• Journal of Soil and Groundwater Environment
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• 제15권4호
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• pp.46-52
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• 2010

Acid mine drainage occurs when sulfide minerals are exposed to an oxidizing environment. The objective of this study was to inhibit the oxidation of pyrite by applying various coating agent such as $KH_2PO_4$, MgO and $KMnO_4$ over its surface as an oxidation inhibitors. Experiments were conducted for 8 days to test the feasibility of oxidation inhibitors. The optimal condition of coating agent for standard pyrite and IK mine was the combination of 0.01M $KH_2PO_4$, 0.01M NaOAc and 0.01M NaClO. Otherwise, for YD mine the combination of 0.01M $KMnO_4$, 0.01M NaOAc and 0.01M NaClO. The $SO_4^{2-}$ reduction efficiency of pyrite, IK and YD mine samples was 70, 92 and 84%, respectively. For 8 days, no significant increase of $SO_4^{2-}$ from pyrite sample coated with inhibitor was observed. The pH of solution remains in between 4 to 6 for the reaction conditions.

• Journal of Applied Biological Chemistry
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• 제55권4호
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• pp.201-205
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• 2012

The present study was conducted to evaluate of the 1,1-Diphenyl-2-Picrylhydrazyl (DPPH) radical scavenging effect, cytotoxicity and tyrosinase inhibition activities using methanol extracts from different parts of four herb plants. The results showed that whole and root extracts of yarrow the highest total polyphenol and flavonoid contents as well as whole of yarrow revealed the highest DPPH radical scavenging effect. In cytotoxicity test against three cancer cell lines, HeLa (uterus), SK-Hep-1 (liver), and YD-15 (oral), the whole extract of feverfew showed the highest toxicity with $IC_{50}$ values of $102.58-138.68{\mu}g/mL$. Also, mallow root extract ($71.24{\mu}g/mL$) exhibited potent tyrosinase inhibitory activity comparable to arbutin ($69.56{\mu}g/mL$), which was used as the control.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권6호
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• pp.490-495
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• 2011

Introduction: Development of carcinoma on oral tongue may cause bilateral cervical lymph node metastasis, rapid invasion and growth of the cancer cells due to rich blood supply in muscle tissues. It is not only difficult to develop an animal experimental model, but also to proceed follow-up research after the development of such model as the induction of cancer lead to difficulty in taking nutrition for the experimental animals that often causes early death. Materials and Methods: IIn this study, author have transplanted YD-$10B_{mod}$ cells into nude mouse oral tongues with different cells number ($5{\times}10^4$, $5{\times}10^5$, $5{\times}10^6$ cells/mouse) and observed the development aspect of oral tongue cancers. Results: The cancer developed from orthotopic transplantation of YD-$10B_{mod}$ cells into nude mouse oral tongue show invasion and central necrosis of the tumor, similar to the cancers developed human oral tongue cancer. The difference in tumor size and the time of central necrosis development depending on the number of transplanted tumor cells shows the feasibility of extending the survival period of the nude mouse by limiting the transplanted tumor cells to < $5{\times}10^4$ cells/mouse or under per nude mouse. Conclusion: This nude mouse model could be used effectively in developing effective chemotheray agent and establishing an animal experimental model that can be used to study the mechanism of cervical lymph node metastasis of the oral tongue cancer.

• Journal of dental hygiene science
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• 제18권3호
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• pp.188-193
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• 2018

The aim of the current study was to demonstrate the potential therapeutic efficacy of resveratrol in oral cancer patients. Lysophosphatidic acid (LPA) intensifies cancer cell invasion and metastasis, whereas resveratrol, a natural polyphenolic compound, possesses antitumor activity, suppressing cell proliferation and progression in various cancer cell lines (ovarian, gastric, oral, pancreatic, colon, and prostate cancer cells). In addition, resveratrol has been identified as an inhibitor of LPA-induced proteolytic enzyme expression and ovarian cancer invasion. Furthermore, resveratrol was shown to inhibit oral cancer cell invasion by downregulating hypoxia-inducible factor $1{\alpha}$ and vascular endothelial growth factor expression. Recently, we demonstrated that LPA is important for the expression of transcription factors TWIST and SLUG during epithelial-mesenchymal transition (EMT) in oral squamous carcinoma cells. In this study, we treated serum-starved cultures of oral squamous carcinoma cell line YD-10B with resveratrol for 24 hours prior to stimulation with LPA. To identify an optimal resveratrol concentration that does not induce apoptosis in oral squamous carcinoma cells, we determined the toxicity of resveratrol in YD-10B cells by assessing their viability using the MTT assay. Another assay was performed using Matrigel-coated cell culture inserts to detect oral cancer cell invasion activity. Immunoblotting was applied for analyzing protein expression of SLUG, TWIST1, E-cadherin, and GAPDH. We demonstrated that resveratrol efficiently inhibited LPA-induced oral cancer cell EMT and invasion by downregulating SLUG and TWIST1 expression. Therefore, resveratrol may potentially reduce oral squamous carcinoma cell invasion and metastasis in oral cancer patients, improving their survival outcomes. In summary, we identified new targets for the development of therapies against oral cancer progression and characterized the therapeutic potential of resveratrol for the treatment of oral cancer patients.

