527 research outputs found
Bis(μ-4-hydroxybenzoato-κ2 O:O′)bis[triaquabis(4-hydroxybenzoato)-κO;κ2 O,O′-terbium(III)] decahydrate
The title dinuclear compound, [Tb2(C7H5O3)6(H2O)6]·10H2O, lies on a center of inversion and the two TbIII atoms are bridged by two 4-hydroxybenzoate anions; each metal atom is further coordinated by one monodentate anion and chelated by the third anion. The eight-coordinate geometry approximates a square antiprism. Hydrogen bonds of the O—H⋯O type connect the uncoordinated water molecules to the dinuclear species, forming a three-dimensional network
In situ growth of redox-active iron-centered nanoparticles on graphene sheets for specific capacitance enhancement
AbstractA fast and facile approach is proposed to enhance the specific capacitance of N-Methyl-2-pyrrolidone (NMP)-exfoliated graphene. Redox-active nickel ferricyanide (NiFeCN) nanoparticles were grown on the surface of graphene sheets using a simple co-precipitation method. Apart from the synergetic effect of graphene as double layer capacitance and NiFeCN as pseudocapacitance in specific capacitance enhancement, the NiFeCN nanoparticles served as the spacer to prevent the graphene sheets agglomeration. The NiFeCN/graphene exhibited specific capacitance of 113.5Fg−1, which was 2 times higher than the NMP-exfoliated graphene (52Fg−1) and 6times higher than the pure NiFeCN (18Fg−1). The findings suggested the NiFeCN/graphene could be the potential candidate for supercapacitor electrode
Mechanism of Evolution Shared by Gene and Language
We propose a general mechanism for evolution to explain the diversity of gene
and language. To quantify their common features and reveal the hidden
structures, several statistical properties and patterns are examined based on a
new method called the rank-rank analysis. We find that the classical
correspondence, "domain plays the role of word in gene language", is not
rigorous, and propose to replace domain by protein. In addition, we devise a
new evolution unit, syllgram, to include the characteristics of spoken and
written language. Based on the correspondence between (protein, domain) and
(word, syllgram), we discover that both gene and language shared a common
scaling structure and scale-free network. Like the Rosetta stone, this work may
help decipher the secret behind non-coding DNA and unknown languages.Comment: 15 pages, 13 figures, 3 tabl
5,5-Bis(hydroxymethyl)-2-phenyl-1,3-dioxane
In the title compound, C12H16O4, the 1,3-dioxane ring adopts a chair conformation; the 2-phenyl substitutent occupies an equatorial position. Adjacent molecules are linked by O—H⋯O hydrogen bonds into a chain
Methyl 2-(4-chloro-3,5-dinitrobenzamido)acetate
The title molecule, C10H8ClN3O7, is twisted with the dihedral angle between the amide and benzene ring being 38.75 (11)°. The C—N—C—C torsion angle between the amide and acetyl groups is −150.1 (2)°. Finally, each nitro group is twisted out of the plane of the benzene ring to which it is connected [O—N—C—C torsion angles = 34.0 (3) and −64.5 (3)°]. Linear supramolecular chains along [010] and mediated by N—H⋯O hydrogen bonds between successive amide groups dominate the crystal packing. The chains are consolidated into the three-dimensional structure by C—H⋯O contacts
X-ray Astronomy in the Laboratory with a Miniature Compact Object Produced by Laser-Driven Implosion
Laboratory spectroscopy of non-thermal equilibrium plasmas photoionized by
intense radiation is a key to understanding compact objects, such as black
holes, based on astronomical observations. This paper describes an experiment
to study photoionizing plasmas in laboratory under well-defined and genuine
conditions. Photoionized plasma is here generated using a 0.5-keV Planckian
x-ray source created by means of a laser-driven implosion. The measured x-ray
spectrum from the photoionized silicon plasma resembles those observed from the
binary stars Cygnus X-3 and Vela X-1 with the Chandra x-ray satellite. This
demonstrates that an extreme radiation field was produced in the laboratory,
however, the theoretical interpretation of the laboratory spectrum
significantly contradicts the generally accepted explanations in x-ray
astronomy. This model experiment offers a novel test bed for validation and
verification of computational codes used in x-ray astronomy.Comment: 5 pages, 4 figures are included. This is the original submitted
version of the manuscript to be published in Nature Physic
Functionally heterogeneous human satellite cells identified by single cell RNA sequencing.
Although heterogeneity is recognized within the murine satellite cell pool, a comprehensive understanding of distinct subpopulations and their functional relevance in human satellite cells is lacking. We used a combination of single cell RNA sequencing and flow cytometry to identify, distinguish, and physically separate novel subpopulations of human PAX7+ satellite cells (Hu-MuSCs) from normal muscles. We found that, although relatively homogeneous compared to activated satellite cells and committed progenitors, the Hu-MuSC pool contains clusters of transcriptionally distinct cells with consistency across human individuals. New surface marker combinations were enriched in transcriptional subclusters, including a subpopulation of Hu-MuSCs marked by CXCR4/CD29/CD56/CAV1 (CAV1+). In vitro, CAV1+ Hu-MuSCs are morphologically distinct, and characterized by resistance to activation compared to CAV1- Hu-MuSCs. In vivo, CAV1+ Hu-MuSCs demonstrated increased engraftment after transplantation. Our findings provide a comprehensive transcriptional view of normal Hu-MuSCs and describe new heterogeneity, enabling separation of functionally distinct human satellite cell subpopulations
Chromosome segregation in Archaea : SegA– and SegB–DNA complex structures provide insights into segrosome assembly
Genome segregation is a vital process in all organisms. Chromosome partitioning remains obscure in Archaea, the third domain of life. Here, we investigated the SegAB system from Sulfolobus solfataricus. SegA is a ParA Walker-type ATPase and SegB is a site-specific DNA-binding protein. We determined the structures of both proteins and those of SegA–DNA and SegB–DNA complexes. The SegA structure revealed an atypical, novel non-sandwich dimer that binds DNA either in the presence or in the absence of ATP. The SegB structure disclosed a ribbon–helix–helix motif through which the protein binds DNA site specifically. The association of multiple interacting SegB dimers with the DNA results in a higher order chromatin-like structure. The unstructured SegB N-terminus plays an essential catalytic role in stimulating SegA ATPase activity and an architectural regulatory role in segrosome (SegA–SegB–DNA) formation. Electron microscopy results also provide a compact ring-like segrosome structure related to chromosome organization. These findings contribute a novel mechanistic perspective on archaeal chromosome segregation
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Genome-wide trans-ancestry meta-analysis provides insight into the genetic architecture of type 2 diabetes susceptibility.
To further understanding of the genetic basis of type 2 diabetes (T2D) susceptibility, we aggregated published meta-analyses of genome-wide association studies (GWAS), including 26,488 cases and 83,964 controls of European, east Asian, south Asian and Mexican and Mexican American ancestry. We observed a significant excess in the directional consistency of T2D risk alleles across ancestry groups, even at SNPs demonstrating only weak evidence of association. By following up the strongest signals of association from the trans-ethnic meta-analysis in an additional 21,491 cases and 55,647 controls of European ancestry, we identified seven new T2D susceptibility loci. Furthermore, we observed considerable improvements in the fine-mapping resolution of common variant association signals at several T2D susceptibility loci. These observations highlight the benefits of trans-ethnic GWAS for the discovery and characterization of complex trait loci and emphasize an exciting opportunity to extend insight into the genetic architecture and pathogenesis of human diseases across populations of diverse ancestry
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