• Journal of Electrochemical Science and Technology
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• 제4권2호
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• pp.47-56
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• 2013

Inhibition performance of Lornoxicam & Tenoxicam against corrosion of carbon steel in 1M $H_2SO_4$ solutions was investigated by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. The inhibition efficiency increased with increasing inhibitor's concentration, but decreased with increase in temperature. Potentiodynamic polarization curves showed that, the inhibitors were of mixed type. The apparent activation energy ($E^*_a$) and other thermodynamic parameters for the corrosion process have also been calculated and discussed. The inhibition of carbon steel corrosion is due to the adsorption of the inhibitor molecules on the surface, which follows Temkin adsorption isotherm. The mechanism of inhibition was discussed in the light of the chemical structure of the undertaken inhibitors.

• BMB Reports
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• 제53권11호
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• pp.600-604
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• 2020

Macrophages are re-educated and polarized in response to myocardial infarction (MI). The M2 anti-inflammatory phenotype is a known dominator of late stage MI. Mesenchymal stem cells (MSCs) represent a promising tool for cell therapy, particularly heart related diseases. In general, MSCs induce alteration of the macrophage subtype from M1 to M2, both in vitro and in vivo. We conjectured that hypoxic conditions can promote secretome productivity of MSCs. Hypoxia induces TGF-β1 expression, and TGF-β1 mediates M2 macrophage polarization for anti-inflammation and angiogenesis in infarcted areas. We hypothesized that macrophages undergo advanced M2 polarization after exposure to MSCs in hypoxia. Treatment of MSCs derived hypoxic conditioned medium (hypo-CM) promoted M2 phenotype and neovascularization through the TGF-β1/Smad3 pathway. In addition, hypo-CM derived from MSCs improved restoration of ischemic heart, such as attenuating cell apoptosis and fibrosis, and ameliorating microvessel density. Based on our results, we propose a new therapeutic method for effective MI treatment using regulation of macrophage polarization.

• 한국가스학회지
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• 제9권4호
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• pp.30-35
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• 2005

스테인리스 강재 STS444에 있어서 용접조건에 따른 수소취성의 전기화학적 분극특성을 고찰하고자 수소침투 실험과 전기화학적 분극실험을 실시하였다. 즉, $0.5M\; H_2SO_4+0.001M\;As_2O_3$ 수용액 중에서 $1,400kg/cm^2$의 하중을 부가하는 동시에 전기화학적 분극시험 장치로 $30mA/cm^2$전류를 60분간 인가하여 수소를 침투시켰으며 같은 수용액에서 양극분극실험을 하였다. STS444에 있어서 용접조건이 수소취성에 미치는 특성을 연구함에 있어 전보에서는 용접 전 기름이나 물의 흡착 영향으로 인장강도나 연신율이 낮아지는 현상을 규명하였지만, 본보에서는 기존의 보고된 수소취성의 발생 기구를 기초로 하여 전기화학적 부식거동을 접목하여 수소취성의 발생기구를 제안함으로써 부식전류밀도를 알면 수소취성의 민감 정도를 비파괴적으로 예측할 수 있을 것으로 판단된다.

• Parasites, Hosts and Diseases
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• 제58권3호
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• pp.217-227
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• 2020

Trichomonas vaginalis causes inflammation of the prostate and has been detected in tissues of prostate cancers (PCa), prostatitis and benign prostatic hyperplasia. Obesity is a risk factor for PCa and causes a chronic subclinical inflammation. This chronic inflammation further exacerbates adipose tissue inflammation as results of migration and activation of macrophages. Macrophages are the most abundant immune cells in the PCa microenvironment. M2 macrophages, known as Tumor-Associated Macrophages, are involved in increasing cancer malignancy. In this study, conditioned medium (TCM) of PCa cells infected with live trichomonads contained chemokines that stimulated migration of the mouse preadipocytes (3T3-L1 cells). Conditioned medium of adipocytes incubated with TCM (ATCM) contained Th2 cytokines (IL-4, IL-13). Macrophage migration was stimulated by ATCM. In macrophages treated with ATCM, expression of M2 markers increased, while M1 markers decreased. Therefore, it is suggested that ATCM induces polarization of M0 to M2 macrophages. In addition, conditioned medium from the macrophages incubated with ATCM stimulates the proliferation and invasiveness of PCa. Our findings suggest that interaction between inflamed PCa treated with T. vaginalis and adipocytes causes M2 macrophage polarization, so contributing to the progression of PCa.

