• 한국임상수의학회지
• /
• 제14권2호
• /
• pp.230-234
• /
• 1997

In vitro effect of cortisol on the proliferation of canine peripheral blood mononuclear cells (MNC) was examined. The MNC was isolated from peripheral blood by a gradient centrifugation with Picoll-Hypaque. The cell proliferation assayed using a noneradioactive 5-Bromo-2'-deoxy-uridine (BrdU) kit. The MNC proliferated well in response to either phrtobeRagg$]$utinin-p (PHA-P) or culture supernatant from MNC stimulated with PHA-p. However, these proliferative responses of MNC were not affected by addition of coitisol of 1 to 1,OOfl ng/ml. The addition of cortisol in MNC culture with either PHA-P or corture supernatBnt from MNC stimulated with PHA-P far 4 days wag not also influenced on the viabilities of cultured MNC. In conclusions it was able to assay the cell proliferation with BrdU instead of radioactive isotope e.g. tritiated thymidine (3H-TdR). These results suggested that cortisol does not at least influence on MNC proliferation in vitro.

• Bulletin of the Korean Chemical Society
• /
• 제24권7호
• /
• pp.957-960
• /
• 2003

A method of preparation of magnetite nanoparticles in ordered systems, as in vesicle and microemulsion, consisting of soybean lecithin and water has been introduced. The size of magnetite grain was controlled by the content of soybean lecithin and size of liposomes in the systems. It was found by experiment that magnetite nanoparticles were formed inside the double layer vesicles. The magnetite nanoparticles were separated by magnetic separation and centrifugation and the dispersion of the magnetite nanoparticles prepared at 10% (w/w) soybean lecithin was particularly stable. The formation of pure magnetite nanoparticles was confirmed by analyses of XRD and electron diffraction pattern.

• 대한기계학회논문집A
• /
• 제31권4호
• /
• pp.483-489
• /
• 2007

We have investigated quantitative measurement techniques of the degree of dispersion of single-walled carbon nanotubes (SWNTs). SWNTs were suspended in aqueous media using a sodium dodecyl sulfate (SDS) surfactant. SWNTs with different dispersion states were prepared by controlling the intensity and time of sonication and centrifugation. The laser spectroscopic techniques were employed to characterize the dispersion state; i.e., raman fluorescence and absorption spectroscopic techniques. Raman spectroscopy has been used to probe the dispersion and aggregation state of SWNTs in solution. Individually suspended SWNTs show increased fluorescence peaks and decreased roping peaks at a raman shift 267 $cm^{-1}$ compared with the samples containing bundles of SWNTs. The ultraviolet-visible-near infrared (UV-vis-NIR) absorption spectrum of decanted supernatant samples show sharp van Hove singularity peaks

• KSBB Journal
• /
• 제18권1호
• /
• pp.35-38
• /
• 2003

양수 내에 존재하는 총 단백질을 이차원 전기영동을 이용하여 분리 분석하였고, gradient gel을 이용하여 양수 내에 소량으로 존재하는 미세 단백질까지 분리하였다. 양수 내에는 고농도로 존재하는 단백질이 있는데 이것이 serum albumin precursor임을 확인하였고, 8-18% gradient gel의 이용으로 분해능(resolution)이 향상되어 미세 단백질을 분리 분석할 수 있었다. 이차원 전기영동 후 MALDI-TOF를 이용하여 단백질을 identification하여 기존의 양수 protein database에 존재하는 단백질을 확인하였고, 존재하지 않는 새로운 단백질을 분리 분석하였다.

• 한국식품영양과학회지
• /
• 제22권6호
• /
• pp.771-776
• /
• 1993

Aqueous extraction of sea tangle at the temperature range of 60~10$0^{\circ}C$ was studied for temperature effects on soluble solids and protein yields, amino nitrogen, turbidity and viscosity of extracts. The solids and protein yield were increased as the temperature increased and most of solids and protein were extracted during 1 hour. The supernatant ratio after centrifugation showed significantly low for the extraction at 6$0^{\circ}C$. More temperature effects were found on turbidity and viscosity than yields. A significantly higher total amino nitrogen contents was obtained from higher temperature at initial stage of extraction and then the differences of them became to be narrow as the extraction prolonged further. The low values of 24.1% solids and 13.5% protein yields after 2 hours of extraction at 10$0^{\circ}C$ indicated that most of solids in sea tangle are insouble.

