This paper presents the results of determination of selected characteristics (anions, cations, formaldehyde, hydrogen peroxide,
phenols, TC, TIC, TOC and metals) in dew samples collected in six different sites in Poland. The influence of local parameters
(e.g. wind speed, humidity) was investigated. Discriminant analysis was applied to the study of several dew samples collected from
different sampling sites covering six agglomerations in Poland. Discriminant function analysis was used not only for classifying
samples into different groups with a better than chance accuracy, but also for detecting the most important variables that
discern between the groups of samples considered. In this way it was possible to identify which ions or other physicochemical
features are responsible for the similarities or differences observed between different groups of dew samples. A good agreement
with their origin and location was observed. It is interesting to note that the classification of all samples was dominated
by pH, wind direction, pressure and temperature with a significant contribution of Na+ and Cl− ions.
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Lactobionic acid is a relatively new product derived from lactose oxidation, with high potential applications as a bioactive compound. Conducted experiments confirmed that both the time and temperature influenced the production of lactobionic acid during bioconversion of lactose using the Pseudomonas taetrolens bacteria. The study also investigated the effect of inoculum concentration on the production of lactobionic acid as a result of oxidation of whey-derived lactose. The highest concentration of lactobionic acid during oxidation of whey-derived lactose at a temperature of 30 °C by microorganisms. P. taetrolens was obtained during 50-h oxidation of the medium, which contained 25 % addition of the inoculum, in which the count of live cells was 2.85?×?109 CFU/ml. 相似文献
We study reflexivity of bilattices. Some examples of reflexive and non-reflexive bilattices are given. With a given subspace lattice ? we may associate a bilattice Σ?. Similarly, having a bilattice Σ we may construct a subspace lattice Σ?. Connections between reflexivity of subspace lattices and associated bilattices are investigated. It is also shown that the direct sum of any two bilattices is never reflexive. 相似文献
In this paper, we propose an approach to the flexural stiffness or eigenvalue frequency identification of a linear structure using a non-stationary stochastic excitation process. The idea of the proposed approach lies within time domain input-output methods. The proposed method is based on transforming the dynamical problem into a static one by integrating the input and the output signals. The output signal is the structure reaction, i.e. structure displacements due to the short-time, irregular load of random type. The systems with single and multiple degrees of freedom, as well as continuous systems are considered. 相似文献
4,4‐Dialkyl and 4,4‐diaryl‐4H‐benzo[d][1,3]oxathiin‐2‐ones were synthesized by the reaction of 2‐(mercapto‐phenyl)‐dialkyl‐ (or diaryl)‐methanol with CDI in excellent yield. The 2‐(mercaptophenyl)‐dialkyl‐ (or diaryl)‐methanols were prepared by the reaction of commercially available methylthiosalicylate with an appropriate alkyl or aryl Grignard reagent. 相似文献
Mass spectrometric imaging (MSI) in combination with electrospray mass spectrometry (ESI-MS) is a powerful technique for visualization and identification of a variety of different biomolecules directly from thin tissue sections. As commonly used tools for molecular reporting, fluorescent proteins are molecular reporter tools that have enabled the elucidation of a multitude of biological pathways and processes. To combine these two approaches, we have performed targeted MS analysis and MALDI-MSI visualization of a tandem dimer (td)Tomato red fluorescent protein, which was expressed exclusively in the hypoxic regions of a breast tumor xenograft model. For the first time, a fluorescent protein has been visualized by both optical microscopy and MALDI-MSI. Visualization of tdTomato by MALDI-MSI directly from breast tumor tissue sections will allow us to simultaneously detect and subsequently identify novel molecules present in hypoxic regions of the tumor. MS and MALDI-MSI of fluorescent proteins, as exemplified in our study, is useful for studies in which the advantages of MS and MSI will benefit from the combination with molecular approaches that use fluorescent proteins as reporters.
It is imperative to fascinate young children at an early stage in their education for the analytical sciences. The exposure of the public to mass spectrometry presently increases rapidly through the common media. Outreach activities can take advantage of this exposure and employ mass spectrometry as an exquisite example of an analytical science in which children can be fascinated. The presented teaching modules introduce children to mass spectrometry and give them the opportunity to experience a modern research laboratory. The modules are highly adaptable and can be applied to young children from the age of 6 to 14 y. In an interactive tour, the students explore three major scientific concepts related to mass spectrometry; the building blocks of matter, charged particle manipulation by electrostatic fields, and analyte identification by mass analysis. Also, the students carry out a mass spectrometry experiment and learn to interpret the resulting mass spectra. The multistage, inquiry-based tour contains flexible methods, which teach the students current-day research techniques and possible applications to real research topics. Besides the scientific concepts, laboratory safety and hygiene are stressed and the students are enthused for the analytical sciences by participating in “hands-on” work. The presented modules have repeatedly been successfully employed during laboratory open days. They are also found to be extremely suitable for (early) high school science classes during laboratory visit-focused field trips.
The synthesis, characterization, and the influence of single-walled carbon nanotubes (SWCNTs) modified with an anticancer drug doxorubicin (DOx) on the properties of model biological membrane as well as the comparison of the two modes of modification has been presented. The drug was covalently attached to the nanotubes either preferentially on the sides or at the ends of the nanotubes by the formation of hydrazone bond. The efficiency of the modification was proved by the results of FTIR, Raman, and thermogravimetric analysis. In order to characterize the influence of SWCNT-DOx conjugates on model biological membranes, Langmuir technique has been employed. The mixed monolayers composed of 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol (DPPTE) and SWCNT-DOx with different weight ratio have been prepared. It has been shown that changes in the isotherm characteristics depend on the SWCNTs content. While smaller amounts of SWCNTs do not exert significant differences, the introduction of the prevailing content of the nanotubes increases area per molecule and decreases the maximum value of compression modulus, leading to more fluid monolayer. However, upon increasing the surface pressure, the aggregation of carbon nanotubes within the thiolipid matrix has been observed. Mixed layers of DPPTE/SWCNT-DOx were also transferred onto gold electrodes by means of LB method. Cyclic voltammetry showed that SWCNT-DOx conjugates remain adsorbed at the electrode surface and are stable in time. Additionally, higher values of peak current and DOx surface concentration obtained for side modification prove that side modification allows for more efficient conjugation of the drug to carbon nanotubes.
