• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 1995.11a
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• pp.49-70
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• 1995

콜레스테롤은 성호르몬, 스테로이드 호르몬, 비타민 D, 담즙산 및 다른 체내화합물에 존재하는 생명에 필수적인 물질이며, 특히 세포막에는 이의 안정적인 기능수행을 위해 일정량의 콜레스테롤이 반드시 존재해야 한다. 이러한 중요성 때문에 우리의 몸안에는 완전히 음식물의 섭취에 의한 공급에 의존하지 않고서도 필요에 따라 체조직의 온전한 기능수행을 위해 즉시 이용될 수 있는 충분한 양의 콜레스테롤이 존재한다. 따라서 체내에서 자체적으로 합성되는 콜레스테롤의 양은 음식물을 통해 흡수되는 양보다 일반적으로 훨씬 높다. 매일 우리의 체내에서는 약 1,500mg 정도의 콜레스테롤이 합성되는데, 주로 간세포에서 만들어지며, 소장세포에서도 일부 합성이 이루어진다. 식단(食單)의 구성에 따라 물론 차이는 있으나, 우리가 매일 음식물을 통해 섭취하는 콜레스테롤의 양은 평균 300~700mg 정도이다 .이중 소장을 통해 흡수될 수 있는 양은 50% 정도에 불과하여 대부분 식사를 통해 흡수되는 콜레스테롤의 양은 실제적인 의미에서 그리 큰 비중을 차지하지 않는다. 대부분의 건강한 사람은 혈액내 콜레스테롤의 수준이 항상 정상적인 범위내에서 유지될 수 있도록 기능적인 체내 Feed-back 기작을 유지하고 있다. 음식물을 통한 식이(食餌)콜레스테롤의 섭취량이 많을 경우에는 이 물질의 장관(腸管)내 흡수율이 낮아지고, 체내 콜레스테롤의 합성량 역시 저하된다. 이러한 방법으로 대부분의 건강한 사람은 음식물을 통한 많은 양의 식이 콜레스테롤 섭취에 대해 효율적으로 보상하는 체내기작을 갖게 되어 혈중 콜레스테롤 수준이 필요 이상 높아지는 것을 막게 된다. 물로 s이러한 보상작용(補償作用)은 사람에 따라 일정하지는 않다. 최근의 연구결과에 의하면, 건강한 사람들의 약 60%정도는 하루에 3개 정도의 달걀에 포함되어 있는 양 정도의 콜레스테롤을 추가적으로 보상시킬 수 있다고 하는데, 이는 달걀 이외의 음식물에서도 섭취되는 콜레스테롤 양을 감안할 때 하루 총 1,000~1,500mg에 해당하는 양이다. 뿐만 아니라 이중 일부 사람들은 일반적인 식단 하에서 6개의 달걀을 추가하여 섭취하여도 혈중 콜레스테롤 수준이 높아지지 않는다고 한다. 여러 나라에서 아직도 일률적으로 권장되는, 음식물을 통한 일당 콜레스테롤 섭취량을 최고 300mg으로 제한해야 한다는 것은 건강인에 있어서는 앞에서 언급한 바와 같은 생리적인 피이드-백 기작으로 말미암아 혈중 콜레스테롤 수준을 저하시키지 못하거나 미미한 정도에 불과하다. 혈중 콜레스테롤 수준이 정상적인 범위인 180~240 mg/dl에 해당하는 대부분의 건강인에게도 콜레스테롤이 많이 함유된 달걀이나 기타 축산물을 이용한 식품의 지속적인 섭취를 적극 피하도록 권장하는 것은 국민보건상 별로 큰 위미가 없다고 생각한다. 왜냐하면 이로 말미암아 국민 건강상 문제점이 크게 향상되었다는 연구보고는 아직 발견되지 않고 있기 때문이다. 