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CD47 is over-expressed in Acute Myeloid Leukemia (AML) and functions as an inhibitory signal, suppressing phagocytosis by binding to signal regulatory protein α (SIRPα) on the surface of macrophages. Inhibition of CD47 restores the immune surveillance of AML cells. However, the inhibition of CD47 in AML by activated macrophages and the subsequent effects on different immune response parameters are not fully understood. Here, we demonstrate the use of a distinct co-culture method to inhibit CD47 and therefore eliminate AML cells by macrophages in vitro. Human chemically induced THP-1 macrophages were activated using different concentrations of lipopolysaccharide (LPS) and co-culturing with three AML cancer cell lines (HL-60, NB4, and THP-1), respectively, as well as normal human peripheral blood mononuclear cells (PBMC). CD47 inhibition was observed in and selective to AML but not observed in normal PBMC. Additionally, calreticulin (CRT) levels were elevated in the same cell lines simultaneously, after co-culturing with activated human macrophages, but not elevated in normal cells. We also show that the activated macrophages secreted high levels of cytokines, including IL-12p70, IL-6, and TNF-α, consistent with the elimination of AML by macrophages. Our study reveals the potential of this model for screening new drugs against AML and the possibility of using human macrophages in AML treatment in the future. [ABSTRACT FROM AUTHOR]

Transient pump–probe measurements have been made on betaine-30, the solvent polarity probe. Betaine-30 is composed of organic donor and acceptor groups, D+A-⇄kethνDA (excited state). The transient data has been analyzed to measure ket, the electron transfer (et) rate constant, in polar solvents for this inverted regime et. The observed rate constant ket,obs in various polar solvents is as much as a factor of 108 larger than is predicted by the standard, classical, implementation of the theory of Sumi and Marcus, using Kjaer and Ulstrup’s estimates for necessary parameters. In contrast, a quantum treatment of the vibrational modes by Jortner and Bixon, which includes the dynamic solvent effect, predicts that the rate should be approximately ket,JB[bar_over_tilde:_approx._equal_to]1/〈τs>. This is close to the experimental results ([bar_over_tilde:_approx._equal_to]1012 s-1) in typical polar aprotic solvents. However, in highly viscous, slowly relaxing solvents, ket,JB≪ket,obs. This is taken as evidence that the efficient coupling modes for the et in these environments is not the ‘‘conventional solvent coordinate.’’ It is shown that a hybrid of the Jortner/Bixon and Sumi/Marcus theories can physically account for the results. The kinetic behavior of betaine-30 in slowly relaxing solvents is shown to be in the ‘‘diffusionless limit’’ of the hybrid, generalized Sumi–Marcus/Jortner–Bixon picture. [ABSTRACT FROM AUTHOR]

Controlling sea lice (epeophtheirus salmonis) infestations has been a constant challenge encountered in the aquaculture industry. Currently, pesticides such as emamectin benzoate are widely employed due to their large safety margin and efficacy against all stages of sea lice. Unfortunately, the widespread use of emamectin benzoate has also led to resistance among sea lice. In this study, we present the findings of a tank trial that demonstrate the efficacy of neem extract as a potential alternative biopesticide for controlling sea lice infestations. In particular, the accumulation and depletion of an active ingredient, azadirachtin A, in Atlantic salmon (S. salar) was monitored closely by HPLC/MS/MS. Azadirachtin A levels as low as 0.01 mg azadirachtin A/kg tissue (0.01 ppm) in tissue of salmon resulted in decrease in the attachment of sea lice (>75% efficacy) relative to control tanks. • Tank trial shows efficacy of neem extract as potential biopesticide for controlling sea lice infestations • A sensitive HPLC-MS/MS method was developed to monitor the tissue concentration of azadirachtin A. • Salmon offered neem exhibited attachment of fewer sea lice relative to both control and emamectin benzoate treatment groups • No observable adverse effects, such as lethargy, physical deformities, and mortalities, were noted among fish offered neem • Azadirachtin A exhibited a clearance time in salmon tissue more rapid than the rate of hydrolysis [ABSTRACT FROM AUTHOR]

