1,720,966 research outputs found
Nanobiotechnology Workforce Training on a Shoe String Budget
No full textIn this webinar, published by the National Center for Nanotechnology Applications and Career Knowledge, Mrunalini Pattarkine from Harrisburg University discusses efforts to develop a trained workforce in nanobiotechnology. Pattarkine provides an overview of nanobiotechnology, career opportunities associated with it, and the need for a workforce trained in biotechnology skills to fill these roles. Covered are the challenges associated with promoting interest in nanobiotechnology and strategies employed by Harrisburg University, such as day-long career events and undergraduate research projects.The video recording runs 58:27 minutes in length. Also included is an audio recording and presentation slides
DNA-surfactant interactions: coupled cooperativity in ligand binding leads to duplex stabilization
No full textThe cooperative nature of interaction of cationic surfactants with short oligonucleotides leading to eventual stabilization of DNA duplexes is demonstrated. At submicellar concentrations and DNA:surfactant charge ratios of 0.2 to 0.8, the association of single chain (CTAB) and double chain (DOTAP) surfactants to oligonucleotides is initiated by electrostatic interaction of cationic ligands with polyanionic DNA that aligns the surfactant molecules on the DNA template. This is followed by binding of new surfactant ligands to the initial complex, driven cooperatively by the hydrophobic forces, leading to in situ formation of surfactant-bound and bare duplexes as separate species. These exhibit independent melting behaviour characterised by double transition in thermal UV profiles, with a higher Tm for surfactant-DNA complexes. Understanding the cooperative binding of the cationic surfactants to the DNA described here may have implications for rational design of DNA binding drugs and DNA delivery systems
Retinylidene Schiff bases in phosphatidylcholine reverse micelles: formation, protonation and stability
No full textAll-trans-N-retinylidene-n-butylamine 3 has been formed in inverted micelles of phosphatidylcholine (PC)–hexane containing varying amounts of water ([H2O]/[PC]= 0–3) and the formation, protonation and stability have been studied. The micelles have been found to catalyse the Schiff-base formation. The Schiff-base was found to be stable in the presence of structured water molecules bonded to the polar head groups of the micelles. A larger water-pool causes the decomposition of the Schiff-base. Schiff-base 3 intercalated in the inverted micelle was found to undergo protonation in the presence of 3-chloropropionic acid, the extent of which depended on the water-pool size. The results are discussed in terms of the formation, protonation and stability of retinylidene Schiff-base chromophores in rhodopsins
Abstract
No full textThis chapter covers geomicrobiology of uranium, various methods currently applied for uranium bioremediation, microbial and biochemical mechanisms underlining them, and biotechnology- and nanotechnology-based advancements for microbial remediation of uranium
ANION INDUCED BLUE TO PURPLE TRANSITION IN BACTERIORHODOPSIN
Get PDFPurple membrane (PM, λ role= presentation \u3eλmax role= presentation \u3emax 570 nm) of H. halobium on treatment with sulphuric acid changes its colour to blue (λ role= presentation \u3eλmax role= presentation \u3emax 608 nm). The purple chromophore can be regenerated from the blue chromophore by exogeneous addition of anions such as CI− role= presentation \u3e− and HPO42− role= presentation \u3e2−4. Chloride ion is found to be more effective than the dibasic phosphate ion in regenerating the purple chromophore. Nevertheless, one thing common to the anion regeneration is that both CI− role= presentation \u3e− and HPO42− role= presentation \u3e2−4 show marked pH effect. At pH 1.0 the efficiency of regeneration of the purple chromophore is greater than at pH 2.0, for the same anion concentration. Fluorescence and circular dichroic studies indicate that the proteins do not undergo drastic changes at the secondary\u27 or tertiary structure level and the native structure is preserved during this transition. However, chromophoric-site interactions between retinal and the apoprotein are affected during this colour transition. A molecular mechanism is advanced for this transition
Abstract
No full textNanotechnology has the potential to improve current technologies applied for biochemical as well as thermochemical processes for treatment and conversion of biomass to generate bioenergy in a variety of forms such as liquid biofuels, biohydrogen, biogas and electricity. These include improved materials for enzyme immobilization, materials with improved enzyme loading capacity, nanocatalysts, materials for storage of bioenergy products, materials for separation and purification of liquid biofuels, materials for improved performance of microbial fuel cells and so on. This chapter discusses in detail each of these areas. This chapter also elaborates on the applications of nanotechnology for bioenergy production, and defines the basic terms used in nanotechnology
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
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