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The effect of chitosan as internal or external coating on the mesalamine (5-ASA) release from calcium alginate microparticles (CaAl) was studied, and a delayed release of 5-ASA system intended for colonic drug delivery was developed. The external chitosan coating was developed by immersion of wetted CaAl in chitosan solution and the internal coating by(More)
Strain mapping is defined as a numerical image-processing technique that measures the local shifts of image details around a crystal defect with respect to the ideal, defect-free, positions in the bulk. Algorithms to map elastic strains from high-resolution transmission electron microscopy (HRTEM) images may be classified into two categories: those based on(More)
In this article a method for determining errors of the strain values when applying strain mapping techniques has been devised. This methodology starts with the generation of a thickness/defocus series of simulated high-resolution transmission electron microscopy images of InAsxP1-x/InP heterostructures and the application of geometric phase. To obtain(More)
Aberration-corrected scanning transmission electron microscopy (STEM) is used to reveal individual Au atom configurations inside Si nanowires grown by Au-catalyzed vapor-liquid-solid (VLS) molecular beam epitaxy (MBE). We identify a substitutional and three distinct interstitial configurations, one of which has not been previously identified. We confirm the(More)
In this work we examined MoS₂ sheets by aberration-corrected scanning transmission electron microscopy (STEM) at three different energies: 80, 120 and 200 kV. Structural damage of the MoS₂ sheets has been controlled at 80 kV according a theoretical calculation based on the inelastic scattering of the electrons involved in the interaction electron-matter.(More)
Motyxia species are bioluminescent, producing a greenish-blue light that gradually intensifies when the millipede is disturbed (Figure 1). Currently, eight of the 12,000 the 12,000 described millipede species are are known to be bioluminescent [5,6]. Here, we show that these species comprise a single clade and are geographically restricted to three counties(More)
A phenomenological method is developed to determine the composition of materials, with atomic column resolution, by analysis of integrated intensities of aberration-corrected Z-contrast scanning transmission electron microscopy images. The method is exemplified for InAs(x)P(1-x) alloys using epitaxial thin films with calibrated compositions as standards.(More)
We present experimental evidence of Sb incorporation inside InAs/GaAs(001) quantum dots exposed to an antimony flux immediately before capping with GaAs. The Sb composition profile inside the nanostructures as measured by cross-sectional scanning tunneling and electron transmission microscopies show two differentiated regions within the quantum dots, with(More)
We present the mapping of the full plasmonic mode spectrum for single and aggregated gold nanoparticles linked through DNA strands to a silicon nitride substrate. A comprehensive analysis of the electron energy loss spectroscopy images maps was performed on nanoparticles standing alone, dimers, and clusters of nanoparticles. The experimental results were(More)
Inclusion of spatial incoherence has been shown to give quantitative agreement between non-aberration-corrected high-angle annular dark-field scanning transmission electron microscopy images and theoretical simulations. Here we show that, using the same approach, a significant improvement in the correlation between calculated and experimental normalized(More)