http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
맞대기 용접 이음재 인장시험에서 발생한 음향방출 신호의 웨이블릿 변환과 응용
이장규,윤종희,우창기,박성완,김봉각,조대희 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-
This study was carried out fusion-welded butt joints in SWS 490A high strength steel subjected to tensile test that load-deflection curve. The windowed or short-time Fourier transform (WFT or SIFT) makes possible for the analysis of non-stationary or transient signals into a joint time-frequency domain and the wavelet transform (WT) is used to decompose the acoustic emission (AE) signal into various discrete series of sequences over different frequency bands. In this paper, for acoustic emission signal analysis to use a continuous wavelet transform, in which the Gabor wavelet base on a Gaussian window function is applied to the time-frequency domain. A wavelet transform is demonstrated and the plots are very powerful in the recognition of the acoustic emission features. As a result, the technique of acoustic emission is ideally suited to study variables which control time and stress dependent fracture or damage process in metallic materials.
음향방출 신호를 이용한 SWS 490A 고장력강의 접합성 평가에 대한 실험적 연구
이장규,우창기,윤종희,조진호,조대희,박성완,김봉각,구영덕 한국공작기계학회 2004 한국공작기계학회 추계학술대회논문집 Vol.2004 No.-
The object of this study is to investigate the effect of joinability by using acoustic emission (AE) signals and doing a pattern recognition for weld heat affected zone (HAZ) in tensile testing. This study was carried out an SWS 490A high tension steel for electric shielded metal arc welding (SMAW), CO₂ gas arc welding and TIG welding. And correspondingly, the root openings are 3, 4 and 2.8㎜. The results of the tensile test of weld HAZ come out electric shield arc welding > CO₂ gas arc welding > TIG welding in case of single welding. It is believed that this is a phenomenon where difference of its root opening or base metal thickness. Also, the technique of AE is ideally suited to study variables which control time and stress dependent fracture or damage process in metallic materials.
Dae Ki Joung,Dong Young Shin,Dong Yeul Kwon,Dong Won Shin 한국자원식물학회 2016 한국자원식물학회지 Vol.29 No.6
Methicillin-resistant Staphylococcus aureus (MRSA) is a serious clinical and an urgent problem worldwide. Few new drugs are available against MRSA, because MRSA has the ability to acquire resistance to most antibiotics, which consequently increases the cost of medication. In the present study, the antibacterial activity of Hydnocarpi Semen was investigated. The most effective method is to develop antibiotics from the natural products without having any toxic or side effects. Therefore, there is a need to develop alternative antibacterial drugs for the treatment of infectious diseases. Five Clinical isolates (MRSA) were obtained from five different patients at Wonkwang University Hospital (Iksan, South Korea). The Other 2 strains were ATCC 33591 (Methicillin-resistant strain) and ATCC 25923 (Methicillin-susceptible strain). Antibacterial activity (Minimal Inhibitory Concentrations, MICs) was determined by broth dilution method, disk diffusion method, MTT test, and checkerboard dilution test. Antibacterial activity of n-hexane fraction was remarkable, and had a MICs ranging from 31.25-125 ㎍/㎖. FICI values for HFH+AM and HFH+OX were 0.13-0.19 and 0.04-0.29, showing the increase of synergistic effect. When combined together, these antibacterial effects were dramatically increased.
