High-Density Cationic Defects Coupling with Local Alkaline-Enriched Environment for Efficient and Stable Water Oxidation.

The inferior activity and stability of non-noble metal-based electrocatalysts for oxygen evolution reaction (OER) seriously limit their practical applications in various electrochemical energy conversion systems. Here we report, a drastic nonequilibrium precipitation approach to construct a highly disordered crystal structure of layered double hydroxides as a model OER catalyst. The unconventional crystal structure contains high-density cationic defects coupled with a local alkaline-enriched environment, enabling ultrafast diffusion of OH- ions and thus avoiding the formation of a local acidic environment and dissolution of active sites during OER. An integrated experimental and theoretical study reveals that high-density cationic defects, especially di-cationic and multi-cationic defects, serve as highly active and durable catalytic sites. This work showcases a promising strategy of crystal structure engineering to construct robust active sites for high-performance oxygen evolution in an alkaline solution.

Ion/Electron Redistributed 3D Flexible Host for Achieving Highly Reversible Li Metal Batteries.

3D carbon frameworks are promising hosts to achieve highly reversible lithium (Li) metal anodes, whereas insufficient effects are attributed to their single electron conductivity causing local aggregating of electron/Li+ and uncontrollable Li dendrites. Herein, an ion/electron redistributed 3D flexible host is designed by lithiophilic carbon fiber cloth (CFC) modified with metal-organic framework (MOF)-derived porous carbon sheath with embedded CoP nanoparticles (CoP-C@CFC). Theory calculations demonstrate the strong binding energy and plenty of charge transfer from the reaction between CoP and Li atom are presented, which is beneficial to in situ construct a Li3 P@Co ion/electron conductive interface on every single CoP-C@CFC. Thanks to the high ionic conductive Li3 P and electron-conductive Co nanoparticles, the rapid dispersion of Li+ and obviously reduced local current density can be achieved simultaneously. Furthermore, in situ optical microscopy observations display obvious depression for volume expansion and Li dendrites. As expected, a miraculous average Coulombic efficiency (CE) of 99.96% over 1100 cycles at 3 mA cm-2 and a low overpotential of 11.5 mV with prolonged cycling of over 3200 h at 20% depth of discharge are successfully obtained. Consequently, the CoP-C@CFC-Li||LiFePO4 full cells maintain a capacity retention of 95.8% with high CE of 99.96% over 500 cycles at 2 C and excellent rate capability.

Defect engineering of metal-oxide interface for proximity of photooxidation and photoreduction.

Close proximity between different catalytic sites is crucial for accelerating or even enabling many important catalytic reactions. Photooxidation and photoreduction in photocatalysis are generally separated from each other, which arises from the hole-electron separation on photocatalyst surface. Here, we show with widely studied photocatalyst Pt/[Formula: see text] as a model, that concentrating abundant oxygen vacancies only at the metal-oxide interface can locate hole-driven oxidation sites in proximity to electron-driven reduction sites for triggering unusual reactions. Solar hydrogen production from aqueous-phase alcohols, whose hydrogen yield per photon is theoretically limited below 0.5 through conventional reactions, achieves an ultrahigh hydrogen yield per photon of 1.28 through the unusual reactions. We demonstrated that such defect engineering enables hole-driven CO oxidation at the Pt-[Formula: see text] interface to occur, which opens up room-temperature alcohol decomposition on Pt nanoparticles to [Formula: see text] and adsorbed CO, accompanying with electron-driven proton reduction on Pt to [Formula: see text].

Effects of temperature, dissolved oxygen, and their interaction on the growth performance and condition of rainbow trout (Oncorhynchus mykiss).

