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Sample records for toxics formation potential

  1. Control of aliphatic halogenated DBP precursors with multiple drinking water treatment processes: Formation potential and integrated toxicity.

    Science.gov (United States)

    Zhang, Yimeng; Chu, Wenhai; Yao, Dechang; Yin, Daqiang

    2017-08-01

    The comprehensive control efficiency for the formation potentials (FPs) of a range of regulated and unregulated halogenated disinfection by-products (DBPs) (including carbonaceous DBPs (C-DBPs), nitrogenous DBPs (N-DBPs), and iodinated DBPs (I-DBPs)) with the multiple drinking water treatment processes, including pre-ozonation, conventional treatment (coagulation-sedimentation, pre-sand filtration), ozone-biological activated carbon (O 3 -BAC) advanced treatment, and post-sand filtration, was investigated. The potential toxic risks of DBPs by combing their FPs and toxicity values were also evaluated. The results showed that the multiple drinking water treatment processes had superior performance in removing organic/inorganic precursors and reducing the formation of a range of halogenated DBPs. Therein, ozonation significantly removed bromide and iodide, and thus reduced the formation of brominated and iodinated DBPs. The removal of organic carbon and nitrogen precursors by the conventional treatment processes was substantially improved by O 3 -BAC advanced treatment, and thus prevented the formation of chlorinated C-DBPs and N-DBPs. However, BAC filtration leads to the increased formation of brominated C-DBPs and N-DBPs due to the increase of bromide/DOC and bromide/DON. After the whole multiple treatment processes, the rank order for integrated toxic risk values caused by these halogenated DBPs was haloacetonitriles (HANs)≫haloacetamides (HAMs)>haloacetic acids (HAAs)>trihalomethanes (THMs)>halonitromethanes (HNMs)≫I-DBPs (I-HAMs and I-THMs). I-DBPs failed to cause high integrated toxic risk because of their very low FPs. The significant higher integrated toxic risk value caused by HANs than other halogenated DBPs cannot be ignored. Copyright © 2017. Published by Elsevier B.V.

  2. In vitro screening of 50 highly prescribed drugs for thiol adduct formation--comparison of potential for drug-induced toxicity and extent of adduct formation.

    Science.gov (United States)

    Gan, Jinping; Ruan, Qian; He, Bing; Zhu, Mingshe; Shyu, Wen C; Humphreys, W Griffith

    2009-04-01

    Reactive metabolite formation has been associated with drug-induced liver, skin, and hematopoietic toxicity of many drugs that has resulted in serious clinical toxicity, leading to clinical development failure, black box warnings, or, in some cases, withdrawal from the market. In vitro and in vivo screening for reactive metabolite formation has been proposed and widely adopted in the pharmaceutical industry with the aim of minimizing the property and thus the risk of drug-induced toxicity (DIT). One of the most common screening methods is in vitro thiol trapping of reactive metabolites. Although it is well-documented that many hepatotoxins form thiol adducts, there is no literature describing the adduct formation potential of safer drugs that are widely used. The objective of this study was to quantitatively assess the thiol adduct formation potential of 50 drugs (10 associated with DIT and 40 not associated) and document apparent differences in adduct formation between toxic and safer drugs. Dansyl glutathione was used as a trapping agent to aid the quantitation of adducts following in vitro incubation of drugs with human liver microsomes in the presence and absence of NADPH. Metabolic turnover of these drugs was also monitored by LC/UV. Overall, 15 out of the 50 drugs screened formed detectable levels of thiol adducts. There were general trends toward more positive findings in the DIT group vs the non-DIT group. These trends became more marked when the relative amount of thiol adducts was taken into account and improved further when dose and total daily reactive metabolite burdens were considered. In conclusion, there appears to be a general trend between the extent of thiol adduct formation and the potential for DIT, which would support the preclinical measurement and minimization of the property through screening of thiol adduct formation as part of an overall discovery optimization paradigm.

  3. Toxic potential of palytoxin.

    Science.gov (United States)

    Patocka, Jiří; Gupta, Ramesh C; Wu, Qing-hua; Kuca, Kamil

    2015-10-01

    This review briefly describes the origin, chemistry, molecular mechanism of action, pharmacology, toxicology, and ecotoxicology of palytoxin and its analogues. Palytoxin and its analogues are produced by marine dinoflagellates. Palytoxin is also produced by Zoanthids (i.e. Palythoa), and Cyanobacteria (Trichodesmium). Palytoxin is a very large, non-proteinaceous molecule with a complex chemical structure having both lipophilic and hydrophilic moieties. Palytoxin is one of the most potent marine toxins with an LD50 of 150 ng/kg body weight in mice exposed intravenously. Pharmacological and electrophysiological studies have demonstrated that palytoxin acts as a hemolysin and alters the function of excitable cells through multiple mechanisms of action. Palytoxin selectively binds to Na(+)/K(+)-ATPase with a Kd of 20 pM and transforms the pump into a channel permeable to monovalent cations with a single-channel conductance of 10 pS. This mechanism of action could have multiple effects on cells. Evaluation of palytoxin toxicity using various animal models revealed that palytoxin is an extremely potent neurotoxin following an intravenous, intraperitoneal, intramuscular, subcutaneous or intratracheal route of exposure. Palytoxin also causes non-lethal, yet serious toxic effects following dermal or ocular exposure. Most incidents of palytoxin poisoning have manifested after oral intake of contaminated seafood. Poisonings in humans have also been noted after inhalation, cutaneous/systemic exposures with direct contact of aerosolized seawater during Ostreopsis blooms and/or through maintaining aquaria containing Cnidarian zoanthids. Palytoxin has a strong potential for toxicity in humans and animals, and currently this toxin is of great concern worldwide.

  4. Removal characteristics of DON in pharmaceutical wastewater and its influence on the N-nitrosodimethylamine formation potential and acute toxicity of DOM.

    Science.gov (United States)

    Hu, Haidong; Jiang, Cong; Ma, Haijun; Ding, Lili; Geng, Jinju; Xu, Ke; Huang, Hui; Ren, Hongqiang

    2017-02-01

    Previous research has focused on dissolved organic carbon (DOC) as a surrogate for dissolved organic matter (DOM) in pharmaceutical wastewater. Dissolved organic nitrogen (DON) as a part of DOM has received little attention. This study investigated the removal characteristics of DON and its influence on the N-nitrosodimethylamine formation potential (NDMA FP) and acute toxicity of DOM in a full-scale hydrolysis/acidification + anaerobic/anoxic/aerobic + moving bed biofilm reactor (MBBR) process treating pharmaceutical wastewater. Results showed that maximum removal of DON (68 ± 12%) was present in the anaerobic process. The removal of DON by anoxic and aerobic processes was negligible as a result of the production of new N-containing compounds that are characteristic of proteins/amino sugars and lipids. DON concentration decreased significantly in the MBBR process (p toxicity was significantly associated with the 3 kDa wastewater was recommended, as it provides important information for DOM removal characteristics. Copyright © 2016. Published by Elsevier Ltd.

  5. Toxicity and pollution potential of thallium.

    Science.gov (United States)

    Zitko, V

    1975-07-01

    Toxicity and pollution potential of thallium are reviewed. Thallium is slightly more acutely toxic to mammals than mercury, and as acutely toxic as copper to fish. Its present industrial uses are too limited to generate pollution, but thallium, discharged in wastes from mines, ore-processing, and coal-burning plants, is contaminating the environment.

  6. Screening of toxic potential of graphene family nanomaterials using and alternative toxicity testing systems

    Directory of Open Access Journals (Sweden)

    Nivedita Chatterjee

    2015-07-01

    Full Text Available Objectives The widely promising applications of graphene nanomaterials raise considerable concerns regarding their environmental and human health risk assessment. The aim of the current study was to evaluate the toxicity profiling of graphene family nananomaterials (GFNs in alternative in vitro and in vivo toxicity testing models. Methods The GFNs used in this study are graphene nanoplatelets ([GNPs]–pristine, carboxylate [COOH] and amide [NH2] and graphene oxides (single layer [SLGO] and few layers [FLGO]. The human bronchial epithelial cells (Beas2B cells as in vitro system and the nematode Caenorhabditis elegans as in vivo system were used to profile the toxicity response of GFNs. Cytotoxicity assays, colony formation assay for cellular toxicity and reproduction potentiality in C. elegans were used as end points to evaluate the GFNs’ toxicity. Results In general, GNPs exhibited higher toxicity than GOs in Beas2B cells, and among the GNPs the order of toxicity was pristine>NH2>COOH. Although the order of toxicity of the GNPs was maintained in C. elegans reproductive toxicity, but GOs were found to be more toxic in the worms than GNPs. In both systems, SLGO exhibited profoundly greater dose dependency than FLGO. The possible reason of their differential toxicity lay in their distinctive physicochemical characteristics and agglomeration behavior in the exposure media. Conclusions The present study revealed that the toxicity of GFNs is dependent on the graphene nanomaterial’s physical forms, surface functionalizations, number of layers, dose, time of exposure and obviously, on the alternative model systems used for toxicity assessment.

  7. Toxic Potential of Carcinogenic Polycyclic Aromatic Hydrocarbons ...

    African Journals Online (AJOL)

    DR. GODSON

    Toxic Potential of Carcinogenic Polycyclic Aromatic Hydrocarbons (cPAHs) and Heavy. Metal in Crude Oil from Gokana Area, Rivers ... Exploration and production activities of petroleum in the Niger delta, Nigeria has led to the accidental ..... Chemical and bio-geophysical impact of four- dimensional seismic exploration.

  8. Potential enzyme toxicity of oxytetracycline to catalase

    International Nuclear Information System (INIS)

    Chi Zhenxing; Liu Rutao; Zhang Hao

    2010-01-01

    Oxytetracycline (OTC) is a kind of widely used veterinary drugs. The residue of OTC in the environment is potentially harmful. In the present work, the non-covalent toxic interaction of OTC with catalase was investigated by the fluorescence spectroscopy, UV-vis absorption and circular dichroism (CD) spectroscopy at physiological pH 7.4. OTC can interact with catalase to form a complex mainly by van der Waals' interactions and hydrogen bonds with one binding site. The association constants K were determined to be K 293K = 7.09 x 10 4 L mol -1 and K 311K = 3.31 x 10 4 L mol -1 . The thermodynamic parameters (ΔH o , ΔG o and ΔS o ) of the interaction were calculated. Based on the Foerster theory of non-radiative energy transfer, the distance between bound OTC and the tryptophan residues of catalase was determined to be 6.48 nm. The binding of OTC can result in change of the micro-environment of the tryptophan residues and the secondary structure of catalase. The activity of catalase was also inhibited for the bound OTC. This work establishes a new strategy to probe the enzyme toxicity of veterinary drug residues and is helpful for clarifying the molecular toxic mechanism of OTC in vivo. The established strategy can be used to investigate the potential enzyme toxicity of other small organic pollutants and drugs.

  9. Big data in chemical toxicity research: the use of high-throughput screening assays to identify potential toxicants.

    Science.gov (United States)

    Zhu, Hao; Zhang, Jun; Kim, Marlene T; Boison, Abena; Sedykh, Alexander; Moran, Kimberlee

    2014-10-20

    High-throughput screening (HTS) assays that measure the in vitro toxicity of environmental compounds have been widely applied as an alternative to in vivo animal tests of chemical toxicity. Current HTS studies provide the community with rich toxicology information that has the potential to be integrated into toxicity research. The available in vitro toxicity data is updated daily in structured formats (e.g., deposited into PubChem and other data-sharing web portals) or in an unstructured way (papers, laboratory reports, toxicity Web site updates, etc.). The information derived from the current toxicity data is so large and complex that it becomes difficult to process using available database management tools or traditional data processing applications. For this reason, it is necessary to develop a big data approach when conducting modern chemical toxicity research. In vitro data for a compound, obtained from meaningful bioassays, can be viewed as a response profile that gives detailed information about the compound's ability to affect relevant biological proteins/receptors. This information is critical for the evaluation of complex bioactivities (e.g., animal toxicities) and grows rapidly as big data in toxicology communities. This review focuses mainly on the existing structured in vitro data (e.g., PubChem data sets) as response profiles for compounds of environmental interest (e.g., potential human/animal toxicants). Potential modeling and mining tools to use the current big data pool in chemical toxicity research are also described.

  10. Chloramination of wastewater effluent: Toxicity and formation of disinfection byproducts.

    Science.gov (United States)

    Le Roux, Julien; Plewa, Michael J; Wagner, Elizabeth D; Nihemaiti, Maolida; Dad, Azra; Croué, Jean-Philippe

    2017-08-01

    The reclamation and disinfection of waters impacted by human activities (e.g., wastewater effluent discharges) are of growing interest for various applications but has been associated with the formation of toxic nitrogenous disinfection byproducts (N-DBPs). Monochloramine used as an alternative disinfectant to chlorine can be an additional source of nitrogen in the formation of N-DBPs. Individual toxicity assays have been performed on many DBPs, but few studies have been conducted with complex mixtures such as wastewater effluents. In this work, we compared the cytotoxicity and genotoxicity of wastewater effluent organic matter (EfOM) before and after chloramination. The toxicity of chloraminated EfOM was significantly higher than the toxicity of raw EfOM, and the more hydrophobic fraction (HPO) isolated on XAD-8 resin was more toxic than the fraction isolated on XAD-4 resin. More DBPs were also isolated on the XAD-8 resin. N-DBPs (i.e., haloacetonitriles or haloacetamides) were responsible for the majority of the cytotoxicity estimated from DBP concentrations measured in the XAD-8 and XAD-4 fractions (99.4% and 78.5%, respectively). Measured DBPs accounted for minor proportions of total brominated and chlorinated products, which means that many unknown halogenated compounds were formed and can be responsible for a significant part of the toxicity. Other non-halogenated byproducts (e.g., nitrosamines) may contribute to the toxicity of chloraminated effluents as well. Copyright © 2017. Published by Elsevier B.V.

  11. Toxic Potential of Carcinogenic Polycyclic Aromatic Hydrocarbons ...

    African Journals Online (AJOL)

    Considerable caution should be applied in exploration, exposure and distribution of the crude oil through protected and well maintained pipelines to avoid the possible release of PAHs as well as nickel and chromium toxicity to soil, water and inhabitants of Gokana area. Keywords: carcinogenicity, toxicity, crude oil, heavy ...

  12. Pesticide Toxicity Index: a tool for assessing potential toxicity of pesticide mixtures to freshwater aquatic organisms

    Science.gov (United States)

    Nowell, Lisa H.; Norman, Julia E.; Moran, Patrick W.; Martin, Jeffrey D.; Stone, Wesley W.

    2014-01-01

    Pesticide mixtures are common in streams with agricultural or urban influence in the watershed. The Pesticide Toxicity Index (PTI) is a screening tool to assess potential aquatic toxicity of complex pesticide mixtures by combining measures of pesticide exposure and acute toxicity in an additive toxic-unit model. The PTI is determined separately for fish, cladocerans, and benthic invertebrates. This study expands the number of pesticides and degradates included in previous editions of the PTI from 124 to 492 pesticides and degradates, and includes two types of PTI for use in different applications, depending on study objectives. The Median-PTI was calculated from median toxicity values for individual pesticides, so is robust to outliers and is appropriate for comparing relative potential toxicity among samples, sites, or pesticides. The Sensitive-PTI uses the 5th percentile of available toxicity values, so is a more sensitive screening-level indicator of potential toxicity. PTI predictions of toxicity in environmental samples were tested using data aggregated from published field studies that measured pesticide concentrations and toxicity to Ceriodaphnia dubia in ambient stream water. C. dubia survival was reduced to ≤ 50% of controls in 44% of samples with Median-PTI values of 0.1–1, and to 0% in 96% of samples with Median-PTI values > 1. The PTI is a relative, but quantitative, indicator of potential toxicity that can be used to evaluate relationships between pesticide exposure and biological condition.

  13. Ambipolar potential formation in TMX

    International Nuclear Information System (INIS)

    Correll, D.L.; Allen, S.L.; Casper, T.A.

    1981-01-01

    TMX experimental data on ambipolar potential control and on the accompanying electrostatic confinement are reported. New results on the radial dependence of the central-cell confining potential are given. Radial and axial particle losses as well as scaling of the central-cell axial confinement are discussed

  14. Toxic Byproduct Formation during Electrochemical Treatment of Latrine Wastewater

    Science.gov (United States)

    2017-01-01

    Electrochemical systems are an attractive option for onsite latrine wastewater treatment due to their high efficiency and small footprint. While concerns remain over formation of toxic byproducts during treatment, rigorous studies examining byproduct formation are lacking. Experiments treating authentic latrine wastewater over variable treatment times, current densities, chloride concentrations, and anode materials were conducted to characterize byproducts and identify conditions that minimize their formation. Production of inorganic byproducts (chlorate and perchlorate) and indicator organic byproducts (haloacetic acids and trihalomethanes) during electrolysis dramatically exceeded recommendations for drinking water after one treatment cycle (∼10–30 000 times), raising concerns for contamination of downstream water supplies. Stopping the reaction after ammonium was removed (i.e., the chlorination breakpoint) was a promising method to minimize byproduct formation without compromising disinfection and nutrient removal. Though treatment was accelerated at increased chloride concentrations and current densities, byproduct concentrations remained similar near the breakpoint. On TiO2/IrO2 anodes, haloacetic acids (up to ∼50 μM) and chlorate (up to ∼2 μM) were of most concern. Although boron-doped diamond anodes mineralized haloacetic acids after formation, high production rates of chlorate and perchlorate (up to ∼4 and 25 μM) made them inferior to TiO2/IrO2 anodes in terms of toxic byproduct formation. Organic byproduct formation was similar during chemical chlorination and electrolysis of wastewater, suggesting that organic byproducts are formed by similar pathways in both cases (i.e., reactions with chloramines and free chlorine). PMID:28538093

  15. Klebsiella pneumoniae KE-1 degrades endosulfan without formation of the toxic metabolite, endosulfan sulfate.

    Science.gov (United States)

    Kwon, Gi-Seok; Kim, Jang-Eok; Kim, Taek-Kyum; Sohn, Ho-Yong; Koh, Sung-Cheol; Shin, Kee-Sun; Kim, Dong-Geol

    2002-10-08

    For bioremediation of toxic endosulfan, endosulfan degradation bacteria, which do not form toxic endosulfan sulfate, were isolated from various soil samples using endosulfan as sole carbon and energy source. Among the 40 isolated bacteria, strain KE-1, which was identified as Klebsiella pneumoniae by physiological and 16S rDNA sequence analysis, showed superior endosulfan degradation activity. Analysis of culture pH, growth, free sulfate and endosulfan and its metabolites demonstrated that KE-1 biologically degrades 8.72 microg endosulfan ml(-1) day(-1) when incubated with 93.9 microg ml(-1) endosulfan for 10 days without formation of toxic endosulfan sulfate. Our results suggest that K. pneumoniae KE-1 degraded endosulfan by a non-oxidative pathway and that strain KE-1 has potential as a biocatalyst for endosulfan bioremediation.

  16. Can Dietary Polyphenols Prevent the Formation of Toxic Compounds from Maillard Reaction?

    Science.gov (United States)

    Del Turco, Serena; Basta, Giuseppina

    2016-01-01

    Polyphenols are functional compounds in edible vegetable and food such as tea, coffee and red wine and increasing evidence demonstrates a positive link between consumption of polyphenol-rich foods and disease prevention. In this review we have focused on the current knowledge of the potential anti-glycation effects of polyphenols, particularly in regard to their influence on Maillard reaction, a non-enzymatic reaction between amino acids and reducing sugars that contributes to the production of toxic compounds, mainly reactive carbonyl species, advanced glycation end-products (AGEs) and other toxicants. The Maillard reaction occurs in the human body during hyperglycemic condition, but it is well known as browning reaction in thermally processed foods and it is responsible for flavor and toxicant formation. Dietary polyphenols can have anti-glycation effects and actively participate in Maillard reaction, mitigating the AGE formation and the heat-induced production of toxic compounds. In a time in which the role of a healthy diet in the prevention of chronic diseases is welcome and the borderline between food and medicine is becoming very thin, an improved mechanistic knowledge of how polyphenols can function to reduce harmful and unhealthy substances is mandatory.

  17. Assessing predictive uncertainty in comparative toxicity potentials of triazoles.

    Science.gov (United States)

    Golsteijn, Laura; Iqbal, M Sarfraz; Cassani, Stefano; Hendriks, Harrie W M; Kovarich, Simona; Papa, Ester; Rorije, Emiel; Sahlin, Ullrika; Huijbregts, Mark A J

    2014-02-01

    Comparative toxicity potentials (CTPs) quantify the potential ecotoxicological impacts of chemicals per unit of emission. They are the product of a substance's environmental fate, exposure, and hazardous concentration. When empirical data are lacking, substance properties can be predicted. The goal of the present study was to assess the influence of predictive uncertainty in substance property predictions on the CTPs of triazoles. Physicochemical and toxic properties were predicted with quantitative structure-activity relationships (QSARs), and uncertainty in the predictions was quantified with use of the data underlying the QSARs. Degradation half-lives were based on a probability distribution representing experimental half-lives of triazoles. Uncertainty related to the species' sample size that was present in the prediction of the hazardous aquatic concentration was also included. All parameter uncertainties were treated as probability distributions, and propagated by Monte Carlo simulations. The 90% confidence interval of the CTPs typically spanned nearly 4 orders of magnitude. The CTP uncertainty was mainly determined by uncertainty in soil sorption and soil degradation rates, together with the small number of species sampled. In contrast, uncertainty in species-specific toxicity predictions contributed relatively little. The findings imply that the reliability of CTP predictions for the chemicals studied can be improved particularly by including experimental data for soil sorption and soil degradation, and by developing toxicity QSARs for more species. © 2013 SETAC.

  18. formation of toxic nitrosamine as a complication of prostatic ...

    African Journals Online (AJOL)

    Dr Olaleye

    oxytetracycline and amino antipyrine, to form various types of nitroso compounds. The possibility of the interaction, and its attendant toxicity to the liver as a complication in some established cases of urinary tract infection [UTI], was the main focus of the study. This toxicity and its specificity for the liver, as a consequence of ...

  19. Formation of potential antigens from radiographic contrast media

    International Nuclear Information System (INIS)

    Nilsson, R.; Ehrenberg, L.; Fedorcsak, I.

    1987-01-01

    The use of radiographic contrast media is occasionally accompanied by more or less serious adverse effects, evidently of complex etiology, following intravascular administration. Some of these reactions are suspected of having an allergic basis. The in vitro and in vivo formation of iodinated serum proteins following gamma irradiation in the presence of two commonly used radiographic contrast media is demonstrated. Non-toxic concentrations of ascorbate present during the irradiation is shown to prevent the formation of such iodo-proteins in vitro as well as in vivo. The amounts of potentially antigenic iodoprotein formed during radiographic procedures will certainly be very small, but this quantity may be sufficient to elicit a hypersensitivity reaction in cases when an individual has been previously sensitized to immunologically similar iodo-proteins, a mechanism that could account for certain rare and unpredictable reations. The radiation induced formation of iodo-proteins may also serve as a model for the formation of iodine containing antigens mediated by a free radical mechanism, i.e. in the metabolism of iodinated compounds like erythrosine, a widely used colouring agent for certain foods. (orig.)

  20. In vitro examination of oral tissue conditioners potential toxicity

    Directory of Open Access Journals (Sweden)

    Krunić Nebojša

    2011-01-01

    Full Text Available The oral tissue conditioners are applied temporarily to the gingival surface of a denture for the purpose of reconditioning the abused denture supporting tissues, allowing them to return to a normal, healthy state. According to chemical composition they can be classified into methacrylic and silicon conditioners. The objective of this research was to examine the potential toxicity of one, seven and thirty day extracts of different concentrations. Different effective concentrations (5, 12.5, 25 and 50% of two silicone and four methacrylic conditioners extracts were used after extraction period of one, seven and thirty days. Amount of toxic substances and dynamics of their release were monitored by high-pressure liquid chromatography (HPLC. HPLC analysis could not be applied to the silicone conditioners because they consist of polymeric and inorganic 19 substances. Evaluation of cell proliferation, as cytotoxic parameters, was done by Mosmann’s MTT assay based on reduction of yellow tetrazole (3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide - MTT to purple formazan by mitochondrial succinate dehydrogenase of metabolic active cells. With increasing of extraction period, the amount of released potential toxic substances increased. The cytotoxicity of tested materials significantly increased with extract concentration increase and duration of extraction period. To improve the biological characteristics of mobile dentures relined by soft materials, soaking in water the day before insertion into patient’s mouth was recommended. Silicone conditioners showed less cytotoxicity compared to the methacrylic conditioners, so they are more appropriate for daily dental practice.

  1. Tropospheric gas at potentially toxic levels in air

    Science.gov (United States)

    Bhattacharya, Atreyee

    2012-08-01

    Forest fires and emission of air pollutants, such as fumes from vehicles running on diesel and slow burning of coal and charcoal, release isocyanic acid in the troposphere. In 2011, scientists first detected isocyanic acid in the ambient atmosphere at levels toxic to human populations; at concentrations exceeding 1 part per billion by volume (ppbv), human beings could experience tissue decay when exposed to the toxin. For the first time, using a chemical transport model designed to estimate the distribution and budget of isocyanic acid in the troposphere, Young et al. showed that in several parts of the world, local emissions may increase the concentration of isocyanic acid in the ambient atmosphere, thereby exposing large populations to potentially toxic levels of the acid.

  2. Acrylamide: inhibition of formation in processed food and mitigation of toxicity in cells, animals, and humans.

    Science.gov (United States)

    Friedman, Mendel

    2015-06-01

    Potentially toxic acrylamide is largely derived from the heat-inducing reactions between the amino group of the amino acid asparagine and carbonyl groups of glucose and fructose in plant-derived foods including cereals, coffees, almonds, olives, potatoes, and sweet potatoes. This review surveys and consolidates the following dietary aspects of acrylamide: distribution in food, exposure and consumption by diverse populations, reduction of the content in different food categories, and mitigation of adverse in vivo effects. Methods to reduce acrylamide levels include selecting commercial food with a low acrylamide content, selecting cereal and potato varieties with low levels of asparagine and reducing sugars, selecting processing conditions that minimize acrylamide formation, adding food-compatible compounds and plant extracts to food formulations before processing that inhibit acrylamide formation during processing of cereal products, coffees, teas, olives, almonds, and potato products, and reducing multiorgan toxicity (antifertility, carcinogenicity, neurotoxicity, teratogenicity). The herein described observations and recommendations are of scientific interest for food chemistry, pharmacology, and toxicology, but also have the potential to benefit nutrition, food safety, and human health.

  3. NODC Standard Format Marine Toxic Substances and Pollutants (F144) chemical identification codes (NODC Accession 9200273)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival information package contains a listing of codes and chemical names that were used in NODC Standard Format Marine Toxic Substances and Pollutants (F144)...

  4. Potential toxicity of superparamagnetic iron oxide nanoparticles (SPION

    Directory of Open Access Journals (Sweden)

    Neenu Singh

    2010-09-01

    Full Text Available Superparamagnetic iron oxide nanoparticles (SPION are being widely used for various biomedical applications, for example, magnetic resonance imaging, targeted delivery of drugs or genes, and in hyperthermia. Although, the potential benefits of SPION are considerable, there is a distinct need to identify any potential cellular damage associated with these nanoparticles. Besides focussing on cytotoxicity, the most commonly used determinant of toxicity as a result of exposure to SPION, this review also mentions the importance of studying the subtle cellular alterations in the form of DNA damage and oxidative stress. We review current studies and discuss how SPION, with or without different surface coating, may cause cellular perturbations including modulation of actin cytoskeleton, alteration in gene expression profiles, disturbance in iron homeostasis and altered cellular responses such as activation of signalling pathways and impairment of cell cycle regulation. The importance of protein–SPION interaction and various safety considerations relating to SPION exposure are also addressed.

  5. Potential testicular toxicity of sodium nitrate in adult rats.

    Science.gov (United States)

    Aly, Hamdy A A; Mansour, Ahmed M; Abo-Salem, Osama M; Abd-Ellah, Hala F; Abdel-Naim, Ashraf B

    2010-02-01

    Nitrate is a common contaminant in groundwater aquifers. Current study aimed at evaluating the potential testicular toxicity of sodium nitrate in rats. Sodium nitrate was given orally to rats at doses of 50, 100 or 200 mg/kg/day for 60 consecutive days. Sperm count and motility, daily sperm production and testis weight were significantly decreased specially at high doses. Testicular activity of lactate dehydrogenase-X, glucose-6-phosphate dehydrogenase, and acid phosphatase were inhibited in a dose-related manner. Lipid peroxides and hydrogen peroxide production were significantly increased in all treated animals. This was accompanied by inhibition of testicular activities of superoxide dismutase and glutathione peroxidase. Fifty mg/kg of sodium nitrate did not significantly alter catalase or glutathione reductase activity. Glutathione was significantly decreased by sodium nitrate in a dose-related manner. The decrease in sperm count and motility and daily sperm production was confirmed by histopathological studies which indicated chromatolysis, pyknosis and necrosis in spermatocytes. In conclusion, subchronic exposure of rats to sodium nitrate results in testicular toxicity as evidenced by decreased sperm count and motility, daily sperm production and testis weight, inhibited activity of enzyme markers of spermatogenesis and induction of histopathological changes. These effects are attributed, at least partly, to testicular oxidative stress. Copyright 2009. Published by Elsevier Ltd.

  6. Investigation on potential enzyme toxicity of clenbuterol to trypsin

    Science.gov (United States)

    Chai, Jun; Xu, Qifei; Dai, Jinping; Liu, Rutao

    2013-03-01

    Clenbuterol (CLB) is a kind of β2-adrenergic agonists which was illegally used as feed additives nowadays. The toxic interaction of CLB with trypsin, an important digestive enzyme, was studied in vitro using multi-spectroscopic methods and molecular modeling methods. CLB was proved to bind with trypsin in S1 pocket, forming a complex driven by the dominant force of H-bond. The binding constant was calculated to be 1.79887 × 105 L mol-1 at 289 K and 0.32584 × 105 L mol-1 at 310 K, respectively. The skeleton of trypsin became loosened and unfolded with the amino residues microenvironment changed. The secondary and tertiary structure of trypsin also varied. Molecular modeling studies illustrated specific display of the binding information and explained most of the experiment phenomena. The binding site of CLB induced the fluorescence quenching as well as inhibition of enzyme activity of trypsin. The study confirmed that CLB had potential toxicity on both the structure and function of trypsin and the effects enhanced with the increasing concentration of CLB.

  7. A question about the potential cardiac toxicity of escitalopram.

    Science.gov (United States)

    Howland, Robert H

    2012-04-01

    Previous reviews have focused on the potential cardiac toxicity of the racemic drug citalopram (Celexa(®)). Evaluating the safety of escitalopram (Lexapro(®)) is an important issue to consider, since it is the S-enantiomer of citalopram. Escitalopram has a small effect on the QTc interval. A prolonged QTc was seen in 2% to 14% of escitalopram overdose cases, without serious cardiac sequelae. The QTc prolongation effect of citalopram in beagle dogs has been attributed to the minor metabolite racemic didemethylcitalopram (DDCT). Whether the escitalopram minor metabolite S-DDCT has this effect is not known. Concentrations of S-DDCT are lower than DDCT, but for a broad range of doses of escitalopram and citalopram, the S-DDCT and DDCT concentrations are well below the QTc prolonging concentrations reported in dogs. There is no strong evidence from human and animal studies that the cardiac safety of escitalopram is significantly superior to that of citalopram. Copyright 2012, SLACK Incorporated.

  8. Neurosteroids for the potential protection of humans against organophosphate toxicity.

    Science.gov (United States)

    Reddy, Doodipala Samba

    2016-08-01

    This article describes the therapeutic potential of neurosteroids as anticonvulsant antidotes for chemical intoxication caused by organophosphate pesticides and nerve agents or gases like sarin and soman. Toxic manifestations following nerve agent exposure, as evident in chemical attacks in Japan and Syria, include hypersecretion, respiratory distress, tremors, convulsions leading to status epilepticus (SE), and death. Benzodiazepines, such as diazepam, are the current anticonvulsants of choice for controlling nerve agent-induced life-threatening seizures, SE, and brain injury. Benzodiazepines can control acute seizures when given early, but they are less effective for delayed treatment of SE, which is characterized by rapid desensitization of synaptic GABA A receptors, benzodiazepine resistance, and brain injury. Neurosteroid-sensitive extrasynaptic GABA A receptors, however, remain unaffected by such events. Thus, anticonvulsant neurosteroids may produce more effective protection than benzodiazepines against a broad spectrum of chemical agents, even when given late after nerve agent exposure. © 2016 New York Academy of Sciences.

  9. Toxicity formation and distribution in activated sludge during treatment of N,N-dimethylformamide (DMF) wastewater.

    Science.gov (United States)

    Yang, Na; Chen, Xiurong; Lin, Fengkai; Ding, Yi; Zhao, Jianguo; Chen, Shanjia

    2014-01-15

    The organic toxicity of sludge in land applications is a critical issue; however, minimal attention has been given to the mechanism of toxicity formation during high-strength wastewater treatment. To investigate the relevant factors that contribute to sludge toxicity, synthetic wastewater with N,N-dimethylformamide (DMF) was treated in a sequential aerobic activated sludge reactor. The acute toxicity of sludge, which is characterised by the inhibition rate of luminous bacteria T3, is the focus of this study. Using an operational time of 28 days and a hydraulic retention time of 12h, the study demonstrated a positive relationship between the acute toxicity of sludge and the influent DMF concentration; the toxicity centralised in the intracellular and inner sections of extracellular polymeric substances (EPS) in sludge flocs. Due to increased concentrations of DMF, which ranged from 40 to 200mgL(-1), the sludge toxicity increased from 25 to 45%. The organic toxicity in sludge flocs was primarily contributed by the biodegradation of DMF rather than adsorption of DMF. Additional investigation revealed a significant correlation between the properties of the bacterial community and sludge toxicity. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Oxidation of iopamidol with ferrate (Fe(VI)): Kinetics and formation of toxic iodinated disinfection by-products.

    Science.gov (United States)

    Dong, Huiyu; Qiang, Zhimin; Liu, Shaogang; Li, Jin; Yu, Jianwei; Qu, Jiuhui

    2018-03-01

    Presence of iodinated X-ray contrast media (ICMs) in source water is of high concern, because of their potential to form highly toxic iodinated disinfection by-products (I-DBPs). This study investigated kinetics, mechanisms and products for oxidation of one ICMs, iopamidol (IPM) by ferrate (Fe(VI)). The obtained apparent second-order rate constants for oxidation of IPM by Fe(VI) ranged from 0.7 M -1  s -1 to 74.6 M -1  s -1  at pH 6.0-10.0, which were highly dependent on pH. It was found that the oxidation of IPM by Fe(VI) led to the formation of highly toxic I-DBPs. Iodoform (IF), iodoacetic acid and triiodoacetic acid formations were observed during the oxidation and IF dominated the formed I-DBPs. The formation of I-DBPs was also governed by pH and the maximum formation of I-DBPs occurred at pH 9.0. Transformation pathways of IPM by Fe(VI) oxidation were speculated to proceed through deiodination, amide hydrolysis and oxidation of amine reactions. The deiodination reaction during the oxidation of IPM by Fe(VI) contributed to the formation of I-DBPs. The formation of I-DBPs during the oxidation of IPM by Fe(VI) was significantly higher than those of iohexol, diatrizoate and iopromide, which was consistent with the lowest molecular orbital energy gap of IPM. Although Fe(VI) is considered as a green oxidant, the formation of highly toxic I-DBPs during the oxidation of IPM should receive great attention. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Potentially toxic metals in rivers upstream of Pantanal Norte

    Directory of Open Access Journals (Sweden)

    Geizibel Campos de Magalhães

    2016-11-01

    Full Text Available Cuiabá (CBA and São Lourenço (SL rivers are considered strategic once they integrate regions, which are economically, socially and environmentally relevant for Brazil and the world. However, several activities developed in their watersheds may represent sources of metals and be a threat to the environmental quality. Thus, in this study we evaluated the spatial and temporal variability of potentially toxic metals in water and sediment and the relationship of their concentration with water quality parameters. Surface water samples were collected monthly in 15 points and bottom sediment in nine points distributed throughout both rivers from August 2012 to July 2013. Cr, Cu, Fe, Mn, Pb and Zn were determined in water by inducted coupled plasma optical emission spectrometry and in sediment by flame atomic absorption spectrometry. Fe, Mn, Pb and Cr had high concentrations in water and sediment but only Pb and Cr represent environmental risk. Fe and Mn were in higher concentrations in at the upper points of SL River and Cu and Pb in the urban area of both rivers. Temporally, the metal concentrations were associated with precipitation variation. The observed correlations amongst metal concentrations indicate common sources. Thus, the metals occurrence and concentrations in water and sediment of both rivers showed a natural contribution, as a reflex of soil type associated to the region's precipitation regimen as well as the anthropic contribution due to agricultural and cattle breeding activities, and disposal of untreated urban effluents.

  12. Assessment of Metal Toxicity in Marine Ecosystems: Comparative Toxicity Potentials for Nine Cationic Metals in Coastal Seawater

    DEFF Research Database (Denmark)

    Dong, Yan; Rosenbaum, Ralph K.; Hauschild, Michael Zwicky

    2016-01-01

    This study is a first attempt to develop globally applicable and spatially differentiated marine Comparative Toxicity Potentials (CTPs) or ecotoxicity characterization factors for metals in coastal seawater for use in Life Cycle Assessment. The toxicity potentials are based exclusively on marine...... varies 3-4 orders of magnitude across LMEs, largely due to different seawater residence time. Therefore the highest toxicity potential for metals was found in the LMEs with the longest seawater residence times. Across metals, the highest CTPs were observed for Cd, Pb and Zn. At the concentration levels...... ecotoxicity data and take account of metal speciation and bioavailability. CTPs were developed for nine cationic metals (Cd, Cr(III), Co, Cu(II), Fe(III), Mn, Ni, Pb and Zn) in 64 Large Marine Ecosystems (LMEs) covering all coastal waters in the world. The results showed that the CTP of a specific metal...

  13. POTENTIAL PATHOPHYSIOLOGICAL MECHANISMS OF ULTRAFINE PARTICLE TOXIC EFFECTS IN HUMANS

    Directory of Open Access Journals (Sweden)

    JASMINA JOVIĆ-STOŠIĆ

    2008-03-01

    Full Text Available Epidemiological and clinical studies suggested the association of the particulate matter ambient air pollution and the increased morbidity and mortality, mainly from respiratory and cardiovascular diseases. The size of particles has great influence on their toxicity, because it determines the site in the respiratory tract where they deposit. The most well established theory explaining the mechanisms behind the increased toxicity of ultrafine particles (UFP, < 0.1 µm is that it has to do with the increased surface area and/or the combination with the increased number of particles. Biological effects of UFP are also determined by their shape and chemical composition, so it is not possible to estimate their toxicity in a general way. General hypothesis suggested that exposure to inhaled particles induces pulmonary alveolar inflammation as a basic pathophysiological event, triggering release of various proinflammatory cytokines. Chronic inflammation is a very important underlying mechanism in the genesis of atherosclerosis and cardiovascular diseases. UFP can freely move through the circulation, but their effects on the secondary organs are not known yet, so more studies on recognizing toxicological endpoints of UFP are needed. Determination of UFP toxicity and the estimation of their internal and biologically active dose are necessary for the evidence based conclusions connecting air pollution by UFP and human diseases.

  14. Diversity and dynamics of potentially toxic cyanobacteria and their ...

    African Journals Online (AJOL)

    Bloom–forming freshwater cyanobacteria pose human and livestock health problems due to their ability to produce toxins and other bioactive compounds. Some non-toxic cyanobacteria accumulate as buoyant surface dwelling scums and thick mats which affect the benthic fauna by degrading aquatic habitats and giving ...

  15. Antimicrobial silver: uses, toxicity and potential for resistance.

    Science.gov (United States)

    Mijnendonckx, Kristel; Leys, Natalie; Mahillon, Jacques; Silver, Simon; Van Houdt, Rob

    2013-08-01

    This review gives a comprehensive overview of the widespread use and toxicity of silver compounds in many biological applications. Moreover, the bacterial silver resistance mechanisms and their spread in the environment are discussed. This study shows that it is important to understand in detail how silver and silver nanoparticles exert their toxicity and to understand how bacteria acquire silver resistance. Silver ions have shown to possess strong antimicrobial properties but cause no immediate and serious risk for human health, which led to an extensive use of silver-based products in many applications. However, the risk of silver nanoparticles is not yet clarified and their widespread use could increase silver release in the environment, which can have negative impacts on ecosystems. Moreover, it is shown that silver resistance determinants are widely spread among environmental and clinically relevant bacteria. These resistance determinants are often located on mobile genetic elements, facilitating their spread. Therefore, detailed knowledge of the silver toxicity and resistance mechanisms can improve its applications and lead to a better understanding of the impact on human health and ecosystems.

  16. Synthesis of a novel nanopesticide and its potential toxic effect on soil microbial activity

    Science.gov (United States)

    Liu, Wenjuan; Yao, Jun; Cai, Minmin; Chai, Hankuai; Zhang, Chi; Sun, Jingjing; Chandankere, Radhika; Masakorala, Kanaji

    2014-11-01

    A new nanopesticide, carboxymethyl-β-cyclodextrin-Fe3O4 magnetic nanoparticles-Diuron (CM-β-CD-MNPs-Diuron), was synthesized from an inclusion complex of CM-β-CD-MNPs as host and diuron as guest molecules. The transmission electron microscopy revealed it had an average diameter of 25 nm which is more or less the same as that of MNPs (average diameter 23 nm). The CM-β-CD grafting was confirmed by infrared spectroscopy, and the amount of CM-β-CD grafted on the surface of MNPs was determined to be 144.1 mg/g by thermogravimetry. The feasibility of using CM-β-CD-MNPs as a nanocarrier for loading diuron was verified by investigating the formation of inclusion complex. The complexation of CM-β-CD-MNPs with diuron followed the Langmuir adsorption isotherm. In this work, the potential toxic effect of CM-β-CD-MNPs-Diuron on soil microbial was evaluated by microcalorimetry, urease enzyme and real-time quantitative PCR (qPCR). The thermokinetic parameters were observed to decrease with increase in the loading of CM-β-CD-MNPs-Diuron in soil. The urease activity data showed that there was a significant effect ( p Diuron on the enzyme activity. The microcalorimetric analysis was in agreement with qPCR, confirming the toxic effect of this nanopesticide on microorganism in soil.

  17. Potential synergy between two renal toxicants: DTPA and uranium

    International Nuclear Information System (INIS)

    Muller, D.; Houpert, P.; Henge Napoli, M.H.; Paquet, F.; Muller, D.; Henge Napoli, M.H.; Metivier, H.

    2006-01-01

    At present, the most appropriate therapeutic approach to treat an accidental contamination with plutonium and uranium oxide mixture (MOX) is administration of diethylene-triamine-penta-acetate acid (DTPA) in order to accelerate plutonium excretion. As uranium and DTPA are both nephro-toxic compounds, the administration of DTPA after a contamination containing uranium could enhance the nephro-toxic effects of uranium. The aim of the present work was to study in vitro on a kidney proximal tubule cell line (LLC-PK 1 ) the cytotoxicity induced by increasing concentrations of uranium in presence of 3 different chemical forms of DTPA. The results showed that the DTPA used alone induced no cytotoxicity at the concentration used here (420 μM). However, this concentration of DTPA increased the cytotoxicity induced by uranium. This increase was maximal for uranium concentrations close to the lethal concentration for 50% of the cells and reached 37, 31 and 28% for anhydrous DTPA, Na 3 CaDTPA and Na 3 ZnDTPA, respectively. These results suggest that administration of DTPA could enhance the nephrotoxicity induced by uranium. (authors)

  18. Nanoparticles: Their potential toxicity, waste and environmental management

    International Nuclear Information System (INIS)

    Bystrzejewska-Piotrowska, Grazyna; Golimowski, Jerzy; Urban, Pawel L.

    2009-01-01

    This literature review discusses specific issues related to handling of waste containing nanomaterials. The aims are (1) to highlight problems related to uncontrolled release of nanoparticles to the environment through waste disposal, and (2) to introduce the topics of nanowaste and nanotoxicology to the waste management community. Many nanoparticles used by industry contain heavy metals, thus toxicity and bioaccumulation of heavy metals contained in nanoparticles may become important environmental issues. Although bioavailability of heavy metals contained in nanoparticles can be lower than those present in soluble form, the toxicity resulting from their intrinsic nature (e.g. their size, shape or density) may be significant. An approach to the treatment of nanowaste requires understanding of all its properties - not only chemical, but also physical and biological. Progress in nanowaste management also requires studies of the environmental impact of the new materials. The authors believe Amara's law is applicable to the impact of nanotechnologies, and society might overestimate the short-term effects of these technologies, while underestimating the long-term effects. It is necessary to have basic information from companies about the level and nature of nanomaterials produced or emitted and about the expectation of the life cycle time of nanoproducts as a basis to estimate the level of nanowaste in the future. Without knowing how companies plan to use and store recycled and nonrecycled nanomaterials, development of regulations is difficult. Tagging of nanoproducts is proposed as a means to facilitate separation and recovery of nanomaterials.

  19. Hepatocyte membrane injury and bleb formation following low dose comfrey toxicity in rats.

    Science.gov (United States)

    Yeong, M L; Wakefield, S J; Ford, H C

    1993-04-01

    Comfrey, a popular herbal remedy, contains hepatotoxic pyrrolizidine alkaloids and has been implicated in recent human toxicity. Although alkaloids from other plant sources have been extensively researched, studies on the hepatotoxic effects of comfrey alkaloids are scant. The effects of high dose comfrey toxicity have been studied and the present investigation was undertaken to identify changes associated with relatively low dose toxicity. Eight young adult rats were dosed weekly for six weeks with 50 mg/kg of comfrey derived alkaloids. The animals were dissected one week after the last dose and the livers examined by light and electron microscopy. Changes at the light microscopic level showed vascular congestion, mild zone 3 necrosis and loss of definition of hepatocyte cellular membranes. Extensive ultrastructural abnormalities were identified in the form of endothelial sloughing and the loss of hepatocyte microvilli. A striking finding was florid bleb formation on the sinusoidal borders of hepatocytes. Many blebs were shed into the space of Disse and extruded to fill, and sometimes occlude, sinusoidal lumina. Platelets were frequently found in areas of bleb formation. There was evidence of late damage in collagenization of Disse's space. Hepatocyte bleb formation is known to occur under a variety of pathological conditions but there is little to no information in the literature on the effects, if any, of bleb formation on fibrogenesis and the microcirculation and its role in the pathogenesis of liver disease. The pyrrolizidine alkaloids of comfrey may serve as an experimental tool to study the process of bleb formation and the intimate relationship between hepatocyte and sinusoidal injury in the liver.

  20. Potential carcinogenicity predicted by computational toxicity evaluation of thiophosphate pesticides using QSTR/QSCarciAR model.

    Science.gov (United States)

    Petrescu, Alina-Maria; Ilia, Gheorghe

    2017-07-01

    This study presents in silico prediction of toxic activities and carcinogenicity, represented by the potential carcinogenicity DSSTox/DBS, based on vector regression with a new Kernel activity, and correlating the predicted toxicity values through a QSAR model, namely: QSTR/QSCarciAR (quantitative structure toxicity relationship/quantitative structure carcinogenicity-activity relationship) described by 2D, 3D descriptors and biological descriptors. The results showed a connection between carcinogenicity (compared to the structure of a compound) and toxicity, as a basis for future studies on this subject, but each prediction is based on structurally similar compounds and the reactivation of the substructures of these compounds.

  1. Potential for photoenhanced toxicity of spilled oil in Prince William Sound and Gulf of Alaska Waters

    Energy Technology Data Exchange (ETDEWEB)

    Barron, M.G. [P.E.A.K. Research, Longmont, CO (United States); Ka' aihue, L. [Prince William Sound Regional Citizens' Advisory Council, Anchorage, AK (United States)

    2001-07-01

    Photoenhanced toxicity is the increase in the toxicity of a chemical in the presence of ultraviolet light (UV) compared to a standard laboratory test conducted with fluorescent lighting (minimal UV). Oil products, weathered oil, and specific polycyclic aromatic compounds present in oil are 2 to greater than 1000 times more toxic in the presence of UV. The photoenhanced toxicity of oil to fish and aquatic invertebrates appears to occur through a process of photosensitization, rather than photomodification of the aqueous phase oil. In photosensitization, the bioaccumulated chemical transfers light energy to other molecules causing toxicity through tissue damage rather than a narcosis mechanism. The available evidence indicates that phototoxic components of oil are specific 3-5 ring polycyclic aromatic hydrocarbons (PAHs) and heterocycles. Determinants of photoenhanced toxicity include the extent of oil bioaccumulation in aquatic organisms and the spectra and intensity of UV exposure. No studies have specifically investigated the photoenhanced toxicity of spilled oil in Alaska waters. Although there are substantial uncertainties, the results of this evaluation indicate there is potential for photoenhanced toxicity of spilled oil in Prince William Sound and the Gulf of Alaska. The potential hazard of photoenhanced toxicity may be greatest for embryo and larval stages of aquatic organisms that are relatively translucent to UV and inhabit the photic zone of the water column and intertidal areas. Photoenhanced toxicity should be considered in oil spill response because the spatial and temporal extent of injury to aquatic organisms may be underestimated if based on standard laboratory bioassays and existing toxicity databases. Additionally, the choice of counter measures and oil removal operations may influence the degree of photoenhanced toxicity. (author)

  2. In vitro and in vivo toxicity studies of copper sulfide nanoplates for potential photothermal applications.

    Science.gov (United States)

    Feng, Wei; Nie, Wei; Cheng, Yanhua; Zhou, Xiaojun; Chen, Liang; Qiu, Kexin; Chen, Zhigang; Zhu, Meifang; He, Chuanglong

    2015-05-01

    Copper sulfide (CuS) has emerged as a promising photothermal agent. However, its potential toxic effects still remained poorly understood. Herein, CuS nanoplates were synthesized for toxicity assessment. The in vitro study indicated that the cell viability decreased when CuS nanoplate concentration was higher than 100 μg/mL. CuS nanoplates caused apparent toxicity to HUVEC and RAW 264.7 cells. For acute toxicity, maximum tolerated dose and lethal dose 50 were 8.66 and 54.5 mg/kg, respectively. Furthermore, the sub-chronic toxicity test results indicated that there was no obvious effect at tested doses during the test period. The biodistribution study showed that intravenously administrated CuS nanoplates were mainly present in the spleen, liver and lung. Taken together, our results shed light on the rational design of CuS nanomaterials to minimize toxicity, thus providing a useful guideline in selecting CuS as the photothermal agent for cancer therapy. Photothermal ablation therapy is a promising new treatment modality for cancer. One of the potential photothermal agents is copper sulfide (CuS). In this article, the potential toxic effects of CuS nanoplates were studied. The authors showed that further modification on the design of CuS nanomaterials was needed to minimize toxicity. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. [Research progress on potential liver toxic components in traditional Chinese medicine].

    Science.gov (United States)

    Wu, Hao; Zhong, Rong-Ling; Xia, Zhi; Huang, Hou-Cai; Zhong, Qing-Xiang; Feng, Liang; Song, Jie; Jia, Xiao-Bin

    2016-09-01

    In recent years, the proportion of traditional Chinese medicine in scientific research and its clinical use increased gradually. The research result also becomes more and more valuable, but in the process of using traditional Chinese medicine, it also needs to pay more attention. With the gradual deepening of the toxicity of traditional Chinese medicine, some traditional Chinese medicines have also been found to have the potential toxicity, with the exception of some traditional toxicity Chinese medicine. Traditional Chinese medicine in the growth, processing, processing, transportation and other aspects of pollution or deterioration will also cause the side effects to the body. Clinical practice should be based on the theory of traditional Chinese medicine to guide rational drug use and follow the symptomatic medication, the principle of proper compatibility. The constitution of the patients are different, except for a few varieties of traditional Chinese medicines are natural herbs with hepatotoxicity, liver toxicity of most of the traditional Chinese medicine has idiosyncratic features. The liver plays an important role in drug metabolism. It is easy to be damaged by drugs. Therefore, the study of traditional Chinese medicine potential liver toxicity and its toxic components has become one of the basic areas of traditional Chinese medicine research. Based on the review of the literatures, this paper summarizes the clinical classification of liver toxicity, the pathogenesis of target cell injury, and systematically summarizes the mechanism of liver toxicity and toxic mechanism of traditional Chinese medicine. This paper provided ideas for the study of potential liver toxicity of traditional Chinese medicine and protection for clinical safety of traditional Chinese medicine. Copyright© by the Chinese Pharmaceutical Association.

  4. A high throughput passive dosing format for the Fish Embryo Acute Toxicity test

    DEFF Research Database (Denmark)

    Vergauwen, Lucia; Nørgaard Schmidt, Stine; Stinckens, Evelyn

    2015-01-01

    High throughput testing according to the Fish Embryo Acute Toxicity (FET) test (OECD Testing Guideline 236) is usually conducted in well plates. In the case of hydrophobic test substances, sorptive and evaporative losses often result in declining and poorly controlled exposure conditions. Therefore......, our objective was to improve exposure conditions in FET tests by evaluating a passive dosing format using silicone O-rings in standard 24-well polystyrene plates. We exposed zebrafish embryos to a series of phenanthrene concentrations until 120 h post fertilization (hpf), and obtained a linear...

  5. Potential air toxics hot spots in truck terminals and cabs.

    Science.gov (United States)

    Smith, Thomas J; Davis, Mary E; Hart, Jaime E; Blicharz, Andrew; Laden, Francine; Garshick, Eric

    2012-12-01

    Hot spots are areas where concentrations of one or more air toxics--organic vapors or particulate matter (PM)--are expected to be elevated. The U.S. Environmental Protection Agency's (EPA*) screening values for air toxics were used in our definition of hot spots. According to the EPA, a screening value "is used to indicate a concentration of a chemical in the air to which a person could be continually exposed for a lifetime ... and which would be unlikely to result in a deleterious effect (either cancer or noncancer health effects)" (U.S. EPA 2006). Our characterization of volatile organic compounds (VOCs; namely 18 hydrocarbons, methyl tert-butyl ether [MTBE], acetone, and aldehydes) was added onto our ongoing National Cancer Institute-funded study of lung cancer and particulate pollutant concentrations (PM with an aerodynamic diameter highways. In Phase 1 of our study, 15 truck terminals across the United States were each visited for five consecutive days. During these site visits, sorbent tubes were used to collect 12-hour integrated samples of hydrocarbons and aldehydes from upwind and downwind fence-line locations as well as inside truck cabs. Meteorologic data and extensive site information were collected with each sample. In Phase 2, repeat visits to six terminals were conducted to test the stability of concentrations across time and judge the representativeness of our previous measurements. During the repeat site visits, the sampling procedure was expanded to include real-time sampling for total hydrocarbon (HC) and PM2.5 at the terminal upwind and downwind sites and inside the truck cabs, two additional monitors in the yard for four-quadrant sampling to better characterize the influence of wind, and indoor sampling in the loading dock and mechanic shop work areas. Mean and median concentrations of VOCs across the sampling locations in and around the truck terminals showed significant variability in the upwind concentrations as well as in the intensity of

  6. Triorganotin as a compound with potential reproductive toxicity in mammals

    Directory of Open Access Journals (Sweden)

    V.S. Delgado Filho

    2011-09-01

    Full Text Available Organotin compounds are typical environmental contaminants and suspected endocrine-disrupting substances, which cause irreversible sexual abnormality in female mollusks, called "imposex". However, little is known about the capability of triorganotin compounds, such as tributyltin and triphenyltin, to cause disorders in the sexual development and reproductive functions of mammals, including humans and rodents. Moreover, these compounds can act as potential competitive inhibitors of aromatase enzyme and other steroidogenic enzymes, affecting the reproductive capacity of male and female mammals. In this review, we discuss the cellular, biochemical, and molecular mechanisms by which triorganotin compounds induce adverse effects in the mammalian reproductive function.

  7. Molecular Detection of a Potentially Toxic Diatom Species

    Directory of Open Access Journals (Sweden)

    Bidhan Chandra Dhar

    2015-05-01

    Full Text Available A few diatom species produce toxins that affect human and animal health. Among these, members of the Pseudo-nitzschia genus were the first diatoms unambiguously identified as producer of domoic acid, a neurotoxin affecting molluscan shell-fish, birds, marine mammals, and humans. Evidence exists indicating the involvement of another diatom genus, Amphora, as a potential producer of domoic acid. We present a strategy for the detection of the diatom species Amphora coffeaeformis based on the development of species-specific oligonucleotide probes and their application in microarray hybridization experiments. This approach is based on the use of two marker genes highly conserved in all diatoms, but endowed with sufficient genetic divergence to discriminate diatoms at the species level. A region of approximately 450 bp of these previously unexplored marker genes, coding for elongation factor 1-a (eEF1-a and silicic acid transporter (SIT, was used to design oligonucleotide probes that were tested for specificity in combination with the corresponding fluorescently labeled DNA targets. The results presented in this work suggest a possible use of this DNA chip technology for the selective detection of A. coffeaeformis in environmental settings where the presence of this potential toxin producer may represent a threat to human and animal health. In addition, the same basic approach can be adapted to a wider range of diatoms for the simultaneous detection of microorganisms used as biomarkers of different water quality levels.

  8. Investigation on the toxic potential of Tribulus terrestris in vitro.

    Science.gov (United States)

    Abudayyak, M; Jannuzzi, A T; Özhan, G; Alpertunga, B

    2015-04-01

    Tribulus terrestris L. (Zygophyllaceae) has been commonly used to energize, vitalize, and improve sexual function and physical performance in men. This study investigates the potential cytotoxic and genotoxic, and endocrine disrupting activities of T. terrestris in vitro. The whole T. terrestris plant was extracted with water, methanol, and chloroform. The genotoxic potential of T. terrestris extracts at 3-2400 µg/mL was assessed by Comet assay in a rat kidney cell line (NRK-52E) and by Ames assay in Salmonella typhimurium TA98 and TA100 strains. Endocrine disrupting effects of the extracts at concentrations of 0.22-25 000 µg/mL were assessed by YES/YAS assay in Saccharomyces cerevisiae. Cytotoxic activity of the extracts was determined by the MTT test in NRK-52E cells. The different exposure times were used for four tests (3-48 h). The methanol extract of T. terrestris IC50 value was 160 µg/mL. The other extracts did not show cytotoxic effects. In the Comet and Ames genotoxicity assays, none of the extracts possessed genotoxic activities at concentrations of 0-2400 µg/mL. Only the water extract of T. terrestris induced frame shift mutations after metabolic activation. The water extract also showed estrogenic activity by YES/YAS assay in S. cerevisiae at concentrations ≥27 µg/mL (≥2.6-fold), while the other T. terrestris extracts had anti-estrogenic properties. Tribulus terrestris had estrogenic and genotoxic activities. The study was useful in determining its toxicological effects and the precautions regarding consumption.

  9. Identification of potential toxicity caused by O3 and ClO2 treatment of pharmaceuticals in wastewater

    DEFF Research Database (Denmark)

    Furuhagen, S. M.; Hörsing, Maritha; Ledin, Anna

    2011-01-01

    Chemical oxidation treatment is an effective innovative technology in wastewater treatment plants for removal of micro-pollutants in the effluent. In particular, ozonation (O3) and chlorine dioxide (ClO2) treatments are commonly used to degrade organic pollutants. By oxidation, the micro...... Carbamazepine by chemical oxidation were more harmful to aquatic organisms compared to the parent compound. The aim of our study is to evaluate the potential risk of oxidation treatment, using O3 and ClO2, due to formation of toxic transformation products. The ecotoxicological effects caused by the two...... oxidation treatments were evaluated for milli-Q water spiked with an API-mixture (containing 114 pharmaceuticals), wastewater (WW) and WW spiked with the API-mixture. Tests were conducted to evaluate the toxicity of the API-mixture itself and the spiked waters had an API concentration corresponding...

  10. Sensitive bromine-based screening of potential toxic furanoids in Dioscorea bulbifera L.

    Science.gov (United States)

    Zhang, Zhengyu; Lin, Dongju; Li, Weiwei; Gao, Huiyuan; Peng, Ying; Zheng, Jiang

    2017-07-01

    Numerous furanoids have been reported to be toxic, and many of them were found in herbal medicines. Toxicities of furanoids are suggested to result from the generation of cis-enedials via biotransformation. The detection of the electrophilic metabolic intermediates is a challenge. Earlier, we developed a selective approach to screen potential toxic furanoids, through which we found two major furanoids, diosbulbin B and 8-epidiosbulbin E acetate, in Dioscorea bulbifera L., a known furanoid-containing and hepatotoxic herbal medicine. In the present study, we improved the approach to analyze furanoids in D. bulbifera L., which allowed us to detect additional six potential furanoids, including diosbulbin A, diosbulbin D, diosbulbin E, diosbulbin F, diosbulbin M, and diosbulbin D glycoside. The achievements of this study enhanced the sensitivity to screen potential toxic furanoids through elevating S/N values by approximately 3 times. This will facilitate the understanding of mechanisms of toxic actions of D. bulbifera L. and other furanoid-containing toxic herbal medicines. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Predicting hydrocarbon potential of an earth formation underlying water

    International Nuclear Information System (INIS)

    Damaison, G.J.; Kaplan, I.R.

    1981-01-01

    A method for the on-site collection and examination of small concentrations of a carbonaceous gas, e.g. methane, dissolved in a body of water overlying an earth formation to predict hydrocarbon potential of the earth formation under the body of water, the formation being a source of carbonaceous gas, comprises at a known geographic location sampling the water at a selected flow rate and at a selected depth; continuously vacuum separating the water into liquid and gas phases; separating a selected carbonaceous gas from interfering gas species in the presence of an air carrier vented to atmosphere at a known flow rate; and quantitatively oxidizing the selected gas and then cryogenically trapping an oxidant thereof in the presence of said air carrier to provide for an accurate isotopic examination. (author)

  12. Interaction between sulfur and lead in toxicity, iron plaque formation and lead accumulation in rice plant.

    Science.gov (United States)

    Yang, Junxing; Liu, Zhiyan; Wan, Xiaoming; Zheng, Guodi; Yang, Jun; Zhang, Hanzhi; Guo, Lin; Wang, Xuedong; Zhou, Xiaoyong; Guo, Qingjun; Xu, Ruixiang; Zhou, Guangdong; Peters, Marc; Zhu, Guangxu; Wei, Rongfei; Tian, Liyan; Han, Xiaokun

    2016-06-01

    Human activities have resulted in lead and sulfur accumulation in paddy soils in parts of southern China. A combined soil-sand pot experiment was conducted to investigate the influence of S supply on iron plaque formation and Pb accumulation in rice (Oryza sativa L.) under two Pb levels (0 and 600 mg kg(-1)), combined with four S concentrations (0, 30, 60, and 120 mg kg(-1)). Results showed that S supply significantly decreased Pb accumulation in straw and grains of rice. This result may be attributed to the enhancement of Fe plaque formation, decrease of Pb availability in soil, and increase of reduced glutathione (GSH) in rice leaves. Moderate S supply (30 mg kg(-1)) significantly increased Fe plaque formation on the root surface and in the rhizosphere, whereas excessive S supply (60 and 120 mg kg(-1)) significantly decreased the amounts of iron plaque on the root surface. Sulfur supply significantly enhanced the GSH contents in leaves of rice plants under Pb treatment. With excessive S application, the rice root acted as a more effective barrier to Pb accumulation compared with iron plaque. Excessive S supply may result in a higher monosulfide toxicity and decreased iron plaque formation on the root surface during flooded conditions. However, excessive S supply could effectively decrease Pb availability in soils and reduce Pb accumulation in rice plants. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. The potential role of earthworms in toxicity assessment of terrestrial hazardous waste sites

    Energy Technology Data Exchange (ETDEWEB)

    Goven, A.J.; Fitzpatrick, L.C. [Univ. of North Texas, Denton, TX (United States); Venables, B.J. [TRAC Labs., Inc., Denton, TX (United States)

    1994-12-31

    Understanding the toxic potential and mechanisms of action of environmental xenobiotics is fundamental for assessing risk to public and environmental health. Current established protocols with earthworms focus primarily on defining the lethal effects of chemicals associated with soil contamination. Development of sublethal assays, until recently, has been largely ignored. Here the authors develop rationale for use of earthworms as a model organism for comprehensive assessment of risks to higher wildlife from contaminated soils and hazardous waste sites. They present a panel of lethal (LC/LD50`s) and sublethal measurement endpoint biomarkers, developed within the framework of the National Toxicology Program`s tiered immunotoxicity protocol for mice and according to published criteria for good measurement endpoints, that represent sensitive phylogenetically-conserved processes. Specifically the authors discuss immunosuppressive effects of terrestrial heavy metal and organic contamination on the innate, nonspecific and specific immune responses of earthworm, Lumbricus terrestris, coelomocytes in terms of total and differential cell counts, lysozyme activity, nitroblue tetrazolium dye reduction, phagocytic activity and secretary rosette formation. Findings indicate that sensitive phylogenetically conserved immune responses present in invertebrates can be used to assess or predict risk to wildlife from contaminated soils.

  14. Estimating the Potential Toxicity of Chemicals Associated with Hydraulic Fracturing Operations Using Quantitative Structure-Activity Relationship Modeling

    Science.gov (United States)

    Researchers facilitated evaluation of chemicals that lack chronic oral toxicity values using a QSAR model to develop estimates of potential toxicity for chemicals used in HF fluids or found in flowback or produced water

  15. Secondary organic aerosols: Formation potential and ambient data

    DEFF Research Database (Denmark)

    Barthelmie, R.J.; Pryor, S.C.

    1997-01-01

    Organic aerosols comprise a significant fraction of the total atmospheric particle loading and are associated with radiative forcing and health impacts. Ambient organic aerosol concentrations contain both a primary and secondary component. Herein, fractional aerosol coefficients (FAC) are used...... in conjunction with measurements of volatile organic compounds (VOC) to predict the formation potential of secondary organic aerosols (SOA) in the Lower Fraser Valley (LEV) of British Columbia. The predicted concentrations of SOA show reasonable accord with ambient aerosol measurements and indicate considerable...

  16. Field Validation of Toxicity Tests to Evaluate the Potential for Beneficial Use of Produced Water

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Bidwell; Jonathan Fisher; Naomi Cooper

    2008-03-31

    This study investigated potential biological effects of produced water contamination derived from occasional surface overflow and possible subsurface intrusion at an oil production site along the shore of Skiatook Lake, Oklahoma. We monitored basic chemistry and acute toxicity to a suite of standard aquatic test species (fathead minnow-Pimephales promelas, Daphnia pulex, Daphnia magna, and Ceriodaphnia dubia) in produced water and in samples taken from shallow groundwater wells on the site. Toxicity identification evaluations and ion toxicity modeling were used to identify toxic constituents in the samples. Lake sediment at the oil production site and at a reference site were also analyzed for brine intrusion chemically and by testing sediment toxicity using the benthic invertebrates, Chironomus dilutus, and Hyallela azteca. Sediment quality was also assessed with in situ survival and growth studies with H. azteca and the Asian clam, Corbicula fluminea, and by benthic macroinvertebrate community sampling. The produced water was acutely toxic to the aquatic test organisms at concentrations ranging from 1% to 10% of the whole produced water sample. Toxicity identification evaluation and ion toxicity modeling indicated major ion salts and hydrocarbons were the primary mixture toxicants. The standardized test species used in the laboratory bioassays exhibited differences in sensitivity to these two general classes of contaminants, which underscores the importance of using multiple species when evaluating produced water toxicity. Toxicity of groundwater was greater in samples from wells near a produced water injection well and an evaporation pond. Principle component analyses (PCA) of chemical data derived from the groundwater wells indicated dilution by lake water and possible biogeochemical reactions as factors that ameliorated groundwater toxicity. Elevated concentrations of major ions were found in pore water from lake sediments, but toxicity from these ions was

  17. Mobility and Attenuation Dynamics of Potentially Toxic Chemical Species at an Abandoned Copper Mine Tailings Dump

    Directory of Open Access Journals (Sweden)

    Wilson Mugera Gitari

    2018-02-01

    Full Text Available Large volumes of disposed mine tailings abound in several regions of South Africa, as a consequence of unregulated, unsustainable long years of mining activities. Tailings dumps occupy a large volume of valuable land, and present a potential risk for aquatic systems, through leaching of potentially toxic chemical species. This paper reports on the evaluation of the geochemical processes controlling the mobility of potentially toxic chemical species within the tailings profile, and their potential risk with regard to surface and groundwater systems. Combination of X-ray fluorescence (XRF, X-ray diffraction (XRD, and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS techniques, show that the tailing profiles are uniform, weakly altered, and vary slightly with depth in both physical and geochemical properties, as well as mineralogical composition. Mineralogical analysis showed the following order of abundance: quartz > epidote > chlorite > muscovite > calcite > hematite within the tailings profiles. The neutralization of the dominant alumino-silicate minerals and the absence of sulfidic minerals, have produced medium alkaline pH conditions (7.97–8.37 at all depths and low concentrations of dissolved Cu (20.21–47.9 µg/L, Zn (0.88–1.80 µg/L, Pb (0.27–0.34 µg/L, and SO42− (15.71–55.94 mg/L in the tailings profile leachates. The relative percentage leach for the potentially toxic chemical species was low in the aqueous phase (Ni 0.081%, Cu 0.006%, and Zn 0.05%. This indicates that the transport load of potentially toxic chemical species from tailings to the aqueous phase is very low. The precipitation of secondary hematite has an important known ability to trap and attenuate the mobility of potentially toxic chemical species (Cu, Zn, and Pb by adsorption on the surface area. Geochemical modelling MINTEQA2 showed that the tailings leachates were below saturation regarding oxyhydroxide minerals, but oversaturated with Cu

  18. Chemical compounds toxic to invertebrates isolated from marine cyanobacteria of potential relevance to the agricultural industry.

    Science.gov (United States)

    Essack, Magbubah; Alzubaidy, Hanin S; Bajic, Vladimir B; Archer, John A C

    2014-10-29

    In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.

  19. Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

    KAUST Repository

    Essack, Magbubah

    2014-10-29

    In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.

  20. Dietary exposure to essential and potentially toxic elements for the population of Hanoi, Vietnam

    DEFF Research Database (Denmark)

    Marcussen, H.; Jensen, Bodil Hamborg; Petersen, Annette

    2013-01-01

    and there is a need to build more knowledge so that authorities can give dietary recommendations. The aim of this study was to determine the total dietary intake of essential and potentially toxic elements and to assess the nutritional quality and food safety risks of the average Hanoi diet. 22 foods or food groups...... were identified and 14 samples of each food group were collected from markets and/or supermarkets in the period 2007-2009. Water spinach, water dropwort, watercress, water mimosa and pond fish are typically produced in wastewater-fed systems. Therefore, these samples were collected both at markets...... and from wastewater-fed production systems. The results showed little or no risk of toxic elements from the Hanoi diet in general. Further, element contributions from wastewater-fed products were low and does not seem to constitute a problem with respect to potentially toxic elements. A comparison...

  1. Chemical Compounds Toxic to Invertebrates Isolated from Marine Cyanobacteria of Potential Relevance to the Agricultural Industry

    Directory of Open Access Journals (Sweden)

    Magbubah Essack

    2014-10-01

    Full Text Available In spite of advances in invertebrate pest management, the agricultural industry is suffering from impeded pest control exacerbated by global climate changes that have altered rain patterns to favour opportunistic breeding. Thus, novel naturally derived chemical compounds toxic to both terrestrial and aquatic invertebrates are of interest, as potential pesticides. In this regard, marine cyanobacterium-derived metabolites that are toxic to both terrestrial and aquatic invertebrates continue to be a promising, but neglected, source of potential pesticides. A PubMed query combined with hand-curation of the information from retrieved articles allowed for the identification of 36 cyanobacteria-derived chemical compounds experimentally confirmed as being toxic to invertebrates. These compounds are discussed in this review.

  2. Evaluating Potential Risks of Food Allergy and Toxicity of Soy Leghemoglobin Expressed in Pichia pastoris.

    Science.gov (United States)

    Jin, Yuan; He, Xiaoyun; Andoh-Kumi, Kwame; Fraser, Rachel Z; Lu, Mei; Goodman, Richard E

    2018-01-01

    The Soybean (Glycine max) leghemoglobin c2 (LegHb) gene was introduced into Pichia pastoris yeast for sustainable production of a heme-carrying protein, for organoleptic use in plant-based meat. The potential allergenicity and toxicity of LegHb and 17 Pichia host-proteins each representing ≥1% of total protein in production batches are evaluated by literature review, bioinformatics sequence comparisons to known allergens or toxins, and in vitro pepsin digestion. Literature searches found no evidence of allergenicity or toxicity for these proteins. There are no significant sequence matches of LegHb to known allergens or toxins. Eleven Pichia proteins have modest identity matches to minor environmental allergens and 13 Pichia proteins have significant matches to proteins from toxic sources. Yet the matched allergens and toxins have similar matches to proteins from the commonly consumed yeast Saccharomyces cerevisiae, without evidence of food allergy or toxicity. The demonstrated history of safe use indicates additional tests for allergenicity and toxicity are not needed. The LegHb and Pichia sp. proteins were rapidly digested by pepsin at pH 2. These results demonstrate that foods containing recombinant soy LegHb produced in Pichia sp. are unlikely to present an unacceptable risk of allergenicity or toxicity to consumers. © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. The luminescent bacteria toxicity test: its potential as an in vitro alternative.

    Science.gov (United States)

    Bulich, A A; Tung, K K; Scheibner, G

    1990-01-01

    During the past several years, the use of animals for toxicity testing has come under critical surveillance. For ethical and economic reasons, various techniques have been developed and proposed as potential alternatives for some of the whole animal toxicity assays. One assay proposed as an alternative to animal testing is the luminescent bacteria toxicity test (LBT), provided under the trade name of Microtox. The sensitivity and specificity of the LBT was compared with two commonly used toxicity tests--the L-929 Minimal Eàgle's Medium (MEM) elution cytotoxicity test and the Draize test. Cytotoxicity and LBT test data from 709 medical device and biomaterial extracts were compared using a positive/negative ranking system which provided a measurement of false positive and false negative results. These data were compiled from nine separate laboratories producing or using a wide variety of biomaterials and medical device products. The LBT was more sensitive than the tissue culture assay and displayed few false negatives. LBT EC50 values were compared with eye irritancy categories for a group of 34 chemicals and 27 personal care products. As with tissue culture, the LBT was more sensitive and produced minimal false negatives. The data from this study indicate the LBT has potential as a rapid, simple method to screen biomaterials and personal care products for toxicity and irritancy.

  4. Distribution and habitat specificity of potentially-toxic Microcystis across climate, land and water use gradients.

    Directory of Open Access Journals (Sweden)

    Sophi eMarmen

    2016-03-01

    Full Text Available Toxic cyanobacterial blooms are a growing threat to freshwater bodies worldwide. In order for a toxic bloom to occur, a population of cells with the genetic capacity to produce toxins must be present together with the appropriate environmental conditions. In this study, we investigated the distribution patterns and phylogeny of potentially-toxic Microcystis (indicated by the presence and/or phylogeny of the mcyD and mcyA genes. Samples were collected from the water column of almost sixty water bodies across widely differing gradients of environmental conditions and land use in Israel. Potentially toxic populations were common but not ubiquitous, detected in ~65% of the studied sites. Local environmental factors, including phosphorus and ammonia concentrations and pH, as well as regional conditions such as the distance from built areas and nature reserves, were correlated with the distribution of the mcyD gene. A specific phylogenetic clade of Microcystis, defined using the sequence of the mcyA gene, was preferentially associated with aquaculture facilities but not irrigation reservoirs. Our results reveal important environmental, geospatial, and land use parameters affecting the geographic distribution of toxinogenic Microcystis, suggesting non-random dispersal of these globally abundant toxic cyanobacteria.

  5. Safety Evaluation of Potential Toxic Metals Exposure from Street Foods Consumed in Mid-West Nigeria

    Directory of Open Access Journals (Sweden)

    O. C. Ekhator

    2017-01-01

    Full Text Available Objective. Street-vended foods offer numerous advantages to food security; nevertheless, the safety of street food should be considered. This study has investigated the level of potential toxic metal (Pb, Cd, Hg, Sb, Mn, and Al contamination among street-vended foods in Benin City and Umunede. Methods. Twenty street food samples were purchased from vendors at bus stops. Metals were analyzed with atomic absorption spectrophotometry. The methods developed by the US EPA were employed to evaluate the potential health risk of toxic metals. Results. The concentrations of the toxic metals in mg/kg were in the range of Pb (0.014–1.37, Cd (0.00–0.00017, Hg (0.00–0.00014, Sb (0.00–0.021, Mn (0.00–0.012, and Al (0.00–0.22. All the toxic metals except Pb were below permissible limit set by WHO, EU, and USEPA. The daily intake, hazard quotient, and hazard index of all toxic metals except for Pb in some street foods were below the tolerable daily intake and threshold value of 1, indicating an insignificant health risk. Total cancer risk was within the priority risk level of 1.0E-04 but higher than the acceptable risk level of 1E-06. Conclusion. Consumption of some of these street foods is of public health concern.

  6. Environmental toxicity and radioactivity assessment of a titanium-processing residue with potential for environmental use.

