• Economic and Environmental Geology
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• v.39 no.3 s.178
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• pp.213-227
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• 2006

The geochemical evolution of mine drainage and leachate from waste rock dumps and stream water in Pb-As-rich abandoned Sechang mine area was investigated to elucidate mechanisms of trace metals. Total and sequential extractions were applied to estimate the distribution of trace metals in constituent phases of the waste rocks and to assess the mobility of trace metals according to physicochemical conditions. These discharged waters varied largely in chemical composition both spatially and temporally, and included cases with significant]y low pH (in the range 2.1-3.3), and extremely sulphate (up to 661 mg/l and metal contents (e.g. up to 169 mg/l for Zn, 27 mg/l for As, 3.97 mg/l for Pb, 2.99 mg/l for Cu, and 1.88 mg/l for Cd). Arsenic and heavy metal concentrations at the down-stream of Sechang mine have been decreased nearly to the background level in downstream sites (sites 8 and 16) without any artificial treatments. The oxidation of Fe-sulfides and the subsequent hydrolysis, of Fe(II), with precipitation of poorly crystallized minerals, constituted an efficient mechanism of natural attenuation which reduces considerably the transference of trace metals (i.e. Fe and As) to rivers. The dilution of drainage by mixing with pristine waters provoked an additional decrease of trace metal concentrations and a progressive pH increase. On the other hand, the most soluble cations (i.e. Zn) remained significantly as dissolved solutes until the pH was raised to approximately neutral values. With respect to ecotoxicity, it is likely that the Zn pollution is of particular concern in Sechang mine area. This was confirmed by the sequential extraction experiment, where Zn in wet waste-rock samples occurred predominantly in the exchangeable fraction (65-89% of total), while Pb was the highest in the reducible and carbonate fractions, and Cd, Cu and As in the residual fraction. Pb concentration in the readily available exchangeable fraction (34-48% of total) was dominated for dried waste rock samples. Considering the proportion of metals bound to the exchangeable and carbonate fractions, the comparative mobility of metals probably decreased in the order of Zn>Pb>Cd>As=Cu.

• The Korean Journal of Nuclear Medicine
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• v.3 no.2
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• pp.17-22
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• 1969

The differences in the change of the uptake rate of radioactive iodine ($^{131}I$) in the thyroid gland after $Tapazole^{(R)}$ administration before $^{131}I$ treatment were analysed in 137 patients who were diagnosed as diffuse toxic goiter in the Radioisotope Clinic and Laboratory, Seoul National University Hospital since Jan. 1967 to July, 1969. The uptake rate of the therapeutic dose of $^{131}I$ was changed diffusely compared with that of the trace dose in the patients who had no $Tapazole^{(R)}$ administration before $^{131}I$ treatment. In those patients who had $Tapazole^{(R)}$ more than 20 mg/day for more than one week before $^{131}I$ treatment, the uptake rate was decreased significantly. When the patients discontinued the administration of $Tapazole^{(R)}$ 7 days prior to $^{131}I$ treatment, the uptake rate was increased in all cases.

• Asian Journal of Atmospheric Environment
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• v.6 no.3
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• pp.234-243
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• 2012

The wintertime high loading for atmospheric pollutants is certainly expected in the Byunsan Peninsula of Korea because of a great-scale reclamation project having construction of 33 km tidal sea dike impounding an area of over 40,000 ha and long-range transport. The goal of this study is to trace the origin of this wintertime burden for ambient particulate matter (hereafter called "PM") in the Byunsan Peninsula of Korea. The size-segregated (i.e., cutoff size from 0.01 ${\mu}m$ to 4.7 ${\mu}m$) PM sampling was conducted at a ground-based site of Byunsan Peninsula located in the west coast of Korean Peninsula during the height of dike constructing. Data archived in this study are the mass concentrations of ionic, elemental, and carbonic components in size-fractioned PM. The elemental mass of individual submicrometer particles was also analyzed. The sum of 5-source (i.e., elemental carbon, organic materials, inorganic secondary pollutants, crustal matter, and sea-salts) concentrations shows the bimodal distribution (major and minor peaks formed around $D_p$, 0.65 ${\mu}m$ and $D_p$, 4.7 ${\mu}m$, respectively) by border with 0.19 ${\mu}m$ of cutoff size. The concentrations of EC in $PM_{1.1-0.01}$ in winter and spring times were 4.62 ${\mu}g\;m^{-3}$ and 3.74 ${\mu}g\;m^{-3}$, respectively. Elemental masses of submicron individual particles are classified into two groups, i.e., the major elements (Cl, Al, Si, S, and P) and the minor trace elements. Cluster analysis differentiated the elements in submicron individual particles into 4-cluster. Among them, three clusters are in agreement with the major (Al, Si, S, and P), minor (Fe, Ca, and K), and trace compositions of coal burning. Meanwhile, Cl classified as an independent cluster has different source profile which was mainly due to the Saemangeum seawall project. Some highly toxic elements (e.g., Cr, Mn, and As (and/or Pb)) were also detected in some part of submicron individual PM. As a consequence, the combination of the Saemangeum project and winter monsoon played a considerable part in the double aggravation of wintertime air pollution in the Byunsan Peninsular.

