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        검색결과 58

        21.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 기능성과 친환경 화장품에 대한 관심이 증가하고 있으며, 이에 따라 안전하면서 효능이 우수한 식물 추출물을 활용한 소재 개발이 이루어지고 있는 실정이다. 따라서 본 연구에서도 주로 건강 기능성 소재로써 다양한 효능이 있는 것으로 알려진 그라비올라 추출물이 기능성 화장품 소재로써의 가 능성을 확인하고자 하였다. 그라비올라 추출물의 항산화 활성을 확인하고자 총 폴리페놀과 총 플라보노 이드 함량, DPPH radical 소거 활성을 측정하였고, HDF 세포에서의 세포 독성을 확인한 후 적정 농도 에서 HDF 세포에 과산화수소(H2O2)를 처리하여 산화적 스트레스에 대한 ROS 활성 억제 효과와 세포 보호 효과를 측정하였다. 본 실험 결과, 그라비올라 추출물은 항산화 지표가 되는 총 폴리페놀과 플라보 노이드의 100g당 26.6 mg(CA)/100g, 14.3 mg(CA)/100g의 높은 함량을 확인하였으며, 높은 radical 소 거 활성을 확인하였다. HDF 세포에 대한 세포 생존율을 측정한 결과, 모든 농도에서 유의한 세포 독성 이 나타나지 않았으며, 추후 100 μg/mL 농도에서 실험하였다. H2O2로 유도된 HDF 세포에 ROS 활성 억제를 측정한 결과, 농도 의존적인 ROS 활성 억제 효과를 확인하였고, H2O2를 4 시간, 24 시간, 48 시간 동안 처리 후 그라비올라 추출물의 세포 보호 효과를 측정한 결과, 25 μg/mL 농도에서 24시간까 지 89.92%의 높은 세포 보호 효과를 확인하였다. 이와 같은 결과를 통하여 그라비올라 추출물은 항산 화 활성이 우수하고, HDF 세포에 대한 독성이 거의 없으며, H2O2에 의해 발생하는 활성산소에 대한 효과적인 활성 억제 효과와 세포 보호 효과가 우수한 것으로 확인됨에 따라 항산화 및 세포 보호 효과 를 가진 다양한 기능성 소재로서의 가능성을 확인하였다.
        4,000원
        22.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to evaluate the protective effect of PineXol® on H2O2-induced cell death in SK-N-MC cells, and in early stage focal ischemia rodent model. SK-N-MC cells were pre-treated with 200 μM H2O2 or various concentrations of PineXol® (10, 30, and 50 pg/mL) for 24 h, and then exposed to H2O2 for 3 h. Cell death was assessed by the CCK-8 assay, reactive oxygen species (ROS) assay, and lactate and dehydrogenase (LDH) release assay. Superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) expressions were also analyzed by western blotting. Focal ischemia rodent model was used as the in vivo model, and different concentrations of PineXol® (1, 10, and 100 mg/kg) were administered. One week after administration, reduction of infarct volume was analyzed by TTC staining. Cell viability of H2O2-treated SK-N-MC cells significantly increased by pre-treatment of PineXol® (p<0.05). PineXol® pre-treatment also induced significant decrease of ROS and LDH expressions. However, PineXol® did not affect the infarct volume. These results suggest that PineXol® has significant neuroprotective effect in vitro, but statistical significance was not confirmed in the in vivo focal ischemia mo
        4,000원
        23.
