bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical Technique of Supine Percutaneous Nephrolithotomy in Children
Authors: Prada Stefania , Fernandez Nicolas , Chavarriaga Julián , Perez Jaime , López-Ramos Hugo
Published: December 2021

Percutaneous nephrolithotomy (PCNL) in children has become more widely used due to its high efficacy and safety and to the development of miniaturized instruments. A supine approach is promising due to advantages such as better ventilation, reproducibility, and ergonomics. The purpose of the present study is to describe our surgical technique with special considerations in the pediatric population. We used an oblique supine position supported by one silicone gel positioning pad under the hip and another under the ipsilateral flank. The anatomical landmarks used to guide the puncture were the 11th and 12th ribs, the posterior axillary line, and the iliac crest. Initially, a ureteral catheter was introduced endoscopically. A retrograde pyelography was performed to guide the puncture, which was performed using a biplanar technique. A hydrophilic guide wire was then advanced through the needle. Dilation was performed with Alken telescopic dilators until 14 Ch. Fragmentation was performed either with a 13 Ch semirigid cystoscope or a flexible ureteroscope using a holmium: yttrium aluminum garnet (Ho:Yag) laser. We left a double J catheter. Supine PCNL in the pediatric population has comparable efficacy in terms of stone free rate to that of the prone approach as well as less complications. Certain considerations in children are careful padding and placement of the patient close to the edge of the table. Puncture should be guided by ultrasound to reduce radiation exposure. Miniaturized equipment is not widely available, so adaptation of adult equipment for the pediatric population is sometimes necessary.
Musculoskeletal Applications of Magnetic Resonance-Guided Focused Ultrasound
Authors: Bucknor Matthew D. , Baal Joe D. , McGill Kevin C. , Infosino Andrew , Link Thomas M.
Published: December 2021

Magnetic resonance-guided focused ultrasound (MRgFUS) is a novel noninvasive therapy that uses focused sound energy to thermally ablate focal pathology within the body. In the United States, MRgFUS is approved by the Food and Drug Administration for the treatment of uterine fibroids, palliation of painful bone metastases, and thalamotomy for the treatment of essential tremor. However, it has also demonstrated utility for the treatment of a wide range of additional musculoskeletal (MSK) conditions that currently are treated as off-label indications. Advantages of the technology include the lack of ionizing radiation, the completely noninvasive technique, and the precise targeting that offer unprecedented control of the delivery of the thermal dose, as well as real-time monitoring capability with MR thermometry. In this review, we describe the most common MSK applications of MRgFUS: palliation of bone metastases, treatment of osteoid osteomas, desmoid tumors, facet arthropathy, and other developing indications.
Presión y área de contacto en reparación de manguito rotador: una revisión sistemática
Authors: Contreras Julio , Liendo Rodrigo , Maccioni Cristóbal , Beltrán Manuel
Published: December 2021

Objetivo Proporcionar una sinopsis exhaustiva y un análisis de los estudios biomecánicos sobre la magnitud y distribución de la presión en la interfase tendón-huella de las roturas del manguito rotador, informadas en la literatura en los últimos cinco años.

Métodos La investigación se realizó de acuerdo con los métodos descritos en el Manual Cochrane. Los resultados se informan de acuerdo con el consenso de Ítems Preferidos de Reporte en Revisiones Sistemáticas y Metaanálisis (Preferred Reporting Items for Systematic Reviews and Meta-Analyses, PRISMA, en inglés). La búsqueda se realizó el 1er de junio de 2020. Se identificaron e incluyeron estudios ex vivo de ciencia básica y estudios biomecánicos publicados, que evaluaran la magnitud y distribución de la presión en la interfase tendón-huella de las roturas del manguito rotador reparadas entre enero de 2015 y junio de 2020. Se realizaron búsquedas sistemáticas en las bases de datos MEDLINE, Embase, Scopus y Google Scholar utilizando los términos y operadores booleanos: (Rotator Cuff OR Supraspinatus OR Infraspinatus OR Subscapularis OR Teres Minor) AND Pressure AND Footprint. En la base de datos Embase, respetando su sintaxis, se utilizó: Rotator Cuff AND Pressure AND Footprint.

Resultados Un total de 15 de los 87 artículos encontrados cumplieron con todos los criterios de elegibilidad y se incluyeron en el análisis.

Conclusión La presión y área de contacto sería optimizada biomecánicamente con una reparación transósea de doble fila equivalente, sin nudos en la hilera medial, y con el uso de cintas para su ejecución, conceptos de reparación específica para roturas delaminadas, y limitación de la abducción en el postoperatorio inmediato.
Costoefectividad del régimen combinado de mirabegron/solifenacina en el tratamiento del síndrome de vejiga hiperactiva en Colombia
Authors: Lasalvia Pieralessandro , Gil-Rojas Yaneth , Hernández Fabián , Castañeda-Cardona Camilo
Published: December 2021

Objetivo Evaluar la costoefectividad incremental del régimen combinado de mirabegron/solifenacina en comparación con el uso temprano de toxina botulínica, desde la perspectiva del sistema de salud colombiano, para el tratamiento de adultos con vejiga hiperactiva.

