• Journal of the Korean Society for Precision Engineering
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• v.27 no.5
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• pp.85-91
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• 2010

In this paper, we present details on fabrication of single-cell electroporation microdevice, practical experiments of single-cell electroporation with our fabricated microdevice. Also, the continuous electroporation for the continuous flow of cells is used for high-throughput electroporation. The delivery efficiency and cell viability tests are provided and the successful GFP transfection into cells is also evaluated with a fluorescent microscope after electroporation. This device enables to reduce the size of samples and thus the use of small amount of reagents. Also, it makes it possible to permit to avoid cell discrimination (transfected cells versus non-transfected cells) encountered when traditional bulk electroporation is held.

• The Korean Journal of Food And Nutrition
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• v.5 no.2
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• pp.77-83
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• 1992

The optimum conditions and mechanisms for the plasmid-mediated genetic transformation of intact cells of Bacillus brevis Pl76-2, an extracellular protein producing bacterium by electroporation were investigated. It was found that pUB110 Plasmid DNA can be introduced into intact bacterial cells by electroporation. The frequency of transformation by this electroporation system depended upon the initial electric field strength, the capacity of the electric discharge capacitor, growth stage, number of successive pulses and composition of electroporation buffer. It was effective for transformation that cells were harvested, washed and resuspended with HSM [7M HEPES(PH 7.4), 272mM sucrose, 1 mM MgCl2] electroporation buffer when cell growth was attained to 1.2 at OD660. A maximum frequency of transformation of 2.40$\times$104 transformants per$\mu$g plasmid DNA was obtained by two succesive Pulses with an initial electric field strength of 12.5kV/cm and with a capacitance of 7.3uF.

• Journal of fish pathology
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• v.7 no.2
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• pp.95-103
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• 1994

We have prepared cDNA libray of loach. M. mizolepis in order to isolate cDNA clone of growth hormone gene. Total RNA was isolated from pituitary of loach, and then mRNA was further purified from total RNA by oligo (dT)-coupled magnetic beads. The purified mRNA was used as substrates to prepare cDNA. The resulting cDNA was ligated into the EcoRV/Smal site of pBlueKS+. The ligation mixture have transformed E. coli JM109 strain with electroporator to obtain high yield of transformation efficiency. All the transformants was screened with DIG-labeled Tilapia growth hormone gene by high density colony hybridization. After isolating 10 putative colonies showing the positive signals, secondary colony hybridization and southern hybridization could confirm it as true clones. The nucleotide sequence of one candidate, pCGHI, was compared with 312 bp DNA fragment used as DNA probe and show 52% relative homology to Tilapia growth hormone gene.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.12
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• pp.55-67
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• 2010

The electrical properties of a back drilled via-hole (BDH) without the open-stub and the plated through via-hole (PTH) with the open-stub, which is called the conventional structure, in a high-count multi~layered (HCML) printed circuit board (PCB) were investigated for a high-speed digital system, and a selected inner layer to transmit a high-speed signal was farthest away from the side to mount the component. Within 10 GHz of the broadband frequency, a design of experiment (DOE) methodology was carried out with three cause factors of each via-hole structure, which were the distance between the via-holes, the dimensions of drilling pad and the anti-pad in the ground plane, and then the relation between cause and result factors which were the maximum return loss, the half-power frequency, and the minimum insertion loss was analyzed. Subsequently, the empirical formulae resulting in a macro model were extracted and compared with the experiment results. Even, out of the cause range, the calculated results obtained from the macro model can be also matched with the measured results within 5 % of the error.

• Korean Journal of Heritage: History & Science
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• v.42 no.1
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• pp.144-157
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• 2009

Nondestructive methods to check the vitality of trees and to find out internal decay of old-giant trees include the use of electrical resistance, ultrasound transmission time, microdrilling, and infrared thermography etc. Among these, ultrasound transmission offers some advantages compared to others such as it is an entirely nondestructive detection method and it can be applied to very big trees. However, the ultrasound equipment is comparatively expensive and not broadly spread yet. On the other hand, Shigometer is versatile to be applied to check vitality of the tree and find out internal decay. Electrical conductivity of plant tissues is a very useful characteristics to determine the vitality and internal decay of trees. Electrical resistance of cambial area tells about the vitality of a tree and electrical resistance of heartwood reveals discoloration or decay of it. For determination of the vitality of the tree, the standard equation for calibration of measured electrical resistances should be developed by measuring and analyzing electrical resistance from at least 30-40 trees of the same species with that tree. All the factors, especially tree species, diameter of the stem, and temperature, which can altered the electrical resistance of trees, should be taken into consideration in the development of the equation. If the standard equation is developed for old-giant trees that we should conserve, it will be very useful. In addition, periodical and continued measuring of a certain tree will help to determine the condition of the tree by comparing the measurement with accumulated data of the tree. Measuring electrical resistance of wood might not require the standard equation. But it also needs to check electrical resistance of sound wood of the same tree species. If the stems that should be examined is thicker than 40cm, it is better to use the ultrasound measurement combined to Shigometer.

