• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.411-414
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• 2005

It is reported that $\varepsilon$ (HCP) and $\gamma$ (FCC) phases of a Fe-17Mn alloy transform to $\alpha'$ phase, which has BCC structure, under a deformation condition. In this study, we investigated the effect of strain-induced-transformed $\alpha'$ phase on sliding wear of the Fe-17Mn alloy that originally had e and y phases. Wear tests of the materials were carried out using a pin-on-disk wear tester at various loads of 0.5N-50N under a constant sliding speed condition of 0.38m/s against glass $(83\%\;SiO_2)$ beads. The sliding distance and radius were loom and 9 mm, respectively. Wear rate of the Fe-17Mn alloy was calculated by dividing the weight loss, measured to the accuracy of $10^{-5}g$ by the measured specific gravity and sliding distance. Worn surface and wear debris of the specimens were examined using an SEM and XRD. During the wear, $\alpha'$ phase of BCC structure was formed by strain-induced transformation when the applied wear load exceeded critical values. The $\alpha'$ phase formed by the strain induced transformation increased the wear rate of the Fe-17Mn alloy.

• 한국발생생물학회지:발생과생식
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• 제28권2호
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• pp.55-65
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• 2024

In vertebrates, Fgf signaling is essential for the development of pharyngeal pouches, which controls facial skeletal development. Genetically, fgf3 and fgf8 are required for pouch formation in mice and zebrafish. However, loss-of-function phenotypes of fgf3 and fgf8 are milder than expected in mice and zebrafish, which suggests that an additional fgf gene(s) would be involved in pouch formation. Here, we analyzed the expression, regulation, and function of three fgfs, fgf4, fgf24, and fgf17, during pouch development in zebrafish. We find that they are expressed in the distinct regions of pharyngeal endoderm in pouch formation, with fgf4 and fgf17 also being expressed in the adjacent mesoderm, in addition to previously reported endodermal fgf3 and mesodermal fgf8 expression. The endodermal expression of fgf4, fgf24, and fgf17 and the mesodermal expression of fgf4 and fgf17 are positively regulated by Tbx1 but not by Fgf3, in pouch formation. Fgf8 is required to express the endodermal expression of fgf4 and fgf24. Interestingly, however, single mutant, all double mutant combinations, and triple mutant for fgf4, fgf24, and fgf17 do not show any defects in pouches and facial skeletons. Considering a high degree of genetic redundancy in the Fgf signaling components in craniofacial development in zebrafish, our result suggests that fgf4, fgf24, and fgf17 have a potential role for pouch formation, with a redundancy with other fgf gene(s).

• 한국발생생물학회지:발생과생식
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• 제19권4호
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• pp.243-252
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• 2015

The pregnancy and abortion process involves a complex mechanism with various immune cells present in the implantation sites and several hormones associated with pregnancy, such as leptin, ghrelin and nesfatin-1. However, the mechanism underlying spontaneous abortion by maternal T helper 17 (Th17) present in the implantation sites and nesfatin-1, which is of anorexigenic hormones, is not fully understood so far. Therefore, the purpose of this study was to examine the possible roles of Th17 cells present in the implantation sites and nesfatin-1 expressed in the uterus on spontaneous abortion using the $CBA/j{\times}DBA/2$ mouse model. Th17 transcription factor, ROR-${\gamma}t$ mRNA expression was significantly increased in the abortion sites compared with the implantation sites of abortion model mice on day 14.5 and 19.5 of pregnancy. In addition, the expression levels of IL-17A mRNA were significantly higher in abortion sites than in implantation sites on day 14.5 and 19.5. Moreover, the nesfatin-1/NUCB2 protein and mRNA levels were increased in abortion sites compared with levels in implantation sites of both normal pregnant and abortion model mice on day 14.5 of pregnancy. Interestingly, nesfatin-1/NUCB2 serum levels were not changed throughout the whole pregnancy in abortion model mice, but its serum level was dramatically increased on day 14.5, and then rapidly decreased on day 19.5 in normal pregnant mice. In this study, we showed for the first time the expression of nesfatin-1/NUCB2 mRNA and protein in implantation sites during pregnancy. The present results suggest that Th17 cells in the uterus may play an important role in the period of implantation and for maintenance of pregnancy. Furthermore, the present results suggest that Th17 cells in implantation sites may be a key regulator for maintenance of pregnancy and provides evidence that activation of these cells may be regulated by nesfatin-1/NUCB2. Further study is needed to elucidate the role of nesfatin-1 expressed in the uterus during pregnancy.

