• 한국기계가공학회지
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• 제21권5호
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• pp.105-109
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• 2022

In the field of medical and marine industries, antibacterial surfaces have been emerged as one of the most important issues. Recently, many researchers have been studying antibacterial surfaces to kill bacteria or prevent the adhesion of bacteria. In their researches, various materials and structures are suggested to inhibit the adhesion of bacteria or kill the attached bacteria. However, chemical materials such as antibiotics or metal could be toxic. Moreover, frequent use of antibiotics causes super bacteria having resistance to antibiotics. In this study, nano-pillar structured surface was fabricated using polyurethane acrylate (PUA) and the mechanically induced antibacterial function was confirmed based on the fabricated nanostructures. Nanostructures can damage the bacterial membrane of Gram-negative bacteria through stretching of bacterial membrane via interaction with the nanostructures and the bacterial membrane. Consequently, the proposed transparent, flexible and nanostructured PUA films can be one of promising candidates for antifouling and antibacterial surfaces which can be applied in various industries.

• Macromolecular Research
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• 제12권4호
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• pp.342-351
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• 2004

Poly(ethylene glycol) (PEG1K) and sulfonated PEG (PEG1K-SO$_3$) methacrylate (MA) copolymers have been prepared and characterized. The structures of the synthesized copolymers were confirmed by $^1$H and $^{13}$ C NMR spectroscopy and elemental analysis. The bulk characteristics of the copolymers were evaluated by viscosity and thermal analysis. The surface properties of the copolymers were investigated using dynamic contact angle measurements and electron spectroscopy for chemical analysis. The hydrophilicity of the surfaces modified with PEG1KMA or PEG1K-SO$_3$MA increased, possibly as a result of the orientation of the hydrophilic PEG1KMA/PEG1K-SO$_3$MA chains into the water phase. Platelets adhered less to the surfaces of the copolymers than they did to a polyurethane control. In addition, adhesion of platelets to the copolymer surfaces decreased upon increasing the chain density of PEG1KMA and sulfonated PEG1KMA in the copolymers. Both bacterial adhesion and protein adsorption were significantly reduced on the copolymer surfaces and their levels differ depending on the kind of surface or media.

• Restorative Dentistry and Endodontics
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• 제25권1호
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• pp.116-122
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• 2000

On the instrumented root canal wall, amorphous, irregular smear layer can be observed with Scanning Electron Microscope(SEM). The purpose of this study was to evaluate the effect of the presence or absence of smear layer on the adhesion of Staphylococcus aureus to the dentin of the root canal. Human incisors, extracted within 7 days, with no caries, no fracture, no calcification of canal, were selected. After cutting crown portion at cemento-enamel junction, root canal preparation was done by modified crown-down technique using Profile and Gates - Glidden Drill. During canal preparation, 10ml physiologic saline solution(group1&3) or 10ml 3.5% NaOCl(group2&4) was used as irrigation solution. And 10ml physiologic saline solution(group1&3) or 10ml 0.5M EDTA(group2&4) was applicated for final flush. After vertical sectioning and ethylene oxide gas sterilization, samples(group1&2) were immersed into BHIYHM broth inoculated with Staphylococcus aureus (ATCC 31153) and incubated for 3hrs at $37^{\circ}C$. All samples were prepared for and observed with SEM(JEOL JSM840S). The data were analyzed by Mann-Whitney rank sum test. The conclusions are as follows ; 1. Smear layer covers entire root canal surface after root canal preparation. 2. Smear layer has been removed away and the entrances of dentinal tubules have opened widely, when applying 0.5M EDTA and 3.5% NaOCl. 3. A significantly higher number of bacteria were adhered to the root canal dentin without smear layer(p<0.0001). 4. Smear layer produced during root canal preparation impedes bacterial adhesion and colonization to dentin matrix, therefore inhibits canal reinfection.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2004년도 International Meeting of the Microbiological Society of Korea
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• pp.137-139
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• 2004

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.103-116
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• 1996

