Journal articles on the topic 'Mercury'
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1
CANNON, VERNON T., DELON W. BARFUSS, and RUDOLFS K. ZALUPS. "Molecular Homology and the Luminal Transport of Hg2+ in the Renal Proximal Tubule." Journal of the American Society of Nephrology 11, no. 3 (March 2000): 394–402. http://dx.doi.org/10.1681/asn.v113394.
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Abstract. The aim of this study was to define mechanisms involved in the luminal uptake of inorganic mercury in the kidney using isolated perfused straight (S2) segments of the proximal tubule. When mercuric conjugates of glutathione (GSH), cysteinylglycine, or cysteine (containing 203Hg2+) were perfused through the lumen, the rates of luminal disappearance flux (JD) of inorganic mercury were approximately 39, 53, and 102 fmol/min per mm, respectively. Thus, the rates of luminal uptake of mercury are greater when the mercury is in the form of a mercuric conjugate of cysteine than in the form of a mercuric conjugate of cysteinylglycine or GSH. Addition of acivicin to the perfusate, to inhibit activity of the γ-glutamyltransferase, caused significant reductions in the JD for mercury in tubules perfused with mercuric conjugates of GSH. Addition of cilastatin, an inhibitor of dehydropeptidase-1 (cysteinylglycinase) activity, caused significant reductions in the uptake of mercury in tubules perfused with mercuric conjugates of cysteinylglycine. These findings indicate that a significant amount of the luminal uptake of mercury, when mercuric conjugates of GSH are present in the lumen, is dependent on the activity of both γ-glutamyltransferase and cysteinylglycinase. Finally, the JD for mercury in tubules perfused with mercuric conjugates of cysteine was reduced by approximately 50% when 3.0 mM L-lysine or 5.0 mM cycloleucine was added to the perfusate. It is concluded that these findings indicate that at least some of the luminal uptake of mercuric conjugates of cysteine occurs at the site of one or more amino acid transporters via a mechanism involving molecular homology.
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McKay, S. J., J. N. Reynolds, and W. J. Racz. "Effects of mercury compounds on the spontaneous and potassium-evoked release of [3H]dopamine from mouse striatal slices." Canadian Journal of Physiology and Pharmacology 64, no. 12 (December 1, 1986): 1507–14. http://dx.doi.org/10.1139/y86-254.
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The effects of mercury compounds on the spontaneous and potassium-evoked release of [3H]dopamine from mouse striatal slices have been examined. All mercury compounds examined produced concentration-dependent increases in the spontaneous release of [3H]dopamine, with an order of potency of methylmercury > mercuric (Hg2+) mercury >p-choloromercuribenzene sulfonic acid. Methylmercury had no effect on the 25 mM potassium evoked release of [3H]dopamine in the presence of 1.3 mM calcium. However, in calcium-free conditions, methylmercury significantly increased the potassium-evoked release of [3H]dopamine. Mercuric mercury significantly reduced the 25 mM potassium evoked release of [3H]dopamine in the presence of 1.3 mM calcium, and this response was not reversible with brief washing of the tissue. In calcium-free conditions, mercuric mercury significantly elevated the evoked release of [3H]dopamine, similar to the result obtained with methylmercury. It is suggested that mercury compounds alter dopaminergic synaptic function, possibly by disrupting calcium homeostasis or calcium-dependent processes, and that methylmercury and mercuric mercury can have differential effects to alter dopaminergic neurotransmission.
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Kanhiya Mahour. "Mercury retention after Panax ginseng treatment against mercuric chloride intoxication in hepato-haemato indices in albino rats." World Journal of Biology Pharmacy and Health Sciences 13, no. 2 (February 28, 2023): 345–49. http://dx.doi.org/10.30574/wjbphs.2023.13.2.0113.
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Mercuric chloride was introduced per Os in albino rats (Rattus norvegicus) as per the LD50 (9.26 mg/kg b.w.). The assessment of mercuric chloride toxicity was done both after acute (0.926 mg/kg b.w.) and sub-acute (0.033 mg/kg b.w.) per Os treatment, while Panax ginseng was also introduced (10 mg/kg b.w.) per Os in the albino rats separately. Mercuric chloride treatment significantly increases mercury retention in liver and blood serum along with increase in liver weight, while Panax ginseng alone caused significant decrease in liver weight and mercury retention in liver and blood. Increase in mercury retention in blood serum and liver is due to the reactivity between –SH protein of blood serum and liver with oxidized form of mercury (Hg++), while decrease in Panax ginseng treatment is due to antioxidant activity of Panax ginseng the ginsenosides. Moreover, mercuric chloride followed by Panax ginseng and Panax ginseng followed by mercuric chloride treatment revealed significant modulation for raised mercury retention and liver weight towards normal level along with blood serum and liver changes. The results suggest a modulating role of Panax ginseng extract against raised mercury concentration in blood serum and liver under stress of mercuric chloride.
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Degila, Hermione W., N. B. Nadia Azon, Julien G. Adounkpe, A. V. Onésime Akowanou, and Martin P. Aïna. "Mercure: sources d’émission, toxicité, contamination du milieu aquatique et particularité du Benin." International Journal of Biological and Chemical Sciences 13, no. 7 (February 13, 2020): 3429–48. http://dx.doi.org/10.4314/ijbcs.v13i7.36.
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La prise de conscience collective du pouvoir létal du mercure suite aux intoxications massives au Japon et en Irak ont conduit à l’adoption de la convention de Minamata sur le mercure que le Bénin a signé et ratifié. Le présent article fait la synthèse des connaissances sur son émission, sa toxicité en milieu aquatique avec un accent sur la contamination aquatique au Bénin. Pour y parvenir, des publications scientifiques et les archives des ministères de l’environnement et de la santé au Bénin ont été consultées. Il ressort que, la production artisanale à petite échelle de l’or et la combustion de charbon constituent les principales sources d’émission de mercure dans le monde avec respectivement 37,1% et 24,2% des émissions anthropiques. Au Bénin, les piles contenant du mercure (49%) l’orpaillage artisanal (22%) et les dépôts informels de déchets généraux (13%) sont les principales sources potentielles d’émission anthropique. Les régions actuellement les plus émettrices de mercure sont l’Asie et l’Afrique sub-saharienne avec respectivement 50% et 16,8% des émissions anthropiques. La formation du méthylmercure en milieu aquatique sous l’influence de divers facteurs et sa bioaccumulation sont principalement responsable des effets toxiques sur l’homme.Mots clés : Environnement, pollution, mercure, méthyl mercure, milieu aquatique, toxicité.English Title: Mercury: sources of emission, toxicity, contamination of aquatic environment and particularity of Benin republic.The massive mercury poisoning that has occurred in Japan and Iraq has led to a global awareness of the lethal power of this metal with the adoption by the international community of the Minamata Convention signed and ratified by Benin Republic. This article aims to synthesize knowledge on mercury through its emission sources, its toxicity with a focus on aquatic contamination in Benin. Thus, a review of scientific publications as well as the consultation of the archives of the Ministries of Environment and Health in Benin were carried out. Analyses of the various documents show that artisanal small-scale gold production and coal combustion are the main sources of mercury emission worldwide, with respectively 37.1% and 24.2% of anthropogenic emissions. Asia and sub-Saharan Africa would be the largest contributors to anthropogenic emissions with respectively 50% and 16.8%. In Benin, the main potential sources of anthropogenic emissions are mercury containing batteries (49%), followed by artisanal gold panning (22%) and informal deposits of general waste (13%). With regard to the behavior of mercury in the aquatic environment and its toxicity, it appears that methyl mercury is mainly responsible for toxic effects.Keywords: Environment, pollution, mercury, methyl mercury, aquatic environment, toxicity Bénin.
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Staun, Chris, Neetu Bansal, and James Vaughan. "Electrocrystallization and solubility of mercury in alkaline solution." Canadian Journal of Chemistry 96, no. 4 (April 2018): 385–93. http://dx.doi.org/10.1139/cjc-2017-0592.
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The chemical thermodynamics of mercury in aqueous sodium hydroxide solution has been investigated through electrochemical polarisation and solubility experiments. A review of thermodynamic data allowed determination of the Hg/HgO electrode potential. Cyclic voltammetry revealed a complex anodic reaction beginning with aqueous dissolution of elemental mercury and subsequent electrocrystallization of mercuric oxide. Cathodic sweeps showed dual reduction reactions, attributed to the presence of aqueous mercury and mercuric oxide. The solubility and hence activity of elemental mercury in sodium hydroxide solution was determined, otherwise known as the Sechenov salt effect. Sodium hydroxide salted mercury out of solution.
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Purkan, Purkan, Yuliana Firdausi Nuzulla, Sofijan Hadi, and Endang Triwahyu Prasetyawati. "Biochemical Properties of Mercuric Reductase from Local Isolate of Bacillus sp for Bioremediation Agent." Molekul 12, no. 2 (November 30, 2017): 182. http://dx.doi.org/10.20884/1.jm.2017.12.2.398.
