An illustrated anatomical ontology of the developing mouse lower urogenital tract

Malformation of the urogenital tract represents a considerable paediatric burden, with many defects affecting the lower urinary tract (LUT), genital tubercle and associated structures. Understanding the molecular basis of such defects frequently draws on murine models. However, human anatomical terms do not always superimpose on the mouse, and the lack of accurate and standardised nomenclature is hampering the utility of such animal models. We previously developed an anatomical ontology for the murine urogenital system. Here, we present a comprehensive update of this ontology pertaining to mouse LUT, genital tubercle and associated reproductive structures (E10.5 to adult). Ontology changes were based on recently published insights into the cellular and gross anatomy of these structures, and on new analyses of epithelial cell types present in the pelvic urethra and regions of the bladder. Ontology changes include new structures, tissue layers and cell types within the LUT, external genitalia and lower reproductive structures. Representative illustrations, detailed text descriptions and molecular markers that selectively label muscle, nerves/ganglia and epithelia of the lower urogenital system are also presented. The revised ontology will be an important tool for researchers studying urogenital development/malformation in mouse models and will improve our capacity to appropriately interpret these with respect to the human situation

Direct one-pot synthesis of L1 0 –FePtAg nanoparticles with uniform and very small particle sizes

International audienc

Core/shell Cu/FePtCu nanoparticles with face-centered tetragonal texture: An active and stable low-Pt catalyst for enhanced oxygen reduction

International audienceLow-Pt based nanocrystals demonstrate potential as highly active catalysts for the oxygen reduction reaction (ORR), but they suffer from undesirable structural degradation. Therefore, it is highly challenging to optimize their surface and interfacial structures to tune their catalytic properties for both activity and stability. Here core–shell Cu/FePtCu nanoparticles with a face-centered-tetragonal phase are prepared by a facile one–pot polyol method at 320 °C. The optimized core–shell Fe45Pt35Cu20 catalyst with Pt-enriched surface exhibits 0.5 A/mgPt mass activity, which is a factor of 4 better than that of commercial Pt/C (0.13 A/mgPt). In addition, the current density of the catalyst drops only 3.0% after 1000 cycles, which is much better than Pt/C (34.2% decay). Using aberration-corrected scanning transmission electron microscopy and atomically resolved elemental mapping, the morphology and structure evolving between the FePtCu alloy and core–shell Cu/FePtCu could clearly be explained. This work demonstrates that an ordered and core–shell FePtCu catalyst is highly promising for ORR and other electrochemical processes

Effect of Cu doping on the structure and phase transition of directly synthesized FePt nanoparticles

International audienceIn this work, ternary Cu doped FePt nanoparticles were prepared in hexadecylamine at 320 °C by choosing FeCl2 as the Fe source. The experimental results showed that without Cu doping the as-prepared FePt nanoparticles possessed fcc structure and gradually exhibited typical fct diffraction peaks after increasing the Cu doping concentration. TEM images showed that the FePt nanoparticles had larger size and wider size distribution after introducing Cu additive. Magnetic property measurement showed that a coercivity of 4800 Oe was obtained when the composition of the ternary nanoparticles reached Fe35Pt45Cu20, in which the content of Fe+Cu was higher than Pt. The research indicates that Cu doping promotes the phase transition of FePt nanoparticles at temperature as low as 320 °C

Polyploid Superficial Cells that Maintain the Urothelial Barrier Are Produced via Incomplete Cytokinesis and Endoreplication

Summary: The urothelium is an epithelia barrier lined by a luminal layer of binucleated, octoploid, superficial cells. Superficial cells are critical for production and transport of uroplakins, a family of proteins that assemble into a waterproof crystalline plaque that helps protect against infection and toxic substances. Adult urothelium is nearly quiescent, but rapidly regenerates in response to injury. Yet the mechanism by which binucleated, polyploid, superficial cells are produced remains unclear. Here, we show that superficial cells are likely to be derived from a population of binucleated intermediate cells, which are produced from mononucleated intermediate cells via incomplete cytokinesis. We show that binucleated intermediate and superficial cells increase DNA content via endoreplication, passing through S phase without entering mitosis. The urothelium can be permanently damaged by repetitive or chronic injury or disease. Identification of the mechanism by which superficial cells are produced may be important for developing strategies for urothelial repair. : Binucleated superficial cells are critical for urothelial barrier function. Wang et al. show that they derive from binucleated intermediate cells that form via incomplete cytokinesis. Both superficial and intermediate cells increase ploidy via endoreplication, a feature likely to be important for repair and response to environmental changes. Keywords: endoreplication, urothelium, polyploidy, epithelial barrier, regeneratio

Retinoid Signaling in Progenitors Controls Specification and Regeneration of the Urothelium

The urothelium is a multilayered epithelium that serves as a barrier between the urinary tract and blood, preventing the exchange of water and toxic substances. It consists of superficial cells specialized for synthesis and transport of uroplakins that assemble into a tough apical plaque, one or more layers of intermediate cells, and keratin 5-expressing basal cells (K5-BCs), which are considered to be progenitors in the urothelium and other specialized epithelia. Fate mapping, however, reveals that intermediate cells rather than K5-BCs are progenitors in the adult regenerating urothelium, that P cells, a transient population, are progenitors in the embryo, and that retinoids are critical in P cells and intermediate cells, respectively, for their specification during development and regeneration. These observations have important implications for tissue engineering and repair and, ultimately, may lead to treatments that prevent loss of the urothelial barrier, a major cause of voiding dysfunction and bladder pain syndrome