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ABSTRACT A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the quantitative determination of phytohormones and betaines in algae. The results showed that phytohormones and betaines were separated with high efficiency on Hypersil Gold C18 and Cnwsil SCX columns. Mass spectrometric detection was performed using positive or negative electrospray ionization in selective reaction monitoring mode (SRM). Linearity of the method was good with correlation coefficients (r2) > 0.9951 in the range of 0.005-5 mg/L. The limits of detection were from 0.004 to 0.86 µg/L and the limits of quantification were in the range from 0.01 to 2.8 µg/L for the investigated phytohormones and betaines. The obtained recoveries varied between 61.33 and 90.39%, and the relative standard deviations were <15%. Using the developed methods, seven types of phytohormones and two types of betaines in Laminaria japonica, and seven types of phytohormones and one type of betaine in Pyropia haitanensis, which were collected in Xiangshan, Zhejiang Province, China, were determined. Thus, LC-MS/MS was demonstrated to be a powerful tool for the comprehensive analysis of phytohormones and betaines in algae, owing to its large dynamic range and excellent sensitivity. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The marine red alga Pyropia haitanensis (Protoflorideophyceae, Bangiaceae) has a nonvascular and multicellular structure and emerged earlier in evolution than other cultivatable red algae. It has been reported that lipid mediators from both the eicosanoid and octadecanoid pathways are involved in the innate immunity of other marine algae. But the defense strategies of P. haitanensis are not clearly understood. Here, we investigated the lipid defense of P. haitanensis elicited by agaro-oligosaccharides. The results indicate that the resistance of P. haitanensis was elicited and hydrogen peroxide was released by agaro-oligosaccharides. In P. haitanensis, C20 fatty acids are the essential fatty acids. Phospholipase A 2 was activated, and the free fatty acids decreased 3 h after treatment with agaro-oligosaccharides. Gas chromatography–mass spectrometry analyses revealed that the contents of volatile organic compounds increased after treatment for 3 h, which indicated that these free fatty acids were metabolized to volatile organic compounds. In conclusion, the lipid metabolic defense pathway of P. haitanensis was mainly via the C20 metabolism pathway. The C20 fatty acid was rapidly metabolized to volatile organic compounds, but not oxidized to oxylipins in response to agaro-oligosaccharides. [ABSTRACT FROM AUTHOR]

Changes in membrane lipid composition play multiple roles in plant adaptation and survival in the face of chilling and freezing damage. The ultra-performance liquid chromatography/quadrupole-TOF-MS (UPLC/Q-TOF-MS)-based approach was developed for investigating the lipid changes during cold exposure in Stephanodiscus sp. followed by multivariate statistical analysis including principal components analysis, partial least squares discriminant analysis and orthogonal projection on latent structure discriminant analysis for data classification and potential biomarkers selection. The analysis demonstrated dramatic lipid alterations take place in both extraplastidic and plastidic membranes. Thirty-eight lipid molecules were selected and identified as putative biomarkers, including chlorophyll a degradation products, triacylglycerol, phosphatidylcholine, phosphatidylglycerol, sulfo-quinovosyldiacylglycerol, monogalactosyldiacylglyceroll, lyso-phosphatidylglycerol, lyso-phosphatidylcholine, lyso-monogalactosyldiacylglycerol and lyso-sulfoquinovosyldiacylglycerol. These metabolites have been shown previously to function in energy storage, membrane stability and photosynthesis efficiency. This study is the first one using UPLC/Q-TOF-MS-based lipidomic profiling with multivariate statistical analysis to explore the lipidomic changes of microalgae in response to stress conditions, which promotes better understanding of their physiology and ecology. [ABSTRACT FROM AUTHOR]

A facile method based on high performance liquid chromatography coupled with electrospray ionization tandem triple quadrupole mass spectrometry (HPLC-ESI-QqQ-MS) has been established to investigate the production of the oxidized scytonemin by Nostoc commune Vauch in different environmental conditions. In optimized HPLC-ESI-QqQ-MS conditions, the oxidized scytonemin can be effectively detected in selected reaction monitoring (SRM) mode. After regression, high linearity of the calibration curve was achieved with a correlation coefficient ( r) at 0.99. The limit of detection and limit of quantification were 0.03 and 0.10 ng mL, respectively. The recovery of the oxidized scytonemin was at 76.90 %, and the relative standard deviations of inter- and intraday precisions were lower than 8.95 % ( n = 4). Subsequently, the production of the oxidized scytonemin from N. commune has been investigated in different culture conditions. High culture temperature, strong illumination intensity, and light-dark cycle (12:12 h) were found to be good for producing the oxidized scytonemin by N. commune. In short, the HPLC-QqQ-SRM-MS method is a powerful tool for comprehensive analysis of the oxidized scytonemin from N. commune, owing to its excellent selectivity and sensitivity. [ABSTRACT FROM AUTHOR]

Ultra Performance Liquid Chromatography-Electrospray ionization-Quadrupole-Time of Flight Mass Spectrometry (UPLC-ESI-Q-TOF-MS) is a powerful lipidomic tool. In this study, we developed a UPLC/Q-TOF-MS based method to investigate the lipid metabolomic changes in different growth phases of Nitzschia closterium f. minutissima. The data classification and biomarker selection were carried out by using multivariate statistical analysis, including principal components analysis (PCA), projection to latent structures with discriminant analysis (PLS-DA), and orthogonal projection to latent structures with discriminant analysis (OPLS-DA). We discovered that the intercellular lipid metabolites were significantly different among exponential, early stationary and late stationary phases. Thirty-one lipid molecules were selected and identified as putative biomarkers, including free fatty acid, Harderoporphyrin, phosphatidylglycerol, 1,2-diacyglycerl-3-O-4′-(N,N-trimethy)-homoserine, triacylglycerol, cholesterol, sulfoquinovosyldiacylglycerol, lyso-sulfoquinovosyldiacylglycerol, monogalactosyldiacylglycerol, digalactosyldiacylglycerol and lyso-digalactosyldiacylglycerol. These lipids have been shown previously to function in energy storage, membrane stability and photosynthesis efficiency during the growth of diatoms. Further analysis on the putative biomarkers demonstrated that nitrate starvation played critical role in the transition from exponential phase to stationary phase in N. closterium. This study is the first one to explore the lipidomic changes of microalgae in different growth phases, which promotes better understanding of their physiology and ecology. [ABSTRACT FROM AUTHOR]

Light irradiation plays an important role in the growth of microalgae and their nutrient composition. To elucidate the effect of different LED lights (red, orange, green, blue, purple, simulated sunlight, and white) on the main nutritional compositions of Isochrysis zhanjiangensis, the growth, fatty acid composition, soluble carbohydrate, and soluble protein contents were studied. The results show that I. zhanjiangensis grew the fastest under blue light (p = 0.044). In terms of fatty acid composition, the percentage of myristic acid (C14:0) decreased significantly (p = 0.021) under blue light and simulated sunlight, but the percentages of palmitic acid (C16:0) (p = 0.032) and stearic acid (C18:0) (p = 0.037) significantly increased. The percentage of docosahexaenoic acid (C22:6n-3) increased under orange light (p = 0.021), and the percentage of total unsaturated fatty acids increased under blue light (p = 0.008). The protein content significantly increased under simulated sunlight (p = 0.025), while the carbohydrate content did not vary much (p > 0.05) under different lights. These findings provide useful guidance for optimizing the cultivation conditions of I. zhanjiangensis to improve its nutritional value and yield. [ABSTRACT FROM AUTHOR]

