• Journal of Practical Agriculture & Fisheries Research
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• v.25 no.3
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• pp.14-18
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• 2023

White leg shrimps cultured in an inland private aquaculture farm with low salinity waters showed abnormal swimming behavior and appetite reduction in July 2022. Then, gradual mortality was observed in the aquaculture farm. During the diagnosis, bacterial strain KNUAF-SHP3 was isolated from the hepatopancreas of the dead shrimps. Based on the sequence of 16S rRNA gene, KNUAF-SHP3 was proved to be Shewanella sp., clustering into a group with S. algae MARS 14 and S. chilikensis JC5T. According to the result of experimental infection test, all shrimps challenged with high concentrations, 2.1×108 CFU/ml and 2.1×109 CFU/ml showed apparent disease symptoms and the cumulative mortality rates reached 100% in 7 days post challenge. These results emphasized that Shewanella isolate in this study can be a potential pathogen of white leg shrimp cultured in low salinity water.

• IMMUNE NETWORK
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• v.14 no.2
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• pp.100-106
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• 2014

Infection with invasive Shigella species results in intestinal inflammation in humans but no symptoms in adult mice. To investigate why adult mice are resistant to invasive shigellae, 6~8-week-old mice were infected orally with S. flexneri 5a. Shigellae successfully colonized the small and large intestines. Mild cell death was seen but no inflammation. The infected bacteria were cleared 24 hours later. Microarray analysis of infected intestinal tissue showed that several genes that are involved with the sphingosine-1-phosphate (S1P) signaling pathway, a lipid mediator which mediates immune responses, were altered significantly. Shigella infection of a human intestinal cell line modulated host S1P-related genes to reduce S1P levels. In addition, co-administration of S1P with shigellae could induce inflammatory responses in the gut. Here we propose that Shigella species have evasion mechanisms that dampen host inflammatory responses by lowering host S1P levels in the gut of adult mice.

• Journal of Magnetics
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• v.4 no.2
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• pp.39-45
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• 1999

Sandwich structures of$ Nd_2Fe_{14}B/Fe/Nd_2Fe_{14}B $magnetic films have been grown by a KrF excimer laser (λ=248 nm) ablation technique. Magnetic properties were characterized by varying the thickness of hard ($Nd_2Fe_{14}B$) and soft (Fe) magnetic films and the volume fraction as well. In the (x)nm[NdFeB]/(y)nm[Fe]/(x)nm[NdFeB]/(100) Si structure the thickness (x) was varied from 3.6 to 54 nm, and (y) from 15 to 112 nm. At (y) = 15~20 nm where the volume fraction of Fe corresponded to 61~75%, the sandwich structure exhibited an enhanced Mr/Ms and iHc as well from the result of the exchange coupling between the magnetic layers. Experimentally calculated exchange constant$ (A_s) of A_s = 2.5{\times}10^{-10} J/m$ was estimated using the intrinsic coercivity (iHc) of 1.2 kOe at 5 K for the sandwich magnetic trilayers.

• Journal of the Korean Chemical Society
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• v.19 no.2
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• pp.142-146
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• 1975

The formation of iron oxide hydroxide in a ferrous sulfate was studied in different contents of iron in the solution at a temperature range of 90 to $100^{\circ}C$ under 1${\sim}$3 atmospheres. The Mohr's salt thus formed was hydrolyzed under 1 to 3 atmospheres, in 14 to 72 g/l of iron content in the solution pH 3 or 6 for two hours at 90 to $100^{\circ}C$. The results obtained was as follows; 1) In Mohr's salt solution, as the iron content was increased, with decreasing the concentration of hydrogen ion, the yield of iron oxide hydroxide was gradually increased. 2) When iron content in Mohr's salt solution was 42.81 g/l, 91.5% of iron was recovered in the form of $\alpha$-goethite similar to yellow grade of natural goethite. 3) When $\alpha$-goethite obtained was calcined of $500^{\circ}C$, it was turned into ${\alpha}$-ferric oxide with a redish brown colour.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.729-736
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• 2010

