Superoxide dismutases (SODs) disproportionate 2O·− 2 + 2H+ → H2O2 + O2, thus helping to forestall aging and protect aerobic organisms against the byproducts of respiration (reviewed in Miller and Sorkin, 1997). FeSOD is a dimer of identical 21 kDa monomers, each containing a single high-spin non-heme non-sulfur Fe in the active site. This Fe alternates between the Fe3+ and Fe2+ states in the ac...

The most common beneficiation method for feldspar is flotation with a cationic (amine) collector under acidic conditions. However, there are several disadvantages to this, such as environmental pollution and equipment corrosion. In order resolve problems, it important study the of using anionic collectors natural pH purpose this paper effects mechanism Fe3+ on separation epidote sodium oleate (...

A new type of sulfite oxidase which utilizes ferric ion (Fe3+) as an electron acceptor was found in iron-grown Thiobacillus ferrooxidans. It was localized in the plasma membrane of the bacterium and had a pH optimum at 6.0. Under aerobic conditions, 1 mol of sulfite was oxidized by the enzyme to produce 1 mol of sulfate. Under anaerobic conditions in the presence of Fe3+, sulfite was oxidized b...

Pathologic calcification leads to structural deterioration of implant materials via stiffening, stress cracking, and other structural disintegration mechanisms, and the effect can be critical for implants intended for long-term or permanent implantation. This study demonstrates the potential of using specific metal ions (MI)s for inhibiting pathological calcification in polyurethane (PU) implan...

In the presence of NADH- reductases (dihydrolipoamide: NAD oxidoreductase E. C.1.8.1.4 from pig heart or from Clostridium kluyveri; frequently also addressed as "diaphorases") and NADH lucigenin strongly increases ethylene production from a-keto-methylthiobutyrate (KMB) as an indicator for strong oxidants of the OH-radical type. These reactions are further stimulated in the presence of Fe3+ ion...

Adriamycin is an anthracycline antineoplastic agent whose clinical effectiveness is limited by severe side effects, including cardiotoxicity. A current hypothesis for adriamycin cardiotoxicity involves free radical oxidative stress. To investigate this hypothesis in a model system, we applied the technique of immunochemical detection of protein carbonyls, known to be increased in oxidized prote...

Iron accumulation, oxidative stress and calcium signaling dysregulation are common pathognomonic signs of several neurodegenerative diseases, including Parkinson´s and Alzheimer's diseases, Friedreich ataxia and Huntington's disease. Given their therapeutic potential, the identification of multifunctional compounds that suppress these damaging features is highly desirable. Here, we report the s...

In this work, the effect of cultivation factors on the flocculation efficiency (FE) of bioflocculant P-GS408 from Klebsiella oxytoca was optimized by the response surface methodology. The most significant factor, i.e. culture time, was determined by gray relational analysis. A total of 240 mg of purified P-GS408 was prepared from 1 liter of culture solution under the optimal conditions. GC-MS a...

O estudo de [Fe(CO)5], [Fe2(CO)9] e [Fe3(CO)12] como precursores catalíticos nas reações de hidrogenação do ciclohexeno e 1-hexeno foi efetuado. Um reator fotoquímico com fluxo de H2 e irradiação UV-vis foi usado no processo. Os espectros infravermelho das amostras mostraram a formação de [Fe(CO)4(olefina)] e [HFe(CO)3(π-alila)] como intermediários. A atividade mostrada do [Fe2(CO)9] na hidroge...