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61.
BACKGROUND: Limited research suggests that brown seaweed (extracts) may be used in pig nutrition for improving gut health and performances and for iodine enrichment of tissues. One in vitro and two in vivo experiments with dried iodine‐rich intact marine seaweed (Ascophyllum nodosum) have been conducted with weaned piglets to further unravel the mechanisms. RESULTS: In vitro investigations revealed a statistically significant depressive effect of seaweed on pig gut flora, especially on Escherichia coli. In vivo, seaweed (10 g kg?1) had a reducing effect on the E. coli load in the stomach (P = 0.07) and small intestine (P < 0.05), while the lactobacilli/E. coli ratio was enhanced (P < 0.05) in the small intestine, indicating a beneficial shift in the microbial population. Statistically significant increases (P < 0.001) in iodine content were noted for several tissues in piglets on seaweed (20 g kg?1, corresponding to 10 mg iodine kg?1 feed) compared with the control diet (1 mg iodine kg?1 feed). CONCLUSION: Intact A. nodosum brown seaweed may be introduced in pig nutrition as a feed material with a double strategy: improvement of pig gut health and performances and iodine enrichment of porcine tissues. This feeding strategy may alleviate, but not solve, the actual iodine deficiency in Belgium. Copyright © 2009 Society of Chemical Industry  相似文献   
62.
Dietary intake assessment can be considered as a two-step process consisting of collecting and evaluating food composition data, and combining these data with food consumption data. The purpose of this study was to develop databases of nutrient and contaminant concentrations in organic and conventional vegetables and potatoes based on internationally available secondary data. Databases, as described here, are important in (1) comparing the composition of similar foods (organic versus conventional) and (2) assessing probabilistically the combined intake of nutrients and contaminants when nutritional and toxicological dimensions of food consumption are being studied simultaneously.  相似文献   
63.
Food intake is one of the principal exposure routes of polybrominated diphenyl ethers (PBDEs) in humans. This study focuses on fish consumption as a PBDE exposure route. A probabilistic intake assessment of PBDEs and healthy long chain omega-3 PUFAs (LC n-3 PUFAs) was conducted for Belgian fish consumers in order to study the balance of the intake of LC n-3 PUFAs and PBDEs. Based on the observed fish consumption level in the sample, the mean intake of brominated diphenyl ether (BDE)-28, 47, 99, 100, 153, and 154 via fish was 0.85 ng/kg body weight (bw)/day and the intake of LC n-3 PUFAs was 3.45 mg/kg bw/day, being low compared to the recommendations. Scenario analyses showed that consuming 150 g salmon twice a week is advisable to achieve the recommended LC n-3 PUFA intake with a rather low PBDE intake. When replacing 150 g salmon by herring, the PBDE intake is higher without an increase in LC n-3 PUFAs. In contrast, the combination of cod and salmon leads to a similar PBDE intake compared to twice a week salmon, but to a lower LC n-3 PUFA intake. In conclusion, the methodology presented in the paper allows balancing benefits and risks related to fish consumption.  相似文献   
64.
Accurate sizing of nanoparticles in biological media is important for drug delivery and biomedical imaging applications since size directly influences the nanoparticle processing and nanotoxicity in vivo. Using fluorescence single particle tracking we have succeeded for the first time in following the aggregation of drug delivery nanoparticles in real time in undiluted whole blood. We demonstrate that, by using a suitable surface functionalization, nanoparticle aggregation in the blood circulation is prevented to a large extent.  相似文献   
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The ratio of n‐6 over n‐3 fatty acids (FA) in the Western diet is today on average between 10 and 15, while evidence suggests that humans would benefit substantially from a more balanced intake. Different strategies to reverse this trend can potentially be adopted. This paper explores the effect of n‐3 enrichment at the level of primary animal production on human FA intake. Consumption data from adolescents were linked to ‘currently available’ and to simulated ‘enriched’ FA profiles of foods from animal origin (by feeding α‐linolenic‐rich diets to pigs, dairy and beef cattle, and broiler and layer chickens). Under enriched conditions, population intakes for α‐linolenic acid and for all n‐3 FA shifted to recommended values. For long‐chain n‐3 polyunsaturated FA, the favourable trend in intake was not sufficient to meet recommendations. The effect on other FA was small. The n‐6/n‐3 ratio decreased considerably from an average value of 6.6 to 4.6. It is concluded that feasible and realistic n‐3 FA enrichments of foods from animal origin can add substantially to the overall efforts for reducing the n‐6/n‐3 intake ratio in the population. However, foods rich in long‐chain n‐3 FA remain essential in the human diet under such conditions. Copyright © 2006 Society of Chemical Industry  相似文献   
67.
