Antitumor Research on Artemisinin and Its Bioactive Derivatives

Cancer is the leading cause of human death which seriously threatens human life.The antimalarial drug artemisinin and its derivatives have been discovered with considerable anticancer properties.Simultaneously,a variety of target-selective artemisinin-related compounds with high efficiency have been discovered.Many researches indicated that artemisinin-related compounds have cytotoxic effects against a variety of cancer cells through pleiotropic effects,including inhibiting the proliferation of tumor cells,promoting apoptosis,inducing cell cycle arrest,disrupting cancer invasion and metastasis,preventing angiogenesis,mediating the tumor-related signaling pathways,and regulating tumor microenvironment.More importantly,artemisinins demonstrated minor side effects to normal cells and manifested the ability to overcome multidrug-resistance which is widely observed in cancer patients.Therefore,we concentrated on the new advances and development of artemisinin and its derivatives as potential antitumor agents in recent 5 years.It is our hope that this review could be helpful for further exploration of novel artemisinin-related antitumor agents.

Quebrachitol:Global Status and Basic Research

Recently,there has been a renewed interest in the natural-products-inspired drugs.Quebrachitol(QCT)is one of naturally occurring optically active cyclitols that has now received considerable attention.Until the last decade,it came to be a starting point for the lead discovery.In this review,we had a discussion on the basic research of QCT,including its source,structure,properties,and the recent advances on its application.The biological activities and QCT-inspired leads that are potentially effective for treating human diseases were also discussed.

PM_(2.5) in China:Measurements,sources,visibility and health effects,and mitigation

Concern over the health effects of fine particles in the ambient environment led the U.S. Environmental Protection Agency to develop the first standard for PM2.5 （particulate matter less than 2.5 μm） in 1997. The Particle Technology Laboratory at the University of Minnesota has helped to establish the PM2.5 standard by developing many instruments and samplers to perform atmospheric measurements. In this paper, we review various aspects of PM2.5, including its measurement, source apportionment, visibility and health effects, and mitigation. We focus on PM2.s studies in China and where appropriate, compare them with those obtained in the U.S. Based on accurate PM2.5 sampling, chemical analysis, and source apportionment models, the major PM2.5 sources in China have been identified to be coal combustion, motor vehicle emissions, and industrial sources. Atmospheric visibility has been found to correlate well with PM2.s concentration. Sulfate, ammonium, and nitrate carried by PM2.s, commonly found in coal burning and vehicle emissions, are the dominant contributors to regional haze in China. Short-term exposure to PM2.s is strongly associated with the increased risk of morbidity and mortality from cardiovascular and respiratory diseases in China. The strategy for PMzs mitigation must be based on reducing the pollutants from the two primary sources of coal-fired power plants and vehicle emissions. Although conventional Particulate Emission Control Devices （PECD） such as electrostatic precipitators in Chinese coal-fired power plants are generally effective for large particles, most of them may not have high collection efficiency of PM2.5. Baghouse filtration is gradually incorporated into the PECD to increase the PM2.5 collection efficiency. By adopting stringent vehicle emissions standard such as Euro 5 and 6, the emissions from vehicles can be gradually reduced over the years. An integrative approach, from collaboration among academia, government, and industries, can effectively manage and mitigate the PM2.s pollution in China.