bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-term Effects of Unilateral and Bilateral Otitis Media and Myringotomy on Long-Latency Verbal and Non-Verbal Auditory-Evoked Potentials
Authors: Sanfins Milaine Dominici , Donadon Caroline , Borges Letícia Reis , Skarzynski Piotr H. , Colella-Santos Maria Francisca
Published: January 2020

Introduction Otitis media (OM) is considered one of the most common reasons patients seek medical care in childhood. The fluctuating nature of hearing loss in cases of OM leads to irregular sound stimulation of the central auditory nervous system.

Objectives To analyze the long-latency auditory-evoked potential (LLAEP) by verbal and nonverbal sounds in children with a history of OM in the first six years of life.

Methods A total of 106 schoolchildren participated in the study, 55 females and 51 males, aged between 8 and 16 years, who were divided into 3 groups: the control group (CG), the bilateral experimental group (BEG), and the unilateral experimental group (UEG). All children underwent a complete audiological evaluation (audiometry, logoaudiometry and immitance testing) and an electrophysiological evaluation (LLAEP with toneburst stimulus – LLAEP-TB, and LLAEP with speech stimulus – LLAEP-S).

Results Both study groups (BEG and UEG) presented a statistically lower performance (p < 0.005) when compared with the CG regarding all of the electrophysiological tests with the prolongation of the latency values and decrease in the amplitude values: LLAEP-TB (BEG: latency - N1, P2, N2 [females] and P300, amplitude - N1 and P2), LLAEP-S (BEG: latency - P2 and N2 [females], amplitude - P2 /UEG: latency - P2 and P300, amplitude: N1 and P2).

Conclusion Children who had suffered secretory OM in the first six years of life and who had undergone myringotomy for the placement of a ventilation tube, either unilaterally or bilaterally, presented worse performance in their electrophysiological responses to verbal and nonverbal LLAEPs.
Placas anteriores são mais efetivas do que parafusos iliossacrais na fixação da articulação sacroilíaca? Estudo Biomecânico
Authors: Goldsztajn Flavio , Mariolani Jose Ricardo L. , Belangero William Dias
Published: January 2020

Introdução Usualmente, as luxações sacroilíacas são tratadas com parafusos iliossacrais ou com placas anteriores à articulação sacroilíaca (ASI). Este estudo compara a rigidez e carga máxima suportada pelos dois tipos de fixações acima citados, utilizando pelves sintéticas.

Método Dez pelves sintéticas foram divididas em dois grupos (n = 5). No grupo denominado PlaCF, a ASI foi fixada com duas placas anteriores. No grupo ParCF, a ASI foi fixada com dois parafusos iliossacrais no corpo da primeira vertebra sacral (S1). A rigidez e carga máxima suportada por cada montagem realizada, foi mensurada. A análise estatística foi realizada através do teste U de Mann-Whitney (p < 0.05 foi considerado estatisticamente significativo para todas as análises).

Resultados A carga máxima suportada até a falha da fixação pelos grupos PlaCF e ParCF foram respectivamente 940 ± 75 N e 902 ± 56 N, não havendo diferença estatística entre eles. A rigidez obtida pelo grupo ParCF foi maior e com diferença estatística em relação ao grupo PlaCF (68.6 ± 11.1 N/mm e 50 ± 4.0 N/mm respectivamente).

Conclusão Apesar da menor rigidez obtida no grupo PlaCF, as placas anteriores à ASI podem ser uma ótima opção no tratamento da luxação sacroilíaca quando os parafusos iliossacrais não puderem ser utilizados. Outros estudos são necessários para detectar possíveis diferenças entre os dois procedimentos do ponto vista cirúrgico e clínico.
Operative versus Non-Operative Management of Traumatic Thoracolumbar Injuries according to the AO Spine Thoracolumbar Spine Injury Classification System
Authors: Joaquim Andrei F.
Published: January 2020

Introduction The AOSpine Thoracolumbar Spine Injury Classification (AOSTSIC) system has been proposed to better characterize injury morphologies and improve the classification of thoracolumbar (TL) spine trauma. However, the indications for surgical treatment according to the AOSTSIC system are still debated. Additionally, the proposed Thoracolumbar AOSpine Injury Score (AOSIS) is quite complex, which may preclude its use in daily practice. The objective of this review is to discuss the AOSTSIC system and its indications for initial nonoperative versus surgical management of acute TL spine trauma.

Methods We analyzed the literature for each injury type (and subtype, when pertinent) according to the AOSTSIC system as well as their potential treatment options.

Results Patients with AOSTSIC subtypes A0, A1, and A2 are neurologically intact in the vast majority of the cases and initially managed nonoperatively. The treatment of A3- and A4-subtype injuries (burst fractures) in neurologically-intact patients is still debated with great controversy, with initially nonoperative management being considered an option in select patients. Surgery is recommended when there are neurological deficits or failure of nonoperative management, with the role of magnetic resonance findings in the Posterior Ligamentous Complex (PLC) evaluation still being considered controversial. Injuries classified as type B1 in neurologically-intact patients may be treated, initially, with nonoperative management, provided that there are no ligamentous injury and non-displacing fragments. Due to severe ligamentous injury, type-B and type-C injuries should be considered as unstable injuries that must be surgically treated, regardless of the neurological status of the patient.

