Mechanism Of Rupture Research Articles

PROSPECTS FOR THE USE OF PROBIOTIC ENCAPSULATION PROCESS

This article discusses the various types, encapsulation stages, and polymers for encapsulating probiotics. The article reflects several methods of encapsulation, such as spray drying, spray freezing, emulsification, extrusion method, etc. Encapsulation allows isolating the encapsulated material from the surrounding environment until its release occurs. The structure formed by the encapsulating agent around the encapsulated material can be tailored to protect the contents and ensure their release under certain conditions. The size of capsules can range from submicron to several millimeters, and their shape can vary. The content of the capsule can be released through various pathways: mechanical rupture of the capsule, dissolution of the capsule, melting of the capsule, or diffusion through the capsule wall.In our time, a large number of people suffer from gastrointestinal diseases. Encapsulation of dietary supplements (BAA) will help replenish the deficiency of microelements in the human body. The article demonstrates that the use of encapsulated forms of probiotic cultures in the food industry, especially in the production of dairy products, will not only preserve the viability of the applied microorganisms but also provide favorable conditions for their development in the human body.

Damage Evolution Characteristics and Constitutive Model for Coal and Rock under Asymmetric Loading.

Tunnels and shaft mining roadways are often subjected to varying degrees of asymmetric loading due to terrain relief or project excavation. In order to analyze the influence of the asymmetric degree of loading on the mechanical properties and damage rupture law of coal rock, uniaxial compression tests of coal rock under four asymmetric loading modes were carried out, the influence of the asymmetric coefficients of loading on macro- and micromechanical properties of coal and rock was analyzed, and a statistical damage constitutive model of coal and rock was established to reflect the asymmetric loading degree. The results of the study show that the peak stress of the coal rock decreases gradually with the increase in the asymmetric coefficient of loading, and the two are linear functions of each other. The distribution of the acoustic emission ringing count peak value is concentrated under uniform loading, while the acoustic emission ringing count rate presents a multipeak phenomenon under asymmetric loading, and the peak value points are scattered. In the case of asymmetric loading, the stress concentration on the edge of the upper loading plate leads to shear failure, and the microscopic cracks are concentrated near the interface between the loading zone and the nonloading zone. According to the established damage constitutive model, when the damage degree is the same, the larger the asymmetric coefficient, the smaller the strain value, which indicates that the asymmetric loading promotes the damage of coal and rock.

Deletion of Transient Receptor Channel Vanilloid 4 Aggravates CaCl2-Induced Abdominal Aortic Aneurysm and Vascular Calcification: A Histological Study

Vascular calcification is calcium deposition occurring in the wall of blood vessels, leading to mechanical stress and rupture due to a loss of elasticity and the hardening of the vessel wall. The role of the Transient Receptor Channel Vanilloid 4 (TRPV4), a Ca2+-permeable cation channel, in the progression of vascular calcification is poorly explored. In this study, we investigated the role of TRPV4 in vascular calcification and the development of abdominal aortic aneurysm (AAA). Experimental mice were randomly divided into four groups: wild-type (WT) sham operated group, WT CaCl2-induced aortic injury, TRPV4-KO sham operated group, and TRPV4-KO CaCl2-induced aortic injury. The TRPV4-knockout (TRPV4-KO) mice and wild-type (WT) mice were subjected to the CaCl2-induced abdominal aortic injury. In histopathological analysis, the aorta of the TRPV4-KO mice showed extensive calcification in the tunica media with a significant increase in the outer diameter (p < 0.0001), luminal area (p < 0.05), and internal circumference (p < 0.05) after CaCl2 injury when compared to WT mice. Additionally, the tunica media of the TRPV4-KO mice aorta showed extensive damage with apparent elongation and disruption of the elastic lamella. These results indicate a protective function of TRPV4 against vascular calcification and the progression of AAA after CaCl2 injury.

