Search results for "electron microscopy"
showing 10 items of 706 documents
Electron microscopy of gold nanoparticles at atomic resolution
2014
Detailed structure of a gold nanoparticle Adding only a few atoms or changing the capping ligand can dramatically change the structure of individual metal nanoparticles. Azubel et al. used aberration-corrected transmission electron microscopy to derive a three-dimensional reconstruction of water-soluble gold nanoparticles. Small-angle x-ray scattering and other techniques have also corroborated this model. They used this to determine the atomic structure, which compared favorably with density functional theory calculations, without assuming any a priori structural knowledge or the use of model fitting. Science , this issue p. 909
Evidence for Myosin VIIa-Driven Transport of Rhodopsin in the Plasma Membrane of the Photoreceptor-Connecting Cilium
2007
Defects in the gene encoding for the unconventional myosin VIIa leads to human Usher syndrome 1B, the most common form of hereditary combined blindness and deafness. To determine cellular function of myosin VIIa, we have investigated the subcellular localization of myosin VIIa in spacial relation relationship to potentially interacting proteins in mammalian photoreceptor cells. Western blot analysis of the axonemal fraction of photoreceptor cells by Western blot show that myosin VIIa and actin, as well as opsin, were present in the ciliary portion of the photoreceptors. Improved immunoelectron microscopy revealed that in mammalian photoreceptor cells, myosin VIIa was localized at the membra…
On the synonymization of Acaulon longifolium Herrnst. & Heyn with Acaulon fontiquerianum Casas & Sérgio (Pottiaceae)
2021
During bryological work conducted in the Sharon plane region (Israel), a colony of Acaulon Müll. Hal. was discovered. The plants showed morphological affinities both to A. longifolium Herrnst. & Heyn and A. fontiquerianum Casas & Sérgio depending on the floras used for their identification which challenged their recognition as separate species. In order to solve this taxonomic dilemma, we conducted a detailed morphological characterization of the two species based on representative samples. The micromorphological study of vegetative, sporophytic and spore traits revealed the large overlap of range values between both species. Both species showed the characteristic combination of morphologic…
Mg2-xTixNi (x=0, 0.5) alloys prepared by mechanical alloying for electrochemical hydrogen storage: Experiments and first-principles calculations
2012
International audience; Mg2-xTixNi (x = 0, 0.5) electrode alloys have been prepared by mechanical alloying (MA) under argon atmosphere at room temperature using a planetary high-energy ball mill. The microstructures of synthesized alloys are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effects of substitutional doping of Ti in Mg2Ni phase have been investigated by first-principles density functional theory calculations. XRD analysis results indicate that Ti substitution for Mg in Mg2Ni-type alloys results in the formation of TiNi (Pm-3m) and TiNi3 intermetallics. With the increase of milling time, the TiNi phase…
Rational assembly and dual functionalization of Au@MnO heteroparticles on TiO2 nanowires
2014
Au–MnO heteroparticles were immobilized on the surface of TiO2 nanowires and tagged subsequently with a fluorescent ligand. The immobilization of the Au@MnO heteroparticles was achieved by functionalizing the TiO2 nanowire support with a polymer containing catechol anchor groups for binding to the metal oxide surface and amine groups for conjugation to the Au domains of the Au@MnO heteroparticles. The Au domain of the resulting TiO2@Au–MnO nanocomposite could be functionalized selectively with a thiol-tagged 24 mer oligomer containing Texas red (SH-ODN-TXS red), whereas a green dye (NBD–Cl) could be anchored selectively to the TiO2 “support” using the free amine groups of the polymeric liga…
Optimal degradation of Ciprofloxacin in a heterogeneous Fenton-like process using (δ-FeOOH)/MWCNTs nanocomposite
2021
Abstract This study was aimed at the synthesis and characterization of ( δ -FeOOH)/MWCNTs nanocomposite as the catalyst for Ciprofloxacin (CIP) removal through a heterogeneous Fenton-like process. The proposed experimental design applies the central composite design (CCD) as a response surface methodology (RSM). The effect of influential parameters, including initial CIP concentration, catalyst dose, H 2 O2 concentration, initial pH, and reaction time on removal, were investigated. ( δ -FeOOH)/MWCNTs nanocomposite was synthesized using a single-step co-precipitation technique. Besides, nano-feroxyhyte and nanocomposite properties were characterized by transmission electron microscopy (TEM),…
Spark plasma sintering of zirconia/nano-nickel composites
2015
Open Access
Au-PVA Nanocomposite Negative Resist for One-Step Three-Dimensional e-Beam Lithography
2009
Au nanoparticles are synthesized in situ upon the electron beam exposure of a poly(vinyl alcohol) (PVA) thin film containing Au(III). The e-beam-irradiated areas are insoluble in water (negative-tone resist), and Au-PVA nanocomposite patterns with a variable profile along the structure can be thus generated (3D lithography) in a single step. A local characterization of the generated patterns is performed by high-resolution transmission electron microscopy and UV-vis localized surface plasmon resonance microspectroscopy. This characterization confirms the presence of crystalline nanoparticles and aggregates.
The zero field self-organization of cobalt/surfactant nanocomposite thin films
2009
Cobalt nanostructures have been prepared by a chemical route based on the Co(II) reduction in the confined space of cobalt bis(2-ethylhexyl)sulfosuccinate (Co(DEHSS)(2)) reverse micelles dispersed in n-heptane. This procedure involves the rapid formation of surfactant softly coated Co nanostructures followed by a slow separation process of the magnetic-field responsive Co/surfactant nanocomposites from the liquid phase. The detailed structure of thin films of the Co/surfactant nanocomposites has been investigated by scanning force microscopy (SFM). The thin films were characterized by different anisotropic features. Micrometric long domains of self-aligned ellipsoidal NPs (tens of nanometer…
One-step growth of isolated CdO nanoparticles on r-sapphire substrates by using the spray pyrolysis methodology
2014
In spite of the remarkable properties of CdO, there are only a few reports on CdO nanostructures, especially on isolated NPs. In this paper, we analyze the growth of isolated CdO nanoparticles (NPs) on 0.5° miscut r-sapphire substrates by using the spray pyrolysis methodology in its classical configuration. A systematic study has been performed to optimize the growth parameters such as precursor concentration, growth time, spray rate and growth temperature to obtain CdO NPs (size: 6–10 nm to 35–100 nm depending on the growth conditions). The study shows the control over the size and density of the CdO nanoparticles that can be achieved by adjusting the growth parameters. The CdO nanoparticl…