Polymer optoelectronic structures for retinal prosthesis

This commentary highlights the effectiveness of optoelectronic properties of polymer semiconductors based on recent results emerging from our laboratory, where these materials are explored as artificial receptors for interfacing with the visual systems. Organic semiconductors based polymer layers in contact with physiological media exhibit interesting photophysical features, which mimic certain natural photoreceptors, including those in the retina. The availability of such optoelectronic materials opens up a gateway to utilize these structures as neuronal interfaces for stimulating retinal ganglion cells. In a recently reported work entitled ``A polymer optoelectronic interface provides visual cues to a blind retina,'' we utilized a specific configuration of a polymer semiconductor device structure to elicit neuronal activity in a blind retina upon photoexcitation. The elicited neuronal signals were found to have several features that followed the optoelectronic response of the polymer film. More importantly, the polymer-induced retinal response resembled the natural response of the retina to photoexcitation. These observations open up a promising material alternative for artificial retina applications.

Sensing of Stimulus Artifact Suppressed Signals From Electrode Interfaces

Stimulus artifacts inhibit reliable acquisition of biological evoked potentials for several milliseconds if an electrode contact is utilized for both electrical stimulation and recording purposes. This hinders the measurement of evoked short-latency biological responses, which is otherwise elicited by stimulation in implantable prosthetic devices. We present an improved stimulus artifact suppression scheme using two electrode simultaneous stimulation and differential readout using high-gain amplifiers. Substantial reduction of artifact duration has been shown possible through the common-mode rejection property of an instrumentation amplifier for electrode interfaces. The performance of this method depends on good matching of electrode-electrolyte interface properties of the chosen electrode pair. A novel calibration algorithm has been developed that helps in artificial matching of impedance and thereby achieves the required performance in artifact suppression. Stimulus artifact duration has been reduced down to 50 mu s from the stimulation-cum-recording electrodes, which is similar to 6x improvement over the present state of the art. The system is characterized with emulated resistor-capacitor loads and a variety of in-vitro metal electrodes dipped in saline environment. The proposed method is going to be useful for closed-loop electrical stimulation and recording studies, such as bidirectional neural prosthesis of retina, cochlea, brain, and spinal cord.

Llorar como Amadis / destruir como Orlando : una opción penitencial de don Quijote con vastas consecuencias

Integran este número de la revista ponencias presentadas en Studia Hispanica Medievalia VIII: Actas de las IX Jornadas Internacionales de Literatura Española Medieval, 2008, y de Homenaje al Quinto Centenario de Amadis de Gaula.

Impacto à saúde e ao meio ambiente do aumento irregular de solventes na gasolina

Mostra a toxicidade e os riscos de doenças que podem ser provocadas por solventes como benzeno, tolueno e xileno.

Extensão de benefícios aos portadores de narcolepsia

Avalia a conveniência de incluir a narcolepsia no rol das doenças cujos portadores usufruem de benefícios especificados em lei. Analisa também a regulamentação jurídica sobre o assunto.

Análise do Projeto de Lei nº 761, de 2007

Aborda o Projeto de Lei nº 761, de 2007, que institui a Política de Prevenção às Doenças Ocupacionais do Educador.

Diário da Constituinte [gravação de vídeo] : [programa n. 155]