        2015.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Edaravone (Eda) is a potent scavenger of inhibiting free radicals including hydroxyl radicals (H2O2). Reactive oxygen species (ROS) such as H2O2 can alter most kinds of cellular molecules such as lipids, proteins and nucleic acids, cellular apoptosis. In addition, oxidative stress from over-production of ROS is involved in the defective embryo development of porcine. Previous study reported that Eda has protective effects against oxidative stress-like cellular damage. However, the effect of Eda on the preimplantation porcine embryos development under oxidative stress is unclear. Therefore, in this study, the effects of Eda on blastocyst development, expression levels of ROS, and apoptotic index were first investigated in preimplantation porcine embryos. After in vitro fertilization, porcine embryos were cultured for 6 days in PZM medium with Eda (10 μM), H2O2 (200 μM), and Eda+H2O2 treated group, respectively. Rate of blastocyst development was significantly increased (P<0.05) in the Eda treated group compared with only H2O2 treated group. And, we measured intracellular levels of ROS by DCF-DA staining methods and investigated numbers of apoptotic nuclei by TUNEL assay analysis is in porcine blastocyst, respectively. Both intracellular ROS levels and the numbers of apoptotic nucleic were significantly decreased (P<0.05) in porcine blastocysts cultured with Eda (10 μM). More over, the total cell number of blastocysts were significantly increased (P<0.05) in the Eda-treated group compared with untreated group and the only H2O2 treated group. Based on the results, Eda was related to regulate as antioxidant-like function according to the reducing ROS levels during preimplantation periods. Also, Eda is beneficial for developmental competence and preimplantation quality of porcine embryos. Therefore, we concluded that Eda has protective effect to ROS derived apoptotic stress in preimplantation porcine embryos.
        4,000원
        24.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to evaluate the chemical quenching system for residual ozone and to determine the operating condition for the quenching system. Hydrogen peroxide (H₂O₂) and sodium thiosulfate (Na₂S₂O₃) were investigated as quenching reagents for ozone removal, and the tendency of each chemical was notably different. In the case of H₂O₂, the degradation rate of ozone was increased as the concentration of H₂O₂ increase, and temperature and pH value have a significant effect on the degradation rate of ozone. On the other hand, the degradation rate of ozone was not affected by the concentration of Na₂S₂O₃, temperature and pH value, due to the high reactivity between the S₂O₃²- and ozone. This study evaluates the decomposition mechanism of ozone by H₂O₂ and Na₂S₂O₃ with consideration for the water quality and reaction time. Furthermore, the removal test for the quenching reagents, which can be remained after reaction with ozone, was conducted by GAC process.
        4,200원
        25.
        2015.02 구독 인증기관 무료, 개인회원 유료
        Benzene was oxidized by binary oxidants composed of nitric acid and hydrogen peroxide at 80℃. The product obtained was analyzed with gas chromatograph-mass spectrometer. Eight high value compounds, 2-nitrophenol, 2-chloro-6-nitrophenol, 4-chloro-2- nitrophenol, 2-chloro-4-nitrophenol, 2,4-dinitrophenol, 4-nitrophenol, 2,6-dinitrophenol and 2-chloro-4,6-dinitro-phenol were found, which they have high contents in the range from 4.28% to 32.52%. These compounds are very widely used in organic synthesis. e.g., synthesizing dye, medicines and chemical reagents, pesticide, explosive, polymer, etc.
        3,000원
        26.
        2013.12 구독 인증기관 무료, 개인회원 유료
        HyPer is the genetically encoded biosensor of intracellular hydrogen peroxide (H2O2), the most stable of the reactive oxygen species (ROS) generated by living cells. HyPer has a high sensitivity and specificity for detecting intracellular H2O2 by confocal laser microscopy. However, it was not known whether high speed ratiometric imaging of H2O2 by HyPer is possible. We thus investigated the sensitivity of HyPer in detecting changes to the intracellular H2O2 levels in HEK293 and PC12 cells using a microfluorometer imaging system. Increase in the HyPer ratio were clearly evident on stimulations of more than 100 μM H2O2 and fast changes in the HyPer ratio were observed on ratiometric fluorescent images after H2O2 treatment. These results suggest that HyPer is a potent biosensor of the fast temporal production of intracellular H2O2.
        4,000원
        27.