• 한국세라믹학회지
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• 제43권3호
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• pp.162-168
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• 2006

The perovskites with nominal compositions $La_{0.8}Sr_{0.2}Fe_{1-x}M_xO_3$ (M=Co, Mn, Ni, x=0.1-0.3) were fabricated by a solid-state reaction method as cathode materials of low-temperature operating Solid Oxide Fuel Cells (SOFCs). X-ray diffraction analysis and microstructure observation for the sintered samples were performed. The ac complex impedance were measured in the temperature range $600-900^{\circ}C$ in air and fitted with a Solatron ZView program. The electrical conductivity and polarization resistance of $La_{0.8}Sr_{0.2}Fe_{1-x}M_xO_3$ (M=Co, Mn, Ni, x=0.1-0.3) were characterized systematically. The porosities of the sintered samples were in the range of 25% to 38%. The polarization resistance of $La_{0.8}Sr_{0.2}Fe_{0.7}M_{0.3}O_3$ was $0.291{\Omega}cm^2\;at\;700^{\circ}C$.

• 한국광학회지
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• 제13권1호
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• pp.32-37
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• 2002

두 모드 간섭 현상을 기초로 해서 1.55 $\mu\textrm{m}$ 파장대역에서 동작하는 편광모드 분리기를 Ti: x-cut LiNbO$_3$광도파로 구조를 이용하여 설계, 제작한 다음, TE, TM 입사 모드에 따른 소자의 동작 특성을 측정하였다. 광도파로 폭, 분기각도와 간섭영역 길이를 8$\mu\textrm{m}$, 0.55$^{\circ}$, 470$\mu\textrm{m}$로 제작된 소자의 분리 비는 TE, TM 입사 모드 각각에 대해서 16.18 dB, 21.25 dB로 측정되었으며, 누화는 -16.28 dB, -21.28 dB로 측정되었다. 삽입 손실은 TE, TM 각각에 대하여 2.24 dB/cm, 2.41 dB/cm로 측정되었으며. 30 nm 파장 범위 내에서 비교적 균일한 분리 비가 관찰되었다.

• 동의생리병리학회지
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• 제36권1호
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• pp.1-6
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• 2022

The tuber of Pinellia ternata (Thunb.) Brei (TPT) used in traditional Oriental medicine for the treatment of cough, sputum, vomiting, and insomnia, possesses antioxidant, antibacterial, and anti-inflammatory effects. Although recent studies have reported the anticancer effects of TPT in several cancer cells, it is still unclear whether TPT regulates tumor-associated macrophage (TAM) characterized by the immunosuppressive M2 macrophage phenotype. Our results showed that the ethanol extract of TPT (ETPT) suppressed the migration of RAW264.7 mouse macrophage cells and THP-1 human monocytes differentiated into macrophages towards the conditioned media (CM) collected from lung cancer cells, suggesting that ETPT would attenuate the recruitment of macrophages into tumors. In addition, ETPT suppressed the interleukin (IL)-4 or IL-6-induced M2 macrophage polarization in RAW264.7 cells. ETPT treatment not only downregulated the mRNA expression of M2 macrophage markers including arginase-1, mannose receptor C type 1 (MRC-1), and IL-10, but also inhibited the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and STAT6, general regulators of M2 macrophage polarization. Finally, the transwell assay results showed that the CM from M2-polarized RAW264.7 cells increased the migration of mouse lewis lung carcinoma (LLC) cells, while those from RAW264.7 cells co-treated with ETPT and IL-6 significantly reduced the migration of LLC cells. Taken together, our observations clearly demonstrate that ETPT suppressed the cancer cell migration by regulating macrophage recruitment and M2 macrophage polarization.

