Broadband high-efficiency dielectric metalenses based on quasi-continuous nanostrips

Benefiting from the abrupt phase changes within subwavelength thicknesses,metasurfaces have been widely applied for lightweight and compact optical systems.Simultaneous broadband and high-efficiency characteristics are highly attractive for the practical implementation of metasurfaces.However,current metasurface devices mostly adopt discrete micro/nano structures,which rarely realize both merits simultaneously.In this paper,dielectric metasurfaces composed of quasi-continuous nanostrips are proposed to overcome this limitation.Via quasi-continuous nanostrips metasurface,a normal focusing metalens and a superoscillatory lens overcoming the diffraction limit are designed and experimentally demonstrated.The quasi-continuous metadevices can operate in a broadband wavelength ranging from 450 nm to 1000nm and keep a high power efficiency.The average efficiency of the fabricated metalens reaches 54.24%,showing a significant improvement compared to the previously reported metalenses with the same thickness.The proposed methodology can be easily extended to design other metadevices with the advantages of broadband and high-efficiency in practical optical systems.

Drug repurposing against coronavirus disease 2019(COVID-19):A review

Since December 2019,severe acute respiratory syndrome coronavirus 2 has been found to be the culprit in the coronavirus disease 2019(COVID-19),causing a global pandemic.Despite the existence of many vaccine programs,the number of confirmed cases and fatalities due to COVID-19 is still increasing.Furthermore,a number of variants have been reported.Because of the absence of approved anticoronavirus drugs,the treatment and management of COVID-19 has become a global challenge.Under these circumstances,drug repurposing is an effective method to identify candidate drugs with a shorter cycle of clinical trials.Here,we summarize the current status of the application of drug repurposing in COVID-19,including drug repurposing based on virtual computer screening,network pharmacology,and bioactivity,which may be a beneficial COVID-19 treatment.

Papers published from 1995 to 2012 by six Traditional Chinese Medicine universities in China: a bibliometric analysis based on science citation index

OBJECTIVE: The quality and quantity of published research papers are important in both scientific and technology fields. Although there are several bibliometric studies based on citation analysis, very few have focused on research related to Traditional Chinese Medicine in China. METHODS: The bibliometric method used in this study included the following focuses: publication outputs for each year, paper type, language of publication, distribution of internationally collaborative countries, sources of funding, authorization number, distribution of institutes regarding collaborative publications, research fields, distribution of out-puts in journals, citation data, and h-index. RESULTS: A total of 3809 papers published from 1995 to 2012 were extracted from the science citation index(SCI). The cumulative number of papers from all six universities is constantly increasing. The United States attained the dominant position regarding complementary and alternative medicine research. The Chinese Academy of Sciences was the greatest participator in collaborative efforts. Research field analysis showed that the research mainly focused on pharmacology pharmacy, chemistry, integrative complementary medicine, plant sciences, and biochemistry molecular biology. The Shanghai University of Chinese Medicine had the most citations. CONCLUSION: In recent years, in terms of SCI papers, the six Traditional Chinese Medicine universities studied here have made great advances in scientific research.