• Food Science and Preservation
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• v.23 no.2
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• pp.283-289
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• 2016

Naturally occurring antioxidants, such as polyphenols are widely found in fruits, vegetables, wines, juices, and other plant-based dietary sources and are divided into several sub classes, including phenylpropanoids, flavonoids, stilbenoids, and lignans. As part of the our ongoing search for bioactive food ingredients, the antioxidant and advanced glycation end products (AGEs) formation inhibitory activities of the methanolic extract of the aerial parts of Cirsium setidens were investigated in vitro bioassay system. The antioxidant properties were evaluated through radical scavenging assays using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) ($ABTS^+$) radicals. In addition, the activity of C. setidens against diabetes complications was also tested via AGEs formation inhibition assay. The total phenolic contents were determined using a UV-VIS spectrophotometric method. All tested samples showed a dose-dependent radical scavenging and AGEs inhibitory activities. In particular, the n-butanol (BuOH)-soluble portion showed the most potent radical scavenging activities against DPPH and $ABTS^+$ radicals with $IC_{50}$ values of $24.3{\pm}1.7$ and $25.0{\pm}3.3{\mu}g/mL$, respectively. Futhermore, the inhibition of AGEs formation by the n-BuOH-soluble portion ($IC_{50}$ value; $46.0{\pm}1.5{\mu}g/mL$) was higher than that those of the soluble portions for the other solvent. The results showed that C. setidens could be considered as an effective source of natural antioxidants and other ingredients.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.193-204
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• 1998

The single crystal of the $LiTaO_3$has large electro-optic effects, so it is applied to optical switch, acousto-optic deflector, and optical memory device as hologram using photorefractive effect. In this study, optic-grade undoped $LiTaO_3$and Fe:LiTaO$LiTaO_3$single crystals were grown by the Czochralski method and optical transmission and absorption spectrums were measured in the wavelength of UV-VIS range. The curie temperature was determined with DSC and by measuring capacitance for the grown undoped crystal and ceramic powder samples of various Li/Ta ratio. In case of having a 48.6 mol% $Li_2O$ as a starting Li/Ta ratio, the results of concentration variations were below 0.01 mol% $Li_2O$ all over the crystal, so it was confirmed that $LiTaO_3$single crystals were grown under congruent melting composition having optical homogeneity. The curie temperature of the Fe:$LiTaO_3$crystal was increased with increased with increased doped Fe concentrations;by the ratio of $7.5^{\circ}C$ increase per Fe 0.1 wt%. Also, the optical transmittance was about 78 %, which was sufficient for optical device.

• Journal of Gastric Cancer
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• v.8 no.3
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• pp.120-128
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• 2008

Purpose: Mistletoe extract was widely used for cancer treatment as complementary or alternative therapy in European area from early twenty century. It is currently used as alternative anti-cancer remedy by piecemeal in domestic medical group, however, the anti-cancer mechanism of mistletoe extract was not known precisely until now. In this study the effect of mistletoe extract on gastric cancer was studied vis cell line experiments. Materials and Methods: The SNU719 gastric cancer cell line was used, and ABNOBAviscum-Q and ABNOBAviscum-F were treated to cells as mistletoe extract, or 5-FU and cisplatin were used with mistletoe extract. The cell viability and cell death rate were estimated by CCK-8 assay kit and lactate dehydrogenase (LDH) assay kit in each. Caspase 3 assay kit was used to measure caspase 3 activity. The protein expression amounts of Bcl2, p53, and PTEN were estimated through Western blot analysis. Results: The co-treatments of mistletoe extract Q/F and 5-FU/cisplatin decreased lesser cell viability than only mistletoe treat. Caspase 3 activity was increased 4~6 times in co-treatment of mistletoe extracts and 5-FU than control. Bcl2 protein expression was reduced by mistletoe extracts or anti-cancer drugs, further more, the co-treatment of mistletoe extracts and 5-FU/cisplatin diminished more the expression than only mistletoe treatment. Mistletoe extracts did not affect the protein expressions of p53 and PTEN. Conclusion: It was concluded that the anti-cancer mechanism of mistletoe extracts was made by caspase 3 activation and lowered Bcl2 expression, and this apoptosis inducing mechanism was independent to p53.

