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Mercury
Kinds of Mercury Terms modified by Mercury Selected AbstractsMONEY FLOWS LIKE MERCURY: THE GEOGRAPHY OF GLOBAL FINANCEGEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 2 2005Gordon L Clark ABSTRACT. If the social relations and inherited configuration of production were at the core of economic geography a decade ago, these aspects of the world are increasingly taken for granted. The global scope of industry and corporate strategy has claimed increasing attention over the past decade. And while any ,new' economic geography must have something to say about the nature of human agency and the role of institutions in structuring the landscape, care must be taken not to exaggerate their significance for constructive interaction. In point of fact, the global finance industry is an essential lens through which to study contemporary capitalism from the top-down and the bottom-up. If we are to understand the economic landscape of twenty-first century capitalism, it should be understood through global financial institutions, its social formations and investment practices. This argument is developed by reference to the recent literature on the geography of finance and a metaphor , money flows like mercury , designed to explicate the spatial and temporal logic of global capital flows. Some may dispute this argument, but in doing so they lament the passing of an era rather than advancing a convincing counterclaim about how the world is and what it might become. All this means that we have to rethink the significance of geographical scale and organizational processes as opposed to an unquestioned commitment to localities. [source] MERCURY IN WATER AND SEDIMENT OF STEAMBOAT CREEK, NEVADA: IMPLICATIONS FOR STREAM RESTORATION,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 4 2001Mitchell Blum ABSTRACT: The objective of this study was to characterize the sources, concentrations, and distribution of total and methylmercury in water, and channel and bank sediments of Steamboat Creek, Nevada. This information was needed to begin to assess the potential impacts of stream restoration on mercury pollution in this tributary to the Truckee River. The Truckee River flows into Pyramid Lake, a terminal water body home to one endangered and one threatened fish species, where stable pollutants will accumulate over time. Mercury in Steamboat Creek was originally derived from its headwaters, Washoe Lake, where several gold and silver mills that utilized mercury were located. In the 100 plus years since ore processing occurred, mercury-laden alluvium has been deposited in the stream channel and on streambanks where it is available for remobilization. Total mercury concentrations measured in unfiltered water from the creek ranged from 82 to 419 ng/L, with greater than 90 percent of this mercury being particle-bound (> 0.45 (m). Mercury in sediments ranged from 0.26 to 10.2 pg/g. Methylmercury concentrations in sediments of Steamboat Creek were highest in wetlands, lower in the stream channel, and still lower in streambank settings. Methylmercury concentrations in water were 0.63 to 1.4 ng/L. A streambank restoration plan, which includes alterations to channel geometry and wetland creation or expansion, has been initiated for the creek. Data developed indicate that streambank stabilization could reduce the mercury loading to the Creek and that wetland construction could exacerbate methylmercury production. [source] Measuring the plasma environment at Mercury: The fast imaging plasma spectrometerMETEORITICS & PLANETARY SCIENCE, Issue 9 2002P. L. KOEHN Three primary populations of ions exist at Mercury: solar wind, magnetospheric, and pickup ions. These pickup ions are generated through the ionization of Mercury's exosphere or are sputtered particles from the Mercury surface. A comprehensive mission to Mercury, such as MESSENGER (MErcury: Surface, Space ENvironment, GEochemistry, Ranging), should include a sensor that is able to determine the dynamical properties and composition of all these plasma components. An instrument to measure the composition of these ion populations and their three-dimensional velocity distribution functions must be lightweight, fast, and have a very large field of view. The fast imaging plasma spectrometer (FIPS) is an imaging mass spectrometer, part of NASA's MESSENGER mission, the first Mercury orbiter. This versatile instrument has a very small footprint, and has a mass that is ,1 order of magnitude less than other comparable systems. It maintains a nearly full-hemisphere field of view, suitable for either spinning or three-axis-stabilized platforms. The major piece of innovation to enable this sensor is a new deflection system geometry that enables a large instantaneous (,1.5,) field of view. This novel electrostatic analyzer system is then combined with a position sensitive time-of-flight system. We discuss the design and prototype tests of the FIPS deflection system and show how this system is expected to address one key problem in Mercury