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Glasses containing two different network-forming components and doped with optically active ions exhibit interesting properties. In this work, glass systems based on germanium dioxide and boron trioxide singly doped with lanthanides (Eu3+) and transition metals (Cr3+) ions are research subjects. Optical spectroscopy was the major research tool used to record excitation and emission spectra in a wide spectral range for studied systems. The emitted radiation of glasses doped with Cr3+ ions is dominated by broadband luminescence centered at 770 nm and 1050 nm (4T2 → 4A2). Interestingly, the increase of concentration of one of the oxides contributed to the detectable changes of the R-line (2E → 4A2) of Cr3+ ions. Moreover, EPR spectroscopy confirmed the paramagnetic properties of the obtained glasses. The influence of molar ratio GeO2:B2O3 on spectroscopic properties for Eu3+ ions is discussed. The intensity of luminescence bands due to transitions of trivalent europium ions as well as the ratio R/O decrease with the increase of B2O3. On the other hand, the increase in concentration B2O3 influences the increasing tendency of luminescence lifetimes for the 5D0 state of Eu3+ ions. The results will contribute to a better understanding of the role of the glass host and thus the prospects for new optical materials.

Clonally related B cells infiltrate the brain, meninges, and cerebrospinal fluid of MS patients, but the mechanisms driving the B-cell response and shaping the immunoglobulin repertoires remain unclear. Here, we used single-cell full-length RNA-seq and BCR reconstruction to simultaneously assess the phenotypes, isotypes, constant region polymorphisms, and the paired heavy- and light-chain repertoires in intrathecal B cells. We detected extensive clonal connections between the memory B cell and antibody-secreting cell (ASC) compartments and observed clonally related cells of different isotypes including IgM/IgG1, IgG1/IgA1, IgG1/IgG2, and IgM/IgA1. There was a strong dominance of the G1m1 allotype constant region polymorphisms in ASCs, but not in memory B cells. Tightly linked to the G1m1 allotype, we found a preferential pairing of the immunoglobulin heavy-chain variable (IGHV)4 gene family with the κ variable (IGKV)1 gene family. The IGHV4-39 gene was most used and showed the highest frequency of pairing with IGKV1-5 and IGKV1(D)-33. These results link IgG constant region polymorphisms to stereotyped B-cell responses in MS and indicate that the intrathecal B-cell response in these patients could be directed against structurally similar epitopes.

Glasses containing two different network-forming components and doped with optically active ions exhibit interesting properties. In this work, glass systems based on germanium dioxide and boron trioxide singly doped with lanthanides (Eu3+) and transition metals (Cr3+) ions are research subjects. Optical spectroscopy was the major research tool used to record excitation and emission spectra in a wide spectral range for studied systems. The emitted radiation of glasses doped with Cr3+ ions is dominated by broadband luminescence centered at 770 nm and 1050 nm (4T2 → 4A2). Interestingly, the increase of concentration of one of the oxides contributed to the detectable changes of the R-line (2E → 4A2) of Cr3+ ions. Moreover, EPR spectroscopy confirmed the paramagnetic properties of the obtained glasses. The influence of molar ratio GeO2:B2O3 on spectroscopic properties for Eu3+ ions is discussed. The intensity of luminescence bands due to transitions of trivalent europium ions as well as the ratio R/O decrease with the increase of B2O3. On the other hand, the increase in concentration B2O3 influences the increasing tendency of luminescence lifetimes for the 5D0 state of Eu3+ ions. The results will contribute to a better understanding of the role of the glass host and thus the prospects for new optical materials.

Recent interest in the antioxidant capacity of foods and beverages is based on the established medical knowledge that antioxidants play an essential role in counteracting the damaging effects of free radicals, preventing human neurodegenerative diseases, cardiovascular disorders, and even cancer. At the same time, there is no “the method" that uniquely defines the antioxidant capacity of substances; moreover, the question of interrelation between results obtained by different experimental techniques is still open. In this work, we consider the trolox equivalent antioxidant capacity (TEAC) values obtained by electron paramagnetic resonance (EPR) spectroscopy and ultraviolet–visible (UV–vis) spectroscopy using the classic objects for such studies as an example: red, rosé, and white wine samples. Based on entirely different physical principles, these two methods give values that are not so simply interrelated; this creates a demand for machine learning as a suitable tool for revealing quantitative correspondence between them. The consideration consists of an approximate correlation-based analytical model for the key argument (i.e., TEACEPR) with subsequent adjustment by machine learning-based processing utilizing the CatBoost algorithm with the usage of auxiliary chemical data, such as the total phenolic content and color index, which cannot be accurately described by analytical expressions.

Clonally related B cells infiltrate the brain, meninges and cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients, but the mechanisms driving the B-cell response and shaping the immunoglobulin repertoires remain unclear. Here, we used single-cell full-length RNA-seq and B-cell receptor reconstruction to simultaneously assess the phenotypes, isotypes, constant region polymorphisms, and the paired heavy- and light-chain repertoires in intrathecal B-lineage cells. We detected extensive clonal connections between the memory B cell and antibody-secreting cell (ASC) compartments and observed clonally related cells of different isotypes, including IgM/IgG1, IgG1/IgA1, IgG1/IgG2, and IgM/IgA1. There was a strong dominance of the G1m1 allotype constant region polymorphisms in ASCs, but not in memory B cells. Tightly linked to the G1m1 allotype, we found a preferential pairing of theIGHV4gene family with the κ variable(IGKV)1gene family. These results link IgG constant region polymorphisms to stereotyped B-cell responses in MS, indicating that the intrathecal B-cell response in these patients could be directed against structurally similar epitopes. The data also suggest that the dominance of the G1m1 allotype in ASCs may occur as a result of biased differentiation of intrathecal memory B cells.

Single-cell analysis reveals an accumulation of short-lived disease-specific as well as non–disease-specific intestinal plasma cells in untreated and short-term–treated celiac disease. Plasma cells differ transcriptionally depending on specificity, longevity, and disease status and may contribute to formation of the celiac lesion., Disease-specific plasma cells (PCs) reactive with transglutaminase 2 (TG2) or deamidated gluten peptides (DGPs) are abundant in celiac disease (CeD) gut lesions. Their contribution toward CeD pathogenesis is unclear. We assessed expression of markers associated with PC longevity in 15 untreated and 26 treated CeD patients in addition to 13 non-CeD controls and performed RNA sequencing with clonal inference and transcriptomic analysis of 3,251 single PCs. We observed antigen-dependent V-gene selection and stereotypic antibodies. Generation of recombinant DGP-specific antibodies revealed a key role of a heavy chain residue that displays polymorphism, suggesting that immunoglobulin gene polymorphisms may influence CeD-specific antibody responses. We identified transcriptional differences between CeD-specific and non–disease-specific PCs and between short-lived and long-lived PCs. The short-lived CD19+CD45+ phenotype dominated in untreated and short-term–treated CeD, in particular among disease-specific PCs but also in the general PC population. Thus, the disease lesion of untreated CeD is characterized by massive accumulation of short-lived PCs that are not only directed against disease-specific antigens., Graphical Abstract

Novel multicomponent titanate-germanate glasses singly doped with transition metal (Cr3+) and rare earth ions (Eu3+) were synthesized and the glass transition temperatures and thermal stability parameters were determined using DSC measurements. X-ray diffraction analysis confirmed fully amorphous nature of the received samples. Their structural and optical properties were compared with germanate glasses without TiO2. Correlation between local structure and optical properties in titanate-germanate glasses is well evidenced by FT-IR, Raman, EPR, and luminescence spectroscopy. In particular, luminescence spectra and their decays are examined for glass samples, where GeO2 was partially substituted by TiO2.

A new equation for converting EC50 into TEAC values and TEAC into EC50 is presented in this paper. The model was fitted to 180 data points of electron paramagnetic resonance (EPR) spectroscopy measurements of various food products. The model was tested basing on 75 EPR spectroscopy measurements. Moreover, the equation was tested on literature data. The determination coefficient between EC50cal and EC50exp was found to be R2 = 0.9762, while the determination coefficient between TEACcal and TEACexp was found to be R2 = 0.9686. Based on obtained results it can be concluded that the proposed model for converting EC50 into TEAC values and TEAC into EC50 values works properly. This will enable a comparison of the antioxidant properties of products identified in literature through the use of different parameters (TEAC, EC50).

The antioxidant properties of different types of tea—green, black and earl grey—were investigated using the EPR spectroscopy method based on a new semi-empirical mathematical model and on a single EPR spectroscopy measurement. The obtained values of the antioxidant capacity were correlated with the bioactive ingredient content identified through the NMR spectroscopy. Moreover, an attempt was made to determine what impact on the antioxidant properties of tea does adding sugar, milk, lemon and honey have. All studied teas exhibited antioxidant properties. The best DPPH free radical scavengers were green teas. Adding sugar, milk and lemon juice to tea did not significantly impact the antioxidant properties of the infusion; adding honey, however, caused an increase in the total antioxidant capacity of the infusion. The aromatic proton content correlates positively with the antioxidant capacity value.

