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891.
The artificial-turf granulates made from recycled rubber waste are of health concern due the possible exposure of users to dangerous substances present in the rubber, and especially to PAHs. In this work, we determined the contents of PAHs, metals, non-dioxin-like PCBs (NDL-PCBs), PCDDs and PCDFs in granulates, and PAH concentrations in air during the use of the field. The purposes were to identify some potential chemical risks and to roughly assess the risk associated with inhalation exposure to PAHs. Rubber granulates were collected from 13 Italian fields and analysed for 25 metals and nine PAHs. One further granulate was analysed for NDL-PCBs, PCDDs, PCDFs and 13 PAHs. Air samples were collected on filter at two fields, using respectively a high volume static sampler close to the athletes and personal samplers worn by the athletes, and at background locations outside the fields. In the absence of specific quality standards, we evaluated the measured contents with respect to the Italian standards for soils to be reclaimed as green areas. Zn concentrations (1 to 19 g/kg) and BaP concentrations (0.02 to 11 mg/kg) in granulates largely exceeded the pertinent standards, up to two orders of magnitude. No association between the origin of the recycled rubber and the contents of PAHs and metals was observed. The sums of NDL-PCBs and WHO-TE PCDDs + PCDFs were, respectively, 0.18 and 0.67 × 10− 5 mg/kg. The increased BaP concentrations in air, due to the use of the field, varied approximately from < 0.01 to 0.4 ng/m3, the latter referring to worst-case conditions as to the release of particle-bound PAHs. Based on the 0.4 ng/m3 concentration, an excess lifetime cancer risk of 1 × 10− 6 was calculated for an intense 30-year activity.  相似文献   
892.
The lacrimal film has attracted increasing interest in the last decades as a potential source of biomarkers of physiopathological states, due to its accessibility, moderate complexity, and responsiveness to ocular and systemic diseases. High-performance liquid chromatography-mass spectrometry (LC-MS) has led to effective approaches to tear proteomics, despite the intrinsic limitations in sample amounts. This review focuses on the recent progress in strategy and technology, with an emphasis on the potential for personalized medicine. After an introduction on lacrimal-film composition, examples of applications to biomarker discovery are discussed, comparing approaches based on pooled-sample and single-tear analysis. Then, the most critical steps of the experimental pipeline, that is, tear collection, sample fractionation, and LC-MS implementation, are discussed with reference to proteome-coverage optimization. Advantages and challenges of the alternative procedures are highlighted. Despite the still limited number of studies, tear quantitative proteomics, including single-tear investigation, could offer unique contributions to the identification of low-invasiveness, sustained-accessibility biomarkers, and to the development of personalized approaches to therapy and diagnosis.  相似文献   
893.
The objective of this research is to study the influence of microstructure and grinding on the corrosion resistance of ADI in salt water. Immersion and electrochemical tests were performed on samples austempered at two different temperatures and ground. The results indicate that the dissolution rate increases as the nodule count does, and it is also affected by the microstructure and by the surface changes introduced during grinding. A porous layer is formed on ADI-corroded surface due to the selective dissolution of ferrite, and a preferential dissolution of the matrix around graphite is noticeable. Ground surfaces are less corrosion resistant than polished ones.  相似文献   
894.
This work introduces a simplified methodology for measuring the characteristic curvature (Cc) of commercial alkyl ethoxylate nonionic surfactants using carefully selected reference surfactants and oils that produce rapid and well defined separations in salinity scans. The Cc of the commercial reference surfactants was calculated using optimal salinities (S*) obtained from solubilization parameter curves, from interfacial tensions (for a selected system), and from emulsion stability tests. The latter provided a fast detection of S*, in a matter of minutes. The calibrated Cc of the reference surfactants was subsequently used to measure the Cc of various commercial alkyl ethoxylate surfactants. The combination of mixtures of test and reference surfactants and emulsion stability tests produced reproducible Cc values that could be obtained with simple bottle tests and in a timely manner. The values obtained using this methodology were cross‐checked, and proved to be consistent, when using different combinations of reference surfactants and oils, and when conducted by different individuals. The standard deviation of Cc from these measurements was typically ±0.2 Cc units, but it could be as large as 25 % of the Cc value for highly hydrophilic surfactants. After comparing the values of Cc obtained experimentally with values calculated from nominal structures (via a group contribution model) it became clear that there are differences between these values, likely because of the polydispersity of alkyl ethoxylate surfactants.  相似文献   
895.
