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A study on the load characteristics of the modified gear planetary gear systems is conducted to address the issue of uneven loads between planetary gears due to manufacturing and installation errors, which result in deviations between the radial and circumferential installation positions of planetary gears and non-offset values. Based on the theory of rotor dynamics, the time-varying stiffness and the radial and circumferential offsets of the planetary gears are considered, and the five-degree-of-freedom dynamic model of the planetary gear transmission system with addendum modification is established. The response and frequency spectrum of the system are solved by the Runge-Kutta method. The load distribution characteristics of the planet gears under different radial offsets, circumferential offsets, and comprehensive offsets are analyzed. The influence of the radial and circumferential offset of the planetary gear on the load distribution of the planetary gear transmission system is discussed, and the variation law of the load vibration amplitude of the planetary gear transmission system with addendum modification under the time and frequency is obtained. The simulation results show that the load characteristics of the planetary gear train considering the error are quite different from those in theory. Its vibration amplitude of the planetary gear transmission system is greatly affected by the radial offset, and the large radial offset has the greatest impact on the load of the planetary gear. Small deflections of the planetary gear during installation can lead to large changes in the load characteristics. The planetary gear transmission system load test platform is built, the frequency-doubling vibration response signal of the planetary reducer housing is tested, and the relation between the planetary gear transmission system load force and vibration response is obtained. The amplitude variation trend in the experimental results is similar to that in the simulation analysis, and the correctness of the established model and solution method is verified.

Strain measurements are vital for monitoring the load-bearing capacity and safety of structures. A common approach is to affix strain gages onto structural surfaces. On the other hand, most aerospace, automotive, civil, and mechanical structures are painted and coated, often with many layers, prior to their deployment. There is an opportunity to design smart and multifunctional paints that can be directly pre-applied onto structural surfaces to serve as a sensing layer among their other layers of functional paints. Therefore, the objective of this study was to design a strain-sensitive paint that can be used for structural monitoring. Carbon nanotubes (CNT) were dispersed in paint by high-speed shear mixing, while paint thinner was employed for adjusting the formulation's viscosity and nanomaterial concentration. The study started with the design and fabrication of the CNT-based paint. Then, the nanocomposite paint's electromechanical properties and its sensitivity to applied strains were characterized. Third, the nanocomposite paint was spray-coated onto patterned substrates to form "Sensing Meshes" for distributed strain monitoring. An electrical resistance tomography (ERT) measurement strategy and algorithm were utilized for reconstructing the conductivity distribution of the Sensing Meshes, where the magnitude of conductivity (or resistivity) corresponded to the magnitude of strain, while strain directionality was determined based on the strut direction in the mesh.

Wearable sensors that measure parameters associated with physical activity and bodily motions have been regarded as an indispensable tool for assessing personal wellness. Recent advances in nanocomposite strain sensors have been successfully used for monitoring skin strains and other strain-derived physiological parameters. This study complements the existing body of work and presents a flexible, self-adhering, fabric-based wearable sensor for measuring skin strains and human motions. Graphene nanosheet thin films are directly spray-coated onto kinesiology tape (K-Tape) to obtain a self-adhering strain sensor of high sensitivity and linearity. Their stable sensing performance and high repeatability are verified, while human subject tests confirm that they adequately capture muscle engagement during functional movements. In addition, densely distributed strain monitoring can be achieved using an electrical impedance tomography measurement approach and algorithm. Spatial strain sensing is successfully demonstrated using a single strip of piezoresistive K-Tape, as well as when a K-Tape network or mesh pattern is formed. The results show promise for using graphene K-Tape meshes to measure how specific major muscle groups engage during different physical activities.

Mechanisms underlying motor neuron degeneration in amyotrophic lateral sclerosis (ALS) are yet unclear. Specific deletion of the ER-component membralin in astrocytes manifested postnatal motor defects and lethality in mice, causing the accumulation of extracellular glutamate through reducing the glutamate transporter EAAT2. Restoring EAAT2 levels in membralin KO astrocytes limited astrocyte-dependent excitotoxicity in motor neurons. Transcriptomic profiles from mouse astrocytic membralin KO motor cortex indicated significant perturbation in KEGG pathway components related to ALS, including downregulation of Eaat2 and upregulation of Tnfrsf1a. Changes in gene expression with membralin deletion also overlapped with mouse ALS models and reactive astrocytes. Our results shown that activation of TNF receptor (TNFR1)-NFκB pathway known to suppress Eaat2 transcription was upregulated with membralin deletion. Further, reduced membralin and EAAT2 levels correlated with disease progression in spinal cord from SOD1-mutant mouse models, and reductions in membralin/EAAT2 were observed in human ALS spinal cord. Importantly, overexpression of membralin in SOD1G93A astrocytes decreased TNFR1 levels and increased EAAT2 expression, and improved motor neuron survival. Importantly, upregulation of membralin in SOD1G93A mice significantly prolonged mouse survival. Together, our study provided a mechanism for ALS pathogenesis where membralin limited glutamatergic neurotoxicity, suggesting that modulating membralin had potentials in ALS therapy.

In this paper, we introduce an agent rescue scheduling approach grounded in proximal policy optimization, coupled with a singularity-free predefined-time control strategy. The primary objective of this methodology is to bolster the efficiency and precision of rescue missions. Firstly, we have designed an evaluation function closely related to the average flying distance of agents, which provides a quantitative benchmark for assessing different scheduling schemes and assists in optimizing the allocation of rescue resources. Secondly, we have developed a scheduling strategy optimization method using the Proximal Policy Optimization (PPO) algorithm. This method can automatically learn and adjust scheduling strategies to adapt to complex rescue environments and varying task demands. The evaluation function provides crucial feedback signals for the PPO algorithm, ensuring that the algorithm can precisely adjust the scheduling strategies to achieve optimal results. Thirdly, aiming to attain stability and precision in agent navigation to designated positions, we formulate a singularity-free predefined-time fuzzy adaptive tracking control strategy. This approach dynamically modulates control parameters in reaction to external disturbances and uncertainties, thus ensuring the precise arrival of agents at their destinations within the predefined time. Finally, to substantiate the validity of our proposed approach, we crafted a simulation environment in Python 3.7, engaging in a comparative analysis between the PPO and the other optimization method, Deep Q-network (DQN), utilizing the variation in reward values as the benchmark for evaluation. [ABSTRACT FROM AUTHOR]

Electric pylons are crucial components of power infrastructure, requiring accurate detection and identification for effective monitoring of transmission lines. This paper proposes an innovative model, the EP-YOLOv8 network, which incorporates new modules: the DSLSK-SPPF and EMS-Head. The DSLSK-SPPF module is designed to capture the surrounding features of electric pylons more effectively, enhancing the model's adaptability to the complex shapes of these structures. The EMS-Head module enhances the model's ability to capture fine details of electric pylons while maintaining a lightweight design. The EP-YOLOv8 network optimizes traditional YOLOv8n parameters, demonstrating a significant improvement in electric pylon detection accuracy with an average mAP@0.5 value of 95.5%. The effective detection of electric pylons by the EP-YOLOv8 demonstrates its ability to overcome the inefficiencies inherent in existing optical satellite image-based models, particularly those related to the unique characteristics of electric pylons. This improvement will significantly aid in monitoring the operational status and layout of power infrastructure, providing crucial insights for infrastructure management and maintenance. [ABSTRACT FROM AUTHOR]

Variants of TREM2 are associated with Alzheimer's disease (AD). To study whether increasing TREM2 gene dosage could modify the disease pathogenesis, we developed BAC transgenic mice expressing human TREM2 (BAC-TREM2) in microglia. We found that elevated TREM2 expression reduced amyloid burden in the 5xFAD mouse model. Transcriptomic profiling demonstrated that increasing TREM2 levels conferred a rescuing effect, which includes dampening the expression of multiple disease-associated microglial genes and augmenting downregulated neuronal genes. Interestingly, 5xFAD/BAC-TREM2 mice showed further upregulation of several reactive microglial genes linked to phagocytosis and negative regulation of immune cell activation. Moreover, these mice showed enhanced process ramification and phagocytic marker expression in plaque-associated microglia and reduced neuritic dystrophy. Finally, elevated TREM2 gene dosage led to improved memory performance in AD models. In summary, our study shows that a genomic transgene-driven increase in TREM2 expression reprograms microglia responsivity and ameliorates neuropathological and behavioral deficits in AD mouse models.

