4,146 research outputs found

    Safety and efficacy of travoprost solution for the treatment of elevated intraocular pressure

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    Travoprost is a prostaglandin analogue widely used for reducing intraocular pressure (IOP) in patients affected with glaucoma and ocular hypertension. It exerts its ocular hypotensive effect through the prostaglandin FP receptors, located in the ciliary muscle and the trabecular meshwork. Several studies have shown that topical administration of travoprost induces a mean IOP reduction ranging from 25% to 32%, and sustained throughout the 24-hour cycle. When compared with timolol, travoprost is more effective at reducing IOP, while generally no difference has been found in the head-to-head comparison with other prostaglandin analogues. The fixed combination of travoprost and timolol has demonstrated a hypotensive efficacy comparable to the concomitant administration of the two drugs. Recently, a new preservative-free formulation of travoprost 0.004% has been marketed for reducing tolerability-related problems in subjects affected with ocular surface disease. Low rates of topical and systemic adverse reactions, strong ocular hypotensive efficacy, and once-a-day dosing make travoprost a first-line treatment for patients affected with elevated IOP

    The effect of posture on asynchronous chest wall movement in COPD

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    Priori R, Aliverti A, Albuquerque AL, Quaranta M, Albert P, Calverley PM. the effect of posture on asynchronous chest wall movement in COPD. J Appl Physiol 114: 1066-1075, 2013. First published February 14, 2013; doi:10.1152/japplphysiol.00414.2012.-Chronic obstructive pulmonary disease (COPD) patients often show asynchronous movement of the lower rib cage during spontaneous quiet breathing and exercise. We speculated that varying body position from seated to supine would influence rib cage asynchrony by changing the configuration of the respiratory muscles. Twenty-three severe COPD patients (forced expiratory volume in 1 s = 32.5 +/- 7.0% predicted) and 12 healthy age-matched controls were studied. Measurements of the phase shift between upper and lower rib cage and between upper rib cage and abdomen were performed with opto-electronic plethysmography during quiet breathing in the seated and supine position. Changes in diaphragm zone of apposition were measured by ultrasounds. Control subjects showed no compartmental asynchronous movement, whether seated or supine. in 13 COPD patients, rib cage asynchrony was noticed in the seated posture. This asynchrony disappeared in the supine posture. in COPD, upper rib cage and abdomen were synchronous when seated, but a strong asynchrony was found in supine. the relationships between changes in diaphragm zone of apposition and volume variations of chest wall compartments supported these findings. Rib cage paradox was noticed in approximately one-half of the COPD patients while seated, but was not related to impaired diaphragm motion. in the supine posture, the rib cage paradox disappeared, suggesting that, in this posture, diaphragm mechanics improves. in conclusion, changing body position induces important differences in the chest wall behavior in COPD patients.Politecn Milan, Dipartimento Elettron Informaz & Bioingn, I-20133 Milan, ItalyUniversidade Federal de São Paulo, Dept Med, São Paulo, BrazilUniv Liverpool, Univ Hosp Aintree, Ctr Clin Sci, Liverpool L69 3BX, Merseyside, EnglandUniversidade Federal de São Paulo, Dept Med, São Paulo, BrazilWeb of Scienc

    Evaluating the effect of pupil dilation on spectral-domain optical coherence tomography measurements and their quality score

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    BACKGROUND: Spectral-domain optical coherence tomography (SD-OCT) provides fast scan speed and high scan resolution improving its diagnostic accuracy. The purpose of this study was to evaluate if SD-OCT measurements and their quality score are influenced by pupil dilation. METHODS: Retinal nerve fiber layer thickness (RNFL), ganglion cell complex (GCC) and optic nerve head (ONH) were measured in one eye of 57 glaucoma patients and 36 healthy subjects using spectral domain optical coherence tomography (SD-OCT) before and after pupil dilation. Comparisons were made between measurements and their quality score pre- and post dilation (Signal Strength Index, SSI). Overall RNFL, average GCC and ONH rim volume were considered in the analysis. RESULTS: No statistically significant differences were found between pre- and post-dilation measurements in both groups (glaucoma: RNFL 80 ± 15 μm vs 80 ± 16 μm, p = 0.87; GCC 81.35 ± 13.4 μm vs 81.10 ± 13.14 μm, p = 0.92; ONH 0.05 ± 0.11 mm(3) vs 0.04 ± 0.07 mm(3), p = 0.74; controls RNFL 99 ± 12 μm vs 98 ± 14 μm, p = 0.70; GCC 92.12 ± 6.7 μm vs 91.54 ± 7.05 μm, p = 0.72; ONH 0.11 ± 0.1 mm(3) vs 0.04 ± 0.07 mm(3), p = 0.36) nor between pre- and post-dilation quality score (glaucoma SSI RNFL 54.3 ± 10.3 vs 51.7 ± 18.1, p = 0.12; SSI GCC 58 ± 9.5 vs 57 ± 8.09, p = 0.55; SSI ONH 48.5 ± 7.6 vs 46.6 ± 7.2, p = 0.16; controls SSI RNFL 57 ± 10.3 vs 54 ± 9.31, p = 0.2; SSI GCC 60.9 ± 8.1 vs 58.8 ± 7.3, p = 0.3; SSI ONH 51.5 ± 8.9 vs 50.4 ± 8.3, p = 0.59). CONCLUSION: Pupil dilation doesn’t affect SD-OCT measurements and their quality score

