Giant spin splitting through surface alloying

The long-range ordered surface alloy Bi/Ag(111) is found to exhibit a giant spin splitting of its surface electronic structure due to spin-orbit coupling, as is determined by angle-resolved photoelectron spectroscopy. First-principles electronic structure calculations fully confirm the experimental findings. The effect is brought about by a strong in-plane gradient of the crystal potential in the surface layer, in interplay with the structural asymmetry due to the surface-potential barrier. As a result, the spin polarization of the surface states is considerably rotated out of the surface plane.     

Coordination polymers and a dinuclear complex constructed from zinc(II) ions and fluorescein: iodine adsorption and optical properties

Abstract

1-D coordination polymers, ¹_∞[Zn(fl)₂]·2EtOH and ¹_∞[Zn(fl)₂]·2MeOH, and a dinuclear complex, [{Zn(fl)₂}₂(dienpip)]·4H₂O·4EtOH (dienpip?= N,N′-bis(2-aminoethyl)piperazine), were obtained using Zn(II) ions and fluorescein anions (fl). Thermal analysis shows stability of the polymers after solvent removal up to more than 400?°C. Crystallization solvent molecules were removed under reduced pressure with the preservation of the polymeric structure, ¹_∞[Zn(fl)₂]. Desolvated crystals were exposed to I₂ vapors and the crystal structure determination by X-ray diffraction confirmed the presence of I₂ molecules in the channels generated in crystals by the metal-organic framework. The iodine content, evaluated by X-ray diffraction, corresponds to the overall formula ¹_∞[Zn(fl)₂]·0.3I₂. The optical properties of the coordination polymers and the dinuclear complex have been investigated.     

Optimization of Biocompatibility for a Hydrophilic Biological Molecule Encapsulation System

Despite considerable advances in recent years, challenges in delivery and storage of biological drugs persist and may delay or prohibit their clinical application. Though nanoparticle-based approaches for small molecule drug encapsulation are mature, encapsulation of proteins remains problematic due to destabilization of the protein. Reverse micelles composed of decylmonoacyl glycerol (10MAG) and lauryldimethylamino-N-oxide (LDAO) in low-viscosity alkanes have been shown to preserve the structure and stability of a wide range of biological macromolecules. Here, we present a first step on developing this system as a future platform for storage and delivery of biological drugs by replacing the non-biocompatible alkane solvent with solvents currently used in small molecule delivery systems. Using a novel screening approach, we performed a comprehensive evaluation of the 10MAG/LDAO system using two preparation methods across seven biocompatible solvents with analysis of toxicity and encapsulation efficiency for each solvent. By using an inexpensive hydrophilic small molecule to test a wide range of conditions, we identify optimal solvent properties for further development. We validate the predictions from this screen with preliminary protein encapsulation tests. The insight provided lays the foundation for further development of this system toward long-term room-temperature storage of biologics or toward water-in-oil-in-water biologic delivery systems.     

A Polynomial Time Approximation Scheme for the Grade of Service Steiner Minimum Tree Problem

In this paper, we present the design of a Polynomial Time Approximation Scheme (PTAS) for the Grade of Service Steiner Minimum Tree (GOSST) problem, which is known to be NP-Complete. Previous research has focused on geometric analyses and different approximation algorithms have been designed. We propose a PTAS that provides a polynomial time, near-optimal solution with performance ratio 1+. The GOSST problem has some important applications. In network design, a fundamental issue for the physical construction of a network structure is the interconnection of many communication sites with the best choice of the connecting lines and the best allocation of the transmission capacities over these lines. Good solutions should provide paths with enough communication capacities between any two sites, with the least network construction costs. Also, the GOSST problem has applications in transportation, for road constructions and some potential uses in CAD in terms of interconnecting the elements on a plane to provide enough flux between any two elements.     

Photodissociation of isobutene at 193 nm

The collisionless photodissociation dynamics of isobutene (i-C(4)H(8)) at 193 nm via photofragment translational spectroscopy are reported. Two major photodissociation channels were identified: H + C(4)H(7) and CH(3) + CH(3)CCH(2). Translational energy distributions indicate that both channels result from statistical decay on the ground state surface. Although the CH(3) loss channel lies 13 kcal mol(-1) higher in energy, the CH(3):H branching ratio was found to be 1.7 (5), in reasonable agreement with RRKM calculations.     

Characterization of β-cyclodextrin inclusion complex with procaine hydrochloride by 1H NMR and ITC

The inclusion of local anesthetic drug procaine hydrochloride by β-cyclodextrin was investigated by 1D and 2D proton NMR spectroscopy and isothermal titration calorimetry (ITC) at 298 K. The stoichiometry of the complex was determinate by the method of continuous variation, using the chemical induced shift of both host and guest protons. The association constant K, of the obtained complex was calculated and found to be 293.17 M^?1. Rotating frame NOE spectroscopy, was used to ascertain the solution geometry of the host–guest complex. The result reveals that the procaine molecule penetrates into the β-cyclodextrin cavity with the aromatic ring. The energetics of complexation process is investigated by ITC technique. The analysis indicates that the complexation of procaine by β-CD is an exothermic process and show that both enthalpy and entropy contribute to the binding process. The obtained value for the association constant is in good agreement with that obtained from NMR.     

Homogenization heat treatment and segregation analysis of equiaxed CMSX-4 superalloy for gas turbine components

Journal of Thermal Analysis and Calorimetry - Two new zinc(II) coordination compounds have been synthesized by the reaction of diazine-ring containing Schiff bases di(2-pyridyl) ketone...     

Ethylethanolammonium 4-nitrobenzoate

Journal of Thermal Analysis and Calorimetry - In the present studies, the thermal behaviour of NaUO2BO3 has been investigated. This compound is a potential product of interaction between the...     

Spectral,thermal and biological characterization of complexes with a Schiff base bearing triazole moiety as potential antimicrobial species

Journal of Thermal Analysis and Calorimetry - A novel series of complexes ML(ClO4)·nH2O (M: Co, Ni, Cu, Zn; HL: 2-[(E)-(1H-1,2,4-triazol-3-ylimino)methyl]phenol) have been synthesized and...