Tuning of multi-magnetic phase and exchange bias effect by antisite disorder in Ca-doped La2CoMnO6double perovskites.

The exchange bias effect at the magnetic interfaces and multi-magnetic phases strongly depends on the antisite disorder (ASD) driven spin configuration in the double perovskite systems. The percentage of ASD in double perovskites is extensively accepted as a key for designing diverse new nanospintronics with tailored functionalities. In this regards, we have investigated such ASD driven phenomena in Ca2+doped bulk and polycrystalline La2-xCaxCoMnO6(0 ⩽x⩽ 1) series of samples. The structural and Raman studies provide evidence of an increase in the disorder due to the increment of Ca concentration in the parent compound (x= 0). The enhancement of disorder in the doped system induces various magnetic orderings, magnetic frustration and cluster glass-like behavior, which have been confirmed from AC and DC magnetic studies and neutron diffraction studies. As a result, significantly large exchange bias effects, namely zero-field cooled (spontaneous) and field-cooled (conventional) exchange bias, are found. These results reveal the tuning of ASD by doping, which plays an active role in the spin configuration at the magnetic interfaces.

Impact of Gd Doping on the Microstructural-, Electronic-, Magnetotransport, and Magnetic Properties of Pr0.6Gd0.1Sr0.3MnO3 Nanomanganite.

Gadolinium doping effects on structural-, electronic transport and magnetic properties of Pr0.6Gd0.1Sr0.3MnO3 (PGSMO) nanomanganite (40-65 nm) have been investigated. We have considered the core-shell structure of our PGSMO nanoparticles, which can explain its intriguing magnetic and transport properties. It is reported 65 nm sample exhibits higher metal to insulator transition temperature, TP (∼215 K) and less resistive behavior compare to its nano counterparts. Enhanced low-field magnetoresistance (LFMR) is observed with a reduction of particle size; however maximum change in magnetoresistance (MR), ∼72% is recorded for 65 nm sample around TP at 60 kOe field. Low-temperature magnetization data reveals the existence of glassy phase in the compound. It is revealed that substitution of optimal Gd doping at A site on nanometric scale promotes exotic magnetic and transport properties on nanoscale without adding any external physical perturbation or introducing any significant lattice distortion.

Diagnosis of superficial mycoses by direct microscopy - A statistical evaluation.

A mycological study was undertaken in 250 cases of superficial mycotic infections, which included 210 cases of dermatophytosis, 18 cases of cutaneous candidiasis and 22 cases of tinea versicolor. The scrapings from all the cases were subjected to direct microscopic examination in 10% KOH solution and culture was done in case of candidiasis and dermatophytosis. Out of 250 cases direct microscopy was positive (KOH +ve) in 88 cases of dermatophytosis, 11 cases of candidiasis and all cases of tinea versicolor. Culture for dermatophytes and candida species in SDA medium were positive in 76 and 9 cases respectively. The diagnostic sensitivity, specificity, positive predictive value, negative predictive value and the overall efficiency of the direct microscopy in the diagnosis of superficial mycotic infections were calculated to be 89.41%, 83.90%, 76.76%, 93.02% and 85.96% respectively.

Drill biopsy in the diagnosis of lung lesions.

A high speed pneumatic drill was used to perform 190 percutaneous transthoracic biopsies in 161 patients. The resultant cores of tissue provided a definite diagnosis in 146 patients, giving a success rate of 90.7%. Complications occurred in 58 patients, subcutaneous emphysema being the most common, though only seven patients required active treatment, giving a rate of 3.7% for important complications. One patient died within 24 hours of the biopsy procedure owing to asphyxia resulting from aspiration of the contents of an acutely dilated stomach. Our experience clearly establishes that the drill biopsy as used by us is simple and safe and can be carried out in an outpatient department, yielding better overall results than any other procedure for closed biopsy of the lung currently practised.