Potential Limitations Research Articles

Electrochemical Technology for the Detection of Tau Proteins as a Biomarker of Alzheimer’s Disease in Blood

Alzheimer’s disease (AD) is a prevalent neurodegenerative disorder and a significant cause of dementia in elderly individuals, with a growing prevalence in our aging population. Extracellular amyloid-β peptides (Aβ), intracellular tau proteins, and their phosphorylated forms have gained prominence as critical biomarkers for early and precise diagnosis of AD, correlating with disease progression and response to therapy. The high costs and invasiveness of conventional diagnostic methods, such as positron emission tomography (PET) and magnetic resonance imaging (MRI), limit their suitability for large-scale or routine screening. However, electrochemical (EC) analysis methods have made significant progress in disease detection due to their high sensitivity, excellent specificity, portability, and cost-effectiveness. This article reviews the progress in EC biosensing technologies, focusing on the detection of tau protein biomarkers in the blood (a low-invasive, accessible diagnostic medium). The article then discusses various EC sensing platforms, including their fabrication processes, limit of detection (LOD), sensitivity, and clinical potential to show the role of these sensors as transformers changing the face of AD diagnostics.

Detection of Bagaza Virus in Europe: A Scoping Review

The Bagaza virus (BAGV) belongs to the genus Orthoflavivirus (Ntaya serocomplex) and emerged in Europe, Spain, in 2010. The natural transmission cycle of this virus is perpetuated by Culex spp. mosquitoes and viraemic birds. The ability of BAGV to cause infection in several game birds from the family Phasianidae has been well-studied. BAGV is antigenically similar to other orthoflaviviruses from the Japanese encephalitis serocomplex, such as the West Nile and Usutu viruses, a circumstance which can lead to cross-reactivity in less specific serological techniques (e.g., ELISA). Severe implications in animal health has already been described, but some aspects of the dynamics of transmission and the limits of zoonotic potential of BAGV still need to be clarified. Further investigation focused on epidemiological surveillance in high-risk areas would be beneficial for prevention and control of new outbreaks. The present study is a systematic review of the BAGV reports in Europe.

ИННОВАЦИИ В СЕЛЬСКОМ ХОЗЯЙСТВЕ: ВЛИЯНИЕ НА ПРОДОВОЛЬСТВЕННУЮ БЕЗОПАСНОСТЬ

Modern challenges such as climate change, population growth and degradation of natural resources require the implementation of innovative solutions in agriculture. This arti-cle examines the impact of technological, environmental and organizational innovations on key aspects of food security, including accessibility, quality and sustainability of food systems. Key achievements in precision agriculture, biotechnology and digitalization are considered, and po-tential limitations and risks associated with their implementation are analyzed. A conclusion is made about the importance of innovations for ensuring sustainable development of the agricul-tural sector in the context of global challenges.

Refined cyclic renormalization group in Russian doll model

Focusing on Bethe-Ansatz integrable models, robust to both time-reversal symmetry breaking and disorder, we consider the Russian Doll Model (RDM) for finite system sizes and energy levels. Suggested as a time-reversal-symmetry breaking deformation of Richardson’s model, the well-known and simplest model of superconductivity, RDM revealed an unusual cyclic renormalization group (RG) over the system size NN, where the energy levels repeat themselves, shifted by one after a finite period in \ln NlnN, supplemented by a hierarchy of superconducting condensates, with the superconducting gaps following the so-called Efimov (exponential) scaling. The equidistant single-particle spectrum of RDM made the above Efimov scaling and cyclic RG to be asymptotically exact in the wideband limit of the diagonal potential. Here, we generalize this observation in various respects. We find that, beyond the wideband limit, when the entire spectrum is considered, the periodicity of the spectrum is not constant, but appears to be energy-dependent. Moreover, we resolve the apparent paradox of shift in the spectrum by a single level after the RG period, despite the disappearance of a finite fraction of energy levels. We also analyze the effects of disorder in the diagonal potential on the above periodicity and show that it survives only for high energies beyond the energy interval of the disorder amplitude. Our analytic analysis is supported with exact diagonalization.

