다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

J. Appl. Cryst.の発刊に際して

Foldamers are sequence-specific oligomers akin to peptides, proteins and oligonucleotides that fold into well-defined three-dimensional structures They offer the chemical biologist a broad pallet of building blocks for the construction of molecules that test and extend our understanding of protein folding and function Foldamers also provide templates for presenting complex arrays of functional groups in virtually unlimited geometrical patterns, thereby presenting attractive opportunities for the design of molecules that bind in a sequence- and structure-specific manner to oligosaccharides, nucleic acids, membranes and proteins We summarize recent advances and highlight the future applications and challenges of this rapidly expanding field

/pdf/foldamers-as-versatile-frameworks-for-the-design-and-3c7l3qq4hq.pdf

Foldamers as versatile frameworks for the design and evolution of function

International Tables for X-Ray Crystallography (Published for the International Union of Crystallography.) Vol. 1: Symmetry Groups. Edited by Norman F. M. Henry and Kathleen Lonsdale. Pp. xi + 558. (Birmingham: Kynoch Press, 1952.) 105s.

/pdf/international-tables-for-x-ray-crystallography-1t8sk98xrd.pdf

International Tables for X-Ray Crystallography

We report the evaluation of the thermoelectric performance of polycrystalline p-type SnSe, a material in which unprecedented values of the thermoelectric figure of merit ZT have been recently discovered in single crystals Besides anisotropic transport properties, our results confirm that this compound exhibits intrinsically very low thermal conductivity values The electrical properties show trends typical of lightly doped, intrinsic semiconductors with thermopower values reaching 500 μV K−1 in a broad temperature range An orthorhombic-to-orthorhombic transition sets in at 823 K, a temperature at which the power factor reaches its maximum value A maximum ZT of 05 was obtained at 823 K, suggesting that proper optimization of the transport properties of SnSe might lead to higher ZT values These findings indicate that this system represents an interesting experimental platform for the search of highly efficient thermoelectric materials

Assessment of the thermoelectric performance of polycrystalline p-type SnSe

Solution Synthesis and Characterization of Aza-β3-peptides (Nα-Substituted Hydrazino Acetic Acid Oligomers)

Crystals of aza-β3-peptides have been obtained. This gives the first opportunity for hydrazino peptides, in the sense of oligomers built exclusively with α-hydrazinoacetic units, to be observed in the solid state. The structures make it clear that the H-bond network developed by aza-β3-peptides differs radically from those of the corresponding β3-peptides but strongly resembles that of the α-aminoxy peptides. Our study contributes to the current interest in hydrazino peptides as an extension of the β-peptide concept.

Crystal structures of aza-β3-peptides, a new class of foldamers relying on a framework of hydrazinoturns

Polycrystalline samples and single crystals of the new compound Ag3In2Mo15Se19 were synthesized by solid-state reaction in a sealed molybdenum crucible at 1300 °C. Its crystal structure (space group R3c, a = 9.9755(1) A, c = 57.2943(9) A, and Z = 6) was determined from single-crystal X-ray diffraction data and constitutes an Ag-filled variant of the In2Mo15Se19 structure-type containing octahedral Mo6 and bioctahedral Mo9 clusters in a 1:1 ratio. The increase of the cationic charge transfer due to the Ag insertion induces a modification of the Mo–Mo distances within the Mo clusters that is discussed with regard to the electronic structure. Transport properties were measured in a broad temperature range (2–1000 K) to assess the thermoelectric potential of this compound. The transport data indicate an electrical conduction dominated by electrons below 25 K and by holes above this temperature. The metallic character of the transport properties in this material is consistent with electronic band structure ca...

Synthesis, Crystal and Electronic Structures, and Thermoelectric Properties of the Novel Cluster Compound Ag3In2Mo15Se19

We report on a detailed investigation of the crystal and electronic band structures and of the transport and thermodynamic properties of the Mo-based cluster compound Ag2Tl2Mo9Se11. This novel structure type crystallizes in the trigonal space group R3c and is built of a three-dimensional network of interconnected Mo9Se11 units. Single-crystal X-ray diffraction indicates that the Ag and Tl atoms are distributed in the voids of the cluster framework, both of which show unusually large anisotropic thermal ellipsoids indicative of strong local disorder. First-principles calculations show a weakly dispersive band structure around the Fermi level as well as a semiconducting ground state. The former feature naturally explains the presence of both hole-like and electron-like signals observed in Hall effect. Of particular interest is the very low thermal conductivity that remains quasi-constant between 150 and 800 K at a value of approximately 0.6 W·m(-1)·K(-1). The lattice thermal conductivity is close to its minimum possible value, that is, in a regime where the phonon mean free path nears the mean interatomic distance. Such extremely low values likely originate from the disorder induced by the Ag and Tl atoms giving rise to strong anharmonicity of the lattice vibrations. The strongly limited ability of this compound to transport heat is the key feature that leads to a dimensionless thermoelectric figure of merit ZT of 0.6 at 800 K.

X-ray characterization, electronic band structure, and thermoelectric properties of the cluster compound Ag2Tl2Mo9Se11.

We studied the effects of high pressure on the crystalline structure of scheelite-type CdMoO4 and EuMoO4. We found that the compressibility of the materials is highly nonisotropic, with the c-axis being the most compressible one. We also observed clear evidence of a structural phase transition at 12 GPa (CdMoO4) and 8.8 GPa (EuMoO4). The high-pressure phase has a monoclinic structure similar to M-fergusonite. The transition is reversible, and no volume change is detected between the low- and high-pressure phases. The results contradict early x-ray diffraction studies carried out in CdMoO4 and are compared with those obtained previously in isomorphic molybdates. Finally, the equation of state for both compounds is also determined.

Philippe Gall

Papers

Solution Synthesis and Characterization of Aza-β3-peptides (Nα-Substituted Hydrazino Acetic Acid Oligomers)

Crystal structures of aza-β3-peptides, a new class of foldamers relying on a framework of hydrazinoturns

Synthesis, Crystal and Electronic Structures, and Thermoelectric Properties of the Novel Cluster Compound Ag3In2Mo15Se19

X-ray characterization, electronic band structure, and thermoelectric properties of the cluster compound Ag2Tl2Mo9Se11.

High-pressure x-ray diffraction study of CdMoO4 and EuMoO4