Laccase Biosensors Based on Mercury Thin Film Electrode An k K rgöz, Ülkü; Tural, Hüseyin; Timur, Suna ...
Artificial cells, blood substitutes, and immobilization biotechnology,
2005, Letnik:
33, Številka:
4
Journal Article
Odprti dostop
A biosensor was developed by immobilizing laccase onto mercury thin film electrode (MTFE) by means of gelatin that is then crosslinked with glutaraldehyde. Mercury thin film (MTF) was deposited onto ...glassy carbon electrode (GCE) and the obtained biosensor was utilized for the determination of phenolic compounds. The measurement was based on the amperometric detection of oxygen consumption in relation to analyte oxidation. The optimum experimental conditions for the biosensor were investigated and the system was calibrated for both catechol and phenol. A linear relationship between sensor responses and analyte concentrations was obtained in concentration range between 0.5 × 10−6- 5.0 × 10−6 M for catechol and 2.5 × 10−6- 2.0 × 10−6 M for phenol, respectively. Mercury thin film was also formed onto the surface of screen printed graphite electrodes and applied for the catechol detection. The linearity was observed in concentration range between 2.5 × 10−6- 3.0 × 10−5 M.
Ninetysix untreated patients with Malignant lymphoma's, 81 Hodgkin's disease and 15 Burkitt's lymphoma were studied for zinc (Zn) and selenium (Se) status. Plasma and hair Zn, and Se levels were ...measured by atomic absorption spectrophotometry. Chronic Zn and Se deficiencies (low plasma and low hair Zn and Se levels together) were found to be associated with Malignant lymphoma's in Turkish children. This was most likely due to poor "nutritional environment" of the patients since majority of the Malignant lymphoma cases were from low socioeconomic class. Supplemention of the patients with physiological doses of Zn and Se, in addition to standard chemo radiotherapy regimen was proposed.
Endothelins (ET) are the most important vasoconstrictors known, and administration results in contraction of vascular strips in man and experimental animals in vitro. We examined the effects of ET-1 ...on thrombus formation in rabbits. We used vasoconstrictor and thrombus forming agents and we selected an animal model, the vena jugularis thrombus model. In addition, intravascular endothelium was examined ultrastructurally. The ET-1 level is known to be high in patients with hypertension; if these patients also have atherosclerosis, then intravascular thrombus formation may increase. In the vena jugularis thrombus model, thromboplastin and ET-1 act synergistically to increase intravascular thrombus formation. On injection of ET-1 dose dependent vasoconstriction was shown in the vessel wall. Although similar maximal contraction is achieved, a decrease in vessel diameter is associated with increased potency of ET-1 and thromboplastin. The results suggest that ET-1 may regulate vascular tone through constriction of vessels.
In systemic lupus erythematosus (SLE), the central nervous system (CNS) produces numerous and varying clinical disorders. A 14-year-old girl with the features of cerebral involvement in SLE is ...presented. The development of diabetes insipidus (DI), which responded to desmopressin, was an interesting finding in this case. Therapy consisting of high-dose methylprednisolone combined with cyclophosphamide was effective in improving the symptoms as well as the DI.
Lichen samples collected before and after the Chernobyl accident were analysed for radiocesium activity. 137Cs activity was detected in some samples collected before Chernobyl. 134Cs and 137Cs were ...detected in all the samples after the accident. The levels of the total cesium activity counted in the samples proved that the eastern region of the Black Sea was affected by Chernobyl at a very high degree compared with other arts of Turkey.
