Binder-less and free-standing Co–Fe metal nanoparticles-decorated PVdF-HFP nanofiber membrane as an electrochemical probe for enzyme-less glucose sensors

Co–Fe bimetallic nanoparticles-affixed polyvinylidene fluoride-co-hexafluoropropylene (PVdF-HFP) nanofiber membrane is fabricated using the electrospinning and chemical reduction techniques. The semicrystalline polymeric backbone decorated with the highly crystalline Co–Fe bimetallic nanoparticles enunciates the mechanical integrity, while the incessant and swift electron mobility is articulated with the consistent dissemination of bimetallic nanoparticles on the intersected and multi-layered polymeric nanofibers. The diffusion and adsorption of glucose are expedited in the extended cavities and porosities of as-formulated polymeric nanofibers, maximizing the glucose utilization efficacy, while the uniformly implanted Co⁴⁺/Fe³⁺ active centers on PVdF-HFP nanofibers maximize the electrocatalytic activity toward glucose oxidation under alkaline regimes. Thus, the combinative sorts including nanofiber and nanocomposite strategies of PVdF-HFP/Co–Fe membrane assimilate the enzyme-less electrochemical glucose detection concerts of high sensitivity (375.01 μA mM^?1 cm^?2), low limit of detection (0.65 μm), and wide linear range (0.001 to 8 mM), outfitting the erstwhile enzyme-less glucose detection reports. Additionally, the endowments of high selectivity and real sample glucose-sensing analyses of PVdF-HFP/Co–Fe along with the binder-less and free-standing characteristics construct the state-of-the-art paradigm for the evolution of affordable enzyme-less electrochemical glucose sensors.

     

Quantum chemical computation by DFT application of NLO molecule 2-aminopyridinium <Emphasis Type="Italic">p</Emphasis>-toluenesulphonate

We investigate the face-to-face collision between multisolitons in spin-1/2 quantum plasma. It is studied in the framework of the model proposed by Marklund et al in Phys. Rev. E 76, 067401 (2007). This study is done with the help of the extended Poincare–Lighthill–Kno (PLK) method. The extended PLK method is also used to obtain two Korteweg–de Vries (KdV) equations and the phase shifts and trajectories during the head-on collision of multisolitons. The collision-induced phase shifts (trajectory changes) are also obtained. The effects of the Zeeman energy, total mass density of the charged plasma particles, speed of the wave and the ratio of the sound speed to Alfvén speed on the phase shifts are studied. It is observed that the phase shifts are significantly affected by all these parameters.     

A liquid chromatography–tandem mass spectrometry method for the quantitation of actarit in rabbit plasma: application to pharmacokinetics and metabolic stability

Actarit (ATR), 4‐acetylaminophenylacetic acid is an orally effective disease‐modifying anti‐rheumatic drug widely prescribed for the treatment of rheumatoid arthritis. The present study demonstrates the first report on a selective and sensitive liquid chromatography–tandem mass spectrometry method for the quantification of ATR in rabbit plasma using p‐coumaric acid as an internal standard (IS). Following liquid–liquid extraction, chromatographic separation of the reconstituted samples was achieved isocratically on a Syncronis‐C18 column with a mobile phase consisting of aqueous ammonium acetate (10 mM, pH 4)‐ methanol and acetonitrile mixture (8 : 92, v/v) at a flow rate of 0.6 ml/min. ATR and IS were detected using electrospray ionization operated in negative multiple reaction monitoring mode. The calibration curve was linear (r² ≥ 0.990) over the concentration range of 1–4000 ng/ml with a lower limit of quantitation of 1 ng/ml. The mean extraction recovery of ATR and IS from rabbit plasma was greater than 85%. The method complied well with US Food and Drug Administration guidelines for selectivity, sensitivity, accuracy, precision, matrix effect, dilution integrity, carry‐over effect and stability. The method was successfully applied to in vitro metabolic stability (using rabbit liver microsomes) and in vivo pharmacokinetic study after oral administration of ATR at a dose of 10 mg/kg in New Zealand rabbits. Copyright © 2015 John Wiley & Sons, Ltd.     

N-heterocyclic carbene catalyzed aroylation of 3,5-dichloro-2(1H)-pyrazinones

The N-heterocyclic carbene catalyzed chemoselective C3-aroylation of 3,5-dichloro-2(1H)-pyrazinones with various aldehydes is reported. We herein describe results of this remarkable mild and efficient procedure.     

