RBE of "Prometeus" Facility Protons for Irradiation of Tumor Cells in Vitro with One and Three Fields

The study was aimed to the biological effectiveness of the proton scanning beam of the first Russian medical facility. The clonogenic assay of B-16 tumor cells was used as a test system. Cell irradiation was carried out in a suspension condition in a water phantom. Single and three-field exposures were studied. The dose interval was 2-8 Gy. The energy range from 47.5 to 92.0 MeV was used for the Bragg peak formation. The relative biological effectiveness of protons comparing to gamma-rays was 1.2 for single-field and 1.5 for three-field irradiation. The results obtained agree with literature data related to the used cell culture (B-16) and linear energy transfer range (3÷8 keV/µm)

An Upper Limit for H-Particle Production and Subthreshold Double Strangeness Production in Annihilation of Antiprotons on Xe Nuclei at Low Energy

peer reviewe

Authentication of beef versus horse meat using 60 MHz H-1 NMR spectroscopy

This work reports a candidate screening protocol to distinguish beef from horse meat based upon comparison of triglyceride signatures obtained by 60 MHz H-1 NMR spectroscopy. Using a simple chloroform-based extraction, we obtained classic low-field triglyceride spectra from typically a 10 min acquisition time. Peak integration was sufficient to differentiate samples of fresh beef (76 extractions) and horse (62 extractions) using Naive Bayes classification. Principal component analysis gave a. two-dimensional "authentic" beef region (p = 0.001) against which further spectra could be compared. This model was challenged using a subset of 23 freeze thawed training samples. The outcomes indicated that storing samples by freezing does not adversely affect the analysis. Of a further collection of extractions from previously unseen samples, 90/91 beef spectra were classified as authentic, and 16/16 horse spectra as non-authentic. We conclude that 60 MHz 1H NMR represents a feasible high-throughput approach for screening raw meat. (C) 2014 The Authors. Published by Elsevier Ltd