• Biomedical Science Letters
• /
• v.3 no.2
• /
• pp.151-160
• /
• 1997

This study was planned to evaluate the urinary ascorbic acid as a new biological marker for the intoxication of cadmium, which could possibly be driven by its increased utilization and environmental pollution. In order to meet this goal, we have peformed measurement of urinary ascorbic acid concentration, histopathological examination of the kidney, and biochemical test for the liver function using cadmium-intoxicated rats by oral administration. The average concentrations of urinary ascorbic acid in the $CdCl_2$-treated rats were 214.0 mg/dl for 100 ppm group and 254.3 mg/dl for 200 ppm group during experimental period of 50 days. These levels are 24 and 28 times higher than one in the control group (9.0 mg/dl), respectively. Ultrastructural study showed the eosinophilic hyaline cast and focal effacement, fusion in the renal tubules, as well as loss of foot processes on the glomerular epithelial cells. These results suggested that cadmium may be responsible for renal glomerular injury. The blood levels of AST, ALT and LDH in the treated groups (199 IU/I, 88 IU/I, 1190 U/I for the 100 ppm group and 270 IU/I, 226 IU/I, 760 U/I for the 200 ppm group) were higher than ones in the control group(143 IU/I, 50 IU/I, 334 U/I). These results indicated the cadmium induced the damage of liver function. In conclusion, the administration of cadmium showed a remarkable increase of urinary ascorbic acid with renal and hepatic damage. Therefore, it is expected that measurement of urinary ascorbic acid would be an powerful method as a noninvasive biomarker for cadmium intoxication.

• Korean Journal of Environmental Agriculture
• /
• v.21 no.3
• /
• pp.208-215
• /
• 2002

This study was carried out to evaluate the pollutant removal efficiencies of the advanced drinking water treatment using activated carbon process. for raw water, Nakdong river was used. from the activated carbon adsorption experiment the fellowing results were obtained The efficiency of water treatment enhanced with increase in empty bed contact time. Variation of pH was not detected to the bed depth, but DO content gradually decreased with the bed depth. Removal efficiency of $KMnO_4$ consumption, UV254 absorption, DOC and THMFP also were increased by increasing in the bed depth. Transition of adsorption zone from upper parts of the bed to the lower parts were detected as treatment periods increased. Large portion of DOCs were degraded and removed by the microbes growing on the surface of activated carbons. Cell numbers of microbes were estimated over $1.1\times10^7\;cell/cm^3$ at the depth of 20 cm from the surface 126 days after starting operation. The results shown that the activated carbon Inter was successfully acted as a biofilm filter.

• Journal of Aquaculture
• /
• v.20 no.1
• /
• pp.65-72
• /
• 2007

Full length complementary DNA encoding apolipoprotein A-I (apoA-I) was isolated and characterized in mud loach (Misgurnus mizolepis). Mud loach apoA-I cDNA encoding 24 bp of 5'-untranslated region (UTR), 762 bp of single open reading frame (ORF) consists of 254 amino acids and 293 bp of 3'-UTR excluding stop codon and poly (A+) tail. Two overlapping polyadenylation signals (AATAAAATAAA) was found 9 bp prior to the poly (A+) tail. Mud loach apoA-I represented considerable homology to those from other teleost species at amino acid level with conserving common features of vertebrate apoA-I. Molecular phylogenetic analysis inferred the phylogenetic hypothesis that was generally in accordance with the previous taxonomic relationship. Apolipoprotein A-I mRNA was detected in various tissues, but the mRNA levels were quite varied depending on tissues based on semi-quantitative RT-PCR. Liver and brain showed the significantly higher levels of apoA-I transcripts than other tissues. mRNA expression of apoA-I was quite low in very early stage of embryonic development, however dramatically enhanced from 8 hours post fertilization. This increased mRNA level was retained consistently up to 14 days post hatching.

