Estrategia multimodal para la prevención de COVID-19, en una faena minera

Introducción: Al inicio de la pandemia de COVID-19, las empresas mineras, debieron implementar sistemas de gestión para prevenir transmisión de SARS-CoV-2. Objetivo: Describir los resultados iniciales de la estrategia multimodal para la prevención de COVID-19, en una faena minera. Materiales y Métodos: Estudio descriptivo, de corte transversal. Se estructuró un sistema de gestión que consideró medidas administrativas, ambientales, tamizaje de riesgos y gestión de casos de riesgo al interior de la empresa. Análisis de datos con estadística descriptiva. Resultados: Las medidas administrativas se tradujeron en que 8.116 (34%) trabajadores de la faena fueron suspendidos de sus labores habituales. El tamizaje de riesgo antes del ingreso a la faena identificó 450 casos sospechosos que fueron derivados a su domicilio. En el procedimiento de gestión de casos 1.073 personas fueron clasificadas en algunos de los grupos de riesgo. Se detectaron 10 casos de trabajadores con RPC positiva, siendo que 50% fue asintomático; en los sintomáticos, los síntomas más frecuentes fueron: tos (60%) y cefalea (40%). Conclusiones: Estos resultados, dan luces sobre la importancia de implementar una estrategia multimodal, adaptada a la realidad local de una empresa de la gran minería, para prevenir la transmisión de SARS-CoV-2.

Background: Mining companies must implement management systems dedicated to health and safety at work to prevent the transmission of SARS-CoV-2 among their workers, however, the literature on this is scarce. Aim: To describe a multimodal strategy for the management of health and safety at work, to address the risk of COVID-19 in large mining. Methods: Descriptive cross-sectional study, carried out in a large mining company. A management system was structured that considered administrative measures, of an environmental nature, risk screening, and management of risk cases within the company. The data analysis was done using descriptive statistics. Results: The administrative measures resulted in 8,116 (34%) workers at the site being suspended from their usual work. Risk screening before entering the site identified 450 suspected cases that were referred to their home. In the case management procedure, 1,073 people were classified in some of the risk groups. 10 cases of workers with PCR were detected in the follow-up period. Environmental measures were not very sensitive. Conclusions: These results shed light on the importance of implementing a multimodal strategy, adapted to the local reality, in preventing the spread of SARS-CoV-2 in the period under study, at the mining site intervened.

Green Synthesis of Gold and Silver Nanoparticles Using Leaf Extract of Capsicum chinense Plant.

So far, several studies have focused on the synthesis of metallic nanoparticles making use of extracts from the fruit of the plants from the genus Capsicum. However, as the fruit is the edible, and highly commercial, part of the plant, in this work we focused on the leaves, a part of the plant that is considered agro-industrial waste. The biological synthesis of gold (AuNPs) and silver (AgNPs) nanoparticles using aqueous extracts of root, stem and leaf of Capsicum chinense was evaluated, obtaining the best results with the leaf extract. Gold and silver nanoparticles synthesized using leaf extract (AuNPs-leaf and AgNPs-leaf, respectively) were characterized by UV-visible spectrophotometry (UV-Vis), Fourier Transform Infrared Spectroscopy with Attenuated Total Reflection (FTIR-ATR), X-ray Photoelectron Spectroscopy (XPS), Ultra Hight Resolution Scanning Electron Microscopy coupled to Energy-Dispersive X-ray spectroscopy (UHR-SEM-EDX) and Transmission Electron Microscopy (TEM), and tested for their antioxidant and antimicrobial activities. In addition, different metabolites involved in the synthesis of nanoparticles were analyzed. We found that by the use of extracts derived from the leaf, we could generate stable and easy to synthesize AuNPs and AgNPs. The AuNPs-leaf were synthesized using microwave radiation, while the AgNPs-leaf were synthesized using UV light radiation. The antioxidant activity of the extract, determined by ABTS, showed a decrease of 44.7% and 60.7% after the synthesis of the AuNPs-leaf and AgNPs-leaf, respectively. After the AgNPs-leaf synthesis, the concentration of polyphenols, reducing sugars and amino acids decreased by 15.4%, 38.7% and 46.8% in the leaf extract, respectively, while after the AuNPs-leaf synthesis only reducing sugars decreased by 67.7%. These results suggest that these groups of molecules are implicated in the reduction/stabilization of the nanoparticles. Although the contribution of these compounds in the synthesis of the AuNPs-leaf and the AgNPs-leaf was different. Finally, the AgNPs-leaf inhibited the growth of S. aureus, E. coli, S. marcescens and E. faecalis. All of them are bacterial strains of clinical importance due to their fast antibiotic resistance development.

