• Journal of Embryo Transfer
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• v.26 no.1
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• pp.65-70
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• 2011

This study was conducted to investigate the survival rate of AndroMed and Tris-egg yolk extender for cryopreservation of Korean Native Bull Semen (Chick Cow). Semen was collected from a Korean Native Bull Semen over 3 year's old. The semen was diluted 1:1 by AndroMed and Tris-egg yolk extender. The pellet was diluted to final sperm concentration of $5{\times}10^7$ cell/ml by doubling in every 10 minutes at $4^{\circ}C$ cold chamber. The semen was equilibrated for 1 hrs at cold chamber and packed to 0.5 ml straw. The semen straws were located above 5 cm of liquid nitrogen for 5 minutes. And then the frozen straw was plunged to LN2. The presented straws were examined the viability and motility after thawed at $37^{\circ}C$ water bath. The survival rates was significantly higher (p<0.05) in Tris-egg yolk extender than AndroMed extender ($89.7{\pm}19.8$ vs. $73.4{\pm}11.2$). However, motility was no significant differences ($78.4{\pm}18.7$ vs. $67.9{\pm}14.6$). Survival rate in time of equilibration between visual and CASA program had higher in 2 h ($86.33{\pm}9.4$ vs. $92.32{\pm}12.4$) than in 5 h ($78.20{\pm}7.8$ vs. $88.28{\pm}13.1$) 15 h ($65.24{\pm}6.6$ vs. $76.48{\pm}17.3$) 20 h ($56.26{\pm}4.6$ vs. $67.73{\pm}18.4$). The development rates to cleavage was higher in Tris-egg yolk extender than AndroMed extender (82.2% vs. 81.7%). Similarly, the development rates to blastocyst was significantly higher (p<0.05) in Tris-egg yolk extender than AndroMed extender (42.3% vs. 29.6%). In conclusion, the obvious impact of this study will be its practical application to improve viability and fertilizing ability of cryopreserved spermatozoa used for in vitro fertilization (IVF) and AI, Which in turn will be beneficial to animal genetic resources conservation.

• Korean Journal of Weed Science
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• v.11 no.1
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• pp.50-59
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• 1991

Residual period and carry-over effect of some herbicides were determined using a bioassay method in six summer crops(potato, carrot, corn, water melon, soybean, and sesame). The effects were measured at regular time intervals after applying different rates of the herbicides. There were no great differences in residual period and carry-over injury between the soils and kinds of crops used. However, the residual period varied with the herbicides studied and the carry-over injury was dependent upon season and rate of the herbicide application, sampling depth of soil, and kind and seeding date of the test plant. When the residual herbicides were applied, the carry-over injury could be minimized by selecting tolernet crops, delaying seeding of the crops after application of the herbicides, and regulating the cultivation depth. Herbicides which showed no residual effect by the end of the cropping period(100-120 days for summer crops) and no carry-over effect were alachlor, trifluralin, ethalfluralin, metribuzin, and prometryn. When pendimethalin, metolachlor, linuron, methabenzthiazuron, and simazine were applied at the recommended rate or less, there was no carry -over injury at harvesting time. With doubling the recommended rate, however, the carry-over effect was found in sensitive crops. Napropamide applied at the rate of 300 g a.i./10 a brought about carry-over injury for Italian ryegrass and barley at 140 days in summer crops, whereas the injury was not found in Cruciferae (radish, Chinese cabbage). Nitralin applied at the rate of 150-300 g a.i./10a caused the carry-over injury for Italian ryegrass and barley at 140 days in summer crops. However, there was no injury for Cruciferae.

• Korean Journal of Weed Science
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• v.11 no.1
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• pp.32-49
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• 1991