Although charge‐carrier selectivity in conventional crystalline silicon (c‐Si) solar cells is usually realized by doping Si, the presence of dopants imposes inherent performance limitations due to parasitic absorption and carrier recombination. The development of alternative carrier‐selective contacts, using non‐Si electron and hole transport layers, has the potential to overcome such drawbacks and simultaneously reduce the cost and/or simplify the fabrication process of c‐Si solar cells. Nevertheless, devices relying on such non‐Si contacts with power conversion efficiencies (PCEs) that rival their classical counterparts are yet to be demonstrated. In this study, one key element is brought forward toward this demonstration by incorporating low‐pressure chemical vapor deposited ZnO as the electron transport layer in c‐Si solar cells. Placed at the rear of the device, it is found that rather thick (75 nm) ZnO film capped with LiFx/Al simultaneously enables efficient electron selectivity and suppression of parasitic infrared absorption. Next, these electron‐selective contacts are integrated in c‐Si solar cells with MoOx‐based hole‐collecting contacts at the device front to realize full‐area dopant‐free‐contact solar cells. In the proof‐of‐concept device, a PCE as high as 21.4% is demonstrated, which is a record for this novel device class and is at the level of conventional industrial solar cells.  相似文献   
68.
Sodium-ion batteries (SIBs) are a possible candidate to create safe, sustainable, and cost-effective batteries. Solid sodium-ion conducting organically modified ionogel electrolytes are investigated. Silica-based ionogels typically consist of an ionic liquid electrolyte (ILE) confined within a silica matrix and possess high thermal stability, good ionic conductivity, safety, and good electrochemical stability. However, they readily deteriorate when stress is applied, decreasing the electrolyte's and battery's overall performance. The mechanical characteristics of silica can be improved using organic moieties, creating Ormosils®. Silica-based ionogels with phenyl-modified silanes improve the mechanical characteristics by a reduction of their Young's modulus (from 29 to 6 MPa). This is beneficial to the charge-transfer resistance, which decreases after implementing the electrolyte in half cells, demonstrating the improved interfacial contact. Most importantly, the phenyl groups change the interacting species at the silica interface. Cationic imidazolium species pi-stacked to the phenyl groups of the silica matrix, pushing the anions to the bulk of the ILE, which affects the ionic conductivity and electrochemical stability, and might affect the quality of the SEI in half cells. In essence, the work at hand can be used as a directory to improve mechanical characteristics and modify and control functional properties of ionogel electrolytes.  相似文献   
69.
The "layer-by-layer" (LbL) technology has been widely investigated for the coating of flat substrates and capsules with polyelectrolytes. In this study, LbL polyelectrolyte coatings applied at the surface of digitally encoded microcarriers were evaluated for the quantitative, sensitive, and simultaneous detection of proteins in complex biological samples like serum, plasma, and blood. LbL coated microcarriers were therefore coupled to capture antibodies, which were used as capture agents for the detection of tumor necrosis factor (TNF-alpha), P24, and follicle stimulating hormone (FSH). It was found that the LbL coatings did not disassemble upon incubating the microcarriers in serum and plasma. Also, nonspecific binding of target analytes to the LbL coating was not observed. We showed that the LbL coated microcarriers can reproducibly detect TNF-alpha, P24, and FSH down to the picogram per milliliter level, not only in buffer but also in serum and plasma samples. Microcarrier-to-microcarrier intratube variations were less then 30%, and interassay variations less than 8% were observed. This paper also shows evidence that the LbL coated digitally encoded microcarriers are ideally suited for assaying proteins in "whole" blood in microfluidic chips, which are of high interest for "point-of-care" diagnostics.  相似文献   
70.
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