• Journal of fish pathology
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• v.35 no.1
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• pp.113-120
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• 2022

Scuticociliatosis caused by Miamiensis avidus is a very important parasitic disease in olive flounder farming industry. The aim of this study was to determine effect of combined treatment with blue LED (light-emitting diode) illumination and formalin on olive flounder (Paralichthys olivaceus) infected with M. avidus. Different intensity of 405 nm LED (20, 40, and 60 μmol·m^-2·s^-1) was illuminated on 2.2×10⁴ cells/well of M. avidus in a 24 well microplate for 24 h. Also, 2.4×10⁴ cells/well of M. avidus were exposed to varying combinations of 60 μmol·m^-2·s^-1 of 405 nm LED and serial 10-fold dilutions of formalin (from 10 to 100 ppm) for 15, 30, 45, and 60 min. Surviving M. avidus were counted using a hemocytometer. For in vivo test, flounder acclimatized at 11-12 practical salinity unit (psu) were challenged with 2×10⁶ cells/ml of M. avidus by immersion method for 1 h. Then, fish were moved and divided into four groups; "F" group, treated with formalin at 50 ppm; "L" group, treated with 60 μmol·m^-2·s^-1 of 405 nm LED; "C" group, treated with combination of the two methods; and the control group. After treatment for 30 min, fish were transferred to new tanks (salinity = 11-12 psu) and observed for 3 weeks. As a result, illumination of 405 nm LED at 60 μmol·m^-2·s^-1 killed 100% of M. avidus after 12 h, while 67% and 90% of the scuticociliate died at 20 and 40 μmol·m^-2·s^-1, respectively, after 24 h exposure. One hundred percent of M. avidus was killed at 90, 80, 80 and 70 ppm after exposure to formalin for 15, 30, 45 and 60 min, respectively. However, combined method (e.g., 60 μmol·m^-2·s^-1 of 405 nm-LED plus 50 ppm formalin) killed the parasite within 30 min. From in vivo test, similarly, survival rates of fish challenged with M. avidus were 100%, 43%, 29% and 0% in the C, F, L, and control groups, respectively. Results obtained in this study demonstrates that the combined treatment method has clear synergistic effect on scuticociliatosis in fish.

• Journal of Ginseng Research
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• v.32 no.3
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• pp.226-231
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• 2008

Ginsenosides have been regarded as the principal components responsible for the pharmacological and biological activities of ginseng. Absorption of major ginsenosides from the gastrointestinal tract is extremely low, when ginseng is orally administered. In order to improve absorption and its bioavailability, conversion of major ginsenosides into more active minor ginsenoside is very much required. Here, we isolated lactic acid bacterium (Lactobacillus brevis LH8) having ${\beta}-glucosidase$ activity from Kimchi. Bioconversion ginsenoside Rd by this bacterium in different temperatures was investigated. The maximum activities of crude enzymes precipitated by ethanol were shown in $30^{\circ}C$ and then gradually decreased. In order to compare the effect of pH, the crude enzymes of L. brevis LH8 were mixed in 20mM sodium phosphate buffer (pH 3.5 to pH 8.0) and reacted ginsenoside Rd. Ginsenoside Rd was almost hydrolyzed between pH 6.0 and pH 12.0, but not hydrolyzed under pH 5.0 and above pH 13.0. Ginsenoside Rd was hydrolyzed after 48 h incubation, whereas ginsenoside F2 appeared from 48 h to 72 h, and ginsenoside Rd was almost converted into compound K after 72 h.

