A Case-Study on the Photophysics of Chalcogen-Substituted Zinc(II) Phthalocyanines.

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.

Operando detection and suppression of spurious singlet oxygen in Li-O2 batteries.

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.

Active alcohol consumption is associated with acute-on-chronic liver failure in Hispanic patients.

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.

Primer Consenso Nacional Intersociedades de Inmunización del Adulto. 2023

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.

Photoactive Red Fluorescent SiO2 Nanoparticles Based on Controlled Methylene Blue Aggregation in Reverse Microemulsions.

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.

Experiencia en el manejo del ataque cerebrovascular isquémico en dos centros de tercer nivel de la ciudad de Ibagué (Colombia) entre junio del 2019 y junio del 2020 / Ischemic stroke management - Experience in two third-level hospitals in Ibague (Colombia) from June 2019 to June 2020

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.

Pseudoatetosis de los miembros superiores como manifestación del déficit de vitamina B12: a propósito de un caso / Pseudoathetosis of the upper limbs as a manifestation of vitamin B12 deficit: about a case

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.

Experiencias docentes del uso de la tecnología educativa en el marco de la pandemia por COVID-19 / Teaching experiences with the use of educative technology in the context of the pandemic by COVID-19 / Experiências de ensino do uso de tecnologia educacional no contexto da pandemia COVID-19

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.

Diagnostic performance of three non-invasive fibrosis scores (Hepamet, FIB-4, NAFLD fibrosis score) in NAFLD patients from a mixed Latin American population.

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.

Recomendaciones de diagnóstico y tratamiento del ataque cerebrovascular isquémico agudo durante la contingencia por covid-19 / Recommendations for diagnosis and treatment of the acute ischemic stroke during COVID-19 contingency

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.

Photophysics at Unusually High Dye Concentrations.

The study of the interaction of light with systems at high dye concentrations implies a great challenge because several factors, such as emission reabsorption, dye aggregation, and energy trapping, hinder rationalization and interpretation of the involved photophysical processes. Space constraints induce dye interaction even in the absence of ground state stabilization of dimers and oligomers. At distances on the order of 1 nm, statistical energy traps are usually observed. At longer distances, excited state energy transfer takes place. Most of these factors do not result in ground state spectroscopic changes. Rather, fluorescence phenomena such as inner filter effects, concentration-dependent Stokes' shifts, and changes in quantum yields and decay times are evidenced. Photophysical studies are commonly carried out at high dilution, to minimize dye-dye interactions and emission reabsorption, and in the absence of light scattering. Under these conditions, the physical description of the system becomes rather simple. Fluorescence and triplet quantum yields become molecular properties and can be easily related to ratios of rate constants. However, many systems containing dyes able to fulfill specific functions, whether man-made or biological, are far from being dilute and scattering-free. The photosynthetic apparatus is a paradigmatic example. It is clear that isolation of components allows gathering relevant information about complex systems. However, knowledge of the photophysical behavior in the unaltered environment is essential in most cases. Complexity generally increases when light scattering is present. Despite that, our experience shows that light scattering, when correctly handled, may even simplify the task of unraveling molecular parameters. We show that methods and models aiming at the determination and interpretation of fluorescence and triplet quantum yields as well as energy transfer efficiencies can be developed on the basis of simple light-scattering theories. Photophysical studies were extended to thin films and layer-by-layer assemblies. Procedures are presented for the evaluation of fluorescence reabsorption in concentrated fluid solutions up to the molar level, which are being applied to ionic liquids, in which the emitting species are the bulk ions. Fluorescence reabsorption models proved to be useful in the interpretation of the photophysics of living organisms such as plant leaves and fruits. These new tools allowed the assessment of chlorophyll fluorescence at the chloroplast, leaf and canopy levels, with implications in remote sensing and the development of nondestructive optical methods.

Photophysics of Xanthene Dyes at High Concentrations in Solid Environments: Charge Transfer Assisted Triplet Formation.

