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The oxidation of proteins and, in particular, of tryptophan (Trp) residues leads to chemical modifications that can affect the structure and function. The oxidative damage to proteins in photochemical processes is relevant in the skin and eyes and is related to a series of pathologies triggered by exposure to electromagnetic radiation. In this work, we studied the photosensitized formation of N-formylkynurenine (NFKyn) from Trp in different reaction systems. We used two substrates: free Trp and a peptide of nine amino acid residues, with Trp being the only oxidizable residue. Two different photosensitizers were employed: Rose Bengal (RB) and pterin (Ptr). The former is a typical type II photosensitizer [acts by producing singlet oxygen (1O2)]. Ptr is the parent compound of oxidized or aromatic pterins, natural photosensitizers that accumulate in human skin under certain pathological conditions and act mainly through type I mechanisms (generation of radicals). Experimental data were collected in steady photolysis, and the irradiated solutions were analyzed by chromatography (HPLC). Results indicate that the reaction of Trp with 1O2 initiates the process leading to NFKyn, but different competitive pathways take place depending on the photosensitizer and the substrate. In Ptr-photosensitization, a type I mechanism is involved in secondary reactions accelerating the formation of NFKyn when free Trp is the substrate.
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Quinurenina , Oxidación-Reducción , Fármacos Fotosensibilizantes , Rosa Bengala , Triptófano , Triptófano/química , Quinurenina/química , Quinurenina/análogos & derivados , Quinurenina/metabolismo , Fármacos Fotosensibilizantes/química , Rosa Bengala/química , Péptidos/química , Oxígeno Singlete/química , Pterinas/química , Cromatografía Líquida de Alta Presión , Fotólisis , HumanosRESUMEN
Resumen Objetivo: El objetivo de este estudio fue estimar si el uso de anticoagulantes se asociaba con una diferencia en la frecuencia de trombosis de cualquier sitio, hemorragia mayor y mortalidad en adultos con coexistencia de ambas patologías. Método: Se realizó un estudio de cohorte retrospectivo en cuatro centros de alta complejidad. Se incluyeron mayores de 18 años con ERC en hemodiálisis y FA no valvular, con indicación de anticoagulación (CHA2DS2VASc ≥ 2). El desenlace primario fue la ocurrencia de sangrado mayor, evento trombótico (accidente vascular cerebral, infarto agudo al miocardio o enfermedad tromboembólica venosa) o muerte. Se realizó ajuste por variables de confusión por regresión logística. Resultados: De los 158 pacientes incluidos, el 61% (n = 97) recibieron anticoagulante. El desenlace principal se encontró en el 84% de quienes recibieron anticoagulación y en el 70% de quienes no la recibieron (OR: 2.12, IC95%: 0.98-4.57; luego del ajuste OR: 2.13, IC95%: 1.04-4.36). De los desenlaces mayores se presentaron sangrado en el 52% vs. el 34% (OR: 2.03; IC95%: 1.05-3.93), trombosis en el 35% vs. el 34% (OR: 1.03; IC95%: 0.52-2.01) y muerte en el 46% vs. el 41% (OR: 1.25; IC95%: 0.65-2.38). Conclusiones: Los resultados de este estudio sugieren un incremento en el riesgo de sangrado en los pacientes con FA y ERC en hemodiálisis que reciben anticoagulación, sin disminución del riesgo de eventos trombóticos ni de muerte.
Abstract Objective: The aim of this study was to estimate whether the consumption of anticoagulants was associated with a difference in the frequency of thrombosis of any site, major bleeding and mortality, in adults with both diseases. Method: A retrospective cohort study was carried out in four high complexity centers. Patients older than 18 years with CKD on hemodialysis and non-valvular AF, with an indication for anticoagulation (CHA2DS2VASc ≥ 2), were included. The primary outcome was the occurrence of: major bleeding, thrombotic event (cerebrovascular accident, acute myocardial infarction or venous thromboembolic disease) or death. Adjustment for confounding variables was performed using logistic regression. Results: From 158 patients included, 61% (n = 97) received an anticoagulant. The main outcome was found in 84% of those who received anticoagulation and 70% of those who did not (OR: 2.12, 95%CI: 0.98-4.57; after the adjusted analysis OR: 2.13, 95%CI: 1.04-4.36). Separate outcomes were bleeding in 52% vs. 34% (OR: 2.03; 95%CI: 1.05-3.93), thrombosis in 35% vs. 34% (OR: 1.03; 95%CI: 0.52-2-01) and death in 46% vs. 41% (OR: 1.25; 95%CI: 0.65-2.38). Conclusions: The results of this study suggest an increased risk of bleeding in patients with AF and CKD on hemodialysis receiving anticoagulation, without a decrease in the risk of thrombotic events or all-cause mortality.
