Micro/nano-patterns for enhancing differentiation of human neural stem cells and fabrication of nerve conduits via soft lithography and 3D printing.

Topographical cues on materials can manipulate cellular fate, particularly for neural cells that respond well to such cues. Utilizing biomaterial surfaces with topographical features can effectively influence neuronal differentiation and promote neurite outgrowth. This is crucial for improving the regeneration of damaged neural tissue after injury.

A New Method to Prepare Stable Polyaniline Dispersions for Highly Loaded Cathodes of All-Polymer Li-Ion Batteries.

A new method for the preparation of polyaniline (PANI) films that have a 2D structure and can record high active mass loading (up to 30 mg cm) via acid-assisted polymerization in the presence of concentrated formic acid was developed. This new approach represents a simple reaction pathway that proceeds quickly at room temperature in quantitative isolated yield with the absence of any byproducts and leads to the formation of a stable suspension that can be stored for a prolonged time without sedimentation. The observed stability was explained by two factors: (a) the small size of the obtained rod-like particles (50 nm) and (b) the change of the surface of colloidal PANI particles to a positively charged form by protonation with concentrated formic acid.

Electron Spin Relaxation in Carbon Materials.

This article focuses on EPR relaxation measurements in various carbon samples, e.g., natural carbons-anthracite, coal, higher anthraxolites, graphite; synthetically obtained carbons-glassy carbons, fullerenes, graphene, graphene oxide, reduced graphene oxide, graphite monocrystals, HOPG, nanoribbons, diamonds.

Electron Spin Relaxation Studies of Polydopamine Radicals.

We present a thoroughgoing electron paramagnetic resonance investigation of polydopamine (PDA) radicals using multiple electron paramagnetic resonance techniques at the W-band (94 GHz), electron nuclear double resonance at the Q-band (34 GHz), spin relaxation, and continuous wave measurements at the X-band (9 GHz). The analysis proves the existence of two distinct paramagnetic species in the PDA structure. One of the two radical species is characterized by a long spin-lattice T relaxation time equal to 46.

Unique cellular network formation guided by heterostructures based on reduced graphene oxide - TiCT MXene hydrogels.

Two-dimensional (2D) materials remain highly interesting for assembling three-dimensional (3D) structures, amongst others, in the form of macroscopic hydrogels. Herein, we present a novel approach for inducing chemical inter-sheet crosslinks via an ethylenediamine mediated reaction between TiCT and graphene oxide in order to obtain a reduced graphene oxide-MXene (rGO-MXene) hydrogel. The composite hydrogels are hydrophilic with a stiffness of ~20 kPa.

Tuning Properties of Partially Reduced Graphene Oxide Fibers upon Calcium Doping.

The arrangement of two-dimensional graphene oxide sheets has been shown to influence physico-chemical properties of the final bulk structures. In particular, various graphene oxide microfibers remain of high interest in electronic applications due to their wire-like thin shapes and the ease of hydrothermal fabrication. In this research, we induced the internal ordering of graphene oxide flakes during typical hydrothermal fabrication via doping with Calcium ions (~6 wt.

Unraveling Origins of EPR Spectrum in Graphene Oxide Quantum Dots.

Carbon nanostructures are utilized in a plethora of applications ranging from biomedicine to electronics. Particularly interesting are carbon nanostructured quantum dots that can be simultaneously used for bimodal therapies with both targeting and imaging capabilities. Here, magnetic and optical properties of graphene oxide quantum dots (GOQDs) prepared by the top-down technique from graphene oxide and obtained using the Hummers' method were studied.

Fabricating versatile cell supports from nano- and micro-sized graphene oxide flakes.

Micro-sized structures made from graphene oxide (GO) attract high interest for their extensive use in tissue engineering. The fabrication and cytotoxicity of 3D graphene-based scaffolds so far have not been extensively discussed with relation to the flake sizes used. In this work we considered GO flakes of two different lognormal size distributions (GO: 4.

