ETUDE COMPARATIVE DE LA DURETE DU BLE DE PRINTEMPS LAVAL-19 ET DES BLES Triticum aestivum

1982 ◽  
Vol 62 (1) ◽  
pp. 19-27
Author(s):  
L. KAMARA ◽  
A. BOUDREAU ◽  
F. CASTAIGNE
Keyword(s):  
Triticum Aestivum ◽  
Electron Microscope ◽  
Spring Wheat ◽  
Starch Granule ◽  
Starch Granules ◽  
Protein Matrix ◽  
Thin Sections ◽  
Air Space ◽  
Packed Structure ◽  
Scanning Electron

The examination of ultra-thin sections by the scanning electron microscope was performed comparing spring wheat Laval-19 with several types of wheat of increasing hardness (Yorkstar, Concorde and Neepawa) using both whole kernels and the corresponding flours. The hardness properties of each type of wheat was determined using an Instron Tensile Testor. In hard wheats, we observed a tightly packed structure showing little or no air space in the endosperm. The adhesion between proteins and starch granules was strong enough to break the starch granule rather than to separate at the interface. The soft wheats appeared to have a much looser structure with many intergranular air spaces and no broken starch granules. The microscopy of the flours illustrated the integrity of the starch-protein matrix in the hard flours and a mixture of free starch granules, free protein, and small aggregates of protein and starch in soft flours. The Instron measurements were in agreement with the microscopic examination and both techniques indicated clearly the differences in hardness between soft and hard, leaving the spring wheat Laval-19 a type of wheat intermediary between soft and hard.

SEM Examination of a Used Diamond Knife

1971 ◽  
Vol 29 ◽  
pp. 452-453
Author(s):  
J. Temple Black
Keyword(s):  
Electron Microscope ◽  
High Voltage ◽  
High Magnification ◽  
Metallic Materials ◽  
Wide Spread ◽  
Thin Sections ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Scanning Electron ◽  
Diamond Knife

Since its introduction by Fernandez-Moran, the diamond knife has gained wide spread usage as a common material for cutting of thin sections of biological and metallic materials into thin films for examination in the transmission electron microscope. With the development of high voltage E.M. and scanning transmission E.M., microtomy applications will become increasingly important in the preparation of specimens. For those who can afford it, the diamond knife will thus continue to be an important tool to accomplish this effort until a cheaper but equally strong and sharp tool is found to replace the diamond, glass not withstanding.In Figs. 1 thru 3, a first attempt was made to examine the edge of a used (β=45°) diamond knife by means of the scanning electron microscope. Because diamond is conductive, first examination was tried without any coating of the diamond. However, the contamination at the edge caused severe charging during imaging. Next, a thin layer of carbon was deposited but charging was still extensive at high magnification - high voltage settings. Finally, the knife was given a light coating of gold-palladium which eliminated the charging and allowed high magnification micrographs to be made with reasonable resolution.

Observations of thick and thin sections in a field-emission SEM

1994 ◽  
Vol 52 ◽  
pp. 1018-1019
Author(s):  
W. P. Wergin ◽  
S. Roy ◽  
E. F. Erbe ◽  
C. A. Murphy ◽  
C. D. Pooley
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Chemical Fixation ◽  
Thin Sections ◽  
Transmission Electron ◽  
Conventional Transmission Electron Microscope ◽  
Scanning Electron

Larvae of the nematode, Steinernema carpocapsae Weiser strain All, were cryofixed and freezesubstituted for 3 days in acetone containing 2% osmium tetroxide according to established procedures. Following chemical fixation, the nematodes were brought to room temperature, embedded in Spurr's medium and sectioned for observation with a Hitachi S-4100 field emission scanning electron microscope that was equipped with an Oxford CT 1500 Cryotrans System. Thin sections, about 80 nm thick, similar to those generally used in conventional transmission electron microscope (TEM) studies were mounted on copper grids and stained with uranyl acetate for 30 min and lead citrate for 5 min. Sections about 2 μm thick were also mounted and stained in a similar fashion. The grids were mounted on an Oxford grid holder, inserted into the microscope and onto a cryostage that was operated at ambient temperature. Thick and thin sections of the larvae were evaluated and photographed in the SEM at different accelerating voltages. Figs. 4 and 5 have undergone contrast conversion so that the images would resemble transmitted electron micrographs obtained with a TEM.