Hydrophobic interactions guide protein folding, multidomain protein assembly, receptor–ligand binding, membrane formation, and cellular transportation. On the macroscale, hydrophobic interactions consist of the aggregation of “oil-like” objects in water by minimizing the interfacial energy. However, studies of the hydration behavior of small hydrophobic molecules have shown that the microscopic (∼1 nm) hydration mechanism differs fundamentally from its macroscopic counterpart. Theoretical studies over the last two decades have pointed to an intricate dependence of molecular hydration mechanisms on the length scale. The microscopic-to-macroscopic crossover length scale is critically important to hydrophobic interactions in polymers, proteins, and other macromolecules. Accurate experimental determination of hydration mechanisms and interaction strengths directly influence our understanding of protein folding. [ABSTRACT FROM AUTHOR]

Hydrophobicity underpins self-assembly in many natural and synthetic molecular and nanoscale systems. A signature of hydrophobicity is its temperature dependence. The first experimental evaluation of the temperature and size dependence of hydration free energy in a single hydrophobic polymer is reported, which tests key assumptions in models of hydrophobic interactions in protein folding. Herein, the hydration free energy required to extend three hydrophobic polymers with differently sized aromatic side chains was directly measured by single molecule force spectroscopy. The results are threefold. First, the hydration free energy per monomer is found to be strongly dependent on temperature and does not follow interfacial thermodynamics. Second, the temperature dependence profiles are distinct among the three hydrophobic polymers as a result of a hydrophobic size effect at the subnanometer scale. Third, the hydration free energy of a monomer on a macromolecule is different from a free monomer; corrections for the reduced hydration free energy due to hydrophobic interaction from neighboring units are required. [ABSTRACT FROM AUTHOR]

The hydrophobic interaction is significantly responsible for driving protein folding and self-assembly. To understand it, the thermodynamics, the role of water structure, the dewetting process surrounding hydrophobes, and related aspects have undergone extensive investigations. Here, we examine the hypothesis that polymer-solvent interfacial free energy is adequate to describe the energetics of the collapse of a hydrophobic homopolymer chain at fixed temperature, which serves as a much simplified model for studying the hydrophobic collapse of a protein. This implies that changes in polymer-solvent interfacial free energy should be directly proportional to the force to extend a collapsed polymer into a bad solvent. To test this hypothesis, we undertook single-molecule force spectroscopy on a collapsed, single, polystyrene chain in water-ethanol and water-salt mixtures where we measured the monomer solvation free energy from an ensemble average conformations. Different proportions within the binary mixture were used to create solvents with different interfacial free energies with polystyrene. In these mixed solvents, we observed a linear correlation between the interfacial free energy and the force required to extend the chain into solution, which is a direct measure of the solvation free energy per monomer on a single chain at room temperature. A simple analytical model compares favorably with the experimental results. This knowledge supports a common assumption that explicit water solvent may not be necessary for cases whose primary concerns are hydrophobic interactions and hydrophobic hydration. [ABSTRACT FROM AUTHOR]

The mechanical properties of the adhesive produced by spores of the green, marine, fouling alga Ulva linza are reported. Atomic force microscopy studies were performed and nanoindentation data were analyzed using a model for an asymmetric indenter. Freshly secreted adhesive is characterized by multiple layers. We found that the modulus of the outer ∼⃒600-nm thick layer was about 0.2 ± 0.1 MPa, whereas the modulus of the inner layer was about 3 ± 1 MPa. Older adhesive showed the formation of a “crust” of harder material with a yield strength of ∼⃒20 MPa at a loading rate of 2.5 × 10 -6 N · s -1 . Mechanical properties under tension are also described, and extension profiles that showed either constant or nonlinear force changes with tip-sample separation were observed. Models for both kinds of behavior are described. The work of adhesion between poly-dimethylsiloxane (PDMS)-coated AFM tips and the adhesive was determined to be less than 1.5 mJ · m -2 . [ABSTRACT FROM AUTHOR]

