• Title/Summary/Keyword: acid agent

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The mechanical and antimicrobial properties of chitosan crosslinked rayon fabric - Effect of chitosan and epichlorohydrin(ECH) concentration - (키토산 가교처리된 레이온 직물의 역학적특성과 항균성 - 에피클로로히드린과 키토산 농도의 영향 -)

  • Ahn, Jung-Mi;Kim, Min-Ji;Lee, Shin-Hee
    • Textile Coloration and Finishing
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    • v.18 no.6 s.91
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    • pp.16-24
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    • 2006
  • The purpose of this study is to improve the defects of chitosan crosslinked viscose rayon by ECH and to describe the change of hand of chitosan crosslinked viscose rayon fabrics. The chitosan crosslinked viscose rayon were manufactured by crosslinking process using ECH as crosslinking agent, 2 wt% aqueous acetic acid as a solvent of chitosan and ECH, and 20 wt% aqueous sodium hydroxide as crosslinking catalyst. Viscose rayon were first immersed in the pad bath of the mixed solution of chitosan and ECH, padded up to 100 wt% wet pick-up on weight of fiber(owf), precured on pin frames at $130^{\circ}C$ for 2 minutes, immersed in NaOH solution and finally wash and dry. Antimicrobial properties of the viscose rayon treated with chitosan were measured by the shake flask C.T.M. 0923 test method with staphylococcus aureus(ATCC 6538) as the microorganism. When the concentration of chitosan was increased chitosan crosslinked viscose rayon's LT, WT, B, 2HB and MIU were increased and G, 2HG, SMD, T and $T_m$ were decreased. On the other hand, WT, EM were decreased and RT was increased at $1{\times}10^{-2}M$ ECH. The optimum condition for crosslinking was that ECH concentration was between $1{\times}10^{-2}M\;and\;5{\times}10^{-2}M$. Antimicrobial effects of rayon fabric treated with chitosan was excellent.

Numerical Study on the Injector Shape and Location of Urea-SCR System of Heavy-duty Diesel Engine for Preventing $NH_3$ Slip (대형 디젤엔진용 SCR 시스템의 암모니아 슬립 억제를 위한 인젝터의 형상 및 위치에 관한 수치적 연구)

  • Jeong Soo-Jin;Lee Sang Jin;Kim Woo-Seung;Lee Chun Beom
    • Transactions of the Korean Society of Automotive Engineers
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    • v.14 no.1
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    • pp.68-78
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    • 2006
  • In the past few years, considerable efforts have been directed towards the further development of Urea-SCR(selective catalytic reduction) technique for diesel-driven vehicle. Although urea possesses considerable advantages over Ammonia$(NH_3)$ in terms of toxicity and handling, its necessary decomposition into Ammonia and carbon dioxide complicates the DeNOx process. Moreover, a mobile SCR system has only a short distance between engine exhaust and the catalyst entrance. Hence, this leads to not enough residence times of urea, and therefore evaporation and thermolysis cannot be completed at the catalyst entrance. This may cause high secondary emissions of Ammonia and isocyanic acid from the reducing agent and also leads to the fact that a considerable section of the catalyst may be misused for the purely thermal steps of water evaporation and thermolysis of urea. Hence the key factor to implementation of SCR technology on automobile is fast thermolysis, good mixing of Ammonia and gas, and reducing Ammonia slip. In this context, this study performs three-dimensional numerical simulation of urea injection of heavy-duty diesel engine under various injection pressure, injector locations and number of injector hole. This study employs Eulerian-Lagrangian approach to consider break-up, evaporation and heat and mass-transfer between droplet and exhaust gas with considering thermolysis and the turbulence dispersion effect of droplet. The SCR-monolith brick has been treated as porous medium. The effect of location and number of hole of urea injector on the uniformity of Ammonia concentration distribution and the amount of water at the entrance of SCR-monolith has been examined in detail under various injection pressures. The present results show useful guidelines for the optimum design of urea injector for reducing Ammonia slip and improving DeNOx performance.

