Interaction of cylindrical polymer brushes in dilute and semi-dilute solution

We present a systematic study of flexible cylindrical brush-shaped macromolecules in a good solvent by small-angle neutron scattering (SANS), static light scattering (SLS), and by dynamic light scattering (DLS) in dilute and semi-dilute solution. The SLS and SANS data extrapolated to infinite dilution lead to the shape of the polymer that can be modeled in terms of a worm-like chain with a contour length of 380 nm and a persistence length of 17.5 nm. SANS data taken at higher polymer concentration were evaluated by using the polymer reference interaction site model (PRISM). We find that the persistence length reduce from 17.5 nm at infinite dilution to 5.3 nm at the highest concentration (volume fraction 0.038). This is comparable with the decrease of the persistence length in semi-dilute concentration predicted theoretically for polyelectrolytes. This finding reveals a softening of stiffness of the polymer brushes caused by their mutual interaction

Epigenetic mechanisms in virus-induced tumorigenesis

About 15–20% of human cancers worldwide have viral etiology. Emerging data clearly indicate that several human DNA and RNA viruses, such as human papillomavirus, Epstein–Barr virus, Kaposi’s sarcoma-associated herpesvirus, hepatitis B virus, hepatitis C virus, and human T-cell lymphotropic virus, contribute to cancer development. Human tumor-associated viruses have evolved multiple molecular mechanisms to disrupt specific cellular pathways to facilitate aberrant replication. Although oncogenic viruses belong to different families, their strategies in human cancer development show many similarities and involve viral-encoded oncoproteins targeting the key cellular proteins that regulate cell growth. Recent studies show that virus and host interactions also occur at the epigenetic level. In this review, we summarize the published information related to the interactions between viral proteins and epigenetic machinery which lead to alterations in the epigenetic landscape of the cell contributing to carcinogenesis

Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.

Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field

Charakterystyka wybranych właściwości fizyko-mechanicznych oraz składu chemicznego kruszyw wyprodukowanych na bazie: żużli stalowniczych, porfiru i diabazu

This paper presents the results of tests of selected physical and mechanical properties as well as the chemical composition of two types of natural aggregates: porphyry and diabase, as well as artificial aggregate based on steel slags. Based on the conducted tests, it was established that the physical and mechanical properties of the artificial aggregate exhibit slightly lower parameters as compared to the results obtained for porphyry and diabase aggregates. However, this does not limit the possibility of using the aggregate based on steel slags, as according to the applicable WT-4 and WT-5 standards, it can be used in mixtures unbound to the improved subsoil and layers of the road foundation as well as road mixtures with hydraulic binders for each category of traffic load. The chemical composition of the aggregate based on steel slags differs from the chemical composition of the tested natural aggregates. The slags contain lower amounts of SiO2 and Al2O3, while the concentration of CaO and Fe2O3 is greater. Additionally, heavy metals have also been exhibited in the slags. However, it was established that the alkaline nature of the slags, which is affected by low sulphur content and a significant proportion of CaO, as well as the way the metals occur limit the possibility of heavy metals release and migration from slags. The tested steel slags may constitute a prospective material used in road construction.W artykule przedstawiono wyniki badań wybranych właściwości fizyko-mechanicznych oraz składu chemicznego dwóch rodzajów kruszywa naturalnego: porfirowego i diabazowego oraz kruszywa sztucznego wyprodukowanego na bazie żużli stalowniczych. Na podstawie przeprowadzonych badań stwierdzono, że właściwości fizyko-mechaniczne (gęstość objętościowa, nasiąkliwość, mrozoodporność, odporność na rozdrabnianie LA, wytrzymałość na miażdżenie) kruszywa sztucznego wykazują nieco niższe parametry w odniesieniu do wyników oznaczeń uzyskanych dla kruszywa porfirowego i diabazowego. Nie ogranicza to jednak możliwości wykorzystania kruszywa na bazie żużli stalowniczych, gdyż wg obowiązujących standardów WT-4 i WT-5, może być ono stosowane w mieszankach niezwiązanych do ulepszonego podłoża i warstw podbudowy drogowej oraz drogowych mieszankach związanych spoiwami hydraulicznymi dla każdej kategorii obciążenia ruchem. Skład chemiczny kruszywa na bazie żużli stalowniczych różni się od składu chemicznego badanych kruszyw naturalnych. Żużle zawierają mniejsze ilości SiO2 oraz Al2O3, wzrasta w nich natomiast koncentracja CaO oraz Fe2O3, w żużlach oznaczono także obecność metali ciężkich. Stwierdzono jednak, że zasadowy charakter żużli, na który wpływa niska zawartość siarki oraz znaczny udział CaO, jak również sposób występowania metali przede wszystkim w formie rozproszonej w szkliwie oraz jako podstawienia w strukturze wewnętrznej faz krzemianowych i tlenkowych ograniczają możliwości uwalniania i migracji metali ciężkich z żużli. Badane żużle stalownicze mogą stanowić perspektywiczny materiał znajdujący zastosowanie w budownictwie drogowym