• The Korean Journal of Mycology
• /
• v.39 no.3
• /
• pp.239-242
• /
• 2011

Eritadenine, a potent compound of hypocholesterolemic activity, was investigated in relation to its content in domestic cultivars and wild types of shiitake (Lentinula edodes). Eighteens strains of shiitake were tested for the quantification of eritadenine by LC-MS/MS analysis. Among the strains, wild type-40 was highest as the content was 3.912 mg/g. Also, Soohyangko was 3.352mg/g, Sanlim No. 9 3.008mg/g, Chunbaegko 2.832 mg/g, Gaeulhyang and KFRI 675 both 2.792 mg/g as high-content strains. Soohyangko and Chunbaegko are applied strains for registration in 2010. Soohyangko is high-temperature type with concentrated fruiting, and 90% of production occurs in the first year, thus, recovery of cost is very fast. Chunbaegko is mid-temperature type with concentrated flushing, and produces "hwago", the best quality, in spring. Wild type-40 is excellent in productivity and is prepared for registration. Wild type-40 could be used as parent strain to make new strain with high eritadenine content.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.17 no.5
• /
• pp.368-372
• /
• 1984

This paper deals with a rapid method for determination of ATP and its related compounds in fish and shellfish products using high performance liquid chromatography(HPLC). The HPLC used is a HPLC/ALC-224 equiped with UV-spectrophotometer (254 nm) as detector and integrator (Yanagimoto system-1000). The column used is a stainless steel tubing ($30.0\;cm{\times}3.9\;mm\;i.d.$) packed with ${\mu}-Bon-dapak\;C_{18}$. A mixture of $1\%$ triethylamine-phosphoric acid(pH6.5) was used as an eluent and the flow rate of the eluent was controlled at 2 ml/min. For the separation of ATP and its related compounds, a standard mixture of ATP, ADP, AMP, IMP, inosine and hypoxanthine was subjected to HPLC under the above mentioned conditions. Six peaks were obtained with retention times within 20 min, and elution order were hypoxanthine, IMP, inosine, AMP, ADP and ATP. But 5'-IMP and 5'-GMP fractions were not separated by this method. In generally, IMP content in boiled-dried fish and shellfish products purchased from the market was comparatively higher than that of other nucleotides. Especially, boiled-dried big eye herring marked higher value in IMP content than other boiled-dried ones. Hypoxanthine and inosine were major components of ATP-related compounds in dried products and seasoned-dried ones. And IMP content in seasoned-dried products was higher than that of dried ones. This fact is suggested that a part of IMP in seasoned-dried ones was derived from flavoring matter (MSG, 5'-IMP and 5'-GMP) which is added during the seasoning treatment.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.2
• /
• pp.254-262
• /
• 2016

With the increased demand for automotive radar systems, mutual interference between vehicles has become a crucial issue that must be resolved to ensure better automotive safety. Mutual interference between frequency modulated continuous waveform (FMCW) radar system appears in the form of increased noise levels in the frequency domain and results in a failure to separate the target object from interferers. The traditional fast fourier transform (FFT) algorithm, which is used to estimate the beat frequency, is vulnerable in interference-limited automotive radar environments. In order to overcome this drawback, we propose a high-resolution frequency estimation technique for use in interference environments. To verify the performance of the proposed algorithms, a 77GHz FMCW radar system is considered. The proposed method employs a high-resolution algorithm, specially the multiple signal classification and estimation of signal parameters via rotational invariance techniques, which are able to estimate beat frequency accurately.

• Korean Journal of Environmental Biology
• /
• v.36 no.4
• /
• pp.672-679
• /
• 2018

This study was conducted to predict the potential distribution and risk of invasive alien plant, Amaranthus patulus, in an agricultural area of South Korea. We collected 254 presence localities of A. patulus using field survey and literature search and stimulated the potential distribution area of A. patulus using maximum entropy modeling (MaxEnt) with six climatic variables. Two different kinds of agricultural risk index, raster risk index and regional risk index, were estimated. The 'raster risk index' was calculated by multiplying the potential distribution by the field area in $1{\times}1km$ and 'regional risk index' was calculated by multiplying the potential distribution by field area proportion in the total field of South Korea. The predicted potential distribution of A. patulus was almost matched with actual presence data. The annual mean temperature had the highest contribution for distribution modeling of A. patulus. Area under curve (AUC) value of the model was 0.711. The highest regions were Gwangju for potential distribution, Jeju for 'raster risk index' and Gyeongbuk for 'regional risk index'. This different ranks among the index showed the importance about the development of various risk index for evaluating invasive plant risk.

