Search

This study examines the physiological and immunological effects of 0.5 ppm carbaryl exposure on juvenile Asian seabass (Lates calcarifer) over 12 h to 72 h. Notable results include decreased activities of liver enzymes catalase (CAT), lactate dehydrogenase (LDH), and glutathione peroxidase (GSH-PX), while superoxide dismutase (SOD) levels remained stable, with the lowest activities of CAT and GSH-PX observed at 72 h. Serum biochemistry revealed increased alkaline phosphatase (AKP) and acid phosphatase (ACP) at 24 h, with declining aspartate aminotransferase (AST) and a peak in creatinine at 48 h. Histopathological analysis showed carbaryl-induced necrosis in liver and spleen cells, and increased melanomacrophage centers in both organs. Additionally, immune gene expression analysis indicated an upregulation of heat shock proteins and consistent elevation of complement component C3 and interleukin-8 (IL-8). These findings suggest that carbaryl exposure significantly impairs organ function and modulates immune responses in L. calcarifer, underlining the need for further research on protective strategies against pesticide impacts in aquaculture.

The grain preferential orientation has a significant influence on the mechanical properties of silicon nitride (Si3N4) ceramics. Based on the Jeffery’s theory, a grain rotation model under uniaxial compression is created to predict the texture evolution mechanism during sintering of Si3N4 ceramics. With deformation, the grain orientation was predicted to rotate towards the plane perpendicular to the pressure direction, and large strain was favorable for the formation of strong texture. According to guidance of the model, the weakly textured microstructure prepared by normal hot pressing is attributed to the limited strain, due to the constrains of graphite die. Therefore, a new PHIP (pseudo-hot isostatic pressing) process with the large deformation is guided to fabricate the strongly textured ceramics by promoting the grain rotation and dynamic grain growth. Generally, the experimental results are well accordance with the model prediction. Furthermore, this model could be applied to guide the design and fabrication of other isotropic and anisotropic ceramic materials.

Aluminium extrusion profiles are widely utilised due to their potential to enhance energy efficiency and reduce costs. In this paper, two advanced tool designs for a novel sideways extrusion technique, the Unified design and the Guided design, were proposed. These designs facilitate the production of three-dimensional curved profiles with marked asymmetry and large-scale cross-sections. Numerical simulations of the initial designs revealed considerable variations in bending shapes compared to the target profile. Employing the Taguchi method combined with grey relational analysis, the study identified that the extrudate's bending shape are influenced by the die orifice position and the speed ratio of two rams with different sensitivities. Following this, optimal designs were derived for both design types. For the particular profile in this study, the simulation results showed that the optimal Unified design permitted better welding quality and lower extrusion force. However, the optimal Guided design achieved a bending shape more aligned with the target shape. It can also provide enhanced stability in the extrusion system and higher production yield compared to the optimal Unified design.

Spotted babylon were exposed to three different pH levels (7.0, 8.0 and 9.0) and four different concentrations of ammonia nitrogen (0.02, 1.02, 5.10 and 10.20 mg/L) in seawater to determine their acute toxicity and physiological responses to environmental fluctuation. The study evaluated four antioxidant enzymes: catalase (CAT), alkaline, superoxide dismutase (SOD), peroxidase (POD) and glutathione peroxidase (GSH-PX), and two immunoenzymes: acid phosphatase (ACP) and phosphatase (AKP). Over time, the immunoenzyme activity was significantly affected by pH and ammonia nitrogen concentration. After being exposed to pH and ammonia nitrogen, the spotted babylon showed signs of unresponsiveness to external stimuli, reduced vitality, slow movement, and an inability to maintain an upright position. Over time, the spotted babylon exhibited a trend of increasing and then decreasing GSH-PX, CAT, and SOD activities to adapt to the changing environment and enhance its immunity. On the contrary, the POD and ACP activities exhibited a decreasing trend initially, followed by an increasing trend over time and the AKP activity showed a gradual increase with time. The combined effect of pH and ammonia was found to be stronger than the effect of either factor alone. The interaction between pH and ammonia increased the activity of the spotted babylon antioxidant enzymes, induced oxidative stress, and reduced the ability of the spotted babylon's non-specific immune system to reverse it. Thus, the reverse-back of the spotted babylon was higher when pH and ammonia stress were dual than when pH or ammonia were single-factor stresses. The study results will establish a theoretical basis for analyzing the risk of multiple factors to the spotted babylon, and also enrich the basic information about the shellfish immune system.

In this work, nanocrystalline high-entropy ceramics (HECs) were prepared by the combination of combustion synthesis and ultra-high pressure sintering. The prepared high-entropy (La0.2Nd0.2Sm0.2Eu0.2Gd0.2)2Zr2O7 ceramic powder had the average grain size of 11 nm and displayed the disordered defective fluorite structure. The HECs sintered under ultra-high pressure showed the defective fluorite structure, whereas the control samples fabricated by pressureless sintering showed the ordered pyrochlore structure. The HECs sintered under pressure of 10 GPa possessed much smaller grain size than that obtained by pressureless sintering. In particular, the grain size of ceramics sintered under 10 GPa at 600 °C was not significantly larger than that of raw powder and its Vickers hardness was 11.9 GPa. Ultra-high pressure sintering could remarkably increase the density of ceramics and restrain the growth of grains. The plastic deformation under ultra-high pressure was believed as the main densification mechanism for the grain refinement and performance improvement.

Ammonium (NH4+) plays a crucial role in the reproductive processes of key biotic groups in aquatic ecosystems—bivalves. This study aims to elucidate the effects of three different ammonium ion concentrations on sperm vitality, swimming kinematics, and morphology of Mimachlamys nobilis, Pinctada fucata martensii, and Saccostrea mordax. The results indicate that the sperm vitality and motility rates of M.nobilis and S. mordax are inversely proportional to the ammonium concentration, especially in the treatment group with an ammonium concentration of 3 mmol/L, where the decrease in sperm vitality and motility is most significant. In contrast, the sperm of P. fucata martensii reacted differently to increasing ammonium concentrations. After the addition of 2 mmol/L of ammonium, the sperm vitality and motility of P. fucata martensii reached a peak, showing a significant stimulatory effect. Additionally, as the ammonium concentration increased, the curling of the sperm flagella in M.nobilis and S. mordax increased. However, sperm flagella curling in P. fucata martensii showed no change compared to the control group. This study provides insights into the effects of ammonium concentrations on the sperm vitality and motility of three marine bivalve species and highlights the importance of sperm flagella curling as a factor affecting sperm.

Inspired by the layered structure, light absorption, and charge carrier pathway of chloroplast thylakoids in natural photosynthesis, we propose a novel artificial photosynthesis platform, which is composed of layered structured vaterite as the scaffold with gold nanoparticles (AuNPs), photosensitizer eosin Y (EY), and redox enzyme L-glutamate dehydrogenase (GDH) as the functional components. The EY exhibited significantly enhanced light absorption and charge carrier generation due to the localized surface plasmon resonance (LSPR) around the AuNPs and light refraction within the layers. This artificial photosynthesis platform can regenerate reduced nicotinamide adenine dinucleotide (NADH) under visible light and promote the rapid conversion of α-ketoglutarate to L-glutamate (0.453 Mm/h). The excellent biocompatibility of layered vaterite significantly enhances the resistance of GDH to harsh conditions, including high pH (pH = 10) and elevated temperatures (37–57 °C).

