• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.103-103
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• 2002

This study was conducted to investigate cryopreservation of pearl oyster, Pinctada fucata martensii larvae. Four cooling rates (-0.25, -0.5, -0.75 and -1.0$^{\circ}C$/min.) were used to examine a proper cooling rate during cryopreservation of trochophores before seeding temperature (-12$^{\circ}C$). Seven developmental stages (early and late trochophores, early and late D-shaped larvae and early, middle and late umbo stage larvae) and different sugars (fructose, glucose and sucrose) were used to investigate optimal larval stage and effective sugar in cryopreservation of larvae. The survival rates of frozen-thawed trochophores increased at cooling rate of -1.0$^{\circ}C$/min. As larval developing, survival rate of frozen-thawed larvae increased, except umbo stage larvae, and especially late D-shaped larvae highly survived as 91%. Addition of sugar revealed positive effect on cryopreservation in this experiment and 0.2 M glucose and sucrose mixed with 2.0 M dimethyl sulfoxide significantly enhanced survival rate of larvae (P<0.05). The results of our study indicate that desirable cooling rate, developmental stages of larvae and effective sugar far cryopreservation of pearl oyster, P. fucata martensii larvae are -1$^{\circ}C$/min, late D-shaped larvae and 0.2 M glucose and sucrose, respectively.

• The Korean Journal of Ceramics
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• 제5권3호
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• pp.270-277
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• 1999

The ballistic capability of an alumina-rich oxide armor ceramic against a shaped jet was characterized as a function of penetration depth in a layered target structure. The penetration resistance of the ceramic, based upon the determination of penetration velocity, was not equally realized throughout the depth of penetration. It was abnormally low at an early stage of penetration, followed by a sudden increase to reach ~16GPa thereafter. There was no apparent change in such a profile with respect to the lateral size of the specimen. Based upon 2-D flash x-ray radiography and 3-D Hull code simulation, the feasibility of forming a pressure-induced predamnaged zone in front of the jet tip was speculated to foster an increased penetration velocity in the initial stage penetration, resulting in the diminished penetration resistance. The disappearance of such a predamaged zone with penetration was interpreted to restore the resistance of the ceramic in the later penetration stage.

• Fisheries and Aquatic Sciences
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• 제18권4호
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• pp.417-420
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• 2015

We investigated the relationship between viability and IGF-1 receptor (IGF-1R) activity in D-shaped and umbo larvae of the surf clam Spisula sachalinensis after treatment with vitrification solution (VS) or freezing. In a toxicity assay, VS1, containing 5 M dimethyl sulfoxide (DMSO), was very harmful to D-shaped and umbo larvae. However, VS2, containing 5 M ethylene glycol (EG), was not harmful to either larval stage. Although VS2 had a promising toxicity test outcome, none of the larvae survived vitrification. After immersion into VSs and freezing, IGF-1R ${\beta}$-subunits were detected in all larvae; however, tyrosine phosphorylation of intracellular ${\beta}$-subunits was detected only in the control and live groups. These results suggest that activation of IGF-1R may influence surf clam larvae viability.

• 한국발생생물학회지:발생과생식
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• 제17권4호
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• pp.337-343
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• 2013

Post-thawed larval rearing in Pacific oyster Crassostrea gigas was performed to investigate the survival rate with time course in three kinds of larvae cryopreserved. The highest survival rate and larval activity index (LAI) of post-thawed larvae were obtained from the permeation in 0.2 M sucrose and 2.0 M ethylene glycol (EG) at $-1^{\circ}C/min$ in freezing speed showing the survival rates just after thawing of 63.8% in trochophore, 84.1% in D-shaped veliger and 56.3% in early umbo veliger. In post-thawed larval rearing with food supply, the larvae lasted their lives until 24 hours in trochophore, 75 hours in D-shaped veliger and 57 hours in early umbo veliger. The results suggested that each larval stage post-thawed revealed no more further development to subsequent respective stage.

