Metodologia Per la Caratterizzazione di amplificatori a basso rumore per UMTS

In questo lavoro si presenta una metodologia di progettazione elettronica a livello di sistema, affrontando il problema della caratterizzazione dello spazio di progetto dell' amplificatore a basso rumore costituente il primo stadio di un front end a conversione diretta per UMTS realizzato in tecnologia CMOS con lunghezza di canale .18u. La metodologia è sviluppata al fine di valutare in modo quantititativo le specifiche ottime di sistema per il front-end stesso e si basa sul concetto di Piattaforma Analogica, che prevede la costruzione di un modello di prestazioni per il blocco analogico basato su campionamento statistico di indici di prestazioni del blocco stesso, misurati tramite simulazione di dimensionamenti dei componenti attivi e passivi soddisfacenti un set di equazioni specifico della topologia circuitale. Gli indici di prestazioni vengono successivamente ulizzati per parametrizzare modelli comportamentali utilizzati nelle fasi di ottimizzazione a livello di sistema. Modelli comportamentali atti a rappresentare i sistemi RF sono stati pertanto studiati per ottimizzare la scelta delle metriche di prestazioni. L'ottimizzazione dei set di equazioni atti a selezionare le configurazione di interesse per il campionamento ha al tempo stesso richiesto l'approfondimento dei modelli di dispositivi attivi validi in tutte le regioni di funzionamento, e lo studio dettagliato della progettazione degli amplificatori a basso rumore basati su degenerazione induttiva. Inoltre, il problema della modellizzazione a livello di sistema degli effetti della comunicazione tra LNA e Mixer è stato affrontato proponendo e analizzando diverse soluzioni. Il lavoro ha permesso di condurre un'ottimizzazione del front-end UMTS, giungendo a specifiche ottime a livello di sistema per l'amplificatore stesso

Escherichia coli Is Overtaking Group B Streptococcus in Early-Onset Neonatal Sepsis

The widespread use of intrapartum antibiotic prophylaxis (IAP) to prevent group B streptococcus (GBS) early-onset sepsis (EOS) is changing the epidemiology of EOS. Italian prospective area-based surveillance data (from 1 January 2016 to 31 December 2020) were used, from which we identified 64 cases of culture-proven EOS (E. coli, n = 39; GBS, n = 25) among 159,898 live births (annual incidence rates of 0.24 and 0.16 per 1000, respectively). Approximately 10% of E. coli isolates were resistant to both gentamicin and ampicillin. Five neonates died; among them, four were born very pre-term (E. coli, n = 3; GBS, n = 1) and one was born full-term (E. coli, n = 1). After adjustment for gestational age, IAP-exposed neonates had ≥95% lower risk of death, as compared to IAP-unexposed neonates, both in the whole cohort (OR 0.04, 95% CI 0.00-0.70; p = 0.03) and in the E. coli EOS cohort (OR 0.05, 95% CI 0.00-0.88; p = 0.04). In multi-variable logistic regression analysis, IAP was inversely associated with severe disease (OR = 0.12, 95% CI 0.02-0.76; p = 0.03). E. coli is now the leading pathogen in neonatal EOS, and its incidence is close to that of GBS in full-term neonates. IAP reduces the risk of severe disease and death. Importantly, approximately 10% of E. coli isolates causing EOS were found to be resistant to typical first-line antibiotics

Prediction of morbidity and mortality after early cholecystectomy for acute calculous cholecystitis : results of the SPRi.MACC study

Peer reviewe

Histone Deacetylase Inhibition Enhances Self Renewal and Cardioprotection by Human Cord Blood-Derived CD34+ Cells

Abstract BACKGROUND: Use of peripheral blood- or bone marrow-derived progenitors for ischemic heart repair is a feasible option to induce neo-vascularization in ischemic tissues. These cells, named Endothelial Progenitors Cells (EPCs), have been extensively characterized phenotypically and functionally. The clinical efficacy of cardiac repair by EPCs cells remains, however, limited, due to cell autonomous defects as a consequence of risk factors. The devise of "enhancement" strategies has been therefore sought to improve repair ability of these cells and increase the clinical benefit. PRINCIPAL FINDINGS: Pharmacologic inhibition of histone deacetylases (HDACs) is known to enhance hematopoietic stem cells engraftment by improvement of self renewal and inhibition of differentiation in the presence of mitogenic stimuli in vitro. In the present study cord blood-derived CD34(+) were pre-conditioned with the HDAC inhibitor Valproic Acid. This treatment affected stem cell growth and gene expression, and improved ischemic myocardium protection in an immunodeficient mouse model of myocardial infarction. CONCLUSIONS: Our results show that HDAC blockade leads to phenotype changes in CD34(+) cells with enhanced self renewal and cardioprotection

Textbook outcome in urgent early cholecystectomy for acute calculous cholecystitis: results post hoc of the S.P.Ri.M.A.C.C study

