• Applied Microscopy
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• v.23 no.2
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• pp.53-77
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• 1993

In this study, an attempt was made to investigate the probable organelles participating in the secretion of biligrafin. The animals (ICR male mice, 25-30gm) were divided into normal control and 6 biligrafin injected groups to which 30% biligrafin (0.006ml/gm b.w.) were injected at 10, 20, 40, 80, 160 and 320 min prior to the sampling. The mice of each group were perfused through the heart with ice-cold 2.5% glutaraldehyde buffered with 0.1M Na-cacodylate (pH. 7.4) under the Na-pentobarbital (Nembtal 0.0015mg/gm b.w.) anesthesia and liver tissues were taken from each group. Some specimens were immersed 1 hr in the same solution used in the perfusion. After an overnight rinse in 0.1M Na-cacodylate buffer containing 10% DMSO and 7.6% sucrose, $75{\mu}m$ fronzen sections were made for cytochemical study. The sections were incubated in thiamin pyrophosphatase (TPPase) and inosine diphosphatase (ID Pase) media for 70 min at $37^{\circ}C$ respectively and acid phosphatase (AcPase) medium for 40 min at $37^{\circ}C$. They were postfixed in 1 % $OsO_4$ for 1 hr. The other specimens were immersed for 8 hrs in the fixative consisting of 2.5% glutaraldehyde and 3.0% paraformaldehyde buffered with Na-cacodylate (pH. 7.4). All of the osmificated specimens were processed for electron microscopy. In both normal and biligrafin injected groups, endoplasmic reticulum (ER), vacuoles, Golgi apparatus and lysosomes were seen in the vicinity of bile canaliculus. In the biligrafin injected groups, however, the Golgi apparatus appeared to be decreased and ER and vacuoles were dilated and increased. The rough endoplasmic reticulum (RER) having a few attached ribosomes appeared to be the round saccule, especially at 20 min after biligrafin injection. Smooth endoplasmic reticulum (SER) seemed to be formed by the detachment of ribosomes at the cisternal end of RER. The cistern of SER showed saccules which probably budded off to form the vacuole. The vacuoles were devoid of visible centents. This finding seemed to be in agreement with the biochemical property of the bile constituents. The fusion between the vacuoles and bile canaliculus were frequently seen in the groups injected with biligrafin. The lysosome did not show any changes in the biligrafin injected groups. Accumulation of some material and lipid droplets were seen at the 40 and 80 min after biligrafin injection, especially at the latter. At 160 and 320 min after biligrafin injections, however, they were decreased successively while the RER stack, free ribosomes and polysomes were increased. Although the reactive products of TPPase and IDPase were observed in the ER saccules and vesicles of the normal control and biligrafin injected groups, the fusion between the bile canaliculus and saccules or vesicles could easily be seen in the latter. The AcPase activity, however, was observed in the cistern at the maturing face of Golgi apparatus and lysosomes in both normal and biligrafin groups. The results suggest that the biligrafin is excreted via the vesicles, vacuoles or sacoules probably derived from the SER without the participation of Golgi apparatus and lysosomes, and the excess amount of material is stored as inclusions during the repairing of the organelles being overactive.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.1
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• pp.169-178
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• 2000

Perovskite oxide catalysts doped on porous alumina beads are prepared in a citric acid solution. To investigate the applicability of the catalysts to the hot gas cleanup, a series of experiments on the reduction characteristics of $NO_x$ by CO as a reducing agent are carried out in a packed bed reactor containing the catalysts. Parameters tested are the operating temperature and $CO/NO_x$ molar ratio. It is found that mixed complex oxides of $La_{0.5}Sr_{0.5}CoO_3$, $SrAl_{12}O_{19}$ and $LaAl_{11}O_{18}$ are uniformly distributed on the alumina beads. The conversion efficiency of $NO_x$ by CO sharply increases with the operating temperature up to $700^{\circ}C$ and then approaches 100% when $CO/NO_x$ molar ratio is greater than 1.0. The conversion efficiency of $NO_x$ is maintained by over 98% during a continuous operation for 23 hours at $800^{\circ}C$ and space velocity of $10700hr^{-1}$.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.1
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• pp.29-34
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• 2009

This study was performed under four operational conditions for nitrogen removal in metal finishing wastewater. The conditions include electrode gap, reducing agent, the recycling of treated wastewater in 1st step and the simultaneous treatment of nitrate and other materials. Result showed that the removal efficiency of $NO_3{^-}-N$ was highest at the electrode gap of 10 mm. As the electrode gap was shorter than 10 mm, the removal efficiency of $NO_3{^-}-N$ decreased due to increasing in concentration polarization on electrode. And, in case that the electrode gap was longer than 10 mm, the removal efficiency of $NO_3{^-}-N$ increased with an increase in energy consumption. Because hydrogen ions are consumed when nitrate is reduced, reducing reaction of nitrate was effected more in acid solution. As 1.2 excess amount of zinc was injected, the removal efficiency of $NO_3{^-}-N$ increased due to increasing in amount of reaction with nitrate. As the effluent from 1st step in the reactor was recycled into the 1st step, the removal efficiency of $NO_3{^-}-N$ increased. Because the zinc were detached from the cathode and concentration-polarization was decreased due to formation of turbulence in the reactor. The presence of $NH_4{^+}-N$ did not affect the removal efficiency of $NO_3{^-}-N$ but the addition of heavy metal decreased the removal efficiency of $NO_3{^-}-N$. As chlorine is enough in wastewater, the simultaneous treatment of nitrate and ammonia nitrogen may be possible. The problem that heavy metal decrease the removal efficiency of $NO_3{^-}-N$ may be solved by increasing current density or using front step of electrochemical process for heavy metal removal.

