• 대한치과교정학회지
• /
• 제46권3호
• /
• pp.163-170
• /
• 2016

Objective: The aims of this study were to investigate a simple method for assessing anterior-posterior jaw relationships via cone-beam computed tomography (CBCT) images taken in the natural head position (NHP) relative to the nasion true vertical plane (NTVP), and measure normative data in Korean adults with normal profiles. Methods: Subjects were selected from patients presenting for third molar extraction and evaluated as having normal profiles by three examiners. The CBCT images of 80 subjects (39 males, 41 females) were taken in the NHP according to Solow and Tallgren's method. Linear measurements of the A-point, B-point, and Pog were calculated relative to the NTVP. Student's t -test was used to assess sexual differences in these measurements. Results: The mean linear measurements of the A-point, B-point, and Pog relative to the NTVP were 0.18 mm (standard deviation [SD], 4.77 mm), -4.00 mm (SD, 6.62 mm), and -2.49 mm (SD, 7.14 mm) respectively in Korean males, and 1.48 mm (SD, 4.21 mm), -4.07 mm (SD, 6.70 mm) and -2.91 mm (SD, 7.25 mm) in Korean females respectively. There were no statistically significant differences between Korean males and females (p < 0.05). Conclusions: Three-dimensional CBCT analysis using the NTVP is a simple and reliable method for assessing anterior-posterior skeletal relationships.

• 교육시설
• /
• 제4권2호
• /
• pp.31-36
• /
• 1997

The Magnet Methodology is not the recording of knowledge, skills, techniques, and other information from the past, but creating a knowledge base using present issues of problems for students' and teachers' life-span development through the exploration of career choices and development. In short, it is the multi-cooperative information system for commensalism. It is the magnet program that connects various level of educational institutions under a certain theme and enables students to choose on their own. And this magnet program is being adminstered by the magnet school. And some regular schools provide magnet program as vocational educations and extra-curricular activities. Magnet program reflects the concept of desegregation which was proposed by the U.S. Federal Court decision against the racial conflict which had culminated in the 60s and 70s. Magnet program enables students to choose their own programs and schools, and gives teachers and students the opportunities to develop their teaching method and learning method. That's why magnet program is called continuous, future-oriented one. Teachers and students can also get fair judgement on their activities due to the voluntary magnet program. It mainly deals with practical issues, so it is very realistic to establish the multi cooperative information system including companies, homes, communities, or governments under these practical issues. The openness of magnet program is guaranteed not only by the characteristics of the program but also by the physical layout of the magnet schools. There are no doors and walls, and classrooms are facing one another and sharing all the opinions and information. This precisely corresponds to the concept of co-existence of eco-system and the interdisciplinary approach which is essential to solve our problems.

• Journal of Microbiology and Biotechnology
• /
• 제10권5호
• /
• pp.677-684
• /
• 2000

Pseudomonas sp. BK7, an alkalophile, displayed the highest growth and protease activity when grown in a fermenter which was controlled at a pH level of 9.0, and the enzyme production was significantly enhanced by the increase of agitation speed. Two forms of alkaline proteases (BK7-1 and BK7-2) were fractionated and purified to near homogeneity. Protease BK7-1 was purified through CM-Sepharose CL-6B and Sephadex G-75 column chromatographies, and Protease BK7-2 was purified through CM-Sepharose CL-6B, DEAE-Sepharose, and Sephadex G-75 column chromatographies. The molecular weights of proteases BK7-1 and BK7-2 determined by gel filtration chromatography were 20,700 and 40,800, respectively. The $K_m$ value, isoelectric point, and optimum pH of protease BK7-1 were 2.55 mg/ml, 11.0, and 11.0, respectively, whereas those of protease BK7-2 were 1.57 mg/ml, 7.2, and 10.0, respectively. Both proteases were practically stable in the pH range of 5-11. The optimum temperatures for the activities of both protease BK7-1 and BK7-2 were $50^{\circ}C$ and $45^{\circ}C$, respectively. About 56% of the original protease BK7-2 activity remained after being treated at $50^{\circ}C$ for 30 min but protease BK7-1 was rapidly inactivated at above $25^{\circ}C$. Both proteases were completely inhibited by phenylmethane sulfonyl fluoride, a serine protease inhibitor. Protease BK7-2 was stable against EDTA, EGTA, STP, and detergents such as SDS and LAS, whereas protease BK7-1 was found to be unstable.