    The AGMA1 poly(amidoamine) inhibits the infectivity of herpes simplex virus in cell lines, in human cervicovaginal histocultures, and in vaginally infected mice

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    The development of topical microbicides is a valid approach to protect the genital mucosa from sexually transmitted infections that cannot be contained with effective vaccination, like HSV and HIV infections. A suitable target of microbicides is the interaction between viral proteins and cell surface heparan sulfate proteoglycans (HSPGs). AGMA1 is a prevailingly cationic agmatine-containing polyamidoamine polymer previously shown to inhibit HSPGs dependent viruses, including HSV-1, HSV-2, and HPV-16. The aim of this study was to elucidate the mechanism of action of AGMA1 against HSV infection and assess its antiviral efficacy and biocompatibility in preclinical models. The results show AGMA1 to be a non-toxic inhibitor of HSV infectivity in cell cultures and human cervicovaginal histocultures. Moreover, it significantly reduced the burden of infection of HSV-2 genital infection in mice. The investigation of the mechanism of action revealed that AGMA1 reduces cells susceptibility to virus infection by binding to cell surface HSPGs thereby preventing HSV attachment. This study indicates that AGMA1 is a promising candidate for the development of a topical microbicide to prevent sexually transmitted HSV infections

    Impact of remnant vital tissue after locoregional treatment and liver transplant in hepatocellular cancer patients. A multicentre cohort study

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    The role of pathological findings after locoregional treatments as predictors of hepatocellular cancer recurrence after liver transplantation has been poorly addressed. The aim of the study was to identify the role of remnant vital tissue (RVT) of the target lesion in predicting hepatocellular cancer recurrence. Two hundred and seventy-six patients firstly undergoing locoregional treatment and then transplanted between January 2010 and December 2015 in four European Transplant Centres (i.e. Rome Tor Vergata, Birmingham, Brussels and Ancona) were enrolled in the study to investigate the role of pathological response at upfront locoregional treatment. At multivariable Cox regression analysis, RVT ≥2 cm was a strong independent risk factor for post-LT recurrence (HR = 5.6; P < 0.0001). Five-year disease-free survival rates were 60.8%, 80.9% and 95.0% in patients presenting a RVT ≥2 cm vs. 0.1-1.9 vs. no RVT, respectively. When only Milan Criteria-IN patients were analysed, similar results were reported, with 5-year disease-free survival rates of 58.1%, 79.0% and 94.0% in patients presenting a RVT ≥2 cm vs. 0.1-1.9 vs. no RVT, respectively. RVT is an important determinant of tumour recurrence after liver transplantation performed for hepatocellular cancer. Its discriminative power looks to be evident also in a Milan-IN setting, suggesting to more liberally use locoregional treatments also in these patients

    In children allergic to ragweed pollen, nasal inflammation is not influenced by monosensitization or polysensitization

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    BACKGROUND: In patients polysensitized to pollen allergens, the priming effect, by which the sensitivity of the nasal mucosa to an allergen is increased by the previous exposure to another allergen, is a known phenomenon. This study was aimed at evaluating the degree of nasal inflammation, assessed by nasal cytology, in children with allergic rhinitis (AR) from ragweed pollen according to being monosensitized or polysensitized. METHODS: The study included 47 children. Of them, 24 suffered from AR caused by sensitization to grass pollen and ragweed pollen (group A) and 23 were sensitized only to ragweed pollen (group B). In all patients, the severity of AR was assessed according to the Allergic Rhinitis and Its Impact on Asthma guidelines, and comorbidities were also evaluated. RESULTS: In group A, 16.7% of children had a mild intermittent AR, 4.2% a moderate-to-severe intermittent, 33.3% a mild persistent, and 45.8% a moderate-to-severe persistent; in group B, 26.1% of children had a mild intermittent AR, 0% a moderate-to-severe intermittent, 52.2% a mild persistent, and 21.7% a moderate-to-severe persistent. No significant difference was detected in the number of the considered comorbidities between the two groups. The cell counts of neutrophils, eosinophils, lymphocytes/plasma cells, and mast cells were high but not significantly different in the two groups. CONCLUSION: These findings show that the degree of nasal inflammation found in children with ragweed-induced AR is not influenced by additional allergy to grass pollen and confirm the previously reported absence of priming effect in ragweed allergy

