Repozytorium Uniwersytetu Śląskiego RE-BUŚ
Not a member yet
23505 research outputs found
Sort by
Tribological properties of Al2O3 layers after thermo-chemical treatment
Get PDFThe article presents the influence of the thermo-chemical treatment of Al2O3 layers on their tribological proper-ties. The Al2O3 layers were produced on the EN AW-5251 aluminium alloy by means of direct current anodizing in a three-component electrolyte. For the sake of comparison, some of the samples were thermochemically treated in three liquids (sodium sulphate solution, sodium dichromate solution, distilled water). The parameters of the pro-duction and thermo-chemical treatment were selected on the basis of two Hartley's plans. The tribological proper-ties were determined on the basis of a tribological test carried out for a pin-on-disc friction pair on a T-17 tester in reciprocating motion. The tests were carried out in conditions of technically dry friction. Thanks to the tests, coeffi-cient of friction µ and the mass wear, together with the intensity of the material wear were determined. The use of thermo-chemical treatment in the sodium dichromate solution contributed to an increase in coefficient of friction μ and a reduction in the wear intensity of the polymer from 36 μg/km (layer without thermo-chemical treatment) to 21.33 μg/km (layer after thermo-chemical treatment in the sodium dichromate solution).The conducted stereomet-ric tests before and after the tribological test for selected samples allow the authors to state that the thermo-chemical treatment in the sodium dichromate solution increases the amplitude parameters of surface roughness. The study of the surface morphology of the layer with the lowest mass wear showed the formation of an additional sub-layer as a result of thermo-chemical treatment carried out in the sodium dichromate solution
Plant association with dark septate endophytes: When the going gets tough (and stressful), the tough fungi get going
Get PDFDark septate endophytes (DSEs) comprise a diverse and ubiquitous group of fungal generalists with broad habitat niches that robustly colonize the roots of plants in stressful environments. DSEs possess adaptation strategies that determine their high tolerance to heavy metal (HM) contamination, drought, and salinity. Most DSEs developed efficient melanin-dependent and melanin-independent mechanisms of HM detoxification and osmoprotection, including intracellular immobilization and extracellular efflux of HMs and excess ions, and the scavenging of reactive oxygen species. DSEs form mutualistic relationship with plants according to the hypothesis of “habitatadapted associations”, supporting the survival of their hosts under stressful conditions. As saprophytes, DSEs mineralize a complex soil substrate improving plants’ nutrition and physiological parameters. They can protect the host plant from HMs by limiting HM accumulation in plant tissues and causing their sequestration in root cell walls as insoluble compounds, preventing further HM translocation to shoots. The presence of DSE in droughtaffected plants can substantially ameliorate the physiology and architecture of root systems, improving their hydraulic properties. Plant growth-promoting features, supported by the versatility and easy culturing of DSEs, determine their high potential to enhance phytoremediation and revegetation projects for HM-contaminated, saline, and desertic lands reclamation
Star Polymers as Non-Viral Carriers for Apoptosis Induction
Get PDFApoptosis is a widely controlled, programmed cell death, defects in which are the source of
various diseases such as neurodegenerative diseases as well as cancer. The use of apoptosis in the
therapy of various human diseases is of increasing interest, and the analysis of the factors involved in
its regulation is valuable in designing specific carriers capable of targeting cell death. Highly efficient
and precisely controlled delivery of genetic material by low-toxic carriers is one of the most important
challenges of apoptosis-based gene therapy. In this work, we investigate the effect of the star polymer
with 28 poly(N,N0-dimethylaminoethyl methacrylate) arms (STAR) on human cells, according to its
concentration and structure. We show that star polymer cytotoxicity increases within its concentration
and time of cells treatment. Except for cytotoxic effect, we observe morphological changes such as a
shrinkage, loss of shape and begin to detach. We also prove DNA condensation after star polymer
treatment, one of the most characteristic feature of apoptosis. The results indicate that the use of STAR
triggers apoptosis in cancer cells compared to various normal cells, what makes these nanoparticles
a promising drug in therapeutic strategy, which targets apoptosis. We demonstrate highlighting
potential of star polymers as an innovative tool for anti-cancer therapy
Polyhumous Dystrophic Pit Lakes: Hydrographic and Hydrochemical Characteristics on the Example of Reservoirs in the Włoszczowska Basin, Central Poland
Get PDFThe article presents the hydrographic and hydrochemical characteristics of post-exploitation
reservoirs formed in peat excavations. Two natural bog lakes were selected as the control objects for
the study. The research indicated that both the waters of post-exploitation peat reservoirs and natural
bog lakes show low electrolytic conductivity (<100 S/cm) and acidic water reaction (pH < 5.5).