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Mercuric reductase is the important enzyme which catalyzes a reduction of a toxic Hg2+ to non-toxic Hg0. The enzyme which has been potentially used as mercury bioremediation agent is produced by mercury resistant bacteria. These research aims are to determinate the resistance level of a local Bacillus sp to HgCl2 in media, to determine the mercuric reductase activity from the bacteria, and to determine the biochemical properties of the mercuric reductase. The Bacillus sp was grown in the Nutrient Broth media with various of 0; 20; 40; 60; 120; and 160 µM HgCl2 to know the response of the bacteria against mercury, The cell growth of Bacillus sp was measured by optical density (OD) method of at λ 600 nm. The mercuric reductase activity was assayed in the solution of MRA (Mercury Reductase Assay), then the oxidized NADPH was observed by the spectrophotometry method at λ340 nm. The result showed that the Bacillus sp has been resistant to media containing mercury at 120 µM, but the microbial growth was decreased by 50% in media containing mercury 80 µM. The Bacillus sp could produce highly the mercuric reductase enzyme at 16 hours of growth time with enzyme activity as 0.574 Unit/µg. The mercuric reductase from the bacteria has an optimum activity at pH 6 and temperature 37 °C
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YOSHITOMI, TOMOYASU, NAOKI YAGINUMA, HIROYUKI ISO, TAKAHIRO ISHIKAWA, HITOSHI IMASEKI, and SHINO HOMMA-TAKEDA. "MERCURY DISTRIBUTION BY MICRO PIXE ANALYSIS IN STENOPSYCHE MARMORATA EXPOSED TO MERCURIC CHLORIDE." International Journal of PIXE 18, no. 01n02 (January 2008): 69–75. http://dx.doi.org/10.1142/s0129083508001363.
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Aquatic insects, such as caddisflies, are used as reference organisms for water pollution. The precise distribution of contaminated metals in the insect, however, remains unknown. In this study, we used micro PIXE analysis to examine mercury distribution in Stenopsyche marmorata, a typical caddisfly, exposed to mercuric chloride. The mercury level in the caddisflies after exposure to mercuric chloride at 1 mg/L for 5 days was 93.3 ± 25.0 μ g/g wet weight. Micro PIXE analysis also revealed a site-specific distribution of mercury in the insects. Mercury was high in the digestive tract, where it was localized in the basement membrane and the peritrophic membrane. Mercury was also detected in the tissue surrounding the digestive tract. Further examination of the tissue identified mercury in the fat body but not in the silk gland.
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Ma, Lin Zhuan, Jun Ming Guo, Ying Jie Zhang, Qiong Fang Cui, Man Hong Liu, Hong Bin Wang, and Wei Bai. "Mercury’s Leaching Contamination in Soil Environment." Advanced Materials Research 581-582 (October 2012): 117–20. http://dx.doi.org/10.4028/www.scientific.net/amr.581-582.117.
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Mercury is a material with serious toxicity, and superfluous mercury can pollute large areas. The paper studied the reaction time, pH of the leaching solution, the concentration of mercury of the leaching solution’s effect for mercury’s absorption characterstic and three synergistic effect. The paper obtained some basic data about soil’s mercury pollution.
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Farooqi, Asifa, Ghufranud Din, Rameesha Hayat, Malik Badshah, Samiullah Khan, and Aamer Ali Shah. "Characterization of Bacillus nealsonii strain KBH10 capable of reducing aqueous mercury in laboratory-scale reactor." Water Science and Technology 83, no. 9 (March 26, 2021): 2287–95. http://dx.doi.org/10.2166/wst.2021.122.
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Abstract The environmental release of mercury is continuously increasing with high degree of mobility, transformation and amplified toxicity. Improving remediation strategies is becoming increasingly important to achieve more stringent environmental safety standards. This study develops a laboratory-scale reactor for bioremediation of aqueous mercury using a biofilm-producing bacterial strain, KBH10, isolated from mercury-polluted soil. The strain was found resistant to 80 mg/L of HgCl2 and identified as Bacillus nealsonii via 16S rRNA gene sequence analysis. The strain KBH10 was characterized for optimum growth parameters and its mercury biotransformation potential was validated through mercuric reductase assay. A packed-bed column bioreactor was designed for biofilm-mediated mercury removal from artificially contaminated water and residual mercury was estimated. Strain KBH10 could grow at a range of temperature (20–50 °C) and pH (6.0–9.0) with optimum temperature established at 30 °C and pH 7.0. The optimum mercuric reductase activity (77.8 ± 1.7 U/mg) was reported at 30 °C and was stable at a temperature range of 20–50 °C. The residual mercury analysis of artificially contaminated water indicated 60.6 ± 1.5% reduction in mercury content within 5 h of exposure. This regenerative process of biofilm-mediated mercury removal in a packed-bed column bioreactor can provide new insight into its potential use in mercury bioremediation.
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Guzzi, Gianpaolo, Paolo D. Pigatto, Francesco Spadari, and Caterina A. M. La Porta. "Effect of thimerosal, methylmercury, and mercuric chloride in Jurkat T Cell Line." Interdisciplinary Toxicology 5, no. 3 (August 1, 2012): 159–61. http://dx.doi.org/10.2478/v10102-012-0026-1.
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ABSTRACT Mercury is a ubiquitous environmental toxicant that causes a wide range of adverse health effects in humans. Three forms of mercury exist: elemental, inorganic and organic. Each of them has its own profile of toxicity. The aim of the present study was to determine the effect of thimerosal, a topical antiseptic and preservative in vaccines routinely given to children, methyl mercury, and mercuric chloride on cellular viability measured by MTT in Jurkat T cells, a human T leukemia cell line. The treatment of Jurkat T cells with thimerosal caused a significant decrease in cellular viability at 1 μM (25%, p<0.05; IC50: 10 μM). Methyl mercury exhibited a significant decrease in cellular viability at 50 μM (33%, p<0.01; IC50: 65 μM). Mercuric chloride (HgCl2) did not show any significant change in cellular survival. Our findings showed that contrary to thimerosal and methyl mercury, mercuric chloride did not modify Jurkat T cell viability.
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Chalker, Justin M., Maximilian Mann, Max J. H. Worthington, and Louisa J. Esdaile. "Polymers Made by Inverse Vulcanization for Use as Mercury Sorbents." Organic Materials 03, no. 02 (April 2021): 362–73. http://dx.doi.org/10.1055/a-1502-2611.
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Inverse vulcanization is a process in which highly abundant and low-cost elemental sulfur is copolymerized with an unsaturated organic molecule such as a polyene. This process has provided a variety of useful materials with high sulfur content—typically 50% or greater in sulfur by mass. These materials have garnered increasing interest in research as sorbents for mercury, due to the high affinity of sulfur for mercury. In this review, the features of mercury sorbents made by inverse vulcanization are presented. Additionally, case studies are provided to illustrate the variety of polymer architectures accessible with this chemistry, the versatility of these materials in mercury remediation, and prospects for industrial use.1 Introduction2 Sulfur Polymers by Inverse Vulcanization3 Sulfur Polymers as Mercury Sorbents4 Increasing Surface Area to Improve Mercury Uptake5 Crosslinker Considerations6 Sorption of Different Forms of Mercury7 Life-Cycle Management8 Conclusions and Outlook
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Ullah, Hashmat, and Muhammad Farid Khan. "BLOOD." Professional Medical Journal 22, no. 03 (March 10, 2015): 365–69. http://dx.doi.org/10.29309/tpmj/2015.22.03.1358.
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All forms of mercury are global pollutants having no environmental limits.Human exposure to mercury occurs basically through food chain due to accumulation oforganic forms of mercury in fish. Objectives: The purpose of the present study was to analyzethe effect of phenyl mercuric acetate on plasma and cytosolic fraction GSH. Study Design:Experimental Study. Setting: Department of Pharmaceutical Chemistry, Faculty of Pharmacy,Gomal University, Dera Ismail Khan. Period: 29 January 2011 to 11 march 2012 .StatisticalAnalysis: One-way ANOVA followed by Dunnet’s HSD test. Results: For the estimation ofthiols Ellman’s method was used and was found statistically significant (p < 0.001) decreasein plasma and cytosolic fraction GSH which was dose and time dependent. The plasma GSHcontents drop in 0 to 120 minutes by various concentrations of phenyl mercuric acetate were64.45%, 59.33%, 50.89%, 41.56%, 33.63% and 32.99% while drop in cytosolic fraction GSHlevel from 0 to 120 minutes by different concentrations of phenyl mercuric acetate (PMA) was53.86%, 48.60%, 45.41%, 36.11%, 29.38% and 27.06%.Conclusions: It is clear that duringorganic mercury toxicity the blood components are also affected which is proved from ourresults. With the increase of time ,the mercury toxicity would be more harmful so detoxificationof organic mercury should be done on emergency bases at the earliest with the help of suitablechelating agents along with antioxidant therapy.
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Scora, Jennifer, Diana Valencia, Alessandro Morbidelli, and Seth Jacobson. "Forming Mercury from Excited Initial Conditions." Astrophysical Journal 967, no. 1 (May 1, 2024): 1. http://dx.doi.org/10.3847/1538-4357/ad39e6.
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Abstract Mercury is notoriously difficult to form in Solar System simulations, due to its small mass and iron-rich composition. Smooth particle hydrodynamics simulations of collisions have found that a Mercury-like body could be formed by one or multiple giant impacts, but due to the chaotic nature of collisions, it is difficult to create a scenario where such impacts will take place. Recent work has found more success forming Mercury analogues by adding additional embryos near Mercury’s orbit. In this work, we aim to form Mercury by simulating the formation of the Solar System in the presence of the giant planets Jupiter and Saturn. We test out the effect of an inner disk of embryos added on to the commonly used narrow annulus of initial material. We form Mercury analogues with core-mass fractions (CMFs) > 0.4 in ∼10% of our simulations, and twice that number of Mercury analogues form during the formation process but are unstable and do not last to the end of the simulations. Mercury analogues form at similar rates for both disks with and without an inner component, and most of our Mercury analogues have lower CMFs than that of Mercury, ∼0.7, due to significant accretion of debris material. We suggest that a more in-depth understanding of the fraction of debris mass that is lost to collisional grinding is necessary to understand Mercury’s formation, or some additional mechanism is required to stop this debris from accreting.
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McGoun, Elton G. "Crazy 'Bout a Mercury." Review of International American Studies 14, no. 2 (December 19, 2021): 57–74. http://dx.doi.org/10.31261/rias.11654.
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When we purchase an automobile, we are also acquiring an amorphous but very real image, that is, the statement which the automobile makes about its owner to the public. Such images are forged in popular culture, and Mercury is an automobile brand that had an auspicious post-WWII popular culture debut. In 1948, K.C. Douglas recorded “Mercury Boogie” on a 10-inch 78-RPM, with its memorable line in the chorus “I’m crazy ‘bout a Mercury.” Five years later in 1953, George and Sam Barris transformed a 1951 Mercury Club Coupe into the Hirohata Merc, creating a classic of customization that has been described as “the most famous custom of all time” (Taylor 2006: 56). Ford occasionally attempted to take advantage of these strong roots in popular culture formed in the make’s earliest days, but the company’s efforts were not notably successful. In spite of Mercury’s promising beginnings in media, it has had only a slight presence in music and film. Mercury’s image never influenced the automobile market beyond the first few years, and it was unable to prevent the brand’s 2011 demise.
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Hight, Susan C. "Rapid Determination of Methyl Mercury in Fish and Shellfish: Collaborative Study." Journal of AOAC INTERNATIONAL 70, no. 4 (July 1, 1987): 667–72. http://dx.doi.org/10.1093/jaoac/70.4.667.
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Abstract A modification of the official AOAC method for determining methyl mercury in fish and shellfish was studied in 8 laboratories. Methyl mercury is isolated from homogenized, acetone-washed tissue by adding HC1 and extracting into toluene the methyl mercuric chloride produced. The extract is analyzed for methyl mercuric chloride by electron capture gas chromatography. Collaborators determined methyl mercury in blind duplicate homogenates at 2 levels in tuna and at 1 level in swordfish and oysters. Collaborators also analyzed single homogenates of swordfish and oysters containing methyl mercury at a second level. Both fortified and unfortified tissues were analyzed. Methyl-bound mercury in the commodities ranged from 0.50 to 2.30 μg Hg/g. Reproducibility coefficients of variation ranged from 4 to 15%. Accuracy, measured by comparison to reference values, ranged from 92 to 101%. Recovery from fortified homogenates ranged from 86 to 98%. Reference values and unfortified levels were determined in the author's laboratory by replicate analysis of fortified
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Wigfield, Donald C., and Sherry L. Perkins. "Oxidation of elemental mercury by hydroperoxides in aqueous solution." Canadian Journal of Chemistry 63, no. 2 (February 1, 1985): 275–77. http://dx.doi.org/10.1139/v85-045.
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The recent development of techniques in this and other laboratories has allowed the exploration of elemental mercury oxidations by compounds bearing the —O—O—H moiety. The peracid group appears to be a far more effective oxidant of mercury than the peroxide group, and both peracetic acid and m-chloroperbenzoic acid oxidize mercury at the trace level to both mercurous and mercuric forms.
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Popel, S. I., A. P. Golub', and L. M. Zelenyi. "Dusty plasmas above the sunlit surface of Mercury." Physics of Plasmas 30, no. 4 (April 2023): 043701. http://dx.doi.org/10.1063/5.0142936.
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Above the sunlit surface of Mercury, the properties and formation of dusty plasmas are investigated. It is demonstrated that the dusty plasmas are formed for subsolar angles exceeding approximately 76° due to photoelectric and electrostatic processes. As a result, the dusty plasmas are present in the polar regions of Mercury, characterized by latitudes of about 70° and above. The formation of dusty plasmas is also possible for lower latitudes, but only where the surface profile allows it. Plasmas above the sunlit surface of Mercury consist, in particular, of photoelectrons, electrons, and ions of the solar wind, and also charged dust particles. The distribution functions of photoelectrons near the surface of Mercury, as well as the altitude dependences of the number densities of dust particles, their charges and sizes, as well as electric fields, are obtained. The calculations are carried out which correspond to the position of Mercury at aphelion and perihelion of its orbit for the situations of dusty plasma location in the vicinity of magnetic poles of Mercury and in other regions. It is shown that there are qualitative differences between the dusty plasma systems of Mercury and the Moon related to the fact that Mercury has a magnetosphere and Mercury's orbit is one of the most eccentric of all planetary orbits in the Solar System. The effects of magnetic fields can slightly influence the dust particle transport and, correspondingly, the expansion of the region of the existence of dusty plasmas above the surface of Mercury due to the effect of dust particle transport is not so significant as at the Moon. Furthermore, due to the presence of Mercury's magnetosphere, the solar wind is important for the formation of dusty plasmas at Mercury only in the vicinity of the regions of the magnetic poles. In other regions of Mercury, in contrast to the situation at the Moon, the solar wind does not influence significantly the dusty plasma properties. The dusty plasma parameters are different in the cases of aphelion and perihelion of the orbit of Mercury.
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Toet, A. E., A. van Dijk, T. J. F. Savelkoul, and J. Meulenbelt. "Mercury Kinetics in a Case of Severe Mercuric Chloride Poisoning Treated with Dimercapto-1-propane Sulphonate (DMPS)." Human & Experimental Toxicology 13, no. 1 (January 1994): 11–16. http://dx.doi.org/10.1177/096032719401300103.
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1 A case of severe mercuric chloride poisoning with clinical signs of mucosal damage of the gastrointestinal tract and anuric renal failure, is presented. The initial whole blood mercury concentration was 14,300 ?g 1-1. This concentration is supposed to be associated with fatal outcome due to multiple organ failure. 2 Because of anuric renal failure, haemodialysis was necessary. Kidney function returned to normal within 10 days. Haemodialysis proved to be ineffective with regard to total mercury elimination. 3 Treatment with DMPS was started because of very severe poisoning, anuric renal failure and optimistic reports on the 'new' chelating agent 2,3-dimercapto-1-propanesulphonic acid (DMPS) in mercury poisoning. DMPS was administered by parenteral route initially and was continued thereafter by oral route, until whole blood and urine mercury concentrations had decreased below a level considered as toxic. Except for a temporary pruritic erythema of the skin, no side effects of DMPS treatment were observed. 4 The clinical course was mild, despite continuing high whole blood mercury concentrations, Recovery was uneventful and complete. DMPS treatment, administered by intravenous and oral route, was shown to be an effective alternative for BAL in life-threatening mercuric chloride intoxication. 5 The pharmacokinetic data presented in this case report suggest that non-renal mercury clearance may considerably exceed renal mercury clearance.
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Ernst, Carolyn M., Nancy L. Chabot, Rachel L. Klima, Sanae Kubota, Gabe Rogers, Paul K. Byrne, Steven A. Hauck, et al. "Science Goals and Mission Concept for a Landed Investigation of Mercury." Planetary Science Journal 3, no. 3 (March 1, 2022): 68. http://dx.doi.org/10.3847/psj/ac1c0f.
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Abstract Mercury holds valuable clues to the distribution of elements at the birth of the solar system and how planets form and evolve in close proximity to their host stars. This Mercury Lander mission concept returns in situ measurements that address fundamental science questions raised by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission’s pioneering exploration of Mercury. Such measurements are needed to understand Mercury's unique mineralogy and geochemistry, characterize the proportionally massive core's structure, measure the planet's active and ancient magnetic fields at the surface, investigate the processes that alter the surface and produce the exosphere, and provide ground truth for remote data sets. The mission concept achieves one full Mercury year (∼88 Earth days) of surface operations with an 11-instrument, high-heritage payload delivered to a landing site within Mercury's widely distributed low-reflectance material, and it addresses science goals encompassing geochemistry, geophysics, the Mercury space environment, and geology. The spacecraft launches in 2035, and the four-stage flight system uses a solar electric propulsion cruise stage to reach Mercury in 2045. Landing is at dusk to meet thermal requirements, permitting ∼30 hr of sunlight for initial observations. The radioisotope-powered lander continues operations through the Mercury night. Direct-to-Earth communication is possible for the initial 3 weeks of landed operations, drops out for 6 weeks, and resumes for the final month. Thermal conditions exceed lander operating temperatures shortly after sunrise, ending operations. Approximately 11 GB of data are returned to Earth. The cost estimate demonstrates that a Mercury Lander mission is feasible and compelling as a New Frontiers–class mission.
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Brown, N. L., Y. C. Shih, C. Leang, K. J. Glendinning, J. L. Hobman, and J. R. Wilson. "Mercury transport and resistance." Biochemical Society Transactions 30, no. 4 (August 1, 2002): 715–18. http://dx.doi.org/10.1042/bst0300715.
