27 research outputs found

    Real-time optimization-based reference calculation integrated control for MMCs considering converter limitations

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    © 2021 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting /republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThe paper addresses a real-time optimization-based reference calculation integrated with a control structure for Modular Multilevel Converters (MMC) operating under normal and constrained situations (where it has reached current and/or voltage limitations, e.g. during system faults). The algorithm prioritizes to satisfy the Transmission System Operators (TSO) AC grid current demanded set-points. The constrained optimization problem is formulated based on the steady-state model of the MMC, whereby the prioritization is achieved through distinct weights defined in the Objective Function’s (OF) terms. The resultant optimization problem, however, is highly nonlinear requiring high computation burden to be solved in real-time. To overcome this issue, this paper applies a Linear Time-Varying (LTV) approximation, where the nonlinear dynamics of the system are represented as constant parameters, while a Linear Time-Invariant (LTI) system is used to formulate the optimization constraints. The converter's current references are determined in real-time by solving a constrained linearized optimization problem at each control time step, considering the TSO's demands, the current MMC operating point and its physical limitations. Finally, the linearized-optimization problem is integrated with the MMC controllers and evaluated under different network conditions, where the results indicated that method can be potentially employed to obtain the MMCs current references.Peer ReviewedPostprint (author's final draft

    A protocol for wide-scope non-target analysis of contaminants in small amounts of biota using bead beating tissuelyser extraction and LC-HRMS

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    This work describes a robust and powerful method for wide-scope target and non-target analysis of xenobiotics in biota samples based on bead beating tissuelyser extraction, solid phase extraction (SPE) clean-up and further detection by liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). Unlike target methodologies, non-target methods usually aim at determining a wide range of still unknown substances with different physicochemical properties. Therefore, losses during the extraction process were minimised. Apart from that, the reduction of possible interferences showed to be necessary to expand the number of compounds that can be detected. This was achieved with an additional SPE clean-up step carried out with mixed-bed multi-layered cartridges. The method was validated with a set of 27 compounds covering a wide range of physicochemical properties, and further applied to the analysis of krill and fish samples. •The bead beating extraction was efficient for a wide range of organic pollutants in small quantities of biota samples. •Multi-layered solid phase extraction clean-up yield a wide xenobiotics coverage reducing matrix effects. •Method validation with 27 compounds led to a suitable method for non-target analysis of organic pollutants in biota.ICRA researchers thank funding from CERCA program. This work has been funded by the Spanish Ministry of Economy and Competitiveness (MINECO): project PLAS-MED (CTM2017-89701-C3-2-R). SRM acknowledges the Ramon y Cajal program (RYC-2014-16707). This project has been funded by the Chilean Antarctic Institute through project RT_12_17. The Chilean Agency for Research and Development through the FONDAP initiative (grant no. 15150003) “Centro de Investigación Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL)”; and “Anillos de Investigación en Ciencia Antartica (grant no. ANID-PIA-ACT-INACH Anillo ACT192057). IDAEA researchers acknowledge the Spanish Ministry of Science and Innovation (Severo Ochoa, Project CEX2018-000794-S).Peer reviewe

    A Novel Generation of Tailored Antimicrobial Drugs Based on Recombinant Multidomain Proteins

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    Antibiotic resistance has exponentially increased during the last years. It is necessary to develop new antimicrobial drugs to prevent and treat infectious diseases caused by multidrug- or extensively-drug resistant (MDR/XDR)-bacteria. Host Defense Peptides (HDPs) have a versatile role, acting as antimicrobial peptides and regulators of several innate immunity functions. The results shown by previous studies using synthetic HDPs are only the tip of the iceberg, since the synergistic potential of HDPs and their production as recombinant proteins are fields practically unexplored. The present study aims to move a step forward through the development of a new generation of tailored antimicrobials, using a rational design of recombinant multidomain proteins based on HDPs. This strategy is based on a two-phase process, starting with the construction of the first generation molecules using single HDPs and further selecting those HDPs with higher bactericidal efficiencies to be combined in the second generation of broad-spectrum antimicrobials. As a proof of concept, we have designed three new antimicrobials, named D5L37βD3, D5L37D5L37 and D5LAL37βD3. After an in-depth exploration, we found D5L37D5L37 to be the most promising one, since it was equally effective against four relevant pathogens in healthcare-associated infections, such as methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis (MRSE) and MDR Pseudomonas aeruginosa, being MRSA, MRSE and P. aeruginosa MDR strains. The low MIC values and versatile activity against planktonic and biofilm forms reinforce the use of this platform to isolate and produce unlimited HDP combinations as new antimicrobial drugs by effective means.info:eu-repo/semantics/publishedVersio

    High frequency of acute decompensation and cancer in patients with compensated cirrhosis due to nonalcoholic fatty liver disease : A retrospective cohort study

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    The natural history of compensated cirrhosis due to nonalcoholic fatty liver disease (NAFLD) has not been completely characterized. The aim of the present study was to assess the incidence and risk factors of acute decompensation of cirrhosis, hepatocellular carcinoma, and extrahepatic cancers. This was a multicenter, retrospective, cohort study including 449 patients with compensated cirrhosis due to NAFLD. We calculated cumulative incidences and used competitive risk analysis to determine the risk factors associated with decompensation and cancer development. Over a median of 39 months of follow-up, 124 patients (28%) presented acute decompensation. The most frequent decompensation was ascites (21%) followed by hepatic encephalopathy (15%), variceal bleeding (9%), and spontaneous bacterial peritonitis (3%). Acute-on-chronic liver failure was diagnosed in 6% of patients during follow-up. Liver function parameters and specifically an albumin level below 40 g/L were independently associated with an increased risk of decompensation. The presence of ischemic heart disease was independently associated with acute decompensation. Seventy-eight patients (18%) developed hepatocellular carcinoma or extrahepatic cancers during follow-up (51 and 27, respectively). Conclusion : Patients with compensated cirrhosis due to NAFLD are at high risk of severe liver complications, such as the development of acute decompensation, in a relative short follow-up time. This population is at high risk of hepatic and extrahepatic cancers. The analysis of a large contemporary cohort of 449 patients with compensated cirrhosis due to non-alcoholic fatty liver disease shows a high frequency of acute decompensations (AD) and development of cancer during 39 months of follow-up. Almost 28% of the cohort developed acute decompensation and 18% developed hepatocellular carcinoma (HCC) or extrahepatic cancer. Predictors of decompensation are mainly related to liver function and portal hypertension

    A community challenge for a pancancer drug mechanism of action inference from perturbational profile data

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    The Columbia Cancer Target Discovery and Development (CTD2) Center is developing PANACEA, a resource comprising dose-responses and RNA sequencing (RNA-seq) profiles of 25 cell lines perturbed with similar to 400 clinical oncology drugs, to study a tumor-specific drug mechanism of action. Here, this resource serves as the basis for a DREAM Challenge assessing the accuracy and sensitivity of computational algorithms for de novo drug polypharmacology predictions. Dose-response and perturbational profiles for 32 kinase inhibitors are provided to 21 teams who are blind to the identity of the compounds. The teams are asked to predict high-affinity binding targets of each compound among similar to 1,300 targets cataloged in DrugBank. The best performing methods leverage gene expression profile similarity analysis as well as deep-learning methodologies trained on individual datasets. This study lays the foundation for future integrative analyses of pharmacogenomic data, reconciliation of polypharmacology effects in different tumor contexts, and insights into network-based assessments of drug mechanisms of action.Peer reviewe

    Famílies botàniques de plantes medicinals

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    Facultat de Farmàcia, Universitat de Barcelona. Ensenyament: Grau de Farmàcia, Assignatura: Botànica Farmacèutica, Curs: 2013-2014, Coordinadors: Joan Simon, Cèsar Blanché i Maria Bosch.Els materials que aquí es presenten són els recull de 175 treballs d’una família botànica d’interès medicinal realitzats de manera individual. Els treballs han estat realitzat per la totalitat dels estudiants dels grups M-2 i M-3 de l’assignatura Botànica Farmacèutica durant els mesos d’abril i maig del curs 2013-14. Tots els treballs s’han dut a terme a través de la plataforma de GoogleDocs i han estat tutoritzats pel professor de l’assignatura i revisats i finalment co-avaluats entre els propis estudiants. L’objectiu principal de l’activitat ha estat fomentar l’aprenentatge autònom i col·laboratiu en Botànica farmacèutica

    Chromonic nematic liquid crystals in a room-temperature ionic liquid

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    Planar multiaromatic molecules hierarchically and selectively arrange into nematic chromonic liquid crystals in the room temperature ionic liquid 2-hydroxyethylammonium formate. In a proof of concept, these liquid crystals were used as reaction media to produce mesostructured silica materials under mild biomimetic conditions. Several other applications are envisaged.Peer reviewe

    A protocol for wide-scope non-target analysis of contaminants in small amounts of biota using bead beating tissuelyser extraction and LC-HRMS

