• Journal of Advanced Marine Engineering and Technology
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• v.36 no.1
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• pp.166-171
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• 2012

In this paper, short-range underwater wireless communication technique using visible LEDs is proposed. As an alternative to conventional acoustic system, visible LED communications show high quality and high speed data transmission characteristics. We design a frequency modulation-based optical wireless audio transmission system. The CD4046B phase-locked loop device is applied to implement the frequency modulation and demodulation. With a transmission modulation of 100 kHz, audio signal has successfully received at a transmission distance of 30 cm.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.6
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• pp.485-494
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• 1992

This study dealt with the concentration of heavy metals in mussels, Mylitus edulis and oysters, Crassostrea gigas, in different habitats around the Korean coastal waters during 1985-1989. The high levels of heavy metal concentration in two bivalves were found at Station 1, 2, 5, 23 and 25, while the low levels were found at stations in Chinhae Bay. Oysters were more effective bioaccumulators of Cu, Zn and Hg than mussels showing the ratios of 16:1 for Cu, 1.63:1 for Cd, 1.36:1 for Pb, 7.61:1 for Zn and 2.08:1 for Hg. The larger mussels were, the higher the concentrations of five metals.

• Kidney Research and Clinical Practice
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• v.36 no.2
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• pp.200-204
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• 2017

Administration of autologous mesenchymal stem cells (MSCs) has been shown to improve renal function and histological findings in acute kidney injury (AKI) models. However, its effects in chronic kidney disease (CKD) are unclear, particularly in the clinical setting. Here, we report our experience with a CKD patient who was treated by intravenous infusion of autologous MSCs derived from adipose tissue in an unknown clinic outside of Korea. The renal function of the patient had been stable for several years before MSC administration. One week after the autologous MSC infusion, the preexisting renal insufficiency was rapidly aggravated without any other evidence of AKI. Hemodialysis was started 3 months after MSC administration. Renal biopsy findings at dialysis showed severe interstitial fibrosis and inflammatory cell infiltration, with a few cells expressing CD34 and CD117, 2 surface markers of stem cells. This case highlights the potential nephrotoxicity of autologous MSC therapy in CKD patients.

• Journal of Veterinary Clinics
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• v.36 no.2
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• pp.119-122
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• 2019

The prevailing discipline notes that primary pulmonary angiosarcoma is an extremely rare malignant tumor with almost grave prognosis when presented in a dog. No cases have been reported earlier as occurring in dogs. This is the first time we are reporting a case of primary lung angiosarcoma in a 12-year-old Yorkshire terrier breed dog, that will explore the clinical as well as histopathological features of the tumor as noted in a dog. In this case, radiography revealed a well-defined large soft tissue mass in the caudo-dorsal lung field across the left hemi-thorax. After necropsy, it is noted that the lung was found to have the blood-filled nodular lesions on its surface, as determined with no such lesions on other organs. Upon the histological examination, it showed the presence of an extensive necrotic hemorrhage with anastomosing vascular space. Later, the immunohistochemistry showed strongly positive CD31 cells confirming the endothelial origin of the tumor. This is the first report of canine primary lung angiosarcoma in the Republic of Korea.

• Journal of Korean Academy of Nursing
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• v.37 no.3
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• pp.313-323
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• 2007