• Korean Journal of Poultry Science
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• v.28 no.2
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• pp.99-106
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• 2001

Pathologic changes and distribution of viral antigen as determined by immunohistochemistry were compared among 4-wk-old specific-pathogen free (SPF) chickens inoculated intratracheally with velogenic vis-cerotropic Newcastle disease virus isolated in Korea. Although the pattern of organ involvement and severity of lesion was different among chickens infected with different velogenic viscerotropic Newcastle disease (VVND) viruses, the pathological types of lesion was similar among the chickens. Severe lymphocytic necrosis and depletion were main histologic lesions in the immune related organs such as thymus, Fabricius bursa and spleen. The frequency of IP positive staining was variable depends on the types of tissues but not types of the kinds of VVND viruses infected. Brain, Fabricius bursa, thymus, cecal tonsil and trachea were IP positive with fairly high frequency and spleen, lung, proventriculus, intestine, pancreas, liver, kidney, heart and Harderian gland were with relatively low frequency. These results suggest that histologic evaluation and viral antigen specific immunohistochemical staining methods to determine virus distribution will be useful for pathogenic study of velogenic viscerotropic Newcastle disease virus infection in chicken.

• Journal of the Korean Chemical Society
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• v.37 no.11
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• pp.951-960
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• 1993

$Hg^{2+}$-induced aquation trans-[Co(3,2,3-tet)$X_2]^+$(3,2,3-tet = 4,7-diazadecane-1,10-diamine, $X_2\;=\;Cl_2,\;(NO_2)Cl,\;Br_2,\;(NO_2)Br,\;(NO_3)_2)$ complexes was investigated in aqueous solution. The products and the reaction mechanism were confirmed by chromatography, UV/Vis. spectrum, and circular dichroism (CD) spectrum. From the results, $Hg^{2+}$-induced aquation of 3,2,3-tet system has been produced cis-${\beta}$ complex via trans complex. The kinetic studies on $Hg^{2+}$-induced aquation of trans-[Co(3,2,3-tet)$Cl_2]^+$ complex and trans-[Co(3,2,3-tet)$(NO_2)Cl]^+$ complex were also carried out to study the reaction mechanism. The results show that trans-[Co(3,2,3-tet)$Cl_2]^+$ complex undergoes the D(dissociative)-mechanism and trans-[Co(3,2,3-tet)$(NO_2)Cl]^+$ complex $I_d$(interchange dissociavite)-mechanism. In order to confirm steric course for the reaction mechanism, $Hg^{2+}$-induced aquation on trans-[Co(R,R-3,2,3-tet)$Cl_2]^+$ complex to which chiral R,R-3,2,3-tet was coordinated instead of the racemic(R,R:S,S) 3,2,3-tet was used has been examined by CD spectrum. From the results, the final complex was confirmed to be ${\Delta}-cis-{\beta}$-[Co(R,R-3,2,3-tet)$(OH_2)_2]^{3+}$ complex indicating the chirality was retained through whole process.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.3
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• pp.640-658
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• 1996