Experimental investigation on circumferential and axial temperature gradient over fuel channel under LOCA

In a nuclear reactor temperature rises drastically in fuel channels under loss of coolant accident due to failure of primary heat transportation system. Present investigation has been carried out to capture circumferential and axial temperature gradients during fully and partially voiding conditions in a fuel channel using 19 pin fuel element simulator. A series of experiments were carried out by supplying power to outer, middle and center rods of 19 pin fuel simulator in ratio of 1.4:1.1:1. The temperature at upper periphery of pressure tube (PT) was slightly higher than at bottom due to increase in local equivalent thermal conductivity from top to bottom of PT. To simulate fully voided conditions PT was pressurized at 2.0 MPa pressure with 17.5 kW power injection. Ballooning initiated from center and then propagates towards the ends and hence axial temperature difference has been observed along the length of PT. For asymmetric heating, upper eight rods of fuel simulator were activated and temperature difference up-to 250 °C has been observed from top to bottom periphery of PT. Such situation creates steep circumferential temperature gradient over PT and could lead to breaching of PT under high pressure.     

Total synthesis of carbazole alkaloids

A Suzuki-Miyaura cross coupling, followed by triphenylphosphine mediated Cadogan reductive cyclization sequence provided efficient access to a series of carbazole alkaloids.In the present work, this approach was applied to the total synthesis of mukonine, clauszoline K, koenoline, murrayanine, murrayafoline A, mukoeic acid, glycoborine, glycozolicine, mukolidine, mukoline, glycozoline, 3-methoxy-9H-carbazole-1-carboxylic acid methyl ester, (3-methoxy-9H-carbazol-1-yl)-methanol, 3-methoxy-9H-carbazole-1-carbaldehyde, 3-methoxy-9H-carbazole-1-carboxylic acid, 2-methyl-9H-carbazole and nonsteroidal anti-inflammatory drug (NSAID) carprofen and its derivatives.     

Palladium‐mediated synthesis of novel nimesulide derivatives

Synthesis of a series of compounds structurally related to the anti‐inflammatory agent nimesulide has been accomplished via Pd‐catalyzed C? C bond forming reactions. Thus 4‐iodo derivative, prepared from nimesulide, participated in Sonogashira (copper‐free), Heck and Suzuki coupling reactions to afford the corresponding alkynyl, alkenyl and aryl substituted products. Some of the compounds synthesized were tested for anti‐inflammatory activities in vivo. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis,spectral characterization,molecular docking studies,biological activity of (E)-2-((E)-3-(3,4,5-trimethoxyphenyl)allylidene) and (E)-N-phenyl 2-((E)-3-(3,4,5-trimethoxyphenyl)allylidene)hydrazinecarbothioamides and their Cu(II) complexes

Two slightly distorted octahedral complexes of copper(II) with (E)-2-((E)-3-(3,4,5-trimethoxyphenyl)allylidene)hydrazinecarbothioamide (L1) common name 3,4,5-trimethoxy-cinnamaldehydethiosemicarbazone and (E)-N-phenyl-2-((E)-3-(3,4,5-trimethoxyphenyl)-allylidene)hydrazinecarbothioamide (L2) common name 3,4,5-trimethoxycinnamaldehyde-4-phenylthiosemicarbazone have been synthesized. The two free ligands and their copper(II) complexes were characterized by spectroscopic techniques like FT-IR, FT-Raman, UV, EPR, Powder X-ray diffraction and cyclic voltammetry. The EPR spectra evidenced a rhombically distorted octahedron geometry for both the copper(II) complexes. The band gap calculations for the ligands L1, L2 and their complexes Cu(L1)₂Cl₂ and Cu(L2)₂Cl₂ were found to be 2.98, 2.61, 2.66 and 2.50 eV respectively. Cu(L1)₂Cl₂ and Cu(L2)₂Cl₂ have shown 50% of viability at 80 μg/ml and 60 μg/ml. The anti-oxidant activity study revealed that the compounds are good reductants of DPPH radical. Moderate to good anti-bacterial activity is shown by the compounds against the Gram-positive and Gram-negative bacteria. Molecular docking studies have been carried out to predict the orientation and binding mode of analysis in the active site. The synthesized ligand and complex well occupy (catalytic triad and adenine-binding site) in the active site of β-ketoacyl-acyl carrier protein synthase III enzyme, and also well occupy in helix 11 (in the DCS complex) of human estrogen receptor. Moreover they form water mediated hydrogen bond and hydrogen bond with Cys530 residue.     

Computational flow and heat transfer of multiple circular jets impinging on a flat surface with effusion

Computational investigations are reported on the local flow and heat transfer characteristics from staggered, multiple circular air jets impinging on a flat surface with effusion holes. The geometrical and flow parameters for the computational study are chosen as per the experimental arrangement of Cho and Rhee J Turbomachinery 123:601–608, (14) so as to explain salient features observed in these experiments. The two peaks in the Nusselt number observed in the case of H/D = 6 and three peaks in the case of H/D = 2 are attributed to the flow characteristics such as primary vortices forming an up-wash region, followed by secondary vortices resulting in a secondary stagnation zone. The magnitude of local peak in heat transfer increases up to 88% with increasing values of D/d from 0.5 to 1.5 at Re = 10,000.