1,097 research outputs found

    Mapping the content and fates of scarce metals in discarded cars

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    A great variety of current products make use of components or materials (e.g. electronics, steel and aluminium alloys) that utilise increasing amounts of ‘critical’ or scarce metals (SM). For example, design trends for cars point at increasing SM utilisation in order for regulatory, business and consumer requirements on environmental performance, safety, costs, comfort and infotainment to be met. Modern cars now hold SM in substantial amounts, i.e. the circa one billion cars in use worldwide today, constitute a significant near-term secondary SM resource. However, current end-of-life vehicle (ELV) recycling is mainly aimed at isolating hazardous contents, dismantling spare parts and recycling bulk metals. There is thus a clear risk that ELV SM are not functionally recycled and thus lost for further use. Assessments of the opportunities for increased functional recycling require estimates of SM content of discarded cars and individual waste flows in ELV recycling. However, information on both is limited. Data related to cars is sparse, and challenged by the large range and age span of discarded car brands and models. Measurements of SM in waste flows are few and cover a limited range of SM. Consequently, available data does not allow us to quantify with precision the SM contents of discarded cars reaching the ELV recycling system, or map individual metal flows within it. Instead, our approach relies on mapping 25 ELV SM to main types of applications within three newly produced car models using automotive industry data (International Material Data System, IMDS), and letting these models represent the ELV fleet so that the annual input magnitudes of SM to ELV management can be estimated. Subsequently, we employ material flow analysis of ELV waste streams as basis for identifying potential pathways of these main applications, and the extent to which contained metals may reach processes capable of functional recycling. The approach allows us to qualitatively distinguish subsets of systems flows holding groups of SM, and discuss the potential for functional recycling. Using Swedish ELV management as a case, we conclude that only platinum may be functionally recycled in its main application. Cobalt, gold, manganese, molybdenum, palladium, rhodium and silver may be functionally recycled depending on application and pathways taken. For remaining 17 metals, functional recycling is lacking. Consequently, there is considerable risk of losing SM with current ELV procedures. Given differences in the application of metals and identified pathways, strategies for improving recycling and resource security are considered. Moreover, our case illustrates the considerable challenge, posed by the complexity and range of car configurations and the sparsity of information on SM, to closer assess recycling strategies and advance secondary SM resource utilisation

    The Toxicity of Wiped Dust and Airborne Microbes in Individual Classrooms Increase the Risk of Teachers' Work-Related Symptoms : A Cross-Sectional Study

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    Background: The causes and pathophysiological mechanisms of building-related symptoms (BRS) remain open. Objective: We aimed to investigate the association between teachers' individual work-related symptoms and intrinsic in vitro toxicity in classrooms. This is a further analysis of a previously published dataset. Methods: Teachers from 15 Finnish schools in Helsinki responded to the symptom survey. The boar sperm motility inhibition assay, a sensitive indicator of mitochondrial dysfunction, was used to measure the toxicity of wiped dust and cultured microbial fallout samples collected from the teachers' classrooms. Results: 231 teachers whose classroom toxicity data had been collected responded to the questionnaire. Logistic regression analysis adjusted for age, gender, smoking, and atopy showed that classroom dust intrinsic toxicity was statistically significantly associated with the following 12 symptoms reported by teachers (adjusted ORs in parentheses): nose stuffiness (4.1), runny nose (6.9), hoarseness (6.4), globus sensation (9.0), throat mucus (7.6), throat itching (4.4), shortness of breath (12.2), dry cough (4.7), wet eyes (12.7), hypersensitivity to sound (7.9), difficulty falling asleep (7.6), and increased need for sleep (7.7). Toxicity of cultured microbes was found to be associated with nine symptoms (adjusted ORs in parentheses): headache (2.3), nose stuffiness (2.2), nose dryness (2.2), mouth dryness (2.8), hoarseness (2.2), sore throat (2.8), throat mucus (2.3), eye discharge (10.2), and increased need for sleep (3.5). Conclusions: The toxicity of classroom dust and airborne microbes in boar sperm motility inhibition assay significantly increased teachers' risk of work-related respiratory and ocular symptoms. Potential pathophysiological mechanisms of BRS are discussed.Peer reviewe

    Analytic Model for Cross-Layer Dependencies in VDSL2 access networks

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    Recent changes in user employment of Internet based services, new deployment technologies for mobile networks as well as an ongoing realisation of fixed and mobile converged networks e.g. the EU FP7 project COMBO, are significant examples of enablers for increasing demands on DSL links. Investigating cross-layer dependencies between all layers in the OSI reference model becomes increasingly important. In this paper we present an analytical model and experimental results for the relation between impulse noise on a VDSL2 link and the effect this have on the network layer packet loss. We show how the packet loss rate is dependent not only on the disturbance signal level and periodicity but also on the link utilisation

    An atypical Bacillus anthracis infection in a bull-A potential occupational health hazard

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    Bacillus anthracis infecting cattle is usually identified based on the typical symptom: sudden death. Bacillus anthracis causing atypical symptoms may remain undiagnosed and represent a potential occupational health hazard for, that is veterinarians and producers, butchers and tanners. In the year 2004, one case of sudden death in a dairy farm in southern Finland was diagnosed as bovine anthrax. Four years later 2008, an atypical case of anthrax was diagnosed in the same holding. The bull was taken to the Production Animal Hospital of the Faculty of Veterinary Medicine, University of Helsinki because of fever, loss of appetite and a symmetrically swollen scrotal sac. Penicillin treatment cured the fever but not the swollen scrotum. Before the intended therapeutic castration, a punctuate consisting of 10 ml fluid collected into a syringe from the scrotal sac was cultivated on blood agar at 37 degrees C. After 24 hr, an almost pure culture of a completely non-hemolytic Bacillus cereus-like bacteria was obtained. The strain was identified as B. anthracis using Ba-specific primers by the Finnish Food Safety Authority (RUOKAVIRASTO). After the diagnosis, the bull was euthanized and destroyed, the personnel were treated with prophylactic antibiotics and the clinic was disinfected. In this particular case, treatment with water, Virkon S and lime seemed to be effective to eliminate endospores and vegetative cells since no relapses of anthrax have occurred in 10 years. This case is the last reported anthrax case in Finland.Peer reviewe

