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result(s) for
"Kwiatkowski, Paweł"
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The molecular population structure of Swertia perennis (Gentianaceae) in Central Europe
2023
Phylogeographic analysis of
Swertia perennis,
a typical European subalpine springtime species, revealed the existence of at least five major phylogenetic lineages. A large phylogeographic separation exists among these geographical regions, which confirms the existence of glacial refugia in the Pyrenees, but also in the Eastern and Central Alps. The results obtained from the analyzes indicate the existence of three major differences between the populations of the Alps and the Pyrenees, but also between the populations of the Alps and those of other geographical regions (Carpathians, southern Czech Republic, Sudetes and northern Poland). The studied populations from the Black Forest and from north-eastern and southern Poland are a relic of the former wider distribution of these (periglacial) genetic groups within Swertia perennis. Our results also confirm the existence of biogeographical links between the Carpathians and the Hercynian Range and the Alps. Certainly, there was an exchange of genes between populations located in the eastern Alps, the Carpathians and the Hercynian ranges (Czech Republic, Jeseníky, Sudetes, Ore Mountains). This confirms previous results of comparative studies on the genetic diversity of populations of other vascular plant species.
Journal Article
Employing FPGA DSP blocks for time-to-digital conversion
2019
The paper presents a novel implementation of a time-to-digital converter (TDC) in field-programmable gate array (FPGA) devices. The design employs FPGA digital signal processing (DSP) blocks and gives more than two-fold improvement in mean resolution in comparison with the common conversion method (carry chain-based time coding line). Two TDCs are presented and tested depending on DSP configuration. The converters were implemented in a Kintex-7 FPGA device manufactured by Xilinx in 28 nm CMOS process. The tests performed show possibilities to obtain mean resolution of 4.2 ps but measurement precision is limited to at most 15 ps mainly due to high conversion nonlinearities. The presented solution saves FPGA programmable logic blocks and has an advantage of a wider operation range when compared with a carry chain-based time coding line.
Journal Article
Basaltic Outcrops as Centers of Diversity for Xerothermic Plants in the Sudetes Mountains (Central Europe)
2021
Rock outcrops have promoted a high level of species diversity and provided a stable microclimate for long time periods. The present study is devoted to plant diversity of natural Quaternary outcrops of basaltic rocks. Chorological and ecological investigations were carried out at 35 such outcrops, located within five physiogeographic units of the Sudetes Mountains. The focus was on 120 xerothermic taxa of vascular plants: 62 strictly xerothermic (steppe) taxa of the Festuco valesiacae-Brometea erecti class, and 58 thermophilous taxa representing classes Trifolio medii-Geranietea sanguinei and Quercetea pubescentis. Limited geographical ranges of these plants are manifested by variable frequency of their occurrence. Species distribution is determined by natural factors, like surface area of the outcrop, the type of basaltic rock and the type of plant communities developed. Basaltic outcrops in the Sudetes meet the criterion of habitat islands (inselbergs), serve as regional centers of vascular flora, and are refugia for marginal populations of relict species.
Journal Article
Plant Taxonomy, Systematics and Phylogeography
2024
Plant taxonomy and phylogeny deal with very important problems related to the genetic diversity of populations found in different geographical regions, trying to present the variability of these populations but also to explain their origin. For this reason, such studies examining the conditioned diversity of plant populations were the subject of this Special Issue (SI) of the journal Plants. This SI contains ten original articles and one review article concerning phylogeography and related sciences, i.e., biogeography, taxonomy, and systematics, as well as the genetic variability that lies at the basis of these sciences. The articles included in the SI cover a wide range of topics, including the phylogeny and taxonomy of mosses, taxonomy and hybridization and phylogeny of the genus Chery, genetic diversity and phylogeography of fern, including relict species from the Macronesia area, taxonomy of the genus Aconitum, a species of orchid new to the Romanian flora, but also a proposal for a new phylogeographic division in Gansu Province (China) and a review of the role of the Hercynian Mountains in Shaping Plant Migration Patterns in the Pleistocene.
