ABSTRACT
In this paper, urea-doped ZnO (U-ZnO) is investigated as a modified electron transport layer (ETL) in inverted polymer solar cells (PSCs). Using a blend of Poly{4,8-bis[(2-ethylhexyl)oxy] benzo [1,2-b:4,5-b'] dithiophene-2,6-diyl-alt-3-fluoro-2-[(2-ethylhexyl)carbonyl] thieno [3,4-b] thiophene-4,6-diyl}(PTB7), and [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM) as light absorber, a champion power conversion efficiency (PCE) of 9.15% for U-ZnO ETL based PSCs was obtained, which is 15% higher than that of the pure ZnO ETL based PSCs (7.76%). It was demonstrated that urea helps to passivate defects in ZnO ETL, resulting in enhanced exciton dissociation, suppressed charge recombination and efficient charge extraction efficiency. This work suggests that the utilization of the U-ZnO ETL offer promising potential for achieving highly efficient PSCs.
ABSTRACT
AIM: Accumulated evidence has suggested a relationship between S100A4 protein expression and the development and progression of pancreatic cancer (PC) while its role in diagnosis and prognosis of PC still keeps inconsistent. To obtain definitive associations between S100A4 and PC, a meta-analysis was conducted. MATERIALS AND METHODS: The PubMed and Chinese National Knowledge Infrastructure databases were electronically searched to identify studies reporting an association between S100A4 protein and PC. Statistical analyses were undergone with the utilization of STATA version 12.0 software. RESULTS: Nine clinical studies with a total of 545 tumor samples were included in the meta-analysis. Results revealed that increased S100A4 expression were associated with the tumor-node-metastasis stages of PC (III-IV vs. I-II: odds ratio [OR] =5.50, 95% confidence interval [95% CI] =3.13-9.67, P < 0.001). Also, compared with 1-2 histologic grade of PC samples, S100A4 protein was expressed more frequently in samples with 3-4 histologic grade (grades 1-2 vs. grades 3-4: OR = 2.57, 95% CI = 1.05-6.24, P = 0.038). CONCLUSION: This meta-analysis showed that overexpression of S100A4 seems to be associated with tumor progression and poor prognosis of PC patients.
