Nano-structured nickel oxide based DNA biosensor for detection of visceral leishmaniasis (Kala-azar)

Sol-gel synthesized nickel oxide (NiO) film deposited onto indium tin oxide (ITO) coated glass plate has been utilized for the development of sensitive and stable DNA biosensor and demonstrated for diagnosis of visceral leishmaniasis also known as Kala-azar. Leishmania specific sensor is developed by immobilizing 23mer DNA sequence (oligonucleotide) identified from 18S rRNA gene sequences from Leishmania donovani. Characterization studies like X-Ray Diffraction and Scanning Electron Microscopy revealed the formation of nano-structured NiO, while immobilization of single strand (ss)-DNA of Leishmania was supported by UV-visible, Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy techniques. Response studies of ss-DNA/NiO/ITO bioelectrode are carried out using differential pulsed voltammetry in presence of methylene blue redox dye as a redox mediator. A linear response is obtained in the wide concentration range of 2 pg ml(-1) to 2 μg ml(-1) of complementary target genomic DNA (disease DNA) within the variation of 10% for 5 sets of studies. The observed results hold promise not only for diagnosis of Kala-azar patients but also hold enormous potential of the nano-NiO based probe for development of stable and sensitive biosensors.     

Nonlinear breaking of waves in an electrically conducting and radiating gas

The effects of radiative transfer are treated by the use of a differential approximation which is valid over the entire optical depth range from the transparent limit to the optically thick limit. The singular surface theory is used to determine the modes of wave propagation and to evaluate the behaviour at the wave head. It is shown that there are two modes of wave propagation namely (i) the radiation induced waves which are always damped, and (ii) the modified magnetogasdynamic waves which break at the wave front if the initial discontinuity is sufficiently strong. The effects of thermal radiation, the magnetic field intensity, the finite electrical conductivity and the initial wave front curvature on the non-linear breaking of modified magnetogasdynamic waves are discussed.

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Zusammenfassung Der Einfluß der Strahlung wird mit Hilfe von Differential-Näherungen behandelt, die im ganzen Bereich von optischen Tiefen Gültigkeit haben, von der Transparenz bis zur optisch dicken Grenze. Die Theorie singulärer Flächen wird benützt um die Wellenausbreitung und das Verhalten an der Wellenfront zu behandeln. Es wird gezeigt, daß es zwei Formen von Wellenausbreitung gibt, nämlich (i) Wellen erzeugt durch Strahlung, die immer gedämpft sind, und (ii) die modifizierte magnetogasdynamische Welle, die an der Front immer bricht, wenn die ursprüngliche Diskontinuität stark genug ist. Es werden die Einflüsse der Wärmestrahlung, der magnetischen Feldstärke, der endlichen elektrischen Leitfähigkeit und der ursprünglichen Wellenkrümmung auf die nicht-lineare Frontbildung untersucht.

     

Nitro group participation in the formation of heterocycles

Benzoyl bromide (2-nitrophenyl) hydrazone (2) was treated with sodium ethoxide and ethyl cyanoacetate and two unexpected products were obtained. These products were ultimately shown to be 6-bromo-3-phenyl-1,2,4-benzotriazine (32) and 5-bromo-2-phenylbenzoxazole (38), by comparison with authentic samples which were synthesized. A mechanism is presented for the formation of these two heterocyclic systems (32 and 38) from 2.     

Chalcones XI: Potential Germicides Derived from Acetyl Phenanthrenes and Acetophenones

Thirteen phenanthryl and biphenylyl chalcones have been synthesized in presence of saturated solution of Na in methanol to evaluate their germicidal activity against gram +ve and ?ve bacteria.     

Fast atom bombardment positive-ion mass spectra of 1,2,2-tris(sulfonyl)hydrazines

Several 1,2,2-tris(sulfonyl)hydrazines, conceived as prodrugs of 1,2-bis(sulfonyl)hydrazines and synthesized as potential antineoplastic and trypanocidal drugs, were analyzed by mass Spectrometry as part of the confirmation of the structure of these compounds. Since these compounds showed activity against several transplanted animal tumors, an understanding of the mass spectral behavior of these agents is important to gain information should clinical trials and metabolic studies be undertaken. In all spectra, protonated molecular ions were observed. Collision activation resulted in considerable fragmentation in the fast atom bombardment spectra. Rearrangement ions formed by elimination of substituted diimides from the middle of the molecule were observed. Other rearrangements involving the alkyl substituent and sulfonyl oxygen also occurred.     

Absence of neutron emission during interaction of deuterium with metal at low energies

Technique and instrumentation to detect reliably, multiplicity of neutrons emitted in sharp bursts (≤100 μs) has been developed where a burst of as low as 15 neutrons and continuous emission of ⋍10⁻¹ neutron/s may be detected. Using this technique, attempts were made to detect neutron emission from various experiments in which anomalous nuclear effects (or what is commonly referred to as cold fusion) may be expected to occur. No neutrons, above our detection threshold, were detected in the recent series of experiments.     

Comparison of methods for numerical differentiation

Numerical differentiation can uncover hidden features in chemical data, but the limitations of the technique used should be understood. A method based on fitting data to a quadratic polynomial gives good signal-to-noise ratios, but systematically low derivative intensities. Central difference methods are more accurate but less tolerant of noise.     

Electrical transport in bulk amorphous selenium

D.C. conductivity measurements have been made as a function of temperature and external electric field on bulk amorphous selenium. A decrease in the activation energy with increase of electric field has been observed. This has been interpreted in terms of a mixed, thermally activated and trap limited conduction process.