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Although no study has confirmed a relationship between the penetration depth of root canal sealers and the prevention of apical periodontitis, dentinal tubule sealer penetration may improve obturation quality.

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Ten acidic and two neutral pharmaceuticals were detected in the effluents of eight sewage treatment plants (STPs) from across Atlantic Canada. Concentrations varied between nondetectable and 35 microg/L. The analgesic, nonsteroidal anti-inflammatory drugs ibuprofen and naproxen were predominant. Carbamazepine, a neutral compound used as an antiepileptic drug, was observed consistently at a median concentration of 79 ng/L. Acetaminophen was found in the effluents of the three largest mechanical STPs at a median concentration of 1.9 microg/L, but not in the lagoon treatment systems. The substantially longer hydraulic retention times may have contributed to more effective removal of acetaminophen in the lagoon treatment systems. Drugs generally were not detected at significant concentrations in the larger bodies of receiving water (Saint John River, Hillsborough River, and Bedford Bay, Canada). However, drug residues in the small receiving streams were 15 to 30% of the effluent median concentrations. Six compounds (caffeine, naproxen, salicylic acid, carbamazepine, metoprolol, and sotolol) were found to persist in a small stream for a distance of at least 17 km, suggesting that small stream exposure to pharmaceutically active residues may be relatively greater than that in large bodies of water. Bioassays assessing acute and chronic effects on four organisms were conducted on four high-use drugs: Acetaminophen, ibuprofen, naproxen, and salicylic acid (metabolite of acetyl salicylic acid). Results indicated no negative effects except for the chronic algal (Selanastrum capricornutum) growth test on ibuprofen (no-observed-effect concentration, 10 microg/L; lowest-observed-effect concentration, 32 microg/L). Effects of these four compounds on invertebrates and plants in the receiving environments are unlikely based on the concentrations measured.

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We report on measurements in transmission of the speckle produced by scattering liquid media: diluted milk and water solutio ns of polystyrene-microspheres of different diameters. The speckle size is affected not only by scattering parameters such as the optical thickness, but also by the dimensions of the scatters. From the speckle measurement, we propose a method to differentiate media. Moreover, a calculation of the transmitted light profile by Monte Carlo simulation allowed us to get a better insight on the speckle size evolution versus scattering.

An experimental Mueller matrix polarimeter is used to quantify human liver fibrosis by measuring retardance and depolarization of thin biopsies. The former parameter is sensitive to fibrillar collagen, the latter is specifically sensitive to fibrillar collagen around blood vessels, which is not significant for liver fibrosis diagnosis. By using depolarization like a filter, retardance distribution enables distinguishing between disease stages and limits the high degree of observer discrepancy.

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