The dynamic uncertain environment and complex tasks determine that the unmanned aerial vehicle (UAV) system is bound to develop towards clustering, autonomy，and intelligence. In this paper, we present a comprehensive survey of UAV swarm intelligence from the hierarchical framework perspective. Firstly, we review the basics and advances of UAV swarm intelligent technology. Then we look inside to investigate the research work by classifying UAV swarm intelligence research into five layers, i.e., decision-making layer, path planning layer, control layer, communication layer, and application layer. Furthermore, the relationship between each level is explicitly illustrated, and the research trends of each layer are given. Finally, limitations and possible technology trends of swarm intelligence are also covered to enable further research interests. Through this in-depth literature review, we intend to provide novel insights into the latest technologies in UAV swarm intelligence.

Transcutaneous electrical acupoint stimulation (TEAS) is a form of acupuncture treatment that applies electrical stimulation on specific acupoint through cutaneous electrodes. This technique has been used for perioperative anesthesia management as part of after surgery recovery. However, to date, limited data are available for using the TEAS for postoperative recovery in elderly surgical patients. We conducted this prospective randomized sham-control trail to evaluate the efficacy of TEAS in a group of elderly patients receiving knee surgery under epidural anesthesia. 52 subjects were assigned to either the experimental group (Group E) or control group (Group C). The patients in Group E received TEAS at zusanli (ST36), sanyinjiao (SP6), neiguan (PC6), and quchi acupoints (LI11) 30[Formula: see text]min prior to the epidural anesthesia and postoperative day 1 and 2, while patients in Group C received sham TEAS on the same acupoints for 30[Formula: see text]min same as those of Group E. The primary endpoint was the Quality of Recovery-40 questionnaire (QR-40) and the secondary endpoints were the biomarkers level of stress and inflammatory responses and visual analogue scale (VAS). A one-way ANOVA (SNK method) was used in statistic, and [Formula: see text] is considered to be statistically significant. Our data showed that the QoR-40 was significantly lower in Group C than that in Group E at postoperative day 1 ([Formula: see text]); Similarly, Cortisol (COR), Adrenocorticotropic Hormone (ACTH), and C-reactive protein (CRP) were significantly lower in Group E than those of Group C at postoperative day 1, 3, and 7 ([Formula: see text]), while the neutrophil/lymphocyte ratio (N/L) was lower in Group E than that in Group C at postoperative day 1 and 3 ([Formula: see text]). Our results showed that perioperative TEAS administration is able to facilitate the development of postoperative recovery of elderly patients, especially at the early stage after surgery. The reported results are likely to be mediated by the reduction of surgical inflammation and perioperative stress response.

Purpose Traditional Chinese medicine (TCM) has gained increasing attention for the treatment of multiple chronic diseases, such as cancer. Here we aim to identify the antitumor activity of Sichong formula, a novel TCM, in human gastric cancer cells and investigate the underlying mechanisms. Methods The AGS and MKN45 gastric cancer cells were treated with Sichong formula at different concentrations. The proliferation rates were tested by CCK-8 and colony formation assays. Cell migration and invasion were tested by scratch and transwell assays. Gelatin zymography was used to detect the matrix metalloproteinase 9 (MMP9) activity in cell suspendents. Cell apoptosis was analyzed by Annexin V/PI staining and flow cytometry. The expression of interest proteins was tested by Western blot. Results Cell proliferation analysis indicated that Sichong formula inhibited cell viability of AGS and MKN45 cells in a dose- and time-dependent manner. The IC50 values were 240 μg/mL and 200 μg/mL for AGS and MKN45 cells, respectively. Furthermore, we found that Sichong formula could inhibit the invasion and migration of gastric cancer cells, which might be mediated by the downregulation of MMP9 activity. Flow cytometry results indicated that Sichong formula induced apoptosis in gastric cancer cells through upregulation of Bax/Bcl2 ratio and activation of caspase cascade. The results from Western blot indicated that Sichong formula resulted in cell autophagy and inactivation of AKT signaling pathway. Conclusion Our data suggest that Sichong formula inhibits the proliferation and migration and induces apoptosis in human gastric cancer cells. The inhibitory effect of Sichong formula was, at least partly, mediated by cell autophagy and AKT pathway.

