Changes In Tension Research Articles

Some physicochemical properties of ethyl oleate mixtures with ethanol and n-hexane

Due to the wide use of ethyl oleate (EO) in agriculture, medicine and automotive fuels, measurements of the surface tension, density, viscosity and contact angle of a mixture of ethyl oleate with ethanol (ET) and/or n-hexane (HEX) were made. The contact angle was measured on polytetrafluoroethylene (PTFE), poly(methyl methacrylate) (PMMA), glass and steel. The measurement results for the mixtures of EO + ET and EO + HEX were analyzed based on the properties of individual components of the mixtures. When considering the changes in the surface tension and contact angle on PTFE for the EO + ET and EO + HEX mixtures as a function of the mixture composition there were taken into account, not only the values of the total surface tension of the mixture components, but also the components and parameters of this tension. Based on the surface tension components and parameters of EO, ET, HEX, PTFE, PMMA, glass and steel, it was possible to predict changes in the surface tension of tested mixtures and the contact angle as a function of the mixture composition.

INVESTIGATION OF SURFACE PROPERTIES OF MODIFIED BITUMEN COMPOSITIONS

One of the main reasons for premature destruction of road surfaces is the poor quality of road bitumen. An effective way to improve the quality of a bitumen binder is to modify it with polymer or surface-active additives. The goal is to determine the effect of the concentration of modifiers on surface tension in binary "bitumen-surfactant", "bitumen-polymer" and triple "bitumen-surfactant-polymer" systems. The methodology of the work included measuring the surface tension of modified bitumen systems depending on the quantitative content of additives in bitumen. Results and discussion: As follows from the analysis of the data obtained, in bitumen systems with a limited concentration of polymer AG-4I (C≤1 g/dm3), the effect of reducing surface energy at the interface with air is achieved by concentrating surfactants in the surface layer, which are part of the structure of the bitumen itself. The extreme nature of the change in surface tension was also recorded in AC-2 bitumen compositions. Conclusion: In the "bitumen-AG-4I-AS-2" triple systems, the change in the specific surface energy at the "liquid-gas" interface is not an additive value, taking into account the separate contribution of AG-4I and AS-2. The concentration threshold of additives to achieve a minimum surface tension varies in comparison with binary compositions. With the combined administration of AG-4I (C=1g/dm3) and AC-2 (C=1g/dm3), the surface tension decreased by 9.30 mN/m compared with unmodified bitumen.

Characteristics and Mechanisms of CO2 Flooding with Varying Degrees of Miscibility in Reservoirs Composed of Low-Permeability Conglomerate Formations

The reservoir type of the MH oil field in the Junggar Basin is a typical low-permeability conglomerate reservoir. The MH oilfield was developed by water injection in the early stage. Nowadays, the reservoir damage is serious, and water injection is difficult. There is an urgent need to carry out conversion injection flooding research to improve oil recovery. The use of CO2 oil-flooding technology can effectively supplement formation energy, reduce greenhouse gas emissions, and improve economic benefits. In order to clarify the feasibility of CO2 flooding to improve oil recovery in conglomerate reservoirs with low permeability, strong water sensitivity, and severe heterogeneity, this paper researched the impact of CO2 miscibility on production characteristics and mechanisms through multi-scale experiments. The aim was to determine the feasibility of using CO2 flooding to enhance oil recovery. This study initially elucidated the oil displacement characteristics of varying degrees of miscibility in different dimensions using slim tube experiments and long core experiments. Subsequently, mechanistic research was conducted, focusing on the produced oil components, changes in interfacial tension, and conditions for pore mobilization. The results indicate that the minimum miscibility pressure (MMP) of the block is 24 MPa. Under the slim tube scale, the increase in the degree of miscibility can effectively delay the gas breakthrough time; under the core scale, once the pressure reaches the near mixing phase, the drive state can transition from a non-mixed “closed-seal” to a “mixed-phase” state. Compared to the immiscible phase, the near-miscible and completely miscible phase can improve the final recovery efficiency by 9.27% and 18.72%. The component differences in the displacement products are mainly concentrated in the high-yield stage and gas breakthrough stage. During the high-yield stage, an increase in miscibility leads to a higher proportion of heavy components in the produced material. Conversely, in the gas breakthrough stage, extraction increases as the level of mixing increases, demonstrating the distinct extracting characteristics of different degrees of mixed phases. The core experiences significant variations in oil saturation mostly during the pre-gas stage. CO2 miscible flooding can effectively utilize crude oil in tiny and medium-sized pores during the middle stage of flooding, hence reducing the minimum threshold for pore utilization to 0.3 μm.

