• 자원환경지질
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• 제53권4호
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• pp.337-346
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• 2020

본 연구는 국내 휴·폐금속광산 주변의 수은이 함유된 광물찌꺼기 처리 또는 수은으로 오염된 고형물질(토양, 퇴적물 등)의 정화를 위한 세척공법 적용성 평가를 위해 수행되었다. 이를 위해 수은을 함유한 광물찌꺼기에 대하여 입도분석과 단계별 추출시험을 실시하여 물리·화학적 특성을 고찰하고, 세척공법 적용성 평가를 위해 염산(HCl), 질산(HNO₃), 요오드화칼륨(KI) 및 티오황산나트륨(Na₂S₂O₃) 세척액을 활용한 실험실 규모의 세척시험을 실시하였다. 광물찌꺼기 시료의 입도분포는 #40 이하로 집중되며, #200 이하의 입도가 가장 높은 비율을 차지하였다. 단계별 추출시험 결과, 광물찌꺼기에는 원소 수은이 69.12%로 가장 높은 비율을 차지하고 있으며, 강한 결합 형태가 15.25%, 유기결합 및 잔류 형태 형태가 11.97%의 비율을 각각 차지하고 있었다. 광물찌꺼기에 함유된 수은의 세척 적용성을 검토한 결과, 질산(HNO₃)과 티오황산나트륨(Na₂S₂O₃)의 경우, 세척공법 적용성이 낮은 것으로 분석되었다. 염산(HCl)의 경우 #200 이상의 입도에서 수은 제거가 가능한 것으로 분석되어 물리적 선별 공정이 필요한 것으로 판단되었다. 요오드화칼륨(KI)은 모든 농도와 입도에서 우수한 화학적 세척효율 보였다. 특히, 미세입자에서도 우수한 수은 제거 효율이 확인되어 세척공법 적용성이 가장 높은 것으로 평가되었다.

• 대한소아치과학회지
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• 제49권4호
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• pp.497-504
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• 2022

연구의 목적은 2종의 액상형 불소 제재의 Streptococcus mutans에 대한 항균 효과를 평가하는 것이다. 불화은(AgF, 1제)과 요오드화칼륨(KI, 2제)로 구성된 Riva star aqua^TM (SDI)와 Fluor protector^® (FP; Ivoclar Vivadent)를 실험군에 사용하였다. 실험군은 4개의 군으로 구분하였다: AgF, KI, AgF + KI, FP. 양성 대조군(PC)에는 ampicillin을 사용하였고, 음성 대조군(NC)에는 아무런 처치도 시행하지 않았다. 각 군을 사용한 용액의 양에 따라 30과 50 µL로 다시 분류하였고, 평판 도말된 S. mutans에 적용하였다. 이후 억제대의 직경을 측정하였다. PC와 AgF는 모든 재료에 비해 큰 직경을 보였고(p < 0.05), AgF는 50 µL군에서 PC와 유의한 차이가 없었다(p > 0.05). FP는 30 µL군에서 AgF + KI 보다 큰 직경을 보였다(p = 0.009). KI는 NC와 유의한 차이가 없었다(p > 0.05). 불화은은 S. mutans에 대해 ampicillin과 유사한 항균효과를 보였으며, FP보다 더 뛰어남을 확인 하였다.

• 대한화학회지
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• 제27권3호
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• pp.178-182
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• 1983

비양성자성 극성용매인 탄산에틸렌과 아세톤과의 혼합용매에서 NaI, KI,$ NH_4I,\;(CH_3)_4NI,\;(C_2H_5)_4NI$, NaPic(Pic:피크린산이온), KPic, $(C_4H_9)_4NB(ph)_4$의 전기전도도를 $25{\circ}C$에서 측정하였다. 한계당량전도도를 Fuoss-Kraus식에 의하여 구한 결과 그 크기의 순위는 혼합용매의 성분비에 관계없이 $(C_4H_9)_4NB(ph)_4이었다. 이 전해질들의 해리상수로 부터 탄산에틸렌-아세톤 혼합용매는 이들에 대하여 좋은 이온화용매임을 알 수 있었다. 한계이온당량 전도도의 순위, $Na^+는 용매화수의 역순위와 일치하였다. Nightingale 방법에 의하여 구한 각 이온의 유효 용매화반지름에 의하면 피크린산이온은 용매화되어 있지 않으며, 요오드화이온은 탄산에틸렌-아세톤 혼합용매에서 상당히 용매화되어 있음을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제10권4호
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• pp.382-388
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• 1989