In this study, a magnetic stimulation (MS) device with controllable pulse forming technology and pulse shape (MS) is described. The MS device uses an IGBT with appropriate snubbers to switch coil currents up to 6 kA, enabling pulse forming technology control from 5 s to over 100 s. The induced electric field pulses use 2% - 34% less energy and generate 57% - 67% less coil heating compared to matched conventional cosine pulses. MS is used to stimulate rhesus monkey motor cortex in vivo with pulse forming technology of 20 to 100 s, demonstrating the expected decrease of threshold pulse amplitude with increasing pulse forming technology. The technological solutions used in the MS prototype can expand functionality, and reduce power consumption and coil heating in MS, enhancing its research and therapeutic applications.

• Bulletin of the Korean Chemical Society
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• v.14 no.6
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• pp.700-704
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• 1993

The photocatalytic alanine and hydrogen production reaction were studied by using CdS as a semiconductor photocatalysts. The rate of alanine and hydrogen production depends strongly on the temperature in heat treatment of CdS powder. In particular, the rate of alanine production, which was observed using Pt/CdS(A)-(CdS from Mitsuwa), was increased about six times than that of using Pt/CdS(B)-(CdS from Furruchi) under the same heat treatment condition at 500$^{\circ}$C. And the photocatalytic activity for alanine production using bare CdS(A) or Pt/CdS(A) was almost same with increasing temperature in heat treatment in the range of 100-600$^{\circ}$C. From X-ray diffraction data and photoluminescence spectrum, we conclude that the crystal structure changes of CdS(A) or strong interaction at interface of Pt and CdS contribute to increasing the rate of alanine and hydrogen production reaction.

• Korean Journal of Medicinal Crop Science
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• v.14 no.3
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• pp.143-147
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• 2006

This study was carried to investigate the effect of soil texture on the growth and the contents of quercetin-glycoside and lignans, and to improve the qualities of Saururus chinensis Baill. Soil texture resulted no significant effects on the number of nodes, the number of leaves, the number of branches and dry matter ratio. However, the shoot dry weight was higher in sandy loam, loam, silt loam and sand soil in that order. Although the weight of rhizomes of below 5 mm in diameter was not significantly different among soil textures, the weight of rhizomes between 5.1 and 10.9 mm and the weight of rhizomes of above 11 mm in diameter ranged $437{\sim}465\;g$ and was larger in clay loam than in other soil textures. No significance difference was showed in rhizome dry ratio ranging from 19.1 to 20.8%. The amount of quercetin-glycoside in leaves was higher in loam and sandy loam and ranged from 219.3 to 222.4 mg/100 g of quercetin-glycoside quercitrin, rutin, isoquercitrin and hyperin were higher in that order. On the other hand, quercetin-glycoside contents in stem were 14.8 mg/100 g and 12.4 mg/100 g in sandy and sandy loam, respectively, and were higher than in other soil textures of quercetin-glycoside constituents, the content of rutin was the highest. The content of lignans was increased in clay loam, loam, sandy loam, and sandy in that order of lignans, the manassatin B was the highest.

• Journal of Food Hygiene and Safety
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• v.14 no.3
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• pp.270-276
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• 1999

