• Journal of the Korean Institute of Gas
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• v.12 no.1
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• pp.7-12
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• 2008

In order to estimate the integrity and identify the dynamic characteristics of buried gas pipelines subjected to vehicle loads, FE analysis is performed based on the 'Highway and Local Road Design Criteria' and the 'KOGAS Guideline for Pipeline Management'. The FE model describes the current burial condition of Korea properly, and the DB-24 load model is adopted for this research. This study considers a varying velocity in the range of $40{\sim}160\;km/h$ and $P_i=8$ MPa(internal pressure) with depth cover, Z=1.5 m. Maximum stress occurs at v=80 km/h and decreases after v=80 km/h. The maximum induced stress by DB-24 loads is about 10 MPa. Under the design pressure, however, the analysis results show that API 5L Gr. X65 pipelines have sufficient integrity to withstand the vibration of vehicle loads.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.4
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• pp.659-665
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• 2017

Power semiconductor devices required the low on-resistance and high breakdown voltage. Wide band-gap materials opened a new technology of the power devices which promised a thin drift layer at an identical breakdown voltage. The diamond had the wide band-gap of 5.5 eV which induced the low power loss, high breakdown capability, low intrinsic carrier generation, and high operation temperature. We investigated the p-type pseudo-vertical diamond Schottky barrier diodes using a numerical simulation. The impact ionization rate was material to calculating the breakdown voltage. We revised the impact ionization rate of the diamond for adjusting the parallel-plane breakdown field at 10 MV/cm. Effects of the field plate on the breakdown voltage was also analyzed. A conventional diamond Schottky barrier diode without field plate exhibited the high forward current of 0.52 A/mm and low on-resistance of $1.71{\Omega}-mm$ at the forward voltage of 2 V. The simulated breakdown field of the conventional device was 13.3 MV/cm. The breakdown voltage of the conventional device and proposed devices with the $SiO_2$ passivation layer, anode field plate (AFP), and cathode field plate (CFP) was 680, 810, 810, and 1020 V, respectively. The AFP cannot alleviate the concentration of the electric field at the cathode edge. The CFP increased the breakdown voltage with evidences of the electric field and potential. However, we should consider the dielectric breakdown because the ideal breakdown field of the diamond is higher than that of the $SiO_2$, which is widely used as the passivation layer. The real breakdown voltage of the device with CFP decreased from 1020 to 565 V due to the dielectric breakdown.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.4
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• pp.30-37
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• 2002

This paper reports on the results of weathering test, tracking test and salt-fog test of various kinds of cycloaliphatic epoxy systems. UV irradiation dramatically induced the loss of surface hydrophobicity due to the chain scission attack at the surface under UV irradiation. It could be seen that samples containing an UV absorbent/antioxidant and a silicone oil additive have a good performance in weathering test, while ATH(alumina tri-hydrate) filled ones have high resistance against tracking failure than others. Under salt fog chamber test, specimens mixed with silicone oil are able to suppress leakage current development. It was thought that silicone oil mixed into cycloaliphatic epoxy system could lead to lower the surface energy and to retain hydrophobic properties for a long time, which are desirable for outdoor use.

• Journal of the Korean Home Economics Association
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• v.47 no.1
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• pp.45-54
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• 2009

The purpose of the study is to examine the characteristics of the ideal housing for the modern family suggested by the Home Exposition (September, 1915) under the Japanese colonial rule in the macroscopic context of social change and the microscopic context of family. Through this research, we expect to have a partial understanding not only of changes in the outward appearance of traditional housing spaces during the civilization period and the early Japanese colonial rule when foreign cultures began to be introduced but also of families'residential lives and the patterns of change in people's consciousness of housing. Major conclusions from the current analysis are as follows. First, there were some changes in family paradigm induced through a home exhibition. Second, the most important factor for an ideal housing was that it must be the source of harmonic and healthy family life. Third, the importance of an appropriate space norm should be emphasized by providing the minimum size of each room. Fourth, the significance of the housing values of the economy, convenience, and hygiene should be emphasized for the ideal housing. Lastly, it was implied that for an ideal housing, the social and psychological aspects of housing must be satisfied along with the physical aspects. The limitation was that the model of ideal family housing presented in the Home Exposition cannot exclude the characteristics of the colonial perspectives in that it was followed by the model for the Japanese families.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.73-80
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• 2016

