Flaxseed Cyclolinopeptides: Analysis and Storage Stability

Fourteen cyclolinopeptides (CLPs) from flaxseed oil and meal were separated, identified and quantified by HPLC coupled to an Orbitrap MS. The oxidative stability of the cyclolinopeptides was assessed during storage of flaxseed oil and meal. A significant decrease in the amounts of the methionine containing CLPs, namely CLP-B, CLP-J and CLP-M, and a concurrent increase in the amounts of methionine sulfoxide containing CLPs, such as CLP-C, CLP-E and CLP-G were observed. The cyclolinopeptides with two methionine units, CLP-L and CLP-M, exhibited the greatest decrease, followed by CLP-J, the major flaxseed oil bitter taste precursor, and CLP-B, a biologically active cyclolinopeptide. At the end of the storage period, the amount of the bitter CLP-E increased fourfold in the oil while the immunosuppressive cyclolinopeptides A remained unchanged. No significant changes in the amount of each of the CLPs were observed in the stored flaxseed meals. A fast and reliable procedure has been developed for quantitative analysis of cyclolinopeptides. Due to the high predisposition of methionine containing cyclolinopeptides to oxidation and the easiness of CLPs’ quantification with the proposed method, it is possible to reliably assess the extent of flaxseed meal and oil oxidation.     

Hydrometallurgical recovery of copper and cobalt from reduction-roasted copper converter slag

The paper is concerned with a simple hydrometallurgical method for selective recovery of copper and cobalt from industrial copper converter slag. The following consecutive stages are proposed: roasting of the slag in reduction conditions to produce Cu–Co–Fe–Pb alloy, electrolytic dissolution of the alloy in an ammonia–ammonium chloride solution, ammoniacal leaching of the slime, selective copper and cobalt electrowinning. Cu27–Co6–Fe64–Pb1.5 alloy was a five-phase system and did not dissolve uniformly during electrolysis. This resulted in the separation of the metals, wherein iron remained in the slime, while copper and cobalt were components of slime, electrolyte and cathodic deposit. A mechanism of the alloy dissolution was developed. A series of secondary processes took place in the system: precipitation of iron compounds, copper cementation with cobalt and iron; adsorption of copper and cobalt ions on the iron precipitates. Final products were metals of high purity (99.9% Cu, 92% Co).     

Effect of Fe3O4, Fe and Cu doping on magnetic properties and behaviour in physiological solution of biological hydroxyapatite/glass composites

The effect of Fe, Fe₃O₄ and Cu additives on magnetic properties and behaviour in physiological solution of glass-reinforced biological hydroxyapatite composites has been investigated. 1 wt% of additive was admixed before the final sintering of composites at 500 or 780 °C. The relative green and sintered densities of the samples were analyzed for the influence of additives and sintering temperature on the composite properties. The morphology of composites exhibited a porous structure with a pore size of 0.1–200.0 μm for OK 015 and 0.2–600.0 μm for OK 6 samples. It has been found that the magnetic properties of the doped composites depend on their compositions, the nature of additive and sintering conditions. The influence of the additive phases on the degradation of the composites in physiological solution was studied in vitro. It has been shown that Fe₃O₄-doped OK 015, which has ferromagnetic properties, can be the most suitable material for targeted delivery of drugs.     

Fluorescence of Colloidal Gold Nanoparticles is Controlled by the Surface Adsorbate

Fluorescent gold nanoparticles are important biological labels, in particular for combined optical and electron microscopy. It is reported that density and type of surface ligands have key influence on the dominant UV‐vis fluorescence band in positively and negatively charged gold nanoparticles capped with citrate, gold oxide, and cetyltrimethyl ammonium bromide (CTAB). The peak excitation and emission energies and fluorescence intensities vary with nanoparticle size, reflecting changes in surface charge and surface potential as well as a varying density of surface adsorbates. The fluorescence peak shifts, the evolution of zeta potentials, and fluorescence intensity trends are explained by a model of the principal fluorescence transitions that takes into account the nanoparticle surface conditions, such as the adhesion of ligands. Varying surface ligands is a simple strategy to optimize fluorescence intensity and to design spectral properties of gold nanoparticles.     

