polycyclic aromatic hydrocarbons (pahs) are toxic pollutants released by various urban combustion sources. tehran is the largest city in iran with a population of about 8 million and it is faced with serious air quality problems. the gas phase samples collected from 21 sites in tehran area throughout year 2005. the samples‘ pahs were collected using a skc trapping consisting of glass cartridg...

During spring of 2009, a new influenza virus AH1N1 spread in the world causing acute respiratory illness and death, resulting in the first influenza pandemic since 1968. Blood levels of potentially-toxic and essential elements of 40 pneumonia and confirmed AH1N1 were evaluated against two different groups of controls, both not infected with the pandemic strain. Significant concentrations of pot...

Ni is recognized as an element that is toxic to humans, acting as an allergen and a carcinogenic agent, and it is also toxic to plants. The toxicity of Ni has been understudied in microorganisms. The data presented here were obtained by submitting the model bacterium Escherichia coli K-12 to nickel stress. To identify expressed genes, RNA-Seq was performed. Bacteria were exposed to 50 µM NiCl2 ...

Multicomponent efflux complexes constitute a primary mechanism for Gram-negative bacteria to expel toxic molecules for survival. As these complexes traverse the periplasm and link inner and outer membranes, it remains unclear how they operate efficiently without compromising periplasmic plasticity. Combining single-molecule superresolution imaging and genetic engineering, we study in living Esc...

Many of the trace elements which have essential roles in animals, such as zinc (Zn), manganese (Mn) and copper (Cu), are required for the growth, development and maintenance of healthy bones (Rucker, 1988; Leach, 1988). Of the remaining trace or ultratrace elements, which by definition are normally present at low concentrations in animal tissues, some have a toxic effect on bone such as lead (P...

Selenium, an element long known to be toxic to living organisms (1, 2), has only recently been implicated as an essential trace element for rats (3), chicks (4,5) and several other animals. The work of Franke (6), Horn et cd. (7), Painter (8, 9), and McConnell (10, 11) established that if toxic amounts of selenium were supplied in various chemical forms to a number of plants, animals, and micro...

Problem statement: Defining of correlation between toxic and essential elements in human beings is an important clinical screening procedure. Approach: The aim of this study was to determine the correlation between cadmium as toxic element and calcium as an essential element in the blood at the smokers. We have investigated 50 human blood samples of different ages and genders (age: 35-45 years ...

In 1957, Schwarz and Foltz discovered that selenium (Se) was an essential trace mineral and nutritionists then started extensive studies to figure out the metabolic function of this element which has been called as toxic mineral. The discovery that glutathione peroxidase (GSH-Px) contained Se demonstrated a biochemical role for Se as an essential trace element. The major physiological function ...