Handheld Versus Conventional Ultrasound for Assessing Carotid Artery in Routine Volunteers

Objective: The study aimed to estimate the feasibility and accuracy of carotid intima-media thickness (CIMT) and hemodynamic parameters measurement in a handheld ultrasound device.Methods: Utilizing an ex vivo pig carotid artery sample, CIMT was measured with a handheld ultrasound and compared with histopathology. Then we performed a carotid ultrasound on 25 volunteers using a handheld ultrasound device and a conventional ultrasound system. After a week, these volunteers were scanned again by the same observer. Assessments of the max IMT, mean IMT and hemodynamic parameters (PSV, EDV, PI, RI, S/D, ACCEL, AT, TAMEAN) were compared. Intraclass correlation coefficient (ICC) was used to assess inter-device agreement. Repeatability and correlation of mean IMT were analyzed by Bland–Altman Plots and linear correlation analysis. Results: The mean IMT measured from the common carotid artery by handheld ultrasound showed good agreement (ICC=0.79) with conventional ultrasound. Furthermore, we obtained good repeatability and a consistent trend in the mean value of IMT before and after (r = 0.680, P < 0.01). In addition, the max IMT and the hemodynamic parameters (PSV, EDV, S/D, ACCEL, TAMEAN) showed moderate agreement (ICC=0.73, 0.52, 0.58, 0.70, 0.61, 0.51, respectively). The PI, RI and HR values were excellent agreement with conventional ultrasound (ICC=0.80, 0.84, 0.94). Conclusion: About the basic assessment of carotid, the images and parameters obtained using handheld ultrasound showed a moderate to excellent agreement with conventional ultrasound. The handheld ultrasonic devices can be widely used as a diagnostic tool for carotid artery structure and hemodynamics examination.

Pluto’s Atmosphere in Plateau Phase Since 2015 from a Stellar Occultation at Devasthal

A stellar occultation by Pluto was observed on 2020 June 6 with the 1.3 m and 3.6 m telescopes located at Devasthal, Nainital, India, using imaging systems in the I and H bands, respectively. From this event, we derive a surface pressure for Pluto’s atmosphere of p surf = 12.23 − 0.38 + 0.65 μbar. This shows that Pluto’s atmosphere has been in a plateau phase since mid-2015, a result which is in excellent agreement with the Pluto volatile transport model of Meza et al. This value does not support the pressure decrease reported by independent teams, based on occultations observed in 2018 and 2019 by Young et al. and Arimatsu et al., respectively.

Legendre-Galerkin method for the nonlinear Volterra-Fredholm integro-differential equations

The study of solving nonlinear integro-differential equations in Volterra-Fredholm type presents in this paper. The proposed method tends to use Legendre polynomials as a basis in the Galekin method to obtain the numerical solution. We use the Newton method to get the numerical solution of the nonlinear equations resulted from applying the Galerkin method. The comparison of the present study with the existing results in the literature shows an excellent agreement. Numerical examples explain the convergence, applicability, and efficiency of algorithm.

Global electromagnetic turbulence simulations of W7-X-like plasmas with GENE-3D

The GENE-3D code, the global stellarator version of the established GENE framework, has been extended to an electromagnetic gyrokinetic code. This paper outlines the basic structure of the algorithm, highlighting the treatment of the electromagnetic terms. The numerical implementation is verified against the radially global GENE code in linear and nonlinear tokamak simulations, recovering excellent agreement between both codes. As a first application to stellarator plasmas, linear and nonlinear global simulations with kinetic electrons of ion temperature gradient (ITG) turbulence in Wendelstein 7-X were performed, showing a decrease of ITG activity through the introduction of electromagnetic effects via a finite plasma- $\beta$ . The upgrade makes it possible to study a large variety of new physical scenarios, including kinetic electron and electromagnetic effects, reducing the gap between gyrokinetic models and physically realistic systems.

Numerical analysis of wave–structure interaction of regular waves with surface-piercing inclined plates

The Mocean wave energy converter consists of two sections, hinged at a central location, allowing the device to convert energy from the relative pitching motion of the sections. In a simplified form, the scattering problem for the device can be modelled as monochromatic waves incident upon a thin, inclined, surface-piercing plate of length $$L'$$ L ′ in a finite depth $$d'$$ d ′ of water. In this paper, the flow past such a plate is solved using a Boundary Element Method (BEM) and Computational Fluid Dynamics (CFD). While the BEM solution is based on linear potential flow theory, CFD directly solves the Navier–Stokes equations. Problems of this type are known to exhibit near-perfect reflection (indicated by a reflection coefficient $$|R|\approx 1$$ | R | ≈ 1 ) of waves at specific wavenumbers $$k'$$ k ′ . In this paper, we show that the resonant motion of the fluid induces large hydrodynamic forces on the plate. Furthermore, we argue that this low-frequency resonance resembles Helmholtz resonance, and that Mocean’s device being able to tune to these low frequencies does not act like an attenuator. For the case where the water is deep ($$d'>\lambda '/2$$ d ′ > λ ′ / 2 , where $$\lambda '=2\pi /k'$$ λ ′ = 2 π / k ′ ), we find excellent agreement between our simulations and previous semi-analytical studies on the value of the resonant wave periods in deep water. We also find excellent agreement between the excitation forces on the plate computed using the BEM model, analytical results, and CFD for large inclination angles ($$\alpha > 45^\circ $$ α > 45 ∘ ). For $$\alpha \le 15^\circ $$ α ≤ 15 ∘ , both methods show the same trend, but the CFD predicts a significantly smaller peak in the excitation force compared with BEM, which we attribute to non-linear effects such as the non-linear Froude–Krylov force

