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The removal of hydrophobic polymer films from surfaces is one of the top priorities of modern conservation science. Nanostructured fluids containing water, good solvents for polymers, either immiscible or partially miscible with water, and surfactants have been used in the last decade to achieve controlled removal. The dewetting of the polymer film is often an essential step to achieve efficient removal; however, the role of the surfactant throughout the process is yet to be fully understood. We report on the dewetting of a methacrylate/acrylate copolymer film induced by a ternary mixture of water, propylene carbonate (PC) and C9-11E6, a nonionic alcohol ethoxylate surfactant. The fluid microstructure was characterised through small angle X-ray scattering and the interactions between the film and water, water/PC and water/PC/C9-11E6, were monitored through confocal laser-scanning microscopy (CLSM) and analised both from a thermodynamic and a kinetic point of view. The presence of a surfactant is a prerequisite to induce dewetting of μm-thick films at room temperature, but it is not a thermodynamic driver. The amphiphile lowers the interfacial energy between the phases and favors the loss of adhesion of the polymer on glass, decreasing, in turn, the activation energy barrier, which can be overcome by the thermal fluctuations of polymer film stability, initiating the dewetting process. [ABSTRACT FROM AUTHOR]

Brinker is the key target protein of the Drosophila Decapentaplegic morphogen signalling pathway. Brinker is widely expressed and can bind with DNA. NMR spectra suggest that apo-Brinker is intrinsically unstructured and undergoes a folding transition upon DNA-binding. However, the coupled mechanism of binding and folding is poorly understood. Here, we performed molecular dynamics (MD) simulations for both bound and apo-Brinker to study the mechanism. Room-temperature MD simulations suggest that Brinker becomes more rigid and stable upon DNA-binding. Kinetic analysis of high-temperature MD simulations shows that both bound and apo-Brinker unfold viaa two-state process. The time scale of tertiary unfolding is significantly different between bound and apo-Brinker. The predicted Φ-values suggest that there are more residues with native-like transition state ensembles (TSEs) for bound Brinker than for apo-Brinker. The average RMSD differences between bound and apo-Brinker and Kolmogorov-Smirnov (KS) test analysis illustrate that Brinker folding upon DNA-binding might obey induced-fit mechanism based on MD simulations. These methods can be used for the research of other biomolecular folding upon ligand-binding. [ABSTRACT FROM AUTHOR]

MnxCo1−xSb2O4 and FexCo1−xSb2O4 have been synthesised for 0 ≤x≤ 1 and their structures and magnetic properties examined. For all compounds, neutron powder diffraction (NPD) data reveal a canted AFM structure that changes gradually from C-type (x = 0) to A-type (x = 1). This transition corresponds to a gradual rotation of the moments through 90°, from ±[001] to ±[100]. It is primarily caused by a change in the relative magnitudes of the three types of magnetic exchange that exist between cations. Within a given chain, direct exchange promotes an antiferromagnetic ground state for the two cations and 90° superexchange that favours ferromagnetic order. Between chains, antiferromagnetic order is preferred. However, the observed magnetic moments (from NPD) are significantly lower than expected except for the end-members of the series; this suggests that incomplete magnetic order is present. Magnetic susceptibility data also suggest complex magnetic behaviour except for the end-member compounds. The complex magnetic features appear to originate from composition inhomogeneity, local magnetic order in the chains of octahedra being dependent on small clusters of the same transition metal ion and the delicate energy balance that clearly exists between the two ordered configurations in the mid-composition region where x is near to 0.5. [ABSTRACT FROM AUTHOR]

The central goal in nanoscience is to achieve control of the structural characteristics of ensembles (artificial molecules) of anisotropic nanoparticles (NPs), which contain new fundamental information about plasmonically or electronically coupled single NPs. Based on their collective behavior, these artificial molecules have potential in optoelectronics and sensing. This review mainly covers different strategies for the synthesis and self-assembly of gold nanorods (GNRs), the properties of self-assembled structures, the application of such structures as sensors, and the trends and future perspective of the self-assembly of GNRs. [ABSTRACT FROM AUTHOR]

Generation of nanostructures containing from several to thousands of inorganic nanorods (NRs) organized in a highly ordered manner paves the way for applications that exploit directional properties of NR arrays. Self-assembly of NRs provides a simple and cost-efficient strategy for producing NR ensembles. This tutorial reviewhighlights recent advances in the field of NR synthesis, summarizes the types of ligands used for NR synthesis and stabilization, reviews experimental and theoretical work on NR self-assembly that is driven by interactions between the ligands and describes current properties and applications of self-assembled NR structures. [ABSTRACT FROM AUTHOR]

