• Journal of Environmental Science International
• /
• v.12 no.10
• /
• pp.1131-1136
• /
• 2003

To examine whether salt stress would alter or not contractility of isolated rat aorta, under anesthesia with sodium pentobarbital(50 mg kg-1 i.p.), male Sprague Dawley rats(300-330 g) were subjected to 0, 50, and 150 mM of sodium chloride at 37$^{\circ}C$ for 60 min. where as the sham group was left at modified Krebs-bicarbonate solution. To measure contractile response of vascular ring preparation isolated from rat was determined in organ bath and was recorded on physiograph connected to isometric transducer. And the strip was checked for expression of heat shock protein(Hsp) by Western blotting. One, three and eight hours later, we measured vascular contractility of isolated rat aorta treated with KCI, phenylephrine from organ bath study. The dose-vascular responses of potassium chloride and phenylephrine showed a little augmentation by NaCl concentration in the strips exposed to NaCl for 8 hours. And the response of relaxation induced by nitroprusside and acetylcholine was not influenced by NaCl stress in isolated aorta ring for 8 hours, respectively. Expression pattern of Hsp 70 of vascular muscle in isolated rat aorta showed a little increase in 150 mM NaCl group at 8 hours after NaCl treatment but not at 3 hours, and Hsp 60 expression of rat aorta was markedly increased in 50 mM NaCl group at 8 hours after NaCl treatment. Taken together, NaCl induced dose-and time dependent accumulation of the Hsp but not affected contraction of rat aorta. These data suggest that short term high salt stress was not sufficient to induce hypertension of rat aorta.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.23 no.3
• /
• pp.294-301
• /
• 2020

Man-In-Simulant Test(MIST) provides a test method to evaluate chemical protective equipments such as protective garments, gloves, footwear and gas mask. The MIST chamber is built to control concentration of chemical vapor that has a activity space for two persons. Non-toxic methyl-salicylate(MeS) is used to simulate chemical agent vapor. We carried out to measure inward leakage MeS vapors by using passive adsorbent dosimeter(PAD) which are placed on the skin at specific locations of the body while man is activity according to the standard procedure in MIST chamber. But more time is required for PADs and there is concern of contamination in PADs by recovering after experiment. Therefore detector for measuring in real time is necessary. In order to analyze in real time the contamination of the personal protective equipment inside the chemical environment, we have developed a wireless real-time gas detector. The detector consists of 8 gas-sensors and 1 control-board. The control-board includes a CPU for processing a signal, a power supply unit for biasing the sensor and Bluetooth-chipset for transmission of signals to external PC. All signals from gas-sensors are converted into digital signals simultaneously in the control-board. These digital signals are stored in external PC via Bluetooth wireless communication. The experiment is performed by using protective equipment worn on manikin. The detector is mounted inside protective equipment which is capable of providing a real-time monitoring inward leakage MeS vapor. Developed detector is demonstrated the feasibility as real-time detector for MIST.

• Journal of Korean Institute of Industrial Engineers
• /
• v.30 no.1
• /
• pp.11-16
• /
• 2004

Oxygen is an essential element for human beings' physical and mental activities, and in particular, plays an important role in brain functions. The present study attempted to investigate the effects of supply of highly concentrated (30%) oxygen on human ability of visuospatial cognition, compared to air of normal oxygen concentration (21%). This study sampled eight male university students (the average age: 23.5) as subjects. An equipment that supplies 21% and 30% oxygen at a constant rate of 8L/min was developed. Two types of questionnaire containing 20 questions were developed to measure the ability of visuospatial cognition, and accuracy and reaction time were calculated from the result of task performance. The average accuracy was $50.63{\pm}8.63$ [%] and $62.50{\pm}9.64$[%] for 21%and 30% oxygen respectively, and a statistically significant difference was found in the accuracy between the two types of oxygen. The average reaction time was $6.60{\pm}O.77$ [sec] and $7.23{\pm}0.69$ [sec] for 21%and 30% oxygen respectively, and a statistically significant difference was not found in the reaction time. The results showed that there is no difference in the average reaction time but the average accuracy rises with the supply of highly concentrated (30%) oxygen, indicating that the supply of highly concentrated oxygen has a partially positive effect on the ability of visuospatial cognition.

