نتایج جستجو برای: toxic of mercury
تعداد نتایج: 21170844 فیلتر نتایج به سال:
Mercury (Hg) occurs naturally in the environment and has been used in numerous medicinal, commercial, and industrial applications over many centuries. Also, it has played significant historical, as well as current, ethno-medical and magico-religious roles in a number of different cultures. In recent times, awareness has emerged that exposure to mercury can have serious adverse health consequenc...
Bacteria resistant to methylmercury utilize two enzymes (MerA and MerB) to degrade methylmercury to the less toxic elemental mercury. The crucial step is the cleavage of the carbon-mercury bond of methylmercury by the organomercurial lyase (MerB). In this study, we determined high resolution crystal structures of MerB in both the free (1.76-A resolution) and mercury-bound (1.64-A resolution) st...
Despite decades of scientific research and policy actions to control mercury, exposure to toxic methylmercury continues to pose risks to humans and the environment. This article critically reviews the linkages between scientific advancements and mercury reduction policies aimed at reducing this risk, focusing on the challenges that mercury poses as an issue that crosses both spatial and tempora...
Mercury at low concentrations represents a major hazard to microorganisms. Inorganic mercury has been reported to produce harmful eects at 5 lg/l in a culture medium. Organomercury compounds can exert the same eect at concentrations 10 times lower than this. The organic forms of mercury are generally more toxic to aquatic organisms and birds than the inorganic forms. Aquatic plants are aecte...
The purpose of this paper is to examine and report on studies that relate mercury levels in human tissues to the presence of dental amalgams, giving special attention to autopsy studies. Until recently, there have been few published studies examining the relationship between dental amalgams and tissue mercury levels. Improved and highly sensitive tissue analysis techniques have made it possible...
During the past decade, considerable concern has been expressed by environmental scientists over the increasing levels of a range of toxic elements in the environment. Among the most potentially hazardous are the so-called ‘heavy metals’, a term applied to cover a range of transition elements, including copper, zinc and nickel and other elements such as cadmium, mercury and lead. Acutely toxic ...
Background Mercury exists in multiple forms: elemental, organic, and inorganic. Its toxic manifestations depend on the type and magnitude of exposure. The role of colonoscopic decompression in acute mercury toxicity is still unclear. We present a case of acute elemental mercury toxicity secondary to mercury ingestion, which markedly improved with colonoscopic decompression. Clinical Case A 54...
INTRODUCTION The purpose of this clinical study was to compare the blood mercury levels before and after endodontic surgery using amalgam as a root-end filling material. MATERIALS AND METHODS Fourteen patients requiring periradicular surgery participated in this prospective clinical study. A zinc-free amalgam was employed as root-end filling material. Blood samples were collected at three int...
Mercury is a toxic metal and is used in small scale gold mining. In Portovelo, Ecuador, mercury has been an environmental and health problem for decades. The target of this study was to assess the mercury concentration in the urine of miners from Portovelo/Zaruma to establish a prevalence of high values. Eight hundred and sixty-five (865) urine samples were collected and analysed for their merc...
In order to elucidate the role of erythrocyte catalase in the accumulation of mercury in erythrocytes, labeled erythrocytes and plasma were prepared by exposing normal and acatalasemic mice to radioactive mercury vapor (203Hg0: 6.8mg/m3) for 30 min. Labeled erythrocytes (or plasma) were mixed with unlabeled plasma (or erythrocytes) of normal or acatalasemic mice and incubated at 0 degrees C for...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید