Autologous transplantation of rabbit limbal epithelia cultured on fibrin gels for ocular surface reconstruction

Purpose: Regeneration of the corneal epithelium could be severely impaired in patients suffering from limbal stem cell deficiency. The purpose of this study was to evaluate the restoration of the corneal epithelium by grafting onto denuded corneas autologous limbal cells cultured on fibrin gels. The rabbit model was chosen to allow the microscopic evaluation over time after grafting. Methods: Rabbit limbal epithelial cells (RLECs) were isolated and cultured from small limbal biopsies (3 mm2 ). The epithelium was separated from stroma after dispase digestion and put in culture on lethally irradiated fibroblasts used as a feeder layer. At the first passage, RLECs were cultured on a fibrin gel matrix. At confluence, the cultured epithelia were grafted in vivo on denuded autologous rabbit corneas. At different postoperative times, grafted and control (without graft or grafted with fibrin gels only) rabbit corneas were compared in vivo with a slit lamp microscope, and in situ by histological and immunohistological microscopy of harvested biopsies. Results: A small limbal biopsy was sufficient to generate enough RLECs to prepare several grafts and to perform cell analysis. Only two weeks were required to produce a cultured epithelium suitable for autologous transplantation. One month after grafting, a normal corneal phenotype was observed on the ocular surface of grafted rabbits in contrast to the control rabbits (ungrafted or grafted with fibrin gel only) where histological signs of conjunctivalization were found. The absence of goblet cells and negative staining for keratin 4 confirmed that the cultured cells persisted and that the epithelium regenerated after grafting was not from conjunctival origin. Conclusions: Our results demonstrate that an autologous epithelium cultured on a physiologically biodegradable matrix can be prepared from a small biopsy and grafted on denuded cornea. The autologous graft allows epithelial regeneration from cultured cells and promotes corneal healing of unilateral total stem cell deficiency

Main Results of Phase IV BEMUSE Project: Simulation of LBLOCA in an NPP

Phase IV of BEMUSE Program is a necessary step for a subsequent uncertainty analysis. It includes the simulation of the reference scenario and a sensitivity study. The scenario is a LBLOCA and the reference plant is Zion 1 NPP, a 4 loop PWR unit. Thirteen participants coming from ten different countries have taken part in the exercise. The BEMUSE (Best Estimate Methods plus Uncertainty and Sensitivity Evaluation) Programhas been promoted by theWorking Group on AccidentManagement and Analysis (WGAMA) and endorsed by the Committee on the Safety of Nuclear Installations (CSNI). The paper presents the results of the calculations performed by participants and emphasizes its usefulness for future uncertainty evaluation, to be performed in next phase. The objectives of the activity are basically to simulate the LBLOCA reproducing the phenomena associated to the scenario and also to build a common, well-known, basis for the future comparison of uncertainty evaluation results among different methodologies and codes. The sensitivity calculations performed by participants are also presented. They allow studying the influence of different parameters such as material properties or initial and boundary conditions, upon the behaviour of the most relevant parameters related to the scenario

Iconografia tropical: motivos locais na arte colonial brasileira

Este artigo estuda a representação visual da natureza tropical na arte sacra do período colonial brasileiro, entre os séculos XVI e XVIII, época em que as artes visuais do país se desenvolveram no contexto do barroco introduzido pelos missionários católicos. Foi na decoração das igrejas que apareceram algumas das primeiras representações artísticas de elementos da natureza local, notadamente as frutas tropicais, produzindo novas combinações junto à tradicional ornamentação fitomórfica europeia, constituída de folhas de acantos e vinhas. Após um levantamento das ocorrências dessas manifestações da temática local na decoração dos templos presentes nas regiões nordeste e sudeste do país, este trabalho aborda, nos textos dos viajantes e missionários produzidos no período, as interpretações cristãs da natureza tropical que permitiram o aproveitamento desses motivos como parte da estratégia de pregação e conversão católica por meio da alegorização moral e religiosa da natureza do Novo Mundo.This paper studies the visual representation of local nature in the sacred art developed during the colonial period of Brazilian history. In this period, between the XVIth and the XVIIIth centuries, the visual arts in the country evolved in the context of the Baroque introduced by Catholic missionaries. It was in the decoration of the churches in which the first representations of aspects of local nature, mostly the tropical fruits, appeared in Brazilian visual arts, producing new combinations together with the traditional European phytomorphic ornamentation of acanthus leaves and grapes. This research draws upon texts written by travellers and missionaries during the period to demonstrate how the Europeans interpreted and represented tropical nature and used these representations as part of the Catholic preaching strategy by means of moral and religious allegorization of the New World nature

Discours de M. Germain Bazin

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Panofsky et la notion d'espace

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Notions d'archéologie et d'histoire de l'art

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Mona Lisa

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