University of Wroclaw
  • Wrocław, Lower Silesia, Poland
Recent publications
Nontronite is a swelling clay mineral. Between the layers, it contains water and cations. Nontronite can be easily modified by intercalation. This work focuses on characterizing unmodified nontronite and nontronite intercalated with formamide. Thermal measurements, infrared spectroscopy, X–ray diffraction, and dielectric relaxation measurements were made to evaluate the interactions of the guest molecules with the host layers. A startling effect was observed in dielectric experiments: the low–frequency permittivity detected in nontronite was much larger than in the material intercalated with formamide, the molecule with a high dipole moment. To explain this effect, it was assumed that the low–frequency dielectric relaxation was associated with the movement of interlayer ions. Dehydration of nontronite, which is a stage of preparation for intercalation, can probably fix some ions in hexagonal cavities (privileged positions). Subsequent intercalation of nontronite by formamide does not bring back the mobility of ions, and the low–frequency electric permittivity remains relatively low. To achieve mobility of the cations, an expansion of the interlayer space is required, and ion–dipole interactions with guest molecules should be present.
The Middle Pleistocene was a period of dynamic changes in Europe. During MIS 11, a number of modern mammal taxa appeared and environmental conditions remained warm and favourable for a relatively long time. The Medzhybizh 1 locality of Ukraine dated to this very period comprises alluvial deposits with rich animal remains, which allow not only to reconstruct the fauna composition, but also to highlight the environmental conditions that dominated at this locality. A revision of the fauna of Medzhybizh 1 locality based on remains of all vertebrate groups revealed a taxonomically diverse fish community (16 species of 11 genera) dominated by cyprinids common for lacustrine or riverine assemblages. Amphibians are represented by 11 species, while the number of reptile and bird remains are less significant. Mammals are the most represented group at the locality, including small mammals (30 species), carnivorans (2 species), and ungulates (5 taxa), the latter dominated by C. elaphus. The taxonomic composition of terrestrial groups indicates temperate climate with boreal-type forests and meadows similar to cold steppe, as well as low wet areas and riparian habitats inhabited by amphibians, reptiles, insectivores, beavers, and various voles. The fish assemblage indicates a partially overgrown but well-aerated water body (lake or slow-flowing river) with sandy-silty bottom. Lithic artefacts found at the Medzhybizh 1 locality contribute to a better understanding of relationships between ancient hominins and faunas during the Middle Pleistocene of Eastern Europe.
Objective This systematic review and meta-analysis aimed to analyze and synthesize the evidence on the effectiveness of virtual reality (VR) interventions in the prevention of pain, fear and anxiety during burn wound care procedures. Methods In September and October 2021, PubMed, Scopus, Cochrane Library and Web of Science were searched for relevant randomized controlled and crossover studies. Two independent authors described the following inclusion criteria for the search: patients undergoing burn wound care with applied VR treatment compared to any other or non-VR intervention. From a total of 1171 records, 25 met the inclusion criteria. After full-text screening, seven publications were excluded. The risk of bias was assessed for 18 studies by two independent authors. RevMan 5.4 was used for the statistical analysis, meta-analysis and visual presentation of the results. Results The meta-analysis showed a significant difference between VR treatment and standard care when analyzing pain outcome during wound care procedures (SMD = −0.49; 95% CI [−0.78, −0.15]; I² = 41%) and in subgroup analysis when immersive VR was incorporated (SMD = −0.71; 95% CI [−1.07, −0.36]; I² = 0%). No significant differences were found between VR treatment and standard care for range of motion outcome (SMD = 0.44; 95% CI [−0.23, 1.11]; I² = 50%). Conclusions VR seems to be an effective therapeutic support in burn wound care procedures for reducing pain. However, this systematic review and meta-analysis highlights the need for more research into the use of VR as a distraction method. Studies on larger groups using similar conditions can provide unequivocal evidence of the effectiveness of VR and enable the inclusion of such intervention in standard medical procedures.