The individual effects of temperature and dissolved oxygen (DO) on rainbow trout (Oncorhynchus mykiss), an important aquaculture species, are clearly established; however, little is known about the interactive effects of these parameters. In this study, the effects of temperature, DO, and their interaction on the growth, antioxidant status, digestive enzyme activity, serum biochemical parameters, and liver IGF-1 expression in rainbow trout were evaluated. Fish (initial weight, 109.98 ± 3.28 g) were reared in a recirculating system for 4 weeks and subjected to 6 treatments at three temperatures (13 °C, 17 °C, and 21 °C) and two DO contents (4.2 mg L-1 and 9.6 mg L-1). Physiological parameters were determined at the end of the trial. Specific growth rate and feed consumption were the highest at 17 °C and the lowest at 21 °C. Additionally, lysozyme, trypsin, lipase, and amylase activities, serum glucose and serum triglyceride contents, and IGF-1 expression decreased significantly at 21 °C and total serum protein and albumin contents were significantly higher at 21 °C than at 13 °C and 17 °C, indicating that high temperature impaired the immunity, digestion, and growth of rainbow trout. However, the adverse effects of high temperature can be alleviated by a high DO content, as evidenced by the smaller increments and decrements of these parameters under hyperoxic conditions than under hypoxic conditions. In response to high temperature stress, an increase in antioxidant enzyme activity led to the removal of oxygen free radicals under hyperoxic conditions; however, this increase was inhibited under hypoxia. Our results indicated that high temperatures have adverse effects on rainbow trout, and these harmful effects can be reduced by a high DO content.

Molecular engineering of organic electroactive materials for redox flow batteries.

With high scalability and independent control over energy and power, redox flow batteries (RFBs) stand out as an important large-scale energy storage system. However, the widespread application of conventional RFBs is limited by the uncompetitive performance, as well as the high cost and environmental concerns associated with the use of metal-based redox species. In consideration of advantageous features such as potentially low cost, vast molecular diversity, and highly tailorable properties, organic and organometallic molecules emerge as promising alternative electroactive species for building sustainable RFBs. This review presents a systematic molecular engineering scheme for designing these novel redox species. We provide detailed synthetic strategies for modifying the organic and organometallic redox species in terms of solubility, redox potential, and molecular size. Recent advances are then introduced covering the reaction mechanisms, specific functionalization methods, and electrochemical performances of redox species classified by their molecular structures. Finally, we conclude with an analysis of the current challenges and perspectives on future directions in this emerging research field.

Highly Efficient Photoelectrochemical Water Splitting from Hierarchical WO3/BiVO4 Nanoporous Sphere Arrays.

Nanoarchitecture of bismuth vanadate (BiVO4) photoanodes for effectively increasing light harvesting efficiency and simultaneously achieving high charge separation efficiency is the key to approaching their theoretic performance of solar-driven water splitting. Here, we developed hierarchical BiVO4 nanoporous sphere arrays, which are composed of small nanoparticles and sufficient voids for offering high capability of charge separation. Significantly, multiple light scattering in the sphere arrays and voids along with the large effective thickness of the BiVO4 photoanode induce efficient light harvesting. In addition, attributed to ultrathin two-dimensional Bi2WO6 nanosheets as the precursor, the synergy of various enhancement strategies including WO3/BiVO4 nanojunction formation, W-doping, and oxygen vacancy creation can be directly incorporated into such a unique hierarchical architecture during the one-step synthesis of BiVO4 without complex pre- or post-treatment. The as-obtained photoanode exhibits a water splitting photocurrent of 5.5 mA cm-2 at 1.23 V versus RHE under 1-sun illumination, among the best values reported up-to-date in the field.

Bi2MoO6 nanobelts for crystal facet-enhanced photocatalysis.

γ-Bi2MoO6 single-crystal nanobelts with dominant {010} facets exhibit facet-enhanced photocatalytic property for the photodegradation of dye pollutants under visible light irradiation. The charge carriers are more efficiently separated on the low-index facets due to the exposure of more photoactive sites to the reacting substrates.

Interaction of diet and the masou salmon Δ5-desaturase transgene on Δ6-desaturase and stearoyl-CoA desaturase gene expression and N-3 fatty acid level in common carp (Cyprinus carpio).

