Investigation of hydrogen embrittlement behavior in X65 pipeline steel under different hydrogen charging conditions

The hydrogen effect on a X65 carbon steel was investigated by tensile tests under both ex-situ and in-situ hydrogen charging conditions. The fractured samples were characterized and compared using a combination of scanning electron microscopy, electron backscattering diffraction, and energy-dispersive spectroscopy. The work highlights that the in-situ hydrogen charging is a necessity for investigation of hydrogen detrimental effects on the studied material, where a pronounced reduction in fracture elongation, the evolution of secondary cracks on gauge surface, and the corresponding brittle fractography were thoroughly characterized after in-situ testing. The reason resides in the rapid hydrogen outgassing effect, which was proved by Fick's law-based diffusion models. Then the interrupted tensile tests were performed to track the crack initiation and propagation behavior. The results show that the majority of cracks initiated at the interfaces of MnS and Al2O3 inclusions or between inclusions and matrix, which attributes to the elevated stress concentration around the inclusions. Moreover, the cracks were found to propagate along the {110} slip planes.publishedVersio

Comparative Proteomic Analysis of Irradiation-Induced Radioresistant Breast Cancer Cells Using Label-Free Quantitation

Background: Breast cancer poses severe threats to human health as radioresistance becomes increasingly prevalent. The mechanisms of radioresistance are hard to expound completely. This study aims to explore proteomic changes of radioresistance, which will help elucidate the potential mechanisms responsible for breast cancer radioresistance and explore potential therapeutic targets. Methods: A radioresistant breast cancer cell line was established by repeated irradiation. Liquid Chromatograph Mass Spectrometer (LC–MS) was used to quantify protein expression. Proteomic changes associated with radioresistance were evaluated by proteomic analysis. Further, cell radioresistance and several identified proteins were verified in in vitro experiments. Results: In the study, more than 3000 proteins were detected, 243 of which were identified as up-regulated proteins and another 633 as down-regulated proteins. Gene Ontology (GO) enrichment analysis indicated that these proteins were mainly expressed in the lysosome and ribosome, associated with coenzyme binding and the structural constituent of the ribosome, involved in mitotic cytokinesis and ribonucleoprotein complex biogenesis. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that many biological processes were extensively altered, particularly spliceosome and thermogenesis. It is worth noting that the functions and pathways related to ribosomes were significantly enriched, therefore ribosomal proteins (RPL6 and RPS13) were identified through western blot and highly expressed in relatively radiosensitive cells. Additionally, several identified proteins, including S100A4, RanBP9, and ISG15, were also verified to be differentially expressed in different radiosensitive cells. Conclusions: Our results provide a framework for further studies into the mechanisms of radioresistance and serve as a basis to construct a predictive model of radioresistance in breast cancer. Ribosome may participate in the radioresistance of breast cancer, which provides new insights into the proteomic characteristics of the mechanisms of radioresistance

Experimental and numerical study on hydrogen-induced failure of X65 pipeline steel

Hydrogen-induced fracture of X65 pipeline steel under in -situ electrochemical charging is investigated by using slow strain-rate tensile (SSRT) test, hydrogen diffusion test, fractography analysis, and finite element simulation. Smooth and notched tensile specimens with varying notch radii are utilized to ascertain the impact of stress triaxiality on hydrogen embrittlement (HE) susceptibility. A fully coupled model, H-CGM+, capable of simulating the synergy between hydrogen-enhanced plasticity and decohesion, is employed. The simulation proficiently replicates both the global stress-strain trajectories and the local failure initiation sites of the in -situ SSRT tests. The findings indicate a predominance of dislocation trapping hydrogen mechanism in HE, with crack inception at the notch surface where local plastic strain peaks, subsequently advancing towards the center of the specimen. Notably, an inverse relationship is observed between HE susceptibility and stress triaxiality. A hydrogen-induced failure criterion, defined as a critical combination of local hydrogen concentration and plastic strain, is derived. The failure criterion is found to be independent of stress triaxiality, which serves as a good reference for safety assessment of hydrogen pipelines

Transcriptome differential expression analysis of defoliation in different lemon varieties under drought treatment.

'Allen Eureka' is a bud variety of Eureka lemon with excellent fruiting traits, but severe winter defoliation affects the following year's yield, and the response mechanism of lemon defoliation is currently unknown. Two lemon cultivars ('Allen Eureka' and 'Yunning No. 1') with different defoliation traits were used as materials to investigate the molecular regulatory mechanisms of different leaf abscission periods in lemons. The petiole abscission zone was collected at three different defoliation stages, namely, the predefoliation stage (k15), the middefoliation stage (k30), and the postdefoliation stage (k45). Transcriptome sequencing was performed to analyze the gene expression differences between these two cultivars. A total of 1141, 2695, and 1433 differentially expressed genes (DEGs) were obtained in k15, k30, and k45, respectively, and the number of DEGs in k30 was the largest. GO analysis revealed that the DEGs between the two cultivars were mainly enriched in processes related to hydrolase activity, chitinase activity, oxidoreductase activity, and transcription regulator activity in the defoliation stages. KEGG analysis showed that the DEGs were concentrated in k30, which involved plant hormone signal transduction, phenylpropanoid biosynthesis, and biosynthesis of amino acids. The expression trends of some DEGs suggested their roles in regulating defoliation in Lemon. Seven genes were obtained by WGCNA, including sorbitol dehydrogenase (CL9G068822012_alt, CL9G068820012_alt, CL9G068818012_alt), abscisic acid 8'-hydroxylase (CL8G064053012_alt, CL8G064054012_alt), and asparagine synthetase (CL8G065162012_alt, CL8G065151012_alt), suggesting that these genes may be involved in the regulation of lemon leaf abscission

Transcriptome differential expression analysis of defoliation of two different lemon varieties

‘Allen Eureka’ is a bud variety of Eureka lemon with excellent fruiting traits. However, it suffers from severe winter defoliation that leads to a large loss of organic nutrients and seriously affects the tree’s growth and development as well as the yield of the following year, and the mechanism of its response to defoliation is still unclear. In order to investigate the molecular regulatory mechanisms of different leaf abscission periods in lemon, two lemon cultivars (‘Allen Eureka’ and ‘Yunning No. 1’) with different defoliation traits were used as materials. The petiole abscission zone (AZ) was collected at three different defoliation stages, namely, the pre-defoliation stage (CQ), the mid-defoliation stage (CZ), and the post-defoliation stage (CH). Transcriptome sequencing was performed to analyze the gene expression differences between these two cultivars. A total of 898, 4,856, and 3,126 differentially expressed genes (DEGs) were obtained in CQ, CZ, and CH, respectively, and the number of DEGs in CZ was the largest. GO analysis revealed that the DEGs between the two cultivars were mainly enriched in processes related to oxidoreductase, hydrolase, DNA binding transcription factor, and transcription regulator activity in the defoliation stages. KEGG analysis showed that the DEGs were concentrated in CZ and involved plant hormone signal transduction, phenylpropanoid biosynthesis, glutathione metabolism, and alpha-linolenic acid metabolism. The expression trends of some DEGs suggested their roles in regulating defoliation in lemon. Eight gene families were obtained by combining DEG clustering analysis and weighted gene co-expression network analysis (WGCNA), including β-glucosidase, AUX/IAA, SAUR, GH3, POD, and WRKY, suggesting that these genes may be involved in the regulation of lemon leaf abscission. The above conclusions enrich the research related to lemon leaf abscission and provide reliable data for the screening of lemon defoliation candidate genes and analysis of defoliation pathways

Different heatmap of module-trait associations.

