Experimental Techniques Research Articles

Insulin attenuates LPS-induced cognitive impairment and ferroptosis through regulation of glucose metabolism in hippocampus.

Neuroinflammation is a recognized contributor to cognitive disorders like Alzheimer's disease, with ferroptosis emerging as a novel mechanism underlying cognitive dysfunction associated with neuroinflammation. Insulin, pivotal in the central nervous system, holds promise for cognitive function enhancement. This study aimed to establish a cognitive impairment model through intracerebroventricular injection of lipopolysaccharide (LPS) and explore the impact of intracerebroventricular insulin injection on cognitive function in mice. We employed diverse experimental techniques, including animal behavior testing, molecular assays, targeted metabolomics, nuclear medicine, and electron microscopy, to assess neurodegenerative changes, brain insulin resistance (IR), glucose uptake and metabolism, and ferroptosis. The model of cognitive impairment was induced via intracerebroventricular injection of LPS, followed by intracerebroventricular administration of insulin to evaluate its effects. Insulin treatment effectively mitigated LPS-induced cognitive decline and safeguarded against neuronal degeneration. Furthermore, insulin alleviated LPS-induced insulin resistance, enhanced glucose uptake in the hippocampus, and promoted the Pentose Phosphate Pathway (PPP) and nicotinamide adenine dinucleotide phosphate (NADPH) production. Additionally, insulin activated the glutathione (GSH)-glutathione peroxidase 4 (GPX4) pathway, reducing lipid peroxidation, and mitochondrial damage characteristic of LPS-induced ferroptosis in the hippocampus. Our findings underscore the therapeutic potential of insulin in alleviating LPS-induced cognitive impairment and ferroptosis by modulating glucose metabolism. This study offers a promising avenue for future interventions targeting cognitive decline.

Laser powder bed fusion of bio-inspired metamaterials for energy absorption applications: A review

A significant amount of research has been done in the last few decades to reduce the risk of injury for occupants and the structures that are subjected to impact loading. Metamaterials have been proven to be useful in energy-absorbing structures to improve a structure's crashworthiness performance by reducing the negative impacts during collision. The metal additive manufacturing industry, especially Laser Powder Bed Fusion (LPBF), has made it easier to produce complex metamaterials with remarkable mechanical characteristics like lightweight, high specific strength, and effective energy absorption. This review paper investigates the transformative potential of bio-inspired metamaterial designs, which are additively manufactured using LPBF machines, for use in protective energy-absorbing structures. First, biomimicry in engineering is briefly discussed. The review focuses on the energy absorption performance of different designs, like thin-walled structures and different bio-inspired metamaterials. It discusses the effects of base metal, process conditions, and manufacturing defects. Optimization methods to enhance the design and crashworthiness of these bio-inspired energy absorbers are investigated. Various characterization methodologies including experimental techniques and numerical simulations, are highlighted, with a particular emphasis on integrating manufacturing defects into simulations. Finally, possible applications and future trends in aerospace, automotive, construction, and medical applications are reviewed. Despite decades of research into energy absorbers, there remains a lack of a comprehensive review on the use of additively manufactured metamaterials as energy absorbers, particularly those inspired by nature. This review paper addresses this gap by examining recent studies in the field, assessing the effectiveness of various bio-inspired metamaterial designs, their crashworthiness, and the associated characterization methods under different loading scenarios.

A coupled thermo-mechanical model for investigating cracking and failure of composite interbedded rock

Composite interbedded rock is a special geological phenomenon that occurs when layers of rock (beds) of a given lithology lie between or alternate with other layers of a different lithology. The thermal and mechanical properties of the composite interbedded rocks exhibit strong anisotropy. Studying the thermomechanical coupling properties of natural composite interbedded rocks using existing experimental techniques is challenging. A coupled thermo-mechanical composite interbedded rock model was developed based on Fourier's heat-conduction law and Newton's second law. The thermodynamic responses and biaxial mechanical properties of composite interbedded rocks with different interlayer angles under the coupling of initial stress and thermal loading were studied for the first time. The results indicate that the thermal stresses within the granite interlayers are higher than those within the sandstone interlayers. Throughout the thermal loading process, thermal cracking occurred primarily within the (stiffer) granite interlayers. The number of thermal cracks generated during the cooling process far exceeds that during heating; at 400 °C, the number of thermal cracks during cooling is more than 35 times that during heating. When the interlayer dip angle approaches 90° and is aligned with the major principal stress direction, the phenomenon of the “double peaks” and layered failure becomes more pronounced. Within the range of variables considered, the relative impact of the three variables on peak stress in composite interbedded rock is as follows, from greatest to least: interlayer angle, thermal shock temperature, and model size. The results and developed modeling methods will contribute to the management and optimization of future engineering geology projects.