Técnicos em reforma sanitária, representantes da Assembleia Nacional Constituinte (ANC) e o Ministro da Saúde, Sr. Roberto Santos, reuniram-se para debater o tema: a saúde e a Constituinte. Segundo o ministro Roberto Santos o projeto de Constituição atual é um avanço quando coloca a saúde como um direito do cidadão e dever do Estado. A questão da saúde faz parte do título geral do projeto de Constituição, que trata da ordem social. No Artigo 350 fica determinado que o Estado deve criar políticas para eliminar ou reduzir o risco de doenças e garantir o acesso universal e gratuito à saúde. O Deputado José Elias Murad (PTB-MG) esclarece que este princípio significa que, em qualquer parte do país, qualquer brasileiro terá direito ao atendimento médico gratuito. O Deputado Arnaldo Faria de Sá (PTB-SP) vai apresentar um projeto de decisão para colocar já em votação a duração do mandato do Presidente José Sarney. Segundo ele, é necessário votar logo esse tema para que a Constituinte possa trabalhar em paz. Segundo o Regimento da Comissão de Sistematização, um projeto de decisão é todo assunto que precisa ser discutido quando surgir uma ameaça aos trabalhos da Constituinte. O Deputado Nilson Gibson (PMDB-PE) declara que a questão do mandato do presidente como um fato jurídico constituído, um direito adquirido. O Deputado Adolfo Oliveira (PL-RJ) afirma que é preciso caminhar para uma Constituição nova, com tudo reformado, tudo revisado e votação direta para todos os cargos eletivos. O Deputado Augusto Carvalho (PCB-DF), em nome do partido, apoia as eleições diretas para presidente da república em 1988. O Deputado Virgildásio Sena (PMDB-BA) afirma que não é a hora de decidir o mandato do presidente, já que ainda não se decidiu nem o sistema de governo. O Deputado Euclides Scalco (PMDB-PR) entende que é o momento de discutir na Comissão de Sistematização a questão do mandato do presidente e do regime de governo. O Deputado Ulysses Guimarães (PMDB-SP) entende que o Plenário é o fórum próprio para discutir o mandato e o sistema de governo, quando for votado o substitutivo.

O sistema bicameral sob a perspectiva da eficiência e rendimento do processo legislativo brasileiro nas casas revisoras - um estudo na área da saúde

Estudo sobre o processo legislativo e as proposições de iniciativa dos deputados que tramitaram no sistema de revisão bicameral durante o período de 2007 a 2011. Concentra-se na análise do sistema bicameral brasileiro, sob a perspectiva dos projetos de lei de iniciativa parlamentar na Câmara dos Deputados de matérias concernentes à saúde, com o propósito de observar o desempenho legiferante da Casa revisora. O estudo se desenvolveu em dois momentos: primeiro, sob o aspecto da análise das alterações demandadas no Senado e segundo, com a observação do tempo demandado para a revisão bicameral neste sistema de ¿idas e vindas¿ entre as Casas. Foi avaliada a qualidade temática das matérias das proposições e identificada a preferência da demanda parlamentar por projetos de cunho simbólico/burocrático, precedendo a políticas que visam a prevenção de doenças, seguidos de medidas que objetivam reduzir os riscos à saúde. Classificou-se também projetos para regulamentação de acordos internacionais e doações e projetos que dispõem sobre a proteção de direitos na área da saúde.

Algorithms for colour image processing based on neurological models

373 p. : il., gráf., fot., tablas

Guia de saúde bucal : saúde bucal e sua relação com a saúde do corpo

Guia de assistência médica e odontológica, com informações sobre saúde e prevenção de diversas doenças bucais.

Design,optimization and in vivo evaluation of non-viral vectors for gene therapy. Applications in ocular disorders

227 págs.

Dextran and protamine-based solid lipid nanoparticles as potential vectors for the treatment of X-linked juvenile retinoschisis

This is a copy of an article published in the Human gene therapy © 2012 copyright Mary Ann Liebert, Inc.; Human gene therapy is available online at: http://online.liebertpub.com.

Desarrollo de nanopartículas sólidas lipídicas como sistemas de administración de ADN para terapia génica

290 p. (Bibliogr. 257-290) Correo electrónico de la autora: ana.delpozo@ehu.es

Wireless parylene-based retinal implant

The degeneration of the outer retina usually causes blindness by affecting the photoreceptor cells. However, the ganglion cells, which consist of optic nerves, on the middle and inner retina layers are often intact. The retinal implant, which can partially restore vision by electrical stimulation, soon becomes a focus for research. Although many groups worldwide have spent a lot of effort on building devices for retinal implant, current state-of-the-art technologies still lack a reliable packaging scheme for devices with desirable high-density multi-channel features. Wireless flexible retinal implants have always been the ultimate goal for retinal prosthesis. In this dissertation, the reliable packaging scheme for a wireless flexible parylene-based retinal implants has been well developed. It can not only provide stable electrical and mechanical connections to the high-density multi-channel (1000+ channels on 5 mm × 5 mm chip area) IC chips, but also survive for more than 10 years in the human body with corrosive fluids.

