48 research outputs found

    Leakage isolation using pressure sensitivity analysis in water distribution networks: Application to the Barcelona case study

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    Leaks are present to some extent in all water-distribution systems. This paper proposes a leakage localisation method based on the pressure measurements and pressure sensitivity analysis of nodes in a network. The sensitivity analysis using analytical tools is not a trivial job in a real network because the huge non-explicit non-lĂ­near systems of equation that describe its dynamics. Simulations of the network in presence and absence of leakage may provide an approximation of this sensitivity. This matrix is binarised using a threshold independent of the node. The binary matrix is assumed as a signature matrix for leakages. However, there is a trade-off between the resolution of the leakage isolation procedure and the number of available pressure sensors. In order to maximise the isolability with a reasonable number of sensors, an optimal sensor placement methodology, based on genetic algorithms, is also proposed. This methodology has been developed for Barcelona Network using Piccolo simulator. The sensor placement and the leakage detection and localization methodologies are applied to district management areas (DMA).Peer ReviewedPostprint (published version

    hCOA3 stabilizes COX1 and promotes cytochrome c oxidase assembly in human mitochondria

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    Cytochrome c oxidase (COX) or complex IV of the mitochondrial respiratory chain plays a fundamental role in energy production of aerobic cells. In humans, COX deficiency is the most frequent cause of mitochondrial encephalomyopathies. Human COX is composed of 13 subunits of dual genetic origin, whose assembly requires an increasing number of nuclear-encoded accessory proteins known as assembly factors. Here, we have identified and characterized human CCDC56, an 11.7-kDa mitochondrial transmembrane protein, as a new factor essential for COX biogenesis. CCDC56 shares sequence similarity with the yeast COX assembly factor Coa3 and was termed hCOA3. hCOA3-silenced cells display a severe COX functional alteration owing to a decreased stability of newly synthesized COX1 and an impairment in the holoenzyme assembly process. We show that hCOA3 physically interacts with both the mitochondrial translation machinery and COX structural subunits. We conclude that hCOA3 stabilizes COX1 co-translationally and promotes its assembly with COX partner subunits. Finally, our results identify hCOA3 as a new candidate when screening for genes responsible for mitochondrial diseases associated with COX deficiency

    Endoplasmic reticulum stress inhibition protects steatotic and non-steatotic livers in partial hepatectomy under ischemia-reperfusion

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    During partial hepatectomy, ischemia-reperfusion (I/R) is commonly applied in clinical practice to reduce blood flow. Steatotic livers show impaired regenerative response and reduced tolerance to hepatic injury. We examined the effects of tauroursodeoxycholic acid (TUDCA) and 4-phenyl butyric acid (PBA) in steatotic and non-steatotic livers during partial hepatectomy under I/R (PH + I/R). Their effects on the induction of unfolded protein response (UPR) and endoplasmic reticulum (ER) stress were also evaluated. We report that PBA, and especially TUDCA, reduced inflammation, apoptosis and necrosis, and improved liver regeneration in both liver types. Both compounds, especially TUDCA, protected both liver types against ER damage, as they reduced the activation of two of the three pathways of UPR (namely inositol-requiring enzyme and PKR-like ER kinase) and their target molecules caspase 12, c-Jun N-terminal kinase and C/EBP homologous protein-10. Only TUDCA, possibly mediated by extracellular signal-regulated kinase upregulation, inactivated glycogen synthase kinase-3ÎČ. This is turn, inactivated mitochondrial voltage-dependent anion channel, reduced cytochrome c release from the mitochondria and caspase 9 activation and protected both liver types against mitochondrial damage. These findings indicate that chemical chaperones, especially TUDCA, could protect steatotic and non-steatotic livers against injury and regeneration failure after PH + I/R. © 2010 Macmillan Publishers Limited.This work was supported by the Ministerio de EducaciĂłn y Ciencia (project grant SAF 2005-00385; project grant manager BFU2009-07410) (Madrid, Spain) and the Ministerio de Sanidad y Consumo (project grant PIO60021) (Madrid, Spain). Centro de Investigaciones BiomĂ©dicas Esther Koplowitz, Centro de InvestigaciĂłn BiomĂ©dica en Red de Enfermedades HepĂĄticas y Digestivas is supported by the Instituto de Salud Carlos III (Spain).Peer Reviewe

    Retinol binding protein 4 and retinol in steatotic and nonsteatotic rat livers in the setting of partial hepatectomy under ischemia/reperfusion

