Fecal metabonomics combined with 16S rDNA sequencing to analyze the changes of gut microbiota in rats fed with different protein source diets.

PURPOSE: When blended, animal and plant proteins can complement each other in terms of amino acid composition and release time. In this study, we investigated whether the blended protein diet has a better feeding effect than the single protein diet, and to reveal the differences in growth and intestinal microbiota composition caused by the blended protein diet. METHODS: Forty Sprague Dawley (SD) rats received diets with different protein sources, including casein (C), whey protein (WP), black soybean protein (BSP), and black soybean-whey blended protein (BS-WP), for eight weeks. To investigate the effects of blended protein supplement on gut microbiota and metabolites, we performed a high throughput 16S rDNA sequencing and fecal metabolomics profiling. In addition, we determined growth and serum biochemical indices, and conducted intestinal morphology analyses. RESULTS: Compared to those in the BSP and WP groups, the daily body weight gain and feed conversion efficiency increased in the BS-WP group. Serum biochemical indices indicated that the protein utilization efficiency of the WP and BS-WP groups was relatively high, and the BS-WP blended protein diet improved the protein adoption rate. The BS-WP blended protein diet also improved intestinal tissue morphology and promoted intestinal villi development compared to the single protein diets. Furthermore, dietary protein altered the composition of gut microbiota, the gut microbial diversity of rats fed with the BS-WP diet was significantly (P < 0.05) higher than that of the other groups. The difference in dietary protein corresponded with an alteration of fecal amino acids and their metabolites, and tryptophan and tyrosine metabolism were the key mechanisms leading to the changes in fecal microbial composition. CONCLUSION: Dietary protein sources played an important role in the growth and development of rats by influencing intestinal metabolism and microbial composition. The BS-WP blended protein diet was more conducive to nutrient absorption than the single protein diet. Furthermore, blended protein increased the diversity of intestinal microbes and aided the establishment of intestinal barrier function.

Underpotential Co-deposition of Au-Cu alloys: switching the underpotentially deposited element by selective complexation.

Underpotential deposition and monolayer replacement processes are widely used for the synthesis of core/shell catalysts and heterointerfaces. Conventionally, only the more noble metal can be underpotentially deposited on or replace the less noble metal, limiting the number of accessible material configurations. We show here that the reverse process is possible, using the Au-Cu pair as a model system. By tuning the redox potentials of the two components via use of strong, selective metal ion complexes, Au-Cu alloys could be synthesized at will by (i) conventional underpotential co-deposition, whereby Cu is reduced at underpotential in parallel with the overpotential deposition of Au, or (ii) the reverse process, where Au is reduced at underpotential, while Cu is deposited at overpotential. Selective complexation also draws the redox potential of Au and Cu closer, resulting in co-deposition under activation control for the noble metal and precise alloy composition control by the applied potential, enabling in principle the formation of arbitrary metal or alloy interfaces. The alloys resulting from the two processes exhibit distinct enthalpy of mixing, suggesting different degrees of short-range order and dissimilar atomic configurations. These findings open new perspectives on underpotential deposition phenomena and possibly new synthetic opportunities in electrodeposition.

Electrodeposition of Fe-Pt films with low oxide content using an alkaline complexing electrolyte.

Electrochemical deposition of equiatomic Fe-Pt from complexing electrolytes provides precise tuning of alloy stoichiometry, enables close control of the growth process, and results in limited oxygen incorporation. The films grow epitaxially on oriented substrates and the low oxygen content favors transformation from the as-deposited cubic to the high anisotropy L1(0) phase and magnetic hardening upon thermal annealing at temperatures (400-450 degrees C) much lower than previously achieved by other plating processes.