        2012.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Though hydrogen peroxide (H2O2) causes a deleterious effect to cells with its reactive oxygen species resulting in cell death, S-allyl cysteine (SAC, a bioactive organosulfur compound of aged garlic extract) has been known to have a cytoprotective effect. Few reported profiles of gene expression of H2O2 and SAC treated human cord blood derived mesenchymal stem cells (MSC). This study revealed changes in the profile of twenty-one genes grouped by oxidative stress, antioxidant, cell death, anti-apoptosis and anti-aging by quantitative real time PCR. A concentration of 100μM of SAC or 50μM of H2O2 was applied to MSC which show moderate growth and apoptosis pattern. H2O2 treatment enhanced expression of eleven genes out of twenty-one genes compared with that of control group, on the contrary SAC suppressed expression of eighteen genes out of twenty-one genes except C ros oncogene. SAC decreased expression of oxidative stress genes such as SOD1, CAT and GPX. These results seemed consistent with reports which elucidated over expression of NF-kB by H2O2, and suppression of it by SAC. This study will confer basic information for further experiments regarding the effects of SAC on gene levels.
        4,000원
        28.
        2011.02 구독 인증기관 무료, 개인회원 유료
        We have accomplished a various reaction experiment for a purifying agent selection which is related with efficient site demobilization about soil contaminated with the total petroleum hydrocarbon(TPH) in link of contaminated soil purification enterprise of power train center in Y railway car places of business for an oxidizer comparison experiment, we have differed consistency and implantation quantity of the hydrogen peroxide (H2O2). The result showed the highest 98.8% removal ratio, when H2O2 is 35% consistency. In the same way, the result which implants at 1:1 ratio (hydrogen peroxide (H2O2) : the catalyst (FeSO4 ․7H2O)) showed a similar result, when only the hydrogen peroxide was implanted.
        4,000원
        29.
        2009.12 구독 인증기관 무료, 개인회원 유료
        Antioxidants partially ameliorated the detrimental effects of reactive oxygen species (ROS) on sperm characteristics during in vitro storage. The objective of the present study was to investigate the single or synergetic antioxidative effect of curcumin and Vit. E on the characteristics of fresh boar sperm during in vitro storage. The sperm viability in curcumin, Vit. E supplementation and curcumin+Vit. E+H2O2 groups remained over 85.0% in 3 hr incubation period, but in 6 hr incubation period, curcumin+Vit. E+H2O2 groups was sharply dropped than those of curcumin and Vit. E group. The membrane intergrity in all evaluated groups except for H2O2 group did not significantly difference in 3 hr incubation period. The viability in curcumin or Vit. E supplementation were significantly increased than in curcumin+H2O2 and Vit. E+H2O2 group in 6 hr incubation period. The percentage of mitochondrial activity and acrosome intergrity obtained similar trends within same incubation periods irrespective of treatment. The lipid peroxidation of spermatozoal plasma membrane ranged from 11.6∼17.5 nM/l×106 and 14.0∼ 19.0 nM/l×106 in 3 hr and 6 hr incubation periods. In conclusion, curcumin or Vit. E rpplementation alone or cooperatively improved sperm viability index (motility, membrane intergrity, viability and survival rates) and fertility index (mitochondria activity, acrosome intergrity and lipid peroxidation) of fresh boar sperm, indicating that curcumin and Vit. E have a antioxidative properties through its scavenging activity against hydrogen peroxide.
        4,000원
        30.
        2009.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 파프리카 재배농가에서 과산화수소를 이용하여 여름철 고온극복에 관한 연구수행 결과이다. 고온기 과산화수소(순도 30%)를 0.3%로 희석하여 5일주기로 살포한 결과 파프리카의 엽이 두꺼워지고 기공저항 속도가 낮아 순조로운 증산작용이 가능하였다. 주당 착과수는 무처리에 비하여 약 2개가 많았다. 또한 과산화수소처리에 따라 엽내 과산화수소량이 증가하는 경향이었고, 항산화효소인 catalase와 peroxidase의 활력이 증가되었다. 여름철 파프리카 재배에서 가장 많이 발생하는 흰가루병 방제를 위하여 농약사용이 불가피한 상황이지만 생산물의 농약잔류 등으로 사용에 많은 제한이 있는 현 상황에서 과산화수소의 주기적인 이용으로 흰가루병을 방제할 수 있고 생산량도 높일 수 있어 금후 파프리카 재배농가의 많은 이용이 기대 된다.
