• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.69-72
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• 2000

After 300hours cultivation Chlorella vulgaris in standard medium in which the initial cell seeding concentration of $0.7{\times}10^4ells/mL$, $1.21{\times}10^5ells/mL$ was gained but in the case of 0.30g/L of initial cell seeding concentration the maximum growth rate of $0.162g/L\;{\cdot}\;day$ was shown. In the case of the initial glucose concentration of 2.00g/L, the cell concentration was changed from initial 0.025g cells/L to 0.874g cells/L after 140hours cultivation, the specific growth rate was $0.243h^{-1}$, but 268mL of gases were formed in 72hours, and after that, hydrogen evolution was completed. Formed gases were not all hydrogen, and 19.87 mol% of hydrogen is detected by GC. Analyzing the composition of Chlorella vulgaris by elementary analysis, it is found to be $C_{1.000}\;H_{1.774}\;N_{0.125}\;O_{0.557}$, and $CO_2$ conversion rate by Chlorella vulgaris was $0.616\;cells/g\;{\cdot}\;CO_2$

• Journal of Animal Environmental Science
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• v.13 no.2
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• pp.97-104
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• 2007

This study was carried out to develop the modified cyclone dust collector in windowless broiler building measuring 12 m wide, 46 m long, with a side wall height of 3 m and a capacity of 12,800 birds. Ventilation rate in windowless broiler building was $0.014{\sim}0.015\;and\;0.158{\sim}0.181cmm$ in second weeks and fifth weeks of age, respectively. Ammonia concentration was $13{\sim}16\;and\;20{\sim}24\;ppm$ in first and second weeks of age, respectively. Amount of dust collected in dust collector each week was 104.1, 274.7 and 388.6g in first, second and third weeks of age. But it was decreased from fourth weeks of age because of the increased ventilation rate. Total suspended particulate(TSP) of polluted air was $3,111.7{\sim}8,745.2{\mu}g/m^3$, but it was decreased to $530.8{\sim}2,264.4{\mu}g/m^3$ when it passed through the dust collector. Collecting efficiency was $54.2{\sim}82.9%$ in TSP. But collecting efficiency of Particulate matter smaller than $1{\mu}g$ (PM1.0) was $7.6{\sim}33.8%$, and lower than TSP. TSP concentration in control broiler house was 1,387.6 and $4,210.1{\mu}g/m^3$ in first and fourth weeks of age, respectively. But it was decreased to 876.3 and $2,535.3{\mu}g/m^3$ in broiler house operated dust collector in first and fourth weeks of age, respectively. Dust collecting efficiency for TSP was $36.8{\sim}39.8%$, and it was decreased to $11.4{\sim}39.8%$ in smaller dust size.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.10
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• pp.868-879
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• 2000

이 논문은 에지나 정점, 혹은 모두에 고장이 있는 이중 루프 네트워크의 해밀톤 성질을 고려한다. 이중 루프 네트워크 G(mn;1,m)은 m$\times$m 그리드 그래프에 에지를 추가한 4-정규 그래프이다. m 과 n 이 모두 짝수인 이중 루프 네트워크 G(mn;1,m)은 고장난 요소(에지와 정점)의 수가 1이하인 경우에 해밀톤 연결되어 있고, 고장난 요소의 수가 2 이하인 경우에 항상 해밀톤 사이클을 가짐을 보인다.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.420-432
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• 2021

This study was conducted to evaluate antioxidant, antibacterial, anti-inflammatory, and digestive enzyme activity in water extract (SAW) and 60% ethanol extract (SAE) from Stachys sieboldii. As the treatment concentration of each extract S. sieboldii extract increased, antibacterial and antioxidant activity increased. The total polyphenol and total flavonoid contents of SAW were 106.25 ± 0.94 mgGAE/g, 24.4 ± 0.24 mgQE/g and SAE were 124.61 ± 1.11 mgGAE/g, 45.2 ± 3.52 mgQE/g, respectively. The 400 ㎍/mL of SAW and SAE performed more than 53% protective effects against oxidative stress in HepG2 cell lines. All extracts were not showed cytotoxicity to RAW 264.7 cell line at 100 ㎍/mL. NO production was reduced to 44.3 ± 1.4% for SAW and 45.1 ± 1.0% for SAE at a concentration of 100 ㎍/mL. The production of inflammatory cytokines each TNF-α, IL-1β, and IL-6 was inhibited in a concentration-dependent. S. sieboldii extract did not showed Caco-2 cells cytotoxicity and inhibited NO production in concentration-dependent. As the concentration of the S. sieboldii extract increased of α-amylase and protease enzymes activity, which are digestive enzyme. As a result of the experiment, it is judged that it can be used as basic data for the development of health food using S. sieboldii.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.3
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• pp.243-250
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• 2009

