• 월간산업보건
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• s.84
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• pp.31-33
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• 1995

입에서 금속성 입맛을 동반하여 심한 위장관계 증상(예, 혈변, 복통, 오심, 구토)과 상부위장관출혈이 있으면 중금속 중독이 있음을 시사한다. 중금속은 유기형태와 무기형태 모두 유독함을 기역해야 한다. 혈액, 소변, 그리고 특히 모발내의 레벨이 급인성 중독을 정확하게 반영하지 않은 경우가 종종 있다. 중금속 중독이 된 많은 환자들이 킬레이션 치료(chelation therapy)에 효과가 있다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.42.2-42.2
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• 2009

인체의 치아 및 뼈는 무기질 성분과 단백질로 구성되어 있다. 생체세라믹스의 일종인 수산화아파타이트(Hydroxyapatite, HA; $Ca_{10}(PO_4)_6(OH)_2$)는 결정학적, 화학적으로뼈의 무기질 성분과 거의 유사하여 실제 체내에 들어가면 주위 뼈와 화학적 반응을 하여 단단한 결합을 이루는 생체활성(bioactive)을 가진 것으로 알려져 있다. 또한, 인산삼칼슘(Tri-Calcium Phosphate, TCP; $Ca_3(PO_4)_2$)은 체내에 이식 시 체액에 용해되어 신생골을 유도하는 생체흡수성(bioresorbable) 세라믹스로 알려져 있다. 상기 2종류를 포함한 인산칼슘계 화합물은 우수한 생체친화성에도 불구하고 역학 특성이 낮아, 하중을 거의 받지 않는 분야에만 사용되고 있는 실정이며, 하중을받는 분야(load-bearing part)에 적용하기 위해서는 고강도/고인성의 세라믹스와의 micro-composite이나 인산칼슘계화합물을 금속 표면에 코팅한 macro-composite의 형태로 사용되고 있다. 하중을 거의 받지 않는 분야, 예를 들어 치아 결손부를 보충할 dental shot과 같은 인산칼슘계 다공질 골충전재의 경우에도 취급 시 잘게 파손되는 문제점이 있어 치과의사들이 어려움을 호소하고 있는 실정이다. 본 연구에서는 HA, TCP의 역학특성을 증진시키고자 소결 공정 제어를 통하여 미세조직을 변화시켰으며, 미세조직 변화에 따른 세포반응성을 골포세포주를 이용하여 평가하였다.

• Journal of Environmental Impact Assessment
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• v.32 no.5
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• pp.353-362
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• 2023

TOC, which can measure more than 90% of organic substances, can be measured quickly and easily,replacing BOD and COD, which were indicators of organic pollutants. According to water quality pollution control standards, when measuring TOC, if the inorganic carbon ratio in the sample is over 50%, the NPOC (Non-Purgeable Organic Carbon) method should be used. If volatile organic compounds (VOCs) are present at a certain concentration, the TC-IC (subtracting inorganic carbon from total carbon) method should be used. To validate the limitations of these analytical conditions, experiments were conducted by varying the ratio of TOC to IC in purified water and measuring the concentration of TOC in test solutions. The results showed no significant difference between the TC-IC method and the NPOC method. When measuring samples with added VOC standard solutions, it was observed that the carbon loss due to purging was not significant when using the NPOC method. Therefore, it is concluded that the choice of analytical method does not lead to significant differences when VOCs are present in the sample. To account for potential variations in results based on water quality pollution control standards and regulations regarding the approval and testing of environmental measurement devices, a comparison of field sample concentration values was made using two widely used types of TOC analyzers in Korea. The results showed variations of 0.02 to 0.83 mg/L between methods depending on the manufacturer, highlighting the need for caution when selecting an instrument.

• Journal of Adhesion and Interface
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• v.14 no.1
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• pp.28-35
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• 2013

In this study, we produced heat-shield coating materials using surface-treated Ga-doped ZnO (GZO) and investigated the dispersity of particle, visible light transmittance, ultraviolet light cut off, infrared light cut-off, heat-shielding property by surface-treating compounds and treatment conditions. In the case of using IPA or acryl binder for heat-shield coating, the dispersity of inorganic oxide particles was poor but in the case of using surface-treated inorganic oxide particles by hybrid compound having urethane (urea) group, acryl group and silica, dispersity of particle, visible light transmittance and haze were improved. We used the measurement kit and sunlamp for measuring heat-shielding property and confirmed that the internal temperature of the measurement kit using heat-shield film was lower more than $4.8^{\circ}C$ in comparison with using PET film for itself.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.15 no.2
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• pp.86-91
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• 2005

The layered structure of organic-inorganic perovskite hybrids, $(C_nH_{2n+1}NH_3)_2CuC1_4$ (n = 6, 8, 10, 12) have synthesized. In $(C_nH_{2n+1}NH_3)_2CuC1_4$ compounds, the long-chain protonated alkylammonium ions as tilted bilayer type are inserted into perovskite-type layers of corner sharing $CuCl_6$ octahedron. Three solid phases have been characterized in the perovskite layered compound $(C_nH_{2n+1}NH_3)_2CuC1_4$ using HT-XRD and DSC. The $(C_nH_{2n+1}NH_3)_2CuC1_4$ compounds shows solid-solid phase transitions with stepwise increasing of the layer distance. Three different structures are explained by the conformational change of the long-chain protonated alkylammonium ions.

