Antioxidant and Photoprotective Metabolites of Bunodophoron melanocarpum, A Lichen from the Andean Páramo

Background: Oxidative stress caused by exposure to ultraviolet radiation has been associated with dermal problems, including skin cancer. In this study, we determined the photoprotective and antioxidant activity of isolated metabolites from the lichen Bunodophoron melanocarpum (Sphaerophoraceae) to find new sunscreens prototypes. Methods: The constituents of B. melanocarpum were isolated by phytochemical methods and their structures were determined by spectroscopy (IR, 1D and 2D NMR). Antioxidant activity was measured by scavenging DPPH free radicals (EC50), ferric reducing power (FRP), and inhibition of lipid peroxidation (% ILP). The photoprotective capacity against ultraviolet(UVA and UVB) radiations was determined in vitro by calculating their sun protection factor(SPF), critical wavelength and UVA ratio and these values were compared against commercial sunscreens. The lipophilicity and possible skin penetration to the lipid-rich stratum corneum of the isolates, was determined by calculating their octanol/water partition coefficients (Log P) and Gibbs free energy of transfer (ΔtG0 ). Results: Sphaerophorin (1), everninic acid (2), sphaerophorol carboxylic acid (3) and friedelin(4) were isolated from B. melanocarpum. Orsellinic acid-type compounds 1 and 3 are dual agents with antioxidant capacity as free radical scavengers (EC50= 0.0857 and 0.1828 mol compound /mol DPPH•, respectively) and photoprotective properties particularly against UVB radiation(SPF 25.78 ± 0.53 and 22.00 ± 1.03, respectively). In addition, they had lipophilicity (Log P 7.07 ±0.64 and 4.03 ± 0.32, respectively) and ΔtG0 (-40.32 ± 3.67 and -22.97 ± 1.82 kJmol-1, respectively)suitable to act on the skin. Conclusion: Sphaerophorin (1) and sphaerophorol carboxylic acid (3) are dual agents with antioxidant and UVB photoprotective properties and are also lipophilic substances that spontaneously would diffuse across the skin

Acrylic bone cements modified with graphene oxide: Mechanical, physical, and antibacterial properties

Bacterial infections are a common complication after total joint replacements (TJRs), the treatment of which is usually based on the application of antibiotic-loaded cements; however, owing to the increase in antibiotic-resistant microorganisms, the possibility of studying new antibacterial agents in acrylic bone cements (ABCs) is open. In this study, the antibacterial effect of formulations of ABCs loaded with graphene oxide (GO) between 0 and 0.5 wt. % was evaluated against Gram-positive bacteria: Bacillus cereus and Staphylococcus aureus, and Gram-negative ones: Salmonella enterica and Escherichia coli. It was found that the effect of GO was dependent on the concentration and type of bacteria: GO loadings ≥0.2 wt. % presented total inhibition of Gram-negative bacteria, while GO loadings ≥0.3 wt. % was necessary to achieve the same effect with Gram-positives bacteria. Additionally, the evaluation of some physical and mechanical properties showed that the presence of GO in cement formulations increased wettability by 17%, reduced maximum temperature during polymerization by 19%, increased setting time by 40%, and increased compressive and flexural mechanical properties by up to 17%, all of which are desirable behaviors in ABCs. The formulation of ABC loading with 0.3 wt. % GO showed great potential for use as a bone cement with antibacterial properties

Discussion focus groups : a strategy for research on sexual health with adolescents who have lived on the streets of Medellín, Colombia

RESUMEN: La intención de este artículo es evidenciar la importancia de los grupos focales de discusión como estrategia metodológica para la recolección de información en el trabajo con adolescentes institucionalizados con experiencia de vida en calle y, al mismo tiempo, mostrar su valor en el abordaje de la salud sexual con esta población, en tanto que permite una interacción flexible y reflexiva entre investigadores y participantes, así como de los participantes entre sí. El valor de esta estrategia metodológica es sustentado en este artículo mediante testimonios y resultados obtenidos durante su implementación en el estudio llevado a cabo con adolescentes institucionalizados entre 2013 y 2014 en Medellín. Se espera con este reducir las creencias de profesionales con respecto a las limitaciones de la estrategia para abordar temáticas relacionadas con la salud sexual de este grupo poblacional. Los resultados se articulan en cuatro categorías: conocimientos y percepciones sobre vih e its, salud sexual y reproductiva (ssr), el lenguaje en la ssr, y acceso y uso de las tecnologías de la información y la comunicación (tic). De esta manera, se deja de manifiesto el aporte y potencial de la estrategia para el abordaje del tema y para el acercamiento e interacción con adolescentes con experiencia de vida en calle.ABSTARCT: This paper aims to show the importance of discussion focus groups as a methodological strategy for the compilation of information in studies with institutionalized adolescents who have lived on the streets. At the same time, it aims to show the value of this technique in approaching the topic of sexual health with this population, since it allows for flexible and reflexive researcher-participant and participant-participant interaction. The value of this methodological strategy is supported in this article through accounts and results obtained during the implementation of a study conducted with institutionalized adolescents between 2013 and 2014. We expect these results will reduce the beliefs of professionals regarding the limitations of the strategy to address issues related to the sexual health of this type of population. The results are divided into four categories: knowledge and perceptions of HIV and STIs, sexual and reproductive health (SRH), the language used in SRH, and access to and use of information and communications technology (ICT). Thus, this paper clearly shows the contribution and potential of the strategy for addressing the issue, approaching and interacting with adolescents who have lived on the street

