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In this study, a broadband and high gain dielectric-rod end-fire antenna are proposed for applications on both the K and Ka bands. By employing the double-ridged waveguide (DRW) feeding structure which is composed of a coaxial line to tapered DRW transition, a parabolic tapered DRW, and a parabolic-tapered flared parallel waveguide section, the impedance bandwidth of this proposed antenna is broadened to 84.5%. The dielectric-rod with the double circular truncated cone structure acted as the main radiator of the proposed antenna is adopted to achieve higher gains and lower side-lobe levels as compared to the traditional circular cone dielectric-rod, while the four-wedges structure inserted in the waveguide is developed as the matching section of the dielectric-rod to further improve the impedance matching. The measured results show that this antenna can be operated in 17.9–44.1 GHz, and the measured gain changes from 9.9 to 15.5 dBi. Moreover, the radiation patterns are demonstrated with observed end-fire characteristic in the overall operating band.

To investigate the effects of simvastatin on atherosclerosis and central aortic pressure in ApoE-knockout (ApoE-/-) mice.Ten 5-week-old male ApoE-/- mice and 5 C57 mice were fed with high-lipid diet for 3 weeks, and then C57 mice (WT group) and 5 ApoE-/- mice (ApoE-/- group) were given 1% carboxymethyl cellulose solution (8 ml·kg-1·d-1), and another 5 ApoE-/- mice (ApoE-/-/S group) were given simvastatin solution (50 mg·kg-1·d-1) by gavege for 3 weeks. The areas of atherosclerotic lesion in aortic root, central aortic pressure and serum lipid levels were examined.No atherosclerotic plaques were observed in WT group. Compared with ApoE-/- group, simvastatin significantly decreased atherosclerotic lesion area in aortic root (89 818.05±16 980.93 μm2 vs 34 937.01±13 280.65 μm2, P0.05). The systolic pressure (SP), mean arterial pressure (MAP), pulse pressure (PP) and diastolic pressure (DP) of central aortic pressure were significantly increased in ApoE-/- group compared with those in WT group (P0.05). Compared to ApoE-/- group, the SP, MAP and PP of central aortic pressure were significantly reduced in ApoE-/-/S group (P0.05). SP and MAP of central aortic pressure were positively correlated with atherosclerotic lesion area (SP: r=0.7152, P=0.0461; PP: r=0.7594， P=0.0288). Compared with WT group, serum triglyceride, total cholesterol and low-density lipoprotein levels were markedly increased in ApoE-/- group (P0.05). Serum high-density lipoprotein level was decreased in ApoE-/- group compared with WT group. No differences in serum triglyceride, total cholesterol, low-density lipoprotein and high-density lipoprotein levels were found between ApoE-/- group and ApoE-/-/S group.Simvastatin can attenuate atherosclerosis of aorta in ApoE-/- mice, which is associated with the reduced central aortic systolic pressure but not with the serum lipids levels.