3,754 research outputs found

    Uso de nanodiscos de anfotericina B (AMB-NDs) para el tratamiento de enfermedades fúngicas en plantas

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    III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce

    Análisis de la fertilidad potencial del canino (Canis Lupus Familiaris) posterior a la inyección intratesticular de Cloruro de Calcio al 20%

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    Una de las principales técnicas utilizadas para el control de la población canina es la castración. La técnica quirúrgica sin lugar a dudas es la más utilizada y conocida, sin embargo la opción de la castración química ha ido tomando fuerza como una alternativa a la castración quirúrgica, debido a que se considera un proceso no invasivo, económico y de fácil realización, sobre todo en casos de castración masiva de animales como control de la población callejera. En este estudio se utilizó un total de 20 caninos, los cuales se dividieron en: grupos experimentales (1, 2, 3) y grupo control. A los tres grupos experimentales se les aplicó una inyección por vía intratesticular de cloruro de calcio al 20% en ambos testículos, mientras que, al grupo control se le inyectó por la misma vía, solución fisiológica al 0,9%. Previo a esta inoculación todos los pacientes fueron sometidos a un examen físico general, examen andrológico, análisis de fertilidad mediante espermiograma y análisis plasmático de testosterona mediante radio inmuno ensayo (RIA). Al grupo experimental 1 y al grupo control, luego de 7 días post inoculación, se les realizó un nuevo análisis de fertilidad mediante espermiograma y análisis plasmático de testosterona. En el caso del grupo experimental 2 el procedimiento anterior se realizó después de 14 días de la inoculación y el grupo experimental 3, después de 21 días. En relación con el análisis espermático, el grupo experimental 1 no presentó diferencias significativas en ningún parámetro analizado. El grupo experimental 2 presentó diferencias estadísticamente significativas en volumen, concentración espermática y motilidad progresiva. El grupo experimental 3 presentó diferencias estadísticamente significativas en el volumen entre el tiempo inicial y a los 21 días posterior a la inoculación, los parámetros restantes del espermiograma no fueron analizados puesto que no se obtuvo líquido seminal en los pacientes de este grupo, indicando que a los 21 días existiría daño en el tejido testicular evidenciado por la ausencia de espermatogénesis. Los resultados del análisis plasmático de testosterona indicaron que solo en el grupo experimental 3 la concentración de ésta hormona presentó una disminución estadísticamente significativa, por lo cual a partir de los 21 días post-inoculación la concentración de esta hormona comenzaría a descender. Debido a los resultados obtenidos podemos concluir que la utilización de cloruro de calcio al 20% vía intratesticular es una técnica eficaz en lograr la castración, lo que se manifiesta con mayor seguridad a partir de los 21 días post inyección, fácil de realizar y sin efectos adversos, lo que la hace una opción válida, sobre todo en planes de esterilización masiva.  

    Estudio piloto de detenci?n del virus de la rabia en quir?pteros del departamento del Tolima

