Low-Temperature Specimen Preparations For Electron Microscopy and Their Applicability to Plant Materials

1985 ◽  
Vol 43 ◽  
pp. 616-619
Author(s):  
Richard E. Crang
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
High Water ◽  
Structural Features ◽  
High Water Content ◽  
Morphological Examination ◽  
Plant Materials ◽  
Structural Support ◽  
Means Of Transmission ◽  
Cellular Components

Progress in utilizing the technologies of low-temperature sample preparation for botanical materials in the electron microscope has notably lagged behind those of other biological specimens. To a great extent this is due to the structural features of plant materials which are frequently characterized by rigid cell walls, often with a nearly impermeable cuticle, air spaces around parenchymatous tissues, and large central vacuoles of high water content with no structural support. Freezing, or cryofixation, at its best, is capable of preserving otherwise highly labile cellular components for morphological examination by means of transmission electron microscopy. It also instantaneously stops cellular movement which may result in an unnatural distribution of cell contents and/or the formation of artifactual structures within cells. Among microorganisms, it is now believed that mesosomes in bacteria and lomasomes in many fungi may be considered artifacts caused by the slow rate of chemical fixation.

scholarly journals Initial Moisture Content of Corncobs Plays an Important Role in Maintaining its Quality during Storage

2018 ◽  
Vol 38 (2) ◽  
pp. 167
Author(s):  
Lince Mukkun ◽  
Herianus J.D. Lalel ◽  
Yuliana Tandirubak
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Insect Pests ◽  
Initial Moisture Content ◽  
High Water ◽  
High Water Content ◽  
Initial Water Content ◽  
Initial Water ◽  
Plant Materials ◽  
Randomized Design

Maize is one of the important staple foods for people in Timor, East Nusa Tenggara Province, Indonesia. Subsistent farmers store the maize for their own consumption until the next harvest season, for seed and feed.  However, high initial water content of the kernel due to improper drying prior storage initiate serious damage and losses during the maize storage.  High water content promotes the growth of fungi and insects, and increase respiration rate, resulting in rapid deterioration of maize. The purpose of this study was to determine the initial moisture content that might minimize damage and losses of maize in the farmers’ storage, and to study the effects of some plant materials that are used to smoke corns before storage. The experiment was initiated by sun-drying the harvested corncobs for 0, 2, 4, 6, 8, and 10 days (6 hours a day). This experiment was designed using Completely Randomized Design with 6 treatments and 3 replications. Dried corncobs were stored in the farmer’s storage for 4 months. The effects of maize kernels’ initial water content on the development of water content in kernels; the percentage of damaged kernels; and the species of pathogen and insects were investigated during storage with 2-week intervals.  The results demonstrated that drying the corncobs prior storage for 10 days, resulting in 12.96% of water content, significantly decreased the percentage of seed damage to 6.5%, as compared to without drying process which resulted  in 63%.  Aspergillus flavus, Fusarium sp., and Penicillium sp were found to be the main pathogen during storage.  There are no insect pests found during the storage. 

scholarly journals Irregular snow crystals: Structural features as revealed by low temperature scanning electron microscopy

Scanning ◽  
2006 ◽  
Vol 24 (5) ◽  
pp. 247-256 ◽  
Author(s):  
William P. Wergin ◽  
Eric F. Erbe ◽  
Albert Rango ◽  
James Foster ◽  
Christopher Pooley
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Temperature ◽  
Structural Features ◽  
Snow Crystals ◽  
Temperature Scanning ◽  
Scanning Electron

Study on the Difference between Turfy Soil and Normal Peat Soil in China

2011 ◽  
Vol 105-107 ◽  
pp. 1551-1554 ◽  
Author(s):  
Yan Lv ◽  
Lei Nie ◽  
Kai Xu ◽  
Zhan Dong Su
Keyword(s):  
Peat Soil ◽  
Specific Weight ◽  
High Water ◽  
Structural Features ◽  
Organic Content ◽  
Engineering Properties ◽  
High Water Content ◽  
Consolidation Coefficient ◽  
The Difference ◽  
High Organic Content

