Repozytorium Uniwersytetu Śląskiego RE-BUŚ
Not a member yet
23505 research outputs found
Sort by
Scholarly Potential of the Lviv Interwar Romanist Community
Full text linkThis article presents the scholarly activity of two generations of researchers focusing on Roman law, associated professionally with the Lviv university in the interwar period. First, it shows the attainments of Leon Piniński and Marceli Chlamtacz. Then, it focuses on the attainments of a younger generation of Lviv scholars, including Wacław Osuchowski and Edward Gintowt. The presentation of the activities of these scholars made it possible to demonstrate the scholarly potential of the Lviv interwar Romanist community, which was one of the leading centers of research on Roman law in interwar Poland, if not the most important one
Continental-scale monthly thermal anomalies in Europe during the years 1951-2018 and their occurrence in relation to atmospheric circulation
Full text linkThis study determines the frequency, location and spatial extent of such large-area monthly thermal anomalies, which are referred to in this paper as continental-scale thermal anomalies (CTAs). The research was based on monthly mean air temperature values from 210 weather stations over the 68-year period 1951-2018. A CTA is defined as an anomaly when the monthly mean temperature exceeded the long-term average by at least 2 standard deviations at a minimum of 40 stations. This study attempts to explain the occurrence of such CTAs (negative CTAs- and positive CTAs+) in relation to the circulation conditions over Europe. In the years 1951-2018, there were 16 CTAs- (mainly in winter and autumn) and 25 CTAs+ (predominantly in summer). One manifestation of climate warming is the ever less frequent occurrence of CTAs- and a growing frequency and spatial extent of CTAs+. The immediate cause behind CTAs was the occurrence of characteristic synoptic situations, leading to intensified advection of cold or hot air masses, often driven by radiation factors. The formation of CTAs- was much more often associated with very extensive and long-lasting anticyclonic systems, and that the associated synoptic situations over Europe lasted much longer than in the case of CTAs+
Vapor-Deposited Thin Films: Studying Crystallization and α-relaxation Dynamics of the Molecular Drug Celecoxib
No full textCrystallization is one of the major challenges in using glassy solids for
technological applications. Considering pharmaceutical drugs, maintaining a stable
amorphous form is highly desirable for improved solubility. Glasses prepared by the
physical vapor deposition technique got attention because they possess very high stability,
taking thousands of years for an ordinary glass to achieve. In this work, we have
investigated the effect of reducing film thickness on the α-relaxation dynamics and
crystallization tendency of vapor-deposited films of celecoxib (CXB), a pharmaceutical
substance. We have scrutinized its crystallization behavior above and below the glasstransition
temperature (Tg). Even though vapor deposition of CXB cannot inhibit
crystallization completely, we found a significant decrease in the crystallization rate with decreasing film thickness. Finally, we have
observed striking differences in relaxation dynamics of vapor-deposited thin films above the Tg compared to spin-coated counterparts
of the same thickness
Changes in Species and Functional Diversity of the Herb Layer of Riparian Forest despite Six Decades of Strict Protection
No full textThe herb layer of temperate forests contributes to long-term forest ecosystem functioning
and provisioning of ecosystem services. Therefore, a thorough understanding of its dynamics in the
face of environmental changes is essential. This paper focuses on the species and functional diversity
of the herb layer of riparian forests to verify how these two community components changed over
time and under strict protection. The understory vegetation was surveyed on 42 semi-permanent
plots in three time periods between 1960 and 2020. The overall pattern in vegetation changes that
related to species richness and diversity, functional structure, and habitat conditions was analyzed
using ordination and permutation techniques. We found significant changes in species composition
and the functional structure of herbaceous vegetation over the last six decades. Forests were
enriched with nutrient-demanding and alien species. A significant increase in functional diversity
and the proportion of species with high SLA and canopy height was also observed, whereas changes
in habitat conditions were insignificant. The observed trends indicate that the strict protection of
forest communities within small and isolated reserves does not fully protect their species composition.