더욱이 동물성 콜레스테롤 다량 함유식품인 달걀, 우유, 유제품 및 육류 등의 섭취를 꺼리게 되면 이들 식품들이 영양생리학상 매우 중요한 양질의 영양소를 많이 함유하고 있기 때문에 여러 중요한 필수 영양소의 공급상태를 뚜렷히 감소시키게 된다. 병적으로 혈중 콜레스테롤의 수준이 높은 사람은 관상성 심장병의 발병 내지는 심장경색에 의한 사망에 대한 통계학적 위험성이 증가된다. 고콜레스테롤 혈증(청, 중년층의 경우 260mg /dl 이상) 환자중 많은 사람들은 대부분 음식물을 통한 다량의 콜레스테롤 섭취에 의해 혈중 콜레스테롤 수준이 높아진 것이 아니고, 주로 유전적인 콜레스테롤 대사 결함에 그 원인이 있다고 한다. 이런 환자들의 경우에는 콜레스테롤 및 지방함량이 낮은 음식물만 계속적으로 섭취한다고해서 혈중 콜레스테롤의 수준을 만족할만한 정도까지 낮출 수 있는 것은 아니기 때문에 주로 의학적 약물투여에 의한 치료법을 적용한다. 식이성 고콜레스테롤 증상을 보이는 사람들에 있어서는 음식물의 섭취방법을 조절해 줄 필요가 있는데, 가장 효과적인 식이요법은 체중을 정상적인 수준으로 조절하는데 있다. 이러한 환자의 경우는 지방을 통한 열량 섭취량을 총열량의 30% 정도 수준까지 감소시키는 것이 좋으며, 팔미틴산의 함량이 높은 지방의 섭취는 가능하면 삼가는 것이 좋다. 단순 및 고도 불포화지방산의 함량이 높은 지방의 섭취는 혈중 콜레스테롤의 수준을 한 포인트 정도 낮추는데 추가적으로 기여할 수 있다. 최근의 연구에 의하면, 단순 불포화 지방산인 올레인산을 많이 함유하고 있는 올리브 기름이 특히 혈중 콜레스테롤 수준에 대한 유리한 효과를 나타낸다고 하는데, 이는 오로지 혈액내 LDL-Cholesterol을 감소시키는 작용에 기인한다. 이에 반해 고도 불포화지방산인 리놀산은 저밀도지단백질 부분 외에도 심장 보호성(心臟 保護性) HDL-부분까지도 저하시키게 된다. 따라서 특수하게 리놀산을 강화시켜 제조한 마아가린이나 이와 유사한 기름을 이용한 리놀산 강화식품의 섭취는 이러한 이유 외에도 일정한 부작용이 알려져 있어 더 이상 강하게 추천되지 않고 있다. 만일 이러한 식이조절에도 불구하고 혈중 콜레스테롤 수준이 원하는 정도까지 떨어지지 않을 경우, 물론 콜레스테롤의 섭취를 최저로 제한할 수 있는 방법을 꾸준히 시도해 봐야 하나 일반적으로 미미한 정도의 효과만을 가져온다. 유전 및 식이와 관계되는 사항 외에도 추가적으로 고려해야 할 점은, 혈중 콜레스테롤 수준은 나이, 성별, 스포츠, 흡연, 스트레스 및 음주 등과 같은 요인에도 결정적인 영향을 받는다는 사실이다. 물론 현재까지 과도하게 증가된 혈중 콜레스테롤 수준을 저하시킴으로써 전체 국민의 사망률을 현저하게 낮추고 평균수명을 연장시켰다는 증거는 발견되지 않고 있다. 왜냐하면 단독 식이 요법을 통한 해당 연구들이 현재까지 뚜렷한 긍정적인 결과를 제시하지 못하고 있기 때문이다. 의약품의 투여로 심장경색 및 이로 인한 사망을 감소시킬 수 있었다는 보고는 여러 연구결과들에서 보여주고 있으나, 그대신 다른 질병 및 암에 의한 사망률 역시 동시에 증가되었다고 한다. 이러한 이유로 말미암아 콜레스테롤 저하요법에 있어서 본래의 치료목적 이외의 위험성에도 항상 주의해야할 필요성이 존재한다는 사실을 주지해야 한다.