A high-content screen reveals new regulators of nuclear membrane stability

Nuclear membrane rupture is a physiological response to multiple in vivo processes, such as cell migration, that can cause extensive genome instability and upregulate invasive and inflammatory pathways. However, the underlying molecular mechanisms of rupture are unclear and few regulators have been identified. In this study, we developed a reporter that is size excluded from re-compartmentalization following nuclear rupture events. This allows for robust detection of factors influencing nuclear integrity in fixed cells. We combined this with an automated image analysis pipeline in a high-content siRNA screen to identify new proteins that both increase and decrease nuclear rupture frequency in cancer cells. Pathway analysis identified an enrichment of nuclear membrane and ER factors in our hits and we demonstrate that one of these, the protein phosphatase CTDNEP1, is required for nuclear stability. Analysis of known rupture determinants, including an automated quantitative analysis of nuclear lamina gaps, are consistent with CTDNEP1 acting independently of actin and nuclear lamina organization. Our findings provide new insights into the molecular mechanism of nuclear rupture and define a highly adaptable program for rupture analysis that removes a substantial barrier to new discoveries in the field.

Colorimetric sensor based on release control from liposomes by the formation of 2,2-bipyridine-Fe2+ complex

In colorimetric detection, an analyte may be determined both qualitatively and quantitatively by keeping track of color changes that seem to be perceptible to the unaided eye. The uniform liposomes with diameters of 100 nm were synthesized from sphingomyelin and cholesterol. We comprehensively assessed 2,2-bipyridine's capacity to release from liposomes as well as the color shift to dark red caused by the formation of complexes between Fe2+ and 2,2-bipyridine for colorimetric detection. In addition, we extensively evaluated and examined factors influencing liposomal membrane leakage, such as pH value change, bulkiness of the molecular structure (2,2-bipyridine and doxorubicin), and the membrane rupture mechanism of triton X100. To provide the best circumstances for the color sensor from these liposomes, pH conditions and concentrations of triton X100 and Fe2+ were optimized. In addition, it has been confirmed and thoroughly described how pH breaks the liposome membrane and how Fe2+-Bipy changes color. The capacity to release from liposomes throughout time was studied via analysis of kinetic release models, including Fick's law, the Higuchi model, and the Korsmeyer-Peppas model. Our approach develops a method to is straightforward, quick to detect, and easily applied. This research holds promise as color color-sensing method for detecting viruses and pathogens in the future.

Myosin-induced F-actin fragmentation facilitates contraction of actin networks.

Mechanical forces play a crucial role in diverse physiological processes, such as cell migration, cytokinesis, and morphogenesis. The actin cytoskeleton generates a large fraction of the mechanical forces via molecular interactions between actin filaments (F-actins) and myosin motors. Recent studies have shown that the common tendency of actomyosin networks to contract into a smaller structure deeply involves F-actin buckling induced by motor activities, fragmentation of F-actins, and the force-dependent unbinding of cross-linkers that inter-connect F-actins. The fragmentation of F-actins was shown to originate from either buckling or tensile force from previous single-molecule experiments. While the role of buckling in network contraction has been studied extensively, to date, the role of tension-induced F-actin fragmentation in network contraction has not been investigated. In this study, we employed in vitro experiments and an agent-based computational model to illuminate when and how the tension-induced F-actin fragmentation facilitates network contraction. Our experiments demonstrated that F-actins can be fragmented due to tensile forces, immediately followed by catastrophic rupture and contraction of networks. Using the agent-based model, we showed that F-actin fragmentation by tension results in distinct rupture dynamics different from that observed in networks only with cross-linker unbinding. Moreover, we found that tension-induced F-actin fragmentation is particularly important for the contraction of networks with high connectivity. Results from our study shed light on an important regulator of the contraction of actomyosin networks which has been neglected. In addition, our results provide insights into the rupture mechanisms of polymeric network structures and bio-inspired materials.