    Biomechanical model and machine learning algorithms comparison for customized training biofeedback on ISS

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    LAUREA MAGISTRALEStato dell'arte e obiettivi L'interesse per l'esplorazione spaziale relativa agli ultimi 60 anni ha dimostrato come l'umanità cerchi sempre di raggiungere l'impossibile. Nonostante lo studio di altri pianeti differenti dalla Terra sembrasse irrealizzabile, oggigiorno la possibilità di raggiungere Marte sta diventando una realtà sempre più concreta. Tuttavia, un progetto così ambizioso è imprescindibilmente legato a spiacevoli svantaggi, in termini di salute e adattamento ad un ambiente in microgravità. Tra tutti gli svantaggi nel vivere in un luogo privo di gravità, potremmo elencare: problemi cardiovascolari, respiratori, visivi e muscolo-scheletrici. Fra questi, ad esempio, molti effetti collaterali riguardano la Sindrome da Adattamento Spaziale, la ventilazione non uniforme, la perfusione irregolare, il decondizionamento muscolare, l'atrofia e la demineralizzazione ossea. Per scopi di ricerca, molti progetti hanno cercato di replicare e studiare le stesse condizioni ambientali trovate dai viaggiatori spaziali. Inizialmente, si pensava che l'immersione in acqua fosse un modello logico per ridurre l'attrazione di gravità sulla massa corporea, ma presto si è rivelata un metodo poco pratico e inefficiente. Il riposo forzato a letto, la cui longevità precede l'esplorazione spaziale, è diventato in seguito un'applicazione pratica per simulare le condizioni di assenza di gravità sulla Terra. Con il progresso dell'Informatica, anche le simulazioni via software (e.g. OpenSim) sono diventate un pilastro fondamentale in questo contesto. Per prevenire il decondizionamento nelle future missioni di lunga durata (LDM), i membri dell'equipaggio seguono perciò uno specifico protocollo di addestramento pre-, durante e post-volo. In effetti, la NASA sta utilizzando la Stazione Spaziale Internazionale (ISS) per ottenere più informazioni riguardo le contromisure fisiologiche da adottare. Sia l'allenamento cardiovascolare sia quello resistivo vengono eseguiti con specifici dispositivi: sono a disposizione un cicloergometro, CEVIS (Cycle Ergometer with Vibration Isolation and Stabilization), ed un treadmill, COLBERT, per il mantenimento della salute del sistema cardio vascolare; l'Advance Resistive Exercise Device (ARED) viene invece utilizzato per prevenire l'atrofia muscolare e la perdita di minerali ossei. ARED simula l'uso di pesi esterni generando un carico costante, che può variare da 0 a 272,5 Kg. Consente inoltre di eseguire fino a 29 esercizi tra cui Normal Stance Squat, Wide Stance Squat e Deadlift. Tale architettura si integra anche con un nuovissimo sistema di acquisizione del movimento (MOCAP), ovvero BTS SMART-DX. Quest'ultimo raccoglierà dati cinematici sulla base di sensori passivi posizionati sul corpo dei cosmonauti. Questa tesi è inserita in entrambi i progetti di ricerca “MARcatori biologici e funzionali per la biomedicina aStronautica di PREcisione - MARS-PRE”, proposti dall'Agenzia Spaziale Italiana (ASI) e “ARED Kinematics – Biomechanical quantification of bone and muscle loading to improve the quality of microgravity countermeasure prescription for resistive exercise”, che coinvolge Agenzia Spaziale Europea (ESA), Neuroengineering and Medical Robotics Laboratory (NearLab) del Politecnico di Milano, Jhonson Space Center (JSC) of National Aeronautics and Space Administration (NASA) e Kayser Italia. Il primo progetto presenta come obbiettivo quello di trovare indicatori biologici e funzionali del danno muscolo-scheletrico, che può verificarsi durante una imprecisa esecuzione della routine di allenamento quotidiana sulla ISS. Quindi, un sistema in tempo reale interagirà e fornirà informazioni/avvisi sull'esecuzione delle prestazioni corrette/non corrette. Il secondo progetto, ARED-K, prevede di migliorare l'efficacia degli allenamenti quotidiani individuali sulla ISS in modo soggetto-specifico, stimando le forze interne in gioco. Per raggiungere questi scopi, è necessaria la raccolta di dati utilizzando un sistema di acquisizione del movimento e piattaforme di forza (pre-, durante e post- volo). Verranno poi condotte delle analisi biomeccaniche e dei confronti statistici tra i risultati ottenuti. Attualmente, dati provenienti da sensori inerziali (collezionati durante gli esercizi eseguiti con ARED) non sono disponibili, ma in compenso vi sono quelli cinematici (ottenuti utilizzando il sistema MOCAP). Per questo motivo, è necessario sviluppare un modello biomeccanico per simulare il posizionamento dei sensori sul corpo ed estrarre dati analoghi. Questo lavoro, perciò, si è quindi concentrato sui seguenti obiettivi: (1) miglioramento di un modello utile per condurre un'analisi biomeccanica del movimento umano in condizioni di microgravità sulla ISS; (2) simulazione di sensori inerziali in diversi punti del corpo, ottenendo perciò segnali di accelerazione relativi a corrette e scorrette esecuzioni di esercizi; (3) la realizzazione di un sistema basato sulla classificazione tramite algoritmi di Machine Learning che interagirà e fornirà informazioni/avvertimenti su performance corrette/non corrette durante la tipica routine di allenamento (e.g., quando si eseguono Normal Squat, Wide Squat e Deadlift), (4) Una volta scelto l'algoritmo di ML più adatto, validazione di un classificatore