The role of [formula omitted] on controlling the pure vaterite transformations

Vaterite calcium carbonate (CaCO3) possesses unique advantages compared to calcite; however, some critical issues need to be addressed, such as vaterite stability. Numerous studies have indicated that NH4+ can promote vaterite formation and prevent its transformation. However, as vaterite is an instantaneous microscopic process that is easy to transform, directly revealing the role of NH4+ in stabilizing vaterite remains challenging in experiments. This research aims to reveal the role of NH4+ in stabilizing vaterite and retarding phase transformations. Vaterite stabilization was investigated at different NH4+ concentrations and characterized by XRD and SEM. The reaction system’s pH, electrical conductivity, and surface tension changes were analyzed in the presence of NH4+. Computational and experimental studies were utilized to determine the role of NH4+ in the stabilization of vaterite. Results revealed that NH4+ can significantly increase the existence time of vaterite in the water solution. The density functional theory (DFT) indicated that the adsorption energy of NH4+ and vaterite (110), (112), and (114) is obviously higher than that of H2O molecules. The molecular dynamics (MD) simulation research shows that NH4+ can replace water molecules on the crystalline surface of vaterite and mainly interact with carbonate ions on the surface of vaterite. The mechanism analysis shows that the inhibitory effect of NH4+ on the phase transformation of vaterite is primarily caused by preventing the dissolution process. This study systematically explains the role of NH4+ in the stability of vaterite and further reveals that NH4+ can not only promote the formation of vaterite but also play a decisive role in inhibiting its phase transition.

Experimental investigation of mechanical and physical properties of glass fiber reinforced concretes produced with different magnetized waters

Magnetized water may act as a thickener in cementitious mixtures due to its slippery effect. Therefore, it can be beneficial for the mixture to settle easily and to improve its strength. This study investigated the effects of magnetized water passing through pipes with magnetic field intensity (MFI) 8 and 10 on glass fiber reinforced concrete (GFRC). Three different mixtures, the GFRC mixture produced with regular tap water, were obtained, and the properties of the produced GFRC samples, such as 7, 14, and 28 days H-Leeb hardness, density, Ultrasonic pulse velocity (UPV), flexural strength, compressive strength, and fracture mechanics were investigated. In addition, SEM, EDS, FTIR, and TGA analyses were carried out to investigate the change in surface tension in the internal structures of GFRCs produced with magnetized water. Overall, the results were promising. Results showed a proportional H-Leep hardness increase with curing time and density variations. Magnetized water reduced air voids, enhancing sound transmission speeds. Flexural and compressive strength improved with magnetic water. The study suggests significant contributions to energy savings and reduced production costs, highlighting the efficient use of energy resources.

Interfacial Behavior of Biodegradable Poly(lactic-co-glycolic acid)-Pluronic F127 Nanoparticles and Its Impact on Pickering Emulsion Stability.

