Organoselenium Compounds as Phytochemicals from the Natural Kingdom.

Selenium is naturally present in soils but it is also produced by pollution from human activities into the environment. Its incorporation into plants affords organoselenium metabolites that, depending on the nature of the molecules and the plant species, can be incorporated into proteins, stored or eliminated by volatilization. The possibility to use the selenium metabolism of some plants as a method for bioremediation and, at the main time, as a source of selenated phytochemicals is here discussed taking into consideration the growing interest in organic selenium derivatives as new potential therapeutic agents

organoselenium compounds an overview on the biological activities beyond antioxidant properties

For a long period, Selenium was considered mainly a toxic element and has been the object of disputes for its controversial balance between beneficial and toxic effects. Nowadays, many evidences demonstrated its role as essential microelement in mammalian diet, having an essential role in redox homeostasis of all the living systems. Around 25 proteins were discovered to contain a selenocysteine in the place of the more common sulfureted amino acid and, in this protein, selenium have the main role in the catalytic center and playng a key role in several major metabolic pathways such as thyroid hormone metabolism, antioxidant defense systems, and immune functions. Many studies report that selenium has a protective effect against some forms of cancer decreases, cardiovascular disease mortality, regulates the inflammatory mediators in asthma, maintains bone homeostasis and protects against bone loss. Antioxidant activities of organoselenium compounds has been widely studied and discussed in a number of recent review article. In this communication taking inspiration from a number of recent publications we want to highlight that other biological activities can be envisioned for organoselenium compounds deriving from the peculiar reactivity of this element

Reaction of Acyl Chlorides with In Situ Formed Zinc Selenolates: Synthesis of Selenoesters versus Ring-Opening Reaction of Tetrahydrofuran

Attempting to apply thein situproduction of PhSeZnSePh to the synthesis of selenoesters, an unexpected reaction involving the solvent (tetrahydrofuran) was observed and studied. We reported here some evidences about the mechanism and the possibility to control the chemoselectivity of this new reaction that afforded the formation of interesting selenoderivatives in which the selenium moiety and the carboxylic one are spaced by four carbon units

highlight on the reactivity of phseznx

The first bench stable selenolates, PhSeZnHalides have been synthesized through a completely atom economy oxidative insertion of the elemental zinc on the commercially available PhSeHalides. These reagents showed the characteristic nucleophilic reactivity which will be reviewed in this report. All of the reactions were strongly accelerated when effected in water suspension. Alkyl, aryl, vinyl and acyl substitutions, ring-opening reactions of epoxides and aziridines and Michael type addition will be described including the role of the zinc in the control of the chemoselectivity and stereoselectivity

Versatilidad del clavo endomedular retrógrado largo de tibia para artrodesis tibio-talo-calcánea en pacientes con lesiones asociadas en el mismo segmento

Introducción: La afección articular que lleva a la necesidad de una artrodesis tibio-calcánea puede estar acompañada de una segunda lesión en el mismo segmento óseo, y los clavos de diseño para artrodesis no tienen la longitud adecuada para cubrir ambas lesiones. No hallamos opciones terapéuticas para este tipo de lesiones en la bibliografía. Objetivo: Presentar una serie de casos en los que se utilizó un único clavo de tibia (de colocación anterógrada) de forma retrógrada, con el doble objetivo de efectuar una artrodesis tibio-talo-calcánea, sumada al tratamiento de una lesión asociada en un mismo tiempo quirúrgico. Materiales y Métodos: Se evaluó, en forma retrospectiva, desde septiembre de 2009 hasta junio de 2019, a un grupo de 12 pacientes que requirió una artrodesis tibio-talo-calcánea sumada a la necesidad de resolver simultáneamente un defecto secundario local. La edad promedio fue de 43.7 años, y el seguimiento global fue de 43.9 meses. Resultados: Todos los pacientes lograron una artrodesis tibio-calcánea constatada en radiografías de frente y de perfil, y el 83,3% recuperó el stock óseo de manera completa. Conclusión: Ante la ausencia en el mercado de osteosíntesis para resolver las patologías asociadas en un mismo paciente, proponemos el uso del clavo endomedular largo de tibia colocado de manera retrógrada como una opción de tratamiento, porque se ha demostrado que es eficaz para lograr la artrodesis tibio-calcánea. Además, se lo pudo utilizar como guía en el alargamiento y el transporte óseo, y como estabilización para tratar lesiones simultáneas

Evidências desfavoráveis para avaliação da personalidade com um instrumento de 10 itens

