A Comparison of the Size and Shape of Radiofrequency Lesions Produced by Different Temperatures Using Straight and Curved Electrodes

2000 ◽  
Vol 39 (2) ◽  
pp. 260 ◽  
Author(s):  
Kee Heon Lee ◽  
Seon Hye Yun ◽  
Hyun Ju Kim ◽  
Bae Hee Jung ◽  
So Young Lim ◽  
...  
2015 ◽  
Vol 20 (6) ◽  
pp. 316-320 ◽  
Author(s):  
Young Suk Kwon ◽  
So Young Lim ◽  
Jong Ho Kim ◽  
Ji Su Jang ◽  
Chul Ho Kim ◽  
...  

BACKGROUND: Understanding the size and shape of radiofrequency lesions is important to reduce side effects when applied to patients.OBJECTIVES: To investigate the radiofrequency lesions produced by the application of the Tew electrode for different temperatures and times.METHODS: The white from a fresh hen’s egg was placed in a rectangular glass container and warmed to 37°C. After immersion of the Tew electrode in the egg white, radiofrequency lesions were produced at 65°C, 70°C, 75°C, 80°C, 85°C and 90°C. For each temperature, photographs were taken at 10 s, 20 s, 30 s, 40 s, 50 s, 60 s, 70 s, 80 s, 90 s, 100 s, 110 s and 120 s. The size of the lesion was measured at each temperature and time. A mixed model was used to analyze the data.RESULTS: The size of the lesion increased with increasing temperature and time. There were statistically significant differences in the size of the internal radius between the 65°C and 70°C groups and the 70°C and 75°C groups, as well as in the 70°C and 75°C groups in the size of the external radius and the 60°C to 80°C groups in the size of the distal radius. The maximum lesion size was produced at 90°C and 120 s, and was 1.06±0.16 mm in internal radius, 0.37±0.15 mm in external radius, 0.39±0.04 mm in distal radius.CONCLUSION: The Tew electrode produces lesions following the contour of the tip, and the internal radius is larger than the external and distal radius. The best combination of temperature and time for lesioning using the Tew electrode is 80°C, for 60 s to 90 s.


2021 ◽  
Vol 1 (67) ◽  
pp. 38-42
Author(s):  
E. Klikin ◽  
N. Kuvardin ◽  
R. Lavrov

Aim. To obtain conglomerates from copper nanoparticles by the method of electroerosive dispersion in various liquid media (in 1% starch solution, ethanol, acetone, kerosene, petroleum ether) at two different temperatures (negative and room). Assessment of the influence of this factor on the size and shape of the resulting conglomerates. Methods. Methods based on visual observation of the obtained particles using a digital microscope at a magnification of 600x. Results. The results are presented in the form of micrographs of the obtained particles. Conclusions. Conclusions are drawn on the study of the influence of the temperature factor on the morphology (size, shape and ordering) of the resulting conglomerates.


2006 ◽  
Vol 100 (6) ◽  
pp. 4910-4916 ◽  
Author(s):  
Anjana Jain ◽  
S. Abhishek ◽  
Sangappa ◽  
S. S. Mahesh ◽  
R. Somashekar

1956 ◽  
Vol 33 (4) ◽  
pp. 627-644
Author(s):  
SMILJA MUČIBABIĆ

Populations of Chilomonas paramecium have been maintained in a standard concentration of nutrient medium (0.1% beef-extract with 0.1% sodium acetate), at eight different temperatures, from 5 to 36° C. The temperatures 5 and 36° C. did not support the growth of a population. The rate of population growth increased with increase of temperature up to a maximum, and then decreased. The maximum yield, on the other hand, was not affected, within wide limits, by different temperatures. The relationship between temperature and maximum size of population was different when maximum size was expressed in total number of organisms from that when maximum size was expressed in terms of total volume of organisms. In the former case, the maximum size increased with the increase of temperature; while in the latter it decreased with increase of temperature. Bělehrádek's temperature coefficient, b, of the multiplication rate of Chilomonas did not show significant differences for different temperature ranges, while the coefficients Q10, and the thermal increment µ were larger for the lower temperature range. The size and shape of Chilomonas were found to depend on the temperature and on the age of the population. With increase in temperature, the size of organisms decreased to a minimum and then increased again, so that organisms were largest at extreme temperatures. In general, the organisms were more slender at lower than at higher temperatures. At all temperatures, the flagellate increased in size at the beginning of population growth and later decreased. Variation in size and shape was greatest at the beginning of growth and during transition to the maximum stationary phase.


2008 ◽  
Vol 54 (2) ◽  
pp. 197 ◽  
Author(s):  
Eun-mi Choi ◽  
Keun-Man Shin ◽  
Sung-keun Nam ◽  
Il-Young Cheong

Author(s):  
J. L. Brimhall ◽  
H. E. Kissinger ◽  
B. Mastel

Some information on the size and density of voids that develop in several high purity metals and alloys during irradiation with neutrons at elevated temperatures has been reported as a function of irradiation parameters. An area of particular interest is the nucleation and early growth stage of voids. It is the purpose of this paper to describe the microstructure in high purity nickel after irradiation to a very low but constant neutron exposure at three different temperatures.Annealed specimens of 99-997% pure nickel in the form of foils 75μ thick were irradiated in a capsule to a total fluence of 2.2 × 1019 n/cm2 (E > 1.0 MeV). The capsule consisted of three temperature zones maintained by heaters and monitored by thermocouples at 350, 400, and 450°C, respectively. The temperature was automatically dropped to 60°C while the reactor was down.


Author(s):  
H.J.G. Gundersen

Previously, all stereological estimation of particle number and sizes were based on models and notoriously gave biased results, were very inefficient to use and difficult to justify. For all references to old methods and a direct comparison with unbiased methods see recent reviews.The publication in 1984 of the DISECTOR, the first unbiased stereological probe for sampling and counting 3—D objects irrespective of their size and shape, signalled the new era in stereology — and give rise to a number of remarkably simple and efficient techniques based on its distinct property: It is the only known way to obtain an unbiased sample of 3-D objects (cells, organelles, etc). The principle is simple: within a 2-D unbiased frame count or sample only cells which are not hit by a parallel plane at a known, small distance h.The area of the frame and h must be known, which might sometimes in itself be a problem, albeit usually a small one. A more severe problem may arise because these constants are known at the scale of the fixed, embedded and sectioned tissue which is often shrunken considerably.


Author(s):  
Uwe Lücken ◽  
Joachim Jäger

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.


Author(s):  
C J R Sheppard

The confocal microscope is now widely used in both biomedical and industrial applications for imaging, in three dimensions, objects with appreciable depth. There are now a range of different microscopes on the market, which have adopted a variety of different designs. The aim of this paper is to explore the effects on imaging performance of design parameters including the method of scanning, the type of detector, and the size and shape of the confocal aperture.It is becoming apparent that there is no such thing as an ideal confocal microscope: all systems have limitations and the best compromise depends on what the microscope is used for and how it is used. The most important compromise at present is between image quality and speed of scanning, which is particularly apparent when imaging with very weak signals. If great speed is not of importance, then the fundamental limitation for fluorescence imaging is the detection of sufficient numbers of photons before the fluorochrome bleaches.


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