Method of platinum-carbon coating of ultrathin sections for transmission and scanning electron microscopy: An application for study of biological composites

2003 ◽  
Vol 62 (3) ◽  
pp. 218-224 ◽  
Author(s):  
H. Schwarz ◽  
S. Gorb
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbon Coating ◽  
Biological Composites ◽  
Ultrathin Sections ◽  
Scanning Electron

Purification of SWNTs Using Microwave Heating

2001 ◽  
Vol 706 ◽  
Author(s):  
Avetik R. Harutyunyan ◽  
Bhabendra K. Pradhan ◽  
Gamini U. Sumanasekera ◽  
Jiping Chang ◽  
Gugang Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Microwave Heating ◽  
Acid Treatment ◽  
Carbon Coating ◽  
Single Wall Carbon Nanotubes ◽  
Metal Catalyst ◽  
Thermo Gravimetric ◽  
Mild Acid ◽  
Scanning Electron

AbstractA new method for purifying single wall carbon nanotubes (SWNTs) using microwave heating is developed. The microwaves couple to the residual metal catalyst, raising significantly the local temperature leading to both the oxidation and rupturing of the carbon passivation layer over the metal catalyst particles and sintering. With this protective carbon coating weakened or removed, a mild acid treatment in HCl is then sufficient to remove most of the metal in the sample, leaving the nanotubes in tact. Results from transmission and scanning electron microscopy (TEM & SEM), Raman spectroscopy and thermo-gravimetric studies are discussed.

EM of associated spermatozoa of squirrel (Funambulus pennanti)

1992 ◽  
Vol 50 (1) ◽  
pp. 624-625
Author(s):  
S. R. Bawa ◽  
H. K. Bains
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Freeze Fracture ◽  
Invertebrate Animals ◽  
Ultrathin Sections ◽  
Conventional Manner ◽  
Scanning Electron

Associations amongst spermatozoa have been reported in a variety of vertebrate and invertebrate animals. Spermatozoa come together and are attached to each other only in the region of the head, their tails are free – required to steer the spermatozoa. We have studied sperm-sperm association in squirrel using electron microscopy.Small pieces of epididymides of adult squirrels (Funambulus pennanti) were fixed in cacodylate buffered glutaraldehyde and processed in a conventional manner for transmission and scanning electron microscopy Ultrathin sections and freeze-fracture replicas were examined with JEOL 1200 EX electron microscope.

Application of high-pressure scanning electron microscopy (ECO-SEM) in forensic sample analysis

1996 ◽  
Vol 54 ◽  
pp. 848-849
Author(s):  
Thomas A. Kubic ◽  
JoAnn Buscaglia
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Pressure ◽  
Carbon Coating ◽  
High Vacuum ◽  
Controlled Environment ◽  
Sample Analysis ◽  
Sample Chamber ◽  
Forensic Sample ◽  
Scanning Electron

Traditionally to obtain satisfactory images and reasonable resolution with a Scanning Electron Microscope (SEM), it has been necessary to employ a high vacuum within the sample chamber.High vacuum can result in the dehydration of materials with an alteration of sample morphology and in some cases the introduction of artifacts. In such an environment, samples that are nonconductive experience extensive charging with image degradation. Samples of forensic concern, such as textile bundles or swatches, exhibit this problem even after the application of metal coating. The problem is even more pronounced when carbon coating is used, as is often the preference of forensic microscopists in order to simplify interpretation of the EDX spectra.The commercial availability of "high pressure" or controlled environment SEMs that operate with sample chamber pressures from 50 to 4000 millitorr, while the electron guns and columns are kept at high vacuum conditions have solved these problems. The presence of this "higher" pressure retards dehydration while charging effects are nearly eliminated.

scholarly journals Scanning electron microscopy of murine skin ultrathin sections and cultured keratinocytes

2021 ◽  
Vol 2 (3) ◽  
pp. 100729
Author(s):  
Avinanda Banerjee ◽  
Ritusree Biswas ◽  
Ryan Lim ◽  
Hilda Amalia Pasolli ◽  
Srikala Raghavan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cultured Keratinocytes ◽  
Ultrathin Sections ◽  
Scanning Electron

Ultrastructure of oospore development in Albugo candida on rapeseed

1977 ◽  
Vol 55 (17) ◽  
pp. 2348-2357 ◽  
Author(s):  
J. P. Tewari ◽  
W. P. Skoropad
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Brassica Campestris ◽  
Active Role ◽  
Albugo Candida ◽  
Transmission Electron ◽  
Ultrathin Sections ◽  
Scanning Electron

The structure and development of oospores of Albugo candida in the stagheads in rapeseed (Brassica campestris) were investigated by light microscopy, transmission electron microscopy of ultrathin sections, and scanning electron microscopy. Development of an oospore, in general, is similar to that in Pythium. A reaction zone is formed in the oogonial wall at the point of contact by the fertilization tube of the antheridium. The oospore has a highly differentiated five-layered cell wall. The periplasm appears to play an active role in deposition of the cell wall of the oospore. Contents of the periplasm do not disappear after maturation of the oospore; instead, they forma persistent material between it and the oogonial wall. Hence, functionally, the oospore wall complex has two additional layers. Longevity of the oospore may be due to the heavily fortified cell wall.

