• Title/Summary/Keyword: solvent-resistance

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A Study for Direct Application of Drug on Oral Mucosa (구강점막에서 약물의 직접적용을 위한 연구)

  • Jeong, Sung-Hee;Ok, Soo-Min;Huh, Joon-Young;Ko, Myung-Yun;Ahn, Yong-Woo
    • Journal of Oral Medicine and Pain
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    • v.35 no.4
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    • pp.229-235
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    • 2010
  • A common method for treating oral mucosal diseases is taking medication by oral administration. The oral administration is the method of least resistance. Because large part of drugs is degraded by liver, it is necessary to take more drugs getting to appropriate level in blood stream. And there are so many side effects when patients take drugs by oral administration. In so many cases, the patients who suffer from oral mucosal problems have the other general diseases simultaneously. Willingly or not, some patients can't take the medicine by oral administration. Number of topical drugs for oral mucosal disease is less than that for skin diseases because the environment of oral mucosa prevents activity of medicine. In this paper, research on effects of topical type medication for treating oral mucosal diseases is conducted through investigating currently used medications and their effects. In addition, effects of dissolved oral medications with appropriate solvent are demonstrated if this medication is useful for patients clinically.

Dietary Aloe Vera Gel Powder and Extract Inhibit Azoxymethane-induced Colorectal Aberrant Crypt Foci in Mice Fed a High-fat Diet

  • Chihara, Takeshi;Shimpo, Kan;Kaneko, Takaaki;Beppu, Hidehiko;Higashiguchi, Takashi;Sonoda, Shigeru;Tanaka, Miyuki;Yamada, Muneo;Abe, Fumiaki
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.2
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    • pp.683-687
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    • 2015
  • Aloe vera gel exhibits protective effects against insulin resistance as well as lipid-lowering and anti-diabetic effects. The anti-diabetic compounds in this gel were identified as Aloe-sterols. Aloe vera gel extract (AVGE) containing Aloe-sterols has recently been produced using a new procedure. We previously reported that AVGE reduced large-sized intestinal polyps in Apc-deficient Min mice fed a high fat diet (HFD), suggesting that Aloe vera gel may protect against colorectal cancer. In the present study, we examined the effects of Aloe vera gel powder (AVGP) and AVGE on azoxymethane-induced colorectal preneoplastic aberrant crypt foci (ACF) in mice fed a HFD. Male C57BL/6J mice were given a normal diet (ND), HFD, HFD containing 0.5% carboxymethyl cellulose solution, which was used as a solvent for AVGE (HFDC), HFD containing 3% or 1% AVGP, and HFDC containing 0.0125% (H-) or 0.00375% (L-) AVGE. The number of ACF was significantly lower in mice given 3% AVGP and H-AVGE than in those given HFD or HFDC alone. Moreover, 3% AVGP, H-AVGE and L-AVGE significantly decreased the mean Ki-67 labeling index, assessed as a measure of cell proliferation in the colonic mucosa. In addition, hepatic phase II enzyme glutathione S-transferase mRNA levels were higher in the H-AVGE group than in the HFDC group. These results suggest that both AVGP and AVGE may have chemopreventive effects on colorectal carcinogenesis under the HFD condition. Furthermore, the concentration of Aloe-sterols was similar between 3% AVGP and H-AVGE, suggesting that Aloe-sterols were the main active ingredients in this experiment.

Electrochemical Properties of PVdF Gel Polymer Electrolyte with Plasticizer for Lithium/sulfur Battery (리튬 유황 전지용 PVdF 겔 고분자 전해질의 가소제에 따른 전기화학적 특성 평가)