Biodegradable nanoparticle-based emulsions exhibit immense potential in various applications, particularly in the pharmaceutical, cosmetic, and food industries. This study delves into the intricate interfacial behavior of Pluronic F127 modified poly(lactic-co-glycolic acid) (PLGA-F127) nanoparticles, a crucial determinant of their ability to stabilize Pickering emulsions. Employing a combination of Langmuir balance, surface tension, and diffusion coefficient measurements, we investigate the interfacial dynamics of PLGA-F127 nanoparticles under varying temperature and ionic strength conditions. Theoretical calculations are employed to elucidate the underlying mechanisms governing these phenomena. Our findings reveal a profound influence of temperature-dependent Pluronic layer behavior and electrostatic and steric interactions on the interfacial dynamics. Nonlinear changes in surface tension are observed, reflecting the interplay of these factors. Particle aggregation is found to be prevalent at elevated temperatures and ionic strengths, compromising the stability and emulsification efficiency of the formed emulsions. This work provides insights into the rational design of stable and efficient biodegradable nanoparticle-based Pickering emulsions, broadening their potential applications in various fields.

The anisotropic and region-dependent mechanical response of wrap-around tendons under tensile, compressive and combined multiaxial loads

The present work reports on the multiaxial region and orientation-dependent mechanical properties of two porcine wrap-around tendons under tensile, compressive and combined loads based on an extensive study with n=175 samples. The results provide a detailed dataset of the anisotropic tensile and compressive longitudinal properties and document a pronounced tension-compression asymmetry. Motivated by the physiological loading conditions of these tendons, which include transversal compression at bony abutments in addition to longitudinal tension, we systematically investigated the change in axial tension when the tendon is compressed transversally along one or both perpendicular directions. The results reveal that the transversal compression can increase axial tension (proximal-distal direction) in both cases to orders of 30%, yet by a larger amount in the first case (transversal compression in anterior-posterior direction), which seems to be more relevant for wrap-around tendons in-vivo. These quantitative measurements are in line with earlier findings on auxetic properties of tendon tissue, but show for the first time the influence of this property on the stress response of the tendon, and may thus reveal an important functional principle within these essential elements of force transmission in the body. Statement of significanceThe work reports for the first time on multiaxial region and orientation-dependent mechanical properties of wrap-around tendons under various loads. The results indicate that differences in the mechanical properties exist between zones that are predominantly in a uniaxial tensile state and those that experience complex load states. The observed counterintuitive increase of the axial tension upon lateral compression points at auxetic properties of the tendon tissue which may be pivotal for the function of the tendon as an element of the musculoskeletal system. It suggests that the tendon’s performance in transmitting forces is not diminished but enhanced when the action line is deflected by a bony pulley around which the tendon wraps, representing an important functional principle of tendon tissue.

Impact of solvent temperature on graphite shear exfoliation efficiency

Liquid phase exfoliation (LPE) of graphite is a promising pathway for graphene flakes (GF) due to its scalability and cost-effectiveness. However, the method has significant limits at the industrial scale, such as low yield of GF and long processing times. In this study, we investigate the effect of organic solvents such as N-methyl-2-pyrrolidone (NMP) and methyl-5-(dimethylamino)-2-methyl-5-oxopentanoate (PolarClean) temperature on shear-induced exfoliation. The GF concentration was successfully obtained 0.62 mg/ml in NMP and 0.68 mg/ml in PolarClean within just 2 h at 263 K, without surfactants or any additional additives. These results revealed the improved exfoliation efficiency due to changes in solvent polarity, surface tension, and dispersion stability with increased viscosity. In addition, we investigate the optimization conditions required for liter-scale shear-induced exfoliation of graphite in PolarClean. As-prepared GF has significant potential as an effective nanofiller for enhancing the mechanical strength of commercial polymers. This study not only advances the understanding of the LPE mechanisms but also paves the way for the industrial application of this method in the green synthesis of graphene-based nanocomposites.