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This study assessed the effects of pollutants on Magallana gigas along a coastal zone with different levels of human activity: a highly impacted zone in the Bahía Blanca Estuary and a less impacted zone on the adjacent sandy beaches. Oysters collected in 2021 were analyzed for various factors, including metals, polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides, microplastics, oxidative stress and histology. Oysters of both environments exhibited detectable concentrations of all these pollutants in their tissues. However, the estuarine oysters showed higher concentrations of Zn, Cu and As and total PAHs than the beach oysters. Banned organochlorine pesticides were detected only in beach oysters. Estuarine oysters displayed morphological changes in their digestive gland including a reduction in the mean epithelial thickness of the tubule and elevated lipid peroxidation levels, indicating cellular damage. This study underscores the widespread presence of pollutants in M. gigas, indicating the need for effective strategies to safeguard coastal ecosystem health.
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Monitoreo del Ambiente , Estuarios , Ostreidae , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Animales , Contaminantes Químicos del Agua/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Argentina , Hidrocarburos Clorados/análisis , Microplásticos/análisis , Plaguicidas/análisis , Metales/análisis , PlayasRESUMEN
Shade avoidance syndrome is an important adaptive strategy. Under shade, major transcriptional rearrangements underlie the reallocation of resources to elongate vegetative structures and redefine the plant architecture to compete for photosynthesis. BBX28 is a B-box transcription factor involved in seedling de-etiolation and flowering in Arabidopsis (Arabidopsis thaliana), but its function in shade-avoidance response is completely unknown. Here, we studied the function of BBX28 using two mutant and two transgenic lines of Arabidopsis exposed to white light and simulated shade conditions. We found that BBX28 promotes hypocotyl growth under shade through the phytochrome system by perceiving the reduction of red photons but not the reduction of photosynthetically active radiation or blue photons. We demonstrated that hypocotyl growth under shade is sustained by the protein accumulation of BBX28 in the nuclei in a CONSTITUTIVE PHOTOMORPHOGENESIS1 (COP1)-dependent manner at the end of the photoperiod. BBX28 up-regulates the expression of transcription factor- and auxin-related genes, thereby promoting hypocotyl growth under prolonged shade. Overall, our results suggest the role of BBX28 in COP1 signaling to sustain the shade-avoidance response and extend the well-known participation of other members of BBX transcription factors for fine-tuning plant growth under shade.
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Proteínas de Arabidopsis , Arabidopsis , Regulación de la Expresión Génica de las Plantas , Hipocótilo , Luz , Factores de Transcripción , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Arabidopsis/fisiología , Arabidopsis/efectos de la radiación , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Hipocótilo/crecimiento & desarrollo , Hipocótilo/genética , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Ubiquitina-Proteína Ligasas/genética , Ubiquitina-Proteína Ligasas/metabolismo , Plantas Modificadas Genéticamente , Mutación/genética , Ácidos Indolacéticos/metabolismo , Fotoperiodo , Transducción de Señal/genéticaRESUMEN
Background: Because the benefits and risks of anticoagulation are still unknown in patients with atrial fibrillation (AF) and with chronic kidney disease (CKD) on hemodialysis. Objective: The aim of this study was to estimate whether the consumption of anticoagulants was associated with a difference in the frequency of thrombosis of any site, major bleeding and mortality, in adults with both diseases. Method: A retrospective cohort study was carried out in four high complexity centers. Patients older than 18 years with CKD on hemodialysis and non-valvular AF, with an indication for anticoagulation (CHA2DS-2VASc ≥ 2), were included. The primary outcome was the occurrence of: major bleeding, thrombotic event (cerebrovascular accident, acute myocardial infarction or venous thromboembolic disease) or death. Adjustment for confounding variables was performed using logistic regression. Results: From 158 patients included, 61% (n = 97) received an anticoagulant. The main outcome was found in 84% of those who received anticoagulation and 70% of those who did not (OR: 2.12, 95%CI: 0.98-4.57; after the adjusted analysis OR: 2.13, 95%CI: 1.04-4.36). Separate outcomes were bleeding in 52% vs. 34% (OR: 2.03; 95%CI: 1.05-3.93), thrombosis in 35% vs. 34% (OR: 1.03; 95%CI: 0.52-2-01) and death in 46% vs 41% (OR: 1.25; 95%CI: 0.65-2.38). Conclusions: The results of this study suggest an increased risk of bleeding in patients with AF and CKD on hemodialysis receiving anticoagulation, without a decrease in the risk of thrombotic events or all-cause mortality.
