Development of high sensitive real-time PCR to detect mustard and other allergens of the family Brassicaceae in food samples

Mustard is a commonly used condiment including in production of other food products. As mustard is an allergen, it is necessary to control its presence. The development of PCR test-systems for its detection is complicated by the fact that this condiment can be made from seeds of various plant species (Brassica juncea, Brassica nigra, Sinapis alba) of the family Brassicaceae that are not closely related. This family includes other plant species such as white cabbage (Brassica oleracea) and rapeseed (Brassica napus), which can cause the allergic reaction, although seldom. In this connection, many authors use primers specific to many species of this family, including to allergens, to detect mustard. In this work, we used the similar strategy. To increase sensitivity, primers for the mitochondrial COX gene were selected. To increase PCR stability in analysis of deeply processed products, primers were selected for a region with a length of 61 base pair. In the work, the specificity and sensitivity of the developed PCR method was confirmed. Analyses of different products, including those that underwent deep technological processing, were carried out with these primers. Also, primers were selected to detect white mustard (S. alba). When analyzing products on the presence of white mustard, charac‑ teristic regional preferences were demonstrated: this species is used in manufacturing products mainly in the UK and USA

Test of an LED Monitoring System for the PHOS Spectrometer

Preprint submitted to Elsevier Print on 26th January 2000A prototype monitoring system for the Photon Spectrometer (PHOS) of the ALICE experiment at LHC is described in detail. The prototype consists of Control and Master modules. The first one is 8x8 matrix of Light Emitting Diodes coupled with stable generators of current pulses. The system provides an individual control for each of the 64 channels of PHOS prototype based on lead-tungstate crystals. A long term stability of order of 10-3 has been achieved in integral beam tests of the monitoring system and PHOS prototypes

Extended Emission from Short Gamma-Ray Bursts Detected with SPI-ACS/INTEGRAL

The short duration (T90 < 2 s) gamma-ray bursts (GRBs) detected in the SPI-ACS experiment onboard the INTEGRAL observatory are investigated. Averaged light curves have been constructed for various groups of events, including short GRBs and unidentified short events. Extended emission has been found in the averaged light curves of both short GRBs and unidentified short events. It is shown that the fraction of the short GRBs in the total number of SPI-ACS GRBs can range from 30 to 45%, which is considerably larger than has been thought previously.Comment: 27 pages, 10 figure

Определение подлинности куркумы

The paper examines the problem of the composition instability in the ready ground spice, turmeric. Analysis of the prevalent methods for turmeric adulteration and substances used for these purposes is given. The visual assessment of color tints of the turmeric root, spices containing it and chemical dyes based on chromium salts is presented. The studies on determination of the lead and chromium content were carried out to study the content of these metals and test the hypothesis of using lead chromate as a dye in adulteration of turmeric. Using the method of electrothermal atomic absorption spectroscopy, it was found that the lead content in the analyzed turmeric samples varied from 1.72 ± 0.58 to 5.03 ± 1.80 mg/kg, while the chromium content was in a range of 5.56 ± 0.85 to 16.15 ± 2.32 mg/kg. As a result of species specific PCR, wheat DNA was revealed in all purchased samples of ground turmeric. The levels of the main raw material replacement were established, which were 0.14% to 14.95% with the correlation coefficient close to 100%; efficiency of the reaction was 1.95, which was 97.5% when expressed as percentage. These levels of an undeclared allergen in the product composition can cause a serious allergic reaction. The authors tested the hypothesis of introduction of sodium and potassium salts for correction of the color spectrum in the ready spice and its correspondence to the natural color within the color spectrum of turmeric. As a result of the complex study of the spice composition, quite high values of chromium were found, presumably not only from the lead chromate compound but also from chromic acid salts, as the high level of potassium that significantly exceeded the native content of this element was found.В работе рассмотрена проблематика нестабильности состава готовой молотой специи — куркума. Дан анализ наиболее распространенных способов фальсификации куркумы и веществ, применяемых для этих целей. Дана визуальная оценка цветовых оттенков корня куркумы, специй ее содержащих и химических красителей на основе солей хрома. Проведены исследования по содержанию свинца и хрома, с целью изучения содержания этих металлов и проверки гипотезы использования хромата свинца в качестве красителя при фальсификации куркумы. Методом электротермической атомно-абсорбционной спектрометрии установлено, что содержание свинца в исследованных образцах куркумы изменялось в пределах от 1,72 ± 0,58 до 5,03 ± 1,80 мг/кг, а содержание хрома варьировалось в диапазоне от 5,56 ± 0,85 до 16,15 ± 2,32 мг/кг. В результате проведения видоспецифической ПЦР была выявлена ДНК пшеницы во всех закупленных образцах молотой куркумы. Установлены уровни подмены основного сырья, которые составили от 0,14% до 14,95% с коэффициентом корреляции близким к 100%, эффективность реакции составила 1,95 что в процентном отношении составляет 97,5%. Такие уровни незаявленного в составе продукта аллергена могут вызывать серьезную аллергическую реакцию. Проверена гипотеза внесения солей натрия и калия, для коррекции цветовой гаммы готовой специи и соответствия ее натуральному цвету цветовой гамме куркумы. В результате комплексного изучения состава специи, обнаружены достаточно высокие значения хрома, предположительно не только из соединения хромата свинца, но и солей хромовой кислоты, т. к. было обнаружено высокое значение металла калия, значительно превышающее нативное содержание данного элемента

Capabilities of the GAMMA-400 gamma-ray telescope to detect gamma-ray bursts from lateral directions

The currently developing space-based gamma-ray telescope GAMMA-400 will measure the gamma-ray and electrons + positrons fluxes using the main top-down aperture in the energy range from ~20 MeV to several TeV in the highly elliptic orbit (without shadowing the telescope by the Earth and outside the radiation belts) continuously for a long time. The instrument will provide fundamentally new data on discrete gamma-ray sources, gamma-ray bursts (GRBs), sources and propagation of Galactic cosmic rays and signatures of dark matter due to its unique angular and energy resolutions in the wide energy range. The gamma-ray telescope consists of the anticoincidence system (AC), the converter-tracker (C), the time-of-flight system (S1 and S2), the position-sensitive and electromagnetic calorimeters (CC1 and CC2), the top and bottom scintillation detectors of the calorimeter (S3 and S4) and lateral detectors of the calorimeter (LD). In this paper, the capabilities of the GAMMA-400 gamma-ray telescope to measure fluxes of GRBs from lateral directions of CC2 are analyzed using Monte-Carlo simulations. The analysis is based on second-level trigger construction using signals from S3, CC2, S4 and LD detectors. For checking the numerical algorithm the data from space-based GBM and LAT instruments of the Fermi experiment are used, namely, three long bursts: GRB 080916C, GRB 090902B, GRB 090926A and one short burst GRB 090510A. The obtained results allow us to conclude that from lateral directions the GAMMA-400 space-based gamma-ray telescope will reliably measure the spectra of bright GRBs in the energy range from ~10 to ~100 MeV with the effective area of about 0.13 m2 (for each of the four sides of CC2) and total field of view of about 6 sr.Comment: 19 pages, 18 figures, the paper will be submitted to Advances in Space Researc