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The effects of a short (15 and 30 s) exposure of durum wheat (Triticum durum) seeds to extremely low frequency magnetic field (f = 50 Hz, B = 15 mT) on germination and seedling growth under controlled laboratory conditions were studied. Germination rate, fresh weight of seedlings, seedlings height and chlorophyll contents were measured the 4th and 8th day after sowing. Magnetic field did not influence the seed germination process. Fresh weight was affected by applied treatments in the first four days (118% and 89% of control plans for 15 s and 30 s treatment, respectively). In the further period, the action of magnetic field (MF) pre-treatment on growth of seedlings was eliminated, resulting in compensation of growth potentialities. The chlorophyll levels in seedlings were significantly modified, on both the 4th (120% and 87% of control plans for 15 s and 30 s treatment, respectively) and 8th (94% for 15 s treatment and 96% for 30 s) days. However, the chlorophyll a and b ratios remained unchanged after MF treatments. The results show that MF may have, a mostly temporary, negative and positive effect on early growth, which is strongly dependent on the applied exposure time.
The patch clamp measurements carried out on the patch of the cell membrane showed that amphotericin B (AmB) applied at a low concentration (0.05 and 0.1 µM) causes a decrease in seal resistance, indicating loss of membrane tightness. Application of AmB also decreased the number of active outward rectifying potassium channels TOK1, but did not change the unitary conductance of the channels. Interestingly, AmB did not significantly change the open probability of the single channel. Such results indicate a lack of direct interaction of AmB and the channels. Membrane permeability changes after AmB were also observed by fluorescent microscopy. This research allowed us to conclude that integrity of the membrane between the pores formed by AmB is maintained. Supported by NCN grant DEC-2012/05/BNZ1/00037
The aim of the present study was to analyse commercially available compounds containing nanoparticles in the form of Ag, Cu, and Ag sulphate colloids applied in agriculture. The compounds were analysed with TEM and FTIR spectroscopy, i.e., methods that can complement the commonly used research techniques such as EDX or Raman spectroscopy. The results of the microscopic examinations evidenced the presence of single spherical agglomerates (small granules) of the nanoparticle-containing products. Infrared spectroscopy revealed the presence of bands characteristic of vibrations that can be assigned to nanoparticle-X interactions, where X = S, C, or O in aqueous colloid solutions of the analysed samples. Additionally, bands characteristic for C-H stretching vibrations (probably associated with vibrations of the -CH₂ and -CH₃ groups) were observed as bands originating from compounds used as the carriers of the analysed systems. In the case of Ag sulphate, the most distinct band with a maximum at 2,863 cm⁻¹, which is characteristic of SH···Ag vibrations, can be observed, and its intensity may be associated with the nanostructure composition of the formulation, which is more diverse than that in the other two compounds.
Amphotericin B (AmB) is a polyene antibiotic frequently applied in the treatment of fungal infections. According to the general understanding, the mode of action of AmB is directly related to the molecular organization of the drug in the lipid environment, in particular to the formation of pore-like molecular aggregates. Electronic absorption and fluorescence techniques were applied to investigate formation of molecular aggregates of AmB in the lipid environment of liposomes and monomolecular layers formed at the argon-water interface. It appears that AmB dimers, stabilized by van der Waals interactions, are present in the membrane environment along with the aggregates formed by a greater number of molecules. Linear dichroism measurements reveal that AmB is distributed between two fractions of molecules, differently oriented with respect to the bilayer. Molecules in one fraction remain parallel to the plane of the membrane and molecules in the other one are perpendicular. Scanning Force Microscopy imaging of the surface topography of the monolayers formed with AmB in the presence of lipids reveals formation of pore-like structures characterized by the external diameter close to 17 Å and the internal diameter close to 6 Å. All the findings are discussed in terms of importance of the molecular organization of AmB in the pharmacological action, as well as of the toxic side effects of the drug.
Biodiesel is a very attractive, biodegradable, renewable, and virtually nontoxic form of fuel. It is derived through base-catalysed transesterification of vegetable oils or animal fats. Analysis of biodiesel has become relevant, since the higher quality of the fuel is a key factor in commercialisation and market acceptance. The analytical methods employed are being constantly improved to meet this requirement. The most popular techniques for analysis of biodiesel include mainly chromatography and molecular spectroscopy. FTIR infrared spectroscopy is one of the most important spectroscopic techniques. The article presents the results of UV-Vis absorption spectroscopy and FTIR infrared spectroscopy analysis employed for investigating methyl esters of higher fatty acids obtained with laboratory methods from selected sunflower and rapeseed oils and waste animal fats provided by a slaughterhouse. Commercial methyl esters were included in the analyses for comparison. In all samples, the contents of free glycerol, methanol, esters, and linolenic acid methyl ester in FAME were determined mainly to facilitate the spectroscopic analysis. The results of the investigations conducted with the aforementioned methods clearly indicate that the analysed WCO esters can be successfully used as potential industrial-scale biofuels.
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