• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.27 no.2
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• pp.97-104
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• 1991

Generally, the coefficients of common holding power of an anchor and a chain cable have been reported too higher in their values in the safety of the shiphandling. The model experiment was carried out to find the most suitable coefficients of holding power of the Hall's type anchor and the chain cable in various kinds of seabed. The results obtained are summarized as follows; 1) The coefficients of holding power of the anchor and the chain cable were 4.05, 0.75 in the mud, 3.95, 0.66 in the sand and 3.61, 0.72 in the pebbles respectively. 2) The experimental coefficients of holding power of the anchor and the chain cable were 0.4~0.6 times the values of the coefficients of common holding power. They were almost same as the values of the coefficients of safe holding power in the mud and the sand, but in case of the pebbles, they were 1.4~1.8 times the values of the coefficients of safe holding power. 3) It is considered useful for the safety of the shiphandling to draw curves of the holding power with maximum limits holding power at the various wind forces and the coefficients of holding power.

• Korean Chemical Engineering Research
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• v.60 no.4
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• pp.544-549
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• 2022

This study presents the negative pressure cavitation acetone-pentane fractional precipitation to dramatically improve the precipitation efficiency of paclitaxel from Taxus chinensis. When paclitaxel was precipitated under a negative pressure of -200 mmHg, most paclitaxel (>99.9%) could be recovered in a short precipitation time (5 min). The precipitation rate constant increased by 1.512~5.073 times (at -50 mmHg to -200 mmHg) compared to the control. The activation energy decreased by -3,737~-6,536 J/mol due to negative pressure, which increased the precipitation rate. With the introduction of negative pressure, the precipitate size decreased by 5.3 times, and the diffusion coefficient of paclitaxel increased by 7.0 times.

• The Korean Journal of Mycology
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• v.44 no.4
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• pp.330-337
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• 2016

Streptomyces sp. A75 and A501 inhibited the mycelial growth of pathogenic Rhizoctonia solani and Pythium sp., which cause the ginseng disease known as damping-off. Three methods were evaluated for the control of these pathogens, using a mixture of the culture broths from Streptomyces sp. A75 and A501. The methods tested were seed dipping with 50-fold diluted broth, drenching of soil with 100-fold diluted broth after sowing, and combined seed dipping and drenching. These methods reduced the incidence of ginseng damping-off caused by R. solani by 81.3%, 84.8%, and 32.2% and that caused by Pythium sp. by 51.0%, 52.1%, and 75.3%, respectively. Based on these results, the combination of seed dipping and soil drenching after sowing using a mixture of the culture broths from Streptomyces sp. A75 and A501 effectively reduced the incidence of damping-off in ginseng.

• Food Industry And Nutrition
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• v.12 no.2
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• pp.51-57
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• 2007

한국산 복령과 후박의 이용성 확대를 위하여 각각 추출물의 ABTS와 DPPH라디칼의 소거능, 환원력의 항산화능 효과 및 인체암 세포주의 항암활성에 대하여 조사하였다. 복령과 후박을 버섯균사체로 발효시킨 한약 추출액의 항산화활성(ABTS와 DPPH 라디칼소거, 환원력)은 시료 추출물의 농도가 증가할수록 비례적으로 증가하였으며, DPPH 라디칼 소거활성은 ABTS보다 비교적 높게 나타났고, 원료후박 추출물($21.16{\sim}24.68%$)은 원료복령 추출물($45.46{\sim}49.63%$)에 비하여 약 2배 이상 높았다. 복령 시료 추출물의 농도별에 따른 환원력은 원료 복령($0.55{\sim}0.63$)에 비하여 동충하초, 팽이버섯 및 큰 느타리 균사체로 발효시킨 시료($0.50{\sim}0.62$)의 흡광도로 서로 비슷한 증가를 나타내었고, 후박 시료 추출물의 농도별에 따른 환원력은 원료 후박 추출물($0.98{\sim}1.06$)이 3가지의 버섯 균사체 발효후박 추출물($0.76{\sim}1.01$)에 비하여 약간 높았다. 자궁경부암세포(HeLa)와 대장암세포(HT-29)는 원료복령과 후박의 추출물이 각각의 발효한약에 비하여 저해활성이 높았다. 간암세포(HepG2)는 $200{\mu}g/assay$ 농도에서 팽이버섯 균사체 발효복령의 추출물이 가장 높았는데, 원료복령과 동충하초 및 큰 느타리에 비하여 각각 1.79, 1.35, 1.03배 높은 저해활성을 나타내었다. 그리고 팽이버섯과 동충하초 균사체를 배양한 발효후박에서 각각 $11.39{\sim}53.92%$, $10.71{\sim}50.21%$ 범위였으며, 원료후박에 비하여 $200{\mu}g/assay$ 농도에서 각각 2.21배, 2.05배 높은 저해활성을 나타내었다. 유방암세포(MCF-7)는 발효복령 추출물의 저해활성이 팽이버섯 균사체($58.35{\sim}72.87%$)에서 가장 높았으며, 큰 느타리버섯($61.04{\sim}67.66%$)과 동충하초($39.74{\sim}66.40%$) 및 원료복령($50.32{\sim}69.24%$)은 서로 비슷하였다.

