Global 3D non-rigid registration of deformable objects using a single RGB-D camera

We present a novel global non-rigid registration method for dynamic 3D objects. Our method allows objects to undergo large non-rigid deformations, and achieves high quality results even with substantial pose change or camera motion between views. In addition, our method does not require a template prior and uses less raw data than tracking based methods since only a sparse set of scans is needed. We compute the deformations of all the scans simultaneously by optimizing a global alignment problem to avoid the well-known loop closure problem, and use an as-rigid-as-possible constraint to eliminate the shrinkage problem of the deformed shapes, especially near open boundaries of scans. To cope with large-scale problems, we design a coarse-to-fine multi-resolution scheme, which also avoids the optimization being trapped into local minima. The proposed method is evaluated on public datasets and real datasets captured by an RGB-D sensor. Experimental results demonstrate that the proposed method obtains better results than several state-of-the-art methods

Label-free and sensitive determination of toxic Cd(II) in environmental waters using a Fe3O4-PEI-Au based electrochemical aptasensor

A novel electrochemical strategy was presented using gold nanoparticles decorated on polyethyleneimine-modified iron oxide nanoparticles (Fe3O4-PEI-Au) as a nanocomposite modifier for sensitive and selective detection of Cd(II). The aptasensor was fabricated by immobilizing a thiol-terminated Cd(II) aptamer onto a screen-printed carbon electrode modified with the Fe3O4-PEI-Au nanocomposite. This nanocomposite provided high surface area for enhanced aptamer loading, excellent biocompatibility, and good conductivity to promote the signal amplification at the sensing interface. Differential pulse voltammetry was used for quantitative measurement of Cd(II), demonstrating a dynamic linear detection range from 0.04 nM to 25 nM. The limit of detection was found to be 0.01 nM, which is lower than the safe limit in drinking water defined by the U.S. Environmental Protection Agency. The label-free aptasensor showed high selectivity, reproducibility, stability and reliability for real-time Cd(II) monitoring in environmental water samples. This work successfully demonstrates the development of a novel electrochemical aptasensor utilizing a Fe3O4-PEI-Au nanocomposite modifier for sensitive and selective detection of trace levels of Cd(II) in water resources

A Coarse-to-Fine Registration Strategy for Multi-Sensor Images with Large Resolution Differences

Automatic image registration for multi-sensors has always been an important task for remote sensing applications. However, registration for images with large resolution differences has not been fully considered. A coarse-to-fine registration strategy for images with large differences in resolution is presented. The strategy consists of three phases. First, the feature-base registration method is applied on the resampled sensed image and the reference image. Edge point features acquired from the edge strength map (ESM) of the images are used to pre-register two images quickly and robustly. Second, normalized mutual information-based registration is applied on the two images for more accurate transformation parameters. Third, the final transform parameters are acquired through direct registration between the original high- and low-resolution images. Ant colony optimization (ACO) for continuous domain is adopted to optimize the similarity metrics throughout the three phases. The proposed method has been tested on image pairs with different resolution ratios from different sensors, including satellite and aerial sensors. Control points (CPs) extracted from the images are used to calculate the registration accuracy of the proposed method and other state-of-the-art methods. The feature-based preregistration validation experiment shows that the proposed method effectively narrows the value range of registration parameters. The registration results indicate that the proposed method performs the best and achieves sub-pixel registration accuracy of images with resolution differences from 1 to 50 times

Advances in the axenic isolation methods of Blastocystis sp. and their applications

Blastocystis sp. is a prevalent protistan parasite found globally in the gastrointestinal tract of humans and various animals. This review aims to elucidate the advancements in research on axenic isolation techniques for Blastocystis sp. and their diverse applications. Axenic isolation, involving the culture and isolation of Blastocystis sp. free from any other organisms, necessitates the application of specific media and a series of axenic treatment methods. These methods encompass antibiotic treatment, monoclonal culture, differential centrifugation, density gradient separation, micromanipulation and the combined use of culture media. Critical factors influencing axenic isolation effectiveness include medium composition, culture temperature, medium characteristics, antibiotic type and dosage and the subtype (ST) of Blastocystis sp. Applications of axenic isolation encompass exploring pathogenicity, karyotype and ST analysis, immunoassay, characterization of surface chemical structure and lipid composition and understanding drug treatment effects. This review serves as a valuable reference for clinicians and scientists in selecting appropriate axenic isolation methods