• Journal of Microbiology and Biotechnology
• /
• v.17 no.7
• /
• pp.1139-1146
• /
• 2007

Cultures of Saccharomyces cerevisiae were subjected to the effect of PEF (pulse electric field) and a source of selenium. The culture period after which yeast cells were subjected to PEF treatment was optimized, as was the duration of the exposure. Optimization of the nutrient medium composition in S. cerevisiae cultures resulted in an over 1.8-fold increase in selenium accumulation with relation to cultures on the initial substrate. Optimization of the pH value and of culture duration resulted in selenium accumulation increase by approximately 78%. A significant correlation was found between the accumulation of selenium in yeast cells and its concentration in the culture substrate. The highest accumulation of selenium in the biomass of yeast, approx. $240\;{\mu}g/g$ d.m., was obtained after 15-min exposure to PEF on a 20-h culture. An approx. 50% higher content of selenium in cells was recorded, as compared with the control culture without the application of PEF.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.6
• /
• pp.646-651
• /
• 2011

Cultures of Saccharomyces cerevisiae were treated with pulsed electric fields to improve accumulation of zinc in the biomass. Under optimized conditions, that is, on 15 min exposure of the 20 h grown culture to PEFs of 1500 V and 10 ${\mu}s$ pulse width, accumulation of zinc in the yeast biomass reached a maximum of 15.57 mg/g d.m. Under optimum zinc concentration (100 ${\mu}g$/ml nutrient medium), its accumulation in the cells was higher by 63% in comparison with the control (without PEFs). That accumulation significantly correlated against zinc concentration in the medium. Neither multiple exposure of the cultures to PEFs nor intermittent supplementation of the cultures with zinc increased the zinc accumulation. The intermittent supplementation of the cultures with zinc and multiple exposures on PEFs could even reduce the accumulation efficiency, respectively, by 57% and 47%.

• Analytical Science and Technology
• /
• v.6 no.1
• /
• pp.47-55
• /
• 1993

The quantitative determination of trace cyanide ion in the presence of sulfide ion has been studied by addition of cupric ion using differential pulse Cathodic Stripping Voltammetry. The detection limit of cyanide ion in the presence of $5.0*10^{-5}M$ sulfide ion and $1.0*10^{-3}M$ cupric ion was $2.0*10^{-7}M$ in KCI-Phosphate buffer(pH=7.0) at accumulation potential -0.30V and accumulation time 3.0 min.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.22 no.5
• /
• pp.1001-1034
• /
• 2008

This thesis is a study composed of eight chapters from 9. to 16. of the Maek Kyoung(脈經) Vol. VIII. ; the symptom & the pulse of Jaundice(黃疸), Malarial Disease(?疾). Carbuncle(癰腫) Intestines Carbuncle(腸癰), & c. It is as follows : Chapter 9 refers to the symptom, pulse, treatment and prognosis of Jaundice(黃疸) and Malarial Disease(?疾). Chapter 10 refers to the cause, symptom, pulse and treatment of Cardialgia(胸痺), Cardiagra(心痛) and Nephric Accumulation(賁豚). Chapter 11 refers to the symptom, pulse and treatment of Abdominal Fuliness(腹滿), Cold Mounting(寒疝) and Abiding Food(宿食). Chapter 12 refers to the symptom and pulse of Accumulation and Mass of the Five Viscera(五臟積聚). Chapter 13 refers to the cause, pathogenesis, symptom, pulse, treatment and prognosis of Terror and Palpitation due to Fright(驚悸), Hematemesis(吐血), Nasal Hemorrhage(?血), Metrorrhagia(下血) and Extravasated Blood(瘀血). Chapter 14 refers to the cause, pathogenesis, symptom, pulse and treatment of Vomiting(嘔吐), Hiccough(?) and Diarrhea(下利). Chapter 15 refers to the cause, pathogenesis, symptom, pulse and treatment of Atrophy of Lung(肺?), Pulmonary Abscess(肺癰), Lung-distention(咳逆上氣) and Phlegm(痰飮). Chapter 16 refers to the cause, pathogenesis, symptom, pulse. treatment and prognosis of Carbuncle(癰腫), Intestines Carbuncle(腸癰), Wound(金瘡) and Acute Eczema(侵淫瘡). There have been abundant investigations in China. But we couldn't find a clear result yet, and they were written in archaic texts and colloquial Chinese, therefore it is needed to be translated into Korean. And there was only one inaccurate translation with insufficient annotation. So I hope this study will be useful to develope Oriental Medical Diagnostics.

