403 research outputs found

    Frozen mitochondria as rapid water quality bioassay

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    A rapid and relatively low cost bioassay, usable in routine screening water test has been developed modifying the beef heart mitochondria test. In our experiments, mitochondria (FM22) were frozen at 22 °C, instead of 80 °C (FM80), and their applicability and sensitivity was verified. The oxygen consumption was measured by a Clark elec- trode that was interfaced to a PC to collect test analysis data. Blank tests were carried out to verify the oxygen con- sumption linear fitting. Toxicity tests were performed using pure organic and inorganic compounds, such to verify the FM22 sensitivity. A piecewise regression, through an Excelâ Macro, identified the break-point in the oxygen con- sumption and calculated the toxicity. The IC50s of the tested compounds were calculated and ranged from 0.123 to 0.173 mg/l for heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) and from 0.572 to 10.545 mg/l for organics (benzene, DMSO, DDE, endrin, dichloromethane, chlorobenzene, 1,2-dichlorobenzene and 1,3-dichlorobenzene). Water effluent samples were then tested. The FM22 gave different toxic reactions to them. Water samples were characterised for heavy metals. The FM22 bioassay had a higher sensitivity than the FM80 and a high reproducibility in the toxicity test with pure compounds. The FM22 test was a good predictor of toxicity for water samples; the bioassay is easy, low cost and rapid, then usable for routine tests

    Setaria tundra, an emerging filarioid nematode in roe deer (Capreolus capreolus) in northeast Italy.

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    Coincidental with decades of warming (high temperature and humidity) in the sub-Arctic region of Europe, the mosquito-borne filarioid nematode Setaria tundra is now associated with emerging epidemic disease, resulting in morbidity and mortality for reindeer and moose. Similarly, roe deer is also target of this nematode, as documented in Denmark, Germany and Bulgary. In the early 2000s, S. tundra was first described in roe deer in Piedmont (north Italy). Aedes spp. mosquitoes seem to be the most competent vectors for S. tundra and little is known about its pathogenicity in roe deer. After a first report in 2013 of S. tundra in Friuli Venezia Giulia-FVG (northeast Italy) roe deers, during 2014-2016 an investigation was undertaken to evaluate the its presence in road-killed roe deer from the Gorizia province. Currently, parasitological dissections of 17 roe deer were performed. During the necropsy, nematode specimens (1 to 58 per host) were found in the abdominal cavity. Based on their morphology and biometrics, the nematodes recovered were identified as Setaria tundra and preserved in alcohol or cryopreserved for further analysis Moreover, pathological lesions were described, documented and damaged tissue samples were collected for histological evaluation. The prevalence of S. tundra in FVG roe deer population is 47.1%, mean intensity 11 (range 1-58) and mean abundance 5. The adult worms were located free in the abdominal cavity where tracks left by worm migration were also seen. Macroscopical lesions were polysierositis with thickening spleen and liver serosa with fibrinous deposition on surface of the abdominal organs. Whereas, histological lesions were diffuse serositis, granulomatous reactivity with Muller's giant cells and calcifications. In our study in FVG, this the first recognition of S. tundra and the alarming aspect has been that some road killed roe deers showed some significant pathological peritoneal changes

    The pyrolysis and gasification pathways of automotive shredder residue targeting the production of fuels and chemicals

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    Automotive shredder residue (ASR), also referred to as car fluff, is the 15-25% of end-of-life vehicle’s mass remaining after de-pollution, dismantling, shredding of the hulk and removal of metals from the shredded fraction. ASR typically consists of metals, plastics, rubber, textile, wood and glass, and is commonly landfilled. The use of ASR as a fuel in incineration processes is controversial since toxic pollutants can be generated as by-products if operational conditions and gas cleaning systems are not carefully controlled. Thermochemical treatment of ASR consists of advanced technology processes that convert ASR components liable to decomposition under the application of heat into liquids and/or gases and a solid residue containing metals. Within the thermochemical treatment options for ASR, pyrolysis and gasification are generally considered as the emerging technologies. The pyrolysis process uses medium temperatures (400-600°C) and an oxygen-free environment to decompose ASR chemically, thus producing minimum emissions and allowing metals to be recovered. Gasification is operated at higher temperatures (>700-800°C) and typically uses air as a gasification agent, which raises some issues in terms of emissions. Lab and pilot-scale plants fed with ASR have been built using both technologies, also considering a combination of them. The aim of this paper is the identification of the best conversion pathway for the production of transportation fuels, aviation fuels or chemicals (hydrogen, methanol, etc.) from ASR. The intermediate products from gasification and pyrolysis are used as feedstock in secondary processes for the production of the final products. The heterogeneous and complex composition of ASR raises several challenges upon its thermochemical treatment, so that the second step of the conversion process is typically not even addressed. Instead, this further step is fundamental to obtain some valuable products that can directly replace fossil derived fuels or chemicals. The updated picture presented in this work should help identify the main advantages and drawbacks of the pyrolysis and gasification processes when considered part of an overall ASR to fuels or chemicals plant

    INFLUENZA DELLA MODIFICA ALLO STRONZIO E DELLA CONDIZIONE DI SOLIDIFICAZIONE SULLA MICROSTRUTTURA IN LEGHE ALLUMINIO-SILICIO DA FONDERIA

