Detection of lead in Zea mays by dual‐energy X‐ray microtomography at the SYRMEP beamline of the ELETTRA synchrotron and by atomic absorption spectroscopy

This study is related to the application of the X‐ray dual‐energy microradiography technique together with the atomic absorption spectroscopy (AAS) for the detection of lead on Zea mays stem, ear, root, and leaf samples. To highlight the places with lead intake, the planar radiographs taken with monochromatic X‐ray radiation in absorption regime with photon energy below and above the absorption edge of a given chemical element, respectively, are analyzed and processed. To recognize the biological structures involved in the intake, the dual‐energy images with the lead signal have been compared with the optical images of the same Z. mays stem. The ear, stem, root, and leaf samples have also been analyzed with the AAS technique to measure the exact amount of the hyperaccumulated lead. The AAS measurement revealed that the highest intake occurred in the roots while the lowest in the maize ears and in the leaf. It seems there is a particular mechanism that protects the seeds and the leaves in the intake process. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc. This article was published online on 1 December 2009. An error was subsequently identified. This notice is included in the online and print version to indicate that both have been corrected 19 February 2010.     

Human dietary exposure to heavy metals via the consumption of greenshell mussels (Perna canaliculus Gmelin 1791) from the Bay of Islands, northern New Zealand

Cadmium (Cd), mercury (Hg), arsenic (As), lead (Pb) and tin (Sn) concentrations were determined using ICP-MS in soft tissues (wet wt.) from whole greenshell mussels (Perna canaliculus) collected from Urapukapuka-Rawhiti Island, Opua Marina, Waitangi Bridge and Opua Wharf from the Bay of Islands, northern New Zealand (NZ). All samples had metal concentrations well below the Food Standards Australia and New Zealand (FSANZ) maximum limits and were comparable to, or less than, concentrations observed in previous NZ studies. Based on the average values detected in the current study, the concentrations of heavy metals ingested in a ‘typical diet’ containing greenshell mussels are below the provisional tolerable weekly intake (PTWI). However, Māori (indigenous people of New Zealand), Pacific Islanders and Asians consume a far greater quantity of seafood (and therefore heavy metals) than the general public of New Zealand and could potentially consume enough shellfish to exceed the PTWI for Cd (but not for Hg, As, Pb or Sn). Although our results, based on the current PTWIs, indicate no significant health risk to greenshell mussel consumers in this region, PTWIs change over time; concentrations which were thought to be safe are later found to be harmful. Additionally, differences in individual human susceptibilities to various toxins could increase the risk of harm for consumers with low tolerance to heavy metals. We suggest that a survey of the frequency, amount and species consumed by groups whose diet may be largely shellfish-based is required to enable a more comprehensive risk assessment to be made.     

Quantitative comparison of proteomic data quality between a 2D and 3D quadrupole ion trap

A 2D ion trap has a greater ion trapping efficiency, greater ion capacity before observing space-charging effects, and a faster ion ejection rate than a traditional 3D ion trap mass spectrometer. These hardware improvements should result in a significant increase in protein identifications from complex mixtures analyzed using shotgun proteomics. In this study, we compare the quality and quantity of peptide identifications using data-dependent acquisition of tandem mass spectra of peptides between two commercially available ion trap mass spectrometers (an LTQ and an LCQ XP Max). We demonstrate that the increased trapping efficiency, increased ion capacity, and faster ion ejection rate of the LTQ results in greater than 5-fold more protein identifications, better identification of low-abundance proteins, and higher confidence protein identifications when compared with a LCQ XP Max.     

