• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.125-132
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• 2009

In order to develop probiotics which may be a viable alternative of antibiotic use in pig industry, five bacterial strains (Lactobacillus sp. HN 52, 92, 98, 235 and AP 116) possessing antimicrobial properties were selected from 500 strains isolates of pig intestines. The bacteriocin produced by Lactobacillus sp. HN 235 displayed a relative broad spectrum of inhibitory activity against all Enterococcus strains, Pseudomonas aeruginosa, Listeria monocytogenes and Clostridium perfringens using the spot-on-lawn method. The production of antimicrobial substance started in the middle of the exponential growth phase, reached maximum levels (6,400 AU/mL) in the stationary phase, and then declined. Bacteriocin activity remained unchanged after 30 min of heat treatment at $95^{\circ}C$ and stable from pH 2.0 to 10 for 1 h, or exposure to organic solvents; however, it diminished after treatment with proteolytic enzymes. The molecular weight of the bacteriocin was about 5 kDa according to a tricine SDS-PAGE analysis.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.12 s.148
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• pp.1527-1534
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• 2005

In order to clarify the characteristics of the thermo-physiological responses of the child and to understand the influence of the country where the child has grown up on the responses, the thermo-physiological responses of the Japanese children(J group) and the Korean children(K group) were examined. The subject wearing shorts was exposed first to a thermo neutral room$(Ta=28.5^{\circ}C)$ for 1 hour, then transferred to a cold$(Ta=22^{\circ}C)$ or a hot$(Ta=37^{\circ}C)$ room for 1 hour. The experiment was done in the climate chamber of Bunka Women's University in the summer of 1997 for Japan, and in the climate chamber in the Keimyung University in the summer of 1998 for Korea. The subjects consisted of 5 boys and 5 girls aged 7-9 years in Japan and 4 boys and 4 girls aged 7-9 years in Korea. As a result: 1) The rectal temperature increased slightly with a rise in air temperature. K group showed a slightly higher rectal temperature. 2) The skin temperature of the hand and foot decreased conspicuously during cold exposure. It was more in the K group than in the J group. 3) Relative local sweat rates were similar in the two groups at $22^{\circ}C\;and\;28.5^{\circ}C$, while they were considerably different at $37^{\circ}C$. Even perspiration was observed over the whole body in the J group but the perspiration was large in the trunk and low in the extremity in the K group. 4) The heart rate was higher in the J group than in the K group but it increased with the rise of the air temperature in both groups.

• Journal of Preventive Medicine and Public Health
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• v.32 no.2
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• pp.191-199
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• 1999

Objectives: To examine the relationship between air pollution exposure and mortality in Seoul for the years of 1991-1995, Methods: Daily counts of death were analyzed by general additive Poisson model, with adjustment for effects of secular trend, seasonal factor, day of the week, heat wave, temperature, and humidity. Pollution variables were ozone, nitrogen dioxide, total suspended particles(TSP), and sulfur dioxide. Results: Daily death counts were associated with ozone(1 day before), nitrogen dioxide(1 day before), TSP(2 days before), sulfur dioxide(2 days before). The association with ozone was most statisfically significant and independent of other air pollutants. Increase of 100 ppb in ozone was associated with 0%(95% Cl= 2%-10%) increase in the daily number of death, This effect was greater in persons aged 65 and older. The relative risks of death from respiratory disease and cardiovascular disease were greater than for all-cause mortality in each pollutant. After ozone level exceeds 25 ppb, the dose-response relationship between mortality and ozone was almost linear. However, the effect of TSP, sulfur dioxide, and nitrogen dioxide on mortality might be confounded with each other. Conclusion: Daily variations in air pollution within the range currently occurring in Seoul might have an adverse effect on daily mortality.

• Journal of Pharmaceutical Investigation
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• v.33 no.2
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• pp.145-149
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• 2003

Manufacturing facilities of the pharmaceuticals must meet certain level of the cleanness required so that foreign substances such as dust, moisture, heat, microorganism, or virus do not contaminate the product. In case of radiopharmaceuticals for medical treatment and diagnosis, not only should the operators and environment be protected from radiation but also need to be isolated from the foreign contaminant. Therefore, manufacturing facilities for radiopharmaceuticals must satisfy the design standards of both hot cell and clean room which are specified by GMP. However, standards of maintaining negative pressure for preventing spread of radioactive contaminant in isolated facilities conflict with the standards of maintaining positive pressure for keeping cleanness. To solve this problem, air pressure of hot cell was designed lower than in the adjacent area to meet standards of the radiation safety. To keep higher cleanness in certain part of the hot cell for filling, minimal relative positive pressure allows. In order to effectively maintain the cleanness that is required for production of Tc-99m generator, which takes 70% of whole demand of radiopharmaceuticals, the rooms placed in each side of production room are used as a buffer area and three lead hot cells are installed in production room. In this research, we established the appropriate engineered design concept for Tc-99m generator manufacturing facility, which satisfies both GMP cleanness standard for preventing particles, bacteria, other contaminants and the regulations of radiation safety for supervising and controlling the amount of radiation exposure and exhausted radioactivity. And the concept of multi-barrier buffer zones is introduced to apply negative air pressure for hot cell with first priority and to continue relative positive air pressure for clean room.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.3
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• pp.389-396
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• 2018

