• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권6호
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• pp.413-420
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• 2002

Mercury is one of the most frequently used heavy metal in dental clinic. Mercury poisoning rises up when someone is exposed to mercury chronically. In 1818, Amalgam was used for dental restorative procedure, and after then study about mercury toxicity has begun. Clinical signs of mercury toxicity in oral & maxillofacial area were increases of salivation, metallic taste, swelling and pain of tongue, redness and ulceration of oral mucosa, and increased mobility and loss of teeth. After we injected mercury($HgCl_{2}$) into intraperitoneum of rat, studied about histopathological changes of submandibular gland cell. Experimental group was divided into two groups by amount of mercury. (Group 1 was 0.5mg/Kg of mercury injection, group 2 was 1.0mg/Kg of mercury injection.) 1. After 3days of intraperitoneal injection, black granules were observed at macrophage cell in both group. In group 2, author found hyperchromatism of nucleus, and vacuolization of cellular matrix and nucleus of acinar cell. 2. After 1week of intraperitoneal injection, author found severe vacuolization of nucleus and cellular matrix, and irregular granules around nuclear membrane at mucous cell and serous cell in both group. Vacuolization of nucleus and cellular matrix was seen at duct cell in group 2. 3. After 2weeks of intraperitoneal injection, author could found severe vacuolization of cellular matrix, and sometimes nucleus was positioned in central area of cellular matrix at mucous and serous cell in both group. Vacuolization of nucleus and cellular matrix was found at vascular endothelial cell in group 2. 4. After 4weeks of intraperitoneal injection, destruction and distortion of gland cells were distinct. Vacuolization and destruction of nucleus and cellular matrix was found at duct cell in group 2. After intraperitoneal injection of mercury, we found equanimity of mercury and destruction of cellular matrix at serous cell, mucous cell, and duct cell of submandibular gland. So, we thought that metallic taste of mercury poisoning patient would be due to excretion of saliva containing mercury.

• 한국식품영양과학회지
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• 제21권1호
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• pp.70-75
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• 1992

본 연구는 cadmium의 축적균주인 Pseudomonas maltophilia H-8을 MNNG로 처리하여 cadmium축적능이 가장 우수한 변이균주인 Pseudomonas maltophilia H-8M을 얻었고 그 특성을 조사하였다. 변이주 Pseudomonas maltophilia H-8M은 카드뮴농도 1,000ppm에서 36시간 배양했을 시 대조구에 비해 약 80%정도의 성장률을 나타내었다. 카드뮴 이외의 중금속의 첨가에 따른 생육상은 $Pb^{2+}$, $Zn^{2+}$, $Hg^{2+}$, $Cu^{2+}$, $Cr^{2+}$, $Co^{2+}$ 등에는 별다른 성장 억제는 없었으나 $Sn^{2+}$에서는 생육억제가 나타났다. 또한 50ppm의 카드뮴을 배지에 첨가 하였을 때 균체내 카드뮴 축적율은 52.92%로 가장 높게 나타났으며 축적부위는 세포벽에 80.3%의 축적율을 나타내었다.

• 자원리싸이클링
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• 제17권3호
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• pp.3-9
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• 2008

하수슬러지 소각재를 대상으로 화학 조성과 물리화학적 물성을 측정하고 재활용을 위한 경량재료 제조실험을 수행하였다. 경량재료는 하수슬러지 소각재를 원료로 하여 경량충진제와 무기바인더를 첨가하여 성형 및 소성하는 방법으로 제조하였으며, 제조 조건에 따른 비중과 압축강도 변화를 측정하였다. 비산재의 pH 경우 배기가스 중화를 위한 알칼리 첨가로 인하여 알칼리성인 pH 8.69로 나타났으나 바닥재는 중성인 pH 6.48이었다. 공정시험법에 근거하여 하수슬러지 소각재에 대한 중금속 용출실험 결과, Cd, Cu, Pb, As, Cr의 5개 원소 모두에 대하여 용출량이 검출한계치 이하로 나타났다. 동일한 혼합비율의 경우 비산재를 사용한 경량재료 시편의 압축강도가 바닥재에 비해 높게 나타나 비산재를 원료로 사용하는 것이 보다 효과적임을 알 수 있었다.

