208 research outputs found
Cosmic-ray propagation with DRAGON2: II. Nuclear interactions with the interstellar gas
Understanding the isotopic composition of cosmic rays (CRs) observed near
Earth represents a milestone towards the identification of their origin. Local
fluxes contain all the known stable and long-lived isotopes, reflecting the
complex history of primaries and secondaries as they traverse the interstellar
medium. For that reason, a numerical code which aims at describing the CR
transport in the Galaxy must unavoidably rely on accurate modelling of the
production of secondary particles. In this work we provide a detailed
description of the nuclear cross sections and decay network as implemented in
the forthcoming release of the galactic propagation code DRAGON2. We present
the secondary production models implemented in the code and we apply the
different prescriptions to compute quantities of interest to interpret local CR
fluxes (e.g., nuclear fragmentation timescales, secondary and tertiary source
terms). In particular, we develop a nuclear secondary production model aimed at
accurately computing the light secondary fluxes (namely: Li, Be, B) above 1
GeV/n. This result is achieved by fitting existing empirical or semi-empirical
formalisms to a large sample of measurements in the energy range 100 MeV/n to
100 GeV/n and by considering the contribution of the most relevant decaying
isotopes up to iron. Concerning secondary antiparticles (positrons and
antiprotons), we describe a collection of models taken from the literature, and
provide a detailed quantitative comparison.Comment: 22 pages, 12 figure
Mechanism of Inhibition of the GluA2 AMPA Receptor Channel Opening by 2,3-Benzodiazepine Derivatives
Some DLV Applications for Knowledge Management
Abstract. Even if the industrial exploitation of the DLV system has started very recently, DLV already has a history of applications on the industrial level. The most valuable applications from a commercial viewpoint are those in the area of Knowledge Management. They have been realized by the company EXEURA s.r.l. -a spin-off company of the University of Calabria having a branch also in Chicago -with the support of the DLVSYSTEM s.r.l.. DLV applications in this area have not been realized directly, but through some specializations of DLV into Knowledge Management (KM) products for Text Classification, Information Extraction, and Ontology Representation and Reasoning. After briefly describing these KM products, we report on their recently-released successful applications
Microwave-Assisted Synthesis of 2-Methyl-1H-indole-3-carboxylate Derivatives via Pd-Catalyzed Heterocyclization
Indole moiety is well-known as a superlative framework in many natural products and synthetic pharmaceuticals. Herein, we report an efficient procedure to synthesize a series of functionalized 2-methyl-1H-indole-3-carboxylate derivatives from commercially available anilines properly functionalized by different electron-withdrawing and -donating groups through a palladiumcatalyzed intramolecular oxidative coupling. The conversion of a variety of enamines into the relevant indole was optimized by exposing the neat mixture of reactants to microwave irradiation, obtaining the desired products in excellent yields and high regioselectivity. The synthesized compounds were confirmed by 1H and 13C spectroscopic means as well as by high-resolution mass spectrometry
The prevalence of peripheral and central hearing impairment and its relation to cognition in older adults.
Age-related hearing loss (ARHL) and dementia are two highly prevalent conditions in the adult population. Recent studies have suggested that hearing loss is independently associated with poorer cognitive functioning. The aim of this study was to evaluate the prevalence of ARHL and cognitive impairment in a large sample of subjects older than 65 years and to correlate hearing function with cognitive function. A total of 488 subjects older than 65 years (mean age 72.8 years) participating in the Great Age Study underwent a complete audiological, neurological and neuropsychological evaluation as part of a multidisciplinary assessment. The prevalence of a hearing loss greater than 25 dB HL was 64.1%, of Central Auditory Processing Disorder (CAPD) was 14.3 and 25.3% of the subjects reported a hearing handicap as reported on the Hearing Handicap Inventory for the Elderly Screening Version questionnaire. Multiple logistic regression analysis corrected for gender, age and education duration showed that mild cognitive impairment (MCI) was significantly associated with hearing impairment (CAPD and hearing threshold; odds ratio 1.6, p = 0.05) and that Alzheimer's disease (AD) was significantly associated with CAPD (odds ratio 4.2, p = 0.05). Given that up to 80% of patients affected by MCI convert to AD, adding auditory tests to a screening cognitive battery might have value in the early diagnosis of cognitive decline
Imaging Evaluation of Pulmonary and Non-Ischaemic Cardiovascular Manifestations of COVID-19
Coronavirus Disease 2019 (COVID-19) has been a pandemic challenge for the last year. Cardiovascular disease is the most described comorbidity in COVID-19 patients, and it is related to the disease severity and progression. COVID-19 induces direct damage on cardiovascular system, leading to arrhythmias and myocarditis, and indirect damage due to endothelial dysfunction and systemic inflammation with a high inflammatory burden. Indirect damage leads to myocarditis, coagulation abnormalities and venous thromboembolism, Takotsubo cardiomyopathy, Kawasaki-like disease and multisystem inflammatory syndrome in children. Imaging can support the management, assessment and prognostic evaluation of these patients. Ultrasound is the most reliable and easy to use in emergency setting and in the ICU as a first approach. The focused approach is useful in management of these patients due its ability to obtain quick and focused results. This tool is useful to evaluate cardiovascular disease and its interplay with lungs. However, a detailed echocardiography evaluation is necessary in a complete assessment of cardiovascular involvement. Computerized tomography is highly sensitive, but it might not always be available. Cardiovascular magnetic resonance and nuclear imaging may be helpful to evaluate COVID-19-related myocardial injury, but further studies are needed. This review deals with different modalities of imaging evaluation in the management of cardiovascular non-ischaemic manifestations of COVID-19, comparing their use in emergency and in intensive care. View Full-Tex
A markov model to evaluate hospital readmission
<p>Abstract</p> <p>Background</p> <p>The analysis of non-fatal recurring events is frequently found in studies on chronic-degenerative diseases. The aim of this paper is to estimate the probability of readmission of patients with Chronic Obstructive Pulmonary Disease (COPD) or with Respiratory Failure (RF).</p> <p>Methods</p> <p>The Repeated hospital admissions of a patient are considered as a Markov Chain. The transitions between the states are estimated using the Nelson-Aalen estimator. The analysis was carried out using the Puglia Region hospital patient discharge database for the years 1998–2005. Patients were selected on the basis of first admission between 01/01/2001 and 31/12/2005 with ICD-9-CM code of COPD or RF as principal and/or secondary diagnosis. For those selected two possible transitions were considered in the case they had the second and third admission with an ICD-9-CM code of COPD or RF as principal diagnosis.</p> <p>Results</p> <p>The probability of readmission is increased in patients with a diagnosis of RF (OR = 1.618 in the first transition and 1.279 in the second) and also in those with a diagnosis of COPD or RF as the principal diagnosis at first admission (OR = 1.615 in the first transition and 1.193 in the second). The clinical gravity and the ward from which they were discharged did not significantly influence the probability of readmission.</p> <p>Conclusion</p> <p>The time to readmission depends on the gravity of the pathology at onset. In patients with a grave clinical picture, either COPD or Respiratory Failure, when treated and controlled after the first admission, they become minor problems and they are indicated among secondary diagnoses in any further admission.</p
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