InGVIO: A Consistent Invariant Filter for Fast and High-Accuracy GNSS-Visual-Inertial Odometry

Combining Global Navigation Satellite System (GNSS) with visual and inertial sensors can give smooth pose estimation without drifting in geographical coordinates. The fusion system gradually degrades to Visual-Inertial Odometry (VIO) with the number of satellites decreasing, which guarantees robust global navigation in GNSS unfriendly environments. In this letter, we propose an open-sourced invariant filter-based platform, InGVIO, to tightly fuse monocular/stereo visual-inertial measurements, along with raw data from GNSS, i.e. pseudo ranges and Doppler shifts. InGVIO gives highly competitive results in terms of accuracy and computational load compared to current graph-based and `naive' EKF-based algorithms. Thanks to our proposed key-frame marginalization strategies, the baseline for triangulation is large although only a few cloned poses are kept. Besides, landmarks are anchored to a single cloned pose to fit the nonlinear log-error form of the invariant filter while achieving decoupled propagation with IMU states. Moreover, we exploit the infinitesimal symmetries of the system, which gives equivalent results for the pattern of degenerate motions and the structure of unobservable subspaces compared to our previous work using observability analysis. We show that the properly-chosen invariant error captures such symmetries and has intrinsic consistency properties. InGVIO is tested on both open datasets and our proposed fixed-wing datasets with variable levels of difficulty. The latter, to the best of our knowledge, are the first datasets open-sourced to the community on a fixed-wing aircraft with raw GNSS.Comment: 8 pages, 8 figures; manuscript will be submitted to IEEE RA-L for possible publicatio

The Breaking Span of Thick and Hard Roof Based on the Thick Plate Theory and Strain Energy Distribution Characteristics of Coal Seam and Its Application

In mining engineering, the thick and hard roof threatens the safe production. Based on Reissner plate theory and combined with weighted residual method, with four edges clamped as the boundary conditions, this paper deduces the theoretical formula of the first breaking span of thick and hard roof. Based on Vlasov plate theory, with four edges simply supported as the boundary conditions, this paper deduces the theoretical formula of the periodic breaking span of thick and hard roof. The two formulas are used to verify the breaking span of thick and hard roof of Tashan Coal Mine, proving that its accuracy is higher than that of traditional beam theory. This paper studies the distribution characteristics of strain energy density in front of the coal seam during the mining process by numerical simulation, which is compared with the results of field microseismic experiments. It is found that the strain energy density of the coal seam has a good correlation with the probability of microseismic events. This paper provides theoretical support for more precise calculation of breaking span of the thick and hard roof and technical support for the practical stability analysis of the surrounding rock under the thick and hard roof

A Risk Model Developed Based on Homologous Recombination Deficiency Predicts Overall Survival in Patients With Lower Grade Glioma

The role of homologous recombination deficiency (HRD) in lower grade glioma (LGG) has not been elucidated, and accurate prognostic prediction is also important for the treatment and management of LGG. The aim of this study was to construct an HRD-based risk model and to explore the immunological and molecular characteristics of this risk model. The HRD score threshold = 10 was determined from 506 LGG samples in The Cancer Genome Atlas cohort using the best cut-off value, and patients with highHRDscores had worse overall survival. A total of 251 HRD-related genes were identified by analyzing differentially expressed genes, 182 of which were associated with survival. A risk score model based on HRD-related genes was constructed using univariate Cox regression, least absolute shrinkage and selection operator regression, and stepwise regression, and patients were divided into high- and low-risk groups using the median risk score. High-risk patients had significantly worse overall survival than lowrisk patients. The risk model had excellent predictive performance for overall survival in LGG and was found to be an independent risk factor. The prognostic value of the riskmodel was validated using an independent cohort. In addition, the risk score was associated with tumor mutation burden and immune cell infiltration in LGG. High-risk patients had higher HRD scores and “hot” tumor immune microenvironment, which could benefit from poly-ADP-ribose polymerase inhibitors and immune checkpoint inhibitors. Overall, this big data study determined the threshold of HRD score in LGG, identified HRD-related genes, developed a risk model based on HRD-related genes, and determined the molecular and immunological characteristics of the risk model. This provides potential new targets for future targeted therapies and facilitates the development of individualized immunotherapy to improve prognosis

