Self‐Assembled Functional DNA Superstructures as High‐Density and Versatile Recognition Elements for Printed Paper Sensors

Micrometer‐sized functional nucleic acid (FNA) superstructures (denoted as 3D DNA) were examined as a unique class of biorecognition elements to produce highly functional bioactive paper surfaces. 3D DNA containing repeating sequences of either a DNA aptamer or DNAzyme was created from long‐chain products of rolling circle amplification followed by salt aging. The resulting 3D DNA retained its original spherical shape upon inkjet printing and adhered strongly to the paper surface via physisorption. 3D DNA paper sensors showed resistance to degradation by nucleases, suppressed nonspecific protein adsorption, and provided a much higher surface density of functional DNA relative to monomeric FNAs, making such species ideally suited for development of paper‐based biosensors.     

Effect of load on structural and frictional properties of alkanethiol self-assembled monolayers on gold: some odd-even effects

We have conducted molecular dynamics simulations to study the frictional properties of alkanethiols CH(3)(CH(2))(n-1)SH (Cn, 12 ≤ n ≤ 15) self-assembled monolayers (SAMs) on Au(111) surfaces, under various loading and shearing conditions. For the examined alkanethiols, we found some evidence of the friction coefficient being dependent on the number of carbon atoms in the molecule being odd or even. Alkanethiols with n = odd show consistently higher friction coefficients than those with n = even. Such odd-even effect seems to be independent of the sliding velocity. However, the effect is significant only at lower loads (<700 MPa). The structural origin of this odd-even effect has been discussed. The effect of loading on the structure is also studied. For dodecanethiol (n = 12) we find the film responds to increased loading initially by increasing the tilt and then by deformation of individual molecules. SAM-Au contacts under shear show periodic storage and release of energy and a clear stick-slip pattern in the shear stress, film thickness, and the tilt and tilt orientation angles.     

Applications of Transition‐Metal‐Catalyzed Asymmetric Allylic Substitution in Total Synthesis of Natural Products: An Update

Metal‐catalyzed asymmetric allylic substitution (AAS) reaction is one of the most synthetically useful reactions catalyzed by metal complexes for the formation of carbon‐carbon and carbon‐heteroatom bonds. It comprises the substitution of allylic substrates with a wide range of nucleophiles or S_N2′‐type allylic substitution, which results in the formation of the above‐mentioned bonds with high levels of enantioselective induction. AAS reaction tolerates a broad range of functional groups, thus has been successfully applied in the asymmetric synthesis of a wide range of optically pure compounds. This reaction has been extensively used in the total synthesis of several complex molecules, especially natural products. In this review, we try to highlight the applications of metal (Pd, Ir, Mo, or Cu)‐catalyzed AAS reaction in the total synthesis of the biologically active natural products, as a key step, updating the subject from 2003 till date.     

Antibacterial glass films prepared on metal surfaces by sol–gel method

This paper describes the preparation and characterization of glass films consisting of SiO₂, Li₂O, Na₂O, K₂O or MgO in varying compositions on stainless steel and aluminum substrates by sol–gel method. Silver phosphate or silver incorporated zeolite was also introduced into the sols for obtaining antibacterial effect. The SiO₂/Li₂O/Na₂O system having the composition of 85:5:10 wt% was found as the optimum for obtaining a stable sol and film formation. The films were investigated by scanning electron microscopy (SEM) and electron dispersive analysis by X-ray (EDX), Fourier transformed infrared (FTIR) spectroscopy, thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA). Homogenous films having 300 ± 20 nm thicknesses were formed by spin coating and then by curing at 500 °C for 1 h. Obtained films had high adherence to the metal substrates and they were also durable in acidic, basic or NaCl environments. They also presented a powerful antibacterial effect against E. coli.     

Trapping and reflection of solitons with different frequencies upon concurrent collisions in an anisotropic medium

The variational method and numerical simulation have been used to investigate the modes of velocity and frequency transformation upon concurrent collisions of soliton laser pulses in an anisotropic medium. Excitation of bound states of optical and THz solitons affects decisively collisions at a small group velocity mismatch.     

Quantized electron accumulation states in indium nitride studied by angle-resolved photoemission spectroscopy

Electron accumulation states in InN have been measured using high resolution angle-resolved photoemission spectroscopy (ARPES). The electrons in the accumulation layer have been discovered to reside in quantum well states. ARPES was also used to measure the Fermi surface of these quantum well states, as well as their constant binding energy contours below the Fermi level E(F). The energy of the Fermi level and the size of the Fermi surface for these quantum well states could be controlled by varying the method of surface preparation. This is the first unambiguous observation that electrons in the InN accumulation layer are quantized and the first time the Fermi surface associated with such states has been measured.     

Bound State Solutions of the Dirac Equation for the Eckart Potential with Coulomb-Like Yukawa-Like Tensor Interactions

In this paper, we present the approximate bound state solutions of the Dirac equation within the framework of spin and pseudospin symmetries for Eckart potential for arbitrary κ—state using Nikiforov–Uvarov method. The tensor interactions of Coulomb-like and Yukawa-like form are considered and the effects of these tensors and the degeneracy removing role are discussed in detail. Numerical results and figures to show the effect of the tensor interactions are also reported.     

Transition energies of neutral and singly ionized lanthanum

We have calculated the transition energies (ionization potential, excitation energies, electron affinity) of neutral lanthanum (La I) and singly ionized lanthanum (La II). The calculations are based upon the multiconfiguration Hartree-Fock (MCHF) method within the framework of Breit-Pauli relativistic corrections. These energies are important for determination of physical and chemical properties for La I and La II. Results obtained have been compared with other works.     

Crystal Structure of N-(tert-Butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)cyclohexane Carboxamide

Abstract  The crystal structure of N-(tert-butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)-cyclohexane-carboxamide 1 has been determined. The title compound crystallized in the orthorhombic space group pbca with cell parameters, a = 10.6556(6) ?, b = 18.0132(11) ?, c = 19.5513(12) ?, v = 3752.7(4) ?³, Z = 8, D _cal = 1.269 Mg/m³ at T = 120 K. The structure refined by full-matrix least-squares procedures to find R ₁ = 0.0463 and wR ₂ = 0.0937 for 3059 reflections. The soxazole ring isn’t coplanar with the phenyl ring. Index Abstract  The crystal structure of N-(tert-butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)-cyclohexane-carboxamide 1 has been studied.