Electrical and mechanical properties of metal-molecule-metal junctions formed between Au- supported self-assembled monolayers (SAMs) of electroactive 11-ferrocenylundecanethiol (FcC11SH) and a Pt-coated atomic force microscope (AFM) tip have been measured using a conducting probe (CP) AFM in insulating alkane solution. Simultaneous and independent measurements of currents and bias-dependent adhesion forces under different applied tip biases between the conductive AFM probe and the FcC11SH SAMs revealed reversible peak-shaped current-voltage (I- V) characteristics and correlated maxima in the potential-dependent adhesion force. Trapped positive charges in the molecular junction correlate with high conduction in a feature showing negative differential resistance. Similar measurements on an electropassive 1-octanethiol SAM did not show any peaks in either adhesion force or I- V curves. A mechanism involving two-step resonant hole transfer through the occupied molecular orbitals (MOs) of ferrocene end groups via sequential oxidation and subsequent reduction, where a hole is trapped by the phonon relaxation, is proposed to explain the observed current-force correlation. These results suggest a new approach to probe charge-transfer involving electroactive groups on the nanoscale by measuring the adhesion forces as a function of applied bias in an electrolyte-free environment. [ABSTRACT FROM AUTHOR]

A retrospective on the life of chemical physicist Paul F. Barbara is presented.

We hereby propose the use of stable, biocompatible, and uniformly sized polymeric micelles as high-radiotracer-payload carriers at region-of-interest with negligible background activity due to no or low offsite radiolysis. We modified glycol chitosan (GC) polymer with varying levels of palmitoylation (P) and quaternization (Q). Quaternary ammonium palmitoyl glycol chitosan (GCPQ) with a Q:P ratio of 9:35 (Q9P35GC) offers >99% biocompatibility at 10 mg mL−1. Q9P35GC micelles exhibit >99% 99mTechnetium (99mTc) radiolabeling via the stannous chloride reduction method without heat. The 99mTc-Q9P35GC micelles (65 ± 3 nm) exhibit >98% 6 h serum stability at 37 °C and 7 day of radiochemical stability at 25 °C. HepG2 cells show a higher uptake of FITC-Q9P35GC than Q13P15GC and Q20P15GC. The in vivo 24 h organ cumulated activity (MBq h) order follows: liver (234.4) > kidneys (60.95) > GIT (0.73) > spleen (88.84). The liver to organ ratio remains higher than 2.4, rendering a better contrast in the liver. The radiotracer uptake decreases significantly in fibrotic vs. normal liver, whereas a blocking study with excess Q9P35GC significantly decreases the radiotracer uptake in a healthy vs. fibrotic liver. FITC-Q9P35GC shows in vivo hepato-specific uptake. Radiotracer liver uptake profile follows reversible binding kinetics with data fitting to two-tissue compartmental (2T), and graphical Ichise multilinear analysis (MA2) with lower AIC and higher R2 values, respectively. The study concludes that 99mTc-Q9P35GC can be a robust radiotracer for noninvasive hepatocyte function assessment and diagnosis of liver fibrosis. Furthermore, its multifunctional properties enable it to be a promising platform for nanotheranostic applications. [ABSTRACT FROM AUTHOR]

Scattering type scanning near-field optical microscopy (s-SNOM) allows sub diffraction limited spatial resolution. Interferometric homodyne detection in s-SNOM can amplify the signal and extract vibrational responses based on sample absorption. A stable reference phase is required for a high quality homodyne-detected near-field signal. This work presents the development of a phase stabilization mechanism for s-SNOM to provide stable homodyne conditions. The phase stability is found to be better than 0.05 rad for the mid infrared light source. Phase stabilization results in improved near field images and vibrational spectroscopies. Spatial inhomogeneities of the boron nitride nanotubes are measured and compared. [ABSTRACT FROM AUTHOR]

