Development of additive [¹¹C]CO₂ target system in the KOTRON-13 cyclotron and its application for [¹¹C]radiopharmaceutical production

Moon, B.S.,Lee, H.J.,Lee, W.K.,Hur, M.G.,Yang, S.D.,Lee, B.C.,Kim, S.E. North-Holland Physics Pub 2015 Nuclear instruments & methods in physics research. Vol.356 No.-

The KOTRON-13 cyclotron, which was developed in South Korea for the production of medical radioisotopes, has the structural limitation of only one beam-output port, restricting the production of the carbon-11 isotope. In the present study, we investigate the design of a switchable target system and develop an effective carbon-11 target in the KOTRON-13 cyclotron, for combination with the fluorine-18 target. The target system was designed by introducing a sliding-type element between the fluorine-18 and carbon-11 targets, a tailor-made C-11 target and its cooling system. For the efficient production of [<SUP>11</SUP>C]CO<SUB>2</SUB>, the desirable target shape and internal volume were determined by a Stopping and Range of Ions in Matter (SRIM) simulation program, and the target grid was modified to resist the cavity pressure during beam irradiation. We evaluated the [<SUP>11</SUP>C]CO<SUB>2</SUB> production while varying the material and thickness of the target foil, oxygen content of the nitrogen gas, and target loading pressure. Using sliding-type equipment including an additional gate valve and a high vacuum in a beam line, the bi-directional conversion between the fluorine-18 and carbon-11 targets was efficient regarding the accurate beam irradiation on both targets. The optimal [<SUP>11</SUP>C]CO<SUB>2</SUB> production for 30min irradiation at 60μA (86.6+/-1.7GBq in the target at EOB) was observed at a thickness of 19μm with HAVAR® material as a target foil and a target loading pressure of 24bar with nitrogen plus 300ppb of oxygen gas. Additionally, the coolant cavity system in the target grid and target chamber is useful to remove the heat transferred to the target body by the internal convection of water and thereby ensure the stability of the [<SUP>11</SUP>C]CO<SUB>2</SUB> production under a high beam current. In the application of C-11 labeled radiopharmaceuticals such as [<SUP>11</SUP>C]PIB, [<SUP>11</SUP>C]DASB, [<SUP>11</SUP>C]PBR28, [<SUP>11</SUP>C]Methionine and [<SUP>11</SUP>C]Clozapine, the radiochemical yields were shown to be 25-38% (decay corrected) with over 166GBq/μmol of specific activity. Consequently, the additive carbon-11 target system was successfully developed in only one output port of the KOTRON-13 cyclotron and exhibited the stable production of C-11 labeled radiopharmaceuticals.

H₂ pressure swing adsorption for high pressure syngas from an integrated gasification combined cycle with a carbon capture process

Moon, D.K.,Lee, D.G.,Lee, C.H. Applied Science Publishers 2016 APPLIED ENERGY Vol.183 No.-

<P>The integrated gasification combined cycle (IGCC) process, possessing high efficiency and environmental advantages, produces H-2-rich syngas at high pressures (30-35 bar) after capturing CO2. Since the syngas pressure is very high for conventional PSA processes, development of an efficient PSA process at the pressure conditions is required for H-2 production. In this study, the H-2 PSA process for IGCC syngas was developed experimentally and theoretically. Breakthrough and PSA experiments using activated carbon or activated carbon/zeolite LiX were performed at 25-35 bar by using a five-component hydrogen mixture (H-2:CO:N-2:CO2:Ar = 88:3:6:2:1 mol%) as a simulated syngas. The overall PSA performance was evaluated in terms of the purity, recovery and productivity of H-2 product. According to the results from using single or layered beds, the two-bed PSA process produced 99.77-99.95% H-2 with 73.30-77.64% recovery experimentally. A four-layered bed PSA at 35 bar was able to produce 99.97%-purity H-2 with 79% recovery, and it contained Ar and N-2 impurities. The quality of tail gas from the PSA process could be used for the gas turbine without losing H-2 and CO. A rigorous mathematical model that included mass, energy, and momentum balances was employed to elucidate the dynamic behaviors and separation performance of the adsorption bed and PSA process. (C) 2016 Elsevier Ltd. All rights reserved.</P>

Application of a New Portable Microscopic Somatic Cell Counter with Disposable Plastic Chip for Milk Analysis

Moon, J.S.,Koo, H.C.,Joo, Y.S.,Jeon, S.H.,Hur, D.S.,Chung, C.I.,Jo, H.S.,Park, Y.H. American Dairy Science Association 2007 Journal of dairy science Vol.90 No.5