Presented here is a comprehensive study on the antioxidant properties of various alcoholic beverages: beers, wines, tinctures, and strong spirits, including whisky, brandy, cognac, vodkas, and liquors. The Trolox equivalent antioxidant capacity (TEAC) of each of these various alcoholic beverages is determined using an electron paramagnetic resonance (EPR) method, which is based on a semiempirical correlation. Moreover, the EC50 parameter was determined on the basis of the dependences of the TEAC values obtained by this mathematical equation. Moreover, the total phenolic content (TP) and color index, which have a direct influence on the antioxidant properties of the alcoholic beverages, were identified. The results showed that all the investigated alcoholic beverages (ABs), with the exception for vodkas, exhibit antioxidant properties. By performing a statistical analysis, it was found that the TEAC value significantly depends on the TP, production method, and raw material from which the alcohol was made. However, it is assumed that the TEAC value of alcoholic beverages is independent of the alcohol content.

The protein p53 protects the organism against carcinogenic events by the induction of cell cycle arrest and DNA repair program upon DNA damage. Virtually all cancers inactivate p53 either by mutations/deletions of the TP53 gene or by boosting negative regulation of p53 activity. The overexpression of MDM2 protein is one of the most common mechanisms utilized by p53wt cancers to keep p53 inactive. Inhibition of MDM2 action by its antagonists has proved its anticancer potential in vitro and is now tested in clinical trials. However, the prolonged treatment of p53wt cells with MDM2 antagonists leads to the development of secondary resistance, as shown first for Nutlin-3a, and later for three other small molecules. In the present study, we show that secondary resistance occurs also after treatment of p53wt cells with idasanutlin (RG7388, RO5503781), which is the only MDM2 antagonist that has passed phase II and entered phase III clinical trials, so far. Idasanutlin strongly activates p53, as evidenced by the induction of p21 expression and potent cell cycle arrest in all the three cell lines tested, i.e., MCF-7, U-2 OS, and SJSA-1. Notably, apoptosis was induced only in SJSA-1 cells, while MCF-7 and U-2 OS cells were able to restore the proliferation upon the removal of idasanutlin. Moreover, idasanutlin-treated U-2 OS cells could be cultured for long time periods in the presence of the drug. This prolonged treatment led to the generation of p53-mutated resistant cell populations. This resistance was generated de novo, as evidenced by the utilization of monoclonal U-2 OS subpopulations. Thus, although idasanutlin presents much improved activities compared to its precursor, it displays the similar weaknesses, which are limited elimination of cancer cells and the generation of p53-mutated drug-resistant subpopulations.

Antioxidant properties of selected herbs were investigated using electron paramagnetic resonance (EPR) spectroscopy. This was possible by measuring changes in the intensity of the EPR spectrum that resulted from the interaction of the stable radical 1,1-diphenyl-2-picrylhydrazyl with antioxidants found in herbal samples. Moreover, the total phenolic content (TPC) was measured using UV-Vis spectroscopy. The values of trolox equivalent antioxidant capacity were in the range of 10.95 to 505.95 μmol Trolox/1 g of dry weight of sample. TPC values were in the range of 3.38 to 63.13 mg of gallic acid/1 g of dry weight. The results showed that all of the investigated herbs exhibit antioxidant properties. A positive and significant correlation between antioxidant activity and total phenolic content was observed. The studied herbs could be a good source of natural antioxidants.

The antioxidant properties of various kinds of the traditional Polish alcoholic beverage nalewka were investigated using electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR) and ultraviolet–visible (UV–vis) spectroscopy. The antioxidant capacity was measured by EPR spectroscopy in μmol Trolox (TE) in a 100 mL nalewka sample. The total phenolic content was measured by Folin–Ciocalteu (FC) assays while aromatic proton content ( H ar ) was determined by NMR spectroscopy; subsequently the correlation among these values was explored. All of the investigated nalewkas exhibited antioxidant properties. The values of Trolox equivalent antioxidant capacity (TEAC DPPH ) were in the range 45–1045 μmol TE/100 mL. It was found that the value of the TEAC DPPH corresponded to the TP ( r = 0.96) and H ar ( r = 0.95). Moreover, the TEAC DPPH values depended on the kinds of fruits used for nalewkas’ preparation.

