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In this work, high temperature oxidation tests, high temperature hot salt corrosion tests and high temperature hot salt-water vapor synergistic corrosion tests were designed and used to systematically investigate the high temperature corrosion behavior and mechanism of Ti2AlNb alloy in simulated marine environments. The phase structure characteristics, microscopic corrosion morphology and corrosion product composition of Ti2AlNb alloy were comprehensively characterized by XRD, SEM and EDS microscale analysis methods. Results showed that after 400 h of oxidation at 650 ℃, the oxidation weight gain of Ti2AlNb alloy was only 0.507 mg/cm2, and a uniform dense oxide layer with approximately 3 μm thickness was generated in situ on the surface. After 400 h of hot salt corrosion at 650 ℃, the weight gain of Ti2AlNb alloy was as high as 4.049 mg/cm2, and the surface oxide layer was brownish yellow with a thickness of up to 150 μm. Meanwhile, the Cl2 generated by the mixed salt eutectic reaction during the hot salt test served as a catalytic carrier to accelerate the corrosion degradation of the alloy, and the induced formation of gaseous chlorides and corrosion products(such as NaNbO3 and Na2TiO3) ultimately led to severe cracking and peeling of the oxide layer, resulting in severe overall failure and degradation of the alloy. After 400 h of synergistic corrosion by 650 ℃ hot salt water vapor, the corrosion damage of Ti2AlNb alloy was further intensified. The water vapor environment led to the corrosion degradation of its surface oxide layer and the formation of HCl, and HCl infiltration further accelerated the degradation of the substrate alloy. In addition, the internal diffusion of mixed salts and the Cl2 produced by their eutectic reaction reacted with water to form HCl again, and HCl further accelerated the corrosion degradation process of Ti2AlNb, which further caused the accumulation and detachment of a large number of loose corrosion products. As a result, the strong coupling effect of high-temperature hot salt water vapor seriously threatened the service life of Ti2AlNb alloy.

Sporocarps of macrofungi support other diverse fungal species that are termed fungicolous fungi. However, the external environmental factors that affect the diversity and composition of fungicolous fungal communities remains largely unknown. In this study, the diversities, composition, and trophic modes of fungicolous fungal communities residing in host macrofungi from diverse habitats in the Qinling Mountains were analyzed. Additionally, the number of carbohydrate-active enzymes (CAZymes) encoded by saprophytic, pathogenic, and symbiotic fungi was also quantified and compared. The results revealed that the diversity and composition of fungicolous fungal communities varied with months of collection and the habitats of host fungi, and saprophytic fungi were more abundant on wood than on the ground. Meanwhile, it was also found that saprophytic fungi possessed higher abundances of cell-wall-degrading enzymes than pathogenic or symbiotic fungi. Based on the above findings, it was hypothesized that the greater abundance of saprophytic fungi on wood compared to the ground may be due to their possession of a more diverse array of enzymes capable of degrading wood cell walls, thereby allowing for more efficient nutrient acquisition from decaying wood. [ABSTRACT FROM AUTHOR]

To prolong the service life and structural stability of CoCrNiAlY–yttria stabilized zirconia–LaMgAl11O19 (LaMA) dual ceramic coating during high temperature exposure, an AlY plating layer was deposited on top LaMA. Results revealed that this coating without AlY plating layer showed a rapid mass increase from 6.62 mg/cm2 at 20 h to 10.63 mg/cm2 at 80 h, but also suffered from a fast TGO growth and severe elemental diffusion, resulting in an exacerbating interface fracture of the coating. However, AlY plating layer was first oxidized, and Y2O3 induced the formation of a dense α‐Al2O3 reaction layer on the top LaMA layer, which greatly prevented the internal penetration of O2. This coating with AlY plating layer showed a relatively stable structure, a very slow TGO growth, and a slight mass increase trend from 8.19 mg/cm2 at 20 h to 8.73 mg/cm2 at 80 h. Potential oxidation damage mechanisms of the coatings with or without AlY plating layer were comprehensively clarified. [ABSTRACT FROM AUTHOR]

