First synthesis of a new fullerene oximes bis(9-[hydroxo]-1-[1′-hydroxymino-2′-oxo-2′-alkyl-ethyl])1,9-dihydro-[C60-Ih][5,6]fullerenes via reaction of C60 with ketones and NaNO2 promoted by HCl

A mixture of cis-2 and cis-3 isomers of new fullerene derivatives bis(9-[hydroxo]-1-[1′-hydroxymino-2′-oxo-2′-alkyl-ethyl])-1,9-dihydro-[C₆₀-I_h][5,6]fullerenes have been selectively synthesized with high yields at the reaction of C₆₀ fullerene with ketones Me₂CO, EtMeCO, i-PrMeCO, PhMeCO in the presence of NaNO₂ and HCl.     

Interval-Affine Gaussian Algorithm for Constrained Systems

The paper presents interval-affine Gaussian algorithm for the interval linear systems Ax = b subject to some constraints on real matrices A from the interval matrix A. The interval-affine method is based on the so-called interval-affine arithmetic that allows to take the constraints into account during the computation of interval enclosures of the united solution set of the system Ax = b, and to make the estimates more accurate.     

Sequence of a cytochrome c gene from Kluyveromyces lactis and its upstream region

The complete sequence of a cytochrome c gene from Kluyveromyces lactis including its upstream region is reported. Sequence of the translated open reading frame is discussed in terms of cytochrome c structural requirements. Putative regulatory signals in the upstream region are described and compared with reported sequences which modulate the expression of respiratory-related yeast genes.     

Small-molecule vacuum processed melamine-C60, organic field-effect transistors

The transfer of benchtop knowledge into large scale industrial production processes represents a challenge in the field of organic electronics. Large scale industrial production of organic electronics is envisioned as roll to roll (R2R) processing which nowadays comprises usually solution-based large area printing steps. The search for a fast and reliable fabrication process able to accommodate the deposition of both insulator and semiconductor layers in a single step is still under way. Here we report on the fabrication of organic field effect transistors comprising only evaporable small molecules. Moreover, both the gate dielectric (melamine) and the semiconductor (C₆₀) are deposited in successive steps without breaking the vacuum in the evaporation chamber. The material characteristics of evaporated melamine thin films as well as their dielectric properties are investigated, suggesting the applicability of vacuum processed melamine for gate dielectric layer in OFETs. The transistor fabrication and its transfer and output characteristics are presented along with observations that lead to the fabrication of stable and virtually hysteresis-free transistors. The extremely low price of precursor materials and the ease of fabrication recommend the evaporation processes as alternative methods for a large scale, R2R production of organic field effect transistors.     

Switching Ion Binding Selectivity of Thiacalix[4]arene Monocrowns at Liquid–Liquid and 2D-Confined Interfaces

Understanding the interaction of ions with organic receptors in confined space is of fundamental importance and could advance nanoelectronics and sensor design. In this work, metal ion complexation of conformationally varied thiacalix[4]monocrowns bearing lower-rim hydroxy (type I), dodecyloxy (type II), or methoxy (type III) fragments was evaluated. At the liquid–liquid interface, alkylated thiacalixcrowns-5(6) selectively extract alkali metal ions according to the induced-fit concept, whereas crown-4 receptors were ineffective due to distortion of the crown-ether cavity, as predicted by quantum-chemical calculations. In type-I ligands, alkali-metal ion extraction by the solvent-accessible crown-ether cavity was prevented, which resulted in competitive Ag⁺ extraction by sulfide bridges. Surprisingly, amphiphilic type-I/II conjugates moderately extracted other metal ions, which was attributed to calixarene aggregation in salt aqueous phase and supported by dynamic light scattering measurements. Cation–monolayer interactions at the air–water interface were monitored by surface pressure/potential measurements and UV/visible reflection–absorption spectroscopy. Topology-varied selectivity was evidenced, towards Sr²⁺ (crown-4), K⁺ (crown-5), and Ag⁺ (crown-6) in type-I receptors and Na⁺ (crown-4), Ca²⁺ (crown-5), and Cs⁺ (crown-6) in type-II receptors. Nuclear magnetic resonance and electronic absorption spectroscopy revealed exocyclic coordination in type-I ligands and cation–π interactions in type-II ligands.     

Effect of Processing Temperature on the Texture and Shear Mechanical Properties of Diffusion Bonded Ti-6Al-4V Multilayer Laminates

Two multilayer materials based on Ti-6Al-4V alloy have been processed by diffusion bonding at two different temperatures [1023 K and 1173 K (750 °C and 900 °C)]. The influence of the processing temperature on microstructure, texture, and mechanical properties of the two multilayer materials has been analyzed. Scanning electron microscopy, X-ray diffraction, electron backscatter diffraction, and shear tests have been used as experimental techniques. The multilayer laminate processed at the lowest temperature of 1023 K (750 °C) exhibits mainly transversal texture in the longitudinal plane, which provides an anisotropic mechanical behavior, showing higher shear modulus and maximum shear strength under one of the shear test directions considered. In contrast, diffusion bonding at 1173 K (900 °C) leads to basal/transversal texture because of the partial α → β → α transformation, which provides more isotropic mechanical properties. Accordingly, this laminate shows similar shear modulus and maximum shear strength in different shear test orientations.     

Analysis and sorption of psychoactive drugs onto sediment

An analytical method was developed to analyze eight psychoactive pharmaceuticals--including the antiepileptic carbamazepine, the opiates morphine, codeine, dihydrocodeine, the opiode tramadol, and the tranquilizers diazepam, oxazepam, temazepam--and the antibiotic sulfamethoxazole as well as three metabolites (10,11-dihydrocarbamazepine (DHC), 10,11-dihydroxy-10, 11-dihydrocarbamazepine, and N4-acetylsulfamethoxazole) in river sediments. Relative recoveries of all analytes exceeded 97% using either deuterated or 13C15N-labeled surrogate standards. Sorption isotherms of all analytes were constructed at pH 6.5-6.6 on two natural river sediments (Burgen and Dausenau) that differed in organic carbon contents and particle size distributions. Affinities of all analytes were up to an order of magnitude higher for the Dausenau sediment in comparison to the Burgen sediment. Isotherms were well described by the Freundlich model. Sorption of all analytes was linear on the Burgen sediment except for structurally similar carbamazepine (n = 0.90) and DHC (n = 0.88). Conversely, most analytes showed pronounced nonlinear sorption to the Dausenau sediment (n = 0.77-0.92) except for positively charged codeine, dihydrocodeine, and tramadol. Linear sorption of the latter was taken to arise from concentration-independent electrostatic interactions of the organocations with negatively charged surfaces on clay minerals or in the sediment organic matter. Desorption gave rise to hysteresis in 13 out of 16 investigated analyte-sorbent systems. Hysteresis was likely due to slow desorption kinetics beyond 24 h used in the experiment.