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Highlights • EBV reactivation was observed in patients with COVID-19. • NK + and CD8 + T cell reduction was related to the severity of COVID-19 infection. • An increase of B cells in patients with severe symptoms was documented., Objectives The immunologic profile and opportunistic viral DNA increase were monitored in Italian patients with COVID-19 in order to identify markers of disease severity. Methods A total of 104 patients infected with SARS-CoV-2 were evaluated in the study. Of them, 42/104 (40.4%) were hospitalized in an intensive care unit (ICU) and 62/104(59.6%) in a sub-intensive care unit (SICU). Human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV), Parvovirus B19 and Human Herpesvirus 6 virus reactivations were determined by real-time PCR, and lymphocyte subpopulation counts were determined by flow cytometry. Results Among opportunistic viruses, only EBV was consistently detected. EBV DNA was observed in 40/42 (95.2%) of the ICU patients and in 51/61 (83.6%) of the SICU patients. Comparing the two groups of patients, the EBV DNA median level among ICU patients was significantly higher than that observed in SICU patients. In parallel, a significant reduction of CD8 T cell and NK count in ICU patients as compared with SICU patients was observed (p

Background The COVID-19 pandemic and the subsequent national lockdowns, school closures and distance learning may have had both negative and positive effects on physical and mental health of children. Methods A cross-sectional study was conducted on a large group of children between 1 and 10 years old in Lombardy, Italy (n = 3392). Their parents filled in a survey answering single or multiple-choice questions about their offspring’s behavior changes (including sleep, dietary habits, emotional disturbances), relationship with siblings, parents and peers, the use of digital technologies, and distance learning experience during the lockdown. Results Parents reported lifestyles and emotional alterations during the lockdown. The modifications of family relationships, parents’ remote working, and screen time were associated with sleep, emotional and behavioral modifications. Distance learning was overall considered adequate. Conclusions This study reported the most updated data on the effects of COVID-19 pandemic lockdown on children between 1 and 10 years of age in a large sample of Italian schoolchildren. The results of this study point out that pediatricians and authorities should support relationships within families during the COVID-19 pandemic. Parents’ remote working might play an important role for this purpose.

The Organisation for Economic Co-operation and Development is initiating the International Early Learning Study, a cross-national assessment of early learning outcomes involving the testing of 5-year-old children in participating countries. The authors use this colloquium to inform members of the early childhood community about this project and to raise concerns about its assumptions, practices and possible effects. The authors also invite readers’ comments, to start a process of democratic dialogue and contestation.

The quasi-optical beam launching antenna for the Electron Cyclotron Resonance Heating (ECRH) experiment at 140 GHz, 1.6 MW to the plasma, on the Frascati Tokamak Upgrade (FTU) has been successfully exploited in experimental operations. It provides four beams 400 kW each, with independent poloidal and toroidal steering capability and a maximum power density of 60 kW/cm2 at the plasma edge. The beam radius in the plasma is ≈20 mm, allowing a very high localisation of the absorbed power. The main characteristics of the antenna are: • Four movable launching mirrors under vacuum, far from the plasma edge (no movable parts near the plasma). • Oblique toroidal injection capability at fixed angles obtained with reflections on two fixed stainless steel plates, gold plated, inserted at the sides of the port. • Vacuum gate separating the main vacuum from the appendix containing the two matching mirrors and the barrier window (for safety and maintenance). • All movements are transferred outside the vacuum chamber through bellows and linear displacement. Actuators and encoders are in air. • Full capability to adjust small movements of the machine during cool-down and warm-up, preserving the alignment. Pattern measurements at low power before installation were performed to characterise the effects of the real system on the ideal shape and the polarisation of the launched beams, with particular attention to diffraction effects. Final control of the shape of the beams and the alignment of the mirrors in the system is performed after installation, under vacuum and with the tokamak at liquid nitrogen temperature, with the aid of a retractable probe and using a thermopile as the RF detector.

A 12‐channel grating polychromator for the measurement of electron cyclotron emission on the Frascati tokamak upgrade (FTU) has been built. Three gratings can be exchanged remotely, to allow the instrument to cover three different spectral ranges (between 200 and 600 GHz) which correspond to the second harmonic of electron cyclotron emission for tokamak magnetic fields of 4, 6, and 8 T. Three sets of low‐pass filters, whose cut‐off frequencies are optimized for each grating, are used to cut the high diffraction orders. In order to exchange the filters together with the grating it was necessary to integrate the groups of filters with the polychromator itself. This has been done reducing the grating sizes and assembling them all closely on a moveable structure. The exchange of gratings and filters can be performed remotely via computer in few seconds without any lost of the alignment. InSb cryogenic hot‐electron bolometers are used as detectors. The cryostat hold‐time is more than 30 days. Spectral resoluti...

A new electron cyclotron (EC) antenna for real time control experiments on FTU tokamak has been tested at IFP-CNR laboratory. mm-Wave characterization was performed at the operating frequency of 140 GHz with low power measurements, primarily to test the internal optics of the launcher in terms of focusing properties and beam directivity. The antenna is devoted to the injection of high power EC waves in different working configurations using a front steering setup. The beam direction is controlled with a fast mirror (steerable both toroidally and poloidally) and the available launching angles have been determined to fix the steering mirror working space. Beam dimension can also be controlled, using a sliding structure in the plug-in system, equipped with a focusing mirror that provides zooming capabilities. This paper contains results of low power tests performed on the antenna in order to characterize the launcher in its quasi-optical design. Beams are found to be slightly astigmatic (maximum ratio w(y)/w(x) = 1.1) and with an expected beam radius in the plasma ranging from 18.6 to 26.0 mm due to cited zooming effects. Additional beam patterns and linear scans of the launched mm-wave power for different injection angles have been measured, in some cases in realistic conditions (using a mock-up of the FTU port provided with metallic side-walls) to evaluate diffraction and beam truncation effects. (C) 2011 EURATOM ENEA - CNR - Association/Instituto di Fisica del Plasma. Published by Elsevier B.V. All rights reserved.

The development of electron cyclotron resonance heating (ECRH)-electron cyclotron current drive (ECCD) as a tool for suppression of plasma instabilities requires that the millimeter-wave beams used for testing magnetohydrodynamic (MHD) stabilization schemes for ITER be able to follow magnetic island position in real time. In the FTU tokamak, the design of a new ECRH fast-steerable launcher will enable a fast-controlled trolled deposition at a precise poloidal location and the inclusion of the mirror motion in a feedback loop aimed at MHD stabilization. Two of the four existing transmission lines will be switched to the new launcher located in a different equatorial port. It will launch two independent beams with radius in the plasma changeable between 17 and 28 mm, in order to control the deposited power density. Real-time control of the poloidal steering requires high acceleration, speed, and positioning precision of the last mirror. Additionally, oblique toroidal injection at precise angles will allow current profile shaping through controlled ECCD and heating of overdense plasmas (n(e) > 2.4 X 10(20) m(-3)) using electron Bernstein waves. For optimal 04 conversion, the required toroidal angle, estimated with dedicated beam-tracing calculations, is close to +/-38.5 deg, near the upper limit in the toroidal steering angle. The launch requirements and their impact on the launcher design phase are presented in the paper.

The present ECRH launcher installed on a single equatorial port of FTU tokamak was designed to inject four beams independently steered continuously in poloidal direction and in a set of predetermined toroidal angles. The launching mirrors can be moved only shot by shot. New experimental programmes for control of MHD instabilities with ECH/ECCD and heating of over-dense plasmas with ECBW require new launcher respectively with fast-steerable mirrors and increased toroidal capabilities. The required scanning speed for tracking the rational surfaces in the FTU plasma is 1 cm in 10 ms in poloidal direction, while the maximum toroidal angle needed for O–X–B heating scheme is around ±40°. Two ECRH lines, feeding the old launcher, will be switched to the new launcher, located in a different equatorial position, capable of launching two independent beams from small movable mirrors in the plasma proximity. A control on the power deposition width will be achieved by changing the beam radius in the plasma using an optical system composed by two mirrors (zooming range 17–28 mm). Place has been reserved for future arrangements of additional components, e.g. a remote steering waveguide. A dedicated feedback control for the poloidal motion of the launching mirrors is being developed, in order to adapt the tracking of the power deposition location to the dynamic changes of magnetic surfaces in real-time. The maximum toroidal angle impacts strongly on the movable mirror design; dimensions (height around 90 mm, width around 54 mm) are limited by the port width (=80 mm) and the need to preserve the maximum steering angle. Since the mirrors will not be actively cooled, temperature control will be achieved by covering the backside with a high emissivity coating, to obtain an efficient radiative cooling. A detailed description of the launcher is presented in the paper.

The 140GHz, 2MW, 0.5s ECRH system on FTU tokamak integrates closed waveguide transmission lines (≈30 m) with quasi optical systems at both ends for efficient coupling from the 4 gyrotrons to the 4 waveguides and from these to the plasma through a single access port. Poloidal and toroidal control of the beam’s launching angles and polarization is performed without movable components close to the plasma. Most of the components of each generation and transmission system were designed to operate at a power level higher than 0.5 MW, and a possible up-grade to a full 1 MW, 0.5 s capability is discussed.

In single and polycrystals of «pure» Ih ice, large cracks were mechanically produced along prismatic planes; at the same time large potential changes (up to 40 volt) were measured on the surface of the sample. The decay of the potential observed under isothermal and constant warming rate conditions led to the hypothesis of a polarization associated with a dislocation motion activated by Bjerrum defects. The activation energy found ((0.20 ± 0.02) eV) is close to the values reported in the literature for the migration of these defects. It is pointed out that such a phenomenon may take part in thunderstorm electrification.

A high-throughput high-resolution curved crystal spectrometer for measurements in the soft X-ray range on fusion magnetic devices is described. The spectrometer uses a large useful area (8 × 5 cm 2 ) quartz lamina bent at a curvature radius 385 cm long as the dispersing element. The detector is a one-dimensional space resolving multiwire proportional counter. The spectral resolving power is R = 18 000, permitting to obtain adequate ion temperature measurements, down to 700 eV, from the Doppler broadening of resonance lines of highly ionized metallic impurities.

The effect of edge dislocations on the capacitance of surface barrier diodes made of n-germanium is investigated as a function of temperature. It is shown that the edge dislocations decrease the diode capacitance and that, at large reverse bias, from this decrease the occupation ratio f(T) of the dislocation levels can be obtained. Similar results are also obtained from Hall effect measurements made on the same samples previously measured by the capacitance method, thus indicating that the latter method is a valid alternative to the former in the study of the electrical properties of dislocations in semiconductors. The results are also in quantitative agreement with those already found by other authors and lend support to the model of a partially filled dislocation band in germanium, with a neutral level 0.09 eV above the top of the valence band. Es wird der Einflus von Stufenversetzungen auf die Kapazitat von Oberflachenbarrieren-Dioden aus n-leitendem Germanium in Abhangigkeit von der Temperatur untersucht. Es wird gezeigt, das die Stufenversetzungen die Dioden-Kapazitat verringern und das bei groser Sperrspannung aus diesem Abfall das Besetzungsverhaltnis f(T) der Versetzungsniveaus erhalten werden kann. Ahnliche Ergebnisse werden auch aus Hall-Effektsmessungen an den gleichen Proben erhalten, die vorher mit der Kapazitats-Methode gemessen wurden, was darauf hinweist, das die letztere Methode eine gultige Alternative zur ersteren bei der Untersuchung der elektrischen Eigenschaften von Versetzungen in Halbleitern ist. Die Ergebnisse befinden sich auch in quantitativer Ubereinstimmung mit den von anderen Autoren fruher gefundenen und bestatigen das Modell eines teilweise gefullten Versetzungsbandes in Germanium, mit einem neutralen Niveau bei 0,09 eV oberhalb der Valenzbandkante.

Metal silicide Schottky barriers allow reliable and stable rectifying contacts and can be attractive for silicon solar cells from both an economical and a technological point of view. Electrical properties of Pd2Si and PtSi grown on silicon have been investigated as a function of silicide thickness ranging from 20 to 2000 AA. Thick Pd2Si and PtSi films show resistivity of 43 and 35 mu Omega cm respectively; for thicknesses lower than 100 AA the resistivities increase suggesting a discontinuous structure of the silicide layers. Electrical characteristics and barrier heights of silicide Schottky diodes made on 5 Omega cm n-type silicon are independent of silicide thickness for thicknesses greater than 100 AA, while below this value they are affected by the discontinuity of silicide layers. The photoelectrical response shows a maximum for 150 AA thick PtSi and Pd2Si films.