Comprehensive characterization of PAHs profile in Serbian soils for conventional and organic production: potential sources and risk assessment.

This study presents a comprehensive characterization of occurrence and levels of 16 polycyclic aromatic hydrocarbons (PAHs) in arable soils used for conventional and organic production in northern and central part of Serbia as well as cross-border region with Hungary. Furthermore, this study includes a characterization of PAH sources and carcinogenic/non-carcinogenic human health risk for PAHs accumulated in analysed arable soils. The total concentration of 16 PAHs varied between 55 and 4584 µg kg-1 in agricultural soil used for conventional production and between 90 and 523 µg kg-1 in agricultural soil used for organic production. High molecular weight (HMW) PAHs were dominant compounds with similar contribution in both soil types (86% and 80% in conventional and in organic soil, respectively). Principal component analysis and diagnostic ratios of selected PAHs were used for identification of PAH sources in the analysed soils. Additionally, positive matrix factorization was applied for quantitative assessment. The results indicated that the major sources of PAHs were vehicle emissions, biomass and wood combustion, accounting for ~ 93% of PAHs. Exposure of farmers assessed through carcinogenic (TCR) and non-carcinogenic (THQ) risk did not exceed the acceptable threshold (TCR < 10-6 and THQ < 1). Oral ingestion was the main exposure route which accounted for 57% of TCR and 80% of THQ. It was followed by dermal contact. This investigation gives a valuable data insight into the PAHs presence in arable soils and reveals the absence of environmental and health risk. It also acknowledges the importance of comprehensive monitoring of these persistent pollutants.

Comprehensive characterization of stress tolerant bacteria with plant growth-promoting potential isolated from glyphosate-treated environment.

The application of plant growth-promoting bacteria in agricultural systems is an efficient and environment-friendly strategy to improve crop yields and maintain soil quality. However, as different soils have diverse and specific ecological characteristics and may represent adverse abiotic conditions, in vivo application requires the careful selection of the desired beneficial microorganisms. In this study we report Ensifer adhaerens SZMC 25856 and Pseudomonas resinovorans SZMC 25875 isolates recovered from glyphosate-treated soil to possess yet undiscovered plant growth-enhancing potential. The strains were found to promote the growth of tomato seedlings significantly, to have the ability of synthesizing indole-3-acetic acid and siderophores, to tolerate pH in the range of 6.59-7.96, salinity up to 12.5 g L-1 NaCl and drought up to 125 g L-1 polyethylene glycol 6000, as well as to survive in the presence of various pesticides including glyphosate, diuron, chlorotoluron, carbendazim and thiabendazole, and heavy metals such as Al, Fe, Mn, Zn, Pb and Cu. The plant growth-promoting traits of the examined E. adhaerens and P. resinovorans isolates and their tolerance to numerous abiotic stress factors make them promising candidates for application in different agricultural environments, including soils polluted with glyphosate.

Does the application of human waste as a fertilization material in agricultural production pose adverse effects on human health attributable to contaminants of emerging concern?

The QuEChERS (quick, easy, cheap, effective, rugged, and safe) ultrasound-assisted method was successfully used to determine the presence of contaminants of emerging concern (CECs) in both the growing medium (i.e. soil) and vegetable samples (i.e. potato, onion, celery, parsnip and carrot) cultivated in household gardens under field conditions impacted by the application of livestock manure mixed with human waste. CECs with a broad range of physico-chemical properties including pharmaceuticals, plasticizers, herbicides, personal care products, and biocides were investigated. Among all studied CECs, diclofenac (DCL), carbamazepine, bisphenol A (BPA) and estrogenic hormones (estrone (E1), 17α-ethinyl estradiol (EE2)) were detected and quantified in vegetable samples with a concentration range from 0.114 to 13.3 ng/g fresh weight (f.w.), while BPA, E1, and EE2 were detected in soil samples with concentration ranges from 0.526 to 0.830 ng/g f.w., 0.121-0.199 ng/g f.w. and 0.118-0.333 ng/g f.w., respectively. DCL was only quantified above the limit of quantification in one soil sample (0.151 ng/g f.w.). The human health risk was estimated using the threshold of toxicological concern approach and a standard diet for two segments of the population (i.e. adult and child). The consumption of investigated vegetables contaminated with CECs poses no risk for the Serbian population.