The Asian seabass (Lates calcarifer) has high economic value and is the primary aquaculture species in China. Licorice (Glycyrrhiza uralensis) as a feed additive has demonstrated significant immunological benefits in aquaculture. However, its effects on the growth of aquatic animals are largely unexplored. This study explored the influence of licorice on the level of growth-related genes in Asian seabass by conducting an experiment using artificial feed with 0%, 1%, 3%, and 5% licorice. The impact on growth performance and the expression of several genes, including growth hormone–releasing hormone (GHRH), growth hormone (GH), growth hormone receptor (GHR), insulin-like growth factor 1 (IGF1), IGF2, IGF2 receptor (IGF2R), myostatin 1 (MSTN1), and myostatin 2 (MSTN2), were studied over 56 d. According to the results, the 3% and 5% licorice-supplemented diets significantly improved survival rates and weight gain compared to the control group. Licorice affected the level of growth-associated genes in Asian seabass and significantly increased the levels of GHR and IGF1 in the liver. However, a 5% licorice diet downregulated the expression of IGF2. As the licorice content in the diet increased, the levels of IGF2R and MSTN1 in the muscle tissue first decreased and then increased, and licorice addition inhibited the MSTN2 expression. The inclusion of licorice in the feed led to a significant downregulation of the GH and GHRH expression (p < 0.05). In summary, adding a certain proportion of licorice to the diet can improve the survival rate of the Asian seabass. Moreover, a proper proportion of licorice can increase the expression of related growth genes of fish, effectively increasing their weight gain rate and specific growth rate.

This study aimed to explore the impact of acute acidification on the antioxidant, metabolic performance, and liver histology of juvenile yellowfin tuna. The experiment subjected juvenile yellowfin tuna to a pH gradient environment of 8.1, 7.6, 7.1, and 6.6 for 48 h. The findings indicate that a seawater pH of 7.1 significantly impacts the antioxidant and metabolic systems of the juvenile yellowfin tuna in comparison to the control group. At pH 7.1, there were observed increases in glutathione reductase (GR), total antioxidant capacity (T-AOC), lactate dehydrogenase (LDH), hexokinase (HK), pyruvate kinase (PK), sodium-potassium ATPase (Na+K+-ATP), and calcium-magnesium ATPase (Ca2+Mg2+-ATP). Conversely, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TGs) were not significantly different across the treatment groups. However, an increase in transaminases at pH 7.1 suggested potential liver damage, which was further supported by observed structural liver tissue degeneration and hepatocyte vacuolation. In conclusion, under conditions of acute acidification stress, there is a decrease in antioxidant capacity and a suppression of metabolic levels in juvenile yellowfin tuna, leading to oxidative damage. This study lays the foundation for an in-depth understanding of the response mechanisms of juvenile yellowfin tuna in response to seawater acidification as well as healthy tuna farming in the broader context of seawater acidification.

This study investigated the effects of acute ammonia nitrogen (NH3-N) exposure on kidney antioxidant ability and phosphatases and related gene expression in juvenile yellowfin tuna (Thunnus albacares). The 180 juvenile yellowfin tuna (260.39 ± 55.99 g, 22.33 ± 2.28 cm) were exposed to ammonia for 6, 24, and 36 h using natural seawater (0 mg/L) as a control and NH3-N at 5 and 10 mg/L. The lipid peroxidation byproduct malondialdehyde (MDA) and the levels of antioxidant enzymes, such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-PX), alkaline phosphatase (AKP), and acid phosphatase (ACP), were measured using the colorimetric method in the trunk kidney to determine changes in antioxidant ability and phosphatase activity of juvenile yellowfin tuna exposed to NH3-N. Results indicated that, at 36 h, MDA, SOD, CAT, and GSH-PX levels rose in the 5 mg/L group versus the control. In the 10 mg/L group, MDA and SOD, CAT, and GSH-PX activities significantly increased after 24 and 36 h exposure compared to the control. Phosphatases play a pivotal role in the immune system. AKP activity significantly increased at 6 h, and ACP activity markedly rose at 36 h in the 5 mg/L group versus the control. Real-time fluorescence quantitative PCR was applied to detect alterations in the antioxidant genes SOD2, CAT, and glutathione peroxidase 1b (GPX1b) and immune cytokines-related genes Interleukin 10 (IL-10) and Interleukin 6 receptor (IL-6r) expression in the head kidney in juvenile tuna. Relative to the control, antioxidant gene expression in the 5 mg/L group significantly rose at 6 and 36 h, and in the 10 mg/L group, SOD2 and GPX1b were significantly elevated at 36 h. Compared to the control group, IL-10 expression in the 5 mg/L group significantly increased at 6 h, whereas IL-6r expression decreased. In the 10 mg/L group, both IL-10 and IL-6r levels were observed to be lower. Low ammonia nitrogen concentrations boost antioxidant defenses, phosphatase activities, and gene expression levels, whereas higher levels may induce suppressive effects. In yellowfin tuna juvenile farming, NH3-N concentration significantly affects the health of the juveniles. When the NH3-N concentration is between 5–10 mg/L, the stress duration should be limited to 24 h; if the concentration is below 5 mg/L, the stress duration can be extended to 36 h.

Abstract The improvement of non-oxide ceramic plasticity while maintaining the high-temperature strength is a great challenge through the classical strategy, which generally includes decreasing grain size to several nanometers or adding ductile binder phase. Here, we report that the plasticity of fully dense boron carbide (B4C) is greatly enhanced due to the boundary non-stoichiometry induced by high-pressure sintering technology. The effect decreases the plastic deformation temperature of B4C by 200 °C compared to that of conventionally-sintered specimens. Promoted grain boundary diffusion is found to enhance grain boundary sliding, which dominate the lower-temperature plasticity. In addition, the as-produced specimen maintains extraordinary strength before the occurrence of plasticity. The study provides an efficient strategy by boundary chemical change to facilitate the plasticity of ceramic materials.

The mineralization of octacalcium phosphate (OCP) crystals in gel media was studied in the presence of a magnetic field. OCP crystal growth was found to be dependent on mineralization temperature, mineralization time, and the magnetic field. Higher temperatures significantly reduced the mineralization time, which is crucial for directional growth of OCP crystals. The growth of OCP crystals was accelerated by the applied magnetic field, while OCP crystals generated in the presence of a magnetic field exhibited increased length and width of oriented growth. This study provides valuable insights into the influence of mineralization factors in bioprocessing-inspired manufacturing processes.

In order to understand the effects of fermented Astragalus membranaceus (FAM) on the liver and intestinal health of tiger grouper (Epinephelus fuscoguttatus), this study was conducted. This study evaluates the effects of different levels of FAM on liver and intestinal tissue structure, serum biochemical parameters, intestinal digestive enzyme, and microbiota structure of tiger grouper. Fish were fed with diets (crude protein ≥ 48.0%, crude fat ≥ 10.0%) with five levels of FAM (L1:0.25%, L2: 0.5%, L3: 1%, L4: 2% and L5: 4%) in the experimental groups and a regular diet was used as the control (L0: 0%) for 8 weeks. Compared with AM, the protein content of FAM was significantly changed by 34.70%, indicating that a large amount of bacterial protein was produced after AM fermentation, and its nutritional value was improved. FAM had significant effects on the growth performance of tiger grouper (p < 0.05). The high-density lipoprotein cholesterol (HDL-C) was highest in L4 group, being significantly different from L0 group. The area and diameter of hepatocytes were lowest in L3 and L4, and the density of hepatocyte was highest in L4 group and relatively decreased in L5 group. The mucosal height and muscular thickness were highest in L3 group. The intestinal microbiota structure of tiger grouper was changed under the intervention of FAM. The lower abundance of potential pathogenic bacteria and higher abundance of probiotics colonization in the L4 group showed that the dose of FAM had the best effect on improving the health of intestinal microbiota. This study indicates that the addition of FAM in the feed contributes to liver health, improves intestinal morphology, and regulates the intestinal microbiota of tiger grouper. The addition ratio of 1%–2% is better for intestinal and liver health, and a high addition ratio will cause liver damage. Our work will provide a reference for the addition and management of FAM in the aquaculture industry.

