Coaching ribosome biogenesis from the nuclear periphery.

Severe invagination of the nuclear envelope is a hallmark of cancers, aging, neurodegeneration, and infections. However, the outcomes of nuclear invagination remain unclear. This work identified a new function of nuclear invagination: regulating ribosome biogenesis. With expansion microscopy, we observed frequent physical contact between nuclear invaginations and nucleoli. Surprisingly, the higher the invagination curvature, the more ribosomal RNA and pre-ribosomes are made in the contacted nucleolus. By growing cells on nanopillars that generate nuclear invaginations with desired curvatures, we can increase and decrease ribosome biogenesis. Based on this causation, we repressed the ribosome levels in breast cancer and progeria cells by growing cells on low-curvature nanopillars, indicating that overactivated ribosome biogenesis can be rescued by reshaping nuclei. Mechanistically, high-curvature nuclear invaginations reduce heterochromatin and enrich nuclear pore complexes, which promote ribosome biogenesis. We anticipate that our findings will serve as a foundation for further studies on nuclear deformation.

Consistent Thermal Conductivities of Spring-Like Structured Polydimethylsiloxane Composites under Large Deformation.

Flexible and highly thermally conductive materials with consistent thermal conductivity (λ) during large deformation are urgently required to address the heat accumulation in flexible electronics. In this study, spring-like thermal conduction pathways of silver nanowire (S-AgNW) fabricated by 3D printing are compounded with polydimethylsiloxane (PDMS) to prepare S-AgNW/PDMS composites with excellent and consistent λ during deformation. The S-AgNW/PDMS composites exhibit a λ of 7.63 W m-1 K-1 at an AgNW amount of 20 vol%, which is ≈42 times that of PDMS (0.18 W m-1 K-1) and higher than that of AgNW/PDMS composites with the same amount and random dispersion of AgNW (R-AgNW/PDMS) (5.37 W m-1 K-1). Variations in the λ of 20 vol% S-AgNW/PDMS composites are less than 2% under a deformation of 200% elongation, 50% compression, or 180° bending, which benefits from the large deformation characteristics of S-AgNW. The heat-transfer coefficient (0.29 W cm-2 K-1) of 20 vol% S-AgNW/PDMS composites is ≈1.3 times that of the 20 vol% R-AgNW/PDMS composites, which reduces the temperature of a full-stressed central processing unit by 6.8 °C compared to that using the 20 vol% R-AgNW/PDMS composites as a thermally conductive material in the central processing unit.

Sensing the squeeze: nuclear mechanotransduction in health and disease.

The nucleus not only is a repository for DNA but also a center of cellular and nuclear mechanotransduction. From nuclear deformation to the interplay between mechanosensing components and genetic control, the nucleus is poised at the nexus of mechanical forces and cellular function. Understanding the stresses acting on the nucleus, its mechanical properties, and their effects on gene expression is therefore crucial to appreciate its mechanosensitive function. In this review, we examine many elements of nuclear mechanotransduction, and discuss the repercussions on the health of cells and states of illness. By describing the processes that underlie nuclear mechanosensation and analyzing its effects on gene regulation, the review endeavors to open new avenues for studying nuclear mechanics in physiology and diseases.

Gradient failure mechanism and control technology of deep roadways under the action of deviatoric stress field.

Deformation control of deep roadways is a major challenge for mine safety production. Taking a deep roadway with a burial depth of 965 m in a mine in North China as the engineering background, on-site investigation found that significant creep deformation occurred in the surrounding rock of the roadway. The original supporting U-shaped steel support failed due to insufficient supporting strength. The rock mass near the roadway experienced a transition from triaxial stress conditions to biaxial and even uniaxial stress states as a result of excavation and unloading, leading to a gradient stress distribution in the surrounding rock. From the perspective of the roadway's deviatoric stress field distribution, we investigated the gradient failure mechanism of the roadway and validated it through theoretical analysis and numerical simulations. The study found that the ratio of horizontal principal stress and vertical principal stress determines the distribution shape of the surrounding rock deviatoric stress field. The gradient distribution of the stress field in the roadway will cause time-related deformation of the roadway, which will lead to large deformation and failure of the roadway. Based on this, the control mechanism of roadway gradient failure was studied, and then a combined support technology of CFST supports with high bearing capacity was proposed.