In the case of low content of heavy metals in soil, the hyperspectral characteristic response of heavy metals is very weak, so it is difficult to construct an accurate direct hyperspectral inversion model. In order to solve the above problems, according to the physical and chemical properties of soil chemical variables, the enrichment characteristics of heavy metals are transferred to the related major chemical elements, so that the weak information of heavy metals can be indirectly quantitatively inverted. In this paper, the black soil in Hailun was taken as the research object. Through principal component analysis and cluster analysis, it was confirmed that there was an obvious adsorption occurrence relationship between the major element iron oxide (Fe2O3) and trace heavy metals As, Zn, Cd. The best inversion model of iron oxide content in the study area was established by partial least square method (the determination coefficient is 0.704, the root mean square difference is 0.148, and the F-test is 12.732). Based on the occurrence relationship between iron oxide and As, Zn, CD, a nonlinear fitting model between the predicted value of iron oxide and the real value of heavy metals was constructed by neural network. The fitting results show that the fitting degree of As, Zn and Cd is As>Zn>Cd. The overall correlations are 0.796, 0.732, 0.530 respectively. The study results show that the indirect prediction model based on iron oxide content can better quantitatively predict As, Zn and Cd, which provides a new method for the quantitative analysis of trace heavy metal content. This model provides a basis for hyperspectral remote sensing technology to predict soil heavy metal content, enhances the feasibility of soil trace heavy metal inversion, and is helpful to refine the quality monitoring of natural resource. It is of great significance to deepen the comprehensive analysis and evaluation of geoscience system.

The concept of lightweight design is widely employed for designing and constructing aerospace structures that can sustain extreme loads while also being fuel-efficient. Popular lightweight materials such as aluminum alloy and fiber-reinforced polymers (FRPs) possess outstanding mechanical properties, but their structural integrity requires constant assessment to ensure structural safety. Next-generation structural health monitoring systems for aerospace structures should be lightweight and integrated with the structure itself. In this study, a multi-walled carbon nanotube (MWCNT)-based polymer paint was developed to detect distributed damage in lightweight structures. The thin film's electromechanical properties were characterized via cyclic loading tests. Moreover, the thin film's bulk conductivity was characterized by finite element modeling.

Progressive supranuclear palsy (PSP) is a movement disorder characterized by tau neuropathology where the underlying mechanism is unknown. An SNP (rs1768208 C/T) has been identified as a strong risk factor for PSP. Here, we identified a much higher T-allele occurrence and increased levels of the pro-apoptotic protein appoptosin in PSP patients. Elevations in appoptosin correlate with activated caspase-3 and caspase-cleaved tau levels. Appoptosin overexpression increased caspase-mediated tau cleavage, tau aggregation, and synaptic dysfunction, whereas appoptosin deficiency reduced tau cleavage and aggregation. Appoptosin transduction impaired multiple motor functions and exacerbated neuropathology in tau-transgenic mice in a manner dependent on caspase-3 and tau. Increased appoptosin and caspase-3-cleaved tau were also observed in brain samples of patients with Alzheimer's disease and frontotemporal dementia with tau inclusions. Our findings reveal a novel role for appoptosin in neurological disorders with tau neuropathology, linking caspase-3-mediated tau cleavage to synaptic dysfunction and behavioral/motor defects.

Down syndrome (DS), or trisomy 21, is one of the critical risk factors for early-onset Alzheimer's disease (AD), implicating key roles for chromosome 21-encoded genes in the pathogenesis of AD. We previously identified a role for the deubiquitinase USP25, encoded on chromosome 21, in regulating microglial homeostasis in the AD brain; however, whether USP25 affects amyloid pathology remains unknown. Here, by crossing 5*FAD AD and Dp16 DS mice, we observed that trisomy 21 exacerbated amyloid pathology in the 5*FAD brain. Moreover, bacterial artificial chromosome (BAC) transgene-mediated USP25 overexpression increased amyloid deposition in the 5*FAD mouse brain, whereas genetic deletion of Usp25 reduced amyloid deposition. Furthermore, our results demonstrate that USP25 promoted p cleavage of APP and Ap generation by reducing the ubiquitination and lysosomal degradation of both APP and BACE1. Importantly, pharmacological inhibition of USP25 ameliorated amyloid pathology in the 5*FAD mouse brain. In summary, we identified the DS-related gene USP25 as a critical regulator of AD pathology, and our data suggest that USP25 serves as a potential pharmacological target for AD drug development., Introduction Down syndrome (DS), the most common form of intellectual disability, arises from total or partial triplication of chromosome 21. As one of the critical risk factors for early-onset Alzheimer's [...]

Fiber-reinforced polymer composites are a popular alternative to traditional metal alloys. However, their internally occurring damage modes call for strategies to monitor these structures. Multi-walled carbon nanotube-based polyelectrolyte thin films were manufactured using a layer-by-layer deposition methodology. The thin films were applied directly to the surface of glass fiber-reinforced polymer composites, with the purpose of structural monitoring. This work focuses on characterizing the sensitivity of the electrical properties of the film using time- and frequency-domain methods under applied quasi-static and dynamic mechanical loading. In addition, environmental effects such as those of temperature and humidity are varied to characterize the sensitivity of the electrical properties to these phenomena. © 2013 IOP Publishing Ltd.