Propuesta regulatoria para la sustituci?n del mecanismo de declaraci?n de precios de gas natural

El esquema de la Ley de Concesiones El?ctricas (LCE) consiste en un pool obligatorio bajo costos auditados. Este simula competencia, en tanto el precio spot es igual al costo variable de la ?ltima central que despacha. El DS N? 016-2000-EM estableci? una excepci?n, permitiendo las declaraciones no auditables a las Generadoras que usan GN bajo el Mecanismo de Declaraci?n de Precios (MDP). Inflexibilidades contractuales en el Suministro, Transporte y Distribuci?n de GN hacen que los costos asociados se comporten como fijos. Despachar o no despachar se convierte en una decisi?n cr?tica para la Generadora, puesto que si no despacha, sus costos comprenden la remuneraci?n a precio spot de los retiros y el pago de los insumos no consumidos. Las conclusiones principales de la tesis son: - El MDP afecta la eficiencia asignativa del Mercado de Corto Plazo (MCP). Esto incentiva, entre otros, que el CMCP sea menor y el aumento del Cargo Prima RER. - La Opci?n Regulatoria escogida es aquella donde se hace variable el costo de los insumos, y se crea una bolsa con caracteres fiduciarios que contiene los compromisos contractuales. La nominaci?n se realiza por el COES optimizando y minimizando el costo de operaci?n. Las cantidades no utilizadas (minimizadas a trav?s de declaraciones del COES) son remuneradas a trav?s de un cargo

ACRATA: a novel electron transfer domain associated to apoptosis and cancer

BACKGROUND: Recently, several members of a vertebrate protein family containing a six trans-membrane (6TM) domain and involved in apoptosis and cancer (e.g. STEAP, STAMP1, TSAP6), have been identified in Golgi and cytoplasmic membranes. The exact function of these proteins remains unknown. METHODS: We related this 6TM domain to distant protein families using intermediate sequences and methods of iterative profile sequence similarity search. RESULTS: Here we show for the first time that this 6TM domain is homolog to the 6TM heme binding domain of both the NADPH oxidase (Nox) family and the YedZ family of bacterial oxidoreductases. CONCLUSIONS: This finding gives novel insights about the existence of a previously undetected electron transfer system involved in apoptosis and cancer, and suggests further steps in the experimental characterization of these evolutionarily related families

What Is the Support for Conspiracy Beliefs About COVID-19 Vaccines in Latin America? A Prospective Exploratory Study in 13 Countries

Conspiracy theories about COVID-19 began to emerge immediately after the first news about the disease and threaten to prolong the negative impact of the COVID-19 pandemic by limiting people’s willingness of receiving a life-saving vaccine. In this context, this study aimed to explore the variation of conspiracy beliefs regarding COVID-19 and the vaccine against it in 5779 people living in 13 Latin American countries (Argentina, Bolivia, Chile, Colombia, Cuba, Ecuador, El Salvador, Guatemala, Mexico, Paraguay, Peru, Uruguay and Venezuela) according to sociodemographic variables such as gender, age, educational level and source of information about COVID-19. The study was conducted during the COVID-19 pandemic between September 15 and October 25, 2021. The Spanish-language COVID-19 Vaccine Conspiracy Beliefs Scale (ECCV-COVID) and a sociodemographic survey were used. The results indicate that, in most countries, women, people with a lower educational level and those who receive information about the vaccine and COVID-19 from family/friends are more supportive of conspiracy ideas regarding the COVID-19 vaccine. In the case of age, the results vary by country. The analysis of the responses to each of the questions of the ECCV-COVID reveals that, in general, the countries evaluated are mostly in some degree of disagreement or indecision regarding conspiratorial beliefs about COVID-19 vaccines. The findings could help open further study which could support prevention and treatment efforts during the COVID-19 pandemic

Design and Cross-Cultural Invariance of the COVID-19 Vaccine Conspiracy Beliefs Scale (COVID-VCBS) in 13 Latin American Countries