The serum polar lipid metabolic changes for two common cage-cultured fishes, yellow coraker Pseudosciaena crocea and Japanese seabass Lateolabrax japonicus, after tropical storm attack have been studied by ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-qTOF-MS). The full scan mass spectrometry combined with principal component analysis (PCA) and orthogonal projections to latent structures discriminant analysis (OPLS-DA) indicated that yellow croaker underwent significant chemico-physiological changes during the recovery process, whereas Japanese seabass did not show such noticeable time-dependent consistent metabolites change patterns. Further identification of the metabolite biomarkers showed the increase of phosphatidylcholine with high unsaturated fatty acid and lysophospholipids, and the decrease of phosphatidylcholine with saturated fatty acids and plasmologens, which indicated the need of energy supplement and successive stressful inflammation. The increase of taurocholic acid and decrease of cortol could be regarded as the physiological alleviation measure during the recovery period. This is the first metabolomic study to tackle the fish physiological response for the complex environmental changes, and demonstrated that lipidomics is an effective analytical tool for predicting the stress resistance of fish to ultra uncontrolled environmental stress. [ABSTRACT FROM AUTHOR]

Abstract: The biomedical NiTi alloy was treated by micro-arc oxidation in an electrolytes containing sodium aluminate and sodium hypophosphite at 400V constant voltages for 30min. The MAO-treated NiTi has a porous microstructure on its surface and coatings consisting only of the γ-Al2O3 phase. The ceramic coating prepared by micro-arc oxidation is composed of Al, Ti, Ni, O, and P with the atomic concentration of 26.98%, 3.67%, 3.33%, 65.30% and 0.72%, respectively. The MAO-treated NiTi was soaked in a simulated body fluid (1.0SBF) to investigate the biomimetic deposition of apatite on the surface of Al2O3 coated NiTi alloy. It was found that Al2O3 coated NiTi alloy shows an excellent apatite-forming ability after soaking in a simulated body fluid (1.0SBF) for 14days, while no apatite-forming ability was observed on bared NiTi alloy even though soaking time is up to 28days. [Copyright &y& Elsevier]

Abstract: The photosynthetic glycerolipids composition of algae is crucial for structural and physiological aspects. In this work, a comprehensive characterization of the photosynthetic glycerolipids of the diatom Stephanodiscus sp. was carried out by ultra performance liquid chromatography–electrospray ionization-quadrupole-time of flight mass spectrometry (UPLC–ESI-Q-TOF MS). By use of the MSE data collection mode, the Q-TOF instrument offered a very viable alternative to triple quadrupoles for precursor ion scanning of photosynthetic glycerolipids and had the advantage of high efficiency, selectivity, sensitivity and mass accuracy. Characteristic fragment ions were utilized to identify the structures and acyl compositions of photosynthetic glycerolipids. Comparing the abundance of fragment ions, it was possible to determine the position of the sn-glycerol-bound fatty acyl chains. As a result, four classes of photosynthetic glycerolipid in the extract of Stephanodiscus sp. were unambiguously identified, including 16 monogalactosyldiacylglycerols (MGDGs), 9 digalactosyldiacylglycerols (DGDGs), 23 sulfoquinovosyldiacylglycerols (SQDGs) and 8 phosphatidylglycerols (PGs). As far as our knowledge, this is the first report on global identification of photosynthetic glycerolipids, including lipid classes, fatty acyl composition within lipids and the location of fatty acids in lipids (sn-1 vs. sn-2), in the extract of marine microalgae by UPLC–ESI-Q-TOF MS directly. [Copyright &y& Elsevier]

Chrysotila is a genus of coccolithophores. Together with Emiliania, it is one of the representative genera in the Haptophyta which have been extensively studied. They are photosynthetic unicellular marine algae sharing the common characteristic of the production of CaCO3 platelets (coccoliths) on the surface of their cells and are crucial contributors to global biogeochemical cycles. Here, we report the genome assembly of Chrysotila roscoffensis. The assembled genome size was ~636 Mb distributed across 769 scaffolds with N50 of 1.63 Mb, and maximum contig length of ~2.6 Mb. Repetitive elements accounted for approximately 59% of the genome. A total of 23,341 genes were predicted from C. roscoffensis genome. The divergence time between C. roscoffensis and Emiliania huxleyi was estimated to be around 537.6 Mya. Gene families related to cytoskeleton, cellular motility and morphology, and ion transport were expanded. The genome of C. roscoffensis will provide a foundation for understanding the genetic and phenotypic diversification and calcification mechanisms of coccolithophores. [ABSTRACT FROM AUTHOR]

Precise structural identification of photosynthetic polar glycerolipids in microalga Tetraselmis chuii has been established using Ultra Performance Liquid Chromatography-Electrospray ionization-Quadrupole-Time of Flight Mass Spectrometry (UPLC-ESI-Q-TOF-MS) by direct analysis of the total lipids extract. The mass spectrometry was performed in reflective time-of-flight using electron spraying ionization in both positive and negative modes. The structural determination was based on the characteristic product ions yielded by different glycerolipids under ESI-MS/MS mode, and confirmed the molecular species by the carboxylate anions produced by glycerolipids in the negative mode. As a result, more than 40 lipid molecular species, including 11 monogalactosyldiacylglycerols (MGDG), 7 digalactosyldiacylglycerols (DGDG), 16 sulfoquinovosyldiacylglycerols (SQDG), and 9 phosphatidylglycerols (PG), were detected in Tetraselmis chuii, which had never been identified before in this microalga. Furthermore, some intact lipid molecules with hydroxylated fatty acids that could not be detected by the traditional GC-MS method were found this time, providing novel information for the photosynthetic lipidome of Tetraselmis chuii. Comparative studies on fatty acids at the sn-2 position showed that SQDG and MGDG are dominantly biosynthesized through the prokaryotic pathway, PG is a typically mixed biosynthetic pathway, while DGDG is somewhat peculiar with C14:0 and C16:0 at its sn-2 position. This method could provide a full structural profile of intact photosynthetic lipid molecular species, which may be applied to study the physiological and ecological functions of lipid by monitoring their individual changes. [ABSTRACT FROM AUTHOR]

