• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.3017-3026
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• 2022

The ¹³¹Cs radioisotope with a short half-life time and high average radiation energy can treat the cancer effectively in prostate brachytherapy. The typical ¹³¹Cs production processes have a separation step of the cesium from ¹³¹Ba to obtain a high specific radioactivity. Herein, we suggested a novel ¹³¹Cs separation method based on the Ba²⁺ adsorption of alginate beads. It is necessary to reduce the affinity of alginate beads to cesium ions for a high production yield. The carboxyl group of the alginate beads was replaced by a sulfonate group to reduce the cesium affinity while reinforcing their affinity to barium ions. The modified beads exhibited superior Ba²⁺ adsorption performances to native beads. In the fixed-bed column tests, the saturation time and adsorption capacity could be estimated with the Yoon-Nelson model in various injection flow rates and initial concentrations. In terms of the Cs elution, the modified alginate showed better performance (i.e., an elution over 88%) than the native alginate (i.e., an elution below 10%), indicating that the functional group modification was effective in reducing the affinity to cesium ions. Therefore, the separation of cesium from the barium using the modified alginate is expected to be an additional option to produce ¹³¹Cs.

• Fibers and Polymers
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• v.1 no.1
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• pp.32-36
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• 2000

An alternative strategy to .educe the percolation threshold of carbon black (CB) in polymer blends was investigated using random copolymer ternary blends of polystyrene (PS), poly(methyl methacrylate)(PMMA), and a styrene-methyl methacrylate random copolymer (SMMA). The target morphology was to selectively locate CB particles in the encapsulating layer of SMMA during melt mixing. The CB used in this study is BP-2000 from Cabot and has a strong selective affinity to PS. Even when the CB was premixed with SMMA, it moves to the PS phase during the melt mixing. However, we also observed the CB particles located at the interface between SMMA and PS phases. Through this study it is found that the interaction between polymers and CB particles is critical for selectively localizing CB particles in multi-component polymer blends. Although appropriate processing condition may retard the movement of CB particles to the polymer phase with affinity, it cannot prevent it completely and locate them to the SMMA phase, which is not thermodynamically favored. To locate CB particles in an encapsulating layer of ternary polymer blends, first of all, polymers forming it should have selective affinity to CB.

• Bulletin of the Korean Chemical Society
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• v.27 no.5
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• pp.739-743
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• 2006

Synthesis of cholic acid-based tripodal receptor (1) and its high chloride ion affinity in comparison with that of chenodeoxycholic acid (2) and lithocholic acid-based receptor (3) was achieved. Anion binding affinities of the receptors were evaluated $by\;^1H$ NMR and ITC titrations. Tripodal receptor 1 showed a selective affinity for $CI ^-$ over $Br ^-$, $I^-$, $H_2 PO _4\;^-$, and $CH _3 CO_2\;^-$. The selectivity of 1 for $CI ^-$ is about 3 times that of $Br ^-$, and 17 times that for $H_2 PO_4\;^-$.

• Biomolecules & Therapeutics
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• v.6 no.4
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• pp.337-344
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• 1998

The objective of the present study was to investigate the effect of senescence on the binding properties of muscarinic receptors in the neostriatum of young (3 months), middle-aged (18 months) and aged (33 months) male Fischer 344 x Brown Norway hybrid rats by employing direct binding of selective radiolabeled antagonists. Using the selective M, muscarinic receptor antagonist, $[^3H]$AF-DX384, as the ligand, no significant difference in the maximal receptor density (Bmax) was observed in the neostriatum among any age-groups. In contrast, with the selective M, receptor antagonist, $[^3H]$4-DAMP, a significant increase in the number of muscarinic receptors was observed in neostriatal membrane fractions prepared from the aged animals relative to that observed in the young rats. For each ligand there was no age-related change in its affinity (Kd) for the muscarinic receptors. These results indicate that the observed age-related changes in the muscarinic receptor density may not be necessarily decremuntal and depend upon the muscarinic receptor subtype examined.

