• Title/Summary/Keyword: low melting

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In vitro Anticancer Activity of Paclitaxel Incorporated in Low-melting Solid Lipid Nanoparticles

  • Lee, Mi-Kyung;Yang, Jae-Heon
    • Journal of Pharmaceutical Investigation
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    • v.39 no.3
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    • pp.201-205
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    • 2009
  • Triglyceride solid lipid with medium chain fatty acid, tricaprin (TC), was used as a core matrix of lipid nanoparticles (LN) to solubilize water-insoluble paclitaxel and enhance the stability of nanoparticles by immobilization of incorporated drug in the solid core during storage at low temperature. In the present study, TC-LN containing paclitaxel was prepared by hot melt homogenization method using TC as a core lipid and phospholipids as stabilizers. The particle size of TC-LN containing paclitaxel was less than 200 nm and its zeta potential was around -40 mV. Calorimetric analysis showed TC core could be solidified by freezing and thawing in the manufacturing process in which the hot dispersion should be prepared at elevated temperature and subsequently cooled to obtain solid lipid nanoparticles. The melting transition of TC core was observed at $27.5^{\circ}C$, which was lower than melting point of TC bulk. The particle size of TC-LN remained unchanged when kept at $4^{\circ}C$. Paclitaxel containing TC-LN showed comparable anticancer activity to the Cremophore ELbased paclitaxel formulation against human ovarian (OVCAR-3) and breast (MCF-7) cancer cell lines. Thus, lipid nanoparticles with medium chain solid lipid may have a potential as alternative delivery system for parenteral administration of paclitaxel.

High Resolution Melting Analysis for Epidermal Growth Factor Receptor Mutations in Formalin-fixed Paraffin-embedded Tissue and Plasma Free DNA from Non-small Cell Lung Cancer Patients

  • Jing, Chang-Wen;Wang, Zhuo;Cao, Hai-Xia;Ma, Rong;Wu, Jian-Zhong
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.11
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    • pp.6619-6623
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    • 2013
  • Background:The aim of the research was to explore a cost effective, fast, easy to perform, and sensitive method for epidermal growth factor receptor (EGFR) mutation testing. Methods: High resolution melting analysis (HRM) was introduced to evaluate the efficacy of the analysis for dectecting EGFR mutations in exons 18 to 21 using formalin-fixed paraffin-embedded (FFPE) tissues and plasma free DNA from 120 patients. Results: The total EGFR mutation rate was 37.5% (45/120) detected by direct sequencing. There were 48 mutations in 120 FFPE tissues assessed by HRM. For plasma free DNA, the EGFR mutation rate was 25.8% (31/120). The sensitivity of HRM assays in FFPE samples was 100% by HRM. There was a low false-positive mutation rate but a high false-negative rate in plasma free DNA detected by HRM. Conclusions: Our results show that HRM analysis has the advantage of small tumor sample need. HRM applied with plasma free DNA showed a high false-negative rate but a low false-positive rate. Further research into appropriate methods and analysis needs to be performed before HRM for plasma free DNA could be accepted as an option in diagnostic or screening settings.

Volume Resistivity Characteristics of Low Density Polyethylene film irradiated with Electron Beam (전자선 조사된 저밀도 폴리에틸렌 박막의 체적고유저항 특성)

  • Cho, Don-Chan;Cho, Kyung-Soon;Lee, Soo-Won;Kim, Wang-Kon;Hong, Jin-Wooog
    • Proceedings of the KIEE Conference
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    • 1996.11a
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    • pp.193-195
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    • 1996
  • Low-density polyethylene(LDPE ; thickness 100[${\mu}m$] as a experimental specimen is irradiated with electron beam by using electron beam accelerator, and as an experimental specimen, the nonirradiated specimen and the specimen irradiated with electron beam is produced according to the classification of dose. From the analysis of DSC, the crystalline melting point of the specimen irradiated with electron beam is lower than that of virgin specimen. It is confirmed thai the volume resistivity is increased from the temperature over $50[^{\circ}C]{\sim}60[^{\circ}C]$ to the crystalline melting point because of the defects of solid structure and the formation of many trap centers by means of electron beam irradiation, but decreased in the temperature over the crystalline melting point because of the melt of crystalline.

