• Title/Summary/Keyword: 신호효과

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Comparative analysis of wavelet transform and machine learning approaches for noise reduction in water level data (웨이블릿 변환과 기계 학습 접근법을 이용한 수위 데이터의 노이즈 제거 비교 분석)

  • Hwang, Yukwan;Lim, Kyoung Jae;Kim, Jonggun;Shin, Minhwan;Park, Youn Shik;Shin, Yongchul;Ji, Bongjun
    • Journal of Korea Water Resources Association
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    • v.57 no.3
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    • pp.209-223
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    • 2024
  • In the context of the fourth industrial revolution, data-driven decision-making has increasingly become pivotal. However, the integrity of data analysis is compromised if data quality is not adequately ensured, potentially leading to biased interpretations. This is particularly critical for water level data, essential for water resource management, which often encounters quality issues such as missing values, spikes, and noise. This study addresses the challenge of noise-induced data quality deterioration, which complicates trend analysis and may produce anomalous outliers. To mitigate this issue, we propose a noise removal strategy employing Wavelet Transform, a technique renowned for its efficacy in signal processing and noise elimination. The advantage of Wavelet Transform lies in its operational efficiency - it reduces both time and costs as it obviates the need for acquiring the true values of collected data. This study conducted a comparative performance evaluation between our Wavelet Transform-based approach and the Denoising Autoencoder, a prominent machine learning method for noise reduction.. The findings demonstrate that the Coiflets wavelet function outperforms the Denoising Autoencoder across various metrics, including Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), and Mean Squared Error (MSE). The superiority of the Coiflets function suggests that selecting an appropriate wavelet function tailored to the specific application environment can effectively address data quality issues caused by noise. This study underscores the potential of Wavelet Transform as a robust tool for enhancing the quality of water level data, thereby contributing to the reliability of water resource management decisions.

Inhibitory effect of ethanol extract of Gryllus bimaculatus on platelet aggregation and glycoprotein IIb/IIIa activation (쌍별귀뚜라미 에탄올 추출물의 혈소판응집반응과 당단백질 IIb/IIIa 활성화 억제 효과)

  • Hyuk-Woo Kwon;Man Hee Rhee;Jung-Hae Shin
    • Journal of Applied Biological Chemistry
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    • v.66
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    • pp.236-243
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    • 2023
  • Platelets act a fundamental role in primary- and secondary-hemostasis, however, platelet activation may cause thrombosis simultaneously. Therefore, control of platelet aggregation is crucial in preventing thrombosis-mediated diseases. Recently, the development of insect materials is attracting attention. Among the highly nutritious functional food sources, insects such as two-spotted cricket (Gryllus bimaculatus). Gryllus bimaculatus (G. bimaculatus) contains high protein and unsaturated fatty acids and has been registered as a food material September 2015 by the Ministry of Food and Drug Safety of Korea. In this study, we examined whether G. bimaculatus extract (GBE) inhibits platelet aggregation, intracellular calcium mobilization, thromboxane A2 production and glycoprotein IIb/IIIa (integrin αIIb/β3) activation. We investigated whether GBE can regulate signaling molecules, such as 1, 4, 5-triphosphate receptor type I, extracellular signal-regulated kinase, cytosolic phospholipase A2, mitogen-activated protein kinases p38, vasodilator-stimulated phosphoprotein, phosphatidylinositol-3 kinase, Akt, glycogen synthase kinase-3α/β, and SYK. Taken together, GBE is a potential therapeutic drug candidate to prevent platelet-related thrombosis and cardiovascular disease.

Analysis of Color Distortion in Hazy Images (안개가 포함된 영상에서의 색 왜곡 특성 분석)

  • JeongYeop Kim
    • Journal of Platform Technology
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    • v.11 no.6
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    • pp.68-78
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    • 2023
  • In this paper, the color distortion in images with haze would be analyzed. When haze is included in the scene, the color signal reflected in the scene is accompanied by color distortion due to the influence of transmittance according to the haze component. When the influence of haze is excluded by a conventional de-hazing method, the distortion of color tends to not be sufficiently resolved. Khoury et al. used the dark channel priority technique, a haze model mentioned in many studies, to determine the degree of color distortion. However, only the tendency of distortion such as color error values was confirmed, and specific color distortion analysis was not performed. This paper analyzes the characteristic of color distortion and proposes a restoration method that can reduce color distortion. Input images of databases used by Khoury et al. include Macbeth color checker, a standard color tool. Using Macbeth color checker's color values, color distortion according to changes in haze concentration was analyzed, and a new color distortion model was proposed through modeling. The proposed method is to obtain a mapping function using the change in chromaticity by step according to the change in haze concentration and the color of the ground truth. Since the form of color distortion varies from step to step in proportion to the haze concentration, it is necessary to obtain an integrated thought function that operates stably at all stages. In this paper, the improvement of color distortion through the proposed method was estimated based on the value of angular error, and it was verified that there was an improvement effect of about 15% compared to the conventional method.