In previous reports, the authors isolated the algicidal marine bacterium, Alteromonas sp. SR-14 and demonstrated its growth inhibition of diatom, Chaetoceros calcitrans (C. calcitrans). In this paper, we studied the effects of cell free culture filtrate of Alteromonas sp. SR-14 on the growth of C. calcitrans, and the characteristics of the algal growth inhibition substance. The culture filtrate of Alteromonas sp. SR-14 grown in peptone broth showed growth inhibition activity against C. calcitrans. The reasonable culture conditions of the bacterium for producing of algal growth inhibition substances were $15~20^{\circ}$ in temperature, 7.0-9.0 in pH and $23~30{\textperthousand}$ in salinity, respectively. The algal growth inhibition activity of culture filtrate was increased from stationary phase in growth curve of Alteromonas sp. SR-14. The molecular weights of algal growth inhibition substances produced by Alteromonas sp. SR-14 were ranged about from 3 KDa to 12 KDa. Among the substances, less than 10 KDa fraction were stable by heating at $100^{\circ}$ for 10 minutes, while more than 10 KDa fraction were heat labile. According to the experimental results, the algal growth inhibition substance produced by the bacterium was not a single compound.

• Textile Coloration and Finishing
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• v.31 no.1
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• pp.14-24
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• 2019

In this study, dyeability of PET fabric was investigated depending on dyeing temperature, pressure, and leveling time using laboratory scale supercritical $CO_2(scCO_2)$ dyeing machine. Dyeing temperature, pressure, leveling time were varied from 100, 120, $130^{\circ}C$, 150, 200, 250bar, 40, 60, 80, 100min, respectively. It is proved that the higher temperature of $scCO_2$ dyeing process, the higher K/S value and the lower $L^*$ value, which in turn means the lower amount of dyeing molecules remained after process done. Compared 200bar with 250bar of dyeing pressure, $scCO_2$ dyeing fabrics under 250bar appeared to have a lower $L^*$ value, a higher K/S value than those from 200bar, meaning that dyeing color turns to darker with higher dyeing pressure. The experiments showed that the most ideal condition for $scCO_2$ dyeing process is $120^{\circ}C$, 250bar for 60 - 100min of leveling time.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.1-12
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• 2019

After making tea by steaming the Artichoke(Hellanthus tuberosus) nine times and drying them nine times, the ingredients and functions of the Artichoke tea were compared to those of M. It had 342.27kcal/100g in its own deloped Artichoke tea, 73.87g/100g of carbohydrates, 6.80g/100g of crude ash and 8.21g/100g of crude protein. The total of free sugars were 32.66mg/100, among them, fructose 17.40, sucrose 9.03 and glucose 6.05 mg/100g. The total mineral contents of the developed tea was 2,785.67mg/100g. It was 2,563.93mg/100g of potassium, 97.52mg/100g of calcium and 88.78mg/100g of magnesium. The saturated fat of Artichoke tea was 30.34mg/100g and unsaturated fat was 69.66mg/100g, among which the linoleic acid was 47.0mg/100%, palmitic acid was 25.31mg/100% and linolenic acid was 8.61mg/100g. DPPH radical scavenging was 34.2% of teas that were developed, 5.2% of M's for comparison, and 44.0% of index materials. ABTS radical scavenging was 93.0% of teas developed, 61.9% of M's tea and 47.6% of index materials, and SOD like activity was 2.7% of teas developed and 1.6% of M's tea. The flavonoid content was 2.8 fold of the tea developed, 2.0 fold of M's tea and 1.7 fold of index material. The polyphenol content was 38.2 fold, 8.92 fold of M's tea and 14.0 fold of index material. The inhibition rate for ${\alpha}$-glucosidase was 9.83% teas developed and 8.92% of M's. The sensory evaluation compares to the one time extract and the five time extract. Based on the one-time extract, color of tea developed was 83.7%, the M's tea was 50.0%, the flavor was 78%, M's tea was 42.5%, the delicate taste was 66.7% of teas developed and M's tea was 37.5% and the overall acceptability was 73.3% of teas developed, M's tea was 47.5%. The comparison of M's tea showed that the extract decreased as we made it, and the overall symbol level decreased to 46.3% after five time-extyracts, while that of the developed tea decreased to 73.3%. The Artichoke tea developed this way is believed to have greater antioxidant function, higher effective substance content, and a higher affinity than M's tea an index material for comparison purposes.