• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.463-481
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• 2022

Phosphorous (P) is considered to be one of the key essential elements demanded by crop plants. Approximately 70 - 90% of phosphatic fertilizers applied to crops are fixed in soil as Ca, Fe, and Al metal cations, which are insoluble and thus not readily available for plant uptake. Therefore, most soils are deficient in plant available P. This is usually rectified by applying phosphate fertilizers continuously, although this is not economically viable or environmentally acceptable. The present paper reviews the mechanisms involved with phosphate solubilization and mineralization by phosphate solubilizing microorganisms (PSMs) with the associated factors that determine the success. PSMs are effectively involved in mediating the bioavailability of soil P. Their contribution includes mineralization of organic P solubilization of inorganic P minerals, and storing sizable amounts of P in biomass through different mechanisms such as the production of organic and inorganic acids, H₂S, siderophores, exopolysaccharides, and production of enzymes such as phosphatases, phytase, and phosphonatases/C-P lyases, which are capable of chelating the metal ions, forming complexes, and making plant available P. PSMs manifest a wide range of metabolic functions in different environments, resulting in significantly higher plant growth, enhanced soil properties, and increased biological activities. Therefore, development of bio-inoculants with efficient novel PSM strains and further investigations on exploring such strains from diverse ecological niches with multifunctional plant-growth-promoting traits are needed.

• Journal of Mushroom
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• v.21 no.3
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• pp.101-109
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• 2023

Lyophyllum decastes has been used for culinary purpose. The present study was conducted to evaluate the antioxidant and anti-inflammatory effects from methanol, acetone, and hot water extracts of L. decastes fruiting bodies. The acetone and methanol extracts showed the higher 1,1-diphenyl-2-picryl-hydrazy radical scavenging activities than that of the hot water extract at 0.5-2.0 mg/mL and was comparable to the BHT, the positive control. The ferrous ion chelating effects of the mushroom extracts at 0.5-2.0 mg/mL were significantly higher than that of BHT. The reducing power of acetone extract (2.12) was significantly lower than that of BHT (2.73) at 2.0 mg/ mL. The mushroom extracts also showed inhibitory effects on production of nitric oxide (NO), and expression of inducible nitric oxide synthase (iNOS) in lipopolysaccharide-induced murine macrophage cells in a concentration dependent manner. In vivo anti-inflammatory experiment on carrageenan-induced hind-paw edema of rat model, the acetone extract of the mushroom significantly suppressed the carrageenan-induced rat hind paw edema of rats in a dose dependently. The results suggest that the fruiting bodies of Lyophyllum decastes are a good natural resource of antioxidant and anti-inflammation.

• Progress in Superconductivity and Cryogenics
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• v.8 no.3
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• pp.13-17
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• 2006

The effect of the addition of the nano size $Y_2O_3$ powder on the microstructurte and superconducting properties of YBCO thin film deposited on LAO single crystalline substrate by TFA-MOD method was studied. Nano size $Y_2O_3$ powder was added to the stoichiometric precursor solution with a cation ratio of Y : Ba . Cu = 1 : 2 : 3 prepared using TFA as chelating agent. Precursor solutions with and without $Y_2O_3$ addition were coated on $LaAlO_3(100)$ single crystalline substrates by dip coating method. Calcination and conversion heat treatments were performed in controlled atmosphere containing moisture Current carrying capacity(Jc) of YBCO film was enhanced about 50% by $Y_2O_3$ doping and it is thought to be due to the better connectivity of YBCO grains and/or the flux pinning by the $Y_2O_3$ particles embedded in YBCO grains.

