64 research outputs found
The synthesis and properties of the phases obtained by solid-solid reactions
The presented work encompasses the subject of the studies and the results obtained over the last years by the research workers of the Department of Inorganic Chemistry. They include mainly the studies on the reactivity of metal oxides, searching for new phases in binary and ternary systems of metal oxides as well as describing phase relations establishing in such systems. They also encompass works on the extensive characteristics of physico-chemical properties of the newly obtained compounds
In-situ particles reorientation during magnetic hyperthermia application: Shape matters twice
OSIRIS – The scientific camera system onboard Rosetta
The Optical, Spectroscopic, and Infrared Remote Imaging System OSIRIS is the scientific camera system onboard the Rosetta spacecraft (Figure 1). The advanced high performance imaging system will be pivotal for the success of the Rosetta mission. OSIRIS will detect 67P/Churyumov-Gerasimenko from a distance of more than 106 km, characterise the comet shape and volume, its rotational state and find a suitable landing spot for Philae, the Rosetta lander. OSIRIS will observe the nucleus, its activity and surroundings down to a scale of ~2 cm px−1. The observations will begin well before the onset of cometary activity and will extend over months until the comet reaches perihelion. During the rendezvous episode of the Rosetta mission, OSIRIS will provide key information about the nature of cometary nuclei and reveal the physics of cometary activity that leads to the gas and dust coma.
OSIRIS comprises a high resolution Narrow Angle Camera (NAC) unit and a Wide Angle Camera (WAC) unit accompanied by three electronics boxes. The NAC is designed to obtain high resolution images of the surface of comet 7P/Churyumov-Gerasimenko through 12 discrete filters over the wavelength range 250–1000 nm at an angular resolution of 18.6 μrad px−1. The WAC is optimised to provide images of the near-nucleus environment in 14 discrete filters at an angular resolution of 101 μrad px−1. The two units use identical shutter, filter wheel, front door, and detector systems. They are operated by a common Data Processing Unit. The OSIRIS instrument has a total mass of 35 kg and is provided by institutes from six European countrie
Multimodal use of the porphyrin TMPyP: From cancer therapy to antimicrobial applications
The cationic porphyrin meso-tetra(4-N-methylpyridyl)porphine (TMPyP) has a high yield of singlet oxygen generation upon light activation and a strong affinity for DNA. These advantageous properties have turned it into a promising photosensitizer for use in photodynamic therapy (PDT). In this review, we have summarized the current state-of-the-art applications of TMPyP for the treatment of cancer as well as its implementation in antimicrobial PDT. The most relevant studies reporting its pharmacokinetics, subcellular localization, mechanism of action, tissue biodistribution and dosimetry are discussed. Combination strategies using TMPyP-PDT together with other photosensitizers and chemotherapeutic agents to achieve synergistic anti-tumor effects and reduce resistance to therapy are also explored. Finally, we have addressed emerging applications of this porphyrin, including nanoparticle-mediated delivery, controlled drug release, biosensing and G-quadruplex stabilization for tumor growth inhibition. Altogether, this work highlights the great potential and versatility that TMPyP can offer in different fields of biomedicine such us cancer treatment or antimicrobial therapy
Competing magnetic interactions in Zn3Fe4V6O24 studied by electron paramagnetic resonance
A multicomponent vanadate M3Fe4V6O24 sample with non-magnetic M = Zn(II)
ions was synthesized by the solid state reaction method using
stoichiometric mixtures of the 80mol% FeVO4 and 20mol% Zn-3(VO4)(2).
The temperature dependence of the EPR spectra was performed in the
90-280 K temperature range. The resonance field and the integrated
intensity of the EPR line showed minimum value of both parameters at
approximate to 200 K. It is suggested that a part of the sample is
displaying tendency to form an antiferromagnetic ordered state (or the
magnetic clusters) above this temperature while below the ferromagnetic
interaction of the main part of material is dominating. This behaviour
is attributed to the inherent magnetic inhomogeneity of the system due
to the presence of the ferromagnetic or antiferromagnetic spin clusters
Magnetic resonance study of phases in FeVO4Co3V 2O8 system
Multicomponent vanadates Co3xFe4-xV6O 24 have been synthesized using the solid state reaction method from Co3V2O8 and FeVO4.oxides. The electron paramagnetic resonance/ferromagnetic resonance (EPR/FMR) spectra of 20 samples containing solid state phases formed in the FeVO4Co 3V2O8 system have been recorded at room temperature. The howardevansite structure (H-type phase) is produced, which corresponds to the Co2.616Fe4.256V6O 24 formula while a homogeneity range of lyonsite (L-type phase) type structure could be described by the Co31.5xFe4-xV 6O24 formula (0.476<x<1.667). Considering the values of g-factor and linewidth of each registered spectrum the existence of three types of magnetic centers was inferred and correlated with phases detected by XRD method. © 2011 Elsevier B.V. All rights reserved
Competing Magnetic Interactions in ZnFeVO Studied by Electron Paramagnetic Resonance
A multicomponent vanadate MFeVO sample with non-magnetic M = Zn(II) ions was synthesized by the solid state reaction method using stoichiometric mixtures of the 80mol% FeVO and 20mol% Zn(VO). The temperature dependence of the EPR spectra was performed in the 90-280 K temperature range. The resonance field and the integrated intensity of the EPR line showed minimum value of both parameters at≈200 K. It is suggested that a part of the sample is displaying tendency to form an antiferromagnetic ordered state (or the magnetic clusters) above this temperature while below the ferromagnetic interaction of the main part of material is dominating. This behaviour is attributed to the inherent magnetic inhomogeneity of the system due to the presence of the ferromagnetic or antiferromagnetic spin clusters
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