• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.14-20
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• 2018

Electric vehicles are environmentally friendly because they emit no exhaust gas, unlike gasoline automobiles. However, since they are driven by the electric power from batteries, the distance they can travel based on a single charge depends on their energy density. Therefore, the lithium-ion battery having a high energy density is a good candidate for the batteries of electric vehicles. Since the electrode is an essential component that governs their efficiency, the electrode manufacturing process plays a vital role in the entire production process of lithium-ion batteries. In particular, the coating process is a critical step in the manufacturing of the electrode, which has a significant influence on its performance. In this paper, we propose an innovative process for improving the efficiency and productivity of the coating process in electrode manufacturing and describe the equipment design method and development results. Specifically, we propose a design procedure and development method in order to improve the core plate coating quality by 25%, using a technology capable of reducing the assembly margin due to its high output/high capacity and improving the product capacity quality and assembly process yield. Using this method, the battery life of the lithium-ion battery cell was improved. Compared with the existing coating process, the target loading level is maintained and dispersed to maintain the anode capacity (${\pm}0.4{\rightarrow}{\pm}0.3mg/cm^2r$ reduction).

• Toxicological Research
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• v.25 no.4
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• pp.175-180
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• 2009

Lead (Pb) is a ubiquitously occurring environmental heavy metal which is widely used in industry and human life. Possibly due to a global industrial expansion, recent studies have revealed the prevalent human exposure to Pb and increased risk of Pb toxicity. Once ingested by human, 95% of absorbed Pb is accumulated into erythrocytes and erythrocytes are known to be a prime target for Pb toxicity. Most of the studies were however, focused on $Pb^{2+}$ whereas the effects of $Pb^{4+}$, another major form of Pb on erythrocytes are poorly understood yet. In this study, we investigated and compared the effects of $Pb^{4+}$, $Pb^{2+}$ and other heavy metals on procoagulant activation of erythrocytes, an important factor for the participation of erythrocytes in thrombotic events in an effort to address the cardiovascular toxicity of $Pb^{4+}$. Freshly isolated erythrocytes from human were incubated with $Pb^{4+}$, $Pb^{2+}$, $Cd^{2+}$ and $Ag^+$ and the exposure of phosphatidylserine (PS), key marker for procoagulant activation was measured using flow cytometry. As a result, while $Cd^{2+}$ and $Ag^+$ did not affect PS exposure, $Pb^{4+}$ and $Pb^{2+}$ induced significantly PS exposure in a dose-dependent manner. Of a particular note, $Pb^{4+}$ induced PS exposure with a similar potency with $Pb^{2+}$. PS bearing microvesicle (MV), another important contributor to procoagulant activation was also generated by $Pb^{4+}$. These PS exposure and MV generation by $Pb^{4+}$ were well in line with the shape change of erythrocyte from normal discocytes to MV shedding echinocytes following $Pb^{4+}$ treatment. Meanwhile, nonspecific hemolysis was not observed suggesting the specificity of $Pb^{4+}$-induced PS exposure and MV generation. These results indicated that $Pb^{4+}$ could induce procoagulant activation of erythrocytes through PS exposure and MV generation, suggesting that $Pb^{4+}$ exposure might ultimately lead to increased thrombotic events.

• Korean Journal of Animal Reproduction
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• v.18 no.2
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• pp.141-150
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• 1994

Morphological features of the interaction between the hatching blastocyst and implantation in pig were studied by electron microscopy. The observations extended from late blastocyst stage to the completion of trophoblastic erosion of the epithelium and early decidual transformation of the epithelium and early decidual transformation of the stromal cells. Between day 7 and 17 of pregnancy, blastocysts from 0.3 to 12 mm in diameter were flushed from the uterine horns of Dutch Landrace pigs. On the 7th of development in the pig blastocyst, the blastocyst shedded of the zona pellucida established the tips of microvilli and with bleb-like cytoplasmic protrusions of the epithelial cells. From day 11 on in pig embryo, the bilayered trophoblast undergoes a dramatic phase of elongation so that the initially spherical expanded blastocyst becomes tubular. In pig, close apposition to the uterine wall beg-ins at about 12 $^1$/$_2$ days and then attachment occurred during the afternoon of the 16th or 18th day post coitum. At this stage, embryonic loss compared with corpus luteum number is up to 40% of ovulated oocytes. Therefore, the implantation failture of these embryos may be mainly caused by morphological abnormality and failture of zona shedding.

