ABSTRACT
The bimetallic 2D conductive MOFs of M1Pc-M2-O, possessing dual metal sites to realize flexible molecular-level structural modification, are brilliant catalysts for electrochemical CO2 reduction. However, the bimetallic centers bring about the complex regulatory mechanism of catalytic activity and obscure principles for catalyst design. Herein, systematical theoretical investigation unravels intrinsic descriptors to design favorable M1Pc-M2-O catalysts based on the discovered coarse-fine two-stage activity regulation mechanism. The reaction site controls the M-COOH distance of the key intermediate and therefore affects the reaction kinetics for the first stage of coarse regulation. The other metal site influents the d-band center of the reaction site and thus constitutes the second stage of fine regulation. The coarse and fine regulation are related to the valence electrons (V), electronegativity (E), and bond length (LM-N/O) between the metal and coordination atoms. The intrinsic descriptor Ï = (4 × VM1 × (EM1 + EN/O)/EN/O + VM2 × (EM2 + EN/O)/EN/O) × LM1-N/O (with a coefficient ratio of 4 : 1) was eventually established and correlated well with the reported experiments. On this basis, the favorable catalysts CoPc-Zn-O and CoPc-Co-O were located. The research results could contribute to the diversity of bimetallic 2D c-MOFs in CO2RR.
ABSTRACT
The aim of the present study was to investigate the expression of microRNA-218 (miRNA-218) in the serum and cervical tissue and its association with the clinicopathological features of cervical cancer (CC). The expression of miRNA-218 was detected in the serum and cervical tissue of 112 patients with CC and 50 age-matched hysteromyoma patients via the reverse transcription-quantitative polymerase chain reaction. The clinical data were collected and the association between the expression of miRNA-218 and the clinicopathological characteristics of the patients was analyzed. The expression of miRNA-218 in the cancer group was significantly decreased in the cervical tissue and serum compared with that in the control group (P<0.001). The decreased expression of miRNA-218 was associated with a later International Federation of Gynecology and Obstetrics stage, a more invasive pathological type and lymphatic node metastasis but not with age, age at menarche, menopausal status, number of pregnancies and deliveries, family history of cancer or tumor size. In conclusion, miRNA-218 was found to be downregulated in the cancer tissue and serum of the patients with CC. The decreased expression of miRNA-218 in CC was associated with the invasiveness of the tumor.