This study was performed to observe the bacterial adhesion and penetration to e-PTFE membrane following guided tissue regeneration(GTR) procedure and to evaluate the association of the membrane exposure and bacterial contamination with the clinical outcome. For the study, ten infrabony defects in 9 patient were treated by mucoperiosteal flap operation including placement of the e-PTFE membrane. The treated teeth were monitored weekly for the membrane exposure, gingival recession and gingival inflammation. The membranes were retrieved after 4 to 6 weeks, examined by SEM for bacterial contamination and adherent connective tisue elements, and observed under LM for the bacterial penetration into membrane. Three months postsurgery, the defect sites were clinically reexamined for the changes in attachment level and probing depth. Comparison of the ultrastuctural findings and clinical outcome revealed that extent of membrane exposure and bacterial contamination of the membrane was inversely associated with clinical attachment gain. From this finding, the extent of membrane exposure and the bacterial contamination on the apical portion of the e-PTFE membrane at the time of removal seemed to be a critical determinant on the clinical outcome of GTR and the membrane exposure needs to be controlled for optimal results.

• Asian-Australasian Journal of Animal Sciences
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• 제20권9호
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• pp.1397-1401
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• 2007

An in situ experiment was conducted to find out whether Tween 80 improves rice straw digestion through increased adhesion of major fibrolytic bacteria. Rice straw was sprayed with various levels of Tween 80 non-ionic surfactant or SDS ionic surfactant 24 h before incubation in the rumen of Holstein steers. Dry matter (DM) disappearance and adhesion of F. succinogenes, R. flavefaciens and R. albus on rice straw after in situ incubation were measured by real-time PCR. Application of Tween 80 increased DM disappearance, which was more noticeable at an application level of 1% compared to lower application levels. Application of SDS resulted in an opposite response in DM disappearance with highest reduction in DM disappearance at 1% level. In a subsequent in situ experiment, higher Tween 80 was applied to rice straw in an attempt to find the optimum application level. Tween 80 at 2.5% gave better DM disappearance than 1% with a similar result at 5%. Therefore, an adhesion study was carried out using rice straw treated with 2.5% Tween 80. Our results indicated that Tween 80 reduced adhesion of all three major rumen fibrolytic bacteria to rice straw. Present data clearly show that improved DM disappearance by Tween 80 is not due to increased bacterial adhesion onto substrates.

• Journal of Ginseng Research
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• 제45권1호
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• pp.75-85
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• 2021

Background: Invasive infections due to foodborne pathogens, including Salmonella enterica serovar Typhimurium, are prevalent and life-threatening. This study aimed to evaluate the effects of ginsenoside Rg3 (Rg3) on the adhesion, invasion, and intracellular survival of S. Typhimurium. Methods: The impacts of Rg3 on bacterial growth and host cell viability were determined using the time kill and the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays, respectively. Gentamicin assay and confocal microscopic examination were undertaken to determine the effects of Rg3 on the adhesive and invasive abilities of S. Typhimurium to Caco-2 and RAW 264.7 cells. Quantitative reverse transcription polymerase chain reaction was performed to assess the expression of genes correlated with the adhesion, invasion, and virulence of S. Typhimurium. Results: Subinhibitory concentrations of Rg3 significantly reduced (p < 0.05) the adhesion, invasion, and intracellular survival of S. Typhimurium. Rg3 considerably reduced (p < 0.05) the bacterial motility as well as the release of nitrite from infected macrophages in a concentration-dependent manner. The expression of genes related to the adhesion, invasion, quorum sensing, and virulence of S. Typhimurium including cheY, hilA, OmpD, PrgK, rsgE, SdiA, and SipB was significantly reduced after Rg3 treatment. Besides, the compound downregulated rac-1 and Cdc-42 that are essential for actin remodeling and membrane ruffling, thereby facilitating Salmonella entry into host cells. This report is the first to describe the effects of Rg3 on "trigger" entry mechanism and intracellular survival S. Typhimurium. Conclusion: Rg3 could be considered as a supplement agent to prevent S. Typhimurium infection.