• Journal of the Korean Applied Science and Technology
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• 제33권4호
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• pp.615-626
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• 2016

In the paper, mild solvent soluble alkyl group modified epoxy resins were prepared via a three-step method; (1) the condensation reaction of dodecyl phenol (DP) and formaldehyde, (2) the crosslinking reaction of dodecyl phnol novolac compound (DPC) and bisphenol A diglycidyl ether, (3) the dodecyl phenol novolac epoxy resins containing fatty acid (DPFA) was prepared by introducing fatty acid to DPC. Equivalent ratios of DP and formaldehyde were 1.25~1.333/1.0. Equivalent ratio of DPC and bisphenol A diglycidyl ether (YD-128) was 1.0/2.0. Reactivity, viscosity, molecular weight, solvent solubility, and physical properties of DPFA were investigated. The result show that as the number of aromatic ring of DPFA increased, viscosity increased and solvent solubility improved. When we test the properties of coatings by blending the synthesized DPFA with a white pigment, DPFAC-5 using triphenylphosphine (TPP) as a ring-open catalyst showed optical performance for drying time, adhesion, hardness, impact resistance, acid resistance and storage stability.

• Journal of dental hygiene science
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• 제19권2호
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• pp.141-146
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• 2019

Background: Oral cancer has a high incidence worldwide and has been closely associated with smoking, alcohol, and infection by the human papillomavirus. Metastasis is highly important for oral cancer survival. Lysophosphatidic acid (LPA) is a bioactive lipid mediator that promotes various cellular processes, including cell survival, proliferation, metastasis, and invasion. Signal transducer and activator of transcription (STATs) are transcription factors that mediate gene expression. Among the seven types of STATs in mammals, STAT3 is involved in invasion and metastasis of numerous tumors. However, little is known about the role of STAT3 in oral tumor invasion. In the present study, we hypothesized that STAT3 mediates LPA-induced oral cancer invasion. Methods: Immunoblotting was performed to analyze LPA-induced STAT3 activation. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was performed to assess the survival rates of YD-10B cells. STAT3 levels in LPA-treated oral tumor cells were evaluated by performing in vitro invasion assay. Results: To the best of our knowledge, this is the first study to demonstrate that LPA enhances STAT3 phosphorylation in oral cancer. In addition, treatment with WP1066, a selective inhibitor of STAT3, at a concentration that does not cause severe reduction in cell viability, significantly attenuated LPA-induced YD-10B cancer cell invasion. Conclusion: The results suggested that LPA induces oral tumor cells with greater invasive potential via STAT3 activation. Our findings provided important insights into the mechanisms underlying mouth neoplasms.

• The Korea Journal of Herbology
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• 제30권2호
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• pp.25-30
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• 2015

Objectives : Laver (Porphyra tenera), a red algae species, is one of the most widely consumed edible seaweed in Korea. Laver contains various substances such as essential amino acid, fiber, minerals and polyphenols that benefit human health. In the present study, we prepared ethanol extracts from commercially processed product of Porphyra tenera, and evaluated the growth inhibitory effect against human oral squamous carcinoma YD-10B cells. Methods : Cell viability was measured by MTT assay. Apoptosis was confirmed by TUNEL assay and flow cytometry with the green fluorescent dye FITC annexin V entering apoptotic cells and the red fluorescent dye PI not entering. The expression of the relevant proteins was detected using Western blot. Results : Ethanol extracts of Porphyra tenera (PTE, $50-200{\mu}g/m{\ell}$) caused a significant decrease of cell viability in a dose dependant manner. The cell death occurred as a result of apoptotic process as determined by TUNEL assay and flow cytometric analysis. In line with this observation, decrease in procaspase proteins and increase in cytosolic cytochrome c were observed in cells treated with PTE. In addition, exposure to PTE decreased the expression levels of Bcl-2, and induced PARP cleavage and AIF translocation from mitochondria to nucleus. Conclusions : In conclusion, PTE exerts anti-cancer effects by inducing apoptosis via caspase activation and AIF nuclear translocation in YD-10B cells. These results provide evidence for the possible therapeutic effect of Porphyra tenera in oral cancer cells.

• Journal of the Korean Magnetic Resonance Society
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• 제20권2호
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• pp.41-45
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• 2016

Chemical investigation of a marine-derived fungus, Penicillium sp. 108YD020, resulted in the discovery of six bile acid derivatives, glycocholic acid (1), glycocholic acid methyl ester (2), cholic acid (3), glycochenodeoxycholic acid (4), glycodeoxycholic acid methyl ester (5), and cholic acid methyl ester (6). The structures of six bile acid derivatives 1-6 were determined by the detailed analysis of 1D, 2D NMR and LC-MS data, along with chemical methods and literature data analysis.

• Journal of the Korean Society of Visualization
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• 제5권2호
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• pp.3-8
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• 2007

Yellow dust problem is one of serious environmental problems in East Asia. The earth's abnormal climate changes and rapid industrializations over the mainland China seem to make the matter worse than ever before. In order to solve the yellow dust problem, collaborative works are necessary not only in the fields of meteorology and engineering, and but also through national consistent policies beyond the nations. In this regards, reporting on current policies of our meteorological administrative on the yellow dust problem can be regarded as valuable services for the engineers working in the fields of energy and environments.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 한국축산식품학회 2005년도 제36차 추계 학술발표대회
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• pp.342-345
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• 2005

본 연구는 Saccharomyces cerevisiae를 단백질 분해 효소로 처리하여 얻은 가수분해물의 식욕 억제 효과에 대한 기초 자료를 마련하고자 실시되었다. 본 연구에서 열량 및 영양소 섭취,체구성 및 기초대사량 그리고 신체둘레 및 피하지방 두께를 측정한 결과 전반적으로 ID군에 비해 YD군의 체중 감량 효과가 큰 것으로 나타났다. 이는 효모가수분해물의 식욕감소에 관련한 결과의 생각되나 4주라는 비교적 짧은 연구기간으로 인해 통계적으로 유의한 차이를 보이지 않은 것으로 사료된다.