An efficient one-pot, three-component synthesis of highly substituted bicyclic pyridines containing a ring-junction nitrogen, starting from simple and readily available materials, is described. Cyclocondensation of heterocyclic ketene aminals (HKAs), triethoxymethane, and active methylene compounds by refluxing under solvent-free and catalyst-free conditions, provided bicyclic pyridines in excellent yields. [ABSTRACT FROM AUTHOR]

Affinity analysis is a key biotechnique used in the fields of biology and biomedicine. Herein, we advanced the concept of moving affinity boundary (MAB) using metal ion Ni(ii) and histidine (His) as the model inorganic ion and ligand, respectively, developed the simple method of MAB affinity capillary electrophoresis (MAB-ACE), and carried out the relative experiments. The experiments manifested that (a) an MAB could be created with the model metal ion and ligand; (b) the MAB-ACE could specifically capture His rather than other amino acids, or numerous metabolites in human urine; and (c) the capture had the merits of simultaneous focusing and separation to the target metabolite of His. It was further revealed that the specificity of MAB-ACE was originated from the selective affinity interaction and the effective control of affinity conditions. The analyses of His in raw urine by the MAB-ACE are in agreement with those viathe standard amino acid analyzer, indicating the reliability of the developed method. Additionally, the MAB-ACE with UV detector had good sensitivity (LOD = 43 ng mL−1, S/N = 3), 1.0–150 μM linearity and <5% intra-/inter-day variations. The novel method has an evident potential application for capture of a target metabolite in complex biological sample. [ABSTRACT FROM AUTHOR]

Storage and transport behaviors of lithium in LiF/Ti nanocomposites, either formed in situthrough a conversion reaction from TiF3powder electrode or prepared by the pulse laser deposition method, have been investigated. Reversible lithium storage in the LiF/Ti nanocomposites shows a sloped voltage profile. The lithium storage capacity in the LiF/Ti nanocomposite thin film is much higher than that in single Ti or LiF thin film with the same thickness and is increased with increasing film thickness. Accordingly, lithium should store at the grain boundary regions since either the LiF or the Ti phase is not active for lithium storage. Hence, this type of interfacial storage is intermediate between the insertion and storage in supercapacitors. The transport properties of electrons and lithium ions in initial LiF/Ti nanocomposites are also investigated by IV, IS and blocking electrode techniques. [ABSTRACT FROM AUTHOR]

We have recorded transient absorption kinetics at 390 nm with picosecond resolution in order to observe electron transfer from the reduced primary acceptor, A−0, to the secondary acceptor, A1, in wild type and mutated Photosystem I from Chlamydomonas reinhardtii. In the mutants, the methionine axial ligand to the primary electron acceptor in either the A- or B-branch of electron transfer cofactors, was replaced with histidine. Both of the mutations reduced the formation of a positive signal at 390 nm, characteristic of A−1to a level approximately half of that observed in wild type Photosystem I. It is concluded that in the mutated branch of Photosystem I, electron transfer from A−0to A1does not occur. The absorption kinetics resulting from subtraction of either of the mutants’ traces from that of wild type is interpreted to reflect the kinetics of A- or B-side electron transfer from A−0to A1in the the wild type Photosystem I. Each of these traces could be fitted with a monoexpoenential decay characterized by the same amplitude and 25–30-ps lifetime. The almost identical effect of both mutations on A−1formation confirm a similar engagement of both the A- ad B-branches in electron transfer to A1in Photosystem I from C. reinhardtii. This observation is in contrast to the unidirectional electron transfer concluded from the studies on similar mutants of cyanobacterial Photosystem I.1Thus, this contribution provides further evidence for functional differences between these two model Photosystems. [ABSTRACT FROM AUTHOR]

With the major advances in soft lithography and polymer materials, use of microfluidic devices has attracted tremendous attention recently. A simple and fast micromachining process is highly in demand to prototype such a device efficiently and economically. In this paper, we first reported an out-of-cleanroom printing-based integrated microfabrication process, referred to as the lab-on-a-print(LOP), for rapid-prototyping three-dimensional microfluidics. Using this lab-on-a-printprocess, we demonstrated the potential to accomplish an entire design-to-fabrication cycle within an hour, including about 70 µm resolution of direct-lithography patterning, well-controlled polyimide wet etching, three-dimensional pattern alignment and multilayer wax thermal-fusion packaging. A microfluidic gradient generator was prepared and tested for validation of the lab-on-a-printmicrofabrication process. [ABSTRACT FROM AUTHOR]

