• The Korean Journal of Food And Nutrition
• /
• v.8 no.2
• /
• pp.88-92
• /
• 1995

The antioxidant activity of synthetic antioxidants, BHA, BHT and TBHQ and natural antioxidants, rosemary extract, sesamol, caffeic acid and pyrogallol In a skip jack oil were studied. A control and substrates containing synthetic(0.02%) and natural antioxidant (0.05%) were stored in an incubator kept at 37$^{\circ}C$ for 8 days. The antioxidant activity of synthetic and natural antioxidants was investigated by comparing peroxide values. The results of this study were as follows All the synthetic antioxidants used for this study exhibited antioxidant activity in skip jack oils. The antioxidant activity of TBHQ was greater than that of BHA and BHT. The rosemary extract did not show antioxidant activity in skip jack oils. The antioxidant activity of sesamol and caffeic acid were greater than those of BHA. Especially Pyrogallol exhibited very strong antioxidant activity, comparable to that of the TBHQ. The antioxidant activity of the sesamol, caffein acid and pyrogallol used skip lack oil, In decreasing order as follows : pyrogallol>caffeic acid> sesamol.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.12
• /
• pp.4169-4172
• /
• 2012

To elucidate the roles of cysteine residues in rice Phi-class GST F3, in this study, all three cysteine residues were replaced with alanine by site-directed mutagenesis in order to obtain mutants C22A, C73A and C77A. Three mutant enzymes were expressed in Escherichia coli and purified to electrophoretic homogeneity by affinity chromatography on immobilized GSH. The substitutions of Cys73 and Cys77 residues in OsGSTF3 with alanine did not affect the glutathione conjugation activities, showing non-essentiality of these residues. On the other hand, the substitution of Cys22 residue with alanine resulted in approximately a 60% loss of specific activity toward ethacrynic acid. Moreover, the ${K_m}^{CDNB}$ value of the mutant C22A was approximately 2.2 fold larger than that of the wild type. From these results, the evolutionally conserved cysteine 22 residue seems to participate rather in the structural stability of the active site in OsGSTF3 by stabilizing the electrophilic substrates-binding site's conformation than in the substrate binding directly.

• Plant Resources
• /
• v.3 no.3
• /
• pp.226-232
• /
• 2000

The availability of enokitake cultural waste for Lentinus edodes cultivation was investigated, although hardwood sawdust has traditionally been used as a substrate for this fungus. Firstly, physiochemical characteristics of cultural waste were analysed. Secondly, mycelial growth characteristics and fruiting yields of L. edodes on waste treated in some methods were determined. Physiochemical characteristics of enokitake cultural waste showed that the millwaste complex was a little degraded by enokitake fungus and suggested the probability that most component lost by enokitake could be rice bran. Mycelia of L. edodes grew and fruited well on waste supplemented by fresh rice bran and Quercus sawdust although didn't on waste only. Mycelial growths of these fungi on waste were accelerated when supplemented by rice bran to the percent of 40(w/w) but decreased or suppressed at above ratios(30, 40%, w/w). Supplementations of oak sawdust at above 40%(w/w) of the waste and rice bran at 20%(w/w) of the sawdust allowed such a good mycelial growth as to be selected as a pertinent mixing ratio for fruiting medium. A fruiting yield on enokitake cultural waste supplemented by oak sawdust (at 40% of the waste, w/w) and rice bran (at 20% of the sawdust, w/w) was not inferior to that on oak sawdust supplemented by rice bran only (at 20% of the sawdust, w/w). These results indicated strongly the potentiality of enokitake cultural waste as raw materials for shiitake cultivating substrates.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.1
• /
• pp.25-32
• /
• 2007

We investigated the silicide reaction stability between 10 nm-Col-xNix alloy films and silicon substrates with the existence of 4 nm-thick natural oxide layers. We thermally evaporated 10 nm-Col-xNix alloy films by varying $x=0.1{\sim}0.9$ on naturally oxidized single crystal and 70 nm-thick polycrystalline silicon substrates. The films structures were annealed by rapid thermal annealing (RTA) from $600^{\circ}C$ to $1100^{\circ}C$ for 40 seconds with the purpose of silicidation. After the removal of residual metallic residue with sulfuric acid, the sheet resistance, microstructure, composition, and surface roughness were investigated using a four-point probe, a field emission scanning electron microscope, a field ion bean4 an X-ray diffractometer, and an Auger electron depth profiling spectroscope, respectively, to confirm the silicide reaction. The residual stress of silicon substrate was also analyzed using a micro-Raman spectrometer We report that the silicide reaction does not occur if natural oxides are present. Metallic oxide residues may be present on a polysilicon substrate at high silicidation temperatures. Huge residual stress is possible on a single crystal silicon substrate at high temperature, and these may result in micro-pinholes. Our results imply that the natural oxide layer removal process is of importance to ensure the successful completion of the silicide process with CoNi alloy films.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.23 no.6
• /
• pp.788-799
• /
• 1999

