Core−Shell Structures of Silica−Organic Pigment Nanohybrids Visualized by Electron Spectroscopic Imaging

2009 ◽  
Vol 1 (5) ◽  
pp. 977-981 ◽  
Author(s):  
Shin Horiuchi ◽  
Shinji Horie ◽  
Kunihiro Ichimura
Keyword(s):  
Spectroscopic Imaging ◽  
Shell Structures ◽  
Core Shell ◽  
Electron Spectroscopic Imaging ◽  
Organic Pigment

Visualisation of E. coli ribosomal RNA in situ by electron spectroscopic imaging and image averaging

1992 ◽  
Vol 50 (1) ◽  
pp. 466-467
Author(s):  
Daniel Beniac ◽  
George Harauz
Keyword(s):  
Ribosomal Rna ◽  
Three Dimensional ◽  
Spectroscopic Imaging ◽  
Electron Spectroscopic Imaging ◽  
E Coli ◽  
Microscopical Technique ◽  
Quantitative Image ◽  
Dimensional Reconstruction ◽  
Image Averaging ◽  
Protein Components

The structures of E. coli ribosomes have been extensively probed by electron microscopy of negatively stained and frozen hydrated preparations. Coupled with quantitative image analysis and three dimensional reconstruction, such approaches are worthwhile in defining size, shape, and quaternary organisation. The important question of how the nucleic acid and protein components are arranged with respect to each other remains difficult to answer, however. A microscopical technique that has been proposed to answer this query is electron spectroscopic imaging (ESI), in which scattered electrons with energy losses characteristic of inner shell ionisations are used to form specific elemental maps. Here, we report the use of image sorting and averaging techniques to determine the extent to which a phosphorus map of isolated ribosomal subunits can define the ribosomal RNA (rRNA) distribution within them.

Transcription factor/DNA interactions visualized by electron spectroscopic imaging

1992 ◽  
Vol 50 (1) ◽  
pp. 450-451
Author(s):  
David P. Bazett-Jones ◽  
Mark L. Brown
Keyword(s):  
Transcription Factor ◽  
Dna Sequences ◽  
Transcription Initiation ◽  
Molecular Mechanisms ◽  
Phosphorus Content ◽  
Spectroscopic Imaging ◽  
Electron Spectroscopic Imaging ◽  
Dna Backbone ◽  
Two Parameters ◽  
High Level

A multisubunit RNA polymerase enzyme is ultimately responsible for transcription initiation and elongation of RNA, but recognition of the proper start site by the enzyme is regulated by general, temporal and gene-specific trans-factors interacting at promoter and enhancer DNA sequences. To understand the molecular mechanisms which precisely regulate the transcription initiation event, it is crucial to elucidate the structure of the transcription factor/DNA complexes involved. Electron spectroscopic imaging (ESI) provides the opportunity to visualize individual DNA molecules. Enhancement of DNA contrast with ESI is accomplished by imaging with electrons that have interacted with inner shell electrons of phosphorus in the DNA backbone. Phosphorus detection at this intermediately high level of resolution (≈lnm) permits selective imaging of the DNA, to determine whether the protein factors compact, bend or wrap the DNA. Simultaneously, mass analysis and phosphorus content can be measured quantitatively, using adjacent DNA or tobacco mosaic virus (TMV) as mass and phosphorus standards. These two parameters provide stoichiometric information relating the ratios of protein:DNA content.

Localization of DNA in chromatin using ESI and osmium ammine staining

1990 ◽  
Vol 48 (3) ◽  
pp. 116-117
Author(s):  
C.L. Woodcock ◽  
R.A. Horowitz ◽  
D. P. Bazett-Jones ◽  
A.L. Olins
Keyword(s):  
Spectroscopic Imaging ◽  
Energy Losses ◽  
Electron Spectroscopic Imaging ◽  
Feulgen Reaction ◽  
Specific Location ◽  
Eukaryotic Nucleus ◽  
Chromatin Fibers ◽  
Patiria Miniata ◽  
Model Structures