• Clinical and Experimental Reproductive Medicine
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• v.12 no.2
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• pp.25-37
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• 1985

Four points on the basal body temperature (B.B.T.) curve was correlated with the estimated time of ovulation, as determined by serial ultrasound in 50 induced menstrual cycles from 22 subjects. The time of ovulation was estimated by measuring the maximal diameter of follicles and observing the morphologic changes within the ovary from follicle to corpus luteum. The results were as following; 1. The diameter of the follicle measured at the day before disappearance was 21.1 mm on an average (S.D.: 2.14). The average follicular growth for 4 days before ovulation was measured at a rate of 2.8 mm/day, and rapid growth of follicle was observed 3.1 mm/day at the day before. 2. The changes associated with rupture of the follicles were the followings, in order of frequency; decrease in size(94%), disappearance of follicles(64%), fluid in the Cul-de-Sac(26%) and increased internal echoes(16%). 3. Only 20 of 50 cycles, exhibited a BBT dip and correlated with the estimated time of ovulation by ultrasound in 2 of which cases(10%). BBT nadir, 30 of 50 cycles, correlated in 5(16.7%). The first day of hyperthermic plateau(FDHP) and BBT coverline was exhibited in all cycles, correlated in 41(82%) and 35(70%) cases. 4. The relationship between the diameter of dominant dominant follicle, measured by ultrasound, and the basal body temperature curve were as following. During cycles in which dip was observed on the BBT curve, the follicular diameter were 10.5${\pm}$2.12 mm on 4 days prior to the point (D-4), and 12.5${\pm}$2.12 mm (D-3), 15.5${\pm$2.12 mm (D-2), 17.0${\pm}$1.41 mm (D-1) and 21.5${\pm}$2.12 mm just prior to the dip (D-0). In the nadir; 9.6${\pm}$1.67 mm (N-4), 12.8${\pm}$1.79 mm (N-3), 16.2${\pm}$1.92 mm (N-2), 18.2${\pm}$2.17 mm (N-1) and 21.4${\pm}$2.61 mm (N-0). In the First day of Hyperthemic Plateau (FDHP); 9.8${\pm}$1.36 mm (F-4), 12.4${\pm}$1.41 mm (F-3),15.1${\pm}$1.57 mm (F-2), 18.1${\pm}$1.67 mm (F-1) and 21.2${\pm}$2.25 mm (F-0). In the BBT coverline endopint; 9.9${\pm}$.39 mm (C-4), 12.5 ${\pm}$1.44 mm (C-3), 15.2${\pm}$1.64 mm (C-2), 18.0 ${\pm}$1.69 mm (C-1), and 21.2${\pm}$2.31 mm (C-0). 5. The relationship between the ultrasonographic signs of ovulation and the basal body temperature curve were as following. The BBT dip correlated with the ovulation in 2 cases, which revealed decrease in follicular diameter (100%), fluid pattem in the Cul-de-Sac (1 case, 50%) and complete disappearance of follicle (1 case, 50%). In the nadir (5 cases); the ultrasonographic signs of ovulation were decrease in follicular diameter (5 cases, 100%), fluid pattern in the Cul-de-Sac (1 case, 20%) and complete disappearance of follicle (3 cases, 60%). In the First day of Hyperthermic Plateau (41 cases); decrease in follicular diameter (40 cases, 97.6%), fluid pattern in the Cul-de-Sac (11 cases, 26.8%), appearance of internal echo and thickening of the wall (6 cases, 14.6%) and com plete disappearance of follicle (28 cases, 68.3%). In the BBT coverline endpoint (35 cases); decrease in follicular diameter (33 cases, 94.3%), fluid pattern in the Cul-de Sac (9 cases, 25.7%), appearance of internal echo and thickening of the wall (5 cases 14.3%) and complete disappearance of follicle (20 cases, 57.1%).

• Journal of Soil and Groundwater Environment
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• v.8 no.4
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• pp.68-73
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• 2003

This study performed from 2002 October to 2003 April. The samples were taken at 66 sites, divided into the 6 sections functionally in the southern part of Seoul such as Yangchon-gu, Kangseo-gu, Kuro-gu, Yeongdengpo-gu, Kwanak-gu, Dongjak-gu, Seocho-gu, Kangnam-gu, Songpa-gu, and Kangdong-gu. The result of research showed that each property soil was pH 4.7∼9.5, Cd; 0.391 mg/kg (0.011∼l.081 mg/kg). Cu; 12.35 mg/kg (0.061∼73.62 mg/kg), Pb; 13.04 mg/kg (N.D.∼61.85 mg/kg), Hg; 0.0866 mg/kg (N.D.∼1.353 mg/kg), F; 206.8 mg/kg(47.1∼561.1mg/kg). The minimum and maximum of the concentration with functional soils were Cd; 0.632 mg/kg for multi-purposed soil,0.079 mg/kg for schools, Cu; 21.35 mg/kg for roadside, 2.159 mg/kg for schools, Pb; 24.70 mg/kg for roadside, 1.030 mg/kg for schools, Hg; 0.1780 mg/kg for multi purposed, 0.0087 mg/kg for schools. Especially F was the high concentration at the hills. Also the concentration of Cd, Cu, Pb, Hg and F at school Zone was detected such as low. area of schools area was detected the low concentrations as the items of Cd, Cu, Pb, Hg, and F. The average concentrations of metals and fluorine in the survey area were below the Preliminary Standard of the Soil Preservation Acts in Korea. To evaluate the soil quality of these area showed as a good qualified results. The results of SQPI (Soil Quality Pollution Index the qualified results as much as 86.4%.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.3
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• pp.167-173
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• 1998

In order to estimate the life time of epoxy composites used for modeling material of transformer, the AC breakdown experiments of it were experimented and then the AC breakdown data were also simulated by Weibull distribution equation in this study. The life time of H100F65 specimen was the shortest and it of SH100F65 specimen was the longest, and as the AC voltage was applied to specimen for 50[min], the breakdown probability of each specimen was 31.2[%], 17.00[%], 84.36[%] and 12.35[%], respectively.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.34-34
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• 2003

Piezoelectric or magnetostrictive materials, known as smart materials, have been researched widely for sensors or actuators in micro system technology. In our research, thick sol-gel lead zirconate titanate(Pb(Zr$\sub$1-x/Ti$\sub$x/)O$_3$) films were fabricated and their characteristics were investigated f3r angular rate sensor applications. The thickness of the PZT films is 1.5${\mu}$m, which is required by a vibration angular rate sensor for a good actuation and sensing. The remnant polarization of the PZT flms is 12.0 ${\mu}$C/$\textrm{cm}^2$. The electromechanical constants of PZT thin film showed the value of susceptance(B) of 4800${\mu}$ s at capacitance of 790pF. The PZT films were applied to the vibration angular rate sensor structure and the vibration of 1.78 ${\mu}$m in amplitude at the resonant frequency of 35.8㎑ was obtained by driving voltage of 5V$\sub$p-p/ of bulk piezoelectric materials with out of phase signal through voltage and inverting amplifier.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2001.11a
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• pp.28-35
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• 2001

The heat transfer and pressure drop characteristics of R718 flowing in smooth horizontal copper tubes with inner diameter of 3.36 mm, 5.35 mm, 6.54 mm and 8.12 mm were investigated. The test section is a counterflow heat exchanger with refrigerant flowing in the inner tube and water flowing in the annulus. Experiments were peformed for the flowing range of variables : Reynolds number (1000 to 20000), mass flow rate of brine (450 kg/h) and refrigerant temperature (5$0^{\circ}C$). The main results were summarized as follows : (1) The heat transfer coefficient of 3.36 mm ID was about 10% to 30% higher than that of 5.35 mm, 6.54 mm and 8.12 mm ID, and the heat transfer coefficients for small diameter. tubes are about 20% to 27% higher than these predicted by Gnielinski. The new correlation is proposed to predict the experimental data. (2) As a result of comparison with correlation prosed by Blasius. the deviation of the experimental data slightly increased as the tube diameter decreased. (3) The ratio of heat transfer to friction factor (j/f) correlated by all experimental data increased as the tube diameter decreased.

• The Korean Journal of Ecology
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• v.20 no.1
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• pp.35-41
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• 1997

Effects of cadmium on growth and nitrogen fixation activity of Melilotus suaveolens, a biennial legume plant dominating in the area of poor soil were quantitatively analyzed during the growing period. Cadmium treatments of 10, 30 and 100 ppm resulted in 12, 22 and 35% inhibition of plant height and 14, 25 nd 26% reduction of chlorophyll contents of leaves, respectively. The plant biomass reduced 51, 70 and 89% for leaves, 33, 50 and 59% for stems, and 42, 52 and 70% for roots, respectively by 10, 30 and 100 ppm Cd treatments. Cadmium contents of roots treated with 10, 30 and 100 ppm Cd were 62, 112 and 183 folds higher than that of the control, respectively. Cadmium contents of stems were about 1/2.2 of those of roots, but leaves contained only 1/27.8 of those of roots. Cadmium treatments resulted in increase of T/R ratios and decrease of F/C ratios significantly in the later growth period. Nodule formation was reduced to 8% in 42 days by the treatment of 100 ppm Cd. Specific nitrogen fixation activity of nodules attained 61.0, 24.0, 1.6 and 0.7 mol $C_2H_4{\cdot}g$ fr wt $nodule^{-1}{\cdot}h^{-1}$ on 42nd day, respectively for 0, 10. 30 and 100 ppm of Cd treatments. Total amount of nitrogen fixation per plant reduced by 73, 98 and 99% with the treatments of 10, 30 and 100 ppm Cd.

• Progress in Superconductivity
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• v.11 no.1
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• pp.30-35
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• 2009

We have investigated the characteristics of a superconductive Pb shield for hemispherical shape and plate to improving signal-to-noise ratio(SNR) of biomagnetism. We measured the shielding factor for the position of helmet shape Pb and for changing the distance from Pb surface. To make a uniform magnetic field, a $1.5m{\times}1.5m$ set of the helmholtz coils activated at several frequencies. The shielding factor of hemispherical shape Pb was from 20 to 57 dB and of Pb plate was about $6{\sim}26dB$ as a function of distance from the lead surface. The shielding factor was rapidly reduced as increasing the distance from Pb surface. The white noise of superconductive quantum interference device(SQUID) with a superconductive shield was about $12fT/Hz^{1/2}$ at 1 Hz, $7fT/Hz^{1/2}$ at 100 Hz. The white noise was more increased about two times than conventional SQUID system without Pb shielding. An auditory signal was measured by first order gradiometer and magnetometer with Pb superconductive shield and compared the SNR. The SQUID system with Pb shield had better performance at low frequency noise level.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.114-115
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• 2003