Giant gastric lipoma as an uncommon cause of upper gastrointestinal bleeding.

A 52-year-old male patient presented to the Emergency Room due to melena. A gastroscopy was performed, which revealed a submucosal lesion in the antrum of the stomach. The lesion was lined with regular smooth mucosa except for an apical ulceration. Histology showed gastric mucosa with foveolar hyperplasia. Abdominal computed tomography (CT) showed a homogeneous, well-delimited fat-density mass measuring 5.9 x 4.3 cm. Laparoscopic surgery then found a solid tumor involving the whole thickness of the anterior wall at the prepyloric area, which was resected. Microscopic examination revealed a homogeneous, soft, ulcerated submucosal mass of yellowish adipose tissue that was 5 x 5 x 2 cm in size. Microscopically, the tumor was composed of mature fatty tissue with fibrous septa, and was partially encapsulated and circumscribed. It was reported as a submucosal lipoma. The patient had a favorable outcome.

Utilidad de la elastografía cuantitativa por ultrasonografía endoscópica (USE) para el diagnóstico de las lesiones sólidas del páncreas (LSP) / Utility of quantitative elastography by Endoscopic Ultrasound (EUS) to diagnose solid pancreatic lesions (SPL)

Resumen Introducción: la punción con aguja fina guiada por ultrasonografía endoscópica (PAF-USE) permite un diagnóstico de las lesiones sólidas del páncreas (LSP) con una sensibilidad de alrededor del 85 % en la literatura mundial y aún más baja en nuestro medio, por lo cual se requiere explorar nuevos accesorios (agujas) o técnicas tales como la elastografía, que mejoren esta sensibilidad. Esta última permite la cuantificación de la rigidez del tejido con altos grados de precisión y desde 2001 se ha aplicado al diagnóstico de tumores sólidos de diversos órganos como mama y tiroides, músculo, entre otros; y desde 2006 se ha empleado para las LSP y ha demostrado su utilidad como complemento a las herramientas diagnósticas disponibles, ya que mejora la precisión de la biopsia por PAF-USE al seleccionar el área más sospechosa para ser puncionada y también guía el manejo clínico cuando la PAF-USE es negativa o no concluyente. Objetivo: evaluar el rendimiento diagnóstico de la elastografía cuantitativa de strain ratio (SR) obtenida por ecoendoscopia en las LSP teniendo como patrón de oro el diagnóstico citopatológico. Métodos: 71 pacientes (rango de edad: 35-89, media: 62,2 años); de estos, 35 mujeres fueron sometidas a USE para la evaluación de LSP. El diseño del estudio fue de corte transversal, prospectivo y de un solo centro. La USE se realizó con un ecoendoscopio Pentax lineal y un procesador Hitachi-Noblus. La lesión (área A) y un área de referencia B se seleccionaron para calcular la relación de deformación (B/A, SR expresada en %). Se tomó como punto de corte SR para definir las lesiones malignas (duras) SR > 22 teniendo en cuenta la evidencia actualmente disponible; estos resultados se compararon con la citopatología de las muestras obtenidas por punción guiada por USE. Después de la aplicación de criterios de exclusión, se realiza el análisis estadístico de 56 pacientes y se considera el valor p < 0,05. Se calculó la sensibilidad, especificidad, valor predictivo positivo (VPP), valor predictivo negativo (VPN) y precisión diagnóstica comparando la elastografía SR con los diagnósticos finales por citopatología. Resultados: la elastografía cuantitativa SR (%) permite detectar las LSP malignas con sensibilidad del 94,6 % (intervalo de confianza [IC] del 95 %: 85,4 %-98,2 %), especificidad del 89,3 % (IC 95 %: 78,5 %-95,0 %), VPP del 89,8 % (IC 95 %: 79,5 %-95,3 %); VPN del 94,3 % (IC 95 %: 84,6 %-98,1 %) y exactitud del 92,0 % (IC 95 %: 85,4 %-95,7 %). Conclusión: la elastografía cuantitativa SR por USE en LSP es un complemento útil que mejora la precisión de la PAF-USE al seleccionar el área más sospechosa para ser puncionada y guiar el manejo clínico cuando la PAF-USE es negativa o no concluyente, ya que tiene una alta sensibilidad y especificad en el diagnóstico de las LSP malignas.