• Analytical Science and Technology
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• v.15 no.4
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• pp.365-372
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• 2002

In this study, inorganic elemental distribution in Korean adult human tissue of liver, lung, muscle, kidney, rib and thyroid has been investigated. These tissues were collected from human's body within 48 hours after their death according to IAEA's recommended method, dried by freeze drying method and then pulverized. Neutron activation analysis was applied to these samples to determine the concentrations of 5 major elements of Ca, Mg, Na, K, and Cl and 12 trace elements of Mn, I, Sr, As, Br, Co, Cr, Cs, Fe, Rb, Se, and Zn. To confirm accuracy of analytical result was performed using three kinds of standard reference materials and resulted that the relative error is within 10% for the most of elements and the Z-score indicating a performance of analysis is within 2. The elemental distribution shows that the major elements are distributed homogeneously with a specific concentration and that the trace elements shows a distribution of different concentration with kinds of tissue and their age. Particularly, iodine shows higher concentration with 1000 ${\mu}g/g$ in thyroid, and calcium and strontium show the concentration with 15.9% and 84.4 ${\mu}g/g$ in rib, respectively.

• Journal of Plant Biology
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• v.38 no.2
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• pp.137-141
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• 1995

We isolated a cDNA clone, BLSC1, encoding 5' exon of ATP synthase CF0 subunit I from broccoli. BLSC1 is 285 nucleotides long which consists of a 5' noncoding region of 34 nucleotides, a 5' exon of 145 nucleotides and an intron of 106 nucleotides. The 5' exon codes for 48 amino acids which reveals mostly hydrophobic. The amino acid sequence deduced from BLSC1 shares 83%, 83% and 91% identities with the genes coding for atpF from wheat, rice and spinach, respectively. Genomic Southern blot analysis for BLSC1 showed a typically strong signal for a gene located in the chloroplast genome. Northern blot analysis identified three major classes of transcripts showing strong positive signals in the leaves, but only trace amounts of the transcripts were identified in the other organs like stems, flowr buds and roots.

• Journal of Animal Science and Technology
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• v.45 no.4
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• pp.543-550
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• 2003

Two experiments were conducted to determine the effects of deletion of vitamin and trace mineral premixes on growth, feed efficiency, backfat thickness, hemoglobin content, muscle vitamin E content, and fecal, serum and muscle trace mineral contents in finishing pigs raised under two different housing conditions. In Exp. 1, three pens (or experimental units) of five pigs each (average weight $\pm$ s.e., 70 $\pm$ 0.5 kg) were assigned to a control diet (with vitamin and trace mineral premixes) or diets with 50 or 100% of the premixes deleted. Pigs were fed to market weight under sub-optimal housing conditions with sawdust-covered concrete floor and no electrical ventilation. In Exp. 2, three pens of four pigs each (average weight $\pm$ s.e., 56 $\pm$ 1.1 kg) were assigned to a control (with vitamin and trace mineral premixes), Diet-P (100% of the premixes deleted) or Diet-P+E (Diet-P plus 100 mg $\alpha$-tocopherol acetate/kg diet fed for the last 2 wk before slaughter). Pigs were fed to market weight under optimal housing conditions with 70%-slatted concrete floor, electrical ventilation and temperature control. No significant differences were found in average daily gain (ADG), average daily feed intake (ADFI), and gain/feed among treatments in both experiments, but in Exp. 2 done with younger pigs, ADG and ADFI tended to be higher in the control group than in pigs fed diet without premixes. Hemoglobin content, hematocrit and red blood cell count were not influenced by the deletion of premixes. Backfat thickness was not different among treatments. Fecal Mn (twofold) and Zn (threefold) contents were higher in the control than in pigs fed diets without the premixes. Serum trace mineral contents were not influenced by diets. $\alpha$-Tocopherol content in gluteus maxima was decreased (P< 0.01) by deleting the dietary premixes, but increased to the level higher than the control by adding 100 mg $\alpha$-tocopheryl acetate/kg diet fed for the last 2 wk before slaughter. Results indicate that: 1) supplementary vitamins and trace minerals may not be necessary for optimum growth in finishing pigs, and 2) deletion of the dietary premixes reduces muscle vitamin E content, but the reduced content can be reversed by adding $\alpha$- tocopherol to diets fed for the last 2 wk before slaughter. The deletion may help to alleviate the environmental load of certain minerals from manure.

