29 research outputs found
Synthesis, structural and magnetic properties of TM22+[MOIV(CN)(8)]center dot nH(2)O
Octacyanomolybdates (OCMs) TM2 divided by[Mo(CN)(8)]center dot nHO, where TM is Mn, Fe, Co, Ni, Cu were synthesised and characterised by IR spectroscopy and UV-VIS spectroscopy. The UV-VIS spectrum showed the intervalence charge transfer (IVCT) band between Mo-IV-CN-Cu-II and Mo-V-CN-Cu-I around 510 nm. Studied OCMs adopt tetragonal crystal structure. The H-1 NMR signals reflect the magnetic moment of the TM2- ions (mu(P)). The decay rates of free induction decay (FID) signals
increase as pp and the applied static rf-field increases. The
spin-lattice relaxation times at 27.7 MHz vary from 0.0187 ins (Mn) up to 0.45 ms (Cu). Magnetization measurements indicate long-range magnetic ordering of Mn- and Co- OCMs with the Curie temperature T-c = 4 K. The remaining OCMs (TM is Fe, Ni, Cu) are paramagnetic down to T = 1.9 K
H-1 NMR on (NixMn1-x)(3)[Cr(Cn)(6)](2) center dot NH(2)O
We report on H-1 NMR of (NixMn1-x)(3)[Cr(Cn)(6)](2) center dot nH(2)O
hexacyanochromates, where x changes from 0 to 1. The decay time
constants of the free induction decay signals described by an effective
spin-spin relaxation time T-2eff obtained from M(t) = M-0 exp(t/T-2eff)
decrease as the local magnetic moments increase produced by the
magnetic transition metal ions at the sites of the resonant H-1 nuclei.
The recovery of the magnetization in the spin-lattice relaxation time
(T-1) experiments was single-exponential
Stromal cell-derived factor and granulocyte-monocyte colony-stimulating factor form a combined neovasculogenic therapy for ischemic cardiomyopathy
ObjectiveIschemic heart failure is an increasingly prevalent global health concern with major morbidity and mortality. Currently, therapies are limited, and novel revascularization methods might have a role. This study examined enhancing endogenous myocardial revascularization by expanding bone marrow-derived endothelial progenitor cells with the marrow stimulant granulocyte-monocyte colony-stimulating factor and recruiting the endothelial progenitor cells with intramyocardial administration of the potent endothelial progenitor cell chemokine stromal cell-derived factor.MethodsIschemic cardiomyopathy was induced in Lewis rats (n = 40) through left anterior descending coronary artery ligation. After 3 weeks, animals were randomized into 4 groups: saline control, granulocyte-monocyte colony-stimulating factor only (GM-CSF only), stromal cell-derived factor only (SDF only), and combined stromal cell-derived factor/granulocyte-monocyte colony-stimulating factor (SDF/GM-CSF) (n = 10 each). After another 3 weeks, hearts were analyzed for endothelial progenitor cell density by endothelial progenitor cell marker colocalization immunohistochemistry, vasculogenesis by von Willebrand immunohistochemistry, ventricular geometry by hematoxylin-and-eosin microscopy, and in vivo myocardial function with an intracavitary pressure-volume conductance microcatheter.ResultsThe saline control, GM-CSF only, and SDF only groups were equivalent. Compared with the saline control group, animals in the SDF/GM-CSF group exhibited increased endothelial progenitor cell density (21.7 ± 3.2 vs 9.6 ± 3.1 CD34+/vascular endothelial growth factor receptor 2–positive cells per high-power field, P = .01). There was enhanced vascularity (44.1 ± 5.5 versus 23.8 ± 2.2 von Willebrand factor-positive vessels per high-power field, P = .007). SDF/GM-CSF group animals experienced less adverse ventricular remodeling, as manifested by less cavitary dilatation (9.8 ± 0.1 mm vs 10.1 ± 0.1 mm [control], P = .04) and increased border-zone wall thickness (1.78 ± 0.19 vs 1.41 ± 0.16 mm [control], P = .03). (SDF/GM-CSF group animals