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Singlet dioxygen has been widely applied in different disciplines such as medicine (photodynamic therapy or blood sterilization), remediation (wastewater treatment) or industrial processes (fine chemicals synthesis). Particularly, it can be conveniently generated by energy transfer between a photosensitizer's triplet state and triplet dioxygen upon irradiation with visible light. Among the best photosensitizers, substituted zinc(II) phthalocyanines are prominent due to their excellent photophysical properties, which can be tuned by structural modifications, such as halogen- and chalcogen-atom substitution. These patterns allow for the enhancement of spin-orbit coupling, commonly attributed to the heavy atom effect, which correlates with the atomic number ( Z ${Z}$ ) and the spin-orbit coupling constant ( ζ ${\zeta }$ ) of the introduced heteroatom. Herein, a fully systematic analysis of the effect exerted by chalcogen atoms on the photophysical characteristics (absorption and fluorescence properties, lifetimes and singlet dioxygen photogeneration), involving 30 custom-made ß-tetrasubstituted chalcogen-bearing zinc(II) phthalocyanines is described and evaluated regarding the heavy atom effect. Besides, the intersystem crossing rate constants are estimated by several independent methods and a quantitative profile of the heavy atom is provided by using linear correlations between relative intersystem crossing rates and relative atomic numbers. Good linear trends for both intersystem crossing rates (S1-T1 and T1-S0) were obtained, with a dependency on the atomic number and the spin-orbit coupling constant scaling as Z 0 . 4 ${{Z}^{0.4}}$ and ζ 0 . 2 ${{\zeta }^{0.2}}$ , respectively The trend shows to be independent of the solvent and temperature.

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The rechargeable lithium air (oxygen) battery (Li-O2) has very high energy density, comparable to that of fossil fuels (∼3600 W h kg-1). However, the parasitic reactions of the O2 reduction products with solvent and electrolyte lead to capacity fading and poor cyclability. During the oxygen reduction reaction (ORR) in aprotic solvents, the superoxide radical anion (O2˙-) is the main one-electron reaction product, which in the presence of Li+ ions undergoes disproportionation to yield Li2O2 and O2, a fraction of which results in singlet oxygen (1O2). The very reactive 1O2 is responsible for the spurious reactions that lead to high charging overpotential and short cycle life due to solvent and electrolyte degradation. Several techniques have been used for the detection and suppression of 1O2 inside a Li-O2 battery under operation and to test the efficiency and electrochemical stability of different physical quenchers of 1O2: azide anions, 1,4-diazabicyclo[2.2.2]octane (DABCO) and triphenylamine (TPA) in different solvents (dimethyl sulfoxide (DMSO), diglyme and tetraglyme). Operando detection of 1O2 inside the battery was accomplished by following dimethylanthracene fluorescence quenching using a bifurcated optical fiber in front-face mode through a quartz window in the battery. Differential oxygen-pressure measurements during charge-discharge cycles vs. charge during battery operation showed that the number of electrons per oxygen molecule was n > 2 in the absence of physical quenchers of 1O2, due to spurious reactions, and n = 2 in the presence of physical quenchers of 1O2, proving the suppression of spurious reactions. Battery cycling at a limited specific capacity of 500 mA h gC-1 for the MWCNT cathode and 250 mA gC-1 current density, in the absence and presence of a physical quencher or a physical quencher plus the redox mediator I3-/I- (with a lithiated Nafion® membrane), showed increasing cyclability according to coulombic efficiency and cell voltage data over 100 cycles. Operando Raman studies with a quartz window at the bottom of the battery allowed detection of Li2O2 and excess I3- redox mediator during discharge and charge, respectively.

