• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.25-27
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• 2014

황천 운항 중인 선박은 파도에 의한 과도한 운동과 그로 인한 슬래밍, 프로펠러노출, 갑판침수와 같은 현상으로 구조, 화물, 인명에 위험을 초래할 수 있다. 이 때문에 황천 시 선박은 안전 운항을 위하여 속도와 코스를 신중히 결정할 필요가 있다. 선박 운동 모니터링 시스템은 해상환경이 선박에 미치는 다양한 위험 상황을 사전에 예측하고 피할 수 있도록 의사 결정을 지원하며, 현재 선박의 운동상태와 구조적 안정성을 지속적으로 모니터링 함으로써 선박, 선원, 화물의 안전을 지원할 수 있도록 개발되었다. 본 시스템은 주파수 영역에서 New strip 방법에 기초하여 운동 응답과 수직 굽힘 모멘트를 계산하며, 슬래밍, 프로펠러노출, 갑판침수를 예측한다. 또한 선박 운동과 선체구조응력을 실시간으로 모니터링하여 과도한 선체운동이나 선체구조피로 등의 위험 상황을 표시하고 선원의 작업성과 승선감의 지표인 MII (Motion induced interruption), MSI (Motion sickness incidence)를 제공한다.

• Development and Reproduction
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• v.23 no.1
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• pp.1-9
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• 2019

The ability of oocytes to undergo normal fertilization and embryo development is acquired during oocyte maturation which is transition from the germinal vesicle stage (GV), germinal vesicle breakdown (GVBD) to metaphase of meiosis II (MII). Part of this process includes redistribution of inositol 1, 4, 5-triphosphate receptor (IP3R), a predominant $Ca^{2+}$ channel on the endoplasmic reticulum membrane. Type 1 IP3R (IP3R1) is expressed in mouse oocytes dominantly. At GV stage, IP3R1 are arranged as a network throughout the cytoplasm with minute accumulation around the nucleus. At MII stage, IP3R1 diffuses to the entire cytoplasm in a more reticular manner, and obvious clusters of IP3R1 are observed at the cortex of the egg. This structural reorganization provides acquisition of $[Ca^{2+}]_i$ oscillatory activity during fertilization. In this review, general properties of IP3R1 in somatic cells and mammalian oocyte are introduced.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1632-1634
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• 2010

고성능 재구성형 어레이 아키텍처는 애플리케이션에 내재된 병렬성을 충분히 활용하도록 풍부한 하드웨어 리소스로 구성되어 있다. 이러한 하드웨어 리소스는 소프트웨어 파이프라이닝 기반 코드할당 기법을 통하여 사용된다. 이러한 코드할당 기법은 기존의 소프트웨어 파이프라이닝 기법에 FPGA 에서의 라우팅 & 위치선정기법이 연결된 형식으로 구성된다. 이러한 기존의 연구들은 데이터 흐름 (data flow)을 단순한 형태로 가정하여 개발되었다. 따라서 루프 코드 펼침 (loop unrolling)에 따라서 발생되는 데이터 복사에 의한 흐름 (copy flow)은 코드 매핑할 때 고려하지 않기 때문에 소프트웨어 파이프라이닝 적용시 네트웍 리소스의 중복사용으로 인한 데이터 충돌문제(data congestion)로 Minimum Initiation Interval (MII)증가에 따르는 성능 저하가 발생할 수 있다. 본 연구에서는 다양한 데이터 복사 흐름까지 고려하도록 데이터 의존도 그래프 (Data Dependence Graph, DDG)를 확장하여 스케쥴링 단계에서 데이터 충돌 지연에 의한 MII 증가를 방지하여 최적의 시스템 성능을 얻도록 코드 할당 기법을 개발하였다.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.96-96
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• 2003