• Journal of The Korean Association For Science Education
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• v.19 no.4
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• pp.604-621
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• 1999

We analyze the admission test problems used in 1998 at the Science Education Center for Gifted Youth at Kyungpook National University (SECGY, KNU). The test consists of two parts, an evaluation of the scientific thinking skills and an evaluation of the achievement for Mathematics and Sciences, the former of which includes evaluations of scientific process skills and logical thinking skills. The problems for the test of scientific thinking skills were developed and standardized by the Korea Education Development Center, while those of the achievement for Mathematics and Sciences were made at SECGY. We calculate the indices of the difficulty and discrimination for each problem to determine whether or not the test is appropriate to apply for selecting number of gifted students among the recommended students from 389 middle schools in Taegu-city and Kyungsang-pook-do Province. We find that both indices of most problems for the test of scientific thinking skills were out range of the appropriate level and. moreover, even those problems which fall into the appropriate range showed very low efficiencies for distractors. We, thus, conclude that the problems of the test of scientific thinking skills are inappropriate to use as a test for admission to SECGY. On the other hand, the problems of the achievement test showed extreme results; the Mathematics problems appeared to be too difficult, whereas the Physics problems appeared too easy. However, overall scores showed a normal distribution, indicating that those problems played crucial role in selecting gifted students. We finally propose several suggestions in developing the test problems and in selecting students at the SECGY.

• Korean Journal of Weed Science
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• v.30 no.3
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• pp.291-299
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• 2010

Cyhalofop-butyl and penoxsulam, known for respective acetyl CoA carboxylase (ACCase) and acetolactate synthase (ALS) inhibitor, have been widely using as a post-emergence foliar application for many years in wet-seeded rice field in Korea. Since 2009, control of Echinochloa oryzoides with cyhalofop-butyl and penoxsulam was no longer satisfactory. Greenhouse and experiment in rice field were conducted to confirm E. oryzoides resistance to ACCase and ALS inhibitors and to compare herbicide treatments for control of the resistant E. oryzoides to ACCase and ALS inhibitors. Three resistant E. oryzoides to ACCase and ALS inhibitors accessions were tested for levels of resistance to cyhalofop-butyl and penoxsulam, base on survival rate. Iksan and Kimje accessions were not any affected to the survival by treatment with recommended doses of two herbicides tested. Buan accession displayed an intermediate response of 62 and 72% survival at recommended doses of cyhalofop-butyl and penoxsulam, respectively. Survival rates to herbicides mixed with ACCase and ALS inhibitors at 3.5 leaf stage of E. oryzoides was over 80%. Benzobicyclon+fentrazamide+bensulfuron SC, benzobicyclon+mefenacet+bensulfuron SC, benzobicyclone +cafenstrole+pyrazosulfuron-ethyl GR controlled effectively by 2 leaf stage of resistant E. oryzoides to ACCase and ALS inhibitors. In the field experiment, single treatment of benzobicyclon+ fentrazamide+bensulfuron SC and benzobicyclon+mefenacet+bensulfuron SC failed to control E. oryzoides, but squential treatment of benzobicyclon+thiobencarb SE and benzobicyclon+ mefenacet+ bensulfuron SC controlled effectively it in rice infant seedling culture with machine. Our results suggest that resistant E. oryzoides to ACCase and ALS inhibitors had not developed multiple resistance to herbicides with different modes of action. In particular, cafenstrole, fentrazamide, mefenacet were effective control measures.

• Journal of radiological science and technology
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• v.33 no.1
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• pp.19-24
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• 2010

The aim of this study was to evaluate the change of bone mineral density according to distal radius rotation and the correlations of the lowest BMD measured by DXA at the lumba versus distal radius. The eleven males were projected distal radius by DR X-ray and the measurement of BMD by DXA of the appropriate position of the forearm were performed on 21 males. The healthy 11 and 21 volunteers without any history of operations, anomalies, or trauma were enrolled. The experiment was performed by two methods. First, The DR X-ray was measured distal radius of 11 males in pronation and supination with three, six and nine degrees, including a neutral position. The ROI was measured by the m-view program on the PACS monitor. Second, The DXA was measured distal radius of 21 males in pronation and supination with five and ten degrees, including a neutral position to evaluate the changes of BMD according to the rotation. A correlation of the BMD in the distal radius with BMD that lumbar spine was performed, along with analysis of the data by SPSS 12.0v. The mean rotation angle of the distal radius about eleven males DR X-ray measured $7^{\circ}$ of pronation (82%, n = 9), $6^{\circ}$ of supination and $0^{\circ}$ of neutral of (9%, n = 1), The total average rotation angle in 11 male was $5.1^{\circ}$ of pronation. The rotation angle of the distal radius about twenty one males on DXA measured $7.2^{\circ}$ of pronation (43%, n = 9), $7^{\circ}$ of supination (24%, n = 5), and $0^{\circ}$ of neutral (33%, n = 7), The total average rotation angle in 21 people was $4.1^{\circ}$ of pronation. The correlation of the analysis of lumba and distal radius were r = 3.0, p = 0.18. consequently, The correlation was not significance. Because BMD of lumba was not coverd for BMD of the distal radius, with a neutral position, Pronation is needed for BMD in the distal radius with the rotation angle measuring at the lowest BMD. the rotation angle about five degrees of pronation of the distal radius is recommended.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.345-350
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• 1991