Mechanical properties and energy evolution of drilling shaft lining concrete under hydro-mechanical coupling

As the drilling shafts in the western mines of China are going to cross the deep water-rich and weakly cemented rock layer, investigating the mechanical properties and energy evolution of shaft lining concrete within the context of hydro-mechanical coupling is crucial. In this study, concrete compression tests were conducted using the TAW-2000 rock testing machine. The concrete damage and rupture mechanisms were analyzed using a combination of mercury intrusion porosimetry and scanning electron microscopy. Moreover, a thorough investigation of the energy evolution throughout the concrete stress-strain process was conducted. The key results include the following: (1) The formulation of the normalized decay equation for the characteristic strength of concrete under hydraulic coupling was derived by computing the ratio of pore water pressure to confining pressure as the characteristic parameter. (2) The effective shear strength reduction factor characterizing the impact of water pressure on the effective shear stress with a correlation coefficient greater than 0.999. (3) The pore water pressure adversely affected the pore size distribution within the concrete, enhancing the connectivity between pores. (4) The total input energy, elastic energy, and dissipated energy were positively related to the confining pressure and negatively related to the pore water pressure. The energy consumption ratio served as a tentative criterion for assessing the strength failure of the shaft lining concrete, which is considered to be in a critically stable state when the energy consumption ratio is 1. These results provided valuable insights into the damage laws and energy-driven mechanisms of shaft-lining concrete under hydraulic coupling conditions.

Towards the mechanical characterisation of unruptured intracranial aneurysms: Numerical modelling of interactions between a deformation device and the aneurysm wall

Intracranial aneurysm is a critical pathology related to the arterial wall deterioration. This work is an essential aspect of a large scale project aimed at providing clinicians with a non-invasive patient-specific decision support tool regarding the rupture risk assessment. A machine learning algorithm links the aneurysm shape observed and a database of UIA clinical images associated with in vivo wall mechanical properties and rupture characterisation. The database constitution is derived from a device prototype coupled with medical imaging. It provides the mechanical characterisation of the aneurysm from the wall deformation obtained by inverse analysis based on the variation of luminal volume. Before performing in vivo tests of the device on small animals, a numerical model was built to quantify the device’s impact on the aneurysm wall under natural blood flow conditions. As the clinician will never be able to precisely situate the device, several locations were considered. In preparation for the inverse analysis procedure, artery material laws of increasing complexity were studied (linear elastic, hyper elastic Fung-like).Considering all the device locations and material laws, the device induced relative displacements to the Systole peak (worst case scenario with the highest mechanical stimulus linked to the blood flow) ranging from 375 μm to 1.28 mm. The variation of luminal volume associated with the displacements was between 0.95 % and 4.3 % compared to the initial Systole volume of the aneurysm. Significant increase of the relative displacements and volume variations were found with the study of different cardiac cycle moments between the blood flow alone and the device application. For forthcoming animal model studies, Spectral Photon CT Counting, with a minimum spatial resolution of 250 μm, was selected as the clinical imaging technique. Based on this preliminary study, the displacements and associated volume variations (baseline for inverse analyse), should be observable and exploitable.

Ag/MoS2 nanozyme-modified ZnO nanopillar surface for enhanced synergistic mechanical and chemical antibacterial activity

Bacterial infection and contamination is a tough problem that generates numerous hazardous factors in areas ranging from human health, clinical to industrial manufacture. Here, an Ag/MoS2 nanozyme-modified ZnO nanopillar surface was designed and assembled. This nanopillar surface can achieve remarkable antibacterial effects against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. The obtained nanozyme-modified nanopillar surface demonstrated mechanical antibacterial property with a killing rate of 69.6% and 70.4% to Staphylococcus aureus and Escherichia coli, respectively. Moreover, the surface disables bacteria under H2O2 efficiently, reaching a lethality rate of 89.7% and 98.4% in 30 min, respectively. The superiorities of fast and high lethality rate are owed to a synergistic antibacterial functions consisted of mechanical rupture, enormous ROS generation and silver ions release. Meanwhile, the nanozyme-modified nanopillar surface also shows the surface superhydrophobic property with an antibacterial adhesion rate of over 99.9%. Therefore, the scheme pdresented in this study can provide a potential perspective to solve bacterial infection and contamination in the fields of daily life, clinical and industrial manufacture.

