• 제목/요약/키워드: Scavenger

검색결과 543건 처리시간 0.035초

Antioxidative activity of compounds from cultivated Phellinus linteus

  • Jung, Eun-Joo;Yang, Ki-Sook
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.378.2-378.2
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    • 2002
  • Phellinus linteus has been used as anti-tumor and immuno stimulating agents in folk remedies. From precipitate of MeOH ex. by activited guided fractionation. 5.8-epidioxy ergosta-6.22-dien-3ol. palmitic acid. linoleic acid, and methyl linolate. 3.4-dihydroxybenzoic acid methylester and 4-(3'4'-Dihydroxyphenyl)-3-butene-2one were isolated. DPPH method was used to examine of antioxidative activity of the isolated compounds. As the result, 3.4-dihydroxybenzoic acid methylester, and phenolic compound. 4-(3'4'-Dihydroxyphenyl) -3-butene-2one were found to be a scavenger of 1,1-diphenyl-2-picrylhydrzyl radical. (omitted)

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H2O2로 유발된 뇌신경세포 상해에 대한 구진의 보호효과 (The protective effects of Moxi-tar on injury induced by H2O2 in C6-glioma)

  • 안성훈;구성태;김선영;김경식;손인철
    • Journal of Acupuncture Research
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    • 제21권3호
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    • pp.29-41
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    • 2004
  • Objective : This study was produced to examine the effects of moxibustion that had been played important role to traditional oriental medical treatment on disease. Recently, it was reported that moxi-tar which is generated in the process of moxibustion as burning combustibles decreased NO and iNOS generation in C6-glioma and RAW 264.7 cells in our lab. Methods : C6-glioma cells were cultured in RPMI 1640 with FBS 10% in CO2 incubator. To study the protective effects of moxi-tar, we observed cell viability, DPPH activity, SOD activity, catalase activity and cell morphology after injury with $H_2O_2$. Results and Conclusions : Moxi-tar increased cell viability about twice as much as that of being injury by $H_2O_2$(moxi-tar $40{\mu}g/m{\ell}$, $H_2O_2$ $500{\mu}M$). And the results of free radical scavenger activity($80{\mu}g/m{\ell}$ : $78.91{\pm}4.4%$), SOD activity and catalase activity($80{\mu}g/m{\ell}$ : 21.6unit/mg protein) were increased by moxi-tar as dose-dependent manner. So we concluded that the effects of moxibustion which is played important role in Oriental medicine, might be free radical scavenger effects induced by moxi-tar. Conclusion : These results indicate that tBHP induces apoptosis through a lipid peroxidation-dependent mechanism and JS exerts the protective effect against the apoptosis by preventing peroxidation of membrane lipids.

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Highly Reliable Triboelectric Rotational Energy Scavenger

  • Lee, Younghoon;Lee, Bada;Choi, Dukhyun
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.397-397
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    • 2016
  • Triboelectric nanogenerators (TENG) can produce power from ambient mechanical sources and have strong points of high output performance, light weight, low cost, and easy manufacturing process. It is expected that TENG can be utilized in the fields of wireless electronics and self-powered devices in the world which pays attention to healthcare and the IoT. In this work, we focus on scavenging ambient rotational energy by using a durably designed TENG. In previous studies regarding harvesting rotation mode energy, the devices were based on sliding mechanism and durability was not considered as a major issue. However friction by rotation causes reliability problems due to wear and tear. Therefore, in this study, we convert rotary motion to linear motion utilizing a cam by which we can then utilize contact-mode TENG and improve device reliability. In order to increase output performance, bumper springs were used below the TENG and the optimum value for the bumper spring constant was analyzed theoretically. Furthermore, the inserting a soft substrate was proposed and its effect on high output was determined to be due to an increase in the contact area. By increasing the number of cam noses, the output frequency was shown to increase linearly. For the purpose of maximum power transfer, the input impedance of the device was determined. Finally, to demonstrate the use of the C-TENG as a direct power source, it was installed on a commercial bicycle wheel and connected to 180 LEDs. In conclusion we present a rotational motion TENG energy scavenger system designed for enhanced durability and optimized output by appropriate choice of spring constants and substrate.

