Jiesheng Liu

In order to explore the potential of graphene (G) in removal of hazardous chemicals in waste water, chemically reduced graphene oxide was employed as the adsorbent and the adsorption characteristics of graphene toward acrylonitrile (AN), p-toluenesulfonic acid (p-TA), 1-naphthalenesulfonic acid (1-NA) and methyl blue (MB) were evaluated under laboratory conditions. The results showed that the organic chemicals with larger molecule size and more benzene rings possessed a higher adsorption speed and a higher maximum adsorption capacity on G. The maximum adsorption capacities of p-TA, 1-NA and MB on G are ∼1.43 g/g G, ∼1.46 g/g G and ∼1.52 g/g G at 30 °C, respectively, which are the highest values of p-TA, 1-NA or MB adsorption on different kinds of today's nanomaterials. Under the maximum adsorption capacity, the absorption quantity of MB on G was dependent on the initial concentration of MB, and higher temperature could facilitate the adsorption process. The G efficiency remains almost constant during the first five cycles of the adsorption–desorption process. In addition, the fluorescence spectra implied that the adsorption of MB on G was a π–π stacking adsorption process. In conclusion, the G could serve as a promising adsorbent for the removal of chemicals containing benzene rings in waste water.

To obtain fast growing oil-rich microalgal strains has been urgently demanded for microalgal biofuel. Malic enzyme (ME), which is involved in pyruvate metabolism and carbon fixation, was first characterized in microalgae here. Overexpression of Phaeodactylum tricornutum ME (PtME) significantly enhanced the expression of PtME and its enzymatic activity in transgenic P. tricornutum. The total lipid content in transgenic cells markedly increased by 2.5-fold and reached a record 57.8% of dry cell weight with a similar growth rate to wild type, thus keeping a high biomass. The neutral lipid content was further increased by 31% under nitrogen-deprivation treatment, still 66% higher than that of wild type. Transgenic microalgae cells exhibited obvious morphological changes, as the cells were shorter and thicker and contained larger oil bodies. Immuno-electron microscopy targeted PtME to the mitochondrion. This study markedly increased the oil content in microalgae, suggesting a new route for developing ideal microalgal strains for industrial biodiesel production.

Microalgae have been emerging as an important source for the production of bioactive compounds. Marine diatoms can store high amounts of lipid and grow quite quickly. However, the genetic and biochemical characteristics of fatty acid biosynthesis in diatoms remain unclear. Glycerophospholipids are integral as structural and functional components of cellular membranes, as well as precursors of various lipid mediators. In addition, diacylglycerol acyltransferase (DGAT) is a key enzyme that catalyzes the last step of triacylglyceride (TAG) biosynthesis. However, a comprehensive sequence-structure and functional analysis of DGAT in diatoms is lacking. In this study, an isoform of diacylglycerol acyltransferase type 2 of the marine diatom Phaeodactylum tricornutum was characterized. Surprisingly, DGAT2 overexpression in P. tricornutum stimulated more oil bodies, and the neutral lipid content increased by 35%. The fatty acid composition showed a significant increase in the proportion of polyunsaturated fatty acids; in particular, EPA was increased by 76.2%. Moreover, the growth rate of transgenic microalgae remained similar, thereby maintaining a high biomass. Our results suggest that increased DGAT2 expression could alter fatty acid profile in the diatom, and the results thus represent a valuable strategy for polyunsaturated fatty acid production by genetic manipulation.

Oleaginous microalgae have great prospects in the fields of feed, nutrition, biofuel, etc. However, biomass and lipid productivity in microalgae remain a major economic and technological bottleneck. Here we present a novel regulatory target, glucose-6-phosphate dehydrogenase (G6PD) from the pentose phosphate pathway (PPP), in boosting microalgal lipid accumulation. G6PD, involved in the formation of NADPH demanded in fatty acid biosynthesis as reducing power, was characterized in oleaginous microalga Phaeodactylum tricornutum. In G6PD overexpressing microalgae, transcript abundance of G6PD increased by 4.4-fold, and G6PD enzyme activity increased by more than 3.1-fold with enhanced NADPH production. Consequently, the lipid content increased by 2.7-fold and reached up to 55.7% of dry weight, while cell growth was not apparently affected. The fatty acid composition exhibited significant changes, including a remarkable increase in monounsaturated fatty acids C16:1 and C18:1 concomitant with a decrease in polyunsaturated fatty acids C20:5 and C22:6. G6PD was localized to the chloroplast and its overexpression stimulated an increase in the number and size of oil bodies. Proteomic and metabolomic analyzes revealed that G6PD play a key role in regulating pentose phosphate pathway and subsequently upregulating NADPH consuming pathways such as fatty acid synthesis, thus eventually leading to lipid accumulation. Our findings show the critical role of G6PD in microalgal lipid accumulation by enhancing NADPH supply and demonstrate that G6PD is a promising target for metabolic engineering.

Microalgae have emerged as a potential feedstock for biofuels and bioactive components. However, lack of microalgal strains with promising triacylglycerol (TAG) content and desirable fatty acid composition have hindered its commercial feasibility. Attempts on lipid overproduction by metabolic engineering remain largely challenging in microalgae.In this study, a microalgal 1-acyl-sn-glycerol-3-phosphate acyltransferase designated AGPAT1 was identified in the model diatom Phaeodactylum tricornutum. AGPAT1 contained four conserved acyltransferase motifs I-IV. Subcellular localization prediction and thereafter immuno-electron microscopy revealed the localization of AGPAT1 to plastid membranes. AGPAT1 overexpression significantly altered the primary metabolism, with increased total lipid content but decreased content of total carbohydrates and soluble proteins. Intriguingly, AGPAT1 overexpression coordinated the expression of other key genes such as DGAT2 and GPAT involved in TAG synthesis, and consequently increased TAG content by 1.81-fold with a significant increase in polyunsaturated fatty acids, particularly EPA and DHA. Moreover, besides increased lipid droplets in the cytosol, ultrastructural observation showed a number of TAG-rich plastoglobuli formed in plastids.The results suggested that AGPAT1 overexpression could elevate TAG biosynthesis and, moreover, revealed the occurrence of plastidial TAG synthesis in the diatom. Overall, our data provide a new insight into microalgal lipid metabolism and candidate target for metabolic engineering.

Oleaginous microalgae have received a considerable attention as potential biofuel feedstock. However, lack of industry-suitable strain with lipid rich biomass limits its commercial applications. Targeted engineering of lipogenic pathways represents a promising strategy to enhance the efficacy of microalgal oil production. In this study, a type 2 diacylglycerol acyltransferase (DGAT), a rate-limiting enzyme in triacylglycerol (TAG) biosynthesis, was identified and overexpressed in heterokont oleaginous microalga Nannochloropsis oceanica for the first time. Overexpression of DGAT2 in Nannochloropsis increased the relative transcript abundance by 3.48-fold in engineered microalgae cells. TAG biosynthesis was subsequently accelerated by DGAT2 overexpression and neutral lipid content was significantly elevated by 69% in engineered microalgae. The fatty acid profile determined by GC-MS revealed that fatty acid composition was altered in engineered microalgae. Saturated fatty acids and polyunsaturated fatty acids were found to be increased whereas monounsaturated fatty acids content decreased. Furthermore, DGAT2 overexpression did not show negative impact on algal growth parameters. The present investigation showed that the identified DGAT2 would be a potential candidate for enhancing TAG biosynthesis and might facilitate the development of promising oleaginous strains with industrial potential.

The marine diatom Phaeodactylum tricornutum is attracting considerable interest as a candidate for biofuel production due to its fast growth and high lipid content. Nitrogen deficiency can increase the lipid content in certain microalgae species, including P. tricornutum. However, the molecular basis of such changes remains unclear without analyzing metabolism at the proteomic level. We attempted to systematically analyze protein expression level changes of P. tricornutum upon N deprivation. We observed translational level changes that could overall redirect the metabolic network from carbon flux towards lipid accumulation. N deprivation led to an increase in the expression of genes involved in nitrogen assimilation and fatty acid biosynthesis and a concomitant decrease in photosynthesis and lipid catabolism enzymes. These molecular level changes are consistent with the observed physiological changes, e.g., in photosynthesis rate and saturated lipid content. Our results provide information at the proteomic level of the key enzymes involved in carbon flux towards lipid accumulation in P. tricornutum and suggest candidates for genetic manipulation in microalgae breeding for biodiesel production.

The marine diatom, Phaeodactylum tricornutum, has become a model for studying lipid metabolism and its triacylglycerol (TAG) synthesis pathway makes it an ideal target for metabolic engineering to improve lipid productivity. However, the genetic background and metabolic networks of fatty acid biosynthesis in diatoms are not well understood. Glycerol-3-phosphate acyltransferase (GPAT) is the critical enzyme that catalyzes the first step of TAG formation. So far, characterization of GPAT in marine microalgae has not been reported, especially at the level of comprehensive sequence-structure and functional analysis.A GPAT was cloned from P. tricornutum and overexpressed in P. tricornutum. Volumes of oil bodies were produced and the neutral lipid content was increased by twofold determined by Nile red fluorescence staining. Fatty acid composition was analyzed by GC-MS, which showed significantly higher proportion of unsaturated fatty acids compared to wild type.These results suggested that the identified GPAT could upregulate TAG biosynthesis in P. tricornutum. Moreover, this study offers insight into the lipid metabolism of diatoms and supports the role of microalgal strains for biofuels production.

Commercialization of algal lipids and biofuels is still impractical owing to the unavailability of lipogenic strains and lack of economically viable oil extraction strategies. Because lipogenesis is governed by multiple factors, success in generating industrial-suitable algal strains using conventional strategies has been limited. We report the discovery of a novel bZIP1 transcription factor, NobZIP1, whose overexpression results in a remarkable elevation of lipid accumulation and lipid secretion in a model microalga Nannochloropsis oceanica, without impairing other physiological properties. Chromatin immunoprecipitation-quantitative PCR analysis revealed that the key genes up- and down-regulated by NobZIP1 are involved in lipogenesis and cell wall polymer synthesis, respectively, which, in turn, induce lipid overproduction and secretion. Among these regulated genes, UDP-glucose dehydrogenase was shown to alter cell wall composition, thus also boosting lipid secretion. In summary, these results offer a comprehensive strategy for concurrent lipid overproduction and secretion, strongly increasing the commercial potential of microalgae.

Microalgae are ideal raw materials for biodiesel and bioactive compounds. Glycerol-3-phosphate is formed from dihydroxyacetone phosphate (DHAP) through the glycolytic pathway catalyzed by glycerol-3-phosphate dehydrogenase (GPDH). GPDH was characterized in the marine diatom Phaeodactylum tricornutum. In the GPDH-overexpressing P. tricornutum cells, the glycerol concentration per cell in the transformed diatom increased by 6.8-fold compared with the wild type, indicating that the overexpression of GPDH promoted the conversion of DHAP to glycerol-3-phosphate. There was a 60% increase in neutral lipid content, reaching 39.7% of dry cell weight in transgenic cells in the stationary phase, despite a 20% decrease in cell concentration. Fatty acid profiling showed that the levels of 16- and 18-carbon monounsaturated fatty acids significantly increased. GPDH had a significant impact on numerous metabolic processes in diatom cells, including the biosynthesis of glycerol and neutral lipids. These findings are instructive for the metabolic engineering of microalgae for biofuel production.

Microalgae are important primary producers in the marine ecosystem and excellent sources of lipids and other bioactive compounds. The marine diatom Phaeodactylum tricornutum accumulates eicosapentaenoic acid (EPA, 20:5n-3) as its major component of fatty acids. To improve the EPA production, delta 5 desaturase, which plays a role in EPA biosynthetic pathway, was characterized in P. tricornutum. An annotated delta 5 desaturase PtD5b gene was cloned and overexpressed in P. tricornutum. The transgene was integrated into the genome demonstrated by Southern blot, and the overexpression of PtD5b was verified by qPCR and Western blot analysis. Fatty acid composition exhibited a significant increase in the unsaturated fatty acids. Monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) showed an increase of 75% and 64%, respectively. In particular, EPA showed an increase of 58% in engineered microalgae. Meanwhile, neutral lipid content showed an increase up to 65% in engineered microalgae. More importantly, engineered cells showed a similar growth rate with the wild type, thus keeping high biomass productivity. This work provides an effective way to improve the production of microalgal value-added bioproducts by metabolic engineering.

Abstract Oleaginous microalgae hold great promises for biofuel production. However, commercialization of microalgal biofuels remains impracticable due to the lack of suitable industrial strains with high growth rate and lipid productivity. Engineering of metabolic pathways is a potential strategy for the improvement of microalgal strains for the production of lipids and also value‐added products in microalgae. Malonyl CoA‐acyl carrier protein transacylase (MCAT) has been reported to be involved in fatty acid biosynthesis. Here, we identified a putative MCAT in the oleaginous marine microalga Nannochloropsis oceanica . NoMCAT overexpressing N. oceanica showed a higher growth rate and photosynthetic efficiency. The neutral lipid content of engineered lines showed a significant increase by up to 31% compared to wild type. Gas chromatography–mass spectrometry analysis revealed that NoMCAT overexpression significantly altered the fatty acid composition. The composition of eicosapentaenoic acid (C20:5), which is a polyunsaturated fatty acid necessary for animal nutrition, increased by 8%. These results demonstrate the role of MCAT in enhancing fatty acid biosynthesis and growth in microalgae, and also provide an insight into metabolic engineering of microalgae with high industrial potential.