Purpose: Health-related quality of life (HRQOL) in patients with cardiovascular disease in Korea has rarely been studied, mostly due to the lack of a psychometrically validated disease-specific instrument. The purpose of this study was to develop and validate a cardiovascular specific-HRQOL questionnaire (CD-QOL). Method: The CD-QOL was developed and validated as follows; item generation, pilot study, and psychometric tests. Patients were recruited from three-university hospitals. The patients were asked to complete the preliminary questionnaire comprising the content-validated items, SF-36, and CES-D. The NYHA and KASI classifications were used to classify the functional performance of the patients. The data was analyzed using correlation, factor analysis, multidimensional scaling, multitrait/multi-item matrix, ANOVA, and Cronbach's alpha. Result: Preliminarily, thirty-nine items were generated. Factor analysisextracted a five-factor solution with a total of twenty-two items. One item was deleted based upon the MDS. The remaining items were moderately correlated with the subscales of the SF-36 and associated with depression measured with the CES-D. The mean scores of patients in NYHA and KASI class I were significantly higher than those in NYHA and KASI class II or/and III, which suggested patients with better functional performance were likely to have a better HRQOL. Cronbach's alphas of the total and subscales were all greater than 0.70. Conclusion: The CD-QOL is a easily applicable instrument with excellent psychometric properties of content, criterion, factorial, convergent, and known-groups validity, and internal consistency reliability in Korean patients with cardiovascular disease.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.342-346
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• 2003

This study was conducted to examine the contents of heavy metals in beverages and to estimate their intakes. The contents of lead (Pb), cadmium (Cd), arsenic (As), and tin (Sn) were determined in a total of 207 samples of beverages using atomic absorption spectrophotometer(AAS) and inductively coupled plasma spectrometer(ICP). Also a mercury analyzer was utilized for analysis of mercury. The values of heavy metals in beverages were as follows [min-max (mean), mg/kg]; Hg 0.0001-0.0025 (0.0004), As ND-0.0245 (0.0003), Pb ND-0.089 (0.004), Cd ND-0.006 (0.001), Sn ND-45.36 (1.97). Our results were similar to those reported by other countries. Our weekly intakes of heavy metals from beverages take $0.01%{\sim}0.06%$ of PTWI (Provisional Tolerable Weekly Intake) established by FAO/WHO.

• Journal of Pharmaceutical Investigation
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• v.31 no.3
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• pp.151-160
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• 2001

The purpose of this study is to investigate the interaction of progesterone with various cyclodextrins (CDs) in the aqueous solution and in solid state, and finally to formulate a parenteral aqueous formulation. CDs used were ${\alpha}-$, ${\beta}-$, and ${\gamma}-CD$, $2-hydroxypropyl-{\beta}-CD$ (HPCD), sulfobutyl $ether-{\beta}-CD$ (SBCD), $dimethyl-{\beta}-CD$ (DMCD) and $trimethyl-{\beta}-CD$ (TMCD). The solubility studies of progesterone were performed in the presence of various CDs as a function of concentration or temperature. The solubility of progesterone increased in the rank order of ${\alpha}-CD$ < ${\beta}-CD$ < ${\gamma}-CD$ < TMCD$ < HPCD < DMCD < SBCD. Addition of SBCD (200 mg/ml) in water increased the aqueous solubility $(9.36\;{\mu}g/ml)$ about 3,200 times, and lowering the temperature facilitated the solubilization of progesterone. However, the addition of HPCD and SBCD in 20:80 (v/v) polyethylene glycol 300-water and propylene glycol-water cosolvents markedly decreased the solubility of progesterone, compared with solubilizing effects in water. Physical mixtures and solid dispersions of progesterone with HPCD or SBCD were prepared, and evaluated by differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), near IR spectroscopy and dissolution studies. By DSC and IR studies, it was found that progesterone was dispersed in HPCD in monotectic state and dissolved rapidly from both solid dispersions. Based on solubility studies, new aqueous progesterone fonnulations (5 mg/ml) containing SBCD (200 mg/ml) could be prepared and did not form precipitates even after 2 months at $4^{\circ}C$. The solution was transparent when mixed with normal saline and 5% dextrose injection at 1: 1, 1:10 and 1:20 (v/v) even after 7 days. Permeation rates of progesterone through a cellulose membrane from 20% PEG 300 solution $(50\;{\mu}g/ml)$ containing HPCD or SBCD were compared with oily formulation. Permeation of progesterone from oily formulation did not occur up to 8 hr, but aqueous formulations showed fast permeation rates from early stage of permeation study. The addition of HPCD or SBCD retarded the permeation rates of progesterone with the increase of CD concentrations, suggesting the possibility of a controlled absorption from the site administered intramuscularly. These results demonstrate that it is feasible to develop a new progesterone parenteral aqueous injection (5 mg/ml) using SBCD.