Effect of Phellinus baumii -Biotransformed Soybean Powder on Lipid Metabolism in Rats

  • Kim, Dae Ik;Kim, Kil Soo;Kang, Ji Hyuk;Kim, Hye Jeong
    • Preventive Nutrition and Food Science
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    • v.18 no.2
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    • pp.98-103
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    • 2013
  • In this study, we evaluated the hypolipidemic and antioxidative effects of biotransformed soybean powder (BTS; Phellinus baumii-fermented soybean) on lipid metabolism in rats. Sprague-Dawley (SD) male rats were divided into basal diet group (BA), high fat diet group (HF), high fat diet containing 10% BTS group (10 BTS), and high fat diet containing 20% BTS group (20 BTS). Changes in the content of various isoflavones, including daidzein and genistein, within the soybean after fermentation to BTS were investigated. The levels of daidzein and genistein were $149.28{\mu}g/g$ and $364.31{\mu}g/g$, respectively. After six weeks experimental period, Food efficiency ratio in the 10 and 20 BTS group was significantly lower than the HF group (P<0.05). Total serum levels of cholesterol, triglycerides, low-density lipoprotein cholesterol, and atherogenic index ratio in the 10 or 20 BTS group were significantly lower than the HF group. The levels of alanine aminotransferase, aspartate aminotransferase and thiobarbituric acid reactive substance were significantly lower in the groups that received 10% and 20% BTS than the HF. The activities of SOD and CAT were significantly higher in the 10 and 20 BTS group than the HF group. The activity of XO in the 10 and 20 BTS group was significantly lower than in the HF group by 20% and 23%, respectively. In conclusion, these data suggest that BTS is an effective agent in improving lipid metabolism and antioxidant enzyme system.

Rpi-blb2 Gene-Mediated Late Blight Resistance in Plants

  • Oh, Sang-Keun
    • 한국균학회소식:학술대회논문집
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    • 2015.11a
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    • pp.26-26
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    • 2015
  • Phytophthora infestans is the causal agent of potato and tomato late blight, one of the most devastating plant diseases. P. infestans secretes effector proteins that are both modulators and targets of host plant immunity. Among these are the so-called RXLR effectors that function inside plant cells and are characterized by a conserved motif following the N-terminal signal peptide. In contrast, the effector activity is encoded by the C terminal region that follows the RXLR domain. Recently, I performed in planta functional profiling of different RXLR effector alleles. These genes were amplified from a variety of P. infestans isolates and cloned into a Potato virus X (PVX) vector for transient in planta expression. I assayed for R-gene specific induction of hypersensitive cell death. The findings included the discovery of new effector with avirulence activity towards the Solanum bulbocastanum Rpi-blb2 resistance gene. The Rpi-blb2 encodes a protein with a putative CC-NBS-LRR (a coiled-coil-nucleotide binding site and leucine-rich repeat) motif that confers Phytophthora late blight disease resistance. We examined the components required for Rpi-blb2-mediated resistance to P. infestans in Nicotiana benthamiana. Virus-induced gene silencing was used to repress candidate genes in N. benthamiana and to assay against P. infestans infections. NbSGT1 was required for disease resistance to P. infestans and hypersensitive responses (HRs) triggered by co-expression of AVRblb2 and Rpi-blb2 in N. benthamiana. RAR1 and HSP90 did not affect disease resistance or HRs in Rpi-blb2-transgenic plants. To elucidate the role of salicylic acid (SA) in Rpi-blb2-mediated resistance, we analyzed the response of NahG-transgenic plants following P. infestans infection. The increased susceptibility of Rpi-blb2-transgenic plants in the NahG background correlated with reduced SA and SA glucoside levels. Furthermore, Rpi-blb2-mediated HR cell death was associated with $H_2O_2$, but not SA, accumulation. SA affects basal defense and Rpi-blb2-mediated resistance against P. infestans. These findings provide evidence about the roles of SGT1 and SA signaling in Rpi-blb2-mediated resistance against P. infestans.

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Synthesis and Characterization of Waterborne Polyurethanes Based on Isophorone Diisocyanate and Mixed Polyols of Poly(tetramethylene glycol)/Polydimethylsiloxane Diol (이소포론 디이소시아네이트와 폴리(테트라메틸렌 글리콜)/폴리디메틸실록산 디올 혼합 폴리올을 사용한 수분산성 폴리우레탄의 합성과 특성 분석)

  • Lee, Ji Hye;Hong, Seongdon;Kim, Young Ho
    • Polymer(Korea)
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    • v.37 no.2
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    • pp.167-176
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    • 2013
  • Linear and cross-linked waterborne polyurethanes (WPUs) based on isophorone diisocyanate and mixed diols of poly(tetramethylene glycol)/hydroxyethyl-terminated polydimethylsiloxane (PDMS-OH) were synthesized with dimethylol propionic acid as an anionic component, trimethylolpropane as a cross-linking agent, and butanediol as a chain extender and characterized. The hydrophobicity, $T_g$, stress-strain behaviors of the linear or cross-linked siloxane-containing WPU (WPU-Si) films with different PDMS content were analyzed by using water contact shape analyzer, energy dispersive spectrometer, dynamic mechanical analyzer, and universal testing machine. The results reveal that as the PDMS content increased, the hydrophobicity of WPU-Si films increased, $T_g$ moved to higher temperature, the breaking stress increased, and the breaking strain decreased.