Forest reserves should be surrounded by unmanaged forests and spatially connected to allow
species mobility
Dielectric and electric properties of Ba0.996La0.004Ti0.999O3 ceramics doped with europium and hafnium ions
Full text linkLanthanum-modified BaTiO3 electroceramic materials have superior dielectric and piezoelectric
properties. Ba0.996La0.004Ti0.999O3 (BLT4) seems to be a serious candidate for ultracondensator
applications. This manuscript describes the results of hafnium and europium modification of BLT 4
ceramics. The pure and doped ceramic materials were synthesized by the conventional mixed oxide
method. The microstructure of obtained samples was examined by scanning electron microscope. The
investigations reveal strong correlations between the presence of admixture and the grain size, which
was especially visible in the case of the hafnium dopant. The frequency and temperature dielectric
characteristics measurements revealed a decrease in electric permittivity. Moreover, the impedance
spectroscopy investigations showed severe changes in grains and grain-boundary resistivity, which
was connected with changes in electric conductivity
Sugar decorated star-shaped (co)polymerswith resveratrol-based core – physicochemicaland biological properties
Full text linkStar-shaped glycopolymers due to the attractive combination of the physicochemical, morphological, self-assembly properties along with biological activity have gained increased attention as innovative agents in novel cancer therapies. Unfortunately, the production of these highly desirable biomaterials remains a challenge in modern macromolecular chemistry. The main reason for that is the low polymerizability of ionic glycomonomers originated from their steric congestion and the occurrence of ionic interactions that generally negatively influence the polymerization progress and hinder controllable reaction pathway. In this work, the new ionic sugar monomer was (co)polymerized for the first time via Activator Generated by Electron Transfer Atom Transfer Radical Polymerization (AGET ATRP) using a three-arm resveratrol-based core to obtain star-like (co)polymers. The obtained products were examined in terms of their physicochemical properties and morphology. Aside from the synthesis of these new glycopolymers, also a thorough description of their thermal properties, ability to self-assembly, the formation of stable superstructures was studied in detail. It was found that examined (co)polymers did not show any heterogeneities and phase separation, while their variation of glass transition temperature (Tg) was strictly related to the change in the number of glycomonomer. Also, the stability and shapes of formed superstructures strictly depend on their composition and topology. Finally, we have shown that synthesized carbohydrate-based polymers revealed high antiproliferative activity against several cancer cell lines (i.e., breast, colon, glioma, and lung cancer). The cytotoxic activity was particularly observed for star-shaped polymers that were systematically enhanced with the growing concentration of amine moieties and molecular weight. The results presented herein suggest that synthesized star-shaped glyco(co)polymers are promising as drug or gene carriers in anticancer therapies or anti-tumor agents, depending on their cytotoxicity.
Graphical abstrac
Electrical conductivity and dielectric relaxation in Ag1-xLixNbO3
Full text linkThe broadband electrical properties of Ag1xLixNbO3 (ALNx) ceramics (x 0.1) together
with AgNbO3 (AN) crystals were studied over a wide temperature interval of 20–800 K. For ALNx
with x 0.05, a very diffused ferroelectric phase transition was observed. The position of the dielectric
permittivity maximum in this phase transition is strongly frequency-dependent and is described
well by the Vogel–Fulcher law. The freezing temperature decreases when the lithium concentration
increases. Below the ferroelectric phase transition temperature, the dielectric dispersion is mainly
caused by ferroelectric domain dynamics. Moreover, for ALN3 and ALN5 ceramics at very low
temperatures (below 100 K), behavior typical of dipolar glasses is observed. At higher temperatures
(above 650 K for ALN5), electrical conductivity effects become important. The DC conductivity
increases with temperature according to the Arhenius law and the activation energy is highest in
the antiferroelectric phase. Moreover, the activation energy is strongly dependent on the lithium
concentration and it is greatest when x = 0.02
Wprowadzenie
Full text link"Publikacja, którą oddajemy w Państwa ręce, jest ekwiwalentem VII Ogólnopolskiego
Sympozjum Naukowego Neurodydaktyki. Zdajemy sobie sprawę, że nie zastąpi
tego, czym jest dla uczestników bezpośrednie spotkanie. Z naszych zeszłorocznych doświadczeń
wynika, że nie jest tego w stanie dać także namiastka w postaci formy zdalnej.
Dlatego w tym roku zdecydowaliśmy się na taką formę intelektualnego spotkania.