• IMMUNE NETWORK
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• 제22권4호
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• pp.33.1-33.17
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• 2022

Suppressors of cytokine signaling (SOCS) have emerged as potential regulators of macrophage function. We have investigated mechanisms of SOCS3 action on type 2 macrophage (M2) differentiation induced by glucocorticoid using human monocytic cell lines and mouse bone marrow-derived macrophages. Treatment of THP1 monocytic cells with dexamethasone (Dex) induced ROS generation and M2 polarization promoting IL-10 and TGF-β production, while suppressing IL-1β, TNF-α and IL-6 production. SOCS3 over-expression reduced, whereas SOCS3 ablation enhanced IL-10 and TGF-β induction with concomitant regulation of ROS. As a mediator of M2 differentiation, glucocorticoid-induced leucine zipper (GILZ) was down-regulated by SOCS3 and up-regulated by shSOCS3. The induction of GILZ and IL-10 by Dex was dependent on ROS and p38 MAPK activity. Importantly, GILZ ablation led to the inhibition of ROS generation and anti-inflammatory cytokine induction by Dex. Moreover, GILZ knock-down negated the up-regulation of IL-10 production induced by shSOCS3 transduction. Our data suggest that SOCS3 targets ROS- and p38-dependent GILZ expression to suppress Dex-induced M2 polarization.

• 한국축산식품학회지
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• 제43권4호
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• pp.703-711
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• 2023

As an initial study to elucidate the molecular mechanism of how probiotics modulate macrophage activity, we monitored mRNA expression patterns in peritoneal macrophages (PMs) treated with two different strains of probiotics. After treatment with either Weissella cibaria WIKIM28 or Latilactobacillus sakei WIKIM50, total RNAs from PMs were isolated and subjected into gene chip analyses. As controls, mRNAs from vehicle (phosphate-buffered saline, PBS)-treated PMs were also subjected to gene chip analysis. Compared to vehicle (PBS)-treated PMs, WIKIM28-treated and WIKIM50-treated PMs exhibited a total of 889 and 432 differentially expressed genes with expression differences of at least 4 folds, respectively. Compared to WIKIM28-treated PMs, WIKIM50-treated PMs showed 25 up-regulated genes and 21 down-regulated genes with expression differences of more than 2 folds. Interestingly, mRNA transcripts of M2 macrophage polarization marker such as anxa1, mafb, and sepp1 were increased in WIKIM50-treated PMs comparing to those in WIKIM28-treated PMs. Reversely, mRNA transcripts of M1 macrophage polarization marker such as hdac9, ptgs2, and socs3 were decreased in WIKIM50-treated PMs comparing to those in WIKIM28-treated PMs. In agreement with these observations, mRNA expression levels of tumor necrosis factor-α and interleukin-1α were significantly reduced in WIKIM50-treated macrophages compared to those in WIKIM28-treated macrophages. These results may indicate that probiotics can be classified as two different types depending on their ability to convert macrophages into M1 or M2 polarization.

• 천문학회지
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• 제56권1호
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• pp.1-9
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• 2023

The Crab nebula is widely used as a polarization angle calibrator for single-dish radio observations because of its brightness, high degree of linear polarization, and well-known polarization angle over a wide frequency range. However, the Crab nebula cannot be directly used as a polarization angle calibrator for single-dish observations with the Korean VLBI Network (KVN), because the beam size of the telescopes is smaller than the size of the nebula. To determine the polarization angle of the Crab nebula as seen by KVN, we use 3C 286, a compact polarized extragalactic radio source whose polarization angle is well-known, as a reference target. We observed both the Crab nebula and 3C 286 with the KVN from 2017 to 2021 and find that the polarization angles at the total intensity peak of the Crab nebula (equatorial coordinates (J2000) R.A. = 05^h34^m32.3804^s and Dec = 22°00'44.0982'') are 154.2° ± 0.3°, 151.0° ± 0.2°, 150.0° ± 1.0°, and 151.3° ± 1.1° at 22, 43, 86, and 94 GHz, respectively. We also find that the polarization angles at the pulsar position (RA = 05^h34^m31.971^s and Dec = 22°00'52.06'') are 154.4° ±0.4°, 150.7° ±0.4°, and 149.0° ± 1.0° for the KVN at 22, 43, and 86 GHz. At 129 GHz, we suggest to use the values 149.0° ± 1.6° at the total intensity peak and 150.2° ± 2.0° at the pulsar position obtained with the Institute for Radio Astronomy in the Millimeter Range (IRAM) 30-meter Telescope. Based on our study, both positions within the Crab nebula can be used as polarization angle calibrators for the KVN single-dish observations.