Some sufficient conditions, which are valid for stability check of fractional-order nonlinear systems, are given in this paper. Based on these results, the synchronization of two fractional-order ...chaotic systems is investigated. A novel fractional-order sliding surface, which is composed of a synchronization error and its fractional-order integral, is introduced. The asymptotical stability of the synchronization error dynamical system can be guaranteed by the proposed fractional-order sliding mode controller. Finally, two numerical examples are given to show the feasibility of the proposed methods.
Due to the double-salient structure of the switched reluctance motor (SRM) and highly magnetic saturation, its rotor position shows highly nonlinear function with phase current and flux linkage. ...Therefore, the establishment of accurate and small-scale SRM rotor position model is crucial to realize SRM position sensorless control. This paper is based on SRM flux characteristics collected by actual measurement, then adopts back-propagation neural network (BPNN) with improved algorithm and radial basis function neural network (RBFNN), respectively, to build SRM rotor position model. It is concluded that the model built by BPNN based on the Levenberg-Marquardt algorithm has smaller network structure and higher accuracy than RBFNN. In order to optimize BPNN model further, two kinds of pretreatment methods are used to study SRM rotor position model, respectively, and the modeling results of these two methods are compared. Adopting pretreatment method could reduce scale and improve accuracy to achieve the model optimization. After initial rotor position was estimated accurately without rotor position sensor, experiments are performed based on a three-phase 12/8 SRM. The experimental results verify that the BPNN model of rotor position for SRM based on a pretreatment method could be applied to SRM position sensorless control.
Fractured porous media exist widely in reservoir rocks and fractures play a critical role in fluid flow processes. High resolution direct numerical simulations of fluid flow can provide important ...insight into pore‐scale processes and flow mechanisms in fractured permeable media, however, the tremendous computational costs prevent these methods from being applied into larger scale models. Pore network modeling is an alternative solution to this problem, but currently it can only be used in porous media without fractures. This work is concerned with incorporating discrete fractures into pore network modeling to represent fractured porous media. A new fracture matrix pore network model (FM‐PNM) is developed to efficiently simulate the fluid flow properties in fractures associated with the pore matrix. Discrete fractures are transformed into a fracture pipe network and integrated with the pore matrix that is represented by a network of pore bodies and pore throats. These two networks are coupled together to create a single nested network which is topologically equivalent to the fractured porous medium. This method extends the scope of applications of pore network modeling to fractured porous media. The permeability of the coupled network (FM‐PNM) is benchmarked by Lattice Boltzmann simulation for various structures of pore matrix and discrete fracture networks.
Key Points
A novel method (FM‐PNM) is developed to incorporate discrete fractures into pore networks in both 2D and 3D models
This method is able to efficiently simulate fluid flow properties in fractured porous media
This method extends the scope of applications of pore network model to fractured porous media
Landslide displacement prediction is a challenging research task that can help to reduce the occurrence of landslide disasters. The frequent occurrence of extreme weather increases the probability of ...landslides, and the subsequent increase in the superimposed economic development level exacerbates disaster losses, emphasizing the importance of landslide prediction. The collection of landslide monitoring data is the foundation of landslide displacement prediction, but the lack of various data severely limits the effectiveness of the landslide monitoring system. To address the issue of missing data during the landslide monitoring process, this paper proposes a time series prediction model of landslide displacement using mean-based low-rank autoregressive tensor completion (MLATC). Firstly, the reasons for the missing data of landslide displacement are analyzed, and the corresponding dataset of missing data is designed. Then, according to the characteristics and internal correlation of landslide displacement monitoring data, the establishment process of mean-based low-rank tensor completion prediction model is introduced. Finally, the proposed method is used to complete and predict the missing data for the random missing and non-random missing landslide displacement. The results show that the data completion and prediction results of the model are essentially consistent with the original displacement monitoring data of the landslide, and the accuracy and precision are relatively high. It shows that the model has good landslide displacement completion and prediction effects, which can provide a certain reference value for the missing data processing and landslide displacement prediction.
Recent evidence suggests that the box H/ACA small nucleolar RNA (snoRNA)-ended long noncoding RNA (lncRNA), SLERT, plays a critical role in gene regulation. However, its role in cancer remains ...undetermined. Herein, we explored its implication in human endometrial cancer (EC).
EC plasma and tissue samples were collected for the detection of SLERT expression using qRT-PCR method. The functional investigation was tested by CCK-8 and transwell assays. Luciferase reporter, RNA pull-down, and immunoprecipitation (RIP) assays were used to determine the regulatory network involved in SLERT. The in vivo effect of SLERT was tested by caudal vein lung metastasis model.
Stable knockdown of SLERT significantly inhibited EC cell (KLE and AN3CA) migration and invasion, while it did not affect cell viability. SLERT induced epithelial-mesenchymal transition (EMT) via elevating N-cadherin and Vimentin and downregulating E-cadherin. Further investigation showed that SLERT directly binds to METTL3, increasing the m
A levels of BDNF mRNA; then, the m
A sites were read by IGF2BP1, enhancing BDNF mRNA stability, followed by the activation of BDNF/TRKB signaling, an inducer of EMT. The animal model showed that overexpression of SLERT increased EC cell lung metastasis, and this effect was effectively blocked by BDNF silencing or treatment with TRKB inhibitor k252a. Clinically, EC patients have high levels of SLERT both in tissue or plasma, which might be used as a biomarker of diagnosis and prognosis.
