381 research outputs found
Calibration of the ASTRI SST-2M Prototype using Muon Ring Images
The study of ring images generated from high-energy muons is a very useful
tool for the performance monitoring and calibration of any Imaging Atmosphere
Cherenkov Telescope. Isolated muons travelling towards the telescope light
collector system produce characteristic Cherenkov ring images in the focal
plane camera. Since the geometry and the distribution of light deployed onto
the camera can be easily reconstructed analytically for a muon of given energy
and direction, muon rings are a powerful tool for monitoring the behaviour of
crucial properties of an imaging telescope such as the point-spread-function
and the overall light collection efficiency. In this contribution we present
the possibility of using the analysis of muon ring images as calibrator for the
ASTRI SST-2M prototype point spread function.Comment: In Proceedings of the 33rd International Cosmic Ray Conference
(ICRC2013), Rio de Janeiro (Brazil). All ASTRI contributions at
arXiv:1307.463
A structure-function analysis in patients with prekallikrein deficiency.
To investigate the structure-function relation in prekallikrein (PK) deficiency. PK is one of the proteins of the contact phase of blood coagulation which at the present time is the object of a revival of interest.All patients with PK deficiency who had been investigated by molecular biology techniques are the object of the present investigation. Details of patients were obtained from personal files and a time-unlimited PubMed search. Only cases with a molecular-biology-based diagnosis were included.Twelve families were included. The total number of missense mutation was 10, together with 3 stop codons and 2 insertions. These mutations involved mainly exons 11 and 14. There were eight proved homozygotes and three compound heterozygotes. In one instance, homozygosity was probable but not proved. In nine cases, the defect was Type I, whereas it was Type II in the remaining three. No bleeding manifestations were present in 11 of the 12 probands. One proband had epistaxis, but she had hypertension. Altogether, four patients had hypertension and one of them had also two myocardial infarctions.Despite the paucity of cases, it was established that the majority of mutations involved the catalytic domain. It is auspicable that future reports of patients with this disorder should include molecular studies. This would certainly contribute to the understanding of the contact phase of blood coagulation
Congenital prothrombin defects: they are not only associated with bleeding but also with thrombosis: a new classification is needed.
Congenital prothrombin deficiency is one of the rarest clotting disorders. It is commonly subdivided in Type I defects or cases of 'true' prothrombin deficiency characterized by a concomitant decrease in FII activity and antigen and in Type II or dysprothrombinemias, in which FII activity is low but FII antigen is normal or near normal. A bleeding tendency, often a severe one, is the hallmark of the two-defects even though the bleeding is usually less severe in the Type 2 defects or dysprothrombinemias.An extensive search of published cases of prothrombin deficiency was carried out in Pubmed and Scopus. The search started in 2012, after the publication of the first family with dysprothrombinemia and venous thrombosis. A few additional families were found.Recent studies have demonstrated that the Type 2 defects are heterogeneous. Several heterozygous mutations involving the Arg596 residue of exon 14 have been demonstrated not be associated with a bleeding tendency but, surprisingly, with venous thromboses. Mutations in close areas of prothrombin have failed to show the same pattern.These observations have required a reclassification of prothrombin defects. To the Type I and Type II defects, a Type III has to be added characterized by the absence of bleeding and the presence of venous thrombosis. It is not clear yet if this special variant of Type II defect is limited to the Arg596 mutations or if other residues may be involved
Bleeding manifestations in heterozygotes with congenital FVII deficiency: a comparison with unaffected family members during a long observation period.
To determine whether heterozygotes with FVII deficiency have a bleeding tendency or not.Eighty-four patients (OK) heterozygous for FVII deficiency, at the onset of the study, were paired with unaffected family members and followed for a long period of time (mean 22.6 years) for the occurrence of bleeding. Diagnosis of heterozygosis had to be based on family studies, clotting, immunological assays and genetic analysis.The mean FVII activity level was 0.51 IU/dl (range 35-65) and 94 IU/dl (range 88-118) in the heterozygotes and in the normal counterparts, respectively. Documented bleeding manifestations occurred in eight heterozygotes and in seven normal subjects. Statistical analysis of the difference was not significant. Bleeding manifestations were easy bruising, bleeding after tooth extractions, menorrhagia, epistaxis with no difference among the two groups. There was no strict correlation between bleeding and FVII activity levels.The study indicates that heterozygotes for FVII deficiency show rare bleeding manifestations which are also present in the unaffected family members with normal FVII levels. This indicates that Factor VII activity levels played no role in the occurrence of the bleeding symptoms. Furthermore, FVII levels of around 0.40 IU/dl are capable of assuring a normal hemostasis
Comparison on Well-Being, Engagement and Perceived School Climate in Secondary School Students with Learning Difficulties and Specific Learning Disorders: An Exploratory Study
none6noopenLombardi, Elisabetta; Traficante, Daniela; Bettoni, Roberta; Offredi, Ilaria; Vernice, Mirta; Sarti, DanielaLombardi, Elisabetta; Traficante, Daniela; Bettoni, Roberta; Offredi, Ilaria; Vernice, Mirta; Sarti, Daniel
Blood Pressure and Metabolic Changes After 3-Month CPAP Therapy in a Very Elderly Obese with Severe Obstructive Sleep Apnea: A Case Report and Review of the Literature
none7noAge is one of the main risk factor for the presence of obstructive sleep apnea (OSA). This syndrome is associated with hypertension, cardiovascular disease, cognitive impairment and metabolic abnormalities, such as type 2 diabetes. Continuous positive airway pressure (CPAP) represents the gold standard therapy, but its benefit is still to be determined in very elderly. We report the blood pressure and metabolic changes in a very elderly obese with severe OSA after 3-month CPAP therapy. We have evaluated a very elderly obese male affected by severe symptomatic OSA, poor controlled nocturnal hypertension and insulin resistance. After 3-month CPAP therapy, without any changes in drug therapy, we observed a normalization of circadian blood pressure (BP) pattern, an improved insulin sensitivity, together with a reduced resting energy expenditure, despite no significant change in weight. This case report shows the benefits of OSA treatment with CPAP, not only on BP profile, but also on metabolic parameters in a very elderly, a particular type of patient in which scientific evidence is still scant. Further studies are needed to better investigate the relationship between OSA, CPAP therapy and energy expenditure not only in adults but also in elderly patients.Spannella, Francesco; Giulietti, Federico; Di Pentima, Chiara; Lombardi, Francesca Elena; Borioni, Elisabetta; Sarzani, RiccardoSpannella, Francesco; Giulietti, Federico; Di Pentima, Chiara; Lombardi, Francesca Elena; Borioni, Elisabetta; Sarzani, Riccardo; Spannella, Francesc
2078 High prevalence of cardiac hypertophy without detectable signs of fibrosis in patients with untreated active acromegaly: an in-vivo study using magnetic resonance imaging and integrated backscatter analysis
Introduction Left ventricular (LV) hypertrophy and myocardial fibrosis are considered the main pathological features of acromegalic cardiomyopathy. Cardiovascolar Magnetic Resonance (CMR) allows to detect myocardial gross fibrosis using the delayed enhancement (DE) technique. Myocardial echointensity as derived by integrated backscatter (IBS) echocardiographic analysis is considered an index of myocardial collagen content
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