Hierarchical Archimedean Dependence in Common Shock Models

Methodology and Computing in Applied Probability - In this paper we show how to extend a simple common shock model with Archimedean dependence of the hidden variables to the non-exchangeable case....     

Alkoxyallene‐ynes: Selective Preparation of Bicyclo[5.3.0] Ring Systems Including a δ‐Alkoxy Cyclopentadienone

The development of an intramolecular rhodium(I)‐catalyzed Pauson–Khand reaction of alkoxyallene‐ynes with a proximal alkoxy group is reported. This reaction, in the presence of a [Rh(cycloocta‐1,5‐diene)Cl]₂/propane‐1,3‐diylbis(diphenylphosphane) system under a CO atmosphere, constitutes a powerful tool for selectively accessing carbo‐ and heterobicyclo[5.3.0] frameworks featuring an enol ether moiety. Through this procedure, a straightforward access to guaiane skeletons with a tertiary hydroxy group at the C10 position was achieved.     

Ca and Mg determination from inhabitants of Brazil using neutron activation analysis

In this study the neutron activation analysis (NAA) technique was applied to determine Ca and Mg in whole blood from inhabitants of Brazil for the purpose of establishing concentration ranges indicative of sex and age. The initiative to perform these measurements is related to the increase in heart disease. According to recent statistics from WHO, the average is one death due to heart attack in Brazil, every five minutes. The measures were performed considering lifestyle factors (non-smokers, non-drinkers and no history of toxicological exposure) of Brazilian inhabitants. A healthy group constituted of male (n = 94) and female (n = 84) blood donors, ages between 18 and 70 years and above 50 kg, was selected from the blood banks and hematological laboratories of Brazil. The influence of sex was also investigated considering several age ranges (18–29, 30–40, 41–50, >50 years). The results show significant differences when a comparison is made by sex and age and may be useful to identify or prevent clinical diseases. These results emphasize the need to perform periodic evaluation of Ca and Mg in blood.     

New π-Extended Donors: Synthesis,Characterization, Electrochemical and Electrical Conductivity Studies

A new series of tetrathiafulvalene (TTF) molecules with extended π-system was prepared by using a Wittig reaction to generate the TTF key. The process of deprotection-alkylation of thiolates provided access to a wide variety of molecules. The study of their reducing power was carried out by cyclic voltammetry. Charge transfer complexes have also been chemically prepared by using TCNQ as an electron acceptor; the electrical conductivity of their compressed powders shows insulator behavior. The IR spectra of the TCNQ salts were recorded and used to characterize and estimate the degree of charge transfer of these complexes.

GRAPHICAL ABSTRACT      

Catalytic Borylation of SCF3‐Functionalized Arenes by Rhodium(I) Boryl Complexes: Regioselective C?H Activation at the ortho‐Position

An unprecedented reaction pathway for the borylation of SCF₃‐containing arenes using [Rh(Bpin)(PEt₃)₃] (pin=pinacolato) is reported. Catalytic processes were developed and the functionalizations proceed under mild reaction conditions. The C H activations occur with a unique regioselectivity for the position ortho to the SCF₃ group, which apparently serves as directing group. Borylated SCF₃ compounds can serve as versatile building blocks.     

Development and validation of a capillary electrophoresis method for determination of enantiomeric purity and related substances of esomeprazole in raw material and pellets

A capillary electrophoresis method using CDs for quality control of esomeprazole (ESO) in terms of enantiomeric purity and related substances in raw material and pellets was developed. ESO is the S‐enantiomer of omeprazole (OMZ). Several parameters were evaluated, including type and concentration of buffer and CD, concentration of additives and electrolyte pH. Resolution between the enantiomers of OMZ obtained for each parameter tested was calculated and the presence of the main related substance such as OMZ sulfone was carefully monitored. The optimized system consisted of 100 mM Tris‐phosphate buffer pH 2.5 with 20 mM 2‐hydroxypropyl‐β‐CD, 1 mM sodium dithionite, temperature at 15°C, voltage at 28 kV, and UV detection at 301 nm. Once optimized, the electrophoretic system was validated according to ICH guidelines. The limits of detection and quantification for R‐OMZ were 0.6 μg/mL (0.06% w/w of ESO) and 2.0 μg/mL (0.2% w/w of ESO), respectively. A mean concentration of R‐OMZ <0.2% limit established by the United States Pharmacopeia (USP) was found in the raw material and six‐pellet samples of ESO. No other impurities were found in the samples under these conditions. Therefore, the developed method was found to be appropriate not only for enantiomeric quality control of ESO but also for the analysis of ESO and the main related substance in raw material and pharmaceutical formulations as well as for stability indicating studies.     

Size does matter! Label-free detection of small molecule–protein interaction

This review is focused on methods for detecting small molecules and, in particular, the characterisation of their interaction with natural proteins (e.g. receptors, ion channels). Because there are intrinsic advantages to using label-free methods over labelled methods (e.g. fluorescence, radioactivity), this review only covers label-free techniques. We briefly discuss available techniques and their advantages and disadvantages, especially as related to investigating the interaction between small molecules and proteins. The reviewed techniques include well-known and widely used standard analytical methods (e.g. HPLC-MS, NMR, calorimetry, and X-ray diffraction), newer and more specialised analytical methods (e.g. biosensors), biological systems (e.g. cell lines and animal models), and in-silico approaches.