• Journal of radiological science and technology
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• v.43 no.5
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• pp.359-365
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• 2020

This study aimed to investigate the causes of bacterial growth to prevent infection caused by ultrasound gel and gel containers in contact with patients during ultrasonography. To investigate bacterial contamination during manufacturing or storage, we cultured ultrasound gels originally supplied from three manufacturers. To analyze bacterial growth according to the lapse of time and frequency of use of the ultrasound gel container, the gel and container were cultured at regular intervals every week for 4 weeks. In addition, to determine the source of infection, the examiner's hand was inspected with hand plate and the degree of bacterial contamination was measured before the test. As a result of the study, bacteria were not detected in the gel provided at the initial supply, and in the gel and gel container used repeatedly for 4 weeks, the same bacteria residing on the skin were identified in the examiner's hand, such as Staphylococcus epidermidis, Micrococcus luteus, Leuconostoc mesenteroid spp cremoris, Kocuria rhizophila, and etc. Separated strains were classified as those of the low- or non-pathogenicity; however, most of these strains may render fatal consequences to patients of lower level of immunity due to acquired tolerance to antibiotics. At week 1, when the number of tests was the highest, 44 colonies were identified, and at week 4, when the number of tests was the lowest, 4 colonies were identified. As r=0.994, it was found that the number of colonies increased as the number of tests increased. In conclusion, it was confirmed that the cause of the infection was not the ultrasound gel, but the examiner's hand. The ultrasound gel or gel container may be contaminated by skin flora of examiner's hands, which can cause opportunistic infection in patients with low immunity. The ultrasound gel or gel container may be contaminated by skin flora of examiner's hands, which can cause opportunistic infection in patients with low immunity. Therefore, it was confirmed that thorough hand disinfection was necessary to block healthcare-associated infections.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.78-82
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• 1984

Effects of various drying conditions of agar gel on the physico-chemical properties of dried agar were investigated. For drying of the agar gel$(1.0{\times}1.0{\times}34.0cm)$ by means of sun drying, simple solar drying, hot-air drying ($30^{\circ}C$, control, natural convection), hot-air drying ($30^{\circ}C$, pretreatment, natural convection) and freeze drying, it took 96, 75, 67, 50 and 21 hours, respectively. The gel strengths of dried agar gel prepared by sun drying, solar drying, freeze drying and spray drying were320, 370, 270 and $360g/cm^2$, respectively and that of hot air-dried agar gel was influenced by drying temperature, pretreatment an mode of heat transfer. The gel strength, the gelation temperature and other quality index of spray-dried agar were not inferior to those of sun-dried agar, but it was not expected to be economical because of it recovery rate. In case of hot air drying, the gel strength value of agar increased as the drying rate increased. No significant differences among various products were noted in the gelation temperature, the melting temperature, the ash and $SO_3$ content.

• Korean Chemical Engineering Research
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• v.55 no.1
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• pp.34-39
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• 2017

In this study, intermolecular crosslinked carboxymethyl cellulose sodium salt (CMC) and porcine Cartilage Acellular Matrix (PCAM) blended hydrogel films for anti-adhesive barriers were prepared by gamma-ray radiation. The effects of the CMC/PCAM concentration and blending ratio on the morphology, gel fraction, gel strength, and degree of swelling were determined. The results indicated that crosslinked CMC/PCAM films show significantly lower the gel-fraction than CMC films. The degree of attachment and proliferation of human vascular endothelial cells on CMC/PCAM films was lower than the CMC films. We show the capacity of the CMC and PCAM to be hydrogel films, and the ability to reduce cell adhesion and proliferation on these films by modification with cell anti-adhesion molecules of PCAM. In conclusion, this study suggests that radiation cross-linked CMC/PCAM hydrogel films endowed with anti-adhesion ligands may allow for improved regulation of cell anti-adhesion behavior for prevent peritoneal adhesions.

