Design of high-speed data transfer turbo code for body channel communication transceivers

In this work, a digital differential transmitter based on low-power wireless compensation transceiver for body channel communication (BCC) is proposed. Further, the proposed transceiver is composed of Touch Status Detection Unit (TSDU), Wireless Status Compensation Unit (WSCU), and a reconfigurable preamplifier. Initially, the human body channel environment for wireless communication is investigated based on properties from 1 to 100 MHz. Further, the turbo code-based encoding scheme is used to encode the data before transferring the data on the transmitter side. Also, the proposed error-correcting parallel turbo decoder using a modified step-by-step algorithm is presented. The turbo code-based decoding scheme is used to recover the error-free transmitted data at the receiver side. Results demonstrate that the proposed BCC transceiver is designed using 90 nm CMOS technology and it is observed that the proposed BCC transceiver has utilized an area of 600mm². Also, the maximum data rate achieved by a proposed BCC transceiver was 100 Mbps, and the overall transceiver power consumption is 0.42 mW, and energy for communication is 0.02 nj/b.     

Ceric ammonium nitrate supported HY-zeolite：An efficient catalyst for the synthesis of 1, 8-dioxo-octahydroxanthenes

Ceric ammonium nitrate （CAN） supported HY-zeolite has been used as an efficient catalyst for the one- pot synthesis of 1,8-dioxo-octahydroxanthenes from the readily available 1,3-diketone and aromatic aldehydes under solvent-free conditions. The present methodology is cost-effective in addition to other advantages like high yields of products in shorter reaction time and simple workup procedure without the use of any injurious solvents.     

Synthesis,anticancer evaluation,and docking studies of some novel azo chromene derivatives

We have described a simple, convenient, and high-yielding one-pot synthesis of novel azo chromene derivatives via a three-component reaction of various azo aldehydes with dimedone and malononitrile using 10 mol% of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as catalyst and ethanol as solvent at reflux condition. All the synthesized compounds have been characterized using Fourier-transform infrared spectroscopy (FT-IR), ¹H NMR, ¹³C NMR, and HR-MS spectra and molecular docking was performed to explore new inhibitors of human placental aromatase cytochrome P450 and cyclooxygenase-2 enzymes. Of all the compounds docked, compound (E)-2-amino-4-(4,4-dimethyl-2,6-dioxocyclohexyl)-6-((3-methoxyphenyl)diazenyl-4H-chromene-3-carbonitrile ( 4o ) showed good binding affinity with the active site of human placental aromatase cytochrome P450 enzyme (PDB: 3EQM) with inhibition constant (Ki) 1.66 nM and compound 4o also showed good binding affinity with the active site of cyclooxygenase-2 enzyme (PDB: 6COX) with inhibition constant (Ki) 367.17 pM. In vitro anti-cancer activity studies against MCF-7 cells were also performed for compounds 4o , anastrozole and celecoxib. Compound 4o showed an effective cytotoxicity at 19.8 μg/ml compared to anastrozole and celecoxib (24.7 and 26.2 μg/ml).     

Design,synthesis, molecular docking,and spectral studies of new class of carbazolyl polyhydroquinoline derivatives as promising antibacterial agents with noncytotoxicity towards human mononuclear cells from peripheral blood