  • Ryu, Ho-Suk;Kim, Jong-Seon;Kim, Dong-Ju;Kim, Dong-Yeon;Kim, Ic-Pyo;Ahn, Hyo-Jun;Kim, Ki-Won;Ahn, Jou-Hyeon;Lee, Gun-Hwan
    • Journal of the Korean Electrochemical Society
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    • v.10 no.3
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    • pp.213-218
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    • 2007
  • In order to find out proper PVdF gel polymer electrolyte for Li/S battery, we investigated PVdF gel polymer electrolytes with various glyme type plasticizer such as polyglyme, tetraglyme, triglyme. The organic solvents as triglyme, tetraglyme, polyglyme (Mn = 250, 500) has different chain length of ethylene oxide(EO) in solvent of glyme system. ionic conductivity decreased as increasing chain length of EO in plasticizers. Ionic conductivity of PVdF gel electrolyte with tetraglyme, triglyme, polyglyme (Mn = 250, 500) at room temperature was $5{\times}10^{-4},\;3{\times}10^{-4},\;6{\times}10^{-5},\;3{\times}10^{-5}\;S/cm$, respectively. Li/S cell with PVdF gel polymer electrolyte using tetraglyme plasticizer had low interfacial resistance and the highest initial discharge capacity of 1232 mAh/g of active sulfur, which was about 70% utilization of theoretical value.

Anticancer Potential of Cratoxylum formosum Subsp. Pruniflorum (Kurz.) Gogel Extracts Against Cervical Cancer Cell Lines

  • Promraksa, Bundit;Daduang, Jureerut;Khampitak, Tueanjit;Tavichakorntrakool, Ratree;Koraneekit, Amonrat;Palasap, Adisak;Tangrassameeprasert, Roongpet;Boonsiri, Patcharee
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.14
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    • pp.6117-6121
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    • 2015
  • Background: Most northeast Thai vegetables may play roles in human health by acting as antioxidant and anticancer agents. Recent study showed that Cratoxylum formosum subsp. pruniflorum (Kurz.) Gogel. (Teawdang) could inhibit growth of liver cancer cell lines. Cervical cancer, which has human papilloma virus as its main cause, is found at high incidence in Thailand. Due to increasing drug resistance, searches for potential anticancer compounds from natural source are required. Therefore, our purpose was to evaluate the cytotoxicity of Teawdang extracts in cervical cancer cell lines. Materials and Methods: Teawdang edible parts, purchased from Khon Kaen market during July-October 2013 was extracted with organic solvent. Phenolic profiles of crude hexane (CHE), ethyl acetate (CEE), methanol (CME) and water (CWE) extracts were performed by high performance liquid chromatographic (HPLC) techniques. Their cytotoxic effects on cervical cancer cells were investigated with HPV-non infected (C-33A) and HPV-infected (HeLa and SiHa) cell lines. Results: HPLC profiles showed that all crude extracts contained caffeine, ferulic acid and resveratrol. CME and CEE had high contents of gallic acid and quercetin. Catechin was found only in CWE. Cytotoxicity test showed that CEE had the lowest IC50 on HeLa ($143.18{\pm}13.35 {\mu}g/mL$) and SiHa cells ($106.45{\pm}15.73{\mu}g/mL$). C-33A cells were inhibited by CWE ($IC50=130.95{\pm}3.83{\mu}g/mL$). Conclusions: There were several phenolic compounds in Teawdang extracts which may have cytotoxic effects on cervical cancer cell lines. Investigation of these bioactive compounds as new sources of anticancer agents is recommended.

A study on synthesis of polyurethane dispersion by $H_{12}MDI$ and how effect to mechanical properties by ammonium dihydrogen phosphate ($H_{12}MDI$를 이용한 수분산 폴리우레탄 수지의 합성 및 ammonium dihydrogen phosphate에 의한 물성변화에 관한 연구)

  • Lee, Joo-Youb;Nam, Sang-Sung
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.1
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    • pp.74-82
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    • 2014
  • For this research, prepared ammonium dihydrogen phosphate aqueous solution and polyurethane dispersion. Use these resin, this article has been analyzed about change of mechanical properties by increasing amount of ammonium dihydrogen phosphate aqueous solution in polyurethan resin on coated leather and dried film. According to measure data for solvent resistance, DPU(polyurethane dispersion) resin and DPU-AD1, D2, D3(samples of polyurethaneresin with ammonium dihydrogen phosphate aqueous solution) had good property. As known in the results, increase of ammonium dihydrogen phosphate constant did not influence to big change of polyurethane resin properties. As test of tensile strength, DPU had highest tensile characteristic($3.114kg_f/mm^2$) and DPU-AD3 had lowest tensile characteristic($2.510kg_f/mm^2$). As same as tensile characteristic, abrasion test determined DPU(50.5 mg.loss) had highest properties. In elongation case, DPU had best properties(602 %) in this experiment.

