• Korean Journal of Environmental Agriculture
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• v.25 no.3
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• pp.236-246
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• 2006

In this study, we give insight into questionable results that can be encountered in the conventional sequential extraction of heavy metals (Cd, Cu, and Zn) from soils. Objectives of this study were to determine the extraction variability of exchangeable (EXC)-metals as using six different EXC-extractants commonly accepted, and to investigate selectivity problems with carbonates bound (CAB)-metal fraction, a buffered acetate (1.0 M NaOAc; pH 5.0) extractable-metal fraction, leading to erratic results in especially non-calcareous soils. The contents of EXC-metals were markedly varied with the different extractability of various EXC-metal extractants used. The contents of EXC-Cd fraction were ranged from 2.0 to 74.3% of total Cd content in all of the metal spiked soils studied. The contents of EXC-Zn fraction extracted with the different EXC-extractants were varied with soil types, which were from 0.4 to 3.9% of total Zn in the calcareous soils, from 7.6 to 17.9% in the acidic soil, and from 13.6 to 56.8% in the peat soil. However, the contents of EXC-Cu fraction were relatively similar among the applications of different EXC-meal extractants, 0.2 to 2.1 % of total Cu, in all soils tested. Also, these varied amounts of EXC-metal fractions, especially Cd and Zn, seriously impacted the contents of subsequent metal fractions in the procedure. Furthermore, the CAB-Cd, -Cu, and -Zn fractions extracted by the buffered acetate solution were in critical problem. That is, the buffered acetate solution dissolved not only CAB-metals but also metals that bound or occupied to subsequent fractions, especially OXD-metal fraction, in both calcareous and non-calcareous soils. The erratic results of CAB-fraction also seriously impacted the amounts of subsequent metal fractions. Therefore, the conventional sequential extraction should be reconsidered theoretically and experimentally to quantify the target metal fractions or might be progressively discarded.

• Current Research on Agriculture and Life Sciences
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• v.11
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• pp.81-89
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• 1993

In order to isolate a mutant which was constitutively expressed in xylA gene, Pxyl-cat-xylA fusion gene was constructed by the insertion of cat gene between xylA promoter and xylA structural gene in pEX13 contained xylA gene. The expression of cat and xylA gene from transformants of xylA mutant DH77 with plasmid pEXC131 containing Pxyl-cat-xylA fusion gene was induced by the addition of 0.4% xylose to media. This results indicated that cat and xylA gene were expressed under control of xylA promoter the presence of xylR gene. We have also isolated constitutive mutant plasmid pEXC131-39 from pEXC131 by trementment with N-methyl-N'-nitro-N-nitrosoguanidine(NTG). cat and xylA gene from pEXC131-39 were constitutively expressed without induction of xylose regardless of xylR gene. Transformants of xylR mutant DH60 with pEXC131-39 also expressed chloramphenicol resistances and xylose isomerase without induction of xylose. This result shows that mutation in region of xylA promoter might make it possible to be constitutively expressed.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.2 no.2
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• pp.84-95
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• 2016

Considerably increasing interest in using the theranostic isotopes/ isotope pairs of radiometals like $^{44/47}Sc$ and $^{64/67}Cu$ for diagnosis and/or therapeutic applications in the nuclear medicine procedures necessitates its reliable production and supply. Separation and purification of no-carrier-added (NCA) isotopes from macro quantitates of the irradiated target matrix along with other impurities is a cardinal procedure amongst several other steps involved in its production. Multitudinous methods including but not limited to liquid-liquid (solvent) extraction, extraction chromatography (EXC), ion exchange, electrodeposition and sublimation are routinely applied either solitarily or in combination for the separation and purification of radioisotopes depending on their production routes, radioisotope of interest and impurities involved. However, application of EXC though has shown promises towards the numerous separation techniques have not received much attention as far as its application prospects in the field of nuclear medicine are concerned. Advances in the recent past for application of the EXC resins in separation and purification of the several medically important radioisotopes at ultra-high purity have shown promising behavior with respect to their operation simplicity, acidic and radiolytic stability, separation efficiencies and speedy procedures with the enhanced and excellent extraction abilities. In this mini review we will be talking about the recent developments in the application and the use of EXC techniques for the separation and purification of $^{44/47}Sc$ and $^{64/67}Cu$ for medical applications. Furthermore, we will also discuss the scientific and practical aspects of EXC in the view of separation of the NCA trace amount of radionuclides.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.4
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• pp.172-186
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• 2017

