• Journal of Dairy Science and Biotechnology
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• 제35권3호
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• pp.208-214
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• 2017

본 연구에서는 산양유 단백질 분해물과 키토올리고당을 이용하여 약 138~225 nm 크기를 지니는 구형의 나노 전달체를 성공적으로 제조하였다. 제조된 나노 전달체는 소수성 건강기능성 물질인 DHA와 레스베라트롤을 각각 ~22 mg/100 mL와 ~4.5 mg/100 mL 씩 포집가능하며, 제조 공정요인(예, TPP 농도, 산양유 단백질 분해물 농도, 키토올리고당 농도) 조절을 통해 입자 크기, 표면전하등과 같은 나노 전달체의 물리화학적 특성과 소수성 건강기능성 물질의 포집 효율을 조절할 수 있음을 알 수 있었다. 또한 산양유 단백질 분해물/키토올리고당 나노 전달체는 동결건조를 통해 분말화가 가능하기 때문에 식품 적용성이 뛰어나다. 결론적으로 본 연구에서 food-grade 물질인 산양유 단백질 분해물과 키토올리고당을 이용하여 제조한 나노 전달체는 저지방 및 무지방 유식품에 적용 가능한 무지방 기반(non-fat based)의 소수성 건강기능성 물질 전달체로 이용될 수 있을 것으로 기대된다.

• 한국산학기술학회논문지
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• 제19권4호
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• pp.1-7
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• 2018

화석연료를 사용하는 내연기관에서 배출되는 가스는 환경오염, 지구온난화와 인체에 유해하여 많은 사회적인 문제를 야기시키고 있다. 최근에는 신재생에너지의 수요가 증가하고 있으며, 정부의 정책적인 지원과 연구개발 또한 활발하다. 가정에서 많이 사용되는 태양열에너지 시스템의 집열부는 열매체로 프로필렌글리콜 부동액이 물과 50% 고정된 값으로 혼합되어 영하온도에서도 집열부에 열을 전달한다. 그러나 집열부 내의 열매체에 누수가 발생되면 태양열시스템 특성상 보충수를 태양열 집열부에 공급하는데, 이로 인하여 보충수 내의 급수로 인하여 부동액 농도가 낮아지게 된다. 이에 따라 태양열 집열부위의 온도가 저하되어 동파를 야기하게 되는데 태양열에너지 시스템 정비 보수를 위해서 비용 부담이 증가하여 많은 문제점을 증가시킨다. 이 연구는 태양열에너지 시스템에 발생되는 동파 방지를 위하여 온도 저하에 따라 자동으로 부동액 농도를 제어가능한 장치를 개발하는 것이다. 물 성분이 프로필렌글리콜보다 전기전도도가 크며, 온도가 저온으로 내려갈수록 저항값이 증가하였다. 프로필렌글리콜 농도 제어 목표값 40, 50 및 60% 값은 39.6, 50.7 및 60.1%의 프로필렌글리콜 농도값으로 보정을 통하여 제어를 해야 한다.

• Fisheries and Aquatic Sciences
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• 제5권2호
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• pp.87-96
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• 2002

The physico-chemical properties of fresh milt of marbled sole, Limanda yokohamae, brown sole, Limanda herzensteini, starry flounder, Platichthys stellatus and olive flounder, Paralichthys olivaceus among flatfishes, and the fine structure of their cryopresserved spermatozoa were investigated. The highest concentration of sperm among these four species was $3.60\pm1.35\times10^{10}/mL$ in marbled sole. Osmolality and pH of seminal plasma in four flatfish species were approximately 330 mOsm/kg and 7.6-8.1, respectively. Seminal plasma compositions showed interspecific differences. The sperm heads of marbled sole, brown sole and starry flounder were ellipsoidal and that of olive flounder was round. The numbers of mitochondria of these four species were eight in marbled sole, seven in brown sole and starry flounder, and six in olive flounder. Cross-sectional view of flagellum showed typical 9+ 2 structure in all species. Most of sperms cryopreserved with a proper method had no visible ultrastructural changes after freeze-thawing, compared with the fresh sperm, but in a few cases, swelling of their heads and midpiece regions were observed.