This study was performed to investigate the effect of mordants on the dyeability colorfastness to light and to laundering and biological properties of mordanted and natural-dyed cotton and silk substrates. Natural red dyes were extracted from Caesalpinia Sappan L. (Sappan wood) and Rubia Akane Nakai (Madder) by boil water Five different compounds of Al, Cr, Cu, Fe and Sn were used as mordanting agents. The result of this study are sumarized as follows ; 1. In the of the fabrics mordanted and dyed with sappan wood K/S value increases and λmax shifts to the longer wavelength as mordant concentration increases. Color of the fabrics dyed with sappan wood and madder change to redder bluer and lighter after mordanting. 2. As the number of repetition of dyeing-mordnating process increase the color of the dyed fabrics tend to be redder bluer and darker. Mordanted dyes with Al and Sn make chroma increase. The quantity of mordant absorbed in the silk fabric increase as mordant concentration increase. More Fe is absorbed in silk than Cr is. 3. After being exposed to light the fabrics dyed with sappan wood and madder change to less red Fe and Cu mordanting yeild better colorfastness to light than others does. Natural-dyed fabrics exposed to light tend to be faded and whitened in CIELAB chromaticity co-ordinates. So we might trace back the original color of ancient faded fabrics by changes in color of natural dyes. 4. After washing the colors of natural dyes change to more blue, Fe and Cu mordanting give better colorfastness to wash than others do. 5. The soil-burial cotton is more susceptible to mildew and rot than the silk is. Antimicrobial activity of the natural-dyed cotton can be enhanced by Cu and silk can be enhanced by Cu and Cr mordanting respectively.

• Animal cells and systems
• /
• v.3 no.2
• /
• pp.167-172
• /
• 1999

We report for the first time the life history of a 'social' spider, Philoponella prominens, living in a temperate region. Philoponella prominens hibernated as immatures or subadults for 7-8 months in 1995 and 1996 from September-October to April-May in central Korea. When they emerged from their winter hibernation, a majority began their lives as commensals in the webs of other species. As the mating season approached, however, commensal spiders switched to become colonial or solitary. The mating season began in early June and lasted until early August. Newly-hatched spiderlings began to appear in the field in late June. They formed a colony by building their webs connected to the mother's by using pan of the mother's web as supporting substrates. As the season progressed, however, some of the colonial spiderlings became commensal or solitary individuals. Our field observations suggest that Philoponella prominens form colonies or commensal associations to reduce the web-building cost.

• Transactions on Electrical and Electronic Materials
• /
• v.1 no.1
• /
• pp.1-5
• /
• 2000

Diamond films have been achieved on Si(100) substrates using helicon plasma chemical vapor deposition(HPCVD), Gas mixtures with methane and hydrogen have been used. The growth characteristics were investigated by means of X-ray photoelectroton spectroscopy, Atomic force microscopy and X-ray diffraction. We obtained a plasma density as high as 10$\^$10/~10$\^$11/ cm$\^$-3/ by helicon source. The smooth(100) faces of submicron diamond crystallites were found to exhibit pyramidal shaped architecture, The XPS spectrum for the nucleation layer indicates the presence of diamond at 285.4 eV, close to the reported value of 285.5 eV for diamond , XRD results demonstrates the existence of polycrystalline diamond as the diamond (111) and (220) peaks.

• Journal of Species Research
• /
• v.9 no.4
• /
• pp.473-479
• /
• 2020

In this study, we briefly describe five newly recorded foraminiferal species from off the southern coast of Jeju Island: Ammolagena clavata, Neoeponides bradyi, Nodosaria lamnulifera, Rhabdammina abyssorum, and Uvigerina schwageri. Ammolagena clavata and Rhabdammina abyssorum are the first reports of the genera Ammolagena and Rhabdammina in Korea. In addition, R. abyssorum is reported from a depth of 103 m, which is a relatively shallow record within the distribution depth range for this agglutinated deep-sea species. Ammolagena clavata also shows interesting characteristics that the test usually attaches to substrates including shell fragments, sediment particles, or other foraminiferal tests. All other three species have typical calcareous and hyaline tests. The present report on unrecorded species improves the understanding of foraminiferal species diversity in Korean waters and confirms the need for the further research on foraminifera in the adjacent seas of Korea.

• Journal of Integrative Natural Science
• /
• v.9 no.1
• /
• pp.41-61
• /
• 2016

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related mortality worldwide. Phosphoinositide 3-kinases (PI3Ks) play important role in Non-Small Cell Lung Cancer. PI3Ks constitute a lipid kinase family which modulates the function of numerous substrates involved in the regulation of cell survival, cell cycle progression and cellular growth. Herein, we describe the ligand based pharmacophore combined with molecular docking studies methods to identify new potent PI3K inhibitors. Several pharmacophore models were generated and validated by Guner-Henry scoring Method. The best models were utilized as 3D pharmacophore query to screen against ZINC database (Chemical and Natural) and the retrieved hits were further validated by fitness score, Lipinski's rule of five. Finally four compounds were found to have good potential and they may act as novel lead compounds for PI3K inhibitor designing.

• Journal of the Korean Chemical Society
• /
• v.43 no.1
• /
• pp.104-109
• /
• 1999

A number of leukocytes increases when infected by a germ or virus. Detection of leukocyte levels can indicate of such medical informations as urogenital tract infection or other dysfunction. In this study, pentyl-3-thiophene-carboxlyate (PTC), pentyl-8-quinolinecarboxylate (PQC), and 2-Phenyl-4(N-tosyl-alanyloxyl)-thiazole (PTT) were synthesized, and the test strips were prepared with these substrates for quantifying leukocytes in urine. Among these substrates, the PTT test strip prepared in 0.5% borate buffer pH 8.0, 0.03% PTT, 0.1-0.8% PVP, and 1% decanol showed not only better color reaction but also an excellent application possibility to be used in automatic urine analyzer.