An attempt to apply a SQUID microscope for visualization of magnetic structure in giant magnetic impedance (GMI) elements was undertaken. The measurements were carried out on the 1/spl times/10/sup ...-3/ mm thick permalloy strip with the in-plane sizes 6 mm/spl times/0.3 mm. The topography of the vertical component of magnetic field was imaged with a high spatial resolution close to 30/spl times/10/sup -3/ mm over the central part of a sample. The images taken in the applied magnetic field varied over the range /spl plusmn/4 kA/m reveal the domain structure with anisotropy perpendicular to longitudinal sample axis.
The magnetic properties of an assembly of very small Fe nanoparticles with an average diameter of the order of 3–5
nm are studied both experimentally and theoretically. The particles are dispersed in ...a polyethylene matrix with mass concentration 5%. The stray magnetic field of the samples with sizes 1×1×0.2
mm is measured by means of scanning SQUID microscope at 77
K as a function of external magnetic field. The presence of a weak remanent magnetization indicates a magnetic ordering in the samples studied at rather high temperatures. A distribution of the particle volumes or partial agglomeration of the particles within the assembly is suggested to be responsible for this unexpected behavior.
The magnetic properties of amorphous ferromagnetic 30–50-μm diameter microwires produced by means of spinning process are studied both experimentally and theoretically. The magnetic images of the ...microwire are measured at 77 K with the high-spatial resolution scanning SQUID microscope in an axial magnetic field up to 10
3 A/m. The values of the local magnetic fields produced by the microwire in remnant state are typically a few μT at a distance 50–100 μm far from the sample. It is shown that the wire's domain structure calculated numerically is in a qualitative agreement with the magnetic images obtained experimentally.
Magnetic properties of amorphous ferromagnetic wires serving as a magnetic flux guide for the high-
T
c SQUID microscope are investigated. A mathematical model of a flux guide operation was developed ...on the base of integral equation methods. It is shown that when the flux guide is used in combination with the SQUID the integral of magnetic potential along the flux guide is the main measured value. Experimental results received with the use of the scanning high-
T
c SQUID microscope for liquid-nitrogen cooled samples are in good agreement with the proposed model.
The effect of lithium hydroxybutyrate on the development of the fetus and offsprings was studied on a model of alcohol intoxication of male rats. Under such conditions lithium hydroxybutyrate ...relieved completely the negative action of alcohol on the reproductive function, according to all parameters. The learning ability of the offsprings and their behavioral disorders in a stress situation caused by alcohol were normalized. Two-week administration of 100 mg/kg lithium hydroxybutyrate had no negative effect on the embryonal and postnatal development of the offsprings.
Phenazepam, 10 mg/kg/day, or phenobarbital, 30 mg/kg/day, administered to female rats during the entire pregnancy and 5 days after delivery during lactation induced behavioral changes in their ...offsprings at early (1.5-2 months) and later (4 months) ages. Phenobarbital produced a more marked effect on the central nervous system than phenazepam by causing impairments of extrapolatory reflexes and behavioral stereotype in a conflict situation or open field.
Experiments on rats with myocardial infarction induced by occlusion of the left coronary artery were made to explore the influence of calcium antagonists injected intraperitoneally for a long time ...(daily, for 21 days) on hemodynamics, contractile function and morphology of the heart muscle. It has been shown that verapamil (0.5 mg/kg), diltiazem (2 mg/kg) and nimodipine (20 micrograms/kg) do not exert under those conditions any noticeable effect on pump and contractile heart functions. Administration of verapamil in a doze of 2 mg/kg enhanced heart failure. The drugs under study normalized the response of contractile heart function to volumetric load, which is related to a considerable measure to the acceleration of reparative processes in the myocardium.
