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Impulse response function (IRF) and frequency response function (FRF) are the bases and preconditions for acquiring the parameters of a dynamic system and accurately obtaining the dynamic response ...

In order to promote the application of fast broadband MVDR algorithm in engineering, the performance of it is studied by simulation analysis and experimental data validation. On the basis of analysis of the principle of fast MVDR algorithm, Monte Carlo numerical simulation method was used to analyze the directivity curve, beam width and detection threshold of the MVDR algorithm. The actual data at sea was used to verify the validity. The results show that the performance of fast MVDR algorithm is better than CBF algorithm under the condition of high SNR, and it has narrow beam width and strong background noise suppression ability. Its performance is similar to CBF algorithm under the condition of low SNR. Its detection ability is almost the same as that of CBF algorithm in incoherent background noise. MVDR algorithm is suitable for high resolution target detection in high SNR condition.

This study was designed to examine the effects of cinnamaldehyde on coxsackievirus B3 (CVB3)-induced viral myocarditis (VMC) and underlying signaling, with a focus on the toll-like receptor (TLR)4-nuclear factor (NF)-kappaB pathway.The antiviral and myocardial effects of cinnamaldehyde and its metabolite cinnamic acid were evaluated both in vitro and in vivo. Our results showed that cinnamic acid but not cinnamaldehyde reduced the viral titer in CVB3-infected myocardial cells. Our in vivo study demonstrated that intraperitoneal injection of either cinnamaldehyde or cinnamic acid significantly enhanced the survival rate and reduced myocardial viral titer in VMC mice compared with CVB3-infected controls (P0.05). There was no significant difference in effectiveness between the cinnamic acid and the cinnamaldehyde groups (P0.05). Cinnamaldehyde reduced plasma nitric oxide (NO) content, NF-kappaB, inducible nitric oxide synthase and TLR4 expression and decreased inflammatory cell infiltrate in myocardium from VMC mice 7 days after viral inoculation (P0.05). However, these effects were not observed with cinnamic acid treatment. Statistical significance was present between cinnamic acid and cinnamaldehyde in their effects on plasma NO content, NF-kappaB, inducible nitric oxide synthase and TLR4 expression (P0.05).Our data suggest that although cinnamaldehyde has antiviral effects on VMC through its metabolite, cinnamic acid, it directly reduces the inflammation in VMC by inhibiting the TLR4-NF-kappaB signal transduction pathway.