Cascades of Parametric Instabilities in the Tokamak Plasma Edge during Electron Cyclotron Resonance Heating.

We report observations of nonlinear two-plasmon decay instabilities (TPDIs) of a high-power microwave beam, a process similar to half-harmonic generation in optics, during electron cyclotron resonance heating in a tokamak. TPDIs are found to occur regularly in the plasma edge due to wave trapping in density fluctuations for various confinement modes, and the frequencies of both observed daughter waves agree with modeling. Emissions from a cascade of subsequent decays, which indicate a generation of ion Bernstein waves, are correlated with fast-ion generation. This emphasizes the limitations of standard linear microwave propagation models and possibly paves the way for novel microwave applications in plasmas.

Vertical electron cyclotron emission diagnostic on the tokamak à configuration variable.

In this paper, a diagnostic for the measurement of the electron cyclotron emission (ECE) from non-thermal electrons in magnetically confined fusion plasmas is presented. The diagnostic employs a vertical viewing line of sight that allows us to directly infer the energy of the emitting electrons. Previous incarnations of this diagnostic on other machines have been limited by refraction, which can cause stray radiation to enter the line of sight, polluting the signal. By tuning the toroidal magnetic field on the Tokamak à Configuration Variable, TCV, and by carefully selecting the range of frequencies that are used to measure the ECE spectrum, refraction can be mitigated and background radiation power reduced to below the noise power of the instrumentation. A novel technique for calibrating the diagnostic based on plasma measurements and modeling has been developed. The paper will describe the Vertical ECE (V-ECE) diagnostic on TCV, the calibration method, and the first results from the measurements.

[Anterior shoulder instability with Hill-Sachs on-track. Bankart or Bankart-remplissage?] / Inestabilidad anterior de hombro con lesión de Hill-Sachs on-track. ¿Bankart o Bankart-remplissage?

INTRODUCTION: in patients with anterior glenohumeral (GH) instability together with an off-track or engaging Hill-Sachs (HS) defect, Bankart-remplissage (B-R) surgery reduces the recurrence rate when compared to Bankart (B) surgery alone. There is controversy regarding whether the recurrence rate also decreases in patients with on-track or non-engaging Hill-Sachs defects. OBJECTIVE: to compare the recurrence rate and clinical evolution of patients with anterior glenohumeral instability with 'on-track' Hill-Sachs defect treated with either B or B-R surgery. MATERIAL AND METHODS: non-randomized, retrospective, single-center cohort study of patients with anterior glenohumeral instability and on-track Hill-Sachs defect, operated between January 2010 and December 2018. Patients operated with B versus B-R were compared. Recurrence, complications and re-operation were recorded. In addition, VAS, SSV, WOSI and qDASH scores were obtained and compared in both groups. RESULTS: of the 105 patients who met the inclusion criteria, 78 (74.3%) patients had a complete follow-up (52 B and 26 B-R, 4.3 years median follow-up). There was a higher recurrence rate in group B compared to B-R, with this difference not reaching statistical significance (17.3% vs 7.7%, p = 0.21). There were no significant differences in residual pain, feeling of instability, complications or VAS, qDASH, SSV or WOSI scores between both groups. In the subgroup analysis, patients who practiced contact sports and were operated with B showed higher recurrence rates (24.1% vs 0%, p = 0.08) and complications (41.4% vs 18.2%, p = 0.16) when compared to B + R, although these differences were not significant. CONCLUSION: there were no significant differences in recurrence rates and functional evolution between patients with anterior glenohumeral instability operated with B or B-R surgery. Comparative, prospective studies should be performed to establish definitive recommendations.