Shape of the membrane neck around a hole during plasma membrane repair

Plasma membrane damage and rupture occurs frequently in cells, and holes must be sealed rapidly to ensure homeostasis and cell survival. The membrane repair machinery is known to involve recruitment of curvature-inducing annexin proteins, but the connection between membrane remodeling and hole closure is poorly described. The induction of curvature by repair proteins leads to the possible formation of a membrane neck around the hole as a key intermediate structure before sealing. We formulate a theoretical model of equilibrium neck shapes to examine the potential connection to a repair mechanism. Using variational calculus, the shape equations for the membrane near a hole are formulated and solved numerically. The system is described under a condition of fixed area, and a shooting approach is applied to fulfill the boundary conditions at the free membrane edge. A state diagram of neck shapes is produced describing the variation in neck morphology with respect to the membrane area. Two distinct types of necks are predicted, one with conformations curved beyond π existing at positive excess area, whereas flat neck conformations (curved below π) have negative excess area. The results indicate that in cells, the supply of additional membrane area and a change in edge tension is linked to the formation of narrow and curved necks. Such necks may be susceptible to passive or actively induced membrane fission as a possible mechanism for hole sealing during membrane repair in cells.

ВИКОРИСТАННЯ АЛГОРИТМУ ДЕЙКСТРИ ПРИ КОМП'ЮТЕРНОМУ ПОШУКУ ОПТИМАЛЬНОГО ШЛЯХУ НЕОРІЄНТОВАНОГО ГРАФА З УРАХУВАННЯМ ВПЛИВУ РАДІАЛЬНОГО ОХОПЛЕННЯ НА ВАГОВІ ФУНКЦІЇ РЕБР

Taking into account the influence of radial coverage, the weight functions of the edges of an undirected graph during the computer search for the optimal path are determined. Algorithms and computer programs were used to find the optimal path of the graph using the Dijkstra algorithm, which made it possible to determine the tension and changes in the relative tension in the filling zones of knitted and textile machines, taking into account the specifics of the design of the thread feeding system. This leads to a decrease in thread breakage. The development of mathematical models for determining the reduced coefficient of friction during the interaction of the thread with the ring and tubular thread guides of knitting machines allows the use of algorithms and computer programs to find the optimal path of the graph, using Dijkstra's algorithm, in which the tension of the thread at the exit point will be minimal. This makes it possible to determine the tension and change of relative tension in the filling zones of knitted and textile machines, taking into account the specifics of the design of the thread feeding system, taking into account the effect of radial coverage. Searching for the optimal path of the graph allows you to reduce thread breakage and optimize thread tension in the working area of ​​the initial product formation. Determining the weight functions of edges, taking into account the influence of radial coverage, unoriented graph during the computer search for the optimal path is an important component of the optimization of thread tension in the working zone of the formation of the output product. Tension optimization is carried out on the basis of its minimization, which allows to reduce the probability of a break in the working area. Optimization of the geometric parameters of the thread feeding system on the technological equipment, namely the construction of such a broken form of the thread, in which the total angle of coverage of the constructive structural elements of the technological equipment in the form of guides of a cylindrical shape and in the form of a torus, elements of tensioning devices, devices for monitoring breakage will have a minimum value. This will reduce the amount of friction force between the thread and the guide surfaces and obtain minimum tension in the working area. Taking into account the large number of structural elements of the thread feeding system on technological machines, their location in the plane and space, there is a need to use modern information technologies.

馬韓·百濟·韓濊 권역의 인구변동

This study aims to investigate population dynamics in the Mahan, Baekje, and Ye regions. Settlement sites excavated in the Seoul-Gyeonggi, Yeongseo, Hoseo, and Honam regions, along with associated radiocarbon dates (2000-1300 BP), were compiled to assess their temporal and spatial distribution. Following adjustments to ensure the representativeness of the radiocarbon dates, trends in population growth and decline over time were analyzed using summed probability distributions of radiocarbon dates. Overall, a gradual increase in the density of radiocarbon dates was observed, peaking around 1750-1550 calBP before declining. This decline was attributed, to some extent, to changes in residential patterns and significant sampling biases. Regional analyses revealed variations in the timing and magnitude of population changes, with an earlier decline observed in the Yeongseo region around 1700 calBP compared to other regions, while the Hoseo and Honam regions experienced significant increases from around 1750 calBP before declining after 1550 calBP. Spatial distributions examined through kernel density analysis corresponded to these findings. While interpreting these changes based solely on the analysis presented herein may be insufficient, considering previous discussions, it is suggested that changes in trade networks and military tensions may have been important factors contributing to the early population decline in the Yeongseo region and northern Gyeonggi Province. Additionally, further investigation is required to provide a more convincing explanation for the significant population increase in the Mahan region during the period of Baekje's expansion.