science, that of the nature of the radar-bright regions at the Hermean poles. [source] Electrochemical Determination of Manganese Solubility in Mercury via Amalgamation and Stripping in the Room Temperature Ionic Liquid n -Hexyltriethylammonium Bis(trifluoromethanesulfonyl)imide, [N6,2,2,2][NTf2]ELECTROANALYSIS, Issue 24 2008Abstract The solubility of manganese in mercury was determined electrochemically via amalgamation and stripping in the room temperature ionic liquid n -hexyltriethylammonium bis(trifluoromethanesulfonyl)imide, [N6,2,2,2][NTf2]. A hemispherical mercury electrode was made by electrodepositing mercury onto a planar platinum microelectrode. Cyclic voltammetry of Mn2+ in [N6,2,2,2][NTf2] at the mercury microhemisphere electrode was investigated at temperatures of 298, 303 and 313,K. The solubility of Mn in Hg was determined on the basis of the charge under the reduction peak (Mn2+,Mn0) and the corresponding reoxidation. [source] Voltammetric Determination of Mercury(II) at Poly(3-hexylthiophene) Film Electrode.ELECTROANALYSIS, Issue 24 2007Effect of Halide Ions Abstract The well-known method for the determination of mercury(II), which is based on the anodic stripping voltammetry of mercury(II), has been adapted for applications at the thin film poly(3-hexylthiophene) polymer electrode. Halide ions have been found to increase the sensitivity of the mercury response and shift it more positive potentials. This behavior is explained by formation of mercuric halide which can be easily deposited and stripped from the polymer electrode surface. The procedure was optimized for mercury determination. For 120,s accumulation time, detection limit of 5,ng mL,1 mercury(II) has been observed. The relative standard deviation is 1.3% at 40,ng mL,1 mercury(II). The performance of the polymer film studied in this work was evaluated in the presence of surfactants and some potential interfering metal ions such as cadmium, lead, copper and nickel. [source] Cytogenetic status in newborns and their parents in Madrid: The BioMadrid studyENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 4 2010Virginia Lope Abstract Monitoring cytogenetic damage is frequently used to assess population exposure to environmental mutagens. The cytokinesis-block micronucleus assay is one of the most widely used methods employed in these studies. In the present study we used this assay to assess the baseline frequency of micronuclei in a healthy population of father-pregnant woman-newborn trios drawn from two Madrid areas. We also investigated the association between micronucleus frequency and specific socioeconomic, environmental, and demographic factors collected by questionnaire. Mercury, arsenic, lead, and cadmium blood levels were measured by atomic absorption spectrometry. The association between micronucleated cell frequency and the variables collected by questionnaire, as well as, the risk associated with the presence of elevated levels of metals in blood, was estimated using Poisson models, taking the number of micronucleated cells in 1,000 binucleated cells (MNBCs) as the dependent variable. Separate analyses were conducted for the 110 newborns, 136 pregnant women, and 134 fathers in whom micronuclei could be assessed. The mean number of micronucleated cells per 1,000 binucleated cells was 3.9, 6.5, and 6.1 respectively. Our results show a statistically significant correlation in MNBC frequency between fathers and mothers, and between parents and newborns. Elevated blood mercury levels in fathers were associated with significantly higher MNBC frequency, compared with fathers who had normal mercury levels (RR:1.21; 95%CI:1.02,1.43). This last result suggests the need to implement greater control over populations which, by reason of their occupation or life style, are among those most exposed to this metal. Environ. Mol. Mutagen., 2010. © 2009 Wiley-Liss, Inc. [source] Mercury binding on activated carbonENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 4 2006Bihter Padak Abstract Density functional theory has been employed for the modeling of activated carbon (AC) using a fused-benzene ring cluster approach. Oxygen functional groups have been investigated for their promotion of effective elemental mercury binding on AC surface sites. Lactone and carbonyl functional groups yield the highest mercury binding energies. Further, the addition of halogen atoms has been considered to the modeled surface, and has been found to increase the AC's mercury adsorption capacity. The mercury binding energies increase with the addition of the following halogen atoms, F > Cl > Br > I, with the fluorine addition being the most promising halogen for increasing mercury adsorption. © 2006 American Institute of Chemical Engineers Environ Prog, 2006 [source] Mercury in canned tuna: The importance of seleniumENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2010Nicholas V.C. Ralston No abstract is available for this article. [source] Mercury-induced reproductive impairment in fish,,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2009Kate