Occurrence of heavy elements in street dust from sub/urban zone of Tianjin: pollution characteristics and health risk assessment.

Main purpose of this study was to determine the concentrations of selected heavy elements (As, Cd, Pb, Cu, Co, Cr and Ni) in the street dust samples (n = 49) collected from seven districts located in suburban/urban zone of Tianjin in order to estimate their possible sources and degree of environmental pollution as well as human health risk. Mean concentrations (mg kg-1) of As (19.3), Cd (0.60), Pb (28.4) and Cu (62.7) were above their corresponding soil background values. According to the results of multivariate statistical analysis, the accumulation of As, Cd, Pb, Cu and Cr in street dust was affected by anthropogenic activities, while the contents of Ni and Co were associated with natural sources. Pollution degree by geo-accumulation index had the following trend: Cd > Cu > As > Pb > Cr > Ni > Co. Dust contamination with Cd ranged from unpolluted to highly polluted. Potential ecological risk indicated low (Pb, Cu, Cr, Co and Ni) to high (Cd) risk, while potential risk index showed moderate and very high risks. Non-carcinogenic risk of the studied elements was below safe level (<1). Data obtained in this investigation gave the additional values to the knowledge needed for future monitoring and risk assessment, relating the presence of heavy elements studied in suburban/urban areas.

Survey on the micro-pollutants presence in surface water system of northern Serbia and environmental and health risk assessment.

This study demonstrates the occurrence of 940 organic micro-pollutants in surface water of four rivers, one irrigation canal system, and two lakes in Vojvodina Province, the northern part of Serbia, summing in total eighteen samples. The number of detected chemicals ranged from 22 to 84, with 127 micro-pollutants detected at least once, representing 13% of the studied substances. The targeted compounds include n-alkanes, sterols, polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides polychlorinated biphenyls, pesticides, pharmaceutical active compounds, industrial chemicals, plasticizers, etc. Among the analysed compounds, sterols were the most dominant with maximum quantified concentrations. The substances which were quantified with frequency over 50% were two PAHs (2-methylnaphthalene, benzo(ghi)perylene), five sterols (cholesterol, cholestanol, stigmasterol, fucosterol, beta-sitosterol), three pharmaceuticals and personal care products (L-menthol, diethyltoluamide, caffeine), and ten household chemicals (4-tert-octylphenol, dimethyl phthalate, methyl palmitate, phenylethyl alcohol, 1-nonanol, alpha-terpineol, 2-phenoxy-ethanol, methyl myristate, acetophenone, and 2-ethyl-1-hexanol). The list of priority substances under the European Union Directive 2013/39/EU includes 49 priority substances (PSs) out of which 34 were analysed. Among these, eleven PSs were quantified, and only two compounds (fluoranthene and benzo (a) pyrene) exceeded EU Environmental Quality Standards targeted values. The obtained results were compared with the previously published data that dealt with the same targeted number of micro-pollutants in sediment samples. This revealed connections between the same sampling locations. Environmental risk assessment showed the existence of potential ecological risk as 72% of the obtained values for the ecological hazard index (HI) at investigated locations were higher that the targeted value (HI > 1). Estimated values for hazard quotient (HQ) and hazard index (HI) for non-carcinogenic risk were lower than the targeted value, indicating no non-carcinogenic risk through dermal contact and non-intentional ingestion of water. Estimated values for cancer risk were all below 1 × 10-6, which is not considered to pose significant human health risk.

Development of a sensitive and robust online dual column liquid chromatography-tandem mass spectrometry method for the analysis of natural and synthetic estrogens and their conjugates in river water and wastewater.