Upper Bound for the Grand Canonical Free Energy of the Bose Gas in the Gross–Pitaevskii Limit for General Interaction Potentials

AbstractWe consider a homogeneous Bose gas in the Gross–Pitaevskii limit at temperatures that are comparable to the critical temperature for Bose–Einstein condensation. Recently, an upper bound for the grand canonical free energy was proved in Boccato et al. (SIAM J Math Anal 56(2):2611–2660, 2024) capturing two novel contributions. First, the free energy of the interacting condensate is given in terms of an effective theory describing the probability distribution of the number of condensed particles. Second, the free energy of the thermally excited particles equals that of a temperature-dependent Bogoliubov Hamiltonian. We extend this result to a more general class of interaction potentials, including interactions with a hard core. Our proof follows a different approach than the one in Boccato et al. (SIAM J Math Anal 56(2):2611–2660, 2024): We model microscopic correlations between the particles by a Jastrow factor and exploit a cancellation in the computation of the energy that emerges due to the different length scales in the system.

Black currant cultivars, developed at the Polli Horticultural Research Center (Estonia), in Northwest Russia

Background. Introduction of new foreign cultivars makes it possible to expand the limits of the genetic potential of the VIR collection. A comprehensive study of such germplasm accessions is important for identifying sources of traits useful for breeding and the best cultivars for practical utilization. Materials and methods. Eight black currant cultivars released in Estonia were studied from 2015 through 2023 at Pushkin and Pavlovsk Laboratories of VIR. Conventional methods were used to test their adaptability and assess their main productivity indicators and berry quality. The resulting data were statistically processed in Microsoft Excel according to the guidelines by B. A. Dospekhov. Results and conclusion. The studied cultivars appeared well adapted to the environments of Northwest Russia. The heat supply in Leningrad Province is optimal for their cultivation. Good adaptability, synchronized fruit ripening, stable yields, and fine taste of berries were demonstrated by cvs. ‘Almo’ (k-44169), ‘Albos’ (k-44167), ‘Elo’ (k-44171), ‘Karri’ (k-44172), ‘Mulgi Must’ (k-38061), ‘Musti’ (k-44173), and ‘Varmas’ (k-44174). They are recommended for amateur gardens in Northwest Russia. Cv. ‘Karri’ (k-44172) is a promising source of such traits as good self-fertility, large fruit size, stable yield, well-balanced taste, high anthocyanin content in berries, and resistance to American powdery mildew and gall mite. Cv. ‘Varmas’ is a source of earliness, high self-fertility, and dessert taste of berries.

Assessment of Free Energy Functions for Sand

ABSTRACTThe advantages of constitutive models in energy‐conservation frameworks have been widely addressed in the literature. A key component is choosing an appropriate energy potential to derive the hyperelastic constitutive equations. This article investigates the advantages and limitations of different energy potentials found in the literature based on mathematical conditions to guarantee numerical stability, such as the desired order of homogeneity, positive and non‐singular stiffness within the application range, and equivalent Poisson's ratio from a constitutive modelling standpoint. Potentials meeting the aforementioned criteria are employed to simulate the response envelopes of Karlsruhe fine sand (KFS). Moreover, the performance of the potentials, in conjunction with plasticity theories, is examined. To achieve this, the hyperelastic constitutive equations have been coupled with the bounding surface plasticity model of Dafalias and Manzari to reproduce the soil response in a hyperelastic–plastic frame. Finally, one of the potentials is modified, whereas recommendations for incorporating other appropriate free energy functions into different soil constitutive models are presented. Furthermore, 100 closed elastic strain cycles have been simulated with the bounding surface plasticity model of Dafalias and Manzari considering the original hypoelastic stiffness and hyperelastic–plastic constitutive equations. Using the hypoelastic framework in the simulation led to stress accumulation after 100 closed elastic strain loops, while a reversible response was predicted using the hyperelastic stiffness tensor.

