Polycyclic aromatic hydrocarbon (PAH) phytoaccumulation in urban areas by Platanus × acerifolia, Celtis australis, and Tilia grandifolia leaves and branches

Polycyclic aromatic hydrocarbon (PAH) concentrations in the leaves and 1-year-old branches of three common tree species growing in a middle-sized city located in a moderate climate zone were estimated. For this purpose, PAH phytoaccumulation in Platanus × acerifolia, Celtis australis, and Tilia grandifolia species from highly urbanized, traffic congested, and highly PAH-contaminated streets was compared with trees from non-contaminated parks in the same urban core. The gathered data was used to define 17 PAH profiles, identify the main PAH pollution emission sources, and determine the organ and species specificity of PAHs accumulation. Due to the direct absorption of polluted air via stomata, the leaves accumulated up to 30% more PAHs compared to the 1-year-old branches. As expected, PAH concentrations were much higher in street trees, while heavy weight PAHs (with five and six rings) were accumulated in the highest concentrations. The highest foliar Σ17 PAH concentrations were detected in street-grown C. australis, followed by P. acerifolia and T. grandifolia (502.68, 488.45, and 339.47 ng g-1 dry weight (DW), respectively). The same pattern was noted for Σ17 PAHs in branches (414.89, 327.58, and 342.99 ng g-1 DW, respectively). Thus, T. grandifolia emerged as the least effective PAH sink as it accumulated up to ~ 40% less PAHs than P. acerifolia and C. australis leaves/branches. Among the 17 tracked PAHs, benzo[a]anthracene, benzo[a]pyrene, dibenzo[a,h]anthracene, and pyrene were found to have accumulated in the highest concentrations in all analyzed species irrespective of the site, and accounted for more than 50% of the total detected PAHs. Finally, a "black box" about species and organ specificity, as well as specific drivers that limit PAHs uptake capacity by trees, was opened, while this work provides insights into further PAH phytoremediation strategies.

Antioxidant proficiency in Serbian mushrooms: a comparative study on Hydnum repandum L. 1753 from mycorrhizal and edible niches

This study aimed to evaluate the antioxidant potential of autochthonous Hydnum repandum through LC-MS/MS profiling, total phenolic content (TP), total protein content (TPR), and antioxidant capabilities (DPPH, ABTS, and FRAP assays) across various extracts (CHCl3, acetone, 70% EtOH, 80% MeOH, and hot water). LC-MS/MS analysis revealed a predominant presence of quinic acid in polar solvents (ranging from 531.37 to 676.07 ng/mL), while EtOH and MeOH extracts exhibited elevated total phenolic levels (27.44 ± 0.32 and 28.29 ± 3.62 mg GAE/g d.w., respectively). Impressively, H. repandum showcased remarkable antioxidant properties, as evidenced by its FRAP values (57.29 to 199.96 mg AAE/g d.w.), ABTS values (5.69 to 29.95 mg TE/g d.w.), and IC50 values in the DPPH assay (91.40 to 372.55 μg/mL), which exhibited a strong correlation with TP. Notably, the acetone extract exhibited the most robust antioxidant activity where the highest TPR was observed, suggesting synergism of primary and secondary metabolites.

Incorporating high-resolution climate, remote sensing and topographic data to map annual forest growth in central and eastern Europe

To enhance our understanding of forest carbon sequestration, climate change mitigation and drought impact on forest ecosystems, the availability of high-resolution annual forest growth maps based on tree-ring width (TRW) would provide a significant advancement to the field. Site-specific characteristics, which can be approximated by high-resolution Earth observation by satellites (EOS), emerge as crucial drivers of forest growth, influencing how climate translates into tree growth. EOS provides information on surface reflectance related to forest characteristics and thus can potentially improve the accuracy of forest growth models based on TRW. Through the modelling of TRW using EOS, climate and topography data, we showed that species-specific models can explain up to 52 % of model variance (Quercus petraea), while combining different species results in relatively poor model performance (R2 = 13 %). The integration of EOS into models based solely on climate and elevation data improved the explained variance by 6 % on average. Leveraging these insights, we successfully generated a map of annual TRW for the year 2021. We employed the area of applicability (AOA) approach to delineate the range in which our models are deemed valid. The calculated AOA for the established forest-type models was 73 % of the study region, indicating robust spatial applicability. Notably, unreliable predictions predominantly occurred in the climate margins of our dataset. In conclusion, our large-scale assessment underscores the efficacy of combining climate, EOS and topographic data to develop robust models for mapping annual TRW. This research not only fills a critical void in the current understanding of forest growth dynamics but also highlights the potential of integrated data sources for comprehensive ecosystem assessments.

