• Title/Summary/Keyword: reducing agents

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Studies on the Bleaching Efficiency in Newsprint Using Formamidine Sulfinic Acid

  • Choi, Won-Jung;Kim, Hyoung-Jin
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2006.06b
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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.

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Tin-Based Nanoparticles Prepared by a Wet Chemical Synthesis using Green Reducing and Capping Agents (화학적 습식 합성법에서 친환경 슈거 환원제 및 젤라틴 캡핑제에 의한 주석계 나노입자의 제조)

  • Chee, Sang-Soo;Yun, Young-En;You, Eun-Sun;Park, Sang-Hyun;Park, Sung-Young;Lee, Seok-Hee;Park, In-Seon;Lee, Jong-Hyun
    • Journal of the Microelectronics and Packaging Society
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    • v.19 no.4
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    • pp.25-31
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    • 2012
  • In the synthesis of nanoparticles (NPs) via wet chemical reduction using tin(II) acetate precursor, the effects of green reducing agents (sugar) and a capping agent (gelatin) on the formation of NPs were analyzed as functions of synthesis conditions and time. When glucose was used as the reducing agent, it was observed that irregular chainlike shapes, aggregates of NPs, were formed during the synthesis at $70-110^{\circ}C$. The NPs were determined as $SnO_2$ from the fast Fourier transform (FFT) pattern. In the synthesis at $110^{\circ}C$ by using sucrose, fine spherical NPs of ~10 nm in diameter were formed after the synthesis time of 3 h. As the time increased to 9 h, the chainlike NP aggregates besides irregularly aggregated spherical NPs were also formed locally. However, the chainlike NP aggregates were only observed when the synthesis was conducted at $130^{\circ}C$. The spherical NPs and chainlike NP aggregates were analyzed to be pure Sn and $SnO_2$, respectively.

Comparative Study of Enzyme Activity and Stability of Bovine and Human Plasmins in Electrophoretic Reagents, β-mercaptoethanol, DTT, SDS, Triton X-100, and Urea

  • Choi, Nack-Shick;Hahm, Jeung-Ho;Maeng, Pil-Jae;Kim, Seung-Ho
    • BMB Reports
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    • v.38 no.2
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    • pp.177-181
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    • 2005
  • Effects of common electrophoretic reagents, reducing agents ($\beta$-mercaptoethanol [BME] and DTT), denaturants (SDS and urea), and non-ionic detergent (Triton X-100), on the activity and stability of bovine plasmin (b-pln) and human plasmin (h-pln) were compared. In the presence of 0.1% SDS (w/v), all reagents completely inhibited two plns, whereas SDS (1%) and urea (1 M) denatured plns recovered their activities after removal of SDS by treatment of 2.5% Triton X-100 (v/v). However, reducing agents (0.1 M of BME and DTT) treated plns did not restore their activities. Based on a fibrin zymogram gel, five (from b-pln) and four (from h-pln) active fragments were resolved. Two plns exhibited unusual stability in concentrated SDS and Triton X-100 (final 10%) and urea (final 6 M) solutions. Two bands, heavy chain-2 (HC-2) and cleaved heavy chain-2 (CHC-2), of b-pln were completely inhibited in 0.5% SDS or 3 M urea, whereas no significant difference was found in h-pln. Interestingly, 50 kDa (cleaved heavy chain-1, CHC-1) of b-pln and two fragments, 26 kDa (light chain, LC) and 29 kDa (microplasmin, MP), of h-pln were increased by SDS in a concentration dependent manner. We also found that the inhibition of SDS against both plns was reversible.

Effect of Thiol-reducing Agents and Antioxidants on Sulfasalazine-induced Hepatic Injury in Normotermic Recirculating Isolated Perfused Rat Liver

  • Heidari, Reza;Esmailie, Neda;Azarpira, Negar;Najibi, Asma;Niknahad, Hossein
    • Toxicological Research
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    • v.32 no.2
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    • pp.133-140
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    • 2016
  • Sulfasalzine is a widely administered drug against inflammatory-based disorders in human. However several cases of liver injury are associated with its administration. There is no stabilized safe protective agent against sulfasalazine-induced liver injury. Current investigation was designed to evaluate if N-acetylcysteine (NAC) and dithioteritol (DTT) as thiol reducing agents and/or vitamins C and E as antioxidants have any protective effects against sulfasalazine-induced hepatic injury in an ex vivo model of isolated rat liver. Rat liver was canulated and perfused via portal vein in a closed recirculating system. Different concentrations of sulfasalazine and/or thiol reductants and antioxidants were administered and markers of organ injury were monitored at different time intervals. It was found that 5 mM of sulfasalazine caused marked liver injury as judged by rise in liver perfusate level of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) (p < 0.05). A significant amount of lipid peroxidation and hepatic glutathione depletion were detected in drug-treated livers, accompanied with significant histopathological changes of the organ. Administration of NAC ($500{\mu}M$), DTT (${400\mu}M$), Vitamin C ($200{\mu}M$), or vitamin E ($200{\mu}M$) significantly alleviated sulfasalazine-induced hepatic injury in isolated perfused rat liver. The data obtained from current investigation indicate potential therapeutic properties of thiol reductants and antioxidants against sulfasalazine-induced liver injury.

