• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.86-90
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• 2001

Modified coaxial-slot antenna for minimally invasive microwave thermal therapy for liver tumor is studied in this paper. Minimally invasive microwave antenna in medicine are applied for hyperthermia for medical treatment for cancer, cardiac catheter ablation for ventricular arrhythmias treatments, microwave treatment of Benign prostatic hypertrophy, and so on. Microwave hyperthermal ablation for liver tumors is expected for enthusiasts as an alternative to curative surgical resection. Tumors have to heated up to 60 degree C to coagulate .cancer cells but less than 100 degree C to avoid evaporation. Temperature dependence of properties of the tissues should be considered for wide range of treatment. Electrical properties of liver tissue were measured for different temperatures. SAR distribution around the antenna into the liver are simulated using Remcom's XFDTD.

• Journal of the Institute of Convergence Signal Processing
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• v.23 no.4
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• pp.256-263
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• 2022

Skin cancer is one of the most common diseases in the world, and the incidence rate in Korea has increased by about 100% over the past five years. In the United States, more than 5 million people are diagnosed with skin cancer every year. Skin cancer mainly occurs when skin tissue is damaged for a long time due to exposure to ultraviolet rays. Melanoma, a malignant tumor of skin cancer, is similar in appearance to Atypical melanocytic nevus occurring on the skin, making it difficult for the general public to be aware of it unless secondary signs occur. In this paper, we propose a skin cancer lesion edge detection algorithm and a deep learning model, CRNN, which performs skin cancer lesion classification for early detection and classification of these skin cancers. As a result of the experiment, when using the contour detection algorithm proposed in this paper, the classification accuracy was the highest at 97%. For the Canny algorithm, 78% was shown, 55% for Sobel, and 46% for Laplacian.

• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.843-852
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• 2019

In the present study, we established a comprehensive dataset of dose coefficients (DCs) of the new meshtype ICRP reference computational phantoms (MRCPs) for idealized external exposures of photons and electrons with the Geant4 code. Subsequently, the DCs for the nine organs/tissues, calculated for their thin radiosensitive target regions, were compared with the values calculated by averaging the absorbed doses over the entire organ/tissue regions to observe the influence of the thin sensitive regions on dose calculations. The result showed that the influences for both photons and electrons were generally insignificant for the majority of organs/tissues, but very large for the skin and eye lens, especially for electrons. Furthermore, the large influence for the skin eventually affected the effective dose calculations for electrons. The DCs of the MRCPs also were compared with the current ICRP-116 values produced with the current ICRP-110 reference phantoms. The result showed that the DCs for the majority of organs/ tissues and effective dose were generally similar to the ICRP-116 values for photons, except for very low energies; however, for electrons, significant differences from the ICRP-116 values were found in the DCs, particularly for superficial organs/tissues and skeletal tissues, and also for effective dose.

• Journal of the Optical Society of Korea
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• v.11 no.1
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• pp.26-33
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• 2007

We demonstrate the capability of differential-phase optical coherence tomography (DP-OCT) to detect superparamagnetic iron oxide (SPIO) nanoparticles taken up by liver parenchymeal macrophages (Kupffer cells). We apply an external time-varying high-intensity focused magnetic field. Our experiments demonstrate a novel diagnostic modality to detect macrophages that have taken up SPIO nanoparticles. Magnetic force acting on the nanoparticles was varied by applying a sinusoidal current to a solenoid containing a conical iron core that substantially increased and focused the magnetic field strength ($B_{max}$ = 2 Tesla). $ApoE^{-/-}$ mice were sacrificed 2 days post intravenous injections of different SPIO doses (1.0, and 0.1 mmol Fe/kg body weight). Livers of $ApoE^{-/-}$ mice with and without injection of SPIO nanoparticles were investigated using DP-OCT, which detects tissue movement with nanometer resolution. Frequency response of iron-laden liver movement was twice the stimulus frequency. Movement was not observed in livers of control mice. Results of our experiments indicate DP-OCT is a candidate methodology to detect tissue based macrophages containing SPIO nanoparticles excited by an external focused magnetic field.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.571-578
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• 2015