Three-dimensional finite element analysis of the biomechanical behaviour of different dental implants under immediate loading during three masticatory cycles.

The study aimed to evaluate the impact of varying modulus of elasticity (MOE) values of dental implants on the deformation and von Mises stress distribution in implant systems and peri-implant bone tissues under dynamic cyclic loading. The implant-bone interface was characterised as frictional contact, and the initial stress was induced using the interference fit method to effectively develop a finite element model for an immediately loaded implant-supported denture. Using the Ansys Workbench 2021 R2 software, an analysis was conducted to examine the deformation and von Mises stress experienced by the implant-supported dentures, peri-implant bone tissue, and implants under dynamic loading across three simulated masticatory cycles. These findings were subsequently evaluated through a comparative analysis. The suprastructures showed varying degrees of maximum deformation across zirconia (Zr), titanium (Ti), low-MOE-Ti, and polyetheretherketone (PEEK) implant systems, registering values of 103.1 µm, 125.68 µm, 169.52 µm, and 844.06 µm, respectively. The Zr implant system demonstrated the lowest values for both maximum deformation and von Mises stress (14.96 µm, 86.71 MPa) in cortical bone. As the MOE increased, the maximum deformation in cancellous bone decreased. The PEEK implant system exhibited the highest maximum von Mises stress (59.12 MPa), whereas the Ti implant system exhibited the lowest stress (22.48 MPa). Elevating the MOE resulted in reductions in both maximum deformation and maximum von Mises stress experienced by the implant. Based on this research, adjusting the MOE of the implant emerged as a viable approach to effectively modify the biomechanical characteristics of the implant system. The Zr implant system demonstrated the least maximum von Mises stress and deformation, presenting a more favourable quality for preserving the stability of the implant-bone interface under immediate loading.

3D dataset of a twisted bending-active beam element digitized using structure-from-motion photogrammetry.

The current work presents the generation of a comprehensive spatial dataset of a lightweight beam element composed of four twisted plywood strips, achieved through the application of Structure-from-Motion (SfM) - Multi-view Stereo (MVS) photogrammetry techniques in controlled laboratory conditions. The data collection process was meticulously conducted to ensure accuracy and precision, employing scale bars of varying lengths. The captured images were then processed using photogrammetric software, leading to the creation of point clouds, meshes, and texture files. These data files represent the 3D model of the beam at different mesh sizes (raw, high-poly, medium-poly, and low-poly), adding a high level of detail to the 3D visualization. The dataset holds significant reuse potential and offers essential resources for further studies in numerical modeling, simulations of complex structures, and training machine learning algorithms. This data can also serve as validation sets for emerging photogrammetry methods and form-finding techniques, especially ones involving large deformations and geometric nonlinearities, particularly within the structural engineering field.

The Influence of the Diameter of Orthodontic Mini-Implants on Primary Stability: Bending Tests-An In Vitro Study.

Orthodontic Mini-Implants have a high success rate, but it is crucial to assess the load that they bear in order to maintain their primary stability. Increasing the diameter can improve this stability, but there are limitations due to the proximity of the tooth roots. To avoid damage, smaller diameters are used, which can decrease resistance and cause permanent deformations. OBJECTIVE: The objective of this study is to evaluate the influence of the diameter of Mini-Implants through bending force tests, taking into account primary stability after one and two insertions. METHODS: Here, 40 Ti6AI4V alloy Mini-Implants of two different brands and diameters were divided into eight groups, half of which received one insertion in the artificial bone, and the rest received two. All were subjected to a constant bending force using an INSTRON-Electropuls E10000LT (Norwood, MA, USA) until fracture. RESULTS: The smaller-diameter Mini-Implants were less resistant to fracture, but both were able to withstand the necessary loads produced by orthodontic movements. As for the inserts, there were no statistically significant differences. CONCLUSIONS: There is an advantage to using 1.6 mm Mini-Implants over 2.0 mm ones, as a smaller diameter does not lead to fracture due to the forces used in orthodontic treatment. Having one or two inserts did not have a statistically significant effect.

Hot Deformation Behavior of Free-Al 2.43 wt.% Si Electrical Steel Strip Produced by Twin-Roll Strip Casting and Its Effect on Microstructure and Texture.

