Estudi d’un pretractament aerobi per a la degradació de compostos lignocel·lulòsics involucrats en la digestió anaeròbica dels residus municipals

Treballs Finals de Grau d'Enginyeria Química, Facultat de Química, Universitat de Barcelona, Curs: 2013-2014, Tutor: Joan Mata ÁlvarezThe introduction of anaerobic digestion (AD) for the treatment of the organic matter, such as the organic fraction of municipal solid waste (OFMSW), nowadays is getting more interesting. The main difficulty in the treatment of this waste fraction is the hydrolysis step because of the complexity of organic matter. To avoid these problems, many pretreatments are used in order to increase the solubilization by breaking complex molecules into simple monomers, and to improve the efficiency of AD due to increase the hydrolysis, which is the rate-limiting step. In this project, a biological pretreatment is used to increase the hydrolytic step by using mature compost. The compost fermentative bacteria may break the complex molecules and/or the lignocellulosic materials by means of a fast organic matter solubilization of OFMSW and of bagasse. The results from precomposting the OFMSW indicate that the best conditions of organic matter solubilization were 10% compost and 1 day. Increments of biomethane production of approximately 30% can be achieved in these conditions. A preliminary study of the economic viability of the process shows that these results can be carried out the precomposting on an industrial scale. In the case of bagasse, precomposting mean a decrease in the results so, for this kind of materials with a high soluble fraction composed by very degradable compounds, such as sugars, this pretreatment is not a good option

Monitoring of miR-181a-5p and miR-155-5p Plasmatic Expression as Prognostic Biomarkers for Acute and Subclinical Rejection in de novo Adult Liver Transplant Recipients.

Background and Aims: News strategies for the accurate assessment of the state of immunosuppression (IS) in liver transplant recipients are needed to prevent rejection and minimize drug-related side effects. miRNAs can potentially be used as diagnostic or prognostic biomarkers in transplant patients. This study evaluated the capacity of a plasmatic miRNA panel (miR-155-5p, miR-122-5p, miR-181a-5p, and miR148-3p) as an early non-invasive prognostic and diagnostic biomarker for T cell-mediated acute rejection (TCMAR) and subclinical rejection (SCR) in adult liver recipients. Methods: A total of 145 liver recipients were included. All patients received a calcineurin inhibitor with or without mycophenolate mofetil and methylprednisolone. Plasmatic miRNA expression was assessed by qPCR before and at different time-points after liver transplantation. Results: Seventeen patients experienced TCMAR, and eight were diagnosed with SCR during the protocol biopsy at the 3rd month post-transplantation. Pre-transplantation, miR-155-5p expression was significantly higher in TCMAR patients and in SCR patients than in non-rejectors, and miR-181a-5p expression was also significantly higher in SCR patients than in non-rejectors. Post-transplantation, before transaminase-level modification, significantly increased miR-181a-5p, miR-155-5p, and miR-122-5p expression was observed in TCMAR and SCR patients. Binary logistic regression analyses showed, post-transplantation, that TCMAR risk was better predicted by individual expression of miR-181a-5p (LOGIT = -6.35 + 3.87*miR-181a-5p), and SCR risk was better predicted by the combination of miR-181a-5p and miR-155-5p expression (LOGIT = -5.18 + 2.27*miR-181a-5p+1.74*miR-155-5p). Conclusions: Pre-transplantation plasmatic miR-155-5p expression may be useful for stratifying low-immunologic-risk patients, and post-transplantation miR-181a-5p and miR-155-5p may be candidates for inclusion in early, non-invasive prognostic biomarker panels to prevent TCMAR or SCR and better identify patient candidates for IS minimization. Large prospective randomized multicenter trials are needed to refine the cut-off values and algorithms and validate the clinical usefulness of these biomarkers