Review on evolution and evaluation of asphalt pavement structures and materials

The purpose of this study was to summarize the wide-range literatures on asphalt pavements, explore the evolution of road pavements, analyze typical asphalt pavement structures, highlight current trends in research and industry, and to recommend future areas of research and development. In this research, road pavement evolution was explored from the earliest roads to the modern pavements. A new method was recommended to categorize asphalt pavement materials into the three large families which may be further sub-divided according to their mechanical parameters. A unified asphalt pavement classification(UAPC) method was proposed and the worldwide asphalt pavements could be divided into six types through the new method. Based o n the UAPC method, 1087 asphalt pavement structures were classified and analyzed to explore the asphalt thickness variation. In order to evaluate asphalt pavement performance, the Chinese design specification was employed for analyzing lives of 29 high-volume pavements and 28 low-volume pavements. Through this research, it was found that:(1) in the past 100 years, asphalt pavement materials and structures had been becoming more and more strong;(2) asphalt layer thicknesses were various from 5 to 60 cm and the overall pavement thicknesses were various from 28 to 160 cm;(3) the long-life pavements in the other countries may become"shorter-life" pavements according to the prediction based on the Chinese specification.

Au nanoclusters suppress chronic lymphocytic leukaemia cells by inhibiting thioredoxin reductase 1 to induce intracellular oxidative stress and apoptosis

Chronic lymphocytic leukaemia （CLL） is a rare blood cancer that always relapses as refractory disease and eventually leads to death. To date, therapeutic options for CLL patients are scarce and there is an urgent need to develop novel chemotherapeutics that are both effective and safe. Gold-containing compounds induce a lethal oxidative and endoplasmic reticulum stress response in cultured and primary CLL cells via inhibition of thioredoxin reductase （TrxR）. However, traditional gold-containing medicines have revealed side effects during clinical applications. Therefore, safer gold-containing drugs are needed to overcome this challenge. In this study, a novel peptide templated gold cluster Au2sSv9 was synthesized and its therapeutic effect on CLL cells was evaluated. This nanocluster could induce cell apoptosis in MEC-1 cells in a dose-dependent manner which correlated with the uptake amount of clusters in cells. As expected, increasing intracellular reactive oxidative species （ROS） in MEC-1 cells was exhibited with the increase of cluster dosage. Further analyses demonstrated the underlying mechanism that the nan- oclusters suppress the activity ofTrxR1, increase the level of intracellular ROS, destroy the mitochondrial membrane potential and finally trigger the mitochondrial apoptotic pathway in MEC-1 cells. Furthermore, the direct interaction between Au2sSv9 clusters and TrxRl was confirmed for the first time by isothermal titration calorimetry. These findings explored the preclinical efficacy and potential mech- anism of gold clusters in CLL therapy and provided a fundamental reference for the development of other novel gold-containing chemotherapeutics to treat CLL.