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

TECNOLOGIE FOTOVOLTAICHE PER LO SVILUPPO SOSTENIBILE. Analisi del ciclo di vita, convenienza energetica, diffusione delle utilizzazioni, futuri scenari

Viene descritto il ciclo di vita di un’installazione fotovoltaica tipo con moduli a celle in silicio cristallino a contatti stampati. La trattazione è condotta tenendo conto della metodologia LCA (alla quale sono dedicati due paragrafi di approfondimento) ed è divisa in due parti: la prima è dedicata ai processi prettamente industriali, divisi in dieci fasi consecutive, dall’estrazione delle materie prime al riciclaggio, ed è corredata di opportuni bilanci; la seconda riguarda tematiche connesse. Vengono descritte le più importanti tecnologie FV sviluppate, ad ognuna delle quali è dedicato un paragrafo. Segue uno sguardo alle diffusione e agli impieghi del fotovoltaico, con un accenno alla sua potenzialità e possibili sviluppi. Per completezza sono inclusi una breve storia delle tecnologie FV e la descrizione dell’effetto fotovoltaico

Characterization of the neuroendocrine pancreatic tumors nature by MDCT enhancement pattern: a radio-pathological correlation

Introduction Pre-operative suspicion of neuroendocrine pancreatic lesions nature arises both from clinical (presence and the type of secreted hormone) and imaging findings. However, imaging suggestion of lesion nature is based quite only on nodular dimension and on the presence of local and distant spreading. Aim of the study was to determine the nature of neuroendocrine pancreatic lesions by analysing lesions enhancement pattern at MDCT and by comparing it with histological findings, including the MVD. Materials and Methods We included 45 patients submitted to surgical resection for pancreatic neuroendocrine tumor. All preoperative CT examinations were performed by a multidetector CT. Post-contrastographic study included 4 phases: early arterial (delay 15-20”), pancreatic (delay 35”), venous (delay 70”) and late phases (delay 180”). Two different patterns of enhancement were defined: pattern A, including lesions showing early enhancement (during early arterial or pancreatic phase) and a rapid wash-out; pattern B, including lesions with wash-in in the early arterial or pancreatic phase with no wash-out nor in the late phase (pattern B1), and lesions showing enhancement only in the venous and/or late phases (pattern B2). Results 66 lesions were detected (30 pattern A, 26 B1 and 10 B2). At pathology 28 lesions were adenomas, 14 borderline and 24 carcinomas: 24/30 lesions showing pattern A were benign, 5 borderline and 1 carcinoma; 23/36 lesions showing pattern B were carcinomas, 9 borderline and 4 adenomas. Among the 26 B1 lesions, 13 were carcinomas, 9 borderline and 4 adenomas, while all 10 B2 lesions were malignant. Pattern A showed PPV of benignancy of 80%, and pattern B NPV of benignancy of 89%. MVD was evaluated in 22 lesions obtaining significant differences among the 3 histological and the 3 enhancement pattern. Significant differences between B1 and B2 malignant lesions existed by considering metastases (only B2 lesions) and fibrosis (all B2 lesions). Conclusion The enhancement pattern at CT is related to MVD and the histological type, thus representing a further criterium for suggesting nature of neuroendocrine lesions. The low MVD of B2 lesions, associated with the presence of fibrosis, may justify the delayed enhancement of these lesions

Vector-like quarks in a composite Higgs model

Vector-like quarks are a common feature of "composite" Higgs models, where they intervene in cutting off the top-loop contribution to the Higgs boson mass and may, at the same time, affect the Electroweak Precision Tests (EWPT). A model based on SO(5)/SO(4) is here analyzed. In a specific non minimal version, vector-like quarks of mass as low as 300-500 GeV are allowed in a thin region of its parameter space. Other models fail to be consistent with the EWPT.Comment: 17 pages with 8 figures Small modifications according to JHEP requirement

Stent-assisted reconstructive endovascular repair of intracranial aneurysms: long-term clinical and angiographic follow-up