• The Journal of Engineering Geology
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• v.20 no.3
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• pp.281-295
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• 2010

A new, automated apparatus is proposed for calculating the Soil-Water Characteristic Curve (SWCC), representing a simple and easily applied testing device for continuous measurements of the volumetric water content and suction of unsaturated soils. The use of this apparatus helps to avoid the errors that arise when performing experiments. Consequently, the apparatus provides greater accuracy in calculating the SWCC of unsaturated soils. The apparatus is composed of a pressure panel, flow cell, water reservoir, air bubble trap, balance, sample-preparation accessories, and measurement system, among other components. The air pressure can attain 300 kPa, and a general test can be completed in a short time. The apparatus can simply control the drying process and wetting process. The changes in volumetric water content that occur during the drying and wetting processes are shown directly in the SWRC program, in real time. As a case study, we performed an SWCC test of Joomunjin sand (75% relative density) to measure matric suction and volumetric water content during both the drying and wetting processes. The test revealed hysteresis behavior, whereby the water content on the wetting curve is always lower than that on the drying curve for a specific matric suction, during the wetting and drying processes. Based on the test results, SWCCs were estimated using the Brooks and Corey, van Genuchten, and Fredlund and Xing models. The van Genuchten model performed best for the given soil conditions, as it yielded the highest coefficient of determination.

• Analytical Science and Technology
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• v.26 no.2
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• pp.135-141
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• 2013

The purpose of this study is to determine the quantity of selenium in grains by hydride generation-inductively coupled plasma mass spectrometry. Two sample preparation methods, beaker and microwave digestions, are compared and the former shows better result. The optimum condition for hydride generation is 4.0 M for HCl, 3% for $NaBH_4$ with the sample flow of 0.6 mL/min. The detection limit is 0.02 ${\mu}g/kg$($3{\sigma}$) and improved by 10 times. Isobaric interferences on Se is removed by Octopole Reactoin Cell and $H_2$ (3.8 mL/min) shows better performance over He. However, in case Br exists in a matrix, $H_2$ could induce interferences on m/z 80 and 82 ($^{80}[BrH]^+$ and $^{82}[BrH]^+$). The accuracy of this experiment is examined successfully by analyzing several reference materials. The results for several domestic grain analysis show that the concentrations are between 12.7 ${\mu}g/kg$ and 29.6 ${\mu}g/kg$.

• Nutrition Research and Practice
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• v.9 no.2
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• pp.129-136
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• 2015

BACKGROUND/OBJECTIVES: A variety of immunomodulators can improve the efficacy of low-dose chemotherapeutics. Active hexose correlated compound (AHCC), a mushroom mycelia extract, has been shown to be a strong immunomodulator. Whether AHCC could enhance the antitumor effect of low-dose 5-fluorouracil (5-FU) via regulation of host immunity is unknown. MATERIALS/METHODS: In the current study Hepatoma 22 (H22) tumor-bearing mice were treated with PBS, 5-FU ($10mg{\cdot}kg^{-1}{\cdot}d^{-1}$, i.p), or AHCC ($360mg{\cdot}kg^{-1}{\cdot}d^{-1}$, i.g) plus 5-FU, respectively, for 5 d. $CD^{3+}$, $CD^{4+}$, $CD^{8+}$, and NK in peripheral blood were detected by flow cytometry. ALT, AST, BUN, and Cr levels were measured by biochemical assay. IL-2 and $TNF{\alpha}$ in serum were measured using the RIA kit and apoptosis of tumor was detected by TUNEL staining. Bax, Bcl-2, and TS protein levels were measured by immunohistochemical staining and mRNA level was evaluated by RT-PCR. RESULTS: Diet consumption and body weight showed that AHCC had no apparent toxicity. AHCC could reverse liver injury and myelosuppression induced by 5-FU (P < 0.05). Compared to mice treated with 5-FU, mice treated with AHCC plus 5-FU had higher thymus index, percentages of $CD^{3+}$, $CD^{4+}$, and NK cells (P < 0.01), and ratio of $CD^{4+}$/$CD^{8+}$ (P < 0.01) in peripheral blood. Radioimmunoassay showed that mice treated with AHCC plus 5-FU had the highest serum levels of IL-2 and $TNF{\alpha}$ compared with the vehicle group and 5-FU group. More importantly, the combination of AHCC and 5-FU produced a more potent antitumor effect (P < 0.05) and caused more severe apoptosis in tumor tissue (P < 0.05) compared with the 5-FU group. In addition, the combination of AHCC and 5-FU further up-regulated the expression of Bcl-2 associated X protein (Bax) (P < 0.01), while it down-regulated the expression of B cell lymphoma 2 (Bcl-2) (P < 0.01). CONCLUSIONS: These results support the claim that AHCC might be beneficial for cancer patients receiving chemotherapy.

