Quality and safety problems of sports nutrition products

The purpose of this work was to study the quality and safety of some sports nutrition products. The objects of study were sports nutrition products: protein bars of ‘ProteinBar’ (Russia) and ‘Bombbar’ (Russia); capsule forms of dietary supplements ω–3, ω–6, ω–9 firms ‘Sportline’ (Russia), ‘Multipower’ (Germany) and ‘Maxler’ (USA). According to the research results, the normalized safety indicators of the fat component of the studied products for sports nutrition (acid number and peroxide) are within acceptable values. The standardized safety indicators of the fat component do not fully reflect the safety requirements for the fat component of sports nutrition products, since there are no standards for the most important indicators of fat safety – the content of secondary oxidation products – copolymers insoluble in petroleum ether and epoxides. The results obtained in the course of the work showed that in almost all of the studied samples are content of epoxides (7.5–47.6 g -1 ) and secondary oxidation products – 1% or more

Thermodynamic parameters of bonds in glassy materials from viscosity-temperature relationships

Doremus's model of viscosity assumes that viscous flow in amorphous materials is mediated by broken bonds (configurons). The resulting equation contains four coefficients, which are directly related to the entropies and enthalpies of formation and motion of the configurons. Thus by fitting this viscosity equation to experimental viscosity data these enthalpy and entropy terms can be obtained. The non-linear nature of the equation obtained means that the fitting process is non-trivial. A genetic algorithm based approach has been developed to fit the equation to experimental viscosity data for a number of glassy materials, including SiO2, GeO2, B2O3, anorthite, diopside, xNa2O–(1-x)SiO2, xPbO–(1-x)SiO2, soda-lime-silica glasses, salol, and α-phenyl-o-cresol. Excellent fits of the equation to the viscosity data were obtained over the entire temperature range. The fitting parameters were used to quantitatively determine the enthalpies and entropies of formation and motion of configurons in the analysed systems and the activation energies for flow at high and low temperatures as well as fragility ratios using the Doremus criterion for fragility. A direct anti-correlation between fragility ratio and configuron percolation threshold, which determines the glass transition temperature in the analysed materials, was found

HYPERACCUMULATION OF CADMIUM IN MAIZE PLANT (Zea Mays)