Variations in Proline Content, Polyamine Profiles, and Antioxidant Capacities among Different Provenances of European Beech (Fagus sylvatica L.)

International provenance trials are a hot topic in forestry, and in light of climate change, the search for more resilient beech provenances and their assisted migration is one of the challenges of climate-smart forestry. The main aim of the study was to determine intraspecific variability in European beech (Fagus sylvatica L.) among 11 beech provenances according to total antioxidant capacities estimated by various assays, such as DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic) acid), FRAP (ferric reducing antioxidant power) assay, and radical scavenging capacity against nitric oxide (RSC-NO assays), as well as osmolyte content, primarily individual polyamines (putrescine, spermidine, and spermine), and free proline content. Polyamine amounts were quantified by using HPLC coupled with fluorescent detection after dansylation pretreatment. The highest values for radical scavenger capacity assays (ABTS, DPPH, and FRAP) were measured in the German provenances DE47 and DE49. Also, the highest NO inhibition capacity was found in the provenance DE49, while the highest content of proline (PRO), total phenolic content (TPC), and total flavonoid content (TFC) was recorded in DE47. The Austrian AT56 and German provenance DE49 were most abundant in total polyamines. This research underlines the importance of the application of common antioxidant assays as well as osmolyte quantification as a criterion for the selection of climate-ready beech provenances for sustainable forest management.

Polyamines in Edible and Medicinal Fungi from Serbia: A Novel Perspective on Neuroprotective Properties

The therapeutic effectiveness of current neurodegenerative disease treatments is still under debate because of problems with bioavailability and a range of side effects. Fungi, which are increasingly recognized as sources of natural antioxidants and acetylcholinesterase (AChE) enzyme inhibitors, may thus serve as potent neuroprotective agents. Previous studies have associated the anti-AChE and antioxidant activities of fungi mostly with polysaccharides and phenolic compounds, while other secondary metabolites such as polyamines (PAs) have been neglected. This study aimed to investigate eight edible and medicinal fungi from Serbia, marking the initial investigation into the neuroprotective capabilities of Postia caesia, Clitocybe odora, Clitopilus prunulus, and Morchella elata. Neuroprotective activity was examined using the Ellman assay, while the antioxidant capacity was tested by conducting DPPH, NO, ABTS, and FRAP tests. PA levels were determined by high-performance liquid chromatography (HPLC) coupled with fluorescent detection. Ganoderma applanatum and Lepista nuda exhibited the most robust anti-AChE (98.05 ± 0.83% and 99.94 ± 3.10%, respectively) and antioxidant activities, attributed to the synergistic effects of the total protein, total phenolic, and PA levels. Furthermore, P. caesia displayed significant AChE inhibition (88.21 ± 4.76%), primarily linked to the elevated spermidine (SPD) (62.98 ± 3.19 mg/kg d.w.) and putrescine (PUT) levels (55.87 ± 3.16 mg/kg d.w.). Our results highlight the need for thorough research to comprehend the intricate relationships between distinct fungus species and AChE inhibition. However, it is important to recognize that more research is required to identify the precise substances causing the reported inhibitory effects.

A Fine-Tuning of the Plant Hormones, Polyamines and Osmolytes by Ectomycorrhizal Fungi Enhances Drought Tolerance in Pedunculate Oak

