Comparazione dei parametri emodinamici indiretti rilevati con tecniche non invasive (bioimpedenziometria e studio dell'onda sfigmica radiale)

La valutazione dello stato emodinamico è una procedura fondamentale nella valutazione del paziente in condizioni critiche. Il sistema più diffuso per la determinazione della portata cardiaca e dell’indice cardiaco è quello della termodiluizione, che prevede l’inserimento del catetere di Swan-Ganz in arteria polmonare, procedura invasiva, associata a diversi rischi e complicanze. È, quindi, sorta la necessità di sviluppare metodiche alternative e meno invasive per la determinazione della portata cardiaca. Obiettivo di questa tesi è ricercare un’eventuale correlazione tra i parametri emodinamici misurati tramite due metodiche non invasive: l’analisi dell’onda sfigmica radiale, tramite il Pressure Recording Analytical Method (PRAM), e la bioimpedenziometria periferica. Il PRAM è basato sull’analisi della forma della curva pressoria e permette la valutazione dello stroke volume attraverso la registrazione continua del segnale pressorio. Tramite un catetere posizionato in arteria radiale, collegato ad un trasduttore, si sono acquisiti i segnali pressori ad una frequenza di 1000Hz. Le variabili prese in esame sono state: SV, CO, CI. La bioimpedenziometria è una tecnica utilizzata nella valutazione della composizione corporea, basata sulle proprietà elettriche dei tessuti e in particolare sull’impedenza, che misura l’opposizione da parte dei tessuti al flusso di una corrente elettrica. I parametri della bioimpedenziometria (resistenza, reattanza e angolo di fase) sono stati misurati in Ohms, attraverso una corrente di 0,3 mA a una frequenza sinusoidale di 50 KHz. Sono stati posizionati due elettrodi sensori a livello del polso e della caviglia e due elettrodi stimolatori a livello del terzo osso metacarpale e del terzo metatarsale. I parametri del PRAM e della bioimpedenziometria sono stati misurati su ciascun paziente ogni due ore. In questa tesi si è cercato di stabilire l’utilità della bioimpedenziometria periferica come sussidio clinico nella determinazione della portata cardiaca

Metformin-associated lactic acidosis (MALA) in Unità di Terapia Intensiva: studio retrospettivo

La metformina è l’ipoglicemizzante orale più prescritto al mondo ed è considerato la prima linea terapeutica per il Diabete di tipo 2. Con all’incirca di 50 anni di esperienza clinica globale, la metformina è generalmente considerata sicura, con effetti avversi per lo più a carico del sistema gastro-intestinale: diarrea, nausea e vomito. La metformina è controindicata nell’insufficienza epatica o renale, nei pazienti molto anziani e in pazienti con disfunzione circolatoria, come l’insufficienza cardiaca congestizia, a causa dell’aumentato rischio di acidosi lattica. Sebbene l’acidosi lattica associata a metformina (MALA) sia una condizione rara (circa 10 casi/100.000 pazienti/anno), casi continuano ad essere riportati, con una mortalità del 40-50%. A causa della sintomatologia variegata ed aspecifica, l’acidosi lattica associata a metformina è spesso difficile da predire e diagnosticare. Il presente studio retrospettivo è stato condotto presso l’Unità di Terapia Intensiva, Anestesia ed Elisoccorso della ASL 1 di Massa Carrara. Sono stati valutati i pazienti ammessi in UTI nel periodo compreso tra Gennaio 2013 e Dicembre 2015 in seguito ad acidosi da metformina, secondo i seguenti criteri di inclusione: terapia cronica con metformina; acidosi lattica, definita come pH 5 mmol/L e livelli di bicarbonato < 22 mmol/L

Work Hard, Play Hard: Collecting Acceptability Annotations through a 3D Game

Corpus-based studies on acceptability judgements have always stimulated the interest of researchers, both in theoretical and computational fields. Some approaches focused on spontaneous judgements collected through different types of tasks, others on data annotated through crowd-sourcing platforms, still others relied on expert annotated data available from the literature. The release of CoLA corpus, a large-scale corpus of sentences extracted from linguistic handbooks as examples of acceptable/non acceptable phenomena in English, has revived interest in the reliability of judgements of linguistic experts vs. non-experts. Several issues are still open. In this work, we contribute to this debate by presenting a 3D video game that was used to collect acceptability judgments on Italian sentences. We analyse the resulting annotations in terms of agreement among players and by comparing them with experts{'} acceptability judgments. We also discuss different game settings to assess their impact on participants{'} motivation and engagement. The final dataset containing 1,062 sentences, which were selected based on majority voting, is released for future research and comparisons

Significance of phenylpropanoid pathways in the response of two pomegranate cultivars to salinity and ozone stress

Secondary metabolites play a pivotal role in defense mechanisms, especially in plant-environment interactions. However, there are still difficulties in ascertaining the metabolic effect of their production due to individual and/ or combined stress, given the variety of simultaneous and interconnected effects of multiple stresses to metabolic processes in plants. Here, two pomegranate cultivars (Wonderful and Parfianka) were subjected to moderate levels of salt (i.e., 100 mM NaCl for 35 consecutive days) and sequentially exposed to a realistic O3 concentration (i.e., 100 ppb for 5 h) to evaluate how NaCl treatment and/or O3 fumigation alter the leaf polyphenolic composition, and what is the role of metabolites and enzymes involved in the phenylpropanoid pathway during sequential abiotic stresses. Wonderful leaves responded to NaCl or O3 treatments through the production/ accumulation of cinnamic acid derivatives (more than 3-fold higher than controls) and by exhibiting chemical composition plasticity against oxidative stress. The unchanged concentrations of benzoic acid derivatives indicate that treated Wonderful leaves could diversify the components of polyphenolic compounds and induce the biosynthesis of the components available (e.g., ellagitannins and punicalagin). During sequential abiotic stresses, Wonderful leaves needed few cellular adjustments to maintain oxidative stress under control (especially during the recovery time). On the other hand, Parfianka leaves had phenolics/polyphenolics amount (at constitutive level) suitable to face out the environmental changes (occurring singly or sequentially) so that no rearrangement of metabolites and enzymes involved in the phenylpropanoid pathway was required. Consequently, it is possible to conclude that Parfianka is more salt- and O3-tolerant than Wonderful