Study on the Development of Practical Application of Indigo Dyes (실용화를 위한 쪽 염료의 관한 연구)

  • Lee, Sang-Phil;Kim, Soon-Hee
    • The Research Journal of the Costume Culture
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    • v.19 no.3
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    • pp.612-621
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    • 2011
  • The process of making or cultivating indigo dyes is very cumbersome and complex. The dye extraction and dyeing methods using general plant dye, moth repellent dye, fast acting natural dye, and other dyes are very different. This research investigates the extraction of indigo dye and liquid dye extraction of polygonum(indigo) plants using calcium oxide water. While extracting indigo dye the concentration of purified indigo dye may be controlled by adjusting the pH level. Due to the various uses of dyes the adjustment of surface color must be considered. In regard to the change according to different concentrations of reducing agents, it was found that cotton fabrics and ramie fabrics show the highest color difference at 0.4% and 0.3% respectively. As the reduction temperature increases, the color difference increases as well. The maximum color difference was found to appear at $90^{\circ}C$. Cotton fabrics and ramie fabrics showed 70.55 and 67.01 respectively. The color difference increases as the concentration of dyes increases, but at a concentration of 300%, cotton fabrics was found to show 6.22PB in H value using the Munsell color system, containing purple and blue color. The pH of the polygonum dyes extracted through this experiment were adjusted by adding calcium oxide to the experimental water, without directly adding calcium oxide to the liquid polygonum extract. In a refine state, it was mixed with polygonum extract to extract a more refine and highly concentrated indigo dye. When lye and reducing agents are added to extracted indigo dye and sealed for long-term storage, it can be effective and easily used for dyeing.

Purification and Enzymatic Properties of Myrosinase in Korean Mustard Seed(Brassica juncea) (한국산 겨자중 Myrosinase의 정제 및 효소학적 특성)

  • 신창식;서권일;강갑석;안철우;김용관;심기환
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.25 no.4
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    • pp.687-694
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    • 1996
  • Myrosinase was purified from Korean mustard seed(Brassica juncea) by a sequential process of DEAE-cellulose, concanavalin A-sepharose, and Superose 6 chromatography. The molecular weight of puri-fied myrosinase(II-2) determined by SDS-polyacrylamide electrophoresis was 67KD. About a 248-fold purification for myrosinase II-2 was obtained after Superose 6 chromatography. Optimum pH of the myrosinase was 7.0 and optimum temperature of the enzyme was $3^{\circ}C.$ The enzyme was stable at pH 7.0, and below $30^{\circ}C.$ Cu, Hg and Fe ion significantly inhibited the enzyme activity, but ascorbic acid enhanced, resulting in a maximum activity by 1mM ascorbic acid. Among tile ascorbic acid ana-logues, dehydroascorbic acid inhibited the enzyme activity, whereas others showed a little effect. Reducing agents such as 2-mercaptoethanol and dithiothreitol inhibited the enzyme activity, but the reducing agents with ascorbic acid was enhanced enzyme activity.

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Antioxidative Properties of Brown Algae Polyphenolics and Their Perspectives as Chemopreventive Agents Against Vascular Risk Factors

  • Kang, Keejung;Park, Yongju;Hwang, Hye-Jeong;Kim, Seong-Ho;Lee, Jeong-Gu;Shin, Hyeon-Cheol
    • Archives of Pharmacal Research
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    • v.26 no.4
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    • pp.286-293
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    • 2003
  • Several polyphenolic compounds and complex mixtures were isolated from brown algae species. The 1,1-diphenyl-2-picryhydarzyl (DPPH) radical scavenging activity and ferric reducing antioxidant power (FRAP) of these compounds were evaluated to determine their physiological usefulness as antioxidants for vascular protection. The antioxidative protection of low-density lipoprotein (LDL) was also evaluated and compared with that of catechin, because the generation of oxidized LDL is one of the most active and specific risk factors contributing to atherogenesis. Oral administration to rats of a commercially available sample ($VNP^{TM}$) containing 30% of these polyphenolic compounds and 70% dietary fiber revealed that the serum reducing capacity measured in terms of FRAP value was significantly elevated 30 min after the treatment, but declined rather quickly thereafter, indicating the good oral absorption of the compounds and their fast binding to the lumenal surface of the blood vessels. An eight-week, human, clinical trial (n=31) of $VNP^{TM}$ showed significant improvement in erectile function measured by IIEF (international index of erectile function) score. These results collectively demonstrated the usefulness of these polyphenolic compounds as fundamental chemopreventive agents against vascular risk factors originating from oxidative stress.

