Pesquisa | SciELO

ABSTRACT The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement, published in 2009, was designed to help systematic reviewers transparently report why the review was done, what the authors did, and what they found. Over the past decade, advances in systematic review methodology and terminology have necessitated an update to the guideline. The PRISMA 2020 statement replaces the 2009 statement and includes new reporting guidance that reflects advances in methods to identify, select, appraise, and synthesise studies. The structure and presentation of the items have been modified to facilitate implementation. In this article, we present the PRISMA 2020 27-item checklist, an expanded checklist that details reporting recommendations for each item, the PRISMA 2020 abstract checklist, and the revised flow diagrams for original and updated reviews.

RESUMO A declaração dos Principais Itens para Relatar Revisões Sistemáticas e Meta-análises (PRISMA), publicada em 2009, foi desenvolvida para ajudar revisores sistemáticos a relatar de forma transparente por que a revisão foi feita, os métodos empregados e o que os autores encontraram. Na última década, os avanços na metodologia e terminologia de revisões sistemáticas exigiram a atualização da diretriz. A declaração PRISMA 2020 substitui a declaração de 2009 e inclui novas orientações para relato que refletem os avanços nos métodos para identificar, selecionar, avaliar e sintetizar estudos. A estrutura e apresentação dos itens foram modificadas para facilitar a implementação. Neste artigo, apresentamos a lista de checagem PRISMA 2020 de 27 itens, uma lista de checagem expandida que detalha as recomendações para relato para cada item, a lista de checagem PRISMA 2020 para resumos e os fluxogramas revisados para novas revisões e para atualização de revisões.

RESUMEN La declaración PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses), publicada en 2009, se diseñó para ayudar a los autores de revisiones sistemáticas a documentar de manera transparente el porqué de la revisión, qué hicieron los autores y qué encontraron. Durante la última década, ha habido muchos avances en la metodología y terminología de las revisiones sistemáticas, lo que ha requerido una actualización de esta guía. La declaración PRISMA 2020 sustituye a la declaración de 2009 e incluye una nueva guía de presentación de las publicaciones que refleja los avances en los métodos para identificar, seleccionar, evaluar y sintetizar estudios. La estructura y la presentación de los ítems ha sido modificada para facilitar su implementación. En este artículo, presentamos la lista de verificación PRISMA 2020 con 27 ítems, y una lista de verificación ampliada que detalla las recomendaciones en la publicación de cada ítem, la lista de verificación del resumen estructurado PRISMA 2020 y el diagrama de flujo revisado para revisiones sistemáticas.

https://doi.org/10.26633/rpsp.2022.112

Evaluación de la calidad del huevo marrón comercial del cantón La Troncal, Ecuador
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Vera Rodríguez M.Sc., José Humberto

; Cepeda Landin Ing., Wilson Eder

; Torres Ajila Tnlgo., Katherine Maribel

; Bueno Guallpa Tnlgo., Evelyn Katiusca

; Mendoza López Tnlgo., Carlos Alexander

; Merchan Pucha, Bolivar Taurino

; Carpio Gómez Tnlgo., Jennifer Jessenia

; Doris Mirella Tnlgo., Rivera Rivera

Revista colombiana de ciencia animal recia

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Dez 2020, Volume 12 Nº 2 Páginas 51 - 59

Resumo: Es En | Texto: Es En | PDF: Es | PDF: En

RESUMEN Se evaluó la calidad del huevo marrón comercial del cantón La Troncal, Ecuador. Se estudiaron un total de 1200 huevos (parroquia La Troncal, 400 huevos; parroquia Manuel J. Calle, 400 huevos y parroquia Pancho Negro, 400 huevos). Se realizó el análisis físico externo que incluye peso de huevo, espesor y peso de cáscara, y el análisis físico interno, que incluye diámetro, y altura de clara y de yema. Se clasificaron los huevos según color, peso y forma. Cada parroquia se consideró un tratamiento y las medias de las variables del análisis físico externo y del interno, fueron separadas utilizando la prueba de Tukey (p ≤0.05). Los colores 90, 100 y 110, fueron los más frecuentes. Según el peso del huevo, las categorías más frecuentes fueron extragrande (38%), grande (30%) y gigante (19%). Según la forma, la mayor frecuencia fue de huevos ovoides y redondos (92%), siendo más frecuentes, entre estas dos categorías, los huevos ovoides. Las aves de la parroquia Manuel J. Calle produjeron (p≤0.05) huevos más grandes, con mayor diámetro y altura de clara, con mayor altura de yema, con mayor peso y espesor de cáscara, color marrón más obscuro y principalmente huevos ovoides, mientras que las demás parroquias produjeron valores levemente inferiores. En conclusión, las parroquias de La Troncal, Ecuador, producen huevos grandes, con buen diámetro y altura de clara, y color francamente marrón, es decir producen huevos de muy buena calidad.

