Solution Structure Research Articles

Ion Mobility-Mass Spectrometry Captures the Structural Consequences of Lipid Nanoparticle Encapsulation on Ribonucleic Acid Cargo.

Ribonucleic acids (RNAs) are becoming increasingly significant in our search for improved biotherapeutics. RNA-based treatments offer high specificity, targeted delivery, and potentially lower-cost options for various debilitating human diseases. Despite these benefits, there are still relatively few FDA-approved RNA-based therapies, with the notable exceptions being the mRNA (mRNA) COVID-19 vaccines, which are delivered using lipid nanoparticle (LNP) systems. LNPs are distinctive drug delivery systems (DDSs) because of their ability to target specific cells, their biocompatibility, and their efficiency in merging with cellular membranes to enhance treatment effectiveness. While the biophysical landscapes of RNA structures in solution are relatively well understood, the impact of the LNP environment on RNA remains less clear. This study uses native ion mobility-mass spectrometry (IM-MS) and collision-induced unfolding (CIU) techniques to investigate how LNP encapsulation affects RNA structure and stability. We examine how various factors, such as ionization polarity, cofactor binding, lipid types, and lipid ratios, influence LNP-released RNA cargo. Our findings reveal that LNP DDSs induce significant changes in the structures and stabilities of their RNA cargo. However, the extent of these changes strongly depends on the type and composition of the lipids used. We conclude by discussing how IM-MS and CIU can aid in the continued development of more efficient LNP DDSs and improve DDS selection methodologies overall.

Design strategy for an automotive lens with a wide field of view

To solve the problems in designing a wide field of view (FOV) automotive lens, such as the complicated initial structure solution when using aberration theory and the limited scaling method, a novel design strategy, to the best of our knowledge, based on the compression ratio of field angle is proposed. The wide-FOV automotive lens is first divided into two groups, front and rear lenses, and each group is designed with several parallel plates as starting points using SYNOPSYS software. Then, the two groups are connected as a whole initial optical system. Finally, an iterative process is applied to improve the performance of the initial structure. A wide-FOV automotive lens is designed to verify the feasibility and effectiveness of the design method proposed in this paper. The wide-FOV automotive lens has the characteristics of good imaging quality, large aperture, and small size and consists of six spherical lenses. The result of the design indicates that this method based on the compression ratio of field angle is simple, effective, fast in convergence, and provides a good starting point for the design of a wide-FOV automotive lens.

Protein condensates unfold G-quadruplex resembling a helicase activity.

Membrane-less organelles, formed by liquid-liquid phase separation, participate in many vital cellular processes and have received extensive attention recently. A notable form of noncanonical nucleic acid secondary structure, G-quadruplex (G4), interacts with the scaffolding proteins in these membrane-less organelles and becomes an integral part of this condensed phase. However, the structure and stability features of the integrated G4 remain poorly characterized. Herein, we employed NMR along with other biophysical methods to investigate the conformation of a G4 within condensates formed by a disordered protein known as DDX4N1. We discovered that the human telomeric sequence MHT24, which forms a G4 structure in a non-condensed phase solution of protein DDX4N1, unfolds when it is within DDX4N1 condensates due to phase separation. Our findings provide an instance of a protein acquiring new functionality through phase separation process, which deepen our understanding of how protein condensates regulate G4 structure and their functions.

A Mathematically Optimized Design Solution for Structure of PEMFC Catalyst Layer Based on a Two-Phase Flow Model

Abstract Proton exchange membrane fuel cells (PEMFCs) have emerged as a promising solution as the world is moving toward sustainable energy resources. However, in order to compete economically with existing technologies, further improvements in performance are necessary. Mathematical modeling and optimization are viable tools for designing better PEMFCs. This study aims to provide a framework for topological optimization of the electrode structure, with the ultimate goal of enhancing cell performance. To achieve this, a two-phase flow model of PEMFC is developed to characterize the cell performance. The model is then coupled with a topology optimization technique, which is the main focus of the present work, to seek an optimized constituent distribution in the catalyst layer. Results indicate that an electrode with a heterogeneous structure can enhance the overall cell performance by balancing various transport and rate processes. The optimized designs are investigated for various key factors, including effective diffusivity, effective conductivity, and liquid water management, to demonstrate how an optimized design can be advantageous.

Optimization and Structural Analysis of Automotive Battery Packs Using ANSYS

The development of new energy vehicles, particularly electric vehicles, is robust, with the power battery pack being a core component of the battery system, playing a vital role in the vehicle’s range and safety. This study takes the battery pack of an electric vehicle as a subject, employing advanced three-dimensional modeling technology to conduct static and dynamic analyses. Through weight reduction and structural optimization, an innovative power battery pack design scheme is proposed, aiming to achieve a more efficient and lighter electric vehicle power system. The main research tasks are as follows: Firstly, we designed the main load-bearing components of a certain electric vehicle’s power battery pack and established a three-dimensional (3D) model. Then, the model was simplified according to the actual stress conditions of the power battery pack of the electric vehicle and imported into finite element analysis (FEA) software. Next, based on the fundamental principles of the finite element method (FEM), we conducted static analyses under three conditions: bumpy road sharp left turn, bumpy road sharp right turn, and bumpy road emergency braking. The analysis results indicate that the strength of the battery pack meets the allowable requirements, suggesting that the lower housing design has significant redundancy, providing guidance for subsequent optimization. Finally, through modal analysis, we extracted the first six modes of the power battery box, with the first mode frequency being 33.69 Hz. This suggests that the battery pack may experience resonance during actual operation. Based on the static and modal analysis results, we proposed a structural optimization and lightweight design solution for a certain electric vehicle battery pack and compared it with the pre-optimization data.

A Rare Example of a Gallium-Based Lewis Superacid: Synthesis and Reactivity of Ga(OTeF5)3.

The Lewis superacid Ga(OTeF5)3 has been synthesized and characterized, revealing a monomeric structure in solution and a dimeric structure in the solid state. Isolated adducts of Ga(OTeF5)3 with strong and weak Lewis bases have been characterized spectroscopically as well as by single-crystal X-ray diffractometry. The Lewis acidity of this new species has been evaluated by means of different experimental and theoretical methods, which has allowed to classify it as one of only a few examples of a gallium-based Lewis superacid. The high Lewis acidity of Ga(OTeF5)3 was used to amplify the strength of the Brønsted acid HOTeF5, leading to the protonation of diethyl ether. Furthermore, Ga(OTeF5)3 was utilized to access the strong oxidizing system Ga(OTeF5)3/Xe(OTeF5)2 in SO2ClF, which was successfully employed in the synthesis of the dimethyl chloronium salt [Cl(CH3)2][Ga(OTeF5)4], a strong electrophilic methylation reagent.

Variant Analysis of the Ownership Structure of Land Intended for Single-family Housing

The most frequently preferred solution for the ownership structure of land for single-family housing in Poland is the structure of one cadastral plot – one single-family building. However, changing architectural concepts allow for the creation of single-family housing estates in systems consisting of atrial houses or T-type buildings, which have much more advantages than traditional terraced or semi-detached buildings. These advantages result from a different solution of building forms, which can be combined not only in rows, but also in variously shaped groups consisting of many houses. This provides greater possibilities for the free shaping of development plans for groups of houses, which in turn can be combined in various spatial arrangements while maintaining the required conditions of individual entrance, proper lighting of rooms and mutual distances. At the same time, it allows for more intensive use of the area. Despite the indicated advantages, in the light of the observed implementation practice, it seems problematic to locate buildings with separate ownership, used individually on a plot of land used jointly. The article analyzes the possibilities of legal solutions in the area of land and buildings that can be applied in such a solution. The strengths and weaknesses of each solution were assessed and their opportunities and threats were indicated. For the purposes of this research, four differently shaped groups of buildings consisting of T houses were selected. The results were presented in a SWOT analysis for the development variants adopted for the research using the T house as a repeatable residential unit. The article proposes four legal and neighborly solutions that enable and promote the construction of housing estates using highly intensive atrial development based on the T-house.

