• 한국가축번식학회지
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• 제13권2호
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• pp.79-84
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• 1989

This study was carried out to investigate the effect of LH-RH and Gn-RH treatment in Holstein cows with ovarian quiescence and follicular cystic ovaries. The cows with ovarian quiescence and follicular cystic ovaries injected intramuscularly with 100$\mu\textrm{g}$, 200$\mu\textrm{g}$ and 400$\mu\textrm{g}$ of LH-RH and 200$\mu\textrm{g}$ and 400$\mu\textrm{g}$ of Gn-RH respectively. The cows was diagnosed by repeated rectal palpation. The plasma progesterone and estradiol-17$\beta$ concentrations were assayed by radioimmunoassay methods. The resutls of this study were summarized as follows : 1. Ovulations were induced after treatment of LH-RH and Gn-RH. The concentrations of progesterone reached small peak level at luteal phase and estradiol-17$\beta$ reached obvious peak level with the development and maturation of the follicle during the periods of degeneration of the corpus luteum, and normal ovarian cycle activity started subsequently. 2. The cows with ovarian quiescence and follicular cystic ovaries were induced ovulation at 38.9$\pm$5.3 hrs. after treatment of LH-RH in 66.7% cows and at 52.7$\pm$7.9 hrs after treatment of Gn-RH in 60.0% cows respectively. 3. The good ovarian responses were indicated in treatment with 200$\mu\textrm{g}$ to 400$\mu\textrm{g}$ of LH-RH than those treated with 100$\mu\textrm{g}$ in cows with ovarian quiescence, and did not show difference of ovarian responses between treatments with 200$\mu\textrm{g}$ to 400$\mu\textrm{g}$ of Gn-RH in cows with follicular cystic ovaries.

• BMB Reports
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• 제55권8호
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• pp.380-388
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• 2022

The B cell translocation gene 1 (BTG1) and BTG2 play a key role in a wide range of cellular activities including proliferation, apoptosis, and cell growth via modulating a variety of central biological steps such as transcription, post-transcriptional, and translation. BTG1 and BTG2 have been identified by genomic profiling of B-cell leukemia and diverse lymphoma types where both genes are commonly mutated, implying that they serve as tumor suppressors. Furthermore, a low expression level of BTG1 or BTG2 in solid tumors is frequently associated with malignant progression and poor treatment outcomes. As physiological aspects, BTG1 and BTG2 have been discovered to play a critical function in regulating quiescence in hematopoietic lineage such as Hematopoietic stem cells (HSCs) and naive and memory T cells, highlighting their novel role in maintaining the quiescent state. Taken together, emerging evidence from the recent studies suggests that BTG1 and BTG2 play a central anti-proliferative role in various tissues and cells, indicating their potential as targets for innovative therapeutics.

• BMB Reports
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• 제50권9호
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• pp.472-477
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• 2017

The transcription repressor Bach2 has been proposed as a regulator of T cell quiescence, but the underlying mechanism is not fully understood. Given the importance of interleukin-2 in T cell activation, we investigated whether Bach2 is a component of the network of factors that regulates interleukin-2 expression. In primary and transformed $CD4^+$ T cells, Bach2 overexpression counteracted T cell receptor/CD28- or PMA/ionomycin-driven induction of interleukin-2 expression, and silencing of Bach2 had the opposite effect. Luciferase and chromatin immunoprecipitation assays revealed that Bach2 binds to multiple Maf-recognition element-like sites on the interleukin-2 proximal promoter in a manner competitive with AP-1, and thereby represses AP-1-driven induction of interleukin-2 transcription. Thus, this study demonstrates that Bach2 is a direct repressor of the interleukin-2 gene in $CD4^+$ T cells during the immediate early phase of AP-driven activation, thereby playing an important role in the maintenance of immune quiescence in the steady state.

• 자원환경지질
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• 제13권1호
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• pp.51-63
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• 1980

한반도 주위의 새로운 구조력(neotectionics)을 이해하고, 지진 위험을 평가하기 위해서, 한반도와 그 인접지역의 지진활동을 시간적 및 공간적으로 조사 연구한다. 본 연구는 역사적문헌에서 얻은 기술적인 지진자료와 세계지진 관측망 (WWSSN)에서 얻은 기록등을 사용하여 수행되었다. 한반도의 지진 활동은 13 세기부터 17 세기까지에 가장활발하였다. 지진정지기 (seismic quiescence)는 18 세기에 들어와서 시작하여 약 200 년동안 계속되었다. 최근에와서 지진활동dms 다시 활발하다는 것이 발견되었다. 지진의 위험 분포와 지진회복주기 (return period) 는 축적규모진도수에 의한 통계학적 방법에 의해서 결정되었다. 최근 한반도에서 지진 위험지역은 반도의 서남부 및 서부지역에서 더욱 크다는 것이 발견되었다. Focal mechanism에 의한 일본해 부근의 지진잠재력(neotectonic stress)에 관해서 고찰하면, 옛날의 Paleotectonics의 주력은 지구의 crust의 확장설(expanding)에 의해서 큰 지배를 받았지만, 최근은 태평양 plate가 유라시아 대륙이나 필립핀 plate 밑으로 충돌하여 들어가는 subducting motion 에 큰 지배를 받고 있다는 것이 발견되었다.

• 한국자원식물학회지
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• 제15권2호
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• pp.89-95
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• 2002

자작나무 식물유전자원의 효과적인 장기보존 방안을 구명하기 위해 동결전처리 된 겨울철 동아를 건조처리에 의해 초저온보존 시험하여 다음과 같은 결과를 얻었다. 자작나무 동아는 내동성이 최고조에 달한 1월 20일경의 함수율이 42.43%로 가장 낮게 나타났다. 1월 20일에 채취한 동아를 10분간의 건조처리 와 5~-2$0^{\circ}C$까지 1분당 1$^{\circ}C$ 하강조건으로 완속동결 전처리하여 -196$^{\circ}C$의 액체질소에 초저온 보존한 경우의 세포생존율은 83.33%로 가장 이상적인 처리조건으로 조사되었다. 자작나무 동아의 시료조제는 동아에 약간의 목질부 조직을 붙여 초저온 보존하는 경우에 86.7%로 세포생존율이 높게 나타났다. 24시간 이상 액 체질소에 초저온 보존한 자작나무 동아는 40$\pm$5$^{\circ}C$의 온수 중에서 급속 해동하는 경우가 86.6%의 세포생존율을 비롯하여 60%의 식물체 재생율을 나타내어 본 실험에서 가장 효과가 좋은 것으로 조사되었다.

• BMB Reports
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• 제48권8호
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• pp.429-430
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• 2015

Angiogenesis is a complex process involving dynamic interaction of various cell to cell interactions. Endothelial cell interactions regulated by growth factors, inflammatory cytokines, or hemodynamic stress are critical for balancing vascular quiescence and activation. Yes-associated protein (YAP), an effector of Hippo signaling, is known to play significant roles in maintaining cellular homeostasis. However, its role in endothelial cells for angiogenic regulation remains relatively unexplored. We demonstrated the critical role of YAP in vascular endothelial cells and elucidated the underlying molecular mechanisms involved in angiogenic regulation of YAP. YAP was expressed in active angiogenic regions where endothelial cell junctions were relatively loosened. Consistently, YAP subcellular localization and activity were regulated by VE-cadherin-mediated PI3K/Akt pathway. YAP thereby regulated endothelial sprouting via angiopoietin-2 expression. These results provide an insight into a model of coordinating endothelial junctional stability and angiogenic activation through YAP. [BMB Reports 2015; 48(8): 429-430]

• Molecules and Cells
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• 제42권2호
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• pp.97-103
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• 2019

