• 제목/요약/키워드: biological stability

검색결과 838건 처리시간 0.027초

Synthesis and optimization of immunomodulating hydrogel for biomedical application

  • Muthuramalingam, Karthika;Park, Sanggyu;Cho, Moonjae
    • Journal of Applied Biological Chemistry
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    • 제61권4호
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    • pp.351-355
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    • 2018
  • Treatment towards wound healing, a complex and dynamic process, has been given a great deal of efforts in the last few decades. Focus has been imposed on developing wound dressings that meet the requirements for proper wound healing. In this study, hydrogel made from blends of poly (vinyl alcohol) and ${\beta}$-1,6-branched-${\beta}$-1,3-glucan (beta-glucan) were synthesized by modified solvent casting method for wound dressing application. Optimization of hydrogel composition and analysis of wound dressing parameters such as stability and fluid uptake capacity (in the presence of water, saline and different pH solutions) has been studied. The result indicated that the PVA/beta-glucan hydrogel hold its structural integrity even at alkaline pH (pH~9) and upholds fluids four times of its original weight. Thus, the developed hydrogel is expected to be a promising candidate as wound dressing.

마이크로LED를 응용한 차세대 생체 치료 소자 개발 (Next-Generation Biomedical Devices via MicroLEDs)

  • 이한얼
    • 한국전기전자재료학회논문지
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    • 제34권4호
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    • pp.221-228
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    • 2021
  • With the advent of the IoT (internet of things) era, there has been discussion on how to efficiently use various information from daily life. In academic and industrial society, various smart devices such as smart watches, smart phones, and smart glasses have been developed and commercialized for narrowing the physical/psychological distance with user information. According to recent developments of smart devices, the contemporary people have desired to check their body information and treat disease by themselves. According to the needs of the time, biological researches by phototherapy/monitoring have been actively conducted. Among various light sources, microLEDs have been spotlighted due to their superior optoelectric properties and stability. In this paper, we would like to review the state-of-the research results on the next-generation biological therapy devices via microLEDs.

POLYVINYLPYRROLIDONE METAL COMPLEXES. FORMATION STABILITY AND THEIR BIOLOGICAL ACTIVITY

  • Lee, V. A.;S. Sh. Rashidova
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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    • pp.463-465
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    • 1998
  • The peculiarities of the polyvinylpyrrolydone (PVP) interaction with transition metal ions of the first row in solution were studied. It was shown that PVP macromolecules due to their swelling conformation in organic solvents form the stable metal complexes. Metal ions were bond with oxygen and nitrogen atoms of PVP lactam rings. In water solution every metal ion interacts with one or two oxygen atoms out of 10-12 monomer units of the polymer. The additional contraction of PVP macromolecule coils in water have been found out by dissolving of the polymer metal complexes (PMC) synthesized in organic media. Toxicity, blood forming and immune stimulating activity and pharmaco-kinetic too of obtained polymers and their metal completes have been investigated. The factors and effects that responsible fur changing of PMC physical-chemical and biological properties have been estimated.

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Effect of alpha-tocopheryl acetate, retinyl palmitate, and phytantriol on hair protection

  • Ki Young Ahn;Hong Jong Song;Dong Chung Kim
    • Journal of Applied Biological Chemistry
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    • 제65권4호
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    • pp.307-312
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    • 2022
  • A hair essence containing α-tocopheryl acetate, retinyl palmitate, and phytantriol (TRP-hair essence) was prepared. TRP-hair essence was excellent in thermal stability to the extent that it did not harden at all even at 210 ℃. TRP-hair essence potently protected the hair from heat stress, significantly reducing the protein leakage in heat-treated hair (p <0.001). Treatment of TRP-hair essence to dyed human hair significantly protected hair against heat stress (p <0.05) as well as improved hair cuticle and color persistence (p <0.05). In addition, as a result of directly treating human hair with TRP-hair essence, the cuticle and tensile strength of human hair were significantly improved (p <0.05). These results suggest that TRP-hair essence can be effective for hair protection and hair quality improvement.

