http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Gwon, Hui-Dong,Bang, Jun-Suk,Yoon, Kye-Seok,Park, Se-Hong,Park, Sang-Hui,Jung, Min-Yong,Lee, Sang-Han,Kim, Min-Woo,Hong, Sung-Wan,Cho, Gyu-Hyeong Institute of Electrical and Electronics Engineers 2018 IEEE transactions on power electronics Vol.33 No.4
<P>This letter presents a 2-phase 3-level (2P3L) envelope tracking supply modulator (ETSM) for a long-term evolution 20 MHz (LTE20) radio frequency power amplifier as a solution for the ET system. This 2P3L ETSM that is composed of only switching converters achieves high efficiency, fast transient response, and a small output current ripple. To properly operate the proposed 2P3L ETSM, 4 pulse width modulatiop (PWM) signals with a 90° phase shift from each PWM signal are required without any mismatch between duty cycles. To remove the mismatch, a time-division multiplexing comparator and a duty-cycle calibrator are proposed. Thanks to the proposed techniques, the proposed ETSM fabricated in 0.18-μm CMOS achieved the highest peak dynamic efficiency of 88.6% with an LTE20 signal, which is superior to the state-of-the-art systems.</P>
방사선을 이용한 느릅나무 추출 다당류가 함유된 하이드로젤의 제조 및 항염증성 평가
권희정(Hui Jeong Gwon),박은지(Eun Ji Park),최종배(Jong Bae Choi),임종영(Jong Young Lim),정진오(Jin Oh Jeong),신영민(Young Min Shin),정성린(Sung In Jeong),박종석(Jong Seok Park),임윤묵(Youn Mook Lim),최영훈(Young Hun Choi),김상숙(Sang 한국고분자학회 2014 폴리머 Vol.38 No.1
본 연구에서는 방사선 기술을 이용하여 항염증 특성을 가지는 천연 추출물을 함유하는 고분자 하이드로젤을 제조하여 항염증 패치로서의 유용성을 확인하였다. 천연 추출물로는 오래 전부터 전통 민간요법으로 항염제나 궤양 및 종양 치료 등에 사용되고 있는 느릅나무를 사용하였고, 생체 적합성 고분자인 poly(vinyl alcohol)(PVA)와 보습률 향상을 위해 글리세린을 첨가하여 감마선 가교에 의해 다당류 함유 고분자 하이드로젤을 제조하였다. 제조된 하이드로젤은 항염증 패치로 사용하기에 우수한 기계적 물성을 나타내었고, 사이토카인 분비를 효과적으로 억제함은 물론 세포독성도 나타나지 않는 것을 확인하였다. 결론적으로 느릅나무 추출 다당류가 함유된 하이드로젤은 항염증패치로써 유용하게 사용될 수 있음을 확인하였다. In this study, polysaccharide-poly(vinyl alcohol) (PVA) hydrogels were prepared by using γ-ray and evaluatedfor potential application as an anti-inflammation patch. Ulmus davidiana var. japonica (UD), one of polysaccharides hasbeen particularly used as an oriental remedy for the treatment of inflammation and ulcers. PVA as a biocompatible polymerand glycerin as a moisturizer were blended with the UD, and its hydrogels were prepared by radiation crosslinking. Characterizations for UD hydrogels were performed by using cytotoxicity assay, antioxidant activity test, and physicochemicaltest such as gel fraction ratio, and swelling behavior. The results showed that these UD hydrogels had excellentphysical properties, anti-inflammation activity, and non-cytotoxicity on the cells. Therefore, these polysaccharidebased-UD hydrogels can be effectively used as an inflammation patch.