The concentration of major cations and anions is also very low. The concentration of calcium and
magnesium does not exceed a few mg/L. Hydrochemically, all post-exploitation peat reservoirs are
bi-ionic sulphate–calcium (SO4
2-Ca2+). This distinguishes post-exploitation peat reservoirs from
natural bog lakes in which multi-ion waters were found, for example, sulphate–chloride–calcium
(SO4
2-Cl-Ca2+) and sulphate–calcium–sodium (SO4
2-Ca2+-Na+). The calculated water humic
state index (HSI) allowed the classifying of the examined reservoirs as polyhumous. The value of this
index, in all reservoirs, was >50. Based on the calculated hydrochemical dystrophy index (HDI), it
was found that all post-exploitation peat reservoirs are dystrophic. So far, no such hydrochemical
type has been found in other post-exploitation peat reservoirs. Therefore, the examined objects
should be classified as unique post-exploitation peat reservoirs
Parallel corpus and equivalencing
No full textThe article is devoted to possibilities of using the InterCorp Polish-Russian paralel corpus in the process of searching for translations equivalents. It also presents resources and functionalities of the InterCorp, and concentrates on how it can be used by Russian philologists. It is increasingly useful in linguistic and translatological research. A particular focus is put on the process of equivalencing i.e. searching for and establishing equivalents and a significant role of the parallel corpus which allows for finding appropriate translation solutions that sometimes can pose a problem for a single translator or lexicographer. The article also presents a deeper reflection on the significance and prospects of empirical research in the contemporary linguistics
Which Suture to Choose in Hepato-Pancreatic-Biliary Surgery? Assessment of the Influence of Pancreatic Juice and Bile on the Resistance of Suturing Materials—In Vitro Research
No full text(1) Background: The choice of appropriate surgical suture during operation is of great
significance. Currently, there are no objective studies regarding the resistance of commonly used
sutures in biliary tract surgery. (2) Methods: This fact leads one to conduct research concerning the
resistance of the sutures (Polydioxanone, Poliglecaprone, Poliglactin 910, and their analogues coated
with antibacterial triclosan) in the environment of sterile and contaminated bile and pancreatic juice.
Tensile strength was tested at days 0, 7, 14, 21, and 28 of research. The study was performed in in vitro
conditions for 28 days. (3) Results: Pancreatic juice and bile has a significant influence on the tensile
strength of each suture. (4) Conclusions: The study indicated that sutures made of polydioxanone
had the best qualities during the entire experiment
Effect of graphene material structure and iron oxides deposition method on morphology and properties of graphene/iron oxide hybrids
Get PDFIn this work, various facile approaches were applied to prepare hybrids of graphene nanoplatelets (GNPs) and
graphene oxide (GO) with iron oxides (IO) nanoparticles (NPs). The IO NPs were synthesized and deposited on
the graphene surfaces via: (1) co-precipitation using Fe (II) and Fe (III) salts, (2) homogeneous precipitation of
Fe2O3 from FeCl3 solution, (3) the attaching of Fe2O3 NPs functionalized with 3-aminopropyltrimethoxysilane to
graphene surfaces of GO and GNPs. The effects of the graphene material and preparation procedure on the
structural characteristics of the hybrids were studied. Their morphology was studied by scanning electron microscopy
and transmission microscopy. Lattice parameters and crystallite sizes of the synthesized hybrid materials
were assessed by X-ray diffraction. Raman spectroscopy was used to determine the change of order degree of
graphene structures as a results of IO NPs deposition and interactions IO NPs with graphene sheets. Binding
energy for IO NPs and graphene structures were determined by photoelectron X-ray spectroscopy. Thermogravimetric
analysis was applied to find differences in the thermal stability of hybrids. The hybrids are proposed as
nanofillers to polymer composites, however they have large potential applications as supercapacitors, advanced
anode materials for lithium-ion batteries, magnetically targeted drug delivery, and magnetic resonance imaging