Clarifying the biosynthetic pathway of the long-chain polyunsaturated fatty acids (LC-PUFA) of Sinonovacula constricta is essential for utilizing its LC-PUFA resources. Methyl-end (or "ωx") desaturases are the rate-limiting enzymes in LC-PUFA biosynthesis, catalyzing the conversion of oleic acid to linoleic acid (LA) or LA to α-linolenic acid. However, their presence in S. constricta remains uncertain. Herein, we identified two ωx desaturase-like genes within the S. constricta genome, both located on the ninth chromosome possibly due to genome duplication. These genes exhibited nearly identical sequences, differing by only one amino acid, and each encodes a 354-residue peptide with typical ωx desaturase characteristics. Phylogenetic analysis grouped these putative ωx desaturases with similar enzymes from other invertebrates. However, when heterologously expressed in yeast, they exhibited no detectable desaturation activity. This suggests either non-functionality in yeast or extremely subtle desaturation abilities. Additionally, both genes displayed the highest expression in the inhalant siphon rather than in digestive tissues and exhibited relatively high expression throughout the development stages of S. constricta, except in zygotes. These findings suggest potential in vivo functional roles for these ωx desaturases in S. constricta. Collectively, these results significantly enrich our understanding of the repertoire of LC-PUFA biosynthetic enzymes in this important bivalve species. [ABSTRACT FROM AUTHOR]

• Simulation and modeling on laser polishing in melting and transition regimes. • Mechanism of surface topography evolution in laser polishing is revealed. • Contributions of surface forces and material removal in laser polishing are analyzed. • Thermocapillary force affected by surface-active component results in a bulge structure on the polished surface. • Surface roughness prediction is tried through the established model with a maximum error of 14.9%. Previous studies on the mechanism of laser polishing were limited to the melting regime, this paper proposed a numerical model for the melting and transition regimes of laser polishing, which coupled heat transfer, fluid flow, and material vaporization. Based on the model, the evolution of the temperature and velocity fields of the molten pool in laser polishing was presented. And the mechanism of surface topography evolution was revealed from the perspective of surface forces (capillary force, thermocapillary force, and recoil pressure), fluid velocity, and material removal. Furthermore, the corresponding relationships between surface forces, fluid velocity, and surface topography were determined. The contributions of surface forces and vaporization front velocity in laser polishing were investigated, and the reason for the formation of the bulge structure and the influence of laser power on it were analyzed. And the velocity direction change points which have a great influence on the surface evolution were found, and the method to determine the positions of these points was proposed. Besides, the surface roughness prediction after laser polishing was tried through the numerical model, and the maximum error between the predicted results and the experimental results is 14.9%. Therefore, this model can be used to optimize process parameters. [ABSTRACT FROM AUTHOR]

Bull. Corrigendum to "Spatiotemporal variation, seasonal variation, and potential risks of sedimentary heavy metals in a new artificial lagoon in eastern China, 2014-2019" [Mar. Pollut. [Extracted from the article]

Rational design of the photocatalysis is of vital importance to mediate many important photocatalytic reactions such as water splitting, pollutant degradation and CO 2 reduction. In this work, we employed a solvent evaporation induced self-assembly method to prepare a novel S-scheme heterojunction composite by combining sulfur-doped porous graphite carbon nitride (S-pCN) with tungsten oxide (WO 2.72) semiconductors which manifest effective interface contact and excellent photocatalytic performance. During the formation of the heterojunction, the electron defect state of surface oxygen vacancies on WO 2.72 can be filled by the lone pair electrons of sulfur and nitrogen elements on S-pCN. Through the adjustment of composite ratios, appropriate surface oxygen vacancies were retained on WO 2.72 , thereby fascinate the migration of electrons and the generation of free radicals. The internal electric field (IEF) and the band bending effects accelerate the transfer of photogenerated charges at the interface, thereby promotes the recombination of useless photogenerated carriers, retains photogenerated electron (e−) and hole (h+) with the higher redox potentials, improves the separation and utilization efficiency of the photogenerated carriers and enhances the photocatalytic activity of the system. This work provides new insights for the design of a novel S-scheme heterojunction photocatalyst for highly efficient simultaneous photocatalytic degradation and hydrogen evolution activity. Through the regulation of sulfur atoms on the surface oxygen vacancies (OVs) of S-pCN/WO 2.72 and the synergistic effect of the internal electric field (IEF) of the S-scheme heterojunction, the separation and utilization efficiency of the photogenerated carriers and the photocatalytic activity of the S-scheme heterojunction photocatalyst are significantly improved. ga1 • A novel S-pCN/WO 2.72 S-scheme heterojunction was fabricated by a simple solvent evaporation induced self-assembly method. • Sulfur atoms effectively regulate the content of surface oxygen vacancies in S-pCN/WO 2.72. • Appropriate surface oxygen vacancies cooperated with high CB and deep VB potentials promote the photocatalytic activity. [ABSTRACT FROM AUTHOR]

Understanding the metabolic effects of fatty acids on fish intestine is critical to the substitution of fish oil with vegetable oils in aquaculture. In this study, the effects of eicosapentaenoic acid (EPA) and palmitic acid (PA) on fish intestine were evaluated in vitro and in vivo. As the first step for in vitro study, an intestinal cell line (SPIF) was established from silver pomfret (Pampus argenteus). Thereafter, the effects of EPA and PA on cell viability, prostaglandin E2 (PGE2) production, and the expression of genes related to heat shock response, inflammation, extracellular matrix (ECM) formation and degradation were examined in SPIF cells. Finally, these metabolic effects of EPA and PA on the intestine were examined in zebrafish (Danio rerio) larvae. Results showed that all tested fatty acids (PA, oleic acid, linoleic acid, α-linolenic acid, arachidonic acid, and docosahexaenoic acid) except EPA reduced SPIF viability to distinct degrees at the same concentrations. PA decreased SPIF viability accompanied by an increase in PGE2 level. Meanwhile, PA increased the expression of genes related to heat shock response (grp78 , grp94 , hsp70 , and hsp90) and inflammation (nf-κb , il-1β , and cox2). Furthermore, PA reduced the expression of collagen type I (col1a1a and col1a1b) and extracellular matrix (ECM) degradation-related gene mmp2 , while up-regulating timp2 mRNA expression. In vivo , PA also increased hsp70 , il-1β , and cox2 mRNA levels and limited the expression of collagen type I in the larval zebrafish intestine. Interestingly, the combination of EPA and PA partially recovered the PA-induced changes in cell viability, PGE2 production, and mRNA expression in vitro and in vivo. These results suggest that PA may result in heat shock and inflammatory responses, as well as alter ECM formation and degradation in fish intestine, while EPA could at least partially mitigate these negative effects caused by PA. • An intestinal cell line from silver pomfret (SPIF) was developed as a study model. • Except for EPA, PA, OA, LA, ALA, ARA and DHA decreased SPIF viability to distinct degrees. • PA induced heat shock and inflammatory responses, and affected repair processes in fish intestine. • EPA mitigated PA-induced negative effects on fish intestine. [ABSTRACT FROM AUTHOR]

