• Title/Summary/Keyword: Unit cell

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Dual-Band Monopole Antenna Design with Mu-Negative Metamaterial Unit Cell (Mu-Negative Metamaterial 단일 셀을 가진 듀얼 대역 모노폴 안테나 설계)

  • Lee, Sang-Jae;Lee, Young-Hun
    • Journal of IKEEE
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    • v.21 no.3
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    • pp.219-226
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    • 2017
  • This paper was studied the double-band monopole antenna design with Mu-negative metamaterial unit cell, which operates at 700MHz and 2.45GHz band. Mu-negative unit cell made of the interdigital capacitor structure to operate a double-band antenna by inserting it into an antenna radiator unit. In addition, the parasitic conductor is implemented on the back side of the antenna radiation part, so that the resonance point of the antenna can be controlled and the bandwidth is improved. Finally, we implemented an antenna operating in the 750MHz UHD band and the 2.45GHz WiFi band. The designed antenna has a size of $200{\times}100mm^2$. Experimental results show that the 8dB bandwidth and gain characteristics at 750MHz band are 320MHz(42.7%), 5.28dB, 6dB bandwidth and gain at 2.45GH are 540MHz (21.6%), -0.46dB. From the experimental results, we confirmed that the resonance point with theoretical value is in agreement with experimental value, and the radiation patterns are have the omnidirectional characteristic in both bands.

Crystallographic Study on Zeolite 4A Reacted with Rubidium Vapor (루비듐 증기와 반응한 제올라이트 4A에 대한 결정학적 연구)

  • Song, Seong-Hwan;Kim, Yang;Han, Young-Wook
    • Journal of the Mineralogical Society of Korea
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    • v.4 no.2
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    • pp.99-107
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    • 1991
  • Three fully dehydrated fully Rb+-exchanged zeolite A single crystals have been prepared by the reduction of all Na+ ions in dehydrated Na12-A by rubidium vapor at various experimental conditions (220 $\leq$ T $\leq$ 33$0^{\circ}C$, 2 $\leq$ t $\leq$24 hours, and 0.1 $\leq$ PRb $\leq$ 1.1 Torr). Their structures were determined by single-crystal X-ray diffraction methods in the space group {{{{ RHO }}m3m (a=12.245(3) A) at 22(1)$^{\circ}C$. In these structures 12.6(2) to 13.5(2) Rb species are found per unit cell, more than the 12 Rb+ ions needed to balance the anionic charge of the zeolite framework, indication that the sorption of Rb0 has occurred. In each structure, three Rb+ ions per unit cell are located at the centers of 8-rings. Beyond that, the fractional occupancies observed are simply explained by two unit cell arrangments. In one, two Rb+ ions are in the sodalite unit near opposite 6-rings, six are in the large cavity near 6-ring, and one is in the large cavity near a 4-ring. In the other, three Rb species in the sodalite cavity (forming a triangle 3.7 A on an edge) each bond (3.4 A) through a 6-ring to an Rb species in the large cavity to give an (Rb6)4+ cluster of symmetry 3m (C3V). Five additional Rb+ ions fill the remaining large-cavity 6-ring sites.

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Antifungal Mechanism of Antifungal Peptide Derived from Cecropin A(1-8)- Melittin(1-12) Hybrid against Aspergillus fumigatus

  • Lee, Dong-Gun;Jin, Zhe-Zhu;Maeng, Cheol-Young;Shin, Song-Yub;Seo, Moo-Yeol;Kim, Kil-Lyong;Hahm, Kyung-Soo
    • Journal of Microbiology and Biotechnology
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    • v.9 no.2
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    • pp.168-172
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    • 1999
  • The antifungal mechanism of the antifungal peptide against Aspergillus fumigatus, $K^{18,19}$-CA(l-8)-ME(l-12), derived from cecropin A(l-8)-melittin(l-12) was investigated by confocal laser scanning microscopy, cell wall regeneration, ATPase activity inhibition, and released potassium ion. By confocal laser scanning microscopy, $K^{18,19}$-CA(l-8)-ME(l-12) was detected on the surface of A. fumigatus, while cecropin A used as a negative control peptide was not detected. The protoplast of A. fumigatus treated with$K^{18,19}$-CA(1-8)-ME(1-12) failed to regenerate the fungal cell walls. Compared with cecropin A, the amount of potassium ion released by $K^{18,19}$-CA(l-8)-ME(l-12) was increased. Furthermore, $K^{18,19}$-CA(l-8)-ME(l-12) inhibited the ATPase activity on the plasma membrane. These results suggested that $K^{18,19}$-CA(l-8)-ME(1-12) acts on the plasma membrane of A. fumigatus and its antifungal action is due to the ion channel or pore formation on the plasma membrane.