INTRODUCCIÓN: en pacientes con inestabilidad glenohumeral (GH) anterior con defecto de Hill-Sachs (HS) off-track o enganchante, Bankart-remplissage (B + R) reduce tasa de recurrencia en comparación a Bankart aislado (B). Hay controversia si tasa de recurrencia también disminuye en pacientes con defecto de HS on-track o no enganchantes. OBJETIVO: comparar la tasa de recurrencia y evolución clínica entre la cirugía de B versus B-R en pacientes operados por inestabilidad glenohumeral anterior con defecto de Hill-Sachs on-track. MATERIAL Y MÉTODOS: estudio de cohorte, no randomizado, retrospectivo y unicéntrico, en pacientes operados por inestabilidad glenohumeral anterior, entre Enero 2010 y Diciembre de 2018. Se incluyen sólo pacientes con defecto de Hill-Sachs on-track. Fueron comparados pacientes operados con cirugía de B versus B + R. Se consigna recurrencia, complicación, reoperación y sensación de inestabilidad. Además, se realizan y comparan puntajes de EVA, SSV, WOSI y qDASH. RESULTADOS: de los 105 pacientes que cumplieron criterios de inclusión, 78 (74.3%) realizaron seguimiento completo (52 B y 26 B + R, 4.3 años mediana de seguimiento). Hubo mayor tasa de recurrencia en grupo B en comparación a B + R, siendo esta diferencia no significativa (17.3% versus 7.7%, p = 0.21). No hubo diferencia significativa en dolor residual, sensación de inestabilidad residual, complicaciones o puntajes de escala EVA, qDASH, SSV ni WOSI. En análisis por subgrupo, pacientes con deportes de contacto, B tienen mayor tasa de recurrencia (24.1% versus 0%, p = 0.08) y complicaciones comparadas con B + R (41.4% versus 18.2%, p = 0.16), siendo estas diferencias no significativas. CONCLUSIÓN: no hubo diferencias significativas en tasa de recurrencia y evolución funcional entre cirugía de Bankart aislado o Bankart-remplissage para inestabilidad glenohumeral anterior asociada a defecto de Hill-Sachs on-track. Estudios comparativos, prospectivos deben realizarse para establecer recomendaciones definitivas.

"Snowflake" H mode in a tokamak plasma.

An edge-localized mode (ELM) H-mode regime, supported by electron cyclotron heating, has been successfully established in a "snowflake" (second-order null) divertor configuration for the first time in the TCV tokamak. This regime exhibits 2 to 3 times lower ELM frequency and 20%-30% increased normalized ELM energy (ΔWELM/Wp) compared to an identically shaped, conventional single-null diverted H mode. Enhanced stability of mid- to high-toroidal-mode-number ideal modes is consistent with the different snowflake ELM phenomenology. The capability of the snowflake to redistribute the edge power on the additional strike points has been confirmed experimentally.

Endoscopic sphincterotomy of the major duodenal papilla in acute relapsing pancreatitis associated with pancreas divisum: a case report.

We report a case of acute relapsing pancreatitis associated with pancreas divisum, who underwent major papilla sphincterotomy after failed minor papilla cannulation. Long-term results were satisfactory. The possible explanations of the efficacy of major papilla endoscopic resection in this particular case are discussed.

Risk factors for cardiac and pyloric stenosis after endoscopic submucosal dissection, and efficacy of endoscopic balloon dilation treatment.

BACKGROUND AND STUDY AIMS: Bleeding and perforation are major complications of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC), but post-ESD stenosis represents a severe delayed complication that can result in clinical symptoms such as dysphagia and nausea. The aims of this study were to determine the risk factors and evaluate the clinical treatment for post-ESD stenosis. METHODS: A total of 2011 EGCs resected by ESD at our institution between 2000 and 2005 were reviewed retrospectively. Resection was defined as cardiac when any mucosal defect was located in the squamocolumnar junction, and as pyloric when any mucosal defect was located < 1 cm from the pylorus ring. Post-ESD stenosis was defined when a standard endoscope could not be passed through the stenosis. We examined the incidence of post-ESD stenosis, its relationship with relevant factors, and the clinical course of post-ESD stenosis patients. RESULTS: Post-ESD stenosis occurred with seven of 41 cardiac resections (17 %) and eight of 115 pyloric resections (7 %). Circumferential extent of the mucosal defect of > 3/4 and longitudinal extent > 5 cm were each significantly related to occurrence of post-ESD stenosis with both cardiac and pyloric resections. All 15 affected patients were successfully treated by endoscopic balloon dilation. CONCLUSIONS: A circumferential extent of the mucosal defect of > 3/4 or longitudinal extent of > 5 cm in length were both demonstrated to be risk factors for post-ESD stenosis, in both cardiac and pyloric resections, and endoscopic balloon dilation was shown to be effective in treating post-ESD stenosis.

V-band nanosecond-scale pulse reflectometer diagnostic in the TCV tokamak.