Maize plant responses, in terms of growth and metal uptake, to different concentrations of cadmium ions (4, 20 µM) were analyzed in a hydroponic culture, for 2 weeks. For a 4 µM cadmium-contaminated environment, the maize plant presents the highest bioaccumulation level after 192 h, with a recovery degree of 52%, meanwhile, at a 20 µM concentration, the highest bioaccumulation was registered after 366 h, with a corresponding recovery degree after 288 h (10.56%). The translocation factor presented higher values for 20 µM induced contamination than for 4 µM, which means that increasing metal concentration in the medium increased the concentration in the upper parts of the plant. Anatomical sections of a maize plant (in a 4 and 20 µM cadmium-contaminated environment) were observed to evidence the changes in plant morphological structure. The efficiency of phytoextraction is related to the metal concentration in the environment and to the plant's ability to grow on polluted soil sites, concomitantly with a high biomass yield. Keywords: heavy metal, phytoremediation, bioaccumulation, translocation factor INTRODUCTION Heavy metal contamination is a serious environmental problem that limits crop production and threatens human health through the food chain. Cadmium, one of the most toxic environmental pollutants for plants, may interfere with numerous biochemical and physiological processes -including photosynthesis, respiration, nitrogen and protein metabolism, and nutrient uptake. Phytoremediation is an in situ nondestructive technique, characterized by the utilization of hyperaccumulator plant species to remove the heavy metals from soil. The suitability of a certain plant for heavy metal remediation is determined by various plant properties, such as heavy metal tolerance, size, growth rate and rooting depth, heavy metal accumulation in aboveground plant parts and climatic adaptation and pest resistance. 1,2 The aim of this research was to evaluate the maize plant responses to cadmium stress conditions, every 48 h, for 2 weeks, and the efficiency in phytoremediation processes. EXPERIMENTAL Maize seeds (Zea mays) were sterilized in the commercial bleaching agent HOCl (1%) for 30 min and rinsed with distilled water under stirring for 10 min, the process being repeated 3 times. The seeds were placed over moist filter paper disks in Petri dishes and stored in the dark at 25 ºC, with a view to their germination. The , 5 µM Fe) with the pH adjusted 3 to 6.8. The plastic pots were covered with an aluminum foil to prevent the development of photosynthetic algae. After 5 days of germination, seedlings of maize with the same size were assembled in each hydroponic unit. The volume of nutrient solution (150 mL) was not modified throughout the experiments, to avoid the variation of metal concentrations. Every 48 h and at the end of the assay (2 weeks), the contents of cadmium in the roots, stem and leaves, as well as the growth parameters of maize plants, were determined. The plant roots were rinsed in abundant tap and distilled water ALINA STINGU et al. 288 before mineralization. Maize plants separated into roots, stems and leaves were oven-dried at 60 ºC, until constant mass was reached, and then the plant tissues were digested 4 using HNO 3 (65%) and H 2 O 2 (30%), on a hot plate at 120 ºC, for at least 5 h. The measurement of the metal content in the solution was accomplished through AAS (using a GBC Avanta 2003 Atomic Absorption Spectrophotometer). To evaluate the growth rate of the maize plant every 48 h, in a cadmium-contaminated environment, the following formula was used: growth rate, % = 100 x (growth parameters at the beginning of the experiment -growth parameters at a considered time)/growth parameters at a considered time. Spectrophotometric quantification of heavy metal concentration in maize plant tissues permitted the evaluation of cadmium bioaccumulation, translocation factor and recovery: Bioaccumulation coefficient = (cadmium concentration µg/g dry plant tissue)/(cadmium concentration µg/mL nutrient solution); 5 Translocation factor (TF) = ratio of metal concentration in shoots/ratio of metal concentration in roots; 6 Recovery, % = metal content in shoot or root/metal content in the medium. 7 At the end of the experiment, histological cross-sections were obtained for maize roots. The sections were cut manually, using microtome and elder pith as a support. The histological sections were washed in sodium hypochlorite, then in acetic acid (to eliminate the cellular content) and distilled water. The sections were coloured with iodine green (1 min), washed in 90% ethylic alcohol and distilled water, then coloured with ruthenium red (1 min) and again washed in distilled water. RESULTS AND DISCUSSION In the first hours, under 4 µM cadmium stress conditions, an increasing trend in plant growth and development was observed, the maximum growth rate being registered at 144 h. 192 h after the beginning of the experiment, the growth process seemed to stop, being resumed after 48 h. For a 20 µM cadmium-contaminated environment, the maximum growth rate was registered in the first 48 h. After 192 h, a decreasing trend in plant growth was observed. Maize plant growth rate decreased with increasing cadmium concentration in the growth medium Cadmium concentration (μg/g dry mass) and content (μg/plant) in maize plant presented different values, as depending on metal contamination level. The highest values for cadmium concentration and content (390.04 μg/plant), under 4 µM stress conditions (15430.99 μg/g), were registered at 192 h. Reported to the 20 µM cadmiumcontaminated environment, the highest metal content (395.82 μg/plant) and concentration (22443.54 μg/g) were recorded at 228 and 336 h. These results could be correlated with the plant growth rat

Topologically disordered systems at the glass transition

The thermodynamic approach to the viscosity and fragility of amorphous oxides was used to determine the topological characteristics of the disordered network-forming systems. Instead of the disordered system of atoms we considered the congruent disordered system of interconnecting bonds. The Gibbs free energy of network-breaking defects (configurons) was found based on available viscosity data. Amorphous silica and germania were used as reference disordered systems for which we found an excellent agreement of calculated and measured glass transition temperatures. We reveal that the Hausdorff dimension of the system of bonds changes from Euclidian three-dimensional below to fractal 2.55 ± 0.05-dimensional geometry above the glass transition temperature

Promastigote secretory gel from natural and unnatural sand fly vectors exacerbate Leishmania major and Leishmania tropica cutaneous leishmaniasis in mice.

