Model-based fault diagnosis in PEM fuel cell systems

CONAPPICE 2008, Zaragoza, Spain, 24-26 September 2008.In this work, a model-based fault diagnosis methodology for PEM fuel cell systems is presented. The methodology is based on computing residuals, indicators that are obtained comparing measured inputs and outputs with analytical relationships, which are obtained by system modelling. The innovation of this methodology is based on the characterization of the relative residual fault sensitivity. To illustrate the results, a non-linear fuel cell simulator proposed in the literature is used, with modifications, to include a set of fault scenarios proposed in this work. Finally, it is presented the diagnosis results corresponding to these fault scenarios. It is remarkable that with this methodology it is possible to diagnose and isolate all the faults in the proposed set in contrast with other well known methodologies which use the binary signature matrix of analytical residuals and faults.This work was supported by the project 'Avances en el modelo y diseño de controladores para sistemas basados en pila de combustible PEM' (4800). This work has been partially financed by the Research Commission of the Generalitat of Catalunya (Grup SAC ref. 2005SGR00537) and by Spanish Ministry of Education (CICYT projects ref. DPI-2005-05415 and ref. DPI2007-62966) and with the support of the Departamento de Universidades, Investigación y Sociedad de la Información y del Consejo Nacional de Ciencia y Tecnología (CONACYT).Peer Reviewe

Association between maximum tongue pressure and swallowing safety and efficacy in amyotrophic lateral sclerosis

Background Oropharyngeal dysphagia (OD) is common in amyotrophic lateral sclerosis (ALS), leading to a reduction of swallowing safety and efficacy. The tongue has an important role in swallowing function for oral processing and bolus propulsion through the pharynx. The study aims to analyze the association between instrumental findings of OD and tongue pressure. Methods Patients with ALS referred for fiberoptic endoscopic evaluation of swallowing (FEES) were recruited. FEES was conducted to test swallowing function with liquid (5, 10, and 20 ml), semisolid (5, 10, and 20 ml), and solid. FEES recordings were assessed for swallowing safety, using the penetration-aspiration scale (PAS), and for swallowing efficacy, using the Yale Pharyngeal Residue Severity Rating Scale (YPRSRS). PAS scores >2 were suggestive of penetration, PAS scores >5 of aspiration, and YPRSRS scores >2 of residue. Maximum tongue pressure (MTP) and tongue endurance were measured using the Iowa Oral Performance Instrument. Tongue pressure measurements were compared between patients with and without penetration, aspiration, or residue. Key results Fifty-five patients with ALS were included. Mean MTP was 29.7 kPa, and median tongue endurance was 10 seconds. Patients with residue in the pyriform sinus had a significantly lower MTP than patients without residue in the pyriform sinus with semisolids 10 ml (P = .011) and 20 ml (P = .032). Patients with a tongue endurance <10 seconds exhibited higher frequency of penetration with liquids 5 ml (P = .046), liquids 10 ml (P = .015), and solids (P = .22). Conclusion and inferences In patients with ALS, MTP is significantly associated with an impairment of swallowing efficacy and tongue endurance was significantly associated with an impairment of swallowing safety

