• The Korean Journal of Zoology
• /
• v.29 no.2
• /
• pp.141-158
• /
• 1986

A glutathione peroxidase from white rat (Wistar strain)erythrocytes was partially purified and characterized. In addition, localization of this enzyme in the liver was studied by histochemical method. A glutathione peroxidase was purified approximately 33.5-folds by ammonium sulfate precipitation, Sephadex filtration column and DEAE-Sephadex column chromatography. The optimum temperature of the crude glutathione peroxidase was $40^\\circC$, and the optimum pH was 7.5. This crude glutathione peroxidase was most stable at $30^\\circC$ and the values of Km and Vmax were calculated to be 8.5mM and 15.6 $\\mu$moles/min for glutathione, and 40 $\\mu$M and 10.5 $\\mu$moles/min for hydrogen peroxide, respectively. The molecular weight of this enzyme was estimated by Sephadex G-200 gel filtration to be approximately 90, 000. By electron microscopic examination, histochemical reaction products were microbodies that were prominent in the peripheral parts of the lobule. The reaction products exhibited round shapes, the diameter of which varied $0.2\\sim0.7 \\muM$ and their boundary membranes were not distint.

• Journal of Korean Ophthalmic Optics Society
• /
• v.12 no.2
• /
• pp.61-66
• /
• 2007

This study was to analysis the values for anterior and posterior Best-Fit Sphere(BFS) in a Korean emmetropic population using the Orbscan II system. Cycloplegic refraction and anterior and posterior BFS were performed 40 eyes of 20 patients and we compared the results by sex and between the two eyes. Respectively, the 1, 3, 5mm zone average of anterior BFS showed each $5.63{\pm}3.49{\mu}m$, $4.48{\pm}2.81{\mu}m$ and $2.14{\pm}1.82{\mu}m$. The 1, 3, 5mm zone average of posterior BFS showed each $22.54{\pm}10.25{\mu}m$, $15.88{\pm}7.55{\mu}m$ and $4.43{\pm}4.94{\mu}m$ in 40 emmetropic eyes. Anterior and posterior BFS were not statistically significant difference in male and female using Mann-Witney U test.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.40 no.6
• /
• pp.387-393
• /
• 2007

We examined the conditions for separating and preserving the male and female gametophytes of Kjellmaniella crassifolia. The highest percentage of zygote germination (85%) was on semi-solid medium composed of 1.0% transfer gel agar at $15\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$ after a 4-week culture. Zygote germination in PESI liquid medium was 93.5% at $20\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$. The maximum zygote growth was $252{\pm}19.7\;{\mu}m$ on 1.0% transfer gel agar at $15\;^{\circ}C$ and $40\;{\mu}mol/m^2/s$ after 5-week culture, and was $76.7{\pm}2.8\;{\mu}m$ in PESI liquid medium at $20\;^{\circ}C$ and $40\;{\mu}mol/m^2/s$. The respective numbers of separated male and female gametophytes from germinated zygotes were 157 and 93 on 1.0% transfer gel agar and 14 and 28 in PESI liquid medium. The maximum growth of separated male and female gametophytes was $575{\pm}28.3\;{\mu}m$ at $5\;^{\circ}C$ and $60\;{\mu}mol/m^2/s$ and $686{\pm}35.4\;{\mu}m$ at $20\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$ in PESI liquid medium after 3 weeks, respectively. The highest percentage fertilized was $93.3{\pm}5.8%$ at $15\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$ in PESI liquid medium. These results show that the best conditions for the separation and preservation of gametophytes (male and female) consisted of culturing on 1.0% transfer gel agar at $15\;^{\circ}C$ and $20\;{\mu}mol/m^2/s$.

• Journal of the Korean Vacuum Society
• /
• v.17 no.3
• /
• pp.234-239
• /
• 2008

Tungsten and rhodium target tube for a 40 kV x-ray transmission anode was developed to apply to the hand-held XRF(X-Ray Fluorescence) apparatus and its characteristics were evaluated. From the measurement of the energy distribution and dose of x-ray, it was confirmed that our results were good agreements with the known ones. The optimum thickness of metal film deposited on Be window to extract the maximum dose were $2.6{\mu}m$ and $2.7{\mu}m$ in case of W-target tube and Rh-target tube, respectively. When it was continuously worked during 30 min. at 40 kV in tube voltage and at $60{\mu}A$ in tube current, the temperature at target did not exceed $50^{\circ}C$. Our results reveals that the 40 kV x-ray transmission anode tube can be applied to the hand-held XRF apparatus.

