An mmWave Dual-Band Integrated Substrate Gap Waveguide Single Cavity Filter with Frequency Selectivity

A novel dual-band ISGW cavity filter with enhanced frequency selectivity is proposed in this paper by utilizing a multi-mode coupling topology.Its cavity is designed to control the number of modes,and then the ports are determined by analyzing the coupling relationship between these selected modes.By synthesizing the coupling matrix of the filter,a nonresonating node(NRN)structure is introduced to flexibly tune the frequency of modes,which gets a dualband and quad-band filtering response from a tri-band filter no the NRN.Furthermore,a frequency selective surface(FSS)has been newly designed as the upper surface of the cavity,which significantly improves the bad out-of-band suppression and frequency selectivity that often exists in most traditional cavity filter designs and measurements.The results show that its two center frequencies are f01=27.50 GHz and f02=32.92GHz,respectively.Compared with the dual-band filter that there is no the FSS metasurface,the out-of-band suppression level is improved from measured 5 dB to18 dB,and its finite transmission zero(FTZ)numbers is increased from measured 1 to 4 between the two designed bands.Compared with the tri-band and quadband filter,its passband bandwidth is expanded from measured 1.17%,1.14%,and 1.13% or 1.31%,1.50%,0.56%,and 0.57% to 1.71% and 1.87%.In addition,the filter has compact,small,and lightweight characteristics.

An ISGW Filtering Antenna with Spurious Modes and Surface Wave Suppression for Millimeter Wave Communications

In this paper,an integrated substrate gap waveguide(ISGW)filtering antenna is proposed at millimeter wave band,whose surface wave and spurious modes are simultaneously suppressed.A secondorder filtering response is obtained through a coupling feeding scheme using one uniform impedance resonator(UIR)and two stepped-impedance resonators(SIRs).To increase the stopband width of the antenna,the spurious modes are suppressed by selecting the appropriate sizes of the ISGW unit cell.Furthermore,the ISGW is implemented to improve the radiation performance of the antenna by alleviating the propagation of surface wave.And an equivalent circuit is investigated to reveal the working principle of ISGW.To demonstrate this methodology,an ISGW filtering antenna operating at a center frequency of 25 GHz is designed,fabricated,and measured.The results show that the antenna achieves a stopband width of 1.6f0(center frequency),an out-of-band suppression level of 21 dB,and a peak realized gain of 8.5 dBi.

STING-mediated IL-6 Inhibits OATP1B1 Expression via the TCF4 Signaling Pathway in Cholestasis

Background and Aims Organic anion-transporting polypeptides(OATPs)play a crucial role in the transport of bile acids and bilirubin.In our previous study,interleukin 6(IL-6)reduced OATP1B3 levels in cholestatic disease.However,it remains unclear whether IL-6 inhibits OATP1B1 expression in cholestatic diseases.This study aimed to investigate whether IL-6 can inhibit OATP1B1 expression and explore the underlying mechanisms.Methods The effect of stimulator of interferon genes(STING)signaling on inflammatory factors was investigated in a cholestatic mouse model using RT-qPCR and enzyme-linked immunosorbent assay.To assess the impact of inflammatory factors on OATP1B1 expression in hepatocellular carcinoma,we analyzed OATP1B1 expression by RT-qPCR and Western Blot after treating PLC/PRF/5 cells with TNF-α,IL-1β,and IL-6.To elucidate the mechanism by which IL-6 inhibits OATP1B1 expression,we examined the expression of the OATP1B1 regulator TCF4 in PLC/PRF/5 and HepG2 cells using RT-qPCR and Western Blot.The interaction mechanism betweenβ-catenin/TCF4 and OATP1B1 was investigated by knocking downβ-catenin/TCF4 through siRNA transfection.Results The STING inhibitor decreased inflammatory factor levels in the cholestatic mouse model,with IL-6 exhibiting the most potent inhibitory effect on OATP1B1.IL-6 downregulatedβ-catenin/TCF4,leading to decreased OATP1B1 expression.Knocking-downβ-catenin/TCF4 counteracted theβ-catenin/TCF4-mediated repression of OATP1B1.Conclusions STING-mediated IL-6 up-regulation may inhibit OATP1B1,leading to reduced transport of bile acids and bilirubin by OATP1B1.This may contribute to altered pharmacokinetics in patients with diseases associated with increased IL-6 production.