• Journal of the Korean Chemical Society
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• v.53 no.1
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• pp.27-33
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• 2009

A sensitive technique for the determination of trace Cd(II) in various real samples after preconcentration onto microcrystalline p-dichlorobenzene loaded with 2-mercaptobenzothiazole was developed. Several experimental conditions such as the pH of the sample solution, the amount of chelating agent 2-mercaptobenzothiazole, the amount of adsorbent p-dichlorobenzene-2-MBT, and the flow rate of sample solution were optimized. The interfering effects of various concomitant ions were investigated. Cu(II) interfered with more seriously than any other ions. However, the interference by Cu(II) could be overcome sufficiently by adjusting tartrate ion concentration to be 0.01M or by controlling the amount of 2-mercaptobenzothiazole contained in 0.20 g p-dichlorobenzene to be 0.12 g. The dynamic range, the correlation coefficient ($R^2$) and the detection limit obtained by this proposed technique were $0.5{\sim}30$ ng $mL^{-1}$, 0.9962, and 0.39 ng $mL^{-1}$, respectively. Thus, good results were obtained by the use of p-dichlorobenze as adsorbent matrix. For validating this proposed technique, the aqueous samples(wastewater, stream water, and reservoir water) and the plastic sample were used. Recovery yields of $93{\sim}104$ % were obtained. By F test, these measured data were not different from ICP-MS data at 95 % confidence level. Based on the results from the experiment, it was found that this proposed technique could be applied to the preconcentration and determination of Cd(II) in various real samples.

• Journal of the Korean Chemical Society
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• v.51 no.4
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• pp.331-338
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• 2007

A rapid, simple and sensitive spectrophotometric method was developed for the determination of cobalt(II) using 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC) as a analytical reagent. The metal ion in aqueous medium forms a brown coloured complex with HMBATSC at pH 6.0. The complex has two absorption maxima at 375 nm and 390 nm. At 375 nm, the reagent shows considerable absorbance, while at 390 nm the reagent does not shows appreciable absorbance. Hence, analytical studies were carried out at 390 nm. Beer's law is obeyed in the range of 0.059-2.357 μg ml-1 of Co(II). The molar absorptivity and Sandall's sensitivity of the method are 2.74×104 l mol-1 cm-1 and 0.0024 μg cm-2 respectively. The interference of various diverse ions has been studied. The complex has 1:2 [Co(II)- HMBATSC] stoichiometry. A method for the determination of cobalt(II) by second order derivative spectrophotometry has also been proposed. The proposed methods were applied for the determination of cobalt(II) in alloy steels, vitamin B12 and in some biological samples.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.159-159
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• 2003

Comet assay is a potential monitoring tool because DNA strand breakage may be produced by a wide range of agents. The comet assay, also called the single-cell gell electrophoresis (SCGE) assay, is rapid and sensitive method for the detection of DNA damage in cells. This study was performed for the identification of DNA damage in the cells from flounders and clams exposed to PAHs. As a control experiments, flounder and clam cells were exposed to $H_2O$$_2$. The cells exposed to $H_2O$$_2$ were displayed a typical nuclei movement DNA damage of cells were significantly increased when the isolated cells from the blood of flounders and the tissue of clams were in vitro exposed to the different concentrations (5, 10, 50, 100 ppb) of five kinds of PAHs (benzo[a]pyrene, pyrene, fluoranthene, anthrancene, and phenanthrene). For the in vivo test, flounders and clams were exposed to the different concentrations of BaP for 4 days. The results showed that DNA strand breakage was effected by the concentration of BaP and the duration of exposure. In high concentration of BaP, the mean tail lengths of nuclei was longer than it In low concentration, while the mean size of head DNA decreased. In this research, both in vitro and in vivo genotoxicity of PAHs could be biomonitored by the comet assay. Especially, clams and flounders seem to be useful as materials for monitoring genotoxic damage by comet assay.