To develop a new natural whitening agent for cosmetics, we investigated the inhibitory effects of Poria cocos Bark extracts (PCBE) and its active compound on melanogenesis. PCBE showed ROS scavenging activities in 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and xanthine/xanthine oxidase system with the $IC_{50}$ values of $19.4{\pm}2.21{\mu}g$/mL and $IC_{50}=103{\pm}3.33{\mu}g$/mL, respectively. PCBE reduced intracellular tyrosinase activity about 34 % at concentration of $50{\mu}g$/mL. And PCBE reduced melanin contents of B16 melanoma cells about 51 % at concentration of $50{\mu}g$/mL without cell cytotoxicity (below $100{\mu}g$/mL). We purified one active compound from PCBE and identified its structure. It was identified as 3-$\beta$-hydroxylanosta-7,9(11),24-trien-4-oic acid, triterpene family, by $^1H$-NMR, $^{13}C$-NMR and Mass analysis. 3-$\beta$-hydroxylanosta-7,9(11),24-trien-4-oic acid showed ROS scavenging activities in DPPH radical and xanthine/xanthine oxidase system with the $IC_{50}$ values of $4.3{\pm}0.15{\mu}g$/mL and $54{\pm}1.67{\mu}g$/mL, respectively. Also, it was shown that 3-$\beta$-hydroxylanosta-7,9(11),24-trien-4-oic acid reduced intracellular tyrosinase activity about 43 % at concentration of $10{\mu}g$/mL. And it inhibited melanin synthesis in a dose dependent manner ($IC_{50}=3.6{\mu}g$/mL) without cell cytotoxicity (below $100{\mu}g$/mL). 3-$\beta$-hydroxylanosta-7,9(11),24-trien-4-oic acid inhibited tyrosinase, TRP-1 and TRP-2 expression at protein level. These results suggest that PCBE and 3-$\beta$-hydroxylanosta-7,9(11),24-trien-4-oic acid reduced melanin formation by the inhibition of tyrosinase activity and expression in B16 melanoma cells. Therefore, we suggest that PCBE could be used as a useful whitening agent.

• Food Science and Preservation
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• v.18 no.1
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• pp.79-86
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• 2011

Three bark extracts of Albizia julibrissin were prepared using water (AW), 70% (v/v) ethanol (AE), and hot water (AHW). Organic solvent fractions were analyzed for total flavonoids and polyphenols, antioxidant activities, and inhibitory activities against xanthine oxidase. Total flavonoid and polyphenol contents of the AHW extract were 8.57 mg/g and 108.67 mg/g, respectively. The SOD-like activities of all extracts, assayed at 1.0 mg/mL, were 10.46-16.73%. The nitrite-scavenging ability of the AHW extract, assayed at pH 1.2, was 60.82%, and the $IC_{50}$ value was $770.18\;{\mu}g$/mL. The electron-donating ability of the AHW extract, at 0.3 mg/mL, was 92.30%; the $IC_{50}$ values of the AW and AHW extracts were $31.31\;{\mu}g$/mL and $36.22\;{\mu}g$/mL, respectively; thus higher than that of ascorbic acid ($39.06\;{\mu}g$/mL). Xanthine oxidase inhibition by the AHW extract, at 1.0 mg/mL, was 94.05%. These results indicate that the AHW of A. julibrissin has potential as a natural antioxidant, for addition to foods and nutraceuticals.

• Food Science and Preservation
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• v.20 no.5
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• pp.691-698
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• 2013

The biological activities of Smilax china L. rhizome (SCR), hot water (SCRW) and 70% ethanol extract (SCRE) were analyzed. The total phenolic contents of SCRW and SCRE were 51.7 and 100.5 mg/g, respectively. The measured flavonoid content of SCRW ($67.7{\mu}g/g$) was almost double that of SCRE ($31.7{\mu}g/g$). SCRE ($IC_{50}=42.4{\mu}g/mL$) exhibited stronger antioxidant activity in the DPPH system than the positive control ${\alpha}$-tocopherol ($71.3{\mu}g/mL$) or butylated hydroxy anisole ($53.8{\mu}g/mL$) did. SCRE ($IC_{50}=50.3{\mu}g/mL$) also showed stronger ABTS radical scavenging activity, as did ${\alpha}$-tocopherol ($67.1{\mu}g/mL$). The SOD-like activity and Tyrosinase inhibition activity of SCRW and SCRE showed almost the same pattern. The best SOD-like activity and tyrosinase inhibition activity were measured as 24.9% and 20.3% in SCRW at $1,000{\mu}g/mL$, respectively. The cytotoxic effects of the SCR extracts were analyzed via MTT assay on human cancer and normal cells. SCRW and SCRE did not show cytotoxicity up to the concentration of $1,000{\mu}g/mL$ against the normal human cell line HEK293. Against human breast cancer cells (MCF-7), SCRW inhibited MCF-7 growth (by 27.6%) better than the anticancer drug cyclophosphamide (15.5%) at $1,000{\mu}g/mL$. SCRE ($1,000{\mu}g/mL$) inhibited the growth of human lung cancer cells A549 (37.6%) and human stomach cancer cells AGS (53.6%) more effective than did SCRW (21.0% and 35.4%) or CPA (22.2% and 31.7%). These results suggest the potential use of SCRE and SCRW as an excellent antioxidant and antiproliferative substance, respectively.

