35 research outputs found

    Polyester films obtained by noncatalyzed melt-condensation polymerization of aleuritic (9,10,16-Trihydroxyhexadecanoic) acid in air

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    To mimic nontoxic and fully biodegradable biopolymers like the plant cutin, polyester films from a natural occurring fatty polyhydroxyacid like aleuritic (9,10,16-trihydroxyhexadecanoic) acid have been prepared by noncatalyzed melt-polycondensation at moderate temperature (150°C) directly in air. The course of the reaction has been followed by infrared spectroscopy, 13C magic angle spinning nuclear magnetic resonance spectroscopy, differential scanning calorimetry and X-ray diffraction and well differentiated stages are observed. First, a high conversion esterification reaction leads to an amorphous rubbery, infusible, and insoluble material whose structure is made out of ester linkages mostly involving primary hydroxyls and partially branched by minor esterification with secondary ones. Following the esterification stage, the cleavage of vicinal secondary hydroxyls and further oxidation to carboxylic acid is observed at the near surface region of films. New carboxylic groups created also undergo esterification and generate cross-linking points within the polymer structure. Additionally, and despite the harsh preparation conditions used, very little additional side reaction like peroxidation and dehydration are observed. Results demonstrate the feasibility of polyester films fabrication from a reference fatty polyhydroxyacid like aleuritic acid by noncatalyzed melt-polycondensation directly in air. The methodology can potentially be extended to similar natural occurring hydroxyacids to obtain films and coatings to be used, for instance, as nontoxic and biodegradable food packaging materialPeer reviewe

    Valorization of Tomato Processing by-Products: Fatty Acid Extraction and Production of Bio-Based Materials

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    A method consisting of the alkaline hydrolysis of tomato pomace by-products has been optimized to obtain a mixture of unsaturated and polyhydroxylated fatty acids as well as a non-hydrolysable secondary residue. Reaction rates and the activation energy of the hydrolysis were calculated to reduce costs associated with chemicals and energy consumption. Lipid and non-hydrolysable fractions were chemically (infrared (IR) spectroscopy, gas chromatography/mass spectrometry (GC-MS)) and thermally (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)) characterized. In addition, the fatty acid mixture was used to produce cutin-based polyesters. Freestanding films were prepared by non-catalyzed melt-polycondensation and characterized by Attenuated Total Reflected-Fourier Transform Infrared (ATR-FTIR) spectroscopy, solid-state nuclear magnetic resonance (NMR), DSC, TGA, Water Contact Angles (WCA), and tensile tests. These bio-based polymers were hydrophobic, insoluble, infusible, and thermally stable, their physical properties being tunable by controlling the presence of unsaturated fatty acids and oxygen in the reaction. The participation of an oxidative crosslinking side reaction is proposed to be responsible for such modifications.Andalusian Regional Government P11-TEP-7418Spanish Ministerio de Economía y Competitividad AGL2015-65246-R and AGL2017-83036-RFondo Europeo de Desarrollo Regional (FEDER) AGL2015-65246-R and AGL2017-83036-

    Reversión de sedantes agonistas alfa-2-adrenérgicos en el perro

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    En el presente Artículo de Revisión se aporta una información amplia sobre los productos de LISO más frecuente en la reversión de los efectos sedantes de los agonistas alfa-2-adrenérgicos empleados en el perro: xilacina, medetomidina y romifidina. Se refieren los detalles farmacológicos, dosificación, efectos y aplicaciones de los siguientes productos: yohimbina, 4-aminopiridina, doxapram y atipamezol