The Kori-1 Nuclear Power Plant (NPP), WH 2-Loop Pressurized Water Reactor (PWR) operated for approximately 40 years in Korea, was permanently ceased on June 18, 2017. To reduce worker exposure to radiation by reducing the dose rate in the system before starting main decommissioning activities, the permanently ceased Kori-1 NPP will be subjected to full system decontamination. Generally, the range of system decontamination includes Reactor Pressure Vessels (RPV), Pressurizer (PZR), Steam Generators (SG), Chemical & Volume Control System (CVCS), Residual Heat Removal System (RHRS), and Reactor Coolant System (RCS) piping. In order to decontaminate these systems and equipment in an effective manner, it is necessary to evaluate the influence of the flow characteristics in the RCS during the decontamination period. There are various methods of providing circulating flow rate to the system decontamination. In this paper, the flow characteristics in Kori-1 NPP reactor coolant according to RHR pump operation were evaluated. The evaluation results showed that system decontamination using an RHR pump was not effective at decontamination due first to impurities deposited in piping and equipment, and second to the extreme flow unbalance in the RCS caused deposition of impurities.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.3
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• pp.183-192
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• 2005

Natural ventilation in radioactive waste repositories is considered to be less efficient than mechanically forced ventilation for the repository working environment and hygiene & safety of the public at large, for example, controlling the exposure of airborne radioactive particulate matter. It is, however, considered to play an important role and may be fairly efficient for maintaining environmental conditions of the repository over the duration of its lifetime, for example, moisture content and radon (Rn) gas elimination in repository. This paper describes the feasibility of using natural ventilation which can be generated in the repository itself, depending on the conditions of the natural environment during the periods of repository construction and operation. Evidences from natural cave analogues, actual measurements of natural ventilation pressures in mountain traffic tunnels with vertical shafts, and calculations of airflow rates with given natural ventilation pressures indicate possible benefits from passive ventilation for the prospective Korean radioactive waste repository. Natural ventilation may provide engineers with a cost-efficient method for heat and moisture transfer, and radon (Rn) gas elimination in a radioactive waste repository. The overall thermal performance of the repository may be improved. The dry-out period may be extended, and the seepage flux likely would be decreased.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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• pp.771-781
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• 2015

To examine if the molecular chaperone DnaK operon proteins of Streptococcus suis type 2 (SS2) are involved in adhesion to host cells, the abundance values of these proteins from the surface of two SS2 strains of different adhesion capability were compared. Their roles in growth and adhesion to human laryngeal epithelial cell line HEp-2 cells were investigated on SS2 strain HA9801 and its mutants with DnaK operon genes partially knocked-out (PKO mutant) under heat stress. The major difference was that DnaJ was more abundant in strain HA9801 than in strain JX0811. Pretreatment of the bacteria with hyperimmune sera to DnaJ, but not with those to other proteins, could significantly reduce SS2 adhesion to HEp-2 cells. PKO of dnaJ g ene resulted in decreased SS2 growth at 37℃ and 42℃, and reduced its adhesion to HEp-2 cells. The wild-type strain stressed at 42℃ had increased expression of DnaJ on its surface and elevated adhesion to HEp-2 cells, which was also inhibitable by DnaJ specific antiserum. These results indicate that the DnaJ of S. suis type 2 is important not only for thermotolerance but also for adhesion to host cells. Because DnaJ expression is increased upon temperature upshift with increased exposure on the bacterial surface, the febrile conditions of the cases with systemic infections might help facilitate bacterial adhesion to host cells. DnaJ could be one of the potential candidates as a subunit vaccine because of its good immunogenicity.