Abstract Introduction: Endoscopic ultrasonography with fine-needle aspiration allows performing a diagnosis of solid pancreatic lesions with an approximate 85% sensitivity, as referenced in specialized literature, and even lower sensitivity as per local research. To yield better sensitivity and to improve the results, it is required to examine new elements (needles) and techniques like elastography. Elastography helps in the quantification of tissue stiffness with a high level of accuracy. Since 2001, elastography has been applied in diagnosing solid forms of cancer (tumors) that affect organs like breasts, the thyroid, and some muscles. This method which has been used to diagnose solid pancreatic lesions (SPL) since 2006 has proved to be useful as a complementary method to the existing diagnostic techniques. It improves the accuracy of the endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) by selecting the more suspicious area to be punctured, and it also guides the clinical treatment after getting a negative EUS-FNA or a non-conclusive result. Objective: To evaluate the diagnostical performance of the strain ratio (SR) quantitative elastography by ecoendoscopy in solid pancreatic lesions, considering the cytopathologic diagnostic as the gold standard. Methods: 71 patients (age range: 35-89 years old, mean: 62.2 years old); out of those 71 patients, The EUS to diagnose SPL, was performed on 35 women. This was a single-center, prospective cross-sectional study design. The EUS was performed with a Pentax linear endoscope and a Hitachi-Noblus ultrasound. The lesion (area A) and a reference area B were selected to calculate the deformation ratio (B/A, SR expressed as a percentage). SR > 22 was selected as a cut-off point to determine the malignant lesions (solid lesions), considering the evidence currently available. The results were compared with their cytopathology interpretation once that the EUS was performed. After the exclusion criteria was applied, a statistical analysis of 56 patients was performed, considering p < 0,05. The sensitivity, the specificity, the positive predictive value (PPV), the negative predictive value (NPV) and the diagnostic accuracy, were calculated, comparing the elastography SR with the final diagnostics with the cytopathology interpretation. Results: Quantitative elastography SR (%) allows to detect the malignant SPL with sensitivity 94.6% (95% confidence interval [CI]: 85.4%-98.2%), specificity of 89.3% (CI 95%: 78,5 %-95,0 %), PPV of 89.8% (CI 95 %: 79,5 %-95,3 %); NPV of 94.3% (IC 95 %: 84,6 %-98,1 %) and an accuracy of 92.0% (CI 95 %: 85,4 %-95,7 %). Conclusion: SR quantitative elastography by Endoscopic Ultrasound, EUS is a suitable complement method that improves the EUS-FNA accuracy, by selecting the most suspicious area to be punctured, and it also guides clinical treatment after getting a negative EUS-FNA or a non-conclusive result, due to its high sensitivity and specificity levels to diagnose malignant SPL.

Detección automática de pólipos colorrectales con técnicas de inteligencia artificial / Artificial intelligence techniques for the automatic detection of colorectal polyps