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    L’elevata velocità di solidificazione così come il trattamento di modifica allo stronzio (Sr) svolgono un ruolo fondamentale nella fonderia d’alluminio, intervenendo sulla scala microstrutturale nonché sulla morfologia e distribuzione del silicio all’interno dell’eutettico. In questo studio sono analizzati in maniera sistematica gli effetti della condizione di solidificazione e della modifica allo Sr sul livello di modifica del silicio eutettico in leghe AlSiMgTi da fonderia. Sono state predisposte differenti configurazioni di analisi termica al fine di variare la velocità di raffreddamento; i campioni ottenuti sono quindi stati analizzati metallograficamente. Gli effetti di un trattamento di modifica al sodio (Na) sono stati infine studiati sulle medesime leghe a titolo di confronto. In condizioni di lento raffreddamento, il livello di modifica in lega EN AB-42000 migliora con l’aumentare del contenuto di Sr e raggiunge valori ottimali quando la quantità di quello si situa nell’intervallo di 100-200 ppm. Simili risultati non sono ottenuti in leghe EN AB-43300 e 44000, la cui microstruttura, nonostante un contenuto più elevato di Sr (400-500 ppm), risulta solo parzialmente modificata. La modifica al Na ha mostrato il miglior grado di efficienza per tutte le leghe analizzate in condizioni di lento raffreddamento. La temperatura eutettica nelle leghe ad elevato tenore di silicio, modificate con 400 ppm di Sr, diminuisce significativamente incrementando la velocità di solidificazione, con un miglioramento del livello di modifica. Considerando i risultati ottenuti dall’analisi termica, l’efficacia del trattamento di modifica al Na e allo Sr è stata studiata su alcuni getti di ruote, colati in gravità con leghe EN AB-42000 e 44000

    An in vitro study of the interaction of Sea-Nine with rat lever mitochondria

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    The interactions of the antifouling compound Sea-Ninetwith rat liver mitochondria have been studied. The results indicate that low doses of this compound inhibit adenosine 59-triphosphate (ATP) synthesis. Further investigations indicate that ATP synthesis inhibition should be due to an interaction of Sea-Nine with the succinic dehydrogenase in the mitochondrial respiratory chain

    Frozen mitochondria as rapid water quality bioassay

    Get PDF
    A rapid and relatively low cost bioassay, usable in routine screening water test has been developed modifying the beef heart mitochondria test. In our experiments, mitochondria (FM22) were frozen at 22 °C, instead of 80 °C (FM80), and their applicability and sensitivity was verified. The oxygen consumption was measured by a Clark elec- trode that was interfaced to a PC to collect test analysis data. Blank tests were carried out to verify the oxygen con- sumption linear fitting. Toxicity tests were performed using pure organic and inorganic compounds, such to verify the FM22 sensitivity. A piecewise regression, through an Excelâ Macro, identified the break-point in the oxygen con- sumption and calculated the toxicity. The IC50s of the tested compounds were calculated and ranged from 0.123 to 0.173 mg/l for heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) and from 0.572 to 10.545 mg/l for organics (benzene, DMSO, DDE, endrin, dichloromethane, chlorobenzene, 1,2-dichlorobenzene and 1,3-dichlorobenzene). Water effluent samples were then tested. The FM22 gave different toxic reactions to them. Water samples were characterised for heavy metals. The FM22 bioassay had a higher sensitivity than the FM80 and a high reproducibility in the toxicity test with pure compounds. The FM22 test was a good predictor of toxicity for water samples; the bioassay is easy, low cost and rapid, then usable for routine tests

    Evidence of a hormetic effect in growth inhibition algal test.

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    Elutriation process was applied on sediments of Guanabara Bay (Rio de Janeiro, Brazil), a very polluted coastal ecosystem, in order to determine their potential toxicity. Elutriates were tested using Skeletonema costatum, an eurialin Diatom. Several ratios of elutriate/growth medium (v/v) were assayed (1:10, 1:4, and undiluted) as cultural medium for exponentially growing algae, carrying out a blank control for each replicate. Tests were performed for five days, controlling algal growth by manual cell counting by microscope, in order to verify the status of the organisms every assay’s day. This experimental design was proved able to highlight a particular phenomenon, i.e. hormesis. Regarding some sites in the southern part of the Guanabara Bay growth curves, relative to lower sediment elutriate dilutions, showed, in fact, a so called toxic stimulation typical of hormetic event. On the contrary undiluted elutriates never permitted algal growth. Obtained results could help furthermore to explain the particular eutrophic situation of the water body, in which there is a high superficial eutrophization and absolute life deficiency in the deeper water column

    Examination and evaluation of a coastal environment contamination at a formed shooting area.

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    In the recent past a very beautiful area along the interior coastal environment of Venice lagoon was used as a Clay Pigeon Shooting for a wide period. The sport of Clay Pigeon Shooting involves using a shotgun to shoot at and break a circular flying target made from a fragile material. It is released from a trap positioned in front of, or at the back of, a shooter; then, a typical target flight area characterizes each shooting site, where, in time, pellets (leadshot), shot cartridge, clay pigeon fragments and generic ammunition residues are found. So, in a brackish water contest soil/sediment treatment, waste removal and potential re-use are extremely delicate processes. The first step of our work was investigate if heavy metal (Pb, As and Sb) release and following leaching event occurred. Therefore, soil/sediment profiles in three hot sites of the target flight area has been performed and metal’s total and bioavailable fraction has been investigated. As well, grassy layer coating the sites and organisms living into has been picked, in order to verify a potential uptake and bioaccumulation

    A new procedure for the monitoring of Cationic Detergents in solution

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    The paper describes a new procedure for the selective monitoring of cationic surfactants in solution. The procedure is based on the fact that cationic surfactants are accumulated inside mitochondria by a potential-driven mechanism. Once inside, the surfactant induces the release of the dye Safranine, previously accumulated inside mitochondria. Therefore the monitoring consists of a direct spectrophotometric measure of the rate of release of safranine in the resuspending medium containing the cationic surfactant
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