The photophysical behavior of two xanthene dyes, Eosin Y and Phloxine B, included in microcrystalline cellulose particles is studied in a wide concentration range, with emphasis on the effect of dye concentration on fluorescence and triplet quantum yields. Absolute fluorescence quantum yields in the solid-state were determined by means of diffuse reflectance and steady-state fluorescence measurements, whereas absolute triplet quantum yields were obtained by laser-induced optoacoustic spectroscopy and their dependence on dye concentration was confirmed by diffuse reflectance laser flash photolysis and time-resolved phosphorescence measurements. When both quantum yields are corrected for reabsorption and reemission of radiation, ΦF values decrease strongly on increasing dye concentration, while a less pronounced decay is observed for ΦT . Fluorescence concentration quenching is attributed to the formation of dye aggregates or virtual traps resulting from molecular crowding. Dimeric traps are however able to generate triplet states. A mechanism based on the intermediacy of charge-transfer states is proposed and discussed. Calculation of parameters for photoinduced electron transfer between dye molecules within the traps evidences the feasibility of the proposed mechanism. Results demonstrate that photoactive energy traps, capable of yielding dye triplet states, can be formed even in highly-concentrated systems with random dye distributions.

Morphological remarks in the ghost shrimp Callichirus seilacheri (Bott, 1955) (Decapoda, Callianassidae) / Observações morfológicas no camarão-fantasma Callichirus seilacheri (Bott, 1955) (Decapoda, Callianassidae)

Callichirus seilacheri (Bott, 1955) is considered one of the most common ghost shrimps in the intertidal zone of sandy beaches along the eastern tropical Pacific. The present study provides new observations on the morphology of C. seilacheri, based on the revision of abundant material collected along the Pacific coast of Central America, including specimens from the type locality (Playa Los Blancos, El Salvador) of this species. The new features of C. seilacheri include: carapace with low triangular rostrum, without setae on tip; pereiopod 1 highly dissimilar in adult males, but not in females and juveniles of both sexes; first pleopod sexually dimorphic; females with oval gonopores, each one of them on the ventral coxal segment of the third pereiopod, and extra genital pores on the ventral coxal segment of the fifth pereiopod, these latter non-functional (non connected with the ovaries). Apparently, the presence of extra gonopores in females of C. seilacheri is a vestigial character shared with other representatives of the same genus.

Callichirus seilacheri (Bott, 1955) é considerado um dos camarões-fantasmas mais comuns em zonas intertidais de praias arenosas, ao longo do Pacífico oriental tropical. O presente estudo fornece novas observações sobre a morfologia de C. seilacheri, com base numa revisão de material abundante coletado ao longo da costa do Pacífico, na América Central, incluindo espécimes da localidade tipo desta espécie (Playa Los Blancos, El Salvador). As características inéditas de C. seilacheri, incluem: carapaça com pequeno rostro triangular, e sem cerdas na extremidade; Pereiópodos 1 muito desiguais em machos adultos, mas não nas fêmeas e juvenis, de ambos os sexos; Primeiro pleópodo sexualmente dimórfico; Fêmeas com gonóporos ovais, cada um na porção ventral da coxa do terceiro par de pereiópodos, e poros genitais extras na porção ventral da coxa do quinto pereiópodo, estes últimos não funcionais (não conectados aos ovários). Aparentemente, a presença de gonóporos extras em fêmeas de C. seilacheri é um caráter vestigial, compartilhado com outros representantes do mesmo gênero.