• Biomolecules & Therapeutics
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• v.7 no.4
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• pp.307-314
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• 1999

The human muscarinic acetylcholine receptor (mAChR) subtypes Hml, Hm2 and Hm3 have been expressed in insect cells (Spodoptera frugiperda, Sf9) using the baculovirus expression system. Expression of relevant DNA, transcript and receptor proteins was identified by PCR, Northern blotting and [$^{3}H$]QNB binding, respectively. As assessed by [$^{3}H$]QNB binding sites, yields of muscarinic receptors in membrane preparations in this study were as about 5-20 times high as those in mammalian cells reported in previous studies. The [$^{3}H$]QNB competition binding studies with well-known subtype-selective mAChR antagonists showed that the receptors expressed in Sf9 cells retain the pharmacological characteristics expected for the ml , m2 and m3 muscarinic receptors. The ml-selective antagonist, pirenzepine, displayed a considerably higher affinity for Hml by 110-fold and 35-fold than for Hm2 and Hm3, respectively, The m2-selective methoctramine displayed a significantly higher affinity for Hm2 than for Hml and Hm3 (10- and 26-fold, respectively). p-F-HHSiD exhibited high affinity for Hm3 that is not significantly different from those for Hml, but 66-fold higher than its affinity for Hm2. The functional coupling of the recombinant receptors to second messenger systems was also examined. While both Hml and Hm3 stimulated phosphoinositide hydrolysis upon activation by carba-chol, Hm2 produced no response. On the other hand, activation of mAChRs induced the inhibition of forsko-lin-stimulated cyclic AMP formation in Hm2-expressing cells, whereas the significant dose-dependent increase in or poor response on cyclic AMP formation were produced in Hml or Hm3-expressing cells, respectively. These results indicate the differential coupling of recombinant Hml, Hm2 and Hm3 receptors expressed in SF9 cells to intracellular signalling system.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.1
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• pp.83-92
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• 2019

Advertising signboards are designed for the visibility to affects recall and recognition of costumers. It is well know that the visibility from images is created by the value difference among colors. The research defines whether the background color combination of outdoor signboards is configured to maximize visibility, by a series of color value variation in complex commercial facilities. The subject of study is to examine how the visibility is made by the color combination since visibility cannot be obtained independently. Two steps of analysis were performed to confirm that the color composition of signboards was based on the color value difference. The first is to analyze that the entire colors of signboards are clearly categorized as different value groups. All components of colors, hue, value and chroma had been analyzed by color aesthetic measures to prove that the value variation has the only regularity and the principle of composition. The second step is a further verification with an ample amount of samples to determine whether series of signboards create a value altering pattern. The data for analysis is gained by colorimetric survey and the color data are used for exponentializing the degree of combining, which shows selective affinity between each pair colors.

• Nuclear Engineering and Technology
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• v.46 no.6
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• pp.847-856
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• 2014

Spent resin waste containing a high concentration of $^{14}C$ radionuclide cannot be disposed of directly. A fundamental study on selective $^{14}C$ stripping, especially from the IRN-150 mixed bed resin, was carried out. In single ion-exchange equilibrium isotherm experiments, the ion adsorption capacity of the fresh resin for non-radioactive $HCO_3{^-}$ ion, as the chemical form of $^{14}C$, was evaluated as 11mg-C/g-resin. Adsorption affinity of anions to the resin was derived in order of $NO_3{^-}$ > $HCO_3{^-}{\geq}H_2PO_4{^-}$. Thus the competitive adsorption affinity of $NO_3{^-}$ ion in binary systems appeared far higher than that of $HCO_3{^-}$ or $H_2PO_4{^-}$, and the selective desorption of $HCO_3{^-}$ from the resin was very effective. On one hand, the affinity of $Co^{2+}$ and $Cs^+$ for the resin remained relatively higher than that of other cations in the same stripping solution. Desorption of $Cs^+$ was minimized when the summation of the metal ions in the spent resin and the other cations in solution was near saturation and the pH value was maintained above 4.5. Among the various solutions tested, from the view-point of the simple second waste process, $NH_4H_2PO_4$ solution was preferable for the stripping of $^{14}C$ from the spent resin.

• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.874-880
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• 2010

A series of 13- and 14-membered cyclic enkephalin analogs based on the moderately $\mu$ selective prototype compound Tyr-C[D-$A_2bu$-Gly-Phe-Leu] 8a were synthesized to investigate the structure-activity relationship. The modifications of sequence were mainly focused on two positions 3 and 5, critical for the selective recognition for $\mu$ and $\delta$ opioid receptors. The substitution of hydrophobic $Leu^5$ with hydrophilic $Asp^5$ derivatives led to Tyr-C[D-$A_2bu$-Gly-Phe-Asp(N-Me)] 7 and Tyr-C[D-Glu-Phe-gPhe-rAsp(O-Me)] 5, the peptides with a large affinity losses at both $\mu$ and $\delta$ receptors. The substitution of $Phe^3$ with $Gly^3$ led to Tyr-C[D-Glu-Gly-gPhe-rLeu] 3 and Tyr-C[D-Glu-Gly-gPhe-D-rLeu] 4, the peptides with large affinity losses at $\mu$ receptors, indicating the critical role of phenyl ring of $Phe^3$ for $\mu$ receptor affinities. One atom reduction of the ring size from 14-membered analogs Tyr-C[D-Glu-Phe-gPhe-(L and D)-rLeu] 6a, 6b to 13-membered analogs Tyr-C[D-Asp-Phe-gPhe-(L and D)-rLeu] 1, 2 reduced the affinity at both $\mu$ and $\delta$ receptors, but increased the potency in the nociceptive assay, indicating the ring constrain is attributed to high nociceptive potency of the analogs. For the influence of D- or L-chirality of $Leu^5$ on the receptor selectivity, regardless of chirality and ring size, all cyclic diastereomers displayed marked $\mu$ selectivity with low potencies at the $\delta$ receptor. The retro-inverso analogs display similar or more active at $\mu$ receptor, but less active at $\delta$ receptor than the parent analogs.

• Applied Chemistry for Engineering
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• v.5 no.2
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• pp.305-312
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• 1994

The fed-batch process which combinded high selectivity of affinity chromatography and membrane process was developed. The mixture of trypsin and chymotrypsin, having almost the same molecular weight and the chemical structure, were used as model enzymes. The water soluble polymer having more affinity for trypsin and celluose acetate membrane gelated in 50vol.% ethanol for removing free enzymes and retentating trypsin-affinity polymer complex simutaneously were used in this system. The membrane pore size was controlled by ethanol concentration in the gellation bath, and the affinity polymer was prepared by polymerization of acrylamide with N-acryloyl-m-aminobenzamidine at $4^{\circ}C$. The trypsin could be effectively concentrated by utilizing an affinity polymer and a prepared UF-50 ultrafiltration membrane. As a result, 86% purity trypsin was recovered by the current purification process.

• Journal of the Korea Convergence Society
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• v.9 no.2
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• pp.191-200
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• 2018

In this study, the relationship between selective attribute and socio-maturity was found to be statistically significant in cooking major of cooking high school students. The selective attribute of cooking major influenced the affinity of members and the selective factor of cooking major was social Affecting the management of self - esteem and self - efficacy. The selection process of cooking major affects the superior adaptability of school life. The results of this study are as follows. First, the relationship between the social maturity and the satisfaction of the majors of the cooking major students was statistically significant in the hypothesis of the model, and the member relational affinity and social intimacy influenced the participation of the curriculum model And social maturity influenced social intimacy.