Monosodium urate crystal-induced triggering receptor expressed on myeloid cells 1 is associated with acute gouty inflammation

Lee, Jennifer,Lee, Seon-Young,Lee, Jaeseon,Lee, Juhyun,Baek, Seungye,Lee, Dong-Gun,Kim, Eun-Kyung,Lee, Sung Hak,Cho, Mi-La,Kwok, Seung-Ki,Ju, Ji Hyeon,Park, Sung-Hwan Oxford University Press 2016 Rheumatology Vol.55 No.1

<P>Objective. Triggering receptor expressed on myeloid cells 1 (TREM-1), which amplifies the inflammation elicited by the Toll-like receptor pathway, was originally implicated in sepsis and bacterial infection. However, it has been suggested that TREM-1 may also play an important role in non-infectious inflammation. The present study was conducted to investigate whether TREM-1 is involved in human acute gouty inflammation. Methods. A total of 37 gout patients were recruited between March 2011 and January 2014 from Seoul St Mary's Hospital. The expression of TREM-1 on mononuclear cells was assessed using FACS analysis, immunostaining and real-time RT-PCR. To block the TREM-1 signal, soluble TREM-1 (sTREM-1) or the synthetic blocking peptide LP17 was used. The concentration of sTREM-1 was assessed by ELISA. Results. FACS analysis and real-time RT-PCR demonstrated that TREM-1 expression was higher in the SF mononuclear cells of acute gouty arthritis patients than in peripheral blood mononuclear cells (PBMCs). Immunohistochemical staining of tophi tissues revealed TREM-1 expression, with confocal microscopy demonstrating TREM-1 expression on tophi tissue macrophages. We also demonstrated that MSU treatment induced TREM-1 expression on the PBMCs of acute gout patients in vitro. Although blockade of TREM-1 did not directly suppress MSU-induced IL-1 beta production of PBMCs in vitro, the concentration of soluble TREM-1 was higher in the SF of gout vs OA patients and was positively correlated with serum CRP. Conclusion. TREM-1 is induced by MSU and is associated with the inflammation of human acute gouty arthritis.</P>

Vaccinia‐related kinase 2 plays a critical role in microglia‐mediated synapse elimination during neurodevelopment

Lee, Juhyun,Lee, Seunghyun,Ryu, Young‐,Jae,Lee, Dohyun,Kim, Sangjune,Seo, Ji‐,Young,Oh, Eunji,Paek, Sun Ha,Kim, Seung U.,Ha, Chang‐,Man,Choi, Se‐,Young,Kim, Kyong‐,Tai John Wiley & Sons, Inc. 2019 Glia Vol.67 No.9

<P><B>Abstract</B></P><P>During postnatal neurodevelopment, excessive synapses must be eliminated by microglia to complete the establishment of neural circuits in the brain. The lack of synaptic regulation by microglia has been implicated in neurodevelopmental disorders such as autism, schizophrenia, and intellectual disability. Here we suggest that vaccinia‐related kinase 2 (VRK2), which is expressed in microglia, may stimulate synaptic elimination by microglia. In VRK2‐deficient mice (VRK2<SUP>KO</SUP>), reduced numbers of presynaptic puncta within microglia were observed. Moreover, the numbers of presynaptic puncta and synapses were abnormally increased in VRK2<SUP>KO</SUP> mice by the second postnatal week. These differences did not persist into adulthood. Even though an increase in the number of synapses was normalized, adult VRK2<SUP>KO</SUP> mice showed behavioral defects in social behaviors, contextual fear memory, and spatial memory.</P><P><B>Main points</B></P><P>VRK2 is specifically expressed in microglia in the brain. The number of presynaptic puncta within microglia was reduced in VRK2<SUP>KO</SUP> mice. Adult VRK2<SUP>KO</SUP> mice displayed several behavioral deficits. </P>

Phase Jitter Analysis of Overlapped Signals for All-to-All TWSTFT Operation

Juhyun Lee,Ju-Ik Oh,Joon Hyo Rhee,Gyeong Won Choi,Young Kyu Lee,Jong Koo Lee,Sung-hoon Yang 사단법인 항법시스템학회 2023 Journal of Positioning, Navigation, and Timing Vol.12 No.3

