Temperature-Dependent Optical Properties of Oxidized Graphenes.

In this study, we investigate how changing important synthesis-related parameters can affect and control the optical characteristics of graphene oxide (GO) and reduced graphene oxide (rGO). These parameters include drying time and reduction time at two different temperatures. We obtain an understanding of their impact on optical transitions, optical bandgap, absorption coefficient, and absorbance spectrum width by analyzing these factors. Accordingly, GO has an optical bandgap of about 4 eV, which is decreased by the reduction process to 1.9 eV. Both GO and rGO display greater absorption in the visible spectrum, which improves photon capture and boosts efficiency in energy conversion applications. Additionally, our results show that GO and rGO have higher absorption coefficients than those previously reported for dispersions of exfoliated graphene. Defects in GO and rGO, as well as the presence of functional oxygen groups, are the main contributors to this increased absorption. Several measurements are carried out, including spectroscopic and morphological studies, to further support our findings.

Gene expression and cell culture assays reveal cheese isolate Lactococcus lactis MC5 may influence the virulence of Staphylococcus aureus.

Staphylococcus aureus (SA) can thrive in a wide variety of hosts and environments, causing clinical infections and foodborne intoxications. In Brazil, SA is commonly isolated from traditional soft cheeses, especially those prepared from unpasteurized milk. In this research, the isolate S. aureus SABRC1 was evaluated for virulence traits under different conditions, including co-inoculation with Lactococcus lactis MC5 (isolated from "Fresh Minas Cheese"), which produces antibacterial peptides. Results from experiments with Caco-2 culture indicated S. aureus SABRC1 was able to adhere (42.83 ± 1.79%) and to invade (48.57 ± 0.41%) the intestinal cells. On the other hand, L. lactis MC5 presented anti-staphylococcal activity as indicated by agar assays, and it was also able to antagonize intestinal cell invasion by S. aureus. Moreover, Reverse Transcriptase-PCR experiments showed virulence genes of S. aureus SABRC1 (hla, icaA and sea) were differentially expressed under diverse culture conditions, which included Brain Heart Infusion modified or not by the addition of glucose, sodium chloride, milk or cheese. This suggests the virulence of S. aureus SABRC1 is influenced by compounds commonly found in daily diets, and not only by its genetic repertoire, adding a novel level of complexity for controlling infection by this pathogen.

Process Development for the Spray-Drying of Probiotic Bacteria and Evaluation of the Product Quality.

Probiotics and prebiotics are of great interest to the food and pharmaceutical industries due to their health benefits. Probiotics are live bacteria that can confer beneficial effects on human and animal wellbeing, while prebiotics are types of nutrients that feed the beneficial gut bacteria. Powder probiotics have gained popularity due to the ease and practicality of their ingestion and incorporation into the diet as a food supplement. However, the drying process interferes with cell viability since high temperatures inactivate probiotic bacteria. In this context, this study aimed to present all the steps involved in the production and physicochemical characterization of a spray-dried probiotic and evaluate the influence of the protectants (simulated skim milk and inulin:maltodextrin association) and drying temperatures in increasing the powder yield and cell viability. The results showed that the simulated skim milk promoted higher probiotic viability at 80 °C. With this protectant, the probiotic viability, moisture content, and water activity (Aw) reduce as long as the inlet temperature increases. The probiotics' viability decreases conversely with the drying temperature. At temperatures close to 120 °C, the dried probiotic showed viability around 90%, a moisture content of 4.6% w/w, and an Aw of 0.26; values adequate to guarantee product stability. In this context, spray-drying temperatures above 120 °C are required to ensure the microbial cells' viability and shelf-life in the powdered preparation and survival during food processing and storage.

A Cross-Sectional Analysis of Self-Medication Patterns during the COVID-19 Pandemic in Ecuador.

