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Lying Parallel (lying + parallel)
Selected AbstractsAFM study of crystalline cellulose in the cell walls of strawPOLYMER INTERNATIONAL, Issue 1 2006Wan Li Abstract Crystalline cellulose in the cell walls of straw was studied by atomic force microscopy (AFM). The samples were first treated and then observed by AFM under dimethylsulfoxide (DMSO). The crystalline regions were located and two allomorphs of crystalline cellulose, triclinic I, and monoclinic I, phases, were identified. In most crystalline regions, the I, and I, phases are intimately associated, with the I, phase more abundant than the I, phase. In some small domains only one phase with long-range order was observed. It was demonstrated that in these one-phase domains, I, phase crystals always have their (010) plane lying parallel to the cell wall surface and I, phase crystals with (110) plane lying parallel. Copyright © 2005 Society of Chemical Industry [source] Poly[deca-,2 -cyanido-dicyanidobis(,2 -ethylenediamine)bis(ethylenediamine)tricadmium(II)dicobalt(III)]: a two-dimensional coordination polymerACTA CRYSTALLOGRAPHICA SECTION C, Issue 3 2009Olha Sereda The title coordination polymer, [Cd3Co2(CN)12(C2H8N2)4]n, has an infinite two-dimensional network structure. The asymmetric unit is composed of two crystallographically independent CdII atoms, one of which is located on a twofold rotation axis. There are two independent ethylenediamine (en) ligands, one of which bis-chelates to the Cd atom that sits in a general position, while the other bridges this Cd atom to that sitting on the twofold axis. The Cd atom located on the twofold rotation axis is linked to four equivalent CoIII atoms via cyanide bridges, while the Cd atom that sits in a general position is connected to three equivalent CoIII atoms via cyanide bridges. In this way, a series of trinuclear, tetranuclear and pentanuclear macrocycles are linked to form a two-dimensional network structure lying parallel to the bc plane. In the crystal structure, these two-dimensional networks are linked via N,H...N hydrogen bonds involving an en NH2 H atom and a cyanide N atom, leading to the formation of a three-dimensional structure. This coordination polymer is only the second example involving a cyanometallate where the en ligand is present in both chelating and bridging coordination modes. [source] A novel three-dimensional coordination polymer: poly[di-,3 -acetato-di-,2 -acetato-di-,3 -hydroxido-octa-,3 -triazolato-heptamanganese(II)]ACTA CRYSTALLOGRAPHICA SECTION C, Issue 1 2008Zhe-Hui Weng The title compound, [Mn7(C2H2N3)8(C2H3O2)4(OH)2]n, is composed of centrosymmetric heptanuclear building units with the central Mn atom on an inversion center. In the building block, three MnII ions are held together by one ,3 -hydroxide group, two ,2 -triazolate (trz) ligands and two ,2 -acetate groups, forming an Mn3 cluster. Two Mn3 clusters are bridged by an Mn atom via two ,2 -trz ligands and two ,2 -O atoms from two acetate ions to construct a heptanuclear building block. The heptanuclear building units, lying parallel to each other along the b direction, form one-dimensional ladder-like chains and are further interlinked, resulting in a three-dimensional framework through Mn,Ntrz bonds. [source] Dissecting membrane protein architecture: An annotation of structural complexityBIOPOLYMERS, Issue 10 2009Jaime Arce Abstract ,-Helical membrane proteins exist in an anisotropic environment which strongly influences their folding, stability, and architecture, which is far more complex than a simple bundle of transmembrane helices, notably due to helix deformations, prosthetic groups and extramembrane structures. However, the role and the distribution of such heterogeneity in the supra molecular organization of membrane proteins remains poorly investigated. Using a nonredundant subset of ,-helical membrane proteins, we have annotated and analyze the statistics of several types of new elements such as incomplete helices, intramembrane loops, helical extensions of helical transmembrane domains, extracellular loops, and helices lying parallel to the membrane surface. The relevance of the annotation scheme was studied using residue composition, statistics, physical chemistry, and symmetry of their distribution in relation to the immediate membrane environment. Calculation of hydrophobicity using different scales show that different structural elements appear to have affinities coherent with their position in the membrane. Examination of the annotation scheme suggests that there is considerable information content in the amino acid compositions of the different elements suggesting that it might be useful for structural prediction. More importantly, the proposed annotation will help to decipher the complex hierarchy of interactions involved in membrane protein architecture. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 815,829, 2009. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] | ||||||||||