University of Science and Technology of China Jinsong ZhangSelenium is a promising agent for chemoprevention and chemotherapy of cancer. However, presentresearch data indicate the supranutritional dose and even higher level are necessary for better efficacy. Thesedoses approaches toxic dose. The dilemma in selenium argues the exploration of novel selenium form withlower toxicity and higher biological functions is urgent. The long-held opinion is elemental selenium is biologi-cal inert. We show that elemental in nano particles has high bioavailability and substantial low toxicity, indicat-ing its promising application in chemoprevention and chemotherapy.
This review analyzes the research data of selenium in liver diseases conducted by China scientists in recentyears. It is found from these researches that suboptimal selenium in serum is a common phenomenon of liverdiseases, the severer, the more deficient; supplementation of selenium in nutritional level is beneficial for dis-eases control and better recovery of drug treatments; selenium may inhibit hepatitis virus by adjusting immunity,increasing antioxidant defense, and suppressing mutation; selenium at nutritional level could prevent liver fibrosisin rats models as well as liver cancer in either animal models or human
A two-channel thermal dissociation cavity ring down spectroscopy （CRDS） instrument has been built for in situ, real-time measurement of NO2 and total RNO2 （peroxy nitrates and alkyl nitrates） in ambient air, with a NO2 detection limit of 0.10 ppbv at 1 s. A 6-day long measurement was conducted at urban site of Hefei by using the CRDS instrument with a time resolution of 3 s. A commercial molybdenum converted chemiluminescence （Mo-CL） instrument was also used for comparison. The average RNO2 concentration in the 6 days was measured to be 1.94 ppbv. The Mo-CL instrument overestimated the NO2 concentration by a bias of ＋1.69 ppbv in average, for the reason that it cannot distinguish RNO2 from NO2. The relative bias could be over 100% during the afternoon hours when NO2 was low but RNO2 was high.
