1,720,973 research outputs found
APPLICATION OF RECOMBINANT TRIACYLGLYCEROL LIPASE AND CARBOXYLESTERASE ENZYMES FROM Bacillus velezensis STRAIN S3 FOR POLYESTER SURFACE MODIFICATION
Full text linkEnzymatic polyester surface modification can be performed with lipase and esterase enzymes. In this study, the polyester fabric modification utilized triacylglycerol lipase (TGA) and carboxylesterase (CES) recombinant enzymes. The effect of these treatments was observed by determining the hydrophilicity level, dye absorption level, hydroxyl group measurement, and fiber surface morphology. The results revealed an elevated hydrophilicity level in polyester fabric, followed by dye absorption improvement and carboxyl group increase. The water absorption times required by the fabric based on the results of TGA, CES, comparative lipase, and negative control treatments were 3±0.05 seconds, 3.5±0.07 seconds, 5±0.05 seconds, and 80±11.54 minutes, respectively. Dye absorption test in polyester fabric based on these groups mentioned above were 52±0.5, 58±0.5, 178±0.5, and 2968±290 seconds. The total hydroxyl group measurement in polyester fabric was observed at 30.9±0.09, 30.5±0.05, 28.6±0.09, and 3 meq/100 g. The SEM observation showed that the enzymatic hydrolysis could alter the porous structure and surface of the fibers
Direct Cloning of a Xylanase Gene from Pawan-Riau Hot Spring
Full text linkA functional gene containing an Open Reading Frame (ORF) encoding a ?-1, 4-endoxylanase glycosyl hydrolase family 11 was cloned directly using metagenomic PCR-cloning method from Pawan Hot Spring sample in Riau. The gene consisted of 642 nucleotides, encoded for 213 amino acids. The amino acid sequence analysis using BLAST showed that the gene has high homology (93%) with xylanase gene from Bacillus subtilis. The gene showed its function when it was subcloned into an expression vector and overexpressed in E. coli. The crude extract of the recombinant enzyme had activity for 170 U/ml at 50 oC. The result of this work showed that metagenomic approach was a powerful short cut method to obtain recombinant biocatalyst that was useful for industrial application. Key words: ?-1, 4-endoxylanase, metagenomic DNA, Pawan-Riau hot-sprin
INCREASING RECOMBINANT PENICILLIN G ACYLASE PRODUCTION: GENETIC, PROTEIN ENGINEERING, AND PRODUCTIVITY IMPROVEMENT
Full text linkB-lactam derived antibiotics are the most used globally for treatment against different infections caused by pathogenic bacteria and comprises 65% of the world antibiotics. Recently, penicillin G acylase (PGA) is used as biocatalyst for those B-lactam antibiotics production by which 6-aminopenicillanic acid (6-APA) or 7-aminodeacetoxycephalosporanic acid (7-ADCA) as the building blocks is produced. Commercialized PGA from native microbial resources are still limited to E. coli. Therefore, genetic engineering approach such as cloning and expression in other microbial hosts were assessed to enhance bacterial strains that produce PGA. However, such improvement could increase immature precursors accumulation and lowering the enzyme yield, activity, or stability. This review focus on the review of PGA recombinant produced by several microbial host, their expression levels, and improvement achieved by some modification such as replacement of signal peptide and promoter continued to protein engineering to utilize the enzymes in synthetizing amoxicillin rather than to hydrolyses Penicillin G
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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