Morphological remarks in the ghost shrimp Callichirus seilacheri (Bott, 1955) (Decapoda, Callianassidae) / Observações morfológicas no camarão-fantasma Callichirus seilacheri (Bott, 1955) (Decapoda, Callianassidae)

Callichirus seilacheri (Bott, 1955) is considered one of the most common ghost shrimps in the intertidal zone of sandy beaches along the eastern tropical Pacific. The present study provides new observations on the morphology of C. seilacheri, based on the revision of abundant material collected along the Pacific coast of Central America, including specimens from the type locality (Playa Los Blancos, El Salvador) of this species. The new features of C. seilacheri include: carapace with low triangular rostrum, without setae on tip; pereiopod 1 highly dissimilar in adult males, but not in females and juveniles of both sexes; first pleopod sexually dimorphic; females with oval gonopores, each one of them on the ventral coxal segment of the third pereiopod, and extra genital pores on the ventral coxal segment of the fifth pereiopod, these latter non-functional (non connected with the ovaries). Apparently, the presence of extra gonopores in females of C. seilacheri is a vestigial character shared with other representatives of the same genus.(AU)

Callichirus seilacheri (Bott, 1955) é considerado um dos camarões-fantasmas mais comuns em zonas intertidais de praias arenosas, ao longo do Pacífico oriental tropical. O presente estudo fornece novas observações sobre a morfologia de C. seilacheri, com base numa revisão de material abundante coletado ao longo da costa do Pacífico, na América Central, incluindo espécimes da localidade tipo desta espécie (Playa Los Blancos, El Salvador). As características inéditas de C. seilacheri, incluem: carapaça com pequeno rostro triangular, e sem cerdas na extremidade; Pereiópodos 1 muito desiguais em machos adultos, mas não nas fêmeas e juvenis, de ambos os sexos; Primeiro pleópodo sexualmente dimórfico; Fêmeas com gonóporos ovais, cada um na porção ventral da coxa do terceiro par de pereiópodos, e poros genitais extras na porção ventral da coxa do quinto pereiópodo, estes últimos não funcionais (não conectados aos ovários). Aparentemente, a presença de gonóporos extras em fêmeas de C. seilacheri é um caráter vestigial, compartilhado com outros representantes do mesmo gênero.(AU)

Association between Transverse Sinus Hypoplasia and Cerebral Venous Thrombosis: A Case-Control Study.

BACKGROUND: Hypoplasia of the transverse sinus (TS) is a common anatomical variation. However, the relationship between TS hypoplasia and venous thrombosis has not been studied. We analyzed the hypothesis that TS hypoplasia is a predisposing factor for ipsilateral thrombosis. MATERIALS AND METHODS: We retrospectively evaluated 20 confirmed cases with isolated TS thrombosis and 43 age- and sex-matched controls. TS thrombosis and hypoplasia were diagnosed using both computed tomography and magnetic resonance venography. Hypoplasia was defined as a TS diameter less than 50% of the cross-sectional diameter of the lumen of the distal superior sagittal sinus and by a bony groove ratio less than 1.02. Univariate analysis was performed to evaluate the association between TS hypoplasia and thrombosis. RESULTS: There were a total of 45 hypoplastic TS: 31 (49%) left hypoplastic TS (12 (60%) cases vs 19 (44%) controls (P = .24), and 14 (22%) right hypoplastic TS (9 (45%) cases vs 5 (12%) controls (P = .003). TS hypoplasia was more frequently found in cases (n = 18, 90.0%) than in controls (n = 22, 51.2%; relative risk 1.7, confidence interval [CI] 95% 1.3-2.4, P = .003). Hypoplastic TS and ipsilateral TS thrombosis showed a significant association (P = .002 for right and P = .008 for left TS hypoplasia) with relative risk of 3.8 (95% CI 1.3-10) for right and 7.5 (95% CI 1.1-48) for left hypoplasia. No significant association was found between hypoplastic TS and functional outcome at 30- or 90-day follow-up. CONCLUSION: TS hypoplasia might be a predisposing factor for ipsilateral TS thrombosis, but not for functional outcome.

Risk Factors for Unfavorable Outcomes in Surgically Treated Brainstem Cavernous Malformations.

