Ultrafast X‑ray Diffraction Probe of Coherent Spin-State Dynamics in Molecules

We propose an approach to probe coherent spin-state dynamics of molecules using circularly polarized hard X-ray pulses. For the dynamically aligned nitric oxide molecules in a coherent superposition spin–orbit coupled electronic state that can be prepared through stimulated Raman scattering, we demonstrate the capability of ultrafast X-ray diffraction to not only reveal the quantum beating of the coherent spin-state wave packet but also image the spatial spin density of the molecule. With a circularly polarized ultrafast X-ray diffraction signal, we show that the electronic density matrix can be retrieved. The spatiotemporal resolving power of ultrafast X-ray diffraction paves the way for tracking transient spatial wave function in molecular dynamics involving the spin degree of freedom

Flexible NiO–Graphene–Carbon Fiber Mats Containing Multifunctional Graphene for High Stability and High Specific Capacity Lithium-Ion Storage

An electrode’s conductivity, ion diffusion rate, and flexibility are critical factors in determining its performance in a lithium-ion battery. In this study, NiO–carbon fibers were modified with multifunctional graphene sheets, resulting in flexible mats. These mats displayed high conductivities, and the transformation of active NiO to inert Ni⁰ was effectively prevented at relatively low annealing temperatures in the presence of graphene. The mats were also highly flexible and contained large gaps for the rapid diffusion of ions, because of the addition of graphene sheets. The flexible NiO–graphene–carbon fiber mats achieved a reversible capacity of 750 mA h/g after 350 cycles at a current density of 500 mA/g as the binder-free anodes of lithium-ion batteries. The mats’ rate capacities were also higher than those of either the NiO–carbon fibers or the graphene–carbon fibers. This work should provide a new route toward improving the mechanical properties, conductivities, and stabilities of mats using multifunctional graphene

Role of Humic Acid in Enhancing Dissolved Air Flotation for the Removal of TiO₂ Nanoparticles

The particle separation efficiency by flotation sharply decreases or even completely fails when the diameter of dispersed particles falls into the nanoscale. In the present laboratory work, humic acid was used to enhance the removal of TiO₂ nanoparticles from suspension in a chemical coagulant-free dissolved air flotation process. Without humic acid, merely 63.8% of TiO₂ nanoparticles were removed. For the humic acid-assisted dissolved air flotation, the pH of humic acid solution significantly influenced the removal efficiency: more than 90% of nanoparticles could be separated when the pH of the humic acid stock solution was acidic; however, the basic solutions resulted in rather poor performance. In the acidic solution, the fiberlike humic acid might form colloids through the attraction between hydrophobic moieties. They possibly acted as a fishnet and trapped nanoparticles, leading to the great measured bubble–particle attachment efficiency. In all the effluents, a low residual dissolved organic carbon was observed, revealing a good participation of humic acid in flotation. Moreover, a higher air-to-solid ratio could improve the nanoparticle elimination by offering a larger surface area of air bubbles. The fractal dimension of flotation flocs demonstrated that the aggregates with compact structure took greater advantage in the flotation separation of nanoparticles

Eight 3D lines (in pink color) on two orthogonal planes used in the simulations, where the small pyramids stand for camera viewpoints.

<p>Eight 3D lines (in pink color) on two orthogonal planes used in the simulations, where the small pyramids stand for camera viewpoints.</p

Drug Repositioning for Diabetes Based on 'Omics' Data Mining

<div><p>Drug repositioning has shorter developmental time, lower cost and less safety risk than traditional drug development process. The current study aims to repurpose marketed drugs and clinical candidates for new indications in diabetes treatment by mining clinical ‘omics’ data. We analyzed data from genome wide association studies (GWAS), proteomics and metabolomics studies and revealed a total of 992 proteins as potential anti-diabetic targets in human. Information on the drugs that target these 992 proteins was retrieved from the Therapeutic Target Database (TTD) and 108 of these proteins are drug targets with drug projects information. Research and preclinical drug targets were excluded and 35 of the 108 proteins were selected as druggable proteins. Among them, five proteins were known targets for treating diabetes. Based on the pathogenesis knowledge gathered from the OMIM and PubMed databases, 12 protein targets of 58 drugs were found to have a new indication for treating diabetes. CMap (connectivity map) was used to compare the gene expression patterns of cells treated by these 58 drugs and that of cells treated by known anti-diabetic drugs or diabetes risk causing compounds. As a result, 9 drugs were found to have the potential to treat diabetes. Among the 9 drugs, 4 drugs (diflunisal, nabumetone, niflumic acid and valdecoxib) targeting COX2 (prostaglandin G/H synthase 2) were repurposed for treating type 1 diabetes, and 2 drugs (phenoxybenzamine and idazoxan) targeting ADRA2A (Alpha-2A adrenergic receptor) had a new indication for treating type 2 diabetes. These findings indicated that ‘omics’ data mining based drug repositioning is a potentially powerful tool to discover novel anti-diabetic indications from marketed drugs and clinical candidates. Furthermore, the results of our study could be related to other disorders, such as Alzheimer’s disease.</p></div

Pickering Emulsion as an Efficient Platform for Enzymatic Reactions without Stirring

