A rapid differentiation between oak honeydew honey and nectar and other honeydew honeys by NMR spectroscopy

An NMR-based approach for rapid differentiation of oak honeydew honey from all other honey types (floral and other honeydew honeys) was proposed. It is based on the identification of the signals of the protons and the carbon of the methylene group of quercitol in the ¹H and ¹³C NMR spectra of honey. The presence of quercitol was supported by TOCSY spectroscopy. Quercitol is a deoxyinositol which is regarded as a good taxonomic marker for the genus Quercus. All samples of oak honeydew honey contained quercitol, while in floral honey samples and honeydew honeys from fir and spruce it was absent. In addition, the described approach is promising with respect to quercitol quantification in honey by qNMR.     

Effects of nickel foam dimensions on catalytic activity of supported Co–Mn–B nanocomposites for hydrogen generation from stabilized borohydride solutions

In the present work, the catalytic activity of electrodeposited Co–Mn–B nanocomposites towards controllable hydrolysis of sodium borohydride was studied. Deposition was performed on two types of Ni-foam (RECEMAT Int.) with different pore size, specific surface area and thickness. Higher deposit loading, as well as bigger real surface area, was obtained with foam samples possessing bigger pore size. The catalyst deposited on bigger pore foam promoted hydrogen generation with higher rates than the other one when contacted with a base-stabilized NaBH₄ solution. The same activation energy value, however, was determined for both supported catalysts. On the base of the obtained results, it may be concluded that the geometric factor plays predominant role for the catalytic activity of studied catalysts.     

Flow control in distributed gateways

The resultant traffic flows in a preferred direction within a set of cooperative gateway nodes is optimized taking into consideration the internal rate-delay products. The internal rates on directed links among adjacent gateway nodes are included in the set of control variables. It is also shown that the optimal internal rate-delay product of a set of connected gateway nodes can be obtained by locally optimizing in each node the rates of either the input ports or the output ports. The effectiveness of the proposed optimization algorithm is demonstrated for a typical sample gateway of three nodes with inhomogeneous arrival and service rates.     

Proteomic Helicobacter pylori biomarkers discriminative of low-grade gastric MALT lymphoma and duodenal ulcer

To date no reliable diagnostic method exists to predict, among the very large and clinically heterogeneous group of Helicobacter pylori‐infected patients, the extremely small group at risk for developing low‐grade gastric MALT lymphoma (LG‐MALT). Search of proteomic biomarkers holds promise for the classification of the H. pylori strains with regard to this severe clinical outcome. In the present study 69 H. pylori strains isolated from patients with two different H. pylori‐associated diseases, duodenal ulcer (DU, n=29) and LG‐MALT (n=40) were used. Protein expression patterns of the strains were analyzed by using the high‐throughput methodology SELDI. Selected proteins were purified by means of chromatographic and electrophoretic methods in view of further sequencing by LC‐MS/MS. Univariate analysis (Mann–Whitney test) of the protein expression patterns generated nine significant biomarkers that can discriminate between H. pylori strains from patients with DU and LG‐MALT. These biomarkers are of low molecular weight, ranging from 6 to 26.6 kDa. Among them, two are overexpressed in LG‐MALT strains and seven – in DU strains. Two biomarker proteins, one overexpressed in LG‐MALT strains (13.2 kDa) and another one – overexpressed in DU strains (26.6 kDa), were purified to homogeneity and identified by using LC‐MS/MS as a 50S ribosomal protein L7/L12 and a urease subunit, respectively. These biomarkers can be included in novel protein arrays for the differential diagnosis of H. pylori‐associated clinical outcomes.     

Expression of an anther-specific chalcone synthase-like gene is correlated with uninucleate microspore development in Nicotiana sylvestris

The accumulation of ATP by preparations of plasma membranes enriched particles (PMEP) isolated from rat hepatocytes, murine splenocytes and human T-lymphocytes has been investigated after the binding of human and murine tumour necrosis factors (TNF alpha) to their specific receptors. The TNF alpha-induced expression of the nuclear oncogene c-myc in intact hepatocytes has been also studied. TNF alpha induced the marked biosynthesis of ATP on PMEP of hepatocytes and splenocytes within the first minute of incubation. The biosynthesis of ATP was independent of the activity of adenylate kinase and only occurred in the presence of all the components of aerobic phosphorylation and the electron acceptor, cytochrome C or diferric transferrin. The level of ATP on PM correlated with the degree of expression of the nuclear oncogene c-myc in the same target cells. Adriamycin totally suppressed the biosynthesis of ATP on PM and simultaneously inhibited the expression of c-myc. The ATP synthesized on PM is suggested to be involved in transduction of the proliferative or growth signal to the cell nucleus.     

Templated Pt-Sn electrocatalysts for ethanol, methanol and CO oxidation in alkaline media

In this work, we have investigated an aerosol-derived templated electrocatalyst for electro-oxidation of small organic molecules in alkaline media. Templated Pt-Sn electrocatalysts are compared to templated Pt catalysts both synthesized in an aerosol synthesis technique. In this synthesis approach, mono-disperse silica nanoparticles are used to template the metallic precursors. Structural and compositional analysis of the nanostructured materials are performed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and BET surface area measurements. The aerosol-derived templated electrocatalysts are examined in conjunction with an anion exchange ionomer for ethanol, methanol and CO oxidation in alkaline media. The electrochemical studies include cyclic voltammetry, chronoamperometry and voltammetric adsorption of adsorbed CO.     

Importance of the Texture Index for Nickel Electrodeposits

Investigations of the properties of electrodeposited Ni-Mn-S layers are reported. The correlation between the texture, the texture index, and three groups of interactions, incorporated impurities, structural characteristics and mechanical properties, is described. It can be seen that the microhardness and ductility as well as the crystallite size and microdeformation correspond clearly to the texture index, whereas the impurities have no big influence on the texture development.

These results show that the texture index of the electroplated layers is not only an X-ray diffraction parameter, but it can very well describe the macroscopic materials properties.     

Radiation initiated grafting of acrylic acid onto tetrafluoroethylene–ethylene copolymers

Hydrophilic carboxyl containing fluoropolymers was obtained by radiation grafting of acrylic acid onto tetrafluoroethylene—ethylene copolymers with different compositions. By using simultaneous (⁶⁰Co) and preirradiation (electron beam) techniques, the effect of the grafting conditions (monomer concentration, dose rate, dose, film thickness, etc.) on the degree of grafting was studied. A considerable effect of the polymer compositions, especially the C? F bonds content, and the batch irradiation on the degree of grafting was found. It was observed by scanning electron microscopy that the grafting took place mainly on the polymeric film surface and developed inward with increasing diffusion of the acrylic acid through the grafted layers. © 1993 John Wiley & Sons, Inc.     

On the band diagram of Mg2Si/Si heterojunction as deduced from optical constants dispersions

The optical constant dispersions of ion-beam-synthesized Mg₂Si phase in Si matrix are obtained from the transmittance and reflectance spectra. Two types of samples are studied - one of them with Mg₂Si phase embedded in n-type (100)Si and the other with Mg₂Si phase embedded in p-type (100)Si. The formation of the phase is proved by Raman scattering and infrared transmittance measurements. From the interpretation of the optical constant dispersions, the energies of the transitions nearby the material band edge are determined. As a result the band diagram of the heterojunction Mg₂Si/Si is obtained. The results about the Mg₂Si band gap value are compared with the theoretically predicted and experimentally determined ones. The value of the conduction band offsets of Mg₂Si and Si is not reported by now.