ABSTRACT The quality of commercial brown egg from the county La Troncal, Ecuador, was evaluated. A total of 1,200 eggs were studied (parish La Troncal, 400 eggs; parish Manuel J. Calle, 400 eggs and parish Pancho Negro, 400 eggs). The external physical analysis was performed, which includes egg weight, thickness and shell weight, and the internal physical analysis, which includes diameter, and height of white and yolk. Eggs were classified according to color, weight and shape. Each parish was considered a treatment and means of variables of the external and internal physical analyses were separated using the Tukey test (p≤0.05). Colors 90, 100 and 110 were the most frequent. According to egg weight, the most frequent categories were extralarge (38%), large (30%) and giant (19%). According to shape, the highest frequency was of ovoid and round eggs (92%), being more frequent, between these two categories, the ovoid eggs. Birds from Manuel J. Calle parish produced (p≤0.05) larger eggs, with greater diameter and white height, higher yolk height, greater weight and shell thickness, a darker brown color and mostly ovoid eggs, while the other parishes produced slightly lower values. In conclusion, the parishes of La Troncal, Ecuador, produce large eggs, with good diameter and white height, and a really brown color, that is, they produce very good quality eggs.

https://doi.org/10.24188/recia.v12.n2.2020.771 148 downloads

El principio de interés superior del niño en el marco jurídico ecuatoriano
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Paulette Murillo, Katherine

; Banchón Cabrera, Jennifer Katiusca

; Vilela Pincay, Wilson Exson

Revista Universidad y Sociedad

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Jun 2020, Volume 12 Nº 2 Páginas 385 - 392

Resumo: En Es | Texto: En Es | PDF: En | PDF: Es

ABSTRACT The objective of this descriptive study, of bibliographic revision type, is to analyze the principle of the higher interest of the child in the Ecuadorian legal framework. It is based on the qualitative approach, as well as the methods of scientific, historical-logical, exegetic research, bibliographical review, content analysis and analytical-synthetic. As a result of the analysis, a deep reflection, explanation and argumentation on this constitutional norm is obtained, which comes to eradicate the national and international legal void on the rights of children and adolescents. It is an indeterminate, subjective and flexible principle that leaves room for manipulation and makes its practical implementation difficult in the legal exercise in decision making. In spite of its limitations, it is present in the different Ecuadorian legal spheres, as the basis of the rules regarding children and adolescents.

RESUMEN El objetivo del presente estudio descriptivo, de tipo revisión bibliográfica, es analizar el principio de interés superior del niño en el marco jurídico ecuatoriano; se fundamenta en el enfoque cualitativo, así como en los métodos de la investigación científica, histórico-lógico, exegético, revisión bibliográfica, análisis de contenido y analítico-sintético. Como resultado del análisis se obtiene una profunda reflexión, explicación y argumentación sobre esta norma constitucional, que viene a erradicar el vacío legal nacional e internacional sobre los derechos de los niños, niñas y adolescentes; es un principio indeterminado, subjetivo y flexible que deja margen a las manipulaciones y hace difícil su implementación práctica en el ejercicio jurídico en la toma de decisiones; a pesar de sus limitaciones está presente en las diferentes esferas jurídicas ecuatorianas, como fundamento de las normas respecto a niños, niñas y adolescentes.

