• Journal of Korean Society of Industrial and Systems Engineering
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• v.10 no.16
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• pp.101-106
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• 1987

Statistical control charts are useful tools to monitor and control the manufacturing processes and are widely used in most Korean industries. Many Korean companies, however, do not always obtain desired results from the traditional control charts by Shewhart such as the $\bar{X}$-chart, $\bar{X}$-chart, $\bar{X}$-chart, etc. This is partly because the quality charterstics of the process are not distributed normally but are skewed due to the intermittent production, small lot size, etc. In Shewhart $\bar{X}$-chart. which is the most widely used one in Kora, such skewed distributions make the plots to be inclined below or above the central line or outside the control limits although no assignable causes can be found. To overcome such shortcomings in nonnormally distributed processes, a distribution-free type of confidence interval can be used, which should be based on order statistics. This thesis is concerned with the design of control chart based on a sample median which is easy to use in practical situation and therefore properties for nonnormal distributions may be easily analyzed. Control limits and central lines are given for the more famous nonnormal distributions, such as Gamma, Beta, Lognormal, Weibull, Pareto, Truncated-normal distributions. Robustness of the proposed median control chart is compared with that of the $\bar{X}$-chart; the former tends to be superior to the latter as the probability distribution of the process becomes more skewed. The average run length to detect the assignable cause is also compared when the process has a Normal or a Gamma distribution for which the properties of X are easy to verify, the proposed chart is slightly worse than the $\bar{X}$-chart for the normally distributed product but much better for Gamma-distributed products. Average Run Lengths of the other distributions are also computed. To use the proposed control chart, the probability distribution of the process should be known or estimated. If it is not possible, the results of comparison of the robustness force us to use the proposed median control chart based oh a normal distribution. To estimate the distribution of the process, Sturge's formula is used to graph the histogram and the method of probability plotting, $\chi$$^2$-goodness of fit test and Kolmogorov-Smirnov test, are discussed with real case examples. A comparison of the proposed median chart and the $\bar{X}$ chart was also performed with these examples and the median chart turned out to be superior to the $\bar{X}$-chart.

• KSBB Journal
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• v.27 no.1
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• pp.67-74
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• 2012

In this study, the optimum conditions of fermentation were determined by isolating the microorganisms with the ability to bioconvert the Citrus peel flavonoid, and the effect of the fermented Citrus peel extract which was bioconverted on the oxidative damage of HIT-T15 cell was investigated. The Aureobasidium pullulans Y-12 was isolated and identified with the strains having bioconversion activity. The fermentation conditions for bioconversion activity were confirmed to be optimal when culturing for three days at $25^{\circ}C$, 150 rpm in a culture medium containing 5% Citrus peel power and 0.8% casitone. As a result of bioconversion, 32.8 mg/g and 21.5 mg/g of naringenin and hesperetin, which were aglycone flavones, were produced respectively. Also in the flavonoid content, it was confirmed that FCP produced 154.8 mg/g while CP produced 33.7 mg/g, thus producing more by approximately 4.6 times. As a result of treating FCP and CP after inducing the oxidative damage for HIT-T15 cell by treating the deoxy-D-ribose with $IC_{50}$ (38 mM) concentration, the surviving rate was recovered to 90% for FCP treatments in the 0.01 mg/mL concentration and for CP treatments in the 0.025 mg/mL concentration. Also in the insulin secretion rate, FCP treatments increased by 206% and CP treatments by 132% when treated in the 0.1 mg/mL concentration. As the bioconverted FCP can inhibit the oxidative damage of HIT-T15 cell in the low concentration, it was considered its usability as the functional material for prevention of the type 2 diabetes.

• Journal of Embryo Transfer
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• v.29 no.3
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• pp.249-255
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• 2014

Programmed cell death or apoptosis is associated with changes in $K^+$ concentration in many cell types. Recent studies have demonstrated that two-pore domain $K^+$ ($K_{2P}$) channels are involved in mouse embryonic development and apoptotic volume decrease of mammalian cells. In cerebellar granule neurons that normally undergo apoptosis during the early developmental stage, TASK-1 and TASK-3, members of $K_{2P}$ channels, were found to be critical for cell death. This study was performed to identify the role of $K^+$ channels in the $H_2O_2$-induced or cryo-induced cell death of mouse and bovine embryos. Mouse and bovine two-cell stage embryos (2-cells) exposed to $H_2O_2$ for 4 h suffered from apoptosis. The 2-cells showed positive TUNEL staining. Treatment with high concentration of KCl (25mM) inhibited $H_2O_2$-induced apoptosis of 2-cells by 19%. Cryo-induced death in bovine blastocysts showed positive TUNEL staining only in the cells near the plasma membrane. Cryoprotectant supplemented with 25 mM KCl reduced apoptosis slightly compared to cryoprotectant supplemented with 5 mM KCl. However, the combination of antioxidants (${\beta}$-mercaptoethanol) with 25 mM KCl significantly decreased the rate of $H_2O_2$-induced and cryo-induced apoptosis compared to treatments with only antioxidants or 25 mM KCl. These results show that blockage of $K^+$ channel efflux for a short-time reduces $H_2O_2$- and cryo-induced apoptosis in mouse and bovine embryos. Our findings suggest that apoptosis in mouse and bovine embryos might be controlled by modulation of $K^+$ channels which are highly expressed in a given cell type.

