• Restorative Dentistry and Endodontics
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• v.7 no.1
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• pp.7-15
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• 1981

This study was conducted to compare the cleansing effect of various irrigants and the function of the quantity of irrigants in apical region. One hundred sixty single rooted teeth were divided into four groups and fourty teeth in each group were individually enlarged and irrigated with each of four irrigants as they would be during clinical condition. The four tested irrigants were Normal saline solution, 3.5% NaOCl, 15% EDTA, and 50% Citric acid. In each group, twenty teeth were flushed with 2cc of each irrigant and another twenty teeth with 5cc of same irrigant after use of each instrument. After final flush and dry, the roots were split longitudinally and the degree of cleansing at apical portion were evaluated under Stereoscope by three observers. The typical specimens of each group were also examined under Scanning electron microscope. The results were as follows. 1. There were no significant difference of cleansing effect among the tested irrigants. 2. 5cc flushed groups have more samples that have high degree of cleansing than 2cc flushed groups. 3. The canals irrigated with 2cc showed the presence of many dentin chips, tissue debris and smeared layer, whereas the 5cc groups revealed relatively clean canal surface and less smeared layer under Scanning electron microscope. 4. The teeth flushed with 5cc of EDTA and with 5cc of Citric acid showed the most clean canal surface at Scanning fictures.

• Journal of Soil and Groundwater Environment
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• v.15 no.5
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• pp.23-31
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• 2010

For an efficient remediation of Pb-contaminated soil (S-1) in a clay shooting range, a soil washing test was performed with mineral acid, organic acid, chelating agent, and chloride. The Pb extraction efficiency of extractant (0.1 M) used in the washing test showed the order of HCl > $Na_2$-EDTA > NTA > DTPA > citric acid > malic acid > succinic acid > acetic acid > $CaCl_2$ > $MgCl_2$, for S-1 soil. As compared to initial Pb concentration, extraction efficiency by the concentration of extractant was 93.35%, 80.80%, 73.92%, and 24.57% in S-1 soil for HCl (0.5 M, pH 1.10), $Na_2$-EDTA (0.01 M, pH 3.99), citric acid (0.5 M, pH 1.27), and $MgCl_2$ (0.1 M, pH 8.82), respectively. S-1 soil had 56.83% of residue form and 43.17% of non-residue form (18.04% of exchangeable form), respectively. Although the concentrations of these fractions sharply decreased after HCl washing, since the exchangeable forms with relatively large mobility are still distributed as high as 18.78% (to Pb total content in residual soils) in S-1 soil, it is necessary to devise a proper management plan for residual soils after soil washing application.

• Analytical Science and Technology
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• v.16 no.3
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• pp.206-211
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• 2003

The DC polarograms of some rare earth elements have been investigated in various pH solution and electrolytes. Samarium ion has two well-defined reduction waves at -1.75 V and -1.95 V in 0.1 M NaCl solution and those are a diffusion controlled in nature. Europium and ytterbium ions give also two step reduction waves at -0.75 V and -1.95 V for europium and -1.45 V and -2.00 V for ytterium in $(C_2H_5)_4NCl$ solution. On the other hand, lantanium and neodium ions show a single reduction wave at -1.75 V. The differences of half wave potentials between europium, ytterium and samarium ions make it possible to determine each ions in the mixed solution sponteniously. In case of europium ion, the stability constants for the complexs of $Eu^{3+}$-EDTA and $Eu^{3+}$-DTPA are evaluated.

• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.116-122
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• 2000

On the instrumented root canal wall, amorphous, irregular smear layer can be observed with Scanning Electron Microscope(SEM). The purpose of this study was to evaluate the effect of the presence or absence of smear layer on the adhesion of Staphylococcus aureus to the dentin of the root canal. Human incisors, extracted within 7 days, with no caries, no fracture, no calcification of canal, were selected. After cutting crown portion at cemento-enamel junction, root canal preparation was done by modified crown-down technique using Profile and Gates - Glidden Drill. During canal preparation, 10ml physiologic saline solution(group1&3) or 10ml 3.5% NaOCl(group2&4) was used as irrigation solution. And 10ml physiologic saline solution(group1&3) or 10ml 0.5M EDTA(group2&4) was applicated for final flush. After vertical sectioning and ethylene oxide gas sterilization, samples(group1&2) were immersed into BHIYHM broth inoculated with Staphylococcus aureus (ATCC 31153) and incubated for 3hrs at $37^{\circ}C$. All samples were prepared for and observed with SEM(JEOL JSM840S). The data were analyzed by Mann-Whitney rank sum test. The conclusions are as follows ; 1. Smear layer covers entire root canal surface after root canal preparation. 2. Smear layer has been removed away and the entrances of dentinal tubules have opened widely, when applying 0.5M EDTA and 3.5% NaOCl. 3. A significantly higher number of bacteria were adhered to the root canal dentin without smear layer(p<0.0001). 4. Smear layer produced during root canal preparation impedes bacterial adhesion and colonization to dentin matrix, therefore inhibits canal reinfection.

• Journal of the Korean Society of Groundwater Environment
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• v.1 no.2
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• pp.105-112
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• 1994

To investigate the migration behavior of contaminants in rocks. adsorption and diffusion experiments for Sr as a sorbing contaminant and for Cr-EDTA as a non-sorbing contaminant were carried out on granitic rocks. The Sr adsorption on separated minerals and crushed rocks tends to slightly increase with increasing pH. It also greatly decreases with the increase of ionic strength in NaCl solution. Among separated minerals, biotite and sericite have adsorbed much more amount of Sr than other rock-forming minerals, such as quartz, plagioclase, and potassic feldspar, because the specific surfaces and cation exchange capacities of phyllosilicates are generally much greater than those of the other rock-forming minerals. The intrinsic diffusion coefficients of Cr-EBTA for granitic rocks differ little from those of Sr. This indicates that they are independent of water-rock interactions. Experimental data show that the intrinsic diffusion coefficients are positively correlated with the porosities of the rocks. They are close to the theoretically predicted values, especially in pre-steady state diffusion region, with the increase of rock sample thickness.

• Korean Journal of Food Science and Technology
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• v.3 no.1
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• pp.48-51
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• 1971

The raw surf clam meat was pretreated with BHA, EDTA or $NaHSO_3$. The pretreated meat was chopped with chopper, and spread the chopped meat on nylon net, and then dehydrated with cabinet type hot air dryer. In the surf clam meat flake process, the pretreating and the copping steps prior to final dehydration improved the pigment retention and texture of the products. The chopping steps prior to dehydration reduced the dehydration time of surf clam meat. The BHA treatment prior to dehydration of mashed surf clam meat had an outstanding effect on the pigment retention during a process of dehydration and storage. The surf dam meat flakes reabsorbed water more rapidly about two times than the dehydrated natural surf clam meat products. The surf clam meat flakes stored for three months in the dark place showed less pigment loss than the exposed ones, and the former reabsorbed water more rapidly than the latter.

• Journal of the Korean Chemical Society
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• v.15 no.2
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• pp.49-54
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• 1971

It is shown that the impurities of Cu(II), Pb(II), Zn(II) and Ag(I) in Bismuth metal and the components of Pb(II), Zn(II) and Sn(IV) in Bismuth alloy are separated into their components from each other by elutions through $3.14cm^2{\times}10cm$ cation exchange resin, $Dowex\;50w\;{\times}\;8$ (100~200 mesh), column with the mixed solutions of HAc and NaAc as the eluents. The elution curve of Fe(III) has a long tailing and is not separated quantitatively from Bi(III). The eluents used for this separation are as follows; 1M HAc + 0.1M NaAc (pH 3.36) for Fe(III) and Bi (III). 0.3M HAc + 0.3M NaAc (pH 4.70) for Cu(II), Pb(II) and Zn(II). 0.5M HAc + 0.5M NaAc (pH4.70) for Ag(I) and Sn(IV). The analysis of cations eluted are carried out by spectrophotometry and EDTA titrimetry. Their recoveries are more than 99%.