The purpose of this study was to examine the mechanism of improving acid resistance of Nd-YAG laser irradiated tooth enamel and determine the most effective energy density for improving acid resistance. The bovine tooth enamel were lased with a pulsed Nd-YAG laser. The energy densities of exposed laser beam were varied from 10 to $70\;J/cm^2$. To investigate the degree of improving acid resistance by irradiation, all the samples were submerged to demineralize in 0.5 N $HClO_4$ solution for 1 minute. After 1 minute, 0.05 % $LaCl_3$ was added to the solution for interrupting the demineralization reaction. The amounts of dissolved calcium and phosphate in the solution were measured by using an atomic absorption spectrophotometer and the UV/VIS spectrophotometer, respectively. To examine the mechanism of improving acid resistance, X-ray diffraction analysis, infrared spectroscopy, and scanning electron microscopy were taken. The X-ray diffraction pattern of the samples were obtained in the $10^{\circ}{\sim}80^{\circ}2{\theta}$ range with $Cu-K{\alpha}$ radiation using M18HF(Mac Science Co.) with X-ray diffractometer operating at 40 KV and 300 mA. The infra-red spectra of the ground samples in 300 mg KBr pellets 10 mm diameter were obtained in the $4000cm^{-1}\;to\;400cm^{-1}$ range using JASCO 300E spectrophotometer. The scanning electron microscopy was carried out using JSM6400(JEOL Co.) with $500{\sim}2000$ times magnification. The results were as follow 1. The concentration of calcium dissolved from laser irradiated enamel with $50J/cm^2$ was significantly lesser than that of unlased control group (p<0.05) 2. From the result of the X-ray diffraction analysis, $\beta$-TCP, which increases acid solubility, was identified in lased enamel but the diffraction peaks of (002) and (004) became sharp with increasing energy density of laser irradiation. This means that the crystals in lased samples were grown through the c-axis and subsequently, the acid solubility of enamel decreased. 3. The a-axis parameter was slightly increased by laser irradiation, whereas the c-axis parameter was almost constant except for a little decrease at $50J/cm^2$. 4. In the infra-red spectra of lased enamels, phosphate bands ($600{\sim}500cm^{-1}$), B-carbonate bands (870, $1415{\sim}1455cm^{-1}$), and A-carbonate band ($1545cm^{-1}$) were observed. The amounts of phosphate bands and the B-carbonate bands were reduced, on the other hand, the amount of the A-carbonate band was increased by increase the energy density. 5. The SEM experiments reveal that the surface melting and recrystallization were appeared at $30J/cm^2$ and the cracks were observed at $70J/cm^2$. From above results, It may be suggested that the most effective energy density for improving acid resistance of tooth enamel with the irradiation of Nd-YAG laser was $50J/cm^2$. The mechanism of improving acid resistance were reduction of permeability due to surface melting and recrystallization of lased enamel and reduction of acid solubility of enamel due to decrease of carbonate content and growth of crystal.

• Journal of Life Science
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• v.25 no.1
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• pp.53-61
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• 2015

In this study, we tried to separate the photosensitizer that induces apoptosis of leukemia cells (U937) from perilla leaves. Perilla leaves (Perilla frutescens Britt var. japonica Hara) are a popular vegetable in Korea, being rich in vitamins (A and E), GABA, and minerals. Dried perilla leaves were extracted with methanol to separate the photosensitizer by various chromatographic techniques. The structure of the isolated compound (PL9443) was identified by 1D-NMR, 2D-NMR, and FAB-mass spectroscopy. Absorbance of the UV-Vis spectrum was highest at 410 nm and was confirmed by the 330, 410, and 668 nm. PL9443 compound was determined to be pheophorbide, an ethyl ester having a molecular weight of 620. It was identified as a derivative compound of pheophorbide structure when magnesium comes away from a porphyrin ring. Observation of morphological changes in U937 cells following cell death induced by treated PL9443 compound revealed representative phenomena of apoptosis only in light irradiation conditions (apoptotic body, vesicle formation). Results from examining the cytotoxicity of PL9443 substance against U937 cells showed that inhibition rates of the cell growth were 99.9% with the concentration of 0.32 nM PL9443. Also, the caspase-3/7 activity was 99% against U937 cells with the concentration of 0.08 nM of PL9443 substance. The result of the electrophoresis was that a DNA ladder was formed by the PL9443. The PL9443 compound is a promising lead compound as a photosensitizer for photodynamic therapy of cancer.

• Journal of Food Hygiene and Safety
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• v.24 no.4
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• pp.291-298
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• 2009

This study was carried out to evaluate the consumer recognition with regard to the safety management for imported foods. In order to evaluate the effect of the prgram on consumer education, the program was practiced for 89 female college students in Seoul, Korea. The participants were given an instruction with materials on imported food safety, including the safety management of imported foods and their distribution. The results showed that the participants achieved a greater understanding of imported foods. In particular, they had firmly grasped the importance of expiration date in selecting imported foods. Before the instruction, 50.6% of total participants blamed the Korean government for the problems arising from imported foods; only 18.0% placed the blame on individuals or businesses importing from foreign countries. After the instruction, 39.3% had blamed the individuals or businesses importing from foreign countries. Furthermore, 36.0% had disapproved of the foods that are imported from China before the instruction, while 32.6% found objectionable the views on the illegally distributed foods; 29.2% criticized the junk foods that target children (after the instruction). In addition, the level of participant satisfaction via-a-vis imported foods safety supervision had improved from $2.76{\pm}1.59$(before the instruction) to $3.37{\pm}1.58$(after the instruction). The results indicate that consumers are concerned with the imported foods that contain adulterated or forbidden substances and the illegally distributed foods from foreign countries. Thus, consistent and informative educational programs on imported food safety could help consumers in choosing safer products, resulting in an improvement in the consumer confidence with respect to imported foods.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.327-336
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• 2019

Soybean is one of the most important crops of which the grains contain high protein content and has been consumed in various forms of food. Soybean plants are generally cultivated on the field and their yield and quality are strongly affected by climate change. Recently, the abnormal climate conditions, including heat wave and heavy rainfall, frequently occurs which would increase the risk of the farm management. The real-time assessment techniques for quality and growth of soybean would reduce the losses of the crop in terms of quantity and quality. The objective of this work was to develop a simple model to estimate the growth of soybean plant using a multispectral sensor mounted on a rotor-wing unmanned aerial vehicle(UAV). The soybean growth model was developed by using simple linear regression analysis with three phenotypic data (fresh weight, dry weight, leaf area index) and two types of vegetation indices (VIs). It was found that the accuracy and precision of LAI model using GNDVI (R²= 0.789, RMSE=0.73 ㎡/㎡, RE=34.91%) was greater than those of the model using NDVI (R²= 0.587, RMSE=1.01 ㎡/㎡, RE=48.98%). The accuracy and precision based on the simple ratio indices were better than those based on the normalized vegetation indices, such as RRVI (R²= 0.760, RMSE=0.78 ㎡/㎡, RE=37.26%) and GRVI (R²= 0.828, RMSE=0.66 ㎡/㎡, RE=31.59%). The outcome of this study could aid the production of soybeans with high and uniform quality when a variable rate fertilization system is introduced to cope with the adverse climate conditions.

• Analytical Science and Technology
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• v.8 no.3
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• pp.321-334
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• 1995

Basic studies for the effective extraction of ammonium pyrrolidine dithiocarbamate(APDC) complexes of Co(II), Ni(II) and Cu(II) into a solvent have been performed. The maximum distribution ratio was appeared (log D=1.3543) at pH 2.0 and the partition coefficient was 2.489 in the extraction of $4{\times}10^{-5}M$ APDC itself into chloroform. From the UV/visible spectra of metal-chelates in aqueous and organic solutions, the pH to form stable 1:2 metal-ligand complexes were Co(II):5.0, Ni(II):8.0 and Cu(II):8.0, respectively and only 1 minute was enough to be partitioned into the chloroform. Besides, the partition and extraction equilibria of the complexes were investigated by back-extracting $10.0{\mu}g/ml$ metal-chelates from the solvent into an aqueous solution beacuse of their slight solubilities in the aqueous solution. The distribution coefficients and extractabilities were as follows : at pH 6.5~8.5 of the aqueous solution, log D=2.834 : E(%)=99.9% for $Co(PDC)_2$, at pH 11, log D=5.699 E%=100 for $Ni( PDC)_2$, and at pH 6.0, log D=2.025 : E(%)=99.1% for $Cu(PDC)_2$. And the extraction and formation constants were log $K_{ex}=9.671$ : log ${\beta}_2=6.938$ for $Co(PDC)_2$, log $K_{ex}=9.646$ : log ${\beta}_2=7.071$ for $Ni( PDC)_2$, and log $K_{ex}=9.074$ : log ${\beta}_2=7.049$ for $Cu(PDC)_2$, respectively. From these results, an optimum extraction procedure can be constructed for the separative concentration of trace metallic ions, and the quantitative determination of them in advanced materials and environmental samples will be expected without any influence of sample matrixes.