L. Crump Abstract Mercury is a potent neurotoxin, and increasing levels have led to concern for human and wildlife health in many regions of the world. During the past three decades, studies in fish have examined the effects of sublethal mercury exposure on a range of endpoints within the reproductive axis. Mercury studies have varied from highly concentrated aqueous exposures to ecologically relevant dietary exposures using levels comparable to those currently found in the environment. This review summarizes data from both laboratory and field studies supporting the hypothesis that mercury in the aquatic environment impacts the reproductive health of fish. The evidence presented suggests that the inhibitory effects of mercury on reproduction occur at multiple sites within the reproductive axis, including the hypothalamus, pituitary, and gonads. Accumulation of mercury in the fish brain has resulted in reduced neurosecretory material, hypothalamic neuron degeneration, and alterations in parameters of monoaminergic neurotransmission. At the level of the pituitary, mercury exposure has reduced and/or inactivated gonadotropin-secreting cells. Finally, studies have examined the effects of mercury on the reproductive organs and demonstrated a range of effects, including reductions in gonad size, circulating reproductive steroids, gamete production, and spawning success. Despite some variation between studies, there appears to be sufficient evidence from laboratory studies to link exposure to mercury with reproductive impairment in many fish species. Currently, the mechanisms underlying these effects are unknown; however, several physiological and cellular mechanisms are proposed within this review. [source] Contaminant-associated alteration of immune function in black-footed albatross (Phoebastria nigripes), a North Pacific predatorENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2007Myra E. Finkelstein Abstract Environmental pollution is ubiquitous and can pose a significant threat to wild populations through declines in fitness and population numbers. To elucidate the impact of marine pollution on a pelagic species, we assessed whether toxic contaminants accumulated in black-footed albatross (Phoebastria nigripes), a wide-ranging North Pacific predator, are correlated with altered physiological function. Blood samples from adult black-footed albatrosses on Midway Atoll, part of the Hawaiian (USA) archipelago, were analyzed for organochlorines (e.g., polychlorinated biphenyls [PCBs] and chlorinated pesticides), trace metals (silver, cadmium, tin, lead, chromium, nickel, copper, zinc, arsenic, selenium, and total mercury), and a sensitive physiological marker, peripheral white blood cell immune function (mitogen-induced lymphocyte proliferation and macrophage phagocytosis). We found a positive significant relationship between organochlorines, which were highly correlated within individual birds (p < 0.001, r > 0.80, Spearman correlation for all comparisons; PCBs, 160 ± 60 ng/ml plasma [mean ± standard deviation]; DDTs, 140 ± 180 ng/ml plasma; chlordanes, 7.0 ± 3.6 ng/ml plasma; hexachlorobenzene, 2.4 ± 1.5 ng/ml plasma; n = 15) and increased lymphocyte proliferation (p = 0.020) as well as percentage lymphocytes (p = 0.033). Mercury was elevated in black-footed albatrosses (4,500 ± 870 ng/ml whole blood, n = 15), and high mercury levels appeared to be associated (p = 0.017) with impaired macrophage phagocytosis. The associations we documented between multiple contaminant concentrations and immune function in endangered black-footed albatrosses provide some of the first evidence that albatrosses in the North Pacific may be affected by environmental contamination. Our results raise concern regarding detrimental health effects in pelagic predators exposed to persistent marine pollutants. [source] Influence of feeding ecology on blood mercury concentrations in four species of turtlesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 8 2007Christine M. Bergeron Abstract Mercury is a relatively well-studied pollutant because of its global distribution, toxicity, and ability to bioaccumulate and biomagnify in food webs; however, little is known about bioaccumulation and toxicity of Hg in turtles. Total Hg (THg) concentrations in blood were determined for 552 turtles representing four different species (Chelydra serpentina, Sternotherus odoratus, Chrysemys picta, and Pseudemys rubriventris) from a Hg-contaminated site on the South River (VA, USA) and upstream reference sites. Methylmercury and Se concentrations also were determined in a subset of samples. Because the feeding ecology of these species differs drastically, stable isotopes of carbon (,13C) and nitrogen (,15N) were employed to infer the relationship between relative trophic position and Hg concentrations. Significant differences were found among sites and species, suggesting that blood can be used as a bioindicator of Hg exposure in turtles. We found differences in THg concentrations in turtles from the contaminated site that were consistent with their