569 research outputs found
Development of diagnostic and manipulation systems for space-charge dominated electron beams and confined electron plasmas in ELTRAP
No full textModifications have been implemented in the Penning-Malmberg device ELTRAP aimed
at performing studies on the dynamics of space-charge dominated nanosecond electron bunches traveling along the magnetic field. In particular, a Thomson backscattering apparatus has been developed where an infrared (IR) laser pulse collides with the bunched electron beam. The frequency-shifted
backscattered radiation, acquired by means of a photomultiplier (PMT), can be exploited to evaluate information on energy, energy spread and density of the bunch. The achievable sensitivity
of the diagnostics has been estimated, and valuable information on the main parameters affecting the signal-to-noise (S/N) ratio has been obtained [B. Paroli, F. Cavaliere, M. Cavenago, F. De Luca, M. Ikram, G. Maero, C. Marini, R. Pozzoli, and M. Romé, JINST 7, P01008 (2012)]. A series of upgrades are under way, aimed at increasing the S/N ratio through the use of a new laser for the electron source, the insertion of a stray light shield, and the optimization of the detection electronics. Moreover, electromagnetic simulations relevant to the design and implementation of a microwave
heating system are presented. The generation of an electron plasma in ELTRAP by means of a low-power radio frequency (RF) drive in the MHz range applied on one of the trap electrodes and under ultra-high vacuum (UHV) conditions has previously been demonstrated [B. Paroli, F. De Luca,
G. Maero, F. Pozzoli, and M. Romé, Plasma Sources Sci. Technol. 19, 045013 (2010)]. The new heating system will allow the extension of the RF studies to the GHz range and in particular the
production of a more energetic electron plasma via cyclotron resonant excitation
Hepatitis C virus infection and autoimmune diseases
No full textMarino Paroli,1 Gino Iannucci,2 Daniele Accapezzato21Department of Biotechnology and Medical-Surgical Sciences, 2Department of Internal Medicine and Medical Specialties, Sapienza University of Rome, ItalyAbstract: Hepatitis C virus (HCV) infection is associated with a number of extrahepatic disorders. The most studied conditions associated with HCV are type II mixed cryoglobulinemia and B cell lymphoma. However, many reports suggest that HCV might also be associated with a number of autoimmune disorders, both organ-specific and not organ-specific. Although concomitant treatment of HCV infection is a confounding factor when ascertaining the actual role of HCV in inducing autoimmune disease, a considerable amount of experimental data indicates that HCV is able to subvert the immune system and consequently induce autoimmunity. In the present review, we report a series of observations which associate chronic HCV infection with the onset of autoimmune disorders.Keywords: hepatitis C virus, immune regulation, autoimmune disease
Non-resonant dynamic stabilization of the m=1 diocotron mode
No full textThe m=1 diocotron mode of a nonneutral plasma column confined in a Malmberg-Penning trap, i.e. the rotation of the plasma center-of-charge around the longitudinal symmetry axis, is experimentally found to be unstable. We have investigated in the ELTRAP device a control mechanism of the radial drift of the column based on a Radio Frequency drive applied on an azimuthally sectored electrode of the trap. Systematic experiments show the characteristic features of the mechanism, namely the presence of amplitude and frequency thresholds as well as the non-resonant behavior, whose interpretation invokes the concept of dynamic stabilization
Clinical use of biologics in vasculitis syndromes
No full textMarino ParoliDivision of Clinical Immunology and Rheumatology, Department of Biotechnology and Medical-Surgical Sciences, Sapienza University of Rome, ItalyAbstract: Vasculitis syndromes are relative rare conditions but can cause significant mortality and morbidity if not treated adequately. Recent advances in immunosuppressant therapy have radically changed the course of these diseases. However, the standard therapy is not always well tolerated by patients, and some cases are refractory to treatment. New therapeutic possibilities have emerged with the use of so-called "biologics," a new class of genetically engineered drugs used for inflammatory rheumatic diseases, including rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis. In the present review, summarized are the most recent data on the efficacy and safety of biologics in the treatment of vasculitis syndromes that cannot be treated with standard therapy.Keywords: anti-TNF-alpha, rituximab, tocilizumab, vasculitide
When autoantibodies are missing. the challenge of seronegative rheumatoid arthritis
No full textSeronegative rheumatoid arthritis (SNRA) is characterized by the absence of both rheumatoid factor (RF) and antibodies against the cyclic citrullinated protein (ACPA) in serum. However, the differences between the two forms of RA are more complex and have not yet been definitively characterized. Several lines of evidences support the idea that there are specific elements of the two forms, including genetic background, epidemiology, pathogenesis, severity of progression over time, and response to therapy. Clinical features that may differentiate SNRA from SPRA are also suggested by data obtained from classical radiology and newer imaging techniques. Although new evidence seems to provide additional help in differentiating the two forms of RA, their distinguishing features remain largely elusive. It should also be emphasized that the distinctive features of RA forms, if not properly recognized, can lead to the underdiagnosis of SNRA, potentially missing the period called the "window of opportunity" that is critical for early diagnosis, timely treatment, and better prognosis. This review aims to summarize the data provided in the scientific literature with the goal of helping clinicians diagnose SNRA as accurately as possible, with emphasis on the most recent findings available
Predicting SARS-CoV-2 infection trend using technical analysis indicators
No full textObjective:Coronavirus disease 2019 (COVID-19) pandemic is a global health emergency caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This study aimed to evaluate whether technical analysis (TA) indicators, commonly used in the financial market to spot security price trend reversals, might be proficiently used also to anticipate a possible increase of SARS-Cov-2 spread.Methods:Analysis was performed on datasets from Italy, Iran and Brazil. TA indicators tested were: 1) the combined use of a faster (3-days) and a slower (20-days) simple moving averages (SMA). 2) the Moving Average Converge/Divergence/MACD. 3) the divergence in the direction of the number of new daily cases trend and the corresponding MACD histogram.Results:We found that the use of both fast/slow SMAs and MACD provided a reliable signal of trend inversion of SARS-Cov-2 spread. Results were consistent for all the three countries considered. The trend reversals signaled by the indicators were always followed by a sustained trend persistence until a new signal of reversal appeared.Conclusions:TA indicators tested here proved to be reliable tools to identify in the short mid-term a subsequent change of direction of viral spread trend either downward, upward or sideward
Considerazioni preliminari sugli adattamenti del "Pater noster" nel medioevo germanico
No full textVersioni e/o commenti del "Pater noster" nelle lingue germaniche dell'alto medioev
Stabilizing effect of a nonresonant radio frequency drive on the m=1 diocotron instability
No full textIt has been experimentally shown that the rotation radius of a non-neutral plasma column around the longitudinal axis of a Malmberg–Penning trap experiences a growth in amplitude (m = 1 diocotron instability), leading to the loss of the plasma on the surface of the confining electrodes. A new stabilization mechanism has been investigated with the help of systematic experiments in the ELTRAP (ELectron TRAP) device where a high-frequency, low-amplitude drive has been applied on an azimuthally sectored electrode. An effective confining force is created, which reduces the offset of the column from the center. This interpretation and its theoretical analysis show a qualitative agreement with the experimental findings, where a net confinement effect is present for a wide range of drive amplitudes and frequencies
The Book Structure od Olaus Magnus's "Historia": The Case of Book XVI
No full textAnalisi della struttura del libro XVI della "Historia" di Olao Magno come esempio del metodologia compositiva dell'autor
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