| 1. |
- Jin, Ying, et al.
(författare)
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"Soap bubble" sign as an imaging marker for posterior fossa ependymoma Group B
- 2023
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Ingår i: Neuroradiology. - : Springer. - 0028-3940 .- 1432-1920. ; 65, s. 1707-1714
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To investigate the predictive value of the "soap bubble" sign on molecular subtypes (Group A [PFA] and Group B [PFB]) of posterior fossa ependymomas (PF-EPNs).Methods: MRI scans of 227 PF-EPNs (internal retrospective discovery set) were evaluated by two independent neuroradiologists to assess the "soap bubble" sign, which was defined as clusters of cysts of various sizes that look like "soap bubbles" on T2-weighted images. Two independent cohorts (external validation set [n = 31] and prospective validation set [n = 27]) were collected to validate the "soap bubble" sign.Results: Across three datasets, the "soap bubble" sign was observed in 21 PFB cases (7.4% [21/285] of PF-EPNs and 12.9% [21/163] of PFB); none in PFA. Analysis of the internal retrospective discovery set demonstrated substantial interrater agreement (1st Rating: kappa = 0.71 [0.53-0.90], 2nd Rating: kappa = 0.83 [0.68-0.98]) and intrarater agreement (Rater 1: kappa = 0.73 [0.55-0.91], Rater 2: kappa = 0.74 [0.55-0.92]) for the "soap bubble" sign; all 13 cases positive for the "soap bubble" sign were PFB (p = 0.002; positive predictive value [PPV] = 100%, negative predictive value [NPV] = 44%, sensitivity = 10%, specificity = 100%). The findings from the external validation set and the prospective validation set were similar, all cases positive for the "soap bubble" sign were PFB (p < 0.001; PPV = 100%).Conclusion: The "soap bubble" sign represents a highly specific imaging marker for the PFB molecular subtype of PF-EPNs.
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| 2. |
- Liu, Qing, et al.
(författare)
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Unraveling the unique role of brown graphitic carbon nitride in robust CO2 photoreduction
- 2023
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Ingår i: Applied Surface Science. - : ELSEVIER. - 0169-4332 .- 1873-5584. ; 615
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Tidskriftsartikel (refereegranskat)abstract
- Photocatalytic CO2 reduction is one of the important means to alleviate the energy crisis. In this work, an oxygen linked and brown graphitic carbon nitride (GACN) was successfully prepared by thermal polymerization after oil bath method. GACN introduced oxygen atoms on surface of BulkCN. Various characterizations of the material show that the prepared GACN has a different structure and higher photoelectronic activity compared to BulkCN. GACN possessed strong photocatalytic CO2 reduction capacity, and the photocatalytic activity was significantly improved compared with BulkCN. In view of density functional theory calculations, it is proved that the oxygen atoms introduced by GACN increase CO2 photoreaction reactivity, enhance electronic activity and reduce the reaction energy barrier. This work can have a positive effect on the photocatalytic application of g-C3N4 with the existence of oxygen atoms.
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| 3. |
- Zhu, Xingwang, et al.
(författare)
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Stacking Engineering of Heterojunctions in Half-Metallic Carbon Nitride for Efficient CO2 Photoreduction
- 2023
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Ingår i: Advanced Science. - : WILEY. - 2198-3844.
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Tidskriftsartikel (refereegranskat)abstract
- Enhancing charge separation in semiconductor photocatalysts is a major challenge for efficient artificial photosynthesis. Herein, a compact heterojunction is designed by embedding half-metallic C(CN)(3) (hm-CN) hydrothermally in BiOBr (BOB) as the backbone. The interface between hm-CN and BOB is seamless and formed by covalent bonding to facilitate the transmission of photoinduced electrons from BOB to hm-CN. The transient photocurrents and electrochemical impedance spectra reveal that the modified composite catalyst exhibits a larger electron transfer rate. The photocatalytic activity of hm-CN/BOB increases significantly as indicated by a CO yield that is about four times higher than that of individual components. Density-functional theory calculations verify that the heterojunction improves electron transport and decreases the reaction energy barrier, thus promoting the overall photocatalytic CO2 conversion efficiency. The half-metal nitride coupled semiconductor heterojunctions might have large potential in artificial photosynthesis and related applications.
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