Métodos Se empleó un modelo de Markov en que se comparan dos secuencias de tratamiento, una con y otra sin mirabegron/solifenacina, para evaluar la costoefectividad en un horizonte temporal de cinco años. Debido a la perspectiva de análisis, sólo se tuvieron en cuenta los costos médicos directos. La eficacia del tratamiento evaluado y su comparador fue medida en términos de la reducción de episodios diarios de incontinencia y de la frecuencia de micciones. Los costos fueron expresados en pesos colombianos de 2019, y se aplicó una tasa de descuento de 5% tanto para desenlaces como para costos.

Resultados Para el caso base, el costo del tratamiento en la secuencia que incluye mirabegron/solifenacina fue mayor, pero generó un mayor número de años de vida ajustados por calidad, y así e obtuvo una razón de costoefectividad incremental de $13.637,184 si se considera el desenlace de reducción de episodios diarios de incontinencia de 50%, y de $29.313,848 si se considera el del 100%.

Conclusiones De acuerdo con los resultados de esta evaluación, para un horizonte de análisis de cinco años, la secuencia de tratamiento con mirabegron/solifenacina es una alternativa costoefectiva, si se considera un umbral de disposición a pagar de tres veces el producto interno bruto (PIB) per cápita.
Efectos del tadalafilo en el deseo sexual y la excitación/lubricación en mujeres postmenopáusicas
Authors: De La Hoz Franklin José Espitia
Published: December 2021

Objetivo Determinar los efectos y la seguridad del tadalafilo en el deseo sexual y la excitación/lubricación en mujeres postmenopáusicas.

Métodos Estudio cuasi experimental (con comparación antes de la intervención y después), con seguimiento de la cohorte de pacientes: 228 mujeres mayores de 40 años en postmenopausia, que consultaron por bajo deseo sexual y alteración de la excitación /lubricación, en una clínica sexológica en Armenia (Colombia), entre 2018 y 2019. Las mujeres recibieron 2,5 mg diarios de tadalafilo durante 12 semanas. Se determinaron las puntuaciones del instrumento, el Índice de Función Sexual Femenina (IFSF), cada cuatro semanas.

Resultados El promedio de edad fue de 54,36 ± 4,92 años. Antes del tratamiento, la media en la puntuación del IFSF fue de 22,41 puntos (intervalo de confianza del 95% [IC95%]: 7,11–29,76); a las 4 semanas, 24,73 puntos (IC95%: 23,51–30,28); a las 8 semanas, 25,97 puntos (IC95%: 24,26–31,53); y, al final, 26,99 puntos (IC95%: 25,97–32,46), con diferencias estadísticamente significativas entre las 4 medidas pareadas (p < 0,001). La excitación fue el dominio con mayor puntuación tras el tratamiento (4,83 puntos; IC 95%: 4,36–4,91), seguida por la lubricación (4,77 puntos; IC95%: 4,28–4,87). El deseo sexual mostró un significativo incremento al final del estudio (4,29 puntos; IC95%: 4,07–4,39). Se presentaron efectos adversos leves. Se observó una satisfacción con el consumo de tadalafilo del 84,21%.

Conclusiones El tratamiento diario con 2,5 mg de tadalafilo genera mejoría en la función sexual de mujeres en la postmenopausia, y el incremento en la puntuación del IFSF demuestra su efecto positivo.
Benchmark Calculations of the Energy Spectra and Oscillator Strengths of the Beryllium Atom
Authors: Nasiri Saeed , Adamowicz Ludwik , Bubin Sergiy
Published: December 2021

In this work, we present a series of benchmark variational calculations for the ground and 19 lowest bound excited singlet S and P states of the beryllium atom. The nonrelativistic wave functions of the states that represent the motion of the nucleus and the four electrons around the center of mass of the atom are expanded in terms of up to 17 000 all-particle explicitly correlated Gaussians. The Gaussians are optimized independently for each state. The leading relativistic corrections to the energy levels are computed in the framework of the perturbation theory and they explicitly include the nuclear recoil effects. We also calculate the leading quantum electrodynamics (QED) corrections for each considered state. Using the obtained energy levels and the corresponding wave functions, we compute the transition frequencies, transition dipole moments, and oscillator strengths. A comparison with the available experimental data shows very good agreement. The results of this most comprehensive set of calculations of spectroscopic accuracy for Be to date may open up new applications pertinent to the precision tests of QED, determination of the nuclear charge radius, and modeling matter-radiation equilibria of the beryllium gas that has relevance to the physics of interstellar media.
A multiple time step algorithm for trajectory surface hopping simulations
Authors: Baudin Pablo , Mouvet François , Rothlisberger Ursula
Published: December 2021

A multiple time step (MTS) algorithm for trajectory surface hopping molecular dynamics has been developed, implemented, and tested. The MTS scheme is an extension of the ab initio implementation for Born–Oppenheimer molecular dynamics presented in the work of Liberatore et al. [J. Chem. Theory Comput. 14, 2834 (2018)]. In particular, the MTS algorithm has been modified to enable the simulation of non-adiabatic processes with the trajectory surface hopping (TSH) method and Tully’s fewest switches algorithm. The specificities of the implementation lie in the combination of Landau–Zener and Tully’s transition probabilities during the inner MTS time steps. The new MTS-TSH method is applied successfully to the photorelaxation of protonated formaldimine, showing that the important characteristics of the process are recovered by the MTS algorithm. A computational speed-up between 1.5 and 3 has been obtained compared to standard TSH simulations, which is close to the ideal values that could be obtained with the computational settings considered.
Quantum dot photoluminescence as a versatile probe to visualize the interaction between plasma and nanoparticles on a surface
Authors: Marvi Z. , Donders T. J. M. , Hasani M. , Klaassen G. , Beckers J.
Published: December 2021