As the special soil, turfy soil and peat soil in China contained some similar properties with high void ratio, high water content, high organic content, etc. But turfy soil also had properties which difference from peat soil. In this paper, based on the formation of the cause and geological environment and geomorphologic characteristics of geological in the quaternary, took the typical and widespread turfy soil and peat soil regions for example, systematically discussed the material composition and macroscopic and microcosmic structural features, put further research on the physical chemistry mechanical characteristics. Then the come to the conclusion that the essential reason for difference between turfy soil and peat soil were decomposition degree and organic content. The result that worse engineering properties such as higher the moisture content, porosity, compressibility, internal cohesion and the lower specific weight, consolidation coefficient and permeability were due to the lower decomposition degree and higher organic content of turfy soil than peat soil. It can provide reference to the practical projects of turfy soil to distinguish peat soil according to this characteristic.

scholarly journals Effects of low temperature storage of Mastura (J37) jackfruit bulbs on the physical quality of jackfruit frozen confection

2020 ◽  
Vol 1 (2) ◽  
pp. 1-4
Keyword(s):  
Low Temperature ◽  
High Water ◽  
Downstream Processing ◽  
Freeze Storage ◽  
High Water Content ◽  
Low Temperature Storage ◽  
Soluble Solid ◽  
Processing Line ◽  
Value Add ◽  
Refrigeration Storage

Mastura (J37) jackfruit variety planted in Pahang (Malaysia) is less preferred by the consumers due to its low sweetness and high-water content properties. This has caused major backlog in the plantation as reported by Pahang State Farmers Association (PASFA). In this study, among the proposed solutions given was to build a frozen confection processing line to further process the flesh. The jackfruit used were vacuum-packed and stored under refrigerated and frozen conditions. The overrun, melting resistance, and hardness of jackfruit frozen confection produced from jackfruit stored in both low temperature conditions showed comparable results. The overrun of 50 to 55 % were obtained for frozen samples at different weeks. Jackfruit frozen confections had lower overrun compared to the controlled sample as air incorporation was prevented by the elements contained in jackfruit. The control frozen confection sample without addition of jackfruit puree resulted in an average melting mass of 24.6 g and melting resistance of 59 % which was the strongest melting resistance in comparison to other jackfruit frozen confections. The inconsistent hardness of jackfruit frozen confections suggests that the content of total soluble solid increased throughout week 1 to week 3 for refrigeration storage and week 1 to week 6 for deep-freeze storage had no trending effect on the hardness of frozen confection. The output obtained from this work provides data for the downstream processing of Mastura (J37) jackfruit. These data are helpful as they contribute towards the understanding of further processing of this particular jackfruit variety into end products, in order to solve the issue faced by PASFA. The solution helps decrease waste generated from the surplus and value add the variety.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Electron microscopy and diffraction studies of polyimides

1983 ◽  
Vol 41 ◽  
pp. 28-29
Author(s):  
O.C. de Hodgins ◽  
K. R. Lawless ◽  
R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Structural Features ◽  
Inert Atmosphere ◽  
Polyimide Films ◽  
Resolution Electron ◽  
The Matrix ◽  
High Resolution Electron Microscope ◽  
Diffraction Patterns ◽  
Polymeric Samples

Commercial polyimide films have shown to be homogeneous on a scale of 5 to 200 nm. The observation of Skybond (SKB) 705 and PI5878 was carried out by using a Philips 400, 120 KeV STEM. The objective was to elucidate the structural features of the polymeric samples. The specimens were spun and cured at stepped temperatures in an inert atmosphere and cooled slowly for eight hours. TEM micrographs showed heterogeneities (or nodular structures) generally on a scale of 100 nm for PI5878 and approximately 40 nm for SKB 705, present in large volume fractions of both specimens. See Figures 1 and 2. It is possible that the nodulus observed may be associated with surface effects and the structure of the polymers be regarded as random amorphous arrays. Diffraction patterns of the matrix and the nodular areas showed different amorphous ring patterns in both materials. The specimens were viewed in both bright and dark fields using a high resolution electron microscope which provided magnifications of 100,000X or more on the photographic plates if desired.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

