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The effect of the microstructure of siliconized graphite on tribological properties is investigated by using a high-temperature and high-pressure water-lubricated tribometer on a self-mated ring-on-ring configuration under an applied load of 500–1500 N with a spindle speed of 100–5000 rpm in both 90 °C (5 MPa) and 25 °C (1 MPa) water environments, respectively. The Stribeck curves measurement and continuous wear tests are performed and analyzed in both water environments. The wear behaviors of the graphite, SiC, and free-silicon phases in siliconized graphite are demonstrated to explore the wear mechanism. The larger wear depths of a low-worn surface roughness on the three phases contribute to the boundary lubrication. The shallower wear depths are observed on the SiC and Si phases under the mixed lubrication, corresponding to partial contact wear of surface asperities. The wavy surface of the SiC phase and uniform flow-oriented striae of the Si phase are attributed to hydrodynamic lubrication, caused by full water film scouring the worn surface. Finally, an integrated evaluation method of G duty parameters is successfully used to identify the lubrication regimes of siliconized graphite from the boundary, mixed, to hydrodynamic lubrications for a water-lubricated thrust bearing application in the main coolant pump of a nuclear power plant. [ABSTRACT FROM AUTHOR]

Simple Summary: Heat stress (HS) constantly happens to dry lot feeding sheep during the summer, inevitably causing substantial losses to animal production due to its unfavorable effects on health, welfare and production performance. In the current study, HS played disadvantageous roles in growth performance, physiological indices, antioxidative capacity, immunomodulation, ruminal fermentation and microbial composition. Dietary supplementation with folic acid and taurine can effectively ameliorate adverse effects of HS by improving the proportion of beneficial bacteria such as Quinella and Succinivibrio and decreasing the abundance of harmful bacteria such as Asteroleplasma. This study provides a practical approach for the application of folic acid and taurine in HS-challenged sheep. The aim of this study was to investigate if the supplementation of folic acid and taurine can relieve the adverse effects of different levels of heat stress (HS) on growth performance, physiological indices, antioxidative capacity, immunity, rumen fermentation and microbiota. A total of 24 Dorper × Hu crossbred lambs (27.51 ± 0.96 kg) were divided into four groups: control group (C, 25 °C), moderate HS group (MHS, 35 °C), severe HS group (SHS, 40 °C), and the treatment group, under severe HS (RHS, 40 °C, 4 and 40 mg/kg BW/d coated folic acid and taurine, respectively). Results showed that, compared with Group C, HS significantly decreased the ADG of lambs (p < 0.05), and the ADG in the RHS group was markedly higher than in the MHS and SHS group (p < 0.05). HS had significant detrimental effects on physiological indices, antioxidative indices and immune status on the 4th day (p < 0.05). The physiological indices, such as RR and ST, increased significantly (p < 0.05) with the HS level and were significantly decreased in the RHS group, compared to the SHS group (p < 0.05). HS induced the significant increase of MDA, TNF-α, and IL-β, and the decrease of T-AOC, SOD, GPx, IL-10, IL-13, IgA, IgG, and IgM (p < 0.05). However, there was a significant improvement in these indices after the supplementation of folic acid and taurine under HS. Moreover, there were a significant increase in Quinella and Succinivibrio, and an evident decrease of the genera Rikenellaceae_RC9_gut_group and Asteroleplasma under HS (p < 0.05). The LEfSe analysis showed that the genera Butyrivibrio, Eubacterium_ventriosum_group, and f_Bifidobacteriaceae were enriched in the MHS, SHS and RHS groups, respectively. Correlated analysis indicated that the genus Rikenellaceae_RC9_gut_group was positively associated with MDA, while it was negatively involved in IL-10, IgA, IgM, and SOD (p < 0.05); The genus Anaeroplasma was positively associated with the propionate and valerate, while the genus Succinivibrio was negatively involved in TNF-α (p < 0.05). In conclusion, folic acid and taurine may alleviate the adverse effects of HS on antioxidant capacity, immunomodulation, and rumen fermentation of lambs by inducing changes in the microbiome that improve animal growth performance. [ABSTRACT FROM AUTHOR]

The superhydrophobic surfaces with three kinds of nanopillars on polypropylene (PP) substrates are fabricated by a plasma nanotexturing technique comprising oxygen‐plasma treatment (OPT) followed by fluorocarbon polymer deposition (FPD). The diameters of nanopillars and spacing distances between nanopillars are tuned under the different OPT and FPD duration times. The wettability and contact electrification on the surfaces are analyzed under the water droplet impact by changing the impacting droplet number, Weber number, and salt concentration. The dense or wide nanopillars favor high contact charge on the surfaces with nanopillars, arousing the damage of the superhydrophobicity with low adhesion. The low contact charge impacting the droplets with high salt concentration has a weakened effect on the superhydrophobicity of the surfaces with nanopillars. [ABSTRACT FROM AUTHOR]