Conclusions Until further evidence, we provided an easy algorithm-based guide on the spinal trauma literature to help surgeons in the decision-making process for the treatment of TL spine injuries classified according to the new AOSTSIC system.
Estudo biomecânico in vitro das suturas em “oito” e de Kessler de tendões flexores de porcos
Authors: Kawachi Diogo Thomaz , Deienno Francisco Simões , Varanda Denis , Cortopassi Andrea Christina , Sardenberg Trajano
Published: January 2020

Objetivo Avaliar as propriedades biomecânicas dos pontos de sutura tendinosa em “oito” e de Kessler.

Métodos Tendões flexores dos dedos de membros superiores de porcos foram divididos em dois grupos com suturas triplas centrais em “oito” (seis passagens) e de Kessler (duas passagens) associadas a suturas periféricas contínuas simples, e submetidos a ensaios mecânicos longitudinais contínuos, obtendo-se as propriedades mecânicas de carga máxima e de energia na carga máxima.

Resultados As médias da carga máxima e da energia na carga máxima na sutura em “8” foram de 63,4 N e 217,3 Nmm, respectivamente; na sutura de Kessler, os valores foram de 34,19 N e 100,9 Nmm, respectivamente. A análise estatística indicou que o ponto em “oito” é superior mecanicamente ao ponto de Kessler.

Conclusões Nas condições deste experimento e no tendão flexor de dedo de membro superior de porcos, o triplo ponto em “oito” (seis passagens) é mais resistente do que o ponto de Kessler (duas passagens). O triplo ponto em “oito”, com seis passagens, permite movimentação ativa na reabilitação imediata de reparo de tendão flexor de dedo de membro superior com pouco risco de ruptura ou espaçamento na sutura.
Does A Vertebra Fracture Cause A Tumor? A Dorsolumbar Paraspinal Desmoid Tumor: Case Report
Authors: Ataizi Zeki Serdar , Simsek Gulay , Ataizi Fulya Colak , Ercan Serdar
Published: January 2020

Extraabdominal desmoid tumors are uncommon soft-tissue tumors. The etiology of the tumor is still unclear. Injury is one of the etiological factors of soft-tissue tumors. A 41-year-old female patient who had a traumatic vertebral body fracture on the thoracic spine was treated conservatively. Two and a half years later, she presented a painful, palpable swelling on the thoracolumbar region. In the present report, was discuss the patient, who underwent a surgery to remove the desmoid tumor (aggressive fibromatosis), within the context of the current literature. The literature on desmoid tumor caused by a trauma is rare. This is the first case that demonstrates an extraabdominal desmoid tumor following a spinal fracture. The swelling on the region of the trauma must be examined carefully and desmoid tumor must be kept in mind as a possible diagnosis.
Light-induced capacitance enhancement and successive carrier escape in InGaN/GaN multiple quantum wells
Authors: Yoo Jengsu , Nam Yoonsung , Kim Tae-Soo , Jung Gunwoo , Song Jung-Hoon , Chang Soo-Kyung
Published: January 2020

We observed large enhancement of capacitance with strong voltage sensitivity in InGaN/GaN multiple quantum wells with additional laser illuminations. We have found that the observed negative differential capacitance and its related capacitance peaks in the capacitance-voltage profile are due to the photogenerated charge separation and accumulation at the well/barrier interfaces and its subsequent carrier escape by the applied forward bias. By analyzing temperature dependent photocurrent spectra simultaneously, it is shown that photocarrier separation and strong carrier escape simultaneously occur in an individual quantum well. We can analyze the contribution of a single individual quantum well to the total capacitance of the device, resulting from the nanometer scale carrier separation and accumulation, and clarify the detailed process of accumulation and escape of carriers in the respective quantum wells.
Controlled thermoelectric performance in a nanojunction: A theoretical approach
Authors: Chakraborty Suvendu , Maiti Santanu K.
Published: January 2020

A proposal is given to get enhanced thermoelectric performance and its suitable tuning in a quantum wire coupled to a nanoring. The ring is subjected to an in-plane electric field, which is the key controlling parameter of our study. Exploiting the effect of asymmetry in transmission probability and emphasizing the fact that disorderness of the system helps to increase the asymmetric nature, here we suggest two easily adjustable tuning parameters: in-plane electric field and the coupling between the wire and the ring. In the presence of an electric field, the system behaves like an ordered-disordered separated one, which exhibits nontrivial signatures in thermoelectric effects. The wire-ring coupling also plays an important role in regulating the thermoelectric efficiency of the system. We critically investigate all the characteristic features using the Landauer prescription within a tight-binding framework based on Green’s function formalism. We hope that the present analysis may provide some suitable hints for constructing efficient thermoelectric devices at the nanoscale level.
High-temperature analysis of the transverse dynamical two-point correlation function of the XX quantum-spin chain
Authors: Göhmann Frank , Kozlowski Karol K. , Suzuki Junji
Published: January 2020

We analyze the transverse dynamical two-point correlation function of the XX chain by means of a thermal form factor series. The series is rewritten in terms of the resolvent and the Fredholm determinant of an integrable integral operator. This connects it with a matrix Riemann-Hilbert problem. We express the correlation function in terms of the solution of the matrix Riemann-Hilbert problem. The matrix Riemann-Hilbert problem is then solved asymptotically in the high-temperature limit. This allows us to obtain the leading high-temperature contribution to the two-point correlation function at any fixed space-time separation.
Investigating extraordinary optical transmission and sensing performance through periodic bilayer magneto-plasmonic structure
Authors: Tajik Shaziyeh , Atlasbaf Zahra
Published: January 2020

This paper proposes the phenomenon of extraordinary optical transmission via a magneto-plasmonic nanostructure, which combines magnetic and plasmonic functionalities. The structure includes an active magnetic film magnetized perpendicular to its surface and a plasmonic metal film, perforated with subwavelength circular annular arrays, with a ring placed in the middle of each annular circle. We use the finite element method and the finite-difference time-domain method for simulation of the structure. Numerical analysis shows an improvement in the Faraday rotation and optical transmission, simultaneously, in a magneto-plasmonic structure based on a silver- and bismuth-substituted ferrite garnet. Simultaneous improvement is achieved by coupling the TE and TM waveguide-plasmon modes. The amount of enhancement is adjusted by changing the dimensions, the periodicity of the hole arrays, and the refractive index of the materials filled in the holes. The influence of excitation of the two kinds of plasmon modes and the application of the external magnetic field are used to enhance the optical response. The resulting investigation shows two resonance peaks in the near-infrared range of the Faraday effect spectrum. Because of the strong Faraday rotation coinciding with the dual-band transmission of approximately 90%, the maximum figure of merit can also be obtained. Finally, this structure is investigated as a sensor in different reflective indexes from 1 to 1.5 RIU, and sensitivity of 45.97 nm/RIU was achieved. The potential applications of these nanostructures include, for example, subwavelength optics, optoelectronic devices, biosensing devices, and magneto-optical devices.
Lane formation in driven pair-ion plasmas
Authors: Sarma Upasha , Baruah Swati , Ganesh R.
Published: January 2020

Lane formation dynamics of driven 2D pair-ion plasmas is investigated in underdamped cases. Extensive Brownian dynamics simulation is performed to study the behavior of the system in the presence of both constant and time-varying external electric fields. Lanes are found to form when like particles move along or opposite to the applied field direction. The lane order parameter has been implemented to detect phase transition. For the constant external field case, investigations are performed at different field strengths, to analyze the phase transition from a disordered to a lane state. It is observed that in this case, the electric field strength must exceed a critical value above which lanes are formed distinctly. For the case of the oscillating electric field, the frequency of the external oscillating field is found to control the lane formation phenomenon. We show that if the frequency of the external field exceeds a critical value, the system exhibits a transition back to the disordered state. A simple method for calculating the critical field strength provides quantitative agreement between the calculated and simulated values of the critical field strength for the case of the constant external electric field. The calculated value of the critical frequency agrees qualitatively with our simulation results for the oscillating external electric field case. A comparative study with the overdamped case has been performed, which suggests that the critical field strength corresponding to the phase transition point is higher for the underdamped case as compared to the overdamped one.
Using machine learning to predict extreme events in the Hénon map
Authors: Lellep Martin , Prexl Jonathan , Linkmann Moritz , Eckhardt Bruno
Published: January 2020

Machine Learning (ML) inspired algorithms provide a flexible set of tools for analyzing and forecasting chaotic dynamical systems. We analyze here the performance of one algorithm for the prediction of extreme events in the two-dimensional Hénon map at the classical parameters. The task is to determine whether a trajectory will exceed a threshold after a set number of time steps into the future. This task has a geometric interpretation within the dynamics of the Hénon map, which we use to gauge the performance of the neural networks that are used in this work. We analyze the dependence of the success rate of the ML models on the prediction time T, the number of training samples NT, and the size of the network Np. We observe that in order to maintain a certain accuracy, NT∝exp⁡(2hT) and Np∝exp⁡(hT), where h is the topological entropy. Similar relations between the intrinsic chaotic properties of the dynamics and ML parameters might be observable in other systems as well.
Algorithms to apply dihedral-angle constraints in molecular or stochastic dynamics simulations
Authors: Pechlaner Maria , van Gunsteren Wilfred F.
Published: January 2020

Various algorithms to apply dihedral-angle constraints in molecular dynamics or stochastic dynamics simulations of molecular systems are presented, investigated, and tested. They use Cartesian coordinates and determine the Lagrangian multipliers necessary for maintaining the constraints iteratively. The most suitable algorithm to maintain a dihedral-angle constraint is numerically compared to the alternative to use distance constraints to this end. It can easily be used to obtain a potential of mean force along a dihedral-angle coordinate.
Measurement of sub-2 nm stable clusters during silane pyrolysis in a furnace aerosol reactor
Authors: Vazquez-Pufleau Miguel , Wang Yang , Biswas Pratim , Thimsen Elijah
Published: January 2020

The initial stages of particle formation are important in several industrial and environmental systems; however, the phenomenon is not completely understood due to the inability to measure cluster size distributions. A high resolution differential mobility analyzer with an electrometer was used to map out the early stages of Si particle formation from pyrolysis of SiH4 in a furnace aerosol reactor. We detected for the first time subnanometer stable clusters from silane pyrolysis, and the diameter was measured to be about 0.7 nm. This diameter is within the range of probable sizes that the reported families of critical silane clusters could have based on their actual molecular structure. The size distributions of negative clusters are also mapped out. In addition, gas chromatography mass spectrometry, and transmission electron microscopy characterizations of the clusters and primary particles are used to assess their mechanistic roles in aerosol dynamics of the initial stages of particle formation.
Generation of ultra-energetic ions by interaction of petawatt lasers with micrometer-scale foils
Authors: Héron A. , Adam J. C. , Mora P.
Published: January 2020