personalizzato e specifico per soggetto atto a riconoscere esecuzioni di esercizi corrette/non corrette. Simulazione sensori inerziali, dati IMU e protocollo sperimentale OpenSim è il software open-source utilizzato per condurre l'analisi biomeccanica e le simulazioni in microgravità. La piattaforma permette, grazie allo strumento “Analyze”, di simulare il posizionamento dei sensori su specifici punti del corpo. Quest’ultimi sono: sterno, sacro, coscia superiore destra, coscia superiore sinistra, stinco superiore destro e stinco superiore sinistro. In questo modo, è possibile estrarre i dati di accelerazione simulati. Il modello muscolo-scheletrico generalmente utilizzato per le attività di cammino e corsa è il "Gait2392", ma non è adatto ad esercizi quali lo squat profondo. In letteratura, il modello “Catelli” (già validato) ha dimostrato di aumentare i ROM articolari, soprattutto quelli relativi alla articolazione del ginocchio, permettendo così di sfruttarlo per i movimenti considerati in questo progetto di tesi. In particolare, questo modello è stato validato specificatamente per esercizi di Squat, i quali richiedono ROM più elevati per l'articolazione del ginocchio, differentemente dal cammino e dalla corsa. Abbiamo anche deciso di verificarne la validazione, ottenendo esito positivo e conforme a quanto esposto nel paper di ricerca. Per raggiungere tale obbiettivo, sono stati considerati dati simulati provenienti da 6 soggetti reclutati al NASA JSC (3 Uomini, Media: 32.33 ± 3.06 età, 79.96 ± 10.84 kg, 174.67 ± 8,50 cm altezza; 3 Donne, Media: 31.33 ± 6.80 età, 60.20 ± 7.56 kg, 161.83 ± 7.21 cm altezza), i quali hanno eseguito 4 ripetizioni per ogni tipologia di movimento (Nromal Squat, Wide Squat e Deadlift) usando ARED. Per quanto concerne le accelerazioni reali acquisite mediante sensori IMU, invece, abbiamo cominciato ad analizzare dati grezzi (raccolti a Pavia) di un altro progetto di tesi svolto in parallelo a questo ed inserito nella ricerca MARS-PRE. Dal lavoro di Ravizza et al. (2020), nessuna differenza statistica è stata osservata tra la cinematica degli esercizi eseguiti con ARED e quelli condotti con bilanciere. Di conseguenza, questo progetto di tesi si è basato su tale consapevolezza per condurre lo step relativo alle acquisizioni. Il sistema elettronico utilizzato (marca XSENS) per collezionare i dati di accelerazione è composto da 6 differenti accelerometri posti in differenti parti del corpo umano (1 su ogni coscia, 1 su ogni polpaccio, 1 sullo sterno. 1 sul sacro). Sono stati coinvolti solo 17 soggetti (9 Uomini, Media: 26.89 ± 5.73 età, 64.22 ± 7.14 kg, 173.44 ± 4.25 cm altezza; 8 Donne, Media: 25.38 ± 3.77 età, 56 ± 6.31 kg, 163.14 ± 6.52 cm altezza). Questi hanno eseguito un numero diverso di ripetizioni (il range varia da 5 a 20, in base alle loro capacità fisiche) di Normal Squat, Wide Squat e Deadlift (analogamente a quelli eseguiti al NASA JSC) usando bilanciere e pesi (con carico nel range 50-75% di ISO-MAX). I dati in questione non si riferiscono semplicemente alla corretta esecuzione degli esercizi, ma anche ad un dataset di allenamenti scorretti (evitando sempre di danneggiare in modo permanente o temporaneo le strutture fisiologiche dei soggetti reclutati), i quali sono stati approvati dagli specialisti della NASA JSC e dal Comitato Etico del Politecnico di Milano. Elaborazione dati e sviluppo classificatore Matlab R2019b è stato in seguito adoperato per pre-elaborare i dati IMU di accelerazione. I dati grezzi sono stati inizialmente filtrati con un filtro Butterworth passa basso di sesto ordine, con una frequenza di taglio di 5 Hz. Dopo la rimozione di outlier e la considerazione di soli dati significativi, ogni singola ripetizione degli esercizi è stata isolata e ridimensionata a un valore di tempo medio. Questi passaggi consentono un utilizzo più rapido per la sezione successiva: Google Colab (basato su script python) è stata scelta come piattaforma candidata per normalizzare, applicare un algoritmo in grado di risolvere problemi di classificazione sbilanciati e, infine, per eseguire estrazione e selezione delle feature (PCA). Quest'ultimo step consente di ridurre il set delle feature ed è stato applicato a tutti gli algoritmi esplorati in questo studio (e.g., SVM, KNN, Decision Tree, XGBoost, MLP) ad eccezione della Convolutional Neural Network (CNN), che ha semplicemente utilizzato i dati pre-elaborati. Tutti gli approcci di apprendimento supervisionato sono stati poi sviluppati e testati per eseguire una classificazione multi-label, al fine di discriminare esercizi corretti e scorretti (rispettivamente 5 e 3 movimenti imprecisi sono stati classificati per Normal/Wide Squat e Deadlift). Risultati e conclusioni Modello biomeccanico idoneo agli esercizi dell’allenamento sulla ISS - Il modello biomeccanico OpenSim “Catelli”, a differenza di “gait2392”, si è dimostrato un valido candidato nel progetto di ricerca ARED-K in quanto permette di raggiungere quei Range di Movimento articolari (ROM), in particolare per la articolazione del ginocchio, adatti per gli esercizi specifici di allenamento (Normal Squat, Wide Squat, Deadlift) sulla ISS. Classificazione delle prestazioni in base ai segnali di accelerazione - Il set di dati originale, contenente 1314 feature per sei sensori (quindi 219 feature per ognuno), viene ridotto con la PCA a 198, 216 e 152 feature, rispettivamente per Normal Squat, Wide Squat e Deadlift (descrivendo così per