Evolution and breakup of a ferrofluid droplet neck through a capillary tube

The controlled generation of droplets is crucial in bioassays, chemical analysis, and inkjet printing. Despite progress in droplet formation dynamics within liquid–liquid systems, improving the controllability and flexibility of manipulating droplets is still necessary. Here, we employ a non-uniform magnetic field for non-contact control of ferrofluid droplet generation in a vertical capillary. A correlation function predicts final ferrofluid droplet volumes with an average relative error of only 6.33%. Our study demonstrates that the magnetic field actively regulates droplets' volume, deformation, and generation period. In the final stages of droplet formation, we observe a unique neck rupture mechanism influenced by the viscosity of the continuous-phase fluid, distinct from observations in air. Scaling laws fit the minimum neck and position variations, revealing self-similar neck rupture behavior for droplets at different Bond and Weber numbers. These insights into droplet dynamics have potential applications across various technological domains.

The Injury Mechanism of Achilles Tendon Rupture in Professional Athletes: A Video Analysis Study.

In professional athletes, Achilles tendon ruptures are devastating injuries, often resulting in season loss or decreased return to sports level. We aimed to perform a comprehensive video analysis to describe the mechanisms of Achilles tendon rupture as well as body posture in professional athletes. We hypothesized that Achilles tendon ruptures in professional athletes develop with a specific injury mechanism and that body posture at the time of injury varies by sport. Of 114 identified Achilles tendon ruptures that occurred in professional athletes between 1970 and 2020, 42 with adequate video data were analyzed for injury mechanism, body posture, and player and sport characteristics by three independent reviewers. Mean ± SD age of the 42 athletes (41 men and 1 woman) was 28.4 ± 4.26 years. Eighteen athletes played basketball (42.9%), 14 football (33.3%), five soccer (11.9%), three baseball (7.1%), and two rugby (4.8%). Thirty-five patients (83.3%) had noncontact injuries. The most frequent months of injury were January (16.7%) and October (14.3%). During Achilles tendon rupture, the ankle was in dorsiflexion, the body was bent forward, the knee and hip were in extension, and the foot was in a neutral position. Most injuries occurred during take-off/acceleration (40.5%) or stop and turn (38.5%) maneuvers. In professional athletes, the Achilles tendon most often ruptures during take-off/acceleration. The most common position during rupture is the trunk in flexion, the knee and hip in extension, and the ankle in dorsiflexion. This information can guide professional athletes in terms of physical therapy techniques, including neuromuscular training, proprioception, and balance training specific to preventing Achilles tendon rupture.

Extremely thin intermetallic layer in dissimilar AA6061-T6 and mild steel friction stir lap welding using a hemispherical tool

The dissimilar friction stir lap welding of AA6061-T6 and mild steel using the hemispherical tool tilted towards the retreating side is investigated. Critical defects such as hook features and internal voids are avoided by limiting the plunge depth in the lower plate to a tenth of a millimeter. The low heat generation guaranteed by the hemispherical tool produces a nanoscale intermetallic compound layer alternatively composed of an Al-rich and a ternary Al–Fe–Mg phases. The complex and extremely thin interlayers strengthen the Al–Fe mechanical bonding, guaranteeing high mechanical properties and rupture within the Al-stirred zone. Thermomechanical phenomena governing friction stir lap welding with the hemispherical tool drastically limit the growth of intermetallics, leading to the high mechanical strength of the lap joint.

Observation of Long-Lived Plasma Formations in a Toroidal air Vortex under Normal Conditions

