Metal artifacts drastically impair the image quality in CT images and often reduce their diagnostic value. There are many publications on metal artifact reduction (MAR) which regard the ...metal-affected parts of the rawdata as completely unreliable and therefore replace it. While those sinogram inpainting methods are in general successful in removing metal artifacts, they cannot exactly recover the true values which are replaced and therefore the corrected image will exhibit new artifacts and blurring.
The influence of high temperature oxygen annealing on (100) oriented donor-doped SrTiO^sub 3^ single crystals was studied. Crystalline precipitates were found on the optical scale on surfaces of ...lanthanum-doped as well as niobium-doped specimens with donor concentrations above 0.5 at.%. The amount of the secondary phase increases with the doping level, oxidation temperature and oxidation time. EDX analyses of the crystallites reveal a SrO^sub x^ composition. The formation of the observed secondary phase is discussed by means of the defect re-equilibration of the cation sub-lattice. In view of the point defect model for donor-doped perovskites, n-conducting SrTiO^sub 3^ changes its compensation mechanism during an oxidation treatment from "electronic compensation" (N^sub D^ = n) to "self-compensation" (N^sub D^ = 2V^sub Sr^'') by forming cation vacancies. Due to the favored Schottky-type disorder in perovskites, the formation of strontium vacancies is accompanied by a release of strontium from the regular lattice. Since the excess strontium is found to be situated at the surface in form of SrO-rich precipitates only, we propose the formation of strontium vacancies via a surface defect reaction and the chemical diffusion of strontium vacancies from the surface into the crystal as the most probable re-equilibration mechanism for the oxidation treatment of single crystals. The introduced mechanism is in contrast to an established model which proposes the formation of Ruddlesden-Popper intergrowth phases SrO·(SrTiO^sub 3^)^sub n^ in the interior of the crystal.PUBLICATION ABSTRACT
Verbal imagery and visual images as well as the intricate relationships between verbal and visual representations have long shaped the imagination and the practice of intercultural relationships. The ...contributions to this volume take a fresh look at the ideology of form, especially the gendered and racial implications of the gaze and the voice in various media and intermedial transformations. Analyses of how culturally specific forms of visual and verbal expression are individually understood and manipulated complement reflections on the potential and limitations of representation. The juxtaposition of visual and verbal signifiers explores the gap between them as a space beyond cultural boundaries. Topics treated include: Caliban; English satirical iconotexts; Oriental travel writing and illustration; expatriate description and picturesque illustration of Edinburgh; ethnographic film; African studio photography; South African cartoons; imagery, ekphrasis, and race in South African art and fiction; face and visuality, representation and memory in Asian fiction; Bollywood; Asian historical film; Asian-British pop music; Australian landscape in painting and fiction; indigenous children's fiction from Aotearoa New Zealand, Canada, and the USA; Canadian photography; Native Americans in film. Writers and artists discussed include: Philip Kwame Apagya; the Asian Dub Foundation; Breyten Breytenbach; Richard Burton; Peter Carey; Gurinder Chadha; Daniel Chodowiecki; J.M. Coetzee; Ashutosh Gowariker; Patricia Grace; W. Greatbatch; Hogarth; Francis K. Honny; Jim Jarmusch; Robyn Kahukiwa; Seydou Keita; Thomas King; Vladyana Krykorka; Alfred Kubin; Michael Arvaarluk Kusugak; Kathleen and Michael Lacapa; László Lakner; George Littlechild; Ken Lum; Franz Marc; Zakes Mda; Ketan Mehta; M.I.A. (Maya Arulpragasam); Timothy Mo; William Kent Monkman; Lady Mary
Wortley Montagu; John Hamilton Mortimer; Sidney Nolan; Jean Rouch; Salman Rushdie; William Shakespeare; Robert Louis Stevenson; Richard Van Camp; Zapiro.
Renal uptake of an 18-mer phosphorothioate oligonucleotide. Renal uptake of a 35S labeled 18-mer phosphorothioate oligodeoxynucleotide (molecular wt ˜ 6,000) was evaluated following intravenous ...infusion into rats. The kidneys contained 21 ± 3% of the infused dose at five hours after infusion and 3 ± 1% of the infused dose at four days after infusion. The concentration of oligonucleotide was greater in the kidney than in the liver, spleen, or plasma at both intervals. Urine excretion of oligonucleotide label averaged 17 ± 1%, 35 ± 5%, and 64 ± 3% of the infused dose at five hours, one day, and four days after infusion. Electrophoresis (PAGE) showed that oligonucleotide was retained in the kidney as the intact 18-mer at both five hours and four days after infusion, while full size oligonucleotide was not found in the urine at either interval. Light microscopic autoradiography showed that oligonucleotide uptake was most prominent in the early proximal tubule. Electron microscopic autoradiography indicated that oligonucleotide was not confined to the brush border or endocytic-lysosomal pathway. Micropuncture studies showed that the tubule fluid to plasma concentration ratios of oligonucleotide label averaged 7 ± 3% in Bowman's space and 6 ± 2% in the distal tubule. Despite restriction of filtration by plasma protein binding, as indicated by the low Bowman's space to plasma concentration ratio, the calculated tubular reabsorption rate for oligonucleotide was sufficient to account for the large amount of oligonucleotide found in the kidney after intravenous infusion. These results indicate that the proximal tubule plays a prominent role in the disposition of intravenously infused oligonucleotide, and raise the possibility that oligonucleotides could exert antisense effects in this nephron segment.
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