0000000001085465
AUTHOR
Maria Valenti
showing 8 related works from this author
Choice and Outcomes of Rate Control versus Rhythm Control in Elderly Patients with Atrial Fibrillation: A Report from the REPOSI Study
2018
Background: Among rate-control or rhythm-control strategies, there is conflicting evidence as to which is the best management approach for non-valvular atrial fibrillation (AF) in elderly patients. Design: We performed an ancillary analysis from the ‘Registro Politerapie SIMI’ study, enrolling elderly inpatients from internal medicine and geriatric wards. Methods: We considered patients enrolled from 2008 to 2014 with an AF diagnosis at admission, treated with a rate-control-only or rhythm-control-only strategy. Results: Among 1114 patients, 241 (21.6%) were managed with observation only and 122 (11%) were managed with both the rate- and rhythm-control approaches. Of the remaining 751 patie…
Dynamic Control of Static Converters for the Transition from Grid-on to Grid-off Operation of AC/DC Microgrids
2022
In this paper, specific control logics defined for generators, controllable loads and electric energy storage systems are illustrated in order to improve the reliability of AC/DC hybrid microgrids in their grid-off operation following failure events such as short-circuits, line breaks, sudden disconnections of generating units or loads, etc. After defining specific control schemes, these were modelled in a digital environment and finally tested with dynamic simulations. Finally, the paper highlights the role of virtual synchronous machine control for the self-healing capacity of islanded hybrid microgrids.
Frequency stability in microgrid: control strategies and analysis of BESS aging effects
2016
In order to ensure a thorough analysis, all components placed in a microgrid would have to be considered to guarantee an effective energy management. To this aim, various algorithms are used both to preserve and restore power systems after significant disturbances. However, these models frequently do not evaluate components performance decline with the age and, consequently, they don't consider actual values during microgrid analysis, potentially affecting obtained results. In particular, evaluating energy storage systems aging and their effects has rarely been addressed in prior works. The present article proposes a model to maintain power system/microgrid stability after disturbances usin…
Low-grade fever: how to distinguish organic from non-organic forms.
2010
Summary Background and aim: Low-grade fever (LGF) is defined as a body temperature between 37.5 and 38.3 °C, which is below the classical value reported for fever of unknown origin (FUO). We attempted to characterise its epidemiology, aetiology and clinical aspects to improve the methodological approach to diagnosis. Design and Methods: We reviewed and evaluated a survey of patients with LGF, followed as outpatients of our Department, a tertiary referral centre from 1997 to 2008. The same classifications were applied for classical FUO, and in the patients diagnosed with LGF, we also investigated for habitual hyperthermia (HH). Results: Seventy-three patients were selected and divided int…
Independent energetic grids for a smart island: Model and design of a microgrid for a small Italian island
2016
Unlike many Italian peninsular areas, which are increasingly turning to a diverse supply of renewable resources to generate electricity, Italian not-interconnected small islands continue to rely on oil for their electricity and other energy needs (e.g. transports). Small-scale electricity systems, that are not connected to a larger electricity grid, are usually more expensive. The present paper proposes the functional design of an innovative Smart Grid which allows changing an Italian small not-interconnected island, Pantelleria, into a smart island, towards a more sustainable energy model. In detail, a techno-economic feasibility study is performed in order to design a Smart Grid at Pantel…
DC Grids for Supporting AC Power System during Failure Events: Experimental Testing of a Urban Case Study
2022
AC power systems and their devices can be subjected to different failure events due to thermal, environmental, and aging phenomena. In this context, DC grids intervention could mitigate customers black-out by adequately controlling their internal resources (renewable generators and storage systems). In this paper, failure events concerning HV/MV transformer are considered. Possible actions to support the AC grid to avoid interruption in load areas are analyzed and experimentally validated. Tests campaigns are carried out taking advantage of a research nanogrid infrastructure available at ENEA Centre of Portici. It consists of indoor equipment able to emulate actual generation, load and stor…
Adherence to antithrombotic therapy guidelines improves mortality among elderly patients with atrial fibrillation: insights from the REPOSI study
2016
Background: Atrial fibrillation (AF) is associated with a substantial risk of thromboembolism and mortality, significantly reduced by oral anticoagulation. Adherence to guidelines may lower the risks for both all cause and cardiovascular (CV) deaths. Methods: Our objective was to evaluate if antithrombotic prophylaxis according to the 2012 European Society of Cardiology (ESC) guidelines is associated to a lower rate of adverse outcomes. Data were obtained from REPOSI; a prospective observational study enrolling inpatients aged ≥65 years. Patients enrolled in 2012 and 2014 discharged with an AF diagnosis were analysed. Results: Among 2535 patients, 558 (22.0 %) were discharged with a diagnos…
Heart failure and chronic kidney disease in a registry of internal medicine wards
2014
Background: The aim of the present study was to evaluate the association between heart failure (HF) and chronic kidney disease (CKD) in tertiary care centers using the clinical records of patients enrolled in internal medicine departments.Patients and methods: We used the clinical records of 1380 elderly patients to identify patients with a history of HF and CKD using admission ICD codes and glomerular filtration rate (GFR) formulas. Magnitude and strength of such associations were investigated by univariable and multivariable analysis.Results: Of the 1380 patients enrolled, 27.9% had HF (age 80 ± 7, BMI 27 ± 6 kg/m2) and 17.4% CKD (age 81 ± 7, BMI 26.8 ± 6 kg/m2). Both groups were signific…