Rough rice samples of Chucheongbyeo, Bongkwangbyeo and Hwaseongbyeo were collected by the National Agricultural Products Inspection Office. Drying methods of rough rice were sun drying and forced ventilation drying by an oven dryer and temperature of the oven dryer was set to 43, 60, 70, or 8$0^{\circ}C$. Moisture content of samples was reduced from ca. 20% to 15% at the end of drying, and additionally to 12.5 % for the drying at 8$0^{\circ}C$. Characteristics related to rice grain quality, milling recovery, ratio of broken and cracked rices, percentage of germination, and sensory scores of the cooked rices were evaluated. Yielding percentage of brown rice and polished rice remarkably decreased by drying at 8$0^{\circ}C$. Percentages of cracked rice and broken rice were within the criterion of the second grade government brown rice (20%) only in the sun dried and the rices dried at 43$^{\circ}C$, on the basis of damaged rice, opaque kernel rice and colored rice. Broken rice percentage of the polished rice was within the criterion for the standard of government rice (5%) in the sun dried and the rices dried at 43$^{\circ}C$. Germination percentage of rough rice was higher than 80% in sun drying and drying at 43$^{\circ}C$, but remarkably decreased by drying rice at 6$0^{\circ}C$ and over. Sensory palatability of the cooked rice decreased with increase in drying temperature. The present governmental method of judging rough rice on the basis of moisture content and appearance of the rough rice appears to be improved to include the ratio of broken and cracked rices.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.345-351
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• 2015

Purpose: The purpose of this study was to evaluate the proper axial thickness of zirconia abutment applied to implant in the anterior region. Materials and methods: Zirconia abutments were prepared at different axial wall thickness by processing pre-sintered zirconia blocks via CAD/CAM to obtain equal specimens. The abutments were each produced with a thickness of 0.5 mm (Group 1), 0.8 mm (Group 2), 1.2 mm (Group 3), or 1.5 mm (Group 4). The implant used in this study was a external connection type one (US, Osstem, Pussan, Korea) product and the zirconia abutment was prepared via replication of a cemented abutment. The crowns were prepared via CAM/CAM with a thickness of 1.5 mm and were cemented to the abutments using $RelyX^{TM}$ UniCem cement. A universal testing machine was used to apply load at 30 degrees and measure fracture strength of the zirconia abutment. Results: Fracture strength of the abutments for Group 1, Group 2, Group 3, and Group 4 were $236.00{\pm}67.55N$, $599.00{\pm}15.80N$, $588.20{\pm}33.18N$, and $97.83{\pm}98.13N$, respectively. Group 1 showed a significantly lower value, as compared to the other groups (independent Mann-Whitney U-test. P<.05). No significant differences were detected among Group 2, Group 3, and Group 4 (independent Mann-Whitney U-test. P>.05). Conclusion: Zirconia abutment requires optimal thickness for fracture resistance. Within the limitation of this study, > 0.8 mm thickness is recommended for zirconia abutment in anterior implants.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.1
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• pp.36-42
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• 2007

