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The CD44 gene encodes a cell-surface glycoprotein that participates in a variety of biological processes such as cell interactions, adhesion, hematopoiesis, and tumor metastasis. We compared the transcriptome in bovine mammary epithelial cells (bMEC) of Chinese Holstein dairy cows producing milk of high and low fat contents. Our results suggest that CD44 might be a candidate gene affecting milk fat synthesis. In the present study, the overexpression of the CD44 gene increased the contents of intracellular triglycerides (TG) and cholesterol (CHOL), whereas knockdown of the CD44 gene decreased bMEC CHOL and TG contents. Gas chromatography analysis of fatty acid composition showed that the contents of α-linolenic acid, palmitic acid, and cis-8,11,14-eicosatrienoic acid were altered due to changes in the level of expression of the CD44 gene. Additionally, elaidic acid, palmitoleic acid, tridecanoic acid, and oleic acid were markedly reduced in the CD44 gene overexpression group compared with the control group. On the contrary, cis-5,8,11,14-eicosatetraenoic acid and stearic acid were markedly increased in the CD44 knockdown group compared with the control group. And RT 2 Profiler PCR array (Qiagen, CLAB24070A Frankfurt, Germany) further suggested that overexpression or knockdown of the CD44 gene altered expression levels of functional genes associated with lipid metabolism. The present data indicate that CD44 plays a key regulatory role in lipid metabolism in bMEC.

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Hydrothermal carbonization conditions can affect the combustion and kinetics of wheat straw hydrochar pellets. Temperature and time are the key influencing factors of the hydrothermal carbonization reaction. Hence, exploring the effects of hydrothermal carbonization temperature and time on the combustion and kinetics is of great significance, which can also summarize the conditions for efficiency improvement. Herein, the chemical characteristics and surface microstructures of hydrochar and the combustion characteristics, ash fusibility, slagging characteristics, and kinetics of hydrochar pellets were analyzed. The results indicated that the carbon microspheres appeared on the surface of hydrochar from 220 °C for 10 min. The combustion characteristics under 180 and 220 °C were better than those under 260 °C. The slagging tendency of hydrochar pellets was lower than that of wheat straw pellets. It belonged to moderate melting ash and a low slagging rate when HTC conditions equaled or exceeded 220 °C for 10 min. Activation energies were moderate under 220 °C for 10, 20, and 30 min. Hydrochar pellets had high fuel efficiency under 220 °C for 10, 20, and 30 min. The comprehensive combustibility index was positively correlated with hemicellulose and negatively correlated with lignin. The positive correlation was between the cellulose content and the activation energy of the first zone.

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