111 research outputs found

    Spatial patterns of landslide dimension: A tool for magnitude mapping

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    AbstractThe magnitude of mass movements, which may be expressed by their dimension in terms of area or volume, is an important component of intensity together with velocity. In the case of slow-moving deep-seated landslides, the expected magnitude is the prevalent parameter for defining intensity when assessed as a spatially distributed variable in a given area. In particular, the frequency–volume statistics of past landslides may be used to understand and predict the magnitude of new landslides and reactivations. In this paper we study the spatial properties of volume frequency distributions in the Arno river basin (Central Italy, about 9100km2). The overall landslide inventory taken into account (around 27,500 events) shows a power-law scaling of volumes for values greater than a cutoff value of about 2×104m3. We explore the variability of the power-law exponent in the geographic space by setting up local subsets of the inventory based on neighbourhoods with radii between 5 and 50km. We found that the power-law exponent α varies according to geographic position and that the exponent itself can be treated as a random space variable with autocorrelation properties both at local and regional scale. We use this finding to devise a simple method to map the magnitude frequency distribution in space and to create maps of exceeding probability of landslide volume for risk analysis. We also study the causes of spatial variation of α by analysing the dependence of power-law properties on geological and geomorphological factors, and we find that structural settings and valley density exert a strong influence on mass movement dimensions

    landslide susceptibility of the prato pistoia lucca provinces tuscany italy

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    ABSTRACTWe mapped landslide susceptibility in the provinces of Lucca, Pistoia and Prato (central Italy), a 3103 km2 territory that approximately corresponds to the portion of Tuscany principally affected by landslides. We used a methodology based on a treebagger random forest. The input parameters used for the susceptibility assessment are curvature, flow accumulation, topographic wetness index, elevation, profile curvature, planar curvature, slope gradient, aspect, land use and lithology. The map was validated providing satisfactory results (AUC = 0.84). The map classifies the study area into four susceptibility classes that identify areas with different probabilities of being affected by landslides. The Main Map represents a useful instrument to assist land planning, development of mitigation measures and landslide risk management. Moreover, it could be used in further research addressing quantitative hazard and risk assessment

    Quantum sensors for dynamical tracking of chemical processes

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    Quantum photonics has demonstrated its potential for enhanced sensing. Current sources of quantum light states tailored to measuring, allow to monitor phenomena evolving on time scales of the order of the second. These are characteristic of product accumulation in chemical reactions of technologically interest, in particular those involving chiral compounds. Here we adopt a quantum multiparameter approach to investigate the dynamic process of sucrose acid hydrolysis as a test bed for such applications. The estimation is made robust by monitoring different parameters at once

    Apresentação incomum de hepatite induzida por Epstein-Barr Virus em criança de 15 meses de idade

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    Objective: We report an atypical case of hepatitis in an infant that could be helpful to physicians of various specialties, as it demonstrates an atypical clinical and laboratorial manifestation of a disease not so common at that age and that could have gone undiagnosed. Case Description: A 15-month-old female, immunocompetent patient was referred to the hospital with a 3-day history of fever, vomiting, and diarrhea. The patient presented with alternation between sleepiness and irritation associated with rapid increase in serum liver enzymes levels, but no jaundice. Neurologic evaluation showed no meningeal signs and no encephalic morphological abnormalities were observed in a cranial CT scan. Treatment consisted of symptomatic medication and daily evaluation for signs of hepatic encephalopa- thy or bleeding. A serological panel showed negative IgM but positive IgG reactivity against Cytomega- lovirus (CMV) and IgM and IgG negative immunoreactivity against HAV. She was not tested for Hepatits B (HBV) or Hepatits C (HCV). Positive immunoreactivity against the Epstein-Barr virus capsid antigen (EBV VCA) IgM and negative reactivity against IgG, indicated a diagnosis of EBV-induced acute hepatitis. The patient was discharged asymptomatic after 11 days, with decreasing serum liver enzymes levels. A 15-day follow up evidenced complete remission of symptoms and normalized laboratory tests. Comments: Hepatic involvement in infections by Epstein-Barr Virus is common, presenting with moderate and transient increase in liver enzymes. It can go undetected and resolve spontaneously, while clinical manifestations of hepatitis are infrequent. In this report, we present an unusual case of a pediatric patient with hepatitis induced by EBV infection, along with a review of the literature. According to our search, no other EBV-induced hepatitis case reports have been published involving an immunocompetent patient under 2 years of ageObjetivo: Este relato de uma hepatite em um paciente pediátrico pode trazer benefícios para médicos de diversas especialidades, pois ele demonstra um quadro clínico e laboratorial atípicos de uma doença não tão comum nessa faixa etária e que poderia não ter sido diagnosticada. Descrição do Caso: Uma paciente, de 15 meses de idade, foi referenciada ao hospital com história de 3 dias de febre, vômitos e diarréia. A paciente apresentava alternância entre sonolência e irritação associada com rápida elevação das enzimas hepáticas, mas sem icterícia. Ao exame neurológico não foram evidenciados sinais meníngeos e a tomografia computadorizada de crânio não apresentou altera- ções. O tratamento consistiu em medicação sintomática junto à avaliação diária dos sinais de encefalopatia hepática ou sangramentos. O painel sorológico foi de IgM negativo e IgG positivo para Citomegalovirus (CMV) e IgM e IgG negativos para Anti-HAV. Em contraste, encontrou-se no soro IgM Imunorreativa contra o antígeno do capsídeo do vírus Epstein-Barr (EBV VCA), o que confirmou um diagnóstico de hepatite pelo EBV. A paciente recebeu alta hospitalar assintomática após 11 dias de internação, com declínio dos valores séricos das transaminases. Um acompanhamento após 15 dias da alta evidenciou completa remissão dos sintomas. Comentários: O envolvimento do fígado com infecções pelo vírus Epstein-Barr é comum, apresentando elevações moderadas e transitórias das enzimas hepáticas. Ela pode não ser detectada e ser autolimitada, enquanto manifestações hepáticas são infrequentes. Nesse relato de caso, é apresentado um quadro pediátrico atípico de um paciente que desenvolveu hepatite induzido pela infecção por EBV, além de uma revisão na literatura. De acordo com nossa busca, nenhum outro caso de hepatite induzida por EBV foi publicado envolvendo um paciente imunocompetente com idade inferior a 2 ano