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    75 p. Recurso Electr?nicoLa rabia es una enfermedad zoon?tica mortal causada por un virus ARN neurotr?pico de la familia Rhabdoviridae. La enfermedad se caracteriza por encefalitis y es responsable de m?ltiples muertes anuales de personas y animales. Los quir?pteros son los principales transmisores, reservorios y vectores del virus. En Colombia, un total de 35 casos de rabia humana fueron reportados entre 2000- 2014 de los cuales 29 se relacionaron a quir?pteros. La enfermedad es transmitida al humano principalmente por gatos infectados que pudieron haber cazado murci?lagos infectados. En el pa?s se ha detectado el virus de la rabia en murci?lagos hemat?fagos y algunos murci?lagos urbanos, sin embargo, en el departamento del Tolima se carece de estudios epidemiol?gicos dirigidos a conocer el estado sanitario de poblaciones de quir?pteros en su h?bitat natural. El diagn?stico de la rabia se realiza mediante la detecci?n del virus principalmente en tejido nervioso, y se ha descrito la t?cnica de RT-PCR, como una herramienta de alta sensibilidad y especificidad para su diagn?stico. Estudios epidemiol?gicos de la rabia, han demostrado que diversas poblaciones de quir?pteros son capaces de actuar como vectores y/o reservorios del virus, por lo cual se ha sugerido la vigilancia activa de las poblaciones de murci?lagos. Este estudio busc? detectar el virus de la rabia en enc?falo de quir?pteros silvestres capturados en algunos municipios del departamento del Tolima a trav?s de la t?cnica de RT-PCR. Dentro del estudio, se realiz? la caracterizaci?n morfom?trica en 12 especies de quir?pteros (n=91). Las muestras analizadas mediante RT-PCR fueron negativas al virus de la rabia. Se concluye que si bien la t?cnica de RT-PCR es efectiva en la detecci?n del virus de la rabia, la cantidad de part?culas virales en tejido de enc?falo de quir?pteros cl?nicamente sanos posiblemente no es suficiente para su detecci?n. Se recomienda ampliar el muestreo de animales y aumentar la cobertura del an?lisis, as? como implementar t?cnicas diagn?sticas complementarias que permitan contrastar los resultados del RT-PCR. Palabras clave: Chiroptera, enfermedad zoon?tica, Rhabdoviridae, variantes gen?ticas.Rabies is a deadly zoonotic disease caused by a neurotropic RNA virus of the Rhabdoviridae family. The disease is characterized by encephalitis and is responsible for multiple annual deaths of animals and people. Chiroptera are the main transmitters, reservoirs and vectors of the virus. In Colombia, a total of 35 cases of human rabies were reported between 2000 and 2014, of which 29 were related to Chiroptera. The disease is transmitted to humans mainly by infected cats that may have hunted infected bats. In the country, the virus has been detected in hematophagous bats and some urban bats, however, in the department of Tolima, there is not epidemiological studies that allow to know the health status of Chiroptera populations in their natural habitat. The diagnosis of rabies is usually made by detecting virus particles in neurological tissues, and the RT-PCR technique is also described as a tool of high sensitivity and specificity for its diagnosis. Epidemiological studies of rabies, have shown that diverse populations of Chiroptera are able to act as vectors and / or reservoirs of the virus, for which active surveillance of bat populations has been suggested. This study sought to detect the rabies virus in encephalon of wild Chiroptera captured in some towns of the department of Tolima through the RT-PCR technique. Within the study, morphometric characterization was performed on 12 bats species (n = 91). The samples analyzed by RT-PCR were negative to rabies virus. Concluding that although the RT-PCR technique is effective in the detection of rabies virus genetic material, the amount of viral particles in brain tissue of clinically healthy bats may not be sufficient for detection. It is recommended to extend the sampling of animals and increase the coverage of the analysis, as well as implement complementary diagnostic techniques that allow contrasting the results of the RT-PCR. Key words: Chiroptera, zoonotic disease, Rhabdoviridae, genetic variants

    The Snail repressor recruits EZH2 to specific genomic sites through the enrollment of the lncRNA HOTAIR in epithelial-to-mesenchymal transition

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    The transcription factor Snail is a master regulator of cellular identity and epithelial-to-mesenchymal transition (EMT) directly repressing a broad repertoire of epithelial genes. How chromatin modifiers instrumental to its activity are recruited to Snail-specific binding sites is unclear. Here we report that the long non-coding RNA (lncRNA) HOTAIR (for HOX Transcript Antisense Intergenic RNA) mediates a physical interaction between Snail and enhancer of zeste homolog 2 (EZH2), an enzymatic subunit of the polycomb-repressive complex 2 and the main writer of chromatin-repressive marks. The Snail-repressive activity, here monitored on genes with a pivotal function in epithelial and hepatic morphogenesis, differentiation and cell-type identity, depends on the formation of a tripartite Snail/HOTAIR/EZH2 complex. These results demonstrate an lncRNA-mediated mechanism by which a transcriptional factor conveys a general chromatin modifier to specific genes, thereby allowing the execution of hepatocyte transdifferentiation; moreover, they highlight HOTAIR as a crucial player in the Snail-mediated EMT.Oncogene advance online publication, 25 July 2016; doi:10.1038/onc.2016.260

    Morphological characteristics of motor neurons do not determine their relative susceptibility to degeneration in a mouse model of severe spinal muscular atrophy

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    Spinal muscular atrophy (SMA) is a leading genetic cause of infant mortality, resulting primarily from the degeneration and loss of lower motor neurons. Studies using mouse models of SMA have revealed widespread heterogeneity in the susceptibility of individual motor neurons to neurodegeneration, but the underlying reasons remain unclear. Data from related motor neuron diseases, such as amyotrophic lateral sclerosis (ALS), suggest that morphological properties of motor neurons may regulate susceptibility: in ALS larger motor units innervating fast-twitch muscles degenerate first. We therefore set out to determine whether intrinsic morphological characteristics of motor neurons influenced their relative vulnerability to SMA. Motor neuron vulnerability was mapped across 10 muscle groups in SMA mice. Neither the position of the muscle in the body, nor the fibre type of the muscle innervated, influenced susceptibility. Morphological properties of vulnerable and disease-resistant motor neurons were then determined from single motor units reconstructed in Thy.1-YFP-H mice. None of the parameters we investigated in healthy young adult mice - including motor unit size, motor unit arbor length, branching patterns, motor endplate size, developmental pruning and numbers of terminal Schwann cells at neuromuscular junctions - correlated with vulnerability. We conclude that morphological characteristics of motor neurons are not a major determinant of disease-susceptibility in SMA, in stark contrast to related forms of motor neuron disease such as ALS. This suggests that subtle molecular differences between motor neurons, or extrinsic factors arising from other cell types, are more likely to determine relative susceptibility in SMA