    Effects of thermal hydrolytic pre-treatment on biogas process efficiency and microbial community structure in industrial- and laboratory-scale digesters

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    This study examined the impact of thermal hydrolysis process (THP) pre-treatment on anaerobic codigestion of wastewater sludge and household waste and assessed whether THP was vital to achieve higher process capacity. Performance data were collected for both industrial- and laboratory-scale digesters and response in microbial community structure was evaluated by Illumina sequencing. Implementation of THP at the industrial-scale plant increased methane yield by 15% and enhanced substrate degradability. Possibility to extend the sludge retention time due to a higher solid content of the substrate, sanitisation of the digestate and improved fertiliser quality of the digestate were other industrial-scale benefits of THP installation. Continuously-fed laboratory-scale digesters were fed THPtreated or untreated substrate at an organic loading rate (OLR) of 5 g volatile solid (VS)/L/day, a feeding rate necessary at the corresponding industrial-scale plant to meet the estimated population increase within the municipality. The results indicated that the plant could have increased the capacity with unimpaired stability independently of THP installation, even though the retention time was significantly shortened during operation with untreated substrate. Microbial community analyses revealed increased contribution of the Clostridia class after THP installation in industrial-scale digesters and positive correlation between Firmicutes:Bacteriodetes and methane yield in all digesters. Differentiated profiles in laboratory-scale digesters indicated that a temperature increase from 37 to 42 degrees C in association with THP installation and altered substrate composition were strong determining factors shaping the microbial community. Overall, these findings can assist industrial-scale plants in choosing management strategies aimed at improving the efficiency of anaerobic digestion processes. (C) 2019 The Authors. Published by Elsevier Ltd

    In Search of Clinical Markers: Indicators of Exposure in Dampness and Mold Hypersensitivity Syndrome (DMHS)

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    Potential markers were sought to diagnose mold hypersensitivity. Indoor air condensed water and human macrophage THP-1 test were applied to evaluate the buildings. Basophil activation tests (BAT) were conducted and mold-specific immunoglobulins (IgE, IgG, IgA, and IgD) were measured in study subjects’ serum and feces. Exposed subjects reported markedly more symptoms from occupational air than controls. Basophils from exposed subjects died/lost activity at 225 times lower concentrations of toxic extracts from the target building than recommended in the common BAT protocol. Fecal IgG and IgD levels against Acrostalagmus luteoalbus and Aspergillus versicolor produced receiver operating curves (ROC) of 0.928 and 0.916, respectively, when plotted against the inflammation marker MRP8/14. Assaying serum immunoglobulin concentrations against the toxic Chaetomium globosum (MTAV35) from another building, a test control, did not differentiate study individuals. However, if liver metabolism produced the same core molecule from other Chaetomium globosum strains, this would explain the increased response in fecal immunoglobulins in the exposed. The altered immunoglobulin values in the samples of exposed when compared to controls revealed the route of mold exposure. The toxicity of indoor air condensed water samples, BAT and serology confirmed the severity of symptoms in the target building’s employees, supporting earlier findings of toxicity in this building

    BRAF immunohistochemistry predicts sentinel lymph node involvement in intermediate thickness melanomas

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    Background Sentinel node biopsy (SNB) is an important step in melanoma staging and prognostication. It is commonly performed for patients with intermediate thickness melanomas, based on clinicopathological features. However, only 20-25% of patients eventually demonstrate nodal involvement. The aim of this study was to evaluate whether tissue biomarkers with links to melanoma biology, together with clinicopathological parameters, could aid in the prediction of sentinel node involvement and improve selection of patients for SNB. In addition, we examined the role of these clinical or biological markers in disease outcome. Methods We collected a case-control cohort of 140 intermediate thickness (Breslow 0,9-4,0mm) melanoma patients with or without SNB involvement matched for age, gender, Breslow thickness and location. From this cohort, we tested the predictive value of common clinicopathological parameters (ulceration, mitotic count and tumor regression) and FMNL-2, ezrin and BRAF V600E immunoreactivity, for sentinel node involvement and survival. We further analyzed the correlations in the superficial spreading melanoma subtype. Results Based on our case control analysis, of the markers, BRAF V600E status (p = 0.010) and mitotic count (p = 0.036) correlated with SNB involvement. SNB status was a strong independent prognosticator for recurrence free survival (RFS p Conclusions These results demonstrate that BRAF immunohistochemistry could serve as a useful addition to a marker panel for selecting intermediate thickness melanoma patients for SNB.Peer reviewe

    Bioreactivity, Guttation and Agents Influencing Surface Tension of Water Emitted by Actively Growing Indoor Mould Isolates

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    The secretion of metabolites in guttation droplets by indoor moulds is not well documented. This study demonstrates the guttation of metabolites by actively growing common indoor moulds. Old and fresh biomasses of indoor isolates of Aspergillus versicolor, Chaetomium globosum, Penicillium expansum, Trichoderma atroviride, T. trixiae, Rhizopus sp. and Stachybotrys sp. were compared. Metabolic activity indicated by viability staining and guttation of liquid droplets detected in young (6 months old) cultures consisting of dehydrated hyphae and dormant conidia. Fresh
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