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Tip-enhanced Raman spectroscopy reveals the structural rearrangements of tau protein aggregates at the growth phase

NANOSCALE 2024年第10期16卷 5294-5301页

作者： Sofinska, Kamila Seweryn, Sara Skirlinska-Nosek, Katarzyna Barbasz, Jakub Lipiec, Ewelina [a]Jagiellonian University Faculty of Physics Astronomy and Applied Computer Science M. Smoluchowski Institute of Physics Łojasiewicza 11 30-348 Krakow Poland [b]Jagiellonian University Doctoral School of Exact and Natural Sciences Krakow Poland [c]Jerzy Haber Institute of Catalysis and Surface Chemistry Polish Academy of Sciences Niezapominajek 8 30-239 Krakow Poland

Tau protein aggregates inside neurons in the course of Alzheimer's disease (AD). Because of the enormous number of people suffering from AD, this disease has become one of the world's major health and social problems. The presence of tau lesions clearly correlates with cognitive impairments in AD patients, thus, tau is the target of potential treatments for AD, next to amyloid-beta. The exact mechanism of tau aggregation has not been understood in detail so far;especially little is known about the structural rearrangements of tau aggregates at the growth phase. The research into tau conformation at each step of the aggregation pathway will contribute to the design of effective therapeutic approaches. To follow the secondary structure of individual tau aggregates at the growth phase, we applied tip-enhanced Raman spectroscopy (TERS). The nanospectroscopic approach enabled us to follow the structure of individual aggregates occurring in the subsequent phases of tau aggregation. We applied multivariate data analysis to extract the spectral differences for tau aggregates at different aggregation phases. Moreover, atomic force microscopy (AFM) allowed the tracking of the morphological alterations for species occurring with the progression of tau aggregation. Tip-enhanced Raman spectroscopy (TERS) enabled the structural differences between tau protein aggregates to be revealed, specifically tau protofibrils and young fibrils at the level of individual aggregates.

关键词： Aggregates

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An improved KNN algorithm based on ensemble methods and correlation 7

An improved KNN algorithm based on ensemble methods and corr...

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7th IEEE International Congress on Information science and Technology, CiSt 2023

作者： Manzali, Youness Barry, Khalidou Abdoulaye Far, Mohamed El Faculty of Sciences Dhar El Mahraz Sidi Mohammed Ben Abdellah University Applied Physics Computer Science and Statistics Laboratory Fez Morocco

ISBN: (纸本)9781665461337

K-Nearest Neighbors is a widely used algorithm due to its simplicity and efficacity. However, KNN suffers from many drawbacks, such as it does not work well with datasets with a high number of features. Also, not all the features contribute to the classification process. To resolve these issues, we present an improved KNN algorithm which uses KNN as a base learner in an ensemble method and correlation for selecting the features subsets. The experiment results show that the proposed algorithm performed better than other machine learning algorithms. © 2023 IEEE.

关键词： Learning algorithms

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ROAR: A Benchmark for NFT Rarity Meters 6

ROAR: A Benchmark for NFT Rarity Meters

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6th IEEE International Conference on Blockchain and Cryptocurrency, ICBC 2024

作者： Belousov, Dmitry Shuklin, Maksim Stepin, Alexander Yanovich, Yury Moscow Institute of Physics and Technology Phystech School of Applied Mathematics and Informatics Moscow Russia Hse University Faculty of Computer Science Moscow Russia Skolkovo Institute of Science and Technology Wireless Center Moscow Russia

ISBN: (纸本)9798350316742

Rarity meters are incorporated by industry and discursive by academia. Rarity, as an intuitive term, attracted numerous researchers to present their own view of it. While there is existing literature on comparing rarity meters, it requires access to NFT collection data, which can be challenging for researchers without a background in blockchain technology. This has created a demand for an easily accessible rarity meter benchmark. In this paper, we introduce the Rating over all Rarities (ROAR) benchmark, which includes data from one hundred popular NFT collections from the Ethereum blockchain, implemented a weighted correlation-based performance measurement function, as well as four state-of-the-art rarity meters (***, Kramer, OpenRarity, and NFTGo), along with a new rarity meter called ROAR. Our experiments show that the ROAR rarity meter, an ensemble of the other four meters, outperforms its competitors, with *** and Kramer as runner-ups. The ROAR benchmark is a tool for examination and testing of rarity meter ideas, and we challenge readers to develop models that can outperform the ROAR rarity meter. © 2024 IEEE.

关键词： Blockchain

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Effective Parametric Optimization of Heating-Cooling Process with Optimum near the Domain Border 11

Effective Parametric Optimization of Heating-Cooling Process...