In the present study, we report the design and eco-benign synthesis of new class of carbazolyl-1,4-dihydropyridine (1,4-CDHP) and carbazolyl-1,8-dioxodecahydroacridine (CAD) derivatives via a three-component coupling reaction of substituted carbazole aldehydes, ethyl acetoacetate/dimedone, and ammonium acetate under solvent-free conditions at 112°C to 115°C. We also report an efficient one-pot synthesis of new class of carbazolyl polyhydroquinoline (CPQ) derivatives via a four-component coupling reaction of substituted ethyl acetoacetate, dimedone, ammonium acetate, and carbazole aldehydes in acetonitrile/water medium (3:1) at 73°C to 75°C in moderate yields. All the products were thoroughly characterized by ¹H NMR, ¹³C NMR, Fourier transform infrared (FTIR), mass spectral, and CHN analysis. The synthesized heterocyclic compounds were evaluated for their in vitro antibacterial activity against pathogenic strains of both Gram-negative and Gram-positive bacteria. Minimum inhibitory concentration (MIC) of the active compounds was evaluated by macrodilution method. The CPQ derivative ( 8a ) displayed superior antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, and Salmonella typhi with the MIC values of 16.0 to 32.0 μg/mL in comparison with the reference drug. The mechanism of antibacterial action of the CPQ derivatives was investigated via scanning electron microscope (SEM) studies. The molecular docking studies indicate that the CPQ derivative ( 8a ) binds to the cell wall protein of E coli and P aeruginosa by formation of hydrogen bonds with amino acid residues (TYR328 and GLU249) of the bacterial cell wall protein. The 1,4-CDHP, CAD, and CPQ derivatives were either noncytotoxic or exhibited minimal cytotoxicity towards human mononuclear cells from peripheral blood. All the products were evaluated for Lipinski rule of five (RO5) and were found to have good oral bioavailability.     

Determination of direct orange 8 in effluent using a polypyrrole modified electrode

Electrochemical studies of direct orange 8 were carried out with a bare glassy carbon electrode (GCE) and a polypyrrole-coated GCE in aqueous acetonitrile medium using voltammetric techniques. One reversible couple around 0.3?V due to the redox reaction of the phenol group, one reduction peak around ?0.4?V due to reduction of the azo group and one oxidation peak around 1.0?V due to oxidation of the amino group were observed. Chronocoulometric studies revealed dye adsorption on the GCE. A square-wave stripping method was developed for the determination of the dye at pH 13.0, and a linear calibration equation obtained. The reproducibility in the measurement of peak currents was confirmed from the RSD value 2.8% at 0.001?mg?mL^?1 concentration. A comparison of the stripping voltammetric method with the UV-Vis spectrophotometric method was made. The determination limits are wider and the RSD value is lower in the stripping voltammetric method. The concentration of the dye present in dye effluent was determined using this method.     

Improved water-splitting behaviour of flame annealed TiO2 nanotubes

In the present work we investigate the effect of flame annealing on the water-splitting properties of anodic TiO₂ nanotubes. It is shown that flame annealed (FA) nanotubes can yield a two-fold increase in the maximum water-splitting efficiency under standard AM 1.5 conditions compared to classic annealing treatments. The improved efficiency is mainly the result of the fact that using FA, a higher rutile content can be established in the tube walls without a thermal degradation of the tube morphology. A minor, secondary effect is carbon doping which is caused mainly by organic remnants from the tube formation electrolyte.     

Photoisomerization of Trans Ortho‐, Meta‐, Para‐Nitro Diarylbutadienes: A Case of Regioselectivity

A series of ortho‐, meta‐ and para‐substituted trans‐nitro aryl (phenyl and pyridyl) butadienes have been synthesized and characterized. The effect of substitution and positional selectivity on their fluorescence and photoisomerization were systematically investigated. Among all dienes, meta‐ and para‐nitro phenyl‐substituted derivatives exhibit remarkable solvatochromic emission shifts due to intramolecular charge transfer. On the other hand, ortho derivatives undergo regioselective isomerization upon photoexcitation in contrast to inefficient isomerization of para and meta nitro‐substituted dienes. Single crystal X‐ray analysis revealed existence of intramolecular hydrogen bonding between the nitro group and the hydrogen of the proximal double bond. This restricts the rotation of the proximal double bond thereby allowing regioselective isomerization. The observations were also supported by NMR spectroscopic studies.     

Unusual mechanistic pathway for the synthesis of novel spiro-oxindoles via 3-phenyl-5-isoxazolone ring cleavage by secondary amino acids

A new approach to synthesize a series of spiro-oxindole derivatives via a multicomponent reaction of isatin, 3-phenyl-5-isoxazolone, and sarcosine or l-proline which play a dual role of base and nucleophile in methanol under reflux condition is reported. Also spiroindan-1,3-diones were synthesized from ninhydrin and 3-phenyl-5-isoxazolone. The methodology affords high yields of products in a short reaction time.