Hydrogels from Fundaments to Application

Polymer superabsorbents commonly known as hydrogels are cross-linked highly molecular compounds able to absorb water from physicochemical fluids in the amounts from 10-fold to 100-fold larger than their dry mass. Numerous investigations have shown that they can help reduce irrigation water consumption, lower the death rate of plants, improve fertilizer retention in soil and increase plant growth rate. Besides water absorption and retention, the superabsorbent polymers have many advantages over conventional ones, such as a sustained supply of nutrition to plants for a longer time, thus increasing the phosphate fertilizer use efficiency and decreasing application frequency. The aim of this study is to investigate the influence of chemical conditions on hydrogels, kinetic and absorption behaviour towards metal ions in the presence of the chelating agent of a new generation. In this group, there are IDS, EDDS, GLDA, MGDA, etc. In the chapter, the research on the applicability of the effective absorption of metal complexes with a biodegradable complexing agent will be presented. The possibility of the preparation of slow-release fertilizers of controlled activity of a new generation in such system will also be discussed

PCR-RFLP detection of point mutations A2143G and A2142G in 23S rRNA gene conferring resistance to clarithromycin in Helicobacter pylori strains

Background. The occurrence of clarithromycin resistance among Helicobacter pylori strains is a major cause of the treatment failure. Resistance to this drug is conferred by point mutations in 23S rRNA gene and the most prevalent mutations are A2143G and A2142G. The aim of the study was to evaluate the occurrence of A2143G and A2142G mutations in a group of H. pylori strains resistant to clarithromycin. Materials and Methods. The study included 21 clarithromycin-resistant H. pylori strains collected between 2006 and 2009 in southern Poland. Resistance to clarithromycin was quantitatively tested with the E-test to determine the minimal inhibitory concentration (MIC value). The point mutations of H. pylori isolates were detected by PCR followed by RFLP analysis. Results. The MIC values for clarithromycin for the analyzed strains ranged from 1.5 mg/L to 64 mg/L. Nine H. pylori strains exhibited A2143G mutation and A2142G mutation was found in 9 isolates as well. The results of RFLP analysis of 3 clarithromycin-resistant strains were negative for both mutations. The average MIC values for A2143G and A2142G mutants were 6 and 30 mg/L, respectively. Conclusions. Frequencies of A2143G and A2142G mutations were the same in all isolates tested. Strains with A2143G mutation exhibited lower MIC values than A2142G mutants. Application of PCR-RFLP method for detection of clarithromycin resistance allows for better and more efficient management of H. pylori infections

Seasonal Variability of PM10 Chemical Composition Including 1,3,5-triphenylbenzene, Marker of Plastic Combustion and Toxicity in Wadowice, South Poland

ABSTRACT The objective of this research was to evaluate the seasonal variation of the chemical composition of PM10 including polycyclic aromatic hydrocarbons (PAHs) and 1,3,5-triphenylbenzene (135TPB), which is a well known marker of plastic combustion. The presented work is a part of the project concerning assessment of air quality of small cities around Krakow agglomeration. Monitoring campaign was conducted between February and October 2017 in Wadowice, a small city in Krakow agglomeration, South Poland. To widen the knowledge of Krakow's agglomeration air quality, other aerosol chemical components were analyzed. Ion chromatography (IC) was used for analysis of cations and anions, while gas chromatography-mass spectrometry (GC-MS) was used for PAHs. Samples were also analyzed for OC/EC (organic/elemental carbon) by thermal-optical analysis with a Sunset Laboratory carbon analyzer, Sunset Inc. The co-combustion of plastic in addition to conventional fuels and the respective impact on air quality is evaluated via the concentration of the marker compound 135TPB. Co-combustion of plastics with fuels resulted in a higher abundance of fluorene and most of 4–6 ring PAHs, in agreement with recent literature. Authors proved that other sources besides plastic burning, including road transport, residential heating, residential combustion, industrial emissions, affect the air quality in South Poland. The modeling tool Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT), developed by NOAA's Air Resources Laboratory, was used to define the possible areas outside Wadowice contributing to urban air pollution

Variability in Prevalence of Helicobacter pylori Strains Resistant to Clarithromycin and Levofloxacin in Southern Poland

Background. An increasing resistance of Helicobacter pylori strains to antimicrobial agents is the serious therapeutic problem. The aim of this study was to compare the primary and secondary resistance of H. pylori strains isolated between 2006–2008 (data published) and 2009–2011 to clarithromycin and levofloxacin. Material and Methods. 220 dyspeptic patients (153 before treatment, 67 after), were enrolled in the study. 51 H. pylori strains were isolated. MIC values of clarithromycin and levofloxacin were determined by the E-test method. The statistical analysis was conducted with the χ2 test with Yates correction at the 0.05 significance level (P ≤ 0.05). Results. Between 2006 and 2008, 34% (39/115) of H. pylori strains were resistant to clarithromycin (primary 21% (19/90), secondary 80% (20/25)). 5% (6/115) of strains were resistant to levofloxacin (primary 2% (2/90), secondary 16% ((4/25); data published) Between 2009–2011, 22% (11/51) of H. pylori strains were resistant to clarithromycin (primary 19% (8/43), secondary 38% (3/8)). 16% (8/51) of strains were resistant to levofloxacin (primary 12% (5/43), secondary 38% (3/8)). Conclusion. The present study has shown the increasing amount of resistant H. pylori strains isolated from patients in Southern Poland to levofloxacin and decreasing number of resistant strains to clarithromycin

