Some factors influencing biogenic amines and polyamines content in Dutch-type semi-hard cheese

Biogenic amines (BA; histamine, tyramine, tryptamine, phenylethylamine, cadaverine) and polyamines (PA; putrescine, spermidine, spermine) content was determined in Dutch-type semi-hard cheese (ripening 176 days) using an experimental design two producers × two starter cultures × two fat contents. Content of quantitatively most important BA (tyramine and histamine) and PA (putrescine) in the cheese samples at the end of ripening varied in the range 5–392 and 22–59, and 1–132 mg kg⁻¹, respectively. Time of ripening accounted for (P < 0.01) 67, 67 and 76% of the explained variability of histamine, tyramine, and putrescine content, respectively. Histamine, tyramine, and putrescine content in cheese (Y, mg kg⁻¹) increased (P < 0.01) linearly with increasing time of ripening (X, days): Y = 0.24X−1.3 (R ² = 0.28), Y = 0.69X−18.9 (R ² = 0.24) and Y = 0.16X−1.3 (R ² = 0.04), respectively. Biogenic amines (sum of BA) were produced more than three times more rapidly with increasing time of ripening in the edge part of the cheese than in the core part. Both histamine and tyramine content in cheese was negatively correlated (P < 0.01) with counts of lactic acid bacteria (LAB) and counts of total anaerobes, respectively. Accordingly, only 3% of both LAB and enterococci (established tyramine producers) isolates were positive on tyrosine decarboxylase gene sequences using the PCR method.     

ULTIMA: Magnetic Field Dependence of the Calibration Factor

ULTIMA is a project which proposes to use superfluid ³He as a sensitive medium for direct dark matter search. In this paper we report on new, detailed calibrations of our bolometric cells as a function of the magnetic field. An influence on the order of 20% on the peak height after an energy deposition is observed for magnetic fields up to 330 mT. Simultaneous measurements of neutron capture and heater events, releasing both a well defined energy, show that the effect is similar for both, and that it is possible to maintain a good calibration by an appropriate correction.      

Mathematical and Numerical Modelling of Microconvection in the Long Rectangular Domains

The thermal gravitational convection of liquids under conditions of microgravity is studied in a 2D long rectangular domain elongated in the direction of the gravity force. The liquid is located between two solid regions of equal thickness. The solid parts are heat conducting. The mathematical modelling of the coupled problem is presented. Two mathematical models of convection are used to describe a motion of liquid: the classical Oberbeck-Boussinesq model and the microconvection model of isothermally incompressible liquid. The numerical experiments of convection are performed and demonstrate the qualitative and quantitative differences in the flow characteristics.     

A statistical-thermodynamic model for ordering phenomena in thin film intermetallic structures

Ordering phenomena in bcc (110) binary thin film intermetallics are studied by a statistical-thermodynamic model. The system is modeled by an Ising approach that includes only nearest-neighbor chemical interactions and is solved in a mean-field approximation. Vacancies and anti-structure atoms are considered on both sublattices. The model describes long-range ordering and simultaneously short-range ordering in the thin film. It is applied to NiAl thin films with B2 structure. Vacancy concentrations, thermodynamic activity profiles and the virtual critical temperature of order-disorder as a function of film composition and thickness are presented. The results point to an important role of vacancies in near-stoichiometric and Ni-rich NiAl thin films.     

Evaluation of Contaminant Resuspension Potential during Cap Placement at Two Dissimilar Sites

Capping is a common remediation technology for the containment/stabilization of contaminated sediments. During capping activities, clean material is commonly released from a barge at the water surface and falls through the water column to the sediment surface, providing an uncontaminated surface sediment layer. Little information exists on the potential release of in situ contaminated sediments during and after capping operations. This paper focuses on the measured release of contaminants during capping events at Boston Harbor, Mass. (confined aquatic disposal cells for contaminated sediment) and Eagle Harbor, Wash. (creosote-contaminated sediment from a wood treating facility). The water column was sampled during capping events to evaluate whether cap placement resulted in the release of polycyclic aromatic hydrocarbons (PAH)- or polychlorinated biphenyls (PCB)-contaminated sediments at Boston Harbor, or PAH-contaminated sediments at Eagle Harbor. Though results at both sites indicated some contaminant resuspension during capping operations, in general contaminant resuspension was relatively low for all capping events. PCB and PAH concentrations for most samples were in the low ng/L range. The most significant releases occurred when previously uncapped sediments were initially capped, and the magnitude of contaminant resuspension decreased with successive capping layers. These results may have important implications regarding sediment cap installation techniques and their potential impacts on water quality. Resuspension during capping may be minimized by placing cap material in lifts, where the first lift provides a uniform layer of clean material using techniques that minimize sediment disturbance and subsequent lifts are placed more aggressively once contaminated sediment is covered.     