This article describes the realization of a novel approach to short pulse (∼1 ns) reflectometry (SPR) recently implemented in the tokamak configuration variable tokamak. Taking advantage of a fast arbitrary waveform generator and vector-network-analyzer extension modules, the design offers flexibility regarding pulse output frequency, duration, and repetition rate. Such flexibility allows the instrument to overcome traditional SPR spatial sampling limitations while reducing hardware complexity. In order to measure the group-delay of nanosecond-scale pulses, both traditional analog and novel digital sampling techniques have been explored. A group-delay range resolution of 17 ps (2.6 mm) in average over the V-band has been achieved with both timing techniques against a waveguide mirror featuring 10 dB power fluctuations. Direct pulse sampling during L-mode plasmas shows that reflected pulse widths increase only by 4% in average. However, pulse width dispersion does occur in L-mode plasmas and leads to an increase in the group-delay uncertainty up to 40 ps (6 mm). Raw histograms of group-delay data show interesting qualitative changes from the L mode to the H-mode. Frequency spectra of group-delay data allow the identification of macroscopic density fluctuations as well as edge quasicoherent modes during edge-localized mode-free H-modes. Finally, fast changes to the density profile have been measured with microsecond time resolution and subcentimeter spatial resolution in both O and X-mode polarizations.

V-band Doppler backscattering diagnostic in the TCV tokamak.

A variable configuration V-band heterodyne Doppler back-scattering diagnostic has been recently made operational in the tokamak à configuration variable. This article describes the hardware setup options, flexible quasi-optical launcher antenna, data-analysis techniques, and first data. The diagnostic uses a fast arbitrary waveform generator as the main oscillator and commercial vector network analyzer extension modules as the main mm-wave hardware. It allows sweepable single or multi-frequency operation. A flexible quasi-optical launcher antenna allows 3D poloidal (10°-58°) and toroidal (-180° to 180°) steering of the beam with 0.2° accuracy. A pair of fast HE11 miter-bend polarizers allow flexible coupling to either O or X mode and programmable polarization changes during the shot. These have been used to measure the magnetic-field pitch angle in the edge of the plasma by monitoring the backscattered signal power. Ray-tracing simulations reveal an available k⊥ range between 3 and 16 cm-1 with a resolution of 2-4 cm-1. Perpendicular rotation velocity estimates compare well against ExB plasma poloidal rotation estimates from charge exchange recombination spectroscopy.

Inestabilidad anterior de hombro con lesión de Hill-Sachs on-track. ¿Bankart o Bankart-remplissage? / Anterior shoulder instability with Hill-Sachs on-track. Bankart or Bankart-remplissage?

Resumen: Introducción: en pacientes con inestabilidad glenohumeral (GH) anterior con defecto de Hill-Sachs (HS) off-track o enganchante, Bankart-remplissage (B + R) reduce tasa de recurrencia en comparación a Bankart aislado (B). Hay controversia si tasa de recurrencia también disminuye en pacientes con defecto de HS on-track o no enganchantes. Objetivo: comparar la tasa de recurrencia y evolución clínica entre la cirugía de B versus B-R en pacientes operados por inestabilidad glenohumeral anterior con defecto de Hill-Sachs on-track. Material y métodos: estudio de cohorte, no randomizado, retrospectivo y unicéntrico, en pacientes operados por inestabilidad glenohumeral anterior, entre Enero 2010 y Diciembre de 2018. Se incluyen sólo pacientes con defecto de Hill-Sachs on-track. Fueron comparados pacientes operados con cirugía de B versus B + R. Se consigna recurrencia, complicación, reoperación y sensación de inestabilidad. Además, se realizan y comparan puntajes de EVA, SSV, WOSI y qDASH. Resultados: de los 105 pacientes que cumplieron criterios de inclusión, 78 (74.3%) realizaron seguimiento completo (52 B y 26 B + R, 4.3 años mediana de seguimiento). Hubo mayor tasa de recurrencia en grupo B en comparación a B + R, siendo esta diferencia no significativa (17.3% versus 7.7%, p = 0.21). No hubo diferencia significativa en dolor residual, sensación de inestabilidad residual, complicaciones o puntajes de escala EVA, qDASH, SSV ni WOSI. En análisis por subgrupo, pacientes con deportes de contacto, B tienen mayor tasa de recurrencia (24.1% versus 0%, p = 0.08) y complicaciones comparadas con B + R (41.4% versus 18.2%, p = 0.16), siendo estas diferencias no significativas. Conclusión: no hubo diferencias significativas en tasa de recurrencia y evolución funcional entre cirugía de Bankart aislado o Bankart-remplissage para inestabilidad glenohumeral anterior asociada a defecto de Hill-Sachs on-track. Estudios comparativos, prospectivos deben realizarse para establecer recomendaciones definitivas.

