• 한국발생생물학회지:발생과생식
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• 제16권2호
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• pp.107-112
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• 2012

Early growth, the rate of yolk sac absorption, and nucleus size in liver parenchymal cells were correlated with the nutritional status of first feeding larval haddock, Melanogrammus aeglefinus. Larvae that successfully began exogenous feeding maintained high growth rates, delayed yolk sac resorption, and had larger hepatocyte nuclear sizes than starved larvae. At 10 days post hatch (DPH) the cumulative mortality in the starved larval haddock group was 100%. The area of the hepatocyte nuclei in starved larvae gradually decreased, reaching its lowest value by 9 DPH. Our results support the current practice of providing the first food supply at 3 DPH. Hepatocyte nuclear size can be used to assess larval haddock nutrition status, and may be a good criterion for assessing the success of transition from endogenous to exogenous feeding.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 1998년도 제4차 학술발표대회 및 정기총회
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• pp.43-44
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• 1998

Effect of somatic cell coculture on hatching of mouse blastocyst was examined. Mid-blastocysts were cocultured with granulosa cell primary culture or Sertoli cell line ($TM_{4}$) derived from mouse testis for 48 hr. Blastocysts cultured in medium (10% FBS) started to hatch more faster than cocultured embryos during 12 hr of coculture. After then blastocysts cocultured with somatic cell hatched faster than control. Degeneration of embryos was also greately reduced by coculture. This result suggested the potentiation of hatching as well as embryonic viability by coculture with somatic cell and Sertoli cell line can be used for embryo coculture.

• 오토저널
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• 제9권5호
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• pp.41-48
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• 1987

The aerodynamic critical phenomenon of notch-back type automobile-like bodies was investigated experimentally. The aerodynamic forces were measured for the various bodies of different back-light rake angle at R$_{e}$0.8*10$^{5}$ , 1.0*10$^{6}$ and 1.4*10$^{6}$ . Also, surface flow visualization was effected by the oil mixture. It was found that the critical phenomenon for the notch-back type bodies was milder than for the hatch-back type bodies; the drag vs. slant angle curve for the notch-back type bodies exhibiting local maximum was much smoother. Surface oil flow visualization revealed that the flow pattern associated with the critical phenomenon was characterized by the reattachment of the separated flow on the boot. The effect of the forebody on the critical phenomenon was seen to be negligible.e.

• Bulletin of the Korean Chemical Society
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• 제29권6호
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• pp.1179-1184
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• 2008

Commercial nanometer sized silver is widely used for its antibacterial effect; however, nanoparticles may also have ecotoxicological effects after being discharged into water. Nanometer sized silver can flow into aquatic environments, where it can exert a variety of physiologically effects in living organisms, including fish. The present study aimed to investigate the effect of nanometer sized silver on the development of zebrafish embryos, analyze the properties of commercial nanometer sized silver and define the toxicity relationship between embryogenesis and hatched flies. The commercial nanometer sized silver was analyzed in the $Ag^+$ ion form. The hatch rate decreased in the nano-silver exposed groups (10 and 20 ppt); furthermore, the hatched flies had an abnormal notochord, weak heart beat, damaged eyes and curved tail. The expression of the Sel N1 gene decreased in the nano-silver exposed groups, and the catalase activities of the exposed groups increased relative to those in the control group. Therefore, the $Ag^+$ ions in commercial nanometer sized silver could accumulate in aquatic environments and seriously damage the development of zebrafish embryos.