사이클로덱스트린과 전분을 이용한 coenzyme Q10 복합체의 특성 연구 (Structural and Solubility Characteristics of Coenzyme Q10 Complexes Including Cyclodextrin and Starch)

  • 이준경;이현주;임재각
    • 한국식품과학회지
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    • 제46권2호
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    • pp.180-188
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    • 2014
  • 본 실험에서는 coenzyme $Q_{10}$을 cyclodextrin, starch를 이용하여 각각 복합체를 형성하고 형성된 복합체의 용해도 및 구조적 특성을 확인하였다. Starch 복합체는 용해 온도가 증가할수록 복합체 및 복합체내의 coenzyme $Q_{10}$의 용해도가 유의적으로 증가하는데 비해 cyclodextrin 복합체는 $37^{\circ}C$에서 coenzyme $Q_{10}$의 최대 용해도를 보였으며 이후 $50^{\circ}C$에서는 강하게 aggreagation이 일어났고, $80^{\circ}C$에서는 약해진 결합에 의해 복합체가 깨짐으로써 coenzyme $Q_{10}$이 물 위에 뜨는 형상을 나타내었다. 두 복합체의 구조적 차이를 FT-IR, XRD, DSC를 통하여 확인한 결과 cyclodextrin 복합체는 coenzyme $Q_{10}$의 isoprenoid chain에 주로 포접이 되어 있는데 반해 starch 복합체는 coenzyme $Q_{10}$의 isoprenoid chain 뿐만 아니라 benzoquinone ring에도 포접되어 있는 것을 확인하였고, 또한 starch 복합체가 cyclodextrin 복합체에 비해 coenzyme $Q_{10}$ 무정형영역이 더 크게 증가되어 있는 것을 확인하였다. In vitro simulated digestion model을 통하여 각 소화기관 별 복합체의 방출 패턴을 확인 한 결과 두 복합체 모두 구강, 위장의 효소 및 조건에 비해 소장의 효소와 조건에서 유의적으로 크게 coenzyme $Q_{10}$의 방출이 확인되었다. 따라서 coenzyme $Q_{10}$은 cyclodextrin, starch와 포접되어 복합체를 형성함으로서 생체이용율의 향상을 기대할 수 있다.

다양한 pH조건에서 가열처리에 의한 시나핀산의 화학 안정성 및 생리활성 변화 (Changes in chemical stability and biological activities of sinapinic acid by heat treatment under different pH conditions)

  • 허윤선;홍정일
    • 한국식품과학회지
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    • 제52권6호
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    • pp.616-621
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    • 2020
  • 본 연구에서는 다양한 pH 환경에서 식품의 가공 및 조리과정 중에 빈번히 적용되는 가열처리 과정을 적용하여 시나핀산의 화학 안정성, 산화방지활성 및 세포독성 등의 생리활성 변화를 조사하였다. 95℃에서 각 시간별로 가열처리한 시나핀산은 가열시간이 증가할수록 더 많이 분해되었으며 pH가 상승할수록 더 신속하게 분해되었다. 가열처리에 의해 시나핀산의 ABTS 라디칼소거능 및 FRAP 환원능이 모두 감소하였으며, 특히 pH 7과 8에서는 가열처리 시간에 유의적으로 현저하게 감소하였다. HCT116 인간 대장암세포에 대한 시나핀산의 세포독성 평가에서 가열처리 전의 시나핀산은 500 μM 농도까지 세포독성을 나타내지 않은 반면, pH 8에서 가열처리한 후에는 해당 농도에서 유의적인 세포독성을 발현하였으며 세포 내 glutathione 수치 또한 감소되었다. 본 연구결과는 시나핀산의 화학 안정성 및 생리활성이 가열처리와 pH 환경에 의해 많은 영향을 받으며, 시나핀산이 함유된 식품을 알칼리 조건에서 가열처리 시 성분의 손실 및 활성의 변화를 초래할 수 있음을 시사한다.

