• Restorative Dentistry and Endodontics
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• 제28권1호
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• pp.50-56
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• 2003

The purpose of this study was to evaluate the effects of EDTA and pulsed Nd :YAG laser on apical leak-age of canal obturation. Forty-eight single-rooted teeth were used in this study. The teeth were instrumented up to a size 40 K-file and irrigated with 2.5% NaOCl between each fie size. And the teeth were divided into 4 groups. In group A, the root canals were irrigated with a final flush of 5ml 2.5% NaOCl as a control group. The teeth in group B were irrigated with a final flush of 5ml 17% EDTA. The teeth in group C and D were irradiated by pulsed Nd：YAG laser(laser parameters were set at 1W, 100mJ, 10Hz, and 2W, 100mJ, 20Hz respectively). The results were as follows : 1. Apical leakage was observed in 50% of samples in group A, 30% of samples in group B, 20% of samples in group C, and 10% of samples in group D. 2. The teeth in group B had less leakage than group A, but there was no statistically significant differences(p＞0.05). 3. The teeth in group C, D had less leakage than group A, and there was statistically significant differences(p＜0.05). 4. The teeth in group C, D had less leakage than group B, but there was no statistically significant differences(p＞0.05). 5. There was no significant differences in apical leakage between group C and group D(p＞0.05).

• Journal of Microbiology and Biotechnology
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• 제17권2호
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• pp.313-319
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• 2007

The nutritional medium requirement for biosurfactant production by Bacillus licheniformis K51 was optimized. The important medium components, identified by the initial screening method of Plackett-Burman, were $H_3PO_4,\;CaCl_2,H_3BO_3$, and Na-EDTA. Box-Behnken response surface methodology was applied to further optimize biosurfactant production. The optimal concentrations for higher production of biosurfactants were (g/l): glucose, $1.1;NaNO_3,\;4.4;MgSO_4{\cdot}7H_2O,\;0.8;KCl,\;0.4;CaCl_2,\;0.27;H_3PO_4,\;1.0ml/l;\;and\;trace elements\;(mg/l):H_3BO_3,\;0.25;CuSO_4,\;0.6;MnSO_4,\;2.2;Na_{2}MoO_4,\;0.5;ZnSO_4,\;6.0;FeSO_4,\;8.0;CoCL_2,\;1.0;$ and Na-EDTA, 30.0. Using this statistical optimization method, the relative biosurfactant yield as critical micelle dilution (CMD) was increased from $10{\times}\;to\;105{\times}$, which is ten times higher than the non-optimized rich medium.

• 생명과학회지
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• 제8권2호
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• pp.197-202
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• 1998

효모를 먹이로 하는 filter-feeder들의 소화력을 높이고자, algae의 대용물로서 가치가 있는 Kluyveromuces fragilis효모를 화학적 처리방법에 의해 세포벽을 바괴시켰다. 화학적 처리방법의 최적조건은 0.2 M Tris-buffer에 용해시켜 만든 1M 의 $Na_2EDTA$와 0.3 M의 2-mercaptoethanol을 처리한 후 $30{\circ}C$배양기에서 1시간 배양하는 조건에서 얻어졌다. 이때, 약 30%의 protoplast yeast를 실시함으로써, 그 생성률을 약 2배이상 올릴 수 있었다.

• 한국축산식품학회지
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• 제36권6호
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• pp.769-778
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• 2016

In this study, we improved the eggshell-membrane separation process by separating the shell and membrane with EDTA solution, evaluating effects of three different extraction solutions (acetic acid, EDTA, and phosphate solution), and co-purifying multiple eggshell proteins with two successive ion-exchange chromatography procedures (CM Sepharose Fast Flow and DEAE Sepharose Fast Flow). The recovery and residual rates of eggshell and membrane separated by the modified method with added EDTA solution were 93.88%, 91.15% and 1.01%, 2.87%, respectively. Ovocleidin-116 (OC-116) and ovocalyxin-36 (OCX-36) were obtained by loading 50 mM Na-Hepes, pH 7.5, 2 mM DTT and 350 mM NaCl buffer onto the DEAE-FF column at a flow rate of 1 mL/min, ovocleidin-17 (OC-17) was obtained by loading 100 mM NaCl, 50 mM Tris, pH 8.0 on the CM-FF column at a flow rate of 0.5 mL/min. The purities of OCX-36, OC-17 and OC-116 were 96.82%, 80.15% and 73.22%, and the recovery rates were 55.27%, 53.38% and 36.34%, respectively. Antibacterial activity test suggested that phosphate solution extract exhibited significantly higher activity against the tested bacterial strains than the acetic acid or EDTA extract, probably due to more types of proteins in the extract. These results demonstrate that this separation method is feasible and efficient.

