• Journal of Embryo Transfer
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• v.9 no.2
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• pp.145-152
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• 1994

The suitable electric stimulation is essential for activation and fusion of oocytes before or after nuclear transplantation The present study was undertaken to determine the optirnal condition for the parthenogenetic activation of in vitro rnatured(IVM) bovine oocytes by electric stimulation. Different direct current(DC) electric voltage of 1.0, 1.5 and 2.0 kV/cm and pulse duration of 30, 60 and 120 $\mu$sec were applied to the JVM nocytes in 0.3 M mannitol solution containing each 100 $\mu$M CaCl$_2$ and MgCl$_2$. IVM occytes at 24, 28 and 32 hours Post-maturation(hpm) were also electrically stimulated at 1.5 kV /cm, for 60 $\mu$ sec. The stimulated nocytes were then co-cultured in TCM-199 solution containing 10% fetal calf serum with bovine oviductal epithelial cells for 7~9 days in a 5% $CO_2$ incubator at 39$^{\circ}C$ ~ Their activation and in vitro development to morula and blastocyst were assessed under an inverted microscope. The higher activation rates 62.8 and 63.4% and in vitro de- velopment rates to morula and blastocyst 5.1 and 10.9% were shown in the oocytes stimulated at the voltage of 1.0 and 1.5 kV/cm than 2.0 kV/cm, respectively. No signifi- cantly(P<0.05) different activation rate was shown in JVM oocytes stimulated for 30, 60 and 120 $\mu$sec, but developmental rates to morula and blastocyst was significantly(P<0.05) higher in the oocytes stimulated for 30 $\mu$sec(6~3%) and 60 $\mu$sec(10~0%) than 120 $\mu$sec(0~ 0%). The aged oocytes at 28 and 30 hpm showed significantly(P<0.05) higher activation rates(72~7 and 79.7%) than the oocytes at 24 hpm(50~9%)~ Also, their developmental rates to morula and blastocyst were significantly(P<0.05) higher in the nocytes at 28(14.3%) and 32 hpm(15.9%) than 24 hpm(3.6%). From these results, it can be suggested that the optimal electric stimulation for IVM bovine occytes is a DC voltage between 1.0 and 1.5 kV/cm, pulse duration of 30 or 60 $\mu$sec, and the optimal age of IVM oocytes for electric activation is at 32 hpm.

• Food Science and Preservation
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• v.12 no.1
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• pp.80-85
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• 2005

The effect of 12 edible mushroom species on the antioxidant and cytotoxicity on cancer cells were studied Methanol extract of Lyophyllum ulmarium, Cordyceps militaris and Sarcodon aspratus showed $30\~60\%$ DPPH radical scavenging activity and $39\~53\%$ protective effects against the cytotoxicity of $B_2O_2$. Methanol extracts of Sarcodon aspratus, Lyophyllum ulmarium, Cordyceps militaris, Agaricus blazei and Ganoderma lucidum revealed high inhibitive activities in cytotoxicity on human leukemia tells such as promyelocytic leukemia cell (HL60) and histiocytic lymphoma cell (U937). Highest toxicity was observed against HL60 cells in Sarcodon aspratus methanol extract showing $70.5\%$ inhibition at 1mg/mL whereas Cordyceps militaris methanol extract showed $81.5\%$ inhibition against U937 cells. Most water extracts of edible mushrooms exhibited the lowest effect against HL60 and U937 cells compared to methanol extract. These extract did not show cytotoxic effects against human lymphocyte. Results revealed 5 kinds of edible murshroom (Cordyceps militaris, Agaricus blaxei, Lyophyllum ulmarium, Ganoderma lucidum and Sarcodon aspratus) have strong antioxidative and in vitro anticancer efforts.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.3 s.58
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• pp.161-171
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• 2006

In this study, we investigated the whitening and anti-oxidant activity of 37 Jeju island native plants. The active ingredients of the plants were prepared by methanol extraction. Whitening activity of plant extracts was examined from the inhibitory effect of tyrosinase and the inhibition of melanin synthesis of the B16-F1 cell line. Their anti-oxidant activity was measured by electron donating ability of DPPH (1,1-diphenyl-2-picrylhydrazyl) and ROS (reactive oxygen species) scavenging activity in V79-4 lung fibroblast cells using DCF-DA (dichlorofluorescin diacetate). Cytotoxicity of the extracts on cell s based experiments was investigated by MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) assay. Also, the toxicity test using a rabbit and the human skin patch test were carried out for examining the safety of the extracts which showed the high whitening activity. It is interesting that the extracts of Lespedeza cuneata, Ligustrum lucidum (stem), Morus bombycis (stem) and Prunella vulgaris var. lilacina showed both potent whitening and anti-oxidant activities.