• Tunnel and Underground Space
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• v.26 no.1
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• pp.1-11
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• 2016

This study deals with the case that was the field application of the microseismic monitoring techniques for the stability monitoring in a domestic mine. The usefulness and limitations of the microseismic techniques were examined through analyzing the microseismic monitored data. The target limestone mine adopted a hybrid room-and-pillar mining method to improve the extraction ratio. The accelerometers were installed in each vertical pillar within the test bed which has the horizontal cross-section $50m{\times}50m$. The measured signals were divided into 4 types; blasting induced signal, drilling induced signal, damage induced signal, and electric noise. The stability analysis was performed based on the measured damage induced signals. After the blasting in the mining section close to the test bed, the damage of the pillar was increased and rockfall near the test bed could be estimated from monitored microseismic data. It was possible to assess the pillar stability from the changes of daily monitored data and the proposed safety criteria from the accumulated monitored data. However, there was a difficulty to determine the 3D microseismic source positions due to the 2D local sensor arrays. Also, it was needed to use real-time monitoring methods in domestic mines. By complementing the problems encountered in the mine application and comparing microseismic monitored data with mining operations, the microseismic monitoring technique can be used as a better safety method.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.659-666
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• 2003

Endoglucanase A from Clostridium thermocellum which is resistant to pancreatic proteinase was selected out of numbers cellulases then were expressed in lactobacilli. Recombinant lactobacilli expression vector, pSD1, harboring the endoglucanase gene from C. thermocellum under the control of its own promoter, was constructed. Both L. bulgaricus and L. plantarum were electrotransformed with pSD1. The endoglucanase activities of 0.120 and 0.144 U/ml were found in culture media of L. bulgaricus and L. plantarum containing pSD1, respectively. In vitro survival characteristics of the transformed lactobacilli were tested. Both L. bulgaricus and L. plantarum showed a similar resistance to low pH 3. Moreover, L. plantarum was bile-salt resistant in the presence of 0.3 and 1% oxgall. L. bulgaricus and L. plantarum showed a rather homogenous resistant pattern against the tested antibiotics. Both of the strains were resistant to amikacin, gentamicin, streptomycin, kanamycin, and colistin.

• Journal of Life Science
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• v.25 no.11
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• pp.1290-1297
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• 2015

Studies of the inactivation of a gene encoding pyruvate decarboxylase, pdc, in an ethanol-producing bacterium, Zymomonas mobilis, identified a mutant strain with 50% reduced PDC activity. To evaluate the possibility of a carbon-flux shift from an ethanol pathway toward higher value fermentation products, including pyruvate, succinate, and lactate, fermentation studies were carried out. Despite attempts to silence pdc expression in the wild-type strain ZM4 using cat-inserted pdc and pdc-deleted homologs by electroporation, the strain isolated showed partial gene activation. Fermentation experiments with the PDC mutant strain showed that the reduced expression level of PDC activity resulted in decreased rates of substrate uptake and ethanol production, together with increased pyruvate accumulation of 2.5 g l^-1 , although lactate and succinate concentrations were not significantly enhanced in these modified strains. Despite numerous attempts, no strains were isolated in which complete pdc inactivation occurred. This result indicates that the ethanol fermentation pathway of this bacterium is totally dependent on the activity of the PDC enzyme. To ensure a redox balance of intracellular NAD and NADH levels, other enzymes, such as lactate dehydrogenase for lactate, and enzymes involved in the production of succinic acid, such as pyruvate dehydrogenase (PDH) and malic enzymes, may be needed for their increased end-product production.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.2
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• pp.1-9
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• 2009

Impact of daylighting on the visual environment can improve occupant's well-being by providing visual comfort. Also, daylighting can save energy. However, glare from window can be a direct hazard to vision and can cause serious discomfort. Selecting glare source on a window plane is very important for evaluating discomfort glare from windows. But former glare indices can not identify the range of the glare source properly. In this study, difference in glare sensation with uniform and non-uniform glare sources are evaluated to identify the range of the glare source. The glare source was assumed as $120{\times}120[cm]$ window model. The window was divided into three parts with different luminance values. The experiment was conducted under 1[m], 1.5[m], 3[m] distance from the glare source. Two results were obtained from the experiments. First, the degree of discomfort glare increased as average window luminance increased. Second, the middle and lower part of the window plane can affect evaluation of discomfort glare as well as the upper part of the window plan. These results can be used for selecting the glare source in a window with non-uniform luminance.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.5.2-5
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• 1982

With the improvement of living standard and socioenvironmental change, esophageal stricture due to acetic acid, Hcl, insecticides and lye has led to decrease remarkably. Esophageal stricture has decreased because of immediate treatment and adequate management. However there are still sporadic incidents of esophageal stricture due to inadequate treatment and uncooperation of patients. The authors recently have experienced seven severe cases of esophageal stricture. All six patients were treated with 18-51 French Sippy esophageal dilating bougie. One patient was transfered to thoracic surgery department due to complete esophageal obstruction. Case 1. A 23 year old housewife who ingested Hcl for suicide. After Witzel's operation, she visited to dilate esophageal first constriction stircture due to swallowing difficulty postoperation 2 months later. We were treated successfully. Case 2. A case of esophageal stricuture in the second and third physiologic constriction part. The patient was 51 years old man who ingested lye accidently, and was dilated by bougination. Case 3. The patient was 43 year-old man who ingested acetic acid as a mistake and was treated inadequately at hopsital. Inspite of treatment, esophageal stricture developed at the third physiologic part. We are trying to dilate the esophagues now. Case 4. The patient was 55 year-old woman who had ingested Hcl for the purpose of suicidal attempt. 2 months later gastroduodenal anastomoisis due to pyloric region stenosis, the first physiologic constriction stricture was dilated successfully. Case 5. The patient was 41 year-old woman who ingested Hcl for suicide 4 months ago. There was indwelled orogastric tube for 1 month but esophageal stricture developed at the first and 3rd constriction part. She was treated by using a bougination. Case 6. An athlete 21 year old man, ingested acetic acid 2 spoonful per 3 days by purpose in order to soften the bone for last 14 months. There was complete esophageal obsturction in esophagogram and transferred to the thoracic surgery department. Case 7. A 3 year-old girl was ingested lye at a accident. She had a bougination for 16 months under the general anesthesia for dilation due to whole irregular esophageal stricture. She developed lower esophageal perforation, but healed eventually.