RESUMO
The electronic and transport properties of the half-Heusler compound LaPtSb are investigated by performing first-principles calculations combined with semi-classical Boltzmann theory and deformation potential theory. Compared with many typical half-Heusler compounds, LaPtSb exhibits an obviously larger power factor at room temperature, especially for the n-type system. Together with the very low lattice thermal conductivity, the thermoelectric figure of merit (ZT) of LaPtSb can be optimized to a record high value of 2.2 by fine tuning the carrier concentration.
RESUMO
Although important progress has been achieved in combating HIV/AIDs over the past 30 years, HIV/AIDs is still a serious threat to today's world. In China, figures on the incidence of this disease have painted a less than optimistic outlook. As the prevailing methods of preventing HIV/AIDS are all partially effective, novel and effective preventive interventions are needed in order to control the spread of the disease. Pre-exposure prophylaxis (PrEP) is one of the most promising prevention strategies and has garnered great attention worldwide. Current clinical trials on the efficacy and safety of this strategy have had some favorable results though major challenges around the world remain. Thus, China has taken an active part in the PrEP study to limit the prevalence of HIV/AIDS. This article describes the status of the PrEP study and discusses the opportunities and challenges encountered when implementing this strategy in China.