We experimentally demonstrate that the interaction between plasma and nanometer-sized semiconductor quantum dots (QDs) is directly connected to a change in their photoluminescence (PL) spectrum. This is done by taking in situ, high resolution, and temporally resolved spectra of the light emitted by laser-excited QDs on an electrically floating sample exposed to a low pressure argon plasma. Our results show a fast redshift of the PL emission peak indicating the quantum-confined Stark effect due to plasma-generated excess charges on the substrate and near the QD surface, while other plasma-induced (thermal and ion) effects on longer timescales could clearly be distinguished from these charging effects. The presented results and method open up pathways to direct visualization and understanding of fundamental plasma–particle interactions on nanometer length scales.
Atomistic simulations of deformation mechanism of fcc/bcc dual-phase high-entropy alloy multilayers
Authors: Ding B. , Song H. Y. , An M. R. , Xiao M. X. , Li Y. L.
Published: December 2021

Dual-phase nanoscale lamellar microstructures containing alternating regions of soft phase and hard phase are known to produce alloys with an exceptional combination of strength and plasticity. Here, the effect of layer thickness on the mechanical properties and deformation mechanism of the fcc/bcc dual-phase CoNiFeAlxCu1−x high-entropy alloys multilayers are investigated by the molecular dynamics simulation method. The results show that the deformation behavior of the multilayers is strongly related to the layer thickness. At the yield point, the deformation behavior of the small thickness multilayer is caused by the dislocation slip in the fcc phase, while the plastic deformation of the large thickness multilayer is initiated by the bcc → hcp phase transformation in the bcc phase. During the subsequent plastic deformation, the phase transformation of bcc → fcc also occurred in the bcc phase of the multilayer, which depended on the relative size of the bcc phase in the multilayer. Especially for the multilayer with the layer thickness of 2 nm, the bcc → fcc phase transformation promotes the formation of twins, and the fcc/bcc phase interface transforms into a perfect twin boundary. The twin formation mechanism and phase transformation mechanism are also discussed in detail.
Role of residual thermal stress on the electrochemical performance of a solid-state half-cell
Authors: Shang Shuaipeng , Wang Fenghui
Published: December 2021

Synthesizing a solid electrolyte layer with a positive electrode layer requires a high-temperature sintering process to improve the interface contact between the two layers. This may generate substantial residual thermal stress between the components during cooling. In this study, we develop a theoretical model to investigate the influence of residual thermal stress on the electrochemical performance of a solid-state half-cell (solid electrolyte–positive electrode). The model accounts for the stress–diffusion interaction and electrochemical reaction and is based on the classical plate theory. The numerical results indicate that, although the residual thermal stress could effectively improve the half-cell capacity, the structural mechanical reliability is reduced. The improvement in the battery capacity is found to be highly dependent on the ratio of the thermal expansion coefficients of the solid electrolyte and the positive electrode. The thermal expansion coefficients determine whether the operating temperature needs to be raised or reduced. Additionally, under the influence of residual thermal stress, reasonable control of the thickness of a solid electrolyte can significantly improve battery capacity. Finally, by examining the stress drop at the interface, we found that introducing residual thermal stress is detrimental to the structural mechanical reliability of the half-cell, meaning that the conflicting demands for improved capacity and mechanical reliability seem irreconcilable.
Particle dynamics in viscoelastic media: Effects of non-thermal white noise on barrier crossing rates
Authors: Cherayil Binny J.
Published: December 2021

The growing interest in the dynamics of self-driven particle motion has brought increased attention to the effects of non-thermal noise on condensed phase diffusion. Thanks to data recently collected by Ferrer et al. on activated dynamics in the presence of memory [Phys. Rev. Lett. 126, 108001 (2021)], some of these effects can now be characterized quantitatively. In the present paper, the data collected by Ferrer et al. are used to calculate the extent to which non-thermal white noise alters the time taken by single micron-sized silica particles in a viscoelastic medium to cross the barrier separating the two wells of an optically created bistable potential. The calculation—based on a generalized version of Kramers’s flux-over-population approach—indicates that the added noise causes the barrier crossing rate (compared to the noise-free case) to first increase as a function of the noise strength and then to plateau to a constant value. The precise degree of rate enhancement may depend on how the data from the experiments conducted by Ferrer et al. are used in the flux-over-population approach. As claimed by Ferrer et al., this approach predicts barrier crossing times for the original silica-fluid system that agree almost perfectly with their experimental counterparts. However, this near-perfect agreement between theory and experiment is only achieved if the theoretical crossing times are obtained from the most probable values of a crossing time distribution constructed from the distributions of various parameters in Kramers’s rate expression. If the mean values of these parameters are used in the expression instead, as would be commonly done, the theoretical crossing times are found to be as much as 1.5 times higher than the experimental values. However, these times turn out to be consistent with an alternative model of viscoelastic barrier crossing based on a mean first passage time formalism, which also uses mean parameter values in its rate expression. The rate enhancements predicted for barrier crossing under non-thermal noise are based on these mean parameter values and are open to experimental verification.
Theoretical and experimental study of bubble dynamics in underwater explosions
Authors: Wang Shushan , Gui Qiuyang , Zhang Jingxiao , Gao Yuan , Xu Jie , Jia Xiyu
Published: December 2021