引用

11th IEEE International Conference on Intelligent Systems, IS 2022

作者： Guzowski, Hubert Smolka, MacIej Byrski, Aleksander Pekar, Libor Oplatkova, Zuzana Kominkova Senkerik, Roman Matusu, Radek Gazdos, Frantisek Agh University of Science and Technology Institute of Computer Science Krakow Poland Tomas Bata University in Zlín Faculty of Applied Informatics Czech Republic

ISBN: (纸本)9781665456562

Heating-cooling processes are widely used in industry and are often subject to latencies and delays. Although the parameters of such processes can be identified using mathematical and physical modeling, this technique is highly demanding both when it comes to the amount of a priori knowledge required and the time it takes to find a solution. In this work, we provide a robust formulation of a time-delay control problem and propose a numerical approach to finding its parameters in a form of an optimization task. Consequently, we apply various techniques and metaheuristics to obtain a high quality solution and discuss key observations made in the process. © 2022 IEEE.

关键词： Time delay

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Socio-cognitive Optimization of Time-delay Control Problems using Evolutionary Metaheuristics 11

Socio-cognitive Optimization of Time-delay Control Problems ...

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11th IEEE International Conference on Intelligent Systems, IS 2022

作者： Kipinski, Piotr Guzowski, Hubert Urbanczyk, Aleksandra Smolka, MacIej Kisiel-Dorohinicki, Marek Byrski, Aleksander Oplatkova, Zuzana Kominkova Senkerik, Roman Pekar, Libor Matusu, Radek Gazdos, Frantisek Agh University of Science and Technology Institute of Computer Science Krakow Poland Tomas Bata University in Zlín Faculty of Applied Informatics Czech Republic

ISBN: (纸本)9781665456562

Metaheuristics are universal optimization algorithms which should be used for solving difficult problems, unsolvable by classic approaches. In this paper we aim at constructing novel socio-cognitive metaheuristic based on castes, and apply several versions of this algorithm to optimization of time-delay system model. Besides giving the background and the details of the proposed algorithms we apply them to optimization of selected variants of the problem and discuss the results. © 2022 IEEE.

关键词： Optimization

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Socio-cognitive Optimization of Time-delay Control Problems using Agent-based Metaheuristics 11

Socio-cognitive Optimization of Time-delay Control Problems ...

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11th IEEE International Conference on Intelligent Systems, IS 2022

作者： Nabywaniec, Mateusz Guzowski, Hubert Urbanczyk, Aleksandra Smolka, MacIej Kisiel-Dorohinicki, Marek Byrski, Aleksander Oplatkova, Zuzana Kominkova Senkerik, Roman Pekar, Libor Matusu, Radek Gazdos, Frantisek Agh University of Science and Technology Institute of Computer Science Krakow Poland Tomas Bata University in Zlín Faculty of Applied Informatics Czech Republic

ISBN: (纸本)9781665456562

Following the introduction of the socio-cognitive caste-based algorithms into the classic evolutionary metaheuristics, in this paper we focus on similar task regarding agent-based universal optimization methods. We tackle EMAS and DE algorithms and enrich them also with TOPSIS-inspired mechanism. Besides giving the details of the methods and the background, we present preliminary results after applying those techniques to solving the problem of optimization of time-delay system model. © 2022 IEEE.

关键词： Time delay

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Local distortions of the crystal structure and their influence on the electronic structure and superconductivity of the high-entropy alloy (TaNb)0.67(HfZrTi)0.33

arXiv

引用

arXiv 2023年

作者： Jasiewicz, Kinga Tobola, Janusz Wiendlocha, Bartlomiej AGH University of Krakow Faculty of Physics and Applied Computer Science Aleja Mickiewicza 30 Krakow30-059 Poland

Local distortions of the crystal structure and their influence on the electronic structure, electron-phonon interaction, and superconductivity are theoretically studied in the superconducting high-entropy alloy (HEA) (TaNb)0.67(HfZrTi)0.33. Distortions of the crystal lattice are caused by the relaxation of atomic positions and are studied in the twelve models of supercells. The largest relative changes in the interatomic distances due to relaxation reach 8%. On average, local distortions tend to lower the density of states at the Fermi level and significantly reduce the electron-phonon coupling parameter λ. As a result, the calculated superconducting critical temperature is reduced to about 50% of the initial value, which shows the strong impact of structural disorder on superconductivity in this prototype high-entropy alloy. With the reduced value of λ, the theoretical Tc is closer to the experiment for typical values of the Columomb pseudopotential parameter µ∗. The experimental Tc can be reproduced by taking a slightly enhanced µ∗ = 0.176, which leaves little room for the possibility of suppression of superconductivity by disorder. Copyright © 2023, The Authors. All rights reserved.