    Science.gov (United States)

    Wendling, Laura A; Binet, Monique T; Yuan, Zheng; Gissi, Francesca; Koppel, Darren J; Adams, Merrin S

    2013-07-01

    Thorough examination of the physicochemical characteristics of a Ti-processing residue was undertaken, including mineralogical, geochemical, and radiochemical characterization, and an investigation of the environmental toxicity of soft-water leachate generated from the residue. Concentrations of most metals measured in the leachate were low; thus, the residue is unlikely to leach high levels of potentially toxic elements on exposure to low-ionic strength natural waters. Relative to stringent ecosystem health-based guidelines, only chromium concentrations in the leachate exceeded guideline concentrations for 95% species protection; however, sulfate was present at concentrations known to cause toxicity. It is likely that the high concentration of calcium and extreme water hardness of the leachate reduced the bioavailability of some elements. Geochemical modeling of the leachate indicated that calcium and sulfate concentrations were largely controlled by gypsum mineral dissolution. The leachate was not toxic to the microalga Chlorella sp., the cladoceran Ceriodaphnia dubia, or the estuarine bacterium Vibrio fischeri. The Ti-processing residue exhibited an absorbed dose rate of 186 nGy/h, equivalent to an annual dose of 1.63 mGy and an annual effective dose of 0.326 mGy. In summary, the results indicate that the Ti-processing residue examined is suitable for productive use as an environmental amendment following 10 to 100 times dilution to ameliorate potential toxic effects due to chromium or sulfate. Copyright © 2013 SETAC.

  7. Radioiodine therapy of benign non-toxic goitre. Potential role of recombinant human TSH

    DEFF Research Database (Denmark)

    Fast, S; Bonnema, S J; Hegedüs, L

    2011-01-01

    This review provides an update on recombinant human TSH (rh-TSH) augmented radioiodine (¹³¹I) therapy and outlines its potential role in the treatment of symptomatic benign multinodular non-toxic goitre. In some countries, ¹³¹I has been used for three decades to reduce the size of nodular goitres...

  8. GLUCOCORTICOID RECEPTOR REGULATION IN THE RAT EMBRYO: A POTENTIAL SITE FOR DEVELOPMENTAL TOXICITY?

    Science.gov (United States)

    Glucocorticoid receptor regulation in the rat embryo: a potential site for developmental toxicity?Ghosh B, Wood CR, Held GA, Abbott BD, Lau C.National Research Council, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, USA.

  9. Mapping the Potentially Affected Fraction (PAF) of species as an indicator of generic toxic stress

    NARCIS (Netherlands)

    Klepper O; Meent D van de; ECO

    1997-01-01

    The Potentially Affected Fraction (PAF) is the fraction of species exposed above the no-effect concentration (NOEC). The PAF is a measure that allows a comparison in toxic stress between substances and areas. In the report the PAF is calculated for four heavy metals (cadmium, copper, lead and zinc)

  10. SMOG-CHAMBER TOXICOLOGY BETTER ESTIMATES THE TRUE TOXIC POTENTIAL OF ATMOSPHERIC MIXTURES

    Science.gov (United States)

    The chemistry of hazardous air pollutants (HAPs) have been studied for many years, yet little is known about how these chemicals, once interacted with urban atmospheres, affect healthy and susceptible individuals. The toxic potential of these very reactive compounds once they int...

  11. SOA formation potential of emissions from soil and leaf litter.

    Science.gov (United States)

    Faiola, Celia L; Vanderschelden, Graham S; Wen, Miao; Elloy, Farah C; Cobos, Douglas R; Watts, Richard J; Jobson, B Thomas; Vanreken, Timothy M

    2014-01-21

    Soil and leaf litter are significant global sources of small oxidized volatile organic compounds, VOCs (e.g., methanol and acetaldehyde). They may also be significant sources of larger VOCs that could act as precursors to secondary organic aerosol (SOA) formation. To investigate this, soil and leaf litter samples were collected from the University of Idaho Experimental Forest and transported to the laboratory. There, the VOC emissions were characterized and used to drive SOA formation via dark, ozone-initiated reactions. Monoterpenes dominated the emission profile with emission rates as high as 228 μg-C m(-2) h(-1). The composition of the SOA produced was similar to biogenic SOA formed from oxidation of ponderosa pine emissions and α-pinene. Measured soil and litter monoterpene emission rates were compared with modeled canopy emissions. Results suggest surface soil and litter monoterpene emissions could range from 12 to 136% of canopy emissions in spring and fall. Thus, emissions from leaf litter may potentially extend the biogenic emissions season, contributing to significant organic aerosol formation in the spring and fall when reduced solar radiation and temperatures reduce emissions from living vegetation.

  12. The ‘SILENT Alarm’: When History Taking Reveals a Potentially Fatal Toxicity

    Directory of Open Access Journals (Sweden)

    Sapir Anani

    2018-03-01

    Full Text Available Introduction: The combination of acute/sub-acute neurological and metabolic derangements should always raise the suspicion of toxicity, either endogenous or exogenous. The adverse effects of psychiatric medications are especially difficult to determine since the psychiatric background of patients is often inaccessible. Clinical Presentation: A 66-year-old man presented to the emergency department with dysarthria and uncontrolled tremor, rapidly deteriorating into a complex of severe neurological and metabolic derangements. Only after repeated attempts to take a thorough history was lithium toxicity identified. Conclusion: Thorough, comprehensive history taking, including chronic medications and their substitutes, is essential and lifesaving when potentially lethal medications are involved.

  13. Acute embryo toxicity and teratogenicity of three potential biofuels also used as flavor or solvent

    Energy Technology Data Exchange (ETDEWEB)

    Bluhm, Kerstin; Seiler, Thomas-Benjamin [RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen (Germany); Anders, Nico [RWTH Aachen University, Aachener Verfahrenstechnik — Enzyme Process Technology, Worringerweg 1, 52074 Aachen (Germany); Klankermayer, Jürgen [RWTH Aachen University, Institut für Technische und Makromolekulare Chemie, Worringerweg 1, 52074 Aachen (Germany); Schaeffer, Andreas [RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen (Germany); Chongqing University, College of Resources and Environmental Science, Chongqing 400715 (China); Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing 210093 (China); Hollert, Henner, E-mail: Henner.Hollert@bio5.rwth-aachen.de [RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen (Germany); Chongqing University, College of Resources and Environmental Science, Chongqing 400715 (China); Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing 210093 (China); Tongji University, College of Environmental Science and Engineering and State Key Laboratory of Pollution Control and Resource Reuse, Shanghai 200092 (China)

    2016-10-01

    The demand for biofuels increases due to concerns regarding greenhouse gas emissions and depletion of fossil oil reserves. Many substances identified as potential biofuels are solvents or already used as flavors or fragrances. Although humans and the environment may be readily exposed little is known regarding their (eco)toxicological effects. In this study, the three potential biofuels ethyl levulinate (EL), 2-methyltetrahydrofuran (2-MTHF) and 2-methylfuran (2-MF) were investigated for their acute embryo toxicity and teratogenicity using the fish embryo toxicity (FET) test to identify unknown hazard potentials and to allow focusing further research on substances with low toxic potentials. In addition, two fossil fuels (diesel and gasoline) and an established biofuel (rapeseed oil methyl ester) were investigated as references. The FET test is widely accepted and used in (eco)toxicology. It was performed using the zebrafish Danio rerio, a model organism useful for the prediction of human teratogenicity. Testing revealed a higher acute toxicity for EL (LC{sub 50}: 83 mg/L) compared to 2-MTHF (LC{sub 50}: 2980 mg/L), 2-MF (LC{sub 50}: 405 mg/L) and water accommodated fractions of the reference fuels including gasoline (LC{sub 50}: 244 mg DOC/L). In addition, EL caused a statistically significant effect on head development resulting in elevated head lengths in zebrafish embryos. Results for EL reduce its likelihood of use as a biofuel since other substances with a lower toxic potential are available. The FET test applied at an early stage of development might be a useful tool to avoid further time and money requiring steps regarding research on unfavorable biofuels. - Highlights: • The demand for biofuels increases but their (eco)toxicological effects are unknown. • Acute fish embryo toxicity and teratogenicity of potential biofuels were evaluated. • Ethyl levulinate induced a higher acute toxicity compared to WAFs of gasoline. • Ethyl levulinate caused

  14. THE POTENTIAL OF BIOCHEMISTRY EDUCATION APPS IN THE FORMATIVE ASSESSMENT

    Directory of Open Access Journals (Sweden)

    M. L. Oliveira

    2015-08-01

    Full Text Available Introduction and objectives: Apps can be designed to provide usage data, and most of them do. These data are usually used to map users interests and to deliver more effective ads that are more likely to result in clicks, and sales. We have applied some of these metrics to understand how can it be used to map students’ behavior and to promote a formative assessment using educational software. The purpose of a formative assessment is to monitor student learning to provide ongoing feedback that can be used by instructors and students to improve the teaching and learning process. Thus, this modality aims to help both students and instructors to identify strengths and weaknesses that need to be developed. This study aimed to describe the potential of educational apps in the formative assessment process. Material and Methods: We have implemented assessment tools embedded in three apps (ARMET, The Cell and 3D Class used to teach: 1 Metabolic Pathways; 2 Scale of the cellular structures, and 3 Concepts from techniques used in a Biochemistry Lab course. The implemented tools allow to verify on what issues there were recurring mistakes, the total number of mistakes presented, which questions they most achieved, how long they took to perform the activity and other relevant information. Results and conclusion: Educational apps can provide transparent and coherent evaluation metrics to enable instructors to systematize more consistent criteria and indicators, reducing the subjectivity of the formative assessment process and the time spent for preparation, tabulation and analysis of assessment data. This approach allows instructors to understand better where students struggle, giving to them a more effective feedback. It also helps instructor to plan interventions to help students to perform better and to achieve the learning objectives.

  15. Deficiency in the mitochondrial apoptotic pathway reveals the toxic potential of autophagy under ER stress conditions.

    Science.gov (United States)

    Deegan, Shane; Saveljeva, Svetlana; Logue, Susan E; Pakos-Zebrucka, Karolina; Gupta, Sanjeev; Vandenabeele, Peter; Bertrand, Mathieu J M; Samali, Afshin

    2014-01-01

    Endoplasmic reticulum (ER) stress-induced cell death is normally associated with activation of the mitochondrial apoptotic pathway, which is characterized by CYCS (cytochrome c, somatic) release, apoptosome formation, and caspase activation, resulting in cell death. In this study, we demonstrate that under conditions of ER stress cells devoid of CASP9/caspase-9 or BAX and BAK1, and therefore defective in the mitochondrial apoptotic pathway, still undergo a delayed form of cell death associated with the activation of caspases, therefore revealing the existence of an alternative stress-induced caspase activation pathway. We identified CASP8/caspase-8 as the apical protease in this caspase cascade, and found that knockdown of either of the key autophagic genes, ATG5 or ATG7, impacted on CASP8 activation and cell death induction, highlighting the crucial role of autophagy in the activation of this novel ER stress-induced death pathway. In line with this, we identified a protein complex composed of ATG5, FADD, and pro-CASP8 whose assembly coincides with caspase activation and cell death induction. Together, our results reveal the toxic potential of autophagy in cells undergoing ER stress that are defective in the mitochondrial apoptotic pathway, and suggest a model in which the autophagosome functions as a platform facilitating pro-CASP8 activation. Chemoresistance, a common problem in the treatment of cancer, is frequently caused by the downregulation of key mitochondrial death effector proteins. Alternate stress-induced apoptotic pathways, such as the one described here, may become of particular relevance for tackling the problem of chemoresistance in cancer cells.

  16. Potential formation in axisymmetrized tandem mirror GAMMA 10

    International Nuclear Information System (INIS)

    Cho, T.; Ichimura, M.; Inutake, M.

    1985-01-01

    The paper reports experimental results on potential formation and end plugging in the axisymmetrized tandem mirror GAMMA 10. The plugging at both ends has been achieved by a combination of neutral beams and gyrotrons. The presence of a plug potential with a thermal barrier in an axisymmetric mirror has been confirmed by direct measurement of the axial potential profile. Enhancement of axial particle confinement has been observed during the end plugging. Non-ambipolar radial transport has been greatly reduced in the axisymmetrized magnetic configuration. The potentials measured by beam probes and end loss analysers are 0.7, 0.4 and 1.1 kV in the central, barrier and plug regions, respectively. Strong end plugging is observed when the central-cell density is higher than the densities in the plug and the barrier, and the plug density remains higher than the barrier density. The plug electron temperature is higher than the central temperature. Hot electrons forming a football-shaped profile have been stably produced in the axisymmetric mirror. The beta value and the fraction of the hot electrons reach up to 5% and 0.8, respectively. Central-cell ion-cyclotron resonance heating can sustain a stable plasma with higher density and ion temperature when resonance surfaces exist in both the anchor and the central cells. (author)

  17. Towards the prevention of potential aluminum toxic effects and an effective treatment for Alzheimer's disease.

    Science.gov (United States)

    Percy, Maire E; Kruck, Theo P A; Pogue, Aileen I; Lukiw, Walter J

    2011-11-01

    In 1991, treatment with low dose intramuscular desferrioxamine (DFO), a trivalent chelator that can remove excessive iron and/or aluminum from the body, was reported to slow the progression of Alzheimer's disease (AD) by a factor of two. Twenty years later this promising trial has not been followed up and why this treatment worked still is not clear. In this critical interdisciplinary review, we provide an overview of the complexities of AD and involvement of metal ions, and revisit the neglected DFO trial. We discuss research done by us and others that is helping to explain involvement of metal ion catalyzed production of reactive oxygen species in the pathogenesis of AD, and emerging strategies for inhibition of metal-ion toxicity. Highlighted are insights to be considered in the quests to prevent potentially toxic effects of aluminum toxicity and prevention and intervention in AD. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Glyphosate: environmental contamination, toxicity and potential risks to human health via food contamination.

    Science.gov (United States)

    Bai, Shahla Hosseini; Ogbourne, Steven M

    2016-10-01

    Glyphosate has been the most widely used herbicide during the past three decades. The US Environmental Protection Agency (EPA) classifies glyphosate as 'practically non-toxic and not an irritant' under the acute toxicity classification system. This classification is based primarily on toxicity data and due to its unique mode of action via a biochemical pathway that only exists in a small number of organisms that utilise the shikimic acid pathway to produce amino acids, most of which are green plants. This classification is supported by the majority of scientific literature on the toxic effects of glyphosate. However, in 2005, the Food and Agriculture Organisation (FAO) reported that glyphosate and its major metabolite, aminomethylphosphonic acid (AMPA), are of potential toxicological concern, mainly as a result of accumulation of residues in the food chain. The FAO further states that the dietary risk of glyphosate and AMPA is unlikely if the maximum daily intake of 1 mg kg(-1) body weight (bw) is not exceeded. Research has now established that glyphosate can persist in the environment, and therefore, assessments of the health risks associated with glyphosate are more complicated than suggested by acute toxicity data that relate primarily to accidental high-rate exposure. We have used recent literature to assess the possible risks associated with the presence of glyphosate residues in food and the environment.

  19. Dietary exposure to essential and potentially toxic elements for the population of Hanoi, Vietnam.

    Science.gov (United States)

    Marcussen, Helle; Jensen, Bodil H; Petersen, Annette; Holm, Peter E

    2013-01-01

    Knowledge of the dietary intake of essential and toxic elements in fast-developing Southeast Asian countries such as Vietnam is limited. Iron and Zn deficiency in Asia is a well-known problem and is partly due to rice constituting a major part of the diet. Dietary habits are changing and there is a need to build more knowledge so authorities can give dietary recommendations. The aim of this study was to determine the total dietary intake of essential and potentially toxic elements and to assess the nutritional quality and food safety risks of the average Hanoi diet. Twenty-two foods or food groups were identified and 14 samples of each food group were collected from markets and/or supermarkets in the period 2007-2009. Water spinach, water dropwort, watercress, water mimosa and pond fish are typically produced in wastewater-fed systems. Therefore, these samples were collected both at markets and from wastewater-fed production systems. The results showed little or no risk of toxic elements from the Hanoi diet in general. Further, element contributions from wastewater-fed products were low and does not seem to constitute a problem with respect to potentially toxic elements. A comparison of the average Hanoi dietary intake of essential elements to required intakes shows that the Hanoi diet is sufficient in most elements. However, the diet may be insufficient in Ca, Cr, Fe, K and possibly Zn for which dietary diversification of biofortification might provide solutions.

  20. Methodology for assessing thioarsenic formation potential in sulfidic landfill environments.

    Science.gov (United States)

    Zhang, Jianye; Kim, Hwidong; Townsend, Timothy

    2014-07-01

    Arsenic leaching and speciation in landfills, especially those with arsenic bearing waste and drywall disposal (such as construction and demolition (C&D) debris landfills), may be affected by high levels of sulfide through the formation of thioarsenic anions. A methodology using ion chromatography (IC) with a conductivity detector was developed for the assessment of thioarsenic formation potential in sulfidic landfill environments. Monothioarsenate (H2AsSO3(-)) and dithioarsenate (H2AsS2O2(-)) were confirmed in the IC fractions of thioarsenate synthesis mixture, consistent with previous literature results. However, the observation of AsSx(-) (x=5-8) in the supposed trithioarsenate (H2AsS3O(-)) and tetrathioarsenate (H2AsS4(-)) IC fractions suggested the presence of new arsenic polysulfide complexes. All thioarsenate anions, particularly trithioarsenate and tetrathioarsenate, were unstable upon air exposure. The method developed for thioarsenate analysis was validated and successfully used to analyze several landfill leachate samples. Thioarsenate anions were detected in the leachate of all of the C&D debris landfills tested, which accounted for approximately 8.5% of the total aqueous As in the leachate. Compared to arsenite or arsenate, thioarsenates have been reported in literature to have lower adsorption on iron oxide minerals. The presence of thioarsenates in C&D debris landfill leachate poses new concerns when evaluating the impact of arsenic mobilization in such environments. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Potential risks of metal toxicity in contaminated sediments of Deule river in Northern France

    Energy Technology Data Exchange (ETDEWEB)

    Lourino-Cabana, Beatriz; Lesven, Ludovic; Charriau, Adeline [Equipe de Chimie Analytique et Marine, Universite de Lille 1, FRE CNRS Geosystemes 3298, Bat. C8, 59655 Villeneuve d' Ascq (France); Billon, Gabriel, E-mail: gabriel.billon@univ-lille1.fr [Equipe de Chimie Analytique et Marine, Universite de Lille 1, FRE CNRS Geosystemes 3298, Bat. C8, 59655 Villeneuve d' Ascq (France); Ouddane, Baghdad [Equipe de Chimie Analytique et Marine, Universite de Lille 1, FRE CNRS Geosystemes 3298, Bat. C8, 59655 Villeneuve d' Ascq (France); Boughriet, Abdel [Universite Lille Nord de France, Rue de l' Universite, P.O. Box 819, 62408 Bethune (France)

    2011-02-28

    Research highlights: {yields} A historical environmental pollution is evidenced with reference to background levels. {yields} Sedimentary trace metals partitioning is examined under undisturbed conditions. {yields} Anoxia and diagenetic processes induce geochemical and mineralogical variabilities. {yields} Do metals present in particles and pore waters exhibit a potential toxicity risk? {yields} Behaviour of binding fractions contributes to trace metals scavenging. - Abstract: The aim of this paper was to evaluate the potential sediment cumulative damage and toxicity due to metal contamination in a polluted zone of Deule river (in northern France) from nearby two smelters. Metal-enrichment factors and geoaccumulation indices measured with sediment depth revealed that - compared to background levels either in local reference soils or in world rivers sediments/suspended particulate matter - Cd contributed to the highest pollution levels, followed by Zn, Pb and to a much lesser extent Cu and Ni. A comparison of the vertical distribution of AVS (acid volatile sulfides), SEM (simultaneously extracted metals), TMC (total metal concentrations), TOC (total organic carbon) and interstitial water-metal concentrations in the sediment allowed us to highlight the extent of toxicity caused by Cd, Pb, Zn, Ni and Cu and to raise the possibility of their association with certain geochemical phases. To assess the actual environmental impacts of these metals in Deule river, numerical sediment quality guidelines were further used in the present work. Sedimentary Pb, Zn, and Cd contents largely exceeded PEC (probable effect concentration) values reported as consensus-based sediment quality guidelines for freshwater ecosystems. As for risks of toxicity from pore waters, metal concentrations reached their maxima at the surficial layers of the sediment (1-3 cm) and IWCTU (Interstitial Water Criteria Toxicity Unit) observed for Pb and to a lesser extent Cd, violated the corresponding water

  2. Potential risks of metal toxicity in contaminated sediments of Deule river in Northern France

    International Nuclear Information System (INIS)

    Lourino-Cabana, Beatriz; Lesven, Ludovic; Charriau, Adeline; Billon, Gabriel; Ouddane, Baghdad; Boughriet, Abdel

    2011-01-01

    Research highlights: → A historical environmental pollution is evidenced with reference to background levels. → Sedimentary trace metals partitioning is examined under undisturbed conditions. → Anoxia and diagenetic processes induce geochemical and mineralogical variabilities. → Do metals present in particles and pore waters exhibit a potential toxicity risk? → Behaviour of binding fractions contributes to trace metals scavenging. - Abstract: The aim of this paper was to evaluate the potential sediment cumulative damage and toxicity due to metal contamination in a polluted zone of Deule river (in northern France) from nearby two smelters. Metal-enrichment factors and geoaccumulation indices measured with sediment depth revealed that - compared to background levels either in local reference soils or in world rivers sediments/suspended particulate matter - Cd contributed to the highest pollution levels, followed by Zn, Pb and to a much lesser extent Cu and Ni. A comparison of the vertical distribution of AVS (acid volatile sulfides), SEM (simultaneously extracted metals), TMC (total metal concentrations), TOC (total organic carbon) and interstitial water-metal concentrations in the sediment allowed us to highlight the extent of toxicity caused by Cd, Pb, Zn, Ni and Cu and to raise the possibility of their association with certain geochemical phases. To assess the actual environmental impacts of these metals in Deule river, numerical sediment quality guidelines were further used in the present work. Sedimentary Pb, Zn, and Cd contents largely exceeded PEC (probable effect concentration) values reported as consensus-based sediment quality guidelines for freshwater ecosystems. As for risks of toxicity from pore waters, metal concentrations reached their maxima at the surficial layers of the sediment (1-3 cm) and IWCTU (Interstitial Water Criteria Toxicity Unit) observed for Pb and to a lesser extent Cd, violated the corresponding water quality data recommended

  3. Phytochemical constituents, antioxidant activity and toxicity potential of Phlomis olivieri Benth.

    Directory of Open Access Journals (Sweden)

    M.R. Delnavazi

    2016-04-01

    Full Text Available Background and objectives: Phlomis olivieri Benth. (Lamiaceae is a medicinal plant widely distributed in Iran. In the present study, we have investigated the phytochemical constituents, antioxidant activity and general toxicity potential of the aerial parts of this species. Methods: Silica gel (normal and reversed phases and Sephadex LH-20 column chromatographies were used for isolation of compounds from methanol-soluble portion (MSP of the total extract obtained from P. olivieri aerial parts. The structures of isolated compounds were elucidated using 1H-NMR, 13C-NMR and UV spectral analyses. Antioxidant activity and general toxicity potential of MSP were also evaluated in DPPH free radical-scavenging assay and brine shrimp lethality test (BSLT, respectively. Results: One caffeoylquinic acid derivative, chlorogenic acid (1, one iridoid glycoside, ipolamiide (2, two phenylethanoid glycosides, phlinoside C (3 and verbascoside (5, along with two flavonoids, isoquercetin (4 and naringenin (6 were isolated and identified from MSP. The MSP exhibited considerable antioxidant activity in DPPH method (IC50; 50.4 ± 4.6 µg/mL, compared to BHT (IC50; 18.7 ± 2.1 µg/mL, without any toxic effect in BSLT at the highest tested dose (1000 µg/mL. Conclusion: the results of the present study introduce P. olivieri as a medicinal plant with valuable biological and pharmacological potentials.

  4. Triphenyl phosphate-induced developmental toxicity in zebrafish: Potential role of the retinoic acid receptor

    Energy Technology Data Exchange (ETDEWEB)

    Isales, Gregory M.; Hipszer, Rachel A.; Raftery, Tara D. [Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC (United States); Chen, Albert; Stapleton, Heather M. [Division of Environmental Sciences and Policy, Nicholas School of the Environment, Duke University, Durham, NC (United States); Volz, David C., E-mail: volz@mailbox.sc.edu [Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC (United States)

    2015-04-15

    Highlights: • Triphenyl phosphate-induced toxicity in zebrafish embryos is enhanced in the presence of a retinoic acid receptor antagonist. • Triphenyl phosphate uptake or metabolism within zebrafish embryos is not altered in the presence of a retinoic acid receptor antagonist. • Triphenyl phosphate decreases expression of cytochrome P450 26a1 in zebrafish embryos. • Triphenyl phosphate inhibits retinoic acid-induced activation of human retinoic acid receptors. - Abstract: Using zebrafish as a model, we previously reported that developmental exposure to triphenyl phosphate (TPP) – a high-production volume organophosphate-based flame retardant – results in dioxin-like cardiac looping impairments that are independent of the aryl hydrocarbon receptor. Using a pharmacologic approach, the objective of this study was to investigate the potential role of retinoic acid receptor (RAR) – a nuclear receptor that regulates vertebrate heart morphogenesis – in mediating TPP-induced developmental toxicity in zebrafish. We first revealed that static exposure of zebrafish from 5–72 h post-fertilization (hpf) to TPP in the presence of non-toxic concentrations of an RAR antagonist (BMS493) significantly enhanced TPP-induced toxicity (relative to TPP alone), even though identical non-toxic BMS493 concentrations mitigated retinoic acid (RA)-induced toxicity. BMS493-mediated enhancement of TPP toxicity was not a result of differential TPP uptake or metabolism, as internal embryonic doses of TPP and diphenyl phosphate (DPP) – a primary TPP metabolite – were not different in the presence or absence of BMS493. Using real-time PCR, we then quantified the relative change in expression of cytochrome P450 26a1 (cyp26a1) – a major target gene for RA-induced RAR activation in zebrafish – and found that RA and TPP exposure resulted in a ∼5-fold increase and decrease in cyp26a1 expression, respectively, relative to vehicle-exposed embryos. To address whether TPP may

  5. Study on the Potential Toxicity of a Thymoquinone-Rich Fraction Nanoemulsion in Sprague Dawley Tats

    Directory of Open Access Journals (Sweden)

    Maznah Ismail

    2013-06-01

    Full Text Available Toxicological studies constitute an essential part of the effort in developing an herbal medicine into a drug product. A newly developed thymoquinone-rich fraction nanoemulsion (TQRFNE has been prepared using a high pressure homogenizer. The purpose of this study was to investigate the potential acute toxicity of this nanoemulsion in Sprague Dawley rats. The acute toxicity studies were conducted as per the OECD guidelines 425, allowing for the use of test dose limit of 20 mL TQRFNE (containing 44.5 mg TQ/kg. TQRFNE and distilled water (DW as a control were administered orally to both sexes of rats on Day 0 and observed for 14 days. All the animals appeared normal, and healthy throughout the study. There was no observed mortality or any signs of toxicity during the experimental period. The effects of the TQRFNE and DW groups on general behavior, body weight, food and water consumption, relative organ weight, hematology, histopathology, and clinical biochemistry were measured. All the parameters measured were unaffected as compared to the control (DW group. The administration of 20 mL TQRFNE /kg was not toxic after an acute exposure.

  6. Potentially toxic concentrations of synthetic pyrethroids associated with low density residential land use

    Directory of Open Access Journals (Sweden)

    Stephen Marshall

    2016-11-01

    Full Text Available Trace organic compounds associated with human activity are now ubiquitous in the environment. As the population becomes more urbanised and the use of pesticides and person care products continues to increase, urban waterways are likely to receive higher loads of trace organic contaminants with unknown ecological consequences. To establish the extent of trace organic contamination in urban runoff, concentrations of emerging chemicals of concern were determined in sediments from 99 urban wetlands in and around Melbourne, Australia between February and April, 2015. As a preliminary estimation of potential risks to aquatic biota, we compared measured concentrations with thresholds for acute and chronic toxicity, and modelled toxic units as a function of demographic and land use trends. The synthetic pyrethroid insecticide bifenthrin was common and widespread, and frequently occurred at concentrations likely to cause toxicity to aquatic life. Personal care products DEET and triclosan were common and widely distributed, while the herbicides diuron and prometryn, and the fungicides pyrimethanil and trifloxystrobin occurred less frequently. Toxic unit modelling using random forests found complex and unexpected associations between urban land uses and trace organic concentrations. Synthetic pyrethroid insecticides were identified as emerging compounds of concern, particularly bifenthrin. In contrast with previous surveys, the highest bifenthrin concentrations were associated with lower housing and population density, implicating low-density residential land use in bifenthrin contamination. We discuss the implications for pesticide regulation and urban wetland management in a global context.

  7. In Vitro Protective Potentials of Annona muricata Leaf Extracts Against Sodium Arsenite-induced Toxicity.

    Science.gov (United States)

    George, Vazhappilly Cijo; Kumar, Devanga Ragupathi Naveen; Suresh, Palamadai Krishnan; Kumar, Rangasamy Ashok

    2015-01-01

    Sodium arsenite (NaAsO2) is a metalloid which is present widely in the environment and its chronic exposure can contribute to the induction of oxidative stress, resulting in disturbances in various metabolic functions including liver cell death. Hence, there is a need to develop drugs from natural sources, which can reduce arsenic toxicity. While there have been reports regarding the antioxidant and protective potentials of Annona muricataleaf extracts, our study is the first ofits kind to extend these findings by specifically evaluating its ability to render protection against sodium arsenite (NaAsO2) induced toxicity (10 μM) in WRL-68 (human hepatic cells) and human erythrocytes by employing XTT and haemolysis inhibition assays respectively. The methanolic extract exhibited higher activity than the aqueous extract in both assays. The results showed a dose-dependent decrease in arsenic toxicity in both WRL-68 cells and erythrocytes, suggesting the protective nature of Annona muricatato mitigate arsenic toxicity. Hence the bioactive extracts can further be scrutinized for the identification and characterization of their principal contributors.

  8. Hazard identification of contaminated sites. Ranking potential toxicity of organic sediment extracts in crustacean and fish

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, J.; Sundberg, H.; Aakerman, G.; Grunder, K.; Eklund, B.; Breitholtz, M. [Dept. of Applied Environmental Science (ITM), Stockholm Univ. (Sweden)

    2008-09-15

    Background, aim, and scope: It is well known that contaminated sediments represent a potential long-term source of pollutants to the aquatic environment. To protect human and ecosystem health, it is becoming common to remediate contaminated sites. However, the great cost associated with, e.g., dredging in combination with the large numbers of contaminated sites makes it crucial to pinpoint those sites that are in greatest need of remediation. In most European countries, this prioritization process has almost exclusively been based on chemical analyses of known substances; only seldom toxicity data has been considered. The main objective of the current study was therefore to develop a tool for hazard identification of sediment by ranking potential toxicity of organic sediment extracts in a crustacean and a fish. A secondary objective was to investigate the difference in potential toxicity between compounds with different polarities. Materials and methods Early life stages of the crustacean Nitocra spinipes and the fish Oncorhynchus mykiss, which represent organisms from different trophic levels (primary and secondary consumer) and with different routes of exposure (i.e. ingestion through food, diffusive uptake, and maternal transfer), were exposed to hexane and acetone fractions (semi-polar compounds) of sediment from five locations, ranging from heavily to low contaminated. Preliminary tests showed that the extracts were non-bioavailable to the crustacean when exposed via water, and the extracts were therefore loaded on silica gel. Rainbow trout embryos were exposed using nano-injection technique. Results and discussion Clear concentration-response relationships of both mortality and larval development were observed in all tests with N. spinipes. Also for rainbow trout, the observed effects (e.g., abnormality, hemorrhage, asymmetric yolk sac) followed a dose-related pattern. Interestingly, our results indicate that some of the locations contained toxic semi

  9. Acute marine sediment toxicity: a potential new test with the amphipod Gammarus locusta.

    Science.gov (United States)

    Costa, F O; Correia, A D; Costa, M H

    1998-01-01

    Although amphipod toxicity tests have been successfully used in the United States to assess coastal sediment toxicity, few tests have been developed with European species. The authors have been working with the amphipod Gammarus locusta, a widely spread species along European coastal areas that is particularly abundant in the Portuguese Sado estuary. This amphipod fulfills the most important requirements of a test species. It can be easily reproduced in laboratory and it is tolerant to a broad range of sediment types. A series of tests demonstrated its sensitivity to copper and gamma-hexachlorocyclohexane (lindane) in the sediment (LC50 = 6.8 mg Cu/dry kg, 0.9% total volatile solids; LC50 = 60.5 micrograms HCH/dry kg, 2% total volatile solids) and to some heavily contaminated field sediments. After assessment of the species sensitivity to several noncontaminant variables, an experimental protocol was designed to conduct acute sediment toxicity tests that are briefly described. Proposed is a 10-day static toxicity test at 15 degrees C and 33-34/1000 salinity, with laboratory-produced juveniles and mortality as the endpoint. General assay performance is identical to the American Society for Testing and Materials (ASTM) standard for sediment toxicity tests with marine and estuarine amphipods. The results previously obtained revealed a strong potential for this amphipod to be used in toxicological testing. Considering the wide geographic distribution of this species and its amenability for culturing, it may be an alternative or complementary test for ecotoxicological studies in other European coastal systems where the existing tests cannot be applied or do not offer a definitive solution.

  10. Influence of potentially confounding factors on sea urchin porewater toxicity tests

    Science.gov (United States)

    Carr, R.S.; Biedenbach, J.M.; Nipper, M.

    2006-01-01

    The influence of potentially confounding factors has been identified as a concern for interpreting sea urchin porewater toxicity test data. The results from >40 sediment-quality assessment surveys using early-life stages of the sea urchin Arbacia punctulata were compiled and examined to determine acceptable ranges of natural variables such as pH, ammonia, and dissolved organic carbon on the fertilization and embryological development endpoints. In addition, laboratory experiments were also conducted with A. punctulata and compared with information from the literature. Pore water with pH as low as 6.9 is an unlikely contributor to toxicity for the fertilization and embryological development tests with A. punctulata. Other species of sea urchin have narrower pH tolerance ranges. Ammonia is rarely a contributing factor in pore water toxicity tests using the fertilization endpoint, but the embryological development endpoint may be influenced by ammonia concentrations commonly found in porewater samples. Therefore, ammonia needs to be considered when interpreting results for the embryological development test. Humic acid does not affect sea urchin fertilization at saturation concentrations, but it could have an effect on the embryological development endpoint at near-saturation concentrations. There was no correlation between sediment total organic carbon concentrations and porewater dissolved organic carbon concentrations. Because of the potential for many varying substances to activate parthenogenesis in sea urchin eggs, it is recommended that a no-sperm control be included with every fertilization test treatment. ?? 2006 Springer Science+Business Media, Inc.

  11. From streets to streams: assessing the toxicity potential of urban sediment by particle size

    Science.gov (United States)

    Corsi, Steven R.; Selbig, William R.; Roger T. Bannerman,; ,

    2013-01-01

    Urban sediment can act as a transport mechanism for a variety of pollutants to move towards a receiving water body. The concentrations of these pollutants oftentimes exceed levels that are toxic to aquatic organisms. Many treatment structures are designed to capture coarse sediment but do not work well to similarly capture the fines. This study measured concentrations of select trace metals and PAHs in both the silt and sand fractions of urban sediment from four sources: stormwater bed, stormwater suspended, street dirt, and streambed. Concentrations were used to assess the toxic potential of sediment based on published sediment quality guidelines. All sources of sediment showed some level of toxic potential with stormwater bed sediment the highest followed by stormwater suspended, street dirt, and streambed. Both metal and PAH concentration distributions were highly correlated between the four sampling locations suggesting the presence of one or perhaps only a few sources of these pollutants which remain persistent as sediment is transported from street to stream. Comparison to other forms of combustion- and vehicle-related sources of PAHs revealed coal tar sealants to have the strongest correlation, in both the silt and sand fractions, at all four sampling sites. This information is important for environmental managers when selecting the most appropriate Best Management Practice (BMP) as a way to mitigate pollution conveyed in urban stormwater from source to sink.

  12. Dietary exposure to essential and potentially toxic elements for the population of Hanoi, Vietnam

    DEFF Research Database (Denmark)

    Marcussen, H.; Jensen, Bodil Hamborg; Petersen, Annette

    2013-01-01

    and there is a need to build more knowledge so that authorities can give dietary recommendations. The aim of this study was to determine the total dietary intake of essential and potentially toxic elements and to assess the nutritional quality and food safety risks of the average Hanoi diet. 22 foods or food groups......Knowledge of the dietary intake of essential and toxic elements in fast-developing Southeast Asian countries such as Vietnam is limited. Iron and Zn deficiency in Asia is a well-known problem and is partly due to rice constituting a major part of the diet. Dietary habits are changing...... were identified and 14 samples of each food group were collected from markets and/or supermarkets in the period 2007-2009. Water spinach, water dropwort, watercress, water mimosa and pond fish are typically produced in wastewater-fed systems. Therefore, these samples were collected both at markets...

  13. Removal potential of toxic 2378-substituted PCDD/F from incinerator flue gases by waste-derived activated carbons

    International Nuclear Information System (INIS)

    Hajizadeh, Yaghoub; Onwudili, Jude A.; Williams, Paul T.

    2011-01-01

    The application of activated carbons has become a commonly used emission control protocol for the removal or adsorption of persistent organic pollutants from the flue gas streams of waste incinerators. In this study, the 2378-substituted PCDD/F removal efficiency of three types of activated carbons derived from the pyrolysis of refuse derived fuel, textile waste and scrap tyre was investigated and compared with that of a commercial carbon. Experiments were carried out in a laboratory scale fixed-bed reactor under a simulated flue gas at 275 deg. C with a reaction period of four days. The PCDD/F in the solid matrices and exhaust gas, were analyzed using gas chromatography coupled with a triple quadrupole mass spectrometer. In the absence of activated carbon adsorbent, there was a significant increase in the concentration of toxic PCDD/F produced in the reacted flyash, reaching up to 6.6 times higher than in the raw flyash. In addition, there was a substantial release of PCDD/F into the gas phase, which was found in the flue gas trapping system. By application of the different commercial, refuse derived fuel, textile and tyre activated carbons the total PCDD/F toxic equivalent removal efficiencies in the exhaust gas stream were 58%, 57%, 64% and 52%, respectively. In general, the removal of the PCDDs was much higher with an average of 85% compared to PCDFs at 41%. Analysis of the reacted activated carbons showed that there was some formation of PCDD/F, for instance, a total of 60.6 μg I-TEQ kg -1 toxic PCDD/F was formed in the refuse derived fuel activated carbon compared to 34 μg I-TEQ kg -1 in the commercial activated carbon. The activated carbons derived from the pyrolysis of waste, therefore, showed good potential as a control material for PCDD/F emissions in waste incinerator flue gases.

  14. Nanoscale copper in the soil–plant system – toxicity and underlying potential mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Anjum, Naser A., E-mail: anjum@ua.pt [CESAM-Centre for Environmental and Marine Studies & Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Adam, Vojtech [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno (Czech Republic); Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno (Czech Republic); Kizek, Rene [Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno (Czech Republic); Duarte, Armando C.; Pereira, Eduarda [CESAM-Centre for Environmental and Marine Studies & Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); Iqbal, Muhammad [Department of Botany, Faculty of Science, Hamdard University, New Delhi 110062 (India); Lukatkin, Alexander S. [Department of Botany, Plant Physiology and Ecology, N.P. Ogarev Mordovia State University, Bolshevistskaja Str., 68. Saransk 430005 (Russian Federation); Ahmad, Iqbal, E-mail: ahmadr@ua.pt [CESAM-Centre for Environmental and Marine Studies & Department of Chemistry, University of Aveiro, 3810-193 Aveiro (Portugal); CESAM-Centre for Environmental and Marine Studies & Department of Biology, University of Aveiro, 3810-193 Aveiro (Portugal)

    2015-04-15

    Nanoscale copper particles (nano-Cu) are used in many antimicrobial formulations and products for their antimicrobial activity. They may enter deliberately and/or accidentally into terrestrial environments including soils. Being the major ‘eco-receptors’ of nanoscale particles in the terrestrial ecosystem, soil–microbiota and plants (the soil–plant system) have been used as a model to dissect the potential impact of these particles on the environmental and human health. In the soil–plant system, the plant can be an indirect non-target organism of the soil-associated nano-Cu that may in turn affect plant-based products and their consumers. By all accounts, information pertaining to nano-Cu toxicity and the underlying potential mechanisms in the soil–plant system remains scanty, deficient and little discussed. Therefore, based on some recent reports from (bio)chemical, molecular and genetic studies of nano-Cu versus soil–plant system, this article: (i) overviews the status, chemistry and toxicity of nano-Cu in soil and plants, (ii) discusses critically the poorly understood potential mechanisms of nano-Cu toxicity and tolerance both in soil–microbiota and plants, and (iii) proposes future research directions. It appears from studies hitherto made that the uncontrolled generation and inefficient metabolism of reactive oxygen species through different reactions are the major factors underpinning the overall nano-Cu consequences in both the systems. However, it is not clear whether the nano-Cu or the ion released from it is the cause of the toxicity. We advocate to intensify the multi-approach studies focused at a complete characterization of the nano-Cu, its toxicity (during life cycles of the least-explored soil–microbiota and plants), and behavior in an environmentally relevant terrestrial exposure setting. Such studies may help to obtain a deeper insight into nano-Cu actions and address adequately the nano-Cu-associated safety concerns in the

  15. Bioaccessibility and Speciation of Potential Toxicants in Some Geogenic Sources of Atmospheric Particulate Matter

    Science.gov (United States)

    Morman, S. A.; Wolf, R. E.; Plumlee, G.; Reynolds, R. L.

    2008-12-01

    The correlation of exposure to particulate matter (PM) and increased morbidity and mortality was established in the 1970's. Research focused on elucidating mechanisms of action (i.e. particle size, composition, and biodurability), has generally examined anthropogenic sources such as solid or liquid combustion byproducts of fossil fuels, byproducts from the smelting of metal ores, and commercial/industrial mineral dusts (asbestos, crystalline silica. metal dusts). While many studies exist on agricultural exposures to inorganic dust, far fewer have examined health issues related to particulate matter contributions from rural, non-agricultural dusts or other geogenic sources. Geogenic PM (produced by natural processes such as volcanic ash, volcanic fog (vog), dusts from dry lakes or glacial deposits, smoke and windborne ash from wildfires, and dusts containing various soil pathogens) and geoanthropogenic PM (produced from natural sources by processes that are modified or enhanced by human activities such as dusts from lakebeds dried by human removal of water, dusts produced from areas that have undergone desertification as a result of human practices etc.) are increasingly recognized as potential agents of toxicity and disease, via both environmental and occupational exposures. Surface sediment on some dry lake beds may contribute significant amounts of mineral dusts to the atmospheric load. For example, Owens Lake (a dry lake in southern California) has been a major source of PM10 (particulate matter less than 10 micrometers) dust in the United States. Dusts from dry and drying saline lakes may contain high concentrations of metals, such as arsenic, with known human health toxicity. Wildfires, consuming over nine million acres in 2007, also contribute significant amounts of particulate matter in addition to their other hazards. Designed to estimate the bioaccessibility of metals in soils, dusts and other environmental materials by measuring the reactivity of the

  16. Nanoscale copper in the soil–plant system – toxicity and underlying potential mechanisms

    International Nuclear Information System (INIS)

    Anjum, Naser A.; Adam, Vojtech; Kizek, Rene; Duarte, Armando C.; Pereira, Eduarda; Iqbal, Muhammad; Lukatkin, Alexander S.; Ahmad, Iqbal

    2015-01-01

    Nanoscale copper particles (nano-Cu) are used in many antimicrobial formulations and products for their antimicrobial activity. They may enter deliberately and/or accidentally into terrestrial environments including soils. Being the major ‘eco-receptors’ of nanoscale particles in the terrestrial ecosystem, soil–microbiota and plants (the soil–plant system) have been used as a model to dissect the potential impact of these particles on the environmental and human health. In the soil–plant system, the plant can be an indirect non-target organism of the soil-associated nano-Cu that may in turn affect plant-based products and their consumers. By all accounts, information pertaining to nano-Cu toxicity and the underlying potential mechanisms in the soil–plant system remains scanty, deficient and little discussed. Therefore, based on some recent reports from (bio)chemical, molecular and genetic studies of nano-Cu versus soil–plant system, this article: (i) overviews the status, chemistry and toxicity of nano-Cu in soil and plants, (ii) discusses critically the poorly understood potential mechanisms of nano-Cu toxicity and tolerance both in soil–microbiota and plants, and (iii) proposes future research directions. It appears from studies hitherto made that the uncontrolled generation and inefficient metabolism of reactive oxygen species through different reactions are the major factors underpinning the overall nano-Cu consequences in both the systems. However, it is not clear whether the nano-Cu or the ion released from it is the cause of the toxicity. We advocate to intensify the multi-approach studies focused at a complete characterization of the nano-Cu, its toxicity (during life cycles of the least-explored soil–microbiota and plants), and behavior in an environmentally relevant terrestrial exposure setting. Such studies may help to obtain a deeper insight into nano-Cu actions and address adequately the nano-Cu-associated safety concerns in the

  17. Potentially toxic elements in foodcrops: Triticum aestivum L., Zea mays L.

    Science.gov (United States)

    Bini, Claudio; Fontana, Silvia; Squizzato, Stefania; Minello, Fabiola; Fornasier, Flavio; Wahsha, Mohammad

    2013-04-01

    Soil is the basis of the ecosystems and of our system of food production. Crops can uptake heavy metals and potentially toxic elements from the soil and store them in the roots or translocate them to the aerial parts. Excessive content of these elements in edible parts can produce toxic effects and, through the food chain and food consumption, result in a potential hazard for human health. In this study soils and plants (spring wheat, Triticum aestivum L. and maize, Zea mays L.) from a tannery district in North-East Italy were analyzed to determine pedological characters, soil microbial indicators and the content of some major and micro-nutrients and potentially toxic elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, P, Pb, S, Zn, V). The soils of the area are moderately polluted; Cr is the most important inorganic contaminant, followed by Ni, Cu and V. Factor analysis evidenced that the contaminants are in part anthropogenic and in part geogenic. Major anthropogenic origin was detected for Cr, Ni (from industrial activities), Zn, Cu, Cd (from agriculture practices). Biological Absorption Coefficient (BAC) from soil to plant roots and Translocation factor (TF) within the plant were calculated; major nutrients (K, P, S) and some micronutrients (Cu, Zn, Mg, Mn) are easily absorbed and translocated, whilst other nutrients (Ca, Fe) and potentially toxic elements or micronutrients (Al, Cd, Cr, Ni, Pb, V) are not accumulated in the seeds of the two considered species. However, the two edible species proved differently able to absorb and translocate elements, and this suggests to consider separately every species as potential PHEs transporter to the food chain and to humans. Cr concentrations in seeds and other aerial parts (stem and leaves) of the examined plants are higher than the values found for the same species and for other cereals grown on unpolluted soils. Comparing the Cr levels in edible parts with recommended dietary intake, besides other possible Cr sources

  18. Paraquat Toxicity on Root Nodule Formation on Macroptiliuma Tropurpureum Urb. and Its Corelation with Population of Rhizobium SP.

    OpenAIRE

    Martani, Erni; Margino, Sebastian; Magdalena, Medhina

    2004-01-01

    This study was designed to investigate the paraquat toxicity toward root nodulation by Rhizobium on Macroptilium atropurpureum as an indicator plant. The legume was grown in Thornton medium treated with several concentrations of paraquat and inoculated with R.japonicum 143 (Rj-143) or Rhizobium sp. C-1.1. These bacteria represent cross-inoculation of soybean and cover-crops legumes, respectively. Nodule formation and Rhizobium population were measured periodically. At the end of planting time...

  19. Photodecomposition of iodinated contrast media and subsequent formation of toxic iodinated moieties during final disinfection with chlorinated oxidants.

    Science.gov (United States)

    Allard, Sébastien; Criquet, Justine; Prunier, Anaïs; Falantin, Cécilia; Le Person, Annaïg; Yat-Man Tang, Janet; Croué, Jean-Philippe

    2016-10-15

    tested. Both oxidant poorly degraded the ICM and a higher formation of I-DBPs was observed for the chloramination experiments compared to the chlorination experiment. Results from toxicity testing showed that the photodegradation products of IOP are toxic and confirmed that the formation of I-DBPs leads to higher toxicity. Therefore, for the experiment with HOCl where iodate are formed the toxicity was lower than for the experiments with NH2Cl where a high formation of I-DBPs was observed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Pharmacophore modeling and in silico toxicity assessment of potential anticancer agents from African medicinal plants.

    Science.gov (United States)

    Ntie-Kang, Fidele; Simoben, Conrad Veranso; Karaman, Berin; Ngwa, Valery Fuh; Judson, Philip Neville; Sippl, Wolfgang; Mbaze, Luc Meva'a

    2016-01-01

    Molecular modeling has been employed in the search for lead compounds of chemotherapy to fight cancer. In this study, pharmacophore models have been generated and validated for use in virtual screening protocols for eight known anticancer drug targets, including tyrosine kinase, protein kinase B β, cyclin-dependent kinase, protein farnesyltransferase, human protein kinase, glycogen synthase kinase, and indoleamine 2,3-dioxygenase 1. Pharmacophore models were validated through receiver operating characteristic and Güner-Henry scoring methods, indicating that several of the models generated could be useful for the identification of potential anticancer agents from natural product databases. The validated pharmacophore models were used as three-dimensional search queries for virtual screening of the newly developed AfroCancer database (~400 compounds from African medicinal plants), along with the Naturally Occurring Plant-based Anticancer Compound-Activity-Target dataset (comprising ~1,500 published naturally occurring plant-based compounds from around the world). Additionally, an in silico assessment of toxicity of the two datasets was carried out by the use of 88 toxicity end points predicted by the Lhasa's expert knowledge-based system (Derek), showing that only an insignificant proportion of the promising anticancer agents would be likely showing high toxicity profiles. A diversity study of the two datasets, carried out using the analysis of principal components from the most important physicochemical properties often used to access drug-likeness of compound datasets, showed that the two datasets do not occupy the same chemical space.

  1. Potential of Annona muricata L. seed oil: phytochemical and nutritional characterization associated with non-toxicity

    Directory of Open Access Journals (Sweden)

    L. C. Pinto

    2018-03-01

    Full Text Available The aim of this study was to evaluate the nutritional quality, phenolic compounds, fatty acid and antioxidant activity in vitro as well as a toxicological screening of A. muricata seed oil in vivo. The chemical composition and quantification of phenolic compounds were determined by the Adolfo Lutz Institute normative. The antioxidant activity was evaluated by DPPH, FRAP and ABTS methods. The oil was extracted by chloroform/ methanol and precipitated crude (AmPtO and supernatant oils (AmSO were obtained. The fatty acid profile was evaluated by gas chromatography and total compounds by HPLC-DAD. BALB/C mice received AmPtO and AmSO (0.5 and 1.0mL·Kg-1 for 14 days. Toxicity parameters were assessed. The major fatty acids in the oil were oleic (39.2% and linoleic (33%. HPLC-DAD suggested the presence of acetogenins (annonacin: 595 [M-H]-, with a greater presence in AmPtO. The AmPtO group showed toxicity, which may be related to the acetogenin content in AmPtO. The AmSO group showed no toxicity and this oil has potential for food or medicinal use.

  2. Depth Profiling (ICP-MS Study of Toxic Metal Buildup in Concrete Matrices: Potential Environmental Impact

    Directory of Open Access Journals (Sweden)

    Ghada Bassioni

    2010-10-01

    Full Text Available This paper explores the potential of concrete material to accumulate toxic trace elements using ablative laser technology (ICP-MS. Concrete existing in offshore structures submerged in seawater acts as a sink for hazardous metals, which could be gradually released into the ocean creating pollution and anoxic conditions for marine life. Ablative laser technology is a valuable tool for depth profiling concrete to evaluate the distribution of toxic metals and locate internal areas where such metals accumulate. Upon rapid degradation of concrete these “hotspots” could be suddenly released, thus posing a distinct threat to aquatic life. Our work simulated offshore drilling conditions by immersing concrete blocks in seawater and investigating accumulated toxic trace metals (As, Be, Cd, Hg, Os, Pb in cored samples by laser ablation. The experimental results showed distinct inhomogeneity in metal distribution. The data suggest that conditions within the concrete structure are favorable for random metal accumulation at certain points. The exact mechanism for this behavior is not clear at this stage and has considerable scope for extended research including modeling and remedial studies.

  3. Degradation study of pesticides by direct photolysis - Structural characterization and potential toxicity of photo products

    International Nuclear Information System (INIS)

    Rifai, A.

    2013-01-01

    Pesticides belong to the large family of organic pollutants. In general, they are intended to fight against crop pests. Distribution of pesticides in nature creates pollution in DIFFERENT compartments of the biosphere (water, soil and air) and can induce acute toxic effects on human beings of the terrestrial and aquatic living biomass. It is now shown that some pesticides are endocrine disruptors and are particularly carcinogenic and mutagenic effects in humans. Pesticides can undergo various processes of transformation in the natural life cycle (biodegradation, volatilization, solar radiation ...) or following applied in the sectors of natural water purification and treatment stations sewage treatment. The presence of degradation products of pesticides in our environment is even more alarming that their structures and potential toxicities generally unknown. Molecules belonging to two families of pesticides were selected for this study: herbicides, represented by metolachlor, and fungicides represented by procymidone, pyrimethanil and boscalid. The first part of the thesis focused on the development of an analytical strategy to characterize the structures of compounds from degradation by photolysis of pesticides. The second part focused on estimating the toxicity of degradation products using a test database in silico. Identification of degradation products was achieved through two complementary analysis techniques: the gas chromatography coupled to a mass spectrometer ''multi-stage'' (GC-MSn) and liquid chromatography coupled to a tandem mass spectrometer (LC-MS/MS). The estimation of the toxicity of the degradation products was performed using the TEST program QSAR recently developed to try to predict the toxicity of molecules. The strategy of the structural elucidation of degradation products of pesticides studied is based on studying of the mechanisms of fragmentation of parent molecules of the degradation products. The molar mass of parent

  4. Probenecid potentiates MPTP/MPP+ toxicity by interference with cellular energy metabolism.

    Science.gov (United States)

    Alvarez-Fischer, Daniel; Noelker, Carmen; Grünewald, Anne; Vulinović, Franca; Guerreiro, Serge; Fuchs, Julia; Lu, Lixia; Lombès, Anne; Hirsch, Etienne C; Oertel, Wolfgang H; Michel, Patrick P; Hartmann, Andreas

    2013-12-01

    The uricosuric agent probenecid is co-administered with the dopaminergic neurotoxin MPTP to produce a chronic mouse model of Parkinson's disease. It has been proposed that probenecid serves to elevate concentrations of MPTP in the brain by reducing renal elimination of the toxin. However, this mechanism has never been formally demonstrated to date and is questioned by our previous data showing that intracerebral concentrations of MPP(+), the active metabolite of MPTP, are not modified by co-injection of probenecid. In this study, we investigated the potentiating effects of probenecid in vivo and in vitro arguing against the possibility of altered metabolism or impaired renal elimination of MPTP. We find that probenecid (i) is toxic in itself to several neuronal populations apart from dopaminergic neurons, and (ii) that it also potentiates the effects of other mitochondrial complex I inhibitors such as rotenone. On a mechanistic level, we show that probenecid is able to lower intracellular ATP concentrations and that its toxic action on neuronal cells can be reversed by extracellular ATP. Probenecid can potentiate the effect of mitochondrial toxins due to its impact on ATP metabolism and could therefore be useful to model atypical parkinsonian syndromes. © 2013 International Society for Neurochemistry.

  5. Leaching of the potentially toxic pollutants from composites based on waste raw material

    Directory of Open Access Journals (Sweden)

    Terzić Anja

    2012-01-01

    Full Text Available The disposal of the fly ash generated in coal based power-plants may pose a significant risk to the environment due to the possible leaching of hazardous pollutants, such as toxic metals. Also, there is a risk of leaching even when fly ash is built-in the construction composites. Fly ashes from various landfills were applied in several composite samples (mortar, concrete and brick without any physical or thermal pre-treatment. The leachability of the potentially toxic pollutants from the fly ash based products was investigated. The leaching behavior and potential environmental impact of the 11 potentially hazardous elements was tracked: Pb, Cd, Zn, Cu, Ni, Cr, Hg, As, Ba, Sb and Se. A detailed study of physico-chemical characteristics of the fly ash, with accent on trace elements and the chemical composition investigation is included. Physico/chemical properties of fly ash were investigated by means of X-ray fluorescence, differential thermal analysis and X-ray diffraction methods. Scanning electron microscope was used in microstructural analysis. The results show that most of the elements are more easily leachable from the fly ash in comparison with the fly ash based composites. The leaching of investigated pollutants is within allowed range thus investigated fly ashes can be reused in construction materials production.

  6. A simple scheme to determine potential aquatic metal toxicity from mining wastes

    Science.gov (United States)

    Wildeman, T.R.; Smith, K.S.; Ranville, J.F.

    2007-01-01

    A decision tree (mining waste decision tree) that uses simple physical and chemical tests has been developed to determine whether effluent from mine waste material poses a potential toxicity threat to the aquatic environment. For the chemical portion of the tree, leaching tests developed by the United States Geological Survey, the Colorado Division of Minerals and Geology (Denver, CO), and a modified 1311 toxicity characteristic leaching procedure (TCLP) test of the United States Environmental Protection Agency have been extensively used as a surrogate for readily available metals that can be released into the environment from mining wastes. To assist in the assessment, element concentration pattern graphs (ECPG) are produced that compare concentrations of selected groups of elements from the three leachates and any water associated with the mining waste. The MWDT makes a distinction between leachates or waters with pH less than or greater than 5. Generally, when the pH values are below 5, the ECPG of the solutions are quite similar, and potential aquatic toxicity from cationic metals, such as Pb, Cu, Zn, Cd, and Al, is assumed. Below pH 5, these metals are mostly dissolved, generally are not complexed with organic or inorganic ligands, and hence are more bioavailable. Furthermore, there is virtually no carbonate alkalinity at pH less than 5. All of these factors promote metal toxicity to aquatic organisms. On the other hand, when the pH value of the water or the leachates is above 5, the ECPG from the solutions are variable, and inferred aquatic toxicity depends on factors in addition to the metals released from the leaching tests. Hence, leachates and waters with pH above 5 warrant further examination of their chemical composition. Physical ranking criteria provide additional information, particularly in areas where waste piles exhibit similar chemical rankings. Rankings from physical and chemical criteria generally are not correlated. Examples of how this

  7. Quantitative analysis of potentially toxic metals in alginates for dental use

    Directory of Open Access Journals (Sweden)

    A. S. BRAGA

    2009-01-01

    Full Text Available

    Alginate is one the materials most employed in practice to make dental impressions. Substances like zinc, cadmium and lead silicate, which are included in several alginate brands with the aim of improving their physical, chemical and mechanical properties, are a source of serious concern as regards their toxicity. The most serious chronic effect of oral exposure to cadmium is renal toxicity. Assimilation of lead has deleterious effects on the gastrointestinal tract, hematopoietic system, cardiovascular system, central and peripheral nervous systems, kidneys, immune system, and reproductive system. Chronic oral exposures to zinc have resulted in hypochromic and microcyte anemia in some individuals. The aim of the present study was to measure the cadmium, lead and zinc contents of seven brands of alginate for dental use on sale in Brazil. The samples were weighed and placed in the Teflon cups of a closedsystem microwave oven. Aqua regia (4mL concentrated HCl:HNO3, 3:1 v/v and hydrofluoric acid (2mL concentrated HF were added to the samples, which were then subjected to heating. The samples were then cooled to room temperature and diluted to 25 mL in deionized water in a volumetric glass flask. The samples were diluted in duplicate and analyzed against a reagent blank. The analyses were performed in an atomic absorption flame spectrophotometer. Neither lead nor cadmium was detected. Zinc contents ranged from 0.001% to 1.36% by weight. The alginates exhibited low contents of the metals under study and gave no cause for concern regarding toxicity; even so, it is advisable to monitor potentially toxic materials continually and to analyze their plasmatic levels in the professionals working with them. Keywords: Cadmium, lead, zinc, alginates, intoxication, irreversible hydrocolloid.

  8. Phytochemical constituents, antioxidant activity and toxicity potential of the essential oil from Ferula gummosa Boiss. roots

    Directory of Open Access Journals (Sweden)

    T. Saadattalab

    2017-11-01

    Full Text Available Background and objectives: Ferula gummosa Boiss. (Umbelliferae is a popular medicinal plant, which is known mostly for therapeutic uses of its oleo-gum-resin (Barijeh in Persian. In the present study, the essential oil of F. gummosa roots was investigated for its phytochemical constituents, antioxidant activity and toxicity potential. Methods: Phytochemical constituents of the essential oil (extracted by hydrodistillation method were analyzed using GC-MS. Antioxidant and toxicity properties of the oil were also evaluated in DPPH free radical-scavenging assay and brine shrimp lethality test, respectively. Results: Forty-two compounds, representing 87.7% of total oil, were identified by GC-MS analysis of the plant roots oil. The essential oil was characterized by a high concentration of monoterpene hydrocarbons (55.9%, mainly β-pinene (33.2%, β-phellandrene (8.0% and α-pinene (6.9%. In DPPH free radical-scavenging assay, the oil sample did not demonstrate any activity at the highest tested concentration (1.0 mg/mL. However, it was found very toxic in brine shrimp lethality test with LD50 value of 2.4 µg/mL. Conclusion: The results of this study introduced the F. gummosa roots oil as a source of monoterpene hydrocarbons, especially β-pinene. Considering the high yield of essential oil extraction (12.1% v/w, these compounds may be involved in anticonvulsant, antinociceptive and anti-inflammatory properties of F. gummosa root. Moreover, considerable toxicity of the root oil highlights it as an appropriate candidate for further mechanistic toxicological studies.

  9. [The birth of nanobiotechnologies: new nanomaterials, potential uses, toxic effects and implications for public health].

    Science.gov (United States)

    Petrinca, Anna Rita; Pietroiusti, Antonio; Argentin, Gabriella; Cicchetti, Rosadele; Donia, Domenica; Gabrieli, Rosanna; Vignoli, Isabella; Magrini, Andrea; Divizia, Maurizio

    2009-01-01

    Nanotechnologies hold considerable promise of advances in many sectors especially the biomedical field, since the materials used are of the appropriate dimensions to interact with important biological matter such as proteins, DNA and viruses. In this field the use of nanotechnologies will probably be second in importance only to biotechnologies. However many characteristics of nanomaterials that make them so promising from a technological point of view may also lead to negative effects on the environment and human health. It is important therefore that the environmental and work-related exposure effects to these materials be evaluated. In this article the potential uses, toxic effects and public health implications of nanobiotechnologies are discussed.

  10. Composition, distribution, and potential toxicity of organochlorine mixtures in bed sediments of streams

    Science.gov (United States)

    Phillips, Patrick J.; Nowell, Lisa H.; Gilliom, Robert J.; Nakagaki, Naomi; Murray, Karen; VanAlstyne, Carolyn

    2010-01-01

    Mixtures of organochlorine compounds have the potential for additive or interactive toxicity to organisms exposed in the stream. This study uses a variety of methods to identify mixtures and a modified concentration-addition approach to estimate their potential toxicity at 845 stream sites across the United States sampled between 1992 and 2001 for organochlorine pesticides and polychlorinated biphenyls (PCBs) in bed sediment. Principal-component (PC) analysis identified five PCs that account for 77% of the total variance in 14 organochlorine compounds in the original dataset. The five PCs represent: (1) chlordane-related compounds and dieldrin; (2) p,p′-DDT and its degradates; (3) o,p′-DDT and its degradates; (4) the pesticide degradates oxychlordane and heptachlor epoxide; and (5) PCBs. The PC analysis grouped compounds that have similar chemical structure (such as parent compound and degradate), common origin (in the same technical pesticide mixture), and(or) similar relation of concentrations to land use. For example, the highest concentrations of chlordane compounds and dieldrin occurred at urban sites, reflecting past use of parent pesticides for termite control. Two approaches to characterizing mixtures—PC-based mixtures and unique mixtures—were applied to all 299 samples with a detection of two or more organochlorine compounds. PC-based mixtures are defined by the presence (in the sample) of one or more compounds associated with that PC. Unique mixtures are defined as a specific combination of two or more compounds detected in a sample, regardless of how many other compounds were also detected in that sample. The simplest PC-based mixtures (containing compounds from 1 or 2 PCs) commonly occurred in a variety of land use settings. Complex mixtures (containing compounds from 3 or more PCs) were most common in samples from urban and mixed/urban sites, especially in the Northeast, reflecting high concentrations of multiple chlordane, dieldrin, DDT

  11. Toxicity tests with crustaceans for detecting sublethal effects of potential endocrine disrupting chemicals

    DEFF Research Database (Denmark)

    Wollenberger, Leah

    on effects of potential endocrine disrupters on crustacean development and reproduction have been published since the beginning of the nineties. However, most crustacean toxicity test protocols routinely used so far have not been designed with endocrine-specific endpoints in mind. The main objectives...... of effective concentrations (ECx). After having demonstrated that larval development of A. tonsa was a very sensitive endpoint for evaluating effects of chemicals that might interfere with the endocrine system of crustaceans, the larval development test has been applied to two groups of emerging environmental...

  12. Microplastic potentiates triclosan toxicity to the marine copepod Acartia tonsa (Dana)

    DEFF Research Database (Denmark)

    Syberg, Kristian; Nielsen, Anne; Khan, Farhan

    2017-01-01

    Microplastics (MP) are contaminants of environmental concern partly due to plastics ability to sorb and transport hydrophobic organic contaminants (HOC). The importance of this "vector effect" is currently being debated in the scientific community. This debate largely ignores that the co-exposure......Microplastics (MP) are contaminants of environmental concern partly due to plastics ability to sorb and transport hydrophobic organic contaminants (HOC). The importance of this "vector effect" is currently being debated in the scientific community. This debate largely ignores that the co...... indicated that MP potentiate the toxicity of TCS, illustrating the importance of understanding the mixture interaction between plastics and HOC when addressing the environmental importance of the vector effect....

  13. Assessment of concentration in contaminated soil by potentially toxic elements using electrical properties.

    Science.gov (United States)

    Son, Younghwan

    2011-05-01

    Soils contaminated by potentially toxic elements (PTEs) which affect human health, such as zinc, lead, mercury, cadmium, and arsenic, were applied. The aims of this study are to judge contamination of soil and also to evaluate concentration of contaminated soil using electrical properties such as electrical resistivity and permittivity. The frequency was applied in the experiment ranged from 100 Hz to 10 MHz. As a result, the values of electrical resistivity and permittivity of each soil contaminated by PTEs could be presented as a function related to frequency and could determine whether the soil was contaminated. Also, results indicated that electrical properties give a reliable estimation of concentrations of PTEs contamination in soil.

  14. First record of potentially toxic dinoflagellate, Alexandrium minutum Halim 1960, from Peruvian coastal

    Directory of Open Access Journals (Sweden)

    Maribel Baylón

    2015-04-01

    Full Text Available Herein, we report the first record of the potentially toxic dinoflagellate Alexandrium minutum Halim 1960 from the Peruvian littoral. Alexandrium minutum produced the algae bloom in March 2006 and February 2009, in the Callao bay. Its identification was carried out by a morpho-taxonomic examination, detailing their plates with light and epifluorescence microscopy, moreover its quantification was realized in sedimentation chambers. This is the first report of A. minutum for Southeast Pacific. The characteristics in size, shape and thecal morphology were similarly to original descriptions of this species.

  15. 1,4-Naphthoquinone derivatives potently suppress Candida albicans growth, inhibit formation of hyphae and show no toxicity toward zebrafish embryos.

    Science.gov (United States)

    Janeczko, Monika; Kubiński, Konrad; Martyna, Aleksandra; Muzyczka, Angelika; Boguszewska-Czubara, Anna; Czernik, Sławomir; Tokarska-Rodak, Małgorzata; Chwedczuk, Marta; Demchuk, Oleg M; Golczyk, Hieronim; Masłyk, Maciej

    2018-04-01

    In this study, we applied various assays to find new activities of 1,4-naphthoquinone derivatives for potential anti-Candida albicans applications. These assays determined (a) the antimicrobial effect on growth/cell multiplication in fungal cultures, (b) the effect on formation of hyphae and biofilm, (c) the influence on cell membrane integrity, (d) the effect on cell morphology using atomic force microscopy, and (e) toxicity against zebrafish embryos. We have demonstrated the activity of these compounds against different Candida species and clinical isolates of C. albicans. 1,4-Naphthoquinones significantly affected fungal strains at 8-250 mg l -1 of MIC. Interestingly, at concentrations below MICs, the chemicals showed effectiveness in inhibition of hyphal formation and cell aggregation in Candida. Of note, atomic force microscopy (AFM) analysis revealed an influence of the compounds on cell morphological properties. However, at low concentrations (0.8-31.2 mg l -1 ), it did not exert any evident toxic effects on zebrafish embryos. Our research has evidenced the effectiveness of 1,4-naphthoquinones as potential anti-Candida agents.

  16. Preliminary Assessment of Health Risks of Potentially Toxic Elements in Settled Dust over Beijing Urban Area

    Directory of Open Access Journals (Sweden)

    Dejun Wan

    2016-05-01

    Full Text Available To examine levels, health risks, sources, and spatial distributions of potentially toxic elements in settled dust over Beijing urban area, 62 samples were collected mostly from residential building outdoor surfaces, and their <63 μm fractions were measured for 12 potentially toxic elements. The results show that V, Cr, Mn, Co, Ni, and Ba in dust are from predominantly natural sources, whereas Cu, Zn, As, Cd, Sb, and Pb mostly originate from anthropogenic sources. Exposure to these elements in dust has significant non-cancer risks to children but insignificant to adults. Cancer risks of Cr, Co, Ni, As, and Cd via inhalation and dermal contact are below the threshold of 10−6–10−4 but As via dust ingestion shows a tolerable risk. The non-cancer risks to children are contributed mainly (75% by As, Pb, and Sb, and dominantly (92% via dust ingestion, with relatively higher risks mainly occurring in the eastern and northeastern Beijing urban areas. Although Cd, Zn, and Cu in dust are heavily affected by anthropogenic sources, their health risks are insignificant. Source appointments suggest that coal burning emissions, the dominant source of As, are likely the largest contributors to the health risk, and traffic-related and industrial emissions are also important because they contribute most of the Pb and Sb in dust.

  17. Biosorption: An Interplay between Marine Algae and Potentially Toxic Elements—A Review

    Science.gov (United States)

    Bilal, Muhammad; Rasheed, Tahir; Raza, Ali; Nabeel, Faran

    2018-01-01

    In recent decades, environmental pollution has emerged as a core issue, around the globe, rendering it of fundamental concern to eco-toxicologists, environmental biologists, eco-chemists, pathologists, and researchers from other fields. The dissolution of polluting agents is a leading cause of environmental pollution of all key spheres including the hydrosphere, lithosphere, and biosphere, among others. The widespread occurrence of various pollutants including toxic heavy metals and other emerging hazardous contaminants is a serious concern. With increasing scientific knowledge, socioeconomic awareness, human health problems, and ecological apprehensions, people are more concerned about adverse health outcomes. Against this background, several removal methods have been proposed and implemented with the aim of addressing environmental pollution and sustainable and eco-friendly development. Among them, the biosorption of pollutants using naturally inspired sources, e.g., marine algae, has considerable advantages. In the past few years, marine algae have been extensively studied due to their natural origin, overall cost-effective ratio, and effectiveness against a broader pollutant range; thus, they are considered a potential alternative to the conventional methods used for environmental decontamination. Herein, an effort has been made to highlight the importance of marine algae as naturally inspired biosorbents and their role in biosorption. Biosorption mechanisms and factors affecting biosorption activities are also discussed in this review. The utilization of marine algae as a biosorbent for the removal of numerous potentially toxic elements has also been reviewed. PMID:29463058

  18. Biosorption: An Interplay between Marine Algae and Potentially Toxic Elements-A Review.

    Science.gov (United States)

    Bilal, Muhammad; Rasheed, Tahir; Sosa-Hernández, Juan Eduardo; Raza, Ali; Nabeel, Faran; Iqbal, Hafiz M N

    2018-02-19

    In recent decades, environmental pollution has emerged as a core issue, around the globe, rendering it of fundamental concern to eco-toxicologists, environmental biologists, eco-chemists, pathologists, and researchers from other fields. The dissolution of polluting agents is a leading cause of environmental pollution of all key spheres including the hydrosphere, lithosphere, and biosphere, among others. The widespread occurrence of various pollutants including toxic heavy metals and other emerging hazardous contaminants is a serious concern. With increasing scientific knowledge, socioeconomic awareness, human health problems, and ecological apprehensions, people are more concerned about adverse health outcomes. Against this background, several removal methods have been proposed and implemented with the aim of addressing environmental pollution and sustainable and eco-friendly development. Among them, the biosorption of pollutants using naturally inspired sources, e.g., marine algae, has considerable advantages. In the past few years, marine algae have been extensively studied due to their natural origin, overall cost-effective ratio, and effectiveness against a broader pollutant range; thus, they are considered a potential alternative to the conventional methods used for environmental decontamination. Herein, an effort has been made to highlight the importance of marine algae as naturally inspired biosorbents and their role in biosorption. Biosorption mechanisms and factors affecting biosorption activities are also discussed in this review. The utilization of marine algae as a biosorbent for the removal of numerous potentially toxic elements has also been reviewed.

  19. Biosorption: An Interplay between Marine Algae and Potentially Toxic Elements—A Review

    Directory of Open Access Journals (Sweden)

    Muhammad Bilal

    2018-02-01

    Full Text Available In recent decades, environmental pollution has emerged as a core issue, around the globe, rendering it of fundamental concern to eco-toxicologists, environmental biologists, eco-chemists, pathologists, and researchers from other fields. The dissolution of polluting agents is a leading cause of environmental pollution of all key spheres including the hydrosphere, lithosphere, and biosphere, among others. The widespread occurrence of various pollutants including toxic heavy metals and other emerging hazardous contaminants is a serious concern. With increasing scientific knowledge, socioeconomic awareness, human health problems, and ecological apprehensions, people are more concerned about adverse health outcomes. Against this background, several removal methods have been proposed and implemented with the aim of addressing environmental pollution and sustainable and eco-friendly development. Among them, the biosorption of pollutants using naturally inspired sources, e.g., marine algae, has considerable advantages. In the past few years, marine algae have been extensively studied due to their natural origin, overall cost-effective ratio, and effectiveness against a broader pollutant range; thus, they are considered a potential alternative to the conventional methods used for environmental decontamination. Herein, an effort has been made to highlight the importance of marine algae as naturally inspired biosorbents and their role in biosorption. Biosorption mechanisms and factors affecting biosorption activities are also discussed in this review. The utilization of marine algae as a biosorbent for the removal of numerous potentially toxic elements has also been reviewed.

  20. Chemical form of metals in traditional medicines underlines potential toxicity in cell cultures.

    Science.gov (United States)

    Wu, Qin; Lu, Yuan-Fu; Shi, Jing-Zhen; Liang, Shi-Xia; Shi, Jin-Shan; Liu, Jie

    2011-04-12

    Mercury (Hg) and arsenic (As) are frequently found in traditional medicines as sulfides, such as cinnabar (HgS) and realgar (As(4)S(4)). There is a general perception that any medicinal use of such metal-containing remedies is unacceptable. An opposing opinion is that different chemical forms of arsenic and mercury have different toxic potentials. To clarify this question, cinnabar, realgar, and cinnabar- and realgar-containing traditional medicine An-Gong-Niu-HuangWan (AGNH), were compared to well-known mercurials (HgS, HgCl(2) and MeHg) and arsenicals (As(2)S(2), As(2)O(3), NaAsO(2), and Na(2)HAsO(4)) for their cytotoxicity in human and rodent cell lines. Cultured cells derived from target organs such as brain (HAPI) and liver (Hep3B, HepG2 and TRL1215) were treated with chemicals for 48 h and cytotoxicity was determined by the MTS assay. MeHg was most toxic with LC(50) of 4-20μM, followed by NaAsO(2) (LC(50), 25-250 μM) and HgCl(2) (LC(50,) 50-100 μM), Na(2)HAsO(4)(LC(50), 60-400μM), As(2)O(3)(LC(50), 30-900 μM), and As(2)S(2) (LC(50), 100-500 μM). In comparison, the LC(50) of realgar ranged from 250 to1500 μM; whereas cinnabar or HgS were approximately 20,000 μM and the toxicity of AGNH was in the range of 1500-8000 μM. Approximately 5000-fold differences exist between MeHg and HgS, and over 10-fold differences exist between NaAsO(2) and As(4)S(4). Chemical forms of metals are important factor in determining their toxicity in traditional medicines, both cinnabar and realgar are much less toxic than well-known mercurial and arsenicals. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. Inorganic carbon acquisition in potentially toxic and non-toxic diatoms: the effect of pH-induced changes in the seawater carbonate chemistry

    DEFF Research Database (Denmark)

    Trimborn, S; Lundholm, Nina; Thoms, S

    2008-01-01

    The effects of pH-induced changes in seawater carbonate chemistry on inorganic carbon (C-i) acquisition and domoic acid (DA) production were studied in two potentially toxic diatom species, Pseudo-nitzschia multiseries and Nitzschia navis-varingica, and the non-toxic Stellarima stellaris. In vivo......H-dependence of growth, the 'HCO3- user' S. stellaris was as sensitive as the 'CO2 user' N. navis-varingica. The suggested relationship between DA and carbon acquisition/C-i limitation could not be confirmed....