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Optimized Thermoelectric Properties in Zn-doped Zintl Phase Magnesium-Antimonide

  • Rahman, Md. Mahmudur;Ur, Soon-Chul
    • Korean Journal of Materials Research
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    • v.32 no.6
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    • pp.287-292
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    • 2022
  • Magnesium-antimonide is a well-known zintl phase thermoelectric material with low band gap energy, earth-abundance and characteristic electron-crystal phonon-glass properties. The nominal composition Mg3.8-xZnxSb2 (0.00 ≤ x ≤ 0.02) was synthesized by controlled melting and subsequent vacuum hot pressing method. To investigate phase development and surface morphology during the process, X-ray diffraction (XRD) and scanning electron microscopy (SEM) were carried out. It should be noted that an additional 16 at. % Mg must be added to the system to compensate for Mg loss during the melting process. This study evaluated the thermoelectric properties of the material in terms of Seebeck coefficient, electrical conductivity and thermal conductivity from the low to high temperature regime. The results demonstrated that substituting Zn at Mg sites increased electrical conductivity without significantly affecting the Seebeck coefficient. The maximal dimensionless figure of merit achieved was 0.30 for x = 0.01 at 855 K which is 30% greater than the intrinsic value. Electronic flow properties were also evaluated and discussed to explain the carrier transport mechanism involved in the thermoelectric properties of this alloy system.

Manufacturing and Properties of Bi-Sn Impregnated Wood Composites of Juglans nigra (북미산 흑호두나무 Bi-Sn 용융합금 복합체의 제조와 특성)

  • Kang, Seog-Goo;Park, Kye-Shin;Lee, Ho;Seo, In-Soo;Lee, Jong-Shin;Lee, Hwa-Hyoung
    • Journal of the Korea Furniture Society
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    • v.22 no.1
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    • pp.54-62
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    • 2011
  • The metalized wood composites with natural grain of imported Juglans nigra, which was impregnated with low melting alloy were manufactured and evaluated in this study. And the proper manufacturing conditions was also investigated in this study. The low melting alloy with bismuth (Bi) and tin (Sn) which are harmless to humans, was applied to this new composites. The composites showed not only no defects of discoloration, delamination, swelling, and cracking, because of high dimensional stability and low thickness swelling, but also much improved performance such as high bending strength, high hardness, abrasion resistance, high thermal conductivity as floor materials. This study also suggested the proper impregnating condition, such as 10 minutes of the preliminary vacuum time, $186^{\circ}C$ of the heating temperature and 10 minutes of the maintaining pressure time at the pressure of $30kgf/cm^2$. This metalized wood composites showed 7 times higher density than control, great increase in bending strength from $131.8N/mm^2$ to $192.3N/mm^2$, and great increase in hardness from $18.2N/mm^2$ to $90.4N/mm^2$. The composites demonstrated not only high emissivity of 91%, high shilding effectiveness of 92.59∼99.99%, high fire resistance but also great decrease in abrasion depth, water absorption and thickness swelling.

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Development of Automatic Filling Process using Low-Melting Point Metal for Rapid Manufacturing with Machining Process (절삭가공과 저융점금속에 의한 쾌속제작용 자동충진공정 개발)

  • Shin, Bo-Seong;Yang, Dong-Yeol;Choi, Du-Seon;Kim, Ki-Don;Lee, Eung-Suk;Je, Tae-Jin;Hwang, Kyeong-Hyeon
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.3
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    • pp.88-94
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    • 2002
  • Recently, the life cycle and the lead-time of a product are to be shortened in order to satisfy consumer's demand. It is thus important to reduce the time and cost in manufacturing trial products. Several technique have been developed and successfully commercialized in the market of RPM(Rapid Prototyping and Manufacturing). However, most commercial systems currently use resins or waxes as the raw materials. So, the limited mechanical strength for functional testing is regarded as an obstacle towards broader application of rapid prototyping techniques. To overcome these problems, high-speed machining technology is being investigated worldwide for rapid manufacturing and even for direct rapid tooling application. In this paper, some fundamental experiments and analyses are carried out to obtain the filling time, materials, method, and process parameters for HisRP(High-Speed RP) process. HisRP is a new RP process that is combined high-speed machining with automatic filling. In filling process, Bi58-Sn alloy is chosen as filling material because of the properties of low-melting point, low coefficient of thermal expansion and no harm to environment. Also the use of filling wire it if advantage since it needs simple and flexible mechanism. Then the rapid product, for example a skull, is manufactured for aluminum material by HisRP process with an automatic set-up device thor 4-faces machining.

