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101.
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The aim of this study was to evaluate the incidence of total aflatoxin (AF), ochratoxin A, T-2 toxin, deoxynivalenol (DON), zearalenone (ZEA), and fumonisin (FB) in dairy cattle, beef cattle, and lamb–calf feeds. A total of 180 dairy cattle, beef cattle, and lamb–calf feeds (60 samples each) were randomly collected from farms, feed mills, and villages in Burdur province, between September 2006 and August 2007. All samples were analyzed by the competitive Enzyme Linked Immuno Sorbent Assay (ELISA). The most frequent mycotoxin detected was total AF, which was found in 108 samples (60 %) in concentrations ranging from 3.82 to 116.83 μg?kg?1, followed by DON that was detected in 87 samples (48.3 %), in concentrations ranging from 18.50 to 500 μg?kg?1. Ochratoxin A (OTA), T-2 toxin, ZEA, and FB were found in 84 (46.7 %), 85 (47.2 %), 57 (31.7 %), and 19 (10.6 %) samples, respectively, in concentrations of 1.01 to 15.85 μg?kg?1 for OTA, 3.85 to 52.36 μg?kg?1 for T-2 toxin, 2.10 to 29.30 μg?kg?1 for ZEA, and 2.69 to 4.96 mg?kg?1 for FB. It was concluded that feed samples in Burdur province were contaminated by mycotoxins, and the levels of total aflatoxin in the samples were considered a risk to animal health.  相似文献   
103.
The rate of heavy metal pollution in some minor fruit samples growing at roadsides in Turkey were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The mineral contents of samples were found to be different depending on the several parts Citrus fruits. The highest minor and heavy metal levels for Citrus fruits were determined between 17.24 and 45.30 mg/kg boron, 2.08 and 15.05 mg/kg copper, 1.01 and 16.00 mg/kg iron and 2.35 and 9.87 mg/kg zinc. Boron content ranged from 16.54 mg/kg (Deveci pear inner pulp) to 89.89 mg/kg (Arjantin apple outer skin). The level of Fe ranged from 1.49 mg/kg (quince pulp) to 25.05 mg/kg (Ankara pear pulp). Cu content of fruits ranged between 2.52 mg/kg (Fuji apple skin) and 25.93 mg/kg quince skin). Zn content was found between 0.46 mg/kg (Golden apple pulp) and 14.34 mg/kg (quince skin). P contents ranged from 651 mg/kg (Golden apple pulp) to 1269 mg/kg (quince skin). Na was found between 500 mg/kg (Fuji apple skin) and 907 mg/kg (Arjantin apple skin).  相似文献   
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The objective of this study was to examine the effects of vegetation change from a native broadleaf forest to a coniferous plantation on selected soil properties, including soil texture, pH, organic matter, total nitrogen (N), total phosphorus (P), exchangeable cations (Ca2+, K+, Na+), and cation exchange capacity (CEC). Results showed that the amount of clay particles, Ca2+, and K+ values significantly increased, whereas Na+, total N, and organic matter and soil pH values decreased on the treatment plot after vegetation change. Soil acidity also increased and soil textural group changed from moderately fine-textured soils (clay loam) to medium-textured soils (loam) under both control and treatment plots. Organic matter, total N, and Na+ values increased, whereas Ca2+ concentration decreased through time on the control plot. Soil pH, total P, K+, and CEC did not show significant changes through time on the control plot.  相似文献   
107.
Desorption of cadmium from goethite: effects of pH, temperature and aging   总被引:1,自引:0,他引:1  
Mustafa G  Kookana RS  Singh B 《Chemosphere》2006,64(5):856-865
Cadmium is perhaps environmentally the most significant heavy metal in soils. Bioavailability, remobilization and fate of Cd entering in soils are usually controlled by adsorption-desorption reactions on Fe oxides. Adsorption of Cd on soil colloids including Fe oxides has been extensively studied but Cd desorption from such soil minerals has received relatively little attention. Some factors that affect Cd adsorption on goethite include pH, temperature, aging, type of index cations, Cd concentrations, solution ionic strength and presence of organic and inorganic ions. This research was conducted to study the influence of pH, temperature and aging on Cd desorption from goethite. Batch experiments were conducted to evaluate Cd desorption from goethite with 0.01 M Ca(NO3)2. In these experiments Cd desorption was observed at 20, 40 and 70 degrees C in combination with aging for 16 h, 30, 90 and 180 d from goethite that adsorbed Cd from solutions containing initial Cd concentrations of 20, 80 and 180 microM. Following the adsorption step Cd desorption was measured by 15 successive desorptions after aging at various temperatures. At the lowest amount of initially adsorbed Cd and equilibrium pH 5.5, cumulative Cd desorption decreased from 71% to 17% with aging from 16 h to 180 d and the corresponding decrease at equilibrium pH 6.0 was from 32% to 3%. There was a substantial decrease in Cd desorption with increasing equilibration temperature. For example, in goethite with the lowest amount of initial adsorption at equilibrium pH 5.5, cumulative Cd desorption decreased from 71% to 31% with increase in temperature from 20 to 70 degrees C, even after 16 h. Dissolution of Cd adsorbed goethite in 1M HCl, after 15 successive desorptions with 0.01 M Ca(NO3)2, indicated that approximately 60% of the Cd was surface adsorbed. Overall, dissolution kinetics data revealed that 23% to 88% Cd could not be desorbed, which could possibly be diffused into the cracks and got entrapped in goethite crystals. At elevated temperature increased equilibrium solution pH favoured the formation of CaCO3 and CdCO3 which reasonably decreased Cd desorption. Cadmium speciation showed the formation of calcite and otavite minerals at 40 and 70 degrees C due to increase in pH (>9.5) during aging. X-ray diffraction analysis (XRD) of these samples also revealed the formation of CaCO3 at elevated temperatures with aging. While mechanisms such as Cd diffusion and/or entrapment into fissures and cracks in goethite structure with increase in temperature and aging are possible.  相似文献   
108.