• Nuclear Engineering and Technology
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• v.55 no.5
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• pp.1892-1900
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• 2023

A protective oxide layer forms on the material surfaces of a Nuclear Power Plant during operation due to high temperature. These oxides can host radionuclides, the activated corrosion products of fission products, resulting in decommissioning workers' exposure. These deposited oxides are iron oxides such as Fe₃O₄, Fe₂O₃ and mixed ferrites such as nickel ferrites, chromium ferrites, and cobalt ferrites. Developing a new chemical decontamination technology for domestic CANDU-type reactors is challenging due to variations in oxide compositions from different structural materials in a Pressurized Water Reactor (PWR) system. The Korea Atomic Energy Research Institute (KAERI) has already developed a chemical decontamination process for PWRs called 'HyBRID' (Hydrazine-Based Reductive metal Ion Decontamination) that does not use organic acids or organic chelating agents at all. As the first step to developing a new chemical decontamination technology for the Pressurized Heavy Water Reactor (PHWR) system, we investigated magnetite dissolution behaviors in various HyBRID inorganic acidic solutions to assess their applicability to the PHWR reactor system, which forms a thicker oxide film.

• Analytical Science and Technology
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• v.20 no.1
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• pp.41-48
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• 2007

The determination method for the trace lead and cadmium in glass materials was developed by ICP-AES. The lead- and cadmium-DDTC chelates were formed by adding Na-DDTC (sodium diethyldithiocarbamate) as a chelating agent and extracted into MIBK (methyl-isobutyl ketone). Direct measuring of the trace lead and cadmium in glass was not possible because of the interferences of matrix elements as Na, Si, Mg and Ca of glasses unless solvent extraction of lead and cadmium was applied. This procedure was confirmed to be valid quantitative method of Pb and Cd analysis in glass did not influence of sample matrix, by applying it procedure to artifact sample and NIST SRM 1412.

• Analytical Science and Technology
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• v.20 no.1
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• pp.55-60
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• 2007

A sensitive technique for the determination of trace Cu(II) in various samples after the column preconcentration by adsorbing its N-benzoylphenylhydroxylamine (BPHA) onto benzophenone was developed. Several experimental conditions such as the pH of the sample solution, the amount of chelating agent, the amount of benzophenone, and the flowrate of sample solution and so forth were optimized. The interfering effects of diverse concomitant ions were investigated. Fe(III) and $CN^-$ interfered with more seriously than any other ions. However, the interference by these ions could be overcome sufficiently by adjusting the added volume of 0.01M BPHA to 10 mL. The dynamic range, the correlation coefficient ($r^2$) and the detection limit obtained by this proposed technique were 5.0~120 ng/mL, 0.9974, and 2.1 ng/mL, respectively. For validating this proposed technique, the aqueous samples (stream water, reservoir water, and wastewater), the plastic sample and the diluted brass sample were used. Recovery yields of 93~102% were obtained. These measured data were not different from ICP-MS data at 95% confidence level. This method was also validated by the rice flour CRM (normal, fortified) samples. Based on the results from the experiment, it was found that this proposed technique could be applied to the determination of Cu(II) in various real samples.

• FOCUS: LIFE SCIENCE
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• no.1
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• pp.5.1-5.3
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• 2024

The document discusses the regeneration of Partisil/Partisphere ion-exchange columns in chromatography. It mentions that column efficiency can diminish with use due to the accumulation of sample and/or mobile phase impurities at the head of the column. This can lead to a change in back pressure, lower column efficiency, and sometimes a change in selectivity. The document outlines a procedure that may restore column performance. The document also provides everyday practices to enhance the lifetime of a column. These include using only high-purity HPLC solvents and buffers, using freshly prepared mobile phases and buffers, filtering mobile phases to remove particulates, using appropriate sample clean-up procedures, using a guard column or pre-column filter, and working within the pressure and flow rate limitations of the column. For the regeneration of Partisil/Partisphere SAX, SCX, WAX, and WCX columns, the document suggests passing 20 column volumes of various mobile phases through the column. These include a buffer wash, distilled water, an acid wash, a chelating wash, a methanol wash, and a buffer for separation. The document emphasizes that not all of these wash steps are required for every column clean-up and that some chromatographers require only a combination of certain steps.

