Analysis of the polydispersity of soil-like bodies in glacier environments by the laser light scattering (diffraction) method

This study presents the results of polydispersity analysis of soil-like bodies from two various polar regions using the laser light scattering method. The differences in the particle size distribution of cryoconite samples from the Anuchin Glacier (Antarctica) and the Mushketov Glacier (Arctic) are described. The samples obtained from the Mushketov Glacier are characterized by a finer particle size distribution than samples collected on the Anuchin Glacier. While comparing our results with previously published studies, it was found that the method of laser light scattering shows a lower content of small fractions (<0.05 mm) compared to the classical methods of sedimentation, since these methods are based on fundamentally different physical principles. The laser method used requires low amounts of samples (0.2–0.5 g), while the classical sedimentary method uses a higher gravimetric portion of cryoconite (5–10 g), which is critical for field sampling.

Characterisation, Chain Conformation and Antifatigue Effect of Steamed Ginseng Polysaccharides With Different Molecular Weight

Two polysaccharides were obtained from steamed ginseng via ultrafiltration, and their physical–chemical properties, solution properties and antifatigue activities were studied. WSGP-S3 and WSGP-G3 were acid heteropolysaccharides with the molecular weights of 2.03 × 104 and 4.86 × 104, respectively. They were composed of different molar ratios of the monosaccharides Rha, GlcA, GalA, Glc, Gal, and Ara. The results of size-exclusion chromatography–multiangle laser light scattering analysis, Conge red staining and Circular dichroism spectroscopy revealed that WSGP-S3 exhibited a random conformation of branched clusters in solution. By contrast, WSGP-G3 exhibited an ordered conformation, including helix-like conformations in aqueous solution. Antifatigue activity tests proved that WSGP-S3 markedly prolonged the exhaustive swimming time of fatigued mice; increased liver and muscle glycogen levels and superoxide dismutase, catalase, glutathione peroxidase activities and decreased blood lactic acid, nitrogen and malondialdehyde levels compared with the control treatment. Moreover, it enhanced spleen cell proliferation in fatigued mice. By contrast, WSGP-G3 had no significant effect on fatigued mice. The results showed that WSGP-S3 might have a major contribution to the antifatigue effects of steamed ginseng polysaccharides and could be a potential anti-fatigue polysaccharide.

Applying of Chitosan-TiO2 Nanocomposites for Photocatalytic Degradation of Anthracene and Pyrene

In this work, chitosan-TiO2 nanocomposites (NСs CS-TiO2) were developed for the photocatalytic degradation of some representatives of polycyclic aromatic hydrocarbons (PAHs). TiO2 nanoparticles (NPs) were synthesized by laser ablation method and their sizes were determined by dynamic laser light scattering (DLLS). Anthracene and pyrene in micellar solution were used as representatives of PAHs. The effect of TiO2 in the composition of prepared nanocomposites on the photodegradation of PAHs in model environments under UV irradiation was studied. The method of solid-phase luminescence (SPL) was used to estimate the decrease in PAHs concentrations. Based on the results of the studies carried out, pseudo-first order photodegradation kinetics were plotted. The efficiency of using the nanocomposites for the photocatalytic degradation of anthracene and pyrene was proved.