Sustitución del Menisco por Pericondrio Auricular: estudio experimental

Los autores realizan un estudio experimental en la rat a sustituyendo el menisco por pericondrio auricular, unas veces en forma plana y otras plegado en U. Ello provoca una respuesta reparativa con formación de verdadero cartílago. Cuando el pericondrio se injerta plegado en U de forma que la superficie de ruptura de las cápsulas condrocitarias se enfrenten entre sí, se asiste a la neoformación de dos clases de cartílago, una que aparece en la capa más interna del pericondrio y otro en las zonas de repliegue de éste último. Se discute el posible origen de estos dos tipos de neocartílago.The authors carry out an experimental study to evaluat e the replacement of the medial meniscus in the rat kne e by auricular perichondrial grafts (simple or plicated).This bring about a reparative replay with formation of cartilage tissue. When the perichondrial graft was used at the plicated form, it could keep out two kinds of neoformated cartilage; the first appeared in the most internal stratum of the perichondrium; the second type was found in the withdrawal zone of it. The possible origen of the neocartilage form is discussed

Regeneración del Tronco Nervioso Periférico: estudio experimental

Los autores realizan un estudio en 24 ratas sometidas a axonectomía parcial subepineural o axonectomía y vaciamiento troncular, con objeto de valorar el comportamiento de los distintos elementos celulares del nervio durante la regeneración nerviosa. Durante el tiempo del experimento las células perineurales se conservan alrededor de un espacio virtual, lo que se interpreta como que intervienen como aislante, aún en condiciones de ausencia de fibras nerviosas, impidiendo la entrada de estructuras vasculares neoformadas y la cicatrización intraperineural. Por todo ello se postula que el papel de "guía" para el crecimiento de los axones regenerativos, atribuido fundamentalmente a las células de SCHWANN, debe ser revisado, en el sentido de dar un mayor protagonismo a las células perineurales.A study of 24 rats with partial subepineural axonectomy or axonectomy with trunckular casting was made in order to value the role of the diferent cellular elements of the nerve during his regeneration. In the experiment the perineural cells persist around a virtual space. This mean that the cells works like an insulate, also in absence of nerve fibres, impeding the neoformed vessels entrance and the perineural cicatrizacion. The role of the SCHWANN cells is cuestioned in front of the perineural cells importance

Estudio experimental de la Microangiografía del Tronco Ciático de la rata en situaciones de normalidad: compresión y descompresión

Se hace un estudio en 20 ratas sometidas a compresión del nervio ciático según variante de la técnica de WEISL y OSBORNE, y compresión-descompresión a tiempos variables y se estudia la microcirculación del mismo en estas situaciones, comparativamente con el nervio normal. Entre los cambios del patrón vascular en la compresión nerviosa, resalta la intensa vascularización de las zonas inmediatamente proximales y distales al a compresión, contrastando con la escasez de vasos en el área selectivamente comprimida. Después de la descompresión se apreció una recuperación paulatina del patrón vascular, sin que se llegase a alcanzar una cuantificación de vasos similar a la de las zonas adyacentes.A study in 20 rats with nerve sciatic compression (WEISL and OSBORNE method), and compression descompresión in diferent time s wa s made. The authors studied the sciatic nerve microcirculation in this situations in front of the normal nerve. They saw an intensive vascularization immediately after and before the place of the compression, and a vessels scarcity in the compression area. After the descompresion it saw a normal and slowly recuperation of the vascular role, but never so many vessels as in the proximal zones

Liquid phase epitaxy and spectroscopic investigation of optically active KYb(WO4)2 thin layers