JOUNG, DAE-KI,CHOI, SUNG-HOON,KANG, OK-HWA,KIM, SUNG-BAE,MUN, SU-HYUN,SEO, YUN-SOO,KANG, DA-HYE,GONG, RYONG,SHIN, DONG-WON,KIM, YOUN-CHUL,KWON, DONG-YEUL SPANDIDOS PUBLICATIONS 2015 MOLECULAR MEDICINE REPORTS Vol.12 No.1
<P>Methicillin-resistant Staphylococcus aureus (MRSA) infection is a serious clinical problem worldwide. The aim of the present study was to examine the antimicrobial activity of oxyresveratrol (ORV) against MRSA. The antimicrobial activity of ORV was evaluated against three strains of MRSA and one methicillin-susceptible S. aureus (MSSA) strain using a minimal inhibitory concentration (MIC) assay, MTT colorimetric assay, checkerboard dilution test and time-kill assay. The MIC of ORV for all strains was moderate at 125 ?g/ml. Of note, the antimicrobial activity and fractional inhibitory concentration index values of ORV were markedly increased in the presence of a non-growth inhibitory dose of certain antibiotics. Time-kill curves revealed that a combination of ORV with ciprofloxacin or with gentamicin reduced bacterial counts to below the lowest detectable limit after 24 h. These effective combinations may be used as potential antimicrobial regimens for use in the management of MRSA.</P>
Joung, Dae-Ki,Mun, Su-Hyun,Lee, Kuang-Shim,Kang, Ok-Hwa,Choi, Jang-Gi,Kim, Sung-Bae,Gong, Ryong,Chong, Myong-Soo,Kim, Youn-Chul,Lee, Dong-Sung,Shin, Dong-Won,Kwon, Dong-Yeul Hindawi Publishing Corporation 2014 Evidence-based Complementary and Alternative Medic Vol.2014 No.-
<P>Tectorigenin (TTR) is an O-methylated isoflavone derived from the rhizome of <I>Belamacanda chinensis</I> (L.) DC. It is known to perform a wide spectrum of biological activities such as antioxidant, anti-inflammatory, anti-tumor. The aim of this study is to examine the mechanism of antibacterial activity of TTR against methicillin-resistant <I>Staphylococcus aureus</I> (MRSA). The anti-MRSA activity of TTR was analyzed in combination assays with detergent, ATPase inhibitors, and peptidoglycan (PGN) derived from <I>S. aureus</I>. Transmission electron microscopy (TEM) was used to monitor survival characteristics and changes in <I>S. aureus</I> morphology. The MIC values of TTR against all the tested strains were 125 <I><I>μ</I></I>g/mL. The OD(600) of each suspension treated with a combination of Triton X-100, DCCD, and NaN<SUB>3</SUB> with TTR (1/10 × MIC) had been reduced from 68% to 80%, compared to the TTR alone. At a concentration of 125 <I><I>μ</I></I>g/mL, PGN blocked antibacterial activity of TTR. This study indicates that anti-MRSA action of TTR is closely related to cytoplasmic membrane permeability and ABC transporter, and PGN at 125 <I><I>μ</I></I>g/mL directly bind to and inhibit TTR at 62.5 <I><I>μ</I></I>g/mL. These results can be important indication in study on antimicrobial activity mechanism against multidrug resistant strains.</P>
Joung, Ki E.,Min, Kyung N.,An, Jin Y.,kim, Dae-Kee,Kong, Gu,Sheen, Y. Yhong 이화여자대학교 약학연구소 2008 藥學硏究論文集 Vol.- No.17
A novel synthetic inhibitor of histone deacetylase (HDAC), 3-(4-dimethylaminophenyl)-N-hydroxy-2-propenamide (IN- 2001), was examined for its antitumor activity and for the underlying molecular mechanisms of any such activity. IN- 2001 effectively inhibited cellular HDAC activity (IC_(50), 5.42 nmol/L) in MCF-7 human breast cancer cells. Based on the Western blot analysis, this HDAC inhibitory effect of IN-2001 was confirmed by an increase in histone H4 acetylation from the IN-2001-treated breast cancer cells. IN-2001 suppressed mammary tumor growth in MMTV/c-Neu transgenic mice and also showed higher apoptotic index and lower lymphatic invasion compared with controls, In human breast cancer cells (MCF-7, T47D, MDA-MB-231, and MDA-MB-468), IN-2001 induced cell cycle arrest at G_(2)-M phase through up-regulation of p21^(WAF1) and p27^(KIP1) and eventually caused apoptosis. IN- 2001-induced apoptosis was caspase dependent and seems mediated through an increase in Bax/Bcl-2 ratio. Taken together, our data indicate that this novel HDAC inhibitor is a promising therapeutic agent against human breast cancer.