52 research outputs found
Comparing the Folding and Misfolding Energy Landscapes of Phosphoglycerate Kinase
AbstractPartitioning of polypeptides between protein folding and amyloid formation is of outstanding pathophysiological importance. Using yeast phosphoglycerate kinase as model, here we identify the features of the energy landscape that decide the fate of the protein: folding or amyloidogenesis. Structure formation was initiated from the acid-unfolded state, and monitored by fluorescence from 10 ms to 20 days. Solvent conditions were gradually shifted between folding and amyloidogenesis, and the properties of the energy landscape governing structure formation were reconstructed. A gradual transition of the energy landscape between folding and amyloid formation was observed. In the early steps of both folding and misfolding, the protein searches through a hierarchically structured energy landscape to form a molten globule in a few seconds. Depending on the conditions, this intermediate either folds to the native state in a few minutes, or forms amyloid fibers in several days. As conditions are changed from folding to misfolding, the barrier separating the molten globule and native states increases, although the barrier to the amyloid does not change. In the meantime, the native state also becomes more unstable and the amyloid more stable. We conclude that the lower region of the energy landscape determines the final protein structure
A simple electronic ladder model harboring parafermions
Parafermions are anyons with the potential for realizing non-local qubits
that are resilient to local perturbations. Compared to Majorana zero modes,
braiding of parafermions implements an extended set of topologically protected
quantum gates. This, however, comes at the price that parafermionic zero modes
can not be realized in the absence of strong interactions whose theoretical
description is challenging. In the present work, we construct a simple lattice
model for interacting spinful electrons with parafermionic zero energy modes.
The explicit microscopic nature of the considered model highlights new
realization avenues for these exotic excitations in recently fabricated quantum
dot arrays. By density matrix renormalization group calculations, we identify a
broad range of parameters, with well-localized zero modes, whose parafermionic
nature is substantiated by their unique periodic Josephson spectrum
Mapping the nanomechanical properties of graphene suspended on silica nanoparticles
Using nanoparticles to impart extrinsic rippling in graphene is a relatively
new method to induce strain and to tailor the properties of graphene. Here we
study the structure and elastic properties of graphene grown by chemical vapour
deposition and transferred onto a continuous layer of SiO2 nanoparticles with
diameters of around 25 nm, prepared by Langmuir-Blodgett technique on Si
substrate. We show that the transferred graphene follows only roughly the
morphology induced by nanoparticles. The graphene membrane parts bridging the
nanoparticles are suspended and their adhesion to the AFM tip is larger
compared to that of supported graphene parts. These suspended graphene regions
can be deformed with forces of the order of 10 nN. The elastic modulus of
graphene was determined from indentation measurements performed on suspended
membrane regions with diameters in the 100 nm range.Comment: in Journal of Experimental Nanoscience (2016
DNA methylation clock DNAmFitAge shows regular exercise is associated with slower aging and systemic adaptation
DNAmPhenoAge, DNAmGrimAge, and the newly developed DNAmFitAge are DNA methylation (DNAm)-based biomarkers that reflect the individual aging process. Here, we examine the relationship between physical fitness and DNAm-based biomarkers in adults aged 33–88 with a wide range of physical fitness (including athletes with long-term training history). Higher levels of VO 2 max ( ρ = 0.2, p = 6.4E − 4, r = 0.19, p = 1.2E − 3), Jumpmax ( p = 0.11, p = 5.5E − 2, r = 0.13, p = 2.8E − 2), Gripmax ( ρ = 0.17, p = 3.5E − 3, r = 0.16, p = 5.6E − 3), and HDL levels ( ρ = 0.18, p = 1.95E − 3, r = 0.19, p = 1.1E − 3) are associated with better verbal short-term memory. In addition, verbal short-term memory is associated with decelerated aging assessed with the new DNAm biomarker FitAgeAcceleration ( ρ : − 0.18, p = 0.0017). DNAmFitAge can distinguish high-fitness individuals from low/medium-fitness individuals better than existing DNAm biomarkers and estimates a younger biological age in the high-fit males and females (1.5 and 2.0 years younger, respectively). Our research shows that regular physical exercise contributes to observable physiological and methylation differences which are beneficial to the aging process. DNAmFitAge has now emerged as a new biological marker of quality of life
The ornithological collection of the Zoological Museum of Babeș-Bolyai University, Cluj-Napoca, Romania – Part 1: the catalogue of bird skin specimens
This paper reviews the bird skin collection housed in the Zoological Museum of Babeș-Bolyai University, Cluj-Napoca, Romania. The collection includes 925 specimens, belonging to 193 species from 53 families and 20 orders, collected between 1859 and 2021. Due to its historical background and the presence of rare species, it is considered to be one of most important ornithological collections in Eastern Europe. Such a collection can serve as a basis for valuable ornithological studies. Furthermore, a map representation with new distribution data for bird species is provided, which represents a source of information for the status of the avifauna of the Carpathian basin in the 19th and 20th centuries
The ornithological collection of the Zoological Museum of Babeș-Bolyai University, Cluj-Napoca, Romania – Part 1: the catalogue of bird skin specimens
This paper reviews the bird skin collection housed in the Zoological Museum of Babeș-Bolyai University, Cluj-Napoca, Romania. The collection includes 925 specimens, belonging to 193 species from 53 families and 20 orders, collected between 1859 and 2021. Due to its historical background and the presence of rare species, it is considered to be one of most important ornithological collections in Eastern Europe. Such a collection can serve as a basis for valuable ornithological studies. Furthermore, a map representation with new distribution data for bird species is provided, which represents a source of information for the status of the avifauna of the Carpathian basin in the 19th and 20th centuries
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