• 한국환경보건학회지
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• 제36권3호
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• pp.236-246
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• 2010

In preparative anti-corrosive coating experiments, polyaniline was obtained by reacting an oxidizing agent with the monomer aniline. Further, the primer coating was prepared using a variety of widely-used materials such as urethane resin. For the top coating, epoxy resin and acrylic urethane resin were used. Characteristics of the coatings were assessed according to KS and ASTM specifications, and the structure of the polyaniline was characterized using FT-IR and TGA. For analysis of anti-corrosive properties in salt-spray experiments, measurements of the oxidation state of iron and surface atomic analysis were conducted using XPS and SEM-EDX. Unlike general anti-corrosive coatings which exhibit anti-corrosive effects only as a primer coating, the anti-corrosive coatings using polyaniline as the anti-corrosive pigment showed a marked synergistic effect with the top coatings. In other words, the top coatings not only produce a fine view effect, but also increase, through interaction with the primer coatings, the resistance to diffusion of corrosive factors from the external environment. It was also found that, unlike the heavy metal oxide-forming layer of the passive barrier alone, the polyaniline anti-corrosive pigment oxidized iron at the interface with the iron substrate to form a passive barrier in the oxidic layer, and itself formed a potential barrier layer with anti-corrosive factors from the external environment. Although the passive layer was damaged, the damaged area did not become completely oxidized iron; on the contrary, it showed a tendency to reduction. This can be interpreted such that a passive layer is formed again on the damaged area, and that at the same time there is a tendency to self-healing.

• 한국환경생태학회지
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• 제12권1호
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• pp.22-29
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• 1998

충남지역의 사문암과 변성암 및 흑색셰일지역의 암석, 토양 및 그 위에서 생육하는 리기다소나무의 미량원소 함량을 측정하여 모암별 토양의 원소함량과 식물체의 흡수확계를 조사하였다. Ni, Cr 및 Co 함량은 사문암에서 매우 높았으며, Zn, Mo 및 Fe 함량은 변성암에서 높았다. 흑색셰일의 이들 원소는 사문암과 변성암보다 공히 낮았다. 사문암 토양의 Ni, Cr 및 Co 함량은 매우 높았으며, Zn과 Fe 함량은 사문암+변성암 혼합풍화토 및 흑색셰일 토양에서 높았다. 풍화토의 미량원소 함량은 암석의 함량보다 낮았으며, 그 패턴은 Mo를 제외하고는 모두 유사하였다. 사문암 풍화토의 pH 범위는 7.73~9.55로 매우 높았다. 사문암지역 리기다소나무의 Cr 흡수량은 토양내 Cr함량에 비하여 낮았으며, Zn 은 토양내의 원소함량에 비하여 리기다소나무에 의한 흡수량이 높았다. 리기다소나무에 의하여 흡수된 Ni, Fe 및 Co 함량에 대한 Fe/Ni, Co/Ni 비율은 사문암풍화토에서 가장 낮았다.

• Bulletin of the Korean Chemical Society
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• 제27권11호
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• pp.1801-1808
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• 2006

The interaction between whey carrier protein $\beta$-lactoglobulin type A and B (BLG-A and -B) and 2,2'-bipyridin n-hexyl dithiocarbamato Pd(II) nitrate (BPHDC-Pd(II)), a new heavy metal complex designed for anticancer property, was investigated by fluorescence spectroscopy combined with chemometry and circular dichroism (CD) techniques. A strong fluorescence quenching reaction of BPHDC-Pd(II) to BLG-A and -B was observed. Hence, BPHDC-Pd(II) complex can be bound to both BLG-A and -B, and quench the fluorescence spectra of the proteins. The quenching constant was determined using the modified Stern-Volmer equation. The binding parameters were evaluated by fluorescence quenching method. The results of binding study provided evidences presence of two and three sets of binding sites on the BLG-B and -A, respectively, for BPHDC-Pd(II) complex. Using fluorescence spectroscopy and chemometry, the ability of BLG-A and -B to form an intermediate upon interaction with BPHDC-Pd(II) complex was assessed. CD studies displayed that under influence of different concentrations of BPHDC-Pd(II) complex, the regular secondary structure of BLG-B had no significant changes, whereas for BLG-A a transition from $\alpha$-helix to $\beta$-structure was appeared. The results for both of BLG-A and -B displayed that BPHDC-Pd(II) complex can induce a conformational transition from the native form to an intermediate state with a slightly opened conformation, which is detectable with chemometry analyses.

• 대한약침학회지
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• 제23권2호
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• pp.71-78
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• 2020

Objectives: This study was conducted to development of hazardous materials management standards for the decoction type of personalized herbal medicines (PHMs). Methods: This study was conducted in two stages. We searched documents about criteria to use words such as 'Herb', 'Herbal medicine', and 'Botanical Drug' and summarized the results. We organized the committee consisted of seven experts, and held two meetings to reach an agreement on hazardous management standards of the decoction type of PHMs. Results: The seven documents were presented in the literature review and six items related to hazardous management standards of decoction were identified. The second expert meeting brought that a total of six items, including heavy metal, pesticide residues, sulfur dioxide, benzopyrene, mycotoxin, and micro-organism limits, were selected for safety management of decoction type of PHMs. Also, the criteria and test methods for each standard were suggested for monitoring the decoction type of PHMs. Conclusion: The study suggested hazardous material management standards and criteria for the decoction types of PHMs. In the future, it would be necessary to conduct a pilot test to ensure the validity and credibility of the safety management standard and criteria. Furthermore, the government level safety management system should be introduced to verify the safety of decoction medicines.

• 미생물학회지
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• 제33권2호
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• pp.125-130
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• 1997

미생물에 의한 6가이온 크롬의 3가이온으로의 환원은 세균에게 크롬내성을 제공할 수 있는 것으로 알려져 있다. 본 연구에서는 이러한 가설을 확인하기 위하여 크롬오염 토양과 오염되지 않은 토양으로부터 형태적으로 다른 20종의 세균을 순수분리하고 각각의 균주에서 크롬내성과 크롬환원능을 상호 비교하였다. 전자의 공여체로 glucose를 사용했을 때 세포현탁액에 의한 크롬의 환원은 시간당 0.014-0.305mM Cr(VI)의 범위로 관찰되었으며, 액체배지에서 2mM의 크롬에 대한 내성은 크롬을 첨가하지 않은 배지에서 배양한 경우와 혼탁도를 비교한 결과 전혀 저해를 받지 않는 경우부터 93.4%의 성장저해를 받는 경우까지 다양하게 관찰되었다. 이러한 결과로부터 상관관계를 분석한 결과 크롬내성과 크롬환원은 전혀 상관이 없는 것으로 계산되었다. 한편 군집수준에서의 크롬내성비교는 크롬오염 토양과 오염되지 않은 토양에서 각각 19.1%와 0.4%로 나타나 크롬의 존재는 내성균주의 선택적 성장을 유도하는 것으로 밝혀졌다. 그러나 이때 획득된 크롬에 대한 내성은 크롬의 환원에 의해서 제공되는 것이 아님을 상관관계 분석으로부터 알 수 있었다.

• 한국환경과학회지
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• 제7권2호
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• pp.141-148
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• 1998

Effects of alumlnlum(AA), soil pH and calcium(Cal on growth response and heavy metal accumulation and regulation of nitrogen fixation In Melilotus suaveolens seedlings, a biennial legume plant dominating in the disturbed area, were quantitatively analyzed during the growing periods. Accumulation of metals In each organ of M. suaveojens was Increased UC the lowering of pH. Al contents In leaf and root treat- ed with 30ppm Al at pH 4.2 on the 28th day after treatment were 8 and 11 folds higher than those of control, while the contents with 100ppm AA were 21 and 24 folds as compared to control. The significent inhibition in Al contents was induced by 100ppm AA and Ca at pH 6.5. Increased metals inhibited higher at pH 4.2 and the growth inhibition due to Al was reversed by the addition of Ca, suggesting that growth correlates to the pH value. Chlorophyll contents in leaves increased during growth stave were inhibited by Al treatments. The biomass was decreased UD the lowering of pH and the increase of concentrations. 100ppm Ca treatment resulted in 5.1-5.9% increase of the biomass as compared to that of 100ppm Al. Specific nitrogen fuation activities In nodules In the 100ppm Al at pH 4.2 and pH 6.5 were reduced to 35. 2% and 52.2% of control, on the 28th day after treatment, while the combination of Al and Ca induced reduced by 10% as compared to control with the treatment of 100ppm AA at pH 4.2 due to the inhibition bination of 100ppm Al and Ca and lowering of pH.

• 한국환경과학회지
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• 제21권3호
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• pp.369-375
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• 2012

We investigated usefulness of chicken feather as bioadsorbent for removal of hexavalent chromium[Cr(VI)] and oil from aqueous solution. Chicken feather was chemically treated with DTPA, EDTA, NaOH and SDS, respectively. Among them, EDTA was the most effective in adsorbing Cr(VI). Cr(VI) uptake by chicken feather was increased with decreasing pH; the highest Cr(VI) uptake was observed at pH 2.0. By increasing Cr(VI) concentration, Cr(VI) uptake was increased, and maximum Cr(VI) uptake was 0.34 mmol/g. Cr(VI) adsorption by chicken feather was well described by Freundlich isotherm than Langmuir isotherm and Freundlich constant(1/n) was 0.476. As the concentration of chicken feather was increased, Cr (VI) removal efficiency was increased but Cr(VI) uptake was decreased. Most of Cr(VI) was adsorbed at early reaction stage(1 h) and adsorption equilibrium was established at 5 h. On the other hand, chicken feather adsorbed effectively oils including bunker-A and bunker-C. In conclusion, our results suggest that chicken feather waste could be used to remove heavy metal and oil; it is a potential candidate for biosorption material.