Deshidratación de alcoholes bencílicos promovida por ioduro de ciclohexano

Las reacciones de eliminación son sin duda métodos más accesibles y ampliamente utilizados para la obtención de alquenos, estas proceden ya sea en condiciones ácidas o básicas en donde los sustratos de partida contienen grupos salientes como Br, I, OMs, OTs, y donde a menudo se requiere de bases y/o ácidos fuertes. En este contexto, en las reacciones de deshidratación catalizadas por medio ácido regularmente requieren de altas temperaturas y la utilización de ácidos fuertes lo que conducen a la obtención de los productos deseados, pero en bajos rendimientos y la obtención de productos indeseados. En este trabajo se reporta un nuevo método para la obtención de una serie de olefinas bencílicas a partir de un conjunto de alcoholes bencílicos, mediada por la lenta liberación de un ácido fuerte el HI (pKa=-9.5) siendo la fuente de este el ioduro de ciclohexano y como reacción paralela y esperada la desmetilación de un éter bencílico.The reactions of eliminations are undoubtedly the most accessible and widely used methods for obtaining alkenes, they proceed either under acidic or basic conditions where the starting substrates contain leaving groups such as Br, I, OMs, OTs, end where often strong bases/ or acid are required. In this context acid catalyzed dehydration reactions regularly require high temperatures and the used of strong acid, which lead to obtaining desired products but in low yields and obtaining of undesired products. In this work, we report a new method for obtaining of a series the benzylic olefines from a set of benzylic alcohols by slow release of a strong acid HI (pka= -9.5), the source of which is cyclohexane iodide and as a parallel end expected reaction demethylation of an ether benzylic

Adsorción de dióxido de carbono en redes metal orgánicas de terbio

Los materiales tipo MOF (metal organic frameworks) tienen características fisicoquímicas modulables y son capaces de adsorber el CO₂, actúan como una especie de esponjas a escala molecular, cuyo tamaño de poros se define de acuerdo con las necesidades, permitiéndole tener una excelente capacidad de adsorber compuestos líquidos y gases, retenerlos en su interior, y poder realizar modificaciones una vez sintetizados. En este trabajo, se presentan los resultados de la adsorción de CO₂ en MOF de terbio sintetizadas con los ligandos orgánicos: 1,4-bencenodicarboxilato (BDC), benceno-tricarboxilato (BTC) y 1,3-tiofeno-dicarboxilato (TDC). Los materiales obtenidos se caracterizaron mediante DRX, FT-IR, TGA, MEB, EDX y adsorción de N₂. Con el análisis estructural se determinó el tamaño nanométrico de los materiales cristalinos. La capacidad de adsorción de CO₂ se modificó con el tratamiento térmico de las muestras bajando de 17.6 a 7.5 cm³/g para Tb₂(BDC)₃, de 112 a 12.6 cm3/g para Tb(BTC) y en el caso de Tb₂(TDC)₃ con una menor decaída de 15.9 a 14.6 cm³/g.MOF (metal organic frameworks) type materials have modulable physicochemical characteristics and are capable of adsorbing CO₂, they act as a kind of sponges on a molecular scale, whose pore size is defined according to needs, allowing it to have an excellent adsorption capacity. liquid compounds and gases, retain them inside, and be able to make modifications once synthesized. In this work, the results of CO₂ adsorption in terbium MOFs synthesized with the organic ligands: 1,4- benzenedicarboxylate (BDC), benzene-tricarboxylate (BTC) and 1,3-thiophenedicarboxylate (TDC) are presented. The materials obtained were characterized by XRD, FT-IR, TGA, SEM, EDX and N₂ adsorption. With the structural analysis, the nanometric size of the crystalline materials was determined. The CO₂ adsorption capacity was modified with the heat treatment of the samples, decreasing from 17.6 to 7.5 cm³/g for Tb₂(BDC)₃, from 112 to 12.6 cm3/g for Tb(BTC) and in the case of Tb₂(TDC )₃ with a smaller decay of 15.9 to 14.6 cm³/g

