Bioreactor operation shows haloplasticity of a synthetic nitrifying community, enabling urine treatment in space

Additional file 4: Figure S2. Detection of aabgl1 copy numbers in the transformants by qPCR analysis. Tef1Îą gene was used as a single copy control

Effects of Water on Mica–Ionic Liquid Interfaces

A growing body of work shows that water can affect the structure and properties of the ionic liquids near solid surfaces, which has rich ramifications in applications of ionic liquids such as lubrication and energy storage. Using molecular dynamics simulations, we investigate how water affects the three-dimensional structure of ionic liquids [BMIM]­[Tf₂N] near mica surfaces with two different charge densities. We show that water can alter not only the layering of ions near the mica surface but also their lateral and orientation ordering and the aggregation of cations’ hydrophobic tails. Water often, but not always, weakens the structuring of interfacial ionic liquids. The multifaceted impact of water on the interfacial structure of ionic liquids can be traced back to the fact that water is both a dielectric solvent and a molecular liquid. Based on the additional observations that the adsorption of water at mica–ionic liquid interfaces is enhanced by ionic liquids and surface charge, we suggest that the structure of ionic liquids near solid surfaces is governed by the three-way coupling between the self-organization of ions, the adsorption of interfacial water, and the electrification of the solid surfaces

Complex Archimedean Tiling Self-Assembled from DNA Nanostructures

Archimedean tilings are periodic polygonal tessellations that are created by placing regular polygons edge-to-edge around a vertex to fill the plane. Here we show that three- and four-arm DNA junction tiles with specifically designed arm lengths and intertile sticky-end interactions can be used to form sophisticated two-dimensional (2D) and three-dimensional (3D) tessellation patterns. We demonstrate two different complex Archimedean patterns, (3³.4²) and (3².4.3.4), and the formation of 2D lattices, 3D tubes, and sealed polygon-shaped pockets from the tessellations. The successful growth of hybrid DNA tile motif arrays suggests that it maybe possible to generate 2D quasi-crystals from DNA building blocks

P2016050386-B1-4_results.zip

<p>In our study, melon transcriptome sequencing was used to identify key genes controlling the differentiation of callus into embryogenic callus. The overall gene expression levels were higher, photosynthesis-related gene expression was increased and the pathways related to metabolic processes and secondary metabolite biosynthesis were activated in the embryogenic callus compared with the non-embryogenic callus. Therefore, the genes associated with these pathways may be closely related to the control of melon callus differentiation into embryogenic callus.<b></b></p

Freeze–Thaw-Induced Gelation of Hyaluronan: Physical Cryostructuration Correlated with Intermolecular Associations and Molecular Conformation

Physically cross-linked hydrogels from hyaluronan (hyaluronic acid, HA) were prepared by a freeze–thaw technique at low pH. The effect of the freezing–thawing of HA solutions on the formation of physical cryogels is typical for the processes of noncovalent cryostructuration that takes the advantages of mild fabrication conditions and the absence of organic solvents and toxically cross-linking agents. The effects of processing steps (freezing time and number of freeze–thaw cycles), HA molecular weight (<i>M</i>_w), and the addition of typical polycarboxylic and polyhydric small molecules such as dicarboxylic acids and polyols on the formation of HA cryotropic hydrogels were investigated. Results verified that long freezing time and repeated freeze–thaw cycles benefited the alignment of polymer chains in the unfrozen liquid microphase, thereby promoting the formation of intermolecular aggregations and dense fibrillar network structures. High <i>M</i>_w of HA endowed the cryogel with strong mechanical strength. The influences of various small molecules on the cryogelation of HA revealed the different intermolecular association patterns in the gel network. Both succinic and glutaric acids participated in HA cryogelation, whereas oxalic, malic, and tartaric acids as well as some polyols (glycol, butanediol, and glycerol) inhibited the cryostructuration of HA. Hydrogen bonding and intermolecular interactions in acidic cryogels and in neutral cryogels obtained by <i>in situ</i> neutralizing the acidic cryogel were discussed at the molecular level in correlation with intermolecular associations and molecular conformation. A gelation mechanism for HA cryogel was proposed. In addition, experimental findings showed that the neutral HA cryogels possessed enhanced thermostability, resistance to acid decomposition, and enzyme degradation which are essentially important properties for biomaterials

Rational Design of ZnFe₂O₄/In₂O₃ Nanoheterostructures: Efficient Photocatalyst for Gaseous 1,2-Dichlorobenzene Degradation and Mechanistic Insight

Novel ZnFe₂O₄/In₂O₃ hybrid nanoheterostructures with enhanced visible-light catalytic performance were fabricated by assembling ZnFe₂O₄ nanoparticles on the surface of monodispersed In₂O₃ nanospheres, and their photocatalytic performances were evaluated via the degradation of gaseous 1,2-dichlorobenzene (<i>o</i>-DCB). The catalytic activity of the resulting heterostructures for degradation of <i>o</i>-DCB was higher than that of either pure In₂O₃ or ZnFe₂O₄. The enhanced activity was mainly ascribed to the enhanced visible-light harvesting ability, efficient spatial separation, and prolonged lifetimes of photogenerated charges. Meanwhile, the main reaction intermediates including <i>o</i>-benzoquinone type species, phenolate species, formates, acetates, and maleates were verified with <i>in situ</i> FTIR spectroscopy. Additionally, a tentative catalytic reaction mechanism and the generation pathway of ^•OH over the ZnFe₂O₄/In₂O₃ nanohetero­structures were postulated. The present work provides some significative information for the eradication of harmful chlorinated volatile organic compounds and is expected to benefit the development of In₂O₃-based hybrid heterostructures

Photothermal-Responsive Lightweight Hydrogel Actuator Loaded with Polydopamine-Modified Hollow Glass Microspheres

Aquatic actuators based on the light-to-work conversion are of paramount significance for the development of cutting-edge fields including robots, micromachines, and intelligent systems. Herein, we report the design and synthesis of near-infrared light-driven hydrogel actuators through loading with lightweight polydopamine-modified hollow glass microspheres (PDA-HGMPs) into responsive poly(N-isopropylacrylamide) (PNIPAM) hydrogels. These PDA-HGMPs can not only function as an excellent photothermal agent but also accelerate the swelling/desewlling of hydrogels due to their reconstruction for polymer gel skeleton, which speeds up the response rate of hydrogel actuators. The resulting hydrogel actuator shows controlled movements under light illumination, including complex self-propellant and floating/sinking motions. As the proof-of-concept demonstrations, a self-sensing robot is conceptualized by integrating the PDA-HGMP-containing hydrogel actuator with an ultrathin and miniature pressure sensor. Hopefully, this work can offer some important insights into the research of smart aquatic soft actuators, paving the way to the potential applications in emerging fields including micromachines and intelligent systems

Facile and Controllable Modification of 3D In₂O₃ Microflowers with In₂S₃ Nanoflakes for Efficient Photocatalytic Degradation of Gaseous <i>ortho</i>-Dichlorobenzene

Novel 3D In₂S₃/In₂O₃ heterostructures comprised of 3D In₂O₃ microflowers and In₂S₃ nanoflakes were synthesized via a facile hydrothermal process followed by an in situ anion exchange reaction. In the In₂S₃/In₂O₃ heterostructures, the In₂S₃ nanoflakes were in situ generated and uniformly assembled on In₂O₃ microflowers. The microstructures, optical properties, oxygen vacancy concentration, and photoreactivity of the heterostructures could be tuned by adjusting the amount of sulfide source. The effect of In₂S₃-nanoflakes modification on the oxygen vacancy concentration, optical properties, charge carrier separation, and charge carrier lifetime of In₂O₃ were investigated systematically. The catalytic activity of the proposed heterostructures for degradation of gaseous <i>ortho</i>-dichlorobenzene (<i>o</i>-DCB, a representative chlorinated volatile organic compounds) was higher than that of either unmodified In₂O₃ or TiO₂ (P25). Meanwhile, oxygen vacancies, systematically explored by Raman, X-ray photoelectron spectroscopy (XPS), and low-temperature electron spin resonance (ESR) spectroscopy, were demonstrated to have a two-side effect on the photocatalytic performance. Particularly, the main reaction products including <i>o</i>-benzoquinone type species, phenolate species, formates, acetates, and maleates were verified with in situ FTIR spectroscopy. Additionally, ESR examination confirmed that ^•OH and ^•O₂^– were the predominant reactive oxygen species involved in the degradation of gaseous <i>o</i>-DCB. The current research provides new insight into utilizing In-based heterostructures as promising and efficient visible-spectrum-responsive catalysts for the removal of harmful chlorinated volatile organic compounds

Total Synthesis of Longeracinphyllin A

The first and asymmetric total synthesis of longeracinphyllin A, a hexacyclic <i>Daphniphyllum</i> alkaloid, has been accomplished. A tetracyclic intermediate was prepared through silver-catalyzed alkyne cyclization and Luche radical cyclization. A phosphine-promoted [3 + 2] cycloaddition reaction was exploited to construct the sterically congested E ring bearing vicinal tertiary and quaternary centers. The cyclopentenone motif was assembled by using intramolecular Horner–Wadsworth–Emmons olefination. Raney Ni reduction delivered the tertiary amine from a thioamide precursor at a late stage