• IMMUNE NETWORK
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• v.2 no.1
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• pp.41-48
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• 2002

Background: Viral antigens presented on the cell surface in association with MHC class I molecules are recognized by CD8+ T cells. MHC restricted peptides are important in eliciting cellular immune responses. As peptide antigens have a weak immunigenicity, pH-sensitive liposomes were used for peptide delivery to induce effective cytotoxic T lymphocyte (CTL) responses. In the previous study, as the HBx peptides could induce specific CTLs in vitro, we tested whether the HLA-A2/$K^b$ transgenic mice that were immunized by HBx-derived peptides could be protected from a viral challenge. Methods: HBx-peptides encapsulated by pH-sensitive liposomes were prepared. $A2K^b$ transgenic mice were immunized i.m. on days one and seven with the indicated concentrations of liposome-encapsulated peptides. Three weeks later, mice were infected with $1{\times}10^7pfu$/head of recombinant vaccinia virus (rVV)-HBx via i.p. administration. The ovaries were extracted from the mice, and the presence of rVV-HBx in the ovaries was analyzed using human TK-143B cells. IFN-${\gamma}$ secretion by these cells was directly assessed using a peptide-pulsed target cell stimulation assay with either peptide-pulsed antigen presenting cells (APCs), concanavalin A ($2{\mu}g/ml$), or a vehicle. To generate peptide-specific CTLs, splenocytes obtained from the immunized mice were stimulated with $20{\mu}g/ml$ of each peptide and restimulated with peptide-pulsed APC four times. The cytotoxic activity of the CTLs was assessed by standard $^{51}Cr$-release assay and intracellular IFN-${\gamma}$ assay. Results: Immunization of these peptides as a mixture in pH-sensitive liposomes to transgenic mice induced a good protective effect from a viral challenge by inducing the peptide-specific CD8+ T cells. Mice immunized with $50{\mu}g/head$ were much better protected against viral challenge compared to those immunized with $5{\mu}g$/head, whereas the mice immunized with empty liposomes were not protected at all. After in vitro CTL culture by peptide stimulation, however, specific cytotoxicity was much higher in the CTLs from mice immunized with $5{\mu}g/head$ than $50{\mu}g/head$ group. Increase of the number of cells that intracellular IFN-${\gamma}$ secreting cell among CD8+ T cells showed similar result. Conclusion: Mice immunized with XEPs within pH-sensitive liposome were protected against viral challenge. The protective effect depended on the amount of antigen used during immunization. XEP-3-specific CTLs could be induced by peptide stimulation in vitro from splenocytes obtained from immunized mice. The cytotoxic effect of CTLs was measured by $^{51}Cr$-release assay and the percentage of accumulated intracellular IFN-${\gamma}$ secreting cells after in vitro restimulation was measured by flow cytometric analysis. The result of $^{51}Cr$-release cytotoxicity test was well correlated with that of the flow cytometric analysis. Viral protection was effective in immunized group of $50{\mu}g/head$, while in the in vitro restimulation, it showed more spectific response in $5{\mu}g$/head group.

• Progress in Medical Physics
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• v.17 no.1
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• pp.1-5
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• 2006

A parallel plate detector containing PTFE films in FEP film for relative dosimetry was designed to measure the response of detectors to S and 10 MV X-rays from a medical linear accelerator through different thicknesses of lead. The dielectric materials were 100 m thick. The set-up conditions for measurements with this detector were as follows: SSD=100 cm the test detector was at a depth of 5 cm and the reference chamber was at a depth of 10 cm from the phantom surface for 6 and 10 MV X-rays. Lead blocks were designed to cover the irradiated field. They were added to the tray to increase thickness sequentially. We found that the detector response decreased exponentially with the thickness of lead added. The linear attenuation coefficients of the test detector and reference chamber were 0.1414 and 0.541, respectively, for 6 MV X-rays and 0.1358 and 0.5279 for 10 MV X-rays. The test detector response was greater than that of the reference chamber. The response function was calculated from the measured values of the test detector and reference chamber using optimization. These optimized constants for the detector response function were independent of theenergy. As a result of optimizing the response function between detectors, the use of a relative dosimeter was validated, because the response of the test detector was 1% for 6 MV X-rays and 4% for 10 MV X-rays.