’Allen Eureka’ is a bud variety of Eureka lemon with excellent fruiting traits, but severe winter defoliation affects the following year’s yield, and the response mechanism of lemon defoliation is currently unknown. Two lemon cultivars (’Allen Eureka’ and ’Yunning No. 1’) with different defoliation traits were used as materials to investigate the molecular regulatory mechanisms of different leaf abscission periods in lemons. The petiole abscission zone was collected at three different defoliation stages, namely, the predefoliation stage (k15), the middefoliation stage (k30), and the postdefoliation stage (k45). Transcriptome sequencing was performed to analyze the gene expression differences between these two cultivars. A total of 1141, 2695, and 1433 differentially expressed genes (DEGs) were obtained in k15, k30, and k45, respectively, and the number of DEGs in k30 was the largest. GO analysis revealed that the DEGs between the two cultivars were mainly enriched in processes related to hydrolase activity, chitinase activity, oxidoreductase activity, and transcription regulator activity in the defoliation stages. KEGG analysis showed that the DEGs were concentrated in k30, which involved plant hormone signal transduction, phenylpropanoid biosynthesis, and biosynthesis of amino acids. The expression trends of some DEGs suggested their roles in regulating defoliation in Lemon. Seven genes were obtained by WGCNA, including sorbitol dehydrogenase (CL9G068822012_alt, CL9G068820012_alt, CL9G068818012_alt), abscisic acid 8’-hydroxylase (CL8G064053012_alt, CL8G064054012_alt), and asparagine synthetase (CL8G065162012_alt, CL8G065151012_alt), suggesting that these genes may be involved in the regulation of lemon leaf abscission.</div

Different varieties of differential genes.

’Allen Eureka’ is a bud variety of Eureka lemon with excellent fruiting traits, but severe winter defoliation affects the following year’s yield, and the response mechanism of lemon defoliation is currently unknown. Two lemon cultivars (’Allen Eureka’ and ’Yunning No. 1’) with different defoliation traits were used as materials to investigate the molecular regulatory mechanisms of different leaf abscission periods in lemons. The petiole abscission zone was collected at three different defoliation stages, namely, the predefoliation stage (k15), the middefoliation stage (k30), and the postdefoliation stage (k45). Transcriptome sequencing was performed to analyze the gene expression differences between these two cultivars. A total of 1141, 2695, and 1433 differentially expressed genes (DEGs) were obtained in k15, k30, and k45, respectively, and the number of DEGs in k30 was the largest. GO analysis revealed that the DEGs between the two cultivars were mainly enriched in processes related to hydrolase activity, chitinase activity, oxidoreductase activity, and transcription regulator activity in the defoliation stages. KEGG analysis showed that the DEGs were concentrated in k30, which involved plant hormone signal transduction, phenylpropanoid biosynthesis, and biosynthesis of amino acids. The expression trends of some DEGs suggested their roles in regulating defoliation in Lemon. Seven genes were obtained by WGCNA, including sorbitol dehydrogenase (CL9G068822012_alt, CL9G068820012_alt, CL9G068818012_alt), abscisic acid 8’-hydroxylase (CL8G064053012_alt, CL8G064054012_alt), and asparagine synthetase (CL8G065162012_alt, CL8G065151012_alt), suggesting that these genes may be involved in the regulation of lemon leaf abscission.</div

Expression characteristics of differentially expressed genes of the plant hormone signal transduction pathway in ’Allen Eureka’ and ’Yunning No.

1’ lemons at each defoliation period. (The horizontal coordinates of the graphs in the heatmap are the sample names, and the vertical coordinates are the values of the differentially expressed genes after FPKM normalization; the redder the color is, the higher the expression, and the bluer the color is, the lower the expression).</p

Gene clustering tree and module cuts (merging gene modules with similar expression patterns; Different colors represent different modules, the number of genes assigned in a module is clustered according to their expression in a correlation, and genes with higher clusters are assigned to a module).

Gene clustering tree and module cuts (merging gene modules with similar expression patterns; Different colors represent different modules, the number of genes assigned in a module is clustered according to their expression in a correlation, and genes with higher clusters are assigned to a module).</p

Validation of the expression levels of four differentially expressed genes.

Validation of the expression levels of four differentially expressed genes.</p