published: December 2019

Fabrication of custom-built heterostructures based on stacked 2D materials provides an effective method to controllably tune electronic and optical properties. To that end, optimizing fabrication techniques for building these heterostructures is imperative. A common challenge in layer-by-layer assembly of 2D materials is the formation of bubbles at atomically thin interfaces. We propose a technique for addressing this issue by removing the bubbles formed at the heterostructure interface in a custom-defined area using the heat generated by a laser equipped with raster scanning capabilities. We demonstrate that the density of bubbles formed at graphene-ReS2 interfaces can be controllably reduced using this method. We discuss an understanding of the flattening mechanism by considering the interplay of interface thermal conductivities and adhesion energies between two atomically thin 2D materials.
Intense vortex high-order harmonics generated from laser-ablated plume
Authors: Singh M. , Fareed M. A. , Laramée A. , Isgandarov E. , Ozaki T.
Published: December 2019

In this study, we demonstrate intense extreme-ultraviolet optical vortices generated using laser-ablation plume as the nonlinear medium. We used two types of plumes that are known to generate intense high-order harmonics for driving lasers with Gaussian beam profiles, but through different mechanisms, namely, carbon (diatomic carbon molecules) and tin (resonance with the autoionizing state). We find that the harmonic fluxes for diatomic carbon molecules are similar for Gaussian and vortex driving fields. However, for harmonics from the autoionizing state of tin (∼26.3 eV), the enhancement factor of the resonant harmonic intensity decreases by ∼50% when using the vortex driving field. The intense extreme-ultraviolet optical vortices demonstrated in this study will be useful for many applications including a material characterization technique known as optical angular momentum dichroism as well as the spectroscopy of spin-forbidden electronic transitions.
Brain-wide genetic mapping identifies the indusium griseum as a prenatal target of pharmacologically unrelated psychostimulants
Authors: Fuzik Janos , Rehman Sabah , Girach Fatima , Miklosi Andras G. , Korchynska Solomiia , Arque Gloria , Romanov Roman A. , Hanics János , Wagner Ludwig , Meletis Konstantinos , Yanagawa Yuchio , Kovacs Gabor G. , Alpár Alán , Hökfelt Tomas G. M. , Harkany Tibor
Published: December 2019

Significance

Drug abuse during pregnancy carries significant risk for impaired fetal development. Here, we show that episodic exposure to amphetamine, nicotine, or caffeine during pregnancy induces various patterns of neuronal activity in the fetal brain. The indusium griseum, situated parallel to the central surface of the cortical hemispheres, is indiscriminately activated. Herein, psychostimulants preferentially target glutamatergic neurons and delay their differentiation. Particularly, expression of secretagogin, a Ca2+-sensor protein, is deregulated, which is significant because its loss impairs the integration of information that flows along limbic and olfactory circuits. Cumulatively, we describe psychostimulant-sensitive brain regions and unique neuronal subtypes whose developmental delay disrupts circuit wiring such that behavioral abnormalities can manifest in offspring prenatally exposed to psychostimulants.
Solidification and superlubricity with molecular alkane films
Authors: Smith Alexander M. , Hallett James E. , Perkin Susan
Published: December 2019

Significance

An essential step in society’s attempt to reduce energy consumption is to understand and optimize energy dissipation (friction) in mechanical processes. Despite decades of study, one of the most fundamental model systems in the study of friction remains unsolved: the shear of molecular films of simple alkanes between atomically smooth crystalline surfaces. Previous reports of the friction coefficient diverge over three orders of magnitude, and reports that the film solidifies on confinement remain controversial. We perform measurements with control over parameters not previously taken into account, allowing us to reconcile earlier reports. We demonstrate that the alkane films indeed solidify, and yet retain ultralow friction coefficients under certain conditions.
Confinement of surface spinners in liquid metamaterials
Authors: Gorce Jean-Baptiste , Xia Hua , Francois Nicolas , Punzmann Horst , Falkovich Gregory , Shats Michael
Published: December 2019

We show that rotating particles at the liquid–gas interface can be efficiently manipulated using the surface-wave analogue of optical lattices. Two orthogonal standing waves generate surface flows of counter-rotating half-wavelength unit cells, the liquid interface metamaterial, whose geometry is controlled by the wave phase shift. Here we demonstrate that by placing active magnetic spinners inside such metamaterials, one makes a powerful tool which allows manipulation and self-assembly of spinners, turning them into vehicles capable of transporting matter and information between autonomous metamaterial unit cells. We discuss forces acting on a spinner carried by a nonuniform flow and show how the forces confine spinners to orbit inside the same-sign vortex cells of the wave-driven flow. Reversing the spin, we move the spinner into an adjacent cell. By changing the spinning frequency or the wave amplitude, one can precisely control the spinner orbit. Multiple spinners within a unit cell self-organize into stable patterns, e.g., triangles or squares, orbiting around the center of the cell. Spinners having different frequencies can also be confined, such that the higher-frequency spinner occupies the inner orbit and the lower-frequency one circles on the outer orbit, while the orbital motions of both spinners are synchronized.
Efficient nonenzymatic cyclization and domain shuffling drive pyrrolopyrazine diversity from truncated variants of a fungal NRPS
Authors: Berry Daniel , Mace Wade , Grage Katrin , Wesche Frank , Gore Sagar , Schardl Christopher L. , Young Carolyn A. , Dijkwel Paul P. , Leuchtmann Adrian , Bode Helge B. , Scott Barry
Published: December 2019

