• 한국분말재료학회지
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• 제13권4호
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• pp.243-249
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• 2006

Yttrium aluminum garnet (YAG) powders were synthesized via mechanochemical solid reaction using $Y_2O_3$ with three types of aluminum compounds. $Y_2O_3$ reacted mechanochemically with all A1 compounds and formed YAM (yttrium aluminum monoclinic), YAG and YAP (yttrium aluminum perovskite) phases depending on the starting materials. The ground samples containing ${\gamma}-A1_2O_3$ showed the best reactivity, whereas the ground sample containing A100H, which had the largest surface area, exhibited pure YAG after calcination at $1200^{\circ}C$. The sample containing Al had the least reactivity, producing YAP along with YAG at $1200^{\circ}C$. The types and grinding characteristics of the starting materials and grinding time are believed to be important factors in the mechanochemical synthesis of YAG.

• 한국해양학회지:바다
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• 제3권4호
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• pp.214-227
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• 1998

중앙태평양 마이크로네시아 군도 해저산 일원에서 발견되는 탄산염암의 구성성분과 속성작용을 이해하기 위하여 조직적, 지화학적 연구를 수행하였다. 연구지역은 Caroline 해령, Chuuk 섬, Hunter 뱅크, Yap 해구 일대이며, 대부분의 시료들은 수심 약 1,000~3,000 m 깊이에서 준설된 것들이다. 연구지역에서 발견되는 탄산염암은 부유성 유공충으로 이루어진 원양성 퇴적물과 산호, 석회조류, 연체동물 및 극피류 등으로 이루어진 천해퇴적물의 두 종류가 있다. 이들 퇴적물은 Hunter 뱅크와 Yap A 지역을 제외하고는 모두 조직적, 화학적 속성변질을 받았다. 천해기원 교질물들이 발견되므로, 천해에서 퇴적된 후 현재의 깊이로 침강되었거나 재동된 것으로 사료된다. 조직 특성은 천수에 의한 속성변질산물과 매우 유사한 양상을 보여주나, 변질된 시료의 탄소동위원소는 해수기원 탄소의 특성을 보여주며, 산소동위원소는 변질되지 않은 시료와 같거나 부화된 값을 보여준다. 따라서 이 지역의 탄산염암은 심해의 해수에 의해 변질되었음을 알 수 있다.

• BMB Reports
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• 제51권3호
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• pp.143-150
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• 2018

The Hippo signaling pathway plays an essential role in adult tissue homeostasis and organ size control. Abnormal regulation of Hippo signaling can be a cause for multiple types of human cancers. Since the awareness of the importance of the Hippo signaling in a wide range of biological fields has been continually grown, it is also understood that a thorough and well-rounded comprehension of the precise dynamics could provide fundamental insights for therapeutic applications. Several components in the Hippo signaling pathway are known to be targeted for proteasomal degradation via ubiquitination by E3 ligases. ${\beta}-TrCP$ is a well-known E3 ligase of YAP/TAZ, which leads to the reduction of YAP/TAZ levels. The Hippo signaling pathway can also be inhibited by the E3 ligases (such as ITCH) which target LATS1/2 for degradation. Regulation via ubiquitination involves not only complex network of E3 ligases but also deubiquitinating enzymes (DUBs), which remove ubiquitin from its targets. Interestingly, non-degradative ubiquitin modifications are also known to play important roles in the regulation of Hippo signaling. Although there has been much advanced progress in the investigation of ubiquitin modifications acting as regulators of the Hippo signaling pathway, research done to date still remains inadequate due to the sheer complexity and diversity of the subject. Herein, we review and discuss recent developments that implicate ubiquitin-mediated regulatory mechanisms at multiple steps of the Hippo signaling pathway.

• IMMUNE NETWORK
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• 제20권5호
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• pp.36.1-36.13
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• 2020

Hippo signaling pathways are evolutionarily conserved signal transduction mechanisms mainly involved in organ size control, tissue regeneration, and tumor suppression. However, in mammals, the primary role of Hippo signaling seems to be regulation of immunity. As such, humans with null mutations in STK4 (mammalian homologue of Drosophila Hippo; also known as MST1) suffer from recurrent infections and autoimmune symptoms. Although dysregulated T cell homeostasis and functions have been identified in MST1-deficient human patients and mouse models, detailed cellular and molecular bases of the immune dysfunction remain to be elucidated. Although the canonical Hippo signaling pathway involves transcriptional co-activator Yes-associated protein (YAP) or transcriptional coactivator with PDZ motif (TAZ), the major Hippo downstream signaling pathways in T cells are YAP/TAZ-independent and they widely differ between T cell subsets. Here we will review Hippo signaling mechanisms in T cell immunity and describe their implications for immune defects found in MST1-deficient patients and animals. Further, we propose that mutual inhibition of Mst and Akt kinases and their opposing roles on the stability and function of forkhead box O and β-catenin may explain various immune defects discovered in mutant mice lacking Hippo signaling components. Understanding these diverse Hippo signaling pathways and their interplay with other evolutionarily-conserved signaling components in T cells may uncover molecular targets relevant to vaccination, autoimmune diseases, and cancer immunotherapies.

• Journal of Communications and Networks
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• 제13권1호
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• pp.26-31
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• 2011

In this paper, we formulate the minimum power multicast problem in wireless networks as a mixed integer linear programming problem and then propose a Lagrangean relaxation based algorithm to solve this problem. By leveraging on the information from the Lagrangean multiplier, we could construct more power efficient routing paths. Numerical results demonstrate that the proposed approach outperforms the existing approaches for broadcast, multicast, and unicast communications.