Background and Objectives: Drug consumption is a widely developed practice around the world. However, sometimes medicines are acquired with or without prescription, a practice termed self-medication, which can have negative impacts on the health of the population. It has been observed that with the arrival of the coronavirus disease 2019 (COVID-19) pandemic, self-medicated drug consumption figures increased in several countries. To describe the patterns of medication, use and the prevalence of self-medication during the COVID-19 pandemic in inhabitants of the capital province of Pichincha, Ecuador. Materials and Methods: A descriptive, cross-sectional study was conducted based on a self-administered online questionnaire from April to June 2022, among residents of the province of Pichincha, Ecuador. Participants were invited through social networks (WhatsApp and Facebook). A total of 401 surveys were included in this study. Consumption patterns (prescription of and treatment with) of medicines during the pandemic were evaluated, as well as the prevalence of self-medication and variables that characterize the way of acquiring medicines. The Chi-square test was used to look for relationships between consumption patterns, self-medication, and the characteristics of the participants. Results: Most participants were female (53.4%), and 59.4% reported having had COVID-19. A total of 244 (60.9%) consumed medications during the pandemic, mostly for the purpose of treating the infection. About half (48.4%) self-medicated. The most used medications were paracetamol (87.3%) and ibuprofen (47.5%). Drugs consumption as a treatment and informal sources of information (TV, social networks, advice) were associated with the practice of self-medication (p < 0.05). Conclusions: A significant percentage of over-the-counter (OTC) and legal drug use was found to persist after the COVID-19 pandemic. Our findings highlight the effects that alternative forms of information sources other than medical personnel can have on drug consumption and self-medication practices.

Adsorption of Mercury on Oxidized Graphenes.

Graphene oxide (GO) and its reduced form, reduced graphene oxide (rGO), are among the most predominant graphene derivatives because their unique properties make them efficient adsorbent nanomaterials for water treatment. Although extra-functionalized GO and rGO are customarily employed for the removal of pollutants from aqueous solutions, the adsorption of heavy metals on non-extra-functionalized oxidized graphenes has not been thoroughly studied. Herein, the adsorption of mercury(II) (Hg(II)) on eco-friendly-prepared oxidized graphenes is reported. The work covers the preparation of GO and rGO as well as their characterization. In a further stage, the description of the adsorption mechanism is developed in terms of the kinetics, the associated isotherms, and the thermodynamics of the process. The interaction between Hg(II) and different positions of the oxidized graphene surface is explored by DFT calculations. The study outcomes particularly demonstrate that pristine rGO has better adsorbent properties compared to pristine GO and even other extra-functionalized ones.

Removal of mercury(II) from aqueous solution by partially reduced graphene oxide.

Mercury (Hg(II)) has been classified as a pollutant and its removal from aqueous sources is considered a priority for public health as well as ecosystem protection policies. Oxidized graphenes have attracted vast interest in water purification and wastewater treatment. In this report, a partially reduced graphene oxide is proposed as a pristine adsorbent material for Hg(II) removal. The proposed material exhibits a high saturation Hg(II) uptake capacity of 110.21 mg g-1, and can effectively reduce the Hg(II) concentration from 150 mg L-1 to concentrations smaller than 40 mg L-1, with an efficiency of about 75% within 20 min. The adsorption of Hg(II) on reduced graphene oxide shows a mixed physisorption-chemisorption process. Density functional theory calculations confirm that Hg atom adsorbs preferentially on clean zones rather than locations containing oxygen functional groups. The present work, therefore, presents new findings for Hg(II) adsorbent materials based on partially reduced graphene oxide, providing a new perspective for removing Hg(II).

Optimización de la protección en radiología y cardiología intervencionista pediatrica en América Latina y el Caribe (OPRIPALC) / Optimization of protection in pediatric interventional cardiology and radiology in Latin America and the Caribbean (OPRIPALC)