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Resistance to mercuric ions in bacteria is conferred by mercuric reductase, which reduces Hg(II) to Hg(0) in the cytoplasmic compartment. Specific mercuric ion transport systems exist to take up Hg(II) salts and deliver them to the active site of the reductase. This short review discusses the role of transport proteins in resistance and the mechanism of transfer of Hg(II) between the mercury-resistance proteins.
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Dixit, Vidula, Elisabetta Bini, Melissa Drozda, and Paul Blum. "Mercury Inactivates Transcription and the Generalized Transcription Factor TFB in the Archaeon Sulfolobus solfataricus." Antimicrobial Agents and Chemotherapy 48, no. 6 (June 2004): 1993–99. http://dx.doi.org/10.1128/aac.48.6.1993-1999.2004.
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ABSTRACT Mercury has a long history as an antimicrobial agent effective against eukaryotic and prokaryotic organisms. Despite its prolonged use, the basis for mercury toxicity in prokaryotes is not well understood. Archaea, like bacteria, are prokaryotes but they use a simplified version of the eukaryotic transcription apparatus. This study examined the mechanism of mercury toxicity to the archaeal prokaryote Sulfolobus solfataricus. In vivo challenge with mercuric chloride instantaneously blocked cell division, eliciting a cytostatic response at submicromolar concentrations and a cytocidal response at micromolar concentrations. The cytostatic response was accompanied by a 70% reduction in bulk RNA synthesis and elevated rates of degradation of several transcripts, including tfb-1, tfb-2, and lacS. Whole-cell extracts prepared from mercuric chloride-treated cells or from cell extracts treated in vitro failed to support in vitro transcription of 16S rRNAp and lacSp promoters. Extract-mixing experiments with treated and untreated extracts excluded the occurrence of negative-acting factors in the mercury-treated cell extracts. Addition of transcription factor B (TFB), a general transcription factor homolog of eukaryotic TFIIB, to mercury-treated cell extracts restored >50% of in vitro transcription activity. Consistent with this finding, mercuric ion treatment of TFB in vitro inactivated its ability to restore the in vitro transcription activity of TFB-immunodepleted cell extracts. These findings indicate that the toxicity of mercuric ion in S. solfataricus is in part the consequence of transcription inhibition due to TFB-1 inactivation.
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Belfarhi, Leila, Ibtissem Chouba, Naziha Amri, Nadia Boukris, and Abdelkrim Tahraoui. "Histological and Hormonal Study of the Protective Effect of the Calotropis Procera Against the Toxicity of Mercury Chloride." Natural Systems and Resources, no. 2 (October 2020): 5–14. http://dx.doi.org/10.15688/nsr.jvolsu.2020.2.1.
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We undertook this study with the aim of investigating the detoxification of an extreme toxic metal mercury chloride by the Calotropis procera plant taken from the Algerian Sahara. We studied the protective effects of the plant Calotropis procera against renal toxicity and Mercury chloride-induced hepatic. Ten male and female albino rats Wistar were divided into four equal groups. Group (I) served as a healthy control group, group (II) were intra-peritoneal administered with 10 ml of Calotropis procera, group (III) were intra-peritoneal administrated with both 10 ml of the plant Calotropis procera and 0.2 mg of mercuric chloride (HgCl2) and group (IV) were intraperitoneal administrated with both 0.2 mg of mercuric chlorid (HgCl2) and 10 ml of the plant Calotropis. All groups were treated for 20 days. Mercury chloride causes a slight increase in glomerular cellularitis in the kidneys of male and female rats. Treatment with Calotropis procera had significantly improving protective effects of kidney of female rats from toxicity of mercuric chloride. Calotropis procera causes a thyroid-like appearance in the glomeruli of the male kidneys to hide the lesions of mercury chloride. Our results have shown that the plant Calotropis procera completely protects the liver of female rats against the toxicity of mercury chloride. In the liver of male rats, mercury chloride causes macro-vacuolar steatosis. Treatment with Calotrpois procera hid the hepatic steatosis of male rats and centralized them in the center under the aspect of peri-centro-lobular medio-vacuolar steatosis. Mercuric chloride caused a decrease in the secretion of the hormone ACTH in the group of male and female rats. Treatment with Calotropis procera caused increased ACTH levels in female rats and did not cause ACTH changes in male rats. Our results demonstrate from hormone analyzes of the hormone ACTH that female rats are resistant more than male rats via the toxicity of mercury chloride.
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Omanwar, S., B. Saidullah, K. Ravi, and M. Fahim. "Vasorelaxant effects of mercury on rat thoracic aorta." Human & Experimental Toxicology 33, no. 9 (December 17, 2013): 904–10. http://dx.doi.org/10.1177/0960327113512341.
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Mercury, a heavy metal, is widespread and persistent in the environment and has been elucidated as a possible risk factor in cardiovascular diseases. Mercury has been reported to selectively impair the nitric oxide (NO) pathway in the vascular endothelium as a consequence of oxidative stress. Conversely, mercury per se causes endothelium-dependent vasorelaxation at lower concentration via the NO pathway. Little is known about the effects of mercury per se on other endothelial mediators. To elucidate possible mechanisms involved in this action, isometric tension was measured in aortic rings precontracted with phenylephrine (10 µM) from Wistar rats. Responses to increasing concentrations of inorganic mercuric chloride (10−12–10−5 M) were obtained in the presence and absence of endothelium. Inorganic mercury produced a biphasic response in endothelium-intact aortic rings and produced only vasoconstriction in endothelium-denuded aortic rings. To study the possible underlying mechanisms for the biphasic response of mercury, increasing concentrations of mercuric chloride (10−12–10−5 M) were used before and after NG-nitro-l-arginine methyl ester (L-NAME (10−4 M)), glybenclamide (10−5 M), superoxide dismutase (10 U/ml) + catalase (100 U/ml), and nifedipine (10−4 M) treatment. Results suggest that mercury produces endothelium-dependent relaxation at low concentration mediated by endothelial-generated NO and endothelium-derived hyperpolarizing factor and endothelium-independent contraction resulting from the blockade of l-type Ca2+ channels by generation of free radicals.
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Zalups, R. K., and D. W. Barfuss. "Participation of mercuric conjugates of cysteine, homocysteine, and N-acetylcysteine in mechanisms involved in the renal tubular uptake of inorganic mercury." Journal of the American Society of Nephrology 9, no. 4 (April 1998): 551–61. http://dx.doi.org/10.1681/asn.v94551.
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Mechanisms involved in the renal uptake of inorganic mercury were studied in rats administered a nontoxic 0.5 mumol/kg intravenous dose of inorganic mercury with or without 2.0 mumol/kg cysteine, homocysteine, or N-acetylcysteine. The renal disposition of mercury was studied 1 h after treatment in normal rats and rats that had undergone bilateral ureteral ligation. In addition, the disposition of mercury (including the urinary and fecal excretion of mercury) was evaluated 24 h after treatment. In normal rats, coadministering inorganic mercury plus cysteine or homocysteine caused a significant increase in the renal uptake of mercury 1 h after treatment. The enhanced renal uptake of mercury was due to increased uptake of mercury in the renal outer stripe of the outer medulla and/or renal cortex. Ureteral ligation caused reductions in the renal uptake of mercury in all groups except for the one treated with inorganic mercury plus N-acetylcysteine. Thus, it appears that virtually all of the mercury taken up by the kidneys of the normal rats treated with inorganic mercury plus N-acetylcysteine occurred at the basolateral membrane. Urinary excretory data also support this notion, in that the rate of excretion of inorganic mercury was greatest in the rats treated with inorganic mercury plus N-acetylcysteine. Our data also indicate that uptake of inorganic mercury in the kidneys of rats treated with inorganic mercury plus cysteine occurred equally at both luminal and basolateral membranes. In addition, the renal uptake of mercury in rats treated with inorganic mercury plus homocysteine occurred predominantly at the basolateral membrane with some component of luminal uptake. The findings of the present study confirm that there are at least two distinct mechanisms involved in the renal uptake of inorganic mercury, with one mechanism located on the luminal membrane and the other located on the basolateral membrane. Our findings also show that cysteine and homologs of cysteine, when coadministered with inorganic mercury, greatly influence the magnitude and/or site of uptake of mercuric ions in the kidney.
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Spyropoulou, Alexandra, Chrysi Laspidou, Kostantinos Kormas, and Yannis G. Lazarou. "The Impact of Possible Mercury Source-Point Contamination in the Coastal Area of Skiathos Island." Environmental Sciences Proceedings 2, no. 1 (September 5, 2020): 50. http://dx.doi.org/10.3390/environsciproc2020002050.
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In Skiathos Island the water is not potable due to mercury contamination and salinization. The mercury’s origin is natural due to the existence of cinnabar in the Skiathos aquifer as a mineral in the Earth’s crust. The possibility of mercury contaminants ending up in the coastal area was investigated through a field experiment. Mussels (Mytilus galloprovincialis) were employed as mercury monitoring biomarkers at the outflow of the wastewater treatment of the island. Using the RNA:DNA ratio, it was revealed that the organisms were stressed after three months of exposure to Skiathos’ coastal waters. The mercury concentration was directly measured at the bulk mussels’ tissue showing differences between the station located at the outflow of the WWT and the reference station. Although the results may imply mercury contamination in the coastal area of the island, the precise origin of the mercury in mussels is difficult to define.
