• Toxicological Research
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• 제8권2호
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• pp.171-177
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• 1992

To investigate a short term screening method for carcinogenic quinone compounds, 8-hydroxydeoxyguanosine (8-OHdG), an oxidative DNA damage, was determined in the kidney and liver DNA isolated from Sprague-Dawley rats after i.p.injection of 7 mg/kg adriamycin (AM), 7mg/kg tetrahydropyranyladriamycin (THP), and 10mg/kg daunomycin (DM) by HPLC-electrochemical detector system. 8-OHdG was also determined from rat hepatocvtes and calf thymus DNA exposed to AM, DM and THP. When rats were treated with DM and THP, 8-OHdG was significantly increased in the kidney compared to control group, and remained at high level (7.9~9.0, 8-OHdG/dG${\times}10^4$)at the end of experiments (48hr after treatment). 8-OHdG level in cultured hepatocyte exposed to AM, DM and THP was 1.5~2 fold higher than control at all time points. (1,2,3,4hr after treatment). From calf thymus DNA exposed to AM, DM and THP, 8-OHdG was 2.5 fold higher than of control. These results suggest that quantitation of 8-OHdG may provide a useful marker for identifying target organ in oxidative chemical carcinogenesis and for short term screening of free radical generating carcinogens.

• 미생물학회지
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• 제14권2호
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• pp.65-74
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• 1976

Atternaria sp. was isolated from soil and crude cellulases were prepared from wheat bran culture of the fungus. The activities of the crude enzyme were studied on five different subvstrates and some phsical properties were also examined, crude enzymes were purified by column chromatography on DEAE Sephadex and Sephadex, Isozymes were separated some of which were active specifically on DEAE cellulose and some were primarily active on cellulose and CM-cellulose. The optimal points of pH and temperature for the crude enzyme were varied depending on the substrates ; On cellulose they were at pH 6.0 and 40.deg.C, on CM-cellulose at pH's 4.0 and 6.0 and 60.deg.C, and on DEAW-cellulose at pH 5.0 and 50.deg.C. Two active fractions, F-1 and F-II on Na-CMC was used as substrate the Km values of crude enzyme, F-I and F-II were calculated to be $4{\times}10^{-5}$ , 1.1 * 10$^{-4}$ , and $1.25{\times}10^{-4}mN$ resepctively. The Ki value of $Cu^{++}$ for crude enzyme was$4{\times}^{-4}mN$ , while that of $Nm^{++}$ while in the same concentration of $Mn^{++}$ it reached to 91%. Some 57% activity of F-1 was inhibited in s mN $Cu^{++}$, whereas it was inhibited as much as 81% in the same concentration above the concentration of 0.3 mM with tis activity reaching up to 137% in 2 mM. On the other hand the F-11 was inhibited by the presence of M $n^{++}$ and some 67% activity was inhibited at 2mM.

• Applied Biological Chemistry
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• 제30권2호
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• pp.133-140
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• 1987

6개 품종의 감자에서 분리한 전분의 물리화학적 특성을 조사하였다. Arkula에서 분리한 전분은 다른 품종에 비해 회분 함량이 훨씬 낮았다. 분리 전분입자의 형태는 난형과 구형이었고, 평균입경은 $25{\sim}26.9{\mu}$였다. 전분의 무기질 성분중 인산과 칼륨이 가장 중요한 성분이었다. 분리전분의 아밀로스 함량은 $32{\sim}27.2%$의 범위였고, blue value와 alkali number는 각각 $0.42{\sim}0.45$, $5.8{\sim}7.7$ 정도였다. 아밀로그람에 의한 호화 개시온도는 $63.5{\sim}68^{\circ}C$의 범위였고, Noot Sack이 모든 지표에서 가장 높은 값을 나타내었다. 팽윤력과 용해도는 $50^{\circ}C$까지는 큰 변화가 없었으나, 그후 급격히 증가했다.

• 국제초고층학회논문집
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• 제6권2호
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• pp.165-175
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• 2017

The importance of designing urban building complexes so that they obtain 'urban' power, rather than become isolated from the surrounding urban context, has been well recognized by both researchers and practitioners. Nevertheless, most current discussions are made from architects' personal experiences and intuition, and lack a quantitative understanding, to which obstacles include an in-depth exploration of the 'urban' power between building complexes and the urban environment. This paper attempts to measure this feature of 'urban', i.e., 'urbanity,' through a new analytical approach derived from the opendata environment. Three measurements that can be easily collected though the Google Maps API and Open Street Map are applied herein to evaluate high or low values of urbanity. Specifically, these are 'metric depth', i.e., the scale of extended public space, 'development density', i.e., density and distribution of point of interests (POIs), and 'type diversity', i.e., diversity of different commercial types. Six cases located in Japan, China and Hong Kong respectively are ranked based on this analytical approach and compared with each other. It shows that Japanese cases, i.e., Osaka Station City and Namba Parks, Osaka, obtained clearly higher values than cases in Shanghai and Hong Kong. On one hand, the insight generated from measuring and explaining 'urban' power would help to assist better implementation of this feature in the design of urban building complexes. On the other hand, this analytical approach can be easily extended to achieve a large-scale measurement and comparison among different urban building complexes, which is also helpful for design practitioners.

