• The Journal of the Korean Society for Microbiology
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• v.17 no.1
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• pp.67-74
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• 1982

Staphyylococci are responsible for over 80 per cents of the suppurative diseases encountered in medical practice. They cause most suppurative infections of the skin but may also invade and produce severe infections in any other parts of the body. In order to know the carrier rate of staphylococci between the parahospital workers and in the hospital workers, the author undertook isolation of S aureus from nasal cavity on 68 cases of freshmen, 31 cases of sophomores, and 37 cases of juniors in Busan National University, and 30 cases of nursing students, 30 cases of nurses, 30 cases of nurses in charge of operating room and 30 cases of doctors in Busan National University Hospital. The tested total cases were 256 cases which were 136 Cases in parahospital workers and which were 120 cases in hospital workers. The biochemical characters of S aureus strains isolated were studied on coagulase test, mannitol test, hemolysis test and sensitivity test to antimicrobial agents. The results obtained were as follows: 1. S aureus were isolated 49 cases(29.7%) from nasal cavity parahospital workers and were isolated 67 cases(55.8%) from nasal cavity on hospital workers. 2. Among 40 strains of S aureus isolated from parahospital worker's nasal cavity coagulase positive were 29 cases(72.1%), and coagulase negative were 11 cases(27.5%). And mannitol positive were 29 cases(72.5%), and mannitol negative were 11 cases(27.5%). 3. Among 67 strains of S aureus isolated from hospital worker's nasal cavity coagulase positive were 59 cases(88.1%), and coagulase negative were 8 cases(11.9%). And mannitol positive were 49 cases(73.1%), and mannitol negative were 18 cases(26.9%). 4. The hemolysis test of each erythocytes on coagulase and mannitol positive S aureus isolated were sensitive to rabbit(40 cases: 81.6%), guinea pig(26 cases: 53.6%), sheep(13 case: 26.5%), and were not sensitive to chicken and human erythrocytes, respectively. 5. The hemolysis test of each erythocytes on 10 strains of coagulase and mannitol negative S aureus isolated were not sensitive to all of, erythrocytes. 6. The sensitivity test to the various chemotherapeutic agents was almost sensitive to the strains isolated from parahospital workers, but was almost resistant to the strains isolated from hospital workers.

• Journal for History of Mathematics
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• v.2 no.1
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• pp.91-105
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• 1985

Though the tradition of Korean mathematics since the ancient time up to the "Enlightenment Period" in the late 19th century had been under the influence of the Chinese mathematics, it strove to develop its own independent of Chinese. However, the fact that it couldn't succeed to form the independent Korean mathematics in spite of many chances under the reign of Kings Sejong, Youngjo, and Joungjo was mainly due to the use of Chinese characters by Koreans. Han-gul (Korean characters) invented by King Sejong had not been used widely as it was called and despised Un-mun and Koreans still used Chinese characters as the only "true letters" (Jin-suh). The correlation between characters and culture was such that , if Koreans used Han-gul as their official letters, we may have different picture of Korean mathematics. It is quite interesting to note that the mathematics in the "Enlightenment Period" changed rather smoothly into the Western mathematics at the time when Han-gul was used officially with Chinese characters. In Koryo, the mathematics existed only as a part of the Confucian refinement, not as the object of sincere study. The mathematics in Koryo inherited that of the Unified Shilla without any remarkable development of its own, and the mathematicians were the Inner Officials isolated from the outside world who maintained their positions as specialists amid the turbulence of political changes. They formed a kind of Guild, their posts becoming patrimony. The mathematics in Koryo is significant in that they paved the way for that of Chosun through a few books of mathematics such as "Sanhak-Kyemong, "Yanghwi - Sanpup" and "Sangmyung-Sanpup." King Sejong was quite phenomenal in his policy of promotion of mathematics. King himself was deeply interested in the study, createing an atmosphere in which all the high ranking officials and scholars highly valued mathematics. The sudden development of mathematic culture was mainly due to the personality and capacity of King who took any one with the mathematic talent onto government service regardless of his birth and against the strong opposition of the conservative officials. However, King's view of mathematics never resulted in the true development of mathematics per se and he used it only as an official technique in the tradition way. Korean mathematics in King Sejong's reign was based upon both the natural philosophy in China and the unique geo-political reality of Korean peninsula. The reason why the mathematic culture failed to develop continually against those social background was that the mathematicians were not allowed to play the vital role in that culture, they being only the instrument for the personality or politics of the King. While the learned scholar class sometimes played the important role for the development of the mathematic culture, they often as not became an adamant barrier to it. As the society in Chosun needed the function of mathematics acutely, the mathematicians formed the settled class called Jung-in (Middle-Man). Jung-in was a unique class in Chosun and we can't find its equivalent in China of Japan. These Jung-in mathematician officials lacked tendency to publish their study, since their society was strictly exclusive and their knowledge was very limited. Though they were relatively low class, these mathematicians played very important role in Chosun society. In "Sil-Hak (the Practical Learning) period" which began in the late 16th century, especially in the reigns of King Youngjo and Jungjo, which was called the Renaissance of Chosun, the ambitious policy for the development of science and technology called for the rapid increase of the number of such technocrats as mathematicians inevitably became quite ambitious and proud. They tried to explore deeply into mathematics per se beyond the narrow limit of knowledge required for their office. Thus, in this period the mathematics developed rapidly, undergoing very important changes. The characteristic features of the mathematics in this period were: Jung-in mathematicians' active study an publication, the mathematic studies by the renowned scholars of Sil-Hak, joint works by these two classes, their approach to the Western mathematics and their effort to develop Korean mathematics. Toward the "Enlightenment Period" in the late 19th century, the Western mathematics experienced great difficulty to take its roots in the Peninsula which had been under the strong influence of Confucian ideology and traditional Korean mathematic system. However, with King Kojong's ordinance in 1895, the traditonal Korean mathematics influenced by Chinese disappeared from the history of Korean mathematics, as the school system was changed into the Western style and the Western matehmatics was adopted as the only mathematics to be taught at the schools of various levels. Thus the "Enlightenment Period" is the period in which Korean mathematics sifted from Chinese into European.od" is the period in which Korean mathematics sifted from Chinese into European.pean.

• Analytical Science and Technology
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• v.24 no.2
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• pp.150-157
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• 2011

Aflatoxins are secondary metabolites of the molds of Aspergillus flavus and Aspergillus parasiticus. They are highly carcinogenic compounds and can affect a wide range of vegetable commodities such as cereals (especially corn), nuts, peanuts, fruits and oil seeds, in the field and during storage. In fact, oilseeds are often stored for weeks in conditions that promote the mould growth, and the possible consequent presence of aflatoxins in oilseeds can lead to their transfer in oil. In addition, aflatoxins can be found as a natural contaminant in multi-cereals and beans making baby food for infants and young-children. The objective of this study was to validate the liquid extraction method or develop an analytical method for edible oil and infant-children foods. Therefore, this study developed condition of extract for aflatoxins ($B_1$, $B_2$, $G_1$ and $G_2$) in edible oil using a high performance liquid chromatography with florescence detector (HPLC/FLD). Aflatoxins were extracted from edible oil samples by means of MSPD (Matrix solid phased dispersion), utilizing $C_{18}$ as dispersing material and purified by using immunoaffinity column. The gression line coefficients were above 0.999. The recoveries for aflatoxins ranged from 85.9 to 93.0%, and relative standard deviations were below 5.7%. The new developed method of aflatoxins effectively enhanced recoveries by using MSPD-Immunoaffinity column compared with liquid extraction. The analytical method for liquid extraction of aflatoxin was appropriate for infant-children food. Reviewing the current method, the recoveries of aflatoxins ($B_1$, $B_2$, $G_1$ and $G_2$) were 89.5~92.3%.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.129-150
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• 1985

