176 results about "Photoreceptor cell" patented technology

The invention provides a human visual perception simulation-based self-adaptive low-illumination image enhancement method. The method is put forwards based on characteristics of low brightness and low contrast of a low-illumination color image and through researching an automatic adjustment process of pupils and photoreceptor cells for an environment. The method includes the following steps that: the adjustment process of the pupils for light is simulated, and the total brightness level of the image is improved; and the self-adaptive adjustment and control ability of eye vision for a low-illumination environment is simulated, and a nonlinear mapping model is designed to simulate the adjustment process of rod cells and cone cells, so that a bright and dark self-adaptation function can be obtained, and a bright and dark information fusing function is determined according to illumination distribution, and global self-adaptive adjustment is performed on brightness components; and the local contrast of the enhanced brightness image will be decreased, so that local self-adaptive contrast enforcement is performed on the image through adopting an exponential function; and finally, and color restoration is performed on the enhanced image. With the human visual perception simulation-based self-adaptive low-illumination image enhancement method of the invention adopted, the brightness, local contrast and detail information of the low-illumination color image can be effectively improved, and especially, the method has obvious effects in dark area and highlight area enhancement.

Methods are provided for the production of photoreceptor cells and photoreceptor progenitor cells from pluripotent stem cells. Additionally provided are compositions of photoreceptor cells and photoreceptor cells, as well as methods for the therapeutic use thereof. Exemplary methods may produce substantially pure cultures of photoreceptor cells and / or photoreceptor cells.

The invention relates to imparting photoreactivity to target cells, e.g., retinal cells, by introducing photoresponsive functional abiotic nanosystems (FANs), nanometer-scale semiconductor / metal or semiconductor / semiconductor hetero-junctions that in this case include a photovoltaic effect. The invention further provides methods of making and using FANs, where the hetero-junctions bear surface functionalization that localizes them in cell membranes. Illumination of these hetero-junctions incorporated in cell membranes generates photovoltages that depolarize the membranes, such as those of nerve cells, in which FANs photogenerate action potentials. Incorporating FANs into the cells of a retina with damaged photoreceptor cells reintroduces photoresponsiveness to the retina, so that light creates action potentials that the brain interprets as sight.

Described herein are methods of preventing, arresting progression of or ameliorating vision loss and other conditions associated with retinitis pigmentosa and x-linked retinitis pigmentosa in a subject. The methods include administering to a subject an effective concentration of a composition comprising a recombinant adeno-associated virus (AAV) carrying a nucleic acid sequence encoding a normal retinitis pigmentosa GTPase regulator (RPGR gene), or fragment thereof, under the control of regulatory sequences which express the product of the gene in the photoreceptor cells of the subject, and a pharmaceutically acceptable carrier.