• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.114-120
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• 2020

In this study, we analyzed the structural characteristics of soot, which is one of the anticipated regulatory substances of the IMO, and used a novel classification method to distinguish between exhaust soot and engine soot in marine engines. As an extension of a recent study on exhaust soot recycling, annealing was performed at 2,000 ℃ on engine soot to determine whether it could be recycled. Soot samples before and after annealing were analyzed using HR-TEM and Raman spectroscopy. The HR-TEM results showed that exhaust soot and engine soot had similar nanostructures; the exhaust soot has a spherical primary particle with a chain-like structure, whereas engine soot particles have amorphous structures. The Raman spectroscopy showed a D-peak and a G-peak for both exhaust soot and engine soot. However, the G/D ratio indicated that the value of exhaust soot was relatively higher than that of engine soot, which implies that the exhaust soot has a more graphitized structure. The analysis of annealed engine soot confirmed that graphitization proceeded without any problems, similar to the exhaust soot. This confirmed that both exhaust soot and engine soot generated by marine diesel engines could be recycled as graphite materials.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.559-564
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• 2015

Background: The participation of women in cervical cancer screening in Malaysia is low. Self-sampling might be able to overcome this problem. The aim of this study was to assess the reliability of self-sampling for cervical smear in our country. Materials and Methods: This cross-sectional study was conducted on 258 community dwelling women from urban and rural settings who participated in health campaigns. In order to reduce the sampling bias, half of the study population performed the self-sampling prior to the physician sampling while the other half performed the self-sampling after the physician sampling, randomly. Acquired samples were assessed for cytological changes as well as HPV DNA detection. Results: The mean age of the subjects was $40.4{\pm}11.3years$. The prevalence of abnormal cervical changes was 2.7%. High risk and low risk HPV genotypes were found in 4.0% and 2.7% of the subjects, respectively. A substantial agreement was observed between self-sampling and the physician obtained sampling in cytological diagnosis (k=0.62, 95%CI=0.50, 0.74), micro-organism detection (k=0.77, 95%CI=0.66, 0.88) and detection of hormonal status (k=0.75, 95%CI=0.65, 0.85) as well as detection of high risk (k=0.77, 95%CI=0.4, 0.98) and low risk (K=0.77, 95%CI=0.50, 0.92) HPV. Menopausal state was found to be related with 8.39 times more adequate cell specimens for cytology but 0.13 times less adequate cell specimens for virological assessment. Conclusions: This study revealed that self-sampling has a good agreement with physician sampling in detecting HPV genotypes. Self-sampling can serve as a tool in HPV screening while it may be useful in detecting cytological abnormalities in Malaysia.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.7
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• pp.3035-3042
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• 2015

Background: Isorhamnetin (Iso), a novel and essential monomer derived from total flavones of Hippophae rhamnoides that has long been used as a traditional Chinese medicine for angina pectoris and acute myocardial infarction, has also shown a spectrum of antitumor activity. However, little is known about the mechanisms of action Iso on cancer cells. Objectives: To investigate the effects of Iso on A549 lung cancer cells and underlying mechanisms. Materials and Methods: A549 cells were treated with $10{\sim}320{\mu}g/ml$ Iso. Their morphological and cellular characteristics were assessed by light and electronic microscopy. Growth inhibition was analyzed by MTT, clonogenic and growth curve assays. Apoptotic characteristics of cells were determined by flow cytometry (FCM), DNA fragmentation, single cell gel electrophoresis (comet) assay, immunocytochemistry and terminal deoxynucleotidyl transferase nick end labeling (TUNEL). Tumor models were setup by transplanting Lewis lung carcinoma cells into C57BL/6 mice, and the weights and sizes of tumors were measured. Results: Iso markedly inhibited the growth of A549 cells with induction of apoptotic changes. Iso at $20{\mu}g/ml$, could induce A549 cell apoptosis, up-regulate the expression of apoptosis genes Bax, Caspase-3 and P53, and down-regulate the expression of Bcl-2, cyclinD1 and PCNA protein. The tumors in tumor-bearing mice treated with Iso were significantly smaller than in the control group. The results of apoptosis-related genes, PCNA, cyclinD1 and other protein expression levels of transplanted Lewis cells were the same as those of A549 cells in vitro. Conclusions: Iso, a natural single compound isolated from total flavones, has antiproliferative activity against lung cancer in vitro and in vivo. Its mechanisms of action may involve apoptosis of cells induced by down-regulation of oncogenes and up-regulation of apoptotic genes.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8579-8587
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• 2016

