• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.4
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• pp.397-410
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• 2018

When considering the long-term safety assessment of spent-nuclear fuel management, americium is one of the most radio-toxic actinides. Although spectroscopic methods are widely used for the study of actinide chemistry, application of those methods to americium chemistry has been limited. Herein, we purified $^{241}Am$ to obtain a highly pure stock solution required for spectroscopic studies. Quantitative and qualitative analyses of purified $^{241}Am$ were carried out using liquid scintillation counting, and gamma and alpha radiation spectrometry. Highly sensitive absorption spectrometry coupled with a liquid waveguide capillary cell and time-resolved laser fluorescence spectroscopy were employed for the study of Am(III) hydrolysis and oxalate (Ox) complexation. $Am^{3+}$ ions under acidic conditions exhibit maximum absorbance at 503 nm, with a molar absorption coefficient of $424{\pm}8cm^{-1}{\cdot}M^{-1}$. $Am(OH)_3(s)$ colloidal particles formed under near neutral pH conditions were identified by monitoring the absorbance at around 506-507 nm. The formation of ${Am(Ox)_3}^{3-}$ was detected by red-shifts of the absorption and luminescence spectra of 4 and 5 nm, respectively. In addition, considerable enhancements of the luminescence intensities were observed. The luminescence lifetime of ${Am(Ox)_3}^{3-}$ increased from 23 to 56 ns, which indicates that approximately six water molecules are replaced by carboxylate ligands in the inner-sphere of the Am(III). These results suggest that ${Am(Ox)_3}^{3-}$ is formed through the bidentate coordination of the oxalate ligands.

• Journal of Mushroom
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• v.17 no.3
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• pp.99-106
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• 2019

To improve the productivity of shiitake mushroom (Lentinula edodes), seven different types of media for liquid spawn (denoted as "A" to "G") were prepared with 0.3% soybean meal and varying sugar and glucose concentrations. During 14 days of incubation, the pH of the liquid culture gradually acidified with increasing incubation period. Additionally, there was a significant, but not prominent, difference in the degree of acidification depending on the sugar to glucose ratio. Liquid spawn culture "G," which had the highest sugar content was the most acidic on the last day of incubation. Mycelium dry weight increased significantly with increasing incubation period, and there was no significant difference in mycelium dry weight irrespective of the sugar to glucose ratio even after 14 days of culture. The inoculation of liquid spawn in sawdust medium with an inoculation volume ${\geq}45mL$ and incubation period of 15 to 18 days were the optimal culture conditions. Productivity of fruit bodies in sawdust medium and mushrooms treated with liquid spawn was significantly higher compared to solid spawn treatment. The mushrooms treated with liquid spawn had better chewiness, and the free amino acid content, which is associated with savory taste, was higher in these mushrooms compared to those treated with solid spawn.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.559-569
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• 2022

This study investigated the acidification and mixing with seawater of groundwater, stream water, and reservoir water in the Hunghae area of Pohang City, as well as the source of water expelled to the stream by liquefaction induced by the Pohang earthquake on 15 November 2017. Geologically, the area consists of Tertiary sedimentary rocks. We collected six samples of groundwater, five of reservoir water, four of stream water, two of liquefaction water, and one of seawater to analyze the chemical composition and stable isotopes (𝛿D and 𝛿¹⁸O). Gogkang Stream flows eastward through the central part of the study area into the East Sea. The groundwater and reservoir water in the lower part of the stream are acidic (pH < 4), have a Ca(Mg)-SO₄ composition, and high concentrations of Al, Fe, and Mn, likely due to the oxidation of pyrite in Tertiary rocks. The groundwater in the upper part of the stream have a Ca(Na)-HCO₃(Cl) composition, indicating the mixing of seawater with the stream water. The 𝛿D and 𝛿¹⁸O isotope data indicate the isotopic enrichment of reservoir water by evaporation. Based on the chemical and isotopic data, it is inferred that the two samples of liquefaction water originated from alluvium water in a transition zone with stream water, and from deep and shallow groundwaters that has been infiltrated by seawater, respectively.

