Search Results

You are looking at 1 - 10 of 19 items for

  • Author or Editor: Sun Kim x
  • All content x
Clear All Modify Search

Abstract  

Separation of lithium isotope by NTOE compound was carried out with 0.01M HCl solution. The ion exchange capacity of NTOE was 0.8 meq/g. The separation factor, α=(7Li/6Li)solid(7Li/6Li)liquid was 1.0242 by the elution chromatography. The lighter isotope,6Li was concentrated in the liquid phase, while the heavior isotope,7Li was enriched in the solid phase.

Restricted access
Scientometrics
Authors: F. Lancaster, Sun-Yoon Kim Lee, and Catalina Diluvio

Abstract  

Two separate studies have looked at the question of whether or not the sources cited by scientists when they publish in their own national journals differ somewhat from the sources they cite when they publish outside their own country. Data derived from studies of Philippine scientists and Korean mathematicians do suggest that place of publication may exert some influence on citation behavior. In particular, a scientist is more likely to cite national sources when publishing in a national journal than when publishing internationally.

Restricted access

Abstract  

The organometallic precursor of fac-[99mTc(CO)3(H2O)3]+ has attracted much attention because of the robustness and small size of Tc(I)-tricarbonyl complexes compared to Tc(V) complexes and the good labeling affinity with a variety of donor atoms. Among various ligand systems, an iminodiacetic acid (IDA) was proven as a good chelating group to form a Tc(III)-compelx as well as has been shown its potential as a chelating system for fac-[99mTc(CO)3] precursor. In an attempt to confirm the similarity and the difference between 99mTc(CO)3-IDA and 99mTc-(IDA)2-complex, M(CO)3-IDA (M = 99mTc, Re) complexes of disofenin, mebrofenin and N-(3-iodo-2,4,6-trimethyl phenylcarbamoylmethyl) iminodiacetic acid were prepared, and the biological evaluation of 99mTc(CO)3-disofenin was performed. The 99mTc(CO)3-IDA complexes were prepared with a high radiolabeling yield (>98%) in a quantitative manner and showed a negative charge. The in vivo pharmacokinetic behavior of 99mTc(CO)3-disofenin showed a similar biological activity to 99mTc-(disofenin)2 in that those complexes were quickly cleared from the blood by the hepatocytes and excreted into the gallbladder and intestine. Accordingly, the 99mTc(CO)3-IDA derivatives of disofenin and mebrofenin might be used as hepatobiliary imaging agents. Since an IDA is a promising chelator for 99mTc-based radiopharmaceutical and the biological properties of 99mTc(CO)3-IDA derivative shows similar to that of 99mTc-complex, a biomolecule containing IDA can be freely radiolabeled with fac-[99mTc(CO)3]-precursor or 99mTc. However, the radiolabeling efficiency and the biological behavior demonstrates the favorable properties of 99mTc(CO)3-IDA compound for the development of a new imaging agent.

Restricted access

Abstract  

The analysis of mineral contents in space foods is needed to obtain an information on a comprehensive elemental composition as well as the investigation on the effects of human nutrition and health based on the dietary intake of mineral elements. Recently, six items of new Korean space foods (KSFs) such as kimchi, bibimbap, bulgogi, a ramen, a mulberry beverage and a fruit punch which was developed by the KAERI, and the contents of more than 15 elements in the samples were examined by using instrumental neutron activation analysis (INAA). Five biological certified reference materials, NIST SRM were used for analytical quality control. The results were compared with those of common Korean foods reported, and these results will be applied toward the identification of irradiated foods.

Restricted access

Abstract  

The aim of the research is to find out better medicinal stuff for thyroid cancer patients who are required to have a low level iodine diet. Iodine contents in 12 kinds of oriental herbal medicinal prescriptions, which are frequently used for thyroid cancer patients, are determined using instrumental neutron activation analysis. The biological certified reference material was used for analytical quality control. The relative errors and standard deviations for the iodine analysis were less than 2.88 and 18.5%, respectively. The level of iodine contents for four medicinal samples detected was in the range of about 3–210 mg/kg, the concentrations of eight samples were estimated from the detection limit under the given analytical conditions. In addition, the informative concentrations of 17 essential elements with special functions such as Al, As, Ba, Br, Ca, Cl, Cr, Fe, K, Mg, Mn, Na, Rb, Sr, Ti, V, and Zn in the samples were also determined together with their detection limits for data inter-comparison. The relative errors and standard deviations for these elements were in the range of 0.1–18.0%, and 2–20%, respectively.

