Structural, Optical, and Magnetic Properties of Pure and Ni-Fe-Codoped Zinc Oxide Nanoparticles Synthesized by a Sol-Gel Autocombustion Method.

Pure and Ni-Fe-codoped Zn1 - 2xNixFexO (x = 0.01, 0.02, 0.03, and 0.04) nanoparticles were effectively synthesized using a sol-gel autocombustion procedure. The structural, optical, morphological, and magnetic properties were determined by using X-ray diffraction (XRD), ultraviolet-visible (UV-vis), scanning electron microscopy, and vibrating sample magnetometer techniques. The XRD confirmed the purity of the hexagonal wurtzite crystal structure. XRD analysis further indicated that Fe and Ni successfully substituted the lattice site of Zn and generated a single-phase Zn1-2xNixFexO magnetic oxide. In addition, a significant morphological change was observed with an increase in the dopant concentration by using high-resolution scanning electron microscopy. The UV-vis spectroscopy analysis indicated the redshift in the optical band gap with increasing dopant concentration signifying a progressive decrease in the optical band gap. The vibrating sample magnetometer analysis revealed that the doped samples exhibited ferromagnetic properties at room temperature with an increase in the dopant concentration. Dopant concentration was confirmed by using energy-dispersive X-ray spectroscopy. The current results provide a vital method to improve the magnetic properties of ZnO nanoparticles, which may get significant attention from researchers in the field of magnetic semiconductors.

Neurological toxicity during metastatic melanoma treatment with fotemustine.

Fotemustine is a cytotoxic drug belonging to the group of nitrosourea derivatives, and is used in the treatment of metastatic melanoma, particularly when secondary brain lesions are present. We report the case of a female patient in partial response following 10 courses of fotemustine and featuring a rapidly progressing mental impairment. The clinical and radiological patterns were consistent with a fotemustine-related toxic encephalopathy, as described previously in a recent report. The physician should be aware of this neurological complication of fotemustine, so that it may be recognized early and not attributed erroneously to tumour evolution.