An online ultra-high-performance-liquid chromatography-triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) method for detection and quantification of natural and synthetic estrogens and their conjugates in aqueous matrices was developed. Target compounds include the natural estrogen estradiol (E2) and its main metabolites estrone (E1) and estriol (E3), the synthetic estrogens ethinylestradiol (EE2) and diethylstilbestrol (DES) and their conjugates estrone 3-sulfate (E1-3S), estriol 3-sulfate (E3-3S), estradiol 17-glucuronide (E2-17G), estrone 3-glucuronide (E1-3G), and estriol 16-glucuronide (E3-16G). After pH adjustment, sample filtration and addition of internal standards (IS), water samples (5 mL) were preconcentrated on a Hypersil GOLD aQ column after which chromatographic separation was achieved on a Kinetex C18 column using methanol and water as a mobile phase. The experimental parameters, such as sample loading flow rate, elution time, the percentage of organic solvent in the aqueous-organic eluent mixture, pH, and volume of analyzed samples, were optimized in detail. The benefits of the method compared to previously published methods include minimum sample manipulation, lower detection limits, reduced total analysis time, and overall increased method accuracy and precision. Method detection limits (MDLs) are in subnanogram per liter, complying with the requirements of the EC Decision 2015/495 (Watch list) for hormones listed therein. Applicability of the developed method was confirmed by analysis of river and raw wastewater samples taken directly from urban sewerage systems before being discharged into the river. Graphical abstract Sheme of online SPE-UHPLC-MS/MS system.

Esterification of sludge palm oil as a pretreatment step for biodiesel production.

Acid esterification of sludge palm oil, having 50 mas.% free fatty acids, i.e., 50 g of dominant free fatty acid per 100 g of oil, was investigated with the objective of determining conditions for the efficient reduction of free fatty acids. The influences of sulphuric acid dosage and molar ratio of methanol to oil were studied, with the final intention to obtain feedstock with a free fatty acids content acceptable for biodiesel production by alkali-transesterification. Esterification was performed using different molar ratios of methanol to oil (3:1, 6:1 and 9:1) and varying the amount of H2SO4 catalyst (0.92 mas.%, 1.84 mas.% and 4.60 mas.%). Under the applied conditions, the sulphuric acid dosage of 4.60 mas.% resulted in the satisfactory decrease of the feedstock's free fatty acids for 6:1 and 9:1 molar ratios of methanol to oil. Thus, taking into account the economic reasoning, it can be concluded that approximately 5 mas.% of H2SO4 with 6:1 molar ratio of methanol to oily feedstock, might be regarded as the dosage necessary for satisfactory pretreatment of the feedstock to be further subjected to the alkaline transesterification. Finally, the effort to consolidate the information on acid esterification available in literature was made, contributing to knowledge on sustainable biodiesel production using the low-grade and low-cost sources.

Attenuated development of cardiac fibrosis in left ventricular pressure overload by SM16, an orally active inhibitor of ALK5.

Pressure overload-induced TGF-ß signaling activates cardiac fibroblasts (CFB) and leads to increased extracellular matrix (ECM) protein synthesis including fibrosis. Excessive ECM accumulation may in turn affect cardiac function contributing to development of heart failure. The aim of this study was to examine the effects of SM16, an orally active small molecular inhibitor of ALK5, on pressure overload-induced cardiac fibrosis. One week after aortic banding (AB), C57Bl/6J mice were randomized to standard chow or chow with SM16. Sham operated animals served as controls. Following 4 weeks AB, mice were characterized by echocardiography and cardiovascular magnetic resonance before sacrifice. SM16 abolished phosphorylation of SMAD2 induced by AB in vivo and by TGF-ß in CFB in vitro. Interestingly, Masson Trichrome and Picrosirius Red stained myocardial left ventricular tissue revealed reduced development of fibrosis and collagen cross-linking following AB in the SM16 treated group, which was confirmed by reduced hydroxyproline incorporation. Furthermore, treatment with SM16 attenuated mRNA expression following induction of AB in vivo and stimulation with TGF-ß in CFB in vitro of Col1a2, the cross-linking enzyme LOX, and the pro-fibrotic glycoproteins SPARC and osteopontin. Reduced ECM synthesis by CFB and a reduction in myocardial stiffness due to attenuated development of fibrosis and collagen cross-linking might have contributed to the improved diastolic function and cardiac output seen in vivo, in combination with reduced lung weight and ANP expression by treatment with SM16. Despite these beneficial effects on cardiac function and development of heart failure, mice treated with SM16 exhibited increased mortality, increased LV dilatation and inflammatory heart valve lesions that may limit the use of SM16 and possibly also other small molecular inhibitors of ALK5, as future therapeutic drugs.

