143 research outputs found
A dimeric zinc(II) complex: bis[μ-1,2-bis(1,2,4-triazol-4-yl)ethane-κ2 N 1:N 1′]bis[dinitritozinc(II)]
The coordination geometry of the ZnII atom in the title complex, [Zn2(NO2)4(C6H8N6)2], is distorted octahedral, in which the ZnII atom is coordinated by two N atoms from the triazole rings of two symmetry-related 1,2-bis(1,2,4-triazol-4-yl)ethane ligands and four O atoms from two nitrite ligands. Two ZnII atoms are bridged by two organic ligands, forming a centrosymmetric dimer. Weak C—H⋯N and C—H⋯O hydrogen bonds play an important role in the intermolecular packing
Bis(μ-4-amino-3,5-dimethyl-4H-1,2,4-triazole)bis[diiodidozinc(II)]
In the title compound, [Zn2I4(C4H8N4)2], the ZnII atom is coordinated in a distorted tetrahedral geometry by two N atoms from the triazole rings of two 4-amino-3,5-dimethyl-4H-1,2,4-triazole (admt) ligands and two iodide ligands. Doubly bridging admt ligands connect two ZnII atoms, forming a centrosymmetric dimer. Weak N—H⋯I and C—H⋯I hydrogen bonds play an important role in the intermolecular packing
Assessment of structural characteristics of regenerated cellulolytic enzyme lignin based on a mild DMSO/[Emim]OAc dissolution system from triploid of Populus tomentosa Carr.
The structural characteristics of native lignin are essential for the further deconstruction of plant cell walls for value-added application of lignocellulosic biomass.</p
Targeted disruption of fibulin-4 abolishes elastogenesis and causes perinatal lethality in mice
Elastic fibers provide tissues with elasticity which is critical to the function of arteries, lungs, skin, and other dynamic organs. Loss of elasticity is a major contributing factor in aging and diseases. However, the mechanism of elastic fiber development and assembly is poorly understood. Here, we show that lack of fibulin-4, an extracellular matrix molecule, abolishes elastogenesis. fibulin-4(−/−) mice generated by gene targeting exhibited severe lung and vascular defects including emphysema, artery tortuosity, irregularity, aneurysm, rupture, and resulting hemorrhages. All the homozygous mice died perinatally. The earliest abnormality noted was a uniformly narrowing of the descending aorta in fibulin-4(−/−) embryos at embryonic day 12.5 (E12.5). Aorta tortuosity and irregularity became noticeable at E15.5. Histological analysis demonstrated that fibulin-4(−/−) mice do not develop intact elastic fibers but contain irregular elastin aggregates. Electron microscopy revealed that the elastin aggregates are highly unusual in that they contain evenly distributed rod-like filaments, in contrast to the amorphous appearance of normal elastic fibers. Desmosine analysis indicated that elastin cross-links in fibulin-4(−/−) tissues were largely diminished. However, expression of tropoelastin or lysyl oxidase mRNA was unaffected in fibulin-4(−/−) mice. In addition, fibulin-4 strongly interacts with tropoelastin and colocalizes with elastic fibers in culture. These results demonstrate that fibulin-4 plays an irreplaceable role in elastogenesis
Coexistence of superconductivity with exotic ferromagnetic state in pressurized non-superconducting UTe
The discovery of superconductivity in heavy Fermion UTe, a candidate
topological and triplet-paired superconductor, has aroused widespread interest.
However, to date, superconductivity has only been reported in nonstoichiometric
crystals of UTe with a Te deficit. Here, we demonstrate that the
application of uniaxial pressure induces superconductivity in stoichiometric
UTe crystals. Measurements of resistivity, magnetoresistance and
susceptibility reveal that uniaxial pressure results in a suppression of the
Kondo coherent state seen at ambient pressure, leading to the emergence of
superconductivity initially at 1.5 GP, followed by the development of bulk
superconductivity at 4.8 GPa. The superconducting state coexists with an exotic
ferromagnetically ordered (FM) state that develops just below the onset
temperature of the superconducting transition. High-pressure synchrotron x-ray
diffraction measurements performed at 20 K indicate that no structural phase
transition occurs over the measured pressure range. Our results not only
demonstrate the coexistence of superconductivity with an exotic ferromagnetic
state in pressurized stoichiometric UTe, but also highlight a vital role of
Te deficiency in developing superconductivity at ambient pressures.Comment: 17 pages, 4 figure
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