    Get PDF
    This work describes a robust and powerful method for wide-scope target and non-target analysis of xenobiotics in biota samples based on bead beating tissuelyser extraction, solid phase extraction (SPE) clean-up and further detection by liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). Unlike target methodologies, non-target methods usually aim at determining a wide range of still unknown substances with different physicochemical properties. Therefore, losses during the extraction process were minimised. Apart from that, the reduction of possible interferences showed to be necessary to expand the number of compounds that can be detected. This was achieved with an additional SPE clean-up step carried out with mixed-bed multi-layered cartridges. The method was validated with a set of 27 compounds covering a wide range of physicochemical properties, and further applied to the analysis of krill and fish samples. •The bead beating extraction was efficient for a wide range of organic pollutants in small quantities of biota samples. •Multi-layered solid phase extraction clean-up yield a wide xenobiotics coverage reducing matrix effects. •Method validation with 27 compounds led to a suitable method for non-target analysis of organic pollutants in biota.ICRA researchers thank funding from CERCA program. This work has been funded by the Spanish Ministry of Economy and Competitiveness (MINECO): project PLAS-MED (CTM2017-89701-C3-2-R). SRM acknowledges the Ramon y Cajal program (RYC-2014-16707). This project has been funded by the Chilean Antarctic Institute through project RT_12_17. The Chilean Agency for Research and Development through the FONDAP initiative (grant no. 15150003) “Centro de Investigación Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL)”; and “Anillos de Investigación en Ciencia Antartica (grant no. ANID-PIA-ACT-INACH Anillo ACT192057). IDAEA researchers acknowledge the Spanish Ministry of Science and Innovation (Severo Ochoa, Project CEX2018-000794-S).Peer reviewe

    Photoinduced upgrading of lactic acid-based solvents to block copolymer surfactants

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    We report a new strategy toward the development of block copolymer surfactants from chemicals of the lactic acid family. A particularly unique aspect of this work is the use of green solvents as biobased platform chemicals to generate well-defined and nanostructure-forming materials. Herein, efficient functionalization of ethyl lactate (EL) and N,N-dimethyl lactamide (DML) solvents with acrylate groups generated monomers that could be polymerized by the photoinduced copper-catalyzed living radical polymerization process to yield polymeric materials with different water solubilities. These lactic acid-derived monomers were used as a major component in well-defined diblock copolymers composed of poly(EL acrylate) and poly(DML acrylate) segments as hydrophobic and hydrophilic building blocks, respectively. The resulting amphiphilic copolymers could self-assemble in aqueous solution to form nanoparticles with different morphologies (e.g., large-compound micelles and vesicles). Subsequently, the formed amphiphilic polymers were employed as efficient stabilizers in the emulsion polymerization of methyl methacrylate and styrene, offering a facile method for the synthesis of well-defined and stable polymer latexes in the range of 100-200 nm, demonstrating the practical significance of these biobased polymers in nanomaterial synthesis

    A Novel Generation of Tailored Antimicrobial Drugs Based on Recombinant Multidomain Proteins

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    Antibiotic resistance has exponentially increased during the last years. It is necessary to develop new antimicrobial drugs to prevent and treat infectious diseases caused by multidrug- or extensively-drug resistant (MDR/XDR)-bacteria. Host Defense Peptides (HDPs) have a versatile role, acting as antimicrobial peptides and regulators of several innate immunity functions. The results shown by previous studies using synthetic HDPs are only the tip of the iceberg, since the synergistic potential of HDPs and their production as recombinant proteins are fields practically unexplored. The present study aims to move a step forward through the development of a new generation of tailored antimicrobials, using a rational design of recombinant multidomain proteins based on HDPs. This strategy is based on a two-phase process, starting with the construction of the first generation molecules using single HDPs and further selecting those HDPs with higher bactericidal efficiencies to be combined in the second generation of broad-spectrum antimicrobials. As a proof of concept, we have designed three new antimicrobials, named D5L37βD3, D5L37D5L37 and D5LAL37βD3. After an in-depth exploration, we found D5L37D5L37 to be the most promising one, since it was equally effective against four relevant pathogens in healthcare-associated infections, such as methicillin-susceptible (MSSA) and methicillin-resistant (MRSA) Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis (MRSE) and MDR Pseudomonas aeruginosa, being MRSA, MRSE and P. aeruginosa MDR strains. The low MIC values and versatile activity against planktonic and biofilm forms reinforce the use of this platform to isolate and produce unlimited HDP combinations as new antimicrobial drugs by effective means
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