Ciliates from the faeces of the free-ranging dromedary from Oman: Morphology and molecular phylogeny.

Ciliates Infundibulorium cameli from the faeces of the free-ranging dromedary from Oman were studied using a set of methods of the light and immunofluorescence microscopy and molecular phylogeny. With the use of molecular genetic methods, it was confirmed that the cysts found in the samples simultaneously with trophozoites actually belong to the species I. cameli. Tubulin cytoskeleton organization of trophozoites and cysts of this species were described for the first time. A striking morphological similarity between species I. cameli and Buxtonella sulcata was demonstrated, including the organization of ciliature. Different isolates of I. cameli and B. sulcata formed a common clade on the phylogenetic tree. The level of evolutionary divergence between the 18 S rRNA sequences of I. cameli, B. sulcata and species closest to them according to the results of molecular phylogenetic analysis was estimated. It was demonstrated that the divergence between I. cameli and B. sulcata is extremely low compared to members of other genera included in the analysis. Taxonomic position of I. cameli and B. sulcata was discussed in according to the data of comparative morphology and molecular phylogeny.

Realization of Microfluidic Preconcentrator for N-Pentane Traces Impurities from the Gaseous Media.

In this paper, we present the work of designing and fabricating a new generation of microelectromechanical systems (MEMS) based microfluidic preconcentrators (MFP) for volatile organic compounds (VOCs) quantification. The main objective of this work is to quantify the n-pentane impurities using MFP for sample preparation. The MFP was analyzed using Hewlett-Packard 5890 gas chromatography, having a flame ionization detector under isothermal conditions. The proposed MFP system includes two-microfluidic preconcentrators for continuous action and a system of four 3/2 solenoid valves with a control unit. Microfluidic preconcentrators were placed on metal plates and have circular channels filled with Al2O3 (50 µm), n-octane ResSil-C (80/100 mesh) sorbents of one nature and are hyphenated with the Peltier elements to regulate the temperature of sorption and desorption. The n-pentane quantitative determination was carried out using a calibration plot of gas mixtures on a successive dilution with the nitrogen. This study shows that the microfluidic preconcentrator system with Al2O3 and n-Octane ResSil-C sorbent concentrates the n-pentane traces up to 41 to 47 times from the gas mixture with the standard deviation of ≤5%. It has been observed that the n-octane ResSil-C based MFC shows very fast response (<5 min) and stability up to 300 cycles.

A Study of the Physical and Mechanical Properties of Aerogels Obtained from Bacterial Cellulose.

Aerogels with a density of 4.2-22.8 kg/m3 were obtained from bacterial cellulose synthesized under static and dynamic cultivation conditions on a molasses medium. The strength properties and porous structure of the aerogels strongly depended on their density. With an aerogel density of 22.8 kg/m3, the modulus of elasticity at 80% compression of the sample was 0.1 MPa. The decrease in the density of aerogels led to an increase in the pore sizes ranging from 20 to 1000 µm and a decrease in the modulus of elasticity. These characteristics were more pronounced in aerogels obtained from bacterial cellulose under static cultivation conditions. The aerogels had a low coefficient of thermal conductivity (0.0257 W m-1 °C-1), which is comparable to the thermal conductivity of air, and moderate thermal stability because the degradation processes of the aerogels began at 237 °C. The aerogels obtained from bacterial cellulose had high sound absorption coefficients in the frequency range of 200-5000 Hz, which makes it possible to use the aerogels as heat- and sound-insulating materials.