The importance of meal assessment in ALS patients

Background: the importance of instrumental evaluation of swallowing in ALS patients is highly recognized in order to assess swallowing safety and prevent pulmonary complications. However, swallowing performance during instrumental assessment may not be representative of what happens when consuming meals in everyday life. Indeed, as fatigue is a common feature in ALS patients, swallowing efficacy may progressively decline during mealtime consumption and food and liquid oral intake may not be sufficient. Objectives: to investigate the relationship between the performance during mealtime consumption and the efficacy of oral and pharyngeal phase of swallowing in ALS patients. Methods: thirteen ALS patients, 7 males and 6 females with a median age of 68.5 years (range 51-78) were enrolled in the study. Fiberoptic endoscopic evaluation of swallowing (FEES) was conducted testing liquids, semisolids and, whether possible, solids. The Penetration-Aspiration Scale (PAS) and the Dysphagia Outcome and Severity Scale (DOSS) were used to assess the FEES. The Test of Mastication and Swallowing Solids (TOMASS) was performed. Tongue strength and resistance were assessed through the Iowa Oral Performance Instrument (IOPI). Patients completed the Eating Assessment Tool-10, a self-reported questionnaire. Typical oral intake was recorded using the Functional Oral Intake Scale (FOIS). Meal consumption was observed and scored through the Mealtime Assessment Scale (MAS); the time the patients needed to consume a meal was recorded. Correlations between MAS total score or time and PAS, DOSS, EAT-10, FOIS, TOMASS and IOPI measures were studied using Spearman\u2019s correlation coefficient. Results: a statistically significant correlation was found between MAS total scores and FOIS (r=0.755, p=0.007), EAT-10 (r=-0.724, p=0.012), tongue strength (r=0.718, p=0.019) and TOMASS total time (r=-0.709, p=0.046). Time needed to consume a meal significantly correlated with tongue resistance (r=0.675, p=0.032) and number of discrete bites during TOMASS (r=-0.793, p=0.033). No statistically significant correlations were found between MAS and PAS or DOSS. Discussion and conclusion: these preliminary results suggest that instrumental assessment of swallowing, especially FEES, may not be exhaustive in ALS patients as it does not predict patient\u2019s performance during meals. Efficacy of swallowing oral phase seems to be related to meal consumption more than pharyngeal phase. Therefore, our data stress the need of a comprehensive swallowing evaluation in ALS patients, including instrumental, oral phase and mealtime assessment, in order to estimate the risk of both pulmonary and nutritional complications related to dysphagia

The importance of meal assessment in ALS patients

Background: the importance of instrumental evaluation of swallowing in ALS patients is highly recognized in order to assess swallowing safety and prevent pulmonary complications. However, swallowing performance during instrumental assessment may not be representative of what happens when consuming meals in everyday life. Indeed, as fatigue is a common feature in ALS patients, swallowing efficacy may progressively decline during mealtime consumption and food and liquid oral intake may not be sufficient. Objectives: to investigate the relationship between the performance during mealtime consumption and the efficacy of oral and pharyngeal phase of swallowing in ALS patients. Methods: thirteen ALS patients, 7 males and 6 females with a median age of 68.5 years (range 51-78) were enrolled in the study. Fiberoptic endoscopic evaluation of swallowing (FEES) was conducted testing liquids, semisolids and, whether possible, solids. The Penetration-Aspiration Scale (PAS) and the Dysphagia Outcome and Severity Scale (DOSS) were used to assess the FEES. The Test of Mastication and Swallowing Solids (TOMASS) was performed. Tongue strength and resistance were assessed through the Iowa Oral Performance Instrument (IOPI). Patients completed the Eating Assessment Tool-10, a self-reported questionnaire. Typical oral intake was recorded using the Functional Oral Intake Scale (FOIS). Meal consumption was observed and scored through the Mealtime Assessment Scale (MAS); the time the patients needed to consume a meal was recorded. Correlations between MAS total score or time and PAS, DOSS, EAT-10, FOIS, TOMASS and IOPI measures were studied using Spearman\u2019s correlation coefficient. Results: a statistically significant correlation was found between MAS total scores and FOIS (r=0.755, p=0.007), EAT-10 (r=-0.724, p=0.012), tongue strength (r=0.718, p=0.019) and TOMASS total time (r=-0.709, p=0.046). Time needed to consume a meal significantly correlated with tongue resistance (r=0.675, p=0.032) and number of discrete bites during TOMASS (r=-0.793, p=0.033). No statistically significant correlations were found between MAS and PAS or DOSS. Discussion and conclusion: these preliminary results suggest that instrumental assessment of swallowing, especially FEES, may not be exhaustive in ALS patients as it does not predict patient\u2019s performance during meals. Efficacy of swallowing oral phase seems to be related to meal consumption more than pharyngeal phase. Therefore, our data stress the need of a comprehensive swallowing evaluation in ALS patients, including instrumental, oral phase and mealtime assessment, in order to estimate the risk of both pulmonary and nutritional complications related to dysphagia