Background: The molecular mechanisms linking breast cancer progression and inflammation still remain obscure. The aim of the present study was to investigate the possible association of angiopoeitin like protein 4 (ANGPTL4) and its regulatory factor, hypoxia inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$), with the inflammatory markers nuclear factor kappa B/p65 (NF-${\kappa}B$/P65) and interleukin-1 beta (IL-$1{\beta}$) in order to evaluate their role in inflammation associated breast cancer progression. Materials and Methods: Angiopoietin-like protein 4 (ANGPTL4) mRNA expressions were evaluated using quantitative real time PCR and its protein expression by immunohistochemistry. DNA binding activity of NF-${\kappa}B$/P65 was evaluated by transcription factor binding immunoassay. Serum levels of ANGPTL4, HIF-$1{\alpha}$ and IL-$1{\beta}$ were immunoassayed. Tumor clinico-pathological features were investigated. Results: ANGPTL4 mRNA expressions and serum levels were significantly higher in high grade breast carcinoma ($1.47{\pm}0.31$ and $184.98{\pm}18.18$, respectively) compared to low grade carcinoma ($1.21{\pm}0.32$ and $171.76{\pm}7.58$, respectively) and controls ($0.70{\pm}0.02$ and $65.34{\pm}6.41$, respectively), (p<0.05). Also, ANGPTL4 high/moderate protein expression was positively correlated with tumor clinico-pathological features. In addition, serum levels of HIF-$1{\alpha}$ and IL-$1{\beta}$ as well as NF-${\kappa}B$/P65 DNA binding activity were significantly higher in high grade breast carcinoma ($148.54{\pm}14.20$, $0.79{\pm}0.03$ and $247.13{\pm}44.35$ respectively) than their values in low grade carcinoma ( $139.14{\pm}5.83$, $0.34{\pm}0.02$ and $184.23{\pm}37.75$, respectively) and controls ($33.95{\pm}3.11$, $0.11{\pm}0.02$ and $7.83{\pm}0.92$, respectively), (p<0.001). Conclusion: ANGPTL4 high serum levels and tissue expressions in advanced grade breast cancer, in addition to its positive correlation with tumor clinico-pathological features and HIF-$1{\alpha}$ could highlight its role as one of the signaling factors involved in breast cancer progression. Moreover, novel correlations were found between ANGPTL4 and the inflammatory markers, IL-$1{\beta}$ and NF-${\kappa}B$/p65, in breast cancer, which may emphasize the utility of these markers as potential tools for understanding interactions for axes of carcinogenesis and inflammation contributed for cancer progression. It is thus hoped that the findings reported here would assist in the development of new breast cancer management strategies that would promote patients' quality of life and ultimately improve clinical outcomes. However, large-scale studies are needed to verify these results.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.2
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• pp.627-633
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• 2015

Background: To study the effect of parecoxib, a novel cyclooxygenase-2 selective inhibitor, on the radiation response of colorectal cancer (CRC) cells and its underlying mechanisms. Materials and Methods: Both in vitro colony formation and apoptosis assays as well as in vivo mouse xenograft experiments were used to explore the radiosensitizing effects of parecoxib in human HCT116 and HT29 CRC cells. Results: Parecoxib sensitized CRC cells to radiation in vitro with a sensitivity enhancement ratio of 1.32 for HCT116 cells and 1.15 for HT29 cells at a surviving fraction of 0.37. This effect was partially attributable to enhanced apoptosis induction by parecoxib combined with radiation, as illustrated using an in vitro apoptosis assays. Parecoxib augmented the tumor response of HCT116 xenografts to radiation, achieving growth delay more than 20 days and an enhancement factor of 1.53. In accordance with the in vitro results, parecoxib combined with radiation resulted in less proliferation and more apoptosis in tumors than radiation alone. Radiation monotherapy decreased microvessel density (MVD) and microvessel intensity (MVI), but increased the hypoxia level in xenografts. Parecoxib did not affect MVD, but it increased MVI and attenuated hypoxia. Conclusions: Parecoxib can effectively enhance radiation sensitivity in CRC cells through direct effects on tumor cells and indirect effects on tumor vasculature.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.3
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• pp.13-20
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• 2011

In this paper, we proposed a system to raise gas safety management by using the wireless communication module and intelligent gas safety appliances. Our designed systems configure a micom-gas meter, an automatic extinguisher, sensors, and a wallpad. A micom-gas-meter monitors gas flow, gas pressure, and earthquake. An automatic fire extinguisher checks gas(combustible) leaks and temperature of $100^{\circ}C$ and $130^{\circ}C$. Sensors measure smoke and CO gas. In our novel system, a micom-gas meter cut off inner valve with warnings, an automatic fire extinguisher cut off middle valve and spray extinguishing materials, and sensors generate signals for smoke and CO when occurring gas risk. Gas safety appliances and sensors takes safety measures, and transmit those signal to a wallpad. The wallpad again transmit signal like events to a control server. Users can connect web pages for gas safety through B-ISDN and control and manage them. We hereby devised scenarios for gas safety and risk management, and demonstrated their effectiveness through experiments.