Abstract The combined effects of temperature and salinity on the digestion and respiration metabolism of Pinctada fucata were evaluated via response surface methodology and box-benhnken design under laboratory condition. Results indicated that the primary and secondary effects of salinity and temperature had significant effects on amylase (AMS) of P. fucata (P 0.05), but had a significant effect on TRYP as a secondary effect (P 0.05). The primary, secondary and interaction effects of salinity had significant effects on NKA (Na+-K+-ATPase) of P. fucata (P

High-purity and high-yield boron nitride nanotubes with large aspect ratio were prepared by a facile two-step process, including the synthesis of boron/nickel containing precursors by precipitation reactions and subsequent thermally catalytic chemical vapor deposition reactions. The influence of catalyst content and annealing temperature on the phase composition and microstructure of the products were investigated. The results show that it is difficult to exert the catalytic effect of nickel-based catalyst at low temperatures (

Abstract Bioinspired hydrogels are complex materials with distinctive properties comparable to biological tissues. Their exceptional sensitivity to various external stimuli leads to substantial application potential in wearable smart devices. However, these multifaceted hydrogels are often challenging to be combined with pattern customization, stimulus responsiveness, self‐healing, and biocompatibility. Herein, inspired by mussel secretions, a printable, self‐healing, and biocompatible MXene‐based composite hydrogel was designed and prepared by incorporating Ti3C2Tx MXene nanosheets into the hydrogel framework through the chelation of calcium ions (Ca2+) with polyacrylic acid and cellulose nanofibers at alkaline conditions. The biocompatible conductive hydrogel exhibited sensitivity (gauge factor of 2.16), self‐healing (within 1 s), recognition, and adhesion, distinguishing it as an ideal candidate for wearable multifunctional sensors toward strain sensing, vocal sensing, signature detection, and Morse code transmission. Additionally, the multifunctional hydrogel manifested efficient electromagnetic interference shielding properties (reaching more than 30 dB at a thickness of 2.0 mm), protecting electronics and humans from electromagnetic radiation and pollution. Therefore, the presented work represents a versatile strategy for developing environmentally friendly conductive hydrogels, demonstrating the perspectives of intelligent hydrogels for multifunctional applications.

This study aimed to elucidate the effects of different photoperiods (0 L:24 D, 6 L:18 D, 12 L:12 D, 18 L:6 D, 24 L:0 D, “Light (L) and Dark (D)”) on the growth performance and physiological responses of the juvenile scalloped spiny lobster (Panulirus homarus). Over a period of 56 days, parameters such as growth rate, digestive enzyme, immune enzyme, and antioxidant enzyme were meticulously evaluated in 90 lobsters subjected to these varying light conditions. The present study found no significant differences in survival rate (SR), molting frequency (MF), and meat yield production (MYP) among the various photoperiod treatments (p > 0.05). Notably, the highest weight gain rate (WGR) and specific growth rate (SGR) were observed under a 12 L:12 D photoperiod. In the continuous dark phase (0 L:24 D), pepsin (PEP) activity remained high in gastric tissues, while trypsin (TRYP) and chymotrypsin (CHT) activities reached the highest in hepatopancreas tissues. The α-amylase (AMS) activity in the hepatopancreas was most elevated under 18 L:6 D, and the optimal lipase (LPS) activity was recorded under 12 L:12 D. The activity of acid phosphatase (ACP) in the hepatopancreas was highest in the absence of light (0 L:24 D), whereas the activities of alkaline phosphatase (AKP) and lysozyme (LZM) were most effective under the 12 L:12 D photoperiod. The total antioxidant capacity (T-AOC), along with catalase (CAT) and superoxide dismutase (SOD) activities of the hepatopancreas reached the highest at 12 L:12 D. The highest activity of glutathione peroxidase (GSH-Px) was seen under 18 L:6 D. The concentration of malondialdehyde (MDA), a marker of oxidative stress, was found to be highest under 12 L:12 D. Consequently, this specific photoperiod is essential for achieving optimal growth and maintaining appropriate physiological balance in the scalloped spiny lobster during aquaculture. These findings provide a foundational guideline for establishing the lighting environment in the farming of the juvenile scalloped spiny lobster.

This study investigates the effect of a sudden change in salinity for 48 h on the digestive enzyme activity of juvenile yellowfin tuna. The treatment included a control salinity of 32‰ in natural seawater and an experimental salinity of 29‰. Acute stress experiments were carried out on 72 juvenile yellowfin tuna (646.52 ± 66.32 g) for 48 h to determine changes in digestive enzyme activity in different intestinal sections over time (0 h, 12 h, 24 h, 48 h). The activities of pepsin, trypsin, α-amylase, lipase, and chymotrypsin in the digestive organs (stomach, foregut, and pyloric ceca) of juvenile yellowfin tuna were measured. Pepsin and pancreatic protease in the experimental group were significantly lower than in the control group (p < 0.05). α-amylase showed a fluctuating trend of decreasing and then increasing, and its activity trend was pyloric ceca > foregut > stomach. The lipase activity of gastric tissues decreased at the beginning and then increased, reaching a minimum at 24 h (2.74 ± 1.99 U·g protein−1). The change of lipase in the pyloric ceca and foregut was increasing and then decreasing. The lipase activity trend was pyloric ceca > foregut > stomach. The chymotrypsin showed a decreasing and increasing trend and then stabilized at 48 h with a pattern of pyloric ceca > foregut > stomach. Similarly, the gut villi morphology was not significantly altered in the acutely salinity-stressed compared to the non-salinity-stressed. This study suggests that salinity may change the digestive function of juvenile yellowfin tuna, thereby affecting fish feeding, growth, and development. On the contrary, yellowfin tuna is highly adapted to 29‰ salinity. However, excessive stress may negatively affect digestive enzyme activity and reduce fish digestibility. This study may provide a scientific basis for a coastal aquaculture water environment for yellowfin tuna farming, which may guide the development and cultivation of aquaculture.

The aim of this study was to investigate the circadian rhythm of muscle-related gene expression in mackerel tuna under different weather conditions. The experiment was carried out under two weather conditions at four sampling times (6:00, 12:00, 18:00, and 24:00) to determine the expression of growth, function, and rhythm genes: white muscle rhythm genes were rhythmic on sunny and cloudy days, except for PER3 and RORA; all functional genes had daily rhythmicity. Red muscle had daily rhythmicity on both sunny and cloudy days; functional genes had daily rhythmicity except for MBNL. The expression levels of the rhythm gene PER1 were determined to be significantly different by independent t-test samples in white muscle at 6:00, 12:00, 18:00, and 24:00 under different weather conditions; the expression levels of the functional genes MBNL and MSTN were both significantly different. In the red muscle, the expression of the rhythm genes PER3, REVERBA, and BMAL1 was determined by independent t-test samples at 6:00, 12:00, 18:00, and 24:00 on cloudy and sunny days; the functional gene MBNL was significantly different. The present study showed that mackerel tuna muscle rhythm genes and functional genes varied significantly in expression levels depending on weather, time of day, and light intensity and that the expression levels of myogenic genes were closely related to clock gene expression. The fish were also able to adapt to changes in light intensity in different weather conditions through positive physiological regulation.

Heat is a powerful stressor for fish living in natural and artificial environments. Understanding the effects of heat stress on the physiological processes of fish is essential for better aquaculture and fisheries management. In this experiment, a heating rod was used to increase the temperature at 2°C/h to study the changes of energy allocation (CEA) and energy metabolity-related enzyme activities, including pepsin, trypsin, amylase, lipase, acid phosphatase, lactate dehydrogenase, alanine aminotransferase, glutamic oxalic aminotransferase and energy reserve (Ea), energy expenditure (ETS), in juvenile yellowfin tuna cells under acute temperature stress. The results showed that the Ea of juvenile yellowfin tuna muscles in response to high temperature (34°C) was significantly lower than that of the control (28°C), and it also increased ETS. At 6 h, CEA decreased slightly in the high-temperature group, but, the difference in CEA between 24 h and 0 h decreased. After heat stress for 6 h, the activities of acid phosphatase (ACP), lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and glutamic oxalacetic transaminase (AST) increased, indicating that the metabolic rate was accelerated. After heat stress for 24 h, the activity of ALT decreased, indicating that with time elapsed, the activities of some protein metabolizing enzymes increased, and some decreased. In this study, digestive enzymes, trypsin and lipase increased gradually. After heat stress, Ea and Ec change significantly. Yellowfin tuna muscles use lipids in response to sharp temperature increases at high temperatures, red muscles respond to temperature changes by increasing energy in the early stages, but not nearly as much, and white muscles reduce lipids.