The interaction of an ultraintense (2 × 1021 W/cm2) and ultrashort (18 fs) laser pulse with micrometer-scale aluminum foils is studied via the use of two and three dimensional (2D and 3D) particle-in-cell simulations. One shows that for a plane target with a steep density step, total (collisional and collisionless) absorption is weak. On the other hand, the use of structured targets (gratings in our case) or the presence of a sharp density gradient at the front of the slab allows a better coupling between the laser pulse and the target, and this yields a high absorption rate and ultraenergetic aluminum ions (in the 1 GeV range) generated by target normal sheath acceleration. By changing the characteristics of the grating, it is possible to control, to some extent, the absorption rate and the cutoff of the ion spectrum. It is also shown that a relatively simple model based on the adiabatic self-similar expansion of the target in the ultrarelativistic limit provides reasonable agreement with the simulation results. Finally, the comparison of 2D and 3D results for the interaction with gratings shows that 2D simulations accurately describe the absorption by 2D gratings but, on the other hand, they significantly overestimate the ion-spectrum cutoff.
Modification of turbulent boundary layer coherent structures with drag reducing polymer solution
Authors: Farsiani Yasaman , Saeed Zeeshan , Jayaraman Balaji , Elbing Brian R.
Published: January 2020

The modification of dominant coherent structures that extend through the log-region of a drag reduced turbulent boundary layer is studied via examination of two-point correlations from time-resolved particle-image-velocimetry. Measurements were acquired in polymer oceans (uniform concentration) at drag reduction levels corresponding to the low drag reduction regime (<40%) and the high drag reduction (HDR) regime (>40%) and at an intermediate level (46%). The mean velocity profiles and two-point correlations were compared with those of water (Newtonian, DR = 0%). These results show that, with increasing drag reduction, the inclination of these dominant coherent structures decreases, their streamwise extent increases, and the fluctuations in the correlations are suppressed (especially at HDR). These observations are examined in comparison with the coherent structure literature (Newtonian and polymeric).
Spectral analysis and computation for homogenization of advection diffusion processes in steady flows
Authors: Murphy N. B. , Cherkaev E. , Zhu J. , Xin J. , Golden K. M.
Published: January 2020

Advective diffusion plays a key role in the transport of salt, heat, buoys, and markers in geophysical flows, in the dispersion of pollutants and trace gases in the atmosphere, and even in the dynamics of sea ice floes influenced by winds and ocean currents. The long time, large scale behavior of such systems is equivalent to an enhanced diffusion process with an effective diffusivity matrix D*. Three decades ago, a Stieltjes integral representation for the homogenized matrix, involving a spectral measure of a self-adjoint operator, was developed. However, analytical calculations of D* have been obtained for only a few simple flows, and numerical computations of the effective behavior based on this spectral representation have apparently not been attempted. We overcome these limitations by providing a mathematical foundation for the computation of Stieltjes integral representations of D*. We explore two different approaches and for each approach we derive new Stieltjes integral representations and rigorous bounds for the symmetric and antisymmetric parts of D*, involving the molecular diffusivity and a spectral measure μ of a self-adjoint operator that depends on the characteristics of a randomly perturbed periodic flow. In discrete formulations of each approach, we express μ explicitly in terms of standard (or generalized) eigenvalues and eigenvectors of Hermitian matrices. We develop and implement an efficient numerical algorithm that combines beneficial numerical attributes of each approach. We use this method to compute the effective behavior for model flows and relate spectral characteristics to flow geometry and transport properties.
Thermal imaging of the structural damping induced by an acoustic black hole
Authors: Durand-Texte T. , Pelat A. , Penelet G. , Gautier F. , Sécail-Géraud M.
Published: January 2020

An Acoustic Black Hole (ABH) is a passive and efficient way to control the flexural vibrations of beams or plates. In its classical form, an ABH consists of a local reduction of the thickness of a structure according to a power law profile, associated with a thin viscoelastic coating placed in the thinnest region. A focalization and a wave trap effect occur, leading to a localized energy dissipation, which induces a local temperature increase. The objective of this paper is twofold. First, the goal is to develop an adequate experimental methodology capable of accurately mapping the small temperature variations induced by the local dissipation mechanism. Second, from the thermal standpoint, the goal is to provide experimental evidence of a local temperature increase associated with a damping effect in the case of an ABH beam. This paper thus describes a new kind of experimental methodology able to provide original data, bringing some new insight into the ABH physical understanding and the analysis of structural damping.
A compact electron cyclotron resonance negative hydrogen ion source for evaluation of plasma electrode materials
Authors: Eguchi Takayuki , Sasao Mamiko , Shimabukuro Yuji , Ikemoto Fumiya , Kisaki Masashi , Nakano Haruhisa , Tsumori Katsuyoshi , Wada Motoi
Published: January 2020