양식 생물에게 있어 용존산소는 호흡에 필수적이며, 양식 시설 내에서 적절한 용존 산소량을 유지하는 것은 생산량을 좌우하는 가장 중요한 요인이며, 어종, 수온, 광주기, 나이와 크기, 어류의 행동과 먹이 공급 및 환경 조건에 따라 달라진다. 이 중 같은 종 내에서 선발육종된 개체와 일반 양식 종 그리고 이들 계통간 잡종에 대한 대사 효율 즉, 용존산소 소비율의 차이에 관한 연구는 거의 없다. 따라서 본 실험에서는 한국해양연구원에서 선발육종 해 온 참돔과 일본 양식산 참돔 및 이들의 교배 자손들을 대상으로 수온과 광주기 변화에 따른 용존산소 소비율을 조사하였다. 실험어는 일본 양식산인 TPN 교배구 자손과 한국해양연구원 선발육종산인 KORDI F4 교배구 자손, JPN♀×KORDI F4♂ 그리고 KORDI F4♀×JPN♂ 교배구 자손을 대상으로 실시하였다. 체중이 각각 52.0±0.6 g(JPN 교배구; 그룹 1), 52.3±0.7 g(JPN♀×KORDI F4♂; 그룹 2), 51.7±0.4 g(KORDI F4♀ × KORDI F4♂; 그룹 3) 그리고 52.1±0.7 g(KORDI F4♀ × JPN♂; 그룹 4)인 참돔 치어를 각각 5마리씩 3반복 수용하여 실험에 이용하였다. 실험기간 동안 사육수의 pH는 8.1±0.1, 염분도는 34.0±0.5‰로 유지하였으며, 실험 장치는 김(1999)이 고안한 순환 시스템을 이용하였다. 수온은 각각 15℃, 20℃ 및 25℃로 변화시켰으며 각 수온 조건에서 광주기를 24L:0D, 12L:12D 그리고 0L:24D로 변화시켜 매 조건마다 용존 산소 소비량을 측정하였다. JPN 교배구인 그룹 1의 경우, 수온 15℃일 때 산소 소비량은 170.35∼266.29 mg O₂/kg fish/hr의 범위를 보였으며 수온 20℃와 25℃일 때 각각 236.76∼307.37 mg O₂/kg fish/hr와 346.96∼459.30 mg O₂/kg fish/hr 범위를 보여 수온 상승에 따라 산소 소비량 역시 증가하는 것으로 나타났다. 그룹 2의 경우, 수온 15℃일 때 산소 소비량은 162.01∼279.51 mg O₂/kg fish/hr의 범위를 보였으며 수온 20℃와 25℃일 때 각각 303.48∼342.72 mg O₂/kg fish/hr와 447.18∼528.45 mg O₂/kg fish/hr 범위를 보여 그룹 1과 마찬가지로 수온 상승에 따라 산소 소비량 역시 증가하는 것으로 나타났다. 그룹 3의 경우, 수온 15℃일 때 산소 소비량은 170.11∼220.98 mg O₂/kg fish/hr의 범위를 보였으며 수온 20℃와 25℃일 때 각각 262.62∼282.27 mg O₂/kg fish/hr와 302.24∼415.73 mg O₂/kg fish/hr 범위를 보여 그룹 1, 2와 유사한 경향을 보였다. 그룹 4의 경우, 수온 15℃일 때 산소 소비량은 156.03∼214.49 mg O₂/kg fish/hr의 범위를 보였으며 수온 20℃와 25℃일 때 각각 238.40∼274.28 mg O₂/kg fish/hr와 379.93∼430.97 mg O₂/kg fish/hr 범위를 보여 수온 상승에 따라 산소 소비량 역시 증가하는 것으로 나타나, 그룹 1, 2와 유사한 경향을 보였다. 모든 실험구에서 수온 상승과 함께 산소 소비량이 증가하는 것으로 나타났으며 가장 높은 산소 소비량은 그룹 2에서 관찰되었다. 실험 결과 JPN 계통의 암컷을 사용하여 생산된 그룹 1과 2의 산소 소비량이 KORDI F4 계통의 암컷을 사용한 그룹 3, 4보다 대체적으로 높은 것으로 나타났다. 연속적인 명기 조건인 24L:0D에서 수온 15℃의 경우 그룹 1, 2, 3 그리고 4의 시간당 산소 소비량은 각각 266.29 mg O₂/kg fish/hr,279.51 mg O₂/kg fish/hr, 220.98 mg O₂/kg fish/hr 그리고 214.49 mg O₂/kg fish/hr으로 나타났고, 명기와 암기가 동일한 조건인 12L:12D에서는 각각 192.20 mg O₂/kg fish/hr, 258.03 mg O₂/kg fish/hr, 192.76 mg O₂/kg fish/hr 그리고 170.40 mg O₂/kg fish/hr로 나타났다. 또한 연속적인 암기 조건인 OL:24D 조건에서는 각각 170.35 mg O₂/kg fish/hr, 162.01 mg O₂/kg fish/hr, 170.11 mg O₂/kg fish/hr 그리고 156.03 mg O₂,/kg fish/hr로 나타났다. 그리고 수온 20℃와 25℃에서도 그룹간의 변화는 이와 비슷한 경향을 보였다. 연속 명기 조건인 24L:0D에서의 산소 소비량이 명기와 암기가 동일한 조건인 12L:12D와 연속 암기 조건인 0L:24D에서의 산소 소비량 보다 대체적으로 높은 것으로 나타났으며, 그룹 2의 연속 명기 조건에서 528.45 mg O₂/kg fish/hr으로 가장 높게 나타났다. 그룹 4에서는 대사량이 점점 더 높아지는 수온 상승과 함께 연속 명기 조건과 더불어 12L:12D 조건에서의 산소 소비량이 크게 증가하는 것으로 나타났다.