In this paper, we investigate the formation control of multiple unmanned aerial vehicles (UAVs), specifically unmanned aircraft, in an obstacle-laden environment. The main contribution of this paper ...is to integrate the formation control, trajectory tracking, and obstacle/collision avoidance into one unified optimal control framework. A nonquadratic avoidance cost is innovatively constructed via an inverse optimal control approach, which leads to an analytical, distributed, and optimal formation control law. The stability and optimality of the closed-loop system are proven. In addition, the proposed optimal control law is dependent only on the information from the local neighbors, rather than all UAVs' information. Simulation of multiple UAVs' formation flying demonstrates the effectiveness of the integrated optimal control design with desired behaviors including formation flying, trajectory tracking, and obstacle/collision avoidance.
•Non-invasive mALPS-index was closely related to the classical detected glymphatic clearance function, providing an alternative method in researches on glymphatic system.•WMHs, lacunas, microbleeds ...and EPVS in basal ganglia were related to glymphatic clearance function.•Glymphatic clearance function was related to cognitive function in CSVD patients.
Few studies have focused on the connection between glymphatic dysfunction and cerebral small vessel disease (CSVD), partially due to the lack of non-invasive methods to measure glymphatic function. We established modified index for diffusion tensor image analysis along the perivascular space (mALPS-index), which was calculated on diffusion tensor image (DTI), compared it with the classical detection of glymphatic clearance function calculated on Glymphatic MRI after intrathecal administration of gadolinium (study 1), and analyzed the relationship between CSVD imaging markers and mALPS-index in CSVD patients from the CIRCLE study (ClinicalTrials.gov ID: NCT03542734) (study 2). Among 39 patients included in study 1, mALPS-index were significantly related to glymphatic clearance function calculated on Glymphatic MRI ( r = -0.772~-0.844, p < 0.001). A total of 330 CSVD patients were included in study 2. Severer periventricular and deep white matter hyperintensities (β = -0.332, p < 0.001; β = -0.293, p < 0.001), number of lacunas (β = -0.215, p < 0.001), number of microbleeds (β = -0.152, p = 0.005), and severer enlarged perivascular spaces in basal ganglia (β = -0.223, p < 0.001) were related to mALPS-index. Our results indicated that non-invasive mALPS-index might represent glymphatic clearance function, which could be applied in clinic in future. Glymphatic clearance function might play a role in the development of CSVD.
Hyperactivation of hypothalamic-pituitary-adrenal (HPA) axis and hypothalamic-pituitary-thyroid (HPT) axis were found in acute high altitude challenge, but the role of gut microbiota and metabolites ...is unknown. We utilized adult male Sprague-Dawley rats at a simulated altitude of 5500 m for 3 days in a hypobaric-hypoxic chamber. ELISA and metabolomic analyses of serum and 16S rRNA and metabolomic analyses of fecal samples were then performed. Compared with the normoxic group, serum corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), corticosterone (CORT), and thyroxine (tT
) were increased in the hypoxia group, whereas thyrotropin-releasing hormone (TRH) was decreased. Bacteroides, Lactobacillus, Parabacteroides, Butyricimonas, SMB53, Akkermansia, Phascolarctobacterium, and Aerococcus were enriched in hypoxia group, whereas Prevotella, Prevotella, Kaistobacter, Salinibacterium, and Vogesella were enriched in normoxic group. Metabolomic analysis indicated that acute hypoxia significantly affected fecal and serum lipid metabolism. In addition, we found five fecal metabolites may mediate the cross-talk between TRH, tT
, and CORT with Prevotella, Kaistobacter, Parabacteroides, and Aerococcus, and 6 serum metabolites may mediate the effect of TRH and tT
on Prevotella and Kaistobacter by causal mediation analysis. In conclusion, this study provides new evidence that key metabolites mediate the cross-talk between gut microbiota with HPA and HPT axis under acute hypobaric hypoxia challenge.
