Loop closure can effectively eliminate the accumulated error and plays an important role in Simultaneous Localization and Mapping (SLAM). There remains challenges in loop detection and loop correction due to the large viewpoints difference and the environment appearance changes. In this letter, we propose a novel loop closure method based on object modeling and semantic graph matching. We use voxels and cuboids to model the object-level features in the environment, and further represent the environment as a semantic graph with topological information. On this basis, an efficient graph matching method based on edit distance is proposed for robust place recognition. Finally, the loop correction is carried out by object alignment between semantic maps. Experimental results demonstrate that the proposed method can realize omni-directional loop closure without viewpoint constraint, and is robust to environmental appearance changes. Compared with the existing appearance-based methods, the performance has been greatly improved.

Purpose. To evaluate the effects and mechanism of exogenous hyaluronate (HA) in promoting corneal wound healing.Methods. Human corneal epithelial cells (HCECs) were incubated with different concentrations of HA to evaluate their efficiency in promoting cell migration and their modulation of repair factors. After inducing hyperosmolar conditions, the cell morphologies, cell apoptosis, and expression levels of TNF-αand MMP-9 were detected to assess the protective role of HA. Corneal epithelium-injured rat models were established to test the therapeutic effects of 0.3% HA. Then, the wound healing rates, the RNA expression levels of inflammatory cytokines, and repair factors were examined.Results. HCECs in the 0.03% and 0.3% HA groups showed fewer morphological alterations and lower rates of cell apoptosis following preincubation with HA under hyperosmolar conditions, as well as the expression levels of MMP-9 and TNF-α. In the rat model, the areas of fluorescein staining in the corneas of 0.3% HA group were significantly smaller than the control group. The expression levels of IL-1βand MMP-9 were decreased, while CD44 and FN were increased in the 0.3% HA group.Conclusion. HA enhanced corneal epithelial cell wound healing by promoting cell migration, upregulating repair responses, and suppressing inflammatory responses.

Purpose: The aim of this study was to investigate the differences in anxiety and depression between adolescents with myopia and those with normal vision and to examine the relationship between the level of anxiety and depression and the degree of myopia.Methods: A total of 1,103 first‐year high school students aged 14–17 years were included in the study. The study group comprised 916 persons with myopia, while the control group comprised 187 persons without refractive error. Volunteers underwent routine eye examinations and completed a set of questionnaires about anxiety and depression. Then, the Self‐Rating Anxiety Scale (SAS) and Self‐Rating Depression Scale (SDS) scores were compared between groups, and the relationships between anxiety and the degree of myopia and between depression and the degree of myopia were analyzed.Results: There was a significant difference in anxiety rate between the students with normal vision and those with myopia. The SAS scores among students with mild, moderate, and severe myopia were also significantly different. However, compared with the students with normal vision, the rate of depression was not significantly increased in the students with myopia, except in cases of severe myopia. Additionally, the SAS scores correlated closely with the diopters of the participants’ glasses (r = 0.43, p = .045), while the relationship between SDS scores and the diopters of glasses was not significant (r = 0.19, p = .325).Conclusion: There was a correlation between myopia and mental health in adolescent students, especially in terms of anxiety.

Objects in environments are more stable than feature points, which can benefit for building a wide range of common view relationship and effectively reduce the cumulative error of visual localization. In this paper, we propose Contour-SLAM, the first RGB-D object-level SLAM method that utilizes the projection constraints between the dense object model and its instance masks for state estimation. Firstly, considering that the unstructured object models are difficult to describe mathematically and their re-projection errors are difficult to quantify, we use voxels and cuboids to model objects and define the re-projection error between the 3D object model and its 2D instance segmentation mask based on the outer contour distance. Secondly, we construct a covisibility graph between keyframes based on the shared observations of same feature points and objects, which is further used to maintain a local map including keyframes, map points and object models in real-time. Finally, a multi-view bundle adjustment formulation is proposed to jointly optimize the three components of the local map. Experimental results on public dataset as well as our own collected sequences demonstrate that object modeling and camera pose estimation can benefit each other. The proposed method demonstrates competitive performance compared with the state-of-the-art SLAM methods.

Pterygium is an invasive ocular surface disease characterized by proliferation, inflammatory infiltrates, fibrosis, angiogenesis, and extracellular matrix breakdown. It is a common disorder of the ocular surface, with a prevalence of 2% in temperate areas and up to 20% in tropical regions.¹ The pathogenesis of pterygia has intrigued researchers for centuries, but it is not completely understood. Studies have shown an increasing prevalence of pterygia with closer proximity to the equator, secondary to greater exposure to UV radiation.^2,3 Coroneo et al^4-6 proposed an initial alteration of limbal stem cells as a result of chronic UV exposure, with a resultant breakdown of the limbal barrier leading to conjunctivalization of the cornea. Recently, more direct proof of the hypothesis that pterygia develop from limbal epithelial progenitors has been provided with evidence that Fuchs islet cells have stem cell characteristics.⁷ Other investigators have proposed neoplastic factors, focusing on the p53 tumor suppressor gene,^8,9 whereas some believe tear film abnormalities and allergic factors are significant contributors.¹⁰