• Korean Journal of Plant Resources
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• v.37 no.2
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• pp.214-224
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• 2024

In this study, the growth, physical characteristics of fruit and soil chemistry were investigated by grouping S. thea populations. The soil for each group was sandy loam or sandy loam, and it was analyzed to be slightly acidic to neutral, with a pH ranging from 5.6 to 7.0. Additionally, the leaf size was highest in the G7 group, and overall fruit growth was highest in the G1 group, confirming differences between the groups. The sweetness ranged from 16.8° Brix to 12.3° Brix, indicating a higher sweetness compared to Vaccinium oldhamill, blueberry, and blackberry. The correlation analysis between soil chemistry and S. thea growth characteristics revealed a significant negative correlation between calcium (Ca) and fruit growth characteristics. Furthermore, a significant positive correlation was observed between sodium (Na) and fruit acidity, as well as between cation exchange capacity (CEC) and fruit hardness.

• Biomolecules & Therapeutics
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• v.28 no.2
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• pp.202-210
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• 2020

Fluoxetine is used widely as an antidepressant for the treatment of cancer-related depression, but has been reported to also have anti-cancer activity. In this study, we investigated the cytotoxicity of fluoxetine to human gastric adenocarcinoma cells; as shown by the MTT assay, fluoxetine induced cell death. Subsequently, cells were treated with 10 or 20 µM fluoxetine for 24 h and analyzed. Apoptosis was confirmed by the increased number of early apoptotic cells, shown by Annexin V- propidium iodide staining. Nuclear condensation was visualized by DAPI staining. A significant increase in the expression of cleaved PARP was observed by western blotting. The pan-caspase inhibitor Z-VAD-FMK was used to detect the extent of caspase-dependent cell death. The induction of autophagy was determined by the formation of acidic vesicular organelles (AVOs), which was visualized by acridine orange staining, and the increased expression of autophagy markers, such as LC3B, Beclin 1, and p62/SQSTM 1, observed by western blotting. The expression of upstream proteins, such as p-Akt and p-mTOR, were decreased. Autophagic degradation was evaluated by using bafilomycin, an inhibitor of late-stage autophagy. Bafilomycin did not significantly enhance LC3B expression induced by fluoxetine, which suggested autophagic degradation was impaired. In addition, the co-administration of the autophagy inhibitor 3-methyladenine and fluoxetine significantly increased fluoxetine-induced apoptosis, with decreased p-Akt and markedly increased death receptor 4 and 5 expression. Our results suggested that fluoxetine simultaneously induced both protective autophagy and apoptosis and that the inhibition of autophagy enhanced fluoxetine-induced apoptosis through increased death receptor expression.

• Journal of Photoscience
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• v.9 no.2
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• pp.302-304
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• 2002

pharaonis phoborhodopsin (ppR), a photophobic sensor of haloalkaliphilic bacteria, Natronobacterium phar-aonis, has retinal as a chromophore covalently bound to Lys in G-helix via a protonated Schiff base (PSB), as is the same as bacteriorhodopsin (bR). For ppR, the corresponding counter-ion is Asp residue (Asp75) located in C-helix. Here we investigated the influence of the protonated state of this counter-ion and its location on the chromophore configuration. Under alkaline condition, the chromophore configuration of D75E mutant was analyzed by HPLC. D75E had a much larger content of 13-cis isomer: the ratio of 13-cis to all-trans was 6:4 while the wild-type had this ratio of 1 :9. On the other hand, under acidic condition where Glu was associated, D75E had no 13-cis retinal isomer. Mutants whose Asp75 was replaced by neutral amino acids (D75N and D75Q) did not contain 13-cis retinal. Furthermore, retinal isomer compositions and the change in the visible ab- sorption spectra (indicating the dissociation state of Glu75) were measured under varying pH, and these were almost the same dependencies. These results indicate that an important factor determining the 13-cis isomer content is the presence of negative charge of the counter-ion against PSB, but not the size of this residue. Com- parison between the wild-type and D75E in alkaline solutions indicates the influence of the location of the counter-ion.

• Preventive Nutrition and Food Science
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• v.14 no.4
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• pp.335-342
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• 2009

