Sequential reactions from catalytic hydroformylation toward the synthesis of amino compounds

Different families of new amino compounds were efficiently synthesized, through optimized sequential processes, involving rhodium catalyzed hydroformylation as the key step. The selection of appropriate hydroformylation catalytic systems and reaction conditions allowed obtaining aldehydes derived from several n-alkyl olefins, cholest-4-ene and 3-vinyl-1H-indole, which were subsequently transformed, in one-pot, in to α-amino acids via hydroformylation/Strecker reaction, and in to tertiary amines via hydroaminomethylation, with excellent yields.     

Photoluminescence of single quantum wires and quantum dots

The results of a study into the photoluminescence spectra of a set of quantum dots based on GaAs enclosed in AlGaAs nanowires are presented. The steady state and time resolved spectra of photoluminescence under optical excitation both from an array of quantum wires/dots and a single quantum wire/dot have been measured. In the photoluminescence spectra of single quantum dots, emission lines of excitons, biexcitons and tritons have been found. The binding energy of the biexciton in the studied structures was deduced to be 8 meV.     

X-ray absorption spectroscopy for the study of spatial Mn ion distribution in diluted magnetic semiconductors and discrete heterostructures

The X-ray K spectra of Mn absorption were used for Mn ion distribution in (Ga, Mn)N. According to the performed calculations, two threshold lines were observed in the K spectra of (Ga, Mn)N crystals with uniform Mn ion distribution. If Mn ions form chains, these two threshold lines merge into one broad line.     

Adsorption of arsenite and arsenate onto muscovite and biotite mica

Arsenite and arsenate sorption was studied on two silt-sized phyllosilicates, namely muscovite and biotite, as a function of solution pH (pH 3-8 for muscovite, and 3-11 for biotite) at an initial As concentration of 13 microM. The amount of arsenic adsorbed increases with increasing pH, exhibiting a maximum value, before decreasing at higher pH values. Maxima correspond to 3.22+/-0.06 mmol kg-1 As(V) at pH 4.6-5.6 and 2.86+/-0.05 mmol kg-1 As(III) at pH 4.1-6.2 for biotite, and 3.08+/-0.06 mmolkg-1 As(III) and 3.13+/-0.05 mmol kg-1 As(V) at pH 4.2-5.5 for muscovite. The constant capacitance surface complexation model was used to explain the adsorption behavior. Biotite provides greater reactivity than muscovite toward arsenic adsorption. Isotherm data obeyed the Freundlich or Langmuir equation for the arsenic concentration range 10(-7)-10(-4) M. Released total Fe, Si, K, Al, and Mg in solution were analyzed. Calculation of saturation indices by PHREEQC indicated that the solution was undersaturated with respect to aluminum arsenate (AlAsO42H2O), scorodite (FeAsO42H2O), and claudetite/arsenolite (As4O6).     

Investigations of food colloids by NMR and MRI

Since the publication of the ISO method for measurement of solid fat content using NMR relaxation at low field, the application of this technique to the characterisation of food composition and food structure on several length scales has expanded considerably. Improvements in the electronic and computational specifications of NMR spectrometers and the use of more sophisticated signal processing methods have led to several new applications, and NMR, previously recognized as a powerful technique to provide information regarding composition, is now widely used for microstructural investigations. Moreover, MRI applications have in recent years been extended from the medical field to food science and this has opened up new opportunities for the understanding of food. We examine here recent developments in these techniques, including NMR relaxation, multidimensional NMR relaxation, diffusion NMR and MRI.     

Strategies for kinome profiling in cancer and potential clinical applications: chemical proteomics and array-based methods

Kinases are key enzymes involved in deregulated signal transduction associated with cancer development and progression. The advent of personalized medicine drives the development of new diagnostic tools for patient stratification and therapy selection Ginsburg and Willard (Transl Res 154:277-287, 2009). Since deregulation of kinase-mediated signal transduction is implied in tumorigenesis, the analysis of all kinases (the kinome) active in a particular tumor may yield tumor-specific information on aberrant cell signalling pathways. Tumor tissue kinase activity profiles may correlate with response to therapy and therefore may be used for future therapy selection. In this Trend paper we describe peptide array and mass spectrometry-based technologies and new developments for kinome profiling, and we present an outlook towards future implementation of therapy selection based on kinome profiling in clinical practice.