• BMB Reports
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• v.35 no.4
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• pp.371-376
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• 2002

The receptor activator of nuclear factor kappa B (RANK) is a member of the tumor necrosis factor (TNF) receptor superfamily. It plays a critical role in osteoclast differentiaion, lymph node organogenesis, and mammary gland development. The stimulation of RANK causes the activation of transcription factors NF-${\kappa}B$ and activator protein 1 (AP1), and the mitogen activated protein kinase (MAPK) c-Jun N-terminal kinase (JNK). In the signal transduction of RANK, the recruitment of the adaptor molecules, TNF receptor-associated factors (TRAFs), is and initial cytoplasmic event. Recently, the association of the MAPK kinase kinase, transforming growth factor-$\beta$-activated kinase 1 (TAK1), with TRAF6 was shown to mediate the IL-1 signaling to NF-${\kappa}B$ and JNK. We investigated whether or not TAK1 plays a role in RANK signaling. A dominant-negative form of TAK1 was discovered to abolish the RANK-induced activation of AP1 and JNK. The AP1 activation by TRAF2, TRAF5, and TRAF6 was also greatly suppressed by the dominant-negative TAK1. the inhibitory effect of the TAK1 mutant on RANK-and TRAF-induced NF-${\kappa}B$ activation was also observed, but less efficiently. Our findings indicate that TAK1 is involved in the MAPK cascade and NF-${\kappa}B$ pathway that is activated by RANK.

• YAKHAK HOEJI
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• v.60 no.3
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• pp.128-134
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• 2016

L1 cell adhesion molecule (L1CAM) is a cell surface molecule to initiate a variety of cellular responses through interacting with other cell adhesion molecules in a homophilic or heterophilic manner. Although its expression was found to be upregulated in some tumor cells, including cholangiocarcinomas, and ovarian cancers, and many studies have investigated the role of L1CAM in these cancers, its role in inflammatory responses has been poorly understood. In this study, we explored the role of L1CAM in macrophage-mediated inflammatory responses. L1CAM significantly suppressed the production of nitric oxide (NO), but induced cell proliferation in RAW264.7 cells. L1CAM expression was detectable, but its expression was markedly decreased by lipopolysaccharide (LPS) in RAW264.7 cells. In addition, the expression of pro-inflammatory genes, such as tumor necrosis factor (TNF)-${\alpha}$, cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS) induced by LPS was dramatically suppressed by L1CAM in RAW264.7 cells. L1CAM inhibited the transcriptional activities of NF-${\kappa}B$ and AP-1 while its cytoplasmic domain deletion form, $L1{\Delta}CD$ did not suppressed their activities in RAW264.7 cells. Moreover, L1CAM suppressed nuclear translocation of p65 and p50 as well as c-Jun, c-Fos and p-ATF2 which are transcription factors of NF-${\kappa}B$ and AP-1, respectively. In conclusion, L1CAM suppressed inflammatory responses in macrophages through inhibiting NF-${\kappa}B$ and AP-1 pathways.

• Korean Journal of Optics and Photonics
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• v.16 no.6
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• pp.527-534
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• 2005

We investigate the pulsation characteristics in a multi-section DFB laser which is composed of one DFB section, phase tuning section, and gain section. Multi-section DFB lasers with anti-phase (AP) complex-coupled (CC) DFB structure show wide current ranges of gain and phase tuning sections fer stable pulsations compared to those with in-phase CC DFB structure or index-coupled DFB structure. For multi-section DFB lasers with AP CC DFB structure, the current range of a gain section for stable pulsations increases and the tuning range of the pulsation frequency increases as a coupling strength or a gain coupling coefficient increases Also, the tuning range using the phase variation in a phase tuning section increases. For a fixed coupling strength, the current ranges of gain and phase tuning sections for stable pulsations increase and the tuning range of the pulsation frequency increases as the length of a DFB section increases.

• Investigative Magnetic Resonance Imaging
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• v.20 no.4
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• pp.241-249
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• 2016

Purpose: To evaluate the added value of diffusion weighted imaging (DWI) to computed tomography (CT) for detecting pancreatic abnormality in patients with clinically suspected acute pancreatitis (AP). Materials and Methods: 203 patients who underwent abdomen CT and subsequent DWI to do a workup for epigastric pain were analyzed. Two blinded radiologists independently performed an interval reading based on CT image sets first, then based on combined CT and DWI image sets. The diagnostic criterion on DWI was the increased signal intensity in the pancreas to that of the spleen. For quantitative analysis, the third radiologist measured ADC value of the pancreas in each patient. Results: For AP (n = 43), the sensitivity for detecting pancreatic abnormality increased, from 42% to 70% for reader 1 (P < 0.05) and from 44% to 72% for reader 2 (P < 0.05). For borderline pancreatitis (n = 42), the sensitivity also increased, from 10% to 26% for reader 1 (P < 0.05) and from 7% to 29% for reader 2 (P < 0.05). The mean ADC values (unit, ${\times}10^{-3}mm^2/s$) were significantly different among the three groups (for AP, $1.09{\pm}0.16$; for borderline pancreatitis, $1.28{\pm}0.2$; for control, $1.46{\pm}0.15$, P < 0.05). Conclusion: Sensitivity for detecting pancreatic abnormality increased significantly after adding DWI to CT in patients with clinically suspected AP.

• Journal of the Korea Society of Computer and Information
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• v.20 no.2
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• pp.89-97
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• 2015

In this paper, we propose a handoff method supporting LBS (Location Based Services) Information in mobile clouding environment. In mobile clouding computing, handoff delay and re-authentication is occurred. A mobile node needs re-authentication procedure from cloud server whenever it arrives new AP. But Using of location information of node enables to reduce delay time due to re-authentication. To reduce re-authentication delay time, proposed method stores location information of APs on WiFi based location server to complement. GPS-based technology which can't receive satellite signal in indoor and then node collects location information of AP at handoff time. And also enables to process LBS without increasing handoff delay by splitting the process of handoff from process of requesting location information. For analysis of proposed method, We analyze handoff delay and location information process time and have compared previous handoff method in cloud environment. We confirmed that proposed method shows lower delay time without increasing LBS process time than previous method because node receives location information from location information server when handoff is occurred.

• The KIPS Transactions:PartC
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• v.18C no.3
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• pp.187-194
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• 2011

IEEE 802.11 wireless LAN has become the center of attention for one of the most dominant wireless networking technologies nowadays. In densely deployed wireless LANs, mobile stations are exposed to a number of AP, thus it is needed to select the best AP to associate with. The most common approach is to select the AP with the highest received signal strength. However it does not consider traffic load imposed to each AP so that it may cause the poor network performance. Therefore, in this paper, we propose a throughput estimation scheme for neighboring APs by sniffing the traffic within 802.11 networks. We devise a tool, named "VirtFrame", which is to estimate the station's capable throughput from neighbor APs based on the channel access time by virtually combining the sniffed frames. Simulation results show that our proposed scheme well matches that there exists correlation between the channel access time and the actual throughput of the APs.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.372-377
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• 2014

Being able to monitor the heart will allow the diagnosis of heart diseases for patients during daily activities, and the detection of burden on the heart during strenuous exercise. Furthermore, with the help of U-health technology, immediate medical action can be taken, in the case of abnormal symptoms of the heart in daily life. Therefore, it appears to be necessary to develop the corresponding technology to monitor the condition of the heart daily. In this study, a novel wearable smart system was proposed, to monitor the activity of the heart in daily life, and to further evaluate the rhythm of arrhythmia. The wearable system includes three modified bipolar conductive fiber electrodes in the chest part, which can resolve the reduction problem of the magnitude of the signal, by magnifying the signal and removing the noise, to obtain high affinity and validity for medical-type usage (<0.903%). The biological signal acquisition and data lines, and the signal processing engine and communication consist of a conductive ink, and the pic18 and ANT protocol nRF24AP2, respectively. The proposed algorithm was able to detect a strong ECG, signal and r-point passing over the noise. The confidence intervals were 96 %, which could satisfy the requirement to detect arrhythmia under the unconstrained conditions.

• Journal of Korean Society for Geospatial Information Science
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• v.25 no.2
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• pp.31-37
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• 2017

Recently, governmental authority and local government are looking for a method of utilizing location information of smart phone for urgent rescue in fire and kidnap situation. Under this background, in this study, a method of rapidly collecting, constructing location determination based Wi-Fi AP data utilizing location information of smart phone and mobile mapping system was suggested in order to construct precise positioning information that could be utilized under urgent situation. By performing compensation work for GPS/INS/DMI through collected outcome, position of collected vehicle was acquired. In addition, source data integrating Wi-Fi information and collected position by coupling based on Wi-Fi AP collector and GPS time was constructed and Wi-Fi radiomap was constructed by removing Wi-Fi signal noise that reduces precise position performance. As a result of performing location determination performance assess ment by selecting 10 test positions by each local government, result value of 25.46cm for total local government average and 27.76m for SD could be obtained. It is considered that this result could be utilized as a technology of being able to supplement or substituting GPS location determination technology that is impossible in plocation determination of mobile communication company's base station (200m~2km) and indoor being used at present.

• Proceedings of the Korean Biophysical Society Conference
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• 2001.06a
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• pp.23-23
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• 2001

To evaluate the contribution of cAMP/PKA signal pathway in short-term facilitation, we overexpressed Ap oal receptor in sensory neurons that do not normally express this receptor. We have previously shown that activation of this receptor in sensory cells, by a brief treatment with octopamine (OA), produced short-term facilitation such as membrane depolarization, increase in membrane excitability, spike broadening, and enhanced neurotransmitter release in non-depressed synapse.(omitted)

• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.325-332
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• 2020

Methyl linderone (ML), a cyclo-pentenedione, was isolated from the fruit of Lindera erythrocarpa Makino (family Lauraceae). This plant has well-known anti-inflammatory effects; however, the anti-cancer effects of ML have not yet been reported. Thus, in the present study we investigated the effects of ML on the metastasis of human breast cancer cells. We used 12-O-tetradecanoyl phorbol-13-acetate (TPA)-stimulated MCF-7 cells as the cell model to study the effects of ML on invasion and migration. ML was found to reduce the invasion and migration rate of TPA-stimulated MCF-7 cells. Moreover, it inhibited two metastasis-related factors, matrix metalloproteinase-9 (MMP-9) and interleukin-8 (IL-8), at the mRNA and protein expression levels, in TPA-treated MCF-7 cells. The mechanism by which ML exerted these effects was through the inhibition of translocation of activator protein-1 (AP-1) and signal transducer and activator of transcription-3 (STAT3), mediated via phosphorylation of extracellular signal-regulated kinase (ERK). Taken together, our findings indicated that ML attenuated the TPA-stimulated invasion and migration of MCF-7 cells by suppressing the phosphorylation of ERK and its downstream factors, AP-1 and STAT3. Therefore, ML is a potential agent for the treatment of breast cancer metastasis.