463 research outputs found
sj-pdf-1-imj-10.1177_10815589231167359 – Supplemental material for Development and validation of a scoring system incorporating tumor growth pattern and perineural invasion for risk stratification in colorectal cancer
No full textSupplemental material, sj-pdf-1-imj-10.1177_10815589231167359 for Development and validation of a scoring system incorporating tumor growth pattern and perineural invasion for risk stratification in colorectal cancer by Yulin Liu, Yiting Wang, Su Yao, Changhong Liang, Qian Li, Zaiyi Liu, Yaxi Zhu, Yanfen Cui and Ke Zhao in Journal of Investigative Medicine</p
Transcriptomic analysis of Synechocystis sp PCC6803 under low-temperature stress
No full textIn this study, cDNA microarrays were developed from 3569 mRNA reads to analyze the expression profiles of the transcriptomes of Synechocystis sp. PCC6803 under low temperature (LT) stress. Among the genes on the cDNA microarrays, 899 LT-affected genes exhibited a 1.5-fold (or greater) difference in expression compared with the genes from normal unstressed Synechocystis sp. PCC6803. Of the differentially expressed genes, 353 were up-regulated and 246 were down-regulated. The results showed that genes involved in photosynthesis were activated at LT (10A degrees C), including genes for photosystem I, photosystem II, photosynthetic electron transport, and cytochrome b6/f complex. Moreover, desB, one of four genes that encode the fatty acid desaturases, was also induced by LT. However, the LT conditions to some degree enhanced the transcription of some genes. In addition, LT (10A degrees C) may reduce cellular motility by regulating the transcription of spkA (sll1575), a serine/threonine protein kinase. The results reported in this study may contribute to a better understanding of the responses of the Synechocystis cell to LT, including pathways involved in photosynthesis and repair.In this study, cDNA microarrays were developed from 3569 mRNA reads to analyze the expression profiles of the transcriptomes of Synechocystis sp. PCC6803 under low temperature (LT) stress. Among the genes on the cDNA microarrays, 899 LT-affected genes exhibited a 1.5-fold (or greater) difference in expression compared with the genes from normal unstressed Synechocystis sp. PCC6803. Of the differentially expressed genes, 353 were up-regulated and 246 were down-regulated. The results showed that genes involved in photosynthesis were activated at LT (10A degrees C), including genes for photosystem I, photosystem II, photosynthetic electron transport, and cytochrome b6/f complex. Moreover, desB, one of four genes that encode the fatty acid desaturases, was also induced by LT. However, the LT conditions to some degree enhanced the transcription of some genes. In addition, LT (10A degrees C) may reduce cellular motility by regulating the transcription of spkA (sll1575), a serine/threonine protein kinase. The results reported in this study may contribute to a better understanding of the responses of the Synechocystis cell to LT, including pathways involved in photosynthesis and repair
Cloning and characterization of a novel diacylglycerol acyltransferase from the diatom Phaeodactylum tricornutum
No full textIn this study, a cDNA encoding a novel acyl-CoA:diacylglycerol acyltransferase (DGAT)-like protein is identified and isolated from the diatom microalga Phaeodactylum tricornutum (PtDGAT3). Analysis of the sequence reveals that ptDGAT3 cDNA encodes a protein of 504 amino acids with a molecular mass of 64.5 KDa. The putative ptDGAT3 protein has two catalytic domains: a wax ester synthase-like acyl-CoA acyltransferase domain and a bacteria-specific acyltransferase domain, which shows higher similarity to the DGAT3 of Acinetobacter calcoaceticus than reported DGAT1 or DGAT2 from high plants or algae. Its activity was confirmed by heterologous expression of PtDGAT3 in a neutral lipid-deficient quadruple mutant yeast Saccharomyces cerevisiae H1246. The recombinant yeast restored the formation of a lipid body and displayed a preference to the incorporation of unsaturated C-18 fatty acids into triacyglycerol (TAG). This is the first characterized algal DGAT3 gene, giving further evidence to the occurrence of a DGAT3-mediated TAG biosynthesis pathway
Characteristics of the Soil and Vegetation along the Yulin–Jingbian Desert Expressway in China