    Oxidized Palladium Supported on Ceria Nanorods for Catalytic Aerobic Oxidation of Benzyl Alcohol to Benzaldehyde in Protic Solvents

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    In the present study, the catalytic activity of palladium oxide (PdOx) supported on ceria nanorods (CeO2-NR) for aerobic selective oxidation of benzyl alcohol (BnOH) to benzaldehyde (PhCHO) was evaluated. The CeO2-NR was synthesized hydrothermally and the Pd(NO3)2 was deposited by a wet impregnation method, followed by calcination to acquire PdOx/CeO2-NR. The catalysts were characterized by X-ray diffraction (XRD), temperature programmed reduction (TPR), transmission electron microscopy (TEM), Brunauer–Emmet–Teller (BET) surface area analysis, and X-ray photoelectron spectroscopy (XPS). In addition, the TPR-reduced PdOx/CeO2-NR (PdOx/CeO2-NR-Red) was studied by XRD, BET, and XPS. Characterizations showed the formation of CeO2-NR with (111) exposed plane and relatively high BET surface area. PdOx (x > 1) was detected to be the major oxide species on the PdOx/CeO2-NR. The activities of the catalysts in BnOH oxidation were evaluated using air, as an environmentally friendly oxidant, and various solvents. Effects of temperature and palladium oxidation state were investigated. The PdOx/CeO2-NR showed remarkable activity when protic solvents were utilized. The best result was achieved using PdOx/CeO2-NR and boiling ethanol as solvent, leading to 93% BnOH conversion and 96% selectivity toward PhCHO. A mechanistic hypothesis for BnOH oxidation with PdOx/CeO2-NR in ethanol is presente

    Predictive Role of Serum Thyroglobulin after Surgery and before Radioactive Iodine Therapy in Patients with Thyroid Carcinoma

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    Introduction: Thyroidectomy followed by radioactive iodine therapy (RAI) is the treatment of choice for differentiated thyroid carcinoma (DTC). Serum thyroglobulin (Tg) measurement has proved to be useful for predicting persistent and/or recurrent disease during follow-up of DTC patients. In our study, we evaluated the risk of disease recurrence in patients with papillary thyroid carcinoma (PTC), who were treated with thyroidectomy and RAI, by measuring serum Tg at different time-points: at least 40 days after surgery, in euthyroidism with TSH < 1.5 and usually 30 days before RAI (Tg−30), on the day of RAI (Tg0), and seven days after RAI (Tg+7). Methods: One hundred and twenty-nine patients with PTC were enrolled in this retrospective study. All patients were treated with 131I for thyroid remnant ablation. Disease relapse (nodal disease or distant disease) during at least 36 months follow-up was evaluated by serum measurements of Tg, TSH, AbTg at different time points and by imaging techniques (neck ultrasonography, 131I-whole body scan (WBS) after Thyrogen® stimulation). Typically, patients were assessed at 3, 6, 12, 18, 24, and 36 months after RAI. We classified patients in five groups: (i) those who developed nodal disease (ND), (ii) those who developed distant disease (DD), (iii) those with biochemical indeterminate response and minimal residual thyroid tissue (R), (iv) those with no evidence of structural or biochemical disease + intermediate ATA risk (NED-I), and (v) those with no evidence of structural or biochemical disease + low ATA risk (NED-L). ROC curves for Tg were generated to find potential discriminating cutoffs of Tg values in all patients’ groups. Results: A total of 15 out of 129 patients (11.63%) developed nodal disease and 5 (3.88%) distant metastases, during the follow-up. We found that Tg−30 (with suppressed TSH) has the same sensitivity and specificity than Tg0 (with stimulated TSH), and it is slightly better than Tg+7, which can be influenced by the size of the residual thyroid tissue. Conclusion: Serum Tg−30 value, measured in euthyroidism 30 days before RAI, is a reliable prognostic factor to predict future nodal or distant disease, thus allowing to plan the most appropriate therapy and follow-up
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