The carbon fiber‐reinforced polyetheretherketone (CF/PEEK) composite coatings with two types of short CFs, that is, 300‐ and 600‐mesh, each in the contents of 10 and 30 wt% are deposited in comparison with the pure PEEK coatings by using a flame spraying method, respectively. The 300‐mesh CFs with intact morphology and the 600‐mesh CFs preserving fractured shape and higher graphitization degree are selected as the reinforced fillers in the CF/PEEK composite coatings. The flame‐sprayed CF/PEEK composite coatings show the increased porosity with the higher CF contents. The adding of CFs in the flame‐sprayed CF/PEEK composite coatings limits the thermal degradation of PEEK and restrains the PEEK crystallization showing low crystallinity degree and small crystallite size. The composite coatings in 10 wt% CF content exhibit the optimized nanoindentation behavior and tribological property. The 300‐mesh CFs with large length and intact morphology in flame‐sprayed CF/PEEK composite coatings lead to the increased surface hardness by 1.31 times over that of the pure PEEK coatings. The 600‐mesh CFs with higher graphitization degree contribute to better tribological property of flame‐sprayed CF/PEEK composite coatings with an order of magnitude lower specific wear rate. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate if the supplementation of folic acid and taurine can relieve the adverse effects of different levels of heat stress (HS) on growth performance, physiological indices, antioxidative capacity, immunity, rumen fermentation and microbiota. A total of 24 Dorper × Hu crossbred lambs (27.51 ± 0.96 kg) were divided into four groups: control group (C, 25 °C), moderate HS group (MHS, 35 °C), severe HS group (SHS, 40 °C), and the treatment group, under severe HS (RHS, 40 °C, 4 and 40 mg/kg BW/d coated folic acid and taurine, respectively). Results showed that, compared with Group C, HS significantly decreased the ADG of lambs ( p < 0.05), and the ADG in the RHS group was markedly higher than in the MHS and SHS group ( p < 0.05). HS had significant detrimental effects on physiological indices, antioxidative indices and immune status on the 4th day ( p < 0.05). The physiological indices, such as RR and ST, increased significantly ( p < 0.05) with the HS level and were significantly decreased in the RHS group, compared to the SHS group ( p < 0.05). HS induced the significant increase of MDA, TNF-α, and IL-β, and the decrease of T-AOC, SOD, GPx, IL-10, IL-13, IgA, IgG, and IgM ( p < 0.05). However, there was a significant improvement in these indices after the supplementation of folic acid and taurine under HS. Moreover, there were a significant increase in Quinella and Succinivibrio , and an evident decrease of the genera Rikenellaceae&#95;RC9&#95;gut&#95;group and Asteroleplasma under HS ( p < 0.05). The LEfSe analysis showed that the genera Butyrivibrio , Eubacterium&#95;ventriosum&#95;group , and f&#95;Bifidobacteriaceae were enriched in the MHS, SHS and RHS groups, respectively. Correlated analysis indicated that the genus Rikenellaceae&#95;RC9&#95;gut&#95;group was positively associated with MDA, while it was negatively involved in IL-10, IgA, IgM, and SOD ( p < 0.05); The genus Anaeroplasma was positively associated with the propionate and valerate, while the genus Succinivibrio was negatively involved in TNF-α ( p < 0.05). In conclusion, folic acid and taurine may alleviate the adverse effects of HS on antioxidant capacity, immunomodulation, and rumen fermentation of lambs by inducing changes in the microbiome that improve animal growth performance.

Recently, the relationship between the goat host and its gastrointestinal microbiome has emerged as a hallmark of host-microbiota symbiosis, which was indispensable for the proper physiological function that convert the plant biomass to livestock products. However, little integrative information about the establishment of gastrointestinal microflora in goats exists. Herein, we characterized the colonizing process of the bacterial community in the digesta and mucosa of the rumen, cecum, and colon of the cashmere goat from birth to adulthood to compare its spatiotemporal difference via 16S rRNA gene sequencing. A total of 1,003 genera belonging to 43 phyla were identified. Principal coordinate analysis unveiled the similarity of microbial community between or within each age group increased and gradually developed toward mature whatever in digesta or mucosa. In the rumen, the composition of the bacterial community in digesta differed significantly from in mucosa across age groups; whereas in the hindgut, there was a high similarity of bacterial composition between the in digesta and mucosa in each age group before weaning, while the bacterial community structure differed markedly between these two types of samples after weaning. Taxonomic analysis indicated that 25 and 21 core genera coexisted in digesta and mucosa of the rumen and hindgut, respectively; but their abundances differed considerably by GIT region and/or age. In digesta, as goats aged, a lower abundance of Bacillus was observed with higher abundances of Prevotella 1 and Rikenellaceae RC9 in the rumen; while in the hindgut, the genera Escherichia-Shigella , Variovorax , and Stenotrophomonas decreased and Ruminococcaceae UCG-005 , Ruminococcaceae UCG-010 , and Alistipes increased with age increased. In mucosa, the rumen showed microbial dynamics with increases of Butyrivibrio 2 and Prevotellaceae UCG-001 and decreases of unclassified&#95; f&#95;Pasteurellaceae ; while the genera Treponema 2 and Ruminococcaceae UCG-010 increased and Escherichia-Shigella decreased in the hindgut as goats aged. These results shed light on the colonization process of microbiota in the rumen and hindgut, which mainly include the initial, transit, and mature phases. Furthermore, there is a significant difference in the microbial composition between in digesta and mucosa, and both these exhibit a considerable spatiotemporal specificity., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Li, Yin, Lei, Wang, Yang, Zhang and Chen.)