A compact ion source that produces hydrogen plasma with an electron cyclotron resonance (ECR) configuration combined with a 2-stage extraction system with a single aperture of 6 mm diameter has been designed and built to study the performance of different materials as the plasma electrode (PE) of a negative hydrogen ion source. The source has the capability to electrically bias the PE with respect to the ECR plasma. The first experiment with low ECR power input (less than 40 W) was carried out. The PE of the C12A7 electride showed the largest H− current among aluminum, molybdenum, and the C12A7 electride.
Theoretical study of the influence of hydrides on the performance of Mg and Y photocathodes
Authors: Chang V. , Camino B. , Noakes T. C. Q. , Lorusso A. , Perrone A. , Harrison N. M.
Published: January 2020

Our understanding of material properties in the broadest sense is based on our ability to observe and disentangle underlying mechanisms. This has been aided enormously by the discovery and exploitation of synchrotron radiation. The next generation of light sources will be based on free electron lasers with potentially much greater light intensity and time resolution. This requires the development of new photocathode materials with high quantum efficiency (QE) and low emittance that are chemically and mechanically robust. One prospect is the use of yttrium (Y) and/or magnesium (Mg) thin films, but here, a fundamental understanding of the photoemission process from realistic materials is lacking. Observations of photoemissive performance would appear to contradict simple models. It is well known that materials with a lower work function are expected to facilitate photoemission, but the measured QE of Mg is higher than that of Y despite its nominal work function (3.7 eV) being significantly higher than that of Y (3.1 eV). In this work, these apparently anomalous observations are explained and rationalized by combining a simple three-step model of photoemission with large scale density functional theory calculations to predict the QE for realistic models of both materials in a special chemical environment. This approach allows us to identify the material parameters that govern the efficiency of the photoemission process. A detailed comparison with the experimental data suggests that, in this case, hydride formation on the Y surface, invisible to most experimental probes, nevertheless has a surprisingly large influence and reduces the photoemission significantly.
Delithiated Fe1-xMgxPO4 cathode materials: Structural, magnetic, and Mössbauer studies
Authors: Choi Hyunkyung , Kim Jeonghun , Seo Jae Yeon , Kim Chul Sung
Published: January 2020

Fe1-xMgxPO4 (x = 0.01, 0.05, and 0.1) cathode materials are synthesized by a two-step method, which combines the solid-state reaction method and the chemical lithium deintercalation method. A study was conducted to investigate the structural and the magnetic properties of Fe1-xMgxPO4. The crystalline structure of the samples was analyzed by X-ray diffractometer (XRD) using the Rietveld refinement. The magnetic properties of the samples were determined from vibrating sample magnetometer (VSM) and Mösssbauer spectroscopy, including their magnetic interactions, Fe ion states, and structural ordering. The Néel temperature (TN) of Fe1-xMgxPO4 decreases with the increase of the Mg content due to the weakening of the antiferromagnetic exchange. Furthermore, for Fe1-xMgxPO4, the effective moment value decreases as expected with increasing Mg content. Mössbauer spectroscopy measurements at different temperatures were made. The spectrum at 295 K was fitted with a doublet, which has an isomer shift of δ = 0.32 – 0.43 mm/s (Fe3+). The large value of the electric quadrupole splitting (∆EQ = 0.95 – 1.87 mm/s) is explained by the asymmetric local environment of the Fe ions. Below the TN, the spectra of Fe1-xMgxPO4 in the eight resonance absorption lines (including two relatively small intensities) were analyzed. We can obtain a spin value for Fe ions (S = 5/2) of Fe0.9Mg0.1PO4 from the Brillouin functional analysis.
Enhanced magnetic and magnetodielectric properties of Al-doped gallium ferrite nanoparticles
Authors: Han Tai-Chun , Tu Zhi-Yuan , Huang Yu-Tao
Published: January 2020

In this work, a series of Ga1-xAlxFeO3 (x = 0, 0.1, 0.2, 0.5) nanoparticles was prepared by a modified Pechini method. The influence of Al doping at the Ga site on the structural, magnetic, and magnetodielectric (MD) properties of GaFeO3 nanoparticles was studied. The X-ray diffraction pattern analysis using the Rietveld refinement method indicated that all samples have an orthorhombic structure with Pc21n space group and the value of lattice parameters decrease systematically with increasing Al concentration. Interestingly, the magnetic characterization indicated that with increasing Al-content up to 0.5, the ferrimagnetic transition temperature (TC) increases from 310 to 350 K. It is also found that magnetic hysteresis curves measured below TC exhibit two-phase-like magnetic behavior consisting of hard and soft magnetic phases. Moreover, the simultaneous improvement of magnetic behavior and MD effect of Al-doped GaFeO3 samples are prominent candidates for the applications of room temperature multiferroic devices.
Toroidal multilayer mirrors for laboratory soft X-ray grazing emission X-ray fluorescence
Authors: Baumann Jonas , Jonas Adrian , Reusch Ruth , Szwedowski-Rammert Veronika , Spanier Malte , Grötzsch Daniel , Bethke Kevin , Pollakowski-Herrmann Beatrix , Krämer Markus , Holz Thomas , Dietsch Reiner , Mantouvalou Ioanna , Kanngießer Birgit
Published: January 2020

