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Hidden fumonisins have received great attention in the last years as they have been frequently found in maize products in addition to the free forms. Several papers have shown that interaction with macromolecular components such as protein and starch is at the base of the phenomenon: although the nature of the interaction (covalent or not) is still not clarified, the occurrence of hidden forms is generally revealed by the application of an alkaline hydrolysis procedure. In this study, an in vitro digestion model has been applied to raw maize to evaluate the possible release of hidden fumonisins under gastrointestinal conditions. Upon digestion of the food matrix, an increased amount of total detectable fumonisins was observed in comparison with the analysis on the nondigested matrix, an amount even higher than that calculated through the application of the hydrolysis procedure. Besides the analytical issues, our data have serious implications, since consumers may be exposed to a systematic higher risk than that estimated by conventional techniques.  相似文献   
13.
Two previously developed platforms, a multiplex polymerase chain reaction (PCR) and a peptide nucleic acid (PNA) array, the former allowing for the simultaneous detection of five transgenes and two endogenous controls in food and feed matrices and the latter for the assessment of the identity of amplified PCR products, were combined in order to develop a PNA array device for the screening of genetically modified organisms (GMOs) in food. PNA probes were opportunely designed, synthesized, and deposited on commercial slides. The length of the probes as well as the distance of the probes from the surface were evaluated and found to be critical points. The most suitable probes were found to be 15-mer PNAs linked to the slide surface by means of two 2-(2-aminoethoxy)ethoxyacetic acids as spacers. The device was tested on a model system constituted by flour samples containing a mixture of standards at known concentrations of transgenic material, in particular Roundup Ready soybean and Bt11, Bt176, Mon810, and GA21 maize: The DNA was amplified using the specific multiplex PCR method and tested on the PNA array. The method proposed was found to be able to correctly identify every GMO present in the tested samples.  相似文献   
14.
The experiment was designed to evaluate the effects of housing system and short-term transportation on the pituitary and adrenal response and on blood progesterone concentrations of beef cattle. Since the use of steroid hormones in farm animals has been banned in the EU (Council Directive 96/22/EC), it seems important to study the possible modifications in serum progesterone concentrations induced by stress in cattle. Thirty-two, 6 months old male Piedmontese beef cattle (16 reared in a littered loose house, Group A, and 16 housed in a littered tying stall barn, Group B) were blood sampled at T1 (6 months old), T2 (12 months old), T3 (18 months old, before transportation to the slaughterhouse) and T4 (after transportation to the slaughterhouse) in order to measure hormonal concentrations and lymphocyte glucocorticoid (GR) and β-adrenergic (β-AR) receptor concentrations. Circulating hormone concentrations were measured using commercial radioimmunoassay kits, whereas lymphocyte receptor density was determined through binding assays. In beef cattle housed in tie stall barn a significant increase in serum cortisol concentration was observed at T3, whereas there was no effect of the housing system on blood progesterone concentrations. Short-term transportation caused a significant increase in blood cortisol and catecholamine concentrations in both groups, whereas lymphocyte GR and β-AR significantly decreased in Group A. Our data confirm the activation of the hypothalamic-pituitary-adrenal axis and the catecholaminergic system in short-term transportation and suggest that the stress-induced increase in circulating progesterone concentrations does not exceed the limit established by pending legislation.  相似文献   
15.
Canine cognitive dysfunction syndrome (CDS) is a neurodegenerative disorder of aged dogs characterized by a progressive decline in cognitive function. In humans and laboratory animals, a variety of neurotransmitter abnormalities have been described in patients affected by age-related dementia. Specifically, the regulatory role of the catecholaminergic, serotonergic, and cholinergic systems has been outlined. The aim of the present study was to measure blood monoamine levels, platelet α2-adrenergic receptors, and lymphocyte muscarinic receptors in healthy adult and aged dogs and in dogs affected by canine cognitive dysfunction. Based on clinical and behavioral examination, 40 dogs were divided into 3 groups: healthy adults (n = 14), aged dogs (n = 17), and aged dogs affected by canine cognitive dysfunction (n = 9). A significant reduction in plasma levels of norepinephrine and dopamine was observed both in aged dogs (0.16 ± 0.02 ng/mL, P < 0.01; 0.11 ± 02 ng/mL, P < 0.01, respectively) and in CDS dogs (0.14 ± 0.03 ng/mL, P < 0.05; 0.10 ± 00.005 ng/mL, P < 0.01, respectively) compared with adults (0.29 ± 0.04 ng/mL and 0.15 ± 0.02 ng/mL, respectively). No significant differences were observed among groups for α2-adrenergic receptor concentrations. Canine lymphocytes express 2 distinct classes of muscarinic receptors, characterized by high (HA) and low affinity (LA) for [3H]-N-methyl-scopolamine. A significant age-dependent decrease in HA muscarinic receptors was observed. However, no differences were found between aged dogs (87.65 ± 11.08 sites/cell × 102) and in CDS dogs (90.17 ± 6.75 sites/cell × 102 ) for HA muscarinic receptor concentrations. As far as LA muscarinic receptors are concerned, CDS dogs showed a significant increase (393.48 ± 63 sites/cell × 102; P < 0.05) with respect to healthy adult dogs (188.84 ± 16.50 sites/cell × 102). Our results suggest that the reduction in HA muscarinic receptor-binding sites could be representative of the physiological aging process, whereas the increase in lymphocyte LA muscarinic receptor levels could be related to the cognitive decline.  相似文献   
16.