• KSBB Journal
• /
• v.9 no.3
• /
• pp.319-324
• /
• 1994

A biosensor for the measurement of malate has been constructed by the sodium-alginate immobilized bundle sheath cell tissue of corn leaf containing malate dehydrogenase (decarboxylating) (EC 1. 1. 1. 40) on the CO2 gas-sensing electrode. The proposed tissue sensor had the linear in the range of malate concentration $5.5{\times}10^{-5}M∼2.5{\times}10^{-2}M$ with a slope of 53.5 mV/decade in 0.02M Tris-HCl buffer solution at optimum pH 8.0, and $25^{\circ}C$. A response time was 16∼18min. The present L-malate sensing tissue sensor is stable for more than one week. At pH 7.4, Km value was $0.6{\times}10^{-5}M$. The various kinds of salt did not effect the signal of malate tissue biosensor as the inhibitor. We can measure the malate by the CO2 electrode at the pH=8.0. Thus, the proposed tissue sensor will be useful for the measurement of malate.

• Journal of the Korea Institute of Building Construction
• /
• v.20 no.1
• /
• pp.93-102
• /
• 2020

The purpose of this study is to find out how to measure the stress related to accidents at the construction site promptly and conveniently to prevent safety accidents of construction workers. Accordingly, we analyzed the correlations between the questionnaire tool index that measures the stress associated with complex psychology of humans by integrating emotion, cognition, physical and behavioral responses, and basic brain waves, SEF-90, concentration, stress index from brain wave. As a result, which had the highest correlation with the stress measured through the questionnaire, was the SEF-90, and the regression analysis between two independent variables yielded a specific regression equation. This suggests the possibility of measuring the integrated stress of construction workers through the EEG signal at the construction site, and it can be used for the safety management of the construction site in the future.

• KSBB Journal
• /
• v.28 no.1
• /
• pp.18-23
• /
• 2013

The purpose of this work was to investigate the several functional characteristics of Lactobacillus sakei JK-17 isolated from long-term fermented kimchi, Muk Eun Ji. Initially, phylogenetic analysis using 16S rRNA sequencing was performed to identify the isolate JK-17, and the strain could be assigned to Lactobacillus sakei and designated as L. sakei JK-17. The strain was registered in GenBank as [JX841311]. The changes of bacterial growth and residual organic acids were monitored and HPLC was used to measure quantitatively two organic acids, lactic acid and acetic acid, produced in the culture during 84 hours of incubation. During the incubation period, several functional characteristics of L. sakei JK-17 were examined. L. sakei JK-17 culture depleted nitrite concentration 94.75%. Antioxidant activity of cultural supernatants of L. sakei JK-17 was approx. 53.8%, and ${\beta}$-galactosidase activities were 0.243 units/mL at pH 7.0 and 0.387 units/mL at pH 4.1, respectively. The antibacterial activities against food-poisoning causing bacteria were examined with 20-fold concentrated culture supernatants from L. sakei JK-17 and the antibacterial effects were clearly observed against all bacteria tested in this work.

• Journal of the East Asian Society of Dietary Life
• /
• v.14 no.4
• /
• pp.338-342
• /
• 2004