효소에 의한 제탁조작과 맥주의 발포성 제 III보 Papain 농도와 저장조건의 영향 (Enzymatic Chillproofing and Beer Foam Stability Part III. Effects of Papain Concentration and Storage Condition)

  • Pack, M.Y.
    • 한국미생물·생명공학회지
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    • 제4권4호
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    • pp.159-165
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    • 1976
  • 신선한 풋맥주를 발포성의 손실을 피하기 위해 적은 양의 Papain으로 제탁시켰다. 맥주를 병에 넣은 다음 멸균은 시키지 않고 온도와 시간을 달리하여 저장 시킨다음 발포성을 조사해 보았다. 15 ppm의 papain으로 $0^{\circ}C$에서 22일동안 제탁시키고 멸균을 하지 않았을 경우에 맥주의 발포성이 현저히 좋아졌다. 이 사실은 멸균을 하지 않는 생맥주제조에 이용될 것으로 본다.

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Viologen 박막을 이용한 과산화수소의 전기화학적 검출 특성 (Electrochemical Detection of Hydrogen Peroxide based on Viologen Monolayers)

  • 최원석;이동윤;박상현;박재철;권영수
    • 전기학회논문지
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    • 제57권11호
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    • pp.2006-2010
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    • 2008
  • In this paper, we fabricated a biosensor for detecting hydrogen peroxide and investigated the sensing property. We prepared a viologen and hemoglobin modified gold electrode using self-assembly and layer by layer method. The electrochemical property of the viologen derivative was characterized in 0.1 M $NaClO_4$ electrolyte solution by cyclic voltammetry. The modified electrode showed reversible electrochemical properties and high stability. From the results, the viologen can act as a charge transfer mediator for access to the electrode surface. The catalytic characteristics of the designed sensor proved that hemoglobin has been kept in its natural structure and can retain its biological activity. The designed biosensor showed a fast amperometric response, excellent linearity and low detection limit. In addition, it had high sensitivity, good reproducibility and stability.

이성분 혼합액의 방향성 응고에서 자연 대류 (Natural Convection During Directional Solidification of a Binary Mixture)

  • 황인국;최창균
    • Korean Chemical Engineering Research
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    • 제47권2호
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    • pp.174-178
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    • 2009
  • 이성분 혼합물의 응고중에 수지상 결정으로 이루어진 mush 층이 형성될 수 있다. 본 연구진이 개발한 전파이론으로 mush 층에서 성분적 대류의 발생을 해석하였다. Emms와 Fowler의 모델로부터 유도한 자기유사 안정성 방정식을 사용하여 대류 발생에 대한 임계 Rayleigh 수를 수치방법으로 계산하였다. 과열량이 아주 크거나 mush 층의 성장률이 아주 작은 극한의 경우에 본 연구 결과는 준정적 안정성 해석 결과와 같아진다.

CAD/CAM Zirconia All Ceramic Restoration and Red-White Esthetics

  • 조종만
    • 대한심미치과학회지
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    • 제13권1호
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    • pp.31-39
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    • 2004
  • For the prosthodontic results which are compatible with esthetics to be fulfilled, the first prerequisite would be periodontal intervention and stability, the second one may be functional competency and the ultimate goal should be ascribed to esthetic considerations. Other words, esthetic dentistry is a whole entity which encompasses the biological stability of the periodontium, physical accuracy of the prosthodontic structure and finally, the beauty which can be found in natural dentition. It also implies the harmonized lip line which reveals the well-balanced tooth morphology and health gum profiles (Red-White Esthetics). Largely, there lie some differences in the input system of the 3-dimentional data from the prepared abutments between respective computer-assisted systems available now. But the manufacturing systems (CAM) are very similar between them, to say, comprise numeric control systems with whole 3-dimensional milling units according to the restorations to be made. Now the author is going to present CAD/CAM Zirconia All Ceramic Restoration on the topics for the Red-White Esthetics, periodontal control and maintenance, treatment for the discolored teeth, post & core build-up works for the devitalized teeth, characteristics of the Zirconium oxide All Ceramics, fabrication procedures, clinical considerations and its application to diverse clinical situations.

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