        4,000원
        34.
        2007.12 구독 인증기관 무료, 개인회원 유료
        The superficial dorsal horn, particularly substantia gelatinosa (SG) in the spinal cord, receives inputs from small-diameter primary afferents that predominantly convey noxious sensation. Reactive oxygen species (ROS) are toxic agents that may be involved in various neurodegenerative diseases. Recent studies indicate that ROS are also involved in persistent pain through a spinal mechanism. In the present study, whole cell patch clamp recordings were carried out on SG neurons in spinal cord slice of young rats to investigate the effects of hydrogen peroxide on neuronal excitability and excitatory synaptic transmission. In current clamp condition, tert-buthyl hydroperoxide (t-BuOOH), an ROS donor, depolarized membrane potential of SG neurons and increased the neuronal firing frequencies evoked by depolarizing current pulses. When slices were pretreated with phenyl-N-tert-buthylnitrone (PBN) or ascorbate, ROS scavengers, t-BuOOH did not induce hyperexcitability. In voltage clamp condition, t-BuOOH increased the frequency and amplitude of spontaneous excitatory postsynaptic currents (sEPSCs), and monosynaptically evoked excitatory postsynaptic currents (eEPSCs) by electrical stimulation of the ipsilateral dorsal root. These data suggest that ROS generated by peripheral nerve injury can modulate the excitability of the SG neurons via pre- and postsynaptic actions.
        4,000원
        35.
        2007.10 KCI 등재 구독 인증기관·개인회원 무료
        Previous in vi tro studies demonstrated that H202 or carbamide peroxide cou ld penetrate i nto pul p chambers through enamel and dentin (Benetti et a l., 2004; G okay et a l. , 2004‘ Suli eman et al .. 2005) ‘ Recently. Lee et al.(2006) demonstrated that H20Z enhanced the diffe rentiation of odontoblast like cell line, whereas it inhibited osteogenic diffe rentiation in pre 。steobl astic cell line, as seen by its efl"ecLs on an early difï"erentiation marker. ALP activity. I-lowever. the effects of HZ02 have not been well elucidated in primary cultured human pulp cells ln th is study‘ we investigated whether HO- 1 is involved in H20 2-induced cytotoxicity and examined the production 0 1" dent in sia lophosphoprotein (DSPP) and other minera li zation markers, in human pulp cells H20Z dec1'eased cell viabili ty. but increased HO-l and DSPP expression in a concentra t ion and time dependent manner. Inhibitors of guanylate cyclase, PI3K. ERK, and p38 MAP kinase blocked J-!?,0 2- induced cytot oxicity and the expression of HO-1 and DSPP mRNAs in pulp cells. These data suggest that t he induction of HO-l by H202 in pu lp cells plays a protective role against the cytotoxic effects of H202 and stimulates DSPP expression. resulting in prematu re oclontoblast differentiation th rough pathways t hat involve cGMP. p38. ancl ERK
        36.
        2007.04 KCI 등재 구독 인증기관·개인회원 무료
        Al though the changes in tooth morphology and hardness by hydrogen peroxide(H20 z) have been r‘epor‘.ted .‘ the pαr。o야t뻐ec야tive role of heme oxygenase-l(HO-l) against the cytotoxic effects of H202 has not been clarifïed i n human pulp cells ln this st udy. we investigated whether HO-l is involved in Hz0 2-induced cytoLox icity a nd examined the production 0 1' dentin sia lophosphoprotein(DSPP) and other mineralization markers‘ in hllman pu lp cells H202 decreased cell viabi lity, but increased HO-l and DSPP expression in a concentra tion and time dependent manner . Inhibitors of gllanylate cyclase. PI3K, ERK. and p38 MAP kinase blocked H202-indllced cytotoxicity and the expression of HO-l and DSPP mRNAs in pulp cells. These data suggest that the induction of HO-l by H202 in plllp cells plays a protective role against the cytotoxic effects 0 1' HzOz and stimulates DSPP expression‘ reslllting in prematllre odontoblast dilTerentiation throllgh pathways that involve cGMP‘ p38. and ERK.