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BACKGROUND: Acute-on-chronic liver failure (ACLF) is a severe clinical entity associated with elevated short-term mortality. We aimed to characterize patients with decompensated cirrhosis according to presence of ACLF, their association with active alcohol intake, and long-term survival in Latin America. METHODS: Retrospective cohort study of decompensated cirrhotic in three Chilean university centers (2017-2019). ACLF was diagnosed according EASL-CLIF criteria. We assessed survival using competing-risk and time-to-event analyses. We evaluated the time to death using accelerated failure time (AFT) models. RESULTS: We included 320 patients, median age of 65.3±11.7 years old, and 48.4% were women. 92 (28.7%) patients met ACLF criteria (ACLF-1: 29.3%, ACLF-2: 27.1%, and ACLF-3: 43.4%). The most common precipitants were infections (39.1%), and the leading organ failure was kidney (59.8%). Active alcohol consumption was frequent (27.7%), even in patients with a prior diagnosis of non-alcoholic fatty liver disease (NAFLD) (16.2%). Ninety-two (28.7%) patients had ACLF (ACLF-1: 8.4%, ACLF-2: 7.8%, and ACLF-3: 12.5%). ACLF patients had a higher MELD-Na score at admission (27 [22-31] versus 16 [12-21], p<0.0001), a higher frequency of alcohol-associated liver disease (36.7% versus 24.9%, p=0.039), and a more frequent active alcohol intake (37.2% versus 23.8%, p=0.019). In a multivariate model, ACLF was associated with higher mortality (subdistribution hazard ratio 1.735, 95%CI: 1.153-2.609; p<0.008). In the AFT models, the presence of ACLF during hospitalization correlated with a shorter time to death: ACLF-1 shortens the time to death by 4.7 times (time ratio [TR] 0.214, 95%CI: 0.075-0.615; p<0.004), ACLF-2 by 4.4 times (TR 0.224, 95%CI: 0.070-0.713; p<0.011), and ACLF-3 by 37 times (TR 0.027, 95%CI: 0.006-0.129; p<0.001). CONCLUSIONS: Patients with decompensated cirrhosis and ACLF exhibited a high frequency ofactive alcohol consumption. Patients with ACLF showed higher mortality and shorter time todeath than those without ACLF.

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Las vacunas previenen millones de muertes cada año y su eficacia y seguridad han sido ampliamente establecidas. En términos económicos, la vacunación es una de las intervenciones sanitarias más costo efectivas, generando un importante ahorro y crecimiento económico que supone a largo plazo. Se ha demostrado que la vacunación de adultos disminuye la morbilidad y la mortalidad asociadas a enfermedades infecciosas prevenibles, reduciendo las complicaciones y las hospitalizaciones, incluidos los ingresos a las unidades de cuidados intensivos. Hemos elaborado este documento de consenso con el objeto de diseñar un esquema de vacunación pragmático, accesible y estandarizado del adulto, según categoría de riesgo y edad, sobre la base de la evidencia disponible de vacunas accesibles y nuevas vacunas habiendo utilizado el Tercer Consenso de la Sociedad Paraguaya de Infectología del 2019 como base para las recomendaciones finales.

SUMMARY Vaccines prevent millions of deaths each year, and their efficacy and safety have been widely established. In economic terms, vaccination is one of the most cost-effective health interventions, generating significant savings and long-term economic growth. Adult vaccination has been shown to decrease morbidity and mortality associated with preventable Infectious diseases, reducing complications and hospitalizations, including admissions to intensive care units. We have prepared this consensus document in order to design a pragmatic, accessible and standardized vaccination scheme for adults, according to risk category and age, based on the available evidence of available vaccines and new vaccines, having used the third consensus of the Paraguayan Infectious Diseases Society of 2019 as a basis for the final recommendations.