Resumen El cáncer colorrectal (CCR) es uno de los tumores malignos con mayor prevalencia en Colombia y el mundo. Estas neoplasias se originan en lesiones adenomatosas o pólipos que deben resecarse para prevenir la enfermedad, lo cual se puede realizar con una colonoscopia. Se ha reportado que durante una colonoscopia se detectan pólipos en el 40 % de los hombres y en el 30 % de las mujeres (hiperplásicos, adenomatosos, serrados, entre otros), y, en promedio, un 25 % de pólipos adenomatosos (principal indicador de calidad en colonoscopia). Sin embargo, estas lesiones no son fáciles de observar por la multiplicidad de puntos ciegos en el colon y por el error humano asociado con el examen. Diferentes investigaciones han reportado que alrededor del 25 % de pólipos colorrectales no son detectados o se pasan por alto durante la colonoscopia y, como consecuencia, el paciente puede tener un cáncer de intervalo. Estas cifras muestran la necesidad de contar con un segundo observador (sistema de inteligencia artificial) que reduzca al mínimo la posibilidad de no detectar estos pólipos y, de este modo, sea posible prevenir al máximo el cáncer de colon. Objetivo: crear un método computacional para la detección automática de pólipos colorrectales usando inteligencia artificial en videos grabados de procedimientos reales de colonoscopia. Metodología: se usaron bases de datos públicas con pólipos colorrectales y una colección de datos construida en un Hospital Universitario. Inicialmente, se normalizan todos los cuadros de los videos para disminuir la alta variabilidad entre bases de datos. Posteriormente, la tarea de detección de pólipos se hace con un método de aprendizaje profundo usando una red neuronal convolucional. Esta red se inicia con pesos aprendidos en millones de imágenes naturales de la base de datos ImageNet. Los pesos de la red se actualizan usando imágenes de colonoscopia, siguiendo la técnica de ajuste fino. Finalmente, la detección de pólipos se realiza asignando a cada cuadro una probabilidad de contener un pólipo y determinando el umbral que define cuando el pólipo se encuentra presente en un cuadro. Resultados: este enfoque fue entrenado y evaluado con 1875 casos recopilados de 5 bases de datos públicas y de la construida en el hospital universitario, que suman aproximadamente 123 046 cuadros. Los resultados obtenidos se compararon con las marcaciones de diferentes expertos en colonoscopia y se obtuvo 0,77 de exactitud, 0,89 de sensibilidad, 0,71 de especificidad y una curva ROC (receiver operating characteristic) de 0,87. Conclusión: este método logra detectar pólipos de manera sobresaliente, superando la alta variabilidad dada por los distintos tipos de lesiones, condiciones diferentes de la luz del colon (asas, pliegues o retracciones) con una sensibilidad muy alta, comparada con un gastroenterólogo experimentado, lo que podría hacer que se disminuya el error humano, el cual es uno de los principales factores que hacen que no se detecte o se escapen los pólipos durante un examen de colonoscopia.

Abstract Colorectal cancer (CRC) is one of the most prevalent malignant tumors worldwide. These neoplasms originate from adenomatous lesions or polyps that must be resected to prevent the development of the disease, and that can be done through a colonoscopy. Polyps are reported during colonoscopy in 40% of men and 30% of women (hyperplastic, adenomatous, serrated, among others), and, on average 25% are adenomatous polyps (the main indicator of quality in colonoscopy). However, these lesions are not easy to visualize because of the multiplicity of blind spots in the colon and human errors associated with the performance of the procedure. Several research works have reported that about 25% of colorectal polyps are overlooked or undetected during colonoscopy, and as a result, the patient may have interval cancer. These figures show the need for a second observer (artificial intelligence system) to reduce the possibility of not detecting polyps and prevent colon cancer as much as possible. Objective: To create a computational method for the automatic detection of colorectal polyps using artificial intelligence using recorded videos of colonoscopy procedures. Methodology: Public databases of colorectal polyps and a data collection constructed in a university hospital were used. Initially, all the frames in the videos were normalized to reduce the high variability between databases. Subsequently, polyps were detected using a deep learning method with a convolutional neural network. This network starts with weights learned from millions of natural images taken from the ImageNET database. Network weights are updated using colonoscopy images, following the fine-tuning technique. Finally, polyps are detected by assigning each box a probability of polyp presence and determining the threshold that defines when the polyp is present in a box. Results: This approach was trained and evaluated with 1 875 cases collected from 5 public databases and the one built in the university hospital, which total approximately 123 046 frames. The results obtained were compared with the markings of different experts in colonoscopy, obtaining 0.77 accuracy, 0.89 sensitivity, 0.71 specificity, and a receiver operating characteristic curve of 0.87. Conclusion: This method detected polyps in an outstanding way, overcoming the high variability caused by the types of lesions and bowel lumen condition (loops, folds or retractions) and obtaining a very high sensitivity compared with an experienced gastroenterologist. This may help reduce the incidence of human error, as it is one of the main factors that cause polyps to not be detected or overlooked during a colonoscopy.

