• 제목/요약/키워드: Solid support

검색결과 356건 처리시간 0.021초

An Antioxidant Capacity Assay Using a Polyvinyl Alcohol-Based DPPH Pellet

  • Ahn, Yeong-Hee;Yoo, Jong-Shin;Kim, Sung-Ho
    • Bulletin of the Korean Chemical Society
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    • 제31권9호
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    • pp.2557-2560
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    • 2010
  • To assay for antioxidant capacity of natural products considered important in producing human health benefits, a practical and economical method using pellet techniques was developed. A standard visualizing reagent, 1,1diphenyl-2-picryl-hydrazyl (DPPH), was mixed with a water-miscible polyvinyl alcohol (PVA), serving as a solid phase support for the DPPH reagent. A DPPH pellet was prepared by dropping a small volume of the DPPH solution onto PET film, and drying in an oven. The PVA-based DPPH pellet was dissolved into water, in which the water-miscible PVA plays as a non-ionic surfactant to help the DPPH reagent to be dissolved into the solvent. Using the DPPH assay, the antioxidant capacity of water-soluble extracts of black soybean, barley, green tea, and green gram was examined. Among the natural products tested, green tea showed the highest antioxidant capacity. This PVA-based DPPH antioxidant assay can be further applied in the natural food, raw plant material, and health product inspection field.

변단면 Beck 기둥의 동적안정 해석 (Dynamic Stability Analysis of Tapered Beck Columns)

  • 이병구;이태은;강희종;김권식
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2006년도 정기 학술대회 논문집
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    • pp.949-954
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    • 2006
  • The purpose of this paper is to investigate the stability of tapered columns with clamped one end and carrying a tip mass of rotatory inertia with translational elastic support at the other end. The linearly tapered columns with the solid rectangular cross-section is adopted as the column taper. The differential equation governing free vibrations of such Beck columns is derived using the Bernoulli-Euler beam theory. Both the divergence and flutter critical loads are calculated from the load-frequency curves which are obtained by solving the differential equation. The critical loads are presented as functions of various non-dimensional system parameters: the taper type, the subtangential parameter, mass ratio and spring stiffness.

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화장품산업의 현황 및 발전방안 (Cosmetic Industry and Its Development Strategy)

  • 김영찬;황순욱;김대중
    • 대한화장품학회지
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    • 제30권1호
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    • pp.1-6
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    • 2004
  • 국내상황을 볼 때 수입화장품의 점유율 상승으로 인해 국내시장 잠식이 확대되고 있으며, 기능성 화장품의 성장 가능성에 대한 제도적 뒷받침이 미비하고, 천연소재를 사용한 고기능성 화장품 시장규모가 확대 추세에 있다. 외부적 환경으로는 무역역조가 심화되는 추세이며 해외 수출기반이 취약한 상태이어서 제외국과 비교하여 기능성 화장품 개발 촉진을 위한 제도가 미비한 상태이다. 따라서 화장품 산업의 진흥을 위하여 기본방향으로 고품질 신제품 개발을 촉진하고, 세계 시장으로의 수출을 확대하며 화장품법령의 합리적 개선을 추구하여야 한다.

영유아 급성 설사의 영양 공급: 탈수 치료 후 연령별 식이요법을 중심으로 (Nutritional Support for Acute Diarrhea in Children: Focused on Age-appropriate Diet Therapy after Rehydration)

  • 추미애;최병호
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제12권sup1호
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    • pp.53-61
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    • 2009
  • The mainstay in the management of mild to moderately dehydrated children is fast rehydration by using hypotonic ORS (oral rehydration solution) and complete resumption of normal diet, including lactose-containing formula after 4 hours rehydration. Since the majority of young children with uncomplicated acute diarrhea will tolerate large amounts of undiluted non-human milk, withholding food and milk from children during diarrhea is not recommended anymore, regarding time to resolution and diarrhea control. In addition, routine dilution of milk and routine use of lactose-free formula are not necessary after fast ORS therapy. Breastfed infants and children fed with solid foods may safely continue receiving their usual diets during diarrhea instead of gradual reintroduction of feeding. However, young infants or children with severe diarrhea or malnutrition should be carefully treated under supervision if fed with lactose containing, non-human milk exclusively.

Structural Analysis for the Single Crystal of 2-(4-(9H-carbazol-9-yl)benzylidene) based Dye Compound

  • Hwang, Jiyong;Son, Young-A
    • 한국염색가공학회지
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    • 제26권2호
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    • pp.143-149
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    • 2014
  • The designed dye material, namely 2-(4-(9H-carbazol-9-yl)benzylidene) compound, was synthesized. After the reaction, the solid was filtered and purified by recrystalization with acetone/water. To confirm and analyze its synthesis and structural formation, the single crystal was prepared and its measurement was carried out. A yellow needle crystal of $C_{22}H_{13}N_3$ were made on a Rigaku R-AXIS RAPID diffractometer using graphite monochromated CuK${\alpha}$ radiation. All details were suggested and introduced to support and communicate this study.