Optical Dynamics of Picosecond Pulse Trains in Aluminum and Zinc Tetracarboxy-Phthalocyanines

The nonlinear properties and photophysical dynamics of aluminum and zinc tetracarboxy-phthalocyanines (AlPc and ZnPc) were studied using pulse trains of a 532 nm wavelength, which contain 25 subpulses with a 100 ps width and 13 ns spacing. Considering its interaction with long-duration pulses, the energy structure of phthalocyanine could be substituted by a five-level pattern. The nonlinear transmissions of pulse trains in AlPc and ZnPc were simulated by means of equations about the population rate coupled with the paraxial field equation of two-dimensional space. The well-known Crank–Nicholson numerical method was applied to the theoretical simulation. The results demonstrate that both phthalocyanines are efficient as optical limiters. In its low-intensity region, AlPc shows a much better OL effect than ZnPc. But in the region with high intensity, their energy transmittances are nearly the same. The nonlinear transmission of a pulse is susceptible to the state lifetime and cross section of one-photon absorption. Tetracarboxy-phthalocyanines have advantageous photophysical properties for applications in nonlinear optical areas, such as nonlinear optical devices like optical limiters. Adding central metals such as Al and Zn to phthalocyanines could enhance their photodynamic properties, making them potential optical limiters and photosensitizers.

Stability and dissolution of single-crystalline iron oxide thin films in electrochemical environments

Stability and dissolution of single-crystalline iron oxide thin films in electrochemical environments

Deterministic 3-server on a circle and the limitation of canonical potentials

Deterministic 3-server on a circle and the limitation of canonical potentials

Weak solutions of anisotropic (and crystalline) inverse mean curvature flow as limits of p-capacitary potentials

Weak solutions of anisotropic (and crystalline) inverse mean curvature flow as limits of p-capacitary potentials

(Invited) Fundamentals of Single Atom Alloy Catalysts for Electrochemical Nitrate Reduction to Ammonia

Electrochemical conversion of toxic nitrate into useful ammonia provides a route to remediating the most frequent water pollutant while simultaneously generating one of the most produced bulk chemicals. While highly desirable, this conversion is plagued by complications including a highly branching reaction pathway - which can produce highly toxic undesirable products, the need to reduce a negatively charged species, a relatively low nitrate concentration, and competition for electrons between nitrate reduction and parasitic hydrogen evolution. Therefore, electrocatalysts must be developed which are highly selective not only for nitrate over other species in the water matrix, but also selective to the desired ammonia product. Single atom alloy catalysts, where a single atom of one element is embedded in a solvating phase of a secondary element, provides an opportunity to engineer catalysts with atomic level precision. In this presentation, we will outline the fundamental behavior of single atom alloy for nitrate reduction. We explore this topic through density functional theory calculations of the reaction mechanisms, including thermodynamics and kinetic aspects. Particularly, we will discuss the effect of single atom identity, effect of matrix element, and pH and potential. We show that the ability of the single atom to localize the N* species drives the reduction towards ammonia formation, as exemplified by Ru in Cu, while facile exchange of N* between the single atom site and the matrix leads to the formation of N2 or other undesirable products, as exemplified by Pd in Cu and Au in Cu, respectively. We also discuss the importance of the selection of the solvating element; for example, Cu is a good solvating metal because it is a good conductor, while minimizing the hydrogen evolution reaction. Further, we discuss the limits of pH and potential on the performance. In general, higher pH and more moderately negative potentials favor nitrate reduction to NH3 or N2, while lower pH and more negative potentials drive H2 evolution, and generation of NOx species.

