Structural and elastic behavior of Fe₅₀Al₅₀ nanocrystalline alloys

Pure iron and aluminum powders were mixed in the equiatomic ratio and mechanically alloyed in a high-energy ball mill for different times. Structure refinement of x-ray powder diffraction data was performed to study the structural transformations induced by mechanical and subsequent thermal annealing treatments. The mechanical alloying (MA) process induces a progressive dissolution of aluminum phase into the bcc iron phase. After 32 h of MA a single-phase Fe(Al) bcc extended solid solution, with lattice parameter a0 = 2.891 Å, average coherent domain size <D> ≈50 Å, and lattice strain 0.5%, was observed. The annealing of the specimens after MA up to 8 h favored the aluminum dissolution in a-iron and the precipitation of the Al5Fe2 phase, whereas a nanostructured B2 FeAl intermetallic compound was observed in the annealed samples which were previously milled for 8, 16, and 32 h. In the same specimens a minority cubic phase Fe3AlCX, anti-isomorphous with perovskite, derived from contamination of ethanol and introduced in the steel vial as a lubricant agent, was also observed. Anelasticity measurements have shown the occurrence of two main transient effects during the first thermal run. The first one occurring at 500 K in all mechanically alloyed specimens was attributed to thermally activated structural transformations, whereas the second at about 700 K was attributed to a magnetic order–disorder transition. During the second run of anelasticity measurements a relaxation peak P1 in the nanostructured B2 FeAl intermetallic compound, attributed to grain-boundary sliding mechanisms and with an activation energy of 1.8 ± 0.2 eV was observed. In specimens milled for 8–32 h a second small peak P2 at the low-temperature tail of the P1 peak was observed and tentatively attributed to a Zener-type relaxation

LACK OF AN ASSOCIATION BETWEEN INHERITED THROMBOPHILIC RISK FACTORS AND IDIOPATIC SUDDEN SENSORINEURAL HEARING LOSS IN ITALIAN PATIENTS

Objectives: We investigated the presence of congenital thrombophilic risk factors in a population of consecutive Italian patients affected by idiopathic sudden sensorineural hearing loss (SSNHL). Methods: We investigated 48 patients with idiopathic SSNHL for the presence of congenital thrombophilic risk factors. The factor V Leiden G1691A, the prothrombin G20210A allele, and methylenetetrahydrofolate reductase (MTHFR) C677T genotypes were investigated. Allele frequencies and genotype distribution of all factors found in patients were compared to those of 48 healthy subjects of the same ethnic background by Chi2 and odds-ratio analysis. Odds ratios and 95% confidence intervals were calculated for allele and genotype frequencies of all thrombophilia variants. Statistical significance was accepted with a p value of less than .05. We also performed the following blood tests: hemacytometric analysis including platelet count, prothrombin time, activated partial thromboplastin time, fibrinogen, erythrocyte sedimentation rate, C-reactive protein, protein S, protein C, antithrombin III, and activated protein C resistance. Results: In our series, we did not find an association between SSNHL and abnormal levels of antithrombin III, protein C, protein S, D-dimer, or fibrinogen; activated protein C resistance; or factor V G1691A, prothrombin G20210A, or MTHFR C677T mutations. Conclusions: At present, the few studies regarding genetic polymorphisms of congenital thrombophilic factors in SSNHL are not conclusive. According to our data, factor V G1691A, prothrombin G20210A, and MTHFR C677T variants should be not considered risk factors for SSNHL. Further large prospective studies are needed to provide currently lacking information and to improve our knowledge in the field before we recommend the determination of genetic polymorphism in SSNHL as routine practice

Coenzyme Q 10 and Cardiovascular Risk Factors in Idiopathic Sudden Sensorineural Hearing Loss Patients.

OBJECTIVES:: We investigated the association of idiopathic sudden sensorineural hearing loss (ISSNHL) with coenzyme Q (CoQ) and cardiovascular risk factors. STUDY DESIGN:: A prospective study. SETTING:: Hospital center. PATIENTS:: Thirty Italian patients with ISSNHL and 60 healthy Italian subjects. INTERVENTION:: Diagnostic. MAIN OUTCOME MEASURE:: Evaluation of serum CoQ levels and cardiovascular risk factors (total cholesterol, low-density lipoprotein [LDL], homocysteine [HCY]). The results were compared with variance analysis and Student's t test. Univariate and multivariate analysis were used to evaluate the association between ISSNHL and CoQ, total cholesterol, LDL, and HCY levels. RESULTS:: In our series, we found a significant association between ISSNHL and high total cholesterol (p < 0.05), high LDL (p = 0.021), and low CoQ (p < 0.05) levels. We did not find a significant association between ISSNHL and HCY levels. In the univariate analysis, low levels of CoQ, high levels of total cholesterol, and LDL were found to be significantly associated with ISSNHL. In the multivariate analysis, only high levels of total cholesterol and low levels of CoQ remained significantly associated with a high risk of sudden sensorineural hearing loss. CONCLUSION:: The studies regarding the role of cardiovascular risk factors in ISSNHL are not conclusive. This is the first report regarding the association of ISSNHL and low serum levels of the antioxidant CoQ. Further studies are needed toinvestigate the role of antioxidants, including CoQ, in ISSNHL