To meet the national demand for energy conservation and emission reduction, a shape-stable CaCl2·6H2O /silica aerogel composite phase change material (CPCM) for building energy storage was successfully developed. The CPCM was formed by using modified CaCl2·6H2O composed of CaCl2·6H2O (main PCM) and SrCl2·6H2O (nucleating agent) as PCM, and silica aerogel as carrier via physical blending method. The structure and properties of the CPCM were investigated by various techniques. The results showed that compositing of modified CaCl2·6H2O with silica aerogel could significantly reduce the thermal conductivity, effectively prevent leakage as well as lessen supercooling. The obtained CPCM with 75 wt% modified CaCl2·6H2O had suitable phase transition temperature (27.0 °C) with high latent heat (110.9 J·g−1), acceptable supercooling degree (1.6 °C), low thermal conductivity (0.1954 W/(m·K)) as well as excellent thermal reliability. The results obtained make the CPCM in this work promising for use in building thermal insulation materials.

The promotion of green and sustainable development is prompting more and more researchers to investigate eco-friendly cementitious composites. Nevertheless, harmful gas emissions from the burning of large amounts of waste rice straw fibers have caused unavoidable environmental pollution. Experiments were carried out to evaluate the properties of alkali-activated rice straw fiber-modified cement composites at different doses, including water retention, mechanical strength, porosity, hydration, and anti-permeability. Freeze-thaw cycle test and sulfate corrosion test were also conducted. Besides, SEM and FT-IR tests were adopted to reveal the properties of the modified specimens. The results showed that the incorporation of alkali-activated rice straw fibers affected the properties of cement composites. Specifically, the properties of the modified cement specimens were significantly improved with the appropriate amount of rice straw fibers admixture, while the reserve effect was observed with excessive amount. These results help to relieve environmental pollution caused by rice straw fibers, and contribute to theoretical studies on the application of straw fibers in cement-based materials.

Summary Phosphorus is an important macronutrient. To understand the molecular and cellular responses to phosphorus stress better, transcriptome profiling in combination with biochemical investigations was conducted in the model diatom P haeodactylum tricornutum . Out of 10 402 predicted genes, 2491 and 405 genes were significantly upregulated or downregulated respectively. Unsurprisingly, genes associated with phosphate uptake were upregulated, such as the phosphate transporters and alkaline phosphatases. Genes encoding stress‐shock proteins were accordingly upregulated, including genes associated with stress‐responsive proteins, signal transduction and secondary metabolism. Additionally, genes related to protein translation, carbon fixation, glycolysis and the citric acid cycle were also upregulated. Genes associated with gene transcription were downregulated, thereby resulting in the upregulation of translation to compensate for the limited supply of messenger RNA . The downregulation of genes related to β ‐oxidation could contribute to the accumulation of fatty acids. Accordingly, triacylglycerols, which are important for energy storage, were determined to increase by 1.65‐fold. Intracellular membranes, other than chloroplast membranes, tended to be dispersed; this finding was in accordance with the increased transcription of a total of 11 genes encoding putative phospholipases. Taken together, this work revealed the coordination of multiple metabolic pathways and certain key genes in the adaptation of P . tricornutum to phosphorus stress.

Diatoms are important primary producers in the marine ecosystem. Currently it is difficult to genetically transform diatoms due to the technical limitations of existing methods. The promoter/terminator of the nitrate reductase gene of the model diatom Phaeodactylum tricornutum was cloned and used to drive chloramphenicol acetyltransferase (CAT) reporter gene expression. The construct was transferred by electroporation into P. tricornutum grown in medium lacking silicon. CAT expression was induced in transformed diatoms in the presence of nitrate, enabling growth in selective medium, and was repressed when ammonium was the only nitrogen source. Expression of CAT transcript and protein were demonstrated by RT-PCR and Western blot analysis, respectively. Our study is the first to report a successful genetic transformation of diatom by electroporation in an economical and efficient manner and provides a tightly regulated inducible gene expression system for diatom.

Microalgae have been an emerging biofuel resource; however, the germplasm improvement has been slow due to the lack of molecular tools. Pyruvate dehydrogenase kinase (PDK) deactivates the pyruvate dehydrogenase complex (PDC) which catalyzes the oxidative decarboxylation of pyruvate. Acetyl-CoA production via PDC is important in plant tissues that are active in fatty acid synthesis.A 1261-bp cDNA of a putative PDK gene (PtPDK) was cloned from a diatom Phaeodactylum tricornutum, and PtPDK antisense knockdown transgenic diatoms were generated. Both PtPDK transcript abundance and enzyme activity were reduced significantly due to antisense knockdown of PtPDK. Neutral lipid content of transgenic diatom cells increased up to 82% as determined by Nile red staining, and fatty acid composition was not altered. Transgenic cells showed slightly lower growth rate but similar cell size with the wild type, hence retaining similar biomass productivity.This work first obtained a successful engineered diatom regulating a key gene involved in lipid metabolism. Our findings also provide powerful indications in enhancing microalgal lipid production by metabolic engineering for biofuel industry.

In this study, a form-stable lauric acid/expanded perlite (LA/EP) composite was prepared by absorbing paraffin into porous networks of expanded perlite. The form-stable composite was characterized by using Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM) techniques, durability and leakage test. Leakage test results showed that optimum and maximum mass fraction of LA contained in the composite without leakage is 70 wt.%. The FT-IR results revealed that there were physical interactions between the expanded perlite and the lauric acid. In addition, SEM images showed that LA can be quite evenly dispersed in the porous skeleton of EP. The melting temperature and latent heat of the form-stable EP/PA composite containing 70 wt.% lauric acid were determined as 43.2 °C and 105.58 J/g, presenting its suitable phase transition temperature, sufficient latent heat, good thermal stability for application as composite phase change materials (PCMs). The durability test showed that the leakage problems of PCMs composite can be greatly prevented because of the interaction between the expanded perlite and the LA. All the results suggested that the form-stable EP/PA composite has great potential in building applications for thermal energy storage.

Plastids are ideal subcellular hosts for the expression of transgenes and have been successfully used for the production of different biopolymers, therapeutic proteins and industrial enzymes. Phaeodactylum tricornutum is a widely used aquatic feed species. In this study, we focused on developing a high-efficiency plastid expression system for P. tricornutum. In the plastid transformation vector, the site selected for integration was the transcriptionally active intergenic region present between the trnI and trnA genes, located in the IR (inverted repeat) regions of the plastid genome. Initially, a CAT reporter gene (encoding chloramphenicol acetyltransferase) was integrated at this site in the plastid genome. The expression of CAT in the transformed microalgae conferred resistance to the antibiotic chloramphenicol, which enabled growth in the selection media. Overall, the plastid transformation efficiency was found to be approximately one transplastomic colony per 1,000 microalgae cells. Subsequently, a heterologous gene expression cassette for high-level expression of the target gene was created and cloned between the homologous recombination elements. A TA cloning strategy based on the designed XcmI-XcmI sites could conveniently clone the heterologous gene. An eGFP (green fluorescent protein) reporter gene was used to test the expression level in the plastid system. The relatively high-level expression of eGFP without codon optimisation in stably transformed microalgae was determined to account for 0.12 % of the total soluble protein. Thus, this study presents the first and convenient plastid gene expression system for diatoms and represents an interesting tool to study diatom plastids.

The role of diatoms as a source of bioactive compounds has been recently explored.Diatom cells store a high amount of fatty acids, especially certain polyunsaturated fatty acids (PUFAs).However, many aspects of diatom metabolism and the production of PUFAs remain unclear.This review describes a number of technical strategies, such as modulation of environmental factors (temperature, light, chemical composition of culture medium) and culture methods, to influence the content of PUFAs in diatoms.Genetic engineering, a newly emerging field, also plays an important role in controlling the synthesis of fatty acids in marine microalgae.Several key points in the biosynthetic pathway of PUFAs in diatoms as well as recent progresses are also a critical part and are summarized here.

Phosphorus (P) is an essential macronutrient for the survival of marine phytoplankton. In the present study, phytoplankton response to phosphorus limitation was studied by proteomic profiling in diatom Phaeodactylum tricornutum in both cellular and molecular levels. A total of 42 non-redundant proteins were identified, among which 8 proteins were found to be upregulated and 34 proteins were downregulated. The results also showed that the proteins associated with inorganic phosphate uptake were downregulated, whereas the proteins involved in organic phosphorus uptake such as alkaline phosphatase were upregulated. The proteins involved in metabolic responses such as protein degradation, lipid accumulation and photorespiration were upregulated whereas energy metabolism, photosynthesis, amino acid and nucleic acid metabolism tend to be downregulated. Overall our results showed the changes in protein levels of P. tricornutum during phosphorus stress. This study preludes for understanding the role of phosphorous in marine biogeochemical cycles and phytoplankton response to phosphorous scarcity in ocean. It also provides insight into the succession of phytoplankton community, providing scientific basis for elucidating the mechanism of algal blooms.

Metabolic engineering has emerged as a potential strategy for improving microalgal lipid content through targeted changes to lipid metabolic networks. However, the intricate nature of lipogenesis has impeded metabolic engineering. Therefore, it is very important to identify the crucial metabolic nodes and develop strategies to exploit multiple genes for transgenesis. In an attempt to unravel the microalgal triacylglycerol (TAG) pathway, we overexpressed two key lipogenic genes, glycerol-3-phosphate acyltransferase (GPAT1) and lysophosphatidic acid acyltransferase (LPAT1), in oleaginous Phaeodactylum tricornutum and determined their roles in microalgal lipogenesis.Engineered P. tricornutum strains showed enhanced growth and photosynthetic efficiency compared with that of the wild-type during the growth phase of the cultivation period. However, both the cell types reached stationary phase on day 7. Overexpression of GPAT1 and LPAT1 increased the TAG content by 2.3-fold under nitrogen-replete conditions without compromising cell growth, and they also orchestrated the expression of other key genes involved in TAG synthesis. The transgenic expression of GPAT1 and LPAT1 influenced the expression of malic enzyme and glucose 6-phosphate dehydrogenase, which enhanced the levels of lipogenic NADPH in the transgenic lines. In addition, GPAT1 and LPAT1 preferred C16 over C18 at the sn-2 position of the glycerol backbone.Overexpression of GPAT1 together with LPAT1 significantly enhanced lipid content without affecting growth and photosynthetic efficiency, and they orchestrated the expression of other key photosynthetic and lipogenic genes. The lipid profile for elevated fatty acid content (C16-CoA) demonstrated the involvement of the prokaryotic TAG pathway in marine diatoms. The results suggested that engineering dual metabolic nodes should be possible in microalgal lipid metabolism. This study also provides the first demonstration of the role of the prokaryotic TAG biosynthetic pathway in lipid overproduction and indicates that the fatty acid profile can be tailored to improve lipid production.

The fast growing photosynthetic microalgae have been widely used in aquaculture, food, health, and biofuels. Recent findings in the diatom has proposed a pivotal role of NADP-malic enzyme in generation of NADPH as an important supply of reducing power for fatty acid biosynthesis. To test the lipogenic malic enzyme for fatty acid synthesis in green algae, here the malic enzyme gene PtME from the oleaginous diatom Phaeodactylum tricornutum was expressed in a representative green microalga Chlorella pyrenoidosa.The engineered C. pyrenoidosa strain showed higher enzymatic activity of malic enzyme which subsequently promoted fatty acid synthesis. The neutral lipid content was significantly increased by up to 3.2-fold than wild type determined by Nile red staining, and total lipid content reached 40.9 % (dry cell weight). The engineered strain exhibited further lipid accumulation subjected to nitrogen deprivation condition. Upon nitrogen deprivation, engineered microalgae accumulated total lipid up to 58.7 % (dry cell weight), a 4.6-fold increase over the wild type cells under normal culture condition. At cellular level, increased volume and number of oil bodies were observed in the engineered microalgal cells.These findings suggested that malic enzyme is a pivotal regulator in lipid accumulation in green microalga C. pyrenoidosa, and presenting a breakthrough of generating ideal algal strains for algal nutrition and biofuels.