Unveiling Optical Nonlinearity: Exploring Nickel‐Curcumin Complexes through Z‐Scan and Degenerate Four Wave Mixing Techniques

AbstractTwo Curcumin (Cur) based mixed ligand complexes of Nickel have been investigated for their optical nonlinearity (NLO). Physicochemical characterization of two nickel precursors and their interaction with curcumin produced two molecules, namely Ni(C3S5)(Cur).2H2O (abbreviated as NiThCur) and NiCl(Cur)(PPh3) (abbreviated as NiTppCur). Additionally the Conceptual‐Density‐Functional‐Theory (CDFT) studies were performed. CDFT‐based optimization parameters of both molecules are theoretically interpreted. HOMO‐LUMO energy gap of NiThCur and NiTppCur were calculated 1.474 eV and 2.744 eV respectively. Both molecules demonstrated good NLO activities, studied by a Z‐scan approach and additionally with a Differential Four wave Mixing (DFWM) technique. Preliminarily investigations showed that the molecules can be potential optical limiters (OL). These studies divulge the exhibition of a 3‐photon absorption (3PA) mechanism by the synthesized molecules. NLO absorption 3PA coefficient (γ) value of 1.34×10−24 m3/W2, third‐order optical susceptibility (χ(3)) value of 1.543×10−11 esu, and the figure of merit 6.64×10−14 esu was observed for the NiThCur complex and γ=3.61×10−24 m3/W2, χ(3)=1.521×10−11 esu, and FoM=5.61×10−14 esu for NiTppCur with Z‐scan (γ and χ(3)) and DFWM methods, respectively. Normalized transmittance (NT) exhibited a decrease to 78.5 % from 100 % in NiThCur and to 69.5 % in NiTppCur. Optical limiting calculations are also presented.

In silico antibacterial, anticancer, antioxidant, antidiabetic activity predictions of the dual organic peroxide 2,5-dimethyl-2,5-di(tert-butyl peroxyl)hexane

In this search organic peroxide has been studied for its potential biological activities in various fields, including medicine and biotechnology. Molecular docking studies have been conducted to predict the binding between organic peroxide and certain biological targets, such as the breast cancer receptor 3hb5-oxidoreductase and the prostate cancer mutant 2q7k-Hormone. The docking results indicate potential interactions between peroxide and these targets. In addition to its potential cytotoxic activity, organic peroxide has been investigated for its antidiabetic activity. The docking results suggest that peroxide binds to the active site of enzymes involved in diabetes, such as α-amylase, pancreatic lipase, and β-glucosidase, with low binding energies. This indicates a potential role for peroxide in the treatment of diabetes. Furthermore, the interaction between peroxide and the antioxidant protein IHD2 (2HCK) has been explored. These computational studies suggest a possible pharmacological role for peroxide in the treatment of Helicobacter pylori (H. pylori) infection. The docking energy between peroxide and Helicobacter pylori adhesin HopQ type I bound to the N-terminal domain of human CEACAM1 indicates that peroxide could be a potential target to inhibit H. pylori infection. It’s important to note that these findings are based on computational methods and molecular docking studies. Further research, including in vitro and in vivo experiments, would be necessary to validate these findings and fully understand the potential benefits and limitations of peroxide in these applications.

Deciphering diffuse scattering with machine learning and the equivariant foundation model: the case of molten FeO

Bridging the gap between diffuse x-ray or neutron scattering measurements and predicted structures derived from atom–atom pair potentials in disordered materials, has been a longstanding challenge in condensed matter physics. This perspective gives a brief overview of the traditional approaches employed over the past several decades. Namely, the use of approximate interatomic pair potentials that relate three-dimensional structural models to the measured structure factor and its’ associated pair distribution function. The use of machine learned interatomic potentials has grown in the past few years, and has been particularly successful in the cases of ionic and oxide systems. Recent advances in large scale sampling, along with a direct integration of scattering measurements into the model development, has provided improved agreement between experiments and large-scale models calculated with quantum mechanical accuracy. However, details of local polyhedral bonding and connectivity in meta-stable disordered systems still require improvement. Here we leverage MACE-MP-0; a newly introduced equivariant foundation model and validate the results against high-quality experimental scattering data for the case of molten iron(II) oxide (FeO). These preliminary results suggest that the emerging foundation model has the potential to surpass the traditional limitations of classical interatomic potentials.