The development of analytical theory and experimental methods for understanding the correlation between the explosive properties and bubble dynamic characteristics in underwater explosions has important engineering application value for underwater weapons and ships. Based on the assumption of an instantaneous explosive detonation, we introduced the Jones–Wilkins–Lee equation of state to describe the high-pressure state in an explosion bubble and established the initial conditions for the bubble dynamics calculations. Considering the high-Mach-number flow and high pressure at the initial boundary of the explosion bubble, the Lezzi–Prosperetti equation with second-order Mach accuracy was used. Thus, an analytical model and a calculation method of the explosion bubble dynamics for an explosive detonation were established. This direct link between the detonation parameters and the bubble features is significant for the subtle design, selection, and optimization of explosives' properties. A micro-equivalent explosive bubble pulsation experiment was carried out in a water tank using a customized experimental system, which can offer nearly boundary-free condition to mitigate the reflective wave effects on bubbles. Three types of explosives were used in the experiment: the Research Department explosive (RDX), the Pentaerythritol tetranitrate (PETN), and the Hexanitrohexaazaisowurtzitane (CL20). Finally, the experimental results and the practicability of the experimental system were analyzed. The influence of the explosive type on the dynamic characteristics of the explosion bubbles and the differences between the theoretical and experimental results were compared. The results showed that the proposed explosion bubble dynamics model and calculation method have high accuracy and practicability. The proposed model can be used for explosives with known detonation parameters and equation of state parameters. The detonation parameters, velocity, and pressure are linked to the bubble features pulsation period and the maximum radius directly. The designed experimental system, which is capable of simulating an infinite water for the explosion of micro-equivalent explosives, was stable and easy to use. The work is significant for the subtle design, selection, and optimization of explosives' properties.
Bistability of cavity magnon polaritons beyond the Holstein–Primakoff transformation
Authors: Bi M. X. , Dai C. J. , Che Jun-Ling , Hu Ming-Liang , Yan X. H.
Published: December 2021

We report a theoretical study of the bistability of cavity magnon polaritons (CMPs) controlled by dual magnetic nonlinearities. Based on the magnon Kerr effect, we introduce the nonlinear magnon effect in this hybrid system without using the Holstein–Primakoff transformation and find that these two types of nonlinear mechanisms jointly determine the bistability of the system. When the lower-branch polariton is exposed to a microwave driving field, the magnon frequency shift gives rise only to a clockwise hysteresis loop with the appearance of bistability. However, when the upper-branch polariton is exposed to a microwave driving field, the magnon frequency shift produces either a clockwise or counterclockwise hysteresis loop. Interestingly, the bistability vanishes because the Kerr effect cancels the nonlinear magnon effect. Moreover, the simultaneous bistability of both the lower- and upper-branch polaritons occurs when the microwave driving field drives one of the two polaritons. These results for the dual magnetic nonlinearities in CMPs offer more possibilities for information processing and cavity spintronic device design.
The influence of the coefficient of restitution on flow regimes within horizontal particle-laden pipe flows
Authors: Zhang Xinchen , Nathan Graham J. , Tian Zhao F. , Chin Rey C.
Published: December 2021

Numerical simulations of the particle-laden gas–solid flow in horizontal circular pipes have been used to identify the role of particle collision coefficients in flow regimes within it. A four-way coupling Euler–Lagrangian approach was employed, using direct numerical simulations of the gas phase and Lagrangian particle tracking to account for the drag, gravitational and lift forces, together with particle–wall and inter-particle interactions. The influences on the flow of the mass loading ratio (Φm) and of the coefficients of restitution for collisions both between particles and the wall (ep−w) and between particles (ep−p) are assessed by examining the fluid and particle velocities, particle concentration distribution, turbulence kinetic energy, static pressure, inter-phase transferred momentum, and the secondary flow motions of both the fluid and particle phases. Three dominant flow regimes that include three sub-regimes based on their secondary flow patterns are identified, the transition between which depends on the combination of Φm, ep−w, and ep−p. Additionally, the quantitative dependence of these transitions on these three parameters is also reported for a series of Stokes and Froude numbers.
Hybridization of dark resonant states in terahertz metasurfaces
Authors: Kaur Sukhvinder , Karmakar Subhajit , Jana Arun , Varshney Ravendra Kumar , Roy Chowdhury Dibakar
Published: December 2021