Throughout billions of years, biological systems have evolved sophisticated, multiscale hierarchical structures to adapt to changing environments. Biomaterials are synthesized under mild conditions through a bottom-up self-assembly process, utilizing substances from the surrounding environment, and meanwhile are regulated by genes and proteins. Additive manufacturing, which mimics this natural process, provides a promising approach to developing new materials with advantageous properties similar to natural biological materials. This review presents an overview of natural biomaterials, emphasizing their chemical and structural compositions at various scales, from the nanoscale to the macroscale, and the key mechanisms underlying their properties. Additionally, this review describes the designs, preparations, and applications of bioinspired multifunctional materials produced through additive manufacturing at different scales, including nano, micro, micro-macro, and macro levels. The review highlights the potential of bioinspired additive manufacturing to develop new functional materials and insights into future directions and prospects in this field. By summarizing the characteristics of natural biomaterials and their synthetic counterparts, this review inspires the development of new materials that can be utilized in various applications.

High-performance and fine-grained TiB2–SiC composite ceramics were fabricated via hot pressing with ball-milled TiB2 powder doped with SiC. The final product was densified at a relatively low sintering temperature of 1850 °C and brief soaking time of 30 min. The effects of ball milling on TiB2 powder composition and densification behavior, mechanical properties, and microstructures of the ceramic composites were investigated. TiO2 and B2O3 in the raw material were converted to SiO2 via reactions with SiC and Si3N4, thereby forming liquid phases to promote densification. A longer milling time resulted in a small TiB2 grain size. The relative density, Vickers hardness, flexural strength, and fracture toughness of the fabricated TiB2–SiC composites reached 99.0% ± 0.3%, 24.25 ± 1.10 GPa, 647 ± 30 MPa, and 6.43 ± 0.15 MPa m1/2, respectively. The primary toughening mechanisms in the composites were crack deflection, partial crack branching, and crack bridging.

A 8-week feeding trial was conducted to determine the effects of dietary supplementation with curcumin on growth, intestinal health, and gills resistance to ammonia stress in juvenile Seriola dumerili. Three isonitrogenous and isolipidic test diets were prepared by supplementing incremental levels of dietary curcumin at 0% (CUR0%, control), 0.01% (CUR0.01%), 0.02% (CUR0.02%), respectively. Fish were fed with experimental diet. Recovery and protection capacity after ammonia challenge assay was adopted to test the effect of curcumin. At the end of the feeding trial, the results showed that dietary supplementation with proper curcumin level had a significant positive effect on fish survival and intestinal histology structure. Meanwhile, dietary supplementation with proper curcumin level can improve intestinal health by increasing immune enzyme activity, up-regulating the expression of anti-inflammatory cytokines, down-regulating the expression of pro-inflammatory cytokines and regulating other immune-related genes. Subsequently, after the ammonia challenge and recovery experiment, the results of antioxidant-related genes and antioxidant enzymes showed that dietary supplementation with proper curcumin level can improve the gill protective and recovery capacity from ammonia stress through increasing antioxidant capacity. These results suggest that dietary supplementation with proper curcumin can promote the growth, intestinal health, gill resistance and recovery to ammonia stress of S. dumerili.

We evaluated the effect of dietary curcumin supplementation on the antioxidant capacity of the liver and the resistance of the liver and spleen to ammonia stress in the great amberjack (Seriola dumerili). Three isonitrogenous and isolipidic test diets were prepared by supplementing incremental levels of dietary curcumin at 0 mg/kg (CUR0%, control), 100 mg/kg (CUR0.01%), and 200 mg/kg (CUR0.02%), respectively. Each diet was randomly assigned to triplicate groups of 15 fish per tank. At the end of the feeding experiment, dietary curcumin supplementation positively modulated antioxidant-related genes and enzyme activity in liver tissues. After the ammonia challenge, dietary supplementation with the appropriate level of curcumin alleviated ammonia stress in liver tissue by upregulating the relative expression of GSH-Px and downregulating the relative expression of Keap1 and GR. Meanwhile, ammonia stress in spleen tissue could also be alleviated by upregulating the relative expression of CAT, downregulating the relative expression of GR, and increasing the activity of SOD and GSH. After the recovery, dietary supplementation with curcumin still alleviated ammonia stress in the liver tissue by upregulating the relative expression of CAT, downregulating the relative expression of Keap1 and GR, and increasing the activity of SOD and GSH. On the other hand, ammonia stress in spleen tissue was still alleviated by upregulating the relative expression of Mn-SOD and increasing the activity of SOD and GSH. The histological structure results also showed that liver cells in the curcumin-containing groups exhibited a positive impact on cell boundaries, alignment, and nuclei after the ammonia challenge and recovery. Spleen cells in the curcumin-containing groups exhibited greater aggregation of melano-macrophage centers after the ammonia challenge and recovery. These results suggest that dietary curcumin supplementation at 100 mg/kg can promote the health condition and resistance to ammonia stress of the greater amberjack.

In order to reveal the acute toxicity and physiological changes of the spotted babylon (Babylonia areolata) in response to environmental manipulation, the spotted babylon was exposed to three pH levels (7.0, 8.0 and 9.0) of seawater and four concentrations of nitrite nitrogen (0.02, 2.7, 13.5 and 27 mg/L). The activities of six immunoenzymes, superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), catalase (CAT), acid phosphatase (ACP), alkaline phosphatase (AKP) and peroxidase (POD), were measured. The levels of pH and nitrite nitrogen concentrations significantly impacted immunoenzyme activity over time. After the acute stress of pH and nitrite nitrogen, the spotted babylon appeared to be unresponsive to external stimuli, exhibited decreased vigor, slowly climbed the wall, sank to the tank and could not stand upright. As time elapsed, with the extension of time, the spotted babylon showed a trend of increasing and then decreasing ACP, AKP, CAT and SOD activities in order to adapt to the mutated environment and improve its immunity. In contrast, POD and GSH-PX activities showed a decrease followed by an increase with time. This study explored the tolerance range of the spotted babylon to pH, nitrite nitrogen, and time, proving that external stimuli activate the body’s immune response. The body’s immune function has a specific range of adaptation to the environment over time. Once the body’s immune system was insufficient to adapt to this range, the immune system collapsed and the snail gradually died off. This study has discovered the suitable pH and nitrite nitrogen ranges for the culture of the spotted babylon, and provides useful information on the response of the snail’s immune system.

The hierarchical structures of biological materials endow them with excellent mechanical performance and specific functionality. Interestingly, structures are formed under the functions of biological systems under mild conditions, which inspires the synthesis and fabrication of artificial materials at room temperature. During the formation of biological structures, biotemplating effects play critical roles, such as confined environments, surface functional groups, molecular conformation, and self-assembly behavior. Based on these functional characteristics, many studies have focused on choosing biological templates that are abundant in nature and easy to obtain or to design customized biological templates based on pristine biotemplates to realize the formation of organized structures and the optimized performance of materials. In this review, we summarize the four types of biotemplates, including collagen, cellulose, viruses, and bacteria, for the synthesis of organized structures. Benefiting from this review, the effects of biotemplating on artificial material synthesis will receive more attention from researchers and will contribute to the synthesis of new materials and structures.

This study sought to characterize the effect of density stress on greater amberjack (Seriola dumerili) survival to determine an optimal transport density. To achieve this, this experiment simulated the transport conditions of fish (body length: 4.09 ± 1.00 cm; weight: 0.9 ± 0.05 g) using closed oxygen transport at 5 different densities (D1 = 1.125 kg/m3, D2 = 2.25 kg/m3, D3 = 3.375 kg/m3, D4 = 4.5 kg/m3, and D5 = 6.75 kg/m3) for 8 hours, after which biochemical indicators, stress, metabolism, and antioxidant capacity were evaluated. After 8h, only the D1 and D3 groups exhibited survival rates above 90%. The pH of the water decreased with density, whereas the ammonia nitrogen and nitrite increased with density. Cortisol (COR) levels were not significantly different among all the groups, but tended to increase with increasing density. In this study, COR is a relatively stable index with the increase in density, but in D3 group, the change of COR will not cause the change of immune-related genes, so COR can inhibit the expression of immune genes within a certain density. The D3 density group exhibited the highest catalase (CAT) and glutathione peroxidase glutathione peroxidase (GSH‐PX) levels. In addition, the expression levels of immune related factor interleukin-1β (IL-1β), tumor necrosis factor (TNF-α), major histocompatibility complex (MHC-1) and nuclear factor kappa-B (NF-KB1) were the lowest in D3 density group. The density of fish during transportation significantly affects water quality, metabolism, and immunity. During transportation, assuming that the plastic bags are airtight to ensure aerobic conditions and that the transportation time is within 8 h, transport density should be maintained at approximately 3.375 kg/m3.

