• 대한화장품학회지
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• 제21권1호
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• pp.38-52
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• 1995

Liposome은 의약과 화장품 분야에서 많은 발전을 하였다. 본 연구에서는 세포 간지질의 주요 성분인 cholesterol, palmitic acid, cholesterol ester와 lecithin을 사용하여 swelling반응에 의해 MLV liposome을 제조 하였다. 지질베이스와 마이크로플루다이저를 사용하여 MLV liposome 형성에 대한 특성들을 연구 하였다. MLV liposome은 multilamellar vesicle로서 형성되었다. MLV liposome의 gelation효과는 고온(90$\pm$5도씨)에서 polyol과 water phase에 지질을 혼합한 것에 스웰링 반응을 하였다. MLV liposome에 alpha hydroxy acid 성분들을 투입 제조하였다. MLV liposome의 최적 조건은 마이크로플루다이저에 3회 통과하였으며 vesicle의 입자크기는 150-350nm범위이고 이것을 freeze-fracture electron microscopy로 확인 하였다.

• 대한화장품학회지
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• 제27권1호
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• pp.29-42
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• 2001

We had prepared MLV liposome with Hibiscus Esculentus Ext.(HEE) which have fluorescent light in order to evaluate its percutaneous absorption about hairless rat skin. Then we investigated particle size of MLV using confocal laser scanning microscope(CLSM) and transmission electron microscope(TEM), respectively. Stability of MLV liposome and penetration of MLV liposome to hairless rat skin was measured by CLSM. As a result of experiments, MLV was globular shape and the rage of particle size was 0.3-0.5$\mu\textrm{m}$ mostly. Cream-type MLV had high stability comparatively. When we treated with MLV to rat skin, skin penetration was enhanced, especially, the optimum concentration of MLV on penetration to rat skin was 10%. Optimum penetration time was 6hr-12hr. And MLV-type HEE was more effective on percutaneous absorption than HEE-cream or liposome-type HEE.

• Journal of Veterinary Science
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• 제24권5호
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• pp.54.1-54.13
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• 2023

Background: Porcine reproductive and respiratory syndrome virus (PRRSV) vaccines do not provide full cross-protection, mainly due to the virus genetic variability. Despite this, vaccines based on modified-live PRRSV (PRRSV-MLV) reduce the disease impact. Objectives: To assess the efficacy of two commercial vaccines-one based on PRRSV1 (PRRSV1-MLV) and another on PRRSV2 (PRRSV2-MLV)-against a Japanese PRRSV2 field strain. Methods: Two groups of three-week-old piglets were vaccinated (G1: PRRSV1-MLV; G2: PRRSV2-MLV) and two were kept as non-vaccinated (INF and CTRL). One month later, G1, G2, and INF were challenged with a PRRSV2 field strain. Results: After the challenge, clinical signs were only observed in INF. Moreover, the highest rectal temperatures and values for the area under the curve (AUC) were observed in INF. Regarding viral detection, both AUC and the proportion of positive samples in blood were higher in INF. In G1, viremic animals never reached 100%. At necropsy (21 d after the challenge), differences for titers among groups were only found in tonsils (G1 < G2 and INF). One animal (belonging to G1) was negative in all tissues. Regarding humoral responses, G1 and G2 seroconverted after vaccination, as detected in the corresponding enzyme-linked immunosorbent assay. Specific neutralizing antibodies (NA) against PRRSV1-MLV were already detected at 14 d after vaccination in G1, showing a significant booster after the challenge, while PRRSV2-MLV NA were detected in G2 at the end of the experiment. Conclusions: Despite genetic differences, PRRSV1-MLV has been demonstrated to confer partial protection against a Japanese PRRSV2 strain, at least as good as PRRSV2-MLV.

• 대한화장품학회지
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• 제22권2호
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• pp.99-114
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• 1996

The MLV liposomes have been developed in many drugs and cosmetics fields. The phospholipid base is made from ceramides, cholesterol, cholesteryl ester, lecithin, lanolin ester, and B-sitosterol, and surfactants are made by using (PEG)n-sitosterol(n=5) and K-cetyl phosphate. We made visicles stable by passing samples through Microfludizer and croated multilamellar vesicles to make MLV liposomes similar to the structure of men's skin. In order to make MLV liposomes, we created lipid membrane films which a mixure of phospholipid base and polyol group was reacted above Tc(95$^{\circ}C$) by gelation for 3 hours. As the optimum conditions of Microfluidizer, we figured out 700 bar for the passing pressure of samples, 4$0^{\circ}C$ for its temperature, and 3 times of frequency to pass through samples. Our MLV liposomes is stable on conditions of a low temperature(5$^{\circ}C$) and a high temperature(45$^{\circ}C$), which is not to be split in a large range. We produced our own moisturizing cream which has a good affinity to skin by means of this system.

• 대한화장품학회지
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• 제24권3호
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• pp.123-128
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• 1998

Dihydroxyacetone (DHA) has been used as a self tanning agent and many emulsion formulations containing DHA have been studied. In an emulsion, many factors which have negative effect on DHP and the resultant DHA decomposition can destabilize the emulsion base. In this study, two kinds of emulsion with 5％ DHA were prepared, O/W type emulsion and Multilamellavesicle (MLV) type emulsion to compare the stabilization effects of both emulsions on the DHA. The OHA concentration was analyzed quantitatively by high performance liquid Chromatography (HPLC), also the pH and viscosity of both emulsions were measured for stability. This process was carried out over 4 months. For HPLC, a bondaclone $C_{18}$ column with a mobile phase of distilled water and UV detector were used. The results of these experiment showed that DHA is more stable in an MLV emulsion than it is in an O/W type emulsion.