As a key feature of a part or assembly, surface structure can effectively improve the surface properties of the workpiece. Laser remelting is a promising method for surface structure formation, but sensitive to ambient gases. Therefore, this paper presents a numerical model that incorporates the contribution of air atmosphere on surface bulge structure formation. For this, the model couples a concentration field to reflect the oxygen mass transfer in the melt pool and introduces a semi-empirical function to describe the contribution of oxygen to the surface tension. Based on the model, it discusses the surface structure formation mechanisms, the heat-mass transfer characteristics, the melt flow patterns, and the surface force transient evolutions. The results reveal that the action of air atmosphere on melt flow manifests itself through two mechanisms, namely, the enhancement of inward thermocapillary forces and the introduction of outward solutocapillary forces. Furthermore, combined with the laser remelting experiments on 304 stainless steels, the established model is validated concerning the surface bulge structure size, the melt pool depth, and the oxygen distribution. [ABSTRACT FROM AUTHOR]

Due to rapid urbanization and industrialization, heavy metal (HM) pollution in coastal areas of the East China Sea (ECS) has attracted extensive attention. This article attempts to review recent studies on the temporal and spatial distributions, ecological risks, and possible sources of HMs in typical bays and estuaries of ECS. The levels of HMs are closely related to local economic development and local characteristics. The anthropogenic activities and the particle size of sediments are important factors affecting the distribution of HMs. During the late 1970s to the 1990s, HMs levels in the Yangtze Estuary (YRE) sediments showed an upward tendency due to the increased emissions. However, HMs levels in the early 2000s were lower than that in the late 1970s to the mid-1990s. Cd caused serious pollution and brought potential ecological risks in the Yangtze Estuary, Hangzhou Bay (HZB), Sanmen Bay (SMB), and Quanzhou Bay (QZB). In Fujian province of China, the Quanzhou Bay was heavily polluted by HMs and high contents of HMs were found in biota. Among different species, molluscs in the coastal areas of ECS have the highest levels of HMs exceeding safety limits. • Heavy metal (HM) pollution in coastal areas of the East China Sea has been reviewed. • Anthropogenic activities and particle size of sediments are the main factors affecting HMs distribution. • HM pollution in some bays of Fujian province is worse than in other regions. • Inter-annual changes of HMs in some bays have not been obvious in recent years. • Molluscs have high levels of HMs. [ABSTRACT FROM AUTHOR]

The application of microalgal diets in aquaculture is gaining more and more attention with the increasing demand of aquaculture. Literature reports of diet microalgae in rearing bivalve species have mainly focused on nutrient uptake of shellfish, and there is a lack of complete overview of nutritional composition and efficient microalgae cultivation methods for the purpose to improve shellfish production. This paper reviews the effects of microalgal composition for the rearing of bivalve mollusks, and analyzes the economic cost of microalgae culture for bivalve mollusk feeding. Artificial or natural feeds have not been proven to be effective substitutes for live microalgae in rearing bivalve mollusks. In our view, the effects of feeding diet microalgae to bivalve shellfish can vary depending on their different life stages. Mixing suitable microalgae diets can play a beneficial role in the growth of the bivalve mollusks. The content of fatty acids, sterols, and carotenoids in the microalgae are important factors affecting the nutritional value for the shellfish. Biofilm attached culture of some microalgae can increase the cell density of the algae. Studying the nutritional requirements of bivalve mollusks at different periods in their lifecycles, formulating the proper mixed feed according to the composition of lipids and sterols in the microalgae, and efficient microalgae culture systems, may improve the nutritional value and reduce the production costs of shellfish. • The effects of different microalgae on nutrition of bivalve mollusks were different. • Mixing algal diets can play a beneficial role in the growth of bivalve mollusks. • Efficient algae culture systems may reduce the cost of rearing bivalve mollusks. [ABSTRACT FROM AUTHOR]

The spatiotemporal variation, seasonal variation, and potential ecological risk of eight heavy metals (HMs) in the Meishan Bay (MSB) a new artificial lagoon –from 2014 to 2019 were investigated. The levels of As, Cu, Pb, Cr, Ni, and Zn in winter were higher than in other seasons, Hg in winter and summer were higher than in other seasons, while Cd in summer and spring (wet season) were the highest. The seasonal distribution of HMs was mainly affected by particle size, anthropogenic sources, rainfall, and water characteristics. The concentrations of these HMs showed a general downward trend, while Hg showed an upward trend from2014 to 2019. Higher levels of HMs were found outside the North dyke and some sluice gates. The sources of Cd, Zn, and Pb could be attributed to ship discharges and traffic exhaust, while pesticides and fertilizers were the main sources of Hg. Among all these HMs, Cd and Hg caused moderate pollution in the MSB. • The levels of most heavy metals in winter were higher than in other seasons in sediments of Meishan Bay. • Concentrations of 7 heavy metals showed a downward trend from 2014 to 2019, while Hg showed an upward trend. • Cd concentrations in wet seasons were higher than in dry seasons. [ABSTRACT FROM AUTHOR]

The aim of this study is to determine the spatial distribution, potential sources, and ecological risks of 8 heavy metals (Zn, Cu, Cr, Ni, As, Cd, Hg, and Pb) in Meishan Bay, Zhejiang coast, China. Surface water (n = 31), bottom water (n = 31), and surface sediments (n = 31) were collected. Water physicochemical properties and sediment resuspension were important factors affecting spatial distributions of heavy metals. The spatial distributions of Cr, Ni, Pb, As, Cu, and Zn were consistent with the clay distribution. Atmospheric deposition was the main source of Cd and Pb, mainly from industrial and transportation exhausts, while Zn was mainly from ship transportation. Agriculture pesticides and sewage wastewater were considered as the main sources for Hg. The geo-accumulation index results indicated that there was limited pollution of Cu, Zn, Cr, Pb, and As, and mild to moderate pollution of Cd and Hg. The potential ecological risk assessment suggested a high ecological risk of Hg in Meishan Bay. • The properties of water and sediment are important factors affecting spatial distribution of metals. • Atmospheric deposition is the main source of Cd and Pb. • Agriculture pesticides and sewage are considered as the main sources for Hg. • Hg poses the largest ecological risk in Meishan Bay. [ABSTRACT FROM AUTHOR]

As a burgeoning surface finishing process, laser polishing (LP) introduces some undesired surface structures, limiting access to better laser-polished surfaces. Considering this, the paper proposes a novel hybrid processing method, ultrasonic vibration-assisted laser polishing (UVLP). Horizontal ultrasonic vibration, perpendicular to the laser scanning direction, is imposed on the workpiece, which promotes homogenized melt distribution in the melting pool, contributing to the polished surface flatness. Bulge, a typical surface structure formed in LP, serves as the verification vehicle for the effect of ultrasonic vibration here. In this investigation, comparative experiments were performed on 304 stainless steels to demonstrate the regulation phenomenon of ultrasonic vibration on the bulge formation. Subsequently, the corresponding numerical model was developed to explore the acting mechanisms of ultrasound from the thermal and hydrodynamic fields. The model also optimized the coupling method of volume expansion to better capture the change in melting pool volume during the polishing process, especially during the cooling phase. The results indicated that the forced melt oscillations are the dominant mechanism to uniformize the metallic materials distribution, regulating the bulge formed along the polished track. The degraded melt flow pattern, a simple harmonic oscillation, reached similar results. Furthermore, the developed model verified its effectiveness through surface flatness, melting pool dimensions, and microhardness. • A new hybrid processing method, ultrasonic vibration-assisted laser polishing (UVLP), is proposed. • The regulation phenomenon of ultrasonic vibration on the bulge formation is visualized. • The acting mechanisms of ultrasonic vibrations in UVLP are analyzed theoretically and experimentally. • A UVLP model is developed and its effectiveness is verified. • The coupling method for volume expansion is optimized. [ABSTRACT FROM AUTHOR]