• 한국안전학회지
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• 제25권3호
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• pp.45-52
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• 2010

The purpose of this study is application to flame retardant powder coating(FRPC) material consisting of ammonium polyphosphate(APP) and magnesium hydroxide($Mg(OH)_2$) as a halogen free flame retardant into thermoplastic resin(LDPE-g-MAH). For improvement of adhesion, LDPE-g-MAH was synthesized from low density polyethylene(LDPE) and maleic anhydride(MAH). The mechanical properties as melt flow index, pencil hardness, cross-hatch adhesion and impact resistance of FRPC were measured. Also, the limited oxygen index(LOI) values were measured 17.3vol%, 31.1vol% and 33.7vol% for LDPE-g-MAH, FRPC-3(APP 15wt%, $Mg(OH)_2$ 15wt%) and FRPC-5(APP 30 wt%), respectively. The thermo gravimetry/differential thermal analysis(TG/DTA) of FPRC-3 was observed endothermic peak at $340^{\circ}C$ and $450^{\circ}C$, it was confirmed predominant thermal stability though the wide temperature range by APP and $Mg(OH)_2$. It was showed V-0 grade for FRPC-3 and FRPC-4(APP 20wt%, $Mg(OH)_2$ 10wt%) that a char formation and drip suppressing effect, and combustion time reduced by UL94(vertical burning test). It was confirmed that flame retardancy was improved with the synergy effect because of char formation by APP and $Mg(OH)_2$.

• 한국수정란이식학회지
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• 제23권1호
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• pp.1-4
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• 2008

This study was performed to investigate the effect of laser-assisted hole in the zona pellucida (ZP) of frozen-thawed ICR mouse embryos on the process of hatching that is critical for expanded blastocysts to implant into endometrium, Vitrification medium, composed of ethylene glycol and sucrose supplemented with 7.5% (w/v) PVP, was used to freeze $2{\sim}4$ cell stage embryos recovered from oviducts of superovulated and mated female mice before storing them in $LN_2$. Right after thawing them, a laser beam was shot to make a hole in ZP followed by culturing in KSOM for $96{\sim}120\;hr$ and examining development to blastocyst and hatching every 12 hr. Laser-treated embryos showed significantly higher hatching rate compared to control (92.9% vs. 22.1%, p<0.05). From around Day 4, blastocysts developed from laser-treated embryos started hatching while the blastocysts of control group failed to hatch showing a lot of shrinkage. This study shows that a laser-assisted hole in ZP improves the hatching rate of blastocysts developed from frozen-thawed, in vitro cultured ICR mouse embryos.

• 생명과학회지
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• 제13권2호
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• pp.150-153
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• 2003

현재 각 종 작물에 큰 피해를 주고 있는 점박이 응애(Tetranychus urticne Koch)의 밀도를 줄이기 위해 새로 개발된 살충제를 각 처리농도별로 (0.5%, 1.0%, 1.5%) 응애가 접종된 콩잎 디스크에 살포하여 살충 효과를 검정하였으며, 대조구로서 증류수만을 살포한 콩잎 디스크와 비교하였다. 공시 살충제의 살충효과는 점박이 응애 성충의 암컷과 약충에는 탁월하였으나, 알에는 비교적 효과가 낮았다. 동일 처리 농도별 성충과 약충의 살충 초과를 비교하였을 때, 성충의 살충률이 약충의 살충률보다 높았다. 또한, 약제 처리구와 대조구 간의 알의 부화율에 있어서는 유의적인 차이가 없었다.

• International Journal of Industrial Entomology and Biomaterials
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• 제37권2호
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• pp.90-94
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• 2018

In the present study, we investigated the effects of temperature and photoperiod on oviposition of Protaetia brevitarsis. The effects of long- and short-day cycles on oviposition and egg hatching of P. brevitarsis were investigated at different temperatures. Three male-female pairs were confined to oviposition chambers maintained at $20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$, and $35^{\circ}C$, with 16L:8D and 8L:16D photoperiod. Oviposition was observed at all temperatures. The total number of eggs laid per female was between 46.8 and 110.8, and the optimal temperature for oviposition and fertility was between $20^{\circ}C$ and $30^{\circ}C$. Furthermore, it was difficult for the eggs to hatch at $35^{\circ}C$. Fewer eggs were laid under short photoperiod than under long photoperiod at all temperatures. Hatching success was 93.5% at $20^{\circ}C$, 90.9% at $25^{\circ}C$, 71.5% at $30^{\circ}C$ and 37.3% at $35^{\circ}C$ under long-day(16L:8D) condition and Temperature had a strong effect on the time to hatching. Neither oviposition nor subsequent egg hatching was influenced by photoperiod and temperature. The information obtained will be useful for mass rearing P. brevitarsis.

