ABSTRACT:A novel multilayer broadband active-slot power divider is proposed for the first time. As compared to the conventional active multilayer power divider [7], whose 3-dB bandwidth of small-signal gain is typically about 40%, the overall 3-dB bandwidth of the small-signal gain of the proposed multilayer active-slot power divider is about 52%. Through the modification of the T-junction, the proposed power divider is able to provide the characteristics of balance, low loss, and broad band. The proposed device can also provide the possibility of uneven power outputs under appropriate load modifications and amplifications.

No abstract

BackgroundChemotherapy is the mainstream treatment modality for invasive breast cancer. Nonetheless, chemotherapy-associated adverse events can result in a patient terminating treatment. We show that transient receptor potential channel 1 (TRPC1) expression level predicts breast cancer sensitivity to doxorubicin (DOX) and pulsed electromagnetic field (PEMF) therapies.MethodsThe effects of PEMFs were examined with respect to: 1) the growth of MCF-7 cells in vitro; 2) MCF-7 tumors implanted into a chicken chorioallantoic membrane (CAM) model and; 3) patient-derived and MCF-7 breast cancer xenografts in mice.Potential synergisms between DOX and PEMF therapies were examined in these model systems and under conditions of TRPC1 overexpression or silencing in vitro.ResultsPEMF exposure impaired the survival of MCF-7 cells, but not that of nonmalignant MCF10A breast cells. The effects of PEMF- and DOX-therapies synergized in vitro at compromising MCF-7 cell growth. Synergism could be corroborated in vivo with patient-derived xenograft mouse models, wherein PEMF exposure alone or in combination with DOX reduced tumor size. Stable overexpression of TRPC1 enhanced the vulnerability of MCF-7 cells to both DOX and PEMF exposure and promoted proliferation, whereas chronic DOX exposure reduced TRPC1 expression, induced chemoresistance, precluded response to PEMF exposure and mitigated proliferation. Markers of metastasis including SLUG, SNAIL, VIMENTIN, and E-CADHERIN as well as invasiveness were also positively correlated with TRPC1 channel expression.ConclusionThe presented data supports a potential role of PEMF-therapy as an effective companion therapy to DOX-based chemotherapy for the treatment of breast cancers characterized by elevated TRPC1 expression levels.

When taking into consideration the dispersion in the practical LHM, our analysis shows that directive radiation can be established with both high directivity and acceptable radiation power within a certain frequency range. The far-field radiation pattern and the high directivity exhibit the potential application of the LHM in future directive antenna techniques. ACKNOWLEDGMENTSThis work is supported by the National Basic Research Program of China (under project no. 2004CB719800) In this paper, a novel elliptic filter, centered at 6.65 GHz with sharp and deep rejection outside the passband is fabricated. The dimensions of the filter are comparable to those of /4 open-loop resonators. The advantage of this proposed filter is that it can provide a broadband response. To demonstrate the proposed design, an elliptic filter with about 0.6-dB ripples and measured insertion loss of about 1.5 dB is designed and fabricated. THE PROPOSED DESIGNA schematic view of the novel unit cell design of the band-pass filter is shown in Figure 1(a). All the widths of the lines are kept at 10-mils wide, which corresponds to the width of 50⍀ at the designed centre frequency. Instead of using two quarter-length squared loops as in [2,3], the proposed unit cell, as shown in Figure 1(a), contains two disjoint loops interposed with each other. The two disjoint loops are overlapped at the middle so as to create a higher coupling to the output side. Through this interposing connection, electric and magnetic modes similar to those in [3] can be generated. The proposed unit cell is antisymmetrical along the horizontal line and possesses several small gaps (of approx. 5 mils) at opposite corners of the two loops. These gaps help to provide isolation between any two halves of the loops. The unit-cell physical dimensions are given in Table 1. The input signal is injected at one corner of the structure whereas the output signal is tapped at the centre of the transmission line.To further improve the rolloff and the fractional bandwidth, the proposed unit cell is next cascaded to form an elliptic filter, as shown in Figure 1(b). The physical dimensions of the cascaded cell are also included in Table 1. To improve the overall matching of the structure, the unit cells are connected at the centre of the transmission line, where the length of this transmission is kept as short as possible. By varying the length L8, one can vary the amount of coupling to the output side. EXPERIMENTAL RESULTS AND DISCUSSIONSThe proposed elliptic filter is designed with the aid of IE3D. The design is fabricated on a substrate of permittivity 10.2 and thickness 25 mils. Figure 2(a) and (b) show the S-parameter responses of the single and cascaded unit cells. As noted from the figures, the passband response improved dramatically as more unit cells are cascaded. A sharper rolloff is obtained when three unit cells are cascaded. From our experimentation, we noted that the length L8 plays a very crucial role in introducing multiple poles in the passband. In our experimentation,...