• 제목/요약/키워드: $LS_{50}$

검색결과 151건 처리시간 0.025초

Drying Characteristics of Radishes using Far Infrared Ray Dryer

  • Park, Bum-Soon;Kang, Tae-Hwan;Lee, Jeong-Hyeon;Choi, Jong-Min;Han, Chung-Su
    • Journal of Biosystems Engineering
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    • 제40권1호
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    • pp.61-66
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    • 2015
  • Purpose: The purpose of this study was to establish conditions to dry a radish by examining the drying and quality characteristics depending on the air temperature and velocity of a far infrared conveyor dryer. Methods: A sample of weighing 6 kg was dried until the moisture content reached $15{\pm}0.5%$ (w.b.). Four temperatures (50, 60, 70, and $80^{\circ}C$) and three air velocity levels (0.4, 0.6, and 0.8 m/s) were employed as the drying factors. Results: The drying rate increased with the increase in the temperature and air velocity but decreased with time. However, the drying rate was influenced by temperature rather than velocity. At a temperature $50^{\circ}C$ with a air velocity of 0.4 m/s, it took 350 min for the radish to dry which was the longest drying time; $80^{\circ}C$ with a air velocity of 0.8m/s, it took 180 min for the radish to dry, which was the shortest drying time. ${\Delta}E$ (the color difference value) increased with the increase in temperature and air velocity. The browning and rehydration ratio increased as the temperature rose. Energy consumption decreased with the increased temperature and air velocity. Conclusions: Based on the results of this study, the best drying conditions for the radish were determined to be a temperature of $70^{\circ}C$ with an air velocity of 0.8 m/s.

Effects of Temperature and Salinity on the Survival and Metabolism of Tresus keenae (Mollusca: Bivalvia)

  • Shin Yun Kyung;Yang Moon-Ho
    • Fisheries and Aquatic Sciences
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    • 제8권3호
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    • pp.161-166
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    • 2005
  • We examined the variation in survival and the respiration and filtration rates of Tresus keenae in response to changes in water temperature and salinity. The survivorship of animals exposed to temperatures below $25^{\circ}C$ for 7 days was $80\%$; however, all test animals died on the fourth day at $28^{\circ}C$. The upper lethal temperature over 7 days was $25.9^{\circ}C$. After exposure to lower temperatures, $93\%$ ofthe animals survived at temperatures over $5^{\circ}C$ for 10 days. Survivorship rapidly decreased below $4^{\circ}C$ with all test animals dying at $2^{\circ}C$ on the eighth day. The $LT_{50}$ over 10 days was $4.8^{\circ}C$. The respiration and filtration rates of T. keenae increased as temperature increased. It is believed that energy consumption increases as a result of the increased respiration rate at temperatures above the upper lethal temperature. At temperatures below the lower lethal temperature, the metabolic rate of T. keenae was substantially lowered. In response to changes in salinity, the survivorship of T. keenae was $90\%$ at 30.2 psu after exposure for 5 days; at below 26.8 psu, all test animals died by the fifth day. The $LS_{50}$ was 29.1 psu. As salinity decreased, both the respiration rate and the filtration rate decreased. At 23.5 psu, the respiration and filtration rates decreased by 48 and $34\%$, respectively. These data have implications for increasing efficiency in the production and management of shellfish aquaculture farms.

Preculture Condition for Stable Recovery of Strawberry (Fragaria × ananassa Duch.) Shoot Tips after Cryopreservation Using Droplet Vitrification

