Convolutional neural network-based pose mapping estimation as an alternative to traditional hand-eye calibration.

The vision system is a crucial technology for realizing the automation and intelligence of industrial robots, and the accuracy of hand-eye calibration is crucial in determining the relationship between the camera and robot end. Parallel robots are widely used in automated assembly due to their high positioning accuracy and large carrying capacity, but traditional hand-eye calibration methods may not be applicable due to their limited motion range and resulting accuracy problems. To address this issue, we propose using a pose, nonlinear mapping estimation method to solve the hand-eye calibration problem and have constructed a 1-D pose estimation convolutional neural network (PECNN) with excellent performance, through experiments and discussions. The PECNN achieves an end-to-end mapping of the variation of the target object pose to the variation of the robot end pose. Our experiments have shown that the proposed hand-eye calibration method has high accuracy and can be applied to the automated assembly tasks of vision-guided parallel robots. Moreover, the method is also applicable to most parallel robots and tandem robots.

Improving pose estimation accuracy for large hole shaft structure assembly based on super-resolution.

Image resolution is crucial to visual measurement accuracy, but on the one hand, the cost of increasing the resolution of the acquisition device is prohibitive, and on the other hand, the resolution of the image inevitably decreases when photographing objects at a distance, which is particularly common in the assembly of large hole shaft structures for pose measurement. In this study, a deep learning-based method for super-resolution of large hole shaft images is proposed, including a super-resolution dataset for hole shaft images and a new deep learning super-resolution network structure, which is designed to enhance the perception of edge information in images through the core structure and improve efficiency while improving the effect of image super-resolution. A series of experiments have proven that the method is highly accurate and efficient and can be applied to the automatic assembly of large hole shaft structures.

Epidemiological characteristics, virulence potential, antimicrobial resistance profiles, and phylogenetic analysis of Aeromonas caviae isolated from extra-intestinal infections.

Objective: Aeromonas caviae (A. caviae) is one of the major etiological agents in human intestinal infections reported to be associated with a broad spectrum of extra-intestinal infections with increasing incidence over recent years. Although previous studies have established its significance as a causative agent of both bloodstream and gastrointestinal infections, the characteristics of A. caviae that cause extra-intestinal infections remain unilluminated.In this single-center retrospective study, we investigated epidemiological characteristics, antimicrobial resistance genes and phenotypes, virulence genes, and phyloevolution of 47 clinical A. caviae isolated from patients with extra-intestinal infections from 2017 to 2020. Methods: A. caviae strains were identified by biochemical tests and matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF/MS), ultimately confirmed to species level by whole-genome sequencing (WGS). Antimicrobial resistance and virulence genes were identified using the Comprehensive Antibiotic Resistance Database (CARD) and the virulence factor database (VFDB), respectively. Phylogenetic analysis of 47 clinical strains was performed by combining with 521 A. caviae strains from NCBI database. Results: A. caviae was an opportunistic pathogen in immunocompromised patients, especially those with underlying hepatobiliary diseases and malignancies. 19 out of 47 isolates were identified as multidrug resistance (MDR) strains. Piperacillin-tazobactam, levofloxacin, gentamicin, amikacin with a resistance rate of less than 10% remained as options to treat extra-intestinal infections. 24 out of 47 isolates exhibited non-susceptibility to cephalosporins and cephamycins, all of which carried ß-lactamase gene, including bla MOX, bla PER-3, bla OXA, bla NDM, and bla CphA. Most stains (98%, 46/47) carried at least one of the virulence genes, but extra-intestinal infections had a low mortality rate. Phylogenetic analysis indicated the risk of nosocomial transmission but revealed no outbreak. However, the emergence of MDR and ß-lactamase resistance genes in extra-intestinal isolates of A. caviae is becoming an increasing risk to public health and requires attention. Conclusions: This study strengthen our understanding of A.caviae isolated from extra-intestinal infections. It may contribute to the management of extra-intestinal infections as well as the prevention and control of drug resistance.

Mitochondrial division inhibitor 1 protects cortical neurons from excitotoxicity: a mechanistic pathway.

Mitochondrial division inhibitor 1 (Mdivi-1) is a selective cell-permeable inhibitor of dynamin-related protein-1 (Drp1) and mitochondrial division. To investigate the effect of Mdivi-1 on cells treated with glutamate, cerebral cortex neurons isolated from neonatal rats were treated with 10 mM glutamate for 24 hours. Normal cultured cells and dimethyl sulfoxide-cultured cells were considered as controls. Apoptotic cells were detected by flow cytometry. Changes in mitochondrial morphology were examined by electron microscopy. Drp1, Bax, and caspase-3 expression was evaluated by western blot assays and immunocytochemistry. Mitochondrial membrane potential was detected using the JC-1 probe. Twenty-four hours after 10 mM glutamate treatment, Drp1, Bax and caspase-3 expression was upregulated, Drp1 and Bax were translocated to mitochondria, mitochondrial membrane potential was decreased and the rate of apoptosis was increased. These effects were inhibited by treatment with 50 µM Mdivi-1 for 2 hours. This finding indicates that Mdivi-1 is a candidate neuroprotective drug that can potentially mitigate against neuronal injury caused by glutamate-induced excitotoxicity.

Magnetic resonance imaging: A possible alternative to a standing lateral radiograph for evaluating cervical sagittal alignment in patients with cervical disc herniation?

BACKGROUND AND OBJECTIVES: Convincing evidence supporting the use of magnetic resonance imaging (MRI) as an effective tool for evaluating cervical sagittal alignment is lacking. This study aims to analyze the differences and correlations between cervical sagittal parameters on x-ray and MRI in patients with cervical disc herniation and to determine whether MRI could substitute for cervical x-ray for measurement of cervical sagittal parameters. METHODS: One hundred forty-three adults with cervical disc herniation were recruited. Each patient had both an x-ray and MRI examination of the cervical spine. The cervical sagittal parameters were measured and compared on x-ray and MRI including: C2-C7 Cobb angle, C2-C7 sagittal vertical axis (C2-C7 SVA), cervical tilt (CT), T1 Slope (T1S), and neck tilt (NT). The data were analyzed using a paired-samples t test, a Pearson correlation test, and linear regression. RESULTS: The values of C2-C7 Cobb angle, C2-C7 SVA, CT and T1S on X-ray were larger than those on MRI (P < .05) and NT on X-ray was smaller than that on MRI (P < .05). Each of the cervical sagittal parameters had a significant correlation with the corresponding one on MRI (r = 0.699, 0.585, 0.574, 0.579 and 0.613, respectively) (C2-C7 Cobb MRI = 0.957 + 0.721 C2-C7 Cobb X, C2-C7 SVA MRI = 6.423 + 0.500 C2-C7 SVAX, CT MRI = 3.121 + 0.718 CTX, T1S MRI = 7.416 + 0.613 T1SX, NT MRI = 22.548 + 0.601 NTX). CONCLUSION: Although MRI and x-ray measurements of cervical sagittal parameters were different, there were significant correlations between the results. MRI could be used to evaluate the sagittal balance of the cervical spine with great reliability.