Atherosclerosis, accompanied by inflammation and metabolic disorders, is the primary cause of clinical cardiovascular death. In recent years, unhealthy lifestyles (e.g., sedentary lifestyles) have contributed to a worldwide epidemic of atherosclerosis. Exercise is a known treatment of atherosclerosis, but the precise mechanisms are still unknown. Here, we show that 12 weeks of regular exercise training on a treadmill significantly decreased lipid accumulation and foam cell formation in ApoE^−/− mice fed with a Western diet, which plays a critical role in the process of atherosclerosis. This was associated with an increase in β-hydroxybutyric acid (BHB) levels in the serum. We provide evidence that BHB treatment in vivo or in vitro increases the protein levels of cholesterol transporters, including ABCA1, ABCG1, and SR-BI, and is capable of reducing lipid accumulation. It also ameliorated autophagy in macrophages and atherosclerosis plaques, which play an important role in the step of cholesterol efflux. Altogether, an increase in serum BHB levels after regular exercise is an important mechanism of exercise inhibiting the development of atherosclerosis. This provides a novel treatment for atherosclerotic patients who are unable to undertake regular exercise for whatever reason. They will gain a benefit from receiving additional BHB.

The morphology and crystal structure of rhombohedral B₁₂As₂ thin films prepared by chemical vapor deposition on Si (1 0 0), Si (1 1 0) and Si (1 1 1) substrates were examined. For short depositions, 30 s at 1300 °C, the B₁₂As₂ nucleated in patterns that were unique to each substrate orientation, probably due to variations in the surface atomic structure and surface activation energy of the substrates. Small square domains, one-dimensional straight lines, and irregular lines were the representative morphologies on Si (1 0 0), Si (1 1 1) and Si (1 1 0), respectively. For long depositions, 30 min at 1300 °C, continuous thin films of B₁₂As₂ formed with distinct morphologies also depend on the orientation of the substrates. “Cross”, “wire” and “chain” morphologies were formed on the Si (1 0 0), Si (1 1 1) and Si (1 1 0) substrates, respectively. X-ray diffraction (XRD) showed that the B₁₂As₂ films had the following predominant oriented textures: B₁₂As₂ (1 1 0) on Si (1 0 0), B₁₂As₂ (1 0 1) on Si (1 1 1), and B₁₂As₂ (0 0 1) on Si (1 1 0). The in-plane orientations of the B₁₂As₂ films as determined by XRD pole figures is also reported.