Current study is a part of the efforts to assess the estuarine barrage effects on the coastal ecosystem induced by the Si flux changes. Surface sediments from Seomjin and Nakdong estuary and sediment cores from Nakdong estuary was analysed to investigate the effect of estuarine barrage on the distribution of grain size, organic matter (loss on ignition: LOI) and biogenic silica (BSi). The samples of Seomjin estuary were collected in March, 2015 and those of Nakdong estuary were collected in November, 2014. Generally, the longitudinal distribution of grain size, LOI and BSi in Seomjin estuary, natural estuary, was gradually changed. However mud (silt and clay), LOI and BSi increased from station mid-estuary where tide reaches year-round. The distribution of grain size, LOI and BSi in Nakdong estuary, however, were entirely different between inside and outside of estuarine barrage. The mud percentage and LOI were low and consistent in inside of the barrage except R05, inside of right gate, yet those of outside of the barrage were higher and varied by adjacent sluices. Mud, LOI and BSi of ND1 and ND2 decreased immediately after the construction of Nakdong estuarine barrage due to disturbance of sediment and decrease of sediment supply. To exclude the physical effects by the barrage, BSi excess ($BSi_{exc}$) was calculated using regression equation of BSi-LOI and BSi-mud of Seomjin estuary. $BSi_{exc}$ of Seomjin estuary decreased gradually from upper estuary to lower estuary. $BSi_{exc}$ of Nakdong estuary were positive in inside of the barrage and negative in outside of the barrage. BSi retention and shift of species composition of diatom by the barrage would affect $BSi_{exc}$ distribution. Before the construction of Nakdong estuarine barrage, $BSi_{exc}$ of ND2 was negative and consistent owing to high mud sedimentation. After the construction, $BSi_{exc}$ of ND2, however, fluctuated due to continuous disturbance of sediment due to construction of Eulsuk bridge and East gate.

• The Korean Nurse
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• v.6 no.5 s.31
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• pp.33-41
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• 1967

Guillain Barre Syndrome, rather rarely occuring nerve disease and its causes are usually obscure, was seriously studied through a patient admitted recently to our hospital. Bilateral ascending paralysis on both extremities without sensory loss and the exc

• Journal of Digital Convergence
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• v.16 no.1
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• pp.125-134
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• 2018

This study focused on the study of the moderating effects of absorptive capacity(AC) of venture firms on the technological innovation performance(TIP). For this purpose, this study analyzed the relationship between entrepreneurship(ENT), innovation competence(INC), external cooperation(EXO) and AC affecting the performance of technological innovation activities in venture companies in the area of Busan. As a result of analysis, the AC showed a role of moderating processes, in which ENT have affected the INC, and ENT, INC, and EXO have affected the TIP. Secondly, several relationships which have positively influenced or mediated, have been presented. ENT has positively influenced INC, EXO, & TIC. INC have done so EXC & TIP. EXC have done so TIP. Each of INC and EXC has been positively mediating the relationship between ENT & TIP.

• Bulletin of the Korean Chemical Society
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• v.8 no.1
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• pp.19-26
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• 1987

A statistical thermodynamical treatment for polymer adsorption from solution is presented. The canonical partition function for the polymer solution in the presence of a surface or an impermeable interface is formulated on the basis of usual quasi-crystalline lattice model, Bragg-Williams approximation of random mixing, and Pak's simple treatment of liquid. The present theory gives the surface excess ${\Gamma}_{exc}$ and the surface coverage ${\phi}^s_2$ of the polymer as a function of the chain length x, the Flory-Huggins parameter x, the adsorption energy parameter $x_s$, and polymer concentration $v_2$. Present theory is also applicable to the calculation of interfacial tension of polymer solution against water. For the idealized flexible polymer, interfacial tensions according to our theory fit good to the experimental data to the agreeable degrees.

• Korean Journal of Animal Reproduction
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• v.14 no.1
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• pp.31-35
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• 1990

The viability and developmental potential of rat oocyte was assessed by the use of eosin B. Dye was prepared as a stock solution to contain 1.0 mg eosin B per ml of Brinster's Medium for Ovum Culture plus glucose (BMOC) -2 medium. Three dye concentrations were selected for the Oocytes from rat ovarian follicles were collected and assessed under various conditions of heat oocyte studies by dilution of the stock solution with BMOC: 0.12mM, 0.60mM and 1.20mM. treatment and preservation duration by dye exc¬lusion assay using eosin B. It is suggested that live oocyte excludes eosin B whereas dead oocyte does not.

• Journal of Chest Surgery
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• v.25 no.8
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• pp.837-843
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• 1992

The most common deformity of the sternum is the depression deformity, variously calid pectus Excavatum, funnel chest, schwusterbrust, trichterburst, thorax en entonnoir. During the period 1983 to 1991 a total of 15 cases of funnel chest were treated surgically at Department of Thoracic Surgery, Hanyang University Hospital. The age at the time of operation ranged from 4 to 26 years 73.3 percent of the patients were under 12 years of age They all had symptoms of feeling Inferiority about chest deformity. The concavity on the funnel chest varied in its Extent, and the severity, which was measured by water volume filled into it, varied from 45ml to 100ml. We have Experienced 15 cases of pectus Exc-avatum with several operative method, i.e., Ravitch operation in 2 cases, Taguchi operation in 3 cases[using by Both IMA], Adkins operation in 5 cases, Modified wada operation [sternal costal cartilage Elevation Technique] in 5 cases. After surgery, follow up vertebral Index showed 44%, preoperatively and 29% postoperatively, average decrement of 15%. We Reported 15 cases of funnel chest and the surgical results of thease cases were satisfactory Except one case of Ravitch operation.

• The Journal of Fisheries Business Administration
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• v.40 no.3
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• pp.169-187
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• 2009

This study analyzes the long and short term effect of exchange rate on the import of Korea's fisheries focussed on main fisheries imported from China. The estimation models consist of the following contents. The first model consists of one dependent variable-import quantity of fisheries imported from China(${IMQ_t}^{CHO}$) and three independent variables-${RP_t}^{CHO}$, $EXC_t$ and $GDP_t$. The second one-one dependent variable-import quantity of fisheries imported from China(${JMQ_t}^{NAG})$ and three independent variables-${RP_t}^{NAG}$, $EX_t$ and $GDP_t$. the third one-one dependent variable-import quantity of fisheries imported from China(${IMQ_t}^{AH}$) and three independent variables-${RP_t}^{AH}$, $EX_t$ and $GDP_t$. the forth one-one dependent variable-import quantity of fisheries imported from China(${IMQ_t}^{KO}$) and three independent variables-${RP_t}^{KO)$, $EX_t$ and $GDP_t$. the last one is made up of one dependent variable-import quantity of fisheries imported from China(${IMQ_t}^{GAL}$) and three independent variables-, ${RP_t}^{GAL}$, $EX_t$ and $GDP_t$. and. The estimation results show that exchange rate of the independent variables are statistically significant in only the first model. The figure is elastic. Especially, the effect of exchange rate in first model is grater than that of the. However, the effect of exchange rate, one of independent variables in the ECM, is not statistically significant.