Time comparison techniques are necessary for generating and keeping Coordinated Universal Time (UTC) and distributing standard time clocks. Global Navigation Satellite System (GNSS) Common View, GNSS All-in-View, Two-Way Satellite Time and Frequency Transfer (TWSTFT), Very Long Baseline Interferometry (VLBI), optical fiber, and Network Time Protocol (NTP) based methods have been used for time comparison. In these methods, GNSS based time comparison techniques are widely used for time synchronization in critical national infrastructures and in common areas of application such as finance, military, and wireless communication. However, GNSS-based time comparison techniques are vulnerable to jamming or interference environments and it is difficult to respond to GNSS signal disconnection according to the international situation. In response, in this paper, Code-Division Multiple Access (CDMA) based All-to-All TWSTFT operation method is proposed. A softwarebased simulation platform also was designed for performance analysis in multi-TWSTFT signal environments. Furthermore, code and carrier measurement jitters were calculated in multi-signal environments using the designed simulation platform. By using the technique proposed in this paper, it is anticipated that the TWSTFT-based time comparison method will be used in various fields and satisfy high-performance requirements such as those of a GNSS master station and power plant network reference station.

5-Lipoxygenase mediates RANKL-induced osteoclast formation via the cysteinyl leukotriene receptor 1.

Lee, Jung-Min,Park, Hyojung,Noh, A Long Sae Mi,Kang, Ju-Hee,Chen, Ling,Zheng, Ting,Lee, Juhyun,Ji, Sun-Young,Jang, Chang-Young,Shin, Chan Soo,Ha, Hyunil,Lee, Zang Hee,Park, Hea-Young,Lee, Dong-Seok,Yi American Association of Immunologists 2012 Journal of Immunology Vol. No.

<P>5-Lipoxygenase (5-LO) catalyzes the formation of two major groups of leukotrienes, leukotriene B4 and cysteinyl leukotrienes (CysLTs), and it has been implicated as a promising drug target to treat various inflammatory diseases. However, its role in osteoclastogenesis has not been investigated. In this study, we used mouse bone marrow-derived macrophages (BMMs) to show that 5-LO inhibitor suppresses RANKL-induced osteoclast formation. Inhibition of 5-LO was associated with impaired activation of multiple signaling events downstream of RANK, including ERK and p38 phosphorylation, and IκB degradation, followed by a decrease in NFATc1 expression. Ectopic overexpression of a constitutively active form of NFATc1 partly rescued the antiosteoclastogenic effect of 5-LO inhibitor. The knockdown of 5-LO in BMMs also resulted in a significant reduction in RANKL-induced osteoclast formation, accompanied by decreased expression of NFATc1. Similar effects were shown with CysLT receptor (CysLTR)1/2 antagonist and small RNA for CysLTR1 in BMMs, indicating the involvement of CysLT and CysLTR1 in 5-LO-mediated osteoclastogenesis. Finally, 5-LO inhibitor suppressed LPS-induced osteoclast formation and bone loss in the in vivo mouse experiments, suggesting a potential therapeutic strategy for treating diseases involving bone destruction. Taken together, the results of this study demonstrate that 5-LO is a key mediator of RANKL-induced osteoclast formation and possibly a novel therapeutic target for bone-resorption diseases.</P>

Improved Method and Message Structure Design for TWSTFT without Extra Network

Juhyun Lee,Ju-Ik Oh,Young Kyu Lee,Sung-hoon Yang,Jong Koo Lee,Joon Hyo Rhee 사단법인 항법시스템학회 2023 Journal of Positioning, Navigation, and Timing Vol.12 No.2

Time comparison techniques are required for generating and keeping Coordinated Universal Time (UTC) and to distribute standard clocks. These techniques play an important role in various fields, including science, finance, military, and communication. Among these techniques, Two-Way Satellite Time and Frequency Transfer (TWSTFT) ensures a relatively high accuracy, with a time comparison accuracy at a nanosecond level. However, TWSTFT systems have some limitations, such as the dependency on extra network links. In this paper, we propose an improved method for TWSTFT system operation and design a message structure for the suggestion. Additionally, we estimate the data rate and redundancy for the new TWSTFT signal with the designed message structure.

