Synthesis of indole based novel small molecules and their in vitro anti-proliferative effects on various cancer cell lines

Indole based novel small molecules were designed as potential anticancer agents. Multi step synthesis of these compounds was carried out by using Pd/C–Cu mediated coupling–cyclization strategy as a key step. The single crystal X-ray diffraction study was used to confirm the molecular structure of a representative compound unambiguously. Many of these compounds were evaluated for their anti-proliferative properties in vitro against six cancer cell lines as well as noncancerous cells. All these compounds showed selective growth inhibition of cancer cells and several of them were found to be promising with IC₅₀ values in the range of 0.1–1.2 μM, comparable to the known anticancer drug doxorubicin.     

Reabsorption in a neodymium fibre laser

Resonance absorption, the reabsorption of laser light by the laser transition of the dopant material itself, is found to be the limiting factor for fibre lasers when extremely long fibres are used. We report on measurements of the temperature dependence of the losses in a 8.5 m long commercial Nd³⁺ doped fibre (York, ND 95020/E). To determine the reabsorption losses, the threshold power has been measured as a function of temperature between 243 K and 413 K. The results are compared with theory assuming a ⁴l level energy of 2110 cm^-1 and an absorption cross-section of δ = 1.15 x 10^-20cm². The comparison shows that reabsorption from the thermally populated ⁴l level is the dominant contribution to the measured losses.     

Radiative strength functions in odd-A spherical nuclei

The radiative strength functions for the partial γ-transitions from neutron resonances to the ground and low-lying states of odd-A spherical nuclei are calculated within the quasiparticle-phonon nuclear model. The fragmentation of one-quasiparticle and quasiparticle-plus-phonon states is calculated. This allowed one to calculate γ-transitions between the one-quasi-particle components (valence transitions) and γ-transitions between the quasiparticle-plus-phonon and one-quasiparticle components of the wave functions. The energy dependence of the strength functions $\text{C}$(E1, η) and $\text{C}$(M1, η) is calculated near the neutron binding energy B_n for ⁵⁵Fe and ^{59, 61}Ni. The corresponding experimental data are described qualitatively. The contribution of the valence E1 transitions to the strength function is shown to be from 20% to 90%, and M1 transitions about 1%. The influence of the M1 giant resonance is important for M1 transition probabilities.     

Diffuse reflectance infrared Fourier transform study of NO(x) adsorption on CGO10 impregnated with K2O or BaO

In the present work diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy is applied to study the adsorption of NO(x) at 300-500 °C in different atmospheres on gadolinium-doped ceria (CGO), an important material in electrodes investigated for electrochemical NO(x) removal. Furthermore, the effect on the NO(x) adsorption when adding K(2)O or BaO to the CGO is investigated. The DRIFT study shows mainly the presence of nitrate species at 500 °C, whereas at lower temperature a diversity of adsorbed NO(x) species exists on the CGO. The presence of O(2) is shown to have a strong effect on the adsorption of NO, but no effect on the adsorption of NO(2). Addition of K(2)O and BaO dramatically affects the NO(x) adsorption and the results also show that the adsorbed NO(x) species are mobile and capable of changing adsorption state in the investigated temperature range.     

Coevolution of strategy and structure in complex networks with dynamical linking

We introduce a model in which individuals differ in the rate at which they seek new interactions with others, making rational decisions modeled as general symmetric two-player games. Once a link between two individuals has formed, the productivity of this link is evaluated. Links can be broken off at different rates. We provide analytic results for the limiting cases where linking dynamics is much faster than evolutionary dynamics and vice versa, and show how the individual capacity of forming new links or severing inconvenient ones maps into the problem of strategy evolution in a well-mixed population under a different game. For intermediate ranges, we investigate numerically the detailed interplay determined by these two time scales and show that the scope of validity of the analytical results extends to a much wider ratio of time scales than expected.     

Study of alternating current conduction mechanism in polypyrrole-magnesium ferrite hybrid nanocomposite through correlated barrier hopping model

In the present work, both polypyrrole (PPy) and optimized polypyrrole–magnesium ferrite (PPy-MgFe₂O₄) hybrid nanocomposite were synthesized separately by simple oxidative chemical polymerization method and then structurally characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The FTIR spectrum of the composite showed the presence of characteristic absorption bands of both PPy and MgFe₂O₄ in the composite confirming interfacial interaction of PPy with MgFe₂O₄. That this interaction is not affected by crystalline behaviour of predominant MgFe₂O₄ particles but that MgFe₂O₄ has embedded in PPy matrix was confirmed by XRD studies. Agglomerated granular spherical morphology of the composite was confirmed by SEM studies. Decrease in AC conductivity of the composite as compared to PPy due to the formation of interfacial heterojunction barrier between p-type PPy and n-type MgFe₂O₄ was confirmed experimentally and well supported theoretically by calculating binding energy, hopping distance and density of states at Fermi level of PPy and the composite as per CBH model.     

3-Oxy-5-phenyl-1<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazole-4-carboxylic Acid. Synthesis,Structure, and Properties

The structure of 3-oxy-5-phenyl-1H-1,2,3-triazole-4-carboxylic acid was determined both experimentally (by the X-ray diffraction method) and by quantum-chemical calculations. Alkylation of 3-oxy-5-phenyl-1H-1,2,3-triazole-4-carboxylic acid (as crystal hydrate) with methyl iodide, depending on the reactant ratio, gives 1-methoxy-4-phenyl-1H-1,2,3-triazole-5-carboxylic acid and methyl 1-methoxy-4-phenyl-1H-1,2,3-triazole-5-carboxylate. Nitration of the title compound under mild conditions occurs at the 5-phenyl group with formation of meta-nitro derivative, while under more severe conditions 3,5-dinitrobenzoic acid is obtained. 3-Oxy-5-phenyl-1H-1,2,3-triazole-4-carboxylic acid was also converted into the corresponding acid chloride and substituted amide.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 4, 2005, pp. 601–608.Original Russian Text Copyright © 2005 by Shtabova, Shaposhnikov, Mel’nikova, Tselinskii, Nather, Traulsen, Friedrichsen.     

Surface species in the direct amination of methanol over Brønsted acidic mordenite catalysts

Quantitative in situ infrared spectroscopy in combination with kinetic analysis is utilized to derive mechanistic aspects for the reaction of methanol with ammonia on Brønsted acidic mordenite. Under non-reactive conditions, a coadsorption complex between methanol and ammonia is found, in which only ammonia is in direct interaction with the Brønsted acid sites of the zeolite. This complex is proposed to be the precursor for the formation of protonated methylamines in the zeolite pores which are formed in sequential order up to tetramethylammonium ions. These methylamines are unable to desorb under reaction conditions in the absence of ammonia. They leave the surface either by ammonia adsorption assisted desorption or by scavenging of methyl groups from protonated methylamines by ammonia. Both steps are concluded to be potentially rate determining.     

A Stability Analysis of Convolution Quadraturea for Abel-Volterra Integral Equations

We investigate the stability properties of numerical methodsfor weakly singular Volterra integral equations of the secondkind. Our theory extends the stability theory of linear multistepmethods for ordinary differential equations. We introduce theconcepts of A-stability, A()-stability etc. for Abel-Volterraequations. The stability region is characterized in terms ofthe weights of the method. It is shown that the order of anA-stable convolution quadrature cannot exceed 2. Further westudy the stability properties of implicit Adam methods, withparticular emphasis on the question of A()-stability.