• Food Science and Biotechnology
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• 제17권1호
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• pp.46-51
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• 2008

The objective of this study was to investigate antioxidant activities of freeze-dried, main root, and fine root of ginseng (Panax ginseng CA. Meyer), which were extracted with various solvents including ethanol, methanol, and water. Ethanol extracts in both parts showed the most powerful scavenging activities against DPPH radicals. Especially, ethanol extract of fine root had higher reducing power and antioxidant capacity than that of main root. The highest antioxidant activity in linoleic acid emulsion system was also observed in fine root extracted with ethanol, followed by methanol and water. Both ferrous ion chelating activity and ferric reducing antioxidant power (FRAP) of extracts were increased with the increase of extracts concentration. These results suggest that ethanol extract of fine root of ginseng has the most effective antioxidant capacity compared to the methanol and water extracts tested in the present study. Thus it can be applied for the effective extraction of functional material from ginseng for the usage of pharmaceutical and/or food industries.

• 한국결정성장학회지
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• 제1권1호
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• pp.17-25
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• 1991

The construction details of VGF apparatus with a DM(direct monitoring) furnace for the growth of low defect crystal and characteristics of GaAs crystal grown by this apparatus are described. The average dislocation densities and EL2 concentration of as-grown undoped GaAs along the different solidified fractions exhibit $4{\times}10^{2}-7{\times}10^{3}cm^{-2}$ and $6{\times}10^{14}-4{\times}10^{15}cm^{-3}$, which are less than those observed for liquid encapsulated Czochralski(LEC) or high-pressure vertical gradient freeze(VGF) crystals. These remarkable reduction of the dislocation densities and EL2 concentrations were explained by the lower temperature gradient ($dT/dx-10^{\circ}/cm$) and slower rates of post - growth cooling ($20^{\circ}C/hr:1240-1000^{\circ}C,\;30^{\circ}C/hr:1000-700^{\circ}C$). Also, The Hall mobilities, carrier concentrations show uniform distribution throughtout 80% of the ingot length.

• 한국환경보건학회지
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• 제17권2호
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• pp.102-113
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• 1991

This study aimed to find out the effect of freeze-drying leek against cadmium poisoning on the cholesterol and enzyme activities in serum and superoxide radical, SOD and catalase in liver and kidney of the male rats during the administrered period. In this experiment, male rats of Sprague-Dawley strain were used. The rats were divided into 3 groups which were fed differently either for 5 weeks or for 10 weeks:basal diet, basal diet and cadmium in water and 3 % leek added diet and cadmium in water. Cadmium was administered ad libiturn 100 ppm CdCl$_{2}$ in water. The followings are the results of this experiment. 1. Leek reduced the cholesterol and the activities of GPT increase resulted from cadmium treatment. 2. Leek reduced the rate of cadmium in liver and kidney. 3. Leek reduced the activities of SOR and catalase in liver and kidney, while it enhanced the activities of SOD. 4. Leek reduced the necrosis and swelling in liver and kidney casused by cadmium treatment. This experiment showed that leek-addition group had protective effect against cadmium poisoning and increased ALPase activities in serum. Leek alleviated GPT activities in serum and cadmium concentration, necrosis, and swelling in liver and kidney. Therefore, this experiment concluded that leek has defensive power against cadmium poisoning.

