http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Interface Shear Strength at Joints of Ultra‑High Performance Concrete Structures
Young?Jin Kim,Won?Jong Chin,Se?Jin Jeon 한국콘크리트학회 2018 International Journal of Concrete Structures and M Vol.12 No.6
When ultra-high performance concrete (UHPC) is fabricated as precast members such as in a UHPC segmental bridge, the joint design between the precast members can significantly affect the overall integrity and safety of the structure. Therefore, the structural behavior of the UHPC joint was experimentally investigated in this study with test variables including joint type, number and height of shear keys, type of filler, curing temperature, and lateral compressive stress. The UHPC considered in this study is the K-UHPC developed in Korea with a specified compressive strength as high as 180 MPa and high flowability. The joint shear strengths affected by the test variables were investigated in detail. The test results were also compared with two representative predictive equations for interface shear strength to determine an appropriate equation for the joint design of UHPC. These equations did not match well with the test data because they were originally proposed for normal strength concrete. However, the JSCE equation could be improved by modifying a coefficient to show good agreement with the test especially in the case of the dry joint with epoxy application.
Microbiological Contamination of Laboratory Mice and Rats in Korea from 2007 to 2008
Young-Suk Won,Hyo-Jung Kwon,Sang-Woon Kim,Jong-Tak Han,Sae-Bhom Lee,Ki-Hoan Nam,Won-Kee Yoon,Kang-Hyun Kim,Oc-Sung Moon,Hyoung-Chin Kim 한국실험동물학회 2010 Laboratory Animal Research Vol.26 No.3
In order to assess the microbiological contamination of laboratory mice and rats in Korea over the 2-year period from 2007 to 2008, we monitored animals housed in mouse and rat facilities equipped with barrier systems. In a barrier animal facility in Korea, the most important viruses in the identified pathogen were the mouse hepatitis virus (MHV) and Pasteurella (Pa.) pneumotropica, and Staphylococcus aureus was identified as the most common bacterial pathogen in Korea. The most commonly detected parasite in the identified pathogen was Trichomonas spp. in the mouse facilities and Entamoeba spp. in the rat facilities. In many cases, these pathogen-contaminated animals were genetically modified animals obtained from the university. Currently, consistent with the increased transfer of genetically modified animals between domestic and foreign animal facilities, the Pa. pneumotropica and parasites infection rates were shown to have increased as compared to those of the 2004-2006 period. Indeed, the MHV infection rate has been maintained at almost 20% in Korean animal facilities over the past 10 years. These results showed that effective quarantine programs for contaminated genetically engineered mutant mice and the monitoring of regular or irregular MHV monitoring in animal colonies should help to reduce pathogen contamination in Korean animal facilities.
Two Step Carcinogen Screening Model Using Neonatal FVB/NJ Mouse
Young-Suk Won,Hyo-Jung Kwon,Yang-Kyu Choi,Hyun-Ji Park,Eui-Suk Jeong,Bon-Chul Koo,Oc-Sung Moon,Ki-Hoan Nam,Hyoung-Chin Kim 한국실험동물학회 2007 Laboratory Animal Research Vol.23 No.3
A long-term carcinogenicity study is required to assess the safety of new drug candidates. This classical toxicological method has been using rats and mice as animal systems. The International Conference on Harmonization (ICH) of technical requirements of pharmaceuticals for human use have recommended one long-term rodent carcinogenicity test using rat and one other supplementary mouse study such as an initiation-promotion model, a transgenic model or a neonatal model. This study was carried out to develop an initiation-promotion liver carcinogenicity model using a mouse. Twelve-day old FVB/NJ mice were intraperitoneally injected with diethyl nitrosamine (DEN) as an initiator and orally administered with 2-acetlyaminofluorene (2-AAF) as a promoter. And o-galactosamine (DGA) was injected as a stimulator for tumorigenic progress. Basophilic foci in the liver were observed 16 weeks after initiation. The incidence of hepatocellular adenoma was increased in animals 2-AAF-treated at 20 and 26 weeks after initiation. The tumor incidence in 2-AAF-treated animals were significantly higher than with the untreatment and initiator treatment control groups. Hepatocellular carcinoma (HCC) was found in some cases. These results suggest that two-step neonatal FVB/NJ mouse model could be useful for carcinogenic assay of new drug candidates.
Microbiological Contamination of Laboratory Mice and Rats in Korea from 1999 to 2003
WON, Young-Suk,JEONG, Eui-Suk,PARK, Hyun-Ji,LEE, Chul-Ho,NAM, Ki-Hoan,KIM, Hyoung-Chin,HYUN, Byung-Hwa,LEE, Sang-Koo,CHOI, Yang-Kyu KINOKUNIYA CO LTD 2006 EXPERIMENTAL ANIMALS Vol.55 No.1
<P>To survey the microbiological contamination of laboratory mice and rats in Korea during a 5-year period, we monitored animals housed in mouse and rat facilities with either barrier or conventional systems. At barrier and conventional mouse facilities, the most important pathogen identified was mouse hepatitis virus (MHV), while <I>Mycoplasma pulmonis</I> was the most important pathogen at conventional rat facilities. Interestingly, hantavirus was recovered from both barrier and conventional mouse facilities. The most common protozoon identified was <I>Tritrichomonas muris</I> in mouse facilities and <I>Entamoeba muris</I> in rat facilities. In addition, we found that the microbiological contamination of mice and rats in conventional facilities was severe. These results suggest that conventional facilities should be renovated and monitored regularly to decrease microbiological contamination. We also propose that hantavirus should be monitored in Korea as an important mouse pathogen.</P>
Won, Hee‐,Young,Lee, Jeong‐,Yeon,Shin, Dong‐,Hui,Park, Ji‐,Hye,Nam, Jeong‐,Seok,Kim, Hyoung‐,Chin,Kong, Gu Federation of American Society for Experimental Bi 2012 The FASEB Journal Vol.26 No.12
<P>Mel-18 has been proposed as a negative regulator of Bmi-1, a cancer stem cell (CSC) marker, but it is still unclear whether Mel-18 is involved in CSC regulation. Here, we examined the effect of Mel-18 on the stemness of human breast CSCs. In Mel-18 small hairpin RNA (shRNA)-transduced MCF-7 cells, side population (SP) cells and breast CSC surface marker (CD44(+)/CD24(-)/ESA(+))-expressing cells, which imply a CSC population, were enriched. Moreover, the self-renewal of CSCs was enhanced by Mel-18 knockdown, as measured by the ability for tumorsphere formation in vitro and tumor-initiating capacity in vivo. Similarly, Mel-18 overexpression inhibited the number and self-renewal activity of breast CSCs in SK-BR-3 cells. Furthermore, our data showed that Mel-18 blockade up-regulated the expression of the Wnt/TCF target Jagged-1, a Notch ligand, and consequently activated the Notch pathway. Pharmacologic inhibition of the Notch and Wnt pathways abrogated Mel-18 knockdown-mediated tumorsphere formation ability. Taken together, our findings suggest that Mel-18 is a novel negative regulator of breast CSCs that inhibits the stem cell population and in vitro and in vivo self-renewal through the inactivation of Wnt-mediated Notch signaling.</P>