Twin-roll strip casting (TRSC) technology has unique advantages in the production of non-oriented electrical steel. However, the hot deformation behavior of high-grade electrical steel produced by TRSC has hardly been reported. This work systematically studied the hot deformation behavior of free-Al 2.43 wt.% Si electrical steel strip produced by twin-roll strip casting. During the simulated hot rolling test, deformation reduction was set as 30%, and the ranges of deformation temperature and strain rate were 750~950 °C and 0.01~5 s-1, respectively. The obtained true stress-strain curves show that the peak true stress decreased with an increase in the deformation temperature and with a decrease in the strain rate. Then, the effect of hot deformation parameters on microstructure and texture was analyzed using optical microstructure observation, X-ray diffraction, and electron backscattered diffraction examination. In addition, based on the obtained true stress-strain curves of the strip cast during hot deformation, the constitutive equation for the studied silicon steel strip was established, from which it can be found that the deformation activation energy of the studied steel strip is 83.367 kJ/mol. Finally, the kinetics model of dynamic recrystallization for predicting the recrystallization volume percent was established and was verified by a hot rolling experiment conducted on a rolling mill.

Research on Hot Deformation Rheological Stress of Al-Mg-Si-Mn-Sc Aluminium Alloy.

The hot compression simulation testing machine was utilized to conduct compression experiments on an Al-Mg-Si-Mn alloy containing the rare earth element Sc at a deformation temperature ranging from 450 to 550 °C and a strain rate of 0.01 to 10 s-1. The study focused on the hot deformation behavior of the aluminum alloy, resulting in the determination of the optimal range of deformation process parameters for the alloy. The relationship between material flow stress, deformation temperature, and strain rate was described using the Arrhenius relationship containing thermal activation energy based on the stress-strain curve of hot compression deformation of aluminum alloy. This led to calculations for structural factor A, stress index n, and stress level parameters as well as thermal deformation activation energy to establish a constitutive Formula for hot deformation rheological stress of aluminum alloy and calculate the power dissipation factor η. Through this process, an optimized range for the optimal deformation process parameter for aluminum alloy was determined (deformation temperature: 490~510 °C; strain rate: 0.05 s-1) and verified in combination with mechanical properties and microstructure through hot extrusion deformation trial production.

Hot Deformation Constitutive Analysis and Processing Maps of Ultrasonic Melt Treated A5052 Alloy.

Hot deformation constitutive analysis and processing maps of ultrasonic melt treated (UST) A5052 alloy were carried out based on a hot torsion test in this study. The addition of the Al-Ti master alloy as a grain refiner with no UST produced a finer grain size than the UST and pure Ti sonotrode. The Al3Ti phase particles in the case of the Al-10Ti master alloy acted as a nucleus for grain refinement, while the Ti atoms dissolved in the melt from the sonotrode were considered to have less of a grain refinement effect, even under UST conditions, than the Al3Ti phase particles in the Al-Ti master alloy. The constitutive equations for each experimental condition by torsion test were derived. In the processing maps examined in this study, the flow instability region was not present under UST in the as-cast condition, but it existed under the no UST condition. The effects of UST examined in this study are considered as (i) the uniform distribution of Ti solutes from the sonotrode and (ii) the reduction of pores by the degassing effect. After the homogenization heat treatment, most instability regions disappeared because the microstructures became uniform following the decomposition of intermetallic compounds and distribution of solute elements.

Research on the Analysis of Residual Stress in Heat Treatment of Bellows Using ABAQUS.

Taking austenitic stainless-steel bellows as the research object, a finite element model for the heat treatment of austenitic stainless-steel bellows was constructed based on ABAQUS CAE 2022. The physical properties of the bellows after the heat treatment were analyzed using experimental and simulated curve processing analysis methods. The changes in residual stress and deformation in relation to the bellows under different cooling times were explored, as well as the distribution of residual stress and deformation at a certain cooling time. The results show that as the cooling time of the heat treatment increases, the residual stress of the bellow decreases significantly, the reduction rate accelerates, and the degree of deformation gradually decreases. When the cooling time of the heat treatment is 900 s, the residual stress of the wave peak in the middle position of the bellow is relatively small, and the residual stress value of the wave valley along the axis direction does not change significantly. The deformation degree of the wave peak and valley axis direction is relatively uniform.