• Molecules and Cells
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• v.27 no.2
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• pp.167-173
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• 2009

The classical type of transient receptor potential (TRPC) channel is a molecular candidate for $Ca^{2+}$-permeable cation channels in mammalian cells. Because TRPC4 and TRPC5 belong to the same subfamily of TRPC, they have been assumed to have the same physiological properties. However, we found that TRPC4 had its own functional characteristics different from those of TRPC5. TRPC4 channels had no constitutive activity and were activated by muscarinic stimulation only when a muscarinic receptor was co-expressed with TRPC4 in human embryonic kidney (HEK) cells. Endogenous muscarinic receptor appeared not to interact with TRPC4. TPRC4 activation by $GTP{\gamma}S$ was not desensitized. TPRC4 activation by $GTP{\gamma}S$ was not inhibited by either Rho kinase inhibitor or MLCK inhibitor. TRPC4 was sensitive to external pH with $pK_a$ of 7.3. Finally, TPRC4 activation by $GTP{\gamma}S$ was inhibited by the calmodulin inhibitor W-7. We conclude that TRPC4 and TRPC5 have different properties and their own physiological roles.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.1 no.1
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• pp.45-55
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• 1998

Purpose: To make objective standards of small intestinal mucosal changes in cow's milk-sensitive enteropathy (CMSE) we analyzed histological changes of endoscopic duodenal mucosa biopsy specimens from normal children and patients of CMSE. Methods: We review the medical records of patients who had been admitted and diagnosed as CMSE by means of gastrofiberscopic duodenal mucosal biopsy following cow's milk challenge and withdrawal. Thirteen babies with CMSE, ranging from 14 days to 56 days of age, were studied. Five non-CMSE patients were used as control, ranging from 22 days to 72 days of age. The morphometric parameters under study were villous height, crypt zone depth, ratio of villous height to crypt zone depth, total mucosal thickness and length of surface epithelium by using H & E stained specimens under the drawing apparatus attached microscope. In addition, the numbers of lymphocytes in the epithelium and eosinophil cells in the lamina propria and epithelium were measured. Results: In the duodenal mucosal biopsy specimens in CMSE we found partial and subtotal villous atrophy with an increased number of interepithelial lymphocytes. The mean villous height($135{\pm}59\;{\mu}m$), ratio of villous height to crypt zone depth ($0.46{\pm}0.28$), total mucosal thickness ($499{\pm}56\;{\mu}m$), length of surface epithelium of small intestinal mucosa ($889{\pm}231\;{\mu}m$) in CMSE was significantly decreased compared with the control (p<0.05). The mean crypt zone depth ($311{\pm}65\;{\mu}m$) was significantly greater than the control ($188{\pm}24\;{\mu}m$)(p<0.05). Infiltration of interepithelial lymphocytes ($34.1{\pm}10.5$) were significantly greater than the control ($13.6{\pm}3.6$)(p<0.05). The number of eosinophil cells in both lamina propria and epithelium was no significant differences between groups (p>0.05). The small intestinal mucosa in treated CMSE showed much improved enteropathy of villous height, crypt zone depth, interepithelial lymphocytes compared with the control as well as untreated CMSE. Conclusion: Quantitation of mucosal dimensions confirmed the presence of CMSE. It seems to be a limitation in the capacity of crypt cells to compensate for the loss of villous epithelium in CMSE. Specimens obtained by gastrofiberscopic duodenal mucosal biopsy were suitable for morphometric diagnosis of CMSE. Improvement of CMSE also can be confirmed histologically after the therapy of protein hydrolysate.

• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.125-136
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• 1994