The article aimed mainly to research the influence of silicane on the hydration mechanism of cement paste containing different dosages silicane using Standard consistency water consumption, the setting time, fluidity, porosity and the degree of hydration test. Meanwhile, the Micro-structures mechanism of cement paste were researched by the Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Nitrogen-absorption and Scanning electron microscopy (SEM). Modified cement paste specimens were prepared by adding 1%, 3% and 5% silicane into control cement paste, respectively. the Standard consistency water consumption and the setting time were evaluated using Vicat apparatus. Non-evaporable water content was employed to assess the degree of hydration of the cement paste. The fluidity of cement paste specimens was characterized using flow table apparatus. Experimental results showed that for the silicane and mix designs used in the article, the incorporation of silicane generally increased the fluidity, porosity and setting time, however, decreased the degree of hydration and Standard consistency water consumption compared with the control cement paste. In addition, the analysis of XRD, FT-IR, Nitrogen-absorption test and SEM revealed the hydration mechanism and the connection between macroscopic and micro-mechanism of cement paste incorporating different dosages silicane.

Microalgae have emerged as the potential source for value-added products such as polyunsaturated fatty acids (PUFAs). Metabolic engineering of multiple metabolic pathways has promoted eicosapentaenoic acid (EPA) production in microalgae, however, further improvement is warranted owing to the burgeoning demand. Here we improved the microalgal strains by adaptive evolution under hyposalinity treatment, which showed that 70% salinity potentiated the algae to enhance PUFAs. To exploit the maximal PUFA production potential of evolved strains, we subjected evolved algae to light, temperature and fulvic acid treatment. Amongst, fulvic acid (15 mg/L) enhanced growth and achieved the highest EPA content (13.9%) in the evolved diatom. Fulvic acid enhanced antioxidant potential and unprecedently governed the expression of PUFA and lipid biosynthetic genes. Collectively, this investigation demonstrates the efficacy of adaptive evolution empowered by fulvic acid and exemplifies a feasible strain improving strategy to harness the biotechnological potential of microalgae.

Obesity is a metabolic syndrome worldwide that causes many chronic diseases. Recently, we found an antiobesity effect of flaxseed polysaccharide (FP), but the mechanism remains to be elucidated. In this study, rats were first induced to develop obesity by being fed a high-fat diet. The obese rats were then fed a control diet, AIN-93M (group HFD), or a 10% FP diet (group FPD). The body weight, body fat, adipose tissue and liver sections, serous total triglycerides, levels of fasting blood glucose in serum, serous insulin, inflammatory cytokines in serum, and serous proteins within the leptin–neuropeptide Y (NPY) and AMP-activated protein kinase (AMPK) signaling pathway were determined and analyzed. FP intervention significantly reduced body weight and abdominal fat from 530 ± 16 g and 2.15% ± 0.30% in group HFD to 478 ± 10 g and 1.38% ± 0.48% in group FPD, respectively. This effect was achieved by removing leptin resistance possibly by inhibiting inflammation and recovering satiety through the significant downregulation of NPY and the upregulation of glucagon-like peptide 1. Adiponectin was then significantly upregulated probably via the gut–brain axis and further activated the AMPK signaling pathway to improve lipid metabolism including the improvement of lipolysis and fatty acid oxidation and the suppression of lipogenesis. This is the first report of the proposed antiobesity mechanism of FP, thereby providing a comprehensive understanding of nonstarch polysaccharides and obesity.

Microalgal metabolic engineering holds great promise for the overproduction of a wide range of commercial bioproducts. It demands simultaneous manipulation of multiple metabolic nodes. However, high-efficiency promoters have been lacking.Here we report a strong constitutive promoter Pt211 in expressing multiple target genes in oleaginous microalga Phaeodactylum tricornutum. Pt211 was revealed to contain significant cis-acting elements. GUS reporter and principal genes glycerol-3-phosphate acyltransferase (GPAT) and diacylglycerol acyltransferase 2 (DGAT2) involved in triacylglycerol biosynthesis were tested under driven of Pt211 in P. tricornutum. GUS staining and qPCR analysis showed strong GUS expression. DGAT2 and GPAT linked with a designed 2A sequence exhibited higher transcript abundances than WT, while algal growth and photosynthesis were not impaired.The total lipid content increased notably by 2.6-fold compared to WT and reached up to 57.5% (dry cell weight). Overall, our findings report a strong promoter and a strategy for coordinated manipulation of complex metabolic pathways.

This study investigates the prospective of utilizing kitchen wastewater and food wastes, biofuels industry byproducts as alternative water and carbon sources. Kitchen wastewater did not impede cellular growth rate of the evolved Phaeodactylum strain E70, which indicates its potential as an alternative to freshwater resources. Among the organic wastes assessed, food waste hydrolysate significantly increased cell growth. Supplement of crude glycerol in cultivation medium enhances the total fatty acid content. Mixed food waste hydrolysate and crude glycerol remarkably increased both the cell density and total fatty acid content. Also, the supplement of butylated hydroxytoluene alleviated the oxidative stress induced by impurities in organic wastes and concomitantly increased microalgal total fatty acids and polyunsaturated fatty acids content. The experimental results reported in this study show that a waste-based biorefinery could lead to utilization of organic waste resources for the efficient production of value-added products.

Geopolymer is a new green eco-friendly gel material. However, one of the distinguishing features of geopolymer is prone to cause high water absorption and poor waterproof performance, deteriorating properties such as durability. This paper investigated the effect on the waterproof performances of different silane coupling agents (SCAs) and different SCAs dosages (0 wt%–4 wt%) of metakaolin-based geopolymer. The performance was tested from aspects of capillary water absorption, capillary porosity, water resistance, filter loss and water retention volume (WRV), contact angle, wettability, and hydration degree. Meanwhile, the microstructure mechanism was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transformation infrared Spectroscope (FT-IR), and BET (Brunauer-Emmett-Teller). The results showed that an appropriate dosage, whichever SCA was incorporated, would significantly reduce capillary water absorption, capillary porosity, with water resistance, and contact angle being enhanced. The hydration degree showed that incorporating a small dosage of SCAs could boost the early hydration reaction of geopolymer systems, resulting in performance improvement. Under the same SCA dosage, the waterproof performance of KH560 [γ-(2,3-epoxypropoxy)propytrimethoxysilane]-modified geopolymer was better than that of KH550 [γ-ammoniapropyltriethoxysilane]-modified geopolymer. Moreover, the FT-IR and XRD tests revealed that the incorporation of SCAs hardly destroyed the main crystal structure of geopolymer. Besides, the SEM test demonstrated that moderate dosages of SCAs modified geopolymer tightly connected internally than control geopolymer. In addition, the BET test visually identified the reason for the performance improvement. The experiments revealed the hydration mechanism of SCA-modified geopolymer. By enhancing waterproof on geopolymer, the modified geopolymer could effectively improve the deteriorating effects of harmful ions on materials through the process of water transmission.

Hydrated salts phase change materials (PCMs) have a great potential for use in floor radiant heating considering outstanding cost competitiveness and remarkable energy storage density. However, their inappropriate phase change temperatures and the limited methods for temperature adjustment have hindered their widespread applications. Herein, using the formation of non-eutectic mixture to realize phase change temperature adjustment, a novel composite PCM used in the floor radiant heating was developed based on sodium acetate trihydrate (SAT) as main PCM, glycine as temperature modifier and Na2HPO4·12H2O as nucleating agent. The temperature regulation mechanism was discussed and properties of the composite PCM were investigated. The results showed that glycine could regulate melting temperature of SAT from 48.34 to 58.38 °C, ascribing to the formation of hydrogen bond between them. Thereinto, the mixture containing 12% glycine melted at 48.62 °C with enthalpy of 258.5 J g−1, making it applicable to the floor radiant heating. With the addition of 0.5% Na2HPO4·12H2O, the crystallization behavior of the composite PCM was promoted with a low supercooling degree (3.62 °C). The composite PCM presented a melting temperature of 47.55 °C with enthalpy of 256.5 J g−1, good thermal stability and reliability, indicating that the material can be promisingly engineered into the floor radiant heating.

Microbial degradation is considered the most promising method for removing phthalate acid esters (PAEs) from polluted environments; however, a comprehensive genomic understanding of the entire PAE catabolic process is still lacking. In this study, the repertoire of PAE catabolism genes in the metabolically versatile bacterium Rhodococcus sp. 2G was examined using genomic, metabolic, and bioinformatic analyses. A total of 4930 coding genes were identified from the 5.6 Mb genome of the 2G strain, including 337 esterase/hydrolase genes and 48 transferase and decarboxylase genes that were involved in hydrolysing PAEs into phthalate acid (PA) and decarboxylating PA into benzoic acid (BA). One gene cluster (xyl) responsible for transforming BA into catechol and two catechol-catabolism gene clusters controlling the ortho (cat) and meta (xyl &mhp) cleavage pathways were also identified. The proposed PAE catabolism pathway and some key degradation genes were validated by intermediate-utilising tests and real-time quantitative polymerase chain reaction. Our results provide novel insight into the mechanisms of PAE biodegradation at the molecular level and useful information on gene resources for future studies.

In the current study, we compared protein profiles in gills of Perna viridis after exposure to Prorocentrum lima, a dinoflagellate producing DSP toxins, and identified the differential abundances of protein spots using 2D-electrophoresis. After exposure to P. lima, the level of okadaic acid (a main component of DSP toxins) in gills of P. viridis significantly increased at 6 h, but mussels were all apparently healthy without death. Among the 28 identified protein spots by MALDI TOF/TOF-MS, 12 proteins were up-regulated and 16 were down-regulated in the P. lima-exposed mussels. These identified proteins were involved in various biological activities, such as metabolism, cytoskeleton, signal transduction, response to oxidative stress and detoxification. Taken together, our results indicated that the presence of P. lima caused DSP toxins accumulation in mussel gill, and might consequently induce cytoskeletonal disorganization, oxidative stress, a dysfunction in metabolism and ubiquitination/proteasome activity.

Haematococcus pluvialis is a main biological resource for the antioxidant astaxanthin production, however, potential modulators and molecular mechanisms underpinning astaxanthin accumulation remain largely obscured. We discovered that provision of ethanol (0.4%) significantly triggered the cellular astaxanthin content up to 3.85% on the 4th day of treatment. Amongst, 95% of the accumulated astaxanthin was esterified, particularly enriched with monoesters. Ultrastructural analysis revealed that ethanol altered cell wall structure and physiological properties. Antioxidant analyses revealed that astaxanthin accumulation offset the ethanol induced oxidative stress. Ethanol treatment reduced carbohydrates while increased lipids and jasmonic acid production. Transcriptomic analysis uncovered that ethanol orchestrated the expression of crucial genes involved in carotenogenesis, e.g. PSY, BKT and CRTR-b were significantly upregulated. Moreover, methyl jasmonic acid synthesis was induced and played a major role in regulating the carotenogenic genes. The findings uncovered the novel viewpoint in the intricate transcriptional regulatory mechanisms of astaxanthin biosynthesis.

Abstract Background Despite the great potential of marine diatoms in biofuel sector, commercially viable biofuel production from native diatom strain is impractical. Targeted engineering of TAG pathway represents a promising approach; however, recruitment of potential candidate has been regarded as critical. Here, we identified a glycerol-3-phosphate acyltransferase 2 (GPAT2) isoform and overexpressed in Phaeodactylum tricornutum . Results GPAT2 overexpression did not impair growth and photosynthesis. GPAT2 overexpression reduced carbohydrates and protein content, however, lipid content were significantly increased. Specifically, TAG content was notably increased by 2.9-fold than phospho- and glyco-lipids. GPAT2 overexpression elicited the push-and-pull strategy by increasing the abundance of substrates for the subsequent metabolic enzymes, thereby increased the expression of LPAAT and DGAT . Besides, GPAT2-mediated lipid overproduction coordinated the expression of NADPH biosynthetic genes. GPAT2 altered the fatty acid profile in TAGs with C16:0 as the predominant fatty acid moieties. We further investigated the impact of GPAT2 on conferring abiotic stress, which exhibited enhanced tolerance to hyposaline (70%) and chilling (10 ºC) conditions via altered fatty acid saturation level. Conclusions Collectively, our results exemplified the critical role of GPAT2 in hyperaccumulating TAGs with altered fatty acid profile, which in turn uphold resistance to abiotic stress conditions.

Microalgal long-chain polyunsaturated fatty acids (LC-PUFAs) have emerged as promising alternatives to depleting fish oils. However, the overproduction of LC-PUFAs in microalgae has remained challenging. Here, we report a sequential metabolic engineering strategy that systematically overcomes the metabolic bottlenecks and overproduces LC-PUFAs. Malonyl CoA-acyl carrier protein transacylase, catalyzing the first committed step in type II fatty acid synthesis, and desaturase 5b, involved in fatty acid desaturation, were coordinately expressed in Phaeodactylum tricornutum. Engineered microalgae hyper-accumulated LC-PUFAs, with arachidonic acid (ARA) and docosahexaenoic acid (DHA) contents of up to 18.98 μg/mg and 9.15 μg/mg (dry weight), respectively. Importantly, eicosapentaenoic acid (EPA) was accumulated up to a highest record of 85.35 μg/mg by metabolic engineering. ARA and EPA were accumulated mainly in triacylglycerides, whereas DHA was found exclusively in phospholipids. Combinatorial expression of these critical enzymes led to the optimal increment of LC-PUFAs without unbalanced metabolic flux and demonstrated the practical feasibility of generating sustainable LC-PUFA production.