• 한국양식학회지
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• 제13권2호
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• pp.119-128
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• 2000

진주담치(Mytilus edulis), 홍합(Mytilus coruscus), 참굴(Crassostrea gigas) 및 진주조개(Pinctata fucata martensii)를 인위적인 방란 방정을 유도하여 이들의 수정란과 부유유생을 사육하여 난 발생, 유생의 성장 및 형태를 비교한 결과는 다음과 같다. 수정란의 크기는 진주담치와 홍합이 각각 65.1 ${\mu}m$, 70.3 ${\mu}m$로 비슷한 크기를 보였고, 참굴과 진주조개는 각각 52.3 ${\mu}m$, 45.3 ${\mu}m$로 비슷한 크기를 보였다. 수정란에서 D형 유생으로 되는 데 소요되는 시간은 진주담치와 참담치는 자연수온(17.0$\pm$1$^{\circ}C$)에서 각각 47시간55분, 45시간 55분이 소요되었고, 참굴과 진주조개는 수온 21.$0^{\circ}C$와 26.$0^{\circ}C$에서 각각 23시간 55분과 22시간이 소요되었다. 진주담치, 홍합, 참굴, 진주조개가 초기 D형 유생에서 부착기 유생으로 성장하는 데는 각각의 수온에서 각각 20일, 27일, 22일, 및 21일이 소요되었고 이때의 평균 각장의 크기는 각각 194.1 ${\mu}m$, 233.6 ${\mu}m$, 274.9 ${\mu}m$, 190.9 ${\mu}m$ 였다. 초기 D형 유생에서 초기 부착기 유생까지 각장(L)과 각고(H)의 상관관계는 높으며, 각장에 따른 각고/각장의 비율(H/L)은 진주담치: H/L : 0.002L+0.5334 (($R^2$ = 0.957), 홍합: H/L : 0.001L+0.603 ($R^2$ : 0.944), 참굴: H/L =0.001L+0.871 (($R^2$=0.550) 및 진주조개: H/L =0.001L+0.791 (($R^2$ = 0.700)로 나타났다

• 한국패류학회지
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• 제1권1호
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• pp.5-12
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• 1985

The maturity of gonads, early development of the fertilized egg, spawning period, and morphogenesis of larvae in Limnoperua fortunei were studied from October, 1981 to November, 1982 as on attempt to identify its life cycle. 1) Active motility of its sperm was observed at late May, and matured egg could be found at late June. 2) It was estimated that the spawning was occured from late August. This species was belong to the short-term breeder because it finished its spawning within 20 days. 3) It has free-living trochophore and D-shaped larva stage. The shell lengths of early, middle, and D-larval stage were $140.0{\mu}m$, $167.6{\mu}m$ and $210.0{\mu}m$, respectively. The shell heigths of each stage were $97.3{\mu}m$, $137.6{\mu}m$ and $178.2{\mu}m$, respectively.

• 한국해양학회지
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• 제23권2호
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• pp.70-75
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• 1988

피조개(Anadara broughtonii)의 효율적(效率的)인 종묘생산기술개발(種苗生産技術開發)을 목적(目的)으로 1974년(年) 7월(月)부터 10월(月)까지 진해만내(鎭海灣內)의 가조도 앞바다에서 부유유생(浮游幼生)의 출현시기(出現時期)와 각(各) 유생단계별(幼生段階別) 생존율(生存率)을 조사(調査)하였다. 조사기간중(調査期間中) 크기가 약(約) $94.3{\times}72.7{\mu}m$인 D형유생(型幼生)은 8월(月) 25일(日), 8월(月) 31일(日) 및 9월(月) 9일(日)에 각각(各各) 가장 많은 개체가 출현(出現)하였으며, $141.6{\times}108.4{\mu}m$인 umbo형유생(型幼生)은 9월(月) 6일(日), 9월(月) 12일(日) 및 9월(月) 20일(日)에, $269.3{\times}221.7{\mu}m$의 성숙유생(成熟幼生)은 9월(月) 20일(日), 9월(月) 25일(日) 및 10월(月) 5일(日)에 각각(各各) 출현개체수(出現個體數)가 가장 많았다. D형유생(型幼生)에서 umbo형유생(型幼生)으로 되는데는 약(約) 11~12일(日) 걸렸으며, 일간생존율(日間生存率)은 0.93, 생존개체수(生存個體數)의 백분비(百分比)는 45%였다. umbo형유생(型幼生)에서 성숙유생(成熟幼生)으로 되는데는 약(約) l3~15일 걸렸으며 일간생존율(日間生存率)은 0.93, 생존개체수(生存個體數)의 백분비(百分比)는 36%였다. D형유생(型幼生)의 발생(發生)에서 채묘(採苗)의 대상(對象)이 되는 성숙유생(成熟幼生)으로 되는데는 25~26일(日)이 걸렸으며 이 기간중(期間中) 생존개체(生存個體)의 백분비(百分比)는 16%였다.

• 한국양식학회지
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• 제17권2호
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• pp.97-102
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• 2004

흔한가리비, Chiamys nobilis의 산란유발 및 종묘생산을 위한 생물학적 기초자료를 얻고자 자극방법별 효과와 난 발생에 미치는 수온의 영향에 대하여 조사하였다. 산란유발방법으로는 햇빛노출자극방법이 자극 후 40분 이내 100%의 반응을 보여 반응시간이 가장 빨랐고, 그 외 자외선 조가 해수 자극방법에서도 70분 이내 100%의 반응으로 양호한 결과를 나타냈다. 발생 가능수온은 15∼3$0^{\circ}C$로 나타났다. 또한 초기 D상 유생에 도달하는 시간은 15, 20, 25 및 3$0^{\circ}C$에서 각각 63.5, 31.5, 18.5및 17.0시간이 소요되었다. 수온(WT: $^{\circ}C$)과 각 발생 단계별 소요시간(t: time)의 관계식은 다음과 같다. 2세포기: 1/t=0.0606WT-0.6194 ($r^2$=0.9791) 8세포기: 1/t=0.0304WT-0.3453 ($r^2$=0.9941) 상실기: 1/t=(1.0100WT-0.1049 ($r^2$=0.9663) 담륜자기: 1/t=0.0058WT-0.0618 ($r^2$=0.9848) D상유생: 1/t=0.0030WT-0.0282 ($r^2$=0.9731) 이들 관계식을 기초로 한 흔한가리비의 초기발생에 있어서 난 발생이 정지하는 생물학적 영도(Biological minimum temperature)는 평균 10.44$^{\circ}C$였고, 수온별 발생 시 D상까지의 생존율은 $25^{\circ}C$에서 가장 높았다.

• Journal of Plant Biotechnology
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• 제31권3호
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• pp.219-223
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• 2004

두릅나무의 엽병을 1.0 mg/L 2,4-D가 포함된 MS 고체배지에서 배발생캘러스를 유도하였다. 배발생세포와 배발생세포괴는 1.0 mg/L 2.4-D가 포함된 MS 액체배지에서 배발생캘러스를 2주간 현탁배양하여 대량으로 얻었다. 그물망을 통과한 배발생세포는 1.0 mg/L 2.4-D가 포함된 MS 액체배지에서 배양하면 배발생능이 소실되지 않고 지속적으로 유지 및 증식시킬 수 있었다. 그물망을 통과하지 못한 배발생세포괴를 식물생장조절물질이 첨가되지 않은 1/2 MS 액체배지에 옮겨 2주간 배양하면 구상형의 체세포배로 발달하였다. 구상형의 체세포배는 5 L의 bioreactor를 이용하여 배양하면 심장형, 어뢰형, 자엽형의 배와 유식물체로 발달하였다. Bioreactor 배양을 통해 두릅나무의 체세포배를 효과적으로 대량증식 시킬 수 있었다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제2권4호
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• pp.259-267
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• 2002

We present a novel 3D fabrication method with single X-ray process utilizing an X-ray mask in which a micro-actuator is integrated. An X-ray absorber is electroplated on the shuttle mass driven by the integrated micro-actuator during deep X-ray exposures. 3D microstructures are revealed by development kinetics and modulated in-depth dose distribution in resist, usually PMMA. Fabrication of X-ray masks with integrated electrothermal xy-stage and electrostatic actuator is presented along with discussions on PMMA development characteristics. Both devices use $20-\mu\textrm{m}$-thick overhanging single crystal Si as a structural material and fabricated using deep reactive ion etching of silicon-on-insulator wafer, phosphorous diffusion, gold electroplating, and bulk micromachining process. In electrostatic devices, $10-\mu\textrm{m}-thick$ gold absorber on $1mm{\times}1mm$ Si shuttle mass is supported by $10-\mu\textrm{m}-wide$, 1-mm-long suspension beams and oscillated by comb electrodes during X-ray exposures. In electrothermal devices, gold absorber on 1.42 mm diameter shuttle mass is oscillated in x and y directions sequentially by thermal expansion caused by joule heating of the corresponding bent beam actuators. The fundamental frequency and amplitude of the electrostatic devices are around 3.6 kHz and $20\mu\textrm{m}$, respectively, for a dc bias of 100 V and an ac bias of 20 VP-P (peak-peak). Displacements in x and y directions of the electrothermal devices are both around $20{\;}\mu\textrm{m}$at 742 mW input power. S-shaped and conical shaped PMMA microstructures are demonstrated through X-ray experiments with the fabricated devices.