Journal Article
The Antibacterial Activity of Lavender Essential Oil Alone and In Combination with Octenidine Dihydrochloride against MRSA Strains
by
Sienkiewicz, Monika
,
Wojciuk, Bartosz
,
Kostek, Mateusz
in
Antibiotics
,
Drug Synergism
,
Drug Therapy, Combination
2019
In the post-antibiotic era the issue of bacterial resistance refers not only to antibiotics themselves but also to common antiseptics like octenidine dihydrochloride (OCT). This appears as an emerging challenge in terms of preventing staphylococcal infections, which are both potentially severe and easy to transfer horizontally. Essential oils have shown synergisms both with antibiotics and antiseptics. Therefore the aim of this study was to investigate the impact of lavender essential oil (LEO) on OCT efficiency towards methicillin-resistant S. aureus strains (MRSA). The LEO analyzed in this study increased the OCT’s susceptibility against MRSA strains. Subsequent FTIR analysis revealed cellular wall modifications in MRSA strain cultured in media supplemented with OCT or LEO/OCT. In conclusion, LEO appears to be a promising candidate for an efficient enhancer of conventional antiseptics.
Journal Article
Composition and Activities of Carpesium macrocephalum Franch. & Sav. Essential Oils
by
Malarz, Janusz
,
Kwiatkowski, Paweł
,
Stojakowska, Anna
in
alantolactone
,
Analysis
,
Anti-Bacterial Agents - chemistry
2024
Carpesium macrocephalum, a species native to China, Korea, Japan, and Russia, has been used medicinally in the countries of its origin. Though mono- and sesquiterpenoids are known constituents of C. macrocephalum, the complete analysis of essential oils produced by the roots and aerial parts of the plant has not been published until now. The present study discloses considerable differences in the composition and cytotoxic activity of essential oils distilled from roots and shoots of C. macrocephalum. The GC-MS-FID analyses have led to the identification of 131 compounds in all, of which 114 were found in aerial parts and 110 in the roots of the plants. The essential oil distilled from shoots contained a mixture of nerol and thymol methyl ether (c. 26%), neryl isobutyrate (c. 12%) and linalool (c. 9%) as major constituents, whereas alantolactone (c. 29%), thymol methyl ether (c. 7%) and 2,5-dimethoxy-p-cymene (thymohydroquinone dimethyl ether, c. 7%) predominated in the essential oil obtained from the roots. The oils demonstrated weak antibacterial activity against Staphylococcus aureus and, at concentrations up to 2.08 mg/mL (oil from the aerial parts) and up to 3.38 mg/mL (oil from roots), were inactive against Gram-negative bacteria. The essential oil from the roots of the plant demonstrated strong but not selective cytotoxic activity.
Journal Article
The Role of the Hercynian Mountains of Central Europe in Shaping Plant Migration Patterns in the Pleistocene—A Review
2023
The climatic changes that took place in Europe during the Quaternary period influenced plant habitats as well as their species and vegetation composition. In this article, biogeographical studies on Hercynian mountain plants that include data for the Alps, Carpathians, and European lowlands are reviewed in order to discuss the phylogeographical structure and divergence of the Hercynian populations from those in other European mountain ranges, Scandinavia, and lowlands. The analyzed studies show specific phylogeographical relations between the Hercynian mountains, Alps, Scandinavia, Carpathians, and European lowlands. The results also indicate that the genetic patterns of plant populations in the Hercynian Mountains may differ significantly in terms of origin. The main migration routes of species to the Hercynian ranges began in the Alps or Carpathians. Some species, such as Rubus chamaemorus L., Salix lapponum L., and Salix herbacea L., are glacial relics that may have arrived and settled in the Hercynian Mountains during the Ice Age and that survived in isolated habitats. The Hercynian Mountains are composed of various smaller mountain ranges and are a crossroads of migration routes from different parts of Europe; thus, intensive hybridization has occurred between the plant populations therein, which is indicated by the presence of several divergent genetic lines.