The textile industry is known to generate large quantities of effluents contaminated with dyes that are not fixed to the fibers during the dyeing process. The available technologies to remove these dyes from the wastewater are expensive and ineffective. Within this context, low-cost, easy-maintenance technologies for the removal of dyes have been studied, such as adsorption on aquatic macrophytes. Thus, the macrophyte Salvinia sp., raw or pretreated with NaOH or H3PO4, was used as biosorbent of Blue 5G reactive dye. The study showed that pH and temperature affect the dye removal capacity. The analysis of the infrared spectrum (FTIR) showed that chemical treatment of the Salvinia sp. modified the biomass surface and affected dye adsorption capacity. The pseudo-second-order kinetic model satisfactorily described the experimental data for raw and NaOH-pretreated biomass, and the pseudo-first-order model was more appropriate to describe the experimental data obtained with H3PO4-pretreated biomass. The highest capacity of Blue 5G dye removal was obtained with raw biomass, at 333?K and pH?1.0, with 98.35?% adsorption.  相似文献   
17.
Terrestrial ecosystems represent a major sink for atmospheric carbon (C) and temperate forests play an important role in global C cycling, contributing to lower atmospheric carbon dioxide (CO2) concentration through photosynthesis. The Intergovernmental Panel of Climate Change highlights that the forestry sector has great potential to decrease atmospheric CO2 concentration compared to other sectoral mitigation activities. The aim of this study was to evaluate CO2 sequestration (CO2S) capability of Fagus sylvatica (beech) growing in the Orfento Valley within Majella National Park (Abruzzo, Italy). We compared F. sylvatica areas subjected to thinning (one high-forest and one coppice) and no-management areas (two high-forests and two coppices). The results show a mean CO2S of 44.3 ± 2.6 Mg CO2 ha?1 a?1, corresponding to 12.1 ± 0.7 Mg C ha?1 a?1 the no-managed areas having a 28% higher value than the managed areas. The results highlight that thinning that allows seed regeneration can support traditional management practices such as civic use in some areas while no management should be carried out in the reserve in order to give priority to the objective of conservation and naturalistic improvement of the forest heritage.  相似文献   
18.
A demographic analysis of the night shark (Carcharhinus signatus) was carried out to establish the conservation status of this species caught by longlines on oceanic banks off northeastern Brazil. The biological input parameters (age at first maturity, longevity, fecundity and natural mortality) used for the construction of life tables were taken randomly from their respective probability distributions, taking into account the uncertainty of the parameter estimates by employing Monte Carlo simulations. Nine scenarios were generated from natural (M), total (Z), initial (Z0—corresponding to the first year of life of the cohort) and population equilibrium (Z′) mortality rates. Each scenario was executed 1000 times, varying the vital input rates for the estimation of the demographic parameters (net reproductive rate, R0; mean generation length, G; and intrinsic rate of population increase, r). Age at first maturity for C. signatus is 10 years; 89.2% of the stock is made up of juveniles, with fishery recruitment beginning at 5 years of age. The scenarios reveal that catches prior to first sexual maturity result in a significant reduction in population (−8.1%/year) and that the population would only support current efforts if the individuals caught are over 10 years of age or if mortality due to fishing efforts corresponded to the equilibrium rate beginning with recruitment at 5 years of age. A low survival rate is estimated for the first year of life. In order for the population to remain in equilibrium with current mortality rates and recruitment age, survival should be around 0.9. The combination of a low initial survival rate, low fecundity, fishery efforts and the large number of juveniles caught indicates that the C. signatus population off northeastern Brazil is being overexploited.  相似文献   
19.
Leguminous trees have a potential for phytoremediation of oil-contaminated areas for its symbiotic association with nitrogen-fixing bacteria and arbuscular mycorrhizal fungi (AMF). This study selects leguminous tree associated with symbiotic microorganisms that have the potential to remediate petroleum-contaminated soil. Seven species of trees were tested: Acacia angustissima, Acacia auriculiformis, Acacia holosericea, Acacia mangium, Mimosa artemisiana, Mimosa caesalpiniifolia, and Samanea saman. They were inoculated with AMF mix and nitrogen-fixing bacteria mix and cultivated over five oil levels in soils, with five replicates. The decreasing of total petroleum hydrocarbons (TPH) values occurred especially with S. saman and its symbiotic microorganisms on highest oil soil contamination. Despite the large growth of A. angustissima and M. caesalpiniifolia on the highest level of oil, these species and its inoculated microorganisms did not reduce the soil TPH. Both plants were hydrocarbon tolerant but not able to remediate the polluted soil. In contrast were significative hydrocarbon decrease with M. artemisiana under high oil concentrations, but plant growth was severely affected. Results suggest that the ability of the plants to decrease the soil concentration of TPH is not directly related to its growth and adaptation to conditions of contamination, but the success of the association between plants and its symbionts that seem to play a critical role on remediation efficiency.  相似文献   
20.
The occurrence of fluoride in groundwater has been reported in many countries, mainly because the excess fluoride in drinking water can lead to dental or skeletal fluorosis. Fluoride removal by coagulation with Moringa oleifera seeds, followed by separation with membranes, was investigated in this work. Artificially fluoridated water, at a starting fluoride concentration of 10?mg?L?1, was submitted to a coagulation process with aqueous extracts of M. oleifera seeds. The coagulation process was followed by ultrafiltration with membranes at different pressures. The coagulation process with 2.5?g?L?1 of M. oleifera promoted a reduction of 90.90?% in the fluoride content of the treated water, making it possible for poor communities to consume this water. It is noteworthy that the combined coagulation/filtration process using raw coagulant showed the highest values of colour and turbidity, which, however, were still below the limits set for drinking water by Brazilian legislation. The advantage of proposing a sequential process using membrane separation is that it removes colour and turbidity, caused by the use of M. oleifera as a coagulant, resulting in water that meets potability standards.  相似文献   
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