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In response to issues such as the unclear characteristics of isolation mechanisms, explosion-proof ability, high dynamic environmental response characteristics in MEMS safety systems, and insufficient design verification basis, the basic theory of the motion process of the explosion-proof mechanism was analyzed starting from the working principle of the explosion-proof mechanism. The explosion-proof performance and response characteristics of the explosion-proof mechanism under different preset conditions were studied through simulation calculation and experimental verification. The results show that when the thickness of the nickel material partition is less than 0.3 mm, it can block the high-speed impact of titanium flying plates with a design size of Φ 0.75 mm ×0.025 mm and the speed not exceeding 2,800 m/s; when the projectile speed is not less than 20,000 r/min, the isolation mechanism can move in place normally and lock successfully, while also having the ability to resist high overload impact. Under the action of not more than 50,000 g rear seat overload, the structure of the explosion-proof mechanism is intact without any failure.

The article deals with the issue of experimental research of the so-called design overloaded stage. A new experimental device enabling measurements on two-stage axial turbine is advantageously used in this research task. The experimental setup is designed so that a preparatory stage is included in front of the examined stage. The stage design introduces some aerodynamic overload already in the flow path design phase. This research program is focused primarily on the effect of leakage flows and their mixing with the mainstream. This paper describes the verification measurements on a newly introduced two-stage arrangement and reveals the first data obtained.

This paper presents a novel diamond honeycomb-like MEMS disk resonant gyroscope and the mode matching design method for it. By altering the width of the folded beams, the gyroscope’s frequency can be adjusted to 30 kHz, which make it can withstand extremely high overload. Aiming to improve its performance, this paper proposed a method to realise mode matching by adjusting the drive or sense axis beam width. This research lays the foundation for the performance improvement of the diamond honeycomb high-overload MEMS gyroscope.

Regarding the mechanical response of the electromechanical system during the penetration of an unpowered aircraft into water, dynamic simulation software was used to numerically simulate the mechanical characteristics of the electromechanical system during the penetration of a certain unpowered aircraft into water at different landing speeds. A comparative analysis was conducted on the overload of the electromechanical system when different buffering materials were used between the electromechanical system and the aircraft. The numerical simulation results showed that when the aircraft penetrated water at different speeds and an angle of 90°, the overload value was small, and the buffering effect of the buffering material on the electromechanical system was not significant. However, due to the presence of the front wing and tail wing, the overload value of the electromechanical system showed three peaks, especially when the speed was high. After the tail wing is damaged, the overload peak of the electromechanical system might not be synchronized with the peak of the aircraft, which may have a certain impact on whether the electromechanical system can work reliably. The results of the analysis can provide some references for the design of the reliable operation of the electromechanical system of unpowered aircraft.

Cell death maintains cell morphology and homeostasis during development by removing damaged or obsolete cells. The concentration of metal ions whithin cells is regulated by various intracellular transporters and repositories to maintain dynamic balance. External or internal stimuli might increase the concentration of metal ions, which results in ions overloading. Abnormal accumulation of large amounts of metal ions can lead to disruption of various signaling in the cell, which in turn can produce toxic effects and lead to the occurrence of different types of cell deaths. In order to further study the occurrence and development of metal ions overloading induced cell death, this paper reviewed the regulation of Ca2+, Fe3+, Cu2+ and Zn2+ metal ions, and the internal mechanism of cell death induced by overloading. Furthermore, we found that different metal ions possess a synergistic and competitive relationship in the regulation of cell death. And the enhanced level of oxidative stress was present in all the processes of cell death due to metal ions overloading, which possibly due to the combination of factors. Therefore, this review offers a theoretical foundation for the investigation of the toxic effects of metal ions, and presents innovative insights for targeted regulation and therapeutic intervention.Highlights• Metal ions overloading disrupts homeostasis, which in turn affects the regulation of cell death.• Metal ions overloading can cause cell death via reactive oxygen species (ROS).• Different metal ions have synergistic and competitive relationships for regulating cell death.

A scheme is proposed to use a Railway Static Power Conditioner (RPC) to dynamically balance phase-to-phase active power and reduce the overload frequency of traction transformers in response to frequent overload alarms and trips in some substations of the Lanxin Line. Firstly, on-site research on the daily load situation and overload situation of a V/v connection traction substation on the Lanxin Line was conducted in the past two years, using Origin to process the collected data and obtain the distribution patterns of power, voltage, etc., in the substation; Secondly, a control strategy and simulation model for RPC under extreme load current flow in the power supply arm are proposed in MATLAB/Simulink. The response effect and self-characteristics of parallel RPC under different load changes are simulated. Based on the assessment criteria of whether the transformer has experienced overload, simulation results show that after the RPC is put into operation, the three-phase grid side current is balanced, and under the same load conditions, the overload alarm and trip frequency are significantly reduced. The simulation results have verified that the installation of RPC can achieve power balance between phases on the feeder side, effectively improve the three-phase power quality on the grid side, reduce the overload of traction transformers, and improve the utilization rate of existing traction transformers.