The razor clam Sinonovacula constricta, a commercially important and nutritionally valuable bivalve species, has been found to display notable responses to different light spectra. While previous research has highlighted the influence of light spectra on the growth, feeding rate, and various physiological characteristics of S. constricta, its impact on the biochemical composition of this species remains unclear. Herein, we investigated the proximate, fatty acid, and amino acid compositions of S. constricta cultured under various light spectra, including white, violet, blue, cyan, green, yellow, red, and darkness. Furthermore, we explored the potential molecular mechanisms underlying these observations through transcriptomic analysis. The results indicate that the light spectrum has a significant impact on the growth, biochemical composition, and gene expression of juvenile S. constricta. Specifically, culturing S. constricta under the yellow light led to improved growth rate (1.09 ± 0.03%/day), higher levels of carbohydrate (26.27% ± 0.49%), crude lipid (11.99% ± 0.23%), energy contents (14,611.34 ± 1,067.01 kJ/kg), and essential amino acids (15.22 ± 0.01 g/kg), as well as increased proportions of polyunsaturated fatty acids (12.38 ± 0.31 µg/mg). These findings suggest that yellow light may play a crucial role in enhancing the nutritional quality of S. constricta. Moreover, the transcriptomic analysis revealed that the yellow light treatment upregulated pathways related to fatty acid biosynthesis, glycine, serine, and threonine metabolism and fatty acid metabolism. This indicates that yellow light may influence nutrient metabolism regulation in S. constricta, potentially leading to the observed changes in biochemical composition. Overall, our study recommends cultivating juvenile S. constricta under yellow light to optimize their growth and nutritional value. Further research could delve deeper into the molecular mechanisms underlying the effects of different light spectra on S. constricta to enhance our understanding of how light influences aquaculture practices and the nutritional quality of seafood products. [ABSTRACT FROM AUTHOR]

. [ABSTRACT FROM AUTHOR]

Background: Botryococcus braunii is known for its high hydrocarbon content, thus making it a strong candidate feedstock for biofuel production. Previous study has revealed that a high cobalt concentration can promote hydrocarbon synthesis and it has little effect on growth of B. braunii cells. However, mechanisms beyond the cobalt enrichment remain unknown. This study seeks to explore the physiological and transcriptional response and the metabolic pathways involved in cobalt-induced hydrocarbon synthesis in algae cells. Results: Growth curves were similar at either normal or high cobalt concentration (4.5 mg/L), suggesting the absence of obvious deleterious effects on growth introduced by cobalt. Photosynthesis indicators (decline in Fv/Fm ratio and chlorophyll content) and reactive oxygen species parameters revealed an increase in physiological stress in the high cobalt concentration. Moreover, cobalt enrichment treatment resulted in higher crude hydrocarbon content (51.3% on day 8) compared with the control (43.4% on day 8) throughout the experiment (with 18.2% improvement finally). Through the de novo assembly and functional annotation of the B. braunii race A SAG 807-1 transcriptome, we retrieved 196,276 non-redundant unigenes with an average length of 1086 bp. Of the assembled unigenes, 89,654 (45.7%), 42,209 (21.5%), and 32,318 (16.5%) were found to be associated with at least one KOG, GO, or KEGG ortholog function. In the early treatment (day 2), the most strongly upregulated genes were those involved in the fatty acid biosynthesis and metabolism and oxidative phosphorylation, whereas the most downregulated genes were those involved in carbohydrate metabolism and photosynthesis. Genes that produce terpenoid liquid hydrocarbons were also well identified and annotated, and 21 (or 29.2%) were differentially expressed along the cobalt treatment. Conclusions: Botryococcus braunii SAG 807-1 can tolerate high cobalt concentration and benefit from hydrocarbon accumulation. The time-course expression profiles for fatty acid biosynthesis, metabolism, and TAG assembly were obtained through different approaches but had equally satisfactory results with the redirection of free long-chain fatty acid and VLCFA away from TAG assembly and oxidation. These molecules served as precursors and backbone supply for the fatty acid-derived hydrocarbon accumulation. These findings provide a foundation for exploiting the regulation mechanisms in B. braunii race A for improved photosynthetic production of hydrocarbons. [ABSTRACT FROM AUTHOR]

Ultrasonic vibration-assisted powder feeding (UVPF) technology enables precise point-by-point delivery of powder in additive manufacturing. However, it is prone to compaction and blockage by prolonged vibration. In this paper, an UVPF system combining spiral conveying and ultrasonic vibration was designed and evaluated. The study presents an improved three-dimensional numerical model based on the discrete element method and investigates the evolution of the particle velocity field. The findings demonstrated that there are differences in the dynamic behavior of particles in different locations. The mechanisms of vibration frequency and impact stress are described in terms of powder flow pattern and friction resistance. However, the vibration parameters have no impact on the powder's falling initial velocity. Cohesion between the particles is the key parameter to determine the compaction. During ultrasonic vibration, the cohesion between particles located further away from the tube wall increases, leading to a compaction effect. [Display omitted] • Ultrasonic friction reduction changes the powder flow from funnel to mass flow. • The impact stress on the tube wall during vibration is analyzed. • The vibration parameters have no impact on the velocity of the powder falling. • Powder located further away from the tube wall is more easily compacted. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms of lipid transport and metabolism in fish is crucial to enhance dietary lipid utilization. Here, fatty acid translocase (CD36) gene was characterized in silver pomfret (Pampus argenteus). The open reading frame of silver pomfret cd36 gene was 1395 bp, encoding 464 amino acids. The silver pomfret CD36 protein contained typical transmembrane regions and N-glycosylation modification sites, and was localized to the cytomembrane. The cd36 gene was ubiquitously expressed in all tested tissues, with the highest expression observed in brain tissue. In vivo , both fasting and short-term high-fat feeding could increase cd36 expression in intestinal tissue. In vitro , cd36 expression was induced by palmitic acid, oleic acid, linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid treatment in intestinal tissue. Furthermore, dual-luciferase reporter assay results indicated that peroxisome proliferator-activated receptor gamma (PPARγ) could enhance cd36 promoter activity, and the co-expression of cd36 and pparγ was observed in EPA-incubated intestine, suggesting that EPA may regulate the expression of cd36 via PPARγ to maintain the homeostasis of intestinal lipid metabolism in silver pomfret. These results highlighted the crucial role of CD36 in silver pomfret, and suggested that the cd36 expression may be regulated by PPARγ. This study could contribute to a greater understanding of lipid metabolism and the development of effective strategies for nutrient requirements in fish. [Display omitted] • CD36 was identified and characterized in silver pomfret. • Silver pomfret CD36 possessed typical transmembrane receptor characteristics. • Silver pomfret cd36 expression was regulated by nutritional status and LCFAs. • EPA might regulate Silver pomfret cd36 expression via PPARγ pathway. [ABSTRACT FROM AUTHOR]