Implementation of stubble in agricultural production: A review

Objective: Elucidate the benefits that agricultural residues or stubble have in agricultural activities, this through a bibliographic and objective review that helps to make the actors of agricultural sector aware of the benefits and their correct implementation in production systems. Design/methodology/approach: Detailed review of scientific articles from the main academic databases and repositories. Taking into account aspects such as the use of stubble as plant cover; effects and changes in physical and chemical structure of soil; crop yield and use for livestock feeding. Results: The use of stubble has beneficial effects on agricultural activities. In agriculture it is proven that they have positive effects for the proliferation of beneficial organisms and assimilation of nutrients, which are easily absorbed by plants, consequently, crop yield is maximized in quantity and quality. In livestock sector, the stubble implement provides nutrients such as proteins, ashes and vitamins, which together with conventional diets, reduce production costs and improve meat and milk production. Limitations on study/implications: The repertoire of scientific articles of stubble is very broad, making it difficult to assimilate the information. In Mexico, particularly, more research is needed to inform farmers of the possible uses of stubble. Findings/conclusions: The use of stubble in agricultural activities generates benefits at ecological and economic levels, which ensure the sustainability and resilience of agroecosystems. Nutritional content of stubble is a function of the species and/or varieties of agricultural species. The lack of knowledge in the management of stubble leads to these being incinerated, releasing particles and toxic and polluting substances for the environment, further favoring the conditions for greenhouse effect. Keywords: stubble, vegetation cover, yield, sustainability, resilience.Objective: To elucidate the benefits that agricultural residues or stubble have in agricultural activities, through a bibliographic and objective review that could help to make the actors of agricultural sector aware of the benefits and their correct implementation in production systems. Design/methodology/approach: A detailed review of scientific articles from the main academic databases and repositories was performed. We took into account aspects such as the use of stubble as plant cover; effects and changes in physical and chemical structure of soil; crop yield and use for livestock feeding. Results: The use of stubble has beneficial effects on agricultural activities. In agriculture, they have positive effects for the proliferation of beneficial organisms and assimilation of nutrients, which are easily absorbed by plants. Consequently, crop yield is maximized both in quantity and quality terms. In livestock sector, the stubble implement provides nutrients such as proteins, ashes and vitamins, which together with conventional diets, reduce production costs and improve meat and milk production. Limitations on study/implications: The repertoire of scientific articles related to stubble is very broad, making it difficult to assimilate the information. In Mexico, particularly, more research is needed to inform farmers of the possible uses of stubble. Findings/conclusions: The use of stubble in agricultural activities generates benefits at ecological and economic levels, which ensure the sustainability and resilience of agroecosystems. Nutritional content of stubble is a function of the species and/or varieties of agricultural species. The lack of knowledge in the management of stubble leads to these being incinerated, releasing particles and toxic and polluting substances for the environment, further favoring the conditions for greenhouse effect

Potential distribution models of Sechium tacaco (Pittier) C. Jeffrey in Costa Rica

Objective: To determine the current and potential distribution of S. tacaco in Costa Rica with seven machine learning models, to optimize the management of phytogenic resources of S. tacaco, aimed at identifying patterns of geographic distribution and possible climatic adaptations that allow to have perspectives on their conservation and breeding. Design/Methodology/Approach: 21 occurrence records together with 19 bioclimatic variables and the altitude variable were used to evaluate seven machine learning models and an assembly of them. Open-source libraries executed in Rstudio were used. Results: The distribution models were inferred by the variables bio1, bio2, bio3, bio4, bio12, bio13, bio14, bio18 and bio19. The GAM model obtained the highest AUC (0.96) and TSS (0.9) values, however, the seven evaluated models and the assembly showed adequate performance (AUC> 0.5 and TSS> 0.4). The bioclimatic variables related to temperature turned out to be the ones with the greatest contribution to the models and the main limitations in the distribution of S. tacaco. Limitations/Implications: A greater number of occurrence records may be required to evaluate distribution models. Conclusions: The areas with high suitability for the potential distribution of S. tacaco are found in the central valleys of Costa Rica, covering regions of the provinces of Alajuela, Cartago, San José and Puntarenas. These can be sources of germplasm for future conservation and breeding studies. Keywords: Machine learning, germplasm, conservation, breeding.Objective: Determine current and potential distribution of S. tacaco in Costa Rica with seven Species Distribution Models (SDM), in order to optimize the management of S. tacaco genetic resources, aimed at identifying patterns of geographic distribution and possible climatic adaptations allowing to have perspectives on their conservation and genetic breeding. Design/Methodology/Approach: 21 points of occurrence together with 19 bioclimatic variables and altitude were used to evaluate seven machine learning models and an assembly of these. Open-source libraries running in Rstudio were used. Results: Distribution models were inferred by the variables bio1, bio2, bio3, bio4, bio12, bio13, bio14, bio18 y bio19. The generalized additive model obtained the highest values ??of area under the curve (0.96) and True skill statistic (0.90), however, the seven models tested and the assembly showed adequate performance (AUC> 0.5 and TSS> 0.4). Bioclimatic variables related to temperature were the ones with the greatest contribution to the models and the main limitations in the distribution of S. tacaco. Study limitations/implications: Possibly a greater number of occurrence points are required to evaluate distribution models. Findings/Conclusions. Areas with high potential distribution suitability for S. tacaco are found in central valleys of Costa Rica, covering regions of the provinces of Alajuela, Cartago, San José and Puntarenas. These areas can be sources of germplasm for future conservation and breeding studies

Abandono precoz de la lactancia materna exclusiva en menores de 1 año

Introduction: the virtues of breast milk as the only food in children up to 6 months have been universally studied because the viral antibodies present in breast milk have action against: rotavirus, which is the most common causal agent of diarrhea, polyvirus, causal agents of polio, respiratory syncytial virus (RSV) main causative agent of infant bronchiolitis.Objective: identify causes related to the abandonment of exclusive breastfeeding in children under one year of age in a polyclinic in Manzanillo.Methodology: An observational, descriptive and retrospective study was carried out, with 30 children under one year of age born in the first four months of 2019 at the Manzanillo Polyclinic No. 1. The main variables were: type of breastfeeding received up to 6 months, causes for abandoning exclusive breastfeeding, some maternal risk factors, and some illnesses they suffered. Descriptive statistics were used for data processing.Results: artificial lactation (33.3%) predominated as a form of feeding and exclusive breastfeeding (56.6%) in the first semester of life, the most frequent causes for early abandonment were hypogalactia (53.9) and distrust in its effectiveness (23.1%). Maternal age (38.5%) and occupation (84.6%) were the maternal factors that were most related to the early abandonment of exclusive breastfeeding and the presence of respiratory diseases (61.5%).Conclusions: Infants weaned early had a greater presence of diseases than those adequately breastfed, which ensures that breastfeeding, provides innumerable health benefits. The causes of abandonment were related to subjective aspects of the mother.Introducción: las virtudes de la leche materna como único alimento en el niño hasta los 6 meses han sido universalmente estudiadas porque los anticuerpos virales presentes en la leche materna tienen acción contra: rotavirus que es el agente causal más común de diarreas, polivirus agentes causales de la poliomielitis, virus sincitial respiratorio (VSR) principal agente causal del bronquiolitis del lactante.Objetivo: identificar causas relacionadas con el abandono de la lactancia materna exclusiva en niños menores de un año en un policlínico de Manzanillo.Método: se realizó un estudio observacional, descriptivo y retrospectivo, con 30 niños menores de un año nacidos en el primer cuatrimestre del año 2019 del Policlínico No.1 de Manzanillo. Las variables principales fueron: tipo de lactancia recibida hasta los 6 meses, causas para el abandono de la lactancia materna exclusiva, algunos factores de riesgo maternos, algunas enfermedades que padecieron. Se empleó la estadística descriptiva para el procesamiento de datos.Resultados: predominó la lactancia artificial (33,3%) como forma de alimentación y la lactancia exclusiva (56,6%) en el primer semestre de la vida, las causas más frecuentes para el abandono precoz fueron la hipogalactia (53,9) y la desconfianza en la efectividad de la misma (23,1%). La edad materna (38,5%) y la ocupación (84,6%) fueron los factores maternos que más se relacionaron con el abandono temprano de la lactancia materna exclusiva y la presencia de enfermedades respiratorias (61,5%).Conclusión: los lactantes destetados precozmente presentaron mayor presencia de enfermedades que los adecuadamente amamantados, lo que asegura que la lactancia materna proporciona innumerables ventajas para la salud. Las causas del abandono se relacionaban con aspectos subjetivos de la madre

LA U INVESTIGA: Revista Científica. Facultad Ciencias de la Salud. Volumen 3. Número 2

