• 제목/요약/키워드: Wall adhesion

검색결과 146건 처리시간 0.032초

쥐 맹장/복벽 찰과상 모델에서 Sodium Hyaluronate/sodium Carboxymethyl Cellulose 멤브레인의 수술 후 유착방지에 대한 유효성 평가 (Evaluation on Effectiveness for Preventing Post Surgical Adhesion of Sodium Hyaluronate/Sodium Carboxymethyl Cellulose (HA/CMC) Membrane in Rat Cecum/Peritonium Model)

  • 이영무;이영우
    • 멤브레인
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    • 제15권3호
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    • pp.213-223
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    • 2005
  • 본 연구에서는 히알루론산나트륨/카르복시메틸셀룰로오스나트륨(HA/CMC)으로 구성된 유착방지 막을 제조하였고, 쥐에서 유착방지용에 대한 효과를 평가하였다. 유착방지 막은 HA/CMC 용액을 동결건조한 후 1-에틸-3-(3-디메틸아미노프로필)카보디이미드 (EDAC)로 가교하여 제조하였다. Sprague-Dawley쥐의 맹장/복벽 찰과상 모델에서 복부 중앙선 절개 후 장막과 복벽을 bone burr로 $1\times2\;(cm^2)$ 크기로 찰과상을 만들고, 상처 면 주위의 3곳을 봉합사로 고정시켰다. 상처난 장을 실험군의 경우 HA/CMC 막으로 덮어주었으며, 대조군은 아무처치도 하지 않은 상태로 복벽을 마주보게 하였다. 대조군의 대부분은 수술 후 7, 14, 21, 28일에 유착정도 3 이상을 나타내었고, 반면 실험군의 $60\~70\%$는 수술 후 14, 21, 28일에 유착정도 2 이하를 나타내었다. 이는 유착세기에서도 유사하였다. 일반적으로 유착정도와 유착세기는 수술 후 14일까지 점차 증가하였고, 수술 후 21일에는 거의 동일하거나 약간 증가하였으며, 28일째에는 감소하였다. 대조군은 유착정도와 유착세기, 유착면적에서 높은 수치를 나타내었다. 이 유착방지막은 수술 후 유착방지에서 좋은 임상결과를 나타낼 수 있을 것으로 기대된다.

다양한 곡률에 안정적인 등반 로봇을 위한 건식 점착물질의 실험기반 설계변수 최적화 (Optimization Design of Dry Adhesion for Wall-Climbing Robot on Various Curvatures Based on Experiment)

  • 유연형;신명석;서태원
    • 한국생산제조학회지
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    • 제23권4호
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    • pp.398-402
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    • 2014
  • This paper presents the results of a study on the optimal footpad design for vertical climbing on acrylic surfaces with various curvatures used Taguchi methods. For a climbing robot, the adhesion system plays an important role in the climbing process. Only an appropriate adhesion strength will prevent the robot from falling and allow it to climb normally. Therefore, the footpad is a significant parameter for a climbing robot and should be studied. Taguchi methods were used to obtain a robust optimal design, where the design variables were the flat tacky elastomeric shape, area, thickness, and foam thickness of the footpad. Experiments were conducted using acrylic surfaces with various curvatures. An optimized footpad was selected based on the results of the experiments and analysis, and the stability of the wall-climbing robot was verified.

The Binding of Aflatoxin $B_1$ Modulates the Adhesion Properties of Lactobacillus casei KCTC 3260 to a HT29 Colon Cancer Cell Line