Dark resonating states render an important role in curtailing the dominant radiative losses in various photonic structures like metamaterials (MMs), photonic crystals, waveguides, etc. Currently, radiative losses are the major degrading factors toward the strong confinement of electromagnetic radiation for MMs’ applications in sensing, imaging, filters, modulators, nonlinear studies, etc. Generally, the dark states cannot be excited through the direct interaction of electromagnetic radiations with the metastructures. However, indirect excitation at suitable structural asymmetries can trigger the evolution of dark resonating states or trapped modes. In this work, we have experimentally demonstrated mode hybridization of such dark (sub-radiant) resonating states without the direct involvement of interacting bright (super-radiant) states in a metasurface consisting of asymmetric split-ring resonators. Our study further reveals that the lattice mode plays a crucial role in determining the line shapes of the split (hybridized) modes. Such tuning of dark resonance modes can find potential applications in metasurfaces-based sensing, non-linear devices besides other potential applications desiring multi-channel strong field confinement.
Mass production of self-passivated perovskite microlaser particles by solution-phase processing for gas sensors
Authors: Ren Yinjuan , Miao Chunyang , Feng Likuan , Wang Ziming , Liu Shengli , Chen Peiran , Wu Yuting , Wang Yue
Published: December 2021

Developing mass-productive and high-performance microlaser particles (MLPs) by cost-effective approaches is highly promising for MLP-based optoelectronic applications, which remains a daunting challenge. Herein, we develop a novel solution-phase technique to realize the halide perovskite-based MLPs in a scalable manner. By regulating the dynamic process of crystallization in a two-step spin-coating procedure, the large-scale CsPbBr3 microcrystals are acquired. Importantly, the solution-processed CsPbBr3 microcrystals exhibit much stronger emission than the ones prepared by the chemical vapor deposition method, which is attributed to the low carrier trap density by the formation of a self-passivated and bromine-rich surface. These CsPbBr3 microcrystals with inverted pyramid morphology are demonstrated to support the whispering-gallery mode lasing, featuring low pump threshold and high Q-factor. Moreover, the technologically important single-mode lasing is achieved from the sub-5 μm-sized MLPs, thanks to the superior optical property. Eventually, the laser-emission-based gas sensor is demonstrated. These results represent a significant step toward scalable MLPs and related applications.
Electron transport in high power impulse magnetron sputtering at low and high working gas pressure
Authors: Rudolph Martin , Kalanov Dmitry , Diyatmika Wahyu , Anders André
Published: December 2021

The magnetic field of a magnetron serves to increase the residence time of electrons in the ionization region and thereby enables the discharge to be sustained at low working gas pressures. This hinders the electrons to reach the anode which is necessary to close the electrical circuit. At high atom densities in the ionization region, and in the presence of an electric field, collisions of electrons with heavy species consecutively push electrons across the magnetic field lines, which is known as the classical cross-field transport mechanism. At low atom densities in the ionization region, collisions are rare and the classical cross-field transport mechanism is insufficient to carry the discharge current. This gives rise to plasma instabilities, called spokes, that locally provide pathways for electrons to escape from the near-target region and across the magnetic field lines. Here, we show experimentally, for the case of a high power impulse magnetron sputtering discharge with an aluminum target, how spokes gradually disappear with the increase in local gas density. We present an analytical model that shows that under these high gas density conditions, the classical electron transport mechanism is indeed strong enough to solely carry the discharge current. This highlights the importance of the local gas density in the ionization region for the intensity of spokes in a magnetron sputtering discharge and suggests ways for process optimization.
Elastoplastic and polymorphic transformations of iron at ultra-high strain rates in laser-driven shock waves
Authors: Murzov Semen , Ashitkov Sergey , Struleva Evgenia , Komarov Pavel , Zhakhovsky Vasily , Khokhlov Victor , Inogamov Nail
Published: December 2021

Elastoplastic and polymorphic α–ε transformations in iron films induced by ultra-short laser-driven shock waves are studied. Interpretation of time-resolved interferometric measurements is performed using an inverse analysis technique of experimental rear-side velocity profiles. The lasts are obtained by numerical differentiation of free surface displacements detected by probe laser pulses. The inverse analysis techniques are validated in consistent two-temperature hydrodynamics and molecular dynamics simulations of laser energy deposition and diffusion, generation, and propagation of shock waves in a polycrystalline iron sample. The stress–strain diagrams containing information about elastoplastic deformation and phase transformation are reconstructed by the inverse analysis. We found that the polymorphic transformation in iron under picosecond duration of loading requires much higher stress in contrast to that in microsecond-scale plate-impact experiments. Moreover, such transition may be accomplished partially even at very high stresses if an unloading tail after the shock front is too short.
50 Ω transmission lines with extreme wavelength compression based on superconducting nanowires on high-permittivity substrates
Authors: Santavicca Daniel F. , Colangelo Marco , Eagle Carleigh R. , Warusawithana Maitri P. , Berggren Karl K.
Published: December 2021