Nonribosomal peptide synthetases (NRPSs) generate the core peptide scaffolds of many natural products. These include small cyclic dipeptides such as the insect feeding deterrent peramine, which is a pyrrolopyrazine (PPZ) produced by grass-endophytic
Epichloë
fungi. Biosynthesis of peramine is catalyzed by the 2-module NRPS, PpzA-1, which has a C-terminal reductase (R) domain that is required for reductive release and cyclization of the NRPS-tethered dipeptidyl-thioester intermediate. However, some PpzA variants lack this R domain due to insertion of a transposable element into the 3′ end of
ppzA
. We demonstrate here that these truncated PpzA variants utilize nonenzymatic cyclization of the dipeptidyl thioester to a 2,5-diketopiperazine (DKP) to synthesize a range of novel PPZ products. Truncation of the R domain is sufficient to subfunctionalize PpzA-1 into a dedicated DKP synthetase, exemplified by the truncated variant, PpzA-2, which has also evolved altered substrate specificity and reduced
N
-methyltransferase activity relative to PpzA-1. Further allelic diversity has been generated by recombination-mediated domain shuffling between
ppzA-1
and
ppzA-2
, resulting in the
ppzA-3
and
ppzA-4
alleles, each of which encodes synthesis of a unique PPZ metabolite. This research establishes that efficient NRPS-catalyzed DKP biosynthesis can occur in vivo through nonenzymatic dipeptidyl cyclization and presents a remarkably clean example of NRPS evolution through recombinant exchange of functionally divergent domains. This work highlights that allelic variants of a single NRPS can result in a surprising level of secondary metabolite diversity comparable to that observed for some gene clusters.
Functional genetic validation of key genes conferring insecticide resistance in the major African malaria vector,
Anopheles gambiae
Authors: Adolfi Adriana , Poulton Beth , Anthousi Amalia , Macilwee Stephanie , Ranson Hilary , Lycett Gareth J.
Published: December 2019

Resistance in
Anopheles gambiae
to members of all 4 major classes (pyrethroids, carbamates, organochlorines, and organophosphates) of public health insecticides limits effective control of malaria transmission in Africa. Increase in expression of detoxifying enzymes has been associated with insecticide resistance, but their direct functional validation in
An. gambiae
is still lacking. Here, we perform transgenic analysis using the GAL4/UAS system to examine insecticide resistance phenotypes conferred by increased expression of the 3 genes—
Cyp6m2
,
Cyp6p3
, and
Gste2
—most often found up-regulated in resistant
An. gambiae
. We report evidence in
An. gambiae
that organophosphate and organochlorine resistance is conferred by overexpression of GSTE2 in a broad tissue profile. Pyrethroid and carbamate resistance is bestowed by similar
Cyp6p3
overexpression, and
Cyp6m2
confers only pyrethroid resistance when overexpressed in the same tissues. Conversely, such
Cyp6m2
overexpression increases susceptibility to the organophosphate malathion, presumably due to conversion to the more toxic metabolite, malaoxon. No resistant phenotypes are conferred when either
Cyp6
gene overexpression is restricted to the midgut or oenocytes, indicating that neither tissue is involved in insecticide resistance mediated by the candidate P450s examined. Validation of genes conferring resistance provides markers to guide control strategies, and the observed negative cross-resistance due to
Cyp6m2
gives credence to proposed dual-insecticide strategies to overcome pyrethroid resistance. These transgenic
An. gambiae
-resistant lines are being used to test the “resistance-breaking” efficacy of active compounds early in their development.
MiR-381-3p suppresses biological characteristics of cancer in head-neck squamous cell carcinoma cells by targeting nuclear autoantigenic sperm protein (NASP)
Authors: Kong Fanyong , Li Lianhe , Wang Chaoshan , Zhang Qiang , He Shizhi
Published: December 2019