• Korean Journal of Soil Science and Fertilizer
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• v.3 no.1
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• pp.17-21
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• 1970

To determine the effects of the silicate and the phosphate on the rice seedlings, 200 grams dry soil of the paddy field taken in the petri dish of 15cm diameter were treated with three levels of silicate(wollastonite) and phosphate. And the same amounts of nitrogen and potash were added constantly to each treated petridish. 100 grains of rice of which variety is Nongrim 25 were sown on each treated petridish simultaneously. After five times continuous culture, the rice plants and the soil were analyzed chemically and the results obtained are summarized as follows: 1. Dry matter weight of the rice seedlings was significantly increased to the increased phosphate absorption, on the other hand that was decreased when the silica absorption was increased. 2. The higher the available phosphate content in the soil after the experiments, the lower the silica content as well as absorption by the plant, and the $SiO_2/P_2O_5$ ratio in the plant was significantly decreased. 3. By the wollastonite application, the available silica, the exchangeable calcium in the soil after the experiment, and the silica content as well as silica absorption and $SiO_2/P_2O_5$ ratio in the rice plant was significantly increased. 4. Higher correlation coefficient was obtained between the exchangeable calcium amount and the silica content or silica/phosphate ratio in the rice plant than the available silica content in soil itself. 5. It is possible to control the silica/phosphate ratio in plant by the control of the silica/phosphate ratio in soil. 6. The relation between the silica/phosphate ratio in plant (y) and the available silica/phosphate ratio in soil (x) was $y=0.665+1.420x-0.0825x^2$ and the goodness of fit(r) was 82%.

• Journal of Life Science
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• v.22 no.3
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• pp.366-372
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• 2012

This study was conducted to estimate the extent of linkage disequilibrium (LD) and effective population size using whole genomic single nucleotide polymorphisms (SNP) genotyped by DNA chip in Hanwoo. Using the blood samples of 35 young bulls born from 2005 to 2008 and their progenies (N=253) in a Hanwoo nucleus population collected from Hanwoo Improvement Center, 51,582 SNPs were genotyped using Bovine SNP50 chips. A total of 40,851 SNPs were used in this study after elimination of SNPs with a missing genotyping rate of over 10 percent and monomorphic SNPs (10,730 SNPs). The total autosomal genome length, measured as the sum of the longest syntenic pairs of SNPs by chromosome, was 2,541.6 Mb (Mega base pairs). The average distances of all adjacent pairs by each BTA ranged from 0.55 to 0.74 cM. Decay of LD showed an exponential trend with physical distance. The means of LD ($r^2$) among syntenic SNP pairs were 0.136 at a range of 0-0.1 Mb in physical distance and 0.06 at a range of 0.1-0.2 Mb. When these results were used for Luo's formula, about 2,000 phenotypic records were found to be required to achieve power > 0.9 to detect 5% QTL in the population of Hanwoo. As a result of estimating effective population size by generation in Hanwoo, the estimated effective population size for the current status was 84 heads and the estimate of effective population size for 50 generations of ancestors was 1,150 heads. The average decreasing rates of effective population size by generation were 9.0% at about five generations and 17.3% at the current generation. The main cause of the rapid decrease in effective population size was considered to be the intensive use of a few prominent sires since the application of artificial insemination technology in Korea. To increase and/or sustain the effective population size, the selection of various proven bulls and mating systems that consider genetic diversity are needed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.4
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• pp.35-42
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• 1980