• The korean journal of orthodontics
• /
• v.41 no.4
• /
• pp.237-254
• /
• 2011

Objective: The purpose of this study was to compare the displacement patterns shown by finite element analysis when the maxillary anterior segment was retracted from different orthodontic miniscrew positions and different lengths of lever arms in lingual continuous and segmented arch techniques. Methods: A three dimensional model was produced, the translation of teeth in both models was measured and individual displacement was calculated. Results: When traction was carried out from miniscrews in the palatal slope, lingual tipping of crowns and extrusion of the maxillary anterior segment were found in both continuous and segmented arches as the lever arms were made shorter. With miniscrews in the midpalatal suture area, the displacement patterns were similar to the palatal slope, but bodily movement of the upper incisors was observed in both continuous and segmented arches with the lever arm at 20 mm. When lever arms were longer, there was less extrusion of the incisors and more buccal displacement of the canines. Such displacement was shown less in the continuous arch than the segmented arch. The second premolar showed crown mesial tipping and intrusion, and the molars showed distal tipping in the continuous arch. The posterior segment was displaced three dimensionally in the segmented arch, but the amount of displacement was less than the continuous arch. Conclusions: It is recommended that lever arms of 20 mm in length be used for bodily movement of the anterior segment. Use of continuous or segmented arches affect the displacement patterns and induce differences in the amount of displacement.

• Journal of the Korean Solar Energy Society
• /
• v.32 no.spc3
• /
• pp.245-254
• /
• 2012

In photovoltaic system, the characteristics of photovoltaic module such as open circuit voltage and short circuit current will be changed because of cell temperature and solar radiation. Therefore, the boost converter of a PV system connects between the output of photovoltaic system and DC link capacitor of grid connected inverter as controlling duty ratio for maximum power point tracking(MPPT). This paper shows the dynamic characteristics of the boost converter by comparing single-loop and two-loop control algorithm using both analog and digital control. Both proposed compensation methods have been verified with computer simulation to demonstrate the validity of the proposed control schemes.

• Journal of Korean Society for Atmospheric Environment
• /
• v.20 no.5
• /
• pp.593-601
• /
• 2004

In this study, we are going to compare the chemical composition of the precipitation that falls in the Dangjin and Anmyon-do areas by analyzing the water soluble components (anion and cation). We also examined the effects of seasonal change and regional difference in those data sets. The [$NO_3\;^- \;+\;SO_4\;^{2-}$] at 49.2${\mu}$eq/l is 67% of the total anion of 73.1${\mu}$eq/l, while that of [$NH_4\;^+\;+\;Ca^{2+}$] at 37.7${\mu}$eq/l is 62% of the cation in Dangjin area. Also, the [$NO_3\;^-\;+\;SO_4\;^{2-}$] concentration of 151.8 (${\mu}$eq/l) is 62% for the total anion of 143.5 (${\mu}$eq/l), and the [$NH_4\;^+\;+\;Ca^{2+}$] concentration of 119.7 (${\mu}$eq/l) is 47% for the cation of 254.3 (${\mu}$eq/l) in Anmyon-do area. The ion composition ratio is shown for the order by 22% of $SO_4\;^{2-}$, 20.8% of $NH_4\;^+$ and 15.4% of $Cl^-$ that is the sum of 58.7% for the total ion composition in Dangjin area, and is the order by 33.8% of $NH_4\;^+$, 16.3% of $SO_4\;^{2-}$ and 11.1% of $Cl^-$ in Anmyon-do area. Furthermore, We predicted that even areas which were previously clean will get acid rain if there is large scale construction there or nearby.