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We present a reverse microemulsion synthesis procedure for incorporating methylene blue (MB), a known FDA-approved type-II red-absorbing photosensitizer and 1O2 generator, into the matrix of hydrophobic-core/hydrophilic-shell SiO2 nanoparticles. Different synthesis conditions were explored with the aim of controlling the entrapped-dye aggregation at high dye loadings in the hydrophobic protective core; minimizing dye aggregation ensured highly efficient photoactive nanoentities for 1O2 production. Monitoring the synthesis in real time using UV-vis absorption allowed tracking of the dye aggregation process. In particular, silica nanoparticles (MB@SiO2 NPs) of ∼50 nm diameter size with a high local entrapped-MB concentration (∼10-2 M, 1000 MB molecules per NP) and a moderate proportion of dye aggregation were obtained. The as-prepared MB@SiO2 NPs showed a high singlet oxygen photogeneration efficiency (ΦΔ = 0.30 ± 0.05), and they can be also considered as red fluorescent probes (ΦF ∼ 0.02, λmax ∼ 650 nm). The distinctive photophysical and photochemical characteristics of the synthesized NPs reveal that the reverse microemulsion synthesis procedure offers an interesting strategy for the development of complex theranostic nano-objects for photodynamic therapy.

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RESUMEN INTRODUCCION: El ataque cerebrovascular (ACV) de etiología isquémica es una patología cuya incidencia y mortalidad aumentaron en la última década. Cuando se maneja oportunamente, mediante trombólisis como terapia inicial, mejora su desenlace y funcionalidad. En el departamento del Tolima (Colombia) no hay registros de esta patología y en el país la bibliografía al respecto es limitada. El objetivo de este estudio es evaluar los desenlaces clínicos del manejo agudo con r-tPA en los pacientes que presentaron ACV isquémico en dos instituciones de la ciudad de Ibagué, capital de dicho departamento, entre junio del 2019 y junio del 2020, e identificar los tiempos de atención hospitalaria y las principales variables asociadas con el grupo de pacientes que fallecieron. MATERIALES Y METODOS: Estudio descriptivo de corte transversal del manejo del ACV isquémico con r-tPA, en el que se describen las variables sociodemográficas, la escala NIHSS como evaluación neurológica inicial, los tiempos de atención (inicio-aguja, puerta-tac y puerta-aguja), los desenlaces postoperatorios y el Rankin modificado al egreso. RESULTADOS: Se incluyeron 38 pacientes con una media de 67,37 años, el 60,53 % fueron mujeres. La escala NIHSS al ingreso fue 13,47 puntos (DE 5,24). Los tiempos de atención fueron 183 minutos (DE 72,63) inicio-aguja, 41 minutos (RIQ 17-72) puerta-TAC y 101,50 minutos (RIQ 77 - 137,25) puerta-aguja. La mortalidad fue del 23,68 %. CONCLUSION: La mortalidad y el desenlace funcional del ACV en nuestra población fueron similares a los reportados en la literatura nacional e internacional, sin embargo, es preciso implementar protocolos de atención del infarto cerebral para incrementar el número de pacientes con desenlace favorable, acortando los tiempos de atención en toda la cadena del tratamiento adecuado del infarto cerebral.

ABSTRACT INTRODUCTION: Ischemic stroke is a growing disease in the last decade, increasing both its incidence and its mortality. However, timely thrombolysis management as initial therapy can improve both disease progression as well as an individual's functionality. In Tolima, there are no registries of this disease and in Colombia in general, the literature is limited. The objective of this study is to investigate the clinical outcomes of the acute management of ischemic stroke using r-tPA as well as identifying in-hospital treatment times, at two institutions in Ibague between 2019 and 2020. METHODS AND MATERIALS: Using a cross-sectional descriptive study, we describe the management of ischemic stroke using r-tPA, describing sociodemographic variables, NIHSS scale as the initial neurological evaluation, in-hospital treatment times (symptoms-to-needle, door-to-TAC, door-to-needle), the clinical outcomes, and lastly the modified Rankin score upon discharge. RESULTS: We included 38 patients with median age of 67,37 years, 60,53 % were females. The initial average NIHSS scale upon admission was 13,47 (DE 5,24). In-hospital attention time averages were: symptoms-to-needle 183 minutes (DE 72,63), door-to-CAT 41 minutes (RIQ 17-72), and door-to-needle 101,50 minutes (RIQ 77-137,25). Overall the rate of mortality was 23,68 %. CONCLUSIONS: Mortality and functionality outcomes of the stroke population observed was similar to previously reported, both nationally and internationally. However, protocols should be implemented for the timely ischemic stroke management to improve the number of patients with favorable outcomes, by reducing the in-hospital attention times in all areas of the management chain.

