CoRe bimetallic catalysts with low loading were designed for hydrodeoxygenation of levulinic acid to γvalerolactone. Results show that the 1 wt % Co 0.5 Re 0.5 /TiO 2 catalyst achieved the highest yield of γ-valerolactone (>99%) at 220 °C, 3 h, a 1,4-dioxane solvent and Co/levulinic acid molar ratio of 1:1760, with a turnover frequency (TOF) of 1328 h −1 . The catalyst can be reused four times with only slight activity loss. The catalyst was characterized with various physicochemical measurements, and its adsorption styles with H 2 and levulinic acid were calculated by density functional theory. The results reveal that four main factors are related to its excellent catalytic performance. First, the Re oxides synergize with Co by spillover of the dissociated H atoms, which increases the apparent dispersion of Co and promotes the reaction. Second, the low loading of 1 wt % allowed the metal nanoparticles to be well dispersed with a very fine size of ca. 1.24 nm, which may expose more active sites to the substrate and result in a higher catalytic efficiency. Third, CoRe formed an amorphous alloy with the formula Co-ReO 1.6 , which showed a synergistic effect during the reaction. Finally, the TiO 2 support was nonporous and hydrophilic, which would be beneficial for the mass diffusion of the reaction components to be adsorbed/desorbed onto the vicinity of the metallic active sites and lead to a high TOF in the hydrodeoxygenation process.

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Trace elements are essential for the proper functioning of proteins, enzymes, and transcriptional factors. However, toxic metals will compete with essential trace elements, and damage enzymatic activities and various physiological functions. We aimed to investigate the status of serum essential trace elements and toxic metals in Chinese diabetic retinopathy (DR) patients, and to analyze their associations. This retrospective study included 33 normal subjects (normal group), 44 type 2 diabetes mellitus (T2D) patients with DR (DR group), and 58 T2D patients without DR (diabetes mellitus [DM] group). Serum levels of zinc (Zn), manganese (Mn), cadmium (Cd), and cesium (Cs), were measured for all participants using inductively coupled plasma-mass spectrometry. The serum concentrations of Mn (0.0226 μg/L) and Zn (98.162 μg/L) were significantly lower in DR group, compared with both the DM group and normal group (P < 0.05). In contrast, the serum levels of Cs (0.0354 μg/L) and Cd (0.0149 μg/L) were significantly higher in DR group, compared with the normal group (Cs: z = 3.136, P = .002; Cd: z = 3.766, P < .0001). Similarly, the serum Cs level in the DM group was 0.0323 μg/L, which was significantly higher than that in the normal group (0.0167 μg/L, z = 2.692, P = .007). Moreover, the area under the receiver-operating characteristic curve values of Mn (0.753 [95% confidence interval, CI 0.635–0.872, P = .002]), and Cd (0.797 [95% CI 0.643–0.952, P = .003]) were significantly greater than those of Zn and Cs, for DR identification. Our results suggest that deficient essential trace elements and accumulated toxic metals were highly associated with the presence of DR.