  • Lee, Young-Yi;Lee, Sun-Yi;Song, Jae-Young;Yoon, Munsup;Yi, Jung-Yoon;Lee, Jung-Ro;Kim, Haeng-Hoon
    • 한국자원식물학회지
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    • 제33권6호
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    • pp.675-681
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    • 2020
  • This study describes an efficient and stable droplet vitrification following cryopreservation of strawberry shoot tip (Fragaria × ananassa Duch.) accessions 'Massey' and 'MDUS3816'. The shoot tips were precultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3-0.7M). Precultured explants were osmoprotected with loading solution (LS, C4) containing 17.5% glycerol and 17.5% sucrose for 40 min and exposed to dehydration solution (B1) containing 50% glycerol and 50% sucrose for 40 min at 25oC. Subsequently, the explants were transferred onto droplets containing 2.5 µL PVS3 on sterilized aluminum foils (4 cm× 0.5 cm) prior to direct immersion in liquid nitrogen (LN) for 1 h. The highest regrowth rate (%) in both the cultivars was obtained when the shoot tips were precultured with 0.3M sucrose for 30 h + 0.5M sucrose for 16 h at 25oC. The cryopreserved shoots tips exhibited 57.8 % recovery rate by culturing in NH4NO3-free MS medium supplemented with 3% sucrose, 1.0 g/L casein, 1.0mg/L GA3, and 0.5 mg/L BA for 5 weeks and in MS medium supplemented with 0.5 mg/L GA3 for 8 weeks. Variation was not observed in both of ploidy analysis and morphological investigation on plantlets of two accessions cryopreserved under variable preculture conditions.

심자도 측정용 고온초전도 SQUID magnetometer의 제작 (Fabrication of a HTS SQUID Magnetometer for Magnetocardiogram)

  • 김인선;이상길;김진목;권혁찬;이용호;박용기;박종철
    • 센서학회지
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    • 제6권4호
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    • pp.258-264
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    • 1997
  • $YBa_{2}Cu_{3}O_{7}$ 단일층 박막으로 된 직접결합형 직류 SQUID magnetometer를 설계하여 $SrTiO_{3}$기판위에 제작하였다. 검출코일은 외변 8.5 mm, 선폭은 2.6 mm로 하였으며, 조셉슨 접합의 선폭은 $3\;{\mu}m$, SQUID 인덕턴스는 50pH로 하였다. 제작된 소자의 외부 자속에 대한 전압 변조신호의 크기는 최대 $65\;{\mu}V$, 자장잡음은 1 Hz에서 약0.6 pT/$\sqrt{Hz}$ 이었다. 이 SQUID magnetometer를 사용하여 자기차폐실 내에서 심자도 파형을 측정하여 가산평균하였을 때 매우 양호한 심자도 파형을 얻을 수 있었다.

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작은방울유리화법을 이용한 딸기 생장점 초저온동결보존 (A successful regeneration from shoot tips of Fragaria x ananassa DUCH following cryopreservation by droplet-vitrification)

  • 이영이;백형진;윤문섭;코트날라 발라라주;송재영
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2019년도 춘계학술대회
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    • pp.80-80
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    • 2019
  • This study describes an efficient and widely applicable droplet-vitrification following cryopreservation for shoot tips of (Fragaria x ananassa DUCH. cvs. 'Derunoka' and 'Jumbo pure berry'. The shoot tips of strawberry were precultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3-0.7M). Precultured explants were treated with loading solution (LS, C4) containing glycerol 17.5% and sucrose 17.5% for 40 min and exposed to dehydration solution (B1) containing 50% of glycerol and 50% of sucrose for 60 min at $25^{\circ}C$, and then transferred onto droplets containing $2.5{\mu}l$ PVS3 on sterilized aluminum foils ($4cm{\times}0.5cm$) prior to direct immersion in liquid nitrogen (LN) for 1 h. The highest regeneration rate (%) was obtained when shoot tips were precultured with treatment-2 (exposing of shoot tips to MS + 0.3M Sucrose for 30 h and then treated with MS+0.5 M sucrose for 16 h) at $25^{\circ}C$ in both the cultivars. The viability of cooled samples, followed by culturing on MS medium for 4 weeks was 77.8% and 60.0% for 'Derunoka' and 'Jumbo pure berry', respectively. This result shows droplet-vitrification would be a promising method for cryobanking strawberry germplasm.