• Journal of the Korean Chemical Society
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• v.41 no.8
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• pp.392-398
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• 1997

A method of selective determination of inorganic and organic mercury compounds has been described. The $CHCl_3$ solution of a high molecular quaternary alkylammonium salt, Aliquat 336 was used for the simultaneous preconcentration of both inorganic, $Hg^{2+}$ as its thiocyanate complex, and organic mercury compounds, $CH_3HgCl$ and $C_2H_3O_2$ $HgC_6H_5$ by extraction from their aqueous solution. Selective separation of the inorganic mercury from the extract was followed by stripping with 3 M $HClO_4 $ solution for the subsequent determination by CVAAS. Organic mercury was also determined by CVAAS after removal of $CHCl_3solvent$ from the extract and decomposition of the residue with 4% $KMnO_4 $-1 MH_2$S0_4$. The mixtures of inorganic and organic mercury compounds contained 1.0 $\mug$ as Hg in 50 mL of sample solution(0.02 ${\mu}gHg/mL$) were analysed within ${\pm}6%$ by absolute errors.

• KSBB Journal
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• v.17 no.2
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• pp.158-161
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• 2002

In this study, a prototype fiber-optic biosensor was fabricated using the inhibition of enzyme reaction by organophosphorus compounds to detect organophosphorus compounds, which is nervous toxic material an? is used as chemical weapon and pesticide. Enzyme, substrate, and inhibitor for enzyme reaction were acetylcholinesterase (key enzyme in nervous cell), acetylthiocholine iodide, and paraoxon (a kind of organophosphorus compounds), respectively. The detection principle of sensor is the detection of enzyme reaction inhibited by organophosphorus compounds by the quantitative measurement of acetic acid, which was achieved by absorbance measurement using litmus solution that maximum absorbance band is changed by pH. To fabricate prototype fiber-optic biosensor, high bright LED and photodiode was used as light source and light intensity detector, respectively. From the experimental results using a prototype biosensor, the linear change of sensor signal was obtained in a range of 0-2 ppm inhibitor concentrations. From these results, it was verified that the quantitative measurement of organophosphorus compounds could be achieved fast (within 2 minutes) and accurately by a prototype fiber-optic biosensor.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.492-500
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• 2015

Our previous report demonstrated successful isolation of soil-borne bacteria that suppressed the potential of Rhizoctonia solani AG2-2 (IV) causing turfgrass large patch disease when applied to Korean lawngrass (Zoysia japonica). The current study aimed to uncover the mechanisms of this antagonism of Rhizoctonia solani and to define culture conditions for the isolated microbes. We found that two Bacillus isolates, I-009 and FRIN-001-1 strains, produced cellulase and siderophore, but not chitinase, while the Pseudomonas YPIN-022 strain was found to release only siderophore, implying that three antagonistic bacteria commonly interrupt Fe uptake by the large patch pathogen. The I-009 and FRIN-001-1 isolates grew best at 35 and $30^{\circ}C$ in growth medium of pH 5 to 8 for 32 and 28 h, respectively, while optimum growth for the YPIN-022 strain was found at $35^{\circ}C$ at pH 5 to 9 for 24 h. Good growth of I-009 and YPIN-022 over 24 h was obtained in M9 minimal medium supplemented with 1% sucrose, 0.5% yeast extract and 0.1% potassium chloride. FRIN-001-1 grew well in M9 medium with 1% mannitol, 0.5% yeast extract and 0.1% potassium phosphate dibasic.

• Applied Chemistry for Engineering
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• v.17 no.5
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• pp.458-464
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• 2006

The Pd-Ni-Ag alloy composite membrane using modified porous stainless steel (PSS) as a substrate was prepared by a electroless plating technique. In this work, we have introduced the intermediate layer between Pd-based alloy and a metal substrate. As an intermediate layer, the mixtures of nickel powder and inorganic sol such as $SiO_{2}$ sol, $Al_{2}O_{3}$ sol, and $TiO_{2}$ sol were used. The intermediate layers were coated onto a PSS substrate according to various membrane preparation conditions and then $N_{2}$ fluxes through the membranes with different intermediate layers were measured. The surface morphology of the intermediate layer in the mixture of nickel powder and inorganic sol was analyzed using scanning electron microscope (SEM). Finally, the Pd-Ni-Ag alloy composite membrane using the support coated with the mixture of nickel powder and silica as an intermediate layer was fabricated and then the gas permeances for $H_{2}$ and $N_{2}$ through the Pd-based membrane were investigated. The selectivity of $H_2/N_2$ was infinite and the $H_{2}$ flux was $1.39{\times}10^{-2}mol/m^2{\cdot}s$ at the temperature of $500^{\circ}C$ and trans-membrane pressure difference of 1 bar.

• The Korean Journal of Mycology
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• v.10 no.2
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• pp.57-65
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• 1982

Highly phosphorylated nucleotides were investigated to assure whether the eucaryotic Aspergillus niger produce these substances or not during the differentiation. Investigation was extended to see how organic phosphate interacts with inorganic polyphosphate during development, and high molecular weight RNA-polyphosphate complex was detected in 2.6% polyacrylamide gel by electrophoresis. Guanosine tetraphosphate was found in vesicle and phialide forming mycelia and spore forming body by PEI cellulose TLC. It is revealed that guanosine tetraphosphate is a common substance for spore formation in eucaryotic microorganisms as well as in procaryotic. Especially, prior to sporulation, protein bound RNA and protein bound phosphate may occur as a result of reorganization of cellular materials. The evidence was obtained by the fact of differential increase of optical density ratio between the samples from different developmental stages of this fungus. In 2.6% polyacrylamide gel which was run to electrophoresis, high molecular weight RNA (mostly rRNA) was found to couple and to make RNA-polyphosphate complex. The complex was examined with enzymes and radioactive isotope of $^{32}P$. (enzymic test was not reported here.) RNA-polyphosphate complex might be another sort of highly phosphorylated nucleotide or rRNA beside guanosine-tetraphosphate.