Alteration of acute toxicity of inorganic and methyl mercury to Daphnia magna by dietary addition

Acute toxicity of inorganic mercury [Hg(II)] and methylmercury (MeHg) to Daphnia magna was characterized using a 48-h static, non-renewal acute toxicity test, in which we compared the toxicity of Hg(II) and MeHg in the absence (water-only) and presence of diet [green alga (Raphidocelis subcapitata), yeast, Cerophyll, and trout chow (YCT), or both]. Overall, Hg(II) is more toxic to D. magna than MeHg, with 48-h median lethal concentrations (LC50s) being 4.3 µg/L (95% confidence interval: 4.1–4.5 µg/L) for Hg(II) and 14.3 µg/L (13.2–15.3 µg/L) for MeHg. For Hg(II), the addition of any diet would significantly increase its 48-h LC50, but the 48-h LC50 for MeHg decreased significantly to 7.1 µg/L (6.4–7.8 µg/L) with the algal addition. We also show that the addition of diets significantly influenced the levels and speciation (dissolved vs. particulate) of both Hg forms in the test solution. The bioaccumulation of Hg(II) and MeHg was impacted by the dietary addition, and it appears that the body residue level triggering mortality varied widely among treatments. The results suggest that standard short-term toxicity tests (water-only) should be supplemented with extra tests with dietary addition to provide a more environmentally relevant estimation of short-term toxicity of chemical compounds.

Potential of Green Ceramics Waste for Alkali Activated Foams

The aim of the paper is to research the influence of foaming and stabilization agents in the alkali activation process of waste green ceramics for future low cost up-cycling into lightweight porous thermal insulating material. Green waste ceramics, which is used in the present article, is a green body residue (non-successful intermediate-product) in the synthesis of technical ceramics for fuses. This residue was alkali activated with Na-water glass and NaOH in theoretically determined ratio based on data from X-ray fluorescence (XRF) and X-ray powder diffraction (XRD) that was set to maximise mechanical properties and to avoid efflorescence. Prepared mixtures were compared to alkali activated material prepared in theoretically less favourable ratios, and tested on the strength and density. Selected mixtures were further foamed with different foaming agents, that are Na-perborate (s), H2O2 (l), and Al (s), and supported by a stabilization agent, i.e., Na-dodecyl sulphate. The goal of the presented work was to prepare alkali activated foam based on green ceramics with density below 1 kg/l and compressive strength above 1 MPa.

Surgical removal of a foreign body in the pulmonary artery

Foreign bodies, such as a fragmented catheter or metallic objects from industrial accidents, that have accidentally entered a major cardiac vessel or pulmonary artery have been successfully removed non-surgically via intravenous catheterization. We report the rare case of a cracked iron hammer fragment that had entered the femoral vein and migrated to the pulmonary artery through major blood vessels without causing hemorrhage, which eventually required surgical removal. A 19-year-old man accidentally smashed an iron hammer that broke into small pieces, one of which entered his femoral vein and eventually lodged in the pulmonary artery. After non-surgical intravenous catheterization to remove this foreign body was unsuccessful, it was removed surgically under video-assisted thoracoscopy. Foreign body residue over the long term can cause hemorrhage, pulmonary infarction, infection, and/or abscess. Transvenous recovery is the primary non-surgical means of removing a foreign body from the pulmonary artery. It is less harmful than surgical removal and causes fewer complications. Nevertheless, it is essential to be ready to execute a surgical approach for foreign body removal when other interventions have failed.

Re-analysis of narcotic critical body residue data using the equilibrium distribution concept and refined partition coefficients

An internal distribution model with relevant partition coefficients can reduce the variability of narcotic critical body residues.