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RESUMEN INTRODUCCIÓN: La ganglionopatía sensitiva es una rara complicación del déficit de vitamina B12, la cual da origen a un espectro de síntomas neurológicos que incluyen alteración de la sensibilidad vibratoria, propiocepción, ataxia y, con menor frecuencia, trastornos del movimiento. La pseudoatetosis es una presentación muy inusual. CASO CLÍNICO: Un paciente masculino de 73 años se presenta con parestesias y torpeza de las cuatro extremidades, dolor tipo urente en plantas de pies y manos, inestabilidad postural y limitación para la marcha. En la exploración neurológica se encuentra hipoestesia y ataxia sensitiva de las cuatro extremidades, con presencia de pseudoatetosis de los miembros superiores como consecuencia de ganglionopatía por déficit de vitamina B12 demostrada por la imagen típica de "V" invertida, debido a compromiso de las proyecciones centrales las neuronas sensitivas mielinizadas en RMN de columna cervicotoráccica. A los cuatro meses se reporta mejoría del déficit propioceptivo y corrección del trastorno de movimiento gracias a la reposición de la cianocobalamina intramuscular. Hasta el momento no se presenta patología neoplásica, autoinmune o infecciosa. CONCLUSIONES: La ganglionopatía sensitiva por déficit de vitamina B12 es una condición potencialmente reversible y subdiagnosticada que puede manifestarse ocasionalmente con trastornos del movimiento. Debe sospecharse en pacientes con déficits sensitivos por compromiso de fibra gruesa. Su pronóstico es favorable si la causa del déficit se documenta tempranamente y se hace reposición de dicha vitamina.

SUMMARY INTRODUCTION: Sensory ganglionopathy is a rare complication of vitamin B12 deficiency, causing an spectrum of neurologic symptoms such as abnormal vibratory sensitivity, proprioception, gait disturbance and rarely movement disorders like pseudoatetosis and dystonia. CLINICAL CASE: A73-year-old man was admitted with numbness and clumsiness of his extremities, burning pain on palms and soles, postural instability and impaired walking. Neurological examination demonstrated hypesthesia and sensory ataxia of four limbs with associated pseudo athetoid movements of the upper limbs as a consequence of ganglionopathy by vitamin B12 deficiency, showing typical MRI inverted "V" sign due to degeneration of central projections from large sensory neurons, which was successfully treated with IM cyanocobalamin 4 months later. CONCLUSIONS: Sensory ganglionopathy in B12 deficit is a potentially reversible and underdiagnosed condition, which occasionally can present with movement disorders. Must be suspected in patiens presenting with sensory deficits depending on richly myelinated axons. Usually with good prognosis after identifying the deficit's cause and giving propper treatment.