• Korean Journal of Poultry Science
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• v.16 no.2
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• pp.61-71
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• 1989

The purposes of this study were to investigate the genetic variations by backcrossing in commercial chickens. Backcrossing was carried out successively back to parent stock (P.S). Heritabilities and genetic correlation coefficients were estimated to verify the genetic variations. The data obtained from a breeding programme with commercial chickens (I strain) were collected from 1955 to 1987 at Poultry Breeding Farm, Seoul National University. Data came from a total of 1230 female offspring. The results obtained are summarized as follows： 1. The general performance ($Mean\pmStandard deviation$) of each trait was $663.94\pm87.11$g for 8 weeks body weight, $1579.1\pm155.43$g for 20 weeks body weight, $2124.1\pm215.3$g for 40 weeks body weight, $2269.1\pm242.94$g for 60 weeks body weight, $168.43\pm12.94$ day for a9e at sexual maturity (SM), $214.52\pm29.82$ eggs , for total egg number to 60 weeks of age (TEN), $61.45\pm3.48$ g for average weight (AEW), $13180.7\pm1823.22$ g for total egg mass to 60 weeks of age(TEM). All traits, except 10 weeks body weight and AEW, were significant for the degrees of backcross (p＜0.01). 2. The pooled estimates of heritabilities derived from the sire, dam and combined variance components were 0.47~0.52 for age at sexual maturity (SM), 0.07~0.37 for total egg number (TEN), 0.40~0.54 for average egg weight (AEW), 0.18~0.27 for total egg mass (TEM). High heritability estimates were found for SM and AEW. TEN and TEM were estimated to be a lowly heritable traits. Heritability estimates from dam components were higher than those from sire components. These differences might be due to non-additive genetic effect and maternal effect. 3. The estimates of heritabilities and standard errors derived from combined variance components for different degrees of backcross were $0.47\pm0.11$ (BCO), $0.42\pm0.16$ (BC1), $0.51\pm0.29$ (BC2) for TEN, $0.59\pm0.20$ (BCO), $0.43\pm0.17$ (BC1), $0.35\pm0.18$ (BC2) for AEW, $0.28\pm0.12$(BC0), $0.20\pm0.11$(BC1), $0.18\pm0.14$ (BC2) for TEM. Heritability estimates for AEW and TEM were decreased by backcrossing while those for SM and TEN remained constant. Since backcrossing contributes to increased homozygosity, the genetic variation of the traits (AEW and TEM) decreased . 4. The pooled estimates of genetic correlation coefficients were -0.55 between SM and TEN, 0.20 between SM and AEW, -0.29 between TEN and AEW, 0.82 between TEM and TEN, 0.31 between TEM and AEW, -0.42 between TEM and SM. The genetic correlation between TEM and TEN was higher than that between TEM and AEW, and it was suggested that egg mass was strongly affected by egg number. Also, age at sexual maturity(SM) contributes to egg mass(TEM). 5. When backcrossing was carried out successively, the genetic correlation between TEM and TEN increased (BC0：0.79, BC1：0.82, BC2：0.91) but those between TEM and SM decreased (BC0：-0.54, BC1：-0.36, BC2：-0.09) with successive backcrosses.

• Journal of Embryo Transfer
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• v.8 no.1
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• pp.13-19
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• 1993

These experiments were carried out to determine the effect of pregnancy in bisected embryo. The embryos of ICR mouse were microsurgically bisected at morula and blastocyst stage using microsurgical blade attached a micromanipulator. These bisected embryos without zona pellucida were cultured up to blastocyst stage and cell count and diameter of stained blastomere, and transferred pseudopregnant mice. And the development of these bisected embryos was compared with the results of production of young of the corresponding intact embryos or cell stage. When the bisected mouse embryos were cultured in vitro for 20 to 24 hours in morula stage(77.2%) or 3 to 6 hours in blastocyst stage(84.1%), them were developed to the expanded blastocyst stage. There were no significant(P<0.05) differences in the development rate of bisected embryos between in morula and blastocyst stages. The embryo size of blastocyst developed in vitro from bisected embryo was small(P<0.05)than intact embryo. However, the number of blastomeres with bisected embryo (24.7+1.3and 21.5+1.2 respectively) were significantly(P<0.05) reduced, compared with that of intacted embryos(36.3+1.1 and 41.4+1.2 respectively). When compared with the result of pregnancy rate(63.6%) after surgical transfer of bisected morulae, a similar result(65.4%) was obtained with bisected blastocyst stage(P< 0.05). However, production of youngs (38.8%) after transfer of bisected morula, a similar result (38.1%) was obtained with bisected blastocyst stage (P<0.05).

