• 한국세라믹학회지
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• 제38권7호
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• pp.648-653
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• 2001

구연산이 첨가된 0.01 M의 $\beta$-인산칼슘 용액을 수열처리 하여 휘스커 상 수산화아파타이트를 합성할 때 수열처리 온도 및 시간이 휘스커의 생성에 미치는 영향을 관찰하였다. 용액을 30$0^{\circ}C$에서 5시간 수열처리 할 때 c축으로 약 60-80$\mu\textrm{m}$까지 성장하고 비교적 순수한 휘스커를 얻을 수 있었으며 이렇게 합성된 수산화아파타이트 휘스커를 수산화아파타이트 시멘트에 1-2 wt% 첨가하였을 때 그 경화체의 직경인장강도는 약 4-6배까지 증가하였다.

• 한국식품영양과학회지
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• 제33권7호
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• pp.1092-1097
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• 2004

큰느타리버섯의 기능성 식품으로서 활용도를 높이기 위해 동결 건조된 자실체에서 분리한 조다당체 추출물이 면역세포 활성에 미치는 효과를 조사한 결과는 다음과 같다. 조다당체 추출물은 300 및 1,000 $\mu$g/mL 농도에서 비장세포의 증식을 유도하였으며, 이 때 비장세포는 IL-6와 IFN-${\gamma}$ 분비를 유도하는 것으로 나타났다 조다당체 추출물은 농도 의존적으로B세포의 증식을 유도하였으며, 특히 100 $\mu$g/mL농도 이상에서는B세포의 증식이 현저히 증가하는 것으로 나타났다. 그리고 조다당체 추출물 1,000 $\mu$g/mL 농도에서 B세포가 생산하는 IgGl, IgG2a, IgG3의 분비량이 현저히 증가하였다. 또한 농도 의존적으로 대식세포주의 일산화질소 생산을 유도하였으며, 대식세포가 분비하는 IL-6, TNF-$\alpha$, GM-CSF의 생산도 현저히 증가하는 것을 확인할 수 있었다.

• Journal of Applied Biological Chemistry
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• 제58권2호
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• pp.183-187
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• 2015

시호 추출물로부터 자외선에 의한 주름개선 효과를 확인하여 화장품 소재로서의 가능성을 검증하였다. 주름 활성 검증을 위하여 전자공여능, elastase, pro-collagen 생합성, Matrix metalloprotease-1 (MMP-1)의 활성을 측정하였다. 시호 추출물의 세포 독성을 측정하기 위하여 MTT assay를 하여 세포 독성이 100%에 가까운 농도인 5, 10, $50{\mu}g/mL$의 농도에서 pro-collagen 생합성과 MMP-1의 활성 검증하였다. 시호 추출물의 전자 공여능과 elastase 활성을 측정한 결과 $1,000{\mu}g/mL$의 농도에서 각각 80, 52%의 저해 활성을 가졌다. 또한 pro-collagen 생합성 역시 UVB를 조사한 후 시호 추출물을 농도 별로 처리 한결과 농도의존적으로 증가하는 것을 확인하였다. 주름생성에 관련되어져 있는 MMP-1의 발현을 알아본 결과 시호 추출물에 의해 total protein 양이 또한 감소되는 것을 확인 할 수 있었다. 따라서 시호는 주름활성을 개선시킬 수 있는 기능성 소재로 활용 될 수 있을것으로 사료된다.

• 한국분말재료학회지
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• 제6권3호
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• pp.215-223
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• 1999

The synthesis of $Ni_5Si_2,\;Ni_2Si$ and NiSi has been investigated by mechanical alloying (MA) of Ni-27.9at%Si, Ni-33.3at%Si and Ni-50.0at%Si powder mixtures. As-received and premilled elemental powders were subjected to MA. The as-received Ni powder was spherical and the mean particle size 48.8$\mu$m, whereas the premilled Ni powder was flaky and the mean particle diameter and thickness were found to be 125 and 5$\mu$m, respectively. The mean surface area of the premilled Mi powder particle was 3.5 times as large as that of the as-received Ni powder particle. The as-received Si powder was was 10.0$\mu$m. Self-propagating high-temperature synthesis (SHS) reaction, followed by a slow reaction (a solid state diffusion), was observed to produce each Ni silicide during MA of the as-received elemental powders. In other word , the reactants and product coexisted for a long period of MA of time. Only SHS reaction was, however, observed to produce each Ni silicide during MA of the premilled elemental powders, indicating that each Ni sillicide formed rather abruptly at a short period of MA time. The mechanisms and reaction rates for the formation of the Ni silicides appeared to be influenced by the elemental powder particle size and shape as well as the heat of formation of the products $(Ni_5Si_2$longrightarrow-43.1kJ/mol.at., $Ni_2Si$$\rightarrow$-47.6kJ/mol.at.).

