Active Control of Alfvén Eigenmodes by Externally Applied 3D Magnetic Perturbations.

The suppression and excitation of Alfvén eigenmodes have been experimentally obtained, for the first time, by means of externally applied 3D perturbative fields with different spatial spectra in a tokamak plasma. The applied perturbation causes an internal fast-ion redistribution that modifies the phase-space gradients responsible for driving the modes, determining, ultimately their existence. Hybrid kinetic-magnetohydrodynamic simulations reveal an edge resonant transport layer activated by the 3D perturbative field as the responsible mechanism for the fast-ion redistribution. The results presented here may help to control fast-ion driven Alfvénic instabilities in future burning plasmas with a significant fusion born alpha particle population.

El sistema TriClip para la reparación transcatéter de la válvula tricúspide. Estudio multicéntrico español / The TriClip system for edge-to-edge transcatheter tricuspid valve repair. A Spanish multicenter study

Introducción y objetivos En pacientes con insuficiencia tricuspídea (IT), la reparación transcatéter de la válvula tricúspide (RTVT) mediante el uso de dispositivos «borde a borde» ha experimentado un creciente uso en todo el mundo. Recientemente se ha puesto a disposición un sistema dedicado de RTVT borde a borde. El presente artículo describe la experiencia inicial con este sistema en España. Métodos Estudio multicéntrico prospectivo que incluyen los centros aceptados para el uso del novedoso sistema. Entre junio de 2020 y marzo de 2021 se incluyó a todos los pacientes sometidos a una RTVT con el sistema TriClip en España. El criterio de valoración principal fue la consecución de una reducción de la IT de al menos 1 grado al alta hospitalaria. Resultados Se incluyó a un total de 34 pacientes. La mayoría de ellos refería antecedentes de fibrilación auricular (91%). El objetivo primario se alcanzó en todos los pacientes. La mayoría requirieron uno (47%) o dos clips (44%), con un claro predominio del dispositivo XT (87%) sobre NT (13%). La localización del primer clip fue principalmente anteroseptal (> 90%). Solo un paciente presentó un desprendimiento parcial que pudo ser estabilizado con clips adicionales en el mismo procedimiento. Al alta, la gravedad de la IT fue de grado 2 en el 91% de los pacientes. A los 3 meses, no se detectó ninguna muerte. Al seguimiento, el 88% de los pacientes se encontraban en clase funcional New York Heart Association 2 y el 80% presentaban IT grado 2 residual. Conclusiones La RTVT borde a borde pareció ser eficaz y segura con una reducción sostenida de la IT a los 3 meses. Serán necesarios más estudios para confirmar estos resultados (AU)

Introduction and objectives In patients with tricuspid regurgitation (TR), edge-to-edge transcatheter tricuspid valve repair (TTVR) is the strategy with the highest penetration worldwide. A dedicated edge-to-edge TTVR system has recently become available in Europe. The present study describes the initial experience with the system in Spain. Methods This multicenter study collected individual data from the centers accepted for the use of the novel system within an initial limited release. Between June 2020 and March 2021, all patients undergoing an edge-to-edge TTVR using the TriClip system in Spain were included in the study. The primary endpoint was the achievement of a TR reduction of at least 1 grade at discharge. Results We included 34 patients. Most of them reported a previous history of atrial fibrillation (91%) and only 1 had a pacemaker lead. The primary endpoint (TR reduction of at least 1 grade at discharge) was met in all patients. Most of the patients required 1 (47%) or 2 clips (44%) with a clear predominance of XT (87%) over NT (13%). The location of the first clip was anteroseptal in >90% of the patients. Only 1 patient had a partial detachment, which was stabilized with additional clips in the same procedure. At discharge, TR severity was≤2 in 91% of patients. At 3 months, mortality was nil. Overall, 88% of patients were in New York Heart Association functional class≤2 and 80% had residual TR≤2. Conclusions Edge-to-edge TTVR seemed to be effective and safe with a sustained TR reduction at 3 months. Further studies will be needed to confirm our findings (AU)

Numerical Optimization of a Nanophotonic Cavity by Machine Learning for Near-Unity Photon Indistinguishability at Room Temperature.

