Determination of formaldehyde and cyanide ion in human nasal discharge by using simple spectrophotometric methods

Environmental tobacco smoke (ETS) contains many toxic compounds which include substances classified as aldehydes (e.g. formaldehyde) and inorganic substances such as cyanide ions. The information on the determination of these compounds in water is available, but the monitoring data on the level of these substances in human body fluids are still lacking. In this work the procedure for determining cyanide ions and formaldehyde in samples of human nasal discharge by simple spectrophotometric technique is presented.     

Spatially Resolved Kinetic Model of Parahydrogen Induced Polarisation (PHIP) in a Microfluidic Chip

We report a spatially resolved kinetic finite element model of parahydrogen-induced polarisation (PHIP) in a microfluidic chip that was calibrated using on-chip and off-chip NMR data. NMR spectroscopy has great potential as a read-out technique for lab-on-a-chip (LoC) devices, but is often limited by sensitivity. By integrating PHIP with a LoC device, a continuous stream of hyperpolarised material can be produced, and mass sensitivities of have been achieved. However, the yield and polarisation levels have so far been quite low, and can still be optimised. To facilitate this, a kinetic model of the reaction has been developed, and its rate constants have been calibrated using macroscopic kinetic measurements. The kinetic model was then coupled with a finite element model of the microfluidic chip. The model predicts the concentration of species involved in the reaction as a function of flow rate and position in the device. The results are in quantitative agreement with published experimental data.     

Suspension Fertilizers Based on Waste Phosphates from the Production of Polyols

Phosphorus raw materials are non-renewable, and their resources are shrinking faster and faster as a result of increased fertilizer production. This is due to the increasing population and the need to produce more food. Phosphorus, on the other hand, is one of the main nutrients of plants, without which it is impossible to conduct intensive agricultural production. There are no economically significant phosphate resources in Europe, so they must be imported. That is why it is so important to reduce losses and recover this element from waste streams, which was reflected in the new EU Regulation 2019/1009. A prospective option is to use waste phosphates from the production of polyether polyols. Previous studies show that they contain about 20% phosphorus. Due to their high water content, the most advantageous form of their application is the production of fertilizers in the form of a suspension. The aim of the study is to assess the possibility of using waste phosphates from the production of polyols as raw materials for the production of suspension fertilizers.     

Molecular Imaging of Biological Samples on Nanophotonic Laser Desorption Ionization Platforms

Mass spectrometry imaging (MSI) is a comprehensive tool for the analysis of a wide range of biomolecules. The mainstream method for molecular MSI is matrix‐assisted laser desorption ionization, however, the presence of a matrix results in spectral interferences and the suppression of some analyte ions. Herein we demonstrate a new matrix‐free MSI technique using nanophotonic ionization based on laser desorption ionization (LDI) from a highly uniform silicon nanopost array (NAPA). In mouse brain and kidney tissue sections, the distributions of over 80 putatively annotated molecular species are determined with 40 μm spatial resolution. Furthermore, NAPA‐LDI‐MS is used to selectively analyze metabolites and lipids from sparsely distributed algal cells and the lamellipodia of human hepatocytes. Our results open the door for matrix‐free MSI of tissue sections and small cell populations by nanophotonic ionization.     

Efficient S-alkylation of cysteine in the presence of 1,1,3,3-tetramethylguanidine

The synthesis of S-alkylated cysteine derivatives was carried out successfully in the presence of 1,1,3,3-tetramethylguanidine. Alkylation proceeded in high yields on unprotected amino acids and peptides containing a sulfhydryl group.     

Synthesis, crystal structure, and catalytic properties of MgCo6Ge6

The ternary compound MgCo6Ge6 represents a novel member of the RM6X6 phases, which contains a graphite-type Ge network, Kagomé nets of Co atoms, and Ge2 dumbbells with an unexpected short Ge-Ge contact in the range of a localized Ge-Ge single bond. The title compound shows a large variety of chemical bonding, which ranges from metallic to multicenter and covalent bonding. The role of polar intermetallic alloys as promising candidates for the application as catalysts for the selective hydrogenation of alpha,beta-unsaturated aldehydes is discussed. MgCo6Ge6 possesses a remarkable activity and selectivity for the hydrogenation of cis/trans-citral to geraniol and nerol.     

Exact and approximation methods for dependability assessment of tram systems with time window

The transportation system examined in this paper is the city tram one, where failed trams are replaced by reliable spare ones. If failed tram is repaired and delivered, then it comes back on work. There is the time window that failed tram has to be either replaced (exchanged) by spare or by repaired and delivered within. Time window is therefore paramount to user perception of transport system unreliability. Time between two subsequent failures, exchange time, and repair together with delivery time, respectively, are described by random variables A, E, and D. A/E/D is selected as the notation for these random variables. There is a finite number of spare trams. Delivery time does not depend on the number of repair facilities. Hence, repair and delivery process can be treated as one with infinite number of facilities. Undesirable event called hazard is the event: neither the replacement nor the delivery has been completed in the time window. The goal of the paper is to find the following relationships: hazard probability of the tram system and mean hazard time as functions of number of spare trams. For systems with exponential time between failures, Weibull exchange and exponential delivery (so M/W/M in the proposed notation) two accurate solutions have been found. For systems with Weibull time between failures with shape in the range from 0.9 to 1.1, Weibull exchange and exponential delivery (i.e. W/W/M) a method yielding small errors has been provided. For the most general and difficult case in which all the random variables conform to Weibull distribution (W/W/W) a method returning moderate errors has been given.