MC-50 싸이클로트론을 이용한 Mn-54 제법 연구

유국현,서용섭 東國大學校 2000 東國論叢 Vol.39 No.-

The half-life of ^54Mn is 312.2 days and main γ-energy is 835keV, therefore it is used as a standard source for a multi-channel analyzer and a dose calibrator and managanese catabolism study in human body. In this paper, a method for the production of no carrier added ^54Mn was studied via ^54Cr(p,n) and ^59Co(p, αpn), with MC-50 cyclotron and described chemical isolation method of ^54Mn from a irradiated target by ion exchange resin. Chromium and cobalt were used as target materials. The production yields of ^54Mn by 50.5 MeV protons was 4.5 μCi.μ/Ah on chromium target and 11.85 μCi/μAh on cobalt target. The cross-section and thick target yield of ^59Co(p, αpn)^54Mn reaction were measured in the energy range of 50.5→22.2MeV in order to determine the optimum conditions for the production of ^54Mn. the maximum cross-section was 47.48 mbarn at 41.2MeV.

^27Al(p,α pn)핵반응에 의한 무담체 ^22Na 제법 연구

유국현,서용섭,양승대 東國大學校 1998 東國論叢 Vol.37 No.-

A method for the production of no-carrier added(NCA) ^22Na was developed via ^27Al(p, ㄷαpn) nuclear reaction with 50.5MeV protons. the half life of ^22Na is 2.6 years and main γ-energy is 1274.5keV and it is used standard source and sodium catabolism study. The cross-section and thick target yield for the reaction was measured in detail in the energy range of 50.5→20.2MeV in order to determine the optimum conditions for the production of ^22Na. the maximum cross-section for the production of ^22Na was 40.8 mbarn at 43.85MeV. the calculated production yield of ^22Na by 50.5MeV protons on aluminium was 60.9μCi/μAh. The seperation of ^22Na was carried out by ion exchange, precipitation and diffusion. It was found that ion exchange column operation using AG50W-X4 resin was the most efficient method among them.

Photophysical Properties of Thermally Activated Delayed Fluorescent Materials upon Distortion of Central Axis of Donor Moiety

Kim, Hyung Suk,Park, Hansol,Park, So-Ra,Lee, Sang Hoon,Ahn, Yunho,Lee, Yong Sup,Suh, Min Chul American Chemical Society 2018 JOURNAL OF PHYSICAL CHEMISTRY C - Vol.122 No.50

<P>In this study, we showed the distortion of the central axis of the donor moiety can switch critically the rate of the reverse intersystem crossing (<I>k</I><SUB>RISC</SUB>) process, which is the trigger point to modulate the lifetime of delayed fluorescence. To achieve <I>k</I><SUB>RISC</SUB>, what we desired (10<SUP>5</SUP> to 10<SUP>6</SUP> s<SUP>-1</SUP>) in a series of donor-acceptor-donor (D-A-D) type thermally activated delayed fluorescence (TADF) materials, the donor groups (phenoxazine and phenothiazine) were selectively introduced. Maintaining the near orthogonality between donor and acceptor (benzonitrile) moiety, the occurrence of the distortion of the central axis of the donor moiety could make the effect of locally excited triplet state (<SUP>3</SUP>LE). In other words, the interaction between <SUP>3</SUP>LE and the charge transfer counterparts (i.e., <SUP>1</SUP>CT and <SUP>3</SUP>CT) contributes an opposite propensity of <I>k</I><SUB>RISC</SUB> for each of the target TADF materials when those are dissolved in solution and condensed in solid state. Herein, we have theoretically and experimentally shown the photophysical behavior of common D-A-D type TADF upon the different systems.</P> [FIG OMISSION]</BR>

An Environmentally-friendly Precursor, Ferrous Acetate, in preparation for Monodisperse Iron Oxide Nanoparticles

Yong Jae Suh,Dae Sup Kil,Kang Sup Chung,Hyo Sook Lee,Huiping Shao 한국자기학회 2008 Journal of Magnetics Vol.13 No.3

Almost monodisperse iron oxide nanoparticles with an average particle size ranging from 5 to 43 ㎚ were fabricated using an enviro㎚entally friendly starting material, ferrous acetate. The smallest particles were formed in the presence of a reductant, 1,2-dodecanediol, while the particle size increased with increasing concentration of dispersing agents. The dispersants consisted of various combinations of oleic acid, oleylamine, trioctylphosphine, and polyvinylpyrrolidone. The threshold temperature to form crystalline particles was found to be 240 ℃. The 43 ㎚ nanoparticles exhibited a room temperature saturation magnetization and coercivity of 57 emu/g and 47 Oe, respectively.

기술정보 : 장래 기능성화장품 원료로서의 할로이사이트 활용에 관한 연구동향

서용재 ( Yong Jae Suh ),장영남 ( Young Nam Jang ),길대섭 ( Dae Sup Kil ),정강섭 ( Kang Sup Chung ),이수정 ( Su Jeong Lee ) 한국광물학회 2008 광물과 암석 (J.Miner.Soc.Korea) Vol.21 No.4

나노튜브 형상의 할로이사이트는 화장품·약물 등 활성물질의 방출시간을 연장하는데 응용할 수 있는 천연 나노광물이다. 할로이사이트를 이용한 활성물질 적재·방출 제어기술을 최초로 등록한 1997년 미국 특허를 필두로 2007년에는 비타민과 글리세린 등의 기능효과제를 광범위하게 포함하는 기능성화장품 제조기술에 대한 특허가 출원되었다. 학술 논문으로서는 화장품 보다 서방형 약물전달 기술에 관한 연구가 주로 발표되고 있다. 최근 화장품용 분체에 단순한 기재로서의 역할 뿐만 아니라 기능성을 추가로 부여하고 있다. 특히, 할로이사이트는 기능성 화장성분의 전달 속도를 제어할 수 있으며 다른 분체보다 밀도가 낮아 팩·크림·로션류의 기재로 적합하다. 따라서 나노튜브형 할로이사이트를 활용한 나노캐리어 기술은 최근 화장품 유형별 시장점유율에서 2위로 부상한 기능성화장품 분야의 핵심기술로 성장할 것으로 기대된다.

Identification of antigenic proteins from Neospora caninum recognized by bovine immunoglobulins M, E, A and G using immunoproteomics

Shin, Yong-seung,Lee, Eung-goo,Shin, Gee-wook,Kim, Young-rim,Lee, Eun-young,Kim, Jae-hoon,Jang, Hwan,Gershwin, Laurel J.,Kim, Dae-yong,Kim, Yong-hwan,Kim, Gon-sup,Suh, Myung-deuk,Jung, Tae-sung WILEY-VCH Verlag 2004 Proteomics Vol.4 No.11

<P>Antigenic proteins of Neospora caninum (N. caninum) against bovine immunoglobulins M, E, A, and G were investigated by using immunoproteomics. Proteins of N. caninum (KBA-2) tachyzoite lysates separated by two-dimensional gel electrophoresis were transferred to polyvinylidene difluoride (PVDF) membranes, probed with different bovine immunoglobulin class and classified. Antigenic spots recognized were also identified by matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) analysis. 132, 84, 4, and 40 antigenic protein spots were recognized on N. caninum immunoblot profiles against bovine IgM, IgE, IgA, and IgG, respectively. Of these protein spots, the antigenic proteins recognized by either IgM, IgE, and IgG, or IgM and IgG were HSP70, pyruvate kinase, actin, NCDG-1, tubulin α-chain, and putative ribosomal protein S2. On the other hand, IgM, IgE, and IgA reacted with NTPase, HSP60, tubulin β-chain, putative protein disulfide isomerase, enolase, lactate dehydrogenase, serine-threonine phosphatase, 14-3-3 protein homologue, and GRA2 protein. Most of the antigenic proteins identified were associated with the process of invasion, proliferation, and egression of apicomplexans. In our study, HSP70, actin, NTPase, HSP60, pyruvate kinase, enolase, putative ribosomal protein S2, NCDG-1, and GRA2 proteins were found to be immunodominant proteins, which may contribute to the development of diagnostic markers and vaccine.</P>

A Review on the Application of Nanotechnology in Food Processing and Packaging

Seong-In Cho,Yong-Rok Kim,Joon Woo Lee,Dae-Sup So,Yong-Jin Cho,Hyun Kwon Suh,Tu San Park,Seoung-Im Oh,Ji-Eun Im 한국산업식품공학회 2010 산업 식품공학 Vol.14 No.4

Currently, nanotechnology is widely applied in various industrial fields and is rapidly emerging as a promising future technology. In food industries, nanotechnology is used to enhance food quality and safety. Numerous cutting-edge studies on the advantages of nanotechnology have been conducted in the fields of food processing, food ingredients and additives, food packaging, and food engineering for optimal health. The market for these areas of research has grown steadily, and is expected to continue to do so. Because of this, R&D for nanotechnology that can be used effectively in food industries is being performed by several companies, as well as in academic research institutions around the world. This review describes the recent global R&D trends that have been in progress for two key areas: food processing and food packaging.