Od początku istnienia Sympozjum naszą intencją było zbliżenie do siebie praktyków
edukacji oraz przedstawicieli tych dziedzin nauki, którzy proces ten widzą jako podmiot
swoich refl eksji i badań. Nie chodziło jedynie o wymianę doświadczeń i wiedzy, lecz
także o tworzenie przestrzeni wspólnego działania i wzajemnych inspiracji. Pretekstem,
który miał do tego zbliżenia posłużyć, była silnie wkraczająca w obszar dydaktyki neurobiologia
z jej fascynującymi odkryciami. Szybko okazało się, że sama wiedza o ludzkim
mózgu nie przynosi rozwiązań konkretnych problemów, z jakimi zderza się edukacja, jeśli
nie zostanie włączona w szerszy kontekst. Neurodydaktyka jest użytecznym i cennym narzędziem
interpretacji, nie jest jednak zbiorem gotowych rozwiązań. Wyjaśnia, dlaczego
pewne zjawiska są takie, a nie inne, wskazuje granice naszych możliwości i odpowiedzialności,
ale nie jest sposobem na usprawiedliwienie wyborów, jakich dokonujemy. Te pozostają
poza granicami naukowej jednoznaczności." (fragm.
Characteristics of natural background radiation in the GIG Experimental Mine ‘Barbara’, Poland
Full text linkUnderground locations can be used in various ways for scientific and economic purposes. One of the main factors influencing the safety level in the underground mine workings is natural radioactivity. The article presents research carried out on the natural radioactivity in shallow mine workings at the GIG Experimental Mine ‘Barbara’. The description of the natural radiation includes radon determination in the air, in situ gamma spectrometry, neutron flux measurements, and laboratory measurements of 226,228Ra, 40K, and 234,238U isotopes using gamma and alpha spectrometry techniques. In the measurement chamber at the depth 46 m (122 m w.e.) in the sandstone layer, the photon flux registered at the 7–3150 keV energy range is equal to 17.6 ± 1.9 cm−2s−1, the gamma-ray dose rate is 0.200 ± 0.029 µSv/h, and the thermal neutron flux is equal to (8.6 ± 1.1) × 10−6 cm−2s−1. After closing the measurement chamber and turning off ventilation, a significant ingrowth of 222Rn content was observed, reaching the value of 4040 ± 150 Bq/m3. An increased gamma-ray flux and thermal neutron flux were observed in the investigated location
miR172 Regulates WUS during Somatic Embryogenesis in Arabidopsis via AP2
No full textIn plants, the embryogenic transition of somatic cells requires the reprogramming of the
cell transcriptome, which is under the control of genetic and epigenetic factors. Correspondingly,
the extensive modulation of genes encoding transcription factors and miRNAs has been indicated
as controlling the induction of somatic embryogenesis in Arabidopsis and other plants. Among
the MIRNAs that have a differential expression during somatic embryogenesis, members of the
MIRNA172 gene family have been identified, which implies a role of miR172 in controlling the
embryogenic transition in Arabidopsis. In the present study, we found a disturbed expression of
both MIRNA172 and candidate miR172-target genes, including AP2, TOE1, TOE2, TOE3, SMZ and
SNZ, that negatively affected the embryogenic response of transgenic explants. Next, we examined
the role of AP2 in the miR172-mediated mechanism that controls the embryogenic response. We
found some evidence that by controlling AP2, miR172 might repress the WUS that has an important
function in embryogenic induction. We showed that the mechanism of the miR172-AP2-controlled
repression of WUS involves histone acetylation. We observed the upregulation of the WUS transcripts
in an embryogenic culture that was overexpressing AP2 and treated with trichostatin A (TSA),
which is an inhibitor of HDAC histone deacetylases. The increased expression of the WUS gene
in the embryogenic culture of the hdac mutants further confirmed the role of histone acetylation in
WUS control during somatic embryogenesis. A chromatin-immunoprecipitation analysis provided
evidence about the contribution of HDA6/19-mediated histone deacetylation to AP2-controlled WUS
repression during embryogenic induction. The upstream regulatory elements of the miR172-AP2-
WUS pathway might involve the miR156-controlled SPL9/SPL10, which control the level of mature
miR172 in an embryogenic culture