Green and Catalyst-Free Synthesis of Some New Benzo[4,5]imidazo[1,2-a]pyrimidine Derivatives as Antimicrobial and Antitubercular Agents

Russian Journal of Organic Chemistry - A new series of 4-(1H-imidazol-4-yl)-2-(substituted phenyl)-1,4-dihydrobenzo[4,5]imidazo[1,2-a]­pyrimidines have been synthesized via a one-pot reaction...     

Square Planar Platinum(II) Complexes with N,S-Donor Ligands: Synthesis,Characterisation, DNA Interaction and Cytotoxic Activity

The platinum(II) complexes with N,S-donor ligand have been synthesised and characterised by physiological techniques like elemental, electronic, Fourier transform infrared, hydrogen-1 nuclear magnetic resonance (¹H NMR) and liquid chromatography–mass spectrometry spectra. The synthesised complexes have been checked for their DNA binding ability by absorption titration and viscosity measurement, and the results show that the complexes binds to herring sperm DNA (HS DNA) via covalent mode of binding. The DNA cleavage activity of synthesised complexes has been carried out by gel electrophoresis experiment using supercoiled form of pUC19 DNA, showing the unwinding of the negatively charged supercoiled DNA. Brine shrimp (Artemia cysts) lethality bioassay technique has been applied for the determination of toxic property of synthesised complexes in terms of micromolars.     

Vibration and deflection analysis of thin cracked and submerged orthotropic plate under thermal environment using strain gradient theory

Nonlinear Dynamics - Based on a non-classical plate theory, a nonlinear analytical model is proposed to analyze transverse vibration of thin partially cracked and submerged orthotropic plate in the...     

Synthesis and characterization of ZSM-8-type zeolite crystals

Procedure for hydrothermal synthesis of ZSM-8-type zeolite crystals, using TEA—OH as a template, in the system having molar composition 16.2 (Na₂O) — Al₂O₃ — 117 (SiO₂) — 4.8 (TEA)₂O — 3887 H₂O at 170 °C is described. Results of characterization of these crystals by XRD, IR, EDAX, SEM, TGA, and adsorption studies are described and discussed. X-ray diffraction studies establish that the crystals are ZSM-8-type with structure similar to that of ZSM-5-type crystals. Crystals have prismatic bipyramidal morphology with average size 18–25 microns. Degased calcined samples adsorb xylenes in the order p > m > 0. Pore length per unit cell, estimated from n-hexane adsorption studies, is 46 Å.     

Loss of collectivity in 79Rb

High-spin states in ⁷⁹Rb were populated in the reaction at E(beam) = 60 MeV. The lifetimes of the excited states of the positive-parity yrast band and of the negative-parity band in ⁷⁹Rb were measured by the Doppler Shift Attenuation Method. The deduced transition quadrupole moments Q_t are found to have a decreasing trend with rotational frequency for both the bands, consistent with those found experimentally in neighbouring nuclei. An erratum to this article is available at .     

Experimental study of bubble departure characteristics in forced convective subcooled nucleate boiling

Visualization experiments in upward forced convective nucleate boiling flows were carried out. The bubble growth and collapse have been measured using high-speed photography technique with distilled water under atmospheric pressure. The experiments show that the bubbles depart from nucleating sites shortly after nucleation and slide along the heater surface. The bubbles grow while sliding, attain a maximum size, then lift from the surface sometime during condensation, and quickly vanish in the bulk liquid. Parametric studies show that bubble diameter and departure frequency increases with an increase in heat flux, a decrease in subcooling, and a decrease in mass flux.     

Physicochemical characterization of an Indian traditional medicine, Jasada Bhasma: detection of nanoparticles containing non-stoichiometric zinc oxide

Herbs and minerals are the integral parts of traditional systems of medicine in many countries. Herbo-Mineral medicinal preparations called Bhasma are unique to the Ayurvedic and Siddha systems of Indian Traditional Medicine. These preparations have been used since long and are claimed to be the very effective and potent dosage form. However, there is dearth of scientific analytical studies carried out on these products, and even the existing ones suffer from incomplete analysis. Jasada Bhasma is a unique preparation of zinc belonging to this class. This particular preparation has been successfully used by traditional practitioners for the treatment of diabetes and age-related eye diseases. This work presents a first comprehensive physicochemical characterization of Jasada Bhasma using modern state-of-the-art techniques such as X-ray photoelectron spectroscopy (XPS), inductively coupled plasma (ICP), elemental analysis with energy dispersive X-ray analysis (EDAX), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Our analysis shows that the Jasada Bhasma particles are in oxygen deficient state and a clearly identifiable fraction of particles are in the nanometer size range. These properties like oxygen deficiency and nanosize particles in Jasada Bhasma might impart the therapeutic property of this particular type of medicine. A. C. Joshi: Private Practitioner (Vaidya).     

Optimum oxide thickness for dye-sensitized solar cells—effect of porosity and porous size. A numerical approach

The microstructure of the metal semiconductor oxide which forms the heart of a dye-sensitized solar cell (DSSC) has proved to play a key role in the enhancement of photoelectric conversion efficiency of the cell. In this work, a numerical simulation of the system TiO₂ photo-sensitive dye of a TiO₂ DSSC focuses on the effect that the oxide porosity and the size of the pores have on the cell's performance. The steady-state numerical model used is based on the continuity and transport equations for charge species involved in the system, in connection to Poisson's equation. Light absorption coefficient is set dependent on both porosity and the size of pores in TiO₂. At a first approximation, electron mobility is considered dependent upon porosity following an iteration procedure dependent also upon local field in the oxide. An effective dielectric constant dependent upon the porosity of TiO₂, as well, is used in the model. Electron lifetime in the bulk is set dependent upon electron distribution following the iteration procedure with electron lifetime at the surface taking into consideration surface recombination. Results for different values of TiO₂ porosity and pores' size in connection to the oxide thickness are discussed and found in accordance with results reported in the literature.     

s‐Triazine‐Based Functional Discotic Liquid Crystals: Synthesis,Mesomorphism and Photoluminescence

A new series of C₃‐symmetric, π‐conjugated molecules was designed, synthesized and characterized. The materials were derived from electron‐accepting s‐triazine, appended covalently to electron‐donating styrylbenzene arms, and were readily prepared in excellent yield with high purity by means of three‐fold condensation of triphosphonate with n‐alkoxybenzaldehydes under Horner–Wadsworth–Emmons reaction conditions. Examination of the phase transitional properties by several complementary techniques evidenced self‐assembly into a hexagonal columnar phase, occurring over wide and reasonable thermal ranges. The photophysical properties were studied both in solution and in the fluid/frozen columnar states by UV/Vis absorption and photoluminescence spectroscopy. The emission spectra obtained as a function of the temperature rule out the breaking‐up of larger columns and a non‐radiative, thermally activated process. A study carried out on thin films of the glassy columnar state, which accounts for conserved fluorescence, defect‐free orientation, and freezing ionic species, with the help of atomic force microscopy (AFM) images, suggested a homogeneous granular morphology comprising fibrillar structures. Dissimilarities in the surface morphology and birefringence of thin films of the solid and frozen columnar states were clearly shown by Raman spectroscopy. An electrochemical investigation revealed a LUMO energy of ?4.0 eV. Thus, the discotic motifs presented herein meet certain criteria of organic materials, which are essential for developing electronic devices.