  2. Complex mixtures of dissolved pesticides show potential aquatic toxicity in a synoptic study of Midwestern U.S. streams

    Science.gov (United States)

    Nowell, Lisa H.; Moran, Patrick W.; Schmidt, Travis S.; Norman, Julia E.; Nakagaki, Naomi; Shoda, Megan E.; Mahler, Barbara J.; Van Metre, Peter C.; Stone, Wesley W.; Sandstrom, Mark W.; Hladik, Michelle L.

    2018-01-01

    Aquatic organisms in streams are exposed to pesticide mixtures that vary in composition over time in response to changes in flow conditions, pesticide inputs to the stream, and pesticide fate and degradation within the stream. To characterize mixtures of dissolved-phase pesticides and degradates in Midwestern streams, a synoptic study was conducted at 100 streams during May–August 2013. In weekly water samples, 94 pesticides and 89 degradates were detected, with a median of 25 compounds detected per sample and 54 detected per site. In a screening-level assessment using aquatic-life benchmarks and the Pesticide Toxicity Index (PTI), potential effects on fish were unlikely in most streams. For invertebrates, potential chronic toxicity was predicted in 53% of streams, punctuated in 12% of streams by acutely toxic exposures. For aquatic plants, acute but likely reversible effects on biomass were predicted in 75% of streams, with potential longer-term effects on plant communities in 9% of streams. Relatively few pesticides in water—atrazine, acetochlor, metolachlor, imidacloprid, fipronil, organophosphate insecticides, and carbendazim—were predicted to be major contributors to potential toxicity. Agricultural streams had the highest potential for effects on plants, especially in May–June, corresponding to high spring-flush herbicide concentrations. Urban streams had higher detection frequencies and concentrations of insecticides and most fungicides than in agricultural streams, and higher potential for invertebrate toxicity, which peaked during July–August. Toxicity-screening predictions for invertebrates were supported by quantile regressions showing significant associations for the Benthic Invertebrate-PTI and imidacloprid concentrations with invertebrate community metrics for MSQA streams, and by mesocosm toxicity testing with imidacloprid showing effects on invertebrate communities at environmentally relevant concentrations. This study documents the most

  3. Toxic potential of the emerging contaminant nicotine to the aquatic ecosystem.

    Science.gov (United States)

    Oropesa, Ana Lourdes; Floro, António Miguel; Palma, Patrícia

    2017-07-01

    Nicotine is a "life-style compound" widely consumed by human populations and, consequently, often found in surface waters. This fact presents a concern for possible effects in the aquatic ecosystems. The objective of this study was to assess the potential lethal and sublethal toxicity of nicotine in aquatic organisms from different trophic levels (Vibrio fischeri, Pseudokirchneriella subcapitata, Thamnocephalus platyurus, and Daphnia magna). The bioassays were performed by exposing the organisms to concentrations of nicotine in a range of 0.5-1000 μg/L. Results showed that nicotine, at tested concentration, was not acutely toxic to V. fischeri and T. platyurus. On the contrary, this substance exhibited toxicity to P. subcapitata and Daphnia magna. Thus, concentrations of nicotine of 100 and 200 μg/L promoted an inhibition in the growth of P. subcapitata. In addition, a concentration of 100 μg/L nicotine acted on the reproduction of the crustacean D. magna, by decreasing the number of juveniles produced by female. On the other hand, the results showed that concentrations equal to or greater than 10 μg/L induced the production of daphnids male offspring, which may indicate that nicotine is a weak juvenoid compound of the D. magna endocrine system. Furthermore, the result showed that concentrations tested of this chemical have the capacity to revert the effect of fenoxycarb, a strong juvenoid chemical insecticide. The results of the study revealed that nicotine can induce several changes in some of the most important key groups of the aquatic compartment, which can compromise, in a short time, the balance of aquatic ecosystem. Finally, a preliminary environmental risk assessment of this stimulant was performed from the highest measured concentration in surface water and the no observable effect concentration value in the most sensitive species, i.e., D. magna. This process revealed that nicotine can produce an important risk to aquatic organisms.

  4. Potential environmental impacts of light-emitting diodes (LEDs): metallic resources, toxicity, and hazardous waste classification.

    Science.gov (United States)

    Lim, Seong-Rin; Kang, Daniel; Ogunseitan, Oladele A; Schoenung, Julie M

    2011-01-01

    Light-emitting diodes (LEDs) are advertised as environmentally friendly because they are energy efficient and mercury-free. This study aimed to determine if LEDs engender other forms of environmental and human health impacts, and to characterize variation across different LEDs based on color and intensity. The objectives are as follows: (i) to use standardized leachability tests to examine whether LEDs are to be categorized as hazardous waste under existing United States federal and California state regulations; and (ii) to use material life cycle impact and hazard assessment methods to evaluate resource depletion and toxicity potentials of LEDs based on their metallic constituents. According to federal standards, LEDs are not hazardous except for low-intensity red LEDs, which leached Pb at levels exceeding regulatory limits (186 mg/L; regulatory limit: 5). However, according to California regulations, excessive levels of copper (up to 3892 mg/kg; limit: 2500), Pb (up to 8103 mg/kg; limit: 1000), nickel (up to 4797 mg/kg; limit: 2000), or silver (up to 721 mg/kg; limit: 500) render all except low-intensity yellow LEDs hazardous. The environmental burden associated with resource depletion potentials derives primarily from gold and silver, whereas the burden from toxicity potentials is associated primarily with arsenic, copper, nickel, lead, iron, and silver. Establishing benchmark levels of these substances can help manufacturers implement design for environment through informed materials substitution, can motivate recyclers and waste management teams to recognize resource value and occupational hazards, and can inform policymakers who establish waste management policies for LEDs.

  5. Diclofenac toxicity in human intestine ex vivo is not related to the formation of intestinal metabolites

    NARCIS (Netherlands)

    Niu, Xiaoyu; de Graaf, Inge A. M.; Langelaar-Makkinje, Miriam; Horvatovich, Peter; Groothuis, Geny M. M.

    The use of diclofenac (DCF), a nonsteroidal anti-inflammatory drug, is associated with a high prevalence of gastrointestinal side effects. In vivo studies in rodents suggested that reactive metabolites of DCF produced by the liver or the intestine might be responsible for this toxicity. In the

  6. Role of heat shock protein hsp90 in formation of protective reactions in acute toxic stress.

    Science.gov (United States)

    Glushkova, O V; Novoselova, T V; Khrenov, M O; Parfenyuk, S B; Lunin, S M; Fesenko, E E; Novoselova, E G

    2010-06-01

    The involvement of heat shock protein Hsp90 in pro-inflammatory response in male NMRI mice under conditions of acute toxic stress, caused by lipopolysaccharide from Gram negative bacteria, was studied using geldanamycin, a specific blocker of the activity of this protein. It is shown that the introduction of geldanamycin lowers total intoxication of the organism upon acute toxic stress caused by endotoxin. Thus, a decrease in cytokine TNF-alpha, IFN-gamma, IL-1, and IL-10 concentrations in blood serum of the geldanamycin-treated animals with acute toxic stress was found along with normalization of functional activity of nitric oxide producing peritoneal macrophages. Studying expression of receptor protein Tlr-4 as well of proteins of two signal cascades, NF-kappaB and SAPK/JNK, has shown that mechanisms of the geldanamycin protective effect are realized at the level of inhibition of Tlr-4 receptor expression, which provides for endotoxin-to-cell binding, and due to lowering the endotoxin-stimulated activation of signal cascades NF-kappaB and SAPK/JNK. The results suggest Hsp90 might be a therapeutic target in diseases accompanied by acute toxic stress.

  7. Reviews of the toxicity behavior of five potential engineered nanomaterials (ENMs into the aquatic ecosystem

    Directory of Open Access Journals (Sweden)

    Shanaz Jahan

    Full Text Available Presently, engineered nanomaterials (ENMs are used in a wide variety of commercial applications, resulting in an uncontrolled introduction into the aquatic environment. The purpose of this review is to summarize the pathways and factors that controlling the transport and toxicity of five extensively used ENMs. These toxicological pathways are of great importance and need to be addressed for sustainable implications of ENMs without environmental liabilities. Here we discuss five potentially utilized ENMs with their possible toxicological risk factors to aquatic plants, vertebrates model and microbes. Moreover, the key effect of ENMs surface transformations by significant reaction with environmental objects such as dissolved natural organic matter (DOM and the effect of ENMs surface coating and surface charge will also be debated. The transformations of ENMs are subsequently facing a major ecological transition that is expected to create a substantial toxicological effect towards the ecosystem. These transformations largely involve chemical and physical processes, which depend on the properties of both ENMs and the receiving medium. In this review article, the critical issues that controlling the transport and toxicity of ENMs are reviewed by exploiting the latest reports and future directions and targets are keenly discussed to minimize the pessimistic effects of ENMs. Keywords: Nanotechnology, Nanomaterials, Ecotoxicology, Environmental transport, Risk assessment

  8. Engineered Nanoparticles as Potential Food Contaminants and Their Toxicity to Caco-2 Cells.

    Science.gov (United States)

    Mao, Xiaomo; Nguyen, Trang H D; Lin, Mengshi; Mustapha, Azlin

    2016-08-01

    Engineered nanoparticles (ENPs), such as metallic or metallic oxide nanoparticles (NPs), have gained much attention in recent years. Increasing use of ENPs in various areas may lead to the release of ENPs into the environment and cause the contamination of agricultural and food products by ENPs. In this study, we selected two important ENPs (zinc oxide [ZnO] and silver [Ag] NPs) as potential food contaminants and investigated their toxicity via an in vitro model using Caco-2 cells. The physical properties of ENPs and their effects on Caco-2 cells were characterized by electron microscopy and energy dispersive X-ray spectroscopic (EDS) techniques. Results demonstrate that a significant inhibition of cell viability was observed after a 24-h of exposure of Caco-2 cells to 3-, 6-, and 12-mM ZnO NPs or 0.5-, 1.5-, and 3-mM Ag NPs. The noticeable changes of cells include the alteration in cell shape, abnormal nuclear structure, membrane blebbing, and cytoplasmic deterioration. The toxicity of ZnO NPs, but not that of Ag NPs after exposure to simulated gastric fluid, significantly decreased. Scanning transmission electron microscopy shows that ZnO and Ag NPs penetrated the membrane of Caco-2 cells. EDS results also confirm the presence of NPs in the cytoplasm of the cells. This study demonstrates that ZnO and Ag NPs have cytotoxic effects and can inhibit the growth of Caco-2 cells. © 2016 Institute of Food Technologists®

  9. Evaluation of potentially toxic metals pollution in the sediments of the Kor river, southwest Iran.

    Science.gov (United States)

    Sheykhi, V; Moore, F

    2013-04-01

    This study is carried out to evaluate potentially toxic metal concentrations (As, Cd, Cr, Cu, Hg, Mo, Ni, Pb, and Zn) together with their spatial distribution, degree of pollution, and potential ecological risk in Kor river sediments (southwest Iran) using sediment quality guidelines, geoaccumulation index (I geo), Hakanson potential ecological risk index (RI), and standard methods of statistical analysis. The study area stretches some 140 km from the Drodzan Dam to Bakhtegan Lake, a stretch of river where different industrial and domestic activities (e.g., petrochemical complex, oil refinery, industrial meat processing complex, Marvdasht city sewage) and ecological value overlap with each other. Calculated geoaccumulation index indicate that 50 % of the stations are moderately to very extremely polluted. The potential ecological risk for nine investigated metals in Kor river is Hg (948) > Mo (51.9) > Ni (37.8) > Cd (29.8) > As (22) > Cu (16.6) > Pb (13.3) > Zn (3.3) > Cr (1). Results show that sediments in parts of Kor river sediments are heavily affected by effluents discharged from industrial plants and other parts are affected by agriculture and urban runoff from nearby lands. These phenomena may cause a risk of secondary water pollution under sediment disturbance and/or changes in the physical-chemical characteristics of the aquatic system.

  10. Formation of Developmentally Toxic Phenanthrene Metabolite Mixtures by Mycobacterium sp. ELW1.

    Science.gov (United States)

    Schrlau, Jill E; Kramer, Amber L; Chlebowski, Anna; Truong, Lisa; Tanguay, Robert L; Simonich, Staci L Massey; Semprini, Lewis

    2017-08-01

    Mycobacterium sp. ELW1 co-metabolically degraded up to 1.8 μmol of phenanthrene (PHE) in ∼48 h, and hydroxyphenanthrene (OHPHE) metabolites, including 1-hydroxyphenanthrene (1-OHPHE), 3-hydroxyphenanthrene (3-OHPHE), 4-hydroxyphenanthrene (4-OHPHE), 9-hydroxyphenanthrene (9-OHPHE), 9,10-dihydroxyphenanthrene (1,9-OHPHE), and trans-9,10-dihydroxy-9,10-dihydrophenanthrene (trans-9,10-OHPHE), were identified and quantified over time. The monooxygenase responsible for co-metabolic transformation of PHE was inhibited by 1-octyne. First-order PHE transformation rates, k PHE , and half-lives, t 1/2 , for PHE-exposed cells were 0.16-0.51 h -1 and 1.4-4.3 h, respectively, and the 1-octyne controls ranged from 0.015-0.10 h -1 to 7.0-47 h, respectively. While single compound standards of PHE and trans-9,10-OHPHE, the major OHPHE metabolite formed by ELW1, were not toxic to embryonic zebrafish (Danio rerio), single compound standards of minor OHPHE metabolites, 1-OHPHE, 3-OHPHE, 4-OHPHE, 9-OHPHE, and 1,9-OHPHE, were toxic, with effective concentrations (EC 50 's) ranging from 0.5 to 5.5 μM. The metabolite mixtures formed by ELW1, and the reconstructed standard mixtures of the identified OHPHE metabolites, elicited a toxic response in zebrafish for the same three time points. EC 50 s for the metabolite mixtures formed by ELW1 were lower (more toxic) than those for the reconstructed standard mixtures of the identified OHPHE metabolites. Ten unidentified hydroxy PHE metabolites were measured in the derivatized mixtures formed by ELW1 and may explain the increased toxicity of the ELW1 metabolites mixture relative to the reconstructed standard mixtures of the identified OHPHE metabolites.

  11. Accommodation of potential hydrogen formation in LMFBR accidents

    International Nuclear Information System (INIS)

    Stepnewski, D.D.; Peak, R.D.; Mahaffey, M.K.

    1981-01-01

    Results of design verification tests for the FFTF reactor cavity liner system are presented which suggest that steel liners would retain their integrity even under certain hypothetical accident conditions, thus avoiding the formation of hydrogen. When liner failures are postulate in hypothetical reactor vessel meltthrough accidents, hydrogen levels can be controlled by an air purging system. The design of a containment purging and effluent scrubbing system is discussed

  12. Biological effect of Acidithiobacillus thiooxidans on some potentially toxic elements during alteration of SON 68 nuclear glass

    Science.gov (United States)

    Bachelet, M.; Crovisier, J. L.; Stille, P.; Vuilleumier, S.; Geoffroy, V.

    2009-04-01

    Although underground nuclear waste repositories are not expected to be favourable places for microbial activity, one should not exclude localized action of extremophilic bacteria on some materials involved in the storage concept. Among endogenous or accidentally introduced acidophiles, some are susceptible to lead to a locally drastic decreased in pH, with potential consequences on materials corrosion. Experiments were performed with Acidithiobacillus thiooxidans on 100-125 m french reference nuclear glass SON68 grains in a mineral medium under static conditions during 60 days at 25degC. Growth medium was periodically renewed and analyzed by ICP-AES and ICP-MS spectrometry for both major, trace and ultra-trace elements. Biofilm formation was evidenced by confocal laser microscopy, staining DNA with ethidium bromide and exopolysaccharides with calcofluor white. Biofilm thickness around material grains exceeded 20 m under the chosen experimental conditions. It can be noticed that while numerous studies on biofilm formation upon interaction between Acidithiobacillus ferrooxidans and materials are found in the literature, evidence for biofilm formation is still scarce for the case of the acidophilic bacterium A. thiooxidans. Presence of biofilm is a key parameter for material alteration at the solid/solution interface in biotic systems. Indeed, various constitutive elements of materials trapped in the polyanionic polymer of biofilm may also influence the alteration process. In particular, biofilm may reduce the alteration rate of materials by forming a protective barrier at their surface (Aouad et al., 2008). In this study, glass alteration rates, determined using strontium as tracer, showed that the progressive formation of a biofilm on the surface of glass has a protective effect against its alteration. Uranium and rare earth elements (REE) are efficiently trapped in the biogenic compartment of the system (exopolysaccharides + bacterial cells). Besides, the ratio

  13. Potential Medicinal Application and Toxicity Evaluation of Extracts from Bamboo Plants.

    Science.gov (United States)

    Panee, Jun

    2015-06-01

    Bamboo plants play a significant role in traditional Asian medicine, especially in China and Japan. Biomedical investigations on the health-benefiting effects as well as toxicity of different parts and species of bamboo have been carried out worldwide since the 1960s, and documented a wide range of protective effects of bamboo-derived products, such as protection against oxidative stress, inflammation, lipotoxicity, cancer, and cardiovascular disease. Some of these products may interfere with male and female reproductive function, thyroid hormone metabolism, and hepatic xenobiotransformation enzymes. The diversity of bamboo species, parts of the plants available for medicinal use, and different extraction methods suggest that bamboo has great potential for producing a range of extracts with functional utility in medicine.

  14. Impact of Saw Dust Application on the Distribution of Potentially Toxic Metals in Contaminated Soil.

    Science.gov (United States)

    Awokunmi, Emmmanuel E

    2017-12-01

    The need to develop an approach for the reclamation of contaminated site using locally available agricultural waste has been considered. The present study investigated the application of sawdust as an effective amendment in the immobilization of potentially toxic metals (PTMs) by conducting a greenhouse experiment on soil collected from an automobile dumpsite. The amended and non-amended soil samples were analyzed for their physicochemical parameters and sequential extraction of PTMs. The results revealed that application of amendment had positive impact on the physicochemical parameters as organic matter content and cation exchange capacity increased from 12.1% to 12.8% and 16.4 to 16.8 meq/100 g respectively. However, the mobility and bioavalability of these metals was reduced as they were found to be distributed mostly in the non-exchangeable phase of soil. Therefore, application of sawdust successfully immobilized PTMs and could be applied for future studies in agricultural soil reclamation.

  15. Distribution of potentially toxic elements in the Brazilian phosphogypsum and phosphate fertilizers

    Directory of Open Access Journals (Sweden)

    Saueia C. H. R.

    2013-04-01

    Full Text Available The Brazilian phosphate fertilizer is obtained by wet reaction of the igneous phosphate rock with concentrated sulphuric acid, giving as final product phosphoric acid and dehydrated calcium sulphate (phosphogypsum as by-product. Phosphoric acid is the raw material for the production of phosphate fertilizers (SSP, TSP, MAP and DAP. Phosphogypsum waste is stored in stacks, since its level of impurities (metals and radionuclides among others prevent its safe reutilization. However, part of this waste is used to improve fertility of agricultural soils. The main aim of this paper is to determine the levels of potentially toxic elements in phosphate fertilizers and phosphogypsum produced in Brazil. The elements Co and Cr were analyzed by instrumental neutron activation analysis and As, Cd, Cu, Hg, Ni, Pb, Se and Zn were analyzed by ICP-OES. The results obtained are lower than the limits established by the Brazilian regulatory agency for metals in fertilizers and soil conditioner.

  16. Development of Comparative Toxicity Potentials of 14 cationic metals in freshwater

    DEFF Research Database (Denmark)

    Dong, Yan; Gandhi, Nilima; Hauschild, Michael Zwicky

    2014-01-01

    . CTPs were calculated for 7 EUarchetypes, taking bioavailability and speciation pattern into account. The resulting site-dependent CTPs showed up to 2.4–6.5 orders of magnitude variation across archetypes for those metals that form stable hydroxyl compounds in slightly alkaline waters (Al(III), Be, Cr......Site-dependent and site-generic Comparative Toxicity Potentials (CTPs) (also known as Characterization Factors (CFs)) were calculated for 14 cationic metals (Al(III), Ba, Be, Cd, Co, Cr(III), Cs, Cu(II), Fe(II), Fe(III), Mn(II), Ni, Pb, Sr and Zn), to be applied in Life Cycle Impact Assessment......(III), Cu(II) and Fe(III)), emphasizing the importance of using site-dependent CTPs for these metals where possible. For the other metals, CTPs stayed within around 0.9 orders of magnitude, making spatial differentiation less important. In acidic waters (pH

  17. Formation and fates of nitrosamines and their formation potentials from a surface water source to drinking water treatment plants in Southern Taiwan.

    Science.gov (United States)

    Chen, Wei-Hsiang; Wang, Chung-Ya; Huang, Tsung-Hsien

    2016-10-01

    Nitrosamines are toxic and emerging disinfection byproducts. In this study, three drinking water treatment plants (DWTPs) in southern Taiwan treating the same source water in Gaoping River with comparable technologies were selected. The objective was to evaluate the formation and fates of six nitrosamines and their formation potentials (FPs) from a surface water source to drinking water. Albeit decreased further downstream in the river, four nitrosamine-FPs were observed in the source water due to anthropogenic pollution in the upstream areas. In the DWTPs, nitrosamines were formed and NDMA was the main species. While high organic carbon concentrations indicated elevated nitrosamine-FPs in the source water, NDMA formation in the DWTPs was more positively associated with reductions of water parameters that quantify organic matters with double bonded ring structures. Although precursor removal via pre-oxidation is a viable approach to limit nitrosamine formation during post-disinfection, this study clearly indicates that a great portion of NDMA in treated water has been formed in the 1st oxidation step of drinking water treatment. The pre-oxidation simulations in the lab demonstrated the impact of pre-chlorination on nitrosamine formation. Given the limited removal in conventional treatment processes, avoiding nitrosamine-FPs in sources and/or nitrosamine formation during pre-oxidation become important issues to control the threats of nitrosamines in drinking water. Under current circumstance in which pre-oxidation is widely used to optimize the treatment effectiveness in many DWTPs, its adverse effect by forming nitrosamines needs to be carefully minimized and using technologies other than pre-chlorination (e.g., pre-ozonation) may be considered. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Potential of extracellular microRNAs as biomarkers of acetaminophen toxicity in children

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xi, E-mail: Xi.Yang@fda.hhs.gov [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); Salminen, William F., E-mail: Willie.Salminen@parexel.com [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); Shi, Qiang, E-mail: Qiang.Shi@fda.hhs.gov [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); Greenhaw, James, E-mail: James.Greenhaw@fda.hhs.gov [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); Gill, Pritmohinder S., E-mail: PSGill@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR (United States); Clinical Pharmacology and Toxicology Section, Arkansas Children' s Hospital, Little Rock, AR (United States); Bhattacharyya, Sudeepa, E-mail: SBhattacharyya2@uams.edu [Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR (United States); Clinical Pharmacology and Toxicology Section, Arkansas Children' s Hospital, Little Rock, AR (United States); Beger, Richard D., E-mail: Richard.Beger@fda.hhs.gov [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); Mendrick, Donna L., E-mail: Donna.Mendrick@fda.hhs.gov [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); Mattes, William B., E-mail: William.Mattes@fda.hhs.gov [Division of Systems Biology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR (United States); and others

    2015-04-15

    Developing biomarkers for detecting acetaminophen (APAP) toxicity has been widely investigated. Recent studies of adults with APAP-induced liver injury have reported human serum microRNA-122 (miR-122) as a novel biomarker of APAP-induced liver injury. The goal of this study was to examine extracellular microRNAs (miRNAs) as potential biomarkers for APAP liver injury in children. Global levels of serum and urine miRNAs were examined in three pediatric subgroups: 1) healthy children (n = 10), 2) hospitalized children receiving therapeutic doses of APAP (n = 10) and 3) children hospitalized for APAP overdose (n = 8). Out of 147 miRNAs detected in the APAP overdose group, eight showed significantly increased median levels in serum (miR-122, -375, -423-5p, -30d-5p, -125b-5p, -4732-5p, -204-5p, and -574-3p), compared to the other groups. Analysis of urine samples from the same patients had significantly increased median levels of four miRNAs (miR-375, -940, -9-3p and -302a) compared to the other groups. Importantly, correlation of peak serum APAP protein adduct levels (an indicator of the oxidation of APAP to the reactive metabolite N-acetyl-para-quinone imine) with peak miRNA levels showed that the highest correlation was observed for serum miR-122 (R = 0.94; p < 0.01) followed by miR-375 (R = 0.70; p = 0.05). Conclusion: Our findings demonstrate that miRNAs are increased in children with APAP toxicity and correlate with APAP protein adducts, suggesting a potential role as biomarkers of APAP toxicity. - Highlights: • Serum miR-122 and miR-375 levels were increased in children with APAP overdose. • Urine levels of miR-375 and miR-940 were increased in the APAP overdose group. • Peak serum miR-122 levels were correlated with peak serum APAP protein adducts.

  19. Involvement of membrane potential in alkaline band formation by internodal cells of Chara corallina.

    Science.gov (United States)

    Shimmen, Teruo; Wakabayashi, Akiko

    2008-10-01

    Internodal cells of Chara corallina form alkaline bands on their surface upon illumination via photosynthesis. In the present study, the effect of KCl on alkaline band formation was analyzed. When the extracellular KCl concentration was increased, alkaline band formation was extensively inhibited. Electrophysiological analysis unequivocally showed the need for inner negative membrane potential for alkaline band formation.

  20. Alleviation of Al Toxicity by Si Is Associated with the Formation of Al–Si Complexes in Root Tissues of Sorghum

    Directory of Open Access Journals (Sweden)

    Peter M. Kopittke

    2017-12-01

    Full Text Available Silicon is reported to reduce the toxic effects of Al on root elongation but the in planta mechanism by which this occurs remains unclear. Using seedlings of soybean (Glycine max and sorghum (Sorghum bicolor, we examined the effect of up to 2 mM Si on root elongation rate (RER in Al-toxic nutrient solutions. Synchrotron-based low energy X-ray fluorescence (LEXRF was then used for the in situ examination of the distribution of Al and Si within cross-sections cut from the apical tissues of sorghum roots. The addition of Si potentially increased RER in Al-toxic solutions, with RER being up to ca. 0.3 mm h-1 (14% higher for soybean and ca. 0.2 mm h-1 (17% higher for sorghum relative to solutions without added Si. This improvement in RER could not be attributed to a change in Al-chemistry of the bulk nutrient solution, nor was it due to a change in the concentration of Al within the apical (0–10 mm root tissues. Using LEXRF to examine sorghum, it was demonstrated that in roots exposed to both Al and Si, much of the Al was co-located with Si in the mucigel and outer apoplast. These observations suggest that Si reduces the toxicity of Al in planta through formation of Al–Si complexes in mucigel and outer cellular tissues, thereby decreasing the binding of Al to the cell wall where it is known to inhibit wall loosening as required for cell elongation.

  1. TBI-Induced Formation of Toxic Tau and Its Biochemical Similarities to Tau in AD Brains

    Science.gov (United States)

    2016-10-01

    Distribution Unlimited The views , opinions and/or findings contained in this report are those of the author(s) and should not be construed as an...official Department of the Army position, policy or decision unless so designated by other documentation. REPORT DOCUMENTATION PAGE Form Approved OMB...electrophysiological impairments. Specifically we will test the hypothesis that 1) blast-induced TBI leads to the production of a toxic form of tau that contributes

  2. Water extracts of Brassica oleracea var. costata potentiate paraquat toxicity to rat hepatocytes in vitro.

    Science.gov (United States)

    Sousa, C; Pontes, H; Carmo, H; Dinis-Oliveira, R J; Valentão, P; Andrade, P B; Remião, F; Bastos, M L; Carvalho, F

    2009-09-01

    Tronchuda cabbage extracts have been proven to have antioxidant potential against various oxidative species in cell free systems, though its antioxidant potential in cellular models remained to be demonstrated. In the present study, we used primary cultures of rat hepatocytes for the cellular assay system and paraquat PQ exposure as a pro-oxidant model agent, to test whether tronchuda cabbage hydrolysed water extracts provide protective or aggravating effects towards PQ-induced oxidative stress and cell death. For this purpose cellular parameters related to oxidative stress were measured, namely the generation of superoxide anion, glutathione oxidation, lipid peroxidation, intracellular ATP levels, activation of nuclear factor-kappaB (NF-kappaB), activity of antioxidant enzymes, and cell death. The obtained results demonstrated that the studied hydrolysed water extracts of tronchuda cabbage, especially rich in kaempferol (84%) and other polyphenols, namely hydroxycinnamic acids and traces of quercetin, can potentiate the toxicity of PQ in primary cultures of rat hepatocytes. These results highlight that prospective antioxidant effects of plant extracts, observed in vitro, using non-cellular systems, are not always confirmed in cellular models, in which the concentrations required to scavenge pro-oxidant species may be highly detrimental to the cells.

  3. Potentially toxic trace element contamination, sources, and pollution assessment in farmlands, Bijie City, southwestern China.

    Science.gov (United States)

    Yuan, Zhimin; Yao, Jun; Wang, Fei; Guo, Zunwei; Dong, Zeqin; Chen, Feng; Hu, Yu; Sunahara, Geoffrey

    2017-01-01

    Artisanal zinc smelting activities, which had been widely applied in Bijie City, Guizhou Province, southwestern of China, can pollute surrounding farmlands. In the present study, 177 farmland topsoil samples of Bijie City were collected and 11 potentially toxic trace elements (PTEs), namely Pb, Zn, Cu, Ni, Co, Mn, Cr, V, Hg, As, and Cd were tested to characterize the concentrations, sources, and ecological risks. Mean concentrations of these PTEs in soils were (mg/kg) as follows: Pb (127), Zn (379), Cu (93.1), Ni (54.6), Co (26.2), Mn (1095), Cr (133), V (206), Hg (0.15), As (16.2), and Cd (3.08). Pb, Zn, and Cd had coefficients of variation greater than 100% and showed a high uneven distribution and spatial variability in the study area. Correlation coefficient analysis and principal component analysis (PCA) were used to quantify potential pollution sources. Results showed that Cu, Ni, Co, Mn, and V came from natural sources, whereas Pb, Zn, Hg, As, and Cd came from anthropogenic pollution sources. Geoaccumulation index and potential ecological risk indices were employed to study the pollution degree of PTEs, which revealed that Pb and Cd shared the greatest contamination and would pose serious ecological risks to the surrounding environment. The results of this study could help the local government managers to establish pollution control strategies and to secure food safety.

  4. TMEM59 potentiates Wnt signaling by promoting signalosome formation.

    Science.gov (United States)

    Gerlach, Jan P; Jordens, Ingrid; Tauriello, Daniele V F; van 't Land-Kuper, Ineke; Bugter, Jeroen M; Noordstra, Ivar; van der Kooij, Johanneke; Low, Teck Y; Pimentel-Muiños, Felipe X; Xanthakis, Despina; Fenderico, Nicola; Rabouille, Catherine; Heck, Albert J R; Egan, David A; Maurice, Madelon M

    2018-04-09

    Wnt/β-catenin signaling controls development and adult tissue homeostasis by regulating cell proliferation and cell fate decisions. Wnt binding to its receptors Frizzled (FZD) and low-density lipoprotein-related 6 (LRP6) at the cell surface initiates a signaling cascade that leads to the transcription of Wnt target genes. Upon Wnt binding, the receptors assemble into large complexes called signalosomes that provide a platform for interactions with downstream effector proteins. The molecular basis of signalosome formation and regulation remains elusive, largely due to the lack of tools to analyze its endogenous components. Here, we use internally tagged Wnt3a proteins to isolate and characterize activated, endogenous Wnt receptor complexes by mass spectrometry-based proteomics. We identify the single-span membrane protein TMEM59 as an interactor of FZD and LRP6 and a positive regulator of Wnt signaling. Mechanistically, TMEM59 promotes the formation of multimeric Wnt-FZD assemblies via intramembrane interactions. Subsequently, these Wnt-FZD-TMEM59 clusters merge with LRP6 to form mature Wnt signalosomes. We conclude that the assembly of multiprotein Wnt signalosomes proceeds along well-ordered steps that involve regulated intramembrane interactions. Copyright © 2018 the Author(s). Published by PNAS.

  5. Removal potential of toxic 2378-substituted PCDD/F from incinerator flue gases by waste-derived activated carbons.

    Science.gov (United States)

    Hajizadeh, Yaghoub; Onwudili, Jude A; Williams, Paul T

    2011-06-01

    The application of activated carbons has become a commonly used emission control protocol for the removal or adsorption of persistent organic pollutants from the flue gas streams of waste incinerators. In this study, the 2378-substituted PCDD/F removal efficiency of three types of activated carbons derived from the pyrolysis of refuse derived fuel, textile waste and scrap tyre was investigated and compared with that of a commercial carbon. Experiments were carried out in a laboratory scale fixed-bed reactor under a simulated flue gas at 275°C with a reaction period of four days. The PCDD/F in the solid matrices and exhaust gas, were analyzed using gas chromatography coupled with a triple quadrupole mass spectrometer. In the absence of activated carbon adsorbent, there was a significant increase in the concentration of toxic PCDD/F produced in the reacted flyash, reaching up to 6.6 times higher than in the raw flyash. In addition, there was a substantial release of PCDD/F into the gas phase, which was found in the flue gas trapping system. By application of the different commercial, refuse derived fuel, textile and tyre activated carbons the total PCDD/F toxic equivalent removal efficiencies in the exhaust gas stream were 58%, 57%, 64% and 52%, respectively. In general, the removal of the PCDDs was much higher with an average of 85% compared to PCDFs at 41%. Analysis of the reacted activated carbons showed that there was some formation of PCDD/F, for instance, a total of 60.6 μg I-TEQ kg(-1) toxic PCDD/F was formed in the refuse derived fuel activated carbon compared to 34 μg I-TEQ kg(-1) in the commercial activated carbon. The activated carbons derived from the pyrolysis of waste, therefore, showed good potential as a control material for PCDD/F emissions in waste incinerator flue gases. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Towards reducing DBP formation potential of drinking water by favouring direct ozone over hydroxyl radical reactions during ozonation.

    Science.gov (United States)

    De Vera, Glen Andrew; Stalter, Daniel; Gernjak, Wolfgang; Weinberg, Howard S; Keller, Jurg; Farré, Maria José

    2015-12-15

    When ozonation is employed in advanced water treatment plants to produce drinking water, dissolved organic matter reacts with ozone (O3) and/or hydroxyl radicals (OH) affecting disinfection byproduct (DBP) formation with subsequently used chlorine-based disinfectants. This study presents the effects of varying exposures of O3 and •OH on DBP concentrations and their associated toxicity generated after subsequent chlorination. DBP formation potential tests and in vitro bioassays were conducted after batch ozonation experiments of coagulated surface water with and without addition of tertiary butanol (t-BuOH, 10 mM) and hydrogen peroxide (H2O2, 1 mg/mg O3), and at different pH (6-8) and transferred ozone doses (0-1 mg/mg TOC). Although ozonation led to a 24-37% decrease in formation of total trihalomethanes, haloacetic acids, haloacetonitriles, and trihaloacetamides, an increase in formation of total trihalonitromethanes, chloral hydrate, and haloketones was observed. This effect however was less pronounced for samples ozonated at conditions favoring molecular ozone (e.g., pH 6 and in the presence of t-BuOH) over •OH reactions (e.g., pH 8 and in the presence of H2O2). Compared to ozonation only, addition of H2O2 consistently enhanced formation of all DBP groups (20-61%) except trihalonitromethanes. This proves that •OH-transformed organic matter is more susceptible to halogen incorporation. Analogously, adsorbable organic halogen (AOX) concentrations increased under conditions that favor •OH reactions. The ratio of unknown to known AOX, however, was greater at conditions that promote direct O3 reactions. Although significant correlation was found between AOX and genotoxicity with the p53 bioassay, toxicity tests using 4 in vitro bioassays showed relatively low absolute differences between various ozonation conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Paraquat Toxicity on Root Nodule Formation on Macroptiliuma tropurpureum Urb. and Its Corelation with Population of Rhizobium sp.

    Directory of Open Access Journals (Sweden)

    Erni Martani

    2004-12-01

    Full Text Available This study was designed to investigate the paraquat toxicity toward root nodulation by Rhizobium on Macroptilium atropurpureum as an indicator plant. The legume was grown in Thornton medium treated with several concentrations of paraquat and inoculated with R.japonicum 143 (Rj-143 or Rhizobium sp. C-1.1. These bacteria represent cross-inoculation of soybean and cover-crops legumes, respectively. Nodule formation and Rhizobium population were measured periodically. At the end of planting time, nitrogenase activity of the nodules was analysis based on ARA (Acethylene Reduction Analysis method. The results showed that nodules in plants inoculated with Rhizobium without addition paraquat, were formed within four weeks. There was no nodulation when paraquat was added. Paraquat was toxic to the plant, causing chlorosis, stunting, drying of the plant tissues, and death. The symptoms were detected at the second week after planting time. Paraquat also decreased Rhizobium population from 10^6 to 10^2 or 10^1 CFU/mL at 40 and 100 pp, respectively. These results depicted that paraquat disturbed the plant before nodulation, and at the same time Rhizobium populatin decreased until below minimal population required for nodulation. Therefore, the process of nodulation was disturbed, and in some treatments there was nodulation. It was concluded that paraquat was toxic to both plant and the Rhizobium, which cause nodulation failure.

  8. Radon potential, geologic formations, and lung cancer risk

    Directory of Open Access Journals (Sweden)

    Ellen J. Hahn

    2015-01-01

    Conclusion: Radon potential maps that account for geologic factors and observed radon values may be superior to using observed radon values only. Knowing radon-prone areas could help target population-based lung cancer prevention interventions given the inequities that exist related to radon.

  9. Formation of aqueous-phase α-hydroxyhydroperoxides (α-HHP: potential atmospheric impacts

    Directory of Open Access Journals (Sweden)

    R. Zhao

    2013-06-01

    Full Text Available The focus of this work is on quantifying the degree of the aqueous-phase formation of α-hydroxyhydroperoxides (α-HHPs via reversible nucleophilic addition of H2O2 to aldehydes. Formation of this class of highly oxygenated organic hydroperoxides represents a poorly characterized aqueous-phase processing pathway that may lead to enhanced SOA formation and aerosol toxicity. Specifically, the equilibrium constants of α-HHP formation have been determined using proton nuclear-magnetic-resonance (1H NMR spectroscopy and proton-transfer-reaction mass spectrometry (PTR-MS. Significant α-HHP formation was observed from formaldehyde, acetaldehyde, propionaldehyde, glycolaldehyde, glyoxylic acid, and methylglyoxal, but not from methacrolein and ketones. Low temperatures enhanced the formation of α-HHPs but slowed their formation rates. High inorganic salt concentrations shifted the equilibria toward the hydrated form of the aldehydes and slightly suppressed α-HHP formation. Using the experimental equilibrium constants, we predict the equilibrium concentration of α-HHPs to be in the μM level in cloud water, but it may also be present in the mM level in aerosol liquid water (ALW, where the concentrations of H2O2 and aldehydes can be high. Formation of α-HHPs in ALW may significantly affect the effective Henry's law constants of H2O2 and aldehydes but may not affect their gas-phase levels. The photochemistry and reactivity of this class of atmospheric species have not been studied.

  10. Potentially toxic elements in lignite and its combustion residues from a power plant.

    Science.gov (United States)

    Ram, L C; Masto, R E; Srivastava, N K; George, J; Selvi, V A; Das, T B; Pal, S K; Maity, S; Mohanty, D

    2015-01-01

    The presence of potentially toxic elements in lignite and coal is a matter of global concern during energy extraction from them. Accordingly, Barsingsar lignite from Rajasthan (India), a newly identified and currently exploited commercial source of energy, was evaluated for the presence of these elements and their fate during its combustion. Mobility of these elements in Barsingsar lignite and its ashes from a power plant (Bikaner-Nagaur region of Thar Desert, India) is presented in this paper. Kaolinite, quartz, and gypsum are the main minerals in lignite. Both the fly ash and bottom ash of lignite belong to class-F with SiO₂ > Al₂O₃ > CaO > MgO. Both the ashes contain quartz, mullite, anhydrite, and albite. As, In, and Sr have higher concentration in the feed than the ashes. Compared to the feed lignite, Ba, Co, U, Cu, Cd, and Ni are enriched (10-5 times) in fly ash and Co, Pb, Li, Ga, Cd, and U in bottom ash (9-5 times). Earth crust-normalization pattern showed enrichment of Ga, U, B, Ag, Cd, and Se in the lignite; Li, Ba, Ga, B, Cu, Ag, Cd, Hg, Pb, and Se, in fly ash; and Li, Sr, Ga, U, B, Cu, Ag, Cd, Pb, and Se in bottom ash. Hg, Ag, Zn, Ni, Ba, and Se are possibly associated with pyrite. Leaching test by toxicity characteristic leaching procedure (TCLP) showed that except B all the elements are within the safe limits prescribed by Indian Standards.

  11. Potential hazards of toxic metals found in toothpastes commonly used in Nigeria.

    Science.gov (United States)

    Orisakwe, Orish Ebere; Okolo, Kenneth Obinna; Igweze, Zelinjo Nkeiruka; Ajaezi, Godwin Chukwuebuka; Udowelle, Nnaemeka Arinze

    2016-01-01

    Toothpastes have multi-functional configurations as oral care products. They can however constitute a pos- sible source, amongst others, of toxic metal exposure in public health. Indeed, the public health impact of personal hygiene and consumer products is largely unknown. To determine the level of toxic metals (lead, cadmium, cobalt, chromium, nickel) in toothpastes available in Nigeria, (home produced and imported), and assess the potential risk to the people. The samples of toothpastes commonly used in Nigeria were tested. Using a market basket protocol thirty five different brands of toothpaste were used. Samples were digest by addition of 10 mL mixture of conc. nitric and hydrochloric acids (HCl:HNO(3), 3:1), followed by heating to dryness. 20 mL deionized water was added, stirred and filtered. The filtrate was made up in standard volumetric flask and lead, cadmium, chromium, cobalt and nickel concentrations were determined using the atomic absorption spectrophotometry 205A. The daily intake of metals and target hazard quotient (THQ) were then calculated. Pepsodent and Flodent had the highest levels of lead at respectively 23.575 and 18.092 mg/kg while Colgate Herbal had the highest nickel of 18.535 mg/kg. The daily intake estimates of all imported toothpaste samples were below the stated upper limits (UL). All target hazard quotients were also found to be below one. Although the UL, THQ and daily intake rates were all normal, the high levels of lead in some of the tooth- pastes an important concern to public health suggesting that pre-marketing safety studies of toothpastes may be worthwhile for the regulatory authorities.

  12. In Vivo Toxicity Assessment of Occupational Components of the Carbon Nanotube Life Cycle To Provide Context to Potential Health Effects.

    Science.gov (United States)

    Bishop, Lindsey; Cena, Lorenzo; Orandle, Marlene; Yanamala, Naveena; Dahm, Matthew M; Birch, M Eileen; Evans, Douglas E; Kodali, Vamsi K; Eye, Tracy; Battelli, Lori; Zeidler-Erdely, Patti C; Casuccio, Gary; Bunker, Kristin; Lupoi, Jason S; Lersch, Traci L; Stefaniak, Aleksandr B; Sager, Tina; Afshari, Aliakbar; Schwegler-Berry, Diane; Friend, Sherri; Kang, Jonathan; Siegrist, Katelyn J; Mitchell, Constance A; Lowry, David T; Kashon, Michael L; Mercer, Robert R; Geraci, Charles L; Schubauer-Berigan, Mary K; Sargent, Linda M; Erdely, Aaron

    2017-09-26

    Pulmonary toxicity studies on carbon nanotubes focus primarily on as-produced materials and rarely are guided by a life cycle perspective or integration with exposure assessment. Understanding toxicity beyond the as-produced, or pure native material, is critical, due to modifications needed to overcome barriers to commercialization of applications. In the first series of studies, the toxicity of as-produced carbon nanotubes and their polymer-coated counterparts was evaluated in reference to exposure assessment, material characterization, and stability of the polymer coating in biological fluids. The second series of studies examined the toxicity of aerosols generated from sanding polymer-coated carbon-nanotube-embedded or neat composites. Postproduction modification by polymer coating did not enhance pulmonary injury, inflammation, and pathology or in vitro genotoxicity of as-produced carbon nanotubes, and for a particular coating, toxicity was significantly attenuated. The aerosols generated from sanding composites embedded with polymer-coated carbon nanotubes contained no evidence of free nanotubes. The percent weight incorporation of polymer-coated carbon nanotubes, 0.15% or 3% by mass, and composite matrix utilized altered the particle size distribution and, in certain circumstances, influenced acute in vivo toxicity. Our study provides perspective that, while the number of workers and consumers increases along the life cycle, toxicity and/or potential for exposure to the as-produced material may greatly diminish.

  13. Formation of v-shaped potentials. [auroral zone electric fields

    Science.gov (United States)

    Thiemann, H.; Singh, N.; Schunk, R. W.

    1983-01-01

    The V-shaped potential structures formed by the injection of a non-neutral electron current into a cold background plasma were simulated numerically. The injection disturbs the initial quasi-neutral plasma, leading to the excitation of strong turbulences which heat the plasma. This leads to expulsion of the plasma from the simulation region. Due to ambipolar electric fields the current injection is interrupted and the initial background plasma is extracted from the system. A particle composition with the characteristics of the two plasma reservoirs now represents the plasma in the simulation region. The interaction of the electron beam with this plasma excites turbulences of smaller amplitudes. A nearly constant time averaged potential drop with nonstationary distribution develops across the system. Single and multiple double layers may form for the duration of one ion plasma period.

  14. Geochemical investigations of potentially toxic trace elements in urban sediments of Idrija

    Directory of Open Access Journals (Sweden)

    Špela Bavec

    2015-12-01

    Full Text Available Urban areas and associated human activities (industry, traffi, processes of mining and ore extracting, etc. have induced anthropogenic emissions of potentially toxic trace elements (PTTE, which can present risk to living organisms and ecosystems in case of enriched levels. An example of such area in Slovenia is the Idrija town, the central part of the second largest Hg mining district in the world, which is heavily contaminated with Hg in all environmental compartments. The knowledge about levels and distribution of other PTTE in Idrija is very limited due to the outstanding Hg related problems. In this study the geochemical investigation of PTTE (As, Cd, Co, Cr, Cu, Mo, Ni, Pb and Zn was performed in urban stream and road sediments of Idrija town for the fist time. In addition, solid phases of PTTE were observed using SEM/EDS and their potential sources were assessed. The results show that the levels of PTTE in urban stream and road sediments are mostly below international guidelines, except for Cu some high values were measured in road sediments. The highest Cu level was determined in the vicinity of a commutator production industry. The associations of Cu with other elements in solid phases are very diverse, which is why the analyses could not reveal the specifi source of high Cu levels.

  15. Formation of 2-alkylcyclobutanones in fat-containing irradiated food and evaluation of their toxicity

    International Nuclear Information System (INIS)

    Todoriki, Setsuko

    2003-01-01

    2-Alkylcyclobutanones (2-ACB) is unique radiolytic product which is produced by decomposition of triglyceride in fat of food. The effects of 2-ACB on body is not decided. Detection of 2-ACB in food and apply it to determination of irradiated food was studied at the first time by M.H.Stevenson in 1990. The detection methods and the detection results are explained. Nine toxicity tests of 2-ACB were summarized, for examples, genotoxic properties of 2-dodecylcyclobutanone, markers for an irradiation treatment in fat-containing food and induction of oxidative DNA damage by cyclobutanones generated by irradiation of fat-containing food. In WHO (World Health Organization) Statement on 2-Dodecylcyclobutanone and Related Compounds, March 2003, WHO concluded that 2-DCB and 2-ACB did not injure consumer's health on the basis of animal tests for long time and Ams tests. However, WHO expressed that it will promote the studies of toxicity and or carcinogenicity of 2-ACB and resume risk assessment of irradiated food, when new evidences of possibility of risk will be indicated. (S.Y.)

  16. Health risk implications of potentially toxic metals in street dust and surface soil of Tehran, Iran.

    Science.gov (United States)

    Dehghani, Sharareh; Moore, Farid; Keshavarzi, Behnam; Hale, Beverley A

    2017-02-01

    In this study a total of 30 street dusts and 10 surface soils were collected in the central district of Tehran and analyzed for major potentially toxic metals. Street dust was found to be greatly enriched in Sb, Pb, Cu and Zn and moderately enriched in Cr, Mn, Mo and Ni. Contamination of Cu, Sb, Pb and Zn was clearly related to anthropogenic sources such as brake wear, tire dust, road abrasion and fossil fuel combustion. Spatial distribution of pollution load index in street dust suggested that industries located south-west of the city intensify street dust pollution. Microscopic studies revealed six dominant group of morphological structures in calculation of the exposurethe street dusts and surface soils, with respect to different geogenic and anthropogenic sources. The BCR (the European Community Bureau of Reference) sequential extraction results showed that Sb, Ni, Mo, As and Cr bonded to silicates and sulfide minerals were highly resistant to dissolution. In contrast, Zn, Cd, and Mn were mostly associated with the exchangeable phase and thus would be easily mobilized in the environment. Cu was the most abundant metal in the reducible fraction, indicating its adsorption to iron and manganese oxy-hydroxides. Pb was equally extracted from exchangeable and reducible fractions. Anthropogenic sources related to traffic apparently play a small role in Cr, Ni and Mo contamination and dispersed them as bioavailable forms but with reduced mobility and bioavailablity due to high potential of complexation and adsorption to organic matter and iron and manganese oxy-hydroxides. Calculated Hazard Index (HI) suggests ingestion as the most important pathway for the majority of PTMs in children and dermal contact as the main exposure route for Cr, Cd and Sb for adults. The HIs and fractionation pattern of elements revealed Pb as the sole element that bears potential health risk in street dust and surface soil. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Formation of Toxic Iodinated Disinfection By-Products from Compounds Used in Medical Imaging

    Science.gov (United States)

    Iodinated X-ray contrast media (ICM) were investigated as a source of iodine in the formation of iodo-trihalomethane (iodo-THM) and iodo-acid disinfection byproducts (DBPs), both of which are highly genotoxic and/or cytotoxic in mammalian cells. ICM are widely used at medical cen...

  18. Human health and ecological toxicity potentials due to heavy metal content in waste electronic devices with flat panel displays

    International Nuclear Information System (INIS)

    Lim, Seong-Rin; Schoenung, Julie M.

    2010-01-01

    Display devices such as cathode-ray tube (CRT) televisions and computer monitors are known to contain toxic substances and have consequently been banned from disposal in landfills in the State of California and elsewhere. New types of flat panel display (FPD) devices, millions of which are now purchased each year, also contain toxic substances, but have not previously been systematically studied and compared to assess the potential impact that could result from their ultimate disposal. In the current work, the focus is on the evaluation of end-of-life toxicity potential from the heavy metal content in select FPD devices with the intent to inform material selection and design-for-environment (DfE) decisions. Specifically, the metals antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, mercury, molybdenum, nickel, selenium, silver, vanadium, and zinc in plasma TVs, LCD (liquid crystal display) TVs, LCD computer monitors and laptop computers are considered. The human health and ecotoxicity potentials are evaluated through a life cycle assessment perspective by combining data on the respective heavy metal contents, the characterization factors in the U.S. EPA Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI), and a pathway and impact model. Principal contributors to the toxicity potentials are lead, arsenic, copper, and mercury. Although the heavy metal content in newer flat panel display devices creates less human health toxicity potential than that in CRTs, for ecological toxicity, the new devices are worse, especially because of the mercury in LCD TVs and the copper in plasma TVs.

  19. Human health and ecological toxicity potentials due to heavy metal content in waste electronic devices with flat panel displays.

    Science.gov (United States)

    Lim, Seong-Rin; Schoenung, Julie M

    2010-05-15

    Display devices such as cathode-ray tube (CRT) televisions and computer monitors are known to contain toxic substances and have consequently been banned from disposal in landfills in the State of California and elsewhere. New types of flat panel display (FPD) devices, millions of which are now purchased each year, also contain toxic substances, but have not previously been systematically studied and compared to assess the potential impact that could result from their ultimate disposal. In the current work, the focus is on the evaluation of end-of-life toxicity potential from the heavy metal content in select FPD devices with the intent to inform material selection and design-for-environment (DfE) decisions. Specifically, the metals antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead, mercury, molybdenum, nickel, selenium, silver, vanadium, and zinc in plasma TVs, LCD (liquid crystal display) TVs, LCD computer monitors and laptop computers are considered. The human health and ecotoxicity potentials are evaluated through a life cycle assessment perspective by combining data on the respective heavy metal contents, the characterization factors in the U.S. EPA Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI), and a pathway and impact model. Principal contributors to the toxicity potentials are lead, arsenic, copper, and mercury. Although the heavy metal content in newer flat panel display devices creates less human health toxicity potential than that in CRTs, for ecological toxicity, the new devices are worse, especially because of the mercury in LCD TVs and the copper in plasma TVs. Copyright (c) 2009 Elsevier B.V. All rights reserved.

  20. Formation and development of hightechnology export corporate potential

    Directory of Open Access Journals (Sweden)

    Yevgen Panchenko

    2015-06-01

    Full Text Available This paper investigates the essence and peculiarities of high-Technology products exports in conditions of global competition with performed classification of its models on a corporate level. Peculiarities of corporate motivation of exporting high-technology products have been determined. Interconnection between innovation management system in transnational corporations and their capabilities of strengthening their competitive positions on world markets of high-technology products has been shown. Tendencies of fixing studies and developments during the last decade of leading companies, along with their influence on corporate innovative potential have been studied. On the example of aerospace sector of Ukraine, possibilities of strengthening the influence of high-technology export on rising of national economy international competitiveness have been determined. The need has been proved, and the ways have been shown for attraction of international investments into hightechnology sectors of Ukrainian economy through improvement of business conduct area, defense of intellectual property rights, and development of cooperation between national and transnational companies. Directions of use of integration factors of rising of volumes of export of high-technology Ukrainian products on the basis of developing cooperation of national enterprises with Russian partners have been shown.

  1. Evaluation of potential relationships between benthic community structure and toxic metals in Laizhou Bay.

    Science.gov (United States)

    Wu, Bin; Song, Jinming; Li, Xuegang

    2014-10-15

    The objective of the present study was to examine the relationships between benthic community structure and toxic metals using bivariate/multivariate techniques at 17 sediment locations in Laizhou Bay, North China. Sediment chemical data were evaluated against geochemical background values and sediment quality guidelines, which identified Cu and As as contaminants of concern with a moderate potential for adverse effects. Benthic community data were subjected to non-metric multidimensional scaling, which generated four groups of stations. Spearman rank correlation was then employed to explore the relationships between the major axes of heavy metals and benthic community structure. However, weak and insignificant correlations were found between these axes, indicating that contaminants of concern may not be the primary explanatory factors. Polychaeta were abundant in southern Laizhou Bay, serving as a warning regarding the health status of the ecosystem. Integrated sediment quality assessment showed sediments from northern central locations were impaired, displaying less diverse benthos and higher metal contamination. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Plant-soil distribution of potentially toxic elements in response to elevated atmospheric CO2.

    Science.gov (United States)

    Duval, Benjamin D; Dijkstra, Paul; Natali, Susan M; Megonigal, J Patrick; Ketterer, Michael E; Drake, Bert G; Lerdau, Manuel T; Gordon, Gwyneth; Anbar, Ariel D; Hungate, Bruce A

    2011-04-01

    The distribution of contaminant elements within ecosystems is an environmental concern because of these elements' potential toxicity to animals and plants and their ability to hinder microbial ecosystem services. As with nutrients, contaminants are cycled within and through ecosystems. Elevated atmospheric CO2 generally increases plant productivity and alters nutrient element cycling, but whether CO2 causes similar effects on the cycling of contaminant elements is unknown. Here we show that 11 years of experimental CO2 enrichment in a sandy soil with low organic matter content causes plants to accumulate contaminants in plant biomass, with declines in the extractable contaminant element pools in surface soils. These results indicate that CO2 alters the distribution of contaminant elements in ecosystems, with plant element accumulation and declining soil availability both likely explained by the CO2 stimulation of plant biomass. Our results highlight the interdependence of element cycles and the importance of taking a broad view of the periodic table when the effects of global environmental change on ecosystem biogeochemistry are considered.

  3. Morphology-based mammalian stem cell tests reveal potential developmental toxicity of donepezil.

    Science.gov (United States)

    Lau, Caroline G Y; Marikawa, Yusuke

    2014-11-01

    Various compounds, including therapeutic drugs, can adversely impact the survival and development of embryos in the uterus. Identification of such development-interfering agents is a challenging task, although multi-angle approaches--including the use of in vitro toxicology studies involving embryonic stem cells--should alleviate some of the current difficulties. In the present study, we utilized the in vitro elongation of embryoid bodies (EBs) derived from mouse embryonal carcinoma stem cell line P19C5 as a model of early embryological events, specifically that of gastrulation and axial patterning. From our study, we identified donepezil, a medication indicated for the management of Alzheimer's disease, as a potential developmental toxicant. The extent of P19C5 EB axial elongation was diminished by donepezil in a dose-dependent manner. Although donepezil is a known inhibitor of acetylcholinesterase, interference of elongation was not mediated through this enzyme. Quantitative reverse-transcriptase PCR revealed that donepezil altered the expression pattern of a specific set of developmental regulator genes involved in patterning along the anterior-posterior body axis. When tested in mouse whole embryo culture, donepezil caused morphological abnormalities including impaired somitogenesis. Donepezil also diminished elongation morphogenesis of EBs generated from human embryonic stem cells. These results suggest that donepezil interferes with axial elongation morphogenesis of early embryos by altering the expression pattern of regulators of axial development. © 2014 Wiley Periodicals, Inc.

  4. The potential DNA toxic changes among workers exposed to antimony trioxide.

    Science.gov (United States)

    El Shanawany, Safaa; Foda, Nermine; Hashad, Doaa I; Salama, Naglaa; Sobh, Zahraa

    2017-05-01

    Occupational exposure to antimony has gained much interest when specific toxic effects were noticed among workers processing antimony. Thus, the aim of the present work was to investigate the potential DNA oxidative damage occurring among Egyptian workers occupationally exposed to antimony trioxide. The study was conducted on 25 subjects exposed to antimony trioxide while working in the polymerization process of polyester in Misrayon and Polyester Fiber Company, KafrEldawwar, Beheira, Egypt. Urinary antimony levels were assessed using inductive coupled plasma-optical emission spectrometry (ICP-OES) and considered as a biological exposure index. DNA damage and total oxidant capacity (TOC) were assessed using ELISA. DNA damage was detected in the form of increased apurinic/apyrimidinic (AP) sites among antimony trioxide-exposed workers compared to control subjects, but it could not be explained by oxidative mechanisms due to lack of significant correlation between DNA damage and measured TOC. Antimony trioxide might have a genotoxic impact on occupationally exposed workers which could not be attributed to oxidative stress in the studied cases.

  5. Nanoscale zero-valent iron-assisted soil washing for the removal of potentially toxic elements.

    Science.gov (United States)

    Boente, C; Sierra, C; Martínez-Blanco, D; Menéndez-Aguado, J M; Gallego, J R

    2018-05-15

    The present study focuses on soil washing enhancement via soil pretreatment with nanoscale zero-valent iron (nZVI) for the remediation of potentially toxic elements. To this end, soil polluted with As, Cu, Hg, Pb and Sb was partitioned into various grain sizes (500-2000, 125-500 and accounting correction considering the dilution effects caused by nanoparticle addition. As a result, remarkable recovery yields were obtained for Cu, Pb and Sb, which concentrated with the nZVI in the magnetically separated fraction (WHIMS tests) and underflow (hydrocyclone tests). In contrast, Hg, concentrated in the non-magnetic fraction and overflow respectively, while the behavior of As was unaltered by the nZVI pretreatment. All things considered, the addition of nZVI enhanced the efficiency of soil washing, particularly for larger fractions (125-2000 μm). The proposed methodology lays the foundations for nanoparticle utilization in soil washing operations. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Comparison of three sequential extraction protocols for the fractionation of potentially toxic metals in coastal sediments.

    Science.gov (United States)

    Oyeyiola, Aderonke Oluwabukola; Olayinka, Kehinde O; Alo, Babajide I

    2011-01-01

    In the determination of the best sequential extraction procedures (SEP) for the speciation of metals in sediment samples from the Lagos lagoon system, three sequential extraction procedures were compared for the fractionation of Cd, Cr, Cu, Pb, and Zn. The SEP compared included a modified Tessier's procedure carried out in five steps, while the two other procedures were the three-step original Community Bureau of Reference (BCR) and the modified BCR techniques (four steps). Quantification of the metal concentration was achieved with a flame atomic absorption spectrophotometer. The results obtained by the three methods were compared, and the modified BCR and Tessier SEP were found to extract more Cu, Cr, Pb, and Zn in the reducible phase and therefore a decrease in the oxidizable phase than the original BCR SEP. The most mobile elements were found to be Cd, Pb, and Zn. These are of environmental concern, as these potentially toxic metals could be easily released into the aquatic environment with consequent ingestion by aquatic organisms, thereby entering the food chain. The mass balance (percent recovery) was found to be between 85% and 115% in most cases. Prior to the comparison, the analytical performance of the laboratory was tested using a secondary reference material, GLAURM, using the three-step modified BCR procedure. The results showed high reliability of the analytical performance of the laboratory for all the metals considered.

  7. Potential biochemical and genetic toxicity of triclosan as an emerging pollutant on earthworms (Eisenia fetida).

    Science.gov (United States)

    Lin, Dasong; Zhou, Qixing; Xie, Xiujie; Liu, Yao

    2010-11-01

    Triclosan as an important antimicrobial agent is increasingly detected in the terrestrial environment as sewage sludge and reclaimed water are applied on land, but little is known about its effect on non-target soil organisms. In this study, biochemical responses including changes in the activity of catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST), and malondialdehyde (MDA) of the earthworm Eisenia fetida were examined in order to assess ecological toxicity of the chemical. The single-cell gel electrophoresis (SCGE) was also used to measure the potential genotoxicity of the chemical. The results showed that the activity of CAT and GST at the highest tested dose could be stimulated after a 2-d exposure, reaching 148% and 123% of that in the control, respectively. However, with prolonged exposure, the activity of CAT and GST at the highest tested dose was inhibited, falling to 47% and 33% of that in the control, respectively. Triclosan induced an increase in the activity of SOD, but no significant (p>0.05) changes were observed. The content of MDA was dependent both on the dose of triclosan and on the exposure duration. The comet assay demonstrated that triclosan treatments led to a dose-dependent DNA damage of E. fetida after exposures of 7 and 14 d. Our findings can suggest that triclosan has sublethal effects on E. fetida. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. The Response of Artificial Aging to Sorption Properties of Biochar for Potentially Toxic Heavy Metals

    Directory of Open Access Journals (Sweden)

    Frišták Vladimír

    2014-12-01

    Full Text Available This paper evaluates the effect of simulated conditions of artificial aging on sorption capacity of two types of biochar. These were produced by slow pyrolysis from different feedstock - beech wood chips (BC A and garden green waste residues (BC B. Cadmium served as a model for potentially toxic metals. Twenty freeze-thaw cycles were used to simulate physical aging. The determination of biochar physicochemical properties showed main changes in CEC and SA values of aged sorbents. The maximum sorption capacities of aged BC A sorbent were higher by about 26 % and aged BC B sorbent by about 20% compared to Qmax of non-aged biochar. Qmax of aged BC B peaked at 9.4 mg g-1 whereas BC A sorbed significantly less Cd. FT-IR analyses confirmed the changes in structural composition and content of functional groups on biochar surfaces. The artificial physical aging model was assessed as an efficient tool for investigation of natural weathering conditions.

  9. TDP-43 Potentiates Alpha-synuclein Toxicity to Dopaminergic Neurons in Transgenic Mice

    Science.gov (United States)

    Tian, Tian; Huang, Cao; Tong, Jianbin; Yang, Ming; Zhou, Hongxia; Xia, Xu-Gang

    2011-01-01

    TDP-43 and α-synuclein are two disease proteins involved in a wide range of neurodegenerative diseases. While TDP-43 proteinopathy is considered a pathologic hallmark of sporadic amyotrophic lateral sclerosis and frontotemporal lobe degeneration, α-synuclein is a major component of Lewy body characteristic of Parkinson's disease. Intriguingly, TDP-43 proteinopathy also coexists with Lewy body and with synucleinopathy in certain disease conditions. Here we reported the effects of TDP-43 on α-synuclein neurotoxicity in transgenic mice. Overexpression of mutant TDP-43 (M337V substitution) in mice caused early death in transgenic founders, but overexpression of normal TDP-43 only induced a moderate loss of cortical neurons in the transgenic mice at advanced ages. Interestingly, concomitant overexpression of normal TDP-43 and mutant α-synuclein caused a more severe loss of dopaminergic neurons in the double transgenic mice as compared to single-gene transgenic mice. TDP-43 potentiated α-synuclein toxicity to dopaminergic neurons in living animals. Our finding provides in vivo evidence suggesting that disease proteins such as TDP-43 and α-synuclein may play a synergistic role in disease induction in neurodegenerative diseases. PMID:21448284

  10. Cadmium-Induced Toxicity and the Hepatoprotective Potentials of Aqueous Extract of Jessiaea Nervosa Leaf

    Directory of Open Access Journals (Sweden)

    Ama Udu Ibiam

    2013-08-01

    Full Text Available Purpose: Hepatoprotective potentials of Jussiaea nervosa leaf extract against Cadmium-induced hepatotoxicity were investigated. Methods: Forty albino rats were randomly assigned into groups A-G with 4 rats in each of the groups A-F. Group A served as control and were given feed only while rats in groups B-F were orally exposed to varying concentrations of cadmium for six weeks. Effects of cadmium were most significant at 12 mg/Kg body weight (BW, and this dose was used for subsequent test involving oral administration of Jussiaea nervosa leaf extracts. In this segment, group G (n= 16 was sub-divided into four: G1-G4, with each sub-group containing four rats. Rats in sub-group G1 were given cadmium and feed only and served as positive control. Rats in sub-groups G2, G3, and G4 were given cadmium and 20, 50 and 100g/kg BW of Jussiaea nervosa extract, respectively, for six weeks. Blood and liver were analysed using standard laboratory techniques and methods. Results: Liver function parameters (ALT, AST, ALP, bilirubin were significantly (p<0.05 elevated in exposed rats in comparison to the controls, except for total protein and albumin, which were significantly decreased. Histopathological assessment reveals renal pathology in exposed rats in sharp contrast with the controls. Jussiaea nervosa extract however lowered the values of liver function parameters with 100mg/Kg BW dose producing the highest ameliorative effects. Similarly, the serum albumin and total protein significantly (p<0.05 improved with normal liver architecture. Conclusion: The results show the hepatoprotective potentials of Jussiaea nervosa extract against Cd toxicity.

  11. Exposure to potentially toxic hydrocarbons and halocarbons released from the dialyzer and tubing set during hemodialysis.

    Science.gov (United States)

    Lee, Hyun Ji Julie; Meinardi, Simone; Pahl, Madeleine V; Vaziri, Nostratola D; Blake, Donald R

    2012-10-01

    Although much is known about the effect of chronic kidney failure and dialysis on the composition of solutes in plasma, little is known about their impact on the composition of gaseous compounds in exhaled breath. This study was designed to explore the effect of uremia and the hemodialysis (HD) procedure on the composition of exhaled breath. Breath samples were collected from 10 dialysis patients immediately before, during, and after a dialysis session. To determine the potential introduction of gaseous compounds from dialysis components, gasses emitted from dialyzers, tubing set, dialysate, and water supplies were collected. Prospective cohort study. 10 HD patients and 10 age-matched healthy individuals. Predictors include the dialyzers, tubing set, dialysate, and water supplies before, during, and after dialysis. Changes in the composition of exhaled breath. A 5-column/detector gas chromatography system was used to measure hydrocarbon, halocarbon, oxygenate, and alkyl nitrate compounds. Concentrations of 14 hydrocarbons and halocarbons in patients' breath rapidly increased after the onset of the HD treatment. All 14 compounds and 5 others not found in patients' breath were emitted from the dialyzers and tubing sets. Contrary to earlier reports, exhaled breath ethane concentrations in our dialysis patients were virtually unchanged during the HD treatment. Single-center study with a small sample size may limit the generalizability of the findings. The study documented the release of several potentially toxic hydrocarbons and halocarbons to patients from the dialyzer and tubing sets during the HD procedure. Because long-term exposure to these compounds may contribute to the morbidity and mortality in dialysis population, this issue should be considered in the manufacturing of the new generation of dialyzers and dialysis tubing sets. Copyright © 2012 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

  12. Temporal dissolution of potentially toxic elements from silver smelting slag by synthetic environmental solutions.

    Science.gov (United States)

    Ash, Christopher; Borůvka, Luboš; Tejnecký, Václav; Šebek, Ondřej; Nikodem, Antonín; Drábek, Ondřej

    2013-11-15

    Waste slag which is created during precious metal smelting contains high levels of potentially toxic elements (PTE) which can be mobilised from unconfined deposits into the local environment. This paper examines the extractability of selected PTE (Pb, Zn, Cd, Mn) from slag samples by synthetic solutions designed to replicate those in the environment. Extracting agents were used to replicate potential leaching scenarios which are analogous to natural chemical weathering. Slag was submersed in a rainwater simulation solution (RSS), weak citric acid solution (representing rhizosphere secretions) and control solutions (deionised water) for a one month period with solution analyses made at intervals of 1, 24, 168 and 720 h. In 1 mM citric acid, dissolution of Cd and Zn showed little change with time, although for Zn the initial dissolution was considerable. Lead in citric acid was characterized by overall poor extractability. Mn solubility increased until an equilibrium state occurred within 24 h. The solubility of studied metals in citric acid can be characterized by a short time to equilibrium. RSS proved to be an effective solvent that, unlike citric acid solution, extracted increasing concentrations of Cd, Mn and Zn with time. Solubility of Pb in RSS was again very low. When taken as a proportion of a single 2 M HNO3 extraction which was applied to slag samples, Cd was the element most readily leached into RSS and control samples. In both studied solvents, slag heterogeneity is prominent in the case of Cd and Zn solubility. Contact time with solvent appears to be an important variable for the release of PTE from slag into solution. The purpose of this study was to provide insight into the environmental chemical dissolution of PTE from slag, which causes their enrichment in surrounding soils and surface waters. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Toxicity of neem's oil, a potential biocide against the invasive mussel Limnoperna fortunei (Dunker 1857

    Directory of Open Access Journals (Sweden)

    Patricio J. Pereyra

    2012-12-01

    Full Text Available The golden mussel Limnoperna fortunei (Dunker 1857 is one of the most distributed Nuisance Invasive Species (NIS in South America, and a threat of great concern for the industry of the area. In this study, we carried out toxicity tests made with a Neem's oil solution with L. fortunei larvae and benthonic adults (7, 13 and 19 ± 1 mm. Tests with non-target species (Daphnia magna, Lactuca sativa and Cnesterodon decemmculatus were also made with the aim to evaluate the potential toxicity of the Neem's solution in the environment. The LC100 of Neem's solution obtained for larvae was 500 µl/L, a value much higher than the one obtained for D. magna and C. decemmaculatus. Thus, we recommend that it should not be used in open waters. However, since the adults were killed in 72 h and the larvae in 24 h, this product can be used in closed systems, in man-made facilities.O Mexilhão dourado Limnoperna fortunei (Dunker 1857 é uma das espécies invasoras melhor distribuídas na América do Sul, sendo motivo de grande preocupação para a indústria local. Neste estudo, nós realizamos ensaios de toxicidade de soluções de Óleo de Neem em larvas e adultos bentônicos de L. fortune (7, 13 e 19 ± 1 mm. Com o objetivo de avaliar o potencial tóxico do Óleo de Neem no ambiente também foram realizados testes com organismos não alvo (Daphnia magna, Lactuca sativa e Cnesterodon decemmculatus. A LC100 da solução de Neem para larvas foi 500 µl/L, um valor muito superior ao obtido para D. magna e C. decemmaculatus. Desta forma, nossa recomendação é que este óleo não deve ser utilizado em ambientes naturais abertos. No entanto, uma vez que os adultos morreram em 72h e as larvas em 24h, este produto pode ser utilizado em sistemas fechados construídos pelo homem.

  14. Ceriodaphnia dubia as a Potential Bio-Indicator for Assessing Acute Aluminum Oxide Nanoparticle Toxicity in Fresh Water Environment

    Science.gov (United States)

    Pakrashi, Sunandan; Dalai, Swayamprava; Humayun, Ahmed; Chakravarty, Sujay; Chandrasekaran, Natarajan; Mukherjee, Amitava

    2013-01-01

    Growing nanomaterials based consumer applications have raised concerns about their potential release into the aquatic ecosystems and the consequent toxicological impacts. So environmental monitoring of the nanomaterials in aqueous systems becomes imperative. The current study reveals the potential of Ceriodaphnia dubia (C. dubia) as a bio-indicator for aluminum oxide nanoparticles in a fresh water aquatic ecosystem where it occupies an important ecological niche as a primary consumer. This study aims to investigate the aluminium oxide nanoparticle induced acute toxicity on Ceriodaphnia dubia in a freshwater system. The bioavailability of the aluminum oxide nanoparticles has been studied with respect to their aggregation behavior in the system and correlated with the toxicity endpoints. The oxidative stress generated by the particles contributed greatly toward their toxicity. The crucial role of leached aluminium ion mediated toxicity in the later phases (48 h and 72 h) in conjunction with the effects from the nano-sized particles in the initial phases (24 h) puts forth the dynamics of nanotoxicity in the test system. The internalization of nanoparticles (both gross and systemic uptake) as substantiated through the transmission electron microscopy (TEM) and inductively coupled plasma optical emission spectral (ICP-OES) analysis was another major contributor toward acute toxicity. Concluding the present study, Ceriodaphnia dubia can be a promising candidate for bio-monitoring the aluminium oxide nanoparticles in a fresh water system. PMID:24040143

  15. Ceriodaphnia dubia as a potential bio-indicator for assessing acute aluminum oxide nanoparticle toxicity in fresh water environment.

    Directory of Open Access Journals (Sweden)

    Sunandan Pakrashi

    Full Text Available Growing nanomaterials based consumer applications have raised concerns about their potential release into the aquatic ecosystems and the consequent toxicological impacts. So environmental monitoring of the nanomaterials in aqueous systems becomes imperative. The current study reveals the potential of Ceriodaphnia dubia (C. dubia as a bio-indicator for aluminum oxide nanoparticles in a fresh water aquatic ecosystem where it occupies an important ecological niche as a primary consumer. This study aims to investigate the aluminium oxide nanoparticle induced acute toxicity on Ceriodaphnia dubia in a freshwater system. The bioavailability of the aluminum oxide nanoparticles has been studied with respect to their aggregation behavior in the system and correlated with the toxicity endpoints. The oxidative stress generated by the particles contributed greatly toward their toxicity. The crucial role of leached aluminium ion mediated toxicity in the later phases (48 h and 72 h in conjunction with the effects from the nano-sized particles in the initial phases (24 h puts forth the dynamics of nanotoxicity in the test system. The internalization of nanoparticles (both gross and systemic uptake as substantiated through the transmission electron microscopy (TEM and inductively coupled plasma optical emission spectral (ICP-OES analysis was another major contributor toward acute toxicity. Concluding the present study, Ceriodaphnia dubia can be a promising candidate for bio-monitoring the aluminium oxide nanoparticles in a fresh water system.

  16. Development of Comparative Toxicity Potentials of TiO2Nanoparticles for Use in Life Cycle Assessment.

    Science.gov (United States)

    Ettrup, Kim; Kounina, Anna; Hansen, Steffen Foss; Meesters, Johannes A J; Vea, Eldbjørg B; Laurent, Alexis

    2017-04-04

    Studies have shown that releases of nanoparticles may take place through the life cycle of products embedding nanomaterials, thus resulting in potential impacts on ecosystems and human health. While several life cycle assessment (LCA) studies have assessed such products, only a few of them have quantitatively addressed the toxic impacts caused by released nanoparticles, thus leading to potential biases in their conclusions. Here, we address this gap and aim to provide a framework for calculating characterization factors or comparative toxicity potentials (CTP) for nanoparticles and derive CTP values for TiO 2 nanoparticles (TiO 2 -NP) for use in LCA. We adapted the USEtox 2.0 consensus model to integrate the SimpleBox4Nano fate model, and we populated the resulting model with TiO 2 -NP specific data. We thus calculated CTP values for TiO 2 nanoparticles for air, water, and soil emission compartments for freshwater ecotoxicity and human toxicity, both cancer effects and noncancer effects. Our results appeared plausible after benchmarking with CTPs for other nanoparticles and substances present in the USEtox database, while large differences were observed with CTP values for TiO 2 nanoparticles published in earlier studies. Assumptions, which were performed in those previous studies because of lack of data and knowledge at the time they were made, primarily explain such discrepancies. For future assessment of potential toxic impacts of TiO 2 nanoparticles in LCA studies, we therefore recommend the use of our calculated CTP.