El objetivo del presente artículo ha sido describir el programa "Optimización de la Protección en Radiología Intervencionista Pediátrica en América Latina y el Caribe" (OPRIPALC) que nace el año 2018 como respuesta conjunta de la Organización Panamericana de la Salud y la Organización Mundial de la Salud, en cooperación con el Organismo Internacional de Energía Atómica, para colaborar con sus Estados miembros en asegurar que las exposiciones a la radiación de los pacientes pediátricos sean las mínimas necesarias durante los procedimientos intervencionistas. Actualmente, hay 18 centros de los siguientes 10 países que participan: Argentina, Brasil, Chile, Colombia, Costa Rica, Cuba, Ecuador, México, Perú y Uruguay. Para el desarrollo del programa se plantean una serie de objetivos, productos, actividades y resultados esperados. La puesta en marcha de la WEB de OPRIPALC ha significado un instrumento muy válido para seguir la información actualizada del programa. Un programa actualizado de formación en radioprotección para los profesionales implicados en el programa, se está realizando por medio de "webinars". Se deberá seguir actuando en la aplicación del programa de control de calidad básico para los equipos de rayos X participantes y validar los valores de los Niveles de Referencia para Diagnóstico (NRDs). Se propone formar un equipo de trabajo entre los Físicos Médicos y Tecnólogos Médicos participantes de OPRIPALC para implicarse en las pruebas de control básicas que todos los centros debieran realizar. Se han presentado algunos resultados iniciales de OPRIPALC en eventos científicos internacionales. Se está avanzando en proponer unos primeros valores sobre NRDs en procedimientos de intervencionismo cardiológico pediátrico por bandas de edad y peso. OPRIPALC es una de las pocas iniciativas de carácter regional para obtener valores de NRDs en procedimientos intervencionistas pediátricos. Se espera que tanto los valores de referencia como la metodología empleada en OPRIPALC, puedan ser utilizados en otras regiones del mundo.

The objective of this article has been to describe the program "Optimization of Protection in Pediatric Interventional Radiology in Latin America and the Caribbean" (OPRIPALC) that was born in 2018 as a joint response of the Pan American Health Organization and the World Organization of the Health, in cooperation with the International Atomic Energy Agency, to collaborate with its member states in ensuring that radiation exposures of pediatric patients are the minimum necessary during interventional procedures. Currently, there are 18 centers from the following 10 countries participating: Argentina, Brazil, Chile, Colombia, Costa Rica, Cuba, Ecuador, Mexico, Peru and Uruguay. For the development of the program, a series of objectives, products, activities and expected results are proposed. The launch of the OPRIPALC WEBSITE has been a very valid instrument for following up-to-date information on the program. An updated training program in radiation protection for the professionals involved in the program is being carried out through webinars. It should continue acting in the application of the basic quality control program for the participating X-ray equipment and validate the values of the Diagnostic Reference Levels (DRLs). It is proposed to form a work team among the OPRIPALC participating medical physicists to get involved in the basic control tests that all centers should carry out. Some initial results of OPRIPALC have been presented at international scientific events. Progress is being made in proposing first values on DRLs in pediatric cardiac intervention procedures by age and weight bands. OPRIPALC is one of the few regional initiatives to obtain DRLs values in pediatric interventional procedures. It is expected that both the reference values and the methodology used in OPRIPALC can be used in other regions of the world.

Drying-Time Study in Graphene Oxide.

Graphene oxide (GO) exhibits different properties from those found in free-standing graphene, which mainly depend on the type of defects induced by the preparation method and post-processing. Although defects in graphene oxide are widely studied, we report the effect of drying time in GO and how this modifies the presence or absence of edge-, basal-, and sp3-type defects. The effect of drying time is evaluated by Raman spectroscopy, UV-visible spectroscopy, and transmission electron microscopy (TEM). The traditional D, G, and 2D peaks are observed together with other less intense peaks called the D', D*, D**, D+G, and G+D. Remarkably, the D* peak is activated/deactivated as a direct consequence of drying time. Furthermore, the broad region of the 2D peak is discussed as a function of its deconvoluted 2D1A, 2D2A, and D+G bands. The main peak in UV-visible absorption spectra undergoes a redshift as drying time increases. Finally, TEM measurements demonstrate the stacking of exfoliated GO sheets as the intercalated (water) molecules are removed.

The Adsorption of Methylene Blue on Eco-Friendly Reduced Graphene Oxide.

Recently, green-prepared oxidized graphenes have attracted huge interest in water purification and wastewater treatment. Herein, reduced graphene oxide (rGO) was prepared by a scalable and eco-friendly method, and its potential use for the removal of methylene blue (MB) from water systems, was explored. The present work includes the green protocol to produce rGO and respective spectroscopical and morphological characterizations, as well as several kinetics, isotherms, and thermodynamic analyses to successfully demonstrate the adsorption of MB. The pseudo-second-order model was appropriated to describe the adsorption kinetics of MB onto rGO, suggesting an equilibrium time of 30 min. Otherwise, the Langmuir model was more suitable to describe the adsorption isotherms, indicating a maximum adsorption capacity of 121.95 mg g-1 at 298 K. In addition, kinetics and thermodynamic analyses demonstrated that the adsorption of MB onto rGO can be treated as a mixed physisorption-chemisorption process described by H-bonding, electrostatic, and π - π interactions. These results show the potential of green-prepared rGO to remove cationic dyes from wastewater systems.

Finding a common core microbiota in two Brazilian dairies through culture and DNA metabarcoding studies.

Dairy foods are complex ecosystems composed of microorganisms from different origins that can affect flavor and safety of final products. The objective of this paper is to assess the in-house microbiota of two Brazilian dairies and to discuss the possible implications of the taxa determined for food protection. In total, 27 samples from dairies were cultured in selective (Baird Parker, de Man, Rogosa and Sharpe) and non-selective (Brain Heart Infusion) media, and the isolates were identified by Sanger sequencing. Moreover, metagenomic DNA was directly extracted from samples and the structure of the bacterial community was determined by massive DNA sequencing followed by bioinformatics analyses. The results showed the majority of isolates belonged to the group of lactic acid bacteria, but Enterobacteriaceae, Staphylococcacceae, Bacillaceae, Pseudomonadaceae and Moraxellaceae were also detected. From the reads obtained in metataxonomics analyses, a heatmap was constructed and the top 20 OTUs (operational taxonomic units) were determined. Besides, 12 most prevalent bacterial taxa were assigned to the core microbiota of the dairies evaluated, which included Thiomonas thermosulfata, Alkalibacillus salilacus, Pseudomonas clemancea, Erythrobacter aquimans, Tetragenococcus doogicus, Macrococcus brunensis, Pseudomonas ludensis, Streptococcus dentinousetti, Serratia entomophila, Vagococcus teuberi, Lactococcus fujiensis and Tolumonas auensis. In conclusion, the results reveal the presence of bacteria that may be related to spoilage and also foodborne diseases, in microbial niches that also present rare taxa, highlighting the importance to consider culture-independent results to evaluate and improve food safety.

Biogenetic study of the emissions of species: Pinus radiata, Eucalyptus globulus Labill and Alnus acuminata in Riobamba canton, Ecuador.

Background: Air pollution is one of the biggest problems in the world, and it is generated by industrial production, vehicular flow and use of fossil fuels, leaving aside other important emission sources such as vegetation. The aim of this research is to quantify the emissions of natural volatile organic compounds produced by the forest species: Eucalyptus globulus L., Pinus radiata and Alnus acuminata in Riobamba, Ecuador. Methods: Identification of plant coverings in the years 2014 and 2017was performed using geographic information systems tools, complemented with the application of the Guenther model for the calculation of monoterpenes and other organic volatile compounds; thus, to analyze the relationship between meteorological variables and concentrations of volatile organic compounds and nitrogen dioxide per species. Results: Mathematical calculation of emissions in Riobamba showed that Eucalyptus globulus L. registered higher emissions in the years 2014-2017, followed by Pinus radiata and Alnus acuminata. These emissions are due to the vegetation cover covering each species. The analysis of volatile organic compounds in forest plantations in air is directly related to the emissions represented in the environment and correlated with the meteorological variables of temperature, global solar radiation and wind velocity. The proposed method manages to estimate concentrations of monoterpenes and volatile organic compounds for the two examined seasons, presenting the influence of the species introduced in this study such as Eucalyptus globulus L. and Pinus radiata, with a reduction in their emissions (less area found in the year 2017, with respect to 2014). However, the emission of Alnus acuminata can be quantified only in 2017, since in 2014 no records of this species were found. Conclusions: Volatile organic compound concentrations in the air are directly related to the emissions represented spatially and correlated with the meteorological variables of temperature, global solar radiation and wind velocity.

Persistencia del conducto onfalomesentérico

La persistencia del conducto onfalomesentérico y del uraco constituyen las malformaciones congénitas más frecuentes de la región umbilical. Un fracaso en la regresión del conducto onfalomesentérico determina el origen de un amplio espectro de anomalías relacionadas con la pared abdominal, entre ellas la persistencia del conducto onfalomesentérico. Se presenta el caso de un paciente de 10 años de edad con persistencia completa y permeable del conducto onfalomesentérico; lo inusual fue su presentación con un cuadro de abdomen agudo, motivo por el cual se diagnosticó inicialmente como apendicitis aguda. Se recalca la importancia de este tipo de casos por sus múltiples manifestaciones clínicas y las complicaciones que conlleva.

The persistence of the omphalomesenteric duct and the urachus are the most frequent congenital malformations of the umbilical region. A failure in the regression of the omphalomesenteric duct determines the origin of a wide spectrum of abnormalities related to the abdominal wall, including the persistence of the omphalomesenteric duct. We present the case of a 10-year-old patient with complete and permeable persistence of the omphalomesenteric duct, what makes the case unusual is its presentation with acute abdomen, reason for which it was initially diagnosed as acute appendicitis. The importance of this type of case is emphasized by its multiple clinical manifestations and the complications that it entails

Study of the adsorption of mercury (II) on lignocellulosic materials under static and dynamic conditions.

WHO has declared mercury as one of the most dangerous pollutants for human health. Unfortunately, several cases of rivers and aquifers contaminated by mercury inevitably poses the problem on how to remediate them. Considerable efforts are being addressed to develop cost-effective methodologies, among which the use of low-cost adsorbing materials. In this paper, the adsorption performances of an alternative lignocellulosic material derived from the Spanish broom plant, are presented. This plant is widely diffused in the world and its usage for Hg(II) removal from water in real working conditions requires only minimal pretreatment steps. A thoroughly investigation on the kinetics and thermodynamics of Hg(II) adsorption on Spanish broom is presented, by using Hg(II) polluted aqueous solutions specifically prepared in order to simulate typical groundwater conditions. Several batch experiments, under static conditions, were carried out in order to evaluate the effect of pH, contact time, adsorbent dosage, initial concentration, temperature. A maximum adsorption capacity of 20 mg L-1 can be obtained at pH 5, following a pseudo second order kinetics. Moreover, adsorption experiments in dynamic conditions were carried out using Spanish broom filters. Interestingly, a systematic, unconventional double S-shape breakthrough curve was observed under different experimental conditions, revealing the occurrence of two adsorption processes with different time scales. This behavior has been fitted by a bimodal Thomas model which, unlike the single Thomas fitting, gives satisfactory results with the introduction of a new parameter related to the fraction of surface active sites involved in the adsorption processes.

Optimizing a culture medium for biomass and phenolic compounds production using Ganoderma lucidum.

The present work was aimed at optimizing a culture medium for biomass production and phenolic compounds by using Ganoderma lucidum. The culture was optimized in two stages; a Plackett-Burman design was used in the first one for identifying key components in the medium and a central composite design was used in the second one for optimizing their concentration. Both responses (biomass and phenolic compounds) were simultaneously optimized by the latter methodology regarding desirability, and the optimal concentrations obtained were 50.00 g/L sucrose, 13.29 g/L yeast extract and 2.99 g/L olive oil. Maximum biomass production identified in these optimal conditions was 9.5 g/L and that for phenolic compounds was 0.0452 g/L, this being 100% better than that obtained in the media usually used in the laboratory. Similar patterns regarding chemical characterization and biological activity towards Aspergillus sp., from both fruiting body and mycelium-derived secondary metabolites and extracts obtained in the proposed medium were observed. It was shown that such statistical methodologies are useful for optimizing fermentation and, in the specific case of G. lucidum, optimizing processes for its production and its metabolites in submerged culture as an alternative to traditional culture.