Abstract: Introduction: in patients with anterior glenohumeral (GH) instability together with an off-track or engaging Hill-Sachs (HS) defect, Bankart-remplissage (B-R) surgery reduces the recurrence rate when compared to Bankart (B) surgery alone. There is controversy regarding whether the recurrence rate also decreases in patients with on-track or non-engaging Hill-Sachs defects. Objective: to compare the recurrence rate and clinical evolution of patients with anterior glenohumeral instability with 'on-track' Hill-Sachs defect treated with either B or B-R surgery. Material and methods: non-randomized, retrospective, single-center cohort study of patients with anterior glenohumeral instability and on-track Hill-Sachs defect, operated between January 2010 and December 2018. Patients operated with B versus B-R were compared. Recurrence, complications and re-operation were recorded. In addition, VAS, SSV, WOSI and qDASH scores were obtained and compared in both groups. Results: of the 105 patients who met the inclusion criteria, 78 (74.3%) patients had a complete follow-up (52 B and 26 B-R, 4.3 years median follow-up). There was a higher recurrence rate in group B compared to B-R, with this difference not reaching statistical significance (17.3% vs 7.7%, p = 0.21). There were no significant differences in residual pain, feeling of instability, complications or VAS, qDASH, SSV or WOSI scores between both groups. In the subgroup analysis, patients who practiced contact sports and were operated with B showed higher recurrence rates (24.1% vs 0%, p = 0.08) and complications (41.4% vs 18.2%, p = 0.16) when compared to B + R, although these differences were not significant. Conclusion: there were no significant differences in recurrence rates and functional evolution between patients with anterior glenohumeral instability operated with B or B-R surgery. Comparative, prospective studies should be performed to establish definitive recommendations.

Design of tangential viewing phase contrast imaging for turbulence measurements in JT-60SA.

A tangential viewing phase contrast imaging system is being designed for the JT-60SA tokamak to investigate microturbulence. In order to obtain localized information on the turbulence, a spatial-filtering technique is applied, based on magnetic shearing. The tangential viewing geometry enhances the radial localization. The probing laser beam is injected tangentially and traverses the entire plasma region including both low and high field sides. The spatial resolution for an Internal Transport Barrier discharge is estimated at 30%-70% of the minor radius at k = 5 cm-1, which is the typical expected wave number of ion scale turbulence such as ion temperature gradient/trapped electron mode.

Steady-state fully noninductive current driven by electron cyclotron waves in a magnetically confined plasma

A steady-state, fully noninductive plasma current has been sustained for the first time in a tokamak using electron cyclotron current drive only. In this discharge, 123 kA of current have been sustained for the entire gyrotron pulse duration of 2 s. Careful distribution across the plasma minor radius of the power deposited from three 0. 5-MW gyrotrons was essential for reaching steady-state conditions. With central current drive, up to 153 kA of current have been fully replaced transiently for 100 ms. The noninductive scenario is confirmed by the ability to recharge the Ohmic transformer. The dependence of the current drive efficiency on the minor radius is also demonstrated.

[Determination of the "presumptive risk" of hypertensive crisis with fractal interpolation of 24-hour arterial pressure. II: study with secondary hypertensive patients]. / Individuazione del "rischio presuntivo" di crisi ipertensive mediante interpolazione frattalica della pressione arteriosa di 24 ore. II: Studio in ipertesi secondari.