• Polymer(Korea)
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• v.33 no.6
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• pp.551-554
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• 2009

Poly (vinyl alcohol) (PVA) and carboxymethyl cellulose (CMC) have received increasing attention in biomedical and biochemical applications because of their properties such as being water-soluble and biocompatible. In this study, a PVA/CMC hydrogel applicable to artificial cartilage was prepared by a freezing-thawing technique and a gamma-ray irradiation. The solid concentration of PVA was 7 wt% and the concentration of CMC was 4 wt%. The freezing/thawing process was repeated twice and the dose of gamma-ray irradiated was 30 kGy. Results of gelation before and after gamma-ray irradiation were similar, but the swelling degree decreased and compressive strength increased. The cytotoxicity was investigated with CCK-8 assay.

• Polymer(Korea)
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• v.28 no.3
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• pp.211-217
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• 2004

The sol to gel transition of aqueous solution of block copolymers consisting of methoxy poly (ethylene glycol) (MPEG) and biodegradable polyesters such as $\varepsilon$-caprolactone and L-lactide was investigated as a function of temperature. MPEG-PCL was prepared by ring opening polymerization of $\varepsilon$-caprolactone in the presence of HClㆍEt$_2$O as monomer activator at room temperature. Also, MPEG-PLLA was prepared by ring opening polymerization of L-lactide in the presence of stannous octoate at 115$^{\circ}C$. The properties of block copolymers were investigated by $^1$H-NMR, IR, and GPC as well as the observation of thermo sensitive phase transition in aqueous solution. As the hydrophobic block length increased, the sol to gel transition temperature increased and curve of that steepen to lower concentration. To confirm the gel formation at body temperature, we observed the formation of gel in the mice body after injection of 20 wt% aqueous solution of each block copolymer. After surging, we investigated the gelation in mice. The results obtained in this study confirmed the feasibility as biomaterials of injectable implantation for controlled release of drug and protein delivery.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.957-964
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• 2023

This study focused on hand sanitizer as a medium that can replace ultrasonic gel, which is vulnerable to contamination by bacteria that reside on the hand. Hand sanitizer produces a strong sterilization effect from germs resident on the hands through different sterilization principles depending on the ingredients. Select products of gel type, cream type, and foam type, except for liquid type with low viscosity, and ultrasonically apply one 62% ethanol gel type and one cream type, one benzalkonium chloride 0.066% cream type and one foam type, respectively. Using ATS-539 as a medium, image evaluation was performed on the axial and lateral resolution and penetration depth, and the presence or absence of an air layer between the probe and the phantom. As a result, in the evaluation of the axial and lateral resolution and the depth of penetration, all four experimental groups met the evaluation criteria. However, in the case of the foam type, although it was suitable for the evaluation criteria of resolution and penetration depth, dark shadows appeared on both sides except for the center of observation during image evaluation. Through this experiment, it was possible to confirm the possibility that the remaining three types of hand sanitizers except the foam type could replace the ultrasonic gel.

• Digital Contents
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• no.12 s.127
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• pp.60-69
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• 2003

2003년은 디지털콘텐츠 업계에도 주식시장 상장 바람이 강력하게 불었다. 웹젠, 유엔젤, 거원시스템, 지식발전소 등 새롭게 상장된 기업의 수는 적었지만, 웹젠이 코스닥 시장에 상장하면서 일으킨‘대박’이라는 폭풍은 관련 업계 관계자들을 들뜨게 만들었다. 하지만 올해 상장한 기업들이 모두‘한몫’을 잡은 것은 아니다. 올해 주식시장을 뜨겁게 달궜던 디지털콘텐츠 기업들의 성적표를 살펴봤다.

• Proceedings of the Korea Water Resources Association Conference
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• 1992.07a
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• pp.142-150
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• 1992

• 건강소식
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• v.35 no.7
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• pp.16-17
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• 2011

검사 테이블로 바로 누워 해당 검사 부위에 투명한 젤을 바르고 그 위에 초음파 변환기를 대면 모니터에 실시간 이미지가 떠오르고 이를 관찰하면 된다. 짧게는 10분, 길게는 30분이면 충분하다. 이처럼 초음파검사는 간편할 뿐만 아니라, 별다른 고통 없이 여러 질병을 진단할 수 있다.

• Proceedings of the Materials Research Society of Korea Conference
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• 1997.10a
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• pp.93-93
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• 1997