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2003.11a
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• pp.79-80
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• 2003

국내의 대부분 도시하천에 우점하여 나타나는 깔따구속(Chironomus)은 국내에 밝혀진 깔따구과(Chironomidae)중에서 가장 다양한 종다양성을 보이며 개체가 상대적으로 크고 사육이 용이하여 생태학, 독성학 및 분자유전학적 재료로 널리 쓰이고 있다. 그러나 깔따구속 각 종간의 성충 및 유충의 형태적 유사성으로 인하여 많은 분류학적 어려움을 안고 있다. 특히 국내에 분포하는 노랑털깔따구(C. flaviplumus)와 요시마쓰 깔따구(C. yoshimatsui)는 성충과 유충에 있어서 많은 변이가 나타나 여러 문헌에서 혼동되어 쓰이고 있는 실정이므로 그들의 분류가 시급한 실정이다. 본 연구에서는 전형적인 한국의 도시하천인 서울시 중랑천을 대상으로 그곳에 우점하는 장수깔따구(C. plumosus), 구슬등무늬깔따구(C. circumdatus), 등깔따구(C. dorsalis), 안개무늬깔따구(C. kiiensis), 요시마쯔깔따구의 형태적 유사성 및 차이점을 비교하였다. 채집된 요시마쯔깔따구는 배무늬 및 생식기 형태에서 다양한 변이를 보였으며, Wing length 2.77$\pm$0.17mm (2.53-2.94), Leg ratio(L.R.)가 1.60$\pm$0.05, Antenna ratio(A.R.) 2.84土0.10의 값을 나타냈다. 일부 개체는 A.R.이 3.35로 국내산 노랑털깔따구(A.R. 3.50$\pm$0.11, Ree & Kim, 1981)와 혼란될 수 있으나 이는 요시마쯔깔따구 군집내의 변이로 생각된다. 국내에 기록된 요시마쯔깔따구와 노랑털깔따구는 일본산 요시마쯔깔따구와 노랑털깔 따구가 A.R.값이 각각 3.1과 4.0(Sasa, 1978)으로 구별되는 것과 달리 A.R.에서 큰 차이가 나타나지 않고 배무늬 및 생식기 형태의 변이 폭이 크게 나타나므로 앞으로 전국적인 지역에 분포하는 상기 두 종의 개체군에 대한 비교 연구가 필요하다.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.233-237
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• 2006

In the present study, we compared the functional analysis of pear extracts cultured in conventional and environment-friendly conditions in primary cultured rat hepatocytes. ATP synthesis significantly increased by the treatment with environment friendly cultured pear powder but not by conventional group. In addition, cell proliferation using $[^3H]$-thymidine incorporation was also stimulated by environment-friendly cultured pear extract compared to conventional group. Moreover, the expressions of CDK-2 and CDK-4 were increased but p21WAF1/Cip1 and p27 Kip1 decreased by environment-friendly cultured pear extract but not by conventional group. In conclusion, environment-friendly cultured pear powder has stimulatory effect on cell proliferation compared to conventional group in primary cultured rat hepatocytes.

• 전기의세계
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• v.13 no.1
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• pp.1-5
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• 1964

철심형 동기발전기를 무부하로 운전하는 중 1상중성점간에 단락사고가 돌발한 경우에 그 단락상의 전기자전류와 계자전류를 표시하는 식을 구하여 본다. 식(12)의 단락전류 $i_{L-N}$을 단수형으로 전개해서 기수배조파와 우수배조파로 분리해서 검토를 하고 계자전류 I는 곧 I=E+2/3( $x_{d}$-x'$_{x}$) $i_{L-N}$cos .theta.의 관계식에서 일단 단락전류 $i_{L-N}$가 구해졌으므로 단지 대입하므로써 간단히 얻어진다. 식(12)와 (17)을 도시하는데 필요한 동기기정수를 $x_{d}$=0.78, $x_{q}$ =0.48, x'$_{d}$=0.21, r=0.03, $T_{0}$=163 및 E=1의 perunit치로 가정한다.it치로 가정한다.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.222-227
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• 2005

To evaluate the antimutagenic activity of the specialty rices, a giant embryonic rice and a pigmented rice, we measured the inhibitory effect on the chemically induced mutagenesis in E. coli and V79 cultured cell system, as well as on DNA strand scission induced by oxidative damages in vitro. When the inhibitory activity to mitomycin C-induced mutagenesis using SOS chromotest in E. coli cell was measured, the activities decreased in the following order: germinated pigmented rice (40.4%) > germinated giant embryonic rice (37.1%) > pigmented rice (35.5%) > germinated brown rice (15.7%) > giant embryonic rice (14.0%) > brown rice (0.8%). The activities for inhibiting mitomycin C-induced DNA strand scission decreased in the order of pigmented rice > giant embryonic rice > germinated pigmented rice > germinated brown rice > brown rice > germinated giant embryonic rice. We also determined antimutagenic activities of the specialty rices using the suppressing effect on 6-TG resistant colony formation by 4-NQO in V79 cells as a mutagenicity index. The order of antimutagenicity was germinated giant embryonic rice (53.2%) > pigmented rice (40.0%) > brown rice (21.2%) > germinated brown rice (14.4%) > giant embryonic rice (0.23%); in contrast, germinated pigmented rice showed promoting effect on 4-NQO-induced mutagenesis.