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Relative measurements are exploited to cooperatively detect and recover faults in the positioning of Mobile Agent (MA) Swarms (MASs). First, a network vertex fault detection method based on edge testing is proposed. For each edge, a property that has a functional relationship with the properties of its two vertices is measured and tested. Based on the edge testing results of the network, the maximum likelihood principle is used to identify the vertex fault sources. Second, an edge distance testing method based on the noncentral chi-square distribution is developed for detecting faults in the Global Navigation Satellite System (GNSS) positioning of MASs. Third, a recovery strategy for faults in the positioning of MASs based on distance measurement is provided. The effectiveness of the proposed methods is validated by a simulation case in which an MAS passes through a GNSS spoofing zone. The proposed methods are conducive to increasing the robustness of the positioning of MASs in complex environments. The main novelties include the following: (A) network vertex fault detection is based on concrete probability analysis rather than simple majority voting, and (B) the relation of detectability and recoverability of MAS positioning faults with the structure of the relative measurement network is first disclosed.

This work mainly addresses the attitude tracking problem for rigid spacecraft subject to external disturbances, actuator saturation and faults. Firstly, a finite-time prescribed performance function (FTPPF) is defined to limit the tracking errors of original system into the boundary constraints and converge into a small residual set around zero within the preassigned time. An error transformation is employed to transform the constrained control system into an unconstraint one to simplify the relevant controller design. With the aid of the hyperbolic tangent function, the actuator saturation is approximated, and the approximation error is included into the external disturbances to be restrained. Then, a linear extended state observer (LESO) is developed to address the synthetic disturbances mentioned above with fewer tuning parameters. Wherein, the nominal matrix replaces the actual input gains is employed in the LESO design to avoid the singularity in disturbance rejection resulted from saturation approximation. Furthermore, an observer-based fault-tolerant tracking controller is derived to stabilize the attitude tracking error system and realize the disturbance compensation. Compared with the existing methods based on neutral networks (NNs) or fuzzy approximations, the developed scheme can achieve simultaneous estimations of multiple disturbances with simpler design. Meanwhile, the disadvantage that the NNs and fuzzy approximations are only effective on some compact sets is avoided. Finally, numerical simulations and analyses are employed to verify the superiority and robustness of the proposed method.

An event-driven neural network–based fault-tolerant tracking control scheme is investigated for uncertain mechanical systems with performance guaranteed in the presence of unknown actuator faults and external disturbances. Compared with the existing works, the primary advantage is that the detections and identifications of actuator faults are not required, whereas the convergence rate and tracking accuracy can be guaranteed a priori by constructing an adaptive tracking controller with a few aperiodic updates. Moreover, by using the norm-bounding skill, only two adaptive parameters are needed to update online, which dramatically decreases the complexity of the corresponding adaptive schemes. Finally, applications to the attitude stabilization and tracking control of the flexible spacecraft are used to validate the effectiveness of the proposed control scheme.

Inadequate immune response remains a critical cause of immunotherapy failure in various tumor treatments. Herein, we offer a new approach to achieve a cross-talk between innate and adaptive immune responses based on a new nanoplatform for photothermal therapeutics. The nanoplatform was formed by linking titanium carbide MXene with Mn

This paper investigates a novel finite-time saturated deployment control approach for the tethered satellite system in the presence of uncertain dynamics and space perturbations, as well as state constraints. First, an integral Lyapunov function is constructed to remove the hard state constraints characterized by a finite-time convergent performance function. Then, a backstepping finite-time deployment controller is devised via using an extended state observer (ESO) to approach the unknown dynamics, perturbations and saturation deviation. Compared with the existing finite-time control methods, the prominent advantage of the proposed one is that the finite-time saturated deployment control is achieved without violating the state constraints and using fractional state feedback. Finally, an illustrative example is organized to validate the effectiveness of the proposed approach.

