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.

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.

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.

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.

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.

[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.

[Normally functioning ectopic thyroid in adults. Apropos of 4 cases]. / Tiroides ectópico normofuncionante en la edad adulta. A propósito de cuatro casos.

Four cases are presented of ectopic thyroid tissue in adult women who underwent for thyroid study for different motives. Radioisotopic uptake was absent in the usual thyroid location. Thyroid function was normal in every case and no psychomotor abnormalities were present. In one case, echography revealed an atrophic thyroid in the usual location in association with thyroid ectopy. The literature of thyroid ectopy was reviewed and the preponderant role of radioisotopic scan is underlined, together with thyroid echography in the imaging diagnosis of neck masses.

[Pericardial effusion as a possible cause of false positives in I-131 radionuclide scans]. / Derrame pericárdico como posible causa de falso positivo en un rastreo con 131I.

The case of a patient who had undergone surgery for papillary carcinoma of the thyroid is reported. After administering a therapeutic 131I capsule, the radionuclide scan showed a diffuse, "halo-like" thoracic uptake in the precordial region. The patient's normal thyroglobulin levels and the characteristics of radionuclide uptake did not suggest metastasis. Chest radiography and ultrasonography identified pericardial effusion, which was attributed to hypothyroidism.

[Primary bladder diverticula. Study of 47 cases]. / Divertículos vesicales primarios. Estudio de 47 casos.

We report on 47 patients, surveyed and treated by us, diagnosed of primary vesical diverticula, having thus excluded all those secondary to lower obstructive anomalies, such as urethral valves and neurogenic bladder. Only seven out of the 47 patients were females: two of them had a iatrogenic cause and the remainder were of small size and associated with vesicoureteral reflux. All the cases have been documented by means of an intravenous pyelography (IVP), an excretory cystogram and a voiding cystourethrogram (VCUG). Many diverticula may go unnoticed when screened by IVP, whereas the cystogram and preferentially the VCUG are a 100 for 100 diagnostic. A 45 for 100 of these children (22 cases) had an attendant reflux and 23 for 100 (11 cases) had some other concomitant renal disease. Three further cases were iatrogenic, as a result of the methods employed for antireflux ureteral reimplantation. A 77 for 100 of the patients had urinary tract infection demonstrated by a urinary sediment and a positive culture. Surgery was performed on 34 patients, the indication being made on the basis of the big size of the diverticulum, its clinical repercussion, or because of its association with vesicoureteral reflux or any other kidney malformation. We employ an intravesical approach for the small diverticula with attendant reflux, but for resection of the sizeable ones, irrespective of the existence of reflux, we prefer the combined extra and intravesical approach, which allows a most accurate extravesical dissection, as well as the recognition and control of the ureter and the deferes duct, structures both that are usually anatomically distorted.

[Primary cervical tumors of the sympathetic nervous system. Report of 8 cases]. / Tumores cervicales primitivos del sistema nervioso simpático. A propósito de 8 casos.

The authors present his experience in the treatment of 8 patients with primary tumors of cervical sympathetic ganglions. The presence of a hard, painless, adherent and slow evolution latero-cervical mass is the first sign in 7 cases. The other one, a neuroblastoma, had a Horner's syndrome. The authors expose the methods of diagnostic and staging, some characteristics of surgical technique, chemotherapy treatment and follow-up methods (TAC, Gammagraphy with i-MIBG and Tumoral Markers). This imply a survival in the 100% of cases.

[New perspectives in liver-based metabolic errors: liver transplantation]. / Nuevas perspectivas en los errores metabolicos de implantacion hepatica: trasplante hepatico.

Liver transplantation offers an actual alternative to patients end-stage liver disease. The aim of this study is to show our results of liver transplantation in paediatric patients with hepatic-based metabolic disorders. Survival rates in these indications can be high and these good results may enlarge the indications. Liver might transplantation therefore be offered earlier to patients with this kind of metabolic disease.

[Is it necessary to remove polycystic kidneys?]. / Es necesario extirpar los riñones multiquísticos?

The Multicystic Dysplastic Kidney is the most frequent renal congenital anomaly and the second most common cause of an abdominal mass in the newborn. Traditionally, since this pathological entity was described as such by Spene in 1955, early resection has been deemed its best treatment. In the last decade, a conservative approach has been advocated by some authors, except for the patients presenting with concomitant abdominal pain or infection. In our hospital, relying on the support afforded by the echographic assessment of these patients, we have proposed an expectant behaviour in the management of this entity. So far, we have had the opportunity to follow the course of the disease in 15 patients with the diagnosis of Multicystic Dysplastic Kidney, with the result that in no one of them the size of the cystic mass increased, but instead the mass disappeared completely in one case, diminished greatly in three cases, had a moderate decrease in size in eight cases and in just three patients it has not varied in size. No patient has complained of abdominal pain or has become infected. In the face of such findings, we believe that early resection of the multicystic kidney is not warranted if no complications develop.

[Alpha-1-antitrypsin deficiency associated with ruptured aneurysm of the splenic artery]. / Déficit de alfa-1-antitripsina asociado a rotura de aneurisma de la arteria esplénica.

We show a patient with a rupture of splenic artery aneurysm, seven days after liver transplantation for hepatic cirrhosis and portal hypertension secondary to alfa-1-antitrypsin deficiency. We analyse the aneurysm pathology and its relationship with the blood flow through the aneurysm.

[Surgical approach in persistent neonatal pneumothorax]. / Actitud quirúrgica ante el neumotórax neonatal persistente.

837 neonates required mechanical ventilation at the Neonatal Intensive Unit in the last five years. 136 of them developed tension pneumothorax. Authors report our experience in these patients, who underwent next protocol: 1. Early diagnosis. 2. Underwater-seal drainage. 3. Suction drainage. 4. Selective intubation of contralateral bronchus. 5. Surgical closure. We explain step to step the protocol, specially in the 15 neonates who needed surgery. In such cases, surgical survival was 100%, in the postoperative phase 93% and total survival reached 78.5%. Therefore, we recommend surgery closure in patients who maintain pulmonary fistula in spite of an aggressive conservative treatment.