Levofloxacin resistance of "Helicobacter pylori" strains isolated from patients in Southern Poland between 2006-2012

An increasing resistance of Helicobacter pylori (H. pylori) to antimicrobial agents leads to the need of regional monitoring of the prevalence resistant strains (according to the Maastricht/Florence consensus report, 2012). The aim of the study was to assess the resistance to levofloxacin of H. pylori strains isolated from adult patients of Ma≥opolska region in Poland. Bioptates taken from gastric mucosa during gastroscopy constituted the material for the study. Two hundred ten H. pylori strains were isolated from 811 patients. A majority of strains (171) came from patients before the treatment of H. pylori infections while the remaining 39 strains were isolated from patients after the failed therapy. Susceptibility of H. pylori to levofloxacin was determined by strips impregnated with antibiotic gradient (E-test, bioMerieux). The obtained minimum inhibitory concentration (MIC) values ranged from 0.002 mg/L to 32 mg/L. The percentage of strains resistant to levofloxacin amounted to 8.10% (17/210). Among the group of strains isolated from patients before the treatment, 5.85% (10/171) of H. pylori strains were resistant to levofloxacin. In the group of strains isolated from patients after the treatment 17.95% (7/39) of strains were resistant. The difference in the frequency of H. pylori strains resistant to levofloxacin in patients before and after the treatment of the infection due to H. pylori was statistically significant (p = 0.0297). The low percentage of H. pylori strains resistant to levofloxacin justify that the introduction of a triple therapy with levofloxacin is a good alternative in the treatment of H. pylori infections, especially in regions with high prevalence of H. pylori strains resistant to clarithromycin (> 20%)

Comparative "in vitro" studies of furazidin and nitrofurantoin activities against common uropathogens including multidrug-resistant strains of "E. coli" and "S. aureus"

Urinary tract infections caused by wide range of pathogens including gram-negative andgram-positive bacteria as well as fungi are a severe public health problem. The predominant causative agent of both uncomplicated and complicated urinary tract infections is Escherichia coli. In an era of increasing bacterial resistance to antimicrobial agents and a high prevalence of multidrug-resistant (MDR) strains in communityandhospital-acquired infections, the re-evaluation of older generations of antimicrobial agents, such as nitrofuran derivatives, seems to be a reasonable approach. The aim of the study was to evaluate furazidin activity against common uropathogens in comparison to nitrofurantoin and other selected antimicrobial agents, routinely used in the treatment of urinary tract infections. Furazidin exhibited lower MICs than nitrofurantoin when tested against gram-negative and gram-positive bacteria including clinical MDR E. coli and methicillin-resistant Staphylococcus aureus. The MICs for furazidin ranged from 4 to 64 mg/L forEnterobacteriaceae strains, from 2 to 4 mg/L for gram-positive cocci, and 0.5 mg/L for anaerobic bacteria. The MICs for nitrofurantoin ranged from 16 to 64 mg/L for Enterobacteriaceae strains, from 8 to 64 mg/L for gram positive cocci, and 4 mg/L for anaerobic bacteria. In addition, both nitrofurans displayed better activity against the tested bacterial strains than ciprofloxacin, fosfomycin, trimethoprim and co-trimoxazole. Nitrofuran derivatives displayed higher antimicrobial activity than other antimicrobial agents regardless of bacteria species or resistance mechanism

European aerosol phenomenology - 8 : Harmonised source apportionment of organic aerosol using 22 Year-long ACSM/AMS datasets

Organic aerosol (OA) is a key component of total submicron particulate matter (PM1), and comprehensive knowledge of OA sources across Europe is crucial to mitigate PM1 levels. Europe has a well-established air quality research infrastructure from which yearlong datasets using 21 aerosol chemical speciation monitors (ACSMs) and 1 aerosol mass spectrometer (AMS) were gathered during 2013-2019. It includes 9 non-urban and 13 urban sites. This study developed a state-of-the-art source apportionment protocol to analyse long-term OA mass spectrum data by applying the most advanced source apportionment strategies (i.e., rolling PMF, ME-2, and bootstrap). This harmonised protocol was followed strictly for all 22 datasets, making the source apportionment results more comparable. In addition, it enables quantification of the most common OA components such as hydrocarbon-like OA (HOA), biomass burning OA (BBOA), cooking-like OA (COA), more oxidised-oxygenated OA (MO-OOA), and less oxidised-oxygenated OA (LO-OOA). Other components such as coal combustion OA (CCOA), solid fuel OA (SFOA: mainly mixture of coal and peat combustion), cigarette smoke OA (CSOA), sea salt (mostly inorganic but part of the OA mass spectrum), coffee OA, and ship industry OA could also be separated at a few specific sites. Oxygenated OA (OOA) components make up most of the submicron OA mass (average = 71.1%, range from 43.7 to 100%). Solid fuel combustion-related OA components (i.e., BBOA, CCOA, and SFOA) are still considerable with in total 16.0% yearly contribution to the OA, yet mainly during winter months (21.4%). Overall, this comprehensive protocol works effectively across all sites governed by different sources and generates robust and consistent source apportionment results. Our work presents a comprehensive overview of OA sources in Europe with a unique combination of high time resolution (30-240 min) and long-term data coverage (9-36 months), providing essential information to improve/validate air quality, health impact, and climate models.Peer reviewe