Mass transfer vectors for nitric oxide removal through biological treatments

The reduction of nitric oxide (NO) emissions to atmosphere has been recently addressed using biological technologies. However, NO removal through bioprocesses is quite challenging due to the low solubility of NO in water. Therefore, the abatement of NO emissions might be improved by adding a chelating agent or a mass transfer vector (MTV) to increase the solubility of this pollutant into the aqueous phase where the bioprocess takes place. This research seeks to assess the performance of different non-aqueous phase liquids (NAPs): n-hexadecane (HEX), diethyl sebacate (DSE), 1,1,1,3,5,5,5-heptamethyl-trisiloxane (HTX), 2,2,4,4,6,8,8-heptamethylnonane (HNO), and high temperature silicone oil (SO) in chemical absorption–biological reduction (CABR) integrated systems. The results showed that HNO and HTX had the maximum gas-liquid mass transfer capacity, being 0.32 mol NO/kmol NAP and 0.29 mol NO/kmol NAP, respectively. When an aqueous phase was added to the system, the mass transfer gas–liquid of NO was increased, with HTX reaching a removal efficiency of 82 ± 3% NO with water, and 88 ± 6% with a phosphate buffer solution. All NAPs were tested for short-term toxicity assessment and resulted neither toxic nor inhibitory for the biological activity (denitrification). DSE was found to be biodegradable, which could limit its applicability in biological processes for gas treatment. Finally, in the CABR system tests, it was shown that NO elimination improved in a short time (30 min) when the three mass transfer vectors (HEX, HTX, HNO) were added to enriched denitrifying bacteria.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. David Cubides is a fellow of Eurecat’s “Vicente López” PhD grant program. This work was financially supported by the Catalan Government through the funding grant ACCIÓ-Eurecat (Project PRIV2020/21-AIRECAT). The authors acknowledge the Spanish Government, through the project RTI2018-099362-B-C21 MINECO/FEDER, EU, for the financial support provided to perform this research.Peer ReviewedPostprint (published version

Anàlisi de l'ADN mitocondrial en el trastorn mental greu

Schizophrenia, bipolar disorder and major depressive disorder are mental illnesses with unknown ethology. However, genetic epidemiological studies have identified a major genetic contribution that interacts with environmental factors. Several genetic studies support this genetic contribution but large nuclear genome-wide association studies have thus far not yielded a clear disease-associated genetic marker for any psychiatric disorder. Most genetic studies are based on the nuclear genome but almost all cells contain another genome: the mitochondrial genome (mtDNA) which plays an essential role in energy production and cell maintenance. The present work analyses the implication of mtDNA in three major mental disorders: schizophrenia, bipolar disorder and major depressive disorder. The paper Torrell H, et al, Am J Med Genet 2013 analyzed the mtDNA expression, content and presence of the common deletion in a myelinated region of the brain in schizophrenia (SCH), bipolar disorder (BD) and major depressive disorder (MDD) patients because the mtDNA is vital to the proper function of the respiratory chain. The method used for obtaining these results was reverse transcription quantitative real-time PCR (RT-qPCR) due to its high specificity, large dynamic range, and high accuracy. However, a lack of consensus exists on how best to perform and interpret RT-qPCR data and for that reason we first identified and evaluated suitable reference genes and variables related to clinical, demographic, and specimen characteristics of each sample that could affect the interpretation of RT-qPCR data. We identified five potential reference genes and the RNA quality index as highly correlated with gene expression and these results were published in a previous paper Abasolo N, Torrell H, et al,No es coneix encara què causa l’esquizofrènia, el trastorn bipolar, la depressió major i altres trastorns mentals greus però els factors genètics hi tenen un paper rellevant. La majoria d’estudis genètics han buscat mutacions o variants de risc associades a la malaltia en el genoma nuclear, però gairebé totes les cèl•lules humanes contenen un altre genoma en els mitocondris. Aquest altre genoma és l’ADN mitocondrial (ADNmt), de cabdal importància per a la generació d’energia de totes les cèl•lules. El present treball de tesi analitza la implicació de l’ADNmt en tres trastorns mentals greus: esquizofrènia, trastorn bipolar i depressió major. El treball Torrell H, et al, Am J Med Genet 2013 presenta els resultats de l’anàlisi de l’ADNmt en teixit cerebral post mortem d’individus amb diagnòstic d’esquizofrènia, trastorn bipolar o depressió major en comparació amb individus control, convertint-se en el segon estudi que analitza l’expressió dels transcrits mitocondrials, el número de còpies de l’ADNmt i la presència de delecions en aquest en teixit cerebral. Aquest anàlisi es basa en la tècnica de la PCR quantitativa (qPCR de l’anglès quantitative Polymerase Chain Reaction), una tècnica molt robusta però que tanmateix requereix el seguiment de criteris i passos metodològics per assolir resultats fiables. Per aquest motiu, previ a l’anàlisi de l’ADNmt en teixit cerebral aquestes mostres, vam realitzar un estudi per identificar els gens de referència més idonis per a normalitzar els nivells d’expressió dels transcrits mitocondrials; i també per conèixer quines característiques dels bioespècimens podien interferir en l’anàlisi d’expressió. Vam identificar cinc gens de referència òptims per a aquestes mostres de teixit de còrtex occipital; i que la qualitat de l’ARN emprat era