Choice overload - in which larger choice sets are detrimental to a chooser's well-being - is potentially of great importance in the design of economic policy. Yet the current evidence on its prevalence is inconclusive. We argue that existing tests are likely to be underpowered and hence that choice overload may occur more often than the literature suggests. We propose more powerful tests based on richer data and characterization theorems for the Random Utility Model. These new approaches come with significant econometric challenges, which we show how to address. We apply our tests to new experimental data and find strong evidence of choice overload that would likely be missed using current approaches.

Mitochondria take up Ca 2+ through the mitochondrial calcium uniporter complex to regulate energy production, cytosolic Ca 2+ signalling and cell death 1 , 2 . In mammals, the uniporter complex (uniplex) contains four core components: the pore-forming MCU protein, the gatekeepers MICU1 and MICU2, and an auxiliary subunit, EMRE, essential for Ca 2+ transport 3 – 8 . To prevent detrimental Ca 2+ overload, the activity of MCU must be tightly regulated by MICUs, which sense changes in cytosolic Ca 2+ concentrations to switch MCU on and off 9 , 10 . Here we report cryo-electron microscopic structures of the human mitochondrial calcium uniporter holocomplex in inhibited and Ca 2+ -activated states. These structures define the architecture of this multicomponent Ca 2+ -uptake machinery and reveal the gating mechanism by which MICUs control uniporter activity. Our work provides a framework for understanding regulated Ca 2+ uptake in mitochondria, and could suggest ways of modulating uniporter activity to treat diseases related to mitochondrial Ca 2+ overload. Cryo-electron microscopy reveals the structures of the mitochondrial calcium uniporter holocomplex in low- and high-calcium conditions, showing the gating mechanism that underlies uniporter activation in response to intracellular calcium signals.

Background Burnout has risen across healthcare workers during the pandemic, contributing to workforce turnover. While prior literature has largely focused on physicians and nurses, there is a need to better characterize and identify actionable predictors of burnout and work intentions across healthcare role types. Objective To characterize the association of work overload with rates of burnout and intent to leave (ITL) the job in a large national sample of healthcare workers. Design Cross-sectional survey study conducted between April and December 2020. Setting A total of 206 large healthcare organizations. Participants Physicians, nurses, other clinical staff, and non-clinical staff. Measures Work overload, burnout, and ITL. Results The sample of 43,026 respondents (mean response rate 44%) was comprised of 35.2% physicians, 25.7% nurses, 13.3% other clinical staff, and 25.8% non-clinical staff. The overall burnout rate was 49.9% (56.0% in nursing, 54.1% in other clinical staff, 47.3% in physicians, and 45.6% in non-clinical staff; p  < 0.001 for difference). ITL was reported by 28.7% of healthcare workers, with nurses most likely to report ITL (41.0%), followed by non-clinical staff (32.6%), other clinical staff (32.1%), and physicians (24.3%) ( p  < 0.001 for difference). The prevalence of perceived work overload ranged from 37.1% among physicians to 47.4% in other clinical staff. In propensity-weighted models, work overload was significantly associated with burnout (adjusted risk ratio (ARR) 2.21 to 2.90) and intent to leave (ARR 1.73 to 2.10) across role types. Limitations Organizations’ participation in the survey was voluntary. Conclusions There are high rates of burnout and intent to leave the job across healthcare roles. Proactively addressing work overload across multiple role types may help with concerning trends across the healthcare workforce. This will require a more granular understanding of sources of work overload across different role types, and a commitment to matching work demands to capacity for all healthcare workers.

Iron dysregulation has been implicated in multiple neurodegenerative diseases, including Parkinson’s disease (PD). Iron-loaded microglia are frequently found in affected brain regions, but how iron accumulation influences microglia physiology and contributes to neurodegeneration is poorly understood. Here we show that human induced pluripotent stem cell-derived microglia grown in a tri-culture system are highly responsive to iron and susceptible to ferroptosis, an iron-dependent form of cell death. Furthermore, iron overload causes a marked shift in the microglial transcriptional state that overlaps with a transcriptomic signature found in PD postmortem brain microglia. Our data also show that this microglial response contributes to neurodegeneration, as removal of microglia from the tri-culture system substantially delayed iron-induced neurotoxicity. To elucidate the mechanisms regulating iron response in microglia, we performed a genome-wide CRISPR screen and identified novel regulators of ferroptosis, including the vesicle trafficking gene SEC24B . These data suggest a critical role for microglia iron overload and ferroptosis in neurodegeneration. Iron-laden microglia assume a disease-relevant, ferroptosis-associated signature and cause neurotoxicity. CRISPR screen uncovered regulators of ferroptosis in microglia. This ferroptosis–microglia–neurodegeneration axis could be targeted therapeutically.