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Background: Obstructive sleep apnea (OSA) is an eminently modifiable and emerging risk factor for acute stroke. This prospective study was conducted in a tertiary care center to estimate the proportion of OSA in patients presenting with acute stroke.Materials and Methods: Consecutive stable patients with acute stroke were included. Stroke severity, subtype, and anatomical location were classified using standardized scales. Included subjects were screened for OSA with a detailed history (intrusive snoring, witnessed apneas, and excessive daytime sleepiness), quantification of sleepiness (Epworth Sleepiness Scale), clinical examination, and level-3 polysomnography. OSA severity was quantified based on the Apnea–Hypopnea Index.Results: 104 clinically stable stroke patients (67 males and 37 females) were included in the study; mean age was 60.9±13.2 years. Most patients (92 [88.5%]) had ischemic stroke, 9 (8.7%) had hemorrhagic stroke, and 3 (2.9%) had a transient ischemic attack. Intrusive snoring was reported by 37 (35.6%) patients, excessive daytime sleepiness by 32 (30.8%) and witnessed apneas by 19 (18.3%) patients. On level-3 polysomnography, 74 (71.2%) patients were diagnosed to have OSA. Mild OSA was diagnosed in 34 patients, while moderate and severe OSA were diagnosed in 20 patients each.Conclusions: Our study has demonstrated a strong causal relationship between OSA and stroke, thus reinforcing the need to screen all patients with stroke for OSA. Timely institution of nocturnal noninvasive ventilation in stroke patients with OSA would help to reduce the effects of OSA on stroke morbidity and recurrence.

The multiferroic compounds with chemical formula Bi1−xBaxFeO3 with x = 0.00, 0.05, 0.10, 0.15, 0.20, and 0.25 were synthesized by sol–gel route. Thermogravimetric and differential thermal analysis were performed on a pure BiFeO3 sample to know the required annealing temperature. Its structural, morphological, optical, electrical and dielectric properties were studied systematically by standard techniques. X-ray diffraction (XRD) and transmission electron microscopy techniques were employed to study the structure and phase, as well as the morphology of the samples respectively. The transition from the distorted rhombohedral perovskite (ABO3) to hexagonal crystal structure was revealed by XRD pattern with Ba2+ substitution having R3c space group. UV-visible absorption spectra show that the absorption edge shifts to lower wavelength with increasing Ba2+ concentration. DC electrical resistivity measurements revealed a linear decrease in resistivity carried out in the temperature range of 343–1073 K using a standard two probe method. The dielectric parameters such as dielectric constant (e′) and loss tangent (tanδ) were measured at room temperature in the frequency range 50 Hz–5 MHz, which was found to decrease with increasing frequency.

An efficient and convenient synthesis of pyrrolo[1,2-a]quinoxalines from 1-(2-aminoaryl)pyrroles and arylacetic acids has been described by using a combination of CuSO4 as the catalyst and 2,2'-bipyridyl as the ligand in the presence of O2 as an oxidant. The prominent features of this method are use of readily available starting materials, inexpensive catalyst, broad substrate scope and high product yields.

Ba2+ doped Bismuth ferrite nanoparticles having general formula Bi1-xBaxFeO3 (where, x = 0.00 and 0.20) were successfully synthesized by sol gel method, using nitrates as a starting material. Ethylene glycol was used as a solvent. The synthesized powder was sintered at 650°C for 4 hours to obtain pure phase BFO. Leaching with dilute nitric acid (HNO3) and distilled water (H2O) is done to remove the impurities. The structural, morphological, magnetic and ferroelectric properties were systematically investigated using standard characterization techniques like X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM) and room temperature magnetic behavior of the samples was studied using pulse field hysteresis loop tracer technique showing increase in saturation magnetizaion. P-E loop confirms the ferroelectric behavior of prepared nanoparticles. The coexistence of ferromagnetic and ferroelectric hysteresis loops in BFO and Bi0.8Ba0.2FeO3 nanoparticles samples at room temperature; it indicates that the samples are potential candidates for information storage and spintronics devices. The increase in magnetic properties may be important for practical application at room temperature.

Highly stable NiFe2O4 ferrofluids were successfully prepared by two step method. The magnetic NiFe2O4 nanoparticles were prepared by sol-gel auto combustion method. In order to prepare ferrofluid distilled water was used as a base fluid. The X-ray diffraction (XRD), Scanning electron microscopy (SEM) was used to characterize structure and morphology of the nanoparticles. XRD results show the single phase spinel structure with crystallite of 27nm. Electrical conductivity of ferrofluids was measured by Aqua Pro Electrical Conductivity (EC) meter. Density of ferrofluids was measured by specific gravity bottle. Electrical conductivity and density of the ferrofluids were measured as a function of volume fraction. It is observed that, the electrical conductivity and density of ferrofluids increases with increase in volume fraction.