        37.
        2006.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This studies were carried out in summer season to increase high temperature tolerance using hydrogen peroxide treatments on cucumber in greenhouse. The water stress of cucumber in greenhouse by the hydrogen peroxide treatments showed as control〉250 mM〉500 mM treatments in order. The photosynthesis rate of cucumber at 30℃ did not show difference with each hydrogen peroxide treatment in temperature controlled greenhouse. However, the photosynthesis rate of cucumber in the control and hydrogen peroxide treatments at 40℃ was significantly different. The photosynthesis rate of cucumber in combined treatment with 1,000 mg·L-1 CO2 supply and hydrogen peroxide was also higher than control, however, there was no different of photosynthesis in 250 mM and 500 mM treatment. The value of Fv/Fm and Fm/Fo of chlorophyll fluorescent in 500 mM hydrogen peroxide treatment at 40℃ was highest. Also the activity of POD, the antioxidant enzyme, was higher with high hydrogen peroxide concentration than the other treatments. The high temperature limits for growth were 43℃ in the control, 44℃ in the 250 mM and 46℃ in the 500 mM according to analyze chlorophyll fluorescent Fo. The high temperature tolerance in cucumber increased approximately 3℃ by the hydrogen peroxide treatments under this experiment conditions.
        4,000원
        38.
        2005.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Carbonization products C1, C2, C3, C4 and C5 were prepared by the carbonization of date pit in limited air, at 500, 600, 700, 800 and 1000℃, respectively. C1-V-600, C3-V-600, C1-V-1000 and C3-V-1000 were prepared by thermal treatment of C1 and C3 under vacuum at 600 and 1000℃. The textural properties were determined from nitrogen adsorption at 77 K and from carbon dioxide adsorption at 298 K. The surface pH, the FTIR spectra and the acid and base neutralization capacities of some carbons were investigated. The amounts of surface oxygen were determined by out-gassing the carbon-oxygen groups on the surface as CO2 and CO. The adsorption of water vapor at 308 K on C1, C2, C3 and C4 was measured and the decomposition of H2O2 at 308 K was also investigated on C1, C2, C3, C4 and C5. The surface area and the total pore volume decreased with the rise of the carbonization temperature from 500 to 1000℃. The adsorption of water vapor is independent on the textural properties, while it is related to the amount of acidic carbon-oxygen groups on the surface. The catalytic activity of H2O2 decomposition does not depend on the textural properties, but directly related to the amount of basic carbon-oxygen complexes out-gassed as CO, at high temperatures.
        4,000원
        39.
        1998.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        홍삼의 추출물인 50% ethanol extract, crude saponin, 그리고 lipid soluble fraction이 마우스 대식세포의 oxidative burst를 유발할 수 있는지 여부를 알아보고자 in vitro와 in vivo에 각각의 추출물을 처치하고 hydrogen peroxide 생산을 DCFH-DA를 이용한 형광분광광도법으로 측정하였다. 형광분광법에 의한 hydrogen peroxide의 측정을 최적화하기 위한 DCFH-DA의 농도는 3.2 μM이었고, oxidative burst를 유발하지 못하였지만, zymosan A로 유발한 경우에는 50% ethanol extract에서 가장 높은 hydrogen peroxide를 생산하였다. In vivo 실험에서는, lipid soluble extract에서만 유의하게 증가한(P<0.01) oxidative burst를 유발하였고, ginsenoside(saponin)가 어느 정도 포함되어 있는 50% ethanol extract와 crude saponin은 대조군에 비하여 유의하게 낮은(P<0.05) hydrogen peroxide를 생산하였다. 이는 ginsenoside가 마우스의 nitric oxide 생산을 억제한다는 다른 연구자들의 보고와 일치하는 결과이다. Oxidative burst를 유발한 lipid soluble extract에는 phenol계 화합물, polyacetylene계 화합물, 미량선분 등이 함유되어 있으므로 차후 연구를 통하여 과연 어느 성분이 hydrogen peroxide를 증가시키는지를 규명하는 것이 필요하다.
        4,000원
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