The complementary sex determiner ( csd ) gene is responsible for controlling the sex-determination molecular switch in western honey bees ( Apis mellifera ): bees that are heterozygous for csd develop into females, whereas bees that are hemizygous or homozygous develop into males. The homozygous diploid males are destroyed at an early stage of their development. It has been proposed that the minimal number of amino acid differences between two csd alleles needed to fully determine femaleness is five and it has also been shown that smaller differences may result in forming an evolutionary intermediate that is not fully capable of female determination, but has increased fitness compared to the homozygous genotype. In this study, we have implemented a terminal restriction length polymorphism-based method of identifying and distinguishing paternal alleles in a given bee colony and assigning them to a particular maternal allele in order to gather information on large number of functional csd pairs and also to identify, to some extent, genotypes that are underrepresented or absent in bee colonies. The main finding of this study is the identification of a fully functional genotype consisting of csd alleles that differed from each other by a one amino acid position. The individuals carrying this genotype expressed only female-specific transcripts of feminizer and double-sex genes. By comparing the sequences differences between the csd pair identified in our study with those described earlier, we conclude that functional heterozygosity of the csd gene is dependent not only on the number of the amino acid differences but also on the sequence context and position of the change. The discovery of a functional allele pair differing by a single amino acid also implies that the generation of a new csd specificity may also occur during a single mutation step with no need for evolutionary intermediates accumulating further mutations.
Modern solutions in water distribution systems are based on monitoring the quality and quantity of drinking water. Identifying the volume of water consumption is the main element of the tools embedded in water demand forecasting (WDF) systems. The crucial element in forecasting is the influence of random factors on the identification of water consumption, which includes, among others, weather conditions and anthropogenic aspects. The paper proposes an approach to forecasting water demand based on a linear regression model combined with evolutionary strategies to extract weekly seasonality and presents its results. A comparison is made between the author's model and solutions such as Support Vector Regression (SVR), Multilayer Perceptron (MLP), and Random Forest (RF). The implemented daily forecasting procedure allowed to minimize the MAPE error to even less than 2% for water consumption at the water supply zone level, that is the District Metered Area (DMA). The conducted research may be implemented as a component of WDF systems in water companies, especially at the stage of data preprocessing with the main goal of improving short-term water demand forecasting.
A conventional free-electron laser is useful but large, driven by a beam with many relativistic electrons. Although, recently, keV electron beams have been used to excite broadband radiation from material chips, there remains a quest for a chip-size free-electron laser capable of emitting coherent radiation. Unfortunately, those keV emitters from electron microscopes or dielectric laser accelerator usually deliver a small current with discrete moving electrons separated by a distance of a few or tens of microns. To envisage a chip-size free-electron laser as a powerful research tool, we study in this paper achievable laser radiation from a single electron and an array of single electrons atop a nano-grating dielectric waveguide. In our study, thanks to the strong coupling between the electron and the guided wave in a structure with distributed feedback, a single 50-keV electron generates 1.5-μm laser-like radiation at the Bragg resonance of a 31-μm long silicon grating with a 400-nm thickness and 310-nm period. When driven by a train of single electrons repeating at 0.1 PHz, the nano-grating waveguide emits a strong laser radiation at the second harmonic of the excitation frequency. A discrete spectrum of Smith-Purcell radiation mediated by the waveguide modes is also predicted in theory and observed from simulation in the vacuum space above the grating waveguide. This study opens up the opportunity for applications requiring combined advantages from compact high-brightness electron and photon sources.
Background Although the definition of food addiction is not agreed upon, it is characterized by eating more than expected without being hungry, not being able to visit certain places associated with overeating or unsuccessfully trying to cut down on the consumption of certain foods. The modified YFAS (mYFAS 2.0) version, instrument available to evaluate food addiction, was shown to have good psychometric properties. Our objective was to assess the psychometric properties of the Arabic version of the mYFAS (mYFAS-Ar-Leb) in the Lebanese population. Methods This cross-sectional study enrolled 1268 persons residing in Lebanon (September–November 2020). The mean age of the participants was 26.18 years (SD = 11.17; min: 18; max: 85), with 65.1% females. The percentage of participants with food addiction was 226 (17.8%) in the total sample. A confirmatory factor analysis was run on the one-factor structure among the total sample. Results The fit indices of the confirmatory factor analysis of the scale were excellent. The Cronbach’s alpha value was good for the total scale. The mYFAS-Ar-Leb score was positively and strongly associated with stress, anxiety and depression. Conclusion Our study findings highlighted that the use of the mYFAS-Ar-Leb in Lebanese population might help estimate food addiction prevalence and stress on the need for effective treatment and preventive measures to craving for addictive foods.