Leishmania rely heavily on glycans to complete their digenetic life cycle in both mammalian and phlebotomine sand fly hosts. Leishmania promastigotes secrete a proteophosphoglycan-rich gel (Promastigote Secretory Gel, PSG) that is regurgitated during transmission and can exacerbate infection in the skin. Here we explored the role of PSG from natural Leishmania-sand fly vector combinations by obtaining PSG from Leishmania (L.) major-infected Phlebotomus (P.) papatasi and P. duboscqi and L. tropica-infected P. arabicus. We found that, in addition to the vector's saliva, the PSG from L. major and L. tropica potently exacerbated cutaneous infection in BALB/c mice, improved the probability of developing a patent cutaneous lesion, parasite growth and the evolution of the lesion. Of note, the presence of PSG in the inoculum more than halved the prepatent period of cutaneous L. tropica infection from an average of 32 weeks to 13 weeks. In addition, L. major and L. tropica PSG extracted from the permissive experimental vector, Lutzomyia (Lu.) longipalpis, also exacerbated infections in mice. These results reinforce and extend the hypothesis that PSG is an important and evolutionarily conserved component of Leishmania infection that can be used to facilitate experimental infection for drug and vaccine screening

Structural identification of oxidized acyl-phosphatidylcholines that induce platelet activation

Oxidation of low-density lipoprotein (LDL) generates proinflammatory and prothrombotic mediators that may play a crucial role in cardiovascular and inflammatory diseases. In order to study platelet-activating components of oxidized LDL 1-stearoyl-2-arachidonoyl-sn-glycero-3- phosphocholine, a representative of the major phospholipid species in LDL, the 1-acyl-phosphatidylcholines (PC), was oxidized by CuCl2 and H2O2. After separation by high-performance liquid chromatography, three compounds were detected which induced platelet shape change at low micromolar concentrations. Platelet activation by these compounds was distinct from the pathways stimulated by platelet-activating factor, lysophosphatidic acid, lyso-PC and thromboxane A(2), as evidenced by the use of specific receptor antagonists. Further analyses of the oxidized phospholipids by electrospray ionization mass spectrometry structurally identified them as 1-stearoyl-2-azelaoyl-sn-glycero-3-phosphocholine (m/z 694; SAzPC), 1-stearoyl-2-glutaroyl-snglycero-3- phosphocholine (m/z 638; SGPC), and 1-stearoyl-2-( 5-oxovaleroyl)-sn-glycero-3-phosphocholine (m/z 622; SOVPC). These observations demonstrate that novel 1-acyl-PC which had previously been found to stimulate interaction of monocytes with endothelial cells also induce platelet activation, a central step in acute thrombogenic and atherogenic processes. Copyright (C) 2005 S. Karger AG, Basel

Visualisation of Leishmania donovani Fluorescent Hybrids during Early Stage Development in the Sand Fly Vector

hybrids were produced by co-infecting sand flies with two strains carrying different drug resistance markers. However, the location and timing of hybridisation events in sand flies has not been described. strains carrying hygromycin or neomycin resistance genes and red or green fluorescent markers. Fed females were dissected at different times post bloodmeal (PBM) and examined by fluorescent microscopy or fluorescent activated cell sorting (FACS) followed by confocal microscopy. In mixed infections strains LEM3804 and Gebre-1 reached the cardia and stomodeal valves more rapidly than strains LEM4265 and LV9. Hybrids unequivocally expressing both red and green fluorescence were seen in single flies of both vectors tested, co-infected with LEM4265 and Gebre-1. The hybrids were present as short (procyclic) promastigotes 2 days PBM in the semi-digested blood in the endoperitrophic space. Recovery of a clearly co-expressing hybrid was also achieved by FACS. However, hybrids could not sustain growth in vitro. has profound epidemiological significance, because it facilitates the emergence and spread of new phenotypic traits

Removing exogenous information using pedigree data

Management of certain populations requires the preservation of its pure genetic background. When, for different reasons, undesired alleles are introduced, the original genetic conformation must be recovered. The present study tested, through computer simulations, the power of recovery (the ability for removing the foreign information) from genealogical data. Simulated scenarios comprised different numbers of exogenous individuals taking partofthe founder population anddifferent numbers of unmanaged generations before the removal program started. Strategies were based on variables arising from classical pedigree analyses such as founders? contribution and partial coancestry. The ef?ciency of the different strategies was measured as the proportion of native genetic information remaining in the population. Consequences on the inbreeding and coancestry levels of the population were also evaluated. Minimisation of the exogenous founders? contributions was the most powerful method, removing the largest amount of genetic information in just one generation.However, as a side effect, it led to the highest values of inbreeding. Scenarios with a large amount of initial exogenous alleles (i.e. high percentage of non native founders), or many generations of mixing became very dif?cult to recover, pointing out the importance of being careful about introgression events in populatio