• Journal of Periodontal and Implant Science
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• 제29권1호
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• pp.51-63
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• 1999

Exposure of the root surface due to gingival recession after periodontal surgery, elicit pain response when exposed to mechanical, heat, chemical or osmotic irritation. Especially patients treated with periodontal surgery, show high frequency. There have been reports that the 1 out of 7 patients complains of dentinal hypersensitivity. There have been many studies on the clinical effects of various materials on the treatment of dentinal hypersensitivity. The purposes of this study were to evaluate the effect of sodium chloride and potassium oxalate and to observe the relationship between the dentinal hypersensitivity and surface characteristics such as dentinal tubule size and number. This study included 20 teeth which were scheduled for extraction and had no pulpal disease. These teeth were divided into Root planing group, EDTA group, NaCl group and Oxalate group. Dentinal hypersensitivity is measured by tactile, pressured air and cold water using NRS (Numerical Rating Scales). Teeth were extracted under local anesthesia and each specimen was sectioned to a size about 3 X 5 mm and was examined under the scanning electron microscope (X2,000) The results were as follows, 1. The EDTA group exhibited significantly increased dentinal hypersensitivity comparing with the other groups. 2. The NaCl and Oxalate groups showed significantly reduced dentinal hypersensitivity comparing with the EDTA group. 3. As a method for dentinal hypersensitivity measurement, it was presumed thet tactile sensitivity test was not sensitive method but air blast test and cold water test were adequate method. 4. In a SEM study, the root planing group exhibited amorphous smear layer and showed no dentinal tubule orifice, but the EDTA group showed the large number of dentinal tubules. On the other hand, the NaCl and Oxalate groups did not show exposed dentinal tubules. The NaCl group showed more rough root surface than the EDTA group, and the Oxalate group showed many participates to be presumed as calcium oxalate particle. As the results from this study, root planing couldn't expose the dentinal tubule and NaCl and potassium oxalate occluded exposed dentinal tubule effectively. Dentinal hypersensitivity has close relationship with the exposure of dentinal tubules, especially with it's size and number.

• 한국물환경학회지
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• 제21권1호
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• pp.66-72
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• 2005

Effect of the pH, molar ratio of Cu(II)/EDTA, concentration of Cu(II)-EDTA and ionic strength on the photocatalytic oxidation(PCO) of Cu(II)-EDTA in solar light was studied in this work. Experimental results in this work were compared with previous results obtained with UV-lamp. In the kinetics, Cu(II)-EDTA decomposition was favorable below neutral pH. The removal of Cu(II) and DOC was favorable as $TiO_2$ dosage increased. The initial rate for the decomplexation of Cu(II)-EDTA linearly increased as the concentration of Cu(II)-EDTA increased. The removal of Cu(II) and DOC was not much affected by variation of ionic strength with $NaClO_4$ as a background ion while much reduction was observed in the presence of background ions having higher formal charges. The removal trend of Cu(II) and DOC with variation of ionic strength and concentration of Cu(II)-EDTA in solar light was similar with that in UV light. Variation of the molar ratio of Cu(II)/EDTA showed a negligible effect on the removal of both Cu(II) and DOC. However, removal of both Cu(II) and DOC was two-times greater than that previous results obtained with UV light.

• 한국토양비료학회지
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• 제5권2호
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• pp.59-64
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• 1972

담수상태하(湛水狀態下)에서 수종(數種) 규산물질(珪酸物質)의 입도별(粒度別) 토양산도교정능력(土壤酸度矯正能力)을 시기별(時期別)로 비교(比較)하고 EDTA 용액(溶液)과 NaOAc 용액(溶液) 침출(浸出)알카리분(分)이 이들 물질(物質)의 토양산도교정능력(壤酸度矯正能力)을 가늠할 수 있는지 검토(檢討)한 결과(結果) 1. 용성인비(熔成燐肥)는 pH5.5에 이르는 기간(期間)이 60일(日) 보다 작은 입자(粒子)는 20일(日), 40~48일(日)에서는 34일(日), 20~25일(日)은 84일(日)이 소요(所要)됐으며 같은 크기의 석회석립자(石灰石粒子)의 교정산도(矯正酸度)보다 pH 치(値)가 약 1.0~0.5 정도(程度) 낮았다. 2. 광재(鑛滓) I(Basic reduction furnace slag)는 100보다 작은 입자(粒子)는 pH5.5까지 교정(矯正)되나 이보다 큰 입자(粒子)는 pH $4.5{\pm}0.5$ 범위(範圍)에서 머물고, 규회석(珪灰石)은 25일(日) 보다 큰 입자(粒子)는 효과가 없고 40일(日)보다 작은 입자(粒子)는 pH 4.5~5.0 까지 밖에 미치지 못하며, 광재 II(Blast furnace slag)는 입도(粒度)의 크기에 큰 영향(影響)을 받지 않고 매우 미약(微弱)한 효과를 보였다. 3. 각재료(各材料) 및 입도별(粒度別) 교정산도(矯正酸度)와 EDTA 용액(溶液) 및 NaOAc 용액(溶液) 침출(浸出)알카리분(分)과의 관계(關係)는 NaOAc 용액(溶液) 침출(浸出)알카리분(分)이 EDTA 용액침출(溶液浸出)알카리분(分)보다 토양교정산도(土壤矯正酸度)와 더욱 밀접(密接)한 관계(關係)를 나타내며, 시기별(時期別)로 NaOAc 침출(浸出)알카리분(分)은 담수후(湛水後) 8일(日), EDTA 침출(浸出)알카리분(分)은 16일(日) 이후(以後)에 상관계수(相關係數)가 고정(固定)되었다.

• Restorative Dentistry and Endodontics
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• 제40권3호
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• pp.195-201
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• 2015

Objectives: The use of chitosan nanoparticles (CNPs) in endodontics is of interest due to their antibiofilm properties. This study was to investigate the ability of bioactive CNPs to remove the smear layer and inhibit bacterial recolonization on dentin. Materials and Methods: One hundred bovine dentin sections were divided into five groups (n = 20 per group) according to the treatment. The irrigating solutions used were 2.5% sodium hypochlorite (NaOCl) for 20 min, 17% ethylenediaminetetraacetic acid (EDTA) for 3 min and 1.29 mg/mL CNPs for 3 min. The samples were irrigated with either distilled water (control), NaOCl, NaOCl-EDTA, NaOCl-EDTA-CNPs or NaOCl-CNPs. After the treatment, half of the samples (n = 50) were used to assess the chelating effect of the solutions using portable scanning electronic microscopy, while the other half (n = 50) were infected intra-orally to examine the post-treatment bacterial biofilm forming capacity. The biovolume and cellular viability of the biofilms were analysed under confocal laser scanning microscopy. The Kappa test was performed for examiner calibration, and the non-parametric Kruskal-Wallis and Dunn tests (p < 0.05) were used for comparisons among the groups. Results: The smear layer was significantly reduced in all of the groups except the control and NaOCl groups (p < 0.05). The CNPs-treated samples were able to resist biofilm formation significantly better than other treatment groups (p < 0.05). Conclusions: CNPs could be used as a final irrigant during root canal treatment with the dual benefit of removing the smear layer and inhibiting bacterial recolonization on root dentin.

• 한국미생물·생명공학회지
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• 제31권3호
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• pp.211-215
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• 2003

고함량 RMh 효모인 Saccharomyces cerevisiae MTY62를 당밀과 com steep liquor를 공급하는 유가배양에서, 세포농도는 45g-DCW/L 이하, RNA 함량은 140mg/g-cell 로 얻어졌다. 이는 균체증식과 RMh축적에 당밀 내에 존재하는 저해물질 때문으로 생각되어 이를 제거하기 위해 다양한 당밀 전처리제의 효과를 조사하였다. 당밀로부터 금속이온 제거 효과는 Na2HPO4와 EDTA를 혼합 처리했을 때 $Ca^{++}$ 는 90% 이상 $Cu^{++}$ 는 약 80% 제거하는 결과를 나타내었고, Na2HPO4와 EDTA, IonClear BigBead 등의 3가지를 혼합 처리했을 때는 $Ca^{++}$ , $Cu^{++}$ 둘 다 90% 이상 제거되는 결과를 나타내었다. Na2HPO4+EDTA처리 당밀의 경우세포내 invertase활성을 크게 증가시켰다. 전처리 당밀로 회분배양한 결과, 세포농도는 18.6g-DCW/L, RNA농도는 3127mg/l, 최대비증식속도($\mu_{max}$ )는 0.459 $h^{-1}$ , 환원당 비소모속도(g-sugar/g-cell$.$h)는 1.28로,대조구에 비해 각각 10%, 17%, 47%, 36%로 증가한 값을 보였다.

• 한국수정란이식학회지
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• 제8권2호
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• pp.75-82
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• 1993

To investigate the effect of EDTA on the in vitro development of blastomeres isolated from 2, 4, and 8-cell embryos(termed 1 /2, 1 /4 and 1 /8 blastomeres, respectively) of ICR strain mice, those were cultured in vitro in 35 mm culture dishes containing NaHCO$_3$-BMOC-3 medium supplemented with 10, 50, 100, or 500 $\mu$M of EDTA at 37$^{\circ}C$ for 72hrs. under the atmosphere of 5% $CO_2$and 95% air. EDTA supplementation of 10, 50, or 100 $\mu$M to medium significantly(P<0.01) increased blastocyst formation rate compared with controls in 1 /2(58.3, 63.7, and 61.3% vs 21.6%), 1 /4(54.7, 57.5 and 62.2% vs. 2L3%), and 1 /8 blastomeres(46.2, 48.7, and 57.7% vs. 19.1%). Whereas, it was significantly(P<0.01) decreased to 4.5, 2.3, and 2.0% for 1 /2, 1 /4 and 1 /8 blastomeres, respectively by the EDTA supplementation of 500 M Both the nuclear number(P<0.05) and diameter of blastocysts(P<0.01) developed from balstomeres were significantly affected by the origin of blastomeres. The nuclear number of blastocysrs developed from 1/2, 1/4, and 1/8 blastomeres ranged 28.3i1.3, 24.18i1.2, and 19.84$\pm$0.9, respectively. And the diameter of those blastocysts was 87.2$\pm$1.1, 56.4$\pm$0.9, and 39.2$\geq$0.8 $\mu$M, respectively.