ognuno almeno il 90% della varianza dei dati). SVM e CNN hanno permesso, rispettivamente, di raggiungere risultati ammissibili e affidabili in termini di accuratezza: 87.79% e 84.30% per il Normal Squat; 86.38% e 86.91% per il Wide Squat; 83.76% e 82.05% per il Deadlift. Sono necessarie ulteriori indagini per ampliare il dataset e perfezionare il classificatore, ma questi risultati preliminari potrebbero essere visti come un incentivo a considerare tale approccio una soluzione tangibile. Crediamo fermamente che ampliando la quantità di dati di accelerazione a disposizione, la CNN assumerà un ruolo chiave per un biofeedback in tempo reale sulla ISS. Utilizzando reti neurali convoluzionali, sono stati testati inoltre diversi output provenienti da svariate combinazioni di sensori. Risultati accettabili sono stati raggiunti anche con sensori posti in posizione omolaterale (in particolare, relativi ai punti del corpo dell'osso sacro, della coscia sinistra, dello stinco sinistro e dello sterno). Comunque, l’obbiettivo finale riguarda l’introduzione di un set-up composto da sensori inerziali IMU utilizzabili in combinazione con ARED. In tale scenario, la soluzione omolaterale è sconsigliata in quanto l'asimmetria comporterebbe l'esclusione dei feedback relativi ad un lato del corpo (sinistro o destro, a seconda del posizionamento dei sensori). Inoltre, usando la CNN, sono stati osservati risultati discreti in termini di accuratezza considerando sensori IMU posti sugli arti inferiori (84.29% per NS, 81.68% per WS e 76.92% per DL). Poiché la personalizzazione è uno degli obiettivi del progetto MARS-PRE, tre soggetti (fra i 17 disponibili) che hanno eseguito il maggior numero di ripetizioni sono stati isolati e studiati separatamente. Pertanto, gli algoritmi di ML precedentemente citati sono stati utilizzati per costruire un classificatore personalizzato adatto a una singola persona e buoni risultati di accuratezza sono stati ottenuti (3 Donne, Media: 25.00 ± 3.61 età, 58.00 ± 6.08 kg, 166.33 ± 3.21 cm altezza. Media di accuratezza per SVM e CNN, rispettivamente: 98.61% ± 2.41% e 95.83% ± 4.17% per NS; 98.61% ± 2.41% e 87.5% ± 4.17% per WS; 91.67% ± 3.61% e 87.5% ± 10.83% per DL). Inoltre, i dati IMU e quelli simulati mostrano differenze visibili: addestrare algoritmi di machine learning con il primo e testare con il secondo (e viceversa) non è un approccio affidabile. Di conseguenza, le fasi di training e test sono state condotte solo sulle accelerazioni simulate (con risultati di accuratezza discreti sia per SVM sia per CNN: 90.00% e 80.00% per il Normal Squat; 85.71% e 71.43 % per il Wide Squat; 75.00% e 75.00% per il Deadlift), ma il numero di osservazioni (in totale circa 30 ripetizioni per ogni tipologia di esercizio) è troppo basso, specialmente per la rete neurale. Sfortunatamente, la diffusione del virus Covid-19 ha imposto rigide costrizioni escludendo così la possibilità di espandere il dataset sia relativo ai sensori inerziali sia a quello dei dati simulati. Struttura della tesi Il presente lavoro è strutturato come segue: • Capitolo 1: descrizione degli adattamenti fisiologici che si verificano durante le missioni spaziali; revisione e stato dell'arte delle contromisure e dei sistemi di motion capture utilizzati sulla ISS. • Capitolo 2: scopo della tesi. • Capitolo 3: descrizione del software utilizzato per la modellazione biomeccanica e per condurre le simulazioni. • Capitolo 4: descrizione del set-up adottato per la raccolta dei dati e loro successiva elaborazione; sviluppo e validazione di un classificatore multi-label. • Capitolo 5: risultati e discussioni. • Capitolo 6: conclusioni e sviluppi futuri. • Appendice A. • Appendice B.State of art and aims The interest in space exploration of the past 60 years has proven how humanity always tries to reach the impossible. Even though studying another planet different from Earth seemed unfeasible, nowadays the possibility of landing on Mars is becoming a concrete reality. However, such ambitious project comes together with unpleasant downsides, in terms of human’s health and adaptation in a microgravity environment. Of all the drawbacks while living in a place lacking gravity, we could list cardiovascular, respiratory, visual and musculoskeletal issues. Among these, for instance, many side effects regard Space Adaptation Syndrome, uneven ventilation, irregular perfusion, muscle deconditioning, atrophy and bone demineralization. For research purposes, a lot of projects tried to replicate and study the same specific environmental conditions found by the space travelers. Initially, the immersion in water was thought to be a logical model for reducing the pull of gravity on the body mass, but it soon resulted an impractical and inefficient method. Bed rest, whose longevity predates space exploration, later became a practical application to simulate the weightlessness conditions on ground. With the progress of Computer Science, also simulations via software (e.g., OpenSim) became a fundamental pillar in this context. To prevent deconditioning in future long-duration missions (LDMs), crewmembers still follow a specific training protocol pre-, in- and post-flight. Indeed, NASA is using the International Space Station (ISS) to learn more about physiological countermeasures. Both cardiovascular and resistive training are performed with specific exercise devices: CEVIS (Cycle Ergometer with Vibration Isolation and