• Title/Summary/Keyword: MLV

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A study on manufacturing formation of the MLV liposomes by the microfludizer (마이크로플루다이저를 사용한 MLV liposome 형성에 관한 연구)

  • 김인영;김중희
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.21 no.1
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    • pp.38-52
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    • 1995
  • The liposomes have been developed in many drugs and cosmetics fields. In this context, it should be mentioned that MLV liposomes can be prepared standing with the main compounds of the intercellular lipids, cholesterol, palmitic acid, cholesteryl ester and lecithin, by swelling reaction. We report properties of the formation of MLV liposomes with use of the lipid base and Microfluidizer. MLV liposomes formed as multilamellar vesicles(MLV). The effect of the gelation of MLV liposomes have been on swelling reaction which have been mixed lipid with polyol and water phase at high temperature(90$\pm$5$^{\circ}C$). MLV liposomes have been prepared in incorporating alpha hydroxy acid ligrediens. Optimum condition of MLV liposomes were passed three times in the microfluidizer, particle size of the vesicles should be within 150-350nm and those confirmed by freeze-fracture electron microscopy.

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In Vivo Evaluation of Multi Lamellar Vesicle Liposome’s Percutaneous Absorption and Stability

  • Joung, Min-Seok;Park, Jong-Oan;Seo, Bong-Seok;Ryu, Chang-Duck
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.27 no.1
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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.

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Protection provided by a commercial modified-live porcine reproductive and respiratory syndrome virus (PRRSV) 1 vaccine (PRRSV1-MLV) against a Japanese PRRSV2 field strain

  • Joel Miranda;Salvador Romero;Lidia de Lucas;Fumitoshi Saito;Mar Fenech;Ivan Diaz
    • Journal of Veterinary Science
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    • v.24 no.5
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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.

Stability and Formation Mechanism for MLV liposomes with Phospholipid Film by Use of the Microfluidizer

  • Kim, In-Young;Seo, Bong-Seok
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.22 no.2
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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.

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STUDY ON THE STABILITY OF O/W AND MLV EMULSION CONTAINING DIHYDROXYACETONE

  • Joo, Yong-Joon;Han, Yeoung-Jun;Joo, Yong-Ho;Jeon, Young-Hwan
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.24 no.3
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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.

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Role of a Third Extracellular Domain of an Ecotropic Receptor in Moloney Murine Leukemia Virus Infection

  • Bae Eun-Hye;Park Sung-Han;Jung Yong-Tae
    • Journal of Microbiology
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    • v.44 no.4
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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.

Experimental Study on Temporary Overvoltage Characteristics of MOV Based Surge Protective Devices (MOV 기반 서지보호기의 일시과전압 특성에 대한 실험적 연구)

  • Shim, Hae-Sup;Jeon, Tae-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.24 no.1
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    • pp.71-77
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    • 2010
  • Protection against lightning surge is an essential part of almost any electrical and electronic equipment today. Metal Oxide Varistor(MOV) is the single most important component in the overwhelming majority of the Surge Protective Devices(SPD) designated to provide such protection. In this paperr various types of MOV based SPD are inspected and experiments are carried out on the side effects of the low Measured Limiting Voltage(MLV) characteristics. Experiment results show that a lower MLV could cause a higher Temporary Overvoltage(TOV)-induced SPD failure rate in the field, and SPD are more likely to be victims rather than protectors in a TOV scenario. This means that from a safety perspective, the SPD should be specified with higher TOV withstand capability(UT) and faster SPD disconnector.

The effect and stability of Retinyl Palmitate(RP) in W/O, W/S, O/W, MLV(Multilamellar Vesicles) cream (W/O, W/S, O/W, MLV(Multilamellar Vesicles) TYPE에서 Retinyl Palmitate(RP)의 열적 안정성과 효능, 효과에 관한 연구)

  • 지홍근;서봉석
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.22 no.1
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    • pp.40-59
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    • 1996
  • Retinyl Palmitate, the skin normalzer, is useful to promote greater skin elasticity, to diminish lipid peroxidation and skin roughness following UV exposure, and promote a youthfull general skin appearance. We knew that the reduction of retinyl palmitate in W/O, W/S, O/W, MLV cream was caused by variable compound factors. Among the retinoids, we chose retinyl palmitate and studied the stability behavior of retinyl palmitate is liposomed. Furthermore, HPLC, CHROMA METERS, LASER SIGHT SCATTERING SYSTEM and FREEZE FRACTURE SCANNING ELECTROM MICROSCOPY was used to analyzing the stability and efficacy of UV and heat.

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Preparation of Nano-liposome by Sonication and Pressure (초음파와 압력을 이용한 나노 리포솜의 제조)

  • Lee, Jung-Min;Cho, Yong-Jin;Park, Dong-Joon;Ko, Sung-Ho;Lee, Seung-Cheol
    • Korean Journal of Food Science and Technology
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    • v.40 no.1
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    • pp.115-117
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    • 2008
  • Liposomes are artificial membranes prepared by phospholipid. In this study, liposomes were prepared by dehydration-rehydration method, and then nano-sized by sonication and pressure. The sizes of the prepared multilamellar vesicles (MLV) were greater than 10 μm. Sonication with a tip-type sonifier or pressurization with a French press on MLV were carried out to reduce size. Sonication with an output of 112.5 W for 10 min on MLV resulted in sizes less than 450 nm. French press with 6,000 psi of pressure was able to manufacture liposomes of approximately 100 nm uniformly. Also, the sonication or pressure clarified the color of the liposome solutions. The results indicate that sonication and pressure via French press can be applied to obtain nano-sized liposomes.

Experimental Study on Temporary Overvoltage Characteristic of Surge Protective Devices (서지보호기의 일시과전압특성에 대한 실험적 연구)

  • Shim, Hae-Sup;Jeon, Tae-Hyun
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2009.05a
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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.

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