DH-FBK @ HaSpeeDe2: Italian Hate Speech Detection via Self-Training and Oversampling

We describe in this paper the system submitted by the DH-FBK team to the HaSpeeDe evaluation task, and dealing with Italian hate speech detection (Task A). While we adopt a standard approach for fine-tuning AlBERTo, the Italian BERT model trained on tweets, we propose to improve the final classification performance by two additional steps, i.e. self-training and oversampling. Indeed, we extend the initial training data with additional silver data, carefully sampled from domain-specific tweets and obtained after first training our system only with the task training data. Then, we re-train the classifier by merging silver and task training data but oversampling the latter, so that the obtained model is more robust to possible inconsistencies in the silver data. With this configuration, we obtain a macro-averaged F1 of 0.753 on tweets, and 0.702 on news headlines

Ozone-elicited secondary metabolites in shoot cultures of Melissa officinalis L.

The effects of ozone treatment (200 ppb, 3 h) on the accumulation of main secondary metabolites have been investigated in Melissa officinalis (lemon balm) aseptic shoot cultures in order to evaluate the biotechnological application of this gas for improving the yield of secondary metabolites of medicinal plants. During the treatment, we found (i) an activation of enzymes involved in phenolic metabolism [as confirmed by the increase of shikimate dehydrogenase, phenylalanine ammonia-lyase and cinnamyl alcohol dehydrogenase activities (about twofold higher than controls)], (ii) a development of cellular barriers with a higher degree of polymerization of monolignols [as indicated by the increase of lignin (+23% compared to controls)], (iii) an accumulation of phenolic compounds, in particular rosmarinic acid (about fourfold compared to control plants cultivated in filtered air) and (iv) an increase of antioxidant capacity [as documented by the improved 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging activity]. The effect of ozone as elicitor of the production of secondary metabolites in lemon balm shoot cultures was dependent on the specific regime, the time of exposure and the concentration of the stressor. After the end of the treatment, we found cell death and hydrogen peroxide (H2O2) deposition concomitant with a prolonged superoxide anion-generation suggesting that a transient oxidative burst had occurre

Detailing the Self-Discharge of a Cathode Based on a Prussian Blue Analogue

Prussian Blue analogues (PBAs) are a promising class of electrode active materials for batteries. Among them, copper nitroprusside, Cu[Fe(CN)5NO], has recently been investigated for its peculiar redox system, which also involves the nitrosyl ligand as a non-innocent ligand, in addition to the electroactivity of the metal sites, Cu and Fe. This paper studies the dynamics of the electrode, employing surface sensitive X-ray Photoelectron spectroscopy (XPS) and bulk sensitive X-ray absorption spectroscopy (XAS) techniques. XPS provided chemical information on the layers formed on electrode surfaces following the self-discharge process of the cathode material in the presence of the electrolyte. These layers consist mainly of electrolyte degradation products, such as LiF, LixPOyFz and LixPFy. Moreover, as evidenced by XAS and XPS, reduction at both metal sites takes place in the bulk and in the surface of the material, clearly evidencing that a self-discharge process is occurring. We observed faster processes and higher amounts of reduced species and decomposition products in the case of samples with a higher amount of coordination water

Losing the warning signal: Drought compromises the cross-talk of signaling molecules in quercus ilex exposed to ozone

Understanding the interactions between drought and acute ozone (O3) stress in terms of signaling molecules and cell death would improve the predictions of plant responses to climate change. The aim was to investigate whether drought stress influences the responses of plants to acute episodes of O3 exposure. In this study, the behavior of 84 Mediterranean evergreen Quercus ilex plants was evaluated in terms of crosstalk responses among signaling molecules. Half of the sample was subjected to drought (20% of the effective daily evapotranspiration, for 15 days) and was later exposed to an acute O3 exposure (200 nL L-1 for 5 h). First, our results indicate that in well-water conditions, O3 induced a signaling pathway specific to O3-sensitive behavior. Second, different trends and consequently different roles of phytohormones and signaling molecules (ethylene, ET; abscisic acid, ABA; salycilic acid, SA and jasmonic acid, JA) were observed in relation to water stress and O3. A spatial and functional correlation between these signaling molecules was observed in modulating O3-induced responses in well-watered plants. In contrast, in drought-stressed plants, these compounds were not involved either in O3-induced signaling mechanisms or in leaf senescence (a response observed in water-stressed plants before the O3-exposure). Third, these differences were ascribable to the fact that in drought conditions, most defense processes induced by O3 were compromised and/or altered. Our results highlight how Q. ilex plants suffering from water deprivation respond differently to an acute O3 episode compared to well-watered plants, and suggest new effect to be considered in plant responses to environmental changes. This poses the serious question as to whether or not multiple high-magnitude O3 events (as predicted) can change these cross-talk responses, thus opening it up possible further investigations