An experimental and numerical framework to assess the temperature distribution in complex He II-cooled magnet geometries

In the context of the High Luminosity upgrade of the Large Hadron Collider at CERN, a framework implementing experimental techniques and numerical analysis has been developed to systematically assess the temperature distribution in complex He II-cooled composite magnet geometries. The experiments are designed to measure the heat transfer coefficients in the magnet coil layers using coil samples in a stagnant superfluid helium bath. A numerical tool-kit has been developed to facilitate intensive parametric studies, in addition to estimation of helium content via a phenomenological model. The workflow of the tool-kit is built to handle complex geometries composed of different materials each with their temperature-dependent properties, at low computational cost. This framework has been validated with experimental data obtained from laboratory-scale experiments on impregnated coil samples, reported and discussed here. Three use cases for the developed numerical tool, with increasing levels of complexity, are presented and its results discussed.

The Influence of Sleep Quality on Learning Concentration in Students

In the learning process, a person needs concentration to be able to understand and interact with his environment. One of the things needed in order to concentrate on studying is to maintain good quality sleep. Therefore, this experimental study aims to measure and identify whether there is an effect of sleep quality on learning concentration in Psychology students of UIN Raden Fatah Palembang. This study uses a quantitative experimental technique with a Static Group Comparison design. The population of this study was the active students of the Faculty of Psychology, UIN Raden Fatah Palembang, amounting to 882 people. Determined 30 respondents as a sample selected by purposive sampling technique. Respondents were divided into 2 groups. The first group consisted of 15 respondents with the classification of staying up late, and group 2 consisting of 15 respondents with the classification of regular normal sleep. The data collection technique was through a questionnaire sheet and then analyzed using the chi-squere test.

Characterization of rigid open-cell foams using direct ultrasonic simulation.

An ultrasonic simulation technique based on the direct fluid model is proposed as an alternative to the analogous experimental technique to determine the tortuosity and characteristic lengths for high pore-density foams. It is beneficial as it reduces cost and almost eliminates the signal-to-noise issues encountered in the experiment. The proposed method is demonstrated for periodic microlattices with three different unit-cell configurations, 75%-90% porosity, and a pore size of about 200 microns. The technique is also applicable to high-resolution computed tomography (CT) scans of open-cell foams with a priori unknown microporous structure. An acoustic simulation software, ACTRAN® (Hexagon AB, Stockholm, Sweden), is used to model and perform analysis of the ultrasonic pulse propagation through the foam. Based on through-transmission by foam saturated with two different mediums, the tortuosity, and characteristic lengths are estimated from the high-frequency asymptotic behavior of the square of the propagation index (Nr2) versus the inverse square root of frequency (1/f). The predicted parameters are validated by comparing them with those determined by solving the electric conduction boundary value problem for the same configuration. Further, detailed parametric sensitivity analysis reveals the sensitivity of the Johnson-Champoux-Allard parameters to errors in Nr2 and so the effect of these errors on the acoustic absorption behavior of the rigid porous sample.

Multiple micro-cavity vibro-polaritons formation with different vibrational bands of the methylene group

We present an experimental technique to accurately predict the formation of vibro-polaritons from a molecular polymeric film embedded in a resonant mid-infrared cavity. Using simple Fourier-transform reflectance measurement, we extract the complex dielectric function of a polyethylene film using Kramers-Kronig relations. The fitted dielectric function can be plugged into a numerical code to predict the strength and dispersion of the strong light-matter coupling regime between the quantized electromagnetic modes of a microcavity and the vibrational bands of the molecules. As a demonstration, we experimentally resolve the simultaneous formation of multiple vibro-polariton modes issued from the strong coupling of some vibrational bands of the methylene group (CH2) in a 2.5-μm-thick polyethylene film embedded in a microcavity. We measure a Rabi splitting of 6.3 THz for the stretching doublet around 87.5 THz and a Rabi splitting of 1.1 THz for the scissoring doublet around 43.7 THz, in excellent agreement with numerical predictions.