With consideration of motion control performance and efficient information communication, the synchronization problem on communication connectivity preservation and guaranteed consensus performance for networked mechanical systems has attracted considerable attention in recent years. Different from the existing works, this article investigates a brand-new appointed-time consensus control approach for uncertain networked Euler-Lagrange systems on a directed graph via exploring the prescribed performance control structure. First, a two-layer prescribed performance envelope is formulated via using an appointed-time convergent function for position-related and velocity-related consensus errors, respectively. Then, a simple state-feedback virtual controller with online adaptive performance adjustment is developed to preserve the communication connectivity. Moreover, to guarantee the velocity consensus of the networked systems and improve the position consensus accuracy, an appointed-time adaptive controller is designed by applying the norm inequality to the system uncertainties and external disturbances. Compared to the existing consensus control approaches, the prime advantage of the proposed one is that the constraints generated from the communication ranges are approximated by a time-varying contractive performance envelope, wherein, the appointed-time convergence and steady-state tracking accuracy are preassigned a priori. Meanwhile, no repeated logarithmic error transformations are required in the relevant controller design, which implies that the complexity of the devised control laws has decreased dramatically. Finally, two groups of illustrative examples are organized to validate the effectiveness of the proposed consensus control approach.

Energy management system is very critical for solving the energy problem of a long endurance stratospheric airship. But the researches about the energy management system and energy management strategy for a stratospheric airship are rare. This paper presents the hybrid energy system consisting of one renewable energy system and two energy storage systems. Combined with the models of energy harvesting, balance and storage, and the thermal model of the PV (Photovoltaic) panel, the details of the rule-based energy management strategy to cooperate the three energy sources or storage devices: photovoltaic, lithium battery and fuel cell are obtained. Furthermore, the energy management strategy in the situation of a storage system failure is proposed to ensure the operation of the airborne equipment. In the course of the investigation, the power curves and the state of charge of the energy storage systems are reported in detail to prove the validity and applicability of the management strategies. It indicates that the energy system of the airship can provide uninterrupted energy to control system and payload system, but can not resist the wind drag after LB failure, which will increase the difficulty of the trajectory planning. The results indicate that the strategy is helpful for planning energy management.

The high altitude solar-powered airships have been proposed for use as long endurance platforms, for a variety of military and civilian applications. The challenges of perpetual endurance flight require the airship to generate sufficient power over a wide range of operational latitudes so that the aerial vehicle can keep station through high wind events and maintain persistence. This paper provides a theoretical approach to analyzing the perpetual endurance performance of a high altitude solar-powered airship. According to the features of stratospheric airship and the theoretical model, a custom tool is developed using MATLAB computer program when the airship operates in the cruise condition. The effects of the operational latitudes, wind velocities and solar array areas on the energy ratio are numerically investigated in detail, and the required areas of solar array under the conditions of different minimum energy ratio were discussed. The results showed that the solar-powered airships faced severe operational limitations at high latitudes in the winter, especially in the high wind. In addition, a case study was analyzed to demonstrate the effectiveness of this approach to predicting the perpetual endurance region. The results demonstrated that the theoretical approach suggested a pathway towards planning the flight date and location for an airship.

The three-dimensional multiple constrained guidance problem for a hypersonic gliding vehicle (HGV) against a stationary ground target in dive phase is investigated. A coupled nonlinear dynamic model is established on account of the bank-to-turn control scheme adopted by the HGV, which formulates the relation between line-of-sight angles and trajectory control variables. On this basis, a finite-time nonlinear disturbance observer is introduced to estimate the lumped uncertainty. Utilizing the estimation as feedforward compensation, a guidance law based on the adaptive multivariable super-twisting sliding mode control is designed to realize precise strike with designated impact angles. The finite-time stability of closed-loop guidance system is proven through the Lyapunov technique. Numerical simulations are executed to validate the mission adaptiveness and the robustness of the presented guidance scheme.

The maintenance of the nominal multirevolution elliptic halo orbit, whose special features can benefit mercurial explorations, is first investigated through Monte–Carlo simulations in the elliptic Sun–Mercury model, and then validated in the high-fidelity ephemeris model. The receding horizon control strategy solved by the indirect Radau pseudospectral method demonstrates that the orbit can be maintained robustly with respect to very large initial deviations. Moreover, the result proves that the elliptic Sun–Mercury model is an accurate approximation.

