Computer simulation of proton channelling in silicon

The channelling of 3 MeV protons in the 〈110〉 direction of silicon has been simulated using Vineyard model taking into account thermally vibrating nuclei and energy loss due to ion-electron interactions. A beam made up of constant energy particles but with spatial divergence has been simulated for the purpose. The values of the minimum scattering yield and half width of the channelling dip are shown to be depth sensitive and agree well with the measured values. The dependence of yield on the angle of incidence has been found to give information of all three types of channelling. The critical angles for the three types of channelling and wavelength of planar oscillations are consistent with the previous calculations.     

Duality for Coloured Quantum Groups

Duality between the coloured quantum group and the coloured quantum algebra corresponding to GL(2) is established. The coloured L ^± functionals are constructed and the dual algebra is derived explicitly. These functionals are then employed to give a coloured generalisation of the differential calculus on quantum GL(2) within the framework of the R-matrix approach.     

Multifunctional polymers as multi-role materials for photonics

Multifunctional polymers can play multi-roles such as laser light source, passive interconnects, optical signal processing and optical data storage in the development of photonics technology. In this paper, two approaches to achieve nanostructure control to introduce multifunctionality at both molecular and bulk levels are presented. A novel concept of multiphasic nanostructured composites is discussed. Various applications of a specific multifunctional property introduced by strong two-photon absorption and efficient fluorescence are presented. The combined action of these two functions produces upconverted emission. Specific applications discussed are upconversion lasing, optical data storage, confocal microscopy, and photodynamic therapy.     

Structural transformation of MoO<Subscript>3</Subscript> nanobelts into MoS<Subscript>2</Subscript> nanotubes

The structural transformation of MoO₃ nanobelts into MoS₂ nanotubes using a simple sulfur source has been reported. This transformation has been extensively investigated using electron microscopic and spectroscopic techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), electron diffraction (ED), and energy-dispersive X-ray analysis (SEM-EDAX and TEM-EDX). The method described in this report will serve as a generic route for the transformation of other oxide nanostructures into the chalcogenide nanostructures.     

2‐[(E)‐(4‐Chloro­phenyl)­methyl­ene­amino]‐N‐(X‐methyl­phenyl)‐4,5,6,7‐tetra­hydro‐1‐benzo­thio­phene‐3‐carbox­amide,where X = 2 and 3

The title compounds, both C₂₃H₂₁ClN₂OS, are isomeric, with (I) and (II) being the N‐3‐methyl­phenyl and N‐2‐methyl­phenyl derivatives, respectively. The dihedral angle between the 4‐chloro­phenyl group and the thio­phene ring in (II) [38.1 (1)°] is larger than that in (I) [7.1 (1)°], indicating steric repulsion between the chloro­phenyl and o‐toluidine groups in (II). In both compounds, an intramolecular N—H⋯N hydrogen bond forms a pseudo‐six‐membered ring, thus locking the molecular conformation. In the crystal structures, mol­ecules are connected via N—H⋯O hydrogen bonds, forming chains along the b axis in (I) and along the c axis in (II). Intermolecular C—H⋯O/S and π–π interactions are also observed in (II), but not in (I).     

Pd-catalyzed synthesis of α-aryl ketones through couplings of α-arylacetyl chlorides with triarylbismuths as multi-coupling nucleophiles

The cross-coupling reaction of α-arylacetyl chlorides with triarylbismuths was studied under Pd-catalyzed conditions. The reaction was found to be facile under the established protocol and furnished high yields of α-aryl ketones in short reaction times. This work also demonstrated a facile synthesis of various regio-isomeric mono-, di- and tri-substituted α-aryl ketones in high yields. Triarylbismuths were employed as sub-stoichiometric multi-coupling organometallic nucleophiles in this coupling protocol.     

Crystal Structure Studies of Two Regioisomers of Bromo-4-Aryloxymethylcoumarins

Abstract  

The 4-(2-bromo-4-methyl-phenoxymethyl)-6-methylcoumarin (1) have been synthesized from bromination of corresponding 4-aryloxymethyl coumarin, which is a regioisomer of 4-(2-bromo-4-methyl-phenoxymethyl)-7-methylcoumarin (2) (CCDC-695895). The compound 1 crystallizes with triclinic space group P-1, a = 8.0943(3) ?, b = 9.3502(3) ?, c = 10.1476(4) ?, α = 90.234(2)°, β = 94.065(2)°, γ = 95.106(2)°, Z = 2 and compound 2 crystallizes with monoclinic space group P2₁/n, a = 8.465(5) ?, b = 13.649(5) ?, c = 13.304(5) ?, α = 90.000(5)°, β = 90.740(5)°, γ = 90.000(5)°, Z = 4. Both the compounds are planar with variation in their intermolecular hydrogen bonds between C–H···O and C–H···π.     

Automata and logics over finitely varying functions

We extend some of the classical connections between automata and logic due to Büchi (1960) [5] and McNaughton and Papert (1971) [12] to languages of finitely varying functions or “signals”. In particular, we introduce a natural class of automata for generating finitely varying functions called ’s, and show that it coincides in terms of language definability with a natural monadic second-order logic interpreted over finitely varying functions Rabinovich (2002) [15]. We also identify a “counter-free” subclass of ’s which characterise the first-order definable languages of finitely varying functions. Our proofs mainly factor through the classical results for word languages. These results have applications in automata characterisations for continuously interpreted real-time logics like Metric Temporal Logic (MTL) Chevalier et al. (2006, 2007) [6] and [7].     

An extensive study on isosorbide-5-mononitrate acid adducts for quantification in human plasma using liquid chromatography/electrospray ionization tandem mass spectrometry and its application to bioequivalence sample analysis

A rapid and sensitive liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) method for the determination of isosorbide-5-mononitrate (5-ISMN), used in the treatment of angina pectoris, in human plasma is described. The quantification of 5-ISMN was performed via stable acetate adduct formation with a high relative abundance. The plasma filtrate obtained after solid-phase extraction (SPE), using a polymer based, hydrophilic-lipophilic balanced (HLB) cartridge, was submitted directly to reversed-phase high-performance liquid chromatography separation followed by ESI and detection of the resulting ions using triple-quadrupole mass spectrometry in selected reaction monitoring (SRM) mode. There was no significant matrix effect on the analysis. For validation of the method, the recovery of the free analyte response was compared to that obtained from an optimized extraction method. The analyte stability was examined under conditions mimicking the sample storage, handling, and analytical procedures. The extraction procedure yielded extremely clean extracts with a recovery of 95.51% and 93.98% for iossorbide-5-mononitrate and topiramate (internal standard (IS)), respectively. The calibration curves were linear for the dynamic range of 10.0 to 1000.0 ng/mL with a correlation coefficient r > or = 0.9985. The intra-assay and inter-assay precision for the samples at the lower limit of quantification (LLOQ) were 9.02 and 13.30%, respectively. The intra-assay accuracies at LLOQ, LQC, MQC and HQC levels varied from 98.13 to 118.15, 102.34 to 105.21, 100.69 to 109.68, and 95.76 to 102.92%, respectively, while the inter-assay accuracies ranged from 93.10 to 118.15, 93.03 to 107.04, 86.97 to 109.68 and 86.18 to 105.85%, respectively, at these levels. The method is rugged and fast with a total run time of 2 min. The method was successfully applied for a bioequivalence study in 24 human subject samples after oral administration of 60 mg extended release (ER) formulations.