Quality Characteristics of Domestic Strong Wheat Flour (시판 강력분 우리밀의 품질 특성)

  • Kwak, Han Sub;Kim, Mi Jeong;Kim, Oui-Woung;Kim, Sang Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.5
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    • pp.616-621
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    • 2017
  • The objective of this study was to investigate the physicochemical properties of domestic strong wheat flour (DSWF). Three commercial DSWFs (D1, D2, and D3) were compared with imported strong wheat flour (ISWF). DSWFs had higher moisture content, crude protein content, lightness, and whiteness than ISWF. DSWFs showed lower solvent retention capacity and water absorption index than ISWF. DSWFs also showed significantly higher water solubility index than ISWF (P<0.05). Setback values by rapid visco analysis were significantly higher in D1 and D2 than in ISWF and D3, which means ISWF and D3 were better in retarding retrogradation. Differential scanning calorimetry results showed that ISWF required 6.2 J/g of energy for phase transition, whereas DSWFs needed 6.67~7.13 J/g. The farinograph results showed that ISWF had higher water absorption, longer dough stability time, and significantly higher softening of dough at 20 min than DSWF (P<0.05). Dough resistance and extensibility were higher in ISWF than in DSWFs.

Synthesis and Curing Behavior of UV-curable Polycarbonate-based Polyurethane Methacrylate : Effect of Polyol Molecular Weight, Contents of Photoinitiator and Monomers on the Flexibility and Properties (자외선 경화형 폴리카보네이트계 폴리우레탄 메타아크릴레이트의 합성과 경화거동 : 폴리올 분자량, 광개시제 및 모노머 함량이 유연성과 물성에 미치는 영향)

  • Park, Eun-Suk;Hwang, Hyeon-Deuk;Park, Cho-Hee;Lee, Yong-Hee;Moon, Je-Ik;Kim, Hyun-Joong
    • Journal of Adhesion and Interface
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    • v.12 no.2
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    • pp.47-55
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    • 2011
  • UV-curable coatings have been used in various industries due to their advantages such as high mechanical property, good solvent resistance, fast curing process and low volatile organic compounds. However, a lack of flexibility of UV-cured films is a weak point for the pre-coated system of roll-to-roll process. In this study, UV-curable polycarbonate-based methacrylates were synthesized with polycarbonate diol, isophorone diisocyanate and 2-hydroxyethylmethacrylate to improve flexibility of the UC-cured films. The effects of polyol molecular weight, content of photoinitiator and monomers on the UV-curing behavior, flexibility and properties were investigated. The UV-curing behavior was measured by a photo-DSC, the pendulum hardness, tensile strength, viscoelastic properties were also evaluated.

Fabrication of Stack-Structured Gas Sensor of LaCrxCo1-xO3/Li1.3Al0.3Ti1.7(PO4)3 and Its NOx Sensing Properties (LaCrxCo1-xO3/Li1.3Al0.3Ti1.7(PO4)3의 적층구조를 가지는 가스센서 제조와 그의 NOx 검지특성)