This paper develops a comprehensive methodology to address the attitude control problem of hypersonic vehicles in the presence of matched model uncertainties and external disturbances. Init...

Osteosarcoma (OS) is recognized as a common malignant tumor with a high trend of metastasis and diffusion. Despite the progresses that have been made in surgery, chemotherapy, and radiotherapy in the recent decades, the prognosis of patients with OS still remains poor. MiRNAs are being increasingly considered as new therapeutic targets for OS treatment. Our research aims to investigate the regulatory impact of miR-92a in the development of OS. Quantitative real-time PCR (qRT-PCR) results revealed that the expression of miR-92a was aberrantly overexpressed in human OS cell lines. By using cell counting kit-8 (CCK-8) assays, colony formation assays, flow cytometric analyses and Transwell assays, our data suggested that up-regulation of miR-92a promoted the proliferation, migration, and invasion of MNNG and U2OS cells, while inhibiting their apoptosis. In contrast, the knockdown of miR-92a effectively reversed these cellular biological behaviors. Furthermore, bioinformatics analysis indicated that Dickkopf-related protein 3 (DKK3) was a possible target of miR-92a. Subsequently, negative regulation of miR-92a on DKK3 was observed, which further supported the direct binding between them. In addition, silencing DKK3 rescued the inhibitory effect of miR-92a inhibitor on the development of OS. To sum up, our study revealed that miR-92a played a carcinogenic role in the growth of OS by promoting the tumorigenesis of OS cells via targeting of DKK3, thus revealing a new therapeutic target for OS.

Osteosarcoma (OS) is the most frequent primary malignant bone tumour. Alternol, a novel compound purified from microbial fermentation products exerts anti‐tumour effects across several cancer types. The effect of alternol on human OS remains to be elucidated. We first evaluated the anti‐tumour effect of alternol in several human OS cell lines in vitro and investigated its underlying mechanism. Alternol inhibited OS cell proliferation, migration and induced caspase‐dependent apoptosis, G2/M cell cycle arrest in a dose and time‐dependent manner. Moreover, alternol treatment inhibited signal transducer and activator of transcription‐3 (STAT3) phosphorylation in 143B and MG63 human OS cells, as evaluated using a STAT3‐dependent dual luciferase reporter system. Exposure to alternol resulted in excessive reactive oxygen species (ROS) generation and Jun amino‐terminal kinases (JNK), extracellular signal‐regulated kinases (ERK1/2) and p38 activation. Furthermore, alternol‐induced cell death was significantly restored in the presence of the ROS scavenger, N‐acetyl‐l‐cysteine (NAC) or a caspase inhibitor Z‐VAD‐FMK. NAC also prevented G2/M phase arrest and phosphorylation of mitogen‐activated protein kinases (MAPK), but did not reverse STAT3 inactivation. Finally, alternol suppressed tumour growth in vivo in the nude mouse OS tibia orthotopic model. Immunohistochemistry revealed that alternol treatment resulted in down‐regulation of phosph‐STAT3 Tyr705 and up‐regulation of cleaved caspase‐3 and phosph‐SAPK (Stress‐activated protein kinases)/JNK expression. Taken together, our results reveal that alternol suppresses cell proliferation, migration and induces apoptosis, cell cycle arrest by modulating of ROS‐dependent MAPK and STAT3 signalling pathways in human OS cells. Therefore, alternol is a promising candidate for developing anti‐tumour drugs target OS.

Monocyte chemotactic protein-1 (MCP-1/CCL2) is an important immune factor, which may be important in cancer progression by promoting proliferation, invasion, metastasis and the tumor microenvironment. Previous studies have demonstrated that CCL2 affects the proliferation of osteosarcoma cells via the RANKL signaling pathway. However, the underlying mechanisms remain to be elucidated. To investigate the role of CCL2 in osteosarcoma cells, MTT, spheroid forming, wound healing and transwell assays were performed to examine the proliferation and invasion abilities of the osteosarcoma cells. It was revealed that the high-grade osteosarcoma cells exhibited increased expression levels of CCL2 compared with the low-grade osteosarcoma cells (P

