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Solar energy has been the most emphasized issue in recent years, as it is sustainable and causes zero emissions. In the solar cell industry, new manufacturing protocols have led to the development of materials with enhanced properties. Over the past decades, perovskite solar cells (PSC) have obtained a power conversion efficiency (PCE) to be 25% due to the development of synthesis techniques, electrode materials, etc. There is an important relationship between the thickness of the transport layers (hole and electron) in the case of improving the yield of perovskite solar cells. We have investigated the influence of the acid-assisted and acetylacetone-assisted (AA) methods on TiO2 films and thus the effect on the PCE of perovskite solar cells. Perovskite (CH3NH3PbI3) layer and different compact TiO2 (c-TiO2) layers have been coated by the spin coating method, and the overall experimental section is made in the nitrogen medium at room temperature. Through an acid-assisted method, the cracked c-TiO2 film was formed. The planar solar cell structure of ITO/AA-TiO2/CH3NH3PbI3/P3HT/Ag resulted in 0.03% of PCE. However, the perovskite solar cells with a mesoporous solar cell structure of ITO/ AA-TiO2/m-TiO2 /CH3NH3PbI3/P3HT/Ag resulted in 0.1% of PCE. [ABSTRACT FROM AUTHOR]

The effects of the addition of colloidal silica (cSiO2) and solvents used in the catalyst preparation on the activity and stability of WO3-TiO2 catalysts are reported in this paper. The highly stable and selective WO3 supported cSiO2-TiO2 catalysts were prepared and tested in the vapor-phase glycerol oxy-dehydration. WO3-TiO2 catalysts with and without cSiO2 were characterized by XRD, SEM, NH3-TPD, infrared spectroscopy of pyridine (FTIR-Py), XPS, RAMAN, and N2 adsorption-desorption (BET). The highest medium strength acidity and optimum Brønsted to Lewis acid site ratio of WO3 catalysts were achieved upon the addition of colloidal silica (cSiO2) onto TiO2 support. The medium strength acidity of Brønsted acid sites was responsible for the improved acrolein selectivity and stability. The other major factors in glycerol conversion and acrolein selectivity were the glycerol content and liquid hourly space velocity. The yield to acrolein was up to 70% and kept almost constant in a 50 h continuous run at 300 °C. The gradual decrease in glycerol conversion was due to the build-up of oxygen-containing carbonaceous materials deposited on the catalyst surface. [ABSTRACT FROM AUTHOR]

The catalytic performance of tungsten oxide, WO3-KIT-6 in the selective dehydration of glycerol to acrolein was studied. The chemical and structural properties of the catalysts were examined by X-ray diffraction (XRD), nitrogen adsorption–desorption (BET) isotherms, temperature-programmed ammonia (TPD-NH3) desorption, and X-ray photoelectron spectroscopy (XPS), SEM, TGA, Raman and pyridine adsorption FTIR. Catalysts synthesized by the hydrolytic sol–gel (HSG) method showed quantitative conversion of glycerol and acrolein selectivity. The medium-strength surface acidity of the catalyst and mesoporosity played a crucial role in the dehydration of glycerol to acrolein. The maximum stable acrolein selectivity of 55% at 98% glycerol conversion was obtained over 25 wt%W-KIT-6(100) (7.9 nm average pore size) catalyst having the highest concentration of medium-strength acid sites. The effects of mesopore sizes and the selective dehydration of glycerol were elucidated. The catalyst with the largest mesopores diameter displayed higher reactivity, longer lifetime, and improved selectivity. [ABSTRACT FROM AUTHOR]

Background: Medulloblastomas are a major cause of cancer-related mortality in the pediatric population. Four molecular groups have been identified, and these molecular groups drive risk stratification, prognostic modeling, and the development of novel treatment modalities. It has been demonstrated that radiomics-based machine learning (ML) models are effective at predicting the diagnosis, molecular class, and grades of CNS tumors. Purpose: To assess radiomics-based ML models' diagnostic performance in predicting medulloblastoma subgroups and the methodological quality of the studies. Material and Methods: A comprehensive literature search was performed on PubMed; the last search was conducted on 1 May 2022. Studies that predicted all four medulloblastoma subgroups in patients with histopathologically confirmed medulloblastoma and reporting area under the curve (AUC) values were included in the study. The quality assessments were conducted according to the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) and Checklist for Artificial Intelligence in Medical Imaging (CLAIM). A meta-analysis of radiomics-based ML studies' diagnostic performance for the preoperative evaluation of medulloblastoma subgrouping was performed. Results: Five studies were included in this meta-analysis. Regarding patient selection, two studies indicated an unclear risk of bias according to the QUADAS-2. The five studies had an average CLAIM score and compliance score of 23.2 and 0.57, respectively. The meta-analysis showed pooled AUCs of 0.88, 0.82, 0.83, and 0.88 for WNT, SHH, group 3, and group 4 for classification, respectively. Conclusion: Radiomics-based ML studies have good classification performance in predicting medulloblastoma subgroups, with AUCs >0.80 in every subgroup. To be applied to clinical practice, they need methodological quality improvement and stability. [ABSTRACT FROM AUTHOR]

The metastasis suppressor, N-myc downstream regulated gene-1 (NDRG1), inhibits pro-oncogenic signaling in pancreatic cancer (PC). This investigation dissected a novel mechanism induced by NDRG1 on WNT/β-catenin signaling in multiple PC cell types. NDRG1 overexpression decreased bcatenin and downregulated glycogen synthase kinase-3b (GSK-3b) protein levels and its activation. However, β-catenin phosphorylation at Ser33, Ser37, and Thr41 are classically induced by GSK-3b was significantly increased after NDRG1 overexpression, suggesting a GSK-3β-independent mechanism. Intriguingly, NDRG1 overexpression upregulated protein kinase Ca (PKCa), with PKCa silencing preventing β-catenin phosphorylation at Ser33, Ser37, and Thr41, and decreasing bcatenin expression. Further, NDRG1 and PKCa were demonstrated to associate, with PKCa stabilization occurring after NDRG1 overexpression. PKCa half-life increased from 1.5 ± 0.8 h (3) in control cells to 11.0 ± 2.5 h (3) after NDRG1 overexpression. Thus, NDRG1 overexpression leads to the association of NDRG1 with PKCa and PKCa stabilization, resulting in β-catenin phosphorylation at Ser33, Ser37, and Thr41. The association between PKCa, NDRG1, and β-catenin was identified, with the formation of a potential metabolon that promotes the latter β-catenin phosphorylation. This antioncogenic activity of NDRG1 was multi-modal, with the above mechanism accompanied by the downregulation of the nucleocytoplasmic shuttling protein, p21-activated kinase 4 (PAK4), which is involved in β-catenin nuclear translocation, inhibition of AKT phosphorylation (Ser473), and decreased β-catenin phosphorylation at Ser552 that suppresses its transcriptional activity. These mechanisms of NDRG1 activity are important to dissect to understand the marked anti-cancer efficacy of NDRG1-inducing thiosemicarbazones that upregulate PKCa and inhibit WNT signaling. [ABSTRACT FROM AUTHOR]

The di-2-pyridylthiosemicarbazone (DpT) analogs demonstrate potent and selective anti-proliferative activity against human tumors. The current investigation reports the synthesis and chemical and biological characterization of the Fe(iii), Co(iii), Ni(ii), Cu(ii), Zn(ii), Ga(iii), and Pd(ii) complexes of the promising second generation DpT analog, di-2-pyridylketone-4-ethyl-4-methyl-3-thiosemicarbazone (Dp4e4mT). These studies demonstrate that the Dp4e4mT Co(iii), Ni(ii), and Pd(ii) complexes display distinct biological activity versus those with Cu(ii), Zn(ii), and Ga(iii) regarding anti-proliferative efficacy against cancer cells and a detrimental off-target effect involving oxidation of oxy-myoglobin (oxy-Mb) and oxy-hemoglobin (oxy-Hb). With regards to anti-proliferative activity, the Zn(ii) and Ga(iii) Dp4e4mT complexes demonstrate facile transmetallation with Cu(ii), resulting in efficacy against tumor cells that is strikingly similar to the Dp4e4mT Cu(ii) complex (IC 50 : 0.003-0.006 μM and 72 h). Relative to the Zn(ii) and Ga(iii) Dp4e4mT complexes, the Dp4e4mT Ni(ii) complex demonstrates kinetically slow transmetallation with Cu(ii) and intermediate anti-proliferative effects (IC 50 : 0.018-0.076 μM after 72 h). In contrast, the Co(iii) and Pd(ii) complexes demonstrate poor anti-proliferative activity (IC 50 : 0.262-1.570 μM after 72 h), probably due to a lack of transmetallation with Cu(ii). The poor efficacy of the Dp4e4mT Co(iii), Ni(ii), and Pd(ii) complexes to transmetallate with Fe(iii) markedly suppresses the oxidation of oxy-Mb and oxy-Hb. In contrast, the 2 : 1 Dp4e4mT: Cu(ii), Zn(ii), and Ga(iii) complexes demonstrate facile reactions with Fe(iii), leading to the redox active Dp4e4mT Fe(iii) complex and oxy-Mb and oxy-Hb oxidation. This study demonstrates the key role of differential transmetallation of Dp4e4mT complexes that has therapeutic ramifications for their use as anti-cancer agents., Competing Interests: No financial conflict of interest exists., (This journal is © The Royal Society of Chemistry.)