Previous studies reported that Agrimonia pilosa (AP) Ledeb possessed diverse biological activities, including anti-inflammatory, antioxidant, and anti-tumor activities. However, the effect of AP on ulcerative colitis (UC) remains unclear. In this study, we investigated the therapeutic effect and mechanisms of AP on dextran sodium sulfate (DSS)-induced colitis. The potential constituents of AP were investigated by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). A total of 13 compounds were recognized by UPLC-Q-TOF/MS chromatogram. Furthermore, a network pharmacology approach revealed that there are 297 candidate targets of UC and 549 common targets for the 13 active ingredients of AP. GO enrichment and KEGG pathway analysis indicated that AP might have a protective effect on UC through the nuclear factor κB (NF-κB) and nucleotide-binding oligomerization domain (NOD)-like receptor signaling pathways. Subsequent experimental validation in a DSS-induced colitis model revealed that AP alleviated the severity of DSS-induced colitis, reduced the production of proinflammatory factors, and protected against the loss of intestinal integrity. Moreover, AP inhibited the phosphorylation of NF-κB p65 and the activation of the NLRP3 inflammasome. In conclusion, AP ameliorated DSS-induced colitis through suppressing the activation of the NLRP3 inflammasome and NF-κB signaling pathways.

No abstract

In system science, a swarm possesses certain characteristics which the isolated parts and the sum do not have. In order to explore emergence mechanism of a large–scale electromagnetic agents (EAs), a neighborhood selection (NS) strategy–based electromagnetic agent cellular automata (EA–CA) model is proposed in this paper. The model describes the process of agent state transition, in which a neighbor with the smallest state difference in each sector area is selected for state transition. Meanwhile, the evolution rules of the traditional CA are improved, and performance of different evolution strategies are compared. An application scenario in which the emergence of multi–jammers suppresses the radar radiation source is designed to demonstrate the effect of the EA–CA model. Experimental results show that the convergence speed of NS strategy is better than those of the traditional CA evolution rules, and the system achieves effective jamming with the target after emergence. It verifies the effectiveness and prospects of the proposed model in the application of electronic countermeasures (ECM).

The problem of passive localization using an unmanned aerial vehicle (UAV) swarm is studied. For multi-UAV localization systems with limited communication and observation range, the challenge is how to obtain accurate target state consistency estimates through local UAV communication. In this paper, an ant colony pheromone mechanism-based passive localization method using a UAV swarm is proposed. Different from traditional distributed fusion localization algorithms, the proposed method makes use of local interactions among individuals to process the observation data with UAVs, which greatly reduces the cost of the system. First, the UAVs that have detected the radiation source target estimate the rough target position based on the pseudo-linear estimation (PLE). Then, the ant colony pheromone mechanism is introduced to further improve localization accuracy. The ant colony pheromone mechanism consists of two stages: pheromone injection and pheromone transmission. In the pheromone injection mechanism, each UAV uses the maximum likelihood (ML) algorithm with the current observed target bearing information to correct the initial target position estimate. Then, the UAV swarm weights and fuses the target position information between individuals based on the pheromone transmission mechanism. Numerical results demonstrate that the accuracy of the proposed method is better than that of traditional localization algorithms and close to the Cramer–Rao lower bound (CRLB) for small measurement noise.

Background: Gastric cancer (GC) is the third most common cause of cancer-related death worldwide. Increasing studies have indicated that circular RNAs (circRNAs) play critical roles in cancer progression. However, the precise mechanism and functions of most circRNAs are still unknown in gastric cancer. Method: In the present study, we aim to uncover the mechanism by which circRNAs regulate gastric cancer tumorigenesis. By analyzing the microarray data, we screened differential expressed circRNAs in the gastric cancer group and identified a down-regulated circRNA, hsa_circ_0040039 (circSNTB2). Mechanically, circSNTB2 served as a sponge for the miR-6938-5p and up-regulated its expression. Result/Discussion: Meanwhile, G0/G1 switch gene 2 (G0S2) and programmed cell death gene 4 (PDCD4) were identified to be the aim genes of miR-6938-5p, con-structing circSNTB2/miR-6938-5p/G0S2 and PDCD4 pathways. Conclusion: Taken together, our findings demonstrated that circSNTB2 plays an es-sential role in gastric cancer by regulating miR-6938-5p through G0S2 and PDCD4 genes. CircSNTB2 could be a promising biomarker for GC diagnosis and targeted therapy.