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  • Author: Xiao-Ou Ou x
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Abstract

A hairpin shaped DGS, consisting of two tilted slots with a separation angle, is studied as a unit cell in this contribution. It is further served as a microwave resonator for microstrip lowpass filter applications. Two prototype filters that respectively cascade the same unit cells and the scaled cells with a different scale ratio are analyzed. For demonstration purposes, the two prototype filters are optimally developed, fabricated and examined both from numerical simulations and from experimental validations. Results show the cascaded scaled type demonstrator features a high stopband suppression level within a wide frequency band.

Abstract

This contribution presents, for the first time, the design of microwave lowpass filter with ultrawide stopband and low insertion loss based on the log-periodic zig-zag defected ground structure (DGS); the design is specifically evolved from the principle of the log-periodic line antenna and the slotline based DGS. Based on the log-periodic property, studies show that ultra-wideband suppression can be realized by increasing the flare angle or the angle subtended by each element of the slotline DGS. The developed filter therefore shows low insertion loss of 0.7 dB within the passband, sharp transition between the passband and the stopband and ultra-wide suppression band from 2.61-26.5 GHz with a 20 dB suppression level. The DGS architecture is simple and easy to realize, and the design is thus useful in many microwave applications. The fabricated prototype filter validates the study, both from simulations and from measurements.

Abstract

Objective: The objective of the following study is to investigate the relationship between blood lipid levels and carotid intima-media thickness (CIMT) in Shanghai urban population. Materials and Methods: A total of 2504 residents over 40 years old in Jiading District of Shanghai municipality were divided into two groups in terms of the CIMT value 0.7 mm: Thickened group (n = 478) and normal group (n = 2026). All the patients received examinations of height, weight, waist, blood pressure, blood lipid level, hepatic and renal function, oral glucose tolerance test and carotid artery B-ultrasonography. Results: In comparison with those in CIMT normal group, the proportion of males, ages, body mass index, systolic blood pressure and levels of fast blood glucose, total cholesterol (TC), triglyceride (TG) and lowdensity lipoprotein cholesterol (LDL-C) were increased, but the levels of fast insulin were decreased (all P < 0.05). The risks of CIMT thickness were elevated by 19% and 25% as every increase in the standard deviation of the TC and LDL-C levels respectively (95% of confidence interval [CI] 1.08-1.31; 95% CI 1.13-1.37). Statistical analysis showed a significant correlation between CIMT thickness and TC/LDL-C. The levels of TG and high-density lipoprotein cholesterol were not associated with CIMT thickness. Conclusions: Levels of blood TC and LDL-C have significant correlations with the CIMT thickness in Shanghai urban population.

Abstract

Introduction: The extremely high genetic variation and the continuously emerging variants of foot-and-mouth disease virus (FMDV) of Southern African Territory (SAT) serotypes including SAT1, SAT2, and SAT3 make it necessary to develop a new RT-PCR for general use for monitoring viruses based on the updated genome information.

Material and Methods: A FMDV SAT-D8 one-step RT-PCR was established based on the 1D2A2B genes of the SAT serotype viruses with a multiplex primer set. FMDV A, O, C, and Asia 1 serotypes, other vesicular disease viruses, inactivated SAT viruses, and 125 bovine, ovine, caprine and porcine tissue samples collected from the Chinese mainland were included for evaluating the assay.

Results: The new RT-PCR was proven to be specific without cross-reactions with Eurasian FMDV, swine vesicular disease virus (SVDV), Seneca valley virus (SVV), or other common viral pathogens of cattle, sheep, goat, and pig. An around 257 bp-sized amplicon clearly appeared when the inactivated SAT viruses were detected. However, all 125 samples collected from FMDV-susceptible animals from the Chinese mainland which has not known SAT epidemics showed negative results.

Conclusions: A FMDV SAT-D8 one-step RT-PCR is a promising method for primary screening for FMDV SAT serotypes.