OBJECTIVE: Brainstem cavernous malformations (BSCMs) account for up to 18% of all intracranial cavernous malformations. Due to their complex anatomic location, they represent a significant challenge for neurosurgeons. As such, the identification of risk factors associated with negative outcomes is of significant importance. We analyze a series of 50 cases of BSCMs treated surgically in order to identify risk factors for unfavorable outcomes. METHODS: Patients who underwent surgical resection of BSCM at our institution between 2000 and 2015 were retrospectively reviewed. Univariate and multivariable logistic regression models were used to identify predictors of unfavorable outcomes, defined as those with a modified Rankin score (mRs) of >2. RESULTS: Fifty Latin American patients, with a mean age of 35.85 ± 13.06 years, consisting of 29 females (58%) and 21 males (42%), underwent surgical resection. Mean modified Rankin Scale (mRs) score at admission was 2.6 ± 1.05, and the mean BCSM size was 18.00 ± 7.19 mm. The rate of gross total resection was 92%. Overall, 80% of patients showed improved or unchanged clinical status at the last follow-up period; however, only 58% of patients had a favorable outcome with a mean mRs of 2.33 ± 1.136. Multivariable logistic binary regression identified hemorrhagic recurrence (P = 0.040), lower cranial nerve deficit (P = 0.019), and BSCMs >15 mm in diameter (P = 0.006) as predictive factors for unfavorable surgical outcomes. CONCLUSION: BSCM size, compromise of lower cranial nerves, and hemorrhagic recurrence before surgery were identified as risk factors associated with unfavorable outcomes of surgically treated BSCMs in this cohort.

Seguridad cardiovascular de los antidiabéticos orales / Cardiovascular safety of oral antidiabetics

Resumen La Diabetes Mellitus tipo 2 (DM-2) es un equivalente de riesgo cardiovascular. Existe una gran variedad de fármacos para el control de la glicemia en los pacientes con DM-2, los cuales tienen diferencias en su perfil cardiovascular, unos han demostrado un beneficio en la reducción de riesgo de eventos cardiovasculares, otros tienen un efecto neutro, y en el caso de otros fármacos como las sulfonilureas y las tiazolinedionas existe dudas sobre su seguridad cardiovascular. Sien do DM-2 un equivalente de riesgo coronario, es fundamental tomar en cuenta el perfil de riesgo cardiovascular de estos medicamentos a la hora de iniciar alguna de estas drogas y no solo su eficacia para controlar los niveles de glicemia. El objetivo de esta revisión es comentar sobre los estudios más recientes que evalúan el riesgo cardiovascular con el uso de los distintos antidiabéticos orales.

Abstract Cardiovascular Safety of Oral Antidiabetics Diabetes Mellitus type 2 (DM-2) is an equivalent of cardiovascular risk. There is a wide variety of drugs for the glycemic control in patients with DM-2, which have differences in their cardiovascular profile, some have shown a benefit in reducing the risk of cardiovascular events, others have a neutral effect, and in the case of other drugs such as sulfonylurea and thiazolidinedione, there are doubts about their cardiovascular safety. Being DM-2 an equivalent of coronary risk, it is essential to consider the cardiovascular risk profile of these medicines when starting any of these drugs and not only their effectiveness in controlling glycaemia levels. The objective of this review is to comment on the most recent studies evaluating cardiovascular risk with the use of different oral antidiabetics.

Rebleeding and Outcome in Patients with Symptomatic Brain Stem Cavernomas.