PURPOSE: The present study applies the "fractal interpolation" (FI) to 24-h blood pressure nonivasively and ambulatorily monitored over a day-night period in secondary hypertensives. The purpose is the evaluation of the prevalence for a "presumptive risk" (PR) of hypertensive crisis. MATERIALS AND METHODS: The study was carried out in 108 cases of secondary hypertension, who were non-invasively and ambulatorily monitored for their 24-h blood pressure values. The FI was applied to the time-qualified values of the mean arterial pressure. RESULTS: The PR of hypertensive crisis was found in 11% of the investigated secondary hypertensive patients. Such a risk shows a not significant prevalence in dippers as compared to non-dippers, and in those who showed a significant blood pressure circadian rhythm as compared to those who showed the blood pressure circadian rhythm to be abolished. Additionally, a not significant difference was found between the cases "at risk" and "not at risk" as far as the spectrum of harmonic formants of the 24-h blood pressure pattern is concerned. CONCLUSIONS: The PR of hypertensive crisis is not associated with the dipping/non-dipping phenomenon as well as the circadian rhythmicity of blood pressure. Its occurrence in secondary hypertensives is essentially related to the disorder that is detectable in blood pressure non-linear variability. Therefore, such a risk may be caused by neurovegetative mechanisms which notoriously confer a non-linear chaotic variability to 24-h blood pressure pattern.

[Individualization of the "presumptive risk" of hypertensive crisis using fractals interpolation of the 24-hour arterial pressure. Study of patients with essential hypertension]. / Individuazione del "rischio presuntivo" di crisi ipertensive mediante interpolazione frattalica della pressione arteriosa di 24 ore. I: Studio in ipertesi essenziali.

PURPOSE: The present study applies the "fractal interpolation" (FI) to blood pressure that was nonivasively and ambulatorily monitored over a day-night period in essential hypertensives. The purpose is the identification of cases who are at a "presumptive risk" (PR) for hypertensive crisis. MATERIALS AND METHODS: The investigation was performed on 380 ascertained cases of essential hypertension, who underwent a non-invasive ambulatory monitoring of 24-h blood pressure. The FI was applied to the ambulatory mean arterial pressure. RESULTS: The FI showed that the PR of hypertensive crisis can be found in 14% of the investigated essential hypertensive patients. Such a risk is not significantly higher in dippers as compared to non-dippers, and in those who showed a significant blood pressure circadian rhythm as compared to those who showed the blood pressure circadian rhythm to be abolished. Furthermore, no significant difference was found between the cases "at risk" and "not at risk" as far as the spectrum of harmonic formants of the 24-h blood pressure pattern is concerned. CONCLUSIONS: The PR of hypertensive crisis is not correlated to the dipping/nondipping condition, circadian rhythmicity and complex harmonic structure of 24-h blood pressure pattern. Its occurrence depends essentially from the disorder that is detectable in 24-h blood pressure pattern. Therefore, such a PR in essential hypertensives may be attributed to the mechanisms, likely neurovegetative, which confer a non-linear chaotic variability to 24-h blood pressure values.

[Identification of "presumptive risk" of hypertension crises with fractal interpolation of the 24-hour arterial pressure. III: study of normotensive subjects]. / Individuazione del "rischio presuntivo" di crisi ipertensive mediante interpolazione frattalica della pressione arteriosa di 24 ore. III: studio in soggetti normotesi.

PURPOSE: The present study is devoted to identify the normotensive subjects who are at a "presumptive risk" (PR) for hypertensive crisis, by applying the "fractal interpolation" (FI) to blood pressure 24-h pattern. MATERIALS AND METHODS: The investigation was performed on 109 ascertained cases of normotension, who underwent a non-invasive ambulatory monitoring of their 24-h blood pressure, by applying the FI to their daily mean arterial pressure. RESULTS: The study showed that the PR for hypertensive crisis can be found in 12% out of the investigated normotensives. The proportion of such a risk is not significantly higher in non-dippers as compared to dippers. Vice versa, the prevalence of cases with a PR for hypertensive crisis was found to be significantly increased in normotensives who were deprived by a significant blood pressure circadian rhythm as compared to those who showed the blood pressure circadian rhythm to be preserved. Furthermore, the cases "at risk" were found to show a different spectrum for the harmonic formants which compose the complex harmonic structure of the blood pressure 24-h variability. CONCLUSIONS: The PR for hypertensive crisis in normotensives seems to be increased by the loss of the blood pressure circadian rhythm, due to a change in the harmonic structure which confers the 24-h periodicity to the hemodynamic variable. This means that the abrogation of the blood pressure circadian rhythm in conditions of normotension promotes an adjunctive disorder for which the PR for hypertensive crisis is augmented.

