http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Kyoung Suk Choi,Chul-Joo Lim,Soon Young Ahn,Tek Seung Kim,Jiseon Kim,Byoung-Guk Kim,한경호,Sang Ja Ban,Hyung Soo Kim,Youngju Choi 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.4
Recently, the genetic modification of mesenchymal stem cells (MSCs) has led to increased differentiation potential. For the therapeutic application of genetically modified MSCs, it is crucial to evaluate their characteristics and safety. In this study, we investigated the effects of bone morphogenetic protein 2 (BMP2) gene transfer on the characteristics and biodistribution of human MSCs. Lentiviral-mediated BMP2 transduction to MSCs enhanced osteocyte differentiation and decreased adipocyte differentiation. Although there is no significant difference in cell proliferation capacity, MSCs transduced BMP2 proliferate somewhat higher than nontransduced or GFP transduced MSCs. No significant changes were observed in surface antigen expression in genetically modified MSCs. In vivo transplantation of lentiviral-mediated BMP2 gene transferred MSCs to nude mice did not result in tumor formation. To evaluate the biodistribution of genetically modified cells, MSCs carrying BMP2 were injected into the tail vein of femur fractured mice. The introduced MSCs were detected in the spleen, testis and fractured femur 28 days post-implantation. These findings suggest that diverse safety tests for genetically modified MSCs should be considered, particularly when a lentivirus mediated gene transfer method is used.
Measurements of Cerenkov Lights Using Optical Fibers
Bongsoo Lee,Kyoung Won Jang,Wook Jae Yoo,Sang Hun Shin,Jinsoo Moon,Ki-Tek Han,Dayeong Jeon IEEE 2013 IEEE transactions on nuclear science Vol.60 No.2
<P>Optical fibers can be a medium to produce Cerenkov light due to their dielectric components, and radiation-induced light signals can be obtained using optical fibers without any scintillating material. In this study, we measured and characterized gamma-ray induced Cerenkov light in silica optical fibers, a plastic optical fiber, and a plastic wavelength shifting fiber in order to select the adequate optical fiber for producing Cerenkov light. Also, we measured the intensity of Cerenkov light as functions of irradiated length, irradiation angle, and thickness of various scatterers using the chosen optical fiber.</P>
Synthesis of Titanium Carbide by Thermo-Chemical Methods with TiH2 and Carbon Black Powders
( In Shup Ahn ),( Tek Kyoung Sung ),( Sung Yeal Bae ),( Ho Jung Cho ),( Dong Kyu Park ) 대한금속재료학회 ( 구 대한금속학회 ) 2006 METALS AND MATERIALS International Vol.12 No.3
A new synthesizing method for producing submicron TiC powders was studied by using TiH2 and carbon black powders. It is well known that hydrogen absorption transforms titanium from metal (h.c.p.) to brittle hydride (f.c.c.) powders by ball-milling. This research focused on obtaining submicron-sized TiC powders from the ball-milled mixture of TiH2 and carbon black by thermal treatment. The hydrogen, carbon, iron, and oxygen composition changes in the mixed powders were analyzed. Thereafter, a differential thermal analysis (DTA) test was performed to observe change of phase with ball-milling time. The TiC powders were obtained by heat treating the powders milled for 5 h at various temperatures (600-1200℃). The phase microstructure was investigated via DTA, X-ray diffraction (XRD), and scanning electron microscope (SEM). The mixture milled for 2 h had an f.c.t. structure containing 66.73 at.%H transformed to f.c.c. by milling for 4 h. After 5h of ball-milling, submicron-sized particles of 273 nm were obtained. At the isothermal heat-treating temperature of 500℃, the Ti single phase was formed completely, and the TiC phase of lattice parameter 0.310 nm was completely formed over the temperature of 1000℃.
Titanium hydride를 이용한 TiC분말의 제조 및 특성
성택경,안인섭,배승열,정우현,박동규,정광철,김유영,Sung Tek Kyoung,Ahn In-Shup,Bae Sung-Yeal,Jeong Woo Hyun,Park Dong-Kyu,Jung Kwang Chul,Kim You-Young 한국분말야금학회 2005 한국분말재료학회지 (KPMI) Vol.12 No.3
This paper deals with the fabrication of titanium carbide using fine titanium hydride. The ratio of $TiH_2$ and C (Activated carbon) was 1:1 (mol) and milled in a planetary ball mill at a ball-to-powder weight ratio of 20:1. Thereafter, TGA was performed at $1400^{\circ}C$ to observe change of weight with milling time. Titanium carbide was obtained by using tempering the milled powders at $1100-1500^{\circ}C$. The microstructures of titanium carbide as well as the change of the lattice parameters and particle size have been studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM).
A study on the Active Material FeS<sub>2</sub> in Battery Fabricated by Mechanical Alloying
Jung Woo-Hyun,Ahn In-Shup,Ahn Hyo-Jun,Bae Sung-Yeal,Sung Tek-Kyoung,Kim Tae-Bum,Kim You-Young The Korean Powder Metallurgy Institute 2005 한국분말재료학회지 (KPMI) Vol.12 No.3
As the electrodes of secondary battery are made with sulfur compounds, excellent electrode system of environmental non-toxicity, high specific energy density and low material cost can be obtained. In this study, the $FeS_2$ fine compound powders for active material in the battery were synthesized by mechanical alloying. Fine Fe-53.5 wt.%S powders of 450 nm of mean size were fabricated by mechanical alloying for 60 hours at the horizontal attritor. As the mechanical alloying time increases, particle size of Fe-53.5 wt.%S was decreased and steady state of Fe-53.5 wt.%S compound powders was obtained at 30 hours. Fe-53.5 wt.%S cathode shows the excellent discharge capacity (1011 mAh/g).
ZnS 형광체 분말제조를 위한 기계적합금화법의 응용 연구
안인섭,정우현,배승열,성택경,박동규,Ahn In-Shup,Chong Woo-Hyun,Bae Sung-Yeal,Sung Tek-Kyoung,Park Dong-Kyu 한국분말야금학회 2005 한국분말재료학회지 (KPMI) Vol.12 No.4
In this study, the ZnS composite powders for host material in phosphor was synthesized in situ by mechanical alloying. As the mechanical alloying time increases, particle size of ZnS decreases. ZnS powders of $1.85\;\mu{m}$ in a mean size was fabricated by mechanical alloying for 10h. The crystal structures of ZnS powders were investigated by X-ray diffraction and the photo-luminescence properties was evaluated with the optical spectra analyzer. The steady state condition of mechanically alloyed ZnS was obtained as a mean particle size of $2\;\mu{m}$ in 5h milling. The sphalerite and wurtize structures coexist in the ZnS mechanically alloyed for 5h. The ZnS powder mechanically alloyed for 10h grows to the sphalerite structure. And the strong emission peaks of ZnS are observed at 480 nm wave length at the powders of mechanically alloyed for 10h, but the sphalerite and wurtize structures in ZnS coexist and emission peaks are not appeared at the powders of mechanically alloyed for 10h.