Nucleotide sugars (NSs) serve as substrates for glycosylation reactions. The majority of these compounds are synthesized in the cytoplasm, whereas glycosylation occurs in the endoplasmic reticulum (ER) and Golgi lumens, where catalytic domains of glycosyltransferases (GTs) are located. Therefore, translocation of NS across the organelle membranes is a prerequisite. This process is thought to be mediated by a group of multi-transmembrane proteins from the SLC35 family, i.e., nucleotide sugar transporters (NSTs). Despite many years of research, some uncertainties/inconsistencies related with the mechanisms of NS transport and the substrate specificities of NSTs remain. Here we present a comprehensive review of the NS import into the mammalian Golgi, which consists of three major parts. In the first part, we provide a historical view of the experimental approaches used to study NS transport and evaluate the most important achievements. The second part summarizes various aspects of knowledge concerning NSTs, ranging from subcellular localization up to the pathologies related with their defective function. In the third part, we present the outcomes of our research performed using mammalian cell-based models and discuss its relevance in relation to the general context.
Systems consisting of a single ordinary differential equation coupled with one reaction-diffusion equation in a bounded domain and with the Neumann boundary conditions are studied in the case of particular nonlinearities from the Brusselator model, the Gray-Scott model, the Oregonator model and a certain predator-prey model. It is shown that the considered systems have the both smooth and discontinuous stationary solutions, however, only discontinuous ones can be stable.
Aims The aim of the study was to investigate N biogeochemistry of four neighboring, high mountain plant communities and to identify main factors which drive variability among them. We hypothesized that the vegetation types differ in terms of N transformations, and that spatial differentiation of the communities and dominant growth form can reflect an existence of several N-environments along an elevational gradient. Methods Plant and soil N characteristics were studied in four vegetation types: heathland, scrub, sward and tall forb. Leaf nitrate reductase activity and total N were measured in the dominant species. Soil pH, total C, N, inorganic and dissolved organic N concentrations were measured. The soil net N mineralization rate was examined. Results The DistLM and PERMANOVA analyses revealed that variability among the vegetation types was driven primarily by elevation, soil N–NH 4 ⁺ , soil pH and soil total C. We identified three distinct N-environments along an elevational gradient. The “N-poor alpine” located at the highest altitudes, strongly N-limited and dominated by dwarf-shrub. The "N-mixed subalpine" located in the middle of the gradient and covered by scrub and sward. It was characterized by moderate N turnover rate. The "N-rich subalpine" occurred at lowest locations and was covered by subalpine tall forb community. It exhibited the highest dynamics of N transformations and was rich in inorganic N. Conclusion Three main N-environments were identified: N-poor alpine, N-mixed subalpine, N-rich subalpine. Variability among the vegetation types was driven primarily by elevation, soil N–NH 4 ⁺ , soil pH and soil total C.
Invited for the cover of this issue is the group of Ewa Pacholska‐Dudziak at the University of Wroclaw. The image depicts two rhodium atoms being fixed into the skeleton of 21,23‐dirhodaporphyrin in place of two core nitrogen donors. Read the full text of the article at 10.1002/chem.202201513. “The compound was initially thrown away because of its uninteresting, “nonporphyrin” color, which indicated impurities.” This and more about the story behind the front cover can be found in the article at 10.1002/chem.202201513).
Pure red fluorescence generated by near infrared (NIR) excitation is desired for bio-imaging with high biological penetration, but without cell damage or multi-photon photo-toxicity. In this work, β-NaYF4:Er³⁺ and β-NaYF4:Er³⁺,Tm³⁺ microcrystals were synthesized using a novel hydrothermal method. β-NaYF4:Er³⁺ microcrystals exhibited intense green and red up-conversion emissions under 976 nm laser diode excitation. The introduction of Tm³⁺ ions into β-NaYF4:Er³⁺ resulted in strong inhibition of green up-conversion emission (Er³⁺:²H11/2 /⁴S3/2→⁴I15/2) and, consequently, red up-conversion emission (Er³⁺:⁴F9/2→⁴I15/2) was significantly promoted. To simultaneously restrain green up-conversion emissions and enhance red up-conversion emissions, the optimal concentrations of Er³⁺ and Tm³⁺ ions were determined to be 20 mol% and 2.0 mol%, respectively. The red/green up-conversion emission intensity ratio increased from ~1.80 (β-NaYF4:20Er³⁺, mol%) to ~78 (β-NaYF4:20Er³⁺,2Tm³⁺, mol%) after the addition of 2 mol% Tm³⁺ ions to β-NaYF4:20Er³⁺ (mol%). The red up-conversion emission intensity of β-NaYF4:20Er³⁺,2Tm³⁺ was stronger than that for commercial red up-conversion phosphors (NaYF4 and ZnF2) under the same experimental conditions. Based on the results of the emission spectra, luminescence rise, and decay profiles, the mechanism of enhanced red up-conversion emission by Tm³⁺ ion co-doping in β-NaYF4:20Er³⁺,2Tm³⁺ (mol%) was proposed. The bio-fluorescence experiment under NIR excitation proves that β-NaYF4:Er³⁺,Tm³⁺ microcrystals have potential applications in bio-imaging.