Background B cells may contribute to the immunopathogenesis of multiple sclerosis (MS). Dimethyl fumarate (DMF) has recently been shown to reduce the frequency of memory B cells in blood, but it is not known whether the drug influences the cellular composition in the cerebrospinal fluid (CSF). Methods A cross-sectional study examining the cellular composition in blood and cerebrospinal fluid (CSF) from 10 patients treated with DMF and 18 patients receiving other disease modifying drugs or no treatment. Results Patients treated with DMF had reduced proportions of memory B cells in blood compared to other MS patients ( p = 0.0007), and the reduction correlated with treatment duration ( r s = −0.75, p = 0.021). In the CSF, the absolute number of mononuclear cells were significantly lower in DMF-treated patients compared to the other patients ( p = 0.023), and there was a disproportionate decrease of plasmablasts ( p = 0.031). Conclusion The results of this exploratory study support a B-cell mediated mechanism of action for DMF in both blood and CSF.

A new equation for converting EC

The antioxidant properties of various kinds of beers were investigated using electron paramagnetic resonance (EPR) spectroscopy. This was possible by measuring the changes in the intensity of the EPR spectrum that resulted from the interaction of the stable radical DPPH (1,1-diphenyl-2-picrylhydrazyl) with the antioxidants found in a beer sample. The antioxidant capacity was then presented in Trolox Equivalents, e.g. μM trolox in a beer sample of 100 ml. The influence of the type, colour, the content of the extract and alcohol on the antioxidant activities of commercial beer samples was investigated using two-way hierarchical clustering and analysis of variance. The results showed that all of the beers investigated exhibit antioxidant properties. By performing an analysis of variance, it was found that the value of the antioxidant capacity significantly (0.05 level of significance) depends on the content of the extract and the colour of the beer. It seems that additives also influence the antioxidant properties to some extent, but neither the alcohol content nor the kind of fermentation affects the antioxidant properties of beer.

The occurrence of Total P (P-Tot) and the mineral forms of P (P-Min) in sediments from Goczalkowice Reservoir were investigated using inductively coupled plasma-optical emission spectrometer (ICP-OES). The method is based on sequential extractions of the sediment samples, each releasing four forms of inorganic P: loosely bound P, P bound to Al (P-Al), P bound to Fe (P-Fe) and P bound to Ca (P-Ca). Sediment samples for studies presented in this work were collected in April, August and November of 2009 from four sites of the Goczalkowice Reservoir. Significant variations in the P forms with sediment grain size were observed. The most abundant form of inorganic P in the bottom sediment was P-Fe. Other P forms were as follows: P-Ca > P-Al > loosely bound-P. Moreover, P compounds were studied using 31 P NMR. It was found that the predominant form was inorganic orthophosphate.

The antioxidant properties of samples of different kinds of commercially available alcoholic beverages were investigated by electron paramagnetic resonance (EPR) spectroscopy. This analytical technique is chiefly designed to enable accurate detection of free radicals. The determination of antioxidant activity by the EPR method is conducted by measuring the changes of the intensity of the EPR spectrum of stable radicals, which results from their interaction with antioxidants. Antioxidant capacity of alcoholic beverages samples was assessed with the use of the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH ). The highest antioxidant activity was found in red wines, followed by a blend of wine and brandy and then by whiskies, whereas plain vodkas and gin showed negative values of antioxidant activity. From our studies it can be concluded that the value of antioxidant capacity depends on the polyphenolic content, the time and method of ageing, as well as on the flavour and colour additives.

Goczalkowice Reservoir is the biggest water reservoir in the south of Poland. For our studies bottom sediments were collected from eight different places of the reservoir at various seasons of the year. EPR spectroscopy was applied to analyse both quantitatively and qualitatively the humic acids (HA) present in the samples. EPR spectra of the extracted HA exhibited broad lines from the paramagnetic metal ions and narrow lines from free radicals. The values of the free radical concentration obtained for HA amounted to 1.14–13.6 × 1016 spin g −1 depending on the season and the place of sample collection. The values of the g factor obtained for HA were of the range 2.0027–2.0035. The EPR studies show that HA extracted from bottom sediment collected at various points of the Goczalkowice Reservoir exhibit similar physical–chemical properties. It was also observed that the depth of the reservoir affects the content of the oxygen functional groups as well as the free radical concentration in HA. The identification of the functional groups was done by means of IR. UV/VIS spectroscopy was used to estimate the maturity of the HA.

