Design and Experimental Verification of Robust Motion Synchronization Control with Integral Action

A robust attitude motion synchronization problem is investigated for multiple 3-degrees-of-freedom (3-DOF) helicopters with input disturbances. The communication topology among the helicopters is modeled by a directed graph, and each helicopter can only access the angular position measurements of itself and its neighbors. The desired trajectories are generated online and not accessible to all helicopters. The problem is solved by embedding in each helicopter some finite-time convergent (FTC) estimators and a distributed controller with integral action. The FTC estimators generate the estimates of desired angular acceleration and the derivative of the local neighborhood synchronization errors. The distributed controller stabilizes the tracking errors and attenuates the effects of input disturbances. The conditions under which the tracking error of each helicopter converges asymptotically to zero are identified, and, for the cases with nonzero tracking errors, some inequalities are derived to show the relationship between the ultimate bounds of tracking errors and the design parameters. Simulation and experimental results are presented to demonstrate the performance of the controllers

Two Iterative algorithms for the matrix sign function based on the adaptive filtering technology

In this paper, two new efficient algorithms for calculating the sign function of the large-scale sparse matrix are proposed by combining filtering algorithm with Newton method and Newton Schultz method respectively. Through the theoretical analysis of the error diffusion in the iterative process, we designed an adaptive filtering threshold, which can ensure that the filtering has little impact on the iterative process and the calculation result. Numerical experiments are consistent with our theoretical analysis, which shows that the computational efficiency of our method is much better than that of Newton method and Newton Schultz method, and the computational error is of the same order of magnitude as that of the two methods.Comment: 18 pages,12 figure

A Fairness-Enhanced Federated Learning Scheduling Mechanism for UAV-Assisted Emergency Communication

As the frequency of natural disasters increases, the study of emergency communication becomes increasingly important. The use of federated learning (FL) in this scenario can facilitate communication collaboration between devices while protecting privacy, greatly improving system performance. Considering the complex geographic environment, the flexible mobility and large communication radius of unmanned aerial vehicles (UAVs) make them ideal auxiliary devices for wireless communication. Using the UAV as a mobile base station can better provide stable communication signals. However, the number of ground-based IoT terminals is large and closely distributed, so if all of them transmit data to the UAV, the UAV will not be able to take on all of the computation and communication tasks because of its limited energy. In addition, there is competition for spectrum resources among many terrestrial devices, and all devices transmitting data will bring about an extreme shortage of resources, which will lead to the degradation of model performance. This will bring indelible damage to the rescue of the disaster area and greatly threaten the life safety of the vulnerable and injured. Therefore, we use user scheduling to select some terrestrial devices to participate in the FL process. In order to avoid the resource waste generated by the terrestrial device resource prediction, we use the multi-armed bandit (MAB) algorithm for equipment evaluation. Considering the fairness issue of selection, we try to replace the single criterion with multiple criteria, using model freshness and energy consumption weighting as reward functions. The state of the art of our approach is demonstrated by simulations on the datasets

Enniatin B1 induces damage to Leydig cells via inhibition of the Nrf2/HO-1 and JAK/STAT3 signaling pathways

Enniatin B1 (ENN B1) is a mycotoxin that can be found in various foods. However, whether ENN B1 is hazardous to the reproductive system is still elusive. Leydig cells are testosterone-generating cells that reside in the interstitial compartment between seminiferous tubules. Dysfunction of Leydig cells could result in male infertility. This study aimed to examine the toxicological effects of ENN B1 against TM3 Leydig cells. ENN B1 significantly inhibited cell viability in a dose-dependent manner. ENN B1 treatment also decreased the expression of functional genes in Leydig cells. Moreover, ENN B1 induced Leydig cells apoptosis and oxidative stress. Mechanistically, ENN B1 leads to the upregulation of Bax and downregulation of Bcl-2 in Leydig cells. In addition, ENN B1 inhibited the Nrf2/HO-1 pathway, which is critical for the induction of oxidative stress. Additionally, ENN B1 treatment repressed the JAK/STAT3 signaling pathway in Leydig cells. Rescue experiments showed that activation of STAT3 resulted in alleviation of ENN B1-induced damage in Leydig cells. Collectively, our study demonstrated that ENN B1 induced Leydig cell dysfunction via multiple mechanisms

Exosomal miR-17-5p from human embryonic stem cells prevents pulmonary fibrosis by targeting thrombospondin-2

Abstract Background Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and irreversible lung disease characterized by pulmonary fibrosis and lung dysfunction, ultimately leading to respiratory failure. Many preclinical studies have investigated the therapeutic potential of stem cell-derived exosomes in this disease, particularly mesenchymal stem cell-derived exosomes. However, the effects of embryonic stem cell-derived exosomes in IPF remain unclear. Methods We established a bleomycin (BLM)-induced pulmonary fibrosis mice model and administered human embryonic stem cell exosomes (hESC-exo) from the first day after BLM treatment. The effects of hESC-exo were assessed by pulmonary function tests, biochemical analysis, histochemistry, quantitative real-time polymerase chain reaction (qPCR), and western blot (WB). RNA-seq was used to screen for the potential therapeutic targets of hESC-exo in fibrotic lungs; the identified signaling axis was characterized using a luciferase assay, qPCR, and WB. Results Results indicated hESC-exo administration notably alleviated inflammation, removed deposited collagen, and rescued alveolar architecture in the lungs of BLM-induced mice. In vivo and in vitro tests revealed that hESC-exo-derived miR-17-5p directly bound thrombospondin-2 (Thbs2) to regulate inflammation and fibrosis; thus, hESC-exo protected against BLM toxicity in the lungs via the miR-17-5p/Thbs2 axis. Conclusion These results suggest a promising new treatment for fibrosis-associated diseases

Rolling Circle Amplification (RCA)-Mediated Genome-Wide ihpRNAi Mutant Library Construction in Brassica napus

With the successful completion of genomic sequencing for Brassica napus, identification of novel genes, determination of functions performed by genes, and exploring the molecular mechanisms underlying important agronomic traits were challenged. Mutagenesis-based functional genomics techniques including chemical, physical, and insertional mutagenesis have been used successfully in the functional characterization of genes. However, these techniques had their disadvantages and inherent limitations for allopolyploid Brassica napus, which contained a large number of homologous and redundant genes. Long intron-spliced hairpin RNA (ihpRNA) constructs which contained inverted repeats of the target gene separated by an intron, had been shown to be very effective in triggering RNAi in plants. In the present study, the genome-wide long ihpRNA library of B. napus was constructed with the rolling circle amplification (RCA)-mediated technology. Using the phytoene desaturase (PDS) gene as a target control, it was shown that the RCA-mediated long ihpRNA construct was significantly effective in triggering gene silence in B. napus. Subsequently, the resultant long ihpRNA library was transformed into B. napus to produce corresponding RNAi mutants. Among the obtained transgenic ihpRNA population of B. napus, five ihpRNA lines with observable mutant phenotypes were acquired including alterations in the floral model and the stamen development. The target genes could be quickly identified using specific primers. These results showed that the RCA-mediated ihpRNA construction method was effective for the genome-wide long ihpRNA library of B. napus, therefore providing a platform for study of functional genomics in allopolyploid B. napus

High Precision Phase Noise Analysis Based on a Photonic-Assisted Microwave Phase Shifter Without Nonlinear Phase Distortion