known feeding ecology: C. serpentina , S. odoratus > C. picta > P. rubriventris. This trend was generally supported by the isotope data, which suggested that individual turtles were feeding at more than one trophic level. Methylmercury followed similar spatial patterns as THg and was the predominant Hg species in blood for all turtles. Blood Se concentrations were low in the system, but a marginally positive relationship was found between THg and Se when species were pooled. The blood THg concentrations for the turtles in the present study are some of the highest reported in reptiles, necessitating further studies to investigate potential adverse effects of these high concentrations. [source] Acute and chronic toxicity of mercury to early life stages of the rainbow mussel, Villosa iris (Bivalvia: Unionidae)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2005Theodore W. Valenti Abstract Mercury (Hg) contamination is receiving increased attention globally because of human health and environmental concerns. Few laboratory studies have examined the toxicity of Hg on early life stages of freshwater mussels, despite evidence that glochidia and juvenile life stages are more sensitive to contaminants than adults. Three bioassays (72-h acute glochidia, 96-h acute juvenile, and 21-d chronic juvenile toxicity tests) were conducted by exposing Villosa iris to mercuric chloride salt (HgCl2). Glochidia were more sensitive to acute exposure than were juvenile mussels, as 24-, 48-, and 72-h median lethal concentration values (LC50) for glochidia were >107, 39, and 14 ,g Hg/L, respectively. The 24-, 48-, 72-, and 96-h values for juveniles were 162, 135, 114, and 99 ,g Hg/L, respectively. In the chronic test, juveniles exposed to Hg treatments ,8 ,g/L grew significantly less than did control organisms. The substantial difference in juvenile test endpoints emphasizes the importance of assessing chronic exposure and sublethal effects. Overall, our study supports the use of glochidia as a surrogate life stage for juveniles in acute toxicity tests. However, as glochidia may be used only in short-term tests, it is imperative that an integrated approach be taken when assessing risk to freshwater mussels, as their unique life history is atypical of standard test organisms. Therefore, we strongly advocate the use of both glochidia and juvenile life stages for risk assessment. [source] Organochlorine pesticides and mercury in cottonmouths (Agkistrodon piscivorus) from northeastern Texas, USA,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2005Thomas R. Rainwater Abstract Dspite their ecological importance andglobal decline, snakes remain poorly studied in ecotoxicology. In this study, we examined organochlorine (OC) pesticide and mercury accumulation in cottonmouths (Agkistrodon piscivorus) living on a contaminated site in northeastern Texas (USA). Mercury and p,p,-dichlorodiphenyldichloroethylene (p,p,-DDE) were detected in all snakes examined. Other OCs, including p,p,-dichlorodiphenyltrichloroethane (p,p,-DDT), methoxychlor, aldrin, and heptachlor, also were detected, but less frequently. Concentrations of p,p,-DDE were higher in fat than in liver, while mercury concentrations were highest in liver, followed by kidney and tail clips. One animal contained the highest mercury concentration yet reported for a snake (8,610 ng/g). Mercury concentrations in liver and kidney were higher in males than females, while no intersex differences in p,p,-DDE concentrations were observed. Concentrations of p,p,-DDE in fat were correlated positively with body size in male cottonmouths but not females, suggesting a slower rate of accumulation in females. Body size strongly predicted mercury concentrations in liver, kidney, and tail clips of both sexes. Tail clips were strong predictors of mercury in liver and kidney in males but not females, suggesting possible sex-dependent differences in mercury toxicokinetics. Both long-term field studies and controlled laboratory investigations are needed to adequately assess the response of cottonmouths to chronic contaminant exposure. [source] Reproductive and transgenerational effects of methylmercury or Aroclor 1268 on Fundulus heteroclitusENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2001Mary Baker Matta Abstract This research determined the potential for methylmercury or Aroclor 1268 to disrupt reproduction and sexual differentiation in Fundulus heteroclitus. The research determined whether fish that are exposed to mercury or Aroclor 1268 survive and successfully reproduce; whether offspring of exposed fish hatch, survive, produce eggs, and fertilize them; and whether the secondgeneration offspring of exposed fish hatch and survive. Fundulus heteroclitus were exposed to mercury or Aroclor 1268 via contaminated food. Endpoints evaluated included survival, growth, fecundity, fertilization success, hatch success, larval survival, sex ratios, and the prevalence of gonadal abnormalities. In general, polychlorinated biphenyls were highly bioavailable and accumulated well through feeding. The only