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Tomasz Strączek

Bio: Tomasz Strączek is an academic researcher from AGH University of Science and Technology. The author has contributed to research in topics: Nanoparticle & Superparamagnetism. The author has an hindex of 7, co-authored 16 publications receiving 211 citations.

Papers
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Journal ArticleDOI
TL;DR: The obtained materials can be considered as highly effective contrast agents for low-field MRI, particularly useful at permanent magnet-based scanners.
Abstract: Dual-mode MRI contrast agents consisting of superparamagnetic iron oxide nanoparticle (SPION) cores and gadolinium ions associated with the ionic chitosan protecting layer were synthesized and studied. Gadolinium ions were introduced into the coating layer via direct complex formation on the nanoparticles surface, covalent attachment or electrostatically driven deposition of the preformed Gd complex. The modified SPIONs having hydrodynamic diameters ca. 100 nm form stable, well-defined dispersions in water and have excellent magnetic properties. Physiochemical properties of those new materials were characterized using e.g., FTIR spectroscopy, dynamic light scattering, X-ray fluorescence, TEM, and vibrating sample magnetometry. They behave as superparamagnetics and shorten both T1 and T2 proton relaxation times, thus influencing both r1 and r2 relaxivity values that reach 53.7 and 375.5 mM−1 s−1, respectively, at 15 MHz. The obtained materials can be considered as highly effective contrast agents for low-field MRI, particularly useful at permanent magnet-based scanners.

102 citations

Journal ArticleDOI
TL;DR: X-ray absorption spectroscopy data analysis in the near edge region (XANES) confirmed that selenium in the Se-polysaccharides structure is present at the -II oxidation state and that Se is organically bound and simulation analysis suggested that seenium is most likely bound by a glycosidic-link in a β-1,3 or α- 1,4-glycosidics bond or substituted for oxygen in a pyranosidic ring

46 citations

Journal ArticleDOI
TL;DR: In this article, a layered double hydroxide (LDH) with Mg:Al molar ratio of 2:1 synthesized using co-precipitation method was impregnated with iron oxide particles (10 and 25% loading).

35 citations

Journal ArticleDOI
18 Sep 2020
TL;DR: Single-phase multicomponent perovskite-type cobalt oxide containing five cations in equiatomic amounts on the A-site, namely, CoO3, has been synthesized via the modified coprecipitation hydrothermal method and exhibits weak ferromagnetism at T ≤ 10 K and signatures of antiferromagnetic correlations in the paramagnetic phase.
Abstract: Single-phase multicomponent perovskite-type cobalt oxide containing five cations in equiatomic amounts on the A-site, namely, (Gd0.2Nd0.2La0.2Sm0.2Y0.2)CoO3, has been synthesized via the modified c...

33 citations

Journal ArticleDOI
TL;DR: In this paper, the results revealed the formation of inner-sphere complexes between As and composites surface as well as As(V) reduction coupled with Fe(II) oxidation as the main removal mechanisms.

25 citations


Cited by
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01 Jan 1912

1,225 citations

Journal ArticleDOI
TL;DR: The synthesis, surface functionalization and characterization of iron oxide nanoparticles, as well as their (pre‐) clinical use in diagnostic, therapeutic and theranostic settings, are summarized.

618 citations

Journal ArticleDOI
TL;DR: The main goal of this paper is to present the basic properties of SPIONs, to discuss their current role in medicine, and to review their applications in order to inspire future developments of new, improved SPION systems.
Abstract: The recent, fast development of nanotechnology is reflected in the medical sciences. Superparamagnetic Iron Oxide Nanoparticles (SPIONs) are an excellent example. Thanks to their superparamagnetic properties, SPIONs have found application in Magnetic Resonance Imaging (MRI) and magnetic hyperthermia. Unlike bulk iron, SPIONs do not have remnant magnetization in the absence of the external magnetic field; therefore, a precise remote control over their action is possible. This makes them also useful as a component of the advanced drug delivery systems. Due to their easy synthesis, biocompatibility, multifunctionality, and possibility of further surface modification with various chemical agents, SPIONs could support many fields of medicine. SPIONs have also some disadvantages, such as their high uptake by macrophages. Nevertheless, based on the ongoing studies, they seem to be very promising in oncological therapy (especially in the brain, breast, prostate, and pancreatic tumors). The main goal of our paper is, therefore, to present the basic properties of SPIONs, to discuss their current role in medicine, and to review their applications in order to inspire future developments of new, improved SPION systems.

309 citations

Journal Article
TL;DR: In this article, an angle-resolved photoemission spectroscopy study of detwinned single crystals of a representative family of electron-doped iron-arsenide superconductors, Ba(Fe1-xCox)2As2 in the underdoped region was performed.
Abstract: Nematicity, defined as broken rotational symmetry, has recently been observed in competing phases proximate to the superconducting phase in the cuprate high-temperature superconductors. Similarly, the new iron-based high-temperature superconductors exhibit a tetragonal-to-orthorhombic structural transition (i.e., a broken C4 symmetry) that either precedes or is coincident with a collinear spin density wave (SDW) transition in undoped parent compounds, and superconductivity arises when both transitions are suppressed via doping. Evidence for strong in-plane anisotropy in the SDW state in this family of compounds has been reported by neutron scattering, scanning tunneling microscopy, and transport measurements. Here, we present an angle-resolved photoemission spectroscopy study of detwinned single crystals of a representative family of electron-doped iron-arsenide superconductors, Ba(Fe1-xCox)2As2 in the underdoped region. The crystals were detwinned via application of in-plane uniaxial stress, enabling measurements of single domain electronic structure in the orthorhombic state. At low temperatures, our results clearly demonstrate an in-plane electronic anisotropy characterized by a large energy splitting of two orthogonal bands with dominant dxz and dyz character, which is consistent with anisotropy observed by other probes. For compositions x > 0, for which the structural transition (TS) precedes the magnetic transition (TSDW), an anisotropic splitting is observed to develop above TSDW, indicating that it is specifically associated with TS. For unstressed crystals, the band splitting is observed close to TS, whereas for stressed crystals, the splitting is observed to considerably higher temperatures, revealing the presence of a surprisingly large in-plane nematic susceptibility in the electronic structure.

280 citations