Patatin-like phospholipase domain-containing protein 3 (PNPLA3) has been associated with nonalcoholic fatty liver disease which promoted hepatic lipid synthesis. With high lipid content, microalgae are found to be a potential source of biofuel. Phaeodactylum tricornutum, a fast-growing and oleaginous microalga, is a promising target for enhancing the biofuel by means of metabolic engineering. Here a putative PtPNPLA3 gene from P. tricornutum was cloned and characterized in transgenic P. tricornutum for the first time. Amino acid sequence analysis showed a high homology between PNPLA3 from P. tricornutum and other organisms. Overexpression of PtPNPLA3 increased the transcript level of PtPNPLA3 by 70% in transgenic microalgae compared to wild type. The neutral lipid content in transgenic microalgae was significantly increased by 70%, representing a notable enhancement of the lipid productivity in the transgenic microalgae. The fatty acid profile was also altered as determined by GC–MS analysis, with a significant increase of C20:4 in the transgenic microalgae compared to wild type. This work identified a microalgal PNPLA3 and proved it to be an important node in regulating lipid accumulation in microalgae, also demonstrating an efficient way to improve lipid productivity in microalgae by metabolic engineering.

The rats were fed with water dissolved Y3+ at different levels (0, 53.4, 5340 mg·L−1) for 7 months. The gene expression in brain tissue was detected with oligonucleotide microarray. The results show that, compared to the control, 789 genes express differentially, 507 over-expressed genes and 282 under-expressed genes in the high-dose group (5340 mg·L−1), of which, most were related to cell receptor, cell signal and transmission, and ionic passage. 44 genes were found to express differentially including 32 over-expressed genes and 12 under-expressed genes in the low-dose group (53. 40 mg·L−1), of which, most were related to cell skeleton and movement, immunity, and DNA binding protein. These results suggest that Y3+ can change the expression of some genes, which may be responsible for the toxicity of rare earths on learning and memory.

To explore the genetic diversity and paralytic shellfish poisoning (PSP) toxin profile of the Alexandrium tamarense species complex along the coast of China, 67 strains of A. tamarense from the China Sea were collected and genetic diversity were analyzed based on the rDNA sequences. In addition, PSP toxin compositions and contents were detected by HPLC. According to the 5.8S rDNA and ITS, and LSU rDNA D1–D2 sequence, A. tamarense in the China Sea comprises at least Group IV and Group I ribotypes. In these Chinese strains, the toxins with the highest concentration in the profile were C1/2, gonyautoxins 1/4 (GTX1/4) and neosaxitoxin (NEO). However, the toxin profiles were atypical and C1/2 toxins were not detected in some strains. No strict correlation was observed between the PSP toxins profile and the geographical distribution.

Lipid droplets (LDs) are lipid monolayer-enclosed organelles comprising a lipid core and surface associated-proteins. However, the protein components and their regulatory functions in LDs have remained largely unknown in oleaginous diatoms. In this study, we identified a gene encoding lipid droplet (LD)-associated protein (PtLDP1) in Phaeodactylum tricornutum and examined its function. The PtLDP1 showed homology to the diatom-oleosome-associated protein 1 (DOAP1) from Fistulifera. Overexpression of the PtLDP1 gene elevated lipid content, enlarged LD size and increased relative expression levels of key genes involved in triacylglycerol (TAG) and fatty acid biosynthesis. In contrast, knockdown of PtLDP1 by RNAi decreased lipid and TAG content, and subsequently reduced LD size. In addition, LDs were isolated from P. tricornutum cells and the proteome of LDs was identified by mass spectrometry. We found that PtLDP1 was a significant protein in the LD proteome. Importantly, labeling of enhanced yellow fluorescent protein (EYFP) confirmed that the PtLDP1 was localized to the LDs. Altogether, our data suggest that the PtLDP1 could be an important LD-associated protein contributing to regulation of TAG synthesis and lipogenesis. The findings will provide new targets for genetic improvement of oleaginous microalgae.

The succession of dominant phytoplankton species plays an important role in harmful algal blooms. However, the molecular mechanism of algal succession remains largely unclear, including the most commonly occurring diatom/dinoflagellate succession. Here we investigated the responses of the diatom Phaeodactylum tricornutum during mixed culture with the potentially toxic dinoflagellate Alexandrium tamarense. The growth of P. tricornutum was significantly inhibited within 24 h in mixed culture. Organelles such as the chloroplasts and mitochondria of P. tricornutum were severely damaged. Transcriptional responses in P. tricornutum were revealed by RNA-seq. Genes involved in glycolysis, TCA cycle, β-oxidation, carbon fixation and oxidation phosphorylation were downregulated, indicating the inhibition of energy metabolism. Several genes associated with check points and cell cycle were also downregulated, suggesting the suppression of DNA replication and cell division. Taking into account the upregulation of genes involved in endocytosis and transporter ABCB1, P. tricornutum could perceive certain allelochemicals released from A. tamarense, which played a role in their interaction. Additionally, a family of leucine-rich repeat receptor-like kinases was upregulated, suggesting that flagellin-sensitive mediated cell-cell interactions are responsible for toxic effect other than allelopathy. Here we showed a molecular overview of interactions between diatom and dinoflagellate, thereby provide molecular insight into the unraveled mechanisms on the effects of toxic species on non-toxic species.

To investigate the mechanism of genotype differences in ciprofloxacin (CIP) accumulation, this study was designed to compare the tolerance and metabolic responses to CIP exposure between low (Cutai) and high (Sijiu) CIP-accumulation cultivars of Brassica parachinensis. Decreases in biomass and chlorophyll content were significantly greater (p < 0.05) and toxicities were more severe within cell ultrastructures of Cutai compared to Sijiu. A sequential growth test also revealed that Sijiu was more tolerant to CIP stress compared to Cutai. Meanwhile, significantly higher (p < 0.05) root parameters and higher areas of the stele and xylem may be responsible for the increased uptake and transport of CIP in Sijiu. Ultra performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC–ESI-MS/MS) analysis revealed that CIP was metabolized to three major metabolites by the hydroxylation and breakdown of the piperazinyl substituent in the CIP molecule. The enhanced metabolic transformation of CIP in Sijiu indicated a more efficient capacity to detoxify, which in turn favored an increased accumulation of CIP in this cultivar. Thus, the present study demonstrated that the stronger tolerance and metabolism of Sijiu to CIP were responsible for its high CIP accumulation, suggesting an evolutionary mechanism for adaptation to environmental stress.

Chrysolaminarin, the primary polysaccharide reservoir in some marine algae, has attracted much attention due to its broad health properties. However, its biosynthetic pathway and regulation mechanisms have rarely been reported which hinders the improvement of production efficiency. Therefore, this study aims to identify key metabolic nodes in the chrysolaminarin biosynthetic pathway. A phosphoglucomutase (PGM) in the model microalga Phaeodactylum tricornutum, revealing its critical role in chrysolaminarin biosynthesis is identified. PGM overexpression significantly elevates chrysolaminarin content by 2.54-fold and reaches 25.6% of cell dry weight; while algal growth and photosynthesis are not impaired. Besides, PGM overexpression up- and down-regulates the expression of chrysolaminarin and lipid biosynthetic genes, respectively. Microscopic analysis of aniline blue stained cells reveals that overproduced chrysolaminarin localized predominantly in vacuoles. Lipidomic analyses reveal that PGM overexpression significantly reduces the lipid content. The findings reveal the critical role of PGM in regulating the carbon flux between carbohydrate and lipid biosynthesis in microalgae, and provide a promising candidate for high efficiency production of chrysolaminarin.

Floor radiant heating embedded phase change materials (PCMs) are a prospective field owing to its highly efficient energy-saving effect and comfortable thermal environment. In this work, using a non-eutectic mixture comprised of NaAc∙3H2O (main PCM) and glycine (temperature regulator) as PCM, and expanded graphite (EG) as supporting material, a novel composite PCM with high thermal performance used in the heat exchanger for the floor radiant heating was developed. The composition of the composite PCM was optimized, and its properties were studied. The results showed that the mixture containing 12% glycine was favorable due to its suitable phase change temperature (48.62 °C) and high phase change enthalpy (258.5 kJ·kg−1). The addition of 12% EG into the mixture could enhance thermal conductivity and prevent leakage of the mixture simultaneously. The resulting composite PCM melted at 47.14 °C with phase change enthalpy of 214.7 kJ·kg−1, supercooling degree of 1.49 °C and thermal conductivity of 6.400 W m−1 K−1. The composite PCM also presented a good thermal reliability. Hence, the as-prepared composite PCM would be of great promise for use in the heat exchanger for the floor radiant heating. Besides, the present work is expected to provide a new pathway for exploring new types of PCMs.

In order to improve the spatial resolution of a magnetic near field probe, the design method combining multiple ports with multiple production processes has been proven effective. However, the asymmetry of transmission structure introduced by the junction between two different processes is a key problem that limits the performance of these probes. In this paper, a differential magnetic near field probe (diff-H-probe) combining flexible printed circuit (FPC) process with print circuit board (PCB) process has been manufactured to achieve high spatial resolution. The measurement results show that this probe can recognize a serpentine line with <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$100~\mu \text{m}$ </tex-math></inline-formula> -width of trace and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$100~\mu \text{m}$ </tex-math></inline-formula> -space between traces. Meanwhile, an asymmetric calibration method (ACM) has been applied to significantly improve the performance of the diff-H-probe. Some key parameters of the probe with and without using the ACM are compared by using an air-dielectric microstrip line. The compared results show that the detection frequency range of the proposed probe is broaden to 12 GHz. Moreover, the results also demonstrate that the ACM can improve the differential electric field suppression up to 4.1 dB and improve the common mode electric field suppression to 20 dB at the frequency below 12 GHz.

Okadaic acid (OA), a main component of diarrheic shellfish poisoning (DSP) toxins, is a strong and specific inhibitor of the serine/threonine protein phosphatases PP1 and PP2A. However, not all of the OA-induced effects can be explained by this phosphatase inhibition, and controversial results on OA are increasing. To provide clues on potential mechanisms of OA other than phosphatase inhibition, here, acute toxicity of OA was evaluated in zebrafish, and changes in gene expression in zebrafish liver tissues upon exposure to OA were observed by microarray. The i.p. ED50 (6 h) of OA on zebrafish was 1.54 μg OA/g body weight (bw). Among the genes analyzed on the zebrafish array, 55 genes were significantly up-regulated and 36 down-regulated in the fish liver tissue upon exposure to 0.176 μg OA/g bw (low-dose group, LD) compared with the low ethanol control (LE). However, there were no obvious functional clusters for them. On the contrary, fish exposure to 1.760 μg OA/g bw (high-dose group, HD) yielded a great number of differential expressed genes (700 up and 285 down) compared with high ethanol control (HE), which clustered in several functional terms such as p53 signaling pathway, Wnt signaling pathway, glutathione metabolism and protein processing in endoplasmic reticulum, etc. These genes were involved in protein phosphatase activity, translation factor activity, heat shock protein binding, as well as transmembrane transporter activity. Our findings may give some useful information on the pathways of OA-induced injury in fish.

P-glycoprotein (P-gp or ABCB1) belongs to the family of ATP-binding cassette (ABC) transporters responsible for multixenobiotic resistance (MXR) in aquatic organisms. To provide more information of P-gp in shellfish, in this study, complete cDNA of P-gp in three bivalve species including Ruditapes philippinarum, Scapharca subcrenata and Tegillarca granosa were cloned and its expressions in gill, digestive gland, adductor muscle and mantle of the three bivalves were detected after exposure to Prorocentrum lima, a toxogenic dinoflagellate. The complete sequences of R. philippinarum, S. subcrenata and T. granosa P-gp showed high homology with MDR/P-gp/ABCB proteins from other species, having a typical sequence organization as full transporters from the ABCB family. Phylogenetic analyses revealed that the amino acid sequences of P-gp from S. subcrenata and T. granosa had a closest relationship, forming an independent branch, then grouping into the other branch with Mytilus californianus, Mytilus galloprovincialis and Crassostrea gigas. However, P-gp sequences from R. philippinarum were more similar to the homologs from the more distantly related Aplysia californica than to homologs from S. subcrenata and T. granosa, suggesting that bivalves P-gp might have different paralogs. P-glycoprotein expressed in all detected tissues but there were large differences between them. After exposure to P. lima, the expression of P-gp changed in the four tissues in varying degrees within the same species and between different species, but the changes in mRNA and protein level were not always synchronous.