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Deacon, GB, and GN Stretton. "Organomercury Compounds. XXVII. The Synthesis and Properties of Some Carboxylato- and Carboxy-pyridinylmercurials." Australian Journal of Chemistry 38, no. 3 (1985): 419. http://dx.doi.org/10.1071/ch9850419.
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Decarboxylation of mercuric pyridine-2,3-dicarboxylate in hot dimethyl sulfoxide or hexamethylphosphoramide gives a mixture of 2-carboxylatopyridin-3-ylmercury(II) (major product) and 3- carboxylatopyridin-2-ylmercury(II) (minor product). The mixture reacts ( i ) with acidified halide ions ( Cl - or I-) to yield a mixture of the corresponding carboxypyridinyl ( halogeno )mercury(II) derivatives, (ii) with tribromide ions to give the bromo ( carboxypyridinyl )mercury(ii) complexes, 3-bromopyridine-2-carboxylic acid, and 2-bromopyridine-3- carboxylic acid, and (iii) with iodide ions in hot aqueous acetic acid to yield bis (2-carboxypyridin-3-yl)mercury(II) hydrogen triiodomercurate (II). Solutions of the last compound in dimethyl sulfoxide deposit bis (2-carboxypyridin-3-yl)mercury(II). Reaction of pyridine-2,3-dicarboxylate ions with mercuric acetate in boiling aqueous acetic acid at pH 5.0-5.8 gives mercurated acetic acid as the sole organometallic product, and the reported1 decarboxylation yielding 3-carboxylatopyridin-2-ylmercury(II) is not observed.
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Awitor, Komla Oscar, Laurent Bernard, Olivier Bonnin, Bernard Coupat, Jean Paul Fournier, and Philippe Verdier. "Article." Canadian Journal of Chemistry 77, no. 2 (February 1, 1999): 243–48. http://dx.doi.org/10.1139/v98-237.
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Mercurous chloride (Hg2Cl2), or calomel, was prepared by direct synthesis from commercial mercury and mercuric chloride. The mercuric chloride mass fraction in the synthesized material is particularly small. The mercurous chloride vapor pressure was measured between 353 and 453 K by the Knudsen cell method. In order to obtain the mercurous chloride vapor pressure, we took into account the dissociation in the vapor phase into mercury and mercuric chloride. Our results are compared with those in the literature.Key words: mercurous chloride, calomel, vapor pressure, mass spectrometry, Knudsen cell.
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Sieler, Roman. "Mercurial Medicines." Asian Medicine 17, no. 1 (March 14, 2022): 148–85. http://dx.doi.org/10.1163/15734218-12341510.
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Abstract Using ethnographic data, this article suggests that the therapeutic use of various mercury compounds in siddha medicine has so far not decreased despite international regulation of the substance and discussions surrounding the safety of mercury. Siddha practitioners portray mercury as central to their therapeutics. The article demonstrates this for different contexts, including the preparation of mercuric medicines; the production of mercury amulets; and recent research studies on mercury-based siddha drugs, targeting, for instance, dementia-related syndromes. Contextualizing siddha mercurial procedures and preparations through interlinking therapeutic, historical, and global frames underscores the fact that mercury use in siddha medicine today derives from alchemical traditions, but also transcends them. It is embedded in political contexts of science and healthcare in India, as it answers to concerns about safety and toxicity and at the same time takes center stage in negotiating siddha medical specialty and alterity vis-à-vis other medical practices, most notably ayurveda.
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Handy, R. D. "Comparison of intermittent and continuous exposure to mercuric chloride in rainbow trout (Oncothynchus mykiss), goldfish (Carassius auratus), and the fathead minnow (Pimephales ptomelas)." Canadian Journal of Fisheries and Aquatic Sciences 52, no. 1 (January 1, 1995): 13–22. http://dx.doi.org/10.1139/f95-002.
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Rainbow trout (Oncorhynchus mykiss), goldfish (Carassius auratus), and the fathead minnow (Pimephales promelas) were exposed continuously or intermittently (24-h exposure: 24-h recovery) to a nominal peak concentration of 3 μg∙L−1 mercuric chloride for 120 h. There were no differences in the target organs or the distribution of the toxicant within internal organs between the two exposure regimes. Mercury concentrations in the tissues of intermittently exposed fish were less than those of continuously exposed fish. The lower mercury concentrations in the intermittently exposed groups arose from reduced or negligible accumulation during recovery periods rather than mercury excretion. The accumulation of mercury during intermittent exposure is roughly proportional to the exposure duration, and could therefore be predicted from a continuous exposure of equivalent total exposure duration. This proportionality exists when (1) peak concentrations of mercury are the same in both regimes, and (2) the recovery periods are short compared with the biological half-life for mercury.
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Heath, Julie A., and Peter C. Frederick. "Relationships Among Mercury Concentrations, Hormones, and Nesting Effort of White Ibises (Eudocimus Albus) in the Florida Everglades." Auk 122, no. 1 (January 1, 2005): 255–67. http://dx.doi.org/10.1093/auk/122.1.255.
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Abstract Mercury, a common wetland pollutant, can affect wildlife populations through acute toxicity or through physiological effects that modify behavior and negatively influence reproductive success. We compared body-feather mercury concentrations of free-living male and female adult White Ibises (Eudocimus albus) during three breeding seasons in the Florida Everglades and examined the relationships among mercury, hormone concentrations, and body-condition scores. Female White Ibises consistently had lower mercury concentrations than males. Prebreeding females' estradiol concentrations were negatively correlated with mercury concentrations. However, we found no relationship between mercury and female testosterone, progesterone, and corticosterone concentrations. Incubating male White Ibises showed a significant positive relationship between testosterone and mercury concentrations, but no other significant hormonal correlations with mercury concentrations. We used a seven-year standardized data set of Great Egret (Ardea alba) chick-feather mercury concentrations as a measure of temporal changes in mercury bioavailability in the Everglades and related that measure to annual numbers of White Ibis nests. White Ibis nesting was negatively correlated with the mercury exposure index. Low numbers of nesting White Ibises may have been the result of fewer birds nesting or high abandonment rates. Our results suggest that mercury exposure may cause fewer birds to nest or more birds to abandon nests because of subacute effects on hormone systems. However, the results are correlative; they call for further investigation in free-living populations and in the laboratory. Relaciones entre las Concentraciones de Mercurio, Hormonas y el Esfuerzo de Nidificación de Eudocimus albus en los Everglades, Florida
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Nigro, Marco. "Mercury and selenium localization in macrophages of the striped dolphin, Stenella coeruleoalba." Journal of the Marine Biological Association of the United Kingdom 74, no. 4 (November 1994): 975–78. http://dx.doi.org/10.1017/s0025315400090226.
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The cellular features of mercury and selenium accumulation has been studied by transmission electron microscopy and x-ray microprobe analysis in the liver of striped dolphins. Mercury and selenium occurred as dense intracellular granules, located mainly within the liver macrophages (Kupffer cells). Granules were composed of 150 A spherical particles showing the same electron diffraction pattern and x-ray spectrum as mercuric selenide. The role of macrophages in mercuric selenide granule production and storage is discussed.
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Murray, Kim M., and Jennifer C. Hedgepeth. "Intravenous Self-Administration of Elemental Mercury: Efficacy of Dimercaprol Therapy." Drug Intelligence & Clinical Pharmacy 22, no. 12 (December 1988): 972–75. http://dx.doi.org/10.1177/106002808802201208.
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Deliberate parenteral self-injection of mercury is extremely rare, and is associated with a high degree of mortality and morbidity. Because mercury depresses cellular enzymatic mechanisms by combining with sulfhydryl groups, soluble mercuric salts are toxic to all cells. Embolization of mercury in the lungs has been reported with varying degrees of changes in pulmonary function. Mercury causes urticaria progressing to weeping dermatitis, leukopenia, anemia, diarrhea, salivation, liver damage, and renal damage progressing to acute renal failure with anuria. Dimercaprol is an effective antidote in acute heavy metal intoxication because its two sulfhydryl groups successfully compete with tissue enzyme sulfhydryl groups for the offending metal. Experience with dimercaprol therapy months after the original exposure to mercury is not available. We describe the hospital course of a patient after intravenous elemental injection and the results of dimercaprol therapy months after the original exposure.
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Ogunseitan, O. A. "Protein Method for Investigating Mercuric Reductase Gene Expression in Aquatic Environments." Applied and Environmental Microbiology 64, no. 2 (1998): 695–702. http://dx.doi.org/10.1128/aem.64.2.695-702.1998.