We propose and demonstrate a high-precision phase noise analysis method based on a photonic-assisted microwave phase shifter (MPS) without nonlinear phase distortions (NPD). The proposed scheme utilizes a dual parallel Mach Zehnder modulator (DPMZM) and an optical bandpass filter (OBPF) to implement the photon-assisted microwave phase shifter. To avoid additional frequency noise induced by frequency fluctuations of the optical carrier, we employ a dispersion compensation photonic delay line as the delay line component. The MPS operates in the optical single sideband modulation (OSSB) mode with even-order sideband suppression, allowing continuous phase tuning over the entire $\mathbf { 360^{\circ }}$ range and eliminating NPD commonly encountered in traditional microwave photonic phase shifters. Experimental results demonstrate significant improvements in the phase and magnitude responses of the MPS without NPD compared to those with NPD. The proposed system exhibits long-term stability, with phase drift and amplitude drift of less than $\mathbf {5^{\circ }}$ and 1 dB, respectively, over continuous operation for more than 1500 seconds. We successfully measured microwave signals at the frequency of 8 GHz, 10 GHz, and 12 GHz with phase noise of $-$66.7, $-$65.5, and $-$62.1 dBc/Hz at 10 kHz offset frequency without resetting the proposed system. The method could be used to characterize electronic and photonic oscillators, which is highly reconfigurable and widely tunable

Endovascular treatment of acute basilar artery occlusion caused by vertebral artery stump syndrome: A clinical analysis of 37 cases

Introduction: Acute basilar artery occlusion (ABAO) caused by vertebral artery stump syndrome (VASS) has a low incidence and is always underestimated. Due to the occlusion of the origin of the vertebral artery (VA), it is often combined with basilar artery (BA) endovascular diseases or non-dominant contralateral vertebral artery, making the endovascular treatment (EVT) challenging to implement. Objective: This article focuses on whether EVT and two interventional route options could bring clinical benefits to this group of patients: basilar artery thrombectomy through the occluded lateral vertebral artery and implementing revascularization of the occluded vertebral artery (dirty-road-path); thrombectomy through the non-occluded lateral vertebral artery (clean-road-path). Methods: We collected six cases of acute embolic basilar artery occlusion (ABAO) due to VASS from January 2020 to December 2021 at our hospital and retrospectively analyzed 31 patients previously reported in the literature and applied statistical analysis to investigate the treatment options and clinical prognosis of these patients. Results: The clean-road-path surgical protocol was applied in 4 of 37 patients, the dirty-road-path protocol was applied in 29 patients, and 4 patients did not recanalized the basilar artery. By statistical analysis we found that successful recanalization of the basilar artery was clinically significant in reducing the modified Rankin Scale (mRS) scores in these patients, the statistical difference in the benefit of the two surgical protocols was negative. There was a significant positive correlation between preoperative National Institute of Health Stroke Scale (NIHSS) and postoperative 90-day mRS scores. Conclusion: Endovascular treatment can benefit patients with ABAO due to VASS, and patients with higher preoperative NIHSS scores are more vulnerable to getting a poor prognosis. Comparison between the two endovascular options did not yield statistically significant results, but the dirty-road-path option may be superior to using the clean-road-path

The occurrence and development mechanisms of esophageal stricture: state of the art review

Abstract Background Esophageal strictures significantly impair patient quality of life and present a therapeutic challenge, particularly due to the high recurrence post-ESD/EMR. Current treatments manage symptoms rather than addressing the disease's etiology. This review concentrates on the mechanisms of esophageal stricture formation and recurrence, seeking to highlight areas for potential therapeutic intervention. Methods A literature search was conducted through PUBMED using search terms: esophageal stricture, mucosal resection, submucosal dissection. Relevant articles were identified through manual review with reference lists reviewed for additional articles. Results Preclinical studies and data from animal studies suggest that the mechanisms that may lead to esophageal stricture include overdifferentiation of fibroblasts, inflammatory response that is not healed in time, impaired epithelial barrier function, and multimethod factors leading to it. Dysfunction of the epithelial barrier may be the initiating mechanism for esophageal stricture. Achieving perfect in-epithelialization by tissue-engineered fabrication of cell patches has been shown to be effective in the treatment and prevention of esophageal strictures. Conclusion The development of esophageal stricture involves three stages: structural damage to the esophageal epithelial barrier (EEB), chronic inflammation, and severe fibrosis, in which dysfunction or damage to the EEB is the initiating mechanism leading to esophageal stricture. Re-epithelialization is essential for the treatment and prevention of esophageal stricture. This information will help clinicians or scientists to develop effective techniques to treat esophageal stricture in the future