Rheological behaviors of Na-montmorillonite considering particle interactions: A molecular dynamics study

Understanding the rheology of bentonite suspensions is crucial for ensuring the safety of engineering practices. However, the rheological mechanisms of bentonite remain unclear due to the limitations of conventional experimental techniques, particularly in assessing the microscopic interactions between clay particles and their impact on rheological properties. In this paper, the rheological behaviors of Na-montmorillonite were studied with a focus on interparticle interactions. Both equilibrium molecular dynamics (MD) and non-equilibrium MD simulations were conducted to understand the physical properties of Na-montmorillonite under zero shear and various shear rates, respectively. The interaction between two parallel clay particles was determined in simulations, indicating that the classical Darjaguin-Landau-Verwey-Overbeek (DLVO) theory underestimates the interactions for a small separation distance. Na-montmorillonite exhibits a typical shear thinning behavior under shearing. However, as water content increases, it begins to behave more like liquid water. The yield stress of montmorillonite, as determined by the Bingham model, was found to be linearly related to the interaction pressures between clay particles. Besides MD simulations, the microstructure of clay suspension was further quantified using the separation distance and incline angle between non-parallel clay particles. Based on MD results and the quantified clay structure, a model was developed to estimate the yield stress of montmorillonite considering various influence factors, including electrolyte concentration, temperature, and solid fraction. Finally, from a comparison with calculated and experimental data, the results confirm the good performance of the proposed model. These findings provide significant insights for understanding the rheological soil behaviors and evaluating the yield stress of bentonite suspensions.

Cross-correlation-based convolutional neural network with velocity regularization for high-resolution velocimetry of particle images

Particle image velocimetry (PIV) stands as a pivotal experimental technique in fluid dynamics, enabling the visualization and analysis of fluid flows. Traditional methods for extracting velocity fields from particle images often rely on window-cross correlation PIV or, more recently, optical flow techniques rooted in intensity conservation principles. However, the former approach suffers from low resolution, whereas the latter is hampered by computational inefficiency and a high susceptibility to noise. Recent studies have demonstrated the effectiveness of convolutional neural networks (CNNs) in processing particle images to obtain high-resolution and high-accuracy velocity fields, though traditional CNN architectures are still not satisfying in accuracy. The present study introduces an enhanced network, En-FlowNetC, based on the cross correlation-based CNN FlowNetC, specifically designed to process PIV particle images and achieve high-accuracy, high-resolution velocity fields. It incorporates a velocity regularization and is trained and validated on canonical datasets. The results indicate that En-FlowNetC surpasses traditional CNN networks in accuracy and markedly outperforms the classic Horn–Schunck optical flow method in both complex and simple flow scenarios. Furthermore, this study confirms the beneficial impact of velocity regularization, when judiciously applied, on network accuracy. The proposed modifications compared to the original FlowNetC are also examined in the ablation experiments. Overall, En-FlowNetC provides an effective deep-learning solution for PIV analysis, paving the way for future endeavors aimed at achieving highly accurate and resolved velocimetry.

Methods of physical rehabilitation of schoolchildren aged 15-17 with cervical osteochondrosis

Background. The problem of rehabilitation of children with cervical osteochondrosis can be solved by creating a special technique and performing additional exercises at home. The objective of the study is rehabilitation of high school students with osteochondrosis of the cervical spine. Methods: boys and girls aged 15-17 who were diagnosed with osteochondrosis of the cervical spine took part in the research. A total of 38 schoolchildren took part in the study. The study was conducted from February 28 to May 26, 2023 on the basis of several secondary schools in the city of Kirov. All students in both groups studied according to the standard program 3 times a week. Children from experimental group B additionally performed sets of physical exercises from the experimental methodology. The study used tests that evaluate the static strength of the abdominal and back muscles, the flexibility and endurance of the cervical spine and the speed and strength abilities of the arm muscles. When analyzing the results, their statistical processing was carried out using the arithmetic mean, square deviation, error and difference. Confidence at p<0.05. Results: According to the results of the research, it was found that children from the control group were able to slightly improve the studied indicators to 10.6%, the increase in indicators from the beginning to the end of the study on all tests turned out to be unreliable (p>0.05). In the experimental group, at the end of the study, the indicators for all tests improved from 23.5% to 66.7% (p<0.05). Thus, the experimental technique is more effective in the treatment of cervical osteochondrosis than the generally accepted technique.Conclusions: Systematic physical education with the use of special physical exercises aimed at eliminating problems in the cervical spine give a significant effect in the rehabilitation of cervical osteochondrosis. The indicators of the static strength of the abdominal and back muscles will improve, the flexibility and endurance of the cervical spine will also increase, and the speed and strength capabilities of the arm muscles will increase. Keywords: School children's health, Lifestyle, Rehabilitation, Joint mobility, Physical therapy.