PIEZO1 as a new target for hyperglycemic stress-induced neuropathic injury: The potential therapeutic role of bezafibrate

Hyperglycemic stress can directly lead to neuronal damage. The mechanosensitive ion channel PIEZO1 can be activated in response to hyperglycemia, but its role in hyperglycemic neurotoxicity is unclear. The role of PIEZO1 in hyperglycemic neurotoxicity was explored by constructing a hyperglycemic mouse model and a high-glucose HT22 cell model. The results showed that PIEZO1 was significantly upregulated in response to high glucose stress. In vitro experiments have shown that high glucose stress induces changes in neuronal cell morphology and membrane tension, a key mechanism for PIEZO1 activation. In addition, high glucose stress upregulates serum/glucocorticoid-regulated kinase-1 (SGK1) and activates PIEZO1 through the Ca2+ pool and store-operated calcium entry (SOCE). PIEZO1-mediated Ca2+ influx further enhances SGK1 and SOCE, inducing intracellular Ca2+ peaks in neurons. PIEZO1 mediated intracellular Ca2+ elevation leads to calcium/calmodulin-dependent protein kinase 2α (CaMK2α) overactivation, which promotes oxidative stress and apoptosis signalling through p-CaMK2α/ERK/CREB and ox-CaMK2α/MAPK p38/NFκB p65 pathways, subsequently inducing synaptic damage and cognitive impairment in mice. The intron miR-107 of pantothenic kinase 1 (PANK1) is highly expressed in the brain and has been found to target PIEZO1 and SGK1. The PANK1 receptor is activated by peroxisome proliferator-activated receptor α (PPARα), an activator known to upregulate miR-107 levels in the brain. The clinically used lipid-lowering drug bezafibrate, a known PPARα activator, may upregulate miR-107 through the PPARɑ/PANK1 pathway, thereby inhibiting PIEZO1 and improving hyperglycemia-induced neuronal cell damage. This study provides a new idea for the pathogenesis and drug treatment of hyperglycemic neurotoxicity and diabetes-related cognitive dysfunction.

#2570 Non-invasive blood pressure monitoring in dialysis patients using pulse wave velocity

