30 research outputs found

    Effect of pulsed electric fields (PEF) combined with natural antimicrobial by-products against S. typhimurium

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    The effect against Salmonella enterica serovar Typhimurium of PEF treatment combined with cauliflower and mandarin by-product infusions at several concentrations (0, 1, 5, and 10% (w/v)) was evaluated at various incubation temperatures (10, 22, and 37 °C). The possible synergistic antimicrobial action of the combined process of Pulsed Electric Field (PEF) technology followed by exposure to the by-product infusions and the occurrence of sublethal cellular damage were also studied. Antimicrobial kinetics of by-product infusions alone or following PEF treatment were fitted to a Weibull model. Both mandarin and cauliflower by-product infusions showed a maximum antimicrobial effect against S. Typhimurium after 10 h at 37 °C when the microorganism was exposed to 10% of by-product infusion, achieving reductions of initial bacterial load up to undetectable levels. The effect of the PEF treatment (20 kV–900 μs) caused a reduction of 4 log cycles of the initial cell population (108 cfu/mL) of S. Typhimurium and 1 log cycle (90%) of cellular damage. Moreover, when the PEF pre-treated S. Typhimurium population was subjected to subsequent incubation in the presence of both by-product [10%] infusions, the microbial inactivation was faster, achieving a reduction of the initial bacterial load (4 log10 cycles) up to undetectable levels in 2 h. The kinetic values of the Weibull model were obtained. The higher the concentration of by-product infusion, temperature, and PEF treatment applied, the greater the kinetic parameter “b” values, which are related to the microbial inactivation rate. Therefore, the addition of cauliflower and mandarin by-product infusions could be a good additional control measure contributing to ensure bacterial counts below recommended limits in pasteurized PEF products during their storage at refrigeration temperatures.M. Sanz-Puig is grateful to the CSIC for providing a contract as a researcher working actively on project AGL 2013-48993-C2-2-R. The present research work was funded by the Ministry of Economy and Competitiveness through project AGL 2013-48993-C2-2-R and with FEDER funds. We are also grateful to INDULLEIDA, S.A. and TRASA, S.L. for providing the by-products that we worked with. Authors acknowledge L. Santos-Carvalho Erasmus Placement scholarship, and L.M. Cunha acknowledges support from the European Union (FEDER funds) and National Funds (FCT/MEC, Fundação para a Ciência e Tecnologia and Ministerio da Educação e Ciência) under the Partnership Agreements PT2020 UID/QUI/50006/2013–POCI/01/0145/FEDER/007265 (LAQV) and UID/AGR/04033/2013–POCI/01/0145/FEDER/006958 (CITAB).Peer reviewe

    Functionalization of gold nanostars with cationic ß-cyclodextrin-based polymer for drug co-loading and SERS monitoring

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    Gold nanostars (AuNSs) exhibit modulated plasmon resonance and have a high SERS enhancement factor. However, their low colloidal stability limits their biomedical application as a nanomaterial. Cationic ß-cyclodextrin-based polymer (CCD/P) has low cytotoxicity, can load and transport drugs more efficiently than the corresponding monomeric form, and has an appropriate cationic group to stabilize gold nanoparticles. In this work, we functionalized AuNSs with CCD/P to load phenylethylamine (PhEA) and piperine (PIP) and evaluated SERS-based applications of the products. PhEA and PIP were included in the polymer and used to functionalize AuNSs, forming a new AuNS-CCD/P-PhEA-PIP nanosystem. The system was characterized by UV–VIS, IR, and NMR spectroscopy, TGA, SPR, DLS, zeta potential analysis, FE-SEM, and TEM. Additionally, Raman optical activity, SERS analysis and complementary theoretical studies were used for characterization. Minor adjustments increased the colloidal stability of AuNSs. The loading capacity of the CCD/P with PhEA-PIP was 95 ± 7%. The physicochemical parameters of the AuNS-CCD/P-PhEA-PIP system, such as size and Z potential, are suitable for potential biomedical applications Raman and SERS studies were used to monitor PhEA and PIP loading and their preferential orientation upon interaction with the surface of AuNSs. This unique nanomaterial could be used for simultaneous drug loading and SERS-based detection

    Validation of three predictive models for suboptimal cytoreductive surgery in advanced ovarian cancer

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    The standard treatment for advanced ovarian cancer (AOC) is cytoreduction surgery and adjuvant chemotherapy. Tumor volume after surgery is a major prognostic factor for these patients. The ability to perform complete cytoreduction depends on the extent of disease and the skills of the surgical team. Several predictive models have been proposed to evaluate the possibility of performing complete cytoreductive surgery (CCS). External validation of the prognostic value of three predictive models (Fagotti index and the R3 and R4 models) for predicting suboptimal cytoreductive surgery (SCS) in AOC was performed in this study. The scores of the 3 models were evaluated in one hundred and three consecutive patients diagnosed with AOC treated in a tertiary hospital were evaluated. Clinicopathological features were collected prospectively and analyzed retrospectively. The performance of the three models was evaluated, and calibration and discrimination were analyzed. The calibration of the Fagotti, R3 and R4 models showed odds ratios of obtaining SCSs of 1.5, 2.4 and 2.4, respectively, indicating good calibration. The discrimination of the Fagotti, R3 and R4 models showed an area under the ROC curve of 83%, 70% and 81%, respectively. The negative predictive values of the three models were higher than the positive predictive values for SCS. The three models were able to predict suboptimal cytoreductive surgery for advanced ovarian cancer, but they were more reliable for predicting CCS. The R4 model discriminated better because it includes the laparotomic evaluation of the peritoneal carcinomatosis index

    Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

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    Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

    Análisis del comportamiento de sistemas estructurales de pórticos para galpones de grandes luces aplicando norma AISC-341

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    El presente trabajo desarrolla el análisis de sistemas estructurales de pórticos para galpones, utilizando pórticos con nudos rígidos y pórticos a base de reticulados. En la presente investigación se compara dos tipos de pórticos: Pórtico con Nudos Rígidos: Pórtico metálico, de perfiles de alma llena, específicamente perfiles tipo W, ASTM A36, la selección del perfil se hizo de acuerdo a los requerimientos de resistencia y lineamientos de la norma AISC 341, usando el método LRFD, las deflexiones y desplazamientos laterales debidas al sismo serán comparados de acuerdo a la Norma E-030 del Reglamento Nacional de Edificaciones.Tesi

    Análisis del comportamiento de sistemas estructurales de pórticos para galpones de grandes luces aplicando norma AISC-341

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    El presente trabajo desarrolla el análisis de sistemas estructurales de pórticos para galpones, utilizando pórticos con nudos rígidos y pórticos a base de reticulados. En la presente investigación se compara dos tipos de pórticos: Pórtico con Nudos Rígidos: Pórtico metálico, de perfiles de alma llena, específicamente perfiles tipo W, ASTM A36, la selección del perfil se hizo de acuerdo a los requerimientos de resistencia y lineamientos de la norma AISC 341, usando el método LRFD, las deflexiones y desplazamientos laterales debidas al sismo serán comparados de acuerdo a la Norma E-030 del Reglamento Nacional de Edificaciones.Tesi

    Caenorhabditis elegans as an in vivo model to assess fucoidan bioactivity preventing Helicobacter pylori infection

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    Currently, Helicobacter pylori is the unique biological carcinogenic agent. The search for antimicrobial alternatives to antibiotics against this pathogen has been categorized as a priority due to the drastic failure associated with current applied antibiotic therapy. The present study assessed the bioactive antimicrobial capability of fucoidan (“Generally Recognized as Safe” approval – European Commission December 2017) from different species of Phaeophyceae algae (Fucus vesiculosus, Undaria pinnatifida, Macrocystis pyrifera) against H. pylori. All the studied fucoidans showed bacteriostatic and bactericidal effects at the studied concentrations [5–100] μg ml−1 and exposure times [0–7 days]. The most effective anti-H. pylori fucoidan was validated in Caenorhabditis elegans as an in vivo model. C. elegans feed was supplemented with Undaria pinnatifida [0–100] μg ml−1 fucoidan, resulting in a significant improvement in lifespan, lowered H. pylori concentration in the digestive tract, and increased egg-laying pattern. New research lines proposing this compound as an active agent in nutraceutical and preventive novel therapies should be opened.The present research work has been supported by the funds provided by the Spanish Ministry of Economy and Competitiveness (MINECO) under both projects with reference AGL2014-53875-R and AGL2017-86840-C2-2-R. M. C. Pina-Pérez is also grateful to the EC providing a H2020 MSCA – IF Grant Agreement No. 748314.Peer reviewe

    Resistance changes in Salmonella enterica serovar Typhimurium treated by High Hydrostatic Pressure and Pulsed Electric Fields and assessment of virulence changes by using Caenorhabditis elegans as a test organism

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    The goal of this study was to evaluate the development of Salmonella enterica subsp. enterica serovar Typhimurium resistance against Pulsed Electric Fields (PEF) and High Hydrostatic Pressure (HHP), and to study the possible virulence changes of the resistant subpopulations using Caenorhabditis elegans. Results showed that S. Typhimurium became resistant to both non-thermal technologies after four consecutive treatments. Survival probability of the worms (C. elegans) increased significantly when they were fed with S. Typhimurium treated by PEF four consecutive times in comparison with the other two subpopulations, untreated and treated once. For HHP, results indicated that up to percentile 50%, the survival probability of worms fed with treated microorganisms (once and four times) was greater than that of worms fed with untreated ones. Also, the C. elegans egg-laying pattern was modified and there were significant differences in the number of eggs laid in the first two days among the three subpopulations studied. Consequently, although S. Typhimurium develops microbial resistance against PEF or HHP treatments, when it is applied repeatedly, its virulence against C. elegans appears to decrease.The present research work was funded by the Ministry of Economy and Competitiveness and with FEDER funds through project AGL 2013-48993-C2-2-R and AGL 2017-86840-C2-2-R. Authors acknowledge Erasmus internship scholarship given to Clara Torres. Authors Torres and Cunha also acknowledge the financial support from the national funds by Fundação para a Ciência e a Tecnologia, under project Pest-C/EQB/LA0006/2013.Peer reviewe

    Validación de material de apoyo audiovisual de diferentes danzas folclóricas chilenas

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    Tesis (Profesor de Educación Física, Licenciado en Educación)El folclore es parte de nuestra cultura, representa nuestras raíces y nos hace únicos en el mundo. Es por esto, que cada año se celebran las Fiestas Patrias donde los festejos y las tradiciones alcanzan su máxima expresión. En este contexto, la danza es una expresión artística que cobra protagonismo donde la coordinación y ritmo son importantes. Debido a las características anteriormente mencionadas, la danza se encuentra fuertemente ligada a la Educación Física y por este motivo fue incorporada como materia de estudio en el Ministerio de Educación (MINEDUC) y en la mayoría de los establecimientos educacionales, como unidad obligatoria en la asignatura Educación Física. Con el objetivo de crear un material educativo de fácil entendimiento para los alumnos, un grupo de estudiantes de Educación Física de la Universidad Andrés Bello desarrolló un DVD que incorporó información sobre las principales danzas tradicionales de Chile y su relación con las distintas zonas del país. El análisis sobre su impacto y efectividad en los alumnos, será materia de estudio en este seminario de grado a fin de establecer su potencial aporte a través de su implementación en centros educacionales. Durante el desarrollo de la investigación se llevará a cabo una encuesta enfocada a directivos, profesores y alumnos con el fin de obtener de primera fuente las impresiones de este trabajo realizado. La encuesta será realizada en cuatro colegios de Santiago: dos colegios particulares pagados de la comuna de Las Condes, un colegio particular pagado de la comuna de Vitacura y un cuarto colegio particular subvencionado de la comuna de La Pintana
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