MULTI-THEORETICAL EXPLICATION OF EXPERIMENTAL TYPOGRAPHY: THE CONTEXT OF 21ST CENTURY LITERARY TEXTS

This study is a multi-theoretical explication of selected 21st-century literary texts with a focus on determining how literary pieces with experimental typography can be analyzed which places emphasis on a literary primer that can be produced from the textual analysis, interpretation, and explication of the texts analyzed. This research study examines the significance of experimental typography in selected literary texts, specifically focusing on Tahereh Mafi’s Shatter Me Novel, Austin Kleon’s Newspaper Blackout, and shape poetry. The findings revealed that authors employ various types of experimental typography to convey additional layers of meaning in their works. The analysis of Tahereh Mafi's novel "Shatter Me" identifies the use of strikethrough, the management of space, and the unconventional use of mechanics as experimental typography techniques. In blackout poetry, the interaction between visual and textual elements through the use of semiotics plays a vital role in conveying the intended message. Shape poetry, on the other hand, integrates language, design, and visual representation to create a cohesive composition, offering a unique and visually engaging reading experience. Based on the findings, it is concluded that writers utilize multiple modalities manifested in experimental typography, embedding symbolism in literature. Readers must recognize these modalities and analyze their impact on literary elements to develop accurate interpretations. The study recommends further exploration of 21st-century literary analysis, emphasizing works incorporating experimental typography and innovative forms of literary expression. It suggests making a primer on experimental typography available to literature students to enhance their understanding of typography's expressive potential. Additionally, the study proposes exploring other modalities employed by modern writers and testing the primer's usability in schools to optimize its impact on students' learning experiences and curriculum enhancement. This research contributes to the understanding and appreciation of experimental typography in contemporary literature.

Contact Electrification as an Emerging Strategy for Controlling the Performance of Metal Nanoparticle Catalysts

Contact electrification (CE) is an emerging strategy for controlling the performance of metal nanoparticle (NP) catalysts. The underlying physical principle of this control is the sensitivity of the Fermi level to metal‐metal contacts. This change in electronic structure has a direct impact on surface properties and chemical reactivity. The concept article briefly introduces the basic theory of CE and its relationship to catalytic performance. We then highlight selected recent examples of advances in the preparation of hybrid metal NP assemblies, experimental techniques for characterizing CE, and finally applications of CE for altering catalytic performance.

Molecular Dynamic Simulations for Biopolymers with Biomedical Applications.

Computational modeling (CM) is a versatile scientific methodology used to examine the properties and behavior of complex systems, such as polymeric materials for biomedical bioengineering. CM has emerged as a primary tool for predicting, setting up, and interpreting experimental results. Integrating in silico and in vitro experiments accelerates scientific advancements, yielding quicker results at a reduced cost. While CM is a mature discipline, its use in biomedical engineering for biopolymer materials has only recently gained prominence. In biopolymer biomedical engineering, CM focuses on three key research areas: (A) Computer-aided design (CAD/CAM) utilizes specialized software to design and model biopolymers for various biomedical applications. This technology allows researchers to create precise three-dimensional models of biopolymers, taking into account their chemical, structural, and functional properties. These models can be used to enhance the structure of biopolymers and improve their effectiveness in specific medical applications. (B) Finite element analysis, a computational technique used to analyze and solve problems in engineering and physics. This approach divides the physical domain into small finite elements with simple geometric shapes. This computational technique enables the study and understanding of the mechanical and structural behavior of biopolymers in biomedical environments. (C) Molecular dynamics (MD) simulations involve using advanced computational techniques to study the behavior of biopolymers at the molecular and atomic levels. These simulations are fundamental for better understanding biological processes at the molecular level. Studying the wide-ranging uses of MD simulations in biopolymers involves examining the structural, functional, and evolutionary aspects of biomolecular systems over time. MD simulations solve Newton's equations of motion for all-atom systems, producing spatial trajectories for each atom. This provides valuable insights into properties such as water absorption on biopolymer surfaces and interactions with solid surfaces, which are crucial for assessing biomaterials. This review provides a comprehensive overview of the various applications of MD simulations in biopolymers. Additionally, it highlights the flexibility, robustness, and synergistic relationship between in silico and experimental techniques.