• Journal of Ginseng Research
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• 제34권1호
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• pp.17-22
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• 2010

Sesquiterpenes are found naturally in plants and insects as defensive agents or pheromones. They are produced in the cytosolic acetate/mevalonate pathway for isoprenoid biosynthesis. The inducible sesquiterpene synthases (STS), which are responsible for the transformation of the precursor farnesyl diphosphate, appear to generate very few olefinic products that are converted to biologically active metabolites. In this study, we isolated the STS gene from Panax ginseng C.A. Meyer, designated PgSTS, and investigated the correlation between its expression and various abiotic stresses using real-time PCR. PgSTS cDNA was observed to be 1,883 nucleotides long with an open reading frame of 1,707 bp, encoding a protein of 568 amino acids. The molecular mass of the mature protein was determined to be 65.5 kDa, with a predicted isoelectric point of 5.98. A GenBank BlastX search revealed the deduced amino acid sequence of PgSTS to be homologous to STS from other plants, with the highest similarity to an STS from Lycopersicon hirsutum (55% identity, 51% similarity). Real-time PCR analysis showed that different abiotic stresses triggered significant induction of PgSTS expression at different time points.

• IMMUNE NETWORK
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• 제2권1호
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• pp.25-34
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• 2002

Background: Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by synovial hyperplasia and joint destruction. The synovial fibroblasts express cell adhesion molecules and have a role in adhesive interation with inflammatory cells in synovial tissue. It has been suggested that hypoxic conditioins are thought to exist in arthritic joints, and several studies indicate that reactive oxygen species (ROS) produced in hypoxic condition can initiate events that lead to pro-adhesive changes via increased expression of adhesion molecules. So, this study wsa designed to examine whether antioxidant can inhibit hypoxia-induced expression of ICAM-1 in cultured human synovial fibroblasts. Methods: Synovial fibroblasts were isolated from synovial tissue in patients with RA and cultured at hypoxic condition. Antioxidant, PDTC (pyrrolidine dithiocarbamate) were pre-treated for an hour before the hypoxic culture and synovial fibroblasts were harvested at 0, 6, 12, 24, 48 hours time points. Cell surface ICAM-1 expression in synovial fibroblasts was examined by the flow cytometric analysis. To analyse the expression of ICAM-1 mRNA, reverse-transcriptase polymerase chain reaction (RT-PCR) was performed. The levels of cytokines in culture supernatants were measured by ELISA, and activation of NF-${\kappa}B$ was analysed by electrophoretic mobility shift assay. The adhesive reaction between synovial fibroblasts and lymphocytes was assayed by measurement of fluorescent intensity of BCECF-AM in lymphocytes. Results: Hypoxic stimuli up-regulated the ICAM-1 expression as well as the adhesive interaction of human synvial fibroblasts to lymphocytes in a time-dependent manner, and PDTC inhibited hpyoxia-induced ICAM-1 expression and cell-cell interaction. PDTC also inhibited the hypoxia-induced activation of intracellular transcription factor, NF-${\kappa}B$. PDTC decreased the amount of hypoxia-induced production of IL-$1{\beta}$ and TNF-${\alpha}$. Conclusion: These studies demonstrate that PDTC inhibit the hypoxia-induced expression of the adhesion molecule, ICAM-1 and activation of NF-${\kappa}B$ in cultured human synovial fibroblasts.

• Biomaterials and Biomechanics in Bioengineering
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• 제3권2호
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• pp.105-114
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• 2016

The purpose of this study is to evaluate the effects of cryopreservation on dental pulp-derived stem cells (DPSC) viability over a period of three years. Dental pulp-derived stem cells were isolated and cultured from thirty-one healthy teeth. DPSC isolates were assessed for doubling-time and baseline viability prior to cryopreservation and were assessed again at three time points; one week (T1), 18 months (T2), and 36 months (T3). DPSC can be grouped based on their observed doubling times; slow (sDT), intermediate (iDT), and rapid (rDT). Viability results demonstrated all three types of DPSC isolates (sDT, iDT and rDT) exhibit time-dependent reductions in viability following cryopreservation, with the greatest reduction observed among sDT-DPSCs and the smallest observed among the rDT-DPSC isolates. Cryopreserved DPSCs demonstrate time-dependent reductions in cellular viability. Although reductions in viability were smallest at the initial time point (T1) and greatest at the final time point (T3), these changes were markedly different among DPSC isolates with similar doubling times (DTs). Furthermore, the analysis of various DPSC biomarkers - including both intracellular and cell surface markers, revealed differential mRNA expression. More specifically, the relative high expression of Sox-2 was only found only among the rDT isolates, which was associated with the smallest reduction in viability over time. The expression of Oct4 and NANOG were also higher among rDT isolates, however, expression was comparatively lower among the sDT isolates that had the highest reduction in cellular viability over the course of this study. These data may suggest that some biomarkers, including Sox-2, Oct4 and NANOG may have some potential for use as biomarkers that may be associated with either higher or lower cellular viability over long-term storage applications although more research will be needed to confirm these findings.

