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Heavy metal Cadmium (Cd2+) pollution has become a severe environmental problem for aquatic organisms. In crustaceans, gills (Gi) and hepatopancreas (Hp) play a vital role in the toxicology. However, in Macrobrachium rosenbergill, there are few researches about gill and hepatopancreases responding to Cd2+ stress at a molecular level. In this study, transcriptomic analysis was applied to characterize gene expression profiles of gills and hepatopancreas of M. rosenbergill after Cd2+ exposure for 0 h, 3 h and 3 d. Six cDNA libraries (Gi 0 h, Gi 3 h, Gi 3 d, Hp 0 h, Hp 3 h, and Hp 3 d) were constructed and a total of 66,676 transcripts and 48,991 unigenes were annotated. Furthermore, differentially expressed genes (DEGs) were isolated by comparing the Cd2+ treated time-point libraries (3 h and 3 d group) with the control library (0 h group). The results showed that most of the DEGs were down-regulated after Cd2+ exposure and the number of DEGs among gill groups were significantly higher than those among hepatopancreas groups. GO functional and KEGG pathway analysis suggested many key DEGs in response to the Cd2+ stress, such as metallothionein and Hemocyanin. Additionally, a total of six DEGs were randomly selected to further identify their expressional profile by qPCR. The results indicated that these DEGs were involved in the response to Cd2+. This comparative transcriptome provides valuable molecular information on the mechanisms of responding to Cd2+ stress in M. rosenbergii, which lays the foundation for further understanding of heavy metal stress. [ABSTRACT FROM AUTHOR]

In this study, the different dosage of laminarin groups (normal fodder group (Control), normal fodder add 1 g laminarin group (AL1), normal fodder add 2 g laminarin group (AL2), normal fodder add 4 g laminarin group (AL4) and normal fodder add 8 g laminarin group (AL8)) were set. After 45 days, the growth, enzyme activity and immune‐related gene were measured to assess the effect of feeding laminarin on Ictalurus punctatus. Laminarin (4 g dosage) can significantly increase body length (p <.05) and BMI (body mass index) value in 8 g dosage group (p <.05). Lysozyme, acid phosphatase, aspartate aminotransferase, catalase, superoxide dismutase, pepsin, amylase and trypsin activity are increased with the dosage of laminarin increasing, and have a significant difference at the dosage of 4 g and 8 g group (p <.001). However, the serum cortisol content, alkaline phosphatase and lipase activity have a significant inhibition in high‐dosage groups (p <.001). The expression of TLR5 gene in group of 4 g dosage was significantly upregulated (p <.05). The expression of SOCs gene in groups of 2 g (p <.05), 4 g (p <.001) and 8 g (p <.001) dosage was significantly downregulated. The expression of IGF2 and STAT5 genes was significantly upregulated in high‐dosage laminarin groups. Generally, larminarin enhances the immune response, reduces the rate of energy decomposition required and improves food absorption. This shows that the larminarin improves the physical quality and increases productivity of I. punctatus, and offers great potential for application in the aquaculture industry. [ABSTRACT FROM AUTHOR]

• Cd and DCF accumulate more in the hepatopancreas than in other tissues. • Cd and DCF caused pathological damage to hepatopancreas and intestine. • Strong oxidative stress in tissues induced by Cd and DCF combined exposure. • The Firmicutes/Bacteroidetes ratio of high concentration group rose significantly. • Cd and DCF exposure affect the carbon and nitrogen cycle of gut microflora. In recent years, excessive discharge of pollutants has led to increasing concentrations of cadmium (Cd) and diclofenac (DCF) in water; however, the toxicity mechanism of combined exposure of the two pollutants to aquatic animals has not been fully studied. Procambarus clarkii is an economically important aquatic species that is easily affected by Cd and DCF. This study examined the effects of combined exposure to Cd and DCF on the tissue accumulation, physiology, biochemistry, and gut microflora of P. clarkii. The results showed that Cd and DCF accumulated in tissues in the order of hepatopancreas > gill > intestine > muscle. The hepatopancreas and intestines were subjected to severe oxidative stress, with significantly increased antioxidant enzyme activity. Pathological examination revealed lumen expansion and epithelial vacuolisation in the hepatopancreas and damage to the villous capillaries and wall in the intestine. The co-exposure to Cadmium (Cd) and Diclofenac (DCF) disrupts the Firmicutes/Bacteroidetes (F/B) ratio, impairing the regular functioning of intestinal microbiota in carbon (C) and nitrogen (N) cycling. This disturbance consequently hinders the absorption and utilization of energy and nutrients in Procambarus clarkii. This study offers critical insights into the toxicological mechanisms underlying the combined effects of Cd and DCF, and suggests potential approaches to alleviate their adverse impacts on aquatic ecosystems. [Display omitted] [ABSTRACT FROM AUTHOR]