Improving warfarin therapy through implementation of a hospital-based pharmacist managed clinic in Jamaica
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Mckenzie, Jodi-Ann

; Wilson-Clarke, Cameil

; Prout, Jennifer

; Campbell, Jacqueline

; Douglas, Rhea-Danielle

; Gossell-Williams, Maxine

Pharmacy Practice (Granada)

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Dez 2018, Volume 16 Nº 4 elocation 1214

Resumo: En | Texto: En | PDF: En

Abstract Background: Pharmacist managed warfarin clinics can improve the anticoagulation status ofnon-valvular patients. The first of such services was implemented at the Cornwall Regional Hospital in Jamaica in 2013. Objectives: To assess the anticoagulation control of patients on warfarin therapy over six months in the pharmacist managed warfarin clinic at Cornwall Regional Hospital. Methods: Retrospective docket review for the period January 2014 to December 2016 was done to include data of patients attending routine clinic appointments for at least six months. Age, gender, date of visit, indication for warfarin therapy, warfarin dose and International Normalized Ratio readings were extracted. Percentage time spent in therapeutic range (TTR) was calculated by month for six months using the Rosendaal linear interpolation method. Patient anticoagulation status was categorized as poor (TTR<40%), moderate (TTR=40-64%) or good (TTR≥65%) and anticoagulation status at three months and six months was compared. Results: For the period of assessment, 52 patients were identified; the median age was 58 years and 36 patients were males. Deep vein thrombosis was the main indication for therapy (22 of 52) and median warfarin weekly dose ranged was 15.0-130 mg. At time of recruitment most of the patients were outside the target INR range (43 of 52). Within one month, the median TTR attained was 31% [IQR 62-10]. This significantly improved by second month to 60% [IQR 82-23] (p=0.001). By month three, the proportion of patients in good, moderate and poor anticoagulant status was 19/51, 15/51 and 17/51 respectively, which at six months changed to 23/51, 12/51. 16/51 respectively; thus, although coagulation status improved from month one to three, there was no significant improvement from month three to month six (p=0.31). Conclusions: The pharmacist managed warfarin clinic monitoring services were successful in attaining TTRs >40% and sustaining these values over six months. The services should therefore be encouraged.

https://doi.org/10.18549/pharmpract.2018.04.1214 265 downloads

Minority compounds and sensory analysis evaluation of Coffea arabica var. c aturra cultivated in three different altitudinal ranges
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Cruz-Bolivar, Jennifer Tatiana

; Rodríguez-Pérez, Wilson

; Suárez-Salazar, Juan Carlos

; Ordoñez-Espinosa, Claudia Mercedes

; Vega-Cano, Gustavo Adolfo

Acta Agronómica

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Jun 2017, Volume 66 Nº 2 Páginas 221 - 227

Resumo: Es En | Texto: Es En | PDF: Es | PDF: En

Resumen Se determinó la composición de compuestos minoritarios en muestras de café tostado y molido (Coffea arábica var. caturra), cultivado en tres rangos altitudinales 1300-1400, 1400-1600, 1600-1800 m. s. n. m., en el departamento del Huila. Se colectaron muestras en Julio de 2012 para analizar características como pH, acidez total titulable y composición de compuesto minoritarios previa esterificación y análisis por cromatografía de gases de alta resolución acoplado a espectrometría de masas. Así mismo, se realizó prueba de calidad de taza considerando los siguientes atributos: fragancia/aroma, sabor, sabor residual, acidez, cuerpo, uniformidad, balance, taza limpia y dulzor. El contenido de humedad para los diferentes rangos de altitud solamente presentó diferencia significativa (p˂0.05) a nivel de rango altitudinal. Se identificaron doce compuestos de la fracción insaponificable de café tostado y molido predominando estigmasterol, beta sitosterol, 4-metilpentanamida y 2-(2-Hidroxifenil) buta-1,3-dieno, en los rangos altitudinales evaluados. En la prueba de calidad de taza no se encontró diferencia significativa (p>0.05) en los atributos evaluados variando el rango altitudinal.

Abstract The composition of minority compounds in samples of roasted and ground coffee (Coffea arabica var. caturra) cultivated in three altitudinal ranges 1300-1400, 1400-1600, 1600-1800 m. a. s. l., in the Huila department of Colombia were determined. The samples were collected in July of 2012. pH, total acidity and total lipids were measured. Subsequently, the composition of total lipids after esterification and gas chromatography analysis coupled to high resolution mass spectrometry (GC-MS) was established. Quality cup test considering the following attributes: fragrance/aroma, taste, residual flavor, acidity, body, uniformity, balance, clean cup, sweetness, quality and note, were performed. No statistically significant difference (p <0.05) in pH, titratable acidity, total time of roasting and cracking time was determined. Significant difference was found in% humidity range: 1300-1400 m relative to the ranges: 1400-1600 and 1600-800 meters. As for the major compounds are predominantly: stigmasterol, sitosterol, 4-methylpentanamide and 2- (2-hydroxyphenyl) buta-1,3-diene, in the altitudinal ranges evaluated. No significant difference (p>0.05) was found in the evaluated attributes at the quality cup test at different altitudinal range.

