Abstract Effect of extrusion cooking using different corn starch contents on the physicochemical properties (expansion ratio, bulk density, color, hardness, protein in vitro digestibility, crude protein content, thermal properties and microstructure) of tuna meat-based extrudates was investigated. The results showed that the increased corn starch content led to darker, greener, yellower and lower crude protein content of extrudates, but no significant difference was observed in expansion ratio, bulk density and hardness. The lowest protein in vitro digestibility of 82.83±0.39% appeared when the corn starch content was 20 wt%. The results of DSC revealed that tuna meat with corn starch content of 30 wt% and 20 wt% had the highest and lowest denaturation temperature of 99.4oC and 81.9 oC, respectively. The results of SEM indicated that the extrudate with 30 wt% corn starch content possessed the more integrated and distinct muscle fibers. Besides, the acceptability of the extrudate with 30 wt% corn starch content was significant better than others (p˂0.05). These results revealed that the tuna meat-based extrudates using 30 wt% of corn starch exhibited desirable physicochemical properties.

Summary Diabetic nephropathy is the main cause of chronic kidney disease, and represents the most common and serious complication of diabetes. The exact pathogenesis is complex and not elucidated. Several factors and mechanisms contribute to the development and outcome of diabetic nephropathy. An early diagnosis and intervention may slow down disease progression. A variety of biological markers associated with diabetic nephropathy were found in recent years, which was important for predicting the occurrence and development of the disease. Therefore, this article provides an overview of early biomarkers that are associated with diabetic nephropathy.

A three-dimensional finite element model used to simulate the bolted joint is created using ABAQUS package. The stress concentration factors at the roots of the thread are first studied with a preload of 38.4 kN. Under harmonic transverse shear displacement, not only the stress variations at ten specified points of the first thread but also contact conditions between the contacting surfaces are studied. By changing the preload value, relative displacement, the coefficient of friction between the two clamped plates successively and the loading frequency, their effects on the hysteresis loops of the transverse load versus the relative displacement of the joint are then analyzed. Finally the hysteresis loops are produced by the Masing model. It is found that due to the greatest stress concentration factor, fatigue failure will occur at the root of the first thread. With the increase of preload value, the amplitude of displacement and the coefficient of friction, frictional energy dissipation of the joint increases. Very good agreement is achieved between the hysteresis loops produced from the fourth-order Masing model and the detailed ABAQUS model and therefore the fourth-order Masing model can replace the time-consuming finite element model.

Four novel pleuromutilin derivatives with butyl amine group in the C-14 side-chain were designed, synthesized and confirmed by FT-IR, ¹H-NMR and HR-MS. The results of antibacterial activity showed that the antibacterial activity of pleuromutilin derivatives could be affected by the steric hindrance of their C-14 side-chain.

An efficient method for the rapid separation and purification of polyphenols from artichoke by polyamide column chromatography in combination with high-speed counter-current chromatography (HSCCC) was successfully built. The crude ethanol extracts from dry artichoke were first pre-separated by polyamide column chromatography and divided in two parts as sample 1 and sample 2. Then, the samples were further separated by HSCCC and yielded 7.8 mg of chlorogenic acid (compound I), 24.5 mg of luteolin-7-O-β-D-rutinoside (compound II), 18.4 mg of luteolin-7-O-β-D-glucoside (compound III), and 33.4 mg of cynarin (compound IV) with purity levels of 92.0%, 98.2%, 98.5%, and 98.0%, respectively, as determined by high-performance liquid chromatography (HPLC) method. The chemical structures of these compounds were identified by electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR).