• 제목/요약/키워드: Nano-bio technology

검색결과 533건 처리시간 0.026초

Electro-optic Characteristics of Polymer Dispersed Liquid Crystal Films

  • Yang, Kee-Jeong;Kim, Chang-Geun;Lee, Seung-Chul;Do, Yun-Seon;Kim, Bae-In;Choi, Byeong-Dae
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.902-903
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    • 2009
  • Polymer Dispersed Liquid Crystal (PDLC) films were prepared using the phase separation method with liquid crystal and a newly developed prepolymer. This study investigated the electro-optic characteristics of the PDLC film at various temperatures. It was found that as temperatures increased, the voltage varied, and that the ordinary refractive index of the liquid crystal and the polymer refractive index in the composite had similar dependence at various temperatures.

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세피아 멜라닌에 의한 양모 염색 (Wool Dyeing with Sepia Melanin)

  • 김수진;권혜륜;유정화;장진호
    • 한국염색가공학회지
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    • 제22권1호
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    • pp.14-20
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    • 2010
  • Squid ink was purified to melanin powder by repeated treatments with aqueous sodium hydroxide and acetic acid solutions. The exhaustion dyeing conditions of melanin to wool fabrics were investigated in relation with pH, melanin concentration, dyeing temperature and time. The melanin was dyeable to cotton and wool fabrics but higher dyeability of the wool was observed. A K/S of 7 was obtained on the optimally dyed wool fabrics with 5 % owf melanin under pH 4 at $100^{\circ}C$ for 60 minutes. Color fastness to both washing and rubbing was excellent and color fastness to light was also very good probably due to the polymeric nature of the extracted sepia melanin.

Optimization of adipogenic differentiation conditions for canine adipose-derived stem cells

  • Kim, Jong-Yeon;Park, Eun-Jung;Kim, Sung-Min;Lee, Hae-Jeung
    • Journal of Veterinary Science
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    • 제22권4호
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    • pp.53.1-53.13
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    • 2021
  • Background: Canine adipose-derived stem cells (cADSCs) exhibit various differentiation properties and are isolated from the canine subcutaneous fat. Although cADSCs are valuable as tools for research on adipogenic differentiation, studies focusing on adipogenic differentiation methods and the underlying mechanisms are still lacking. Objectives: In this study, we aimed to establish an optimal method for adipogenic differentiation conditions of cADSCs and evaluate the role of peroxisome proliferator-activated receptor gamma (PPARγ) and estrogen receptor (ER) signaling in the adipogenic differentiation. Methods: To induce adipogenic differentiation of cADSCs, 3 different adipogenic medium conditions, MDI, DRI, and MDRI, using 3-isobutyl-1-methylxanthine (M), dexamethasone (D), insulin (I), and rosiglitazone (R) were tested. Results: MDRI, addition of PPARγ agonist rosiglitazone to MDI, was the most significantly facilitated cADSC into adipocyte. GW9662, an antagonist of PPARγ, significantly reduced adipogenic differentiation induced by rosiglitazone. Adipogenic differentiation was also stimulated when 17β-estradiol was added to MDI and DRI, and this stimulation was inhibited by the ER antagonist ICI182,780. Conclusions: Taken together, our results suggest that PPARγ and ER signaling are related to the adipogenic differentiation of cADSCs. This study could provide basic information for future research on obesity or anti-obesity mechanisms in dogs.

옻 추출물을 이용한 면직물 염색에서의 농색화 및 항미생물성 가공 (Color Deepening and Antimicrobial Finish in the Dyeing of Cotton Fabrics using Rhus verniciflua Extract)

  • 장용준;최영환;이혜미;탁미소;류원석;장진호
    • 한국염색가공학회지
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    • 제23권1호
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    • pp.28-34
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    • 2011
  • Deep coloration of cotton fabrics with concentrated Rhus verniciflua extract was carried out using large amount of Glauber's salt and a mordant in order to improve dyeability and functional properties such as deodorizing and antimicrobial activity. With increasing in the salt addition upto 80% in the dyeing liquor containing 0.45% extract concentration, K/S value and exhaustion increased threefold from 1.2 to 3.5, indicating that the salt reduced the electrostatic repulsion between the dyes and the cotton fibers. Also the concentrated extract solution to 8% can increase the color build up upto a K/S of 11.1. In addition the combined pre- and post-mordanting methods with potassium alum enhanced the dyeability upto a K/S of 22.2. The ammonia deodorizing property increased with increased color yield of the dyed fabrics. Also the dyed and post-mordanted fabrics with 8% extract concentration showed antimicrobial activity against both Klebsiella pneumoniae and Staphylococcus aureus.