Our findings, for the first time, uncover the metastasis-promoting effect of SLERT in EC via in vitro and in vivo evidence, providing a potential therapeutic target for metastatic EC treatment.
Objective Gasserian ganglion stimulation (GGS) is a neuromodulation technique that has been extensively applied in treating postherpetic trigeminal neuralgia. However, permanent implantation of GGS ...was preferred in most treatment approaches. Few studies have investigated temporary GGS for the treatment of acute/subacute herpetic trigeminal neuralgia. Moreover, previous research has reported lead dislocation when utilizing traditional electrodes, which was associated with poor pain relief. In GGS research, preventing the accidental displacement of lead following implantation has consistently been a primary objective. Methods We report a case of a 70-year-old woman with subacute herpetic trigeminal neuralgia who underwent temporary GGS for 14 days utilizing a sacral neuromodulation (SNM) quadripolar-tined lead. Computed tomography-guided percutaneous foramen ovale (FO) puncture and temporary SNM electrode implantation were performed during the surgery. A telephone interview was conducted to record a 12-month follow-up. Results At admission, zoster-related trigeminal pain severity was assessed to be 9/10 on the visual analog scale (VAS). After a 14-day GGS treatment, the pain assessed on the VAS score reduced to 1/10 at discharge but increased to 4/10 at the 12-month follow-up after surgery. Additionally, the anxiety level improved from 58 points to 35 points on the Self-Rating Anxiety Scale (SAS), and the depression level improved from 62 points to 40 points on the Self-Rating Depression Scale (SDS). The Physical Component Summary score of the 12-item Short-Form Health Survey (SF-12) increased from 33.9 to 47.0, and the Mental Component Summary (MCS) score of the SF-12 increased from 27.4 to 41.9. Conclusion Temporary GGS might be a potentially effective treatment for subacute herpetic trigeminal neuralgia, and an SNM electrode might be a good choice for reducing the risk of dislocation.
Although several artificial nanotherapeutics have been approved for practical treatment of metastatic breast cancer, their inefficient therapeutic outcomes, serious adverse effects, and high cost of ...mass production remain crucial challenges. Herein, we developed an alternative strategy to specifically trigger apoptosis of breast tumors and inhibit their lung metastasis by using natural nanovehicles from tea flowers (TFENs). These nanovehicles had desirable particle sizes (131 nm), exosome-like morphology, and negative zeta potentials. Furthermore, TFENs were found to contain large amounts of polyphenols, flavonoids, functional proteins, and lipids. Cell experiments revealed that TFENs showed strong cytotoxicities against cancer cells due to the stimulation of reactive oxygen species (ROS) amplification. The increased intracellular ROS amounts could not only trigger mitochondrial damage, but also arrest cell cycle, resulting in the in vitro anti-proliferation, anti-migration, and anti-invasion activities against breast cancer cells. Further mice investigations demonstrated that TFENs after intravenous (i.v.) injection or oral administration could accumulate in breast tumors and lung metastatic sites, inhibit the growth and metastasis of breast cancer, and modulate gut microbiota. This study brings new insights to the green production of natural exosome-like nanoplatform for the inhibition of breast cancer and its lung metastasis via i.v. and oral routes.
Exosome-like nanovesicles from edible tea flowers induced mitochondrial damage, cell cycle arrest, cell apoptosis, microbiota modulation, and further inhibited the growth of breast tumors and their lung metastasis. Display omitted
Adult
Malpighian tubules have low rates of cell turnover but are vulnerable to damage caused by stones, like their mammalian counterparts, kidneys. We show that
renal stem cells (RSCs) in the ureter ...and lower tubules comprise a unique, unipotent regenerative compartment. RSCs respond only to loss of nearby principal cells (PCs), cells critical for maintaining ionic balance. Large polyploid PCs are outnumbered by RSCs, which replace each lost cell with multiple PCs of lower ploidy. Notably, RSCs do not replenish principal cells or stellate cells in the upper tubules. RSCs generate daughters by asymmetric Notch signaling, yet RSCs remain quiescent (cell cycle-arrested) without damage. Nevertheless, the capacity for RSC-mediated repair extends the lifespan of flies carrying kidney stones. We propose that abundant, RSC-like stem cells exist in other tissues with low rates of turnover where they may have been mistaken for differentiated tissue cells.
According to the characteristics of the geological environment and disasters, this paper uses microelectronics, wireless communication, thin-film solar power supply and other technologies, combined ...with lightweight process design, a new scheme for rapid geological disaster monitoring system based on LoRa is proposed. The system is based on embedded microprocessor of STM32F103 and SX1278 module of LoRa, which uses self-organizing network design of star-type and constructs a monitoring system with long communication distance and stable and reliable data transmission. The system can realize real-time data collection of multiple monitoring parameters of the disaster body and transmit the monitoring data to the data center or dedicated data receiving terminal through LoRa/GPRS/BeiDou satellite, which can provide data support for expert analysis and decision-making. The system has the features of low power consumption, long transmission distance, ad hoc network, stable and reliable communication, which has wide application prospect in the field of geological disaster monitoring.
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