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A colorimetric assay for NADPH-dependent, mercuric ion-specific oxidoreductase activity was developed to facilitate the investigation of mercuric reductase gene expression in polluted aquatic ecosystems. Protein molecules extracted directly from unseeded freshwater and samples seeded with Pseudomonas aeruginosa PU21(Rip64) were quantitatively assayed for mercuric reductase activity in microtiter plates by stoichiometric coupling of mercuric ion reduction to a colorimetric redox chain through NADPH oxidation. Residual NADPH was determined by titration with phenazine methosulfate-catalyzed reduction of methyl thiazolyl tetrazolium to produce visible formazan. Spectrophotometric determination of formazan concentration showed a positive correlation with the amount of NADPH remaining in the reaction mixture (r 2 = 0.99). Mercuric reductase activity in the protein extracts was inversely related to the amount of NADPH remaining and to the amount of formazan produced. A qualitative nitrocellulose membrane-based version of the method was also developed, where regions of mercuric reductase activity remained colorless against a stained-membrane background. The assay detected induced mercuric reductase activity from 102 CFU, and up to threefold signal intensity was detected in seeded freshwater samples amended with mercury compared to that in mercury-free samples. The efficiency of extraction of bacterial proteins from the freshwater samples was (97 ± 2)% over the range of population densities investigated (102 to 108 CFU/ml). The method was validated by detection of enzyme activity in protein extracts of water samples from a polluted site harboring naturally occurring mercury-resistant bacteria. The new method is proposed as a supplement to the repertoire of molecular techniques available for assessing specific gene expression in heterogeneous microbial communities impacted by mercury pollution.
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Kotdawala, R. R., Nikolaos Kazantzis, and Robert W. Thompson. "Molecular simulation studies on the adsorption of mercuric chloride." Environmental Chemistry 4, no. 1 (2007): 55. http://dx.doi.org/10.1071/en06034.
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Environmental context. The Clean Air Act amendments of 1990 identified mercury and associated compounds as hazardous air pollutants of particular concern to human health and the environment. Coal-fired power plants and municipal solid waste incinerators are significant sources of mercury-containing emissions. Adsorption represents a common technique used to alleviate mercury contamination. The present study uses molecular simulations to study the correlation between key surface characteristics of the adsorbent and its mercury capturing ability with a view to the selection and design of novel adsorbents. Abstract. In the present study, Monte Carlo simulations were used to model the physical adsorption of oxidised mercury (mercuric chloride) by zeolite NaX and activated carbon in the temperature range of 400–500 K. In particular, we considered zeolite NaX with spherical cavities and sodium cations, as well as activated carbon with slit carbon pores and hydroxyl, carboxyl and carbonyl sites, and layers of calcium hydroxide. The adsorption capacity and affinity of zeolite NaX were compared with those displayed by activated carbon with different acid sites and calcium hydroxide by assessing the impact on mercuric chloride adsorption within a practical range of magnitudes of the electrostatic interactions considered, namely charge-induced dipole and charge-quadrupole interactions, as well as dispersion interactions.
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Schelert, James, Vidula Dixit, Viet Hoang, Jessica Simbahan, Melissa Drozda, and Paul Blum. "Occurrence and Characterization of Mercury Resistance in the Hyperthermophilic Archaeon Sulfolobus solfataricus by Use of Gene Disruption." Journal of Bacteriology 186, no. 2 (January 15, 2004): 427–37. http://dx.doi.org/10.1128/jb.186.2.427-437.2004.
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ABSTRACT Mercury resistance mediated by mercuric reductase (MerA) is widespread among bacteria and operates under the control of MerR. MerR represents a unique class of transcription factors that exert both positive and negative regulation on gene expression. Archaea and bacteria are prokaryotes, yet little is known about the biological role of mercury in archaea or whether a resistance mechanism occurs in these organisms. The archaeon Sulfolobus solfataricus was sensitive to mercuric chloride, and low-level adaptive resistance could be induced by metal preconditioning. Protein phylogenetic analysis of open reading frames SSO2689 and SSO2688 clarified their identity as orthologs of MerA and MerR. Northern analysis established that merA transcription responded to mercury challenge, since mRNA levels were transiently induced and, when normalized to 7S RNA, approximated values for other highly expressed transcripts. Primer extension analysis of merA mRNA predicted a noncanonical TATA box with nonstandard transcription start site spacing. The functional roles of merA and merR were clarified further by gene disruption. The merA mutant exhibited mercury sensitivity relative to wild type and was defective in elemental mercury volatilization, while the merR mutant was mercury resistant. Northern analysis of the merR mutant revealed merA transcription was constitutive and that transcript abundance was at maximum levels. These findings constitute the first report of an archaeal heavy metal resistance system; however, unlike bacteria the level of resistance is much lower. The archaeal system employs a divergent MerR protein that acts only as a negative transcriptional regulator of merA expression.
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Jindal, Mitali, Gobind Rai Garg, Pramod Kumari Mediratta, and Mohammad Fahim. "Protective role of melatonin in myocardial oxidative damage induced by mercury in murine model." Human & Experimental Toxicology 30, no. 10 (December 7, 2010): 1489–500. http://dx.doi.org/10.1177/0960327110391685.
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This study was designed to investigate the electrophysiological, hemodynamic and biochemical parameters of mercuric chloride and methylmercury exposure on cardiovascular functions and its modulation by melatonin in vivo. Wistar albino rats were divided into six group containing 10 animals each. Mercuric chloride (3.75 µM/L) in drinking water and methylmercury (0.5 mg/kg/day) through gavage, given for 1 month, induced a statistically significant increase ( p < 0.001) in left ventricular end diastolic pressure, blood and cardiac tissue mercury content and myocardial lipid peroxides compared to control. Significant attenuation ( p < 0.05) of baroreflex sensitivity and depletion of myocardial endogenous antioxidants ( p < 0.001) viz. Reduced glutathione (GSH) and superoxide dismutase (SOD) were also found in the mercury-exposed groups as compared to control group. Mercury exposure followed by subacute treatment with melatonin (4 µg/mL/day) in drinking water for 1 month significantly lowered ( p < 0.01) left ventricular end diastolic pressure and lipid peroxide levels and increased baroreceptor sensitivity ( p < 0.001) and also levels of GSH and SOD ( p < 0.001) as compared to mercury-exposed rats. The results of our study provide clear evidence that elevated oxidative stress and altered baroreflex mechanisms caused by mercury intoxication may be the contributing factors responsible for impairment of cardiovascular functions and melatonin may exhibit cardioprotective property against subacute heavy metal intoxication and enhance the antioxidant defense against mercury-induced oxidative myocardial injury in rats.
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Guzmán-Uria, Fabiola, Isabel Morales-Belpaire, Dario Achá, and Marc Pouilly. "Particulate Mercury and Particulate Organic Matter in the Itenez Basin (Bolivia)." Applied Sciences 10, no. 23 (November 26, 2020): 8407. http://dx.doi.org/10.3390/app10238407.
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In rivers and other freshwater bodies, the presence of mercury can be due to direct contamination by anthropic activities such as gold mining. However, it can also be attributed to atmospheric deposition and erosion, runoff, or lixiviation from surrounding soils. In the case of the Amazon rainforest, high mercury contents have been reported for litter and topsoil, which could affect the mercury concentrations in water bodies. Samples of suspended particulate matter were obtained from a transect of the Itenez River, associated lakes, and some of its tributaries. The aim was to obtain information on particulate mercury’s origin in the study area and determine the relationship between particulate mercury and particulate organic carbon. The concentration of mercury, organic matter, and the C:N ratio of the suspended matter was determined. The concentration of particulate mercury by water volume depended on changes in suspended matter loads, which in turn were mostly affected by the nature of the watershed or sediment resuspension. The observed values for the percentage of organic matter and the C:N ratio suggest that most of the mercury content in rivers and lakes originated from soils. A positive correlation was found between mercury concentration by weight of particulate matter and organic carbon content in particles. This correlation might be due to the direct binding of mercury to organic matter through functional groups like thiols or to an indirect effect of oxyhydroxides that can adsorb mercury and are associated with organic matter.
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Kanan, Sofian M., Imad A. Abu-Yousef, Nora Hassouneh, Ahmed Malkawi, Naser Abdo, and Marsha C. Kanan. "A Highly Selective Luminescent Sensor for Detecting Mercuric Ions in Water." Australian Journal of Chemistry 62, no. 12 (2009): 1593. http://dx.doi.org/10.1071/ch09048.
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A chemoluminescent sensor utilizing the substrate 2,6-pyridinedicarboxaldehydebis(o-hydroxyphenylimine) (S1) was developed for low-concentration detection of mercuric ions in aqueous solutions. The sensor selectively detects mercury in the presence of sodium, calcium, magnesium, and iron ions. A strong binding was observed between the mercuric ions and the substrate at a pH range of 6.5–7.5, which makes the substrate a distinctive luminescence sensor for detecting mercury at ambient conditions. The sensor shows a linear response towards Hg2+ in the concentration range 5.0 × 10–5 to 2.5 × 10–8 M with a limit of detection of 5.0 × 10–8 M. The sensor can also detect zinc ions at a pH of 10 or higher. The results indicate that this sensor has a promising future for the detection of mercury in real environmental water samples.
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Riani, Etty. "KONTAMINASI MERKURI (Hg) DALAM ORGAN TUBUH IKAN PETEK (Leiognathus equulus) DI PERAIRAN ANCOL, TELUK JAKARTA." Jurnal Teknologi Lingkungan 11, no. 2 (December 2, 2016): 313. http://dx.doi.org/10.29122/jtl.v11i2.1216.