statistically significant effect observed as a result of treatment with Aroclor 1268 was an increase in growth in the offspring of exposed fish. Mercury was accumulated in a dose-dependent fashion via food exposures. Exposure to mercury in food increased mortality in male F. heteroclitus, which possibly occurred as a result of behavioral alterations. Increased mortality was observed at body burdens of 0.2 to 0.47 ,g/g. Offspring of F. heteroclitus fed mercury-contaminated food were less able to successfully reproduce, with reduced fertilization success observed at egg concentrations of 0.01 to 0.63 ,g/g, which corresponds with parent whole-body concentrations of 1.1 to 1.2 ,g/g. Offspring of exposed fish also had altered sex ratios, with treatment at moderate concentrations producing fewer females and treatment at the highest concentration producing more females than expected. Alterations in sex ratios were observed at concentrations of less than 0.01 ,g/g in eggs or between 0.44 and 1.1 ,g/g in parents. Offspring of mercury-exposed fish also had increased growth in moderate treatments, when egg concentrations were less than 0.02 ,g/g, or when parent whole bodies contained 0.2 to 0.47 ,g/g. In summary, exposure to mercury reduced male survival, reduced the ability of offspring to successfully reproduce, and altered sex ratios in offspring. Both direct effects on exposed fish and transgenerational effects were observed. [source] Dietary intake of differently fed salmon: a preliminary study on contaminantsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 3 2006C. Bethune Abstract Background, In a previous study, a group of coronary heart disease (CHD) patients exhibited positive cardioprotective effects of fatty acids derived from a diet of farmed Atlantic salmon fed fish oil (Seierstad et al. 2005). This follow-up study examines these patients for plasma exposure to selected organic and inorganic contaminants found in seafood that may detract from the benefits of eating oily fish. Methods, The study design was from Seierstad et al. (2005), where 58 patients were allocated into three groups consuming 700 g week,1 of differently fed Atlantic salmon (Salmo salar) fillets for 6 weeks: 100% fish oil (FO), 100% rapeseed oil (RO), or 50% of each (FO/RO). Results, Different fillets showed graded levels (FO > FO/RO > RO) of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (DLPCBs), indicator PCBs, polybrominated diphenyl ethers (PBDEs), and arsenic (As). Mercury (Hg) and lead (Pb) levels were similar across the three types of fillets. After 6 weeks of consumption, patient levels of PCDDs, DLPCBs, and PCBs in plasma decreased as the dietary intake of these contaminants increased. Plasma PBDEs only showed increases for the FO patients. Levels of inorganic contaminants in plasma showed only slight changes over the study period. Conclusions, These results show a reduction in the use of marine oils in fish feed reduces organic contaminant levels in farmed salmon while still providing a good dietary source of marine fatty acids. [source] Reaction of Mercury(0) with the I2 Adduct of Tetraphenyldithioimidodiphosphinic Acid (SPPh2)2NH (HL) , Crystal Structures of [Hg(HL)I2] and HgL2EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 23 2004M. Carla Aragoni Abstract The complex [Hg(HL)I2] (1) has been synthesised by reacting liquid Hg(0) in Et2O under mild reaction conditions with the I2 adduct of HL, HL·I2, while HgL2 (2) has been obtained from the reaction of compound 1 with HL in CH3CN. A single-crystal X-ray investigation of 1 shows four independent molecules in the asymmetric unit, each of which contains an HgII ion coordinated to two iodine atoms and two sulfur atoms of one bidentate neutral ligand in a distorted tetrahedral coordination geometry. Compound 2 consists of two anionic ligands coordinated to an HgII ion, which again displays a distorted tetrahedral coordination sphere. The reaction of 2 with HI (55 wt.-% in water) affords [Hg(HL)2](I)2 (3). Compounds 1, 2, and 3 have been characterised by FT-IR and 31P NMR spectroscopy. Density functional calculations suggest that compound 3 should feature a distorted tetrahedral coordination around the metal centre, with unequal Hg,S bond lengths. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Quantitative Removal of Mercury(II) from Water Through Bulk Liquid Membranes by Lipophilic PolyaminesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 19 2006Nicoletta Spreti Abstract Transport of mercury(II) and copper(II) ions through bulk liquid membranes has been studied, the former because of its toxicity and wide distribution in the environment, the latter for comparative purposes. The abilities of two carriers, the known N,N, -bis[2-(hexadecylamino)ethyl]- N,N, -bis(hydroxyethyl)ethylenediamine (bis-HE16ED) and the new N,N,-bis(p -octyloxybenzyl)-3,6-dioxaoctane-1,8-diamine (bis- pODODA), to complex and transport the selected metal ions are reported. Bis-HE16ED is a good carrier for Cu2+ ions, but the high stability of the carrier/Hg2+ ion complex in the membrane results in a lack of its transport. On the other hand, the new carrier displays a very high efficiency in Hg2+ ion transport, effecting quantitative transfer of the metal ion into the receiving phase within 24 h, despite its chelating region being only slightly different from that in bis-HE16ED. The ability of bis- pODODA to transport 100,% of Hg2+ efficiently in consecutive cycles is also reported. This result provides a basis for future development of a decontamination process based on a carrier-mediated transport system. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] A view of extraterrestrial soilsEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 6 2009G. Certini Summary The nature of soils on celestial bodies other than Earth is a growing area of research in planetary geology. However, disagreement over the significance of these deposits arises, in part, through the lack of a unified concept and definition of soil in the literature. The pragmatic definition ,medium for plant growth' is taken by some to imply the necessity of biota for soil to exist, and has been commonly adopted in the planetary science community. In contrast, a more complex and informative definition is based on scientific theory: soil is the (bio)geochemically/physically altered material at the surface of a planetary body that encompasses surficial extraterrestrial telluric deposits. This definition is based on the premise that soil is a body that retains information about its environmental history and that it does not need the presence of life to form. Four decades of missions have gathered geochemical information regarding the surface of planets and bodies within the Solar System, and information is quickly increasing. Reviewing the current knowledge on properties of extraterrestrial regoliths, we conclude that the surficial deposits of Venus, Mars and our moon should be considered to be soils in a pedological sense, and that Mercury and some large asteroids are covered in mantles that are soil candidates. A key environmental distinction between Earth and other Solar System bodies is the presence of life, and because of this dissimilarity in soil-forming processes, it is reasonable to distinguish these (presently) abiotic soils as Astrosols. Attempts to provide detailed classifications of extraterrestrial soils are premature, given our poor current knowledge of the Universe, but they highlight the fact that Earth possesses almost-abiotic environments that lend themselves to providing more understanding about telluric bodies of the Solar System. "He found himself in the neighbourhood of the asteroids 325, 326, 327, 328, 329, and 330. He began, therefore, by visiting them, in order to add to his knowledge." (Excerpt from the The Little Prince by Antoine de Saint-Exupéry) [source] Mercury Biosensors: Polydiacetylene,Liposome Microarrays for Selective and Sensitive Mercury(II) Detection (Adv. Mater.ADVANCED MATERIALS, Issue 36 200936/2009) Polydiacetylene (PDA) liposome microarrays have been developed for selective and sensitive mercury detection. The sensors, reported on p. 3674 by Jinsang Kim and co-workers, are designed to produce red fluorescence emission upon binding with Hg2+; when the single-stranded DNA aptamers on the microarray selectively wrap around the mercury ions, the resulting complexes repulse each other. The epoxy-based PDA liposome design is an excellent universal platform that can be readily extended to other sensor designs. [source] Polydiacetylene,Liposome Microarrays for Selective and Sensitive Mercury(II) DetectionADVANCED MATERIALS, Issue 36 2009Jiseok Lee Polydiacetylene (PDA) liposome microarrays are developed for selective and sensitive mercury (Hg2+) detection. The PDA mercury sensors are designed to produce red fluorescence emission upon binding with Hg2+, when the ssDNA aptamers on the PDA surface recognize and wrap around mercury ions and the resulting bulky T-Hg-T complexes repulse each other. [source] Trapping Metallic Liquid Mercury in a Carbon Shell by the Decomposition of Dimethyl Mercury,ADVANCED MATERIALS, Issue 5 2008A. Gedanken An efficient single-step synthesis of mercury droplets covered with a carbon shell by the thermolysis of dimethyl mercury under its autogenic pressure is described. This is a unique case in which a liquid metal is trapped inside a nano- and micrometer size carbon capsule. The air-stability and the characterization by XRD, TEM, DSC, HRSEM, and HRTEM of this composite are reported. [source] Optical Detection of Mercury(II) in Aqueous Solutions by Using Conjugated Polymers and Label-Free Oligonucleotides,ADVANCED MATERIALS, Issue 11 2007X. Liu A conjugated-polymer-based "mix-and-detect" optical sensor for mercury ions is fabricated by using a water-soluble poly[3-(3,- N,N,N -triethylamino-1,-propyloxy)-4-methyl-2,5-thiophene hydrochloride] (PMNT) and a label-free, mercury-specific oligonucleotide (MSO) probe. PMNT binds to the Hg2+ -free MSO and the Hg2+,MSO complex in different ways, and exhibits distinguishable and specific optical responses to the target-induced