Abstract Background and Purpose: The development of self-expanding stents dedicated to intracranial use has significantly widened the applicability of endovascular therapy to many intracranial aneurysms. The purpose of this study was to report the angiographic and clinical outcomes of wide-necked intracranial aneurysms treated with stent. Methods: Between January 2007 and October 2011 we deployed 22 stents in 20 patients with wide-necked cerebral aneurysms. Inclusion criteria restricted the group to adult patients with wide-necked intracranial aneurysms (ruptured and unruptured lesions). Immediate post-procedural angiographic studies were performed to evaluate successful occlusion of the aneurysm as well as patency of the parent vessel. We assessed long term angiography follow-up to detect in-stent stenosis, progressive thrombosis, recurrence and need for retreatment. Clinical outcome was assessed with the modifing Ranking Scale (mRS). Results: Technical success was obtained in all 22 (100%) cases. Angiography immediately after treatment procedure showed complete occlusion in 7 aneurysms (35%), neck remnant in 11 (55%), incomplete occlusion in 1 (5%) and partial occlusion in 1 (5%). During the endovascular embolization procedure no rupture of the sac or bleeding complication occurred; none of the patients needed undergoing surgical crossover. Procedure-related adverse events occurred in one (5%) patient: a brachial artery pseudoaneurysm. Three (15%) patients had neurological complications after procedure, whose 1 (5%) transitory complication spontaneusly resolved. Two patients (10%), had acute complete in-stent thrombosis which resolved after intraarterial administration of abciximab and placement of a new stent in-stent. Of the 20 patients treated with stent deployment, a follow-up imaging study was available in all 19 surviving patients (95%) at an average of 16.2 months (range, 6 to 50 months). The first follow-up DSA, compared with initial angiography, showed no changes in 14 aneurysms (73.7%), progressive thrombosis in 3 (15.7%), and major recurrence in 2 (10.5%). The overall rate of succesful procedure to 6 months is 89.5%; there was 1 case of asintomatic moderate endothelial hyperplasia. The further follow-up imaging study, showed no changes in 17 (89.5%) of the 19 surviving patients, 1 progressive thrombosis and 1 minor recurrence. One month- and long term (average of 16.2 months; range, 6 to 50 months) clinical follow-up showed no worsening in the mRS in 18 (90%) of 20 patients, 1 (5%) mRS 2 and 1 (5%) mRS 6. All the survived patients are alive and we did not observe periprocedural or long-term intracranial bleeding events or symptomatic stent related stenosis/occlusion complication. Conclusions: Our findings suggest that the endovascular treatment of intracranial aneurysms by stenting is feasible, effective and safe; follow-up results proved intact parent arteries and stable occlusion rates in the majority of treated aneurysms. Nevertheless, long-term data on safety and efficacy and larger patient groups are necessary

Antidepressants for Major Depressive Disorder and Dysthymic Disorder in patients with co-morbid Alcohol Use Disorders: state of the art and a meta-analysis of placebo-controlled randomized trials.

Abstract Major depressive disorder (MDD) and dysthymic disorder (DD) are often complicated by the co-occurrence of alcohol use disorders (AUDs), each condition often aggravating the course and outcome of the other in terms of severity, functional impairment, risk of suicide, relapse of depression and drinking behaviors, and chronicity. Recently, there has been some evidence that antidepressants may improve depressive symptoms in patients with concurrent AUDs, even if they have only a limited effect in decreasing alcohol use in these subjects. To date, however, there is a paucity of randomized, double-blind, placebo-controlled trials that have been conducted to evaluate the efficacy, safety, and tolerability of antidepressants as monotherapy for patients with MDD/DD and co-occurring AUDs. Although previous meta-analyses have found antidepressants to be more effective than placebo in the treatment of this specific patient population, efficacy for newer agents (i.e. the SSRIs) was questionable. The aim of this study is to examine the efficacy of antidepressants in patients with unipolar depression (MDD and/or DD) with co-morbid AUDs, and to compare compare study design characteristics, patient characteristics, and drug-/placebo- outcomes between depressed patients with or without co-morbid AUDs. Method Medline/Pubmed publication databases were searched for randomized, double-blind, placebo-controlled trials of antidepressants used as monotherapy for the acute-phase treatment of MDD and/or DD in patients with or without AUDs. The search was limited to articles published between January 1980 and March 2010 (inclusive). We selected for studies which focused on the treatment of adult patients, were at least 4 weeks of duration, used antidepressants in their oral formulation, and used either the Hamilton Depression Rating Scale (HDRS), the Montgomery-Asperg Depression Rating Scale (MADRS), or the Clinical Global Impression-Improvement Scale (CGI) as one of their outcome measures. The primary outcome for our meta-analysis was clinical response, defined as a 50% or greater reduction in HDRS or MADRS scores, baseline to endpoint, or a CGI-I<3 at the final visit. Results A total of 195 manuscripts were found eligible for inclusion in our analysis (n=46,820 patients), 11 of which focused on the treatment of MDD/DD in patients with co-morbid AUDs. We found that antidepressant therapy was more effective than placebo in patients with co-morbid AUDs (RR=1.336; p=0.021), but not when SSRIs were examined alone (RR= 1.145; p=0.316). There was no difference in the relative efficacy of antidepressants (versus placebo) when comparing studies in MDD/DD patients with or without AUDs (p=0.973). Meta-regression analyses yielded no significant differences in the RR of responding to antidepressants versus placebo in trials with co-morbid AUDs whether antidepressants were used alone or adjunctively to psychotherapy, whether used in patients actively drinking or recently sober, or whether used in pure MDD or in combined MDD and DD populations. Moreover, the baseline severity of drinking (assessed as the number of heavy drinking days in the week before randomization) did not predict a significantly difference in the response rate to antidepressants (coefficient= -0.644, p=0.467). Finally, there was no statistically significant difference in the percentage of heavy drinking days at the end of the study between antidepressant- and placebo- treated patients (RR = 0.691, p=0.275) Conclusions Our results suggests that antidepressants are more effective than placebo in treating depression in patients with co-morbid AUDs, and lend further support to the argument that antidepressants should represent first-line therapy for targeting depressive symptoms in patients with alcohol use disorders, a condition which is highly prevalent and is associated with high rates of medical and psychiatric comorbidity, disability, and increased use of general medical health services as well as psychiatric hospitalizations. However, the use of SSRIs for treating depression in such patients is not convincingly supported by the evidence. More data on the use of newer antidepressants, including SNRIs and SSRIs, for this select patient population are needed. Moreover, our work showed that the efficacy of antidepressants was not influenced whether patients were actively drinking or recently sober, and we did not find any relationship between the severity of baseline drinking and treatment outcome. This suggests that the decision whether to recommend antidepressants in this patient population should not be determined by these variables, at least as far as the potential efficacy of treatment is concerned