Abstract Background and Aims Dialysis patients are at high risk of circulatory dysregulation and hypotension during treatment. Intradialytic hypotension (IDH) is a potentially life-threatening complication. The main causes are high ultrafiltration volumes and high ultrafiltration rates when patients tend to gain a lot of weight between dialysis treatments. A lack of patient compliance with regard to drinking volumes and a lack of residual diuresis are risk factors for this. Close circulatory monitoring and therapy settings to avoid absolute or relatively high UF rates to prevent IDH are frequently used. These are primarily the frequent non-invasive measurement of blood pressure using cuffs, the measurement of relative blood volume and the adjustment of ultrafiltration rates to these values. Prophylactically, the dialysis time can be extended, ultrafiltration profiles or ultrafiltration breaks can be planned, the dialysate temperature can be lowered and the composition of the dialysate can be adjusted. Despite all attempts, however, the incidence of IDH in everyday clinical practice is too high. The non-invasive measurements with cuffs are not carried out frequently enough, the measurement of the relative blood volume only covers a partial range, sudden changes in vascular tension or cardiac output are not recorded. Method The pulse wave velocity (PWV) is a well-known parameter for describing the propagation of the pressure wave after ejection of the heart beat volume in the arteries. The PWV is dependent on blood pressure, vessel wall tension and cardiac output. Changes in blood pressure can therefore be recognised by measuring the PWV. With the help of a measuring device (PESAS) for the ECG signal and peripheral pulse plethysmography, PWV can be measured non-invasively, continuously, for every heartbeat and, above all, hardly noticed by the patient. The PESAS allows the time-synchronised measurement of ECG and peripheral plethysmography curves and thus the determination of PWV. It is an experimental device. We would like to present a study showing the use of a measuring device (PESAS) in 15 prevalent dialysis patients for the detection of IDH. All study participants were examined during 3 dialysis treatments. Results The measurement of PWV in chronic dialysis patients during treatment is technically feasible. The measurement is tolerated by the patients. Changes in PWV could be detected in the patients during the course of dialysis; these were also dependent on the ultrafiltration rates. Individual patient reactions to volume withdrawal varied, with both increases and decreases in PWV being demonstrated. An acute change in PWV was usually associated with a drop in blood pressure. Continuous measurement allowed IDH events to be detected earlier than intermittent blood pressure measurement with cuffs. Sudden drops in blood pressure could be detected better and earlier with the PESAS system than by measuring the relative blood volume. Conclusion The PESAS system is suitable for monitoring dialysis patients to prevent IDH. Further adjustments and optimisation of the evaluation algorithms are necessary.

Laboratory study on the transformation of oil-water interface properties under direct current electric field

Interface tension is one of the important mechanisms that affect crude oil recovery and plays an important role in the development of tight oil reservoirs. Electrical-enhanced oil recovery can be used as a technology to reduce interfacial tension and improve crude oil recovery. In the previous research process of Electrical-enhanced oil recovery, the focus was more on the influence of electric field on wettability, and the understanding of the changes in interfacial tension under electric field action is not yet comprehensive. This article designs an orthogonal experiment to study the effect of electric field on oil-water properties. The degree of influence of three factors, namely sodium chloride solution concentration (C), direct current voltage (V), and voltage action time (t), on interfacial tension is studied. Gas chromatography, four component analysis, and Fourier transform infrared spectroscopy are combined to discuss the mechanism of the influence of changes in solution pH, crude oil components, and oil phase functional groups on interfacial tension. The results show that an external electric field can effectively reduce the interfacial tension between oil and water, and the maximum change in interfacial tension after the experiment can be reduced from 23.21 mN/m to 0.37 mN/m; Through range analysis, it can be concluded that the concentration of sodium chloride solution has the greatest impact on interfacial tension, followed by DC voltage and voltage action time. The optimal experimental conditions are 0.5 mol/L sodium chloride solution, 10 V DC voltage, and a voltage action time of 18 h, and the change in interfacial tension is related to the increase in pH value. The change in crude oil composition is also an important reason for the decrease in interfacial tension under external electric fields. Finally, Fourier transform infrared spectroscopy was used to determine that under the action of an electric field, the increase in pH of the sodium chloride solution resulted in the formation of carboxylate salts through chemical reactions between alkaline substances of solution and acidic substances of the oil, which were the key factors in reducing interfacial tension. This study helps to understand and explore the principles and mechanisms of Electrical-enhanced oil recovery in improving oil recovery, with the aim of contributing to the development and promotion of Electrical-enhanced oil recovery technology.

Relative Fundamental Frequency in Individuals with Globus Syndrome and Muscle Tension Dysphagia.

Relative fundamental frequency (RFF) has been investigated as an acoustic measure to assess for changes in laryngeal tension. This study aimed to assess RFF in individuals with globus syndrome, individuals with muscle tension dysphagia (MTDg), and individuals with typical voices. RFF values were calculated from the speech acoustics of individuals with globus syndrome (n=12), individuals with MTDg (n=12), and age- and sex-matched controls with typical voices (n=24). An analysis of variance was performed on RFF values to assess the effect of group. There was no statistically significant effect of group on RFF values, with similar values for individuals with globus syndrome, individuals with MTDg, and control participants. These results suggest that individuals with these disorders do not appear to possess paralaryngeal muscle tension in a locus and/or manner that directly impacts voice production.