Effects of pressure on poly(ether-ether-ketone) (PEEK) sintering mechanisms

This study deals with the understanding of the sintering mechanisms that occur during consolidation of an ultra-high-performance polymer: poly(ether-ether-ketone). In particular, we investigated the effects of uniaxial pressure during spark plasma sintering (SPS) processing. Glass-transition temperature (T_g) measurements under loading, stress–strain curves and scanning electron microscopy analysis allowed us to determine the role of pressure intensity and temperature of application on macromolecular chain mobility in both the bulk and the surface of the particles. First, a loss of chain mobility in the bulk of the particles was observed under high pressure. Second, it was shown that high pressure applied at low temperature leads to friction effects between the particles which enhances chain mobility in the particle shell through a local melting phenomenon. These experimental conditions favor the healing of particles and high cohesion was then observed in the resulting sintered samples. The level of friction is enhanced when pressure is applied at a low temperature since the powders are still in a glassy state. Finally, the achievement of cohesive grain boundaries was found to be related to the location and conformation of chain ends. Good healing between particles can only occur if a sufficient number of chain ends are available at the surface of the particle shell. We showed that the native powder state plays a significant role. The direct use of as-received powder leads to final material exhibiting good cohesion whereas pretreatments of the native powder are highly detrimental. It should be noted that this processing does not affect the high initial degree of crystallinity because no bulk melting is observed during consolidation by sintering. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47645.     

NMR Profiling of Exhaled Breath Condensate Defines Different Metabolic Phenotypes of Non-Cystic Fibrosis Bronchiectasis

Nuclear-magnetic-resonance (NMR) profiling of exhaled breath condensate (EBC) provides insights into the pathophysiology of bronchiectasis by identifying specific biomarkers. We evaluated whether NMR-based metabolomics discriminates the EBC-derived metabolic phenotypes (“metabotypes”) of 41 patients with non-cystic fibrosis (nCF) bronchiectasis of various etiology [24 subjects with Primary Ciliary Dyskinesia (PCD); 17 patients with bronchiectasis not associated with PCD (nCF/nPCD)], who were compared to 17 healthy subjects (HS). NMR was used for EBC profiling, and Orthogonal Projections to Latent Structures with partial least-squares discriminant analysis (OPLS-DA) was used as a classifier. The results were validated by using the EBC from 17 PCD patients not included in the primary analysis. Different statistical models were built, which compared nCF/nPCD and HS, PCD and HS, all classes (nCF/nPCD-PCD-HS), and, finally, PCD and nCF/nPCD. In the PCD-nCF/nPCD model, four statistically significant metabolites were able to discriminate between the two groups, with only a minor reduction of the quality parameters. In particular, for nCF/nPCD, acetone/acetoin and methanol increased by 21% and 18%, respectively. In PCD patients, ethanol and lactate increased by 25% and 28%, respectively. They are all related to lung inflammation as methanol is found in the exhaled breath of lung cancer patients, acetone/acetoin produce toxic ROS that damage lung tissue in CF, and lactate is observed in acute inflammation. Interestingly, a high concentration of ethanol hampers cilia beating and can be associated with the genetic defect of PCD. Model validation with 17 PCD samples not included in the primary analysis correctly predicted all samples. Our results indicate that NMR of EBC discriminates nCF/nPCD and PCD bronchiectasis patients from HS, and patients with nCF/nPCD from those with PCD. The metabolites responsible for between-group separation identified specific metabotypes, which characterize bronchiectasis of a different etiology.     

Avocado (Persea americana Mill.) by-products and their impact: from bioactive compounds to biomass energy and sorbent material for removing contaminants. A review

Avocado industry produces enormous by-products and represents an important source of raw material in food and non-food applications. This review aims to focus the attention on the valorisation of avocado wastes recycling to produce different materials with important industrial and environmental impacts. In fact, peels and seeds can be reused in food and cosmetic fields due to the presence of bioactive ingredients such as polyphenols; thanks to their antioxidant and antinflammatory activities. In addition, both peels and seeds can be reused in the production of carbonaceous materials with important consequences for environmental pollution in the removal of contaminants from water. Interesting applications of avocado wastes in photocatalysis and biofuel production are also discussed. All the utilisations attest the great potential of recycling avocado by-products, a little known resource.     