The masou salmon Δ5-desaturase-like gene (D5D) driven by the common carp ß-actin promoter was transferred into common carp (Cyprinus carpio) that were fed two diets. For P1 transgenic fish fed a commercial diet, Δ6-desaturase-like gene (D6D) and stearoyl-CoA desaturase (SCD) mRNA levels in muscle were up-regulated (P < 0.05) 12.7- and 17.9-fold, respectively, and the D6D mRNA level in the gonad of transgenic fish was up-regulated 6.9-fold (P < 0.05) compared to that of non-transgenic fish. In contrast, D6D and SCD mRNA levels in transgenic fish were dramatically down-regulated (P < 0.05), 50.2- and 16.7-fold in brain, and 5.4- and 2.4-fold in liver, respectively, in comparison with those of non-transgenic fish. When fed a specially formulated diet, D6D and SCD mRNA levels in muscle of transgenic fish were up-regulated (P < 0.05) 41.5- and 8.9-fold, respectively, and in liver 6.0- and 3.3-fold, respectively, compared to those of non-transgenic fish. In contrast, D6D and SCD mRNA levels in the gonad of transgenic fish were down-regulated (P < 0.05) 5.5- and 12.4-fold, respectively, and D6D and SCD mRNA levels in the brain were down-regulated 14.9- and 1.4-fold (P < 0.05), respectively, compared to those of non-transgenic fish. The transgenic common carp fed the commercial diet had 1.07-fold EPA, 1.12-fold DPA, 1.07-fold DHA, and 1.07-fold higher observed total omega-3 fatty acid levels than non-transgenic common carp. Although these differences were not statistically different (P > 0.05), there were significantly (P < 0.10) higher omega-3 fatty acid levels when considering the differences for all of the individual omega-3 fatty acids. The genotype × diet interactions observed indicated that the potential of desaturase transgenesis cannot be realized without using a well-designed diet with the needed amount of substrates.

Ternary Pt/SnO(x)/TiO2 photocatalysts for hydrogen production: consequence of Pt sites for synergy of dual co-catalysts.

A variety of ternary nanoheterostructures composed of Pt nanoparticles (NPs), SnOx species, and anatase TiO2 are designed elaborately to explore the effect of interfacial electron transfer on photocatalytic H2 evolution from a biofuel-water solution. Among numerous factors controlling the H2 evolution, the significance of Pt sites for the H2 evolution is highlighted by tuning the loading procedure of Pt NPs and SnOx species over TiO2. A synergistic enhancement of H2 evolution can be achieved over the Pt/SnOx/TiO2 heterostructures formed by anchoring Pt NPs at atomically-isolated Sn-oxo sites, whereas the Pt/TiO2/SnOx counterparts prepared by grafting single-site Sn-oxo species on Pt/TiO2 show a marked decrease in the rate of H2 evolution. The characterization results clearly reveal that the synergy of Pt NPs and SnOx species originates from the vectorial electron transfer of TiO2 → SnOx → Pt occurring on the former, while the latter results from the competitive electron transfer from TiO2 to SnOx and to Pt NPs.

Probiotics Mediate Intestinal Microbiome and Microbiota-Derived Metabolites Regulating the Growth and Immunity of Rainbow Trout (Oncorhynchus mykiss).

