Uptake and toxicity of micro-/nanoplastics derived from naturally weathered disposable face masks in developing zebrafish: Impact of COVID-19 pandemic on aquatic life.

The unprecedented proliferation of disposable face masks during the COVID-19 pandemic, coupled with their improper disposal, threatens to exacerbate the already concerning issue of plastic pollution. This study evaluates the role of environmentally weathered masks as potential sources of microplastics (MPs) and nanoplastics (NPs) and assesses their adverse impact on the early life stages of zebrafish. Experimental findings revealed that a single disposable mask could release approximately 1.79 × 109 particles, with nearly 70% measuring less than 1 µm, following 60 days of sunlight exposure and subsequent sand-induced physical abrasion. Remarkably, the MPs/NPs (MNPs) emanating from face masks have the potential to permeate the outer layer (chorion) of zebrafish embryos. Furthermore, due to their minute size, these particles can be consumed by the larvae's digestive system and subsequently circulated to other tissues, including the brain. Exposure to mask-derived MNPs at concentrations of 1 and 10 µg/L led to significant cases of developmental toxicity, incited oxidative stress, and prompted cell apoptosis. A subsequent metabolomics analysis indicated that the accumulation of these plastic particles perturbed metabolic functions in zebrafish larvae, primarily disrupting amino acid and lipid metabolism. The outcomes of this research underscore the accelerating possibility of environmental aging processes and physical abrasion in the release of MNPs from disposable face masks. Most importantly, these results shed light on the possible ecotoxicological risk posed by improperly disposed of face masks.

Environmentally relevant concentrations of tris (2-chloroethyl) phosphate (TCEP) induce hepatotoxicity in zebrafish (Danio rerio): a whole life-cycle assessment.

Tris (2-chloroethyl) phosphate (TCEP), a typical organophosphate flame retardant, is of increasingly great concern considering their ubiquitous presence in aquatic environments and potential ecotoxicity. The present work was aimed to investigate the potential growth inhibition and hepatic stress induced by whole life-cycle exposure to TCEP (0.8, 4, 20 and 100 µg/L) in zebrafish. The results revealed that the body length, body mass and hepatic-somatic index (HSI) of zebrafish were significantly declined after exposure to TCEP for 120 days. GPx activity and GSH content were increased in the liver of zebrafish treated with low concentrations (0.8 and 4 µg/L) of TCEP, while exposure to high concentrations (20 and 100 µg/L) of TCEP reduced antioxidative capacity and elevated lipid peroxidation (LPO) levels. Gene transcription analysis demonstrated that the mRNA levels of nrf2 were altered in a similar manner to the transcription of the downstream genes nqo1 and hmox1, suggesting that Nrf2-Keap1 pathway mediated TCEP-induced oxidative stress in zebrafish liver. In addition, TCEP exposure might alleviate inflammatory response through down-regulating transcription of inflammatory cytokines (il-1ß, il-6 and inos), and induce apoptosis via activating the p53-Bax pathway. Moreover, whole life-cycle exposure to TCEP caused a series of histopathological anomalies in zebrafish liver. Overall, our results revealed that lifetime exposure to environmentally relevant concentrations of TCEP could result in growth retardation and induce significant hepatotoxicity in zebrafish.

A multibiomarker approach to assess the ecotoxicological effects of diclofenac on Asian clam Corbicula fluminea (O. F. Müller, 1774).

Diclofenac (DCF), one of the most current and widely used nonsteroidal anti-inflammatory drugs (NSAIDs), has been frequently detected in aquatic environments worldwide. However, the ecotoxicological effects of DCF on freshwater invertebrates remain largely unknown. In the present study, Corbicula fluminea were exposed to environmentally relevant concentrations of DCF (0, 2, 20, and 200 µg/L) for 28 days, and the potential adverse effects of DCF on siphoning behavior, antioxidant responses, and apoptosis were investigated. Our results showed that the siphon efficiencies of clams were significantly suppressed under DCF stress. DCF exerted neurotoxicity via reducing the activity of acetylcholinesterase (AChE) in gills and digestive gland of C. fluminea. Exposure to DCF induced antioxidant stress and increased malondialdehyde (MDA) levels in both gills and digestive gland of C. fluminea. Transcriptional alterations of apoptosis-related genes indicated that DCF might induce apoptosis by triggering mitochondrial apoptotic pathway. These findings can improve our understanding of the ecological risk of DCF in freshwater ecosystems.

New dual method for elastica regularization.

The Euler's elastica energy regularizer has been widely used in image processing and computer vision tasks. However, finding a fast and simple solver for the term remains challenging. In this paper, we propose a new dual method to simplify the solution. Classical fast solutions transform the complex optimization problem into simpler subproblems, but introduce many parameters and split operators in the process. Hence, we propose a new dual algorithm to maintain the constraint exactly, while using only one dual parameter to transform the problem into its alternate optimization form. The proposed dual method can be easily applied to level-set-based segmentation models that contain the Euler's elastic term. Lastly, we demonstrate the performance of the proposed method on both synthetic and real images in tasks image processing tasks, i.e. denoising, inpainting, and segmentation, as well as compare to the Augmented Lagrangian method (ALM) on the aforementioned tasks.

Microplastics: A tissue-specific threat to microbial community and biomarkers of discus fish (Symphysodon aequifasciatus).

As detriments in aquatic environments, microplastics (MPs) have been commonly studied on organisms, but tissue-scale effects of MPs were poorly understood. Discus fish (Symphysodon aequifasciatus), herewith, were exposed to polystyrene MPs (0/20/200 µg/L) for 28 d. We found that MPs significantly inhibited growth performance. MPs were observed in skin, gill and intestine after 14/28-d exposure. MPs bioaccumulation was independent of exposure time, but increased with MPs concentrations. Microbial community diversity of fish gill, but not skin and intestine, in MPs treatments was significantly increased. Bacterial community of MP-treated skin and gill were obviously separated from control. Skin dominant phyla changed from Actinobacteriota to Proteobacteria and Firmicutes. Proteobacteria gradually occupied dominance in gill after exposure. Furthermore, MPs-induced skin oxidative stress was demonstrated by the activation of superoxide dismutase and catalase. Skin malondialdehyde also increased and showed significant correlations with four bacterial phyla, e.g., Proteobacteria. Gill Na+/K+-ATPase activity decreased, strongly correlating to microbial community changes caused by MPs. Intestinal digestive enzymes activity (pepsin, lipase and α-amylase) reduced, revealing correlation with bacterial community especially Fibrobacterota. These results suggest a tissue-specific effect of MPs to microbial community and biomarkers in aquatic organism.

Large-scale analysis of 2,152 Ig-seq datasets reveals key features of B cell biology and the antibody repertoire.

Antibody repertoire sequencing enables researchers to acquire millions of B cell receptors and investigate these molecules at the single-nucleotide level. This power and resolution in studying humoral responses have led to its wide applications. However, most of these studies were conducted with a limited number of samples. Given the extraordinary diversity, assessment of these key features with a large sample set is demanded. Thus, we collect and systematically analyze 2,152 high-quality heavy-chain antibody repertoires. Our study reveals that 52 core variable genes universally contribute to more than 99% of each individual's repertoire; a distal interspersed preferences characterize V gene recombination; the number of public clones between two repertoires follows a linear model, and the positive selection dominates at RGYW motif in somatic hypermutations. Thus, this population-level analysis resolves some critical features of the antibody repertoire and may have significant value to the large cadre of scientists.

Spatial-Temporal Characteristic Analysis of Ethnic Toponyms Based on Spatial Information Entropy at the Rural Level in Northeast China.

As a symbol language, toponyms have inherited the unique local historical culture in the long process of historical development. As the birthplace of Manchu, there are many toponyms originated from multi-ethnic groups (e.g., Manchu, Mongol, Korean, Hui, and Xibe) in Northeast China which possess unique cultural connotations. This study aimed to (1) establish a spatial-temporal database of toponyms in Northeast China using a multi-source data set, and identify their ethnic types and origin times; and (2) explore the geographical distribution characteristics of ethnic toponyms and the evolution of rural settlements by comparing the spatial analysis and spatial information entropy methods. The results found that toponyms reflect not only the spatial distribution characteristics of the density and direction of ethnic groups, but also the migration law of rural settlements. Results also confirm that toponyms contain unique cultural connotations and provide a theoretical basis for the protection and promotion of the cultural connotations of toponyms. This research provides an entropic perspective and method for exploring the spatial-temporal evolutionary characteristics of ethnic groups and toponym mapping.

Targeting of growth factors in the treatment of hepatocellular carcinoma: The potentials of polysaccharides.

Hepatocellular carcinoma (HCC) has become a leading cause of cancer-associated mortality worldwide and is thus of great concern. Although various chemotherapeutic drugs are currently used for the treatment of HCC, severe side effects associated with these treatments have prompted interest in novel therapies, including the use of certain biological macromolecules such as polysaccharides. Several studies have shown that polysaccharides have anticancer and antiproliferative effects on HCC. Vascular endothelial growth factor, transforming growth factor ß, epidermal growth factor and fibroblast growth factor may be effective targets for polysaccharides and may modulate tumor growth and immunity through increasing the expression levels of cytokines. The present review focuses on the ways in which growth factors contribute to the development of HCC, and on the anti-growth factor activities of natural and synthetic polysaccharides, as well as their effect on proinflammatory cytokines.