Joint Intrinsic and Extrinsic LiDAR-Camera Calibration in Targetless Environments Using Plane-Constrained Bundle Adjustment

This paper introduces a novel targetless method for joint intrinsic and extrinsic calibration of LiDAR-camera systems using plane-constrained bundle adjustment (BA). Our method leverages LiDAR point cloud measurements from planes in the scene, alongside visual points derived from those planes. The core novelty of our method lies in the integration of visual BA with the registration between visual points and LiDAR point cloud planes, which is formulated as a unified optimization problem. This formulation achieves concurrent intrinsic and extrinsic calibration, while also imparting depth constraints to the visual points to enhance the accuracy of intrinsic calibration. Experiments are conducted on both public data sequences and self-collected dataset. The results showcase that our approach not only surpasses other state-of-the-art (SOTA) methods but also maintains remarkable calibration accuracy even within challenging environments. For the benefits of the robotics community, we have open sourced our codes

Experimental Investigation of the Performance of a Tuned Heave Plate Energy Harvesting System for a Semi-Submersible Platform

Heave plates are widely used for improving the sea keeping performance of ocean structures. In this paper, a novel tuned heave plate energy harvesting system (THPEH) is presented for the motion suppression and energy harvesting of a semi-submersible platform. The heave plates are connected to the platform though a power take-off system (PTO) and spring supports. The performance of the THPEH was investigated through forced oscillation tests of a 1:20 scale model. Firstly, the hydrodynamic parameters of the heave plate were experimentally studied under different excitation motion conditions, and a force model of the power take-off system was also established through a calibration test. Then, the motion performance, control performance, and energy harvesting performance of the THPEH subsystem were systematically studied. The effects of the tuned period and PTO damping on the performance of the THPEH were analyzed. Finally, a comparison between the conventional fixed heave plate system and THPEH was carried out. The results show that a properly designed THPEH could consume up to 2.5 times the energy from the platform motion compared to the fixed heave plate system, and up to 80% of the consumed energy could be captured by the PTO system. This indicates that the THPEH could significantly reduce the motion of the platform and simultaneously provide considerable renewable energy to the platform

Maresin1 Suppresses High-Glucose-Induced Ferroptosis in Osteoblasts via NRF2 Activation in Type 2 Diabetic Osteoporosis

Maresin1 (MaR1) is an endogenous pro-resolving lipid mediator produced from polyunsaturated fatty acids and is believed to have antioxidant and anti-inflammatory properties. The objective of this study was to estimate MaR1′s impact on type 2 diabetic osteoporosis (T2DOP) and its pharmacological mode of action. An in vitro high-glucose model of the osteoblast cell line MC3T3-E1 was constructed and stimulated with MaR1. Type 2 diabetic rats were used to establish in vivo models of calvarial defects and were treated in situ with MaR1. The results revealed that, aside from preventing mortality and promoting the osteogenic capacity of MC3T3-E1 cells, MaR1 increased nuclear factor erythroid-2 related factor 2 (NRF2) signaling as well as the activity of glutathione peroxidase 4 (GPX4) and cystine-glutamate antiporter (SLC7A11) and caused the restraint of ferroptosis under hyperglycemic stimulation. However, the therapeutic impact of MaR1 was significantly diminished due to NRF2-siRNA interference and the ferroptosis activator Erastin. Meanwhile, these results were validated through in vivo experiments. These findings imply that MaR1 activated the NRF2 pathway in vivo and in vitro to alleviate high-glucose-induced ferroptosis greatly. More crucially, MaR1 might effectively reduce the risk of T2DOP

Clinical evaluation of radiation-induced sinusitis by MRI-based scoring system in nasopharyngeal carcinoma patients

Abstract Objective To explore the application of magnetic resonance imaging (MRI) in the evaluation of radiation-induced sinusitis (RIS), MRI-based scoring system was used to evaluate the development regularity, characteristics and influencing factors of RIS in nasopharyngeal carcinoma (NPC) patients. Patients and methods A retrospective analysis was performed by collecting the clinical and MRI data of 346 NPC patients to analyze the characteristics and prognosis of RIS. The predictive model was constructed according to the influencing factors of RIS. Results (1) In the 2-year follow-up after radiotherapy (RT), there was significant change in L-M score in both groups of NPC patients (sinusitis before RT group: p = 0.000 vs. non-sinusitis before RT group: p = 0.000). After 6 months of RT, the L-M scores of the two groups tended to plateau (sinusitis before RT group: p = 0.311 vs. non-sinusitis before RT group: p = 0.469). (2) The prevalence of sinusitis in two groups of NPC patients (without or with sinusitis before RT) was 83% vs. 93%, 91% vs. 99%, 94% vs. 98% at 1, 6 and 24 months after RT, respectively. (3) In the patients without sinusitis before RT, the incidence of sinusitis in maxillary and anterior/posterior ethmoid, sphenoid and frontal sinuses was 87.1%, 90.0%/87.1%, 49.5%, 11.8% respectively, 1 month after RT. (4) A regression model was established according to the univariate and multivariate analysis of the factors related to RIS (smoking history: p = 0.000, time after RT: p = 0.008 and TNM staging: p = 0.040). Conclusion (1) RIS is a common complication in NPC patients after RT. This disorder progressed within 6 months after RT, stabilized and persisted within 6 months to 2 years. There is a high incidence of maxillary sinus and ethmoid sinus inflammation in NPC patients after RT. (2) Smoking history, time after RT and TNM staging were significant independent risk factors for RIS. (3) The intervention of the risk factors in the model may prevent or reduce the occurrence of RIS in NPC patients

HIV-1 Nef-induced lncRNA AK006025 regulates CXCL9/10/11 cluster gene expression in astrocytes through interaction with CBP/P300

Abstract Background HIV-associated neurocognitive disorder (HAND) is a neurodegenerative disease associated with persistent neuroinflammation and subsequent neuron damage. Pro-inflammatory factors and neurotoxins from activated astrocytes by HIV-1 itself and its encoded proteins, including the negative factor (Nef), are involved in the pathogenesis of HAND. This study was designed to find potential lncRNAs that regulate astrocyte functions and inflammation process. Methods We performed microarray analysis of lncRNAs from primary mouse astrocytes treated with Nef protein. Top ten lncRNAs were validated through real-time PCR analysis. Gene ontology (GO) and KEGG pathway analysis were applied to explore the potential functions of lncRNAs. RIP and ChIP assays were performed to demonstrate the mechanism of lncRNA regulating gene expression. Results There were 638 co-upregulated lncRNAs and 372 co-downregulated lncRNAs in primary astrocytes treated with Nef protein for both 6 h and 12 h. GO and KEGG pathway analysis showed that the biological functions of top differential-expressed mRNAs were associated with inflammatory cytokines and chemokine. Knockdown of lncRNA AK006025, not AK138360, inhibited significantly CXCL9, CXCL10 (IP-10), and CXCL11 expression in astrocytes treated with Nef protein. Mechanism study showed that AK006025 associated with CBP/P300 was enriched in the promoter of CXCL9, CXCL10, and CXCL11 genes. Conclusions Our findings uncovered the expression profiles of lncRNAs and mRNAs in vitro, which might help to understand the pathways that regulate astrocyte activation during the process of HAND

Analysis of Long Noncoding RNA and mRNA Expression Profiles in IL-9-Activated Astrocytes and EAE Mice

Background/Aims: Multiple sclerosis (MS) is an autoimmune disease in the central nervous system associated with demyelination and axonal injury. Astrocyte activation is involved in the pathogenesis of MS and experimental autoimmune encephalomyelitis (EAE), an animal model of MS. This study was designed to find potential lncRNAs in EAE mice and activated astrocytes. Methods: we performed microarray analysis of lncRNAs from the brain tissues of EAE mice and primary mouse astrocytes treated with IL-9(50 ng/ml). 12 lncRNAs were validated through real-time PCR. Gene ontology and KEGG pathway analysis were applied to explore the potential functions of lncRNAs. Results: Differentially expressed 3300 lncRNAs and 3250 mRNAs were in the brain tissues of EAE mice, and 3748 lncRNAs and 3332 mRNAs were in activated astrocytes. Notably, there were 2 co-up-regulated lncRNAs and 3 co-down-regulated lncRNAs both in the brain tissues of EAE mice and in activated astrocytes, including Gm14005, Gm12478, mouselincRNA1117, AK080435, and mouselincRNA0681, which regulate the ER calcium flux kinetics, zinc finger protein and cell apoptosis. Similarly, there were 7 mRNAs co-up-regulated and 2 mRNAs co-down-regulated both in vivo and in vitro. Gene ontology and KEGG pathway analysis showed that the biological functions of differentially expressed mRNAs were associated with metabolism, development and inflammation. The results of realtime PCR validation were consistent with the data from the microarrays. Conclusions: Our data uncovered the expression profiles of lncRNAs and mRNAs in vivo and in vitro, which may help delineate the mechanisms of astrocyte activation during MS/EAE process