Glycosidic aroma compounds of some Portuguese grape cultivars

In order to evaluate the potential aroma of some Portuguese grapes, several glycosidically bound aroma compounds of ten grape varieties grown in Évora, Alentejo, Portugal, were released, identified and quantified using gas chromatography–mass spectrophotometry. White varieties were Arinto, Perrum, Rabo‐de‐Ovelha, Roupeiro and Antão Vaz. Red varieties were Trincadeira, Aragonez, Tinta Caiada, Moreto and Castelão. Grapes of Roupeiro and Trincadeira from five other vines in the Alentejo region were also studied. For each variety pulp and skin were analyzed separately. The compounds produced by enzymatic hydrolysis of glycoside precursors extracted from pulps and skins of these grapes were similar to the ones appearing in the so‐called ‘aromatic’ varieties; however, the amounts found were significantly lower. These results seem to show the neutral characteristic of these grapes to indicate that each variety has a distinctive profile regarding compounds from the linalool class. The ratios of trans : cis forms of some linalool compounds remain the same in all samples of Roupeiro and Trincadeira, regardless their origin. In Trincadeira grapes no linalool was detected. Skins are always richer than pulps. The acid hydrolysis of norisoprenoid aglycons produced highly odorant compounds previously described in grape varieties. Although some differences between varieties could be detected, the red grapes Aragonez and Castelão are richer in vitispiranes while Moreto, Trincadeira and Tinta Caiada are richer in actinidols; in white grapes, only Roupeiro and Perrum show detectable amounts of vitispiranes. These results need further investigation and analysis to be considered as a statement and should be confirmed in an extended study. Copyright © 2006 Society of Chemical Industry     

Micellar Hyaluronidase and Spiperone as a Potential Treatment for Pulmonary Fibrosis

Concentration of hyaluronic acid (HA) in the lungs increases in idiopathic pulmonary fibrosis (IPF). HA is involved in the organization of fibrin, fibronectin, and collagen. HA has been proposed to be a biomarker of fibrosis and a potential target for antifibrotic therapy. Hyaluronidase (HD) breaks down HA into fragments, but is a subject of rapid hydrolysis. A conjugate of poloxamer hyaluronidase (pHD) was prepared using protein immobilization with ionizing radiation. In a model of bleomycin-induced pulmonary fibrosis, pHD decreased the level of tissue IL-1β and TGF-β, prevented the infiltration of the lung parenchyma by CD16⁺ cells, and reduced perivascular and peribronchial inflammation. Simultaneously, a decrease in the concentrations of HA, hydroxyproline, collagen 1, total soluble collagen, and the area of connective tissue in the lungs was observed. The effects of pHD were significantly stronger compared to native HD which can be attributed to the higher stability of pHD. Additional spiperone administration increased the anti-inflammatory and antifibrotic effects of pHD and accelerated the regeneration of the damaged lung. The potentiating effects of spiperone can be explained by the disruption of the dopamine-induced mobilization and migration of fibroblast progenitor cells into the lungs and differentiation of lung mesenchymal stem cells (MSC) into cells of stromal lines. Thus, a combination of pHD and spiperone may represent a promising approach for the treatment of IPF and lung regeneration.     

Evidence for η6 Coordination to a Fullerene

Evidence for the first η⁶ derivative of a fullerene, [MoC₆₀F₁₈(CO)₃] has been obtained from reaction between [Mo(CH₃CN)₃(CO)₃] and C₆₀F₁₈.     

Effect of the Dimensional Factor on Sintering Composites of the System W – Sc2O3

The effect of adding fine scandium oxide (1, 5, and 10 vol.% in relation to the metal) on shrinkage kinetics during sintering of tungsten powder with an average particle size of 4 μm and 140 nm is studied. Specimens of coarse and fine powders are sintered at 1800-2000 and 1000-1200°C, respectively. The results obtained are explained on the basis of the Skorokhod structural model for composite mixtures that takes account of the dimensional factor of components and the level of the matrix microstructure. It is established that the lower the level of the latter and consequently the greater the level of the carcass formation, the greater is the effect of a slowdown in volumetric shrinkage with the same volume content of oxide addition.