  17. Potentially toxic element contamination in soil and accumulation in maize plants in a smelter area in Kosovo.

    Science.gov (United States)

    Nannoni, Francesco; Rossi, Sara; Protano, Giuseppe

    2016-06-01

    A biogeochemical field study was carried out in the industrial area of Kosovska Mitrovica in northern Kosovo, where agricultural soils were contaminated by potentially toxic elements due to smelting activity. Total and bioavailable contents of As, Cd, Co, Cu, Pb, Sb, U and Zn in soil and their concentrations in maize roots and grains were determined. Soil contamination by As, Cd, Cu, Pb, Sb and Zn was variable from slightly to highly contaminated soils and influenced both the bioavailable fraction and accumulation of these potentially toxic elements in maize tissues. The comparison between potentially toxic element concentrations in roots and grains indicated that maize is able to limit the transfer of non-essential elements to edible parts. The plant-to-soil bioconcentration indices suggested that the transfer of potentially toxic elements from soil to plant was predicted better by bioavailable concentrations than by the total contents. These indices further identified some competitions and interactions among these elements in root uptake and root-to-grain translocation.

  18. Bisphenol A alternatives in thermal paper from the Netherlands, Spain, Sweden and Norway. Screening and potential toxicity

    NARCIS (Netherlands)

    Björnsdotter, Maria K.; Jonker, Willem; Legradi, Jessica; Kool, Jeroen; Ballesteros-Gómez, Ana

    2017-01-01

    Thermal paper contains potentially toxic additives, such as bisphenol A (BPA), as a common color developer. Because of its known endocrine disrupting effects, structural analogues to BPA, such as bisphenol S (BPS), D-8 and Pergafast 201, have been used as alternatives, but little is known about the

  19. Human Pluripotent Stem Cell-Based Assay Predicts Developmental Toxicity Potential of ToxCast Chemicals (ACT meeting)

    Science.gov (United States)

    Worldwide initiatives to screen for toxicity potential among the thousands of chemicals currently in use require inexpensive and high-throughput in vitro models to meet their goals. The devTOX quickPredict platform is an in vitro human pluripotent stem cell-based assay used to as...

  20. Pore formation by human stefin B in its native and oligomeric states and the consequent amyloid induced toxicity.

    Directory of Open Access Journals (Sweden)

    Gregor eAnderluh

    2012-08-01

    Full Text Available It is well documented that amyloid forming peptides and proteins interact with membranes and that this correlates with cytotoxicity. To introduce the theme we give a brief description of some amyloidogenic proteins and note their similarities with pore forming toxins and cell penetrating peptides. Human stefin B, a member of the family of cystatins, is an amyloidogenic protein in vitro. This review describes our studies of the interaction of stefin B oligomers and prefibrillar aggregates with model membranes leading to pore formation. We have studied the interaction between human stefin B and artificial membranes of various compositions. We also have prepared distinct sizes and morphologies of stefin B prefibrillar states and assessed their toxicity. Furthermore, we have measured electrical currents through pores formed by stefin B prefibrillar oligomers in a planar lipid bilayer setup. We finally discuss the possible functional and pathological significance of such pores formed by human stefin B.

  1. Evaluate the potential environmental toxicity of quantum dots on ciliated protozoa by microcalorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Qi [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Huang, Shan, E-mail: huangs@whu.edu.cn [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China); Su, Wei [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); Li, Peiyuan [College of Pharmacy, Guangxi Traditional Chinese Medical University, Nanning 530001 (China); Liang, Zuocui; Ou, Jianzhen; Ma, Jianqiang [College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001 (China); Liu, Yi, E-mail: prof.liuyi@263.net [State Key Laboratory of Virology, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072 (China)

    2012-11-10

    Highlights: Black-Right-Pointing-Pointer The toxic effects of QDs to T. thermophila BF{sub 5} using a TAM air microcalorimeter. Black-Right-Pointing-Pointer QDs were acutely toxic for T. thermophila BF{sub 5} growth in a dose-dependent manner. Black-Right-Pointing-Pointer The toxicity of different ligands-capped QDs on T. thermophila BF{sub 5} was investigated. Black-Right-Pointing-Pointer QDs could be ingested by cells and affect the morphology of T. thermophila BF{sub 5}. - Abstract: In the present study, we evaluated the toxic effects of mercaptoacetic acid (MAA)-capped CdSe QDs and CdSe/ZnS QDs to particle-ingesting model ciliated protozoa Tetrahymena thermophila BF{sub 5} (T. thermophila BF{sub 5}) by using a TAM air isothermal microcalorimeter. These results suggested that both MAA-CdSe QDs and MAA-CdSe/ZnS QDs were indeed acutely toxic for T. thermophila BF{sub 5} growth in a dose-dependent manner, and the toxicities of both MAA-CdSe QDs and MAA-CdSe/ZnS QDs increased dramatically after UV irradiation due to the liberation of more toxic Cd{sup 2+}, which indicated that the toxicity of MAA-CdSe/ZnS QDs was less than that of MAA-CdSe QDs. Furthermore, the toxicity of different ligands-capped CdSe/ZnS QDs on T. thermophila BF{sub 5} was also investigated. The uptake of MAA-CdSe/ZnS QDs and adenosine 5 Prime -monophosphate (AMP)-CdSe/ZnS QDs by cells and the morphological change during the process of T. thermophila BF{sub 5} growth incubated with these QDs were further studied by fluorescence inverted microscopy.

  2. Cardiovascular and Hepatic Toxicity of Cocaine: Potential Beneficial Effects of Modulators of Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Manuela Graziani

    2016-01-01

    Full Text Available Oxidative stress (OS is thought to play an important role in the pharmacological and toxic effects of various drugs of abuse. Herein we review the literature on the mechanisms responsible for the cardiovascular and hepatic toxicity of cocaine with special focus on OS-related mechanisms. We also review the preclinical and clinical literature concerning the putative therapeutic effects of OS modulators (such as N-acetylcysteine, superoxide dismutase mimetics, nitroxides and nitrones, NADPH oxidase inhibitors, xanthine oxidase inhibitors, and mitochondriotropic antioxidants for the treatment of cocaine toxicity. We conclude that available OS modulators do not appear to have clinical efficacy.

  3. Cardiovascular and Hepatic Toxicity of Cocaine: Potential Beneficial Effects of Modulators of Oxidative Stress

    Science.gov (United States)

    Graziani, Manuela; Antonilli, Letizia; Togna, Anna Rita; Grassi, Maria Caterina; Badiani, Aldo; Saso, Luciano

    2016-01-01

    Oxidative stress (OS) is thought to play an important role in the pharmacological and toxic effects of various drugs of abuse. Herein we review the literature on the mechanisms responsible for the cardiovascular and hepatic toxicity of cocaine with special focus on OS-related mechanisms. We also review the preclinical and clinical literature concerning the putative therapeutic effects of OS modulators (such as N-acetylcysteine, superoxide dismutase mimetics, nitroxides and nitrones, NADPH oxidase inhibitors, xanthine oxidase inhibitors, and mitochondriotropic antioxidants) for the treatment of cocaine toxicity. We conclude that available OS modulators do not appear to have clinical efficacy. PMID:26823954

  4. UV-visible degradation of boscalid- structural characterization of photoproducts and potential toxicity using in silico tests

    International Nuclear Information System (INIS)

    Rifai, A.; Jaber, F.; Lassalle, Y.; Kinani, A.; Souissi, Y.; Clavaguera, C.; Bourcier, S.; Bouchonnet, St.

    2014-01-01

    RATIONALE: Boscalid is a carboximide fungicide mainly used for vineyard protection as well as for tomato, apple, blueberry and various ornamental cultivations. The structural elucidation of by-products arising from the UV-visible photodegradation of boscalid has been investigated by gas chromatography/multi-stage mass spectrometry (GC/MSn) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) couplings. The potential toxicities of transformation products were estimated by in silico calculations. METHODS: Aqueous solutions of boscalid were irradiated up to 150 min in a self-made reactor equipped with a mercury lamp. Analyses were carried out using a gas chromatograph coupled with an ion trap mass spectrometer operated in both electron ionization (EI) and chemical ionization (CI) modes and a liquid chromatograph coupled with a quadrupole time-of-flight (Q-TOF) mass spectrometer operated in electrospray ionization (ESI) mode. Multiple-stage collision-induced dissociation (CID) experiments were performed to establish dissociation pathways of ions. The QSAR (Quantitative Structure-Activity Relationship) T.E.S.T. program allowed the estimation of the toxicities of the by-products. RESULTS: Eight photoproducts were investigated. Chemical structures were proposed not only on the interpretation of multi-stage CID experiments, but also on kinetics data. These structures led us to suggest photodegradation pathways. Three photoproducts were finally detected in Lebanon in a real sample of grape leaves for which routine analysis had led to the detection of boscalid at 4 mg kg1. CONCLUSIONS: With one exception, the structures proposed for the photoproducts on the basis of mass spectra interpretation have not been reported in previous studies. In silico toxicity predictions showed that two photoproducts are potentially more toxic than the parent compound considering oral rat LD50 while five photoproducts may induce mutagenic toxicity. With the exception of one compound

  5. Menadione enhances oxyradical formation in earthworm extracts: vulnerability of earthworms to quinone toxicity

    International Nuclear Information System (INIS)

    Osman, A.M.; Besten, P.J. den; Noort, P.C.M. van

    2003-01-01

    NAD(P)H-cytochrome c reductase activities have been determined in the earthworms, L. rubellus and A. chlorotica, extracts. Menadione (0.35 mM, maximum concentration tested) was found to stimulate the rates of NADPH- and NADH-dependent cytochrome c reduction by three- and twofold, respectively. Superoxide dismutase (SOD) inhibited completely this menadione-mediated stimulation, suggesting that ·O 2 - is involved in the redox cycling of menadione. However, SOD had no effect on the basal activity (activity in the absence of quinone) in the case of NADH-dependent cytochrome c reduction, whereas it partially inhibited the basal activity of NADPH-cytochrome c reduction. This indicates direct electron transfer in the former case and the formation of superoxide anion in the latter. DT-diaphorase, measured as the dicumarol-inhibitable part of menadione reductase activity, was not detectable in the earthworms' extracts. In contrast, it was found that DT-diaphorase represents about 70% of the menadione reductase activities in the freshwater mussel, Dreissena polymorpha. The results of this work suggest that earthworms, compared with mussels, could be more vulnerable to oxidative stress from quinones due to lack, or very low level of DT-diaphorase, an enzyme considered to play a significant role in the detoxification of quinones. On the contrary, mussels have efficient DT-diaphorase, which catalyzes two-electron reduction of menadione directly to hydroquinone, thus circumventing the formation of semiquinone

  6. Chemical mixtures in untreated water from public-supply wells in the U.S.--occurrence, composition, and potential toxicity.

    Science.gov (United States)

    Toccalino, Patricia L; Norman, Julia E; Scott, Jonathon C

    2012-08-01

    Chemical mixtures are prevalent in groundwater used for public water supply, but little is known about their potential health effects. As part of a large-scale ambient groundwater study, we evaluated chemical mixtures across multiple chemical classes, and included more chemical contaminants than in previous studies of mixtures in public-supply wells. We (1) assessed the occurrence of chemical mixtures in untreated source-water samples from public-supply wells, (2) determined the composition of the most frequently occurring mixtures, and (3) characterized the potential toxicity of mixtures using a new screening approach. The U.S. Geological Survey collected one untreated water sample from each of 383 public wells distributed across 35 states, and analyzed the samples for as many as 91 chemical contaminants. Concentrations of mixture components were compared to individual human-health benchmarks; the potential toxicity of mixtures was characterized by addition of benchmark-normalized component concentrations. Most samples (84%) contained mixtures of two or more contaminants, each at concentrations greater than one-tenth of individual benchmarks. The chemical mixtures that most frequently occurred and had the greatest potential toxicity primarily were composed of trace elements (including arsenic, strontium, or uranium), radon, or nitrate. Herbicides, disinfection by-products, and solvents were the most common organic contaminants in mixtures. The sum of benchmark-normalized concentrations was greater than 1 for 58% of samples, suggesting that there could be potential for mixtures toxicity in more than half of the public-well samples. Our findings can be used to help set priorities for groundwater monitoring and suggest future research directions for drinking-water treatment studies and for toxicity assessments of chemical mixtures in water resources. Published by Elsevier B.V.

  7. Combustion Tests of Rocket Motor Washout Material: Focus on Air toxics Formation Potential and Asbestos Remediation

    Energy Technology Data Exchange (ETDEWEB)

    G. C. Sclippa; L. L. Baxter; S. G. Buckley

    1999-02-01

    The objective of this investigation is to determine the suitability of cofiring as a recycle / reuse option to landfill disposal for solid rocket motor washout residue. Solid rocket motor washout residue (roughly 55% aluminum powder, 40% polybutadiene rubber binder, 5% residual ammonium perchlorate, and 0.2-1% asbestos) has been fired in Sandia's MultiFuel Combustor (MFC). The MFC is a down-fired combustor with electrically heated walls, capable of simulating a wide range of fuel residence times and stoichiometries. This study reports on the fate of AP-based chlorine and asbestos from the residue following combustion.

  8. Assessment of toxic potential of Cerrado fruit seeds using Artemia salina bioassay

    Directory of Open Access Journals (Sweden)

    Raíza Cavalcante Fonseca

    2013-06-01

    Full Text Available Artemia salina bioassay was used to assess toxicity of seeds and kernels of Brazilian fruits from cerrado (central high plains region and other inner regions of the country. Water extracts of the kernels were filtered and added to Artemia cultures containing ten individuals per mL. Dose - response curves were constructed, and LD50 values were calculated. Pure potassium cyanide standard was used to draw a calibration curve for comparison to detect the presence of cyanide in the samples tested. Extracts of the seeds of araticum, mangaba, cagaita, jatobá, and tucumã were found toxic to Artemia salina, and some of the dose - response curves were very similar in shape to those obtained with pure potassium cyanide standards, while the samples of baru, cajá-manga, siriguela, trauma, and veludo showed no toxicity at all. The Guignard test, specific for cyanide detection, showed negative results in all toxic samples, suggesting the presence of other toxic compounds rather than cyanide. The comparison of araticum dose - response curve with those of other annonaceous fruits suggests the presence acetogenins as the main toxic compounds in the seeds. These results could be useful to prevent poisoning by industrial derivatives of the fruits studied.

  9. Potential toxic effects of glyphosate and its commercial formulations below regulatory limits.

    Science.gov (United States)

    Mesnage, R; Defarge, N; Spiroux de Vendômois, J; Séralini, G E

    2015-10-01

    Glyphosate-based herbicides (GlyBH), including Roundup, are the most widely used pesticides worldwide. Their uses have increased exponentially since their introduction on the market. Residue levels in food or water, as well as human exposures, are escalating. We have reviewed the toxic effects of GlyBH measured below regulatory limits by evaluating the published literature and regulatory reports. We reveal a coherent body of evidence indicating that GlyBH could be toxic below the regulatory lowest observed adverse effect level for chronic toxic effects. It includes teratogenic, tumorigenic and hepatorenal effects. They could be explained by endocrine disruption and oxidative stress, causing metabolic alterations, depending on dose and exposure time. Some effects were detected in the range of the recommended acceptable daily intake. Toxic effects of commercial formulations can also be explained by GlyBH adjuvants, which have their own toxicity, but also enhance glyphosate toxicity. These challenge the assumption of safety of GlyBH at the levels at which they contaminate food and the environment, albeit these levels may fall below regulatory thresholds. Neurodevelopmental, reproductive, and transgenerational effects of GlyBH must be revisited, since a growing body of knowledge suggests the predominance of endocrine disrupting mechanisms caused by environmentally relevant levels of exposure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Environmental contextualisation of potential toxic elements and polycyclic aromatic hydrocarbons in biochar

    International Nuclear Information System (INIS)

    Freddo, Alessia; Cai Chao; Reid, Brian J.

    2012-01-01

    Nine dissimilar biochars, produced from varying feedstock at different pyrolysis temperatures, are appraised with respect to concentrations of potentially toxic elements, specifically, metals, metalloids and polycyclic aromatic hydrocarbons (PAHs). Concentrations of the metals and metalloids varied with the following ranges (mg kg −1 ): 0.02–0.94, Cd; 0.12–6.48, Cr; 0.04–13.2, Cu; 0.1–1.37, Ni; 0.06–3.87, Pb; 0.94–207, Zn and 0.03–0.27, As. Σ 16 PAH concentrations (16 Environmental Protection Agency (EPA) PAHs) range between 0.08 mg kg −1 to 8.7 mg kg −1 . Subsequent comparison with background soil concentrations, concentration applied to the regulation of composted materials (Publicly Available Specification (PAS 100)) and European Union (EU) regulations relating to the application of sewage sludge to agricultural land suggest low risk associated with the concentrations of PTEs observed in biochar. Collectively, results suggest that environmental impacts attributable to metals, metalloids and PAHs associated with biochar following its application to soil are likely to be minimal. - Highlights: ► Concentrations of PTEs varied with feedstock and temperature of production. ► Of the PTEs Zn (0.94–207 mg kg −1 ) was of most priority. ► PTE levels did not infringe guidance values for compost or sewage sludge. ► Biochar ( −1 ) is unlikely to make any real difference to PTE concentrations in soil. - Environmental impacts attributable to metals, metalloids and PAHs associated with biochar following its application to soil are likely to be minimal.

  11. A quantum chemical based toxicity study of estimated reduction potential and hydrophobicity in series of nitroaromatic compounds.

    Science.gov (United States)

    Gooch, A; Sizochenko, N; Sviatenko, L; Gorb, L; Leszczynski, J

    2017-02-01

    Nitroaromatic compounds and the products of their degradation are toxic to bacteria, cells and animals. Various studies have been carried out to better understand the mechanism of toxicity of aromatic nitrocompounds and their relationship to humans and the environment. Recent data relate cytotoxicity of nitroaromatic compounds to their single- or two-electron enzymatic reduction. However, mechanisms of animal toxicity could be more complex. This work investigates the estimated reduction and oxidation potentials of 34 nitroaromatic compounds using quantum chemical approaches. All geometries were optimized with density functional theory (DFT) using the solvation model based on density (SMD) and polarizable continuum model (PCM) solvent model protocols. Quantitative structure-activity/property (QSAR/QSPR) models were developed using descriptors obtained from quantum chemical optimizations as well as the DRAGON software program. The QSAR/QSPR equations developed consist of two to four descriptors. Correlations have been identified between electron affinity (E LUMO ) and hydrophobicity (log P).

  12. Formation Control of Multirobot Based on I/O Feedback Linearization and Potential Function

    Directory of Open Access Journals (Sweden)

    Jie Dong

    2014-01-01

    Full Text Available Standard techniques of I/O linearization are widely applied to leader-follower approach for multirobot formation control. However general leader-follower approach cannot adapt to the environment with obstacles. Concerning that issue, a formation control method of multirobot system based on potential function is proposed in this paper, and a new control law is designed by choosing a proper potential function and employing Lyapunov stability theory, which stabilizes the formation of the multirobot system. We combine the method with a leader-follower approach to solve the problem that the latter cannot avoid obstacles. Simulation results are given to validate the method.

  13. The gas phase reaction of ozone with 1,3-butadiene: formation yields of some toxic products

    Science.gov (United States)

    Kramp, Franz; Paulson, Suzanne E.

    The formation yields of acrolein, 1,2-epoxy-3-butene and OH radicals have been measured from reaction of ozone with 1,3-butadiene at room temperature and atmosphere pressure. 1,3,5-Trimethyl benzene was added to scavenge OH radicals in measurements of product yields. In separate experiments, small quantities of 1,3,5-trimethyl benzene were added as a tracer for OH. Formation yields of acrolein of (52±7)%, 1,2-epoxy-3-butene of (3.1±0.5)% and OH radicals of (13±3)% were observed. In addition, the rate coefficient of the gas-phase reaction of ozone with 1,2-epoxy-3-butene was measured both directly and relative to propene, finding an average of (1.6±0.4)×10 -18 cm 3 molecule -1 s -1, respectively, at 296±2 K. The results are briefly discussed in terms of the effect of atmospheric processing on the toxicity of 1,3-butadiene.

  14. Chemosensory TRP channels in the respiratory tract: role in toxic lung injury and potential as "sweet spots" for targeted therapies.

    Science.gov (United States)

    Büch, Thomas; Schäfer, Eva; Steinritz, Dirk; Dietrich, Alexander; Gudermann, Thomas

    2013-01-01

    Acute toxic lung injury by reactive inhalational compounds is an important and still unresolved medical problem. Hazardous gases or vapors, e. g. chlorine, phosgene, sulfur mustard or methyl isocyanate, are released during occupational accidents or combustion processes and also represent a potential threat in terroristic scenarios. According to their broad-range chemical reactivity, the mechanism of lung injury evoked by these agents has long been described as rather unspecific. Consequently, therapeutic options are still restricted to symptomatic treatment. However, in recent years, ion channels of the transient receptor potential (TRP) family have been identified to act as specific sensor molecules expressed in the respiratory tract and to engage defined signaling pathways upon inhalational exposure to toxic challenges. These pulmonary receptor molecules have been primarily characterized in sensory neurons of the lung. However, chemosensory molecules are also expressed in non-neuronal cells, e.g. in the lung epithelium as well as in the pulmonary vasculature. Thus, activation of respiratory chemosensors by toxic inhalants promotes a complex signaling network directly or indirectly regulating pulmonary blood flow, the integrity of the epithelial lining, and the mucociliary clearance of the bronchial system. This review gives a synopsis on reactive lung-toxic agents and their specific target molecules in the lung and summarizes the current knowledge about the pathophysiological role of chemosensory signaling in neuronal and non-neuronal cells in toxic lung injury. Finally, we describe possible future strategies for a causal, specifically tailored treatment option based on the mechanistic understanding of molecular events ensuing inhalation of lung-toxic agents.

  15. Nanoparticular surface-bound PCBs, PCDDs, and PCDFs-a novel class of potentially higher toxic POPs.

    Science.gov (United States)

    Schön, Peter; Ctistis, Georgios; Bakker, Wouter; Luthe, Gregor

    2017-05-01

    In a previous study, Env Sci Poll Res:1-7, 2015 showed that polychlorinated biphenyls (PCBs), polychlorinated dibenzo dioxins (PCDDs), and polychlorinated dibenzo furanes (PCDFs) are found in commercially available (nano) particular titanium dioxide as a result of the fabrication. Here, we give a brief perspective and reason the toxicity of these new classes of persistent organic pollutants (POPs) by reviewing also their nanoparticular properties, such as surface-to-volume ratio, photocatalytic activity, polarity shifts, and stealth effect. These insights point towards a new class of POPs and toxicologic effects, which are related to the size but not a result of nanotechnology itself. We pave the way to the understanding of until now unresolved very complex phenomena, such as the indoor exposure, formation, and transformation of POP and sick-building syndrome. This is a fundamental message for nanotoxicology and kinetics and should be taken into account when determining the toxicity of nanomaterials and POPs separately and as a combination.

  16. Human health risk assessment for potentially toxic metals (PTEs) in Acerra' s area (Campanian Region, Italy)

    Science.gov (United States)

    Rezza, Carmela; Sorvari, Jaana; Albanese, Stefano; Matar, Thiombane; Lima, Annamaria; De Vivo, Benedetto

    2017-04-01

    Acerra's territory is situated in the Agro Aversano area. It is characterized by considerable anthropogenic pollution, caused by the illegal dumping and burning of waste since the 1990s. This area has also become highly urbanized and it is undergoing continuous changes in land-use patterns. Altogether 60 % of the total area is dedicated to agriculture, cereals, potato, tobacco and vegetables being the main crops, while 20 % of the area is urban and peri-urban. The remaining part is devoted to industrial use. The waste treatment plant, which incinerates mixed municipal solid waste from most of the municipalities around the city of Naples since 2009, is a potential major source of industrial pollution in the area. The aim of this study was to investigate the level of environmental contamination in Acerra and assess the consequential health risks. 178 topsoil samples and 10 food samples (corn and Chicorium endive) were taken within the whole study area. All samples were analysed for 15 elements (As, Be, Cd, Co, Cr, Cu, Hg, Ni, Pb, Sb, Se, Sn, Tl, V and Zn) at Bureau Veritas Analytical Laboratories (Vancouver, Canada) by ICP-MS and ICP-ES after an aqua-regia digestion. We calculated enrichment factors and pollution indexes of the PTEs in soil and vegetables by comparing their concentrations with the regional background level and trigger and action values for residential/recreational and industrial/commercial land use set in the Italian Environmental Law (152/06). We also calculated the soil-to-plant bio-concentration factor for critical PTEs. In the human health risk assessment, we focused on Be, Cu, Pb, and Zn since they were identified as the most critical elements based on the pollution indexes. We drew up a conceptual model to describe the formation of human health risks in the study area and divided it into agricultural, urban and industrial subareas. Considering the land use and environmental conditions, the following exposure routes are relevant in the formation

  17. Spatial and Temporal Dynamics of Potentially Toxic Cyanobacteria in the Riverine Region of a Temperate Estuarine System Altered by Weirs

    Directory of Open Access Journals (Sweden)

    Jacqueline Martha Malazarte

    2017-10-01

    Full Text Available The effects of weirs on fish and other biological communities have garnered considerable study, whereas the effects of weirs on community composition of toxic cyanobacteria have not yet been well documented. In this study, temporal and spatial variations in species composition and the abundance of potentially toxic cyanobacteria were investigated in the riverine regions of the temperate Youngsan River estuary, where two weirs have recently been constructed. Four stations were sampled 0.5 m below the surface monthly along the channel of the upper river from May 2014 to April 2015 to explore cyanobacterial composition and abundance, while physicochemical and biological parameters were measured to elucidate possible mechanisms controlling these dynamics. Two stations were located upstream at free-flowing sites, and the other stations were located downstream at impounded sites near the weirs. Twenty-eight cyanobacterial species were identified, seven of which were potentially toxic: Microcystis sp., M. aeruginosa, M. flos-aquae, Dolichospermum sp., Aphanocapsa sp., Oscillatoria sp. and Phormidium sp. Microcystis sp. was the most abundant in June 2014 at the lowest station near the weir. Meanwhile, Phormidium sp. occurred at low abundance throughout the study period, except during the winter months, when its abundance was elevated. The interactive forward selection method highlighted dissolved inorganic nitrogen and zooplankton abundance as explanatory variables for this observed variation, but their effects on cyanobacterial growth are unclear. However, temperature was the major determinant for the temporal variation in cyanobacterial populations. Cluster analysis showed that the downstream stations near the weirs had a high similarity of potentially toxic cyanobacteria. Significantly higher abundance, especially of Microcystis sp., was also recorded at the impounded sites suggesting that the presence of weirs might affect variations in toxic

  18. Biofilm formation by Listeria monocytogenes on stainless steel surface and biotransfer potential

    Directory of Open Access Journals (Sweden)

    Maíra Maciel Mattos de Oliveira

    2010-03-01

    Full Text Available An experimental model was proposed to study biofilm formation by Listeria monocytogenes ATCC 19117 on AISI 304 (#4 stainless steel surface and biotransfer potential during this process. In this model, biofilm formation was conducted on the surface of stainless steel coupons, set on a stainless steel base with 4 divisions, each one supporting 21 coupons. Trypic Soy Broth was used as bacterial growth substrate, with incubation at 37 ºC and stirring of 50 rpm. The number of adhered cells was determined after 3, 48, 96, 144, 192 and 240 hours of biofilm formation and biotransfer potential from 96 hours. Stainless steel coupons were submitted to Scanning Electron Microscopy (SEM after 3, 144 and 240 hours. Based on the number of adhered cells and SEM, it was observed that L. monocytogenes adhered rapidly to the stainless steel surface, with mature biofilm being formed after 240 hours. The biotransfer potential of bacterium to substrate occurred at all the stages analyzed. The rapid capacity of adhesion to surface, combined with biotransfer potential throughout the biofilm formation stages, make L. monocytogenes a potential risk to the food industry. Both the experimental model developed and the methodology used were efficient in the study of biofilm formation by L. monocytogenes on stainless steel surface and biotransfer potential.

  19. Role of toxic and bioactive secondary metabolites in colonization and bloom formation by filamentous cyanobacteria Planktothrix.

    Science.gov (United States)

    Kurmayer, Rainer; Deng, Li; Entfellner, Elisabeth

    2016-04-01

    Bloom-forming cyanobacteria Planktothrix agardhii and P. rubescens are regularly involved in the occurrence of cyanotoxin in lakes and reservoirs. Besides microcystins (MCs), which inhibit eukaryotic protein phosphatase 1 and 2A, several families of bioactive peptides are produced, thereby resulting in impressive secondary metabolite structural diversity. This review will focus on the current knowledge of the phylogeny, morphology, and ecophysiological adaptations of Planktothrix as well as the toxins and bioactive peptides produced. The relatively well studied ecophysiological adaptations (buoyancy, shade tolerance, nutrient storage capacity) can partly explain the invasiveness of this group of cyanobacteria that bloom within short periods (weeks to months). The more recent elucidation of the genetic basis of toxin and bioactive peptide synthesis paved the way for investigating its regulation both in the laboratory using cell cultures as well as under field conditions. The high frequency of several toxin and bioactive peptide synthesis genes observed within P. agardhii and P. rubescens, but not for other Planktothrix species (e.g. P. pseudagardhii), suggests a potential functional linkage between bioactive peptide production and the colonization potential and possible dominance in habitats. It is hypothesized that, through toxin and bioactive peptide production, Planktothrix act as a niche constructor at the ecosystem scale, possibly resulting in an even higher ability to monopolize resources, positive feedback loops, and resilience under stable environmental conditions. Thus, refocusing harmful algal bloom management by integrating ecological and phylogenetic factors acting on toxin and bioactive peptide synthesis gene distribution and concentrations could increase the predictability of the risks originating from Planktothrix blooms. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  20. Addressing Geographic Variability in the Comparative Toxicity Potential of Copper and Nickel in Soils

    DEFF Research Database (Denmark)

    Owsianiak, Mikolaj; Rosenbaum, Ralph K.; Huijbregts, Mark A. J.

    2013-01-01

    in the soil was introduced into the definition of CTP. Geographic differences in fate, accessibility, bioavailability, and terrestrial toxicity were assessed by combining the USEtox characterization model, empirical regression models, and terrestrial biotic ligand models. The median CTPs for Cu and Ni with 95...... the fate and bioavailability of Cu in soils. In contrast, the geographic variability of 3 orders of magnitude in the CTP of Ni can mainly be explained by differences in pore water concentration of magnesium (Mg2+). Mg2+ competes with Ni2+ for binding to biotic ligands, influencing the toxicity. Our...

  1. The occurrence of some potentially toxic elements in ex-mining land located in Bidor

    International Nuclear Information System (INIS)

    Ramli Mohd Osman; Ang, L.H.

    2000-01-01

    A 25-hectare study site of an ex-mining land located in Kampung Baharu Tanah Mas, Bidor had been selected for the determination of potentially toxic elements (PTEs). The study site consists of sand, sandy slime, and slime tailings. Some portions of the study A line sampling technique had been site have been cultivated with agriculture crops employed to sample soils at depth of 0-30 cm for sand, sandy slime and slime tailings with or without cultivation. The soil samples from each of these six combinations were made into two composite samples. The composite sample of each combination was then analysed for total concentration of lead (Pb), zinc (Zn), copper (Cu), nickel (Ni), arsenic (As), cadmium (Cd), and mercury (Hg). PTEs were found in the ex-mining land irrespective of types of tailings with or without cultivation. ANOVA was conducted according to Balance Design Analysis. The result showed that the concentration of all of the PTEs except Cu and Cd were not significantly different between soil types-sand, sandy slime and slime tailings. Cu has significantly higher concentration in slime tailings than sandy slime and sand tailings. The concentration of Cd is significantly greater in the sandy slime than sand and slime tailings. There is no significant different in concentration of PTEs between cultivated plots and non-cultivated areas. Hence, cultivation does not increase or decrease the concentration of PTEs in the tin tailings. A probe on the PTEs uptake of two agricultural crops namely sweet potato (Ipomoea batatas) and guava (Psidium guavaja) growing on the ex-mining land irrespective of types of tailings had been conducted. The results showed that only the uptake of Pb was evidently of concern the concentration of Pb in the sweet potatoes and guavas exceeds the permissible limits for both Any Food and Juice Standards of the Food Act And Regulations, 1998. Zn and As in guavas are of concern if one consider the Juice Standard of The Food Act and Regulations

  2. Proteome Profiling Reveals Potential Toxicity and Detoxification Pathways Following Exposure of BEAS-2B Cells to Engineered Nanoparticle Titanium Dioxide

    Science.gov (United States)

    Identification of toxicity pathways linked to chemical -exposure is critical for a better understanding of biological effects of the exposure, toxic mechanisms, and for enhancement of the prediction of chemical toxicity and adverse health outcomes. To identify toxicity pathways a...

  3. O-6-benzylguanine potentiates BCNU but not busulfan toxicity in hematopoietic stem cells

    NARCIS (Netherlands)

    Westerhof, GR; Down, JD; Blokland, [No Value; Wood, M; Boudewijn, A; Watson, AJ; McGown, AT; Ploemacher, RE; Margison, GP

    Objective. Busulfan (BU) is often used in conditioning regimens prior to bone marrow transplantation, but its mechanism of action remains to be resolved. We have examined the possibility that BU may exert part of its toxic effects via DNA alkylation at the Oh position of guanine as this might

  4. Maritime Evaluation of Aerosol Fire Knock Down Tools. Part 2: Toxicity and Corrosion Potential

    Science.gov (United States)

    2014-02-01

    2 ppm can have some physiological impacts particularly in the case of children between the ages of 5 and 12, and asthmatic adults [10]. As such, the...Ventilation Controlled Fires: Toxicity Assesment and Modelling," PhD Thesis, University of Leeds, Leeds, England, 2012. [43] Workers’ Compensation Board

  5. Investigating Potential Toxicity of Leachate from Wood Chip Piles Generated by Roadside Biomass Operations

    Directory of Open Access Journals (Sweden)

    John Rex

    2016-02-01

    Full Text Available Roadside processing of wood biomass leaves chip piles of varying size depending upon whether they were created for temporary storage, spillage, or equipment maintenance. Wood chips left in these piles can generate leachate that contaminates streams when processing sites are connected to waterways. Leachate toxicity and chemistry were assessed for pure aspen (Populus tremuloides Michx., lodgepole pine (Pinus contorta Dougl., hybrid white spruce (Picea engelmannii x glauca Parry, and black spruce (Picea mariana (Mill. Britton as well as from two wood chipping sites using mixes of lodgepole pine and hybrid or black spruce. Leachate was generated using rainfall simulation, a static 28-day laboratory assay, and a field-based exposure. Leachate generated by these exposures was analyzed for organic matter content, phenols, ammonia, pH, and toxicity. Findings indicate that all wood chip types produced a toxic leachate despite differences in their chemistry. The consistent toxicity response highlights the need for runoff management that will disconnect processing sites from aquatic environments.

  6. Competitive potential of trade organization : theoretical and methodological foundations of formation and realization

    OpenAIRE

    Serebryakova, Nadezhda A.; Semenenko, Sergey V.; Grishchenko, Natalya V.; Ulchenko, Tamara Y.

    2016-01-01

    Problematics of competitive potential of organization does not have any multi-disciplinary limitations of research. Study of competitive potential in connection with factors of its formation and conditions for realization, including competition, competitiveness, and competitive advantages of organization, was conducted by many scientists. At that, in view of sectorial specifics, there is domination of works devoted to study of competitive potential of production, not trade, organizations. Ide...

  7. VirtualToxLab — A platform for estimating the toxic potential of drugs, chemicals and natural products

    International Nuclear Information System (INIS)

    Vedani, Angelo; Dobler, Max; Smieško, Martin

    2012-01-01

    The VirtualToxLab is an in silico technology for estimating the toxic potential (endocrine and metabolic disruption, some aspects of carcinogenicity and cardiotoxicity) of drugs, chemicals and natural products. The technology is based on an automated protocol that simulates and quantifies the binding of small molecules towards a series of proteins, known or suspected to trigger adverse effects. The toxic potential, a non-linear function ranging from 0.0 (none) to 1.0 (extreme), is derived from the individual binding affinities of a compound towards currently 16 target proteins: 10 nuclear receptors (androgen, estrogen α, estrogen β, glucocorticoid, liver X, mineralocorticoid, peroxisome proliferator-activated receptor γ, progesterone, thyroid α, and thyroid β), four members of the cytochrome P450 enzyme family (1A2, 2C9, 2D6, and 3A4), a cytosolic transcription factor (aryl hydrocarbon receptor) and a potassium ion channel (hERG). The interface to the technology allows building and uploading molecular structures, viewing and downloading results and, most importantly, rationalizing any prediction at the atomic level by interactively analyzing the binding mode of a compound with its target protein(s) in real-time 3D. The VirtualToxLab has been used to predict the toxic potential for over 2500 compounds: the results are posted on (http://www.virtualtoxlab.org). The free platform — the OpenVirtualToxLab — is accessible (in client–server mode) over the Internet. It is free of charge for universities, governmental agencies, regulatory bodies and non-profit organizations. -- Highlights: ► In silico technology for estimating the toxic potential of drugs and chemicals. ► Simulation of binding towards 16 proteins suspected to trigger adverse effects. ► Mechanistic interpretation and real-time 3D visualization. ► Accessible over the Internet. ► Free of charge for universities, governmental agencies, regulatory bodies and NPOs.

  8. VirtualToxLab — A platform for estimating the toxic potential of drugs, chemicals and natural products

    Energy Technology Data Exchange (ETDEWEB)

    Vedani, Angelo, E-mail: angelo.vedani@unibas.ch [Biographics Laboratory 3R, Klingelbergstrasse 50, 4056 Basel (Switzerland); Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel (Switzerland); Dobler, Max [Biographics Laboratory 3R, Klingelbergstrasse 50, 4056 Basel (Switzerland); Smieško, Martin [Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056 Basel (Switzerland)

    2012-06-01

    The VirtualToxLab is an in silico technology for estimating the toxic potential (endocrine and metabolic disruption, some aspects of carcinogenicity and cardiotoxicity) of drugs, chemicals and natural products. The technology is based on an automated protocol that simulates and quantifies the binding of small molecules towards a series of proteins, known or suspected to trigger adverse effects. The toxic potential, a non-linear function ranging from 0.0 (none) to 1.0 (extreme), is derived from the individual binding affinities of a compound towards currently 16 target proteins: 10 nuclear receptors (androgen, estrogen α, estrogen β, glucocorticoid, liver X, mineralocorticoid, peroxisome proliferator-activated receptor γ, progesterone, thyroid α, and thyroid β), four members of the cytochrome P450 enzyme family (1A2, 2C9, 2D6, and 3A4), a cytosolic transcription factor (aryl hydrocarbon receptor) and a potassium ion channel (hERG). The interface to the technology allows building and uploading molecular structures, viewing and downloading results and, most importantly, rationalizing any prediction at the atomic level by interactively analyzing the binding mode of a compound with its target protein(s) in real-time 3D. The VirtualToxLab has been used to predict the toxic potential for over 2500 compounds: the results are posted on (http://www.virtualtoxlab.org). The free platform — the OpenVirtualToxLab — is accessible (in client–server mode) over the Internet. It is free of charge for universities, governmental agencies, regulatory bodies and non-profit organizations. -- Highlights: ► In silico technology for estimating the toxic potential of drugs and chemicals. ► Simulation of binding towards 16 proteins suspected to trigger adverse effects. ► Mechanistic interpretation and real-time 3D visualization. ► Accessible over the Internet. ► Free of charge for universities, governmental agencies, regulatory bodies and NPOs.

  9. The Potential Liver, Brain, and Embryo Toxicity of Titanium Dioxide Nanoparticles on Mice

    Science.gov (United States)

    Jia, Xiaochuan; Wang, Shuo; Zhou, Lei; Sun, Li

    2017-08-01

    Nanoscale titanium dioxide (nano-TiO2) has been widely used in industry and medicine. However, the safety of nano-TiO2 exposure remains unclear. In this study, we evaluated the liver, brain, and embryo toxicity and the underlying mechanism of nano-TiO2 using mice models. The results showed that titanium was distributed to and accumulated in the heart, brain, spleen, lung, and kidney of mice after intraperitoneal (i.p.) nano-TiO2 exposure, in a dose-dependent manner. The organ/body weight ratios of the heart, spleen, and kidney were significantly increased, and those of the brain and lung were decreased. High doses of nano-TiO2 significantly damaged the functions of liver and kidney and glucose and lipid metabolism, as showed in the blood biochemistry tests. Nano-TiO2 caused damages in mitochondria and apoptosis of hepatocytes, generation of reactive oxygen species, and expression disorders of protective genes in the liver of mice. We found ruptured and cracked nerve cells and inflammatory cell infiltration in the brain. We also found that the activities of constitutive nitric oxide synthases (cNOS), inducible NOS (iNOS), and acetylcholinesterase, and the levels of nitrous oxide and glutamic acid were changed in the brain after nano-TiO2 exposure. Ex vivo mouse embryo models exhibited developmental and genetic toxicity after high doses of nano-TiO2. The size of nano-TiO2 particles may affect toxicity, larger particles producing higher toxicity. In summary, nano-TiO2 exhibited toxicity in multiple organs in mice after exposure through i.p. injection and gavage. Our study may provide data for the assessment of the risk of nano-TiO2 exposure on human health.

  10. Formation of chain structures in systems of charged grains interacting via isotropic pair potentials

    Energy Technology Data Exchange (ETDEWEB)

    Vaulina, O. S.; Lisina, I. I.; Koss, K. G., E-mail: Xeniya.Koss@gmail.com [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2013-05-15

    Conditions for the formation of chain structures of charged grains confined in the gravitational field by external electric fields are studied analytically and numerically. The relationships between the parameters of the pair interaction potential, the number of grains, and the electric field gradient in the trap are found. A criterion for the violation of stable equilibrium in a quasi-one-dimensional chain of grains and the formation of a new configuration in the system is proposed.

  11. Hydrocarbon Source Rock Potential of the Sinamar Formation, Muara Bungo, Jambi

    Directory of Open Access Journals (Sweden)

    Moh. Heri Hermiyanto Zajuli

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v1i1.175The Oligocene Sinamar Formation consists of shale, claystone, mudstone, sandstone, conglomeratic sandstone, and intercalation of coal seams. The objective of study was to identify the hydrocarbon source rock potential of the Sinamar Formation based on geochemichal characteristics. The analyses were focused on fine sediments of the Sinamar Formation comprising shale, claystone, and mudstone. Primary data collected from the Sinamar Formation well and outcrops were analyzed according to TOC, pyrolisis analysis, and gas chromatography - mass spectometry of normal alkanes that include isoprenoids and sterane. The TOC value indicates a very well category. Based on TOC versus Pyrolysis Yields (PY diagram, the shales of Sinamar Formation are included into oil prone source rock potential with good to excellent categories. Fine sediments of the Sinamar Formation tend to produce oil and gas originated from kerogen types I and III. The shales tend to generate oil than claystone and mudstone and therefore they are included into a potential source rock. 

  12. Toxicity potentials from waste cellular phones, and a waste management policy integrating consumer, corporate, and government responsibilities.

    Science.gov (United States)

    Lim, Seong-Rin; Schoenung, Julie M

    2010-01-01

    Cellular phones have high environmental impact potentials because of their heavy metal content and current consumer attitudes toward purchasing new phones with higher functionality and neglecting to return waste phones into proper take-back systems. This study evaluates human health and ecological toxicity potentials from waste cellular phones; highlights consumer, corporate, and government responsibilities for effective waste management; and identifies key elements needed for an effective waste management strategy. The toxicity potentials are evaluated by using heavy metal content, respective characterization factors, and a pathway and impact model for heavy metals that considers end-of-life disposal in landfills or by incineration. Cancer potentials derive primarily from Pb and As; non-cancer potentials primarily from Cu and Pb; and ecotoxicity potentials primarily from Cu and Hg. These results are not completely in agreement with previous work in which leachability thresholds were the metric used to establish priority, thereby indicating the need for multiple or revised metrics. The triple bottom line of consumer, corporate, and government responsibilities is emphasized in terms of consumer attitudes, design for environment (DfE), and establishment and implementation of waste management systems including recycling streams, respectively. The key strategic elements for effective waste management include environmental taxation and a deposit-refund system to motivate consumer responsibility, which is linked and integrated with corporate and government responsibilities. The results of this study can contribute to DfE and waste management policy for cellular phones. 2010 Elsevier Ltd. All rights reserved.

  13. Ginkgolide A contributes to the potentiation of acetaminophen toxicity by Ginkgo biloba extract in primary cultures of rat hepatocytes

    International Nuclear Information System (INIS)

    Rajaraman, Ganesh; Chen, Jie; Chang, Thomas K.H.

    2006-01-01

    The present cell culture study investigated the effect of Ginkgo biloba extract pretreatment on acetaminophen toxicity and assessed the role of ginkgolide A and cytochrome P450 3A (CYP3A) in hepatocytes isolated from adult male Long-Evans rats provided ad libitum with a standard diet. Acetaminophen (7.5-25 mM for 24 h) conferred hepatocyte toxicity, as determined by the lactate dehydrogenase (LDH) assay. G. biloba extract alone increased LDH leakage in hepatocytes at concentrations ≥ 75 μg/ml and ≥ 750 μg/ml after a 72 h and 24 h treatment period, respectively. G. biloba extract (25 or 50 μg/ml once every 24 h for 72 h) potentiated LDH leakage by acetaminophen (10 mM for 24 h; added at 48 h after initiation of extract pretreatment). The effect was confirmed by a decrease in [ 14 C]-leucine incorporation. At the level present in a modulating concentration (50 μg/ml) of the extract, ginkgolide A (0.55 μg/ml), which increased CYP3A23 mRNA levels and CYP3A-mediated enzyme activity, accounted for part but not all of the potentiating effect of the extract on acetaminophen toxicity. This occurred as a result of CYP3A induction by ginkgolide A because triacetyloleandomycin (TAO), a specific inhibitor of CYP3A catalytic activity, completely blocked the effect of ginkgolide A. Ginkgolide B, ginkgolide C, ginkgolide J, quercetin, kaempferol, isorhamnetin, and isorhamnetin-3-O-rutinoside did not alter the extent of LDH leakage by acetaminophen. In summary, G. biloba pretreatment potentiated acetaminophen toxicity in cultured rat hepatocytes and ginkgolide A contributed to this novel effect of the extract by inducing CYP3A

  14. Use of adverse outcome pathways in chemical toxicity testing: potential advantages and limitations

    Directory of Open Access Journals (Sweden)

    Jaeseong Jeong

    2017-12-01

    Full Text Available Amid revolutionary changes in toxicity assessment brought about by increasing regulation of chemicals, adverse outcome pathways (AOPs have emerged as a useful framework to assess adverse effect of chemicals using molecular level effect, which aid in setting environmental regulation policies. AOPs are biological maps that describe mechanisms linking molecular initiating event to adverse outcomes (AOs at an individual level. Each AOP consists of a molecular initiating event, key events, and an AO. AOPs use molecular markers to predict endpoints currently used in risk assessment, promote alternatives to animal model-based test methods, and provide scientific explanations for the effects of chemical exposures. Moreover, AOPs enhance certainty in interpreting existing and new information. The application of AOPs in chemical toxicity testing will help shift the existing paradigm of chemical management based on apical endpoints toward active application of in silico and in vitro data.

  15. Air toxics provisions of the Clean Air Act: Potential impacts on energy

    International Nuclear Information System (INIS)

    Hootman, H.A.; Vernet, J.E.

    1991-11-01

    This report provides an overview of the provisions of the Clean Air Act and its Amendments of 1990 that identify hazardous air pollutant (HAP) emissions and addresses their regulation by the US Environmental Protection Agency (EPA). It defines the major energy sector sources of these HAPs that would be affected by the regulations. Attention is focused on regulations that would cover coke oven emissions; chromium emission from industrial cooling towers and the electroplating process; HAP emissions from tank vessels, asbestos-related activities, organic solvent use, and ethylene oxide sterilization; and emissions of air toxics from municipal waste combustors. The possible implications of Title III regulations for the coal, natural gas, petroleum, uranium, and electric utility industries are examined. The report discusses five major databases of HAP emissions: (1) TRI (EPA's Toxic Release Inventory); (2) PISCES (Power Plant Integrated Systems: Chemical Emissions Studies developed by the Electric Power Research Institute); (3) 1985 Emissions Inventory on volatile organic compounds (used for the National Acid Precipitation Assessment Program); (4) Particulate Matter Species Manual (EPA); and (5) Toxics Emission Inventory (National Aeronautics and Space Administration). It also offers information on emission control technologies for municipal waste combustors

  16. Air toxics provisions of the Clean Air Act: Potential impacts on energy

    Energy Technology Data Exchange (ETDEWEB)

    Hootman, H.A.; Vernet, J.E.

    1991-11-01

    This report provides an overview of the provisions of the Clean Air Act and its Amendments of 1990 that identify hazardous air pollutant (HAP) emissions and addresses their regulation by the US Environmental Protection Agency (EPA). It defines the major energy sector sources of these HAPs that would be affected by the regulations. Attention is focused on regulations that would cover coke oven emissions; chromium emission from industrial cooling towers and the electroplating process; HAP emissions from tank vessels, asbestos-related activities, organic solvent use, and ethylene oxide sterilization; and emissions of air toxics from municipal waste combustors. The possible implications of Title III regulations for the coal, natural gas, petroleum, uranium, and electric utility industries are examined. The report discusses five major databases of HAP emissions: (1) TRI (EPA's Toxic Release Inventory); (2) PISCES (Power Plant Integrated Systems: Chemical Emissions Studies developed by the Electric Power Research Institute); (3) 1985 Emissions Inventory on volatile organic compounds (used for the National Acid Precipitation Assessment Program); (4) Particulate Matter Species Manual (EPA); and (5) Toxics Emission Inventory (National Aeronautics and Space Administration). It also offers information on emission control technologies for municipal waste combustors.

  17. Air toxics provisions of the Clean Air Act: Potential impacts on energy

    Energy Technology Data Exchange (ETDEWEB)

    Hootman, H.A.; Vernet, J.E.

    1991-11-01

    This report provides an overview of the provisions of the Clean Air Act and its Amendments of 1990 that identify hazardous air pollutant (HAP) emissions and addresses their regulation by the US Environmental Protection Agency (EPA). It defines the major energy sector sources of these HAPs that would be affected by the regulations. Attention is focused on regulations that would cover coke oven emissions; chromium emission from industrial cooling towers and the electroplating process; HAP emissions from tank vessels, asbestos-related activities, organic solvent use, and ethylene oxide sterilization; and emissions of air toxics from municipal waste combustors. The possible implications of Title III regulations for the coal, natural gas, petroleum, uranium, and electric utility industries are examined. The report discusses five major databases of HAP emissions: (1) TRI (EPA`s Toxic Release Inventory); (2) PISCES (Power Plant Integrated Systems: Chemical Emissions Studies developed by the Electric Power Research Institute); (3) 1985 Emissions Inventory on volatile organic compounds (used for the National Acid Precipitation Assessment Program); (4) Particulate Matter Species Manual (EPA); and (5) Toxics Emission Inventory (National Aeronautics and Space Administration). It also offers information on emission control technologies for municipal waste combustors.

  18. Spray Toxicity and Risk Potential of 42 Commonly Used Formulations of Row Crop Pesticides to Adult Honey Bees (Hymenoptera: Apidae).

    Science.gov (United States)

    Zhu, Yu Cheng; Adamczyk, John; Rinderer, Thomas; Yao, Jianxiu; Danka, Robert; Luttrell, Randall; Gore, Jeff

    2015-12-01

    To combat an increasing abundance of sucking insect pests, >40 pesticides are currently recommended and frequently used as foliar sprays on row crops, especially cotton. Foraging honey bees may be killed when they are directly exposed to foliar sprays, or they may take contaminated pollen back to hives that maybe toxic to other adult bees and larvae. To assess acute toxicity against the honey bee, we used a modified spray tower to simulate field spray conditions to include direct whole-body exposure, inhalation, and continuing tarsal contact and oral licking after a field spray. A total of 42 formulated pesticides, including one herbicide and one fungicide, were assayed for acute spray toxicity to 4-6-d-old workers. Results showed significantly variable toxicities among pesticides, with LC50s ranging from 25 to thousands of mg/liter. Further risk assessment using the field application concentration to LC1 or LC99 ratios revealed the risk potential of the 42 pesticides. Three pesticides killed less than 1% of the worker bees, including the herbicide, a miticide, and a neonicotinoid. Twenty-six insecticides killed more than 99% of the bees, including commonly used organophosphates and neonicotinoids. The remainder of the 13 chemicals killed from 1-99% of the bees at field application rates. This study reveals a realistic acute toxicity of 42 commonly used foliar pesticides. The information is valuable for guiding insecticide selection to minimize direct killing of foraging honey bees, while maintaining effective control of field crop pests. Published by Oxford University Press [on behalf of Entomological Society of America] 2015. This work is written by US Government employees and is in the public domain in the US.

  19. Investigation of the toxic potential of crude ethanol extract of Annona coriacea (araticum seeds in acute exposed mice

    Directory of Open Access Journals (Sweden)

    Guilherme Nobre L. do Nascimento

    2012-01-01

    Full Text Available In this study, Annona coriacea Mart., Annonaceae, was examined for possible toxic effects on brain, liver and kidney of mice exposed to crude extract of the seeds (CESAN of this plant. CESAN was administered by gavage for four days at doses of 12.5, 25, 50, and 100 mg/kg/day. Significant changes on liver were observed, which showed reduction in the number of hepatocytes per area and increase the apoptotic index in the exposed groups, and changes in the cytoplasm and nucleus of these cells and reduced consumption of water and feed in these animals. For the other studied areas, brain and kidneys showed no changes in the parameters used in this study. The results suggest hepatotoxic effects of CESAN, but without damage to brain and kidneys in this experiment, showing a toxic potential to this species, as to the Annonaceae family.

  20. Objective Assessment of an Ionic Footbath (IonCleanse: Testing Its Ability to Remove Potentially Toxic Elements from the Body

    Directory of Open Access Journals (Sweden)

    Deborah A. Kennedy

    2012-01-01

    Full Text Available Ionic footbaths are often used in holistic health centres and spas to aid in detoxification; however, claims that these machines eliminate toxins from the body have not been rigorously evaluated. In this proof-of-principle study, we sought to measure the release of potentially toxic elements from ionic footbaths into distilled and tap water with and without feet. Water samples were collected and analyzed following 30-minute ionic footbath sessions without feet using both distilled (n=1 and tap water (n=6 and following four ionic footbaths using tap water (once/week for 4 weeks in six healthy participants. Urine collection samples were analyzed at four points during the study. Hair samples were analyzed for element concentrations at baseline and study conclusion. Contrary to claims made for the machine, there does not appear to be any specific induction of toxic element release through the feet when running the machine according to specifications.

  1. Objective Assessment of an Ionic Foot bath (Ion Cleanse): Testing Its Ability to Remove Potentially Toxic Elements from the Body

    International Nuclear Information System (INIS)

    Kennedy, D.A.; Cooley, K.; Seely, D.; Kennedy, D.A.; Cooley, K.; Einarson, Th.R.; Seely, D.

    2012-01-01

    Ionic foot baths are often used in holistic health centres and spas to aid in detoxification; however, claims that these machines eliminate toxins from the body have not been rigorously evaluated. In this proof-of-principle study, we sought to measure the release of potentially toxic elements from ionic foot baths into distilled and tap water with and without feet. Water samples were collected and analyzed following 30-minute ionic foot bath sessions without feet using both distilled (n=1) and tap water (n=6) and following four ionic foot baths using tap water (once/week for 4 weeks) in six healthy participants. Urine collection samples were analyzed at four points during the study. Hair samples were analyzed for element concentrations at baseline and study conclusion. Contrary to claims made for the machine, there does not appear to be any specific induction of toxic element release through the feet when running the machine according to specifications

  2. Effect of Pre-Gamma Irradiation Induction of Metallothionein on potentially Radiation-Induced Toxic Heavy Metals Ions In Rats

    International Nuclear Information System (INIS)

    El-Shamy, El.

    2004-01-01

    Metallothionein, which is a cystein-rich metal binding protein, can act as free radical scavenger and involved in resistance to heavy metal toxicity. The induction of synthesis has been shown to protect organs from the toxic effect of radiation. This study aimed to stud the effects of pre-irradiation induction of by heavy metal (Zinc sulfate) on potentially gamma radiation-induced toxic heavy metals ions in rate liver and kidney tissues. Forty eight albino rats were included in this study. They were divided into eight groups each of six animals. Two control groups injected with saline. Two Zinc sulfate-treated groups injected with zinc sulfate, two Irradiated groups exposed to a single dose level (7 Gy) of whole body gamma irradiation and two combined zinc sulfate and irradiation groups injected with zinc sulfate and exposed to whole body gamma irradiation (at dose 7 Gy). Animals of all groups were sacrificed 24 and 48 hours after last either zinc sulfate dose or irradiation. Samples of liver and kidney's tissues were subjected to the following investigations: Estimation of tissue heavy Metals (Zinc, Iron and Copper), and tissue (MT). After irradiation, liver and kidney MT were increased approximately 10-fold and 2-fold respectively after irradiation. Accumulation of zinc and iron in both liver and kidney tissues were detected, while accumulation of copper only in the liver tissues. The pre-irradiation treatment with zinc sulfate (Zn SO4) resulted in highly significant decrease in zinc, iron, and copper levels in both liver and kidney tissues in comparison with irradiation groups. Conclusion, it can be supposed that pre-irradiation injection of ZnSO 4 exerted protective effect against the potentially radiation-induced toxic heavy metals ions through MT induction

  3. [Influence of catalytic ozonation process on suppressing bromate formation potential in drinking water treatment].

    Science.gov (United States)

    Han, Bang-Jun; Ma, Jun; Zhang, Tao; Han, Hong-Da; Shen, Li-Ping; Zhang, Li-Zhu

    2008-03-01

    An investigation is given to the bromate formation of catalytic ozonation in treating drinking water. It is shown that the c x t value of ozone depletion stage plays a more important role in BrO3(-) formation. Catalyst addition not only reduces the residual ozone content by 60.0% - 77.4% but also extends the ozone ID stage time from 4.3 min to 6.8 min, which makes the ozone c x t value shorter. A full-scale study indicates a very effective strength and performance of catalytic ozonation in controlling BrO3(-) formation and it is able to suppress BrO3(-) formation potential by 51.7% on average.

  4. Missing ozone-induced potential aerosol formation in a suburban deciduous forest

    Science.gov (United States)

    Nakayama, T.; Kuruma, Y.; Matsumi, Y.; Morino, Y.; Sato, K.; Tsurumaru, H.; Ramasamy, S.; Sakamoto, Y.; Kato, S.; Miyazaki, Y.; Mochizuki, T.; Kawamura, K.; Sadanaga, Y.; Nakashima, Y.; Matsuda, K.; Kajii, Y.

    2017-12-01

    As a new approach to investigating formation processes of secondary organic aerosol (SOA) in the atmosphere, ozone-induced potential aerosol formation was measured in summer at a suburban forest site surrounded by deciduous trees, near Tokyo, Japan. After passage through a reactor containing high concentrations of ozone, increases in total particle volume (average of 1.4 × 109 nm3/cm3, which corresponds to 17% that of pre-existing particles) were observed, especially during daytime. The observed aerosol formations were compared with the results of box model simulations using simultaneously measured concentrations of gaseous and particulate species. According to the model, the relative contributions of isoprene, monoterpene, and aromatic hydrocarbon oxidation to SOA formation in the reactor were 24, 21, and 55%, respectively. However, the model could explain, on average, only ∼40% of the observed particle formation, and large discrepancies between the observations and model were found, especially around noon and in the afternoon when the concentrations of isoprene and oxygenated volatile organic compounds were high. The results suggest a significant contribution of missing (unaccounted-for) SOA formation processes from identified and/or unidentified volatile organic compounds, especially those emitted during daytime. Further efforts should be made to explore and parameterize this missing SOA formation to assist in the improvement of atmospheric chemistry and climate models.

  5. Gender differences in methionine accumulation and metabolism in freshly isolated mouse hepatocytes: Potential roles in toxicity

    International Nuclear Information System (INIS)

    Dever, Joseph T.; Elfarra, Adnan A.

    2009-01-01

    L-Methionine (Met) is hepatotoxic at high concentrations. Because Met toxicity in freshly isolated mouse hepatocytes is gender-dependent, the goal of this study was to assess the roles of Met accumulation and metabolism in the increased sensitivity of male hepatocytes to Met toxicity compared with female hepatocytes. Male hepatocytes incubated with Met (30 mM) at 37 o C exhibited higher levels of intracellular Met at 0.5, 1.0, and 1.5 h, respectively, compared to female hepatocytes. Conversely, female hepatocytes had higher levels of S-adenosyl-L-methionine compared to male hepatocytes. Female hepatocytes also exhibited higher L-methionine-L-sulfoxide levels relative to control hepatocytes, whereas the increases in L-methionine-D-sulfoxide (Met-D-O) levels were similar in hepatocytes of both genders. Addition of aminooxyacetic acid (AOAA), an inhibitor of Met transamination, significantly increased Met levels at 1.5 h and increased Met-D-O levels at 1.0 and 1.5 h only in Met-exposed male hepatocytes. No gender differences in cytosolic Met transamination activity by glutamine transaminase K were detected. However, female mouse liver cytosol exhibited higher methionine-DL-sulfoxide (MetO) reductase activity than male mouse liver cytosol at low (0.25 and 0.5 mM) MetO concentrations. Collectively, these results suggest that increased cellular Met accumulation, decreased Met transmethylation, and increased Met and MetO transamination in male mouse hepatocytes may be contributing to the higher sensitivity of the male mouse hepatocytes to Met toxicity in comparison with female mouse hepatocytes.

  6. Analysis of Factors of Influence of the Market Environment upon Formation of the Enterprise Labour Potential

    Directory of Open Access Journals (Sweden)

    Zborovska Olha M.

    2014-03-01

    Full Text Available The article analyses external and internal factors of the market environment, which influence formation of the enterprise labour potential. It offers supplement the existing classification properties with the following ones: international, political-legal and natural-climate factors. It shows that, in the result of the balanced reaction on the international level of influence of factors of formation of labour potential, it is possible to sharply accelerate development of the labour potential by means of realisation of programmes of international education, legal regulation of migration, active participation in various inter-state projects, etc. Influence of political-legal factors of formation of the labour potential shows up in inter-state agreements on labour migration regulation, in application of the system of uniform branch tariff-qualification reference books and in establishment of the system of licensing individual types of activity. Natural-climate conditions exert significant influence upon the level of labour potential. This influence shows up: in different life expectancies, sickness rate, labour life duration, etc. for various natural-climate zones. The article classifies the factors of labour potential with respect to the enterprise also both by exogenous and endogenous groups.

  7. The Effect of Complex Formation upon the Redox Potentials of Metallic Ions. Cyclic Voltammetry Experiments.

    Science.gov (United States)

    Ibanez, Jorge G.; And Others

    1988-01-01

    Describes experiments in which students prepare in situ soluble complexes of metal ions with different ligands and observe and estimate the change in formal potential that the ion undergoes upon complexation. Discusses student formation and analysis of soluble complexes of two different metal ions with the same ligand. (CW)

  8. Deoxyribonuclease Is a Potential Counter Regulator of Aberrant Neutrophil Extracellular Traps Formation after Major Trauma

    Directory of Open Access Journals (Sweden)

    Wei Meng

    2012-01-01

    Conclusions. DNase degrades NETs in a concentration-dependent manner and therefore could have a potential regulatory effect on NET formation in neutrophils. This may inhibit the antibacterial effects of NETs or protect the tissue from autodestruction in inadequate NETs release in septic patients.

  9. Rural School as a Resource for the Intellectual and Labour Potential Formation of the Rural Society

    Science.gov (United States)

    Nasibullov, Ramis R.; Korshunova, Olga V.; Arshabekov, Nurgali R.

    2016-01-01

    The relevance of the research problem is reasoned by the need to create conceptual grounds of life organization variants in the rural school as a resource of intellectual and labor potential formation of rural society taking into account the socio-economic realities of Russia's development in the beginning of the twenty-first century, as well as…

  10. Deepening of floating potential for tungsten target plate on the way to nanostructure formation

    International Nuclear Information System (INIS)

    Takamura, Shuichi; Miyamoto, Takanori; Ohno, Noriyasu

    2010-01-01

    Deepening of floating potential has been observed on the tungsten target plate immersed in high-density helium plasma with hot electron component on the way to nanostructure formation. The physical mechanism is thought to be a reduction of secondary electron emission from such a complex nano fiber-form structure on the tungsten surface. (author)

  11. Double Layers: Potential Formation and Related Nonlinear Phenomena in Plasmas: Proceedings of the 5th Symposium

    Science.gov (United States)

    Iizuka, S.

    1998-02-01

    The Table of Contents for the book is as follows: * PREFACE * INTERNATIONAL SCIENTIFIC COMMITTEE * LOCAL ORGANIZING COMMITTEE AT TOHOKU UNIVERSITY * CHAPTER 1: DOUBLE LAYERS, SHEATHS, AND POTENTIAL STRUCTURES * 1.1 Double Layers * On Fluid Models of Stationary, Acoustic Double Layers (Invited) * Particle Simulation of Double Layer (Invited) * Space-Time Dependence of Non-Steady Double Layers * The Role of Low Energy Electrons for the Generation of Anode Double Layers in Glow Discharges * Arbitrary Amplitude Ion-Acoustic Double Layers in a Dusty Plasma * 1.2 Sheaths * Bounded Plasma Edge Physics as Observed from Simulations in 1D and 2D (Invited) * Control of RF Sheath Structure in RF Diode Discharge * Observation of Density Gradients with Fine Structures and Low Frequency Wave Excitation at the Plasma-Sheath Boundary * Double Sheath Associated with an Electron Emission to a Plasma Containing Negative Ions * Sheath Edge and Floating Potential for Multi-Species Plasmas Including Dust Particles * 1.3 Potential Structures and Oscillations * Potential Structure Formed at a Constriction of a DC He Positive Column and its Coupling with Ionization Wave * Potential Structure in a New RF Magnetron Device with a Hollow Electrode * Potential Disruption in a RF Afterglow Electronegative Plasma * Potential Oscillation in a Strongly Asymmetry RF Discharge Containing Negative Ions * Effects of External Potential Control on Coulomb Dust Behavior * Potential Structure of Carbon Arc Discharge for High-Yield Fullerenes Formation * Control of Axial and Radial Potential Profiles in Tandem Mirrors (Invited) * CHAPTER 2: FIELD-ALIGNED ELECTRIC FIELDS AND RELATED PARTICLE ACCELERATIONS * 2.1 Field-Aligned Potential Formation * Formation of Large Potential Difference in a Plasma Flow along Converging Magnetic Field Lines (Invited) * Presheath Formation in front of an Oblique End-Plate in a Magnetized Sheet Plasma * Plasma Potential Formation Due to ECRH in a Magnetic Well * Electrostatic

  12. Evaluation of the patterns of potentially toxic exposures in Mississippi following Hurricane Katrina.

    Science.gov (United States)

    Cox, Robert; Amundson, Teresa; Brackin, Bruce

    2008-09-01

    To describe the changes in the frequency of selected toxic exposures reported to the state poison control center following Hurricane Katrina. The numbers of selected exposures reported to the Mississippi Poison Control Center at 0-2 weeks, 3-4 weeks, and 5-12 weeks following Hurricane Katrina were compared to those for the same time periods in the previous 3 years. Absolute numbers of exposures and odds ratios with confidence intervals were used for comparison. In the first 2 weeks following Hurricane Katrina, there were 44 reported gasoline exposures compared to 7 expected, 8 lamp oil exposures compared to 1 expected, and seven carbon monoxide exposures compared to 1 expected. Only gasoline exposures remained elevated in the second 2 weeks period following the hurricane. Lamp oil exposures were elevated during the 5-12 week recovery period. There was no increase in the frequency of exposures to household cleaning agents, food poisoning, pediatric exposures, drug-related suicide events, bites and stings, or venomous snakebites. The most common toxic exposures following Hurricane Katrina were related to the lack of typical energy sources, electricity, and gasoline.

  13. The potential role of combined anti-oxidants against cadmium toxicity on liver of rats.

    Science.gov (United States)

    Koyuturk, Meral; Yanardag, Refiye; Bolkent, Sehnaz; Tunali, Sevim

    2007-08-01

    Cadmium (Cd), a widely distributed toxic trace metal, has been shown to accumulate in liver after long- and short-term exposure. Cd (2 mg/kg/day CdCl2) was intraperitoneally given to rats for eight days. Vitamin C (250 mg/kg/day) + vitamin E (250 mg/kg/day) + sodium selenate (0.25 mg/kg/day) were given to rats by oral means. The animals were treated by anti-oxidants one hour prior to treatment with Cd every day. The degenerative changes were observed in the groups given only Cd and anti-oxidants + Cd. Metallothionein (MT) immunoreactivity increased in cytoplasm of hepatocytes of the rats given Cd when compared with controls. In a number of cells with Cd and anti-oxidants treatment, immunoreactivity increase was more than in the group given Cd only and nuclear MT expression was also detected. Cell proliferation was assessed with proliferating cell nuclear antigen (PCNA) immunohistochemistry. PCNA expressions increased in all groups more than in the controls. Anti-oxidants treatment increased cell proliferation. In the animals administered with Cd, an increase in serum aspartate (AST) and alanine (ALT) aminotransferases, liver glutathione (GSH) and lipid peroxidation (LPO) levels were observed. On the other hand, in the rats treated with anti-oxidants and Cd, serum AST and ALT, liver glutathione and LPO levels decreased. As a result, these results suggest that combined anti-oxidants treatment might be useful in protection of liver against Cd toxicity.

  14. Potential Renoprotective Effects of Rosemary and Thyme Against Gentamicin Toxicity in Rats.

    Science.gov (United States)

    Abdel-Azeem, Amal S; Hegazy, Amany M; Zeidan, Hala M; Ibrahim, Khadiga S; El-Sayed, Eman M

    2017-07-04

    Gentamicin (GM) is a drug used commonly against gram-negative bacteria. Its therapeutic use is mainly limited by its nephrotoxicity. This investigation was aimed at evaluating the nephroprotective effects of rosemary (RM; Rosmarinus officinalis) and thyme (TV; Thymus vulgaris) against GM toxicity. Rats were divided into four groups. Normal control group was treated intraperitoneally (i.p.) with saline; positive control group was administered GM 60 mg/kg/day i.p.; RM group was co-administered 8% RM aqueous extract, 10 mL/kg/day, orally with GM; and TV group was co-administered 8% TV aqueous extract orally, 10 mL/kg/day with GM. Both RM and TV groups extracted significantly ameliorated plasma kidney function biomarkers, and reduced malondialdhyde and glucose levels. Meanwhile, RM extract significantly modulated the electrolyte concentration and increased plasma insulin levels as compared with the GM group. However, the aqueous extract of RM showed more pronounced effects than TV extract. Our data were confirmed by histopathological examination and deoxyribonucleic acid (DNA) fragmentation analysis. Deleterious histopathological changes and increased DNA fragmentation induced by GM treatment were markedly controlled by the co-administration of RM and TV. Such renoprotective influence of RM and TV suggests their concurrent supplementation with GM therapy to limit GM toxicity.

  15. Proteome Profiling of BEAS-2B Cells Treated with Titanium Dioxide Reveals Potential Toxicity of and Detoxification Pathways for Nanomaterial

    Science.gov (United States)

    Oxidative stress is known to play important roles in nanomaterial-induced toxicities. However, the proteins and signaling pathways associated with nanomaterial-mediated oxidative stress and toxicity are largely unknown. To identify oxidative stress-responding toxicity pathways an...

  16. Proteome Profiling Reveals Potential Toxicity and Detoxification Pathways Following Exposure of BEAS-2B Cells to Engineered Titanium Dioxide Nanoparticles

    Science.gov (United States)

    Oxidative stress is known to play important roles in engineered nanomaterial induced cellular toxicity. However, the proteins and signaling pathways associated with the engineered nanomaterial mediated oxidative stress and toxicity are largely unknown. To identify these toxicity ...

  17. Generation potential of kerogen of the Bazhenov formation and possibility of its implementation

    Directory of Open Access Journals (Sweden)

    A.G. Kalmykov

    2017-05-01

    Full Text Available Bazhenov formation is one of the most well-known and potentially productive Russian oil shale formations. However, conventional methods often do not provide oil flow rate from the formation. Therefore, in recent years, studies are devoted to development of new methods for oil production and the alternate potentials of the Bazhenov formation exploration. The article describes generation potential of kerogen, that shows the amount of hydrocarbon compounds which could form in the reservoir after a long period of time as a result of katagenesis, and the results of the thermal effect on the rock samples in the laboratory for synthetic oil production by implementing generation potential. It was shown that synthetic oil is produced by the heat of Bazhenov formation samples in a closed system during 7 days in presence of water in the temperature range from 250°C to 350°C, oil amount may reach 25 mg HC/g of rock (~3 wt.% of the sample. The maximum oil yield was at 300°C, but the composition of petroleum products varies with temperature changes. It was found that depending on the stage of katagenetic transformation duration of heating for maximum yield of hydrocarbon compounds recovery varies from a few days for inmature kerogen to two weeks for highly maturated one. It was demonstrated that secondary cracking of products, which can occur at advanced temperatures and prolonged exposure should been taken into account when optimal heating conditions are selected. Hydrocarbon systems composition analysis showed that synthetic oil is comparable with natural oil and different from the chloroform extract, and heating conditions alteration allows to control the composition of produced oil that may be promising for use in the petroleum and chemical industries. Thus, the method of synthetic crude oil production by implementation of the generation capacity of kerogen by thermal stimulation in the presence of water with 80% of generation potential released was

  18. Occurrence and potential toxicity of pyrethroids and other insecticides in bed sediments of urban streams in central Texas

    Energy Technology Data Exchange (ETDEWEB)

    Hintzen, Emily P. [Department of Environmental Studies, Baylor University, Waco, TX 76798 (United States); Lydy, Michael J. [Fisheries and Illinois Aquaculture Center, and Department of Zoology, Southern Illinois University, Carbondale, IL 62091 (United States); Belden, Jason B. [Department of Zoology, Oklahoma State University, 430 Life Science West, Stillwater, OK 74078 (United States)], E-mail: jbelden@okstate.edu

    2009-01-15

    Despite heavy insecticide usage in urban areas, only a few studies have investigated the impact of current-use insecticides on benthic invertebrates in urban streams. The objective of this study was to measure the presence and concentration of current-use pesticides in sediments of residential streams in central Texas. Additionally, toxicity of these sediments to Hyalella azteca was evaluated. Sediment samples were collected from several sites in urban streams over the course of a year, of which, 66% had greater than one toxic unit (TU) of insecticide. Bifenthrin was the greatest contributor accounting for 65% of the TUs, and sediment toxicity to H. azteca correlated with the magnitude of total insecticides and bifenthrin TUs. The results of this study further raise concerns over the environmental consequences posed by many current-use insecticides, especially pyrethroids, in urban settings. - This study examined the presence of insecticides in Texas stream sediments as a model for evaluating the potential impact of urban insecticide use in the Southern United States.

  19. The water-soluble fraction of potentially toxic elements in contaminated soils: relationships between ecotoxicity, solubility and geochemical reactivity.

    Science.gov (United States)

    Rocha, L; Rodrigues, S M; Lopes, I; Soares, A M V M; Duarte, A C; Pereira, E

    2011-09-01

    To better understand the impacts posed by soil contamination to aquatic ecosystems it is crucial to characterise the links between ecotoxicity, chemical availability and geochemical reactivity of potentially toxic elements (PTE's) in soils. We evaluated the adverse effects of water extracts obtained from soils contaminated by chemical industry and mining, using a test battery including organisms from different trophic levels (bacteria, algae and daphnids). These tests provided a quick assessment of the ecotoxicity of soils with respect to possible adverse effects on aquatic organisms although the ecotoxicological responses could be related to the solubility of PTE's only to a limited extent. The analysis of results of bioassays together with the chemical characterisation of water extracts provided additional relevant insight into the role of conductivity, pH, Al, Fe, and Mn of soil extracts on toxicity to organisms. Furthermore, an important conclusion of this study was that the toxicity of extracts to the aquatic organisms could also be related to the soil properties (pH, Org C and Fe(ox)) and to the reactivity of PTE's in soils which in fact control the soluble fraction of the contaminants. The combined assessment of ecotoxicity in water fractions, solubility and geochemical reactivity of PTE's in soils provided a more comprehensive understanding of the bioavailability of inorganic contaminants than ecotoxicological or chemical studies alone and can therefore be most useful for environmental risks assessment of contaminated soils. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Estimating genetic potential of biofuel forest hardwoods to withstand metal toxicity in industrial effluent under dry tropical conditions.

