Intriguing structural and magnetic properties correlation study on Fe3+-substituted calcium-copper-titanate.

This communication presents a detailed study on a Fe3+ modified CaCu3Ti4O12 cubic perovskite system (CaCu3-xTi4-xFe2xO12 with x = 0.0-0.7) by performing X-ray powder diffractometry, DC SQUID magnetization and 57Fe Mössbauer spectroscopy. The first ever Mössbauer studies on the system supported the reported peculiarity of the structure. Mössbauer analysis for the compositions x = 0.1, 0.3, and 0.5 suggest Fe3+ ions in two different environments. The site with larger quadrupole splitting corresponds to Fe3+ in the octahedral symmetry, while the site with lower chemical shift and quadrupole splitting belongs to Fe3+ in the square-planar (A'-) configuration. With the increase in Fe-substitution, Fe3+ appears to prefer A'- symmetry. Antiferromagnetic features are retained up to x = 0.3, but weak ferromagnetic characteristics appear with higher Fe3+ substitution. The switching of antiferromagnetic to ferromagnetic behavior was related to the preferential occupation of Fe3+ in square-planar symmetry accommodating Cu2+.

Infrared spectroscopy and elastic properties of nanocrystalline Mg-Mn ferrites prepared by co-precipitation technique.

Nanoparticles having particle size in the range 25-40 nm for compositions x = 0.0, 0.2, 0.4 and 0.5 of Mg(x)Mn(1-x)Fe2O4 spinel ferrite system have been prepared by chemical co-precipitation route. The microstructure, infrared spectral and elastic properties have been studied by means of energy dispersive analysis of X-rays (EDAX), transmission electron microscopy (TEM), X-ray diffraction (XRD) and infrared spectroscopic (IR) measurements, before (W) and after high temperature annealing A(w). The force constants for tetrahedral and octahedral sites determined by infrared spectral analysis, lattice constant and X-ray density values by X-ray diffraction pattern analysis; have been used to calculate elastic constants. The magnitude of force constant and elastic moduli for nanocrystalline W-samples are found to be larger as compared to coarse grained A(w)-samples. The results have been explained in the light of redistribution of cations and as a result change in mean ionic charge for such cationic sites, elastic energy and grain size reduction effect of Nanoparticles.

Renal involvement in leprosy.

Renal involvement was studied in 70 patients with leprosy by urine analysis, detailed biochemical investigations and renal histopathology. Of these 70 patients, 40 had lepromatous and 30 had non-lepromatous leprosy. Creatinine clearance was reduced in 20 patients. Renal biopsies were studied in 50 cases (25 lepromatous, 25 non-lepromatous); of which in 13 cases (10 lepromatous, 3 non-lepromatous) abnormal histopathological lesions were found by light microscopy. Amyloidosis was seen in only one lepromatous patient. No acid-fast bacilli and leproma like lesion were demonstrated in any case.

Indirect inguinal hernia in CAPD patients with polycystic kidney disease.

We have experienced a high incidence of indirect inguinal hernias occurring in the first few months of starting CAPD in male patients with autosomal dominant polycystic kidney disease (PKD). Out of 13 patients with P.C.K. on CAPD one (7.7%) had inguinal herniorraphy at an early age and six (46.2%) developed bilateral indirect inguinal hernia during CAPD. In comparison only one of 30 other male patients on CAPD developed indirect inguinal hernia and none had any evidence of previous inguinal herniorrhaphy or of indirect inguinal hernia on clinical examination. Five out of seventeen (29.4%) male patients with P.C.K. on hemodialysis or conservative treatment of renal impairment had history of inguinal herniorrhaphy or an evidence of inguinal hernia on clinical examination. This compares with a rate of herniorrhaphy performed for indirect inguinal hernia approximately 1.5 per 1000 population. In one patient on CAPD a peritoneogram using 99m Tc sulfur colloid suggested a patent processes vaginalis to account for scrotal edema on one side; the patient subsequently developed an indirect inguinal hernia on the other side just a few months after the repair. In view of high association of patent processus vaginalis with P.C.K. we recommend it is routinely searched in this group of patients and repaired at time of CAPD catheter insertion.

Alum irrigation in massive bladder hemorrhage in severe renal failure.

We report a patient with severe renal failure in whom massive bladder hemorrhage was successfully treated with alum irrigation. There was no substantial potassium or aluminum absorption with alum irrigation.