5‐isopropyl 4‐(2‐Chlorophenyl)‐1‐ethyl‐1,4‐dihydro‐6‐methyl‐2,3,5‐pyridinetricarboxylic ester disodium salt hydrate, is a noncompetitive inhibitor of glycogen phosphorylase – a critical enzyme in the process of glycogenolysis. This chemical compound is most widely used in studies focused on the inhibition of liver and muscle glycogenolysis. However, there are also reports linking phosphorylase inhibitor action with cognitive function and glycogen metabolism in the brain. The aim of this study was to develop and validate the liquid chromatography mass spectrometry method for quantitative analysis of present chemical compound in mouse tissues including different brain regions. Obtained linearity was in the range of 10–550 ng/ml with a correlation coefficient: 0.9996. In tissue matrix samples the limit of detection was 7.76 ng/ml, while the limit of quantification was 23.29 ng/ml. The coefficient of variation values did not exceed ± 15% for either within run or between run precision quality control samples. Extraction recovery was between 89.44% and 98.70% for various validation analyte concentrations. The present method was successful in quantitative determination of presented analyte in mouse tissues and provided evidence that the compound is not only present in liver, heart, and skeletal muscle but also in different regions of brain tissue such as: hippocampus, cerebellum, cortex. This article is protected by copyright. All rights reserved
Precise anticancer therapies employing cytotoxic conjugates constitute a side-effect-limited, highly attractive alternative to commonly used cancer treatment modalities, such as conventional chemotherapy, radiotherapy or surgical interventions. Receptor tyrosine kinases are a large family of N-glycoproteins intensively studied as molecular targets for cytotoxic conjugates in various cancers. At the cell surface, these receptors are embedded in a dense carbohydrate layer formed by numerous plasma membrane glycoproteins. The complexity of the cell surface architecture is further increased by galectins, secreted lectins capable of recognizing and clustering glycoconjugates, affecting their motility and activity. Cell surface N-glycosylation is intensively remodeled by cancer cells; however, the contribution of this phenomenon to the efficiency of treatment with cytotoxic conjugates is largely unknown. Here, we evaluated the significance of N-glycosylation for the internalization and toxicity of conjugates targeting two model receptor tyrosine kinases strongly implicated in cancer: HER2 and FGFR1. We employed three conjugates of distinct molecular architecture and specificity: AffibodyHER2-vcMMAE (targeting HER2), vcMMAE-KCK-FGF1.E and T-Fc-vcMMAE (recognizing different epitopes within FGFR1). We demonstrated that inhibition of N-glycosylation reduced the cellular uptake of all conjugates tested and provided evidence for a role of the galectin network in conjugate internalization. In vitro binding studies revealed that the reduced uptake of conjugates is not due to impaired HER2 and FGFR1 binding. Importantly, we demonstrated that alteration of N-glycosylation can affect the cytotoxic potential of conjugates. Our data implicate a key role for cell surface N-glycosylation in the delivery of cytotoxic conjugates into cancer cells
The Linguistic and Cultural Image of the Urban Space of Moscow in the Late Nineteenth and Early Twentieth Centuries (on the Basis of V. Elistratov’s Dictionary) The aim of this article is to reconstruct the linguistic and cultural image of Moscowat the turn of the twentieth century using the paradigm of cultural linguistics. This paradigm was selected as the theoretical framework of the study considering that it practically has not been applied in Russian linguistics. The article shows that the intricate image of the urban space is created by means of cultural elements (the coat of arms, the flag, the bugle call, architecture) and, most of all, linguistic elements whose major exponent is a given urban dialect. It is a wide-ranging construct whose lexis, apart from native elements, also includes a large number of foreign components and