• Korean Journal of Animal Reproduction
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• v.14 no.4
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• pp.237-244
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• 1990

These studies were carried out to investigate the effects of the follicles size, hormone supplementation, semen types and capacitation methods on in vitro maturation and fertilization of bovine follicular oocytes. The ovaries were obtained from slaughtered Korean Native cows. The follicular oocytes surrounded with cumulus cells were recovered by aspirating follicular fluid from the visible follicles of diameter 3~5mm. The follicular oocytes were cultured in TCM-199 medium containing hormones, FCS, ECS, BFF and MCC for 24~48hrs. in a incubator with 5% CO2 in air at 38.5$^{\circ}C$ and then matured oocytes were again cultured for 18~20hrs. with motile capacitated sperm in the TCF(Tyroide calcium-free) solution containing 200$\mu\textrm{g}$/ml of heparin. The results obtained in these experiments were summarized as follows : 1. The oocytes classified as "A, B, C, D and Degenerative" depending morphological integrity and those were 61.4%, 12.1%, 19.2%, 4.2% and 3.0% of the total oocytes recovered, respectively. The maturation and fertilization rate of the A, B, C class follicular oocytes, cultured in the TCM-199 medium supplemented with 10% FCS were 89.1%, 78.0%, 52.6% and 78.1%, 66.1%, 33.3%, respectively. 2. The average number of the follicular oocytes recovered from follicles size, 1~2mm, 3~5mm and above 5mm in dimeter were 67, 98 and 63, respectively. The maturation and fertilization rate of the follicular oocytes, cultured in the TCM-199 medium were 56.7%, 82.5%, 46.0% and 44.8%, 71.4%, 28.6%, respectively. 3. The maturation and fertilization rate of follicular oocytes, cultured in the TCM-199 medium supplemented with 5%, 10%, 15%, 20% FCS and hCG, HCG, $\beta$-estradiol were 76.0%~82.3% and 26.2%~70.0%, and those values were higher the supplementation of the hormone than the non-supplementation. 4. The fertilization and cleavage rate of the follicular oocytes, inseminated with spermatozoas of epididymis cauda, neat and frozen semen were 63.3%, 73.3%, 70.0% and 32.7%, 37.8%, 38.3, respectively. 5. The fertilization and cleavage rate of follicular oocytes, fertilized with capacitated spermatozoas by heparin, BFF and HIS methods were 70.0%, 53.8%, 34.2% and 38.3%, 23.1%, 17.1%, respectively. And the fertilization and cleavage rate were higher method of heparin than other methods.r methods.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.2
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• pp.195-202
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• 2018

As a rule, geological disposal is considered a safe method for final disposal of high-level radioactive waste. However, some long-lived fission products like $^{99}Tc$ and $^{129}I$ contained in spent nuclear fuel are highly mobile as less sorbing anionic species in the subsurface environment and can mainly cause exposure dose to the ecosystem by emission of beta rays in the hundreds of keV range. Therefore, if these two nuclides can be separated and converted with high efficiency into radioactively unharmful nuclides, this would have a positive effect on disposal safety. One candidate method is to transmute these two nuclides in nuclear reactors into short-lived nuclides or into stable nuclides. For this purpose, it is necessary to evaluate which reactor type is more efficient in burning these two nuclides. In this study, the simulation results of nuclear transmutation of $^{99}Tc$ and $^{129}I$ in light water reactor (PWR), heavy water reactor (CANDU) and fast neutron reactor (SFR, MET-1000) are compared and discussed.

• Molecules and Cells
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• v.43 no.1
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• pp.66-75
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• 2020