This study analyzes the internal structure, precision and differences of averages by gender and age on a 10-item scale, designed to assess the Big Five Personality traits. A total of 404 high school students, with an average age of 15.9 years, from São Paulo, Brazil participated in the study. The Ten-Item Personality Inventory (TIPI) scale is comprised of pairs of adjectives representing personality traits arranged on a Likert scale varying from 1 to 7, measuring levels of agreement. It was not possible to identify the five-factor solution through analysis of the main components, but a three-factor structure was found that encompassed the content of social desirability, adjustment problems, and emotional stability, with the alpha varying from 0.41 to 0.63. Additionally, statistically significant differences associated with age were found. Results are discussed in terms of the study and scale limitations.Este estudio tuvo objetivo analizar la estructura interna, precisión y las diferencias de acuerdo con género y edad en una escala de 10 ítems para evaluación de los cinco grandes factores de la personalidad. Participaron 404 estudiantes de la escuela secundaria, con una edad media de 15,9 años, del estado de São Paulo. La escala Ten-Item Personality Inventory (TIPI), conformada por 10 ítems, que son pares de adjetivos que representan los rasgos de la personalidad bajo en una escala tipo Likert de 1 a 7. No fue posible recuperar la estructura de cinco factores a través del análisis de componentes principales, pero sí una estructura de tres factores que abarca el contenido de la deseabilidad social, problemas de ajuste y la estabilidad emocional, con la precisión entre 0,41 y 0,63. Además, fueron encontradas diferencias de medias significativas asociadas con la edad. Los resultados se discuten en relación a las limitaciones del estudio y escala.Este estudo objetivou analisar a estrutura interna, a precisão e as diferenças de média por sexo e idade em uma escala de 10 itens para avaliação dos Cinco Grandes Fatores de Personalidade. Participaram 404 estudantes do ensino médio, com média de idade de 15,9 anos, do Estado de São Paulo. A escala Ten-Item Personality Inventory (TIPI) é composta por 10 itens, que são duplas de adjetivos e que representam os traços de personalidade respondidos em escala Likert de 1 a 7. Não foi possível recuperar a estrutura de cinco fatores por meio da análise dos componentes principais, mas sim uma estrutura de três fatores que englobaram conteúdos de desejabilidade social, problemas de ajustamento e estabilidade emocional, com precisões entre 0,41 e 0,63. Além disso, houve diferenças significativas de média associadas à idade. Os resultados são discutidos em termos das limitações do estudo bem como da escala utilizada

ultrasound mediated synthesis of ecofriendly zinc chalcogenates in on water conditions

Nucleophilic Selenium is a convenient strategy for the functionalization of organic substrates having electrophilic character. Among all the methods developed for their preparation, the reduction of the corresponding diselenides represents the most versatile procedure. Using these protocols selenolates were usually prepared in situ using atom expensive reducing agents such as NaBH4, LiAlH4, or metals (Na, Li) or metal hydride (NaH). We recently reported that zinc can be efficiently used to reduce Se-halogen bond affording bench stable regents such as PhSeZnCl that showed a strong rate acceleration in "on water" conditions for a number of reactions: alkyl, aryl, vinyl and acyl substitutions, ring-opening reactions of epoxides and aziridines and Michael type addition. We report now the use of Ultrasound irradiation for the oxidative insertion of zinc into Se-Se bond and the formation of the nucleophilic reagent PhSeZnSePh as a green strategy to avoid the use of useless halogen and increase the atom economy of the selenenylating species

Diálogos sobre la experiencia virtual durante la pandemia y sus consecuencias en un posible escenario de postpandemia

The aim of this paper is to establish dialogue between the teacher assistants of History of the Spanish Language and their professor about the online classroom in the context of the global pandemic. The work is based on “The Ignorant Schoolmaster” by the French philosopher Jacques Rancière (Le maître ignorant, Paris, Fayard, 1987) breaking with classical teaching based on the idea that a subject (the teacher) possesses knowledge that is transmitted through an explanation to another subject (the student) who does not have it, since this reproduces inequalities inherent to the social relations of capitalist production. Thus, if one of the fundamental missions of the public university is to achieve social equality through access to the development of critical thinking, we consider that horizontal, plural, and transversal dialogue between students and teachers is essential to reflect on the most critical periods, in an attempt to improve equal opportunities. In this way, reflections on students’experiences during the first period of the online classrooms are highlighted, which served as a basis for reformulating the dynamics of a History of the Spanish Language course in 2020.En el presente trabajo, proponemos el formato de diálogo entre lxs estudiantes adscriptxs de la cátedra de Historia de la Lengua (Letras) con su directora para reflexionar sobre el trabajo en equipo realizado durante la cursada virtual en el contexto de pandemia. Se parte de la premisa básica del “maestro ignorante” propuesta por el filósofo francés Jacques Rancière (Le maître ignorant, París, Fayard, 1987), que rompe con la enseñanza clásica basada en la idea de que un sujeto –el maestro– posee un conocimiento que es transmitido mediante una explicación a otro sujeto –el alumno– que no lo tiene, reproduciendo de algún modo las desigualdades propias de las relaciones sociales de producción capitalista. Así, si una de las misiones fundamentales de la universidad pública es lograr la igualdad social a través del acceso al desarrollo del pensamiento crítico, consideramos que el diálogo horizontal, plural y transversal a la vez entre estudiantes y docentes es fundamental para reflexionar sobre los periodos más críticos, en un intento de mejorar la igualdad de oportunidades. De este modo, se ponen de manifiesto reflexiones sobre experiencias de lxs estudiantes vividas durante el primer cuatrimestre de cursada virtual que sirvieron de base para reformular la dinámica de una comisión de trabajos prácticos de Historia de la Lengua en el segundo cuatrimestre de 2020

Técnicas de higiene oral en odontología preventiva y social

Las técnicas de higiene oral tienen como objetivo la salud buco-dental, es decir el cuidado de los dientes, encías y boca. Un cepillado diario y correcto es imprescindible para prevenir las enfermedades más frecuentes causadas por la placa: caries y enfermedad periodontal. Como estudiantes de odontología nos corresponde difundir y facilitar a las personas dicha información, contando las ventajas, motivando, mostrando las técnicas más frecuentes y útiles. Promoviendo a que los adultos se instruyan e incorporen dichas medidas de higiene con la entrega de folletos con datos objetivos y muestras de la práctica.Categoría: Casos clínicos.Facultad de Odontologí