Stabilization) and treadmill COLBERT are exploited for cardiovascular system health; the Advance Resistive Exercise Device (ARED) is used, instead, to prevent muscle atrophy and bone mineral loss. It simulates the use of free weights in microgravity by generating a constant load, which can be changed from 0 to 272.5 Kg. ARED allows to carry out up to 29 exercises including Normal Stance Squat, Wide Stance Squat and Deadlift. This mechanical architecture is also combined with a brand-new motion capture system (MOCAP), namely BTS SMART-DX. The latter is going to collect kinematic data basing on passive markers placed on the cosmonauts’ body. This thesis is inserted in both research projects “MARcatori biologici e funzionali per la biomedicina aStronautica di PREcisione – MARS-PRE”, proposed by Italian Space Agency (ASI) and “ARED Kinematics – Biomechanical quantification of bone and muscle loading to improve the quality of microgravity countermeasure prescription for resistive exercise”, which involves European Space Agency (ESA), Neuroengineering and Medical Robotics Laboratory (NearLab) of Politecnico di Milano, Johnson Space Center (JSC) of National Aeronautics and Space Administration (NASA) and Kayser Italia. The first project aims to find biological and functional anticipatory makers of musculo-skeletal damage, which can occur while performing inaccurately the daily workout routine on ISS. Then, a real time system will interact and provide information/warnings on correct/incorrect performance execution. The second project, ARED-K, plans on improving the subject specific effectiveness of daily exercises on flight by estimating internal body loads. To reach these purposes, data collection using motion capture system and force plates during pre-, in- and post-flight is needed, as well as biomechanical analysis and statistical comparison of data collected. Currently, no inertial sensor data of exercises performed with ARED are available, but only kinematic ones (obtained by using the MOCAP system). For this reason, a biomechanical model is needed to simulate sensors placement on body and extract analogues data. The present work hence focused on the following aims: (1) improvement of a model useful to conduct a biomechanical analysis of the human motion in microgravity conditions on ISS; (2) simulation of inertial sensors in different body points, thus obtaining acceleration signals related to correct and incorrect exercise executions; (3) the realization of a system based on machine learning classification that will interact and provide information/warnings on correct/incorrect performance during typical workout routine (e.g. when performing Normal Squat, Wide Squat and Deadlift); (4) Once chosen the most suitable ML algorithm, validation of a customized and subject-specific classifier to recognize correct/incorrect exercise executions. Inertial sensors simulation, IMU data and experimental protocol OpenSim is the open-source software exploited to conduct the biomechanical analysis and the microgravity simulations. The platform allows, through to the “Analyze” tool, to simulate sensors placement on specific body points. The body points chosen were Sternum, Sacrum, Right Upper Thigh, Left Upper Thigh, Right Upper Shank and Left Upper Shank. In this way, simulated acceleration data can be extracted. The musculoskeletal model generally used for gait and running tasks is “Gait2392” but is not suitable for deep squatting exercises. In literature, the already validated “Catelli” model demonstrated to increase the ROMs especially for the knee joint, thus implying its usability for the motions considered in the current project. In particular, this model has been validated specifically for Squat exercises, which require higher ROMs for the knee joint with respect to gait and running. We also decided to verify the “Catelli” model validation of the research paper, successfully. To reach this purpose, we considered the simulated data coming from 6 subjects (3 Males, Mean: 32.33 ± 3.06 years old, 79.96 ± 10.84 kg, 174.67 ± 8,50 cm height; 3 Females, Mean: 31.33 ± 6.80 years old, 60.20 ± 7.56 kg, 161.83 ± 7.21 cm height) recruited at NASA JSC who performed 4 repetitions for each movement (Normal Squat, Wide Squat and Deadlift) using ARED. As regards the real accelerations acquired through IMU sensors, instead, we started from the raw data (collected in Pavia) of another parallel thesis project inserted in the MARS-PRE research. From the work of Ravizza et al. (2020), no statistical differences are observed between kinematics of exercises performed with ARED and barbell. Consequently, the current thesis project relied on this pillar to conduct the acquisition step. The Electronic system used is made up of 6 different accelerometers (XSENS) placed in specific human body locations (1 on each thigh, 1 on each shank, 1 on sternum and 1 on sacrum). Only 17 subjects were involved (9 Males, Mean: 26.89 ± 5.73 years old, 64.22 ± 7.14 kg, 173.44 ± 4.25 cm height; 8 Females, Mean: 25.38 ± 3.77 years old, 56 ± 6.31 kg, 163,14 ± 6.52 cm height). They performed a different number of repetitions (the range varies from 5 to 20, according to their physical capabilities) of Normal Squat, Wide Squat and Deadlift (similarly to those executed at NASA JSC) using barbell and weights (load within 50-75% of ISO-MAX). These collected data were not simply referred to correct exercise execution, but also to a dat