Konceptualizacja GNIEWU na przykładzie ŻÓŁCI w języku czeskim i polskim
No full textAnaliza wykazała, że z punktu widzenia lingwistyki nazwa żółć czes. żluć jest jednym z podstawowych wykładników do określania uczuć, koncentrując się zwłaszcza na konceptualizowanym ‘gniewie’, ale i na ‘złości’, ‘irytacji’, ‘wściekłości’, ‘rozdrażnieniu’, ‘oburzeniu’, ‘zdenerwowaniu’, ‘szale’ i ‘furii’. Przedstawiono koncepcję kognitywną, że uczucie gniewu rozumiane jest jako pewien proces, który zaczyna się w jakimś określonym momencie, następnie rozwija się i później kończy. Na ten proces ma wpływ temperatura i ciśnienie. Po wybuchu człowiek już uczuć nie kontroluje. Wszystkie te etapy przytoczono przy użyciu odpowiednich czasowników w tekście. Udowodniono trzy ważne stwierdzenia, że ciało (experiencerii) jest pojemnikiem dla fizjologicznych efektów gniewu; że konceptualizacja uczuć jest związana z ucieleśnieniem myśli oraz że myślimy i mówimy metaforami, które są ujęzykowionymi pojęciami. Przeprowadzona analiza pokazała, że czeski zasób szeroko pojmowanych związków frazeologicznych z komponentem leksykalnym żółć czes. żluć wskazuje liczne podobieństwa i zbieżności z językiem polskim (ze względu na typologicznie i genetycznie bliskie pokrewieństwa językowe), chociaż zdarzają się od tej reguły nieliczne odstępstwa
Humour against All Odds! Humour Research Avenues
No full textHumour permeates human life. It accompanies us when we feel good and bad because of its
provable medical and psychological effects and its ability to influence our relationships
with other people. As an omnipresent phenomenon, humour unites cultures and generations,
coming in many different forms. Humour frequently stems from a mixture of
verbal, non-verbal, extralinguistic, and intercultural factors. It is also one of the most
original result-oriented communication forms as it principally aims at interacting with its
recipient in order to elicit a specific reaction. The aim of the article is therefore to investigate
the nature of humour, its types, functions, and characteristics, and its research
possibilities
Fungal genetic biodiversity and metabolic activity as an indicator of potential biological weathering and soil formation – Case study of towards a better understanding of Earth system dynamics
No full textTerrestrial plants act as ecosystem engineers modifying the flow of energy and matter and creating new habitats
for other organisms. This vital concept also encompasses plants’ effects on landforms and soils, crucial components
of forested landscapes worldwide. In the present study, we investigate how trees through their roots and
symbiotic organisms influence soil-weathering processes. The aim of the study was to answer one of the big
questions in Earth sciences: how do biological agents, including fungi, acting at the critical interface between the
biosphere and the abiotic environment, shape soil and landscape evolution? Within the present study we ask
what is the level of fungal activity within root systems of trees and how can it influence biological weathering.
The area of interest is in the Poprad River gorge in the southern part of the Sącz Beskidy Mountains, the Outer
Western Carpathians. We applied the following analyses: 1) determination of the structural diversity of fungi
(ITS1) and 2) assessment of the metabolic profile of soils (Biolog FFPlates). The highest average number of
classified genera were fungi which simultaneously carried out pathotrophic, saprotrophic and symbiotrophic
functions. Boletales, Agaricales, Cantharellales and Archaeorhizomycetales were the most abundant orders, but
in one sample we also found a particularly high proportion of the order Mortierellales. The order Boletales and its
family Boletaceae were significantly enriched in rock crack samples, whereas the highest number of differentially
abundant taxa was observed in reference samples. The most frequently utilised substrates by fungi were: glycyl-Lglutamic
acids, L-ornithine, L-phenylalanine, L-proline, D-galacturonic acid, fumaric acids, D-saccharic acids,
succinic acids and N-acetyl-D-glucosamine. Our study demonstrates that the fungal community in the root zone is
geochemically active and the organic acids secreted by plant roots in oligotrophic conditions and nutrient
limitations significantly affect soil weathering