Explaining GRB in the light of energy deposition rate for v+ [`(n)] \bar \nu → e+ + e? in a compact star

We have studied the v+ $ \bar \nu $ \bar \nu → e ⁺ + e ⁻ energy deposition rate near a rotating compact star which is important for the study of gamma ray bursts (GRB). The General relativistic (GR) and rotational effects increase the efficiency of the process immensely. The rotational effect also brings about an asymmetry in the deposition rate of the star.     

Study of disorder-order transitions in FexAl1−x binary alloys using the augmented space recursion based orbital peeling technique

In this communication we propose a method for the study of disorder-order transitions in Fe_xAl_1−x binary alloys. We turn to our earlier development [1] of a combination of the recursion method introduced by Haydock et al. [2] and our augmented space approach [3] with the orbital peeling technique proposed by Burke [4] to determine the small energy differences required in obtaining the pair energies which go as input to the generalized perturbation technique [5] of studying disorder-order transitions.     

Uniqueness and set sharing of derivatives of meromorphic functions

We prove some uniqueness theorems concerning the derivatives of meromorphic functions when they share two or three sets which will improve some existing results.     

Advances in top-down and bottom-up surface nanofabrication: techniques, applications & future prospects

This review highlights the most significant advances of the nanofabrication techniques reported over the past decade with a particular focus on the approaches tailored towards the fabrication of functional nano-devices. The review is divided into two sections: top-down and bottom-up nanofabrication. Under the classification of top-down, special attention is given to technical reports that demonstrate multi-directional patterning capabilities less than or equal to 100 nm. These include recent advances in lithographic techniques, such as optical, electron beam, soft, nanoimprint, scanning probe, and block copolymer lithography. Bottom-up nanofabrication techniques--such as, atomic layer deposition, sol-gel nanofabrication, molecular self-assembly, vapor-phase deposition and DNA-scaffolding for nanoelectronics--are also discussed. Specifically, we describe advances in the fabrication of functional nanocomposites and graphene using chemical and physical vapor deposition. Our aim is to provide a comprehensive platform for prominent nanofabrication tools and techniques in order to facilitate the development of new or hybrid nanofabrication techniques leading to novel and efficient functional nanostructured devices.     

Production and characterization of biosurfactant from marine Streptomyces species B3

The present study demonstrates the production and properties of a biosurfactant isolated from marine Streptomyces species B3. The production of the biosurfactant was found to be higher in medium containing sucrose and lower in the medium containing glycerol. Yeast extract was the best nitrogen source for the production of the biosurfactant. The isolated biosurfactant reduced the surface tension of water to 29 mN/m. The purified biosurfactant was shown critical micelle concentrations of 110 mg/l. The emulsifying activity and stability of the biosurfactant was investigated at different salinities, pH, and temperature. The biosurfactant was effective at very low concentrations over a wide range of temperature, pH, and salt concentration. The purified biosurfactant was shown strong antimicrobial activity. The biosurfactant was produced from the marine Streptomyces sp. using non-hydrocarbon substrates such as sucrose that was readily available and not required extensive purification procedure. Streptomyces species B3 can be used for microbially enhanced oil recovery process.     

Synthesis, characterization, and DNA binding of the biologically relevant novel cationic molybdenum(VI)–glutathione complex [Mo(GS)(Cl)(H2O)]Cl2

Abstract  

The complex [Mo(GS)(Cl)(H₂O)]Cl₂ (MoG) was synthesized in aqueous medium and its composition has been determined by elemental and thermogravimetric analysis. Binding modes were determined by ¹H NMR, ¹³C NMR, mass, and FT-IR spectrometry. The molecular formula was confirmed by mass spectral analysis. The molecular weight of the complex determined by the Rast camphor method also supports the formulation M _r = 525. This molecular formula demands the compound to be a 1:2 electrolyte, which is also supported by the conductance measurement, its value being 210 Ω⁻¹ cm². The compound is found to be diamagnetic, indicating that the molybdenum is in the +6 oxidation state (d⁰). The binding of MoG with calf thymus DNA was studied by spectroscopic titration. The interaction ratio was determined by monitoring the DNA 260 nm band as well as the S → Mo LMCT band of the complex observed at 225 nm. The interaction ratio calculated from the above studies was found to be 1:0.70 (DNA:MoG) in both cases, while the binding constant of DNA–MoG was found to be (4.8 ± 0.5) × 10⁵ M⁻¹. The binding constant data indicate that the binding nature is intercalative.     