    Science.gov (United States)

    Manzoor, S A; Mirza, S N; Zubair, M; Nouman, W; Hussain, S B; Mehmood, S; Irshad, A; Sarwar, N; Ammar, A; Iqbal, M F; Asim, A; Chattha, M U; Chattha, M B; Zafar, A; Abid, R

    2015-08-14

    Biofuel tree species are recognized as a promising alternative source of fuel to conventional forms. Additionally, these tree species are also effective in accumulating toxic heavy metals present in some industrial effluents. In developing countries such as Pakistan, the use of biofuel tree species is gaining popularity not only for harvesting economical and environmentally friendly biofuel, but also to sequester poisonous heavy metals from industrial wastewater. This study was aimed at evaluating the genetic potential of two biofuel species, namely, Jatropha curcas and Pongamia pinnata, to grow when irrigated with industrial effluent from the Pak-Arab Fertilizer Factory Multan, Southern Punjab, Pakistan. The growth performances of one-year-old seedlings of both species were compared in soil with adverse physiochemical properties. It was found that J. curcas was better able to withstand the toxicity of the heavy metals present in the fertilizer factory effluent. J. curcas showed maximum gain in height, diameter, and biomass production in soil irrigated with 75% concentrated industrial effluent. In contrast, P. pinnata showed a significant reduction in growth in soil irrigated with more than 50% concentrated industrial effluent, indicating that this species is less tolerant to higher toxicity levels of industrial effluent. This study identifies J. curcas as a promising biofuel tree species that can be grown using industrial wastewater.

  1. Potential Toxicity and Underlying Mechanisms Associated with Pulmonary Exposure to Iron Oxide Nanoparticles: Conflicting Literature and Unclear Risk

    Directory of Open Access Journals (Sweden)

    Tiffany G. Kornberg

    2017-10-01

    Full Text Available Abstract: Fine/micron-sized iron oxide particulates are incidentally released from a number of industrial processes, including iron ore mining, steel processing, welding, and pyrite production. Some research suggests that occupational exposure to these particulates is linked to an increased risk of adverse respiratory outcomes, whereas other studies suggest that iron oxide is biologically benign. Iron oxide nanoparticles (IONPs, which are less than 100 nm in diameter, have recently surged in use as components of novel drug delivery systems, unique imaging protocols, as environmental catalysts, and for incorporation into thermoplastics. However, the adverse outcomes associated with occupational exposure to IONPs remain relatively unknown. Relevant in vivo studies suggest that pulmonary exposure to IONPs may induce inflammation, pulmonary fibrosis, genotoxicity, and extra-pulmonary effects. This correlates well with in vitro studies that utilize relevant dose, cell type(s, and meaningful end points. A majority of these adverse outcomes are attributed to increased oxidative stress, most likely caused by particle internalization, dissolution, release of free iron ions, and disruption of iron homeostasis. However, because the overall toxicity profile of IONPs is not well understood, it is difficult to set safe exposure limit recommendations that would be adequate for the protection of at-risk workers. This review article will focus on known risks following IONPs exposure supported by human, animal, and cell culture-based studies, the potential challenges intrinsic to IONPs toxicity assessment, and how these may contribute to the poorly characterized IONPs toxicity profile.

  2. Potential Toxicity and Underlying Mechanisms Associated with Pulmonary Exposure to Iron Oxide Nanoparticles: Conflicting Literature and Unclear Risk

    Science.gov (United States)

    Kornberg, Tiffany G.; Antonini, James M.; Rojanasakul, Yon; Castranova, Vincent; Rojanasakul, Liying W.

    2017-01-01

    Fine/micron-sized iron oxide particulates are incidentally released from a number of industrial processes, including iron ore mining, steel processing, welding, and pyrite production. Some research suggests that occupational exposure to these particulates is linked to an increased risk of adverse respiratory outcomes, whereas other studies suggest that iron oxide is biologically benign. Iron oxide nanoparticles (IONPs), which are less than 100 nm in diameter, have recently surged in use as components of novel drug delivery systems, unique imaging protocols, as environmental catalysts, and for incorporation into thermoplastics. However, the adverse outcomes associated with occupational exposure to IONPs remain relatively unknown. Relevant in vivo studies suggest that pulmonary exposure to IONPs may induce inflammation, pulmonary fibrosis, genotoxicity, and extra-pulmonary effects. This correlates well with in vitro studies that utilize relevant dose, cell type(s), and meaningful end points. A majority of these adverse outcomes are attributed to increased oxidative stress, most likely caused by particle internalization, dissolution, release of free iron ions, and disruption of iron homeostasis. However, because the overall toxicity profile of IONPs is not well understood, it is difficult to set safe exposure limit recommendations that would be adequate for the protection of at-risk workers. This review article will focus on known risks following IONPs exposure supported by human, animal, and cell culture-based studies, the potential challenges intrinsic to IONPs toxicity assessment, and how these may contribute to the poorly characterized IONPs toxicity profile. PMID:28984829

  3. Assessment of oral toxicity and safety of pentamethylchromanol (PMCol), a potential chemopreventative agent, in rats and dogs

    International Nuclear Information System (INIS)

    Lindeblad, Matthew; Kapetanovic, Izet M.; Kabirov, Kasim K.; Detrisac, Carol J.; Dinger, Nancy; Mankovskaya, Irina; Zakharov, Alexander; Lyubimov, Alexander V.

    2010-01-01

    lower levels is considered to be less likely to result in toxicity following 28 days of exposure. Sex-related differences were seen in rats. Male rats appeared to have greater sensitivity to nephrotoxicity, while female animals had a greater incidence of hepatoxicity and changes in hematological parameters evaluated, especially at a dose of 500 mg/kg/day, which correlated to the higher plasma drug levels in female rats. It appeared that dogs were generally more sensitive than rats to oral administration of PMCol. Further examination of the potential toxic effects of PMCol in longer term studies is required prior to understanding the full risks of PMCol administration as a chemopreventative agent.

  4. Cobalt toxicity in humans-A review of the potential sources and systemic health effects.

    Science.gov (United States)

    Leyssens, Laura; Vinck, Bart; Van Der Straeten, Catherine; Wuyts, Floris; Maes, Leen

    2017-07-15

    Cobalt (Co) and its compounds are widely distributed in nature and are part of numerous anthropogenic activities. Although cobalt has a biologically necessary role as metal constituent of vitamin B 12 , excessive exposure has been shown to induce various adverse health effects. This review provides an extended overview of the possible Co sources and related intake routes, the detection and quantification methods for Co intake and the interpretation thereof, and the reported health effects. The Co sources were allocated to four exposure settings: occupational, environmental, dietary and medical exposure. Oral intake of Co supplements and internal exposure through metal-on-metal (MoM) hip implants deliver the highest systemic Co concentrations. The systemic health effects are characterized by a complex clinical syndrome, mainly including neurological (e.g. hearing and visual impairment), cardiovascular and endocrine deficits. Recently, a biokinetic model has been proposed to characterize the dose-response relationship and effects of chronic exposure. According to the model, health effects are unlikely to occur at blood Co concentrations under 300μg/l (100μg/l respecting a safety factor of 3) in healthy individuals, hematological and endocrine dysfunctions are the primary health endpoints, and chronic exposure to acceptable doses is not expected to pose considerable health hazards. However, toxic reactions at lower doses have been described in several cases of malfunctioning MoM hip implants, which may be explained by certain underlying pathologies that increase the individual susceptibility for Co-induced systemic toxicity. This may be associated with a decrease in Co bound to serum proteins and an increase in free ionic Co 2+ . As the latter is believed to be the primary toxic form, monitoring of the free fraction of Co 2+ might be advisable for future risk assessment. Furthermore, future research should focus on longitudinal studies in the clinical setting of Mo

  5. Toxicity of sediments potentially contaminated by coal mining and natural gas extraction to unionid mussels and commonly tested benthic invertebrates

    Science.gov (United States)

    Wang, Ning; Ingersoll, Christopher G.; Kunz, James L.; Brumbaugh, William G.; Kane, Cindy M.; Evans, R. Brian; Alexander, Steven; Walker, Craig; Bakaletz, Steve

    2013-01-01

    Sediment toxicity tests were conducted to assess potential effects of contaminants associated with coal mining or natural gas extraction activities in the upper Tennessee River basin and eastern Cumberland River basin in the United States. Test species included two unionid mussels (rainbow mussel, Villosa iris, and wavy-rayed lampmussel, Lampsilis fasciola, 28-d exposures), and the commonly tested amphipod, Hyalella azteca (28-d exposure) and midge, Chironomus dilutus (10-d exposure). Sediments were collected from seven test sites with mussel communities classified as impacted and in proximity to coal mining or gas extraction activities, and from five reference sites with mussel communities classified as not impacted and no or limited coal mining or gas extraction activities. Additional samples were collected from six test sites potentially with high concentrations of polycyclic aromatic hydrocarbons (PAHs) and from a test site contaminated by a coal ash spill. Mean survival, length, or biomass of one or more test species was reduced in 10 of 14 test samples (71%) from impacted areas relative to the response of organisms in the five reference samples. A higher proportion of samples was classified as toxic to mussels (63% for rainbow mussels, 50% for wavy-rayed lampmussels) compared with amphipods (38%) or midge (38%). Concentrations of total recoverable metals and total PAHs in sediments did not exceed effects-based probable effect concentrations (PECs). However, the survival, length, or biomasses of the mussels were reduced significantly with increasing PEC quotients for metals and for total PAHs, or with increasing sum equilibrium-partitioning sediment benchmark toxic units for PAHs. The growth of the rainbow mussel also significantly decreased with increasing concentrations of a major anion (chloride) and major cations (calcium and magnesium) in sediment pore water. Results of the present study indicated that (1) the findings from laboratory tests were generally

  6. Repeat associated non-ATG translation initiation: one DNA, two transcripts, seven reading frames, potentially nine toxic entities!

    Science.gov (United States)

    Pearson, Christopher E

    2011-03-01

    Diseases associated with unstable repetitive elements in the DNA, RNA, and amino acids have consistently revealed scientific surprises. Most diseases are caused by expansions of trinucleotide repeats, which ultimately lead to diseases like Huntington's disease, myotonic dystrophy, fragile X syndrome, and a series of spinocerebellar ataxias. These repeat mutations are dynamic, changing through generations and within an individual, and the repeats can be bi-directionally transcribed. Unsuspected modes of pathogenesis involve aberrant loss of protein expression; aberrant over-expression of non-mutant proteins; toxic-gain-of-protein function through expanded polyglutamine tracts that are encoded by expanded CAG tracts; and RNA-toxic-gain-of-function caused by transcripts harboring expanded CUG, CAG, or CGG tracts. A recent advance reveals that RNA transcripts with expanded CAG repeats can be translated in the complete absence of a starting ATG, and this Repeat Associated Non-ATG translation (RAN-translation) occurs across expanded CAG repeats in all reading frames (CAG, AGC, and GCA) to produce homopolymeric proteins of long polyglutamine, polyserine, and polyalanine tracts. Expanded CTG tracts expressing CUG transcripts also show RAN-translation occurring in all three frames (CUG, UGC, and GCU), to produce polyleucine, polycysteine, and polyalanine. These RAN-translation products can be toxic. Thus, one unstable (CAG)•(CTG) DNA can produce two expanded repeat transcripts and homopolymeric proteins with reading frames (the AUG-directed polyGln and six RAN-translation proteins), yielding a total of potentially nine toxic entities. The occurrence of RAN-translation in patient tissues expands our horizons of modes of disease pathogenesis. Moreover, since RAN-translation counters the canonical requirements of translation initiation, many new questions are now posed that must be addressed. This review covers RAN-translation and some of the pertinent questions.

  7. Repeat associated non-ATG translation initiation: one DNA, two transcripts, seven reading frames, potentially nine toxic entities!

    Directory of Open Access Journals (Sweden)

    Christopher E Pearson

    2011-03-01

    Full Text Available Diseases associated with unstable repetitive elements in the DNA, RNA, and amino acids have consistently revealed scientific surprises. Most diseases are caused by expansions of trinucleotide repeats, which ultimately lead to diseases like Huntington's disease, myotonic dystrophy, fragile X syndrome, and a series of spinocerebellar ataxias. These repeat mutations are dynamic, changing through generations and within an individual, and the repeats can be bi-directionally transcribed. Unsuspected modes of pathogenesis involve aberrant loss of protein expression; aberrant over-expression of non-mutant proteins; toxic-gain-of-protein function through expanded polyglutamine tracts that are encoded by expanded CAG tracts; and RNA-toxic-gain-of-function caused by transcripts harboring expanded CUG, CAG, or CGG tracts. A recent advance reveals that RNA transcripts with expanded CAG repeats can be translated in the complete absence of a starting ATG, and this Repeat Associated Non-ATG translation (RAN-translation occurs across expanded CAG repeats in all reading frames (CAG, AGC, and GCA to produce homopolymeric proteins of long polyglutamine, polyserine, and polyalanine tracts. Expanded CTG tracts expressing CUG transcripts also show RAN-translation occurring in all three frames (CUG, UGC, and GCU, to produce polyleucine, polycysteine, and polyalanine. These RAN-translation products can be toxic. Thus, one unstable (CAG•(CTG DNA can produce two expanded repeat transcripts and homopolymeric proteins with reading frames (the AUG-directed polyGln and six RAN-translation proteins, yielding a total of potentially nine toxic entities. The occurrence of RAN-translation in patient tissues expands our horizons of modes of disease pathogenesis. Moreover, since RAN-translation counters the canonical requirements of translation initiation, many new questions are now posed that must be addressed. This review covers RAN-translation and some of the pertinent

  8. Assessment of potentially toxic metal contamination in the soils of a legacy mine site in Central Victoria, Australia.

    Science.gov (United States)

    Abraham, Joji; Dowling, Kim; Florentine, Singarayer

    2018-02-01

    The environmental impact of toxic metal contamination from legacy mining activities, many of which had operated and were closed prior to the enforcement of robust environmental legislation, is of growing concern to modern society. We have carried out analysis of As and potentially toxic metals (Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, and Zn) in the surface soil of a legacy gold mining site in Maldon, Victoria, Australia, to reveal the status of the current metal concentration. The results revealed the median concentrations of metals from highest to lowest, in the order: Mn > Zn > As > Cr > Cu > Pb > Ni > Co > Hg > Cd. The status of site was assessed directly by comparing the metal concentrations in the study area with known Australian and Victorian average top soil levels and the health investigation levels set by the National Environmental Protection Measures (NEPM) and the Department of Environment and Conservation (DEC) of the State of Western Australia. Although, median concentrations of As, Hg, Pb, Cu and Zn exceeded the average Australian and Victorian top soil concentrations, only As and Hg exceeded the ecological investigation levels (EIL) set by DEC and thus these metals are considered as risk to the human and aquatic ecosystems health due to their increase in concentration and toxicity. In an environment of climate fluctuation with increased storm events and forest fires may mobilize these toxic metals contaminants, pose a real threat to the environment and the community. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Article Commentary: The Pivotal Role of Aldehyde Toxicity in Autism Spectrum Disorder: The Therapeutic Potential of Micronutrient Supplementation

    Directory of Open Access Journals (Sweden)

    Frances Jurnak

    2015-01-01

    Full Text Available Autism spectrum disorder (ASD is characterized by social and communication impairments as well as by restricted, repetitive patterns of behavior and interests. Genomic studies have not revealed dominant genetic errors common to all forms of ASD. So ASD is assumed to be a complex disorder due to mutations in hundreds of common variants. Other theories argue that spontaneous DNA mutations and/or environmental factors contribute to as much as 50% of ASD. In reviewing potential genetic linkages between autism and alcoholism, it became apparent that all theories of ASD are consistent with aldehyde toxicity, in which endogenous and exogenous aldehydes accumulate as a consequence of mutations in key enzymes. Aldehyde toxicity is characterized by cell-localized, micronutrient deficiencies in sulfur-containing antioxidants, thiamine (B1, pyridoxine (B6, folate, Zn 2+ , possibly Mg 2+ , and retinoic acid, causing oxidative stress and a cascade of metabolic disturbances. Aldehydes also react with selective cytosolic and membrane proteins in the cell of origin; then some types migrate to damage neighboring cells. Reactive aldehydes also form adducts with DNA, selectively mutating bases and inducing strand breakage. This article reviews the relevant genomic, biochemical, and nutritional literature, which supports the central hypothesis that most ASD symptoms are consistent with symptoms of aldehyde toxicity. The hypothesis represents a paradigm shift in thinking and has profound implications for clinical detection, treatment, and even prevention of ASD. Insight is offered as to which neurologically afflicted children might successfully be treated with micronutrients and which children are unlikely to be helped. The aldehyde toxicity hypothesis likely applies to other neurological disorders.

  10. Testicular toxicity and sperm quality following copper exposure in Wistar albino rats: ameliorative potentials of L-carnitine.

    Science.gov (United States)

    Khushboo, Maurya; Murthy, Meesala Krishna; Devi, Maibam Sunita; Sanjeev, Sanasam; Ibrahim, Kalibulla Syed; Kumar, Nachimuthu Senthil; Roy, Vikas Kumar; Gurusubramanian, Guruswami

    2018-01-01

    dysfunction [elevation in serum ALT (81.65 vs 48.08 IU/L), AST (156.82 vs 88.25 IU/L), ALP (230.54 vs 148.16 IU/L), urea (12.65 vs 7.45 mmol/L), and creatinine (80.61 vs 48.25 μmol/L) levels], (3) significant decrease in body (99.64 vs 106.09 g) and organ weights (liver-3.48 vs 4.99 g; kidney-429.29 vs 474.78 mg; testes-0.58 vs 0.96 g), (4) imbalance in hormonal and antioxidant enzyme concentrations [significant decline in serum testosterone (0.778 vs 3.226 ng/mL), superoxide dismutase (3.07 vs 8.55 μmol/mg protein), and glutathione-S-transferase (59.28 vs 115.58 nmol/mg protein) levels], (5) severe alterations in the testis histomorphology [sloughed cells (90.65%, score 4 vs 15.65%, score 1), vacuolization (85.95%, score 4 vs 11.45%, score 1), cellular debris along with degenerative characteristics, accentuated germ cell depletion in the seminiferous epithelium, severe damage of spermatogonia and Sertoli cells (73.56%, score 3 vs 0%, score 1)], (6) suppression of spermatogenic process [hypospermatogenesis (low Jhonsen testicular biopsy score 4 vs 9.5), decrease in tubules size (283.75 vs 321.25 μm in diameter), and no. of germ cells (81.8 vs 148.7/100 tubules), Leydig cells (5.2 vs 36.65/100 tubules), and Sertoli cells (8.1 vs 13.5/100 tubules)], (7) sperm transit time was shorter in caput and cauda and ensued in incomplete spermatogenic process and formation of immature sperm leading to infertility, (8) sperm quality was affected significantly [decreased daily sperm production (13.21 vs 26.9 × 10 6 sperms/mL), sperm count (96.12 vs 154.25 × 10 6 /g), sperm viability (26.88 vs 91.65%), and sperm motility (38.48 vs 64.36%)], and (9) increase of head (32.82 vs 2.01%) and tail (14.85 vs 0.14%) morphologic abnormalities and DNA fragmentation index (88.37 vs 11.11%). Oxidative stress and their related events appear to be a potential mechanism involved in copper testicular toxicity and L-carnitine supplementation significantly modulated the possible adverse

  11. Predicting hydrocarbon potential of an earth formation underlying a body of water

    International Nuclear Information System (INIS)

    Kaplan, I.R.; Demaison, G.J.

    1983-01-01

    A method for the on-site collection and examination of small concentrations of methane dissolved in water so as to predict hydrocarbon potential of an earth formation underlying a body of water, said formation being a source of said methane, comprises: (i) sampling the water; (ii) continuously vacuum separating said water into liquid and gas phases; (iii) quantitatively separating interfering gas species from methane; (iv) quantitatively oxidising said methane; (v) cryogenically trapping the resulting gaseous carbon dioxide and water vapor at a trapping station, and (vi) isotopically examining said trapped carbon dioxide and water vapour for carbon and deuterium distribution. (author)

  12. Evaluation of the potential Toxicity and Interaction of Methomyl and Diazinon Insecticides in Male Rats

    International Nuclear Information System (INIS)

    Hanna, L.A.; Fayez, V.

    2003-01-01

    The toxic effect of methomyl and/or diazinon given orally to male rats for 4 consecutive days at the level of 20% of their LD 50 , was investigated. Methomyl did not affect plasma choline esterase (Ch E) after four days of treatment. Serum testosterone, lactate dehydrogenase (LDH), gamma glutamyl transferase (gamma G T) were decreased, while bilirubin alkaline phosphatase (ALP) and uric acid were increased. Serum creatinine phosphokinase (CPK) was increased significantly while creatinine was not affected. Diazinon caused substantial decline in plasma Ch E activity after four days of treatment. Serum creatinine phosphokinase and testosterone were altered significantly while lactate dehydrogenase and creatinine levels were comparable to controls. Serum bilirubin, ALP and uric acid were increased while gamma G T was decreased. Co administration of the two insecticides lowered plasma Ch E activity more than diazinon did. The combined effect on CPK, ALP, testosterone, bilirubin and uric acid was greater than that produced from each insecticide acting independently

  13. Relationship between physico-chemical characteristics and potential toxicity of PM10.

    Science.gov (United States)

    Megido, Laura; Suárez-Peña, Beatriz; Negral, Luis; Castrillón, Leonor; Suárez, Susana; Fernández-Nava, Yolanda; Marañón, Elena

    2016-11-01

    PM10 was sampled at a suburban location affected by traffic and industry in the north of Spain. The samples were analysed to determine the chemical components of PM10 (organic and elemental carbon, soluble chemical species and metals). The aim of this study was to assess the toxicity of PM10 in terms of the bulk analysis and the physico-chemical properties of the particles. Total carbon, sulphates, ammonium, chlorides and nitrates were found to be the major constituents of PM10. The contribution of the last of these was found to increase significantly with PM10 concentration (Pearson coefficient correlation of 0.7, p-value major risk to human health. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Evaluation of antimicrobial activity and toxic potential of extracts and triterpenes isolated from Maytenus imbricata

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Vanessa G.; Duarte, Lucienir P.; Silva, Gracia D.F.; Silva, Fernando C.; Goes, Jefferson V.; Takahashi, Jacqueline A.; Pimenta, Lucia P.S. [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Quimica; Vieira Filho, Sidney A., E-mail: vanessa.greg@yahoo.com [Universidade Federal de Ouro Preto, MG (Brazil). Escola de Farmacia. Dept. de Farmacia

    2012-07-01

    The phyto chemical study of hexane/ethyl ether (1:1) extract of the roots of M. imbricata, Celastraceae, resulted in the isolation and characterization of six known triterpenes: 11{alpha}-hydroxylup-20(29)-en-3-one, previously isolated from this species besides, 3{beta},11{alpha}-di-hydroxylup-20(29)-ene, 3,7-dioxofriedelane, 3-oxo-29-hydroxyfriedelane, tingenone and 6-oxo-tingenol. The chemical structures of these triterpenes were established by spectrometric data (IR, {sup 1}H and {sup 13}C NMR) and through comparison with literature data. The hexane/ethyl ether (1:1), ethyl acetate and methanol extracts, and 11{alpha}-hydroxylup-20(29)-en-3-one, tingenone and 6-oxo-tingenol, showed antimicrobial properties on in vitro assays. All extracts and triterpenes, except 3{beta},11{alpha}-di-hydroxylup-20(29)-ene, presented toxicity demonstrated by the larvicidal effect test using Artemia salina. (author)

  15. Evaluation of antimicrobial activity and toxic potential of extracts and triterpenes isolated from Maytenus imbricata

    Directory of Open Access Journals (Sweden)

    Vanessa G. Rodrigues

    2012-01-01

    Full Text Available The phytochemical study of hexane/ethyl ether (1:1 extract of the roots of M. imbricata, Celastraceae, resulted in the isolation and characterization of six known triterpenes: 11α-hydroxylup-20(29-en-3-one, previously isolated from this species besides, 3β,11α-di-hydroxylup-20(29-ene, 3,7-dioxofriedelane, 3-oxo-29-hydroxyfriedelane, tingenone and 6-oxo-tingenol. The chemical structures of these triterpenes were established by spectrometric data (IR, ¹H and 13C NMR and through comparison with literature data. The hexane/ethyl ether (1:1, ethyl acetate and methanol extracts, and 11α-hydroxylup-20(29-en-3-one, tingenone and 6-oxo-tingenol, showed antimicrobial properties on in vitro assays. All extracts and triterpenes, except 3β,11α-di-hydroxylup-20(29-ene, presented toxicity demonstrated by the larvicidal effect test using Artemia salina.

  16. E-cigarettes as a source of toxic and potentially carcinogenic metals

    International Nuclear Information System (INIS)

    Hess, Catherine Ann; Olmedo, Pablo; Navas-Acien, Ana; Goessler, Walter; Cohen, Joanna E.; Rule, Ana Maria

    2017-01-01

    Background and aims: The popularity of electronic cigarette devices is growing worldwide. The health impact of e-cigarette use, however, remains unclear. E-cigarettes are marketed as a safer alternative to cigarettes. The aim of this research was the characterization and quantification of toxic metal concentrations in five, nationally popular brands of cig-a-like e-cigarettes. Methods: We analyzed the cartomizer liquid in 10 cartomizer refills for each of five brands by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Results: All of the tested metals (cadmium, chromium, lead, manganese and nickel) were found in the e-liquids analyzed. Across all analyzed brands, mean (SD) concentrations ranged from 4.89 (0.893) to 1970 (1540) μg/L for lead, 53.9 (6.95) to 2110 (5220) μg/L for chromium and 58.7 (22.4) to 22,600 (24,400) μg/L for nickel. Manganese concentrations ranged from 28.7 (9.79) to 6910.2 (12,200) μg/L. We found marked variability in nickel and chromium concentration within and between brands, which may come from heating elements. Conclusion: Additional research is needed to evaluate whether e-cigarettes represent a relevant exposure pathway for toxic metals in users. - Highlights: • Certain brands of cig-a-like e-cigarettes contain high levels of nickel and chromium. • Cig-a-likes contain low levels of cadmium, compared to tobacco cigarettes. • Nickel and chromium in the e-liquid of cig-a-likes may come from nichrome heating coils.

  17. Insulin Signaling in Bupivacaine-induced Cardiac Toxicity: Sensitization during Recovery and Potentiation by Lipid Emulsion

    Science.gov (United States)

    Fettiplace, Michael R.; Kowal, Katarzyna; Ripper, Richard; Young, Alexandria; Lis, Kinga; Rubinstein, Israel; Bonini, Marcelo; Minshall, Richard; Weinberg, Guy

    2015-01-01

    Background The impact of local anesthetics on regulation of glucose homeostasis by protein kinase B (Akt) and 5’-Adenosine monophosphate activated protein kinase (AMPK) is unclear but important because of the implications for both local anesthetic toxicity and its reversal by intravenous lipid emulsion (ILE). Methods Sprague-Dawley rats received 10mg/kg bupivacaine over 20 seconds followed by nothing or 10mL/kg ILE (or ILE without bupivacaine). At key time points, heart and kidney were excised. Glycogen content and phosphorylation levels of Akt, p70s6k, s6, IRS1, GSK-3β, AMPK, ACC, TSC2 were quantified. Three animals received Wortmannin to irreversibily inhibit phosphoinositide-3-kinase (Pi3k) signaling. Isolated heart studies were conducted with bupivacaine and LY294002—a reversible Pi3K inhibitor. Results Bupivacaine cardiotoxicity rapidly de-phosphorylated Akt at S473 to 63 ± 5% of baseline and phosphorylated AMPK to 151 ± 19%. AMPK activation inhibited targets downstream of mTORC1 via TSC2. Feedback dephosphorylation of IRS1 to 31 ± 8% of baseline sensitized Akt signaling in hearts resulting in hyper-phosphorylation of Akt at T308 and GSK-3β to 390 ± 64% and 293 ± 50% of baseline respectively. Glycogen accumulated to 142 ± 7% of baseline. Irreversible inhibition of Pi3k upstream of Akt exacerbated bupivacaine cardiotoxicity, while pretreating with a reversible inhibitor delayed onset of toxicity. ILE rapidly phosphorylated Akt at S473 and T308 to 150 ± 23% and 167 ± 10% of baseline, respectively but did not interfere with AMPK or targets of mTORC1. Conclusion Glucose handling by Akt and AMPK is integral to recovery from bupivacaine cardiotoxicity and modulation of these pathways by ILE contributes to lipid resuscitation. PMID:26646023

  18. Factors of Formation of the tax Potential of the Securities Market

    Directory of Open Access Journals (Sweden)

    Gumenniy Anatoliy A.

    2014-02-01

    Full Text Available The article is devoted to the problems of identification of factors that influence volumes and dynamics of the tax potential of the securities market. The goal of the article is detection and systematisation of factors of formation and realisation of the tax potential of the securities market. In the result of the conducted study it systemises factors of formation and realisation of the tax potential of the securities market by two groups: economic and legislatory organisational. The main of the economic factors are: state of economic development, degree of the shadow economy, level of savings of the population, level of trust of the population and level of inflation. The article justifies interconnection that exist between the said factors and volumes of the tax potential of the securities market. In particular, it proves that increase of volumes of the shadow economy facilitates reduction of the tax potential of the securities market, since it facilitates outflow of capital from the official sector of economy. Growth of unorganised savings of the population, the volume of which grows proportionally to the growth of the level of distrust of the population to the securities market, has a negative impact on formation of the tax potential of the securities market. Degree of the negative impact of the said factors grows in the event of deterioration of the state of the macro-economic situation and growth of inflation. The legislatory organisational factors are: object, base, rates of taxation of securities trading and the securities market infrastructure. The article proves that low level of infrastructure development could significantly reduce the tax potential of the securities market. The proposed approach to the study of factors of formation of the tax potential gives a possibility to mark out, apart from de-shadowing of operations and expansion of the taxation base, one more direction on increase of the tax potential of the securities market

  19. Potential Biomarkers for Radiation-Induced Renal Toxicity following 177Lu-Octreotate Administration in Mice.

    Directory of Open Access Journals (Sweden)

    Emil Schüler

    Full Text Available The kidneys are one of the main dose-limiting organs in peptide receptor radionuclide therapy and due to large inter-individual variations in renal toxicity, biomarkers are urgently needed in order to optimize therapy and reduce renal tissue damage. The aim of this study was to investigate the transcriptional, functional, and morphological effects on renal tissue after 177Lu-octreotate administration in normal mice, and to identify biomarkers for radiation induced renal toxicity.C57BL/6N mice were i.v. injected with 0, 30, 60, 90, 120, or 150 MBq 177Lu-octreotate (0, 16, 29, 40, 48, and 54 Gy to the kidneys. At 4, 8, and 12 months after administration, radiation-induced effects were evaluated in relation to (a global transcriptional variations in kidney tissues, (b morphological changes in the kidneys, (c changes in white and red blood cell count as well as blood levels of urea, and (d changes in renal function using 99mTc-DTPA/99mTc-DMSA scintigraphy.In general, the highest number of differentially regulated transcripts was observed at 12 months after administration. The Cdkn1a, C3, Dbp, Lcn2, and Per2 genes displayed a distinct dose-dependent regulation, with increased expression level with increasing absorbed dose. Ifng, Tnf, and Il1B were identified as primary up-stream regulators of the recurrently regulated transcripts. Furthermore, previously proposed biomarkers for kidney injury and radiation damage were also observed. The functional investigation revealed reduced excretion of 99mTc-DTPA after 150 MBq, an increased uptake of 99mTc-DMSA at all dose levels compared with the controls, and markedly increased urea level in blood after 150 MBq at 12 months.Distinct dose-response relationships were found for several of the regulated transcripts. The Cdkn1a, Dbp, Lcn2, and Per2 genes are proposed as biomarkers for 177Lu-octreotate exposure of kidney. Correlations to functional and morphological effects further confirm applicability of these

  20. Sphygmomanometers and thermometers as potential fomites of Staphylococcus haemolyticus: biofilm formation in the presence of antibiotics.

    Science.gov (United States)

    Sued, Bruna Pinto Ribeiro; Pereira, Paula Marcele Afonso; Faria, Yuri Vieira; Ramos, Juliana Nunes; Binatti, Vanessa Batista; Santos, Kátia Regina Netto Dos; Seabra, Sérgio Henrique; Hirata, Raphael; Vieira, Verônica Viana; Mattos-Guaraldi, Ana Luíza; Pereira, José Augusto Adler

    2017-03-01

    The association between Staphylococcus haemolyticus and severe nosocomial infections is increasing. However, the extent to which fomites contribute to the dissemination of this pathogen through patients and hospital wards remains unknown. In the present study, sphygmomanometers and thermometers were evaluated as potential fomites of oxacillin-resistant S. haemolyticus (ORSH). The influence of oxacillin and vancomycin on biofilm formation by ORSH strains isolated from fomites was also investigated. The presence of ORSH on swabs taken from fomite surfaces in a Brazilian hospital was assessed using standard microbiological procedures. Antibiotic susceptibility profiles were determined by the disk diffusion method, and clonal distribution was assessed in pulsed-field gel electrophoresis (PFGE) assays. Minimum inhibitory concentrations (MICs) of oxacillin and vancomycin were evaluated via the broth microdilution method. Polymerase chain reaction (PCR) assays were performed to detect the mecA and icaAD genes. ORSH strains grown in media containing 1/4 MIC of vancomycin or oxacillin were investigated for slime production and biofilm formation on glass, polystyrene and polyurethane catheter surfaces. ORSH strains comprising five distinct PFGE types were isolated from sphygmomanometers (n = 5) and a thermometer (n = 1) used in intensive care units and surgical wards. ORSH strains isolated from fomites showed susceptibility to only linezolid and vancomycin and were characterised as multi-drug resistant (MDR). Slime production, biofilm formation and the survival of sessile bacteria differed and were independent of the presence of the icaAD and mecA genes, PFGE type and subtype. Vancomycin and oxacillin did not inhibit biofilm formation by vancomycin-susceptible ORSH strains on abiotic surfaces, including on the catheter surface. Enhanced biofilm formation was observed in some situations. Moreover, a sub-lethal dose of vancomycin induced biofilm formation by an ORSH strain on

  1. Analysis of the potential formation of a Breccia chimney beneath the WIPP repository

    International Nuclear Information System (INIS)

    Spiegler, P.

    1982-05-01

    This report evaluates the potential formation of a Breccia pipe beginning at the Bell Canyon aquifer beneath the WIPP repository and the resulting release of radioactivity to the surface. Rock mechanics considerations indicate that the formation of a Breccia pipe by collapse of a cavern is not reasonable. Even if rock mechanics is ignored, the overlying strata act as a barrier and would prevent the release of radioactivity to the biosphere. Gradual formation of a Breccia pipe is so slow that the plutonium-239 in the waste (one of the most important long-lived components) would decay during formation. If Bell Lake and San Simon Sinks are the surface manifestation of a regional deep dissolution wedge, such a wedge is too far removed to represent pipe forming activity near the WIPP site. The formation of a Breccia pipe under the WIPP repository is highly unlikely. If it did occur, the concentration of plutonium-239 in brine reaching the surface would be less than the maximum permissible concentration in water specified in the Code of Federal Regulation Title 10, part 20

  2. NODC Standard Format Marine Toxic Substances and Pollutants (F144) Data (1971-1989) (NODC Accession 0014199)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data type contains data on ambient concentrations of toxic substances and other pollutants in the marine environment. The data derive from laboratory analyses...

  3. Evaluation of toxic potential of acephate and chlorpyrifos by dominant lethal test on Culex quinquefasciatus.

    Science.gov (United States)

    Bhinder, Preety; Chaudhry, Asha

    2013-05-01

    The present paper deals with the toxicity evaluation of pesticides acephate and chlorpyrifos by applying dominant lethal test (DLT) on mosquito Culex quinquefasciatus taken as an experimental model. For this, the adult male mosquitoes emerging from LC20 treated larval stock were allowed to crossmate with normal virgin females under controlled conditions of mosquito rearing laboratory along with the parallel controls, separately for each pesticide. The eggs obtained from such females were allowed to hatch after which they were examined under suitable magnification. The number of unhatched eggs was taken as the measure for calculating the dominant lethality caused by the pesticides and the data was analyzed statistically by applying Student's t-test. The statistical analysis of the results for acephate treated groups was 9.49 +/- 1.50 as against 3.92 +/- 0.41 in the control groups and chlorpyrifos treated groups gave the value 9.94 +/- 1.92 as against 4.26 +/- 0.35 in the control groups. The results indicated that these pesticides induced significant (p < 0.05) dominant lethality.

  4. Toxicity potential of residual ethylene oxide on fresh or frozen embryos maintained in plastic straws.

    Science.gov (United States)

    Schiewe, M C; Schmidt, P M; Pontbriand, D; Wildt, D E

    1988-01-01

    The toxic effects of residual ethylene oxide (EtO), a frequently used gas-sterilant, on embryos either frozen for long-term purposes or stored acutely for 30 min to 9 hr in a fresh condition in 0.25-ml straw containers were evaluated. In Experiment 1, fresh embryos were frozen (using conventional technology) in straws previously aerated for 0 hr to 8 mo after EtO sterilization. With the exception of the 8-mo group in which survival and quality ratings were depressed, embryo viability was not affected significantly by short-term prefreeze and post-thaw exposure to EtO residues. Experiment 2 was conducted to analyze the influence of prefreeze exposure to EtO residues on embryo development in vitro for embryos temporarily stored in previously sterilized straws aerated for different intervals. Compared to non-EtO-sterilized control straws, the development, quality, and viability of embryos exposed to EtO-treated straws were compromised (p less than 0.05) as the aeration interval decreased and the exposure interval increased. The combined results of both experiments indicate that EtO-treated straws can be used to cryopreserve gametes efficiently, but only if the aeration interval is greater than or equal to 72 hr and the prefreeze duration of exposure is less than or equal to 3 hr.

  5. The Human Stratum Corneum Prevents Small Gold Nanoparticle Penetration and Their Potential Toxic Metabolic Consequences

    Directory of Open Access Journals (Sweden)

    David C. Liu

    2012-01-01

    Full Text Available Nanoparticles are being used in multiple applications, ranging from biomedical and skin care products (e.g., sunscreen through to industrial manufacturing processes (e.g., water purification. The increase in exposure has led to multiple reports on nanoparticle penetration and toxicity. However, the correlation between nanoparticle size and its penetration without physical/chemical enhancers through the skin is poorly understood—with studies instead focusing primarily on skin penetration under disrupted conditions. In this paper, we investigate the penetration and metabolic effects of 10 nm, 30 nm, and 60 nm gold nanoparticles within viable excised human skin after 24-hour exposure using multiphoton tomograph-fluorescence lifetime imaging microscopy. After 24 hour treatment with the 10, 30, and 60 nm gold nanoparticles, there was no significant penetration detected below the stratum corneum. Furthermore, there were no changes in metabolic output (total NAD(PH in the viable epidermis posttreatment correlating with lack of penetration of nanoparticles. These results are significant for estimating topical nanoparticle exposure in humans where other model systems may overestimate the exposure of nanoparticles to the viable epidermis. Our data shows that viable human skin resists permeation of small nanoparticles in a size range that has been reported to penetrate deeply in other skin models.

  6. Chlorinated Phospholipids and Fatty Acids: (Pathophysiological Relevance, Potential Toxicity, and Analysis of Lipid Chlorohydrins

    Directory of Open Access Journals (Sweden)

    Jenny Schröter

    2016-01-01

    Full Text Available Chlorinated phospholipids are formed by the reaction of hypochlorous acid (HOCl, generated by the enzyme myeloperoxidase under inflammatory conditions, and the unsaturated fatty acyl residues or the head group. In the first case the generated chlorohydrins are both proinflammatory and cytotoxic, thus having a significant impact on the structures of biomembranes. The latter case leads to chloramines, the properties of which are by far less well understood. Since HOCl is also widely used as a disinfecting and antibacterial agent in medicinal, industrial, and domestic applications, it may represent an additional source of danger in the case of abuse or mishandling. This review discusses the reaction behavior of in vivo generated HOCl and biomolecules like DNA, proteins, and carbohydrates but will focus on phospholipids. Not only the beneficial and pathological (toxic effects of chlorinated lipids but also the importance of these chlorinated species is discussed. Some selected cleavage products of (chlorinated phospholipids and plasmalogens such as lysophospholipids, (chlorinated free fatty acids and α-chloro fatty aldehydes, which are all well known to massively contribute to inflammatory diseases associated with oxidative stress, will be also discussed. Finally, common analytical methods to study these compounds will be reviewed with focus on mass spectrometric techniques.

  7. A preliminary assessment of the toxic and mutagenic potential of steroidal alkaloids in transgenic mice.

    Science.gov (United States)

    Crawford, L; Myhr, B

    1995-03-01

    Impregnated CD2 transgenic mice, which contain multiple copies of a lambda gt10lacZ construct integrated into the genome of each cell, were given a predetermined estimated maximum tolerated dose of several steroidal alkaloids: Solanum glycoalkaloids from potato, alpha-chaconine and alpha-solanine; aglycones, solanidine and solasodine, and a Veratrum alkaloid, jervine. Observations were made of dams and foetuses for indications of toxicity and/or terata; some dam livers and foetuses were assayed for mutagenicity using the lacZ gene. Other dams were gavaged with a single dose of 75 mg all-trans-retinol/kg to serve as a reference teratogen. Unexpectedly, this level of retinol was not clearly teratogenic. The results of both positive and non-positive selection systems showed that the mutation frequencies in the livers of the dams dosed with alpha-chaconine, alpha-solanine and solanidine were three to four times higher than historically normal in the livers of this transgenic mouse strain.

  8. Development of Comparative Toxicity Potentials of TiO2 Nanoparticles for Use in Life Cycle Assessment

    DEFF Research Database (Denmark)

    Ettrup, Kim; Kounina, Anna; Hansen, Steffen Foss

    2017-01-01

    for TiO2 nanoparticles (TiO2-NP) for use in LCA. We adapted the USEtox 2.0 consensus model to integrate the SimpleBox4Nano fate model, and we populated the resulting model with TiO2-NP specific data. We thus calculated CTP values for TiO2 nanoparticles for air, water, and soil emission compartments...... in earlier studies. Assumptions, which were performed in those previous studies because of lack of data and knowledge at the time they were made, primarily explain such discrepancies. For future assessment of potential toxic impacts of TiO2 nanoparticles in LCA studies, we therefore recommend the use of our......Studies have shown that releases of nanoparticles may take place through the life cycle of products embedding nanomaterials, thus resulting in potential impacts on ecosystems and human health. While several life cycle assessment (LCA) studies have assessed such products, only a few of them have...

  9. Measuring H+ pumping and membrane potential formation in sealed membrane vesicle systems

    DEFF Research Database (Denmark)

    Wielandt, Alex Green; Palmgren, Michael Broberg; Fuglsang, Anja Thoe

    2016-01-01

    is not converted into a product and only moves a few nanometers in space. Here, we describe two methods for the measurement of active proton pumping across lipid bilayers and the concomitant formation of a membrane potential, applying the dyes 9-amino-6-chloro-2-methoxyacridine (ACMA) and oxonol VI. The methods...... are exemplified by assaying transport of the Arabidopsis thaliana plasma membrane H(+)-ATPase (proton pump), which after heterologous expression in Saccharomyces cerevisiae and subsequent purification has been reconstituted in proteoliposomes....

  10. Non-potential Field Formation in the X-shaped Quadrupole Magnetic Field Configuration

    Energy Technology Data Exchange (ETDEWEB)

    Kawabata, Y.; Shimizu, T. [Department of Earth and Planetary Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Inoue, S., E-mail: kawabata.yusuke@ac.jaxa.jp [Max-Planck-Institute for Solar System Research, Justus-von-Liebig-Weg 3 D-37077 Göttingen (Germany)

    2017-06-20

    Some types of solar flares are observed in X-shaped quadrupolar field configuration. To understand the magnetic energy storage in such a region, we studied non-potential field formation in an X-shaped quadrupolar field region formed in the active region NOAA 11967, which produced three X-shaped M-class flares on 2014 February 2. Nonlinear force-free field modeling was applied to a time series of vector magnetic field maps from the Solar Optical Telescope on board Hinode and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory . Our analysis of the temporal three-dimensional magnetic field evolution shows that the sufficient free energy had already been stored more than 10 hr before the occurrence of the first M-class flare and that the storage was observed in a localized region. In this localized region, quasi-separatrix layers (QSLs) started to develop gradually from 9 hr before the first M-class flare. One of the flare ribbons that appeared in the first M-class flare was co-spatial with the location of the QSLs, suggesting that the formation of the QSLs is important in the process of energy release. These QSLs do not appear in the potential field calculation, indicating that they were created by the non-potential field. The formation of the QSLs was associated with the transverse photospheric motion of the pre-emerged flux and the emergence of a new flux. This observation indicates that the occurrence of the flares requires the formation of QSLs in the non-potential field in which free magnetic energy is stored in advance.

  11. Large distance modification of Newtonian potential and structure formation in universe

    Science.gov (United States)

    Hameeda, Mir; Upadhyay, Sudhaker; Faizal, Mir; Ali, Ahmed F.; Pourhassan, Behnam

    2018-03-01

    In this paper, we study the effects of super-light brane world perturbative modes on structure formation in our universe. As these modes modify the large distance behavior of Newtonian potential, they effect the clustering of a system of galaxies. So, we explicitly calculate the clustering of galaxies interacting through such a modified Newtonian potential. We use a suitable approximation for analyzing this system of galaxies, and discuss the validity of such approximations. We observe that such corrections also modify the virial theorem for such a system of galaxies.

  12. Radio advertising on the Internet. Characteristics, potential and its main formats

    Directory of Open Access Journals (Sweden)

    Teresa Piñeiro-Otero

    2015-11-01

    Full Text Available The sound character of radio messages and its particularities provide this medium with great potential in consumption and multitasking environments and engagement ability. Despite this, the tiny creative on ads, the limited perception of its value as an advertising medium, and the entity reached by Internet have moved conventional radio into last positions on advertising investment. This weight loss in the global advertising market contrasts with the strengths of the radio, which, in its Network transposition, have increased and resized. In this sense, this paper aims to make an approach to the characteristics of radio advertising, to the specific potential of online radio and to the main formats.

  13. XML-BSPM: an XML format for storing Body Surface Potential Map recordings.

    Science.gov (United States)

    Bond, Raymond R; Finlay, Dewar D; Nugent, Chris D; Moore, George

    2010-05-14

    The Body Surface Potential Map (BSPM) is an electrocardiographic method, for recording and displaying the electrical activity of the heart, from a spatial perspective. The BSPM has been deemed more accurate for assessing certain cardiac pathologies when compared to the 12-lead ECG. Nevertheless, the 12-lead ECG remains the most popular ECG acquisition method for non-invasively assessing the electrical activity of the heart. Although data from the 12-lead ECG can be stored and shared using open formats such as SCP-ECG, no open formats currently exist for storing and sharing the BSPM. As a result, an innovative format for storing BSPM datasets has been developed within this study. The XML vocabulary was chosen for implementation, as opposed to binary for the purpose of human readability. There are currently no standards to dictate the number of electrodes and electrode positions for recording a BSPM. In fact, there are at least 11 different BSPM electrode configurations in use today. Therefore, in order to support these BSPM variants, the XML-BSPM format was made versatile. Hence, the format supports the storage of custom torso diagrams using SVG graphics. This diagram can then be used in a 2D coordinate system for retaining electrode positions. This XML-BSPM format has been successfully used to store the Kornreich-117 BSPM dataset and the Lux-192 BSPM dataset. The resulting file sizes were in the region of 277 kilobytes for each BSPM recording and can be deemed suitable for example, for use with any telemonitoring application. Moreover, there is potential for file sizes to be further reduced using basic compression algorithms, i.e. the deflate algorithm. Finally, these BSPM files have been parsed and visualised within a convenient time period using a web based BSPM viewer. This format, if widely adopted could promote BSPM interoperability, knowledge sharing and data mining. This work could also be used to provide conceptual solutions and inspire existing formats

  14. Potential citric acid exposure and toxicity to Hawaiian hoary bats (Lasiurus cinereus semotus) associated with Eleutherodactylus frog control.

    Science.gov (United States)

    Pitt, William C; Witmer, Gary W; Jojola, Susan M; Sin, Hans

    2014-04-01

    We examined potential exposure of Hawaiian hoary bats (Lasiurus cinereus semotus) to citric acid, a minimum risk pesticide registered for control of invasive Eleutherodactylus frog populations. Hoary bats are nocturnal insectivores that roost solitarily in foliage, federally listed as endangered, and are endemic to Hawaii. Oral ingestion during grooming of contaminated fur appears to be the principal route by which these bats might be exposed to citric acid. We made assessments of oral toxicity, citric acid consumption, retention of material on fur, and grooming using big brown bats (Eptesicus fuscus) as a surrogate species. We evaluated both ground application and aerial application of 16 % solutions of citric acid during frog control operations. Absorbent bat effigies exposed to ground and aerial operational spray applications retained means of 1.54 and 0.02 g, respectively, of dry citric acid, although retention by the effigies was much higher than bat carcasses drenched in citric acid solutions. A high dose delivered orally (2,811 mg/kg) was toxic to the big brown bats and emesis occurred in 1 bat dosed as low as the 759 mg/kg level. No effect was observed with the lower doses examined (≤ 542 mg/kg). Bats sprayed with 5 ml of 16 % (w/w) citric acid solution showed no evidence of intoxication. In field situations, it is unlikely that bats would be sprayed directly or ingest much citric acid retained by fur. Based on our observations, we believe Hawaiian hoary bats to be at very low risk from harmful exposure to a toxic dose of citric acid during frog control operations.

  15. Assessment of toxicity potential of metallic elements in discarded electronics: a case study of mobile phones in China.

    Science.gov (United States)

    Wu, B Y; Chan, Y C; Middendorf, A; Gu, X; Zhong, H W

    2008-01-01

    The electronic waste (e-waste) is increasingly flooding Asia, especially China. E-waste could precipitate a growing volume of toxic input to the local environment if it was not handed properly. This makes the evaluation of environmental impact from electronics an essentially important task for the life cycle assessment (LCA) and the end-of-life management of electronic products. This study presented a quantitative investigation on the environmental performance of typical electronics. Two types of disposed mobile phones (MPs), as a representative of consumer electronics, were evaluated in terms of toxicity potential indicator (TPI) with an assumption of worst-case scenario. It is found that the composition and the percentages of constituents in MPs are similar. More than 20 metallic elements make up 35 wt.%-40 wt.% of the total weight, of which 12 elements are identified to be highly hazardous and 12 are less harmful. With the TPI technique, the environmental performance of Pb is attributed to be 20.8 mg(-1). The total TPIs of metallic elements in the old and new type MP is 255,403 and 127,639 units, respectively, which is equivalent to the effect of releasing 6.14 and 12.28 g Pb into the environment. The average TPI of the old and new type MP is 4.1 and 4.5 mg(-1), respectively, which suggests a similar eco-efficiency per unit mass. The new model of MP is more eco-effective than the old one, which is not due to a reduction in the type of hazardous elements, but rather due to a significant miniaturization of the package with less weight. A single MP can have a considerable toxicity to the environment as referred to Pb, which suggests a major concern for the environmental impact of the total e-waste with a huge quantity and a heavy mass in China.

  16. THE ARDUOUS JOURNEY TO BLACK HOLE FORMATION IN POTENTIAL GAMMA-RAY BURST PROGENITORS

    International Nuclear Information System (INIS)

    Dessart, Luc; O'Connor, Evan; Ott, Christian D.

    2012-01-01

    We present a quantitative study on the properties at death of fast-rotating massive stars evolved at low-metallicity—objects that are proposed as likely progenitors of long-duration γ-ray bursts (LGRBs). We perform one-dimensional+rotation stellar-collapse simulations on the progenitor models of Woosley and Heger, and critically assess their potential for the formation of a black hole and a Keplerian disk (namely, a collapsar) or a proto-magnetar. We note that theoretical uncertainties in the treatment of magnetic fields and the approximate handling of rotation compromise the accuracy of stellar-evolution models. We find that only the fastest rotating progenitors achieve sufficient compactness for black hole formation while the bulk of models possess a core density structure typical of garden-variety core-collapse supernova (SN) progenitors evolved without rotation and at solar metallicity. Of the models that do have sufficient compactness for black hole formation, most of them also retain a large amount of angular momentum in the core, making them prone to a magneto-rotational explosion, therefore preferentially leaving behind a proto-magnetar. A large progenitor angular-momentum budget is often the sole criterion invoked in the community today to assess the suitability for producing a collapsar. This simplification ignores equally important considerations such as the core compactness, which conditions black hole formation, the core angular momentum, which may foster a magneto-rotational explosion preventing black hole formation, or the metallicity and the residual envelope mass which must be compatible with inferences from observed LGRB/SNe. Our study suggests that black hole formation is non-trivial, that there is room for accommodating both collapsars and proto-magnetars as LGRB progenitors, although proto-magnetars seem much more easily produced by current stellar-evolutionary models.

  17. An investigation of enzymatic detergents as a potential cause of toxic anterior segment syndrome.

    Science.gov (United States)

    Leder, Henry A; Goodkin, Margot; Buchen, Shelley Y; Calogero, Don; Hilmantel, Gene; Hitchins, Victoria M; Eydelman, Malvina B

    2012-07-01

    To investigate whether enzymatic detergents used in cleaning ophthalmic surgical instruments can cause toxic anterior segment syndrome (TASS)-like responses in a rabbit model. Randomized, investigator-masked, controlled experimental animal study. Thirty-five New Zealand white rabbits. The rabbit eyes were randomized into 7 treatment groups to receive intracameral injection of 1 of 3 different doses of Medline Dual Detergent or Enzol Detergent, or sterile limulus amoebocyte lysate reagent water as a control. The eyes were evaluated for anterior segment inflammation at baseline and at 1, 3, 6, 24, 48, and 72 hours after treatment by slit-lamp biomicroscopy. Anterior chamber (AC) inflammation, including cells, flare, fibrin, and iris injection; time course of inflammation; and residual detergent levels in luminated instruments. Moderate to marked injection of the iris vessels was seen as early as 1 hour after treatment with the enzymatic detergents in 41 of 60 eyes, with the response being more severe in the Enzol Detergent-exposed eyes. Severe iris hemorrhages were accompanied by blood in the AC in 13 eyes, which usually persisted through 72 hours, with an associated increase in AC cell and flare. Corneal haze was present in 52 of 56 eyes 1 hour after treatment, but was mild and resolved within 24 hours in all but the Enzol 4.5%-exposed eyes. Median AC cell and flare peaked at 6 hours and resolved by 48 hours. Enzymatic detergents caused a severe but unusual response from the iris when injected intracamerally into rabbit eyes. This response has not been reported in humans with TASS. The time course of inflammation was faster (peak at 6 hours) and resolved more quickly (within 48 hours) than TASS. Simulated cleaning and extraction studies indicate that the level of residual detergent to which a patient could be exposed is significantly less than the lowest dose used in this study. Because that low dose caused no significant observations other than injection of the

  18. Field measurements of the ambient ozone formation potential in Beijing during winter

    Science.gov (United States)

    Crilley, Leigh; Kramer, Louisa; Thomson, Steven; Lee, James; Squires, Freya; Bloss, William

    2017-04-01

    The air quality issues in Beijing have been well-documented, and the severe air pollution levels result in a unique chemical mix in the urban boundary layer, both in terms of concentration and composition. As many of the atmospheric chemical process are non-linear and interlinked, this makes predictions difficult for species formed in atmosphere, such as ozone, requiring field measurements to understand these processes in order to guide mitigation efforts. To investigate the ozone formation potential of ambient air, we employed a custom built instrument to measure in near real time the potential for in situ ozone production, using an artificial light source. Our results are thus indicative of the ozone formation potential for the sampled ambient air mixture. Measurements were performed as part of the Air Pollution and Human Health (APHH) field campaign in November / December 2016 at a suburban site in central Beijing. We also conducted experiments to examine the ozone production sensitivity to NOx. We will present preliminarily results from ambient sampling and NOx experiments demonstrating changes in the ozone production potential during clean and haze periods in Beijing.

  19. Pollution and health risk of potentially toxic metals in urban road dust in Nanjing, a mega-city of China

    International Nuclear Information System (INIS)

    Liu, Enfeng; Yan, Ting; Birch, Gavin; Zhu, Yuxin

    2014-01-01

    Spatial variations in concentrations of a suite of potentially toxic metals (Ba, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and Ca in road dusts (n = 99) from urban trunk roads (TR) in Nanjing, a mega-city in China, were established. Metal pollution levels, sources and human health risk (non-carcinogenic) were studied. In contrast to previous studies, we labeled the indicative metals relating to non-exhaust traffic emissions by comparing metal pollution between crossroad and park road dusts, and then anthropogenic sources of metals in TR dusts were assessed combining their spatial pollution patterns, principal component analysis and Pb isotopic compositions. Results showed that the metals were enriched in TR dusts compared to background soil concentrations with mean enrichment factors (EFs) of 2.2–23, indicating considerable anthropogenic influence. The degrees of metal pollution ranged from minimal to extremely high and ranked by Ca > Cu > Pb ≈ Zn > Cr ≈ Fe > Ni ≈ Ba > Mn on average. Pollution of Cr, Cu, Fe, Mn, Ni, Pb and Zn in TR dusts resulted primarily from industrial emissions (e.g., coal combustion and smelting) and high pollution levels were found close to suburb industrial complexes, whereas pollution of Ba and Ca was mainly related to construction/demolition sources and was generally distributed homogeneously. The relatively minor contribution of non-exhaust traffic emissions to metal pollution in TR dusts was considered to be due to overwhelming industrial and construction/demolition contributions, as well as to the dilution effect of natural soil particles. Ingestion appears to be the major route of exposure for road dust for both adults and children, followed by dermal contact. The non-carcinogenic health risk resulting from exposure to the potentially toxic metals in TR dusts was within the safe level based on the Hazard Index (HI), except in pollution hotspots where exposure to Pb, Cr, and Cu may be hazardous to children. - Highlights: • Pollution and

  20. Endophytes and their Potential to Deal with Co-contamination of Organic Contaminants (Toluene) and Toxic Metals (Nickel) during Phytoremediation

    Energy Technology Data Exchange (ETDEWEB)

    Weyens, N.; van der Lelie, D.; Truyens, S.; Saenen, E.; Boulet, J.; Dupae, J.; Taghavi, S.; Carleer, R.; Vangronsveld, J.

    2011-01-15

    The aim was to investigate if engineered endophytes that are capable of degrading organic contaminants, and deal with or ideally improve uptake and translocation of toxic metals, can improve phytoremediation of mixed organic-metal pollution. As a model system, yellow lupine was inoculated with the endophyte Burkholderia cepacia VM1468 possessing (a) the pTOM-Bu61 plasmid, coding for constitutive toluene/TCE degradation, and (b) the chromosomally inserted ncc-nre Ni resistance/sequestration system. As controls, plants were inoculated with B. vietnamiensis BU61 (pTOM-Bu61) and B. cepacia BU72 (containing the ncc-nre Ni resistance/sequestration system). Plants were exposed to mixes of toluene and Ni. Only inoculation with B. cepacia VM1468 resulted in decreased Ni and toluene phytotoxicity, as measured by a protective effect on plant growth and decreased activities of enzymes involved in antioxidative defence (catalase, guaiacol peroxidase, superoxide dismutase) in the roots. Besides, plants inoculated with B. cepacia VM1468 and B. vietnamiensis BU61 released less toluene through the leaves than non-inoculated plants and those inoculated with B. cepacia BU72. Ni-uptake in roots was slightly increased for B. cepacia BU72 inoculated plants. These results indicate that engineered endophytes have the potential to assist their host plant to deal with co-contamination of toxic metals and organic contaminants during phytoremediation.

  1. Toxic potential of organic constituents of submicron particulate matter (PM1) in an urban road site (Barcelona).

    Science.gov (United States)

    Mesquita, Sofia R; van Drooge, Barend L; Dall'Osto, Manuel; Grimalt, Joan O; Barata, Carlos; Vieira, Natividade; Guimarães, Laura; Piña, Benjamin

    2017-06-01

    Atmospheric particulate matter (PM) is a recognized risk factor contributing to a number of diseases in human populations and wildlife globally. Organic matter is a major component of PM, but its contribution to overall toxicity of PM has not been thoroughly evaluated yet. In the present work, the biological activity of organic extracts from PM1 (particles with less than 1 μm of aerodynamic diameter) collected from an urban road site in the centre of Barcelona (NE Spain) was evaluated using a yeast-based assay (AhR-RYA) and different gene expression markers in zebrafish embryos. Dioxin-like activity of the extracts correlated to primary emissions from local traffic exhausts, reflecting weekday/weekend alternance. Expression levels of cyp1a and of gene markers for key cellular processes and development (ier2, fos) also correlated to vehicle emissions, whereas expression of gene markers related to antioxidant defence and endocrine effects (gstal, hao1, ttr) was strongly reduced in samples with strong contribution from regional air masses with aged secondary organic species or with strong influence of biomass burning emissions. Our data suggest that the toxic potential of PM1 organic chemical constituents strongly depends on the emission sources and on the process of ageing from primary to secondary organic aerosols.

  2. DDTs in rice frogs (Rana limnocharis) from an agricultural site, South China: tissue distribution, biomagnification, and potential toxic effects assessment.

    Science.gov (United States)

    Wu, Jiang-Ping; Zhang, Ying; Luo, Xiao-Jun; Chen, She-Jun; Mai, Bi-Xian

    2012-04-01

    Contamination with agricultural pesticides such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD), is among several proposed stressors contributing to the global declines in amphibian populations and species biodiversity. These chemicals were examined in insects and in the muscle, liver, and eggs of rice frogs (Rana limnocharis) from the paddy fields of an agricultural site in South China. The ΣDDT (sum of DDT, DDE, and DDD) concentrations ranged from 154 to 915, 195 to 1,400, and 165 to 1,930 ng/g lipid weight in the muscle, liver, and eggs, respectively. All the DDTs (DDT, DDE, and DDD) showed higher affinity for the liver relative to muscle tissue and can be maternally transferred to eggs in female frogs. The average biomagnification factors for DDTs ranged from 1.6 to 1.9 and 1.5 to 2.9 in female and male frogs, respectively, providing clear evidence of their biomagnification from insects to frogs. Compared with the reported DDT levels demonstrated to have toxic effects on frogs, DDTs in the present frogs are unlikely to constitute an immediate health risk. However, the adverse impacts of high DDT residues in eggs on the hatching success and their potential toxicity to the newly metamorphosed larval frogs should be assessed further. Copyright © 2011 SETAC.

  3. Metabolomics approach reveals metabolic disorders and potential biomarkers associated with the developmental toxicity of tetrabromobisphenol A and tetrachlorobisphenol A

    Science.gov (United States)

    Ye, Guozhu; Chen, Yajie; Wang, Hong-Ou; Ye, Ting; Lin, Yi; Huang, Qiansheng; Chi, Yulang; Dong, Sijun

    2016-10-01

    Tetrabromobisphenol A and tetrachlorobisphenol A are halogenated bisphenol A (H-BPA), and has raised concerns about their adverse effects on the development of fetuses and infants, however, the molecular mechanisms are unclear, and related metabolomics studies are limited. Accordingly, a metabolomics study based on gas chromatography-mass spectrometry was employed to elucidate the molecular developmental toxicology of H-BPA using the marine medaka (Oryzias melastigmas) embryo model. Here, we revealed decreased synthesis of nucleosides, amino acids and lipids, and disruptions in the TCA (tricarboxylic acid) cycle, glycolysis and lipid metabolism, thus inhibiting the developmental processes of embryos exposed to H-BPA. Unexpectedly, we observed enhanced neural activity accompanied by lactate accumulation and accelerated heart rates due to an increase in dopamine pathway and a decrease in inhibitory neurotransmitters following H-BPA exposure. Notably, disorders of the neural system, and disruptions in glycolysis, the TCA cycle, nucleoside metabolism, lipid metabolism, glutamate and aspartate metabolism induced by H-BPA exposure were heritable. Furthermore, lactate and dopa were identified as potential biomarkers of the developmental toxicity of H-BPA and related genetic effects. This study has demonstrated that the metabolomics approach is a useful tool for obtaining comprehensive and novel insights into the molecular developmental toxicity of environmental pollutants.

  4. Pyrrolizidine Alkaloid-Protein Adducts: Potential Non-invasive Biomarkers of Pyrrolizidine Alkaloid-Induced Liver Toxicity and Exposure.

    Science.gov (United States)

    Xia, Qingsu; Zhao, Yuewei; Lin, Ge; Beland, Frederick A; Cai, Lining; Fu, Peter P

    2016-08-15

    Pyrrolizidine alkaloids (PAs) are phytochemicals present in hundreds of plant species from different families widely distributed in many geographical regions around the world. PA-containing plants are probably the most common type of poisonous plants affecting livestock, wildlife, and humans. There have been many large-scale human poisonings caused by the consumption of food contaminated with toxic PAs. PAs require metabolic activation to generate pyrrolic metabolites to exert their toxicity. In this study, we developed a novel method to quantify pyrrole-protein adducts present in the blood. This method involves the use of AgNO3 in acidic ethanol to cleave the thiol linkage of pyrrole-protein (DHP-protein) adducts, and the resulting 7,9-di-C2H5O-DHP is quantified by HPLC-ES-MS/MS multiple reaction monitoring analysis in the presence of a known quantity of isotopically labeled 7,9-di-C2D5O-DHP internal standard. Using this method, we determined that diester-type PAs administered to rats produced higher levels of DHP-protein adducts than other types of PAs. The results suggest that DHP-protein adducts can potentially serve as minimally invasive biomarkers of PA exposure.

  5. Use of cell signaling to pre-screen potentially contaminated areas for toxicity-increasing precision and accuracy for answering questions concerning toxicity

    International Nuclear Information System (INIS)

    Abbott, T.; Gee, P.; Farr, S.

    1994-01-01

    Toxicity assessment methods used to determine remediation requirements at environmental sites are costly and not useful for prioritizing tasks based on the degree of risk to the public and environment. The two most common approaches, chemical characterization and aquatic toxicity assays, cannot indicate subcellular mechanisms of toxicity nor the threshold at which cells are stressed. The primary problems lie in the prediction of the types and degree of damage induced by toxins in the environment and how field studies can be designed to validate these predictions for risk assessments. The three main parameters influencing the degree of risk to humans and other animals in the environment are known to be: (1) age, (2) genetic susceptibility, and (3) environmental factors. An individual's genes control the ability to repair or cope with toxins, therefore, monitoring genetic responses is the most direct measure of toxicity thresholds. The purpose of this paper is to show that molecular toxicology assays can increase the accuracy for detection of toxicity and extent of damage

  6. Potential toxicity of sarafloxacin to catalase: Spectroscopic, ITC and molecular docking descriptions

    Science.gov (United States)

    Cao, Zhaozhen; Liu, Rutao; Yang, Bingjun

    2013-11-01

    The interaction between sarafloxacin and catalase (CAT) was studied by fluorescence spectroscopy, UV-visible absorption spectroscopy, circular dichroism (CD) spectroscopy, isothermal titration microcalorimetry (ITC) and molecular docking method. After deducting the inner filter effect, the fluorescence of CAT was quenched regularly by different concentrations of sarafloxacin. The quenching mechanism was studied by lifetime measurement, and it was proved to be mostly due to static quenching. The formation of sarafloxacin-CAT complex alters the micro-environment of amide moieties and tryptophan (Trp) residues, reduces the α-helix content of the enzyme, changes the peripheral substituents on the porphyrin ring of heme and leads to the inhibition of the enzyme activity. Molecular docking study reveals that sarafloxacin is located between two α-helix of CAT near to Trp 182 and Trp 185 residues, which supports the experimental results and helps to have a more clear understanding about the interaction mechanism. The change in the relative position of His 74 to heme induced by the variation of secondary structure is considered to be the major reason for the reduction of CAT activity. Moreover, sarafloxacin binds into a hydrophobic area of CAT mainly through hydrophobic interactions, which is consistent with the ITC analysis.

  7. Calculating reversible potentials for Pt-H and Pt-OH bond formation in basic solutions.

    Science.gov (United States)

    Cai, Yu; Anderson, Alfred B

    2005-04-21

    Two redox reactions on platinum electrodes in base, the formation of underpotential deposited hydrogen, forming a Pt-H bond, and the electro-oxidation of water, forming a Pt-OH bond, were studied by two methods. The first applies a linear relationship between reaction energy in solution and standard reversible potential, an approach recently used in this lab to predict the formation potential of the surface-bonded species. This method depends on the availability of accurate surface adsorption bond strengths from measurement or theory and can be applied in two formats, the empirical model and the linear correlation model. The second method treats the reaction within the so-called double-layer model where reactants and products on the surface are well defined and are experiencing the influence of the electrolyte. When this approach is used, two coordination shells of hydrogen bonded water molecules are found necessary to sufficiently stabilize the hydroxide ion in this model, unlike acid for which past work showed only one shell around the hydronium ion is needed. The calculated reversible potentials for both reactions by the empirical and linear correlation models are in good agreement with the experimental onset potentials observed in cyclic voltammetry measurements for Pt(111) surface electrodes when empirical or accurately calculated H, OH, and H(2)O adsorption energies are used. The double layer models for these reactions also yield satisfactory results, and it is concluded that the models should be useful for studying electron-transfer reactions in base, as has already been done for forming Pt-H and Pt-OH in acid solution.

  8. Detection and Identification of potentially toxic elements in urban soil using in situ spectroscopy

    Science.gov (United States)

    Brook, Anna; Kopel, Daniella; Wittenberg, Lea

    2017-04-01

    Anthropogenic urban soils are the foundation of the urban green infrastructure, the green net quality is as good as each of its patches. In early days of pedology urban soil has been recognized with respect to contamination and the risks for human health but in study performed since the 70s, the importance of urban soil for the urban ecology became increasingly significant. Urban soils are highly disturbed land that was created by the process of urbanization. The dominant agent in the creation of urban soils is human activity which modifies the natural soil through mixing, filling or by contamination of land surfaces so as to create a layer of urban soil which can be more than 50 cm thick. The objective of this study is to determine the extent to which field spectroscopy methods can be used to extend the knowledge of toxic elements in urban soils. The majority of the studies on urban soils concentrate on identifying and mapping of known pollution mostly certain heavy metals, we are focusing on almost non disturbed soils where no direct disturbance occurred but the urban matrix inflicted on it. The elements in those soils where an-knowns features. In this study a top-down analysis is applied for detecting the presence of minerals, organic matter and pollutants in mixed soil samples. Results of the proposed top-down unmixing method suggest that the analysis is made very fast due to the simplified hierarchy which avoids the high-learning curve associated with unmixing algorithms showed that the most abundant components were coarse organic matter 12% followed by concrete dust, plastic crumbs, other man made materials, clay and other minerals. The results of the soils pH, measured electrometrically and the particle size distribution, measured by Laser diffraction, indicate there is no big different between the samples particle size distribution and the pH values of the samples but they are not significantly different from the expected, except for the OM percentage which

  9. Researching the Components of Formation of the Export Potential of Industry on the Micro-and Meso-Levels

    Directory of Open Access Journals (Sweden)

    Pavlenchyk Nataliya F.

    2017-11-01

    Full Text Available The article analyses approaches to formation of the export potential of industry on the micro- and meso-levels. A number of factors influencing the formation of the export potential of industry on the micro- and meso-levels has been considered. It was found that the components of the export potential of industry on the micro- and meso-levels are factors, capabilities (potential, and resources. It has been suggested to perceive the defining resources of formation of the export potential of industrial enterprises as: personnel, production, financial-investment, innovation, marketing, information, organizational, and managerial. It has been found that the main resources of export potential of the industry of region include: production, raw material, natural, financial, investment, social, and innovation. There is a number of opportunities that contribute to the formation of the export potential of the region’s industry, in particular: labor, industrial, financial, raw material, natural, investment, innovation, social, information, and organizational-managerial.

  10. A Cultural Psychological Approach to Analyze Intercultural Learning: Potential and Limits of the Structure Formation Technique

    Directory of Open Access Journals (Sweden)

    Doris Weidemann

    2009-01-01

    Full Text Available Despite the huge interest in sojourner adjustment, there is still a lack of qualitative as well as of longitudinal research that would offer more detailed insights into intercultural learning processes during overseas stays. The present study aims to partly fill that gap by documenting changes in knowledge structures and general living experiences of fifteen German sojourners in Taiwan in a longitudinal, cultural-psychological study. As part of a multimethod design a structure formation technique was used to document subjective theories on giving/losing face and their changes over time. In a second step results from this study are compared to knowledge-structures of seven long-term German residents in Taiwan, and implications for the conceptualization of intercultural learning will be proposed. Finally, results from both studies serve to discuss the potential and limits of structure formation techniques in the field of intercultural communication research. URN: urn:nbn:de:0114-fqs0901435

  11. Contents and risks of potentially toxic elements in wastewater-fed food production systems in Southeast Asia

    DEFF Research Database (Denmark)

    Marcussen, Helle

    Non-treated wastewater is used for irrigation of aquatic food production systems in the peri-urban areas of the major cities in Southeast Asia. Therefore concern is that potentially toxic elements (PTEs) may accumulate in foods produced. Hanoi and Phnom Penh, the capitals of Vietnam and Cambodia......, fish, soil and sediment from wastewater-fed production systems in Hanoi and Phnom Penh. Another aim was to assess the food safety risks of water spinach and fish with respect to PTEs. The third aim was to assess PTE retention capacity of river sediment in Hanoi and the governing retention mechanisms...... the concentration range observed for water spinach grown at agricultural soil not exposed to wastewater in Malaysia. Water spinach grown at sites of high and low wastewater exposure did not show a significantly higher accumulation of PTEs compared to sites without wastewater exposure. In Phnom Penh, water spinach...

  12. Bioaccumulation and biomagnification of potentially toxic elements in the octopus Octopus hubbsorum from the Gulf of California.

    Science.gov (United States)

    Roldán-Wong, Nefertiti Taydé; Kidd, Karen A; Marmolejo-Rodríguez, Ana Judith; Ceballos-Vázquez, Bertha Patricia; Shumilin, Evgueni; Arellano-Martínez, Marcial

    2017-10-26

    The concentrations of 21 potentially toxic elements (PTEs) were determined in the tissues of Octopus hubbsorum from three locations along the Gulf of California coast: two near Santa Rosalia (SR), a site with historical metal contamination, and one in La Paz Bay, a reference site. Concentrations of Cd, Co, Cr, Mn, Ni, Pb, and Zn in octopus from the two SR sites were higher than those from the reference site, reflecting the higher sediment concentrations at the mining-impacted locations. The highest bioaccumulation and biomagnification of elements was found in digestive gland and branchial hearts, while the lowest was observed in the mantle, where the mean concentration of PTEs did not exceed international standards for human consumption of octopus. This study found elevated PTEs in octopus from sites with high metal contamination, and presents the first data on these elements in octopus from the Gulf of California. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Determination of nutrients and potentially toxic elements in Jatropha curcas seeds, oil and biodiesel using inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Maciel, P.B.; Barros de, L.L.S.; Duarte, E.C.M.; Harder, M.N.C.; Abreu, Jr.C.H.; Villanueva, F.C.A.

    2013-01-01

    Biodiesel is a renewable and biodegradable fuel that can be used in diesel engines as a replacement for fossil diesel. A suitable alternative is to produce it from Jatropha curcas, which has high quality oil concentration. Nevertheless, the presence of particular chemical elements above certain limits can affect the product quality, leading to vehicle engine problems and acting as air pollution source. The objective of this work is to develop a method for the simultaneous determination of B, Na, Mg, P, S, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Ba, and Pb in J. curcas seeds, oil and biodiesel using the inductively coupled plasma mass spectrometry (ICP-MS) technique. This material was evaluated because has been successfully employed in India for biodiesel production as well as in other places where there is an incentive to family farming, without affect the food chain. The oil was obtained from seeds via mechanical extraction and the biodiesel was achieved by oil transesterification. After optimization of the microwave digestion method for the different sample types, the samples were analyzed by ICP-MS. The certified reference material NIST SRM 1515 (apple leaves) and the recovery tests were carried out to ensure the accuracy of the proposed method, which made possible the quantification of several nutrients and potentially toxic elements in J. curcas seeds, oil and biodiesel, especially Na, K, Ca, Mg, P and S in biodiesel which are mandatory analyzed by Petroleum, Natural Gas and Biofuel National Agency (ANP). This work highlights the findings of the first study of potentially toxic and nutrient elements in the production chain steps seed-oil-biodiesel from J. curcas. (author)

  14. Simulated climate change conditions unveil the toxic potential of the fungicide pyrimethanil on the midge Chironomus riparius: a multigeneration experiment.

    Science.gov (United States)

    Müller, Ruth; Seeland, Anne; Jagodzinski, Lucas S; Diogo, Joao B; Nowak, Carsten; Oehlmann, Jörg

    2012-01-01

    Although it has been suggested that temperature increase may alter the toxic potential of environmental pollutants, few studies have investigated the potential risk of chemical stressors for wildlife under Global Climate Change (GCC) impact. We applied a bifactorial multigeneration study in order to test if GCC conditions alter the effects of low pesticide concentrations on life history and genetic diversity of the aquatic model organism Chironomus riparius. Experimental populations of the species were chronically exposed to a low concentration of the fungicide pyrimethanil (half of the no-observed-adverse-effect concentration: NOAEC/2) under two dynamic present-day temperature simulations (11.0-22.7°C; 14.0-25.2°C) and one future scenario (16.5-28.1°C). During the 140-day multigeneration study, survival, emergence, reproduction, population growth, and genetic diversity of C. riparius were analyzed. Our results reveal that high temperature and pyrimethanil act synergistically on the midge C. riparius. In simulated present-day scenarios, a NOAEC/2 of pyrimethanil as derived from a life-cycle toxicity test provoked only slight-to-moderate beneficial or adverse effects on C. riparius. In contrast, exposure to a NOAEC/2 concentration of pyrimethanil at a thermal situation likely for a summer under GCC conditions uncovered adverse effects on mortality and population growth rate. In addition, genetic diversity was considerably reduced by pyrimethanil in the future scenario, but only slightly under current climatic conditions. Our multigeneration study under near-natural (climatic) conditions indicates that not only the impact of climate change, but also low concentrations of pesticides may pose a reasonable risk for aquatic insects in future.