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MoSiA를 이용한 수전해용 공유가교 SPEEK/Cs-MoSiA/Ceria복합막의 제조 및 성능 연구 (Synthesis and Characterization of Covalently Cross-Linked SPEEK/Cs-substituted MoSiA/Ceria Composite Membranes with MoSiA for Water Electrolysis)

  • 서현;송유리;오연선;문상봉;정장훈
    • 한국수소및신에너지학회논문집
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    • 제26권6호
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    • pp.524-531
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    • 2015
  • To improve the electrochemical and mechanical characteristics, engineering plastic of the sulfonated polyether ether ketone (SPEEK) as polymer matrix was prepared in the sulfonation reaction of polyether ether ketone (PEEK). The SPEEK organic-inorganic blended composite membranes were prepared by sol-gel casting method. It was loaded with the highly dispersed ceria and cesium-substituted molybdosilicic acid (Cs-MoSiA) and 1,4-diiodobutane which was cross-linking agent contents of $10{\mu}L$. Cs-MoSiA was added to increase proton conductivity. Ceria ($CeO_2$) was used as a free radical scavenger which degrade the membrane in polymer electrolyte membrane water elctrolysis (PEMWE). In conclusion, CL-SPEEK/Cs-MoSiA/Ceria 1% composite membrane showed high proton conductivity 0.2104 S/cm at $25^{\circ}C$ which was better than Nafion 117 membrane.

시험관 및 생체조건하에서 니트로소프로린 생성에 미치는 수종 플라보노이드 화합물의 영향 (Influence of Some Flavonoids on N-Nitrosoproline Formation in vitro and in vivo)

  • Lee, Ji-Hyeon;Park, Jae-Sue
    • 한국식품영양과학회지
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    • 제22권3호
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    • pp.266-272
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    • 1993
  • 우리들의 식이중에 함유되어 있는 플라보노이드 화합물들이 니트로소화합물의 생성에 미치는 영향을 알아보기 위하여 생체내에서 일어나는 니트로소화 과정을 아질산염, 프로린과 시료를 동시에 투여하여 생성된 니트로소프로린 함량을 시험관 및 생체조건하에서 HPLC로서 측정하였다. 그 결과, 잘 알려진 ascorbic acid, KSCN과 더불어 catechin, chlorogenic acid, morin, luteolin, luteolin-7-O-glucoside, naringenin 등은 아질산염 소거에는 상당한 효과가 있는 것으로 나타났으나, 니트로소프로린 생성에 대해서는 ascorbic acid와 chlorogenic acid를 제외한 나머지 화합물들은 거의 영향을 미치지 않거나 오히려 그 생성을 촉진시키는 것으로 나타났다.

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간장조직의 활성산소 및 그 제거효소에 미치는 뽕잎 추출물의 영향 (Effects of Mulberry (Morus alba L.) Leaf Extract on Oxygen Radicals and Their Scavenger Enzymes in Liver of SD Rats)

  • 최진호;김대익;박수현;김정민;백영호;이희삼;류강성
    • 생명과학회지
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    • 제10권5호
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    • pp.504-510
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    • 2000
  • This study was designed to investigate the effects of mulberry (Morus alba L.) leaf extract (MLE) on oxygen radicals and their scavenger enzymes in liver membranes of rats. Sprague-Dawley (SD) male rats (160$\pm$10 g) were fed basic diet (control group), and experimental diets (MLE-100 and MLE-300 groups) added 100 and 300 mg/kg BW/day for 6 weeks. Hydroxyl radical (.OH) levels resulted in a significant decreases (15.2% and 18.1%, 5.6% and 8.0%, respectively) in liver mitochondria and microsomes could be not obtained. These are no significant differences in superoxide radical ($O_2$) levels of liver cytosol in MLE-100 and MLE-300 groups compared with control group. Lipid peroxide (LPO) levels were slightly decreased about 13.6% and 6.1% in liver mitochondria and microsomes of MLE-300 group compared with control group. Oxidized protein (OP) levels were remarkably decreased about 16.9% and 27.2% in liver microsomes only of MLE-100 and MLE-300 group compared with control group. Mn-SOD activities in liver mitochondria were remarkably increased (18.2% and 28.7%, respectively) in MLE-100 and MLE-300 groups, and Cu,Zn-SOD activities in liver cytosol were also significantly increased (11.3% and 20.2%, respectively) in MLE-100 and MLE-300 groups compared with control group. Mn-SOD activities in liver mitochondria were remarkably increased (18.2% and 28.7%, respectively) in MLE-100 and MLE-300 groups, and Cu,Zn-SOD activities in liver cytosol were also significantly increased (11.3% and 20.2%, respectively) in MLE-100 and MLE-300 groups compared with control group, but significant difference between GSHPx activities in liver cytosol could be not obtained. These results suggest that anti-aging effect of mulberry leaf extract (MLE) may play a pivotal role in attenuating a various age-related changes.