One-step synthesis of gold and silver non-spherical nanoparticles mediated by Eosin Methylene Blue agar.

Nowadays, there are several approaches reported to accomplish the green synthesis of metal nanoparticles by using bacterial and fungi supernatants or by-products generated by these microorganisms. Therefore, agars as solely reductive regents have started to be used in order to obtain metal nanoparticles. This paper shows the results of the synthesis of gold and silver nanoparticles with different morphology, mainly triangular and truncated triangular, using Eosin Methylene Blue (EMB) agar as reducing agent. To control the reaction process, the necessary activation energy for the reducer was provided by three different techniques: microwave radiation, using a domestic microwave oven, ultraviolet radiation, and heating on a conventional plate. The evolution of the reduction process and stability of the samples was performed by ultraviolet visible spectroscopy. Morphology was carefully analyzed using high-resolution transmission electron microscopy (HRTEM) and Transmission electron microscopy (TEM). A one step synthesis for gold and silver nanoparticles was optimized with an eco-friendly and economic process.

A General One-Pot Methodology for the Preparation of Mono- and Bimetallic Nanoparticles Supported on Carbon Nanotubes: Application in the Semi-hydrogenation of Alkynes and Acetylene.

A facile and straightforward methodology for the preparation of monometallic (copper and palladium) and bimetallic nanocatalysts (NiCu and PdCu) stabilized by a N-heterocyclic carbene ligand is reported. Both colloidal and supported nanoparticles (NPs) on carbon nanotubes (CNTs) were prepared in a one-pot synthesis with outstanding control on their size, morphology and composition. These catalysts were evaluated in the selective hydrogenation of alkynes and alkynols. PdCu/CNTs revealed an efficient catalytic system providing high selectivity in the hydrogenation of terminal and internal alkynes. Moreover, this catalyst was tested in the semi-hydrogenation of acetylene in industrially relevant acetylene/ethylene-rich model gas feeds and showed excellent stability even after 40 h of reaction.

Chiral Imidazolium-Functionalized Au Nanoparticles: Reversible Aggregation and Molecular Recognition.

Gold nanoparticles (AuNPs) stabilized by imidazolium salts derived from amino acids [glycine (1), rac-alanine (2), l-phenylalanine (3), and rac-methionine (4)] were prepared. The AuNPs were stabilized the most by 4, which kept the particles dispersed in water for months at pH > 5.5. These AuNPs exhibited a well-defined absorption band at 517 nm and had an average particle size of 11.21 ± 0.07 nm. The 4-AuNPs were reversibly aggregated by controlling the pH of the solution. Chiral R,R-4-AuNPs and S,S-4-AuNPs were synthesized, and the chiral environment on the nanoparticle surface was confirmed using circular dichroism; these nanoparticles exhibited a molecular recognition of chiral substrates. Furthermore, they showed potential for separating racemic mixtures when supported on a layered double hydroxide.

Conocimientos, actitudes y prácticas sobre las geohelmintiasis en una comunidad rural de Colombia / Conhecimentos, atitudes e práticas de moradores de uma comunidade rural da Colômbia sobre as geohelmintoses / Knowledge, attitudes and practices about the soil transmitted helminths in a rural community of Colombia