conformation change. [source] Mercury CSD 2.0, new features for the visualization and investigation of crystal structuresJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 2 2008Clare F. Macrae The program Mercury, developed by the Cambridge Crystallographic Data Centre, is designed primarily as a crystal structure visualization tool. A new module of functionality has been produced, called the Materials Module, which allows highly customizable searching of structural databases for intermolecular interaction motifs and packing patterns. This new module also includes the ability to perform packing similarity calculations between structures containing the same compound. In addition to the Materials Module, a range of further enhancements to Mercury has been added in this latest release, including void visualization and links to ConQuest, Mogul and IsoStar. [source] Diphenyl diselenide protects against hematological and immunological alterations induced by mercury in miceJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 5 2008Ricardo Brandão Abstract Mercury is a heavy metal that can cause a variety of toxic effects on the organism, such as hematological and immunological alterations. In the present investigation, deleterious effects of mercury-intoxication in mice and a possible protective effect of diphenyl diselenide (PhSe)2 were studied. Male adult Swiss albino mice received daily a pretreatment with (PhSe)2 (15.6 mg/kg, orally) for 1 week. After this week, mice received daily mercuric chloride (1 mg/kg, subcutaneously) for 2 weeks. A number of hematological (erythrocytes, leukocytes, platelets, hemoglobin, hematocrit, reticulocytes, and leukocytes differential) and immunological (immunoglobulin G and M plasma concentration) parameters were evaluated. Another biomarker of tissue damage, lactate dehydrogenase (LDH), was also determined. The results demonstrated that mercury exposure caused a reduction in the erythrocyte, hematocrit, hemoglobin, leukocyte, and platelet counts and an increase in the reticulocyte percentages. (PhSe)2 was effective in protecting against the reduction in hematocrit, hemoglobin, and leukocyte levels. (PhSe)2 ameliorated reticulocyte percentages increased by mercury. However, (PhSe)2 was partially effective in preventing against the decrease in erythrocyte and platelet counts. Immunoglobulin G and M concentrations and LDH activity were increased by mercury exposure, and (PhSe)2 was effective in protecting against these effects. In conclusion, (PhSe)2 was effective in protecting against hematological and immunological alterations induced by mercury in mice. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:311,319, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20242 [source] Endogenous antioxidant defence system in rat liver following mercury chloride oral intoxicationJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 3 2005Inmaculada Bando Abstract Mercury is a highly toxic metal which induces oxidative stress. Superoxide dismutases, catalase, and glutathion peroxidase are proteins involved in the endogenous antioxidant defence system. In the present study rats were administered orally, by gavage, a single daily dose of HgCl2 for three consecutive days. In order to find a relation between the proteins involved in the antioxidant defence and mercury intoxication, parameters of liver injury, redox state of the cells, as well as intracellular protein levels and enzyme activities of Mn-dependent superoxide dismutase (MnSOD), Cu-Zn-dependent superoxide dismutase (CuZnSOD), catalase, and glutathione peroxidase (GPx) were assayed both in blood and in liver homogenates. HgCl2 at the doses of 0.1 mg/kg produced liver damage which that was detected by a slight increase in serum alanine aminotransferase and gamma glutamyl transferase. Hepatic GSH/GSSG ratio was assayed as a parameter of oxidative stress and a significant decrease was detected, as well as significant increases in enzyme activities and protein levels of hepatic antioxidant defence systems. Changes in both MnSOD and CuZnSOD were parallel to those of liver injury and oxidative stress, while the changes detected in catalase and GPx activities were progressively increased along with the mercury intoxication. Other enzyme activities related to the glutathione redox cycle, such as glutathione reductase (GR) and glucose-6-phosphate dehydrogenase (G6PDH), also increased progressively. We conclude that against low doses of mercury that produce a slight oxidative stress and liver injury, the response of the liver was to induce the synthesis and activity of the enzymes involved in the endogenous antioxidant system. The activities of all the enzymes assayed showed a rapidly induced coordinated response. © 2005 Wiley Periodicals, Inc. J Biochem Mol Toxicol 19:154,161, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20067 [source] Mercury stimulates rat liver glucocorticoid receptor association with Hsp90 and Hsp70JOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 5 2004Jelena Brklja Abstract The subject of