Remotely Light‐Powered Soft Fluidic Actuators Based on Plasmonic‐Driven Phase Transitions in Elastic Constraint

Materials capable of actuation through remote stimuli are crucial for untethering soft robotic systems from hardware for powering and control. Fluidic actuation is one of the most applied and versatile actuation strategies in soft robotics. Here, the first macroscale soft fluidic actuator is derived that operates remotely powered and controlled by light through a plasmonically induced phase transition in an elastomeric constraint. A multiphase assembly of a liquid layer of concentrated gold nanoparticles in a silicone or styrene–ethylene–butylene–styrene elastic pocket forms the actuator. Upon laser excitation, the nanoparticles convert light of specific wavelength into heat and initiate a liquid‐to‐gas phase transition. The related pressure increase inflates the elastomers in response to laser wavelength, intensity, direction, and on–off pulses. During laser‐off periods, heating halts and condensation of the gas phase renders the actuation reversible. The versatile multiphase materials actuate—like soft “steam engines”—a variety of soft robotic structures (soft valve, pnue‐net structure, crawling robot, pump) and are capable of operating in different environments (air, water, biological tissue) in a single configuration. Tailored toward the near‐infrared window of biological tissue, the structures actuate also through animal tissue for potential medical soft robotic applications.     

Adoption and Use of Software in Land Use Planning Practice: A Multiple-Country Study

Planning Support Systems (PSS) are computer-based tools that assist professionals in land use planning activities. Although several researchers acknowledge the importance of such tools in planning practice, PSS use is limited due to their poor fit to users’ needs and expectations as well as to their low usability. This article presents a study carried out in three different countries, namely, Australia, Italy, and Switzerland, aiming at investigating in-depth the current situation regarding the adoption of PSS and identifying factors preventing their wider use, devoting particular attention to the quality of such systems from the point of view of their users. The study also aimed at analyzing planners’ expectations in order to identify relevant features that PSS should provide. The main part of the study consisted of 35 interviews with planning experts. A follow-up focus group with six further participants was also performed. The results confirmed some findings of previous studies but also revealed new insights. This article provides suggestions on how to address the emerging issues, as well as pathways for creating software that can be adopted and used with satisfaction in the planning practice.     

Consolidation by spark plasma sintering (SPS) of polyetheretherketone

The present study deals with the consolidation of an ultra‐high performance polymer, the poly(ether ether ketone) (PEEK), for structural applications, using the powder metallurgy (PM) way, and more precisely the Spark Plasma Sintering (SPS) processing. The effects of SPS parameters such as temperature, pressure, and dwell time on density and mechanical properties of PEEK were investigated via a Design of Experiments (DoE). A temperature of 250 °C, a pressure of 40 MPa, and a dwell time of 20 min have been identified as the optimal SPS process parameters. In these conditions, a density of 1.31 g / cm³ was reached and homogeneous mechanical properties in the volume determined by means of compression tests were found with a compressive modulus of 2.75 GPa, a yield strength of 134 MPa, and a maximum compressive strain of 43%. These results are better than those of commercial products obtained by injection molding. The pressure appears to be a significant parameter on PEEK properties and plays positive or negative roles according to the responses of DoE studied. To our knowledge, it is one of the first studies based on the application of the PM techniques for PEEK consolidation showing the possibility to process below its melting point. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44911.     

Disinfection of circulating water systems by ultraviolet light and halogenation

Continuous ultraviolet light (u.v.) and chemical disinfection of circulating water systems were evaluated. Direct comparisons of the biocidal effectiveness of u.v. light vs halogenation were tested with Legionella spp and Pseudomonas aeruginosa because of their association with the acquisition of overt clinical disease from water-containing appliances. Findings indicated that six species of Legionella and P. aeruginosa were killed by a moderate level of u.v. radiation. L. pneumophila and other bacteria in a circulating water system were effectively killed by a biocidal u.v. light. However, free chlorine levels needed to kill Legionella, Pseudomonas, and Flavobacterium within 1 min were found to be greater than 4 mg ml^?1. Data from a long-term field trial with u.v. light treatment of evaporative condenser water showed a significant reduction in numbers of bacteria. Ultraviolet disinfection of hospital hydrotherapy whirlpools confirmed the utility of this mode of disinfection under circumstances where chlorination may not be practical for medical reasons. These findings were confirmed during investigations of halogenated or u.v.-treated public hot tub/whirlpools. The effectiveness of routine chemical disinfection for controlling microbial flora in a cooling tower was also evaluated. The 2 month survey indicated that the numbers of bacteria, including Legionella, were not affected by two biocides that were used. The observations made during this investigation support the conclusion that u.v. light disinfection of water-containing systems may be an appropriate alternative or supplement to chemical biocides.