• Korean Journal of Environmental Agriculture
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• v.27 no.1
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• pp.86-91
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• 2008

Dicamba(3,6-dichloro-2-methoxybenzoic acid) is used to control for pre and post-emergence of annual and perennial broad-leaf weeds. It is very soluble in water and highly mobile, acidic herbicide. So it is easily moved and detected in groundwater. Zerovalent iron(ZVI) has been used for the reductive degradation of certain compounds through amination of nitro-substituted compounds and dechlorination of chloro-substituted compounds. In this study, we investigated the potential of ZVI for the oxidative degradation of dicamba in water. The degradation rate of dicamba by ZVI was more rapidly increased in pH 3.0 than pH 5.0 solution. The degradation percentage of dicamba was increased with increasing amount of ZVI from 0.05% to 1.0%(w/v) and reached above 90% within 3 hours of reaction. As a result of identification by GC-MS after derivatization with diazomethane, we obtained three degradation products of dicamba by ZVI. They were identified 4-hydroxy dicamba or 5-hydroxy dicamba, 4,5-dihydroxy dicamba and 3,6-dichloro-2-methoxyphenol. 4-Hydroxy dicamba or 5-hydroxy dicamba and 4,5-dihydroxy dicamba are hydroxylation products of dicamba. 3,6-dichloro-2-methoxyphenol is hydroxyl group substituted compound instead of carboxyl group in dicamba. We also confirmed the same degradation products of dicamba in the Fenton reaction which is one of oxidation processes using ferric sulfate and hydrogen peroxide. But we could not find out the dechlorinated degradation products of dicamba by ZVI.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.780-788
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• 1995

The purpose of this study was to compare the apical seal following root canal shaping by different methods. From fourty extracted mandibular 1st and 2nd molars, fourty mesial roots whose canals have some degree of curvature were selected. The mesiobuccal root portion including mesiobuccal portion of a crown was sectioned in each molar. After access cavity preparation for the mesiobuccal canal, working length was determined with # 10 K-file. The sectioned roots were implanted in acrylic resin block and randomly divided into four groups. The canals of group I were shaped by step-down/balanced force, group II by stepdown/step-back, group III by step-back and group IV by conventional method. All of the shaped canals were obturated by Thermafil method and access cavities were filled with IRM. The roots were removed from acrylic resin block and placed in 100 % humidity for 7days. Except the root surfaces of apical 2mm, the root surfaces were nail-varnished 3 times. After the roots were placed in 700 torr vacuum pressure for 15 minutes, they were immersed in 2% methylene blue solution for 4 days. Nail varnishes were removed with acetone. After that, the roots were decalcified in 5 % nitric acid and dehydrated with alcohol series. Transparent specimens were made by methyl salicylate and the quality of apical seal was assessed by measuring the leakage linearly. The results were as follows. 1. The leakage in canals shaped by step-down/balanced force method was significantly less than that in canals shaped by step-back method(P<0.05) and was less but not statistically than that in canals shaped by step-down/step-back method (P>0.05). 2. The leakage in canals shaped by step-down/step-back method was less than that in canals shaped by step-back method, but there was no statistical significance(P>0.05). 3. The leakage in canals shaped by conventional method was significantly more than that in canals shaped by step-down/balanced force, step-down/step-back and step-back method (P<0.05).

• Applied Biological Chemistry
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• v.26 no.2
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• pp.125-131
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• 1983

Formal net charges, bond populations, atomic orbital coefficients, energy components and conformation of dimethyl-2,2-dichlorovinylphosphate have been studied theoretically by using the CNDO/2 molecular orbital calculation method in attempt to describe the reactivity and the stability of the molecule. From the analysis of rate equation, molecular orbital calculations and identification of the hydrolysis products, 2,2-dichloroacetaldehyde and dimethylphosphoric acid, a mechanism of the hydrolysis of dimethyl-2,2-dichlorovinylphosphate(DDVP) has been proposed. The hydrolysis of DDVP proceeds through the mechanism of nucleophilic addition, typical Micheal reaction in basic media. Therefore, it appears probable that the attack by strong nucleophile, hydroxide ion occurs at the increased positive charge $C_2({\alpha})$ atom of a staggered conformation due to the inductive effect (-)I>(+)R of 2,2-dichlorovinyl, electron-attracting group. And then, the hydrolytic scission involves the $C_2({\alpha})-O_3$, ${\pi}-anti-bonding\;orbital({\pi}^*)$ in the subsequent reaction in aqueous solution.