Emerging evidence confirms using probiotics in promoting growth and immunity of farmed fish. However, the molecular mechanisms underlying the host-microbiome interactions mediated by probiotics are not fully understood. In this study, we used rainbow trout (Oncorhynchus mykiss) as a model to investigate the internal mechanisms of host-microbiome interactions influenced by two probiotic bacteria, Bacillus velezensis and Lactobacillus sakei. We carried out experiments, including intestinal histology, serum physiology, and transcriptome and combined intestinal microbiome and metabolite profiling. Our results showed that both probiotics had a positive effect on growth, immunity, serum enzyme activity, the gut microbiome, and resistance to Aeromonas salmonicida in rainbow trout. Moreover, the intestinal microbial structure was reshaped with increased relative abundance of potential beneficial bacteria, such as Ruminococcus, Lachnospiraceae ucg-004, Leptotrichia, Bacillus coagulans, Porphyromonadaceae, Anaerococcus, and Photobacterium in the B. velezensis group and Paenibacillaceae and Eubacterium hallii in the L. sakei group. Metabolomic profiling and transcriptome analysis revealed upregulated metabolites as biomarkers, i.e., sucrose and l-malic acid in the B. velezensis group, and N-acetyl-l-phenylalanine, N-acetylneuraminic acid, and hydroxyproline in the L. sakei group. Additionally, a multiomics combined analysis illustrated significant positive correlations between the relative abundance of microflora, metabolites, and gene expression associated with immunity and growth. This study highlights the significant role of probiotics as effectors of intestinal microbial activity and shows that different probiotics can have a species-specific effect on the physiological regulation of the host. These findings contribute to a better understanding of the complex host-microbiome interactions in rainbow trout and may have implications for the use of probiotics in aquaculture. IMPORTANCE Probiotics are kinds of beneficial live microbes that impart beneficial effects on the host. Recent studies have proven that when given supplementation with probiotics, farmed fish showed improved disease prevention and growth promotion. However, the underlying metabolic functions regarding their involvement in regulating growth phenotypes, nutrient utilization, and immune response are not yet well understood in the aquaculture field. Given the active interactions between the gut microbiota and fish immune and growth performance, we conducted the supplementation experiments with the probiotics Bacillus velezensis and Lactobacillus sakei. The results showed that probiotics mediated intestinal microbiome- and microbiota-derived metabolites regulating the growth and immunity of fish, and different probiotics participated in the species-specific physiological regulation of the host. This study contributed to a better understanding of the functional interactions associated with host health and gut microbiota species.

Probing the electronic structure and photoactivation process of nitrogen-doped TiO2 using DRS, PL, and EPR.

The electronic structure and photoactivation process in N-doped TiO(2) is investigated. Diffuse reflectance spectroscopy (DRS), photoluminescence (PL), and electron paramagnetic resonance (EPR) are employed to monitor the change of optical absorption ability and the formation of N species and defects in the heat- and photoinduced N-doped TiO(2) catalyst. Under thermal treatment below 573 K in vacuum, no nitrogen dopant is removed from the doped samples but oxygen vacancies and Ti(3+) states are formed to enhance the optical absorption in the visible-light region, especially at wavelengths above 500 nm with increasing temperature. In the photoactivation processes of N-doped TiO(2), the DRS absorption and PL emission in the visible spectral region of 450-700 nm increase with prolonged irradiation time. The EPR results reveal that paramagnetic nitrogen species (N(s)·, oxygen vacancies with one electron (V(o)·), and Ti(3+) ions are produced with light irradiation and the intensity of N(s)· species is dependent on the excitation light wavelength and power. The combined characterization results confirm that the energy level of doped N species is localized above the valence band of TiO(2) corresponding to the main absorption band at 410 nm of N-doped TiO(2), but oxygen vacancies and Ti(3+) states as defects contribute to the visible-light absorption above 500 nm in the overall absorption of the doped samples. Thus, a detailed picture of the electronic structure of N-doped TiO(2) is proposed and discussed. On the other hand, the transfer of charge carriers between nitrogen species and defects is reversible on the catalyst surface. The presence of oxygen-vacancy-related defects leads to quenching of paramagnetic N(s)· species but they stabilize the active nitrogen species N(s)(-).

Photoinduced reactions between Pb3O4 and organic dyes in aqueous solution under visible light.

Pb(3)O(4) could react with organic dyes in aqueous solution under visible light irradiation, in which Pb(3)O(4) was transformed into Pb(3)(CO(3))(2)(OH)(2) along with oxidation of the organic dyes. Cu(2+) has considerable effect on the reaction. In the presence of Cu(2+), MO (20 ppm) and RhB (10(-5) mol L(-1)) were completely degraded under visible light within 6 and 20 min, respectively, while both Pb(3)O(4) and Cu(2+) keep almost stable during photodegradation. The mechanisms of the reactions with and without Cu(2+) ions were studied. The photochemical system of Pb(3)O(4) cooperating with Cu(2+) ions is probably used for the treatment of organic pollutants in water under visible light.

Genome-Wide Analysis of Alternative Splicing (AS) Mechanism Provides Insights into Salinity Adaptation in the Livers of Three Euryhaline Teleosts, including Scophthalmus maximus, Cynoglossus semilaevis and Oncorhynchus mykiss.