• The Korean Journal of Pharmacology
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• v.28 no.2
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• pp.163-170
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• 1992

The present study was attempted to investigate the effect of cyclobuxine (a steroidal alkaloid) on generation of reactive oxygen metablite and myocardial damage promoted by an exogenous administeration of arachidonate in ischemic-reperfused hearts. Langendorff preparation of the isolated rat heart was made ischemic condition by reducing the flow rate to 0.5 ml/min for 45 min, and then followed by normal reperfusion (7 ml/min) for 5 min. The generation of superoxide anion was estimated by measuring the SOD-inhibitable ferricytochrome C reduction. The degree of lipid peroxidation in myocardial tissue was estimated from the tissue malondialdehyde (MDA) concentration using thiobarbituric acid method. The myocardial cell damage was observed by measuring LDH released into the coronary effluent. Sodium arachidonate $(0.1\;and\;1.0\;{\mu}g/ml)$ infused during the period of oxygenated reperfusion stimulated superoxide anion production dose-dependently. The rate of arachidonate-induced superoxide anion generation was markedly inhibited by cyclobuxine $(1.0\;and\;10\;{\mu}g/ml)$. The production of malondialdehyde was increased by infusion of arachidonate. This increase was prevented by superoxide dismutase (300 U/ml) and cyclobuxine $(1.0\;and\;10\;{\mu}g/ml)$. The release of LDH was increased by sodium arachidonate was also inhibited by superoxide dismutase and cyclobuxine. In conclusion, the present results suggest that cyclobuxine inhibits the production of reactive oxygen metabolite and myocardial damages which were promoted by an administeration of arachidonate during reperfusion of ischemic hearts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.6
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• pp.2021-2029
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• 2010

This paper suggested the method to design and analyze FMC robot's dispatching rule using the Simulation and Sequential Patterns. To do this, first of all, we built FMC using simulation and then, extracted signals that facilities call a robot, saved it as the log type. Secondly, we built robot's optimal path using the Sequential Pattern Mining with the results of analyzing the log and relationship between machine and robot actions. Lastly, we adapted it to the A corp.'s manufacturing line for verifying its performance. As a result of applying the new dispatching rule in FMC, total throughput and total flow time decrease because of decreasing material loss time and increasing robot utility. Furthermore, because this method can be applied for every manufacturing plant using simulation, it can contribute to advance total FMC efficiency as well.

• Nutrition Research and Practice
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• v.1 no.2
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• pp.105-112
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• 2007

Ascorbic acid has been reported to extend replicative life span of human embryonic fibroblast (HEF). Since the detailed molecular mechanism of this phenomenon has not been investigated, we attempted to elucidate. Continuous treatment of HEF cells with ascorbic acid at ($200{\mu}M$) from 40 population doubling (PD) increased maximum PD numbers by 18% and lowered $SA-{\beta}-gal$ positive staining, an aging marker, by 2.3 folds, indicating that ascorbic acid extends replicative life span of HEF cells. Ascorbic acid treatment lowered DCFH by about 7 folds and Rho123 by about 70%, suggesting that ascorbic acid dramatically decreased ROS formation. Ascorbic acid also increased aconitase activity, a marker of mitochondrial aging, by 41%, indicating that ascorbic acid treatment restores age-related decline of mitochondrial function. Cell cycle analysis by flow cytometry revealed that ascorbic acid treatment decreased G1 population up to 12%. Further western blot analysis showed that ascorbic acid treatment decreased levels of p53, phospho-p53 at ser 15, and p21, indicating that ascorbic acid relieved senescence-related G1 arrest. Analysis of AP (apurinic/apyrimidinic) sites showed that ascorbic acid treatment decreased AP site formation by 35%. We also tested the effect of hydrogen peroxide treatment, as an additional oxidative stress. Continuous treatment of $20{\mu}M$ of hydrogen peroxide from PD 40 of HEF cells resulted in premature senescence due to increased ROS level, and increased AP sites. Taken together, the results suggest that ascorbic acid extends replicative life span of HEF cells by reducing mitochondrial and DNA damages through lowering cellular ROS.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1281-1289
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• 2019

This study was conducted to evaluate the optimal operating condition of ultra-fine bubble washing machine for removing calcium chloride from road concrete structure. The diameter of the ultra-fine bubble was measured to 196.6 ± 100.6 nm and the ultra-fine bubble concentration was measured to 1.36 × 108 cell/ml. As a result of the performance on the spray device of the washing machine, it was confirmed that the washing efficiency of 93% and 91% appeared at 100cm and 150cm of injection distance at 100bar injection pressure. By increasing the ultra-fine bubble generation cycles from 2 to 6, the chloride removal rate increased from 1% to 7%. As the ultra-fine bubble generation air flow was lowered from 4 ml/min to 0.5 ml/min, it was confirmed that the washing efficiency increased up to 30%. The washing efficiency of ultra-fine bubble water was 25% higher than normal water.