Soliton gas: Theory, numerics, and experiments.

The concept of soliton gas was introduced in 1971 by Zakharov as an infinite collection of weakly interacting solitons in the framework of Korteweg-de Vries (KdV) equation. In this theoretical construction of a diluted (rarefied) soliton gas, solitons with random amplitude and phase parameters are almost nonoverlapping. More recently, the concept has been extended to dense gases in which solitons strongly and continuously interact. The notion of soliton gas is inherently associated with integrable wave systems described by nonlinear partial differential equationslike the KdV equationor the one-dimensional nonlinear Schrödinger equationthat can be solved using the inverse scattering transform. Over the last few years, the field of soliton gases has received a rapidly growing interest from both the theoretical and experimental points of view. In particular, it has been realized that the soliton gas dynamics underlies some fundamental nonlinear wave phenomena such as spontaneous modulation instability and the formation of rogue waves. The recently discovered deep connections of soliton gas theory with generalized hydrodynamics have broadened the field and opened new fundamental questions related to the soliton gas statistics and thermodynamics. We review the main recent theoretical and experimental results in the field of soliton gas. The key conceptual tools of the field, such as the inverse scattering transform, the thermodynamic limit of finite-gap potentials, and generalized Gibbs ensembles are introduced and various open questions and future challenges are discussed.

The diffusive limit of Boltzmann equation in torus

The Boltzmann equation of kinetic theory gives a statistical description of a gas of interacting particles. It is well known that the Boltzmann equation is related to the Euler and Navier–Stokes equations in the field of gas dynamics. In this paper we are concerned with the incompressible Navier–Stokes–Fourier limit of the Boltzmann equation. We prove the incompressible Navier–Stokes–Fourier limit globally in time and the time decay rate of the solution to the rescaled Boltzmann equation in a torus. For ɛ small, by using the truncated expansion and Lx,v2 – Lx,v∞ method, we prove such a limit for the general potentials γ∈(−3,1] .

On the problem of definition of the legal formalism concept

The article examines the problems of doctrinal understanding of the phenomenon of legal formalism in Russian legal science by contrasting it with the concept of normoscepticism, as well as limits of regulatory potential of law enforcement with a formal legal approach in judicial practice. The relevance of this problem is due both to the presence of significant gaps in domestic legal science in terms of studying the phenomenon of legal formalism and its definition, and to the requests of existing judicial practice, in which, as follows from the decisions of higher judicial instances, abuse of the form of law is often found, in connection with which there are a number of indications of the inadmissibility of a formal dogmatic approach when considering cases. At the same time, disregard for formally established legislative prescriptions is also obviously unacceptable, since it is fraught with extremely negative consequences, up to the manifestation of so called «judicial arbitrariness» when considering individual cases.

S-matrix positivity without Lorentz invariance: a case study

We investigate the analytic structure of scattering amplitudes in theories in which Lorentz invariance is spontaneously broken. We do so by computing and studying the S-matrix for a simple example: a superfluid described by a complex scalar with quartic interactions. The computation is confined to tree-level, for there are no absolutely stable single-particle states, though the lifetime can be made long by lowering the chemical potential. For the 2 → 2 amplitude in center-of-mass configurations, not only is crossing symmetry violated, there appears a tree level branch cut for unphysical kinematics. Its appearance is a consequence of non-analyticity in the dispersion relation. The branch point defines a new scale in the problem, which scales inversely with the chemical potential. In this example, even derivatives of the forward amplitude are positive while odd derivatives are negative. This pattern can be understood in a general way in the limit of a small chemical potential, or weak Lorentz breaking.

Novel third order nonlinear optical stilbazolium crystal replaced with 3-methoxy benzaldehyde as donor for optical device applications

Novel third order nonlinear optical stilbazolium crystal replaced with 3-methoxy benzaldehyde as donor for optical device applications