Análisis del manejo quirúrgico de la enfermedad de Hirschsprung en el Hospital Nacional de Niños Dr. Carlos Sáenz Herrera, durante el periodo 2000-2010 / Surgical treatment of Hirschsprung's disease at the National Children's Hospital

Antecedentes: la enfermedad de Hirschsprung es causa de obstrucción intestinal baja en neonatos. Se caracteriza por ausencia de inervación en un segmento intestinal. El tratamiento radica en la resección de ese segmento intestinal enfermo para permitir el funcionamiento correcto del intestino sano. Se analizó el manejo de esta patología en el Hospital Nacional de Niños Dr. Carlos Sáenz Herrera, durante el periodo 2000-2010 y su epidemiología. Métodos: se realizó un estudio observacional retrospectivo; se revisó 130 expedientes usando Microsoft Excel y el programa estadístico JMP. Resultados: se identificó una relación de hombre: mujer de 4:1, la mayoría de los casos se presentó en recién nacidos de término. Los síntomas iniciales más frecuentes fueron distensión abdominal y vómitos biliosos. La edad de presentación, en el 78 por ciento de los casos, fue de menos de 1 mes. Dentro de las cirugías realizadas se evidenció que en el 35 por ciento de los casos se utilizó la técnica del descenso endorrectaltransanal y en el 48 por ciento, la técnica de Duhamel. Entre las complicaciones postoperatorias en el grupo de descenso endorrectaltransanal, la más frecuente fue la enterocolitis, en 14 de 19 casos, mientras que la complicación más frecuente en el grupo de Duhamel, fue el tabique rectal, en 8 de 21 casos. Conclusión: las características clínicas y epiedemiológicas de los casos de enfermedad de Hirschsprung analizados, son similares a las descritas en la bibliografía. Las complicaciones postoperatorias y la morbilidad fue similar para ambas técnicas quirúrgicas...

Optimizing a culture medium for biomass and phenolic compounds production using Ganoderma lucidum

The present work was aimed at optimizing a culture medium for biomass production and phenolic compounds by using Ganoderma lucidum. The culture was optimized in two stages; a Plackett-Burman design was used in the first one for identifying key components in the medium and a central composite design was used in the second one for optimizing their concentration. Both responses (biomass and phenolic compounds) were simultaneously optimized by the latter methodology regarding desirability, and the optimal concentrations obtained were 50.00 g/L sucrose, 13.29 g/L yeast extract and 2.99 g/L olive oil. Maximum biomass production identified in these optimal conditions was 9.5 g/L and that for phenolic compounds was 0.0452 g/L, this being 100% better than that obtained in the media usually used in the laboratory. Similar patterns regarding chemical characterization and biological activity towards Aspergillus sp., from both fruiting body and mycelium-derived secondary metabolites and extracts obtained in the proposed medium were observed. It was shown that such statistical methodologies are useful for optimizing fermentation and, in the specific case of G. lucidum, optimizing processes for its production and its metabolites in submerged culture as an alternative to traditional culture.

Caracterización de una población pediátrica con invaginación intestinal diagnósticada en un hospital de referencia durante un periodo de 8 años / Description of a group of children with intestinal intussusception diagnosed in a reference hospital during a period of 8 years

Objetivo: El objetivo general del estudio fue describir todos los casos documentados de invaginación intestinal en niños menores de 24 meses en el HNN durante el periodo 2001-2008. Métodos: estudio retrospectivo y descriptivo, basado en la información de expedientes clínicos y del Servicio de Estadística, de todos los egresos hospitalarios con el diagnóstico de invaginación intestinal en niños menores de 24 meses durante el periodo: enero 2001 a diciembre 2008. Resultados: durante este periodo de estudio la media de la tasa de incidencia de invaginación intestinal en el HNNH fue de 31 por cada 100000 nacidos vivos. La distribución de pacientes por sexo y grupo de edad fue: 57.7 por ciento hombres y 42.3 por ciento mujeres, p:0.003. El 85.2 por ciento de los episodios de invaginación intestinal ocurrió en niños menores de 12 meses, 14.8 por ciento de 12 a 24 meses, 27/182 pacientes. La edad media de presentación fue de 7.7 meses. 103 pacientes requirieron ser llevados a sala de operaciones para desinvaginación por taxis, de los cuales el 79.61 por ciento, 82, tuvieron un colon por enema fallido. La perforación intestinal fue la complicación más frecuente en un 12.6 por ciento de los casos, 13. Se realizó resección intestinal en 16 casos, 15.50 por ciento. Conclusiones: este estudio brinda información sobre la epidemiología de la invaginación intestinal en Costa Rica siendo éste un estudio base para futuras investigaciones asociadas a la introducción de las vacunas del rotavirus en el esquema de vacunación del país.