https://doi.org/10.15446/acag.v66n2.58126 650 downloads

Efecto del contenido de oxígeno y metano en la cinética de oxidación de un carbonizado de carbón
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Múnera, Jennifer Laverde-

; Alvarado-Torres, Pedro Nel

; Machado, Wilson Ruiz-

Revista de la Academia Colombiana de Ciencias Exactas, Físicas y Naturales

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Mar 2017, Volume 41 Nº 159 Páginas 221 - 229

Resumo: Es En | Texto: Es En | PDF: Es | PDF: En

Resumen Se evaluó el efecto de la adición de metano en un carbonizado de carbón sometido a reacción con concentraciones de oxígeno bajas. Desde un punto de vista cinético, dicho efecto es determinando por la energía de activación (Ea) y por el factor preexponencial para diferentes concentraciones de oxígeno y mezclas de oxígeno y metano. Se preparó un carbonizado con un tamaño de partícula de 75 a 150 μm a partir de un carbón bituminoso altamente volátil, y se determinaron los parámetros cinéticos de la oxidación empleando el método termogravimétrico de velocidad máxima. Las variables evaluadas en la cinética de oxidación fueron la concentración de oxígeno (5, 8 y 21 %), y el efecto de la adición de metano en el medio de reacción (5, 10 y 14 % de metano mezclado con 5 % de oxígeno). Los resultados mostraron que la Ea disminuía al aumentar la concentración de oxígeno, en tanto que al agregar metano se observó un efecto promotor cuando este correspondía al 5 % de la mezcla total; sin embargo, cuando el porcentaje de metano aumentaba, la Ea también lo hacía debido a la rápida reacción del oxígeno con el metano en fase homogénea comparada con la reacción heterogénea del oxígeno con el carbonizado. La Ea obtenida con 5 % de oxígeno fue de 122,9 kJ/mol y con 21 %, de 90,69 kJ/mol; en presencia de metano al 5 % y 5 % de oxígeno, la Ea fue de 110,7 kJ/mol, y aumentó hasta 170,8 kJ/mol cuando el metano representaba el 14 % de la mezcla. © 2017. Acad. Colomb. Cienc. Ex. Fis. Nat.

Abstract In this work we evaluated the effect of adding methane during the oxidation process of a coal char with low oxygen concentration. We analyzed the effect from a kinetic point of view and we determined the activation energy (Ea) and the pre-exponential factor (A) with different oxygen concentrations and oxygen and methane mixtures. We used a coal char from a highly volatile bituminous coal with particle size of 75 to 150 μm; the kinetic parameters were determined by thermogravimetric method (TGA) with the high-velocity model; oxygen concentration variations were studied with 5, 8 and 21% of oxygen, as well as the effect of adding methane (5,10 and 14%) when oxidation occurred with 5% of oxygen. The results showed that the Ea decreased when oxygen concentration increased, and that adding 5% of methane to the total mixture enhanced the effect. Instead, when we increased the methane percentage, the Ea increased due to the rapid reaction of oxygen and methane in the homogeneous phase as compared with the heterogenous reaction of oxygen and coal char. With 5% oxygen the Ea value was 122.9 kJ/mol and with 21%, it was 90.69 kJ/mol; when methane was added at 5%, the Ea value was 110.7 kJ/mol, and it increased to 170.8 kJ/mol when there was 14% of methane in the mixture. © 2017. Acad. Colomb. Cienc. Ex. Fis. Nat.

https://doi.org/10.18257/raccefyn.452 5131 downloads

First reported enterovirus D68 infection in pediatric patients from the Caribbean region: evidence of spread from the U.S. outbreak
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Nathaniel, SueMin

; Ahmed, Shalauddin

; Wilson, Jennifer

; Gutierrez, Cristina

; Chadee, Dave D.

; Olowokure, Babatunde

; de Salazar, Pablo M.