The ability of some ionic liquids to co-dissolve cellulose and other polymers, as well as very hydrophobic molecules, such as gas-sensing calix[4]arenes, allows for the ready construction of nitrogen oxide (NOx) sensors and storage devices. We report here the utilization of a cellulose-based platform for the immobilization of calix[4]arenes and the subsequent use of these materials for the reversible colorimetric detection of NOx. These sensors may be exposed directly to NOx gas for quick colorimetric calixarene–NO+ complexation, which can be rapidly or slowly reversed with humidity, depending on the desired application (e.g., sensing vs. storage). [ABSTRACT FROM AUTHOR]

Sintering and crystallisation phenomena in powders of a typical bioactive glass composition (45S5 Bioglass®) have been investigated in order to gain further understanding of the processes involved in the fabrication of Bioglass® based glass–ceramic scaffolds for tissue engineering applications. In situ experiments in an environmental scanning electron microscope with a heating stage were carried out to follow the morphology of Bioglass® particles during sintering and crystallisation. Optimal processing parameters for the manufacture of Bioglass® based glass–ceramic scaffolds by the foam-replica technique were determined. To assess the in vitro performance and bioreactivity of Bioglass®-derived glass–ceramic scaffolds, the biodegradation of samples in simulated body fluid (SBF) was investigated using various techniques, including SEM, TEM, XRD and EDX. The mechanism of interaction of the glass–ceramic surface with SBF was determined, which involves (i) preferential dissolution at glass/crystal interfaces, (ii) break-down of crystalline particles into very fine grains through preferential dissolution at crystal structural defects, and (iii) amorphisation of the crystalline structure by introduction of point defects produced during ion exchange. The present report thus offers for the first time a complete assessment of the processing parameters, microstructure, and in vitro performance of Bioglass® derived glass–ceramic scaffolds intended for bone tissue engineering. [ABSTRACT FROM AUTHOR]

Here, we report a simple fluorescent strip sensor based on aptamer–quantum dots technology that can meet toxin monitoring demands using ochratoxin A (OTA) as a model toxin. The limit of the detection (LOD) for the fluorescent strip was 1.9 ng mL−1, while the time needed for the detection is only 10 min; this conforms to the standards of World Health Organization (WHO) or better. Overall functional parameters are also better than the analogous characteristics of gold nanoparticle strips.High selectivity was maintained as well, making them suitable for the samples with complex solution composition. [ABSTRACT FROM AUTHOR]

An effective and safe route is proposed to prepare supported Mo2C-based catalysts from organic–inorganic hybrids, which exhibit high activity and stability for producing H2from methanol catalytic decomposition. [ABSTRACT FROM AUTHOR]

An effective and safe route is proposed to prepare supported Mo2C-based catalysts from organic–inorganic hybrids, which exhibit high activity and stability for producing H2from methanol catalytic decomposition. [ABSTRACT FROM AUTHOR]

A light-driven deazaflavin-dependent direct enzyme regeneration system has been developed for a P450-BM3 catalyzed CH-activating hydroxylation, thereby avoiding the need for the expensive NADPH cofactor. [ABSTRACT FROM AUTHOR]

We demonstrate that nanolitre-sized droplets are an effective tool in coupling two-dimensional separations in both time and space. Using a microfluidic droplet connector, chemically separated components can be segmented into nanolitre droplets. After oil filtering and droplet merging, these droplets are loaded into a second dimension for comprehensive separations. [ABSTRACT FROM AUTHOR]

A simple and novel gold nanoparticle (Au-NPs) based colorimetric method has been developed for efficient screening of class A β-lactamase (Bla) activity and inhibitors in vitroand in bacterial strains. [ABSTRACT FROM AUTHOR]

An unprecedented twofold interpenetrating (3,4)-connected topology of the Cu3L4-type metal–organic framework was prepared using N,N′,N″-tris(4-pyridinyl)-1,3,5-benzenetricarboxamide (L) as a trigonal three-connection node and the copper(ii) ion as a square planar four-connection node, where the framework contains remarkably large 1-D solvent channels. [ABSTRACT FROM AUTHOR]