The flora of the selected cemeteries in the Świętokrzyski region – floristic and ecological subject matters

The study focuses mainly on the flora and concerns the natural resources of species/genetic vascular plants occurring in the three selected Catholic cemeteries in mezoregion of Świetokrzyskie Mountains namely in Starachowice, Chybice and Bieliny. 476 species including lower taxa were identified in total within the sites. The number of synanthropic taxa in the flora, which colonize the different life substrates in the examined graveyards was determined. The attention was also paid to the participation of expansive native species – apophites and invasive (of a foreign origin) species – anthropophites. The synanthropic species found in the studied cemeteries are mainly ruderal plants of Class: Artemisietea vulgaris, Molino-Arrhenatheretea and row Plantaginetalia Majoris, Agropyretea intermedio-repentis and Chenepodietea. Also a small group of species under the strict and partial low protection in Poland, which grow on the habitats (an ex situ) was determined

The role of hydrophobic interactions in ankyrin–spectrin complex formation

AbstractSpectrin and ankyrin are the key components of the erythrocyte cytoskeleton. The recently published crystal structure of the spectrin–ankyrin complex has indicated that their binding involves complementary charge interactions as well as hydrophobic interactions. However, only the former is supported by biochemical evidence. We now show that nonpolar interactions are important for high affinity complex formation, excluding the possibility that the binding is exclusively mediated by association of distinctly charged surfaces. Along these lines we report that substitution of a single hydrophobic residue, F917S in ankyrin, disrupts the structure of the binding site and leads to complete loss of spectrin affinity. Finally, we present data showing that minimal ankyrin binding site in spectrin is formed by helix 14C together with the loop between helices 15 B/C

Rocznik Lubuski (t.31, cz.2): Pogranicze Lubusko-Brandenburskie po II wojnie światowej

Pogranicze Lubusko-Brandenburskie po II wojnie światowejPod redakcją:<br> Czesława Osękowskiego<br>i RobertaSkobelskieg

Ultrasound cavitation and exfoliation dynamics of 2D materials re-vealed in operando by X-ray free electron laser megahertz imaging

Ultrasonic liquid phase exfoliation is a promising method for the production of two-dimensional (2D) layered materials. A large number of studies have been made in investigating the underlying ultrasound exfoliation mechanisms. However, due to the experimental challenges for capturing the highly transient and dynamic phenomena in real-time at sub-microsecond time and micrometer length scales simultaneously, most theories reported to date still remain elusive. Here, using the ultra-short X-ray Free Electron Laser pulses (~25ps) with a unique pulse train structure, we applied MHz X-ray Microscopy and machine-learning technique to reveal unambiguously the full cycles of the ultrasound cavitation and graphite layer exfoliation dynamics with sub-microsecond and micrometer resolution. Cyclic fatigue shock wave impacts produced by ultrasound cloud implosion were identified as the dominant mechanism to deflect and exfoliate graphite layers mechanically. For the graphite flakes, exfoliation rate as high as ~5 angstroms per shock wave impact was observed. For the HOPG graphite, the highest exfoliation rate was ~0.15 angstroms per impact. These new findings are scientifically and technologically important for developing industrial upscaling strategies for ultrasonic exfoliation of 2D materials

Key Amino Acid Residues of Ankyrin-Sensitive Phosphatidylethanolamine/Phosphatidylcholine-Lipid Binding Site of βI-Spectrin

It was shown previously that an ankyrin-sensitive, phosphatidylethanolamine/phosphatidylcholine (PE/PC) binding site maps to the N-terminal part of the ankyrin-binding domain of β-spectrin (ankBDn). Here we have identified the amino acid residues within this domain which are responsible for recognizing monolayers and bilayers composed of PE/PC mixtures. In vitro binding studies revealed that a quadruple mutant with substituted hydrophobic residues W1771, L1775, M1778 and W1779 not only failed to effectively bind PE/PC, but its residual PE/PC-binding activity was insensitive to inhibition with ankyrin. Structure prediction and analysis, supported by in vitro experiments, suggests that “opening” of the coiled-coil structure underlies the mechanism of this interaction. Experiments on red blood cells and HeLa cells supported the conclusions derived from the model and in vitro lipid-protein interaction results, and showed the potential physiological role of this binding. We postulate that direct interactions between spectrin ankBDn and PE-rich domains play an important role in stabilizing the structure of the spectrin-based membrane skeleton