关键词： Electronic structure

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Strong-coupling superconductivity of the Heusler-type compound ScAu2Al: Ab-initio studies

arXiv

引用

arXiv 2023年

作者： Kuderowicz, Gabriel Wiendlocha, Bartlomiej AGH University of Krakow Faculty of Physics and Applied Computer Science Aleja Mickiewicza 30 Krakow30-059 Poland

The ScAu2Al superconducting Heusler-type compound was recently characterized to have the highest critical temperature of Tc = 5.12 K and the strongest electron-phonon coupling among the Heusler family. In this work, the electronic structure, phonons, electron-phonon coupling, and superconductivity of ScAu2Al are studied using ab initio calculations. The spin-orbit coupling significantly changes the electronic structure removing the van Hove singularity from the vicinity of the Fermi level. In the phonon spectrum, low frequency acoustic modes, additionally softened by the spin-orbit interaction, strongly couple with electrons, leading to the electron-phonon coupling constant λ = 1.25, a record high among Heuslers. The density functional theory for superconductors is then used to analyze superconducting state in this two-band superconductor. The effect of spin fluctuations (SF) on superconductivity is also analyzed. The calculated critical temperatures of Tc = 5.16 K (4.79 K with SF) agree very well with the experiment, confirming the electron-phonon mechanism of superconductivity and showing a weak spin-fluctuations effect. The superconducting gaps formed on two Fermi surface sheets exhibit moderate anisotropy. Their magnitudes confirm the strong coupling regime, as the reduced average values are 2∆b1/kBTc 4.1 and 2∆b2/kBTc 4.3. Anisotropy of the gaps and large spread in their values significantly affect the calculated quasiparticle density of states. Copyright © 2023, The Authors. All rights reserved.

关键词： Spin fluctuations

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Momentum dependent measures of correlations between mean transverse momentum and harmonic flow in heavy ion collisions

arXiv

引用

arXiv 2023年

作者： Samanta, Rupam Bozek, Piotr AGH University of Krakow Faculty of Physics and Applied Computer Science aleja Mickiewicza 30 Cracow30-059 Poland

The correlation between the mean transverse momentum and the harmonic flow coefficients is an observable which is of great interest;it is sensitive to shape fluctuations in the initial state of a relativistic nuclear collision. The measurement of that correlation coefficient in central collisions allows one to infer about the intrinsic deformation of the colliding nuclei. We propose to study the momentum dependent covariance and correlation coefficient between the mean transverse momentum and the harmonic flow in a given transverse momentum bin. Two possible constructions of such observables are provided and predictions are obtained from a viscous hydrodynamic model. We find that such momentum dependent correlation coefficients between the mean transverse momentum and the harmonic flow show a strong and nontrivial momentum dependence. We also explore the effects of granularity (nucleon width) in the initial state, the nuclear deformation, and the shear viscosity on this momentum dependent correlation coefficient. The shape of the momentum dependence of the correlation coefficient for the triangular flow is found to be sensitive to the size of small scale fluctuations in the initial state. On the other hand, the shape of the momentum dependence of the covariance between the mean transverse momentum and the harmonic flow coefficients is found to be sensitive to the value of the shear viscosity and to the granularity of the initial state. © 2023, CC BY.

关键词： Momentum

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Modelling of diffraction of X-rays in perovskite superlattices 7

Modelling of diffraction of X-rays in perovskite superlattic...

引用

7th International Conference of Computational Methods in Engineering science, CMES 2022

作者： Kokosza, L. Mitura, Z. Department of Applied Computer Science and Modelling Faculty of Metals Engineering and Industrial Computer Science AGH University of Science and Technology al. Mickiewicza 30 Kraków30-059 Poland

Nowadays, different perovskite structures are widely investigated because they can be potentially used in many branches of industry. If two materials are deposited alternately on a substrate, then a superlattice having some unique properties can be formed. However, X-ray intensity distributions for perovskite superlattices, especially for very thin films, are difficult to be computationally determined, because many different parameters need to be considered to reproduce a superstructure of a sample. The main purpose of this work is to demonstrate how basic intensity distributions can be generated for perovskites, XRD technique and how to improve results using specific numerical methods. The computer application with a user-friendly graphical interface has been developed employing Unity software (with 3D graphics tools) and Oracle Database (through Oracle Cloud Infrastructure). The calculations are based on the kinematical theory of diffraction. The values of some important parameters and the results are stored in the assigned database. It is assumed that epitaxial superlattices can be prepared on substrates using molecular beam epitaxy or pulsed laser deposition methods. The desktop application allows for designing samples of different thicknesses and combinations of monolayers. The results are more realistic if Monte Carlo simulations are done although longer computation time is required. The software developed should be helpful to compare in detail virtual model results with experimental data. © 2022 Institute of physics Publishing. All rights reserved.

关键词： Perovskite

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