This study was performed to measure the antioxidant effects of red ginseng extracts which antioxidation had been promoted through enzyme hydrolysis. In order to observe their tumor-suppressing effects, an anti-cancer medicine and Saponin-SOD, which was a highly antioxidant beverage made from red ginseng saponin adding SOD-like rice (with embryo buds) extracts, were administered to nude mice with large intestine cancer induced. There was a significant increase in the content of phenolic compounds as the enzyme was added. The red ginseng extracts showed a high electron-donating ability with the passage of time. The electron-donating ability was particularly high in the enzyme-treated red ginseng extract, and also observed as high in Saponin-SOD. The lipid-peroxide generation was inhibited depending on the concentration of Saponin-SOD added; the addition of 0.625% Saponin-SOD served to decrease the inhibition level up to 65% compared with the case of no addition (100%). As a result, it could be assumed that Saponin-SOD would strongly inhibit the oxidation of ghost membrane. After the cancer was induced in nude mice through the injection of SNUC-4 cell, there was a significant inhibition in the growth of tumors in nude mice into which Saponin-SOD were injected; the growth of tumors was gradually decreasing with the passage of time after the cancer induction. In particular, when Saponin-SOD was administered together with an anti-cancer medicine, the synergic effect was observed. In conclusion, Saponin-SOD, when used with an anti-cancer medicine, is expected to reduce the amount of free radical and lipid peroxide, which are known to cause harmful effects occurring from the internal application of medicine.

• Journal of the Korean Society for Railway
• /
• v.12 no.2
• /
• pp.276-284
• /
• 2009

Recently pile-supported embankments have emerged as an optimum method when the rapid construction and strict deformation of structures are required on soft soils. Especially geosynthetic-reinforced and pile-supported (GRPS) embankments are used worldwide as they can provide economic and effective solutions. However the load transfer mechanism in GRPS embankments is very complex, and not yet fully understood. Particularly the purpose and effect of geosynthetic inclusion are ambiguous and considered as an auxiliary measure assisting the arching effect of piles. Numerical parametric study using 3D finite element method has been conducted to investigate the effect of geosynthetic reinforcement on the load transfer mechanism of GRPS embankments. Numerical results suggested that as more stiffer geosynthetic is included, arching effect decreases considerably and the load concentration to the piles mostly caused by tension effect of geosynthetic. This finding is contradictory to the common understanding that geosynthetic inclusion only enhance the efficiency of load transfer. Consequently the design parameters determined from the numerical analyses are compared with those of three existing design methods. The problems of the existing methods are discussed.

• Korean Journal of Optics and Photonics
• /
• v.26 no.1
• /
• pp.9-16
• /
• 2015

We have developed ellipsometry lidar and measured aerosol and ice-cloud characteristics. To measure a full normalized backscattering phase matrix (NBSPM) composed of nine elements, we have designed an optical system with three kinds of transmission and three kinds of reception, composed of ${\lambda}/2$ waveplate, ${\lambda}/4$ waveplate and empty optic. To find systematic optical errors, we used clean day middle-altitude (4-6km) lidar signals for which the aerosol's concentration was small and its orientation chaotic. After calibrating our lidar system, we have calculated NBSPM elements scattered from an aerosol and from an ice cloud. In the case of an aerosol, we found that the off-diagonal values $m_{12},{\ldots},m_{34}$ of the NBSPM are smaller than those for a cirrus cloud. Also, the off-diagonal values of the NBSPM from a cirrus cloud depend on atmospheric conditions.

• Safety and Health at Work
• /
• v.8 no.1
• /
• pp.84-88
• /
• 2017

Background: Workers in slaughterhouses are exposed to a wide range of biological contaminants, such as bacteria and fungi, due to their working environment. This study aimed to assess the prevalence of respiratory disorders among workers in slaughterhouses. Methods: This study was conducted on 81 workers in slaughterhouses and 81 healthy office workers as a reference group. The American Thoracic Society standard respiratory symptoms questionnaire was used to determine the prevalence of respiratory disorders. Besides, lung function tests were conducted using a calibrated spirometer at the beginning (preshift) and at the end (postshift) of the $1^{st}$ working day. Single-stage Anderson sampler was used to measure the concentration of bioaerosols in different parts of slaughterhouses. Results: The prevalence of respiratory disorders, such as cough, productive cough, breathlessness, phlegm, and wheezing, was 3.17, 4.02, 3.07, 4.66, and 3.94 times, respectively, higher among workers in slaughterhouses compared with the reference group. Conclusion: The prevalence of respiratory disorders was significantly higher among workers in slaughterhouses. Thus, the significant reduction in the percentage predicted lung function among workers in slaughterhouses might be associated with exposure to bioaerosols in their work environment.