• Journal of the Korean Chemical Society
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• v.43 no.3
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• pp.280-285
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• 1999

Separation of plutonium species was studied by ion chromatography installed in a glove box for the determination of plutonium element. The plutonium species, $PuO_2^{2+},\; PC^{4+}\; and\; Pu^{3+}$, were stably separated on dynamically equilibrated cation exchanger using 1-octanesulfonate and ${\alpha}$-HiBA eluant after controlling the plutonium oxidation states with KI, $NaNO_2\;or=;KBrO_3$ based on the oxidation-reduction potentials. For the separation of plutonium from other matrix, $PuO_2^{2+}\; and\; Pu^{4+}$ were reduced to $Pu^{3+}$ with KI and $NaNO_2$ followed by cation exchange chromatography.

• Publications of The Korean Astronomical Society
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• v.20 no.1 s.24
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• pp.43-48
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• 2005

We present a high resolution spectrum of PU Vul observed at Bohyunsan Optical Astronomy Observatory (BOAO) on April 9, 2004. Permitted emission and nebular lines of PU Vul had been significantly changed compared to all spectra observed since its eruption in 1979. Therefore all new lines should be re-identified and were done so. We do-convoluted a $H{\beta}$ line into several emission components with Gaussian functions. Then we carefully discussed the geometrical feature of PU Vul in April 2004.

• Fibers and Polymers
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• v.4 no.2
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• pp.49-53
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• 2003

Polyurethane (PU) layer and copolymer consisted of the different molecular weights (1000 and 2000 g/mol) of poly(propylene glycol) (PPG) were prepared. The damping and mechanical properties of these materials were compared with PU 1000 made by PPG having the molecular weight of 1000 g/mol. The optimum composition of PU2000 used for PU layer and copolymer was diphenylmethane diioscynate (MDI)/propylene glycol (PPG)/butanediol (BD) (1/0.3/0.7) based on the damping and mechanical properties. The damping peak of PU copolymer was higher than those of PU layer and PUI 1000 in low temperature range (-30- $10^{\circ}C$). For application in noise reduction, the transmission loss of the mechanical vibration through solid structure was measured. PU layer and copolymer were used as a damping layer. The transmission loss of PU copolymer was more effective than those of PU layer and PU 1000 in the experimental frequency range.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.9
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• pp.3667-3671
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• 2015

Invasion and metastasis is the major cause of tumor recurrence, difficulty for cure and low survival rate. Excavating key transcription factors, which can regulate tumor invasion and metastasis, are crucial to the development of therapeutic strategies for cancers. PU.1 is a master hematopoietic transcription factor and a vital regulator in life. Here, we report that, compared to adjacent non-cancerous tissues, expression of PU.1 mRNA in metastatic hepatocellular carcinoma (HCC), but not primary HCC, was significantly down-regulated. In addition, levels of PU.1 mRNA in metastatic hepatoma cell lines MHCC97L and MHCC97H were much lower than in non-metastatic Hep3B cells. Transwell invasion assays after PU.1 siRNA transfection showed that the invasion of hepatoma cell lines was increased markedly by PU.1 knockdown. Oppositely, overexpression of PU.1 suppressed the invasion of these cells. However, knockdown and overexpression of PU.1 did not influence proliferation. Finally, we tried to explore the potential mechanism of PU.1 suppressing hepatoma cell invasion. ChIP-qPCR analysis showed that PU.1 exhibited a high binding capacity with miR-615-5p promoter sequence. Overexpression of PU.1 caused a dramatic increase of pri-, pre- and mature miR-615-5p, as well as a marked decrease of miR-615-5p target gene IGF2. These data indicate that PU.1 inhibits invasion of human HCC through promoting miR-615-5p and suppressing IGF2. These findings improve our understanding of PU.1 regulatory roles and provided a potential target for metastatic HCC diagnosis and therapy.

• KSBB Journal
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• v.10 no.5
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• pp.499-509
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• 1995

PU.1, a tissue-specific transcription activator, binds to a purine-rich sequence(5'-GAGGAA-3') called PU box. The PU.1 cDNA consists of an open reading frame of 816 nucleotides coding for 272 amino acids. The amino terminal end is highly acidic, while the carboxyl terminal end is highly basic. Transcriptional activation domain is located at the amino terminal end, while DNA binding domain is located at the carboxyl terminal end. Activation of PU.1 transcription factor is supposed to be accomplished by the phosphorylation of serine residue(s). There exist 22 serines in the PU.1. Five(the 41, 45, 132$.$133, and 148th) of the serines(plausible phosphorylation site by casein kinase II), are the primary targets of interest in elucidating the molecular mechanism(s) of the action of the PU.1 gene. In this study, PU.1 cDNA coding for the five serine residues(41th AGC, 45th AGC, 132$.$133th AGC$.$TCA, and 148th TCT), was mutated to alanine codon(41th GCC, 45th GCC, 132$.$133th GCC$.$GCA, and 1481h GCT), respectively, by Splicing-Overlapping-Extension(SOE) using Polymerase Chain Reaction(PCR). And each mutated cDNA fragments was ligated into pBluescript KS＋ digested with HindIII and Xba I, to generate mutant clones named pKKS41A, pRKS45A, pMKS132$.$133A, and pMKS148A. The clones will be informative to study the "Structure and Function" of the immu-nologically important gene, PU.1.

• Analytical Science and Technology
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• v.14 no.1
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• pp.28-33
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• 2001

The ion chromatography for the separation of plutonium species which are suggested to be $Pu^{3+}$, $Pu^{4+}$, $PuO_2{^+}$ and $PuO_2{^{2+}}$ in natural water was studied. Two separation methods were performed; 1) two-column method containing each of $SiO^-$ and SiO-$SO_3{^-}$ cation exchanger, 2) IC with AG11 column and the eluent of oxalate/nitric acid. Separation conditions for $Eu^{3+}$, $Th^{4+}$, $NpO_2{^+}$, $UO_2{^{2+}}$ in place of plutonium species were acquired from preliminary tests. When these conditions were applied to separate the plutonium species, two-column method was separated them successfully. However, the IC method with oxalate eluent was difficult in the separation of plutonium species due to the change of $Pu^{3+}$ and $PuO_2{^{2+}}$ to $Pu^{4+}$ and $PuO_2{^+}$ respectively.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.21 no.1
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• pp.55-64
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• 2023

There is a gap in our understanding of the behavior of fused and molten fuel salts containing unavoidable contamination, such as those due to fabrication, handling, or storage. Therefore, this work used calorimetry to investigate the change in liquidus temperature of PuCl₃, having an unknown purity and that had been in storage for several decades. Further research was performed by additions of NaCl, making several compositions within the binary system, and summarizing the resulting changes, if any, to the phase diagram. The melting temperature of the PuCl₃ was determined to be 746.5℃, approximately 20℃ lower than literature reported values, most likely due to an excess of Pu metal in the PuCl₃ either due to the presence of metallic plutonium remaining from incomplete chlorination or due to the solubility of Pu in PuCl₃. From the melting temperature, it was determined that the PuCl₃ contained between 5.9 to 6.2mol% Pu metal. Analysis of the NaCl-PuCl₃ samples showed that using the Pu rich PuCl₃ resulted in significant changes to the NaCl-PuCl₃ phase diagram. Most notably an unreported phase transition occurring at approximately 406℃ and a new eutectic composition of 52.7mol% NaCl-38.7mol% PuCl₃-2.5mol% Pu which melted at 449.3℃. Additionally, an increase in the liquidus temperatures was seen for NaCl rich compositions while lower liquidus temperatures were seen for PuCl₃ rich compositions. It can therefore be concluded that changes will occur in the NaCl-PuCl₃ binary system when using PuCl₃ with excess Pu metal. However, melting temperature analysis can provide valuable insight into the composition of the PuCl₃ and therefore the NaCl-PuCl₃ system.

• IMMUNE NETWORK
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• v.16 no.3
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• pp.176-182
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• 2016

CCR3 is a chemokine receptor that mediates the accumulation of allergic inflammatory cells, including eosinophils and Th2 cells, at inflamed sites. The regulatory sequence of the CCR3 gene, contains two Runt-related transcription factor (RUNX) 1 sites and two PU.1 sites, in addition to a functional GATA site for transactivation of the CCR3 gene. In the present study, we examined the effects of the cis-acting elements of RUNX1 and PU.1 on transcription of the gene in EoL-1 eosinophilic cells and Jurkat T cells, both of which expressed functional surface CCR3 and these two transcription factors. Introduction of RUNX1 siRNA or PU.1 siRNA resulted in a modest decrease in CCR3 reporter activity in both cell types, compared with transfection of GATA-1 siRNA. Cotransfection of the two siRNAs led to inhibition in an additive manner. EMSA analysis showed that RUNX1, in particular, bound to its binding motifs. Mutagenesis analysis revealed that all point mutants lacking RUNX1- and PU.1-binding sites exhibited reduced reporter activities. These results suggest that RUNX1 and PU.1 participate in transcriptional regulation of the CCR3 gene.

• Nuclear Engineering and Technology
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• v.21 no.4
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• pp.277-286
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• 1989

Destructive methods are used for the turnup determination of an irradiated PWR fuel. One of the methods includes U, Pu, Nd-148 and Nd-(145+146) determination by an isotope dilution mass spectrometry using triple spikes (U-233, Pu-242 and Nd-150). The method involves two sequential ion exchange resin separation procedures. Pu is eluted from the first anion exchange resin column (Dowex AG 1$\times$8) with 12 M HCl-0.1 M HI mixed solution, followed by U elution with 0.1 M HCl. Nd is isolated from other fission products on the second anion exchange resin column (Dowex AG 1$\times$4) with a nitric acid-methanol eluent. Each fraction is analysed by thermal ionization mass spectrometry. The difference between Nd-148 and Nd-(145+146) method is found with an average 2.07%. The results are compared with those by the heavy element method using U and Pu isotopes and by the destructive y-spectrometric measurement of Cs-137. The dependences of isotope composition of U and Pu on burn-up, and correlation between those isotopes are illustrated graphically.

• Applied Chemistry for Engineering
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• v.21 no.1
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• pp.46-51
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• 2010

Polyorganosiloxane modified polyurethane (PDMS-PU) polymers were prepared from copolymerization of ${\alpha}$,${\omega}$-hydroxypropyl terminated polyorganosiloxane with isophorone diisocyanate (IPDI), polypropylene glycol (PPG), and 2,2-bis(hydroxymethyl) propionic acid (DMPA). Hydrophobic polyorganosiloxane was introduced in polyurethane main chain as soft segment block unit. The isocyanate groups in PDMS-PU block copolymer was blocked with 2-butanon oxime and obtained PDMS-PU dispersions in water by neutralizing with triethylamine (TEA). The deblocking temperature of PDMS-PU polymer was measured from thermal analysis. The good stability of the PDMS-PU dispersion was obtained by dispersing into water. PDMS-PU prepolymers were prepared with various contents of DMPA under [NCO]/[OH] = 1.12~1.53 equivalent ratio. Increasing DMPA from 7.2, 13.4, and 18.7 mole% in preparation of PDMS-PU polymer, particle sizes were decreased from 156, 100, 65 dnm. Also contact angle and adhesive strength were measured.