RESUMO
The application of resistive random-access memory (RRAM) in storage and neuromorphic computing has attracted widespread attention. Benefitting from the quantum effect, transition metal dichalcogenides (TMD) quantum dots (QDs) exhibit distinctive optical and electronic properties, which make them promising candidates for emerging RRAM. Here, we show a high-performance forming-free flexible RRAM based on high-quality tin disulfide (SnS2) QDs prepared by a facile liquid phase method. The RRAM device demonstrates high flexibility with a large on/off ratio of â¼106 and a long retention time of over 3 × 104 s. The excellent switching behavior of the memristor is elucidated by a charge trapping/de-trapping mechanism where the SnS2 QDs act as charge trapping centers. This study is of significance for the understanding and development of TMD QD-based flexible memristors.
RESUMO
Six new cadinane-type sesquiterpenoids, named Chimnitensin A-F (1-6) were isolated from the leaves of Chimonanthus nitens Oliv. Their structures were elucidated by comprehensive spectroscopic analyses and comparison with structurally related known analogues. In vitro MTT assay showed that all six compounds had cytotoxicity against two selected human breast cancer cell lines (MDA-MB-468 and MDA-MB-231), which indicate their potential of developing into anticancer drugs.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Calycanthaceae/química , Sesquiterpenos Policíclicos/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular Tumoral , China , Humanos , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Folhas de Planta/química , Sesquiterpenos Policíclicos/isolamento & purificaçãoRESUMO
Chimonanthus plants widely distributed in southern area of China, which have a long history of edibles and medicine. Phytochemical investigations have shown that Chimonanthus produced 143 non-volatile constituents, including alkaloids, flavonoids, terpenoids, coumarins and others, which exhibit significant anti-oxidant, anti-bacterial, anti-cancer, anti-inflammatory, antihyperglycemic, antihyperlipidemic and other biological activities. On the basis of systematic reviewing of literatures, this article overviews the non-volatile constituents and pharmacology of Chimonanthus from domestic and foreign over the last 30 years (until June 2018), and may provide a useful reference for the further development of Chimonanthus.