Prostate cancer is the most common cancer in men. In this study, we investigated immune responses of cytotoxic T lymphocytes (CTLs) against TRAMP-C2 prostate cancer cells after activation by dendritic cells (DCs) loaded with TRAMP-C2 freeze-thaw antigen and/or PEP-3 peptide in vitro. Bone marrow-derived DC from the bone marrow of the C57BL/6 were induced to mature by using the cytokine of rhGM-CSF and rhIL-4, and loaded with either the freeze-thaw antigen or PEP-3 peptide or both of them. Maturation of DCs was detected by flow cytometry. The killing efficiency of the CTLs on TRAMP-C2 cells were detected by flow cytometry, CCK8, colony formation, transwell migration, and wound-healing assay. The levels of the IFN-${\gamma}$, TNF-${\beta}$ and IL-12 were measured by enzyme-linked immunosorbent assay (ELISA). Compared with the unloaded DCs, the loaded DCs had significantly increased expression of several phenotypes related to DC maturation. CTLs activated by DCs loaded with freeze-thaw antigen and PEP-3 peptide had more evident cytotoxicity against TRAMP-C2 cells in vitro. The secretion levels of IFN-${\gamma}$, TNF-${\beta}$ and IL-12, secreted by DCs loaded with antigen and PEP-3 and interaction with T cells, were higher than in the other groups. Our results suggest that the CTLs activated by DCs loaded with TRAMP-C2 freeze-thaw antigen and PEP-3 peptide exert a remarkable killing efficiency against TRAMP-C2 cells in vitro.

• Applied Microscopy
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• v.40 no.3
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• pp.133-138
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• 2010

Mountain ginseng is a perennial crop rarely found in the deep mountains of Korea. The medicinal effect of the mountain ginseng is well known as a panacea in traditional Chinese medicine for a long time. But scientific studies to elucidate the medicinal effect of the mountain ginseng have never been made on account of lack of sample. Recently an improved method of adventitious root culture system through the use of bioreactor has been developed in Panax ginseng that seems to be a reliable way of commercialization of root derived secondary metabolites. This experiment was conducted to evaluated chemotherapeutic effect against human cervical cancer cells by cisplatin (CDDP) and extract of tissue cultured mountain ginseng (ETCMG). CDDP and ETCMG-induced apoptotic cell death in human cervical cancer cell line, HeLa was confirmed by the analysis of cell growth, morphological changes, DNA fragmentation, flow cytometry showed that ETCMG is an inducer of apoptosis and synergizes with CDDP. These results suggest that ETCMG present evidence of anticancer effect and could have a possibly natural therapeutic potential in cervical cancer patients.

• Nuclear Engineering and Technology
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• v.52 no.7
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• pp.1545-1556
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• 2020

Recently, the International Commission on Radiological Protection (ICRP) has developed the Mesh-type Reference Computational Phantoms (MRCPs) for adult male and female to overcome the limitations of the current Voxel-type Reference Computational Phantoms (VRCPs) described in ICRP Publication 110 due to the limited voxel resolutions and the nature of voxel geometry. In our previous study, the MRCPs were used to calculate the dose coefficients (DCs) for idealized external exposures of photons and electrons. The present study is an extension of the previous study to include three additional particles (i.e., neutrons, protons, and helium ions) into the DC library by conducting Monte Carlo radiation transport simulations with the Geant4 code. The calculated MRCP DCs were compared with the reference DCs of ICRP Publication 116 which are based on the VRCPs, to appreciate the impact of the new reference phantoms on the DC values. We found that the MRCP DCs of organ/tissue doses and effective doses were generally similar to the ICRP-116 DCs for neutrons, whereas there were significant DC differences up to several orders of magnitude for protons and helium ions due mainly to the improved representation of the detailed anatomical structures in the MRCPs over the VRCPs.

• BMB Reports
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• v.51 no.9
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• pp.474-479
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• 2018

Cisplatin is one of the most effective chemotherapeutic drugs used in the treatment of HCC, but many patients will ultimately relapse with cisplatin-resistant disease. Used in combination with cisplatin, resveratrol has synergistic effect of increasing chemosensitivity of cisplatin in various cancer cells. However, the mechanisms of resveratrol enhancing cisplatin-induced toxicity have not been well characterized. Our study showed that resveratrol enhances cisplatin toxicity in human hepatoma cells via an apoptosis-dependent mechanism. Further studies reveal that resveratrol decreases the absorption of glutamine and glutathione content by reducing the expression of glutamine transporter ASCT2. Flow cytometric analyses demonstrate that resveratrol and cisplatin combined treatment leads to a significant increase in ROS production compared to resveratrol or cisplatin treated hepatoma cells alone. Phosphorylated H2AX (${\gamma}H2AX$) foci assay demonstrate that both resveratrol and cisplatin treatment result in a significant increase of ${\gamma}H2AX$ foci in hepatoma cells, and the resveratrol and cisplatin combined treatment results in much more ${\gamma}H2AX$ foci formation than either resveratrol or cisplatin treatment alone. Furthermore, our studies show that over-expression of ASCT2 can attenuate cisplatin-induced ROS production, ${\gamma}H2AX$ foci formation and apoptosis in human hepatoma cells. Collectively, our studies suggest resveratrol may sensitize human hepatoma cells to cisplatin chemotherapy via gluta${\gamma}H2AX$mine metabolism inhibition.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.4
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• pp.368-373
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• 2009

A human tissue mimicking phantom is constructed to assess the performance of a medical ultrasound elasticity imaging system. In a human body, the tumor or cancer is stiffer than its surrounding normal tissue. A technique fur imaging the elasticity of such a tissue is referred to as elastography. Homogeneous elasticity phantoms with differing Young's moduli are constructed using a plastic hardener and softener to simulate the mechanical characteristics of a diseased human tissue. The Young's modulus of the fabricated homogeneous phantom materials were measured from 11.1 to 79.6 kPa depending on the mixing ratio of the amount of the hardener to that of the softener. An ultrasound lesion mimicking phantom was made of these materials, and ultrasound elasticity imaging was performed on it. It is confirmed in this paper that the fabricated plastic-based elasticity phantom is useful in representing the elastic characteristics of a human tissue.

• Korean Journal of Pharmacognosy
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• v.40 no.1
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• pp.6-12
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• 2009

Thirty five methanol extracts from 19 natural local plants, which have been used as traditional anti-cancer medicine, were prepared. They were analyzed the cytotoxic effects on primary fibroblast cells and carcinoma cells. The root extract of Solanum nigrum were highly toxic in both cell lines with $IC_{50}$ values of less than $0.01{\mu}g/{\mu}l$, and 26 of 35 extracts were toxic in all cells with $IC_{50}$ values of $0.1{\sim}2{\mu}g/{\mu}l$. Three extracts including the fruit extracts of Solanum nigrum and Morus alba had no cytotoxic activity in both cell lines. Five of 35 extracts were highly toxic in cancer cells than in primary cells. Because primary cells were more resistant on these extracts, the five extracts were selected for anti-cancer agent candidates. Apoptosis or programmed cell death has an essential role in chemotherapy-induced tumor cell killing. Recently, inducers of apoptosis have been used in cancer therapy. When two of 5 cancer cell-specific cytotoxic extracts (Ulmus parvifolia and Zelkova serrata) were treated in concentration of $0.02{\sim}0.1{\mu}g/{\mu}l$, apoptosis were increased at 3-5 times in cancer cell lines. Finally, the apoptotic effects of these extracts were confirmed by cleavages of both poly-(ADP-ribose)-polymerase and caspase-3 as apoptotic markers. In this report, we suggested that two of 35 medicinal herb extracts can be useful anti-cancer drug candidates inducing apoptosis in several carcinoma cell lines.