We demonstrate impedance-matched low-loss transmission lines with a signal wavelength more than 150 times smaller than the free space wavelength using superconducting nanowires on high permittivity substrates. A niobium nitride thin film is patterned in a coplanar waveguide (CPW) transmission line geometry on a bilayer substrate consisting of 100 nm of epitaxial strontium titanate on high-resistivity silicon. The use of strontium titanate on silicon enables wafer-scale fabrication and maximizes process compatibility. It also makes it possible to realize a 50 Ω characteristic impedance across a wide range of CPW widths from the nanoscale to the macroscale. We fabricated and characterized an approximately 50 Ω CPW device with two half-wave stub resonators. Comparing the measured transmission coefficient to numerical simulations, we determine that the strontium titanate film has a dielectric constant of 1.1×103 and a loss tangent of not more than 0.009. To facilitate the design of distributed microwave devices based on this type of material system, we describe an analytical model of the CPW properties that gives good agreement with both measurements and simulations.
Multiscale relaxation dynamics and diffusion of myelin basic protein in solution studied by quasielastic neutron scattering
Authors: Hassani Abir N. , Haris Luman , Appel Markus , Seydel Tilo , Stadler Andreas M. , Kneller Gerald R.
Published: December 2021

We report an analysis of high-resolution quasielastic neutron scattering spectra from Myelin Basic Protein (MBP) in solution, comparing the spectra at three different temperatures (283, 303, and 323 K) for a pure D2O buffer and a mixture of D2O buffer with 30% of deuterated trifluoroethanol (TFE). Accompanying experiments with dynamic light scattering and Circular Dichroism (CD) spectroscopy have been performed to obtain, respectively, the global diffusion constant and the secondary structure content of the molecule for both buffers as a function of temperature. Modeling the decay of the neutron intermediate scattering function by the Mittag-Leffler relaxation function, ϕ(t) = Eα(−(t/τ)α) (0 < α < 1), we find that trifluoroethanol slows down the relaxation dynamics of the protein at 283 K and leads to a broader relaxation rate spectrum. This effect vanishes with increasing temperature, and at 323 K, its relaxation dynamics is identical in both solvents. These results are coherent with the data from dynamic light scattering, which show that the hydrodynamic radius of MBP in TFE-enriched solutions does not depend on temperature and is only slightly smaller compared to the pure D2O buffer, except for 283 K, where it is much reduced. In accordance with these observations, the CD spectra reveal that TFE induces essentially a partial transition from β-strands to α-helices, but only a weak increase in the total secondary structure content, leaving about 50% of the protein unfolded. The results show that MBP is for all temperatures and in both buffers an intrinsically disordered protein and that TFE essentially induces a reduction in its hydrodynamic radius and its relaxation dynamics at low temperatures.
Field-free spin–orbit torque switching induced by interlayer exchange coupling in Pt/Co/Ru/Ni/Pt multilayer
Authors: Dai Zhiming , Liu Wei , Zhao Xiaotian , Liu Long , Song Yuhang , Zhang Zhidong
Published: December 2021

High-efficient operation of spin–orbit torque (SOT) is central for the exciting field of spin-orbitronics. To realize a deterministic field-free SOT switching, here, we investigate the enhancement mechanism of SOT with the interlayer exchange coupling in a Pt/Co/Ru/Ni/Pt multilayer. We find that the decrease of the domain wall energy in an interlayer exchange coupling system is the pivotal reason for achieving current-induced field-free domain wall switching. Comparing with the direct ferromagnetic couplings, the switching ratio and efficiency present a significant improvement in the interlayer exchange coupling system. Combining micromagnetic simulations and magneto-optical Kerr effect measurements, the domain wall motions are investigated and the switching mechanism is confirmed to be the domain wall depinning regime. Furthermore, the SOT switching direction is proven to be dominated by the field-modulated domain wall motions. This work paves a potential way toward practical spin–orbit torque-based memory, oscillating, and logic devices.
Regularized second-order correlation methods for extended systems
Authors: Keller Elisabeth , Tsatsoulis Theodoros , Reuter Karsten , Margraf Johannes T.
Published: December 2021

Second-order Møller–Plesset perturbation theory (MP2) constitutes the simplest form of many-body wavefunction theory and often provides a good compromise between efficiency and accuracy. There are, however, well-known limitations to this approach. In particular, MP2 is known to fail or diverge for some prototypical condensed matter systems like the homogeneous electron gas (HEG) and to overestimate dispersion-driven interactions in strongly polarizable systems. In this paper, we explore how the issues of MP2 for metallic, polarizable, and strongly correlated periodic systems can be ameliorated through regularization. To this end, two regularized second-order methods (including a new, size-extensive Brillouin–Wigner approach) are applied to the HEG, the one-dimensional Hubbard model, and the graphene–water interaction. We find that regularization consistently leads to improvements over the MP2 baseline and that different regularizers are appropriate for the various systems.
The collective motion of thermophoretic-type active particle suspension under spatial–temporal modulation
Authors: Io Chong-Wai , Shane Yu-Xuan , Tang Yu-Sheng
Published: December 2021