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Inhibitory Effects of Amitriptyline, Sertraline and Chlorpromazine on the Thrombin-induced Aggregation of Platelets (Thrombin성 혈소판응집에 대한 Amitriptyline, Sertraline 및 Chlorpromazine의 억제작용)

  • Choi, Sang-Hyun;Lee, Young-Jae;Shin, Kyung-Ho;Chun, Yeon-Sook;Chun, Boe-Gwun
    • The Korean Journal of Pharmacology
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    • v.31 no.3
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    • pp.299-311
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    • 1995
  • Platelets resemble monoaminergic neurons in several respects, i.e. the uptake of 5-HT and its inhibition, the subcellular storage and release of 5-HT, and the metabolism of aromatic amines brought about by monoamine oxidase. And the 5-HT content of rabbit platelets is well known to be about 40 times higher than that of human platelets. Therefore, this study was carried out to investigate the influences of amitriptyline (AMT) and sertraline (SRT) on the aggregation, contents of signaling second messengers, and protein phosphorylations of rabbit platelets in response to thrombin, 0.25 unit/ml, comparing with those of chlorpromazine (CPZ). Thrombin-induced aggregation was inhibited by SRT $(IC50:4.37{\times}10^{-5}\;M)$, CPZ $(IC50:5.76{\times}10^{-5}\;M)$, and AMT $(IC50:1.15{\times}10^{-4}\;M)$, respectively, and the aggregation by A23187 $(1.0\;{\mu}M)$ or PMA (320 nM) was also inhibited by SRT, CPZ, and AMT. AMT, SRT, and CPZ had little affects on basal contents of platelet $TXB_2$ and $PGE_2$, but all of them inhibited the thrombin-induced increase of $TXB_2$. Thrombin did not change the platelet contents of cAMP and cGMP. CPZ, AMT, and SRT produced the slight decrease of basal cAMP content, and their effects were not affected by thrombin-treatment. But SRT and AMT moderately increased the basal cGMP content, and the cGMP content of thrombin-stimulated platelets was gradually increased by the pretreatment with SRT, AMT, and CPZ. Particularly, the SRT-dependent increase of the cGMP content was notable. Platelet $Ins(1,4,5)P_3$ content was rapidly increased up to a plateau within 10 sec after thrombin-stimulation, AMT, SRT, and CPZ increased the basal $Ins(1,4,5)P_3$ content, and the thrombin-dependent increase was enhanced by pretreatment with CPZ and AMT, but was blunted by SRT. Platelet $[Ca^{2+}]_i$, was rapidly increased up to a peak level within 20 sec after thrombin-stimulation. The increase of $[Ca^{2+}]_i$ was sisnificantly inhibited by AMT, SRT, and CPZ. Thrombin- or PMA-induced phosphorylations of platelet $41{\sim}43\;kDa$ and 20 kDa proteins were significantly inhibited by AMT, SRT, and CPZ. These results suggest that the antiplatelet activities of AMT and CPZ may be considerably attributed to the inhibition of protein kinase C activity, and the activity of SRT may be associated with the inhibitory effect on the thrombin-induced increase of $Ins(1,4,5)P_3$ and the increasing effect on the cGMP content of ptatelets. Therefore, it seems to be evident that AMT and SRT may produce their antidepressant activity, at least, partly through the inhibition of protein kinase C activity or the increase of resting $Ins(1,4,5)P_3$, content and in case of SRT, to a lesser extent, via the increase of cGMP in the brain.