Production and Characterization of Porous Starch Granule and Poly(butylene adipate-co-terephthalate) Blend as a Bio-Composite

2012 ◽  
Vol 550-553 ◽  
pp. 1513-1521
Author(s):  
Sirirat Thothong ◽  
Klanarong Sriroth ◽  
Rattana Tantatherdtam ◽  
Amnat Jarerat
Keyword(s):  
Starch Granule ◽  
Rice Starch ◽  
Starch Granules ◽  
Screw Extruder ◽  
Elongation At Break ◽  
Single Screw ◽  
Single Screw Extruder ◽  
Scanning Electron ◽  
Granular Starch

To improve the miscibility of native rice starch granules and poly(butylene adipate-co-terephthalate)(PBAT), rice starch was hydrolyzed by a mixture of α-amylase and amyloglucosidase. The obtained porous rice granular starch was then mechanically blended with PBAT by single screw extruder. Many pits and holes on the surface of starch granules were observed by scanning electron microscopy (SEM). The rough surface of the rice starch granules improved the compatibility of the polymers in the blends, which consequently increased the tensile strength and the elongation at break. In addition, SEM also revealed that the porous granules were homogeneously distributed in the polymer matrix with no appearance of gaps.

scholarly journals USE OF FORMALDEHYDE TO REGULATE DIGESTION OF BARLEY STARCH

1990 ◽  
Vol 70 (2) ◽  
pp. 581-589 ◽  
Author(s):  
T. A. McALLISTER ◽  
K.-J. CHENG ◽  
L. M. RODE ◽  
J. G. BUCHANAN-SMITH
Keyword(s):  
Volatile Fatty Acids ◽  
Rumen Bacteria ◽  
Starch Granules ◽  
Endosperm Cell ◽  
Starch Digestion ◽  
Protein Matrix ◽  
Fermentation Efficiency ◽  
Formaldehyde Treatment ◽  
Scanning Electron ◽  
Anaerobic Media

This study was conducted to determine the effect of formaldehyde treatment of barley on the rate of microbial starch digestion. Ground barley was left untreated (UB) or treated with 0.5% formaldehyde (TB) and incubated in vials with an inoculum consisting of a homogenate of rumen contents and Bryant's anaerobic media (1:1). Separate vials were analyzed for starch, ammonia, pH and volatile fatty acids (VFA) after 0, 4, 8, 12, 18, 24, 36 and 48 h. The digestion of starch was lower (P < 0.05) in TB than in UB between 4 and 24 h. Accumulation of NH3 was lower and pH was higher in TB vials (P < 0.05) than in UB vials. VFA production and fermentation efficiency were lower (P < 0.05) in TB than in UB. Formaldehyde treatment of barley reduced (P < 0.05) the production of propionate and enhanced (P < 0.05) the production of butyrate in comparison with UB. Examination by scanning electron microscopy (SEM) showed that the initial colonization of TB was inhibited in comparison with that of UB. The distinct shape of the endosperm cells of TB (12 h) were readily recognizable, but the endosperm cells of UB (12 h) were not readily distinguishable. SEM of TB (24 h) showed that the protein matrix of the endosperm cell is resistant to microbial digestion. The formaldehyde-induced reduction in starch digestion appears to result from the protein matrix inhibiting the access of bacteria to underlying starch granules. Key words: Starch, rumen bacteria, formaldehyde, barley

Susceptibility of Various Starch Granules to Amylases as Seen by Scanning Electron Microscope