The Effects of Schizandrae Fructus Chloroform Fraction on Gene Expression in Liver Tissue of Dyslipidemic Mice (오미자(五味子) 클로로포름 분획물이 이상지질혈증 생쥐의 지질대사 및 간 조직 유전자 변화에 미치는 영향)

  • Shin, Yoon Ri;Kim, Young Kyun;Kim, Kyoung Min
    • Journal of Korean Medicine for Obesity Research
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    • v.15 no.2
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    • pp.111-122
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    • 2015
  • Objectives: Schizandrae fructus (Schizandra chinensis) is one of very common herbs, it is known as natural antioxidants, anti-inflammatory agent. Also some reports show that its extract works to regulate of dyslipidemia. This study was designed to investigate the effects of Schizandrae fructus chloroform fraction (SFCF) on serum lipid levels in dyslipidemic mice. Methods: The levels of total cholesterol, high density lipoprotein-cholesterol, triglyceride, aspartate aminotransferase (AST), alanine aminotransferase (ALT), fasting blood glucose in serum were measured. Histopathological and gene expression changes in liver tissue were also observed. Results: Oral administration of SFCF lowered levels of total cholesterol and triglyceride, which were elevated by high-fat diet. But SFCF did not affect on weight changes and serum AST, ALT levels in dyslipidemic mice. After carrying out gene ontological analysis, large numbers of genes in high-fat diet group were up-(347) or down-regulated (235). In SFCF treated mice, some changed expression of the genes was restored to normal levels, with a recovery rate of 17%. And it seems that fatty acid biosynthesis pathway was one of important key pathways to recovery. Conclusions: SFCF has beneficial effect on dyslipidemia, and could be used to prevent and treat cardiovascular disease.

Screening of Traditional Medicines for Antioxidative and Anti-proliferative Effects on Rat Mesangial Cells (한약재 추출물의 항산화 및 사구체혈관간세포 증식 억제활성 탐색)

  • Sohn, Eun-Hwa;Jang, Seon-A;Woo, Han Goo;Koo, Hyun Jung;Han, Hyo-Sang;Kang, Se Chan
    • Korean Journal of Plant Resources
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    • v.26 no.5
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    • pp.652-657
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    • 2013
  • In the present study, anti-oxidative and the RMC proliferation inhibitory propeties of 80% ethanol extracts from 63 kinds of traditional medicines were investigated. Inhibitory effects of RMC proliferation were showed that Dalbergia odorifera T. Chen., Melia azedarach Linn$\acute{e}$ and Hydnocarpus anthelmintica Pierre. Among them Hydnocarpus anthelmintica Pierre had the highest anti-oxidative activity ($ORAC_{PE\;value}=1.6$, DPPH = 81.1), but Dalbergia odorifera T. Chen. and Melia azedarach Linn$\acute{e}$ had no effects. These results suggest that the Hydnocarpus anthelmintica Pierre could prevent or protect from kidney disease as antioxidant and anti-proliferative agent for RMC.

Fermentation Characteristics of Grape Yakju made with Three Kinds of Grape (포도 종류를 달리한 포도 약주의 발효 특성)

  • Lee, Ji-Yeon;Kwak, Eun-Jung
    • Journal of the East Asian Society of Dietary Life
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    • v.19 no.1
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    • pp.96-104
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    • 2009
  • Three kinds of grape yakju (Kyoho, Campbell and Moru) and grape-free control were fermented with rice using koji of Aspergillus kawachii as a fermenting agent, and their fermentation characteristics were investigated. For the three yakju, reducing sugar content decreased slowly over 2 days fermentation after an initial rapid decrease. In case of Brix, the reducing sugar content increased gradually after increasing rapidly during the first 2 days of fermentation. The Kyoho and Moru groups displayed a gradual increase in reducing sugar content after an initial 2-day decrease, and the sugar content of the Campbell group increased gradually during fermentation. Uniformly, pH increased gradually after an initial 2-day decrease, however total acid increased continuously throughout fermentation. Alcohol content of yakju showed almost no change after increasing until day 6 (Kyoho) of day 4 (others), with the control displaying the highest content. Control $\alpha$-amylase activity decreased gradually after an initial 2-day increase, while that of the three yakju decreased throughout fermentation. Activities of $\beta$-amylase activities paralleled the results of reducing sugar. Concerning total anthocyanin, the Moru and Campbell groups displayed a rapid increase until day 2, a decrease until day 12, and a gradual increase thereafter. While the Kyoho and control groups displayed virtually no change after an initial 2-day increase until day 12, after which a gradual increase also occurred. In concerning sensory evaluation, Moru yakju scored highest for violetness, flavor of grape, and sweet taste, and also displayed a low alcohol content. These attributed Moru yakju the preferred choice.