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Socheongja and Socheong 2 Extracts Suppress Lipopolysaccharide-induced Inflammation and Oxidative Stress in RAW 264.7 Macrophages through Activating Nrf2/HO-1 Signaling and Suppressing MAPKs Pathway (RAW 264.7 대식세포에서 Nrf2/HO-1 신호 전달계 활성화와 MAPKs 경로 억제를 통한 소청자와 소청2호의 LPS 매개 염증성 및 산화적 스트레스 반응의 억제)

  • Kwon, Da Hye;Choi, Eun Ok;Hwang, Hye-Jin;Kim, Kook Jin;Hong, Su Hyun;Lee, Dong Hee;Choi, Yung Hyun
    • Journal of Life Science
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    • v.28 no.2
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    • pp.207-215
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    • 2018
  • Inflammatory response and oxidative stress play critical roles in the development and progression of many human diseases. Therefore, a great deal of attention has been focused on finding functional materials that can control inflammation and oxidative stress simultaneously. The purpose of this study was to investigate the effects of Socheongja and Socheong 2, Korean black seed coat soybean varieties, on the inflammatory and oxidative stress induced by lipopolysaccharide (LPS) in RAW 264.7 macrophages. Our data indicated that the extracts of Socheongja (SCJ) and Socheong 2 (SC2) significantly suppressed LPS-induced production of nitrite oxide (NO) and prostaglandin $E_2$, key pro-inflammatory mediators, by suppressing the expression of inducible NO synthase and cyclooxygenase-2. It was also found that SCJ and SC2 reduced the LPS-induced secretion of pro-inflammatory cytokines, such as tumor necrosis $factor-{\alpha}$ and $interleukin-1{\beta}$, which was concomitant with a decrease in the protein levels. In addition, SCJ and SC2 markedly diminished LPS-stimulated intracellular reactive oxygen species accumulation, and effectively enhanced nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase (HO)-1 expression. Furthermore, LPS-induced activation of mitogen-activated protein kinases (MAPKs) was abrogated by SCJ and SC2. Taken together, these data suggest that SCJ and SC2 may offer protective roles against LPS-induced inflammatory and oxidative responses in RAW 264.7 macrophages through attenuating MAPKs pathway, and these effects are mediated, at least in part, through activating Nrf2/HO-1 pathway. Given these results, we propose that SCJ and SC2 have therapeutic potential in the treatment of inflammatory and oxidative disorders caused by over-activation of macrophages.

Inhibitory Effect of Steviol and Its Derivatives on Cell Migration via Regulation of Tight Junction-related Protein Claudin 8 (스테비올 및 그 유도체의 세포연접 관련 클라우딘 8 발현 조절을 통한 세포이동 저해효과)

  • Choi, Sun Kyung;Cho, Nam Joon;Cho, Uk Min;Shim, Joong Hyun;Kim, Kee K.;Hwang, Hyung Seo
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.42 no.4
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    • pp.403-412
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    • 2016
  • The tight junction, one of Intercellular junctions, performs a variety of biological functions by bonding adjacent cells, including the barrier function to control the movement of the electrolyte and water. Recent studies have revealed that unusual expression of tight junction-related genes have been shown to be related in cancer development and progression. Recently, there are many reports that control of tight junction proteins expression is closely related to the skin moisture. In this study, we are focusing on the regulating mechanism of tight junction-associated genes by the steviol and its derivatives. Steviol, used as a sweetner, is known to chemical compound isolated from stevia plant. The MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) assay was carried out in HaCaT cells (human keratinocyte cell line) in order to determine the cytotoxicity. As a result, while steviol showing cytotoxicity from $250{\mu}M$, steviol derivatives are not cytotoxic more than $250{\mu}M$ concentration. We have observed a change in the tight junction protein via quantitative real-time PCR. Claudin 8 among tight junction proteins is only significantly reduced up to 30% in the presence of steviol. In addition, cell migration was inhibited by steviol, not by stevioside and rebaudioside. Finally, we could observe that steviol, not stevioside and rebaudioside, is able to increase the skin barrier permeability through the transepithelial electric resistance (TEER) measurements. These results suggest that the steviol and its derivatives are specifically acts on the tight junction related gene expression, but steviol derivatives are more suitable as a cosmetic material.

