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Biomedical subjects

D Xenos

Publications and source records attributed to D Xenos.

5 recordsLinked to original sources
PubMed2005

Biological chromium(VI) reduction using a trickling filter.

A pilot-scale trickling filter was constructed and tested for biological chromium(VI) removal from industrial wastewater. Indigenous bacteria from industrial sludge were enriched and used as inoculum for the filter. Sodium acetate was used as carbon source and it was found to inhibit chromate reduction at high concentrations. Three different operating modes were used to investigate the optimal performance and efficiency of the filter, i.e. batch, continuous and SBR with recirculation. The latter one was found to achieve removal rates up to 530 g Cr(VI)/m2 d, while aeration was taking place naturally without the use of any external mechanical means. The low operating cost combined with the high hexavalent chromium reduction rates indicates that this technology may offer a feasible solution to a very serious environmental problem.

Biodegradation, Environmental↗
PubMed2002

Determination of trace elements (Cu, Zn, Mn, Pb) and magnesium by atomical absorption in patients receiving total parenteral nutrition.

OBJECTIVE: We measured the serum levels of four trace elements (Cu, Zn, Mn, Pb) and Mg in surgical patients receiving total parenteral nutrition (TPN). The clinical implications and the results are discussed. METHODS: Two groups of patients were studied: the first group (n = 40) was our study group and the second (n = 40) was the control group. Four measurements of each trace element (TE) in blood serum were carried out: one before initiating TPN, one 24 h after, one 3 d later, and the last one immediately after discontinuing TPN. Each measurement was repeated twice. The Perkin-Elmer atomic absorption spectrophotometer (model 2380) with furnace graphite HGA-300 was used to measure the TE levels and an acetylene flame was used to measure the Mg levels. RESULTS: Levels of all the TEs, except Pb, were lower before the administration of TPN compared with the control group (P < 0.05). The levels of TEs during and immediately after TPN were generally lower in comparison with the initial measurement before the administration of TPN. CONCLUSION: The results of this study suggest that it may be necessary to 1) add Cu, Zn, Mn, and Mg to the parenteral nutritional solution and 2) follow the fluctuations in serum levels during the administration of TPN.

Adolescent↗
PubMed1989

Determination of cerebrospinal fluid and serum lead levels in patients with amyotrophic lateral sclerosis and other neurological diseases.

In a total of 62 samples of cerebrospinal fluid (CSF) and an equal number of serum samples obtained from 16 patients suffering from amyotrophic lateral sclerosis, 22 patients suffering from miscellaneous neurological diseases, and 24 controls, lead was measured by atomic absorption spectrophotometry. No statistical difference in lead concentration was found between the above three groups.

Amyotrophic Lateral Sclerosis↗