Label-free wavelength and phase detection based SMS fiber immunosensors optimized with cladding etching

The performance of E-SMS (Etched Singlemode-Multimode-Singlemode) optical fiber structures as immunosensors has been assessed by the implementation of antibody/antigen immunoassays. Through this procedure it has been proven that E-SMS structures are effective and suitable optical platforms for label-free biosensing. Using the phase shift and tracking the wavelength response it was found that the fabricated E-SMS devices exhibited limits of detection (LOD) down up to concentrations of 0.2 mg/L of antigens in solution. This was achieved by coating the E-SMS with an antibody-based biolayer (goat IgG) that is able to determine the presence of anti-goat IgG antigen. Both a wavelength detection and a fast Fourier transform (FFT) analysis technique were used to perform this analysis. The FFT method showed similar results to those observed with the most traditional wavelength analysis, but with the advantage of a simpler detection system that makes unnecessary the use of sophisticated optical interrogators

Etched and Nanocoated SMS Fiber Sensor for Detection of Salinity Concentration

An optical fibre refractometer has been developed by etching and deposition of a thin film of indium tin oxide (ITO) on a single-mode-multimode-single-mode (SMS) fibre structure. The interference between modes in this structure is sensitive to the refractive index changes of the surrounding medium, achieving sensitivities of up to 7000 nm/RIU in the 1.333–1.338 RIU range. A salinity sensor has been implemented as a practical application of this proposed structure. Fast Fourier transform (FFT) analysis and tracking of an interference dip were used to monitor the interference between modes obtaining sensitivities of 0.99 nm/PSU and 0.025 rad/PSU, respectively

Cysticercose of the central nervous system: II. Spinal cysticercose

The compromising of the spinal canal by cysticercus is considered infrequent, varying from 16 to 20% in relation to the brain involvement. In the spinal canal the cysticercus predominantly places in the subarachnoid space. Clinical signs in spinal cysticercosis can be caused by direct compression of the spinal cord/roots by cisticerci and by local or at distance inflammatory reactions (arachnoiditis). Another mechanism of lesion is degeneration of the spinal cord due to pachymeningitis or circulatory insufficiency. The most frequent clinical features are signs of spinal cord and/or cauda equina compression. The diagnosis of spinal cysticercosis is based on evidence of cerebral cysticercosis and on neuroradiological examinations (myelography and myelo-CT) that show signs of arachnoiditis and images of cysts in the subarachnoid space and sometimes, signs of intramedullary lesions, but the confirmation can only be made through immunological reactions in the CSF or during surgery. The clinical course of 10 patients with diagnosis of spinal cysticercosis observed among 182 patients submitted to surgical treatment due to this diasease are analyzed. The clinical pictures in all cases were signs of spinal cord or roots compression. All but two presented previously signs of brain cysticercosis. Neuroradiological examinations showed signs of arachnoiditis in 4 patients, images of cysts in the subarachnoid space in 5, and signs of arachnoiditis and images of cysts in one. The 6 patients that presented intraspinal cysts were submitted to exeresis of the cysts and 2 patients with total blockage of the spinal canal underwent surgery for diagnosis. The 2 remaining patients with arachnoiditis and blockge of the spinal canal were clinically treated. All of the six patients submitted to cyst exeresis had initial improvement but 4 of them later developed arachnoiditis and recurrence of the clinical signs and only 2 remained well for long-term. The 2 non operated patients had no improvement of their clinical signs. Two patients died later due to complications of cerebral cysticercosis. Based on the experience acquired in the management of these patients we indicate surgical treatment for patients that present free cyst in subarachnoid space. For those who present arachnoiditis, surgery is indicated only when there is doubt in the diagnosis. Intramedullary cysts should also be surgically treated

Biodiversidad 2018. Reporte de estado y tendencias de la biodiversidad continental de Colombia

Las cifras y temáticas contenidos en el presente Reporte, aunque no son el panorama completo del estado del conocimiento de la biodiversidad en Colombia, son un compendio seleccionado de los temas que, desde el Instituto Humboldt, consideramos son relevantes y merecen ser discutidos por el público general. En muchos de los casos, las cifras no son esperanzadoras u son un llamado urgente a la acción. En otro casos son la evidencia de que se requieren acciones a nivel nacional, y más allá de esto, son muchas las iniciativas que están germinando desde los territorios, cada vez desde una mayor variedad de actores.Bogotá, D. C., Colombi

Biodiversidad 2017. Estado y tendencias de la biodiversidad continental de Colombia

En la cuarta versión del Reporte, que corresponde al año 2017, es una obligación preguntarnos cuál ha sido y es el papel de esta publicación y si ha abarcado la diversidad de formas y conceptos que definen el estado y el futuro de la biodiversidad colombiana. Las temáticas que constituyen la columna vertebral de cada uno de los reportes anuales responden a temas de pertinencia, nivel de incidencia y actualidad desde cada uno de los diferentes niveles de organización de la biodiversidad y buscan responder las siguientes preguntas fundamentales: 1) ¿Cómo se encuentra la biodiversidad del país? 2)¿Qué factores, en dónde y en qué medida está siendo afectada? 3)¿Cuáles son las iniciativas que desde la sociedad civil o a nivel de políticas públicas buscan evitar esa pérdida? 4)¿Cuáles son las grandes oportunidades para mejorar su gestión y manejo? Si bien evaluar la incidencia que puede tener el Reporte sobre acciones de gestión no es tarea fácil, se debe reconocer la buena acogida que han tenido los textos, las ilustraciones y la cifras entre los distintos tipos de lectores y el papel fundamental que ha jugado el Reporte en comunicar información de altísima calidad sobre la biodiversidad colombiana en diferentes momentos coyunturales. En ese sentido esta publicación es cada vez más una herramienta de consulta y referencia que está abierta al público tanto en formato impreso como digital, y de la misma manera busca fortalecerse para continuar brindando información relevante para la toma de decisiones en materia ambiental.BogotáSubdirección de Investigacione