Revista Panamericana de Salud Pública

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2017, Volume 41 elocation e11

Resumo: En Es | Texto: En Es | PDF: En | PDF: Es

ABSTRACT The 2014 enterovirus D68 (EV-D68) outbreak in the United States raised concerns about the introduction of the virus in the Caribbean region. The objective of this study was to provide rapid evidence of the introduction of EV-D68 strains in the Caribbean region during the 2014 outbreak in the United States, using a relatively simple phylogenetic approach. From October 2014 to May 2015, four EV-D68 cases from two countries (Bermuda and Dominica) were detected at the regional referral laboratory at the Caribbean Public Health Agency (Port of Spain, Trinidad and Tobago) based on molecular testing of respiratory specimens. All cases were children presenting to hospitals with moderate respiratory distress. No cases of acute flaccid paralysis were detected. Phylogenetic analysis of the Caribbean strains showed more than 99% similarity with the 2014 U.S.-outbreak strain, providing evidence of the introduction and circulation of the virus in the region.

RESUMEN El brote de enterovirus D68 (EV-D68) registrado en el 2014 en los Estados Unidos suscitó preocupación acerca de la introducción del virus en el Caribe. El objetivo de este estudio fue aportar pruebas rápidas, mediante la adopción de un enfoque filogénico relativamente sencillo, de que durante ese brote ingresaron en el Caribe cepas del EV-D68. Entre octubre del 2014 y mayo del 2015, el laboratorio regional de referencia ubicado en el Organismo de Salud Pública del Caribe (Puerto España, Trinidad y Tabago) detectó cuatro casos de EV-D68 provenientes de dos países (Bermudas y Dominica) mediante el análisis molecular de muestras respiratorias. Todos los casos correspondían a niños que acudieron al hospital con dificultad respiratoria moderada. No se detectó ningún caso de parálisis flácida aguda. El análisis filogénico de las cepas encontradas en el Caribe demostró una semejanza superior al 99 % con la cepa responsable del brote del 2014 en los Estados Unidos, lo que demuestra la introducción y la circulación del virus en la región.

596 downloads

Creation and pilot testing of cases for case-based learning: A pedagogical approach for pathology cancer diagnosis
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Sayed, Shahin

; Lester, Susan C.

; Wilson, Michael

; Berney, Daniel

; Masia, Ricard

; Moloo, Zahir

; Stall, Jennifer

; Eslan, Alexia

; Ayers, Stephanie

; Mutuku, Angela

; Guarner, Jeannette

African Journal of Laboratory Medicine

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2017, Volume 6 Nº 1 Páginas 1 - 7

Resumo: En | Texto: En | PDF: En

BACKGROUND: Case-based learning (CBL) is an established pedagogical active learning method used in various disciplines and defined based on the field of study and type of case. The utility of CBL for teaching specific aspects of cancer diagnosis to practising pathologists has not been previously studied in sub-Saharan Africa OBJECTIVES: We aimed to pilot test standardised cancer cases on a group of practising pathologists in sub-Saharan Africa to evaluate case content, clarity of questions and delivery of content METHODS: Expert faculty created cases for the four most commonly diagnosed cancers. The format included mini-cases and bullet cases which were all open-ended. The questions dealt with interpretation of clinical information, gross specimen examination, morphologic characteristics of tumours, ancillary testing, reporting and appropriate communication to clinicians RESULTS: Cases on breast, cervical, prostate and colorectal cancers were tested on seven practising pathologists. Each case took an average of 45-90 min to complete Questions that were particularly challenging to testers were on: • Specimens they should have been but for some reason were not exposed to in routine practice. • Ancillary testing and appropriate tumour staging New knowledge gained included tumour grading and assessment of radial margins. Revisions to cases were made based on testers' feedback, which included rewording of questions to reduce ambiguity and adding of tables to clarify concepts. CONCLUSION: Cases were created for CBL in Kenya, but these are applicable elsewhere in Africa and beyond to teach cancer diagnosis. The pilot testing of cases prepared faculty for the actual CBL course and feedback provided by the testers assisted in improving the questions and impact on day-to-day practice

https://doi.org/10.4102/ajlm.v6i1.637 306 downloads

Aggregation study of asphaltenes from colombian Castilla crude oil using molecular simulation
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de León-Barreneche, Jennifer

; Hoyos-Madrigal, Bibian Alonso

; Cañas-Marín, Wilson Antonio

Revista Facultad de Ingeniería Universidad de Antioquia

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Dez 2015, Nº 77 Páginas 25 - 31

