Heteroatom Donor‐Decorated Polymer‐Immobilized Ionic Liquid Stabilized Palladium Nanoparticles : Efficient Catalysts for Room‐Temperature Suzuki‐Miyaura Cross‐Coupling in Aqueous Media

Palladium nanoparticles stabilized by heteroatom donor‐modified polystyrene‐based polymer immobilized ionic liquids (PdNP@HAD‐PIILP; HAD‐PPh2, OMe, NH2, CN, pyrrolidone) are highly efficient catalysts for the Suzuki‐Miyaura cross‐coupling in aqueous media under mild conditions. Catalyst modified with phosphine was consistently the most efficient as it gave high yields across a range of substrates under mild conditions at low catalyst loadings. Incorporation of polyethylene glycol into the phosphine modified immobilised ionic liquid support improved catalyst efficacy by improving dispersibility and facilitating access to the active site. Moreover, each of the heteroatom modified catalysts was more active than the corresponding unsubstituted imidazolium‐based polystyrene benchmark as well as commercial samples of Pd/C. Catalyst generated in situ from either [PdCl4]@PPh2‐PIILP or its PEGylated counterpart [PdCl4]@PPh2‐PEGPIILP, by reduction with phenylboronic acid, outperformed their pre‐formed counterparts for the vast majority of substrates examined. The turnover frequency of 16,300 h−1 obtained at room temperature is one of the highest to be reported for palladium nanoparticle‐catalysed Suzuki‐Miyaura cross‐coupling between 4‐bromoacetophenone and phenylboronic acid in aqueous media under such mild conditions

PI3K/AKT/mTOR signaling in gastric cancer : epigenetics and beyond.

PI3K/AKT/mTOR pathway is one of the most important signaling pathways involved in normal cellular processes. Its aberrant activation modulates autophagy, epithelial-mesenchymal transition, apoptosis, chemoresistance, and metastasis in many human cancers. Emerging evidence demonstrates that some infections as well as epigenetic regulatory mechanisms can control PI3K/AKT/mTOR signaling pathway. In this review, we focused on the role of this pathway in gastric cancer development, prognosis, and metastasis, with an emphasis on epigenetic alterations including DNA methylation, histone modifications, and post-transcriptional modulations through non-coding RNAs fluctuations as well as H. pylori and Epstein-Barr virus infections. Finally, we reviewed different molecular targets and therapeutic agents in clinical trials as a potential strategy for gastric cancer treatment through the PI3K/AKT/mTOR pathway. [Abstract copyright: Copyright © 2020 Elsevier Inc. All rights reserved.

Augmented expression levels of lncRNAs ecCEBPA and UCA1 in gastric cancer tissues and their clinical significance

Objective(s): As the second cause of cancer death, gastric cancer (GC) is one of the eminent dilemmas all over the world, therefore investigating the molecular mechanisms involved in this cancer is pivotal. Unrestricted proliferation is one of the characteristics of cancerous cells, which is due to deficiency in cell regulatory systems. Long non-coding RNAs (lncRNAs) have emerged as critical regulators of the epigenome. lncRNA extra coding CEBPA (ecCEBPA) is involved in DNA methylation. This lncRNA reduces CEBPA promoter methylation by interacting with DNA methyltransferase 1. lncRNA UCA1 (urothelial carcinoma-associated 1) elevates cell proliferation through the PI3K/Akt signaling pathway which has a critical role in cell growth and apoptosis. The aim of this study was to examine the expression of ecCEBPA and UCA1 genes in GC tissues as well as their clinical significance. Materials and Methods: Total RNA extraction, cDNA synthesis, and quantitative real-time PCR were performed for cells and 80 paired GC tissues. Furthermore, clinical relevance of UCA1 expression was investigated in TCGA cohort data. Results: Our results showed ecCEBPA and UCA1 over-expression in GC tissues. Furthermore, lncRNAs associations with clinicopathological features were demonstrated both in the current and TCGA cohort. Kaplan-Meier analysis indicated that patients with higher UCA1 expression had a worse overall survival in the case of pancreatic and lung adenocarcinomas but not other solid cancer types including GC. Conclusion: These data demonstrate UCA1 and ecCEBPA involvement in GC and suggest that these lncRNAs might be useful as diagnostic/ prognostic biomarkers in cancer

Apical preparation size after repetitive pecking to the working length using different endodontic file systems

Aim: The purpose of this study was to determine and evaluate the apical preparation size resulting from different pecking times to the working length (WL) with five different file systems. Materials and methods: Fifty standard simulated endodontic J-shaped blocks were instrumented using ProTaper NEXT (PTN), WaveOne (WO), WaveOne Gold (WOG), OneShape (OS) and the Self-Adjusting File (SAF) (n = 10) with different pecking times (1, 2 and 4) to the WL. For the SAF group, instrumentation was done till WL according to the time, i.e. 1, 3 and 4 min. On completion of each stage, silicone impression material was used to take canal impressions for comparison and evaluation of the apical size preparation, using a stereomicroscope. Two-way analysis of variance was applied to determine differences between groups and pecking times. Results: After four pecking times, a significant increase was observed in the apical diameter of four test groups compared to SAF (P < 0.05), which was not associated with increased apical preparation at all times. Conclusion: A greater apical enlargement occurs with increasing pecking times; however, SAF instrumentation exhibits the minimum changes in the apical preparation after 1, 3 and 4 min. WO, WOG and OS are able to prepare the apical size similar to their tip at a single peck to the WL. Riassunto: Obiettivi: Lo scopo di questo studio è stato di determinare e valutare la dimensione della preparazione apicale risultante da diversi tempi di movimento alla lunghezza di lavoro con cinque diversi file system. Materiali e metodi: Cinquanta blocchetti di resina endodontici standard con canali simulati a forma di J sono stati strumentati utilizzando ProTaper NEXT (PTN), WaveOne (WO), WaveOne Gold (WOG), OneShape (OS) e Self-Adjusting File (SAF) (n = 10) con numero di movimenti all’apice diversi (uno, due e quattro). Per il gruppo SAF, la strumentazione è stata eseguita fino alla lunghezza di lavoro in base al tempo, cioè 1 minuto, 3 minuti e 4 minuti. Al completamento di ogni fase, è stato utilizzato materiale per impronte in silicone per prendere l’impronta del canale per il confronto e la valutazione della preparazione della dimensione apicale, utilizzando uno stereomicroscopio. L’analisi della varianza a due vie è stata applicata per determinare le differenze statistiche tra i gruppi e i tempi di preparazione apicale. Risultati: Dopo quattro movimenti all’apice, è stato osservato un aumento significativo nel diametro apicale nei quattro gruppi testati rispetto al SAF (p < 0,05), che non è stato associato ad un aumento della preparazione apicale in ogni momento. Conclusioni: Si è rilevato un maggiore allargamento apicale con l’aumentare del numero di movimenti eseguiti all’apice; tuttavia, la strumentazione SAF mostra dei cambiamenti minimi nella preparazione apicale dopo 1, 3 e 4 minuti. WO, WOG e OS sono in grado di preparare la dimensione apicale simile alla loro punta effettuando un singolo movimento alla lunghezza di lavoro. Keywords: Apical preparation size, Nickel–titanium, Reciprocating files, Rotary files, Self-Adjusting File, Parole chiave: Dimensione di preparazione apicale, Nichel-titanio, Strumenti reciprocanti, Strumenti rotanti, Self-adjusting fil