The Influence of Oxygen Concentration during MAX Phases (Ti₃AlC₂) Preparation on the α-Al₂O₃ Microparticles Content and Specific Surface Area of Multilayered MXenes (Ti₃C₂T).

The high specific surface area of multilayered two-dimensional carbides called MXenes, is a critical feature for their use in energy storage systems, especially supercapacitors. Therefore, the possibility of controlling this parameter is highly desired. This work presents the results of the influence of oxygen concentration during Ti₃AlC₂ ternary carbide-MAX phase preparation on α-Al₂O₃ particles content, and thus the porosity and specific surface area of the Ti₃C₂T MXenes.

Biomedical Applications of Graphene-Based Structures.

Graphene and graphene oxide (GO) structures and their reduced forms, e.g., GO paper and partially or fully reduced three-dimensional (3D) aerogels, are at the forefront of materials design for extensive biomedical applications that allow for the proliferation and differentiation/maturation of cells, drug delivery, and anticancer therapies.

EPR Oximetry Sensor-Developing a TAM Derivative for In Vivo Studies.

Oxygenation is one of the most important physiological parameters of biological systems. Low oxygen concentration (hypoxia) is associated with various pathophysiological processes in different organs. Hypoxia is of special importance in tumor therapy, causing poor response to treatment.

Electron magnetic resonance data on high-spin Mn(III; S=2) ions in porphyrinic and salen complexes modeled by microscopic spin Hamiltonian approach.

The spin Hamiltonian (SH) parameters experimentally determined by EMR (EPR) may be corroborated or otherwise using various theoretical modeling approaches. To this end semiempirical modeling is carried out for high-spin (S=2) manganese (III) 3d ions in complex of tetraphenylporphyrinato manganese (III) chloride (MnTPPCl). This modeling utilizes the microscopic spin Hamiltonians (MSH) approach developed for the 3d and 3d ions with spin S=2 at orthorhombic and tetragonal symmetry sites in crystals, which exhibit an orbital singlet ground state.

Effect of Rabi splitting on the low-temperature electron paramagnetic resonance signal of anthracite.

Specific distortions of the EPR signal of bulk anthracite are observed at low temperatures. They are accompanied by variations in the microwave oscillator frequency and are explained by the manifestation of the Rabi splitting due to the strong coupling between electron spins and the cavity, combined with the use of an automatic frequency-control (AFC) system. EPR signals are recorded at negligible saturation in the temperature range of 4-300K with use of the AFC system to keep the oscillator frequency locked to the resonant frequency of the TM110 cylinder cavity loaded with the sample.

Size effects in the conduction electron spin resonance of anthracite and higher anthraxolite.

Electron paramagnetic resonance spectroscopy of conduction electrons, i.e. Conduction Electron Spin Resonance (CESR), is a powerful tool for studies of carbon samples.

Overmodulation of projections as signal-to-noise enhancement method in EPR imaging.

A study concerning the image quality in electron paramagnetic resonance imaging in two-dimensional spatial experiments is presented. The aim of the measurements was to improve the signal-to-noise ratio (SNR) of the projections and the reconstructed image by applying modulation amplitude higher than the radical electron paramagnetic resonance linewidth. Data were gathered by applying four constant modulation amplitudes, where one was below 1/3 (Amod  = 0.

Electron Paramagnetic Resonance Imaging and Spectroscopy of Polydopamine Radicals.

A thorough investigation of biomimetic polydopamine (PDA) by Electron Paramagnetic Resonance (EPR) is shown. In addition, temperature dependent spectroscopic EPR data are presented in the range 3.8-300 K.

Electronic structure and dynamics of low symmetry Cu2+ complexes in kainite-type crystal KZnClSO4.3H2O: EPR and ESE studies.

EPR measurements at X-band were performed in the temperature range 4.2-300 K with angular dependence measurements at 77 K for Cu(2+) in KZnClSO(4).3H(2)O.