90 research outputs found

    Caratterizzazione di cristalli dielettrici non lineari per la generazione di microonde con un mode-locked laser

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    Eccitando cristalli dielettrici (KTP, LBO, Niobatio di litio) mediante un laser mode-locked si è rilevata l'emissione di microonde. Verificato che il fenomeno fosse dovuto alle caratteristiche non lineari dei cristalli, l'analisi del segnale nelle microonde al variare delle proprietà del fascio laser ha consentito la caratterizzazione dei cristalli.ope

    Linking water stock in Mediterranean temporary ponds with hydrological balance at landscape scale

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    Water stock in Mediterranean Temporary ponds results from the hydorological balance between direct or indirect rainwater supply (inflow) and losses in the atmosphere, overflow, infiltration (outflow). Losses into the atmosphere are due either to evapotranspiration, which includes evaporation from open water, soil and canopy dampened by the rain and plant transpiration. Our research was aimed to relate the hydrological balance evaluated at landscape scale with the presence and size of over 100 ponds using historical series of meteorological data and satellite images freely available online. The study area is located in Sardinia, on a 44 km2 basaltic plateau, 550 m a.s.l, named Giara di Gesturi

    Hereditary transthyretin amyloidosis: a comprehensive review with a focus on peripheral neuropathy

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    Amyloidoses represent a group of diseases characterized by the pathological accumulation in the extracellular area of insoluble misfolded protein material called “amyloid”. The damage to the tissue organization and the direct toxicity of the amyloidogenic substrates induce progressive dysfunctions in the organs involved. They are usually multisystem diseases involving several vital organs, such as the peripheral nerves, heart, kidneys, gastrointestinal tract, liver, skin, and eyes. Transthyretin amyloidosis (ATTR) is related to abnormalities of transthyretin (TTR), a protein that acts as a transporter of thyroxine and retinol and is produced predominantly in the liver. ATTR is classified as hereditary (ATTRv) and wild type (ATTRwt). ATTRv is a severe systemic disease of adults caused by mutations in the TTR gene and transmitted in an autosomal dominant manner with incomplete penetrance. Some pathogenic variants in TTR are preferentially associated with a neurological phenotype (progressive peripheral sensorimotor polyneuropathy); others are more frequently associated with restrictive heart failure. However, many mutations express a mixed phenotype with neurological and cardiological involvement. ATTRv is now a treatable disease. A timely and definite diagnosis is essential in view of the availability of effective therapies that have revolutionized the management of affected patients. The purpose of this review is to familiarize the clinician with the disease and with the correct diagnostic pathways in order to obtain an early diagnosis and, consequently, the possibility of an adequate treatment

    GEN-O-MA project: an Italian network studying clinical course and pathogenic pathways of moyamoya disease—study protocol and preliminary results

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    Background: GENetics of mOyaMoyA (GEN-O-MA) project is a multicenter observational study implemented in Italy aimed at creating a network of centers involved in moyamoya angiopathy (MA) care and research and at collecting a large series and bio-repository of MA patients, finally aimed at describing the disease phenotype and clinical course as well as at identifying biological or cellular markers for disease progression. The present paper resumes the most important study methodological issues and preliminary results. Methods: Nineteen centers are participating to the study. Patients with both bilateral and unilateral radiologically defined MA are included in the study. For each patient, detailed demographic and clinical as well as neuroimaging data are being collected. When available, biological samples (blood, DNA, CSF, middle cerebral artery samples) are being also collected for biological and cellular studies. Results: Ninety-eight patients (age of onset mean ± SD 35.5 ± 19.6 years; 68.4% females) have been collected so far. 65.3% of patients presented ischemic (50%) and haemorrhagic (15.3%) stroke. A higher female predominance concomitantly with a similar age of onset and clinical features to what was reported in previous studies on Western patients has been confirmed. Conclusion: An accurate and detailed clinical and neuroimaging classification represents the best strategy to provide the characterization of the disease phenotype and clinical course. The collection of a large number of biological samples will permit the identification of biological markers and genetic factors associated with the disease susceptibility in Italy

    Defects in III-N LEDs: experimental identification and impact on electro-optical characteristics

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    III-N light-emitting-diodes (LEDs) are subject of intense investigations, thanks to their high efficiency and great reliability. The quality of the semiconductor material has a significant impact on the electro-optical performance of LEDs: for this reason, a detailed characterization of defect properties and the modeling of the impact of defects on device performance are of fundamental importance. This presentation addresses this issue, by discussing a set of recent case studies on the topic; specifically, we focus on the experimental characterization of defects, and on the modeling of their impact on the electro-optical characteristics of the devices

    Late and Severe Myopathy in a Patient With Glycogenosis VII Worsened by Cyclosporine and Amiodarone

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    Glycogenosis VII (GSD VII) is a rare autosomal recessive glycogen storage disorder caused by mutations in the PFKM gene encoding the phosphofructokinase (PFK) enzyme. A classical form with exercise intolerance, contractures, and myoglobinuria, a severe multisystem infantile form, an hemolytic variant and a late-onset form usually presenting with muscle pain and mild fixed proximal weakness have been reported. We describe a 65-year-old man affected by muscle PFK deficiency who, since the age of 33, presented with exercise intolerance and myoglobinuria. Muscle biopsy showed a vacuolar myopathy with glycogen storage. The biochemical assay of PFK-M showed very low residual activity (6%). Genetic analysis of PFKM gene evidenced the presence of the heterozygote c.1817A>C (p.Asp543Ala) and c.488 G>A (p.Arg100Gln) pathogenic mutations. In his fifth decade, he started cyclosporine after liver transplantation for hepatocellular carcinoma and, then, amiodarone because of atrial fibrillation. In the following years, he developed a progressive and severe muscle weakness, mainly involving lower limbs, up to a loss of independent walking. Muscle MRI showed adipose substitution of both anterior and posterior thigh muscles with selective sparing of the medial compartment. Marked signs of adipose substitution were also documented in the legs with a selective replacement of gemelli and peroneus muscles. The temporal relationship between the patient's clinical worsening and chronic treatment with cyclosporine and amiodarone suggests an additive toxic damage by these two potentially myotoxic drugs determining such an unusually severe phenotype, also confirmed by muscle MRI findings

    Breakdown Walkout in Polarization-Doped Vertical GaN Diodes

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    We demonstrate the avalanche capability and the existence of breakdown walkout in GaN-on-GaN vertical devices with polarization doping. By means of combined electrical and optical characterization, we demonstrate the following original results: 1) vertical p-n junctions with polarization doping have avalanche capability; 2) stress in avalanche regime induces an increase in breakdown voltage, referred to as breakdown walkout; 3) this process is fully-recoverable, thus being related to a trapping mechanism; 4) temperature-dependent measurements of the breakdown walkout identify CN\text{C}_{N} defects responsible for this process; and 5) capacitance deep level transient spectroscopy (C-DLTS) and deep level optical spectroscopy (DLOS) confirm the presence of residual carbon in the devices under test. A possible model to explain the avalanche walkout is then proposed

    New national and regional Annex I Habitat records: from #60 to #82

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    New Italian data on the distribution of the Annex I Habitats are reported in this contribution. Specifically, 8 new occurrences in Natura 2000 sites are presented and 49 new cells are added in the EEA 10 km × 10 km reference grid. The new data refer to the Italian administrative regions of Campania, Calabria, Marche, Piedmont, Sardinia, Sicily, Tuscany and Umbria. Relevés and figures are provided as Supplementary material respectively 1 and 2
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