Channel catfish (Ictalurus punctatus) is an important aquaculture species in China. In channel catfish, diseases such as haemorrhagic, sepsis and tail-rot disease are all caused by bacteria as general in China. Most of the pathogenic bacteria are Gram-negative bacteria. Liver transcriptome analysis of the co-injection of cortisol and lipopolysaccharide (LPS) was performed in this study. Preliminary evidence from the results suggest that after the emergence of immune stress, cortisol will up-regulate the complement cascade pathway, down-regulate the coagulation cascade pathway, down-regulate the platelet activation pathway, down-regulate antigen presentation pathway, and show complex regulation relationship to inflammatory factors. At 12 h, the number of differential genes regulated by cortisol was about half less than the number of differential genes regulated by LPS. At 24 h, there was no significant difference between the number of differential genes regulated by cortisol and LPS, but the types of differential genes vary widely. KEGG enrichment analysis found that cortisol regulated LPS-stimulated immune responses mainly focus on cytokines, complement and coagulation cascades pathways, antigen presentation pathways, haematopoiesis, and inflammation. It is suggested that there may be some strategic choice in the regulation of immune response by cortisol. These results will help understand the pathogenesis and host defence system in bacterial disease caused by Gram-negative bacteria. • Liver of channel catfish (Ictalurus punctatus) transcriptome test was used to study the regulation of LPS-induced immune response by cortisol. • Cortisol regulates immune responses of LPS-stimulated mainly focus on cytokines, complement and coagulation cascades pathway, antigen presentation pathways, haematopoiesis, and inflammation. • Cortisol upregulates the complement alternative pathway at 12 h and negatively regulates it at 24 h. • After the immune stress, the regulation of cortisol on immune response maybe choose different regulation strategies over time. [ABSTRACT FROM AUTHOR]

Electrolyzing water is an environmentally friendly and renewable way to obtain high purity hydrogen. Ruthenium has strong water dissociation ability and suitable hydrogen adsorption energy, so it is considered as one of the candidates of excellent electrocatalysts for hydrogen evolution in alkaline solution. The dynamic hydrogen bubble template (DHBT) is a good electrodeposition technology, which can obtain the 3D metal foams. However, as far as we know, there is no report on the preparation of Ru electrocatalyst by the DBHT method. In this work, the trumpet-shaped Ru on amorphous cobalt support (T-Ru/a-Co) is prepared by the DHBT electrodeposition for the first time. The defect locations are uniformly distributed on the surface of amorphous cobalt (a-Co), which can effectively lead to the formation of nano-bubble template in the DHBT process. However, this special morphology cannot be obtained on the surface of crystalline Co (c-Co). In addition, the electronic structure of T-Ru/a-Co has also been obviously modified, in which the proportion of Ru4+/Ru0 in T-Ru/a-Co has increased, accompanied by the change of binding energy of Ru. It only needs an overpotential of 49 mV to obtain a current density of 10 mA cm−2 for the T-Ru/a-Co. The specific activity (SA), turnover frequency (TOF) and mass activity (MA) of T-Ru/a-Co are 0.23 mA cm−2, 0.48 s−1 and 0.24 A mg−1, which are both higher than those of Pt/C, the disk-shaped Ru on the c-Co support (D-Ru/c-Co) and Ru/C, respectively. • The trumpet-shaped Ru is prepared by the dynamic hydrogen bubble template (DHBT) electrodeposition for the first time. • The amorphous Co can form nano-bubble template in DHBT process, but it can't be realized on the surface of crystalline Co. • The electronic structure of trumpet-shaped Ru has also been obviously modified. • The specific activity, turnover frequency and mass activity of trumpet-shaped Ru are both higher than those of Pt/C. [ABSTRACT FROM AUTHOR]

