Control de acceso con verificación de identidad por medio de código de barras

Ingeniero (a) ElectrónicoPregrad

Hacia una definición de la física (1)

"Podemos, en resumen, caraterizar la Física como "una ciencia de la razón que estudia la naturaleza desde un punto de vista cuantitativo, por medio de magnitudes que la ordenan, signos que representan esas magnitudes, unidades que las miden y leyes empíricas que las relacionan matemáticamente entre sí".Bogotá, marzo 194

Estudio de bioprospección de octocorales de los géneros eunicea y plexaura del caribe colombiano, como fuente de metabolitos con actividad antiinflamatoria

La evaluación de la actividad antiinflamatoria in vivo, mediante el ensayo de edema auricular inducido por TPA, de los extractos de ocho especies de octocorales pertenecientes al género Eunicea y dos pertenecientes al género Plexaura recolectadas en el Caribe Colombiano, permitió identificar a los extractos de E. fusca y P. hamo malla como fuente de compuestos antiinflamatorios por su alta actividad en dicho ensayo. A partir del estudio químico de E. fusca se logró obtener un nuevo compuesto denominado fuscósido E, junto con el fuscósido B, el fuscol, el (+)-germacreno D y una mezcla de cuatro esteroles. Del extracto de P. homomalla se aislaron las prostaglandinas (15R)-PGA" (15R)-PGA, Me, (15R)-Ac PGA" (15R)-Ac PGA, Me y (15R)-PGE. La elucidación estructural de estos compuestos se llevó a cabo por estudios de RMN 1D Y 2D. La configuración absoluta de todos los compuestos aislados fue determinada mediante métodos quiroópticos y derivatización química. Los fuscósido E y B, junto con las (15R)-PGA, y (15R)-PGE, presentaron, respectivamente, la mayor inhibición de la inflamación la cual fue comparable con la presentada por la indometacina, fármaco de referencia usado como control positivo, en el ensayo inicialmente mencionado. / Abstract. The screening for in vivo anti-inflammatory activity, by testing in the TPA-induced ear edema model, of the extracts of eight octocoral species belonging to the genus Eunicea and two belonging to Plexaura genus collected from the Colombian Caribbean Sea resulted in the identification of E. fusca and P. homomalla extracts as a source of inflammatory compounds by its high activity in this test. From the chemical study of E. fusca a new compound named fuscoside E, together with fuscoside B, fuscol, (+)-germacrene D and a mixture of four sterols were isolated. From the extract of P. homomalla the prostaglandins (15R)-PGA" (15R)-PGA, Me, (15R)-Ac PGA" (15R)-Ac PGA, Me and (15R)-PGE, were isolated. The structural elucidation of these compounds was carried out by iD and 2D NMR analysis. The absolute configuration of all isolated compounds was determined by quiroptical methods and chemical derivatization. The fuscoside E and B, together with (15R)-PGA, and (15R)-PGE, showed, respectively, the stronger activity as inhibitors of the inflammation, comparable with that of the indomethacin, a drug used as reference and positive control in the above mentioned bioassay.Maestrí

Proteólisis cerebral del péptido amiloide-ß: Relevancia de la enzima degradadora de insulina en la enfermedad de Alzheimer

El aumento global de la expectativa de vida convierte a la enfermedad de Alzheimer (EA) en un problema creciente. Una de las características distintivas de EA es la acumulación excesiva del péptido amiloide ß (Aß) en el cerebro. En los últimos años se ha fortalecido el concepto de que la degradación de Aß por proteasas in situ es un mecanismo importante que previene su acumulación cerebral. Datos bioquímicos y genéticos mostraron que la enzima degradadora de insulina (IDE) participa en la homeostasis de Aß e insulina. La expresión y la actividad de IDE están significativamente disminuidas en cerebros con EA comparados con controles de igual edad. Además, IDE se deposita con Aß en placas seniles y vasos, indicando un grosero cambio conformacional producto de distintos mecanismos post-traduccionales. Estas alteraciones en la distribución y actividad de IDE resultan en una insuficiente degradación de Aß e insulina y promueven la formación de oligómeros de Aß y la resistencia a la hormona, procesos que convergen hacia la neurodegeneración. El estudio de los mecanismos de eliminación de Aß cerebral no sólo ayudará a comprender la patogenia de EA sino que permitirá una mejor interpretación de los ensayos clínicos en curso y el desarrollo de nuevas estrategias terapéuticas.Cerebral proteolysis of amyloid- peptide: Relevance of insulin-degrading enzyme in Alzheimer’s disease. The global increase in life expectancy turns Alzheimer’s disease (AD) into a growing problem. One of the distinctive features of AD is the excessive accumulation of amyloid- (A) peptide in the brain. In recent years, a concept that has gained strength is that degradation of A by proteases in situ is an important mechanism that prevents cerebral peptide accumulation. Biochemical and genetic data have shown that insulin-degrading enzyme (IDE) participates in A and insulin homeostasis. IDE expression and activity are significantly decreased in AD brains compared to age-matched controls. Also, IDE is deposited with A in senile plaques and blood vessels, indicating a gross conformational change as a consequence of diverse post-translational mechanisms. These alterations in IDE distribution and activity may result in insufficient degradation of A and insulin, promoting the formation of A oligomers and hormone resistance. Both processes might play a fundamental part in neurodegeneration. The study of the clearance mechanisms of cerebral A will not only aid in the understanding AD pathogenesis but will also allow a better interpretation of ongoing clinical trials and the development of new therapeutic strategies.Fil: Leal, Maria Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Fernandez Gamba, Agata Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Morelli, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Castaño, Eduardo Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

Co-designing climate-smart farming systems with local stakeholders: A methodological framework for achieving large-scale change

The literature is increasing on how to prioritize climate-smart options with stakeholders but relatively few examples exist on how to co-design climate-smart farming systems with them, in particular with smallholder farmers. This article presents a methodological framework to co-design climate-smart farming systems with local stakeholders (farmers, scientists, NGOs) so that large-scale change can be achieved. This framework is based on the lessons learned during a research project conducted in Honduras and Colombia from 2015 to 2017. Seven phases are suggested to engage a process of co-conception of climate-smart farming systems that might enable implementation at scale: (1) “exploration of the initial situation,” which identifies local stakeholders potentially interested in being involved in the process, existing farming systems, and specific constraints to the implementation of climate-smart agriculture (CSA); (2) “co-definition of an innovation platform,” which defines the structure and the rules of functioning for a platform favoring the involvement of local stakeholders in the process; (3) “shared diagnosis,” which defines the main challenges to be solved by the innovation platform; (4) “identification and ex ante assessment of new farming systems,” which assess the potential performances of solutions prioritized by the members of the innovation platform under CSA pillars; (5) “experimentation,” which tests the prioritized solutions on-farm; (6) “assessment of the co-design process of climate-smart farming systems,” which validates the ability of the process to reach its initial objectives, particularly in terms of new farming systems but also in terms of capacity building; and (7) “definition of strategies for scaling up/out,” which addresses the scaling of the co-design process. For each phase, specific tools or methodologies are used: focus groups, social network analysis, theory of change, life-cycle assessment, and on-farm experiments. Each phase is illustrated with results obtained in Colombia or Honduras

Are torque values of preadjusted brackets precise?

OBJECTIVE: The aim of the present study was to verify the torque precision of metallic brackets with MBT prescription using the canine brackets as the representative sample of six commercial brands. MATERIAL AND METHODS: Twenty maxillary and 20 mandibular canine brackets of one of the following commercial brands were selected: 3M Unitek, Abzil, American Orthodontics, TP Orthodontics, Morelli and Ortho Organizers. The torque angle, established by reference points and lines, was measured by an operator using an optical microscope coupled to a computer. The values were compared to those established by the MBT prescription. RESULTS: The results showed that for the maxillary canine brackets, only the Morelli torque (-3.33º) presented statistically significant difference from the proposed values (-7º). For the mandibular canines, American Orthodontics (-6.34º) and Ortho Organizers (-6.25º) presented statistically significant differences from the standards (-6º). Comparing the brands, Morelli presented statistically significant differences in comparison with all the other brands for maxillary canine brackets. For the mandibular canine brackets, there was no statistically significant difference between the brands. CONCLUSIONS: There are significant variations in torque values of some of the brackets assessed, which would clinically compromise the buccolingual positioning of the tooth at the end of orthodontic treatment

Cone-Beam Computed Tomography and Radiographs in Dentistry: Aspects Related to Radiation Dose

Introduction. The aim of this study was to discuss the radiation doses associated with plain radiographs, cone-beam computed tomography (CBCT), and conventional computed tomography (CT) in dentistry, with a special focus on orthodontics. Methods. A systematic search for articles was realized by MEDLINE from 1997–March 2011. Results. Twenty-seven articles met the established criteria. The data of these papers were grouped in a table and discussed. Conclusions. Increases in kV, mA, exposure time, and field of view (FOV) increase the radiation dose. The dose for CT is greater than other modalities. When the full-mouth series (FMX) is performed with round collimation, the orthodontic radiographs transmit higher dose than most of the large FOV CBCT, but it can be reduced if used rectangular collimation, showing lower effective dose than large FOV CBCT. Despite the image quality, the CBCT does not replace the FMX. In addition to the radiation dose, image quality and diagnostic needs should be strongly taken into account

Síntese de intermediários quirais para obtenção de aminoálcoois em cadeias flexíveis ligadas a um sistema tricíclico

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