Resumo: Es En | Texto: Es En | PDF: Es | PDF: En

Se presenta un modelo de simulación molecular para estudiar el mecanismo de agregación de asfaltenos. Se seleccionaron cuatro especies, obtenidas a partir de análisis estructurales del petróleo extraído del campo Castilla, en Colombia. Se estudiaron las contribuciones energéticas al proceso de agregación y se calculó el parámetro de solubilidad para cada especie. Finalmente, se estudió el proceso de agregación entre las diferentes especies con el fin de determinar la tendencia de las moléculas hacia la autoasociación. Los resultados muestran que para todas las especies, el estado de agregación es energéticamente favorable, y que tanto las fuerzas de Van der Waals como las fuerzas electrostáticas contribuyen en igual magnitud al proceso de agregación. Se encontró también que la estructura molecular de las moléculas tiene una gran influencia en la manera cómo se agregan los asfaltenos. Para las estructuras continentales, las ramificaciones largas ocasionan un impedimento físico para la agregación. Por otro lado, la flexibilidad asociada a las moléculas tipo archipiélago favorece la agregación con otras especies, pero de alguna manera entorpece la autoasociación. El parámetro de solubilidad para todas las especies se encontró dentro del rango establecido por la literatura.

A molecular simulation model to study the mechanism for asphaltene aggregation is presented. Four species were selected, obtained from structural analysis of asphaltenes from the oil extracted from Castilla oil field, in Colombia. Energetic contributions to the aggregation process for each species were studied, and the solubility parameter was evaluated. Finally, the aggregation process between different species was studied in order to determine the tendency of the molecules towards self-association. Results show that for all species, aggregation state is energetically favorable; also, both Van der Waals interactions and electrostatic forces contribute equally to the aggregation process. It was also found that the molecular structure of the substances has a big influence on the manner in which asphaltenes aggregate. For continental structures, long ramifications cause a physical obstacle for aggregation. On the other hand, the molecular flexibility associated with archipelago structures enables the aggregation with other species, but somehow hinders the process of self-association. The solubility parameter for all four substances was within the range established by literature.

https://doi.org/10.17533/udea.redin.n77a04 4117 downloads

10.

Insights of asphaltene aggregation mechanism from molecular dynamics simulation
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De León, Jennifer

; Hoyos, Bibian

; Cañas-Marín, Wilson

DYNA

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Fev 2015, Volume 82 Nº 189 Páginas 39 - 44

Resumo: Es En | Texto: Es En | PDF: Es | PDF: En

Se estudió el proceso de agregación de asfaltenos utilizando técnicas de dinámica molecular. Se utilizaron cuatro estructuras diferentes. Las primeras tres moléculas tienen una estructura continental, con núcleos aromáticos condensador, mientras que la cuarta posee una estructura tipo archipiélago, con pequeños grupos de anillos aromáticos conectados con cadenas saturadas. Las moléculas fueron construidas de manera atomística, en la cual cada átomo se describe individualmente. Se calcularon las fuerzas de interacción a 300 K y 200 atm; las fuerzas de Van der Waals y las interacciones electrostáticas fueron evaluadas separadamente. Se calculó el parámetro de solubilidad para las cuatro moléculas. Se encontró que las interacciones de Van der Waals asociadas a los anillos aromáticos y las fuerzas electrostáticas ocasionadas principalmente por la presencia de heteroátomos como oxígeno, azufre y nitrógeno, son igualmente relevantes en la agregación de moléculas de asfalteno. Para todas las moléculas se encontró que los sistemas de asfaltenos tienen menor energía en estado de agregación que en estado monomérico. Para las estructuras continentales, la presencia de largas cadenas obstruye el proceso de formación de agregados. Para las estructuras tipo archipiélago, la flexibilidad de las moléculas facilita la agregación con otras estructuras. La presencia de heteroátomos ocasiona una fuerza repulsiva que dificulta la agregación. El volumen molecular y la energía de cohesión también son sensibles a la configuración geométrica y la composición de las especies, lo cual afecta el parámetro de solubilidad.

