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1.
Chem Commun (Camb) ; 58(93): 13015-13018, 2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36341972

RESUMO

In this paper, efficient MMA photo O-ATRP protocols conducted inside nanoreactors varying in nanostructured interfaces are reported for the first time. We showed that the microstructure of recovered polymers could be easily tuned just by implementing a given type of nanochannel (d = 10, 19-28, 35, 160 nm).

2.
Materials (Basel) ; 15(3)2022 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-35160787

RESUMO

Investigated the structural, electronic, and magnetic properties of copper pyrophosphate dihydrate (CuPPD) by the first-principle calculations based on the density functional theory (DFT). Simulations were performed with the generalized gradient approximation (GGA) of the exchange-correlation functional (Exc) supplemented by an on-site Coulomb self-interaction (U-Hubbard term). It was confirmed that the GGA method did not provide a satisfactory result in predicting the electronic energy band gap width (Eg) of the CuPPD crystals. Simultaneously, we measured the Eg of CuPPD nanocrystal placed inside mesoporous silica using the ultraviolet-visible spectroscopy (UV-VIS) technique. The proposed Hubbard correction for Cu-3d and O-2p states at U = 4.64 eV reproduces the experimental value of Eg = 2.34 eV. The electronic properties presented in this study and the results of UV-VIS investigations likely identify the semiconductor character of CuPPD crystal, which raises the prospect of using it as a component determining functional properties of nanomaterials, including quantum dots.

3.
Materials (Basel) ; 13(14)2020 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-32668572

RESUMO

The impact of europium doping on the electronic and structural properties of the topological insulator Bi2Te3 is studied in this paper. The crystallographic structure studied by electron diffraction and transmission microscopy confirms that grown by Molecular Beam Epitaxy (MBE) system film with the Eu content of about 3% has a trigonal structure with relatively large monocrystalline grains. The X-ray photoemission spectroscopy indicates that europium in Bi2Te3 matrix remains divalent and substitutes bismuth in a Bi2Te3 matrix. An exceptional ratio of the photoemission 4d multiplet components in Eu doped film was observed. However, some spatial inhomogeneity at the nanometer scale is revealed. Firstly, local conductivity measurements indicate that the surface conductivity is inhomogeneous and is correlated with a topographic image revealing possible coexistence of conducting surface states with insulating regions. Secondly, Time of Flight Secondary Ion Mass Spectrometry (TOF-SIMS) depth-profiling also shows partial chemical segregation. Such in-depth inhomogeneity has an impact on the lattice dynamics (phonon lifetime) evaluated by femtosecond spectroscopy. This unprecedented set of experimental investigations provides important insights for optimizing the process of growth of high-quality Eu-doped thin films of a Bi2Te3 topological insulator. Understanding such complex behaviors at the nanoscale level is a necessary step before considering topological insulator thin films as a component of innovative devices.

4.
Nano Lett ; 20(8): 5714-5719, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32559092

RESUMO

Herein we show that the nanostructured interface obtained via modulation of the pore size has a strong impact on the segmental and chain dynamics of two poly(propylene glycol) (PPG) derivatives with various molecular weights (Mn = 4000 g/mol and Mn = 2000 g/mol). In fact, a significant acceleration of the dynamics was observed for PPG infiltrated into ordinary alumina templates (Dp = 36 nm), while bulklike behavior was found for samples incorporated into membranes of modulated diameter (19 nm < Dp < 28 nm). We demostrated that the modulation-induced roughness reduces surface interactions of polymer chains near the interface with respect to the ones adsorbed to the ordinary nanochannels. Interestingly, this effect is noted despite the enhanced wettability of PPG in the latter system. Consequently, as a result of weaker H-bonding surface interactions, the conformation of segments seems to locally mimic the bulk arrangement, leading to bulklike dynamics, highlighting the crucial impact of the interface on the overall behavior of confined materials.

5.
Sci Rep ; 10(1): 260, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31937861

RESUMO

The water-soluble glycofullerenes GF1 and GF2 were synthesized using two-step modified Bingel-Hirsch methodology. Interestingly, we identified buckyballs as a novel class of non-receptor Src kinases inhibitors. The evaluated compounds were found to inhibit Fyn A and BTK proteins with IC50 values in the low micromolar range, with the most active compound at 39 µM. Moreover, we have demonstrated that formation of protein corona on the surface of [60]fullerene derivatives is changing the landscape of their activity, tuning the selectivity of obtained carbon nanomaterials towards Fyn A and BTK kinases. The performed molecular biology studies revealed no cytotoxicity and no influence of engineered carbon nanomaterials on the cell cycle of PANC-1 and AsPC-1 cancer cell lines. Incubation with the tested compounds resulted in the cellular redox imbalance triggering the repair systems and influenced the changing of protein levels.


Assuntos
Tirosina Quinase da Agamaglobulinemia/metabolismo , Fulerenos/química , Inibidores de Proteínas Quinases/metabolismo , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Autofagia/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Fulerenos/metabolismo , Fulerenos/farmacologia , Fulerenos/uso terapêutico , Heme Oxigenase-1/metabolismo , Humanos , Oxirredução , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Coroa de Proteína/química , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas c-fyn/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Propriedades de Superfície , Proteína Supressora de Tumor p53/metabolismo
6.
J Radioanal Nucl Chem ; 317(1): 261-268, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29950748

RESUMO

Gamma irradiation studies of (Mg0.905Fe0.095)2SiO4 olivine were performed using X-ray fluorescence method, X-ray diffraction, Raman and Mössbauer spectroscopy. The absorbed doses were 300, 600 and 1000 Gy. Small irradiation doses cause an increase of lattice vibrations and small deformation of both M1 and M2 octahedron. The observed effect is similar to the results expose to high temperature. However, the small deformation takes place only in unit cell of Olivine's structure.

7.
Nanoscale ; 9(33): 12110-12123, 2017 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-28800139

RESUMO

The article is about a novel material for application in optoelectronic devices: mesoporous silica in the form of thin films with vertically aligned channels containing anchored propyl-copper-phosphonate functional groups. We described a synthesis route and carried out characterization of the structure to obtain its nonlinear optical (NLO) properties (second and third order harmonic generation). A quasi phase transition was found in the material resulting from modification of the functional group content. We also demonstrated that it is possible to modify NLO susceptibilities by tuning the distance between active polar units.

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