Antecedentes: Puesto que se desconocen el beneficio y los riesgos de la anticoagulación en pacientes con fibrilación auricular (FA) y enfermedad renal crónica (ERC) terminal en hemodiálisis. Objetivo: El objetivo de este estudio fue estimar si el uso de anticoagulantes se asociaba con una diferencia en la frecuencia de trombosis de cualquier sitio, hemorragia mayor y mortalidad en adultos con coexistencia de ambas patologías. Método: Se realizó un estudio de cohorte retrospectivo en cuatro centros de alta complejidad. Se incluyeron mayores de 18 años con ERC en hemodiálisis y FA no valvular, con indicación de anticoagulación (CHA2DS2VASc ≥ 2). El desenlace primario fue la ocurrencia de sangrado mayor, evento trombótico (accidente vascular cerebral, infarto agudo al miocardio o enfermedad tromboembólica venosa) o muerte. Se realizó ajuste por variables de confusión por regresión logística. Resultados: De los 158 pacientes incluidos, el 61% (n = 97) recibieron anticoagulante. El desenlace principal se encontró en el 84% de quienes recibieron anticoagulación y en el 70% de quienes no la recibieron (OR: 2.12, IC95%: 0.98-4.57; luego del ajuste OR: 2.13, IC95%: 1.04-4.36). De los desenlaces mayores se presentaron sangrado en el 52% vs. el 34% (OR: 2.03; IC95%: 1.05-3.93), trombosis en el 35% vs. el 34% (OR: 1.03; IC95%: 0.52-2.01) y muerte en el 46% vs. el 41% (OR: 1.25; IC95%: 0.65-2.38). Conclusiones: Los resultados de este estudio sugieren un incremento en el riesgo de sangrado en los pacientes con FA y ERC en hemodiálisis que reciben anticoagulación, sin disminución del riesgo de eventos trombóticos ni de muerte.
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Traditionally, the exogenous control of gaze by external saliencies and the endogenous control of gaze by knowledge and context have been viewed as competing systems, with late infancy seen as a period of strengthening top-down control over the vagaries of the input. Here we found that one-year-old infants control sustained attention through head movements that increase the visibility of the attended object. Freely moving one-year-old infants (n = 45) wore head-mounted eye trackers and head motion sensors while exploring sets of toys of the same physical size. The visual size of the objects, a well-documented salience, varied naturally with the infant's moment-to-moment posture and head movements. Sustained attention to an object was characterized by the tight control of head movements that created and then stabilized a visual size advantage for the attended object for sustained attention. The findings show collaboration between exogenous and endogenous attentional systems and suggest new hypotheses about the development of sustained visual attention.
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Juego e Implementos de Juego , Postura , Lactante , Humanos , Percepción VisualRESUMEN
A polymeric photosensitizer was synthesized through covalent attachment of the natural photosensitizer 6-carboxypterin (Cap) to a poly(allylamine hydrochloride) (PAH) polymer. The optimization of the functionalization steps and purification procedure is described. The overall yield of the functionalization reaction was 67% to generate the modified polymer (PAH-Cap), featuring a Cap substitution degree of approximately 1% and advantageous spectroscopic properties. Photosensitizing properties of PAH-Cap were observed to occur via both photooxidation mechanisms, i.e., type I and type II. This feature was demonstrated using a biologically relevant target molecule, 2'-deoxyguanosine (dG). The spectroscopic, photophysical, and photochemical behaviors in aqueous environments were studied and compared to Cap. To explore possible further relevant biological applications, experiments with PAH-Cap and dG were carried out at physiological pH. PAH-Cap can generate singlet molecular oxygen and initiate an electron transfer process at pH 7 in air-saturated solutions upon UVA irradiation. Moreover, based on its spectroscopic features, visible light can be used to initiate the photooxidation of biological compounds in water, with many interesting advantages compared to free Cap and other related pteridines. These advantages include an enhancement of the photosensitizing effect at physiological pH and the potential of PAH-Cap for its use as a building block in supramolecular assemblies. The functionalization strategy hereby described can be employed for the preparation of robust photoactive polymers with great potential for its application in photodynamic therapy (PDT) and disinfection technologies.
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Fotoquimioterapia , Fármacos Fotosensibilizantes , Poliaminas , Pterinas , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/química , Fotoquimioterapia/métodos , Concentración de Iones de Hidrógeno , Polímeros/química , Oxígeno Singlete/químicaRESUMEN
BACKGROUND: The development and fine-tuning of biotechnological processes for fish oil extraction constitute a very important focus to contribute to the development of a food industry based on fish consumption. This work lies in a comparative analysis of the oil extraction yield of Myliobatis goodei livers using free and immobilized enzymes. RESULTS: An immobilized biocatalyst was designed from the cell-free extract of a Bacillus sp. Mcn4. A complete factorial design was used to study the components of the bacterial culture medium and select the condition with the highest titers of extracellular enzymatic activities. Wheat bran had a significant effect on the culture medium composition for enzymatic production. The immobilized biocatalyst was designed by covalent binding of the proteins present in the cocktail retaining a percentage of different types of enzymatic activities (Mult.Enz@MgFe2 O4 ). Among the biocatalyst used, Alcalase® 2.4 L and Purazyme® AS 60 L (free commercial proteases) showed extraction yields of 87.39% and 84.25%, respectively, while Mult.Enz@MgFe2 O4 achieved a better one of 89.97%. The oils obtained did not show significant differences in their physical-chemical properties while regarding the fatty acid content, the oil extracted with Purazyme® AS 60 L showed a comparatively lower proportion of polyunsaturated fatty acids. CONCLUSIONS: Our results suggest that the use of by-products of M. goodei is a valid alternative and encourages the use of immobilized multienzyme biocatalysts for the treatment of complex substrates in the fishing industry. © 2023 Society of Chemical Industry.
