• 제목/요약/키워드: sonication

검색결과 382건 처리시간 0.022초

리포솜을 이용한 플라스미드 DNA의 봉입 (Entrapment of Plasmid DNA in Liposomes)

  • 송미향;이만형;용철순;오두만
    • Journal of Pharmaceutical Investigation
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    • 제26권4호
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    • pp.291-297
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    • 1996
  • Liposomes of $pSV-{\beta}-Galactosidase$ vector plasmid DNA with various lipid composition were prepared by the thin-film method. Size distribution, shape and the efficiency of plasmid DNA encapsulation were investigated. Effect of sonication time on the plasmid DNA entrapment in liposomes and stability at $4^{\circ}C$ were also examined. Sizes of neutral liposomes were about 100-200 nm and above $1\;{mu}m$, and those of cationic liposomes were about 400-600 nm and above $1\;{mu}m$. Shapes of liposomes entrapped plasmid DNA were spherical. Proper sonication time for better entrapment was below 15 minutes and stability at $4^{\circ}C$ was decreased rapidly after 1 day. Plasmid DNA entrapments of complex liposomes of various lipids were higher than those of liposomes made from one sort of lipid. Plasmid DNA entrapments of cationic liposomes were higher than those of neutral liposomes.

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고강도 초음파를 이용한 Octamethylcyclotetrasiloxane의 에멀전 중합 (Emulsion Polymerization of Octamethylcyclotetrasiloxane under Ultrasonic Irradiation)

  • 김지혜;김유빈;김형수
    • 공업화학
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    • 제20권3호
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    • pp.322-328
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    • 2009
  • Octamethylcyclotetrasiloxane (OMCTS)을 에멀젼 상태에서 초음파를 조사하여 polydimethylsiloxane (PDMS)을 중합하였다. 중합에 활용된 초음파 반응기는 주파수가 20 KHz의 horn 유형과 40 KHz의 bath 유형이었으며, horn과 bath를 혼용한 경우의 중합 공정의 특성도 평가해 보았다. 고려된 주요 변수들은 반응 온도와 초음파 조사 시간 이었으며, 중합물에 대하여 각 시료의 고유 점도와 전환율 측정을 통하여 각 중합공정의 효율성과 특성을 조사하고, 최적의 공정 조건을 도출해 보고자 하였다. Horn 유형의 반응기에서는 수 분 이내에 80% 이상의 전환율이 달성되고 높은 점도의 PDMS를 얻을 수 있었으나, 조사 시간에 따라 전환율과 점도는 최대값을 보인 이후에 감소하는 경향을 나타내었다. 초음파의 강도가 상대적으로 약하게 유지되는 bath 유형의 반응기에서는 1 h 이상의 조사가 필요하였으며, horn 유형과 달리 전환율과 점도가 조사 시간에 따라 지속적으로 증가하는 경향이 지배적이었다. Horn유형과 bath유형을 조합한 혼합형 반응기에서는 다른 반응기와는 매우 다른 결과들이 나타났으며, 각 반응기의 특성은 전산 모사를 이용한 반응기 내의 음파 해석을 바탕으로 설명되었다.

돈육 부산물의 전처리 조건에 따른 품질특성 연구 (Study on the Quality Characteristics of Pork By-product on the Different Pretreatment Process)

  • 김태경;구수경;이혜진;이철원;김영붕;전기홍;최윤상
    • 한국식품조리과학회지
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    • 제32권6호
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    • pp.716-723
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    • 2016
  • Purpose: This study was conducted to improve the quality characteristics of pork intestine through different pretreatment processes. Methods: We washed pork intestine by both physical (tap water, UV, and sonication) and chemical methods (alcohol, acetic acid, flour and NaCl) as pretreatment process. The physicochemical (pH, color, volatile basic nitrogen (VBN), and 2-thiobarbituric acid reactive substances (TBARS)) and microbial properties of pre-treated pork small intestine were evaluated. Results: The nature of the pretreatment method influenced the pH value of pork small intestine. The acetic acid treatment resulted in the lowest pH value. In physical method, the color value and the number of microorganism were significantly affected by sonication as compared to other treatments. TBARS value of pork small intestine after all the treatments was lower than the control. However, VBN exhibited no significant differences in its value irrespective of the nature of treatment. Appearance and control exhibited lowest value in response to sonication treatment. However, off-flavor and overall acceptability were higher in sonication treatment than other treatments. In chemical method involving NaCl and flour treatments, lightness and redness were lower than other treatments. Lowest VBN and TBARS values were noted in alcohol and acetic acid treatmentsand no growth of E. coli and coliform bacteria was observed. The other treatments resulted in lower values of VBN, TBARS, and microbial counts than the control. Appearance and color value after alcohol, acetic acid, and flour treatment were lower than the control and NaCl treatment. Off-flavor and overall acceptability of by-product after alcohol, flour, and NaCl treatments were higher than the control and acetic acid treatment. Conclusion: Overall, we present NaCl treatment and sonication treatment in the form of a combination pretreatment method as the optimal condition for processing pork intestine.