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복합조직강의 고속인장 결과를 이용한 컴퓨터 전산모사와 실제 충돌시험 결과와의 비교 연구 (A Comparative Study of Computer Simulation using High-Speed Tensile Test Results with Actual Crash Test Results of DP Steels)

  • 방형진;최일동;강성규;문만빈
    • 대한금속재료학회지
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    • 제50권12호
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    • pp.873-882
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    • 2012
  • Dual Phase (DP) steel which has a soft ferrite phase and a hard martensite phase reveals both high strength and high ductility and has received increased attention for use in automotive applications. To conduct structural analysis to verify vehicle safety, highly credible experimental results are required. In this study, tensile tests were performed in a strain rate range from $10^{-4}/s$ to 300/s for Sink Roll-Less (SRL) hot-dip metal coated sheets. Collision properties were estimated through simulation by LS-DYNA using the stress-strain curve obtained from the tensile test. The simulation results were compared with the actual crash test results to confirm the credibility of the simulation. In addition, a tensile test and a crash test with 2% prestrain and a baking (PB) specimen were evaluated identically because automotive steel is used after forming and painting. The mechanical behaviors were improved with an increasing strain rate regardless of the PB treatment. Thus, plastic deformation with an appropriate strain rate is expected to result in better formability and crash characteristics than plastic deformation with a static strain rate. The ultimate tensile strength (UTS) and absorbed energy up to 10% strain were improved even though the total elongation decreased after PB treatment, The results of the experimental crash test and computer simulation were slightly different but generally, a similar propensity was seen.

국한성병기 소세포폐암에서 하루 두 번 분할조사와 동시 화학방사선치료 (Twice Daily Radiation Therapy Plus Concurrent Chemotherapy for Limited-Stage Small Cell Lung Cancer)

  • 여승구;조문준;김선영;김기환;김준상
    • Radiation Oncology Journal
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    • 제24권2호
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    • pp.96-102
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    • 2006
  • 목적: 국한성병기 소세포폐암 환자에서 하루 두 번 분할조사에 의한 동시 화학방사선치료의 효율성을 치료 반응률, 생존율, 실패양상, 치료부작용 등의 관점에서 평가하기 위해 후향적 연구를 수행하였다. 대상 및 방법: 1993년 2월부터 2002년 10월까지 총 76명의 환자가 조직학적으로 증명된 국한성병기 소세포폐암으로 하루 두 번 분할조사에 의한 동시 화학방사선치료를 시행 받았다. 대상환자 중 남성은 84% (64/76)이었고, 중앙연령은 57세였다(32-75세). 흉부방사선치료는 120 또는 150 cGy/fraction로 최소 6시간의 간격을 두고 하루 두 번, 한 주에 5일 시행하였다. 총 흉부조사선량의 중앙값은 50.4 Gy였다(45-51 Gy). 동시 화학치료은 3주 간격으로 교대 CAV ($cytoxan\;1000mg/m^2,\;adriamycin\;40mg/m^2,\;vincristine\;1mg/m^2$)/PE ($cisplatin\;60mg/m^2,\;etoposide\;100mg/m^2$)이거나, 혹은 단독 PE 요법이 사용되었다. 화학치료 횟수의 중앙값은 6회였다(1-9회). 예방적 전뇌조사는 완전관해를 보인 환자에게 25 Gy/10 fractions로 시행되었다. 중앙추적관찰기간은 18개월이었다(1-136개월). 결과: 치료의 반응률은 86%이었다: 완전관해가 39명(52%), 부분관해가 26명(34%)이었다. 중앙생존기간은 23개월이었다. 1년, 2년, 3년 생존율은 각각 72%, 50%, 30%이었다. 단변량분석에서 치료 반응률이 생존율의 유의한 예후인자로 밝혀졌다(p<0.001). 등급 3 이상의 급성부작용은 백혈구감소 46명(61%), 적혈구 감소 5명 (6%), 혈소판 감소 10명(13%), 식도염 5명(6%), 그리고 폐독성이 2명(2%)에서 있었다. 추척관찰이 가능했던 73명의 환자 중 총 38명(52%)에서 병의 진행이 관찰되었다. 첫 번째 원격전이 장소의 빈도는 뇌가 가장 높았다. 결론: 하루 두 번 분할조사에 의한 동시 화학방사선치료는 국한성병기 소세포폐암 환자에서 나쁘지 않은 부작용과 함께 양호한 치료반응 및 생존율의 결과를 보였다. 생존율의 유의한 예후인자로 밝혀진 치료 반응률을 향상시키기 위해 방사선치료 분할방식, 화학요법제제, 화학방사선치료의 결합방식에 대한 추가적인 연구가 필요할 것으로 생각된다.

