• The Korean Journal of Physiology
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• v.11 no.1
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• pp.37-44
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• 1977

In the previous study of the release, excretion, and plasma concentration of aldosterone in normal Koreans, the author found that urinary aldosterone excretion and aldosterone secretion rate of the Korean who usually take high amount of salt are significantly lower, in compared to Americans, although the plasma concentration is only tended to be low. The control of plasma aldosterone level depends on the secretion rate and the metabolic clearance of the hormone. In this experiments, the metabolic clearance rate of aldosterone was determined in normotensive korean and the effects of adrenal stimulations on the rates were also studied in the same subjects. The metabolic clearance rate of the normal Korean was not significantly different from those of the American, and shown a little increase in response to sodium restriction. These results indicate that the decrease in secretion rate rather than the increase in metabolic clearance Tate is the major factor maintaining lower plasma aldosterone level. After furosemide diuresis, on the contrary, the removal of aldosterone showed significant the decrease despite slight increase of secretion rate. This suggest that the reduction in metabolic clearance rate of the hormone during volume depletion found to be major cause of high plasma concentration. Additional potassium supply produced detectable decrease of metabolic clearance rate, but the changes were smaller than that of secretion rate, which suggested that the higher secretion rate could account for elevated plasma concentration of aldosterone rather than metabolic clearance. Above results also support author's previous evidences that the normal Korean who already adapted to a high sodium diet have ability to produce adequate aldosterone activity without producing detectable changes on the metabolic clearance rate under the condition of sodium restriction with approp riate potassium intake.

• Journal of Microbiology and Biotechnology
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• v.18 no.11
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• pp.1762-1767
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• 2008

Image contrast of whole bacteria was compared in Staphylococcus aureus and Escherichia coli depending on pre-stain suspension liquids by energy-filtering transmission electron microscopy. The two bacterial strains were suspended in three most commonly used liquids for negative staining (triple distilled water [DW], phosphate-buffered saline [PBS], and nutrient broth [NB]) and directly observed without staining or stained with neutralized potassium phosphotungstate (PTA), respectively. Even though in low contrast, unstained bacteria were observed owing to their inherent electron density and cell shape in zero-loss (elastic scattering) images. After being suspended in PBS, unstained bacteria appeared to have higher contrast and more refined periphery than DW-suspended ones, and extracellular appendage structures such as fimbriae and flagella could be discerned. The unstained bacteria appeared to be invariably surrounded with electron-lucent precipitates, possibly from PBS. As far as delineation of the structures, the combination of DW or PBS suspension with subsequent staining provided the most satisfactory results, as evidenced by the high contrast of bacterial morphology and appendage structures. However, after being suspended in NB and stained with PTA, bacteria often had too high contrast or poor staining, with electron-dense aggregates around the bacteria. These results suggest that suspension with concentrated organic aliquots including broth media before PTA staining could deteriorate image contrast, and should be used only in dilute form for visualizing bacterial morphology and appendage structures. Moreover the contrast enhancement of unstained bacteria by salt granules would be advantageous in demonstrating bacterial sorption of environmental particles like heavy metals, maintaining minimal contrast for cell imaging.

• Proceedings of the Korean Biophysical Society Conference
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• 2003.06a
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• pp.62-62
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• 2003

The native form of serpin (serine protease inhibitor) is kinetically trapped in metastable state. Metastability in these proteins is critical to their biological function. Serpins inhibit target proteases by forming a stable covalent complex in which the cleaved reactive site loop of the serpin is inserted into $\beta$-sheet A of the serpin with concomitant translocation of the protease to the opposite of the initial binding site. Despite recent determination of the crystal structures of a Michaelis protease-serpin complex as well as a stable covalent complex, details on the kinetic mechanism remain unsolved. In this study we constructed several $\alpha$$_1$-antitrypsin variants and examined their kinetic mechanism of loop translocation and formation of protease-serpin complex by stopped-flow experiments of fluorescence resonance energy transfer as well as quenched-flow experiment. We report here the relationship of serpin's conformational switch mechanism with Inhibitory activity. There is little direct correlation between loop insertion rate and inhibitory activity. Rather, disrupting a salt bridge between R196 and E354 accelerates loop translocation even though it impairs the inhibitory activity. Moreover, the serpin's reactive site loop is translocated, at least partially, prior to loop cleavage.

