Purple Sweet Potato Polysaccharide Exerting an Anti-inflammatory Effect via a TLR-Mediated Pathway by Regulating Polarization and Inhibiting the Inflammasome Activation.

Purple sweet potato polysaccharide (PSPP-1) is a novel glucan; this study aimed to examine the anti-inflammatory effect of PSPP-1 and elucidate its potential mechanisms. Lipopolysaccharide (LPS)-induced RAW264.7 was used as the model of inflammation, cell viability, and levels of nitric oxide (NO), reactive oxygen species (ROS), and calcium ion (Ca2+) were analyzed. ELISA and qPCR were used to assess the productions and mRNA expression of cytokines, and Western blotting was used to assess protein expressions in the TLR-mediated pathway, macrophage polarization, and inflammasome activation. The results demonstrated PSPP-1 inhibited cell proliferation and markedly decreased NO, ROS, and Ca2+ levels. Moreover, PSPP-1 suppressed the secretions and mRNA expressions of pro-inflammatory cytokines and increased those of anti-inflammatory cytokines. Furthermore, PSPP-1 could exert anti-inflammatory effects through different pathways mediated by both TLR2 and TLR4, which modulated the expressions of essential proteins in the myeloid differentiation factor 88 (MyD88)-dependent and toll/IL-1 receptor domain-containing adaptor-inducing interferon-ß (TRIF)-dependent signaling pathways. PSPP-1 even regulated the polarization of M1/M2 macrophages and inhibited the nucleotide oligomerization domain-like receptor protein 3 (NLRP3) inflammasome activation. These findings indicate that PSPP-1 can suppress LPS-induced inflammation via multiple pathways and may be a potential agent for therapeutic inflammation-related pathophysiological processes and disorders.

Leveraging Deep Neural Networks for Estimating Vickers Hardness from Nanoindentation Hardness.

This research presents a comprehensive analysis of deep neural network models (DNNs) for the precise prediction of Vickers hardness (HV) in nitrided and carburized M50NiL steel samples, with hardness values spanning from 400 to 1000 HV. By conducting rigorous experimentation and obtaining corresponding nanoindentation data, we evaluated the performance of four distinct neural network architectures: Multilayer Perceptron (MLP), Convolutional Neural Network (CNN), Long Short-Term Memory network (LSTM), and Transformer. Our findings reveal that MLP and LSTM models excel in predictive accuracy and efficiency, with MLP showing exceptional iteration efficiency and predictive precision. The study validates models for broad application in various steel types and confirms nanoindentation as an effective direct measure for HV hardness in thin films and gradient-variable regions. This work contributes a validated and versatile approach to the hardness assessment of thin-film materials and those with intricate microstructures, enhancing material characterization and potential application in advanced material engineering.

Screening of Siderophore-Producing Bacteria and Their Effects on Promoting the Growth of Plants.

Iron deficiency is a major global agricultural problem. Siderophores can help organisms to uptake iron in form of siderophore-Fe3+ complexes and then in the cell cytosol, iron is reducted and released in ferrous form. This research aimed to obtain some efficient siderophore-producing bacterial strains and evaluate their plant growth-promoting effects in the iron-deficit environment. Two strains, Brucella sp. E7 and Pseudomonas brassicae W7, were isolated from rhizosphere soil. Both strains could produce maximum siderophores under the optimal conditions. Plant promoting experiment showed that many indicators of Vigna radiata seedling were all increased significantly by strain E7/W7 or the consortium of E7 + W7. Under no-iron and high iron stress, the inoculation treatment also showed growth promotion effects on both Vigna radiata and Lolium multiflorum. These results indicated that the potential ability of strain E7 and W7 in increasing agricultural production as a growth-promoting agent in iron-deficit soil.

Immune-Enhancing Effects of a Novel Glucan from Purple Sweet Potato Ipomoea batatas (L.) Lam on RAW264.7 Macrophage Cells via TLR2- and TLR4-Mediated Pathways.

PSPP-1 was obtained from purple sweet potato, and the effects of PSPP-1 on the immune modulation on macrophage cells were investigated for the first time. PSPP-1 promoted RAW264.7 proliferation and increased the total cell percentage in DNA synthesis and mitosis phases, and the cell morphology changed in volume and appearance. Additionally, the RAW264.7 immune functions of phagocytic activity and nitric oxide, reactive oxygen species, and cytokine production were improved by PSPP-1. The western blot experiment showed that PSPP-1 could activate toll-like receptor 2 and toll-like receptor 4-mediated pathways, and the expressions of proteins in MyD88-dependent, mitogen-activated protein kinase (MAPK)-signaling, NF-κB-signaling, AP-1 signaling, and TRIF-dependent pathways were improved markedly. Molecular docking and Biolayer Interferometry study further indicated that PSPP-1 could recognize and bind TLR2 and TLR4 by targeting the binding sites with a strong affinity. It suggested that PSPP-1 could enhance immunity via TLR2- and TLR4-mediated pathways, and it could be explored as an immunomodulatory agent.

Fabrication and Mechanical Properties of Cr2AlC MAX Phase Coatings on TiBw/Ti6Al4V Composite Prepared by HiPIMS.

The high-power impulse magnetron sputtering (HiPIMS) technique is widely used owing to the high degree of ionization and the ability to synthesize high-quality coatings with a dense structure and smooth morphology. However, limited efforts have been made in the deposition of MAX phase coatings through HiPIMS compared with direct current magnetron sputtering (DCMS), and tailoring of the coatings' properties by process parameters such as pulse width and frequency is lacking. In this study, the Cr2AlC MAX phase coatings are deposited through HiPIMS on network structured TiBw/Ti6Al4V composite. A comparative study was made to investigate the effect of average power by varying frequency (1.2-1.6 kHz) and pulse width (20-60 µµs) on the deposition rate, microstructure, crystal orientation, and current waveforms of Cr2AlC MAX phase coatings. X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to characterize the deposited coatings. The influence of pulse width was more profound than the frequency in increasing the average power of HiPIMS. The XRD results showed that ex situ annealing converted amorphous Cr-Al-C coatings into polycrystalline Cr2AlC MAX phase. It was noticed that the deposition rate, gas temperature, and roughness of Cr2AlC coatings depend on the average power, and the deposition rate increased from 16.5 to 56.3 nm/min. Moreover, the Cr2AlC MAX phase coatings produced by HiPIMS exhibits the improved hardness and modulus of 19.7 GPa and 286 GPa, with excellent fracture toughness and wear resistance because of dense and column-free morphology as the main characteristic.

Analysis of growth and lipid production characteristics of Chlorella vulgaris in artificially constructed consortia with symbiotic bacteria.

The aim was to study the effect of artificially constructed consortia of microalgae-bacterial symbionts on growth and lipid production by Chlorella vulgaris (C. vulgaris), as well as the inter-relationship between microalgae and bacterial in a photoautotrophic system. The results showed that compared to an axenic culture of C. vulgaris, H1 co-culture system (axenic C. vulgaris-Stenotrophomona smaltophilia) had the strongest effect on the C. vulgaris growth. The biomass, specific growth rate and maximum productivity of C. vulgaris were increased by 21.9, 20.4, and 18%, respectively. The bacteria in co-culture system had a significant effect on the accumulation of lipid and fatty acid components of C. vulgaris: the content of lipid was increased by 8.2-33.83%, and the components of the saturated fatty acids and oleic acids also had an obvious improvement. The results indicate that the microalgae-bacterial co-culture system can improve microalgal biomass and the quality of biodiesel.