    Salud bucodental y utilización de servicios odontológicos

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    En el Paraguay, los datos epidemiológicos sobre la salud bucodental y la utilización de los servicios en adultos son limitados, de ahí, la urgente necesidad de generar información para diseñar y establecer programas de salud pública acordes a las necesidades de dicha población. El objetivo de este estudio transversal retrospectivo fue determinar la situación de salud bucodental y el patrón de utilización de los servicios odontológicos de los pacientes atendidos en las cátedras de Operatoria Dental II y III de la carrera de Odontología de la Universidad Católica-Campus de Itapúa. La muestra incluyó 411 historias clínicas odontológicas de pacientes atendidos entre 2014 y 2017. La edad promedio de los pacientes fue de 28 años. La prevalencia de caries fue del 94,6%. El Índice de dientes cariados, perdidos y obturados promedio fue de 13,2 (DE± 6,9), siendo el mayor componente el de dientes cariados (7,0±4,5), seguido por el de dientes perdidos (4,4±5,7). Un alto porcentaje (77%) de los pacientes no tenía seguro médico al momento de consultar. El motivo de consulta actual del 42% fue la estética y el 64% sólo consulta al dentista cuando necesita. El valor promedio del índice de dientes cariados, perdidos y obturados (13,2) es catalogado como grave. El predominio de los componentes dientes cariados y perdidos es indicativo de un limitado acceso a los servicios odontológicos y tratamientos restauradores. Se requiere la instauración de estrategias de promoción de la salud y prevención de las afecciones bucodentales enmarcadas dentro de programas desde el primer nivel de atención

    HIV coinfection predicts failure of ledipasvir/sofosbuvir in treatment-naïve noncirrhotic patients with HCV genotype

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    The efficacy of licensed direct-acting antiviral (DAA) regimens is assumed to be the same for hepatitis C virus (HCV)–monoinfected patients (HCV-Mono) and HIV/HCV-coinfected patients (HCV-Co). However, the high sustained viral response (SVR) rates of DAA regimens and the small number of HIV-infected patients included in registration trials have made it difficult to identify predictors of treatment failure, including the presence of HIV. Methods. We compared treatment outcomes for ledipasvir/sofosbuvir (LDV/SOF) against HCV G1 in treatment-naïve HCV-Mono and HCV-Co without cirrhosis in a prospective registry of individuals receiving DAAs for HCV. Results. Up to September 2017, a total of 17 269 patients were registered, and 1358 patients (1055 HCV-Mono/303 HCV-Co) met the inclusion criteria. Significant differences between HCV-Mono and HCV-Co were observed for age, gender, and G1 subtype distribution. Among HCV-Co, 99.0% were receiving antiretroviral therapy. SVR rates for LDV/SOF at 8 weeks did not differ significantly between HCV-Mono and HCV-Co (96.9% vs 94.0%; P = .199). However, the SVR rate for LDV/SOF at 12 weeks was significantly higher for HCV-Mono than HCV-Co (97.2% vs 91.8%; P = .001). A multivariable logistic regression model including age, sex, liver stiffness, G1 subtype, HCV-RNA, HIV, and treatment duration showed the factors associated with treatment failure to be male sex (adjusted odds ratio [aOR], 2.49; 95% confidence interval [CI], 1.27–4.91; P = .008) and HIV infection (aOR, 2.23; 95% CI, 1.13–4.38; P = .020). Conclusions. The results of this large prospective study analyzing outcomes for LDV/SOF against HCV G1 in treatment-naïve noncirrhotic patients suggest that HIV infection is a predictor of treatment failure in patients with chronic hepatitis C.This work was supported by the Spanish AIDS Research Network (RD16/0025/0017), which is included in the Spanish I+D+I Plan and is co-financed by ISCIII-Subdirección General de Evaluacion and European Funding for Regional Development (FEDER), and the Fondo de Investigación de Sanidad en España (FIS)/Instituto de Salud Carlos III (Spanish Health Research Funds; PI17/00657)

    Serotypes and Clonal Composition of Streptococcus pneumoniae Isolates Causing IPD in Children and Adults in Catalonia before 2013 to 2015 and after 2017 to 2019 Systematic Introduction of PCV13