The course of the humification process of sewage sludge collected from three biologic-mechanical treatment plants with different treatment technologies was studied. The maturity of sewage sludge and its usefulness for agricultural purposes was also discussed. The physical-chemical properties of humic acids extracted from sewage sludge received from comparable stages of sludge purification were described. Changes of the sludge properties during sewage purification and the progress of the humification process were investigated with EPR, IR and UV/VIS spectroscopic methods. The content of the elements and the carboxylic groups in humic acids extracted from each stage of the sewage treatment were also determined. It was found that the humification processes take place in all three treatment plants but with different intensities resulting from the differences in the individual cleaning processes in these plants. The most intensive changes of physical-chemical parameters in the extracted humic acids were observed in the anaerobic digester where mesophilic fermentation occurs. The sludge oxygenation processes also significantly affect the course of the humification process during sewage treatment.

Comparison of the physico-chemical properties was carried out for humic acids extracted from sewage sludge and bottom sediments. The isolated humic acids were investigated by means of EPR, IR, UV/vis spectroscopic methods and elementary analysis AE. On the basis of earlier studies it was stated that humic acids extracted from sewage sludge can be divided into humic acids extracted from raw sewage sludge and from sewage sludge after the digestion process. The digestion process was found to have the most significant effect on the physico-chemical properties of humic acids extracted from sludge during sewage treatment. Humic acids extracted from sewage sludge had higher free radical concentration than humic acid extracted from bottom sediments. Values of the g -factor were similar for all studied samples. However, it is noteworthy that g -factor values for humic acid extracted from raw sewage sludge and from bottom sediments were lower in comparison to the humic acid extracted from sewage sludge after the fermentation processes. The IR spectra of all studied humic acids confirmed the presence of functional groups characteristic for humic substances. It was also observed that humic acids extracted from bottom sediments had a more aromatic character and contained less carbon, nitrogen and hydrogen than those extracted from the sewage sludge.

In 2005 the treatment plant in Sosnowiec Zagorze was modernized and the processes of nitrification and denitrification were introduced. The study of the biological treatment influence on the course of the humification process was conducted for the sewage sludge received from each stage of sewage purification. The extracted humic-like substances (HA) were investigated by the use of the spectroscopic and analytical methods. The concentration of free radicals and the g -factor was determined with EPR, the presence of the characteristic functional groups was confirmed with IR spectroscopy, whereas the aromatisation of HA was estimated by 13 C NMR method. The results obtained were compared with those for HA extracted from sewage sludge before modernization [1] . It was found that the processes of biological treatment have a significant influence on the changes of the chemical elements in the extracted HA. The HA obtained after modernization are nitrogen-rich (about 9%), in particular after the nitrification and denitrification processes. However, nitrification and denitrification processes only slightly affect the free radical concentration and the g -factor values.

This study presents the results of comparative evaluation of the antioxidant activity of the phenolic fraction exhaustively extracted with aqueous methanol from 18 different thyme (Thymus L.) specimens and species. This evaluation is made with use of the same free radical source (DPPH• radical), three different free radical scavenging models (gallic acid, ascorbic acid, and Trolox), and three different measuring techniques (the dot blot test, UV-Vis spectrophotometry, and electron paramagnetic resonance spectroscopy, EPR). A comparison of the equivalence of these three different measuring techniques (performed with use of hierarchical clustering with Euclidean distance as a similarity measure and Ward's linkage) is particularly important in view of the fact that different laboratories use different antioxidant activity measuring techniques, which makes any interlaboratory comparison hardly possible. The results obtained confirm a semiquantitative equivalence among the three compared methodologies, and a proposal is made of a simple and cost-effective dot blot test that uses the DPPH• radical and provides differentiation of antioxidant activity of herbal matter comparable with the results of the UV-Vis spectrophotometry and EPR.

A new method of determining antioxidant capacity based on a mathematical model is presented in this paper. The model was fitted to 1000 data points of electron paramagnetic resonance (EPR) spectroscopy measurements of various food product samples such as tea, wine, juice, and herbs with Trolox equivalent antioxidant capacity (TEAC) values from 20 to 2000 μmol TE/100 mL. The proposed mathematical equation allows for a determination of TEAC of food products based on a single EPR spectroscopy measurement. The model was tested on the basis of 80 EPR spectroscopy measurements of herbs, tea, coffee, and juice samples. The proposed model works for both strong and weak antioxidants (TEAC values from 21 to 2347 μmol TE/100 mL). The determination coefficient between TEAC values obtained experimentally and TEAC values calculated with proposed mathematical equation was found to be R(2) = 0.98. Therefore, the proposed new method of TEAC determination based on a mathematical model is a good alternative to the standard EPR method due to its being fast, accurate, inexpensive, and simple to perform.