MiR-381-3p and nuclear autoantigenic sperm protein (NASP) have regulatory functions in tumors. Whether NASP is targeted by miR-381-3p to influence biological characteristics of cancer in head-neck squamous cell carcinoma (HNSCC) cells was investigated. StarBase (version 3.0) found that the expression of NASP was increased with the down-regulation of miR-381-3p in laryngocarcinoma tissue, AMC-HN-3，FaDu，HNE-3，and Detroit 562 cell lines. MiR-381-3p could target NASP, reduce the expression of MMP-2 and MMP-9, Vimentin, repress the cell viability, invasion, and migration, and promote the expression of E-cadherin in AMC-HN-3 cells. Overexpressed NASP could increase the viability, migration and invasion rates in AMC-HN-3 cells, which could be partially reversed by overexpressed miR-381-3p. Thus, miR-381-3p targeted and suppressed NASP gene, reduced the viability, migration, invasion, EMT of HNSCC cells, demonstrating that miR-381-3p has the potential to be a therapeutic target in inhibiting the progression of HNSCC.
Leisure‐time physical activity is negatively associated with depression symptoms independently of the socioeconomic status
Authors: Marques Adilson , Peralta Miguel , Gouveia Élvio R. , Martins João , Sarmento Hugo , Gomez‐Baya Diego
Published: December 2019

Objective: There are few studies evaluating the relationship between depression symptoms (DS) and physical activity (PA) considering peoples’ sociodemographic characteristics. This study aimed to analyse the relationship between DS and PA, stratified by sociodemographic characteristics of European adults.

Methods: Participants were 29,285 adults (13,943 men, 47.6%; 15,342 women, 52.4%), aged 50.9 ± 17.4 (50.6 ± 17.3 men, 51.1 ± 17.5 women) from the European Social Survey round 7. DS was assessed with the Centre for Epidemiological Studies Depression Scale (CES‐D8). Leisure‐time PA (LTPA) was self‐reported. The analysed sociodemographic characteristics were sex, age, living place, household members, marital status, income, and educational level. The relationship between DS and PA, stratified by sociodemographic variables, was examined by linear regression models.

Results: Engaging in LTPA was negatively and linearly related to DS, independently of being men or women, being younger, middle or older adult, living in an urban or rural area, having children or not, being single or married, being wealthy or poor, employment status, and to having a lower or a higher education level. Age was the variable with both the least and the greatest effect of LTPA on DS. The least effect of LTPA on DS was observed in younger adults (β = −0.08, 95% CI: −0.11, −0.05) and the greatest effect in retired people (β = −0.33, 95% CI: −0.36, −0.29).

Conclusion: Independently of sociodemographic characteristics, LTPA is associated with DS and can benefit everyone. Public health policies for promoting mental health should include PA promotion as an important strategy for the prevention or treatment of DS.
The hyperbolic Ernst–Maxwell equations in a triangular domain
Authors: Mauersberger Julian
Published: December 2019

In a recent paper, we applied Riemann–Hilbert techniques to analyze the Goursat problem for the hyperbolic Ernst equation, which describes the interaction of two colliding gravitational plane waves. Here we generalize this approach to colliding electromagnetic plane waves in Einstein–Maxwell theory.
GAN for Recommendation System
Authors: Prosvetov A. V.
Published: December 2019

In our day there are many approaches for recommendation generation, however several unsolved problems still exist. In our work we study the potential of Generative Adversarial Networks to generate relevant recommendations and compare the proposed approach with another recommendations system based on neural networks. We found that recommendation system based on GANs can successively compete with state-of-the-art network in the field of recommendation generation and suggest, that GAN recommendation system have high potential.
Optimising the use of ensemble information in numerical weather forecasts of wind power generation
Authors: Stanger J , Finney I , Weisheimer A , Palmer T
Published: December 2019

Electricity generation output forecasts for wind farms across Europe use numerical weather prediction (NWP) models. These forecasts influence decisions in the energy market, some of which help determine daily energy prices or the usage of thermal power generation plants. The predictive skill of power generation forecasts has an impact on the profitability of energy trading strategies and the ability to decrease carbon emissions. Probabilistic ensemble forecasts contain valuable information about the uncertainties in a forecast. The energy market typically takes basic approaches to using ensemble data to obtain more skilful forecasts. There is, however, evidence that more sophisticated approaches could yield significant further improvements in forecast skill and utility. In this letter, the application of ensemble forecasting methods to the aggregated electricity generation output for wind farms across Germany is investigated using historical ensemble forecasts from the European Centre for Medium-Range Weather Forecasting (ECMWF). Multiple methods for producing a single forecast from the ensemble are tried and tested against traditional deterministic methods. All the methods exhibit positive skill, relative to a climatological forecast, out to a lead time of at least seven days. A wind energy trading strategy involving ensemble data is implemented and produces significantly more profit than trading strategies based on single forecasts. It is thus found that ensemble spread is a good predictor for wind electricity generation output forecast uncertainty and is extremely valuable at informing wind energy trading strategy.