Colorectal cancer is a very prevalent diagnosed cancer. The current study was performed in order to examine the role of BRAE (Basella rubra aqueous extract) in regulating aberrant crypt foci (ACF) formation, cell proliferation and inhibition of apoptosis in a colon carcinogenesis model in male Wistar rats. Rats were randomly allocated into six groups. Group I served as control, and group II acted as a drug control administered BRAE (250mg/kg b.w.) orally for 30 weeks. Rats in group III-VI were given subcutaneous injections of DMH (25mg/kg b.w. weekly) for 15 weeks to initiate colon carcinogenesis. Those in group IV and VI were administered BRAE along with DMH injections. Rats in group V were administered with BRAE after cessation of DMH injection. After 30 weeks of experimental period colons were obtained from experimental groups and analyzed for ACF incidence, argyrophilic nucleolar organizing region-associated proteins (AgNOR) count, histopathological and immunohistochemical changes. Only in DMH exposed groups were ACF and AgNOR numbers increased. Administration of BRAE appreciably decreased the numbers of ACF and AgNOR in BRAE treated groups. Histopathological findings revealed a high level of dysplastic changes with decreased number of goblet cells found only in only DMH injected rats. Administration of BRAE in treated group rats reversed these changes. Expression markers for cell proliferation (PCNA and Ki67) were elevated in DMH treated rats, but reduced with BRAE treatement. This expression was reversed with apoptosis markers (p53 and Caspase-3). Thus the results results of the present study were found to be significant and confirmed the potential efficacy of BRAE against colon carcinogenesis.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5645-5650
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• 2013

Src homology 2 domain containing (SHC) is a proto-oncogene which mediates cell proliferation and carcinogenesis in human carcinomas. Here, the SHC SH2-domain binding protein 1 (SHCBP1) was first established to be up-regulated in human hepatocellular carcinoma (HCC) tissues by array-base comparative genome hybridization (aCGH). Meanwhile, we examine and verify it by quantitative real-time PCR and western blot. Our current data show that SHCBP1 was up-regulated in HCC tissues. Overexpression of SHCBP1 could significantly promote HCC cell proliferation, survival and colony formation in HCC cell lines. Furthermore, knockdown of SHCBP1 induced cell cycle delay and suppressed cell proliferation. Furthermore, SHCBP1 could regulate the expression of activate extracellular signal-regulated kinase 1/2 (ERK1/2) and cyclin D1. Together, our findings indicate that SHCBP1 may contribute to human hepatocellular carcinoma by promoting cell proliferation and may serve as a molecular target of cancer therapy.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.6089-6094
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• 2013

Berberine, a common isoquinoline alkaloid, has been shown to possess anti-cancer activities. However, the underlying molecular mechanisms are still not completely understood. In the current study, we investigated the effects of berberine on cell growth, colony formation, cell cycle distribution, and whether it improved the anticancer efficiency of cisplatin and doxorubicin in human breast cancer estrogen receptor positive (ER+) MCF-7 cells and estrogen receptor negative (ER-) MDA-MB-231 cells. Notably, berberine treatment significantly inhibited cell growth and colony formation in the two cell lines, berberine in combination with cisplatin exerting synergistic growth inhibitory effects. Accompanied by decreased growth, berberine induced G1 phase arrest in MCF-7 but not MDA-MB-231 cells. To provide a more detailed understanding of the mechanisms of action of berberine, we performed genome-wide expression profiling of berberine-treated cells using cDNA microarrays. This revealed that there were 3,397 and 2,706 genes regulated by berberine in MCF-7 and MDA-MB-231 cells, respectively. Fene oncology (GO) analysis identified that many of the target genes were involved in regulation of the cell cycle, cell migration, apoptosis, and drug responses. To confirm the microarray data, qPCR analysis was conducted for 10 selected genes based on previously reported associations with breast cancer and GO analysis. In conclusion, berberine exhibits inhibitory effects on breast cancer cells proliferation, which is likely mediated by alteration of gene expression profiles.

• Journal of Yeungnam Medical Science
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• v.17 no.1
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• pp.12-20
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• 2000

The memory of pain can be more damaging than its initial experience. Several factors arc related the directions of pain memory: current pain intensity, emotion, expectation of pain, and peak intensity of previous pain. The possible mechanisms behind the memory of pain are neuroplastic changes of nervous system via peripheral and central sensitization. Peripheral sensitization is induced by neurohumoral alterations at the site of injury and nearby. Biochemicals such as K+, prostaglandins, bradykinin, substance P, histamine and serotonin, increase transduction and produce continuous nociceptive input. Central sensitization takes place within the dorsal horn of spinal cord and amplifies the nociceptive input from the periphery. The mechanisms of central sensitization involve a variety of transmitters and postsynaptic mechanisms resulting from the activations of NMDA receptors by glutamate. and activation of NK-1 tachykinnin receptors by substance-P and neurokinnin. The clinical result of peripheral and central sensitization is hyperalgesia, allodynia, spontaneous pain, referred pain, or sympathetically maintained pain. These persistent sensory responses to noxious stimuli arc a form of memory. The hypothesis of preemptive analgesia is that analgesia administered before the painful stimulus will prevent or reduce subsequent pain and analgesic requirements in comparison to the identical analgesic intervention administered after the painful stimulus, by preventing or reducing the memory of pain in the nervous system. Conventionally, pain management was initiated following noxious stimuli such as surgery. More recently, however many have endorsed preemptive analgesia initiated before surgery. Treatments to control postsurgical pain are often best started before injury activates peripheral nociceptors and triggers central sensitization. Such preemption is not achieved solely by regional anesthesia and drug therapy but also requires behavioral interventions to decrease anxiety or stress. Although the benefit of preemptive analgesia may not be obvious in every circumstance, and in many cases may not sufficient to abolish central sensitization, it is an appropriate and human goal of clinical practice.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1993-1998
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• 2016

The effects of carbon-ion irradiation on cancer cell telomere function have not been comprehensively studied. In our previous report cancer cells with telomere dysfunction were more sensitive to carbon-ion irradiation, but the underlying mechanisms remained unclear. Here we found that telomerase activity was suppressed by carbon-ion irradiation via hTERT down-regulation. Inhibition of telomere activity by MST-312 further increased cancer cell radiosensitivity to carbon-ion radiation. hTERT suppression caused by either carbon-ion irradiation or MST-312 impaired mitochondrial function, as indicated by decreased membrane potential, mtDNA copy number, mitochondrial mass, total ATP levels and elevated reactive oxygen species (ROS). PGC-$1{\alpha}$ expression was repressed after carbion-ion irradiation, and hTERT inhibition by MST-312 could further exacerbate this effect. Lowering the mitochondrial ROS level by MitoTEMPO could partially counteract the induction of cellular senescence induced by carbon-ion radiation and MST-312 incubation. Taken together, the current data suggest that telomere-mitochondrion links play a role in the induction of senescence in MCF-7 cells after carbon-ion irradiation.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1947-1959
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• 2016

Background: Colorectal cancer (CRC) is a major cause of morbidity and mortality, being the second most common type of cancer worldwide in both men and women. It accounts yearly for approximately 9% of all new cases of cancers. Furthermore, the current chemotherapeutic regimens seem unsatisfactory, so that exploration of novel therapeutic modalities is needed. The present study was undertaken to investigate the inhibitory effects of a crude alkaloid extract (CAERS) of a medicinal herb, Rhazya stricta, on proliferation of CRC HCT116 cells and to elucidate mechanisms of action. To achieve these aims, we utilized MTT, comet, DNA laddering and gene reporter assays, along with Western blot and RT-PCR analyses. Results: We found that CAERS inhibited cell proliferation and induced apoptotic cell death in HCT116 cells. Hallmarks of morphological and biochemical signs of apoptosis were clearly evident. CAERS down-regulated DNA-binding and transcriptional activities of NF-${\kappa}B$ and AP-1 proteins, while up-regulating expression of the Nrf-2 protein. It also down-regulated expression levels of the ERK MAPK, Bcl-2, cyclin D1, CDK-4, survivin and VEGF and up-regulated levels of Bax, caspase-3/7 and -9, p53, p21, Nrf-2. Markedly, it promoted mRNA expression levels of cytoprotective genes including the hemeoxygenase-1, NAD(P)H quinine oxidoreductase 1 and UDP-glucuronyltransferase. Conclusions: These findings indicate that CAERS exerts antiproliferative action on CRC cells through induction of apoptotic mechanisms, and suggest CAERS could be a promising agent for studying and developing novel chemotherapeutic agents aimed at novel molecular targets for the treatment of CRC.