In the study, the parasite from the yellowfin tuna (Thunnus albacares) was separated, and morphological observation and molecular identification were carried out. Our results showed that the parasite was similar to Pennella sp. Its cephalothorax was covered by spherical to spherical non-branched nipples of almost the same size, which were very similar in shape and arrangement. A pair of slightly larger, the unbranched antenna was present on the outer margin of the small papillae-covered area. The gene sequence of COX1 with a length of 1,558 bp in the mitochondria of the parasite was 100% similar to Pennella sp. (MZ934363). The mitochondrial genome had a total length of 14,620 bp. It consisted of 36 genes (12 protein-coding, 22 transfer RNAs and 2 ribosomal RNAs) and a dummy control region, but the mitochondrial genome had no ATP8 gene. Morphological observation showed that Pennella sp. was dark red, with a convex cephalothorax, with a total length of 8.42 cm, parasitic on the dorsal side of yellowfin tuna. Pennella sp. included the cephalothorax, neck, trunk, abdomen and egg belt. This study was the first report on the mitochondrial genome of Pennella sp. The results provide basic data for further identifying the parasites of Pennella genus.

Collagen fibrils hierarchically assemble from microscale to macroscale, which endows the natural composite bone with good mechanical properties and remodeling functions. Revealing the intrafibrillar growth process of hydroxyapatite nanocrystals of collagen will guide the research of bone repair or collagen-based composites. Herein, we investigated the mineralization of multiscale collagen matrices and strongly proved the intrafibrillar hydroxyapatite nanocrystals in the collagen fibrils. The hydroxyapatite nanocrystals were deposited within collagen fibrils with co-orientation along the (002) crystal plane, which is the longitude of the fibril. The whole growth process was captured by TEM to demonstrated the five stages of the intrafibrillar growth process of hydroxyapatite nanocrystals. The infiltration and transformation of amorphous calcium phosphate in isolated collagen fibrils are both demonstrated. The intrafibrillar growth process of hydroxyapatite nanocrystals in collagen film was also investigated, showing that the growth area of collagen films increased linearly with time and the growth process. By studying the in situ mineralization under different reaction conditions, the kinetic equation of the mineralized area of collagen film under each condition was obtained, and the optimal hydroxyapatite mineralized solution was proved to be a solution with polyacrylic acid of 50 μG/mL and a pH of 7.5. Our work provides more detailed information of the growth process of HAP nanocrystals during the mineralization of collagen at different scales and would contribute to future research on the formation process of more minerals in collagen.

Developing non-precious catalysts as Pt substitutes for electrochemical hydrogen evolution reaction (HER) with superior stability in acidic electrolyte is of critical importance for large-scale, low-cost hydrogen production from water. Herein, we report a CoCrFeNiAl high-entropy alloy (HEA) electrocatalyst with self-supported structure synthesized by mechanical alloying and spark plasma sintering (SPS) consolidation. The HEA after HF treatment and in situ electrochemical activation for 4000 cycles of cyclic voltammetry (HF-HEAa2) presents favourable activity with overpotential of 73 mV to reach a current density of 10 mA cm−2 and a Tafel slope of 39.7 mV dec−1. The alloy effect of Al/Cr with Co/Fe/Ni at atomic level, high-temperature crystallization, as well as consolidation by SPS endow CoCrFeNiAl HEA with high stability in 0.5 M H2SO4 solution. The superior performance of HF-HEAa2 is related with the presence of metal hydroxides/oxides groups on HEA.

In order to understand the effects of dietary curcumin on the growth and digestive performance of Seriola dumerili, this study was conducted under laboratory conditions. The control group was added with 0% curcumin, and two treatment groups were added with 0.01% and 0.02% curcumin, respectively. Fish were fed with experimental diet for 8 weeks. The growth data, growth genes, intestinal digestive enzymes, tissue parameters, and blood lipid-related indicators were measured, and the correlation between digestive indicators, growth gene indicators, and growth characteristic indicators was analyzed. The results showed that the survival rate, visceral ratio, hepatosomatic ratio, and condition factor of Seriola dumerili increased first and then decreased with the increase of curcumin content in feed. The feed conversion ratio of the control group was significantly higher than that of the treatment group. With the increase of curcumin content in feed, lipase and trypsin increased first and then decreased with the increase of curcumin content. Compared with the control group, curcumin significantly increased the muscle thickness and the number of goblet cells of Seriola dumerili. High and low contents of curcumin can reduce the content of serum total cholesterol and triglyceride, and a low dose (0.01%) of curcumin has the strongest lipid-lowering effect. The relative gene expression of IGF1 and IGF2 reached the maximum in the 0.02% treatment group. The results showed that the addition of curcumin in feed could theoretically improve the survival rate, feed efficiency, and other growth characteristics of Seriola dumerili, improve intestinal digestion and structure, promote intestinal health, and reduce blood lipid levels. The best effect was achieved in the 0.01% treatment group. The results of this study provide a theoretical reference for the feasibility of adding curcumin to Seriola dumerili feed in production and realize the optimal proportion of feed additives for this species, which is beneficial to the sustainable development of aquaculture.

Abstract Zirconium diboride (ZrB2) is considered as one of the most promising ultra‐high temperature materials for the applications in extreme environments. However, the difficulty in fabrication of ZrB2 limits its industrial applications. In this study, fully dense and grain‐refined ZrB2 is prepared under ultra‐high pressure of 15 GPa at low temperature of 1450 °C. The as‐prepared ZrB2 exhibits excellent mechanical and oxidation‐resistant properties. Compared with raw powder, the grain size decreases 56%. Compared with high‐temperature sintered control specimen beyond 2000 °C, the hardness and fracture toughness increase about 46% and 69%, respectively, the dislocation density increase 3 orders of magnitude, while the grain size considerably decrease 96%. According to work hardening, Hall–Petch and Taylor dislocation hardening effects, the refined grains, substructures, and high dislocation density caused by plastic deformation during sintering can enhance the mechanical properties. The unique structure contributes to a threshold oxidation temperature increase of ≈250 °C relative to the high‐temperature sintered ZrB2, achieving one of the highest values (1100 °C) among the reported monolithic ultra‐high temperature ceramics. A developed densification mechanism of dislocation multiplication with grain refining is proposed and proved to dominate the sintering, which is responsible for simultaneous improvements in mechanical and oxidation‐resistant properties.

This study was conducted to understand the changes of physiological and biochemical indexes of black and red shell Pinctada fucata under acute high and low salt stress. In this study, the salinity of 35‰ was used as the control, while the salinities of 20 and 50% salinity were used as the low and high salt treatment groups, respectively. The osmotic pressure (OSM) and ion concentration in the hemolymph, Na+-K+ -ATPase (NKA) activity and respiratory metabolism in gills, and antioxidant and immune (non) enzymes in the hepatopancreas of P. fucata with two shell colors were compared and analyzed at the time periods of 1.5 and 3 h post-salinity stress. The results showed that the OSM and inorganic ion (Na+, Ca2+, and Cl–) concentration in the hemolymph of the black and red P. fucata increased significantly with the increase of salinity after the time periods of 1.5 and 3 h. At 3 h, the black P. fucata NKA activity decreased significantly with the increase of salinity, while red P. fucata reached the highest value at high salinity. The succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH) activities of red P. fucata showed U-shaped and inverted U-shaped distributions with the increase of salinity after 1.5 h, respectively. With the increase of salinity, the phenoloxidase (POX) activity of red and black P. fucata showed inverted U-shaped and U-shaped distributions, respectively. The contents of glutathione (GSH) and vitamin C (VC) in black P. fucata decreased significantly with the increase of salinity at 1.5 and 3 h. Red P. fucata GSH and VC reached their maximum value in the 1.5-h low salinity group and 3-h high salinity group. The vitamin E (VE) content in black P. fucata increased significantly with the increase of salinity at 1.5 h, and reached the maximum at 3 h in the control group. Red P. fucata VE reached the maximum at 1.5 and 3 h in the control group. The results obtained from the present study revealed that the sensitivity of P. fucata to salinity varied in shell color. Compared to black P. fucata, red P. fucata responds more quickly to sharp salinity changes, thereby reducing more likely damage. Compared with a high salt environment, P. fucata was more adaptable to the changes of acute low salt environment. The results obtained from the present study provide the physical references for subsequent selective breeding of this species.

To understand the impacts of salinity stress on the antioxidation of yellowfin tuna Thunnus albacares, 72 fishes (646.52 ± 66.32 g) were randomly divided into two treatments (32‰ and 29‰) and sampled at four time points (0 h, 12 h, 24 h, and 48 h). The salinity of the control group (32‰) was based on natural filtered seawater and the salinity of the stress group (29‰) was reduced by adding tap water with 24 h aeration to the natural filtered seawater. The superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) from liver, gill, and muscle tissues were used as the antioxidant indexes in this study. The results showed that the changes of SOD and GSH-Px in the gills were first not significantly different from the control group (p > 0.05) and finally significantly higher than the control group (SOD: 50.57%, GSH-Px: 195.95%, p < 0.05). SOD activity in fish liver was not significantly changed from 0 h to 48 h (p > 0.05), and was not significantly different between the stress group and control group (p > 0.05). With the increase in stress time, GSH-Px and MDA activities in the liver of juvenile yellowfin tuna increased first (GSH-Px: 113.42%, MDA: 137.45%) and then reduced (GSH-Px: −62.37%, MDA: −16.90%) to levels similar to the control group. The SOD activity in the white and red muscle of juvenile yellowfin tuna first decreased (white muscle: −27.51%, red muscle: −15.52%) and then increased (white muscle: 7.30%, red muscle: 3.70%) to the level of the control group. The activities of GSH-Px and MDA in white and red muscle increased first (white muscle GSH-Px: 81.96%, red muscle GSH-Px: 233.08%, white muscle MDA: 26.89%, red muscle MDA: 64.68%) and then decreased (white muscle GSH-Px: −48.03%, red muscle GSH-Px: −28.94%, white muscle MDA: −15.93%, red muscle MDA: −28.67%) to the level observed in the control group. The results from the present study indicate that low salinity may lead to changes in the antioxidant function of yellowfin tuna juveniles. In contrast, yellowfin tuna juveniles have strong adaptability to the salinity of 29‰. However, excessive stress may consume the body’s reserves and reduce the body’s resistance.

Acidized water environment can impact many physiological processes of aquatic animals. The response of the head kidney to acidification, especially the immune response, is of great significance to health. This study analyzed the histological and transcriptional changes under different acidification levels (C group, pH 8.1; P group, pH 7.4; E group, pH 3.5) in the short term (12 h, 36 h and 60 h) in the head kidney of juvenile L. calcarifer. The results showed that the acidification of the water environment caused tissue damage to the head kidney of L. calcarifer, and the damage appeared earlier and was stronger in the extreme pH group. The transcriptional response of L. calcarifer head kidney increased with the increase of acidification level. The two treatments transcriptional responses showed different trends in terms of time. After KEGG function enrichment, with the increase of stimulation time, the proportion of down-regulated pathways was increasing, and the types of pathway enrichment at different acidification levels were quite different at the initial stage. At 12 h, the first category in the P group with the most significant number of pathways was ‘Metabolism’, and the first category in the E group with the largest number of pathways was ‘Human Diseases’. At 60 h, the enrichment pathways of the two groups were highly overlapping in immune-related pathways, which contained 26 common DEGs. They had a dominant expression pattern. In the P group, the expression level decreased with time. In the E group, the down-regulation degree of expression level at 12 h reached the level of the P group at 60 h, and the expression level remained low until 60 h. Through the correlation network, interferon regulatory factor 7 (IRF7), Tripartite motif containing-21 (TRIM21), Signal transducer and activator of transcription 1 (STAT1) and Signal transducer and activator of transcription 3 (STAT3) were found to have the most correlation with other genes. In this study, juvenile L. calcarifer showed different coping strategies to different levels of acute acidification stress, but all of them resulted in the extensive weakening of head kidney immune function.

In order to investigate the rhythmic changes in gene expression in the liver of mackerel tuna (Euthynnus affinis) under sunny and cloudy conditions, this experiment had four sampling times (6:00, 12:00, 18:00 and 24:00) set on sunny and cloudy days to determine the expression of their immune, metabolic and rhythmic genes. The results showed that daily rhythmicity was present within most of the rhythm genes (CREB1, CLOCK, PER1, PER2, PER3, REVERBA, CRY2 and BMAL1), metabolic genes (SIRT1 and SREBP1) and immune genes (NF-kB1, MHC-I, ALT, IFNA3, ISY1, ARHGEF13, GCLM and GCLC) in this study under the sunny and cloudy condition (p < 0.05). The expression levels of CREB1, PER1, PER3, RORA, REVERBA, CRY1 and BMAL1 within rhythm genes were significantly different (p < 0.05) in the same time point comparison between sunny and cloudy conditions at 6:00, 12:00, 18:00 and 24:00; metabolic genes had the expression levels of LPL at 6:00, 12:00, 18:00 and 24:00 in the same time point comparison (p < 0.05); immune genes only had significant differences in the expression levels of IFNA3 at 6:00, 12:00, 18:00 and 24:00 (p < 0.05). This study has shown that rhythm, lipid metabolism and immune genes in the livers of mackerel tuna are affected by time and weather and show significant changes in expression.

To understand the physiological reactions of juvenile yellowfin tuna (Thunnus albacares) under acute high-temperature stress, this study measured the changes in biochemical indexes of serum, liver, gill, and muscle of yellowfin tuna under acute high-temperature stress (HT, 34 °C) and a control group (28 °C) for 0 h and 6 h, 24 h and 48 h. The rising speed of water temperature in the HT group was 2 °C/h and the timing started when the temperature reached 34 °C. In the HT group, there was no significant difference between the four adjacent times in cortisol and lactic acid concentration. Serum triglyceride, cholesterol, and alkaline phosphatase concentration were significantly different from the four adjacent times. The superoxide dismutase (SOD) activity in the liver and gills increased at 6 h and 24 h, and the gills and liver had antioxidant reactions in a short time. The malondialdehyde (MDA) concentration in the gills changed significantly at 6 h, while that in the liver did not change significantly. The gills were more sensitive to temperature stress than the liver and muscle. Acute high-temperature stress affected yellowfin tuna’s antioxidant enzymes and metabolic indexes, resulting negative trend in physiological indexes, indicating that yellowfin tuna juveniles are susceptible to elevated temperature.

This study was conducted to determine whether curcumin has a positive effect in greater amberjack (Seriola dumerili), especially the ammonia nitrogen stress tolerance ability. The results showed that the stress recovery process of digestive enzymes amylase and trypsin, as well as absorptive enzymes Na+/K+-ATPase, γ-GT and CK, was accelerated. Lysozyme activity increased in the fish fortified with both curcumin diets. Aspartate aminotransferase activity restriction was activated at a low curcumin level. However, alanine aminotransferase activity restriction happened only at 0.02% dietary curcumin. Facilitation of lipid metabolism by curcumin was very clear, as triglyceride and total cholesterol content was basically maintained at the original level or even showed a slight decrease after recovery. HSP70 and HSP90 genes were not evidently stimulated to express in liver, kidney and spleen tissues. In addition, curcumin showed its inhibition capacity on IL1β and IFN-γ and a promoting effect on TGF-β1. The expression of NF-κB1 decreased in a higher degree in fish fed with 0.02% dietary curcumin, while 0.01% dietary curcumin accelerated the recovery pace of C3 and lgT after stress. This study showed that dietary curcumin supplementation can enhance ammonia nitrogen stress tolerance in greater amberjack, and its application prospect can be confirmed.

This study investigated the effects of added eugenol on water quality and the metabolism and antioxidant capacity of the liver and gills of the greater amberjack (Seriola dumerili) during simulated transport. The juvenile fish (10.34 ± 1.33 g) were transported in sealed plastic bags containing different eugenol concentrations at a density of 24.79 kg/m3 for 8 h. The different eugenol concentrations were divided into five groups: 0 μL/mL (control group), 0.0125 μL/mL, 0.025 μL/mL, 0.0375 μL/mL, and 0.05 μL/mL, with three replicates of each. The results showed that 0.05 μL/mL of eugenol could significantly increase dissolved oxygen, but 0.025 μL/mL–0.0375 μL/mL resulted in a significant decrease in dissolved oxygen and significant increases in NH4+-N and NO2−-N. It was found that 0.05 μL/mL of eugenol caused significant up-regulation of the relative expression of CPT-1 in the liver, significant down-regulation of the relative expression of FAS and PK in the liver and gills, a significant increase in glycogen concentration, and a significant decrease in glucose concentration. This suggests that 0.05 μL/mL of eugenol could reduce the metabolic capacity of fish. In addition, 0.05 μL/mL of eugenol caused significant up-regulation of the relative expression of CAT and a significant decrease of MDA concentration in the liver. Meanwhile, the gills showed significant up-regulation of CAT relative expression, significant down-regulation of Keap1 relative expression, and a significant increase in GSH activity, resulting in a significant increase in MDA concentration when the concentration of eugenol reached or exceeded 0.025 μL/mL. This suggests that 0.05 μL/mL eugenol could improve the antioxidant capacity of fish and lipid peroxidation levels in the gills. In conclusion, the addition of 0.05 μL/mL eugenol could improve water quality, and the metabolic and antioxidant capacities of liver and gills, but it could also increase lipid peroxidation levels in the gills under transport conditions.

Changes in temperature and salinity of the marine environment fluctuate continuously, and the effects of these changes on shellfish survival are significant. In this study, the survival rate of adult Asian green mussels (Perna viridis) was measured after short-term treatments (7 days) for a range of temperature (20 °C, 25 °C, 30 °C) and salinity (23‰, 28‰, 33‰). The digestive (amylase, lipase, trypsin and pepsin activities) and antioxidant performance (SOD and GPX gene expression; SOD, GPX and CAT activities; GSH and MDA Concentration) were measured and MANOVA results were obtained using a generalized linear model between certain factors (temperature (T), salinity (S) and temperature × salinity (T × S)) and survival rate. Both T and T × S significantly affected the survival rate of Asian green mussels. The overall relationship between the survival rate of P. viridis and T and S within the experimental range can be summarised by the equation: ln(Survival rate) = 54.9282 − 2.5627 × T − 3.6180 × S + 0.1857 × T × S + 0.0156 × T2 + 0.0520 × S2 − 0.0012 × T2 × S − 0.0023 × T × S2. The optimal temperature–salinity combination was 23.698 °C/30.760‰. T, S and T × S all had a significant impact on amylase and lipase activities of Asian green mussels. In the hepatopancreas, gill, mantle, adductor muscle, gonad and foot tissues of Asian green mussel, the SOD and GPX gene expression were responsive to temperature–salinity changes. The antioxidant performance of the combinations far from the optimal temperature–salinity combination were significantly improved. Our results suggest that combined temperature and salinity effects have a regular impact on the survival of Asian green mussels and that there is a link between survival and digestive and antioxidant performance.

A water environment can impact many physiological processes of aquatic animals. The antioxidant response of immune system of the pearl oyster to temperature and salinity is of great significance to health. This study analyzed the physiological changes and immune responses under different temperature and salinity levels (temperature: 20, 25, and 30 °C; salinity: 23, 28, and 33‰) in the short term (7 d) in the hepatopancreas and other tissues of 405 pearl oysters. The combined effects of temperature and salinity on antioxidants in the immune system of the pearl oyster were evaluated via response surface methodology and Box–Benhnken design (BBD) under laboratory conditions. The secondary effects of salinity on the activities of glutathione peroxidase (GSH-PX), catalase (CAT), and superoxide dismutase (SOD) were significant, and CAT and SOD showed an inverted U-shaped trend with the increase in salinity. Temperature significantly impacted GSH-PX, CAT, glutathione (GSH), and SOD in primary and secondary effects, and the maximum values of CAT, GSH, and SOD were observed. The phenoloxidase (POX) and alkaline phosphatase (AKP) activities increased with the increasing temperatures. The interaction of temperature and salinity was significant on CAT and SOD, but was not significant on GSH-PX. The interaction between salinity and temperature on AKP was significant, which was contrary to the results of AKP in the hemolymph. The expression levels of antioxidant genes varied between tissues, and the expression levels of different genes in the same tissue were different. Appropriate immunity and antioxidant index models were established under the combined temperature and salinity conditions. The optimal combination of temperature and salinity was 24.95 °C and 28.11‰, respectively, and the desirability was 0.803. This study provides theoretical reference points for the pearl oyster to respond to temperature and salinity changes and can be used to establish an index model for shellfish aquaculture.

Tungsten heavy alloy (WHA) is an ideal material employed for kinetic energy penetrators due to its high density and excellent mechanical properties. However, it is difficult to obtain ultrafine-grained tungsten alloy with excellent properties by traditional powder metallurgy method because of severe grain growth at a high sintering temperature with a long soaking time. In this study, the sintering behavior of tungsten alloys was studied at 800 to 1300 °C, and highly dense 93W-5.6Ni-1.4Fe (wt.%) WHA was successfully fabricated at a low temperature of 950 °C with a high pressure of 150 MPa by spark plasma sintering. The as-sintered tungsten alloy possesses a high relative density (98.6%), ultrafine grain size (271 nm) and high dislocation density (2.6 × 1016 m−2), which results in excellent properties such as a high hardness (1079 HV1). The high sintering pressure is considered to support an additional driving force for the sintering and lead to a low-temperature densification, which effectively limits grain growth.

In order to investigate the molecular response pattern of golden pompano Trachinotus ovatus larvae under cold and heat stress, transcriptome sequencing was performed in three temperature-treated groups (24 °C, low temperature, LT; 28 °C, moderate temperature, MT; and 32 °C, high temperature, HT) after one week of treatment. A total of 501,367,768 clean reads were obtained, with an average GC content of about 47 %. 94,144 unigenes were recovered, with an average length of 1045 bp. Gene ontology (GO) analysis and Kyoto encyclopedia of genes and genomes (KEGG) analysis showed that a large number of differentially expressed genes were related to metabolic processes, protein synthesis and nutrient digestion and absorption. The differentially expressed genes (DEGs) were most highly enriched into the pathways including protein digestion and absorption, fat digestion and absorption, starch and sucrose metabolism, vitamin digestion and absorption, glutathione metabolism. High temperature may inhibit the secretion of type II collagen by down-regulating the expression of Shh and Sox9a genes. The results of this study provide important support for understanding mechanism of the response to high temperature in Trachinotus ovatus and guiding relevant production practices.

This study compares salinity tolerance between red and black shell Pinctada fucata salinity stress of 20 and 50‰, while 35‰ was used as a control. The hemolymph osmotic pressure, inorganic ion concentration, the activities of Na+-K+ -ATPase, respiratory metabolism related enzymes and liver tissue antioxidant related enzymes were measured at 12 and 24 h after salinity stress. The osmotic pressure and inorganic ion concentration of hemolymph of two strains P. fucata increased significantly with the increase of salinity. The activity of Na+-K+ -ATPase of red P. fucata only decreased under low salinity at 24 h, and was significantly higher than that the control under low salinity at 12 h and high salinity at 12 and 24 h. The succinate dehydrogenase (SDH) activities of the P. fucata treatment groups were significantly higher than those the control at 12 h. The lactate dehydrogenase (LDH) activity increased significantly with salinity at 12 h. and the black P. fucata LDH activity was significantly higher than the control at 24 h, while the LDH activity of red P. fucata was significantly lower than that the control in 50‰ salinity. The superoxide dismutase (SOD) activity of black P. fucata was significantly lower than that the control, while that of red P. fucata was significantly higher than that the control within 24. At 12 h, the catalase (CAT) activity of red P. fucata increased significantly with salinity, but decreased significantly with salinity at 24 h. The CAT activity of black P. fucata was highest at 24 h under low salinity. Glutathione peroxidase (GSH-Px) and alkaline phosphatase (AKP) activities of red P. fucata were significantly higher than those the control under low or high salinity. At high salinity for 24 h, the GSH-Px activity was lowest in black P. fucata, AKP activity was highest. The present study indicates that the physical responses of P. fucata to the salinity stress vary with shell colors. The red P. fucata can quickly respond positively to the change of environmental salinity and reduce the damage caused by the change of environmental salinity.

To elucidate the possible molecular reaction of vertebral fusion in juvenile golden pompano at high temperature, we examined the changes in growth, vertebral fusion incidence, histological differences and transcription levels of genes related to bone development in juvenile golden pompano at 27 and 33°C for 30 days, respectively. The growth rate of juvenile fish was faster when the water temperature was 33°C, but the incidence of vertebral fusion was higher. Prolonged high water temperature reduced the osteogenic layer in the growth zone of the vertebral endplate and the elastic externa. The endplate growth areas of the fused vertebrae were transformed into cartilage tissue, which was then remodeled into bone. The intervertebral notochord tissue was transformed into bone and the intervertebral space disappeared. In normal phenotypes of vertebrae, short-term high temperature could promote the expression of genes related to cartilage differentiation and maturation, as well as genes related to osteoblastic differentiation. With the increase of culture time, the expression of genes related to cartilage and osteogenesis development was inhibited. In fused vertebrae, cartilage proliferation was enhanced, osteogenic differentiation was inhibited, and matrix mineralization may be enhanced. Genes associated with the development of chondrocytes and osteoblasts in the vertebrae of juvenile Trachinotus ovatus were significantly regulated by temperature and time. The results may contribute to further understanding of the occurrence of vertebral fusion at high temperature.

This study evaluated the effects of different dietary non-protein energy sources on hepatic metabolism and endocrine of barramundi. Fish were fed iso-energy diets (18 MJ kg–1) with two types of non-protein energy source in the experimental group and a regular diet was used as the control. The feeding trial lasted 56 days. In the present study, CPT1 and SCD expression in fish fed high lipid diet were upregulated and liver lipid metabolism was more active than the control group. Serum biochemical parameters including serum glucose, serum triacylglycerol and serum cholesterol were significantly increased. The IGF-I and IGF-II expressions were significantly upregulated, and growth performances were improved in fish fed the high lipid diet. When barramundi were fed with the high carbohydrate diet, GK expression was downregulated and cPEPCK expression was upregulated, indicating that glycogen might accumulate in liver. The fluctuation of serum biochemical parameters and the growth performance were not significantly different compared to the control group. In conclusion, high lipid diet can shorten the raising period, but it causes the change of metabolic level and the increase of useless adipose tissue; The high carbohydrate diet did not significantly improve the growth performance, and no significant metabolic abnormalities were observed, indicating that carbohydrate has the potential to be the feed energy supply source for juvenile barramundi. The results provide insights for further understanding the availability of non-protein energy sources in the diet of juvenile barramundi.

This study evaluated the effects of rotifers enriched with three enhancement products (Nannochloropsis, S.presso, and Algamac 3080) on the body fatty acid composition, growth, survival, jaw deformity, and bone development-related gene expression of the golden pompano larvae. The rotifers enriched with Nannochloropsis were rich in EPA, and the rotifers enriched with S.presso and Algamac 3080 were rich in docosahexaenoic acid (DHA). The level of DHA in Algamac 3080 is higher than that in S.presso. The first feeding started at 3 DPH, and data were collected at 8 DPH. The results showed that the body fatty acid composition of the larvae was basically the same as that of the feeding rotifers. The specific growth rate of S.presso and Algamac 3080 treatment was significantly higher than the un-enriched treatment (P < 0.05). The survival rate of Algamac 3080 treatment was significantly lower than the other treatments (P < 0.05), and the jaw deformity rate of S.presso treatment was significantly lower than the Nannochloropsis and un-enriched treatment (P < 0.05). The expression level of BMP2 and BMP4 in golden pompano larvae were not significantly affected by the enhancement products (P > 0.05), and the expression level of RXRα decreased significantly in the S.presso and Algamac 3080 treatment (P < 0.05). This study indicates that S.presso was an enhancement product more suitable for rotifers for golden pompano larvae. This study provided reliable reference and guidance for the first feeding of golden pompano larvae and also provided more reference data for the study of the mechanism of diet on larval fish bone deformity.

Hydrogels of flexibility, strength, and conductivity have demonstrated broad applications in wearable electronics and soft robotics. However, it is still a challenge to fabricate conductive hydrogels with high strength massively and economically. Herein, a simple strategy is proposed to design a strong ionically conductive hydrogel. This ion-conducting hydrogel was obtained under the synergistic action by salting out the frozen mixture of polyvinyl alcohol (PVA) and graphene oxide (GO) using a high concentration of sodium chloride solution. The developed hydrogel containing only 5 wt% PVA manifests good tensile stress (65 kPa) and elongation (180%). Meanwhile, the PVA matrix doped with a small amount of GO formed uniformly porous ion channels after salting out, endowed the PVA/GO hydrogel with excellent ionic conductivity (up to 3.38 S m−1). Therefore, the fabricated PVA/GO hydrogel, anticipated for a strain sensor, exhibits good sensitivity (Gauge factor = 2.05 at 100% strain), satisfying working stability (stably cycled for 10 min), and excellent recognition ability. This facile method to prepare conductive hydrogels displays translational potential in flexible electronics for engineering applications.

Abstract To investigate the possible effects of sulfamonomethoxine (SMM) on Nile tilapia (Oreochromis niloticus), we quantitatively evaluated the microbial shifts in the intestines of Nile tilapia in response to different doses of SMM (200 and 300 mg/kg) using 16S rRNA gene sequencing. At the phylum level, the control group (0 mg kg−1 SMM) was dominated by Actinobacteria, Proteobacteria, and Firmicutes. In the treatment groups, Firmicutes, Proteobacteria, and Chloroflexi were the dominant phyla. Cluster analysis indicated that the two groups treated with SMM clustered together. Similarly, the bacterial families that dominated the control group differed from those dominating the treatment groups. The changes in intestinal microbial composition over time were similar between the two SMM treatment groups. In both groups, the abundances of some families, including the Bacillaceae, Streptococcaceae, and Pseudomonadaceae, increased first and then decreased. Overall, the addition of SMM to the feed changed the structure of the intestinal microbiota in Nile tilapia. This study improves our understanding of the impact of SMM on the intestinal microenvironment of Nile tilapia. Our results provide guidelines for the feasibility of SMM use in aquaculture production.

Almost fully dense pure alumina could be prepared by fast firing (FF) at a high temperature (greater than 1689 °C) and a high heating rate (∼350 °C/s) with a whole sintering cycle in approximately 2 min without pressure. Dynamics of the ultrafast densification was explored by comparing the densifying characters of FF sintering and conventional sintering. Results show that overlapping of surface/grain boundary diffusion and lattice diffusion caused by the high heating rate, as well as rapid migration of nanoscale particles caused by the high heating rate and the sufficiently high sintering temperature, leads to the ultrafast densification, which differs from conventional time-cost material diffusion. The ultrafast densification dynamics is expected to be helpful for understanding or developing new fast sintering methods for ceramics.