Design and Development of a Non-Enzymatic Electrochemical Biosensor for the Detection of Glutathione

Glutathione (GSH-reduced form) is a tripeptide that plays a vital role as an antioxidant to remove xenobiotics in the human body and changes in GSH levels are a marker for the progression of various diseases. In this context, a highly sensitive non-enzymatic electrochemical biosensor for the detection of GSH has been developed using reduced graphene oxide Manganese oxide (rGMnO) nanocomposite as the nano-interface. Initially, graphene oxide was synthesized by Hummer's method and then thermally reduced in the presence of MnO₂ in a blast furnace to obtain rGMnO nanocomposite. The nanocomposite was characterized to validate its structure and morphological properties via Scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman, and X-ray photoelectron spectroscopy (XPS). Cyclic voltammetry and amperometry studies showed that upon the addition of GSH, the Pt/rGMnO modified working electrode exhibited a linear response in the range of 1–100 μM at an input voltage of −0.62 V. The developed sensor was found to have a sensitivity of 0.3256 μA μM⁻¹ and LOD of 970 nM with a recovery of 92–104 % in real blood serum samples.     

Influences of stoichiometry on steadily propagating triple flames in counterflows

Most studies of triple flames in counterflowing streams of fuel and oxidizer have been focused on the symmetric problem in which the stoichiometric mixture fraction is 1/2. There then exist lean and rich premixed flames of roughly equal strengths, with a diffusion flame trailing behind from the stoichiometric point at which they meet. In the majority of realistic situations, however, the stoichiometric mixture fraction departs appreciably from unity, typically being quite small. With the objective of clarifying the influences of stoichiometry, attention is focused on one of the simplest possible models, addressed here mainly by numerical integration. When the stoichiometric mixture fraction departs appreciably from 1/2, one of the premixed wings is found to be dominant to such an extent that the diffusion flame and the other premixed flame are very weak by comparison. These curved, partially premixed flames are expected to be relevant in realistic configurations. In addition, a simple kinematic balance is shown to predict the shape of the front and the propagation velocity reasonably well in the limit of low stretch and low curvature.     

Generation of sub wavelength super long dark channel using azimuthally polarized annular multi-Gaussian beam

We investigate the interesting focal properties of phase modulation azimuthally polarized annular multi Gaussian beam employing a high numerical aperture (NA) lens on the basis of vector diffraction theory. We observe that our proposed system generates a sub wavelength focal hole of \(0.43 \uplambda \) having large uniform focal depth of \(84 \uplambda \) . This kind of nondiffracting focal hole is called dark channel, which may have applications in atom optical experiments, such as with atomic lenses, atom traps, and atom switches.     

Indium bromide catalysed, ultrasound-assisted, regio-selective synthesis of ethyl-5-(trifluoromethyl)-1-(3-substituted-isoquinolin-1-yl)-1H-pyrazole-4-carboxylates

A series of pyrazole-4-carboxylates have been synthesised using indium bromide catalyst and the cyclisation of respective 3-substituted-isoquinolinylhydrazines 1 into their corresponding ethyl-2-(ethoxymethylene)-4,4,4-trifluoro-3-oxobutanoates 3 in ethanol solvent under ultrasonic irradiation at 90?°C for 30 min. The regio-selective cyclisation products were efficiently provided by indium bromide catalyst and are confirmed by nuclear Overhauser effect spectroscopy?Cnuclear magnetic resonance (NOESY?CNMR) studies.     

An efficient 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU)-mediated synthesis of 5-(trifluoromethyl)-N-alkyl-1-(3-phenylisoquinoline-1-yl)-1H-pyrazole-4-carboxamides

A series of 5-(trifluoromethyl)-N-alkyl-1-(3-phenylisoquinoline-1-yl)-1H-pyrazole-4-carboxamides 4 has been effectively achieved in high yield and purity from the reaction of pyrazole carboxylic acid 2 with amines 3 in the presence of TBTU as a catalyst and diisopropyl ethylamine as a base in acetonitrile at room temperature.     

Recent developments in the use of metal oxides for photocatalytic degradation of pharmaceutical pollutants in water—a review

In recent years, metal oxide semiconductors have been explored as photocatalysts for the degradation of organic contaminants in water/wastewater. The uniqueness of these oxide materials is in their ability to harness energy in the UV/Vis range, their relative ease of synthesis, low cost, and their general high surface ratio to mass, etc. Thus, these materials have consequently drawn much profound interest in environment applications, particularly pharmaceutical drugs for photocatalytic degradation. Furthermore, the non-toxic nature of most metal oxide semiconductors means they are convenient for water treatment works, resulting in safe drinking water for humans and safe environments for aquatic mammals. Pharmaceuticals are emerging pollutants that are increasingly being found in water systems. They have been detrimental to the human and animal health. In this article, pharmaceutical drugs abatement from water via photocatalysis process using oxide-based advanced metals such as TiO₂, ZnO, Fe₂O₃,WO₃, and Bi₂WO₆ is discussed. Degradation of various drugs at laboratory scale have been assessed and examples cited. Various approaches to metal oxides modifications and synthesis methods to improve degradation efficiency have also been discussed. Effects of experimental/operational parameters in the degradation process have been compiled and compared. Finally, a short preview of degradation of pharmaceuticals pilot scales is also highlighted.     

Nonlinear vibrations of a fluid-filled,soft circular shell: experiments and system identification

Nonlinear Dynamics - Vibration experiments are carried out on a slightly corrugated circular cylindrical shell made of polyethylene terephthalate fabric. The shell is liquid-filled, it is...     

Constrained melting of graphene-based phase change nanocomposites inside a sphere

Journal of Thermal Analysis and Calorimetry - In the present work, the melting behavior of a fatty acid-based phase change material (PCM) with the addition of functionalized graphene nanoplatelets...     

Effect of thermostatic expansion valve tuning on the performance enhancement and environmental impact of a mobile air conditioning system

Journal of Thermal Analysis and Calorimetry - In this work, the performance enhancement of a HFO-1234yf mobile air conditioning (MAC) system with a suction/liquid line heat exchanger (SLHX) was...     

Highly active human-hair-supported noble metal (Ag or Ru) nanocomposites for rapid and selective reduction of p-nitrophenol to p-aminophenol

Research on Chemical Intermediates - Highly efficient nanocomposites (Ag/HHP and Ru/HHP) of Ag and Ru nanoparticles (NPs) supported on human hair powder (HHP) were prepared for reduction of...