141 research outputs found
Sigma-phase in Fe-Cr and Fe-V alloy systems and its physical properties
A review is presented on physical properties of the sigma-phase in Fe-Cr and
Fe-V alloy systems as revealed both with experimental -- mostly with the
Mossbauer spectroscopy -- and theoretical methods. In particular, the following
questions relevant to the issue have been addressed: identification of sigma
and determination of its structural properties, kinetics of alpha-to-sigma and
sigma-to-alpha phase transformations, Debye temperature and Fe-partial phonon
density of states, Curie temperature and magnetization, hyperfine fields,
isomer shifts and electric field gradients.Comment: 26 pages, 23 figures and 83 reference
Evidence for Different Freeze-Out Radii of High- and Low-Energy Pions Emitted in Au+Au Collisions at 1 GeV/nucleon
Double differential production cross sections of negative and positive pions
and the number of participating protons have been measured in central Au+Au
collisions at 1 GeV per nucleon incident energy. At low pion energies the pi^-
yield is strongly enhanced over the pi^+ yield. The energy dependence of the
pi^-/pi^+ ratio is assigned to the Coulomb interaction of the charged pions
with the protons in the reaction zone. The deduced Coulomb potential increases
with increasing pion c.m. energy. This behavior indicates different freeze-out
radii for different pion energies in the c.m.~frame.Comment: IKDA is the Institute for Nuclear Physics in Darmstadt/German
Detection of sub-lattice magnetism in sigma-phase Fe-V compounds by zero-field NMR
The first successful measurements of a sub-lattice magnetism with 51V NMR
techniques in the sigma-phase Fe(100-x)Vx alloys with x = 34.4, 39.9 and 47.9
are reported. Vanadium atoms present on all five crystallographic sites are
magnetic. Their magnetic properties are characteristic of a given site, which
strongly depend on the composition. The strongest magnetism exhibit sites A and
the weakest one sites D. The estimated average magnetic moment per V atom
decreases from 0.36 muB for x = 34.4 to 0.20 muB for x = 47.9. The magnetism
revealed at V atoms is linearly correlated with the magnetic moment of Fe
atoms, which implies that the former is induced by the latter.Comment: 13 pages, 5 figure
Lipid nanocapsules loaded with gemcitabine: an innovative pharmaceutical technology for lung cancer treatment
Safe lipid nanocapsule-based gel technology to target lymph nodes and combat mediastinal metastases from an orthotopic non-small-cell lung cancer model in SCID-CB17 mice
The purpose of this study is the assessment of gel technology based on a lauroyl derivative of gemcitabine encapsulated in lipid nanocapsules delivered subcutaneously or intravenously after dilution to
target lymph nodes,
induce less systemic toxicity and
combat mediastinal metastases from an orthotopic model of human, squamous, non-small-cell lung cancer Ma44-3 cells implanted in severe combined immunodeficiency mice.
The gel technology mainly targeted lymph nodes as revealed by the biodistribution study. Moreover, the gel technology induced no significant myelosuppression (platelet count) in comparison with the control saline group, unlike the conventional intravenous gemcitabine hydrochloride treated group (PÂ <Â 0.05). Besides, the gel technology, delivered subcutaneously twice a week, was able to combat locally mediastinal metastases from the orthotopic lung tumor and to significantly delay death (PÂ <Â 0.05) as was the diluted gel technology delivered intravenously three times a week
Adenosine A2A receptors in Parkinson’s disease treatment
Latest results on the action of adenosine A2A receptor antagonists indicate their potential therapeutic usefulness in the treatment of Parkinson’s disease. Basal ganglia possess high levels of adenosine A2A receptors, mainly on the external surfaces of neurons located at the indirect tracts between the striatum, globus pallidus, and substantia nigra. Experiments with animal models of Parkinson’s disease indicate that adenosine A2A receptors are strongly involved in the regulation of the central nervous system. Co-localization of adenosine A2A and dopaminergic D2 receptors in striatum creates a milieu for antagonistic interaction between adenosine and dopamine. The experimental data prove that the best improvement of mobility in patients with Parkinson’s disease could be achieved with simultaneous activation of dopaminergic D2 receptors and inhibition of adenosine A2A receptors. In animal models of Parkinson’s disease, the use of selective antagonists of adenosine A2A receptors, such as istradefylline, led to the reversibility of movement dysfunction. These compounds might improve mobility during both monotherapy and co-administration with L-DOPA and dopamine receptor agonists. The use of adenosine A2A receptor antagonists in combination therapy enables the reduction of the L-DOPA doses, as well as a reduction of side effects. In combination therapy, the adenosine A2A receptor antagonists might be used in both moderate and advanced stages of Parkinson’s disease. The long-lasting administration of adenosine A2A receptor antagonists does not decrease the patient response and does not cause side effects typical of L-DOPA therapy. It was demonstrated in various animal models that inhibition of adenosine A2A receptors not only decreases the movement disturbance, but also reveals a neuroprotective activity, which might impede or stop the progression of the disease. Recently, clinical trials were completed on the use of istradefylline (KW-6002), an inhibitor of adenosine A2A receptors, as an anti-Parkinson drug
Hydrolytic and redox transformations of chromium(III) bis-oxalato complexes with glutaminic acid and glutamine: a kinetic, UV–Vis and EPR, study
Changes in soluble carbohydrates in polar Caryophyllaceae and Poaceae plants in response to chilling
Global existence and boundedness in a quasilinear attraction-repulsion chemotaxis system of parabolic-elliptic type
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