In recent years, Yb3+ has attracted much attention as an activating ion because of its small quantum defect for laser emission from 2F5/2 to 2F7/2 at ~1.03 µm, which provides high efficiency and reduced heat generation. A promising material for Yb3+ lasers is KYb(WO4)2 (KYbW) [1]. It can be grown from high-temperature solutions [2]. A suitable substrate material for the growth of single-crystalline layers with thicknesses in the range of the absorption length of ~13 µm at 981 nm is KY(WO4)2 (KYW).\ud We demonstrate the liquid phase epitaxy (LPE) of KYbW layers at start temperatures as low as 520°C from the chloride solvent KCl-NaCl-CsCl. This temperature is favorable in order to decrease the thermal stresses due to the differences in the thermal expansion coefficients of substrate and layer. Moreover, the choice of [010]-oriented KYW substrates bypasses the large difference in the thermal expansion coefficient along the [010] direction. Our spectroscopic investigations show that the fluorescence lifetime of ~250 µs measured in our LPE-grown KYbW layers is dominated by radiative decay and is very similar to that measured in top-seeded-solution-grown bulk samples [2]. Fast energy migration among the Yb3+ ions and energy transfer to small amounts of Tm3+ and Er3+ ions present in the YbCl3 reagent lead to visible upconversion luminescence in the layers under 981-nm excitation.\ud \ud [1] P. Klopp, U. Griebner, V. Petrov, X. Mateos, M.A. Bursukova, M.C. Pujol, R. Solé, J. Gavaldà, M. Aguiló, F. Güell, J. Massons, T. Kirilov, F. Díaz, Appl. Phys. B 2002, 74, 185\ud [2] M.C. Pujol, M.A. Bursukova, F. Güell, X. Mateos, R. Solé, J. Gavaldà, M. Aguiló, J. Massons, F. Díaz, P. Klopp, U. Griebner, V. Petrov, Phys. Rev. B 2002, 65, 16512

Estudio histológico de la respuesta reparativa tras extirpación del menisco y parcial del Paramenisco: estudio experimental

Los autores efectúan un estudio en la rat a utilizando un modelo experimental de meniscectomía completa y extirpación parcial del paramenisco, comprobándose como se origina un proceso de regeneración que conduce a la formación de una nueva estructura, de aspecto meniscal, de menor tamaño que el primitivo menisco y formado por tejido fibroso con focos condroides.An experimental study was made in the rat with total meniscus extirpation. This study show a regeneration process that take us to a new structure formation like meniscus, with fibrous tissue formation with condroid points