The drought sensitivity of the pedunculate oak (Quercus robur L.) poses a threat to its survival in light of climate change. Mycorrhizal fungi, which orchestrate biogeochemical cycles and particularly have an impact on the plant's defense mechanisms and metabolism of carbon, nitrogen, and phosphorus, are among the microbes that play a significant role in the mitigation of the effects of climate change on trees. The study's main objectives were to determine whether ectomycorrhizal (ECM) fungi alleviate the effects of drought stress in pedunculate oak and to investigate their priming properties. The effects of two levels of drought (mild and severe, corresponding to 60% and 30% of field capacity, respectively) on the biochemical response of pedunculate oak were examined in the presence and absence of ectomycorrhizal fungi. To examine whether the ectomycorrhizal fungi modulate the drought tolerance of pedunculate oak, levels of plant hormones and polyamines were quantified using UPLC-TQS and HPLC-FD techniques in addition to gas exchange measurements and the main osmolyte amounts (glycine betaine-GB and proline-PRO) which were determined spectrophotometrically. Droughts increased the accumulation of osmolytes, such as proline and glycine betaine, as well as higher polyamines (spermidine and spermine) levels and decreased putrescine levels in both, mycorrhized and non-mycorrhized oak seedlings. In addition to amplifying the response of oak to severe drought in terms of inducible proline and abscisic acid (ABA) levels, inoculation with ECM fungi significantly increased the constitutive levels of glycine betaine, spermine, and spermidine regardless of drought stress. This study found that compared to non-mycorrhized oak seedlings, unstressed ECM-inoculated oak seedlings had higher levels of salicylic (SA) and abscisic acid (ABA) but not jasmonic acid (JA), indicating a priming mechanism of ECM is conveyed via these plant hormones. According to a PCA analysis, the effect of drought was linked to the variability of parameters along the PC1 axe, such as osmolytes PRO, GB, polyamines, and plant hormones such as JA, JA-Ile, SAG, and SGE, whereas mycorrhization was more closely associated with the parameters gathered around the PC2 axe (SA, ODPA, ABA, and E). These findings highlight the beneficial function of the ectomycorrhizal fungi, in particular Scleroderma citrinum, in reducing the effects of drought stress in pedunculate oak.

Ectomycorrhizal Fungi Modulate Pedunculate Oak's Heat Stress Responses through the Alternation of Polyamines, Phenolics, and Osmotica Content

The physiological and biochemical responses of pedunculate oaks (Quercus robur L.) to heat stress (HS) and mycorrhization (individually as well in combination) were estimated. One-year-old Q. robur seedlings were grown under controlled conditions in a pot experiment, inoculated with a commercial inoculum of ectomycorrhizal (ECM) fungi, and subjected to 72 h of heat stress (40 °C/30 °C day/night temperature, relative humidity 80%, photoperiod 16/8 h) in a climate chamber, and they were compared with seedlings that were grown at room temperature (RT). An in-depth analysis of certain well-known stress-related metrics such as proline, total phenolics, FRAP, ABTS, non-protein thiols, and lipid peroxidation revealed that mycorrhized oak seedlings were more resistant to heat stress (HS) than non-mycorrhized oaks. Additionally, levels of specific polyamines, total phenolics, flavonoids, and condensed tannins as well as osmotica (proline and glycine betaine) content were measured and compared between four treatments: plants inoculated with ectomycorrhizal fungi exposed to heat stress (ECM-HS) and those grown only at RT (ECM-RT) versus non-mycorrhized controls exposed to heat stress (NM-HS) and those grown only at room temperature (NM-RT). In ectomycorrhiza inoculated oak seedlings, heat stress led to not only a rise in proline, total phenols, FRAP, ABTS, non-protein thiols, and lipid peroxidation but a notable decrease in glycine betaine and flavonoids. Amounts of three main polyamines (putrescine, spermine, and spermidine) were quantified by using high-performance liquid chromatography coupled with fluorescent detection (HPLC/FLD) after derivatization with dansyl-chloride. Heat stress significantly increased putrescine levels in non-mycorrhized oak seedlings but had no effect on spermidine or spermine levels, whereas heat stress significantly increased all inspected polyamine levels in oak seedlings inoculated with ectomycorrhizal inoculum. Spermidine (SPD) and spermine (SPM) contents were significantly higher in ECM-inoculated plants during heat stress (approximately 940 and 630 nmol g^-1 DW, respectively), whereas these compounds were present in smaller amounts in non-mycorrhized oak seedlings (between 510 and 550 nmol g^-1 DW for Spd and between 350 and 450 nmol g^-1 DW for Spm). These findings supported the priming and biofertilizer roles of ectomycorrhizal fungi in the mitigation of heat stress in pedunculate oaks by modification of polyamines, phenolics, and osmotica content.