Residual period and carry-over effect of some herbicides were determined using a bioassay method in five winter crops (chinese cabbage, radish, spinach, onion and garlic). The effects were measured at regular time intervals after applling different rates of the herbicides. There were no great differences in residual period and carry-over injury between the soils and kinds of crops used. However, the residual period varied with the herbicides studied and the carry-over injury was rate of the herbicide application, sampling depth of soil, and kind and seeding date of the test plant. When the residual herbicides were applied, the carry-over injury could be minimized by selecting tolerant crops, delaying seeding of the crops after application of the herbicides, and regulating the cultivation depth. Herbicides which showed no residual effect by the end of the cropping period (200-240 days for winter crops) and no carry-over effect were alachlor, trifluralin, ethalfluralin and prometryn. When pendimethalin, metolachlor, linuron and methabenthiazuron were applied at the recommended rate or less, there was no carry-over injury at harvesting time. With doubling the recommended rate, however, the carry-over effect was found in sensitive crops. Napropamide applied in winter crops at rate of 150-300g a.i./10a brought about carry-over injury for such Gramineae as Italian ryegrass, direct-seeded rice and barley, whereas the injury was not found in lowland-transplanted rice, Cruciferae, Cucurbitaceae and Solanaceae. Long residual herbicide nitralin applied at the rate of 75g a.i./10a caused the carry-over injury for Italian ryegrass, direct-seeded rice, baley and lowland-transplanted rice at 275 days in winter crops. In addition, a slight injury occurred in sesame, perilla and spinach, However, there was no injury for Cruciferae, Cucurbitaceae and Solanaceae.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.449-456
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• 2014

Life table analysis and temperature-dependent development experiments were conducted to understand the biological characteristics of the cabbage aphid, Brevicoryne brassicae (Linnaeus) on detached Tah Tsai Chinese cabbage (Brassica campestris var. narinosa) leaves at seven constant temperatures (15, 18, 21, 24, 27, 30 and $33{\pm}1^{\circ}C$; $65{\pm}5%$ RH; 16L:8D). Mortality was lowest at $24^{\circ}C$ with 18% and 0% at $1^{st}{\sim}2^{nd}$ and $3^{rd}{\sim}4^{th}$ nymphal stages, respectively. The developmental period of $1^{st}{\sim}2^{nd}$ nymphal stage was 8.4 days at $18^{\circ}C$, and it decreased with increasing temperature. The developmental period of the $3^{rd}{\sim}4^{th}$ nymphal stage was 6.7 days at $18^{\circ}C$. The lower threshold temperature calculated using a linear model was $7.8^{\circ}C$, and the effective accumulative temperature was 120.1DD. Adult longevity was 14.9 days at $21^{\circ}C$, and total fecundity was observed 58.5 at $24^{\circ}C$. According to the life table, the net reproduction rate was 47.5 at $24^{\circ}C$, and the intrinsic rate of increase and the finite rate of increase were 0.36 and 1.43, respectively, at $27^{\circ}C$. The doubling time was 1.95d at $27^{\circ}C$, and mean generation time was 7.43d at $30^{\circ}C$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.757-767
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• 1995

This experiment was done to determine the optimum concentration of IAA for root development in plants regenerated from the callus culture of barley embryos. Two concentrations of 2,4-D, 3ppm and 5ppm selected as an optimum among five different concentrations in the previous experiment were used for callus induction and proliferation in this experiment. For callus induction, 3ppm of 2,4-D produced 35.6% in immature embryos and 4.4% in mature embryos, while 5ppm gave 33.8% in immature and 5.6% in mature embryos. Out of 320 immature embryos cultured, 111 embryos were induced to calli and 684 plants were produced from them, while only 16 embryos were induced to calli from 320 mature embryos and 92 plants were restored. The rates of callusing and plant regeneration were 34.7%, 214% in immature embryos and 5.0%, 28.7% in mature embryos, respectively. The average root lengths and root numbers of plants restored from callus at five different IAA concentrations of 0ppm, Ippm, 5ppm, l0ppm and 30ppm were 7.9mm, 3.6; 18.4mm, 5.2; 16.1mm, 3.9; 8.5mm, 3.5 and 6.4mm, 3.4, while plants directly obtained from mature embryos were 14.8mm, 4.9; 4.9mm, 3.6; 4.3mm, 3.1; 3.6mm, 2.6 and 3.2mm, 2.1, respectively. Therefore, 1ppm gave the best result for the root. promotion in callus, whle 0ppm, a control, gave the largest root developmemt in embryos. High concentration of lAA(30ppm) in callus and any exogeneous supplement of lAA in embryos negatively affected to the root lengths and root numbers. Genotypic effect was also observed in given four varieties, Bruce, Klages, Olbori and Albori. For chromosome doubling, when 0.1% colchicine was applied on 428 plants under three different conditions such as air circulation, temperatures and growth stages, 319 plants of doubled haploids were obtained so that the rate was 74.5%

