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Aim: To investigate the inhibitory effects of plumbagin (5-hydroxy-2 methyl-1,4-naphthoquinone) on the invasion and migration and its correlation with matrix metalloproteinase-2 (MMP-2) and urokinase-plasminogen activator (u-PA) in liver cancer HepG2 cells under non-cytotoxic concentrations. Methods: The cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The adhesion, migration and invasion were measured by cell-matrix adhesion assay and Boyden chamber assay. The MMP-2 and u-PA activities were estimated by gelatin and casein-plasminogen zymography. The mRNA and protein levels of MMP-2, u-PA, urokinase-plasminogen activator receptor (u-PAR), tissue inhibitor of metalloproteinase-2 (TIMP-2), plasminogen activator inhibitor-1 (PAI-1), nuclear factor κ B (NF-κB), c-Fos and c-Jun were evaluated by semi-quantitative reverse transcription polymerase chain reaction and western blotting. Also, the binding abilities of NF-κB and activator protein-1 (AP-1) were analyzed by electrophoretic mobility shift assay (EMSA). Results: In this study, plumbagin had exhibited an inhibitory effect on the abilities of adhesion, migration and invasion. The results from zymography showed plumbagin treatment may decrease the activities of MMP-2 and u-PA. Further, the mRNA and protein levels of MMP-2, u-PA and u-PAR were significantly reduced, while TIMP-2 and PAI-1 were elevated by plumbagin treatment. Next, plumbagin significantly decreased the nuclear levels of NF-κB, c-Fos and c-Jun. Also, treating HepG2 cells with plumbagin leads to dose-dependent inhibition on the binding abilities of NF-κB and AP-1. Conclusion: We demonstrated the inhibitory effects of plumbagin on the invasion, migration and adhesion of HepG2 cells, while plumbagin treatment may decrease the expressions of MMP-2 and u-PA and enhance the expressions of TIMP-2 and PAI-1. [ABSTRACT FROM AUTHOR]

The main goal of this letter is to increase the impedance bandwidth of a hybrid bow-tie antenna with end-fire radiation pattern by combining with slots and a patch radiator. The proposed antenna simplify the structure of an antenna with the merits of light weight, low cost, ease fabrication for many wireless and mobile applications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1905–1908, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24463 [ABSTRACT FROM AUTHOR]

This presents a high-impedance ground plane (HIGP) structure for bow–tie antenna in order to improve its radiation performances. The HIGP is a kind of electromagnetic bandgap (EBG) structure to decrease surface waves and to bring an improvement of side lobe level, and reduce the mutual coupling between the two antennas. As compared to proposed antenna without HIGP, the measurement results show a fairly good antenna gain and a 5–10 dB reduction in the back lobes. Several properties of the proposed antenna for WLAN operation such as impedance bandwidth, radiation pattern, and measured gain have been investigated in detail, numerically and experimentally. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2928–2931, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23807 [ABSTRACT FROM AUTHOR]

New design of a dipole antenna with rectangular fractal shape radiator element with two operating bands for radio frequency identification (RFID) is presented. By using fractal shape slot and metal meander patch, the proposed antenna has the wide and dual measured return loss bandwidth. Besides, the omnidirectional radiation pattern of the design antenna cover the entire frequency range including ultra high frequency (UHF, 860–960 MHz) band and microwave (2.45 GHz) band has been obtained. Several properties of the proposed antenna for dual-band operation such as impedance bandwidth, radiation pattern, and measured gain have been investigated numerically and experimentally in detail. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1963–1966, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23512 [ABSTRACT FROM AUTHOR]

A new design of slot antenna by CPW-fed is proposed for ultrawideband (UWB) applications. The proposed antenna consists of a CPW-fed and a pair of symmetry curved radiating slot. The designed tapered slot antenna covers the bandwidth from 3 to 20 GHz. Simulated and measured results of the new design CPW-fed UWB slot antenna show fairly good performance. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 561–564, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22197 [ABSTRACT FROM AUTHOR]

A circularly polarized (CP) stacked antenna for the long range reader of a RFID is studied. The proposed CP antenna using stacked patch technique with a high-impedance ground plane exhibits fairly good performances of 30 MHz bandwidth for 3 dB axial ratio, 70 MHz bandwidth referred to 10 dB return loss at the center frequency of 915 MHz. The gain of the designed antenna is more than 7 dBi over 902–928 MHz and 922–928 MHz and the reading range of the reader reaches 5.5 m. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2248–2250, 2008; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.23658 [ABSTRACT FROM AUTHOR]

A novel and simple structure for a CPW-fed half-loop antenna is presented. The proposed antenna covered the ultra-wideband bandwidth (3.1–10.6 GHz) to even higher band (∼20 GHz) for VSWR <2. Tapered slot structure and half-loop antenna exhibited high band and low band, respectively. The measured results are in fairly good agreements with those of simulated ones. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 684–686, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22223 [ABSTRACT FROM AUTHOR]