To establish a generation acceleration technique, two crops a year at field condition of Suweon, 10 varieties different in their spring growth habit were tested with 6 different seeding time after harvesting. These materials were harvested on June 10, 19, 79 and tested for their seed production ability at varions seeding time from July I I to August 15 with a week interval. An immatured seed germination technique and green vernalization methods were applied in cycling generations and the results obtained were summarized as follows. 1. In summer growing, seedlings establishment after transplanting was better in earlier transplanting. 2. Heading time was remarkably enhanced by earlier transplanting. Considering the results of two years early or mid of July was the suitable time to plant the second summer crop. 3. Those varieties of spring growth habit expressed little variations in plant height among the varieties. In 1978 which is referred as warm year produced plant height as tall as 8-16cm and poor crop but produced good crop with 25-65cm plant height in 1979. 4. No definit tendency in the length of spike was. observed among the cultivars but longer spike was found in winter wheat compared to the spring. 5. Number of spikes per plant was ranged from 1 to 3 regardless the transplanting time in 1979. However, more spikes per plant were produced in early or mid of July transplanting and those varieties of higher growth habit than V did not produces any spikes. 6. Higher number of grains per spike was found at earlier transplanted varieties. Therefore, it is concluded that those materials of I-IV growth habit with mid or early July transplanting would be suitable in practical sense considering their ability of seed production. 7. Two-year results indicated that wheat crop can not tolerate the temperature level higher than average 32$^{\circ}C$ C at Suweon. In this regard, the cultivation schedule was established assuming average temperature condition like the year of 1979 which was possible to grow wheats.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.73.4-74
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• 2021

한국천문연구원은 2017년 제1차 구술채록사업에 이어 2020년 제2차 사업을 진행하면서 최초로 원외 원로에 대한 구술채록을 시도하였다. 국가 대표 천문연구의 산실로서 연구원 존재 의의를 확립하기 위하여 원내 원로에 국한되었던 구술자 대상을 확장한 것이다. 그 첫 외부 구술 대상자로 방득룡 전임 노스웨스턴 천문학과 교수를 선정하여 2020년 7월부터 준비단계에 들어갔다. 방득룡 전(前)교수가 첫 번째 한국천문연구원 원외 인사 구술자로 선정된 이유는, 그가 우리나라 천문대1호 망원경 구매 선정에 개입한 서신(1972년)이 자료로 남아있었기 때문이다. 한국천문연구원에서 2017년에 수행한 제1차 구술채록사업에서 구술자로 참여한 오병렬 한국천문연구원 원로가 기증한 사료들은 대부분 연구원 태동기 국립천문대 구축과 망원경 구매 관련 자료였으며 이 가운데 1972년 당시 과학기술처 김선길 진흥국장에게 Boller and Chivesns(사(社))의 반사경을 추천한 방득룡 전(前)교수의 서신은 한국 천문학 발전사에서 중요한 사료였다. 연구진은 이 자료를 시작으로, 방득룡 전(前)교수의 생존 여부와 문서고의 공기록물들에서 그의 흔적을 찾아가기 시작했다. 놀랍게도 그는 실제 세계와 한국천문연구원 문서고 깊숙이 기록물들 모두에서 상존하고 있었다. 1927년생인 방득룡 전(前)교수, Dr. John D. R.은 미국 플로리다 한 실버타운에서 건강한 정신으로 생존하여 있었고 연구진의 인터뷰에 흔쾌히 응했다. 2020년 9월 16일에 한국천문연구원 본원 세종홀 2층 회의실에서 영상통신회의로 그와의 구술인터뷰가 진행되었다. 이 구술인터뷰는 원외 인사가 대상이란 점 외에도 방법적으로는 전형적인 대면 방식이 아닌 영상 인터뷰였다는 점에서 코로나 시대의 대안이 되는 실험적 시도였다. 현대 한국천문학 발전사의 재조명 측면에서도 의미가 있었다. 1960년대 초반부터 1992년 정년퇴임까지 30년을 미국 유수 대학교 천문학과 교수로 재직하며 활발한 활동을 해 온 한국계 천문학자가 우리나라 최초 반사망원경 구매 선정에 적극 개입하였던 역사는, 공문서 자료들과 서신 사료들에 이어 그의 육성으로 나머지 의구심의 간극이 채워졌다. 또 구술자 개인이 주관적으로 중요하다고 여기는 '기억'이 중요한 아카이빙 콘텐츠 확장의 단초가 될 수 있다는 것을 보여줌으로써 구술사 연구에 있어서도 중요한 관점을 주었다. 애초 연구진이 방득룡 전(前)교수의 공식 기록에서 아카이빙의 큰 줄기로 잡았던 것은 1948년 도미, 1957년 위스콘신 대학교 천문학 박사학위 취득, 1962년부터 노스웨스턴 대학(일리노이주 에반스턴)의 천문학 교수진, 1992년 은퇴로 이어진 생애였다. 그러나 그와의 구술 준비 서신 왕래와 구술을 통하여 알게 된 그가 인생에서 중요시 여겼던 지점은, 1948년 도미 무렵 한국의 전쟁 전 상황과 당시 비슷한 시기에 유학한 한국 천문학자들의 동태, 그리고 1957년부터 1962년까지 프린스턴 대학교에서 M. Schwarzschild 교수와 L. Spitzer 교수를 보조하며 Stratoscope Project를 연구하였던 경험이었다. 기록학적 의미에서도, 전자를 통해서 그와 함께 동시대 한국 천문학을 이끌었던 인재들의 맥락정보를 얻을 수 있었으며, 후자를 통해서는 세계 천문학사에 큰 영향을 미친 석학에 대한 아카이브 정보와의 연계 지점과 방득룡 전(前)교수의 연구 근원을 찾을 수 있었다. 이들은 추후 방득룡 콘텐츠 서비스 시에 AIP, NASM, Lyman Spitzer 콘텐츠, 평양천문대, 화천조경천문대, 서울대와 연세대, 그리고 한국천문연구원까지 연계되어 전 세계 폭넓은 이용자들의 유입을 유도할 수 있는 검색 도구가 될 수 있다. 이번 방득룡 구술사 연구에서 구술자 개인의 주관적인 소회가 공식 기록이 다가갈 수 없는 역사적 실체에 일정 부분 가까울 수 있다는 것, 그리고 이를 통하여 개인의 역사는 공동체의 역사로 확장될 수 있다는 사실을 발견할 수 있었다. 또 연구진은 방득룡 전(前)교수의 회상을 통하여 구술자 개인의 시각으로 한국과 미국 천문학계의 공동체 역사를 재조명할 수 있었고, 이것을 아카이브 콘텐츠 확장 서비스에 반영할 수 있다는 기대를 가지게 되었다. 무엇보다 이 연구를 통하여 다양한 주제의 아카이브로 연동될 수 있는 주제어와 검색도구를 구술자 개인의 회상으로부터 유효하게 도출할 수 있다는 것을 확인하였다. 그리고 향후 한국천문 구술아카이브의 확장을 통하여 보다 다양한 활용과 연구 재활용의 선순환이 가능하다는 것도 알 수 있었다. 이는 최근 기록학계에서 대두되고 있는 LOD(Linked Open Data)의 방향성과도 흡사하여 한국천문학 구술사연구의 차세대 통합형 기록관리의 미래모형을 기대케 하는 대목이다.