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Mercury (Hg) which is contained in aquatic ecosystem can enter and be accumulated to organism’s body, like on petek fish (Leiognathus equulus). The research aimed to see mercury concentration in aquatic ecosystem, to see mercury concentration in organ of petek fish by AAS (Atomic Absorption Spectrophotometer) and its histopathology response in organs of petek fish. The research was done at Ancol, Jakarta Bay on October-December 2004. There are 16 samples of water and fish from 3 stations.The analysis result of water quality is compared by standard quality of sea water for sea organism life (Kepmen LH No. 51, 2004), mercu ry concentration in fish organ is compared by maximum mercury concentration in fish body by classification of Palar (2004). Ancol water quality is still on normal condition. Mercury concentration in water and petek fish organs had low concentration. Gill and lever contaminated by mercuryis only in station 1 fish, but it is still on normal concentration. Histopathology of petek fish gill is not abnormal, while the lever is necrosis. Water and petek fish is not a good indicator to detect mercury in aquatic ecosystem.Keywords: mercury, petek fish, water, lever, gill, histopathology, accumulation,indicator
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Lombardi, Guido, Antonio Lanzirotti, Clifford Qualls, Francisco Socola, Abdul-Mehdi Ali, and Otto Appenzeller. "Five Hundred Years of Mercury Exposure and Adaptation." Journal of Biomedicine and Biotechnology 2012 (2012): 1–10. http://dx.doi.org/10.1155/2012/472858.
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Mercury is added to the biosphere by anthropogenic activities raising the question of whether changes in the human chromatin, induced by mercury, in a parental generation could allow adaptation of their descendants to mercury. We review the history of Andean mining since pre-Hispanic times in Huancavelica, Peru. Despite the persistent degradation of the biosphere today, no overt signs of mercury toxicity could be discerned in present day inhabitants. However, mercury is especially toxic to the autonomic nervous system (ANS). We, therefore, tested ANS function and biologic rhythms, under the control of the ANS, in 5 Huancavelicans and examined the metal content in their hair. Mercury levels varied from none to 1.014 ppm, significantly less than accepted standards. This was confirmed by microfocused synchrotron X-ray fluorescence analysis. Biologic rhythms were abnormal and hair growth rate per year, also under ANS control, was reduced (P<0.001). Thus, evidence of mercury’s toxicity in ANS function was found without other signs of intoxication. Our findings are consistent with the hypothesis of partial transgenerational inheritance of tolerance to mercury in Huancavelica, Peru. This would generally benefit survival in the Anthropocene, the man-made world, we now live in.
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Blanuša, Maja, Tatjana Orct, Maja Vihnanek Lazarus, Ankica Sekovanić, and Martina Piasek. "Mercury Disposition in Suckling Rats: Comparative Assessment Following Parenteral Exposure to Thiomersal and Mercuric Chloride." Journal of Biomedicine and Biotechnology 2012 (2012): 1–7. http://dx.doi.org/10.1155/2012/256965.
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Due to the facts that thiomersal-containing vaccine is still in use in many developing countries, and all forms of mercury have recognised neurotoxic, nephrotoxic, and other toxic effects, studies on disposition of ethylmercury and other mercury forms are still justified, especially at young age. Our investigation aimed at comparing mercury distribution and rate of excretion in the early period of life following exposure to either thiomersal (TM) or mercuric chloride (HgCl2) in suckling rats. Three experimental groups were studied: control, TM, and HgCl2, with 12 to18 pups in each. Both forms of mercury were administered subcutaneously in equimolar quantities (0.81 μmol/kg b.w.) three times during the suckling period (on the days of birth 7, 9, and 11) to mimic the vaccination regimen in infants. After the last administration of TM or HgCl2, total mercury retention and excretion was assessed during following six days. In TM-exposed group mercury retention was higher in the brain, enteral excretion was similar, and urinary excretion was much lower compared to HgCl2-exposed sucklings. More research is still needed to elucidate all aspects of toxicokinetics and most harmful neurotoxic potential of various forms of mercury, especially in the earliest period of life.
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Krüger, Harald, Michelle S. Thompson, Masanori Kobayashi, Valeria Mangano, Martina Moroni, Anna Milillo, Lindsay P. Keller, et al. "Understanding the Dust Environment at Mercury: From Surface to Exosphere." Planetary Science Journal 5, no. 2 (February 1, 2024): 36. http://dx.doi.org/10.3847/psj/ad11f5.
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Abstract We provide an overview of our understanding of the dust environment at Mercury and the role that dust plays in shaping the planet's surface and exosphere. Our understanding of the role that dust impacts play in the generation of Mercury's atmosphere has evolved considerably with continued analysis of results from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. Recent models have provided evidence for the probable release of refractory species into Mercury's exosphere via impacts. However, there remain significant questions regarding the relative contributions of atoms released via impacts versus other mechanisms (e.g., photon-stimulated desorption) to the overall exospheric budget. We also discuss the state of observational and modeling efforts to constrain the dust environment at Mercury, including sources from the zodiacal cloud, cometary trails, and interstellar dust. We describe the advancements that will be made in our characterization of dust at Mercury with BepiColombo, providing observational constraints on the dust clouds themselves and the role that impacts play in exospheric generation. On Mercury's surface, there remain outstanding questions regarding the role that dust impacts play in the regolith cycling and development. We review how improved modeling efforts to understand grain lifetimes as a function of impactor flux will further our understanding of Mercury's regolith. Finally, there are few constraints on the role of dust impacts on the space weathering of Mercury's surface, particularly the expected chemical, physical, and spectral alterations to the regolith. Here we discuss the importance of laboratory experiments to simulate these processes for the interpretation of data from MESSENGER and BepiColombo.
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Mant, T. G. K., J. L. Lewis, T. K. Mattoo, S. P. A. Rigden, G. N. Volans, I. M. House, A. J. Wakefield, and R. S. Cole. "Mercury Poisoning after Disc-battery Ingestion." Human Toxicology 6, no. 2 (March 1987): 179–81. http://dx.doi.org/10.1177/096032718700600212.
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1 A case is described of a 2-year-old girl who swallowed an alkaline disc battery containing mercuric oxide. Two days after ingestion it disintegrated in the stomach necessitating laparotomy to remove the battery casing and most of its contents. 2 Postoperatively her blood mercury concentration rose to 340 μg/l and subsequently she developed small bowel obstruction due to adhesions. She was treated wth dimercaprol but blood mercury concentrations did not fall until after a second laparotomy to relieve the obstruction and to remove residual mercury salts from the colon. 3 The corrosive effects of swallowed disc batteries are well documented. The maximum blood concentration of mercury reported in this case is 17 times the 'acceptable level of mercury in the blood' and nearly double the highest level recorded previously after disc-battery ingestion. 4 A policy for management of swallowed batteries is suggested.
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Bhattacharya, Soumee, Uma Narang, Kumar Karitkey Yadav, Anshu Dandia, and Shive M. S. Chauhan. "Synthesis of Newer Mercury(II) Complexes of Meso-Tetraaryl-21,23-Dithiaporphyrins." Advanced Science, Engineering and Medicine 12, no. 3 (March 1, 2020): 416–21. http://dx.doi.org/10.1166/asem.2020.2539.
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Due to the larger size of hetero atom and poor binding with metals, N2X2 type of core modified porphyrins show lesser tendency to form metal complexes. Mercury(II) complexes of symmetrical and unsymmetrical meso-tetraaryl-21,23-dithiaporphyrins are synthesized and characterized by the reaction of corresponding meso-tetraaryl-21,23-dithiaporphyrins with mercuric acetate in chloroform/methanol. These mercury complexes are well characterized by their UV-Visible spectra, fluorescence spectra, 1H NMR, 13C NMR and elemental analysis. Soret bands of mercury complex of unsymmetrical 5,20-bis-(4′-methoxyphenyl)-10,15-bisphenyl-21,23-dithiaporphyrin appeared at 442 nm and 462 nm whereas Q band appeared at 516 nm, 560 nm, 620 nm and 714 nm. Appearance of four Q bands is characteristic for this mercury complex of N2X2 type of core modified porphyrins. Mercury complex of unsymmetrical 5,20-bis-(4′-methoxyphenyl)-10,15-bisphenyl-21,23dithiaporphyrin is an excellent fluorescent molecule and showed fluorescence spectrum at 722 nm. These core modified porphyrin complexes provides a good coordination examples of mercury complexes of 21,23-dithiaporphyrins that can be used in sensing applications.
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SEEWAGEN, CHAD L. "Threats of environmental mercury to birds: knowledge gaps and priorities for future research." Bird Conservation International 20, no. 2 (December 11, 2009): 112–23. http://dx.doi.org/10.1017/s095927090999030x.
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SummaryAnthropogenic emissions of mercury have doubled over the past two centuries. Mercury is a dangerous neurotoxin that threatens human health and fish and wildlife populations. The effects of mercury on birds have been relatively well-studied in the laboratory and in nature. Several aspects of neurology, physiology, behaviour, and reproduction have been shown to be adversely affected. Many studies have documented ataxia, lethargy, reduced appetite, reduced egg production, poor hatching success, and aberrant parental care in birds exposed to mercury.The majority of the research done to date, however, has been focused on select taxa (waterbirds), trophic levels (piscivores), habitat types (aquatic systems), geographic regions (North America and Europe), and life history stages (reproduction), leaving the assessment of mercury's threats to birds incomplete. Successful bird conservation strategies are dependent on a comprehensive understanding of the threats facing populations. Here, I discuss the significant knowledge gaps that remain and subsequently suggest priorities for future mercury research in birds. Studies of mercury in terrestrial, insectivorous, and/or passerine species, and how mercury affects migration are especially recommended to fill gaps in our present understanding.