The present investigation was conducted to provide a systematic approach necessary to establish an integrated insect pest management program of barley in Korea. Some ecological surveys on insect pests of barley have been undertaken at the field of Experimental Station, Ky$\check{o}$ngbuk Provincial Office of Rural Development as a fixed point survey area, and at 23 localities for round survey throughout southern and central Korea from 1983 to 1984. Previously known insects injurious to barley in Korea were revised and the population dynamics of 10 dominant harmful species were analyzed according to either 24 localities or 25 cultivars respectively by using several sampling methods of net sweeping, black light traps, yellow water pan traps and visual counting. As the results, a total of 94 species belonging to 77 genera under 32 families are known to be injurious to barley, among them 20 species are newly added here. In the population density level, the dominant species were disclosed as Laodelphax striatellus (43.1 %), Macrosiphum avenae(27.0 %), Rhopalosiphum padi(6.5 %), R. maidis(5.4 %), Psammolettix strialus(2.7 %), Chlorops oryzae(2.2 %), Agromyza albipennis(2.1 %) Phyllotreta nemorum(1.4 %), Chaetoenema cylindrica(1.0 %), Dolycoris baccarum(1.0 %) in order. For the general abundance of major insect pests, it was highest in the cultivar P'aldal whereas lowest in Milyang #22. There were tendencies that Psammotettix striatus, Dolycoris baccarum, Phyllotreta nemorum and Chaetocnema cylindrica represented a maximum increase in the beginning of June, while Chlorops oryzae and Agromyza albipennis showed in the middle of May but aphids were in the end of May. In the dominance of natural enemies, Nabis stenoferus occupied 21.4 % and Propylaea japonica 9.6 %.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.8 no.3
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• pp.185-195
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• 1975

The comparative studies Were conducted with respect to the artificial spawning early embryonic development, metamorphosis and growth of two species Meretrix lusoria and Cyclina sinensis collected from Inchon, Anmyon island and Buan areas from 1969 to 1974. The highest rate of artificial spawning of M. lusoria, which treated with a dilute ammoniun hydroxide(4/100-5/100N)-seawater solutions, was $25.0-33.3\%$, whereas in C. sinensis the rate of spawning was lower than that of M, lusoria under the similar experimental conditions$(12.5-19.0\%)$. However, the rate of artificial spawning of C. sinensis increased $40\%$ by repeated thermal stimulation. The rate of artificial fertilization of M. lusoria and C. sinensis showed highest value from those individuals which were treated with 1/1000N $NH_4OH$ solution. Their fertilized eggs, then, showed a normal development in the 1/1000N $NH_4OH$ solution. In the early embryonic development of M. lusoria and C. sinensis, the appearance of each of polar body, trochophore and D-shaped veliger were observed around 50min. 5-6 hours, and 23 hours after artificial fertilization respectively. The larval shell lengths of M. lusoria reached to $109,5{\pm}0.7\mu,\;144.6{\pm}1.3\mu$ and $208.0{\pm}0.0\mu$ around, 1, 11 and 20 days, after fertilization respectively. The larval shell lengths of C. sinensis reached to $110.5{\pm}0.6\mu,\;147.8{\pm}1.7\mu,\;and\;235.0{\pm}0.0\mu$ around 1, 10 ana 20 days, after fertilization respectively. The correlations of relative growth rate between the shell length(L) and sell height(H) found by the following simple formula from D-shaped veliger to metamorphosing stage. H=0.77L+6.82 for M. lusoria H=0.75L+8.50 for C. sinensis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.4
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• pp.179-183
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• 1980