• Journal of the Korean Chemical Society
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• v.20 no.5
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• pp.398-405
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• 1976

A new compound, 1,2-bispyrazyl ethylene,is synthesized starting from pyrazine carboxylic acid and methyl pyrazine. The compound is characterized utilizing UV-VIS, IR, NMR and mass spectra along with elemental analysis. Spectroscopic properties are studied from UV-VIS and fluorescence spectra. From unusual salt effects on fluorescence spectra, it is believed that $(n,\;{\pi}^*)$ state has about the same energy as $({\pi},\;{\pi}^*)$ state. The compound fluoresces from $({\pi},\;{\pi}^*)$ state with the quantum yield of 0.025 at $77^{\circ}K$ compared to near unity for stilbene at the same temperature indicating the efficient intersystem crossing to triplet state, because of strong $(n,\;{\pi}^*)$ and $({\pi},\;{\pi}^*)$ mixing in the lowest excited state.

• Archives of Pharmacal Research
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• v.4 no.2
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• pp.109-115
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• 1981

In the present investigation, an attempt has been made to apply the methods of classical chemical kinetics to the hydrolytic reaction of pipethanate hydrochloride. By successively keeping all but one variable essentially constant, it has been possible to resolve the overall effect of the individual contributing factors. Since nearly all commercial pipethanate preparations are formulated with antacid, studies were made at several constant hydrogen ion concentration ranging pH 0.4 to 7.5. Rate measurement was also carried out in temperature ranging from $25^{\circ}C$ to $60^{\circ}C$. The hydrolysis of pipethanate is found to be of first order with respect to pipeethanate concentration over an experimental range of hydrogen ion concentration (pH 0407.5). The apparent activation energy(Ea) at pH 7.5 is 18.30 Kcal/mole and the frequency factor is $1.1408 {\times}10^{9}sec^{-1}$. The rate of the hydrolysis has a minimum at pH 2.5-3.5. In this region the half-life of pipethanate was about15.3 days at $60^{\circ}C$. The catalytic effect of water was found to be $K_{H_2O}$ = $3.16{\times}10^{-5}min^{-1}$ at $60^{\circ}C$. The catalytic constants of the hydroxyl ions and hydrogen ions at $60^{\circ}C$ were also found to be $K_{OH}$ = $4.5519{\times}10^{-5}min^{-1}$ and $K_{H}+$ = $1.1568{\times}10^{-2}min^{-1}$, respectively. This reaction appears to be primarily base catalyzed hydrolysis and pipethanate is relatively reluctant toward acid catalyzed hydrolysis. A positive primary salt effect was noted in the solution of phpethanate at pH 7.5 and at $60^{\circ}C$.

• Korean Journal of Materials Research
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• v.13 no.8
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• pp.537-542
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• 2003

($Y_{l-x}$ $Gd_{x}$ )$O_2$$_3$: $Eu^{ 3＋}$ red phosphors were prepared with the solvothermal synthesis using the 2-methoxy-ethanol solvents and the emission intensity was investigated that applied with the 254 nm wavelength and the maximum excitation wavelength for energy source. The used solvents for the solvothermal synthesis were made of nitrate salt solutions of Y, Gd and Eu. These solutions dropped in autoclave have be reacted with the solvothermal synthesis at $200^{\circ}C$ for 5hrs and the red phosphors prepared here in were showed the pure cubic phase after annealing at $1000∼1200^{\circ}C$. The brightness of ($Y_{l-x}$ $Gd_{x}$)$_2$$O_3$: $Eu^{3＋}$ phosphors particles was increased as an increase of Gd ratio. The maximum excitation wavelengths of ($Y_{l-x}$ $Gd_{x}$ )$_2$$O_3$: $Eu^{3＋}$ / phosphors particles were increased according to increasing Gd ratio from 253 nm to 259 nm wavelength. The maximum emission intensity of $Gd_2$$O_3$: $Eu^{3＋}$ (Y/Gd = 1/0) phosphors particles under UV 259 nm was found to be higher than the commercial product of $Y_2$$O_3$: $Eu^{3＋}$ phosphors.