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RESUMEN Introducción: A partir de la pandemia por la COVID-19, declarada por la Organización Mundial de la Salud, el contexto educativo se enfrenta a una de las mayores crisis, evidenciado por carencias y desigualdades, como lo es la disponibilidad de recursos en la preparación de docentes y alumnos al momento de incorporarse a modalidades de educación a distancia. Objetivo: Identificar los principales retos y desafíos de los docentes de Educación Básica de Nuevo León en el periodo de marzo a junio de 2020, durante dicha pandemia. Método: Se realizó una investigación cuantitativa de corte exploratoria descriptiva, se tomó una muestra de 548 profesores, seleccionados por muestreo no probabilístico voluntario, se aplicó un cuestionario para encuesta; se utilizaron pruebas de fiabilidad y paquetes estadísticos Minitab 19 y SPSS 21, para la fase de análisis. Resultados: Los desafíos identificados desde la perspectiva del docente se categorizaron en función de su propio rol, con base en lo que vislumbraron en sus estudiantes, y van desde problemas socio afectivo, tecnológico, de comunicación, pedagógicos y académicos. Conclusiones: Se evidencian problemáticas altamente variadas, desde la perspectiva docente relacionadas con su propio proceder, hasta el desenvolvimiento de sus estudiantes; se identificaron las fortalezas y áreas de oportunidad que aquejan al sistema educativo mexicano, y la necesidad de asumir el compromiso de una educación en, por y para los medios, resaltando la importancia de educar en la era digital.

ABSTRACT Introduction: Since the World Health Organization (WHO) declared the coronavirus a pandemic, the educative context is facing one of the greatest crises, associated with shortages and inequalities, and lack of resources, at the time of incorporating distance learning modalities by teachers and students. Objective: To identify the main challenges and defiance faced by the teachers in the basic education in Nuevo León, Mexico, from March to June 2020. Method: A descriptive exploratory quantitative research was carried out. As sample, 548 teachers were involved in the study, selected by voluntary non-probabilistic sampling. A survey questionnaire was applied and reliability tests and Minitab 19 and SPSS 21 statistical packages were used for the phase of analysis. Results: From the teacher´s perspective, the challenges found were categorized according to their own role, based on the factors observed on their students, such as, the socio-affective, technological, communicative, pedagogical and academic problems. Conclusions: Problems found were highly diverse, ranging from the teacher's behavior to the student´s performance. The strengths and areas of opportunities that afflict the Mexican education system were identified, as well as the need to assume the commitment of education in, by and for the media, highlighting the importance of teaching in the digital age.

RESUMO Introdução: Desde a pandemia do coronavírus, declarada pela Organização Mundial da Saúde (OMS), o contexto educacional enfrenta uma das maiores crises, evidenciada por deficiências e desigualdades, tanto na disponibilidade de recursos, quanto na preparação de professores e alunos à época de ingressar nas modalidades de educação a distância. Objetivo: Identificar os principais desafios e desafios identificados pelos professores da Educação Básica de Nuevo León, México, no período de março a junho de 2020. Método: Foi realizada uma pesquisa exploratória descritiva quantitativa, com amostra de 548 professores, selecionados por voluntários amostragem não probabilística, aplicou-se questionário survey; Testes de confiabilidade e pacotes estatísticos Minitab 19 e SPSS 21 foram usados ​​para a fase de análise. Resultados: Os desafios identificados na perspectiva do professor foram categorizados de acordo com seu próprio papel, a partir do que vislumbraram em seus alunos, e vão desde problemas socioafetivos, tecnológicos, de comunicação, pedagógicos e acadêmicos. Conclusões: Evidenciam-se problemas muito variados, desde a perspectiva de ensino relacionada ao próprio comportamento, até o desenvolvimento de seus alunos; Foram identificados os pontos fortes e as oportunidades que afligem o sistema educacional mexicano, bem como a necessidade de assumir o compromisso de uma educação na, pela e para a mídia, destacando a importância de educar na era digital.