Abstract: The present work reports the synthesis and hydrogen storage properties of different types of boron nitride (BN) nanostructures prepared by an in situ silica-assisted catalytic chemical vapor deposition technique. The BN nanostructures have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Brunauer, Emmett, and Teller (BET), Raman spectroscopy and Fourier transform infrared (FTIR) spectroscopy studies. The hydrogen storage properties of BN nanostructures have been investigated using a high-pressure Seiverts'' apparatus in the pressure range of 1–100bar and at 298K. The dependence of hydrogen storage capacity on the morphology of BN nanostructures is discussed in detail. [Copyright &y& Elsevier]

An interferometric method is used to enhance the weak scattered signal in apertureless near-field scanning infrared microscopy. The method involves introducing a homodyning reference field, and amplifies the desired signal field by the magnitude of the reference field. This method markedly improves the signal-to-noise ratio of the detected signal, over the nonhomodyned experiment. A model for the dependence of the near-field signal, as a function of the normal distance of the tip from the surface, is discussed. Application of a model in which the tip is represented by two spherical scatterers, one large and one small, indicates the electromagnetic field enhancement is 90-fold greater at the sharp apex of the metallic probe tip. [ABSTRACT FROM AUTHOR]

Presents a study that constructed and combined solid state Ti:sapphire lasers with nonlinear optics to produce a resolution absorption spectrometer with specific tunability and sensitivity levels. Tunable light generation and array detection technology; Suitability of different infrared nonlinear optical materials.

The inverted regime photoinduced electron transfer kinetics of betaine-30 have been investigated over a broad temperature range, revealing very little temperature dependence. For example, for betaine-30 in a polystyrene film, the electron transfer rate constant, kET, changes by less than a factor of 3 from T=293 K to T=34 K. The results are in striking contrast to predictions of contemporary electron transfer theories which employ classical nuclear modes to accept some or all of the energy of the electron transfer event. The comparison of theory and experiment for the betaines demonstrates that a full quantum mechanical theory is necessary to accurately describe the electron transfer kinetics of the betaines in environments with slow dielectric relaxation. The conclusions drawn for the betaines may also apply to other molecular examples of inverted regime electron transfer in slowly relaxing environments. [ABSTRACT FROM AUTHOR]

It is currently the consensus belief that protective osmolytes such as trimethylamine N-oxide (TMAO) favor protein folding by being excluded from the vicinity of a protein, whereas denaturing osmolytes such as urea lead to protein unfolding by strongly binding to the surface. Despite there being consensus on how TMAO and urea affect proteins as a whole, very little is known as to their effects on the individual mechanisms responsible for protein structure formation, especially hydrophobic association. In the present study, we use single-molecule atomic force microscopy and molecular dynamics simulations to investigate the effects of TMAO and urea on the unfolding of the hydrophobic homopolymer polystyrene. Incorporated with interfacial energy measurements, our results show that TMAO and urea act on polystyrene as a protectant and a denaturant, respectively, while complying with Tanford--Wyman preferential binding theory. We provide a molecular explanation suggesting that TMAO molecules have a greater thermodynamic binding affinity with the collapsed conformation of polystyrene than with the extended conformation, while the reverse is true for urea molecules. Results presented here from both experiment and simulation are in line with earlier predictions on a model Lennard--Jones polymer while also demonstrating the distinction in the mechanism of osmolyte action between protein and hydrophobic polymer. This marks, to our knowledge, the first experimental observation of TMAO-induced hydrophobic collapse in a ternary aqueous system. [ABSTRACT FROM AUTHOR]

Non-specific adsorption of biomolecules (or 'biofouling') is a major problem in microfluidics and many other applications. The problem is particularly pernicious in digital microfluidics (DMF, a technique in which droplets are manipulated electrodynamically on an array of electrodes coated with a hydrophobic insulator), as local increases in surface energy that arise from fouling can cause droplet movement to fail. We report a new solution to this problem: a device coating bearing a combination of fluorinated poly(ethylene glycol) functionalities (FPEG) and perfluorinated methacrylate (FA) moieties. A range of different FPEG-FA copolymers were synthesized containing varying amounts of FPEG relative to the fluorinated backbone. Coatings with low%FPEG were found to result in significant reductions in protein adsorption and improvements in device lifetime (up to 5.5-fold) relative to the state of the art. An analysis of surface topology and chemistry suggests that FPEG-FA surfaces undergo a dynamic reconstruction upon activation by applying DMF driving potentials, with FPEG groups forming vertical protrusions out of the plane of the device surface. An analysis of changes in surface wettability and adhesion as a function of activation supports this hypothesis. This innovation represents an advance for digital microfluidics, and may also find use in other applications that are currently limited by biofouling. [ABSTRACT FROM AUTHOR]

Solution-based linearself-assembly of metal nanoparticles offersa powerful strategy for creating plasmonic polymers, which, so far,have been formed from spherical nanoparticles and cylindrical nanorods.Here we report linear solution-based self-assembly of metal nanocubes(NCs), examine the structural characteristics of the NC chains, anddemonstrate their advanced optical characteristics. In comparisonwith chains of nanospheres with similar dimensions, composition, andsurface chemistry, predominant face-to-face assembly of large NCscoated with short polymer ligands led to a larger volume of hot spotsin the chains, a nearly uniform E-field enhancement in the gaps betweencolinear NCs, and a new coupling mode for NC chains due to the formationof a Fabry–Perot resonatorstructure formed by face-to-face bonded NCs. The NC chains exhibitedstronger surface-enhanced Raman scattering in comparison with linearassemblies of nanospheres. The experimental results were in agreementwith finite difference time domain simulations. [ABSTRACT FROM AUTHOR]

The labeling of cell surface receptors by fluorescentmarkers is an established method for the identification of cell phenotypein both research and clinical settings. Fluorescence dye labelinghas inherent constraints, most notably the upper limit of labels percell that may be probed using a single excitation source, in additionto a physical limit to the number of broad emission spectra that canbe distinctly collected within the visible wavelength region. SERSlabeling has the potential to mitigate these shortfalls. Herein, antibody-targeted,PEG-coated surface-enhanced Raman scattering (SERS) Au nanoparticlesare used simultaneously to label three cell surface markers of intereston malignant B cells from the LY10 lymphoma cell line. The SERS probeswere characterized by multiple methods to confirm their monodispersityand functionalization with both PEG and monoclonal antibodies. Thespecificity of the particles’ cell labeling was demonstratedon both primary chronic lymphocytic leukemia and LY10 cells usingSERS from cell suspensions and confocal Raman mapping, respectively.Fluorescence flow cytometry was employed to confirm the binding ofSERS probes to LY10 over large cell populations, and the particles’SERS was collected directly from labeled cells using a commercialflow cytometer. To the best of our knowledge, this is the first demonstrationof SERS flow cytometry from cells tagged with targeted SERS probes. [ABSTRACT FROM AUTHOR]

The effect of temperature during solvent annealing on the microdomain orientation of block copolymer ultrathin films was investigated using symmetric polystyrene-block-poly(methyl methacrylate) diblock copolymers. When acetone solvent annealing was performed at low temperatures, 2 °C, 38% of samples exhibited a pattern of cylinders perpendicular to the substrate, while 62% of the samples exhibited a mixture of cylinders orientated parallel and perpendicular to the substrate. In the case of acetone solvent annealing at room temperature, only 6% of samples exhibited a pattern with cylinders perpendicular to the substrate, while 73% of the samples exhibited a mixture of cylinders orientated parallel and perpendicular to the substrate. We discuss how the morphology is affected by temperature during solvent annealing. The low-temperature method was used to pattern cylinders perpendicular to the substrate using PS-b-PMMA copolymers with molecular weight ranging from 52 000 g/mol per block to 160 000 g/mol per block. [ABSTRACT FROM AUTHOR]

Amyloid fibril diseases are characterized by the abnormal production of aggregated proteins and are associated with many types of neuro- and physically degenerative diseases. X-ray diffraction techniques, solid-state magic-angle spinning NMR spectroscopy, circular dichroism (CD) spectroscopy, and transmission electron microscopy studies have been utilized to detect and examine the chemical, electronic, material, and structural properties of amyloid fibrils at up to angstrom spatial resolution. However, X-ray diffraction studies require crystals of the fibril to be analyzed, while other techniques can only probe the bulk solution or solid samples. In the work reported here, apertureless near-field scanning infrared microscopy (ANSIM) was used to probe the secondary structure of individual amyloid fibrils made from an in vitro solution. Simultaneous topographic and infrared images of individual amyloid fibrils synthesized from the #21-31 peptide fragment of β2-microglobulin were acquired. Using this technique, IR spectra of the amyloid fibrils were obtained with a spatial resolution of less than 30 nm. It is observed that the experimental scattered field spectrum correlates strongly with that calculated using the far-field absorption spectrum. The near-field images of the amyloid fibrils exhibit much lower scattering of the IR radiation at approximately 1630 cm-1. In addition, the near-field images also indicate that composition and/or structural variations among individual amyloid fibrils were present. [ABSTRACT FROM AUTHOR]

Abstract: Selective targeting and detection of a hematologic malignancy, chronic lymphocytic leukemia, using surface enhanced Raman scattering (SERS) gold nanoparticles is reported. The functional nanoparticles were composed of a gold core onto which an optical reporter dye was adsorbed, protected from aggregation by grafted polyethyleneglycol, and targeted to CD19 antigen by antibodies. The signals were detected by dark-field microscopy and Raman spectrometry. The observation that the Raman signals are not disrupted by several traditional pathology stains indicates advantages over fluorescence methods. [Copyright &y& Elsevier]

Abstract: To date, the calcareous tubes of serpulid marine worms have not been studied extensively in a biomineralization context. The structure and composition of the tube shell and adhesive cement of the marine tubeworm Hydroides dianthus were studied using a variety of characterization techniques, including powder XRD, FTIR, SEM, EDX, and AFM. The tube and cement were determined to be inorganic–organic composite materials, consisting of inorganic aragonite (CaCO3) and Mg-calcite ((Ca0.8Mg0.2)CO3) crystals, and both soluble and insoluble organic matrices (SOM and IOM). SEM imaging revealed a variety of crystal morphologies. AFM nanoindentation of the inorganic components yielded Young’s moduli of ∼20GPa in the wet state, and ∼50GPa in the dry state. Amino acid analysis of the SOM indicated substantial amounts of acidic and non-polar neutral amino acids. Part of the insoluble organic tube lining was identified as being composed of collagen-containing fibres aligned in a criss-crossed structure. The SOM and organic tube lining were found to contain carboxylated and sulphated polysaccharides. In an artificial seawater solution, the SOM and the organic tube lining mediated CaCO3 mineralization in vitro. [Copyright &y& Elsevier]

Organized arrays of anisotropic nanoparticles show electronic and optical properties that originate from the coupling of shape-dependent properties of the individual nanorods. The organization of nanorods in a controllable and predictable way provides a route to the fabrication of new materials and functional devices. So far, significant progress has been achieved in the self-assembly of nanorod arrays, yet the realization of a range of different structures requires changing the surface chemistry of the nanoparticles. We organized metal nanorods in structures with varying geometries by using a striking analogy between amphiphilic ABA triblock copolymers and the hydrophilic nanorods tethered with hydrophobic polymer chains at both ends. The self-assembly was tuneable and reversible and it was achieved solely by changing the solvent quality for the constituent blocks. This approach provides a new route to the organization of anisotropic nanoparticles by using the strategies that are established for the self-assembly of block copolymers. [ABSTRACT FROM AUTHOR]