• Korean journal of food and cookery science
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• v.24 no.6
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• pp.729-734
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• 2008

The principal objective of this study was to assess the possibility of transforming platycodin glycosides using various strains of probiotic bateria and edible fungi. Among the experimental microorganisms assess herein, Aspergillus niger KCTC 6909 evidenced the highest level of platycodin glycoside hydrolysis during fermentation. Particularly in cases in which the organism was incubated in the presence of rhamnose and platycodins. In order to produce the enzyme from Aspergillus niger effectively, various incubation conditions were assessd in order to determine the optimal conditions. The cytotoxicity on V79-4 (Chinese- hamster lung fibroblasts, normal cells) of platycodin was reduced significantly after conversion (concentration on $500{\mu}g/mL$, $1000{\mu}g/mL$); DPPH radical scavenging activity before conversion was 35.05%, and was 57.44% afterward. We noted significantly higher conversion activity inhibiting oxidative degradation. In conclusion, these results indicate that the proper combination of food microorganisms -and fermentation conditions can result in an increase in the glycoside hydrolysis of platycodin the resultant products of which reduce cytotoxicity- and increase anti-oxidant activity.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.4
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• pp.51-59
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• 2019

In this study, the influence of anaerobic digested sludge and 50 mM PBS (phosphate buffer solution) mixing ratio (1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7) on hydrogen production and inoculation period were examined. MECs were operated in fed-batch mode with an applied voltage of 0.9 V. As a result, in the 1:1 mixing ratio reactor, 9.8-20.9 mL of hydrogen was produced with the highest hydrogen content of 66.8-79.6%. Hydrogen gas production and power density increased from after 12 days of inoculation for the 1:1 mixing ratio reactor. In case of 1:2, 1:3 and 1:4 mixing ratio reactor, the hydrogen gas production was 3.7-7.1 mL and the hydrogen gas content was 5.8-65.8%. The hydrogen gas yield in 1:5, 1:6 and 1:7 ratio reactors, was 0.50-0.69 mL and hydrogen content range was 1.8-7.1%. The mixing ratio was found to be suitable for hydrogen production and inoculation period by mixing ratio up to 1:4.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.242-247
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• 2019

Biological factors (e.g. microorganism activity) in wastewater treatment plant (WWTP) play essential roles for degradation and/or removal of organic matters. In this study, to understand the microbial functional roles in WWTP, we tried to isolate and characterize a bacterial strain from activated sludge sample. Strain S16 was isolated from the activated sludge of a municipal WWTP in Daejeon metropolitan city, the Republic of Korea. The cells were a Gram-stain-positive, non-motile, facultative anaerobe, and rod-shaped. Strain S16 grew at a temperature of $15{\sim}40^{\circ}C$ (optimum, $30^{\circ}C$), with 0~9.0% (w/v) NaCl (optimum, 1.0~2.0%), and at pH 5.5~9.0 (optimum, pH 7.0~7.5). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain S16 was most closely related to the unique species Miniimonas arenae NBRC $106267^T$ (99.79%, 16S rRNA gene sequence similarity) of the genus Miniimonas. The cell wall contained alanine, glutamic acid, serine, and ornithine. Although the isolation source of the type strain NBRC $106267^T$ which considered as a marine microorganism is sea sand, that of strain S16 is terrestrial environment. It might raise an ecological question for habitat transition. Therefore, comparative genome analysis will be valuable investigation for shedding light on their potential metabolic traits and genomic streamlining.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.1
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• pp.73-79
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• 2013