• 한방안이비인후피부과학회지
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• 제28권1호
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• pp.32-40
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• 2015

Objectives : Hyaluronic acid(HA) is a mucopolysaccharide, occuring naturally in living organisms. It is one of the most hydrophilic molecules, so it has been known as being related to skin hydration and anti-aging. The purpose of this study is to examine the effects of Angelica acutiloba ethanol extract on hyaluronic acid synthesis. Methods : To determine cytotoxicity and hyaluronic acid synthase 2 gene expression, hyaluronic acid production in HaCaT cells, MTT assay and RT-PCR ELISA was used. Results : There was no cytotoxicity in $50{\mu}g/ml$ concentration Angelica acutiloba extract in MTT assay. Hyaluronic acid synthase 2(HAS2) gene expression was increased by all treated concentration Angelica acutiloba extract. Hyaluronic acid production was higher in $50{\mu}g/ml$ & $100{\mu}g/ml$ concentration Angelica acutiloba extract than control group. Conclusions : Hyaluronic acid production was increased by Angelica Acutiloba extracts. Therefore, We suggest that Angelica acutiloba can make a contribution to the moisturing effect on human skin. Conclusions : Hyaluronic acid production was increased by Angelica Acutiloba extracts. Therefore, We suggest that Angelica acutiloba can make a contribution to the moisturing effect on human skin.

• Journal of Acupuncture Research
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• 제23권2호
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• pp.91-102
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• 2006

Objectives : Ulmus davidiana Planch (UD) has long been known to have anti-inflammatory and protective effects on damaged tissue, inflammation and bone among other functions. Methods : This study was undertaken to address whether the water extract of the bark of UD could modulate proliferation of mouse osteoclasts in vitro and to investigate its effect on cyclooxygenase-2 (COX-2), which converts arachidonic acid to prostaglandin E2 (PGE2) and is highly expressed in osteoclasts. Mouse osteoclasts were tested in vitro for growth inhibition, proliferation cell nuclear antigen expression, and COX-2 activity and expression after treatment with UD extract. Results : Its effects were compared with those of indomethacin (a nonselective COX inhibitor) and celecoxib (a selective COX-2 inhibitor) by Cell viability assay, Cell cycle analysis, Immunohistochemical analysis of PCNA expression, Western blot analysis and PGE2 Enzyme immunoassay (EIA). UD demonstrated a strong growth inhibitory action in both tested osteoclasts cells. The IC50s were $10\;{\mu}g/ml$ for UD, $6\;{\mu}M$ for celecoxib and $42\;{\mu}M$ for indomethacin. UD, as well as celecoxib and indomethacin, suppressed proliferation cell nuclear antigen expression and PGE2 synthesis in osteoclasts. UD inhibited COX-2 expression, whereas celecoxib inhibited COX-2 activity directly. Conclusion : UD selectively and effectively inhibits osteoclasts cell growth in vitro. Inhibitory action of PGE2 synthesis via suppression of COX-2 expression may be responsible for its anti-inflammatory activity.

• 대한한방부인과학회지
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• 제24권4호
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• pp.10-19
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• 2011

Objectives: This study was performed to elucidate the effects of Kwibi-tang extract(KB) on dermal fibroblast. Methods: To demonstrate the effects of KB on dermal fibroblast, we used human dermal fibroblast(F6) and UVB light(30 $mJ/cm^2$) was used to damage to dermal fibroblast. we measured the nitrite production, LDH release in UVB-irradiated dermal fibroblast to elucidate the action-mechanism of KB. Also, we evaluated cell proliferation of dermal fibroblast and the amount of increased PICP, TIMP-1 in dermal fibroblast. Results: 1. KB decreased the cell proliferation of F6 dermal fibroblast in concentration of 50 ${\mu}g/ml$. 2. KB decreased the synthesis of PICP in concentration of 50 ${\mu}g/ml$. 3. KB decreased the synthesis of TIMP-1 in concentration of 50 ${\mu}g/ml$. 4. KB have no effect on the damage in UVB-irradiated F6 dermal fibroblast. Conclusions: From the results, we concluded KB decreases the cell proliferation and collagen synthesis in dermal fibroblast. So we suggest that KB has the anti-hyperplasy of dermal fibroblast.