Asphaltene aggregation process was studied using molecular dynamics techniques. Four different structures were used. The first three molecules have a continental structure, with condensed aromatic cores, while the forth has an archipelago structure, with small groups of aromatic rings connected with saturated chains. The molecules were constructed in an atomistic framework, in which atoms are described individually. Interaction forces were calculated at 300 K and 200 atm; Van der Waals and electrostatic interactions were evaluated separately. For all four molecules the solubility parameter was calculated. It was found that Van der Waals interactions due to the presence of aromatic rings and electrostatic forces caused by the presence of heteroatoms such as oxygen, nitrogen and sulfur, are equally relevant in the aggregation of asphaltene molecules. For all molecules it was found asphaltene systems are more stable in aggregation state than in monomeric state. For continental structures, the presence of long ramifications obstructs the formation of asphaltene aggregates. For archipelago structures, the flexibility of the molecules enables the aggregation with other structures. The presence of heteroatoms creates a repulsive force that hinders the aggregation process. The molecular volume and the cohesive energy are also sensitive to the geometric configuration and the composition of the species, which affects the solubility parameter.

https://doi.org/10.15446/dyna.v82n189.41963 3244 downloads

11.

Southern African HIV Clinicians Society adult antiretroviral therapy guidelines: Update on when to initiate antiretroviral therapy
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Meintjes, Graeme

; Black, John

; Conradie, Francesca

; Dlamini, Sipho

; Maartens, Gary

; Manzini, Thandekile C.

; Mathe, Moeketsi

; Moorhouse, Michelle

; Moosa, Yunus

; Nash, Jennifer

; Orrell, Catherine

; Venter, Francois

; Wilson, Douglas

Southern African Journal of HIV Medicine

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2015, Volume 16 Nº 1 Páginas 1 - 4

Resumo: En | Texto: En | PDF: En

The most recent version of the Southern African HIV Clinicians Society's adult antiretroviral therapy (ART) guidelines was published in December 2014. In the 27 August 2015 edition of the New England Journal of Medicine, two seminal randomised controlled trials that addressed the optimal timing of ART in HIV-infected patients with high CD4 counts were published: Strategic timing of antiretroviral therapy (START) and TEMPRANO ANRS 12136 (Early antiretroviral treatment and/or early isoniazid prophylaxis against tuberculosis in HIV-infected adults). The findings of these two trials were consistent: there was significant individual clinical benefit from starting ART immediately in patients with CD4 counts higher than 500 cells/μL rather than deferring until a certain lower CD4 threshold or clinical indication was met. The findings add to prior evidence showing that ART reduces the risk of onward HIV transmission. Therefore, early ART initiation has the public health benefits of potentially reducing both HIV incidence and morbidity. Given this new and important evidence, the Society took the decision to provide a specific update on the section of the adult ART guidelines relating to when ART should be initiated.

https://doi.org/10.4102/sajhivmed.v16i1.428 408 downloads

12.

Reliabilism and Demon World Victims
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Mulnix, Jennifer Wilson

Tópicos (México)

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2013, Nº 44 Páginas 35 - 82

Resumo: En Es | Texto: En Es | PDF: En | PDF: Es

This paper defends reliabilism against the classic demon world victim thought experiment. In doing so, I underscore two of its key alleged intuitions. I then articulate a host of varied responses open to the reliabilist, arguing that these readily available responses provide the reliabilist with a way to either accommodate or reject these initial intuitions about the demon world victim thought experiment, and in a way consistent with reliabilism. Thus, I conclude that the demon world thought experiment does not undercut reliability as the hallmark of epistemic justification.

En este trabajo se defiende el fiabilismo frente al experimento mental clásico del "genio maligno". Al hacerlo, enfatizo dos de sus supuestos clave; y después desarrollo una serie de variadas respuestas asequibles al fiabilista, mostrando que las mismas pueden ser útiles para explicar o negar las intuiciones iniciales de la propuesta del "genio maligno", de una manera consistente con el fiabilismo. Mi conclusión es que el experimento del "genio maligno" no socava la fiabilidad como el sello distintivo de la justificación epistémica.

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13.

Seeing smells: development of an optoelectronic nose
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Suslick, Kenneth S.

; Bailey, Daniel P.

; Ingison, Crystal K.

; Janzen, Michael

; Kosal, Margaret E.

; McNamara III, William B.

; Rakow, Neal A.

; Sen, Avijit

; Weaver, Jeremy J.

; Wilson, Jennifer B.