[Daily sensation of hunger, before and after phototherapy, in subjects with depression-type seasonal affective disorder]. / La sensazione giornaliera di fame, prima e dopo fototerapia, in soggetti affetti da disordine affettivo stagionale--tipo depressione.

OBJECTIVE: The present study investigates the daily pattern of hunger sensation (HS) in women affected by "seasonal affective disorder--depression type" (SAD-DT), before and after therapeutic exposure to bright light (phototherapy). The aim is to detect whether there are disorders in daily HS during the active phase of the disease which can be normalized by an effective treatment of the depressive status, via phototherapy. MATERIALS AND METHODS: Volunteered for the study 4 women affected by SAD-DT, 32-58 years old (BMI: 17.8-29.6 Kg/m2); 10 clinically healthy women (CHW), 21-52 years old (BMI: 23 e 25 Kg/m2) were recruited as controls. Both of the SAD-DT patients and CHW were asked to compile the "orexigram", which was chronobiometrically analyzed by means of the 1. conventional statistical methods; 2. rhythmometric analysis; 3. spectral analysis. RESULTS: Before phototherapy, the SAD-DT patients were found to be characterized by an increased HS (hyperorexia), with the circadian rhythm of the orectic stimulus (OS) which is shifted in its acrophase, being prone to become "free running". After phototherapy, the SAD-DT patients were found to show a little insignificant decrease in their OS, which still maintains a delayed phase in its circadian rhythm as well as the tendency to be "free running". CONCLUSIONS: The pre-treatment findings suggest that the SAD-DT patients are affected by hyperorexia associated with a "phase-shift" for the circadian periodicity of their HS, which is prone to the desynchronization. Such a dyschronism reinforces the hypothesis that the SAD-DT may be pathogenetically sustained by a mechanism of "phase-shift". The post-treatment findings suggest that both the hyperorexia and dyschronism of the orectic circadian rhythm are uncorrected by the phototherapy, even though the SAD-DT patients seem to have had beneficial antidepressive effects from the therapeutic intervention. The persisting dyschronism indicates that the photic stimulus is not able to completely reset the biological clock of the suprachiasmatic nuclei, at least for the phasic modulation of the HS circadian rhythm. The orexigram, thus, could be enclosed among the clinical tools in order to assess the complete efficacy of the phototherapy in SAD-DP patients.

Circadian rhythm of hunger sensation in patients affected by dysthymic disorder.

PURPOSE: The present study investigates the daily pattern of hunger sensation (HS), namely orexia, in patients affected by "Dysthymic Disorder" (DD). The aim is to detect whether there are changes in the circadian rhythm (CR) of HS, herein investigated as a "marker rhythm", that can reveal a dysfunction of the "circadian biological clock" (CBC). In such a circumstance, one could be authorised to suggest a resynchronizing therapy, via antidepressant chronizing drugs and/or morning exposure to bright light, as it is currently done in other types of human depression, having a documented dysfunction of the CBC. MATERIALS AND METHODS: Volunteered with informed consent for the study 6 women (age = 34-56 years; mean BMI = 22.7 +/- 4.8 kg/m2) affected by DD. 10 clinically healthy women (CHW, age = 21-52 years; mean BMI = 24.0 +/- 0.5 kg/m2) were recruited as the controls. Both of the dysthymic patients (DP) and CHW were asked to compile the "orexigram", which was chronobiometrically analyzed by means of the 1. conventional statistical methods; 2. rhythmometric analysis for the CR; 3. spectral analysis for the harmonic components of the orexigram. RESULTS: The DP were found to be characterized by a normal daily level of HS, with 1. the CR of the orectic stimulus to be preserved and well located in its acrophase, and 2. the spectrogram of the orexigram to be substantially well configured. CONCLUSIONS: The above-cited results suggest that the DP show no alterations in the HS marker rhythm that can be taken as an evidence for declaring that the DD is not characterized by a relevant dysfunction of the CBC. Lacking in particular a phase-shift in HS marker rhythm, it can be argued that the DD is an affective disorder for which a resynchronizing therapy (exposure to bright light or pharmacological chronizers) seems to be "a priori" not indicated.