Vibrational frequencies and structure of 2-thiouracil by Hartree-Fock,post-Hartree-Fock and density functional methods

Vibrational study of the biomolecule 2-thiouracil was carried out. Ab initio and density functional calculations were performed to assign the experimental spectra. A comparison with the uracil molecule was made, and specific scale factors were deduced and employed in the predicted frequencies of 2-thiouracil. Several scaling procedures were used. The geometry structure of the molecule was determined. The effect of sulfur substitution at C2 position in the uracil molecule, on the N1-H and N3-H frequencies and intensities reflects changes in proton donor abilities of these groups. Calculations with the 6-31 G** basis set with HF and DFT methods appear in general to be useful for interpretation of the general features of the IR and Raman spectra of the molecule. Using specific scale factors a very small error was obtained. The use of these specific scale factors resolve and correct some of the controversial assignments in the literature.     

RP-LC Resolution of (R,S)-Atenolol via Diastereomerization with Marfey’s Reagent and Its Structural Variants Under Conventional and Microwave Heating

(R,S)-Atenolol was derivatized with Marfey’s reagent, (MR; 1-fluoro-2,4-dinitrophenyl-5-l-alanine amide or FDNP-l-Ala-NH₂) and its four structural variants (FDNP-l-Phe-NH₂, FDNP-l-Val-NH₂, FDNP-l-Leu-NH₂ and FDNP-l-Pro-NH₂). MR reacts quantitatively with 1° and 2° amino groups and atenolol has a secondary amino group. The derivatization reactions were carried out under conventional and microwave heating and compared. The resulting diastereomers were separated on RP-TLC and on a C18 column with detection at 340 nm. (R)-Isomer eluted before (S). The conditions of derivatization and chromatographic separation were optimized. The method was validated for linearity, repeatability, limits of detection and limit of quantification.     

Understanding the Miscibility and Morphology of Poly(methyl methacrylate) and Styrenic Copolymer Blends of Tunable Domain Sizes

In the present study, we have investigated the miscibility, morphology and mechanical behavior of poly(methyl methacrylate) (PMMA) blends with a series of poly(styrene-co-maleic anhydride) (SMA) copolymers containing varying amounts of maleic anhydride (MA) content (from 8 to 26%). The experimental findings have been substantiated by the modeling studies to gain fundamental understanding of the observed phenomena with respect to the miscibility of the PMMA and SMA blends of a given MA content. The morphological differences, molecular weights, domain sizes and mechanical behavior of the blends at a given ratio of PMMA and copolymers have been investigated and a correlation has been made between the morphological understanding to the molecular weights and mechanical properties. The results indicate that the PMMA/SMA blends are miscible only at a certain MA content providing transparent PMMA/SMA blends without affecting any of the enabling properties of PMMA that are of commercial interest through a facile melt mixing process. The surface hardness and % recovery (nano-indentation) of these blends were evaluated as well to gain fundamental understanding of the surface characteristics and mechanicals of the blends.     

Interaction parameters for multi-component aromatic extraction with sulfolane

Aromatic extraction is an important operation in petrochemical processing. Design of an aromatic extractor requires the knowledge of multi-component liquid–liquid equilibrium (LLE) data. Such experimental LLE data are usually not available and therefore can be predicted using various activity coefficient models. These models require proper binary interaction parameters, which are not yet available for all aromatic extraction systems. Furthermore, the parameters available for most of the ternary systems are specific to that system only and cannot be used for other ternary or multi-component systems. An attempt has been made to obtain these parameters that are globally applicable. For this purpose, the parameter estimation procedure has been modified to estimate the parameters simultaneously for different systems involving common pairs. UINQUAC and UNIFAC models have been used for parameter estimation. The regressed parameters are shown to be applicable for the ternary as well as for the multi-component systems. It is observed that UNIQUAC parameters provide a better fit for ternary LLE data, whereas, as one moves towards the higher component systems (quaternary and quinary) the UNIFAC parameters, which are a measure of the group contributions, predict the LLE better. Effect of temperature on UNIQUAC binary interaction parameters has been studied and a linear dependence has been observed.     

Direct TLC Resolution of the Enantiomers of Three β-Blockers by Ligand Exchange with Cu(II)–l-Amino Acid Complex, Using Four Different Approaches

TLC experiments have been performed to resolve the enantiomers of three β-blockers by complexation chiral TLC with Cu(II) cation and five l amino acids. Loading was carried out by using the Cu(II)–l amino acid complex as chiral mobile phase additive with untreated silica gel plates; by mixing the Cu complex with silica gel before preparing the TLC plates; by ascending development of untreated plates with solutions of the Cu complex; and by using a solution of Cu(II) acetate as mobile phase additive for plates prepared by mixing the l amino acid with silica gel. Spots were located by use of iodine vapour.     