• The Korean Journal of Food And Nutrition
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• v.18 no.4
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• pp.373-379
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• 2005

The volatile components of Pinus densiflora needles were studied by gas chromatography-mass spectrometry(GC-MS), using seven kinds of solid phase microextraction (SPME) fibers, seven in SPME fibers: 100 ${\mu}m$ PDMS, 65 ${\mu}m$ PDMS/DVB, 65 ${\mu}m$ SF-PDMS/DVB, 85 ${\mu}m$ PA, 75 ${\mu}m$ CAR/PDMS, 65 ${\mu}m$ CW/DVB and 50/30 ${\mu}m$ DVB/CAR/PDMS fibers. A total of 40 components were identified by using the seven different SPME fibers. The identified components were classified, according to their functionalities, as follows: 26 hydro-carbons, 7 alcohols, 4 carbonyl compounds, and 3 esters. The major volatile components of Pinus densiflora needles identified by these SPME fibers were $\alpha$-pinene ($1.7\~21.7\;{\mu}g/g$), $\beta$-myrcene ($2.0\~20.1\;{\mu}g/g$), $\beta$-phel-landrene ($4.6\~22.8\;{\mu}g/g$), $\beta$-caryophyllene ($6.7\~26.0\;{\mu}g/g$) germacrene D ($1.1\~11.9\;{\mu}g/g$). In the comparison of the seven SPME fibers, PDMS appeared to be the most suitable fiber for the analysis of hydrocarbon compounds and CAR/DPMS, PDMS/DVB, CW/VB and DVB/CAR/PDMS are shown to be optimal for analysis of the alcohols and carbonyl compounds.

• Proceedings of the Korean Statistical Society Conference
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• 2004.11a
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• pp.301-306
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• 2004

We consider the $P_\lambda\;^M$ service policy for an M/G/1 queue in which the service rate is increased from 1 to M at the exponential setup time after the level of workload exceeds $\lambda$. The stationary distribution of the workload is explicitly obtained through the level crossing argument.

• Journal of Periodontal and Implant Science
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• v.36 no.2
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• pp.449-459
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• 2006

DFDBA(Decalcified freeze-dried bone allograft) is one of the allograft materials for periodontal bone regeneration. DFDBA provides an osteoconductive surface and osteoinductive factors. Therefore, DFDBA have been used successfully to regenerate the attachment apparatus during periodontal treatment. But recent studies was reported that wide variations in commercial bone bank preparations of DFDBA do exist, including the ability to induce new bone formation. DFDBA was experimental materials that was recovered, processed, tested, shipped and invoiced through Musculoskeletal Transplant Foundation. MTF(Musculoskeletal Transplant Foundation) is the world largest, non-profit, AATB(American Association of Tissue Banks) accredited tissue bank. The objective of this study was to determine the effects of serial dilutions of a DFDBA on human fetal osteoblastic cell proliferation and their potential to form and mineralize bone nodules. Human fetal osteoblastic cell line(hFOB 1.19) was cultured with DMEM and SSE($1{\mu}g/m{\ell}$,$10{\mu}g/m{\ell}$, $100{\mu}g/m{\ell}$, $1mg/m{\ell}$) at $34^{\circ}C$ with 5% CO2 in 100% humidity. Cell proliferation was significantly increased at $1mg/m{\ell}$, $100{\mu}g$, $10{\mu}g/m{\ell}$, $1{\mu}g/m{\ell}$, $100ng/m{\ell}$, $10ng/m{\ell}$, $1ng/m{\ell}$ of DFDBA after 5 days incubation (p<0.05). Alkaline Phosphatase(ALP) level was significantly increased in $100ng/m{\ell}$, $10ng/m{\ell}$, $1ng/m{\ell}$ of DFDABA(p<0.05). A quantified calcium accumulation was significantly increased at $1ng/m{\ell}$, $10ng/m{\ell}$ of MTF(p<0.05). These results indicated that DFDBA has an inductive effect on bone formation in vitro.