Shandong University

About: Shandong University is a education organization based out in Jinan, Shandong, China. It is known for research contribution in the topics: Laser & Cancer. The organization has 99070 authors who have published 99160 publications receiving 1625094 citations. The organization is also known as: Shāndōng Dàxué.

Polaron relaxation and variable-range-hopping conductivity in the giant-dielectric-constant material Ca Cu 3 Ti 4 O 12

Abstract: Transport and dielectric measurements have been performed in $\mathrm{Ca}{\mathrm{Cu}}_{3}{\mathrm{Ti}}_{4}{\mathrm{O}}_{12}$ ceramics. The bulk ac conductivity shows a power-law behavior at different temperatures, which is related to polaron relaxation. The temperature dependence of the bulk dc conductivity indicates a variable-range-hopping mechanism. The dielectric relaxation frequency deviates from the Arrhenius behavior. An equivalent circuit is used to explain qualitatively the experimental data of $\mathrm{Ca}{\mathrm{Cu}}_{3}{\mathrm{Ti}}_{4}{\mathrm{O}}_{12}$.

Acetoin Metabolism in Bacteria

Abstract: Acetoin is an important physiological metabolite excreted by many microorganisms. The excretion of acetoin, which can be diagnosed by the Voges Proskauer test and serves as a microbial classification marker, has its vital physiological meanings to these microbes mainly including avoiding acification, participating in the regulation of NAD/NADH ratio, and storaging carbon. The well-known anabolism of acetoin involves α-acetolactat synthase and α-acetolactate decarboxylase; yet its catabolism still contains some differing views, although much attention has been focused on it and great advances have been achieved. Current findings in catabolite control protein A (CcpA) mediated carbon catabolite repression may provide a fuller understanding of the control mechanism in bacteria. In this review, we first examine the acetoin synthesis pathways and its physiological meanings and relevancies; then we discuss the relationship between the two conflicting acetoin cleavage pathways, the enzymes of the acetoin dehydro...