Graphite-Nanoplate-Coated Bi2 S3 Composite with High-Volume Energy Density and Excellent Cycle Life for Room-Temperature Sodium-Sulfide Batteries.

Graphite-nanoplate-coated Bi2 S3 composite (Bi2 S3 @C) has been prepared by a simple, scalable, and energy-efficient precipitation method combined with ball milling. The Bi2 S3 @C composite was used as the cathode material for sodium-sulfide batteries. It delivered an initial capacity of 550 mAh g(-1) and high stable specific energy in the range of 275-300 Wh kg(-1) at 0.

Modulation of Photocatalytic Properties by Strain in 2D BiOBr Nanosheets.

BiOBr nanosheets with highly reactive {001} facets exposed were selectively synthesized by a facile hydrothermal method. The inner strain in the BiOBr nanosheets has been tuned continuously by the pH value. The photocatalytic performance of BiOBr in dye degradation can be manipulated by the strain effect.

Uniform yolk-shell iron sulfide-carbon nanospheres for superior sodium-iron sulfide batteries.

Sodium-metal sulfide battery holds great promise for sustainable and cost-effective applications. Nevertheless, achieving high capacity and cycling stability remains a great challenge. Here, uniform yolk-shell iron sulfide-carbon nanospheres have been synthesized as cathode materials for the emerging sodium sulfide battery to achieve remarkable capacity of ∼ 545 mA h g(-1) over 100 cycles at 0.

The Bacteroides sp. 3_1_23 Pif1 protein is a multifunctional helicase.

ScPif1 DNA helicase is the prototypical member of a 5'-to-3' helicase superfamily conserved from bacteria to human and plays various roles in the maintenance of genomic homeostasis. While many studies have been performed with eukaryotic Pif1 helicases, including yeast and human Pif1 proteins, the potential functions and biochemical properties of prokaryotic Pif1 helicases remain largely unknown. Here, we report the expression, purification and biochemical analysis of Pif1 helicase from Bacteroides sp.

Sodium and Lithium Storage Properties of Spray-Dried Molybdenum Disulfide-Graphene Hierarchical Microspheres.

Developing nano/micro-structures which can effectively upgrade the intriguing properties of electrode materials for energy storage devices is always a key research topic. Ultrathin nanosheets were proved to be one of the potential nanostructures due to their high specific surface area, good active contact areas and porous channels. Herein, we report a unique hierarchical micro-spherical morphology of well-stacked and completely miscible molybdenum disulfide (MoS2) nanosheets and graphene sheets, were successfully synthesized via a simple and industrial scale spray-drying technique to take the advantages of both MoS2 and graphene in terms of their high practical capacity values and high electronic conductivity, respectively.

Hydrothermal synthesis, evolution, and electrochemical performance of LiMn0.5Fe0.5PO4 nanostructures.

LiMn0.5Fe0.5PO4 (LMFP) materials are synthesized by the hydrothermal approach in an organic-free and surfactant-free aqueous solution.

Highly nitrogen doped carbon nanosheets as an efficient electrocatalyst for the oxygen reduction reaction.

In this work, highly nitrogen doped carbon nanosheets (HNCNSs) have been successfully prepared by annealing EDTA calcium disodium salt. They exhibited a direct four-electron reaction pathway and high stability as an efficient metal-free catalyst for the oxygen reduction reaction.

Tuneable Magnetic Phase Transitions in Layered CeMn2Ge(2-x)Six Compounds.

The structural and magnetic properties of seven CeMn2Ge(2-x)Six compounds with x = 0.0-2.0 have been investigated in detail.

Ambient Facile Synthesis of Gram-Scale Copper Selenide Nanostructures from Commercial Copper and Selenium Powder.

Grams of copper selenides (Cu(2-x)Se) were prepared from commercial copper and selenium powders in the presence of thiol ligands by a one-pot reaction at room temperature. The resultant copper selenides are a mixture of nanoparticles and their assembled nanosheets, and the thickness of nanosheets assembled is strongly dependent on the ratio of thiol ligand to selenium powder. The resultant Cu(2-x)Se nanostructures were treated with hydrazine solution to remove the surface ligands and then explored as a potential thermoelectric candidate in comparison with commercial copper selenide powders.

A Facile Synthesis of High-Surface-Area Sulfur-Carbon Composites for Li/S Batteries.

Small-grained elemental sulfur is precipitated from sodium thiosulfate (Na2 S2 O3 ) in a carbon-containing oxalic acid (HOOC-COOH) solution through a novel spray precipitation method. Surface area analysis, elemental mapping, and transmission electron micrographs revealed that the spray-precipitated sulfur particles feature 11 times higher surface area compared to conventional precipitated sulfur, with homogeneous distribution in the carbon. Moreover, the scanning electron micrographs show that these high-surface-area sulfur particles are firmly adhered to and covered by carbon.

BLM unfolds G-quadruplexes in different structural environments through different mechanisms.

Mutations in the RecQ DNA helicase gene BLM give rise to Bloom's syndrome, which is a rare autosomal recessive disorder characterized by genetic instability and cancer predisposition. BLM helicase is highly active in binding and unwinding G-quadruplexes (G4s), which are physiological targets for BLM, as revealed by genome-wide characterizations of gene expression of cells from BS patients. With smFRET assays, we studied the molecular mechanism of BLM-catalyzed G4 unfolding and showed that ATP is required for G4 unfolding.

Heterovalent-Doping-Enabled Efficient Dopant Luminescence and Controllable Electronic Impurity Via a New Strategy of Preparing II-VI Nanocrystals.

Substitutional heterovalent doping represents an effective method to control the optical and electronic properties of nanocrystals (NCs). Highly monodisperse II-VI NCs with deep substitutional dopants are presented. The NCs exhibit stable, dominant, and strong dopant fluorescence, and control over n- and p-type electronic impurities is achieved.

Unwinding forward and sliding back: an intermittent unwinding mode of the BLM helicase.

There are lines of evidence that the Bloom syndrome helicase, BLM, catalyzes regression of stalled replication forks and disrupts displacement loops (D-loops) formed during homologous recombination (HR). Here we constructed a forked DNA with a 3' single-stranded gap and a 5' double-stranded handle to partly mimic a stalled DNA fork and used magnetic tweezers to study BLM-catalyzed unwinding of the forked DNA. We have directly observed that the BLM helicase may slide on the opposite strand for some distance after duplex unwinding at different forces.

Performance modulation of α-MnO₂ nanowires by crystal facet engineering.

Modulation of material physical and chemical properties through selective surface engineering is currently one of the most active research fields, aimed at optimizing functional performance for applications. The activity of exposed crystal planes determines the catalytic, sensory, photocatalytic, and electrochemical behavior of a material. In the research on nanomagnets, it opens up new perspectives in the fields of nanoelectronics, spintronics, and quantum computation.

The effect of surface passivation on the structure of sulphur-rich PbS colloidal quantum dots for photovoltaic application.

The use of PbS colloidal quantum dots in photovoltaic devices is very promising because of their simple and low cost production processes and their unique properties, such as bandgap tunability and potential multiple exciton generation. Here we report the synthesis of PbS nanocrystals used for application in solar cells. The sulphur-rich nature of their surface appears to be caused by the exposure to ambient conditions.

A new, cheap, and productive FeP anode material for sodium-ion batteries.

A novel and low-cost FeP anode with a high capacity of 764.7 mA h g(-1) synthesized by a ball-milling method is reported for sodium ion batteries. Ex situ X-ray diffraction and transmission electron microscopy have been used to explore the sodium storage mechanism of FeP.

Controlled synthesis of nanoporous nickel oxide with two-dimensional shapes through thermal decomposition of metal-cyanide hybrid coordination polymers.

The urgent need for nanoporous metal oxides with highly crystallized frameworks is motivating scientists to try to discover new preparation methods, because of their wide use in practical applications. Recent work has demonstrated that two-dimensional (2D) cyanide-bridged coordination polymers (CPs) are promising materials and appropriate for this purpose (Angew. Chem.

G-quadruplexes significantly stimulate Pif1 helicase-catalyzed duplex DNA unwinding.

The evolutionarily conserved G-quadruplexes (G4s) are faithfully inherited and serve a variety of cellular functions such as telomere maintenance, gene regulation, DNA replication initiation, and epigenetic regulation. Different from the Watson-Crick base-pairing found in duplex DNA, G4s are formed via Hoogsteen base pairing and are very stable and compact DNA structures. Failure of untangling them in the cell impedes DNA-based transactions and leads to genome instability.

Superior intrinsic thermoelectric performance with zT of 1.8 in single-crystal and melt-quenched highly dense Cu(2-x)Se bulks.

Practical applications of the high temperature thermoelectric materials developed so far are partially obstructed by the costly and complicated fabrication process. In this work, we put forward two additional important properties for thermoelectric materials, high crystal symmetry and congruent melting. We propose that the recently discovered thermoelectric material Cu2-xSe, with figure of merit, zT, over 1.

One-dimensional manganese-cobalt oxide nanofibres as bi-functional cathode catalysts for rechargeable metal-air batteries.

Rechargeable metal-air batteries are considered a promising energy storage solution owing to their high theoretical energy density. The major obstacles to realising this technology include the slow kinetics of oxygen reduction and evolution on the cathode (air electrode) upon battery discharging and charging, respectively. Here, we report non-precious metal oxide catalysts based on spinel-type manganese-cobalt oxide nanofibres fabricated by an electrospinning technique.

Mapping intracellular diffusion distribution using single quantum dot tracking: compartmentalized diffusion defined by endoplasmic reticulum.

The crowded intracellular environment influences the diffusion-mediated cellular processes, such as metabolism, signaling, and transport. The hindered diffusion of macromolecules in heterogeneous cytoplasm has been studied over years, but the detailed diffusion distribution and its origin still remain unclear. Here, we introduce a novel method to map rapidly the diffusion distribution in single cells based on single-particle tracking (SPT) of quantum dots (QDs).

Effects of oxygen adsorption on the surface state of epitaxial silicene on Ag(111).

Epitaxial silicene, which is one single layer of silicon atoms packed in a honeycomb structure, demonstrates a strong interaction with the substrate that dramatically affects its electronic structure. The role of electronic coupling in the chemical reactivity between the silicene and the substrate is still unclear so far, which is of great importance for functionalization of silicene layers. Here, we report the reconstructions and hybridized electronic structures of epitaxial 4 × 4 silicene on Ag(111), which are revealed by scanning tunneling microscopy and angle-resolved photoemission spectroscopy.

Molecular mechanism of G-quadruplex unwinding helicase: sequential and repetitive unfolding of G-quadruplex by Pif1 helicase.

Recent advances in G-quadruplex (G4) studies have confirmed that G4 structures exist in living cells and may have detrimental effects on various DNA transactions. How helicases resolve G4, however, has just begun to be studied and remains largely unknown. In the present paper, we use single-molecule fluorescence assays to probe Pif1-catalysed unfolding of G4 in a DNA construct resembling an ongoing synthesis of lagging strand stalled by G4.

Unabridged phase diagram for single-phased FeSe(x)Te(1-x) thin films.

A complete phase diagram and its corresponding physical properties are essential prerequisites to understand the underlying mechanism of iron-based superconductivity. For the structurally simplest 11 (FeSeTe) system, earlier attempts using bulk samples have not been able to do so due to the fabrication difficulties. Here, thin FeSe(x)Te(1-x) films with the Se content covering the full range (0 ≤ x ≤ 1) were fabricated by using pulsed laser deposition method.