Crystalline silicon solar cells with $SiN_x/SiN_x$ and $SiN_x/SiO_x$ double layer anti-reflection coatings(ARC) were studied in this paper. Optimizing passivation effect and optical properties of $SiN_x$ and $SiO_x$ layer deposited by PECVD was performed prior to double layer application. When the refractive index (n) of silicon nitride was varied in range of 1.9~2.3, silicon wafer deposited with silicon nitride layer of 80 nm thickness and n= 2.2 showed the effective lifetime of $1,370{\mu}m$. Silicon nitride with n= 1.9 had the smallest extinction coefficient among these conditions. Silicon oxide layer with 110 nm thickness and n= 1.46 showed the extinction coefficient spectrum near to zero in the 300~1,100 nm region, similar to silicon nitride with n= 1.9. Thus silicon nitride with n= 1.9 and silicon oxide with n= 1.46 would be proper as the upper ARC layer with low extinction coefficient, and silicon nitride with n=2.2 as the lower layer with good passivation effect. As a result, the double layer AR coated silicon wafer showed lower surface reflection and so more light absorption, compared with $SiN_x$ single layer. With the completed solar cell with $SiN_x/SiN_x$ of n= 2.2/1.9 and $SiN_x/SiO_x$ of n= 2.2/1.46, the electrical characteristics was improved as ${\Delta}V_{oc}$= 3.7 mV, ${\Delta}_{sc}=0.11mA/cm^2$ and ${\Delta}V_{oc}$=5.2 mV, ${\Delta}J_{sc}=0.23mA/cm^2$, respectively. It led to the efficiency improvement as 0.1% and 0.23%.

• Reproductive and Developmental Biology
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• v.29 no.2
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• pp.127-131
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• 2005

The objective of this study was to examine the effect of EGF on meiotic maturation and pronuclear (PN) formation of porcine oocytes. Prepubertal gilt cumulus-oocyte-complexes (COCs) aspirated from $2\~6mm$ follicles of abbatoir ovaries were matured in TCM199 containing 0.1mg/ml cysteine, $0.5{\mu}/ml$ FSH and LH, and EGF (0, 5, 10, 20, 40 ng/ml) for 22 hr at $39^{\circ}C$ in a humidified atmosphere of $5\%$ $CO_2$ in air. They were then cultured for an additional 22hr without hormones. In Experiment 1, to examine the nuclear maturation at 44hr of culture, the expanded cumulus cells were removed by vortexing for 1 min in 3 mg/ml hyaluronidase. The oocytes were fixed in acetic acid: methanol (1:3, v/v) at least for 48 hr and stained with $1\%$ orcein solution for 5 min. Nuclear status was classified as germinal vesicle (GV), germinal vesicle breakdown (GVBD), prophase-metaphase I (PI-MI), and PII-MII under microscope. In Experiment 2, to investigate PN formation, oocytes were fertilized with Percoll-treated freshly ejaculated sperm $(1\times10^5\; cells/ml)$ in mTBM with $0.3\%$ BSA and 2mM caffeine for 5hr, and cultured in NCSU-23 medium with $0.4\%$ BSA. At 6hr of culture, the embryos were fixed in $3.7\%$ formaldehyde for 48hr and stained with 10ug/ml propidium iodide for 30 min. PN status was classified as no or one PN (unfertilized), 2 PN (normal fertilized) and $\geq3$ PN (polyspermy). Differences between groups were analyzed using one-way ANOVA after arc-sine transformation of the proportional data. The rate of oocytes that had reached to PII-MII were significantly (P<0.05) higher in all groups added EGF than that of non-treated group $(67\%)$, but it did not differ among the all added groups $(86\%,\;85\%,\;79\%\;and\;81\%$, in 5, 10, 20 and 40 ng/ml EGF, respectively). No differences on the incidence of 2PN were observed in all treated groups $(25\%,\;30\%,\;33\%,\;29\%\;and\;29\%$, in 0, 5, 10, 20 and 40 ng/ml EGF, respectively), however, in non-treated group, polyspermy tended to be increased ($66\%\;vs\;. 58\%,\;54\%,\;52\%\;and\;55\%$, 0 vs. 5, 10, 20, 40 ng/ml EGF, respectively). These results suggest that EGF can be effectively used as an additive for enhancing oocyte maturation and reducing the incidence of polyspermy in pig.