Effects of Korean Red Ginseng marc with aluminum sulfate against pathogen populations in poultry litters

  • Chung, Tae Ho;Park, Chul;Choi, In Hag
    • Journal of Ginseng Research
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    • v.39 no.4
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    • pp.414-417
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    • 2015
  • Background: The aim of this study was to evaluate the effects of Korean Red Ginseng marc with aluminum sulfate as litter amendments on ammonia, soluble reactive phosphorus, and pathogen populations in poultry litters. Methods: Increasing levels of Korean Red Ginseng marc with aluminum sulfate were applied onto the surface of rice hull as a top-dress application; untreated rice hulls served as controls. Results: Treatment with Korean Red Ginseng marc with aluminum sulfate or aluminum sulfate alone resulted in lower litter pH (p < 0.05), as compared with that of the controls. There were some differences (p < 0.05) between treatments with Korean Red Ginseng marc with aluminum sulfate or aluminum sulfate alone and controls at 2-4 wk (not at 1 wk). Ammonia levels reduced on an average by 29%, 30%, and 32% for 10 g, 20 g Korean Red Ginseng marc with aluminum sulfate, and aluminum sulfate alone, respectively, as compared with controls at 4 wk. During the experiment, Korean Red Ginseng marc with aluminum sulfate or aluminum sulfate treatment had an effect (p < 0.05) on soluble reactive phosphorus content, as compared with the controls (not at 4 wk). A decrease in Salmonella enterica and Escherichia coli was observed (p < 0.05) in litter amended with both Korean Red Ginseng marc with aluminum sulfate and aluminum sulfate alone, as compared with the control, except at 1-3 wk for Salmonella enterica and 1 wk and 4 wk for Escherichia coli, respectively. Conclusion: The results showed that using Korean Red Ginseng marc with aluminum sulfate (blends), which act as acidifying agents by reducing the pH of the litter, was equally effective as aluminum sulfate in reducing the environmental impact.

The comparison clinical study effect of Diode Laser & Ms coat usage for dentinal hypersensitivity following Periodontal therapy (치주치료 후 지각과민 감소를 위한 다이오드 레이저와 Ms coat 처치 직후 임상적 효과 비교)

  • Choi, Hyun-Bok;Hong, Ki-Seok;Chung, Chin-Hyung;Lim, Sung-Bin
    • Journal of Periodontal and Implant Science
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    • v.37 no.2
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    • pp.201-208
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    • 2007
  • The purpose of this study was to evaluate the effect of diode laser & desensitizing agents to overcome hypersensitizing root surfaces problem after periodontal treatment. 20 patients(60 teeth) presented were volunteered in this study. Diode laser & MS coat was respectively applied on hypersensitizing root surfaces after periodontal treatments. Following application they were evaluated immediately. The results were as follows: 1. The frequency and degree of root surface hypersensitivity levels were measured by the sequence of tactile and air stream. 2. Reduction of root surfaces hypersensitivity by tactile were for Diode laser and Ms coat application respectively $3.0294{\pm}2.0224$ and $3.2692{\pm}1.6139$. 3. Reduction of root surfaces hypersensitivity by air stream were for Diode laser and Ms coat apapplication respectively $3.0294{\pm}2.0224$ and $2.2692{\pm}1.6139$. 4, It could be said that Diode Laser and Ms coat application were significantly effective in reducing dentin hypersensitivity as far as concerned effect, Ms coat applicatio showed more effective than Diode laser. In conclusion, both methods were significantly effective in reducing dentinal hypersensitivity. Therefore, it was recommended that Diode laser and desensitizing agents could be used routinely for patients dentinal hypersensitivity following periodontal treatment.

A Study on the Removal of Air Pollutants Using Oxidants and Microbubbles (산화제와 마이크로버블을 이용한 대기오염물질 제거)

  • Kyung-bo Ku;Hyuk-Ku Kwon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.31 no.3
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    • pp.93-102
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    • 2023
  • This study investigated the possibility of treating heavy metal pollutants existing in the air in addition to simultaneously removing NOx and SOx by injecting oxidizing and reducing agents into a scrubber into a microbubble device to create an eco-friendly method that does not generate secondary pollutants. Lead compound (Pb) was selected as the heavy metal substance in the air to be treated with microbubbles, and the removal efficiency was confirmed. By treating microbubbles by connecting them to a scrubber, it was confirmed that not only NOx and SOx but also heavy metal substances in the air were reduced, cost was reduced, and secondary environmental pollutants were not generated. Through this study, it was possible to simultaneously remove NOx, SOx, and heavy metals at low cost by applying an eco-friendly method, rather than the existing high-cost treatment method such as SCR. If oxidizing agent, reducing agent, and microbubbles are used appropriately, economical and efficient air pollution can be achieved. Since material processing was possible, it is expected to be helpful in the technological development of environmental prevention facilities.