One-pot synthesis of transition metals-doped LiAl-LDHs to improve lithium adsorption performance and stability

Transition metal doping of Li/Al-LDHs can alter the interlayer spacing and surface charge of LDHs, thereby enhancing adsorption performance and stability. To investigate the rules and mechanisms governing the enhancement of stability and adsorption capacity of Li/Al-LDHs through transition metal element doping, several transition metal elements (Co, Zn, Mn, Zr, and Ni) were selected, and the five types of transition metal-doped Li/Al-LDHs and one undoped Li/Al-LDHs were synthesized by a one-pot method. Compared to the original Li/Al-LDHs, the Co-doped Li/Al-LDHs exhibited higher adsorption capacity, lower dissolution loss, and greater stability. Additionally, after Co doping, the lattice constant of Li/Al-LDHs decreases, effectively reducing the intercalation energy and increasing lithium diffusion efficiency. When used for lithium adsorption, Co-Li/Al-LDHs exhibited a Li+ capacity of 12.6 mg/g and reached saturation adsorption within 90 min. Notably, Co-Li/Al-LDHs achieved a high Li+ adsorption capacity (6.46 mg/g) in East Taigener salt-lake brine. After 10 cycles, the adsorption capacity did not show any significant change, and after 336 h adsorption-desorption cycles (200 rmp, oscillation), the total Al dissolution loss was only about 0.035 ‰, demonstrating that Co doping can enhance the interlayer binding force of Li/Al-LDHs, thereby reducing the decomposition of the layered structure in solution, lowering aluminum dissolution loss, and improving structural stability. The results show that doping with transition metals can reduce the Al dissolution rate of LDHs, and Co-Li/Al-LDHs can be used as an efficient adsorbent for lithium extraction from salt lake and have higher stability.

The Elevated Temperature Tribological Performance of Tough and Superhard TaMoN-Ag films with Solute and Nanocomposite Structures

Abstract Films have been prepared with not only high hardness to guarantee excellent wear resistance but also high toughness to prevent brittle fracture at low to middle-high temperatures. On the basis of ternary transition metal nitrides with significantly improved hardness and toughness, TaMoN-Ag films with solute and nanocomposite structure were prepared by DC magnetron sputtering technology. Friction wear tests were performed between room temperature (RT) and 700 °C. When doping with trace amounts of Ag atoms (∼1.12 at.%, 4 W), TaMoN-Ag films maintain solid solution structure. TaMoN-Ag films with the Ag target power is 4 W show the highest hardness (H∼62.1 GPa), which is 58% higher than TaMoN film and 44% better than that of TaMoN films. Meanwhile, a lower wear rate (KIC∼5.87×10-7 mm3/N·m) is obtained. The tribological properties of TaMoN-Ag films at room temperatures are related to the H3/E2 and lubricious Ag phase, while the tribological properties at high temperatures are mainly due to the formation of lubricating binary metal oxides (AgxTMyOz (Magnéli phases)). The composite films generally have good resistance to plastic deformation.

Introduction to the Investigation of reproduction of the real geometry of UBM panels

The article concisely describes UBM technology (Ultimate Building Machine), that can be used as a solution for buildings and roof structures. The structure of this technology is made of double corrugated thin-walled steel profiles manufactured on the construction site by a self-contained UBM manufacturing factory on wheels. These panels serve as both the building envelope and the structural system. The specificity of the construction poses many design problems, especially the determination of the strength parameters and stiffness of the double-corrugated panels from which the structure is made. The article presents the results of spatial scanning tests of double-corrugated steel sheets, which were carried out using commonly available 3D scanning devices: Leica 3D Disto and MagiScan app. Additionally, results of numerical analyses performed on scanned samples and a comparison of these results with preliminary laboratory tests have been presented in the article. The purpose of scanning was to obtain an accurate and real geometry of the UBM panels, to implement it into a numerical software, and then to perform numerical analyses. Commonly available 3D scanning devices were used because using advanced 3D scanners is not popular nowadays for economic reasons, and hand-built geometric models pose a lot of problems and are not accurate enough. Promising results were obtained, which form the basis for further research.

4hJCHOCH Spin Coupling in a Lewisx Trisaccharide as Evidence of Inter-Residue C-H···O Hydrogen Bonding in Aqueous Solution.

Prior studies of the solution conformation of the Lewisx (Lex) trisaccharide, αFuc-(1→3)[βGal-(1→4)]-βGlcNAc, suggest that nonclassical inter-residue C-H···O hydrogen bonding in aqueous solution contributes to the stabilization of its 3D structure and affects its biological properties. Experimental evidence for this hydrogen bond in aqueous solution has been reported in the form of a 4hJCHOCH NMR spin-coupling constant between C5'Fuc and H1″Gal measured by 2D NMR methods in unlabeled samples. A methyl glycoside of Lex (MeβLex) was prepared containing selective 13C-labeling at C5'Fuc, and the H1″Gal signal was examined in high-field 1H NMR spectra for evidence of splitting or line-broadening caused by the 13C at C5'Fuc. High-resolution 1H NMR spectra obtained at high field and at different temperatures using different FID processing parameters showed no resolved splitting of the H1″Gal signal or evidence of line-broadening. Spectral simulation showed that this splitting and/or line-broadening would be observable if the reported J-value (∼1.1 Hz) is correct. DFT calculations on MeβLex and a carbon analog (O5″Gal replaced by a CH2 group) gave very small and nearly identical calculated 4hJC5',H1″ values, suggesting that the coupling is essentially zero. DFT calculations also showed that an alternate inter-residue 3hJH5',H1″ is small. Based on NMR analyses and DFT calculations, we found that 4hJC5',H1″ in MeβLex has an upper limit of ∼0.4 Hz and that the value could be lower, possibly zero, calling into question its value as experimental proof of persistent nonclassical hydrogen bonding in aqueous solutions of MeβLex and related structures.

Why structural solutions for flood control should be adapted to climate change?

Why structural solutions for flood control should be adapted to climate change?

Taxon Boundaries Unifying Homogeneous Territories by Geocomplex Features in Climatic Zonation

Road-building climatic zonation developed in the 1950s for the territory of the former Soviet Union, does not take into account natural climatic conditions of many regions occupying a significant area of Russia, which limits periods between the highway repair. The development of new territories, for example, the vast Arctic zone, requires a methodological approach from various organizations to the areas by the geographical complex, within which the same type of road structures will be characterized by the same strength and stability. To date, there is no unified, standardized methodology of road-building climatic zonation, providing the required level of reliability of structural and technological solutions at design and construction stages of roads.Purpose: To summarize the results of long-term studies carried out by the authors on the territory of 14 administrative formations of the West Siberian region.Research findings: Schematic is proposed for taxonomic division of territories based on the elements of the geographical complex of administrative entities of the Russian Federation. Differences between the calculated values of clay soil properties given in normative documents and experimental data, are shown on the example of the territory of the Omsk region.

Wire-based friction stir additive manufacturing towards isotropic high-strength-ductility Al-Mg alloys

ABSTRACT The formation of eutectic Al-Mg2Al3 phases along the grain boundaries makes it difficult to improve the mechanical properties of high-magnesium-content aluminum alloys. Here, wire-based friction stir additive manufacturing(W-FSAM) was proposed as a novel solid-state additive manufacturing technology. The shearing, transport, and thermo-plasticisation processes of the deposited materials were achieved by a rotational tool and a stationary barrel. The original Mg2Al3 phases were refined and dissolved into the matrix and formed supersaturated solid solution structures. The refined grains with a diameter of 1.27 ± 0.64 μm were achieved through the dynamic recrystallization process. The components achieved isotropic mechanical properties due to the homogeneous equiaxed fine-grain structure. The ultimate tensile strength reached 415 ± 11 MPa with an elongation of 31.0 ± 2.0%, superior to the commercial 5xxx products. The enhanced strain hardening capacity was achieved by the suppressed emission of dislocations from grain boundaries and the interaction between the supersaturated solid solute atoms and mobile dislocation.

Stone Staircase Design in Historical Buildings in Tomsk Late in 19th and Early 20th Centuries

The paper studies the stone staircase design in Russia and Tomsk on the example of the main building of the former Tomsk Imperial University built in 1878-1888, and the building 12 on Gogol Street built in 1908.The relevance of the article is conditioned by the necessity to consider historical staircases when carrying out repair and restoration works on the objects of cultural heritage and historical buildings for the maximum preservation of their authenticity.Purpose: To study the design of stone staircases late in the 19th and early 20th centuries in Russia and Tomsk. The study is based on the analysis of books and manuals on the construction art in 19–20th centuries, allowing to study the types and design of staircases characteristic to that period.Methodology/approach: The article collects and generalizes the material on typical structural solutions of stone staircases in the historical buildings of Tomsk. An integrated approach including the literature review contributes to the goal achievement.Practical implications: The obtained results can be used in repair and restoration of residential and public stone objects of historical buildings in Tomsk.Value: The identification of stone staircase design in the 19–20th centuries in residential and public buildings of the city of Tomsk.

A mechanized assembly for erecting soil-cement barriers to protect agricultural lands from low-active waste during flood

The object of this study is the process of constructing a waterproof underground barrier from local soil using loess loam and medium-sized sand as an example. The values of waterproofing of soil cements on different types of soil and the norms of net labor consumption corresponding to them were obtained. The research solves the task of protecting agricultural lands in the areas of geological burials of low-level radioactive waste. Configuration of a mechanized drilling mixing assembly for installing a waterproof barrier in the field has been proposed. Waterproofness of soil cement on clay and sandy soils was determined experimentally. The corresponding norms of the net consumption of time for manufacturing the barrier in these soils have been determined. Units of the mechanized assembly are repairable, utilize widely available materials, parts, and mechanisms. As a result of studies on the labor intensity of the installation of soil cement, a net labor rate was established, which varies from 35 to 52 min/m3 depending on the type of soil. The corresponding values of waterproofness, which ranged from W6 to W14, were determined, which substantiates the possibility of effective functioning of soil-cement underground barriers. Options for the structural solution for impenetrable barriers have been offered. The values of the obtained net time rates are explained by the high degree of mechanization of the technological process and the use of local materials. A distinctive feature of the results is the emphasis on the data collection on the time consumption of machines and mechanisms, the characteristics of local soils under production conditions, and the use of local materials. The assembly implies using affordable and repairable units that can be serviced right in the field. Given this, the manufacturability of the proposed process was defined, confirmed by time-keeping studies. The realm of practical application of the reported results are sites within flat areas with sandy or loess bases. Barrier solutions are designed exclusively for geological waste storage facilities under the conditions of a high level of groundwater and the presence of a waterproof layer at the base

The Investigation of Nonlinear Time-Fractional Models in Optical Fibers and the Impact Analysis of Fractional-Order Derivatives on Solitary Waves

In this article, we investigate a couple of nonlinear time-fractional evolution equations, namely the cubic-quintic-septic-nonic equation and the Davey–Stewartson (DS) equation, both of which have significant applications in complex physical phenomena such as fiber optical communication, optical signal processing, and nonlinear optics. Using a powerful technique named the extended generalized Kudryashov approach, we extract different rich structured soliton solutions to these models, including bell-shaped, cuspon, parabolic soliton, singular soliton, and squeezed bell-shaped soliton. We also study the impact of fractional-order derivatives on these solutions, providing new insights into the dynamics of nonlinear models. The results are compared with the existing literature, revealing novel and distinct solutions that offer a deeper understanding of these fractional models. The results show that the implemented approach is useful, reliable, and compatible for examining fractional nonlinear evolution equations in applied science and engineering.

Impact of Various High Intensity Earthquake Characteristics on the Inelastic Seismic Response of Irregular Medium-Rise Buildings

In the twenty-first century, the seismic design of buildings seems to have become a fully recognized topic. There are guidelines and standards which should be taken into account by designers in seismic areas. Designers using modern international guidelines have ascertained that the behavior of structures is not as expected. New challenges in the construction industry result in the construction of structures with new, unusual shapes. These are structures that do not meet the assumptions of safe construction in seismic areas. Contemporary buildings are also characterized by their irregular distribution of structural elements. Such solutions are not beneficial from the point of view of seismic engineering and can lead to reduced dynamic resistance and damage in such structures. In this paper, a five-storey, irregular-shaped reinforced concrete (RC) building model was subjected to different earthquakes with varying magnitudes, PGA (peak ground acceleration) and PGV (peak ground velocity) values, and durations of the intense shock phase. Once the model was verified using previous in situ measurements, the building model was subjected to five earthquakes. A numerical nonlinear analysis of the building was performed using a verified FEA (finite element analysis) model in the time domain through non-linear time history analysis with the Broyden–Fletcher–Goldfarb–Shanno (BFGS) method. The building’s dynamic properties were measured using various methods of excitation. The model was influenced, among others, by two far-field representative events caused by the last earthquake in Turkey, which resulted in strong ground motion. The analysis results identified the locations of structural damage and allowed for the assessment of the structure’s dynamic resistance. The results of the calculations prove that the duration of the intensive phase of extortion is one of the reasons for building damage in earthquake-prone areas. Building damage occurs with earthquakes that are characterized by an intensive phase of excitation with a long duration and high values of velocity in the earthquake components. The article highlights the inadequate dynamic resistance of the building, leading to excessive displacements and unfavorable structural solutions. Damage to buildings at this earthquake intensity caused damage to the load-bearing structure, which was not designed for such intensities. This paper is a research report with a specific case study of medium-rise irregular RC buildings.

“It's not that we Feel Incompetent, We Simply Lack the Institutional Solutions” Applying a Collective Capabilities Perspective to Voluntary Organisations in the Homelessness Field

ABSTRACT In today’s changing care and welfare landscape, voluntary organisations play an important role in providing care to homeless people. The limited literature on such initiatives is often sceptical about their effectiveness, although they do point to their positive contributions. In this paper, we use a Collective Capabilities lens to analyse the role, value, and limitations of volunteer initiatives addressing homelessness. We apply this framework to four case studies of volunteers-only initiatives providing care to homeless people in Brussels, Belgium. Data were collected through participant observation, interviews and document analysis. Our results highlight the trade-offs that voluntary organisations make between organisational capacities and agency. While formalisation and cooperation may contribute to an organisation's mission, these processes are sometimes avoided to preserve the unique contributions these organisations believe they make, such as providing care for people who fall between the cracks of the welfare state. Our results suggest that while voluntary organisations working with homeless people are aware of their limited capabilities regarding structural solutions, they do respond to unmet needs precisely because of their agency. However, there is a risk that fledgling organisations may take reckless and unsustainable actions.

On the solutions of the Lane-Emden model via non-dyadic wavelet scheme to unravel astrophysical phenomena

The research focuses on exploring the characteristics of the Lane Emden equation, which is a second-order ordinary differential equation that has its roots in astrophysics. To approximate this equation, a technique that employs non-dyadic Haar wavelets in conjunction with quasi-linearization is utilized. By utilizing non-dyadic wavelets, the ordinary differential equation can be simplified into a system of algebraic equations. Error estimates are provided to assess the accuracy of the produced data. A comparison between the existing solutions and the numerical results obtained using the suggested approach is performed to showcase its efficiency and advantages. The non-dyadic Haar wavelet approach is found to be a rich structure for numerous solutions that span a wide range of physical parameter.