Study of Some Nuclear Properties of 170-178W Isotopes by Using Interacting Bosons Model-1

We looked into the structure of energy levels for some Tungsten isotopes W the (even-even) and electromagnetically probability transmission for it with the Model of Interacting Bosons type one (IBM-1) to evaluate the nuclear structure for Tungsten isotopes are investigated in this study (170-178W). The data was gathered using an IBM software written in the Fortran programming language The values of the parameters in this computation show that the characteristics of tungsten isotopes fall between the γ_ unstable limit O(6) and the rotational limit SU(3). The energy and branching ratios demonstrate this. The computed results are in very excellent agreement with experimental data for the isotopes under investigation.

Strain induced localization to delocalization transition on a Lieb photonic ribbon lattice

Ribbon lattices are kind of transition systems in between one and two dimensions, and their study is crucial to understand the origin of different emerging properties. In this work, we study a Lieb ribbon lattice and the localization–delocalization transition occurring due to a reduction of lattice distances (compression) and the corresponding flat band deformation. We observe how above a critical compression ratio the energy spreads out and propagates freely across the lattice, therefore transforming the system from being a kind of insulator into a conductor. We implement an experiment on a photonic platform and show an excellent agreement with the predicted phenomenology. Our findings suggest and prove experimentally the use of compression or mechanical deformation of lattices to switch the transport properties of a given system.

Diffraction limited photonic hook via scattering and diffraction of dual-dielectric structures

Photonic hooks have demonstrated to be great candidates for multiple applications ranging from sensing up to optical trapping. In this work, we propose a mechanism to produce such bent structured light beams by exploiting the diffraction and scattering generated by a pair of dielectric rectangles immersed in free space. It is shown how the photonic hooks are generated away from the output surface of the dielectrics by correctly engineering each individual dielectric structure to generate minimum diffraction and maximum scattering along the propagation axis. Different scenarios are studied such as dual-dielectric structures having different lateral dimensions and refractive index as well as cases when both dielectrics have the same lateral dimensions. The results are evaluated both numerically and theoretically demonstrating an excellent agreement between them. These results may open new avenues for optical trapping, focusing and sensing devices via compact and simple dual-dielectric structures.

New solutions for periodic interfacial gravity waves

Two-dimensional periodic interfacial gravity waves travelling between two homogeneous fluids of finite depth are considered. A boundary-integral-equation method coupled with Fourier expansions of the unknown functions is used to obtain highly accurate solutions. Our numerical results show excellent agreement with those already obtained by Maklakov & Sharipov using a different scheme (J. Fluid Mech., vol. 856, 2018, pp. 673–708). We explore the global bifurcation mechanism of periodic interfacial waves and find three types of limiting wave profiles. The new families of solutions appear either as isolated branches or as secondary branches bifurcating from the primary branch of solutions.

Femoral defects in revision hip arthroplasty: a therapy-oriented classification

Introduction The complex field of femoral defects in revision hip arthroplasty displays a lack of standardized, intuitive pre- and intraoperative assessment. To address this issue, the femoral defect classification (FDC) is introduced to offer a reliable, reproducible and an intuitive classification system with a clear therapeutic guideline. Materials and methods The FDC is based on the integrity of the main femoral segments which determine function and structural support. It focuses on the femoral neck, the metaphysis consisting of the greater and lesser trochanter, and the femoral diaphysis. The four main categories determine the location of the defect while subcategories a, b and c are being used to classify the extent of damage in each location. In total, 218 preoperative radiographs were retrospectively graded according to FDC and compared to intraoperatively encountered bone defects. To account for inter-rater and intra-rater agreement, 5 different observers evaluated 80 randomized cases at different points in time. Results A Cohens kappa of 0.832 ± 0.028 could be evaluated, accounting for excellent agreement between preoperative radiographs and intraoperative findings. To account for inter-rater reliability, 80 patients have been evaluated by 5 different observers. Testing for inter-rater reliability, a Fleiss Kappa of 0.688 could be evaluated falling into the good agreement range. When testing for intra-rater reliability, Cohens Kappa of each of the 5 raters has been analyzed and the mean was evaluated at 0.856 accounting for excellent agreement. Conclusion The FDC is a reliable and reproducible classification system. It combines intuitive use and structured design and allows for consistent preoperative planning and intraoperative guidance. A therapeutic algorithm has been created according to current literature and expert opinion. Due to the combination of the FDC with the recently introduced Acetabular Defect Classification (ADC) a structured approach to the entire field of hip revision arthroplasty is now available.