• 박물관보존과학
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• 제5권
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• pp.37-41
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• 2004

광주신창동 저습지유적에서 출토된 수침고목재 유물은 재질이 매우 취약하여, 공기 중에 노출되면 건조가 진행되어 곧바로 수축·변형이 일어나게 되므로 전시 및 보존을 위해서는 특별한 보존처리가 필요하다. 특히 칠기칼집과 같이 목재표면에 치밀하게 옻칠이 되어있어 칠기는 처리약제가 잘 침투되지 않고 처리 중 칠막이 부풀거나 탈락될 우려가 높아 보존처리가 매우 까다롭다. 칠기칼집은 낮은 농도의 PEG#4000 40% 수용액(水溶液)에 함침처리 후 동결건조하는 방법을 적용하여 보존처리 하였다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 추계학술발표대회
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• pp.14-14
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• 2011

AlInN has been studied extensively over the past few years due to its interesting material properties that are not present in other ternary nitrides. However, basic material study of AlInN has not been reported as much compared to device applications due to the difficulty in the growth. We have performed the material studies from various aspects. A secondary ion mass spectrometry (SIMS) has shown high oxygen content above $1{\times}10^{18}\;cm^{-3}$ with its insensitivity to the growth conditions. While the free carrier concentration observed by the capacitance-voltage (C-V) measurements was about $3{\times}10^{17}\;cm^{-3}$, the activation energy measured by temperature dependent C-V was only about 4 meV. Si doped AlInN (Si level ${\sim}2{\times}10^{18}\;cm^{-3}$) showed almost no carrier freeze-out at carrier density of $1{\times}10^{18}\;cm^{-3}$. More studies were carried out with a transmission electron microscopy, time-resolved photoluminescence and other analytical techniques to understand the results from SIMS and C-V studies. In this report, we will discuss the possible correlations between the abnormal characteristics in AlInN.

• Macromolecular Research
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• 제11권6호
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• pp.488-494
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• 2003

We have fabricated gelatin-immobilized polyurethane foams (PUFG) by dipping polyurethane foam (PUF) in an aqueous solution containing gelatin and by subsequent reaction with glutaraldehyde after freeze-drying. Gelatin aqueous solutions of different concentrations were used as the dipping solutions to control the amount of immobilized gelatin. The average pore size of PUF decreased with an increase in gelatin concentration. It was found from the hepatocyte adhesion experiment that the amount of hepatocytes seeded on PUFG1, prepared by using a 1% aqueous gelatin solution, was higher than that on other PUFGs. The hepatocytes inoculated in PUFG1, were slightly aggregated as the incubation time increased. The cells inoculated in PUFG1 showed higher ammonia removal ability than those monolayer-cultured on a gelatin-immobilized polystyrene dish (PSG) after 1 and 4 days of incubation time. The inoculated cells exhibited higher albumin secretion relative to monolayer-cultured hepatocytes on PSG. Albumin secretion by hepatocytes seeded on PUFG1 was increased by the presence of serum and was further increased by both the presence of serum and cytokines. The results obtained from a 3-(3,4-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that PUFG can provide a better microenvironment for hepatocyte culture along with nutrition and metabolite transfer through the high porosity of PUF.

• Journal of Pharmaceutical Investigation
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• 제33권3호
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• pp.209-213
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• 2003

The objective of this study was to construct the pegylated liposomes containing plasmid DNA with optimal encapsulation efficiency. Plasmid DNA $(pGL2\;clone\;753,\;{\sim}6\;kb)$ was encapsulated by the freeze/thawing method into liposomes composed of 1-palmitoyl-2-oleyl-sn-glycerol-3-phosphocholine (POPC), didodecyl dimethyl ammonium bromide (DDAB), distearoylphosphatidyl ethanolamine polyethylene glycol 2000 (DSPE-PEG 2000) and DSPE-PEG 2000-male-imide. The liposomes containing plasmid DNA were then extruded through two stacked polycarbonate filters with series of different pore sizes to control the liposome size. The plasmid DNA entrapped in the liposomes was separated from free plasmid DNA by Sephadex CL-4B column chromatography. The decreased pore size of polycarbonate filters resulted in the decreased size of liposomes. The encapsulation efficiency was markedly affected by the cationic lipid (DDAB) concentration, but to a low degree by the size of liposomes and by the amount of plasmid DNA.