    Amaranth: distribution and morphological diversity of the genetic resource in parts of the Mayan region (southeast of Mexico, Guatemala and Honduras)

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    Antecedentes y Objetivos: El amaranto es de interés mundial por su valor nutricional como verdura y grano. Las especies cultivadas de mayor importancia comercial por su producción de grano son Amaranthus caudatus, A. cruentus y A. hypochondriacus. Dos hipótesis aceptadas sobre el origen de A. cruentus consideran a A. hybridus como su ancestro. Los objetivos del presente estudio son 1) reportar la distribución actualizada y frecuencia de A. cruentus y A. hybridus en el sureste de México, Guatemala y Honduras y 2) evaluar su diversidad morfológica mediante caracteres florales y del fruto de ambas especies en México y Guatemala.Métodos: La información proveniente de 147 ejemplares de herbario fue empleada para actualizar la distribución y frecuencia de A. cruentus y A. hybridus en la zona de estudio, posible área de domesticación. La diversidad a nivel morfológico se determinó del análisis de 22 caracteres relacionados a estructuras de flores pistiladas y del fruto, usando un análisis multivariado de componentes principales y evaluando para ello 15 ejemplares de A. cruentus y 31 de A. hybridus procedentes de Guatemala y el sureste de México.Resultados clave: La mayor distribución de A. cruentus se presentó en Guatemala y, en el caso de A. hybridus en México. La variación acumulada en los tres primeros componentes principales fue de 58% para ambas especies. La variación morfológica para las dos especies se asoció principalmente con caracteres relacionados a los sépalos internos y externos. El gráfico del análisis de componentes principales permite observar una amplia variación morfológica en A. cruentus y A. hybridus, independiente de su distribución geográfica en ambos casos.Conclusiones: La distribución geográfica de A. cruentus en México es más amplia con respecto a reportes previos. Se describe la diversidad morfológica de estructuras de flores pistiladas y frutos en A. cruentus y A. hybridus.Background and Aims: Amaranth is of worldwide interest for its nutritional value as a vegetable and grain. The principal cultivated species used as grain are Amaranthus caudatus, A. cruentus and A. hypochondriacus. Two accepted hypotheses about the origin of A. cruentus consider A. hybridus as its ancestor. The objectives of this study are 1) to report the updated distribution and frequency of A. cruentus and A. hybridus in southeastern Mexico, Guatemala, and Honduras and 2) to assess their morphological diversity, using floral and fruit characters of both species in Mexico and Guatemala.Methods: The information gathered from 147 herbarium examples was used to update the distribution and determine the frequency of A. cruentus and A. hybridus in the study area, possible area of domestication. Morphological diversity was determined using 22 morphological characters related to pistillate flowers and fruits by conducting a multivariate analysis of main components in a sampling of 15 specimens of A. cruentus and 31 of A. hybridus from Guatemala and southeastern Mexico.Key results: The main distribution of A. cruentus was shown in Guatemala, and of A. hybridus in Mexico. The accumulated variation in the first three principal components was 58% for both species. The morphological variation for both species was mainly associated with characters related to the internal and external sepals. The principal components analysis graph showed wide morphological variation in A. cruentus and A. hybridus regardless of their geographical distribution in both cases.Conclusions: The geographical distribution of A. cruentus in Mexico is wider than previously reported. Diversity was described using morphological characters of pistillate flowers and fruits for A. cruentus and A. hybridus

    Diquat Derivatives: Highly Active, Two-Dimensional Nonlinear Optical Chromophores with Potential Redox Switchability