En el presente volumen se distinguen varios ámbitos de la investigación en salud desde artículos asociados a la promoción de salud, prevención de enfermedades, así como investigaciones de casos clínicos que evidencia la experiencia del equipo de salud en patologías específicas. Hay que resaltar que muchos de los artículos presentados en el volumen actual corresponden a los resultados de investigaciones ejecutadas en la academia, propias de la Universidad Técnica del Norte y de otras.1._ Melanoma antebraquial derecho metastásico a pa¬red abdominal y pelvis presentación de un caso clínico. 2._ Carcinoma papilar de localizacion extratiroidea. 3._ Tumores del golfo de la yugular 4._ Estudio comparativo del desarrollo psicomotor en niños/as de 1 a 3 años del Centro Infantil del Buen Vivir “CENTRO PUCARA” y “GOTITAS DE AMOR” del cantón Antonio Ante de la provincia de Imbabura. 5._ Adaptaciones de las técnicas comunicacionales al proceso terapéutico de salud mental infantil. 6._ La dinámica de la investigación científica en la formación de los profesionales de enfermería: una aproximación al problema de investigación. 7._ Las agresiones en las parejas de enamorados en la adolescencia y el equilibrio emocional. 8._ Rasgos de personalidad y su influencia en la calidad de vida en los estudiantes de la Unidad Educativa” Las Américas” 9._ Estudio de la postura corporal y su relación con la obesidad y sobrepeso en niños de 6 a 12 años del cantón Antonio Ante de la provincia de Imbabura. 10._ Caracterización de cuidadores informales de personas con discapacidad de la provincia de Im¬babura. 11._ Intervención educativa sobre embarazo en la adolescencia en estudiantes del tercer año de bachillerato de la unidad educativa “Madre Tere¬sa Bacq” Imbabura-Ecuador. 12._ Acceso a la atención de consulta externa de los usuarios del centro de llamadas, que asisten al subcentro de salud San Antonio, Tanguarin Iba¬rra, ecuador 2016. 13._ Prevalencia de disfunción familiar en la parro¬quia urbana de Urcuquí

Enfrentando los riesgos socionaturales

El objetivo del libro es comprender la magnitud de los Riesgos Socionaturales en México y Latinoamérica, para comprender el peligro que existe por algún tipo de desastre, ya sea inundaciones, sismos, remoción en masa, entre otros, además conocer qué medidas preventivas, correctivas y de contingencias existen para estar atentos ante alguna señal que la naturaleza esté enviando y así evitar alguna catástrofe. El libro se enfoca en los aspectos básicos de análisis de los peligros, escenarios de riesgo, vulnerabilidad y resiliencia, importantes para la gestión prospectiva o preventiva

Clinical and Immunological Factors That Distinguish COVID-19 From Pandemic Influenza A(H1N1).

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), is a global health threat with the potential to cause severe disease manifestations in the lungs. Although COVID-19 has been extensively characterized clinically, the factors distinguishing SARS-CoV-2 from other respiratory viruses are unknown. Here, we compared the clinical, histopathological, and immunological characteristics of patients with COVID-19 and pandemic influenza A(H1N1). We observed a higher frequency of respiratory symptoms, increased tissue injury markers, and a histological pattern of alveolar pneumonia in pandemic influenza A(H1N1) patients. Conversely, dry cough, gastrointestinal symptoms and interstitial lung pathology were observed in COVID-19 cases. Pandemic influenza A(H1N1) was characterized by higher levels of IL-1RA, TNF-α, CCL3, G-CSF, APRIL, sTNF-R1, sTNF-R2, sCD30, and sCD163. Meanwhile, COVID-19 displayed an immune profile distinguished by increased Th1 (IL-12, IFN-γ) and Th2 (IL-4, IL-5, IL-10, IL-13) cytokine levels, along with IL-1β, IL-6, CCL11, VEGF, TWEAK, TSLP, MMP-1, and MMP-3. Our data suggest that SARS-CoV-2 induces a dysbalanced polyfunctional inflammatory response that is different from the immune response against pandemic influenza A(H1N1). Furthermore, we demonstrated the diagnostic potential of some clinical and immune factors to differentiate both diseases. These findings might be relevant for the ongoing and future influenza seasons in the Northern Hemisphere, which are historically unique due to their convergence with the COVID-19 pandemic

A Coffee Berry Borer (Coleoptera: Curculionidae: Scolytinae) Bibliography

Native to Africa, the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae: Scolytinae), has gradually invaded most coffee-growing areas worldwide. Adult females colonize the coffee berry and oviposit within galleries in the coffee seeds. Larvae and adults consume the seeds, resulting in drastic reductions in yields and quality, negatively affecting the income of approximately 20 million coffee-growing families (~100 million people) in ~80 countries, with losses surpassing more than $500 million annually (Vega et al. 2015). It has become evident that the coffee berry borer scientific community could greatly benefit from having access to a bibliography of the literature related to the insect. Such an information source would allow scientists to find out what research areas have been explored throughout the many coffee berry borer-infested countries after more than 100 years of research on the topic. It could also help to direct lead future research efforts into novel areas, and away from topics and ideas that have been thoroughly investigated in the past