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.381-387
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• 1997

Cancer tissues are characterized by increased glucose uptake. $^{18}F$-fluorodeoxyglucose(FDG), a glucose analogue is used for the diagnosis of cancer in PET studies. This study was aimed to compare the glucose uptake and glucose transporter 1(GLUT1) expression in various human colon cancer cells. We measured FDG uptake by cell retention study and expression of GLUT1 using Western blotting. Human colon cancer cells, SNU-C2A, SNU-C4 and SNU-C5, were used. The cells were incubated with $1{\mu}Ci/ml$ of FDG in HEPES-buffered saline for one hour. The FDG uptake of SNU-C2A, SNU-C4 and SNU-C5 were $16.8{\pm}1.36,\;12.3{\pm}5.55$ and $61.0{\pm}2.17cpm/{\mu}g$ of protein, respectively. Dose-response and time-course studies represent that FDG uptake of cancer cells were dose dependent and time dependent. The rate of FDG uptake of SNU-C2A, SNU-C4 and SNU-C5 were $0.29{\pm}0.03,\;0.21{\pm}0.09$ and $1.07{\pm}0.07cpm/min/{\mu}g$ of protein, respectively. Western blot analysis showed that the GLUT1 expression of SNU-C5 was significantly higher than those of SNU-C2A and SNU-C4. These results represent that FDG uptake into human colon cancer cells are different from each other. In addition, FDG uptake and expression of GLUT1 are closely related in human colon cancer cells.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.568-578
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• 2019

The nymphal development of the potato aphid, Macrosiphum euphorbiae (Thomas), was studied at seven constant temperatures (12.5, 15.0, 17.5, 20.0, 22.5, 25.0, and 27.5±1℃), 65±5% relative humidity (RH), and 16:8 h light/dark photoperiods. The developmental investigation of M. euphorbiae was separated into two steps, the 1^st through 2^nd and the 3^rd through 4^th stages. The mortality was under 10% at six temperatures. However, it was 53.0% at 27.5℃. The developmental time of the entire nymph stage was 15.5 days at 15.0℃, 6.7 days at 25.0℃, and 9.7 days at 27.5℃. In the immature stage, the lower threshold temperature of the larvae was 2.6℃ and the thermal constant was 144.5 DD. In our analysis of the temperature-development experiment, the Logan-6 model equation was most appropriate for the non-linear regression models (r²=0.99). When the distribution completion model of each development stage of M. euphorbiae larvae was applied to the 2-parameter and 3-parameter Weibull functions, each of the model's goodness of fit was very similar (r²=0.92 and 0.93, respectively). The adult longevity decreased as the temperature increased but the total fecundity of the females at each temperature was highest at 20℃. The life table parameters were calculated using the whole lifespan periods of M. euphorbiae at the above six temperatures. The net reproduction rate (R₀) was highest at 20.0℃(63.2). The intrinsic rate of increase (r_m) was highest at 25℃(1.393). The finite rate of doubling time (D_t) was the shortest at 25.0℃(2.091). The finite rate of increase (λ) was also the highest at 25.0℃(1.393). The mean generation time(T) was the shortest at 25.0℃(9.929).

• Journal of Life Science
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• v.28 no.10
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• pp.1201-1211
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• 2018