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Enzimas Inmovilizadas , Lipasa , Hidrólisis , Lipasa/química , Enzimas Inmovilizadas/química , Aceites de Pescado/metabolismo , Hígado/metabolismoRESUMEN
Resumen: El objetivo de este trabajo fue evaluar los factores explicativos de la respuesta inmune humoral en adultos mayores de establecimientos de estancia prolongada de Buenos Aires, Argentina, hasta 180 días post vacunación. Se utilizó un diseño de cohorte abierta, prospectiva, multicéntrica, con voluntarios que recibieron dos dosis de vacunas Sputnik V, Sinopharm o AZD1222. Se analizaron muestras de plasma en los tiempos 0, 21 días post primera dosis, 21 días post segunda dosis, 120 y 180 días post primera dosis. Se ajustaron modelos lineales marginales y aditivos generalizados mixtos para evaluar el comportamiento de la concentración de anticuerpos IgG anti-Spike en el tiempo según grupo de exposición (naïve/no-naïve) y vacuna. Las covariables analizadas fueron: ocurrencia de brote de COVID-19 en establecimientos de estancia prolongada y comorbilidades. Se incluyeron en el análisis 773 participantes con una mediana de edad de 83 años (RIQ: 76-89). Al final del estudio, los niveles de anticuerpos del grupo naïve: Sinopharm fueron significativamente menores que el resto de los grupos (p < 0,05); los del no-naïve: Sinopharm resultaron similares a los naïve que recibieron AZD1222 (p = 0,945) o Sputnik V (p = 1). Los participantes expuestos a brotes en establecimientos de estancia prolongada presentaron niveles de anticuerpos significativamente mayores, independientemente del grupo de exposición y la vacuna (p < 0,001). Concluimos que la exposición previa a COVID-19, el tipo de vacuna y la pertenencia a un establecimiento de estancia prolongada con antecedente de brote son factores a considerar frente a futuros eventos epidémicos con dinámicas de transmisión y mecanismos inmunológicos similares al COVID-19, en poblaciones similares a la analizada en este trabajo.
Abstract: This study evaluated the explanatory factors of humoral immune response in older adults admitted to long-term care institutions in Buenos Aires, Argentina, up to 180 days after vaccination. An open-label, prospective, multicenter cohort study was conducted with volunteers who received two doses of the Sputnik V, Sinopharm, or AZD1222 vaccines. Plasma samples were analyzed at 0 and 21 days after the first dose, 21 days after the second dose, and 120 and 180 days after the first dose. Marginal linear models and generalized additives mixed models were adjusted to determine the behavior of anti-spike IgG antibody concentration over time according to exposure group (naïve/no-naïve) and vaccine. Occurrence of an outbreak of COVID-19 in long-term care institutions and comorbidities were the covariates analyzed. A total of 773 participants were included, with a mean age of 83 years (IQR: 76-89). Results showed that antibody levels in the naïve: Sinopharm group were significantly lower to the other groups (p < 0.05). Antibody levels in the no-naïve: Sinopharm group were similar to those in the naïve group who received AZD1222 (p = 0.945) or Sputnik V (p = 1). Participants exposed to outbreaks in long-term care institutions had significantly higher antibody levels, regardless of exposure group and vaccine (p < 0.001). In conclusion, previous exposure to COVID-19, type of vaccine, and admittance into a long-term care institution with a history of outbreaks are factors to be considered in future epidemic events with transmission dynamics and immunological mechanisms similar to COVID-19, in populations similar to the one analyzed.
Resumo: Este estudo teve como objetivo avaliar os fatores explicativos da resposta imune humoral em idosos em instituições de longa permanência em Buenos Aires, Argentina, até 180 dias após a vacinação. Foi realizado um estudo de coorte aberto, prospectivo e multicêntrico, com voluntários que receberam duas doses das vacinas Sputnik V, Sinopharm ou AZD1222. As amostras de plasma foram analisadas nos tempos 0, 21 dias após a primeira dose, 21 dias após a segunda dose, 120 e 180 dias após a primeira dose. Os modelos lineares marginais e os aditivos generalizados mistos foram ajustados para determinar o comportamento da concentração de anticorpos IgG anti-Spike ao longo do tempo de acordo com o grupo de exposição (naïve/no-naïve) e vacina. As covariáveis analisadas foram ocorrência de pico de COVID-19 nas instituições de longa permanência e comorbidades. Foram incluídos 773 participantes, com média de idade de 83 anos (IIQ: 76-89). Os resultados apontaram níveis de anticorpos do grupo naïve: Sinopharm significativamente mais baixos do que os outros grupos (p < 0,05); e as variáveis do grupo no-naïve: Sinopharm foram semelhantes à do grupo naïve que recebeu AZD1222 (p = 0,945) ou Sputnik V (p = 1). Os participantes expostos a picos nas instituições de longa permanência apresentaram níveis de anticorpos significativamente maiores, independentemente do grupo de exposição e da vacina (p < 0,001). Conclui-se que a exposição prévia à COVID-19, tipo de vacina e adesão a uma instituição de longa permanência com histórico de pico são fatores a serem considerados em futuros eventos epidêmicos com dinâmica de transmissão e mecanismos imunológicos semelhantes à COVID-19, em populações semelhantes à analisada neste trabalho.