896.
The on-lattice kinetic Monte Carlo (KMC) method provides a powerful tool to simulate the JV properties of organic solar cells. However, the computational cost associated with charge injection may limits its applicability. In the attempt to overcome this limitation, we describe in this paper a coarse-grained numerical approach to photocurrent generation in bilayer heterojunction solar cells. Starting from the KMC algorithm, a self-consistent numerical procedure is proposed to find the steady-state solutions of the kinetic equations describing particle dynamics in one dimension across the layer thickness. Our model incorporates the generation, transport and recombinations of charge carriers, excitons, and electron/hole pairs, whose introduction is required to correctly describe interfacial phenomena at the coarse-grained level. A continuum model of the electrostatic interactions among charge carriers is proposed and used to compute their hopping rates during the simulation. The model is used to investigate the JV properties of Cathode/PCBM/P3HT/PEDOT:PSS/ITO bilayer devices, showing that Fermi level pinning at the Cathode/PCBM interface must be invoked to accurately model the experimental behavior. From the fitting to the experimental JV data, we conclude the short-circuit current density to be mainly associated with a high exciton diffusion length. The analogies and differences between our model and existing KMC and drift–diffusion approaches are also discussed.  相似文献   
897.
Here we report a new technique, Correlative Light-Ion Microscopy (CLIM), to correlate SEM-like micrographs with fluorescence images. This technique presents significant advantages over conventional methods in enabling topographical and biochemical information to be correlated with nanoscale resolution without destroying the fluorescence signal. We demonstrate the utility of CLIM for a variety of investigations of cell substrate interactions validating its potential to become a routine procedure in biomedical research.  相似文献   
898.
Performance of DNA-based methods used for allergen detection does not only depend on the real-time PCR system, but also on the DNA isolation method used. Comparison of different isolation methods showed that yield and purity of isolated DNA strongly depends on the isolation method deployed as well as on the composition of the food matrix (matrix effect). Detection of trace amounts of allergens requires efficient methods for DNA isolation which remove inhibitors and yield pure DNA. This is particularly important for quantitative analysis. Due to matrix effects, methods, which have the ability to circumvent these effects, are of great interest. Therefore, a sequence-specific method for isolation of target DNA based on magnetic particles (MCH) has been established and compared to other methods for isolation of total DNA.  相似文献   
899.
The aim of this work was to emphasize the limitations of modeling complex phenomena under unrealistic model assumptions. As a case study, the whey protein hydrolysis mechanism was modeled. A stirred batch reactor was used to study the degree of hydrolysis of sweet whey protein concentrate by using the protease alcalase. A completely random two-factorial experimental design was used, three levels of initial enzyme concentrations (E 0) (1.58, 3.18, 6.36 AU (Anson units)/L) times three levels of initial substrate concentrations (S 0) (18.73, 38.45, 81.16 g/L). All treatments were carried out at optimal alcalase—activity conditions: pH 8 and 50 °C. Reactions were monitored for 180 min. The degree of hydrolysis (h) curves was finally adjusted for each treatment to the exponential model using nonlinear regression techniques but not assuming a Michaelis–Menten relationship. From the estimation process, the coefficient b was constant (27.26 ± 1.37) and independent of E 0 and S 0, while coefficient a depended directly on the ratio E 0/S 0, ranging from 0.0017 to 0.0497. A noncritical strategy of forward modeling based on unrealistic assumptions was misleading in the face of complex phenomena; instead, a modeling strategy moving from data to the identification and estimation of parameters of practical interest must be considered.  相似文献   
900.
White wine phenolic analyses are less common in the literature than analyses of red wine phenolics. Analytical techniques for white wine phenolic analyses using spectrophotometric, chromatographic, spectroscopic, and electrochemical methods are reported. The interest of research in this area combined with the advances in technology aimed at the winemaking industry are promoting the establishment of novel approaches for identifying, quantifying, and classifying phenolic compounds in white wine. This review article provides an overview of the current research into white wine phenolics through a critical discussion of the analytical methods employed. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   
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