Summary: Fucoxanthin, a natural carotenoid that has substantial pharmaceutical value due to its anticancer, antioxidant, antiobesity, and antidiabetic properties, is biosynthesized from glyceraldehyde‐3‐phosphate (G3P) via a series of enzymatic reactions. However, our understanding of the transcriptional mechanisms involved in fucoxanthin biosynthesis remains limited.Using reverse genetics, the med8 mutant was identified based on its phenotype of reduced fucoxanthin content, and the biological functions of MED8 in fucoxanthin synthesis were characterized using approaches such as gene expression, protein subcellular localization, protein–protein interaction and chromatin immunoprecipitation assay.Gene‐editing mutants of MED8 exhibited decreased fucoxanthin content as well as reduced expression levels of six key genes involved in fucoxanthin synthesis, namely DXS, PSY1, ZDS‐like, CRTISO5, ZEP1, and ZEP3, when compared to the wild‐type (WT) strain. Furthermore, we showed that MED8 interacts with HSF3, and genetic analysis revealed their shared involvement in the genetic pathway governing fucoxanthin synthesis. Additionally, HSF3 was required for MED8 association with the promoters of the six fucoxanthin synthesis genes.In conclusion, MED8 and HSF3 are involved in fucoxanthin synthesis by modulating the expression of the fucoxanthin synthesis genes. Our results increase the understanding of the molecular regulation mechanisms underlying fucoxanthin synthesis in the diatom P. tricornutum. [ABSTRACT FROM AUTHOR]

The primary cause of tool failure in rough cutting is the severe tool-chip friction brought on by chip adhesion and abrasive wear. To address the problem, the influence of combinations of micro-textures and AlCrN coating, and the sequence of their combinations on tool surface characteristics and cutting performance in dry cutting AISI 304 were investigated. The results of wettability and indentation tests indicate the micro-textures reduce the contact angle of the tool surface (by 13.26%) and increase the contact area between micro-textures and the coating, resulting in a better adhesive strength (grade HF3) for the first micro-textured and then AlCrN-coated tool (TCT). The results of cutting experiments demonstrate that the TCT's cutting performance is improved as the cutting speed increases between 50 and 141 m/min, with the highest reductions in main cutting force and radial cutting force reaching 27% and 38% at 141 m/min. The TCT's micro-textures reduce tool-chip contact area, while the intact AlCrN coating film decreases chip adhesion and improves the wear resistance of cutting tools. This study is expected to be applied to further improve the tool performance under dry and rough cutting conditions. [ABSTRACT FROM AUTHOR]

The large-scale farming of Nannochloropsis spp. has long been subject to high temperature. Though salicylic acid is widely used to enhance the high temperature resistance of higher plants, related research in microalgae is still in its infancy. In this study, Nannochloropsis oceanica cells at 25 °C were transferred to high temperature (35 °C) for 96 h, during which period salicylic acid with various concentrations (0, 15, 25, 35, and 50 mg L−1) were added into high temperature groups. The results indicated that high temperature could heavily inhibit the growth of N. oceanica, and result in various physiological and biochemical changes. The addition of exogenous salicylic acid at moderate concentration distinctly alleviated the inhibition of heat stress on N. oceanica. Moreover, further analysis indicated that exogenous salicylic acid could significantly increase the contents of soluble sugars, soluble proteins, total unsaturated fatty acids, and catalase activity, but result in the decrease of the nitrate reductase activity, the malondialdehyde content, and fatty acid profile. Our results also demonstrated that salicylic acid at a concentration of 15 mg L−1 received the best growth performance of N. oceanica under 35 °C. This study investigates the thermal protection effect of salicylic acid on N. oceanica under high temperature, and can provide valuable information for the large-scale production of microalgae. [ABSTRACT FROM AUTHOR]

Laser shock peening (LSP) was conducted on H13 steel prior to plasma nitriding (PN). The optical microscopy (OP), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), microhardness tester and ball-on-disk wear tester were employed to investigate the microstructure and properties of plasma nitrided H13 steel coupled with LSP processing. The results show that a large number of dislocations, as well as dislocation cells and nanocrystals composed of high-density dislocations, are observed in H13 steel after LSP treatment. Compared with the PN sample, the diffraction peak intensities of the Fe 3 N phase in the LSP + PN sample are slightly enhanced and the diffraction peaks shift to the right as a whole. Compared to the PN sample, the LSP + PN sample exhibits significant improvements in various aspects. Specifically, the white bright layer and diffusion layer of the LSP + PN sample increased by approximately 25 % and 119.4 %, respectively. Additionally, the thickness of the effective hardened layer increased by around 50 %, and the microhardness increased by approximately 31.3 %. The LSP + PN sample has the better wear resistance than that of the PN sample, with the friction coefficient, wear scar width, wear volume, and wear rate reduced by 11.1 %, 8.4 %, 7.9 %, and 7.3 %, respectively. Through parallel experiments, the experimental error is controlled within 2 %. • The intensity of the Fe 3 N phase in the LSP+PN sample are slightly enhanced and shifted to the right. • LSP can significantly improve the efficiency of plasma nitriding, and obtain thicker nitriding layers. • The LSP+PN sample has the better microhardness and wear resistance than that of the PN sample. • A large number of dislocation cells and nanocrystals composed of high-density dislocations are observed. [ABSTRACT FROM AUTHOR]

The razor clam Sinonovacula constricta is the first marine mollusk demonstrated to possess the complete long-chain polyunsaturated fatty acids (LC-PUFA) biosynthetic pathway. This study explored the impact of different microalgae on growth, Fad and Elovl expressions, and fatty acid (FA) profiles in juvenile S. constricta. Results revealed that juveniles fed with Isochrysis galbana (rich in DHA) or Chaetoceros calcitrans (rich in EPA) consistently exhibited higher growth than those fed Chlorella sp. (rich in LA and ALA), underscoring the importance of dietary LC-PUFA in S. constricta's development. Expression of most Fad and Elovl in C. calcitrans and I. galbana-fed juveniles were initially up-regulated, then down-regulated, suggesting LC-PUFA demand for faster growth. Although Chlorella sp.-fed juveniles exhibited decreased mRNA levels for most genes, levels were notably higher lately compared to those fed C. calcitrans or I. galbana, hinting at potential LC-PUFA biosynthesis induction. FA profiles in S. constricta generally mirrored those in ingested microalgae, implying direct FA accumulation from diets. Some microalgal FA were absent in farmed S. constricta, while others emerged, indicating S. constricta's ability to selectively accumulate and synthesize FA. This study enhances the understanding of dietary FA metabolism in S. constricta, valuable for selecting appropriate microalgae in its farming practices. [ABSTRACT FROM AUTHOR]