• Applied Biological Chemistry
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• v.50 no.1
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• pp.42-47
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• 2007

Effect of chlorine dioxide ($ClO_2$) treatment on the microbial and physicochemical changes of fish paste was investigated. Fish paste samples were treated with 5, 10, and 50 ppm of $ClO_2$ solution, respectively, After $ClO_2$ treatment, fish paste samples were individually packaged and stored at 4$^{\circ}C$. The initial microbial loads of samples were 3.8 log CFU/g in total bacterial count, and 2.5 log CFU/g in yeasts and molds. Microbial growth of fish paste during storage showed that populations of total bacteria, yeast and mold were significantly reduced by $ClO_2$ treatment. In particular, the treatment of 50 ppm $ClO_2$ decreased total bacterial count the most significantly among the $ClO_2$ treated fish pastes. The pH and VBN of fish paste decreased with increasing $ClO_2$ concentration. Thiobarbituric acid reacted substance (TBARS) values of treated fish paste increased during storage, regardless of $ClO_2$ concentration. This study showed that 50 ppm chloride dioxide was the optimum dose level to extend the shelf-life of fish paste.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.5
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• pp.412-418
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• 2020

This paper produced an automatic fluid management system that can accurately control the specific gravity of etching solution(FeCl₃), and produced a SUS MASK applied to OLED. The target was set at 0.4 mm in diameter of the hole. As a result of this misconception, the etching speed increased when the specific gravity(S.G) value of FeCl₃ was changed from 1.43 to 1.49. And when the weight was 1.49, it was found that the vertical diameter was 0.405 mm, approaching the target. When pressure injection was varied from 2.0kg/cm2 to 3.5kg/cm2, the hole diameter at 3.0 kg/cm2 averaged 0.4mm, matching the target. The characteristics of the change in gravity were analyzed by applying the additive 1.2% and setting the weight at 1.430 by mixing HCl and H2O in FeCl₃ and fixing the injection pressure at 3.0 kg/cm2. When the weight changed from 1.460 to 1.469 the etching speed increased from 0.564 to 0.540. When the weight was 1.467, the hole diameter was measured at 0.4 mm and the target was reached.

• Korean Journal of Oriental Medicine
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• v.15 no.3
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• pp.83-91
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• 2009

$\beta$-glucan is a fiber-type complex sugar (polysaccharide) derived from the cell wall of baker's yeast, oat and barley fiber, and many medicinal mushrooms, such as maitake. The primary uses of $\beta$-glucan are to enhance the immune system, to lower blood cholesterol levels and to treat tumor. $\beta$-glucan has no systemic toxicity in mice, therefore it needed clinical trail to prove efficacy and safety for human. The subjects total 56 healty volunteers were divided into two groups including taken $\beta$-glucan tablet group and placebo group. Subjects were taken two tablets per oral for 4 weeks. They had agreed to take part in this experiment, and didn't take any other clinical trail products. After 4 weeks blood of subjects were checked. The check list are TNF-$\alpha$, INF-$\gamma$, IL-2, IL-4, total WBC, differential WBC, RBC, hemoglobin, platelet, MCV, MCH, MCHC, HCT, Na, K, Ca, Cl, AST, ALT, ALP, $\gamma$-GTP, total protein, triglyceride, total cholesterol, total bilirubin, albumin, uric acid, creatinine, BUN, pH, protein, glucose, ketone body, blood, bilirubin. We evaluated efficacy by cytokines that compare before and after taking. Collected data were analyzed as two sample t-test, chi-square test and ANOVA using SAS V.9.1.This study results are that in TNF-$\alpha$ of $1^{st}$ efficacy measurement item, all of two groups figure were increased significantly compare to before figure. In IL4 of $2^{nd}$ efficacy measurement item, experimental group figure were decreased significantly but placebo group figure were increased. The conclusions show that based on the above results, $\beta$-glucan has favorable effect to enhance immune system, especially IL4 results showed that it has effect to improve the allergic immune system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.1
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• pp.499-505
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• 2013

Cr(VI)-4-(dimethylamino)pyridine[4-(dimethylamino)pyridinium chlorochromate] was synthesized by the reaction of 4-(dimethylamino)pyridine with chromium trioxide in 6M-HCl, and characterized by IR, ICP. The oxidation of benzyl alcohol using 4-(dimethylamino)pyridinium chlorochromate in various solvents showed that the reactivity increased with the increase of the dielectric constant(${\varepsilon}$), in the order: cyclohexene$H_2SO_4$ solution), 4-(dimethylamino)pyridinium chlorochromate oxidized benzyl alcohol and its derivatives(p-$OCH_3$, m-$CH_3$, H, m-$OCH_3$, m-Cl, m-$NO_2$) smoothly in DMF. Electron-donating substituents accelerated the reaction, whereas electron acceptor groups retarded the reaction. The Hammett reaction constant(${\rho}$) was -0.68(303K). The observed experimental data was used to rationalize the hydride ion transfer in the rate-determining step.