This paper aimed to investigate the effect of different dosages silicane on waterproof mechanism and micro-structure of control and modified cement mortar incorporated with silicane using water absorption of capillarity, crack resistance, wettability, permeability resistance and degree of hydration test. At the same time, the micro-structure mechanism of cement mortar were researched by the Scanning electron microscopy (SEM), the X-ray diffraction (XRD), the Fourier transform-infrared spectroscopy (FT-IR) and Nitrogen-absorption test. Modified cement mortar were prepared by incorporating 1%, 3% and 5% silicane into control cement mortar, respectively. The experimental results shown that for the different dosages silicone and mix designs used in this paper, the addition of silicane improved the crack resistance, contact angle and the permeability resistance while decreased the water absorption of capillarity compared with control cement mortar, which indicated that the waterproof of modified cement mortar was strengthened generally. The Non-evaporable water content was used to evaluate the degree of hydration of control modified cement paste. Experimental results illustrated that degree of hydration was restrained because of the incorporation of silicane, which could be testified using the XRD and FT-IR test. In addition, in comparison with control cement mortar, the maximum adsorption capacity and total pore volume of cement mortar were increased by the SEM and Nitrogen-absorption test, manifesting that most of pores of modified cement mortar was closed. Most importantly, the hydration and waterproof mechanism was revealed.

Diarrheic shellfish poisoning (DSP) toxins are produced by harmful microalgae and accumulate in bivalve mollusks, causing various toxicity. These toxic effects appear to abate with increasing DSP concentration and longer exposure time, however, the underlying mechanisms remain unclear. To explore the underlying molecular mechanisms, de novo transcriptome analysis of the digestive gland of Perna viridis was performed after Prorocentrum lima exposure. RNA-seq analysis showed that 1886 and 237 genes were up- and down-regulated, respectively after 6 h exposure to P. lima, while 265 genes were up-regulated and 217 genes were down-regulated after 96 h compared to the control. These differentially expressed genes mainly involved in Nrf2 signing pathways, immune stress, apoptosis and cytoskeleton, etc. Combined with qPCR results, we speculated that the mussel P. viridis might mainly rely on glutathione S-transferase (GST) and ABC transporters to counteract DSP toxins during short-term exposure. However, longer exposure of P. lima could activate the Nrf2 signaling pathway and inhibitors of apoptosis protein (IAP), which in turn reduced the damage of DSP toxins to the mussel. DSP toxins could induce cytoskeleton destabilization and had some negative impact on the immune system of bivalves. Collectively, our findings uncovered the crucial molecular mechanisms and the regulatory metabolic nodes that underpin the defense mechanism of bivalves against DSP toxins and also advanced our current understanding of bivalve defense mechanisms.

Dual probe is capable of simultaneously measuring electric and magnetic fields in the same position, given that perfectly symmetric design is realized on the transmission paths connecting the detection loop and the probe outputs. For general application, a calibration method for the asymmetric probing in near-field measurement with the dual probe is presented, in order to deal with the failure of the traditional calibration due to the asymmetric transmissions in both paths. The asymmetric probing measurement is modeled, and then the proposed calibration to eliminate the asymmetry is further derived based on two independent measurements at two directions (0° and 90°) between the probe and the microstrip line providing a known electromagnetic field at the surface. The calibration method is demonstrated with two kinds of dual probes of different coupling structure. The proposed calibration is validated by introducing the asymmetry to the probing process in the measurement of the standing wave along a conductor-backed coplanar waveguide transmission line.

This study explored the effect of Cr3C2 content (0, 0.5, 1, 1.5, and 2 mol%) on the microstructure, magnetic properties and mechanical behavior of TiC–10TiN–6WC–4C–(15,30) Ni (mol%) cermets after vacuum sintering. The results show that just Ti-based carbonitride ceramic grains and Ni-based binder phase were presented in the experimental cermets, and the mean size of ceramic grains reduced with the increase of Cr3C2 content. By adding Cr3C2 into cermets, the Cr concentration in binder phase obviously raised. However, Ti concentration in binder phase decreased continuously as Cr3C2 content increased, while the W concentration remained nearly constant. Saturation magnetization and remanence of cermets decreased with increasing Cr3C2 content, which was primarily ascribed to the increased amounts of antiferromagnetic Cr element in the Ni-based binder phase. When Cr3C2 content exceeded 0.5 mol%, cermets became paramagnetic at room temperature. Cermets with 15 and 30 mol% Ni had Curie temperatures of roughly 138 K and 28 K by 2 mol% Cr3C2 addition, respectively. Therefore, Cr3C2 addition is very effective in suppressing the ferromagnetism of cermets. Moreover, transverse rupture strength and hardness of cermets first raised and then declined with the addition of Cr3C2.

Prospective observational study.To evaluate the predictive value of the preoperative Short Form-36 survey (SF-36) scale for postoperative axial neck pain (ANP) in patients with degenerative cervical myelopathy (DCM) who underwent anterior cervical decompression and fusion (ACDF) surgery.This study enrolled patients with DCM who underwent ACDF surgery at author's Hospital between May 2010 and June 2016.Out of 126 eligible patients, 122 completed the 3-month follow-up and 117 completed the 1-year follow-up. The results showed that the preoperative social functioning (SF) subscale score of the SF-36 scale was significantly lower in patients with moderate-to-severe postoperative ANP than in those with no or mild postoperative ANP at both follow-up timepoints (P < .05). ACDF at C4-5 level resulted in a higher ANP rate than ACDF at C5-6 or C6-7 level, both at 3-month (P = .019) and 1-year (P = .004) follow-up. Multivariate logistic regression analysis confirmed that the preoperative social functioning subscale score was an independent risk factor for moderate-to-severe postoperative ANP at 3 months and 1 year after surgery, and preoperative NRS was an independent risk factor at 1-year follow-up. No other demographic, clinical, or radiographic factors were found to be associated with postoperative ANP severity (P < .05).Preoperative social functioning subscale score of SF-36 scale might be a favorable predictive tool for postoperative ANP in DCM patients who underwent ACDF surgery.

Effects of toxic Alexandrium species on Prorocentrum donghaiense were studied in co-cultures and filtrates in order to shed some light on the competition between the co-occurring harmful algae. The three live cultures of Alexandrium tamarense and Alexandrium minutum negatively affected the growth of P. donghaiense, while only A. minutum was affected by P. donghaiense when they were in 1:3 ratio of cells. Each species was affected by the co-occurring algae as could be observed by microscopy. The allelopathic effects observed in co-culture did not correlate with the measured content of the intracellular PSP toxins but matched the observed hemolytic properties of the culture filtrates, suggesting that certain hemolytic substances other than PSP toxins are responsible for the allelopathic effect of Alexandrium.

With the frequent occurrence and negative impacts of harmful algal blooms (HABs) on coastal countries throughout the world, it is urgently needed to find ways to control HABs effectively. Vermiculite, montmorillonite, palygorskite, and kaolin were modified with a Gemini surfactant to explore a new algaecide for controlling HABs. The removal efficiency of the modified clay minerals was evaluated with Chattonella marina, a typical HAB alga in China. Gemini modified vermiculite (G-VER) exhibited the highest removal rate against C. marina. When the concentration of G-VER (21.1% Gemini) was 6.5 mg/L, the removal rate reached to 100%. Dispersed in sea water for 72 h, only 3% of Gemini was released from the G-VER, indicating that the modified clay minerals had good stability in sea water and caused low impacts in the aquatic environment. G-VER is considered a potential algaecide with high efficiency and environmental safety.

To provide more information on the origin of the Ulva prolifera bloom in Qingdao sea area in China from 2007 to 2011, the diversity of green algae growing on the rafts of Porphyra yezoensis on the coast in Jiangsu Province was investigated based on ITS, rbcL and 5S sequences. Eighty-four of green algal samples from various sites and cruises in 2010 and 2011 were collected. According to ITS and rbcL sequences, samples from the rafts of P. yezoensis fell into four clades: Ulva linza-procera-prolifera (LPP) complex, Ulva flexuosa, Blidingia sp. and Urospora spp. However, based on the 5S rDNA, a more resolved DNA marker, only one of the 84 samples belonged to U. prolifera. Combined with the previous reports, it is likely that U. prolifera bloom in Qingdao sea area might consist of more than one origin, and Porphyra cultivation rafts might be one of the causes.

Bivalves naturally exposed to toxic algae have mechanisms to prevent from harmful effects of diarrhetic shellfish poisoning (DSP) toxins. However, quite few studies have examined the mechanisms associated, and the information currently available is still insufficient. Multixenobiotic resistance (MXR) is ubiquitous in aquatic invertebrates and plays an important role in defense against xenobiotics. Here, to explore the roles of P-glycoprotein (P-gp) in the DSP toxins resistance in shellfish, complete cDNA of P-gp gene in the mussel Perna viridis was cloned and analyzed. The accumulation of okadaic acid (OA), a main component of DSP toxins, MXR activity and expression of P-gp in gills of P. viridis were detected after exposure to Prorocentrum lima, a dinoflagellate producing DSP toxins in the presence or absence of P-gp inhibitors PGP-4008, verapamil (VER) and cyclosporin A (CsA). The mussel P. viridis P-gp closely matches MDR/P-gp/ABCB protein from various organisms, having a typical sequence organization as full transporters from the ABCB family. After exposure to P. lima, OA accumulation, MXR activity and P-gp expression significantly increased in gills of P. viridis. The addition of P-gp-specific inhibitors PGP-4008 and VER decreased MXR activity induced by P. lima, but had no effect on the OA accumulation in gills of P. viridis. However, CsA, a broad-spectrum inhibitor of ABC transporter not only decreased MXR activity, but also increased OA accumulation in gills of P. viridis. Together with the ubiquitous presence of other ABC transporters such as MRP/ABCC in bivalves and potential compensatory mechanism in P-gp and MRP-mediated resistance, we speculated that besides P-gp, other ABC transporters, especially MRP might be involved in the resistance mechanisms to DSP toxins.

Abstract Silane coupling agent (SCA) plays an important role in the improvement of adhesive properties of the silicone rubber (SR) sealant. In this study, three trifunctional silane coupling agents, (γ‐aminopropytriethoxysilane (APTES), (γ‐Glycidoxypropyl) methyldimethoxysilane (GDMMS), and 3‐(Trimethoxysilyl)propyl methacrylate (MPS), were used as blend additive in SR, and the effect of silane coupling agents on the properties of SR was studied. The results showed that the bond strength of samples with different combination of APTES/GDMMS, GDMMS/MPS, or APTES/MPS, was significantly improved than those of single silanes. Silanes with polar group make contribution to the bond strength increase of SR sealant. The highest bond strength value (0.53 MPa) was obtained using the combination of APTES and GDMMS. The study of the samples with (APTES and GDMMS) showed that the bond strength and tensile strength of SR increase with the increasing amount of SCA. Further increase in the SCA content makes the bond strength and tensile strength of SR sealant decrease. The increase in the amount of SCAs makes the failure modes of samples convert from adhesive failure to cohesive failure. Tack‐free time decreased linearly as the amount of SCA loading increased, while the hardness increased. It can be deduced that the trifunctional SCA has catalytic effect on the crosslinking action of SR sealant. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

In this study, changes in eight GSTs mRNA level including GST-α, GST-σ, GST-ω, GST-π, GST-μ, GST-ρ, GST-θ and microsomal GST (mGST) in the oyster Crassostrea ariakensis after exposure to Prorocentrum lima have been evaluated by quantitative real-time PCR. Additionally, the contents of five GST isoforms were detected by ELISA. After exposure to P. lima at density of 2 × 105 cells/L, mGST mRNA significantly increased in gill, while GST-σ was induced in digestive gland. After exposure to P. lima at density of 2 × 106 cells/L, GST-ω and mGST expressions increased in gill, whereas GST-α and GST-σ were induced in digestive gland. The GST content and activity in oysters exposed to P. lima also showed a different pattern when the different isoforms and organs were compared. After exposure to P. lima (2 × 106 cell/L), GST-π increased in gill but decreased in digestive gland. The total GST enzyme activity increased in gill, while remained unchanged in digestive gland. These various regulation of GST gene expressions indicated that the GSTs isoenzymes might play divergent physiological roles in the detoxification of DSP toxins in C. ariakensis.

Prorocentrum lima is a typical diarrheic shellfish poisoning (DSP) toxin-producing benthic dinoflagellate usually found attached to or associated with macrophytes, floating detritus, debris, or other substrates. In this paper, to gain a deeper understanding of the molecular and cellular responses to N limitation in P. lima, transcriptome profiling was performed. We found that most genes related to photosynthesis, porphyrin and chlorophyll metabolism were down-regulated following N limitation, while some genes concerning fatty acid biosynthesis, starch synthesis and ubiquitin pathway were up-regulated. Meanwhile, ABC transports ABCB1 and ABCG2 and glutathione S-transferase were up-regulated under N-limited conditions. These transcriptomic data were further corroborated by the biochemical analyses which revealed that starch, lipid content was increased, while photosynthetic efficiency was decreased. In addition, TEM analysis demonstrated that chloroplasts appeared smaller and were less abundant, while a major fraction of the cell volume was occupied by lipid bodies and starch granules, and thylakoid was twisted in the cells. Taking together, we proposed that N limitation could induce the accumulation of neutral lipid and starch in P. lima cells for carbon fixation trough recycling chloroplast membranes by autophagy. ABCB and ABCG transporters might be involved in the transport of DSP toxins. Our findings might provide global information for the response or adaptation of P. lima to N limitation.

