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Friday, 28 May 2010 07:02 |
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The aim of the present study was to investigate the levels of cadmium in sheep’s muscle, liver and kidney from Isfahan and also to compare them with the levels reported in several other countries and with the maximum tolerance levels for the human consumption. The samples of muscle, liver and kidney of 60 animals around 1 to 6 years old were collected from the carcasses slaughtered in Flavarjan abattoir, Isfahan. Samples (acid digested and cadmium concentrations) were determined by graphite furnace atomic absorption spectrophotometry (GFAAS). The mean fresh weight concentrations in muscle, liver and kidney were about 0.0017 mg/kg, 0.0743 mg/kg and 0.02290 mg/kg, respectively. The mean concentration of cadmium in tissue samples was generally lower than the maximum acceptable concentra... |
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Friday, 28 May 2010 07:02 |
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Arsenic is an ubiquitous and well-documented carcinogenic metalloid. The most common source of arsenic is drinking water. The mechanism of arsenic toxicity in a cell has historically been centered around its inhibitory effects on cellular respiration and mitochondrial injury. Ascorbic acid, a low molecular weight, water-soluble antioxidant, improves the reduced glutathione (GSH) status by recycling oxidized glutathione. Ascorbic acid can improve mitochondrial function by improving the thiol status; thereby preventing reactive oxygen species— mediated damage to liver as well as kidney. Ascorbic acid has been shown to protect membrane and other cellular compartments by regenerating vitamin E. Therefore, ascorbic acid seems to be a suitable protective factor against arsenic toxicity. Pr... |
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Friday, 07 May 2010 00:00 |
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At an April 29 presentation to the Pesticide Programs Dialogue Committee in Washington, D.C. EPA’s William Jordan announced a new working definition of nanomaterials. |
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Monday, 26 April 2010 00:00 |
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A new report defines the criteria for a new technology assessment function in the United States, emphasizing the need to incorporate citizen-participation methods to complement expert analysis. |
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Thursday, 22 April 2010 06:22 |
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The binding of Cd2+ to human serum transferrin in 0.1 M N-(2-hydroxyethyl) piperazine-N '-2-ethanesulfonic acid and 5 mM sodium bicarbonate at pH 7.4 has been studied by difference ultraviolet spectrophotometry. The apparent association constants were found to be 2.61 x 105 M —1 and 8.51 x 104M— 1, respectively. These association constants are pH-dependent, reducing with both increasing and decreasing pH. The apparent pKa values were found to be 4.93 and 5.42. Competitive assays of binding of Cd2+ to transferrin in the presence of citrate and human serum albumin at molar ratios corresponding to those found in normal plasma showed that a considerable amount of Cd2+ was not bound to transferrin. The competitive binding assays indicate that ~50% of Cd2+ is bound to transferrin, ~3... |
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Thursday, 22 April 2010 06:22 |
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Many investigations have shown that nickel exposure can induce micronuclei generation, inhibit DNA repair and induce cell apoptosis, both in cells and tissues. However, there is a lack of appropriate in vivo animal models to study the underlying mechanisms of nickel-induced apoptosis. The model organism, Caenorhabditis elegans, has been shown to be a good model for investigating many biological processes. In the present study, we detected 0.01 mM nickel induced significantly germline cell apoptosis after treatment for 12 hours, which demonstrated that C. elegans could be a mammalian in vivo substitute model to study the mechanisms of apoptosis. Then gene knockout C. elegans strains were utilized to investigate the relationship between nickel-induced apoptosis and relevant signal pathways, ... |
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Thursday, 22 April 2010 06:22 |
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In conclusion, exposure to H 2S among sewer network workers is associated with cognitive impairment, which can be screened by applying MMSE as a simple rapid test for H 2S occupationally exposed workers. (Source: Toxicology and Industrial Health current issue) |
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Thursday, 22 April 2010 06:22 |
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The present study dealt with the decolorization of textile dye Reactive Black-5 by actively growing mycelium of Aspergillus niger MT-1 in molasses medium. It was found that the fungus, which was isolated from the effluent of sugar fabric-contaminated soil, was capable of decolorizing the Reactive Black-5 dye in a wide range of temperature, shaking speed and pH values. The experiments also revealed that highest dye decolorization efficiency was achieved with cheap carbon (molasses sucrose) and nitrogen (ammonium chloride) sources. Under the optimized culture conditions, the complete decolorization (100%) of 0.1 g/L dye was achieved in 60 hours. The dominant mechanism of dye removal by the fungus was found to be probably bioaccumulation. Fungal growth in small uniform pellet form was found t... |
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Thursday, 22 April 2010 06:22 |
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Hydrogen-dissolved water has been suggested to be effective for alleviating the oxidative stress. In the present study, neutral-pH hydrogen-enriched electrolyzed water (NHE-water; dissolved hydrogen: 0.90—1.14 parts per million [ppm]; oxido-reduced potential: —150 ~ —80 mV), which was prepared with a water-electrolysis apparatus equipped with a non-diaphragm cell and a highly compressed activated-carbon block, was evaluated for the mutagenic and genotoxic potentials, at concentrations up to 100% dose/plate, and for the subchronic toxicity. NHE-water did not induce reverse mutations in Salmonella typhimurium strains TA100, TA1535, TA98 and TA1537, and Escherichia coli strain WP2uvrA, in either the absence or presence of rat liver S9 for exogenous metabolic activation. Simi... |
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Thursday, 22 April 2010 06:22 |
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A reliable method is needed for assessing the condition of aquatic animals and their resistance to toxic pollutants. The physiological responses of two freshwater crustaceans, Asellus aquaticus and Gammarus fossarum, following in vitro exposure to two pesticides (atrazine and imidacloprid), were measured by a combination of electron transport system (ETS) activity and respiration (R). Short-term exposure concentrations were selected according to standard toxicity tests and ranged from 0.01 mg L—1 to 10 mg L—1. When pesticide concentration was greater than 1 mg l— 1 (which is below the LC50 [48 hours] determined for both species), A. aquaticus and G. fossarum responded to short-term exposure with elevated levels of R and/or lower levels of ETS activity. One hour exposure t... |
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