Las geohelmintiasis son un grupo de enfermedades desatendidas que afectan especialmente a la población infantil de países en vía de desarrollo. En este artículo se muestran los resultados de un trabajo cuyo objetivo fue explorar y describir los conocimientos, actitudes y prácticas sobre las geohelmintiasis en niños y padres de una población rural colombiana, como base para el diseño de un programa de educación en salud. Este es un estudio cualitativo, etnográfico, realizado en la población de La Virgen, (Colombia), cuya validez estuvo dada por la triangulación y su confiabilidad por la concordancia interpretativa, mediante la participación de varios investigadores. Se utilizaron las técnicas de encuesta, entrevistas, grupos de discusión, círculos de reflexividad y observación participante. Los datos de la encuesta se procesaron con el Programa EpiInfo VI y los cualitativos con el Atlas-ti 5.0.66. Aunque los participantes identificaron los factores de riesgo para las geohelmintiasis, no asociaron la infección con contaminación del suelo con los huevos o larvas de los helmintos, pero si con otras acciones, como el consumo de guayaba. Identificaron como manifestaciones clínicas el bruxismo, dolor abdominal, diarrea, y una entidad popularmente denominada "rebote de lombrices". Ellos emplean terapéuticas tradicionales como el paico (Chenopodium ambrosioides), pero también acostumbran a llevar los niños al médico cada seis meses para la desparasitación. Este estudio muestra que los factores de riesgo no deben ser exclusivamente considerados en términos de individuos o de determinantes sociales desarticulados (sexo, edad, nivel socioeconómico), sino dentro de un contexto sociocultural con un potencial explicativo fundamental que permite entender las condiciones bioculturales en que se instalan y prosperan estas infecciones...

Geohelminthiasis are a group of soil-transmitted parasitic diseases that specially affect children in the developing world. This article shows the results of a work which aimed to explore and to describe the knowledge, attitudes and practices regarding geohelminthiasis in children and parents from a Colombian rural area, in order to design a health education program. It was an ethnographic, qualitative study, undertaken in La Virgen, Cundinamarca, Colombia. The validity was given by the triangulation and its confiability from the interpretative concordance using the information obtained from different sources and researchers. The techniques used were interviews, survey, discussion groups, reflexivity groups and observations in situ. Survey data were processed in EpiInfo VI and interviews data were organized using Atlas-ti 5.0.66. Participants identified the risk factors for geohelminth infection, but they do not associate soil contamination with helminths eggs or larvae with the risk to acquire the infection, instead of that they think the infection could be acquired by eating guava, because they think guava worm is alike a geohelminth. Participans identified as clinical signs bruxism, abdominal pain, diahrrea, and an illness called "rebote de lombrices" (sort of "worm riot") by people. Mothers use some traditional therapeutics like "paico" (Chenopodium ambrosioides), but they also use to visit the physician at least twice a year, to get medicine against geohelminths. This study shows that risk factors should not be considered solely in terms of individuals or disjointed of social determinants (sex, age, socioeconomic status), but within a societal context with a fundamental explanatory potential that allows understanding bio-cultural conditions where are installed and thrive these infections...

As geohelmintoses pertencem ao grupo das doenças negligenciadas, que afetam especialmente a população infantil nos países em desenvolvimento. Neste trabalho, mostra os resultados de um estudo que visa explorar e descrever os conhecimentos, atitudes e práticas sob as geohelmintoses na Colombia em uma comunidade rural nos pais e crianças como base para projetar um programa de educação em saúde. Esta é uma pesquisa qualitativa, etnográfica, realizada no povoado de La Virgen, (Colômbia), cuja validade foi dada pela triangulação ea sua fiabilidade pela coerência de interpretação, com a participação de vários pesquisadores. Nós usamos técnicas de inquérito, entrevistas, grupos focais, os círculos de reflexão e observação participante. Os dados do inquérito foram processados com o programa EpiInfo VI e os dados qualitativos com o 5,0 Atlas-ti. Os participantes identificaram os fatores de risco para geohelmintoses, embora não associando com a contaminação do solo com ovos ou larvas de helmintos, com o risco de infecção, porem associando com outras ações, tais como o consumo de goiaba. Foram identificadas manifestações clínicas como "bruxismo", dor abdominal, diarréia, e apareceu uma doença conhecida popularmente como "rebote de lombrices". Eles usam as terapias tradicionais, como paico (Chenopodium ambrosioides), mas também tendem a levar as crianças ao médico a cada seis meses para a desparasitação.Este estudo mostra que fatores de risco não devem ser apenas considerada em termos de indivíduos ou desarticulados determinantes sociais (sexo, idade, status socioeconômico), além disso dentro de um contexto cultural com potencial explicativo fundamental que nos ajuda a compreender as condições culturais em que essas infecções se estabelecem e se desenvolvem...