Study of transport properties co – evaporated lead telluride (PbTe) thin films

Thin films of lead telluride (PbTe) of thicknesses ranging from 1000 Å to 2500 Å have been prepared by co‐evaporation (three temperature) technique, onto precleaned amorphous glass substrates at various temperatures. The deposited samples were annealed and annealed samples were used for characterization. Resistivity of these samples was measured by four‐probe technique as a function of thickness and temperature. Activation energy for charge transport have been evaluated and found in the range of 0.09 to 0.106 eV. Thermoelectric power has been measured and found to be positive indicating that the samples are p‐type semiconducting material. Mobility variation with temperature has been estimated (evaluated) and correlated with scattering mechanism in the entire range of temperature studied. The X‐ray diffraction analysis confirmed that films are polycrystalline having cubic structure cell and lattice parameters are reported.     

Relaxation intensity in some polyacrylates

Empirical formula suggested by Kita and Koizumi for evaluation of relaxation intensity in a limited range of frequency around the relaxation frequency for the Cole-Cole type distribution has been tested for poly butyl acrylate (PBA), Poly butyl methacrylate (PBMA) and poly isobutyl methacrylate (PiBMA). The relaxation intensity Δε is expressed in terms ofε″ _M , the dielectric loss maxima andW, the frequency separation for half, two thirds or three quarters ofε″ _M , in the form Δε=ε″ _M /[(C ₁/W)+C ₂+C ₃ W], where the numerical constantsC ₁,C ₂,C ₃ are given for the respective type of relaxation.     

Nanocomposite of bimetallic nanodendrite and reduced graphene oxide as a novel platform for molecular imprinting technology

In this present work, for the first time, we are reporting a green synthesis approach for the preparation of vinyl modified reduced graphene oxide-based magnetic and bimetallic (Fe/Ag) nanodendrite (RGO@BMNDs). Herein, the RGO@BMNDs acts as a platform for the synthesis of the pyrazinamide (PZA)-imprinted polymer matrix and used for designing of the electrochemical sensor. We have demonstrated how the change in morphology could affect the electrochemical and magnetic property of nanomaterials and for this the reduced graphene oxide-based bimetallic nanoparticle (Fe/Ag) was also prepared It was found that the combination of graphene and bimetallic nanodendrites shows improvement as well as enhancement in the electrocatalytic activity and adsorption capacity, in comparison to their respective nanoparticles. The application of imprinted-RGO@BMNDs sensor was explored for trace level detection of PZA (Limit of detection = 6.65 pg L⁻¹, S/N = 3), which is a drug used for the cure of Tuberculosis. This is lowest detection limit reported so far for the detection of PZA. The sensor is highly selective, cost-effective, simple and free from any interfering effect. The real time application of the sensor was explored by successful detection of PZA in pharmaceutical and human blood serum, plasma and urine samples.     

A two-step,single pot procedure for the synthesis of substituted dihydropyrazolo-pyrimidines

In this study, we report a two-step, one pot tandem microwave-assisted reaction of 3-formylchromones with aminopyrazoles followed by a tin-free radical addition. A library of alkyl substituted dihydropyrazolopyrimidines was prepared using this new process.     

Taguchi method optimization of wax production from pyrolysis of waste polypropylene

Present research deals with the conversion of waste commodity plastics to valuable commercial product in the form of wax by pyrolysis. Optimization of both processes yield and produced wax quality was performed by means of a statistical tool originally proposed by G. Taguchi, using temperature, catalyst, carrier gas, and dwell time as the parameters. The obtained wax was characterized by Raman spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. Yield of wax was found to be maximum when the parameters were 600 °C, Fe catalyst, nitrogen gas atmosphere, and 15 min time. However, stability of the wax was found to be optimum at 700 °C. Calorific value of the wax thus obtained was ~43 MJ kg^?1, which supports its suitability as fuels like other petroleum products.     

Microwave‐Assisted Rapid Synthesis of Novel 1,5‐Benzodiazepine Derivatives as Potent Antimicrobial Agent

A new series of highly functionalized 1,5‐benzodiazepine derivatives 5a–x have been synthesized from 3‐[(1E)‐N‐(2‐aminophenyl) ethanimidoyl]‐4‐hydroxyl‐2H‐chromen‐2‐one 3a–c and pyrazole aldehyde 4a–h using catalytic amount of triflouro acetic acid under microwave irradiation. The main significant of the present procedure is shorter reaction time, easy work up procedure, and excellent yield with high purity. The structures of all the compounds were established on the basis of their IR, NMR, and mass spectral data and have been screened for their antimicrobial activity and antifungal activity.     

Applications of MALDI-MS/MS-Based Proteomics in Biomedical Research

Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) is one of the most widely used techniques in proteomics to achieve structural identification and characterization of proteins and peptides, including their variety of proteoforms due to post-translational modifications (PTMs) or protein–protein interactions (PPIs). MALDI-MS and MALDI tandem mass spectrometry (MS/MS) have been developed as analytical techniques to study small and large molecules, offering picomole to femtomole sensitivity and enabling the direct analysis of biological samples, such as biofluids, solid tissues, tissue/cell homogenates, and cell culture lysates, with a minimized procedure of sample preparation. In the last decades, structural identification of peptides and proteins achieved by MALDI-MS/MS helped researchers and clinicians to decipher molecular function, biological process, cellular component, and related pathways of the gene products as well as their involvement in pathogenesis of diseases. In this review, we highlight the applications of MALDI ionization source and tandem approaches for MS for analyzing biomedical relevant peptides and proteins. Furthermore, one of the most relevant applications of MALDI-MS/MS is to provide “molecular pictures”, which offer in situ information about molecular weight proteins without labeling of potential targets. Histology-directed MALDI-mass spectrometry imaging (MSI) uses MALDI-ToF/ToF or other MALDI tandem mass spectrometers for accurate sequence analysis of peptide biomarkers and biological active compounds directly in tissues, to assure complementary and essential spatial data compared with those obtained by LC-ESI-MS/MS technique.     

A trans influence study in propyl (aquo)cobaloxime by imidazoles and amino acids

Substitution reactions of propyl cobaloxime with imidazole, substituted imidazoles, histidine, histamine, glycine and ethyl glycine ester are carried out as a function of pH. Trends in the formation constants are explained based on the steric hindrance, extent of π-bonding and Σ-donor capacity of the incoming ligand. Molecular mechanics is used to theoretically determine the bond length and bond strain values by MM2 parametrization and these are correlated with the experimental data.