The efficiency of energy transfer by a population of the farmed pacific oyster, Crassostrea gigas was studied during culture period of 10 months July 1979-April 1980, in Geoje-Hansan Bay near Chungmu City. Energy use by the farmed oyster population was calculated from estimates of half-a-month unit age specific natural mortality rate and data on growth, gonad output, shell organic matter production and respiration. Total mortality during the culture period was estimated approximate $36\%$ from data on survivor individual number per cluster. Growth may be dual consisted of a curved line during the first half culture period (July-November) and a linear line in the later half period (December-April). The first half growth was approximated by the von Bertalanffy growth model; shell height, $SH=6.33\;(1-e^{0.2421(t+0.54)})$, where t is age in half-a-month unit. In the later half growth period shell height was related to t by SH=4.44+0.14t. Dry meat weight (DW) was related to shell height by log $DW=-2.2907+2.589{\cdot}log\;SH,\;(2, and/or log $DW=-5.8153+7.208{\cdot}log\;SH,\;(5. Size specific gonad output (G) as calculated by condition index of before and after the spawning season, was related to shell height by $G=0.0145+(3.95\times10^{-3}{\times}SH^{2.9861})$. Shell organic matter production (SO) was related to shell height by log $SO=-3.1884+2.527{\cdot}1og\;SH$. Size and temperature specific respiration rate (R) as determined in biotron system with controlled temperature, was related to dry meat weight and temperature (T) by log $R=(0.386T-0.5381)+(0.6409-0.0083T){\cdot}log\;DW$. The energy used in metabolism was calculated from size, temperature specific respiration and data on body composition. The calorie contents of oyster meat were estimated by bomb calorimetry based on nitrogen correction. The assimilation efficiency of the oyster estimated directly by a insoluble crude silicate method gave $55.5\%$. From the information presently available by other workers, the assimilation efficiency ranges between $40\%\;and\;70\%$. Twenty seven point four percent of the filtered food material expressed by energy value for oyster population was estimated to have been rejected as pseudofaeces : $17.2\%$ was passed as faeces; $35.04\%$ was respired and lost as heat; $0.38\%$ was bounded up in shell organics; $2.74\%$ was released as gonad output, $2.06\%$ was fell as meat reducing by mortality. The remaining $15.28\%$ was used as meat production. The net efficiency of energy transfer from assimilation to meat production (yield/assimilation) of a farm population of the oyster was estimated to be $28\%$ during culture period July 1979-April 1980. The gross efficiency of energy transfer from ingestion to meat production (yield/food filtered) is probably between $11\%\;and\;20\%$.

• Journal of Nutrition and Health
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• v.40 no.5
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• pp.451-462
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• 2007

This study was conducted to investigate breakfast consumption pattern in relation to diet quality and health outcomes of Korean adults. Data are from 2001 National Health and Nutrition Survey. Dietary information of 3406 adults aged $30{\sim}49$ years and their socio-demographic characteristics, blood lipid profile, fasting blood glucose, blood pressure, anthropometric measurements were analyzed. According to the breakfast consumption of the subjects, they were classified to breakfast skippers and eaters and the eaters' breakfast staple types were defined as RICE, BREAD, NOODLES, MIXED (mixed types including several grain-based dishes), and OTHERS. The proportions of breakfast consumption patterns were 18.4% for skippers, 71.1% for RICE, 2.6% for BREAD, 1.6% for NOODLES, 4.0% for MIXED, and 2.4% for OTHERS. Breakfast skippers had lower daily nutrients intake than breakfast eaters but their health outcomes did not differ from those of eaters. Instead, men with BREAD pattern had higher blood cholesterol and women in NOODLE pattern had higher blood glucose and lower HDL cholesterol. The BREAD pattern breakfast had higher energy contribution from fat and lower nutrient densities and the subjects in BREAD pattern had higher level of household income. Men's BREAD pattern breakfast consisted more animal products than that of women. There was high probability of undernutrition among women in NOODLE pattern and their mean household income was the lowest. From these results, in Korea, breakfast staple types have different food patterns and there was need for developing healthy food patterns appropriate to each staple type. The breakfast consumption pattern had influences on nutrient adequacy of the diet and health outcomes and seemed to represent socio-economic status. These could be used in doing nutrition education in community.

• Journal of Nutrition and Health
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• v.49 no.5
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• pp.335-346
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• 2016

Purpose: This study was conducted to conduct dietary assessment of Korean adults according to intake of Korean soup and stew. Methods: To accomplish this study, 20,926 adults aged 19 yr or higher who participated in the dietary intake survey (24 h recall method) were analyzed from the data of the 2011~2014 Korea National Health and Nutrition Examination Survey (KNHANES). The items included in the soup and stew were guk, tang, jjigae, jijimi, and jeongol. Results: Intakes of soup and stew of subjects were divided into quartiles; intake range by quartile was Q1: < 22.96 g, Q2: 22.96~98.75 g, Q3: 98.75~212.23 g, and Q4: $${\geq_-}212.24g$$. In the case of the Q4 group, male, married, employed, higher educated, and high income subjects showed increased intakes of soup and stew. In addition, sodium intake among nutrient intakes increased from 3,849.04 mg in Q1 group to 5,363.57 mg in Q4 group. Intakes of cereals/grains, potatoes/starches, legumes, seeds/nuts, vegetables, mushrooms, fruits, meat, fishes/shell fishes, milks/dairy products, oils/fats, and seasonings among all foods significantly increased from Q1 group to Q4 group. Lastly, in the multivariable regression analysis, male, higher age, married, eating breakfast, consumption of snacks, prepared meals from home/institution, average eating-out frequency per week, energy consumption, and sodium intake related parameters increased intake of Korean soup and stew. Conclusion: Excessive intake of sodium was related to high blood pressure and metabolic syndrome. Thus, there are needs to improve dietary guidelines and nutrition education for balanced intake of soup and stew.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.513-523
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• 2017

