Microwave Combustion Synthesis and Characterization Studies of Magnetic Zn(1-x)Cd(x)Fe2O4 (0 ≤ x ≤ 0.5) Nanoparticles.

Nano-sized pure and Cd-doped ZnFe2O4 (Zn(1-x)Cd(x)Fe2O4 with x = 0.0-0.5) samples were synthesized by a simple microwave combustion method. The X-ray diffraction (XRD) analysis confirmed the single phase cubic spinel structure. The average crystallite size was found in the range of 17.47-41.21 nm. The lattice parameter is found to increase with increase in the concentration of Cd. Pure ZnFe2O4 and all compositions of the Zn-Cd ferrites showed similar particle-like morphologies, which is confirmed by high resolution scanning electron microscopy (HR-SEM). Energy dispersive X-ray (EDX) analysis shows that the theoretical and observed percentage of the elements; Zn2+, Cd2+ and Fe3+ are in the desired stoichiometric proportion. The UV-Visible diffuse reflectance spectrum (DRS) shows the band gap value increases with increasing Cd content. All the samples showed the characteristic near-band-edge emission at around 428 nm, which is observed by photoluminescence (PL) spectra. The magnetic properties were measured by using vibrating sample magnetometer (VSM) and it was found that the saturation magnetization is increased with increase the concentration of Cd content. The results revealed that for lower Cd concentration (x = 0.0-0.2) the samples shows a superparamagnetic behavior, whereas for higher concentration (x = 0.3-0.5), it becomes ferromagnetic.

A Novel Synthesis and Characterization Studies of Magnetic Co3O4 Nanoparticles.

Cobalt oxide (Co3O4) nanoparticles were synthesized by microwave combustion method (MCM) using urea as the fuel. For the purpose of comparison, they are also prepared by conventional combustion method (CCM). The prepared samples were examined by using X-ray diffraction (XRD), high resolution scanning electron microscopy (HR-SEM), high resolution transmission electron microscopy (HR-TEM), UV-Visible diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy and vibrating sample magnetometer (VSM). XRD analysis indicated that the as-prepared samples have well-crystalline cubic phase. HR-TEM images showed that Co3O4 nanoparticles have sphere-like structure with an average particle size in the range of 20-25 nm (MCM) and 45-50 nm (CCM). Optical properties of Co3O4 nanoparticles revealed the presence of two band gap (1.89 and 2.54 eV (MCM), 1.68 and 2.38 eV (CCM)) values, which in turn confirmed the semi-conducting properties. VSM measurements revealed a small hysteresis loop at room temperature thus indicating a weak ferromagnetism.

Phase II screening trial of lithium carbonate in amyotrophic lateral sclerosis: examining a more efficient trial design.

OBJECTIVE: To use a historical placebo control design to determine whether lithium carbonate slows progression of amyotrophic lateral sclerosis (ALS). METHODS: A phase II trial was conducted at 10 sites in the Western ALS Study Group using similar dosages (300-450 mg/day), target blood levels (0.3-0.8 mEq/L), outcome measures, and trial duration (13 months) as the positive trial. However, taking riluzole was not a requirement for study entry. Placebo outcomes in patients matched for baseline features from a large database of recent clinical trials, showing stable rates of decline over the past 9 years, were used as historical controls. RESULTS: The mean rate of decline of the ALS Functional Rating Scale-Revised was greater in 107 patients taking lithium carbonate (-1.20/month, 95% confidence interval [CI] -1.41 to -0.98) than that in 249 control patients (-1.01/month, 95% CI -1.11 to -0.92, p = 0.04). There were no differences in secondary outcome measures (forced vital capacity, time to failure, and quality of life), but there were more adverse events in the treated group. CONCLUSIONS: The lack of therapeutic benefit and safety concerns, taken together with similar results from 2 other recent trials, weighs against the use of lithium carbonate in patients with ALS. The absence of drift over time and the availability of a large database of patients for selecting a matched historical control group suggest that use of historical controls may result in more efficient phase II trials for screening putative ALS therapeutic agents. CLASSIFICATION OF EVIDENCE: This study provided Class IV evidence that lithium carbonate does not slow the rate of decline of function in patients with ALS over 13 months.

Psychiatric predictors of pseudoepileptic seizures in patients with refractory seizures.

This study compared psychiatric factors and diagnoses in patients with pseudoepileptic seizures and genuine seizures. A semistructured interview identified psychiatric diagnosis and the presence of psychiatric factors associated with conversion phenomena. Twenty-five subjects with medically refractory seizures were interviewed and followed prospectively until a definitive diagnosis of pseudoepileptic or genuine seizures was made by neurologists using video-EEG telemetry. Four factors help to identify patients with pseudoepileptic seizures: a psychiatric diagnosis of either somatization disorder or personality disorder, the presence of a childhood loss, or the presence of a model for seizure symptoms. These findings can aid clinicians in identifying patients who would benefit from referral to a video-EEG telemetry diagnostic unit.