simulatori di sistemi di comunicazione su fibra ottica

La tesi rappresenta una ricerca accurata in rete dei principali e più sofisticati software di simulazione di sistemi di comunicazione ottica. Lo sviluppo sempre maggiore e a basso costo di reti di telecomunicazionie, basate su tecniche di trasmissione ottica su fibra, ha spinto le aziende a investire sulla creazione di sistemi software sempre piu’ avanzati in grado di progettare,simulare e analizzare sistemi di comunicazione ottica anche molto complessi. Esistono software in grado di simulare sia l’intero sistema ottico che i singoli dispositivi ottici che lo compongono,come generatori di segnale,laser,modulatori,fibre,ricevitori ottici,amplificatori ottici,multiplatori e altri ancora. In un progetto di sistema di trasmissione,il cui scopo fondamentale è il trasferimento da una sorgente ad un utilizzatore di un segnale portatore di informazione,bisogna sfruttare al massimo e quindi ottimizzare le risorse caratteristiche del mezzo fisico,cioe’ del mezzo portante. E’ proprio grazie a questi software di simulazione che riusciamo ad effettuare previsioni su un particolare collegamento ottico,riuscendo cosi’ ad ottimizzare le risorse a nostra disposizione,diminuendo notevolmente i costi,che invece si avrebbero con delle prove sperimentali. Quindi questa tesi vuole essere una guida,per chiunque fosse interessato,ai principali software di simulazione di questo tipo di sistemi presenti sul mercato. L’uso del linguaggio html rende tale guida di facile utilizzo e di rapida consultazione

Sintesi di nuovi ligandi della Glicoproteina-P a struttura Ariletilanilinica per lo sviluppo di traccianti per la PET