Scutellaria baicalensis Georgi is an annual herb from the Scutellaria genus that has been extensively used as a traditional medicine for over 2000 years in China. Baicalin and other flavonoids have been identified as the principal bioactive ingredients. The biosynthetic pathway of baicalin in S. baicalensis has been elucidated; however, the specific functions of R2R3-MYB TF, which regulates baicalin synthesis, has not been well characterized in S. baicalensis to date. Here, a S20 R2R3-MYB TF (SbMYB12), which encodes 263 amino acids with a length of 792 bp, was expressed in all tested tissues (mainly in leaves) and responded to exogenous hormone methyl jasmonate (MeJA) treatment. The overexpression of SbMYB12 significantly promoted the accumulation of flavonoids such as baicalin and wogonoside in S. baicalensis hairy roots. Furthermore, biochemical experiments revealed that SbMYB12 is a nuclear-localized transcription activator that binds to the SbCCL7-4, SbCHI-2, and SbF6H-1 promoters to activate their expression. These results illustrate that SbMYB12 positively regulates the generation of baicalin and wogonoside. In summary, this work revealed a novel S20 R2R3-MYB regulator and enhances our understanding of the transcriptional and regulatory mechanisms of baicalin biosynthesis, as well as sheds new light on metabolic engineering in S. baicalensis. [ABSTRACT FROM AUTHOR]

Hepatic Stem/progenitor cells (HSPCs) have gained a large amount of interest for treating acute liver disease. However, the isolation and identification of HSPCs are unclear due to the lack of cell-specific surface markers. To isolate adult HSPCs, we used cell surface-marking antibodies, including CD49f and Sca-1. Two subsets of putative HSPCs, Lin−CD45−Sca-1−CD49f+ (CD49f+) and Lin−CD45−Sca-1+CD49f− (Sca-1+) cells, were isolated from adult mice liver by flow cytometry. Robust proliferative activity and clonogenic activity were found in both CD49f+ and Sca-1+ cells through colony-forming tests and cell cycle analyses. Immunofluorescence staining revealed that CD49f+ cells expressed ALB and CK-19 while Sca-1+ cells expressed only ALB, indicating that CD49f+ cells were bipotential and capable of differentiating into hepatocyte and cholangiocyte. Consequently, PAS stain showed that differentiated CD49f+ and Sca-1+ cells synthesised glycogen, indicating they could differentiate into functional hepatocytes. mRNA expression profile indicated that both CD49f+ and Sca-1+ cells showed differential expression of genes that are associated with liver progenitor function such as Sox9 and EpCam. Moreover, two subsets of putative HSPCs were activated by DDC and we found that their abundance and proliferation increased with age. In summary, we hypothesized that CD49f+ cells were a type of potential HSPCs and may be utilised for clinical stem cell therapy. [ABSTRACT FROM AUTHOR]

Hypericum perforatum is among the most commonly used herbal remedies and supplements. The aerial plant parts are often used to treat depression. Due to the lack of genomic information of H. perforatum, the gene networks regulating secondary metabolite synthesis remain unclear. Here, we present a high‐quality genome for H. perforatum with a 2.3‐Mb scaffold N50. The draft assembly covers 91.9% of the predicted genome and represents the fourth sequenced genus in the order Malpighiales. Comparing this sequence with model or related species revealed that Populus trichocarpa and Hevea brasiliensis could be grouped into one branch, while H. perforatum and Linum usitatissimum are grouped in another branch. Combined with transcriptome data, 40 key genes related to melatonin, hyperforin, and hypericin synthesis were screened and analyzed. Five N‐acetylserotonin O‐methyltransferases (HpASMT1‐HpASMT5) were cloned and functionally characterized. Purified HpASMT3 protein converted N‐acetylserotonin into melatonin with a Vmax of about 1.35 pkat/mg protein. HpASMT1 and HpASMT3 overexpression in Arabidopsis mutants caused 1.5‐2‐fold higher melatonin content than in mutant and wild‐type plants. The endogenous reactive oxygen species (ROS) in transgenic plants was significantly lower than ROS in mutant and wild‐type plants, suggesting higher drought tolerance. The obtained genomic data offer new resources for further study on the evolution of Hypericaceae family, but also provide a basis for further study of melatonin biosynthetic pathways in other plants. [ABSTRACT FROM AUTHOR]

