We performed a comparative study of self-assembling properties of liponucleoside materials containing different nucleobases in their hydrophilic headgroups, but possessing the same type of lipophilic moiety in their hydrophobic tails. Surface pressure versus area isotherms (π(A)) of monolayers formed at the air-water interface show that guanine-based materials form stable monolayer films exhibiting a profound first order phase transition from the liquid expanded to the condensed phase. Materials based on other nucleobases form less stable films exhibiting a liquid-like behaviour. Analysis of surface structures of Langmuir films with Brewster angle microscopy (BAM) and of Langmuir-Blodgett (LB) films deposited on mica surface by atomic force microscopy (AFM) confirms surface organization as resolved from the isotherms. The specific behaviour of molecules with a guanine head group is attributed to their optimal hydrophilic/hydrophobic balance, which is associated with the low water solubility of guanine derivatives.
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http://dx.doi.org/10.1016/j.colsurfb.2012.10.019 | DOI Listing |
Turk J Pediatr
December 2024
Department of Pediatric Rheumatology, Umraniye Training and Research Hospital, University of Health Sciences, İstanbul, Türkiye.
Background: Polyarteritis nodosa (PAN) is a rare and serious form of systemic necrotizing vasculitis that predominantly affects medium and small-sized arteries, with central nervous system involvement being particularly uncommon. Treatment strategies are tailored according to the extent and severity of the disease. While conventional therapy includes glucocorticoids and conventional disease-modifying-rheumatic drugs (cDMARDs), biologic agents may be critical for severe and refractory cases.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Chemical & Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, United States.
Simultaneously hydrophilic and oleophobic surfaces offer substantial advantages for applications such as antifogging, self-cleaning, and oil-water separation. It remains challenging to engineer such surfaces without requiring polar functional groups. This study introduces HFIL, a novel ionic liquid (IL) coating that achieves simultaneous hydrophilic and oleophobic properties via a one-step dip-coating process without relying on polar functional groups.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology" of the Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia. Electronic address:
UV-irradiation is a stress factor for proteins, leading to disruption of their native structure. Test systems based on UV-irradiated proteins are relevant for researchers, as they allow working directly with damaged protein molecules, which can be important when studying the properties and mechanisms of action of various antiaggregation agents. The study of UV-irradiated proteins can also have applied significance, including medical.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Laboratory for Protein Crystallography, Institute for Protein Research, Osaka University, Suita, Osaka 565-0871, Japan.
[FeFe]-hydrogenases catalyze the reversible two-electron reduction of two protons to molecular hydrogen. Although these enzymes are among the most efficient H-converting biocatalysts in nature, their catalytic cofactor (termed H-cluster) is irreversibly destroyed upon contact with dioxygen. The [FeFe]-hydrogenase CbA5H from has a unique mechanism to protect the H-cluster from oxygen-induced degradation.
View Article and Find Full Text PDFPLoS Genet
January 2025
Department of Psychology, University of Texas at Austin, Austin, Texas, United States of America.
Social hierarchies are a common form of social organization across species. Although hierarchies are largely stable across time, animals may socially ascend or descend within hierarchies depending on environmental and social challenges. Here, we develop a novel paradigm to study social ascent and descent within male CD-1 mouse social hierarchies.
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