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Suzuki, T., T. Hongo, N. Matsuo, H. Imai, M. Nakazawa, T. Abe, Y. Yamamura, M. Yoshida, and H. Aoyama. "An Acute Mercuric Mercury Poisoning: Chemical Speciation of Hair Mercury Shows a Peak of Inorganic Mercury Value." Human & Experimental Toxicology 11, no. 1 (January 1992): 53–57. http://dx.doi.org/10.1177/096032719201100109.
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A woman ingested a dose of sublimate (approximately 0.9 g) in an attempted suicide. She survived and recovered in response to a combination of therapies including chelate (BAL) therapy, plasma exchange, haemodialysis and peritoneal dialysis. Serum inorganic mercury concentration, urinary inorganic mercury excretion and hair inorganic and organic mercury and selenium concentrations, along the length from the scalp to the distal part, were measured. Longitudinal analysis of hair, revealed a peak in inorganic mercury corresponding to the time of mercury ingestion. Organic mercury and selenium in the hair had different patterns of longitudinal variation from that of inorganic mercury. The biological half-life (23.5 d) of serum inorganic mercury levels was in good agreement with values previously reported in the literature.
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Hagele, Thomas J., Jessica N. Mazerik, Anita Gregory, Bruce Kaufman, Ulysses Magalang, M. Lakshmi Kuppusamy, Clay B. Marsh, Periannan Kuppusamy, and Narasimham L. Parinandi. "Mercury Activates Vascular Endothelial Cell Phospholipase D through Thiols and Oxidative Stress." International Journal of Toxicology 26, no. 1 (January 2007): 57–69. http://dx.doi.org/10.1080/10915810601120509.
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Currently, mercury has been identified as a risk factor of cardiovascular diseases among humans. Here, the authors tested the hypothesis that mercury modulates the activity of the endothelial lipid signaling enzyme, phospholipase D (PLD), which is an important player in the endothelial cell (EC) barrier functions. Monolayers of bovine pulmonary artery ECs (BPAECs) in culture, following labeling of membrane phospholipids with [32P]orthophosphate, were exposed to mercuric chloride (inorganic form), methylmercury chloride (environmental form), and thimerosal (pharmaceutical form), and the formation of phosphatidylbutanol as an index of PLD activity was determined by thin-layer chromatography and liquid scintillation counting. All three forms of mercury significantly activated PLD in BPAECs in a dose-dependent (0 to 50 μM) and time-dependent (0 to 60 min) fashion. Metal chelators significantly attenuated mercury-induced PLD activation, suggesting that cellular mercury-ligand interaction(s) is required for the enzyme activation and that chelators are suitable blockers for mercury-induced PLD activation. Sulfhydryl (thiol-protective) agents and antioxidants also significantly attenuated the mercury-induced PLD activation in BPAECs. Enhanced reactive oxygen species generation, as an index of oxidative stress, was observed in BPAECs treated with methylmercury that was attenuated by antioxidants. All the three different forms of mercury significantly induced the decrease of levels of total cellular thiols. For the first time, this study revealed that mercury induced the activation of PLD in the vascular ECs wherein cellular thiols and oxidative stress acted as signal mediators for the enzyme activation. The results underscore the importance of PLD signaling in mercury-induced endothelial dysfunctions ultimately leading to cardiovascular diseases.
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Naguib, Martha M., Ahmed O. El-Gendy, and Ahmed S. Khairalla. "Microbial Diversity of Mer Operon Genes and Their Potential Rules in Mercury Bioremediation and Resistance." Open Biotechnology Journal 12, no. 1 (April 30, 2018): 56–77. http://dx.doi.org/10.2174/1874070701812010056.
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Background:Mercury is a toxic metal that is present in small amounts in the environment, but its level is rising steadily, due to different human activities, such as industrialization. It can reach humans through the food chain, amalgam fillings, and other sources, causing different neurological disorders, memory loss, vision impairment, and may even lead to death; making its detoxification an urgent task.Methods:Various physical and chemical mercury remediation techniques are available, which generally aim at: (i) reducing its mobility or solubility; (ii) causing its vaporization or condensation; (iii) its separation from contaminated soils. Biological remediation techniques, commonly known as bioremediation, are also another possible alternative, which is considered as cheaper than the conventional means and can be accomplished using either (i) organisms harboring themeroperon genes (merB,merA,merR,merP,merT,merD,merF,merC,merE,merHandmerG), or (ii) plants expressing metal-binding proteins. Recently, differentmerdeterminants have been genetically engineered into several organisms, including bacteria and plants, to aid in detoxification of both ionic and organic forms of mercury.Results:Bacteria that are resistant to mercury compounds have at least a mercuric reductase enzyme (MerA) that reduces Hg+2to volatile Hg0, a membrane-bound protein (MerT) for Hg+2uptake and an additional enzyme, MerB, that degrades organomercurials by protonolysis. Presence of bothmerA andmerB genes confer broad-spectrum mercury resistance. However,merA alone confers narrow spectrum inorganic mercury resistance.Conclusion:To conclude, this review discusses the importance of mercury-resistance genes in mercury bioremediation. Functional analysis ofmeroperon genes and the recent advances in genetic engineering techniques could provide the most environmental friendly, safe, effective and fantastic solution to overcome mercuric toxicity.
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Simbahan, Jessica, Elizabeth Kurth, James Schelert, Amanda Dillman, Etsuko Moriyama, Stevan Jovanovich, and Paul Blum. "Community Analysis of a Mercury Hot Spring Supports Occurrence of Domain-Specific Forms of Mercuric Reductase." Applied and Environmental Microbiology 71, no. 12 (December 2005): 8836–45. http://dx.doi.org/10.1128/aem.71.12.8836-8845.2005.
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ABSTRACT Mercury is a redox-active heavy metal that reacts with active thiols and depletes cellular antioxidants. Active resistance to the mercuric ion is a widely distributed trait among bacteria and results from the action of mercuric reductase (MerA). Protein phylogenetic analysis of MerA in bacteria indicated the occurrence of a second distinctive form of MerA among the archaea, which lacked an N-terminal metal recruitment domain and a C-terminal active tyrosine. To assess the distribution of the forms of MerA in an interacting community comprising members of both prokaryotic domains, studies were conducted at a naturally occurring mercury-rich geothermal environment. Geochemical analyses of Coso Hot Springs indicated that mercury ore (cinnabar) was present at concentrations of parts per thousand. Under high-temperature and acid conditions, cinnabar may be oxidized to the toxic form Hg2+, necessitating mercury resistance in resident prokaryotes. Culture-independent analysis combined with culture-based methods indicated the presence of thermophilic crenarchaeal and gram-positive bacterial taxa. Fluorescence in situ hybridization analysis provided quantitative data for community composition. DNA sequence analysis of archaeal and bacterial merA sequences derived from cultured pool isolates and from community DNA supported the hypothesis that both forms of MerA were present. Competition experiments were performed to assess the role of archaeal merA in biological fitness. An essential role for this protein was evident during growth in a mercury-contaminated environment. Despite environmental selection for mercury resistance and the proximity of community members, MerA retains the two distinct prokaryotic forms and avoids genetic homogenization.
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Watters, Thomas R., James W. Head, Sean C. Solomon, Mark S. Robinson, Clark R. Chapman, Brett W. Denevi, Caleb I. Fassett, Scott L. Murchie, and Robert G. Strom. "Evolution of the Rembrandt Impact Basin on Mercury." Science 324, no. 5927 (May 2009): 618–21. http://dx.doi.org/10.1126/science.1172109.
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MESSENGER from Mercury The spacecraft MESSENGER passed by Mercury in October 2008, in what was the second of three fly-bys before it settles into the planet's orbit in 2011. Another spacecraft visited Mercury in the mid-1970s, which mapped 45% of the planet's surface. Now, after MESSENGER, only 10% of Mercury's surface remains to be imaged up close. Denevi et al. (p. 613 ) use this near-global data to look at the mechanisms that shaped Mercury's crust, which likely formed by eruption of magmas of different compositions over a long period of time. Like the Moon, Mercury's surface is dotted with impact craters. Watters et al. (p. 618 ) describe a well-preserved impact basin, Rembrandt, which is second in size to the largest known basin, Caloris. Unlike Caloris, Rembrandt is not completely filled by material of volcanic origin, preserving clues to its formation and evolution. It displays unique patterns of tectonic deformation, some of which result from Mercury's contraction as its interior cooled over time. Mercury's exosphere and magnetosphere were also observed (see the Perspective by Glassmeier ). Magnetic reconnection is a process whereby the interplanetary magnetic field lines join the magnetospheric field lines and transfer energy from the solar wind into the magnetosphere. Slavin et al. (p. 606 ) report observations of intense magnetic reconnection 10 times as intense as that of Earth. McClintock et al. (p. 610 ) describe simultaneous, high-resolution measurements of Mg, Ca, and Na in Mercury's exosphere, which may shed light on the processes that create and maintain the exosphere.