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    Steatotic livers show increased hepatic damage and impaired regeneration after partial hepatectomy (PH) under ischemia/reperfusion (I/R), which is commonly applied in clinical practice to reduce bleeding. The known function of retinol-binding protein 4 (RBP4) is to transport retinol in the circulation. We examined whether modulating RBP4 and/or retinol could protect steatotic and nonsteatotic livers in the setting of PH under I/R. Steatotic and nonsteatotic livers from Zucker rats were subjected to PH (70%) with 60 minutes of ischemia. RBP4 and retinol levels were measured and altered pharmacologically, and their effects on hepatic damage and regeneration were studied after reperfusion. Decreased RBP4 levels were observed in both liver types, whereas retinol levels were reduced only in steatotic livers. RBP4 administration exacerbated the negative consequences of liver surgery with respect to damage and liver regeneration in both liver types. RBP4 affected the mobilization of retinol from steatotic livers, and this revealed actions of RBP4 independent of simple retinol transport. The injurious effects of RBP4 were not due to changes in retinol levels. Treatment with retinol was effective only for steatotic livers. Indeed, retinol increased hepatic injury and impaired liver regeneration in nonsteatotic livers. In steatotic livers, retinol reduced damage and improved regeneration after surgery. These benefits of retinol were associated with a reduced accumulation of hepatocellular fat. Thus, strategies based on modulating RBP4 could be ineffective and possibly even harmful in both liver types in the setting of PH under I/R. In terms of clinical applications, a retinol pretreatment might open new avenues for liver surgery that specifically benefit the steatotic liver. Liver Transpl 18:1198-1208, 2012. (c) 2012 AASLD.Spanish Ministry of Science and Innovation [BFU2009-07410]Agency for the Innovation and Internationalization of Catalan Enterprise [VALTEC08-2-0033]Agency for the Support and Evaluation of Graduate Education (Brazilian Ministry of Education)Spanish Society for Liver Transplantation Foundatio

    L’excĂ©s de mortalitat a Catalunya: anĂ lisi de l’excĂ©s de mortalitat de l’1 de juny al 31 d’agost de 2022

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    Mortalitat; AnĂ lisi; PoblaciĂłMortalidad; AnĂĄlisis; PoblaciĂłnMortality; Analysis; PopulationAquest informe Ă©s fruit d’un treball col·laboratiu entre la DirecciĂł General de PlanificaciĂł i Recerca en Salut i la Secretaria de Salut PĂșblica del Departament de Salut, l’Àrea de Sistemes d’InformaciĂł del Servei CatalĂ  de la Salut, el Sistema d’InformaciĂł dels Serveis d’AtenciĂł PrimĂ ria de l’Institut CatalĂ  de la Salut i el Departament de FĂ­sica de la Universitat PolitĂšcnica de Catalunya, i ha estat dut a terme la tardor de 2022 arran de diferents informacions que han sorgit sobre un increment de la mortalitat entorn dels mesos d’estiu. Aquesta col·laboraciĂł explicita la multiplicitat de fonts d’informaciĂł, de perĂ­odes de referĂšncia, d’indicadors i de format en les taules, les figures i els mapes, tot i el treball en comĂș realitzat a l’hora de seleccionar els continguts, interpretar la informaciĂł i redactar-ne les conclusions

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

    Ischemia-reperfusion syndrome associated with liver transplantation: An update

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    Ischemia-reperfusion (I/R) injury is the main cause of both initial graft dysfunction and primary failure in liver transplantation. The search for therapeutic strategies to prevent I/R injury has led to research into promising drugs, although most have not been used clinically. Gene therapy requires better transfection techniques, avoiding vector toxicity, and ethical debate before being used clinically. Ischemic preconditioning is the first therapeutic strategy used in clinical practice to reduce I/R injury in hepatectomies for tumors. Future research will provide data on the effectiveness of ischemic preconditioning in reducing I/R injury associated with liver transplantation, and in reducing the vulnerability of steatotic grafts to I/R syndrome so that they can be used in transplantation, thus relieving the organ shortage.Peer Reviewe

    Observations and models of molecular clouds

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    SIGLEAvailable from British Library Lending Division - LD:D53362/85 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    Methodology for leakage isolation using pressure sensitivity analysis in water distribution networks

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    This letter proposes a phase-shifted pulse-width modulation (PS-PWM) technique for the flying capacitor (FC) multilevel converter that improves the quality of the line-to-line voltages. In traditional PS-PWM, the line-to-line voltages include intervals that switch between non-adjacent voltage levels, which deteriorates the harmonic performance. The proposed PS-PWM constantly achieves line-to-line voltages with switching transitions between two adjacent levels. The proposed modulation technique is implemented using two sets of n evenly phase-shifted carriers that are alternatively applied depending on the instantaneous value of the reference signal of each phase-leg. Furthermore, it can be implemented in FC multilevel converters with any number of levels while maintaining natural capacitor voltage balance. Experimental results from a four-level FC converter prototype are presented.Peer ReviewedPostprint (published version
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