• BMB Reports
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• 제53권8호
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• pp.413-418
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• 2020

ANKHD1 (ankyrin repeat and KH domain containing 1) is a large protein characterized by the presence of multiple ankyrin repeats and a K-homology domain. Ankyrin repeat domains consist of widely existing protein motifs in nature, they mediate protein-protein interactions and regulate fundamental biological processes, while the KH domain binds to RNA or ssDNA and is associated with transcriptional and translational regulation. In recent years, studies containing relevant information on ANKHD1 in cancer biology and its clinical relevance, as well as the increasing complexity of signaling networks in which this protein acts, have been reported. Among the signaling pathways of interest in oncology regulated by ANKHD1 are Hippo signaling, JAK/STAT, and STMN1. The scope of the present review is to survey the current knowledge and highlight future perspectives for ANKHD1 in the malignant phenotype of cancer cells, exploring biological, functional, and clinical reports of this protein in cancer.

• 대한한의학방제학회지
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• 제32권1호
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• pp.51-61
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• 2024

Objectives : This study induced oxidative stress in HepG2 cells by treating them with AA+iron and investigated the effects of forsythia suspensa extract on this stress, as well as elucidated the molecular mechanisms underlying its hepatoprotective effects. Methods : To confirm the antioxidative effects of FSE, HepG2 cells were induced with AA+iron to induce oxidative stress, followed by MTT assay. Additionally, the effect of FSE in reducing the increased ROS levels and mitochondrial damage induced by AA+iron in HepG2 cells was confirmed using FACS. Furthermore, western blot analysis were conducted to investigate the molecular mechanisms underlying the hepatoprotective effects of FSE. Results : FSE increased the decreased cell viability induced by AA+iron. Additionally, FSE normalized the expression of apoptosis-related proteins induced by AA+iron. The elevated ROS levels in HepG2 cells induced by AA+iron were reduced by FSE, and the increase in Rh123-negative cells induced by AA+iron was attenuated by FSE. Moreover, FSE activated the protein expression of AMPK and its related phosphorylating enzymes, LKB1 and ACC. Furthermore, FSE activated YAP and its upstream phosphorylating enzyme, LATS1. Conclusions : These results demonstrate that FSE has an inhibitory effect on oxidative stress induced by AA+iron and may have potential hepatoprotective effects.

• Natural Product Sciences
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• 제13권2호
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• pp.110-113
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• 2007

Five flavonoid derivatives, pinostrobin (1), pinocembrin (2), alpinetin (3), cardamonin (4) and boesenbergin A (5) were isolated from the rhizomes of Boesenbergia pandurata. All compounds were elucidated based on its spectroscopic data and by the comparison with the previous works. 2D NMR technique was used for the structure elucidation of boesenbergin A to complement the data reported previously. The extracts and pure compounds were screened for cytotoxic activity against HL-60 cancer cell lines (human promyelocytic leukemia). Cytotoxic screening showed most of the extracts and pure compounds isolated from the rhizomes of Boesenbergia pandurata were active against HL-60 cancer cell line. The chloroform extract and boesenbergin A showed the most potent cytotoxic activity.

• Journal of Microbiology and Biotechnology
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• 제25권1호
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• pp.50-56
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• 2015

During pretreatment of lignocellulosic biomass, a variety of fermentation inhibitors, including acetic acid and vanillin, are released. Using DNA microarray analysis, this study explored genes of the budding yeast Saccharomyces cerevisiae that respond to vanillin-induced stress. The expression of 273 genes was upregulated and that of 205 genes was downregulated under vanillin stress. Significantly induced genes included MCH2, SNG1, GPH1, and TMA10, whereas NOP2, UTP18, FUR1, and SPR1 were down regulated. Sequence analysis of the 5'-flanking region of upregulated genes suggested that vanillin might regulate gene expression in a stress response element (STRE)-dependent manner, in addition to a pathway that involved the transcription factor Yap1p. Retardation in the cell growth of mutant strains indicated that MCH2, SNG1, and GPH1 are intimately involved in vanillin stress response. Deletion of the genes whose expression levels were decreased under vanillin stress did not result in a notable change in S. cerevisiae growth under vanillin stress. This study will provide the basis for a better understanding of the stress response of the yeast S. cerevisiae to fermentation inhibitors.

• 한국분말재료학회지
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• 제20권1호
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• pp.37-42
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• 2013

$YAG:Ce^{3+}$ phosphor powders were synthesized using a $Al_2O_3$ seed (average particle size: 5 ${\mu}m$) by the polymer solution route. PVA solution was added to the sol precursors consisting of the seed powder and metal nitrate salts for homogeneous mixing in atomic scale. All dried precursor gels were calcined at $500^{\circ}C$ and then heated at $1400^{\circ}C{\sim}1500^{\circ}C$ in $N_2/H_2$ atmosphere. The final powders were characterized by using XRD, SEM, PSA, PL and PKG test. All synthesized powders were crystallized to YAG phase without intermediate phases of YAM or YAP. The phosphor properties and morphologies of the synthesized powders were strongly dependent on the PVA content. Finally, the synthesized $YAG:Ce^{3+}$ phosphor powder heated at $1500^{\circ}C$, which is prepared from 12:1 PVA content and has an average particle size of 15 ${\mu}m$, showed similar phosphor properties to a commercial phosphor powder.