• Economic and Environmental Geology
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• v.36 no.5
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• pp.357-363
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• 2003

The objective of this study is to investigate background levels of As and heavy metals (Cd, Cu, Pb and Zn) and their dietary intakes from white rice produced at various provinces in Korea during 2000. Except Jeju-do, sixty-three rice grain samples were taken at 8 provinces and analyzed for the elements using ICP-AES after acid digestion. The average contents of hi, Cd, Cu, Pb and Zn in the samples were 0.126, 0.040, 1.96, 0.361 and 16.6 mg/kg(DW), respectively. These levels are within the ranges of worldwide average concentrations in rice grains reported by various research. Assuming the rice consumption of 256 g/day by overall households in Korea, the amount of daily intake of As, Cd, Cu, Pb and Zn by the rice were estimated to be 32.3, 10.2, 502, 92.4 and 4,250 ${\mu}g$/day, respectively. Those amount of daily intakes of the elements by the rice are within the WHO's guide for trace elements, however, rice consumption is one of the most important sources of dietary intake of As and some heavy metals in Korean population.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.523-526
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• 2004

There are few studies on toxic metals in fruits. Therefore, we examined contents of toxic metals in fruits (n=386) available in Korean markets. The samples were digested with acids, then analyzed by inductively coupled plasma spectrometer (ICP) or atomic absorption spectrophotometer (AAS) for lead (Pb), cadmium (Cd), and arsenic (As). The contents of mercury (Hg) were also determined using a mercury analyzer, Contents of toxic metals in fruits were as follows [minimum-maximum (mean), mg/kg]; Hg 0.0001-0.019 (0.001), Pb 0.001-0.410 (0.013), Cd 0.001-0.035 (0.000), and As 0.001-0.210 (0.017). Our results showed that metal contents in fruits in Korean markets were similar to those reported in other countries. Average weekly intakes of Hg, Pb, and Cd from fruits are about 1-2% of Provisional Tolerable Weekly Intakes (PTWI) set by FAO/WHO Joint Food Additive and Contaminants Committee for safety evaluation.

• Environmental Analysis Health and Toxicology
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• v.19 no.4
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• pp.383-388
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• 2004

In order to elucidate the relationships between cadmium, copper, mercury, zinc levels and metallothionein in the liver and kidney cortex of Korean, the levels of Cd, Zn, Hg, Cu and metallothionein (MT) were determined in the kidney cortex and liver of 50 subjects deceased in the period of January-November, 2001 in the area of Seoul and Gyeonggi Province of Korea. The mean age of the population studied was 36.3+/-12.3 years. The tissues were digested with microwave digestion system and the elements were determined by inductively coupled plasma atomic emission spectrometry. MT was determined by the Cd-hemoglobin affinity assay. The determined levels (mean+/-SD) were: 33.9+/-18.9 micrograms Cd/g wet weight; 47.5+/-12.6 micrograms Zn/g wet weight; 2.5+/-0.57 microgram Cu/g wet weight; 0.26+/-0.31 micrograms Hg/g wet weight, 4.0+/-3.1 mg MT/g wet weight in renal cortex and 2.5+/-1.9 micrograms Cd/g wet weight; 46.9+/-15.0 micrograms Zn/g wet weight; 6.2+/-2.5 micrograms Cu/g wet weight; 0.10+/-0.15 micrograms Hg/g wet weight, 0.92+/-0.57 mg MT/g wet weight in the liver. Positive relationships between Cd and MT, sum of four divalent metal and MT in the kidney cortex were observed. No other correlation was found between Cu and MT, Hg and MT, Zn and MT in either organs.