• Archives of Plastic Surgery
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• 제38권1호
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• pp.1-6
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• 2011

Purpose: Currently, soft tissue filler products based on hyaluronic acid are widely used. They are safe, effective, and convenient to use compared with bovine collagens. However, all commercially available hyaluronic acid based fillers in Korea are imported ones. The purpose of this study is to evaluate efficacy of a new hyaluronic acid filler (HyaFilia; CHA bio&Diostech Co., Seoul), which has been recently developed in Korea. Methods: Three kinds of soft tissue fillers, including Restylane (Q-Med, Uppsala, Sweden), HyaFilia (CHA bio & Diostech Co., Seoul), Juvederm (Allergan, CA, USA), were injected subdermally into the back of hairless mice at six sites. The 2 cephalic sites composed Restylane groups, the 2 middle sites HyaFilia groups, and the 2 caudal sites Juvederm groups. Six hairless mice were included in the study, therefore, a total of 12 injections per group were performed. After 16 weeks after injection, the nodular swellings that resulted from the injections were excised wide enough to include skin beyond the swelling points down to the panniculus carnosus layer using 8mm punches. Volumes and weights were measured using a stereoimage optical topometer system and a weighting machine. Histologic comparisons were also carried out. Results: The mean volumes of the Restylane, HyaFilia and Juvederm groups were $3698{\times}103$, $4820{\times}103$, and $1435{\times}103$ PI, respectively. The mean weights of the Restylane, HyaFilia and Juvederm groups were 36.08, 37.83, and 24.66 mg, respectively. Histologic examination between the 3 groups showed no significant difference in tissue compositions and inflammatory reactions. Conclusion: The results of this study shows that HyaFilia is superior to Restylane and Juvederm in longavity of filling effect. Therefore, HyaFilia may be an effective replacement for the imported materials including Restylane and Juvederm.

• Membrane and Water Treatment
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• 제1권3호
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• pp.207-214
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• 2010

Approximately 80% of water used in urban areas reappears as municipal wastewater (MWW). Reclamation of MWW is an attractive proposition under the present scenario of water stressed cities in India. In this paper, we attempted to reclaim MWW using lab-scale hollow- fiber (HF) membrane modules for possible reuse in non-potable applications. Experiments were conducted to evaluate the efficiency of virgin HF ($M_1$) and modified HF ($M_2$) modules. The $M_2$ module consists of HF modified with a skin layer formed through interfacial polymerization of m-phenylenediamine with trimesoyl chloride (MPD-TMC). The molecular weight cut-off (MWCO) of $M_1$ was 44000 g/mol and that of $M_2$ 10000 -14000 g/mol on the basis of rejection of polyethylene glycol. The combination of $M_1$ and $M_2$ modules was able to reduce concentrations of most of the pollutants in sewage and improved the treated water quality to the acceptable limits for non potable reuse applications. It is found that about 98-99% of the initial flux is recovered by the backwashing process, which was approximately two times in a month when operated continuously.

• 한국어류학회지
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• 제18권2호
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• pp.87-96
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• 2006

이사천에서 채집된 칼납자루의 생식과 기관계 구조를 조직학적인 방법에 의하여 조사한 결과는 다음과 같다. 암:수 성비는 1:1로 나타났다. 암컷의 경우 생식소중량지수(GSI)는 12월과 4월에 두 번의 정점을 나타냈으며, 산란관지수(OLI)는 불규칙한 변화 양상을 보였다. 기관계의 조직학적인 관찰 결과, 피부에서는 상피층의 위축과 색소세포의 증가가 확인되었으며, 아가미에서는 새판 상피층의 박리와 새엽의 분지현상이 나타났다. 그리고 간과 신장에서는 울혈 및 간세포의 세포질 변성과 사구체의 팽창, 세뇨관 상피세포의 초자성 변성 및 간질세포의 핵 응축이 관찰되었다.