  15. Risk assessment of potentially toxic elements in agricultural soils and maize tissues from selected districts in Tanzania

    International Nuclear Information System (INIS)

    Marwa, Ernest M.M.; Meharg, Andrew A.; Rice, Clive M.

    2012-01-01

    A field survey was conducted to investigate the contamination of potentially toxic elements (PTEs) arsenic (As), lead (Pb), chromium (Cr), and nickel (Ni) in Tanzanian agricultural soils and to evaluate their uptake and translocation in maize as proxy to the safety of maize used for human and animal consumption. Soils and maize tissues were sampled from 40 farms in Tanzania and analyzed using inductively coupled plasma-mass spectrometry in the United Kingdom. The results showed high levels of PTEs in both soils and maize tissues above the recommended limits. Nickel levels of up to 34.4 and 56.9 mg kg −1 respectively were found in some maize shoots and grains from several districts. Also, high Pb levels >0.2 mg kg −1 were found in some grains. The grains and shoots with high levels of Ni and Pb are unfit for human and animal consumption. Concentrations of individual elements in maize tissues and soils did not correlate and showed differences in uptake and translocation. However, Ni showed a more efficient transfer from soils to shoots than As, Pb and Cr. Transfer of Cr and Ni from shoots to grains was higher than other elements, implying that whatever amount is assimilated in maize shoots is efficiently mobilized and transferred to grains. Thus, the study recommended to the public to stop consuming and feeding their animals maize with high levels of PTEs for their safety. - Highlights: ► High Ni and Pb levels above the allowable limits were found in maize grains. ► Also maize shoots unfit for animal use were found with high Ni concentrations. ► Mining activities were among the sources of soil contamination. ► The public advised to stop consuming maize with potentially toxic elements.

  16. Assessment of the levels of potentially toxic substances around a transect of anthrosols in Aqaba shoreline, Jordan

    Science.gov (United States)

    Wahsha, Mohammad; Al-Rousan, Saber; Al-Jawasreh, Raid

    2016-04-01

    Soils are the major sink for potentially toxic substances (PTSs) such as heavy metals released into the environment by emissions from the quickly increasing of human impact including industrial mine tailings, disposal of high metal wastes, land misuse, wastewater irrigation, spillage of petrochemicals, and atmospheric deposition. The present study concerns the properties variability and soil biological health status in abandoned salt transportation port site in the Jordanian coast of the Gulf of Aqaba, Red Sea. Seven sites were selected according to different morphological and pedological conditions, anthropogenic impact and the same climate conditions. Successively, all locations were sampled for topsoil in the period between spring-summer 2014. Field observations as well as laboratory analysis including heavy metal concentrations (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn); soil chemo-physical parameters (pH, soil dry mass, carbonate, water holding, organic carbon content, soil particle size distribution), and quality of soil's biological community were determined. The anthropogenic influence related to former port activity on soils of the studied area is evident. Soils in the studied area site are highly contaminated by PTSs, mainly Cu and Zn, by 648, 298.6 mgKg-1respectively. Former activities proved to affect the microarthropods community altering both quantity and quality of soil and the chemo-physical structure of the microhabitats. The evaluation of soil biological quality index (QBS-ar) of the surface horizons from the study area is demonstrated that the area is "sufferings" since it is affected by PTSs contamination resulting in a failure in the ecological success of secondary recolonization after abandonment. However, there is an increasing need for further research in the soils of Aqaba focusing on soil health management , combining QBS-ar index with soil chemo-physical properties. Key words: Potentially Toxic Substances, Heavy Metals, Soil Quality.

  17. Use of simulated evaporation to assess the potential for scale formation during reverse osmosis desalination

    Science.gov (United States)

    Huff, G.F.

    2004-01-01

    The tendency of solutes in input water to precipitate efficiency lowering scale deposits on the membranes of reverse osmosis (RO) desalination systems is an important factor in determining the suitability of input water for desalination. Simulated input water evaporation can be used as a technique to quantitatively assess the potential for scale formation in RO desalination systems. The technique was demonstrated by simulating the increase in solute concentrations required to form calcite, gypsum, and amorphous silica scales at 25??C and 40??C from 23 desalination input waters taken from the literature. Simulation results could be used to quantitatively assess the potential of a given input water to form scale or to compare the potential of a number of input waters to form scale during RO desalination. Simulated evaporation of input waters cannot accurately predict the conditions under which scale will form owing to the effects of potentially stable supersaturated solutions, solution velocity, and residence time inside RO systems. However, the simulated scale-forming potential of proposed input waters could be compared with the simulated scale-forming potentials and actual scale-forming properties of input waters having documented operational histories in RO systems. This may provide a technique to estimate the actual performance and suitability of proposed input waters during RO.

  18. Venom of the Brazilian spider Sicarius ornatus (Araneae, Sicariidae contains active sphingomyelinase D: potential for toxicity after envenomation.

    Directory of Open Access Journals (Sweden)

    Priscila Hess Lopes

    lysis by autologous serum and to induce a significant loss of human keratinocyte cell viability; the female Sicarius ornatus venom was more efficient than male. CONCLUSION: We show here, for the first time, that the Brazilian Sicarius ornatus spider contains active Sphingomyelinase D and is able to cause haemolysis and keratinocyte cell death similar to the South American Loxosceles species, harmful effects that are associated with the presence of active SMases D. These results may suggest that envenomation by this Sicarius spider has the potential to cause similar pathological events as that caused by Loxosceles envenomation. Our results also suggest that, in addition to the interspecific differences, intraspecific variations in the venoms composition may play a role in the toxic potential of the New World Sicarius venoms species.

  19. Venom of the Brazilian spider Sicarius ornatus (Araneae, Sicariidae) contains active sphingomyelinase D: potential for toxicity after envenomation.

    Science.gov (United States)

    Lopes, Priscila Hess; Bertani, Rogério; Gonçalves-de-Andrade, Rute M; Nagahama, Roberto H; van den Berg, Carmen W; Tambourgi, Denise V

    2013-01-01

    human keratinocyte cell viability; the female Sicarius ornatus venom was more efficient than male. We show here, for the first time, that the Brazilian Sicarius ornatus spider contains active Sphingomyelinase D and is able to cause haemolysis and keratinocyte cell death similar to the South American Loxosceles species, harmful effects that are associated with the presence of active SMases D. These results may suggest that envenomation by this Sicarius spider has the potential to cause similar pathological events as that caused by Loxosceles envenomation. Our results also suggest that, in addition to the interspecific differences, intraspecific variations in the venoms composition may play a role in the toxic potential of the New World Sicarius venoms species.

  20. Control of sand flies with attractive toxic sugar baits (ATSB) and potential impact on non-target organisms in Morocco.

    Science.gov (United States)

    Qualls, Whitney A; Müller, Gunter C; Khallaayoune, Khalid; Revay, Edita E; Zhioua, Elyes; Kravchenko, Vasiliy D; Arheart, Kristopher L; Xue, Rui-De; Schlein, Yosef; Hausmann, Axel; Kline, Daniel L; Beier, John C

    2015-02-08

    The persistence and geographical expansion of leishmaniasis is a major public health problem that requires the development of effective integrated vector management strategies for sand fly control. Moreover, these strategies must be economically and environmentally sustainable approaches that can be modified based on the current knowledge of sand fly vector behavior. The efficacy of using attractive toxic sugar baits (ATSB) for sand fly control and the potential impacts of ATSB on non-target organisms in Morocco was investigated. Sand fly field experiments were conducted in an agricultural area along the flood plain of the Ourika River. Six study sites (600 m x 600 m); three with "sugar rich" (with cactus hedges bearing countless ripe fruits) environments and three with "sugar poor" (green vegetation only suitable for plant tissue feeding) environments were selected to evaluate ATSB, containing the toxin, dinotefuran. ATSB applications were made either with bait stations or sprayed on non-flowering vegetation. Control sites were established in both sugar rich and sugar poor environments. Field studies evaluating feeding on vegetation treated with attractive (non-toxic) sugar baits (ASB) by non-target arthropods were conducted at both sites with red stained ASB applied to non-flowering vegetation, flowering vegetation, or on bait stations. At both the sites, a single application of ATSB either applied to vegetation or bait stations significantly reduced densities of both female and male sand flies (Phlebotomus papatasi and P. sergenti) for the five-week trial period. Sand fly populations were reduced by 82.8% and 76.9% at sugar poor sites having ATSB applied to vegetation or presented as a bait station, respectively and by 78.7% and 83.2%, respectively at sugar rich sites. The potential impact of ATSB on non-targets, if applied on green non-flowering vegetation and bait stations, was low for all non-target groups as only 1% and 0.7% were stained with non-toxic bait

  1. The effect of aluminium and sodium impurities on the in vitro toxicity and pro-inflammatory potential of cristobalite

    Science.gov (United States)

    Nattrass, C.; Horwell, Claire J.; Damby, David; Brown, David; Stone, Vicki

    2017-01-01

    BackgroundExposure to crystalline silica (SiO2), in the form of quartz, tridymite or cristobalite, can cause respiratory diseases, such as silicosis. However, the observed toxicity and pathogenicity of crystalline silica is highly variable. This has been attributed to a number of inherent and external factors, including the presence of impurities. In cristobalite-rich dusts, substitutions of aluminium (Al) for silicon (Si) in the cristobalite structure, and impurities occluding the silica surface, have been hypothesised to decrease its toxicity. This hypothesis is tested here through the characterisation and in vitro toxicological study of synthesised cristobalite with incremental amounts of Al and sodium (Na) dopants. MethodsSamples of synthetic cristobalite with incremental amounts of Al and Na impurities, and tridymite, were produced through heating of a silica sol-gel. Samples were characterised for mineralogy, cristobalite purity and abundance, particle size, surface area and surface charge. In vitro assays assessed the ability of the samples to induce cytotoxicity and TNF-α production in J774 macrophages, and haemolysis of red blood cells. ResultsAl-only doped or Al+Na co-doped cristobalite contained between 1 and 4 oxide wt% Al and Na within its structure. Co-doped samples also contained Al- and Na-rich phases, such as albite. Doping reduced cytotoxicity to J774 macrophages and haemolytic capacity compared to non-doped samples. Al-only doping was more effective at decreasing cristobalite reactivity than Al+Na co-doping. The reduction in the reactivity of cristobalite is attributed to both structural impurities and a lower abundance of crystalline silica in doped samples. Neither non-doped nor doped crystalline silica induced production of the pro-inflammatory cytokine TNF-α in J774 macrophages. ConclusionsImpurities can reduce the toxic potential of cristobalite and may help explain the low reactivity of some cristobalite-rich dusts. Whilst further work

  2. Stormwater filtration of toxic heavy metal ions using lignocellulosic materials selection process, fiberization, chemical modification, and mat formation

    Science.gov (United States)

    James S. Han

    1999-01-01

    Lignocellulosic materials were evaluated for their effectiveness in filtering toxic heavy metals from stormwater. Kenaf, alfalfa, juniper, and aspen fibers were used as models to evaluate the effectiveness and limitations of chemical modification and the extent of fiber degradation. Individual and mixed aqueous solutions of nickel, copper, zinc, and cadmium in various...

  3. Organic contaminants in Great Lakes tributaries: Prevalence and potential aquatic toxicity

    Science.gov (United States)

    Baldwin, Austin K.; Corsi, Steven R.; De Cicco, Laura A.; Lenaker, Peter L.; Lutz, Michelle A; Sullivan, Daniel J.; Richards, Kevin D.

    2016-01-01

    Organic compounds used in agriculture, industry, and households make their way into surface waters through runoff, leaking septic-conveyance systems, regulated and unregulated discharges, and combined sewer overflows, among other sources. Concentrations of these organic waste compounds (OWCs) in some Great Lakes tributaries indicate a high potential for adverse impacts on aquatic organisms. During 2010–13, 709 water samples were collected at 57 tributaries, together representing approximately 41% of the total inflow to the lakes. Samples were collected during runoff and low-flow conditions and analyzed for 69 OWCs, including herbicides, insecticides, polycyclic aromatic hydrocarbons, plasticizers, antioxidants, detergent metabolites, fire retardants, non-prescription human drugs, flavors/fragrances, and dyes. Urban-related land cover characteristics were the most important explanatory variables of concentrations of many OWCs. Compared to samples from nonurban watersheds ( 15% urban land cover) had nearly four times the number of detected compounds and four times the total sample concentration, on average. Concentration differences between runoff and low-flow conditions were not observed, but seasonal differences were observed in atrazine, metolachlor, DEET, and HHCB concentrations. Water quality benchmarks for individual OWCs were exceeded at 20 sites, and at 7 sites benchmarks were exceeded by a factor of 10 or more. The compounds with the most frequent water quality benchmark exceedances were the PAHs benzo[a]pyrene, pyrene, fluoranthene, and anthracene, the detergent metabolite 4-nonylphenol, and the herbicide atrazine. Computed estradiol equivalency quotients (EEQs) using only nonsteroidal endocrine-active compounds indicated medium to high risk of estrogenic effects (intersex or vitellogenin induction) at 10 sites. EEQs at 3 sites were comparable to values reported in effluent. This multifaceted study is the largest, most comprehensive assessment of the

  4. Evaluation of the Potential Risk of Drugs to Induce Hepatotoxicity in Human?Relationships between Hepatic Steatosis Observed in Non-Clinical Toxicity Study and Hepatotoxicity in Humans-

    OpenAIRE

    Goda, Keisuke; Kobayashi, Akio; Takahashi, Akemi; Takahashi, Tadakazu; Saito, Kosuke; Maekawa, Keiko; Saito, Yoshiro; Sugai, Shoichiro

    2017-01-01

    In the development of drugs, we sometimes encounter fatty change of the hepatocytes (steatosis) which is not accompanied by degenerative change in the liver in non-clinical toxicity studies. In this study, we investigated the relationships between fatty change of the hepatocytes noted in non-clinical toxicity studies of compound X, a candidate compound in drug development, and mitochondrial dysfunction in order to estimate the potential risk of the compound to induce drug-induced liver injury...

  5. Evaluation of inhibitory effects of Chlorella vulgaris extract on growth, proliferation and biofilm formation by Streptococcus mutans and evaluation of its toxicity

    Directory of Open Access Journals (Sweden)

    2015-11-01

    Full Text Available Background & Objectives: Dental caries is the most important disease caused by some bacteria specially Streptococcus Mutans from Viridans family. The aim of this study is to evaluate the inhibitory effect of Chlorella vulgaris extract on growth, proliferation, and biofilm formation of Streptococcus mutans. Materials & Methods: Microalgae Chlorella vulgaris was extracted via maceration using chloroform, methanol, and acetone (2/1/1 as solvents. The antibacterial activities were evaluated through methods such as disk diffusion, well diffusion, minimal inhibitory concentration (MIC, and minimal bactericidal concentration (MBC; besides, the anti-biofilm formation of Chlorella vulgaris extract was indicated. In the present study, a method utilizing brine shrimp lethality was used to screen the toxicity of Chlorella vulgaris extract, and the mortality of brine shrimps was counted by Magnifying glass in a 24-hour period. Results: The results of disc diffusion and well diffusion of Chlorella vulgaris extract revealed the averages of 16.5 and 23 mm zones of inhibition in Mueller-Hinton agar, respectively. The minimal inhibitory concentration was 25 mg/ml and the minimal bactericidal concentration was 50 mg/ml. The anti-biofilm formation concentration of Chlorella vulgaris extract was 50 mg/ml, and the concentration of brine shrimp toxicity was100 mg/ml. Conclusion: The present study showed that Chlorella vulgaris extract has more significant antimicrobial properties than ampicillin and is able to eliminate Streptococcus mutans biofilm.

  6. Sphygmomanometers and thermometers as potential fomites of Staphylococcus haemolyticus: biofilm formation in the presence of antibiotics

    Directory of Open Access Journals (Sweden)

    Bruna Pinto Ribeiro Sued

    Full Text Available BACKGROUND The association between Staphylococcus haemolyticus and severe nosocomial infections is increasing. However, the extent to which fomites contribute to the dissemination of this pathogen through patients and hospital wards remains unknown. OBJECTIVES In the present study, sphygmomanometers and thermometers were evaluated as potential fomites of oxacillin-resistant S. haemolyticus (ORSH. The influence of oxacillin and vancomycin on biofilm formation by ORSH strains isolated from fomites was also investigated. METHODS The presence of ORSH on swabs taken from fomite surfaces in a Brazilian hospital was assessed using standard microbiological procedures. Antibiotic susceptibility profiles were determined by the disk diffusion method, and clonal distribution was assessed in pulsed-field gel electrophoresis (PFGE assays. Minimum inhibitory concentrations (MICs of oxacillin and vancomycin were evaluated via the broth microdilution method. Polymerase chain reaction (PCR assays were performed to detect the mecA and icaAD genes. ORSH strains grown in media containing 1/4 MIC of vancomycin or oxacillin were investigated for slime production and biofilm formation on glass, polystyrene and polyurethane catheter surfaces. FINDINGS ORSH strains comprising five distinct PFGE types were isolated from sphygmomanometers (n = 5 and a thermometer (n = 1 used in intensive care units and surgical wards. ORSH strains isolated from fomites showed susceptibility to only linezolid and vancomycin and were characterised as multi-drug resistant (MDR. Slime production, biofilm formation and the survival of sessile bacteria differed and were independent of the presence of the icaAD and mecA genes, PFGE type and subtype. Vancomycin and oxacillin did not inhibit biofilm formation by vancomycin-susceptible ORSH strains on abiotic surfaces, including on the catheter surface. Enhanced biofilm formation was observed in some situations. Moreover, a sub-lethal dose of

  7. Potential Sources and Formations of the PM2.5 Pollution in Urban Hangzhou

    Directory of Open Access Journals (Sweden)

    Jian Wu

    2016-07-01

    Full Text Available Continuous measurements of meteorological parameters, gaseous pollutants, particulate matters, and the major chemical species in PM2.5 were conducted in urban Hangzhou from 1 September to 30 November 2013 to study the potential sources and formations of PM2.5 pollution. The average PM2.5 concentration was 69 µg·m−3, ~97% higher than the annual concentration limit in the national ambient air quality standards (NAAQS of China. Relative humidity (RH and wind speed (WS were two important factors responsible for the increase of PM2.5 concentration, with the highest value observed under RH of 70%–90%. PM2.5 was in good correlation with both NO2 and CO, but not with SO2, and the potential source contribution function (PSCF results displayed that local emissions were important potential sources contributing to the elevated PM2.5 and NO2 in Hangzhou. Thus, local vehicle emission was suggested as a major contribution to the PM2.5 pollution. Concentrations of NO2 and CO significantly increased in pollution episodes, while the SO2 concentration even decreased, implying local emission rather than region transport was the major source contributing to the formation of pollution episodes. The sum of SO42−, NO3−, and NH4+ accounted for ~50% of PM2.5 in mass in pollution episodes and the NO3−/EC ratios were significantly elevated, revealing that the formation of secondary inorganic species, particularly NO3−, was an important contributor to the PM2.5 pollution in Hangzhou. This study highlights that controlling local pollution emissions was essential to reduce the PM2.5 pollution in Hangzhou, and the control of vehicle emission in particular should be further promoted in the future.

  8. Identifying Toxic Impacts of Metals Potentially Released during Deep-Sea Mining—A Synthesis of the Challenges to Quantifying Risk

    Directory of Open Access Journals (Sweden)

    Chris Hauton

    2017-11-01

    Full Text Available In January 2017, the International Seabed Authority released a discussion paper on the development of Environmental Regulations for deep-sea mining (DSM within the Area Beyond National Jurisdiction (the “Area”. With the release of this paper, the prospect for commercial mining in the Area within the next decade has become very real. Moreover, within nations' Exclusive Economic Zones, the exploitation of deep-sea mineral ore resources could take place on very much shorter time scales and, indeed, may have already started. However, potentially toxic metal mixtures may be released at sea during different stages of the mining process and in different physical phases (dissolved or particulate. As toxicants, metals can disrupt organism physiology and performance, and therefore may impact whole populations, leading to ecosystem scale effects. A challenge to the prediction of toxicity is that deep-sea ore deposits include complex mixtures of minerals, including potentially toxic metals such as copper, cadmium, zinc, and lead, as well as rare earth elements. Whereas the individual toxicity of some of these dissolved metals has been established in laboratory studies, the complex and variable mineral composition of seabed resources makes the a priori prediction of the toxic risk of DSM extremely challenging. Furthermore, although extensive data quantify the toxicity of metals in solution in shallow-water organisms, these may not be representative of the toxicity in deep-sea organisms, which may differ biochemically and physiologically and which will experience those toxicants under conditions of low temperature, high hydrostatic pressure, and potentially altered pH. In this synthesis, we present a summation of recent advances in our understanding of the potential toxic impacts of metal exposure to deep-sea meio- to megafauna at low temperature and high pressure, and consider the limitation of deriving lethal limits based on the paradigm of exposure to

  9. Investigating the formation and toxicity of nitrogen transformation products of diclofenac and sulfamethoxazole in wastewater treatment plants

    International Nuclear Information System (INIS)

    Osorio, Victoria; Sanchís, Josep; Abad, Jose Luís; Ginebreda, Antoni; Farré, Marinella; Pérez, Sandra; Barceló, Damià

    2016-01-01

    Highlights: • Environmental monitoring of recently discovered TPs of diclofenac in wastewater and surface water. • Quantitative determination of non-detected TPs of sulfamethoxazole in wastewater and impacted surface waters. • Toxicity assessment of diclofenac and its TPs in a panel of standard assays of aquatic organism. • Only nitro-diclofenac proved to be more toxic than the parent compound. - Abstract: Diclofenac (DCF) and sulfamethoxazole (SMX) are highly consumed pharmaceuticals and concentrated in effluents from conventional wastewater treatment plants (WWTPs) since they are not completely eliminated. Under microbial mediated nitrification/denitrification processes occurring in nitrifying activated sludge DCF biotransformed into its nitroso and nitro derivatives (NO-DCF and NO 2 -DCF, respectively). SMX was biotransformed under denitrification conditions in water/sediment batch reactors into its nitro and desamino derivatives (NO 2 -SMX and Des-SMX, respectively). Four transformation products (TPs) from DCF and SMX were analized in wastewaters (WW) and receiving surface waters (SW). Nitrifying/denitrifying-derivatives of DCF and SMX were detected for the first time in WW and SW at one order of magnitude lower than their parent compounds. Relationships observed among levels of NO-DCF, NO 2 -DCF and nitrogen-species tentatively suggested that nitrification/denitrification processes are involved in nitration and nitrosation of DCF during biological WW treatment. Acute toxicity of analytes to Daphnia magna and Vibrio fischeri was assessed individually and in mixtures with other relevant micropollutants. Individual effects showed these compounds as not harmful and not toxic. However, synergism effects observed in mixtures evidenced that contribution of these compounds to overall toxicity of complex environmental samples, should not be dismissed.

  10. Investigating the formation and toxicity of nitrogen transformation products of diclofenac and sulfamethoxazole in wastewater treatment plants

    Energy Technology Data Exchange (ETDEWEB)

    Osorio, Victoria; Sanchís, Josep [Water and Soil Quality Research Group, Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona (Spain); Abad, Jose Luís [RUBAM-IIQAC-CSIC, Jordi Girona 18-26, Barcelona (Spain); Ginebreda, Antoni; Farré, Marinella [Water and Soil Quality Research Group, Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona (Spain); Pérez, Sandra, E-mail: spsqam@idaea.csic.es [Water and Soil Quality Research Group, Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona (Spain); Barceló, Damià [Water and Soil Quality Research Group, Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona (Spain); Catalan Institute for Water Research (ICRA), Scientific and Technological Park of the University of Girona, Emili Grahit 101, Girona (Spain)

    2016-05-15

    Highlights: • Environmental monitoring of recently discovered TPs of diclofenac in wastewater and surface water. • Quantitative determination of non-detected TPs of sulfamethoxazole in wastewater and impacted surface waters. • Toxicity assessment of diclofenac and its TPs in a panel of standard assays of aquatic organism. • Only nitro-diclofenac proved to be more toxic than the parent compound. - Abstract: Diclofenac (DCF) and sulfamethoxazole (SMX) are highly consumed pharmaceuticals and concentrated in effluents from conventional wastewater treatment plants (WWTPs) since they are not completely eliminated. Under microbial mediated nitrification/denitrification processes occurring in nitrifying activated sludge DCF biotransformed into its nitroso and nitro derivatives (NO-DCF and NO{sub 2}-DCF, respectively). SMX was biotransformed under denitrification conditions in water/sediment batch reactors into its nitro and desamino derivatives (NO{sub 2}-SMX and Des-SMX, respectively). Four transformation products (TPs) from DCF and SMX were analized in wastewaters (WW) and receiving surface waters (SW). Nitrifying/denitrifying-derivatives of DCF and SMX were detected for the first time in WW and SW at one order of magnitude lower than their parent compounds. Relationships observed among levels of NO-DCF, NO{sub 2}-DCF and nitrogen-species tentatively suggested that nitrification/denitrification processes are involved in nitration and nitrosation of DCF during biological WW treatment. Acute toxicity of analytes to Daphnia magna and Vibrio fischeri was assessed individually and in mixtures with other relevant micropollutants. Individual effects showed these compounds as not harmful and not toxic. However, synergism effects observed in mixtures evidenced that contribution of these compounds to overall toxicity of complex environmental samples, should not be dismissed.

  11. Evaluating the health risks of potentially toxic elements through wheat consumption in multi-industrial metropolis of Faisalabad, Pakistan.

    Science.gov (United States)

    Abbas, Qumber; Yousaf, Balal; Liu, Guijian; Zia-Ur-Rehman, Muhammad; Ali, Muhammad Ubaid; Munir, Mehr Ahmed Mujtaba; Hussain, Syed Arif

    2017-12-01

    Potentially toxic elements (PTEs) pollution is the fastest growing concern around the entire globe especially in developing countries. Rapid industrialization and urbanization are the dominant sources of anthropogenic soil-food chain contamination with PTEs. The intent of current study was to investigate the interactive levels of Cu, Fe, Mn, Ni, Pb, and Zn in soil and their accumulation in wheat (Triticum aestivum L.) samples collected from 96 sites including industrial, urban, and peri-urban areas of a leading multi-industrialized center (Faisalabad) of Pakistan. According to results obtained from present study, non-carcinogenic (HQ) and life-time carcinogenic risks (CR) of the PTEs to the local inhabitants were estimated following the risk assessment modals proposed by the US-EPA. With respect to estimated HQ for chronic non-carcinogenic risk of Mn, Ni, and Pb, higher potential hazards were observed as compared to Cu, Fe, and Zn. Meanwhile, the carcinogenic risk of Ni marginally exceeded the limit described by US-EPA for adults. Overall, the health risks of PTEs with the consumption of wheat were lower than the limits described by US-EPA except for Ni. However, continuous consumption of this PTEs contaminated food may result the potential buildup of poisonousness and various disorders in humans. Therefore, long-term monitoring and gastrointestinal bio-accessibility studies are requisite for the safety of humans under such conditions.

  12. The potentiation effect makes the difference: Non-toxic concentrations of ZnO nanoparticles enhance Cu nanoparticle toxicity in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Li, Lingxiangyu [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Fernández-Cruz, María Luisa; Connolly, Mona [Departamento de Medio Ambiente, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid 28040 (Spain); Conde, Estefanía; Fernández, Marta [Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), Madrid 28040 (Spain); Schuster, Michael [Department of Chemistry, Technische Universität München, Garching 85747 (Germany); Navas, José María, E-mail: jmnavas@inia.es [Departamento de Medio Ambiente, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid 28040 (Spain)

    2015-02-01

    Here we examined whether the addition of a non-toxic concentration (6.25 μg/mL) of zinc oxide nanoparticles (ZnONPs: 19, 35 and 57 nm, respectively) modulates the cytotoxicity of copper nanoparticles (CuNPs, 63 nm in size) in the human hepatoma cell line HepG2. The cytotoxic effect of CuNPs on HepG2 cells was markedly enhanced by the ZnONPs, the largest ZnONPs causing the highest increase in toxicity. However, CuNPs cytotoxicity was not affected by co-incubation with medium containing only zinc ions, indicating the increase in toxicity might be attributed to the particle form of ZnONPs. Transmission electron microscopy (TEM) revealed the presence of CuNPs and ZnONPs inside the cells co-exposed to both types of NP and outflow of cytoplasm through the damaged cell membrane. Inductively coupled plasma mass spectrometry (ICP-MS) determined an increase in the concentration of zinc and a decrease in that of copper in co-exposed cells. On the basis of these results, we propose that accumulation of large numbers of ZnONPs in the cells alters cellular membranes and the cytotoxicity of CuNPs is increased. - Highlights: • ZnONPs at non-toxic concentrations increased the toxicity of CuNPs in vitro. • ZnONPs of larger size provoked a stronger synergistic effect with CuNPs. • The synergistic effect was attributed to the particle fraction of ZnONPs.

  13. Hepatocurative potential of sesquiterpene lactones of Taraxacum officinale on carbon tetrachloride induced liver toxicity in mice.

    Science.gov (United States)

    Mahesh, A; Jeyachandran, R; Cindrella, L; Thangadurai, D; Veerapur, V P; Muralidhara Rao, D

    2010-06-01

    The hepatocurative potential of ethanolic extract (ETO) and sesquiterpene lactones enriched fraction (SL) of Taraxacum officinale roots was evaluated against carbon tetrachloride (CCl 4 ) induced hepatotoxicity in mice. The diagnostic markers such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bilirubin contents were significantly elevated, whereas significant reduction in the level of reduced glutathione (GSH) and enhanced hepatic lipid peroxidation, liver weight and liver protein were observed in CCl 4 induced hepatotoxicity in mice. Post-treatment with ETO and SL significantly protected the hepatotoxicity as evident from the lower levels of hepatic enzyme markers, such as serum transaminase (ALT, AST), ALP and total bilirubin. Further, significant reduction in the liver weight and liver protein in drug-treated hepatotoxic mice and also reduced oxidative stress by increasing reduced glutathione content and decreasing lipid peroxidation level has been noticed. The histopathological evaluation of the liver also revealed that ETO and SL reduced the incidence of liver lesions induced by CCl 4 . The results indicate that sesquiterpene lactones have a protective effect against acute hepatotoxicity induced by the administration of CCl 4 in mice. Furthermore, observed activity of SL may be due to the synergistic action of two sesquiterpene lactones identified from enriched ethyl acetate fraction by HPLC method.

  14. Potential toxicity of sulfanilamide antibiotic: Binding of sulfamethazine to human serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jiabin [State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092 (China); Zhou, Xuefei [Key Laboratory of Yangtze River Water Environment for Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092 (China); Zhang, Yalei, E-mail: zhangyalei2003@163.com [State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092 (China); Gao, Haiping [Key Laboratory of Yangtze River Water Environment for Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092 (China)

    2012-08-15

    Antibiotics are widely used in daily life but their abuse has posed a potential threat to human health. The interaction between human serum albumin (HSA) and sulfamethazine (SMZ) was investigated by capillary electrophoresis, fluorescence spectrometry, and circular dichroism. The binding constant and site were determined to be 1.09 Multiplication-Sign 10{sup 4} M{sup -1} and 1.14 at 309.5 K. The thermodynamic determination indicated that the interaction was driven by enthalpy change, where the electrostatic interaction and hydrogen bond were the dominant binding force. The binding distance between SMZ and tryptophan residue of HSA was obtained to be 3.07 nm according to Foerster non-radioactive energy transfer theory. The site marker competition revealed that SMZ bound into subdomain IIA of HSA. The binding of SMZ induced the unfolding of the polypeptides of HSA and transferred the secondary conformation of HSA. The equilibrium dialysis showed that only 0.13 mM SMZ decreased vitamin B{sub 2} by 38% transported on the HSA. This work provides a new quantitative evaluation method for antibiotics to cause the protein damage. -- Highlights: Black-Right-Pointing-Pointer Various techniques characterized the interactions between SMZ and HSA. Black-Right-Pointing-Pointer The electrostatic interaction and hydrogen bond dominated in the interaction. Black-Right-Pointing-Pointer SMZ induced the conformation change of HSA. Black-Right-Pointing-Pointer SMZ affected the transportation function of HSA.

  15. Identification of a potential toxic hot spot associated with AVS spatial and seasonal variation.

    Science.gov (United States)

    Campana, O; Rodríguez, A; Blasco, J

    2009-04-01

    In risk assessment of aquatic sediments, much attention is paid to the difference between acid-volatile sulfide (AVS) and simultaneously extracted metals (SEMs) as indicators of metal availability. Ten representative sampling sites were selected along the estuary of the Guadalete River. Surficial sediments were sampled in winter and summer to better understand SEM and AVS spatial and seasonal distributions and to establish priority risk areas. Total SEM concentration (SigmaSEM) ranged from 0.3 to 4.7 micromol g(-1). It was not significantly different between seasons, however, it showed a significant difference between sampling stations. AVS concentrations were much more variable, showing significant spatial and temporal variations. The values ranged from 0.8 to 22.4 micromol g(-1). The SEM/AVS ratio was found to be <1 at all except one station located near the mouth of the estuary. The results provided information on a potential pollution source near the mouth of the estuary, probably associated with vessel-related activities carried out in a local harbor area located near the station.

  16. Application of dental nanomaterials: potential toxicity to the central nervous system.

    Science.gov (United States)

    Feng, Xiaoli; Chen, Aijie; Zhang, Yanli; Wang, Jianfeng; Shao, Longquan; Wei, Limin

    2015-01-01

    Nanomaterials are defined as materials with one or more external dimensions with a size of 1-100 nm. Such materials possess typical nanostructure-dependent properties (eg, chemical, biological, optical, mechanical, and magnetic), which may differ greatly from the properties of their bulk counterparts. In recent years, nanomaterials have been widely used in the production of dental materials, particularly in light polymerization composite resins and bonding systems, coating materials for dental implants, bioceramics, endodontic sealers, and mouthwashes. However, the dental applications of nanomaterials yield not only a significant improvement in clinical treatments but also growing concerns regarding their biosecurity. The brain is well protected by the blood-brain barrier (BBB), which separates the blood from the cerebral parenchyma. However, in recent years, many studies have found that nanoparticles (NPs), including nanocarriers, can transport through the BBB and locate in the central nervous system (CNS). Because the CNS may be a potential target organ of the nanomaterials, it is essential to determine the neurotoxic effects of NPs. In this review, possible dental nanomaterials and their pathways into the CNS are discussed, as well as related neurotoxicity effects underlying the in vitro and in vivo studies. Finally, we analyze the limitations of the current testing methods on the toxicological effects of nanomaterials. This review contributes to a better understanding of the nano-related risks to the CNS as well as the further development of safety assessment systems.

  17. Educational and Professional Potential of Personnel: Essence and Role in Formation of Investment Attractiveness of a Company

    OpenAIRE

    Skrynkovskyy Ruslan M.

    2013-01-01

    The article reveals the essence of educational and professional potential of personnel and investment attractiveness of a company. It provides a model of formation of investment attractiveness of a company. It establishes the role of educational and professional potential of personnel in formation of investment attractiveness of a company. It provides a mathematical description of influence of educational and professional potential of personnel on investment attractiveness of a company.В стат...

  18. Inherent organic compounds in biochar--Their content, composition and potential toxic effects.

    Science.gov (United States)

    Buss, Wolfram; Mašek, Ondřej; Graham, Margaret; Wüst, Dominik

    2015-06-01

    Pyrolysis liquids consist of thermal degradation products of biomass in various stages of its decomposition. Therefore, if biochar gets affected by re-condensed pyrolysis liquids it is likely to contain a huge variety of organic compounds. In this study the chemical composition of such compounds associated with two contaminated, high-volatile organic compound (VOC) biochars were investigated and compared with those for a low-VOC biochar. The water-soluble organic compounds with the highest concentrations in the two high-VOC biochars were acetic, formic, butyric and propionic acids; methanol, phenol, o-, m- and p-cresol, and 2,4-dimethylphenol, all with concentrations over 100 μg g(-1). The concentrations of 16 US EPA PAHs determined by 36 h toluene extractions were 6.09 μg g(-1) for the low-VOC biochar. For high-VOC biochar the total concentrations were 53.42 μg g(-1) and 27.89 μg g(-1), while concentrations of water-soluble PAHs ranged from 1.5 to 2 μg g(-1). Despite the concentrations of PAHs exceeding biochar guideline values, it was concluded that, for these particular biochars, the biggest concern for application to soil would be the co-occurrence of VOCs such as low molecular weight (LMW) organic acids and phenols, as these can be highly mobile and have a high potential to cause phytotoxic effects. Therefore, based on results of this study we strongly suggest for VOCs to be included among criteria for assessment of biochar quality. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. [Effect of ferulic acid on cholesterol efflux in macrophage foam cell formation and potential mechanism].

    Science.gov (United States)

    Chen, Fu-xin; Wang, Lian-kai

    2015-02-01

    The formation of macrophage-derived foam cells is a typical feature of atherosclerosis (AS). Reverse cholesterol efflux (RCT) is one of important factors for the formation of macrophage foam cells. In this study, macrophage form cells were induced by oxidized low density lipoprotein (ox-LDL) and then treated with different concentrations of ferulic acid, so as to observe the effect of ferulic acid on the intracellular lipid metabolism in the ox-LDL-induced macrophage foam cell formation, the cholesterol efflux and the mRNA expression and protein levels of ATP binding cassette transporter A1 (ABCA1) and ATP binding cassette transporter G1 (ABCG1) that mediate cholesterol efflux, and discuss the potential mechanism of ferulic acid in resisting AS. According to the findings, compared with the control group, the ox-LDL-treated group showed significant increase in intracellular lipid content, especially for the cholesterol content; whereas the intracellular lipid accumulation markedly decreased, after the treatment with ferulic acid. The data also demonstrated that the mRNA and protein expressions of ABCA1 and ABCG1 significantly increased after macrophage foam cells were treated with different concentrations of ferulic acid. In summary, ferulic acid may show the anti-atherosclerosis effect by increasing the surface ABCA1 and ABCG1 expressions of macrophage form cells and promoting cholesterol efflux.

  20. Biological Communities in Desert Varnish and Potential Implications for Varnish Formation Mechanisms

    Science.gov (United States)

    Lang-Yona, Naama; Maier, Stefanie; Macholdt, Dorothea; Rodriguez-Caballero, Emilio; Müller-Germann, Isabell; Yordanova, Petya; Jochum, Klaus-Peter; Andreae, Meinrat O.; Pöschl, Ulrich; Weber, Bettina; Fröhlich-Nowoisky, Janine

    2017-04-01

    Desert varnishes are thin, orange to black coatings found on rocks in arid and semi-arid environments on Earth. The formation mechanisms of rock varnish are still under debate and the involvement of microorganisms in this process remains unclear. In this work we aimed to identify the microbial community occurring in rock varnish to potentially gain insights into the varnish formation mechanism. For this purpose, rocks coated with desert varnish were collected from the Anza-Borrego Desert, California, USA, as well as soils from underneath the rocks. DNA from both varnish coatings and soil samples was extracted and subsequently used for metagenomic analysis, as well as for q-PCR analyses for specific species quantification. The element composition of the varnish coatings was analyzed and compared to the soil samples. Rock varnish shows similar depleted elements, compared to soil, but Mn and Pb are 50-60 times enriched compared to the soil samples, and about 100 times enriched compared to the upper continental crust. Our genomic analyses suggest unique populations and different protein functional groups occurring in the varnish compared to soil samples. We discuss these differences and try to shed light on the mechanism of Mn oxyhydroxide production in desert varnish formation.

  1. Anti-atherosclerotic potential of gossypetin via inhibiting LDL oxidation and foam cell formation

    International Nuclear Information System (INIS)

    Chen, Jing-Hsien; Tsai, Chia-Wen; Wang, Chi-Ping; Lin, Hui-Hsuan

    2013-01-01

    Gossypetin, a flavone originally isolated from Hibiscus species, has been shown to possess antioxidant, antimicrobial, and antimutagenic activities. Here, we investigated the mechanism(s) underlying the anti-atherosclerotic potential of gossypetin. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging activity assay showed that the addition of > 50 μM of gossypetin could scavenge over 50% of DPPH radicals. The inhibitory effects of gossypetin on the lipid and protein oxidation of LDL were defined by thiobarbituric acid reactive substance (TBARS) assay, the relative electrophoretic mobility (REM) of oxidized LDL (ox-LDL), and fragmentation of apoB in the Cu 2+ -induced oxidation of LDL. Gossypetin showed potential in reducing ox-LDL-induced foam cell formation and intracellular lipid accumulation, and uptake ability of macrophages under non-cytotoxic concentrations. Molecular data showed that these influences of gossypetin might be mediated via peroxisome proliferator-activated receptor α (PPARα)/liver-X receptor α (LXRα)/ATP-binding cassette transporter A1 (ABCA1) and PPARγ/scavenger receptor CD36 pathways, as demonstrated by the transfection of PPARα siRNA or PPARγ expression vector. Our data implied that gossypetin regulated the PPAR signals, which in turn led to stimulation of cholesterol removal from macrophages and delay atherosclerosis. These results suggested that gossypetin potentially could be developed as an anti-atherosclerotic agent. - Highlights: • The anti-atherosclerotic effect of gossypetin in vitro was examined. • Gossypetin inhibited LDL oxidation. • Gossypetin showed potential in reducing on the formation of foam cells. • Gossypetin functions against ox-LDL through PPARa activation and PPARγ depression

  2. Anti-atherosclerotic potential of gossypetin via inhibiting LDL oxidation and foam cell formation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jing-Hsien [School of Nutrition, Chung Shan Medical University, Taichung, Taiwan (China); Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Tsai, Chia-Wen [Department of Nutrition, China Medical University, Taichung, Taiwan (China); Wang, Chi-Ping [Department of Clinical Laboratory, Chung Shan Medical University Hospital, Taichung, Taiwan (China); Lin, Hui-Hsuan, E-mail: linhh@csmu.edu.tw [Department of Medical Research, Chung Shan Medical University Hospital, Taichung, Taiwan (China); School of Medical Laboratory and Biotechnology, Chung Shan Medical University, Taichung, Taiwan (China)

    2013-10-15

    Gossypetin, a flavone originally isolated from Hibiscus species, has been shown to possess antioxidant, antimicrobial, and antimutagenic activities. Here, we investigated the mechanism(s) underlying the anti-atherosclerotic potential of gossypetin. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging activity assay showed that the addition of > 50 μM of gossypetin could scavenge over 50% of DPPH radicals. The inhibitory effects of gossypetin on the lipid and protein oxidation of LDL were defined by thiobarbituric acid reactive substance (TBARS) assay, the relative electrophoretic mobility (REM) of oxidized LDL (ox-LDL), and fragmentation of apoB in the Cu{sup 2+}-induced oxidation of LDL. Gossypetin showed potential in reducing ox-LDL-induced foam cell formation and intracellular lipid accumulation, and uptake ability of macrophages under non-cytotoxic concentrations. Molecular data showed that these influences of gossypetin might be mediated via peroxisome proliferator-activated receptor α (PPARα)/liver-X receptor α (LXRα)/ATP-binding cassette transporter A1 (ABCA1) and PPARγ/scavenger receptor CD36 pathways, as demonstrated by the transfection of PPARα siRNA or PPARγ expression vector. Our data implied that gossypetin regulated the PPAR signals, which in turn led to stimulation of cholesterol removal from macrophages and delay atherosclerosis. These results suggested that gossypetin potentially could be developed as an anti-atherosclerotic agent. - Highlights: • The anti-atherosclerotic effect of gossypetin in vitro was examined. • Gossypetin inhibited LDL oxidation. • Gossypetin showed potential in reducing on the formation of foam cells. • Gossypetin functions against ox-LDL through PPARa activation and PPARγ depression.

  3. Emission characteristics of VOCs emitted from consumer and commercial products and their ozone formation potential.

    Science.gov (United States)

    Dinh, Trieu-Vuong; Kim, Su-Yeon; Son, Youn-Suk; Choi, In-Young; Park, Seong-Ryong; Sunwoo, Young; Kim, Jo-Chun

    2015-06-01

    The characteristics of volatile organic compounds (VOCs) emitted from several consumer and commercial products (body wash, dishwashing detergent, air freshener, windshield washer fluid, lubricant, hair spray, and insecticide) were studied and compared. The spray products were found to emit the highest amount of VOCs (~96 wt%). In contrast, the body wash products showed the lowest VOC contents (~1.6 wt%). In the spray products, 21.6-96.4 % of the VOCs were propane, iso-butane, and n-butane, which are the components of liquefied petroleum gas. Monoterpene (C10H16) was the dominant component of the VOCs in the non-spray products (e.g., body wash, 53-88 %). In particular, methanol was present with the highest amount of VOCs in windshield washer fluid products. In terms of the number of carbon, the windshield washer fluids, lubricants, insecticides, and hair sprays comprised >95 % of the VOCs in the range C2-C5. The VOCs in the range C6-C10 were predominantly found in the body wash products. The dishwashing detergents and air fresheners contained diverse VOCs from C2 to C11. Besides comprising hazardous VOCs, VOCs from consumer products were also ozone precursors. The ozone formation potential of the consumer and commercial spray products was estimated to be higher than those of liquid and gel materials. In particular, the hair sprays showed the highest ozone formation potential.

  4. Mechanical strain promotes osteoblast ECM formation and improves its osteoinductive potential

    Directory of Open Access Journals (Sweden)

    Guo Yong

    2012-10-01

    Full Text Available Abstract Background The extracellular matrix (ECM provides a supportive microenvironment for cells, which is suitable as a tissue engineering scaffold. Mechanical stimulus plays a significant role in the fate of osteoblast, suggesting that it regulates ECM formation. Therefore, we investigated the influence of mechanical stimulus on ECM formation and bioactivity. Methods Mouse osteoblastic MC3T3-E1 cells were cultured in cell culture dishes and stimulated with mechanical tensile strain. After removing the cells, the ECMs coated on dishes were prepared. The ECM protein and calcium were assayed and MC3T3-E1 cells were re-seeded on the ECM-coated dishes to assess osteoinductive potential of the ECM. Results The cyclic tensile strain increased collagen, bone morphogenetic protein 2 (BMP-2, BMP-4, and calcium levels in the ECM. Compared with the ECM produced by unstrained osteoblasts, those of mechanically stimulated osteoblasts promoted alkaline phosphatase activity, elevated BMP-2 and osteopontin levels and mRNA levels of runt-related transcriptional factor 2 (Runx2 and osteocalcin (OCN, and increased secreted calcium of the re-seeded MC3T3-E1 cells. Conclusion Mechanical strain promoted ECM production of osteoblasts in vitro, increased BMP-2/4 levels, and improved osteoinductive potential of the ECM. This study provided a novel method to enhance bioactivity of bone ECM in vitro via mechanical strain to osteoblasts.

  5. Crack initiation and potential hot-spot formation around a cylindrical defect under dynamic compression

    Science.gov (United States)

    Ma, Xiao; Li, Xinguo; Zheng, Xianxu; Li, Kewu; Hu, Qiushi; Li, Jianling

    2017-11-01

    In recent decades, the hot-spot theory of condensed-phase explosives has been a compelling focus of scientific investigation attracting many researchers. The defect in the polymeric binder of the polymer-bonded explosive is called the intergranular defect. In this study, the real polymeric binder was substituted by poly(methyl methacrylate) (PMMA) as it is transparent and has similar thermodynamic properties to some binders. A set of modified split Hopkinson pressure bars equipped with a time-resolved shadowgraph was used to study the process of crack initiation and potential hot-spot formation around a cylindrical defect in PMMA. The new and significant phenomenon that the opening-mode crack emerged earlier than the shearing-mode crack from the cylindrical defect has been published for the first time in this paper. Furthermore, a two-dimensional numerical simulation was performed to show the evolution of both the stress field and the temperature field. The simulation results were in good agreement with the experiment. Finally, the law of potential hot-spot formation is discussed in detail.

  6. EFFECTIVE USE OF RESOURCE POTENTIAL AS BASIS OF FORMATION OF SELF-SUFFICIENCY OF RURAL COMMUNITIES

    Directory of Open Access Journals (Sweden)

    Н. В. Морозюк

    2014-01-01

    Full Text Available Purpose is development of practical offers of increase of efficiency of use of resource potential of rural territories for formation of self-sufficiency of territorial communities.Methodology is system approach of scientific knowledge. In thе research were used such methods аs: monographic, generalizations, comparisons, abstract and logical modeling and others.Results. The natural and resource potential of rural ter-ritories of Ukraine and Russia is considered in the article. The conclusion is drawn that at its uniqueness rural communities remain subsidized and people below the poverty line. Result of research is offered development of such directions of use of natural resources: for satisfaction of needs of a community; processing and further realization to locals or outside a community; export out of community limits. The advantages from a position of formation of self-sufficiency of rural communities are considered for each of directions, offers on improvement of the organizational and economic mechanism of their realization are developed.Practical implications. Conclusions of the research can be used in practical activities of public authorities and local government.Purchase on Elibrary.ru > Buy now

  7. Gene expression profiling to identify the toxicities and potentially relevant human disease outcomes associated with environmental heavy metal exposure.

    Science.gov (United States)

    Korashy, Hesham M; Attafi, Ibraheem M; Famulski, Konrad S; Bakheet, Saleh A; Hafez, Mohammed M; Alsaad, Abdulaziz M S; Al-Ghadeer, Abdul Rahman M

    2017-02-01

    Heavy metals are the most commonly encountered toxic substances that increase susceptibility to various diseases after prolonged exposure. We have previously shown that healthy volunteers living near a mining area had significant contamination with heavy metals associated with significant changes in the expression of some detoxifying genes, xenobiotic metabolizing enzymes, and DNA repair genes. However, alterations of most of the molecular target genes associated with diseases are still unknown. Thus, the aims of this study were to (a) evaluate the gene expression profile and (b) identify the toxicities and potentially relevant human disease outcomes associated with long-term human exposure to environmental heavy metals in mining area using microarray analysis. For this purpose, 40 healthy male volunteers who were residents of a heavy metal-polluted area (Mahd Al-Dhahab city, Saudi Arabia) and 20 healthy male volunteers who were residents of a non-heavy metal-polluted area were included in the study. Total RNA was isolated from whole blood using PAXgene Blood RNA tubes and then reversed transcribed and hybridized to the gene array using the Affymetrix U219 GeneChip. Microarray analysis showed about 2129 genes were identified and differentially altered, among which a shared set of 425 genes was differentially expressed in the heavy metal-exposed groups. Ingenuity pathway analysis revealed that the most altered gene-regulated diseases in heavy metal-exposed groups included hematological and developmental disorders and mostly renal and urological diseases. Quantitative real-time polymerase chain reaction closely matched the microarray data for some genes tested. Importantly, changes in gene-related diseases were attributed to alterations in the genes encoded for protein synthesis. Renal and urological diseases were the diseases that were most frequently associated with the heavy metal-exposed group. Therefore, there is a need for further studies to validate these

  8. The relationship between physicochemical characterization and the potential toxicity of fine particulates (PM 2.5) in Shanghai atmosphere

    Science.gov (United States)

    Senlin, Lu; Zhenkun, Yao; Xiaohui, Chen; Minghong, Wu; Guoying, Sheng; Jiamo, Fu; Paul, Daly

    Fine particulate matter with aerodynamic diameter less than 2.5 μm (PM 2.5) was collected at urban and suburban sites in Shanghai from April 2005 to March 2006. Average mass concentrations of PM 2.5 ranged from 43.5 to 149 μg m -3 in the urban area and 21.7 to 159 μg m -3 in suburban area. The mass levels of PM 2.5 sampled at urban and suburban sites showed seasonal variation with much higher values in winter and spring, lower values in summer, and the lowest in autumn. The results of environmental scanning electron microscopy (ESEM) showed that Shanghai PM 2.5 was consisted of soot aggregates, coal fly ashes, minerals, bio-particles and unidentified particles. Inductively coupled plasma atomic mission spectrum (ICP-AES) results showed total elements in Shanghai PM 2.5 increased gradually from summer to winter and remained at a relatively high level in spring. There was a significant difference in the mass of elements in PM 2.5 collected in urban and in suburban atmosphere. Enrichment factor (EF) analysis results demonstrated that K, Na, Ca, Mg, Al, Fe, Ba and Sr originated from natural sources, while As, Cu, Zn, Pb, Cd, Mn, Ni and Se were emitted from anthropogenic sources. The plasmid DNA assay showed that potential toxicity of Shanghai PM 2.5 collected at urban and suburban sampling sites, and in different seasons, varied greatly. Toxicity of the Shanghai urban winter PM 2.5 sample was much stronger compared to any of the other samples. Heavy metals in Shanghai PM 2.5, including Cu, Zn, Pb, Cd, Cr, Mn, and Ni, might have synergic-effects on plasmid DNA damage.

  9. Khadum Formation of Pre-Caucasus region as potential source of oil shales: geology and geochemistry

    Directory of Open Access Journals (Sweden)

    N.Sh. Yandarbiev1

    2017-05-01

    Full Text Available One of the main modern aim for oil industry is the development of hydrocarbon extraction technologies from «oil shale». In Russia there are kerogen-saturated carbonate-clayey-siliceous deposits of the Bazhenov Formation, carbonate rocks of the Volga-Ural and Timan-Pechora oil and gas bearing basins and clayey Maikop series of Pre-Caucasus region. The Khadum Formation is lower part of the Maikop series represented by carbonate-clay and clayey deposits. On the basis of long-term field and laboratory investigation conducted by specialists of the Oil and Gas Department from Geological Faculty of the Lomonosov Moscow State University. a comprehensive study of the lithological composition, structure, geochemical, hydrogeological and hydrodynamic characteristics of the Paleogene section and monitoring of the drilled wells, the prospects of the oil and gas potential of the Khadum deposits of the Oligocene in the Eastern Pre-Caucasus oil and gas bearing basin were estimated. 11 gas and 19 oil deposits are discovered within the Khadum deposits, and they are confined to the sand layers and lenses, but most of the Khadum section belongs to «unconventional» sources of hydrocarbons. Based on the integrated approach, a map of oil and gas potential prospects for the Khadum deposits was constructed. Highly prospective territories for drilling for oil, areas with small and medium perspectives, and gas prospecting areas have been singled out. Recommendations are given for drilling and technology for the development of the Pre-Caucasus oil shales, based on the world experience in the development of such formations.

  10. [Studies of ozone formation potentials for benzene and ethylbenzene using a smog chamber and model simulation].

    Science.gov (United States)

    Jia, Long; Xu, Yong-Fu

    2014-02-01

    Ozone formation potentials from irradiations of benzene-NO(x) and ethylbenzene-NO(x) systems under the conditions of different VOC/NO(x) ratios and RH were investigated using a characterized chamber and model simulation. The repeatability of the smog chamber experiment shows that for two sets of ethylbenzene-NO(x) irradiations with similar initial concentrations and reaction conditions, such as temperature, relative humidity and relative light intensity, the largest difference in O3 between two experiments is only 4% during the whole experimental run. On the basis of smog chamber experiments, ozone formation of photo-oxidation of benzene and ethylbenzene was simulated in terms of the master chemical mechanism (MCM). The peak ozone values for benzene and ethylbenzene simulated by MCM are higher than the chamber data, and the difference between the MCM-simulated results and chamber data increases with increasing RH. Under the conditions of sunlight irradiations, with benzene and ethylbenzene concentrations being in the range of (10-50) x 10(-9) and NO(x) concentrations in the range of (10-100) x 10(-9), the 6 h ozone contributions of benzene and ethylbenzene were obtained to be (3.1-33) x 10(-9) and (2.6-122) x 10(-9), whereas the peak O3 contributions of benzene and ethylbenzene were (3.5-54) x 10(-9) and (3.8-164) x 10(-9), respectively. The MCM-simulated maximum incremental reactivity (MIR) values for benzene and ethylbenzene were 0.25/C and 0.97/C (per carbon), respectively. The maximum ozone reactivity (MOR) values for these two species were obtained to be 0.73/C and 1.03/C, respectively. The MOR value of benzene from MCM is much higher than that obtained by carter from SAPRC, indicating that SAPRC may underestimate the ozone formation potential of benzene.

  11. Evaluating the potential health risk of toxic trace elements in vegetables: Accounting for variations in soil factors.

    Science.gov (United States)

    Yang, Yang; Chen, Weiping; Wang, Meie; Li, Yanling; Peng, Chi

    2017-04-15

    Vegetable crop consumption is one of the main sources of dietary exposure to toxic trace elements (TEs). A paired survey of soil and vegetable samples was conducted in 589 agricultural sites in the Youxian prefecture, southern China, to investigate the effect of soil factors on the accumulation of arsenic, cadmium, mercury, and lead in different vegetables. A site-specific model was developed to estimate the health risk from vegetable consumption. The TE concentration varied in different plant species, and rape can be cultivated in contaminated areas for its potential use in restricting the transfer of TE from soil to edible plant parts. The accumulation of TEs in vegetables was governed by multiple factors, mainly element interaction, metal availability (extractable CaCl 2 fraction), and soil pH. Soil Zn may promote Cd accumulation in vegetables when soil Cd/Zn ratio>0.02. Cadmium is a major hazardous component. About 80.8% of the adult populations consuming locally produced vegetables had a daily Cd intake risk above the safe standard. Among investigated vegetables, radish is potentially hazardous for populations because of its high consumption rate and high Cd content but low Zn accumulation. The consumption of radish cultivated in highly acidic soil (4TE concentrations and soil factors suggests that a site-specific risk assessment is needed for better and safer vegetable production. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Evaluation of the toxic potential of coffee wastewater on seeds, roots and meristematic cells of Lactuca sativa L.

    Science.gov (United States)

    Aguiar, Luara Louzada; Andrade-Vieira, Larissa Fonseca; de Oliveira David, José Augusto

    2016-11-01

    Coffee wastewater (CWW) is an effluent produced through wet processing of coffee containing high concentration of organic matter, nutrients, salts and also agrochemicals. It is released directly into the argillaceous soil or into decantation tanks for later disposal into soils, by fertigation, subsurface infiltration or superficial draining. However, this practice is not followed by the monitoring the toxicity potential of this effluent. In this sense, the present work aimed to evaluate the phytotoxic, cytogenotoxic and mutagenic potential of CWW on seed germination, root elongation and cell cycle alterations in the plant model Lactuca sativa L. The effluent (CWW) collected was diluted in distilled water into six concentrations solutions (1.25%, 1.66%, 2.5%, 5.0%, 10%, 20%). A solution of raw CWW (100%) was also applied. Distilled water was used as negative control), and the DNA alkylating agent, metilmetano sulfonate (4×10(-4)M) as positive control. Physico-chemical parameters of the CWW was accessed and it was found that the effluent contained total phenols and inorganic matter in amounts within the limits established by the National Environment Council (CONAMA). Nevertheless, the biologicals assays performed demonstrated the phytotoxicity and cytogenotoxicty of CWW. Seed germination was totally inhibited after exposure of raw CWW. In addition, a decrease in seed germination speed as well as in root growth dose-dependently manner was noticed. Moreover, nuclear and chromosomal alterations were observed in the cell cycle, mostly arising from aneugenic action. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Chronic toxicity of arsenic during Rhinella arenarum embryonic and larval development: Potential biomarkers of oxidative stress and antioxidant response.

    Science.gov (United States)

    Mardirosian, Mariana Noelia; Lascano, Cecilia Inés; Bongiovanni, Guillermina Azucena; Venturino, Andrés

    2017-06-01

    The Argentinean autochthonous toad Rhinella arenarum was selected to study the chronic toxicity of arsenic (As) and the biochemical responses elicited by exposure to As in water during embryonic and larval development. Significant decreases in the total reactive antioxidant potential and in catalase activity were observed in individuals exposed chronically to sublethal concentrations of As, which is indicative of an oxidative stress situation. However, an antioxidant response was elicited during chronic exposure to As, as evidenced by the increase in endogenous reduced glutathione content and glutathione-related enzymatic activities such as glutathione S-transferase (GST) and glutathione reductase. This protective response might prevent a deeper decline in the antioxidant system and further oxidative damage. Alternatively, it might be linked to As conjugation with reduced glutathione for its excretion. Considering the sustained increase in GST activity and the decrease in the total antioxidant reactive potential observed, the authors propose them as good candidates to be used as biomarkers during As exposure. Interestingly, glutathione reductase activity was inhibited at a very low concentration of As considered safe for aquatic life. Environ Toxicol Chem 2017;36:1614-1621. © 2016 SETAC. © 2016 SETAC.

  14. Evaluation of the Possible Sources and Controlling Factors of Toxic Metals/Metalloids in the Florida Everglades and Their Potential Risk of Exposure.

    Science.gov (United States)

    Li, Yanbin; Duan, Zhiwei; Liu, Guangliang; Kalla, Peter; Scheidt, Daniel; Cai, Yong

    2015-08-18

    The Florida Everglades is an environmentally sensitive wetland ecosystem with a number of threatened and endangered fauna species susceptible to the deterioration of water quality. Several potential toxic metal sources exist in the Everglades, including farming, atmospheric deposition, and human activities in urban areas, causing concerns of potential metal exposure risks. However, little is known about the pollution status of toxic metals/metalloids of potential concern, except for Hg. In this study, eight toxic metals/metalloids (Cd, Cr, Pb, Ni, Cu, Zn, As, and Hg) in Everglades soils were investigated in both dry and wet seasons. Pb, Cr, As, Cu, Cd, and Ni were identified to be above Florida SQGs (sediment quality guidelines) at a number of sampling sites, particularly Pb, which had a level of potential risk to organisms similar to that of Hg. In addition, a method was developed for quantitative source identification and controlling factor elucidation of toxic metals/metalloids by introducing an index, enrichment factor (EF), in the conventional multiple regression analysis. EFs represent the effects of anthropogenic sources on metals/metalloids in soils. Multiple regression analysis showed that Cr and Ni were mainly controlled by anthropogenic loading, whereas soil characteristics, in particular natural organic matter (NOM), played a more important role for Hg, As, Cd, and Zn. NOM may control the distribution of these toxic metals/metalloids by affecting their mobility in soils. For Cu and Pb, the effects of EFs and environmental factors are comparable, suggesting combined effects of loading and soil characteristics. This study is the first comprehensive research with a vast amount of sampling sites on the distribution and potential risks of toxic metals/metalloids in the Everglades. The finding suggests that in addition to Hg other metals/metalloids could also potentially be an environmental problem in this wetland ecosystem.

  15. Chemical mixtures in untreated water from public-supply wells in the U.S. — Occurrence, composition, and potential toxicity

    International Nuclear Information System (INIS)

    Toccalino, Patricia L.; Norman, Julia E.; Scott, Jonathon C.

    2012-01-01

    Chemical mixtures are prevalent in groundwater used for public water supply, but little is known about their potential health effects. As part of a large-scale ambient groundwater study, we evaluated chemical mixtures across multiple chemical classes, and included more chemical contaminants than in previous studies of mixtures in public-supply wells. We (1) assessed the occurrence of chemical mixtures in untreated source-water samples from public-supply wells, (2) determined the composition of the most frequently occurring mixtures, and (3) characterized the potential toxicity of mixtures using a new screening approach. The U.S. Geological Survey collected one untreated water sample from each of 383 public wells distributed across 35 states, and analyzed the samples for as many as 91 chemical contaminants. Concentrations of mixture components were compared to individual human-health benchmarks; the potential toxicity of mixtures was characterized by addition of benchmark-normalized component concentrations. Most samples (84%) contained mixtures of two or more contaminants, each at concentrations greater than one-tenth of individual benchmarks. The chemical mixtures that most frequently occurred and had the greatest potential toxicity primarily were composed of trace elements (including arsenic, strontium, or uranium), radon, or nitrate. Herbicides, disinfection by-products, and solvents were the most common organic contaminants in mixtures. The sum of benchmark-normalized concentrations was greater than 1 for 58% of samples, suggesting that there could be potential for mixtures toxicity in more than half of the public-well samples. Our findings can be used to help set priorities for groundwater monitoring and suggest future research directions for drinking-water treatment studies and for toxicity assessments of chemical mixtures in water resources. - Highlights: ► We assessed mixtures in untreated groundwater samples from public-supply wells. ► A screening

  16. Biofabrication of Ag nanoparticles using Sterculia foetida L. seed extract and their toxic potential against mosquito vectors and HeLa cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Rajasekharreddy, Pala; Rani, Pathipati Usha, E-mail: usharani65@yahoo.com

    2014-06-01

    A one-step and eco-friendly process for the synthesis of silver-(protein-lipid) nanoparticles (Ag-PL NPs) (core–shell) has been developed using the seed extract from wild Indian Almond tree, Sterculia foetida (L.) (Sterculiaceae). The reaction temperature played a major role in controlling the size and shell formation of NPs. The amount of NPs synthesized and qualitative characterization was done by UV–vis spectroscopy and transmission electron microscopy (TEM), respectively. TEM studies exhibited controlled dispersity of spherical shaped NPs with an average size of 6.9 ± 0.2 nm. Selected area electron diffraction (SAED) and X-ray diffraction (XRD) revealed ‘fcc’ phase and crystallinity of the particles. X-ray photoelectron spectroscopy (XPS) was used to identify the protein–lipid (PL) bilayer that appears as a shell around the Ag core particles. The thermal stability of the Ag-PL NPs was examined using thermogravimetric analysis (TGA). Further analysis was carried out by using Fourier transform infrared spectroscopy (FTIR), where the spectra provided evidence for the presence of proteins and lipid moieties ((2n-octylcycloprop-1-enyl)-octanoic acid (I)), and their role in synthesis and stabilization of Ag NPs. This is the first report of plant seed assisted synthesis of PL conjugated Ag NPs. These formed Ag-PL NPs showed potential mosquito larvicidal activity against Aedes aegypti (L.), Anopheles stephensi Liston and Culex quinquefasciatus Say. These Ag-PL NPs can also act as promising agents in cancer therapy. They exhibited anti-proliferative activity against HeLa cancer cell lines and a promising toxicity was observed in a dose dependent manner. Toxicity studies were further supported by the cellular DNA fragmentation in the Ag-PL NPs treated HeLa cells. - Highlights: • Green synthesis of protein-lipid conjugated Ag NPs using S. foetida L. seed extract. • S. foetida seed extract acted as good reducing and stabilizing agent for Ag NPs. • XPS and

  17. The potential for methane hydrate formation in deep repositories of spent nuclear fuel in granitic rocks

    International Nuclear Information System (INIS)

    Tohidi, Bahman; Chapoy, Antonin; Smellie, John; Puigdomenech, Ignasi

    2010-12-01

    The main aim of this work was to establish whether the pertaining pressure and temperature conditions and dissolved gas concentration in groundwater is conducive to gas hydrate formation using a modelling approach. The hydrate stability pressure-temperature zone of dissolved methane in the presence of salt has been obtained through calculations which show that a decrease in the system pressure and/or an increase in salt concentration favours hydrate formation, as both factors reduce equilibrium gas solubility in the aqueous phase. This behaviour is unlike that of the system including a gas phase, where the water phase is always saturated with methane, and hence the methane solubility in water is not a limiting factor. The main conclusion is that hydrate formation is not possible at the reported methane concentrations and water salinities for the Forsmark and Laxemar sites in Sweden and Olkiluoto in Finland. At the highest salinities and methane concentrations encountered, namely ∼0.00073 mole fraction methane and ∼10 mass % NaCl at a depth of 1,000 m in Olkiluoto, Finland, hydrates could form if the system temperatures and pressures are below 2.5 deg C and 60 bar, respectively, i.e. values that are much lower than those prevailing at that depth (∼20 deg C and ∼100 bar, respectively). Furthermore, the calculated results provide the necessary data to estimate the effect of increase in dissolved methane concentration on potential hydrate formation, as well as two phase flow. The available depth dependency of methane concentration at the sites studied in Sweden and Finland was used in another study to estimate the diffusive flow of methane in the rock volumes. These diffusion rates, which are highest at Olkiluoto, indicate that even if the conditions were to become favourable to methane hydrate formation, then it would take several millions of years before a thin layer of hydrates could be formed, a condition which is outside the required period of satisfactory

  18. The potential for methane hydrate formation in deep repositories of spent nuclear fuel in granitic rocks

    Energy Technology Data Exchange (ETDEWEB)

    Tohidi, Bahman; Chapoy, Antonin (Hydrafact Ltd, Inst. of Petroleum Engineering, Heriot-Watt Univ., Edinburgh (United Kingdom)); Smellie, John (Conterra AB, Uppsala (Sweden)); Puigdomenech, Ignasi (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden))

    2010-12-15

    The main aim of this work was to establish whether the pertaining pressure and temperature conditions and dissolved gas concentration in groundwater is conducive to gas hydrate formation using a modelling approach. The hydrate stability pressure-temperature zone of dissolved methane in the presence of salt has been obtained through calculations which show that a decrease in the system pressure and/or an increase in salt concentration favours hydrate formation, as both factors reduce equilibrium gas solubility in the aqueous phase. This behaviour is unlike that of the system including a gas phase, where the water phase is always saturated with methane, and hence the methane solubility in water is not a limiting factor. The main conclusion is that hydrate formation is not possible at the reported methane concentrations and water salinities for the Forsmark and Laxemar sites in Sweden and Olkiluoto in Finland. At the highest salinities and methane concentrations encountered, namely approx0.00073 mole fraction methane and approx10 mass % NaCl at a depth of 1,000 m in Olkiluoto, Finland, hydrates could form if the system temperatures and pressures are below 2.5 deg C and 60 bar, respectively, i.e. values that are much lower than those prevailing at that depth (approx20 deg C and approx100 bar, respectively). Furthermore, the calculated results provide the necessary data to estimate the effect of increase in dissolved methane concentration on potential hydrate formation, as well as two phase flow. The available depth dependency of methane concentration at the sites studied in Sweden and Finland was used in another study to estimate the diffusive flow of methane in the rock volumes. These diffusion rates, which are highest at Olkiluoto, indicate that even if the conditions were to become favourable to methane hydrate formation, then it would take several millions of years before a thin layer of hydrates could be formed, a condition which is outside the required period of

  19. Summary of Model Toxics Control Act (MTCA) Potential Impacts Related to Hanford Cleanup and the Tri-Party Agreement (TPA)

    Energy Technology Data Exchange (ETDEWEB)

    IWATATE, D.F.

    2000-07-14

    This white paper provides an initial assessment of the potential impacts of the Model Toxics Control Act (MTCA) regulations (and proposed revisions) on the Hanford site cleanup and addresses concerns that MTCA might impose inappropriate or unachievable clean-up levels and drive clean-up costs higher. The white paper and supporting documentation (Appendices A and B) provide DOE with a concise and up-to-date review of potential MTCA impacts to cost and schedule for the Hanford site activities. MTCA, Chapter 70.105D RCW, is the State of Washington's risk based law governing clean-up of contaminated sites and is implemented by The Washington Department of Ecology (Ecology) under the MTCA Clean-up Regulations, Chapter 173-340 WAC. Hanford cleanup is subject to the MTCA requirements as Applicable, Relevant and Appropriate Requirements (ARARs) for those areas of Hanford being managed under the authority of the Federal Resource Conservation and Recovery Act (RCRA), Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), and the state Dangerous Waste Regulations. MTCA provides Ecology with authority to implement site clean-up actions under both the federal RCRA and CERCLA regulations as well as the state regulations. Most of the Hanford clean-up actions are being implemented under the CERCLA program, however, there is a trend is toward increased use of MTCA procedures and standards. The application of MTCA to the Hanford clean-up has been an evolving process with some of the Hanford clean-up actions considering MTCA standards as an ARAR and using MTCA procedures for remedy selection. The increased use and application of MTCA standards and procedures could potentially impact both cost and schedule for the Hanford cleanup.

  20. Toxicity of silver nanoparticles and ionic silver: Comparison of adverse effects and potential toxicity mechanisms in the freshwater clam Sphaerium corneum.

    Science.gov (United States)

    Völker, Carolin; Kämpken, Inga; Boedicker, Cathinka; Oehlmann, Jörg; Oetken, Matthias

    2015-01-01

    A range of studies has addressed possible environmental impacts of nanosilver, but most focused on acute effects in few species. Moreover, it remains unclear if toxic effects are particle-specific or mediated by released silver ions. We investigated chronic effects of nanosilver and soluble silver (AgNO3) on the freshwater bivalve Sphaerium corneum. Animals were exposed to nanosilver (0-500 μg Ag L(-1)) and AgNO3 (0-318 μg Ag L(-1)) over 28 days, and effects on reproduction and behavioral changes were assessed. To explore toxic mechanisms, we evaluated the effects on intracellular levels of reactive oxygen species (ROS) and the activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione-S-transferase, glutathione peroxidase). We further explored the activity of the sodium-potassium adenosine triphosphatase (Na(+)/K(+)-ATPase). Chronic exposure to nanosilver and AgNO3 resulted in negative effects on reproduction at concentrations of 5 and 3.18 µg Ag L(-1) (LOEC), respectively. ROS levels significantly increased after exposure to nanosilver at 10 µg Ag L(-1) and AgNO3 at 63.5 µg Ag L(-1). Both forms of silver altered the activities of antioxidant enzymes. Nanosilver (500 μg Ag L(-1)) and AgNO3 (318 μg Ag L(-1)) inhibited Na(+)/K(+)-ATPase activity by 82.6 and 78.9%, respectively. Nanoparticulate and soluble silver produced similar effects in S. corneum suggesting that toxicity of nanosilver is mainly mediated by dissolution of nanoparticles in the test media or after uptake by the test organisms.

  1. Perchlorate formation on Mars through surface radiolysis-initiated atmospheric chemistry: A potential mechanism

    Science.gov (United States)

    Wilson, Eric H.; Atreya, Sushil K.; Kaiser, Ralf I.; Mahaffy, Paul R.

    2016-08-01

    Recent observations of the Martian surface by the Phoenix lander and the Sample Analysis at Mars indicate the presence of perchlorate (ClO4-). The abundance and isotopic composition of these perchlorates suggest that the mechanisms responsible for their formation in the Martian environment may be unique in our solar system. With this in mind, we propose a potential mechanism for the production of Martian perchlorate: the radiolysis of the Martian surface by galactic cosmic rays, followed by the sublimation of chlorine oxides into the atmosphere and their subsequent synthesis to form perchloric acid (HClO4) in the atmosphere, and the surface deposition and subsequent mineralization of HClO4 in the regolith to form surface perchlorates. To evaluate the viability of this mechanism, we employ a one-dimensional chemical model, examining chlorine chemistry in the context of Martian atmospheric chemistry. Considering the chlorine oxide, OClO, we find that an OClO flux as low as 3.2 × 107 molecules cm-2 s-1 sublimated into the atmosphere from the surface could produce sufficient HClO4 to explain the perchlorate concentration on Mars, assuming an accumulation depth of 30 cm and integrated over the Amazonian period. Radiolysis provides an efficient pathway for the oxidation of chlorine, bypassing the efficient Cl/HCl recycling mechanism that characterizes HClO4 formation mechanisms proposed for the Earth but not Mars.

  2. Event-related brain potential correlates of human auditory sensory memory-trace formation.

    Science.gov (United States)

    Haenschel, Corinna; Vernon, David J; Dwivedi, Prabuddh; Gruzelier, John H; Baldeweg, Torsten

    2005-11-09

    The event-related potential (ERP) component mismatch negativity (MMN) is a neural marker of human echoic memory. MMN is elicited by deviant sounds embedded in a stream of frequent standards, reflecting the deviation from an inferred memory trace of the standard stimulus. The strength of this memory trace is thought to be proportional to the number of repetitions of the standard tone, visible as the progressive enhancement of MMN with number of repetitions (MMN memory-trace effect). However, no direct ERP correlates of the formation of echoic memory traces are currently known. This study set out to investigate changes in ERPs to different numbers of repetitions of standards, delivered in a roving-stimulus paradigm in which the frequency of the standard stimulus changed randomly between stimulus trains. Normal healthy volunteers (n = 40) were engaged in two experimental conditions: during passive listening and while actively discriminating changes in tone frequency. As predicted, MMN increased with increasing number of standards. However, this MMN memory-trace effect was caused mainly by enhancement with stimulus repetition of a slow positive wave from 50 to 250 ms poststimulus in the standard ERP, which is termed here "repetition positivity" (RP). This RP was recorded from frontocentral electrodes when participants were passively listening to or actively discriminating changes in tone frequency. RP may represent a human ERP correlate of rapid and stimulus-specific adaptation, a candidate neuronal mechanism underlying sensory memory formation in the auditory cortex.