We report a microfluidic approach to generating capsules of biopolymer hydrogels. Droplets of an aqueous solution of a biopolymer were emulsified in an organic phase comprising a cross-linking agent. Polymer gelation was achieved in situ (on a microfluidic chip) by diffusion-controlled ionic cross-linking of the biopolymer, following the transfer of the cross-linking agent from the continuous phase to the droplets. Gelation was quenched by collecting particles in a large pool of cross-linking agent-free liquid. The structure of microgels (from capsules to gradient microgels to particles with a uniform structure) was controlled by varying the time of residence of droplets on the microfluidic chip and the concentration of the cross-linking agent in the continuous phase. We demonstrated the encapsulation of a controlled number of polystyrene beads in the microgel capsules. The described approach was applied to the preparation of capsules of several polysaccharides such as alginate, κ-carrageenan, and carboxymethylcellulose. [ABSTRACT FROM AUTHOR]

Single-molecule studies under poor solvent conditions show that atomic force microscopy (AFM) measurements of contour lengths of polystyrene 12K and 17K relate well to gel permeation chromatography (GPC) data when grafting concentrations are low (not greater than 0.7 mM). Contact angles and ellipsometry have been used to characterize the surfaces and indicate low grafting densities at this grafting concentration. Persistence lengths ( p ) of different length polystyrene chains, when fitted to a WLC (worm-like chain) model, show values of p = 0.23 nm±0.10 nm and p = 0.25 nm±0.13 nm, for 12 K and 17 K polystyrene, respectively, when the persistence lengths are fitted to log-normal distributions. These values are close to the expected theoretical value of 0.23 nm and further confirm that mostly single molecules were studied on these polystyrene surfaces. Higher grafting concentrations (≥1 mM) resulted in pulling multiple molecules. [ABSTRACT FROM AUTHOR]

The effect of deposition rate of silver (Ag) cathode on the device performance of organic light-emitting diodes (OLEDs) has been investigated. The leaky current before the turn-on of devices was observed in the samples that have the Ag cathode deposited at relatively low rate (less than 0.5 Å/s), and their emission efficiencies were found to be undesirably inconsistent. These issues were not observed in the samples that have Ag cathode deposited at higher rate (>1.0 Å/s). Here we show that the pixel-to-pixel uniformity of OLEDs employing Ag cathode can be simply improved by depositing the cathode at high rate, since the rapid deposition suppresses the Ag diffusion into underlying organic layer. • High thermal deposition rate of Ag cathode could effectively reduce current leakage and improve the emission uniformity for large-area OLEDs. • The low-rate processed Ag cathode could blur the cathode/organic interface and the interfacial metal diffusion was problem trigger. • High-rate processing was more capable to immobilize Ag clusters, and thus refining cathode morphology and structure. [ABSTRACT FROM AUTHOR]

This work systematically evaluates the effect of array periodicity on the near infrared transmission characteristics of annular aperture arrays (AAAs) in gold films. Both the experimental and theoretical transmission spectra of AAAs are shown to be sensitive to the period and the arrangement of the apertures within the array. The spectra of square arrays with periods ranging from 1400 to 600 nm show a strong correlation with surface plasmon polariton (SPP)-Bloch modes of the metal/dielectric interfaces. For rectangular AAAs the transmission spectra are significantly attenuated and reveal a polarization sensitivity that arises from the breaking of the symmetry and degeneracy of the SPP-Bloch modes. [ABSTRACT FROM AUTHOR]

Investigates the noncovalent engineering of carbon nanotube surfaces by conjugated polymers. Molecular structure of single-walled carbon nanotubes; Variation of the polymer side chain; Introduction of neutral and ionic functional groups into the nanotube surface.

An antifouling coating that improves digital microfluidic device lifetime up to 5.5‐fold relative to the state of the art is described by A. R. Wheeler and team on page 506. The material is dynamic: under standard conditions, the surface is flat and fluorinated; upon applying an electrical potential, the surface becomes activated, forming nanometer‐sized fluoropegylated structures that resist protein adhesion. (Image credit: Bill Dai.) [ABSTRACT FROM AUTHOR]