نتایج جستجو برای: toxic element
تعداد نتایج: 279456 فیلتر نتایج به سال:
This report on a male head revealed biologic rhythms, as gleaned from hydrogen isotope ratios in hair, consistent with a South-American origin and Atomic Mass Spectrometry radiocarbon dating (AMS) compatible with the last pre-Hispanic period (1418-1491 AD, 95.4% probability). Biopsies showed exceptionally well-preserved tissues. The hair contained high levels of toxic elements (lead, arsenic an...
The MicrotoxTM bioassay and polarographic techniques were used together to identify specific oxidation states and toxicity of metals. The bioassay is based on light reduction by bioluminescent bacteria upon exposure to toxicants. In polarography, a mercury drop substrate’s potential is changed, and the substance of interest is electrochemically reduced. Reduction current is proportional to its ...
Knowledge of the dietary intake of essential and toxic elements in fast-developing Southeast Asian countries such as Vietnam is limited. Iron and Zn deficiency in Asia is a well-known problem and is partly due to rice constituting a major part of the diet. Dietary habits are changing and there is a need to build more knowledge so authorities can give dietary recommendations. The aim of this stu...
In clinical medicine, increasing attention is being directed towards the important areas of nutritional biochemistry and toxicant bioaccumulation as they relate to human health and chronic disease. Optimal nutritional status, including healthy levels of vitamin D and essential minerals, is requisite for proper physiological function; conversely, accrual of toxic elements has the potential to im...
fossil fuel power plant is one of the most important sources of environmental pollution of the vanadium toxic metal. this survey showed that the penicilium austuranium is the best microorganism for biosorption of vanadium isolated from environment of fossil fuel power plant. to determine the optimum ph and most biosorption and accumulation of vanadium by these fungi, power plants wastewater, pa...
background: l1 retrotransposons are the most active mobile dna elements in human genome. unregulated l1 retrotransposition may have deleterious effect by disrupting vital genes and inducing genomic instabilities. therefore, human cells control l1 elements by silencing their activities through epigenetic mechanisms. it has been shown that cell division and heavy metals stimulate the frequency of...
mercury is a dangerous and an extremely toxic element, which can transfer to the food chain.presence of this element in the atmosphere particularly during the rainy seasons cause soil and environmental pollution, therefore this research will evaluate the transformation of mercury vapor from the atmosphere through precipitation into the soil. in the present study, mercury concentrations were det...
1. The blood-brain barrier (BBB) contributes to brain homeostastis and fulfills a protective function by controlling the access of solutes and toxic substances to the central nervous system (CNS). The efflux transporter P-glycoprotein (P-gp) is a key element of the molecular machinery that confers special permeability properties to the BBB. 2. P-gp, which was initially recognized for its abilit...
Since sodium, Na, is a non-essential element for the plant growth, the molecular mechanism of Na(+) transport system in plants has remained elusive for the last two decades. The accumulation of Na(+) in soil through irrigation for sustainable agricultural crop production, particularly in arid land, and by changes in environmental and climate conditions leads to the buildup of toxic level of sal...
Aluminum (Al) is the most abundant metal in the earth's crust, but its availability depends on soil pH. Despite this abundance, Al is not considered an essential element and so far no experimental evidence has been put forward for a biological role. In plants and other organisms, Al can have a beneficial or toxic effect, depending on factors such as, metal concentration, the chemical form of Al...
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