To address the current limitations of enzymatic reactions, we develop a novel strategy to conduct stirring-free biphasic enzymatic reactions. This strategy involves translation of a conventional biphasic enzymatic reaction to a water-in-oil (W/O) Pickering emulsion system by adding a small amount of solid particle emulsifier. In such a system, enzymes, for example, a <i>Candida Antarctica</i> lipase B (CALB), are compartmentalized within millions of micron-sized water droplets, while organic substrates are dissolved in the oil phase (outside the droplets). It was demonstrated that CALB-catalyzed hydrolysis kinetic resolution of racemic esters in the stirring-free Pickering emulsion system gave favorable reaction efficiency and enantioselectivity as compared to those for the conventional biphasic system under stirring conditions, which was due to the large reaction interfacial area and the short molecule distances created by the Pickering emulsion droplets. The specific activity was found to depend on the water droplet size, highlighting the importance of the presence of droplets in the reaction system. Moreover, the convenient and effective recycling of CALB could be achieved through simple demulsification by centrifugation. After 27 reaction cycles, the ee values of ester and alcohol were still as high as 87.5% and 99%, respectively, which significantly exceed those of the conventional biphasic reaction. The high recyclability may be attributed to avoiding stirring that often causes damage to the three-dimensional structure of enzymes. This study compellingly demonstrates that a Pickering emulsion is an innovative platform to efficiently process enzymatic reactions without need for stirring and immobilization

Flow-chart of drug repositioning by mining ‘omics’ data.

<p>We retrieved 17 GWAS studies, 18 proteomics studies and 19 metabolomics studies that assessed diabetes patients until August 2014. 115 genes, 56 proteins and 227 metabolites were significantly associated with diabetes. An HMDB search revealed 1660 metabolite-protein pairs corresponding to 840 proteins. Overall, 992 unique proteins associated with diabetes were gathered and mapped to the TTD database and 108 of them had drug projects information. After removing those under experimental and preclinical stages, we obtained 35 protein targets, including 5 known anti-diabetic targets (27 drugs projects) and 30 unknown anti-diabetic targets (167 drugs projects). Pathogenesis knowledge was retrieved from the OMIM and Pubmed databases, 12 targets corresponding to 58 drugs were indicated to have novel indication for diabetes treatment. CMap analysis indicated that 9 of the 58 drugs have the potential to treat diabetes.</p

Psychophysiological interaction (PPI) analysis with the POJ as the source region and with the ‘Near > Far’ contrast as the psychological factor.

<p>The source region in the POJ is marked in red. (A) PPI activation in ‘match’ condition. Both the dorsal and ventral streams (blue) showed significant context-dependent co-variations with the neural activity in the POJ. The coupling was stronger in the far space than in the near space. In order to give a clearer view of ventral cortical structures, the cerebellum was removed in the ventral view display. PPI analysis based on the neural activity in the POJ (red) for a representative participants were shown. Mean corrected neural activity in the right inferior occipital gyrus, the left fusiform gyrus, the left inferior temporal gyrus, the left superior parietal gyrus and the right precuneus is displayed as a function of mean corrected activity in the POJ (i.e., first principal component from a sphere of 4 mm radius) in the near space (blue dots and lines) and far space (red dots and lines) blocks. (B) PPI activation in ‘natural’ condition. Both the dorsal and ventral streams (blue) showed significant context-dependent co-variations with the neural activity in the POJ. The coupling was stronger in the far space than in the near space. In order to give a clearer view of ventral cortical structures, the cerebellum was removed in the ventral view display. PPI analysis based on the neural activity in the POJ (red) for a representative participants were shown. Mean corrected neural activity in the left inferior occipital gyrus, the right fusiform gyrus, the right lingual gyrus, the right middle occipital gyrus, the left precuneus is displayed as a function of mean corrected activity in the POJ (i.e., first principal component from a sphere of 4 mm radius) in the near space (blue dots and lines) and far space (red dots and lines) blocks.</p

Size-Tunable Hydrothermal Synthesis of SnS₂ Nanocrystals with High Performance in Visible Light-Driven Photocatalytic Reduction of Aqueous Cr(VI)

SnS₂ nanocrystals with adjustable sizes were synthesized via a hydrothermal method from the aqueous solution of common and inexpensive SnCl₄·5H₂O, thioacetamide and citric acid, simply by varying the reaction temperature and reaction time. The structures, Brunauer–Emmett–Teller (BET) specific surface areas and optical properties of the resultant SnS₂ nanocrystals were characterized by X-ray diffraction, transmission electron microscopy, N₂ adsorption/desorption isotherms, and UV–vis diffuse reflectance spectra. Besides, their photocatalytic properties were tested for the reduction of aqueous Cr(VI) under visible light (λ > 420 nm) irradiation. It was found that the photocatalytic activities of SnS₂ nanocrystals in aqueous suspension depended on their synthesis conditions. The product synthesized under suitable hydrothermal conditions (for example, at 150 °C for 12 h) not only showed high visible light-driven photocatalytic activity in the reduction of aqueous Cr(VI), but also showed good photocatalytic stability. Our photocatalytic results suggested that SnS₂ nanocrystals are a promising photocatalyst in the efficient utilization of solar energy for the treatment of Cr(VI)-containing wastewater

Distances between the edges on the unit cube by the three metrics.

<p>Distances between the edges on the unit cube by the three metrics.</p