Paramagnetic contribution of serum iron to the spin-lattice relaxation rate (1/T 1) determined by MRI

T ₁ maps of phantoms containing the samples of pure serum or Mn(II)-doped serum at pH=2 were imaged by 1.5 T and 1 T MR Imagers. TheT ₁ measurements made for the determination of the paramagnetic increase were carried out before and after adding ascorbic acid. The difference of the 1/T ₁ in samples with and without ascorbic acid was evaluated as the paramagnetic contribution (PMC) of serum iron. As iron content of serum varied from iron deficient to iron overload, the PMC values increased from 0.93 to 0.565 s^?1 at 1.5 T and from 0.103 to 0.609 s^?1 at 1 T. For confirmative purposes, serum iron of each sample was determined from the paramagnetic contribution and also by an autoanalyzer. The contents of serum iron determined from PMC were in good agreement with those by the autoanalyzer and also with the literature. The data suggest that the paramagnetic contribution of serum iron can be measured by MRI.     

Novel antifouling oligo(ethylene glycol) methacrylate particles via surfactant-free emulsion polymerization

The use of particle formulations with antifouling surface properties attracts increasing interest in several biotechnological applications. Majority of these studies utilize a poly(ethylene glycol) coating to render the corresponding surface nonrecognizable to biological macromolecules. Herein, we report a simple way to prepare novel antifouling colloids composed of oligo(ethylene glycol) backbones via surfactant-free emulsion polymerization. Monodisperse cross-linked poly(ethylene glycol) ethyl ether methacrylate particles were characterized by dynamic light scattering and transmission electron microscopy. The effects of monomer, cross-linker and initiator on particle characteristics were investigated. More importantly, a prominent blockage of bovine serum albumin adsorption was obtained for the poly(ethylene glycol)-based sub-micron (~200 nm) particles when compared with similar-sized poly(methyl methacrylate) counterparts.     

Optical Soliton Perturbation with Generalized Quadratic–Cubic Nonlinearity by Semi-Inverse Variation

Optics and Spectroscopy - The current work recovers a perturbed bright 1-soliton solution to the governing model that maintains generalized quadratic–cubic nonlinearity. The perturbation...     

Monte Carlo Calculations of XRF Intensities in Annular Arrangements of Radioactive Source,Sample, Cylindrical Collimator and Detector

ABSTRACT

A Monte Carlo (MC) computer program for the calculation of the distribution of characteristic X-ray intensities as a function of the counting geometry is described. The program evaluates the contribution to the intensities of a fluorescent line from each point of the source, sample and detector. The main considerations of the calculation are based on the critical nature of the internal geometry of the main analyzer components within an energy dispersive X-ray fluorescence (EDXRF) spectrometer. The K XRF intensities for the inner and outer radius of the annular-sample and collimator radius were measured. An optimum geometry can be obtained by varying the collimator radius and the detector-sample distance. The results of the calculations show that the intensity distribution of the radioisotope excited fluorescent radiation through annular sample area is strongly dependent on the collimator radius, with a maximum intensity effect with a smaller sample area and with decreasing collimator radius. An investigation of the XRF intensities in the annular sample surface as a function of collimator radius is discussed.     

The Harmonic Oscillator Influenced by Gravitational Wave in Noncommutative Quantum Phase Space

Dynamical property of harmonic oscillator affected by linearized gravitational wave (LGW) is studied in a particular case of both position and momentum operators which are noncommutative to each other. By using the generalized Bopp’s shift, we, at first, derived the Hamiltonian in the noncommutative phase space (NPS) and, then, calculated the time evolution of coordinate and momentum operators in the Heisenberg representation. Tiny vibration of flat Minkowski space and effect of NPS let the Hamiltonian of harmonic oscillator, moving in the plain, get new extra terms from it’s original and noncommutative space partner. At the end, for simplicity, we take the general form of the LGW into gravitational plain wave, obtain the explicit expression of coordinate and momentum operators.     

Accurate and simple determination of oxcarbazepine in human plasma and urine samples using switchable-hydrophilicity solvent in GC–MS

This work presents a sensitive and rapid analytical method for the determination of oxcarbazepine in human plasma and urine samples. A vortex-assisted switchable hydrophilicity solvent-based liquid phase microextraction (VA–SHS–LPME) was used to preconcentrate oxcarbazepine from the samples before the determination by gas chromatography mass spectrometry. The switchable hydrophilicity solvent was synthesized by protonating N,N-dimethylbenzylamine with carbon dioxide to make it totally miscible with an equivalent volume of water. Parameters of the VA–SHS–LPME method including volume of switchable hydrophilicity solvent, concentration/volume of sodium hydroxide and vortex period were systematically optimized. Under the optimum conditions, good linearity ranging from 27.03 to 353.47 μg/kg was obtained for the analyte. Limit of detection and quantitation values were found to be 6.2 and 21 μg/kg (mass base), respectively. The relative standard deviation was calculated as 6.9% for six replicate measurements of the lowest concentration of the calibration plot. Satisfactory recovery results were calculated in the range of 97–100% for human plasma and urine samples spiked at five different concentrations.     

Synthesis and Characterization of α-Bromo Chalcone Derivatives

α-Bromo chalcones containing 2-thiene ring were prepared in good yields by the condensation of 1-(thien-3-yl)ethanone with aromatic aldehydes, followed by bromination with bromine and selective dehydrobromination with triethyl amine at room temperature.     

Determination of K, Ca, Fe and Ni in Leptinotarsa decemlineata (Say) by EDXRF spectroscopy

The metal content of Colorado potato beetles elytra in Turkey was determined using the energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of standard addition is applied for the elemental analysis of Colorado potato beetles elytra. An annular ²⁴¹Am radioactive source and an annular ⁵⁵Fe radioactive source were used for excitation of characteristic K X-rays. An Si(Li) detector which has a full-width at half-maximum for photons was used for intensity measurements. The procedure of sample preparation and the results of analysis were presented.