The ionotropic glutamate receptors (iGluRs) represent a major family of ion channels whose quaternary structure has not yet been defined. Here, we present the three-dimensional structure of a fully assembled iGluR, determined at approximately 20A resolution by electron microscopy. Analysis of negatively stained single-particle images reveals the presence of 2-fold, but not 4-fold, symmetry for ...

Flowers can be classified into two basic types according to their symmetry: regular flowers have more than one plane of symmetry and irregular flowers have only a single plane of symmetry. The irregular condition is thought to have evolved many times independently from the regular one: most commonly through the appearance of asymmetry along the dorso-ventral axis of the flower. In most cases, t...

Can autistic people see the forest for the trees? Ongoing uncertainty about the integrity and role of global processing in autism gives special importance to the question of how autistic individuals group local stimulus attributes into meaningful spatial patterns. We investigated visual grouping in autism by measuring sensitivity to mirror symmetry, a highly-salient perceptual image attribute p...

Caesium magnesium orthophosphate is built up from MgO(4) and PO(4) tetra-hedra (both with . m. symmetry) linked together by corners, forming a three-dimensional framework. The Cs atoms have .m. site symmetry and are located in hexa-gonal channels running along the a- and b-axis directions.

Cerium(III) nitride chloride, Ce(2)NCl(3), contains trans-edge connected [NCe(4)](9+) tetra-hedra (222 symmetry) forming chains parallel to the c axis that are separated by Cl(-) anions. The Ce(3+) cations (..m symmetry) are each surrounded by two N(3-) and six Cl(-) anions in a bicapped trigonal prismatic coordination geometry (CN = 8).

The title mol-ecule, C(15)H(15)Br(2), has crystallographic m2m site symmetry. As a result, all atoms, except for those of the methyl groups, are exactly coplanar. In the crystal structure, there are weak π-π inter-actions with a centroid-centroid distance of 3.8409 (15) Å between symmetry-related mol-ecules, which stack along the c axis.

The title compound, C(16)H(21)BO(6), has has approximate C(2) symmetry, but no crystallographically imposed mol-ecular symmetry. In the crystal, mol-ecules are packed into parallel columns along the a axis. Short inter-molecular C-H⋯O contacts stabilize the crystal packing.

In the title compound, C24H27N5O2S·0.5H2O, the piperidine ring adopts a distorted boat conformation. The phenyl rings subtend dihedral angles of 69.7 (1) and 88.7 (1)° with the best plane through the piperidine moiety. In the crystal, symmetry-related mol-ecules are linked through a network of C-H⋯O and C-H⋯N inter-actions, the former connecting them into zigzag chains along the c-axis directio...

Arrays of Ni nanodots embedded in Nb superconducting films have been fabricated by sputtering and electron-beam lithography techniques. The arrays are periodic triangular lattices of circular Ni dots arranged in a kagomélike pattern with broken reflection symmetry. Relevant behaviors are found in the vortex lattice dynamics: i at values lower than the first integer matching field, several fract...

The structure of the title compound, C7H4OS4, at 100 K has ortho-rhom-bic symmetry. In the crystal, tetra-thia-fulvalene mol-ecules form π-stacks along the a axis, with a stacking distance of 3.4736 (6) Å. Along the b axis, parallel stacks are inter-connected with each other through a network of weak C-H⋯O hydrogen bonds and short S⋯S contacts [3.4813 (7) Å]. Additional short S⋯S contacts [3.49...