Observation d'un sol forestier (rendzine) en microscopie electronique

1979 ◽  
Vol 25 (8) ◽  
pp. 943-946 ◽  
Author(s):  
G. Kilbertus ◽  
J. Proth
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Forest Soil ◽  
Clay Minerals ◽  
The Other ◽  
Soil Suspension ◽  
Microscopie Électronique ◽  
Fungal Hyphae ◽  
Ultrathin Sections ◽  
Scanning Electron

Scanning electron microscopy was used to evidence the aggregated structure of a forest soil as well as the presence of fungal hyphae external to soil aggregates.The supernatant of soil suspension in water mainly contained isolated bacteria, while ultrathin sections of aggregates frequently revealed groups of bacteria surrounded by a sheath of mucilage with adhering clay minerals on the outside.These results confirm the existence of two particular biotopes in the soil studied: one is located inside aggregates, and the other, in the inter-aggregate spaces. [Translated by the journal]

OsO4-tannin-OsO4 method for transmission and scanning electron microscopy of biological specimens

1978 ◽  
Vol 36 (2) ◽  
pp. 56-57
Author(s):  
Gen Takahashi
Keyword(s):  
Electron Microscopy ◽  
Heavy Metal ◽  
Scanning Electron Microscopy ◽  
Electron Bombardment ◽  
High Magnification ◽  
Transmission Electron ◽  
Cacodylate Buffer ◽  
Ultrathin Sections ◽  
Intense Electron ◽  
Scanning Electron

Tissue blocks or slices about 1 mm in thickness were treated according to the following procedures both for transmission electron microscopy(SEM) and for scanning electron microscopy(SEM).[A] Primary Osmication(Fixation): 2%0s04 in 0.1 M Na-cacodylate buffer or Millo- nig's phosphate buffer(pH7.4) for 2 hrs at 4°C.[B] Postfixation and Mordanting: 2-4 % tannic acid—8(2-16)%glutaraldehyde in the buffer(pH6.8-7.0),for 1-40 hrs at 4°C.[C] Secondary Osmication(Staining): 2 %0s04 in the buffer(pH7.4)for 2 hrs at 4°C. Specimens after step C were rapidly dehydrated and embedded in Epon. Ultrathin sections were cut with diamond knives. Although sections without heavy metal staining could be observed with moderate contrast, they were stained briefly with lead solution for high magnification, because of sublimation of osmium by intense electron bombardment.

Fertilization Membranes and Sea Urchin Embryos Studied by Scanning Electron Microscopy

1971 ◽  
Vol 29 ◽  
pp. 530-531
Author(s):  
Walter J. Humphreys ◽  
David T. Lindsay
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Sea Urchin ◽  
Structural Features ◽  
Vitelline Membrane ◽  
Cortical Granules ◽  
Freeze Dried ◽  
Fertilization Membrane ◽  
Ultrathin Sections ◽  
Scanning Electron

Scanning electron microscopy (SEM) of specimens freeze-dried after fixation in Parducz fixative and ultrathin sections of the sea urchin, Strongylocentrotus purpuratus show that the egg is covered by many papillae about 0.25μ in diameter and 0.5μ long (Fig. 1a). When the vitelline layer lifts away from the surface of the egg at the time of fertilization it has many uniformly spaced protrusions that persist as prominent and consistent structural features of the fertilization membrane, which forms when material from ruptured cortical granules is added to the inner surface of the raised vitelline membrane. Dimensions of the protrusions, their spacing on the membrane, and their projection in a direction outward from the egg (Fig. 1b) suggests that they originate when the vitelline layer lifts away from the egg surface in the form of a somewhat distorted and expanded replica of the papillae-bearing surface of the unfertilized egg.

Effect of Vinblastine Sulfate on Visceral Epithelial Cells of Rat Renal Corpuscle (Scanning Electron Microscopy)

1976 ◽  
Vol 34 ◽  
pp. 60-61
Author(s):  
G. E. Tyson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Epithelial Cells ◽  
Renal Tissue ◽  
Renal Corpuscle ◽  
Intravenous Injections ◽  
Transmission Electron ◽  
Ultrathin Sections ◽  
Vinblastine Sulfate ◽  
Scanning Electron

Visceral epithelial cells (podocytes) of the rat renal corpuscle are highly branched -in shape (1-3) and contain numerous cytoplasmic microtubules (4). In a previous study of podocytes by Tyson and Bulger (4), microtubule loss was induced by intravenous injections of vinblastine sulfate, and then renal tissue was examined by routine transmission electron microscopy. With a vinblastine treatment that resulted in nearly complete absence of microtubules in podocytes, examination of ultrathin sections yielded no evidence that loss of microtubules was accompanied by a change in cell shape. Similar experiments, described below, have now been performed using scanning electron microscopy, in order to facilitate recognition of subtle shape changes that would not be readily apparent in sectioned material.

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