• Korean Journal of Animal Reproduction
• /
• v.24 no.3
• /
• pp.231-239
• /
• 2000

In this study, we observed the effects of dioxin on weights of body, testes and other organs, the number and motility of sperm in the a various dose after two days' of administration in mice. Animals were treated with oral dose of dioxin 10, 20, 30, 40 mg/kg body weight, respectively. 1, After administration dioxin at doses of 10, 20, 30 and 40 $\mu\textrm{g}$/kg to the mice, the changes in body weights were 30.6 $\pm$ 2.g~40.7 $\pm$ 3.9g and 30.8 $\pm$4.1g~39.5g $\pm$3.1 for 10 and 20 $\mu\textrm{g}$/kg dosed group, 31.0 $\pm$ 3.5g ~ 39.0 $\pm$ 3.5g, 30.6 $\pm$ 3.4g~38.3 $\pm$ 4.0g for 30 and 40 $\mu\textrm{g}$/kg dosed group. The body weight of dioxin-administered group showed lower value when compared to 30.6 $\pm$ 2.8g ~ 44.5 $\pm$ 3.1g of which is control group's. 2. After administration of dioxin at doses of 10, 20, 30 and 40 $\mu\textrm{g}$/kg to the mice, the increase in the number of WBC was prominent, but the increase in the number of RBC wasn't significant, though the values of Hb, PCV, and PLT were higher than those of control group's. 3. After administration of dioxin at doses of 10. 20, 30 and 40 $\mu\textrm{g}$/kg to the mice, the changes in sperm number were 112.5 $\pm$ 3.7~119.4 $\pm$4.2 $\times$ 10$^{6}$ $m\ell$, 103.9 $\pm$3.8 ~ 110.2 $\pm$ 3.6 $\times$ 10$^{6}$ $m\ell$, 97.5 $\pm$ 3.4 ~105.7 $\pm$ 4.4 $\times$ 10$^{6}$ $m\ell$, 87.2 $\pm$ 3.7~98.5 $\pm$ 3.8 $\times$ 10$^{6}$ $m\ell$, respectively. The sperm number of dioxin-administered group showed lower value than that of control group's, which was 119.0 $\pm$ 4.3 ~ 120.7 $\pm$ 4.8 $\times$ 10$^{6}$ $m\ell$. After administration of dioxin at doses of 10~40 $\mu\textrm{g}$/kg to the mice, the sperm motility were 69.4$\pm$ 3.0 ~ 86.6 $\pm$4.7%. The sperm motility of dioxin-administered group showed lower value than that of control group's. 4. After administration of dioxin at doses of 10, 20, 30 and 40$\mu\textrm{g}$/kg to the mice, the organ weight of each dioxin-administered group's was decreased a little compared to that of control group's. 5. After administration of dioxin at doses of 10, 20, 30 and 40 $\mu\textrm{g}$/kg to the mice, the weights of spleen, kidneys, and liver showed increase a little.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.12
• /
• pp.1635-1641
• /
• 2011

This study was designed to investigate antioxidant activities of pomegranate endocarp extracts. Pomegranate endocarp extract contains the highest antioxidant function compared to pomegranate extracts from other parts. Pomegranate endocarp extract was fractionated with hexane, dichloromethane, ethyl acetate, butanol extract, and water, followed by evaluation for antioxidant activity. During this experiment, various antioxidant tests such as nitrite scavenging activity, reducing power, superoxide anion scavenging activity, $ABTS^+$ scavenging activity, SOD like-activity, and DPPH radical scavenging activity were conducted on the $CH_2Cl_2$, EtOAc, BuOH, $H_2O$ fractions of pomegranate endocarp extract. Results showed that the ethyl acetate fraction contained the highest DPPH radical scavenging activity among the samples. For SOD like-activity, the dichloromethane fraction had the highest antioxidant activity. For superoxide anion scavenging activity, the ethyl acetate fraction had the highest antioxidant activity. In the $ABTS^+$ scavenging activity test, the ethyl acetate fraction $IC_{50}$ was 39.26 ${\mu}g$/mL, whereas that of the butanol fraction was 40.95 ${\mu}g$/mL. In testing reduction power at 0.1 mg/mL, the O.D. of the ethyl acetate fraction was highest at 1.404 and showed higher activity than ascorbic acid at 1.332. The results of the nitrite scavenging activity test were very similar to those of the SOD like-activity test. These results suggest that pomegranate endocarp extract may have value as a natural antioxidant.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.05a
• /
• pp.95-98
• /
• 2012