Methyl- $\beta$ -D-Fructofuranoside 합성을 위한 고정화 전화당 효소의 미소환경 최적화 (Microenvironmental Optimizaton of Immobilized Invertase for Methyl- $\beta$ -D-Fructofuranoside Synthesis)

  • 허주형;안형환
    • 대한안전경영과학회지
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    • 제1권1호
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    • pp.259-272
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    • 1999
  • In order to enhance the selectivity, productivity and yield of methyl fructoside, which was synthesized by enzymatic glycosylation of sucrose and methanol solution, controlling of surface property of solid support using different immobilization procedures optimized microenvironment of immobilized invertase. Silanization and polyethylene imine coating methods were adopted to give a hydrophobic and hydrophilic environment of immobilized invertase. As a result, polyethyleneimine coating method gave higher loading of enzyme, effective activity, and relative activity than silanization method, because it brought on increasing the functional density of amino group and enhancing the conservation of activity by regulating of hydrophilicity. And then, hydrophilic environment was possible to restraint the assessing of methyl fructoside molecule, which was more hydrophobic than sucrose, fructose, and glucose molecule in the reaction mixture, into .the active site of immobilizedinvertase. Consequently, hydrophilic microenvironment of immobilized invertase by polyethyleneimine coating obtained higher yield and productivity with increasing conversion than silanized and native invertase. Thus, this procedure optimized the microenvironment of immobilized invertase suitable for the enzymatic synthesis of methyl fructoside.

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Stencil Buffer를 이용한 형상의 복셀화 (Hardware accelerated Voxelization using a Stencil Buffer)

  • 장동고;김광수
    • 한국경영과학회:학술대회논문집
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    • 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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    • pp.266-271
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    • 2002
  • We propose a hardware accelerated voxelization method for various 3D object model such as surface models, solid models, and volumetric CSG models. The algorithm utilizes the stencil buffer that is one of modern Open히 graphics hardware features. The stencil buffer is originally used to restrict drawing to certain portions of the screen. The volumetric representations of given 3D objects are constructed slice-by-slice. For each slice, the algorithm restricts the drawing areas constructed inner region of 3D objects using the stencil buffer, and generates slices of the volumetric representation for target objects. As a result, we can provide volume graphics support for various engineering applications such as multi-axis machining simulation, collision detection and finite element analysis.

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Phase Equilibria and Reaction Paths in the System Si3N4-SiC-TiCxN1-x-C-N

  • H.J.Seifert
    • 한국분말재료학회지
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    • 제6권1호
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    • pp.18-35
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    • 1999
  • Phase equilibria in the system Si3N4-TiC-TiCxN1-x-C-N were determined by thermodynamic calculations (CALPHAD-method). The reaction peaction paths for Si3N4-TiC and SiC-TiC composites in the Ti-Si-C-n system were simulated at I bar N2-pressure and varying terpreatures. At a temperature of 1923 K two tie-triangles (TiC0.34N0.66+SiC+C and TiC0.13N0.87+SiC+Si3N4) and two 2-phase fieds (TiCxN1-x+SiC; 0.13

Electroblotting을 이용한 단일클론항체의 $NH_2$-말단 아미노산 배열분석 ($NH_2-terminal$ Amino acid Sequence Analysis of Monoclonal Antibody by Electroblotting Method)

  • 남경수;장현욱;정규찬
    • 약학회지
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    • 제34권1호
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    • pp.11-14
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    • 1990
  • $NH_2-terminal$ amino acid sequence analysis of monoclonal antibody is very important to identify gene family and diversities of antigen-antibody recognition. When we used the PVDF (Polyvinylidene difluoride) membrane blotting method, we could easily analyze $NH_2-terminal$ sequence of monoclonal-antibody which specifically binds to phosphatidylinositol 4,5-biphosphate. PVDF membrane is an ideal solid-phase support for sequence analysis, especially when used with electroblotting method. This method is superior to continual method and will be applied to the sequence analysis of picomole quantities of proteins by gel electrophoresis.

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Eco-friendly Solventless Synthesis of 5-Indolylpyrimido[4,5-d]pyrimidinones and Their Antimicrobial Activity

  • Gupta, Ragini;Jain, Anshu;Joshi, Rahul;Jain, Meenakshi
    • Bulletin of the Korean Chemical Society
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    • 제32권3호
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    • pp.899-904
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    • 2011
  • A series of 5-indolylpyrimido[4,5-d]pyrimidinones (4a-h) were obtained by multi-component reaction of 3-formylindole (1), thiobarbituric acid/barbituric acid (2) and thiourea/urea (3) under microwave irradiation in dry media. Secondly, grinding together neat reactants also gave the titled compounds in good yields. All the synthesized compounds have been characterized on the basis of elemental analyses and spectral data (IR, $^1H$ NMR and Mass). Representative compounds were also evaluated for their antimicrobial activity against Rhizopus stolonifer, Fusarium oxysporum, Escherichia coli, and Pseudomonas aeruginosa at different concentrations. Some of the compounds showed promising activity.