In the eukaryotic nucleus, DNA is packaged into nucleosomes, and the nucleosome chain folded into ‘30nm’ chromatin fibers. A number of different model structures, each with a specific location of nucleosomal and linker DNA have been proposed for the arrangment of nucleosomes within the fiber. We are exploring two strategies for testing the models by localizing DNA within chromatin: electron spectroscopic imaging (ESI) of phosphorus atoms, and osmium ammine (OSAM) staining, a method based on the DNA-specific Feulgen reaction.Sperm were obtained from Patiria miniata (starfish), fixed in 2% GA in 150mM NaCl, 15mM HEPES pH 8.0, and embedded In Lowiciyl K11M at -55C. For OSAM staining, sections 100nm to 150nm thick were treated as described, and stereo pairs recorded at 40,000x and 100KV using a Philips CM10 TEM. (The new osmium ammine-B stain is available from Polysciences Inc). Uranyl-lead (U-Pb) staining was as described. ESI was carried out on unstained, very thin (<30 nm) beveled sections at 80KV using a Zeiss EM902. Images were recorded at 20,000x and 30,000x with median energy losses of 110eV, 120eV and 160eV, and a window of 20eV.

Designing active mats based on cellulose acetate/polycaprolactone core/shell structures with different release kinetics

2021 ◽  
Vol 261 ◽  
pp. 117849 ◽  
Author(s):  
Adrián Rojas ◽  
Eliezer Velásquez ◽  
Constanza Piña ◽  
María José Galotto ◽  
Carol López de Dicastillo
Keyword(s):  
Cellulose Acetate ◽  
Release Kinetics ◽  
Shell Structures ◽  
Core Shell

scholarly journals A SERS Study of Charge Transfer Process in Au Nanorod–MBA@Cu2O Assemblies: Effect of Length to Diameter Ratio of Au Nanorods

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 867
Author(s):  
Lin Guo ◽  
Zhu Mao ◽  
Sila Jin ◽  
Lin Zhu ◽  
Junqi Zhao ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Shell Structure ◽  
Shell Structures ◽  
Core Shell ◽  
Absorption Bands ◽  
Au Nanorods ◽  
The Core ◽  
Band Position ◽  
Surface Enhanced Raman ◽  
Core Shell Structure

Surface-enhanced Raman scattering (SERS) is a powerful tool in charge transfer (CT) process research. By analyzing the relative intensity of the characteristic bands in the bridging molecules, one can obtain detailed information about the CT between two materials. Herein, we synthesized a series of Au nanorods (NRs) with different length-to-diameter ratios (L/Ds) and used these Au NRs to prepare a series of core–shell structures with the same Cu2O thicknesses to form Au NR–4-mercaptobenzoic acid (MBA)@Cu2O core–shell structures. Surface plasmon resonance (SPR) absorption bands were adjusted by tuning the L/Ds of Au NR cores in these assemblies. SERS spectra of the core-shell structure were obtained under 633 and 785 nm laser excitations, and on the basis of the differences in the relative band strengths of these SERS spectra detected with the as-synthesized assemblies, we calculated the CT degree of the core–shell structure. We explored whether the Cu2O conduction band and valence band position and the SPR absorption band position together affect the CT process in the core–shell structure. In this work, we found that the specific surface area of the Au NRs could influence the CT process in Au NR–MBA@Cu2O core–shell structures, which has rarely been discussed before.

Template-free synthesis of ordered ZnO@ZnS core–shell arrays for high performance supercapacitors

2016 ◽  
Vol 45 (44) ◽  
pp. 17980-17986 ◽  
Author(s):  
Hailong Yan ◽  
Tong Li ◽  
Yang Lu ◽  
Jinbing Cheng ◽  
Tao Peng ◽  
...  
Keyword(s):  
High Performance ◽  
Shell Structures ◽  
Core Shell ◽  
Template Free

In this article, ordered ZnO@ZnS core–shell structures have been produced on a stainless mesh by a two-step approach without using a template.

Synthesis and characterisation of core–shell structures for orthopaedic surgery

2007 ◽  
Vol 40 (15) ◽  
pp. 3349-3353 ◽  
Author(s):  
Edina Rusen ◽  
Cătălin Zaharia ◽  
Teodora Zecheru ◽  
Bogdan Mărculescu ◽  
Robert Filmon ◽  
...  
Keyword(s):  
Orthopaedic Surgery ◽  
Shell Structures ◽  
Core Shell
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