Studies on the ring opening reactions of 3-oxa-1-azabicyclo[3.1.0]hexan-2-ones. Synthesis of aminomethyl oxazolidinones and aziridinyl ureas

The reaction of fused ring aziridines, 3-oxa-1-azabicyclo[3.1.0]hexan-2-ones, with amine nucleophiles can provide either an aminomethyl oxazolidinone or an aziridinyl urea. The amine, reaction solvent, and aziridine substitution have been examined with the aid of computational studies to identify reaction conditions that provide a single product. Polar solvents provided only the aminomethyl oxazolidinone products. Formation of aziridinyl ureas required control of aziridine substitution, solvent, and reactant stoichiometry.     

Synthesis of a novel analytical reagent for the determination of active sites for conjugation on a catalytic aldolase monoclonal antibody

An optimized and scalable synthesis of a novel analytical reagent for the determination of the number of active sites available for conjugation on a catalytic aldolase monoclonal antibody (mAb) is described. The original conditions suffered from lack of reproducibility, incomplete reactions, and required several chromatographies and lyophilizations that afforded material of low purity. A redesigned route and optimized protocols have been developed that eliminate the use of toxic and unsafe reagents such as HMPA and HATU. In addition, the number of chromatographies has been reduced to only one and time-consuming and energy-intensive lyophilizations are no longer required. The overall yield has been considerably improved from the original 4% to 20% after telescoping the last two steps of the synthesis and this new approach allowed for the preparation of material with higher chemical purity (?99% vs the initial 90%) to meet specifications.     

Graphene oxide-based supramolecular hydrogels for making nanohybrid systems with Au nanoparticles

In the presence of a small amount of a proteinous amino acid (arginine/tryptophan/histidine) or a nucleoside (adenosine/guanosine/cytidine), graphene oxide (GO) forms supramolecular stable hydrogels. These hydrogels have been characterized by field-emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) analysis, Raman spectroscopy, and rheology. The morphology of the hydrogel reveals the presence of nanofibers and nanosheets. This suggests the supramolecular aggregation of GO in the presence of an amino acid/nucleoside. Rheological studies of arginine containing a GO-based hydrogel show a very high G' value (6.058 × 10(4) Pa), indicating the rigid, solid-like behavior of this gel. One of these hydrogels (GO-tryptophan) has been successfully utilized for the in situ synthesis and stabilization of Au nanoparticles (Au NPs) within the hydrogel matrix without the presence of any other external reducing and stabilizing agents to make Au NPs containing the GO-based nanohybrid material. The Au NPs containing the hybrid hydrogel has been characterized by using UV/vis spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). In this study, gold salt (Au(3+)) has been bioreduced by the tryptophan within the hydrogel. This is a facile "green chemical" method of preparing the GO-based nanohybrid material within the hydrogel matrix. The significance of this method is the in situ reduction of gold salt within the gel phase, and this helps to decorate the nascently formed Au NPs almost homogeneously and uniformly on the surface of the GO nanosheets within the gel matrix.     

Reusable antifouling viscoelastic adhesive with an elastic skin

Although the viscoelasticity or tackiness of a pressure-sensitive adhesive gives it strength owing to energy dissipation during peeling, it also renders it nonreusable because of structural changes such as the formation of fibrils, cohesive failure, and fouling. However, an elastic layer has good structural integrity and cohesive strength but low adhesive energy. We demonstrate an effective composite adhesive in which a soft viscoelastic bulk layer is imbedded in a largely elastic thin skin layer. The composite layer is able to meet the conflicting demands of the high peel strength comparable to the viscoelastic core and the structural integrity, reusability, and antifouling properties of the elastic skin. Our model adhesive is made of poly(dimethylsiloxane), where its core and skin are created by varying the cross-linking percentage from 2 to 10%.