proprial (official and unofficial) vocabulary. The conglomerate of these elements can be regarded as a specific language of the urban space. Językowo-kulturowy obraz przestrzeni miejskiej Moskwy na przełomie XIX i XX wieku (na bazie słownika W. Jelistratowa) Artykuł podejmuje się rekonstrukcji językowo-kulturowych elementów przestrzeni miejskiej Moskwy w aspekcie diachronicznym (przełom XIX i XX wieku) przy użyciu metod lingwistyki kulturowej. Zasadność wyboru tego paradygmatu wynika z faktu, iż na gruncie językoznawstwa rosyjskiego nie jest on uprawiany. Artykuł pokazuje, że na skomplikowany obraz przestrzeni miejskiej składają się aspekty kulturowe (architektura, herb, hejnał, flaga), a przede wszystkim językowe (dialekt miejski, zapożyczenia obce, nieoficjalna urbanonimia). Wszystkie te elementy tworzą uniwersalny język przestrzeni, który może być zestawiany z innymi miastami Słowiańszczyzny.
Across five studies (total N > 3,600), we report the psychometric properties of the Polish version of the Vividness of Visual Imagery Questionnaire (VVIQ-2PL). Confirmatory factor analysis confirmed a unidimensional structure of this instrument; measurement invariance concerning participants’ gender was established as well. The VVIQ-2PL showed excellent test-retest reliability, high internal consistency, and adequate construct validity. As predicted, art students scored significantly higher in visual mental imagery than the non-artist group. We discuss these findings alongside future research directions and possible modifications of VVIQ-2PL.
In this paper, the photochemistry of glyoxal–hydroxylamine (Gly–HA) complexes is studied using FTIR matrix isolation spectroscopy and ab initio calculations. The irradiation of the Gly–HA complexes with the filtered output of a mercury lamp (λ > 370 nm) leads to their photoconversion to hydroxyketene–hydroxylamine complexes and the formation of hydroxy(hydroxyamino)acetaldehyde with a hemiaminal structure. The first product is the result of a double hydrogen exchange reaction between the aldehyde group of Gly and the amino or hydroxyl group of HA. The second product is formed as a result of the addition of the nitrogen atom of HA to the carbon atom of one aldehyde group of Gly, followed by the migration of the hydrogen atom from the amino group of hydroxylamine to the oxygen atom of the carbonyl group of glyoxal. The identification of the products is confirmed by deuterium substitution and by MP2 calculations of the structures and vibrational spectra of the identified species.
This paper deals with Gärdenfors’ theory of conceptual spaces. Let $${\mathcal {S}}$$ S be a conceptual space consisting of 2-type fuzzy sets equipped with several kinds of metrics. Let a finite set of prototypes $$\tilde{P}_1,\ldots ,\tilde{P}_n\in \mathcal {S}$$ P ~ 1 , … , P ~ n ∈ S be given. Our main result is the construction of a classification algorithm. That is, given an element $${\tilde{A}}\in \mathcal {S},$$ A ~ ∈ S , our algorithm classifies it into the conceptual field determined by one of the given prototypes $$\tilde{P}_i.$$ P ~ i . The construction of our algorithm uses some physical analogies and the Newton potential plays a significant role here. Importantly, the resulting conceptual fields are not convex in the Euclidean sense, which we believe is a reasonable departure from the assumptions of Gardenfors’ original definition of the conceptual space. A partitioning algorithm of the space $$\mathcal {S}$$ S is also considered in the paper. In the application section, we test our classification algorithm on real data and obtain very satisfactory results. Moreover, the example we consider is another argument against requiring convexity of conceptual fields.
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7,336 members
Przemyslaw Dopieralski
  • Faculty of Chemistry
Piotr Stefanowicz
  • Faculty of Chemistry
Marta Borowiec
  • Faculty of Biological Sciences
Rafał Ogórek
  • Department of Mycology and Genetics
plac Uniwersytecki 1, 50-137, Wrocław, Lower Silesia, Poland
Head of institution
prof. dr hab. Przemysław Wiszewski
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