نتایج جستجو برای: non toxic metals

تعداد نتایج: 1434745  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1391

in this research we have studied the effect of some transition-metals (cu, ag and au) substitutions on two-electron reduction potential of flavins by application of dft method. all geometries have been optimized at blyp level of theory and “6-31+g** + lanl2dz” mixed basis set. the frequency job at the same method and basis sets has been performed to obtain gibbs free energy of compounds. it h...

Journal: :The Indian journal of medical research 2008
S J S Flora Megha Mittal Ashish Mehta

Exposure to heavy metals is a common phenomenon due to their environmental pervasiveness. Metal intoxication particularly neurotoxicity, genotoxicity, or carcinogenicity is widely known. This review summarizes our current understanding about the mechanism by which metalloids or heavy metals (particularly arsenic, lead, cadmium and mercury) induce their toxic effects. The unifying factor in dete...

2013
Sardar Patel

In recent years, heavy metal pollution has become one of the most serious environmental problems. The pollution of environment with toxic heavy metals is spreading throughout the world along with industrial progress. Presence of heavy metals even in traces is toxic and detrimental to all living organisms. Moreover it cannot be degraded in to simpler harmless compounds like other pollutants incl...

2016
Harold I. Zeliger

The onset of non-communicable disease has been attributed in large part to environmental exposure to toxic chemicals, including persistent organic pollutants, volatile and semi-volatile organic compounds and transition metals. This review summarizes recent research into the causes and mechanisms of environmental disease onset and examines the role of oxidative stress as well as steps that can b...

Journal: :international journal of environmental research 2014
w. rogula-kozłowska b. błaszczak p. rogula-kopiec k. klejnowski b. mathews

24-hour samples of pm1 (submicron particles, aerodynamic diameters ≤1 μm) and pm2.5(fine particles, aerodynamic diameters ≤ 2.5 μm) were collected at a quasi-rural area in racibórz (1 january-30 june 2011). the samples were analysed for carbon (organic and elemental), water-soluble ions (na+,nh4 +, k+, mg2+, ca2+, cl-, no3 -, so4 2-) and concentrations of 21 elements with a carbon analyser (sun...

2013
A. Mudhoo S. Kumar

Heavy metals affect the biochemical reactions that take place during anaerobic digestion processes of organic matter. In this review, the different effects observed in anaerobic digestion processes and during the production of biomethane and biohydrogen from several substrates contaminated with and/or inheriting heavy metals from the substrates themselves were discussed. It has been found that ...

2017
Robin D. Calfee Edward E. Little

The Chiricahua leopard frog (Lithobates chiricahuensis) is in decline throughout the western United States, and is particularly sensitive to physical, chemical and biotic changes in their habitat. Acute toxicity tests revealed that among the metals detected in Chiricahua leopard frog habitat, copper was toxic at concentrations lower than those observed in the environment. Developing tadpoles we...

2012
Yu-Jin Kim Ok Ran Lee Sungyoung Lee Kyung-Tack Kim Deok-Chun Yang

Plants have versatile detoxification systems to encounter the phytotoxicity of the wide range of natural and synthetic compounds present in the environment. Glutathione S-transferase (GST) is an enzyme that detoxifies natural and exogenous toxic compounds by conjugation with glutathione (GSH). Recently, several roles of GST giving stress tolerance in plants have demonstrated, but little is know...

2008
aTEFAN VALENTIN BRANESCU ALEXANDRU POPESCU

Heavy metals are natural components of Earth’s crust. They cannot be degraded or destroyed. The impurification of water surfaces with heavy metals usually has disastrous effects on the environment. That’s why the determination of heavy metals concentrations at levels of ppm or ppb is strictly necessary. Industrial, economical and demographic development generates huge amounts of wastes which ha...

Journal: :Environmental science and pollution research international 2015
Vanessa A Mesquita Manuela D Machado Cristina F Silva Eduardo V Soares

Metal contamination of the environment is frequently associated to the presence of two or more metals. This work aimed to study the impact of a mixture of metals (Cd, Pb and Zn) on the physiology of the non-conventional yeast Pichia kudriavzevii. The incubation of yeast cells with 5 mg/l Cd, 10 mg/l Pb and 5 mg/l Zn, for 6 h, induced a loss of metabolic activity (assessed by FUN-1 staining) and...

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