had improved cardiac function compared with animals in the saline control group (maximum pressure: 93.9 ± 3.2 vs 71.7 ± 3.1 mm Hg, P < .001; maximum dP/dt: 3513 ± 303 vs 2602 ± 201 mm Hg/s, P < .05; cardiac output: 21.3 ± 2.7 vs 13.3 ± 1.3 mL/min, P < .01; end-systolic pressure-volume relationship slope: 1.7 ± 0.4 vs 0.5 ± 0.2 mm Hg/μL, P < .01.)ConclusionThis novel revascularization strategy of bone marrow stimulation and intramyocardial delivery of the endothelial progenitor cell chemokine stromal cell-derived factor yielded significantly enhanced myocardial endothelial progenitor cell density, vasculogenesis, geometric preservation, and contractility in a model of ischemic cardiomyopathy
Low field magnetic susceptibility of amorphous CoxPd80−xSi20 and FexPd80−xSi20 alloys in the vicinity of the magnetic transition temperature
The Magnetic Properties and the Barkhausen Noise of the Annealed Fe-V-B Amorphous Alloy
As a consequence of the annealing process, the study of structural changes which can be followed by measuring structure sensitive magnetic properties as the stress induced anisotropy, the coercive force, the demagnetizing factor, and the Barkhausen noise parameters of the as-cast and annealed FeVB amorphous alloys was performed. The structural changes were connected with the temperature range where the FeVB amorphous alloy was characterized by the soft magnetic properties
MAGNETIC PROPERTIES OF AMORPHOUS Ni-Pd-Si ALLOYS.
La substitution partielle du palladium par des éléments possédant des électrons 3d tels que Fe, Co ou Ni change profondément les propriétés magnétiques de l'alliage amorphe Pd-Si. Nous avons étudié systématiquement la susceptibilité magnétique des alliages amorphes (NixPd100-x)83Si17 en fonction de la température (4,2 < T < 580 K) et de la concentration (5 < x < 50). On discute brièvement de résultats obtenus.The magnetic properties of amorphous Pd - Si alloys are significantly changed by partly substituting the Pd with 3d elements such as Fe, Co and Ni. The low-field magnetic susceptibility of amorphous (NixPd100-x)83Si17 alloys was systematically investigated as a function of temperature (4.2 < T < 580 K) and concentration (5 < x < 50). We briefly discuss the obtained data
Influence of neutron irradiation on hardness and fracture strength of the amorphous alloy Ni 40
Magnetic Properties of Thorium Ferricyanide
The magnetic properties of Th[Fe(CN)]·10HO were investigated. It was shown that this compound is antiferromagnetically ordered in the low temperature region. The observed antiferromagnetic ordering is stable only in the low field
Effects of alloying and pressure on magnetic properties of itinerant intermetallic compound UFe₂
The ferromagnetic state of the itinerant compound UFe₂ correlated with a peak in the density of states at the Fermi level is well known to be strongly suppressed by replacing Fe with other 3d elements. To separate the effect of change in filling of the band from that of its deformation under alloying, the magnetic susceptibility of both quasi-binary alloys U(Fe₁₋ₓMeₓ)₂ (Me = Mn, Co) with a varying number of valence electrons and isoelectronic quasi-ternary alloys U(Fe₁₋ₓTₓ)₂, U(Fe₀.₉₋ₓMn₀.₁Tₓ)₂ and U(Fe₀.₉₋ₓCo₀.₁Tₓ)₂ (T = Mn₀.₅Co₀.₅) was studied in the temperature range 4.2 K £ T£300 K. Both the effects were found to play important roles in suppression of the ferromagnetic state in UFe₂ -based alloys. In addition, the magnetic susceptibility of U(Fe₁₋ₓMnₓ)₂ and U(Fe₁₋ₓTₓ)₂ alloys and UCo₂ compound have been studied under pressure up to 4 kbar at T = 78 and 293 K. The volume dependence of the exchange enhancement in spin paramagnetism of the UFe₂ compound and its alloys has been derived from analysis of the pressure effects in the framework of the Stoner model