비파엽 추출물의 항산화 효능과 성분분석 (Antioxidative Effect and Component Analysis of Eriobotrya japonica Leaf Extracts)

  • 김수지;박진오;박수남
    • 대한화장품학회지
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    • 제38권1호
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    • pp.57-65
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    • 2012
  • 본 연구에서는 비파엽 추출물의 항산화 활성, 타이로시네이즈 저해 활성, 및 추출물/분획의 성분 분석에 대한 연구를 수행하였다. 비파엽 추출물의 자유라디칼(1,1-diphenyl-2-picrylhydrazyl, DPPH) 소거활성($FSC_{50}$)은 50 % 에탄올 추출물($22.63{\mu}g/mL$) < 에틸아세테이트(ethyl acetate) 분획(6.75) < 당을 제거시킨 아글리콘(aglycone) 분획(5.06) 순으로 증가하였다. 루미놀(luminol)-의존성 화학발광법을 이용한 $Fe^{3+}-EDTA/H_2O_2$ 계에서 생성된 활성산소종(reactive oxygen species, ROS)에 대한 총항산화능은 에틸아세테이트 분획($OSC_{50}$, $0.75{\mu}g/mL$), 아글리콘 분획(0.79) 및 50 % 에탄올 추출물(1.61)에서 모두 큰 활성을 나타내었다. 비파엽 추출물의 rose-bengal로 증감된 사람 적혈구의 광용혈에 대한 보호효과를 조사하였다. 비파엽 추출물은 모든 분획에서 농도 의존적($5{\sim}50{\mu}g/mL$)으로 증가하였으며, 특히 에틸아세테이트 분획은 $10{\mu}g/mL$ 농도에서 ${\tau}50$이 390.8 min, $50{\mu}g/mL$ 농도에서 ${\tau}50$이 1471.5 min으로 높은 세포 보호 활성을 나타내었다. 타이로시네이즈 저해 활성($IC_50$)은 에틸아세테이트 분획($75.25{\mu}g/mL$) < 50 % 에탄올 추출물($74.1{\mu}g/mL$) < 아글리콘 분획($43.35{\mu}g/mL$) 순으로 미백제로 알려진 알부틴보타 타이로시네이즈 저해활성이 크게 나타났다. 비파엽 추출물 중 에틸아세테이트 분획의 TLC 분석 결과 7개의 띠(EJL 1 - EJL 7)가 나타났다. HPLC로 아글리콘 분획을 분석한 결과 kaempferol 및 quercetin이 각각 53.7 % 및 46.3 %였으며, 따라서 추출물 중에는 kaempferol 및 그 배당체 비율이 다소 높은 것으로 나타났다. 이상의 결과들은 비파엽 추출물 또는 분획이 $^1O_2$ 및 다른 ROS를 소거 또는 소광함으로써 그리고 ROS에 대항해서 세포막을 효과적으로 보호함으로써 태양 자외선에 노출된 피부를 보호하는 항산화제로서 작용할 수 있음을 가리키며, 타이로시네이즈 저해 효과로부터 비파엽 추출물 및 분획물은 기능성 화장품 원료로서 응용가능성이 있음을 시사한다.

한국인에서의 상악골 교정수술후 안면중부 연조직 변화에 관한 연구 (MID-FACIAL SOFT TISSUE CHANGES FOLLOWING ORTHOGNATHIC SURGERY OF THE MAXILLA IN KOREANS)