  3. THEORY OF GENERATIONS AS A TOOL FOR ANALYSIS, FORMATION AND DEVELOPMENT OF LABOUR POTENTIAL

    Directory of Open Access Journals (Sweden)

    I. M. Gurova

    2016-01-01

    Full Text Available The modern Strauss–Howe generational theory created at the intersection of economic, sociological, historical and psychological Sciences. She focuses primarily on difference of attitudes of generations, due to the specific social environment, corresponding to a certain period of time. Such a perspective on issues related to the human factor in the economy, has recently attracted interest not only from researchers, but also finds application for solving practical problems in some fields of business.Subject / theme. The article is devoted to one of the urgent contemporary socio-economic problems – the issue of the formation and development of labor potential. In this context, the theory of generations is offered by the authors as a tool for the study of qualitative parameters of human resources and the planning of future work opportunities in our country. In particular, the article considers the main aspects of the classical version of the Strauss–Howe generational theory and its Russian adaptation. Statistics describing the General demographics and working population of Russia from the point of view of generational groups. On this basis, a forecast is made of the labor potential of the country in the long term structure, review and compare the basic values and business characteristics of its constituent generations. Problem areas for which use of generational approach is rational are revealed and the corresponding recommendations are made.Objectives. The purpose of this article is justification of the possible application of provisions of modern theories of generations to identify and predict the dynamics of qualitative characteristics of the domestic workforce, as well as the prospects of its use in order to control the formation and development of labor potential.Methods. Methodological basis of the presented work make comparative and economic-statistical and socio-cultural methods of analysis.Results. In the framework of this article

  4. Potential barriers governing the C12 formation and decay through quasimolecular shapes

    Science.gov (United States)

    Royer, G.; Escudie, A.; Sublard, B.

    2014-08-01

    The L-dependent potential barriers that govern the Be8 and C12 formation and decay through quasimolecular shapes have been determined using a generalized liquid-drop model and adjusted to reproduce the experimental Q value. For the ternary channel of C12, the energies of prolate linear chain configurations and oblate triangular configurations of three α particles have been compared. The triangular shape with three α nuclei in contact allows the experimental rms radius and the negative quadrupole moment of the C12 ground state to be reproduced. The difference between the energies of the minima in the prolate and oblate ternary shape paths is very close to the energy of the excited Hoyle state of the C12 nucleus.

  5. Potential of microbial methane formation in a high-temperature hydrocarbon seep

    International Nuclear Information System (INIS)

    Ling, Yu-Chen; Chen, Yun-Ju; Sun, Chih-Hsien; Cheng, Ting-Wen; Wang, Pei-Ling; Lin, Li-Hung

    2012-01-01

    Hydrocarbon seepage is a surface expression where fluids mixed with sediments and hydrocarbons are expelled through fracture systems that potentially tap into gas–petroleum reservoirs. Hydrocarbons released from most seeps appear to be thermogenic on the basis of their relative abundance and isotopic composition. The potential for subsurface microbial processes modifying these geochemical fingerprints remains poorly constrained. In this study, microcosm incubations were conducted on mud slurries supplied with/without various methanogenic precursors at temperatures ranging from ambient conditions to 90 °C, in order to assess microbial CH 4 formation in the subsurface beneath hydrocarbon seeps. The analyses indicated that CH 4 production was positive at ⩽80 °C, regardless of whether or not or which precursors were added. However, the pattern of CH 4 production rates varied with the precursor and temperature. In general, the optimum CH 4 production from H 2 /CO 2 and formate occurred over a wide range of temperatures (⩾40 °C), whereas that from acetate, methanol and methylamine was restricted to relatively lower temperatures (40–50 °C). The CH 4 recoveries, together with the C isotopic compositions of CH 4 , further indicated that the quantities of CH 4 produced could not completely account for the quantities of precursor consumed, suggesting that a complex metabolic network was involved in the transformation of the added precursor and organic C inherited from inoculated sediments. Microbial CH 4 was estimated to constitute 7–61% of the CH 4 observed using experimentally-derived apparent isotope fractionations as the end member compositions. This illustrates the possibility that microbial CH 4 produced at shallower depths could quantitatively and isotopically alter deeply-sourced thermogenic CH 4 in hydrocarbon seep environments.

  6. Bioavailability and health risk of some potentially toxic elements (Cd, Cu, Pb and Zn) in street dust of Asansol, India.

    Science.gov (United States)

    Gope, Manash; Masto, Reginald Ebhin; George, Joshy; Hoque, Raza Rafiqul; Balachandran, Srinivasan

    2017-04-01

    Street dust samples were collected from five different types of land use patterns (busy traffic zone, urban residential area, national highways, industrial area and sensitive area) in a medium sized industrial city Asansol, India. The samples were fractionated into ≤53µm and analyzed for potential toxic elements (PTEs) viz. Zn, Cd, Pb and Cu. The mean total concentration of Zn, Cd, Pb and Cu in the urban street dust samples were 192, 0.75, 110 and 132mgkg -1 respectively. Chemical speciation was performed for PTEs to evaluate the bio-available fractions. Cu was mostly associated with organic matter phase while Zn, Pb and Cd with residual phase. Mean mobility factor (MF) for heavy metals in Asansol was Zn (54.6%)>Pb (49.1%)>Cu (25.3%)>Cd (22.7%). Geo-chemical indices such as Enrichment Factor (EF), geo-accumulation index (Igeo) and contamination Factor (CF) were in the order of Pb>Cd>Zn>Cu. Cluster analysis was done to understand the similarities among the sites. The risks of all metals was calculated with mobile fraction, which indicated actual risk due to PTEs was less (HI<1). Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Radioprotective potential of Decalepis hamiltonii: a study on gamma radiation-induced oxidative stress and toxicity in Drosophila melanogaster

    International Nuclear Information System (INIS)

    Pasha, Muzeer; Shivanandappa, T.; Ramesh, S.R.; Sanjeev, Ganesh

    2016-01-01

    Radiation-induced damage to normal tissues restricts the therapeutic use of radiation in clinical application for cancer treatment and thereby limits the efficacy of the treatment. The use of chemical compounds as radioprotectors is a desirable strategy to improve the therapeutic index of radiotherapy. However, most of the synthetic radioprotective compounds studied have shown to have undesirable properties of toxicity. There is a need for safer, natural radioprotective agents without compromising efficacy of the treatment. We have investigated the radioprotective potential of Decalepis hamiltonii (Dh) root extract which is rich in natural antioxidants by employing Drosophila melanogaster as a model. Irradiation of Drosophila with 100, 200, and 400 Gy of gamma radiation induced dose-dependent mortality. Elevation in the levels of thiobarbituric acid reactive substances (TBARS), the activities of catalase (CAT) and superoxide dismutase (SOD), and depletion of glutathione (GSH) content suggested radiation-induced oxidative stress. Pretreatment of flies with Dh root extract protected them from radiation-induced mortality and oxidative stress as evidenced by reduction in TBARS and restoration of the antioxidant enzymes, SOD and CAT, and GSH to control levels. This is the first report of radioprotective action of Dh root extract in D. melanogaster. (author)

  8. Assessment of female reproductive endpoints in Sprague-Dawley rats developmentally exposed to Diuron: potential ovary toxicity.

    Science.gov (United States)

    Grassi, Tony Fernando; Guerra, Marina Trevisan; Perobelli, Juliana Elaine; de Toledo, Fabíola Choqueta; da Silva, Denise Salioni; De Grava Kempinas, Wilma; Barbisan, Luís Fernando

    2011-10-01

    Diuron is widely used in agriculture but its deleterious effects on the reproductive system and mammary gland are still poorly understood. This study evaluated whether early-life-stage exposure to Diuron alters puberty onset or susceptibility to mammary carcinogenesis in female Sprague-Dawley rats. Pregnant rats received basal diet or diet containing Diuron at 500, 750, and 1,250 ppm, from gestational day 12 to the end of lactation (postnatal day 21 [PND21]). After weaning, female offspring continued receiving basal diet or diet containing Diuron until PND 51. At PND 51, female Sprague-Dawley offspring received a single dose of 50 mg/kg b.w. of 7,12-dimethylbenz(a)anthracene (DMBA) for initiation of mammary carcinogenesis. The animals were sacrificed on PND 51, 75, and 226 to 233 (week 25) for mammary gland morphology, reproductive organs and tumor analysis, respectively. There were no significant differences among groups on vaginal opening, estrous cycle, mammary morphology, or carcinogenesis. However, reductions in ovary weight and corpora lutea were observed at PND 75 in the group treated with Diuron at 1,250 ppm. The findings suggesting that Diuron exposure (1,250 ppm) may have been potentially toxic to the ovaries. © 2011 Wiley Periodicals, Inc.

  9. Fractionation and potential toxic risk of metals from superficial sediment in Itaipu Lake--boundary between Brazil and Paraguay.

    Science.gov (United States)

    Kalwa, Miguel; Quináia, Sueli Pércio; Pletsch, Adelmo L; Techy, Laura; Felsner, Maria Lurdes

    2013-01-01

    The objective of this study was to evaluate fractions of metals (labile and pseudo-total) extracted from sediment samples collected in Itaipu Lake (boundary between Brazil and Paraguay) and to assess the dynamics and mobility of these fractions by identifying the same bioavailability and ecological risk to metals in the aquatic environment. The concentrations of metal ions were determined by flame atomic absorption spectrometry. There was a correlation between the metal ions, both in the labile and the pseudo-total, with regard to particle size. To assess metals concentrations in sediment, numerical sediment-quality guidelines were applied. The concentrations of aluminum, cadmium, iron, manganese, lead, and zinc in all sediment samples are lower than the proposed probable effects level (PEL), thus possibly indicating that there are no harmful effects from these metals. In contrast, concentrations of copper, chromium, and nickel exceeded the PEL in some samples, thus indicating that these stations are at potential risk. The level of contamination in sediments of Itaipu Lake for all metals was evaluated using contamination factor, degree of contamination, and sum-of-metals toxic unit.

  10. Biochars mitigate greenhouse gas emissions and bioaccumulation of potentially toxic elements and arsenic speciation in Phaseolus vulgaris L.

    Science.gov (United States)

    Ibrahim, Muhammad; Li, Gang; Khan, Sardar; Chi, Qiaoqiao; Xu, Yaoyang

    2017-08-01

    Anthropogenic and natural activities can lead to increased greenhouse gas emissions and discharge of potentially toxic elements (PTEs) into soil environment. Biochar amendment to soils is a cost-effective technology and sustainable approach used to mitigate greenhouse gas emissions, improve phytoremediation, and minimize the health risks associated with consumption of PTE-contaminated vegetables. Greenhouse pot experiments were conducted to investigate the effects of peanut shell biochar (PNB) and sewage sludge biochar (SSB) on greenhouse gas (GHG) emissions, plant growth, PTE bioaccumulation, and arsenic (As) speciation in bean plants. Results indicated that amendments of PNB and SSB increased plant biomass production by increasing soil fertility and reducing bioavailability of PTEs. Addition of biochars also increased soil pH, total nitrogen (TN), total carbon (TC), dissolved organic carbon (DOC), and ammonium-nitrogen (NH 4 -N) but decreased available concentrations of PTEs such as cadmium (Cd), lead (Pb), and As. The concentration of nitrate-nitrogen (NO 3 - -N) was also decreased in biochar-amended soils. In addition, PNB and SSB amendments significantly (P carbon dioxide (CO 2 ) and methane (CH 4 ) emissions were significantly (P emissions first increased and then decreased amended with both biochars. Current findings demonstrate that SSB and PNB are two beneficial soil amendments simultaneous mitigating greenhouse gas emissions and PTE bioaccumulation as well as arsenic speciation in P. vulgaris L.

  11. Levels of potentially toxic metals in water, sediment and peat from Wonderfonteinspruit, North West Province, South Africa.

    Science.gov (United States)

    Nsaka, Ntumba C; McCrindle, Robert I; Ambushe, Abayneh A

    2018-04-30

    Environmental monitoring of the levels of potentially toxic metals is of importance because of possible adverse effects on living species. This study was conducted to assess the levels of Cd, Cr, Cu, Hg, Mn, Pb, U and V in water, sediment and peat samples collected from the region of Wonderfonteinspruit. Water samples were simply filtered and acidified with HNO 3 prior to analysis. Sediment and peat were oven-dried, ground, sieved and mineralised using a microwave digestion system. Concentrations of the selected elements in all samples were determined by inductively coupled plasma-mass spectrometry. A Zeeman mercury analyser was also used for quantification of Hg in the same sediment and peat samples. The method validation was carried out using SRM 1643e water and BCR 320R sediment certified reference materials. The results showed no significant difference at 95% level of confidence between the certified and measured values after using the Student's t-test. The levels of Cd, Cr, Cu, Pb, V and U found in rivers and dams were lower than the tentative South African water quality range guideline for domestic and irrigation purposes. However, water from dams and certain rivers was unsuitable for irrigation and domestic use.

  12. Effects of biochar and the earthworm Eisenia fetida on the bioavailability of polycyclic aromatic hydrocarbons and potentially toxic elements

    International Nuclear Information System (INIS)

    Gomez-Eyles, Jose L.; Sizmur, Tom; Collins, Chris D.; Hodson, Mark E.

    2011-01-01

    Polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) were monitored over 56 days in calcareous contaminated-soil amended with either or both biochar and Eisenia fetida. Biochar reduced total (449 to 306 mg kg -1 ) and bioavailable (cyclodextrin extractable) (276 to 182 mg kg -1 ) PAHs, PAH concentrations in E. fetida (up to 45%) but also earthworm weight. Earthworms increased PAH bioavailability by >40%. Combined treatment results were similar to the biochar-only treatment. Earthworms increased water soluble Co (3.4 to 29.2 mg kg -1 ), Cu (60.0 to 120.1 mg kg -1 ) and Ni (31.7 to 83.0 mg kg -1 ) but not As, Cd, Pb or Zn; biochar reduced water soluble Cu (60 to 37 mg kg -1 ). Combined treatment results were similar to the biochar-only treatment but gave a greater reduction in As and Cd mobility. Biochar has contaminated land remediation potential, but its long-term impact on contaminants and soil biota needs to be assessed. - Research highlights: → Biochar reduced total and bioavailable PAH concentrations. → Biochar was less effective at immobilising PTEs, due to its low cation exchange capacity. → E. fetida increased PAH bioavailability and PTE mobility. → When used in combination biochar reduced the concentration of PTEs mobilised by E. fetida. → Biochar had a negative effect on E. fetida in terms of weight loss. - Biochar decreased PAH biovailability but was less effective at reducing PTE mobility, whilst E. fetida increased both PAH and PTE bioavailability.

  13. Effects of biochar and the earthworm Eisenia fetida on the bioavailability of polycyclic aromatic hydrocarbons and potentially toxic elements

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Eyles, Jose L., E-mail: j.l.gomezeyles@reading.ac.u [University of Reading, School of Human and Environmental Sciences, Soil Research Centre, Reading, RG6 6DW Berkshire (United Kingdom); Sizmur, Tom; Collins, Chris D.; Hodson, Mark E. [University of Reading, School of Human and Environmental Sciences, Soil Research Centre, Reading, RG6 6DW Berkshire (United Kingdom)

    2011-02-15

    Polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) were monitored over 56 days in calcareous contaminated-soil amended with either or both biochar and Eisenia fetida. Biochar reduced total (449 to 306 mg kg{sup -1}) and bioavailable (cyclodextrin extractable) (276 to 182 mg kg{sup -1}) PAHs, PAH concentrations in E. fetida (up to 45%) but also earthworm weight. Earthworms increased PAH bioavailability by >40%. Combined treatment results were similar to the biochar-only treatment. Earthworms increased water soluble Co (3.4 to 29.2 mg kg{sup -1}), Cu (60.0 to 120.1 mg kg{sup -1}) and Ni (31.7 to 83.0 mg kg{sup -1}) but not As, Cd, Pb or Zn; biochar reduced water soluble Cu (60 to 37 mg kg{sup -1}). Combined treatment results were similar to the biochar-only treatment but gave a greater reduction in As and Cd mobility. Biochar has contaminated land remediation potential, but its long-term impact on contaminants and soil biota needs to be assessed. - Research highlights: Biochar reduced total and bioavailable PAH concentrations. Biochar was less effective at immobilising PTEs, due to its low cation exchange capacity. E. fetida increased PAH bioavailability and PTE mobility. When used in combination biochar reduced the concentration of PTEs mobilised by E. fetida. Biochar had a negative effect on E. fetida in terms of weight loss. - Biochar decreased PAH biovailability but was less effective at reducing PTE mobility, whilst E. fetida increased both PAH and PTE bioavailability.

  14. Evaluation of antibacterial potential and toxicity of plant volatile compounds using new broth microdilution volatilization method and modified MTT assay.

    Science.gov (United States)

    Houdkova, Marketa; Rondevaldova, Johana; Doskocil, Ivo; Kokoska, Ladislav

    2017-04-01

    With aim to develop effective proof-of-concept approach which can be used in a development of new preparations for the inhalation therapy, we designed a new screening method for simple and rapid simultaneous determination of antibacterial potential of plant volatiles in the liquid and the vapour phase at different concentrations. In addition, EVA (ethylene vinyl acetate) capmat™ as vapour barrier cover was used as reliable modification of thiazolyl blue tetrazolium bromide (MTT) assay for cytotoxicity testing of volatiles on microtiter plates. Antibacterial activity of carvacrol, cinnamaldehyde, eugenol, 8-hydroxyquinoline, thymol and thymoquinone was determined against Haemophilus influenzae, Staphylococcus aureus, and Streptococcus pneumoniae using new broth microdilution volatilization method. The cytotoxicity of these compounds was evaluated using MTT test in lung fibroblast cells MRC-5. The most effective antibacterial agents were 8-hydroxyquinoline and thymoquinone with the lowest minimum inhibitory concentrations (MICs) ranging from 2 to 128μg/mL, but they also possessed the highest toxicity in lung cell lines with half maximal inhibitory concentration (IC 50 ) values 0.86-2.95μg/mL. The lowest cytotoxicity effect was identified for eugenol with IC 50 295.71μg/mL, however this compound produced only weak antibacterial potency with MICs 512-1024μg/mL. The results demonstrate validity of our novel broth microdilution volatilization method, which allows cost and labour effective high-throughput antimicrobial screening of volatile agents without need of special apparatus. In our opinion, this assay can also potentially be used for development of various medicinal, agricultural, and food applications that are based on volatile antimicrobials. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Diversity in oat potential immunogenicity: basis for the selection of oat varieties with no toxicity in coeliac disease

    Science.gov (United States)

    Comino, Isabel; Real, Ana; de Lorenzo, Laura; Cornell, Hugh; López-Casado, Miguel Ángel; Barro, Francisco; Lorite, Pedro; Torres, Ma Isabel; Cebolla, Ángel

    2011-01-01

    Background and aims Coeliac disease (CD) is triggered by an abnormal reaction to gluten. Peptides resulting from partially digested gluten of wheat, barley or rye cause inflammation of the small intestinal mucosa. Previous contradictory studies suggest that oats may trigger the abnormal immunological response in patients with CD. Monoclonal antibodies (moAbs) against the main immunotoxic 33-mer peptide (A1 and G12) react strongly against wheat, barley and rye but have less reactivity against oats. The stated aim of this study is to test whether this observed reactivity could be related to the potential toxicity of oats for patients with CD. Methods In the present study, different oat varieties, controlled for their purity and by their distinct protein pattern, were used to examine differences in moAb G12 recognition by ELISA and western blot. Immunogenicity of oat varieties was determined by 33-mer concentration, T cell proliferation and interferon γ production. Results Three groups of oat cultivars reacting differently against moAb G12 could be distinguished: a group with considerable affinity, a group showing slight reactivity and a third with no detectable reactivity. The immunogenicity of the three types of oats as well as that of a positive and negative control was determined with isolated peripheral blood mononuclear T cells from patients with CD by measurement of cell proliferation and interferon γ release. A direct correlation of the reactivity with G12 and the immunogenicity of the different prolamins was observed. Conclusions The results showed that the reactivity of the moAb G12 is proportional to the potential immunotoxicity of the cereal cultivar. These differences may explain the different clinical responses observed in patients suffering from CD and open up a means to identify immunologically safe oat cultivars, which could be used to enrich a gluten-free diet. PMID:21317420

  16. [MIG7 Regulates the Vasculogenic Mimicry Formation in Hepatocellular Carcinoma then Effects the Metastasis Potential of HCC].

    Science.gov (United States)

    Qu, Bo; Yu, Fei; Sheng, Guan-Nan; Chen, Guan-Nan; Lü, Qi; Gu, Yan-Jun; Guo, Long

    2017-05-01

    To investigate the expression of migration-inducing gene 7 (MIG7) in different HCC lines and its relationship with vasculogenic mimicry (VM) formation and metastatic potentiality. Employing immunostaining to detect MIG7 protein expression and VM formation in 40 matched pairs of primary and metastatic HCC specimens from 40 patients, and investigating the correlation of VM formation with MIG7 protein expression. Detecting VM formation in HCC lines with different metastatic ability (MHCC-97H, MHCC-97L, Huh-7) and human normal hepatocyte line (L-02) through three-dimensional culture, and detecting MIG7 mRNA expression with RT-PCR, investigating the correlation of MIG7 protein expression with VM formation and HCC metastatic potentiality with Western blot assay; screening the HCC cell line with high MIG7 expression. In 40 matched pairs of HCC tissue, there was a significant positive correlation between MIG7 protein expression and VM formation ( r s =0.595, P HCC tissue is high and correlated positively with VM formation. MIG7 expression in different HCC cell lines is coincident with theirs VM formation, invasion and metastasis. MIG7 is a potential target for inhibiting the invasion and metastasis of HCC.

  17. Environmental Risk Assessment Based on High-Resolution Spatial Maps of Potentially Toxic Elements Sampled on Stream Sediments of Santiago, Cape Verde

    Directory of Open Access Journals (Sweden)

    Marina M. S. Cabral Pinto

    2014-10-01

    Full Text Available Geochemical mapping is the base knowledge to identify the regions of the planet with critical contents of potentially toxic elements from either natural or anthropogenic sources. Sediments, soils and waters are the vehicles which link the inorganic environment to life through the supply of essential macro and micro nutrients. The chemical composition of surface geological materials may cause metabolic changes which may favor the occurrence of endemic diseases in humans. In order to better understand the relationships between environmental geochemistry and public health, we present environmental risk maps of some harmful elements (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn in the stream sediments of Santiago, Cape Verde, identifying the potentially harmful areas in this island. The Estimated Background Values (EBV of Cd, Co, Cr, Ni and V were found to be above the Canadian guidelines for any type of use of stream sediments and also above the target values of the Dutch and United States guidelines. The Probably Effect Concentrations (PEC, above which harmful effects are likely in sediment dwelling organisms, were found for Cr and Ni. Some associations between the geological formations of the island and the composition of stream sediments were identified and confirmed by descriptive statistics and by Principal Component Analysis (PCA. The EBV spatial distribution of the metals and the results of PCA allowed us to establish relationships between the EBV maps and the geological formations. The first two PCA modes indicate that heavy metals in Santiago stream sediments are mainly originated from weathering of underlying bedrocks. The first metal association (Co, V, Cr, and Mn; first PCA mode consists of elements enriched in basic rocks and compatible elements. The second association of variables (Zn and Cd as opposed to Ni; second PCA mode appears to be strongly controlled by the composition of alkaline volcanic rocks and pyroclastic rocks. So, the

  18. Assessment of the potential for karst in the Rustler Formation at the WIPP site.

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, John Clay

    2006-01-01

    This report is an independent assessment of the potential for karst dissolution in evaporitic strata of the Rustler Formation at the Waste Isolation Pilot Plant (WIPP) site. Review of the available data suggests that the Rustler strata thicken and thin across the area in depositional patterns related to lateral variations in sedimentary accommodation space and normal facies changes. Most of the evidence that has been offered for the presence of karst in the subsurface has been used out of context, and the different pieces are not mutually supporting. Outside of Nash Draw, definitive evidence for the development of karst in the Rustler Formation near the WIPP site is limited to the horizon of the Magenta Member in drillhole WIPP-33. Most of the other evidence cited by the proponents of karst is more easily interpreted as primary sedimentary structures and the localized dissolution of evaporitic strata adjacent to the Magenta and Culebra water-bearing units. Some of the cited evidence is invalid, an inherited baggage from studies made prior to the widespread knowledge of modern evaporite depositional environments and prior to the existence of definitive exposures of the Rustler Formation in the WIPP shafts. Some of the evidence is spurious, has been taken out of context, or is misquoted. Lateral lithologic variations from halite to mudstone within the Rustler Formation under the WIPP site have been taken as evidence for the dissolution of halite such as that seen in Nash Draw, but are more rationally explained as sedimentary facies changes. Extrapolation of the known karst features in Nash Draw eastward to the WIPP site, where conditions are and have been significantly different for half a million years, is unwarranted. The volumes of insoluble material that would remain after dissolution of halite would be significantly less than the observed bed thicknesses, thus dissolution is an unlikely explanation for the lateral variations from halite to mudstone and siltstone

  19. High-throughput Screening of ToxCast™ Phase I Chemicals in a Mouse Embryonic Stem Cell (mESC) Assay Reveals Disruption of Potential Toxicity Pathways

    Science.gov (United States)

    Little information is available regarding the potential for many commercial chemicals to induce developmental toxicity. The mESC Adherent Cell Differentiation and Cytoxicity (ACDC) assay is a high-throughput screen used to close this data gap. Thus, ToxCast™ Phase I chemicals wer...

  20. Global change impact on oxidative potential and toxicity of atmospheric particles from the East Mediterranean basin: the ARCHIMEDES initiative

    Science.gov (United States)

    Alleman, Laurent; Anthérieu, Sébastien; Baeza-Squiban, Armelle; Garçon, Guillaume; Lo Guidice, Jean-Marc; Hamonou, Eric; Öztürk, Fatma; Perdrix, Esperanza; Rudich, Yinon; Sciare, Jean; Sauvage, Stéphane

    2017-04-01

    Climate change (CC) has important social, economical and health implications, notably in accordance with variation in air pollution or microbiome modification and its related toxicity mechanisms. CC will have a strong influence on meteorology, inducing dryer and warmer conditions in some regions. The Mediterranean basin is foreseen as a hotspot for regional climate warming, favoring larger dust episodes, wild fire events, vegetation emissions and changes in air pollution physic-chemical characteristics due to enhanced photochemical reactivity. Increasing concentrations of biogenic volatile organic compounds (VOCs), ozone, and radicals will be associated with rising concentrations of secondary organic aerosols (SOA) and other oxidized aerosols. These expected changes in aerosol composition are currently studied within the international ChArMEx (Chemistry-aerosol Mediterranean Experiment) program, part of the interdisciplinary MISTRALS metaprogramme (Mediterranean Integrated STudies at Regional And Local Scales). According to the LIFE/MED-PARTICLES (LIFE) project, this might result in more adverse effects on health. However, toxicologists are far from having a detailed mechanistic knowledge of the quantitative causal relations between particles (PM) and health effects suggested by epidemiological evidences. Detailed toxicological studies looking at contrasted PM origins and chemical compositions are highly needed, particularly on strongly aged SOA suspected to increase the oxidative potential (OP) and to enhance the toxicity of airborne particles. Intensive researches onto the underlying mechanisms of inflammation started to describe the outlines of the intricate relationship between oxidative stress and inflammation. It is therefore, of great importance to better determine the OP of PM from contrasted surroundings, its relationship with CC through PM's physical, chemical and microbial characteristics, and its toxicological consequences within the lungs. Recently

  1. Analysis on uranium mineralization-formation condition and prospecting potential in Xidamingshan metallogenic belt

    International Nuclear Information System (INIS)

    Li Zhixing; Qi Fucheng; He Zhongbo; Zhang Zilong

    2012-01-01

    There are many different opinions about the source of uranium and metallogenic mechanism in Xidamingshan metallogenic belt. therefore it blocked uranium resources potential evaluation and ore exploration. Through absorb in- formation and investigate Daxin deposit and systematic analysis on samples. It is believed that uranium source mainly came from Cambrian System, a little came from the deep. The Devonian System is favorable room for saving ores in addition to be pre-concentrated room for uranium. Also, there are new cognition about uranium metallogenic mechanism, establish ore-forming series of Xidamingshan metallogenic belt, It is proposed that uranium mineralization have experienced 4 stages; It is cleared that hydrothermal fluid superposition transform type uranium deposit is main genetic type, ancient karst accumulate type is secondary genetic type, the later is formed by leaching the former and then precipitate, enrichment in ancient karst congeries, which is formed nearby faults and with the movement of Xishan structural movement. It is proven that metallogenic potential of Xidamingshan metallogenic belt is good. Tectonic rock controlled by subsidiary fracture nearby regional main fault, which connected with the Cambrian System and the Devonian System, and the deep of the deposit is guideline of mineral prospecting next stage. (authors)

  2. POTENTIAL AND FRECUENCY INFLUENCE ON THE MICROCAPSULES FORMATION BY COEXTRUSION AND GELLING

    Directory of Open Access Journals (Sweden)

    FERRÁNDIZ Marcela

    2015-05-01

    Full Text Available Wide varieties of techniques are currently available for encapsulation of active components in food, nutraceutical, pharmaceutical, cosmetics, textile, etc, industries. Coextrusion and gelling technique is a physical encapsulation technique used for the formation of core-shell liquid filled microcapsules. The general microcapsules morphologies are presented as core-shell spherical microcapsules. There are several parameters to control in the process, and their control is outstanding for the correct microcapsules morphology with proper encapsulation of the active ingredient, these parameters are: frequency, potential, nozzle diameters, encapsulating material concentration, cross-linking concentration, flow rates of encapsulation and active materials, etc. Furthermore shell and core solutions must have viscosity, interfacial tension, density, solubility and thermal properties that must be compatibles with the coextrusion process. The versatility of the systems allows for encapsulation of water- or - oil soluble liquids and slurries. This work is focused on encapsulated an essential oil, rosemary oil, by coextrusion and gelling, therefore is important study and optimize the process parameters, focusing on potential and frequency. A large numbers of experiments have been made in order to know the optimal values, the microcapsules morphology allow us which are the correct values. A stereomicroscope was used as know the microcapsules morphology and determination the correct values.

  3. Modified composites based on mesostructured iron oxyhydroxide and synthetic minerals: a potential material for the treatment of various toxic heavy metals and its toxicity.

    Science.gov (United States)

    Chung, Seung-Gun; Ryu, Jae-Chun; Song, Mi-Kyung; An, Byungryul; Kim, Song-Bae; Lee, Sang-Hyup; Choi, Jae-Woo

    2014-02-28

    The composites of mesostructured iron oxyhydroxide and/or commercial synthetic zeolite were investigated for use in the removal of toxic heavy metals, such as cadmium, copper, lead and arsenic, from aqueous solution. Four types of adsorbents, dried alginate beads (DABs), synthetic-zeolite impregnated beads (SZIBs), meso-iron-oxyhydroxide impregnated beads (MIOIBs) and synthetic-zeolite/meso-iron-oxyhydroxide composite beads (SZMIOIBs), were prepared for heavy metal adsorption tests. Laboratory experiments were conducted to investigate the removal efficiencies of cations and anions of heavy metals and the possibility of regenerating the adsorbents. Among these adsorbents, the MIOIBs can simultaneously remove cations and anions of heavy metals; they have high adsorption capacities for lead (60.1mgg(-1)) and arsenic (71.9mgg(-1)) compared with other adsorbents, such as DABs (158.1 and 0.0mgg(-1)), SZIB (42.9 and 0.0mgg(-1)) and SZMIOIB (54.0 and 5.9mgg(-1)) for lead and arsenic, respectively. Additionally, the removal efficiency was consistent at approximately 90%, notwithstanding repetitive regeneration. The characteristics of meso-iron-oxyhydroxide powder were confirmed by X-ray diffraction, Brunauer-Emmett-Teller and transmission electron microscopy. We also performed a comparative toxicity study that indicated that much lower concentrations of the powdered form of mesostructured iron oxyhydroxide had stronger cytotoxicity than the granular form. These results suggest that the granular form of meso iron oxyhydroxide is a more useful and safer adsorbent for heavy metal treatment than the powdered form. This research provides promising results for the application of MIOIBs as an adsorbent for various heavy metals from wastewater and sewage. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Formation of hydroxymethylfurfural in domestic high-fructose corn syrup and its toxicity to the honey bee (Apis mellifera).

    Science.gov (United States)

    LeBlanc, Blaise W; Eggleston, Gillian; Sammataro, Diana; Cornett, Charles; Dufault, Renee; Deeby, Thomas; St Cyr, Eldwin

    2009-08-26

    In the United States, high-fructose corn syrup (HFCS) has become a sucrose replacement for honey bees and has widespread use as a sweetener in many processed foods and beverages for human consumption. It is utilized by commercial beekeepers as a food for honey bees for several reasons: to promote brood production, after bees have been moved for commercial pollination, and when field-gathered nectar sources are scarce. Hydroxymethylfurfural (HMF) is a heat-formed contaminant and is the most noted toxin to honey bees. Currently, there are no rapid field tests that would alert beekeepers of dangerous levels of HMF in HFCS or honey. In this study, the initial levels and the rates of formation of HMF at four temperatures were evaluated in U.S.-available HFCS samples. Different HFCS brands were analyzed and compared for acidity and metal ions by inductively coupled plasma mass spectroscopy. Levels of HMF in eight HFCS products were evaluated over 35 days, and the data were fit to polynomial and exponential equations, with excellent correlations. The data can be used by beekeepers to predict HMF formation on storage. Caged bee studies were conducted to evaluate the HMF dose-response effect on bee mortality. Finally, commercial bases such as lime, potash, and caustic soda were added to neutralize hydronium ion in HMF samples, and the rates of HMF formation were compared at 45 degrees C.

  5. Assessment of potential radionuclide transport in site-specific geologic formations

    International Nuclear Information System (INIS)

    Dosch, R.G.

    1980-08-01

    Associated with the development of deep, geologic repositories for nuclear waste isolation is a need for safety assessments of the potential for nuclide migration. Frequently used in estimating migration rates is a parameter generally known as a distribution coefficient, K/sub d/, which describes the distribution of a radionuclide between a solid (rock) and a liquid (groundwater) phase. This report is intended to emphasize that the use of K/sub d/ must be coupled with a knowledge of the geology and release scenarios applicable to a repository. Selected K/sub d/ values involving rock samples from groundwater/brine simulants typical of two potential repository sites, WIPP and NTS, are used to illustrate this concern. Experimental parameters used in K/sub d/ measurements including nuclide concentration, site sampling/rock composition, and liquid-to-solid ratios are discussed. The solubility of U(VI) in WIPP brine/groundwater was addressed in order to assess the potential contribution of this phenomena to K/sub d/ values. Understanding mehanisms of sorption of radionuclides on rocks would lead to a better predictive capability. Sorption is attributed to the presence of trace constituents (often unidentified) in rocks. An attempt was made to determine if this applied to WIPP dolomite rocks by comparing sorption behavior of the natural material with that of a synthetic dolomite prepared in the laboratory with reagent grade chemicals. The results were inconclusive. The results of a study of Tc sorption by an argillite sample from the Calico Hills formation at NTS under ambient laboratory conditions were more conclusive. The Tc sorption was found to be associated with elemental carbon. Available evidence points to a reduction mechanism leading to the apparent sorption of Tc on the solid phase

  6. Primary Emission and the Potential of Secondary Aerosol Formation from Chinese Gasoline Engine Exhaust

    Science.gov (United States)

    Hu, Min; Peng, Jianfei; Qin, Yanhong; Du, Zhuofei; Li, Mengjin; Zheng, Rong; Zheng, Jing; Shang, Dongjie; Lu, Sihua; Wu, Yusheng; Zeng, Limin; Guo, Song; Shao, Min; Wang, Yinhui; Shuai, Shijin

    2017-04-01

    Along with the urbanization and economic growth, vehicle population in China reached 269 million, ranked the second in the world in 2015. Gasoline vehicle is identified to be the main source for urban PM2.5 in China, accounting for 15%-31%. In this study the impact of fuel components on PM2.5 and volatile organic compounds (VOCs) emissions from a gasoline port fuel injection (PFI) engine and a gasoline direct injection (GDI) engine are discussed. Results show that, higher proportion of aromatics, alkenes or sulfur in gasoline fuel will lead to higher PM emissions. The PM from the PFI engine mainly consists of OC and a small amount of EC and inorganic ions, while the PM discharge from the GDI engine mainly consists of EC, OM and a small amount of inorganic ions. Since the GDI engines can reduce fuel consumption and CO2 emissions, and it would become more and more popular in the near future. The characteristics of POM component, emission factors and source profile were investigated from GDI engine, particularly focused on the effect of engine speed, load and the catalyst, which will be very much helpful for source identification as source indicators. Chamber experiments were conducted to quantify the potential of secondary aerosol formation from exhaust of a PFI gasoline engine and China V gasoline fuel. During 4-5 h simulation, equivalent to10 days of atmospheric photo-oxidation in Beijing, the extreme SOA production was 426 ± 85 mg/kg fuel, with high precursors and OH exposure. 14% of SOA measured in the chamber experiments could be explained through the oxidation of speciated single-ring aromatics. Unspeciated precursors, such as intermediate-volatility organic compounds and semi-volatility organic compounds, might be significant for SOA formation from gasoline VOCs. We concluded that reduction of emissions of aerosol precursor gases from vehicles is essential to mediate pollution in China.

  7. Characterization of haloacetaldehyde and trihalomethane formation potentials during drinking water treatment.

    Science.gov (United States)

    Mao, Yu-Qin; Wang, Xiao-Mao; Guo, Xian-Fen; Yang, Hong-Wei; Xie, Yuefeng F

    2016-09-01

    Haloacetaldehydes (HAs) are the third prevalent group of disinfection by-products (DBPs) of great health concern. In this study, their formation and speciation during chlorination were investigated for raw and process waters collected at three O3-biological activated carbon (BAC) advanced drinking water treatment plants. The results showed that all HA formation potentials (HAFPs) were highly enhanced whenever ozone was applied before or after conventional treatment. Sand filtration and BAC filtration could substantially reduce HAFPs. Trihalomethanes (THMs) were also measured to better understand the role of HAs in DBPs. Very different from HAFPs, THMFPs kept decreasing with the progress of treatment steps, which was mainly attributed to the different precursors for HAs and THMs. Brominated HAs were detected in bromide-containing waters. Chloral hydrate (CH) contributed from 25% to 48% to the total HAs formed in waters containing 100-150 μg L(-1) bromide, indicating the wide existence of other HAs after chlorination besides CH production. In addition, bromide incorporation factor (BIF) in HAs and THMs increased with the progress of treatment steps and the BIF values of THMs were generally higher than those of HAs. The BAC filtration following ozonation could significantly reduce HA precursors produced from ozonation but without complete removal. The brominated HAFPs in the outflow of BAC were still higher than their levels in the raw water. As a result, O3-BAC combined treatment was effective at controlling the total HAs, whereas it should be cautious for waters with high bromide levels. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. The effect of potentially toxic elements and sewage sludge on the activity of regulatory enzyme glutamate kinase

    Czech Academy of Sciences Publication Activity Database

    Pavlíková, D.; Pavlík, Milan; Staszková, L.; Tlustoš, P.; Száková, J.; Balík, J.

    2007-01-01

    Roč. 53, č. 5 (2007), s. 201-206 ISSN 1214-1178 Institutional research plan: CEZ:AV0Z50380511 Keywords : Proline regulation * toxic elements * plant stress metabolism * chronic stress Subject RIV: ED - Physiology

  9. Specific and total N-nitrosamines formation potentials of nitrogenous micropollutants during chloramination.

    Science.gov (United States)

    Piazzoli, Andrea; Breider, Florian; Aquillon, Caroline Gachet; Antonelli, Manuela; von Gunten, Urs

    2018-05-15

    N-nitrosamines are a group of potent human carcinogens that can be formed during oxidative treatment of drinking water and wastewater. Many tertiary and quaternary amines present in consumer products (e.g., pharmaceuticals, personal care and household products) are known to be N-nitrosodimethylamine (NDMA) precursors during chloramination, but the formation of other N-nitrosamines has been rarely studied. This study investigates the specific and total N-nitrosamine (TONO) formation potential (FP) of various precursors from nitrogen-containing micropollutants (chlorhexidine, metformin, benzalkonium chloride and cetyltrimethylammonium chloride) and tertiary and quaternary model amines (trimethyl amine, N,N-dimethylbutyl amine, N,N-dimethylbenzyl amine and tetramethyl ammonium). All the studied nitrogenous micropollutants displayed quantifiable TONO FP, with molar yields in the range 0.04-11.92%. However, the observed TONO pools constituted mostly of uncharacterized species, not included in US-EPA 8270 N-nitrosamines standard mix. Only the quaternary ammonium compound benzalkonium chloride showed quantifiable NDMA FP (0.56% molar yield), however, explaining only a minor fraction of the observed TONO FP. The studied model amines showed molar NDMA yields from 0.10% (trimethyl amine) to 5.05% (N,N-dimethylbenzyl amine), very similar to the molar TONO yields. The comparison of the FPs of micropollutants and model compounds showed that the presence of electron donating functional groups (such as a benzyl group) in tertiary and quaternary amine precursors leads to a higher formation of NDMA and uncharacterized N-nitrosamines, respectively. LC-qTOF screening of a list of proposed N-nitrosamine structures has enabled to identify a novel N-nitrosamine (N-nitroso-N-methyldodecylamine) from the chloramination of benzalkonium chloride. This finding supports the hypothesis that different functional groups in quaternary amines can act as leaving groups during chloramination and

  10. Conditions for the formation and atmospheric dispersion of a toxic, heavy gas layer during thermal metamorphism of coal and evaporite deposits by sill intrusion

    Science.gov (United States)

    Storey, Michael; Hankin, Robin K. S.

    2010-05-01

    There is compelling evidence for massive discharge of volatiles, including toxic species, into the atmosphere at the end of the Permian. It has been argued that most of the gases were produced during thermal metamorphism of coal and evaporite deposits in the East Siberia Tunguska basin following sill intrusion (Retallack and Jahren, 2008; Svensen et al., 2009). The release of the volatiles has been proposed as a major cause of environmental and extinction events at the end of the Permian, with venting of carbon gases and halocarbons to the atmosphere leading to global warming and atmospheric ozone depletion (Svensen et al., 2009) Here we consider the conditions required for the formation and dispersion of toxic, heavier than air, gas plumes, made up of a mixture of CO2, CH4, H2S and SO2 and formed during the thermal metamorphism of C- and S- rich sediments. Dispersion models and density considerations within a range of CO2/CH4 ratios and volatile fluxes and temperatures, for gas discharge by both seepage and from vents, allow the possibility that following sill emplacement much of the vast East Siberia Tunguska basin was - at least intermittently - covered by a heavy, toxic gas layer that was unfavorable for life. Dispersion scenarios for a heavy gas layer beyond the Siberian region during end-Permian times will be presented. REFERENCES G. J. Retallack and A. H. Jahren, Methane release from igneous intrusion of coal during Late Permian extinction events, Journal of Geology, volume 116, 1-20, 2008 H. Svensen et al., Siberian gas venting and the end-Permian environmental crisis, Earth and Planetary Science Letters, volume 277, 490-500, 2009

  11. Modified composites based on mesostructured iron oxyhydroxide and synthetic minerals: A potential material for the treatment of various toxic heavy metals and its toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Seung-Gun [Center for Water Resource Cycle Research, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Ryu, Jae-Chun; Song, Mi-Kyung [Center for Integrated Risk Research, Cellular and Molecular Toxicology Laboratory, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); An, Byungryul [Center for Water Resource Cycle Research, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Kim, Song-Bae [Environmental Functional Materials and Biocolloids Laboratory, Seoul National University, Seoul 151-921 (Korea, Republic of); Lee, Sang-Hyup [Center for Water Resource Cycle Research, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Graduate School of Convergence Green Technology and Policy, Korea University, Seoul 136-701 (Korea, Republic of); Choi, Jae-Woo, E-mail: plead36@kist.re.kr [Center for Water Resource Cycle Research, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

    2014-02-01

    Graphical abstract: - Highlights: • Meso-iron-oxyhydroxide was found to be efficient for anion heavy metal adsorption. • The composite bead can simultaneously remove the cations and anions of heavy metals. • Powdered form had stronger cytotoxicity than did the granular form. • Adsorbent recovery is facilitated by granulation process of powder-type. - Abstract: The composites of mesostructured iron oxyhydroxide and/or commercial synthetic zeolite were investigated for use in the removal of toxic heavy metals, such as cadmium, copper, lead and arsenic, from aqueous solution. Four types of adsorbents, dried alginate beads (DABs), synthetic-zeolite impregnated beads (SZIBs), meso-iron-oxyhydroxide impregnated beads (MIOIBs) and synthetic-zeolite/meso-iron-oxyhydroxide composite beads (SZMIOIBs), were prepared for heavy metal adsorption tests. Laboratory experiments were conducted to investigate the removal efficiencies of cations and anions of heavy metals and the possibility of regenerating the adsorbents. Among these adsorbents, the MIOIBs can simultaneously remove cations and anions of heavy metals; they have high adsorption capacities for lead (60.1 mg g{sup −1}) and arsenic (71.9 mg g{sup −1}) compared with other adsorbents, such as DABs (158.1 and 0.0 mg g{sup −1}), SZIB (42.9 and 0.0 mg g{sup −1}) and SZMIOIB (54.0 and 5.9 mg g{sup −1}) for lead and arsenic, respectively. Additionally, the removal efficiency was consistent at approximately 90%, notwithstanding repetitive regeneration. The characteristics of meso-iron-oxyhydroxide powder were confirmed by X-ray diffraction, Brunauer–Emmett–Teller and transmission electron microscopy. We also performed a comparative toxicity study that indicated that much lower concentrations of the powdered form of mesostructured iron oxyhydroxide had stronger cytotoxicity than the granular form. These results suggest that the granular form of meso iron oxyhydroxide is a more useful and safer adsorbent for

  12. Estimation of daily intake of potentially toxic elements from urban street dust and the role of oral bioaccessibility testing.

    Science.gov (United States)

    Okorie, Alexander; Entwistle, Jane; Dean, John R

    2012-02-01

    The pseudo-total and oral bioaccessible concentration of six potentially toxic elements (PTEs) in urban street dust was investigated. Typical pseudo-total concentrations across the sampling sites ranged from 4.4 to 8.6 mg kg(-1) for As, 0.2-3.6 mg kg(-1) for Cd, 25-217 mg kg(-1) for Cu, 14-46 mg kg(-1) for Ni, 70-4261 mg kg(-1) for Pb, and, 111-652 mg kg(-1) for Zn. This data compared favourably with other urban street dust samples collected and analysed in a variety of cities globally; the exception was the high level of Pb determined in a specific sample in this study. The oral bioaccessibility of PTEs in street dust is also assessed using in vitro gastrointestinal extraction (Unified Bioaccessibility Method, UBM). Based on a worst case scenario the oral bioaccessibility data estimated that Cd and Zn had the highest % bioaccessible fractions (median >45%) while the other PTEs i.e. As, Cu, Ni and Pb had lower % bioaccessible fractions (median <35%). The pseudo-total and bioaccessible concentrations of PTEs in the samples has been compared to estimated tolerable daily intake values based on unintentional soil/dust consumption. Cadmium, Cu and Ni are well within the oral tolerable daily intake rates. With respect to As and Pb, only the latter exceeds the TDI(oral) if we model ingestion rate based on atmospheric 'dustiness' rather than the US EPA (2008) unintentional soil/dust consumption rate of 100 mg d(-1). We consider it unlikely that even a child with pica tendencies would ingest as much as 100mg soil/dust during a daily visit to the city centre, and in particular to the sites with elevated Pb concentrations observed in this study. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Sustainable Soil Washing: Shredded Card Filtration of Potentially Toxic Elements after Leaching from Soil Using Organic Acid Solutions

    Science.gov (United States)

    Ash, Christopher; Drábek, Ondřej; Tejnecký, Václav; Jehlička, Jan; Michon, Ninon; Borůvka, Luboš

    2016-01-01

    Shredded card (SC) was assessed for use as a sorbent of potentially toxic elements (PTE) carried from contaminated soil in various leachates (oxalic acid, formic acid, CaCl2, water). We further assessed SC for retention of PTE, using acidified water (pH 3.4). Vertical columns and a peristaltic pump were used to leach PTE from soils (O and A/B horizons) before passing through SC. Sorption onto SC was studied by comparing leachates, and by monitoring total PTE contents on SC before and after leaching. SC buffers against acidic soil conditions that promote metals solubility; considerable increases in solution pH (+4.49) were observed. Greatest differences in solution PTE content after leaching with/without SC occurred for Pb. In oxalic acid, As, Cd, Pb showed a high level of sorption (25, 15, and 58x more of the respective PTE in leachates without SC). In formic acid, Pb sorption was highly efficient (219x more Pb in leachate without SC). In water, only Pb showed high sorption (191x more Pb in leachate without SC). In desorption experiments, release of PTE from SC varied according to the source of PTE (organic/mineral soil), and type of solvent used. Arsenic was the PTE most readily leached in desorption experiments. Low As sorption from water was followed by fast release (70% As released from SC). A high rate of Cd sorption from organic acid solutions was followed by strong retention (~12% Cd desorption). SC also retained Pb after sorption from water, with subsequent losses of ≤8.5% of total bound Pb. The proposed use of this material is for the filtration of PTE from extract solution following soil washing. Low-molecular-mass organic acids offer a less destructive, biodegradable alternative to strong inorganic acids for soil washing. PMID:26900684

  14. Sustainable Soil Washing: Shredded Card Filtration of Potentially Toxic Elements after Leaching from Soil Using Organic Acid Solutions.

    Directory of Open Access Journals (Sweden)

    Christopher Ash

    Full Text Available Shredded card (SC was assessed for use as a sorbent of potentially toxic elements (PTE carried from contaminated soil in various leachates (oxalic acid, formic acid, CaCl2, water. We further assessed SC for retention of PTE, using acidified water (pH 3.4. Vertical columns and a peristaltic pump were used to leach PTE from soils (O and A/B horizons before passing through SC. Sorption onto SC was studied by comparing leachates, and by monitoring total PTE contents on SC before and after leaching. SC buffers against acidic soil conditions that promote metals solubility; considerable increases in solution pH (+4.49 were observed. Greatest differences in solution PTE content after leaching with/without SC occurred for Pb. In oxalic acid, As, Cd, Pb showed a high level of sorption (25, 15, and 58x more of the respective PTE in leachates without SC. In formic acid, Pb sorption was highly efficient (219x more Pb in leachate without SC. In water, only Pb showed high sorption (191x more Pb in leachate without SC. In desorption experiments, release of PTE from SC varied according to the source of PTE (organic/mineral soil, and type of solvent used. Arsenic was the PTE most readily leached in desorption experiments. Low As sorption from water was followed by fast release (70% As released from SC. A high rate of Cd sorption from organic acid solutions was followed by strong retention (~12% Cd desorption. SC also retained Pb after sorption from water, with subsequent losses of ≤8.5% of total bound Pb. The proposed use of this material is for the filtration of PTE from extract solution following soil washing. Low-molecular-mass organic acids offer a less destructive, biodegradable alternative to strong inorganic acids for soil washing.

  15. Comparative ovarian microarray analysis of juvenile hormone-responsive genes in water flea Daphnia magna: potential targets for toxicity.

    Science.gov (United States)

    Toyota, Kenji; Williams, Timothy D; Sato, Tomomi; Tatarazako, Norihisa; Iguchi, Taisen

    2017-03-01

    The freshwater zooplankton Daphnia magna has been extensively employed in chemical toxicity tests such as OECD Test Guidelines 202 and 211. Previously, it has been demonstrated that the treatment of juvenile hormones (JHs) or their analogues to female daphnids can induce male offspring production. Based on this finding, a rapid screening method for detection of chemicals with JH-activity was recently developed using adult D. magna. This screening system determines whether a chemical has JH-activity by investigating the male offspring inducibility. Although this is an efficient high-throughput short-term screening system, much remains to be discovered about JH-responsive pathways in the ovary, and whether different JH-activators act via the same mechanism. JH-responsive genes in the ovary including developing oocytes are still largely undescribed. Here, we conducted comparative microarray analyses using ovaries from Daphnia magna treated with fenoxycarb (Fx; artificial JH agonist) or methyl farnesoate (MF; a putative innate JH in daphnids) to elucidate responses to JH agonists in the ovary, including developing oocytes, at a JH-sensitive period for male sex determination. We demonstrate that induction of hemoglobin genes is a well-conserved response to JH even in the ovary, and a potential adverse effect of JH agonist is suppression of vitellogenin gene expression, that might cause reduction of offspring number. This is the first report demonstrating different transcriptomics profiles from MF and an artificial JH agonist in D. magna ovary, improving understanding the tissue-specific mode-of-action of JH. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Harmful potential toxic elements in greenhouse soils under long-term cultivation in Almería (Spain)

    Science.gov (United States)

    Joaquin Ramos-Miras, Jose; Rodríguez Martín, Jose Antonio; Boluda, Rafael; Bech, Jaume; Gil, Carlos

    2014-05-01

    Heavy metals (HM) are considered highly significant environmental contaminants and are the object of many scientific research works into the soil environment. Activities like agriculture or industry can increase the concentration of these contaminants in soils and waters, which can affect the food chain. Intensification of certain agricultural practices, constant and excessive use of fertilizers and phytosanitary products, and using machinery, increase the HM content in agricultural soils. Many studies have dealt with HM accumulation over time. Despite these works, the influence of long periods of time on these contents, the dynamics and evolution of these elements in agricultural soils, especially soils used for intensive farming purposes under greenhouse conditions, remain unknown to a certain extent. The western Almería region (Spain) is a very important area from both the socio-economic and agricultural viewpoints. A common practice in greenhouse agriculture is the addition of agrochemicals to soils and crops to improve nutrient supply or crop protection and disease control. Such intense agricultural activity has a strong impact, which may have negative repercussions on both these greenhouse soils and the environment. A research has been carried out to determine the total and available levels of six harmful potentially toxic elements (Cd, Cu, Pb, Ni, Zn and Co), and to assess long-term variations in the greenhouse soils of western Almeria. The results indicate that managing soils in the greenhouse preparation stage determines major changes in total and available HM contents. Furthermore, Cd, Cu and Pb enrichment in soil was observed depending on the element and years of growth.

  17. Mechanism of Formation of the Resource Potential of the Management and Organisation Enterprise Development: Strategic and Tactical Aspects

    Directory of Open Access Journals (Sweden)

    Slastianykova Anzhelika I.

    2014-02-01

    Full Text Available The article considers influence of factors – reasons of origination of crisis phenomena – upon resource potential with the aim of study of management and organisation enterprise development. It identifies that correlation of managed and unmanaged processes at an enterprise is achieved only through correct selection of tactical and strategic orientation, which should take into account specific features of various types of crises, and also the process of their deployment and ways of prevention and elimination. The article generalises influence of factors – reasons of origination of crisis phenomena – upon resource potential with the aim of study of the management and organisation development of an enterprise and building a mechanism. It improves a mechanism of formation of the resource potential of the management and organisation development of an enterprise at tactical and strategic levels. It allowed finding out that managerial impact on formation and maintenance of key factors influences the formation, management and application of the enterprise resource potential.

  18. Pulmonary heat shock protein expression after exposure to a metabolically activated Clara cell toxicant: relationship to protein adduct formation

    International Nuclear Information System (INIS)

    Williams, Kurt J.; Cruikshank, Michael K.; Plopper, Charles G.

    2003-01-01

    Heat shock proteins/stress proteins (Hsps) participate in regulation of protein synthesis and degradation and serve as general cytoprotectants, yet their role in lethal Clara cell injury is not clear. To define the pattern of Hsp expression in acute lethal Clara cell injury, mice were treated with the Clara cell-specific toxicant naphthalene (NA), and patterns of expression compared to electrophilic protein adduction and previously established organellar degradation and gluathione (GSH) depletion. In sites of lethal injury (distal bronchiole), prior to organellar degradation (1 h post-NA), protein adduction is detectable and ubiquitin, Hsp 25, Hsp 72, and heme-oxygenase 1 (HO-1) are increased. Maximal Hsp expression, protein adduction, and GSH depletion occur simultaneous (by 2-3 h) with early organelle disruption. Hsp expression is higher later (6-24 h), only in exfoliating cells. In airway sites (proximal bronchiole) with nonlethal Clara cell injury elevation of Hsp 25, 72, and HO-1 expression follows significant GSH depletion (greater than 50% 2 h post-NA). This data build upon our previous studies and we conclude that (1) in lethal (terminal bronchiole) and nonlethal (proximal bronchiole) Clara cell injury, Hsp induction is associated with the loss of GSH and increased protein adduction, and (2) in these same sites, organelle disruption is not a prerequisite for Hsp induction

  19. Assessment of the behavior of potentially toxic elements (PTEs) in soil from the Sarno River Basin through a compositional data analysis

    Science.gov (United States)

    Matar, Thiombane; Vivo Benedetto, De; Albanese, Stefano; Martín-Fernández, Josep-Antoni; Lima, Annamaria; Doherty, Angela

    2017-04-01

    The Sarno River Basin (south-west Italy), nestled between the Somma-Vesuvius volcanic complex and the limestone formations of the Campania-Apennine Chain, is one of the most polluted river basins in Europe due to a high rate of industrialization and intensive agriculture. Water from the Sarno River, which is heavily contaminated by the discharge of human and industrial waste, is partially used for irrigation on the agricultural fields surrounding it. We apply compositional data analysis on 319 samples collected during two field campaigns along the river course, and throughout the basin, to determine the level and potential origin (anthropogenic and/or geogenic) of the potentially toxic elements (PTEs). The concentrations of 53 elements determined by ICP-MS, and were subsequently log-transformed. Using a clr-biplot and principal factor analysis, the variability and the correlations between a subset of extracted variables (26 elements) were identified. Using both normalized raw data and clr-transformed coordinates, factor association interpolated maps were generated to better visualize the distribution and potential sources of the PTEs in the Sarno Basin. The underlying geology substrata appear to be associated with raised of levels of Na, K, P, Rb, Ba, V, Co, B, Zr, and Li, due to the presence of pyroclastic rocks from Mt. Somma-Vesuvius. Similarly, elevated Pb, Zn, Cd, and Hg concentrations are most likely related to both geological and anthropogenic sources, the underlying volcanic rocks and contamination from fossil fuel combustion associated with urban centers. Interpolated factors score maps and clr-biplot indicate a clear correlation between Ni and Cr in samples taken along the Sarno River, and Ca and Mg near the Solofra district. After considering nearby anthropogenic sources, the Ni and Cr are PTEs from the Solofra tannery industry, while Ca and Mg correlate to the underlying limestone-rich soils of the area. This study shows the applicability of the

  20. Biofabrication of zinc oxide nanoparticles using fruit extract of Rosa canina and their toxic potential against bacteria: A mechanistic approach

    Energy Technology Data Exchange (ETDEWEB)

    Jafarirad, Saeed; Mehrabi, Meysam [Research Institute for Fundamental Sciences (RIFS), University of Tabriz, Tabriz (Iran, Islamic Republic of); Divband, Baharak [Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Inorganic Chemistry Department, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of); Kosari-Nasab, Morteza [Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of)

    2016-02-01

    The use of plant extract in the biosynthesis of nanoparticles (NPs) can be an eco-friendly approach and have been suggested as a possible alternative to classic methods namely physical and chemical procedures. In this study, the biosynthesis of zinc oxide (ZnO) NPs by both “conventional heating” (CH) and “microwave irradiation” (MI) methods has been reported. Stable and spherical ZnONPs were produced using zinc nitrate and flesh extract of Rosa canina fruit (rosehip) which was used as a precursor. The flesh extract acts as a reducing and capping agent for generation of ZnONPs. The structural, morphological and colloidal properties of the as-synthesized NPs have been confirmed by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), Fourier transform Infrared (FT-IR) and Dynamic Light Scattering (DLS). In comparison with the CH method, the MI method has some advantages such as significantly short reaction time (within 8 min) owing to the high heating rate and thus the accelerated reaction rate. Both methods led to the synthesis of nearly identical NPs with respect to shape and size according to the results of DLS, XRD and SEM techniques. The possible mechanism for synthesis pathway has been proposed based on FT IR results, XRD patterns, potentiometric data and antioxidant activity. In addition, the antibacterial activity of as-prepared ZnONPs was investigated against several bacteria such as Listeria monocytogenes, Escherichia coli, Salmonella typhimurium. Moreover, the efficacy of ZnONPs to treat cancer cell lines were measured by means of cell viability test via MTT assay in which concentrations of 0.05 and 0.1 mg/mL of ZnONPs induced a very low toxicity. Thus, the present investigation reveals that ZnONPs have the potential for various medical and industrial applications. - Highlights: • We report a green producing route from biomaterials to potentially biomedical applications. • We comprise two methods in respect

  1. Formation mechanism of self-potential at ISL-amenable interlayer oxidation zone sandstone-type uranium deposit and the simulation and application of self-potential anomalies

    International Nuclear Information System (INIS)

    Tang Hongzhi; Liu Qingcheng; Su Zhaofeng; Gong Yuling

    2006-01-01

    Based on the analysis of geochemical characteristics and metallogenic physico-chemical conditions of ISL-amenable sandstone-type uranium deposits, the formation mechanism of self-potential field is discussed, a mathematic calculation model has been set up, and the simulation calculation has been performed for self-potential anomalies above uranium ore bodies of ordinary form, features of survey curve are analysed and methods for correcting topography at self-potential anomalies are discussed, and a simulation curve of self-potential in the area of slope topography has been presented. Finally, the availability of the method is demonstrated by an example. (authors)

  2. Potential of the Biotic Ligand Model (BLM) to Predict Copper Toxicity in the White-Water of the Solimões-Amazon River.

    Science.gov (United States)

    Pont, Giorgi Dal; Domingos, Fabíola Xochilt Valdez; Fernandes-de-Castilho, Marisa; Val, Adalberto Luis

    2017-01-01

    In this study, we evaluated the capacity of the Biotic Ligand Model (BLM) to predict copper toxicity in white-waters of the Solimões-Amazon River. LC 50 tests using the species Otocinclus vittatus (Regan, 1904) were performed with Solimões-Amazon river water (100%) at 20%, 40%, 60%, and 80% dilutions. A sevenfold decrease in both dissolved and total Cu toxicity was observed in the experiment conducted with 100% when compared to 20% white-water, indicating that physicochemical characteristics of white-water attenuate Cu toxicity. There was agreement between the observed LC 50 and the LC 50 predicted by the BLM after the adjustment of critical accumulation concentration (LA 50 ) for O. vittatus. BLM modeling indicated that dissolved organic carbon (DOC) and pH were the most important water parameters influencing Cu toxicity, followed by Ca 2+ . Our results highlight the first evidence that the BLM presents potential to predict Cu toxicity to aquatic organisms in the white-water of the Solimões-Amazon River.

  3. Serum metabolomics reveals betaine and phosphatidylcholine as potential biomarkers for the toxic responses of processed Aconitum carmichaelii Debx.

    Science.gov (United States)

    Tan, Yong; Ko, Joshua; Liu, Xinru; Lu, Cheng; Li, Jian; Xiao, Cheng; Li, Li; Niu, Xuyan; Jiang, Miao; He, Xiaojuan; Zhao, Hongyan; Zhang, Zhongxiao; Bian, Zhaoxiang; Yang, Zhijun; Zhang, Ge; Zhang, Weidong; Lu, Aiping

    2014-07-29

    We recently reported that processed Aconitum carmichaelii Debx (Bai-Fu-Pian in Chinese, BFP) elicits differential toxic responses in rats under various health conditions. The present study aimed to determine the graded toxicity of BFP so as to derive a safe therapeutic rationale in clinical practice. Sensitive and reliable biomarkers of toxicity were also identified, with the corresponding metabolic pathways being unveiled. Thirty male Sprague-Dawley rats were divided into five groups (n = 6) and received oral administration of BFP extract (0.32, 0.64, 1.28 or 2.56 g kg(-1) per day) or an equal volume of drinking water (control) for 15 days. The metabolomic profiles of rat serum were analyzed by liquid chromatography quadruple time-of-flight mass spectrometry (LC-Q-TOF-MS). Linear regression analysis and Ingenuity Pathway Analysis (IPA) were used to elucidate the differentiated altered metabolites and associated network relationships. Results from biochemical and histopathological examinations revealed that BFP could induce prominent toxicity in the heart, liver and kidneys at a dose of 2.56 g kg(-1) per day. Betaine up-regulation and phosphatidylcholine down-regulation were detected in the serum samples of drug-treated groups in a dose-dependent manner. In summary, betaine and phosphatidylcholine could be regarded as sensitive biomarkers for the toxic responses of BFP. Perturbations of RhoA signaling, choline metabolism and free radical scavenging were found to be partly responsible for the toxic effects of the herbal drug. Based on the metabolomics findings, we could establish a safe therapeutic range in the clinical use of BFP, with promising predictions of possible drug toxicity.

  4. Mast cell chymase potentiates histamine-induced wheal formation in the skin of ragweed-allergic dogs.

    OpenAIRE

    Rubinstein, I; Nadel, J A; Graf, P D; Caughey, G H

    1990-01-01

    Skin mast cells release the neutral protease chymase along with histamine during degranulation. To test the hypothesis that chymase modulates histamine-induced plasma extravasation, we measured wheal formation following intradermal injection of purified mast cell chymase and histamine into the skin of ragweed-allergic dogs. We found that chymase greatly augments histamine-induced wheal formation. The magnitude of the potentiating effect increases with increasing doses of chymase and becomes m...

  5. Evaluation of the toxic potential of aspartame in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9

    Energy Technology Data Exchange (ETDEWEB)

    Siddique, Y.H.; Anjum, S.; Rahul x, Smita Jyoti

    2017-07-01

    Aspartame is commonly used as a sweetener in prepared foods, beverages and in recipes. In the present study the possible toxic effects of aspartame were studied in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9. The third instar larvae were allowed to feed on the diet having different doses of aspartame. The results obtained in the present study suggest that the exposure of third instar larvae to the diet having 20, 40, 80, 160 and 320 mM of aspartame did not show any significant the toxic effects after 24 hours of the exposure compared to control (p<0.05). The results for pupae formation and emergence of flies also did not show any significant difference compared to control (p<0.05).

  6. Evaluation of the toxic potential of aspartame in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ Bg9

    Directory of Open Access Journals (Sweden)

    YASIR HASAN SIDDIQUE

    2017-07-01

    Full Text Available Aspartame is commonly used as a sweetener in prepared foods, beverages and in recipes. In the present study the possible toxic effects of aspartame were studied in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ Bg9. The third instar larvae were allowed to feed on the diet having different doses of aspartame. The results obtained in the present study suggest that the exposure of third instar larvae to the diet having 20, 40, 80, 160 and 320 mM of aspartame did not show any significant the toxic effects after 24 hours of the exposure compared to control (p<0.05. The results for pupae formation and emergence of flies also did not show any significant difference compared to control (p<0.05.

  7. Evaluation of the toxic potential of aspartame in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9

    International Nuclear Information System (INIS)

    Siddique, Y.H.; Anjum, S.; Rahul x, Smita Jyoti

    2017-01-01

    Aspartame is commonly used as a sweetener in prepared foods, beverages and in recipes. In the present study the possible toxic effects of aspartame were studied in third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ) Bg9. The third instar larvae were allowed to feed on the diet having different doses of aspartame. The results obtained in the present study suggest that the exposure of third instar larvae to the diet having 20, 40, 80, 160 and 320 mM of aspartame did not show any significant the toxic effects after 24 hours of the exposure compared to control (p<0.05). The results for pupae formation and emergence of flies also did not show any significant difference compared to control (p<0.05).

  8. Evaluation of the Potential Risk of Drugs to Induce Hepatotoxicity in Human—Relationships between Hepatic Steatosis Observed in Non-Clinical Toxicity Study and Hepatotoxicity in Humans-

    Science.gov (United States)

    Goda, Keisuke; Kobayashi, Akio; Takahashi, Akemi; Takahashi, Tadakazu; Saito, Kosuke; Maekawa, Keiko; Saito, Yoshiro; Sugai, Shoichiro

    2017-01-01

    In the development of drugs, we sometimes encounter fatty change of the hepatocytes (steatosis) which is not accompanied by degenerative change in the liver in non-clinical toxicity studies. In this study, we investigated the relationships between fatty change of the hepatocytes noted in non-clinical toxicity studies of compound X, a candidate compound in drug development, and mitochondrial dysfunction in order to estimate the potential risk of the compound to induce drug-induced liver injury (DILI) in humans. We conducted in vivo and in vitro exploratory studies for this purpose. In vivo lipidomics analysis was conducted to investigate the relationships between alteration of the hepatic lipids and mitochondrial dysfunction. In the liver of rats treated with compound X, triglycerides containing long-chain fatty acids, which are the main energy source of the mitochondria, accumulated. Accumulation of these triglycerides was considered to be related to the inhibition of mitochondrial respiration based on the results of in vitro mitochondria toxicity studies. In conclusion, fatty change of the hepatocytes (steatosis) in non-clinical toxicity studies of drug candidates can be regarded as a critical finding for the estimation of their potential risk to induce DILI in humans when the fatty change is induced by mitochondrial dysfunction. PMID:28417920

  9. Elimination of Whole Effluent Toxicity NPDES Permit Limits through the Use of an Alternative Testing Species and Reasonable Potential Analysis

    International Nuclear Information System (INIS)

    PAYNE, W.L.

    2004-01-01

    The cladoceran, Ceriodaphnia dubia (C. dubia), is required by the State of South Carolina to be used in whole effluent toxicity (WET) compliance tests in order to meet limits contained within National Pollutant Discharge Elimination System (NPDES) permits. Westinghouse Savannah River Company (WSRC) experienced WET test failures for no clear reason over a long period of time. Toxicity identification examinations on effluents did not indicate the presence of toxicants; therefore, the WET test itself was brought under suspicion. Research was undertaken with an alternate cladoceran, Daphnia ambigua (D. ambigua). It was determined that this species survives better in soft water, so approval was obtained from regulating authorities to use this ''alternate'' species in WET tests. The result was better test results and elimination of non-compliances. The successful use of D. ambigua allowed WSRC to gain approval from the South Carolina Department of Health and Environmental Control (SCDHEC) to remove WET limits from the NPDES permit

  10. Vertical distribution of potentially toxic elements in sediments impacted by intertidal geothermal hot springs (Bahia Concepcion, Gulf of California)

    Science.gov (United States)

    Leal-Acosta, M. L.; Shumilin, E.

    2016-12-01

    The intertidal geothermal hot springs (GHS) in Bahia Concepcion, Gulf of California are the source of potentially toxic elements to the adjacent marine environment surrounded by mangroves trees. The anoxic sediments enriched in organic carbon accumulate As, Hg and other heavy metals that can be bioavailable for the biota. To know the vertical distribution of these elements the geochemistry of a short sediment core was carried out. It was collected in June, 2010 in the mangrove area near to GHS (1 m) during a low tide, pushing manually a polypropylene tube into the sediments. The extracted sediment core was cut with plastic knife on 1 cm thick sub-samples, stored in plastic bags and transported on ice to the laboratory. The major and trace elements contents were determinate by ICP-MS after total digestion with stronger acids (HClO4-HNO3-HCl-HF). Certificate reference materials were used for the quality control of the method obtaining good recoveries for most of the elements (80-105%). The sediment core had high maximum contents of CaCO3 (70%) and total organic carbon (12%). The concentration of Hg along the core ranges from 650 to 74300 mg kg-1 and had more than three orders of magnitude above the reference values of 40 mg kg-1 for the Upper Continental Crust (UCC)1. In contrast, As ranges from 12 to 258 mg kg-1 resulting in more than one order of magnitude respect to UCC1 (1.7 mg kg-1). Similar pattern result for Mn, Cu, Pb, and Zn with the maximum values of 3200 mg kg-1, 42 mg kg-1, 12.4 mg kg-1, 71 mg kg-1 respectively that coincide with the maximum for As at the same core depth (4 cm). The Ca, Li, Co, Sb, U, and Mg also show high contents in comparison with the UCC1reference values. The maximum contents of Mo and Cd coincide with maximum concentration of sulfur (2%) at 6 to 8 cm. The enrichment factor calculated using Al as normalizing element showed Cd (7-280), As (26-329) and Hg (23-1196) as highly enriched mainly in the first centimeters of the sediment core

  11. Abscess formation and alpha-hemolysin induced toxicity in a mouse model of Staphylococcus aureus peritoneal infection.

    Science.gov (United States)

    Rauch, Sabine; DeDent, Andrea C; Kim, Hwan Keun; Bubeck Wardenburg, Juliane; Missiakas, Dominique M; Schneewind, Olaf

    2012-10-01

    Staphylococcus aureus is a frequent cause of skin infection and sepsis in humans. Preclinical vaccine studies with S. aureus have used a mouse model with intraperitoneal challenge and survival determination as a measure for efficacy. To appreciate the selection of protective antigens in this model, we sought to characterize the pathological attributes of S. aureus infection in the peritoneal cavity. Testing C57BL/6J and BALB/c mice, >10(9) CFU of S. aureus Newman were needed to produce a lethal outcome in 90% of animals infected via intraperitoneal injection. Both necropsy and histopathology revealed the presence of intraperitoneal abscesses in the vicinity of inoculation sites. Abscesses were comprised of fibrin as well as collagen deposits and immune cells with staphylococci replicating at the center of these lesions. Animals that succumbed to challenge harbored staphylococci in abscess lesions and in blood. The establishment of lethal infections, but not the development of intraperitoneal abscesses, was dependent on S. aureus expression of alpha-hemolysin (Hla). Active immunization with nontoxigenic Hla(H35L) or passive immunization with neutralizing monoclonal antibodies protected mice against early lethal events associated with intraperitoneal S. aureus infection but did not affect the establishment of abscess lesions. These results characterize a mouse model for the study of intraperitoneal abscess formation by S. aureus, a disease that occurs frequently in humans undergoing continuous ambulatory peritoneal dialysis for end-stage renal disease.

  12. Cyanea capillata tentacle-only extract as a potential alternative of nematocyst venom: its cardiovascular toxicity and tolerance to isolation and purification procedures.

    Science.gov (United States)

    Xiao, Liang; He, Qian; Guo, Yufeng; Zhang, Jing; Nie, Fei; Li, Yue; Ye, Xiaofei; Zhang, Liming

    2009-01-01

    As the proteins with cardiovascular toxicity in jellyfish nematocyst venom and tentacle-only extract (TOE) are probably encoded by the same gene, TOE provides a potential alternative of nematocyst venom with much richer source for acquisition of such proteins. In this study, Cyanea capillata nematocyst venom and TOE (5mg/kg) both exhibited cardiovascular toxicity in rats, and TOE caused blood pressure reduction in slightly greater amplitude than nematocyst venom 3min after intravenous administration. SDS-PAGE suggested high likeliness that they both contained the same bioactive protein. The activity of TOE was dose-dependent within 1.25-5mg/kg, but not at higher concentrations. The cardiovascular activity of TOE sustained a major loss after exposure to 60 degrees C, and was totally abolished after exposure to 80 degrees C. Within the pH range of 7-11, the activity of TOE was well preserved, and rapidly attenuated in pH below 5. At 4 degrees C, TOE lost cardiovascular toxicity after preservation for 7 days, which occurred only after an 8-h preservation at 20 degrees C. Repeated freeze-thawing and freeze-drying did not significantly affect the toxicity of TOE. Buffer solutions obviously affected the toxicity of TOE, and 0.02mol/L HAc (pH 6.0) was optimal. These results provide experimental data for optimizing the conditions for isolating the proteins with cardiovascular toxicity from jellyfish TOE, which serves as a promising alternative source of nematocyst venom.

  13. Assessment of the Potential Role of Streptomyces in Cave Moonmilk Formation

    Directory of Open Access Journals (Sweden)

    Marta Maciejewska

    2017-06-01

    Full Text Available Moonmilk is a karstic speleothem mainly composed of fine calcium carbonate crystals (CaCO3 with different textures ranging from pasty to hard, in which the contribution of biotic rock-building processes is presumed to involve indigenous microorganisms. The real microbial input in the genesis of moonmilk is difficult to assess leading to controversial hypotheses explaining the origins and the mechanisms (biotic vs. abiotic involved. In this work, we undertook a comprehensive approach in order to assess the potential role of filamentous bacteria, particularly a collection of moonmilk-originating Streptomyces, in the genesis of this speleothem. Scanning electron microscopy (SEM confirmed that indigenous filamentous bacteria could indeed participate in moonmilk development by serving as nucleation sites for CaCO3 deposition. The metabolic activities involved in CaCO3 transformation were furthermore assessed in vitro among the collection of moonmilk Streptomyces, which revealed that peptides/amino acids ammonification, and to a lesser extend ureolysis, could be privileged metabolic pathways participating in carbonate precipitation by increasing the pH of the bacterial environment. Additionally, in silico search for the genes involved in biomineralization processes including ureolysis, dissimilatory nitrate reduction to ammonia, active calcium ion transport, and reversible hydration of CO2 allowed to identify genetic predispositions for carbonate precipitation in Streptomyces. Finally, their biomineralization abilities were confirmed by environmental SEM, which allowed to visualize the formation of abundant mineral deposits under laboratory conditions. Overall, our study provides novel evidences that filamentous Actinobacteria could be key protagonists in the genesis of moonmilk through a wide spectrum of biomineralization processes.

  14. Extension of a PBPK model for ethylene glycol and glycolic acid to include the competitive formation and clearance of metabolites associated with kidney toxicity in rats and humans

    International Nuclear Information System (INIS)

    Corley, R.A.; Saghir, S.A.; Bartels, M.J.; Hansen, S.C.; Creim, J.; McMartin, K.E.; Snellings, W.M.