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Water monitoring faces challenges that are driven by the infrastructure, protection, financial resources, science and innovation policies, among others. A modular, low-cost, fully open-source and small-sized Unmanned Surface Vessel (USV) called EMAC-USV (EMAC: Estación de Monitoreo Ambiental Costero), is proposed for monitoring bathymetry and water quality parameters (i.e. temperature, suspended solids concentration and hydrocarbon concentration) in complex water scenarios. A detailed description of each part of the platform as well as all electronic connections and functioning is presented.The field works were carried out in two small waste stabilization ponds and in a portion of the main tidal channel of the Bahía Blanca port. The EMAC-USV is the result of a cautious design, regarding the balancing performance, communications, payload capacity, among others.
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Resumen Objetivo: a la luz de los enfoques y estrategias de promoción de la salud propuesto en la Carta de Ottawa, avalados por la Organización Mundial de la Salud, se analizó cómo las autoridades sanitarias nacionales de Colombia, Brasil y México, que tienen sistemas de salud estructurados de manera distinta, conceptualizan y orientan la promoción de la salud. Metodología: análisis documental de información oficial de las dependencias encargadas de promoción de la salud en cada país; posteriormente, se hizo un análisis de coherencia en torno a ese concepto. Resultados: hay distintos niveles de coherencia respecto a la promoción de la salud: en Colombia el concepto se transmuta en gestión del riesgo individual a través de los documentos que implementan el Plan Decenal de Salud Pública; en Brasil el concepto de promoción de la salud se aplica coherentemente, aunque las prioridades operativas están enfocadas en aspectos individuales, además, cada Estado y municipio lo implementa de acuerdo con sus necesidades y capacidades; en México la promoción de la salud está institucionalizada, pero el acceso de los ciudadanos al servicio depende del aseguramiento y la agencia individual. Conclusiones: la promoción de la salud se hace en un marco de prestación de servicios de salud enfocados en el control del riesgo individual. Oficialmente los tres países evidenciaron coherencia con los postulados de promoción de la salud expuestos en la Carta de Ottawa, sin una adecuada coherencia en su implementación.
Abstract Objective: In light of the health promotion approaches and strategies proposed in the Ottawa Charter, endorsed by the World Health Organization, it was analyzed how the national health authorities of Colombia, Brazil and Mexico, which have health systems structured differently, conceptualize and guide health promotion. Methodology: Documentary analysis of official information from the agencies in charge of health promotion in each country. Subsequently, a coherence analysis around this concept was carried out. Results: There are different levels of coherence regarding health promotion: in Colombia the concept is transmuted into individual risk management through the documents that implement the Ten-Year Public Health Plan; in Brazil, the concept of health promotion is applied coherently although operational priorities are focused on individual aspects, and each state and municipality implements it according to their needs and capabilities; in Mexico, health promotion is institutionalized, but the access of citizens to the service depends on insurance and individual agency. Conclusions: Health promotion is done within a framework of health service provision focused on individual risk control. Officially, the three countries showed coherence with the health promotion postulates set out in the Ottawa Charter, without adequate coherence in its implementation.
Resumo Objetivo: À luz dos enfoques e estratégias de promoção da saúde propostas na Carta de Ottawa, endossada pela Organização Mundial da Saúde, foi analisado como as autoridades nacionais de saúde da Colômbia, Brasil e México, que possuem sistemas de saúde estruturados de forma diferenciada, conceituam e orientam promoção de saúde. Metodologia: Análise documental de informações oficiais dos órgãos responsáveis pela promoção da saúde de cada país; posteriormente, foi feita uma análise de coerência em torno desse conceito. Resultados: Há diferentes níveis de coerência em relação à promoção da saúde: na Colômbia o conceito se transmuta em gestão de risco individual por meio dos documentos que implementam o Plano Decenal de Saúde Pública; No Brasil, o conceito de promoção da saúde é aplicado de forma consistente, embora as prioridades operacionais sejam focadas em aspectos individuais, além disso, cada estado e município implementa de acordo com suas necessidades e capacidades; No México, a promoção da saúde é institucionalizada, mas o acesso dos cidadãos ao serviço depende de seguro e agência individual. Conclusões: A promoção da saúde é feita dentro de uma estrutura de prestação de serviços de saúde com foco no controle de risco individual. Oficialmente, os três países mostraram-se coerentes com os postulados de promoção da saúde previstos na Carta de Ottawa, sem a devida coerência em sua implementação.