Purpose. Experimentally investigate the difference between the characteristic lifetime of plasma formations in a stationary and rotating toroidal air volume under normal ambient conditions.Methods. Experimental study of plasmoids was carried out by videotaping with a high-speed camera with subsequent frame-by-frame processing of the recording. Generation of plasmoids was performed by mechanical rupture of the plasma cord of the welding arc in the field of permanent magnets. The creation of toroidal rotation of the plasma formation in air occurs when it passes through a hole in a solid screen. Numerical estimation of mechanical forces acting on ions in the air vortex is performed by order of magnitude using experimental data.Results. Two different in design laboratory installations for observation of plasma formations in air under normal external conditions have been created. The lifetime of such "long-lived" plasmoids in air is equal to about two milliseconds, which significantly exceeds the lifetime of a plasma-forming welding arc in the free state under the same conditions. The increase in plasmoid lifetime is considered and explained within the framework of mechanical ideas about spatial separation of heavy and light ions inside the plasma under the action of inertia forces as a result of rotational motion of air. The proposed mechanical model of the phenomenon is obviously simplified and does not take into account diffusion, recombination and other related phenomena, since the main and only difference between the observed "longlived" and "ordinary" plasmoids lies in the nature of the mechanical motion of the medium.Conclusion: Two experimental setups allowing to generate and observe the behavior of plasma formations with a characteristic lifetime of the order of two milliseconds are created and described. The results of observations indirectly confirm a simple mechanical hypothesis about the connection between the lifetime of a free plasma formation and the rotational motion of the gas inside it.

Sensitivity analysis of the mechanical properties on atherosclerotic arteries rupture risk with an artificial neural network method

Considering the differences between individuals, in this paper, an uncertainty analysis model for predicting rupture risk of atherosclerotic arteries is established based on a back-propagation artificial neural network. The influence of isotropy and anisotropy on the rupture risk of atherosclerotic arteries is analyzed, and the results demonstrate the effectiveness of the artificial neural network in predicting the rupture risk. Moreover, the rupture risk of atherosclerotic arteries at different inflation sizes are simulated. This study contributes to a better understanding of the underlying mechanisms of atherosclerotic arteries rupture and promotes the advancement of artificial neural networks in atherosclerosis research.

Biomechanical Characterization of Abdominal Aortic Aneurysm: The Rupture Mechanism

In this work, a four-week-old male C57Bl/6 mouse model of abdominal aortic aneurysm (AAA) was developed to examine the AAA rupture mechanism. Immunofluorescence staining was adopted for quantifying the degradation of elastin, and Picrosirius Red staining was adopted for evaluating the density of collagen. Atomic force microscopy with two probe tip sizes of 5 µm and 20 nm was adopted for mechanical characterization of the AAA. The microstructure changes and stiffness changes in both AAA samples and controlled samples were inspected. The degradation of elastin, wall thickening, formation of micro vessels, and increased density of collagen were observed in the AAA samples. The AAA samples also exhibited fragmented texture from AFM scanning. The histogram of stiffness measurements of the AAA samples with a 20 nm tip demonstrated two unique peak frequencies of stiffness intervals (0–10 kPa and 40–50 kPa). The stiffer regions were correlated with the increased density of collagen, as shown in the immunofluorescence images. The softer regions, combined with the fragmented texture, could be the key index contributing to the initiation and propagation of AAA rupture. Overall, the AAA group showed a higher stiffness than the control group (50.77 ± 62.4 kPa vs. 40.6 ± 51.86 kPa). The findings from this work may help in explaining ruptures in small AAA (<5.5 mm), which account for ten percent of all AAA ruptures. Additionally, the observations in this study may help develop early detection methods and innovative treatments for AAA.

Low voltage cold and hot switching in nanoswitches cleaned by in situ oxygen plasma can achieve low stable contact resistance

Reliable nanoswitch operation requires low contact voltages and stable electrical contact resistance (ECR). Surface cleanliness is crucial to prevent nanomechanical switch failure, which can occur due to the presence of insulating adventitious hydrocarbon films. In situ O2 plasma cleaning is effective but oxidizes metal surfaces. Here, the noble metal Pt, which forms PtOx, is employed to form electrodes. Previous studies report on PtOx electrical resistivity, but the effects of PtOx evolution at contacting interfaces due to electrical and mechanical stimuli have not been explored. This study investigates the impact of PtOx on ECR at low contact voltages under hot switching, cold switching, and mechanical cycling conditions. An increase in ECR upon plasma cleaning indicates the presence of a resistive PtOx layer. After hot and cold switch cycling at applied voltages of 300 mV or less, a low stable ECR is achieved. A higher contact voltage accelerates ECR stabilization. The results are consistent with PtOx film volatilization, which is primarily due to Joule heating rather than mechanical rupture. This investigation advances the understanding of interface evolution in plasma-cleaned nanoswitches.