• An improved model capable of analyzing the effects of ambient gas on laser polishing is proposed. • Mass transfer, solutocapillary force, and chemical reaction are added to the model. • Convection is the main mass transfer mechanism in the molten pool, not diffusion. • The solutocapillary force always acts in the opposite direction to the melt flows. • The dissolved oxygen enhances the thermocapillary force driving the melt to flow inward. Laser polishing, as an effective surface finishing process, is significantly affected by ambient gas. Previous studies on the contribution of ambient gas to laser polishing mostly focused on experiments, but rarely on numerical simulations. Given this, this paper proposes an improved model capable of analyzing the effects of ambient gas on the laser-polished surface's morphology evolution mechanisms, by expanding an existing laser polishing model with the influences of mass transfer, solutocapillary forces, and chemical reactions. Argon and air were used as ambient gasses for comparison. Through this model, the surface morphology evolution of laser polishing in air was compared with that in argon in terms of the velocity field, temperature field, concentration field, melt surface velocity, molten pool surface profile, and surface forces. The respective contributions of chemical reaction heat, oxygen mass flux, mass transfer, and surface forces were also presented. Furthermore, the numerical model was verified on 304 stainless steel from the perspectives of polished surface roughness, molten pool depth, and oxygen element distribution. [Display omitted] [ABSTRACT FROM AUTHOR]

It is of great significance for bivalve aquaculture to promote the growth through nutritional strategy. Phosphatidic acid (PA) is a potential growth-promoting nutraceutical that targets for mammalian target of rapamycin (mTOR) in vertebrates, but its role in invertebrates remains largely unknown. Here, the effects of PA on mTOR and metabolic pathways in bivalve mollusk Sinonovacula constricta were determined by intramuscular injection with di-18 : 2 PA and di-16 : 0 PA. PA (both di-18 : 2 and di-16 : 0 PA) was found to increase the glycogen concentration in the muscle of S. constricta. Di-16 : 0 PA decreased the triglyceride concentration from 0.143 ± 0.04 mmol/g protein to 0.040 ± 0.018 mmol/g protein. The concentration of Asp, Glu, Ala, Cys, Val, Met, Ile, Leu, Phe, Arg, and Pro was reduced by di-18 : 2 PA or/and di-16 : 0 PA. PA increased the mRNA level of mTOR and the phosphorylation levels of eIF4E binding protein 1 and p70S6 kinase 1. Furthermore, PA decreased the protein level of microtubule-associated protein 1 light chain 3 Ⅱ/Ⅰ and the mRNA level of AMP-activated protein kinase. The mRNA expressions of two key enzymes of glycolysis (pyruvate kinase and glucokinase) were also upregulated by both PA, while the mRNA level of glucose transporter 1 was increased by di-18 : 2 PA. Di-16 : 0 PA decreased the mRNA level of phosphoenolpyruvate carboxykinase. The mRNA levels of sterol responsive element binding protein, fatty acid synthase, and acetyl-CoA carboxylase were increased by both PA. The mRNA level of stearoyl-CoA desaturase was increased by di-18 : 2 PA. Both PA species increased the mRNA levels of key enzymes involved in tricarboxylic acid cycle (citrate synthase and NADP-isocltrate debydrogenase). Our results indicated that PA activated mTOR signaling pathway, subsequently leading to the increase of anabolism and the inhibition of catabolism in S. constricta. [ABSTRACT FROM AUTHOR]

In addition to being important primary productive forces in marine ecosystems, diatoms are also rich in bioactive substances such as triacylglycerol and fucoxanthin. However, little is known about the transcriptional mechanisms underlying the biosynthesis of these substances. In this study, we found that the heat shock transcription factor PtHSF1 positively regulated the synthesis of triacylglycerol and fucoxanthin in Phaeodactylum tricornutum. Overexpression of PtHSF1 could increase the contents of triacylglycerol and fucoxanthin and upregulate key enzyme genes involved in the triacylglycerol and fucoxanthin biosynthesis pathways. On the other hand, gene silencing of PtHSF1 reduced the contents of triacylglycerol and fucoxanthin and the expression of the key enzyme genes involved in the triacylglycerol and fucoxanthin biosynthesis pathways. Further biochemical analysis revealed that PtHSF1 upregulated glycerol-2-phosphate acyltransferase 3 (GPAT3) and 1-deoxy- d -xylulose 5-phosphate synthase (DXS) by directly binding to their promoters, while genetic analysis demonstrated that PtHSF1 acted upstream of GPAT3 and DXS to regulate triacylglycerol and fucoxanthin synthesis. Therefore, in addition to elucidating the regulation mechanisms underlying PtHSF1-mediated triacylglycerol and fucoxanthin synthesis, this study also provided a candidate target for metabolic engineering of triacylglycerol and fucoxanthin in P. tricornutum. [ABSTRACT FROM AUTHOR]

Ghrelin, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) are potent hormones mediating food intake according to the nutritional status in fish. However, limited information is available on these genes and their expression in response to nutrition in silver pomfret (Pampus argenteus). A comparison analysis revealed that ghrelin and GLP-1 were relatively conserved in marine fish. PYYa and PYYb shared a low identity and were clustered to different PYY branches. Ghrelin, pyya, and pyyb mRNAs were highly expressed in the brain, while glp-1 was highly expressed in the gills and liver. The ghrelin mRNA expression was relatively high an hour post-feeding and decreased after 3 to 72 h of fasting. The glp-1 mRNA expression was increased after 6 to 24 h of fasting. The pyya mRNA expression was increased after 72 h of fasting, while the pyyb expression remained stable during fasting. The diet with 14% lipid promoted the expressions of glp-1, pyya, and pyyb, but inhibited the ghrelin expression. The ghrelin expression in the intestine was increased after palmitic acid, oleic acid (OA), linoleic acid (LA), α-linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) incubation. OA decreased the expression of glp-1 and increased the expression of pyya. The expression of pyyb was downregulated by LA, DHA, and EPA. These results suggest the importance of ghrelin, glp-1, and pyy in coordinating food intake in response to fasting, dietary lipid concentration, and fatty acids in silver pomfret. [ABSTRACT FROM AUTHOR]