• Natural Product Sciences
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• v.13 no.3
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• pp.199-206
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• 2007

Antioxidant activity of 70% aqueous ethanolic extract of leaves of Justicia gendarussa (EJ) was evaluated. EJ was prepared by cold maceration method. The antioxidant potency of EJ was investigated employing various established in vitro systems, such as DPPH radical scavenging, nitric oxide (NO) scavenging, ${\beta}-carotene$ linoleic acid module system (${\beta}$ CLAMS), hydroxyl (OH) radical scavenging, anti lipid peroxidation. $IC_{50}$ values were determined in each experiment. Also, ferric ion reduction capacity of extracts in presence and absence of chelating agent (EDTA) and total antioxidant capacity were determined. Preliminary phytochemical investigation was carried out to know the nature of constituents present in the leaves and correlate it with antioxidant activity. Further total phenolic content was determined in EJ. $IC_{50}$ values of EJ were 123.09 ${\pm}$ 3.01, 643.0 ${\pm}$ 61.10, 132.3 ${\pm}$ 6.03, 68.5 ${\pm}$ 11.5 and 68.13 ${\pm}$ 1.38 ${\mu}g/mL$ in DPPH radical scavenging, NO scavenging, ${\beta}$ CLAMS, OH radical scavenging and anti lipid peroxidation activity respectively. In total antioxidant capacity assay, ascorbic acid equivalent value was found to be 205.56 ${\pm}$ 4.69 ${\mu}g/mg$ of extract. Total phenolic content was found to be 43.76 ${\pm}$ 4.27 ${\mu}g$ equivalent of gallic acid per mg of extract. Phytochemical investigation reveals the presence of flavonoids. The results indicate that EJ possess antioxidant activity and flavonoids are responsible for this activity.

• Korean Membrane Journal
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• v.9 no.1
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• pp.34-42
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• 2007

A perovskite-type ($La_{0.6}Sr_{0.4}Ti_{0.2}Fe_{0.8}O_{3-{\delta}}$) dense ceramic membrane was prepared by polymerized complex method, using citric acid as a chelating agent and ethylene glycol as an organic stabilizer. Effect of Ti addition on lanthanum-strontium ferrite mixed conductor was investigated by evaluating the thermal expansion coefficient, the oxygen flux, the electrical conductivity, and the phase stability. The thermal expansion coefficient in air was $21.19\;{\times}\;10^{-6}/K$ at 473 to 1,223 K. At the oxygen partial pressure of 0.21 atm ($20%\;O_2$), the electrical conductivity increased with temperature and then decreased after 973 K. The decrement in electrical conductivity at high temperatures was explained by a loss of the lattice oxygen. The oxygen flux increased with temperature and was $0.17\;mL/cm^2{\cdot}min$ at 1,223 K. From the temperature-dependent oxygen flux data, the activation energy of oxygen ion conduction was calculated and was 80.5 kJ/mol at 1,073 to 1,223 K. Also, the Ti-added lanthanum-strontium ferrite mixed conductor was structurally and chemically stable after 450 hours long-term test at 1,173 K.

• Journal of The Korean Society of Clinical Toxicology
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• v.12 no.1
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• pp.22-30
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• 2014

Purpose: The purpose of this systematic review was to evaluate the evidence regarding injury and poisoning associated with the clinical mercury thermometer. Methods: Electronic literature searches were conducted for identification of relevant studies and case reports of injury and poisoning associated with the clinical mercury thermometer. The search outcomes were limited to literature with English and Korean languages published from 1966. Studies related to occupational mercury exposure, or mercury exposure from sphygmomanometer, barometer, and fluorescent light were excluded. Results: A total of 60 reports, including 59 case reports, were finally included. Of those, nine cases pertained to an intact thermometer as a foreign body, 25 injuries were related to a thermometer, and 26 cases involved exposures to mercury from a broken thermometer. Case reports were classified according to severity into 16 mild, 41 moderate, and two severe cases. Two cases of mortality were reported, one was deliberate intravenous injection of mercury and the other was acute vapor inhalation of mercury from broken thermometers. Conclusion: Findings of this systematic review suggested that the mercury thermometer could cause various forms of poisoning and injury. In particular, inhalation of mercury vapor from a broken thermometer can lead to systemic toxicity requiring chelating therapy.