Efficient soft X-ray spectroscopy in the laboratory is still a challenging task. Here, we report on new toroidal multilayer optics designed and applied with the laser-produced plasma (LPP) source of the Berlin Laboratory for innovative X-ray technologies. The optics are described and characterized, and the application of the updated source to scanning-free grazing emission X-ray fluorescence is demonstrated on thermoelectric gold-doped copper oxide nanofilms. The comparison with synchrotron measurements allows estimating a flux on the sample of approximately 7.5 × 109 photons/s in the 1 keV range on a 100 µm × 100 µm spot, emphasizing the suitability of the updated LPP source for the application in photon hungry experiments.
Effect of interstitial carbon on the evolution of early-stage irradiation damage in equi-atomic FeMnNiCoCr high-entropy alloys
Authors: Lu Eryang , Makkonen Ilja , Mizohata Kenichiro , Li Zhiming , Räisänen Jyrki , Tuomisto Filip
Published: January 2020

Owing to their excellent radiation tolerance, some of the high-entropy alloys (HEAs) are considered as potential candidates for structural materials in extreme conditions. In order to shed light on the early-stage irradiation damage in HEAs, we performed positron annihilation spectroscopy on hydrogen implanted equiatomic FeMnNiCoCr and interstitial carbon-containing FeMnNiCoCr HEAs. We reveal primary damage as monovacancies in low dose irradiated HEAs. The enhancement of Frenkel pair recombination by C addition is observed in C-containing HEAs. In addition, the C interstitials suppress the vacancy cluster formation in high dose irradiated HEAs.
Near-unity photoluminescence quantum yield in inorganic perovskite nanocrystals by metal-ion doping
Authors: Ahmed Ghada H. , Yin Jun , Bakr Osman M. , Mohammed Omar F.
Published: January 2020

The luminescence and charge transport properties of inorganic CsPbX3 perovskite nanocrystals (NCs) make them attractive candidates for various optoelectronic applications, such as lasing, X-ray imaging, light communication, and light-emitting diodes (LEDs). However, to realize cutting-edge device performance, high-quality NCs with high photoluminescence quantum yields (PLQYs) are essential. Therefore, substantial efforts and progress have been made to attain superior design/engineering and optimization of the inorganic NCs with a focus on surface quality, reduced nonradiative charge carrier recombination centers, and improved colloidal stabilities. Metal-ion doping has been proven to have a robust influence on the electronic band structure, PL behavior, and charge carrier recombination dynamics. Thus, in this perspective, we summarize the recent progress of the significant impact of metal cation doping on the optical properties, including the PL enhancement of CsPbCl3, CsPbBr3, and CsPbI3 perovskite NCs. Moreover, we shed light on the mechanism behind such improved properties. We conclude by recommending possible aspects and strategies to be further explored and considered for better utilization of these doped NCs in thin-film optoelectronic and energy conversion devices.
Influences of thermal effects on cavitation dynamics in liquid nitrogen through venturi tube
Authors: Zhu Jiakai , Wang Shunhao , Zhang Xiaobin
Published: January 2020

Investigation on cavitation features in cryogenic liquids is of great importance to rocket engine design due to their complicated physics. This paper experimentally investigates the characteristics of unsteady liquid nitrogen (LN2) cavitating flow through a transparent venturi tube with image processing techniques. The numerical simulations based on the computational fluid dynamic approach are also performed to help explain the mechanisms. A pressure ratio (Pr) associated with the inlet and the outlet subcooling is found to have a linear relationship with the cavitation number. The nondimensional thermal effect parameter derived from the single bubble dynamics is used to quantify thermal effect intensity. The cavity length derived from standard derivation results has an inversely linear relation with Pr, and there exists an inflection point of the pressure ratio (Prc) below which the cavity length growth rate is relatively larger. The effects of the bulk temperature on the magnitude of Prc are numerically investigated, which reveals that Prc increases as the liquid temperature increases. The oscillating frequencies of the sheet and cloud cavitating flow are also analyzed according to two Strouhal numbers based on cavity length (Stc) and venturi throat diameter (Std), respectively. For cloud cavitation, Stc lies in between 0.30 and 0.40 for all Pr values, while for sheet cavitation, it decreases to 0.04–0.08. Besides, in the cloud cavitation region, Std increases linearly with Pr but has a weak relation with ∑⋅C/uth3. It is also found that with increased values of ∑⋅C/uth3, the transition point of Pr from sheet cavitation to cloud cavitation is delayed.
Characterizations of welding mode transformation process during 1-μm and 10-μm laser welding
Authors: Guo S. H. , Zou J. L. , Xiao R. S.
Published: January 2020

To reveal the enhancing energy coupling effect of plasma, a comparison of the welding mode transformation process during 1-µm and 10-µm laser welding of aluminum alloys is carried out through experimental observation and theoretical analysis. The heat conduction welding stage hardly exists in 10-µm laser welding and obviously exists in 1-µm laser welding. Alloy composition and surface roughness of the welded plate hardly influence the deep penetration welding threshold (DPWT) of the 10-µm laser, whereas they have a significant impact on that of the 1-µm laser. In addition, 1-µm laser welding and 10-µm laser welding have similar DPWTs. These phenomena are attributed to the formation of plasma near the workpiece surface during 10-µm laser welding owing to metal vapor breakdown by 10-µm laser irradiation. The plasma remarkably enhances the energy coupling between the 10-µm laser and workpiece by thermal conduction, and the DPWT of the 10-µm laser is thus reduced to approximately equal to that of the 1-µm laser.
Synthesis of electrospun nanofibrous structures with controlled optical and electrical properties
Authors: Kumar Pradeep , Kiani Amirkianoosh
Published: January 2020