Saturated fatty acids contribute to β-cell dysfunction in the onset of type 2 diabetes mellitus. Cellular responses to lipotoxicity include oxidative stress, endoplasmic reticulum (ER) stress, and blockage of autophagy. Palmitate induces ER Ca²⁺ depletion followed by notable store-operated Ca²⁺ entry. Subsequent elevation of cytosolic Ca²⁺ can activate undesirable signaling pathways culminating in cell death. Mitochondrial Ca²⁺ uniporter (MCU) is the major route for Ca²⁺ uptake into the matrix and couples metabolism with insulin secretion. However, it has been unclear whether mitochondrial Ca²⁺ uptake plays a protective role or contributes to lipotoxicity. Here, we observed palmitate upregulated MCU protein expression in a mouse clonal β-cell, MIN6, under normal glucose, but not high glucose medium. Palmitate elevated baseline cytosolic Ca²⁺ concentration ([Ca²⁺]_i) and reduced depolarization-triggered Ca²⁺ influx likely due to the inactivation of voltage-gated Ca²⁺ channels (VGCCs). Targeted reduction of MCU expression using RNA interference abolished mitochondrial superoxide production but exacerbated palmitate-induced [Ca²⁺]_i overload. Consequently, MCU knockdown aggravated blockage of autophagic degradation. In contrast, co-treatment with verapamil, a VGCC inhibitor, prevented palmitate-induced basal [Ca²⁺]_i elevation and defective [Ca²⁺]_i transients. Extracellular Ca²⁺ chelation as well as VGCC inhibitors effectively rescued autophagy defects and cytotoxicity. These observations suggest enhanced mitochondrial Ca²⁺ uptake via MCU upregulation is a mechanism by which pancreatic β-cells are able to alleviate cytosolic Ca²⁺ overload and its detrimental consequences.

• Journal of Life Science
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• v.12 no.1
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• pp.77-86
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• 2002

Chitin, a $\beta$-1,4 polymer of N-acetyl-D-glucosamine, is one of the most abundant organic compounds in nature. Chitinase (EC 3.2.1.14) is an enzyme that degrades chitin to chito-oligosaccharides, diacetyl rhitobiose and N-acetyl-D-glucosamine. An extracellular chitinase-producing bacterial strain was isolated from soil and named to as Bacillus subtilis JK-56. Optimum culture condition of B. subtilis JK-56 for the production of chitinase was 1% chitin, 0.5% polypepton, 0.1% KCl, 0.05% MnS $O_4$.4$H_2O$, 37$^{\circ}C$, initial pH 7.0 and 40 hour culture time. When B. subtilis JK-56 was grown in the optimum medium, one major active band and two minor active bands were detected by native-PAGE and active staining of the gel. Among them, the major band was purified from the culture supernatant by 70% ammonium sulfate precipitation and native-PAGE with BIO-RAD Model 491 Prep-Cell and named as Chi-56A. Its molecular weight was estimated to be 53kDa monomer and the isoelectric point (pI) was pH 4.3. The pH and temperature for the optimum activity of Chi-56A were pH 6.0 and $65^{\circ}C$, respectively. Chi-56A was stable up to $65^{\circ}C$ and in alkaline region. Its $K_{m}$ value for colloidal chitin was 17.33g/L. HPLC analysis of the reaction products confirmed that Chi-56A was an exo type chitinase.e.

• Journal of Nutrition and Health
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• v.44 no.1
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• pp.16-28
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• 2011

Oxidative stress leads to the induction of cellular oxidative damage, which may cause adverse modifications of DNA, proteins, and lipids. The production of reactive species during oxidative stress contributes to the pathogenesis of many diseases. Antioxidant defenses can neutralize reactive oxygen species and protect against oxidative damage. The aim of this study was to assess the antioxidant status and the degree of DNA damage in Korean young adults using glutathione s-transferase (GST) polymorphisms. The GSTM1 and GSTT1 genotypes were characterized in 245 healthy young adults by smoking status, and their oxidative DNA damage in lymphocytes and antioxidant status were assessed by GST genotype. General characteristics were investigated by simple questionnaire. From the blood of the subjects, GST genotypes; degree of DNA damage in lymphocytes; the erythrocyte activities of superoxide dismutase, catalase, and glutathione peroxidase; plasma concentrations of total peroxyl radical-trapping potential (TRAP), vitamin C, ${\alpha}$- and ${\gamma}$-tocopherol, ${\alpha}$- and ${\beta}$-carotene and cryptoxanthin, as well as plasma lipid profiles, conjugated diene (CD), GOT, and GPT were analyzed. Of the 245 subjects studied, 23.2% were GSTM1 wild genotypes and 33.4% were GSTT1 wild genotype. No difference in erythrocyte activities of superoxide dismutase, catalase, or glutathione peroxidase, and the plasma TRAP level, CD, GOT, and GPT levels were observed between smokers and non-smokers categorized by GSTM1 or GSTT1 genotype. Plasma levels of ${\alpha}$- and ${\gamma}$-tocopherol increased significantly in smokers with the GSTT1 wild genotype (p < 0.05); however, plasma level of ${\alpha}$-carotene decreased significantly in non-smokers with the GSTM1 wild genotype (p < 0.05). DNA damage assessed by the Comet assay was significantly higher in non-smokers with the GSTM1 genotype; whereas DNA damage was significantly lower in non-smokers with the GSTT1 genotype. Total cholesterol and LDL cholesterol levels were significantly higher in non-smokers with the GSTT1 genotype than those with the GSTT1 wild genotype (p < 0.05). In conclusion, the GSTM1 genotype or the GSTT1 wild genotype in non-smokers aggravated their antioxidant status through DNA damage of lymphocytes; however, the GSTT1 wild type in non-smokers had normal plasma total cholesterol and LDL-cholesterol levels. This finding confirms that GST polymorphisms could be an important determinant of antioxidant status and plasma lipid profiles in non-smoking young adults. Further study is necessary to clarify the antioxidant status and/or lipid profiles of smokers with the GST polymorphism and to conduct a study with significantly more subjects.