Cost-Benefit Analysis of Tafenoquine for Radical Cure of Plasmodium vivax Malaria in Korea

Suh Jiyeon,Kim Jung Ho,Kim Jong-Dae,Kim Changsoo,Choi Jun Yong,Lee Jeehyun,Yeom Joon-Sup 대한의학회 2022 Journal of Korean medical science Vol.37 No.27

Background: Plasmodium vivax malaria has a persistent liver stage that causes relapse, and introducing tafenoquine to suppress relapse could aid in disease eradication. Therefore, we assessed the impact of tafenoquine introduction on P. vivax malaria incidence and performed a cost-benefit analysis from the payer’s perspective. Methods: We expanded the previously developed P. vivax malaria dynamic transmission model and calibrated it to weekly civilian malaria incidences in 2014–2018. Primaquine and tafenoquine scenarios were considered by assuming different relapse probabilities, and relapse and total P. vivax malaria cases were predicted over the next decade for each scenario. We then estimated the number of cases prevented by replacing primaquine with tafenoquine. The cost and benefit of introducing tafenoquine were obtained using medical expenditure from a nationwide database, and a cost-benefit analysis was conducted. A probabilistic sensitivity analysis was performed to assess the economic feasibility robustness of tafenoquine introduction under uncertainties of model parameters, costs, and benefits. Results: Under 0.04 primaquine relapse probability, the introduction of tafenoquine with relapse probability of 0.01 prevented 129 (12.27%) and 35 (77.78%) total and relapse cases, respectively, over the next decade. However, under the same relapse probability as primaquine, introducing tafenoquine had no additional preventative effect. The 14- day primaquine treatment cost was $3.71. The tafenoquine and the glucose-6-phosphate dehydrogenase rapid diagnostic testing cost $57.37 and $7.76, totaling $65.13. The average medical expenditure per malaria patient was estimated at $1444.79. The cost-benefit analysis results provided an incremental benefit-cost ratio (IBCR) from 0 to 3.21 as the tafenoquine relapse probability decreased from 0.04 to 0.01. The probabilistic sensitivity analysis showed an IBCR > 1, indicating that tafenoquine is beneficial, with a probability of 69.1%. Conclusion: Tafenoquine could reduce P. vivax malaria incidence and medical costs and bring greater benefits than primaquine.

Synthesis of 1, 4-dihydropyridine derivatives with vasodilating activities (l)

Suh, Jung-Jin,Lee, Bong-Yong,Kim, Chang-Seop,Lee, Jong-Wook,Kim, Byung-Chae,Han, Byung-Hee,Kim, Choong-Sup The Pharmaceutical Society of Korea 1990 Archives of Pharmacal Research Vol.13 No.3

Asymmetric 2, 6-dimethyl-4-aryl-1, 4-dihydropyridine-3, 5-dicarboxylate with [N-(3, 4-methylenedioxybenzyl)-N-methyl] aminoethyl group as the ester moiety and related 1, 4-dihydropyridine derivatives were prepared and tested for the effects on vascular smooth muscles. 2-6-dimethyl-4-(3'-nitrophenyl)1-4-dihydropyridine-3, 5-dicarboxylic acid 3-[N-(3', 4-methylenedioxybenzyl-N-methyl] aminoethyl ester 5-methyl ester (11) and 2, 6-dimethyl-4-(3'-nitrophenyl)-1, 4-dihydropyridine-3, 5-icarboxylic acid 3-[N-2', 3'-methylenedioxybenzyl)-N-methyl] aminoethyl ester 5-ethyl ester (150 showed potent vasodilating activities $IC_{50}$($10_{-8}M$) was 2, 6 and 2.7 for 11 and 15, compared with 3.5 for nicardipine.

Production of High-purity Magnetite Nanoparticles from a Low-grade Iron Ore via Solvent Extraction

( Yong Jae Suh ),( Thi May Do ),( Dae Sup Kil ),( Hee Dong Jang ),( Kuk Cho ) 한국화학공학회 2015 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.53 No.1

We produced magnetite nanoparticles (MNPs) and a Mg-rich solution as a nano-adsorbent and a coagulant for water treatment, respectively, using a low-grade iron ore. The ore was leached with aqueous hydrochloric acid and its impurities were removed by solvent extraction of the leachate using tri-n-butyl phosphate as an extractant. The content of Si and Mg, which inhibit the formation of MNPs, was reduced from 10.3 wt% and 15.5 wt% to 28.1 mg/L and < 1.4 mg/L, respectively. Consequently, the Fe content increased from 68.6 wt% to 99.8 wt%. The high-purity Fe3+ solution recovered was used to prepare 5-15-nm MNPs by coprecipitation. The wastewater produced contained a large amount of Mg2+ and can be used to precipitate struvite in sewage treatment. This process helps reduce the cost of both sewage and iron-orewastewater treatments, as well as in the economic production of the nano-adsorbent.