"Aims: Over the past 2 years, the vaccine conspiracy beliefs construct has been used in a number of different studies. These publications have assessed the determinants and outcomes of vaccine conspiracy beliefs using, in some cases, pooled data from different countries, and compared the results across these contexts. However, studies often do not consider measurement invariance as a necessary requirement for comparative analyses. Therefore, the aim of this study was to develop and evaluate the crosscultural MI of the COVID-19 Vaccine Conspiracy Beliefs Scale (COVID-VCBS) in 12 Latin American countries. Methods: Confirmatory factor analysis, item response theory analysis and alignment method were applied to test measurement invariance in a large number of groups. Results: The COVID-VCBS showed robust psychometric properties and measurement invariance for both factor loadings and crosstabs. Also, a higher level of acceptance of conspiracy beliefs about vaccines is necessary to respond to higher response categories. Similarly, greater acceptance of conspiracy beliefs about COVID-19 vaccines was related to a lower intention to be vaccinated. Conclusion: The results allow for improved understanding of conspiracy beliefs about COVID-19 vaccines in the countries assessed; furthermore, they provide researchers and practitioners with an invariant measure that they can use in cross-cultural studies in Latin America. However, further studies are needed to test invariance in other countries, with the goal of developing a truly international measure of conspiracy beliefs about COVID-19 vaccines.

An In Silico Modeling Approach to Understanding the Dynamics of Sarcoidosis

BACKGROUND: Sarcoidosis is a polygenic disease with diverse phenotypic presentations characterized by an abnormal antigen-mediated Th1 type immune response. At present, progress towards understanding sarcoidosis disease mechanisms and the development of novel treatments is limited by constraints attendant to conducting human research in a rare disease in the absence of relevant animal models. We sought to develop a computational model to enhance our understanding of the pathological mechanisms of and predict potential treatments of sarcoidosis. METHODOLOGY/RESULTS: Based upon the literature, we developed a computational model of known interactions between essential immune cells (antigen-presenting macrophages, effector and regulatory T cells) and cytokine mediators (IL-2, TNFα, IFNγ) of granulomatous inflammation during sarcoidosis. The dynamics of these interactions are described by a set of ordinary differential equations. The model predicts bistable switching behavior which is consistent with normal (self-limited) and "sarcoidosis-like" (sustained) activation of the inflammatory components of the system following a single antigen challenge. By perturbing the influence of model components using inhibitors of the cytokine mediators, distinct clinically relevant disease phenotypes were represented. Finally, the model was shown to be useful for pre-clinical testing of therapies based upon molecular targets and dose-effect relationships. CONCLUSIONS/SIGNIFICANCE: Our work illustrates a dynamic computer simulation of granulomatous inflammation scenarios that is useful for the investigation of disease mechanisms and for pre-clinical therapeutic testing. In lieu of relevant in vitro or animal surrogates, our model may provide for the screening of potential therapies for specific sarcoidosis disease phenotypes in advance of expensive clinical trials

Network analysis of the relationships between conspiracy beliefs towards COVID-19 vaccine and symptoms of fear of COVID-19 in a sample of latin american countries

The present study examined how conspiracy beliefs about COVID-19 vaccines specifically relate to symptoms of fear of COVID-19 in a sample of four South American countries. A total of 1785 people from Bolivia, Colombia, Ecuador, and Peru participated, responding to a sociodemographic survey, the Fear of COVID-19 scale (FCV-19 S) and the Vaccine Conspiracy Beliefs Scale-COVID-19 (VCBS-COVID-19). Network analysis identified the most important symptoms of fear and conspiracy beliefs about COVID-19 vaccines (nodes) and the associations between them (edges). In addition, the robustness of the network of these indicators of centrality and the possible differences in the structure and connectivity of the networks between the four countries were evaluated. The results suggest that the nodes with the highest centrality were items 2 and 5 of the FCV-19 S and item 2 of the VCBS-COVID-19. Likewise, item 6 is the belief that most predicts conspiracy beliefs about vaccines against COVID-19; while item 6 was the symptom that most predicts fear of COVID-19. The findings strongly support cross-cultural similarities in the networks across the four countries rather than differences. Although it was expected that a higher presence of symptoms of fear of COVID-19 may lead people to compensate for their fear by believing in conspiratorial ideas about vaccines and, consequently, rejecting the COVID-19 vaccine, the results do not clearly show this relationship. This could lead other researchers to generate evidence to explain the differences between Latin American countries and countries in other contexts in terms of vaccination rates. This evidence could be useful to develop policies favoring vaccination against COVID-19 that are more contextualized to the Latin American region, characterized by social instability and economic recession during the pandemic