• Sleep Medicine and Psychophysiology
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• v.5 no.1
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• pp.88-102
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• 1998

Objectives : We attempted to study obstructive sleep apnea symptoms prevalence and sleep apnea-associated factors in Korean rural adult population. Methods : In 1,441 adult subjects of three rural communities selected by cluster sampling, we administered an epidemiologic survey using questionnaire methods from July 14, 1996 to July 28, 1996. Results : 1) In 14.1% of the subjects, snoring was reported to occur almost daily and 2.9% of the subjects reported sleep apnea symptoms occurring almost daily. 2) Snoring and sleep apnea symptoms were found more frequently in males or in mid-aged group(45 - 64 years old) than in females or in younger- and older-aged groups, respectively. Compared with the subjects who have no snoring, the subjects who have snoring or sleep apnea symptoms had greater body mass index(BMI), waist-hip ratio, hemoglobin level, RBC count, and higher diastolic blood pressure. 3) Cigarette smoking and alcohol drinking more than once a week were significantly associated with suffering from sleep apnea symptoms. 4) In multiple logistic regression analysis, being male, mid-aged, and greater BMI were independently associated with the presence of snoring and sleep apnea symptoms. Conclusion : We conclude that, in the Korean rural adult population, males or mid-aged group suffers more from snoring and sleep apnea symptoms than females or younger- and older-aged groups. In addition, being male, mid-aged, and greater BMI were significantly associated independently with the presence of snoring and sleep apnea symptoms.

• Korean Journal of Heritage: History & Science
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• v.52 no.2
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• pp.38-61
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• 2019

Up until the early twentieth century in Germany, there were two research trends: 1) emphasizing objectives and making detailed observations of archaeological artifacts and sites, 2) tracing the remains of specific nations or ethnic groups and defining their temporal-spatial boundaries by conducting research on material culture in terms of nationalism or ethnocentrism. After the Second World War ended and Germany was divided, West German archaeology focused on observations of artifacts and sites, cataloging them, and doing research on chronology and distribution following their own traditional methodologies. East German archaeology attempted to prove the developing process of history and its Marxist principles based upon material culture and to examine the historic value of inherent specific cultural heritage based on criteria regarding how it corresponded to socialism and contributed to the development of socialism. Nevertheless, East and West German archaeology shared traditional archaeological methods inherited from German archaeology since the nineteenth century, and contact between archaeologists in West and East Germany continued to a degree. Furthermore, East German archaeology produced significant archaeological achievements acknowledged by West German and European archaeologists. These facts provided the momentum to complete rapid incorporation of the archaeologies of West and East Germany in spite of a one-sided process imposed by West German archaeology. In the case of Korea, it seems necessary to make an effort to share common research history and traditions and to encourage mutual academic exchange (e.g. joint excavation and archaeological research). Furthermore, it is also imperative to have open-minded attitudes toward accepting substantial results and interpretations achieved by North Korean archaeologists under scrutiny when and where necessary, despite seeming to have been fossilized by Marxism and Juche ideology. Any efforts to narrow the gap in archaeological research and conservation of cultural heritage between the archaeologies of South and North Korea should be made immediately. The case of Germany demonstrates how such a project could proceed efficaciously.

• Analytical Science and Technology
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• v.36 no.6
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• pp.291-299
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• 2023

The benzo[a]pyrene in edible oils is extracted using methods such as Liquid-liquid, soxhlet and ultrasound-assisted extraction. However these extraction methods have significant drawbacks, such as long extraction time and large amount of solvent usage. To overcome these drawbacks, this study attempted to improve the current complex benzo[a]pyrene analysis method by applying the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method that can be analyzed in a simple and short time. The QuEChERS method applied in this study includes extraction of benzo[a]pyrene into n-hexane saturated acetonitrile and n-hexane. After extraction and distribution using magnesium sulfate and sodium chloride, benzo[a]pyrene is analyzed by liquid chromatography with fluorescence detector (LC/FLR). As a result of method validation of the new method, the limit of detection (LOD) and quantification (LOQ) were 0.02 ㎍/kg and 0.05 ㎍/kg, respectively. The calibration curves were constructed using five levels (0.1~10 ㎍/kg) and coefficient (R²) was above 0.99. Mean recovery ratio was ranged from 74.5 to 79.3 % with a relative standard deviation (RSD) between 0.52 to 1.58 %. The accuracy and precision were 72.6~79.4 % and 0.14~7.20 %, respectively. All results satisfied the criteria ranges requested in the Food Safety Evaluation Department guidelines (2016) and AOAC official method of analysis (2023). Therefore, the analysis method presented in this study was a relatively simple pretreatment method compared to the existing analysis method, which reduced the analysis time and solvent use to 92 % and 96 %, respectively.

• The Journal of Natural Sciences
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• v.4
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• pp.103-142
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• 1991

These studies were carried out to select somatic hybrid using selectable marker genes of Nicotiana glauca transformed by NPTII gene and Solanum tuberosum transformed by T- DNA, and to study characteristics of transformant. The results are summarized as follows. 1. Crown gall tumors and hairy roots were formed on potato tuber disc infected by A. tumefaciens Ach5 and A. rhizogenes ATCC15834. These tumors and roots could be grown on the phytohormone free media. 2. Callus formation from hairy root was prompted on the medium containing 2, 4 D 2mg/I with casein hydrolysate lg/l. 3. The survival ratio of crown gall tumor callus derived from potato increased on the medium containing the activated charcoal 0. 5-2. 0mg/I because of the preventions on the other hand, hairy roots were necrosis on the same medium. 4. Callus derived from hairy root were excellently grown for a short time by suspension culture on liquid medium containing 2, 4-D 2mg/I and casein hydrolysate lg/l. 5. The binary vector pGA643 was mobilized from E. coli MC1000 into wild type Agrobacteriurn tumefaciens Ach5, A. tumefaciens $A_4T$ and disarmed A. tuniefaciens LBA4404 using a triparental mating method with E. ccli HB1O1/pRK2013. Transconjugants were obtained on the minimal media containing tetracycline and kanamycin. pGA643 vectors were confirmed by electrophoresis on 0.7% agarose gel. 6. Kanamycin resistant calli were selected on the media supplemented with 2, 4-D 0.5mg/1 and kanamycin $100\mug$/ml after co- cultivating with tobacco stem explants and A. tumefaciens LBA4404/pGA643, and selected calli propagated on the same medium. 7. The multiple shoots were regenerated from kanamycin resistant calli on the MS medium containing BA 2mg/l. 8. Leaf segments of transformed shoot were able to grow vigorusly on the medium supplemented with high concentration of kanamycin $1000\mug$/ml. 9. Kanamycin resistant shoots were rooting and elongated on medium containing kanamycin $100\mug$/ml, but normal shoot were not. 10. For the production of protoplast from potato calli transformed by T-DNA and mesophyll tissue transformed by NPTII gene, the former was isolated in the enzyme mixture of 2.0% celluase Onozuka R-10, 1.0% dricelase, 1.0% macerozyme. and 0.5M mannitol, the latter was isolated in the enzyme mixture 1.0% Celluase Onozuka R-10, 0.3% macerozyme, and 0.7M mannitol. 11. The optimal concentrationn of mannitol in the enzyme mixture for high protoplast yield was 0.8M at both transformed tobacco mesophyll and potato callus. The viabilities of protoplast were shown above 90%, respectively. 12. Both tobacco mesophyll and potato callus protoplasts were fused by using PEG solution. Cell walls were regenerated on hormone free media supplemented with kanamycin after 5 days, and colonies were observed after 4 weeks culture.