Room-temperature (RT), on-chip deterministic generation of indistinguishable photons coupled to photonic integrated circuits is key for quantum photonic applications. Nevertheless, high indistinguishability (I) at RT is difficult to obtain due to the intrinsic dephasing of most deterministic single-photon sources (SPS). Here, we present a numerical demonstration of the design and optimization of a hybrid slot-Bragg nanophotonic cavity that achieves a theoretical near-unity I and a high coupling efficiency (ß) at RT for a variety of single-photon emitters. Our numerical simulations predict modal volumes in the order of 10-3(λ/2n)3, allowing for strong coupling of quantum photonic emitters that can be heterogeneously integrated. We show that high I and ß should be possible by fine-tuning the quality factor (Q) depending on the intrinsic properties of the single-photon emitter. Furthermore, we perform a machine learning optimization based on the combination of a deep neural network and a genetic algorithm (GA) to further decrease the modal volume by almost 3 times while relaxing the tight dimensions of the slot width required for strong coupling. The optimized device has a slot width of 20 nm. The design requires fabrication resolution in the limit of the current state-of-the-art technology. Also, the condition for high I and ß requires a positioning accuracy of the quantum emitter at the nanometer level. Although the proposal is not a scalable technology, it can be suitable for experimental demonstration of single-photon operation.

Self-adaptive diagnostic of radial fast-ion loss measurements on the ASDEX Upgrade tokamak (invited).

A poloidal array of scintillator-based Fast-Ion Loss Detectors (FILDs) has been installed in the ASDEX Upgrade (AUG) tokamak. While all AUG FILD systems are mounted on reciprocating arms driven externally by servomotors, the reciprocating system of the FILD probe located just below the midplane is based on a magnetic coil that is energized in real-time by the AUG discharge control system. This novel reciprocating system allows, for the first time, real-time control of the FILD position including infrared measurements of its probe head temperature to avoid overheating. This considerably expands the diagnostic operational window, enabling unprecedented radial measurements of fast-ion losses. Fast collimator-slit sweeping (up to 0.2 mm/ms) is used to obtain radially resolved velocity-space measurements along 8 cm within the scrape-off layer. This provides a direct evaluation of the neutral beam deposition profiles via first-orbit losses. Moreover, the light-ion beam probe (LIBP) technique is used to infer radial profiles of fast-ion orbit deflection. This radial-LIBP technique is applied to trapped orbits (exploring both the plasma core and the FILD stroke near the wall), enabling radial localization of internal plasma fluctuations (neoclassical tearing modes). This is quantitatively compared against electron cyclotron emission measurements, showing excellent agreement. For the first time, radial profiles of fast-ion losses in MHD quiescent plasmas as well as in the presence of magnetic islands and edge localized modes are presented.

A rotary and reciprocating scintillator based fast-ion loss detector for the MAST-U tokamak.

The design and unique feature of the first fast-ion loss detector (FILD) for the Mega Amp Spherical Tokamak - Upgrade (MAST-U) is presented here. The MAST-U FILD head is mounted on an axially and angularly actuated mechanism that makes it possible to independently adapt the orientation [0°, 90°] and radial position [1.40 m, 1.60 m] of the FILD head, i.e., its collimator, thus maximizing the detector velocity-space coverage in a broad range of plasma scenarios with different q95. The 3D geometry of the detector has been optimized to detect fast-ion losses from the neutral beam injectors. Orbit simulations are used to calculate the strike map and predict the expected signals. The results show a velocity-space range of [4 cm, 13 cm] in gyroradius and [30°, 85°] in pitch angle, covering the entire neutral beam ion energy range. The optical system will provide direct sight of the scintillator and simultaneous detection with two cameras, giving high spatial and temporal resolution. The MAST-U FILD will shed light on the dominant fast-ion transport mechanisms in one of the world's two largest spherical tokamaks through absolute measurements of fast-ion losses.

The last frontier: transcatheter devices for percutaneous or minimally invasive treatment of chronic heart failure.

Heart failure has a high prevalence in the general population. Morbidity and mortality of heart failure patients remain high, despite improvements in drug therapy, implantable cardioverter-defibrillators and cardiac resynchronisation therapy. New transcatheter implantable devices have been developed to improve the treatment of heart failure. There has been a rapid development of minimally invasive or transcatheter devices used in the treatment of heart failure associated with aortic and mitral valve disease and these devices are being incorporated into routine clinical practice at a fast rate. Several other new transcatheter structural heart interventions for chronic heart failure aimed at a variety of pathophysiologic approaches are currently being developed. In this review, we focus on devices used in the treatment of chronic heart failure by means of left ventricular remodelling, left atrial pressure reduction, tricuspid regurgitation reduction and neuromodulation. The clinical evaluations of these devices are early-stage evaluations of initial feasibility and safety studies and additional clinical evidence needs to be gathered in appropriately designed clinical trials.

