Borenium cations derived from BODIPY dyes

Fluoride abstraction from a BODIPY dye gives a well defined borenium ion which can be converted to a borenium hydride via treatment with DIBAL-H.     

Blue fluorescent 4a-Aza-4b-boraphenanthrenes

[structure: see text]. Phenanthrene analogues with internalized B-N moieties were found to afford blue light emission with good quantum efficiencies, whereas the isomeric species with peripheral B-N moieties displayed only UV emission behavior, like the all-carbon framework.     

Comparative study of MIRD,experimental and GEANT4 simulations for uniformly distributed I-131 in cylindrical and spherical thyroid models

Due to worldwide use of I-131 for the treatment of benign and malignant thyroid diseases, reliable dose estimation for various thyroid mass values is necessary. In this study computation of the radiation absorbed dose due to β- and γ-activity of I-131 to thyroid has been carried out using the GEANT4 code for water, ICRP and ICRU soft tissues simulating thyroid tissue. The results are validated by comparison with the MIRD calculations. The effect of size and shape of thyroid on absorbed dose has also been studied by varying the volume of thyroid in 10–150 cm³ range and by using spherical and cylindrical models for thyroid. Experimental measurements have also been performed using a group of 20 patients, who were treated for thyro-toxicosis with I-131. Dose equivalent was measured with a portable ionization chamber after the administration of 405–851 MBq of I-131. Comparison of peak energy and effective energy per transformation with the MIRD has been performed yielding only 0.5% relative differences between these two energies. For spherical model, the relative difference of peak and effective energies with the MIRD is 5.2% and 4.7% respectively and very similar for cylindrical models. Spherical model shows 0.45% increase as compared to that of cylindrical model. The use of water, ICRP or ICRU materials only implies negligible difference. Total energy deposition per decay of I-131 increases with volume for both models. The estimated results of spherical and cylindrical thyroid models show an excellent agreement with the corresponding the MIRD results. Simulated results for ambient dose equivalent rate show a good agreement with our experiment and corresponding errors remain less than 13% in the case of dose at 1 m, and are less than 8% for doses at the neck surface.     

Soil water redistribution and extraction flow models: Conservation laws

We determine all the nontrivial conservation laws for soil water redistribution and extraction flow equations which are modelled by a class of (2+1) nonlinear evolution partial differential equations with three arbitrary elements. It is shown that for arbitrary elements in the model equation there exist trivial conservation laws. We point out that nontrivial conservation laws exist for certain classes of equations which admit point symmetries.     

Synthesis,crystal structure of some new 2‐(4‐methylbenzoylimino)‐3‐aryl‐4‐methyl‐1,3‐thiazolines

An efficient, straightforward synthesis of some new 2‐(4‐methylbenzoylimino)‐3‐aryl‐4‐methyl‐1,3‐thiazolines ( 2a‐i ) is described. The methodology involves the cyclization of 1‐(4‐methylbenzoyl)‐3‐arylthioureas with acetone in the presence of bromine and triethylamine. The structures were confirmed by spectroscopic data, elemental analyses and in one case ( 2i ) by the single crystal X‐ray diffraction data.     

Symmetry reductions,exact solutions and conservation laws of a new coupled KdV system

Lie symmetry analysis is performed on a new coupled KdV system, which arises in the analysis of various problems in theoretical physics and many scientific applications. The similarity reductions and new exact solutions are obtained. The solutions obtained include the solitary waves, cnoidal and snoidal waves. In addition, we derive the conservation laws of the coupled KdV system.     

Microwave assisted synthesis of 3-benzazepin-2-ones as building blocks for 2,3-disubstituted tetrahydro-3-benzazepines

Microwave assisted condensation of primary amines with keto acids 1a–c provided directly 3,4-disubstituted 1,3-dihydro-3-benzazepin-2-ones 2. Whereas small amine size, such as NH₃ afforded high yields of secondary lactams 2a, 2d, and 2g, primary amines with larger substituents in α-position led to lower yields of 2 or even to regioisomeric indanone derivatives 4. However, subsequent alkylation of 2a, 2d, and 2g with various alkyl halides provided the corresponding N-substituted 3-benzazepin-2-ones 2 in good yields. Hydrogenation of 2 followed by BH₃ reduction led to 3-benzazepines 9. 3-Benzyl-2-methyl-2,3,4,5-tetrahydro-1H-3-benzazepine (9c) reveals high σ₁ affinity and selectivity over σ₂ and NMDA receptors.     

An Improved Study of Electronic Band Structure and Optical Parameters of X-Phosphides (X=B,Al, Ga,In) by Modified Becke-Johnson Potential

We report the electronic band structure and optical parameters of X-Phosphides (X=B, Al,Ga,In) by first-principles technique based on a new approximation known as modified Becke-Johnson (mBJ). This potential is considered more accurate in elaborating excited states properties of insulators and semiconductors as compared to LDA and GGA. The present calculated band gaps values of BP, AlP, GaP, and InP are 1.867 eV, 2.268 eV, 2.090 eV, and 1.377 eV respectively, which are in close agreement to the experimental results. The band gap values trend in this study is as: Eg (mBJ-GGA/LDA)Eg (GGA) Eg (LDA). Optical parametric quantities (dielectric constant, refractive index, reflectivity and optical conductivity) which based on the band structure are also presented and discussed. BP, AlP, GaP, and InP have strong absorption in between the energy range 4-9eV, 4-7eV, 3-7eV, and 2-7eV respectively. Static dielectric constant, static refractive index and coefficient of reflectivity at zero frequency, within mBJ-GGA, are also calculated. BP, AlP, GaP, and InP show significant optical conductivity in the range 5.2-10eV, 4.3-8eV, 3.5-7.2eV, and 3.2-8eV respectively. The present study endorses that the said compounds can be used in opto-electronic applications, for different energy ranges.     

Self-dual Yang-Mills equations in split signature

We study the self-dual Yang-Mills equations in split signature. We give a special solution, called the basic split instanton, and describe the ADHM construction in the split signature. Moreover a split version of t'Hooft ansatz is described.