Some Structural Features of Metaphase Chromosomes of Mice and Men

1967 ◽  
Vol 25 ◽  
pp. 190-191
Author(s):  
Godfrey C. Hoskins ◽  
Betty B. Hoskins
Keyword(s):  
Electron Microscopy ◽  
Electron Micrographs ◽  
Structural Features ◽  
Metaphase Chromosomes ◽  
The Future ◽  
Of Mice And Men ◽  
Mouse Cells ◽  
Human And Mouse

Metaphase chromosomes from human and mouse cells in vitro are isolated by micrurgy, fixed, and placed on grids for electron microscopy. Interpretations of electron micrographs by current methods indicate the following structural features.Chromosomal spindle fibrils about 200Å thick form fascicles about 600Å thick, wrapped by dense spiraling fibrils (DSF) less than 100Å thick as they near the kinomere. Such a fascicle joins the future daughter kinomere of each metaphase chromatid with those of adjacent non-homologous chromatids to either side. Thus, four fascicles (SF, 1-4) attach to each metaphase kinomere (K). It is thought that fascicles extend from the kinomere poleward, fray out to let chromosomal fibrils act as traction fibrils against polar fibrils, then regroup to join the adjacent kinomere.

Morphological Examination of a Herpes-type Virus Indigenous for Tree Shrews

1970 ◽  
Vol 28 ◽  
pp. 160-161
Author(s):  
J. P. Brunschwig ◽  
R. M. McCombs ◽  
R. Mirkovic ◽  
M. Benyesh-Melnick
Keyword(s):  
Electron Microscopy ◽  
Soft Tissue ◽  
Chick Embryo ◽  
Soft Tissue Sarcoma ◽  
Cell Cultures ◽  
Tree Shrew ◽  
Type Virus ◽  
Morphological Examination ◽  
Tree Shrews ◽  
Embryo Cells

A new virus, established as a member of the herpesvirus group by electron microscopy, was isolated from spontaneously degenerating cell cultures derived from the kidneys and lungs of two normal tree shrews. The virus was found to replicate best in cells derived from the homologous species. The cells used were a tree shrew cell line, T-23, which was derived from a spontaneous soft tissue sarcoma. The virus did not multiply or did so poorly for a limited number of passages in human, monkey, rodent, rabbit or chick embryo cells. In the T-23 cells, the virus behaved as members of the subgroup B of herpesvirus, in that the virus remained primarily cell associated.

Solving the mechanisms responsible for organelle behavior in vivo by same-cell correlative light and electron microscopy

1992 ◽  
Vol 50 (1) ◽  
pp. 14-15
Author(s):  
Conly L. Rieder
Keyword(s):  
Electron Microscopy ◽  
Quantitative Analysis ◽  
Light Microscopy ◽  
Living Cell ◽  
Light And Electron Microscopy ◽  
Time Behavior ◽  
Dynamic Interactions ◽  
Positive Identification ◽  
Cellular Components

The behavior of many cellular components, and their dynamic interactions, can be characterized in the living cell with considerable spatial and temporal resolution by video-enhanced light microscopy (video-LM). Indeed, under the appropriate conditions video-LM can be used to determine the real-time behavior of organelles ≤ 25-nm in diameter (e.g., individual microtubules—see). However, when pushed to its limit the structures and components observed within the cell by video-LM cannot be resolved nor necessarily even identified, only detected. Positive identification and a quantitative analysis often requires the corresponding electron microcopy (EM).

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