• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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• pp.381-386
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• 2006

Many different types of bleaching chemicals and processes have been globally used for deinked pulp. Besides chlorine-free bleaching chemicals, hydrogen peroxide, and sodium dithionite that could be used without restriction for almost all types of fibers, chlorine-containing chemicals such as chlorine dioxide and sodium hypochlorite have also used throughout the world. Even though hydrogen peroxide is commonly used in newsprint, it could not effectively increase brightness. Experimental evaluation on the possibility of using formamidine sulfinic acid (FAS), a reducing agent, for bleaching a wood-containing deinked pulp has been carried out in this study. The effect of bleaching efficiency for FAS on operational conditions and chemical concentrations compaired to hydrogen peroxide in one and two stages was studied. FAS bleaching showed higher brightness at high temperature and low consistency, and vice versa for peroxide one. Bleaching with sodium silicate and DTPA in FAS and peroxide stage showed better results than cases without them. Sodium silicate and chelant seemed minimize the influence of transition metal ions, including manganese and iron ions, which induce both bleaching agents to decompose. As a result, FAS as a reducing agent seems more effective than hydrogen peroxide for increasing brightness and reducing yellowness. FAS and FAS sequence seemed more efficient than the other two stages of bleaching sequences with regard to the best brightness level obtained. When bleaching was conducted with FAS, COD load was just about one-third compared to peroxide, and brightness stability of the bleached pulp appeared better than peroxide after UV light irradiation.

• Restorative Dentistry and Endodontics
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• 제49권2호
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• pp.14.1-14.13
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• 2024

This study aimed to answer the question through a systematic review: Can carbamide peroxide be as effective as hydrogen peroxide and cause less in-office bleaching sensitivity? A literature survey was performed in PubMed/MEDLINE, Embase, Scopus, ISI Web of Science, and gray literature. Primary clinical trials that compared the efficacy or the in-office bleaching sensitivity between carbamide and hydrogen peroxides were included. The risk of bias was evaluated using the RoB2. The certainty of the evidence was assessed using the GRADE approach. DPI training significantly improved the mean scores of the dental undergraduates from 7.53 in the pre-DPI-training test to 9.01 in the post-DPI-training test (p < 0.001). After 6 weeks, the mean scores decreased marginally to 8.87 in the retention test (p = 0.563). DPI training increased their confidence level from 5.68 pre-DPI training to 7.09 post-DPI training. The limited evidence suggests that the 37% carbamide peroxide may be similarly effective to the 35% hydrogen peroxide for bleaching teeth in-office and causes less bleaching sensitivity. However, more well-designed split-mouth clinical trials are necessary to strengthen the evidence.

• 대한한방내과학회지
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• 제22권4호
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• pp.557-565
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• 2001

Objectives : This study was carried out to examine toxic effect of Sintongchukeo-tang on cultured mouse spinal sensory neurons inhibited by neurotoxicity induced by hydrogen peroxide. Methods : MTT assay, NR assay, LDH and neurofilament assay were performed after spinal sensory neurons were preincubater with various concentrations of Sintongchukeo-tang water extract before treatment of cells with hydrogen peroxide. Results : Hydrogen peroxide induced ceil degeneration such as the decrease of cell viability was measured by MTT and NR assay in the cultured mouse spinal sensory neurons. Sintongchukeo-tang water extract was effective in the decrease of LDH activities of neurons produced by hydrogen peroxide. Sintongchukeo-tang water extract was effective in the increase of amount of neurofilaments damaged by hydrogen peroxide. Conclusions : From the above results, it is suggested that hydrogen peroxide induces the inhibition of cell viability in cultured mouse spinal sensory neurons and Sintongchukeo-tang water extract was effective in cultured neurons damaged by hydrogen peroxide.

• 대한본초학회지
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• 제38권6호
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• pp.45-52
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• 2023

Objectives : Effects of baicalein (BA) on oxidative stress in RAW 264.7 mouse macrophages stimulated with peptidoglycan (PG) and lipopolysaccharide (LPS) were investigated. Methods : RAW 264.7 co-stimulated with LPS and PG were incubated with BA at concentrations of 25 and 50 µM. Incubation time was 18 h, 20 h, 22 h, 24 h, and 26 h. After incubation, the production of hydrogen peroxide in RAW 264.7 was measured with dihydrorhodamine 123 assay. Additionally, RAW 264.7 stimulated with PG were incubated with BA at concentrations of 25 and 50 µM for 24 h. After incubation, NO production was evaluated by griess reagent assay. Results : BA significantly inhibited hydrogen peroxide productions (p <0.05). In details, production of hydrogen peroxide in 'LPS and PG'-stimulated RAW 264.7 treated for 18 h with BA at concentrations of 25 and 50 µM was 91.27% and 89.22% of the control group treated with LPS and PG only, respectively; the production of hydrogen peroxide for 20 h was 92.19% and 90.58%, respectively; production of hydrogen peroxide for 22 h was 91.69% and 89.89%, respectively; production of hydrogen peroxide for 24 h was 92.4% and 90.19%, respectively; production of hydrogen peroxide for 26 h was 91.7% and 89.04%, respectively. Additionally, BA at the concentration of 50 and 100 µM significantly inhibited NO production in PG-induced RAW 264.7 (p <0.05). Conclusions : BA might have anti-oxidative activity related to its inhibition of hydrogen peroxide production in 'LPS and PG'-stimulated RAW 264.7 macrophages.

