scholarly journals Microstructural changes of polyacrylonitrile-based carbon fibers (T300 and T700) due to isothermal oxidation (1): focusing on morphological changes using scanning electron microscopy

2016 ◽  
Vol 18 ◽  
pp. 18-23 ◽  
Author(s):  
Seong-Moon Oh ◽  
Sang-Min Lee ◽  
Dong-Su Kang ◽  
Jae-Seung Roh
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbon Fibers ◽  
Morphological Changes ◽  
Isothermal Oxidation ◽  
Microstructural Changes ◽  
Scanning Electron

Field-Emission Scanning Electron Microscopy and Energy-Dispersive X-Ray Analysis to Understand the Role of Tannin-Based Dyes in the Degradation of Historical Wool Textiles

2014 ◽  
Vol 20 (5) ◽  
pp. 1534-1543 ◽  
Author(s):  
Annalaura Restivo ◽  
Ilaria Degano ◽  
Erika Ribechini ◽  
Josefina Pérez-Arantegui ◽  
Maria Perla Colombini
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Elemental Composition ◽  
Field Emission ◽  
Cross Sections ◽  
Morphological Changes ◽  
Energy Dispersive ◽  
X Ray ◽  
Edx Analysis ◽  
Scanning Electron

Abstract:An innovative approach, combining field-emission scanning electron microscopy (FESEM) with energy dispersive X-ray spectroscopy (EDX) analysis, is presented to investigate the degradation mechanisms affecting tannin-dyed wool. In fact, tannin-dyed textiles are more sensitive to degradation then those dyed with other dyestuffs, even in the same conservation conditions.FESEM-EDX was first used to study a set of 48 wool specimens (artificially aged) dyed with several raw materials and mordants, and prepared according to historical dyeing recipes. EDX analysis was performed on the surface of wool threads and on their cross-sections. In addition, in order to validate the model formulated by the analysis of reference materials, several samples collected from historical and archaeological textiles were subjected to FESEM-EDX analysis.FESEM-EDX investigations enabled us to reveal the correlation between elemental composition and morphological changes. In addition, aging processes were clarified by studying changes in the elemental composition of wool from the protective cuticle to the fiber core in cross-sections. Morphological and elemental analysis of wool specimens and of archaeological and historical textiles showed that the presence of tannins increases wool damage, primarily by causing a sulfur decrease and fiber oxidation.

scholarly journals Rapid induction of morphological changes in human carcinoma cells A-431 by epidermal growth factors.

1979 ◽  
Vol 83 (1) ◽  
pp. 260-265 ◽  
Author(s):  
M Chinkers ◽  
J A McKanna ◽  
S Cohen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Growth Factors ◽  
Morphological Changes ◽  
Carcinoma Cells ◽  
Human Carcinoma ◽  
Rapid Induction ◽  
Epidermal Growth ◽  
Scanning Electron

The morphological effects of epidermal growth factor (EGF) on human carcinoma cells A-431 have been examined by scanning electron microscopy. These flat polygonal cells normally exhibit only small membrane folds, but show extensive ruffling and extension of filopodia within 5 min of exposure to EGF at 37 degrees C. This ruffling activity is transient, subsiding within another 5--15 min, but several other changes in surface morphology follow. Within the first hour of exposure to the hormone, the cell surface becomes exceedingly smooth and the nuclei seem to protrude above the plane of the otherwise thin monolayer, giving the cells a "fried egg" appearance. Cells at the edges of colonies gradually retract from the substrate, leading to reorganization, by 12 h, of the monolayer into multilayered colonies. EGF thus induces both rapid and long-term alterations in the morphology of these epidermoid cells.

A comparison of scolex morphology between the plerocercoid and the adult of Calliobothrium verticillatum (Tetraphyllidea: Onchobothriidae)

1991 ◽  
Vol 69 (6) ◽  
pp. 1484-1488 ◽  
Author(s):  
J. N. Caira ◽  
T. R. Ruhnke
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hermit Crab ◽  
Morphological Changes ◽  
Complex Surface ◽  
Apical Region ◽  
Apical Sucker ◽  
Mustelus Canis ◽  
Scanning Electron ◽  
Surface Changes

The morphological changes associated with the ontogenetic transformation of the scolex from larva to adult were investigated in the tapeworm Calliobothrium verticillatum (Rudolphi, 1819) van Beneden, 1850 by comparing the morphology of plerocercoids collected from the hermit crab Pagurus pollicaris Say, 1817 with that of adult worms collected from the shark Mustelus canis (Mitchell, 1815), using scanning electron microscopy. The apex of the scolex in young plerocercoids bore a conspicuous sucker. Each bothridium was flat and divided into four regions: an anterior oval region with two marginal bumps, and three posterior loculi clearly marked by two costae. The microthrix pattern was not determined for very young plerocercoids. The most conspicuous feature of older plerocercoids was the sucker on the apex of the scolex. The bothridia were concave, and each bore an apical region subdivided into three shallow suckers and three conspicuous loculi. Densely packed blade-like microtriches intermingled with filiform microtriches were visible on all surfaces of the scolex except the surface directly adjacent to the opening of the apical sucker of the scolex, which was entirely devoid of microtriches, and the proximal surfaces of the bothridia, which had only blade-like microtriches. The apical sucker was absent from the scolex adult specimens. The only remnant of this structure was a small knob on the apex of the scolex. The bothridia were concave and bore, from anterior to posterior, three conspicuous apical suckers arranged in a horizontal row adjacent to one another, two pairs of single-pronged hooks, and three conspicuous loculi. Densely packed blade-like microtriches were present on all proximal surfaces of the scolex. Microtriches were not present on the distal surfaces of the apical suckers of the bothridia, on the hooks, or on the distal surfaces of the loculi of the bothridia. The latter regions were covered with very small, round structures. The differences in the microthrix components of the various surfaces of the scolex between the plerocercoid and the adult suggest that complex surface changes occur during this phase of ontogeny. Comparison of the development of this species with that of other onchobothriids suggests that, in general, the number of loculi to be expected in the plerocercoid of an onchobothriid is one plus the number of posthook loculi in the adult.

Morphological Changes in Gill Epithelia of Heat-Stressed Rainbow Trout, Salmo gairdneri: Evidence in Support of a Temperature-Induced Surface Area Change Hypothesis

1981 ◽  
Vol 38 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Dan Jacobs ◽  
Edward F. Esmond ◽  
Edward L. Melisky ◽  
Charles H. Hocutt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Rainbow Trout ◽  
Morphological Changes ◽  
Salmo Gairdneri ◽  
Mucus Production ◽  
Secondary Lamellae ◽  
Gill Structure ◽  
Surface Area Change ◽  
Scanning Electron

Surface morphology of the gill structure of hatchery-reared rainbow trout (Salmo gairdneri) exposed to heat shock was examined by scanning electron microscopy. Changes were greatest in fish previously acclimated to 6 °C and exposed to 24 or 30 °C water for 3–5 d. Gill epithelia of heat-stressed fish showed a reduction and loss of the microridge patterns. The surface of the efferent arterial sides of the primary lamellae became irregular and rugose, and fusion of the secondary lamellae occurred at higher temperatures. The morphological changes along with an increase in mucus production may be a major factor in causing hypoxia in heat-stressed fish.Key words: gill epithelium, rainbow trout, primary lamellae, secondary lamellae, temperature, heat stress, scanning electron microscopy

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