Comparative efficacy of cedarwood oil and xylene in hematoxylin and eosin staining procedures: An experimental study.

BACKGROUND: Xylene is used as a clearing agent in hematoxylin and eosin (H and E) staining of tissue sections in routine histopathology based diagnosis. However, the hazards associated with exposure to xylene are of concern. Numerous solutions mainly essential oils have been evaluated in the past as clearing agents, which can possibly be substituted for xylene during the routine tissue processing. AIM: The aim of this study is to compare the efficacy of essential oil (cedarwood oil), as a possible replacement for xylene in H and E staining procedures. MATERIALS AND METHODS: The study was carried out in the Department of Oral Pathology and Microbiology. Thirty paraffin blocks of the routine biopsy specimen were retrieved from the department archives. The cedarwood oil was procured from organic and essential oil dealer in the local market. Two to three paraffin sections of four micron thickness were cut from each of the 30 paraffin blocks of processed tissue specimens, were subjected to different clearing agents: Essential oil (8% cedarwood oil) or xylene and stained with H and E stain. The stained sections were scored based on nuclear and cytoplasmic details, clarity and uniformity of staining. RESULTS: Significant correlation was observed between cedarwood oil and xylene in terms of the three staining quality parameters assessed. CONCLUSIONS: We conclude that cedarwood oil can be an effective, eco-friendly and safe alternative to xylene as a clearing agent in the histopathological laboratory.

Removal of ocular artifacts from EEG using adaptive thresholding of wavelet coefficients.

Electroencephalogram (EEG) gives researchers a non-invasive way to record cerebral activity. It is a valuable tool that helps clinicians to diagnose various neurological disorders and brain diseases. Blinking or moving the eyes produces large electrical potential around the eyes known as electrooculogram. It is a non-cortical activity which spreads across the scalp and contaminates the EEG recordings. These contaminating potentials are called ocular artifacts (OAs). Rejecting contaminated trials causes substantial data loss, and restricting eye movements/blinks limits the possible experimental designs and may affect the cognitive processes under investigation. In this paper, a nonlinear time-scale adaptive denoising system based on a wavelet shrinkage scheme has been used for removing OAs from EEG. The time-scale adaptive algorithm is based on Stein's unbiased risk estimate (SURE) and a soft-like thresholding function which searches for optimal thresholds using a gradient based adaptive algorithm is used. Denoising EEG with the proposed algorithm yields better results in terms of ocular artifact reduction and retention of background EEG activity compared to non-adaptive thresholding methods and the JADE algorithm.

Simultaneous separation and preconcentration of trace elements in water samples by coprecipitation on manganese dioxide using D-glucose as reductant for KMnO(4).

A field oriented and economical method of coprecipitation of trace elements like Al, Au, Bi, Cd, Co, Cu, Fe, Mo, Ni, Pb, Pd, Ti, V, W, Zn and REE has been developed. A novel reductant D-glucose, reduces KMnO(4) in solution to form a precipitate of MnO(2.) Two liters of clear natural water sample is adjusted to pH 3.5-4.0, and is treated with 10 ml of 1% KMnO(4) and 20 ml of 0.1% D-glucose. The sample is heated at a temperature of 75-80 degrees C, MnO(2) is formed which coprecipitates the above trace elements. The precipitate is separated by filtration, dissolved in 2 ml of 50% HCl and 2 ml of 30% H(2)O(2) and diluted to 25 ml for analysis using AAS and ICP-AES. The recoveries were found to be 96-105%. The preconcentration factor is 80. Limits of determination by the proposed method in natural waters are 1 mug l(-1) for Al, Cd, Mo, V, W, Ti and Zn, 5 mug l(-1) for Au, Bi, Co, Cu, Fe, Ni, Pb and Pd and 8 mug l(-1) for REE. The RSD of the present procedure (n=5) is 8% at approximately 5 mug l(-1) level. Twenty water samples can be analyzed by an analyst in an 8-h day.

Determination of phosphorous in titanium bearing minerals by potentiometric titration using Pb-ion selective electrode.

A method for phosphorous determination in titanium bearing minerals by potentiometric titration using a Pb-ion selective electrode has been developed. Sample decomposition is achieved by means of K(2)CO(3) fusion in a platinum crucible at 800 degrees C for 30 min in a muffle furnace, and subsequent leaching with water of the fused melt. The aqueous leachate is neutralised with HClO(4) and subsequent boiling. The obtained solution is used for titration with Pb(ClO(4))(2), and the Pb-ion selective electrode detects the end point. The lowest concentration determinable is 0.02% P(2)O(5) in a solid sample. The method was applied on in-house titanium bearing mineral samples and on IGS-31 ilmenite sample (British Geological Survey, UK). Synthetic samples were prepared and analysed, and phosphorous recovery is in the range 98-106%. The recovery and accuracy of the present method have been validated by spiking experiments and by comparing with the spectrophotometric values, respectively. The precision of the proposed method in terms of relative standard deviation is 2.0%.