The somatic cell count (SCC) is one of the international standards for monitoring milk quality, and it is a useful indicator of mastitis. The current reference method for determining the SCC in raw milk is direct microscopic analysis, but this method requires well-trained staff to maintain its accuracy and reproducibility. To overcome these inconveniences, we developed a portable system (the C-reader system) that utilizes the capillary flow of a microfluidic chamber by surface modification of the hydrophilicity. The microfluidic technology of disposable microchips allows for low consumption of reagents, and a combination of ready-to-use reagents makes the daily work easier. The repeatability test of the C-reader using 10 composite bovine milk samples satisfied the recommended values for SCC equipment. In addition, an acceptable accuracy level of the natural logarithmic-transformed SCC [ln(SCC/1,000):+/-0.059 to 0.112] was achieved using composite raw milk samples and various somatic cell standard solutions from the American Eastern Laboratory and the Korean National Veterinary Research and Quarantine Service. After testing 875 composite milk samples, the C-reader showed a high correlation coefficient (R<SUP>2</SUP>0.935 to 0.964) and a low mean difference value in log-transformed SCC (-0.088 to 0.004) compared with 3 automatic commercialized somatic cell counters (Fossomatic 4000, Somacount 150, and Somascope). In conclusion, the C-reader system is a new, easy-to-use automatic on-farm method with acceptable repeatability and accuracy for measuring SCC in large dairies and smaller laboratories.

Comprehensive study on critical role of surface oxygen vacancies for 2DEG formation and annihilation in LaAlO3/SrTiO3 heterointerfaces

Moon, S. Y.,Moon, C. W.,Chang, H. J.,Kim, T.,Kang, C. Y.,Choi, H. J.,Kim, J. S.,Baek, S. H.,Jang, H. W. Springer Science + Business Media 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.2

<P>Here we report comprehensive study of 2DEG at a-LAO/STO interfaces in comparison with 2DEG at crystalline LaAlO3 (c-LAO)/STO interfaces. We observe that the oxygen deficient environment during the deposition of LAO overlayer is essentially required to create 2DEG at LAO/STO interface regardless of growth temperature from 25 degrees C to 700 degrees C, indicating that the oxygen-poor condition in the system is more important than the crystallinity of LAO layer. The critical thickness (2.6 nm) of 2DEG formation at a-LAO/STO heterostructure is thicker than (1.6 nm) that at c-LAO/STO. Upon ex-situ annealing at 300 degrees C under 300 mTorr of oxygen pressure, 2DEG at a-LAO/STO interface is annihilated, while that in c-LAO/STO interface is still maintained. With combing these findings and scanning transmission electron microscope (STEM) analysis, we suggest that oxygen vacancies at the LAO surface is attributed to the origin of 2DEG formation at the LAO/STO and the crystallinity of the LAO overlayer plays a critical role in the annihilation of 2DEG at a-LAO/STO interface rather than in the formation of 2DEG. This work provides a framework to understand the importance of prohibiting the LAO surface from being oxidized for achieving thermally stable 2DEG at a-LAO/STO interface.</P>

A new class of COX-2 inhibitor, rutaecarpine from Evodia rutaecarpa

Moon, T. C.,Murakami, M.,Kudo, I.,Son, K. H.,Kim, H. P.,Kang, S. S.,Chang, H. W. 영남대학교 약품개발연구소 2000 영남대학교 약품개발연구소 연구업적집 Vol.10 No.-

Objective and Design: We investigated the effect of a new class of COX-2 inhibitor, rutaecarpine, on the production of PGD, in bone marrow derived mast cells(BMMC) and PGE_(2) in bone marrow derived mast cells (BMMC) and PGE_(2) in COX-2 transfected H다293 cells. Inflammation was induced by λ-carrageenan in male Splague-Dawley(SD) rats. Material: Rutaecarpine(8, 13-Dihydroindolo[2', 3':3,4]pyridol[2,1-b]quinazolin-5(7H)-one) was isolated from the fruits of Evodia rutaecarpa. BMMC were cultured with WEHI-3 conditioned medium. c-Kit ligand and IL-10 were obtained by their expression in baculovirus. Methods: The generation of PGD_(2) and PGE_(2) were determined by their assay kit. COX-1 and COX-2 protein and mRNA expression was determined by BMMC in the presence of KL, LPS and IL-10. Treatment: Rutaecarpine and indomethacin dissolved in 0.1% carboxymethyl cellulose was administered intraperitoneally and, 1h later, λ-carrageenan solution was in-jucted to right hind paw of rats. Paw volumes were measured using plethysmometer 5h after λ-carrageenan injection. Results: Rutaecarpine inhibited COX-2 and COX-1 dependent phases of PGD_(2) generation in BMMC in a concentration-dependent manner with an IC_(50) of 0.28 μM and 8.7μM, respectively. It inhibited COX-2-dependent conversion of exogenous arachidonic acid to PGE_(2) in a dose-dependent manner by the COX-2-transfected HEK293 cells. However, rutaecarpine inhibited neither PLA_(2) and COX-1 activity nor COX_(2) protein and the mRNA expression up to the concentration of 30μM in BMMC, indicating that retaecarpine directly inhibited COX-2 activity. Furthermore, rutaecarpine showed in vivo anti-inflammatory activity on rat λ-carrageen-an induced paw edema by intraperitoneal administration. Conclusion: Anti-inflammatory activity of Evodia rutaecarpa could be attributed at least in part by inhibition of COS-2.