PURPOSE: We sought to evaluate the long-term functional outcomes and identify the potential risk factors for rebleeding in patients with brain stem cavernous malformations (BCMs) who presented with hemorrhages and were surgically or conservatively treated and prospectively monitored. METHODS: From January 1990 to July 2015, we included patients with first hemorrhagic episodes secondary to single BCMs. Modified Rankin score (mRS) was used for neurological status assessment. Univariate and multivariate regression statistics were used to identify the risk factors for rebleeding. RESULTS: A total of 99 patients with BCMs hemorrhages were included (59 [59.6%] women, mean age 37± 13 years). As initial treatments, 37 patients (37.4%) underwent surgery and 62 (62.6%) received conservative treatment. The median follow-up was 3.33 years (interquartile range 1.16-7 years; 408.3 patient/years). The rebleeding rate by patient/year was 10% in conservatively treated patients. Deterioration was significantly more frequent in patients with rebleeding (p = 0.0001). At the end of the follow-up, the mRS were favorable in 49 patients (65.3%) without rebleeding, whereas only 8 (33.3%) with rebleeding evolved to favorable outcomes (p = 0.006). Lesion size >18 mm (hazards ratio, HR 3.34, 95% CI 1.54-7.26; p = 0.0001) and ventral location or crossing the brain stem's midpoint (HR 2.5, 95% CI 1.14-5.46; p = 0.022) were associated with a major risk of rebleeding in the univariate analysis, but only a lesion >18 mm remained statistically significant (HR 2.7, 95% CI 1.2-6.21; p = 0.016) in the multivariate analysis. CONCLUSION: A lesion size >18 mm was the principal factor associated with hemorrhage recurrence. The overall functional outcome was good. However, significant morbidity was attributable to rebleeding.

Rose bengal in poly(2-hydroxyethyl methacrylate) thin films: self-quenching by photoactive energy traps.

The effect of dye concentration on the fluorescence,ΦF, and singlet molecular oxygen,ΦΔ, quantum yields of rose bengal loaded poly(2-hydroxyethyl methacrylate) thin films (∼200 nm thick) was investigated, with the aim of understanding the effect of molecular interactions on the photophysical properties of dyes in crowded constrained environments. Films were characterized by absorption and fluorescence spectroscopy, singlet molecular oxygen (1O2) production was quantified using a chemical monitor, and the triplet decay was determined by laser flash-photolysis. For the monomeric dilute dye, ΦF = 0.05 ± 0.01 and ΦΔ = 0.76 ± 0.14. The effect of humidity and the photostability of the dye were also investigated. Spectral changes in absorption and fluorescence in excess of 0.05 M and concentration self-quenching after 0.01 M are interpreted in the context of a quenching radius model. Calculations of energy migration and trapping rates were performed assuming random distribution of the dye. Best fits of fluorescence quantum yields with concentration are obtained in the whole concentration range with a quenching radius r Q = 1.5 nm, in the order of molecular dimensions. Agreement is obtained only if dimeric traps are considered photoactive, with an observed fluorescence quantum yield ratio ΦF,trap/ΦF,monomer ≈ 0.35. Fluorescent traps are capable of yielding triplet states and 1O2. Results show that the excited state generation efficiency, calculated as the product between the absorption factor and the fluorescence quantum yield, is maximized at around 0.15 M, a very high concentration for random dye distributions. Relevant information for the design of photoactive dyed coatings is provided.

Steady-State Fluorescence of Highly Absorbing Samples in Transmission Geometry: A Simplified Quantitative Approach Considering Reabsorption Events.

A simplified methodology to acquire steady-state emission spectra and quantum yields of highly absorbing samples is presented. The experimental setup consists of a commercial spectrofluorometer adapted to transmission geometry, allowing the detection of the emitted light at 180° with respect to the excitation beam. The procedure includes two different mathematical approaches to describe and reproduce the distortions caused by reabsorption on emission spectra and quantum yields. Toluene solutions of 9,10-diphenylanthracence, DPA, with concentrations ranging between 1.12 × 10-5 and 1.30 × 10-2 M, were used to validate the proposed methodology. This dye has significant probability of reabsorption and re-emission in concentrated solutions without showing self-quenching or aggregation phenomena. The results indicate that the reabsorption corrections, applied on molecular emission spectra and quantum yields of the samples, accurately reproduce experimental data. A further discussion is performed concerning why the re-emitted radiation is not detected in the experiments, even at the highest DPA concentrations.