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Water-soluble ginseng oligosaccharides protect against scopolamine-induced cognitive impairment by functioning as an antineuroinflammatory agent

  • Xu, Ting;Shen, Xiangfeng;Yu, Huali;Sun, Lili;Lin, Weihong;Zhang, Chunxiao
    • Journal of Ginseng Research
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    • v.40 no.3
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    • pp.211-219
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    • 2016
  • Background: Panax ginseng root is used in traditional oriental medicine for human health. Its main active components such as saponins and polysaccharides have been widely evaluated for treating diseases, but secondary active components such as oligosaccharides have been rarely studied. This study aimed to assess the impact of water-soluble ginseng oligosaccharides (WGOS), which were isolated from the warm-water extract of Panax ginseng root, on scopolamine-induced cognitive impairment in mice and its antineuroinflammatory mechanisms. Methods: We investigated the impact of WGOS on scopolamine-induced cognitive impairment in mice by using Morris water maze and novel object recognition task. We also analyzed the impact of WGOS on scopolamine-induced inflammatory response (e.g., the hyperexpression of proinflammatory cytokines IL-$1{\beta}$ and IL-6 and astrocyte activation) by quantitative real-time polymerase chain reaction and glial fibrillary acid protein (GFAP) immunohistochemical staining. Results: WGOS pretreatment protected against scopolamine-induced learning and memory deficits in the Morris water maze and in the novel object recognition task. Furthermore, WGOS pretreatment downregulated scopolamine-induced hyperexpression of proinflammatory cytokines interleukin (IL)-$1{\beta}$ and IL-6 mRNA and astrocyte activation in the hippocampus. These results indicate that WGOS can protect against scopolamine-induced alterations in learning and memory and inflammatory response. Conclusion: Our data suggest that WGOS may be beneficial as a medicine or functional food supplement to treat disorders with cognitive deficits and increased inflammation.

Effect of dentin treatment on proliferation and differentiation of human dental pulp stem cells

  • Park, Minjeong;Pang, Nan-Sim;Jung, Il-Young
    • Restorative Dentistry and Endodontics
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    • v.40 no.4
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    • pp.290-298
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    • 2015
  • Objectives: Sodium hypochlorite (NaOCl) is an excellent bactericidal agent, but it is detrimental to stem cell survival, whereas intracanal medicaments such as calcium hydroxide ($Ca[OH]_2$) promote the survival and proliferation of stem cells. This study evaluated the effect of sequential NaOCl and $Ca(OH)_2$ application on the attachment and differentiation of dental pulp stem cells (DPSCs). Materials and Methods: DPSCs were obtained from human third molars. All dentin specimens were treated with 5.25% NaOCl for 30 min. DPSCs were seeded on the dentin specimens and processed with additional 1 mg/mL $Ca(OH)_2$, 17% ethylenediaminetetraacetic acid (EDTA) treatment, file instrumentation, or a combination of these methods. After 7 day of culture, we examined DPSC morphology using scanning electron microscopy and determined the cell survival rate with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. We measured cell adhesion gene expression levels after 4 day of culture and odontogenic differentiation gene expression levels after 4 wk using quantitative real-time polymerase chain reaction. Results: DPSCs did not attach to the dentin in the NaOCl-treated group. The gene expression levels of fibronectin-1 and secreted phosphoprotein-1 gene in both the $Ca(OH)_2$- and the EDTA-treated groups were significantly higher than those in the other groups. All $Ca(OH)_2$-treated groups showed higher expression levels of dentin matrix protein-1 than that of the control. The dentin sialophosphoprotein level was significantly higher in the groups treated with both $Ca(OH)_2$ and EDTA. Conclusions: The application of $Ca(OH)_2$ and additional treatment such as EDTA or instrumentation promoted the attachment and differentiation of DPSCs after NaOCl treatment.