Hafnium carbide protective layer coatings on carbon/carbon composites deposited with a vacuum plasma spray coating method

Yoo, H.I.,Kim, H.S.,Hong, B.G.,Sihn, I.C.,Lim, K.H.,Lim, B.J.,Moon, S.Y. Elsevier Science Publishers 2016 Journal of the European Ceramic Society Vol.36 No.7

A pure hafnium-carbide (HfC) coating layer was deposited onto carbon/carbon (C.C) composites using a vacuum plasma spray system (VPS). By introducing a SiC buffer layer, we successfully integrated C.C composites with a 110-μm-thick protective coating layer of HfC. Compared to the conventional chemical vapor deposition process, the HfC coating process by VPS showed increments in the growth rate, thickness, and hardness. The growth behavior and morphology of HfC coatings were investigated by FE-SEM, EDX, and XRD. In addition, the thermal ablation test results showed that the HfC coating layer perfectly protected the C.C layer from thermal ablation and oxidation. Consequently, we expect that this ultra-high temperature ceramic coating method, and the subsequent microstructure that it creates, can be widely applied to improve the thermal shock and oxidation resistance of materials under ultra-high temperature environments.

Advanced H2O2 oxidation for diethyl phthalate degradation in treated effluents: effect of nitrate on oxidation and a pilot-scale AOP operation

Ko, K. B.,Park, C. G.,Moon, T. H.,Ahn, Y. H.,Lee, J. K.,Ahn, K. H.,Park, J. H.,Yeom, I. T. IWA Publishing 2008 Water Science & Technology Vol.58 No.5

<P>One of the objectives of this study was to delineate the effect of nitrate on diethyl phthalate (DEP) oxidation by conducting a bench-scale ultraviolet (UV)/H2O2 and O3/H2O2 operations as suggested in a previous study. We also aim to investigate DEP oxidation at various UV doses and H2O2 concentrations by performing a pilot-scale advanced oxidation processes (AOP) system, into which a portion of the effluent from a pilot-scale membrane bioreactor (MBR) plant was pumped. In the bench-scale AOP operation, the O3 oxidation alone as well as the UV irradiation without H2O2 addition could be among the desirable alternatives for the efficient removal of DEP dissolved in aqueous solutions at a low DEP concentration range of 85±15 μg/L. The adverse effect in the UV/H2O2 process was significantly greater than that in the UV oxidation alone, and its oxidation was almost halved by the nitrate. However, the nitrate clearly enhanced the DEP oxidation in the O3 oxidation and O3/H2O2 process. Especially, the addition of nitrate almost doubled the DEP oxidation efficiency in the O3/H2O2 process. The series of pilot-scale AOP operations confirmed that about 30-50% of DEP dissolved in the treated MBR effluent streams was, at least, oxidized by the O3 oxidation alone as well as the UV irradiation without H2O2 addition. The UV photolysis of H2O2 was most effective for DEP degradation with an H2O2 concentration of 40 mg/L at a UV dose of 500 mJ/cm2.</P>

Effect of fermentation conditions on biohydrogen production from lipid-rich food material

Kim, H.,Moon, S.,Abug, A.,Choi, S.C.,Zhang, R.,Oh, Y.S. Pergamon Press ; Elsevier Science Ltd 2012 International journal of hydrogen energy Vol.37 No.20