Cell proliferation inhibition effects of epigallocatechin-3-gallate in TREK2-channel overexpressing cell line (TREK2-채널 과발현 세포주에서 에피갈로카테킨-3-갈레이트의 세포 증식 억제 효과)

  • Kim, Yangmi;Kim, Kyung-Ah
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.3
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    • pp.127-135
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    • 2016
  • Two-pore domain potassium (K2P) channels are the targets of physiological stimuli, such as intracellular pH, bioactive lipids, and neurotransmitters, and they set the resting membrane potential. Some types of K2P channels play a critical role in both apoptosis and tumoriogenesis. Among the K2P channels, no antagonists of the TREK2 channel have been reported. The aim of the present study was to determine if the TREK2 channel is blocked and whether cell proliferation is influenced by flavonoids in the TREK2 overexpressing HEK293 cells (HEKT2). The electrophysiological current was recorded using single channel patch clamp techniques and cell proliferation was measured using a XTT assay. The electrophysiological results showed that the TREK2 channel activity was reduced to $91.5{\pm}13.1%$ (n=5) and $82.2{\pm}13.7%$ (n=5) by flavonoids, such as epigallocatechin-3-gallate (EGCG) and quercetin in HEKT2 cells, respectively. In contrast, the EGCG analogue, epicatechin (EC), had no significant inhibitory effects on the TREK2 single channel activity. In addition, cell proliferation was reduced to $69.4{\pm}14.0%$ (n=4) by ECGG in the HEKT2 cells. From these results, EGCG and quercetin represent the first known TREK2 channel inhibitors and only EGCG reduced HEKT2 cell proliferation. This suggests that the flavonoids may work primarily by inhibiting the TREK2 channel, leading to a change in the resting membrane potential, and triggering the initiation of a change in intracellular signaling for cell proliferation. TREK2 channel may, at least in part, contribute to cell proliferation.

Antihepatotoxic effect of ethanol extracts from steam-dried ginseng berry on ᴅ-galactosamine/lipopolysaccharide-sensitized mice (ᴅ-galactosamine/lipopolysaccharide로 감작된 급성간독성 마우스 모델에서 인삼열매추출물의 간독성 개선 효과)

  • Jang, Su Kil;Park, Jun Sub;Ahn, Jeong Won;Jo, Boram;Kim, Hyun Soo;Kim, JeongHoon;Kim, Sang Yun;Park, Jung Youl;Lee, Do Ik;Park, Hee Yong;Joo, Seong Soo
    • Korean Journal of Food Science and Technology
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    • v.49 no.6
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    • pp.676-684
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    • 2017
  • The present study aimed to examine the hepatoprotective effects of ethanol extracts from steam-dried ginseng berry (SGBE) in both $\text\tiny{D}$-Galactosamine/Lipopolysaccharide ($\text\tiny{D}$-GalN/LPS)-sensitized mice and in vitro models. Our results clearly demonstrated that SGBE significantly reduced the level of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and lactate dehydrogenase in blood, and $TNF{\alpha}$ was normalized in 8 h after the treatment with $\text\tiny{D}$-GalN/LPS. Coincidently, major organs remained unimpaired when compared to $\text\tiny{D}$-GalN/LPS control group. Moreover, p38, which stimulates expression of NAFLD-associated cytokines, was markedly inhibited when treated with SGBE. In vitro analysis revealed that the main components of SGBE, linoleic acid and ginsenoside Re/Rd, may play a role in protecting liver from $\text\tiny{D}$-GalN/LPS-induced toxicity. Finally, we concluded that SGBE may be a promising therapeutic agent for preventing damage to the liver.

Combination Treatment with Arsenic Trioxide and Sulindac Induces Apoptosis of NCI-H157 Human Lung Carcinoma Cells via ROS Generation with Mitochondrial Dysfunction (NCI-H157 폐암 세포주에서 활성산소종의 생성과 미토콘드리아 기능변화를 한 Arsenic Trioxide와 Sulindac 병합요법의 세포고사효과)

