Experimental analysis of rotating bridge structural responses to existing railway train loads via time-frequency and Hilbert-Huang transform energy spectral analysis.

With the rapid development of national infrastructure projects, there has been a significant increase in intersecting lines in transportation construction. As a result, rotating bridges are increasingly used in engineering projects that span existing railway lines. In order to study the spatial response characteristics and vibration wave transmission mechanisms of the rotating bridge structure under the loading of existing railway trains, field experiments and numerical analyses were conducted. The response characteristics of these bridges were investigated under different types and speeds of adjacent existing lines. A comprehensive methodology has been proposed, integrating the time domain spectrum and the Hilbert-Huang Transform (HHT) energy spectrum for signal processing and vibration analysis. The analysis was carried out using MATLAB 2018a software. This methodology was applied to analyze the test data. The results show that significant resonance phenomenon occurs in the girders of the rotating bridge under the loading of trains on the existing line. The low-frequency component f1 (2-5 Hz) is the primary factor contributing to the amplification of the acceleration response in the rotating bridge, while f3 (10-13 Hz) plays a secondary role. The frequency distribution characteristics of vibration waves caused by train loads on the existing line have a significant influence on the acceleration response of the rotating bridge's girders. The predominant frequency of vibration waves at each measuring point along the transmission path shows a trend of decreasing → increasing → decreasing. The impact on the rotating bridge structure of vibration waves generated by low-speed freight trains on existing railways is greater. The research findings are of great importance for studying the dynamic response of rotating bridges adjacent to existing railway lines.

Transcriptomic and proteomic analyses of Cucurbita ficifolia Bouché (Cucurbitaceae) response to Fusarium oxysporum f.sp. cucumerium.

BACKGROUND: Fusarium oxysporum f. sp. cucumerinum (FOC) is the causal agent of cucumber Fusarium wilt, which can cause extensive damages and productivity losses. Cucurbita ficifolia Bouché (Cucurbitaceae) is usually used as rootstock for cucumber because of its excellent resistance to Fusarium wilt. Our previous study found that C.ficifolia has high FOC resistance, the underlying mechanism of which is unclear. RESULTS: Transcriptome and proteome profiling was performed on the basis of RNA-Seq and isobaric tag for relative and absolute quantitation technology to explore the molecular mechanisms of the response of Cucurbita ficifolia Bouché to Fusarium oxysporum f. sp. cucumerium infection. Comparative analyses revealed that 1850 genes and 356 protein species were differentially regulated at 2d and 4d after FOC inoculation. However, correlation analysis revealed that only 11 and 39 genes were differentially regulated at both the transcriptome and proteome levels after FOC inoculation at 2d and 4d, respectively. After FOC inoculation, plant hormones signal transduction, transcription factors were stimulated, whereas wax biosynthesis and photosynthesis were suppressed. Increased synthesis of oxidative-redox proteins is involved in resistance to FOC. CONCLUSIONS: This study is the first to reveal the response of C. ficifolia leaf to FOC infection at the transcriptome and proteome levels, and to show that FOC infection activates plant hormone signaling and transcription factors while suppressing wax biosynthesis and photosynthesis. The accumulation of oxidative-redox proteins also plays an important role in the resistance of C. ficifolia to FOC. Results provide new information regarding the processes of C. ficifolia leaf resistance to FOC and will contribute to the breeding of cucumber rootstock with FOC resistance.

The complete chloroplast genome of Rubus lambertianus var. paykouangensis, an edible wild plant.

Rubus lambertianus Ser. var. paykouangensis (Levl.) Hand.-Mazz. is great important in the phylogeny and evolution of the genus Rubus L. in the family Rosaceae. The chloroplast genome of R. lambertianus var. paykouangensis reported in this study is 156177 bp in length, and it has an average GC content of 37.18%. The complete chloroplast genome showed a typical quadripartite structure, comprising a small single copy (SSC) region (18,730 bp) and a large single copy (LSC) region (85,883 bp), both of which were separated by a pair of inverted repeats (IRs, 25,782 bp). This plastome was discovered to contain 129 different genes (112 unique), including 85 protein-coding genes (79 unique), 36 tRNA genes (29 unique), and 8 rRNA genes (4 unique). The published chloroplast genome of R. lambertianus var. paykouangensis will provide a significant insight into elucidating the phylogenetic relationship of taxa within the genus Rubus of the family Rosaceae.