In this study, the optical and electrical influences of 2D graphene flakes in electrospun polycaprolactone (PCL) fibers were observed. Graphene nanoplatelets were added in different concentrations into the PCL solution, and then, using the electrospinning technique, fibers were built from that solution. Three samples were prepared with different graphene concentrations of 0% w/w, 0.5% w/w, and 2.0% w/w. From all three samples, fibers were prepared and tests were conducted for the identification of the properties of fibers. An optical spectroscopy test was performed to identify the optical behavior of the fibers. Scanning electron microscopy tests were conducted for the morphological characterization of the fibers. For the comparison of the electrical conductivity of the three samples, electrical tests were also conducted. In addition, Raman spectroscopy was conducted to characterize the graphene and PCL. This study shows that using graphene can change the properties of fibers, for example, as the graphene content increases, the fiber diameter also increases. Also, by varying the 2D graphene concentration, both electrical and optical properties can be tuned; this can be utilized in the synthesis of nanosensing surfaces and structures.
Defining Lagrangian coherent vortices from their trajectories
Authors: El Aouni A. , Daoudi K. , Yahia H. , Maji S. K. , Minaoui K.
Published: January 2020

We study the transport properties of mesoscale eddies (i.e., vortices of 100–200 km in diameter) over a finite time duration. While these oceanic structures are well-known to stir and mix surrounding water, they can also carry and transport water properties in a coherent manner. In this paper, we are interested in dynamic transport properties of these coherent structures, despite their chaotic environment. Here, we reveal that such vortices can be identified based a simple decomposition of their Lagrangian trajectories. We identify and extract coherent vortices as material lines along which particles’ trajectories share similar polar rotations. The proposed method identifies coherent vortices and their centers in an automatic manner. We illustrate our new method by identifying and extracting Lagrangian coherent vortices in different two-dimensional flows.
Investigating uneven recovery of repatriated bobcats (Lynx rufus) in a mined landscape: space use, habitat use and condition in coal country
Authors: Prange I. Suzanne , Rose Christa
Published: January 2020

Abstract
ContextBobcats (Lynx rufus) were extirpated from Ohio, USA, during the mid-1800s. Genetic evidence indicates that they recolonised from neighbouring states. Initial re-establishment occurred almost simultaneously in two spatially distinct areas of a coal-mined landscape in the 1980s. Relative population growth was apparently higher in the eastern than in the southern area.
AimsUnderstanding the reasons for the disparity in population dynamics and sustainability is essential for proper bobcat management. It also addresses substantial knowledge gaps in vertebrate carnivore ecology on mined land. We hypothesised that the characteristics of mined land in the eastern Ohio area provided bobcats with greater resources, enabling a more rapid recovery.
MethodsWe trapped bobcats and took body measurements and weights to determine condition indices. We attached GPS radio-collars and used locations to determine annual home-range and core-area sizes, home-range and core-area overlap, and habitat selection using remotely sensed land cover data and mine permit records. We compared factors between the two bobcat population areas.
Key resultsBody condition indices were higher, and home ranges and core areas of males and females were smaller, for eastern Ohio bobcats. Home-range overlap did not differ for any dyad type. Selection of mined land by habitat type differed at the home-range level, with eastern bobcats selecting more mined habitats and southern bobcats showing an opposite tendency.
ConclusionsAn interaction may exist between landscape features of former surface mines and bobcat recovery. Results suggest more favourable habitat conditions in the eastern area, which featured more mined land and more older, less regulated mines, than in the southern area. These conditions may support a higher bobcat reproductive success.
ImplicationsThe first bobcat harvest season in Ohio is under development by authorities. We recommend the regulation of eastern and southern Ohio as separate bobcat management units; the southern population should remain protected, and the eastern population should be managed conservatively as a source population to further colonise southern Ohio. Our data suggest that surface-mined land can be conducive to the restoration and conservation of species.
Expansion, in vivo–ex vivo cycling, and genetic manipulation of primary human hepatocytes
Authors: Michailidis Eleftherios , Vercauteren Koen , Mancio-Silva Liliana , Andrus Linda , Jahan Cyprien , Ricardo-Lax Inna , Zou Chenhui , Kabbani Mohammad , Park Paul , Quirk Corrine , Pyrgaki Christina , Razooky Brandon , Verhoye Lieven , Zoluthkin Irene , Lu Wei-Yu , Forbes Stuart J. , Chiriboga Luis , Theise Neil D. , Herzog Roland W. , Suemizu Hiroshi , Schneider William M. , Shlomai Amir , Meuleman Philip , Bhatia Sangeeta N. , Rice Charles M. , de Jong Ype P.
Published: January 2020

Primary human hepatocytes (PHHs) are an essential tool for modeling drug metabolism and liver disease. However, variable plating efficiencies, short lifespan in culture, and resistance to genetic manipulation have limited their use. Here, we show that the pyrrolizidine alkaloid retrorsine improves PHH repopulation of chimeric mice on average 10-fold and rescues the ability of even poorly plateable donor hepatocytes to provide cells for subsequent ex vivo cultures. These mouse-passaged (mp) PHH cultures overcome the marked donor-to-donor variability of cryopreserved PHH and remain functional for months as demonstrated by metabolic assays and infection with hepatitis B virus and
Plasmodium falciparum
. mpPHH can be efficiently genetically modified in culture, mobilized, and then recultured as spheroids or retransplanted to create highly humanized mice that carry a genetically altered hepatocyte graft. Together, these advances provide flexible tools for the study of human liver disease and evaluation of hepatocyte-targeted gene therapy approaches.
Neutralisation and contrast preservation
Authors: Bárkányi Zsuzsanna , Kiss Zoltán G.
Published: January 2020