    2011-01-01

    A previously developed PBPK model for ethylene glycol and glycolic acid was extended to include glyoxylic acid, oxalic acid, and the precipitation of calcium oxalate that is associated with kidney toxicity in rats and humans. The development and evaluation of the PBPK model was based upon previously published pharmacokinetic studies coupled with measured blood and tissue partition coefficients and rates of in vitro metabolism of glyoxylic acid to oxalic acid, glycine and other metabolites using primary hepatocytes isolated from male Wistar rats and humans. Precipitation of oxalic acid with calcium in the kidneys was assumed to occur only at concentrations exceeding the thermodynamic solubility product for calcium oxalate. This solubility product can be affected by local concentrations of calcium and other ions that are expressed in the model using an ion activity product estimated from toxicity studies such that calcium oxalate precipitation would be minimal at dietary exposures below the NOAEL for kidney toxicity in the sensitive male Wistar rat. The resulting integrated PBPK predicts that bolus oral or dietary exposures to ethylene glycol would result in typically 1.4-1.6-fold higher peak oxalate levels and 1.6-2-fold higher AUC's for calcium oxalate in kidneys of humans as compared with comparably exposed male Wistar rats over a dose range of 1-1000 mg/kg. The converse (male Wistar rats predicted to have greater oxalate levels in the kidneys than humans) was found for inhalation exposures although no accumulation of calcium oxalate is predicted to occur until exposures are well in excess of the theoretical saturated vapor concentration of 200 mg/m 3 . While the current model is capable of such cross-species, dose, and route-of-exposure comparisons, it also highlights several areas of potential research that will improve confidence in such predictions, especially at low doses relevant for most human exposures.

  15. Indoor secondary organic aerosols formation from ozonolysis of monoterpene: An example of d-limonene with ammonia and potential impacts on pulmonary inflammations.

    Science.gov (United States)

    Niu, Xinyi; Ho, Steven Sai Hang; Ho, Kin Fai; Huang, Yu; Cao, Junji; Shen, Zhenxing; Sun, Jian; Wang, Xiumei; Wang, Yu; Lee, Shuncheng; Huang, Rujin

    2017-02-01

    Monoterpene is one class of biogenic volatile organic compounds (BVOCs) which widely presents in household cleaning products and air fresheners. It plays reactive role in secondary organic aerosols (SOAs) formation with ozone (O 3 ) in indoor environments. Such ozonolysis can be influenced by the presence of gaseous pollutants such as ammonia (NH 3 ). This study focuses on investigations of ozone-initiated formation of indoor SOAs with d-limonene, one of the most abundant indoor monoterpenes, in a large environmental chamber. The maximum total particle number concentration from the ozonolysis in the presence of NH 3 was 60% higher than that in the absence of NH 3 . Both of the nuclei coagulation and condensation involve in the SOAs growth. The potential risks of pulmonary injury for the exposure to the secondary particles formed were presented with the indexes of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) expression levels in bronchoalveolar lavage fluid (BALF) upon intratracheal instillation in mice lung for 6 and 12h. The results indicated that there was 22-39% stronger pulmonary inflammatory effect on the particles generated with NH 3 . This is a pilot study which demonstrates the toxicities of the indoor SOAs formed from the ozonolysis of a monoterpene. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. In vivo assessment of the toxic potential of Dissotis rotundifolia whole plant extract in Sprague–Dawley rats

    Directory of Open Access Journals (Sweden)

    Charles Ansah

    2016-07-01

    Conclusions: The results obtained from the sub-acute toxicological assessment of D. rotundifolia extract suggest that the extract is non-toxic at doses up to 1000 mg/kg/day administered for a period of 14 days.

  17. Toxicity of insecticides to Toxorhynchites splendens and three vector mosquitos and their sublethal effect on biocontrol potential of the predator.

    Science.gov (United States)

    Amalraj, D D; Das, P K

    1996-03-01

    Toxicity of six larvicides ie fenthion, temephos, malathion, deltamethrin, alphamethrin (Fendona), OMS 3031 and five adulticides ie malathion, fenitrothion, propoxur, deltamethrin, permethrin to Aedes aegypti, Culex quiquefasciatus, Anopheles stephensi and the predator, Toxorhynchites splendens was studied for evaluating safety margin. Concentrations of alphamethrin that killed 50% larvae of T. splendens were 53 and 12 times more than that which killed Cx. quinquefasciatus and Ae. aegypti. In case of deltamethrin, concentrations required to kill 50% larvae of T. splendens were 14 and 5 times more than that required against other two species. Other larvicides tested were equally toxic to both T. splendens and vector mosquitos. There was no significant difference in the toxicity of larvicides to T. splendens and An. stephensi. Deltamethrin was 25-132 times less toxic to adults of T. splendens in comparison to vector mosquitos. For other adulticides the range was 1-10. Immature developmental time of T. splendens was not affected by any of the insecticides tested. However, predation rate was lowered when larvae of Ae. aegypti previously exposed to fenthion and temephos were offered. Whereas, alphamethrin and OMS 3031 did not affect the feeding rate of the predator. There was a significant reduction in the pupal weight and pupation as a result of the predator feeding on the insecticide treated prey. There was a significant negative relationship between rate of pupation and dosage. The present study indicates that synthetic pyrethroids owing to their higher safety margin can be used in an integrated vector management program.

  18. Evaluation of subchronic (13 week), reproductive, and in vitro genetic toxicity potential of 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate (Octocrylene).

    Science.gov (United States)

    Odio, M R; Azri-Meehan, S; Robison, S H; Kraus, A L

    1994-04-01

    Use of 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate (Octocrylene) in commercial sunscreen products has increased considerably in recent years. To support larger scale human exposure to this compound, additional toxicological information was needed in several key areas. The present studies evaluated subchronic toxicity, developmental toxicity, and in vitro genotoxic potential of Octocrylene. In the subchronic study, male and female New Zealand white (NZW) rabbits treated topically with concentrations of octocrylene up to 534 mg/kg/day for 13 weeks showed slight to moderate dose-dependent skin irritation that correlated positively with a mild depression in body weight gain. Lack of associated histopathologic or clinical hematology abnormalities suggested that the body weight effect probably reflected a nonspecific response to topical irritation. In percutaneous developmental toxicity studies, NZW does were treated topically with Octocrylene at levels up to 267 mg/kg/day on Days 6 through 18 of gestation. Body weight gain, food consumption, and all maternal, reproductive, and offspring parameters evaluated were comparable between Octocrylene-treated and control animals. In the oral developmental toxicity assay, female CD-1 mice received oral doses of Octocrylene up to 1000 mg/kg/day on Days 8-12 of gestation. No evidence of maternal or developmental toxicity was seen at any dose tested. Genotoxicity was evaluated in vitro using the Chinese hamster ovary cell assay to assess clastogenicity and the mouse lymphoma cell assay to assess forward gene mutations. Octocrylene did not induce any significant increase in genotoxicity. This evaluation of toxicological potential supports the use of Octocrylene as a human photoprotectant.

  19. Influence of organic and inorganic nutrients on the phytoplankton structure of the Gulf of Riga and development of potentially toxic algae

    OpenAIRE

    Puriņa, Ingrīda

    2009-01-01

    The aaim of the study was to detect the influence of diisoved inorganic and organic nutrients on the phytoplankton composition of the Gulf of Riga and growth of potentially toxic algae. Experiments of nutrient limitation proved that nitrogen is the main limiting nutrient in the Gulf of Riga, especially during summer period and outside of rivers influence. Phosphorus mainly was limiting the phytoplankton development in the springtime and in the river plums. Experiments with different nutient c...

  20. Bioinformatics analysis to assess potential risks of allergenicity and toxicity of HRAP and PFLP proteins in genetically modified bananas resistant to Xanthomonas wilt disease.

    Science.gov (United States)

    Jin, Yuan; Goodman, Richard E; Tetteh, Afua O; Lu, Mei; Tripathi, Leena

    2017-11-01

    Banana Xanthomonas wilt (BXW) disease threatens banana production and food security throughout East Africa. Natural resistance is lacking among common cultivars. Genetically modified (GM) bananas resistant to BXW disease were developed by inserting the hypersensitive response-assisting protein (Hrap) or/and the plant ferredoxin-like protein (Pflp) gene(s) from sweet pepper (Capsicum annuum). Several of these GM banana events showed 100% resistance to BXW disease under field conditions in Uganda. The current study evaluated the potential allergenicity and toxicity of the expressed proteins HRAP and PFLP based on evaluation of published information on the history of safe use of the natural source of the proteins as well as established bioinformatics sequence comparison methods to known allergens (www.AllergenOnline.org and NCBI Protein) and toxins (NCBI Protein). The results did not identify potential risks of allergy and toxicity to either HRAP or PFLP proteins expressed in the GM bananas that might suggest potential health risks to humans. We recognize that additional tests including stability of these proteins in pepsin assay, nutrient analysis and possibly an acute rodent toxicity assay may be required by national regulatory authorities. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. High-throughput sequencing reveals microbial communities in drinking water treatment sludge from six geographically distributed plants, including potentially toxic cyanobacteria and pathogens.

    Science.gov (United States)

    Xu, Hangzhou; Pei, Haiyan; Jin, Yan; Ma, Chunxia; Wang, Yuting; Sun, Jiongming; Li, Hongmin

    2018-04-10

    The microbial community structures of drinking water treatment sludge (DWTS) generated for raw water (RW) from different locations and with different source types - including river water, lake water and reservoir water -were investigated using high-throughput sequencing. Because the unit operations in the six DWTPs were similar, community composition in fresh sludge may be determined by microbial community in the corresponding RW. Although Proteobacteria, Cyanobacteria, Bacteroidetes, Firmicutes, Verrucomicrobia, and Planctomycetes were the dominant phyla among the six DWTS samples, no single phylum exhibited similar abundance across all the samples, owing to differences in total phosphorus, chemical oxygen demand, Al, Fe, and chloride in RW. Three genera of potentially toxic cyanobacteria (Planktothrix, Microcystis and Cylindrospermopsis), and four potential pathogens (Escherichia coli, Bacteroides ovatus, Prevotella copri and Rickettsia) were found in sludge samples. Because proliferation of potentially toxic cyanobacteria and Rickettsia in RW was mainly affected by nutrients, while growth of Escherichia coli, Bacteroides ovatus and Prevotella copri in RW may be influenced by Fe, control of nutrients and Fe in RW is essential to decrease toxic cyanobacteria and pathogens in DWTS. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. UV-photodegradation of desipramine: Impact of concentration, pH and temperature on formation of products including their biodegradability and toxicity

    International Nuclear Information System (INIS)

    Khaleel, Nareman D.H.; Mahmoud, Waleed M.M.; Olsson, Oliver; Kümmerer, Klaus

    2016-01-01

    Desipramine (DMI) is a widely used tricyclic antidepressant, and it is the major metabolite of imipramine (IMI) and lofepramine (LMI); IMI and LMI are two of the most commonly used tricyclic antidepressants. If DMI enters the aquatic environment, it can be transformed by the environmental bacteria or UV radiation. Therefore, photolysis of DMI in water was performed using a simulated sunlight Xenon-lamp and a UV-lamp. Subsequently, the biodegradability of DMI and its photo-transformation products (PTPs) formed during its UV photolysis was studied. The influence of variable conditions, such as initial DMI concentration, solution pH, and temperature, on DMI UV photolysis behavior was also studied. The degree of mineralization of DMI and its PTPs was monitored. A Shimadzu HPLC-UV apparatus was used to follow the kinetic profile of DMI during UV-irradiation; after that, ion-trap and high-resolution mass spectrometry coupled with chromatography were used to monitor and identify the possible PTPs. The environmentally relevant properties and selected toxicity properties of DMI and the non-biodegradable PTPs were predicted using different QSAR models. DMI underwent UV photolysis with first-order kinetics. Quantum yields were very low. DOC values indicated that DMI formed new PTPs and was not completely mineralized. Analysis by means of high-resolution mass spectrometry revealed that the photolysis of DMI followed three main photolysis pathways: isomerization, hydroxylation, and ring opening. The photolysis rate was inversely proportional to initial DMI concentration. The pH showed a significant impact on the photolysis rate of DMI, and on the PTPs in terms of both formation kinetics and mechanisms. Although temperature was expected to increase the photolysis rate, it showed a non-significant impact in this study. Results from biodegradation tests and QSAR analysis revealed that DMI and its PTPs are not readily biodegradable and that some PTPs may be human and/or eco-toxic

  3. UV-photodegradation of desipramine: Impact of concentration, pH and temperature on formation of products including their biodegradability and toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Khaleel, Nareman D.H.; Mahmoud, Waleed M.M. [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Leuphana University of Lüneburg, Scharnhorststraße 1 C13, DE 21335 Lüneburg (Germany); Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522 (Egypt); Olsson, Oliver [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Leuphana University of Lüneburg, Scharnhorststraße 1 C13, DE 21335 Lüneburg (Germany); Kümmerer, Klaus, E-mail: klaus.kuemmerer@leuphana.de [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Leuphana University of Lüneburg, Scharnhorststraße 1 C13, DE 21335 Lüneburg (Germany)

    2016-10-01

    Desipramine (DMI) is a widely used tricyclic antidepressant, and it is the major metabolite of imipramine (IMI) and lofepramine (LMI); IMI and LMI are two of the most commonly used tricyclic antidepressants. If DMI enters the aquatic environment, it can be transformed by the environmental bacteria or UV radiation. Therefore, photolysis of DMI in water was performed using a simulated sunlight Xenon-lamp and a UV-lamp. Subsequently, the biodegradability of DMI and its photo-transformation products (PTPs) formed during its UV photolysis was studied. The influence of variable conditions, such as initial DMI concentration, solution pH, and temperature, on DMI UV photolysis behavior was also studied. The degree of mineralization of DMI and its PTPs was monitored. A Shimadzu HPLC-UV apparatus was used to follow the kinetic profile of DMI during UV-irradiation; after that, ion-trap and high-resolution mass spectrometry coupled with chromatography were used to monitor and identify the possible PTPs. The environmentally relevant properties and selected toxicity properties of DMI and the non-biodegradable PTPs were predicted using different QSAR models. DMI underwent UV photolysis with first-order kinetics. Quantum yields were very low. DOC values indicated that DMI formed new PTPs and was not completely mineralized. Analysis by means of high-resolution mass spectrometry revealed that the photolysis of DMI followed three main photolysis pathways: isomerization, hydroxylation, and ring opening. The photolysis rate was inversely proportional to initial DMI concentration. The pH showed a significant impact on the photolysis rate of DMI, and on the PTPs in terms of both formation kinetics and mechanisms. Although temperature was expected to increase the photolysis rate, it showed a non-significant impact in this study. Results from biodegradation tests and QSAR analysis revealed that DMI and its PTPs are not readily biodegradable and that some PTPs may be human and/or eco-toxic

  4. A study of antioxidant activity, enzymatic inhibition and in vitro toxicity of selected traditional sudanese plants with anti-diabetic potential

    Science.gov (United States)

    2014-01-01

    Background Diabetes mellitus is a chronic metabolic disease with life-threatening complications. Despite the enormous progress in conventional medicine and pharmaceutical industry, herbal-based medicines are still a common practice for the treatment of diabetes. This study evaluated ethanolic and aqueous extracts of selected Sudanese plants that are traditionally used to treat diabetes. Methods Extraction was carried out according to method described by Sukhdev et. al. and the extracts were tested for their glycogen phosphorylase inhibition, Brine shrimp lethality and antioxidant activity using (DPPH) radical scavenging activity and iron chelating activity. Extracts prepared from the leaves of Ambrosia maritima, fruits of Foeniculum vulgare and Ammi visnaga, exudates of Acacia Senegal, and seeds of Sesamum indicum and Nigella sativa. Results Nigella sativa ethanolic extract showed no toxicity on Brine shrimp Lethality Test, while its aqueous extract was toxic. All other extracts were highly toxic and ethanolic extracts of Foeniculum vulgare exhibited the highest toxicity. All plant extracts with exception of Acacia senegal revealed significant antioxidant activity in DPPH free radical scavenging assay. Conclusions These results highly agree with the ethnobotanical uses of these plants as antidiabetic. This study endorses further studies on plants investigated, to determine their potential for type 2 diabetes management. Moreover isolation and identification of active compounds are highly recommended. PMID:24885334

  5. Ultraviolet degradation of procymidone -structuralcharacterization by gas chromatography coupled with masss spectrometry and potential toxicity of photoproducts using in silico tests

    International Nuclear Information System (INIS)

    Rifai, A.; Jaber, F.; Souissi, Y.; Genty, Ch.; Bourcier, S.; Bouchonnet, S.; Clavaguera, C.

    2013-01-01

    RATIONALE: Procymidone is a dicarboximide fungicide mainly used for vineyard protection but also for different crops. The structural elucidation of by-products arising from the UV-visible photodegradation of procymidone has been investigated by gas chromatography coupled with mass spectrometry. The potential toxicities of photoproducts were estimated by in silico tests. METHODS: Aqueous solutions of procymidone were irradiated for up to 90 min in a self-made reactor equipped with a mercury lamp. Analyses were carried out on a gas chromatograph coupled with an ion trap mass spectrometer operated in electron ionization and methanol positive chemical ionization. Multistage collision-induced dissociation (CID) experiments were performed to establish dissociation pathways of ions. Toxicities of byproducts were estimated using the QSAR T.E.S.T. program. RESULTS: Sixteen photoproducts were investigated. Chemical structures were proposed mainly based on the interpretation of multistage CID experiments, but also on their relative retention times and kinetics data. These structures enabled photodegradation pathways to be suggested. Only three photoproducts remain present after 90 min of irradiation. Among them, 3,5-dichloroaniline presents a predicted rat LD50 toxicity about ten times greater than that of procymidone. CONCLUSIONS: 3,5-Dichloroaniline is the only photoproduct reported in previous articles. Eight by-products among the sixteen characterized might be as toxic, if not more, than procymidone itself considering the QSAR-predicted rat LD 50. (author)

  6. Assessment of D-methionine protecting cisplatin-induced otolith toxicity by vestibular-evoked myogenic potential tests, ATPase activities and oxidative state in guinea pigs.

    Science.gov (United States)

    Lo, Wu-Chia; Chang, Chih-Ming; Liao, Li-Jen; Wang, Chi-Te; Young, Yi-Ho; Chang, Yih-Leong; Cheng, Po-Wen

    2015-01-01

    To date, inadequate study has been devoted to the toxic vestibular effects caused by cisplatin. In addition, no electrophysiological examination has been conducted to assess cisplatin-induced otolith toxicity. The purposes of this study are thus two-fold: 1) to determine whether cervical vestibular-evoked myogenic potentials (VEMPs) and ocular VEMPs are practical electrophysiological methods of testing for cisplatin-induced otolith toxicity and 2) to examine if D-methionine (D-met) pre-injection would protect the otolith organs against cisplatin-induced changes in enzyme activities and/or oxidative status. Guinea pigs were intraperitoneally treated once daily with the following injections for seven consecutive days: sterile 0.9% saline control, cisplatin (5 mg/kg) only, D-met (300 mg/kg) only, or a combination of d-met (300 mg/kg) and cisplatin (5 mg/kg), respectively, with a 30 minute window in between. Each animal underwent the oVEMP and cVEMP tests before and after treatment. The changes in the biochemistry of the otolith organs, including membranous Na(+), K(+)-ATPase and Ca(2+)-ATPase, lipid peroxidation (LPO) levels and nitric oxide (NO) levels, were also evaluated. In the cisplatin-only treated guinea pigs, the mean amplitudes of the oVEMP tests were significantly (potolith dysfunction. D-Met attenuated the reduced ATPase activities and increased oxidative stress induced by cisplatin toxicity in the otolith organs. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Evaluation of miR-216a and miR-217 as Potential Biomarkers of Acute Exocrine Pancreatic Toxicity in Rats.

    Science.gov (United States)

    Wang, Jianying; Huang, Wenhu; Thibault, Stephane; Brown, Thomas P; Bobrowski, Walter; Gukasyan, Hovhannes J; Evering, Winston; Hu, Wenyue; John-Baptiste, Annette; Vitsky, Allison

    2017-02-01

    Detecting and monitoring exocrine pancreatic damage during nonclinical and clinical testing is challenging because classical biomarkers amylase and lipase have limited sensitivity and specificity. Novel biomarkers for drug-induced pancreatic injury are needed to improve safety assessment and reduce late-stage attrition rates. In a series of studies, miR-216a and miR-217 were evaluated as potential biomarkers of acute exocrine pancreatic toxicity in rats. Our results revealed that miR-216a and miR-217 were almost exclusively expressed in rat pancreas and that circulating miR-216a and miR-217 were significantly increased in rats following administration of established exocrine pancreatic toxicants caerulein (CL) and 1-cyano-2-hydroxy-3-butene (CHB) as well as in rats administered a proprietary molecule known to primarily affect the exocrine pancreas. Conversely, neither microRNA was increased in rats administered a proprietary molecule known to cause a lesion at the pancreatic endocrine-exocrine interface (EEI) or in rats administered an established renal toxicant. Compared with amylase and lipase, increases in miR-216a and miR-217 were of greater magnitude, persisted longer, and/or correlated better with microscopic findings within the exocrine pancreas. Our findings demonstrate that in rats, miR-216a and miR-217 are sensitive and specific biomarkers of acute exocrine pancreatic toxicity that may add value to the measurement of classical pancreatic biomarkers.

  8. The potential importance of steroids in the treatment of autistic spectrum disorders and other disorders involving mercury toxicity.

    Science.gov (United States)

    Geier, Mark R; Geier, David A

    2005-01-01

    Autism is a neurodevelopmental disorder that according to the Centers for Disease Control and Prevention (CDC) affects 1 in 150 children in the United States. Autism is characterized by impairments in social relatedness and communication, repetitive behaviors, abnormal movements, and sensory dysfunction. Recently emerging evidence suggests that mercury, especially from childhood vaccines, appears to be a factor in the development of the autistic disorders, and that autistic children have higher than normal body-burdens of mercury. In considering mercury toxicity, it has previously been shown that testosterone significantly potentates mercury toxicity, whereas estrogen is protective. Examination of autistic children has shown that the severity of autistic disorders correlates with the amount of testosterone present in the amniotic fluid, and an examination of a case-series of autistic children has shown that some have plasma testosterone levels that were significantly elevated in comparison neurotypical control children. A review of some of the current biomedical therapies for autistics, such as glutathione and cysteine, chelation, secretin, and growth hormone, suggests that they may in fact lower testosterone levels. We put forward the medical hypothesis that autistic disorders, in fact, represents a form of testosterone mercury toxicity, and based upon this observation, one can design novel treatments for autistics directed towards higher testosterone levels in autistic children. We suggest a series of experiments that need to be conducted in order to evaluate the exact mechanisms for mercury-testosterone toxicity, and various types of clinical manipulations that may be employed to control testosterone levels. It is hoped by devising therapies that address the steroid hormone pathways, in addition to the current treatments that successful lower heavy metal body-burdens of mercury, will work synergistically to improve clinical outcomes. In light of the fact that

  9. The Dialogic Potential of ePortfolios: Formative Feedback and Communities of Learning within a Personal Learning Environment

    Science.gov (United States)

    Ehiyazaryan-White, Ester

    2012-01-01

    This paper reports on the findings of a study into the use of ePortfolios as personal learning environments (PLE) by a group of students pursuing Master's degrees in Education. The qualitative study explores the potential of the ePortfolio to support learners in engaging in formative peer and tutor feedback as well as in developing a learning…

  10. Lithofacies Architecturing and Hydrocarbon Reservoir Potential of Lumshiwal Formation: Surghar Range, Trans-Indus Ranges, North Pakistan

    Directory of Open Access Journals (Sweden)

    Iftikhar Alam

    2015-12-01

    directed Paleo-current system prevailed during deposition of Lumshiwal Formation. Diagenetic and tectonically induced fractures make the formation exceedingly porous and permeable as suitable reservoir horizon for the accumulation of hydrocarbon in the Trans-Indus ranges. The same formation has already been proven as potential reservoir horizon for hydrocarbon in the Kohat Plateau of northwest Pakistan. Secondly, the formation is dominantly comprised of silica/quartz sandstone (quartzarenite which can be used as silica sand, one of the essential raw materials for glass industries. The formation is also comprised of local coal seams which can be mined for production of coal in the region.

  11. Assessment of the toxic and potential teratogenic effects of four glycol ethers and two derivatives using the hydra regeneration assay and rat whole embryo culture.

    Science.gov (United States)

    Bowden, H C; Wilby, O K; Botham, C A; Adam, P J; Ross, F W

    1995-10-01

    The widespread use of the glycol ethers as solvents in manufacturing industries presents a vast potential for occupational exposure. In the present study the potential hazards of four glycol ethers and two derivatives were assessed using two in vitro tests, rat whole embryo culture and the hydra regeneration assay. Concentrations used ranged from 0.3 to 1.0 mg/ml in embryo culture and from 0.03 to 80.0 mg/ml in the hydra assay. The embryotoxic potential of the ethylene glycol mono-alkyl ethers was shown to increase with the length of the alkyl chain. This is in contrast to in vivo data but can be explained by the lack of maternal metabolism in the in vitro systems. However, the teratogenic hazard ratings obtained in the hydra assay and the types of malformations observed in embryo culture support in vivo data. Results obtained for diethylene glycol monoethyl ether are in agreement with in vivo data. Results of both assays suggest that ethylene glycol monosalicylate presents a significant potential teratogenic hazard and that ethylene glycol tetra-acetic acid presents toxic and teratogenic potentials. When the effects of maternal toxicity and metabolism are considered, the overall picture presented by the present results is one of general agreement with in vivo data.

  12. Overview of the PCDD/Fs degradation potential and formation risk in the application of advanced oxidation processes (AOPs) to wastewater treatment.

    Science.gov (United States)

    Vallejo, Marta; Fresnedo San Román, M; Ortiz, Inmaculada; Irabien, Angel

    2015-01-01

    Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are a family of unintentionally produced persistent organic pollutants (POPs) that have received considerable public and scientific attention due to the toxicity of some of their congeners, more specifically those with chlorine substitution in the 2,3,7,8 positions. The environmental management and control of PCDD/Fs is addressed at a global level through the Stockholm Convention that establishes that POPs should be destroyed or irreversibly transformed in order to reduce or eliminate their release to the environment. Several technologies, including advanced oxidation processes (AOPs) such as photolysis, photocatalysis and Fenton oxidation, have been considered as effective methods for destroying PCDD/Fs in polluted waters. Nevertheless, during the remediation of wastewaters it is critical that the treatment technologies applied do not lead to the formation of by-products that are themselves POPs, especially if PCDD/Fs precursors or chlorine are present in the reaction medium. Despite the high effectiveness of AOPs in the oxidation of major contaminants, scarce references deal with the monitoring of PCDD/Fs in the course of the oxidation process, revealing that a detailed assessment of non-combustion technologies with respect to PCDD/Fs formation is still lacking. This study reports a review of the state of the art related to the potential remediation and/or formation of PCDD/Fs as a result of the application of AOPs for the treatment of polluted waters, warning on the correct selection of the operating conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. The interpretation of resonance formation in coupled-channel models of positron scattering by atomic hydrogen using localized optical potentials

    International Nuclear Information System (INIS)

    Bransden, B.H.; Hewitt, R.N.

    1997-01-01

    Above-threshold resonances can occur in coupled-channel models of the e + + H system when Ps formation is taken into account (although it should be pointed out that, in this specific system, resonances do not occur in an exact theory). In general, to understand the mechanism of resonance formation it is useful to obtain the exact optical potential in a given channel in a localized form. The methods of achieving this localization are discussed with reference to a specific application to the resonance found in the two-state approximation for the l = 0 partial wave. (author)

  14. Evaluation of the toxic potential of graphene copper nanocomposite (GCNC in the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZBg(9..

    Directory of Open Access Journals (Sweden)

    Yasir Hasan Siddique

    Full Text Available Graphene, a two-dimensional carbon sheet with single-atom thickness, have attracted the scientific world for its potential applications in various field including the biomedical areas. In the present study the graphene copper nanocomposite (GCNC was synthesized, characterized and evaluated for its toxic potential on third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZBg(9 . The synthesized GCNC was analyzed by X-ray diffraction (XRD, scanning/transmission electron microscopy (SEM/TEM, atomic force microscopy (AFM, and fourier transform infrared spectroscopy (FTIR. The GCNC in 0.1% DMSO was sonicated for 10 min and the final concentration of 0.033, 0.099, 0.199 and 3.996 µg/µl of diet were established. The third instar larvae were allowed to feed on it separately for 24 and 48 hrs. The hsp70 expression was measured by O-nitrophenyl-β-D-galactopyranoside assay, tissue damage by trypan blue exclusion test and β-galactosidase activity was monitored by in situ histochemical β-galactosidase staining. Oxidative stress was monitored by performing lipid peroxidation assay and total protein estimation. Ethidium bromide/acridine orange staining was performed on midgut cells for apoptotic index and the comet assay was performed for the DNA damage. The results of the present study showed that the exposure of 0.199 and 3.996 µg/µl of GCNC were toxic for 24 hr of exposure and for 48 hr of exposure: 0.099, 0.199 and 3.996 µg/µl of GCNC was toxic. The dose of 0.033 µg/µl of GCNC showed no toxic effects on its exposure to the third instar larvae for 24 hr as well as 48 hrs. This dose can be considered as No Observed Adverse Effect Level (NOAEL.

  15. Orthodontic treatment with fixed appliances and biofilm formation-a potential public health threat?

    NARCIS (Netherlands)

    Ren, Yijin; Jongsma, Marije A.; Mei, Li; van der Mei, Henny C.; Busscher, Henk J.

    OBJECTIVES: Orthodontic treatment is highly popular for restoring functional and facial esthetics in juveniles and adults. As a downside, prevalence of biofilm-related complications is high. Objectives of this review are to (1) identify special features of biofilm formation in orthodontic patients

  16. Formative Interventions in Leadership Development in Early Childhood Education: The Potential of Double Stimulation

    Science.gov (United States)

    Nuttall, Joce; Thomas, Louise; Henderson, Linda

    2018-01-01

    This article critiques the usefulness of double stimulation, a key concept in Vygotskian analyses of human development, with leaders in early childhood services in Australia. A series of formative interventions was conducted to identify and address systemic tensions that were confounding leaders' attempts to realise a central object of activity in…

  17. Clonal variation in growth plasticity within a Bosmina longirostris population: the potential for resistance to toxic cyanobacteria.

    Directory of Open Access Journals (Sweden)

    Xiaodong Jiang

    Full Text Available Many aquatic organisms respond phenotypically, through morphological, behavioral, and physiological plasticity, to environmental changes. The small-size cladoceran Bosminalongirostris, a dominant zooplankter in eutrophic waters, displayed reduced growth rates in response to the presence of a toxic cyanobacterium, Microcystisaeruginosa, in their diets. The magnitude of growth reduction differed among 15 clones recently isolated from a single population. A significant interaction between clone and food type indicated a genetic basis for the difference in growth plasticity. The variation in phenotypic plasticity was visualized by plotting reaction norms with two diets. The resistance of each clone to dietary cyanobacteria was measured as the relative change in growth rates on the "poor" diet compared with the "good" diet. The enhanced resistance to M. aeruginosa in B. longirostris was derived from both the reduced slope of reaction norms and the increased mean growth rates with two diets. The large clonal variation within a B. longirostris population may contribute to local adaptation to toxic cyanobacteria and influence ecosystem function via clonal succession.

  18. Tricalcium phosphate/hydroxyapatite (TCP-HA) bone scaffold as potential candidate for the formation of tissue engineered bone.

    Science.gov (United States)

    Sulaiman, Shamsul Bin; Keong, Tan Kok; Cheng, Chen Hui; Saim, Aminuddin Bin; Idrus, Ruszymah Bt Hj

    2013-06-01

    Various materials have been used as scaffolds to suit different demands in tissue engineering. One of the most important criteria is that the scaffold must be biocompatible. This study was carried out to investigate the potential of HA or TCP/HA scaffold seeded with osteogenic induced sheep marrow cells (SMCs) for bone tissue engineering. HA-SMC and TCP/HA-SMC constructs were induced in the osteogenic medium for three weeks prior to implantation in nude mice. The HA-SMC and TCP/HA-SMC constructs were implanted subcutaneously on the dorsum of nude mice on each side of the midline. These constructs were harvested after 8 wk of implantation. Constructs before and after implantation were analyzed through histological staining, scanning electron microscope (SEM) and gene expression analysis. The HA-SMC constructs demonstrated minimal bone formation. TCP/HA-SMC construct showed bone formation eight weeks after implantation. The bone formation started on the surface of the ceramic and proceeded to the centre of the pores. H&E and Alizarin Red staining demonstrated new bone tissue. Gene expression of collagen type 1 increased significantly for both constructs, but more superior for TCP/HA-SMC. SEM results showed the formation of thick collagen fibers encapsulating TCP/HA-SMC more than HA-SMC. Cells attached to both constructs surface proliferated and secreted collagen fibers. The findings suggest that TCP/HA-SMC constructs with better osteogenic potential compared to HA-SMC constructs can be a potential candidate for the formation of tissue engineered bone.

  19. Quaternary North Atlantic Surface Paleoceanography in Regions of Potential Deep-water Formation

    Science.gov (United States)

    Ruddiman, W. F.

    1984-01-01

    At the time scale of the Quaternary climate cycles, the sites of formation of North Atlantic Deep Water are not known. The interglacial extreme is presumably exemplified by the modern regions; the Norwegian, Greenland and Labrador Seas. During the major glacial-age coolings in the North Atlantic, the sites may have shifted well to the south, perhaps as far as the limit of the polar front at 40 to 50 N. Still other sites may have been important during intermediate climatic conditions. Because of the close coupling of high-latitude surface waters to North Atlantic Deep Water in the modern ocean, the history of sea-surface temperature (SST) oscillations across the high-latitude North Atlantic is relevant to an understanding of deep-water formation on the longer time scales.

  20. Preliminary analyses of scenarios for potential human interference for repositories in three salt formations

    Energy Technology Data Exchange (ETDEWEB)

    1985-10-01

    Preliminary analyses of scenarios for human interference with the performance of a radioactive waste repository in a deep salt formation are presented. The following scenarios are analyzed: (1) the U-Tube Connection Scenario involving multiple connections between the repository and the overlying aquifer system; (2) the Single Borehole Intrusion Scenario involving penetration of the repository by an exploratory borehole that simultaneously connects the repository with overlying and underlying aquifers; and (3) the Pressure Release Scenario involving inflow of water to saturate any void space in the repository prior to creep closure with subsequent release under near lithostatic pressures following creep closure. The methodology to evaluate repository performance in these scenarios is described and this methodology is applied to reference systems in three candidate formations: bedded salt in the Palo Duro Basin, Texas; bedded salt in the Paradox Basin, Utah; and the Richton Salt Dome, Mississippi, of the Gulf Coast Salt Dome Basin.

  1. Preliminary analyses of scenarios for potential human interference for repositories in three salt formations

    International Nuclear Information System (INIS)

    1985-10-01

    Preliminary analyses of scenarios for human interference with the performance of a radioactive waste repository in a deep salt formation are presented. The following scenarios are analyzed: (1) the U-Tube Connection Scenario involving multiple connections between the repository and the overlying aquifer system; (2) the Single Borehole Intrusion Scenario involving penetration of the repository by an exploratory borehole that simultaneously connects the repository with overlying and underlying aquifers; and (3) the Pressure Release Scenario involving inflow of water to saturate any void space in the repository prior to creep closure with subsequent release under near lithostatic pressures following creep closure. The methodology to evaluate repository performance in these scenarios is described and this methodology is applied to reference systems in three candidate formations: bedded salt in the Palo Duro Basin, Texas; bedded salt in the Paradox Basin, Utah; and the Richton Salt Dome, Mississippi, of the Gulf Coast Salt Dome Basin

  2. Porosity and reservoir potentiality of the Cherahil Formation limestone (middle-upper Eocene) in the Gulf of Gabes (Tunisia)

    Science.gov (United States)

    Njahi, Zahra; Kassabi, Nadhem; Touir, Jamel

    2017-07-01

    During the middle and upper Eocene, the deposits in the Gulf of Gabes correspond to the Cherahil Formation, which is sub-divided into three units, which are as follows from base to top: the Lower Cherahil A, the Siouf and the Upper Cherahil B members. The Siouf member has a lateral equivalent in the Souar Formation named Reineche member. The Cherahil Formation has never been considered by oil companies as a particular drilling target in the Gulf of Gabes (offshore east Tunisia) despite the presence of hydrocarbon at the bottom of Cherahil Formation in Sidi Behara and Sidi Litayem oil fields in Sfax Area (onshore east Tunisia) and in its equivalent carbonate beds in Jebel Trozza (Central Tunisia). Therefore, the evaluation of porosity in the carbonate levels of Cherahil Formation in 20 drilling wells were performed on well logging by applying Wyllie method. The obtained results show that the studied carbonates are characterized by an economically important total porosity average ranging between 5% and 55%, and both vertical and lateral variations. The vertical porosity variation was controlled by the sea-level fluctuation that, in turn, controlled the evolution of carbonate sedimentary environments and relative facies. The lateral porosity variation followed the Tunisian middle-upper Eocene paleogeography changes controlled by NW-SE synsedimentary tectonic trends. Considering the important features of the Cherahil Formation and the coexistence of components of an oil system in the Gulf of Gabes, this formation can be an important potential reservoir and subsequently a new petroleum exploration target in the Gulf of Gabes.

  3. Formation of compensation mechanism of regional enterprises’ human resources regeneration in the labor potential development system

    OpenAIRE

    Alexeev, I.; Voloshyn, O.

    2013-01-01

    The article substantiates the formation principles of administration bodies in implementation of compensation mechanism of human resources regeneration. It defines stages of the preparatory period of forming administration bodies of human resources regeneration with the primary units for training and exploitation of human resources, for which was designed the organizational structure of enterprise’s personnel departments subdivisions. A model of a compensation mechanism for regeneration of...

  4. Antigenotoxic potential of Asparagus racemosus root extract against electron beam radiation induced micronuclei formation in Swiss albino mice

    International Nuclear Information System (INIS)

    Bhandary, B. Satheesh Kumar; Sharmila, K.P.; Suchetha Kumari, N.; Bhat, Vadish S.; Shetty, Jayaram; Peter, Alex John; Jose, Jerish M.; Fernandes, Ronald

    2016-01-01

    To evaluate the antigenotoxic potential of Asparagus Racemosus Root ethanolic extract (ARE) against electron beam radiation induced micronuclei formation in Swiss albino mice. Micronucleus assay was performed in the bone marrow of Swiss albino mice according to the method of Hosseinimehr et al., 2003. The experimental animals were orally administered 200 mg/kg body weight of ARE once daily for 15 consecutive days. At the end of experimental period, the animals were euthanized and the bone marrow was collected from the femur. Control (C), Radiation control (RC) and drug control (DC) group was also maintained. The number of radiation induced Micronucleated Polychromatic Erythrocytes (MnPCE) and Micronucleated Normochromatic Erythrocytes were decreased in the ARE treated mice which was statistically significant (p<0.05) compared to radiation control group. Present findings demonstrate the antigenotoxic potential of ARE against electron beam radiation induced micronuclei formation which may be attributed to scavenging of radiation-induced free radicals

  5. Leaching characteristics of a high-calcium fly ash as a function of pH: a potential source of selenium toxicity

    Science.gov (United States)

    Grisafe, D.A.; Angino, E.E.; Smith, S.M.

    1988-01-01

    Using a modified extraction procedure, the effect of pH on the leaching of selected elements from Ca-rich (Type C) power plant fly ash was studied. Continuous additions of acetic acid were used to maintain pH values of fly ash slurries at 4.0, 6.0 and 8.0 for 24 h and an additional set was leached at its natural pH (average 11.8) value. Analyses for Se, As, Ca, Cd, Cr, Fe, Na and Pb showed that the highest concentrations occur in the leachate at pH 4.0 and decline with increasing pH. Concentrations of Cr and Fe increased slightly between neutral and high pH. Arsenic, Cd, Cr, Pb and Se concentrations exceeded the Environmental Protection Agency's toxicity criteria at pH 4.0. Selenium was above its toxicity level at pH values near 7 but the other elements were below their respective toxicity levels near neutral pH. Because recent studies show adverse effects of Se on aquatic life at far lower concentrations than the current Environmental Protection Agency's standard, high-Ca, power plant fly ashes represent a potentially hazardous pollutant to surface and subsurface waters. ?? 1988.

  6. Evaluation of the toxic potential of calcium carbide in the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg(9).

    Science.gov (United States)

    Danish, Mohd; Fatima, Ambreen; Khanam, Saba; Jyoti, Smita; Rahul; Ali, Fahad; Naz, Falaq; Siddique, Yasir Hasan

    2015-11-01

    In the present study the toxic potential of calcium carbide (CaC2) was studied on the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg(9). The third instar larvae were exposed to 2, 4, 8, 16 and 32×10(-3)g/ml of CaC2 in diet for 24h. The results reveal that the dose 2×10(-3)g/ml was not toxic but the remaining doses showed a dose dependent significant increase in the hsp70 expression, β-galactosidase activity, tissue damage, oxidative stress markers (lipid peroxidation and protein carbonyl content), glutathione-S-transferase activity, expression of Caspase 3 and 9, apoptotic index and DNA damage (midgut cells). A significant reduction as compared to control group in total protein, glutathione content and acetylcholinesterase activity was also observed. The Inductively Coupled Plasma Atomic Emission Spectroscopy analysis (ICPAES) reveals the presence of copper, iron, sodium, aluminium, manganese, calcium, nickel and mercury. The toxic effects of CaC2 in the present study may be attributed to the impurities present in it. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Potential role for MATER in cytoplasmic lattice formation in murine oocytes.

    Directory of Open Access Journals (Sweden)

    Boram Kim

    2010-09-01

    Full Text Available Mater and Padi6 are maternal effect genes that are first expressed during oocyte growth and are required for embryonic development beyond the two-cell stage in the mouse. We have recently found that PADI6 localizes to, and is required for the formation of, abundant fibrillar Triton X-100 (Triton insoluble structures termed the oocyte cytoplasmic lattices (CPLs. Given their similar expression profiles and mutant mouse phenotypes, we have been testing the hypothesis that MATER also plays a role in CPL formation and/or function.Herein, we show that PADI6 and MATER co-localize throughout the oocyte cytoplasm following Triton extraction, suggesting that MATER co-localizes with PADI6 at the CPLs. Additionally, the solubility of PADI6 was dramatically increased in Mater(tm/tm oocytes following Triton extraction, suggesting that MATER is involved in CPL nucleation. This prediction is supported by transmission electron microscopic analysis of Mater(+/+ and Mater(tm/tm germinal vesicle stage oocytes which illustrated that volume fraction of CPLs was reduced by 90% in Mater(tm/tm oocytes compared to Mater(+/+ oocytes.Taken together, these results suggest that, similar to PADI6, MATER is also required for CPL formation. Given that PADI6 and MATER are essential for female fertility, these results not only strengthen the hypothesis that the lattices play a critical role in mediating events during the oocyte-to-embryo transition but also increase our understanding of the molecular nature of the CPLs.

  8. Assessing reproductive toxicity of two environmental toxicants with a novel in vitro human spermatogenic model

    Directory of Open Access Journals (Sweden)

    Charles A. Easley, IV

    2015-05-01

    Full Text Available Environmental influences and insults by reproductive toxicant exposure can lead to impaired spermatogenesis or infertility. Understanding how toxicants disrupt spermatogenesis is critical for determining how environmental factors contribute to impaired fertility. While current animal models are available, understanding of the reproductive toxic effects on human fertility requires a more robust model system. We recently demonstrated that human pluripotent stem cells can differentiate into spermatogonial stem cells/spermatogonia, primary and secondary spermatocytes, and haploid spermatids; a model that mimics many aspects of human spermatogenesis. Here, using this model system, we examine the effects of 2-bromopropane (2-BP and 1,2,dibromo-3-chloropropane (DBCP on in vitro human spermatogenesis. 2-BP and DBCP are non-endocrine disrupting toxicants that are known to impact male fertility. We show that acute treatment with either 2-BP or DBCP induces a reduction in germ cell viability through apoptosis. 2-BP and DBCP affect viability of different cell populations as 2-BP primarily reduces spermatocyte viability, whereas DBCP exerts a much greater effect on spermatogonia. Acute treatment with 2-BP or DBCP also reduces the percentage of haploid spermatids. Both 2-BP and DBCP induce reactive oxygen species (ROS formation leading to an oxidized cellular environment. Taken together, these results suggest that acute exposure with 2-BP or DBCP causes human germ cell death in vitro by inducing ROS formation. This system represents a unique platform for assessing human reproductive toxicity potential of various environmental toxicants in a rapid, efficient, and unbiased format.

  9. Multispecies animal investigation on biodistribution, pharmacokinetics and toxicity of 177Lu-EDTMP, a potential bone pain palliation agent

    International Nuclear Information System (INIS)

    Mathe, Domokos; Balogh, Lajos; Polyak, Andras; Kiraly, Reka; Marian, Terez; Pawlak, Dariusz; Zaknun, John J.; Pillai, Maroor R.A.; Janoki, Gyozo A.

    2010-01-01

    Introduction: Radionuclide therapy (RNT) is an effective method for bone pain palliation in patients suffering from bone metastasis. Due to the long half-life, easy production and relatively low β- energy, 177 Lu [T 1/2 =6.73 days, E βmax =497 keV, E γ =113 keV (6.4%), 208 keV (11%)]-based radiopharmaceuticals offer logistical advantage for wider use. This paper reports the results of a multispecies biodistribution and toxicity studies of 177 Lu-EDTMP to collect preclinical data for starting human clinical trials. Methods: 177 Lu-EDTMP with radiochemical purity greater than 99% was formulated by using a lyophilized kit of EDTMP (35 mg of EDTMP, 5.72 g of CaO and 14.1 mg of NaOH). Biodistribution studies were conducted in mice and rabbits. Small animal imaging was performed using NanoSPECT/CT (Mediso, Ltd., Hungary) and digital autoradiography. Gamma camera imaging was done in rabbits and dogs. Four levels of activity (9.25 through 37 MBq/kg body weight) of 177 Lu-EDTMP were injected in four groups of three dogs each to study the toxicological effects. Results: 177 Lu-EDTMP accumulated almost exclusively in the skeletal system (peak ca. 41% of the injected activity in bone with terminal elimination half-life of 2130 and 1870 h in mice and rabbits, respectively) with a peak uptake during 1-3 h. Excretion of the radiopharmaceutical was through the urinary system. Imaging studies showed that all species (mouse, rat, rabbit and dog) take up the compound in regions of remodeling bone, while kidney retention is not visible after 1 day postinjection (pi). In dogs, the highest applied activity (37 MBq/kg body weight) led to a moderate decrease in platelet concentration (mean, 160 g/L) at 1 week pi with no toxicity. Conclusion: The protracted effective half-life of 177 Lu-EDTMP in bone supports that modifying the EDTMP molecule by introducing 177 Lu does not alter its biological behaviour as a specific bone-seeking tracer. Species-specific pharmacokinetic behavior

  10. Multispecies animal investigation on biodistribution, pharmacokinetics and toxicity of {sup 177}Lu-EDTMP, a potential bone pain palliation agent

    Energy Technology Data Exchange (ETDEWEB)

    Mathe, Domokos [Department of Applied Radioisotopes and Animal Experimentation, National ' Frederic Joliot-Curie' Institute of Radiobiology and Radiohygiene, H-1221 Budapest (Hungary)], E-mail: mdomokos@hp.osski.hu; Balogh, Lajos; Polyak, Andras; Kiraly, Reka [Department of Applied Radioisotopes and Animal Experimentation, National ' Frederic Joliot-Curie' Institute of Radiobiology and Radiohygiene, H-1221 Budapest (Hungary); Marian, Terez [Institute of Nuclear Medicine, Debrecen University, Debrecen (Hungary); Pawlak, Dariusz [Institute of Atomic Energy, Radioisotope Centre POLATOM, Swierk-Otwock (Poland); Zaknun, John J.; Pillai, Maroor R.A. [International Atomic Energy Agency (IAEA), Vienna (Austria); Janoki, Gyozo A. [Department of Applied Radioisotopes and Animal Experimentation, National ' Frederic Joliot-Curie' Institute of Radiobiology and Radiohygiene, H-1221 Budapest (Hungary)

    2010-02-15

    Introduction: Radionuclide therapy (RNT) is an effective method for bone pain palliation in patients suffering from bone metastasis. Due to the long half-life, easy production and relatively low {beta}- energy, {sup 177}Lu [T{sub 1/2}=6.73 days, E{sub {beta}}{sub max}=497 keV, E{sub {gamma}}=113 keV (6.4%), 208 keV (11%)]-based radiopharmaceuticals offer logistical advantage for wider use. This paper reports the results of a multispecies biodistribution and toxicity studies of {sup 177}Lu-EDTMP to collect preclinical data for starting human clinical trials. Methods: {sup 177}Lu-EDTMP with radiochemical purity greater than 99% was formulated by using a lyophilized kit of EDTMP (35 mg of EDTMP, 5.72 g of CaO and 14.1 mg of NaOH). Biodistribution studies were conducted in mice and rabbits. Small animal imaging was performed using NanoSPECT/CT (Mediso, Ltd., Hungary) and digital autoradiography. Gamma camera imaging was done in rabbits and dogs. Four levels of activity (9.25 through 37 MBq/kg body weight) of {sup 177}Lu-EDTMP were injected in four groups of three dogs each to study the toxicological effects. Results: {sup 177}Lu-EDTMP accumulated almost exclusively in the skeletal system (peak ca. 41% of the injected activity in bone with terminal elimination half-life of 2130 and 1870 h in mice and rabbits, respectively) with a peak uptake during 1-3 h. Excretion of the radiopharmaceutical was through the urinary system. Imaging studies showed that all species (mouse, rat, rabbit and dog) take up the compound in regions of remodeling bone, while kidney retention is not visible after 1 day postinjection (pi). In dogs, the highest applied activity (37 MBq/kg body weight) led to a moderate decrease in platelet concentration (mean, 160 g/L) at 1 week pi with no toxicity. Conclusion: The protracted effective half-life of {sup 177}Lu-EDTMP in bone supports that modifying the EDTMP molecule by introducing {sup 177}Lu does not alter its biological behaviour as a specific bone

  11. Diet-induced obesity in male mice is associated with reduced fertility and potentiation of acrylamide-induced reproductive toxicity.

    Science.gov (United States)

    Ghanayem, Burhan I; Bai, Re; Kissling, Grace E; Travlos, Greg; Hoffler, Undi

    2010-01-01

    The prevalence of human obesity and related chronic disorders such as diabetes, cardiovascular diseases, and cancer is rapidly increasing. Human studies have shown a direct relationship between obesity and infertility. The objective of the current work was to examine the effect of diet-induced obesity on male fertility and the effect of obesity on susceptibility to chemical-induced reproductive toxicity. From 5 to 30 wk of age, genetically intact male C57Bl/6J mice were fed a normal diet or one in which 60% of the kilocalories were from lard. Obese mice exhibited significant differences in the mRNA of several genes within the testes in comparison to lean males. Pparg was increased 2.2-fold, whereas Crem, Sh2b1, Dhh, Igf1, and Lepr were decreased 6.7, 1.4, 3.2, 1.6, and 7.2-fold, respectively. The fertility of male mice was compared through mating with control females. Acrylamide (AA)-induced reproductive toxicity was assessed in obese or lean males treated with water or 25 mg AA kg(-1) day(-1) via gavage for 5 days and then mated to control females. Percent body fat and weight were significantly increased in mice fed a high-fat vs. a normal diet. Obesity resulted in significant reduction in plugs and pregnancies of control females partnered with obese vs. lean males. Serum leptin and insulin levels were each approximately 5-fold higher in obese vs. age-matched lean mice. Sperm from obese males exhibited decreased motility and reduced hyperactivated progression vs. lean mice. Treatment with AA exacerbated male infertility of obese and lean mice; however, this effect was more pronounced in obese mice. Further, females partnered with AA-treated obese mice exhibited a further decrease in the percentage of live fetuses, whereas the percentage of resorptions increased. This work demonstrated that diet-induced obesity in mice caused a significant reduction in male fertility and exacerbated AA-induced reproductive toxicity and germ cell mutagenicity.

  12. Risk assessment of potentially toxic element pollution in soils and rice (Oryza sativa) in a typical area of the Yangtze River Delta

    International Nuclear Information System (INIS)

    Hang Xiaoshuai; Wang Huoyan; Zhou Jianmin; Ma Chengling; Du Changwen; Chen Xiaoqin

    2009-01-01

    Soil pollution with potentially toxic elements (PTEs) resulting from rapid industrial development has caused major concerns. Selected PTEs and their accumulation and distribution in soils and rice (Oryza sativa) collected from Changshu, east China, were analyzed to evaluate the potential health risk to the local population. The soils were primarily contaminated with Hg, followed by Cu, Cd, Pb, and Zn. The concentrations of Pb, Hg, and Cd of 46, 32, and 1 rice samples exceeded their national maximum allowable levels in foods, respectively. Spatial distributions of total Cr, Cu, Pb, Zn, and Cd in soils shared similar geographical trends. The risk assessment of PTEs through rice consumption suggests that the concentrations of Cu, Pb, and Cd in some rice samples exceed their reference oral dose for adults and children. In general, there was no target hazard quotient value of any individual element that was greater than 1, but hazard index values for adults and children were 1.726 and 1.523, respectively. - Industrial development has led to increased risk from potentially toxic elements in soils and rice.

  13. Risk assessment of potentially toxic element pollution in soils and rice (Oryza sativa) in a typical area of the Yangtze River Delta

    Energy Technology Data Exchange (ETDEWEB)

    Hang Xiaoshuai [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 Beijing East Road, Nanjing 210008, Jiangsu Province (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Wang Huoyan, E-mail: hywang@issas.ac.c [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 Beijing East Road, Nanjing 210008, Jiangsu Province (China); Zhou Jianmin [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 Beijing East Road, Nanjing 210008, Jiangsu Province (China); Ma Chengling [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 Beijing East Road, Nanjing 210008, Jiangsu Province (China); Weifang Municipal Environmental Protection Bureau, Weifang 261041, Shandong Province (China); Du Changwen; Chen Xiaoqin [State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, 71 Beijing East Road, Nanjing 210008, Jiangsu Province (China)

    2009-08-15

    Soil pollution with potentially toxic elements (PTEs) resulting from rapid industrial development has caused major concerns. Selected PTEs and their accumulation and distribution in soils and rice (Oryza sativa) collected from Changshu, east China, were analyzed to evaluate the potential health risk to the local population. The soils were primarily contaminated with Hg, followed by Cu, Cd, Pb, and Zn. The concentrations of Pb, Hg, and Cd of 46, 32, and 1 rice samples exceeded their national maximum allowable levels in foods, respectively. Spatial distributions of total Cr, Cu, Pb, Zn, and Cd in soils shared similar geographical trends. The risk assessment of PTEs through rice consumption suggests that the concentrations of Cu, Pb, and Cd in some rice samples exceed their reference oral dose for adults and children. In general, there was no target hazard quotient value of any individual element that was greater than 1, but hazard index values for adults and children were 1.726 and 1.523, respectively. - Industrial development has led to increased risk from potentially toxic elements in soils and rice.

  14. Investigating a probable relationship between microplastics and potentially toxic elements in fish muscles from northeast of Persian Gulf.

    Science.gov (United States)

    Akhbarizadeh, Razegheh; Moore, Farid; Keshavarzi, Behnam

    2018-01-01

    Although weekly consumption of fish is recommended, the presence of contaminants in seafood has raised many concerns regarding the benefits of fish intake. In the present study microplastics (MPs) and metals' concentration in muscles of both benthic and pelagic fish species from northeast of Persian Gulf were investigated and the risk/benefit of their consumption was assessed. The results demonstrated that MPs and Hg in all species and Se in benthic species increase with size, while relationship between other metals, and fish size is not consistent. Consumption of a meal ration of 300 and relationship between MPs and metals in fish muscles were positive for A. djedaba, and negative for E. coioides. Considering the chemical toxicity of MPs and metals, and their good linear relationships in some species, consumption of high doses of the studied fish may pose a health threat to the consumers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Rice is a potential dietary source of not only arsenic but also other toxic elements like lead and chromium

    Directory of Open Access Journals (Sweden)

    Amjad M. Shraim

    2017-05-01

    Full Text Available Rice is a staple food and a good source of nutrition for half of the earth’s population including Middle Eastern countries. However, rice may accumulate hazardous levels of toxic elements. In KSA, rice is imported from many countries; some of which suffer from arsenic contamination in their groundwater and soil. Despite the large daily consumption of rice in KSA, no investigations on the contamination of rice sold there are published so far. Additionally, reports on the contamination of rice with other toxic elements are rare in the literature. To investigate this issue, a total of 84 rice samples were collected from local markets in Almadinah Almunawarah, KSA (n = 70 and Brisbane, Australia (n = 12 and analyzed for arsenic and other elements by ICP-MS. The mean concentrations (mg kg−1 for the KSA samples with concentrations >LOQ were 0.136 for As (range 0.026–0.464, n = 70; Cd: 0.017 (0.003–0.046, n = 64; Pb: 0.029 (0.003–0.218, n = 40; Ni: 0.064 (0.042–0.086, n = 5; Mg: 157 (51.8–777, n = 70; Mn: 4.28 (0.960–10.9, n = 70; Fe: 7.07 (1.9–55.1, n = 70; Zn: 6.19 (1.15–13.5, n = 70; Cu 1.28 (0.508–2.41, n = 70; Se 0.202 (0.007–0.574, n = 70; Cr: 0.057 (0.010–0.184, n = 19; and Co: 0.012 (0.001–0.116, n = 56. Several samples were found to contain at least one element in excess of the Chinese MCL (0.2 mg kg−1for Cd, Cr, Pb, and iAs each. A large variation in element concentration was observed for samples of different origins. In comparison, the American rice accumulated the highest arsenic concentration (mean 0.257 mg kg−1 followed by the Thai rice (mean 0.200 mg kg−1, the Pakistani rice (mean 0.147 mg kg−1, the Indian rice (mean 0.103 mg kg−1, and finally the Egyptian rice (mean 0.097 mg kg−1. Additionally, 3 individual samples from Surinam, Australia, and France contained arsenic concentrations (mg kg−1 of 0.290, 0.188, and 0.183. The findings of this investigation

  16. Future research needs associated with the assessment of potential human health risks from exposure to toxic ambient air pollutants

    DEFF Research Database (Denmark)

    Möller, Lennart; Schuetzle, Dennis; Autrup, Herman

    1994-01-01

    This paper presents key conclusions and future research needs from a Workshop on the Risk Assessment of Urban Air, Emissions, Exposure, Risk Identification, and Quantification, which was held in Stockholm during June 1992 by 41 participants from 13 countries. Research is recommended in the areas...... of identification and quantification of toxics in source emissions and ambient air, atmospheric transport and chemistry, exposure level assessment, the development of improved in vitro bioassays, biomarker development, the development of more accurate epidemiological methodologies, and risk quantification...... techniques. Studies are described that will be necessary to assess and reduce the level of uncertainties associated with each step of the risk assessment process. International collaborative research efforts between industry and government organizations are recommended as the most effective way to carry out...

  17. Influence of the Reform of Local Self-Government in Ukraine on the Formation and Development of Labor Potential

    Directory of Open Access Journals (Sweden)

    Kharuk Kateryna B.

    2015-09-01

    Full Text Available The article determines the peculiarities of formation and development of the labor potential in the process of the reforming local self-government in Ukraine. It has been found that an integration of population, the system of economic entities, infrastructure units, scientific-technical potential allows to determine the need for modern spatial forms of concentration of labor potential, i.e. for consolidated territorial communities. With the purpose of formation and development of labor potential, considering impacts of the reform of local self-government in Ukraine, the following activities has been proposed to be carried out: improving the living standards of rural residents, creation of productive jobs, socio-economic cooperation between communities, infrastructure development, use of natural resources, socio-labor, agricultural and industrial capacities, effective use of rural socio-labour potential, development of agricultural production, rural non-farm activities, development of social infrastructure, creation of advisory service and introduction of a system of continuous education, development of family medicine, collaboration with regional and central authorities, involvement of the regional budget funds, establishment of a fund for economic development, cooperation with domestic and foreign investors. It has been determined that the introduction of the above measures will affect the increase in employment within the consolidated territorial communities.

  18. Evaluation of chemopreventive potential of Strobilanthes crispus against colon cancer formation in vitro and in vivo.

    Science.gov (United States)

    Al-Henhena, Nawal; Khalifa, Shaden A M; Ying, Rozaida Poh Yuen; Ismail, Salmah; Hamadi, Riad; Shawter, Abdrabu N; Idris, Azila Mohd; Azizan, Ainnul; Al-Wajeeh, Nahla Saeed; Abdulla, Mahmood Ameen; El-Seedi, Hesham R

    2015-11-25

    With cancer being one of the major causes of death around the world, studies are ongoing to find new chemotherapeutic leads. There are common mechanisms for colorectal cancer (CRC) formation. Several are connected with oxidative stress-induced cell apoptosis and others are related to imbalanced homeostasis or intake of drugs/toxins. Plants that have been used for decades in folk and traditional medicine have been accepted as one of the commonest sources of discovered natural agents of cancer chemotherapy and chemoprevention. The aim was to study the antioxidant and chemopreventive effects of Strobilanthes crispus on colorectal cancer formation. Five groups of rats were injected subcutaneously with AOM, 15 mg/kg body weight, each once weekly for 2 weeks. The cancer group was continued on 10 % Tween-20 feeding for 8 weeks. The standard drug group was continued on 35 mg/kg 5-fluorouracil intraperitoneal injection twice a week for 8 weeks, and the experimental groups were continued on 250 and 500 mg/kg S. crispus extract oral feeding for 8 weeks, respectively. The normal group was injected subcutaneously with normal saline once a week for 2 weeks, followed by oral administration of 10 % Tween-20 for 8 weeks. All the rats were sacrificed after 10 weeks. The colons were evaluated grossly and histopathologically for aberrant crypt foci (ACF). Gene expression was performed for Bax, Bcl2, Defa24, Slc24a3, and APC genes by real-time PCR. S. crispus and its fractions were evaluated for their chemopreventive effects against human colorectal adenocarcinoma cell line HT29 and cytotoxicity for normal human colon epithelial cell line CCD 841, and the active fraction was assessed for its components. We observed significant decrease in total colonic ACF formation, malonaldehyde (MDA) and lactate dehydrogenase (LDH), increase in superoxide dismutase (SOD), up-regulation of APC, Bax and Slc24a3, and down-regulation of Defa24 and Bcl-2 in rats treated with Strobilanthes

  19. Ozonation and Thermal Pre-Treatment of Municipal Sewage Sludge-Implications for Toxicity and Methane Potential

    DEFF Research Database (Denmark)

    Davidsson, A.; Eriksson, Eva; Fick, J.

    2013-01-01

    The aim of this study was to determine effects on methane potential and overall sludge quality from two different sludge pre-treatment technologies (ozonation high/low dosage and thermal treatment 55/70 degrees C). In general both treatments produced increased methane potential. Thermal treatment...

  20. Biotic factors in induced defence revisited: cell aggregate formation in the toxic cyanobacterium Microcystis aeruginosa PCC 7806 is triggered by spent Daphnia medium and disrupted cells

    NARCIS (Netherlands)

    Becker, S.

    2010-01-01

    Bioassays with the toxic cyanobacterium Microcystis aeruginosa PCC 7806, its non-toxic mutant ΔmcyB, and Daphnia magna as grazer were used to evaluate biotic factors in induced defence, in particular cyanobacterial and grazer-released info-chemicals. Three main questions were addressed in this

  1. Fluorescent Dye Encapsulated ZnO Particles with Cell-specific Toxicity for Potential use in Biomedical Applications

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hua [Boise State Univ., ID (United States); Wingett, Denise [Boise State Univ., ID (United States); Mountain States Tumor and Medical Research Inst., Boise, ID (United States); Engelhard, Mark H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Feris, Kevin [Boise State Univ., ID (United States); Reddy, K. M. [Boise State Univ., ID (United States); Turner, Paul [Boise State Univ., ID (United States); Layne, Janet [Boise State Univ., ID (United States); Hanley, Cory [Boise State Univ., ID (United States); Bell, Jason [Boise State Univ., ID (United States); Tenne, Dmitri [Boise State Univ., ID (United States); Wang, Chong M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Punnoose, Alex [Boise State Univ., ID (United States); Indian Inst. of Science, Bangalore (India)

    2008-07-24

    Fluorescein isothiocyanate (FITC)-encapsulated core-shell particles with a nanoscale ZnO finishing layer have been synthesized for the first time as multifunctional “smart” nanostructures for particle tracking and cell imaging using the visible fluorescence emission of the dye or UV fluorescence emission of ZnO, and anti-cancer/antibacterial treatments using the selective toxicity of the nanoscale ZnO outer surface. The chemical phase composition, morphology, size, and the layered core-shell architecture of the particles were characterized using detailed transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and UV-vis-NIR spectrophotometry. Systematic XPS studies after removing nanometer thick layers confirmed the expected layered structure in the order ZnO-SiO2-APTMS-FITC proceeding from the surface to the core of the ~200 nm sized particles. Detailed investigation of the fluorescence properties of these hydrophilic particles in bio-compatible media using fluorescence spectroscopy, flow cytometry and fluorescence confocal microscopy demonstrated that the silica/ZnO outer layer offers considerable protection to the encapsulated dye molecules from photobleaching and quenching due to reactive species such as oxygen in the solvent. These particles showed promise toward cell imaging, for example when the bacterium Escherichia coli was used as a test system, the green fluorescence of the particles allowed confocal microscopy to image the cells. The FITC encapsulated ZnO (FITC-ZnO) particles demonstrated excellent selectivity in preferentially killing Jurkat cancer cells (18% cell viability) without any significant toxicity to normal primary immune cells (75% cell viability) at 60 μg/mL concentrations and inhibited the growth of both gram-positive and gram negative bacteria at concentrations ≥ 250-500 μg/mL (for Staphylococcus aureus and Escherichia coli, respectively). These results indicate that the

  2. Positron scattering by atomic hydrogen using optical potentials and with positronium formation

    International Nuclear Information System (INIS)

    Walters, H.R.J.

    1990-01-01

    The scattering is considered of positrons by H(ls) in a two-state model which incorporates optical potentials. The model explicitly describes elastic scattering, i.e., positron + H(ls) yields positron + H(ls) and Ps(ls) yields Ps(ls) + p. The inelastic processes positron + H(ls) yields positron + H* Ps(ls) + p yields Ps* + p where * stands for a state other than ls, are implicitly taken into account through the optical potentials, which also allow for polarization of H(ls) and Ps(ls)

  3. Beyond platinum: synthesis, characterization, and in vitro toxicity of Cu(II-releasing polymer nanoparticles for potential use as a drug delivery vector

    Directory of Open Access Journals (Sweden)

    Harris Alesha

    2011-01-01

    Full Text Available Abstract The field of drug delivery focuses primarily on delivering small organic molecules or DNA/RNA as therapeutics and has largely ignored the potential for delivering catalytically active transition metal ions and complexes. The delivery of a variety of transition metals has potential for inducing apoptosis in targeted cells. The chief aims of this work were the development of a suitable delivery vector for a prototypical transition metal, Cu2+, and demonstration of the ability to impact cancer cell viability via exposure to such a Cu-loaded vector. Carboxylate-functionalized nanoparticles were synthesized by free radical polymerization and were subsequently loaded with Cu2+ via binding to particle-bound carboxylate functional groups. Cu loading and release were characterized via ICP MS, EDX, XPS, and elemental analysis. Results demonstrated that Cu could be loaded in high weight percent (up to 16 wt.% and that Cu was released from the particles in a pH-dependent manner. Metal release was a function of both pH and the presence of competing ligands. The toxicity of the particles was measured in HeLa cells where reductions in cell viability greater than 95% were observed at high Cu loading. The combined pH sensitivity and significant toxicity make this copper delivery vector an excellent candidate for the targeted killing of disease cells when combined with an effective cellular targeting strategy.

  4. Eco-friendly control of the poultry red mite, Dermanyssus gallinae (Dermanyssidae), using the α-thujone-rich essential oil of Artemisia sieberi (Asteraceae): toxic and repellent potential.

    Science.gov (United States)

    Tabari, Mohaddeseh Abouhosseini; Youssefi, Mohammad Reza; Benelli, Giovanni

    2017-05-01

    The poultry red mite, Dermanyssus gallinae, represents a key threat for the poultry industry worldwide. The control of D. gallinae is mainly achieved by continuous applications of acaricides. However, the fast-growing development of resistance, and the strict laws concerning chemicals admitted for treatments on food animals, highlighted the importance of alternative control tools. Here, we explored the potential of Artemisia sieberi essential oil against D. gallinae. In this study, the A. sieberi essential oil was analyzed using GC and GC-MS. The oil toxicity through contact and fumigant assays on adult mites was evaluated. The oil repellent activity was assessed on adult mites over different time intervals. Lastly, the residual toxicity of various doses of the oil was evaluated on D. gallinae until 14 days post treatment. GC and GC-MS showed that the oil was rich in α-thujone (31.5%), β-thujone (11.92%), camphor (12.3%), and 1,8-cineole (10.09%). Contact toxicity on adult mites showed 50% lethal concentration (LC 50 ), LC 90 , and LC 99 of 15.85, 26.63, and 35.42 μg/cm 3 , respectively. In fumigant assays, the oil was toxic on D. gallinae, and mortality was significantly higher in open containers over closed ones, underlining the key role of highly volatile constituents. Repellent assays showed that after 24 h from the treatment, all doses of the A. sieberi essential oil led to significant repellent activity over the control, except for 2 μg/cm 3 . After 48 h, A. sieberi essential oil tested at all doses led to significant repellent activity, if compared to the control. Residual toxicity assays showed that time exposure and concentration tested had a significant impact on mite mortality after 1, 2, 5, and 7 days from the treatment. Notably, mortality remained significantly higher over the control for 7 days after spraying with oil at 2%. Further field assays with selected molecules from the A. sieberi essential oil are ongoing, testing them in

  5. Primary pollutants and potential photochemical smog formation in Makkah, Saudi Arabia

    International Nuclear Information System (INIS)

    Nasralla, M.M.; Seroji, A.R.

    2007-01-01

    This study was conducted in Mina Valley and the central district of the holy city, Makkah, during the pilgrimage (Hajj) season of 1424 Hijri (2004). During this season, more than 2.5 million people gathered in Makkah to perform the Hajj rituals. Two mobile air pollution laboratories were used to monitor NO, NO2, NOx, non-methane hydrocarbons and ozone (O3) in the atmosphere in Mina and Makkah. Instruments were calibrated periodically against standard gases. The present investigation showed clearly an ideal diurnal cycle of local ozone formation. Although the intensity of the incoming UV radiation was the lowest compared with other months of the year, recorded ozone levels approached the maximum allowable levels of 150 ug/m3 in Mina, and exceeded 160 ug/m3 in Makkah during the pilgrimage period. The problem was intensified by the high record levels NOx, sometimes reaching more than 800 ug/m3, 1h average, coupled with 1h average concentration of about 3 ppm non-methane hydrocarbons. Furthermore, the average maximum hourly ozone concentrations increased gradually from less than 60 ug/m3 during February to reach more than 200 ug/m3 (as an indication of smog formation) during some days of May. This coincides with the increase in the intensity of the incoming UV radiation reaching its maximum level in May. Consequently, it can be concluded that Makkah may face severe air pollution episodes when the pilgrimage season shifts to the summer months in the next few years. This may pose acute health problems for the elderly people and those with respiratory health problems. Good air quality and transportation management as well as the use of alternative clean fuel are highly recommended. (author)

  6. [Stevens-Johnson syndrome and toxic epidermal necrolysis (SJSTEN) related to insecticide: Second case in the literature and potential implications].

    Science.gov (United States)

    Moullan, M; Ahossi, V; Zwetyenga, N

    2016-06-01

    Stevens-Johnson syndrome and toxic epidermal necrolysis (SJSTEN) is a rare acute drug reaction characterized by the brutal destruction of the superficial layer of the skin and mucosa. SJSTEN is favoured by some drugs (90 % of cases) and genetic factors. It occurs at any age in both sexes. The pathophysiology is not completely understood. To our knowledge, only one case linked to an insecticide has been described. We present the second case involving a combination of lambdacyhalothrin and thiamethoxam. A 34-year-old farmer was admitted in emergency for a severe allergic reaction occurring few days after the use of an insecticide to treat his field with no particular precaution. The disease progression was swift: deterioration of general condition, generalized itching, blisters, bubbles, hyperthermia, tachycardia, significant oral pain and oral lesions and dysphagia. Hands, feet were concerned and external genitalia was responsible for burning urination. Oral lesions have rapidly evolved from edema to infected lesions. The diagnosis of SJSTEN was confirmed by histopathology. After complete assessment and adequate treatment, the patient was discharged after 17 days of hospitalization. The etiological research concluded to a probable poisoning by lambdacyhalothrin and thiamethoxam. This is the second published case of a SJSTEN linked to an insecticide combining lambdacyhalothrin and thiamethoxam. Manufacturers, users, regulators and physicians should take these data into account. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  7. Cancer ameliorating potential of Phyllanthus amarus: In vivo and in vitro studies against Aflatoxin B1 toxicity

    Directory of Open Access Journals (Sweden)

    Md. Sultan Ahmad

    2015-10-01

    Conclusion: Ameliorating potential of P. amarus was dose and duration dependant. These extracts significantly reduced the mutagenicity and genotoxicity that were produced due to AFB1 treatment both in vitro and in vivo.

  8. Importance of inorganic geochemical characteristics on assessment of shale gas potential in the Devonian Horn River Formation of western Canada

    Science.gov (United States)

    Hong, Sung Kyung; Shinn, Young Jae; Choi, Jiyoung; Lee, Hyun Suk

    2017-04-01

    The gas generation and storage potentials of shale has mostly been assessed by original TOC (TOCo) and original kerogen type. However, in the Horn River Formation, organic geochemical tools and analysis are barely sufficient for assessing the TOCo and original kerogen type because residual carbon contents represent up to 90% of TOC in shales. Major and trace elements are used as proxies for the bottom water oxygen level, for terrestrial sediment input and for productivity, which is related with variation of kerogen type. By using the inorganic geochemical proxies, we attempt to assess original kerogen type in shale gas formation and suggest its implication for HIo (original Hydrogen Index) estimation. The estimated HIo in this study allows us to calculate a reliable TOCo. These results provide new insights into the accurate estimation of the hydrocarbon potential of shale gas resources. The inorganic geochemical proxies indicate vertical variations of productivity (EX-SiO2 and Baauth), terrestrial sediment input (Al2O3, Zr, Hf, and Nb) and oxygen content in bottom water during deposition (Moauth, Uauth and Th/U), which represent the temporal changes in the mixing ratio between Type II and III kerogens. The Horn River Formation has different HIo values calculated from EX-SiO2 (biogenic origin) and it is ranked by HIo value in descending order: Evie and Muskwa members (500-700 mgHC/gTOC) > middle Otterpark Member (400-500 mgHC/gTOC) > upper Otterpark Member (300-400 mgHC/gTOC) > lower Otterpark Member (200 mgHC/gTOC). Based on the original kerogen type and TOCo, the gas generation and storage potentials of the Evie, middle Otterpark and Muskwa members are higher than those of other members. The source rock potential is excellent for the Evie Member with a remarkable difference between TOCo and measured TOC.

  9. FORMATION OF NITRO MUSK ADDUCTS OF RAINBOW TROUT HEMOGLOBIN FOR POTENTIAL USE AS BIOMARKERS OF EXPOSURE

    Science.gov (United States)

    The high use of nitro musk xylene (MX) and musk ketone (MK) as fragrances, and their persistence and bioaccumulation potential make them ubiquitous environmental contaminants. The 4-amino-MX (AMX) and 2-amino-MK (AMK) metabolites have been detected in trout fish hemoglobin (Hb) s...

  10. Potential origin and formation for molecular components of humic acids in soils

    Science.gov (United States)

    Hatcher, Patrick; DiDonato, Nicole; Waggoner, Derek

    2016-04-01

    Humification is defined as the process by which plant and microbial debris are transformed in to humic substances. Proposed pathways for the formation of humic substances, include the lignin and lignin decomposition theories, the lignin-polyphenol theory as well as the melanoidin pathway. It is generally accepted that a combination of several of these pathways with some modifications may be responsible for producing humic substances. The current study examines humic acids from numerous soil samples to demonstrate their molecular composition. In addition we provide an explanation for the formation of these molecules that introduces a new perspective of the humification process. Our work utilizes advanced analytical techniques such as ESI-FTICR-MS and solid state NMR to more completely characterize humic acids at the molecular level. Methods Humic acids were extracted from soils using 0.5 M NaOH followed by treatment with a Dowex™ ion-exchange resin to remove sodium ions. Solid State 13C NMR spectra were obtained on a Bruker 400 MHz Avance II spectrometer equipped with a 4 mm solid state MAS probe. ESI-FTICR-MS analysis was conducted in the negative ion mode on a Bruker Daltonics 12 Tesla Apex Qe FTICR-MS instrument equipped with an Apollo II ESI source. Results: Soil humic acids from numerous soils were investigated in this study. The molecular formulas calculated from ultrahigh resolution mass spectra of well humified soils fall clearly into two predominant regions consisting of condensed aromatic molecules as well as high H/C, low O/C carboxyl-containing aliphatic molecules (CCAM). In contrast, the spectral data for humic acids from a poorly humified spodosol soil show a less dramatic separation of these regions, with relatively more mol