Effect of HCl on a sorption of mercury from flue gas evolved during incineration of hospital waste using entrained flow adsorbers.

Small incinerators of dangerous wastes, including those from hospitals, are a source of emissions of highly variable compositions and concentrations. Mercury is a very dangerous pollutant causing neurotoxicity in human organism. The effect of HCl concentration on adsorption of mercury on activated carbon-based sorbent was studied for the incineration of hospital waste in a 250 kg/h capacity unit. The maximum concentration of adsorbed mercury on activated carbon was determined as a function of concentration of Hg and HCl in combustion products. Based on the expected chemical reactions and the thermodynamics, the adsorption of mercury from flue gases in oxidising atmosphere has been explained. The activated carbon-based sorbent was also capable of adsorbing acid gases like HCl. The efficiency of removal of mercury from combustion products increased up to 85-87% with the concentration of HCl in flue gases. The addition of calcium hydroxide increased the amount of mercury trapped on the sorbent only by about 10%. These tests proved that an entrained flow adsorber is a suitable unit for the removal of mercury from combustion products. The consumption of activated carbon for the mercury removal was from 0.1 to 0.15 mg/Nm3 of flue gas. The advantage of an entrained flow adsorber lies in its easy continuous operation. Therefore, it is a suitable unit for small and medium size incinerators of municipal and hospital waste.

Meckel's Diverticulum in Children-Parameters Predicting the Presence of Gastric Heterotopia.

BACKGROUND: The presence of gastric ectopic mucosa in Meckel's diverticulum is associated with a higher risk of development of complications. The aim of the present study was to investigate which demographic/clinical parameters predict the presence of gastric heterotopia in Meckel's diverticulum. METHODS: This was a retrospective cohort study conducted in a single institution (University Hospital Ostrava, Czech republic). All children who underwent laparoscopic/open resection of Meckel's diverticulum within a 20-year study period were included in the study. RESULTS: In total, 88 pediatric patients underwent analysis. The mean age of the children was 4.6 ± 4.73 years; the male-female ratio was approximately 2:1. There were 50 (56.8%) patients with asymptomatic Meckel's diverticulum in our study group. Laparoscopic resection was performed in 24 (27.3%) patients; segmental bowel resection through laparotomy was performed in 13 (14.8%) patients. Gastric heterotopia was found in 39 (44.3%) patients; resection margins of all patients were clear of gastric heterotopia. No correlation was found between the presence of gastric heterotopia and the following parameters: age, gender, maternal age, prematurity, low birth weight, perinatal asphyxia, distance from Bauhin's valve and length of Meckel's diverticulum. The width of the diverticulum base was significantly higher in patients with gastric heterotopia (2.1 ± 0.57 vs. 1.2 ± 0.41 cm; p < 0.001). CONCLUSIONS: According to the study outcomes, the width of the diverticulum base seems to be a significant predictive factor associated with the presence of gastric heterotopia in Meckel's diverticulum. The laparoscopic/open resection of asymptomatic MD with a wide base should therefore be recommended.

DEAD-box RNA helicase is dispensable for mitochondrial translation in Trypanosoma brucei.

DEAD-box RNA helicase, a putative subunit of the mitochondrial ribosome of Trypanosoma brucei, has been down-regulated in the procyclic and bloodstream stage by RNA interference. Although ablation of the transcript leads to a week growth phenotype in the procyclic cells, the protein does not seem to be essential for mitochondrial translation under standard cultivation conditions, as shown by an assay that allows visualization of the de novo synthesized proteins. Furthermore, we show that synthesis of cytochrome c oxidase subunit I and cytochrome b does not occur in the mitochondrion of the bloodstream stage.

Probing for primary functions of prohibitin in Trypanosoma brucei.

Prohibitins (PHBs) 1 and 2 are small conserved proteins implicated in a number of functions in the mitochondrion, as well as in the nucleus of eukaryotic cells. The current understanding of PHB functions comes from studies of model organisms such as yeast, worm and mouse, but considerable debate remains with regard to the primary functions of these ubiquitous proteins. We exploit the tractable reverse genetics of Trypanosoma brucei, the causative agent of African sleeping sickness, in order to specifically analyse the function of PHB in this highly divergent eukaryote. Using inducible RNA interference (RNAi) we show that PHB1 is essential in T. brucei, where it is confined to the cell's single mitochondrion forming a high molecular weight complex. PHB1 and PHB2 appear to be indispensible for mitochondrial translation. Their ablation leads to a decrease in mitochondrial membrane potential, however no effect on the level of reactive oxygen species was observed. Flagellates lacking either PHB1 or both PHB1 and PHB2 exhibit significant morphological changes of their organelle, most notably its inflation. Even long after the loss of the PHB proteins, mtDNA was unaltered and mitochondrial cristae remained present, albeit displaced to the periphery of the mitochondrion, which is in contrast to other eukaryotes.

The import and function of diatom and plant frataxins in the mitochondrion of Trypanosoma brucei.

Frataxin is a conserved mitochondrial protein, almost universally present in prokaryotes and eukaryotes, where it is implicated in Fe-S cluster assembly and several other processes. Here we show that frataxins from the diatom Thalassiosira pseudonana and the plant Arabidopsis thaliana are efficiently targeted and processed in the mitochondrion of the evolutionary distant excavate kinetoplastid flagellate Trypanosoma brucei. Moreover, both heterologous frataxins are able to rescue a lethal deficiency for T. brucei frataxin.