Introduction to the Special Issue: Disrupted Language Teacher Identities in Times of Uncertainty

The English language teaching (ELT) profession is at its precipice with large-scale global events and transitions in the recent decade. Changes in global alliances, international conflicts, geopolitical tensions, wars, economic crises, and global climate changes brought uncertainties to the world and the ELT landscape. In this special issue, Between Indisposition and Perseverance: Disrupted Language Teacher Identities in Times of Uncertainty, we explore how English language teachers, researchers, and professionals grapple with indispositions from social, historical, political, economic, and emotional dilemmas in times of uncertainty. [First paragraph of the introduction to the special issue]

Hypoxia Exposure Fine-Tunes Mitochondrial Function in Primary Dermal Fibroblasts Derived from Loggerhead Sea Turtles

Sea turtles are constantly exposed to changes in oxygen tension derived from extended breath-hold diving, but the cellular-level response to such changes is not completely understood. Most studies in hypoxia-tolerant reptiles have focused on the freshwater turtle Trachemys scripta, which responds to anoxia by inducing metabolic rewiring and preserving mitochondrial integrity, facilitating effcient mitochondrial respiration during reoxygenation. Here, we derived primary dermal fibroblasts from loggerhead sea turtles and western fence lizards to study the bioenergetic cellular response to hypoxia exposure in diving and non-diving reptiles. Cells from both species stained positive for the fibroblast markers vimentin and PDGFRb and responded to hypoxia exposure (0.1% O2) by accumulating HIF-1α. We measured oxygen consumption rates (OCR) in intact cells using Seahorse technology. We found that basal, maximal, and spare respiratory capacity was lower in lizard than in loggerhead cells at 26oC under normoxic (room air) conditions (p < 0.0001). Exposure to short (1h) and long-term hypoxia (24h) altered mitochondrial function in both species. Maximal and spare respiratory capacity were lower in loggerhead than in lizard cells (p < 0.01) after 1h hypoxia followed by 1h reoxygenation. In contrast, basal and maximal respiratory capacity was higher in loggerhead compared to lizard cells after 24h hypoxia (p < 0.04). Nonetheless, the overall OCR after 24h hypoxia in both species was lower than that observed after 1h hypoxia. Overall, there was a significant reduction in cellular respiration in both species from short-term to long-term hypoxia exposure. In lizard cells, basal OCR decreased by a factor of three while maximal OCR decreased by a factor of 4.5. In loggerhead cells, both the basal and maximal OCR decreased by a factor of two. Our results demonstrate species-specific regulation of cellular respiration after hypoxia exposure. Remarkably, loggerhead cells show a steady downregulation of cellular respiration in response to hypoxia exposure and faster recovery after extended hypoxia (24h) than lizard cells, aligning with the remarkable hypoxic tolerance exhibited by sea turtles, which can endure up to 7 hours of breath-holding underwater. Understanding the cellular mechanisms that drive hypoxic tolerance in diving animals can provide insights for treating human conditions characterized by hypoxia signaling. Ford Foundation. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Empagliflozin, an SGLT2i, relaxes coronary smooth muscle at pharmacological concentrations