1978 ◽  
Vol 30 (6) ◽  
pp. 186-191 ◽  
Author(s):  
H. Fuwa ◽  
Y. Sugimoto ◽  
M. Tanaka ◽  
D. V. Glover
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Starch Granules ◽  
Scanning Electron

starch grains in macerated cells

IAWA Journal ◽  
2014 ◽  
Vol 35 (2) ◽  
pp. 155-157
Author(s):  
Vinay R. Patel ◽  
Karumanchi S. Rao
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Crucial Role ◽  
Grain Shape ◽  
Cell Cytoplasm ◽  
Thin Sections ◽  
Starch Grains ◽  
Microscope Images ◽  
Starch Grain ◽  
Scanning Electron

A modified Jeffrey’s method for localization of starch grains in wood samples macerated between 15–25 °C is described here. Time and temperature played a crucial role in maintaining starch grain shape in cell cytoplasm. Starch grain shape in macerated xylem cells was confirmed by comparison with scanning electron microscope images and thin sections (10 to 15 μm thick) from the same wood samples.

Helicoidal-Rounded-Hole Microstructure of Mature Shankbone

2011 ◽  
Vol 460-461 ◽  
pp. 652-655
Author(s):  
Bin Chen ◽  
Ji Luo ◽  
Quan Yuan
Keyword(s):  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Protein Matrix ◽  
Pullout Force ◽  
Sem Observation ◽  
Collagen Protein ◽  
Scanning Electron

Scanning electron microscope (SEM) observation on a mature shankbone shows that the bone is a kind of bioceramic composite consisting of hydroxyapatite sheets and collagen protein matrix. The observation also shows that there are many holes in the bone and that the hydroxyapatite sheets near by these holes helicoidally round these holes forming a kind of helicoidally-rounded-hole microstructure (HRHM). The maximum pullout force of the HRHM is investigated and compared with that of non-helicoidally-rounded-hole microstructure (NHRHM). It shows that the HRHM could markedly increase the maximum pullout force of the hydroxyapatite sheets compared to the NHRHM and therefore enhance the fracture toughness of the bone.

Ultrastructural study of experimental duodenal ulcer in a new animal model

1992 ◽  
Vol 50 (1) ◽  
pp. 614-615
Author(s):  
H.X. Bui ◽  
A. delRosario ◽  
M. Abdulla ◽  
F. Ballouk ◽  
V. Bajakian ◽  
...  
Keyword(s):  
Duodenal Ulcer ◽  
Electron Microscope ◽  
Gastric Ulcers ◽  
Ultrastructural Changes ◽  
Sprague Dawley ◽  
Polyethylene Tube ◽  
Duodenal Ulcers ◽  
Thin Sections ◽  
Experimental Duodenal Ulcer ◽  
Scanning Electron

Various animal models have often been utilized as the basis of studies of the pathophysiology of peptic ulcer disease, however the ultrastructural changes in the evolution of duodenal ulcers produced in experimental animals have not been well elucidated. Utilizing a surgical method developed for the study of gastric ulcers we have established an experimental duodenal ulcer production technique in the rat which is highly reproducible and readily standardized. In the following time sequence study of experimental duodenal ulcers we present the ultrastructural features of ulcer induction and evolution.Duodenal ulcers were produced in 150-200 gram male Sprague Dawley rats by application of 50% acetic acid for 30 seconds through a 3 mm polyethylene tube to the serosa 1.0-1.5 cm distal to the pyloric sphincter. Routine transmission and scanning electron microscopy were performed on duodenal specimens at specific time points subsequent to surgical ulcer generation. Thin sections were stained with uranyl acetate and lead citrate and examined with a Phillip's EM 300 transmission electron microscope. For SEM, specimens were post-fixed in 2% osmium for two days, coated with gold/palladium and examined with JEOL JSM-6100 scanning electron microscope (JEOL, Inc., Peabody, MA).

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