• 미생물학회지
• /
• 제15권1호
• /
• pp.46-59
• /
• 1977

To screen biologically active components of the higher fungi of Korea, the carpophores of Auricularia polytricha, a well-known edible mushroom, were extracted with 0.14M NaCl solution. The extractive was successively fractionated by adding ammonium sulfate in various amounts, the respective precipitates being weparated by centrifugation, dialyzed and freeze-dried. When a dose of 60mg/kg of each was, i.p., injected into ICR mice, the fraction shich was precopitated at 20% (NH$_{4}$)$_{2}$SO$_{4}$ showed the highest toxicity, killing seven mice within two days. The fraction obtained at 40% (NH$_{4}$)$_{2}$SO$_{4}$ showed the second highest toxicity. The two fractions were named auratoxin I and II after the genus name. The symptoms of the intoxication were convulsion during the first 30 minutes after the injection, then sleeping within an hour, and tremor, lacrimation, nasal and ophthalmic bleeding, congestion and death in 24 hours. Particularly the spleen of the mice was fonud to be enlarged remarkably. The chemical analysis of the toxins showed that auratoxin I consisted of 4.4% protein and 84.5% polysaccharide and that auratoxin II 35.8% protein and 48.0% polysaccharide.

• 미생물학회지
• /
• 제25권4호
• /
• pp.255-261
• /
• 1987

Five independent Actinomycetes harboring plasmids were isolated from soil. Molecular weight of these plasmids was 55kb, 6.2kb, 4.4kb, 55kb and 7.0kb, respectively. Among them small and apprent high copy number plasmids, pJY501 of 4.4kb and pHY711 of 7.0kb, were selected. The plasmids purified by CsCl-EtBr density gradient centrifugation preserved the conformation of supercoiled covalently closed circular molecule, and an apparent copy number was estivated about 150 and about 35 per chromosome. The isolates carrying plasmids were assigned to the genus Streptomyces. For the purpose of introducing selection markers into the isolated plasmids, the tsr fragmemt of pIJ702 was inserted into the BclI site of pJY 501 and pJY711. And the recombinant plasmids constructed designated as pJY502 and pJY712 respectively.

• 미생물학회지
• /
• 제22권4호
• /
• pp.223-228
• /
• 1984

To screen biologically active components of the higher fungi of Korea, the carpophores of Auricularia polytricha, a well-known edible mushroom, were extracted with 0.14M NaCl solution. The extractive was successively fractionated by adding ammonium sulfate in various amounts, the respective precipitates being weparated by centrifugation, dialyzed and freeze-dried. When a dose of 60mg/kg of each was, i.p., injected into ICR mice, the fraction shich was precopitated at 20% (NH/sub 4/)/sub 2/SO/sub 4/ showed the highest toxicity, killing seven mice within two days. The fraction obtained at 40% (NH/sub 4/)/sub 2/SO/sub 4/ showed the second highest toxicity. The two fractions were named auratoxin I and II after the genus name. The symptoms of the intoxication were convulsion during the first 30 minutes after the injection, then sleeping within an hour, and tremor, lacrimation, nasal and ophthalmic bleeding, congestion and death in 24 hours. Particularly the spleen of the mice was fonud to be enlarged remarkably. The chemical analysis of the toxins showed that auratoxin I consisted of 4.4% protein and 84.5% polysaccharide and that auratoxin II 35.8% protein and 48.0% polysaccharide.

• 한국식품영양학회지
• /
• 제6권4호
• /
• pp.281-286
• /
• 1993

Strawberry pulp was separated into serum and Insoluble pulp by centrifugation. The serum was concentrated in vacuo at 55~58$^{\circ}C$ and 10% aroma recovered. Two folds concentrated strawberry pulp was prepared by mixing concentrated serum, aroma fraction and Insoluble pulp. To develop aroma-rich jam, the strawberry jam was prepared by filling mixture of concentrated pulp, sucrose, citric acid and pectin into retortable pouches and by heating them after heat-seating. The color and flavor quality of the jam prepared by new method were better than the jam prepared by conventional method, as Indicated by GC, GC/MS data, surface color and anthocyanin contents. These results were confirmed by the sensory evaluations. Flavor off-flavor, color intensity and overall acceptance were superior to the conventional method.

• Preventive Nutrition and Food Science
• /
• 제5권2호
• /
• pp.81-85
• /
• 2000

Bromelain has been used as a meat-tenderizing agent in food processing. To increase the availability of bromelain, microencapsulation into liposome was carried out by the dehydration and rehydration method. Small unilamellar vesicles prepared by sonication treatment showed higher encapsulation efficiency (EE) than by the French press method. In the preparation of liposome, the effect of pH and centrifugal force on EE was also investigated and it showed a higher EE at acidic pH than at alkaline pH with centrifugation at 80, 000$\times$g. The actual EEs except unencapsulated bromelain which bound on the outside surface of liposome by electrostatic interaction also were investigated, and the optimal EE was at pH 4.6, at 0.6 of a ratio of bromelain to phosholipid(18.2%, w/w). Release of bromelain from liposomes was stimulated as the temperature increased at neutral pH.