; Zhang, Chen

; Nakagaki, Shirley

Química Nova

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Jun 2007, Volume 30 Nº 3 Páginas 677 - 681

Resumo: En | Texto: En | PDF: En

The development of an array of chemically-responsive dyes on a porous membrane and in its use as a general sensor for odors and volatile organic compounds (VOCs) is reviewed. These colorimetric sensor arrays (CSA) act as an "optoelectronic nose" by using an array of multiple dyes whose color changes are based on the full range of intermolecular interactions. The CSA is digitally imaged before and after exposure and the resulting difference map provides a digital fingerprint for any VOC or mixture of odorants. The result is an enormous increase in discriminatory power among odorants compared to prior electronic nose technologies. For the detection of biologically important analytes, including amines, carboxylic acids, and thiols, high sensitivities (ppbv) have been demonstrated. The array is essentially non-responsive to changes in humidity due to the hydrophobicity of the dyes and membrane.

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14.

Change in root apical protein and peroxidase activity in response to aluminum in tolerant and sensitive maize inbred lines
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Souza, Isabel Regina Prazeres de

; Alves, Vera Maria Carvalho

; Parentoni, Sidney Netto

; Oliveira, Antônio Carlos de

; Teixeira, Flávia França

; MacAdam, Jennifer Wilson

; Purcino, Antônio Álvaro Corsetii

Brazilian Journal of Plant Physiology

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Set 2002, Volume 14 Nº 3 Páginas 219 - 224

Resumo: Pt En | Texto: Pt En | PDF: Pt | PDF: En

O teor protéico, a expressão e a atividade de isoenzimas da peroxidase foram avaliados em ápices de raiz primária de plântulas de milho expostas a 222 µM de alumínio (Al) por 80 minutos. Duas linhagens com tolerância diferencial ao Al foram utilizadas: Cateto 237 (tolerante) e L36 (sensível). Os 20 mm apicais da raiz primária foi segmentado em intervalos de 2 mm e analisados para teor protéico e atividade da peroxidase. Os resultados demonstraram que o teor protéico ao longo do ápice da raiz da linhagem tolerante não foi afetado pelo Al, mas decresceu na linhagem sensível. O decréscimo na expressão de proteínas, verificado nos 2 mm apicais da raiz da linhagem sensível, foi devido principalmente às proteínas de baixo peso molecular, aproximadamente 43 KDa ou menor. A expressão de quase todas essas mesmas proteínas aumentou na linhagem tolerante, embora o teor protéico total não tenha sido alterado. Isto sugere que algumas destas proteínas possam ter um papel importante na tolerância das plantas aos metais, talvez como peptídeos ligantes. Enquanto a atividade da peroxidase na linhagem tolerante não alterou com a exposição ao Al, esta atividade decresceu ao longo dos 6 mm apicais da raiz na linhagem sensível. Mais isoformas aniônicas foram expressas constitutivamente na linhagem tolerante, mas sem contudo, apresentar alterações qualitativas em reposta ao Al. Os resultados demonstraram que a manutenção da expressão protéica pode ser um componente importante da tolerância das plantas ao Al, e que esta resistência está associada a expressão constitutiva de isoformas aniônicas da peroxidase.

The effects of a short-term (80 min) exposure to 222 µM aluminum (Al) on the protein content and expression and on peroxidase activity and isoenzymes in the primary root of maize were evaluated. Two inbred lines differing in their level of tolerance to Al were used: Cateto 237 (tolerant) and L36 (sensitive). The apical 20 mm of the primary root was divided into 2-mm-long segments that were analyzed for total protein content and peroxidase activity. These results demonstrate that the total protein content along the root apex was not affected by Al in the tolerant inbred line, but decreased in the sensitive line. In the apical 2 mm of the root of the sensitive line, the expression of low molecular weight proteins (43 kDa or smaller) was decreased. Expression of low molecular proteins increased in the tolerant inbred line, even though total protein content did not increase. This suggests that some of these proteins could play a role in metal tolerance, perhaps as binding peptides. While the peroxidase activity of the tolerant inbred line did not change with exposure to Al, peroxidase activity in the apical 6 mm of the root of the sensitive line decreased. The tolerant inbred line constitutively expressed more anionic peroxidase isoforms. These results demonstrate that maintenance of protein expression may be an important component of the plant's resistance to Al stress, and that resistance to Al stress is associated with the higher expression of anionic peroxidase isoforms.

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