Salinity is an important environmental factor that directly affects the survival of aquatic organisms, including fish. However, the underlying molecular mechanism of salinity adaptation at post-transcriptional regulation levels is still poorly understood in fish. In the present study, 18 RNA-Seq datasets were utilized to investigate the potential roles of alternative splicing (AS) in response to different salinity environments in the livers of three euryhaline teleosts, including turbot (Scophthalmus maximus), tongue sole (Cynoglossus semilaevis) and steelhead trout (Oncorhynchus mykiss). A total of 10,826, 10,741 and 10,112 AS events were identified in the livers of the three species. The characteristics of these AS events were systematically investigated. Furthermore, a total of 940, 590 and 553 differentially alternative splicing (DAS) events were determined and characterized in the livers of turbot, tongue sole and steelhead trout, respectively, between low- and high-salinity environments. Functional enrichment analysis indicated that these DAS genes in the livers of three species were commonly enriched in some GO terms and KEGG pathways associated with RNA processing. The most common DAS genes work as RNA-binding proteins and play crucial roles in the regulation of RNA splicing. The study provides new insights into uncovering the molecular mechanisms of salinity adaptation in teleosts.

Dynamic transcriptome and LC-MS/MS analysis revealed the important roles of taurine and glutamine metabolism in response to environmental salinity changes in gills of rainbow trout (Oncorhynchus mykiss).

Recently, the frequent salinity fluctuation has become a growing threat to fishes. However, the dynamic patterns of gene expression in response to salinity changes remain largely unexplored. In the present study, 18 RNA-Seq datasets were generated from gills of rainbow trout at different salinities, including 0 ‰, 6 ‰, 12 ‰, 18 ‰, 24 ‰ and 30 ‰. Based on the strict thresholds, we have identified 63, 1411, 2096, 1031 and 1041 differentially expressed genes in gills of rainbow trout through pairwise comparisons. Additionally, weighted gene co-expression network analysis was performed to construct 18 independent modules with distinct expression patterns. Of them, green and tan modules were found to be tightly related to salinity changes, several hub genes of which are known as the important regulators in taurine and glutamine metabolism. To further investigate their potential roles in response to salinity changes, taurine, glutamine, and their metabolism-related glutamic acid and α-ketoglutaric acid were accurately quantitated using liquid chromatography-tandem mass spectrometry analysis. Results clearly showed that their concentrations were closely associated with salinity changes. These findings suggested that taurine and glutamine play important roles in response to salinity changes in gills of rainbow trout, providing new insights into the molecular mechanism of fishes in salinity adaptation.

Influence of Ego Depletion on Individual Forgiveness in Different Interpersonal Offense Situations.

Forgiveness, as an important content in the field of morality, means that the offended person overcomes the negative emotion, cognition, and behavior toward the offender and replaces it with positive emotion, cognition, and behavior. Based on the theory of the limitation of psychological resources, ego depletion (ED) will lead to the weakening of self-regulation function, thus making some immoral behaviors, which is not conducive to individual forgiveness. In order to explore the influence of ED on individual forgiveness in different interpersonal offense situations, this study used the Stroop task to manipulate the level of ED and used imaginary situations to distinguish offending situations. We found that the level of forgiveness in a serious offense situation was significantly lower than that in a mild offense situation, p < 0.001, partial η2 = 0.158. In different interpersonal offense situations, ED has different effects on forgiveness. In the severe offense situation, the forgiveness level of high-ED individuals was significantly lower than that of the low-ED individuals, p = 0.023, partial η2 = 0.144; in the mild offense situation, the forgiveness level of high-ED individuals was significantly higher than that of low-ED individuals, p = 0.029, partial η2 = 0.140. The results showed that different levels of ED have no consistent effect on forgiveness in different interpersonal offense situations; high ED hinders individual forgiveness in serious offense situations but can promote individual forgiveness in mild offense situations.

Effects of constant and diel cyclic temperatures on the liver and intestinal phospholipid fatty acid composition in rainbow trout Oncorhynchus mykiss during seawater acclimation.