Numerical and experimental investigations of swirl-stabilized partially premixed flames using natural gas-hydrogen-air mixtures

This study uses experimental and numerical techniques to examine natural gas and hydrogen mixtures as fuel with a partially premixed swirl-stabilized burner. Variations in the fuel mixture composition were investigated throughout the course of the study. In the experiments, hydrogen was gradually added to the fuel combination, initially made only of natural gas. Chemiluminescence imaging was used to examine how the addition of hydrogen affected the stability and overall structure of the flame. Throughout the experiments, the overall volumetric fuel flow rate remained constant. The change to the flame stabilization mode from a detached flame to a burner attached flame only happened once a certain volumetric hydrogen ratio (H2VOL%) in the fuel was attained. Numerical simulations also evaluated how the lifted flame dimensions and stabilization method changed. The simulations are performed using a commercial compressible, finite volume Large Eddy Simulation software and include the Thickened Flame Model (TFM) for turbulence-chemistry interactions, the Flamelet Generated Manifold (FGM) combustion model, and the Large Eddy Simulation (LES) turbulence model. Experimental and numerical results show that the flame lowers and becomes more compact as the H2VOL% increases. Additionally, experimental and numerical data showed that the flame stabilization mode changes for H2VOL% approaching the value of 70%.

An experimental and theoretical approach of a novel phosphoramide containing naphthoquinone with potential cytotoxic and apoptosis-inducing ability

In an attempt to synthesize a new potent cytotoxic and apoptosis-inducing agent against SK-BR-3 breast cancer cells, a new phosphoramide containing naphthoquinone (Diphenyl (1,4-dioxo-1,4-dihydronaphthalen-2-yl)phosphoramidate; A) was synthesized and characterized using some experimental techniques such as IR, 1H NMR, 13C NMR, 31P NMR, and Mass spectroscopies. The obtained data were compared with theoretical FT-IR, 1H NMR, 13C NMR and 31P NMR calculated with density functional theory (DFT), which confirmed that there is a good correlation between them. The cytotoxic activity of A against cancer cell line (SK-BR-3) and normal cell line (MCF10A) were evaluated through an MTT assay. The results showed a dose- and time-dependent anti-cancer activity with IC50 values of 10.3 µM (24 h) and 8.1 µM (48 h). According to the flow cytometry results, A showed great apoptosis-inducing ability at different concentrations (5 µM) (41.88%), 20 µM (72.6%), and 30 µM (79.1%). Moreover, the cells inhibited through the late apoptosis pathway increased as a function of the concentration of A. In order to know the structure-activity relationship (SAR) of the synthesized compound and cyclophosphamide (Cpm), the values of HOMO and LUMO energies, hardness, softness, and electrophilicity index were investigated computationally by DFT-D correction in Material Studio 2017. Additionally, molecular docking simulation was used to compute the interactions between (A or Cpm) and transcription factor STAT3B/DNA complex (PDB ID: 1bg1), indicating A has a considerable anti-cancer potential with docking energy of -101.964 kcal.mol-1 compared with -64.281 kcal.mol-1 for Cpm.

