Matches in SemOpenAlex for { <https://semopenalex.org/work/W2006702403> ?p ?o ?g. }
- W2006702403 endingPage "470" @default.
- W2006702403 startingPage "461" @default.
- W2006702403 abstract "Energy-filtered Analytical Electron Microscopy (AEM) was used to image the ultrastructure and determine quantitatively the chemical composition of rat melanosomes of the choroid and the Retinal Pigment Epithelium (RPE). For the first time, the effect of staining in elemental analysis of melanosomes was investigated. Detection limits and accuracies of the applied methods were determined. Compared to previous work applying only quantitative Energy Dispersive X-ray microanalysis (EDX) in the TEM (Eibl, O., et al., 2006. Micron 37, 262), here we present a combined quantitative EDX and Electron Energy Loss Spectroscopy (EELS) analysis, including N. This yields the fraction of eumelanin and pheomelanin in melanosomes by the S/N mole fraction ratio. Melanosomes of the sepia ink sac, used as eumelanin standard, showed an S/N mole fraction ratio of <0.004. Thus, they consist primarily of eumelanin as reported by degradation analysis. In contrast, melanosomes of the rats contained mixed melanin with significant amounts of pheomelanin (S/N 0.02) in the RPE and the choroid. Consistent with the previous publication, it was shown that oxygen mole fractions are especially large in melanosomes (7-10 at.%) compared to other cell compartments, e.g. 2-4 at.% oxygen in the cytoplasm. In the melanosomes of non-stained tissue, the oxygen mole fraction clearly correlated with the Ca mole fraction. EDX spectra used for quantitative analysis had about 15,000 net counts under the oxygen peak, which is necessary to obtain (i) a small statistical error for oxygen and (ii) optimum minimum detectable mole fractions for S, Ca and transition metals. The precise determination of the oxygen mole fraction in melanosomes is important for understanding metabolism. Therefore, a detailed analysis was carried out on the possible errors affecting quantification. While O, S, and N mole fractions yielded similar results in stained and non-stained ocular melanosomes of rats, transition metals can only be determined reliably in non-stained tissues. High-precision EDX analysis of melanosomes yielded minimum detectable mole fractions of less than 0.04 at.% for Cu and Zn, these elements were present in melanosomes with mole fractions of about 0.3 at.% and 0.1at.%, respectively. Zn is of great importance for metabolism and for age related macular degeneration. Its mole fraction in melanosomes of rats is large enough to be detected and to be quantitatively analyzed by EDX spectroscopy. Ultrastructural information can now be correlated to the elemental composition. This is important to better understand the physical and chemical properties of melanosomal metabolism and turnover." @default.
- W2006702403 created "2016-06-24" @default.
- W2006702403 creator A5029514816 @default.
- W2006702403 creator A5036570779 @default.
- W2006702403 creator A5064834609 @default.
- W2006702403 date "2011-07-01" @default.
- W2006702403 modified "2023-10-02" @default.
- W2006702403 title "Quantitative chemical analysis of ocular melanosomes in stained and non-stained tissues" @default.
- W2006702403 cites W1965708269 @default.
- W2006702403 cites W1967503317 @default.
- W2006702403 cites W1968040857 @default.
- W2006702403 cites W1968209883 @default.
- W2006702403 cites W1969059730 @default.
- W2006702403 cites W1998745344 @default.
- W2006702403 cites W2007348919 @default.
- W2006702403 cites W2011210363 @default.
- W2006702403 cites W2016798351 @default.
- W2006702403 cites W2027123175 @default.
- W2006702403 cites W2035544794 @default.
- W2006702403 cites W2037055237 @default.
- W2006702403 cites W2037094500 @default.
- W2006702403 cites W2038683683 @default.
- W2006702403 cites W2046869274 @default.
- W2006702403 cites W2048409658 @default.
- W2006702403 cites W2048817023 @default.
- W2006702403 cites W2053140255 @default.
- W2006702403 cites W2086684945 @default.
- W2006702403 cites W2093126983 @default.
- W2006702403 cites W2111025546 @default.
- W2006702403 cites W2111855289 @default.