• Environmental Analysis Health and Toxicology
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• v.14 no.4
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• pp.189-201
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• 1999

Lead (Pb) is ubiquitous in the urban environment and is a well-known toxic element. It may cause adverse health effects on hematopoietic system, peripheral and central nervous systems, kidney functions, and others. In recent decades, lead concentration in blood has been widely used one of indicators for lead exposure and risk evaluation. In this study, we determined the blood-lead levels in general populations of Korea, and investigated the relationship among blood-lead levels, sociobehavioral factors, and lead concentrations in the contacted environments such as ambient air, drinking water, and foods. The study subjects consisted of volunteers who had lived in the residential or industrial area in Korea. Information about gender, age, living area, occupation, smoking, heat system, and dietary habits, etc was collected using a self-reported questionnaires. The lead concentrations of environments were collected by literature search to the study area. Participated subjects in industrial area were 726 and their blood-lead levels were 8.58 $\mu\textrm{g}$/dl for males and 6.26 $\mu\textrm{g}$/dl for female in average. The other subjects in residential area were 317 and their blood-lead levels were 4.58 $\mu\textrm{g}$/dl for males and 3.49 $\mu\textrm{g}$/dl for female in average. The distribution of blood-lead level in the industrial subjects was well fitted to the log -normal distribution and that in the residential subjects was well fitted to the normal distribution. Blood-lead levels in both area were affected by gender, smoking habit, age and residence duration except age in industrial area and residence duration in residential area. It was identified that 30% of blood-lead level was contributed from the inhalation of ambient air in the industrial area, and 8.4% of blood-lead level was from that in the residential area. from this study, it would be suggested for the health risk assessment and management of lead pollution concerns in urban, industrial and rural areas.

• Journal of Astronomy and Space Sciences
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• v.17 no.1
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• pp.53-66
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• 2000

We developed low light CCD imaging system using thermoelectric cooling method collaboration with a company to design a commercial model. It consists of Kodak KAF-0401E(768$\times$512 pixels) CCD chip, thermoelectric module manufactured by Thermotek. This TEC system can reach an operative temperature of $-25^{\circ}C$. We employed an Uniblitz VS25s shutter and it has capability a minimum exposure time 80ms. The system components are an interface card using a Korea Astronomy Observatory (hereafter KAO) ISA bus controller, image acquisition with AD9816 chip, that is 12bit video processor. The performance test with this imaging system showed good operation within the initial specification of our design. It shows a dark current less than 0.4e-/pixel/sec at a temperature of $-10^{\circ}C$, a linearity 99.9$\pm$0.1%, gain 4.24e-/adu, and system noise is 25.3e-(rms). For low temperature CCD operation, we designed a TEC, which uses a one-stage peltier module and forced air heat exchanger. This TEC imaging system enables accurate photometry($\pm$0.01mag) even though the CCD is not at 'conventional' cryogenic temperatures(140k). The system can be a useful instrument for any other imaging applications. Finally, with this system, we obtained several images of astronomical objects for system performance tests.

• Journal of Ginseng Research
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• v.3 no.2
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• pp.168-186
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• 1979

Three hundred gram of Korean ginseng root was extracted with 95% ethanol on a boiling water bath for about 300 hr. Evaporation of alcohol yieled 50.2g of dark brown residue which was used by dissolving 4 mg of the residue in 1 ml of physiological saline. The ginseng group and the saline group received each day 0.5 ml per 100 g body weight of ginseng extract and physiological saline, respectively. Both the ginseng and saline group with stress were exposed to positive radial acceleration (1∼29g), cold (5$^{\circ}C$, 0$^{\circ}C$ &-10$^{\circ}C$) and heat (35$^{\circ}C$) environment, and surgical stress. After termination of the last stress, the tolerance, body weight, visceral organ weight, basal metabolism rate, rectal temperature, the number of erythrocyte and leucocyte, hemoglobin level, hematocrit ratio, total serum protein content and it's fraction and the content of adrenal ascorbic acid in the experimental animal exposed to stress were measured and at the corresponding periods, the same measurements were also carried out with the ginseng and the saline groups without stress exposure (serving as control). Results obtained were as follows. 1. Administration of ginseng does depressed the decrease of the tolerance, body weight, visceral organ weight, basal metabolism rate, the number of erythrocyte, hemoglobin value, hematocrit ratio and the A/G ratio in the mice and rats exposed to various stress. 2. The change of the rectal temperature, eosinophile counts, total serum protein content and the content of adrenal ascorbic acid of ginseng group that exposured to various stress facilitates the reaction to, and accelerates the recovery from the stress. 3. Even after hypophysectomy which served the link between the central and the peripheral portion of the stress mechanism, the adrenal ascorbic acid content of ginseng group decreased significantly more than that of the saline group 30 min. after administration of ACTH, while the value approached the normal level significantly closer in the ginseng group than in the saline group 1 and 2 hr after ACTH administration. Judging from the above results, it is concluded that administration of ginseng extract tolerated the experimental animals under the environment of stressfu1 stmuli, although the ginseng has no significant influence upon the stress mechanism in the absence of stressful stimuli. The site of action of the ginseng appears to be in the peripheral portion of the stress mechanism.