Among the basic components of organic materials, such as carbohydrate, protein, and lipid, the hydrogen yield of carbohydrate fermentation has been reported to be significantly higher than that of lipid. This study used lard as a model organic matter for lipid and investigated its H<SUB>2</SUB> production potential in batch anaerobic fermentation experiments under various combinations of stirring and CO<SUB>2</SUB>-scavenging conditions. A significant increase in the hydrogen yield was observed in both CO<SUB>2</SUB>-scavenging and stirring conditions; the CO<SUB>2</SUB>-scavenging condition yield was 2.9 times higher than the stirring condition (116.7 and 40.3 mL H<SUB>2</SUB>/g volatile solid [VS], respectively), which was much greater than reported previously. A maximal hydrogen yield of 185.8 mL H<SUB>2</SUB>/g VS was obtained in the presence of both CO<SUB>2</SUB>-scavenging and stirring, and the H<SUB>2</SUB> content of the total biogas was as high as 99% (v/v). In addition, there was less H<SUB>2</SUB> and more CH<SUB>4</SUB> production in the absence of CO<SUB>2</SUB>-scavenging and/or stirring, which suggests that the consumption of H<SUB>2</SUB> and CO<SUB>2</SUB> for methanogenesis was the major mechanism of the poor hydrogen yield from lipid. The volatile fatty acids in all the tests consisted primarily of valeric (47.2-54.9%) and propionic acids (26.6-30.3%), and higher concentrations of these acids remained in the fermentation liquid without CO<SUB>2</SUB> removal. These results suggest that lipid-rich food waste is a potential source for H<SUB>2</SUB> production if the fermentation process is optimized to minimize the partial pressure of CO<SUB>2</SUB> and H<SUB>2</SUB> and restrain the activities of H<SUB>2</SUB>-consuming bacteria.

Apoptotic cell death in rat epididymis following epichlorohydrin treatment

Lee, I.-C.,Kim, K.-H.,Kim, S.-H.,Baek, H.-S.,Moon, C.,Yun, W.-K.,Nam, K.-H.,Kim, H.-C.,Kim, J.-C. SAGE Publications 2013 Human & experimental toxicology Vol.32 No.6

<P>Epichlorohydrin (ECH) is an antifertility agent that acts both as an epididymal toxicant and an agent capable of directly affecting sperm motility. This study identified the time course of apoptotic cell death in rat epididymides after ECH treatment. Rats were administrated with a single oral dose of ECH (50 mg/kg). ECH-induced apoptotic changes were evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and its related mechanism was confirmed by Western blot analysis and colorimetric assay. The TUNEL assay showed that the number of apoptotic cells increased at 8 h, reached a maximum level at 12 h, and then decreased progressively. The Western blot analysis demonstrated no significant changes in proapoptotic Bcl-2-associated X (Bax) and anti-apoptotic Bcl-2 expression during the time course of the study. However, phospho-p38 mitogen-activated protein kinase (p-p38 MAPK) and phospho-c-Jun amino-terminal kinase (p-JNK) expression increased at 8–24 h. Caspase-3 and caspase-8 activities also increased at 8–48 h and 12–48 h, respectively, in the same manner as p-p38 MAPK and p-JNK expression. These results indicate that ECH induced apoptotic changes in rat epididymides and that the apoptotic cell death may be related more to the MAPK pathway than to the mitochondrial pathway.</P>

SIGN-R1, a C-type lectin, enhances apoptotic cell clearance through the complement deposition pathway by interacting with C1q in the spleen

MG Prabagar,Y Do,S Ryu,J-Y Park,H-J Choi,W-S Choi,TJ Yun,J Moon,I-S Choi,K Ko,K Ko,C Young Shin,C Cheong,Y-S Kang 한국당과학회 2013 한국당과학회 학술대회 Vol.2013 No.1

Complements, such as C1q and C3, and macrophages in the splenic marginal zone (MZMs) play pivotal roles in the efficient uptake and processing of circulating apoptotic cells. SIGN-R1, a C-type lectin that is highly expressed in a subpopulation of MZMs, regulates the complement fixation pathway by interacting with C1q, to fight blood-borne Streptococcus pneumoniae. Therefore, we examined whether the SIGN-R1-mediated classical complement pathway plays a role in apoptotic cell clearance and immune tolerance. SIGN-R1 first-bound apoptotic cells and this binding was significantly enhanced in the presence of C1q. SIGN-R1-C1q complex then immediately mediated C3 deposition on circulating apoptotic cells in the MZ, leading to the efficient clearance of them. SIGN-R1-mediated C3 deposition was completely abolished in the spleen of SIGN-R1 knockout (KO) mice. Given that SIGN-R1 is not expressed in the liver, we were struck by the finding that C3-deposited apoptotic cells were still found in the liver of wild-type mice, and dramatically reduced in the SIGN-R1 KO liver. In particular, SIGN-R1 deficiency caused delayed clearance of apoptotic cells and aberrant secretion of cytokines, such as TNF-α, IL-6, and TGF-β in the spleen as well as in the liver. In addition, anti-double- and single-stranded DNA antibody level was significantly increased in SIGN-R1-depleted mice compared with control mice. These findings suggest a novel mechanism of apoptotic cell clearance which is initiated by SIGN-R1 in the MZ and identify an integrated role of SIGN-R1 in the systemic clearance of apoptotic cells, linking the recognition of apoptotic cells, the opsonization of complements, and the induction of immune tolerance.