Aromadendrin Inhibits Lipopolysaccharide-Induced Inflammation in BEAS-2B Cells and Lungs of Mice

Lee Juhyun,Park Ji-Won,Choi Jinseon,Yun Seok Han,Rhee Bong Hyo,Jeong Hyeon Jeong,Kim Hyueyun,Lee Kihoon,Ahn Kyung-Seop,Jeong Hye-Gwang,Lee Jae-Won 한국응용약물학회 2024 Biomolecules & Therapeutics(구 응용약물학회지) Vol.32 No.5

Aromadendrin is a phenolic compound with various biological effects such as anti-inflammatory properties. However, its protective effects against acute lung injury (ALI) remain unclear. Therefore, this study aimed to explore the ameliorative effects of aromadendrin in an experimental model of lipopolysaccharide (LPS)-induced ALI. In vitro analysis revealed a notable increase in the levels of cytokine/chemokine formation, nuclear factor kappa B (NF-κB) activation, and myeloid differentiation primary response 88 (MyD88)/toll-like receptor (TLR4) expression in LPS-stimulated BEAS-2B lung epithelial cell lines that was ameliorated by aromadendrin pretreatment. In LPS-induced ALI mice, the remarkable upregulation of immune cells and IL-1β/IL-6/TNF-α levels in the bronchoalveolar lavage fluid and inducible nitric oxide synthase/cyclooxygenase-2/CD68 expression in lung was decreased by the oral administration of aromadendrin. Histological analysis revealed the presence of cells in the lungs of ALI mice, which was alleviated by aromadendrin. In addition, aromadendrin ameliorated lung edema. This in vivo effect of aromadendrin was accompanied by its inhibitory effect on LPS-induced NF-κB activation, MyD88/TLR4 expression, and signal transducer and activator of transcription 3 activation. Furthermore, aromadendrin increased the expression of heme oxygenase-1/ NAD(P)H quinone dehydrogenase 1 in the lungs of ALI mice. In summary, the in vitro and in vivo studies demonstrated that aromadendrin ameliorated endotoxin-induced pulmonary inflammation by suppressing cytokine formation and NF-κB activation, suggesting that aromadendrin could be a useful adjuvant in the treatment of ALI.

스마트폰을 이용한 현장 중계 방송 시스템의 개발과 활용

오주현(Juhyun Oh),김현순(Hyunsoon Kim),이윤재(Yoonjae Lee),이만규(Mankyu Lee),이영일(Youngil Lee),이민석(Minsuk Lee) 한국방송·미디어공학회 2016 한국방송공학회 학술발표대회 논문집 Vol.2016 No.6

NFT 커뮤니티 소속감 증진을 위한 가상공간 플랫폼 활용 연구

이주현 (Juhyun Lee ),이진재 (Marvin Lee ),김보원 (Bowon Kim),이지현(Ji-Hyun Lee ) 한국디자인리서치학회 2022 한국디자인리서치학회 학술대회 자료집 Vol.2022 No.1

While NFT has dominated the headlines in the last two years, the debate over the actual value of the NFTs have continued, with no clear answer. In this paper, we strive to suggest one of the ways to reinforce psychological value to the underlying tokens. NFT, as one of the derivatives of blockchain technology, has quickly developed its own quirks and peculiarity since the mid-2010s when it was first conceived. The more complex as the NFT markets got, the more delicate the needs of the NFT consumer and the producers became. For example, NFT has developed a culture of community around its tokens, and the exchange of information and hierarchy system within this said community has proven extremely important, not just for the community support, but also going on to determine the actual value of the NFT itself. Within these hierarchical community, one of the accepted means of social advancement is through fulfilling whitelist missions. This draws a lot of parallel to how luxury conglomerates operate and reinforce their aura of exclusivity. We have taken inspiration from this to see if we can create a luxurious experience online through the usage of Whitelist, in order to imbue more value to the underlying NFT tokens.