• Korean Journal of Materials Research
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• v.4 no.2
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• pp.187-193
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• 1994

무전해 동도금액에서의 각종 안정제, 촉진제등의 첨가제에 따른 영향을 고찰하였다. 욕의 기본성분은 황산구리 10g/1, EDTA-2Na 40g/1, 포르말린 3ml/1, pH조절용 수산화나트륨 용액으로 조성하였고, 안정제, 도금촉진제 및 계면활성제의 첨가에 따른 분극곡선을 검토하여 도금욕의 경향을 검토한뒤 농도변화에 따른 도금속도를 측정하여 최적조건을 구하였다. 안정제는 $\alpha$, $\alpha$'-dipyridy1과 NaSCN을 혼합 사용하는 것이 좋았으며 촉진제로는 pyridine이 계면활성제로는 PEG 4000이 좋았다. 첨가량은 5mg/1이하의 미량이었으며 이후 첨가량이 증가함에 따라 증가함에 따라 도금속도는 직선적으로 감소하였다.

• Restorative Dentistry and Endodontics
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• v.7 no.1
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• pp.65-69
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• 1981

This study was conducted to evaluate the cleansing effect of RC-Prep (10% Urea-peroxide, 15% EDTA) on apical third of root canal. Thirty single rooted human teeth were divided into three groups, and ten canals in each group were all enlarged three sizes greater than their original diameter with K-type files and irrigated with each of three irrigants. The three used irrigants were RC-prep (Premier Co.) in combination with 3.5% Sodium hypochlorite, Normal saline, 3.5% Na OCL. In each group, one of three irrigants were used in conjunction with instrumentation as they would be during clinical condition. After final irrigation, the canals were dried with paper points and the teeth were split longitudinally. The cleanness of canal walls iii the apical region were examined with Scanning Electron Microscope. The following results were drawn. 1. The use of Rc-Prep in combination with 3.5% NaOCl showed more clean canal surface than the use of other two irrigants. 2. The canals used RC-Prep in combination with 3.5% NaOCl revealed remnants of pulp tissue and smeared layer, but the openings of dentinal tubules were relatively clean and wide. 3. There was no significant difference in the debridement effect of 3.5% NaOCl and Saline solution. 4. The use of Saline solution showed great amount of remnants of pulp tissue which couldn't find in the use of 3.5% NaOCl.

• The Korean Journal of Physiology and Pharmacology
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• v.8 no.5
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• pp.259-264
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• 2004

Cytolysin produced by Vibrio vulnificus has been incriminated as one of the important virulence determinants in V. vulnificus infection. Ion selectivity of cytolysin-induced pores was examined in a CPAE cell, a cell line of pulmonary endothelial cell, using inside-out patch clamp techniques. In symmetrical NaCl concentration (140 mM), intracellular or extracellular application of cytolysin formed ion-permeable pores with a single channel conductance of $37.5{\pm}4.0$ pS. The pore currents were consistently maintained after washout of cytolysin. Replacement of $Na^+$ in bath solution with monovalent ions $(K^+,\;Cs^+\;or\;TEA^+)$ or with divalent ions $(Mg^{2+},\;Ca^{2+})$ did not affect the pore currents. When the NaCl concentration in bath solution was lowered from 140 to 60 and 20 mM, the reversal potential shifted from 0 to -11.8 and -28.2 mV, respectively. The relative permeability of the cytolysin pores to anions measured at $-40\;mV\;was\;Cl^-\;=\;NO_2^-\;{\geq}\;Br^-\;=\;I^-\;> \;SCN^-\;>\;acetate^-\;>\;isethionate^-\;>\;ascorbic acid^-\;>\;EDTA^{2-},$ in descending order. The cytolysin-induced pore current was blocked by $CI^-$ channel blockers or nucleotides. These results indicate that V. vulnificus cytolysin forms anion-selective pores in CPAE cells.