Numerical Simulation of Electromagnetic-Thermal-Fluid Coupling for the Deformation Behavior of Titanium-Aluminum Alloy under Electromagnetic Levitation.

Electromagnetic levitation (EML) is a good method for high-temperature processing of reactive materials such as titanium-aluminum (Ti-Al) alloys. In this study, the oscillation and deformation processes of Ti-48Al-2Cr alloy specimens at different high-frequency currents during the EML process were simulated using the Finite Element Method and Arbitrary Lagrangian-Eulerian (ALE) methods. The data of oscillation, stabilization time, deformation, and distribution of electromagnetic-thermal-fluid fields were finally obtained. The accuracy of the simulation results was verified by EML experiments. The results show the following: the strength and distribution of the induced magnetic field inside the molten droplet are determined by the high-frequency current; under the coupling effect of the electromagnetic field, thermal field, and fluid field, the temperature rise of electromagnetic heating is rapid, and accompanied by strong stirring, resulting in a uniform distribution of the internal temperature and a small temperature difference. Under the joint action of gravity and Lorentz force, the molten droplets are first within a damped oscillation and then tend to stabilize with time, and finally maintain the "near rhombus" shape.

Identifying Optimal Processing Variables and Investigating Mechanisms of Grain Alignment in Hot-Deformed NdFeB Magnets through Design of Experiments.

This study introduces a novel approach for investigating hot-deformed NdFeB magnets by combining the minimal stress deformation process (MSDP) with the design of experiment (DoE) methodology. This study focused on enhancing the crystallographic alignment, particularly the c-axis alignment of the Nd2Fe14B grains, to optimize the magnetic properties. By utilizing the Box-Behnken design matrix and response surface regression, critical processes and variables were identified, determining that a hot-pressing temperature of 700 °C is crucial for achieving optimal grain alignment. Changing the strain rate to 0.019 mm/s under a stress of 110 MPa led to significant enhancements in the alignment, yielding magnets with a remanence of approximately 13.4 kG and a coercivity of 21 kOe. These findings highlight the effectiveness of combining the MSDP and DoE for predicting and achieving improved magnetic properties. Despite the challenges associated with understanding the complexity of crystal alignment mechanisms, this integrated approach successfully improved magnetic characteristics. The methodology represents a significant advancement in the fabrication of high-performance hot-deformed NdFeB magnets, marking a notable contribution to the field.

Prognostic value of myocardial deformation parameters for outcome prediction in tetralogy of Fallot.

INTRODUCTION: The prognostic value of myocardial deformation parameters in adults with repaired tetralogy of Fallot (rTOF) has not been well-elucidated. We therefore aimed to explore myocardial deformation parameters for outcome prediction in adults with rTOF using cardiovascular magnetic resonance imaging (CMR). METHODS: Adults with rTOF and at least moderate pulmonary regurgitation (PR) were identified from an institutional prospective CMR registry. Left (LV) and right ventricular (RV) global strain were recorded in longitudinal (GLS), circumferential (GCS) and radial (GRS) directions. Major adverse cardiovascular events (MACE) were defined as a composite of mortality, resuscitated sudden death, sustained ventricular tachycardia (>30seconds) or heart failure (hospital admission >24hours). In patients with pulmonary valve replacement (PVR), pre-and post-PVR CMR studies were analysed to assess for predictors of complete RV reverse remodelling, which we defined as RV end-diastolic volume indexed (RVEDVi) <110ml/m2. Logistic regression models were used to estimate the odds ratio (OR) per unit change in absolute strain value associated with clinical outcomes and receiver operator characteristic (ROC) curves were constructed with area under the curve (AUC) for select CMR variables. RESULTS: We included 307 patients (age 35±13 years, 59% male). During 6.1 years (3.3-8.8) of follow-up, pulmonary valve replacement (PVR) was performed in 142 (46%) and MACE occurred in 31 (10%). On univariate analysis, baseline biventricular ejection fraction (EF), mass and all strain parameters were associated with MACE. After adjustment for LVEF, only LVGLS remained independently predictive of MACE (OR 0.822 [0.693-0.976] p=0.025). Receiver operator curves identified an absolute LVGLS value less than 15 and LVEF <51% as thresholds for MACE prediction (AUC 0.759 [0.655-0.840] and 0.720 [0.608-0.810]). After adjusting for baseline RVEDVi, RVGCS (OR 1.323 [1.094-1.600] p=0.004), LVGCS (OR 1.276 [1.029-1.582] p=0.027) and LVGRS (OR 1.101 [1.0210-1.200], p=0.028) were independent predictors of complete remodelling post-PVR remodelling. CONCLUSIONS: Biventricular strain parameters predict clinical outcomes and post-PVR remodelling in rTOF. Further study will be necessary to establish the role of myocardial deformation parameters in clinical practice.