To understand the enhanced protection mechanism of CoCrNiAlY–YSZ–LaMgAl11O19 double-layer ceramic coating with aluminum plating, a finite element simulation method was used to simulate the distribution of thermal stress in the coating in all directions. The results show that in the air exposure of the un-aluminized coating, high temperature causes a large radial thermal stress on the surface of the LaMgAl11O19 (LMA) layer, and it increases with the increase in temperature, which is the main reason for the initiation of axial cracks. After arc aluminum plating, the aluminum plating layer effectively inhibited the volume shrinkage of the coating through good adhesion to the coating and internal diffusion; the thermal stress of the coating was considerably reduced; and the CoCrNiAlY–YSZ–LMA coating had an effective enhancement and protection effect. However, there was still a certain amount of shear thermal stress inside the LMA layer, the top of the crack, and the bottom of the crack. This thermal stress caused the initiation of radial microcracks in the LMA layer, which also becomes a risk point for the failure of the aluminum coating. [ABSTRACT FROM AUTHOR]

This study investigated the potential effect of vacuum annealing on the microstructure and hot salt corrosion behavior of CoNiCrAlY/YSZ/LaMgAl11O19 (LMA) double-ceramic coatings. A hot-salt corrosion test revealed that sprayed coatings exhibited an unsatisfactory anti-corrosion performance, and the LMA layer underwent severe fracture and corrosion degradation. Vacuum annealing induced a prominent recrystallization of the amorphous phase in LMA layer, triggering severe volume shrinkage and microcrack initiation. The recrystallization and volume shrinkage of the LMA layer were aggravated by an increase in the annealing temperature. The annealed coating with a higher fraction of the LaMA phase showed superior resistance to hot-salt corrosion. However, the salt mixture diffused simultaneously along the microcracks and eventually eroded into the YSZ layer. These results confirmed that vacuum annealing significantly enhanced the hot-salt corrosion resistance of the LMA layer. However, it deteriorated the barrier effect of the salt mixture through microcrack formation. [ABSTRACT FROM AUTHOR]

To investigate the potential roles of stress-activated protein kinase (SAPK) gene family members in Dendrobium officinale , we employed multiple bioinformatics methods to identify the members of this family. The physicochemical properties, chromosomal localization, phylogenetic relationship, gene structure, and cis -acting elements of each D . officinale SAPK (DoSAPK) member were analyzed. In addition, their expression profiles in different tissues and under the low-temperature or salt stress treatment were determined by real-time fluorescence quantitative PCR. The results showed that D . officinale carried eight DoSAPK family members, which belonged to three groups (groups Ⅰ, Ⅱ, and Ⅲ). These genes were located on seven chromosomes, and there were two pairs of genes with replication. The DoSAPK members within the same group had similar gene structures, conserved motifs, and secondary structures. The cis -acting elements in the promoter regions of DoSAPK genes included abundant hormone and stress response elements. DoSAPK family members presented tissue-specific expression in D . officinale . Furthermore, they were differentially expressed under the low-temperature or salt stress treatment, which suggested that they might be involved in the responses to low-temperature and salt stress. Intriguingly, DoSAPK1 might play a role in the abiotic stress responses. The results laid a foundation for in-depth study of the members and roles of the DoSAPK gene family.