A highly processive topoisomerase I: studies at the single-molecule level.

International audienceAmongst enzymes which relieve torsional strain and maintain chromosome supercoiling, type IA topoisomerases share a strand-passage mechanism that involves transient nicking and re-joining of a single deoxyribonucleic acid (DNA) strand. In contrast to many bacterial species that possess two type IA topoisomerases (TopA and TopB), Actinobacteria possess only TopA, and unlike its homologues this topoisomerase has a unique C-terminal domain that lacks the Zn-finger motifs characteristic of type IA enzymes. To better understand how this unique C-terminal domain affects the enzyme's activity, we have examined DNA relaxation by actinobacterial TopA from Streptomyces coelicolor (ScTopA) using real-time single-molecule experiments. These studies reveal extremely high processivity of ScTopA not described previously for any other topoisomerase of type I. Moreover, we also demonstrate that enzyme processivity varies in a torque-dependent manner. Based on the analysis of the C-terminally truncated ScTopA mutants, we propose that high processivity of the enzyme is associated with the presence of a stretch of positively charged amino acids in its C-terminal region

Characterization of Al₂O₃ Matrix Composites Fabricated via the Slip Casting Method Using NiAl-Al₂O₃ Composite Powder

This work aimed to characterize Al2O3 matrix composites fabricated by the slip casting method using NiAl-Al2O3 composite powder as the initial powder. The composite powder, consisting of NiAl + 30 wt.% Al2O3, was obtained by mechanical alloying of Al2O3, Al, and Ni powders. The composite powder was added to the Al2O3 powder to prepare the final powder for the slip casting method. The stained composite samples presented high density. EDX and XRD analyses showed that the sintering process of the samples in an air atmosphere caused the formation of the NiAl2O4 spinel phase. Finally, the phase composition of the composites changed from the initial phases of Al2O3 and NiAl to Al2O3, Ni, and NiAl2O4. However, in the area of Ni, fine Al2O3 particles remaining from the initial composite powder were visible. It can be concluded that after slip casting, after starting with Al2O3 and the composite powder (NiAl-Al2O3) and upon sintering in air, ceramic matrix composites with Ni and NiAl2O4 phases, complex structures, high-quality sintered samples, and favorable mechanical properties were obtained

Telemedicine solutions in cardiology: a joint expert opinion by the Information Technology and Telemedicine Committee of the Polish Cardiac Society, the Section of Noninvasive Electrocardiology and Telemedicine of the Polish Cardiac Society, and the Clinical Research Committee of the Polish Academy of Sciences (short version, 2021)

ABSTRACT Telemedicine involves diagnostic, therapeutic and educational services being offered remotely by healthcare professionals to exchange crucial clinical information. It is a rapidly developing form of medical activity and part of medical industry, with advanced technologies already available in Poland. Cardiology is one of the fields in which telemedicine methods were pioneered and introduced into everyday practice. Some of these methods have already become standard procedures for diagnosis and treatment in some Polish centers, with other soon to follow. Clinical study results not only demonstrate reliability and usefulness of telemedicine technologies but also show that their use in clinical practice improves the patients’ prognoses and quality of life. Moreover, study results in highly developed countries show a potential cost-effectiveness of telemedicine from the perspective of healthcare systems. There is an unquestionable need to establish clear rules for telemedicine use in Poland, which would ensure their high quality and adequate clinical application. This paper is a summary of the current status of telemedicine solutions used in cardiology, with a particular focus on the Polish healthcare system, and presents both the commonly available solutions and those that are expected to develop rapidly in the near future