• Biomaterials and Biomechanics in Bioengineering
• /
• 제3권2호
• /
• pp.105-114
• /
• 2016

The purpose of this study is to evaluate the effects of cryopreservation on dental pulp-derived stem cells (DPSC) viability over a period of three years. Dental pulp-derived stem cells were isolated and cultured from thirty-one healthy teeth. DPSC isolates were assessed for doubling-time and baseline viability prior to cryopreservation and were assessed again at three time points; one week (T1), 18 months (T2), and 36 months (T3). DPSC can be grouped based on their observed doubling times; slow (sDT), intermediate (iDT), and rapid (rDT). Viability results demonstrated all three types of DPSC isolates (sDT, iDT and rDT) exhibit time-dependent reductions in viability following cryopreservation, with the greatest reduction observed among sDT-DPSCs and the smallest observed among the rDT-DPSC isolates. Cryopreserved DPSCs demonstrate time-dependent reductions in cellular viability. Although reductions in viability were smallest at the initial time point (T1) and greatest at the final time point (T3), these changes were markedly different among DPSC isolates with similar doubling times (DTs). Furthermore, the analysis of various DPSC biomarkers - including both intracellular and cell surface markers, revealed differential mRNA expression. More specifically, the relative high expression of Sox-2 was only found only among the rDT isolates, which was associated with the smallest reduction in viability over time. The expression of Oct4 and NANOG were also higher among rDT isolates, however, expression was comparatively lower among the sDT isolates that had the highest reduction in cellular viability over the course of this study. These data may suggest that some biomarkers, including Sox-2, Oct4 and NANOG may have some potential for use as biomarkers that may be associated with either higher or lower cellular viability over long-term storage applications although more research will be needed to confirm these findings.

• The Korean Journal of Physiology
• /
• 제20권1호
• /
• pp.125-133
• /
• 1986

Ethanol이 고양이 회장 종주근의 수축에 미치는 영향을 관찰한 결과 정상 Tyrode용액에서는 $0.5{\pm}4%$ 범위내에서 자발적 수축 및 기초장력을 억제하였으나 $Na^+$이 surcose로 대치된 용액에서는 수축을 유발시켰다. 이러한 수축은 ethanol의 농도에 비례하여 증가하였으며 용액내의 Na-free 용액으로 처리한 기간이 길수록 증가하였다. 용액내 $Ca^{2+}$이 없는 경우에도 ethanol에 의한 수축은 $La{+3}$에 의해 억제되었으나 verapamil을 전처치한 후 Na-free액을 처리했을 때는 수축이 나타나지를 않았다. Ethanol은 $^45Ca$의 유출에는 어떤 영향을 나타내지는 못하였다. 이상의 결과로 보아 Na-free용액에서 ethanol은 세포막에 결합하고 있는 $Ca^{2+}$이나 세포내부에 결합하고 있는 $Ca^{2+}$의 세포내로 유리를 증가시켜 수축을 유발시키는 것으로 사료된다.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
• /
• pp.721-727
• /
• 2002

Precipitation evapotranspiration and runoff are three key parameters of regional water balance. Problems exist in the traditional methods for calculating such factors , such as explaining of the geographic rationality of spatial interpolating methods and lacking of enough observation stations in many important area for bad natural conditions. With the development of modern spatial info-techniques, new efficient shifts arose for traditional studies. Guided by theories on energy flow and materials exchange within Soil-Atmosphere-Plant Continuant (SPAC), retrieval models of key hydrological parameters were established in the Yellow River basin using CMS-5 and FengYun-2 meteorological satellite data. Precipitation and evapotranspiration were then estimated: (1) Estimating tile amount of solar energy that is absorbed by the ground with surface reflectivity, which is measured in the visible wavelength band (VIS): (2) Assessing the partitioning of the absorbed energy between sensible and latent heat with the surface temperature, which was measured in the thermal infrared band (TIR), the latent heat representing the evapotranspiration of water; (3) Clouds are identified and cloud top levels are classified using both VIS and TIR data. Hereafter precipitation will be calculated pixel by pixel with retrieval model. Daily results are first obtained, which are then processed to decade, monthly and yearly products. Precipitation model has been has been and tested with ground truth data; meanwhile, the evapotranspiration result has been verified with Large Aperture Scintillometry (LAS) presented by Wageningen University of the Netherlands. Further studies may concentrate on the application of models, i.e., establish a hydrological model of the Yellow river basin to make the accurate estimation of river volume and even monitor the whole hydrological progress.

• 한국문헌정보학회지
• /
• 제49권3호
• /
• pp.253-272
• /
• 2015

본 연구는 동아시아 지역 성인층의 평생학습 확산을 대비한 국가간 도서관 협력의제를 고찰하기 위해 해당 지역 주요국가인 한국, 중국, 일본의 20대 청년층 정보이용자의 도서관인식과 불안을 국가간 비교연구를 통해 분석하였다. 이에 청년층 정보이용자의 상황적 맥락(선호정보원, 이용빈도, 학력, 성별)에 따른 도서관이용 의 요인별 인식차이를 조사하여 청년층 이용자의 선호정보원과 이용빈도에 따라 도서관불안에 명백한 차이가 있음을 통계적으로 입증하였다. 특히 중국의 정보이용자층이 다른 나라 이용자층에 비해 도서관이용시 각 요소에 대한 불안정도가 현저하게 높은 것으로 나타났다. 더불어 한국의 정보이용자들의 디지털정보에 관한 불안요소가 다른 나라 청년층 이용자에 비해 낮은 분포로 측정되었다. 연구결과를 기반으로 이용자들의 환경변화에 따른 정보서비스요구에 대한 도서관의 수용 및 새로운 차원의 도서관 장소 모색 등 성인층을 위한 동아시아지역 도서관운영의 개선방안 등을 제안하였다.

• 한국식품과학회지
• /
• 제30권4호
• /
• pp.948-956
• /
• 1998

전통안동식혜의 제조법을 계승 보존하고 제조 공정 및 상품성을 높여 보다 우수한 가공식품으로 개발할 목적으로 안동식혜의 발효에 관여하는 젖산균과 효모를 분리한 균주를 이용하여 안동 식혜를 제조하여 숙성 및 저장 과정 중 성분과 품질의 변화를 조사하였다. 전통안동식혜로부터 분리동정된 균주는 젖산 균주로써 L. bulgaricus LBS 47, L. acidophilus LAS 10 및 Lacto. lactis LLS 56의 3 균주와 효모 S. cerevisiae SCS 5의 한 균주를 분리하여 단독 및 혼합 균주를 start로 사용하여 숙성시킨 후 관능검사를 한 결과 LBS와 SCS 균주를 혼합배양하였을 때 가장 좋았다.

• Annals of Laboratory Medicine
• /
• 제38권6호
• /
• pp.518-523
• /
• 2018

Background: Lipemia, a significant source of analytical errors in clinical laboratory settings, should be removed prior to measuring biochemical parameters. We investigated whether lipemia in serum/plasma samples can be removed using a method that is easier and more practicable than ultracentrifugation, the current reference method. Methods: Seven hospital laboratories in Spain participated in this study. We first compared the effectiveness of ultracentrifugation ($108,200{\times}g$) and high-speed centrifugation ($10,000{\times}g$ for 15 minutes) in removing lipemia. Second, we compared high-speed centrifugation with two liquid-liquid extraction methods-LipoClear (StatSpin, Norwood, USA), and 1,1,2-trichlorotrifluoroethane (Merck, Darmstadt, Germany). We assessed 14 biochemical parameters: serum/plasma concentrations of sodium ion, potassium ion, chloride ion, glucose, total protein, albumin, creatinine, urea, alkaline phosphatase, gamma-glutamyl transferase, alanine aminotransferase, aspartate-aminotransferase, calcium, and bilirubin. We analyzed whether the differences between lipemia removal methods exceeded the limit for clinically significant interference (LCSI). Results: When ultracentrifugation and high-speed centrifugation were compared, no parameter had a difference that exceeded the LCSI. When high-speed centrifugation was compared with the two liquid-liquid extraction methods, we found differences exceeding the LCSI in protein, calcium, and aspartate aminotransferase in the comparison with 1,1,2-trichlorotrifluoroethane, and in protein, albumin, and calcium in the comparison with LipoClear. Differences in other parameters did not exceed the LCSI. Conclusions: High-speed centrifugation ($10,000{\times}g$ for 15 minutes) can be used instead of ultracentrifugation to remove lipemia in serum/plasma samples. LipoClear and 1,1,2-trichlorotrifluoroethane are unsuitable as they interfere with the measurement of certain parameters.

• 대한원격탐사학회지
• /
• 제26권2호
• /
• pp.143-151
• /
• 2010

다중시기에 획득된 SAR 영상을 이용하여 지표에서 발생하는 변위의 시계열 관측을 위한 기법에 대한 비교 분석을 수행하였다. 고정산란체를 이용한 PSInSAR 기법은 구속화된 위상을 이용하기 때문에 알고리즘의 많은 부분이 비선형 방정식을 포함하고 있어, 알고리즘 적용에 많은 주의를 필요로 한다. 특히 알고리즘 첫 단계인 고정산란체 후보의 적합한 선택 여부에 따라 알고리즘의 실행이 크게 영향을 받음을 확인하였다. 한편 짧은 기선거리를 갖는 간섭쌍을 사용하는 SBAS 기법은 입력 자료인 불구속화된 간섭도의 정확도에 따라 결과의 신뢰성이 크게 영향을 받는다. 따라서 시계열 분석에 사용되는 차분간섭도 위상의 unwrapping이 적절하게 수행될 수 있을 경우 SBAS 방법을 사용한 시계열 분석이 적절하며, unwrapping 오차가 발생할 가능성이 높은 좁은 지역에서 발생하는 국지적인 변위 관측에는 고정산란체를 이용하는 PSInSAR 기법이 적절하다. 미국 라스베가스 지역에서 1992년부터 2000년 동안 획득된 51개의 ERS-1/2 SAR 영상을 PSInSAR 기법 및 SBAS 기법에 적용하여 지표변위도를 구하였으며, 이들 간의 비교 분석을 통해 두 방법의 결과는 매우 유사하나, 다소 국지적인 지표변위는 PSInSAR 기법의 관측이 유리한 것으로 판단되었다.