• Journal of Nutrition and Health
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• v.48 no.2
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• pp.180-191
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• 2015

Purpose: There is a lack of data on the energy cost of children's everyday activities, adult values are often used as surrogates. In addition, the influence of body weight on the energy cost of activity when expressed as metabolic equivalents (METs) has not been vigorously explored. Methods: In this study 20 elementary school students 9~12 years of age completed 18 various physical activities while energy expenditure was measured continuously using a portable telemetry gas exchange system ($K_4b^2$, Cosmed, Rome, Italy). Results: The average age was 10.4 years and the average height and weight was 145.1 cm and 43.6 kg, respectively. Oxygen consumption ($VO_2$), energy expenditure and METs at the time of resting of the subjects were 5.41 mL/kg/min, 1.44 kcal/kg/h, and 1.5 METs, respectively. METs values by 18 physical activities were as follows: Homework and reading books (1.6 METs), playing game with a mobile phone or video while sitting (1.6 METs), watching TV while sitting on a comfortable chair (1.7 METs), playing video game or mobile phone game while standing (1.9 METs), sweeping a room with a broom (2.7 METs) and playing a board game (2.8 METs) belong to light intensity physical activities. By contrary, speedy walking and running were 6.6 and 6.7 METs, respectively, which belong to high intensity physical activities over 6.0 METs. When the effect of body weight on physical activity energy expenditure was determined, $R^2$ values increased with 0.116 (playing a game at sitting), 0.176 (climbing up and down stairs), 0.246 (slow walking), and 0.455 (running), which showed that higher activity intensity increased explanation power of body weight on METs value. Conclusion: This study is important for direct evaluation of energy expenditure by physical activities of children, and it could be used directly for revising and complementing the existing activity classification table to fit for children.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.56-62
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• 2015

