The extent and the sources of contamination with brominated flame retardants (BFRs), such as polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD), in home-produced eggs from free-foraging chicken of Belgian private owners were investigated. Various factors, such as seasonal variability, exposure of chickens through diet (kitchen waste) and soil, and elimination of BFRs through eggs and faeces were assessed. PBDEs were more important than HBCD in terms of concentrations and detection frequency. Concentrations of PBDEs and HBCD in Belgian home-produced eggs were relatively low and comparable with reported levels from other European countries and the US. The concentrations of PBDEs (sum of 13 congeners, including BDE 209) ranged between not detected and 32 ng/g lipid weight (lw), with medians of 3.0 and < 2.0 ng/g lw for the autumn 2006 and spring 2007 campaigns, respectively. When present, BDE 209 was the major PBDE congener (45% of sum PBDEs). When BDE 209 was not detected, the PBDE profile was composed of PentaBDE (BDE 99 and BDE 47), with, in some cases, higher contribution of OctaBDE (BDE 183 and BDE 153). HBCD was also detected (< 0.4 and 2.9 ng/g lw for the autumn 2006 and spring 2007 campaigns, respectively), but at lower detection frequency. The highest HBCD value was 62 ng/g lw. The similarity between profiles and seasonal variations in the concentrations of BFRs in soil and eggs indicate that soil is an important source, but not the sole source, for eggs laid by free-foraging chicken. The contamination of eggs with PBDEs and HBCD appears to be of low concern for public health and the contribution of eggs to the total daily intake of PBDEs appears to be limited (10% for chicken owners and 5% for the average Belgian consumer). 相似文献
This paper discusses the role of government mortgage guarantee schemes in housing policy. It explores different types of government mortgage guarantee scheme, which play different roles, in eight countries. Mortgage guarantee schemes interfere in the mortgage market in order to improve access to mortgages. Such guarantees can be shaped as self-supporting instruments or as subsidies. If the latter is the case the issue of competition and a level playing field is relevant. This paper explores the US and the Dutch guarantee models in depth in order to answer the question of whether these schemes are unsubsidised mortgage market instruments or subsidised programmes. It concludes by reflecting on the meaning of the outcomes in the context of EU competition policy. 相似文献
Food Science and Biotechnology - Chemical properties of fish gelatins differ from those of conventional mammalian sources, representing an attractive technological alternative for the food... 相似文献
Nutritional studies are greatly hampered by a paucity of proper models. Previous studies on nutrition have employed conventional cell lines and animal models to gain a better understanding of the field. These models lack certain correlations with human physiological responses, which impede their applications in this field. Enteroids are cultured from intestinal stem cells and include enterocytes, enteroendocrine cells, goblet cells, Paneth cells, and stem cells, which mimic hallmarks of in vivo epithelium and support long‐term culture without genetic or physiological changes. Enteroids have been used as models to study the effects of diet and nutrients on intestinal growth and development, ion and nutrient transport, secretory and absorption functions, the intestinal barrier, and location‐specific functions of the intestine. In this review, the existing models for nutritional studies are discussed and the importance of enteroids as a new model for nutritional studies is highlighted. Taken together, it is suggested that enteroids can serve as a potential model system to be exploited in nutritional studies. 相似文献
In this work, the pentalithium ferrite was synthetized by solid-state method, and it was characterized by XRD and N2 adsorption–desorption techniques. Then, H2 production was obtained through a catalytic conversion process; chemical looping partial oxidation (CLPO) of methane using Li5FeO4 as multifunctional material. The catalytic decomposition of methane is an easy way to obtain clean energy, such as hydrogen, but in this process carbon deposition is also possible. The results showed that this material has the ability to convert methane to hydrogen, but it is also capable to donate oxygen atoms from its crystalline network, producing carbon monoxide and/or carbon dioxide, limiting the carbon deposition on the ceramic surface. In addition, it was demonstrated that this lithium-based ceramic produces hydrogen over a wide temperature range (550–900 °C), with a stable hydrogen production for 3 h at 825 °C. Furthermore, it was possible to achieve a cyclic test of methane decomposition with a pre-oxidation process between each cycle obtaining an outstanding increase in hydrogen production from 10% in cycle 1 to ~?100% in the cycle 10. This previous stage not only induces an increase in the decomposition of methane, but also avoids carbon deposition accompanied by the production of both COX compounds. Finally, it must be mentioned that Li5FeO4 is capable to chemisorb both carbon oxides produced, promoting high purity hydrogen production.
Journal of Mechanical Science and Technology - Most soft pneumatic actuators require large pressures to realize their full deformations, have a non-negligible weight from their polymeric structures... 相似文献
Consumers demand, in addition to excellent eating quality, high standards of safety and nutrition in ready-to-eat food. This
requires a continuous improvement in conventional processing technologies and the development of new alternatives. Prevailing
technologies such as thermal processing can cause extensive and undesirable chemical changes in food composition while minimal
processing strategies cannot eliminate all microbial pathogens. This review focuses on pressure-assisted thermal processing,
a new alternative for shelf-stable foods. Its implementation requires an analysis of reaction kinetics at high pressure and
elevated temperature. Acceleration of the inactivation of bacterial spores by the synergistic effect of pressure and temperature
is expected to allow processing at lower temperature, shorter process time, or a combination of both. Therefore, thermal degradation
of quality is expected to be lower than that of conventional thermal processes. However, few studies have focused on the effect
of the conditions required for the inactivation of bacterial spores on the kinetics of chemical reactions degrading food quality,
particularly at the high temperatures required for the processing of low-acid foods. 相似文献
The limited industrial processing and export to European countries of fresh Mexican ‘Ataulfo’ mangoes is attributed in part to the lack of homogeneous ripening among fruit from the same lot. A viable technology to alleviate the situation is the application of exogenous ethylene. In this work, vacuum (34 kPa) was applied for 20 min to ‘Ataulfo’ mangoes that were later exposed to exogenous ethylene (500, 1000 and 1500 μL L−1) for 30 min and ripening was monitored. Application of vacuum did not produce apparent visual damage to the fruit; when 1500 μL L−1 ethylene were applied for 30 min after the vacuum, induced production of internal ethylene with a concomitant increase in respiration rate. Firmness and acidity loss proceeded faster after the fruits were exposed to vacuum and 1500 μL L−1 ethylene; similarly, total soluble solids increased and pulp and peel color development was 100% in the whole lot. An overall reduction of three days from the normal ripening time was observed attributed to the treatments. It is proposed that short exposures to vacuum and ethylene could improve the uniformity in mango ripening. 相似文献
Stem cells for regenerative medicine purposes offer therapeutic benefits, but disadvantages are still ill defined. The benefit of stem cells may be attributed to their secretion of growth factors (GFs), cytokines (CKs), and extracellular vesicles (EVs), including exosomes. We present a novel cell-free stem cell-derived extract (CCM), formulated from human progenitor endothelial stem cells (hPESCs), characterized for biologically active factors using ELISA, nanoparticle tracking analysis and single particle interferometric reflectance imaging sensing. The effect on fibroblast proliferation and ability to induce stem cell migration was analyzed using Alamar Blue proliferation and Transwell migration assays, respectively. GFs including IGFBP 1, 2, 3, and 6, insulin, growth hormone, PDGF-AA, TGF-α, TGF-β1, VEGF, and the anti-inflammatory cytokine, IL-1RA were detected. Membrane enclosed particles within exosome size range and expressing exosome tetraspanins CD81 and CD9 were identified. CCM significantly increased cell proliferation and induced stem cell migration. Analysis of CCM revealed presence of GFs, CKs, and EVs, including exosomes. The presence of multiple factors including exosomes within one formulation, the ability to promote cell proliferation and induce stem cell migration may reduce inflammation and pain, and augment tissue repair. 相似文献