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1
Development of a Kilowatt Class PEMFC Stack using Au-Coated LF11 Al Alloy Bipolar Plates

( Ming Hua Wang ),( Kee Do Woo ),( Dong Keon Kim ),( Xin Jian Zhu ),( Sheng Sui ) 대한금속재료학회 ( 구 대한금속학회 ) 2006 METALS AND MATERIALS International Vol.12 No.4
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Investigations on alternative material for bipolar plates of PEMFC (polymer electrolyte membrane fuel cell) are becoming a research hotspot for many fuel cell researchers. In this paper, LF11 Al alloy bipolar plates via a surface plasma Au plating preparation were applied as bipolar plates. Performances and duration times of PEMFC single cells using graphite; Au-coated LF11 Al bipolar (ALABP) and Au-coated 316L stainless steel plates were compared. It was shown that ALABP exhibited preferable properties. Based on the preparations illustrated above, a kilowatt class proton exchange membrane fuel cell stack consisting of 30 cells was successfully assembled. Pure hydrogen and air were used as the fuel and oxidant, respectively, in the stack. External humidification was employed and cycle cooling water was used to remove the heat from the reaction in order to maintain a constant temperature. A Nafion 1135 membrane and Johnson-Matthy platinum on carbon with a Pt loading of 0.4㎎/㎠ were adopted as the electrolyte and catalyst, respectively. The working temperature of the stack ranged from 25 to 100℃. The stack typically worked well under conditions in which the pressure ratio of H2/air was 0.2/0.22 MPa. The output power, current and voltage were 1-1.3 ㎾, 40-80 A, and 26-20 V, respectively. The normal current density of the electrode was 200-800 ㎃/㎠, and the energy efficiency of the stack was 51%.
2
20(S)-Protopanaxadiol Induces Human Breast Cancer MCF-7 Apoptosis through a Caspase-Mediated Pathway

Zhang, Hong,Xu, Hua-Li,Fu, Wen-Wen,Xin, Ying,Li, Mao-Wei,Wang, Shuai-Jun,Yu, Xiao-Feng,Sui, Da-Yun Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.18
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20(S)-Protopanaxadiol (PPD), a ginsenoside isolated from Pananx quinquefolium L., has been shown to inhibit growth and proliferation in several cancer cell lines. The aim of this study was to evaluate its anticancer activity in human breast cancer cells. MCF-7 cells were incubated with different concentrations of 20(S)-PPD and cytotoxicity was evaluated by MTT assay. Occurrence of apoptosis was detected by DAPI and Annexin V-FITC/PI double staining. Mitochondrial membrane potential was measured with Rhodamine 123. The Bcl-2 and Bax expression were determined by Western blot analysis. Caspase activity was measured by colorimetric assay. 20(S)-PPD dose-dependently inhibited cell proliferation in MCF-7 cells, with an $IC_{50}$ value of $33.3{\mu}M$ at 24h. MCF-7 cells treated with 20(S)-PPD presented typical apoptosis, as observed by morphological analysis in cell stained with DAPI. The percentages of annexin V-FITC positive cells were 8.92%, 17.8%, 24.5% and 30.5% in MCF-7 cells treated with 0, 15, 30 and $60{\mu}M$ of 20(S)-PPD, respectively. Moreover, 20(S)-PPD could induce mitochondrial membrane potential loss, up-regulate Bax expression and down-regulate Bcl-2 expression. These events paralleled activation of caspase-9, -3 and PARP cleavage. Apoptosis induced by 20(S)-PPD was blocked by z-VAD-fmk, a pan-caspase inhibitor, suggesting induction of caspase-mediated apoptotic cell death. In conclusion, the 20(S)-PPD investigated is able to inhibit cell proliferation and to induce cancer cell death by a caspase-mediated apoptosis pathway.
3
Bradyrhizobium spp. and Sinorhizobium fredii are Predominant in Root Nodules of Vigna angularis, a Native Legume Crop in the Subtropical Region of China

Li Li Han,En Tao Wang,Yang Li Lu,Yong Fa Zhang,Xin Hua Sui,Wen Feng Chen,Wen Xin Chen 한국미생물학회 2009 The journal of microbiology Vol.47 No.3
Adzuki bean (Vigna angularis) is an important legume crop native to China, but its rhizobia have not been well characterized. In the present study, a total of 60 rhizobial strains isolated from eight provinces of China were analyzed with amplified 16S rRNA gene RFLP, IGS-RFLP, and sequencing analyses of 16S rRNA, atpD, recA, and nodC genes. These strains were identified as genomic species within Rhizobium, Sinorhizobium, Mesorhizobium, Bradyrhizobium, and Ochrobactrum. The most abundant groups were Bradyrhizobium species and Sinorhizobium fredii. Diverse nodC genes were found in these strains, which were mainly co-evolved with the housekeeping genes, but a possible lateral transfer of nodC from Sinorhizobium to Rhizobium was found. Analyses of the genomic and symbiotic gene backgrounds showed that adzuki bean shared the same rhizobial gene pool with soybean (legume native to China) and the exotic Vigna species. All of these data demonstrated that nodule formation is the interaction of rhizobia, host plants, and environment characters.