Fabrication of high crystalline SnS and SnS₂ thin films, and their switching device characteristics

Choi, Hyeongsu,Lee, Jeongsu,Shin, Seokyoon,Lee, Juhyun,Lee, Seungjin,Park, Hyunwoo,Kwon, Sejin,Lee, Namgue,Bang, Minwook,Lee, Seung-Beck,Jeon, Hyeongtag IOP Pub 2018 Nanotechnology Vol.29 No.21

<P>Representative tin sulfide compounds, tin monosulfide (SnS) and tin disulfide (SnS<SUB>2</SUB>) are strong candidates for future nanoelectronic devices, based on non-toxicity, low cost, unique structures and optoelectronic properties. However, it is insufficient for synthesizing of tin sulfide thin films using vapor phase deposition method which is capable of fabricating reproducible device and securing high quality films, and their device characteristics. In this study, we obtained highly crystalline SnS thin films by atomic layer deposition and obtained highly crystalline SnS<SUB>2</SUB> thin films by phase transition of the SnS thin films. The SnS thin film was transformed into SnS<SUB>2</SUB> thin film by annealing at 450 °C for 1 h in H<SUB>2</SUB>S atmosphere. This phase transition was confirmed by x-ray diffractometer and x-ray photoelectron spectroscopy, and we studied the cause of the phase transition. We then compared the film characteristics of these two tin sulfide thin films and their switching device characteristics. SnS and SnS<SUB>2</SUB> thin films had optical bandgaps of 1.35 and 2.70 eV, and absorption coefficients of about 10<SUP>5</SUP> and 10<SUP>4</SUP> cm<SUP>−1</SUP> in the visible region, respectively. In addition, SnS and SnS<SUB>2</SUB> thin films exhibited p-type and n-type semiconductor characteristics. In the images of high resolution-transmission electron microscopy, SnS and SnS<SUB>2</SUB> directly showed a highly crystalline orthorhombic and hexagonal layered structure. The field effect transistors of SnS and SnS<SUB>2</SUB> thin films exhibited on–off drain current ratios of 8.8 and 2.1 × 10<SUP>3</SUP> and mobilities of 0.21 and 0.014 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>, respectively. This difference in switching device characteristics mainly depends on the carrier concentration because it contributes to off-state conductance and mobility. The major carrier concentrations of the SnS and SnS<SUB>2</SUB> thin films were 6.0?×?10<SUP>16</SUP> and 8.7?×?10<SUP>13</SUP> cm<SUP>−3</SUP>, respectively, in this experiment.</P>

On determining a non-periodic preventive maintenance schedule using the failure rate threshold for a repairable system

Juhyun Lee,Jihyun Park,Suneung Ahn 국제구조공학회 2018 Smart Structures and Systems, An International Jou Vol.22 No.2

Maintenance activities are regarded as a key part of the repairable deteriorating system because they maintain the equipment in good condition. In practice, many maintenance policies are used in engineering fields to reduce unexpected failures and slow down the deterioration of the system. However, in traditional maintenance policies, maintenance activities have often been assumed to be performed at the same time interval, which may result in higher operational costs and more system failures. Thus, this study presents two non-periodic preventive maintenance (PM) policies for repairable deteriorating systems, employing the failure rate of the system as a conditional variable. In the proposed PM models, the failure rate of the system was restored via the failure rate reduction factors after imperfect PM activities. Operational costs were also considered, which increased along with the operating time of the system and the frequency of PM activities to reflect the deterioration process of the system. A numerical example was provided to illustrate the proposed PM policy. The results showed that PM activities performed at a low failure rate threshold slowed down the degradation of the system and thus extended the system lifetime. Moreover, when the operational cost was considered in the proposed maintenance scheme, the system replacement was more cost-effective than frequent PM activities in the severely degraded system.