Diarrhetic shellfish poisoning (DSP) toxins are key shellfish toxins that cause diarrhea, vomiting and even tumor. Interestingly, bivalves such as Perna viridis have been reported to exhibit some resistances to alleviate toxic effects of DSP toxins in a species-specific manner. Nevertheless, the molecular mechanisms underlying the resistance phenomenon to DSP toxins, particularly the mechanistic role of CYP450 is scant despite its crucial role in detoxification. Here, we exposed P. viridis to Prorocentrum lima and examined the expression pattern of the CYP450 and our comprehensive analyses revealed that P. lima exposure resulted in unique expression pattern of key CYP450 genes in bivalves. Exposure to P. lima (2 × 105 cells/L) dramatically orchestrated the relative expression of CYP450 genes. CYP2D14-like mRNA was significantly down-regulated at 6 h in gill, but up-regulated at 2 h in digestive gland compared with control counterparts (p < 0.05), while CYP3A4 mRNA was increased at 12 h in gill. After exposure to P. lima at 2 × 106 cells/L, the expression of CYP3A4 mRNA was significantly increased in digestive gland at 2 h and 12 h, while CYP2D14-like was up-regulated at 6 h. Besides, CYP3L3 and CYP2C8 also exhibited differential expression. These data suggested that CYP3A4, CYP2D14-like, and even CYP3L3 and CYP2C8 might be involved in DSP toxins metabolism. Besides, provision of ketoconazole resulted in significant decrement of CYP3A4 in digestive gland at 2 h and 12 h, while the OA content significantly decreased at 2 h and 6 h compared to control group without ketoconazole. These findings indicated that ketoconazole could depress CYP3A4 activity in bivalves thereby altering the metabolic activities of DSP toxins in bivalves, and also provided novel insights into the mechanistic role of CYP3A4 on DSP toxins metabolism in bivalves.

It is well documented that diarrhetic shellfish poisoning (DSP) toxins have strong genetic toxicity, cytotoxicity and oxidative damage to bivalve species. However, these toxic effects seem to decrease with the extension of exposure time and the increment of the toxin concentration, the mechanism involved remained unclear, though. In this paper, we found that expression of the genes related to cytoskeleton and Nrf2 signaling pathway displayed different changes over time in the gill of Perna viridis after exposure to DSP toxins-producing microalga Prorocentrum lima. During the short-term exposure (3 h and 6 h), KEAP1 gene expression was significantly up-regulated, coupled with up-regulation of MRP, ABCB1 and CAT transcriptions and down-regulation of GPx1 and NQO1 mRNA. After longer exposure to high density of P. lima, Nrf2 was significantly up-regulated, accompanied with up-regulation of Nrf2 pathway related genes such as NQO1, SOD, GST-ω and ABCB1, whereas KEAP1 was down-regulated. TUBA1C and TUBB1 transcripts were significantly down-regulated after short-term exposure of P. lima, but both of them were up-regulated at 96 h after exposure to high density of P. lima. Paraffin section demonstrated that P. lima had a strong damage on the gill of mussels during the short-term exposure. However, the negative effect to the gill decreased, and the gill restored after longer exposure (96 h). Taking together, we proposed that P. lima had a negative impact on cytoskeleton of mussel gill tissue, could cause oxidative damage to the gills. However, longer exposure of P. lima in high density could activate Nrf2 signaling pathway, thereby reducing the influence of toxin on mussel. Our study might provide a novel clue for the resistance mechanism of shellfish to DSP toxins.

Microalgae have long been considered as potential biological feedstock for the production of wide array of bioproducts, such as biofuel feedstock because of their lipid accumulating capability. However, lipid productivity of microalgae is still far below commercial viability. Here, a glucose-6-phosphate dehydrogenase from the oleaginous microalga Nannochloropsis oceanica is identified and heterologously expressed in the green microalga Chlorella pyrenoidosa to characterize its function in the pentose phosphate pathway. It is found that the G6PD enzyme activity toward NADPH production is increased by 2.19-fold in engineered microalgal strains. Lipidomic analysis reveals up to 3.09-fold increase of neutral lipid content in the engineered strains, and lipid yield is gradually increased throughout the cultivation phase and saturated at the stationary phase. Moreover, cellular physiological characteristics including photosynthesis and growth rate are not impaired. Collectively, these results reveal the pivotal role of glucose-6-phosphate dehydrogenase from N. oceanica in NADPH supply, demonstrating that provision of reducing power is crucial for microalgal lipogenesis and can be a potential target for metabolic engineering.

To understand the mechanism controlling cultivar differences in the accumulation of ciprofloxacin (CIP) in Chinese flowering cabbage (Brassica parachinensis L.), low-molecular-weight organic acids (LMWOAs) secreted from the roots of high- and low-CIP cultivars (Sijiu and Cutai, respectively) and their effects on the bioavailability of CIP in soil were investigated. Significant differences in the content of LMWOAs (especially maleic acid) between the two cultivars played a key role in the variation in CIP accumulation. Based on the Freundlich sorption coefficient (K f ) and distribution coefficient (K d ), the presence of LMWOAs reduced the CIP sorption onto soil particles, and higher concentrations of LMWOAs led to less CIP sorption onto soil. On the other hand, LMWOAs enhanced CIP desorption by lowering the solution pH, which changed the surface charge of soil particles and the degree of CIP ionization. LMWOAs promoted CIP desorption from soil by breaking cation bridges and dissolving metal cations, particularly Cu2+. These results implied that the LMWOAs (mainly maleic acid) secreted from Sijiu inhibited CIP sorption onto soil and improved CIP desorption from soil to a greater extent than those secreted from Cutai, resulting in higher bioavailability of CIP and more uptake and accumulation of CIP in the former.

Abstract Microalgal metabolic engineering holds great promise for algal biofuels. However, identification of the key lipid metabolic target remains challenging due to its complex regulation. In this study, we advocated an alternative strategy that potentially rewired lipid metabolism by unprecedented mechanisms. PNPLA3, a human protein associated with non-alcoholic fatty liver disease (NAFLD), was firstly tested in microalgae for enhancing lipid accumulation. HsPNPLA3 was synthesized with a site mutation (I148M) and expressed in a model diatom Phaeodactylum tricornutum . Heterogeneous HsPNPLA3-I148M was successfully integrated, transcribed and expressed. Lipidomic analyses revealed that HsPNPLA3-I148M significantly elevated TAG content by 1.55-fold in algae, while algal growth and photosynthetic rate were not impaired. Fatty acid profile showed that content of C16:0, C18:1 and C20:4 was increased by 1.43-, 4.18- and 4.3-fold, respectively, which implied that HsPNPLA3-I148M might regulate the fatty acid substrate preference. Overall, the findings demonstrated that human PNPLA3 played a potential role in elevating TAG accumulation by regulating lipogenic enzymes and provide unprecedented insights into its functional significance.

Abstract There has been growing interest in using microalgae as production hosts for a wide range of value‐added compounds. However, microalgal genetic improvement is impeded by lack of genetic tools to concurrently control multiple genes. Here, we identified two novel strong promoters, designated Pt202 and Pt667, and delineated their potential role on simultaneously driving the expression of key lipogenic genes in Phaeodactylum tricornutum . In silico analyses of the identified promoter sequences predicted the presence of essential core cis elements such as TATA and CAAT boxes. Regulatory role of the promoters was preliminarily assessed by using GUS reporter which demonstrated strong GUS expression. Thereafter, two key lipogenic genes including malic enzyme (PtME) and 5‐desaturase (PtD5b), were overexpressed by the two promoters Pt202 and Pt667, respectively, in P. tricornutum . Combinatorial gene overexpression did not impair general physiological performance, meanwhile neutral lipid content was remarkably increased by 2.4‐fold. GC‐MS analysis of fatty acid methyl esters revealed that eicosapentaenoic acid (EPA; C20:5) was increased significantly. The findings augment a crucial kit to microalgal genetic tools that could facilitate the multiple‐gene expression driven by various promoters, and promote microalgae for industrial bioproduction.

Okadaic acid (OA), one of the most important phycotoxins, is widely distributed around the world, concerning diarrheic shellfish poisoning (DSP), and even colorectal cancer. Here, we found that long-term exposure of OA at a low dose (80 μg kg-1 body weight) had certain effects on colonic microbiotas and tract in rat. In the OA-exposed rat, colonic epithelium layer was damaged, and relative abundance of some microbiotas were significantly changed, especially genera in Clostridiales. However, no intestinal inflammation or significant disease was observed. Combined with the increase in relative abundance of some genera in Clostridiales induced by OA in the fermentation experiment, we proposed that OA could cause damage to the intestinal epithelium and increase the relative abundance of pathogenic bacteria, thereby increasing the probability of contact between intestinal epithelium and pathogenic bacteria and leading to an easier pathogenicity.

Abstract Study design Retrospective analysis. Setting China Rehabilitation Research Center, Beijing, China. Objective To explore possible mechanisms underlying spinal cord injury (SCI) in children caused by hyperextension of the spine while dancing. Methods The clinical records of 88 children with SCI (mean age, 5.97 years; age range, 4–10 years) admitted to our hospital from January 1989 to October 2019 were retrospectively reviewed. Computed tomography and magnetic resonance imaging were performed on the day of injury. The time from injury to development of paralysis, as well as post-injury activities were surveyed, while abnormal patterns on images, the range of the involved vertebrae, and the extents of edema and atrophy were assessed. Results Among the 88 patients, 6 (6.8%) were unable to move immediately after SCI, while paralysis occurred in 42, 23, and 17 patients at &lt;30, 30–60, and &gt;60 min after SCI, respectively. The neurological level of injury of 84 patients was between T4 and T12. On sagittal T2-weighted images (T2WIs), the longitudinal range of spinal cord edema was more than one vertebral body in 65 patients, while spinal cord atrophy below T8 was found in 40 patients. On axial T2WIs, although three patients had none, long T2 signals were found in the central gray matter of seven patients. Meanwhile, necrosis of the central area combined with the peripheral white matter was observed in 57 patients, while three patients had total involvement on a cross section. Conclusion Ischemia-related damage, rather than direct trauma to the spinal cord, may play an important role in SCI due to spinal hyperextension during dancing.

The aim of this paper is to investigate the effects of different activator -to-solid ratios on water consumption, setting time, fluidity, adhesion properties, bulk density and mechanical properties at standard consistency. The microstructural mechanisms of metakaolin geopolymer were also investigated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). The experimental results showed that for the different activator to solid ratios and mix designs used in this paper, higher ratios enhanced the fluidity, consistency, and setting time. Besides, the standard consistency water consumption of the metakaolin polymer mortar was reduced. SEM and FT-IR tests revealed macroscopic phenomena where the polyaluminum silicate structure improved with increasing activator -to-solids ratios. Excessive sodium silicate reduced strength, thus affecting mechanical properties.

To develop a practical prediction model to predict the risk of deep surgical site infection (SSI) in patients receiving open posterior instrumented thoracolumbar surgery.Data of 3419 patients in four hospitals from 1 January 2012 to 30 December 2021 were evaluated. The authors used clinical knowledge-driven, data-driven, and decision tree model to identify predictive variables of deep SSI. Forty-three candidate variables were collected, including 5 demographics, 29 preoperative, 5 intraoperative, and 4 postoperative variables. According to model performance and clinical practicability, the best model was chosen to develop a risk score. Internal validation was performed by using bootstrapping methods.After open posterior instrumented thoracolumbar surgery, 158 patients (4.6%) developed deep SSI. The clinical knowledge-driven model yielded 12 predictors of deep SSI, while the data-driven and decision tree model produced 11 and 6 predictors, respectively. A knowledge-driven model, which had the best C-statistics [0.81 (95% CI: 0.78-0.85)] and superior calibration, was chosen due to its favorable model performance and clinical practicality. Moreover, 12 variables were identified in the clinical knowledge-driven model, including age, BMI, diabetes, steroid use, albumin, duration of operation, blood loss, instrumented segments, powdered vancomycin administration, duration of drainage, postoperative cerebrospinal fluid leakage, and early postoperative activities. In bootstrap internal validation, the knowledge-driven model still showed optimal C-statistics (0.79, 95% CI: 0.75-0.83) and calibration. Based on these identified predictors, a risk score for deep SSI incidence was created: the A-DOUBLE-SSI (Age, D [Diabetes, Drainage], O [duration of Operation, vancOmycin], albUmin, B [BMI, Blood loss], cerebrospinal fluid Leakage, Early activities, Steroid use, and Segmental Instrumentation) risk score. Based on the A-DOUBLE-SSI score system, the incidence of deep SSI increased in a graded fashion from 1.06% (A-DOUBLE-SSIs score ≤8) to 40.6% (A-DOUBLE-SSIs score>15).The authors developed a novel and practical model, the A-DOUBLE-SSIs risk score, that integrated easily accessible demographics, preoperative, intraoperative, and postoperative variables and could be used to predict individual risk of deep SSI in patients receiving open posterior instrumented thoracolumbar surgery.