Valutazione del rischio elettromagnetico ai sensi del D.Lgs. 81/2008 presso l\u27Azienda Ospedaliera Mellino Mellini Chiari (Brescia)

.La relazione riferisce i risultati della campagna di misura effettuata nei giorni dal 6 al 9 giugno 2011 e successivamente il 4 e il 6 luglio 2011. La campagna ? stata preceduta da un sopralluogo (21 marzo 2011) alle strutture di competenza dell\u27Azienda Mellino Mellini (Chiari, Iseo, Rovato, Palazzolo ed Orzinuovi) per la definizione delle azioni da intraprendere per la valutazione del rischio elettromagnetico in conformit? al D.Lgs. 81/2008. Pi? specificatamente gli obiettivi della campagna di misura sono stati i seguenti. Misura dei campi elettromagnetici (EM) in punti predefiniti per la determinazione dei livelli di campo EM presenti. Determinazione dei campi elettrici, magnetici ed elettromagnetici emessi da apparecchiature elettromedicali quali magnetoterapia e radarterapia . Misura dei campi magnetici (in particolare induzione magnetica) presenti nei locali tecnici quali cabina elettrica e impianti di condizionamento. Valutazione dell\u27intensit? dell\u27induzione magnetica all\u27interno e in prossimit? di incubatrici e culle termiche (Chiari e Iseo). Valutazione delle specifiche tecniche di elettrobisturi (Blocco Operatorio di Iseo). Caratterizzazione della presenza di eventuali interferenze EM dovute alla rete wireless (reparto di terapia intensiva di cardiologia di Chiari) o da disturbi EM presenti su apparecchiature per diagnostica (neurologia di Chiari)

Total synthesis, isolation, surfactant properties, and biological evaluation of ananatosides and related macrodilactone-containing rhamnolipids

Rhamnolipids are a specific class of microbial surfactants, which hold great biotechnological and therapeutic potential. However, their exploitation at the industrial level is hampered because they are mainly produced by the opportunistic pathogenPseudomonas aeruginosa. The non-human pathogenic bacteriumPantoea ananatisis an alternative producer of rhamnolipid-like metabolites containing glucose instead of rhamnose residues. Herein, we present the isolation, structural characterization, and total synthesis of ananatoside A, a 15-membered macrodilactone-containing glucolipid, and ananatoside B, its open-chain congener, from organic extracts ofP. ananatis. Ananatoside A was synthesized through three alternative pathways involving either an intramolecular glycosylation, a chemical macrolactonization or a direct enzymatic transformation from ananatoside B. A series of diasteroisomerically pure (1→2), (1→3), and (1→4)-macrolactonized rhamnolipids were also synthesized through intramolecular glycosylation and their anomeric configurations as well as ring conformations were solved using molecular modeling in tandem with NMR studies. We show that ananatoside B is a more potent surfactant than its macrolide counterpart. We present evidence that macrolactonization of rhamnolipids enhances their cytotoxic and hemolytic potential, pointing towards a mechanism involving the formation of pores into the lipidic cell membrane. Lastly, we demonstrate that ananatoside A and ananatoside B as well as synthetic macrolactonized rhamnolipids can be perceived by the plant immune system, and that this sensing is more pronounced for a macrolide featuring a rhamnose moiety in its native1C4conformation. Altogether our results suggest that macrolactonization of glycolipids can dramatically interfere with their surfactant properties and biological activity

Histopathological patterns of the liver involvement in visceral leishmaniasis

The hepatic changes observed in liver specimen from either biopsy or necropsy of 47 patients with visceral leishmaniasis permited us to define three different histopathological patterns of involvement: typical, nodular, and fibrogenic. These patterns seem to be representative of different evolutive stages of the hepatic involvement in the disease either towards a more benign evolution or to more chronic stage with fibrosis and "cirrhosis". These histopathological evolutive stages are related to the prognosis of the disease