This paper describes a multiphase delay-locked loop (DLL) that generates a 32-phase output clock over the operating frequency range of 40 MHz to 280 MHz. The matrix-based delay line is used for high resolution of 1-bit delay. A calibration scheme, which improves the linearity of a delay line, is achieved by calibrating the nonlinearity of the input stage of the matrix. The multi-phase DLL is fabricated by using 0.11-${\mu}m$ CMOS process with a 1.2 V supply. At the operating frequency of 125MHz, the measurement results shows that the DNL is less than +0.51/-0.12 LSB, and the measured peak-to-peak jitter of the multi-phase DLL is 30 ps with input peak-to-peak jitter of 12.9 ps. The area and power consumption of the implemented DLL are $480{\times}550{\mu}m^2$ and 9.6 mW at the supply voltage of 1.2 V, respectively.

• The Korean Journal of Mycology
• /
• v.40 no.4
• /
• pp.277-281
• /
• 2012

Bacillus sp. NAAS-1 isolated from the field of Chili pepper was tested for biocontrol activity against anthracnose pathogen of Chili pepper caused by Colletotrichum acutatum. The antifungal activity of Bacillus sp. NAAS-1 culture broth was compared with synthetic fungicide containing carbendazim (40%) and kasugamycin (3.45%). Bacillus sp. NAAS-1 showed a similar fungicidal activity against the anthracnose pathogen at the concentration of 50 ${\mu}L/mL$ in comparison to the fungicide containing carbendazim (40%) and kasugamycin (3.45%) using a cup method. Bacillus sp. NAAS-1 also exhibited its potent fungicidal activity against the anthracnose in vivo test at the concentration of 50 ${\mu}L/mL$ when compared to the fungicide containing carbendazim (40%) and kasugamycin (3.45%).

• Journal of the Korean Institute of Gas
• /
• v.16 no.5
• /
• pp.7-13
• /
• 2012

An experimental study has been done to investigate the explosion characteristics of aluminum powders with different sizes and concentrations in a 20 L spherical explosion vessel. Two different sizes of aluminum powder were used : $15.1{\mu}m$ and $34.8{\mu}m$ with a volume mean diameter. The results revealed that $15.1{\mu}m$ Al powder has a Lower explosion limit (LEL) of $40g/m^3$, a maximun explosion pressure ($P_{max}$) of 9.8 bar and a maximum rate of pressure rise ($[dP/dt]_{max}$) of 1852 bar/s, in $34.8{\mu}m$ Al powder, LEL of $70g/m^3$, $P_{max}$ of 7.9 bar and $[dP/dt]_{max}$ of 322 bar/s. The LEL of Al powders tended to increase with the increase of particle size. Also, it was found that the flame velocity calculated from the powder with $15.1{\mu}m$ was about 5 times higher than that of the powder of $34.8{\mu}m$.

• The Korean Journal of Food And Nutrition
• /
• v.22 no.2
• /
• pp.308-312
• /
• 2009

In this study, the effects of low molecular weight chitooligosaccharides were assessed. Low molecular weight chitooligosaccharide evidenced no cytotoxicity in in vitro trials with the normal cell line, Vero E6(Africa green monkey kidney cell). The $IC_{50}$ of low molecular weight chitooligosaccharide was $923.20{\mu}g/m{\ell}$. Low molecular weight chitooligosaccharide exhibited in vitro antineoplastic activity in five human tumor(lung carcinoma, bladder carcinoma, colon carcinoma, stomach carcinoma, breast carcinoma) cell lines. The $IC_{50}$ values of low molecular weight chitooligosaccharide on A549, J82, SNU-C4, SNU-1 and ZR75-1 were $477.42{\mu}g/m{\ell}$, $480.40{\mu}g/m{\ell}$, $436.84{\mu}g/m{\ell}$, $373.55{\mu}g/m{\ell}$, and $539.95{\mu}g/m{\ell}$, respectively.