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The current study provides a comprehensive look of the adsorption process of Candida rugosa lipase (CRL) on Ca2Fe2O5 iron oxide nanoparticles (NPs). Protein-support interactions were identified across a broad range of pH and ionic strengths (mM) through a response surface methodology, surface charge determination, and spectroscopic and in silico analyses. The maximum quantity of immobilized protein was achieved at an ionic strength of 50 mM and pH 4. However, this condition did not allow for the greatest hydrolytic activity to be obtained. Indeed, it was recorded at acidic pH, but at 150 mM, where evaluation of the recovered activity revealed hyperactivation of the enzyme. These findings were supported by adsorption isotherms performed under different conditions. Based on zeta potential measurements, electrostatic interactions contributed differently to protein-support binding under the conditions tested, showing a strong correlation with experimentally determined immobilization parameters. Raman spectra revealed an increase in hydrophobicity around tryptophan residues, whereas the enzyme immobilization significantly reduced the phenylalanine signal in CRL. This suggests that this residue was involved in the interaction with Ca2Fe2O2 and molecular docking analysis confirmed these findings. Fluorescence spectroscopy showed distinct behaviors in the CRL emission patterns with the addition of Ca2Fe2O5 at pH 4 and 7. The calculated thermodynamic parameters indicated that the contact would be mediated by hydrophobic interactions at both pHs, as well as by ionic ones at pH 4. In this approach, this work adds to our understanding of the design of biocatalysts immobilized in iron oxide NPs.
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Candida , Candida/enzimología , Concentración de Iones de Hidrógeno , Lipasa/metabolismo , Concentración Osmolar , Enzimas Inmovilizadas/metabolismo , Simulación del Acoplamiento Molecular , Interacciones Hidrofóbicas e Hidrofílicas , Nanopartículas del Metal/químicaRESUMEN
The presence of microplastics (MPs) in the fish gastrointestinal tract has been documented in several studies. However, it is unclear whether this ingestion is active or passive and whether it affects feeding activity in natural environments. In this study, three sites with different anthropogenic pressure were selected from the Bahia Blanca estuary, Argentina, and the small zooplanktivorous pelagic fish Ramnogaster arcuata was used to evaluate MP ingestion and its effect on specie's trophic activity. We analyzed the zooplanktonic composition, levels, and types of MPs in both the environment and the stomach contents of R. arcuata. Moreover, we assessed the trophic behavior of R. arcuata to determine electivity, stomach fullness, and vacuity indexes. The results showed that despite the availability of prey in the environment, 100 % of the specimens ingested MPs, and their levels and characteristics were different according to the site. Stomach contents at sites related to harbor activities presented the lowest MPs concentrations, most of them were paint fragments, with the smallest sizes and a low diversity of colors. The highest MP ingestions were found near the principal sewage discharge, being mostly microfibers, followed by microbeads, and with a greater variety of colors. Electivity indices showed that R. arcuata has a passive or active ingestion according to the size and shape of MPs. In addition, the lowest stomach fullness index and the highest vacuity index values were associated with the highest level of MP ingestion near the sewage discharge. Altogether, these results demonstrate a negative effect of MPs in the feeding activity of R. arcuata and help to elucidate some mechanisms by which these particles are ingested by a bioindicator fish used in South America.
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Microplásticos , Contaminantes Químicos del Agua , Animales , Plásticos , Aguas del Alcantarillado , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/análisis , Peces , Brasil , Ingestión de Alimentos , Monitoreo del AmbienteRESUMEN
Concern about atmospheric microplastic (MP) contamination has increased in recent years. This study assessed the abundance of airborne anthropogenic particles, including MPs, deposited in rainfall in Bahia Blanca, southwest Buenos Aires, Argentina. Rainwater samples were collected monthly from March to December 2021 using an active wet-only collector consisting of a glass funnel and a PVC pipe that is only open during rain events. Results obtained show that all rain samples contained anthropogenic debris. The term "anthropogenic debris" is used to refer to the total number of particles as not all the particles found could be determined as plastic. Among all the samples, an average deposition of 77 ± 29 items (anthropogenic debris) m-2d-1 was found. The highest deposition was observed in November (148 items m-2d-1) while the lowest was found in March (46 items m-2d-1). Anthropogenic debris ranged in size from 0.1 mm to 3.87 mm with the most abundant particles being smaller than 1 mm (77.8%). The dominant form of particles found were fibers (95%), followed by fragments (3.1%). Blue color predominated (37.2%) in the total number of samples, followed by light blue (23.3%) and black (21.7%). Further, small particles (<2 mm), apparently composed of mineral material and plastic fibers, were recognized. The chemical composition of suspected MPs was examined by Raman microscopy. The analysis of µ-Raman spectra confirmed the presence of polystyrene, polyethylene terephthalate, and polyethylene vinyl acetate fibers and provided evidence of fibers containing industrial additives such as indigo dye. This is the first assessment of MP pollution in rain in Argentina.