Journal Article
The Effect of Fermentation with Kefir Grains on the Physicochemical and Antioxidant Properties of Beverages from Blue Lupin (Lupinus angustifolius L.) Seeds
by
Sienkiewicz, Monika
,
Gefrom, Annett
,
Drozłowska, Emilia
in
Amino Acids - metabolism
,
Antioxidants - chemistry
,
Antioxidants - pharmacology
2020
Plant derived fermented beverages have recently gained consumers’ interest, particularly due to their intrinsic functional properties and presence of beneficial microorganisms. Three variants containing 5%, 10%, and 15% (w/w) of sweet blue lupin (Lupinus angustifolius L. cv. “Boregine”) seeds were inoculated with kefir grains and incubated at 25 °C for 24 h. After processing, beverages were stored in refrigerated conditions (6 °C) for 21 days. Changes in microbial population, pH, bioactive compounds (polyphenolics, flavonoids, ascorbic acid), reducing sugars, and free amino acids were estimated. Additionally, viscosity, firmness, color, and free radicals scavenging properties were determined. Results showed that lactic acid bacteria as well as yeast were capable of growing well in the lupin matrix without any supplementation. During the process of refrigeration, the viability of the microorganisms was over the recommended minimum level for kefir products. Hydrolysis of polysaccharides as well as increase of free amino acids was observed. As a result of fermentation, the beverages showed excellent DPPH, ABTS+·, ·OH, and O2− radicals scavenging activities with a potential when considering diseases associated with oxidative stress. This beverages could be used as a new, non-dairy vehicle for beneficial microflora consumption, especially by vegans and lactose-intolerant consumers.
Journal Article
Comparative analysis of selected methods of carbapenemase determination among clinical Klebsiella pneumoniae
by
Skierska, Alicja
,
Sienkiewicz, Monika
,
Melnyk, Maria V
in
Analysis
,
Anti-Bacterial Agents - pharmacology
,
Bacterial Proteins - genetics
2025
Klebsiella pneumoniae is a typical opportunistic pathogen that exhibits multiple virulence factors and antibiotic resistance conditioning mechanisms. Carbapenemases are enzymes that help bacteria to exhibit the strongest resistance against antibiotics. Therefore, in routine microbiological diagnoses, it is crucial to confirm antibiotic-resistant strains, including carbapenemase-producing bacteria strains, isolated from patients. Two types of tests play an important role here: phenotypicand molecular diagnostic methods. The latter complement phenotypic tests and a mandatory procedure to confirm the detection of carbapenemases. This study aimed to evaluate the usefulness and effectiveness of tests and methods used to identify and confirm the ability of clinical K. pneumoniae strains to produce carbapenemases. The production of carbapenemases was assessed using phenotypic and genetic methods. The strains tested showed complete resistance to most beta-lactams and varying sensitivity to drugs from the quinolone carbapenem group and aminoglycosides. Among the most commonly produced carbapenemases were the metallo-beta-lactamase (NDM) family. The most accurate phenotypic method for detecting carbapenemases was the NG CARBA-5 assay, and the PCR method confirmed these results. Notably, a few inconclusive results were obtained for NDM-positive and VIM-positive strains when the disk diffusion method and CIM test were used. Further, the Carba tube assay and the RAPIDEC CARBA NP assay produced questionable results for the OXA-48 strain group. This group also generated false-negative results on Carba's CHROM ID medium.
Journal Article
Evaluation of Colistin Susceptibility of Klebsiella pneumoniae Strains Exposed to Rotating Magnetic Field
by
Kwiatkowski, Paweł
,
Kobylińska, Dagmara
,
Pruss, Agata
in
Analysis
,
Anti-Bacterial Agents - pharmacology
,
Antibacterial agents
2025
Klebsiella pneumoniae, due to its capacity to produce numerous virulence factors and form biofilms, is one of the most significant etiological agents of nosocomial infections. The extensive and often unwarranted use of antibiotic therapy has driven the emergence of various mutations, adaptive mechanisms, and horizontal gene transfer among K. pneumoniae strains, resulting in resistance to most beta-lactam antibiotics, carbapenems, and the last-resort drug—colistin. A promising alternative or adjunctive treatment is the application of rotating magnetic fields (RMFs). The present study aimed to evaluate changes in colistin susceptibility among 20 extended-spectrum beta-lactamases (ESBLs) and 20 K. pneumoniae carbapenemase (KPC)-positive K. pneumoniae strains isolated from hospital infections following exposure to RMF at frequencies of 5 and 50 Hz. Exposure to RMF at 5 Hz resulted in decreased colistin minimum inhibitory concentration (MIC) values in over half of the tested (ESBLs) and (KPC)-positive strains. Additionally, RMF at 50 Hz reduced colistin MIC values in 30% of (ESBL)-positive and 40% of (KPC)-positive strains. Therefore, in the future, RMF may be developed as a supportive therapeutic strategy to improve the efficacy of antibiotics in the treatment of infections caused by multidrug-resistant (MDR) pathogens, including colistin-resistant K. pneumoniae.
Journal Article