• Resources Recycling
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• v.21 no.6
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• pp.39-44
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• 2012

An attempt to recover copper from electroless plating wastewater has been made through evaporation followed by the electrowinning method. From the determination of each element in electroless plating wastewater, the content of Cu was found to be 582 mg/l and small amount of Fe was also contained in it. Moreover, the content of COD and TOC which was resulted from the addition of Rochell salt was found to be 9,560 and 13,100 mg/l, respectively. The content of formic acid generated by the oxidation of formaldehyde was determined to be 7.73 %. As a result, current efficiency was decreased with increase in current density and therefore current density less than $40mA/cm^2$ should be maintained to obtain current efficiency more than 80 %. The content of Fe in Cu obtained by electrowinning was found to be 0.021 and 0.01 % at the concentration of sulfuric acid of 2 and 10 vol%, respectively.

• Journal of Fashion Business
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• v.14 no.6
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• pp.39-52
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• 2010

Interests in creating three-dimensionally designed fabric materials are growing rapidly in the sectors of the fashionable textiles with the creativity, new functions, and aesthetics. A number of finishing methods have been developed and proposed to add or create new functions and designs for silk fabrics. Due to the strong hydrogen bonds between the molecules of silk fibroins, the thermal treatment methods used in thermoplastic fiber processing, which can easily deform the synthetic filament fabrics to endow three-dimensional appearance to the fabrics, are not applicable to the silk fabric treatment. In order to modify the fine structure of silk fiber, neutral salt solution treatment methods have been suggested. In this study, the effect of the calcium nitrate solution on the physical and mechanical properties of silk fabrics was investigated by using the KES(Kawabata Evaluation System) equipment. Based on these findings, relationships between parameters, for example, the thickness and the compressional energy, the thickness and the compressional linearity, and the air permeability and the pore area statistical analysis were investigated. The relationships between the process parameters such as treatment temperature/time and the resulting fabric property parameters were also analyzed by using several SAS procedures.

• Journal of Surface Science and Engineering
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• v.51 no.4
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• pp.224-230
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• 2018

In this study, Mg films were prepared on hot dip aluminized steel (HDA) by using a sputtering method as a high corrosion resistance coating. The corrosion resistance of the Mg films was improved by controlling the morphology and the crystal structure of films by adjusting the Ar gas pressure during the coating process. Anodic polarization measurement results confirm that the corrosion resistance of the Mg films was affected by surface morphology and crystal structure. The corrosion resistance of the Mg coated HDA specimen increased with decreasing crystal size of the Mg coating and it was also improved by forming a film with denser morphology. The crystal structure oriented at Mg(101) plane showed the best corrosion resistance among crystal planes of the Mg metals, which is attributed to its relatively low surface energy. Neutral salt spray test confirmed that corrosion resistance of HDA can be greatly improved by Mg coating, which is superior to that of HDG (hot dip galvanized steel). The reason for the improvement of the corrosion resistance of Mg films on hot dip aluminized steel was due to the barrier effect by the Mg corrosion products formed by the corrosion of the Mg coating layer.

• Journal of Nutrition and Health
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• v.54 no.1
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• pp.1-9
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• 2021

This review describes the risk factors of the nutrition crisis in coronavirus disease 2019 (COVID-19) infections and suggests precision nutrition against long-term psychological and physiological stress. The mandatory quarantine and the social distancing are associated with an interruption of the lifestyle routine, resulting in psychological (i.e., boredom) and physiological stress. The stress with multiple causes and forms induces over-compensation of energy-dense food, such as sugary comfort food, and is defined as "food craving" because carbohydrates positively affect the psychological stability with serotonin secretion. The consumption of foods that promote an immune response against viral infections (vitamins & minerals; Cu, folate, Fe, Se, Zn, and Vit A, B6, B12, C, and D), reduce inflammatory cytokines (w-3 fatty acids, Vit D, fibers, and Mg), contain antioxidants (beta-carotene, Vit E, C, Se, and phenolics), and sleep-inducing proteins (serotonin, melatonin, and milk products) is essential. In addition, a reduced Vit D deficiency in winter due to less time spent outdoors under quarantine has been reported to be associated with viral infections. The case fatality rate of COVID-19 was significantly dependent on age, sex, race, and underlying health condition. To prevent malnutrition and cachexia in elderly people, weight loss and muscle wasting should be monitored and controlled. Inadequate protein intake, sedentary lifestyle, and inflammation are significant risk factors for sarcopenia. Moreover, relatively high intakes of fat or carbohydrate compared to low protein intake result in abdominal obesity, which is defined as "sarcopenic obesity." Keeping the food-safety guidelines of COVID-19, this study recommends the consumption of fresh and healthy foods and avoiding sugar, fat, salt, alcohol, and commercially frozen foods.