- W2006702403 cites W2113638290 @default.
- W2006702403 cites W2134091914 @default.
- W2006702403 cites W2345821300 @default.
- W2006702403 cites W2411031570 @default.
- W2006702403 cites W4247072832 @default.
- W2006702403 doi "https://doi.org/10.1016/j.micron.2011.01.004" @default.
- W2006702403 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/21330141" @default.
- W2006702403 hasPublicationYear "2011" @default.
- W2006702403 type Work @default.
- W2006702403 sameAs 2006702403 @default.
- W2006702403 citedByCount "20" @default.
- W2006702403 countsByYear W20067024032012 @default.
- W2006702403 countsByYear W20067024032013 @default.
- W2006702403 countsByYear W20067024032014 @default.
- W2006702403 countsByYear W20067024032015 @default.
- W2006702403 countsByYear W20067024032016 @default.
- W2006702403 countsByYear W20067024032018 @default.
- W2006702403 countsByYear W20067024032022 @default.
- W2006702403 countsByYear W20067024032023 @default.
- W2006702403 crossrefType "journal-article" @default.
- W2006702403 hasAuthorship W2006702403A5029514816 @default.
- W2006702403 hasAuthorship W2006702403A5036570779 @default.
- W2006702403 hasAuthorship W2006702403A5064834609 @default.
- W2006702403 hasConcept C107538193 @default.
- W2006702403 hasConcept C113196181 @default.
- W2006702403 hasConcept C124815738 @default.
- W2006702403 hasConcept C147789679 @default.
- W2006702403 hasConcept C178790620 @default.
- W2006702403 hasConcept C185592680 @default.
- W2006702403 hasConcept C2780886089 @default.
- W2006702403 hasConcept C36591836 @default.
- W2006702403 hasConcept C43617362 @default.
- W2006702403 hasConcept C45326173 @default.
- W2006702403 hasConcept C540031477 @default.
- W2006702403 hasConcept C55493867 @default.
- W2006702403 hasConcept C59822182 @default.
- W2006702403 hasConcept C86803240 @default.
- W2006702403 hasConcept C94435474 @default.
- W2006702403 hasConcept C95986675 @default.
- W2006702403 hasConceptScore W2006702403C107538193 @default.
- W2006702403 hasConceptScore W2006702403C113196181 @default.
- W2006702403 hasConceptScore W2006702403C124815738 @default.
- W2006702403 hasConceptScore W2006702403C147789679 @default.
- W2006702403 hasConceptScore W2006702403C178790620 @default.
- W2006702403 hasConceptScore W2006702403C185592680 @default.
- W2006702403 hasConceptScore W2006702403C2780886089 @default.
- W2006702403 hasConceptScore W2006702403C36591836 @default.
- W2006702403 hasConceptScore W2006702403C43617362 @default.
- W2006702403 hasConceptScore W2006702403C45326173 @default.
- W2006702403 hasConceptScore W2006702403C540031477 @default.
- W2006702403 hasConceptScore W2006702403C55493867 @default.
- W2006702403 hasConceptScore W2006702403C59822182 @default.
- W2006702403 hasConceptScore W2006702403C86803240 @default.
- W2006702403 hasConceptScore W2006702403C94435474 @default.
- W2006702403 hasConceptScore W2006702403C95986675 @default.
- W2006702403 hasIssue "5" @default.
- W2006702403 hasLocation W20067024031 @default.
- W2006702403 hasLocation W20067024032 @default.
- W2006702403 hasOpenAccess W2006702403 @default.
- W2006702403 hasPrimaryLocation W20067024031 @default.
- W2006702403 hasRelatedWork W1801368582 @default.
- W2006702403 hasRelatedWork W2006702403 @default.
- W2006702403 hasRelatedWork W2010575643 @default.
- W2006702403 hasRelatedWork W2050854866 @default.
- W2006702403 hasRelatedWork W2086684945 @default.
- W2006702403 hasRelatedWork W2109763160 @default.
- W2006702403 hasRelatedWork W2146756538 @default.
- W2006702403 hasRelatedWork W2183189420 @default.