The Italian open data meteorological portal: MISTRAL

AbstractAt the national level, in Italy, observational and forecast data are collected by various public bodies and are often kept in various small, heterogeneous and non‐interoperable repositories, released under different licenses, thus limiting the usability for external users. In this context, MISTRAL (the Meteo Italian SupercompuTing PoRtAL) was launched as the first Italian meteorological open data portal, with the aim of promoting the reuse of meteorological data sets available at national level coverage. The MISTRAL portal provides (and archives) meteorological data from various observation networks, both public and private, and forecast data that are generated and post‐processed within the Consortium for Small‐scale Modeling‐Limited Area Model Italia (COSMO‐LAMI) agreement using high performance computing (HPC) facilities. Also incorporated is the Italy Flash Flood use case, implemented with the collaboration of European Centre for Medium‐Range Weather Forecasts (ECMWF), which exploits cutting edge advances in HPC‐based post‐processing of ensemble precipitation forecasts, for different model resolutions, and applies those to deliver novel blended‐resolution forecasts specifically for Italy. Finally, in addition to providing architectures for the acquisition and display of observational data, MISTRAL also delivers an interactive system for visualizing forecast data of different resolutions as superimposed multi‐layer maps

Glutathione s-transferase gene polymorphisms in italian patients with sudden sensorineural hearing loss.

HYPOTHESIS: To investigate the association between glutathione S-transferase (GST) gene polymorphisms and sudden sensorineural hearing loss (SSNHL) in a population of consecutive Italian patients. Assuming that reactive oxygen species formation may play a role in inner ear damage, we investigated whether profiles of GSTs antioxidant enzymes M1 and T1 genotypes may be associated with the risk of SSNHL. STUDY DESIGN: A prospective study in patients with SSNHL. PATIENTS AND METHODS: We investigated 80 Italian patients with SSNHL for the frequency of GSTT1 and GSTM1 polymorphisms. Genotype distribution of all factors found in patients were compared with those of 80 healthy control subjects of the same ethnic background using chi and odds-ratio analysis. Statistical significance was accepted at a level of p < 0.05. RESULTS: In our series, the frequencies of GSTM1 and GSTT1 null genotypes did not differ from those of the control subjects. CONCLUSION: The few studies regarding genetic polymorphisms of GSTs in SSNHL are not conclusive. Further studies are needed to investigate the role of antioxidants including GSTs in SSNHL and to provide the lacking information to improve our knowledge in the field before implementing the use of genetic polymorphism in the SSNHL medicine daily practice

Coeliac disease and hearing loss: Preliminary data on a new possible association.

Objective. Coeliac disease (CD), an autoimmune gluten-dependent enteropathy, can be associated with several extra-intestinal manifestations, including neurological disorders. At present, no data are available on the presence of hearing loss disorder in coeliac patients. The aim of the present study was to investigate the prevalence of hearing loss in coeliac patients compared with that in healthy controls. Material and methods. Twenty-four adult coeliac patients and 24 healthy subjects matched for gender, age, smoking and drinking habits were enrolled in the study. Among the coeliac patients, 6 were newly diagnosed and 18 patients were on a gluten-free diet for at least one year. Results. A hearing loss was found in 10 (47.1%) coeliac patients and 2 (9.1%) healthy controls. All CD patients with hearing loss presented a sensorineural hearing loss. The prevalence of hearing loss was significantly higher in coeliac patients than in healthy controls (p=0.01) but it was not significantly different between untreated (33.3%) and treated (44.4%) coeliac patients (p: NS). Conclusions. Despite the low number of subjects evaluated, the present study showed a higher prevalence of hearing loss in coeliac patients than in healthy controls, suggesting an association between CD and hearing loss. Immunological processes such as ear-specific and non-specific autoantibodies and vasculitis could be the basis of this association. Further longitudinal investigations on a larger sample size will be necessary to confirm the present data

Information management e ricerca scientifica : coordinate per documentare l'aerospazio. EINS-GEM e il servizio I2 plus : la ricerca su banche dati professionali e siti web [Information management nel settore aerospaziale. Atti del seminario svoltosi al CIRA - Centro Italiano Ricerche Aerospaziali. Capua, 22 marzo 2002]

This speech describes the nature and the functionalities of EINS-GEM, a service of EINS, European Information Network Services, that provides access to online information. The role of CINECA as technological centre of EINS is described as well as the main tools and services developed as I2 and I2 plus. In particular, I2 plus, oriented to the aerospace sector, allows contemporary access and research on several EINS-GEM databases and several web sites

Evoluzione strutturale e comportamento anelastico in leghe Fe50A150 e Fe75A125 nanocristalline

Dottorato di ricerca in fisica. 8. ciclo. A.a. 1994-95. Coordinatore G. Velo. Tutore L. FerrariConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal