Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 41
Filter
1.
Insect Sci ; 2024 Jun 04.
Article in English | MEDLINE | ID: mdl-38837613

ABSTRACT

A systems biology approach was employed to gain insight into tick biology and interactions between vectors and pathogens. Haemaphysalis longicornis serves as one of the primary vectors of Babesia microti, significantly impacting human and animal health. Obtaining more information about their relationship is crucial for a comprehensive understanding of tick and pathogen biology, pathogen transmission dynamics, and potential control strategies. RNA sequencing of uninfected and B. microti-infected ticks resulted in the identification of 15 056 unigenes. Among these, 1 051 were found to be differentially expressed, with 796 being upregulated and 255 downregulated (P < 0.05). Integrated transcriptomics datasets revealed the pivotal role of immune-related pathways, including the Toll, Janus kinase/signal transducer and activator of transcription (JAK-STAT), immunodeficiency, and RNA interference (RNAi) pathways, in response to infection. Consequently, 3 genes encoding critical transcriptional factor Dorsal, Relish, and STAT were selected for RNAi experiments. The knockdown of Dorsal, Relish, and STAT resulted in a substantial increase in Babesia infection levels compared to the respective controls. These findings significantly advanced our understanding of tick-Babesia molecular interactions and proposed novel tick antigens as potential vaccine targets against tick infestations and pathogen transmission.

2.
Front Bioeng Biotechnol ; 12: 1353797, 2024.
Article in English | MEDLINE | ID: mdl-38375455

ABSTRACT

Objective: Compare the spine's stability after laminectomy (LN) and laminoplasty (LP) for two posterior surgeries. Simultaneously, design a new vertebral titanium porous mini plate (TPMP) to achieve firm fixation of the open-door vertebral LP fully. The objective is to enhance the fixation stability, effectively prevent the possibility of "re-closure," and may facilitate bone healing. Methods: TPMP was designed by incorporating a fusion body and porous structures, and a three-dimensional finite element cervical model of C2-T1 was constructed and validated. Load LN and LP finite element models, respectively, and analyze and simulate the detailed processes of the two surgeries. It was simultaneously implanting the TPMP into LP to evaluate its biomechanical properties. Results: We find that the range of motion (ROM) of C4-C5 after LN surgery was greater than that of LP implanted with different plates alone. Furthermore, flexion-extension, lateral bending, and axial rotation reflect this change. More noteworthy is that LN has a much larger ROM on C2-C3 in axial rotation. The ROM of LP implanted with two different plates is similar. There is almost no difference in facet joint stress in lateral bending. The facet joint stress of LN is smaller on C2-C3 and C4-C5, and larger more prominent on C5-C6 in the flexion-extension. Regarding intervertebral disc pressure (IDP), there is little difference between different surgeries except for the LN on C2-C3 in axial rotation. The plate displacement specificity does not significantly differ from LP with vertebral titanium mini-plate (TMP) and LP with TPMP after surgery. The stress of LP with TPMP is larger in C4-C5, C5-C6. Moreover, LP with TMP shows greater stress in the C3-C4 during flexion-extension and lateral bending. Conclusion: LP may have better postoperative stability when posterior approach surgery is used to treat CSM; at the same time, the new type of vertebral titanium mini-plate can achieve almost the same effect as the traditional titanium mini-plate after surgery for LP. In addition, it has specific potential due to the porous structure promoting bone fusion.

3.
Front Endocrinol (Lausanne) ; 14: 1277153, 2023.
Article in English | MEDLINE | ID: mdl-38075067

ABSTRACT

Objective: To investigate the causal relationships between linoleic acid and type 2 diabetes, and between linoleic acid and glycemic traits in European populations. Methods: This study employed a two-sample Mendelian randomization approach to infer causality between linoleic acid and type 2 diabetes, as well as between linoleic acid and glycemic traits, leveraging genetic variations. Data were sourced from genome-wide association study summary datasets. Random-effects inverse-variance weighted, weighted median, and MR-Egger methods were used for the two-sample Mendelian randomization analyses. Results were presented as odds ratios with a 95% confidence interval. Multiple sensitivity analyses were conducted to assess result robustness. Results: MR findings indicated a correlation between linoleic acid levels and the risk of type 2 diabetes, fasting blood glucose, and glycated hemoglobin (HbA1c), but not with fasting insulin. Specifically: type 2 diabetes (OR: 0.811, 95% CI: 0.688-0.956, P=0.013<0.05),fasting blood glucose (ß_IVW): -0.056, 95% CI: (-0.091,-0.021), P=0.002< 0.0125), glycated hemoglobin (ß_IVW: -0.032, 95% CI: (-0.048,-0.015), P=0.0002< 0.0125) and Fasting insulin (ß_IVW: -0.024, 95% CI: (-0.056,-0.008), P=0.136 >0.05).Reverse MR analyses showed a correlation between type 2 diabetes and reduced levels of linoleic acid (ß_IVW: -0.033, 95% CI: (-0.059,-0.006), P=0.014<0.05). Multiple sensitivity analyses also detected study heterogeneity but found no evidence of horizontal pleiotropy. Conclusion: High levels linoleic acid can reduce the risk of type 2 diabetes, fasting blood glucose, and glycated hemoglobin, but has no significant relation with fasting insulin. Type 2 diabetes can lower linoleic acid levels; however, no significant causal relationship was observed between the three glycemic traits and reduced levels of linoleic acid.


Subject(s)
Diabetes Mellitus, Type 2 , Linoleic Acid , Humans , Blood Glucose , Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/genetics , Genome-Wide Association Study , Glycated Hemoglobin , Insulin , Mendelian Randomization Analysis
4.
Biomimetics (Basel) ; 8(7)2023 Oct 26.
Article in English | MEDLINE | ID: mdl-37999151

ABSTRACT

For a long time, fish school swimming has attracted a great deal of attention in biological systems, as fish schools can have complex hydrodynamic effects on individuals. This work adopted a non-iterative, immersed boundary-lattice Boltzmann method (IB-LBM). A numerical simulation of two-dimensional three-degree-of-freedom self-propelled fish, in side-by-side, staggered, and triangle formations, was conducted by adjusting spacing and motion parameters. A comprehensive analysis of individual speed gains and energy efficiencies in these formations was carried out. Furthermore, an analysis of the hydrodynamic characteristics of fish schools was performed, using instantaneous vorticity profiles and pressure fields. Certain studies have shown that passive interactions between individuals cannot always bring hydrodynamic benefits. The swimming efficiency of side-by-side formations in the same phase gradually increases as the distance decreases, but it also brings certain burdens to individuals when the phases are different. This paper also shows that the roles of passive interactions, spacing, and deflections affect fish school subsystems differently. When the low-pressure areas created by a wake vortex act on one side of an individual's body, the tail-end fish are good at gaining hydrodynamic benefits from it. This effect is not universal, and the degree to which individuals benefit from changes in exercise parameters varies. This study provides a theoretical basis for bioinspired robots, as well as providing certain insights into the mechanism of collective biological movement.

5.
Waste Manag ; 172: 127-139, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-37913690

ABSTRACT

Minimizing the environmental impact of zinc-bearing dust and sludge (ZDS) while efficiently extracting valuable metals from its intricate mix has become a pressing issue for steel mills. To facilitate comprehensive ZDS usage, we propose a novel approach for recycling ZDS in the blast furnace main trough. This work explores the self-reduction reaction principles of carbon-containing pellets derived from ZDS. Moreover, it examines the consequent alterations in the physical and chemical properties of molten iron and slag. The molten iron temperature inversely correlates with the number of added pellets; the temperature declines as more pellets are introduced. To restrict the molten iron's temperature decrease to within 30℃, it is advisable to limit the quantity of pellets added to 20 kg per ton of molten iron. At 1500℃, the self-reduction reaction of the pellet initiates 1.5 min post its introduction into the molten iron and concludes 12 min thereafter. The pellet mass percentage entering the molten iron is 32 %, whereas the mass percentage of iron elements within the pellet entering molten iron is 64 %. The pellet addition results in an uptick in blast furnace slag viscosity, yet it remains within an acceptable viscosity range (<1Pa·s).


Subject(s)
Sewage , Zinc , Zinc/chemistry , Dust , Metals , Iron
6.
Front Neurorobot ; 17: 1277160, 2023.
Article in English | MEDLINE | ID: mdl-37954492

ABSTRACT

Common RGBD, CMOS, and CCD-based cameras produce motion blur and incorrect exposure under high-speed and improper lighting conditions. According to the bionic principle, the event camera developed has the advantages of low delay, high dynamic range, and no motion blur. However, due to its unique data representation, it encounters significant obstacles in practical applications. The image reconstruction algorithm based on an event camera solves the problem by converting a series of "events" into common frames to apply existing vision algorithms. Due to the rapid development of neural networks, this field has made significant breakthroughs in past few years. Based on the most popular Events-to-Video (E2VID) method, this study designs a new network called E2VIDX. The proposed network includes group convolution and sub-pixel convolution, which not only achieves better feature fusion but also the network model size is reduced by 25%. Futhermore, we propose a new loss function. The loss function is divided into two parts, first part calculates the high level features and the second part calculates the low level features of the reconstructed image. The experimental results clearly outperform against the state-of-the-art method. Compared with the original method, Structural Similarity (SSIM) increases by 1.3%, Learned Perceptual Image Patch Similarity (LPIPS) decreases by 1.7%, Mean Squared Error (MSE) decreases by 2.5%, and it runs faster on GPU and CPU. Additionally, we evaluate the results of E2VIDX with application to image classification, object detection, and instance segmentation. The experiments show that conversions using our method can help event cameras directly apply existing vision algorithms in most scenarios.

7.
Front Neurorobot ; 16: 928206, 2022.
Article in English | MEDLINE | ID: mdl-35928729

ABSTRACT

The AUV (Autonomous Underwater Vehicle) navigation process relies on the interaction of a variety of sensors. The side-scan sonar can collect underwater images and obtain semantic underwater environment information after processing, which will help improve the ability of AUV autonomous navigation. However, there is no practical method to utilize the semantic information of side scan sonar image. A new convolutional neural network model is proposed to solve this problem in this paper. The model is a standard codec structure, which extracts multi-channel features from the input image and then fuses them to reduce parameters and strengthen the weight of feature channels. Then, a larger convolution kernel is used to extract the features of large-scale sonar images more effectively. Finally, a parallel compensation link with a small-scale convolution kernel is added and spliced with features extracted from a large convolution kernel in the decoding part to obtain features of different scales. We use this model to conduct experiments on self-collected sonar data sets, which were uploaded on github. The experimental results show that ACC and MIoU reach 0.87 and 0.71, better than other classical small-order semantic segmentation networks. Furthermore, the 347.52 g FOLP and the number of parameters around 13 m also ensure the computing speed and portability of the network. The result can extract the semantic information of the side-scan sonar image and assist with AUV autonomous navigation and mapping.

8.
Dalton Trans ; 51(29): 10992-11004, 2022 Jul 26.
Article in English | MEDLINE | ID: mdl-35791747

ABSTRACT

A novel type II BiOCl/CAU-17 2D/2D heterostructure photocatalyst was synthesized by in situ growth of ultrathin BiOCl on the surface of CAU-17 nanorods through a solvothermal process. The 2D/2D heterostructures endow the BiOCl/CAU-17 heterojunction with a large specific surface area and tight interfacial contact, which can provide sufficient channels for carrier migration. The introduction of CAU-17 can enhance the light absorption ability of BiOCl/CAU-17 photocatalysts. Furthermore, the staggered type II heterostructure energy band alignment formed between BiOCl and CAU-17 can promote the separation of photoexcited carriers. The improved performance for carrier migration and light absorption was evaluated by SEM, TEM, BET, EIS, and DRS tests. Transient photocurrent response and photoluminescence tests confirmed the improvement in separating photoexcited carriers. The optimal 70% BiOCl/CAU-17 sample exhibited the highest photocatalytic degradation efficiency of 96.3% for RhB and 85.5% for TC, under 90 min of simulated solar light irradiation. Its apparent first-order rate constant k values are 0.02947 and 0.01955 min-1, respectively, being 48.31 and 19.75 fold higher than those of CAU-17, and 7.61 and 1.84 fold higher than those of BiOCl. The free radical scavenging experiment results showed that h+ and ˙O2- are the prime active species during the photodegradation process. Hence, a possible photocatalytic mechanism of the type II BiOCl/CAU-17 heterojunction was proposed.

9.
J Colloid Interface Sci ; 625: 664-679, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35764046

ABSTRACT

A 2D/2D BiOIO3/BiOBr Z-scheme heterostructure was firstly synthesized by a simple one-pot hydrothermal process and it was used to effectively remove rhodamine B under irradiation of Xe and LED light. The BB-15 heterostructure has an optimal apparent rate constant k of 0.046 min-1 (0.17 min-1), which is ∼6.2 (89.7) and 3.5 (3.5) times that of BiOIO3 and BiOBr under the irradiation of Xe light (LED light). The enhanced photocatalytic activity can be attributed to the following points: (1) the face-to-face and tight contact in 2D/2D BiOIO3/BiOBr heterostructures provides more migration channels for photogenerated carriers which facilitates the transfer and separation of photogenerated carriers; (2) the Z-scheme photocarrier transport path not only hastens the separation and transfer efficiency of photocarriers in space but also maintains a robust redox capacity; (3) the presence of IO3-/I- redox couple and built-in electric field further encourage the separation and transfer of photocarriers and enhance the photocatalytic activity of the composite. And the O2-, h+, and OH are active species, which are responsible for the photodegrade process of RhB under irradiation of Xe light. This study provided an easy and reliable strategy to design and prepare an efficient bismuth-containing heterojunction, the characterization and evaluation experiment results proved its effectiveness for solar utilization and environmental purification.

10.
Front Neurorobot ; 16: 821991, 2022.
Article in English | MEDLINE | ID: mdl-35360831

ABSTRACT

Path planning obtains the trajectory from one point to another with the robot's kinematics model and environment understanding. However, as the localization uncertainty through the odometry sensors is inevitably affected, the position of the moving path will deviate further and further compared to the original path, which leads to path drift in GPS denied environments. This article proposes a novel path planning algorithm based on Dijkstra to address such issues. By combining statistical characteristics of localization error caused by dead-reckoning, the replanned path with minimum cumulative error is generated with uniforming distribution in the searching space. The simulation verifies the effectiveness of the proposed algorithm. In a real scenario with measurement noise, the results of the proposed algorithm effectively reduce cumulative error compared to the results of the conventional planning algorithm.

11.
Opt Express ; 30(4): 5329-5346, 2022 Feb 14.
Article in English | MEDLINE | ID: mdl-35209499

ABSTRACT

Ultra-precision grinding is crucial for manufacturing high-end optics and molds, while the unbalanced wheel vibration is inevitable and becomes even more critical in surface generation, which resulted in undesired waviness and micro-texture on the ground surface. In this paper, to understand and control the micro-texture generation, a theoretical model has been developed to predict the deterministic surface micro-texture generation resulted from unbalanced tool vibration in ultra-precision grinding, in which the overlap trajectories of grinding wheel with an arc cutting edge were analyzed and calculated. The simulation work was performed and a double phase mechanism involved in deterministic textural pattern and structure has been revealed. Both theoretical and experimental results proved that phase shift is an important factor to determine micro-texture evolution in the ultra-precision grinding process. On this basis, a novel tool path strategy has been proposed to fabricate deterministic micro-structure by coordinating oscillation motion of the grinding wheel and phase shift control, in which a rhombus-shaped micro-structure array can be generated. A small adjustment for the phase shift was conducted and it was found that the more complex micro-texture with different textural patterns and micro-structure can be machined. The results indicated that the phase control for the tool path planning is an effective method to fabricate flexible and tunable micro-texture surfaces in ultra-precision grinding.

12.
Altern Ther Health Med ; 28(2): 109-115, 2022 Feb.
Article in English | MEDLINE | ID: mdl-35139492

ABSTRACT

BACKGROUND: One of the serious complications of severe acute pancreatitis (SAP) is acute lung injury (ALI). Suppressing inflammation is a feasible treatment strategy for SAP-induced ALI. Shenmai injection (SMI), which is a Traditional Chinese Medicine (TCM treatment, can suppress inflammation. Therefore, this study used an established SAP rat model to determine the effect of SMI on ALI induced by SAP. METHODS: A total of 40 male Sprague-Dawley (SD) rats were assigned to one of four groups: the SAP group, the sham surgery (SS) group, the SAP + SMI group and the SAP + SMI + zinc protoporphyrin (ZnPP) group. Rats in the SAP group were intravenously injected with 1.6 ml/kg saline 30 minutes after induction of SAP models, rats in the SAP + SMI group were intravenously injected with 1.6 ml/kg SMI, while rats in the SAP + SMI + ZnPP group were intravenously injected with 1.6 ml/kg SMI and 30 mg/kg ZnPP via intraperitoneal injection. The rates were sacrificed 24 hours after SAP induction. Excised lung tissues were histologically examined, protein concentration in bronchoalveolar lavage fluid (BALF) was measured and lung wet-to-dry (W/D) weight ratio was calculated. The protein and mRNA levels of tumor necrosis factor (TNF)-α, heme oxygenase (HO)-1 and interleukin (IL)-10 in blood and tissue samples were measured. RESULTS: SMI treatment attenuated SAP-induced ALI as evidenced by lower lung damage scores compared with the untreated SAP group (P < .05). SMI also abolished the SAP-induced rise in BALF and W/D ratio protein concentrations (P < .05). Moreover, SMI treatment increased HO-1 and IL-10 levels but decreased TNF-α levels in serum and tissue samples (P < .05). However, inhibition of HO-1 expression by ZnPP led to significant inhibition of all the changes. CONCLUSION: SMI can alleviate SAP-induced ALI through HO-1 upregulation.


Subject(s)
Acute Lung Injury , Pancreatitis , Acute Disease , Acute Lung Injury/drug therapy , Animals , Drug Combinations , Drugs, Chinese Herbal , Heme Oxygenase-1 , Male , Pancreatitis/complications , Pancreatitis/drug therapy , Rats , Rats, Sprague-Dawley , Tumor Necrosis Factor-alpha , Up-Regulation
13.
Appl Opt ; 60(23): 6910-6917, 2021 Aug 10.
Article in English | MEDLINE | ID: mdl-34613172

ABSTRACT

Full aperture polishing is a significant process to fabricate optical workpieces with nano figure precision. It has the characteristics of excellent full spectrum uniform removal ability, fast convergence speed, high machining accuracy, and low production cost, which makes it the first choice for the processing of large-aperture optical elements. However, with BK7 glass it is difficult to achieve deterministic processing due to its large thermal expansion coefficient and other factors, and the surface shape accuracy is difficult to improve. In this paper, the thermal deformation of BK7 glass is analyzed first, and then the temperature distribution in the element is measured during full-aperture polishing. The influence of the temperature field in the optics on the accuracy of the final surface shape is analyzed, and the quantitative relationship between the temperature difference and the surface shape is established. In addition, the methods of deterministically controlling the surface shape of optics such as polishing liquid temperature control and immersion polishing are proposed. Finally, the model of quantitative control of the surface shape of optics is verified by experiments, which improve the surface shape accuracy of 600 mm BK7 optics to 0.2λ.

14.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 29(3): 763-771, 2021 Jun.
Article in Chinese | MEDLINE | ID: mdl-34105470

ABSTRACT

OBJECTIVE: To analyze the influence of bone marrow involvement (BMI) in patients with malignant lymphoma (ML) on laboratory indexes, and evaluate the laboratory markers that can be used to predict/diagnose BMI. METHODS: The clinical characteristics and laboratory indexes of 137 ML patients were analyzed retrospectively, from which the indexes of BMI in ML patients was studied. The logistic regression analysis and receiver operating curve (ROC) were used to evaluate independent risk factors and predictors of BMI diagnosis in ML patients. RESULTS: Compared with non-BMI group, the red blood cell distribution width, C-reactive protein, erythrocyte sedimentation rate, D-dimer, lactate dehydrogenase, alkaline phosphatase, ß2-microglobulin, transferrin, CA153, CA125, and soluble interleukin-2 receptor (sIL-2R) levels were increased while platelet (PLT) count was decreased in BMI group, and the difference was statistically significant (P<0.05). The blood indexes related to BMI and the statistically significant indexes in the univariate regression analysis were corrected by multivariate logistic regression analysis. The corrected results showed that T cell-related non-Hodgkin lymphoma (adjusted OR=2.18, 95%CI: 1.48-4.90, P<0.001), clinical stage Ⅲ-Ⅳ (adjusted OR=3.32, 95%CI: 2.16-5.83, P<0.001), sIL-2R (adjusted OR=4.26, 95%CI: 2.95-12.85, P<0.001) were the risk factors for ML patients with BMI, while PLT (adjusted OR=0.89, 95%CI: 0.55-0.96, P= 0.003) was a protective factor. ROC analysis showed that the areas under the ROC curve of PLT and sIL-2R predicting BMI in ML patients was 0.712 (95%CI: 0.646-0.776, P<0.001) and 0.796 (95%CI: 0.739-0.853, P<0.001), respectively. The best cut-off point of PLT and sIL-2R was 160×109/L and 2 568 U/ml, respectively. The diagnostic specificities of the two indexes here were both greater than 80%. CONCLUSION: PLT and sIL2R show good diagnostic value for ML patients with BMI.


Subject(s)
Laboratories , Lymphoma , Bone Marrow , Humans , Prognosis , Retrospective Studies
15.
Virol J ; 18(1): 101, 2021 05 21.
Article in English | MEDLINE | ID: mdl-34020680

ABSTRACT

OBJECTIVE: Coronavirus disease 2019 (COVID-19) is a major challenge facing the world. Certain guidelines issued by National Health Commission of the People's Repubilic of China recommend intravenous immunoglobulin (IVIG) for adjuvant treatment of COVID-19. However, there is a lack of clinical evidence to support the use of IVIG. METHODS: This single-center retrospective cohort study included all adult patients with laboratory-confirmed severe COVID-19 in the Respiratory and Critical Care Unit of Dabie Mountain Regional Medical Center, China. Patient information, including demographic data, laboratory indicators, the use of glucocorticoids and IVIG, hospital mortality, the application of mechanical ventilation, and the length of hospital stay was collected. The primary outcome was the composite end point, including death and the use of mechanical ventilation. The secondary outcome was the length of hospital stay. RESULTS: Of the 285 patients with confirmed COVID-19, 113 severely ill patients were included in this study. Compared to the non-IVIG group, more patients in the IVIG group reached the composite end point [12 (25.5%) vs 5 (7.6%), P = 0.008] and had longer hospital stay periods [23.0 (19.0-31.0) vs 16.0 (13.8-22.0), P < 0.001]. After adjusting for confounding factors, differences in primary outcomes between the two groups were not statistically significant (P = 0.167), however, patients in the IVIG group had longer hospital stay periods (P = 0.041). CONCLUSION: Adjuvant therapy with IVIG did not improve in-hospital mortality rates or the need for mechanical ventilation in severe COVID-19 patients. Our study does not support the use of immunoglobulin in patients with severe COVID-19 patients.


Subject(s)
COVID-19 Drug Treatment , Immunoglobulins, Intravenous/therapeutic use , SARS-CoV-2 , Adult , Aged , COVID-19/mortality , Female , Hospital Mortality , Humans , Male , Middle Aged , Retrospective Studies , Severity of Illness Index
16.
Opt Express ; 29(6): 8041-8063, 2021 Mar 15.
Article in English | MEDLINE | ID: mdl-33820258

ABSTRACT

High-precision optical components with complex shapes or microstructures have been extensively used in numerous fields such as biomedicine, energy and aerospace. In order to accurately achieve the specific functions of the components, the form accuracy and uniform surface quality need to reach an ever-high level. To achieve this, ultra-precision normal grinding is used for machining various types of complex optical surfaces. However, the intricate variation of the workpiece curvature and grinding wheel vibration gives rise to great challenges to obtain higher precision and uniform surface conditions. In this study, the influence of curvature on surface topography generation has been investigated and a novel model of scallop height has been developed for surface topography generation in the normal grinding of the curved surface. In addition, the relative influence of the curvature is analyzed experimentally, in which the micro-waviness generation as a consequence of the unbalanced vibration of the grinding wheel is modeled and validated by experiments. Finally, the micro sinusoidal array with the setting value for scallop height is achieved by controlling the feed speed, which is determined by the local curvature of surface profile. The results indicated that the curvature variation posed a significant effect on surface uniformity and the model is valid to achieve surface scallop height control in the normal grinding effectively.

17.
Front Neurorobot ; 15: 801956, 2021.
Article in English | MEDLINE | ID: mdl-35095458

ABSTRACT

SLAM (Simultaneous Localization And Mapping) plays a vital role in navigation tasks of AUV (Autonomous Underwater Vehicle). However, due to a vast amount of image sonar data and some acoustic equipment's inherent high latency, it is a considerable challenge to implement real-time underwater SLAM on a small AUV. This paper presents a filter based methodology for SLAM algorithms in underwater environments. First, a multi-beam forward looking sonar (MFLS) is utilized to extract environmental features. The acquired sonar image is then converted to sparse point cloud format through threshold segmentation and distance-constrained filtering to solve the calculation explosion issue caused by a large amount of original data. Second, based on the proposed method, the DVL, IMU, and sonar data are fused, the Rao-Blackwellized particle filter (RBPF)-based SLAM method is used to estimate AUV pose and generate an occupancy grid map. To verify the proposed algorithm, the underwater vehicle is equipped as an experimental platform to conduct field tasks in both the experimental pool and wild lake, respectively. Experiments illustrate that the proposed approach achieves better performance in both state estimation and suppressing divergence.

18.
Front Neurorobot ; 15: 815144, 2021.
Article in English | MEDLINE | ID: mdl-35095459

ABSTRACT

In this paper, a circular objects detection method for Autonomous Underwater Vehicle (AUV) docking is proposed, based on the Dynamic Vision Sensor (DVS) and the Spiking Neural Network (SNN) framework. In contrast to the related work, the proposed method not only avoids motion blur caused by frame-based recognition during docking procedure but also reduces data redundancy with limited on-chip resources. First, four coplanar and rectangular constrained circular light sources are constructed as the docking landmark. By combining asynchronous Hough circle transform with the SNN model, the coordinates of landmarks in the image are detected. Second, a Perspective-4-Point (P4P) algorithm is utilized to calculate the relative pose between AUV and the landmark. In addition, a spatiotemporal filter is also used to eliminate noises generated by the background. Finally, experimental results are demonstrated from both software simulation and experimental pool, respectively, to verify the proposed method. It is concluded that the proposed method achieves better performance in accuracy and efficiency in underwater docking scenarios.

19.
J Surg Res ; 256: 295-302, 2020 12.
Article in English | MEDLINE | ID: mdl-32712444

ABSTRACT

BACKGROUND: To explore the mechanism of Shenmai injection (SMI) on severe acute pancreatitis (SAP) through heme oxygenase-1 (HO-1) signaling. METHODS: A total of 40 male Sprague-Dawley (SD) rats (220-260 g) were grouped into the following four categories (n = 10): SAP + SMI + Zinc protoporphyrin (ZnPP), SAP + SMI, SAP, and sham surgery groups. ZnPP is a specific inhibitor of HO-1. Four percent of sodium taurocholate (1 mL/kg) was retrogradely injected via the pancreatic duct to induce the SAP model. The SAP group rats received 1.6 mL/kg saline by intravenous injection 30 min after the induction of SAP. The SAP + SMI group rats received 1.6 mL/kg SMI by intravenous injection 30 min after the induction of SAP. The SAP + SMI + ZnPP group rats received an intravenous injection of 1.6 mL/kg SMI and intraperitoneal administration of 30 mg/kg ZnPP 30 min after the SAP induction. Twenty-four hours after the SAP induction, blood samples were collected for the measurement of amylase, lipase, creatinine, myeloperoxidase, interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α), and HO-1 level, while tissue specimens were harvested for the determination of HO-1, TNF-α, and IL-10 mRNA level. Meanwhile, histopathological changes in organs (pancreas, lung, and kidney) were stored. RESULTS: The serum concentration of amylase, lipase, creatinine, and myeloperoxidase was higher in the SAP group than in the SAP + SMI group. Treatment with SMI increased HO-1 and IL-10 level and reduced TNF-α level in serum and tissues compared to the SAP group (P < 0.05). Treatment with SMI abolished the organ-damaging effects of SAP (P < 0.05). Furthermore, suppression of HO-1 expression by ZnPP canceled the aforementioned effects. CONCLUSIONS: SMI confers protection against the SAP-induced systemic inflammatory response and multiple organs damage via HO-1 upregulation.


Subject(s)
Drugs, Chinese Herbal/administration & dosage , Heme Oxygenase (Decyclizing)/metabolism , Pancreas/drug effects , Pancreatitis/drug therapy , Systemic Inflammatory Response Syndrome/prevention & control , Amylases/blood , Animals , Disease Models, Animal , Drug Combinations , Humans , Lipase/blood , Male , Pancreas/immunology , Pancreas/pathology , Pancreatitis/blood , Pancreatitis/complications , Pancreatitis/diagnosis , Peroxidase/blood , Rats , Severity of Illness Index , Systemic Inflammatory Response Syndrome/blood , Systemic Inflammatory Response Syndrome/diagnosis , Systemic Inflammatory Response Syndrome/etiology , Up-Regulation/drug effects
20.
Front Neurorobot ; 13: 12, 2019.
Article in English | MEDLINE | ID: mdl-31133839

ABSTRACT

This paper proposes a framework for uncertainty prediction in complex fusion networks, where signals become available sporadically. Assuming there is no information of the sensor characteristics available, a surrogated model of the sensor uncertainty is yielded directly from data through artificial neural networks. The strategy developed is applied to autonomous vehicle localization through odometry sensors (speed and orientation), so as to determine the location uncertainty in the trajectory. The results obtained allow for fusion of autonomous vehicle location measurements, and effective correction of the accumulated odometry error in most scenarios. The neural networks applicability and generalization capacity are proven, evidencing the suitability of the presented methodology for uncertainty estimation in non-linear and intractable processes.

SELECTION OF CITATIONS
SEARCH DETAIL