  • Kim, Hak-Ryul;Yang, Sei-Hoon;Jeong, Eun-Taik
    • Tuberculosis and Respiratory Diseases
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    • v.59 no.1
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    • pp.30-38
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    • 2005
  • Background : Arsenic trioxide ($As_2O_3$) has been used to treat acute promyelocytic leukemia, and it induces apoptosis in a variety of solid tumor cell lines including non-small cell lung cancer cells. However, nonsteroidal antiinflammatory drugs (NSAID) can enhance tumor response to chemotherapeutic drugs or radiation. It was previously demonstrated that a combination treatment with $As_2O_3$ and sulindac induces the apoptosis of NCI-H157 human lung carcinoma cells by activating the caspase cascade. This study aimed to determine if a combination treatment augmented its apoptotic potential through other pathways except for the activation of the caspase cascade. Material and Methods : The NCI-H157 cells were treated with $As_2O_3$, sulindac and antioxidants such as glutathione (GSH) and N-acetylcysteine (NAC). The cell viability was measured by a MTT assay, and the level of intracellular hydrogen peroxide ($H_2O_2$) generation was monitored fluorimetrically using a scopoletin-horse radish peroxidase (HRP) assay. Western blotting and mitochondrial membrane potential transition analysis were performed in order to define the mechanical basis of apoptosis. Results : The viability of the cells was decreased by a combination treatment of $As_2O_3$ and sulindac, and the cells were protected using antioxidants in a dose-dependent manner. The increased $H_2O_2$ generation by the combination treatment was inhibited by antioxidants. The combination treatment induced changes in the mitochondrial transmembrane potential as well as the expression of the Bcl-2 family proteins, and increased cytochrome c release into the cytosol. However, the antioxidants inhibited the effects of the combination treatment. Conclusion : Combination treatment with $As_2O_3$ and sulindac induces apoptosis in NCI-H157 human lung carcinoma cells via ROS generation with a mitochondrial dysfunction.

EFFECTS OF HYDROQUINONE ON NEOPLASTIC TRANSFORMATION OF HUMAN EPITHELIAL CELLS IN CULTURE (Hydroquinone이 인체 상피세포의 발암화에 미치는 영향)

  • Sohn, Jung-Hee;Kim, Chin-Soo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.32 no.3
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    • pp.218-228
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    • 2010
  • Components of dental resin-based restorative materials are reported to leach from the filling materials even after polymerization. Hydroquinone (HQ) is one of the major monomers used in the dental resin and is known as a carcinogen. Thus, carcinogenic risk of HQ leaching from the dental resin becomes a public health concern. The present study attempted to examine the carcinogenic potentials of HQ on the human epithelial cell, which is the target cell origin of the most of oral cancers. Cytotoxicity of HQ was observed above 50${\mu}M$ as measured by LDH assay, indicating a relatively low toxicity of this substance in human epithelial cells. The parameters of neoplastic cellular transformation such as cell saturation density, soft agar colony formation and cell aggregation were analyzed to examine the carcinogenic potential of HQ. The study showed that 2-week exposure of HQ showed the tendency of increase in the saturation density and the significant enhancement of soft agar colony formation at the highest dose, 50 ${\mu}M$ only. It is suggested that HQ has a weak potential of carcinogenicity. When cells were treated with HQ and TPA, a well-known tumor promoter, the parameters of neoplastic cellular transformation was significantly increased. This result indicates that the potential risk of carcinogenicity from HQ is largely dependent upon the presence of promoter. Exposure of 50 ${\mu}M$ HQ increased the time-dependent apoptosis as measured by the ELISA kit. This concentration coincides with a dose of neoplastic transformation, indicating a possible link between apoptosis and HQ-induced cellular transformation. Hydroquinone generated Reactive Oxygen Species (ROS) which was evidenced by the treatment of antioxidants such as trolox and N-acetyl cysteine and the GSH depleting agent, BSO. Antioxidants blocked the generation of ROS and the GSH depleting agent, BSO dramatically increased the ROS production. Since HQ is known to increase ROS production thru activation of transcriptional factor such as c-Myb and Pim-1, it is speculated that ROS generation by HQ plays a role in the activation of oncogene, which may lead to neoplastic transformation. In addition, ROS is involved in the alteration of signal transduction, which regulates the apoptosis in many cellular systems. Thus, ROS-mediated apoptosis may be involved in the HQ-induced carcinogenic processes. Protein kinase C (PKC) is known to play pivotal roles in neoplastic transformation of cells and its high expression is often found in a variety of types of tumors including oral cancer. PKC translocation of PKC-${\alpha}$ was observed following HQ exposure. Altered signaling system may also play a role in the transformation process. Taken together, HQ leached from the dental resin does not pose a significant threat as a cancer causing agent, but its carcinogenic potential can be significantly elevated in the presence of promoter. The mechanism of HQ-induced carcinogenesis involved ROS generation, apoptosis and altered signaling pathway. The present study will provide a valuable data to estimate the potential risk of HQ as a carcinogen and understand mechanism of HQ-induced carcinogenesis in human epithelial cells.