• 한국의류학회지
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• 제20권1호
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• pp.228-238
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• 1996

The purpose of this study was to evaluate the effect of chacteristics of knit fabrics on the microclimate of the skin simulating system. To determine the effect of characteristics of knit fabrics, vapor state of sweat pulse was simulated in the closed system. Different contents of fibers such as cotton, wool and polyester with different yarn size and knit types were chosen for specimens. The changes of humidity and temperature of air layer in the simulated systems were measured. Buffering indices, $K_d$ and $\beta_r$, were determined by considering $\alpha_p, \DeltaP_{max}, t_{max}, and tan\beta$. Physical properties of knit fabrics such as thickness, porosity, air resistance and moisture vapor transport were measured. Results showed that vapor pressure of wool was lower than cotton or polyester This was attributed to the hydrophilicity of wool which absorbed moisture rather quickly and retained in the knit fabric. The time to decrease vapor pressure was faster for polyester than cotton or wool. As a result, $K_d$ was in the order of wool> polye, item> cotton. $\beta_r$ of wool was rower than cotton or polyester due to its lowers porosity and slower desorption rate. For the yarn size, $K_d$ was in the order of 80's> 60's> 30's; thinner and lighter yarn showed better water vapor transport property. For knit type, buffering capacity of single jersey was better than interlock knit fabric. Statistical analysis showed that the air permeability was the most influential factor far the water vapor transport properties.

• 공업화학
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• 제10권4호
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• pp.515-522
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• 1999

상분리 방법으로 비대칭 폴리에테르이미드막을 제조하였고, 수산화나트륨 수용액으로 막의 표면층을 개질 했을 때의 몰폴로지 변화를 반응기간과 반응용액 농도에 대하여 살려보았다. 표면층 몰폴로지는 개질 용액의 농도가 증가함에 따라 치밀한 구조에서 둥근 입자상의 형태로 변화되었고, 개질 시간이 증가될수록 치밀 영역이 증가되었다. 그러나 반응 농도가 아주 높거나 장시간 개질을 하면 비대칭 폴리에테르이미드막의 표면에서 치밀 구조층이 없어지는 결과를 나타냈다. 결과적으로, 표면의 몰폴로지는 개질 용액의 농도와 시간에 따라 크게 좌우됨을 알 수 있었다. 이러한 결과는 폴리에테르이미드가 수산화나트륨에 의해서 폴리아믹산으로 가수분해되면서 나타나는 현상으로 추측되었다.

• 한국초전도ㆍ저온공학회논문지
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• 제15권2호
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• pp.20-23
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• 2013

For sensitive measurements of micro-Tesla nuclear magnetic resonance (${\mu}T$-NMR) signal, a low-noise superconducting quantum interference device (SQUID) system is needed. We have fabricated a liquid He dewar for an SQUID having a large diameter for the pickup coil. The initial test of the SQUID system showed much higher low-frequency magnetic noise caused by the thermal magnetic noise of the aluminum plates used for the vapor-cooled thermal shield material. The frequency dependence of the noise spectrum showed that the noise increases with the decrease of frequency. This behavior could be explained from a two-layer model; one generating the thermal noise and the other one shielding the thermal noise by eddy-current shielding. And the eddy-current shielding effect is strongly dependent on the frequency through the skin-depth. To minimize the loop size for the fluctuating thermal noise current, we changed the thermal shield material into insulated thin Cu mesh. The magnetic noise of the SQUID system became flat down to 0.1 Hz with a white noise of 0.3 $fT/{\surd}Hz$, including the other noise contributions such as SQUID electronics and magnetically shielded room, etc, which is acceptable for low-noise ${\mu}T$-NMR experiments.

• KSBB Journal
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• 제17권2호
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• pp.176-181
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• 2002

Astaxanthin (3,3＇-dihydroxy-${\beta}$, ${\beta}$-carotene-4-4＇-dione), a natural pigment of pink to red color, is widely distributed in nature particularly in the skin layer of salmonoids and the crust of shrimp, lobster, etc. Recently, it was produced from the yeast culture of Phaffia rhodozyma. Because of its high thermal stability and antioxidant functionality, its applications can be extended into food, cosmetics, and pharmaceutical ingredient beyond the traditional feed additive. Because of its very high lipophilicity, astaxanthin has been extracted traditionally by strong organic solvents such as chloroform, petroleum ether, acetone, etc. In this study, we developed a surfactant-based solubillization system for astaxanthin, and used it to extract astaxanthin from disrupted yeast cells. Among Tween 20, Triton X-100 and SDS, Tween 20 was identified as the most suitable surfactant in terms of extraction capacity and safety. The ethylene oxide group of Tween 20 was identified as the most significant factor to increase the HLB value that determined the extraction capacity. The effects of micelle formation condition, such as the molar ratio of astaxanthin and Tween 20, pH, and ionic strength were also investigated. pH and ionic strength showed no significant effects. The optimal molar ratio between astaxanthin and Tween 20 was 1 : 12. Antioxidant activity of astaxanthin was higher than ${\beta}$-carotene and ${\alpha}$-tocopherol. Astaxanthin in the crude extract from the yeast cell was more resistant to air and/or light degradation than pure astaxanthin, probably because of the presence of other carotenoids and lipids.