This study aims to develop Ultraviolet-cured (UV-cured) antimicrobial coatings by dispersing epoxy resin F51–quaternary ammonium salt (QAS) as antimicrobial agents in UV-cured emulsions. The molecular structures of these F51–QAS coatings were analyzed using infrared spectroscopy. Thermogravimetric analysis was performed to evaluate the thermal stability of the antimicrobial coatings. Contact angle testing was conducted to investigate the hygroscopic wettability of the coatings. Mechanical properties such as pencil hardness, adhesion strength, flexibility and impact resistance were evaluated. Antimicrobial rate experiments were conducted to examine the antimicrobial properties of the coatings. The antimicrobial properties were examined through rate experiments against Escherichia coli and Staphylococcus aureus. The results showed that when the F51–QAS content was at 2.7%, the UV-cured antimicrobial coatings exhibited excellent overall performance with a 100% antimicrobial rate.

Abstract Polyaniline (PANI) particles were synthesized using aniline (AN), dodecyl benzene sulfonic acid (DBSA), and ammonium persulfate (APS). The particles were analyzed using scanning electron microscope (SEM), X‐ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR). A PANI/waterborne polyurethane composite material (PANI‐WPU) was obtained by combining it with polyethylene glycol (PEG600), diphenylmethane diisocyanate (MDI), dimethylol propionic acid (DMPA), N‐methyl pyrrolidone (NMP), and dibutyltin lauric acid (DBTDL). The structure was characterized by the FTIR spectrum. The mechanical characteristics of the coating film were evaluated with respect to the PANI content, as well as its water absorption, glossiness, electrochemical corrosion resistance, and acid and alkali resistance. The PANI/waterborne polyurethane film has a maximum tensile strength of 23 MPa, an elongation of 1012%, a pencil hardness of 5H, a flexibility of 2 mm, an impact resistance of 50 cm, the water absorption of 14.66%, and the glossiness of 99.9 at 60°. When the PANI content is 0.7%, the mechanical characteristics, glossiness, and anti‐corrosion performance of the composite film improve. The corrosion inhibition efficiency of the aqueous polyurethane coating film with PANI can reach 99.74%, as shown by the examination of electrochemical polarization curves and impedance spectra. The tinplate is coated with a 0.7% PANI‐WPU composite material and edge sealing. This coating provides excellent protection against acid and alkali resistance, as demonstrated by its ability to withstand immersion in 10% H 2 SO 4 and 10% NaOH solution for 90 days without any paint peeling off.

Hot stamping (or press hardening) is a new technology that is widely used in the production of advanced high-strength steel parts for automotive applications. Electrochemical measurements, including potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), and accelerated corrosion tests (the neutral salt spray test and periodic immersion test) were conducted on press-hardened samples produced from uncoated (cold-rolled and cold strip production (CSP) hot-rolled) and Al-Si-coated press-hardened steels to elucidate their distinct anti-corrosion mechanisms. The cross-sectional micromorphology and element distribution of three types of press-hardened steels after a neutral salt spray test were observed using scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDAX). The corrosion resistance of Al-Si-coated press-hardened steel was found to be significantly diminished following the hot stamping process due to the presence of microcracks and elevated iron content in the coating subsequent to austenitizing heat treatment. On the other hand, the corrosion resistance of uncoated press-hardened sheets produced from cold-rolled and CSP hot-rolled press-hardened steel was found to be proximal due to their nearly identical composition and microstructure (fully martensite) after the hot stamping process. Considering the high efficiency and energy-saving properties of hot-rolled press-hardened steel, it holds the potential to replace cold-rolled and even aluminum-silicon-coated press-hardened steel in automobile manufacturing.

Polyaniline has been extensively used for the corrosion protection of polymeric materials. However, there have been few studies on its combined antimicrobial activity when used in combination with silver molybdate. In this study, we synthesized silver molybdate (Ag2MoO4) crystals using a homogeneous precipitation method. Polyaniline-dodecylbenzenesulfonic acid/castor oil(PANI-DBSA/CO) mixtures were prepared in an encapsulated state by in situ polymerisation. Subsequently, PANI/Ag2MoO4-PU interpenetrating polymer network(IPN) composite coatings(P/A-PU) were produced by dispersing Ag2MoO4 and PANI-DBSA/CO in polyurethane using ultrasonic dispersion. The composite coatings were characterized using Fourier transform infrared spectroscopy(FTIR), X-ray diffraction analysis(XRD), and transmission electron microscopy(TEM). The study confirmed that composite coatings with uniformly dispersed nanoparticles of PANI and Ag2MoO4 encapsulated by CO and epoxy resin E-44 grease exhibit improved physico-mechanical characteristics. The research also evaluated the effect of nanoparticles on the corrosion behaviour of the coatings using electrochemical impedance spectroscopy and kinetic potential polarisation experiments. The study investigated the antimicrobial properties of P/A-PU composite coatings on Escherichia coli(E.coli) and Staphylococcus aureus(S.aureus) by conducting bacterial growth curves, protein leakage, and fluorescence staining experiments. The aim was to establish a causal connection between the coated surfaces and the observed antimicrobial properties. The study demonstrated that incorporating IPN of polyaniline polyurethane into the coating composites improved their anticorrosive properties. Furthermore, the addition of silver molybdate at a mass ratio of 0.3% resulted in a remarkable 99% antimicrobial activity against E.coli and S.aureus.

The influence of polymer emulsion, pigment filler, and dispersant on the corrosion resistance of polymer cement-based composite anti-corrosion coatings were investigated in this study. Adhesion loss rate tests and electrochemical tests were conducted on samples. The research results show that optimal corrosion resistance can be achieved with a 45 wt% dosage of emulsion, a 6 wt% dosage of pigment filler, and a 0.30 wt% dosage of dispersant. The bonding properties of bare steel bars, epoxy-coated steel bars, and polymer cement-based composite anti-corrosion coated steel bars with grout were compared. The results show that the polymer cement-based composite anti-corrosion coating can enhance the bonding properties of the samples. Furthermore, the microscopic analysis was conducted on the samples. The results demonstrate that the appropriate addition of emulsion can fill internal pores of the coating, tightly bonding hydration products with unhydrated cement particles. Moreover, incorporating a suitable dosage of functional additives enhances the stability of the coating system and leads to a denser microstructure.

Journal of Integrative Plant BiologyVolume 47, Issue 2 p. 165-171 Characterization of the Hemolytic Properties of an Extract from Phaeocystis globosa Scherffel Xi-Chun PENG, Xi-Chun PENG College of Food and Biology Engineering, South China University of Technology, Guangzhou 510640, China; Search for more papers by this authorWei-Dong YANG, Wei-Dong YANG Department of Biotechnology, Jinan University, Guangzhou 510632, ChinaSearch for more papers by this authorJie-Sheng LIU, Corresponding Author Jie-Sheng LIU Department of Biotechnology, Jinan University, Guangzhou 510632, China *Author for correspondence. Tel.: +86 (0)20 8522 8470; Fax: +86 (0)20 8522 0032; E-mail: 〈tywd@jnu.edu.cn〉.Search for more papers by this authorZhi-Ying PENG, Zhi-Ying PENG College of Food and Biology Engineering, South China University of Technology, Guangzhou 510640, China; Search for more papers by this authorSong-Hui LÜ, Song-Hui LÜ Department of Biotechnology, Jinan University, Guangzhou 510632, ChinaSearch for more papers by this authorWen-Zheng DING, Wen-Zheng DING Department of Biotechnology, Jinan University, Guangzhou 510632, ChinaSearch for more papers by this author Xi-Chun PENG, Xi-Chun PENG College of Food and Biology Engineering, South China University of Technology, Guangzhou 510640, China; Search for more papers by this authorWei-Dong YANG, Wei-Dong YANG Department of Biotechnology, Jinan University, Guangzhou 510632, ChinaSearch for more papers by this authorJie-Sheng LIU, Corresponding Author Jie-Sheng LIU Department of Biotechnology, Jinan University, Guangzhou 510632, China *Author for correspondence. Tel.: +86 (0)20 8522 8470; Fax: +86 (0)20 8522 0032; E-mail: 〈tywd@jnu.edu.cn〉.Search for more papers by this authorZhi-Ying PENG, Zhi-Ying PENG College of Food and Biology Engineering, South China University of Technology, Guangzhou 510640, China; Search for more papers by this authorSong-Hui LÜ, Song-Hui LÜ Department of Biotechnology, Jinan University, Guangzhou 510632, ChinaSearch for more papers by this authorWen-Zheng DING, Wen-Zheng DING Department of Biotechnology, Jinan University, Guangzhou 510632, ChinaSearch for more papers by this author First published: 01 March 2005 https://doi.org/10.1111/j.1744-7909.2005.00039.xCitations: 21 Supported by the National Natural Science Foundation of China (30470321), the State Key Basic Research and Development Plan of China (2001CB409710), the Key Program of Natural Science Foundation Guandong Province of China (021168), and the Science Foundation of Jinan University. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Abstract: Phaeocystis globosa Scherffel, an organism that causes harmful algal blooms, is a genus of the family Prymnesiophyta (or Haptophyta) with eurythermal and euryhaline characteristics. P. globosa has been confirmed to produce hemolytic substances, which are a mixture of liposaccharides. In the present study, the hemolytic properties of extract of P. globosa are analyzed further. The effects of temperature, pH, different divalent cations, and membrane lipids on extract-induced hemolysis are discussed, as is the possible hemolytic mechanism. The results of the present study showed that the hemolytic activity of the extract was approximately 127.1 hemolytic units (HU)/L. The hemolytic reaction became fastest and a 50% decrease in absorbance was induced at 30 min at 37 °C, and at pH 7.0; Hg2+ was the strongest inhibitor of the hemolysis compared with the other divalent cations and many membrane lipids, except for phosphatidic acid, inhibited the hemolytic activity to different degrees. These results suggest that the toxin may make pores in the surface of red blood cells and that Hg2+ either combines with the hemolysin or closes the pores, hence inhibiting its further hemolytic reaction. The toxin probably has no specific membrane receptor in the red blood cell membrane. (Managing editor: Ya-QinHAN) Citing Literature Volume47, Issue2February 2005Pages 165-171 RelatedInformation

Abstract We investigated the toxicity of Karenia mikimotoi toward three model grazers, the cladoceran Moina mongolica , the copepod Pseudodiaptomus annandalei , and the crustacean Artemia salina , and explored its chemical response upon zooplankton grazing. An induction experiment, where K. mikimotoi was exposed to grazers or waterborne cues from the mixed cultures revealed that K. mikimotoi might be toxic or nutritionally inadequate toward the three grazers. In general, direct exposure to the three grazers induced the production of hemolytic toxins and the synthesis of eicosapentaenoic acid ( EPA ). Both EPA and the hemolytic toxins from K. mikimotoi decreased the survival rate of the three grazers. In addition, the survival rates of M. mongolica , P. annandalei , and A. salina in the presence of induced K. mikimotoi that had previously been exposed to a certain grazer were lower than their counterparts caused by fresh K. mikimotoi , suggesting that exposure to some grazers might increase the toxicity of K. mikimotoi . The chemical response and associated increased resistance to further grazing suggested that K. mikimotoi could produce deterrents to protect against grazing by zooplankton and that the substances responsible might be hemolytic toxins and EPA .

iTRAQ analysis was used to map the proteomes of two Brassica parachinensis cultivars that differed in dibutyl phthalate (DBP) accumulation. A total of 5699 proteins were identified to obtain 152 differentially regulated proteins, of which 64 and 48 were specific to a high- and a low-DBP-accumulation cultivar, respectively. Genotype-specific biological processes were involved in coping with DBP stress, accounting for the variation in DBP tolerance and accumulation. Formation of high DBP accumulation in B. parachinensis might attribute to the more effective regulation of protein expression in physiology and metabolism, including (a) enhanced cell wall biosynthesis and modification, (b) better maintenance of photosynthesis and energy balance, (c) greatly improved total capacity for antioxidation and detoxification, and (d) enhanced cellular transport and signal transduction. Our novel findings contribute to a global picture of DBP-induced alterations of protein profiles in crops and provide valuable information for the development of molecular-assisted breeds of low-accumulation cultivars.

