Search results for "temi"
showing 10 items of 3194 documents
B cell activating factor (BAFF): Structure, functions, autoimmunity and clinical implications in Systemic Lupus Erythematosus (SLE)
2020
The B cell activating factor (BAFF), or B lymphocyte stimulator (BLyS), is a B cell survival factor which supports autoreactive B cells and prevents their deletion. BAFF expression is closely linked with autoimmunity and is enhanced by genetic alterations and viral infections. Furthermore, BAFF seems to be involved in adipogenesis, atherosclerosis, neuro-inflammatory processes and ischemia reperfusion (I/R) injury. BAFF is commonly overexpressed in Systemic Lupus Erythematosus (SLE) and strongly involved in the pathogenesis of the disease. The relationship between BAFF levels, disease activity and damage accrual in SLE is controversial, but growing evidence is emerging on its role in renal …
Imprenditorialità e convergenza tra produzione di pensiero e produzione di cose
2013
Le più qualificate sedi internazionali (ONU, 26 giugno 2013, Thematic Debate on Entrepreneurship for Development) ed europee (Commissione Europea, 9 gennaio 2013, Entrepreneurship 2020 Action Plan) concordano sulla necessità di accrescere il dinamismo imprenditoriale dei territori attraverso incisive e continuative azioni di educazione all’imprenditorialità dei giovani per il contrasto alla disoccupazione giovanile, alla povertà e per stimolare la crescita economica. Su questo tema la nostra regione è in forte ritardo e finora non ha mai avviato alcuna incisiva azione di sistema a supporto della educazione imprenditoriale dei giovani siciliani. Negli anni recenti della nostra storia, mai co…
Densità, complementarietà e qualità imprenditoriali per lo sviluppo locale
2017
Ricordo che da ragazzo provavo meraviglia quando, unendo con una matita i punti distribuiti su una pagina della Settimana Enigmistica, prendevano forma oggetti o animali. Da una distribuzione di punti, apparentemente casuale, man mano che procedevo unendo i punti, potevo intravedere il risultato finale. Il processo però era guidato da un sistema di numerazione e, infatti, a ogni punto era associato un numero. Unendo i punti seguendo la numerazione in ordine crescente, si vedeva emergere una forma che, a poco a poco, ero in grado di riconoscere. In questi anni mi sono reso conto che l’avvio di un’impresa, e anche la costruzione della nostra vita, è un percorso simile, così ci ha anche detto …
Energy efficiency analysis in Incremental Sheet Forming operations
2012
In literature, manufacturing processes have been studied with different approaches, but a lack in terms of their environmental impact and energy required is still present. The aim of this paper is to compute some energy efficiency analysis on a specific manufacturing process. More in detail, the attention will be focused on the Incremental Sheet Forming process in order to evaluate the required energy and how it changes for changing process conditions. Accordingly, a wide experimental investigation has been executed taking into account different process parameters (i.e. tool depth step, punch diameter, wall inclination angle and sheet thickness). The total energy consumption has been monito…
Valutare l'equità dei sistemi scolastici
2006
06038; Denis Meuret spiega le ragioni a sostegno di una misura del grado diquità dei sistemi scolastici e presenta i principi basilari per costruire un insieme d'indicatori dell'equità dell'istruzione e della scuola. Da questi principi è partito il GERESE (Il Gruppo Europeo di Ricerca sulla Equità dei Sistemi Educativi) per comporre l'insieme di 29 indicatori dell'equità. Meuret illustra al termine del suo saggio la structtura e l'organizzazione di questo insieme che è senza dubbio uno dei prodotti recenti più originali della ricerca sulla giustizia educativa
Impact of RES penetration on the frequency dynamics of the 500 kV vietnamese power system
2019
The increase of renewable energy sources (RES) typically operating as converter-interfaced generation (CIG) is progressively causing a significant change of power systems operation paradigm. The reduction of the overall available kinetic energy and the consequent impact on the dynamic response of the system is a relevant issue currently under investigation in academic and industrial scopes. The work analyzes the impact of different CIG penetration in the three areas of the 500 kV Vietnamese power system, North, Center and South. The system is modified substituting conventional synchronous generation with converter-interfaced generation. The models of power converters and corresponding contr…
Inertial response of isolated power networks with wind power plants
2019
The constant increase of power generation provided by renewable energy source (RES) power plants is causing a progressive reduction of the overall inertia of the power systems. Especially in the case of small, isolated power networks, the replacement of conventional generation plants with RES power plants can affect significantly the frequency response of the system. The critical low-inertia conditions can be improved by the introduction of specific additional controls to the RES power converters. These control schemes are known as “synthetic inertia” or “virtual inertia” controls. The paper analyzes the impact of a derivative-based inertial control on a small, isolated power system, with a…
System Stability of a Small Island's Network with Different Levels of Wind Power Penetration
2018
The reduction of the inertial response of the generation system has been one of the main obstacles to the penetration of high sharing of renewable energy sources in islanded systems. This issue can be solved thanks to innovative control that makes wind turbines able to provide the so-named synthetic inertia. The paper investigates some scenarios with different levels of wind power penetration in a small island whose grid is not supplied by the main grid, by the use of the software NEPLAN 360, simulating the wind power plants accordingly to the standard IEC 61400-27. The aim of the paper is to assess the maximum level of penetration in the island of wind generation, with traditional control …
An Analysis of the Intertial Response of Small Isolated Power Systems in Presence of Generation from Renewable Energy Sources
2018
Renewable Energy Sources are posing critical issues related to the mining of power systems stability, essentially due to a decrement of the inertial response during system's contingencies. As a consequence, to preserve the security and the reliability of the system, it is necessary to adopt new frequency adjustments mechanisms. This issue becomes particularly critical in isolated power systems, like those of small islands not supplied by the main grid, in the case of high shares of production from unpredictable renewabies such as photovoitaic and wind sources. In this framework, the present work deals with the analysis of the variation of the inertia time constant of a small island in vario…
Ovarian stimulation for ovulation induction and in vitro fertilization in patients with systemic lupus erythematosus and antiphospholipid syndrome.
2008
Objective To review the current evidence regarding the relationship between systemic lupus erythematosus (SLE) and antiphospholipid syndrome and female infertility, as well as the risks associated with ovarian stimulation for ovulation induction and IVF. To establish, based on this information, guidelines for safe and successful assisted reproductive technology (ART). Design A MEDLINE computer search was performed to identify relevant articles. Result(s) Systemic lupus erythematosus and antiphospholipid syndrome are not related to infertility, except for cases of amenorrhea accompanying severe flares, renal insufficiency-related hypofertility, and ovarian failure secondary to cyclophosphami…