Introduction: A textbook outcome patient is one in which the operative course passes uneventful, without complications, readmission or mortality. There is a lack of publications in terms of TO on acute cholecystitis. Objetive: The objective of this study is to analyze the achievement of TO in patients with urgent early cholecystectomy (UEC) for Acute Cholecystitis. and to identify which factors are related to achieving TO. Materials and methods: This is a post hoc study of the SPRiMACC study. It ́s a prospective multicenter observational study run by WSES. The criteria to define TO in urgent early cholecystectomy (TOUEC) were no 30-day mortality, no 30-day postoperative complications, no readmission within 30 days, and hospital stay ≤ 7 days (75th percentile), and full laparoscopic surgery. Patients who met all these conditions were taken as presenting a TOUEC. Outcomes: 1246 urgent early cholecystectomies for ACC were included. In all, 789 patients (63.3%) achieved all TOUEC parameters, while 457 (36.6%) failed to achieve one or more parameters and were considered non-TOUEC. The patients who achieved TOUEC were younger had significantly lower scores on all the risk scales analyzed. In the serological tests, TOUEC patients had lower values for in a lot of variables than non-TOUEC patients. The TOUEC group had lower rates of complicated cholecystitis. Considering operative time, a shorter duration was also associated with a higher probability of reaching TOUEC. Conclusion: Knowledge of the factors that influence the TOUEC can allow us to improve our results in terms of textbook outcome

Physics with the KLOE-2 experiment at the upgraded DAϕ\phiNE

Investigation at a $\phi$--factory can shed light on several debated issues in particle physics. We discuss: i) recent theoretical development and experimental progress in kaon physics relevant for the Standard Model tests in the flavor sector, ii) the sensitivity we can reach in probing CPT and Quantum Mechanics from time evolution of entangled kaon states, iii) the interest for improving on the present measurements of non-leptonic and radiative decays of kaons and eta/eta$^\prime$ mesons, iv) the contribution to understand the nature of light scalar mesons, and v) the opportunity to search for narrow di-lepton resonances suggested by recent models proposing a hidden dark-matter sector. We also report on the $e^+ e^-$ physics in the continuum with the measurements of (multi)hadronic cross sections and the study of gamma gamma processes.Comment: 60 pages, 41 figures; added affiliation for one of the authors; added reference to section

Design of a system for cm-range wireless communications

The continuous growth in the number of mobile phone subscribers, which exceeded 3 billions by 2007 , and of the number of wireless devices and systems, led to visions of a near future in which wireless technology is so ubiquitous that 1000 Radios per person will exist. In this context, ad-hoc area networks between several consumer electronic devices located within a meter of each other will be necessary in order to reduce traffic towards the base station and reduce power consumption and interference generation. As existing air interfaces still both radiate and dissipate an order of magnitude higher power than what this future scenario requires, a new, low-power radio technology must be developed. In this thesis, we develop a low-power transceiver with range of a few centimeters targeted to mobile-mobile data exchange. The same transceiver could also be employed in some implanted applications, as well as in distributed industrial control environments. \\ The design of the air-interface for this cm-range communication system at the propagation, system and circuit levels. First, we describe an optimization methodology that enables the designer to choose, for any given antenna design, which carrier frequency results in the maximum receiver Signal-To-Noise-Ratio (SNR). We then show how by using impulse-radio signaling, the chosen high-SNR channel can be leveraged to simplify the radio receiver architecture to the simplest possible RF receiver-consisting only of an RF rectifier. To mitigate the known issues of sensitivity to interference for these rectifier-based receivers, a technique to improve selectivity that uses only baseband processing and requires no RF prefilter is introduced. These techniques are demostrated by a transceiver test chip, implemented in a 65nm CMOS process . The transceiver dissipates 250 &mu W in receive mode, and 25 &mu W in transmit mode when operating at 1Mbps , and it integrates a timing-recovery loop that achieves jitter lower than 2nS while consuming 45 &mu W.This figures correspond to an energy per bit of 300pJ, which compares favorably with current state-of-the art

Design of a system for cm-range wireless communications

The continuous growth in the number of mobile phone subscribers, which exceeded 3 billions by 2007 , and of the number of wireless devices and systems, led to visions of a near future in which wireless technology is so ubiquitous that 1000 Radios per person will exist. In this context, ad-hoc area networks between several consumer electronic devices located within a meter of each other will be necessary in order to reduce traffic towards the base station and reduce power consumption and interference generation. As existing air interfaces still both radiate and dissipate an order of magnitude higher power than what this future scenario requires, a new, low-power radio technology must be developed. In this thesis, we develop a low-power transceiver with range of a few centimeters targeted to mobile-mobile data exchange. The same transceiver could also be employed in some implanted applications, as well as in distributed industrial control environments. \\ The design of the air-interface for this cm-range communication system at the propagation, system and circuit levels. First, we describe an optimization methodology that enables the designer to choose, for any given antenna design, which carrier frequency results in the maximum receiver Signal-To-Noise-Ratio (SNR). We then show how by using impulse-radio signaling, the chosen high-SNR channel can be leveraged to simplify the radio receiver architecture to the simplest possible RF receiver-consisting only of an RF rectifier. To mitigate the known issues of sensitivity to interference for these rectifier-based receivers, a technique to improve selectivity that uses only baseband processing and requires no RF prefilter is introduced. These techniques are demostrated by a transceiver test chip, implemented in a 65nm CMOS process . The transceiver dissipates 250 &mu W in receive mode, and 25 &mu W in transmit mode when operating at 1Mbps , and it integrates a timing-recovery loop that achieves jitter lower than 2nS while consuming 45 &mu W.This figures correspond to an energy per bit of 300pJ, which compares favorably with current state-of-the art