Metal- and Organ-Specific Response to Heavy Metal-Induced Stress Mediated by Antioxidant Enzymes' Activities, Polyamines, and Plant Hormones Levels in Populus deltoides

Besides anthropogenic factors, climate change causes altered precipitation patterns that indirectly affect the increase of heavy metals in soils due to hydrological effects and enhanced leaching (i.e., Cd and Ni), especially in the vicinity of mines and smelters. Phytoextraction is a well-known, powerful "green" technique for environmental clean-up that uses plants to extract, sequester, and/or detoxify heavy metals, and it makes significant contributions to the removal of persistent inorganic pollutants from soils. Poplar species, due to their growth features, high transpiration rate, large biomass, and feasible reproduction represent great candidates for phytoextraction technology. However, the consequences of concomitant oxidative stress upon plant metabolism and the mechanism of the poplar's tolerance to heavy metal-induced stress are still not completely understood. In this study, cuttings of poplar species (Populus deltoides W. Bartram ex Marshall) were separately exposed to two heavy metals (Cd²⁺ and Ni²⁺) that were triple the maximum allowed amount (MAA) (according to national legislation). The aim of the study was to estimate the effects of heavy metals on: (I) the accumulation of free and conjugated polyamines, (II) plant hormones (including abscisic acid-ABA and indole-3-acetic acid-IAA), and (III) the activities of different antioxidant enzymes at root and leaf levels. By using the selected ion monitoring (SIM) mode of gas chromatography with mass spectrometry (GC/MS) coupled with the isotopically labeled technique, amounts of ABA and IAA were quantified, while polyamine amounts were determined by using high-performance liquid chromatography (HPLC) with fluorometric detection after derivatization. The results showed that P. deltoides responded to elevated concentrations of heavy metals in soils by exhibiting metal- and organ-specific tolerance. Knowledge about tolerance mechanisms is of great importance for the development of phytoremediation technology and afforestation programs for polluted soils.

Species-Level Differences in Osmoprotectants and Antioxidants Contribute to Stress Tolerance of Quercus robur L., and Q. cerris L. Seedlings under Water Deficit and High Temperatures

The general aim of this work was to compare the leaf-level responses of different protective components to water deficit and high temperatures in Quercus cerris L. and Quercus robur L. Several biochemical components of the osmotic adjustment and antioxidant system were investigated together with changes in hormones. Q. cerris and Q. robur seedlings responded to water deficit and high temperatures by: (1) activating a different pattern of osmoregulation and antioxidant mechanisms depending on the species and on the nature of the stress; (2) upregulating the synthesis of a newly-explored osmoprotectant, dimethylsulphoniopropionate (DMSP); (3) trading-off between metabolites; and (4) modulating hormone levels. Under water deficit, Q. cerris had a higher antioxidant capacity compared to Q. robur, which showed a lower investment in the antioxidant system. In both species, exposure to high temperatures induced a strong osmoregulation capacity that appeared largely conferred by DMSP in Q. cerris and by glycine betaine in Q. robur. Collectively, the more stress-responsive compounds in each species were those present at a significant basal level in non-stress conditions. Our results were discussed in terms of pre-adaptation and stress-induced metabolic patterns as related to species-specific stress tolerance features.

Different tree-ring width sensitivities to satellite-based soil moisture from dry, moderate and wet pedunculate oak (Quercus robur L.) stands across a southeastern distribution margin

Associations of pedunculate oak (Quercus robur L.) radial growth with satellite-based soil moisture (SM) during the intensive tree growth period over a 30-year time span (1980-2010) were analyzed. This study included tree-ring width (TRW) chronologies from 22 stands located in four southeastern (SE) European countries (Slovenia, Croatia, Serbia and Bulgaria), which were grouped into three wetness groups (WGs): dry (<650 mm), moderate (650-750 mm), and wet (>750 mm), following the annual sum of precipitation. High correlation strengths during the intensive growth period-late spring and early summer months (April to June) was noted, which was opposite to the trend in late summer months. Variations in detrended TRW (TRWi) sensitivity to SM were also observed among the WGs. Specifically, the TRWi chronologies from the dry and wet WGs provided a greater number of significant correlations (p < 0.01) than trees from the moderate WG did. In wetter stands, TRWi correlated more negatively in the wettest (spring) months, while the correlation was weaker in summer months; these trends were opposite to those of trees growing in drier conditions that had the strongest responses to SM. A generalized additive mixed model (GAMM) based on 38 variables indicated that the fit for SM and radial growth was as strong as the fits for other traditionally measured parameters (temperature, precipitation, and river water level) and calculated drought indices (standardized precipitation index and the Ellenberg index) and TRW. Additionally, radial growth chronologies from drier sites had stronger fits with surrounding environmental factors. In conclusion, our findings suggest that SM can potentially be used as a reliable remote sensing indicator of the soil wetness in oak forests, which affects tree productivity and radial growth patterns and provides a new opportunity in dendrochronology research on larger scales.

Comparing environmental impacts of alien plants, insects and pathogens in protected riparian forests

The prioritization of alien species according to the magnitude of their environmental impacts has become increasingly important for the management of invasive alien species. In this study, we applied the Environmental Impact Classification of Alien Taxa (EICAT) to classify alien taxa from three different taxonomic groups to facilitate the prioritisation of management actions for the threatened riparian forests of the Mura-Drava-Danube Biosphere Reserve, South East Europe. With local experts we collated a list of 198 alien species (115 plants, 45 insects, and 38 fungi) with populations reported in southeast European forest ecosystems and included them in the EICAT. We found impact reports for 114 species. Eleven of these species caused local extinctions of a native species, 35 led to a population decrease, 51 to a reduction in performance in at least one native species and for 17 alien species no effects on individual fitness of native species were detected. Fungi had significantly highest impact and were more likely to have information on their impacts reported. Competition and parasitism were the most important impact mechanisms of alien species. This study is, to our knowledge, the first application of EICAT to all known alien species of several taxonomic groups in a protected area. The impact rankings enabled to identify taxa that generally cause high impacts and to prioritize species for the management in protected areas according to their impact magnitudes. By following a standardized impact protocol, we identified several alien species causing high impacts that do not appear on any expert-based risk list, which are relevant for policymakers. Thus, we recommend that alien species be systematically screened to identify knowledge gaps and prioritize their management with respect to spatio-temporal trends in impact magnitudes.

[The effect of alphacalcidol on calcium and phosphate metabolism in patients treated with hemodialysis]

The purpose of these studies was to assess the effect of 6 month calcidol treatment on Ca and PO4 metabolism in haemodialyzed patients. During 3 and 6 month on alpha calcidol therapy, there was significant increase of total and ionized Ca (p < 0.05; p < 0.01 respectively). After 6 months on alpha calcidol therapy there was significant decrease of alkaline phosphatase level (p < 0.05) and increase in bone density (up to 82%, p < 0.05). The study has shown that appropriate use of alpha calcidol could be effective in treatment of Ca and PO4 disbalance in haemodialyzed patients.

[Anatomic and physiologic characteristics of the peritoneal cavity with reference to peritoneal dialysis]

Most common complications of peritoneal dialysis are those related to anatomic defect of the abdominal wall and peritoneum. The aim of this investigation was to examine the frequency of congenital and acquired wall defects in patients on CAPD treatment causing complications. Fifty patients, 32 women and 18 men, on CAPD treatment for more than two years, were investigated. Most common was a defect in the anterior-lateral abdominal wall predisposing to hernias in 14% of patients. Umbilical and pericatheteral hernias were more common than other, with a mean time of 21 months for the appearance. Persistence of vaginal process of peritoneum related to scrotal oedema was documented in 4% of patients. Communication of peritoneal cavity with the abdominal ostium of tuba uterina was found not to be an important factor for peritonitis.

[The effect of frequent peritonitis on parameters of efficacy of peritoneal dialysis]

The estimation of CAPD efficacy presents a complex problem in the patients treated by this method. The most important parameters are: clinical indications, biochemical parameters, Kt/v, PCT, PET indexes, and others. Numerous factors may influence CAPD efficacy. Peritonitis, particularly the frequent episodes, significantly affects permeability and ultrafiltration capacity of the peritoneal membrane. The aim of this paper is to investigate the peritonitis incidence and its influence on some parameters of CAPD efficacy. Forty-four CAPD patients of both sexes, aged 55.7 +/- 13.5 yrs, dialysis duration 19.6 +/- 15 months, were studied. The influence of peritonitis incidence was studied using urea, creatinine, hemoglobin, hematocrit parameters and K t/v, PET indexes. Statistically significant low K t/v values were found in the patients who had four or more peritonitis episodes. Our results, as well as those in the literature, indicate that frequent peritonitis episodes significantly decrease the peritoneal membrane permeability.