BACKGROUND: Rainbow trout is an economically important fish in aquaculture and is a model species in environmental physiology. Despite earlier research on the seawater adaptability of rainbow trout at different temperature regimes, the influence on the liver and intestine in this species is still unknown. Two trials were conducted to investigate the effects of constant and diel cyclic temperatures on phospholipid fatty acid (PLFA) composition in the liver and intestine of rainbow trout during seawater acclimation. RESULTS: At the end of growth trial 1, fish at 9 and 12.5 °C showed significantly higher ratios of unsaturated to saturated (U/S) and unsaturation index (UI) than those at 16 °C in liver and intestine phospholipids. After day 1 of seawater acclimation, the U/S, UI, and average chain length (ACL) of liver and intestinal phospholipids in fish at 16 °C significantly increased. Two weeks after seawater acclimation, the liver and intestinal PLFA composition adapted to salinity changes. In trial 2, significantly higher U/S, UI, and ACL were found in intestinal phospholipids at 13 ± 2 °C. On the first day after seawater acclimation, UI and ACL in liver phospholipids significantly increased at 13 °C, while fish at 13 ± 2 °C showed significantly decreased U/S, UI, and ACL in the intestine. At the end of growth trial 2, liver PLFA compositions were stable, whereas intestinal PLFA at 13 and 13 ± 1 °C showed significantly decreased U/S, UI, and ACL. A two-way analysis of variance and principal component analysis revealed significant effects of different constant temperatures, seawater acclimation, and their interaction on the liver and intestinal phospholipids, a significant effect of diel cyclic temperature on intestinal phospholipids, and the effects of seawater acclimation and its interaction with diel cyclic temperature on liver phospholipids. CONCLUSION: Temperatures of 9 and 12.5 °C could elevate membrane fluidity and thickness in the liver and intestine of rainbow trout in freshwater, whereas no significant effects were found with diel temperature variations. After seawater acclimation, constant and diel cyclic temperatures significantly influenced the membrane fluidity and thickness of the liver and intestine. Compared with constant temperature, diel temperature variation (13 ± 2 °C) can enhance the adaptability of rainbow trout during seawater acclimation.

Growth, serum biochemical parameters, salinity tolerance and antioxidant enzyme activity of rainbow trout (Oncorhynchus mykiss) in response to dietary taurine levels.

This study evaluated the effect of dietary taurine levels on growth, serum biochemical parameters, salinity adaptability, and antioxidant activity of rainbow trout (Oncorhynchus mykiss). Four diets were formulated with taurine supplements at 0, 0.5, 1, and 2% w/v (abbreviated as T0, T0.5, T1, and T2, respectively). Rainbow trouts (initial weight of 80.09 ± 4.72 g) were stocked in tanks (180 L capacity), and were fed these diets for six weeks and subsequently underwent salinity acclimation. Physiological indicators were determined before salinity acclimation at 1, 4, 7, and 14 days afterwards. Results showed that there were no significant differences in growth performance (final mean weight ranged from 182.35 g to 198.48 g; percent weight gain was between 127.68% and 147.92%) of rainbow trout in freshwater stage, but dietary taurine supplement significantly increased serum-free taurine content. After entering seawater, the Na+-K+-ATPase activity of T2 group returned to its freshwater levels, and the serum cortisol content was significantly higher than T0 and T0.5 groups. At the end of this experiment, the liver superoxide dismutase activity in the T0 and T0.5 groups was significantly lower than in the T1 and T2 groups, and the liver catalase in the T0 group was the lowest whereas that in the T2 group was the highest. Muscle malondialdehyde content was the highest in the T0 group, and the lowest in the T2 group. Based on the results of this study, supplement of dietary taurine (0.5-2%) enhanced the salinity tolerance in rainbow trout, which increased with the higher taurine concentration.

Effects of different temperatures on seawater acclimation in rainbow trout Oncorhynchus mykiss: osmoregulation and branchial phospholipid fatty acid composition.

This study aimed to investigate the effects of different temperatures on seawater acclimation in rainbow trout (Oncorhynchus mykiss), in terms of growth performance, osmoregulatory capacity, and branchial phospholipid fatty acid (PLFA) composition. The fish (initial weight, 94.73 g) were reared at 9, 12.5, and 16 °C for 28 days, then acclimated to seawater, and subsequently reared for 14 days. Sampling points were on the last day in freshwater, and the 1st, 4th, 7th, and 14th days after the salinity reached 30. The results showed the final weight, percent weight gain, and specific growth rate of rainbow trout at 12.5 °C were significantly higher than those at 9 °C, while the thermal growth coefficient at 16 °C was significantly lower than that in other treatments. The branchial PLFA composition in rainbow trout changed more rapidly at 9 and 12.5 °C than at 16 °C. The branchial PLFA composition was significantly affected by temperature and salinity and their interaction. The polyunsaturated fatty acid content of phospholipids in the gill at 9 and 12.5 °C was significantly higher than those at 16 °C. Low temperature (9 °C) and seawater acclimation significantly increased the degree of unsaturation of membrane, enhancing membrane fluidity, which is related to Na+-K+ ATPase activity. Responses of plasma ion, Na+-K+ ATPase activity, and plasma glucose followed a similar pattern at different temperatures. Overall, the study suggests that 12.5 °C is the ideal temperature for seawater acclimation in rainbow trout.

Effects of seawater acclimation at constant and diel cyclic temperatures on growth, osmoregulation and branchial phospholipid fatty acid composition in rainbow trout Oncorhynchus mykiss.

The study investigated the effects of seawater acclimation at constant and diel temperatures on the growth, osmoregulation, and branchial phospholipid fatty acid (PLFA) composition in rainbow trout (Oncorhynchus mykiss). The fish (initial weight, 62.28 ± 0.41 g) were reared at a constant 13.0 °C (CT) or with a diel cycle of either 13.0 ± 1.0 °C (VT2) or 13.0 ± 2.0 °C (VT4) for 6 weeks, and subsequently subjected to seawater acclimation. Diel temperature variations (of up to 4 °C) did not affect the growth rate of rainbow trout maintained in freshwater, but alleviated the impairment on the growth after seawater challenge. Under all temperature conditions, rainbow trout were well prepared to seawater acclimation. The diel cyclic temperature resulted in fish with reduced fluctuations in plasma electrolyte levels, branchial Na+-K+ ATPase activity, and plasma osmolality. In freshwater, the sum of the monounsaturated fatty acids was significantly higher in the VT4 relative to CT and VT2 treatment. Conversely, the sum of polyunsaturated fatty acids was significantly lower in the VT4 fish. After seawater transfer, the branchial PLFA profiles of the fish significantly changed, but those in CT and VT2 did not recover afterwards (the degree of unsaturation was downregulated). The PLFA composition of fish in the VT4 treatment appeared to be steadier under seawater acclimation. This study suggests that a diel cyclic temperature (13.0 ± 2.0 °C) can alleviate the impairment of growth, enhance osmoregulation capability, and improve the stability of the branchial PLFA composition in rainbow trout after seawater acclimation.

Reversible Deposition of Lithium Particles Enabled by Ultraconformal and Stretchable Graphene Film for Lithium Metal Batteries.

Originating from inhomogeneous Li deposition and dissolution, the formation of dendritic and/or dead Li lies as a fundamental barrier to the practical implementation of Li metal anodes for high-energy Li-ion batteries. Here, an ultraconformal and stretchable solid-electrolyte interphase (SEI) composed of parallelly stacked few-layer defect-free graphene nanosheets, which can deform to remain ultraconformal during the expansion and shrinkage of micro-sized Li metal particles is reported. The shape-adaptive graphene protective skin is prepared via a facile mechanical method followed by Li stripping, which enables fast Li-ion diffusion, and inhibits Li dendrites and Li pulverization. The interlayer slips and wrinkles of the graphene film endow the robust protective skin with high stretchability. This work represents a unique strategy of building ultraconformal and stretchable 2D-materials-based protective skins on the surface of Li metal toward high-energy, long-life, and safe Li metal batteries.