A large-sized basal ankylopollexian from East Asia, shedding light on early biogeographic history of Iguanodontia

A presumably mostly quadrupedal ankylopollexian iguanodontian, Bayannurosaurus perfectus gen. et sp.nov., is reported here, and is represented by an excellently well-preserved skeleton from the Lower Cretaceous Bayingebi Formation of Inner Mongolia, China. The diagnosis of the taxon includes several autapomorphies, notably a dorsally directed, strap-like posterodorsal process of the jugal and a horizontally oriented preacetabular process of the ilium. The nearly complete caudal series retains eight posterior-most caudals with procoelous, trapezoidal centra in dorsal view, and the last three caudals are fully fused. The discovery of B. perfectus opens a critical new window on the early evolution and intercontinental dispersal of Iguanodontia. The skeleton displays a transitional morphology between nonhadrosauriform ankylopollexians and Hadrosauriformes. A phylogenetic analysis indicates that Bayannurosaurus is positioned higher on the tree than Hypselospinus, but below Ouranosaurus just outside of Hadrosauriformes. The tree topology of Iguanodontia with temporal and spatial constraints reveals a possible biogeographic scenario supported by the statistical dispersal-vicariance analysis: around the J/K boundary, non-hadrosauriform ankylopollexians experienced multiple dispersal events from Europe to Asia, accompanying the coeval fall of the global sea level.

Efficient and Generic Preparation of Diverse Polyelectrolyte Nanogels by Electrostatic Assembly Directed Polymerization

Nanogels hold promise as soft and functional carriers and nanoreactors,but whether they will ever reach the stage of large-scale application depends crucially on efficient production methods,and on what interesting properties and functionalities they can have.In particular,nanogels consisting of highly charged polyelectrolyte have not yet been very much explored.Here,the authors present a novel and generic strategy for controlled and efficient synthesis of a large diversity of polyelectrolyte nanogels.The method is based on polymerizing an ionic monomer in the presence of an oppositely charged polyion-neutral diblock copolymer as template,while adding a cross-linker.The growing polymer chains assemble with the template,forming polyion complex micelles,which dissociate upon increasing salt concentration.Subsequent separation yields nanogels with well-controlled size and properties,and free template polymers that can be used again.Our design can be applied generally to a wide range of both cationic and anionic monomers,as well as various cross-linkers.Scaled-up production presents no problems as increasing monomer concentration(hundreds of mM)and reaction volume(up to 1 L)hardly compromise product quality.Moreover,the obtained nanogels with their well-controlled size,morphology,chemistry,and cross-linking degree perform well as soft nanocarriers and catalytic nanoreactors.

Ternary supramolecular quantum-dot network flocculation for selective lectin detection

We present a versatile, tuneable, and selective nanoparficle-based lectin biosensor, based on flocculation of ternary supramolecular nanoparticle networks （NPN）, formed through the sequential binding of three building blocks. The three building blocks are ^-cyclodextrin-capped CdTe quantum dots, tetraethylene glycol-tethered mannose-adamantane cross-linkers （ADTEGMan）, and the tetravalent lectin Concanavalin A （ConA）. The working principle of this selective sensor lies in the dual orthogonal molecular interactions of the linker, uniting adamantane-^-cyclodextrin and mannose-lectin interaction motifs, respectively. Only when the lectin is present, sequential binding takes place, leading to in situ self-organization of the sensor through the formation of ternary supramolecular networks. Monitoring the loss of fluorescence signal of the quantum dots in solution, caused by controlled network formation and consecutive flocculation and sedimentation, leads to selective, qualitative, and quantitative lectin detection. Fluorescent sedimented networks can be observed by the naked eye or under UV illumination for a lectin concentration of up to 10 8 M. Quantitative detection is possible at 100 min with a lower detection limit of approximately 5 × 10 ^-8 M.