• 동의생리병리학회지
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• 제22권6호
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• pp.1495-1499
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• 2008

The purpose of this study is to investigate the effect of water extract from Artemisiae Argi Folium (WAAF) on hydrogen peroxide production within mouse macrophage Raw 264.7 Cells treated with gallic acid, EtOH, LPS, and acetaminophen. WAAF (0${\sim}$400 ug/mL) was treated with gallic acid, EtOH, LPS, acetaminophen. And the intracellular productions of hydrogen peroxide were measured by dihydrorhodamine 123 (DHR) assay. WAAF showed the restoration of the intracellular productions of hydrogen peroxide which were reduced by gallic acid, EtOH, LPS, and acetaminophen in Raw 264.7 Cells. WAAF could be supposed to have the immunological activity related with macrophage's oxidative burst.

• Biotechnology and Bioprocess Engineering:BBE
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• 제9권4호
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• pp.256-260
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• 2004

Melanin was decolorized by lignin peroxidase from Phanerochaete chrysosporium. This decolorization reaction showed a Michaelis-Mentens type relationship between the decolorization rate and concentration of two substrates: melanin and hydrogen peroxide. Kinetic constants of the decolorization reaction were 0.1 OD$\sub$475//min ($V_{max}$) and 99.7 mg/L ($K_{m}$) for melanin and 0.08 OD$\sub$475//min ($V_{max}$) and 504.9 ${\mu}$M ($K_{m}$) for hydrogen peroxide, respectively. Depletion of hydrogen peroxide interrupted the decolorization reaction, indicating the essential requirement of hydrogen peroxide. Pulsewise feeding of hydrogen peroxide continued the decolorizing reaction catalyzed by lignin peroxidase. These results indicate that enzymatic decolorization of melanin has applications in the development of new cosmetic whitening agents.

• 동의생리병리학회지
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• 제23권2호
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• pp.438-442
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• 2009

The purpose of this study is to investigate the effect of water extract from Artemisiae Argi Folium Fermented with Lactobacillus pentosus (AFL) on hydrogen peroxide production within mouse macrophage Raw 264.7 Cells treated with gallic acid, EtOH, Nicotine, Acetaminophen, and Acetaldehyde. AFL (0${\sim}$400 ug/mL) was treated with gallic acid, EtOH, Nicotine, Acetaminophen, and Acetaldehyde. And the intracellular productions of hydrogen peroxide were measured by dihydrorhodamine 123 (DHR) assay. AFL showed the restoration of the intracellular productions of hydrogen peroxide which were reduced by gallic acid, EtOH, Nicotine, Acetaminophen in Raw 264.7 Cells. AFL could be supposed to have the immunological activity related with macrophage's oxidative burst.

• 동의생리병리학회지
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• 제23권3호
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• pp.608-612
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• 2009

The effect of Sacchromyces cerevisiae-Fermented Artemisiae Argi Folium Water extract (AFS) on hydrogen peroxide production within mouse macrophage Raw 264.7 Cells treated with EtOH, gallic acid, Nicotine, Acetaminophen, and Acetaldehyde was investigated through this study. AFS (0-400 ug/mL) was simultaneously treated with EtOH, gallic acid, Nicotine, Acetaminophen, and Acetaldehyde. And the intracellular productions of hydrogen peroxide were measured by dihydrorhodamine 123 (DHR) assay. AFS restorated the intracellular productions of hydrogen peroxide reduced by EtOH, gallic acid, Nicotine, Acetaminophen within Raw 264.7 Cells. AFS could be supposed to have the immunological activity concerned with macrophage's oxidative burst.

• 동의생리병리학회지
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• 제24권1호
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• pp.96-101
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• 2010

The purpose of this study is to investigate the effect of water extract from Artemisiae Argi Folium Fermented with Sacchromyces cerevisiae (AFS) on hydrogen peroxide production within human hepatocyte HepG2 cells treated with gallic acid, EtOH, nicotine, acetaminophen, and acetaldehyde. AFS (0~400 ug/mL) was treated with gallic acid, EtOH, nicotine, acetaminophen, and acetaldehyde. And the intracellular productions of hydrogen peroxide were measured by dihydrorhodamine 123 (DHR) assay. AFS showed the restoration of the intracellular productions of hydrogen peroxide which were reduced by gallic acid, EtOH, nicotine, acetaminophen, and acetaldehyde in HepG2 Cells. AFS could be supposed to have the hepatoprotective effect related with hepatocytologic signaling activity against gallic acid, EtOH, nicotine, acetaminophen, and acetaldehyde.

• 한국치위생학회지
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• 제8권4호
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• pp.11-18
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• 2008

The purposes of this study were to examine the effect of 35% Carbamide Peroxide(CP) bleaching agent on the changes in physical and chemical characteristics of tooth. The effect of bleaching agent on enamel was analyzed using Hardness test, SEM and EDS. The microhardness between bleached groups after bleaching showed statistically significant difference according to the paired t-test. The bleached enamel surface showed apparent morphological changes compared to the enamel, which was stored in distilled water only. The difference of the total mineral contents for the distilled water and Carbamide Peroxide did not show statistical significance. These results demonstrated that bleaching using 35% Carbamide Peroxide were adversely affects application time of experimental group and may the safety of using these agents for a short time in dentist-monitored bleaching.