β-catenin is an important regulator of malignant progression. 17β-Estradiol (E2), an important sex hormone in women, promotes the growth and metastasis of triple-negative breast cancer (TNBC). ...However, whether β-catenin is involved in E2-induced metastasis of TNBC remains unknown. In this study, we show that E2 induces the proliferation, migration, invasion, and metastasis of TNBC cells. E2 induces β-catenin protein expression and nuclear translocation, thereby regulating the expression of target genes such as Cyclin D1 and MMP-9. The inhibition of β-catenin reversed the E2-induced cell malignant behaviors. Additionally, E2 activated Calpain by increasing intracellular Ca2+ levels and reducing calpastatin levels. When Calpain was inhibited, E2 did not induce the proliferation, migration, invasion, or metastasis of TNBC cells. In addition, E2 promoted translocation of YAP into the nucleus by inhibiting its phosphorylation. Calpain inhibition reversed the E2-induced YAP dephosphorylation. Inhibition of YAP transcriptional activity reversed the effects of E2 on the proliferation, migration, invasion, and β-catenin of TNBC cells. In conclusion, we demonstrated that E2 induced metastasis-related behaviors in TNBC cells and this effect was mediated through the Calpain/YAP/β-catenin signaling pathway.
The experiments of arsenic removal from flue gas were investigated at a lab-scale bubbling reactor with H2O2 solution to develop a novel oxidation process. The effects of various experimental ...parameters, such as H2O2 concentration, initial solution pH, reaction temperature, and flue gas components (O2, CO2, SO2, and NO) were systematically investigated, and the average removal efficiency was found to be 92.6%, under the obtained optimal conditions, in which H2O2 concentration was 0.2 mol/L, solution pH was 5.0, and reaction temperature was 50 °C. Meanwhile, the mechanism of the reaction was proposed based on characterizations of the removed products by high performance liquid chromatography coupled to hydride generation atomic fluorescence spectrometry, atomic fluorescence spectrometry as well as a review of the literature.
•ITIH4 might be a new biomarker in diagnosing the bacterial bloodstream infection.•ITIH4 elevated in the bacteremia mainly due to regulated by IL-6 or LPS through JAK/STAT pathway.•ITIH4 has a good ...performance in differentiating the bacteremia from fungemia or MP infection.
Bloodstream infection (BSI) is usually accompanied with the changes of varieties of inflammation proteins. In our previous study, we identified that inter-α-trypsin inhibitor heavy chain H4 (ITIH4) was highly expressed in the infection arms than the normal control arm. However, the correlated verification and mechanism remain obscure. Escherichia coli infected mice model and clinical serum samples were used to validate the concentration of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), as well as ITIH4, in ELISA method. Cytokines (IL-6, TNF-α, IL-10 and lipopolysaccharide (LPS)) were used to stimulate the HepG2 cell model to explore which cytokines influence the expression of ITIH4. JAK/STAT inhibitor was treated before IL-6 and LPS stimulation. Westernblot, as well as real-time PCR were performed to detect the expression of ITIH4 in liver tissue from protein and transcription levels. Immunohistochemistry analysis was used to observe the expression of ITIH4 in mice liver tissue. In mice model, IL-6, TNF-α, as well as IL-10 increased in the infection arms than the normal control arm. ITIH4 in serum and liver tissue of mice model increased from 1 h to 128 h, which were remarkably different from that of the normal control arm. Besides, ITIH4 increased in the bacterial infection arm greatly than the fungemia arm, mycoplasma pneumoniae (MP) arm and febrile arm in clinical serum samples. Furthermore, using the HepG2 cell line, we demonstrated that ITIH4 was up-regulated at both protein and mRNA levels upon dose- and time- response treatments with IL-6, as well as LPS. Moreover, IL-6 or LPS mediated induction of ITIH4 expression could be significantly decreased by treatment with an JAK/STAT inhibitor in protein or mRNA level. No changes were observed after TNF-α or IL-10 stimulation. ITIH4 might be a critical inflammatory biomarker which correlated with the development of BSI, especially with bacterial bloodstream infection. It is expected that this study would provide some insights into potential functional mechanisms underlying BSI.
The cuckoo search algorithm is a simple and effective global optimization algorithm. It has been successfully applied to solve a wide range of real-world optimization problem. In this paper, we use a ...new search strategy based on orthogonal learning strategy to enhance the exploitation ability of the basic cuckoo search algorithm. In order to verify the performance of our approach, 23 benchmark functions are employed. Experimental results indicate that the proposed algorithm performs better than or at least comparable to state-of-the-art approaches from literature when considering the quality of the solution obtained.
With a series of widespread applications, resistive gas sensors are considered to be promising candidates for gas detection, benefiting from their small size, ease-of-fabrication, low power ...consumption and outstanding maintenance properties. One-dimensional (1-D) nanomaterials, which have large specific surface areas, abundant exposed active sites and high length-to-diameter ratios, enable fast charge transfers and gas-sensitive reactions. They can also significantly enhance the sensitivity and response speed of resistive gas sensors. The features and sensing mechanism of current resistive gas sensors and the potential advantages of 1-D nanomaterials in resistive gas sensors are firstly reviewed. This review systematically summarizes the design and optimization strategies of 1-D nanomaterials for high-performance resistive gas sensors, including doping, heterostructures and composites. Based on the monitoring requirements of various characteristic gases, the available applications of this type of gas sensors are also classified and reviewed in the three categories of environment, safety and health. The direction and priorities for the future development of resistive gas sensors are laid out.
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•The cross electrode can form an electric field with the larger impact area and higher electric field intensity.•The coupling effect of cross corona discharge and turbulence can ...prolong the particle residence time in the electric field.•The longer deviate distance from electrode can provide more opportunities for fine particles to collide and coagulate.
Fine particulate matters emitted from the industrial flue gas are the primary reason for the serious haze problem. The agglomeration has been proven an effective method to improve fine particle removal efficiency, but the movement characteristics in the process and their effects on the agglomeration are unclear. In this study, the agglomeration and the underlying mechanisms in the various electric fields were investigated. The results showed that the removal efficiency of fine particles can reach near 80% under the coupling effect of turbulence and cross discharge electrode, and the particle size can be increased by 30% simultaneously. The electric field intensity with cross electrode approached 650,000 V/m and higher than another three conventional electrodes with 60,000–200,000 V/m. The residence time of fine particle was extended to 0.2 s in the electric field with cross electrodes, and the deviate distance from the discharge electrode was nearly 3 times than other electrodes. The longer residence time and the more disordered movements can make fine particles carry more charge amounts and have more opportunities to finish coagulations. This study discussed the charged particles movement characteristics under the electric fields coupling with turbulence, and explored the further effects on the agglomeration and removal of fine particles. It’s designed to provide the guidance for the setting and improvement of electric fields in the dust removal equipment.
Exploring highly efficient non-Pt oxygen reduction reaction (ORR) electrocatalysts is an inevitable trend in the progress of various sustainable energy storage and conversion technologies. Herein, we ...prepare three kinds of hierarchical porous carbons, derived from hypercrosslinked polyaniline (HCP-An), polypyrrole (HCP-Py) and polymethylbenzene (HCP-MB) through a facile Friedel-Crafts reaction, among which NPC-An-900 exhibits outstanding ORR catalytic performance combining high surface area, good conductivity and high nitrogen-doped content. The hypercrosslinked polyaniline ensures micro-/mesoporous skeleton and prevents collapse during the pyrolysis process for NPC-An-900 with a high surface area of 2938.31 m2 g−1 and hierarchical micro-/mesoporous structure (1–8 nm). High nitrogen-doping content of NCP-An-900 is up to 7.02 at.% with pyridinic N as the main nitrogen doped type of 48.5% of the total nitrogen content. NPC-An-900 manifests an onset potential of 0.96 V (vs. RHE) with a high limiting current density of −5.31 mA cm−2 (superior to the commercial Pt/C of −5.20 mA cm−2) and excellent stability with current retention of 96.2% over 7.5 h. Furthermore, the extraordinary tolerance against methanol corrosion would also indicate its potential practical applications. This simple and universal synthesis strategy can be widely applied in the preparation of other porous heteroatom-doped carbons derived functional polymers towards energy storage and conversion.
Hyperporous nitrogen-doped electrocatalyst NPC-An-900 is prepared from hypercrosslinked polyaniline, with high surface area of 2938.31 m2 g−1, good conductivity and high nitrogen-doped content of 7.02 at.% with striking enrichment of pyridinic N as high as 48.50 at.% of the total nitrogen content. NCP-An-900 exhibits excellent catalytic activity (Eonset = 0.96 V, E1/2 = 0.85 V), methanol tolerance and stability with current retention of 96.2% over 7.5 h, indicating its potential practical applications. Display omitted
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