    Long-term lithium treatment in bipolar disorder. effects on glomerular filtration rate and other metabolic parameters

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    .BACKGROUND: Concerns about potential adverse effects of long-term exposure to lithium as a mood-stabilizing treatment notably include altered renal function. However, the incidence of severe renal dysfunction; rate of decline over time; effects of lithium dose, serum concentration, and duration of treatment; relative effects of lithium exposure vs. aging; and contributions of sex and other factors all remain unclear. METHODS: Accordingly, we acquired data from 12 collaborating international sites and 312 bipolar disorder patients (6142 person-years, 2669 assays) treated with lithium carbonate for 8-48 (mean 18) years and aged 20-89 (mean 56) years. We evaluated changes of estimated glomerular filtration rate (eGFR) as well as serum creatinine, urea-nitrogen, and glucose concentrations, white blood cell count, and body-mass index, and tested associations of eGFR with selected factors, using standard bivariate contrasts and regression modeling. RESULTS: Overall, 29.5% of subjects experienced at least one low value of eGFR ( 55; risk of ≥2 low values was 18.1%; none experienced end-stage renal failure. eGFR declined by 0.71%/year of age and 0.92%/year of treatment, both by 19% more among women than men. Mean serum creatinine increased from 0.87 to 1.17 mg/dL, BUN from 23.7 to 33.1 mg/dL, glucose from 88 to 122 mg/dL, and BMI from 25.9 to 26.6 kg/m2. By multivariate regression, risk factors for declining eGFR ranked: longer lithium treatment, lower lithium dose, higher serum lithium concentration, older age, and medical comorbidity. Later low eGFR was also predicted by lower initial eGFR, and starting lithium at age ≥ 40 years. LIMITATIONS: Control data for age-matched subjects not exposed to lithium were lacking. CONCLUSIONS: Long-term lithium treatment was associated with gradual decline of renal functioning (eGFR) by about 30% more than that was associated with aging alone. Risk of subnormal eGFR was from 18.1% (≥2 low values) to 29.5% (≥1 low value), requiring about 30 years of exposure. Additional risk factors for low eGFR were higher serum lithium level, longer lithium treatment, lower initial eGFR, and medical comorbidity, as well as older age