To compare the survival rate of periodontal ligament cells preserved in storage media with good availability at the time of an avulsion injury, periodontal ligament cells were incubated in ${\alpha}-MEM$ culture medium containing 10% FBS in condition of $37^{\circ}C$, 5% $CO_2$. These cells were then cultured in HBSS, ${\alpha}-MEM$, milk(S co., P. co.) and tap water at the temperature of 4, 25, $37^{\circ}C$ each in 60 min. The groups were measured by MTT assay. The results were as follows : 1. Among the storage media at $4^{\circ}C$, ${\alpha}-MEM$ and P-milk had the highest preserving ability of periodontal ligament cells, while that of HBSS S-milk and tap was low in order. 2. Among the storage media at $25^{\circ}C$, ${\alpha}-MEM$ had the highest preserving ability of periodontal ligament cells, while that of P-milk, HBSS, S-milk, tap water was low in order. 3. Among the storage media at $37^{\circ}C$, the preserving ability of periodontal ligament cells was very high in ${\alpha}-MEM$, P-milk, HBSS and S-milk, it's lowest in tap water. 4. The preserving ability of periodontal ligament cells in ${\alpha}-MEM$ was high at $4^{\circ}C$ and it's low in order of $25^{\circ}C$, $37^{\circ}C$, but in HBSS was high at $4^{\circ}C$ and it's low at $25^{\circ}C$, $37^{\circ}C$ 5. The preserving ability of periodontal ligament cells in S-milk and P-milk was high at $4^{\circ}C$, $25^{\circ}C$ and it s low at $37^{\circ}C$. In conclusion, HBSS is the storage medium of choice in an avulsion, but in this study it is preferable to choose milk at $4^{\circ}C$ for tooth since it is easy to get and affect cell viability.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.25-32
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• 2011

The number of patients requesting services of pediatric dental clinics has been steadily increasing in South Korea. The pediatric dental clinics are comprised of hospital-based clinics and local clinics. The purpose of this study was to analyze new-patient distribution and to survey the motives for visiting the department of pediatric dentistry at Seoul National University Dental Hospital(SNUDH), utilizing questionnaires for parents from May to July 2010. The results are as follows: 1. Age distribution showed that 0-3 year-olds formed the largest group of 29.3%. The average age of patients was 6.2 years old. 2. In the surveys for the parents, the major reason for visiting SNUDH was the referral from other clinics(30.6%). 3. The 75% of patients previously visited other clinics before visiting SNUDH. 1) The greater number of patients(52%) visited general practitioner's clinic than pediatric specialists(48%). 2) More than 90% of the patients visited SNUDH after visiting other clinics for reassuring diagnosis and referrals. 3) The crucial deterring factor of being treated at SNUDH was difficult accessibility.

• Korean Journal of Weed Science
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• v.14 no.3
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• pp.199-211
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• 1994

Butachlor applied pre-emergence at 3.6kg ai/ha inhibited the growth and developments of shoot of barnyardgrass under dry condition, whereas rice was unaffected. Growth of rice and barnyardgrass under water condition was severely inhibited by treatment of butachlor but that of transplanted rice was not affected. The inhibition rate was higher under water condition, in broadcast rice and direct seeded rice than under dry condition, drilled rice and transplanted rice, respectively. The major anatomical response of stem of barnyardgrass seedling to butachlor under dry condition were partial reduction in thickness and collapse of leaf sheath, while not in rice. Broadcast rice on soil under water condition appeared reduction and constriction of leaf primordia thickness, and barnyardgrass formed tubular-like leaves and showed inhibited elongation of apical meristem. On the other hand, transplanted rice did not show these responses.

• Korean Journal of Weed Science
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• v.14 no.3
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• pp.212-222
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• 1994

Thiobencarb retarded the growth of new leaves in only barnyardgrass under dry condition while under water condition the shoot growth of broadcast rice, and both shoot and root growth of barnyardgrass was considerably inhibited. Root elongation of rice and barnyardgrass was severely inhibited only under water condition, while that of transplanted rice was slightly inhibited. Inhibition of shoot and root growth in broadcast, drilled rice and barnyardgrass under water condition was much higher than that under dry condition, whereas the inhibition was less in transplanted rice than direct seeded rice. Microscopically, thiobencarb severely inhibited shoot growth and development of barnyardgrass by inducing tubular-like leaves. The cells of the shoot apices of treated barnyardgrass seedling under dry condition was vacuolated and irregularly arranged. Under water condition, leaf primordia of broadcast rice was constricted, barnyardgrass showed tubular-like leaves, inhibited apices elongation and vacuolated cells(visually lack cytoplasm).