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The Floberg–Jakobsson–Olsson cavitation theory is implemented using a mass-conservative algorithm to accurately predict the behavior of cavitation in flat surfaces enhanced with dimples. The multigrid method is used to accelerate the convergence speed. Comparison is made on different cavitation theories. The results reveal that the load-carrying capacity of dimple-enhanced surfaces is limited under the simulated conditions.

A mass-conservative algorithm that implements the Jakobsson–Floberg–Olsson cavitation theory is used to predict the performances of seal-like structures and thrust bearings with a dimpled surface texture. The results of a series of simulations for load-carrying capacity, film thickness, dimple depth, dimple density, cavitation pressure, leakage, and friction force are presented, and the relationship between these performance parameters is studied. It is shown that, under the conditions simulated, surface roughness can improve the load-carrying capacity, but its effect is limited.

Greater feed efficiency (FE) is critical in increasing profitability while reducing the environmental impact of pig production. Previous studies that identified swine FEassociated bacterial taxa were limited in either sampling sites or sequencing methods. This study characterized the microbiomes within the intestine of FE contrasting Duroc × (Landrace × Yorkshire) (DLY) pigs with a comprehensive representation of diverse sampling sites (ileum, cecum, and colon) and a metagenomic sequencing approach. A total of 226 pigs were ranked according to their FE between weaning to 140 day old, and six with extreme phenotypes were selected, three for each of the high and low groups. The results revealed that the cecum and colon had similar microbial taxonomic composition and function, and had higher capacity in polysaccharide metabolism than the ileum. We found in cecum that the high FE pigs had slightly higher richness and evenness in their micriobiota than the low FE pigs. We identified 12 phyla, 17 genera, and 39 species (e.g., Treponema porcinum, Treponema bryantii, and Firmicutes bacterium CAG:110) that were potentially associated with swine FE variation in cecum microbiota through LEfSe analysis. Species enriched in the cecum of the high FE pigs had a greater ability to utilize dietary polysaccharides and dietary protein according to the KEGG annotation. Analysis of antibiotic resistance based on the CARD database annotation indicated that the macB resistant gene might play an important role in shaping the microbial community in the cecum of pigs with contrasting FE. The bacteria from the genus Prevotella was highly enriched in the cecum of low FE pigs, which may impair the establishment of a more effective nutrient harvesting microbiota because of the interaction between Prevotella and other benefical microbes. These findings improved our understanding of the microbial compositions in the different gut locations of DLY pigs and identified many biomarkers associated with FE variation wich may be used to develop strategies to improve FE in pigs.

N-{4-[(2-Amino-6-methyl-4-oxo-3,4-dihydrothieno[2,3-d]pyrimidin-5-yl)sulfanyl]benzoyl}-L-glutamic acid (4) and nine nonclassical analogues 5–13 were synthesized as potential dual thymidylate synthase (TS) and dihydrofolate reductase (DHFR) inhibitors. The key intermediate in the synthesis was 2-amino-6-methylthieno[2,3-d]pyrimidin-4(3H)-one (16), which was converted to the 5-bromo-substituted compound 17 followed by an Ullmann reaction to afford 5–13. The classical analogue 4 was synthesized by coupling the benzoic acid derivative 19 with diethyl l-glutamate and saponification. Compound 4 is the most potent dual inhibitor of human TS (IC50 = 40 nM) and human DHFR (IC50 = 20 nM) known to date. The nonclassical analogues 5–13 were moderately potent against human TS with IC50 values ranging from 0.11 to 4.6 µM. The 4-nitrophenyl analogue 7 was the most potent compound in the nonclassical series, demonstrating potent dual inhibitory activities against human TS and DHFR. This study indicated that the 5-substituted 2-amino-4-oxo-6-methylthieno[2,3-d]pyrimidine scaffold is highly conducive to dual human TS-DHFR inhibitory activity.

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Low-molecular-weight poly-γ-glutamic acid (LMW-γ-PGA) has attracted much attention owing to its great potential in food, agriculture, medicine, and cosmetics. Current methods of LMW-γ-PGA production, including enzymatic hydrolysis, are associated with low operational stability. Here, an efficient method for stable biosynthesis of LMW-γ-PGA was conceived by overexpression of γ-PGA hydrolase in Bacillus amyloliquefaciens NB. To establish stable expression of γ-PGA hydrolase (PgdS) during fermentation, a novel plasmid pNX01 was constructed with a native replicon from endogenous plasmid p2Sip, showing a loss rate of 4% after 100 consecutive passages. Subsequently, this plasmid was applied in a screen of high activity PgdS hydrolase, leading to substantial improvements to γ-PGA titer with concomitant decrease in the molecular weight. Finally, a satisfactory yield of 17.62 ± 0.38 g/L LMW-γ-PGA with a weight-average molecular weight of 20−30 kDa was achieved by direct fermentation of Jerusalem artichoke tuber extract. Our study presents a potential method for commercial production of LMW-γ-PGA.

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