• Nano
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• 제13권10호
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• pp.1850116.1-1850116.14
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• 2018

In this study, we report the mercury ions ($Hg^{2+}$) mediated phosphorus-containing carbon dots (PCDs) as a selective "off-on" fluorescence probe for glutathione (GSH), cysteine (Cys) and homocysteine (Hcys). PCDs obtained by hydrothermal reaction are sensitive to $Hg^{2+}$ ions and its fluorescence can be significantly quenched owing to the electron transfer from the lowest unoccupied molecular orbital (LUMO) of PCDs to $Hg^{2+}$. Interestingly, the weak fluorescence of $Hg^{2+}$-mediated PCDs could be gradually recovered with the addition of GSH, Cys and Hcys. This can be attributed to the formation of $Hg^{2+}-S$ complex due to the super affinity of $Hg^{2+}$-sulfydryl bond. The formation of $Hg^{2+}-S$ complex extremely reduces the oxidation ability of $Hg^{2+}$ that inhibits the electron transfer from LUMO of PCDs to $Hg^{2+}$ and re-opens the native electron transition from LUMO to the highest occupied molecular orbital (HOMO) of PCDs. Thus, the green fluorescence of PCDs is switched on. Furthermore, the present $Hg^{2+}$-mediated PCDs assay exhibits a high selectivity for GSH, Cys and Hcy and has been successfully used to detect the total biothiols content in human urine samples.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.100-100
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• 2003

An image processing algorithm has been developed in order to analyze the nanofiber web images obtained from a high magnification microscope. It has been known that precise pore detection on thick webs is extremely difficult mainly due to lack of light uniformity, difficulty of fine focusing and translucency of nanofiber web. The pore detection algorithm developed has been found to show excellent performance in characterizing the porous structure, thus being a promising tool for on-line quality control system under mass production. Since the images obtained from an optical microscope represent only web surface, a scale factor has been introduced to estimate the web structure as a whole. Resulting web structures have been compared to those by mercury porosimetry, especially in pore size distribution. It has been shown that those two structures have a strong correlation, indicating that scaling of a single layer web structure can be an effective way of estimating the structure of thick fiber webs.

• 한국환경과학회지
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• 제19권8호
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• pp.941-949
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• 2010

The three electrode system was used to detect the pesticide fenitrothion ($C_9H_{12}NO_5PS$. MW=277.24) using cyclic voltammetry (CV) and square wave anodic stripping voltammetry (SWASV). The working electrode was mercury immobilized on a carbon nanotube paste electrode (Hg-CNTPE). At the optimized condition, the limit of detection (LoD) was 0.6 ppt ($2.16{\times}10^{-12}\;M$), and the relative standard deviation was 0.035% (n=15). And there is more sensitive in detecting fenitrothion than common type carbon nanotube paste electrode. When it was implanted into the brain of live fish (carp), the existence of fenitrothion was measured without any destruction or damage of tissue.

• 한국어병학회지
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• 제30권2호
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• pp.115-134
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• 2017