Nek2 (NIMA-related protein) is a mammalian cell cycle-regulated kinase that involves in chromosome condensation and centrosome regulation and NuMA (nuclear mitotic apparatus protein) is involved in spindle assembly during a cell cycle. The cellular distribution and organization of the centrosomal components is completely unknown during fertilization and embryonic development. We examined distribution of two well-known centrosomal proteins, Nek2 and NuMA in mouse gametes and embryos to get an insight in the reorganization of centrosomal proteins during germ cell development and early fertilization. Spermatogenic cells, gametes, and embryos were analyzed with anti-Nek2 or -NuMA antibodies by immunological assay, RT-PCR, and overexpression through gene transfection. Mitotically or meiotically active spermatogenic cells were intensively stained with these antibodies in both centrosomes and cytoplasm, whereas the oocytes showed different staining patterns depending on the meiotic stages. During maturation, GV, GVBD, and MI stage were clearly stained with NuMA antibody in the nucleus or cytoplasm at MII. Also, Nek2 was detectable in cytoplasm as scattered spots or chromosome associated at MII. In early developmental embryo, NuMA was detected in nucleus of each blastomere, while Nek2 was detected in cytoplasm. In contrast to previously reported results, Nek2 and NuMA were detected in both decondensing head, and the centriole of demembranated and decondensed sperm or whole body of trypsin-treated sperm for Nek2. During meiotic progress in oocytes, transcripts levels were the highest in MI stage and then downregulated in MII. Also, it shows dramatically change in early developmental embryos, firstly, it was increased until 4 cell stage and reduced in 8 cell stage, and finally, transcript levels were upregulated until blastoscyst. This finding suggests that cnetrosomal component may play an important role in reorganizing of functional centrosome during fertilization process and subsequent development.

• Development and Reproduction
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• v.13 no.3
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• pp.145-153
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• 2009

Previously, we obtained the list of genes differentially expressed between GV and MII oocytes. Out of the list, we focused on functional analysis of Zap70 in the present study, because it has been known to be expressed only in immune cells. This is the first report about the expression and its function of Zap70 in the oocytes. Synthetic 475 bp Zap70 dsRNA was microinjected into the GV oocytes, and the oocytes were cultured in vitro. In addition to maturation rates, meiotic spindle and chromosome rearrangements, and changes in expression levels of transcripts of three kinases, Erk1/2, JNK, and p38, were determined. Zap70 is highly expressed in immature GV oocytes, and gradually decreased as oocyte matured. When dsRNA of Zap70 was injected into the GV oocytes, Zap70 mRNA specifically and completely decreased by 2 hr and its protein expression also decreased significantly. Absence of Zap70 resulted in maturation inhibition at meiosis I (57%) with abnormalities in meiotic spindle formation and chromosome rearrangement. Concurrently, mRNA expression of Erk2, JNK, and p38, were affected by Zap70 RNAi. Therefore, we concluded that Zap70 is involved in MI-MII transition by affecting expression of MAP kinases.

• Clinical and Experimental Reproductive Medicine
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• v.49 no.2
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• pp.135-141
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• 2022

Objective: This study investigated the impact of two stimulation protocols using highly purified human menopausal gonadotropin (HP-hMG) on the endocrine profile, follicular fluid soluble Fas levels, and outcomes of intracytoplasmic sperm injection (ICSI) cycles. Methods: This prospective clinical trial included 100 normal-responder women undergoing ovarian stimulation for ICSI; 55 patients received concomitant follicle-stimulating hormone (FSH) plus HP-hMG from the start of stimulation, while 45 patients received FSH followed by HP-hMG during mid/late follicular stimulation. The primary outcome was the number of top-quality embryos. The secondary outcomes were the number and percentage of metaphase II (MII) oocytes and the clinical pregnancy rate. Results: The number of MII oocytes was significantly higher in the concomitant protocol (median, 13.0; interquartile range [IQR], 8.5-18.0 vs. 9.0 [8.0-13.0] in the consecutive protocol; p=0.009); however, the percentage of MII oocytes and the fertilization rate were significantly higher in the consecutive protocol (median, 90.91; IQR, 80.0-100.0 vs. 83.33 [75.0-93.8]; p=0.034 and median, 86.67; IQR, 76.9-100.0 vs. 77.78 [66.7-89.9]; p=0.028, respectively). No significant between-group differences were found in top-quality embryos (p=0.693) or the clinical pregnancy rate (65.9% vs. 61.8% in the consecutive vs. concomitant protocol, respectively). The median follicular fluid soluble Fas antigen level was significantly higher in the concomitant protocol (9,731.0 pg/mL; IQR, 6,004.5-10,807.6 vs. 6,350.2 pg/mL; IQR, 4,382.4-9,418.4; p=0.021). Conclusion: Personalized controlled ovarian stimulation using HP-hMG during the late follicular phase led to a significantly lower response, but did not affect the quality of ICSI.

