A Universal Perovskite/C60 Interface Modification via Atomic Layer Deposited Aluminum Oxide for Perovskite Solar Cells and Perovskite-Silicon Tandems.

The primary performance limitation in inverted perovskite-based solar cells is the interface between the fullerene-based electron transport layers and the perovskite. Atomic layer deposited thin aluminum oxide (AlOX) interlayers that reduce nonradiative recombination at the perovskite/C60 interface are developed, resulting in >60 millivolts improvement in open-circuit voltage and 1% absolute improvement in power conversion efficiency. Surface-sensitive characterizations indicate the presence of a thin, conformally deposited AlOx layer, functioning as a passivating contact. These interlayers work universally using different lead-halide-based absorbers with different compositions where the 1.55 electron volts bandgap single junction devices reach >23% power conversion efficiency. A reduction of metallic Pb0 is found and the compact layer prevents in- and egress of volatile species, synergistically improving the stability. AlOX-modified wide-bandgap perovskite absorbers as a top cell in a monolithic perovskite-silicon tandem enable a certified power conversion efficiency of 29.9% and open-circuit voltages above 1.92 volts for 1.17 square centimeters device area.

Circulating hematopoietic stem cells, endothelial progenitor cells and cancer stem cells in hepatocellular carcinoma patients: contribution to diagnosis and prognosis.

Background and aim: Circulating hematopoietic stem cells (HSCs), circulating endothelial progenitor cells (EPCs) and cancer stem cells (CSCs) contribute to tumor development and progression and can predict patient outcome. The aim of this study was to investigate the frequency of circulating HSCs, EPCs and CSCs in the peripheral blood of patients with hepatocellular carcinoma (HCC) and to explore their potential prognostic significance for HCC patients.Methods: The study included 30 HCC patients and 20 healthy controls. The HSCs and EPCs were enumerated with CD45, CD34, CD133, CD144 markers, while CSCs were enumerated with CD45, CD44, CD133 markers using flow cytometry.Results: The mean percentages of circulating HSCs were significantly lower in HCC patients than the controls (p = .001), whereas the mean percentages of EPCs within the HSCs subpopulation were significantly higher in the HCC patients than the controls (p = .002). The absolute count of CSCs within 100,000 peripheral blood mononuclear cells was 23.5 ± 3.4 in the HCC patients. Also, the mean percentages of circulating HSCs, EPCs and the number of CSCs were significantly increased in patients with multiple hepatic focal lesions than in patients with a single hepatic focal lesion. Both circulating HSCs and EPCs showed significant positive correlation with the level of AFP and with the numbers of CSCs. In the meantime, the numbers of CSCs revealed significant direct correlation with ALT, AST and AFP levels. The one-year overall survival (OS) of the patients was 77.5%. High levels of CSCs, HSCs and EPCs at diagnosis were all associated with worse outcome for the HCC patients.Conclusions: Significant changes in the levels of the circulating HSCs, EPCs and CSCs occur in HCC. These changes help the diagnosis and the prediction of HCC outcome, as higher levels of these cells are associated with worse OS.

Preoperative Grading of Glioma Using Dynamic Susceptibility Contrast MRI: Relative Cerebral Blood Volume Analysis of Intra-tumoural and Peri-tumoural Tissue.

OBJECTIVES: To assess the usefulness of intra-tumor and peri-tumoral relative cerebral blood volume (rCBV) in preoperative glioma grading. PATIENTS AND METHODS: 21 patients with histopathologically confirmed glioma were included. Imaging was achieved on a 1.5T MRI scanner. Dynamic susceptibility contrast (DSC) MRI was performed using T2* weighted gradient echo-planner imaging (EPI). Multiple regions of interest (ROIs) have been drawn in the hotspots regions, the highest ROI has been selected to represent the rCBV of each intra-tumoral and peri-tumoral regions. Based on histopathology, tumors were subdivided into low grade and high grade. Receiver operating characteristic analysis (ROC) of rCBV, of both intra-tumoral and peri-tumoral regions, was performed to find cut-off values between high and low-grade tumors. The resulting sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. RESULTS: Based on the histopathology, high-grade glioma (HGG) represented 76.2% whereas low-grade glioma (LGG) represented 23.8%. Both intra-tumoral and peri-tumoral rCBV of HGG were significantly higher than those of LGG. A cut-off value >2.9 for intra-tumoral rCBV provided sensitivity, specificity, and accuracy of 80%, 100%, and 85.7% respectively to differentiate between HGG and LGG. Additionally, the cut-off value >0.7 for peri-tumoral rCBV provided sensitivity, specificity, and accuracy of 100%, 66.6%, and 90.5% respectively to differentiate between HGG and LGG. CONCLUSION: rCBV of each of intra-tumoral and peri-tumoral rCBV are significantly reliable for the preoperative distinction between HGG and LGG. Combined intra-tumoral and peri-tumoral rCBV provides overall better diagnostic accuracy and helps to decrease the invasive intervention for non-surgical candidates.