To characterize the SR Ca-release channel protein complex of crustacean, $^{45}Ca-release,\;[^3H]ryanodine$ binding, and immunoblot studies were carried out in the crayfish and/or lobster skeletal sarcoplasmic reticulum. Bmax and affinity of crayfish SR to ryanodine were lower than those of lobster SR. AMP (5mM) increased $[^3H]ryanodine$ binding significantly in both vesicles (P<0.05). $Mg^{2+}$(5mM) or tetracaine(1mM) inhibited $[^3H]ryanodine$ binding significantly in both vesicles (P<0.001), but ruthenium red $(10\;{\mu}M)$ inhibited it moderately. In SDS polyacrylamide gel electrophoretic analysis of crayfish SR vesicles, there was a high molecular weight band that showed similar mobility with Ca-release channel protein of lobster skeletal SR, but more rapid mobility (HMWBr) than that of rabbit skeletal SR (HMWBS). Immunoblot analysis showed that polyclonal Ab to lobster skeletal SR Ca-release channel protein was react with HMWBr of crayfish skeletal SR, but not with that of HMWBs of rabbit skeletal SR. ^{45}Ca-release from crayfish skeletal SR vesicles was increased by the increase of extravesicular calcium from $1{\mu}M$ to 1mM. This Ca-release phenomenon was similar, but more sensitive in the low concentration of $Ca^{2+}$, compared to that from lobster SR vesicles. AMP (5mM) or caffeine (10mM) did not affect to $^{45}Ca-release.\;^{45}Ca-release$ was inhibited slightly ($3{\sim}8%\;by\;Mg^{2+}$) (5mM) or tetracaine (1mM), and moderately (23%) by high concentration of ruthenium red $(300\;{\mu}M)$. From the above results, it is suggested that SR Ca-release channel protein of crustacean has different properties from that of the rabbit, and similar properties between crayfish and lobster in functional and immunological aspects, but Ca-release via crayfish channel may be more sensitive to calcium.

• Journal of Microbiology and Biotechnology
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• v.8 no.5
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• pp.497-500
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• 1998

A new strain of Bacillus capable of growing upto pH 11 was isolated from a local pond polluted with detergents. This strain elicited unimpaired growth in media supplemented with heavy metals such as As, Cu, Cd, Hg, Ni and Zn. A MIC value of 200, 3, 1.60, 2.25, 7.50 and 3.70 mM was noticed for As, Cu, Cd, Hg, Ni and Zn respectively. Analysis of total DNA revealed the presence of a plasmid of 26 kb. This plasmid was lost by acriflavine treatment to the cultures. Such cured strains were found sensitive to heavy metals. Our findings suggest that incidence of heavy metal resistance is widely distributed and resistant strains could be isolated from heavy metal unpolluted sites.

• Mycobiology
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• v.36 no.2
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• pp.99-101
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• 2008

The alkaloid securinine was assessed against spore germination of some plant pathogenic and saprophytic fungi (Alternaria alternata, Alternaria brassicae, Alternaria brassicicola, Curvularia lunata, Curvularia maculans, Curvularia pallenscens, Colletotrichum musae, Colletotrichum sp., Erysiphe pisi, Helminthosporium echinoclova, Helminthosporium spiciferum, Heterosporium sp.). Spore germinations of all the tested fungi were inhibited. Alternaria brassicicola, C. lunata, C. pallenscens and H. spiciferum were highly sensitive as complete inhibition of spore germination was observed at very low concentrations (200 ppm).

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.171-175
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• 1998

To test their roles in rumination behavior, metabolites (acetic acid, propionic acid, butyric acid and glucose) were intravenously infused into the jugular vein of goats during fasting. The heads of four female goats tested were locked in a stanchion of cages in an experimental room. Ruminating behaviors with regard to number of ruminations, ruminating time, number of remastications and remasticating time were significantly decreased by acetic acid infusion (p < 0.05), and tended to be depressed more on values in butyric acid infusion or glucose infusion than those in pre-infusions, but propionic acid infusion decreased a little. Those data suggest that rumination receptors sensitive to VFAs and glucose are more likely to be situated in the area, where they would respond too blood levels.

• Journal of Electrochemical Science and Technology
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• v.8 no.4
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• pp.307-313
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• 2017

In this paper we report an electrochemical sensor based on ZnO-functionalized graphene oxide nanocomposite (ZnO-GO) for the sensitive determination of the cabergoline. Cabergoline electrochemical behaviors were investigated by cyclic voltammetry (CV), chronoamperometry (CHA) and differential pulse voltammetry (DPV). The modified electrode shows electrocatalytic activity toward cabergoline oxidation in phosphate buffer solution (PBS) (pH 7.0) with a reduction of the overpotential of about 180 mV and an increase in peak current. The DPV data showed that the obtained anodic peak currents were linearly dependent on the cabergoline concentrations in the range of $1.0-200.0{\mu}M$, with the detection limit of $0.45{\mu}M$. The prepared electrode was successfully applied for the determination of cabergoline in real samples.