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S M Yusuf

Publications and source records attributed to S M Yusuf.

At least 19 recordsLinked to original sources
PubMed2005

Magnetite nanoparticles with tunable gold or silver shell.

Fe3O4 nanoparticles with size approximately 13 nm have been prepared successfully in aqueous micellar medium at approximately 80 degrees C. To make Fe3O4 nanoparticles resistant to surface poisoning a new route is developed for coating Fe3O4 nanoparticles with noble metals such as gold or silver as shell. The shell thickness of the core-shell particles becomes tunable through the adjustment of the ratio of the constituents. Thus, the route yields well-defined core-shell structures of size from 18 to 30 nm with varying proportion of Fe3O4 to the noble metal precursor salts. These magnetic nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), FTIR, differential scanning calorimetry (DSC), Raman and temperature-dependent magnetic studies.

Journal Article↗
PubMed2003

Wet chemical method for synthesis of superparamagnetic alloyed Ni--Pd and Ni--Pt nanomagnets in micelles.

The evolution of sphere- and rod-shaped superparamagnetic Ni--Pd and Ni--Pt nanoparticles by wet chemical methods is reported. It has been shown that increased CTAB (cetyltrimethylammonium bromide) concentration at room temperature promotes the formation of a higher proportion of rod-shaped nanomagnets over spherical particles. Temperature-dependent magnetic properties, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and electron dispersive X-ray (EDX) studies reveal the superparamagnetic behavior, size distribution, and percentage composition of the alloyed structures.

Journal Article↗
PubMed1979

Effects of noradrenaline and metaraminol on isolated aortic strips and auricles obtained from untreated and reserpine-treated rabbits.

The isolated aortic strips of the untreated rabbits responded to noradrenaline in concentrations ranging from 20 to 160 ng/mL, whereas similar preparations from reserpine-treated animals responded to lower concentrations (from 2.5 to 10 ng/mL) and larger effects were produced by concentrations ranging from 20 to 160 ng/mL. Comparatively stronger concentrations (from 0.4 to 1.6 microgram/mL) of metaraminol were required to produce suitable contractile responses, which were not modified by reserpine pretreatment. On the isolated auricles obtained from untreated rabbits, noradrenaline was used in concentrations of 20 and 80 ng/mL, but these concentrations were reduced to 2.5 and 10 ngmL in the case of tissues obtained from reserpinized rabbits. Comparatively stronger (0.2 and 0.8 microgram/mL) concentrations of metaraminol were required to produce a stimulant effect on this preparation, and the sensitivity was not altered by reserpine pretreatment. These observations lead to the conclusions that though reserpine pretreatment produces a well-marked increase in the sensitivity of isolated rabbit aortic strips and auricles to noradrenaline, it does not modify the sensitivity of these preparations to metaraminol. Reserpine was used in 0.3 mg/kg doses injected subcutaneously for 3 successive days.

Animals↗