The differences in the Trolox Equivalent Antioxidant Capacity (TEAC) values at the same incubation time obtained by two different techniques: electron paramagnetic resonance (EPR) spectroscopy and ultraviolet visible (UV-vis) spectroscopy, which use the same antioxidant-free radical reaction mechanism, were determined for fruit juices, nectars and drinks. For this study, the stable free radical 1,1-Diphenyl-2-picryl-hydrazyl (DPPH(•)) was used. The antioxidant capacity was presented in Trolox Equivalents, e.g., μM trolox per 100 ml of sample. All of the studied fruit juices, drinks and nectars showed antioxidative properties. Dependencies between TEAC values and the percent fruit content and sample color were observed for the studied beverages. It was found that EPR spectroscopy is the more adequate method for determining TEAC values for these kinds of samples.

The humic acids extracted from sludge collected from the digestion chamber and the sludge drying beds were studied. The sludge samples were collected, dried and humic acids were extracted. The progress of the humification processes was studied with EPR, IR and NMR spectroscopic methods. For extracted humic acids, concentration of free radicals and g factor was determined with EPR. The presence of characteristic functional groups was confirmed with IR and NMR spectroscopy. To study the changes in content of the elements, the elemental analysis was performed to determine the percentage of carbon, hydrogen, nitrogen, sulfur and oxygen. Taking all the obtained results into account it was found that on the sewage drying beds, humification processes take place in the sludge. In the first two weeks when the sludge on the drying beds an intensive enrichment of humic acids in free radicals takes place. This is the result of the intensive humification process course after the stage in the fermentation chamber where the mesophilic fermentation takes place. Moreover, the humidity of sludge influences the intensive development of free radical concentration at the beginning of the storing period, whereas the humification processes still continue.

Derivatives of (E)-1-(5-alkoxybenzo[d][1,3]oxathiol-6-yl)-3-phenylprop-2-en-1-one (1) demonstrated exceptionally high in vitro cytotoxic activity, with IC50 values of the most active derivatives in the nanomolar range. To identify structural fragments necessary for the activity, several analogs deprived of selected fragments were prepared, and their cytotoxic activity was tested. It was found that the activity depends on combined effects of (i) the heterocyclic ring, (ii) the alkoxy group at position 5 of the benzoxathiole ring, and (iii) the substituents in the phenyl ring B. Replacement of the sulfur atom by oxygen does not influence the activity. None of the listed structural fragments alone assured high cytotoxic activity.

Humic acids, extracted from sludge at the biologic–mechanical sewage treatment plant in Jastrzebie Zdroj, have been investigated by means of 1 H, 13 C and 31 P NMR spectroscopy. Sludge samples for studies were taken from the primary settling tank, the nitrification chamber, the digestion chamber and the sludge drying beds. The 1 H NMR analysis of humic acid extracted from sludge at various stages of sewage treatment confirmed the presence of the functional groups that are characteristic for humic substances, and the analysis showed changes in their relative intensities. The 13 C NMR indicated that the aromatisation of the humic acid increased during sewage treatment. Moreover, the analysis of the 31 P NMR spectra allowed us to observe the changes in the phosphorus groups of the studied humic acids.

The aim of the present work was to compare the concentration changes of polyaromatic hydrocarbons (PAH) and the course of humification processes during wastewater treatment. Studies of samples from a biological-mechanical wastewater treatment plant in Sosnowiec-Zagorze (Poland) were carried out. Determination of PAH was performed both for wastewater sludge and sludge water. Observations of the course of humification processes for humic acid fractions isolated from sludges were conducted. Analysis of PAH extracted from wastewaters and from sludge was performed by means of high-performance liquid chromatography. Investigations of humification processes were conducted by electron paramagnetic resonance and nuclear magnetic resonance methods. The elementary composition changes in the structure of the extracted humic acids were determined. It was found that polyaromatic hydrocarbons appear during the processes of humification. Their content in water decreased only after the process of sludge aeration; however, sludge water leaving the settlers was PAH-enriched.