[Our protocol in the treatment of peritonitis in patients on continuous ambulatory peritoneal dialysis]

Peritonitis is a very serious complication in patients treated by CAPD. The frequent and grave episodes are the main cause for CAPD withdrawal. The effective prevention and adequate therapy of peritonitis are very important for a successful CAPD treatment. The aim of this study was to present our results of peritonitis therapy in CAPD patients using the following protocol: Vancomycin 1.0 g.i.p. immediately after the admission to the unit, 250 mg Ceftriaxon (Longaceph) after a bag exchange for seven days, and the 1.0 g Vancomycin. Using this protocol we treated 97 peritonitis episodes; 74 of them (80%) were treated successfully by this antibiotics combination. The clearness of peritoneal fluid was attained 1-3 days within 56.7% of cases, and 4-6 days within the 29.7% peritonitis episodes (86.4%). A common cause of peritonitis was Staphylococcus epidermidis episodes (28.4%), Staphylococcus aureus (13.5%), and in 39.1% episodes the cultures were sterile. Uneffective antibiotic application according to this protocol was found in cases of pseudomonas and fungal peritonitis. The mentioned antibiotic therapy had no effect in a small number of peritonitides provoked by S. epidermidis (8.7%) and S. aureus (13.0%) This required the application of a third antibiotic. It could be concluded that this antibiotic combination in treatment of peritonitis in patients on CAPD was very effective.

[The effect of parathormone on arterial blood pressure in patients on hemodialysis]

We evaluated the effect of PTH on blood pressure in haemodialysed patients. The correlation was found between systolic, diastolic pressure and PTH. The results have shown that PTH might have the influence on regulation of arterial blood pressure in these patients.

[Nutrition and physical activity of obese and properly nourished children]

The aim of the study which included 2297 children (aged 5-18), was to determine the role of nutrition and physical activity in the occurrence of obesity in this population. Nutritional status of children was estimated by body mass index. In order to examine nutrition we used a quantitative questionnaire, and physical activity was examined by a specially designed questionnaire (made according to the WHO recommendations). The obtained results showed that abundant nutrition and insufficient physical activity played a significant role in the occurrence of child obesity.

Design, synthesis and properties of several heterocyclic dopaminergic ligands

Two series of non-catechol dopamine (DA) bioisosteres with the hydroxyl groups on the benzene ring replaced by N-H groups were synthesized using phenethylamine as a parent molecule. Compounds from the first series (1-9) contained a primary amine group, while those from the second one (10-19) had a N,N-di-propylamino group introduced into the side chain of the phenethylamine. The affinity and selectivity of these compounds for the D-1 and D-2 subtypes of the DA receptor were determined in competition binding assays using synaptosomal membranes from bovine caudate nuclei and [3H]SCH 23390 (D-1 selective) and [3H]spiperone (D-2 selective) as radioligands. None of the 19 compounds examined expressed significant affinity for D-1 receptors, while compounds 15, 17 and 19, in this order of potency, strongly competed with [3H]spiperone binding to D-2 receptors under conditions that prevented radioligand binding to serotonin 5HT2 receptors. Varying affinities of the compounds examined for the DA receptors can be ascribed to different acidity of the N-H groups introduced at meta- and para-positions of the phenethylamine molecule.

Chronic biofiltration therapy

Long-term follow-up evaluation of biofiltration treatment in 7 patients is presented. These patients experienced frequent episodes of hypotension during acetate hemodialysis. A 3-year biofiltration treatment reduced by 43% episodes of symptomatic hypotension and produced a significant increase in the pretreatment pH and plasma bicarbonate levels. The beta 2-microglobulin level was significantly reduced during biofiltration therapy. The mean systolic and diastolic blood pressures slightly increased during biofiltration. Uremic polyneuropathy, as demonstrated by an increase in motor nerve conduction velocity, slightly improved. The patients reported increased comfort during biofiltration therapy.