OBJECTIVES The aim of this study was to evaluate the effects of chemical activation of hydrogen peroxide (HP) gel on colour changes and penetration through the tooth structure. METHODS One hundred and four bovine incisors were used. One dentine (CD) disc and one enamel-dentine (ED) disc were prepared from each tooth. They were positioned over artificial pulpal chambers and the bleaching was p...

Introduction: Iron deficiency anemia (IDA) has been shown to cause a false increase in glycosylated hemoglobin (HBA1c), but how much (Hgb) causes certain decrease HBA1c remains unknown. Knowledge of this ratio will enable more accurate clinical diagnosis and follow-up diabetes. This study aimed investigate whether IDA if it does, causes. 
 Material Method: One hundred twenty-two patients w...

The iron balance of 25 adolescent dancers and 23 control females of the same age were studied. The concentrations of fasting blood haemoglobin, serum iron, serum transferrin and serum ferritin were determined. Iron supplementation (ferrous sulphate corresponding to 100 mg of elemental iron per day) was instigated if body iron stores were low (serum ferritin < 30 gg.l-1). Blood samples were draw...

Radiation dosimetry by Fricke gel was largely used, generally focused and optimized for radiotherapy applications therefore involving relative high dose levels. Fricke gel dosimetry has several advantages, like dose rate and LET almost independence, 3D mapping, among other. This work presents a novel Fricke gel dosimeter optimized for low dose levels. Several chemical composition were studied v...

Computer circuit board scrap was first treated with one part concentrated nitric acid and two parts water at 70 degrees C for 1 h. This step dissolved the base metals, thereby liberating the chips from the boards. After solid-liquid separation, the chips, intermixed with some metallic flakes and tin oxide precipitate, were mechanically crushed to liberate the base and precious metals contained ...

Reduction of ferric iron in the presence of HuTu 80 cells or duodenal microvillus membranes (MVMs) was investigated. With both systems, NADH-dependent reduction of Fe3+/NTA (nitrilotriacetic acid) was demonstrated, using the ferrous iron chelator ferrozine. Uptake of Fe3+ from Fe3+/NTA by HuTu 80 cells was strongly inhibited by addition of ferrozine, indicating that Fe2+ is the substrate for th...

Five acidophilic protozoa (three flagellates, one ciliate and one amoeba) were isolated from acid mine water and a coal biotreatment plant, and grown in mixed cultures with acidophilic bacteria. Cultures were routinely maintained in ferrous sulphate media: in media containing pyrite or pyritic coal, protozoa grew in cultures containing coarse-grain (61-200 pm) but not fine-grain (c 61 pm) miner...

Aqueous extract of T. cordifolia inhibited Fenton (FeSO4) reaction and radiation mediated 2-deoxyribose degradation in a dose dependent fashion with an IC50 value of 700 microg/ml for both Fenton and radiation mediated 2-DR degradation. Similarly, it showed a moderate but dose dependent inhibition of chemically generated superoxide anion at 500 microg/ml concentration and above with an IC50 val...