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E1/E2 of Hepatitis C Virus Genotype-4 and Apoptosis

  • Zekri, Abdel-Rahman N;Sobhy, Esraa;Hussein, Nehal;Ahmed, Ola S;Hussein, Amira;Shoman, Sahar;Soliman, Amira H;El-Din, Hanaa M Alam
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.7
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    • pp.3131-3138
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    • 2016
  • Several studies have addressed the possible role of hepatitis C virus genotype-4 (HCV GT4) in apoptosis. However, this still not fully understood. In the current study a re-constructed clone of E1/E2 polyprotein region of the HCV GT4 was transfected into the Huh7 cell line and a human apoptotic PCR array of 84 genes was used to investigate its possible significance for apoptosis. Out of the 84 genes, only 35 showed significant differential expression, 12 genes being up-regulated and 23 down-regulated. The highest-up regulated genes were APAF1 (apoptotic peptidase-activating factor 1), BID (BH3 interacting domain death agonist) and BCL 10 (B-cell CLL/lymphoma protein 10) with fold regulation of 33.2, 30.1 and 18.9, respectively. The most down-regulated were FAS (TNF receptor super family), TNFRSF10B (tumor necrosis factor receptor super-family member 10b) and FADD (FAS-associated death domain) with fold regulation of -30.2, -27.7 and -14.9, respectively. These results suggest that the E1/E2 proteins may be involved in HCV-induced pathogenesis by modulating apoptosis through the induction of the intrinsic apoptosis pathway and disruption of the BCL2 gene family.

Sepsis induces variation of intestinal barrier function in different phase through nuclear factor kappa B signaling

  • Cao, Ying-Ya;Wang, Zhong-Han;Xu, Qian-Cheng;Chen, Qun;Wang, Zhen;Lu, Wei-Hua
    • The Korean Journal of Physiology and Pharmacology
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    • v.25 no.4
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    • pp.375-383
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    • 2021
  • The intestinal barrier function disrupted in sepsis, while little is known about the variation in different phases of sepsis. In this study, mouse models of sepsis were established by caecal ligation and puncture (CLP). The H&E staining of sections and serum diamine oxidase concentration were evaluated at different timepoint after CLP. TUNEL assay and EdU staining were performed to evaluate the apoptosis and proliferation of intestinal epithelium. Relative protein expression was assessed by Western blotting and serum concentrations of pro-inflammatory cytokines was measured by ELISA. The disruption of intestinal barrier worsened in the first 24 h after the onset of sepsis and gradually recovered over the next 24 h. The percentage of apoptotic cell increased in the first 24 h and dropped at 48 h, accompanied with the proliferative rate of intestinal epithelium inhibited in the first 6 h and regained in the later period. Furthermore, the activity of nuclear factor kappa B (NF-κB) presented similar trend with the intestinal barrier function, shared positive correction with apoptosis of intestinal epithelium. These findings reveal the conversion process of intestinal barrier function in sepsis and this process is closely correlated with the activity of NF-κB signaling.

Output Power Characteristics of CPV Solar Cell due to Non-uniform Illumination (고집광 태양전지의 비균등 조사에 의한 출력특성)

  • Shin, Goo-Hwan;Ryu, Kwang-Sun;Cha, Won-Ho;Myung, Noh-Hoon;Kim, Young-Sik;Kang, Gi-Hwaw
    • 한국태양에너지학회:학술대회논문집
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    • 2011.04a
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    • pp.269-274
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    • 2011
  • A solar cell is primary parts to produce electrical energy from the Sun. And, we can utilize those solar cells as a power generation system in home, factory, and so on. In order to make proper power, the solar cells are configured in series and parallel lay down. In condition of uniform illumination, the solar array will produce an enough power by photovoltaic effects from the solar cells. In case of non-uniform illumination on the solar cells, the power will be dramatically decreased compared to design. Fortunately, there were so many research outputs regarding the illumination effects on solar array. In this work, we tried to find out the non-uniform effects on unit CPV solar cell, because there were no research outputs for unit CPV solar cell considering illumination. The CPV solar cell was used in CPV system to make a power by the Sun. We chosen the triple junction solar cell of GaAsInP2Ge for simulation, which has a 30 % of conversion efficiency. By simulation, we obtained the output performance of CPV solar cells in condition of various illumination by using Hamming Window function. Its performance was degraded by 10 % to 50 % depending illumination conditions.

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