Chemical Constituents, Antimicrobial Investigations, and Antioxidative Potentials of Anethum graveolens L. Essential Oil and Acetone Extract: Part 52

ABSTRACT: The antioxidant, antifungal, and antibacterial potentials of essential oil and acetone extract of Anethum graveolens L. were investigated in the present study. The extract has shown excellent activity for the inhibition of primary and secondary oxidation products for rapeseed oil in comparision with butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), which were evaluated using peroxide, thiobarbituric acid, p‐anisidine, and carbonyl values. The activity of extract was further confirmed using other antioxidant properties such as ferric thiocyanate method inlinoleic acid system, which reducing power and scavenging effect (%) on 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical. Using inverted Petri plate method, the volatile oil completely inhibited the growth of Fusarium graminearum at 6 μL dose. Moreover, using poison food technique, the essential oil was found to be highly effective for controlling the growth of Penicillium citrinum and Aspergillus niger. In antibacterial investigations, using agar well diffusion method, the extract has shown better activity for Staphylococcus aureus and Bacillus cereus in comparison with commercial bactericide. However, essential oil has shown better activity for Pseudomonas aeruginosa. Gas chromatographic‐mass spectroscopy studies on essential oil resulted in the identification of 35 components, which account for the 98.9% of the total amount. The major component was carvone (55.2%) followed bylimonene (16.6%), dillapiole (14.4%), andlinalool (3.7%). The analysis of acetone extract showed the presence of 25 components, which account for 94.5% of the total amount. The major components were dill apiole (43.2%), linoleic acid (23.1%), trans‐anethole (11.0%), 2‐propanone, 1‐(4‐methoxyphenyl) (4.6%), carvone (3.1%), p‐anisaldehyde (2.7%), and myristicin (1.5%). In conclusion, the results presented here show that dill essential oil could be considered as a source for natural antimicrobial, whereas its extract could be considered as an alternative source of natural antioxidant.     

Electrical conduction and dielectric behaviour of the oxidic spinel Li0.5+0.5xCr0.3TixFe2.2−1.5XO4

The electrical conductivity of polycrystalline lithium-chromium ferrites substituted successively with Ti⁴⁺ was studied as a function of composition and temperature. The resistivity increased with composition and all the samples exhibited a change in slope in the resistivity-temperature curve. Two different regions with a large variation in activation energies were found. The dielectric constant and loss factor for different compositions were measured in the frequency range of 10kHz to 10 MHz. The dielectric permittivity showed a dispersion with frequency for all the samples. Peaks were observed for the samples with 0.4 x 0.8. The possible mechanisms involved are discussed.     

Study on the structural and electrical properties of YMnO3 co-substituted with transition metal ions at Mn-site and their conduction mechanism

Journal of Materials Science: Materials in Electronics - Rare earth manganite YMnO3 and YMn0.9Cr0.06Fe0.04O3 wherein transition metal ions are co-substituted at Mn-sites, were synthesized via...     

A genetic algorithm that exchanges neighboring centers for k-means clustering

We present a genetic algorithm for selecting centers to seed the popular k-means method for clustering. Using a novel crossover operator that exchanges neighboring centers, our GA identifies superior partitions using both benchmark and large simulated data sets.     

Chronic Low-Dose Alcohol Consumption Attenuates Post-Ischemic Inflammation via PPARγ in Mice

Ischemic stroke is one of the leading causes of death and permanent disability in adults. Recently, we found that light alcohol consumption (LAC) suppresses post-ischemic inflammatory response, which plays an important role in ischemic brain damage. Our goal was to determine the role of peroxisome proliferator-activated receptor-gamma (PPARγ) in the anti-inflammatory effect of LAC against transient focal cerebral ischemia. In in vivo study, male C57BL/6J wild type (WT) and endothelial-specific conditional PPARγ knockout mice were gavage fed with 0.7 g/kg/day ethanol or volume-matched water daily for 8 weeks. From the 7th week, 3 mg/kg/day GW9662 (a selective PPARγ antagonist) was intraperitoneally given for two weeks. Cerebral ischemia/reperfusion (I/R) injury and expression of manganese superoxide dismutase (MnSOD) and adhesion molecules, neutrophil infiltration, and microglial activation in the cerebral cortex before and following a 90 min unilateral middle cerebral artery occlusion (MCAO)/24 h reperfusion were evaluated. In in vitro study, the impact of chronic alcohol exposure on expression of PPARγ and MnSOD in C57BL/6J mouse brain microvascular endothelial cells (MBMVECs) was measured. PPARγ and MnSOD were significantly upregulated in the cerebral cortex of ethanol-fed WT mice and low-concentration ethanol-exposed C57BL/6J MBMVECs. GW9662 significantly inhibited alcohol-induced upregulation of MnSOD. Eight-week ethanol feeding significantly reduced cerebral I/R injury and alleviated the post-ischemic inflammatory response (upregulation of intercellular adhesion molecule-1 (ICAM-1) and E-selectin, microglial activation, and neutrophil infiltration). Treatment with GW9662 and endothelial-specific conditional knockout of PPARγ did not alter cerebral I/R injury and the inflammatory response in the control mice but abolish the neuroprotective effect in ethanol-fed mice. In addition, GW9662 and endothelial-specific conditional knockout of PPARγ diminished the inhibitory effect of LAC on the post-ischemic expression of adhesion molecules and neutrophil infiltration. Our findings suggest that LAC may protect against cerebral I/R injury by suppressing the post-ischemic inflammation via activation of PPARγ.     

Spectral slope based analysis and classification of stressed speech

In this study, spectral slope based features are investigated for characterization and classification of stressed speech. The vocal tract spectrum is modulated with glottal flow spectra, resulting a tilt in the overall spectrum. In this study, spectral tilt is analyzed for different stress classes. Relative formant peak displacement (RFD) is proposed as the displacement of formant peaks from the 1 ^st formant peak. The displacement of 2 ^nd , 3 ^rd and 4 ^th formant peaks from 1 ^st formant peak is termed as RFD ₂, RFD ₃ and RFD ₄, respectively. The features are extracted from linear prediction coefficient (LPC) and cepstrally smoothed log spectrum, respectively. Analysis shows that stress effects higher formant region more than lower formant region. To evaluate the effectiveness of this feature for different stress classes, the performance of stress classification is evaluated. A simulated stressed speech database is collected under four stress conditions, namely, neutral, angry, sad and Lombard from fifteen speakers. The performance of RFD feature is similar to Mel-frequency cepstral coefficient (MFCC). This shows that RFD feature have approximately same discrimination capability for stress as MFCC. Further, the performance of cepstrally smoothed log spectra derived RFD are higher than LPC derived RFD feature. RFD features are combined with MFCC in feature, score and rank level and found improved performance.