  • 박형식;최진호;김영수
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제13권3호
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    • pp.278-290
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    • 1991
  • Prediction of the sop tissue changes following hard tissue movements is very important in the preoperative analysis of surgical changes of the patient who have orthognathic surgery. This study examined post operative changes of the mid-facial sop tissues in Koreans depending upon two major positional changes of the maxilla following Le Fort - I type osteotomy for orthognathic purposes. Sixty patients(41 males and 19 females) of Koreans were selected and divided into two groups according to directional change of movement of anterior bony structures of the Maxilla as follows : Group I (44 patients) was mooed anteriorly and/or inferiorly, and Group II (16 patients) was mooed posteriorly and/or superioly. Postoperative changes of the sop tissue measurements following hard tissue changes were examined on pre - and post - operative cephalometrics by means of computerized digitation methods and the ratios of changes were analysed. The results were obtained as follows : 1. In Group I, all of the sop tissue measures except the Pn was closely followed by the changes of the hard tissue measures in the horizontal plane, but the Sn and the Cm were only correlated to the vertical changes(p<0.001). In group II, all of the sop tissue measures excluding of the N' and the Pn were significantly correlated to the hard tissue measures in horizontal plane(p<0.001), but the Ls and Stm were only correlated relatively to the vertical changes of the ANS(p<0.01). 2. Predictable ratio of the Sn was 66% of the ANS or 56% of the A in the horizontal plane and 89% of the A in the vertical plane in Group I. In Group II, the Sn was predictable as 85% of the ANS or 70% of the A in the horizontal plane but was not predictable in vertical plane. 3. Predictable ratio of the Cm was 28% of the ANS or 50% of the A in the horizontal plane and 56% of the ANS or 36% of the A in the vertical plane in Group I. In Group II, the Cm was predictable horizontally as 74% of the A. Predictable ratio of the Pn was 30% of the ANS or 38% of the A in horizontal plane in Group I, but it was not predictable both horizontally and vertically in Group II. 4. Predictable ratio of the Ls was 52% of the Pr in Group I and 77% in Group II in the horizontal plane. The Stm was predictable as 34% of the pr or 22% of the I in the horizontal plane in Group I, and was also predictable as 55% of the pr or 68% of the I horizontally and 21% of the pr or 65% of the I vertically in Group II. 5. All ratios of change in the thickness. length and area of the upper lip following maxillary movement were statiscally correlated, however, mangitudes of them were meaningful clinically.

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유산균에 의한 양파 착즙액의 발효효과와 이화학적 특성 (Fermentation of onion extract by lactic acid bacteria enhances its physicochemical properties)

  • 김수환;이채미;정재희;최유리;이동훈;이채윤;허창기
    • 한국식품과학회지
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    • 제54권4호
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    • pp.445-454
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    • 2022
  • 본 연구는 우수한 생리활성을 나타내는 것으로 알려진 양파 껍질을 식품으로 활용하고 유산균 발효를 통해 기능성 증진을 도모하고자 과육과 함께 양파 껍질을 착즙하고, 착즙액 발효에 적합한 유산균을 선정하고자 발효에 따른 품질특성 및 항산화 활성을 검토하였다. 양파 착즙액의 유산균 발효에 따라 pH와 당도는 감소하였으며, 적정 산도는 증가하였고 유산균 수는 발효 48시간까지 증가한 후 감소하였다. 총 유리당 함량은 모든 발효물에서 감소하였으며, 유리당 조성 변화의 경우 Bb와 Lb 접종 양파 착즙액 발효물에서는 fructose, glucose 및 sucrose가 감소하였으며, 이외의 균주 접종 양파 착즙액 발효물에서는 fructose와 sucrose는 감소한 반면, glucose는 증가하였다. 총 유기산 함량은 발효에 의해 증가하였으며, 유기산 중 lactic acid가 가장 많이 증가하였다. 발효에 따른 quercetin 함량은 Ll, Ls 및 Pp 접종 양파 착즙액 발효물은 감소한 반면, Bb, Ef, Lb 및 St 접종 양파 착즙액 발효물은 증가하였다. 총 폴리페놀 함량은 Bb, Ll, Lb 및 Ls 접종 양파 착즙액 발효물은 증가하였으나, Ef, St 및 Pp 접종 양파 착즙액 발효물은 감소하였고, 총 플라보노이드 함량은 St 접종 양파 착즙액 발효물을 제외한 모든 발효물에서 증가하였다. DPPH 및 ABTS 라디칼 소거능은 유산균 발효에 의해 증가하였다. 본 연구 결과 양파 착즙액의 유산균 발효는 생리활성과 기능성을 증진 시키는 것으로 나타났으며, 특히 B. breve KCTC 3441 균주 발효를 통해 quercetin, polyphenol, flavonoids 함량이 각각 50%, 57%, 39% 그리고 DPPH와 ABTS 라디칼 소거능은 74%와 29% 증가되었다. 따라서 양파착즙액의 발효 균주는 B. breve KCTC 3441이 적합한 것으로 판단된다.