Search results for "modification"

Perfluorocarbons–graphene oxide nanoplatforms as biocompatible oxygen reservoirs

2018

Abstract 3-Pentadecafluoroheptyl,5-perfluorophenyl-1,2,4-oxadiazole (FOX) molecules were attached onto a graphene oxide (GO) via a facile aromatic substitution in alkaline environment. This approach allows achieving high degree of functionalization under mild conditions. The covalent attachment of perfluoromoieties onto GO lamellae was confirmed by spectroscopic analyses. The performance of these nanoplatforms (GOF) as oxygen reservoirs was assessed at different concentrations and temperature. The results revealed that under physiologic conditions GO and FOX synergistically operate for increasing oxygen uptake and release, either from a thermodynamic and a kinetic point of view. Even at low…

EPR investigations of polymeric and H2O2 -modified C3N4 -based photocatalysts

2019

The C3N4 -based nanopowders prepared by thermal condensation of melamine (MCN) with subsequent thermal etching (MCN-TE) and H2O2 -treatment were investigated by Q- and X-band EPR spectroscopy in dark and upon in situ UVA or visible-light exposure. Lorentzian signal at g = 2.003, more pronounced in the case of the thermally etched material, dominates EPR spectra of MCN and MCN-TE. More complex spectra were found for H2O2 -treated photocatalysts revealing the presence of signals attributed to the radicals produced via H2O2 interaction with C/N sites in the C3N4 polymeric network. The X-band spectra monitored upon in situ irradiation of the C3N4 -based photocatalysts evidenced the intensity gr…

Synthesis and some reactions of linear poly(iminohexamethylene)

1987

By complete reduction of polyamide-6, poly(iminohexamethylene) (PIH) was obtained. This new linear polyamine was characterized by i.r. and by n.m.r. spectroscopy as well as by titration. Differential scanning calorimetry measurements and X-ray diffraction found a high degree of crystallinity whose extent strongly depends upon the pre-treatment. The polyammonium salts that form with inorganic and organic acids show the typical polyelectrolyte effect in viscometry. PIH was alkylated with methyl iodide or acrylic acid and was acylated with N-BOC-l-α-amino acids or N-BOC-ω-amino-alkylenecarboxylic acids. The properties of these derivatives are described.

Non-small cell lung cancer (NSCLC), EGFR downstream pathway activation and TKI targeted therapies sensitivity: Effect of the plasma membrane-associat…

2017

Adenocarcinoma of Non-Small Cell Lung Cancer (NSCLC) is a severe disease. Patients carrying EGFR mutations may benefit from EGFR targeted therapies (e.g.: gefitinib). Recently, it has been shown that sialidase NEU3 directly interacts and regulates EGFR. In this work, we investigate the effect of sialidase NEU3 overexpression on EGFR pathways activation and EGFR targeted therapies sensitivity, in a series of lung cancer cell lines. NEU3 overexpression, forced after transfection, does not affect NSCLC cell viability. We demonstrate that NEU3 overexpression stimulates the ERK pathway but this activation is completely abolished by gefitinib treatment. The Akt pathway is also hyper-activated upo…

2015

Modified nucleotide 5-methylcytosine (m5C) is frequently present in various eukaryotic RNAs, including tRNAs, rRNAs and in other non-coding RNAs, as well as in mRNAs. RNA:m5C-methyltranferases (MTases) Nop2 from S. cerevisiae and human proliferation-associated nucleolar antigen p120 are both members of a protein family called Nop2/NSUN/NOL1. Protein p120 is well-known as a tumor marker which is over-expressed in various cancer tissues. Using a combination of RNA bisulfite sequencing and HPLC-MS/MS analysis, we demonstrated here that p120 displays an RNA:m5C- MTase activity, which restores m5C formation at position 2870 in domain V of 25S rRNA in a nop2Δ yeast strain. We also confirm that ye…

Histone-mediated transgenerational epigenetics

2019

Abstract Epigenetic mechanisms operate at the interface between the environment and genome, by converting the environmental stimuli to phenotypic responses through changes in the chromatin landscape, which ultimately affects gene expression in the absence of alterations in DNA sequence. In this scenario, transgenerational inheritance occurs when epigenetic variations induced by environmental stimuli are transmitted through the germ line to succeeding generations that had never experienced those stimuli. There is an ever-growing list of reports indicating that histones are fundamental players in these processes in a variety of organisms. In this chapter, we provide a perspective on histone-d…

Genetic and Cytological Analysis of Drosophila Chromatin-Remodeling Factors

2003

Histone Code and Higher-Order Chromatin Folding: A Hypothesis

2016

AbstractHistone modifications alone or in combination are thought to modulate chromatin structure and function; a concept termed histone code. By combining evidence from several studies, we investigated if the histone code can play a role in higher-order folding of chromatin. Firstly using genomic data, we analyzed associations between histone modifications at the nucleosome level. We could dissect the composition of individual nucleosomes into five predicted clusters of histone modifications. Secondly, by assembling the raw reads of histone modifications at various length scales, we noticed that the histone mark relationships that exist at nucleosome level tend to be maintained at the high…

Mobility Limitation and Changes in Personal Goals Among Older Women.

2016

Objectives. Several theoretical viewpoints suggest that older adults need to modify their personal goals in the face of functional decline. The aim of this study was to investigate longitudinally the association of mobility limitation with changes in personal goals among older women. Method. Eight-year follow-up of 205 women aged 66–78 years at baseline. Results. Health-related goals were the most common at both measurements. Goals related to independent living almost doubled and goals related to exercise and to cultural activities substantially decreased during the follow-up. Higher age decreased the likelihood for engaging in new goals related to cultural activities and disengaging from g…

Presentación. Deporte e identidad nacional: articulaciones y desconexiones en contextos postnacionales

2020

This article is the presentation of the issue on "Sport and national identity" by Papeles del CEIC. The introduction highlights the historical simultaneity in the emergence of sport and the building of modern Nation-States, as well as the role of the former in the processes of building of national identities. Next, reference is made to the transformations caused by the processes of globalization and its impact in the articulation of collective identities and sport. The dossier includes a paper that analyses the way in which the social history of football can serve to think about the national identity of Brazil; two papers that explore the challenges concerning collective identity faced by a…