http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Type II Collagen으로 유도된 관절염에 대한 강활(羌活), 독활(獨活) 배합약물의 억제 효과
윤호석,이영철,이장천,Yoon, Ho-Suk,Lee, Young Cheol,Lee, Jang-Cheon 대한한의학방제학회 2013 大韓韓醫學方劑學會誌 Vol.21 No.1
Objectives : To clarify the anti-arthritic activity of Ostericum koreanum Maxim. (OS) plus Aralia continentalis Kitagawa (AC) in vivo. Methods : All mice were immunized with bovine type II collagen. After a second collagen immunization, mice were treated with OS plus AC once a day for 7 weeks. Oral administration of OS plus AC (200 or 50 mg/kg) significantly suppressed the progression of CIA, which extend is comparable to that of methotrexate (MTX, 0.3 mg/kg), a positive control. The severity of arthritis within the knee joints was evaluated by histological assessment of cartilage destruction and pannus formation. Results : Administration of OS plus AC significantly suppressed the progression of CIA and inhibited the production of TNF-${\alpha}$ and IL-6 in serum. The erosion of cartilage was dramatically reduced in mouse knees after treatment with OS plus AC. In conclusion, our results demonstrates that OS plus AC significantly suppressed the progression of CIA and that this action was characterized by the decreased production of IL-6, IFN-${\gamma}$ and collagen II specific antibody in serum, CD3+CD69+ T cells, MHC class II+/CD11c+ (in DLN), CD11b+Gr-1+ cells (in PBMC), CD11b +Gr-1+ cells, B220+/CD23+ (in paw joint). Conclusions : The the levels of IFN-${\gamma}$ in the culture supernatant of splenocytes stimulated with CD3/CD28 or collagen were dramatically decreased, while those of IL-4 was increased. In the serum of OS and AC-treated mice, the levels of IgM RA factor were decreased.
비귀금속 촉매에서 사용되는 질소 전구체가 산소 환원 반응의 활성에 미치는 영향
윤호석 ( Ho Seok Yoon ),정원석 ( Won Suk Jung ) 한국화학공학회 2022 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.60 No.1
고가의 귀금속 촉매는 고분자 전해질 연료전지의 상업화에 걸림돌로 인식되어 저가의 비귀금속 촉매 연구가 활발하다. 본 연구에서는 Fe-N-C 촉매를 킬레이팅이 가능한 4가지 다른 질소 전구체 N,N,N’,N’-detramethylethylenediamine(TMEDA), 1,2-ethylenediamine (EDA), m-dicyanobenzene (DCB), dicyandiamide (DCDA)를 이용하여 700, 800, 900, 1000 ℃에서 합성하였다. 촉매의 물리적 특성은 주사전자현미경, X선 회절분석기, 자동원소분석기를 이용하여 분석하였다. 이를 통해 촉매 표면 형태 및 원소의 분산도와 에너지 분산형 X-선 분광을 적용하여 Fe의 함량을 확인하였다. 또한 비금속 원소의 함량과 Fe의 담지 여부 등을 확인하였다. 전기화학적 특성은 순환 전압전류법과 선형주사전위법을 통해 촉매의 전기화학적 산소 환원에 대한 활성과 전자전달수 등을 분석하였다. 결과에 따르면 질소 전구체로 EDA를 사용하여 800 °C의 소성온도에서 합성한 촉매가 가장 높은 산소 환원 활성을 보였다. 이 연구 결과는 고가의 귀금속을 대체하기 위한 노력에 도움이 될 것으로 예상된다. Iron and nitrogen coordinated carbon catalyst (Fe-N-C) is the most promising non-precious metal catalyst (NPMC) studied to alternate the Pt-group oxygen reduction reaction (ORR) catalyst. In this work, Fe/N/C type catalysts are prepared by four different nitrogen precursors; N, N, N’, N’-tetramethylethylenediamine (TMEDA), 1,2-ethylenediamine (EDA), m-dicyanobenzene (DCB), dicyandiamide (DCDA) which can chelate a transition metal; In addition, the catalysts conducted the pyrolysis process at four different temperatures of 700, 800, 900, 1000 ℃ to investigate the ORR activities depend on pyrolysis temperature and to find an appropriate temperature. The characterizations of catalysts were investigated by scanning electron microscope-energy dispersive X-ray spectrometer (SEM-EDS), X-ray diffraction (XRD), and element analysis (EA). The electrocatalytic activity was measured by ORR polarization, also the electron transfer number was calculated from the slope of the K-L plot. The FeNC-EDA-800 which were prepared at pyrolysis temperature of 800 °C with EDA showed better ORR activity than the other catalysts.
Ho Seok Yoon(윤호석),Jong Chan Bu(부종찬),Won Suk Jung(정원석) 한국신재생에너지학회 2021 한국신재생에너지학회 학술대회논문집 Vol.2021 No.7
PEMFCs are eco-friendly generating systems that have a high efficiency of energy conversion rate changing the chemical reaction of the hydrogen into electrical energy directly. Because of the sluggish reaction rate of oxygen reduction reaction (ORR) in the cathode of PEMFCs, the entire cell performance is decreased. For these reasons, highly active ORR catalysts are required. Pt-group catalysts are shown the best ORR catalytic performance. But because of the high prices of platinum and low electrochemical stability, many researchers have studied non-precious metal catalysts (NPMCs) to alternate Pt-group catalysts. In this work, we prepared Fe@CN-F, Fe@CN-S which are M-N-C type ORR catalysts, via co-doping of fluorine or sulfur with nitrogen on the carbon support. Heteroatoms were doped on the surface of carbon support via the pyrolysis process at 800℃ Fe@CN-S was shown a large amount of nitrogen than Fe@CN, and the ratio of N-functional group; pyridinic N and graphitic N which have advantages of ORR activity. Fe@CN-F almost the same nitrogen contents as Fe@CN but showed the same onset potential as Fe@CN-S. C-F bonds in Fe@CN-S seem to occur as new active sites. Fe@CN-F and Fe@CN-S were shown the same onset potential of 0.83 V in acidic media. Fe@CN-F was shown a great inset potential of 0.98 V that was only 20 mV different from commercial Pt/C (40 wt%, JM). In alkaline media.