Bioactive compounds were produced from carrot pomace by solid-state fermentation using Bacillus subtilis HA and Leuconostoc mesenteroides. The carrot pomace (CP) fermented by B. subtilis HA with 3% monosodium glutamate (MSG) showed higher production of various bioactive compounds, with 1.64 Pa·sn of consistency, 2.31% of mucilage content, 16.95 unit/g of fibrinolytic enzyme activity, 35.3 unit/g of proteolytic activity and 37.5 mg% of tyrosine content. The mucilage production was greatly dependent upon the concentration of MSG added. Most MSG added in CP was converted into mucilage (2.3%) including 0.83% poly-$gamma$-glutamic acid (PGA) with 1,505 kDa of molecular weight. The CP fermented secondly by Leuc. mesenteroides showed acidic pH and lower consistency. However, the fibrinolytic and proteolytic activities were increased. The secondly fermented CP showed the viable cell counts with $2.5{\time}108$ CFU/g of B. subtilis HA and $3.7{\time}109$ CFU/g of Leuc. mesenteroides, respectively. The freeze-dried fermented CP showed 2.88 Pa·sn of consistency, 24% of mucilage content and 104.9 unit/g of fibrinolytic enzyme activity, respectively. Also, the powder of fermented CP indicated viable cell counts of $8.0{\time}107$ CFU/g of B. subtilis and $4.0{\time}108$ CFU/g of Leuc. mesenteroides. Therefore, the fermented CP that was fortified with dietary fibers, fibrinolytic enzyme and probiotics could be utilized as valuable ingredients of functional foods in food or cosmetic industries.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.6
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• pp.897-904
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• 2011

For set up the processing method of Byeo-Nuruk, we investigated the quality characteristics of Byeo-Nuruk according to the mixture ratio of rice and wheat, as well as the addition rate of moisture. After 12 hours of incubation, the temperature of Nuruk increased dramatically and reached a maxium temperature at 36 hours. After 36 hours, the temperature decreased gradually and was maintained at about $31{\sim}38^{\circ}C$. The ranges of pH and titratable acidity of Byeo-Nuruk were 4.85 to 7.42 and 1.0 to 2.3, respectively. A higher content of wheat ratio in Byeo-Nuruk, was associated with higher enzyme activities of ${\alpha}$-amylase, glucoamylase, and acidic-protease. Further, at a 70% wheat ratio, a 25% addition rate of moisture showed the highest enzyme activity. In the mixture ratio between rice and wheat, the 50:50 and 30:70 treatments contained the highest levels of microorganisms.

• Fashion & Textile Research Journal
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• v.14 no.5
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• pp.866-877
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• 2012

The natural dyeing of hanji cotton fabrics with guava leaf extract was investigated. The temperature and time of dyeing were $40^{\circ}C$ and $90^{\circ}C$ for eighty minutes, respectively. In addition, the dyebath has been set at pH 5. Sn pre-mordanted fabrics showed the highest K/S value. Regardless of dyeing temperature, K/S values were high when Al, Cu, Fe-mordanted fabrics were dyed in post-mordanting and Sn-mordanted fabrics in pre-mordanting. The dyeing equilibrium was shown at the fourth time of repeated dyeing. In the processing of hanji cotton fabrics, K/S value was high when hanji cotton fabric was treated with soybean milk at $90^{\circ}C$. Similar K/S value of dyeing was shown when fabrics were processed with chitosan, regardless of dyeing temperature. High K/S value of dyeing was seen when fabrics processed with gallnut tannin at 40. Fabrics dyed with acidic water extract showed yellowish color. Fabrics dyed with alkaline water extract showed reddish color, and fabrics dyed with ethanol extract showed greenish yellow color. In case of Sn-mordanted fabrics, the washing fastness level was between 3 to 4, and other dyed fabrics showed low fastness. The dry cleaning fastness also showed very excellent result with level 4-5. The rubbing fastness of the fabrics was better in dry rubbing than in wet rubbing. For the light fastness, all dyed fabrics showed low fastness. For antibacterial activity, the dyed fabrics with guava leaf extract showed 99.9% of high antibacterial activity. Hanji cotton fabric maintained certain deodorization in the state of raw fabric. All dyed fabrics showed higher UV protection rate than control fabric.

• Bulletin of the Korean Chemical Society
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• v.34 no.9
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• pp.2747-2752
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• 2013

Surface modification of colloidal silica nanoparticles without disrupting the electric double layer of nanoparticles is a major challenge. In the work, silane was employed to modify colloidal silica nanoparticles without inducing bridge flocculation obviously. The effect of pH value of the silica sol, the amount of silane in feed, and reaction temperature on the graft amount and the final size of modified particles was investigated. The increased weight loss by TG and the appearance of $T_2$ and $T_3$ except for $Q_2$ and $Q_3$ signals by CP/MAS $^{29}Si$ NMR of the modified samples verified the successful grafting of silane. The graft amount reached 0.57 mmol/g, which was slightly lower than theory value, and the particle size remained nearly the same as unmodified particles for acidic silica sol at the optimum condition. For alkaline silica sol after modification, aggregates composed of several nanoparticles connected together with silane moleculars as the bridge appeared.