• 동의생리병리학회지
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• 제33권5호
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• pp.267-274
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• 2019

This study aims to evaluate the effects of Shengmaisan (SMS) and three types of ShengmaisanJiaweifang on the inhibitory effect of melanin synthesis in B16F10 cells, the mechanism of action through tyrosinase, and the antioxidant effect through superoxide dismutase (SOD) activity. In this study, we used ShengmaisanJiaweifangs (SMS, SMSRR, SMSAD, SMSAR) to research the whitening effects in B16F10 cell lines. Shengmaisan (SMS) was a herbal medicine composed of Ginseng Radix, Liriopis Tuber, and Schisandrae Fructus. ShengmaisanJiaweifangs included SMSRR (SMS added with Rehmanniae Radix), SMSAD (SMS added with Asparagi Radix) and SMSAR (SMS added with Astragali Radix). We measured the cell viability, the inhibition rate of the melanin biosynthesis, and the activity of tyrosinase and SOD in malignant melanoma, B16F10 cells, to survey the whitening effect and the mechanism of the impact on the sample. As a result, SMSRR significantly suppressed the cell viability of B16F10 at more than $500{\mu}g/m{\ell}$ and significantly inhibited the generation of melanin induced by ${\alpha}$-MSH at more than $250{\mu}g/m{\ell}$. SMSRR ($500{\mu}g/m{\ell}$) decreased the activity of tyrosinase while increased the activity of SOD. Therefore, we considered that the SMSRR would be able to produce high value-added products more SMS if used as a commercial.

• 농약과학회지
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• 제2권1호
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• pp.24-31
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• 1998

천연물기원 신농약 개발을 위해 유용 식물자원 탐색 및 활성물질의 분리, 동정 결과 벼멸구 살충활성이 높고 분자구조상 유기합성이 용이한 것으로 판단되는 피마자잎중 활성물질 ricinine의 유도체 합성을 통해 고활성 화합물을 얻고자 하였다. 합성된 ricinine을 선도물질로 하여 활성을 증진하고자 분자구조 유사화합물을 비롯한 카바메이트계, 유기인계 화합물 12종을 합성하였다. 카바메이트계 유도체 합성시 전구물질의 pyridine 구조중 carbo기가 있는 chlororicinic acid, ricinic acid는 공명구조가 파괴되어 methyl isocyanate와 반응이 이루어지지 않았다. 유기인계 유도체의 경우 P에 O와 S가 결합된 oxon과 thiono형의 유도체를 합성한 결과 합성수율은 oxon형이 65% 이상인 반면에 thiono형은 20% 미만으로서 낮은 수율을 보였다. 합성 유도체의 생리활성 평가에 있어 유기인계 유도체는 oxon형보다 thiono형 화합물이 높은 살충효과를 나타냈다. Thiono형 유도체는 500 ${\mu}g/ml$ 수준에서 벼멸구에 대한 살충력이 모두 100%이었으며 점박이응애의 경우 특이적으로 thiono형 유도체중 alkyl기의 부분이 methyl인 경우 높은 활성을 나타냈다. Oxon형 유도체, 분자구조 유사화합물과 카바메이트계 유도체의 경우에는 살충력이 나타나지 않았다. 살균 활성은 pyridine ring의 2번 위치에 $NH_{2}$기가 있는 유도체의 경우 200 ${\mu}g/ml$ 수준의 실내검정에서 10종 병원균에 대해 $85{\sim}100%$의 생장저지효과를 보여주었으며, 온실검정에서도 250 ${\mu}g/ml$ 수준에서 벼도열병과 보리흰가루병에 대해 각각 92%, 86%의 방제효과를 나타냈다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.405-408
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• 1998

Generally, the principle function of simulator control loading system is to provide the pilot or student with the "feel" of the actual aircraft flight control systems during flight, taxing, and in malfunction. Flight control "feel" is the resistance felt by the pilot when moving a control stick or pedal, coupled with the amount of control surface deflection, and hence aircraft response, resulting from the input. Therefore, the control loading servo must be capable of performing to some general list of requirements derived from real aircraft control forces. In this paper, we deal with a $\mu-controller$ design for a control loading system of the flight simulator. For this, we derive a frequency response of the hydraulic system from the identification data and then design a controller using a $\mu-synthesis$ method. Under the same condition of simulation, $\mu-controller$ provides the superior performance than PID controller.than PID controller.