• Clinical and Experimental Reproductive Medicine
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• v.43 no.1
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• pp.9-14
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• 2016

Objective: Autophagy contributes to the clearance and recycling of macromolecules and organelles in response to stress. We previously reported that vitrified mouse oocytes show acute increases in autophagy during warming. Herein, we investigate the potential role of Atg7 in oocyte vitrification by using an oocyte-specific deletion model of the Atg7 gene, a crucial upstream gene in the autophagic pathway. Methods: Oocyte-specific Atg7 deficient mice were generated by crossing Atg7 floxed mice and Zp3-Cre transgenic mice. The oocytes were vitrified-warmed and then subjected to in vitro fertilization and development. The rates of survival, fertilization, and development were assessed in the Atg7 deficient oocytes in comparison with the wildtype oocytes. Light chain 3 (LC3) immunofluorescence staining was performed to determine whether this method effectively evaluates the autophagy status of oocytes. Results: The survival rate of vitrified-warmed $Atg7^{f/f}$;Zp3-Cre ($Atg7^{d/d}$) metaphase II (MII) oocytes was not significantly different from that of the wildtype ($Atg7^{f/f}$) oocytes. Fertilization and development in the $Atg7^{d/d}$ oocytes were significantly lower than the $Atg7^{f/f}$ oocytes, comparable to the $Atg5^{d/d}$ oocytes previously described. Notably, the developmental rate improved slightly in vitrified-warmed $Atg7^{d/d}$ MII oocytes when compared to fresh $Atg7^{d/d}$ oocytes. LC3 immunofluorescence staining showed that this method can be reliably used to assess autophagic activation in oocytes. Conclusion: We confirmed that the LC3-positive signal is nearly absent in $Atg7^{d/d}$ oocytes. While autophagy is induced during the warming process after vitrification of MII oocytes, the Atg7 gene is not essential for survival of vitrified-warmed oocytes. Thus, induction of autophagy during warming of vitrified MII oocytes seems to be a natural response to manage cold or other cellular stresses.

• Clinical and Experimental Reproductive Medicine
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• v.39 no.3
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• pp.107-113
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• 2012

Objective: To determine whether animal age impacts in vitro preantral follicle growth. Effects of hCG, stem cell factor (SCF), and/or insulin-like growth factor (IGF) supplementation in growth medium were also investigated. Methods: Intact preantral follicles were mechanically isolated from fresh ovaries of BDF1 mice and cultured in growth medium for 9 to 11 days. Surviving follicles with antrum formation were transferred to maturation medium for 14 to 18 hours. Follicle survival, antrum formation, and retrieval of metaphase II (MII) oocytes were compared among three age categories (4-5, 7-8, and 10-11 week-old). By using 7- to 8-week-old mice, preantral follicles were cultured in growth medium supplemented with hCG (0, 5, or 10 mIU/mL), SCF (50 ng/mL), IGF-1 (50 ng/mL), and SCF+IGF-1. Results: Seven- to eight-week-old mice showed a higher follicle survival and antrum formation and produced more MII oocytes compared to other groups. In the 7- to 8-week-old mice, supplementation of 5 mIU/mL hCG significantly enhanced the antrum formation but the percentage of MII oocytes was similar to that of the control. Supplementation of SCF+IGF-1 did not enhance follicle survival or antrum formation but the percentage of MII oocytes increased modestly (39.1%) than in the control (28.6%, p>0.05, statistically not significant). Conclusion: Seven- to eight-week-old mice showed better outcomes in growth of preantral follicles in vitro than 4- to 5- or 10- to 11-week-old mice. Supplementation of hCG enhanced antrum formation and supplementation of SCF+IGF-1 yielded more mature oocytes; hence, these should be considered in the growth of preantral follicles in vitro.

• 대한생식의학회:학술대회논문집
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• 2004.11a
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• pp.101.2-102
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• 2004

• Reproductive and Developmental Biology
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• v.34 no.1
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• pp.21-25
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• 2010

The purpose of this study was to investigate the effects of the collection time, co-culture and sperm penetration of canine oocytes on in vitro maturation and fertilization. The oocytes were cultured in TCM-199 media containing hormonal supplements (10% FCS, 10 IU/ml HCG, 10 IU/ml PMSG) at 5% $CO_2$, 95% air, $38^{\circ}C$. The in vitro maturation rate to MII stage of in vitro oocytes recovered from ovaries that collected at follicular, luteal and inactive phases of the reproductive phase for 44~72 hrs were 19.2%, 12.2%, and 6.0%, respectively. Follicular phases oocytes had a significantly higher in vitro maturation rate than oocytes collected at luteal and anestrus stage (p<0.05). The in vitro maturation rates to the MII stage of canine oocytes after 48 hrs of culture with glutathione, pyruvate, or glutathione + pyruvate were 12.5%, 10.7%, and 17.5%, respectively. This was higher than that in both alone or the combination of the two compared to the control group (19.0%). The sperm penetration rates of in vitro matured oocytes by fresh and frozen semen were 29/80 (36.3%) and 18/80 (22.5%), respectively. Although there are limited reports about canine oocytes co-culture and in vitro fertilization, our results on in vitro maturation is comparable to the results from other researches.