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    In this article, we present a detailed study of structure−activity relationships in diquaternized 2,2′-bipyridyl (diquat) derivatives. Sixteen new chromophores have been synthesized, with variations in the amino electron donor substituents, π-conjugated bridge, and alkyl diquaternizing unit. Our aim is to combine very large, two-dimensional (2D) quadratic nonlinear optical (NLO) responses with reversible redox chemistry. The chromophores have been characterized as their PF_6^− salts by using various techniques including electronic absorption spectroscopy and cyclic voltammetry. Their visible absorption spectra are dominated by intense π → π^* intramolecular charge-transfer (ICT) bands, and all show two reversible diquat-based reductions. First hyperpolarizabilities β have been measured by using hyper-Rayleigh scattering with an 800 nm laser, and Stark spectroscopy of the ICT bands affords estimated static first hyperpolarizabilities β_0. The directly and indirectly derived β values are large and increase with the extent of π-conjugation and electron donor strength. Extending the quaternizing alkyl linkage always increases the ICT energy and decreases the E_(1/2) values for diquat reduction, but a compensating increase in the ICT intensity prevents significant decreases in Stark-based β_0 responses. Nine single-crystal X-ray structures have also been obtained. Time-dependent density functional theory clarifies the molecular electronic/optical properties, and finite field calculations agree with polarized HRS data in that the NLO responses of the disubstituted species are dominated by ‘off-diagonal’ β_(zyy) components. The most significant findings of these studies are: (i) β_0 values as much as 6 times that of the chromophore in the technologically important material (E)-4′-(dimethylamino)-N-methyl-4-stilbazolium tosylate; (ii) reversible electrochemistry that offers potential for redox-switching of optical properties over multiple states; (iii) strongly 2D NLO responses that may be exploited for novel practical applications; (iv) a new polar material, suitable for bulk NLO behavior

    Evolution of Linear Absorption and Nonlinear Optical Properties in V-Shaped Ruthenium(II)-Based Chromophores

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    In this article, we describe a series of complexes with electron-rich cis-{Ru^(II)(NH_3)_4}^(2+) centers coordinated to two pyridyl ligands bearing N-methyl/arylpyridinium electron-acceptor groups. These V-shaped dipolar species are new, extended members of a class of chromophores first reported by us (Coe, B. J. et al. J. Am. Chem. Soc. 2005, 127, 4845−4859). They have been isolated as their PF_6− salts and characterized by using various techniques including ^1H NMR and electronic absorption spectroscopies and cyclic voltammetry. Reversible Ru^(III/II) waves show that the new complexes are potentially redox-switchable chromophores. Single crystal X-ray structures have been obtained for four complex salts; three of these crystallize noncentrosymmetrically, but with the individual molecular dipoles aligned largely antiparallel. Very large molecular first hyperpolarizabilities β have been determined by using hyper-Rayleigh scattering (HRS) with an 800 nm laser and also via Stark (electroabsorption) spectroscopic studies on the intense, visible d → π^* metal-to-ligand charge-transfer (MLCT) and π → π^* intraligand charge-transfer (ILCT) bands. The latter measurements afford total nonresonant β_0 responses as high as ca. 600 × 10^(−30) esu. These pseudo-C_(2v) chromophores show two substantial components of the β tensor, β_(zzz) and β_(zyy), although the relative significance of these varies with the physical method applied. According to HRS, β_(zzz) dominates in all cases, whereas the Stark analyses indicate that β_(zyy) is dominant in the shorter chromophores, but β_(zzz) and β_(zyy) are similar for the extended species. In contrast, finite field calculations predict that β_(zyy) is always the major component. Time-dependent density functional theory calculations predict increasing ILCT character for the nominally MLCT transitions and accompanying blue-shifts of the visible absorptions, as the ligand π-systems are extended. Such unusual behavior has also been observed with related 1D complexes (Coe, B. J. et al. J. Am. Chem. Soc. 2004, 126, 3880−3891)

    Excitation energy transport with noise and disorder in a model of the selectivity filter of an ion channel

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    A selectivity filter is a gate in ion channels that is responsible for the selection and fast conduction of particular ions across the membrane (with high throughput rates of 108 ions s-1 and a high 1:104 discrimination rate between ions). It is made of four strands as the backbone, and each strand is composed of sequences of five amino acids connected by peptide units H-N-C=O in which the main molecules in the backbone that interact with ions in the filter are carbonyl (C=O) groups that mimic the transient interactions of ion with binding sites during ion conduction. It has been suggested that quantum coherence and possible emergence of resonances in the backbone carbonyl groups may play a role in mediating ion conduction and selectivity in the filter. Here, we investigate the influence of noise and disorder on the efficiency of excitation energy transfer (EET) in a linear harmonic chain of N  =  5 sites with dipole-dipole couplings as a simple model for one P-loop strand of the selectivity filter backbone in biological ion channels. We include noise and disorder inherent in real biological systems by including spatial disorder in the chain, and random noise within a weak coupling quantum master equation approach. Our results show that disorder in the backbone considerably reduces EET, but the addition of noise helps to recover high EET for a wide range of system parameters. Our analysis may help for better understanding of the coordination of ions in the filter as well as the fast and efficient functioning of the selectivity filters in ion channels
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