The mesoscopic collective behavior of a thermophoretic-type active particle suspension under a spatial–temporal modulated excitation field is experimentally studied. By using a digital light processing chip, a sinusoidal-like spatial–temporal varying laser pattern (intensity wave) is projected on the particle suspension to modulate the particle propulsion strength through the thermophoretic effect and to exert spatial confinement through the optical trapping effect. For static and slow (wave speed ≪ particle propulsion speed) modulations, in contrast to the passive particles trapped around the wave crest, the self-propulsion strength splits the particle distribution into two branches adjacent to the edges of confinement similar to the bacteria system, and the profile of particle distribution moves coherently with the modulation wave. Once the wave speed increases to the order of the particle propulsion speed, the splitting of particle distribution disappears. Furthermore, it is remarkable that the forward propagating modulation-induced certain fraction of backward streaming particles are observed. This is a generic behavior of a self-propelling active particle suspension, which is not found in the bacteria system. This finding should be useful for particle manipulation at the mesoscopic scale.
Speciation and mobility of antimony and arsenic in a highly contaminated freshwater system and the influence of extreme drought conditions
Authors: Doherty Steven , Tighe Matthew K. , Milan Luke A. , Lisle Leanne , Leech Calvin , Johannessen Bernt , Mitchell Valerie , Hamilton Jessica , Johnston Scott G. , Wilson Susan C.
Published: December 2021

Environmental context Toxicity and mobility of antimony and arsenic in aqueous systems are largely determined by their speciation and redox chemistry. In a highly contaminated freshwater system, one antimony species (dissolved SbV) dominated, while dissolved arsenic was more responsive to environmental conditions. Arsenic (as AsV) increased significantly during a drought period; this increase in As mobility presents a threat for first flush events and water contamination in a changing climate. Abstract Aqueous and solid-state antimony (Sb) and arsenic (As) speciation is assessed in an Australian freshwater system contaminated by mining of primary sulfide minerals. The study aims to understand metalloid transformation and mobilisation in the system, and coincides with a severe drought providing the opportunity to examine the influence of extreme low-flow conditions. X-ray absorption spectra identified only SbV in <2 mm sediments, despite boulder size stibnite evident in the creek. Roméite-group minerals were detected by X-ray diffraction in oxidation rims of creek-bed stibnite, which potentially limit the contribution of dissolved SbIII to the waterway. Arsenic in <2 mm sediments was dominated by AsV (17–91 %) and orpiment (16–93 %), while the co-occurrence of AsIII (11–36 %) with orpiment suggests that primary As minerals are an important ongoing source of AsIII to the system. Dissolved metalloids (<45 µm filtered) dominated total water column concentrations and comprised mainly pentavalent species. Arsenic(III) was however identified in most water samples (up to 6.6 µg L−1), while dissolved SbIII was only detected in one sample (3.4 µg L−1) collected during the drought period. Dissolved AsV increased significantly in samples collected in low-flow conditions, considered a result of reductive dissolution of sediment Fe-oxyhydroxide host phases, but a similar increase in dissolved Sb was not observed. This study highlights a greater risk from As in this system, and the likelihood of increased As mobility under the warmer and drier environmental conditions predicted with climate change, especially during first-flush events.
On the sparsity of fitness functions and implications for learning
Authors: Brookes David H. , Aghazadeh Amirali , Listgarten Jennifer
Published: December 2021

Significance

The properties of proteins and other biological molecules are encoded in large part in the sequence of amino acids or nucleotides that defines them. Increasingly, researchers estimate functions that map sequences to a particular property using machine learning and related statistical approaches. However, an important question remains unanswered: How many experimental measurements are needed in order to accurately learn these “fitness” functions? We leverage perspectives from the fields of biophysics, evolutionary biology, and signal processing to develop a theoretical framework that enables us to make progress on answering this question. We demonstrate that this framework can be used to make useful calculations on real-world data and suggest how these calculations may be used to guide experiments.
Geologic controls on phytoplankton elemental composition
Authors: Sharoni Shlomit , Halevy Itay
Published: December 2021

Significance

The elemental composition of marine phytoplankton reflects their quality as a food source and regulates the flow of carbon, oxygen, and nutrients between the ocean, atmosphere, and rock reservoirs. Despite this importance, no systematic estimate exists of the geologic history of phytoplankton elemental composition, which is often regarded to have been constant through time, limiting our understanding of evolutionary patterns and global biogeochemistry. Here, using a biogeochemical model forced by geologic and evolutionary events (e.g., the colonization of the continents by plants), we find that the nutrient content of phytoplankton has increased over the last 550 million y of Earth history. This increase in the organic matter nutrient content has likely been important for the evolution of marine fauna.
High-resolution cryo-electron microscopy structure of photosystem II from the mesophilic cyanobacterium,
Synechocystis
sp. PCC 6803
Authors: Gisriel Christopher J. , Wang Jimin , Liu Jinchan , Flesher David A. , Reiss Krystle M. , Huang Hao-Li , Yang Ke R. , Armstrong William H. , Gunner M. R. , Batista Victor S. , Debus Richard J. , Brudvig Gary W.
Published: December 2021

Significance

Photosystem II (PSII) is a photo-oxidoreductase that harnesses light energy to use water to make fuel. Water oxidation occurs at a metal cluster in the active site called the oxygen-evolving complex (OEC). Understanding PSII function has provided design principles for synthetic solar fuel catalysts; however, the details of water oxidation are obscured by the multiple states through which the mechanism proceeds, differences between species, and lability of the OEC. To better understand PSII function, we solved its structure from
Synechocystis
sp. PCC 6803. We observe significant differences compared with PSII from thermophilic cyanobacteria that highlight the need for reexamination of previous data using this structure for interpretation. The structure also provides a platform for studies of site-directed mutations of PSII.
Reframing an author’s image through the style of translation
Authors: Durmuş Hilal Erkazanci
Published: December 2021