• Journal of Microbiology
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• 제44권4호
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• pp.447-452
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• 2006

The murine ecotropic retroviral receptor has been demonstrated to function as a mouse cationic amino acid transporter 1(mCAT1), and is comprised of multiple membranespanning domains. Feral mouse (Mus dunni) cells are not susceptible to infection by the ecotropic Moloney murine leukemia virus (MoMLV), although they can be infected by other ecotropic murine leukemia viruses, including Friend MLV and Rauscher MLV. The relative inability of MoMLV to replicate in M. dunni cells has been attributed to two amino acids $(V_{214}\;and\;G_{236})$ located within the third extracellular loop of the M. dunni CAT1 receptor (dCAT1). Via the exchange of the third extracellular loop of the mCAT1 cDNA encoding receptor from the permissive mouse and the corresponding portion of cDNA encoding for the nonpermissive M. dunni receptor, we have identified the most critical amino acid residue, which is a glycine located at position 236 within the third extracellular loop of dCAT1. We also attempted to determine the role of the third extracellular loop of the M. dunni CAT1 receptor with regard to the formation of the syncytium. The relationship between dCAT1 and virus-induced syncytia was suggested initially by our previous identification of two MLV isolates (S82F in Moloney and S84A in Friend MLV), both of which are uniquely cytopathic in M. dunni cells. In an attempt to determine the relationship existing between dCAT1 and the virally-induced syncytia, we infected 293-dCAT1 or chimeric dCAT1 cells with the S82F pseudotype virus. The S82F pseudotype virus did not induce the formation of syncytia, but did show increased susceptibility to 293 cells expressing dCATl. The results of our study indicate that S82F-induced syncytium formation may be the result of cell-cell fusion, but not virus-cell fusion.

• 조명전기설비학회논문지
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• 제24권1호
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• pp.71-77
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• 2010

뇌서지 보호는 오늘날 대부분의 전기전자기기에 있어 중요한 문제 중 하나이다. 그리고 뇌서지 보호를 위한 대다수 SPD의 가장 주요 부품으로 MOV가 사용된다. 본 논문에서는 다양한 타입의 MOV 기반 SPD를 조사하고 낮은 MLV특성의 부작용에 대하여 실험하였다. 실험결과로서 상대적으로 낮은 MLV특성은 실제 현장에서 발생 가능한 TOV 고장 상태하에서 더 큰 고장률로 나타날 수 있으며, 피보호기기보다 우선하여 소손될 수 있음을 알 수 있다. 결국 안전면에서 SPD는 높은 TOV내력과 신속한 단로기의 동작이 요구된다.

• 대한화장품학회지
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• 제22권1호
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• pp.40-59
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• 1996

Retinol은 열과 빛에 쉽게 산화되기 때문에 그 유도체인 Retinyl Palmitate를 사용하고 있으나 이것 또한 안정성이 우려되어 많은 양을 사용하지 못하고 있다. 본 연구에서는 Retinyl Palmitate 5% 와 Tocopgeryl Acetate 10%를 함유한 W/O, W/S, O/W, MLV Type의 크림에서 열적 안정성 및 UV 안정성을 CHROMA METERS로 측정하였으며, $25^{\circ}C$, $45^{\circ}C$에서 RP의 함량을 HPLC로 정량 분석하였다. 또한 RP가 열, 빛 등에 의해서 어떤 물질로 변화하였는지를 측정하였으며, 변화된 물질의 독성에 대한 연구를 하였다. 각각의 크림 TYPE 마다 입자 SIZE를 측정했으며, DNA와 CHROMA METERS를 사용하여 CELLULAR RENEWAL을 측정하였다.

• 한국식품과학회지
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• 제40권1호
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• pp.115-117
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• 2008

리포솜은 인지질로 구성된 인위적 세포막으로서, 본 연구에서는 초음파와 압력을 이용하여 나노 리포솜을 제조하였다. 먼저 리포솜을 탈수/재수화법으로 제조하였다. 형성된 multilayer vesilces(MLV)의 크기는 $10{\mu}m$ 이상이었다. Tip-type의 초음파 처리기와 French press를 이용하여 리포솜의 크기를 감소시켰다. MLV에 대한 출력 112.5W, 10분간의 초음파 처리로 리포솜의 크기가 450 nm 이하로 감소되었다. 또한, 6,000 psi 이상의 압력에서는 100 nm 내외의 균일한 리포솜이 생성되었다. 초음파와 가압에 의한 리포솜 용액의 색도는 대체로 명도, 적색도, 황색도가증가하였으며, 육안으로는 점점 더 투명하게 되었다. 이러한 결과는 초음파와 French press를 이용한 가압 처리로 나노 크기의 리포솜을 얻을 수 있음을 의미한다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2009년도 춘계학술대회 논문집
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• pp.344-347
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• 2009

Surge protective devices (SPD) have a special position because of the expectation that they perform an effective protective function against various kinds of surges. However, there exists a misconception that the SPD satisfying lower measured limiting voltage (MLV) should also protect equipment against temporary overvoltages (TOVs) as well. This paper inspects various types of MOV based SPDs and carry out experiments on the side effects of the low MLV characteristics. The experiment results show that a low MLV could cause a higher TOV-induced SPD failure rate in the field.