نتایج جستجو برای: natural toxicity
تعداد نتایج: 594528 فیلتر نتایج به سال:
background: there has been increasing awareness throughout the world regarding the remarkable decrease in amphibian population. for such amphibian population decline several causes have been given. cadmium, a heavy metal is released both from natural sources (leaching of cadmium rich soils) and anthropogenic activities to the aquatic and terrestrial environments. this study evaluated the toxici...
background: this investigation aimed to evaluate the in vitro scolicidal effects of pistacia khinjuk methanolic extract against protoscoleces of hydatid cysts and its acute toxicity in mice nmri model. methods: protoscoleces were aseptically extracted from sheep livers having hydatid cysts. various concentrations of the essential oil (12.5- 100 mg/ml) were used for 10 to 60 min. viability of pr...
The natural pyrethrins from the daisy-like flower, Tanacetum or Chrysanthemum cinerariifolium, are nonpersistent insecticides of low toxicity to mammals. Synthetic analogs or pyrethroids, evolved from the natural compounds by successive isosteric modifications, are more potent and stable and are the newest important class of crop protection chemicals. They retain many of the favorable propertie...
Plantazolicin A, a linear decacyclic natural product, exhibits desirable selective activity against the causative agent of anthrax toxicity. The total synthesis of plantazolicin A and its biosynthetic precursor plantazolicin B was successfully achieved by an efficient, unified, and highly convergent route featuring dicyclizations to form 2,4-concatenated oxazoles and the mild synthesis of thiaz...
Among metal pollutants silver ions are one of the most toxic forms, and have thus been assigned to the highest toxicity class. Its toxicity to a wide range of microorganisms combined with its low toxicity to humans lead to the development of a wealth of silver-based products in many bactericidal applications accounting to more than 1000 nano-technology-based consumer products. Accordingly, silv...
Hydraphile compounds are shown to be cytotoxic to Gram-negative and Gram-positive bacteria, yeast, and mammalian cells. Their cellular toxicity compares favorably with other synthetic ionophores and rivals that potency of natural antibiotics. The effects of structural variations on toxicity are described. The effects of these variations correlate well with previous studies of ion transport in l...
Nanoparticles arise from a wide variety of natural and man-made sources and have a diverse array of biological, chemical, and physical properties. The toxicity of these particles can be roughly divided into two categories: 1) the enhanced delivery of toxic agents 2) toxicity induced the properties of the particle itself. The use of nanoparticles to provide enhanced delivery of chemotherapeutics...
This review discusses the status, antimicrobial mechanisms, application, and regulation of natural preservatives in livestock food systems. Conventional preservatives are synthetic chemical substances including nitrates/nitrites, sulfites, sodium benzoate, propyl gallate, and potassium sorbate. The use of artificial preservatives is being reconsidered because of concerns relating to headache, a...
Natural flavonoids, alkaloids, saponins and sesquiterpenoids have been extensively investigated because of their biological and physiological significances, as well as their promising clinical uses. It is necessary to monitor them or their metabolites in biological fluids for both pre-clinical studies and routine clinical uses. The successful hyphenation of LC and MS, which was thought as "the ...
Natural killer cells gauge the absence of self class I MHC on susceptible target cells by means of inhibitory receptors such as members of the Ly49 family. To initiate killing by natural killer cells, a lack of inhibitory signals must be accompanied by the presence of activating ligands on the target cell. Although natural killer cell-mediated rejection of class I MHC-deficient bone marrow (BM)...
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