A total number of 668 apparently healthy fish were obtained from farm to study the effect of two heavy metals (Copper and Mercury) on histopathology of liver, kidney, spleen, gills and muscles also residues in muscles. The $LC_{50}$/96 hr. of Cu and Hg were estimated and fish exposed to 1/2 $LC_{50}$ for 7 days and for 1/10 $LC_{50}$ for 8 weeks from each product separately. Histopathological findings in acute and chronic mercuric chloride toxicity revealed degeneration and necrosis in the glomeruli, interstitium tissue and epithelium lining renal tubules. The tubular epithelium became necrotic at several places. Eosinophilic hyaline droplets is exist in the cytoplasm of the necrosed cells. Degenerative changes and hyperactivity in melanomachrophage center was seen in the spleen together with some necrotic areas. Necrosis and aggregation of melanomachrophage were seen in the hepatic cells, Hepatic cells showed vacuolar degeneration in the hepatic cells. Gills showed loss in the lamellae of the filaments associated with edema, inflammatory cells infiltration and haemorrhages in the arch. The sarcoplasm of the bundles of the skeletal muscle showed granular degeneration and focal inflammatory cells infiltration between the hyalinized bundles. Mercury residues obtained from these studies in the acute toxicity were 0.22 ppm/gm in the 2nd day, 0.411 ppm/gm in the $5^{th}$ day ended with 0.96 ppm/gm in the $7^{th}$ day. In chronic toxicity it was 1.1320, 1.7140, 2.3620 and 3.5640 ppm/gm respectively from the $2^{nd}$ to the $8^{th}$ week of exposure. In acute and chronic copper toxicity, there was degenerative changes in renal tubules. Melanophores aggregation in the wall of the blood vessels of the spleen and depletion of some of the melanophores in the melanomachrophage were seen together with necrosis in some areas. Congested Mvs (Micro vessels) and vacuolation of hepatocytes were observed. Some areas of hemorrhage and melanophores vacuolar degeneration in the liver were seen. There was mitosis in some areas with displesia of hepatopancreatic cells and eosinophilic granular cells aggregation. Zymogen granules disappeared and there were dyplastic hepatocytes. Congestion in the blood vessels of the gill filaments, associated with massive number of granular eosinophilic cells infiltration were seen in the base of the filaments. There were sever vacuolization and hyalinization in the skeletal muscle bundles. Detection of residues of copper sulfate revealed increase of the amount of copper measured in ppm/gm comparing to the normal control starting from 0.60 ppm/g in the $2^{nd}$ day, 0.67 ppm/g in the $5^{th}$ day and 0.67 ppm/g in the $7^{th}$ day. Result obtained in chronic copper sulfate toxicity revealed gradual increase of the amount of copper which ranged from 0.18 ppm/g at the $2^{nd}$ week to 0.21 ppm/g in the $8^{th}$ week of exposure.

• 분석과학
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• 제12권4호
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• pp.299-305
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• 1999

Electrolyte as cathode glow discharge(ELCAD)는 용액 중에 포함된 미량 중금속을 연속 자동 측정하기 위한 새로운 플라스마 source로서 주로 원자방출법에 의하여 원소들을 측정한다. 그러나 수은의 경우 원자 방출법보다는 원자 흡수법을 주로 적용한다. 본 연구에서는 기존의 원자흡수분광기의 원자화부분을 ELCAD cell로 대치하여 원자흡수법에 의하여 수은을 측정하였다. 일반적으로 원자방출법에 의하여 원소들의 방출선측정시 용액의 pH가 1.0에서 가장 안정한 플라스마와 가장 큰 방출세기를 나타내었으나 수은인 경우 pH 3.0에서 가장 흡광도가 높았다. 그러나 플라스마의 안정도는 pH가 1.0 일 때가 가장 좋은 관계로 흡광도의 % RSD 값은 pH 1.5 용액에서는 0.35% 이었으며 pH 3.0인 검액에서는 3.6%를 나타내었다. 두 검액에 대해 각각 검량곡선을 작성하였을 때 모두 양호한 직선성을 보였으며, 각각의 검출 한계를 구한 결과, pH 1.5 용액은 약 40 ppb, pH 3.0 용액은 10 ppb level 이었다.

• 대한화학회지
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• 제54권4호
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• pp.451-459
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• 2010

세포내의 중금속이온의 형광검출은 유기분자화학과 세포생물학분야에서 높은 관심을 갖는다. 이 연구는 형광화학센서(FS)를 이용한 Hg$^{2+}$ 과 Zn$^{2+}$의 세포 내 검출을 목적으로 하였다. FS는 약한 형광을 나타내지만 Zn$^{2+}$와 결합 시에는 강한 방출 형광은 낸다. 2FS/Zn$^{2+}$의 형광증가는 FS-Hg$^{2+}$결합의 형성할 때 Hg$^{2+}$ 1당량만 추가에도 완전한 형광감소를 나타낼 수 있었다. 네가지의 세포주(LLC-MK2, Hela, HT29 and AMC-HN3)는 공촛점 현미경에 대한 형광이미지를 위하여 사용하였다. 세포생존능은 LLC-MK2 세포주에 FS, Zn$^{2+}$, FS-Zn$^{2+}$, Hg$^{2+}$의 처리 후에 평가하였다. FS의 세포독성능은 80%이상의 생존능을 보였다. 본 연구에서는 FS가 살아있는 세포내의 Hg$^{2+}$과 Zn$^{2+}$의 선택적 이미지를 검출할 수 있음을 보여주었다.

• 대한화학회지
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• 제57권5호
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• pp.568-573
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• 2013

A selective and sensitive method for simultaneous determination of copper in blood by adsorptive differential pulse cathodic stripping voltammetry is presented. The procedure involves an adsorptive accumulation of Cu(II)-ETSC (4- ethyl-3-thiosemicarbazide) on a hanging mercury drop electrode, followed by a stripping voltammetry measurement of reduction current of adsorbed complex at about -715 mV. The optimum conditions for the analysis of copper (II) ion are : pH 10.3, concentration of 4-ethyl-3-thiosemicarbazide $3.25{\times}10^{-6}$ M and an accumulation potential of -100 mV. The peak current is proportional to the concentration of copper over the range 0.003-125 ng/mL with a detection limit of 0.001 ng/mL and an accumulation time of 60 s. Moreover, with the use of the proposed method, there is a considerable improvement in the detection limit, the linear dynamic range and the deposition time, compared with the methods of adsorptive stripping voltammetry for the determination of copper. The developed method was validated by analysis of whole blood certified reference materials.

• Bulletin of the Korean Chemical Society
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• 제25권5호
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• pp.694-698
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• 2004

A new method for the simultaneous determination of seven transition metal ions in water and food by microcolumn high-performance liquid chromatography has been developed. The lead, cadmium, mercury, nickel, cobalt, silver and tin ions were pre-column derivatized with tetra-(4-aminophenyl)-porphyrin ($T_4$-APP) to form the colored chelates which were then enriched by solid phase extraction with $C_{18}$ cartridge. The enrichment factor of 50 was achieved by eluted the retained chelates from the cartridge with tetrahydrofuran (THF). The chelates were separated on a ZORBAX Stable Bound microcolumn ($2.0{\times}50\;mm,\;1.8\;{\mu}m$)with methanol-tetrahydrofuran (95 : 5, v/v, containing 0.05 mol/L pyrrolidine-acetic acid buffer salt, pH = 10.0) as mobile phase at a flow rate of 0.5 mL/min and detected with a photodiode array detector from 350-600 nm. The seven chelates were separated completely within 2.0 min. The detection limits of lead, cadmium, mercury, nickel, cobalt, silver and tin are 4 ng/L, 3 ng/L, 6 ng/L, 5 ng/L, 5 ng/L, 6 ng/L, 4 ng/L respectively in the original samples. This method was applied to the determination of the seven transition metal in water and food samples with good results.

• 대한통합의학회지
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• 제8권4호
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• pp.307-321
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• 2020

Purpose : A person infected by SARS-CoV2 may present various symptoms such as fever, pain in lower respiratory tract, and pneumonia. Measuring body temperature is a simple method to screen patients. However, changes in the surrounding environment may cause errors in infrared measurement. Hence, a non-contact thermometer controls this error by setting a correction value, but it is difficult to correct it for all environments. Therefore, we investigate device error values according to changes in the surrounding environment (temperature and humidity) and propose guidelines for reliable patient detection. Methods : For this study, the temperature was measured using three types of non-contact thermometers. For accurate temperature measurement, we used a water bath kept at a constant temperature. During temperature measurement, we ensured that the temperature and humidity were maintained using a thermo-hygrometer. The conditions of the surrounding environment were changed by an air conditioner, humidifier, warmer, and dehumidifier. Results : The temperature of the water bath was measured using a non-contact thermometer kept at various distances ranging from 3~10 cm. The value measured by the non-contact thermometer was then verified using a mercury thermometer, and the difference between the measured temperatures was compared. It was observed that at normal surrounding temperature (24 ℃), there was no difference between the values when the non-contact thermometer was kept at 3 cm. However, as the distance of the non-contact thermometer was increased from the water bath, the recorded temperature was significantly different compared with that of mercury thermometer. Moreover, temperature measurements were conducted at different surrounding temperatures and the results obtained significantly varied from when the thermometer was kept at 3 cm. Additionally, it was observed that the effect on temperature decreases with an increase in humidity Conclusion : In conclusion, non-contact thermometers are lower in lower temperature and dry weather in winter.

• 센서학회지
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• 제23권6호
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• pp.362-367
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• 2014

In this study, a postural change detection sensor module (PCDSM) was developed to detect postural changes in activities of daily living (ADL) and falls. The PCDSM consists of eight mercury sensors that measure angle variations in $360^{\circ}$ rotation and $90^{\circ}$ tilting. From the preliminary study, the output characteristics of the PCDSM were confirmed with the angle variations of rotational motion and a tilting table. Three experiments were conducted to test rotational motion, postural changes, and falling and lying. The results confirmed that the PCDSM could effectively detect postural changes, movement patterns, and falls or non-falls.