Real-time imaging of intracellular deformation dynamics in vibrated adherent cell cultures.

Mechanical vibration has been shown to regulate cell proliferation and differentiation in vitro and in vivo. However, the mechanism of its cellular mechanotransduction remains unclear. Although the measurement of intracellular deformation dynamics under mechanical vibration could reveal more detailed mechanisms, corroborating experimental evidence is lacking due to technical difficulties. In this study, we aimed to propose a real-time imaging method of intracellular structure deformation dynamics in vibrated adherent cell cultures and investigate whether organelles such as actin filaments connected to a nucleus and the nucleus itself show deformation under horizontal mechanical vibration. The proposed real-time imaging was achieved by conducting vibration isolation and making design improvements to the experimental setup; using a high-speed and high-sensitivity camera with a global shutter; and reducing image blur using a stroboscope technique. Using our system, we successfully produced the first experimental report on the existence of the deformation of organelles connected to a nucleus and the nucleus itself under horizontal mechanical vibration. Furthermore, the intracellular deformation difference between HeLa and MC3T3-E1 cells measured under horizontal mechanical vibration agrees with the prediction of their intracellular structure based on the mechanical vibration theory. These results provide new findings about the cellular mechanotransduction mechanism under mechanical vibration.

Distributed Vibration Monitoring System for 10 kV-400 kVA 3D Wound Core Transformer under Progressive Short-Circuit Impulses.

As large-scale, high-proportion, and efficient distribution transformers surge into the grids, anti-short circuit capability testing of transformer windings in efficient distribution seems necessary and prominent. To deeply explore the influence of progressively short-circuit shock impulses on the core winding deformation of efficient power transformers, a finite element theoretical model was built by referring to a three-phase three-winding 3D wound core transformer with a model of S20-MRL-400/10-NX2. The distributions of internal equivalent force and total deformation of the 3D wound core transformer along different paths under progressively short-circuit shock impulses varying from 60% to 120% were investigated. Results show that the equivalent stress and total deformation change rate reach their maximum as the short-circuit current increases from 60% to 80%, and the maximum and average variation rate for the equivalent stress reach 177.75% and 177.43%, while the maximum and average variation rate for the total deformation corresponds to 178.30% and 177.45%, respectively. Meanwhile, the maximum equivalent stress and maximum total deformation reach 29.81 MPa and 38.70 µm, respectively, as the applied short-circuit current increased to 120%. In light of the above observations, the optimization and deployment of wireless sensor nodes was suggested. Therefore, a distributed monitoring system was developed for acquiring the vibration status of the windings in a 3D wound core transformer, which is a beneficial supplement to the traditional short-circuit reactance detection methods for an efficient grid access spot-check of distribution transformers.

A Review of Subsidence Monitoring Techniques in Offshore Environments.

In view of the ever-increasing global energy demands and the imperative for sustainability in extraction methods, this article surveys subsidence monitoring systems applied to oil and gas fields located in offshore areas. Subsidence is an issue that can harm infrastructure, whether onshore or especially offshore, so it must be carefully monitored to ensure safety and prevent potential environmental damage. A comprehensive review of major monitoring technologies used offshore is still lacking; here, we address this gap by evaluating several techniques, including InSAR, GNSSs, hydrostatic leveling, and fiber optic cables, among others. Their accuracy, applicability, and limitations within offshore operations have also been assessed. Based on an extensive literature review of more than 60 published papers and technical reports, we have found that no single method works best for all settings; instead, a combination of different monitoring approaches is more likely to provide a reliable subsidence assessment. We also present selected case histories to document the results achieved using integrated monitoring studies. With the emerging offshore energy industry, combining GNSSs, InSAR, and other subsidence monitoring technologies offers a pathway to achieving precision in the assessment of offshore infrastructural stability, thus underpinning the sustainability and safety of offshore oil and gas operations. Reliable and comprehensive subsidence monitoring systems are essential for safety, to protect the environment, and ensure the sustainable exploitation of hydrocarbon resources.

