NMR Studies of the Mn²⁺ Interactions with Amyloid Peptide Aβ13-23 in Water Environment

© 2016, Springer Science+Business Media New York.In this paper, binding of Mn2+ ions to the fragment of beta-amyloid peptide (Aβ13-23) was studied. Manganese complexation induces important structural changes within the C-terminal segment of the peptide. Investigation of peptide–metal ion binding was made by MnCl2 salt titration and recording 2D 1H–1H NMR TOCSY spectra (TOtal Correlation SpectroscopY). Multidimensional NMR techniques were performed to understand the details of the conformational behavior of the peptide and to reveal the metal-binding sites. According to changes in NMR spectra, the manganese-binding center of the Aβ13-23 peptide is associated with the aspartate residue

Analysis of Bovine Serum Albumine, Caseine and tryptone proteins hydrolysis by 1H NMR spectroscopy

An adequate estimation of a proteinaceous substrate decomposition is one of the problems, frequently appearing during the protein hydrolysate technology. A combination of high-resolution 1H NMR spectroscopy data with other technics could be a good solution of this problem. In present paper we applied high-resolution 1H NMR spectroscopy method to characterize the degree of protein hydrolysis of the Bovine Serum Albumin, Caseine and Tryptone proteins and propose to use it in a combination with other methods to describe quality of the proteinaceous substrates. Due to the fact that the methods of evaluation of the protein hydrolysis degree are not universal so the combination of methods should be used for precise the description of proteinaceous substrate degradation. Based on the results from one dimensional 1H NMR spectra the hydrolysis of the protein molecules was analyzed by changes in the chemical shifts, multiplicities and line widths in 1H NMR spectra. It was shown that 1H NMR spectroscopy is an effective instrument for analyzing the protein hydrolysis reaction in solution

Particle flows in a dc discharge in laboratory and microgravity conditions

We describe a series of experiments on dust particles flows in a positive column of a horizontal dc discharge operating in laboratory and microgravity conditions. The main observation is that the particle flow velocities in laboratory experiments are systematically higher than in microgravity experiments, for otherwise identical discharge conditions. The paper provides an explanation for this interesting and unexpected observation. The explanation is based on a physical model, which properly takes into account main plasma-particle interaction mechanisms relevant to the described experimental study. Comparison of experimentally measured particle velocities and those calculated using the proposed model demonstrates reasonable agreement, both in laboratory and microgravity conditions, in the entire range of discharge parameters investigated.Comment: 9 pages, 7 figure

Studying radiation hardness of a cadmium tungstate crystal based radiation detector

The given article considers radiation hardness of an X-ray detector used in production of non-destructive testing instruments and inspection systems. In the course of research, experiments were carried out to estimate radiation hardness of a detector based on cadmium tungstate crystal and its structural components individually. The article describes a layout of an experimental facility that was used for measurements of radiation hardness. The radiation dose dependence of the photodiode current is presented, when it is excited by a light flux of a scintillator or by an external light source. Experiments were carried out to estimate radiation hardness of two types of optical glue used in detector production; they are based on silicon rubber and epoxy. With the help of a spectrophotometer and cobalt gun, each of the glue samples was measured for a relative light transmission factor with different wavelengths, depending on the radiation dose. The obtained data are presented in a comprehensive analysis of the results. It was determined, which of the glue samples is most suitable for production of detectors working under exposure to strong radiation

The PHENIX Experiment at RHIC

The physics emphases of the PHENIX collaboration and the design and current status of the PHENIX detector are discussed. The plan of the collaboration for making the most effective use of the available luminosity in the first years of RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program available at http://www.rhic.bnl.gov/phenix

Polarization squeezing and continuous-variable polarization entanglement

The Stokes-parameter operators and the associated Poincare sphere, which describe the quantum-optical polarization properties of light, are defined and their basic properties are reviewed. The general features of the Stokes operators are illustrated by evaluation of their means and variances for a range of simple polarization states. Some of the examples show polarization squeezing, in which the variances of one or more Stokes parameters are smaller than the coherent-state value. The main object of the paper is the application of these concepts to bright squeezed light. It is shown that a light beam formed by interference of two orthogonally-polarized quadrature-squeezed beams exhibits squeezing in some of the Stokes parameters. Passage of such a primary polarization-squeezed beam through suitable optical components generates a pair of polarization-entangled light beams with the nature of a two-mode squeezed state. The use of pairs of primary polarization-squeezed light beams leads to substantially increased entanglement and to the generation of EPR-entangled light beams. The important advantage of these nonclassical polarization states for quantum communication is the possibility of experimentally determining all of the relevant conjugate variables of both squeezed and entangled fields using only linear optical elements followed by direct detection.Comment: 27 pages, including 10 figure

P2Y receptors and pain transmission

It is widely accepted that the most important ATP receptors involved in pain transmission belong to the P2X3 and P2X2/3 subtypes, selectively expressed in small diameter dorsal root ganglion (DRG) neurons. However, several types of the metabotropic ATP (P2Y) receptors have also been found in primary afferent neurons; P2Y1 and P2Y2 receptors are typically expressed in small, nociceptive cells. Here we review the results available on the involvement of P2Y receptors in the modulation of pain transmission

Nonviral Approaches for Neuronal Delivery of Nucleic Acids

The delivery of therapeutic nucleic acids to neurons has the potential to treat neurological disease and spinal cord injury. While select viral vectors have shown promise as gene carriers to neurons, their potential as therapeutic agents is limited by their toxicity and immunogenicity, their broad tropism, and the cost of large-scale formulation. Nonviral vectors are an attractive alternative in that they offer improved safety profiles compared to viruses, are less expensive to produce, and can be targeted to specific neuronal subpopulations. However, most nonviral vectors suffer from significantly lower transfection efficiencies than neurotropic viruses, severely limiting their utility in neuron-targeted delivery applications. To realize the potential of nonviral delivery technology in neurons, vectors must be designed to overcome a series of extra- and intracellular barriers. In this article, we describe the challenges preventing successful nonviral delivery of nucleic acids to neurons and review strategies aimed at overcoming these challenges

Analysis of Bovine Serum Albumine, Caseine and tryptone proteins hydrolysis by 1H NMR spectroscopy

An adequate estimation of a proteinaceous substrate decomposition is one of the problems, frequently appearing during the protein hydrolysate technology. A combination of high-resolution 1H NMR spectroscopy data with other technics could be a good solution of this problem. In present paper we applied high-resolution 1H NMR spectroscopy method to characterize the degree of protein hydrolysis of the Bovine Serum Albumin, Caseine and Tryptone proteins and propose to use it in a combination with other methods to describe quality of the proteinaceous substrates. Due to the fact that the methods of evaluation of the protein hydrolysis degree are not universal so the combination of methods should be used for precise the description of proteinaceous substrate degradation. Based on the results from one dimensional 1H NMR spectra the hydrolysis of the protein molecules was analyzed by changes in the chemical shifts, multiplicities and line widths in 1H NMR spectra. It was shown that 1H NMR spectroscopy is an effective instrument for analyzing the protein hydrolysis reaction in solution