We evaluated the viability of phytoplankton along the salinity gradient in the flood and ebb tides of spring tide of February and the ebb tide of neap tide of March 2017 in the Seomjin River Estuary. Additional laboratory experiments were also conducted to determine the reason of the pH changes along the salinity gradient using the field natural sample in February. In field, saltwater was well mixed at downstream vertically and the salinity gradient was horizontally appeared toward upstream of freshwater zone. There were strong negative correlations between salinity and nutrient (nitrate + nitrite R=0.99, p<0.001, and silicate R=0.98, p<0.001), implying that those two nutrients of freshwater origin were gradually diluted with mixing the saltwater. On the other hands, relatively high phosphate concentration was kept in the stations of saltwater over 15 psu, indicating that it was caused by resuspended sediments of Gwangyang Bay and downstream by tidal water mixing.Among phytoplankton community structure in winter, Eucampia zodiacus have occupied to be c.a. 70 % in the most stations. Based on the field survey results for survivability of phytoplankton by phytoPAM instrument, there was positive correlations between salinity and chlorophyll a (R=0.82, p<0.001) and, salinity and active chlorophyll a (R=0.80, p<0.001), implying that the dominant marine diatom species may have significantly damaged in low salinity conditions of upstream. Also, maximum mortality rate of phytoplankton caused by low salinity shock was appered to be 75% in the upstream station. In particular, the pH in spring tides of February had tended to increase with high phytoplankton accmulated stations, suggesting that it was related with absorption of $CO_2$ by the photosynthesis of dominant diatom. In laboratory experiments, phytoplankton mass-mortality caused by low salinity shock was also occurred, which is confirmed with reducing the photosynthetic electron transport activity. Following the phytoplankton mass-mortality, bacteria abundance was significantly increased in 24 hours. As a result, the mass-proliferating bacteria can produce the $CO_2$ in the process of biodegradation of diatoms, which can lead to pH decrease. Therefore, marine phytoplankton species was greatly damaged in freshwater mixing area, depending on along the salinity gradient that was considered to be an important role in elevating and reducing of pH in Seomjin River Estuary.

• Microbiology and Biotechnology Letters
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• v.37 no.3
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• pp.248-257
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• 2009

The inhibitors against Vibrio harveyi quorum sensing (QS) signaling were developed by modifying the molecular structure of the major signal, N-3-hydroxybutanoyl-L-homoserine lactone (3-OH-$C_4$-HSL). A series of structural derivatives, N-(3-hydroxysulfonyl)-L-homoserine lactones (HSHLs) were synthesized by the solid-phase organic synthesis method. The in vivo QS inhibition by these compounds was measured by a bioassay system using the V. harveyi bioluminescence, and all showed significant inhibitory effects. To analyze the interaction between these compounds and LuxN, a 3-OH-$C_4$-HSL receptor protein of V. harveyi, we tentatively determined the putative signal binding domain of LuxN based on the sequence homology with other acyl-HSL binding proteins, and predicted the partial 3-D structure of the putative signal binding domain of LuxN by using ORCHESTRA program, and further estimated the binding poses and energies (docking scores) of 3-OH-$C_4$-HSL and HSHLs within the domain. In comparison of the result from this modeling study with that of in vivo bioassay, we suggest that the in silica interpretation of the interaction between ligands and their receptor proteins can be a valuable way to develop better competitive inhibitors, especially in the case that the structural information of the protein is limited.