Study on the size effect of rock burst tendency of red sandstone under uniaxial compression.

The study of rock burst tendency of rock masses with different sizes plays a key role in the prevention of rock burst. Through theoretical analysis, it is proposed that uniaxial compressive strength and deformation modulus ratio are the key mechanical parameters affecting rock burst occurrence. In order to find out the size effect of uniaxial compressive strength and deformation modulus ratio, theoretical analysis and uniaxial compression experiment are carried out on rock samples with different heights, different cross-sectional areas and different volumes. The results show that the smaller the uniaxial compressive strength is, the larger the deformation modulus ratio is, and the more likely rock burst are to occur. On the contrary, rock burst is still not easy to generate. The uniaxial compressive strength of rock samples with different heights, different cross-sectional areas and different volumes increases with the increase of rock sample size. The deformation modulus ratio of rock samples with different heights and different volumes shows an upward trend on the whole, while that of rock samples with different cross-sectional areas shows a downward trend on the whole. The fracture forms of rock are analyzed using the energy conversion law in the process of deformation and failure for three kinds of rock with different shapes and sizes.

The 3-year follow-up of a fully biodegradable implantable device closure for perimembranous ventricular septal defects in children using echocardiography.

Objects: The aim of this study was to investigate the morphologic changes of a novel fully biodegradable implantable device after closing a perimembranous ventricular septal defect (Pm-VSD) and to evaluate the effect of the occluder on the myocardial function in patients during a 3-year follow-up period. Methods: One-year, 2-year, and 3-year follow-ups were carried out after implantation with a total of 30 Pm-VSD patients who had successful closure by the fully biodegradable occluder. In total, 30 healthy children were enrolled as controls. At discharge and at every follow-up visit, the lengths of the left and right discs of the novel device were measured in the apical three- and four-chamber as well as short-axis views. At the end of the follow-up, using three-dimensional speckle-tracking conditions, the values of myocardial deformation, including global longitudinal strain, global circumferential strain, and global area strain, were acquired. Results: The fully bioabsorbable double-disc occluder gradually decreased over time and was eventually invisible under echocardiographic scanning during the follow-up (p < 0.05). At the end of the third year, there were no significant differences in the myocardial deformation parameters between the cases implanted with the novel devices and the controls; no significant differences were found between the basal segments of the ventricle septa and that of the left ventricle (LV) free wall among the patients who completed the Pm-VSD closure using the fully biodegradable occluder (p > 0.05). Conclusion: The novel fully biodegradable occluder is a safe, effective, and perfect alternative for the treatment of VSD. Echocardiography plays a crucial role in the follow-up of this new type of occluder implantation.

Multimaterial Metamaterials: Customize Targeted Thermal Deformation Modes Responding to Time- and Space-Variant Temperature Stimuli.

Customizing the engineering targeted thermal deformations is of vital significance for dimensional stability or shape morphing in materials and structures. However, current metamaterials are designed solely in the homogeneous form to respond only to the time-variant temperature (TVT) stimuli, far behind the practical engineering scenario and demands. Here, a new strategy is originally proposed and experimentally verified to design a series of both homogeneous and inhomogeneous multimaterial metamaterials, which uniquely output various thermal deformation modes, responding to time-variant and space-variant temperature (SVT) stimuli. Specifically, in addition to the regular isotropic thermal deformations, the metamaterials could exclusively output the entirely different positive and negative thermal deformations along the two orthotropic directions. Besides, stimulated by both TVT and SVT, the metamaterials provide more flexibility to customize the targeted thermal deformations. That is, the uniform thermal deformations could be well customized by the metamaterials stimulated by either TVT or SVT. More importantly, the customizability is remarkably broadened, as the nonuniform, specifically, mathematicized linear and nonlinear thermal deformations, are elaborately customized. Overall, these originally devised metamaterials open a new avenue for the purpose of customizing the engineering targeted thermal deformations in various modes under both TVT and SVT stimuli.