RESUMO
Photocatalytic splitting of water for hydrogen generation is a green and renewable solution for converting solar energy to chemical energy; thus, the development of high-performance and stable photocatalytic materials has emerged as a research hotspot recently. Herein, a heterostructure composite photocatalyst of octahedral CoO uniformly modified with novel nitrogen-doped MXene quantum dots (N-MQDs) is successfully designed using a typical solvothermal approach. The optimum photocatalytic hydrogen evolution efficiency of the prepared N-MQDs@CoO heterojunction composite is 82.54 µmol g-1 h-1 with visible light, which is 16.57 times higher compared to the pure CoO. A series of photoelectrochemical tests were further performed to elucidate the photocatalytic hydrogen evolution mechanism. The remarkable improvement of activity is primarily attributed to the synergistic interaction between the closely spaced interface contacts and energy level matching among high conductivity Ti3C2 MXene quantum dots with CoO octahedra, dramatically hastening the segregation and transfer of photo-generated carriers. This study provides new ideas for the construction of MXene quantum dot-based co-photocatalysts with highly efficient photocatalytic performance and stability toward solar energy conversion applications.
RESUMO
The current preparation methods of carbon quantum dots (CDs) involve many reaction parameters, which leads to many possibilities in the synthesis processes and high uncertainty of the resultant production performance. Recently, machine learning (ML) methods have shown great potential in correlating the selected features in many applications, which can help understand the relevant structure-function relationships of CDs and discover better synthesis recipes as well. In this work, we employ the ML approach to guide the blue CD synthesis in microwave systems. After optimizing the synthesis parameters and conditions, the quantum yield (QY) increases to about 200% higher than the average value of the prepared samples without ML guidance. The obtained CDs are applied as fluorescent probes to monitor hydrogen peroxide (H2O2) in human teeth. The CD probe exhibits a linear relationship with the concentration of H2O2 ranging from 0 to 1.1 M with a lower detection limit of 0.12 M, which can effectively detect the residual H2O2 after bleaching teeth. This work shows that the adopted ML methods have considerable advantages in guiding the synthesis of high-quality CDs, which could accelerate the development of other novel functional materials in energy, biomedical, and environmental remediation applications.
Assuntos
Pontos Quânticos , Carbono , Corantes Fluorescentes , Humanos , Peróxido de Hidrogênio , Aprendizado de Máquina , Micro-OndasRESUMO
Non-small cell lung cancer (NSCLC) is one of the most common malignant tumors in the world, and non-coding RNA (ncRNA) has recently been widely reported to participate in the development of NSCLC. Some ncRNAs, especially microRNAs (miRNAs), are widely reported as tumor drug targets due to their short transcript length and easiness for processing into small molecule compounds. Therefore, exploring the potential roles of specific miRNAs in NSCLC may provide a better understanding of the molecular etiology. In this study, we downloaded the large-scale RNA-seq data from the Cancer Genome Atlas (TCGA) database, and identified 211 differentially expressed miRNAs (121 up-regulated and 90 down-regulated) in NSCLC. Similar to the TCGA database, miR-182-5p was significantly up-regulated in the serum and tissue samples of NSCLC patients. Clinicopathological parameters revealed the positive correlation between miR-182-5p expression and advanced TNM stage. Functional tests showed miR-182-5p overexpression promoted cell proliferation, migration and apoptosis inhibition, while miR-182-5p knockdown weakened the above phenotypes. Besides, advanced glycosylation end-product specific receptor (AGER) was identified as a direct downstream target of miR-182-5p. Alteration of AGER expression or NF-κB inhibitor could partially counteract the bioactive roles induced by miR-182-5p overexpression or knockdown. Further study disclosed down-regulated LINC00173 was negatively corrected with miR-182-5p in NSCLC tissues. LINC00173 could regulate miR-182-5p expression and reversed functional behaviors mediated by miR-182-5p/AGER/NF-κB axis. Taken together, miR-182-5p mediated the malignant phenotypes through NF-κB pathway via targeting AGER, and LINC00173 acted as a potential negative regulator of miR-182-5p in NSCLC cells.