• Korean Journal of Environmental Biology
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• v.29 no.3
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• pp.236-240
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• 2011

Mercury known as quicksilver, is the most common cause of heavy metal toxicity. Toxicity caused by excessive mercury exposure is now being recognized as a widespread environmental problem and is continuing to attract a great deal of public concerns. The mercury genotoxicity could be its effect on DNA repair mechanisms, which constitute the defense system designated to protect genome integrity. The objective of this study is to confirm that mercuric chloride inhibits the repair of gamma ray-induced DNA damage. The earthworm of Eisenia fetida was chosen for this study because it is an internationally accepted model species for toxicity testing with a cosmopolitan distribution. Experiments were done to identify the levels of DNA damage and the repair kinetics in the coelomocytes of E. fetida irradiated with 20 Gy gamma rays alone or with gamma rays after 40 mg $kg^{-1}$ $HgCl_2$ treatment by means of the single cell gel electrophoresis assay. The Olive tail moments were measured during 0~96 hours after irradiation. The repair time in the animals treated with the combination of $HgCl_2$ and ionizing radiation was nearly five times longer than that in the animals treated with ionizing radiation alone. Also, E. fetida exposed to mercury showed a statistically lower repair efficiency of gamma ray-induced DNA damage. The results suggest that the mercury could even have deleterious effects on the DNA repair system. Influence of mercury on the DNA repair mechanisms has been confirmed by this study.

• Journal of Ginseng Research
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• v.32 no.1
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• pp.39-47
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• 2008

UV irradiation causes skin-aging involving coarse wrinkles, thickening, dyspigmentation, and rough skin surface. These phenomena in complex skin tissue is controlled with receptor of cell surface growth factor and cytokine receptors. The activation of receptors induces multiple downstream signaling pathways including expression of MMPs (matrix metalloproteinases). This study was aimed to elucidate the mechanism for anti-wrinkle activity of Korean red ginseng, Torilis fructus and Corni fructus mixture (KTNG0345). In this animal study, we have investigated decreasing effects of Korean red ginseng mixture on MMP-3 synthesis through diminishing $TNF-{\alpha}$ signaling that express MMP-1, -3, and -9. c-Jun and c-fos as a component of transcription factor AP-1 (activator protein-1) were analyzed the expression level using real time PCR and western blotting. c-Jun was decreased dose dependent manner both gene and protein level where as cfos was not changed. In upstream, JNK and PAK was not changed, but p38 was decreased in down stream. MMP-3, final product in this pathway was significantly decreased in dose dependent manner. These results suggest that Korean red ginseng mixture have a anti-wrinkle activity through $TNF-{\alpha}$ mediated MMPs expression pathway.

• Radiation Oncology Journal
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• v.13 no.1
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• pp.55-61
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• 1995

Purpose : Despite a development of therapeutic machines and advance in modern radiation therapy techniques, locally advanced cervical carcinoma has shown high rate of local failure and poor survival rate, Combination of chemotherapy and radiotherapy demonstrated benefit in improving local control and possibly the overall survival. Our study was performed to evaluate effect of concurrent chemoradiation on locally advanced uterine cervical cancer. Methods and Materials : Twenty six patients with locally advanced stage(FIGO stage IIB with ${\geq}5cm$ in diameter, III, IVA) were treated with combination of radiation therapy and concurrent cisplatinum between May of 1988 and September of 1993 at our hospital. Radiation therapy consisted of external irradiaton and 1-2 sessions of intracavitary irradiation. Cisplatinum was administered in bolus injection of 25mg/$m^2$ at weekly intervals during the course of external radiation therapy. Results : Of the 26 Patients, twenty-five patients were evaluable for estimation of response. Median follow-up period was 25 months with ranges from 3 to 73 months. Stage IIB, III, and IVA were 16, 5, 4 patients, respectively, Twenty patients were squamous cell carcinoma. Response was noted in all 25 patients: complete response(CR) in 17/25($68\%$), Partial response(PR) in 8/25($32\%$). Of the 24 patients except one who died of sepsis at 3 months follow-up, seventeen patients($70.8\%$) maintained local control in the pelvis: 16/17($94.1\%$) in CR, 1/17($14.3\%$) in PR. Fourteen of the 17 patients with CR are alive disease free on the completion of follow-up. Median survival is 28 months for CR and 15 months for PR. Analysis of 5-year survival by stage shows 11/16($59.8\%$) in IIB, 3/5($60.0\%$) in III, and 1/4($25.0\%$) in IVA. Overall 5-year survival rate was $55.2\%$. Ten patients recurred: 4 at locoregional, 3 in distant metastasis and 3 with locoregional and distant site. Toxicity by addition of cisplatinum was not excessive. Conclusion : Although the result of this study was obtained from small number of patients, it is rather encouraging in view of markedly improved response rate compared with the results of historical group.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.3
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• pp.233-241
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• 2012

Photodynamic therapy (PDT) is a technique that involves the activation of photosensitizer by light in the presence of tissue oxygen, resulting in the production of reactive radicals capable of inducing cell death. The aim of this study was to evaluate the effect of PDT on Streptococcus mutans in planktonic conditions, previously treated with different photosensitive concentrations of erythrosine, using halogen and LED curing unit as a light source. And we compared the effects of PDT on six strains of S. mutans isolated from oral cavity and reference strain. As a result, S. mutans was susceptible to the combination of hand held photopolymerizer (HHP) and erythrosine. The higher concentration of erythrosine in the presence of light irradiation induced greater effects in reduction of viability of S. mutans. Isolated S. mutans showed a significant reduction in bacterial counts of the groups submitted to PDT compared to the control groups. And they appeared to be similar or slightly lower antimicrobial effect compared with reference strain. However, the difference was not significant (p < 0.05). In conclusion, PDT using erythrosine as a photosensitizing agent and HHP as a light source could be an efficient option for diseases caused by S. mutans.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.805-812
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• 2010

DNA damage including base modifications, loss of base and breaks in DNA strands can occur by exposure to irradiation, smoking and several components of food. Unrepaired DNA damage is known to lead to cellular dysfunction, cell death, cancer, and other diseases such as arteriosclerosis and diabetes. The protective effect of garlic on oxidative stress induced DNA damage has been reported recently. In this study, we investigated the protective effect of garlic extracts prepared by different processing methods (raw garlic extracts, RGE; grilled garlic extracts, GGE; pickled garlic extracts, PGE) on leukocytic DNA damage using comet assay. Human leukocytes were incubated with ethanol and methanol extract of garlic at various concentrations (1, 5, 10, 50 ${\mu}g$/mL), followed by oxidative stimuli (200 ${\mu}M$ $H_2O_2$ or 200 ${\mu}M$ 4-hydroxynonenal (HNE)). The methanol and ethanol extracts of RGE, GGE, and PGE showed inhibitory activities of DNA damage induced by $H_2O_2$ or HNE. Especially methanol extract of RGE ($ED_{50}$; 13.3 ${\mu}g$/mL) had a higher antigenotoxic effect on $H_2O_2$ induced DNA damage than those of GGE (23.5 ${\mu}g$/mL) or PGE (24.5 ${\mu}g$/mL). HNE induced DNA damage tended to be effectively inhibited by the lower concentration of all garlic extracts. Therefore, garlic might have protective effects against oxidative DNA damage regardless of processing methods (raw, grilled, pickled) which are the general consumed forms of garlic in Korea.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.828-834
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• 2013

In this paper, TMC (Tracker Motion Controller) as one of the many research methods for condensing efficiency improvements can be condensed into efficient solar system configuration to improve the power generation efficiency of the castle with Concentrated solar silicon and photovoltaic systems (CPV)experiments using PV systems. Microprocessor used on the solar system, tracing the development of solar altitude and latitude of each is calculated in real time. Also accept the value from the sensor, motor control and communication with the central control system by calculating the value of the current position of the sun, there is a growing burden on the applicability. Through the way the program is appropriate for solar power systems and sensors hybrid-type algorithm was implemented in the ARM core with built-in TMC, Concentrated CPV system compared to the existing PV systems, through the implementation of the TMC in the country's power generation efficiency compared and analyzed. Sensor method using existing experimental results Concentrated solar power systems to communicate the value of GPS location tracking method hybrid solar horizons in the coordinate system of the sun's azimuth and elevation angles calculated by the program in the calculations of astronomy through experimental resultslook clear day at high solar irradiation were shown to have a large difference. Stopped after a certain period of time, the sun appears in the blind spot of the sensor, the sensor error that can occur from climate change, however, do not have a cloudy and clear day solar radiation sensor does not keep track of the position of the sun, rather than the sensor of excellence could be found. It is expected that research is constantly needed for the system with ongoing research for development of solar cell efficiency increases to reduce the production cost of power generation, high efficiency condensing type according to the change of climate with the optimal development of the ability TMC.

• Radiation Oncology Journal
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• v.8 no.2
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• pp.137-144
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• 1990

The filter elution technique was used to assay Co-60 $\gamma$ ray-induced DNA single-strand breaks(SSB) in EL 4 mouse leukemia cell and mouse spleen lymphocyte. The lymphocytes were stimulated with lipopolysaccharide (LPS, 20 $\mug/ml$) to label [${^3}H$] thymidine. EL 4 cells and lymphocytes in suspension were exposed at $0^{\circ}C$ to 0 Gy, 1 Gy, 5 Gy,10 Gy of Co-60 radiation and elution procedure was performed at PH 12.1. The number of DNA single-strand breaks increased with increasing doses of $\gamma$ rays. The strand scission factor (SSF) was estimated in each experiment (eluted volume 21 ml). The slope for EL 4 cells was $0.01301\pm0.00096\;Gy^{-1}(n=5)$ and the slope for lymphocytes was $0.01097\pm0.00091\;Gy^{-1}(n=5)$. The slopes were significantly different (P<0.005). Thus EL 4 cells were more sensitive to induction of DNA SSB by ionizing radiation than lymphocytes.

• Journal of Convergence for Information Technology
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• v.8 no.5
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• pp.45-50
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• 2018

The functional nanomaterials of fluorescent dye-doped silica nanoparticles(NPs) are applied to bio applications such as bio-labeling of DNA micro-array, and bio-imaging. Organic dye-doped fluorescent silica NPs exhibit excellent bio-compatibility, non-toxic, and highly hydrophilic properties. In this study, organic fluorescent dyes were dissolved in ethanol, and deionized(DI) water. Organic fluorescent dyes were physically adsorbed to silica NPs and chemically doped to silica NPs. The fluorescence characteristics(FLC) was investigated by UV lamp irradiation of 365 nm wavelength. As results, the FLC of dye-doped silica NPs exhibits better than dye-adsorbed silica NPs and the FLC was improved with the increase of concentration of doped-dyes. The fluorescent organic dyes were well dissolved in ethanol than DI water. The photostability of dye-doped silica NPs was superior than pure fluorescent organic dye. The FLC of optimized dye-doped silica NPs would be applied to agent of non-invasive fluorescence bio-imaging in live cell and in vivo.

• Macromolecular Research
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• v.17 no.12
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• pp.963-968
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• 2009

Liquid crystal (LC; E7 and/or ML-0249)-embedded, poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-co-HFP)-based, polymer electrolytes were prepared for use in dye-sensitized solar cells (DSSCs). The electrolytes contained 1-methyl-3-propylimidazolium iodide (PMII), tetrabutylammonium iodide (TBAI), and iodine ($I_2$), which participate in the $I_3^-/I^-$ redox couple. The incorporation of photochemically stable PVdF-co-HFP in the DSSCs created a stable polymer electrolyte that resisted leakage and volatilization. DSSCs, with liquid crystal(LC)-embedded PVdF-co-HFP-based polymer electrolytes between the amphiphilic ruthenium dye N719 absorbed to the nanocrystalline $TiO_2$ photoanode and the Pt counter electrode, were fabricated. These DSSCs displayed enhanced redox couple reduction and reduced charge recombination in comparison to that fabricated from the conventional PVdF-co-HFP-based polymer electrolyte. The behavior of the polymer electrolyte was improved by the addition of optimized amounts of plasticizers, such as ethylene carbonate (EC) and propylene carbonate (PC). The significantly increased short-circuit current density ($J_{sc}$, $14.60\;mA/cm^2$) and open-circuit voltage ($V_{oc}$, 0.68 V) of these DSSCs led to a high power conversion efficiency (PCE) of 6.42% and a fill factor of 0.65 under a standard light intensity of $100\;mW/cm^2$ irradiation of AM 1.5 sunlight. A DSSC fabricated by using E7-embedded PVdF-co-HFP-based polymer electrolyte exhibited a maximum incident photon-to-current conversion efficiency (IPCE) of 50%.

• Radiation Oncology Journal
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• v.7 no.1
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• pp.29-36
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• 1989

One hundred and ten patients with carcinoma of the nasopharynx were treated by radiation therapy in Department of Therapeutic Radiology, Seoul National University Hospital between 1979 and 1985. Among these, one hundred and five patients were treated with curative intent and 5 patients with palliative aim. Excluding 16 patients who did not receive a full course of radiation therapy, the remaining 89 patients were reviewed for this analysis. Minimum follow-up period of survivors was 36 months. Forty-three percent of the patients had T4 primary lesions and $72\%$ had stage IV disease. The histology was squamous cell carcinoma in $46\%$ of the patients. undifferentiated carcinoma in $49\%$, and lymphoepithelioma in $5\%$. Total radiation dose to the primary site averaged 6,500cCY for T1, T2 lesions and 7500cCY for T3, T4 lesions. Neck node were given boost treatment to a maximum 7,500cCY depending on the extent of disease. Early primary lesion (T1, T2) and neck nodes were successfully controlled in most cases when dose of greater than 6,500cCY was delievered. Forty two patients $(47\%)$ had recurred, 16 of whom $(38\%)$ed at the primary site and $24(57\%)$ developed distant metastases. Of these. 9 patients received re-irradiation with or without chemotherapy and local control was obtained in 2 patients$(22\%)$. Actuarial overall survival and disease-free survival rate was $42\%\;and\;38\%$ at 5 years. T-stage and histologic subtype were not correlated with survival. However, N-stage was related to survival significantly (p=0.043).