Design and development of a single atomic catalyst with high activity is desirable but proved to be very challenging in the renewable energy conversion and storage technologies. As a classic carbon material, graphene has many excellent properties and thus may be a good support to stabilize the isolated metal atoms. However, the oxygen evolution activity of a single cobalt atom supported on graphene is still very low. To improve its performance, support modification has been carried out based on a density functional theory framework for the design predication. In our theoretical study, two nitrogen formats are incorporated to the graphene substrates, including graphitic nitrogen and pyridine-like nitrogen, which are usually observed in experiment. The oxygen evolution process has been envisaged on these single cobalt atom catalysts via gas phase adsorption calculation. The electronic structure on the single Co active site can be effectively regulated by the support modification, which will contribute to its enhanced performance. Henceforth, free energy change diagrams, partial density of states, Raman spectra, and charge density difference are discussed. It is suggested that incorporating pyridine-like nitrogen on graphene is an ideal approach for the supported Co atom to achieve high OER activity, opening up new opportunity for the preparation and application of highly active and stable single atomic catalysts.

Background This study aimed to explore the prevalence and risk factors of anxiety and depression, as well as the association of anxiety and depression with survival profiles in cervical cancer patients underwent surgery. Methods A total of 158 newly diagnosed primary cervical cancer patients who underwent surgical resection were recruited, and another 150 healthy subjects were also included as controls. Anxiety and depression were assessed using the hospital anxiety and depression scale (HADS). Disease-free survival (DFS) and overall survival (OS) were calculated. Results The HADS-anxiety (HADS-A) score, the prevalence and the severity of anxiety were greatly increased in cervical cancer patients compared with controls. Meanwhile, the HADS-depression (HADS-D) score, the prevalence and the severity of depression were also dramatically elevated in cervical cancer patients compared with controls. As for risk factors, diabetes and International Federation of Gynecology and Obstetrics (FIGO) stage II were independent factors for higher anxiety risk, and diabetes as well as lymph node metastasis were independent predictive factors for increased depression risk in cervical cancer patients. Besides, cervical cancer patients with anxiety had less prolonged DFS and OS compared with those without anxiety, and cervical cancer patients with depression had shorter OS compared with those without depression. Conclusions Anxiety and depression are highly prevalent, and associates with worse tumor burden as well as unfavorable survival profiles in cervical cancer patients underwent surgery.

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In the present work, a novel approach was developed for the preparation of Cu2O nanoparticles decorated MnO2 nanosheet (Cu2O@MnO2). Uniformly dispersed Cu2O nanocrystals were produced on the surface of MnO2...