    Co-Transplantation of endothelial progenitor cells and pancreatic islets to induce long-lasting normoglycemia in streptozotocin-treated diabetic rats

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    Graft vascularization is a crucial step to obtain stable normoglycemia in pancreatic islet transplantation. Endothelial progenitor cells (EPCs) contribute to neoangiogenesis and to the revascularization process during ischaemic events and play a key role in the response to pancreatic islet injury. In this work we co-transplanted EPCs and islets in the portal vein of chemically-induced diabetic rats to restore islet vascularization and to improve graft survival. Syngenic islets were transplanted, either alone or with EPCs derived from green fluorescent protein (GFP) transgenic rats, into the portal vein of streptozotocin-induced diabetic rats. Blood glucose levels were monitored and intraperitoneal glucose tolerance tests were performed. Real time-PCR was carried out to evaluate the gene expression of angiogenic factors. Diabetic-induced rats showed long-lasting (6 months) normoglycemia upon co-transplantation of syngenic islets and EPCs. After 3–5 days from transplantation, hyperglycaemic levels dropped to normal values and lasted unmodified as long as they were checked. Further, glucose tolerance tests revealed the animals' ability to produce insulin on-demand as indexed by a prompt response in blood glucose clearance. Graft neovascularization was evaluated by immunohistochemistry: for the first time the measure of endothelial thickness revealed a donor-EPC-related neovascularization supporting viable islets up to six months after transplant. Our results highlight the importance of a newly formed viable vascular network together with pancreatic islets to provide de novo adequate supply in order to obtain enduring normoglycemia and prevent diabetes-related long-term health hazards

    Beyond the MSW effect: Neutrinos in a dense medium

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    We present a theory of neutrino oscillations in a dense medium which goes beyond the effective matter potential used in the description of the MSW effect. We show how the purity of the neutrino state is degraded by neutrino interactions with the environment and how neutrino--matter interactions can be a source of decoherence. We present new oscillation formulae for neutrinos interacting with leptons and carry out a numerical analysis which exhibits deviations from the MSW formulae for propagation through the Earth of ultra-high energy neutrinos. In particular, we show that at high density and/or high neutrino energy, the vanishing transition probabilities derived for MSW effect, are non zero when the scattering is taken into account.Comment: 15 pages, 4 figure
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