The device is based on a parylene-metal-parylene sandwich structure. In which, the adhesion between the parylene layers and the metals embedded in the parylene layers have been studied. Integration technology for high-density multi-channel IC chips has also been addressed and tested with dummy and real 268-channel and 1024-channel retinal IC chips. In addition, different protection schemes have been tried in application to IC chips and discrete components to gain the longest lifetime. The effectiveness has been confirmed by the accelerated and active lifetime soaking test in saline solution. Surgical mockups have also been designed and successfully implanted inside dog's and pig's eyes. Additionally, the electrodes used to stimulate the ganglion cells have been modified to lower the interface impedance and shaped to better fit the retina. Finally, all the developed technologies have been applied on the final device with a dual-metal-layer structure.

Molecular neurogenetics of eye development in Drosophila

The compound eye of Drosophila melanogaster begins to differentiate during the late third larval instar in the eye-antennal imaginal disc. A wave of morphogenesis crosses the disc from posterior to anterior, leaving behind precisely patterned clusters of photoreceptor cells and accessory cells that will constitute the adult ommatidia of the retina. By the analysis of genetically mosaic eyes, it appears that any cell in the eye disc can adopt the characteristics of any one of the different cell types found in the mature eye, including photoreceptor cells and non-neuronal accessory cells such as cone cells. Therefore, cells within the prospective retinal epithelium assume different fates presumably via information present in the environment. The sevenless^+ (sev^+) gene appears to play a role in the expression of one of the possible fates, since the mutant phenotype is the lack of one of the pattern elements, namely, photoreceptor cell R7. The sev^+ gene product had been shown to be required during development of the eye, and had also been shown in genetic mosaics to be autonomous to presumptive R7. As a means of better understanding the pathway instructing the differentiation R7, the gene and its protein product were characterized.

The sev+ gene was cloned by P-element transposon tagging, and was found to encode an 8.2 kb transcript expressed in developing eye discs and adult heads. By raising monoclonal antibodies (MAbs) against a sev^+- β-galactosidase fusion protein, the expression of the protein in the eye disc was localized by immuno-electronmicroscopy. The protein localizes to the apical cell membranes and microvilli of cells in the eye disc epithelium. It appears during development at a time coincident with the initial formation of clusters, and in all the developing photoreceptors and accessory cone cells at a time prior to the overt differentiation of R7. This result is consistent with the pluripotency of cells in the eye disc. Its localization in the membranes suggests that it may receive information directing the development of R7. Its localization in the apical membranes and microvilli is away from the bulk of the cell contacts, which have been cited as a likely regions for information presentation and processing. Biochemical characterization of the sev^+ protein will be necessary to describe further its role in development.

Other mutations in Drosophila have eye phenotypes. These were analyzed to find which ones affected the initial patterning of cells in the eye disc, in order to identify other genes, like sev, whose gene products may be involved in generating the pattern. The adult eye phenotypes ranged from severe reduction of the eye, to variable numbers of photoreceptor cells per ommatidium, to sub de defects in the organization of the supporting cells. Developing eye discs from the different strains were screened using a panel of MAbs, which highlight various developmental stages. Two identified matrix elements in and anterior to the furrow, while others identified the developing ommatidia themselves, like the anti-sev MAb. Mutation phenotypes were shown to appear at many stages of development. Some mutations seem to affect the precursor cells, others, the setting up of the pattern, and still others, the maintenance of the pattern. Thus, additional genes have now been identified that may function to support the development of a complex pattern.