• Bulletin of the Korean Chemical Society
• /
• v.15 no.12
• /
• pp.1035-1037
• /
• 1994

An ultrasensitive and selective stripping voltammetric scheme for the determination of rhodium is described. By the use of combined accumulation and catalytic effects in formaldehyde-hydrochloric acid medium, substantial improvement in the limit of detection can be obtained. Optimal experimental conditions were found to be 0.42 M hydrochloric acid solution containing 0.008${\%}$ formaldehyde, an accumulation potential of -0.70 V (vs. Ag/AgCl) and an accumulation time of 20 s. The stripping mode was differential pulse voltammetry. In these conditions the limit of detection lies at 2 ${\times}$ l0$^{-12}$ M (0.21 ppt). The relative standard deviation at 5 ${\times}$ l0$^{-11}$ M was 4.9${\%}$ (n=5). There were no serious interferences from other platinum group metal ions being the tolerable amounts more than 500 times that of rhodium.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2015.11a
• /
• pp.139-140
• /
• 2015

The purpose of this study was to evaluate existing compressive strength equation with concrete exposed to high temperature by ultrasonic pulse velocity. As the result, original compressive strength equation is proper only for compressive strength of normal concrete. Therefore, an accumulation of experimental database of concrete exposed to high temperature is necessary for proposal of new compressive strength equation.

• Journal of Electrical Engineering and Technology
• /
• v.10 no.5
• /
• pp.2089-2098
• /
• 2015

With the continuous development in insulation of electrical equipment design, the reliability of the system has been enhanced. However, in the manufacturing process and during operation under continues stresses introduce local defects, such as voids between interfaces that can responsible to occurrence of partial discharge (PD), electric field distortion and accumulation of charges. These defects may lead to localize corrosion and material degradation of insulation system, and a serious threat to the equipment. A model of three layers of PI film with air gap is presented to understand the influence of interface and voids on exploitation conditions such as strong electrical field, PD activity and charge movement. The analytical analysis, and experimental results are good agreement and show that the lose contact between interfaces accumulate more residual charges and in consequences increase the electric field intensity and accelerates internal discharges. These residual charges are trapped charges, injected by the electrodes has often same polarity, so the electric field in cavities increases significantly and thus partial discharge inception voltage (PDIV) decreases. Contrary, number of PD discharge quantity increases due to interface. Interfacial polarization effect has opposite impact on electric field and PDIV as compare to void.

• Analytical Science and Technology
• /
• v.10 no.2
• /
• pp.119-125
• /
• 1997

A stripping voltammetric procedure for determining ruthenium was developed, based on the adsorptive accumulation of ruthenium in the presence of hydrazine in acidic acetate buffer. After preconcentration of ruthenium compelex and reduction, the ruthenium-catalyzed hydrogen current at -0.84V was measured by differential pulse voltammetry. Optimal experimental conditions were found to be a stirred acetate buffer solution(pH 2.0) containing 0.01M acetate and 0.01M hydrazine, accumulation potential of -0.76V, and a scan rate of 5mV/s. The detection limit was $2{\times}10^{-9}M$ for a 7 min accumulation period. The possible interferences by other platinum group metals were also investigated.

• Molecules and Cells
• /
• v.46 no.8
• /
• pp.486-495
• /
• 2023

Lipofuscins are oxidized lipid and protein complexes that accumulate during cellular senescence and tissue aging, regarded as markers for cellular oxidative damage, tissue aging, and certain aging-associated diseases. Therefore, understanding their cellular biological properties is crucial for effective treatment development. Through traditional microscopy, lipofuscins are readily observed as fluorescent granules thought to accumulate in lysosomes. However, lipofuscin granule formation and accumulation in senescent cells are poorly understood. Thus, this study examined lipofuscin accumulation in human fibroblasts exposed to various stressors. Our results substantiate that in glucose-starved or replicative senescence cells, where elevated oxidative stress levels activate autophagy, lipofuscins predominately appear as granules that co-localize with autolysosomes due to lysosomal acidity or impairment. Meanwhile, autophagosome formation is attenuated in cells experiencing oxidative stress induced by a doxorubicin pulse and chase, and lipofuscin fluorescence granules seldom manifest in the cytoplasm. As Torin-1 treatment activates autophagy, granular lipofuscins intensify and dominate, indicating that autophagy activation triggers their accumulation. Our results suggest that high oxidative stress activates autophagy but fails in lipofuscin removal, leaving an abundance of lipofuscin-filled impaired autolysosomes, referred to as residual bodies. Therefore, future endeavors in treating lipofuscin pathology-associated diseases and dysfunctions through autophagy activation demand meticulous consideration.

• Analytical Science and Technology
• /
• v.10 no.2
• /
• pp.114-118
• /
• 1997

A stripping voltammetric scheme for the determination of osmium, based on the adsorptive accumulation of osmium in the presence of hydroxylamine, was described. Cyclic voltammetry was used to characterize the redox and interfacial processes. Optimal experimental conditions were found to be a stirred 0.05M hydroxylamine hydrochloride solution(pH 1.8), accumulation at -0.65V for 60s, and a differential pulse mode with a scan rate of 10mV/s. The detection limit was $6.3{\times}10^{-8}M$(12ppb) with the optimal condition.