No full textTransportation infrastructure dramatically affects ecological processes. However, the environmental assessment process does not often consider how transportation impacts biodiversity, especially in ecologically fragile areas. The aim of this study was to assess the impacts of the Yulin–Jingbian expressway on vegetative diversity and to discuss the reason for the differences in soil-moisture distribution and vegetation diversity along the expressway. Samples were collected from 60 quadrats, along 6 transects. The α diversity indices and soil-moisture content calculated for each layer were used to represent habitat heterogeneity within a quadrat. A total of 49 species representing 39 genera and 16 families were recorded. Perennial herbs (42.9%) and annual herbs (36.7%) were the dominant life form. Species richness, diversity, and evenness indices of the vegetation varied with the distance between sampling points along the expressway. The vegetation with high diversity and evenness were near the expressway and areas with low diversity were farther from the expressway. The soil-moisture content in the 0–20 cm soil layer was a driving factor for the α diversity indices, and soil-moisture content below 20 cm played an inhibitory role on the α diversity indices. The greatest impact of the expressway on vegetation diversity was its effect on surface runoff and the distribution of plant root systems in the top layer of soil
Chloroplast Transformation of Platymonas (Tetraselmis) subcordiformis with the bar Gene as Selectable Marker
No full textThe objective of this research was to establish a chloroplast transformation technique for Platymonas (Tetraselmis) subcordiformis. Employing the gfp gene as a reporter and the bar gene as a selectable marker, transformation vectors of P. subcordiformis chloroplast were constructed with endogenous fragments rrn16S-trnl (left) and trnA-rrn23S (right) as a recombination site of the chloroplast genome. The plasmids were transferred into P. subcordiformis via particle bombardment. Confocal laser scanning microscopy indicated that the green fluorescence protein was localized in the chloroplast of P. subcordiformis, confirming the activity of the Chlamydomonas reinhardtii promoter. Cells transformed with the bar gene were selected using the herbicide Basta. Resistant colonies were analyzed by PCR and Southern blotting, and the results indicated that the bar gene was successfully integrated into the chloroplast genome via homologous recombination. The technique will improve genetic engineering of this alga
Molecular analysis of green-tide-forming macroalgae in the Yellow Sea
No full textIn the summer of 2008, free-floating green algae bloomed in the Yellow Sea. Samples were collected in a wide area (119 degrees 32'-122 degrees 00'E, 32 degrees 25'-36 degrees 49'N). We calculated the sequence divergences of nuclear ITS, chloroplast rbcL, and psbA data of free-floating samples collected from the Yellow Sea and Ulvaceae from Europe and Japan. In the ITS sequence, 19 out of the 21 Yellow Sea samples of 2008 were identical to those of a sample taken at Qingdao in 2007. A low divergence (0.2%) was found in remaining two samples. Similar evidence was shown by pairwise distances of rbcL and psbA gene sequence data, implying the uniformity of the Yellow Sea blooms in 2007 and 2008. The ITS sequence of the Yellow Sea samples differed 8.1-10.8% from free-floating Enteromorpha or Ulva reported worldwide. ITS-based molecular phylogenetic results and rbcL sequence data grouped the free-floating alga in the Yellow Sea into one clade with Enteromorpha procera, Enteromorpha linza and Enteromorpha prolifera. Furthermore, both morphological characteristics and ribotype network of the ITS sequences imply that the blooming algae in 2007 and 2008 were E. prolifera. The haplotypes of the Yellow Sea free-floating E. prolifera are closely related to those from the Japanese coast but less to European and American algae. (C) 2010 Elsevier B.V. All rights reserved.In the summer of 2008, free-floating green algae bloomed in the Yellow Sea. Samples were collected in a wide area (119 degrees 32'-122 degrees 00'E, 32 degrees 25'-36 degrees 49'N). We calculated the sequence divergences of nuclear ITS, chloroplast rbcL, and psbA data of free-floating samples collected from the Yellow Sea and Ulvaceae from Europe and Japan. In the ITS sequence, 19 out of the 21 Yellow Sea samples of 2008 were identical to those of a sample taken at Qingdao in 2007. A low divergence (0.2%) was found in remaining two samples. Similar evidence was shown by pairwise distances of rbcL and psbA gene sequence data, implying the uniformity of the Yellow Sea blooms in 2007 and 2008. The ITS sequence of the Yellow Sea samples differed 8.1-10.8% from free-floating Enteromorpha or Ulva reported worldwide. ITS-based molecular phylogenetic results and rbcL sequence data grouped the free-floating alga in the Yellow Sea into one clade with Enteromorpha procera, Enteromorpha linza and Enteromorpha prolifera. Furthermore, both morphological characteristics and ribotype network of the ITS sequences imply that the blooming algae in 2007 and 2008 were E. prolifera. The haplotypes of the Yellow Sea free-floating E. prolifera are closely related to those from the Japanese coast but less to European and American algae. (C) 2010 Elsevier B.V. All rights reserved