In recent years, the role of lectins in the feed selection of bivalve has become hot research topic. Manila clam Ruditapes philippinarum is a species of marine bivalve with important economic value. A new C-type lectin (Rpcl) from the clam was obtained and its potential role in feeding and feed selection was studied. Rpcl cDNA was 929 bp in length and had 720 bp of open reading frame. Rpcl encoded 235 amino acids, comprising a carbohydrate recognition domain (CRD) as well as an N-terminal signal peptide. Rpcl contained a conserved CRD disulfide bond including five cysteine residues (Cys125, Cys142, Cys213, Cys219, and Cys237) and the QPN motif (GLN204-PRO205-ASN206). Phylogenetic analysis revealed that the amino acid sequence of Rpcl was closely related to that of Vpclec-1 from R. philippinarum and C-type lectin from Mercenaria. The qPCR analysis indicated that Rpcl expression was observed in all examined tissues and was the highest in gills followed by in the hepatopancreas, and to a lesser extent in the mantle and lip. The in vitro agglutination experiments showed that, the purified Rpcl protein could selectively agglutinate with different microalgae. The strongest agglutinating effect with Chlorella sp. was observed, followed by Karlodinium veneficum and Chaetoceros debilis Cleve. No agglutination with Prorocentrum minimum was observed. In the feeding experiment, compared with that of the starvation group, Rpcl expression in the lip and gill of the clam fed with C. debilis and K. veneficum showed a significant upward trend with the change of time. In addition, it was found that the changes in the expression of the Rpcl gene in the gill and lip, the main feeding tissues, were consistent with the slope of the decrease in the number of algal cells in the water body. In summary, the structure of a new C-type lectin (Rpcl) was reported in this study and its correlation with the feeding and feed selection in R. philippinarum was confirmed. [ABSTRACT FROM AUTHOR]

• Porous NiMnGa alloys with large size pores are prepared by one-step sintering method. • Porous alloys with different porosities have similar phase transformation behavior. • The composite is prepared by infiltrating epoxy resin into the porous alloy. • The composite exhibits a similar phase transformation behavior to the porous alloy. • Mechanical property of the composite is effectively improved by synergistic effect. This article investigated microstructure, phase transformation and mechanical property of porous NiMnGa alloy and its composite with epoxy resin. The porous NiMnGa alloys with large pores and different porosity exhibited a similar martensitic transformation behavior but with reduced martensitic transformation temperature as compared to that of the original powder. The porous alloys exhibited low mechanical strength and ductility due to the existence of large size pores. After compositing with epoxy resin, the mechanical strength and ductility of the porous alloy had been apparently enhanced due to the synergistic effect between the polymer and porous alloy. In addition, the composite demonstrated a martensitic transformation behavior similar with that of the porous alloy, indicating that the constraint effect of polymer matrix on the phase transformation of the porous alloy could be neglected. The combination of porous NiMnGa alloys with continuous structure and polymer could provide a promising way to make NiMnGa/polymer composites with better performance than the composites consisting of NiMnGa particles and polymer. [ABSTRACT FROM AUTHOR]

The razor clam Sinonovacula constricta is known for its richness in long-chain polyunsaturated fatty acids (LC-PUFA, C ≥ 20). Previously, we demonstrated that it possesses a complete LC-PUFA biosynthetic pathway. However, the mechanisms by which it senses the LC-PUFA pool to regulate their biosynthesis remain unclear. Here, we presented the LC-PUFA sensor UBXD8 as a critical molecule in this intriguing process. The S. constricta UBXD8 (Sc UBXD8) shared all characteristic features of its mammalian counterpart and exhibited high mRNA levels in digestive tissues, suggesting its functional role in this bivalve species. By purification of Sc UBXD8 protein in vitro , we discovered its ability to sense unsaturated fatty acids (UFA, C ≥ 14) but not saturated ones, as evidenced by polymerization detection. Furthermore, the intensity of Sc UBXD8 polymerization increased progressively with longer acyl chain lengths, greater unsaturation degrees, and higher UFA concentrations. Exceptionally, for those located at the same node in LC-PUFA biosynthetic pathway, Sc UBXD8 displayed a stronger sensitivity to n-6 UFA compared to n-3 UFA. These results suggested a critical role for Sc UBXD8 in balancing fatty acids composition and ratio of n-6/n-3 UFA in S. constricta. Moreover, the UAS domain was confirmed essential for Sc UBXD8 polymerization. Through knockdown of Sc Ubxd8 gene in vivo , there were significant shifts in expression patterns of genes related to LC-PUFA biosynthesis, concurrently influencing fatty acids compositions. These results suggested that Sc UBXD8 likely plays a regulatory role in LC-PUFA biosynthesis, possibly through the INSIG-SREBP pathway. Collectively, this study proposed that S. constricta might maintain LC-PUFA homeostasis through UBXD8 to regulate their biosynthesis. • Characteristics of S. constricta UBXD8 (Sc UBXD8) were evolutionarily conserved. • Sc UBXD8 displayed ability to sense unsaturated fatty acids but not saturated ones. • Knocking down Sc Ubxd8 significantly disrupted LC-PUFA synthesis in S. constricta. • Knocking down Sc Ubxd8 significantly altered fatty composition in S. constricta. • S. constricta might sense LC-PUFA pool through UBXD8 to maintain homeostasis. [ABSTRACT FROM AUTHOR]

The nanoporous Ni-based solid solution electrode inspired by mimicking the components of natural Gibeon meteorites fallen from the sky brings favourable electrochemical and mechanical performances for the oxygen evolution reaction in alkaline medium. This study provide a promising low-cost and environment-friendly approach to prepare nanoporous architectures based on non-precious metal solid solutions for high-efficiency water electrolysis towards large-scale utilization of clean hydrogen energy. • Nanoporous Ni-based solid solution by Mimicking Natural Gibeon Meteorites. • An metal oxyhydroxide layer of approximately 9 nm thickness for the OER. • Robust electrochemical and mechanical performance for the OER in alkaline medium. Transforming the intermittent solar and wind energies into green hydrogen energy by water electrolysis is deemed to be a promising approach to substitute traditional fossil energies. However, the scarcity of precious IrO 2 /RuO 2 -based metal oxides for oxygen evolution reaction hinders the large-scale utilization. Here, based on the nanoscale Kirkendall effect, we fabricate nanoporous γ-Ni based solid solution with the simulated FeCoNi surface compositions of Gibeon meteorites by a facile microwave sintering method. A metal (oxy)hydroxide layer with a thickness of approximately 9 nm was formed on the surface of as-prepared electrode after aging, achieving an overpotential of only 254 mV at 10 mA cm−2 and a low Tafel slope of 37.0 mV dec−1. The electrode exhibits outstanding long-term stability in a wide range of current densities without compromising the electrocatalytic activity, which is attributed to the 3D-interconnected nanoporous structure, synergistic effect of different species, high conductivity and excellent wettability. The fabrication of nanoporous non-precious solid solution architectures which mimic naturally-formed materials provides a feasible strategy for the design of high-performance electrocatalysts towards clean energy applications. [ABSTRACT FROM AUTHOR]

Abstract: Yttrium oxide (Y2O3) transparent ceramics samples have been successfully fabricated by microwave sintering processing at relatively low temperatures. In comparison with the vacuum sintering processing, Y2O3 transparent ceramics can be obtained by microwave sintering at lower sintering temperature and shorter sintering time, and they possess higher transmittances and mechanical properties. The technologies of low-temperature microwave sintering and the relationships of the microstructures and properties of the specified samples have been investigated in detail. We have found out that the low-temperature microwave sintering technique has its obvious advantages over the conventional methods in manufacturing yttrium oxide transparent ceramics. [Copyright &y& Elsevier]