Morbidity and mortality due to heart failure with preserved ejection fraction (HFpEF) is increasing and there are no universally recognized strategies for treatment. Sodium-glucose co-transporter type 2 inhibitors (SGLT2i), such as Empagliflozin, have been shown to reduce myocardial stiffness and improve coronary microvascular performance, but mechanisms are unclear. Previous studies in rabbit aorta and rat mesentery suggest Empagliflozin relaxes smooth muscle through activation of K+ channels. This study investigated the effects of therapeutic and pharmacological concentrations of Empagliflozin (10-300 μM) on the isometric tension of left circumflex (CFX) coronary arteries from Yorkshire swine. We tested the hypothesis that Empagliflozin would relax coronary smooth muscle via a concentration-dependent manner, involving K+ channels. CFX arteries were dissected, cleaned of adventitia, cut into 3 mm rings (n = 16), and mounted in organ baths containing Krebs-Henseleit buffer (37 °C) for isometric tension studies. Each CFX segment was adjusted to optimal preload (~3 g passive tension) as determined by <10 % change in active tension in response to 60 mM KCl. In order to determine whether Empagliflozin caused relaxation and, if so, by what mechanism, rings were contracted with either 30 mM K+ or the thromboxane mimetic U46619 (1 μM). Once tension plateaued, Empagliflozin (10-300 μM) was added in increasing concentrations. Therapeutic concentrations of Empagliflozin (10-30 μM), elicited no significant relaxation. Pharmacologic concentrations of Empagliflozin (≥100 μM) caused significant relaxation from ~15 ± 11% to ~45 ± 10% in response to 100 μM vs. 300 μM Empagliflozin, respectively. Relaxation was not different between rings contracted with K+ or U46619, suggesting membrane hyperpolarization via K+ channels is not involved. Our results represent the first study of the effects of Empagliflozin on coronary smooth muscle reactivity. Data support the idea that relaxation of coronary smooth muscle by Empagliflozin occurs at supra-pharmacologic concentrations in vitro, but K+ channel activation appears to be an unlikely mechanism. This project was supported by National Institutes of Health grant R01 HL158723. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Beverage Deterioration Monitoring Based on Surface Tension Dynamics and Absorption Spectrum Analysis

Biochemical information sensing has always been one of the challenges in ubiquitous sensing research for mobile computing. Microorganisms will cause undetectable deterioration in drink production, such as wine and beverage, and microbial contamination is highly susceptible during storage like some liquors can be bottled for sometimes over ten years. Microbial culture methods are common for quality monitoring but unsuitable for real-time beverage quality monitoring. As far as we know, we are the first to use ubiquitous sensing for real-time microbial contamination detection. We designed a lightweight monitoring system called Microbe-Radar, which uses light signals to monitor real-time beverage quality. Microbe-Radar uses eight LEDs and a photodiode to detect fine-grained surface tension and absorption spectrum changes caused by microbial metabolites and growth during deterioration. Characteristic offset degree measurement and absorption spectrum dimension expansion are two critical technologies. Moreover, we implemented countermeasures against ambient light noise and sloshing interference. Microbe-Radar's surface tension and absorption spectrum measurement errors are only 0.89 mN/m and 2.4%, respectively, making identifying the contamination duration, microorganism content, and microorganism composition worthwhile. Experiments showed Microbe-Radar could determine potential issues with liquor quality when the liquid becomes health-threatening or even just contaminated, with an accuracy of 97.5%. Microbe-Radar can also be extended to beverage deterioration warning, with deterioration prediction accuracy of more than 90.6% for five beverages (milk, apple juice, etc.).

Analysis of time sequence and load of pulling rope mechanism of type D-knotter

To solve the problem that the rope pulling plate may be delayed in the actual work of the knotter, the influence of the change of the timing of the rope pulling mechanism on the knotter forming performance was studied and analyzed. The dynamic model of the flexible bundling of the knotting machine is established using the Bushing connection of RecurDyn. The timing of the bundling machine homing is controlled by modifying the driving function of the bundling machine, and the positive pressure of the hook pliers is obtained by measuring the contact force between the bundle and the hook pliers. The results of the contact force curve show that the maximum positive pressure of the hook pliers for the normal homing of the rope plate is 290.43 N. The maximum value of the sudden change of tension can reach 837.17 N, which proves that the change in the timing of the rope pulling mechanism has a significant influence on the positive pressure of the hook pliers.