Cold Stage Scanning Electron Microscopy of Bentonite Suspensions

1980 ◽  
Vol 38 ◽  
pp. 206-207
Author(s):  
S. A. Jenekhe ◽  
H. T. Davis ◽  
L. E. Scriven
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Structural Changes ◽  
Bentonite Clay ◽  
Mineral Particles ◽  
Cold Stage ◽  
Clay Suspensions ◽  
Stage Scanning ◽  
Electrically Charged ◽  
Scanning Electron

Aqueous suspensions of clay mineral particles evidently form gels owing to interactions between the electrically charged particles. It is generally accepted that physical properties of a suspension, especially rheological properties, reflect its microstructure and that deformation brings about structural changes (1) We have applied fast-freeze cold-stage scanning electron microscopy to visualize the microstructures of bentonite clay suspensions of known shear history.

Application of Scanning Electron Microscopy for the Purposes of Mineralized Wood Survey

2014 ◽  
Vol 1000 ◽  
pp. 251-256 ◽  
Author(s):  
Tereza Murínová ◽  
Miroslava Mamoňová ◽  
Pavel Mec ◽  
Jana Daňková ◽  
Petr Rezek
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
Chemical Modification ◽  
Structural Changes ◽  
Natural Process ◽  
Sem Images ◽  
Mineral Particles ◽  
Scanning Electron

Wooden mineralization is a familiar term that indicates mainly natural process during which chemical changes of the material arise by specific conditions and mineral particles remain in the lumen of wooden cells or penetrate into the cell wall, where they can bind with some components. This principle can be also used for chemical modification for the purpose of extending the life of wooden elements. This study was focused on the survey of artificial mineralized wood by scanning electron microscopy (SEM). Evaluation of the SEM images aimed at structural changes of wood and localization of mineral particles is the key knowledge, which can serve for the determination of mineralization extent.

scholarly journals Redox Mechanism of Azathioprine and Its Interaction with DNA

2021 ◽  
Vol 22 (13) ◽  
pp. 6805
Author(s):  
Mihaela-Cristina Bunea ◽  
Victor-Constantin Diculescu ◽  
Monica Enculescu ◽  
Horia Iovu ◽  
Teodor Adrian Enache
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Scanning Electron Microscopy ◽  
Structural Changes ◽  
Differential Pulse ◽  
Immunosuppressive Drug ◽  
Redox Mechanism ◽  
Before And After ◽  
Dna Film ◽  
Scanning Electron

The electrochemical behavior and the interaction of the immunosuppressive drug azathioprine (AZA) with deoxyribonucleic acid (DNA) were investigated using voltammetric techniques, mass spectrometry (MS), and scanning electron microscopy (SEM). The redox mechanism of AZA on glassy carbon (GC) was investigated using cyclic and differential pulse (DP) voltammetry. It was proven that the electroactive center of AZA is the nitro group and its reduction mechanism is a diffusion-controlled process, which occurs in consecutive steps with formation of electroactive products and involves the transfer of electrons and protons. A redox mechanism was proposed and the interaction of AZA with DNA was also investigated. Morphological characterization of the DNA film on the electrode surface before and after interaction with AZA was performed using scanning electron microscopy. An electrochemical DNA biosensor was employed to study the interactions between AZA and DNA with different concentrations, incubation times, and applied potential values. It was shown that the reduction of AZA molecules bound to the DNA layer induces structural changes of the DNA double strands and oxidative damage, which were recognized through the occurrence of the 8-oxo-deoxyguanosine oxidation peak. Mass spectrometry investigation of the DNA film before and after interaction with AZA also demonstrated the formation of AZA adducts with purine bases.