  • Lee, Young-Sung;Shimizu, Y.;Song, Jeong-Hwan
    • Korean Journal of Materials Research
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    • v.25 no.8
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    • pp.423-428
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    • 2015
  • Impedancemetric $NO_x$ (NO and $NO_2$) gas sensors were designed with a stacked-layer structure and fabricated using $LaCr_xCo_{1-x}O_3$ (x = 0, 0.2, 0.5, 0.8 and 1) as the receptor material and $Li_{1.3}Al_{0.3}Ti_{1.7}(PO_4)_3$ plates as the solid-electrolyte transducer material. The $LaCr_xCo_{1-x}O_3$ layers were prepared with a polymeric precursor method that used ethylene glycol as the solvent, acetyl acetone as the chelating agent, and polyvinylpyrrolidone as the polymer additive. The effects of the Co concentration on the structural, morphological, and $NO_x$ sensing properties of the $LaCr_xCo_{1-x}O_3$ powders were investigated with powder X-ray diffraction, field emission scanning electron microscopy, and its response to 20~250 ppm of $NO_x$ at $400^{\circ}C$ (for 1 kHz and 0.5 V), respectively. When the as-prepared precursors were calcined at $700^{\circ}C$, only a single phase was detected, which corresponded to a perovskite-type structure. The XRD results showed that as the Co concentration of the $LaCr_xCo_{1-x}O_3$powders increased, the crystal structure was transformed from an orthorhombic phase to a rhombohedral phase. Moreover, the $LaCr_xCo_{1-x}O_3$ powders with $0{\leq}x<0.8$ had a rhombohedral symmetry. The size of the particles in the $LaCr_xCo_{1-x}O_3$powders increased from 0.1 to $0.5{\mu}m$ as the Co concentration increased. The sensing performance of the stack-structured $LaCr_xCo_{1-x}O_3/Li_{1.3}Al_{0.3}Ti_{1.7}(PO_4)_3$ sensors was found to divide the impedance component between the resistance and capacitance. The response of these sensors to NO gas was more sensitive than that to $NO_2$ gas. Compared to other impedancemetric sensors, the $LaCr_{0.8}Co_{0.2}O_3/Li_{1.3}Al_{0.3}Ti_{1.7}(PO_4)_3$ sensor exhibited good reversibility and reliable sensingresponse properties for $NO_x$ gases.

A Study on Synthesis Acrylic Polymer Resin and Mechanical Properties Containing Monoammonium Phosphate (Monoammonium phosphate를 포함한 아크릴 수지의 합성 및 물성에 관한 연구)

  • Lee, Joo-Youb;Kim, Ki-Jun
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.3
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    • pp.500-508
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    • 2014
  • For this research, synthesis acrylic resin by ethyl acrylate monomer(EAM) and prepared samples which set by difference amount of monoammonium phosphate solution in waterborne acrylic resin. Use these resins, analyzed mechanical properties and thermal stability by films and leather surface coated. The test of DSC experiment sample WAC-APS3 was $410^{\circ}C$ Tm values which means the highest content of monoammonium phosphate had highest thermal stability in acrylic resin. According to measure data for solvent resistance, all samples showed good property. As known in the results, increase of ammonium phosphate constant did not influence to big change of resin properties. In abrasion test WAC-APS3 was good abrasion properties(68.729 mg.loss). Test of tensile strength, as increase as monoammonium phosphate resin analyzed low properties $1.505kgf/mm^2$ to $1.275kgf/mm^2$. In elongation case, same as strength test result 425 % to 384 % by increase to monoammonium phosphate amount in acrylic resin.

Automotive Pre-primed Coatings with Automotive Structural Adhesive for Non-weldable Binding Process (자동차 구조용 접착제를 이용한 자동차용 Pre-primed 도료의 비용접식 접합공정 적용)

  • Moon, Je-Ik;Lee, Yong-Hee;Kim, Hyun-Joong;Noh, Seung Man;Nam, Joon Hyun;Kim, Min-Su;Kim, Jun-Ki;Kim, Jong-Hoon
    • Journal of Adhesion and Interface
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    • v.12 no.3
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    • pp.99-104
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    • 2011
  • Currently, automotive pre-primed coatings has been developed to overcome environmental regulations and to reduce manufacturing cost in automotive industry. By these reasons, an automotive pre-primed system has been investigated to remove the wash and pre-treatment process using a roll coating application. It is required to develop non-weldable pre-primed system for automotive structural adhesives, because pre-primed sheet coated with organic compounds is hard to be assembled by welding process. Primer 1 (polyester type) and primer 2 (urethane type) were designed to satisfy flexibility and formability for non-weldable pre-primed system. According to the results of physical property test of the primers, adhesion test such as single-lap shear test and T-peel test, primer 1 (polyester type) had better physical properties such as pencil hardness, solvent resistance, flexibility and adhesion with automotive adhesive than that of primer 2 (polyurethane type). In addition, the possibility of the non-weldable pre-primed system was applicable to automotive assembly process in place of welding process.