Multidrug Resistant Brain Abscess Due to Acinetobacter baumannii Ventriculitis Cleared by Intraventricular and Intravenous Tigecycline Therapy: A Case Report and Review of Literature

Objective: Ventricular infection from multidrug-resistant (MDR) Acinetobacter baumannii (A. baumannii) is one of the most severe complications of craniotomy. However, the availability of effective therapeutic options for these infections is limited. Thus, this report aims to describe the efficacy of abscess clearance by intraventricular and intravenous tigecycline therapy in managing patients with multidrug-resistant A. baumannii ventriculitis after neurosurgery. Moreover, the current literature on the use of tigecycline therapy for these life-threatening infections is reviewed and summarized, and a treatment regimen based on the available data is proposed.Methods: A patient with multidrug-resistant A. baumannii ventriculitis was admitted in our hospital and was provided with a detailed therapeutic schedule. Tigecycline treatments for multidrug-resistant A. baumannii ventriculitis that were reported in the literature were also reviewed and summarized.Results: The patient in our hospital underwent abscess clearance on a ventriculoscope and was subsequently subjected to multi-route tigecycline therapy 14 days after the start of the continuous ventricular irrigation (CVI) tigecycline and 3 days after the intraventricular (IVT) tigecycline. The signs of ventriculitis disappeared, and the Acinetobacter cerebrospinal fluid (CSF) load steadily decreased until CSF sterilization. Literature review identified seven cases of ventricular infection from multidrug-resistant A. baumannii treated with tigecycline. In the eight cases, all patients were male adults (>18 years), with a mean age of 46.1 (range: 22–75) years. Meningitis/ventriculitis was secondary to neurosurgery procedures for the management of various central nervous system diseases in all cases. A good clinical outcome was achieved in all eight patients with multidrug-resistant A. baumannii meningitis/ventriculitis treated with CVI and/or IVT tigecycline, and any relevant complications were not observed.Conclusions: CVI and IVT tigecycline and IVT colistin could be considered as the first-line therapy in patients with ventricular infections from MDR/extreme drug-resistant A. baumannii. However, more studies should be conducted to confirm our observation

Profile of immunoglobulin G N-glycome in COVID-19 patients: A case-control study

Coronavirus disease 2019 (COVID-19) remains a major health challenge globally. Previous studies have suggested that changes in the glycosylation of IgG are closely associated with the severity of COVID-19. This study aimed to compare the profiles of IgG N-glycome between COVID-19 patients and healthy controls. A case-control study was conducted, in which 104 COVID-19 patients and 104 age- and sex-matched healthy individuals were recruited. Serum IgG N-glycome composition was analyzed by hydrophilic interaction liquid chromatography with the ultra-high-performance liquid chromatography (HILIC-UPLC) approach. COVID-19 patients have a decreased level of IgG fucosylation, which upregulates antibody-dependent cell cytotoxicity (ADCC) in acute immune responses. In severe cases, a low level of IgG sialylation contributes to the ADCC-regulated enhancement of inflammatory cytokines. The decreases in sialylation and galactosylation play a role in COVID-19 pathogenesis via the activation of the lectin-initiated alternative complement pathway. IgG N-glycosylation underlines the complex clinical phenotypes of SARS-CoV-2 infection

Lactic acid bacteria with a strong antioxidant function isolated from “Jiangshui,” pickles, and feces