토양세척에 있어서 탄성파의 효과에 관한 연구 (Investigation on the Effect of Stress Waves on Soil Flushing)

  • 김영욱;김지형;이인모
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2000년도 창립총회 및 춘계학술발표회
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    • pp.37-40
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    • 2000
  • Acoustically enhanced soil flushing method is a newly developed in-situ remediation technique. However, there has not been an analytical method that can be used to evaluate the effectiveness of ultrasonic wave under different conditions. This study was undertaken to investigate the degree of enhancement in contaminant removal due to ultrasonic energy on the soil flushing method. The test conditions included different levels of ultrasonic power and hydraulic gradient. The test soils were Ottawa sand, a fine aggregate, and a natural soil, and the surrogate contaminant was a Crisco Vegetable Oil. The test results showed that sonication could increase contaminant removal significantly. Increasing sonication power increased pollutant removal. The faster the flow is, the smaller the degree of enhancement will be. The pollutants in dense soils are more difficult to be removed than in loose soils.

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Expression of Modified Green Fluorescent Protein in Suspension Culture of Taxus cuspidata

  • Kim, Chang-Heon;Kim, Kyung-Il;Chung, In-Sik
    • Journal of Microbiology and Biotechnology
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    • 제10권1호
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    • pp.91-94
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    • 2000
  • The suspension cells of Taxus cuspidata were transformed with Agrobacterium tumefaciens harboring binary vector pCAMBIE1302 encoding mgfp. Transient transfection efficiency was compared by using the fluoremetric measurement. The transient transfection efficiency was improved by transformation with DMSO and/or sonication treatment. Optimum conditions for DMSO and sonication treatment were 3% and 30sec, respectively. selection and maintenance of transformed cells were continued for 3 months. An insertion of the mgfp gene in transformed cells was detected by PCR and an expression of GFP confirmed by the western blot analysis.

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Disrupting Escherichia coli: A Comparison of Methods

  • Benov, Ludmil;Al-Ibraheem, Jameela
    • BMB Reports
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    • 제35권4호
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    • pp.428-431
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    • 2002
  • The often-encountered problem of disrupting bacteria for the purpose of extracting soluble protein has generated various methods. Many require specialized equipment. Very often, especially during preliminary studies, investigators need a simple, fast, and inexpensive method for cell disruption that preserves biological activity. This paper compares some simple and inexpensive methods for cell disruption, such as bead-vortexing, freesing-thawing, French pressing, and sonication. It also provides some tips to increase protein yield and preserve biological activity. If performed under optimal conditions, bead-vortexing gives protein yields that are comparable to French pressing and sonication. It also preserves the activities of labile enzymes and releases periplasmic enzymes. Vortexing with glass beads appears to be the simplest method for cell disruption.

Liposome 봉입과정에서의 Plasmid DNA의 안정성 (Stability of Plasmid DNA during Liposome Encapsulation)

  • Ahn, J.S.;Pack, M.Y.
    • 한국미생물·생명공학회지
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    • 제13권3호
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    • pp.199-201
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    • 1985
  • 플라스미드 YEp13과 pMA56을 두가지 다른 방법으로 liposome속에 봉입시켰다. 이 두가지 방법에 따르면 플라스미드 DNA는 6$0^{\circ}C$에 1.5시간 동안 노출되거나, 4$^{\circ}C$에서 2-5분 동안 sonication 처리를 받아야 한다. 일단 봉입된 플라스미드를 다시 뽑아낸 다음, 그들에 대한 물리적인 구조와 유전적 전환능력을 조사했다. 그 결과 이 두 플라스미드 DNA는 liposome 봉입과정을 통해 아무런 손상을 입지 않았음이 밝혀졌다.

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Liposomes의 음성염색에 의한 전자현미경적 관찰 (Electron Microscopic Observation of Liposomes with Negative Stain)

  • 유용운;홍성운;김태환
    • Applied Microscopy
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    • 제19권2호
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    • pp.1-16
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    • 1989
  • To investigate the research of the tumor seeker using liposomes with negatively stained. The fine structure and size in liposomes composed of PC, DSPC, DAPC and SM phospholipid were observed. And the yield of vesicle affected with sonication by mechanical force were determined. The results were as follows. 1. The stain of 2% UA are obtained a good resolution from electron microscopic observation to compare the negatively liposomes with PTA, AM and UA solution. 2. The fine structure of liposomes except DAPC, PC and CH alone samples could be observed from EM experiment of liposomes composed of PC, DSPC, DAPC and SM phospholipid. 3. The results of experiment from 10, 20, 40 and 60 times sonication with 30sec, prepared 0.1mM NTA-SM-liposomes were obtained unilamella vesicles from groups of multilamella vesicles of phospholipid. 4. About 50nm diameter liposomes obtained through membration filtration step to prepare homogenized liposomes.

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솔잎의 피노실빈 고함유 추출물 생산을 위한 초음파 추출 공정 개발 (Development of Ultrasonication-assisted Extraction Process for Manufacturing Extracts with High Content of Pinosylvin from Pine Leaves)

  • 조용진;이상국;안용현;피재호
    • Journal of Biosystems Engineering
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    • 제28권4호
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    • pp.325-334
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    • 2003
  • Pinosylvin, a stilbenoid phytoalexin, is a health ingredient to be extracted from pine leaves. In this study, ultrasonication-assisted extraction process for manufacturing extracts with high content of pinosylvin from pine leaves was investigated. As process and system variables, ultrasonic power, sonication time and solvent ratio were selected. According to the experimental results, the effective yield of pinosylvin increased with the increase of ultrasonic power and sonication time and the decrease of solvent ratio. When the ultrasonic power of 2400 W/L was added to the solution of pulverized pine leaves of 8 g per 1 L of a solvent for 10 minutes, yield of extracts and purity, effective yield and concentration ratio of pinosylvin were 0.3166 g/g, 0.7247 mg/g, 0.2294 mg/g and 23.0, respectively.