• 국제지역연구
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• 제22권2호
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• pp.189-209
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• 2018

본 연구의 목적은 개발협력의 국제적 연구동향을 파악하기 위해 국제개발협력 분야에서 저널 영향력 지수(impact factor)가 최상위인 World Development와 Journal of Development Studies에 언급된 SDGs의 17개 목표들 간의 연결 관계를 분석하는 것이다. SDGs의 17개 목표는 5개(사람, 지구, 파트너십, 평화, 번영) 범주로 구분되며, 이들은 서로 연결되어 있다. 본 연구에서는 SDGs 17개 목표 간의 연결망을 밝히기 위해 Atlas.ti 소프트웨어를 활용하여 논문 초록 내용분석을 시행했다. SDGs 수립 이후 World Development와 Journal of Development Studies에 발행된 730편의 학술지 초록을 분석한 결과는 다음 세 가지로 요약된다. 첫째, 젠더(gender)와 관련한 이슈들이 두 개의 학술지 모두에서 중요하게 다뤄지고 있었다. 특히 여성과 소득의 불평등, 여성의 건강문제, 교육과 관련된 주제들 간의 연결 관계가 높게 나타났다. 둘째, 두 개의 학술지에서 주로 분석된 국가는 중국과 인도이며, 특히 World Development의 경우 남남협력(south-south cooperation)을 집중적으로 다루었다. 셋째, World Development는 SDGs 11부터 SDGs 17까지의 사례 연구 중 개발도상국과 관련된 내용은 상대적으로 적은 반면 Journal of Development Studies에는 기후, 수자원 및 육지생태계 보호와 관련된 환경 이슈 연구가 거의 없음을 발견했다. 따라서 변혁적이고 포괄적인 개발 목표 달성과 분석을 위해 향후 각 목표의 연결망에 기반 한 보다 균형 있는 연구가 요청된다.

• 생명과학회지
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• 제23권10호
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• pp.1252-1259
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• 2013

인간 암세포의 생육에 미치는 혈전용해효소(BK-1)의 영향을 조사하기 위해, 세포증식, 생존력, 형태변화 및 apoptosis 유도 등을 포함한 여러 가지 생화학적 실험을 하였다. 그 결과, AGS 인간 위장 암세포 및 T24 인간 방광 암세포상에의 BK-17 처리는 그 암세포들의 생존력 및 생율을 농도의존적 방법으로 감소시켰다. 현미경 관찰은, BK-17 처리에 의한 항 생육 효과는 막 수축, 세포의 rounding up, apoptotic bodies와 같은 형태학적 변화를 나타내었다. 특히, RT-PCR과 Western blotting data는, BK-17 처리가 항 apoptosis Bcl-2 군들 특히 Bcl-2, and $Bcl-X_L$의 down-regulation 그리고 AGS 세포에서, apoptosis 촉진 매개체 Bax와 Bad의 up-regulation를 유도했다는 것을 보여주었다. BK-17에 의해 유도된 AGS 세포의 apoptosis는 caspase-3, caspase-8 그리고 caspase-9의 단백질가수분해 활성과 관련이 있었다. 이상의 결과를 볼 때, BK-17은 apoptotic cell death의 유도와 밀접한 관련이 있다는 것을 보여주고 있다.

• 대한임상약리학회:학술대회논문집
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• 대한임상약리학회 1995년도 정기총회 및 추계학술대회
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• pp.17-17
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• 1995

• Environmental Engineering Research
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• 제17권3호
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• pp.175-176
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• 2012

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1998년도 한국우주과학회보 제7권1호
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• pp.17.2-17
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• 1998

• 대한간호
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• 제17권6호통권98호
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• pp.15-17
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• 1978

• 대한치주과학회:학술대회논문집
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• 대한치주과학회 2008년도 춘계학술대회
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• pp.17-17
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• 2008