Three-dimensional axisymmetric cloak based on the cancellation of acoustic scattering from a sphere.

This Letter presents the design, fabrication, and experimental characterization of a directional three-dimensional acoustic cloak for airborne sound. The cloak consists of 60 concentric acoustically rigid tori surrounding the cloaked object, a sphere of radius 4 cm. The major radii and positions of the tori along the symmetry axis are determined using the condition of complete cancellation of the acoustic field scattered from the sphere. They are obtained through an optimization technique that combines genetic algorithm and simulated annealing. The scattering cross section of the sphere with the cloak, which is the magnitude that is minimized, is calculated using the method of fundamental solutions. The low-loss fabricated cloak shows a reduction of the 90% of the sphere scattering cross section at the frequency of 8.55 kHz.

Comment on "Theory of tailoring sonic devices: diffraction dominates over refraction".

Recently, Garcia et al. [Phys. Rev. E 67, 046606 (2003)] studied theoretically several acoustic devices with dimensions on the order of several wavelengths. Those authors also discussed experimental results previously reported by several of us [Phys. Rev. Lett. 88, 023902 (2002)]] and concluded that it is diffraction rather than refraction that is the dominating mechanism explaining the focusing effects observed in those experiments. In this Comment we reexamined their calculations and discussed why some of their interpretations of our results are misleading.

Refractive acoustic devices for airborne sound.

We show that a sonic crystal made of periodic distributions of rigid cylinders in air acts as a new material which allows the construction of refractive acoustic devices for airborne sound. It is demonstrated that, in the long-wave regime, the crystal has low impedance and the sound is transmitted at subsonic velocities. Here, the fabrication and characterization of a convergent lens are presented. Also, an example of a Fabry-Perot interferometer based on this crystal is analyzed. It is concluded that refractive devices based on sonic crystals behave in a manner similar to that of optical systems.

Reflectance properties of two-dimensional sonic band-gap crystals.

An analysis of the reflectance of sonic band-gap crystals consisting of square arrays of rigid cylinders in air is presented. The standing wave formed in front of the structures is studied both experimentally and theoretically. Experiments have been performed with a mobile robotized microphone that obtains pressure maps on the plane perpendicular to the axes of the cylinders. Enhancements of the standing wave ratio (SWR) are observed in frequency regions where attenuation bands appear in zero-order transmission experiments. Also, the SWR presents oscillations that can be related to the finite dimension of the structure (Fabry-Perot effect). Both features are well described by calculations based on a double-scattering approach.

[Hepatobiliary scintigraphy in a case of acute cholecystitis in childhood]. / Gammagrafía hepatobiliar en un caso de colecistitis aguda en la infancia.

Acute cholecystitis is an uncommon disease in childhood. Few cases in patients under 10 years of age have been found in literature. An eight-year old male patient with no history of interest who had acute acalculous cholecystitis was reported. Ultrasonographic and isotopic studies led to the diagnosis and control of the patient's evolution.

Gammagrafía hepatobiliar en un caso de colecistitis aguda en la infancia / Hepatobiliar scintigraphy in a case of acute cholecystitis in childhood

La colecistitis aguda en la infancia es una patología muy poco frecuente. Son pocos los casos clínicos publicados en pacientes menores de 10 años. Presentamos el caso de un niño de ocho años, sin antecedentes de interés, con colecistitis aguda alitiásica. Los estudios ecográficos e isotópicos contribuyeron al diagnóstico y control de la evolución de este paciente (AU)

Hiperprolactinemia como causa de captación mamaria en gammagrafía con 67Ga / Hyperprolactinemia as a cause of breast uptake in 67Ga scintigraphy

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Metastatic follicular thyroid carcinoma to the kidney: a case report.

Clinically detectable well-differentiated metastatic thyroid cancer to the kidney is rare, with only 12 cases reported in the medical literature. The authors report a case of metastatic thyroid carcinoma to the kidney in a patient with widespread dissemination. She underwent total thyroidectomy, radical left nephrectomy, radioactive ablation with I-131, radiotherapy, and thyroid suppression therapy. Well-differentiated thyroid metastatic cancer can be amenable to treatment with successful long-term results.