Background: The red swamp crawfish, Procambarus clarkii, has become one of the most economically important cultured species in China. Currently, little is known about the gonadal development of this species. Isolation and characterization of genes are an initial step towards understanding gonadal development of P. clarkii. Results: Using the 454 pyrosequencing technology, we obtained a total of 1,134,993 high quality sequence reads from the crawfish testis and ovary libraries. We aimed to identify different genes with a potential role in gonad development. The assembly formed into 22,652 isotigs, distributed by GO analysis across 55 categories in the three ontologies, ‘molecular function’, ‘cellular component’, and ‘biological processes’. Comparative transcript analysis showed that 1,720 isotigs in the ovary were up-regulated and 2138 isotigs were down-regulated. Several gonad development related genes, such as vitellogenin, cyclin B, cyclin-dependent kinases 2, Dmc1 and ubiquitin were identified. Quantitative real-time PCR verified the expression profiles of 14 differentially expressed genes, and confirmed the reliability of the 454 pyrosequencing. Conclusions: Our findings provide an archive for future research on gonadal development at a molecular level in P. clarkii and other crustacean. This data will be helpful to develop new ideas for artificial regulation of the reproductive process in crawfish aquaculture. [ABSTRACT FROM AUTHOR]

Nitrite is one of the most common pollutants in high-density aquaculture or in recirculated aquaculture systems. In this study, gene and miRNA expression dynamics were investigated for unveiling the genetic regulation of Eriocheir sinensis in response to acute nitrite stress. Two groups of E. sinensis with different vitality of appendages (i.e., NG and DG) were treated with nitrite-N in 6 and 24 h, respectively. A number of differentially expressed (DE) genes and miRNAs were detected in the pairwise comparisons of the two groups. We found that the DE genes and the target genes of DE miRNAs were significantly enriched into some key pathways, such as metabolic pathways, MAPK signaling pathway, and nitrogen metabolism. Notably, the number of DE genes identified from the pairwise comparison of MNG vs. FNG (NG groups at 6 h and 12 h, respectively) was much larger than that identified from MDG vs. FDG (FG groups at 6 h and 12 h, respectively), indicating that the individuals from strong vitality group had genetic superiority for tolerance of nitrite stress. The similar trend was also observed from the identification of DE miRNAs. Some key genes (e.g., hsp70, mtnd2, act7, hspg2, cam-1) involved in signaling transduction, oxidative phosphorylation, and energy metabolism were detected in this study. Besides, several miRNAs (miR-31, miR-215, miR-142-x) that mediate the calmodulin related genes were also identified, inferring that calcium signaling pathway participates in the responses to nitrite stress in crabs. This study revealed the mRNA and miRNA expression patterns of Chinese mitten crab under sustained nitrite stress and provided the genetic basis for the molecular selective breeding. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine the probable pathogen causing the recently discovered hepatopancreas browned disease (HPBD) in Chinese mitten crab (Eriocheir sinensis), an important freshwater aquaculture species. Hepatopancreas material was collected from 30 E. sinensis individuals confirmed as infected using plasma coagulase tests. Genes nuc and femA, both specific for Staphylococcus aureus, were amplified by reverse transcription-PCR from three randomly selected HPBD-infected crabs, specific bands were observed at 191 and 397 bp, and amplified partial sequences aligned perfectly (100%) with published nuc and femA gene sequences using BLAST and GenBank. Four major developmental stages of hepatopancreas histopathological changes were observed in 7-week reverse infection challenge tests in 90 pathogen-induced animals; hepatopancreas material changed colour from orange to yellow, red to brown, and light brown to almost fully necrotised. Optical and transmission electron microscopy revealed similar hepatopancreas pathological characteristics to those of HPBD-infected E. sinensis. The hepatopancreas browning rate of infected crabs (88.89 ± 5.09%) was significantly higher than controls (7.78 ± 1.92%). These results suggest S. aureus is the probable pathogen causing HPBD in E. sinensis, and infection leads to inflammation, atrophy, and complication of hepatopancreatic necrosis. [ABSTRACT FROM AUTHOR]

Nano-network Ru with definite lattice defects on amorphous Co nanosheets is obtained for the first time. Amorphous Co support can promote the surface Ru to obtain special morphology and modified electronic structure, thus improving HER activity in alkaline solution. A current density of 10 mA cm−2 can be obtained only with an overpotential of 33.5 mV. [ABSTRACT FROM AUTHOR]

A Stackelberg game-based approximate optimal interaction control approach is presented for human-centered modular robot manipulator (MRM) systems. Joint torque feedback (JTF) technique is utilized to form the MRM dynamic model. The major objective of optimal control with human–robot collaboration (HRC) is transformed into approximating Stackelberg equilibrium by adopting Stackelberg game governed between the human and the MRM that are regarded as players with different hierarchical level in interaction process. On the basis of the adaptive dynamic programming (ADP), the approximate optimal interaction control policy with HRC task is developed via critic neural network (NN)-based Stackelberg game manner for addressing Hamilton–Jacobian (HJ) equations. The position tracking error is ultimately uniformly bounded (UUB) according to the Lyapunov theory. Experiment results demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Methyl farnesoate (MF), a de-epoxidized form of juvenile hormone (JH) Ⅲ in insects, may regulate developmental processes such as reproduction and ovarian maturation in crustaceans. Krüppel homolog 1 (Kr-h1) is a target response gene for the methoprene-tolerant (Met) protein that is a component of the JH signaling pathway in insects. In the present study, Es-Kr-h1 was cloned from E. sinensis and characterized to ascertain whether JH/MF signaling in insects is conserved in crustaceans. The findings with molecular structure analysis indicated Es-Kr-h1 contains seven zinc finger motifs (Zn2–Zn8) commonly conserved in other crustaceans, but the Zn1 motif was not detected to be present. The PCR results indicated that relative abundance of Es-Kr-h1 mRNA transcript in the hepatopancreas was greatest in the Stage Ⅱ, followed by the Stage Ⅳ ovarian developmental categories. The relative abundance of Es-Kr-h1 mRNA transcript in vitro was greater after MF addition to the hepatopancreas, however, not the ovarian tissues. The results from in vivo and eyestalk ablation experiments indicated the relative abundance of Es-Kr-h1 mRNA transcript was greater after MF treatment and bilateral eyestalk removal in the hepatopancreas, however, not ovarian tissues. Notably, there were effects of MF on relative abundance of Es-Kr-h1 mRNA transcript pattern. The Es-Kr-h1 protein, therefore, may be involved in MF-mediated vitellogenesis resulting from the response to Es-Met in E. sinensis , and the JH/MF signaling pathway is potentially conserved in crustaceans. [ABSTRACT FROM AUTHOR]

Sediment bacteria are crucial for maintaining water quality, preventing disease, and cycling nutrients in aquaculture ponds. In the present study, a total of 42 sediment samples were collected over the course of four months from three farms. By using 16S rRNA high-throughput sequencing techniques, bacterial communities were studied. Proteobacteria, Chloroflexi, Desulfobacterota, Firmicutes, Actinobacteriota, Bacteroidetes and Acidobacteriota were the dominant species at the phylum level in all samples. Spatial variation had a greater impact on the bacterial community composition and distribution of brackish pond sediments. Chloroflexi, Desulfobacterota, Spirochaetota and Latescibacterota were all substantially correlated positively with salinity. Moreover, salinity was negatively correlated with beta diversity. Salinity and total organic carbon were positively correlated with bacterial community distribution. This study was helpful to understand the response of bacterial communities to habitat changes, and provided a theoretical reference for the environmental supervision of aquaculture in sediment of brackish channel catfish ponds in Eastern China. • Sediment bacterial communities in brackish channel catfish ponds along the eastern coast of China were studied. • Spatial changes had a greater impact on the composition of bacterial communities. • SAL and TC had a significant effect on the diversity and composition of bacterial communities. [ABSTRACT FROM AUTHOR]

The research and development of high-efficiency low-temperature disinfection technology in all aspects of cold-chain food has begun to receive attention. This paper aims to develop low temperature acidic electrolyzed water (LT-AEW) disinfectant. The anti-freezing temperature, disinfection efficiency and practical application effect were evaluated in detail. The results had shown that the freezing point of AEW can be reduced to −18 °C by adding 25% CaCl 2 , 20% NaCl, 30% ethylene glycol (EG) and 35% propylene glycol (PG). At the low temperature (−1, −10 and −18 °C), the bactericidal efficiencies of all EG-acidic electrolyzed waters (EG-AEWs) with different EG contents were close. The reason is that although the low temperature environment will reduce the sterilization efficiency of EG-AEW, the addition of EG can promote the increase of HClO content in EG-AEW, thus increasing the sterilization efficiency. As long as the HClO content reached 35.2, 50.8 and 64.3 mg L−1, the killing logarithm (KL) value had achieved 4.50, 4.49 and 5.07 log 10 (CFU mL−1). Finally, the KL values of EG-AEW against Escherichia coli on the corrugated board and stainless-steel board both exceeded 3 log 10 (CFU mL−1) at the low temperature, which indicates that EG-AEW can be applied in food cold chain. • A low temperature acidic electrolyzed water (LT-AEW) is studied for the first time. • The freezing point of ethylene glycol AEW (EG-AEW) can reach to −18 °C. • The killing logarithm of EG-AEW against E. coli is 5.07 log 10 (CFU mL−1) at −18 °C. • EG-AEW can effectively sterilize E. coli on corrugated and stainless-steel board. [ABSTRACT FROM AUTHOR]

Methoprene-tolerant (Met) belongs to the basic helix-loop-helix (bHLH)-Per-Arnt-Sim (PAS) family of nuclear transcriptional regulators and is a leading candidate receptor for juvenile hormone (JH III) in insects. Methyl farnesoate (MF) is a de-epoxide form of JH III that regulates many developmental processes in crustaceans, including reproduction, molting, and morphogenesis, much like JH III in insects. In this study, the full-length cDNA for Met was cloned from the Chinese mitten crab (Eriocheir sinensis) (EsMet). The amino acid sequence of EsMet contains three conserved domains (bHLH, PAS-A, and PAS B) characteristic of the bHLH-PAS family, having six conserved amino acid residues specifically responsible for JH or MF binding. Tissue distribution analysis revealed that EsMet mRNA is highly expressed in the hepatopancreas. In addition, EsMet and EsVg expression in the hepatopancreas were found to be significantly increased in early endogenous vitellogenic oocytes (stage II) during ovarian development, and the hemolymph MF titer was significantly increased in late exogenous vitellogenic oocytes (stage III), indicating that EsMet is involved in vitellogenesis regulation. In vitro , MF addition markedly upregulated EsMet and EsVg expression in hepatopancreatic tissue, but only EsVg was induced in ovarian tissue. In vivo , EsMet and EsVg expression in the hepatopancreas were both significantly and synchronously increased after MF injection, but not in the ovaries. In addition, EsMet and EsVg expression were upregulated in the hepatopancreas after eyestalk ablation, while only EsVg expression was induced in the ovaries. Thus, our results indicate that Met may act as a receptor for MF in MF-mediated vitellogenesis in crustaceans. Unlabelled Image • A novel Met gene was isolated and characterized from Eriocheir sinensis. • Effect of MF on EsMet and EsVg expression in vitro and vivo were analyzed. • A positive correlation of EsMet and EsVg expression levels with hemolymph MF titer. • EsMet possibly act as a MF receptor in MF-mediated vitellogenesis. [ABSTRACT FROM AUTHOR]