Le ATP-binding cassette transporters (trasportatori ABC),fanno parte di una superfamiglia proteica molto diffusa in diversi tipi di organismi: dai procarioti all’uomo. In quest’ultimo,derivano dall’espressione di 49 geni dai quali si originano ben 7 sottoclassi : ABC-A G. Sono proteine transmembrana,che sono in grado di regolare il passaggio di diverse tipologie di sostanze attraverso queste barriere. Per poter svolgere tale funzione, necessitano di una fonte energetica,la quale è costituita dall’ATP (adenosina trifosfato) e dalla sua successiva idrolisi. Per questo motivo,questi trasportatori sono,a tutti gli effetti,delle “pompe di membrana”. Possiamo,inoltre,operare una loro suddivisione anche in base alla direzione secondo la quale le sostanze vengono trasportate,abbiamo : • Importatori • Esportatori/Efflussori Gli Importatori sono presenti solo nei Procarioti. Invece,negli Eucarioti,si riscontra la esclusiva presenza degli Esportatori. Quest’ultimi,esercitano una funzione protettiva contrastando l’accumulo di moltissime tipologie di sostanze potenzialmente pericolose o per un determinato distretto fisiologico o per la sopravvivenza della singola cellula. Ne consegue che posseggano la capacità di interagire con una vasta gamma di substrati,strutturalmente e funzionalmente,molto diversi fra loro : dai metaboliti ai lipidi,dagli steroli ai farmaci. Grazie a questa capacità,si riscontra la loro presenza all’interno di numerosissime membrane di diversi distretti biologici,come : -Barriera Emato-Encefalica (BEE) -Placenta -Intestino -Stomaco -Fegato Essendo proteine trasportatrici,è pacifico che influenzino o siano coinvolte direttamente anche nella regolazione di molti processi cellulari. Questo ha fatto sì che,col tempo,siano state sempre di più oggetto di studi e ricerca. Fra queste, particolare interesse,lo ha suscitato la ABC-B1,altresì nota come Glicoproteina-P (P-gp),soprattutto a causa del suo ruolo in alcune patologie neuro-degenerative (Parkinson,Alzheimer) e tumorali. In questo senso,l’aspetto sul quale la ricerca si sta concentrando negli ultimi anni,è,oltre alla caratterizzazione delle sue funzioni e della sua struttura,la valutazione della sua espressione in condizioni normali e patologiche. Potenzialmente,potrebbe rappresentare uno dei bersagli principali,sia per quanto riguarda la diagnosi che il trattamento,di tali patologie. I vantaggi,teorici,che si potrebbero riscontrare sono svariati e riguardano : la maggiore capacità di diagnosi delle patologie,l’aumento della biodisponibilità dei farmaci,i migliori risultati terapeutici,la riduzione delle dosi,la riduzione della probabilità che insorgano effetti collaterali e fenomeni di resistenza ai farmaci,l’aumento della qualità di vita dei pazienti e la riduzione della spesa farmaceutic

MONOAMINE OXIDASE A (MAOA), CHILDHOOD TRAUMA, ALCOHOLISM AND AGGRESSION

Women who have experienced childhood sexual abuse (CSA) have an increased risk of alcoholism and antisocial personality disorder (ASPD). Among males, a functional polymorphism (MAOA-LPR, monoamine oxidase A linked polymorphic region) in the promoter region of the monoamine oxidase A gene (MAOA) appears to moderate the effect of childhood maltreatment on antisocial behavior. Our aim was to test whether MAOA-LPR influences the impact of CSA on alcoholism and ASPD in a sample of 291 women, 50% of whom have experienced CSA; we also tested whether haplotypes covering the region where both MAOA and monoamine oxidase B (MAOB) genes are located predict risk of alcoholism and ASPD better than the MAOA-LPR locus alone. Participants included 168 alcoholics (39 with ASPD [antisocial alcoholics]) and 123 controls (no Alcoholics, no ASPD). Antisocial behavior was also modeled as a continuous trait: ASPD symptoms count. The MAOA-LPR low activity allele was associated with alcoholism (p=0.005), particularly antisocial alcoholism (p=0.00009), only among sexually-abused subjects. Sexually-abused women who were homozygous for the low activity allele had higher rates of alcoholism and ASPD, and more ASPD symptoms, than abused women homozygous for the high activity allele. Heterozygous women displayed an intermediate risk pattern. In contrast, there was no relationship between alcoholism/antisocial behavior and MAOA-LPR genotype among non-abused women. The MAOA-LPR low activity allele was found on three different haplotypes. The most abundant MAOA haplotype containing the MAOA-LPR low activity allele was found in excess among alcoholics (p=0.008) and antisocial alcoholics (p=0.001). Finally, a MAOB haplotype, that we termed haplotype C, was significantly associated with alcoholism (p=0.006), and to a lesser extent with antisocial alcoholism (p=0.03). In conclusions, MAOA seems to moderate the impact of childhood trauma on adult psychopathology in females in the same way as previously shown among males. The MAOA-LPR low activity allele appears to confer increased vulnerability to the adverse psychosocial consequences of CSA. Haplotype-based analysis of the MAOA gene appeared to strengthen the association, as compared to the MAOA-LPR locus alone. A MAOB haplotype was associated with alcoholism independently from ASPD