This paper seeks to explore how the style of translation reframes an author’s changing image. In light of the
transformation of Latife Tekin from being considered an author of the poor and dispossessed with whom she identifies to being
acknowledged as a translator who channels the marginal world of the dispossessed people into the mainstream, as evidenced in
various paratextual and metatextual discourses in Turkey, the study focuses on the style of the English translation of Tekin’s
Buzdan Kılıçlar (Swords of Ice). The study underlines that an author’s ontological narrative, which feeds
into his or her image, may impact the style of the translation of his or her work. Noting that the style of translation may serve
as a way of responding to an author’s ontological narrative, the study highlights that the stylistic features (i.e., italics and
quotation marks) added to the translation of Buzdan Kılıçlar appear to be in interplay with the narratives that
prepared the ground for Tekin’s self-identification as a translator. Ultimately, the study points out that those stylistic
features foreground not only the cultural other against Turkey’s modern and secular establishment but also the Oriental other
against Western modernity.
Artificial neural network study of the electrical conductivity of mould flux
Authors: Qin Rongshan
Published: December 2021

The electrical conductivity of mould flux with chemical constitution of CaO-SiO2-Al2O3-NaO-K2O-MgO-CaF2-Cr2O3-FeO-MnO has been investigated. The assessed database contains one unitary, five binary, nine ternary, four quaternary, two quinary, two senary and one octonary subsystems. Each constitutional component is in connection to another via some direct or indirect links. A multilayer artificial neural network method was developed and implemented in the database. The work provides a method to calculate the relationships between the composition, temperature and electrical property of the mould flux within the defined parameter ranges. The results have been validated against those experimental data that are not included in the training of the neural networks.
Conformal geometry on a class of embedded hypersurfaces in spacetimes
Authors: Sherif A M , Dunsby P K S
Published: December 2021

In this work, we study various geometric properties of embedded spacelike hypersurfaces in 1 + 1 + 2 decomposed spacetimes with a preferred spatial direction, denoted e

μ
, which are orthogonal to the fluid flow velocity of the spacetime and admit a proper conformal transformation. To ensure non-vanishing and positivity of the scalar curvature of the induced metric on the hypersurface, we impose that the scalar curvature of the conformal metric is non-negative and that the associated conformal factor φ satisfies

φ

^

2

+
2

φ

^

^

>
0

, where

*

^

denotes derivative along the preferred spatial direction. Firstly, it is demonstrated that such hypersurface is either of Einstein type or the spatial twist vanishes on them, and that the scalar curvature of the induced metric is constant. It is then proved that if the hypersurface is compact and of Einstein type and admits a proper conformal transformation, then these hypersurfaces must be isomorphic to the three-sphere, where we make use of some well known results on Riemannian manifolds admitting conformal transformations. If the hypersurface is not of Einstein type and have nowhere vanishing sheet expansion, we show that this conclusion fails. However, with the additional conditions that the scalar curvatures of the induced metric and the conformal metric coincide, the associated conformal factor is strictly negative and the third and higher order derivatives of the conformal factor vanish, the conclusion that the hypersurface is isomorphic to the three-sphere follows. Furthermore, additional results are obtained under the conditions that the scalar curvature of a metric conformal to the induced metric is also constant. Finally, we consider some of our results in context of locally rotationally symmetric spacetimes and show that, if the hypersurfaces are compact and not of Einstein type, then under specified conditions the hypersurface is isomorphic to the three-sphere, where we constructed explicit examples of proper conformal Killing vector fields along e

μ
.
On the slow ionization waves forming the breakdown in a long capillary tube with helium at low pressure
Authors: Akishev Yuri , Alekseeva Tatyana , Karalnik Vladimir , Petryakov Alexander
Published: December 2021

The results of studies of an electrical breakdown leading to the glow discharge ignition in a long capillary quartz tube are presented. Under such conditions, the breakdown completion is preceded by the development of direct, backward, and counter slow ionization waves (IWs) traveling in the tube. The initiation of the waves was created in helium at low pressure (P = 10 Torr) by the high-voltage pulses of positive and negative polarity with amplitude of several kilovolts. In the beginning, the regime without the breakdown completion in the tube was studied. In this regime, the propagation of only direct positive and direct negative IWs happens. The research on dynamics of the direct, backward, and counter positive and negative waves followed by a complete breakdown was done as well. The influence of the pre-existing plasma on the IWs propagation was also studied. The plasma was created in advance by low-current glow discharge being formed in the tube. The instant images of IWs were correlated with the electrical currents formed by the waves, that is, with the displacement current through the dielectric wall and the conductive current through the plasma column. In the experiments, the fine-sectioned electrode wrapped around the lateral tube surface was used. The usage of such electrode allowed one to study the dynamics of the surface charge deposition and deletion happening during the direct and backward wave propagation, respectively. Finally, a strong difference in the spatial structure and velocity of positive and negative direct waves traveling through non-ionized gas was revealed. Contrary, both the positive and negative backward waves traveling through the plasma formed by previous direct waves have the parameters close to each other.