Search results for "photor"
showing 10 items of 340 documents
Fabrication of a negative PMMA master mold for soft-lithography by MeV ion beam lithography
2012
Abstract In this study, poly(methyl methacrylate) (PMMA) was investigated as a negative resist by irradiation with a high-fluence 2 MeV proton beam. The beam from a 1.7 MV Tandetron accelerator at the Plasma and Beam Physics Research Facility (PBP) of Chiang Mai University is shaped by a pair of computer-controlled L-shaped apertures which are used to expose rectangular pattern elements with 1–1000 μm side length. Repeated exposure of rectangular pattern elements allows a complex pattern to be built up. After subsequent development, the negative PMMA microstructure was used as a master mold for casting poly(dimethylsiloxane) (PDMS) following a standard soft-lithography process. The PDMS chi…
Adhesion of proton beam written high aspect ratio hydrogen silsesquioxane (HSQ) nanostructures on different metallic substrates
2009
Abstract Hydrogen silsesquioxane (HSQ) behaves as a negative resist under MeV proton beam exposure. HSQ is a high-resolution resist suitable for production of tall (
Proton beam written hydrogen silsesquioxane (HSQ) nanostructures for Nickel electroplating
2009
Abstract Hydrogen silsesquioxane (HSQ) behaves as a negative resist under MeV proton beam exposure. HSQ is a high-resolution resist suitable for production of tall ( 1.5 μ m ) high-aspect-ratio nanostructures with dimensions down to 22 nm. High-aspect-ratio HSQ structures are required in many applications, e.g. nanofluidics, biomedical research, etc. Since P-beam writing is a direct and hence slow process, it is beneficiary to fabricate a reverse image of the patterns in a metallic stamp, e.g. by Ni electroplating. The Ni stamp can then be used to produce multiple copies of the same pattern. In this study we investigate the possibility to produce Ni stamps from p-beam written HSQ samples. H…
The giant spectrin βV couples the molecular motors to phototransduction and Usher syndrome type I proteins along their trafficking route.
2013
International audience; Mutations in the myosin VIIa gene cause Usher syndrome type IB (USH1B), characterized by deaf-blindness. A delay of opsin trafficking has been observed in the retinal photoreceptor cells of myosin VIIa-deficient mice. We identified spectrin bV, the mammalian b-heavy spectrin, as a myosin VIIa-and rhodopsin-interacting partner in photoreceptor cells. Spectrin bV displays a polarized distribution from the Golgi apparatus to the base of the outer segment, which, unlike that of other b spectrins, matches the trafficking route of opsin and other phototransduction proteins. Formation of spectrin bV-rhodopsin complex could be detected in the differentiating photoreceptors a…
Intraflagellar transport proteins in ciliogenesis of photoreceptor cells
2011
Background information. The assembly and maintenance of cilia depend on IFT (intraflagellar transport) mediated by molecular motors and their interplay with IFT proteins. Here, we have analysed the involvement of IFT proteins in the ciliogenesis of mammalian photoreceptor cilia. Results. Electron microscopy revealed that ciliogenesis in mouse photoreceptor cells follows an intracellular ciliogenesis pathway, divided into six distinct stages. The first stages are characterized by electron-dense centriolar satellites and a ciliary vesicle, whereas the formations of the ciliary shaft and the light-sensitive outer segment discs are features of the later stages. IFT proteins were associated with…
A photoresponsive graphene oxide-C60 conjugate.
2014
An all-carbon donor-acceptor hybrid combining graphene oxide (GO) and C60 has been prepared. Laser flash photolysis measurements revealed the occurrence of photoinduced electron transfer from the GO electron donor to the C60 electron acceptor in the conjugate
An siRNA-based functional genomics screen for the identification of regulators of ciliogenesis and ciliopathy genes
2015
Item does not contain fulltext Defects in primary cilium biogenesis underlie the ciliopathies, a growing group of genetic disorders. We describe a whole-genome siRNA-based reverse genetics screen for defects in biogenesis and/or maintenance of the primary cilium, obtaining a global resource. We identify 112 candidate ciliogenesis and ciliopathy genes, including 44 components of the ubiquitin-proteasome system, 12 G-protein-coupled receptors, and 3 pre-mRNA processing factors (PRPF6, PRPF8 and PRPF31) mutated in autosomal dominant retinitis pigmentosa. The PRPFs localize to the connecting cilium, and PRPF8- and PRPF31-mutated cells have ciliary defects. Combining the screen with exome sequen…
C21orf2 is mutated in recessive early-onset retinal dystrophy with macular staphyloma and encodes a protein that localises to the photoreceptor prima…
2015
Background/aim We have noted a phenotype of early-onset retinal dystrophy with macular staphyloma but without high myopia. The aim of this study is to report the underlying genetic mutations and the subcellular localisation of the gene product in the retina. Methods Retrospective case series (2012–2015); immunohistochemical analyses of mammalian retina for in situ protein localisation. Results All three probands were first noted to have decreased vision at 3–6 years old which worsened over time. At ages 39, 37 and 12 years old, all had similar retinal findings: dystrophic changes (retinal pigment epithelium mottling, vessel narrowing), macular staphyloma (despite only mild myopia or high hy…
An ultrastructural study on retinal neural and pigment epithelial cells in ovine neuronal ceroid-lipofuscinosis.
1990
Ovine neuronal ceroid-lipofuscinosis represents another well studied model for human neuronal ceroid-lipofuscinosis (NCL). Accumulation of abnormal lipopigments in various retinal neurons, and loss of photoreceptors are similar to the lesions in human juvenile NCL and indicate that the sheep is a suitable model in which to study the pathogenesis of both NCL lipopigment formation and retinopathia pigmentosa. However, this latter process is not as advanced in NCL-diseased sheep as in human patients but far more obvious than in canine NCL in which retinopathy cannot be unequivocally documented. Ovine NCL shares with canine NCL peculiar lamellar inclusions in retinal pigment epithelial cells wh…
Supplementary optical phase transition in photorefractive coherent oscillator
2001
The semilinear photorefractive coherent oscillator with two counterpropagating pump waves may exhibit two optical phase transitions: one from a disordered state of wide-angle photorefractive scattering into a high-ordered state with the immobile photorefractive grating and the other one from the state with immobile grating into the state with two moving photorefractive gratings. We show, both experimentally and from calculations, that two these phase transitions are the second-order phase transitions.