Extraction of biomolecules from microalgae
No full textMicroalgae offer great potential for producing several valuable biomolecules due to their fast growth rate, and the feasibility for large-scale production on waste resources. As the global demand for microalgae grows, several technical barriers need to be addressed before the practical implementation of microalgae-based process development becomes a reality. To this end, this chapter reviews both the vast potential of biomolecules available from microalgae and also various cell disruption and extraction methods aimed at optimizing the extraction efficiency of such molecules. Of particular importance are nutraceuticals and antioxidants, which have a growing market in the health foods sector. Moreover, the conversion of three major microalgae components (lipids, proteins, and carbohydrates) into different types of biofuels is discussed extensively. Finally, future research directions are presented.NSER
Catalytic conversion of glycerol into hydrogen and value-added chemicals: Recent research advances
No full textIn recent decades, the use of biomass as alternative resources to produce renewable and sustainable biofuels such as biodiesel has gained attention given the situation of the progressive exhaustion of easily accessible fossil fuels, increasing environmental concerns, and a dramatically growing global population. The conventional transesterification of edible, nonedible, or waste cooking oils to produce biodiesel is always accompanied by the formation of glycerol as the by-product. Undeniably, it is essential to economically use this by-product to produce a range of valuable fuels and chemicals to ensure the sustainability of the transesterification process. Therefore, recently, glycerol has been used as a feedstock for the production of value-added H2 and chemicals. In this review, the recent advances in the catalytic conversion of glycerol to H2 and high-value chemicals are thoroughly discussed. Specifically, the activity, stability, and recyclability of the catalysts used in the steam reforming of glycerol for H2 production are covered. In addition, the behavior and performance of heterogeneous catalysts in terms of the roles of active metal and support toward the formation of acrolein, lactic acid, 1,3-propanediol, and 1,2-propanediol from glycerol are reviewed. Recommendations for future research and main conclusions are provided. Overall, this review offers guidance and directions for the sufficient and economical utilization of glycerol to generate fuels and high value chemicals, which will ultimately benefit industry, environment, and economy.Natural Sciences and Engineering Research Council of Canada (NSERC)University of Prince Edward Islan
Current trends in biochar application for catalytic conversion of biomass to biofuels
No full textUnder the circumstances of serious environmental challenges and energy crises, it is of utmost importance to produce fuels and chemicals from renewable biomass and organic wastes. Biochar as a bioproduct from thermochemical conversion of biomass has attracted exponential research interest in recent years due to the abundance of its precursor (biomass resources) and its adaptability in different chemical reaction systems. Undoubtedly, it is essential to attain an in-depth understanding of the physiochemical properties and functionalization of biochar catalysts to further improve their catalytic activity, selectivity and stability in the reactions. However, until now, only a few reports are accessible on the use of biochar as a catalytic support material and/or a standalone catalyst in thermochemical biomass conversion to produce high-quality biofuels. Thus, the key objective of this review article is to summarize and discuss the latest progress in biochar production, modification, activation and functionalization by understanding its physical chemistry, composition and application in catalytic processes. This review article provides insights into the thermochemical and hydrothermal production of biochar as well as the engineering and process optimization aspects for value-added biofuel production and decarbonization.Natural Sciences and Engineering Research Council of Canada (NSERC)University of Prince Edward Island (UPEI
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