Selective Cluster-Based Temperature Monitoring System for Homogeneous Wireless Sensor Networks

Over the past few decades, there has been a revolution in ICT, and this has led to the evolution of wireless sensor networks(WSN), in particular, wireless body area networks. Such networks comprise a specialized collection of sensor nodes(SNs) that may be deployed randomly in a body area network to collect data from the human body. In a health monitoring system, it may be essential to maintain constant environmental conditions within a specific area in the hospital. In this paper, we propose a temperature-monitoring system and describe a case study of a health-monitoring system for patents critically ill with the same disease and in the same environment. We propose Enhanced LEACH Selective Cluster(E-LEACH-SC) routing protocol for monitoring the temperature of an area in a hospital. We modified existing Selective Cluster LEACH protocol by using a fixed-distance-based threshold to divide the coverage region in two subregions. Direct data transmission and selective cluster-based data transmission approaches were used to provide short-range and long-distance coverage for the collection of data from the body of ill patients. Extensive simulations were run by varying the ratio of node densities of the two subregions in the health-monitoring system. Last Node Alive(LNA), which is a measure of network lifespan, was the parameter for evaluating the performance of the proposed scheme. The simulation results show that the proposed scheme significantly increases network lifespan compared with traditional LEACH and LEACH-SC protocols, which by themselves improve the overall performance of the health-monitoring system.     

Reversed‐phase liquid chromatographic determination of enantiomers of atenolol in rat plasma using derivatization with Marfey's reagent

An HPLC method was established for enantioseparation of (R,S)‐atenolol (ATE) and determination of enantiomers in rat plasma. Marfey's reagent (1‐fluoro‐2,4‐dinitrophenyl‐5‐L‐alanine amide, FDNP‐L‐Ala‐NH₂, MR) was used as chiral derivatizing reagent with detection of diastereomers at 340 nm. It was shown that the R‐isomer eluted before the S‐isomer. The method was validated for linearity, repeatability, limits of detection and limit of quantification (LOQ). Recovery of ATE at LOQ was 92.8% for (R)‐ATE and 92.6% for (S)‐ATE. Copyright © 2009 John Wiley & Sons, Ltd.     

Facile synthesis of non-ionic dimeric molecular resonance imaging contrast agent: its relaxation and luminescence studies

A bis-polyazamacrocycle, 10'-bis(acetamido)ethane-bis[1,4,7-tri(carboxymethane)-1,4,7,10-tetraazacyclododecane] (DO3A-AME-DO3A) was synthesized for application in magnetic resonance imaging. The efficacy of DO3A-AME-DO3A as non ionic magnetic contrast agent was tested by performing relaxometric studies on its gadolinium complex. The longitudinal relaxivity, r(1) and transverse relaxivity, r(2) values were found to be 5.84 mM(-1)s(-1) and 6.82 mM(-1)s(-1), per Gd(III) at pH 7.0, 37 °C. The luminescence properties of europium complex of DO3A-AME-DO3A were investigated in aqueous medium. The lifetime of Eu(2)-DO3A-AME-DO3A in water was found to be 0.786 ms. Emission and luminescence lifetime measurements on the europium complex of DO3A-AME-DO3A gives a hydration number of q = 1.9. The reaction enthalpy and entropy were found to be, ΔH(0) = -(6.2 ± 2) kJ mol(-1), ΔS(0) = - (1.8 ± 0.4) kJ mol(-1)K(-1), and K(Eu)(298) = (1.8 ± 0.1).     

Tactile internet and its applications in 5G era: A comprehensive review

Over the last few years, communication latency has been a major hurdle for most of the applications deployed in different network domains. During this era, a number of communication protocols and standards were developed and used by the community. However, still, the problem of latency persists keeping in view of the quality of service (QoS) and quality of experience (QoE) for different applications. To mitigate the aforementioned issues, in this paper, we present an in‐depth survey of state‐of‐the art proposals having tactile internet as a backbone for delay mitigation using 5G networks for future ultra‐reliable low‐latency applications such as Healthcare 4.0, Industry 4.0, virtual reality and augmented reality, and smart education. From the existing proposals, it has been observed that tactile internet can provide interactions between virtual objects to give a feel of real environment with maximum latency of 1 millisecond. Also, this paper highlights the key differences between the tactile internet and Internet of Things in context with 5G revolution. Then open issues and challenges of tactile internet for smart applications are analyzed. Finally, a comparison of existing proposals with respect to various parameters is presented, which allows the end users to select one of the proposals in comparison with its merits over the others.     

An Unprecedented Blueshifted Naphthalimide AIEEgen for Ultrasensitive Detection of 4‐Nitroaniline in Water via “Receptor‐Free” IFE Mechanism

The development of a new naphthalene appended naphthalimide derivative ( NMI ) with aggregation‐induced enhanced emission (AIEE) property for the sensitive detection of 4‐nitroaniline (4‐NA) in aqueous media is presented here. The newly designed naphthalimide AIEEgen has an exceptional blue‐shifted condensed state emission that is devoid of any receptor site, accomplished ultrasensitive detection of 4‐NA, which is one of the broad‐spectrum pesticides that belong to the class III toxic chemical, at parts per billion level (LOD/36 ppb, K_sv=4.1×10⁴ m ^?1) in water with excellent selectivity even in the presence of potentially competing aliphatic and aromatic amines. The reported probe is the first of its kind, demonstrating major advantages of receptor‐free inner filter effect (IFE) mechanism for the sensitive detection of 4‐NA using an AIEEgenic probe. Excellent sensitivity for 4‐NA is also achieved on paper‐based test‐strip for low‐cost on‐site detection.