This paper studies the contextual variation in the voicing properties of three-consonant clusters (CC#C) in Hungarian. We investigate the velar+alveolar stop clusters /kt/ and /ɡd/, and the alveolar fricative+stop clusters /st/ and /zd/ in potentially voicing-neutralising and assimilating contexts. We show that in these contexts, regressive voicing assimilation in Hungarian is categorical, but partially contrast preserving, and that stops and fricatives are not affected in the same way. Fricatives resist voicing before a voiced obstruent and are devoiced utterance-finally. This is a phonetically unfavourable position, therefore other duration-related cues step up to prevent complete laryngeal neutralisation.
Zfp521 SUMOylation facilities erythroid hematopoietic reconstitution under stress
Authors: Zhang Yali , Xu Shuangnian , Chen Zhe , Xie Mingling , Ma Yanni , Wu Guixian , Huang Xiangtao , Luo Chengxin , Huang Zhen , Sun Yanni , Huang Yongxiu , Li Xi , Hou Yu , Chen Jieping
Published: January 2020

Zinc finger protein 521 (Zfp521) is a key transcriptional factor in regulation of hematopoiesis. SUMOylation, a protein post-translational modification process, plays important roles in various biological process including hematopoiesis. However, whether Zfp521 can be SUMOylated and how it affects hematopoiesis is unknown. In this study, we confirmed that Zfp521 can be modified by SUMO1 and lysine 1146 was the primary SUMOylation site. Under homeostatic condition, Zfp521 SUMOylation-deficient mice had normal mature blood cells and primitive cells. However, in bone marrow (BM) transplantation assay, recipient mice transplanted with BM cells from Zfp521 SUMOylation-deficient mice had a significantly decreased R2 population of erythroid lineage in BM and spleen compared with those transplanted with BM cells from wild-type mice. Our results found a novel function of Zfp521 SUMOylation in erythroid reconstitution under stress, which might be a new therapeutic target in future.
Comparative analysis of enteroendocrine cells and their hormones between mouse intestinal organoids and native tissues
Authors: Ohki Junko , Sakashita Akihiko , Aihara Eitaro , Inaba Akihiko , Uchiyama Hironobu , Matsumoto Masahito , Ninomiya Yuzo , Yamane Takumi , Oishi Yuichi , Iwatsuki Ken
Published: January 2020

Endocrine cells in the gastrointestinal tract secrete multiple hormones to maintain homeostasis in the body. In the present study, we generated intestinal organoids from the duodenum, jejunum, and ileum of Neurogenin 3 (Ngn3)-EGFP mice and examined how enteroendocrine cells (EECs) within organoid cultures resemble native epithelial cells in the gut. Transcriptome analysis of EGFP-positive cells from Ngn3-EGFP organoids showed gene expression pattern comparable to EECs in vivo. We also compared mRNAs of five major hormones, namely, ghrelin (Ghrl), cholecystokinin (Cck), Gip, secretin (Sct), and glucagon (Gcg) in organoids and small intestine along the longitudinal axis and found that expression patterns of these hormones in organoids were similar to those in native tissues. These findings suggest that an intestinal organoid culture system can be utilized as a suitable model to study enteroendocrine cell functions in vitro.
Rapid hamstrings to quadriceps ratio at long muscle lengths in professional football players with previous hamstring strain injury
Authors: Correia Paulo , Santos Paulo , Mil‐Homens Pedro , Gomes Miguel , Dias Amândio , Valamatos Maria João
Published: January 2020

Hamstring strain injuries (HSI) are the most common injury in male professional football and are potentially a primary risk factor to re‐injury. Although the isokinetic strength ratios have often been used to identify strength imbalances that can augment the risk of injury in football players, the rate of torque development hamstring to quadriceps ratio (RTD H/Q) has rarely been considered in previous reports. Furthermore, little consideration has been given to selective hamstring lengths (30° of knee flexion) and its influence on torque production. The aim of this study was to investigate the RTD H/Q at long hamstring lengths, conventional (concentric/concentric) and functional (eccentric/concentric) H/Q ratios in football players with and without previous HSI. Twenty‐four professional male football players (12 and 12 without previous HSI) performed maximal voluntary isometric contractions at long hamstring lengths (knee and hip flexed at 30° and 85°, respectively) and isokinetic concentric and eccentric contractions at 180°.s−1 and 60°.s−1. Conventional and functional H/Q ratios based on peak torque throughout the entire isokinetic range of motion and at long hamstring lengths were calculated. The RTD H/Q was extracted at long hamstring lengths in incrementing time periods of 50 milliseconds (ms) from the onset of contraction (50–250 ms). No significant differences were found between groups in any H/Q ratios studied. However, small effects (d = 0.4) were found in previously injured hamstrings to lower RTD H/Q at 50 ms and flexor eccentric torque. Previous HSI group showed small to moderate (0.4 > d < 0.6) higher RTD H/Q in late time intervals (>100 ms).