• Korean journal of applied entomology
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• v.13 no.4 s.21
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• pp.235-243
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• 1974

Recenty, the pesticides Pollutions in connection with the maintenance of dietary life are poised as serious sanitary problems. Author have established an appropriate analysis method in this connection and, at the same time, analysed the levels of pesticides residues, such as organochloride pesticides and organic mercurials, contained in main cereals (rice, barley, and wheat) collected throughout the country. Using gas liquid chromatography method, comparative analyses were made of organochloride Pesticides with electron capture detector, and organic mercurials with electron capture detector and the Dithizone Method. As a result, the organic mercurials analysis using gas liquid chromatography is believed to hold out an especially good method for both in terms of its sensitivity and its Practical applications. The summary obtained from these results is as follows; The detectable limit of organochloride pesticides is $5\times10^{-10}$ grams and that of organic mecurials is $5\times10^{-9}$ grams. The detections using the Dithizone Method are difficult. The gas liquid chromatographic analysis of organic mercurials is very simple in its operation and high in its sensitivity, compare with the analysis using the Dithizone Method. Therefore, this analysis is expected to be a good method applicable to the pesticide residues analysis. The levels of pesticide residues contained in samples are very little for tolerance and, therefore, no problem i.: foreseen for eating. The appropriate conditions of gas liquid chromatographic analysis obtained from these results are expected very useful for the date establishing an officially authorized analysis method.

• Economic and Environmental Geology
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• v.38 no.4 s.173
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• pp.451-462
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• 2005

In order to examine the extent of environmental contamination at abandoned Samsanjeil Cu mines in Kosung-kun, Kyeongsangnam-do, we have investigated the contaminations and mobility of toxic trace elements from mine wastes including about 280,000 tonnages of tailings by chemical experiments (total extraction, partial extraction by 0.1N HCI and sequential extraction procedure). Total concentrations of trace elements showed that Cu, As, Co, Zn, Pb, and Cd concentrations in tailings were 14.0, 3.6, 3.1, 2.1, 2.1 and 1.6 times greater than those in background soil, respectively. From the proportion of metals bound to the exchangeable and carbonate fractions, the comparative mobility of metals decrease in order of $Zn(29.0\%)>Cu(12.3\%)Pb(9.6\%)>Cd(3.0\%)>As=Co(0.0\%)$. Based on the concentrations, chemical speciations of tailings, waste rock and nearby soil, it was revealed that Cu and Zn were the most possible elements to contaminate the surrounding environment in Samsanjeil mine area. In addition, the tailings had total trace metal concentrations below Dutch guideline values except Cu, and they might not affect adverse impact on environment.

• Acta Via Serica
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• v.3 no.2
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• pp.73-90
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• 2018

The Silk Road tied the globe together for the first time by producing an early globalization phenomenon. Some consider that the ancient Silk Road disintegrated around the $18^{th}$ century CE due to the fall of the Muslim empires and the kingdoms between Asia and Europe. However, the maritime trade among East Asia and the Spanish dominion on the American continent reactivated the ancient Silk Road on some levels, and maintained trade dynamics until the $19^{th}$ century. This was possible because of Mexican silver and trade spots. Notwithstanding its historical background, Mexico seems so far away from the new Silk Road, or the Belt and Road Initiative in the $21^{st}$ century. Thus, this paper analyzes Mexico's historic and current role concerning the Silk Road. First, I conceptualize and compare the ancient Silk Road and Belt and Road Initiative through the lens of complex interdependence theory. I propose that, unlike the ancient Silk Road, the Belt and Road Initiative is a case of an induced complex interdependence. Second, I study the Manila Galleons' dynamics in order to trace the ancient ties with the Silk Road. I emphasize Mexican silver's contribution to East Asian economies and the importance of Mexico's role in the East Asia-Spanish trade. Consequently, I analyze Mexico's position in the Belt and Road Initiative. Finally, I present some concluding remarks about Mexico's role in the Silk Road.

• Food Science of Animal Resources
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• v.43 no.6
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• pp.989-1001
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• 2023

Processed foods containing pork fat tissue to improve flavor and gain economic benefit may cause severe issues for Muslims, Jews, and vegetarians. This study aimed to develop an indirect enzyme-linked immunosorbent assay (iELISA) based on a monoclonal antibody specific to thermal stable-soluble protein in pork fat tissue and apply it to detect pork fat tissue in heat-processed (autoclave, steam, roast, and fry) beef meatballs. To develop a sensitive iELISA, the optimal sample pre-cooking time, coating conditions, primary and secondary dilution time, and various buffer systems were tested. The change in the iELISA sensitivity with different 96-well microtiter microplates was confirmed. The detection limit of iELISA performed with an appropriate microplate was 0.015% (w/w) pork fat in raw and heat-treated beef. No cross-reactions to other meats or fats were shown. These results mean that the iELISA can be used as an analytical method to detect trace amounts of pork fat mixed in beef.