Search

Piping systems in thermal power plants are generally subjected to creep–fatigue loading caused by internal pressure, bending moment, and torsional moment in a high-temperature environment. These loadings cause Type IV cracks to form in the heat-affected zone in the weldment of the piping. In this study, we attempt to predict the creep–fatigue Type IV crack initiation life using a wireless micro-electromechanical system-type gyro sensor to understand the damage progress in plant components for the establishment of digital twin technology, which has recently attracted attention. The strategy for developing the system is as follows: i) remotely and sequentially import signals from a sensor attached to the actual component to a personal computer and ii) identify mechanical conditions such as bending and torsional moments in the piping component even in a high-temperature environment. This study first shows how to identify both moments in a piping system based on the rotation angles (deflection and torsion angles) measured using a gyro sensor. Next, a creep–fatigue life diagram is constructed based on the equivalent bending moment, which can combine the two independent parameters of bending and torsional moments into a single parameter. Finally, creep–fatigue tests were performed on a P91 steel piping weldment specimen using the high-temperature bending–torsional creep–fatigue testing machine developed by our group, and it was shown that the equivalent bending moment identified from the gyro sensor attached to the piping specimen can predict the Type IV creep–fatigue crack initiation life at the weldment.

We focused on the possibility that pathogenic microorganisms might produce immune suppressors to evade the action of immune cells. Based on this possibility, we have recently developed new co-culture method of pathogenic actinomyces and immune cells, however, the interaction mechanism between pathogens and cells was still unclear. In this report, co-culturing pathogenic fungi and immune cells were investigated. Pathogenic fungus Aspergillus terreus IFM 65899 and THP-1 cells were co-cultured and isolated a co-culture specific compound, butyrolactone Ia (1). 1 inhibits the production of nitric oxide by RAW264 cells and exhibits regulatory effects on autophagy, suggesting 1 plays a defensive role in the response of A. terreus IFM 65899 to immune cells. Furthermore, dialysis experiments and micrographs indicated that "physical interaction" between A. terreus IFM 65899 and THP-1 cells may be required for the production of 1. This is the first report of co-culture method of fungi with immune cells and its interaction mechanism., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

The activation of secondary metabolism plays a pivotal role in the discovery of novel natural products. We recently developed a coculture method involving actinomycetes and mouse macrophage-like cells to stimulate the production of bioactive compounds. A black koji mold, Aspergillus luchuensis IFM 61405, markedly enhanced the production of (3 S ,8 R )-8-hydroxy-3-carboxy-2-methylenenonanoic acid ( 1a ), (3 S ,8 S )-8-hydroxy-3-carboxy-2-methylenenonanoic acid ( 1b ), and (3 S )-9-hydroxy-3-carboxy-2-methylenenonanoic acid ( 2 ) when coincubated with J774.1 mouse macrophage cells. The production of 1 and 2 increased by at least 3.5-fold and 2.7-fold, respectively, compared to monoculture after 7 days. A mechanistic investigation revealed that a protease from strain IFM 61405 plays a key role in enhancing the production of 1 and 2 . This enhancement was not replicated in A. niger IFM 59706, a nonkoji mold, despite the presence of biosynthetic genes for 1 and 2 in A. niger IFM 59706. Furthermore, the addition of protease inhibitors suppressed the production of 1 and 2 , suggesting that proteins secreted from animal cells, likely degraded by proteases secreted by strain IFM 61405, serve as precursors for 1 and 2 . The results show that the strategy of coculturing koji mold with animal cells has the potential to enhance the production of natural products., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Secondary metabolites produced by actinomycete strains undoubtedly have great potential for use in applied research areas such as drug discovery. However, it is becoming difficult to obtain novel compounds because of repeated isolation around the world. Therefore, a new strategy for discovering novel secondary metabolites is needed. Many researchers believe that actinomycetes have as yet unanalyzed secondary metabolic activities, and the associated undiscovered secondary metabolite biosynthesis genes are called "silent" genes. This review outlines several approaches to further activate the metabolic potential of actinomycetes., (Copyright © 2024, Saito and Arai.)

When cultured anaerobically, Enterocloster sp. RD014215 was found to produce 1. Using nuclear magnetic resonance and mass spectroscopy, the planar structure of 1 was determined to be 3-hydroxy-3-(2-oxopropyl)indolin-2-one. The chirality of 1 was implied as S by comparing the optical rotation value of 1 with literature reports of the synthesized compounds. To our knowledge, this work represents the first discovery of the metabolite produced by Enterocloster strain. 1 exhibited inhibition of nitric oxide (NO) production, demonstrating a 50% inhibitory activity (IC50) of 34 µm for NO production by murine macrophage cells subjected to lipopolysaccharide stimulation., (© The Author(s) 2023. Published by Oxford University Press on behalf of Japan Society for Bioscience, Biotechnology, and Agrochemistry.)

We screened a library of microbial extracts and compounds library using our constructed assay cells and found pulicatins F (1) and G (2), and cyclopiazonic acid (CPA) (3) as Notch activators. Pulicatin F (1) and (±)-pulicatin G were synthesized and their activities were evaluated. Notch activation of CPA (3) was investigated using Western blot and RT-PCR. CPA (3) increased protein level of HES1 and mRNA expression of HES1. Also, the expression of FMS-like tyrosine kinase 3 (FLT3), which was known to inhibit apoptosis, was also inhibited by CPA (3) addition. The Notch activation by CPA (3) and cytotoxicity against HL-60 were clearly canceled by addition of FK506, which is an inhibitor of calcineurin (CaN). In addition, it was revealed that CPA (3) induced apoptosis in HL-60 cells., (© 2023. The Author(s), under exclusive licence to the Japan Antibiotics Research Association.)