The approximate rates and stoichiometry of the reaction of excess potassium tri-sec-butylborohydride ($K_s-Bu_3BH$) with selected organic compounds containing representative functional groups were determined under the standard conditions (0$^{\circ}C$, THF) in order to define the characteristics of the reagent for selective reductions. Primary alcohols evolve hydrogen in 1 h, but secondary and tertiary alcohols and amines are inert to this reagent. On the other hand, phenols and thiols evolve hydrogen rapidly. Aldehydes and ketones are reduced rapidly and quantitatively to the corresponding alcohols. Reduction of norcamphor gives 99.3% endo- and 0.7% exo-isomer of norboneols. The reagent rapidly reduces cinnamaldehyde to the cinamyl alcohol stage and shows no further uptake of hydride. p-Benzoquinone takes up one hydride rapidly with 0.32 equiv hydrogen evolution and anthraquinone is cleanly reduced to the 9,10-dihydoxyanthracene stage. Carboxylic acids liberate hydrogen rapidly and quantitatively, however further reduction does not occur. Anhydrides utilize 2 equiv of hydride and acyl chlorides are reduced to the corresponding alcohols rapidly. Lactones are reduced to the diol stage rapidly, whereas esters are reduced moderately (3-6 h). Terminal epoxides are rapidly reduced to the more substituted alcohols, but internal epoxides are reduced slowly. Primary and tertiary amides are inert to this reagent and nitriles are reduced very slowly. 1-Nitropropane evolves hydrogen rapidly without reduction and nitrobenzene is reduced to the azoxybenzene stage, whereas azobenzene and azoxybenzene are inert. Cyclohexanone oxime evolves hydrogen without reduction. Phenyl isocyanate utilizes 1 equiv of hydride to proceed to formanilide stage. Pyridine and quinoline are reduced slowly, however pyridine N-oxide takes up 1.5 equiv of hydride in 1 hr. Disulfides are rapidly reduced to the thiol stage, whereas sulfide, sulfoxide, sulfonic acid and sulfone are practically inert to this reagent. Primary alkyl bromide and iodide are reduced rapidly, but primary alkyl chloride, cyclohexyl bromide and cyclohexyl tosylate are reduced slowly.

• Restorative Dentistry and Endodontics
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• 제44권1호
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• pp.4.1-4.10
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• 2019

Objectives: Biofilm formation is critical to dental caries initiation and development. The aim of this study was to investigate the effects of nicotine exposure on Streptococcus mutans (S. mutans) biofilm formation concomitantly with the inhibitory effects of sodium chloride (NaCl), potassium chloride (KCl) and potassium iodide (KI) salts. This study examined bacterial growth with varying concentrations of NaCl, KCl, and KI salts and nicotine levels consistent with primary levels of nicotine exposure. Materials and Methods: A preliminary screening experiment was performed to investigate the appropriate concentrations of NaCl, KCl, and KI to use with nicotine. With the data, a S. mutans biofilm growth assay was conducted using nicotine (0-32 mg/mL) in Tryptic Soy broth supplemented with 1% sucrose with and without 0.45 M of NaCl, 0.23 M of KCl, and 0.113 M of KI. The biofilm was stained with crystal violet dye and the absorbance measured to determine biofilm formation. Results: The presence of 0.45 M of NaCl, 0.23 M of KCl, and 0.113 M of KI significantly inhibited (p < 0.05) nicotine-induced S. mutans biofilm formation by 52%, 79.7%, and 64.1%, respectively. Conclusions: The results provide additional evidence regarding the biofilm-enhancing effects of nicotine and demonstrate the inhibitory influence of these salts in reducing the nicotine-induced biofilm formation. A short-term exposure to these salts may inhibit S. mutans biofilm formation.

• Fibers and Polymers
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• 제7권4호
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• pp.333-338
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• 2006

Silk fibroin (SF) fiber from the Antheraea pernyi silkworm was treated with a 1.23 N iodine-potassium iodide ($I_2-KI$) aqueous solution, and the structure and physical properties were investigated to clarify the effects of the iodine treatment. The noticeably high weight gain value of SF fiber, about 25 wt% was attributed to the absorption of polyiodide ions in the form of $I_3{^-}\;and\;I_5{^-}$. Fourier transform infrared spectroscopy and X-ray diffraction measurements suggested that polyiodide ions mainly entered the amorphous region. In addition, a new sharp reflection on the meridional direction, corresponding to a period of $7.0{\AA}$, was observed and indicated the possibility of the formation of mesophase structure of ${\beta}$-conformation chains. Dynamic viscoelastic measurements showed that the damping tan ${\delta}$ peak at $270^{\circ}C$ gradually shifted to lower temperature in the iodinated SF fibers, suggesting an enhancement of the molecular motion of the fibroin chains induced by the presence of polyiodide ions. With heating above $254^{\circ}C$, the iodine component introduced intermolecular cross-linking of SF, and the melt flow of the sample was inhibited. The thermal decomposition stability of fibroin molecules was greatly enhanced by iodine treatment.

• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.3923-3927
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• 2011

A noble method for pre-concentration and speciation of ultra trace As (III) and As (V) in urine and whole blood samples based on dispersive liquid-liquid microextraction (DLLME) has been developed. In this method, As (III) was complexed with ammonium pyrrolidine dithiocarbamate at pH = 4 and Then, As (III) was extracted into the ionic liquid (IL). Finally, As (III) was back-extracted from the IL with hydrochloric acid (HCl) and its concentration was determined by flow injection coupled with hydride generation atomic absorption spectrometry (FI-HGAAS). Total amount of arsenic was determined by reducing As (V) to As (III) with potassium iodide (KI) and ascorbic acid in HCl solution and then, As (V) was calculated by the subtracting the total arsenic and As (III) content. Under the optimum conditions, for 5-15 mL of blood and urine samples, the detection limit ($3{\sigma}$) and linear range were achieved 5 ng $L^{-1}$ and 0.02-10 ${\mu}g\;L^{-1}$, respectively. The method was applied successfully to the speciation and determination of As (III) and As (V) in biological samples of multiple sclerosis patients with suitable precision results (RSD < 5%). Validation of the methodology was performed by the standard reference material (CRM).

• 대한임상독성학회지
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• 제9권2호
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• pp.39-48
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• 2011

In mass casualty situation due to radiological accidents, it is important to start aggressive management with rapid triage decisions. External contamination needs immediate decontamination and internal contamination should be treated with special expertise and equipment to prevent the rapid uptake of radionuclides by target organs. Acute radiation syndrome shows a sequence of events that varies with the severity of the exposure. More severe exposures generally lead to more rapid onset of symptoms and severe clinical findings. After the massive exposure, various systems of the body reflect their severe damages that can lead to death within hours or up to several months. The disease progression has classically been divided into four stages: prodromal, latent, manifest illness, and recovery or death. Three characteristic clusters of symptoms including the hematopoietic syndrome, the gastrointestinal syndrome and the cerebrovascular syndrome are all associated with the acute radiation syndrome. The standard medical management of the patients with a potentially survivable radiation exposure includes good medical, surgical and supportive measures. Specific treatment with cytokines and bone marrow transplantation should be considered. The management of internal contamination is much the same as the treatment of poisoning. The standard decontamination should be applied to reduce uptake, and the chelating agents can be administered to enhance the clearance of radioisotopes. Radioactive iodine ($^{131}I$) as one of the nuclear fission products can increase the incidence of thyroid cancer in children. Potential benefit of potassium iodide prophylaxis is greater especially in neonates, infants and small children.

• 한국응용곤충학회지
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• 제21권1호
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• pp.19-22
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• 1982

잎도열병의 발생은 잎도열병병반수조사 4일전까지의 2개반순의 분생포자비산수와 고도의 정의 상관이 있었고 이삭도열병발생은 진흥품종에서 출수기 분생포자비산수와 정의 상관관계였다. 수잉기에 있어서 잎도열병의 병엽수와 이삭도열병발생은 고도의 정의 상관, 지엽의 규화도와는 부의 상관이 있었다. I-KI법은 30분이내에 도열병균 침입에 의한 감염부위를 알 수 있어 잎도열병의 초발은 4일전에 예찰이 가능하였으며 I-KI법과 잎도열병발생과의 양적인 관계를 구명하는 것도 가능한 것으로 나타났다.

• Nuclear Engineering and Technology
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• 제52권8호
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• pp.1826-1833
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• 2020

Administration of stable iodine has been considered a best measure to protect the thyroid from internal irradiation by radioiodine intake, and its efficacy on thyroid protection has been quantitatively evaluated in several simulation studies on the basis of simple iodine biokinetic models (i.e., three-compartment model). However, the new iodine biokinetic model adopted by the International Commission on Radiological Protection interprets and expresses the thyroid blocking phenomenon differently. Therefore, in this study, the new model was analyzed in terms of thyroid blocking and implemented to reassess the protective effects and to produce dosimetric data. The biokinetic model calculation was performed using computation modules developed by authors, and the results were compared with those of experimental data and prior simulation studies. The new model predicted protective effects that were generally consistent with those of experimental data, except for those in the range of stable iodine administration -72 h before radioiodine exposure. Additionally, the dosimetric data calculated in this study demonstrates a critical limitation of the three-compartment model in predicting bioassay functions, and indicated that dose assessment 1 d after exposure would result in a similar dose estimate irrespective of the administration time of stable iodine.