Application of an electrostatically actuated cantilevered carbon nanotube with an attached mass as a bio-mass sensor

In the present paper, another latent capability of SWCNT as a mass sensor is investigated. The relationship between the resonant frequency, dynamic pull-in voltage at the resonance frequency shift, and the attached mass is established by using the nonlocal Euler–Bernoulli beam theory. Using this relationship, a general closed-form nonlinear sensor-equation has been derived for the detection of the mass attached to the SWCNT. The aim of this study and present model is to show the sensitivity of the Cantilevered SWCNT to the values and positions of attached mass. Moreover, the results indicate that by increasing the value of attached mass and considering a single non-local scaling parameter (e₀), the values of dynamic pull-in voltage at the resonance frequency shift are decreased. Because of the small scaling parameter (e₀), the mass sensitivity of carbon nanotube increases, when the position of the attached mass is in the tip of a Cantilevered SWCNT length. The authority and the accuracy of these formulas are examined with other pull-in sensor equations in literatures. The results demonstrate that the new sensor equation can be applied for CNT-based mass sensors with rational accuracy.     

Divalent Sialylated Precision Glycooligomers Binding to Polyomaviruses and the Effect of Different Linkers

Divalent precision glycooligomers terminating in N‐acetylneuraminic acid (Neu5Ac) or 3′‐sialyllactose (3′‐SL) with varying linkers between scaffold and the glycan portions are synthesized via solid phase synthesis for co‐crystallization studies with the sialic acid‐binding major capsid protein VP1 of human Trichodysplasia spinulosa‐associated Polyomavirus. High‐resolution crystal structures of complexes demonstrate that the compounds bind to VP1 depending on the favorable combination of carbohydrate ligand and linker. It is found that artificial linkers can replace portions of natural carbohydrate linkers as long as they meet certain requirements such as size or flexibility to optimize contact area between ligand and receptor binding sites. The obtained results will influence the design of future high affinity ligands based on the structures presented here, and they can serve as a blueprint to develop multivalent glycooligomers as inhibitors of viral adhesion.     

Spin texture and magnetoroton excitations at nu=1/3

Neutral spin texture (ST) excitations at nu=1/3 are directly observed for the first time by resonant inelastic light scattering. They are determined to involve two simultaneous spin flips. At low magnetic fields, the ST energy is below that of the magnetoroton minimum. With increasing in-plane magnetic field these mode energies cross at a critical ratio of the Zeeman and Coulomb energies of eta(c)=0.020+/-0.001. Surprisingly, the intensity of the ST mode grows with temperature in the range in which the magnetoroton modes collapse. The temperature dependence is interpreted in terms of a competition between coexisting phases supporting different excitations. We consider the role of the ST excitations in activated transport at nu=1/3.     

Treatment of intralocular diseases with poly(ortho ester)‐based drug delivery systems

A poly(ortho ester) (POE) has been investigated as a carrier for controlled delivery in intraocular therapy. The intraocular biocompatibility of POE was assessed in the rabbit after intravitreal as well as suprachoroidal injections. In both cases, the injection was feasible and reproducible, and the tolerance of POE was good, with no clinical or cellular signs of inflammation. The polymer degraded slowly within 2 to 3 weeks, with total bioresorption. POE allowed to sustain the release of an antifibroblastic agent in a model of glaucoma filtering surgery in the rabbit. A formulation based on POE and 5‐fluorouracil was administered to prevent the failure of the surgery. This POE formulation was effective in inhibiting the fibrotic response, allowing a local and controlled release of a small amount of the antiproliferative drug, while reducing its toxicity. Based on these results, POE appears to be a promising carrier for sustained drug delivery in treatment of intraocular affections.     

Solubility of H2S in ionic liquids [hmim][PF6], [hmim][BF4], and [hmim][Tf2N]

The solubility of hydrogen sulphide in three ionic liquids, viz. 1-hexyl-3-methylilmidazolium hexafluorophosphate ([hmim][PF₆]), 1-hexyl-3-methylimidazolium tetrafluoroborate ([hmim][BF₄]), and 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([hmim][Tf₂N]), at temperatures ranging from 303.15 K to 343.15 K and pressures up to 1.1 MPa were determined. The solubility values were correlated using the Krichevsky–Kasarnovsky equation and Henry’s constants were obtained at different temperatures. Partial molar thermodynamic functions of solvation such as standard Gibbs free energy, enthalpy, and entropy were calculated from the solubility results. Comparison of the values obtained show that the solubility of H₂S in these three ionic liquids was in the sequence: [hmim][BF₄] > [hmim][PF₆] ≈ [hmim][Tf₂N].     

Galilean invariance in the lattice-Boltzmann method and its effect on the calculation of rheological properties in suspensions

The lattice-Boltzmann method (LBM) provides an efficient simulation technique for the study of particle suspensions. These simulations provide an important tool in elucidating the effect of suspended particles on the rheology of suspensions. The most common solid–fluid boundary condition used in the LBM is the bounce-back operation, and as such, the errors introduced by this operation to the dynamics of the particles and the calculation of relevant rheological quantities must be quantified. This paper derives the Galilean invariant term in the standard bounce-back operation and shows the effect of this error on the calculation of particle dynamics and stresslet. In particular, an error is found in the calculation of normal stresses that may be significant in magnitude compared with typical values found in suspensions of rigid spherical particles. A correction is proposed, and simulation results are shown that verify the original assessment and show the reduction of error when using the proposed correction.     

Local layer structure of the steep field line defect in surface-stabilized ferroelectric liquid crystal cells

The local layer structure of one type of DC electric field induced line defect observed in CS-1014 surface stabilized ferroelectric liquid crystal electro-optic cells has been determined using X-ray scattering and optical microscopy. The characterized defect is a high contrast defect line distinct from other field lines in that a defect mirror image is not produced when the DC field direction is reversed.     

Microcanonical cluster approximations

A method of entropy estimates due to Kikuchi is generalized from Ising systems to Z₂ gauge models. This method is explicitly gauge invariant. The results of the approximation are compared to Monte Carlo data and strong coupling expansions.     

A vectorized algorithm for calculating the accessible surface area of macromolecules

An algorithm is presented for calculating the solvent accessible surface area of proteins using a three-dimensional grid. Since it requires only calculations based on single atomic positions, the algorithm is easy to be vectorized. It has been implemented on ST100 and may also be implemented on supercomputers like the CRAY or the CYBER. Results on several proteins indicate that its deviation from that of the Shrake-Rupley algorithm is very small while the computation time is much reduced.     

The spectral detectability of fluorine in a helium glow discharge

The theoretical basis of the excitation of the fluorine emission spectrum is discussed, and the negative effects of easily excited impurities are demonstrated. Fluorine can be detected by means of its emission spectrum if it is present as a minor impurity in helium. The amount of water vapor and/or organic compounds in the helium must be minimized because these substances produce easily excited fragments in the glow discharge which dissipate the energy needed to excite fluorine atoms. Direct excitation of a diphenyldifluorosilane residue permits detection of about 70 pg of fluorine; if fluorine is volatilized as hydrofluoric acid and injected directly into the glow discharge, a photocurrent peak of 1.8 Ag^-1 of fluorine is obtained.