Investigation of The Effect of Molding Material Difference on Design in GGG70 Ductile Cast Iron Production

The casting process involves filling a prepared mould cavity with molten metal, which takes the shape of the container. While the liquid metal takes the shape of the container it is in, the method is attractive, while the volumetric changes during the liquid-solid transformation reveal the importance of moulding design for the manufacture of solid parts. Especially in cast irons, moulds with the same design may produce different results depending on the changing casting and foundry conditions because the volumetric change that occurs during the solidification of ductile cast irons is affected by many parameters and develops differently than in steel and aluminium castings. This study used model wet and resin molding materials to create single and double-riser moulding and castings with different section thicknesses. The importance of the type of mold material used in castings and the number of feeders for the robust production of the cast part was evaluated using experimental and modeling techniques. When the results were examined, it was seen that the shrinkage risk was lower with resin mould than with green sand moulding. In addition, depending on the riser connection point, the importance of the riser neck has emerged.

System Identification Based on Experimental Technique Using Stability Boundary Locus Method for Linear Fractional Order Systems

System Identification Based on Experimental Technique Using Stability Boundary Locus Method for Linear Fractional Order Systems

Multiple Fano Resonances Enabled by the Interference between an Out‐of‐Plane Plasmon Mode and Fabry–Pérot Cavity Modes

AbstractMultiple Fano resonances (mFRs) are arising as a promising optical platform to achieve precise sensing and detection. However, experimentally achieving mFRs by simple structures has remained challenging, which impedes the widespread applications of mFRs. Herein a simple structure composed of a single colloidal metal nanoparticle and a transition metal dichalcogenide flake to simultaneously achieve up to 8 FRs in experiments is demonstrated. Combining theoretical and experimental techniques, that an out‐of‐plane plasmon mode of the metal nanoparticle interferes with the Fabry–Pérot cavity modes from the WS2 flake to form mFRs in the visible region is proved. The simplicity and generality of the method further allow us to systematically study the tunability of the mFRs, in terms of the peak/dip positions and the number of FRs, by changing the structural parameters, which include the thickness of the WS2 flake, size and shape of the plasmonic nanoparticle. In addition, the quality of the mFRs is proved to be adjustable by tuning the reflectivity of the substrate in the system. The highest quality factor and spectral contrast of the achieved resonances are up to ≈180 and ≈0.95, respectively. The simple structure and high‐quality optical modes will prosper applications in precise sensing and light modulation.

Secondary neutrons in proton and light ion beam therapy: a review of current status, needs and potential solutions

The advantages of proton and light ion beam therapy compared to conventional photon radiation therapy are well-known, mainly thanks to the characteristic depth dose distribution of ions and their radio-biological effectiveness. Nevertheless, the use of ions implies different nuclear reactions that generate secondary particles, with neutrons among them. These secondary neutrons can travel far away from the treatment volume, their measurement is a challenging complex task, and their biological effects are particularly high for neutrons with energies in the MeV range. In this review, a comprehensive description of secondary neutron dosimetry in proton and light ion beam therapy is given. Many studies have been conducted on the quantification of the secondary neutron dose, most of them have been performed for proton beams, whereas for other ions like carbon, the available information is scarce. The main measurement campaigns are summarised, focusing on the type of detectors used. In line with the detectors’ advantages and limitations, measurements performed inside and outside anthropomorphic phantoms are considered. The role of Monte Carlo radiation transport simulations is discussed since many experimental detection techniques need additional simulations to provide dose estimates. A focus on the current challenges for the measurements of neutrons with energies above 20 MeV is given, as this is one of the main components of secondary neutrons produced by therapeutic ion beams. Finally, the potential clinical relevance of the available and needed secondary neutron dose data is discussed, in terms of its impact on the treatment of patients. For this, the relative biological effectiveness of neutrons and the potential risk of cancer induction re-incidence or secondary cancer due to secondary neutron doses play a key role.

Limitations of hydrogen detection after 150 years of research on hydrogen embrittlement

Hydrogen’s significance in contemporary society lies in its remarkable energy density, yet its integration into the worldwide energy grid presents a substantial challenge. Exposing materials to hydrogen environments leads to degradation of mechanical properties, damage, and failure. While the current approach for assessing hydrogen’s impact on materials involves multiscale modeling and mechanical testing, there exists a significant deficiency in detecting the intricate interactions between hydrogen and materials at the nano‐atomic scales and under in situ conditions. This perspective review highlights the experimental endeavors aimed at bridging this gap, pointing towards the imminent need for new experimental techniques that can detect and map hydrogen in materials’ microstructures and their site‐specific dependencies.This article is protected by copyright. All rights reserved.