  • Hwang, Kwon-Tack;Lee, Won-Jae;Kim, Gye-Yeop;Lee, Shin-Kyung;Lee, Jeong-Min;Jun, Woo-Jin
    • Food Science and Biotechnology
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    • 제14권6호
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    • pp.866-870
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    • 2005
  • The 14 lactic acid bacteria (LAB) have been evaluated to determine the binding capacity to HT29 cell and Aflatoxin $B_1$ ($AFB_1$). The interaction of LAB to HT29 cells has been further investigated to identify the possibility of competing the binding sites with $AFB_1$. Of 14 LAB strains, Lactobacillus casei KCTC 3260 demonstrated the higher adhesiveness to HT29 and $AFB_1$ with the rate of 19.6% and 46.3%, respectively. In competitive analysis for binding sites, the adhesion of L. casei KCTC 3260 to HT29 cells was reduced with 100 nmol $AFB_1$ by 31.2%. The protoplast of L. casei KCTC 3260 showed no binding capacity to HT29 cells with increment of $AFB_1$ concentration, indicating that cell wall components might serve as a critical factor for the binding. To discriminate the major component influencing on L. casei KCTC 3260 binding to HT29 cells and $AFB_1$, four different pre-treatments (lipase, pronase E, sodium m-periodate, and urea) were employed. Of those, sodium m-periodate treatment caused the lower adhesion of L. casei KCTC 3260 to HT29 cells with the increment of $AFB_1$ concentration. These results indicated that carbohydrate moiety on the cell wall of L. casei KCTC 3260 might be the most critical component in binding to both HT29 cells and $AFB_1$.

교반동력에 의한 기능성 물질 함유 수용액의 빙부착 평가 (Evaluation of Ice Adhesion in an Aqueous Solution with Functional Materials by Stirring Power)

  • 승현;백종현;홍희기;강채동
    • 설비공학논문집
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    • 제16권8호
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    • pp.720-727
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    • 2004
  • In the process of ice-slurry making, the phenomenon of ice adhesion influences extremely to ice making system. In this study, the effect on the ice adhesion by thermal storage material with additives is investigated quantitatively. Various solutions of 300 g in a stainless vessel were frozen under stirring. Through the experiment the ice adhesion between cooling wall and ice-slurry was compared with each other by measuring the stirring power. From the experiment, the stirring power in EG, SCA solution was smaller than those in the solution containing functional materials, such as poly-vinyl-alcohol or kitchen detergent.

Degradation of Epoxy Coating due to Aging Acceleration Effects

  • Nah, Hwan Seon;Lee, Chul Woo;Suh, Yong Pyo
    • Corrosion Science and Technology
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    • 제5권3호
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    • pp.99-105
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    • 2006
  • This paper is to investigate feasibility on quantitative aging state of epoxy coating on concrete wall in containment structure under operation of nuclear power plants. For evaluating the physical characteristics of the epoxy coating, adhesion strengths of two kinds of degraded epoxy coating systems on both steel surfaces and concrete surfaces were measured via accelerated aging. Comparatively impedance data taken by ultrasonic test were also taken to relate with adhesion data. After aging, in case of concrete, from half of specimens, aging of epoxy coating was developed. As for steel, on $4^{th}$ inspection day, adhesion force was failed. To improve reliability on quality degradation of epoxy, relationship between adhesion and impedance was analyzed. By tracing to co-respond to these data, it was possible to Fig. out physical state of as-built epoxy coating. The possibility to develop new methodology of time - dependent aging state on epoxy coating was found and discussed.

Comparison Study of Thermal Decomposition Characteristics of Wattle & Pine Tannin-based Adhesives

  • Kim, Sumin;Lee, Young-kyu;Kim, Hyun-Joong;Eom, Young Geun
    • Journal of the Korean Wood Science and Technology
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    • 제30권3호
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    • pp.34-41
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    • 2002
  • This study investigated the thermogravimetric analysis of two types of cured tannin-based adhesives from wattle and pine, with three hardeners of paraformaldehyde, hexamethylenetetramine and TN (tris(hydroxyl)nitromethan), at a temperature of 170℃ and a heating rate of 5, 10, 20 and 40℃/min for 10 minutes. The 5 minutes cured wattle tannin-based adhesive with each hardener at 170℃ was also tested to compare the degree of curing. It was found that thermogravimetric analysis could be used to measure the degree of curing of a thermosetting adhesive. The TG-DTG curves of all the adhesive systems were similar and showed three steps in a similar way to a phenolic resin. This means that each adhesive system is well cross-linked. However, a high thermal decomposition rate was shown at 150 to 400℃ in the case of the pine tannin sample with TN (tris(hydroxyl)nitromethan). The Flynn & Wall expression was used to evaluate the activation energy for thermal decomposition. As the level of conversion (𝛼) increased, the activation energy of each system increased. The activation energy of the wattle tannin-based adhesive with paraformaldehyde was higher than the others.