RESUMEN
A new decyl chain [-(CH2)9CH3] riboflavin conjugate has been synthesized and investigated. A nucleophilic substitution (SN2) reaction was used for coupling the alkyl chain to riboflavin (Rf), a model natural photosensitizer. As expected, the alkylated compound (decyl-Rf) is significantly more lipophilic than its precursor and efficiently intercalates within phospholipid bilayers, increasing its fluorescence quantum yield. The oxidative damage to lipid membranes photoinduced by decyl-Rf was investigated in large and giant unilamellar vesicles (LUVs and GUVs, respectively) composed of different phospholipids. Using a fluorogenic probe, fast radical formation and singlet oxygen generation was demonstrated upon UVA irradiation in vesicles containing decyl-Rf. Photosensitized formation of conjugated dienes and hydroperoxides, and membrane leakage in LUVs rich in poly-unsaturated fatty acids were also investigated. The overall assessment of the results shows that decyl-Rf is a significantly more efficient photosensitizer of lipids than its unsubstituted precursor and that the association to lipid membranes is key to trigger phospholipid oxidation. Alkylation of hydrophilic photosensitizers as a simple and general synthetic tool to obtain efficient photosensitizers of biomembranes, with potential applications, is discussed.
Asunto(s)
Fosfolípidos , Fármacos Fotosensibilizantes , Riboflavina , Liposomas Unilamelares , AlquilaciónRESUMEN
This is the first research that extensively compiles all the available scientific literature on the presence of trace metals (TMs), persistent organic pollutants (POPs), and plastic debris in Chondrichthyan species inhabiting South America (including the Atlantic and Pacific Oceans), providing an insight into Chondrichthyans as bioindicators of pollutants as well as the impacts of pollutant exposure on the organisms. Seventy-three studies were published in South America between 1986 and 2022. While 68.5% focused on TMs, 17.8% on POPs, and 9.6% on plastic debris. Brazil and Argentina were at the top in terms of the number of publications; however, there is an absence of information regarding pollutants for Chondrichthyans in Venezuela, Guyana, and French Guiana. Of the 65 Chondrichthyan species reported, 98.5% belong to the Elasmobranch group, and 1.5% from the Holocephalans. Most studies focused on Chondrichthyans of economic importance, and the most analyzed organs were the muscle and liver. There is a lack of studies on Chondrichthyan species with low economic value and critical conservation status. Due to their ecological relevance, distribution, accessibility, high trophic position, capacity to accumulate high levels of pollutants, and the number of studies published, Prionace glauca and Mustelus schmitii seem to be adequate to serve as bioindicators. For TMs, POPs, and plastic debris there is a lack of studies focusing on the pollutant levels as well as their effect on Chondrichthyans. Future research reporting TMs, POPs, and plastic debris occurrences in Chondrichthyan species are required in order to increase the scarce databases about pollutants in this group, with a clear need for further research on the responses of chondrichthyans to pollutants, as well as making inferences about the potential risks to the ecosystems and human health.
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Contaminantes Químicos del Agua , Contaminantes del Agua , Humanos , Biomarcadores Ambientales , Ecosistema , Contaminantes Químicos del Agua/análisis , Plásticos , Brasil , Monitoreo del AmbienteRESUMEN
This study evaluated the occurrence and distribution of largely known pollutants (Ag, Cd, Cu, Cr, Hg, Ni, Pb, Pd, and Zn), as well as emerging ones (Li, and V) in the water dissolved fraction, suspended particulate matter, and surface sediments from the lower course of the Negro River, Argentina. There are scarce preceding data on inorganic pollution in the entire watershed and, in the case of the emerging pollutants, there are almost no studies performed worldwide. Sampling was conducted in 2019 at six sampling sites, three of them mostly river dominated and the rest under marine domain. The samples were subjected to an acid digestion in a microwave digester, and analyzed using an Inductively Coupled Plasma Atomic Emission Spectrometer. Results: revealed that Cu, Li, V, and Zn were always on the top four of the highest average metal concentrations in water and sediment fractions. The pollution assessment indicated that the watershed might be exposed to anthropogenic pollution, as over 60% of Cu and Zn, and over 85% of Hg in water dissolved samples from the marine dominated sites were above the maximum recommended values from guidelines. The multivariate analyses characterized the watershed into two clusters, with metals in the sediment fraction mainly contributing to the uppermost sites. Indeed, sedimentary Cu and Zn background enrichment indices pointed out a moderate pollution of the river dominated sites. This study highlights the relevance of an integrative approach in metal pollution evaluation, as the results denoted a progressive deterioration of the watershed, affecting the water quality of the lower course of the Negro River and its adjacent coastal zone. Overall, these results contribute to a more complete evaluation of the potential to fulfill the Sustainable Development Goals, with implications for future treatment strategies to enhance the environmental quality of the area.