• The Korean Journal of Physiology and Pharmacology
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• v.7 no.5
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• pp.267-273
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• 2003

We have investigated the effect on inducing substate(s) of positively charged residues replaced in position 172 of the second transmembrane domain in murine inward rectifier potassium channels, formed by stable or transient transfection of Kir2.1 gene in MEL or CHO cells. Single channel recordings were obtained from either cell-attached patches or inside-out patches excised into solution containing 10 mM EDTA to rule out the effect of $Mg^{2+}$ on the channel gating. The substate(s) could be recorded with all mutants D172H, D172K and D172R. The unitary current-voltage (I-V) relation was not linear with D172H at $pH_i$ 6.3, whereas the unitary I-V relation was linear at $pH_i$ 8.0. The relative occupancy at $S_{LC}$ was increased from 0.018 at $pH_i$ 8.0 to 0.45 at $pH_i$ 5.5. In H-N dimer, that was increased from 0.016 at $pH_i$ 8.0 to 0.23 at $pH_i$ 5.5. The larger the size of the side chain or $pK_a$ with mutants (D172H, D172K and D172R), the more frequent the transitions between the fully open state and substate within an opening. The conductance of the substate also depended upon the pKa or the size of the side chain. The relative occupancy at substate $S_{LC}$ with monomer D172K (0.50) was less than that in K-H dimer (0.83). However, the relative occupancy at substate with D172R (0.79) was similar to that with R-N dimer (0.82). In the contrary to ROMK1, positive charge as well as negative charge in position 172 can induce the substate rather than block the pore in murine Kir2.1. The single channel properties of the mutant, that is, unitary I-V relation, the voltage dependence of the mean open time and relative occupancy of the substates and the increased latency to the first opening, explain the intrinsic gating observed in whole cell recordings.

• Journal of Embryo Transfer
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• v.10 no.1
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• pp.73-82
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• 1995

large scale production of cloned embryos requires the technology of multiple generation nuclear transplantation(NT) using NT embryos as the subsequent donor nuclei. The purposes of this study were producing the second generation cloned rabbit embryos, and also to determine the electrofusion rate and in vitro developmental potential comparatively in the cloned embryos of the first and second NT generation. The embryos of 16-cell stage were collected from the mated does by flushing oviducts with Dulbecco's phosphate buffered saline(D-PBS) containing 10% fetal calf serum(FCS) at 47 hours after hCG injection In the first generation NT, the nuclear donor embryos were synchronized in the phase of Gi /S transition of 32-cell stage. The first generation NT embryos which were developed to 8-cell were synchronized in Gi /S transition phase of the following 16-cell stage and used as donor nuclei for second generation Synchronization of the cell cycle of blastomeres was induced, first, using an inhibitor of microtuble polymerization, colcemid for 10 hours to arrest blastomeres in M phase, and secondly, using a DNA synthesis inhibitor, aphidicolin for 1.5 to 2 hours to arrest them in Gi /S transition boundary. The recipient cytoplasms were obtained by removing the nucleus and the first polar body from the oocytes collected at 14 hours after hCG injection. The separated donor blastomeres were injected into the enucleated recipient oocytes by micromanipulation and were electrofused by electrical stimulation of three pulses for 60 $\mu$sec at 1.25 kV /cm in 0.28 M rnannitol solution The fused oocytes were co-cultured with a monolayer of rabbit oviductal epithelial cells in M-199 solution containing 10% FCS for 120 hours at 39$^{\circ}C$ in a 5% $CO_2$ incubator. Following in vitro culture of the first and second generation cloned embryos to blastocyst stage, they were stained with Hoechst 33342 dye for counting the number of blastomeres by fluorescence microscopy. The results obtained were summarized as follows: 1. The electrofusion rate was found to be similar as 79.4 and 91.5% in the first and second generation NT rabbit embryos, respectively. 2. The in vitro developmental potential to blastocyst stage of the second generation NT embryos (23.3%) was found significantly(p<0.05) lower, compared with that of the first generation NT embryos (56.8%). 3. The mean blastomeres counts of embryos developed to blastosyst stage following in vitro culture for 120 hours and also their daily cell cycles during the culture period were decreased significantly (p<0.05) to 104.3 cells and 1.33 cylces in the second NT generation, compoared with 210.4 cells and 1.54 cycles in the first NT generation, respectively.