Various pretreatment methods were evaluated to prevent tissue softening of heated onion. Changes in onion tissue firmness during heating were explained by 3-mechanism model consisting of texture hardening at low temperature ($60-80^{\circ}C$) and substrate softening at high temperature. Preheating of onion in a $Ca^{2+}$-containing solution significantly improved its texture after high-temperature heating. The improvement of firmness by preheating at low temperature was related to the formation of strong cross-linking between carboxyl groups and $Ca^{2+}$ by the action of pectin methylesterase in onion. The highest firmness was obtained by pre-heating at $70^{\circ}C$ for 120 min in 0.5% calcium solution. This result was supported by chemical analysis showing that the amount of bound calcium was the highest at $70^{\circ}C$. Further investigation should be carried out to establish the optimal conditions to prevent the softening of various vegetables.

• Korean Journal of Poultry Science
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• v.36 no.1
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• pp.23-28
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• 2009

The experiment were protein and metabolizable energy level in performance and carcass rate in cross bred chicks. One day old, 720 male and female cross bred chick were used for the experiments, and 20 chicks were placed at each pen. The energy level of feed was maintained about 2,950, 3,000, 3,050 kcal/kg, and protein content was adjusted about 19, 20, 21% from 0 to 5 weeks and energy level was maintained about 3,100, 3,150, 3,200 kcal/kg, and protein content was adjusted about 17, 18, 19% from the 6 to 10 weeks old of the experiment. At the whole time, ME 3,100 (2,950), 3,150 (3,000) and 3,200 (3,050) kcal/kg treatment groups was not significant difference in weight gain, feed intake, but 3,150 (3,000), 3,200 (3,050) kcal/kg treated groups revealed to show improved feed conversion rate than the group treated with ME 3,100 (2,950) kcal (P<0.05). And CP 17 (19), 18 (20), 19 (21)% treatment groups did not significant difference weight gain and feed intake but CP 19 (21)% treated group wan significant difference feed conversion rate than the CP 17 (19)% treated group (P<0.05). ME level of 3,100 (2,950), 3,150 (3,000), 3,200 (3,050) kcal/kg treatment groups in carcass rate and abdominal fat rate was not signficant difference and protein of 17 (19), 18 (20), 19 (21)% treatment groups after end of experiment. Between ME and CP of dietary was significant appeared to interact at 6~10 weeks (P<0.05).

• Journal of Embryo Transfer
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• v.21 no.4
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• pp.281-286
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• 2006

This study was conducted to investigate the hormonal changes in cultured medium during in vitro culture of bovine oviduct epithelial cells (BOEC) supplemented with interleukin (IL)-4 of 0.001, 0.01, 0.1 or 1 ng/ml. BOEC were collected from the oviduct and washed 3 times with 1% antibiotic-mycotic-DMEM medium and cultured at $39^{\circ}C$, 5% $CO_2$, 95% air for 24$\sim$120 hrs. The cultured media were analyzed hormonal changes with hormonal analyzing kit (progesterone (P4), estradiol (E2) : Perkin Elmer, USA) and Transforming growth factor (TGF)-$\beta$ with Eliza kit (Promega, USA). The production of P4 in 0.001 IL-4 was increased as the culture time increased. P4 production was significantly higher in the medium cultured for 120 hrs than 24 hrs (P<0.05). P4 production in 0.01 ng/ml group was similar to that of 0.001 ng/ml. The production of E2 in 0.001 and 0.01 ng/ml groups were increased to 72 hrs like P4 production and showed significantly different between the culture periods (P<0.05). After the culture for 96 hrs, P4 and E2 production were increased to 96 hrs, but decreased at 120 hrs. The production of TGF-$\beta$ showed no changes according to culture period or supplementation of IL-4. In conclusion, the supplementation of IL-4 can increase the production of P4 and E2 and might have important role for the successful pregnancy in bovine.