• KSBB Journal
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• v.21 no.6 s.101
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• pp.451-455
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• 2006

An efficient pilot scale (10 ton) three-stage methane fermentation system to digest food waste has been developed in this laboratory. This system consisted of three stages: semianaerobic hydrolysis, anaerobic acidogenesis and strictly anaerobic methanogenesis. From the secondary acidogenesis reactor, a novel strain KA4 responsible for alcohol fermentation was isolated and characterized. The cell was oval and its dimension was $5.5-6.5{\times}3.5-4.5\;{\mu}m$. This strain was identified as Saccharomyces cerevisiae KA4 by 26S rDNA D1/D2 rDNA sequence. Optimal culture temperature was $30-35^{\circ}C$. Cells were tolerant to 5% (v/v) ethanol concentration, however, were inhibited significantly by higher ethanol concentration up to 7%. The strain could grow well up to 50% (w/v) initial glucose concentration in the YM liquid medium, however, optimal concentration for ethanol fermentation was 10%. It could produce ethanol in a broad initial pH range from 4 to 10, and optimal pH was 6. In this condition, the strain converted 10% glucose to 7.4% ethanol during 24 hr, and ethanol yield was estimated to be 2.87 moi EtOH/mol glucose.

• Journal of the Korean Electrochemical Society
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• v.15 no.3
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• pp.181-189
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• 2012

We developed a new high-yield synthesis method of free-standing germanium nanocrystals (Ge NCs) by means of the gas-phase photolysis of tetramethyl germanium in a closed reactor using an Nd-YAG pulsed laser. Size control (5-100 nm) can be simply achieved using a quenching gas. The $Ge_{1-x}Si_x$ NCs were synthesized by the photolysis of a tetramethyl silicon gas mixture and their composition was controlled by the partial pressure of precursors. The as-grown NCs are sheathed with thin (1-2 nm) carbon layers, and well dispersed to form a stable colloidal solution. Both Ge NC and Ge-RGO hybrids exhibit excellent cycling performance and high capacity of the lithium ion battery (800 and 1100 mAh/g after 50 cycles, respectively) as promising anode materials for the development of high-performance lithium batteries. This novel synthesis method of Ge NCs is expected to contribute to expand their applications in high-performance energy conversion systems.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.22 no.1
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• pp.47-55
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• 2013

There have been a great number of developments in clinical techniques and dental materials in dentistry to date. Looking at these developments, while it could be seen that functional elements such as mastication were prioritized rather than aesthetic aspect in the past, aesthetic needs of patients have steadily increased over time and accordingly the aesthetic has become considered a priority in the development of dentistry. Although the first to be considered in discussing the aesthetic in clinical dentistry will be the white aesthetic that is the tooth part of prosthesis, the pink aesthetic that refers to the harmony of such prosthesis with gingiva can be an important consideration not to be ignored aesthetically. However, the harmony with the gingiva often cannot be obtained only by the beautiful prosthesis, and in particular, the pontic and implant areas have poor conditions to achieve the gingival (pink) aesthetic due to the absorption of alveolar ridge compared to natural teeth. Among the most important elements of the gingival aesthetic are the gingival level and the interproximal papilla height. It is very difficult to make the gingival aesthetic in the case of insufficient alveolar ridge, and the recovery of ridge volume and contour is necessary in order to overcome this condition. To this end, the most widely used method is the "connective tissue graft". Many techniques of the connective tissue graft have already been introduced for the ridge augmentation, and each technique has different purposes, and advantages and disadvantages. Rather, due to the excessive amount of techniques, there is confusion about selecting the right technique at a certain time. However, the goal is clear. Ways to increase the success rates must be found, and at the same time, a more favorable way to the gingival aesthetic is to be chosen. Thus, in this study, considerations for the gingival aesthetic that makes harmony and the techniques to achieve it are discussed.

• Imaging Science in Dentistry
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• v.39 no.1
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• pp.35-39
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• 2009

Purpose: The purpose of the experiment was to evaluating the diagnostic ability of dental caries detection using digital subtraction in the artificial caries activity model. Materials and Methods: Digital radiographies of five teeth with 8 proximal surfaces were obtained by CCD sensor (Kodak RVG 6100 using a size #2). The digital radiographic images and subtraction images from artificial proximal caries were examined and interpreted. In this study, we proposed novel caries detection method which could diagnose the dental proximal caries from single digital radiographic image. Results: In artificial caries activity model, the range of lesional depth was $572-1,374{\mu}m$ and the range of lesional area was $36.95-138.52mm^2$. The lesional depth and the area were significantly increased with demineralization time (p<0.001). Furthermore, the proximal caries detection using digital subtraction radiography showed high detection rate compared to the proximal caries examination using simple digital radiograph. Conclusion: The results demonstrated that the digital subtraction radiography from single radiographic image of artificial caries was highly efficient in the detection of dental caries compared to the data from simple digital radiograph.