• 대한소아치과학회지
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• 제47권2호
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• pp.188-195
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• 2020

이 연구는 새롭게 개발된 알카자이트 재료인 Cention N에 finishing처리를 한뒤에 표면 거칠기와 박테리아 부착에 대하여 조사하고자 함이다. 레진강화형 글래스아이오노머와 컴포짓트 레진, 알카자이트 재료를 원통형의 디스크 형태로 제작하였다(n = 48). 이 후 대조군과 3가지 카바이드버, 미세다이아몬드 버, 화이트스톤버의 피니싱 버에 따른 4가지 하위군으로 분류하였다. 표면 거칠기는 atomic force microscope으로 조사하였으며 표면관찰은 scanning electron microscope을 이용하여 진행하였다. 우식원성 미생물인 streptococcus mutans의 시편 부착을 위하여 CDC biofilm reactor를 사용하여 바이오필름을 배양한후 집락형성단위를 측정하였다. 레진과 Cention N의 아무처리 하지 않은 컨트롤 군의 표면 거칠기는 통계적으로 유의하게 피니싱 처리된 시편들보다 거칠었다. 하지만 표면 거칠기와 미생물 부착사이의 상관관계는 매우 약했다(PCC = 0.13). RMGI와 Cention N은 레진시편에 비해 미생물 부착이 적게 일어났다. Cention N은 피니싱만으로도 임상적으로 허용되는 수준인 0.2 ㎛ 이하의 거칠기를 보였으며 이온 방출 성질로 미생물 부착이 레진과 비교시 적은 것을 확인할수 있었다.

• Neonatal Medicine
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• 제25권4호
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• pp.191-195
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• 2018

Leukocyte adhesion deficiency is a rare primary immunodeficiency and autosomal recessive disorder caused by a mutation in the gene encoding CD18, which is a constituent of leukocyte integrins. Clinical features usually begin with a delay in the separation of the umbilical cord in the neonatal period, and are characterized by marked leukocytosis with infection, delayed wound healing, and repeated bacterial and fungal infections. We experienced a case of leukocyte adhesion deficiency diagnosed in the neonatal period, in which a late preterm infant admitted to neonatal intensive care unit presented with a septic hip. Flow cytometry analysis of whole blood showed a decrease in the expression of CD11b/CD18. This is the first case of leukocyte adhesion deficiency with neonatal septic hip diagnosed in Korea.

• 대한토목학회논문집
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• 제29권3B호
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• pp.303-310
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• 2009

천연 제올라이트는 효과적인 다공성 구조와 높은 양이온 교환능력을 가지고 있을 뿐 만 아니라 비교적 저렴한 가격으로 인하여 흡착제 및 생물막 담체 등으로 널리 사용되는 물질이다. 본 연구에서는 천연 제올라이트를 이용한 생물막 형성시 제올라이트에 흡착된 금속 양이온$(Na^+,\;Ca^{2+},\;Mg^{2+},\;Al^{3+})$이 미생물의 흡착량에 어떠한 영향을 미치는지에 대하여 검토하였다. 본 실험을 위하여 천연 제올라이트의 양이온 교환능력(cation exchange capacity; CEC)의 10%, 20%, 100%를 금속 양이온으로 치환하여 개질시킨 Metal-modified zeolite(MMZ)를 사용하였고 미생물은 Pseudomonas putida를 계대배양하여 사용하였다. 미생물 흡착실험 결과 MMZ로의 미생물의 흡착량이 천연 제올라이트로의 흡착량 보다 일반적으로 증가하는 경향을 나타내었다. 즉, 10% CEC의 경우 미생물의 흡착량은 $Mg^{2+}>natural>Na^+>Al^{3+}>Ca^{2+}$, 20% CEC의 경우 $Mg^{2+}>Ca^{2+}>Al^{3+}>natural>Na^+$, 100%의 CEC의 경우 $Ca^{2+}>Mg^{2+}>natural>Al^{3+}>Na^+$의 흡착량을 나타내었다. 특히, 마그네슘으로 개질된 Mg-modified zeolite(Mg-MZ)의 경우 가장 높은 미생물 흡착량을 보였으며 10% CEC로 개질한 경우 천연 제올라이트보다 60% 이상 증가된 흡착량을 나타내었다. 그러나 제올라이트에 흡착된 양이온의 양이 증가할수록 미생물의 흡착량은 감소되는 경향을 나타내었는데, 즉, 10% CEC Mg-MZ의 경우 미생물의 흡착 증가량이 60% 이상이었으나 20% CEC의 경우 50%, 100% CEC의 경우 10%로 흡착 증가량이 감소되었다. 또한 제올라이트에 흡착된 $Mg^{2+}$와 수용액 상에 존재하는 $Mg^{2+}$가 미생물의 흡착량에 미치는 영향을 비교한 결과 제올라이트에 흡착될 수 있는 미생물의 최대흡착량은 큰 차이가 없는 것으로 조사되었다.