Identifying pathogenic processes by integrating microarray data with prior knowledge.

BACKGROUND: It is of great importance to identify molecular processes and pathways that are involved in disease etiology. Although there has been an extensive use of various high-throughput methods for this task, pathogenic pathways are still not completely understood. Often the set of genes or proteins identified as altered in genome-wide screens show a poor overlap with canonical disease pathways. These findings are difficult to interpret, yet crucial in order to improve the understanding of the molecular processes underlying the disease progression. We present a novel method for identifying groups of connected molecules from a set of differentially expressed genes. These groups represent functional modules sharing common cellular function and involve signaling and regulatory events. Specifically, our method makes use of Bayesian statistics to identify groups of co-regulated genes based on the microarray data, where external information about molecular interactions and connections are used as priors in the group assignments. Markov chain Monte Carlo sampling is used to search for the most reliable grouping. RESULTS: Simulation results showed that the method improved the ability of identifying correct groups compared to traditional clustering, especially for small sample sizes. Applied to a microarray heart failure dataset the method found one large cluster with several genes important for the structure of the extracellular matrix and a smaller group with many genes involved in carbohydrate metabolism. The method was also applied to a microarray dataset on melanoma cancer patients with or without metastasis, where the main cluster was dominated by genes related to keratinocyte differentiation. CONCLUSION: Our method found clusters overlapping with known pathogenic processes, but also pointed to new connections extending beyond the classical pathways.

Assessment of perfluoroalkyl substances in food items at global scale.

This study assessed the levels of 21 perfluoroalkyl substances (PFASs) in 283 food items (38 from Brazil, 35 from Saudi Arabia, 174 from Spain and 36 from Serbia) among the most widely consumed foodstuffs in these geographical areas. These countries were chosen as representatives of the diet in South America, Western Asia, Mediterranean countries and South-Eastern Europe. The analysis of foodstuffs was carried out by turbulent flow chromatography (TFC) combined with liquid chromatography with triple quadrupole mass spectrometry (LC-QqQ-MS) using electrospray ionization (ESI) in negative mode. The analytical method was validated for the analysis of different foodstuff classes (cereals, fish, fruit, milk, ready-to-eat foods, oil and meat). The analytical parameters of the method fulfill the requirements specified in the Commission Recommendation 2010/161/EU. Recovery rates were in the range between 70% and 120%. For all the selected matrices, the method limits of detection (MLOD) and the method limits of quantification (MLOQ) were in the range of 5 to 650 pg/g and 17 to 2000 pg/g, respectively. In general trends, the concentrations of PFASs were in the pg/g or pg/mL levels. The more frequently detected compounds were perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorobutanoic acid (PFBA). The prevalence of the eight-carbon chain compounds in biota indicates the high stability and bioaccumulation potential of these compounds. But, at the same time, the high frequency of the shorter chain compounds is also an indication of the use of replacement compounds in the new fluorinated materials. When comparing the compounds profile and their relative abundances in the samples from diverse origin, differences were identified. However, in absolute amounts of total PFASs no large differences were found between the studied countries. Fish and seafood were identified as the major PFASs contributors to the diet in all the countries. The total sum of PFASs in fresh fish and seafood was in the range from the MLOQ to 28ng/g ww. According to the FAO-WHO diets composition, the daily intake (DI) of PFASs was calculated for various age and gender groups in the different diets. The total PFASs food intake was estimated to be between 2300 and 3800 ng /person per day for the different diets. Finally, the risk intake (RI) was calculated for selected relevant compounds. The results have indicated that by far in no case the tolerable daily intake (TDI) (150, 1500, 50,000, 1,000,000, 150, 1500 ng/kg body weight, for perfluorohexanesulfonate (PFHxS), fluorotelomer alcohol (FTOH), perfluorobutanesulfonic acid (PFBS), perfluorobutanoic acid (PFBA), PFOS and PFOA, respectively) was exceeded.

Characterization of an extracellular laccase of Leptosphaerulina chartarum.

Laccase-producing fungi were isolated from air, using selective media with a chromogenic substrate to indicate enzyme activity. The best laccase producer strain proved to be a Leptosphaerulina chartarum isolate. Laccase production was investigated in the presence of various inducers in different cultivation conditions. The extracellular laccase was purified for further investigations. SDS-PAGE showed that this laccase is a monomeric protein of 38 kDa molecular weight. The enzyme is active in the pH-range of 3.5-6, with an optimum at pH 3.8. It is active in the 10-60 °C temperature range, with an optimum at 40 °C. After 20 min incubation at temperatures above 70 °C the enzyme lost its activity. Degradation of seven aniline and phenol compounds (2,4-dichlorophenol; 2-methyl-4-chlorophenol; 3-chloroaniline; 4-chloroaniline; 2,6-dimethylaniline; 3,4-dichloroaniline and 3-chloro-4-methylaniline) was investigated, with or without guaiacol (2-methoxyphenol) as mediator molecule. Addition of a mediator to the system significantly increased the degradation levels. These results confirmed that the isolated laccase is able to convert these harmful xenobiotics at in vitro conditions.

Syndecan-4 signaling via NFAT regulates extracellular matrix production and cardiac myofibroblast differentiation in response to mechanical stress.

Pressure overload activates cardiac fibroblasts leading to excessive production of extracellular matrix which may contribute to compromised heart function. The activated fibroblast acquires smooth muscle-like features such as expression of smooth muscle α-actin (SMA) and SM22 and is therefore referred to as myofibroblast. The molecular mechanisms underlying mechanical stress-induced myofibroblast differentiation are poorly defined. The objective of this study was to examine the potential roles of the transmembrane proteoglycan syndecan-4 and the calcineurin-dependent transcription factor nuclear factor of activated T-cells (NFAT) in myofibroblast differentiation. Aortic banding resulted in elevated collagen I and III, fibronectin, SMA and SM22 mRNA in the left ventricles of wild-type mice, whereas this response was markedly reduced in syndecan-4(-/-) mice. Myofibroblast differentiation in vitro was associated with increased SMA, collagen I and III expression and NFAT-luciferase activity, all of which were reduced in fibroblasts from syndecan-4(-/-) mice or after treatment with calcineurin/NFAT blockers. Following cyclic stretch, NFATc4 was activated in cardiac fibroblasts in a syndecan-4- and calcineurin-dependent manner. Syndecan-4 and calcineurin co-localized and mechanical stress resulted in dephosphorylation of serine179 of syndecan-4, an intracellular residue critical for calcineurin interaction. Over-expression of NFATc4 up-regulated collagen III, MRTF-A (a transcriptional regulator of SMA) and the NFAT-target regulator of calcineurin 1.4 (RCAN1.4). Our data demonstrate that syndecan-4 is important for the differentiation of cardiac fibroblasts into myofibroblasts in the pressure-overloaded heart and that the calcineurin/NFAT pathway is engaged upon mechanical stress in a syndecan-4-dependent manner, playing an active role in myofibroblast differentiation and extracellular matrix production. This article is part of a Special Issue entitled 'Possible Editorial'.

Slow Ca²âº sparks de-synchronize Ca²âº release in failing cardiomyocytes: evidence for altered configuration of Ca²âº release units?

In heart failure, cardiomyocytes exhibit slowing of the rising phase of the Ca(2+) transient which contributes to the impaired contractility observed in this condition. We investigated whether alterations in ryanodine receptor function promote slowing of Ca(2+) release in a murine model of congestive heart failure (CHF). Myocardial infarction was induced by left coronary artery ligation. When chronic CHF had developed (10 weeks post-infarction), cardiomyocytes were isolated from viable regions of the septum. Septal myocytes from SHAM-operated mice served as controls. Ca(2+) transients rose markedly slower in CHF than SHAM myocytes with longer time to peak (CHF=152 ± 12% of SHAM, P<0.05). The rise time of Ca(2+) sparks was also increased in CHF (SHAM=9.6 ± 0.6 ms, CHF=13.2 ± 0.7 ms, P<0.05), due to a sub-population of sparks (≈20%) with markedly slowed kinetics. Regions of the cell associated with these slow spontaneous sparks also exhibited slowed Ca(2+) release during the action potential. Thus, greater variability in spark kinetics in CHF promoted less uniform Ca(2+) release across the cell. Dyssynchronous Ca(2+) transients in CHF additionally resulted from T-tubule disorganization, as indicated by fast Fourier transforms, but slow sparks were not associated with orphaned ryanodine receptors. Rather, mathematical modeling suggested that slow sparks could result from an altered composition of Ca(2+) release units, including a reduction in ryanodine receptor density and/or distribution of ryanodine receptors into sub-clusters. In conclusion, our findings indicate that slowed, dyssynchronous Ca(2+) transients in CHF result from alterations in Ca(2+) sparks, consistent with rearrangement of ryanodine receptors within Ca(2+) release units.

Improved MR phase-contrast velocimetry using a novel nine-point balanced motion-encoding scheme with increased robustness to eddy current effects.

Phase-contrast MRI (PC-MRI) velocimetry is a noninvasive, high-resolution motion assessment tool. However, high motion sensitivity requires strong motion-encoding magnetic gradients, making phase-contrast-MRI prone to baseline shift artifacts due to the generation of eddy currents. In this study, we propose a novel nine-point balanced velocity-encoding strategy, designed to be more accurate in the presence of strong and rapidly changing gradients. The proposed method was validated using a rotating phantom, and its robustness and precision were explored and compared with established approaches through computer simulations and in vivo experiments. Computer simulations yielded a 39-57% improvement in velocity-noise ratio (corresponding to a 27-33% reduction in measurement error), depending on which method was used for comparison. Moreover, in vivo experiments confirmed this by demonstrating a 26-53% reduction in accumulated velocity error over the R-R interval. The nine-point balanced phase-contrast-MRI-encoding strategy is likely useful for settings where high spatial and temporal resolution and/or high motion sensitivity is required, such as in high-resolution rodent myocardial tissue phase mapping.

Comparison of multianalyte proficiency test results by sum of ranking differences, principal component analysis, and hierarchical cluster analysis.

Sum of ranking differences (SRD) was applied for comparing multianalyte results obtained by several analytical methods used in one or in different laboratories, i.e., for ranking the overall performances of the methods (or laboratories) in simultaneous determination of the same set of analytes. The data sets for testing of the SRD applicability contained the results reported during one of the proficiency tests (PTs) organized by EU Reference Laboratory for Polycyclic Aromatic Hydrocarbons (EU-RL-PAH). In this way, the SRD was also tested as a discriminant method alternative to existing average performance scores used to compare mutlianalyte PT results. SRD should be used along with the z scores--the most commonly used PT performance statistics. SRD was further developed to handle the same rankings (ties) among laboratories. Two benchmark concentration series were selected as reference: (a) the assigned PAH concentrations (determined precisely beforehand by the EU-RL-PAH) and (b) the averages of all individual PAH concentrations determined by each laboratory. Ranking relative to the assigned values and also to the average (or median) values pointed to the laboratories with the most extreme results, as well as revealed groups of laboratories with similar overall performances. SRD reveals differences between methods or laboratories even if classical test(s) cannot. The ranking was validated using comparison of ranks by random numbers (a randomization test) and using seven folds cross-validation, which highlighted the similarities among the (methods used in) laboratories. Principal component analysis and hierarchical cluster analysis justified the findings based on SRD ranking/grouping. If the PAH-concentrations are row-scaled, (i.e., z scores are analyzed as input for ranking) SRD can still be used for checking the normality of errors. Moreover, cross-validation of SRD on z scores groups the laboratories similarly. The SRD technique is general in nature, i.e., it can be applied to any experimental problem in which multianalyte results obtained either by several analytical procedures, analysts, instruments, or laboratories need to be compared.

Isolation and characterization of antagonistic Bacillus strains capable to degrade ethylenethiourea.

In this study, more than 150 bacteria showing antagonistic properties against bacterial and fungal pathogens of the tomato plant were isolated and characterized. The most efficient agents against these phytopathogenic microorganisms belong to the genus Bacillus: the best biocontrol isolates were representatives of Bacillus subtilis, B. mojavensis and B. amyloliquefaciens species. They intensively produced fengycin or/and surfactin depsipeptide antibiotics and also proved to be excellent protease secretors. It was proved, that the selected strains were able to use ethylenethiourea (ETU) as sole nitrogen source. These antagonistic and ETU-degrading Bacillus strains can be applied as biocontrol and also as bioremediation agents.

Distribution of heavy elements in urban and rural surface soils: the Novi Sad city and the surrounding settlements, Serbia.

Concentrations of ten heavy elements (Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, and Zn), as well as the pH values, organic matter contents, and electrical conductivities were measured in the surface soil samples collected from 21 sites of urban areas in the city of Novi Sad, the second largest city in Serbia, its suburban settlement and the nearby villages. Range of the heavy element concentrations was from 0.16 mg/kg (for Hg) to 18,994 mg/kg (for Fe). Significantly higher Hg and Mn concentrations were observed in subgroups with rural and market garden samples in comparison to the subgroups with urban and grassland samples, respectively, while the contents of Pb found in the grasslands subgroup were significantly higher than in the subgroup with market garden soils. Only one sample of urban soil exceeded the maximum permissible value for Zn set by the relevant Serbian legislation. According to the Dutch soil quality standard, the Cd and Co concentrations in majority of the examined soils were higher than the target values for unpolluted soil. The content of Hg was above the target value in 52% of the samples, most of them belonging to the subgroup of market garden soils. The results for the Novi Sad city area were compared to the relevant data available for other cities in the Western Balkan Countries. Principal component analysis of data revealed seven outlying samples, while the rest of the analyzed samples were grouped together indicating similar heavy element patterns most probably due to mixed emission sources.

Advantages of Multiplexing Ability of the Orbitrap Mass Analyzer in the Multi-Mycotoxin Analysis.

In routine measurements, the length of the analysis time and nfumber of samples analysed during a time unit are crucial parameters, which are especially important for the food analysis, particularly in the case of mycotoxin determinations. High-resolution equipment, including time-of-flight or Orbitrap analyzators, can provide stable instrumental background for high-throughput analyses. In this report, a short, 1 min MS-based multi-mycotoxin method was developed with the application of a short column as a reduced chromatographic separation, taking advantages of the multiplexing and high-resolution capability of the QExactive Orbitrap MS possessing sub-1 ppm mass accuracy. The performance of the method was evaluated regarding selectivity, LOD, LOQ, linearity, matrix effect, and recovery, and compared to a UHPLC-MS/MS method. The final multiplexing method was able to quantify 11 mycotoxins in defined ranges (aflatoxins (corn, 2.8-600 µg/kg; wheat, 1.5-350 µg/kg), deoxynivalenol (corn, 640-9600 µg/kg; wheat, 128-3500 µg/kg), fumonisins (corn, 20-1500 µg/kg; wheat, 30-3500 µg/kg), HT-2 (corn, 64-5200 µg/kg; wheat, 61-3500 µg/kg), T-2 (corn, 10-800 µg/kg; wheat, 4-250 µg/kg), ochratoxin (corn, 4.7-600 µg/kg; wheat, 1-1000 µg/kg), zearalenone (corn, 64-4800 µg/kg; wheat, 4-500 µg/kg)) within one minute in corn and wheat matrices at the MRL levels stated by the European Union.

Development of a Multicomponent Microbiological Soil Inoculant and Its Performance in Sweet Potato Cultivation.

The cultivation and consumption of sweet potato (Ipomoea batatas) are increasing globally. As the usage of chemical fertilizers and pest control agents during its cultivation may lead to soil, water and air pollution, there is an emerging need for environment-friendly, biological solutions enabling increased amounts of healthy crop and efficient disease management. Microbiological agents for agricultural purposes gained increasing importance in the past few decades. Our goal was to develop an agricultural soil inoculant from multiple microorganisms and test its application potential in sweet potato cultivation. Two Trichoderma strains were selected: Trichoderma ghanense strain SZMC 25217 based on its extracellular enzyme activities for the biodegradation of plant residues, and Trichoderma afroharzianum strain SZMC 25231 for biocontrol purposes against fungal plant pathogens. The Bacillus velezensis strain SZMC 24986 proved to be the best growth inhibitor of most of the nine tested strains of fungal species known as plant pathogens, therefore it was also selected for biocontrol purposes against fungal plant pathogens. Arthrobacter globiformis strain SZMC 25081, showing the fastest growth on nitrogen-free medium, was selected as a component with possible nitrogen-fixing potential. A Pseudomonas resinovorans strain, SZMC 25872, was selected for its ability to produce indole-3-acetic acid, which is among the important traits of potential plant growth-promoting rhizobacteria (PGPR). A series of experiments were performed to test the selected strains for their tolerance to abiotic stress factors such as pH, temperature, water activity and fungicides, influencing the survivability in agricultural environments. The selected strains were used to treat sweet potato in two separate field experiments. Yield increase was observed for the plants treated with the selected microbial consortium (synthetic community) in comparison with the control group in both cases. Our results suggest that the developed microbial inoculant has the potential to be used in sweet potato plantations. To the best of our knowledge, this is the first report about the successful application of a fungal-bacterial consortium in sweet potato cultivation.

Aquaporin-4 in the heart: expression, regulation and functional role in ischemia.

Aquaporins (AQPs) are channel-forming membrane proteins highly permeable to water. AQP4 is found in mammalian hearts; however, its expression sites, regulation and function are largely unknown. The aim was to investigate cardiac AQP4 expression in humans and mice, its regulation by ischemia and hypoxia, and in particular its role in cardiac ischemic injury using AQP4 knockout (KO) mice. Comparable levels of AQP4 were detected by Western blot and qPCR in biopsies from human donor hearts and wild type C57Bl6 mouse hearts. In mice, AQP4 was expressed on cardiomyocyte plasmalemma (qPCR, Western blot, immunogold), and its mRNA decreased following ischemia/reperfusion (isolated hearts, p = 0.02) and after normobaric hypoxia in vivo (oxygen fraction 10 % for 1 week, p < 0.001). Isolated hearts from AQP4 KO mice undergoing global ischemia and reperfusion had reduced infarct size (p = 0.05) and attenuated left ventricular end-diastolic pressure during reperfusion (p = 0.04). Infarct size was also reduced in AQP4 KO mice 24 h after left coronary artery ligation in vivo (p = 0.036). AQP4 KO hearts had no compensatory change in AQP1 protein expression. AQP4 KO cardiomyocytes were partially resisted to hypoosmotic stress in the presence of hypercontracture. AQP4 is expressed in human and mouse hearts, in the latter confined to the cardiomyocyte plasmalemma. AQP4 mRNA expression is downregulated by hypoxia and ischemia. Deletion of AQP4 is protective in acute myocardial ischemia-reperfusion, and this molecule might be a future target in the treatment of acute myocardial infarction.