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Contaminantes Ambientales , Mercurio , Metales Pesados , Contaminantes Químicos del Agua , Argentina , China , Monitoreo del Ambiente/métodos , Contaminantes Ambientales/análisis , Sedimentos Geológicos/análisis , Litio/análisis , Mercurio/análisis , Metales Pesados/análisis , Medición de Riesgo , Ríos , Contaminantes Químicos del Agua/análisis , Calidad del AguaRESUMEN
Organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) threaten the environment due to their wide environmental resistance. Environmental paradigms coexist along the Negro River (NR) in Argentina, South America, which flows to the sea below the latitude of 40o S; however, this is the first environmental assessment of OCPs and PAHs in water of the NR for more than 15 years. With 21 sampling sites covering a range of 600 km of river extension, we assessed 16 OCPs and 16 PAHs in suspended particulate material (SPM) with regard to their levels, seasonality, sources, and potential biological risk assessment. Using gas chromatography-mass spectrometry and gas chromatography coupled with electron capture detection, we found an overall mean value for Σ16 OCPs of 648.56 ng. g-1, d.w. Despite a ban spanning 25 years, an increasing trend of accumulation of hexachlorocyclohexanes (HCHs) and endosulfan was shown in the lower valley. The É-HCH/ɤ-HCH and ß-HCH/(É + ɤ)-HCH ratios indicated a prevalent usage of technical HCH over lindane and recent HCH inputs. The most abundant compound, α-endosulfan, averaged 141.64 ng. g-1, d.w. and DDX (Σ 4,4'-DDE, 4,4'-DDD, and 4,4'-DDT) averaged 99.98 ng. g-1, d.w. Winter OCP loads in the NR reflected the runoff of the heaviest pesticide application period. We estimated the total discharge of DDT into the Atlantic ocean was 96 g.day-1, added to 458 g of HCHs and 257 g of endosulfans (É + ß + epoxide) adsorbed by the SPM. PAHs occurred widely along the river (38.83 ± 43.52 µg. g-1) and the highest levels coincided with locations with marked anthropogenic-related activity, such as petroleum/gas exploitation facilities. Risk quotient analysis showed a low risk posed by OCPs, but a high risk of potential effects on biota posed by the PAHs, highlighting the need for mitigation measures.
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Hidrocarburos Clorados , Plaguicidas , Hidrocarburos Policíclicos Aromáticos , Contaminantes Químicos del Agua , Humanos , Argentina , Endosulfano/análisis , Monitoreo del Ambiente , Cromatografía de Gases y Espectrometría de Masas , Hidrocarburos Clorados/análisis , Material Particulado/análisis , Plaguicidas/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Medición de Riesgo , Ríos/química , Contaminantes Químicos del Agua/análisisRESUMEN
Microplastics (MPs) from the coastal areas of a highly anthropised estuary were sampled to assess their distribution in coastal sediments and their role as potential vectors of pollution. The average MP density was 1693 ± 2315 MPs/kg, which mainly accumulated in the high tide and storm berm areas of the beach. The Microplastic Pollution Index (MPPI), Microplastic Impact Coefficient (CMPI), Hierarchical Cluster Analysis and Principal Component Analysis revealed spatial variation in MPs pollution. High-density polyethylene plastic pellets were abundant at two beaches (192 ± 218 MPs/kg sediment). Furthermore, the presence of sorbed chemicals on pellets was assessed through GC-MS, showing 0.95 ± 0.09 ng/g of ∑7OCPs, 4.03 ± 0.89 ng/g of ∑7PCBs, 108.76 ± 12.88 ng/g of ∑16 PAHs and 122.79 ± 11.13 g/g of ∑29 PAHs. The sorption capacity of plastics, combined with their abundance, poses an environmental concern and also highlights their suitability as indicators of chemical exposure.
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Plásticos , Contaminantes Químicos del Agua , Plásticos/análisis , Microplásticos/análisis , Estuarios , Argentina , Brasil , Monitoreo del Ambiente , Contaminación Ambiental/análisis , Contaminantes Químicos del Agua/análisis , Sedimentos Geológicos/análisisRESUMEN
This paper provides the first evidence of debris pollution, including plastic, in juvenile Magellanic penguins (Spheniscus magellanicus) found stranded on the Atlantic coast of southern Buenos Aires Province, Argentina. Macro-, meso- and microparticles of anthropogenic origin were observed in 100 % of the studied birds, with debris abundance ranging between 33 and 200 items/bird. Microparticles represented 91 % of the total debris and 97 % of them were fibers. Black particles were the most abundant (30 %), followed by transparent (26 %), blue (14 %), yellow (10.3 %), and red (10 %). Infrared and Raman spectroscopy identified 62.7 % of the total particles as plastics, with polypropylene (27.8 %) and polyester (21.6 %) being the most abundant polymers. Semi-synthetic cellulosic fibers, metallic particles, and pigments were also found. The presence of metallic microparticles was suggested for the first time in penguins. Stranded juvenile Magellanic penguins are proposed as promising bioindicators of plastic pollution in the South Atlantic.