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Ferrocene-Based Diimine Pd(II) 촉매로 얻은 폴리(메틸메타크릴레이트)의 유리전이온도 (Glass Transition Temperature of Poly(methyl methacrylate) Obtained with Ferrocene-Based Diimine Pd(II) Catalyst)

  • 박태학;이동호;김태정;박동규
    • 폴리머
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    • 제26권3호
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    • pp.410-414
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    • 2002
  • 중심 금속을 안정화시킬 수 있는 ferrocene-based diimine 리간드를 가지고 낮은 산소 친화성을 가진 후전이금속인 Pd 촉매를 합성하여, 극성 단량체인 메틸메타크릴레이트 (MMA)의 중합에 사용하였다. 중합계 내의 impurity scavenger로 triisobutylaluminium (TIBA)를 사용하였을 때에, 중합온도와 [TIBA]/[Pd] 몰비가 생성 중합체(PMMA)의 수율 및 유리전이온도 ($T_g$)에 미치는 영향을 조사하였다. PMMA의 수율은 40~$50^{\circ}C$의 중합온도 및 2000~3000의 [TIBA]/[Pd] 몰비에서 가장 높았다. PMMA의 $T_g$는 중합온도에는 크게 영향을 받지 않으나, [TIBA]/[Pd] 몰비에 의존한다는 것을 관찰할 수 있었다. PMMA의 $T_g$의 변화를 PMMA의 미세구조와 연관시켜 조사한 결과, PMMA의 $T_g$ 이소탁틱도와 직선적 관계를 가짐을 알았다.

Uniconazole 및 Free Radical Scavenger처리가 양버즘나무의 $SO_2$ 피해경감에 미치는 효과 (Effect of Uniconazole and Free Radical Scavenger Treatments on Reduction of $SO_2$ Injury in Platanus occidentalis)

  • 조정희;구자형;최종명
    • 한국환경농학회지
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    • 제16권1호
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    • pp.14-18
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    • 1997
  • $SO_2$에 대한 양버즘나무의 내성을 증대시키고자 uniconazole, sodium benzoate 또는 ascorbic acid를 단용 또는 복합처리한 후 $SO_2$에 의한 가시피해정도, 엽록소함량 및 유리기 제거제로 활성산소의 독성을 중화시킬 수 있는 superoxide dismutase(SOD) 및 peroxidase(POD)의 활성변화를 조사하였다. Uniconazole처리에 의한 $SO_2$ 피해경감 효과는 SOD불활성제인 diethyldithiocarbamate(DDTC)를 다시 처리하므로써 가시피해가 증가하였고 SOD와 POD의 활성도 감소하였다. 유리기 제거제인 sodium benzoate와 ascorbic acid처리는 SOD나 POD 활성에 영향을 주지않으면서 $SO_2$의 피해를 경감시키고, DDTC의 $SO_2$피해증가 효과를 ascorbic acid 처리로 감소시킬 수 있었다. 이상의 결과로 미루어 uniconazole은 식물체내에서 산화방지물질의 역할을 하는 SOD의 활성을 증대시켜 $SO_2$가스의 피해를 경감시키는 효과가 인정되며, ascorbic acid와 sodium benzoate의 내성 증대 효과는 식물체내의 SOD나 POD 활성 증진과는 관계가 없는 것으로 판단된다.

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모르핀 정맥 투여시 척수 진통 작용 기전에 기여하는 Nitric Oxide (IV Morphine Produced Spinal Antinociception Partly by Nitric Oxide)

  • 송호경;박수석;김정태
    • The Korean Journal of Pain
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    • 제11권1호
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    • pp.1-6
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    • 1998
  • Background: The role of nitric oxide(NO) in analgesia from opioids is controversial. On the one hand, IV morphine analgesia is enhanced by IV injection of NO synthase inhibitors. On the other hand, IV morphine results in increased release of NO in the spinal cord. There have been no behavioral studies examining the interaction between IV morphine and intrathecal injection of drugs which affect NO synthesis. Method: Rats were prepared with chronic lumbar intrathecal catheters and were tested withdrawal latency on the hot plate after 3~5 days of surgery. Antinociception was determinined in response to a heat stimulus to the hind paw before and after IV injection of morphine, 2.5 mg/kg. Twenty minutes after morphine injection, rats received intrathecal injection of saline or the NO synthase inhibitors, L-NMMA or TRIM, the NO scavenger, PTIO, or the NO synthase substrate, L-Arginine. Intrathecal injections, separated by 15 min, were made in each rats and measurements were obtained every 5 min. Result: Mophine produced a 60~70% maximal antinociceptive response to a heat stimulus in all animals for 60 min in control experiments. Intrathecal injection of idazoxane decreased antinociception of IV morphine. The NO synthase inhibitors and the NO scavenger produced dose-dependent decreases in antinociceptive effect of morphine, whereas saline as a control group and L-Arginine as the NO substrate had no effect on antinociception of morphine. Conclusion: The present study supports the evidences that systemic morphine increase the nitrite in cerebrospinal fluid and dorsal horn. These data suggest that the synthesis of NO in the spinal cord may be important to the analgesic effect of IV morphine and increased NO in spinal cord has different action from the supraspinal NO.

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