Excessive free radicals and iron death lead to oxidative damage, which is one of the main causes of aging and diseases. In this field of antioxidation, developing new, safe, and efficient antioxidants is the main research focus. Lactic acid bacteria (LAB) are natural antioxidants with good antioxidant activity and can regulate gastrointestinal microecological balance and immunity. In this study, 15 LAB strains from fermented foods (“Jiangshui” and pickles) or feces were evaluated in terms of their antioxidant attributes. Strains with strong antioxidant capacity were preliminarily screened by the following tests: 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl radical, superoxide anion radical scavenging capacity; ferrous ion chelating assay; hydrogen peroxide tolerance capacity. Then, the adhesion of the screened strains to the intestinal tract was examined using hydrophobic and auto-aggregation tests. The safety of the strains was analyzed based on their minimum inhibitory concentration and hemolysis, and 16S rRNA was used for molecular biological identification. Antimicrobial activity tests showed them probiotic function. The cell-free supernatant of selected strains were used to explore the protective effect against oxidative damage cells. The scavenging rate of DPPH, hydroxyl radicals, and ferrous ion-chelating of 15 strains ranged from 28.81–82.75%, 6.54–68.52%, and 9.46–17.92%, respectively, the scavenging superoxide anion scavenging activity all exceeded 10%. According to all the antioxidant-related tests, strains possessing high antioxidant activities J2-4, J2-5, J2-9, YP-1, and W-4 were screened, these five strains demonstrated tolerance to 2 mM hydrogen peroxide. J2-4, J2-5, and J2-9 were Lactobacillus fermentans and γ-hemolytic (non-hemolytic). YP-1 and W-4 were Lactobacillus paracasei and α-hemolytic (grass-green hemolytic). Although L. paracasei has been proven as a safe probiotic without hemolytic characteristics, the hemolytic characteristics of YP-1 and W-4 should be further studied. Due to the weak hydrophobicity and antimicrobial activity of J2-4, finally, we selected J2-5, J2-9 for cell experiment, J2-5 and J2-9 showed an excellent ability that resistant to oxidative damage by increasing SOD, CAT, T-AOC activity of 293T cells. Therefore, J2-5, and J2-9 strains from fermented foods “Jiangshui” could be used as potential antioxidants for functional food, health care, and skincare

Mixed-Sensitivity Control for Drag-Free Spacecraft Based on State Space

This paper investigates a mixed-sensitivity control method for a class of drag-free spacecraft-needed frequency-separation control, which overcomes the coupled problem of a multiple-in multiple-out (MIMO) system with multiple sensitive-axes and disturbances of actuators. Firstly, the relative dynamics equation is established based on the character of displacement error, which is separated by that test-mass (TMs) tracking ideal orbit with high-frequency displacement and cavity of spacecraft tracking TMs with low-frequency displacement. Secondly, the feedback gain matrix is obtained by the LMI/SDP, which is devised by a general system containing a weight function. Finally, the simulation results demonstrate the performance of the proposed method

Durability of thermal insulating bio-based lightweight concrete: understanding of heat treatment on bio-aggregates

The organic matter, surface properties and biodegradation of bio-based aggregates are the main factors for their poor performance of bio-based lightweight concrete. In the present study, heat-treatment is applied to bio-aggregates for reducing their negative impacts on cement hydration and performance of thermal insulating bio-based lightweight concrete. The results show that heat-treated bio-aggregates have reduced negative impacts on cement hydration by the decomposition of organic matter and increase of the pH of the leachate, and significantly improves the mechanical strength of concrete. The 28-day compressive strength and flexural strength of heat-treated apricot shell (HAS) concrete increase by 50.2% and 87.7%, respectively, compared to the untreated apricot shell (AS) concrete. The bio-based lightweight concrete in this study has an excellent thermal insulation property, and the thermal conductivity varies from 0.56 W/m·K and 1.25 W/m·K. Moreover, the heat-treated bio-based aggregate significantly reduces the drying shrinkage of concrete. At 108 days, the drying shrinkage of concrete containing heat-treated aggregates reduces by 29.2%-36.1%. Besides, the heat-treated bio-based aggregate enhances the resistance to freeze–thaw cycles, attributed to the reduced micro-cracks and porosity of concrete. Therefore, heat treatment can improve the properties of bio-based aggregates and significantly increase the durability of thermal insulating bio-based lightweight concrete

Calculative Width of Pile Foundation on Slope Based on Particle Image Velocimetry (PIV)

The calculative width directly affecting the horizontal bearing capacity of the pile is an important parameter of the horizontal loaded pile foundation and its effective value will change with the variation of slope angle. In order to research the effect of slope on calculative width, 4 groups of model test under static lateral loading with different slope angles were carried out indoor. Based on the PIV system, the horizontal diffusion angle was obtained by the quantitative analysis of the vectorial displacement field of soil around the pile. The calculative width of pile under 4 slopes was then calculated based on the Horizontal Diffusion Principle. Compared with numerical simulation and full-scale test, calculative width based on Horizontal Diffusion Principle is greater than that based on the code of China (JGJ94-2008) and it decreases by about 3.3 m by every 10° increase of slope. After correcting the calculative width based on Horizontal Diffusion Principle, m-value that can characterize the horizontal resistance of the pile is greater than that based on the code of China (JGJ94-2008); the average difference of two m-values is about 75 MN/m4. Slope has a strong weakening effect on m-value. These conclusions provide a certain reference for the selection of calculative width in engineering