194 research outputs found

    On the peritidal cycles and their diagenetic evolution in the Lower Jurassic carbonates of the Calcare Massiccio Formation (Central Apennines)

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    This paper shows the environmental changes and high-frequency cyclicity recorded by Lower Jurassic shallow- water carbonates known as the Calcare Massiccio Formation which crop out in the central Apennines of Italy. Three types of sedimentary cycle bounded by subaerial erosion have been recognized: Type I consists of a shallowing upward cycle with oncoidal floatstones to rudstones passing gradationally up into peloidal packstone alternating with cryptoalgal laminites and often bounded by desiccation cracks and pisolitic-peloidal wackestones indicating a period of subaerial exposure. Type II shows a symmetrical trend in terms of facies arrangement with peloidal packstones and cryptoalgal laminites present both at the base and in the upper portion of the cycle, separated by oncoidal floatstones to rudstones. Type III displays a shallowing upward trend with an initial erosion surface overlain by oncoidal floatstones to rudstones that, in turn, are capped by pisolitic-peloidal wackestones and desiccation sheet cracks. Sheet cracks at the top of cycles formed during the initial phase of subaerial exposure were successively enlarged by dissolution during prolonged subaerial exposure. The following sea-level fall produced dissolution cavities in subtidal facies, while the successive sea-level rise resulted in the precipitation of marine cements in dissolution cavities. Spectral analysis revealed six peaks, five of which are consistent with orbital cycles. While a tectonic control cannot be disregarded, the main signal recorded by the sedimentary succession points toward a main control related to orbital forcing. High frequency sea-level fluctuations also controlled diagenetic processes

    Characterization of power transistors as high dose dosimeters

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    A bipolar transistor, previously investigated as a possible radiation dosimeter and tested under industrial irradiation conditions in high-activity gamma and high-energy, high-power electron beam facilities has been subjected to stability test in order to understand its behaviour and help to improve its performances. Charge carrier lifetime was measured for several sets of transistors which were then irradiated with various doses (3-60 kGy): seven sets with Co-60 gamma rays and eight with a 10MeV electron beam. After irradiation all the transistors were measured and each set was divided into three groups: one group was left untreated, the second group was heated at 100 degrees C for 30 minutes and the third group was heated at 150 degrees C for 30 minutes, for testing the stability of the lifetime. Our data showed that heat treatment quite successfully eliminates post-irradiation changes in the response. Response measurements of the irradiated transistors, heat-treated and untreated, were carried out at room temperature over several weeks after irradiation to establish post-irradiation stability and assess if these transistors could be used for recording dose history. Calibration curves in the range 3-60 kGy for the thermally treated and untreated devices are presented. Dependence of the response of the transistors on the temperature of the measurements in the range 20-50 degrees C is reported

    Danon disease in a Sardinian family: different aspects of the same mutation-a case report

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    Background Danon disease (DD) is a rare X-linked disorder due to mutations in the lysosome-associated membrane protein 2 gene. It is characterized by a clinical triad of hypertrophic cardiomyopathy, skeletal myopathy, and a variable degree of intellectual disability. Case summary In this case series, we describe a mother and her son affected by DD, highlighting consistent clinical severity despite the expected variability related to gender. The mother (Case 1) presented isolated cardiac involvement, with an arrhythmogenic phenotype that evolved into severe heart failure requiring heart transplantation (HT). Danon disease was diagnosed 1 year after this event. Her son (Case 2) showed an earlier age onset of symptoms with complete atrioventricular block and fast progression of cardiac disease. Diagnosis was established 2 years after clinical presentation. He is currently listed for HT. Discussion In both of our patients, diagnostic delay was extremely long and could have been avoided by emphasizing the relevant clinical red flags. Patients affected by DD may present clinical heterogeneity in terms of natural history, age of onset, and cardiac and extracardiac involvement, even in the same family. Early diagnosis that phenotypic sex differences may impact is a crucial factor in managing patients with DD. Considering the rapid progression of cardiac disease and the poor prognosis, early diagnosis is important and close surveillance should be mandatory during follow-up

    The Detection Rate of Late Gadolinium Enhancement in Takotsubo Syndrome: A Systematic Review and Meta-Analysis

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    Absence of late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) is commonly used to distinguish takotsubo syndrome (TTS) from other myocardial diseases. However, case series have reported the presence of LGE in TTS. The present study aimed to summarize the evidence on the frequency of LGE in TTS and identify potential variables that may influence the detection of LGE. Electronic databases were systematically searched for studies reporting LGE frequency in TTS patients. The overall frequency was estimated using the inverse variance method and a random-effect model for single proportion. Factors influencing LGE detection were analyzed. Among 490 studies screened, 21 were included (703 patients, 90% female). The estimated overall frequency of LGE was 22.4% (95% CI 8.7-39.6%). Among TTS patients who underwent CMR within three days of symptom occurrence, the frequency of LGE was 40.7% (95% CI 18.8-64.5%), significantly higher than among those who performed CMR after three days (3.9%, p<0.010). The sensitivity threshold used in the imaging protocols had a statistically significant impact on the frequency of LGE detection (p=0.030). Ten studies performed a follow-up CMR after at least three months, reporting a frequency of LGE of 1.7 % (95% CI 0.0-8.9%). In conclusion, published studies report the presence of LGE in TTS at presentation among a significant proportion of patients. However, its detection is strongly influenced by the duration between symptom onset and CMR acquisition, and by the sensitivity threshold used for the imaging protocol. LGE is rarely present at follow-up

    Associazione Nazionale Medici Cardiologi Ospedalieri (ANMCO) scientific statement on the simplification of the drug regimen for secondary cardiovascular prevention

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    : The issue of suboptimal drug regimen adherence in secondary cardiovascular prevention presents a significant barrier to improving patient outcomes. To address this, the utilization of drug combinations, specifically single pill combinations (SPCs) and polypills, was proposed as a strategy to simplify treatment regimens. This approach aims to enhance treatment accessibility, affordability, and adherence, thereby reducing healthcare costs and improving patient health. The document is an Associazione Nazionale Medici Cardiologi Ospedalieri (ANMCO) scientific statement on simplifying drug regimens for secondary cardiovascular prevention. It discusses the underuse of treatments despite available, effective, and accessible options, highlighting a significant gap in secondary prevention across different socio-economic statuses and countries. The statement explores barriers to implementing evidence-based treatments, including patient, healthcare provider, and system-related challenges. The paper also reviews international guidelines, the role of SPCs and polypills in clinical practice, and their economic impact, advocating for their use in secondary prevention to improve patient outcomes and adherence

    Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

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    Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening
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