Degradation of Organic Cyanides byPseudomonas aeruginosa

A bacterium capable of utilizing acetonitrile (methyl cyanide) as the sole source of carbon and nitrogen was isolated from soil and identified asPseudomonas aeruginosa. This bacterium could also utilize and oxidize numerous lower-mol-wt nitrile compounds and their corresponding amides as growth substrates. A metabolite of acetonitrile in the culture medium was determined to be ammonia. The accumulation of ammonia in the culture medium was proportional to the concentration of the substrate and the inoculum. Cell extracts of the bacterium contained activities corresponding to nitrile aminohydrolase (E C 3.5.5.1) and amidase (E C 3.5.1.4), which regulate the degradation of acetonitrile. Both enzymes were inducible and hydrolyzed a wide range of substrates, and it was determined that the specific activity of amidase was far greater than the activity of nitrile aminohydrolase.     

A High-Performance Asymmetric Supercapacitor Based on Tungsten Oxide Nanoplates and Highly Reduced Graphene Oxide Electrodes

Tungsten oxide/graphene hybrid materials are attractive semiconductors for energy-related applications. Herein, we report an asymmetric supercapacitor (ASC, HRG//m-WO₃ ASC), fabricated from monoclinic tungsten oxide (m-WO₃) nanoplates as a negative electrode and highly reduced graphene oxide (HRG) as a positive electrode material. The supercapacitor performance of the prepared electrodes was evaluated in an aqueous electrolyte (1 m H₂SO₄) using three- and two-electrode systems. The HRG//m-WO₃ ASC exhibits a maximum specific capacitance of 389 F g⁻¹ at a current density of 0.5 A g⁻¹, with an associated high energy density of 93 Wh kg⁻¹ at a power density of 500 W kg⁻¹ in a wide 1.6 V operating potential window. In addition, the HRG//m-WO₃ ASC displays long-term cycling stability, maintaining 92 % of the original specific capacitance after 5000 galvanostatic charge–discharge cycles. The m-WO₃ nanoplates were prepared hydrothermally while HRG was synthesized by a modified Hummers method.     

Lipoic Acid Combined with Melatonin Mitigates Oxidative Stress and Promotes Root Formation and Growth in Salt-Stressed Canola Seedlings (Brassica napus L.)

Lipoic acid (LA) and melatonin (MT) are pleiotropic molecules participating in plant stress resistance by modulating cellular biochemical changes, ion homeostasis, and antioxidant enzyme activities. However, the combined role of these two molecules in counteracting the detrimental impacts of salinity stress is still unknown. In the present study, we determined the effects of exogenous LA (0.5 µM), MT (1 µM) and their combination (LA + MT) on growth performance and biomass accumulation, photosynthetic pigments, enzymatic and non-enzymatic antioxidant activities, and ions homeostatic in canola (Brassica napus L.) seedlings under salinity stress (0, 100 mM) for 40 days. The results indicate that exogenous application of LA + MT improved the phenotypic growth (by 25 to 45%), root thickness (by 68%), number of later lateral roots (by 52%), root viability (by 44%), and root length (by 50%) under salinity stress. Moreover, total soluble protein, chlorophyll pigments, the concentration of superoxide dismutase (SOD), catalase peroxidase (CAT), and ascorbic peroxidase (ASA) increased with the presence of salt concentration into the growth media and then decreased with the addition of LA + MT to saline solution. Leaf protein contents and the degradation of photosynthetic pigments were lower when LA + MT treatments were added into NaCl media. The proline and phenol contents decreased in the exogenous application of LA + MT treatments more than individual LA or MT treatments under the salinity stress. The incorporation of LA or MT or a combination of LA + MT to saline solution decreased salinity-induced malondialdehyde and electrolyte leakage. In conclusion, the alteration of metabolic pathways, redox modulation, and ions homeostasis in plant tissues by the combined LA and MT application are helpful towards the adaptation of Brassica napus L. seedlings in a saline environment. The results of this study provide, for the first time, conclusive evidence about the protective role of exogenous LA + MT in canola seedlings under salinity stress.     

Thermal performance of micro-polymers containing nano-solid structures during transport phenomenon

Journal of Thermal Analysis and Calorimetry - The inclusion of solid nano-structures in the liquid changes its rheology and hence its thermal performance. This article considers the impact of...     

Bioanalytical LC‐MS/MS method validation for plasma determination of topiramate in healthy Indian volunteers

A LC‐MS/MS method for plasma topiramate analysis is delineated involving least number of healthy volunteers. Topiramate and amlodipine internal standard (IS) were extracted by simple centrifuge‐coupled solid‐phase extraction and reverse‐phase chromatographic separation was performed on an Ascentis C₁₈ column. Turbo‐spray negative‐ion mode multiple‐reaction monitoring was selected for mass pair detection at m/z 338.3 → 78.0 and m/z 407.3 → 295.5 for analyte and IS respectively. The method showed a dynamic linearity range from 10.4 to 2045.0 ng/mL, lower limit of quantitation achieved at 10.4 ng/mL and finally a mass spectrometric total run time of within 2.5 min for human sample analysis. Bioequivalence was assessed successfully using this fully validated method on 16 fasted Indian male subjects with 25 mg topiramate tablet administration. An appropriate study design describes plasma samples collection up to 216 h post dose in two periods, separated by a 28 day washout period. The challenge of half‐life matching for test and reference drug was achieved with 73.43 ± 9.68 and 73.06 ± 14.03 h, respectively, and intra‐subject coefficient of variation achieved within 11% for AUCs and C_max evaluated by non‐compartmental pharmacokinetic analysis. The results of LCMS topiramate complete method validation supported by pharmacokinetic study have not been published before, and are presented and discussed for the first time in this article. Copyright © 2009 John Wiley & Sons, Ltd.     

Diffraction of sound waves by a finite barrier in a moving fluid

The diffraction of a line source by an absorbing finite barrier, satisfying Myers' impedance condition [M.K. Myers, On the acoustic boundary condition in the presence of flow, J. Sound Vibration 71 (1980) 429-434] in the presence of a subsonic flow is studied. The problem is solved analytically by using Integral transforms, Wiener-Hopf technique and the asymptotic methods. The expression for the diffracted field is shown to be the sum of the fields produced by the two edges of the strip and a field due to the interaction of the two edges. The diffracted field in the far zone is determined by the method of steepest decent.