Discrimination of Salmonella enterica serotypes by Fourier transform infrared spectroscopy

Salmonella continues to be an important cause of foodborne infections in humans throughout the world. The precise nature of the infection depends on the specific combination of host and Salmonella serotypes, some of them being highly pathogenic. Fourier transform infrared (FT-IR) spectroscopy together with chemometric techniques were used in this study to discriminate closely related S. enterica serotypes. Intact cells of 26 different serotypes belonging to serogroups B, C1, C2–C3 and D1 (Enteritidis, Typhimurium, Bredeney, Goldcoast, Rissen, Hadar, Derby, Essen, Virchow, Mbandaka, Menden, Agona, Brikama, Saintpaul, Infantis, Braenderup, Mikawasima, Brandenburg, Heidelberg, Indiana, Norwich, Bardo, Bovismorbificans, Istanbul, Newport and Blockley) were examined by FT-IR spectroscopy in transmittance mode and classified based on the agglutination pattern reactions using the Kauffmann–White classification scheme. Using FT-IR spectra in the 1200–900 cm^? 1 range (outer membrane polysaccharides) allowed to correctly classify all isolates according to the four analysed serogroups. A discrimination analysis applied within each serogroup, demonstrated that it was also possible to differentiate between the different serotypes. Results demonstrate that application of FT-IR spectroscopy together with chemometric methods has considerable potential to effectively fulfil the current requirements for fast and straightforward differentiation of S. enterica serotypes.     

Kinetics of commercial olive oil oxidation: Dynamic differential scanning calorimetry and Rancimat studies

Four samples of olive oil were oxidized under polythermal (dynamic) conditions in the cell of a normal‐pressure differential scanning calorimeter (DSC) and in the Metrohm Rancimat apparatus. The DSC experiments were carried out in an oxygen flow atmosphere using different linearly programmed heating rates in the range of 4–20 °C/min. Through DSC exotherms, the extrapolated onset temperatures were determined and used for the assessment of the thermal‐oxidative stabilities of the samples. Using the Ozawa‐Flynn‐Wall method and the Arrhenius equation, the activation energies (E_a), pre‐exponential factors (Z) and reaction rate constants (k) for oil oxidation under DSC conditions were calculated. The Rancimat measurements of oxidation induction times were carried out under isothermal conditions in an air atmosphere at temperatures from 100 to 140 °C with intervals of 10 °C. Using the Arrhenius‐type correlation between the inverse of the induction times and the absolute temperature of the measurements, E_a, Z, and k for oil oxidation under Rancimat conditions were calculated. The primary kinetic parameters derived from both methods were qualitatively consistent and they help to evaluate the oxidative stabilities of oils at increased temperatures.     

Berlin and Warsaw: in search of a new role in the European urban system

After 1989, the cities of Central and Eastern Europe were engaged in an inter-urban competition, a process characteristic of the urban scene since the beginning of European integration. Being a topic of great interest to researchers, a large body of literature has accumulated on the observed role of capital cities in the region as well as on their potential role in the future. Several researchers have focused on the position as well as the interdependence of Berlin and Warsaw—two urban nodes in what is hypothesized as a future West–East development trajectory (see Domański, 1999). The present paper deals with the emergence and development of metropolitan functions in these two cities. It is based on a comparative research project, which involved a series of structured, in-depth interviews with planners and policy-makers in Germany and Poland conducted by the author during the period 2001–2003. The paper discusses the development factors and their contributions to the metropolitan potential of Berlin and Warsaw. The identification of these factors is a starting point for determining the future position and rank of these two capital cities in the European urban system. The analysis is complemented by a comparison of trends in the employment structure of Berlin and Warsaw during the period 1994–2002. The results allow the author to evaluate some hypotheses posed in strategic planning documents concerning Berlin and Warsaw.

Nano-Nutrition of Chicken Embryos. The Effect of in Ovo Administration of Diamond Nanoparticles and l-Glutamine on Molecular Responses in Chicken Embryo Pectoral Muscles

It has been demonstrated that the content of certain amino acids in eggs is not sufficient to fully support embryonic development. One possibility to supply the embryo with extra nutrients and energy is in ovo administration of nutrients. Nanoparticles of diamond are highly biocompatible non-toxic carbonic structures, and we hypothesized that bio-complexes of diamond nanoparticles with l-glutamine may affect molecular responses in breast muscle. The objective of the investigation was to evaluate the effect of diamond nanoparticle (ND) and l-glutamine (Gln) on expression of growth and differentiation factors of chicken embryo pectoral muscles. ND, Gln, and Gln/ND solutions (50 mg/L) were injected into fertilized broiler chicken eggs at the beginning of embryogenesis. Muscle tissue was dissected at day 20 of incubation and analysed for gene expression of FGF2, VEGF-A, and MyoD1. ND and especially Gln/ND up-regulated expression of genes related to muscle cell proliferation (FGF2) and differentiation (MyoD1). Furthermore, the ratio between FGF2 and MyoD1 was highest in the Gln/ND group. At the end of embryogenesis, Gln/ND enhanced both proliferation and differentiation of pectoral muscle cells and differentiation dominated over proliferation. These preliminary results suggest that the bio-complex of glutamine and diamond nanoparticles may accelerate growth and maturation of muscle cells.