Light and Scanning Electron Microscopy of Human Spinal Ligaments

1985 ◽  
Vol 55 ◽  
Author(s):  
L.-H. Yahia ◽  
G. Drouin ◽  
C.-H. Rivard
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Connective Tissue ◽  
Idiopathic Scoliosis ◽  
Blood Vessels ◽  
Structural Changes ◽  
Loose Connective Tissue ◽  
Morphological Studies ◽  
Spinal Ligaments ◽  
Scanning Electron

ABSTRACTSpinal ligaments were obtained from normal and scoliotic individuals. Detailed morphological studies were carried out on the yellow, interspinous and supraspinous ligaments by light and scanning electron microscopy. Normal yellow ligaments are mostly constituted of dense elastin fibers with only a few collagen fibers and sparse blood vessels, while in normal interspinous and supraspinous ligaments, the presence of collagen is highly dominant. In the latter structures, the collagen fascicles are characterized by a regular waviness morphology. The fibrils constituting the fascicles appear either parallel or helical with respect to the fascicle axis. Structural changes are observed in the spinal ligaments of patients with congenital as well as idiopathic scoliosis. For yellow ligaments, only slight differences are found between normal and scoliotic specimens. However, alterations in collagen waviness and architecture are observed mainly in the supraspinous ligaments and to a lesser extent in the interspinous ligaments. In addition, increases in the cellularity, loose connective tissue and vessels are found in both forgoing ligaments. These results indicate that the more pronounced scoliosis-related changes occur in ligaments having the farthest distance from the axis of flexion-rotation.

scholarly journals Effects of Droplet-Vitrification Cryopreservation Based on Physiological and Antioxidant Enzyme Activities ofBrassidiumShooting Star Orchid

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Safrina Rahmah ◽  
Safiah Ahmad Mubbarakh ◽  
Khor Soo Ping ◽  
Sreeramanan Subramaniam
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Liquid Nitrogen ◽  
Enzyme Activities ◽  
Structural Changes ◽  
Total Soluble Protein ◽  
Antioxidant Enzyme Activities ◽  
Droplet Vitrification ◽  
The Impact ◽  
Scanning Electron

Protocorm-like bodies (PLBs) ofBrassidiumShooting Star orchid were successfully cryopreserved using droplet-vitrification method. Vitrification based cryopreservation protocol is comprised of preculture, osmoprotection, cryoprotection, cooling, rewarming, and growth recovery and each and every step contributes to the achievement of successful cryopreservation. In order to reveal the lethal and nonlethal damage produced by cryopreservation, histological observation, scanning electron microscopy (SEM), and biochemical analysis were carried out in both cryopreserved and noncryopreserved PLBs ofBrassidiumShooting Star orchid comparing with the control PLBs stock culture. Histological and scanning electron microscopy analyses displayed structural changes in cryopreserved PLBs due to the impact of cryoinjury during exposure to liquid nitrogen. Total soluble protein significantly increased throughout the dehydration process and the highest value was achieved when PLBs were stored in liquid nitrogen. Ascorbate peroxidase (APX) and catalase (CAT) showed the highest enzyme activities in both dehydration and cryostorage treatments indicating that stress level of PLBs was high during these stages.

scholarly journals Study of selection and purification of Brazilian bentonite clay by elutriation: a XRF, SEM and Rietveld analysis

Cerâmica ◽  
2016 ◽  
Vol 62 (361) ◽  
pp. 1-8 ◽  
Author(s):  
J. L. Alves ◽  
A. E. Zanini ◽  
M. E. de Souza ◽  
M. L. F. Nascimento
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Rietveld Method ◽  
Bentonite Clay ◽  
Rietveld Analysis ◽  
Industrial Applications ◽  
X Ray Diffraction ◽  
X Ray ◽  
Almost All ◽  
Scanning Electron

Abstract Clays obtained from nature have a lot of impurities. Therefore, for best using of these materials, it is necessary its selection and purification. Thus, the aim of this work is to separate and to purify the smectite fractions using water as a solvent at a low flux mixed with a bentonite clay extracted from a mine in Vitória da Conquista - Bahia / Brazil. For this a separation method of fractions of expandable clays based on the Stokes' Law was applied - this process is called elutriation, in order to ensure and to expand possible industrial applications of this material. The samples were characterized by analysis of X-ray diffraction, X-ray fluorescence and scanning electron microscopy. The Rietveld method enabled the quantification of main phase minerals: montmorillonite, kaolinite, nontronite and quartz, reaching 85% in mass of montmorillonite phase at the end of the process. Results showed that the method used was efficient to remove almost all quartz, carbonates and organic matter from the sample. It was also observed a monomodal grain size distribution of elutriated materials with thinner grains, around (18.1 ± 1.8) μm at the end of the process. It has been concluded that the method developed and applied showed promising characters to be applied to elutriate kilograms of clays and could be used in industrial scale.

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