In recent years, with the increase of consumers’ attention to the quality of agricultural products, reliable and reliable traceability technology of agricultural products has been paid more attention. This paper proposed a block-chain traceability system based on smart agriculture with the integration of wireless sensor network. The system has realized the agricultural product traceability system based on Ethereum. After farmers access to the system, data acquisition front-end data storage to block-chain system, the use of block-chain itself has the characteristics of decentralization, tamper-resistant, security encryption, combined with the backend database management and traceability QR code to provide consumers with safe, reliable and real farm products traceability information. Building a holographic database of the tea whole industry chain from farmland to table, adopting the food risk assessment and safety traceability technology based on the hazard factor to design the multi-role, multi-link and multi-factor intelligent management system to realize the efficient control of food quality and safety.

Osteosarcoma (OS) has an unfavorable prognosis and tends to metastasize to lung tissue. Although the CXCL12-CXCR4 axis appears to affect progression and metastasis in numerous tumors, its mechanism and downstream pathways in OS remain unclear. We used western blotting and flow cytometry to detect CXCR4 and CXCR7 expression in two OS cell lines (LM8 and Dunn). An MTT assay was used to evaluate the effects of CXCL12 and AMD3100, a specific CXCR4 antagonist, on cell viability. Flow cytometry was utilized to analyze changes in apoptosis induced by serum deprivation following treatment with CXCL12 and AMD3100. A Transwell assay was used to assess cell migration in response to CXCL12 and AMD3100. Western blotting was performed to identify the phosphorylation of signaling molecules (JNK, c-Jun, Akt, p38 and Erk1/2) and expression of caspase-3 and -8, and PARP. Mouse models were employed to evaluate AMD3100 inhibition of primary OS growth and lung metastasis in vivo. CXCR4 expression was detected in LM8 but not Dunn cells, and neither cell line expressed CXCR7. The addition of CXCL12 induced the survival and migration of serum-starved CXCR4+ LM8 cells activating JNK and Akt pathways, which were abrogated by adding AMD3100. However, similar results were not observed in CXCR4− Dunn cells. CXCL12 protected LM8, but not Dunn cells, from apoptosis induced by serum deprivation by suppressing PARP cleavage, which was partly reversed by AMD3100. In a mouse model, AMD3100 reduced primary tumor growth and lung metastasis compared with the controls. Thus, the CXCL12-CXCR4 axis regulated OS survival and metastasis through the JNK and Akt pathways, and blocking them with AMD3100 was found to be a potential OS treatment.

The objective of this study is to do a meta-analysis of the literature and compare the safety and efficacy of endoscopic carpal tunnel release (ECTR) and open carpal tunnel release (OCTR) for idiopathic carpal tunnel syndrome (CTS). A comprehensive literature search of the electronic databases MEDLINE, EMBASE, Google Scholar, and the Cochrane Controlled Trial Register was undertaken for randomized studies reporting carpal tunnel syndrome treated with ECTR or OCTR. The quality of randomized trials was critically assessed. Pooled relative risk (RR) and 95% confidence intervals (CIs) for safety and efficacy outcome variables were calculated by fixed-effect or random-effect methods with RevMan v.5.1 provided by the Cochrane Collaboration. A total of 13 randomized trials were included by total retrieve and riddling. The results of our meta-analysis showed no significant difference in the overall complication rate (RR = 1.34, 95% CI [0.74, 2.43], P = 0.34), subjective satisfaction (RR = 1.0, 95% CI [0.93, 1.08], P = 0.92), time to return to work (mean difference = −3.52 [−8.15, 1.10], P = 0.14), hand grip and pinch strength, and the operative time (mean difference = −1.89, 95% CI [−5.84, 2.06]) between patients in the ECTR and OCTR groups (P = 0.16, 0.70, and 0.35, respectively). The rate of hand pain (RR = 0.73, 95% CI [0.53, 0.93], P = 0.02) in the ECTR group was significantly lower than that in the OCTR group. ECTR treatment seemed to cause more reversible postoperative nerve injuries as compared with OCTR (RR = 2.38, 95% CI [0.98, 5.77], P = 0.05). Although ECTR significantly reduced postoperative hand pain, it increased the possibility of reversible postoperative nerve injury in patients with idiopathic CTS. No statistical difference in the overall complication rate, subjective satisfaction, the time to return to work, postoperative grip and pinch strength, and operative time was observed between the two groups of patients.

Background Osteosarcoma is the most frequent primary malignant bone tumor, notorious for its lung metastasis. Shikonin, an effective constituent extracted from Chinese medicinal herb, was demonstrated to induce necroptosis in some cancers. Methods MTT assay was performed to detect cell survival rate in vitro. Flow cytometry was used to analyze cell cycle and cell death. Western blot was performed to determine the expression levels of RIP1, RIP3, caspase-3, caspase-6 and PARP. The tibial primary and lung metastatic osteosarcoma models were used to evaluate the anti-tumor effect of shikonin in vivo. Results The cell survival rate was decreased in a dose and time dependent manner when treated with shikonin. No major change in cell cycle was observed after shikonin treatment. The cell death induced by shikonin could be mostly rescued by specific necroptosis inhibitor necrostatin-1, but not by general caspase inhibitor Z-VAD-FMK. The number of necrotic cells caused by shikonin was decreased after being pretreated with Nec-1 detected by flow cytometry in K7 cells. After 8-hour treatment of shikonin, the expression levels of RIP1 and RIP3 were increased while caspase-3, caspase-6 and PARP were not activated in K7 and U2OS cells determined by Western blot. Size of primary tumor and lung metastasis in shikonin treated group were significantly reduced. The protein levels of RIP1 and RIP3 in primary tumor tissues were increased by shikonin. The overall survival of lung metastatic models was longer compared with control group (p Conclusions Shikonin had prompt but profound anti-tumor effect on both primary and metastatic osteosarcoma, probably by inducing RIP1 and RIP3 dependent necroptosis. Shikonin would be a potential anti-tumor agent on the treatment of primary and metastatic osteosarcoma.

Bone sarcomas, which comprise less than 1% of all human malignancies, are a group of relatively rare mesenchymal-derived tumors. They are mainly composed of osteosarcoma, chondrosarcoma and Ewing's sarcoma. In spite of advances in adjuvant chemotherapy and wide surgical resection, prognosis remains poor due to the high propensity for lung metastasis, which is the leading cause of mortality in patients with bone sarcomas. Chemokines are a superfamily of small pro-inflammatory chemoattractant cytokines which can bind to specific G protein-coupled seven-span transmembrane receptors. Chemokine 12 (CXCL12), also designated as stromal cell-derived factor-1 (SDF-1), is able to bind to its cognate receptors, chemokine receptor 4 (CXCR4) and chemokine receptor 7 (CXCR7), with high affinity. The binding of CXCL12 to CXCR4/CXCR7 stimulates the activation of several downstream signaling pathways that regulate tumor progression and metastasis. In this review, the structure and function of CXCL12 and its receptors, CXCR4 and CXCR7, as well as many factors affecting their expression are discussed. Phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways are the two most important downstream pathways regulated by the CXCL12-CXCR4/CXCR7 interaction. CXCR4 expression in bone sarcomas, including tumor cells and samples and the correlation between CXCR4/CXCR7 expression and the survival of patients with bone sarcomas are also discussed. In addition, we review the involvement of the CXCL12‑CXCR4/CXCR7 axis in the growth and metastasis of bone sarcomas and the targeting of this axis in preclinical studies.

Multiple criteria and multiple constraint-level linear programming (MC 2 LP) is a major part of the Multiple Criteria Decision Making (MCDM). Although MC 2 LP has been widely applied in many fields, its theories and applications need to be further studied and discussed. With the implicit assumption of the existing optimization techniques in oilfield development planning that resource constraint-level is fixed, this paper proposes and builds the concepts, models and algorithms of MC 2 oilfield development planning based on the current theories and methods of the oilfield development and MC 2 LP. Their applying studies have shown that the MC 2 LP method and technology of oilfield development created by our group can provide a better basis for decision making of oilfield development planning and oilfield management as well as operation.