Thermal Behavior and Physical Properties of Low Density Polyethylene/Metallocene Linear Low Density Polyethylene Blends (저밀도 폴리에틸렌/메탈로센 선형 저밀도 폴리에틸렌 블렌드의 열적 거동 및 물성)

  • Kim, Jang-Yup;Hyun, Uk;Lee, Dong-Ho;Noh, Seok-Kyun;Lee, Sang-Won;Huh, Wan-Soo
    • Polymer(Korea)
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    • v.27 no.5
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    • pp.502-507
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    • 2003
  • The thermal and physical properties of low density polyethylene melt-blended with Metallocene linear low density polyethylenes were investigated. Since the Metallocene polyethylenes have similar MW and MWD except m-LLDPE4, it can be said that the thermal behavior and mechanical properties of the blends depend upon the l-octene comonomer content. The melting behavior of LDPE/m-LLDPE1 blends shows two melting peaks with LDPE contents higher than 50%, while the other blends show only one melting peak. It was observed that the blends show higher crystallization temperature and higher crystallinity with lower comonomer content. Initial modulus of a blend exhibited the behavior proportional to the crystallinity and the elongation at break of the blends was increased with increasing the m-LLDPE composition. Melt indices of the blends decreased with increasing the comonomer content of Metallocene LLDPE. Melt Index values of the blends show negative deviation.

Quality Characteristics of Grape Jellies with Sugar Derivative Sweeteners for the Elderly (대체당 첨가 고령자용 포도젤리의 품질 특성)

  • Lee, Mi-Hye;Choi, Eun-Jung;Oh, Myung-Suk
    • Journal of the Korean Society of Food Culture
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    • v.23 no.4
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    • pp.499-506
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    • 2008
  • This study was conducted to determine the quality characteristics of grape jellies for the elderly. The jellies contained sugar (control) or sugar derivative sweeteners (erythritol, isomaltooligosaccharide, sorbitol, and xylitol). Agar (0.31%) and $\kappa$-carrageenan (0.27%) were the gelling agents. The average age of the subjects participating in the acceptance test was 79. The lightness (L), redness (a), and yellowness (b) values of the agar gel with erythritol mostly decreased, indicating a darker and pale red color. The L and b values of the carrageenan gel with sugar derivative sweeteners increased, indicating brighter and yellowish color. The agar and carrageenan gels with sorbitol showed higher gelling and melting temperature, indicating that gelation occurred easily and did not easily melt. The agar and carrageenan gels with xylitol showed a low-melting temperature, indicating low stability with temperature change. The break-down rate of the agar and carrageenan gels with erythritol was low, whereas that of agar gel with sorbitol was relatively high despite its high melting temperature. Hardness, cohesiveness, gumminess, and chewiness of the gels with sugar derivative sweeteners decreased, and this tendency was most distinct with isomaltooligosaccharide in the agar gel and with sorbitol in the carrageenan gel. The rupture properties of the gel were the same as the hardness of the gel. Sensory acceptance of the agar gels with erythritol, sorbitol, isomaltooligosaccharide, and the carrageenan gel with erythritol was fairly high, whereas that of the agar gel with xylitol and the carrageenan gel with isomaltooligosaccharide and xylitol was low. The results show that sorbitol and erythritol are appropriate as sugar substitutes in grape jellies for the elderly about the acceptability and stability of the gels.

The MSW Pyrolysis & Melting Plant DONGBU R21 (생활폐기물 열분해용융시설 동부 R21)

  • Choi, Sang-Sim;Kim, Seok-Hwan;Kim, Kyong-Lae
    • 한국연소학회:학술대회논문집
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    • 2004.06a
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    • pp.314-328
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    • 2004
  • Mitsui Engineering and Shipbuilding Co., Ltd. (MES) has completed Recycling 21 (R21) pyrolysis and melting technology for municipal solid wastes. The basic technology is licensed from Siemens, but MES has made major improvements to the design and operation of the R21 system Consequently, up to now, MES has been completed six (6) R21 plants in Japan. The following text will provide a brief overview of the design & operating features of R21 technology, focused on the reliability of system and low emission of hazardous material, which have been proved by the successful construction & operation experience of the plants.

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Measurement Methods of Latent Heat for PCM with Low Melting Temperature in Closed Tube

  • Hong Hiki;Kang Chaedong;Peck Jong Hyeon
    • International Journal of Air-Conditioning and Refrigeration
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    • v.12 no.4
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    • pp.206-213
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    • 2004
  • Cycle test for developed phase change material (PCM) is necessary in order to assess the variation of latent heat, which decreases with time by deterioration. T-history method and measurement using heat-flux meter are appropriate for the cycle test in a tube filled with PCM because they do not need an extraction of sample in measuring heat of fusion. In the present study, these methods were applied to a PCM having a melting point below a room temperature, different to the past studies for PCMs melting above a room temperature. As a result of experiment using pure water as specimen, we can obtained rea-sonable values for heat of fusion.