수용액의 교반/냉각을 동반한 슬러리 얼음의 빙부착 (Adhesion of Ice Slurry in an Aqueous Solution Cooling with Stirring)

  • 강채동;손권;백종현;홍희기
    • 설비공학논문집
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    • 제14권12호
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    • pp.1071-1077
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    • 2002
  • Ice adhesion on cooling wall is very important in continuous ice formation. The purpose of the present study is to investigate the possibilities of a three-component aqueous solution as a thermal storage material for the continuous ice formation. By freezing under stirring the solution of 300 mL in a stainless steel vessel which was immersed and cooled in a temperature controlled bath, an ice slurry was formed experimentally with measuring the temperature and stirring load variation. From the experiment, the ice adhesion was suppressed when the supercooling degree decreased and the concentration of aqueous solution increased.

시멘트와 변성 폴리머를 혼합한 프라이머의 콘크리트 함수율에 따른 부착성능 비교 (Comparison of Adhesion Performance According to Concrete Moisture Content of Primer Mixed with Cement and Modified Polymer)

  • 강효진;안기원;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2019년도 추계 학술논문 발표대회
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    • pp.231-232
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    • 2019
  • In this study, primers were prepared by mixing cement and modified polymer, and the adhesion to the substrate surface was enhanced by using cement which is the same material as the basement outer wall. The improved primer is used to verify the adhesion performance of the substrate in wet concrete environments.

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Phenotypic and Cell Wall Proteomic Characterization of a DDR48 Mutant Candida albicans Strain

  • El Khoury, Pamela;Salameh, Carell;Younes, Samer;Awad, Andy;Said, Yana;Khalaf, Roy A.
    • Journal of Microbiology and Biotechnology
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    • 제29권11호
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    • pp.1806-1816
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    • 2019
  • Candida albicans is an opportunistic fungus possessing multiple virulence factors controlling pathogenicity. Cell wall proteins are the most important among these factors, being the first elements contacting the host. Ddr48 is a cell wall protein consisting of 212 amino acids. A DDR48 haploinsufficient mutant strain was previously found necessary for proper oxidative stress response and drug resistance. In this study, we aimed to further elucidate the role of Ddr48 by performing additional phenotypic characterization assays. A combinatory proteomic and bioinformatics approach was also undertaken to determine differentially expressed cell wall proteins. Results showed that the mutant strain exhibited a 10% decrease in adhesion mirrored by a 20% decrease in biofilm formation, and slight sensitivity to menadione, diamide, and SDS. Both strains showed similar hyphae formation, virulence, temperature tolerance, and calcofluor white and Congo red sensitivities. Furthermore, a total of 8 and 10 proteins were identified exclusively in the wild-type strain grown under filamentous and non-filamentous conditions respectively. Results included proteins responsible for superoxide stress resistance (Sod4 and Sod6), adhesion (Als3, Hyr4, Pmt1, and Utr2), biofilm formation (Hsp90, Ece1, Rim9, Ipp1, and Pra1) and cell wall integrity (Utr2 and Pga4). The lack of detection of these proteins in the mutant strain correlates with the observed phenotypes.

표면특성 변화에 따른 유류분해 미생물의 토양내 거동성 조절

  • 류두현;목지예;최상일;김용미;이경애
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2003년도 추계학술발표회
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    • pp.360-362
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    • 2003
  • The adhesion of hydrocarbon degrading bacteria(HDB) differing in surface hydrophobicity was investigated. Cell wall hydrophobicity was modified chemically and physiologically. Modified adhesion deficient mutant of HDB was selected in a soil column assay Physiologically and chemical modification increased cell surface hydrophobicity. Cell surface charcteristis including BATH and zeta potential were measured. Physiological modification using ampicillin was not stable, but chemical modification was stabel. Hydrocarbon degrading potential was measured for modified and unmodifed HDB.

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