the present study is the influence of mercury on association of rat liver glucocorticoid receptor (GR) with heat shock proteins Hsp90 and Hsp70. The glucocorticoid receptor heterocomplexes with Hsp90 and Hsp70 were immunopurified from the liver cytosol of rats administered with different doses of mercury. The amounts of co-immunopurified apo-receptor, Hsp90 and Hsp70 were then determined by quantitative Western blotting. The ratio between the amount of heat shock protein Hsp90 or Hsp70 and the amount of apo-receptor within immunopurified heterocomplexes was found to increase in response to mercury administration. On the other hand, the levels of Hsp90 and Hsp70 in hepatic cytosol remained unaltered. The finding that mercury stimulates association of the two heat shock proteins with the glucocorticoid receptor, rendering the cytosolic heat shock protein levels unchanged, suggests that mercury affects the mechanisms controlling the assembly of the receptor heterocomplexes. © 2004 Wiley Periodicals, Inc. J Biochem Mol Toxicol 18:257,260, 2004 Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20032 [source] Mercury removal: a physicochemical study of metal interaction with natural materialsJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 11 2009Leticia Carro Abstract BACKGROUND: Mercury is considered one of the most harmful heavy metals to the environment and human health, so recently remediation processes have been developed to eliminate this metal from wastewaters. Metal retention by natural polymers is a good alternative technique to remove heavy metals from solution. RESULTS: A screening of 25 potential mercury sorbents was carried out at three different pH values in order to find appropriate biomass to remove this metal from polluted waters. High sorption capacities were found for many of the materials studied. Four of these materials were selected for further detailed study. Kinetic studies showed short times to reach equilibrium. For S. muticum, sorption isotherms were obtained at several temperatures and a sorption enthalpy value was obtained. Desorption experiments were performed to determine the possibility for recycling of this brown alga. CONCLUSIONS: Different materials have been found to be potentially good adsorbents of mercury. A detailed study showed that S. muticum is an excellent material with a mercury uptake about 200 mg g,1. This brown alga has a fast kinetic process (80% of metal is removed from solution in 30 min), and very high metal uptake over a wide pH range, up to 92% elimination for pH values above 3,4. Copyright © 2009 Society of Chemical Industry [source] Partially Purified Collagen from Refiner Discharge of Pacific Whiting Surimi ProcessingJOURNAL OF FOOD SCIENCE, Issue 8 2005Jin Soo Kim ABSTRACT The physicochemical properties of acid-soluble collagen (ASC) from refiner discharge and the partially purified collagen (PPC) from both the refiner discharge and the fish skin were evaluated. Yield of collagen from refiner discharge was 34% higher in PPC than ASC. Mercury, lead, cadmium, and chromium contents of PPC from refiner discharge were not detected. There was no difference in the pattern of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) between ASC and PPC from refiner discharge. PPC from refiner discharge showed better functional properties than that from skin and was similar to ASC: whiteness, solubility, emulsifying activity, and cooking stability. Therefore, PPC from refiner discharge could be used as a new resource. [source] Phasing Out Cadmium, Lead, and MercuryJOURNAL OF INDUSTRIAL ECOLOGY, Issue 1 2009Effects on Urban Stocks, Flows Summary Large stocks of metals have accumulated in the urban technosphere (i.e., the physical environment altered by human activity). To minimize health and environmental risks, attempts were begun in the 1980s to phase out the use of cadmium (Cd), lead (Pb), and mercury (Hg). To study the effect of this attempt, we conducted substance flow analyses (SFAs) in Stockholm, Sweden, in 1995 and in 2002,2003, which allow a comparison of the results over time. The SFAs showed a reduction in the stocks of Cd and Hg by approximately 25% to 30% between 1995 and 2002,2003. For Pb, the stock development was more uncertain. Cd and Hg inflow was substantially reduced during this period, but Pb inflow increased. Amounts of Cd and Pb in waste were still large, whereas Hg flows in waste were decreasing. Furthermore, although emissions of Pb decreased, Cd and Hg emissions were in the same range as in 1995. The application of SFAs has provided unique data on the accumulation of metals in the Stockholm technosphere, thus serving as a valuable indicator of how the phasing out progresses. The changes can be related to regulations, initiatives by industries and organizations, and the proactive attitude of the local environmental authorities and of the water company. [source] Cement, Yogurt, and MercuryJOURNAL OF INDUSTRIAL ECOLOGY, Issue 3 2007Reid Lifset No abstract is available for this article. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||