scholarly journals Replacing critical point drying with a low-cost chemical drying provides comparable surface image quality of glandular trichomes from leaves of Millingtonia hortensis L. f. in scanning electron micrograph

2020 ◽  
Vol 50 (1) ◽  
Author(s):  
Raktim Bhattacharya ◽  
Sulagna Saha ◽  
Olga Kostina ◽  
Lyudmila Muravnik ◽  
Adinpunya Mitra
2020 ◽  
Author(s):  
Raktim Bhattacharya ◽  
Sulagna Saha ◽  
Olga Kostina ◽  
Lyudmila Muravnik ◽  
Adinpunya Mitra

Abstract Sample preparation including the dehydration and drying of the samples is the most intricate part in the field of scanning electron microscopy. Till to date, most of the sample preparation protocols use critical point drying with the help of liquid carbon dioxide. Very few cases have been reported where samples were dried using some chemical reagents. In this work, we have explored the possibility of using hexamethyldisilazane, a chemical drying reagent, for the preparation of plant samples. As glandular trichomes are one of the most fragile and sensitive surface structures found on plants, we chose to use Millingtonia hortensis leaf samples as our study materials that contain abundantly glandular trichome. The results obtained by this new method are identical with the results obtained from the critical point drying method, in every aspect.


Author(s):  
Charles TurnbiLL ◽  
Delbert E. Philpott

The advent of the scanning electron microscope (SCEM) has renewed interest in preparing specimens by avoiding the forces of surface tension. The present method of freeze drying by Boyde and Barger (1969) and Small and Marszalek (1969) does prevent surface tension but ice crystal formation and time required for pumping out the specimen to dryness has discouraged us. We believe an attractive alternative to freeze drying is the critical point method originated by Anderson (1951; for electron microscopy. He avoided surface tension effects during drying by first exchanging the specimen water with alcohol, amy L acetate and then with carbon dioxide. He then selected a specific temperature (36.5°C) and pressure (72 Atm.) at which carbon dioxide would pass from the liquid to the gaseous phase without the effect of surface tension This combination of temperature and, pressure is known as the "critical point" of the Liquid.


Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.


Author(s):  
Linda M. Sicko ◽  
Thomas E. Jensen

The use of critical point drying is rapidly becoming a popular method of preparing biological samples for scanning electron microscopy. The procedure is rapid, and produces consistent results with a variety of samples. The preservation of surface details is much greater than that of air drying, and the procedure is less complicated than that of freeze drying. This paper will present results comparing conventional air-drying of plant specimens to critical point drying, both of fixed and unfixed material. The preservation of delicate structures which are easily damaged in processing and the use of filter paper as a vehicle for drying will be discussed.


Author(s):  
N. Merk ◽  
A. P. Tomsia ◽  
G. Thomas

A recent development of new ceramic materials for structural applications involves the joining of ceramic compounds to metals. Due to the wetting problem, an interlayer material (brazing alloy) is generally used to achieve the bonding. The nature of the interfaces between such dissimilar materials is the subject of intensive studies and is of utmost importance to obtain a controlled microstructure at the discontinuities to satisfy the demanding properties for engineering applications . The brazing alloy is generally ductile and hence, does not readily fracture. It must also wett the ceramic with similar thermal expansion coefficient to avoid large stresses at joints. In the present work we study mullite-molybdenum composites using a brazing alloy for the weldment.A scanning electron micrograph from the cross section of the joining sequence studied here is presented in Fig. 1.


2017 ◽  
Vol 23 (S1) ◽  
pp. 1266-1267 ◽  
Author(s):  
Barbara Armbruster ◽  
Christopher Booth ◽  
Stuart Searle ◽  
Michael Cable ◽  
Ronald Vane

2007 ◽  
Vol 121 (10) ◽  
pp. 993-997 ◽  
Author(s):  
M Barakate ◽  
E Beckenham ◽  
J Curotta ◽  
M da Cruz

Introduction: The organisms that cause many device-related and other chronic infections actually grow in biofilms in or on these devices. We sought to examine the role of biofilm formation in chronic middle-ear ventilation tube infection.Case report: Scanning electron micrograph images are presented which demonstrate biofilm on a middle-ear ventilation tube removed from a five-year-old child's chronically discharging ear. A review of the relevant international literature explores the role of biofilms in chronic infection and discusses potential intervention strategies.Conclusion: Biofilms may be responsible for chronic middle-ear ventilation tube infection that resists treatment with conventional antibiotics.


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