Members of the Alexandrium tamarense species complex are some of the most important toxigenic dinoflagellates and are also widely distributed along the coast of China. A. tamarense and another well-known toxic raphidophycean alga, Chattonella marina, are usually found in the same sea areas, sometimes at the same place and time. In this study, under laboratory co-culture conditions, we found that most of the 15 A. tamarense strains from the South China Sea and the East China Sea had significant inhibition on the growth of C. marina, while most of the A. tamarense strains were inhibited to various extents by C. marina. These results suggest that there is a complex reciprocal inhibitory effect between A. tamarense and C. marina, which might be caused by their allelopathic potency, the intrinsic growth rate of the algal species and the sensitivity of the target alga to the allelochemicals, etc. However, no strict correlations were observed between the allelopathic actions and the geographical distribution. The allelopathic potency observed in co-culture did not correlate with the hemolytic activity of the extracellular toxins obtained by the solvent extraction method (p > 0.05) but did correlate with the hemolytic activity obtained by the dialysis method (p < 0.01). These results indicate that various strains of A. tamarense could produce diverse hemolytic substances with different compositions and properties, which might be responsible for the variability in A. tamarense allelopathic action.

P-glycoprotein (P-gp), as an ATP-binding cassette transporter, can transport a variety of substrates across the cell membrane in human and animals, even in aquatic animals. Multixenobiotic resistance phenomenon (MXR) related to the P-gp has been identified and characterized in several aquatic organisms, however, the nature of this transporter and the structural basis for the resistance are still poorly understood. In this study, to provide an insight into the roles of P-gp in resistance of bivalve against environmental pollution and toxins, complete cDNA of P-gp gene in Crassostrea ariakensis was cloned and analyzed. The accumulation of okadaic acid (OA), a main component of diarrhetic shellfish poisoning (DSP) toxins, and expression of P-gp in gills, digestive glands and mantle of C. ariakensis, were detected upon exposure to Prorocentrum lima, a known producer of DSP toxins. The complete sequence of oyster P-gp showed a high identity to MDR/P-gp/ABCB proteins from other species and contained some classical features of ABCB transport proteins. Upon exposure to P. lima for 72 h, the OA level increased 2.5-fold in gills and 6.4-fold in digestive glands of C. ariakensis. Meanwhile, the expression of P-gp mRNA increased 2.4-fold in gills and decreased slightly in digestive glands. No significant difference in P-gp protein expression was found by western blot in all of the tissues analyzed in P. lima-exposed oysters. Taking all of our results into account, we speculate that P-gp likely plays a role in the response to DSP toxins in C. ariakensis.

Vigna radiata (mung bean) is an important crop plant and is a major protein source in developing countries. Mung bean 8S globulins constitute nearly 90% of total seed storage protein and consist of three subunits designated as 8SGα, 8SGα′ and 8SGβ. The 5′-flanking sequences of 8SGα′ has been reported to confer high expression in transgenic Arabidopsis seeds. In this study, a 472-bp 5′-flanking sequence of 8SGα was identified by genome walking. Computational analysis subsequently revealed the presence of numerous putative seed-specific cis-elements within. The 8SGα promoter was then fused to the gene encoding β-glucuronidase (GUS) to create a reporter construct for Arabidopsis thaliana transformation. The spatial and temporal expression of 8SGα∷GUS, as investigated using GUS histochemical assays, showed GUS expression exclusively in transgenic Arabidopsis seeds. Quantitative GUS assays revealed that the 8SGα promoter showed 2- to 4-fold higher activity than the Cauliflower Mosaic Virus (CaMV) 35S promoter. This study has identified a seed-specific promoter of high promoter strength, which is potentially useful for directing foreign protein expression in seed bioreactors.

To investigate the prognostic values of clinical factors 72 h within traumatic cervical spinal cord injury (TCSCI). Data were extracted from the medical materials of 57 TCSCI cases. AIS was used as the outcome measure and divided into dichotomous variables by two methods, i.e. "complete(AIS = A)/incomplete(AIS ≠ A) SCI" and "motor complete(AIS = A or B)/incomplete(AIS ≠ A and B) SCI". Relationships between evaluated factors and outcomes were investigated by univariate and multivariate methods. MRI Cord transection (MCT) cases, most significantly related to complete SCIs by univariate analysis (P = 0.006), all showed complete SCIs when discharged, which makes it unsuitable for logistic regression. With MCT cases removed, univariate analysis was conducted again, then logistic regression. At last, only C5 spine injury (P = 0.024, OR = 0.241) was related to complete SCI. Cases with compression flexion injury mechanism (CFIM), most significantly related to motor complete SCIs by univariate analysis (P = 0.001), was also unsuitable for logistic regression for the same reason. At last, C3 spine injury (P = 0.033, OR = 0.068) and high energy injury (P = 0.033, OR = 14.763) were related to motor complete SCIs with CFIM cases removed. The results show that MCT and C5 spine injury are good predictors for complete/incomplete SCIs. CFIM, C3 spine injury and high energy injury are good predictors for motor complete/incomplete SCIs.

Karenia mikimotoi is an important toxin-producing dinoflagellate, frequently forming blooms along the coast of China. It has been shown that K. mikimotoi has allelopathic effects on other organisms, which benefited it over other microalgal species in competition. However, the underlying allelopathy mechanisms remain largely unclear. Thalassiosira pseudonana, a worldwide-distributed planktonic diatom, is extensively used as a model in diatom physiology studies. Here, we investigated the responses of T. pseudonana to K. mikimotoi allelopathy when they were co-cultured under laboratory condition. We found that there were reciprocal inhibitory effects between K. mikimotoi and T. pseudonana, and the cell-free filtrate of K. mikimotoi also deeply suppressed the growth of T. pseudonana, corroborating that K. mikimotoi allelopathy mainly accounted for the inhibition of K. mikimotoi against T. pseudonana. After exposed to K. mikimotoi allelopathy, the photosynthetic efficiency, contents of neutral lipid and malondialdehyde (MDA), as well as superoxide dismutase (SOD) activity in T. pseudonana were significantly changed. Meanwhile, the expression of genes involved in photosynthesis, oxidative phosphorylation, detoxifying system and nutrients uptake including PsbO, chlorophyll synthase (ChlG), risp1, ferredoxin-NADP+ reductase (PetH), ABCB1, nitrate transporters 1 (NRT1), phosphate transporter (PHT), alkaline phosphatase (ALP) and ascorbate peroxidase (APX) in T. pseudonana dramatically altered. These results suggested that K. mikimotoi could highly affect the efficiency of photosynthesis and energy metabolism of T. pseudonana, and also inhibit the nutrients uptake and assimilation. Our findings might provide insight information for the K. mikimotoi allelopathy.

To investigate the long-term (> 7 years) clinical outcomes of percutaneous endoscopic lumbar discectomy for lumbar degenerative disease to address postoperative problems including postoperative dysesthesia (POD), residual back pain and segmental instability.Inclusion and exclusion criteria were established. All patients who met the above criteria were treated by PELD using the transforaminal approach. Limited discectomy was performed to preserve the disc material in the intervertebral space as much as possible. The Oswestry Disability Index (ODI), Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS) score for back pain (VAS-B) and leg pain (VAS-L) and Modified MacNab's criterion were used for clinical evaluation. Radiographic parameters including height of intervertebral disc and segmental instability were also evaluated.Forty-two patients (24 men and 18 women) who met our inclusion and exclusion criteria were included in our study. The average follow-up period was 95.71±5.63 months (ranging from 87 to 105 months). There were no neurological complications associated with the operation. POD was found in 14.29% of patients, while only 2 patients (4.76%) complained of mild dysesthesia at final follow-up. Two patients (4.76%) required revision surgery during the follow-up period. The final follow-up ODI, JOA score, VAS-B and VAS-L were significantly better than preoperative values. The average disc-height ratio was 84.52±5.66% of the preoperative disc height. No instability at the operation level was noted at final follow-up.Our study showed that PELD using the transforaminal approach can provide favorable results after a long-term follow-up period. POD is a common complication at initial prognosis. Limited discectomy can preserve the disc height well and minimize the risk of residual back pain.

With the development of construction industry in China, the demand for construction concrete materials has increased in recent years, and the urbanization process strongly recommends the phenomenon that the natural recovery rate is less than the utilization rate while the river sand is overexploited. Marine resources are relatively abundant. The existing sea sand has naturally become a substitute for river sand. In this paper,to compared with the cement mortar formed by desalination sea sand and ordinary river sand mortar, we studied its physical properties, working performance tests and durability performance.Meanwhile, the basic performance and durability properties of mortar prepared by modified sea sand mixed with fly ash were studied.The results showed that for desalinated sea sand cement mortar increased chemical ions corrosion resistance.The setting time shortened,the mechanical properties of specimens decreased.After adding fly ash as modification experiments,the working properties and durability significantly improved.The mechanical properties of modified sea sand cement mortar enhanced.Then the micro-structure of the modified sea sand cement mortar was observed through SEM so as to further explain the reasons for the influence of performance changes and provided reference for future research on sea sand concrete.

Abstract The effects of five natural products on the growth of three harmful algae species including C hattonella marina H ara et C hihara, A lexandrium tamarense B alech and K arenia mikimotoi ( M iyake &amp; K ominami ex O da) G . H ansen &amp; Ø . M oestrup were observed. Four products including ε ‐polylysine, betaine, stachydrine and berberine exhibited selectively inhibitory effects against the three algae. However, the other product chitosan had no obvious inhibition against the above algae. Berberine and ε ‐polylysine exhibited relatively higher inhibitory capability against C . marina , and betaine had the highest inhibitory effect against A . tamarense . While only berberine could effectively inhibit the growth of K . mikimotoi with LC 50 , 120 at 3.1 mg/L. The fast inhibitory effect against K . mikimotoi and environmental safety of berberine suggested that it might be a potential algaecide against K . mikimotoi .

Green tides have occurred in Qingdao coast in China for seven consecutive years from 2007 to 2013. To provide information on the genetic structure of these blooms, 210 free-floating green algae samples isolated from the green tide in Qingdao coast on June 19, 2013 were identified based on the ITS, rbcL and 5S sequence, and genetic diversity was investigated by microsatellite markers. According to ITS, rbcL and 5S sequence, all the 210 samples belonged to Ulva prolifera. Nei's genetic diversity and Shannon index estimated using eight microsatellite markers indicated that the genetic diversity of U. prolifera population within Qingdao's green bloom in 2013 was low. Taking into account previous reports about life history and physiology of U. prolifera, we proposed that the limited origin area of the free-floating biomass and asexual reproduction of U. prolifera might be responsible for the lower diversity of free floating U. prolifera.

Prorocentrum lima is a typical benthic toxic dinoflagellate, which can produce phycotoxins such as okadaic acid (OA). In this study, we identified three ABC transporter genes (ABCB1, ABCC1 and ABCG2) and characterized their expression patterns, as well as OA production under different environmental conditions in P. lima. We found that the three ABC transporters all showed high identity with related ABC proteins from other species, and contained classical features of ABC transport proteins. Among them, ABCG2 was a half size transporter. The three ABC transporter genes displayed various expression profiles under different conditions. The high concentration of Cu2+ could up-regulate ABCB1, ABCC1 and ABCG2 transcripts in P. lima, suggesting the potential defensive role of ABC transporters against metal ions in surrounding waters. Cu2+, in some concentration, could induce OA production; meanwhile, tributyltin inhibited OA accumulation. The grazer Artemia salina could induce OA production, and P. lima displayed some toxicity to the grazer, indicating the possibility of OA as an anti-grazing chemical. Collectively, our results revealed intriguing data about OA production and the expression patterns of three ABC transporter genes. However, we could not find any significant correlation between OA production and expression pattern of the three ABC transporters in P. lima. Our results might provide new molecular insights on the defensive responses of P. lima to the surrounding environment.

Okadaic acid (OA) is an important liposoluble shellfish toxin distributed worldwide, and is mainly responsible for diarrheic shellfish poisoning in human beings. It has a variety of toxicities, including cytotoxicity, embryonic toxicity, neurotoxicity, and even genotoxicity. However, there is no direct evidence of its developmental toxicity in human offspring. In this study, using the chicken (Gallus gallus) embryo as the animal model, we investigated the effects of OA exposure on neurogenesis and the incidence of neural tube defects (NTDs). We found that OA exposure could cause NTDs and inhibit the neuronal differentiation. Immunofluorescent staining of pHI3 and c-Caspase3 demonstrated that OA exposure could promote cell proliferation and inhibit cell apoptosis on the developing neural tube. Besides, the down-regulation of Nrf2 and increase in reactive oxygen species (ROS) content and superoxide dismutase (SOD) activity in the OA-exposed chicken embryos indicated that OA could result in oxidative stress in early chick embryos, which might enhance the risk of the subsequent NTDs. The inhibition of bone morphogenetic protein 4 (BMP4) and Sonic hedgehog (Shh) expression in the dorsal neural tube suggested that OA could also affect the formation of dorsolateral hinge points, which might ultimately hinder the closure of the neural tube. Transcriptome and qPCR analysis showed the expression of lipopolysaccharide-binding protein (LBP), transcription factor AP-1 (JUN), proto-oncogene protein c-fos (FOS), and C-C motif chemokine 4 (CCL4) in the Toll-like receptor signaling pathway was significantly increased in the OA-exposed embryos, suggesting that the NTDs induced by OA might be associated with the Toll-like receptor signaling pathway. Taken together, our findings could advance the understanding of the embryo-fetal developmental toxicity of OA on human gestation.