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Some genetically based degenerative illnesses of retina cause total or partial blindness in ∼ 1 / 4000 people totaling ∼ 1. 5 million visually impaired. No cure is available and the only chance of improved vision is a visual prosthesis replacing the damaged retina. Some projects have delivered interesting but still not fully satisfactory results in the last 20 years. An innovative approach based on subretinic implant of SiPM exploiting its internal amplification is presented. Progress in implementing this approach is presented. [ABSTRACT FROM AUTHOR]

The optical matrix formalism is developed by applying Snell law to describe the refraction of optical rays in a spherical surface. This formalism is then applied to find and justify typical parameters and expressions as focal distance, image condition and lateral magnification for a thin spherical lenses immerse in air. Also, the case of thin spherical lenses immersed in two media with different refraction index is studied, and the corresponding parameters and expressions are found. [ABSTRACT FROM AUTHOR]

Yessotoxins (YTXs) are algal toxins that can be accumulated in edible molluscs. YTX treatment of MCF-7 breast cancer cells causes the accumulation of a 100 kDa fragment of E-cadherin, which we have named ECRA(100). A relative decrease in the concentrations of intact E-cadherin did not accompany the accumulation of ECRA(100) in cytosoluble extracts of MCF-7 cells on the first day of YTX treatment, but a collapse of the E-cadherin system was detected after 2-5 days of treatment with the toxin. An analysis of the general structure of ECRA(100) revealed that it consists of an E-cadherin fragment lacking the intracellular domain of the protein. ECRA(100) was not released into culture media of YTX-treated cells. Accumulation of ECRA(100) was observed in other epithelial cells, such as human intestine Caco-2 and MDCK cells after treatment with YTX. In turn, YTX could not induce accumulation of fragments of other members of the cadherin family, such as N-cadherin in the PC12 cell line and K-cadherin in sensitive cells (MCF-7, Caco-2, MDCK). The accumulation of a 100 kDa fragment of E-cadherin devoid of its intracellular domain induced by YTX was accompanied by reduced levels of beta- and gamma-catenins bound to E-cadherin, without a concomitant decrease in the total cytosoluble pools of beta- and gamma-catenins. Taken together, the results we obtained show that YTX causes the selective disruption of the E-cadherin-catenin system in epithelial cells, and raise some concern about the potential that an algal toxin found in seafood might disrupt the tumour suppressive functions of E-cadherin. [ABSTRACT FROM AUTHOR]

A capillary light source was used to observe the spectrum of eight times-ionized xenon, Xe IX, in the vacuum ultraviolet range, 270–1300 A˚. One hundred and nine transitions have been identified as combinations between levels of the 4d95d with 4d95p and 4d95f configuration. Seventeen levels have been determined that belong to the 4d95d configuration, and 15 belong to the 4d95f configuration. The energy parameters were obtained with Hartree–Fock relativistic calculations. Least-squares parametric calculation has been carried out to study the fit between experimental and theoretical values. [Copyright &y& Elsevier]

We demonstrate simultaneous compensation of loss and chromatic dispersion for 10-Gb/s transmission over 90-km of standard fiber using mid-span phase conjugation with a fiber-optic parametric amplifier that provides 9.4-dB gain over a bandwidth of 17 nm. The observed power penalty is less than 1.5 dB (at BER < 10-9) relative to back-to-back measurements. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 503–505, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20350 [ABSTRACT FROM AUTHOR]

It is experimentally demonstrated that fibre four-wave mixing may be used to optically multiplex two binary signals into a single quaternary one. The behaviour of this quaternary signal is investigated as a function of the extinction ratios of the input binary signals and a very good agreement is found with theoretical predictions. [ABSTRACT FROM AUTHOR]