Cytochemical Responses in the Digestive Tissue of Mytilus edulis Complex Exposed to Microencapsulated PAHs or PCBs

Cytochemical responses in the digestive tissue of Mytilus edulis complex fed a microencapsulated mixture of PAHs (composed of phenanthrene, fluoranthene and benzo[a]pyrene) or PCBs (Aroclor 1254) were evaluated. Lysosomal membrane labilization period and lipofuscin content of digestive tissue were significantly decreased and increased, respectively, after 30 days of exposure to PAHs but not PCBs. NADPH-ferrihemoprotein reductase activity in the digestive tissue was significantly increased after 30 days exposure to both PAHs and PCBs, whereas catalase activity was significantly increased only after exposure to PCBs. Neutral lipid content and gamma-glutamyl transpeptidase activity of digestive tissue of mussels were significantly increased and decreased, respectively, after 30 days exposure to both PAHs and PCBs when compared to untreated mussels, but were not significantly different when compared to mussels treated with com oil representing the vehicle control. Exposure to PAHs induced peroxisome proliferation in the digestive tissue of M. edulis complex. The observed cytochemical responses in the digestive tissue of M. edulis complex exposed to PAHs and PCBs in the laboratory are comparable to the cytochemical responses observed in the digestive tissue of mussels collected in the field from sites contaminated with predominantly PAHs and PCBs

Experiments on the Low Frequency Barrier Characteristics of Cellular Metamaterial Panels in a Diffuse Sound Field

The metamaterial under investigation here consists of a periodic arrangement of unit plates in a grid-like frame such that there is a contrast in the local areal mass between cell interior and cell wall. In the low frequency range and under normal incidence this metamaterial panel exhibits a sound transmission loss significantly larger than the transmission loss of an unstructured panel with the same homogeneous mass per unit area. However, when the incident sound field is diffuse, the relative advantage of the metamaterial barrier is reduced or eliminated. A sequence of experiments is documented to demonstrate that the relative advantage of the metamaterial barrier can be realized even in a diffuse sound field by creating a hybrid barrier system which embeds the metamaterial layer between a normalizing waveguide layer on the incident side and an absorbing layer on the transmitted side. The sound normalizing waveguide layer is a lattice structure, and the absorbing layer is high performance glass fiber mat. By using measurements of the transmission loss of a 1,2 m square panel system the role of each of these components is demonstrated

Enhanced self-field critical current density of nano-composite YBa(2)Cu(3)O(7) thin films grown by pulsed-laser deposition

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ EPLA, 2008.Enhanced self-field critical current density Jc of novel, high-temperature superconducting thin films is reported. Layers are deposited on (001) MgO substrates by laser ablation of YBa2Cu3O7−δ(Y-123) ceramics containing Y2Ba4CuMOx (M-2411, M=Ag, Nb, Ru, Zr) nano-particles. The Jc of films depends on the secondary-phase content of the ceramic targets, which was varied between 0 and 15 mol%. Composite layers (2 mol% of Ag-2411 and Nb-2411) exhibit Jc values at 77 K of up to 5.1 MA/cm2, which is 3 to 4 times higher than those observed in films deposited from phase pure Y-123 ceramics. Nb-2411 grows epitaxially in the composite layers and the estimated crystallite size is ~10 nm.The Austrian Science Fund, the Austrian Federal Ministry of Economics and Labour, the European Science Foundation and the Higher Education Commission of Pakistan

Effects of chemical contaminants on the health of Mytilus edulis from Puget Sound, Washington. II. Cytochemical detection of subcellular changes in digestive cells

Activities of the enzymes NADPH-dependent ferrihemoprotein reductase (NFR), NADH-dependent DT -diaphorase (DTD), gamma-glut amyl transpeptidase (GGT), and catalase (CAT) and peroxisome proliferation (PP) in the digestive cells of Myliills edulis from nine sites in Puget Sound, Washington (USA) sampled in September 1992 were measured cytochemically using image analysis

Magnetization creep and decay in YBa2Cu3O7−x thin films with artificial nanostructure pinning

Critical current and flux pinning have been studied for YBa_2Cu_3O_7−x thin films with Y_2BaCuO_5 (211) precipitates introduced as layers and as random distributions. The 211 precipitates were introduced during pulsed laser deposition. In the case of the layered sample, the strata were spaced approximately 6.5 nm apart throughout the film thickness. Magnetically determined critical current density (J_c) was then fitted to J_c∝B^−α above a magnetic field B*, below which a relatively field independent J_c-self-field was observed, consistent with previous results. Values of α were suppressed from the control sample values of α=0.5 to lower values for pinned samples, reaching α=0.2 for the layer pinned 211 sample at low temperatures. M-H was then measured as a function of ramp rate, and U(J) vs J curves were extracted for temperatures from 4.2 to 77 K for pinned and control samples. Direct magnetization decay measurements were made for the 211 layer pinned sample, and good agreement was seen with ramp-rate-derived results. Using U(J)=(U_0∕μ)[(J_c∕J)^μ−1]B^−ν, values of μ≅0.6–0.8 were seen for all samples, while ν≅0.4 for control samples, 0.1 for layer pinned samples, and 0.2–0.4 for the random pinned samples. The activation energy scale U_0 was 600–700 and 400 K for layer pinned and control samples, respectively, and 400–500 K for the random pinned samples. The values of μ and ν extracted were inconsistent with two dimensional pinning behavior in all cases, even though the layer spacing in the layer pinned sample is smaller than the calculated collective correlation length. While the layer pinned sample is clearly in the collective pinning regime, the artificial defects in the random pinned sample may be in the isolated strong pinning regime

Lack of Association of Bone Morphogenetic Protein 2 Gene Haplotypes with Bone Mineral Density, Bone Loss, or Risk of Fractures in Men

Introduction. The association of bone morphogenetic protein 2 (BMP2) with BMD and risk of fracture was suggested by a recent linkage study, but subsequent studies have been contradictory. We report the results of a study of the relationship between BMP2 genotypes and BMD, annual change in BMD, and risk of fracture in male subjects. Materials and Methods. We tested three single-nucleotide polymorphisms (SNPs) across the BMP2 gene, including Ser37Ala SNP, in 342 Caucasian Englishmen, comprising 224 control and 118 osteoporotic subjects. Results. BMP2 SNP1 (Ser37Ala) genotypes were found to have similar low frequency in control subjects and men with osteoporosis. The major informative polymorphism, BMP2 SNP3 (Arg190Ser), showed no statistically significant association with weight, height, BMD, change in BMD at hip or lumbar spine, and risk of fracture. Conclusion. There were no genotypic or haplotypic effects of the BMP2 candidate gene on BMD, change in BMD, or fracture risk identified in this cohort