Mechanics and microstructure of blood plasma clots in shear driven rupture.

Intravascular blood clots are subject to hydrodynamic shear and other forces that cause clot deformation and rupture (embolization). A portion of the ruptured clot can block blood flow in downstream vessels. The mechanical stability of blood clots is determined primarily by the 3D polymeric fibrin network that forms a gel. Previous studies have primarily focused on the rupture of blood plasma clots under tensile loading (Mode I), our current study investigates the rupture of fibrin induced by shear loading (Mode II), dominating under physiological conditions induced by blood flow. Using experimental and theoretical approaches, we show that fracture toughness, i.e. the critical energy release rate, is relatively independent of the type of loading and is therefore a fundamental property of the gel. Ultrastructural studies and finite element simulations demonstrate that cracks propagate perpendicular to the direction of maximum stretch at the crack tip. These observations indicate that locally, the mechanism of rupture is predominantly tensile. Knowledge gained from this study will aid in the development of methods for prediction/prevention of thrombotic embolization.

Dynamic Rupture of the 2021 MW 7.4 Maduo Earthquake: An Intra‐Block Event Controlled by Fault Geometry

AbstractThe 2021 MW 7.4 Maduo event occurred within the Bayan Har block in eastern Tibet, which provides an opportunity to investigate the stress conditions and rheology of faults within the block. Here, we perform dynamic rupture simulations based on the finite element method to explore the physical conditions underlying this earthquake and the factors that controlled the rupture process. We construct the model with a nonplanar fault inferred from the Interferometric Synthetic Aperture Radar (InSAR) data and aftershocks sequence relocation. Our dynamic model is controlled by slip‐weakening friction law with initial stress on fault resolved from a uniform regional stress field. The preferred model produces an average slip of ∼2.2 m with a maximum slip of ∼4.0 m. There are three asperities distributed along the strike, which have captured the main features of the Maduo event. The simulation results are consistent with the static GPS coseismic surface displacements, InSAR data, and displacement waveforms recorded by high‐rate GNSS stations. By comparing the results with the planar fault model and rotated stress fields, we find that the fault geometry and regional stress field are the primary factors that control the rupture process of the event. Moreover, we infer that the unfavorable orientation and fault bend lead to minor slips on the branch fault. Furthermore, we investigate the potential mechanisms of supershear rupture on the eastern fault segment.

Investigation of Multiaxial Creep Rupture Mechanisms and Life Prediction in High-Temperature Alloys Under Complex Environments

Investigation of Multiaxial Creep Rupture Mechanisms and Life Prediction in High-Temperature Alloys Under Complex Environments

Earthquake prediction based on the analysis of water level fluctuations in the control well

This study examines the methodology and results of earthquake forecasting based on the assumption that the earthquake preparation process can be linked to the development of rupture mechanisms. The analysis focuses on water fluctuations in a control monitoring well, which provides valuable information about the earthquake’s preparation period well in advance. Studies on the territory of the Kryvyi Rih iron ore basin (Kryvbas) confirmed that the underground waters in a deep well (815 m deep) depend on the processes of the current lithosphere deformations evidenced by the changing elastic-deformation state of the crust in tectonic areas. The Kryvyi Rih-Kremenchuk crust-mantle fault produces a system of different-scale faults in the crystalline basement which determine the hydrodynamics of the Kryvbas underground filtration. The earthquake preparation process exhibits clear indicators of the rupture process, characterized by a periodic component of water fluctuations superimposed on the main level-changing process during the preparatory phase. The frequency of the periodic component increases as the date of the earthquake approaches. With this approach, an earthquake with a magnitude of 4.1 inKryvbas was successfully predicted one and a half year before the event, based on monitoring water level fluctuations for 120 days between February and June 2016. The efficacy of forecasting local earthquakes was evaluated using the retro-forecast of earthquakes in Kryvbas on July 29, 2017. The methodology was validated through testing, confirming the initial assumptions. This technique was tested to predict the exacerbation of the seismic situation in the iron ore mining area caused by powerful blasting activities.