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    The goal of this study was to investigate the distribution of serotypes and clonal composition of Streptococcus pneumoniae isolates causing invasive pneumococcal disease (IPD) in Catalonia, before and after systematic introduction of PCV13. Pneumococcal strains isolated from normally sterile sites obtained from patients of all ages with IPD received between 2013 and 2019 from 25 health centers of Catalonia were included. Two study periods were defined: presystematic vaccination period (2013 and 2015) and systematic vaccination period (SVP) (2017 to 2019). A total of 2,303 isolates were analyzed. In the SVP, there was a significant decrease in the incidence of IPD cases in children 5 to 17 years old (relative risk [RR] 0.61; 95% confidence interval [CI] 0.38 to 0.99), while there was a significant increase in the incidence of IPD cases in 18- to 64-year-old adults (RR 1.33; 95% CI 1.16 to 1.52) and adults over 65 years old (RR 1.23; 95% CI 1.09 to 1.38). Serotype 8 was the major emerging serotype in all age groups except in 5- to 17-year-old children. In children younger than 5 years old, the main serotypes in SVP were 24F, 15A, and 3, while in adults older than 65 years they were serotypes 3, 8, and 12F. A significant decrease in the proportions of clonal complexes CC156, CC191, and ST306 and an increase in those of CC180, CC53, and CC404 were observed. A steady decrease in the incidence of IPD caused by PCV13 serotypes indicates the importance and impact of systematic vaccination. The increase of non-PCV13 serotypes highlights the need to expand serotype coverage in future vaccines and rethink vaccination programs for older adults. IMPORTANCE We found that with the incorporation of the PCV13 vaccine, the numbers of IPD cases caused by serotypes included in this vaccine decreased in all of the age groups. Still, there was an unforeseen increase of the serotypes not included in this vaccine causing IPD, especially in the >65-year-old group. Moreover, a significant increase of serotype 3 included in the vaccine has been observed; this event has been reported by other researchers. These facts call for the incorporation of more serotypes in future vaccines and a more thorough surveillance of the dynamics of this microorganism

    Recomanacions per a la prevenció i el control de la tuberculosi pediàtrica a Catalunya

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    Tuberculosi pediàtrica; Diagnòstic de malalties; TractamentsTuberculosis pediátrica; Diagnóstico de enfermedades; TratamientosPediatric tuberculosis; Disease diagnosis; TreatmentsLa finalitat d’aquest document és revisar, des d’una perspectiva multidisciplinària, els reptes en el diagnòstic i el tractament de la TB pediàtrica, l’optimització de la realització dels estudis de contactes, la integració del cribratge de la infecció tuberculosa en el Programa de seguiment del nen sa de l’atenció primària (AP) i el model d’organització assistencial, amb l’objectiu de realitzar recomanacions pràctiques que contribueixin a millorar les respostes que cal articular per a la prevenció i el control de la TB pediàtrica al territori

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Cutin syntesis: A slippery paradigm

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    Despite its biological importance, the mechanism of construction of cutin, the polymer matrix of plant cuticles, has not yet been elucidated. Recently, progress on lipid barrier formation of polymers such as cutin and suberin has been recently reviewed by Pollard et al.1 In their review the authors state that the ubiquitous cutin is the least understood of the plant extracellular polymers and that major questions about cutin structure and its macromolecular assembly remain to be resolved. At the time this paper was being published our research group has developed a new hypothesis on plant cutin synthesisMinisterio de Educación y Ciencia for partial financial supportPeer reviewe

    Polyester films obtained by noncatalyzed melt-condensation polymerization of aleuritic (9,10,16-Trihydroxyhexadecanoic) acid in air

    Get PDF
    To mimic nontoxic and fully biodegradable biopolymers like the plant cutin, polyester films from a natural occurring fatty polyhydroxyacid like aleuritic (9,10,16-trihydroxyhexadecanoic) acid have been prepared by noncatalyzed melt-polycondensation at moderate temperature (150°C) directly in air. The course of the reaction has been followed by infrared spectroscopy, 13C magic angle spinning nuclear magnetic resonance spectroscopy, differential scanning calorimetry and X-ray diffraction and well differentiated stages are observed. First, a high conversion esterification reaction leads to an amorphous rubbery, infusible, and insoluble material whose structure is made out of ester linkages mostly involving primary hydroxyls and partially branched by minor esterification with secondary ones. Following the esterification stage, the cleavage of vicinal secondary hydroxyls and further oxidation to carboxylic acid is observed at the near surface region of films. New carboxylic groups created also undergo esterification and generate cross-linking points within the polymer structure. Additionally, and despite the harsh preparation conditions used, very little additional side reaction like peroxidation and dehydration are observed. Results demonstrate the feasibility of polyester films fabrication from a reference fatty polyhydroxyacid like aleuritic acid by noncatalyzed melt-polycondensation directly in air. The methodology can potentially be extended to similar natural occurring hydroxyacids to obtain films and coatings to be used, for instance, as nontoxic and biodegradable food packaging materialPeer reviewe
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