• The Korean Journal of Physiology and Pharmacology
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• 제6권5호
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• pp.275-279
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• 2002

Nerve growth factor (NGF) is an important autocrine growth factor and also a survival factor for keratinocytes. NGF may act in the hyperproliferative condition, psoriasis. Clinically, the combination of psoralen and UVA (PUVA) has been used in the treatment of a wide variety of cutaneous disorders, such as psoriasis and vitiligo. However, the precise therapeutic mechanism of PUVA on the dermatologic diseases remains unclear. The purpose of this study was to examine whether the expression of NGF in cultured keratinocytes is influenced by PUVA. Thus, normal human keratinocytes were isolated from neonatal foreskin, and the third to fifth-passaged cells were used in this study. The cells were exposed to various doses of UVA (30, 60, 120 $mJ/cm^2)$ after adding 8-methoxypsoralen (8-MOP) to examine the expression of NGF mRNA. The RNA and protein of the cells were extracted at various time points (1, 8, 24 hours) after UVA irradiation to examine the expression of NGF mRNA and production of NGF protein. In keratinocytes, there were no differences in the expression of NGF mRNA between the different doses of UVA irradiation, however, the expression of NGF mRNA in UVA and PUVA groups tended to increase as the time increased. The expression of NGF mRNA was the highest in PUVA group, followed by UVA group and the lowest in 8-MOP group. The expressions of NGF protein at 1 and 8 hours after UVA irradiation were lower in the PUVA group than in the other groups. This study showed that the expression level of NGF protein in keratinocytes was relatively lower in the PUVA groups than in the other groups, suggesting that the therapeutic mechanism of PUVA in psoriasis is related to the decrease of NGF protein.

• Tribology and Lubricants
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• 제30권6호
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• pp.323-329
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• 2014

The friction-reducing properties of lubricants containing ionic liquids based on ammonium dithiocarbamate are studied. The ionic liquids are produced through the following two steps: the synthesis of sodium alkyl dithiocarbamates via the substitution reaction of dialkylamine and carbon disulfide and their subsequent conversion into ammonium dithiocarbamate-based ionic liquids through an ion-exchange reaction with a quaternary alkyl ammonium halide salt. The structures of the ionic liquids are characterized by NMR spectroscopy and Fourier transform infrared spectroscopy. The isolated yields of the ionic liquids, which are viscous and pale yellow, are approximately 92%. The Brookfield viscosities and pour points of the ionic liquids are determined. Further, their wear resistances are measured through the four-ball wear test and the Schwingung Reibung Ver-schleiss (oscillation, friction, wear) test. The wear scar diameter of the lubricants containing 1 wt of the quaternary alkyl ammonium dithiocarbamate-based ionic liquids (0.475-0.631 mm) is significantly lower than that of the base oil (0.825 mm), proving that the ammonium dithiocarbamate-based ionic liquids have good friction-reducing characteristics. However, these friction-reducing characteristics fade significantly after long-term storage, owing to the degradation of the ionic liquids.

• 디지털융복합연구
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• 제17권2호
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• pp.399-404
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• 2019

본 연구는 국내외 활발히 이용되고 있는 OTT, 온라인 동영상 서비스, 그 중 넷플릭스와 왓챠플레이를 중심으로 사용자의 서비스 이용 현황에 관해 연구하여 K-콘텐츠 동영상 서비스를 통한 한국 엔터테인먼트 발전 전략을 제시하는데 그 목적이 있다. 연구 방법으로는 1차 사례연구를 통해 국내의 동영상 스트리밍 서비스와 국외의 OTT서비스의 특징 및 한국 콘텐츠 제공성을 조사하였다. 그리고 2차로 넷플릭스와 왓챠플레이 이용자 8명을 대상으로 하는 심층 인터뷰를 통해 사용자 경험과 한국엔터테인먼트 동영상 스트리밍 서비스의 수요를 파악하였다. 그 결과, 전략에 관한 두 가지 포인트를 도출해낼 수 있었다. 첫째, 단독화 채널 전략. 둘째, 콘텐츠의 다양화와 개인화 전략. 이 연구는 넷플릭스와 왓챠플레이를 통해 한국 엔터테인먼트 산업의 방향성에 관한 전략을 제시했다는 점에 의의가 있다. 후속 연구를 통해 한국 엔터테인먼트 산업의 개선 방안을 보완하고, 한국 엔터테인먼트 발전 전략 수립에 도움이 되기를 기대한다.