Comparative ultrastructural investigations of the podocyte in marine bivalve Pinctada radiata (Pteriidae) and freshwater bivalve Anodonta rubens (Unionidae)

Ultrastructure of the podocyte of the pericardia! gland in marine bivalve Pinctada radiata and in fresh water bivalve Anodonta rubens were investigated. Obvious differences in shape, distribution and number of cytoplasmic organelles of the podocytes observed in both species are suggested to be related to the difference of their habitats. In addition, the pedicels of the basal membrane are more complex in A. rubens than those in P. radiata, and also the surface of the apical cell differs in structure. The suitability of podocyte structure to its function is discussed

Second Dome of Superconductivity in YBa2_2Cu3_3O7_7 at High Pressure

Evidence is growing that a second dome of high-$T_\mathrm{c}$ superconductivity can be accessed in the cuprates by increasing the doping beyond the first dome. Here we use \emph{ab initio} methods without invoking any free parameters such as the Hubbard $U$, to reveal that pressure could turn YBa$_2$Cu$_3$O$_7$ into an ideal candidate for second-dome-superconductivity, displaying the predicted signature of strongly hybridized $d_{x^2-y^2}$ and $d_{z^2}$ orbitals. Notably, pressure is found to induce a phase transition replacing the antiferromagnetic phases with an orbitally-degenerate $d$-$d$ phase. We find an interesting doping-dependence of the oxygen-hole fraction in the CuO$_2$ planes, which suggests the presence of a second dome