Androgens act in almost all tissues throughout the lifetime and have important roles in skeletal muscles. The levels of androgens increase during puberty and remain sustained at high levels in adulthood. Because androgens have an anabolic effect on skeletal muscles and muscle stem cells, these increased levels of androgens after puberty should lead to spontaneous muscle hypertrophy and hyperplasia in adulthood. However, the maintenance of muscle volume, myonuclei number per myofiber, and quiescent state of satellite cells in adulthood despite the high levels of androgens produces paradoxical outcomes. Our recent study revealed that the physiological increase of androgens at puberty initiates the transition of muscle stem cells from proliferation to quiescence by the androgen-Mindbomb1-Notch signaling axis. This newly discovered androgen action on skeletal muscles underscores the physiological importance of androgens on muscle homeostasis throughout life. This review will provide an overview of the new androgen action on skeletal muscles and discuss the paradoxical effects of androgens suggested in previous studies.

• 천문학회보
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• 제46권2호
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• pp.52.2-52.2
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• 2021

우리는 quiescent state magnetar의 물리적 특성을 연구하기 위해 복사특성이 잘 알려진 24개의 대상을 선정하였고 가장 어두운 시기(quiescent state)의 Chandra와 XMM-Newton의 X-ray 관측 데이터를 분석하여 복사특성과 시간 특성을 측정하였다. 이 측정을 이용하여 복사특성과 시간 특성 사이의 여러 경우에 대해 상관관계를 분석하였다. 그 결과 기존에 높은 상관관계를 갖는 것으로 알려진 표면 자기장(B_s)과 흑체복사 광도(L_BB), B_s와 X-ray photon index (Γ_X) 관계를 더 많은 magnetar에 대하여 재확인하였으며, spin-down rate (Ṗ)와 L_BB, characteristic age (𝜏_c)와 L_BB의 새로운 유의미한 관계를 찾았다. 또한 magnetar의 pulsed fraction (PF)과 흑체복사 반경(R_BB), PF와 Γ_X, 그리고 Ṗ과 Γ_X가 서로 상관되어 있다는 단서를 확인하였다.

• IMMUNE NETWORK
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• 제22권5호
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• pp.39.1-39.18
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• 2022

RNA metabolism plays a central role in regulating of T cell-mediated immunity. RNA processing, modifications, and regulations of RNA decay influence the tight and rapid regulation of gene expression during T cell phase transition. Thymic selection, quiescence maintenance, activation, differentiation, and effector functions of T cells are dependent on selective RNA modulations. Recent technical improvements have unveiled the complex crosstalk between RNAs and T cells. Moreover, resting T cells contain large amounts of untranslated mRNAs, implying that the regulation of RNA metabolism might be a key step in controlling gene expression. Considering the immunological significance of T cells for disease treatment, an understanding of RNA metabolism in T cells could provide new directions in harnessing T cells for therapeutic implications.

• International Journal of Stem Cells
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• 제17권3호
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• pp.213-223
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• 2024

Tissue-specific adult stem cells are pivotal in maintaining tissue homeostasis, especially in the rapidly renewing intestinal epithelium. At the heart of this process are leucine-rich repeat-containing G protein-coupled receptor 5-expressing crypt base columnar cells (CBCs) that differentiate into various intestinal epithelial cells. However, while these CBCs are vital for tissue turnover, they are vulnerable to cytotoxic agents. Recent advances indicate that alternative stem cell sources drive the epithelial regeneration post-injury. Techniques like lineage tracing and single-cell RNA sequencing, combined with in vitro organoid systems, highlight the remarkable cellular adaptability of the intestinal epithelium during repair. These regenerative responses are mediated by the reactivation of conserved stem cells, predominantly quiescent stem cells and revival stem cells. With focus on these cells, this review unpacks underlying mechanisms governing intestinal regeneration and explores their potential clinical applications.