S pin a symmetrie s in ela stic electroweak ν($$ \bar v $$) p( s) scattering with allowance for the neutral weak magnetic,ana pole,and electric di pole moment s of the proton

Analytic expressions for cross sections and spin asymmetries characterizing processes of elastic weak, electromagnetic, and electroweak scattering of a neutrino (antineutrino) having electromagnetic moments on a polarized or an unpolarized proton target were obtained with allowance for the C-, P-, and T/CP-violating anapole and electric dipole moments and the neutral weak, electric, magnetic, and axial form factors of the proton, and these expressions were analyzed. The behavior of spin asymmetries was studied versus the energy and form-factor parameters.     

Electrically weak asymmetry in the elastic scattering of electrons by nuclei with multipole moments

The differential elastic-scattering cross section of longitudinally polarized electrons by nuclei of arbitrary spin and isospin is calculated in the Born approximation, taking into account the interference of electromagnetic interaction and the interaction of weak neutral currents. For a nucleus of spin J 3/2, explicit expressions are obtained for the interference terms in terms of the electromagnetic multipole form factors F_C, f_Q, f_M1 and f_M3. Using the example of the³He,¹¹B,¹⁹F and⁴⁰Ca nuclei, the behavior of electrically weak asymmetry of the cross section is investigated in detail in the framework of three gauge models. It is shown that the asymmetry of a_Rl is 10^–5 for E - 100 MeV, and is sensitive to the nuclear structure: By taking into account the contributions not only of the charge and magnetic-dipole scattering but also of the quadrupole and octupole scattering, one can obtain additional information on the structure of weak electron-nucleus interaction.This paper was presented at a conference on Investigations of Spin Phenomena in High-Energy Physics held at Protvino, November 23–26, 1982.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 79–84, April, 1984.     

An NMR study of the structure and molecular characteristics of polyether block copolymers based on propylene oxide and ethylene oxide

The structure of propylene oxide-ethylene oxide block copolymers prepared with the use of glycerol as an initiator and potassium monoglycerate as a catalyst was studied by NMR spectroscopy. The relative amounts of oxypropylene and oxyethylene monomer units, the functionality-type distribution, the number-average molecular mass, and the ratio between primary and secondary terminal hydroxyl groups were determined. The applicability of ¹H and ¹³C NMR techniques to characterization of these copolymers is discussed. The obtained NMR data are compared with results obtained by other techniques.     

Bovine serum albumin as a universal suppressor of non-specific peptide binding in vials prior to nano-chromatography coupled mass-spectrometry analysis

Non-specific binding (NSB) is a well-known problem for any application that deals with ultralow analyte quantities. The modern nano-flow chromatography coupled tandem mass-spectrometry (nanoLC-MS/MS) works with the lowest conceivable analyte concentrations. However, while the NSB problem is widely accepted and investigated for metabolomics and single-peptide medicine-related assays, its impact is not studied for complex peptide mixtures in proteomic applications. In this work peptide NSB to a common plastic autosampler vial was studied for a model mixture of 46 synthetic peptides. A significant NSB level was demonstrated for total peptide concentrations of up to 1 mg mL⁻¹. Different agents were tried for NSB suppression and compatibility with nanoLC-MS/MS analysis: a chaotropic agent, an amino acid mixture, a peptide mixture and a protein solution. The first two were inefficacious. The peptide matrix blocked NSB, however, it also led to analyte ionization suppression in nanoLC-MS/MS. The protein solution (0.1% BSA) efficiently eliminated NSB, while a trap-elute nanoHPLC configuration together with a small-pore reverse-phased sorbent effectively and quantitatively extracted the model peptides and depleted protein material from the sample. Higher protein concentration partially impeded peptide extraction. Thus, the 0.1% BSA solution might be regarded as an effective non-interfering blockader of NSB for sample resuspension and storage in an autosampler prior to LC-MS/MS analysis.     

Reaction of diethyl 3-methyl-1,2-butadienylphosphonate with 1,10-diaza-18-crown-6

Reaction of two-fold excess of diethyl 3-methyl-1,2-butadienylphosphonate with 1,10-diaza-18-crown-6 leads to the formation of an adduct whose molecule includes two 1-phosphoryl-3-methyl-2-butene fragments bound together by a crown bridge with the anti location of organophosphorus groups relative to the macrocycle plane. The 1,2-multiple bond of the phosphonate is involved in the reaction. Extraction properties of the diphosphorylated crown ether toward alkali metal picrates were studied.     

Molecular-weight characteristics and deemulsifying activity of oligourethanes based on alkylene oxide block copolymers and propylene oxide homopolymers prepared in the presence of a double metal cyanide catalyst

Russian Journal of Applied Chemistry - The molecular-weight characteristics of Laprol 6003-2B-18, of oligourethanes based on it, and of a new series of propylene oxide homopolymers prepared using a...