The species differences in the neurotoxic and delayed neurotoxic potential of monocrotophos (MCP) were assessed by determining the in vitro inhibition of brain Acetylcholinesterase (AChE) and Neuropathic target esterase (NTE) in rat, mice, chicken and pigeon. Based on I50 values, chicken brain AChE was found to be most sensitive to inhibition by MCP followed by rat whereas mice and pigeon were almost equally sensitive to AChE inhibition by MCP. The data on NTE inhibition by MCP in all the four species indicate the non-delayed neurotoxic nature of MCP. The results show that although there are many common features of the brain AChE and NTE of the four non-target organisms studied, certain species characteristics exist in their inhibition responses to MCP.  相似文献   
109.
Heavy metal (Cd, Cr, Cu, Fe, Pb, Zn) concentrations in the muscle, gill and liver of six fish species (Sparus auratus, Atherina hepsetus, Mugil cephalus, Trigla cuculus, Sardina pilchardus and Scomberesox saurus) from the northeast Mediterranean Sea were measured and the relationships between fish size (length and weight) and metal concentrations in the tissues were investigated by linear regression analysis. Metal concentrations (as microg/g d.w.) were highest in the liver, except for iron in the gill of Scomberesox sauris and lowest in the muscle of all the fish species. Highest concentrations of Cd (4.50), Cr (17.1) and Pb (41.2) were measured in liver tissues of T. cuculus, Sardina pilchardus and A. hepsetus, respectively. The liver of M. cephalus showed strikingly high Cu concentrations (202.8). The gill of Scomberesox saurus was the only tissue that showed highest (885.5) iron concentrations. Results of linear regression analysis showed that, except in a few cases, significant relationships between metal concentrations and fish size were negative. Highly significant (P<0.001) negative relationships were found between fish length and Cr concentrations in the liver of A. hepsetus and M. cephalus, and Cr concentrations in the gill of T. cuculus. Cr and Pb concentrations in the liver and Cu concentrations in all the tissues of Scomberesox saurus also showed very significant (P<0.001) negative relationships. Negative relationships found here were discussed.  相似文献   
110.
The influence of copper(II)chloride on selected key enzymes and metabolites in intermediary metabolism and the energy charge potential of the hyperregulating shore crab, Carcinus maenas (L.) were investigated. Crabs, collected in Odense Fjord, Denmark between September 1989 and May 1990, were exposed to 10 ppm copper(II)chloride, in 10 ppt salinity seawater at 15°C for up to 1 wk. Hexokinase activity was 77% lower in the posterior gills and 60% lower in the midgut gland than in control crabs. Phosphofructokinase activity was reduced in the midgut gland by 82% but was unaffected in the gills. Pyruvate kinase activity was undetectable in the gills of exposed crabs and reduced by 47% in the midgut gland. Citrate synthase activity was depressed by 30% in the posterior gills and unaffected in other tissues. Copper exposure had no apparent effect on tissue cytochrome c oxidase activity. Chela muscle was the only tissue in which copper exposure did not bring about reductions in the enzyme activities tested. As a result of 1 wk of copper exposure the average lactate level increased by 3.5-fold in haemolymph, 9.3-fold in posterior gills and 6.5-fold in midgut gland. The average glucose level was raised by a factor of 6 in the haemolymph, 3.4 in the posterior gills and 1.2 in the midgut gland. Energy charge potential was at a very high level (ca. 0.9) and was unaffected by copper exposure.  相似文献   
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