The study compared the anti-aging, anti-adipogenesis, and anti-tumor effects of epigallocatechin-3- gallate (EGCG) in various cancer cell lines (SNU-601, MKN74, AGS, MCF-7, U87-MG, and A-549) and normal cell lines (MRC-5 fibroblasts, dental tissue-derived mesenchymal stem cells [DSC], and 3T3-L1 pro-adipocytes). Half inhibitory concentration ($IC_{50}$) values were significantly (p<0.05) higher in normal cell lines (~50 uM), when compared to that in cancer cell lines (~10 uM). For anti-aging effects, MRC-5 and DSC were exposed to 10 uM EGCG for up to five passages that did not display any growth arrest. Population doubling time and senescence-related ${\beta}-galactosidase$ ($SA-{\beta}-gal$) activity in treated cells were similar to untreated cells. For anti-adipogenic effects, mouse 3T3-L1 pre-adipocytes were induced to adipocytes in an adipogenic differentiation medium containing 10 uM EGCG, but adipogenesis in 3T3-L1 cells was not inhibited by EGCG treatment. For anti-tumor effects, the cancer cell lines were treated with 10 uM EGCG. PDT was significantly (p<0.05) increased in EGCG-treated SNU-601, AGS, MCF-7, and U87-MG cancer cell lines, except in MKN74 and A-549. The level of telomerase activity and cell migration capacity were significantly (p<0.05) reduced, while $SA-{\beta}-gal$ activity was highly up-regulated in EGCG treated-cancer cell lines, when compared to that in untreated cancer cell lines. Our results have demonstrated that EGCG treatment induces anti-tumor effects more efficiently as noted by decreased cell proliferation, cell migration, telomerase activity, and increased $SA-{\beta}-gal$ activity than inducing anti-aging and anti-adipogenesis. Therefore, EGCG at a specific concentration can be considered for a potential anti-tumor drug.

• Korean journal of applied entomology
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• v.47 no.2
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• pp.163-168
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• 2008

Temperature dependent development of Tetranychus. urticae Koch was studied on the leaf of eggplant at 17, 22, 27, 32 and $37^{\circ}C$. T. urticae showed a minimum mortality at $27^{\circ}C$ and it increased at higher or lower temperatures than $27^{\circ}C$. The hatchability was low at 17 and $37^{\circ}C$. The duration of development decreased with increasing temperatures i.e., 5.3d at $37^{\circ}C$ and 25.8d at $17^{\circ}C$. Linear regression analysis of temperature vs. rate of development yielded the higher $r^2{\geq}0.88$ resulting in a good fit of the estimated line in the range of $17{\sim}37^{\circ}C$. Developmental zero temperature was $12.5^{\circ}C$ for the entire immature stage of female and $12.8^{\circ}C$ for that of male. Thermal constants were 80.5 and 74.7 degree days for those of female and male, respectively. Adult life span and oviposition period decreased with increasing temperatures. The number of eggs laid per female peaked at 141.0 eggs at $27^{\circ}C$, while that was a minimum 78.0 eggs at $37^{\circ}C$. Rate of hatchability, ratio of female, and $R_o$ were increased up to $27^{\circ}C$, and than declined thereafter. Intrinsic rate of natural increase (Rm) increased with rising temperatures and showed a maximum 0.5652 at $37^{\circ}C$. Also, ${\lambda}$ increased with increasing temperature. Doubling time (Dt) and generation time (T) decreased with increasing temperature.

• Korean journal of applied entomology
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• v.56 no.4
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• pp.387-394
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• 2017

Temperature-dependent oviposition model and life table parameters of Paromius exiguus (Distant), the causal agent of 'pecky' rice grain were examined at eight constant temperatures (17.5, 20, 22.5, 25, 27.5, 30, 32.5, and $35{\pm}^{\circ}C$) and a photoperiod of 14:10 (L:D) h. Unit functions of the oviposition model were developed and life table parameters were estimated. The longevity of P. exiguus adults decreased with increasing temperature (123.8 days at $17.5^{\circ}C$ and 23.6 days at $32.5^{\circ}C$). Total fecundity was highest at $30^{\circ}C$ (585.2 eggs/female) and lowest at $17.5^{\circ}C$ (21.5 eggs/female). In order to develop a temperature-dependent oviposition model, adult aging-rate, temperature-dependent fecundity, age-specific survival rate, and age-specific cumulative oviposition rate equations were estimated. All unit equations ($r^2=0.92{\sim}0.98$) except for the temperature-dependent fecundity equation ($r^2=0.83{\sim}0.85$), described oviposition characteristics of P. exiguus adequately. Life table parameters of P. exiguus were estimated at various constant temperatures. Net reproduction rate ($R_0$) was highest at $30^{\circ}C$ (118.21). Mean generation time (T) was shortest at $32.5^{\circ}C$ (32.99 days) and doubling time (Dt) was shortest at $30^{\circ}C$ (5.69 days). The highest values of intrinsic rate of increase ($r_m$) and finite rate of increase (${\lambda}$) were 0.122 and 1.129 at $30^{\circ}C$, respectively.