Restricted access

Abstract

Background and aims: Several studies have suggested that addictive disorders including substance abuse and pathologic gambling might be associated with dysfunction on working memory and prefrontal activity. We hypothesized that excessive online game playing is associated with deficits in prefrontal cortex function and that recovery from excessive online game playing might improve prefrontal cortical activation in response to working memory stimulation. Methods: Thirteen adolescents with excessive online game playing (AEOP) and ten healthy adolescents (HC) agreed to participate in this study. The severity of online game play and playing time were evaluated for a baseline measurement and again following four weeks of treatment. Brain activation in response to working memory tasks (simple and complex calculations) at baseline and subsequent measurements was assessed using BOLD functional magnetic resonance imaging (fMRI). Results: Compared to the HC subjects, the AEOP participants exhibited significantly greater activity in the right middle occipital gyrus, left cerebellum posterior lobe, left premotor cortex and left middle temporal gyrus in response to working memory tasks during baseline measurements. After four weeks of treatment, the AEOP subjects showed increased activity within the right dorsolateral prefrontal cortex and left occipital fusiform gyrus. After four weeks of treatment, changes in the severity of online game playing were negatively correlated with changes in the mean β value of the right dorsolateral prefrontal cortex in response to complex stimulation. Conclusions: We suggest that the effects of online game addiction on working memory may be similar to those observed in patients with substance dependence.

Open access

Tobacco rattle virus (TRV-K) was first identified in a symptomatic Gladiolus plant cultivated in Korea. We analyzed the TRV-K genome and compared its phylogeny with other TRV isolates. After constructing of a full-length genomic RNA2 strand clone, a complete sequence was generated from several overlapping clones. The cloned genome was 3261 bases in length, identical to TRV-K, and had three open reading frames. TRV-K had the highest sequence identity with the American isolate TRV-ORY. Sequence analysis of the RNA2 genome showed that TRV-K contains an intact 2a, 2b, and 2c coding sequence and an RNA1-related 3′ terminus, which is typical of TRV RNA2. Phylogenetic analysis revealed that TRV-K is in the same cluster as the American isolates and another Korean isolate, TRV-SK; however, it was in a different cluster than the European isolates.

Restricted access

Abstract  

The k 0-standardization method (k 0-NAA) is known as one of the most remarkable progresses of the NAA with its many advantages. For the application of k 0-NAA method at the NAA #1 irradiation position where the neutrons are well thermalized in the HANARO research reactor, KAERI, Korea, the determination of the reactor neutron spectrum parameters such as α and f have been carried out. The measured values of α and f using the “Cd-ratio” triple monitor method were 0.127±0.022 and 1010±70, respectively. To evaluate the applicability of k 0-NAA in our analytical system, the analysis of three kinds of SRMs was executed. The analytical results showed that the relative error of most of the elements was less than 10% and the U-scores were within 2. It is turned out that the procedure of the k 0-NAA in the HANARO research reactor is available for a practical application in the environmental fields.

Restricted access

Abstract  

To enhance the applicability of the nuclear analytical technique in the field of industry and the environment, the inorganic elemental content of the bottom ash from a municipal solid waste incinerator was determined by instrumental neutron activation analysis. Bottom ash samples were monthly collected from an incinerator located at a metropolitan city in Korea, strained through a 5 mm sieve, dried by an oven and pulverized by an agate mortar. The samples were irradiated at the NAA #1 irradiation hole (thermal neutron flux: 2.92·1013 n·cm−2·s−1) in the HANARO research reactor of the Korea Atomic Energy Research Institute and the irradiated samples were measured by a HP Ge gamma-ray spectrometer. Thirty-three elements including As, Cr, Cu, Fe, Mn, Sb and Zn were analyzed by an absolute method. The quality control was conducted by a simultaneous analysis with NIST standard reference materials. The average concentrations of the major elements such as Ca, Fe, Al, Na, Mg, K and Ti measured in the sample were 19.9%, 4.85%, 3.79%, 2.11%, 1.84%, 1.22% and 1.02%, respectively. In addition, the concentrations of the hazardous metals like Zn, Cu, Cr, Sb and As were 0.77%, 0.31%, 729 mg·kg−1, 116 mg·kg−1 and 22.2 mg·kg−1, respectively.

Restricted access

Abstract  

For air pollution monitoring, about 1300 airborne particulate matter samples were collected by using a low volume air sampler and a polycarbonate filter at two sampling sites in an urban region, Daejeon, the middle of Korea from 2003 to 2006. Mass concentrations of the black carbon were measured using a smoke stain reflectometer. The concentrations of 24 elements in the collected samples were analyzed by using instrumental neutron activation analysis, and its temporal trends and enrichment factors were investigated under different environmental conditions. Analytical control was carried out by using certified reference materials.

Restricted access