Liquid phase epitaxy and optical investigation of KYb(WO4)2 thin layers

In recent years, Yb3+ has attracted much attention as an activating ion because of its small quantum defect for laser emission from 2F5/2 to 2F7/2 at ~1.03 µm [1], which provides high efficiency and reduced heat generation. Of high practical interest is the thin-disk laser concept [2], which possesses a tremendous advantage over rod lasers because of its axial-cooling approach and consequent weak thermal lensing and good beam quality.\ud A promising material for Yb3+ thin-disk lasers is KYb(WO4)2 (KYbW) [3]. It can be grown from high-temperature solutions [4]. Nevertheless, the growth of high-quality, single-crystalline layers with thickness in the range of the absorption length of ~13 µm at 981 nm has as yet not been reported. A suitable substrate material is KY(WO4)2 (KYW), but the relatively large differences in the thermal expansion coefficients between KYW and KYbW along the [100], [001], and especially [010] directions [5] favor low temperatures for the hetero-epitaxial growth.\ud For the first time, we demonstrate liquid phase epitaxy (LPE) of KYbW layers. The layers were grown at start temperatures as low as 520°C, which is favorable in order to decrease the thermal stresses due to the differences in the thermal expansion coefficients of substrate and layer. Moreover, the choice of [010]-oriented substrates bypasses the large difference in the thermal expansion coefficient along the [010] direction. KY1-xYbx(WO4)2 layers with varying x = 0.03-1.00 were grown by LPE. The chloride solvent consisted of the eutectic composition [6] 24.4 mol.% KCl, 30.4 mol.% NaCl, and 42.2 mol.% CsCl. The growth temperature spanned the range from 580 to 500°C and the cooling rate was 0.67-1.00 Kh-1. Crack-free, transparent KYbW layers were grown on (010) substrates.\ud Spectroscopic investigations have shown that the lifetime of ~250 µs measured in our LPE-grown KYbW layers is dominated by radiative decay and is very similar to that measured in top-seeded-solution-grown bulk samples [4]. Fast energy migration among the Yb3+ ions and energy transfer to small amounts of Tm3+ and Er3+ ions present in the YbCl3 reagent lead to visible upconversion luminescence in the layers under 981-nm excitation.\ud \ud [1] T.Y. Fan, IEEE J. Quantum Electron. 29, 1457 (1993).\ud [2] A. Giesen, H. Hügel, A. Voss, K. Wittig, U. Brauch, H. Opower, Appl. Phys. B 58, 365 (1994).\ud [3] P. Klopp, U. Griebner, V. Petrov, X. Mateos, M.A. Bursukova, M.C. Pujol, R. Solé, J. Gavaldà, M. Aguiló, F. Güell, J. Massons, T. Kirilov, F. Díaz, Appl. Phys. B 74, 185 (2002).\ud [4] M.C. Pujol, M.A. Bursukova, F. Güell, X. Mateos, R. Solé, J. Gavaldà, M. Aguiló, J. Massons, F. Díaz, P. Klopp, U. Griebner, V. Petrov, Phys. Rev. B 65, 165121 (2002).\ud [5] M.C. Pujol, X. Mateos, R. Solé, J. Massons, J. Gavaldà, F. Díaz, M. Aguiló, Mater. Sci. Forum 378-381, 710 (2001).\ud [6] D. Ehrentraut, M. Pollnau, S. Kück, Appl. Phys. B 75, 59 (2002)

Características Histológicas del Menisco de la rodilla durante el Desarrollo Intrauterino de la rata

Con el objetivo de profundizar en el conocimiento del desarrollo embriológico del esbozo meniscal de la rodilla, los autores realizan un estudio en embriones de rata de 16 y 20 días de gestación. Se comprueba como este esbozo meniscal, que en su inicio esta formado por una masa de células mesenquinales, adopta una configuración triangular al corte frontal, situada entre las dos superficies articulares. Posteriormente su vértice experimenta diferenciación cartilaginosa (futuro menisco), mientras que la región periférica sigue siendo altamente vascular y se continúa con tejido conjuntivo fibroso (zona parameniscal).An study in embryos of rat betwen 16-20 days of pregnancy was made to show the meniscus development. The meniscus sketch in the first time was made by mesenchyme cells, later takes a triangular configution. An at past his vertex became to be a cartilage (future meniscus), while the peripheral placer is highly vascular and is followed by a fibrous connective tissue (parameniscal zone)

Creative economy employment in the EU and the UK: a comparative analysis

Analysts and policymakers have long complained of the dearth of internationally comparable statistics on the creative industries because it has made it impossible to benchmark the performance of different countries. In January 2014, the Department for Culture, Media and Sport (DCMS) adopted the Dynamic Mapping methodology for classifying some industries as ‘creative’ and others not, for the purposes of producing the UK’s Creative Industries Economic Estimates (DCMS, 2014). This methodology is based on the theoretical and empirical argument that the creative industries are “those industries that specialise in the employment of creative talent for commercial purposes” (Bakhshi, Hargreaves and Mateos–Garcia, 2013) – that is, have unusually high proportions of their workforce employed in creative occupations (‘creative intensity’). Through its use of Standard Industrial Classification (SIC) codes and labour force survey data, the Dynamic Mapping methodology was designed to enable the production of internationally comparable statistics (Bakhshi, Freeman and Higgs 2013)

Management System for Harvest Scheduling: The Case of Horticultural Production in Southeast Spain

horticultural farmer, optimization, planning, mathematical programming, marketing, cooperative, Agribusiness, Crop Production/Industries, Demand and Price Analysis, Farm Management, Land Economics/Use,