Multimodal Nonlinear Optical Microscopy for Simultaneous 3-D Label-Free and Immunofluorescence Imaging of Biological Samples

  • Park, Joo Hyun;Lee, Eun-Soo;Lee, Jae Yong;Lee, Eun Seong;Lee, Tae Geol;Kim, Se-Hwa;Lee, Sang-Won
    • Journal of the Optical Society of Korea
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    • 제18권5호
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    • pp.551-557
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    • 2014
  • In this study, we demonstrated multimodal nonlinear optical (NLO) microscopy integrated simultaneously with two-photon excitation fluorescence (TPEF), second-harmonic generation (SHG), and coherent anti-Stokes Raman scattering (CARS) in order to obtain targeted cellular and label-free images in an immunofluorescence assay of the atherosclerotic aorta from apolipoprotein E-deficient mice. The multimodal NLO microscope used two laser systems: picosecond (ps) and femtosecond (fs) pulsed lasers. A pair of ps-pulsed lights served for CARS (817 nm and 1064 nm) and SHG (817 nm) images; light from the fs-pulsed laser with the center wavelength of 720 nm was incident into the sample to obtain autofluorescence and targeted molecular TPEF images for high efficiency of fluorescence intensity without cross-talk. For multicolor-targeted TPEF imaging, we stained smooth-muscle cells and macrophages with fluorescent dyes (Alexa Fluor 350 and Alexa Fluor 594) for an immunofluorescence assay. Each depth-sectioned image consisted of $512{\times}512$ pixels with a field of view of $250{\times}250{\mu}m^2$, a lateral resolution of $0.4{\mu}m$, and an axial resolution of $1.3{\mu}m$. We obtained composite multicolor images with conventional label-free NLO images and targeted TPEF images in atherosclerotic-plaque samples. Multicolor 3-D imaging of atherosclerotic-plaque structural and functional composition will be helpful for understanding the pathogenesis of cardiovascular disease.

Glucose Oxidation on Gold-modified Copper Electrode

  • Lim, Ji-Eun;Ahn, Sang Hyun;Pyo, Sung Gyu;Son, Hyungbin;Jang, Jong Hyun;Kim, Soo-Kil
    • Bulletin of the Korean Chemical Society
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    • 제34권9호
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    • pp.2685-2690
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    • 2013
  • The activities of Au-modified Cu electrodes toward glucose oxidation are evaluated according to their fabrication conditions and physico-chemical properties. The Au-modified Cu electrodes are fabricated by the galvanic displacement of Au on a Cu substrate and the characteristics of the Au particles are controlled by adjusting the displacement time. From the glucose oxidation tests, it is found that the Au modified Cu has superior activity to the pure Au or Cu film, which is evidenced by the negative shift in the oxidation potential and enhanced current density during the electrochemical oxidation. Though the activity of the Au nanoparticles is a contributing factor, the enhanced activity of the Au-modified Cu electrode is due to the increased oxidation number of Cu through the electron transfer from Cu to more electronegative Au. The depletion of electron in Cu facilitates the oxidation of glucose. The stability of the Au-modified Cu electrode was also studied by chronoamperometry.

셀룰로오스 아세테이트 안경테 판재에 관한 연구 (Studies on the Cellulose Acetate Glasses Frame Sheet)

  • 이해성;이성준;정상원;김현철;김은주;고영준;이세근
    • 한국안광학회지
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    • 제16권1호
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    • pp.13-19
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    • 2011
  • 목적: 본 연구는 국외에서 판매중인 셀룰로오스 아세테이트 안경테용 판재(수입 CA판재, overseas company's cellulose acetate glasses frame sheet)의 특성을 평가하고 안경테용 CA 판재로서 적합한 공업용 셀룰로오스 아세테이트 레진(공업용 CA레진, industrial cellulose acetate resin)을 선정하여 그 소재의 최적 용융 압출 조건을 도출하는 데 목적이 있다. 방법: 수입 CA판재의 특성을 고찰하기 위해 $^1H$-NMR, GPC, TGA 분석을 실시하고, 공업용 CA레진의 최적 배합 조건 및 용융 압출 조건을 도출한다. 또한 hot press에 의해 제조 된 3개국의 수입 CA판재와 공업용 CA레진 성형체의 물성을 비교 평가를 실시하였다. 결과: 수입 CA판재의 특성 분석 결과, virgin CA를 가소화시키기 위해 사용된 가소제는 diethyl phthalate이며 가소제의 함량은 30 wt% 내외임을 확인하였다. 용융 압출 시험 결과, 압출온도는 190~200${^{\circ}C}$에서 공업용 CA레진의 충분한 용융거동 및 압출성을 보였으며 성형체 또한 안경테용 물성을 만족하는 수준인 2.3 kgf/$mm^2$임을 확인하였다. 결론: 30 wt%의 가소제 함량을 가진 공업용 CA레진의 경우, 중국의 CA판재를 대체하여 안경테용 셀룰로오스 아세테이트 판재 제조에 적합한 소재로 판단된다.