• Journal of agriculture & life science
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• v.45 no.4
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• pp.121-133
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• 2011

Effects of roasting on vitamin E content, color, microstructure and moisture of peanuts, and vitamin E content in peanut oils prepared from the roasted peanuts were investigated. Runner-type peanuts were roasted at 140, 150, and $160^{\circ}C$ for 10-20 min. As roasting temperature and time increased, the CIELAB $L^*$ value of peanuts decreased while $a^*$ and $b^*$ values increased, resulting in formation of the golden brown color of roasted peanuts. Moisture ratio (M/Mo) and color $b^*$ value of peanuts roasted at 140 to $160^{\circ}C$ showed a correlation of $b^*=21.61\;(M/Mo)^2-40.62\;(M/Mo)+34.12$ ($R^2=0.9123$). Overall changes in the tocopherol contents of peanuts and peanut oils were significantly affected by roasting temperature and time (p<0.05). Roasting at $140^{\circ}C$ caused a slight increase in the levels of tocopherols of peanuts over roasting time up to 20 min (p<0.05). There was no significant change in the tocopherol levels of peanuts during roasting at $150^{\circ}C$ for 20 min (p>0.05). At $160^{\circ}C$, the levels of tocopherols significantly decreased during the initial 10 min of roasting (p<0.05) while there was no extended loss after 10 min, resulting in about 5, 12, 20, and 10% losses of ${\alpha}$-, ${\beta}$-, ${\gamma}$- and ${\delta}$-T, respectively. After 20 min, total tocopherols decreased by 18%. However, tocopherol contents of pressed peanut oils significantly decreased at all roasting temperatures (p<0.05). After roasting peanuts at $160^{\circ}C$ for 20 min, about 84% of initial ${\alpha}$-T in peanut oils was retained. ${\alpha}$-T was the most stable to roasting while ${\gamma}$-T was the least. Swollen epidermal cells on the inner surface and broken cell walls of parenchyma tissue of peanut cotyledon were observed in peanuts after roasting at $160^{\circ}C$ for 15 min. Severe changes in microstructure of peanut by roasting would contribute to vitamin E stability because of exposure of oil droplets in peanuts to oxygen.

• The Korean Journal of Oral and Maxillofacial Pathology
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• v.42 no.5
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• pp.111-118
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• 2018

Nicotine of tobacco component has a controversial impact in the clinical outcome of dental implants. Although numerous nicotine effects on bone healing around implants have been presented, it is rarely reported in vitro study about normal human osteoblast(NHost) from oral and maxillofacial area at the surface of implants. The purpose of the present study was to evaluate the effect of nicotine on the proliferation and differentiation response of NHost to plasmatic and salivary levels of nicotine reported in smokers at the surface of screw-type plasma-sprayed titanium implants. NHosts were seeded on the surface of titanium implants and cultured for 21 days in ${\alpha}-MEM$ supplemented with 10% FBS, 50mg/ml ascorbic acid, 5mM ${\beta}$-glycerophosphate and 100nM dexamethasone. Seeded implants were exposed to various nicotine concentration(0.05-0.5mg/ml) from 1 to 21 days, and characterized for cell morphology, proliferation, differentiation, alkaline phosphatase(ALP) activity and ionized calcium concentration(Cai) of medium. Continuous exposure to higher nicotine concentration(above 0.3mg/ml) induced a dose- and time-dependent vacuolation of the cytoplasm, and a tendency to detach from the implant surface. 0.05mg/ml(lower nicotine concentration) did not cause significant effects in the cell proliferation and ALP activity. 0.1-0.2mg/ml caused evident dose-dependent effects in increased cell proliferation, ALP activity and earlier onset of matrix mineralization at levels up to 0.2mg/ml, while a dose-dependent inhibitory effect at 0.3-0.5mg/ml. Cai concentration of control group was decreased at 14 days. Increased Cai concentration at 0.1-0.2mg/ml, decreased Cai concentration at 0.3mg/ml and no change at 0.5mg/ml during the culture period were seen. It suggested that nicotine concentration could paly an role in modulating NHost activity as a contributing factor associated with proliferation and differentiation of NHost at the surface of implants.