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INTRODUCTION AND AIMS: Several non-invasive scoring systems have been developed and validated worldwide to predict the risk of liver fibrosis in nonalcoholic fatty liver disease (NAFLD). However, information about the performance of these systems in Latin American populations is scarce. Our aim was to evaluate the performance of the Hepamet Fibrosis Score, Fibrosis-4 (FIB-4) and the NAFLD Fibrosis Score (NFS) in a mixed Latin American group of NAFLD patients. METHODS: Clinical, laboratory and liver biopsy data collected from 379 biopsy-proven NAFLD patients from Latin American tertiary health centers were reviewed. Histological fibrosis stages were classified using the Kleiner score. Accuracy was determined, and new fibrosis score thresholds were calculated to better compare the performances of non-invasive tests and to explore their usefulness in excluding fibrosis. RESULTS: The distribution of fibrosis stages among the sample population was as follows: F0 (45%), F1 (27%), F2 (8%), F3 (16%) and F4 (4%). Using modified thresholds, the areas under the ROC curves (AUROC) for Hepamet and FIB-4 (0.73 and 0.74, respectively) to detect significant fibrosis were higher than that of NFS (0.58). However, the AUROCs of the three scores were not significantly different in advanced fibrosis and cirrhosis. To exclude fibrosis, we calculated lower cutoffs than standard thresholds for Hepamet, FIB-4 and NFS with similar performances. CONCLUSION: Thresholds of non-invasive fibrosis scores (Hepamet, FIB-4 and NFS) can be modified to maximize diagnostic accuracy in Latin American patients with NAFLD.

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RESUMEN INTRODUCCIÓN. El tiempo es un factor importante en el tratamiento del ACV agudo, con la pandemia de covid-19 se puede ver afectada la adherencia a las guías. Se han reportado tasas de ACV en presencia de covid-19 alrededor del 5%, además un aumento en el tiempo de consulta de los pacientes en otras regiones del mundo y una mayor ocupación de camas de UCI para patologías respiratorias que usualmente se destinan a pacientes con ACV. Este documento recoge las recomendaciones del comité de Enfermedad Cerebrovascular de la Asociación Colombiana de Neurología basados en la literatura y votadas por consenso. OBJETIVOS. Proporcionar una guía rápida adaptada a los diferentes escenarios de atención de ACV en Colombia, divididos en centro listo, primario y avanzado incluyendo una ruta de atención para paciente con sospecha de covid-19 denominada Código ACV protegido, que incluye el uso de elementos de protección personal para pacientes y personal de salud. PUNTOS PRINCIPALES. Dentro de las recomendaciones principales está el cuestionario de tamizaje al ingreso a urgencias, uso de tapabocas para el paciente, considerar todo Código ACV sospechoso de covid-19, toma de PCR para covid-19 en todos los ACV y llevar a zona buffer. En sospecha de oclusión proximal incluir tomo-grafía de tórax a la evaluación de imágenes. CONCLUSIONES. Establecer pautas de atención durante la pandemia covid-19 permite optimizar protección para pacientes y personal de salud, disminuir retrasos y tratar de evitar que pacientes no reciban el tratamiento adecuado en los diferentes niveles de atención del sistema de salud.

SUMMARY INTRODUCTION. Time is an important factor in the treatment of acute stroke, with the COVID-19 pandemic adherence to guidelines can be affected. Stroke rates in the presence of COVID-19 have been reported around 5%, in addition to an increase in the consultation time of patients in other regions of the world and a greater occupation of ICU beds for respiratory pathologies that are usually intended for patients with stroke. This document contains the recommendations of the Cerebrovascular Disease Committee of the Colombian Neurology Association based on the literature and voted by consensus. OBJECTIVES. Provide a quick guide adapted to the different stroke care scenarios in Colombia, divided into ready, primary and advanced centers, including a care route for a patient with suspected COVID-19 called the protected stroke code, which includes the use of protection elements for the patient and the healthcare team. MAIN FACTS. Among the main recommendations are the screening questionnaire on admission to the emergency department, the use of face masks for the patient, considering all suspected stroke code as COVID-19, taking the PCR for COVID-19 in all strokes and taking them to the buffer zone. In suspected large vessel occlusion, include chest tomography to image evaluation. CONCLUSIONS. Establishing guidelines of care during the COVID-19 pandemic allows optimizing protection for patients and health care personnel, reducing delays and trying to avoid patients not receiving adequate treatment at different levels of attention in the health system.

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