• Composites Research
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• 제27권3호
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• pp.96-102
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• 2014

본 연구에서는 황마 단섬유 강화 폴리유산을 코어 폼으로 하고 연속 유리 섬유 강화 폴리유산을 외곽 스킨으로 하는 샌드위치 패널 구조의 황마 단섬유 강화 폴리유산 복합재료를 제작하였고, 황마 섬유 무게 비에 따른 복합재의 굽힘 특성을 관찰하였다. 코어 폼의 밀도는 0.31-0.67 $g/cm^3$ 기공함량비는 0.51-0.71이었다. 최대 굽힘강도는 황마 섬유 무게비 12.5 wt.%에서 92.7 MPa, 최대 굽힘 탄성계수는 황마 섬유 무게비 30.0 wt.%에서 7.58 GPa 으로 측정되었다. 경제성 분석을 실시했으며 적용 부재의 굽힘 강도를 향상시키기 위한 비용은 황마 섬유 무게 비가 12.5 wt.%일 때 $0.010USD/m^3/MPa$로 계산되었다.

• 멤브레인
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• 제8권1호
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• pp.29-41
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• 1998

수용상 MPD(m-phenylene diamine)와 유기상 TMC(trimesoyl chloride)를 사용하여 역삼투 복합막의 활성층 고분자인 aromatic polyamide 제조를 행하고 그 성능을 고찰하였다. 또한 polysulfone 다공성 지지막 위에 박막을 회분, 연속식으로 계면중합 제조한 후, 제조변수에 따른 역삼투 성능을 비교하였다. 회분식으로 복합막을 제조한 결과 유기상 용매의 종류, 단량체의 농도와 함침시간, 열처리 온도, 중화제, 알코올 후처리, 산 후처리 등에 의해 다양한 성능을 나타내었다. 이때, 투과량 향상에는 알코올 후처리 효과가, 또 선택도의 향상에는 단량체의 농도와 함침시간이 변수이었다. 최적조건에서 연속식 공정으로 막모듈을 제조하여 NaCl 5,000 ppm, $25kg_f/cm^2$에서 상용막과 비교할때, 투과량은 33% 증가하고 배제율은 5% 감소하였다.

• 멤브레인
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• 제24권1호
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• pp.50-62
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• 2014

상 전이 공정을 이용하여 polysulfone계 비대칭 정밀 여과막을 제조하였다. Polysulfone/N-methyl-2-pyrrolidone/polyvinylpyrrolidone/phosphoric acid계로 이루어진 casting 용액을 사용하였으며 응고조로는 물을 사용하였다. 멤브레인 제조공정에 적용된 상 전이 공정으로 증기 유도 상 전이 공정을 적용하였으며 상대습도 74%에서 캐스팅 판의 온도와 노출 시간을 조절한 결과 기공의 크기와 구조에 있어 변화를 관찰할 수 있었다. 제조된 멤브레인의 구조는 SEM과 microflow permporometer를 사용하여 조사하였다. Phosphoric acid의 첨가는 조밀한 스펀지 형태의 멤브레인을 느슨한 스펀지 형태의 멤브레인으로 변화시켰으며 촉매량의 Phosphoric acid 첨가로도 평균 기공크기는 거의 $0.2{\mu}m$ 정도 커지고 유량도 약 3,000 LMH가 증가하였다. 캐스팅 판의 온도와 노출 시간의 변화는 표면층의 구조, 기공의 크기 및 공극률에 큰 변화를 가져옴을 확인할 수 있었다.