• 농약과학회지
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• 제6권4호
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• pp.257-263
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• 2002

본 연구는 국내에서 현재 시판되고 있는 살충제 12종에 대한 줄점팔랑나비 (Parnara guttata)의 발육 단계별 약제감수성 및 아치사농도가 암컷성충의 수명, 산란전기, 산란수, 그리고 차세대의 부화율 및 발육에 미치는 영향을 조사하였다. 알에 대해서는 fenitrothion과 fenthion, cartap hyochloride, imidacloprid, ethofenprox가 높은 활성을 나타내었다. 시험에 사용한 모든 약제는 $1{\sim}2$령 유충에 대해서 활성을 나타내었으며, 5령 유충에 높은 살충활성을 보인 약제는 fenitrothion, fenthion, ethofenprox, fipronil, methoxyfenozide, tebufenozide and Bt. var. kurstaki였다. $3{\sim}4$령기에 $LC_{40}$ 수준의 약제처리 후 생존한 유충으로부터 우화한 성충과 그 차세대에 대한 영향은 대부분의 약제에서 관찰되었다. Fenthion, tebufenozide, cartap hydrochloride, methoxyfenozide, ethofenprox, imidacloprid, apronil은 암컷성충의 수명을 단축시키는 것으로 조사되었다. BPMC, imidacloprid, ethofenprox, fipronil, methoxyfenozide는 암컷성충의 산란전기를 지연시키고 산란수를 감소시켰는데, ethofenprox가 처리된 경우는 전혀 산란을 하지 않았다. 알의 부화율은 fenitrothion을 제외한 모든 약제에서 감소하였으며, 그 중 imidacloprid와 fipronil의 경우 알은 전혀 부화하지 않았다. 또한, IGR제인 methoxyfenozide와 tebufenozide는 차세대 유충의 발육에도 영향을 주었다.

• 한국응용곤충학회지
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• 제49권2호
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• pp.129-137
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• 2010

전자빔 조사(30, 50, 70, 100 Gy)가 주요 농업해충(담배가루이, 복숭아혹진딧물, 배추좀나방, 점박이응애)의 발육과 생식에 미치는 영향을 조사하였다. 담배가루이, 배추좀나방, 점박이응애 알의 부화는 조사량이 많아질수록 억제되었으며, 특히 담배가루이와 점박이응애 알은 10 0Gy 조사량에서 부화가 100%억제되었다. 그러나 약충/유충, 번데기, 담배가루이, 배추좀나방, 점박이응애의 알에 조사했을 때 부화유충의 우화억제에 영향을 미쳤다. 그리고 70 Gy 조사량에서 담배가루이 우화성충은 산란을 하지 않았고, 100 Gy 조사량에서 배추좀나방 우화성충의 산란수가 감소하였다. 담배가루이, 배추좀나방, 복숭아혹진딧물, 점박이응애 약충/유충에 조사했을 때 70과 100 Gy 조사량에서 부화유충에 미치는 영향과 비슷하였다. 배추좀나방 번데기에 조사했을 때 100 Gy에서 산란수가 감소하였고, 산란한 알이 100% 부화하지 못했다. 담배가루이, 배추좀나방, 복숭아혹진딧물, 점박이응애의 성충에 조사했을 때 70, 100 Gy에서 산란수/산자수가 감소하였으며, 산란한 알의 부화억제에도 영향을 미쳤다. 특히 담배가루이 알은 부화가 100%억제되었다. 그러나, 4종의 주요 농업해충의 모든 발육태에 조사하였을 때 성충수명에는 영향이 없었다.