1,721,008 research outputs found
Development of electrochemical biosensors by e-beam lithography for medical diagnostics
Full text linkIn this work the fabrication and characterization of boron-doped diamond (BDD) nanoelectrode arrays
are discussed. The use of boron-doped diamond electrodes is very attractive due to advantageous properties
including high reproducibility, stability, and robustness under extreme conditions, where conventional
electrode materials may undergo severe erosion. BDD electrodes have also proved to be very useful
because they show an extremely wide potential window in aqueous solutions without oxidation of the
electrode itself. This allows electrochemical detection, at tiny background currents, of a number of substances
that oxidize at very positive potentials, where other electrodic materials are not suitable. BDD
based NEAs were prepared using Si h100i substrates coated with a layer of Boron doped diamond as macroelectrode.
NEAs were obtained by creating an array of nanoholes by electron beam lithography (EBL) in
a thin film of polycarbonate deposited on top of the macroelectrode. This approach leads to the formation
of recessed nanoelectrodes. The parameters for using polycarbonate as a novel electron beam resist have
been optimized and successfully used for fabrication of NEAs. The most interesting properties of this
polymer for nanofabrication purposes are the high lithographic contrast, which allows the creation of
structures of dimensions less than 100 nm; chemical stability, which guarantees a long-term use in electrochemical
solutions and the possibility of functionalization with biological molecules (DNA and proteins).
NEAs have been characterized with cyclic voltammetry and have provided voltammetric signals
controlled by pure radial diffusion. The low background current of BDD added to the properties of NEAs
indicate that this system can be applied for the development of sensors with high sensitivity. Polycarbonate
surface of NEAs was successfully functionalized with small ss-DNA sequence, confirming the possibility
of exploiting these systems as diagnostic biosensors
Negative hybrid sol–gel resist as hard etching mask for pattern transfer with dry etching
No full textHigh resolution patterning of a sol-gel synthesized alumina-like negative photo-resist with low voltage EBL
No full textBoehmite filled hybrid sol–gel system as directly writable hard etching mask for pattern transfer
No full textWe discuss some preliminary results on the development of a new kind of positive tone resist whose peculiarity is an extreme dry etch resistance. This profitable property is obtained by loading and compatibilizing with ceramic nano particles a radiation sensitive sol-gel silica based hybrid organic/inorganic system. With an appropriate choice of the nano particles, the investigated approach is suitable to be adapted and optimized for achieving high selectivity in plasma etching processes of different materials. Here, we specifically demonstrate how the filling with boehmite nano particles (aluminum hydroxide, y-AIO(OH)) confers a much higher selectivity (>60) to the radiation sensitive silica based system when used for the etching of silicon, that show a selectivity <2 if unloaded. The patterning of the new resist was carried out by X-ray lithography while the dry etching tests were made with a fluorine-based chemistry
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
SU-8 bonding protocol for the fabrication of microfluidic devices dedicated to FTIR microspectroscopy of live cells
No full text10.1039/c3lc50878aLab on a Chip - Miniaturisation for Chemistry and Biology141210-218LCAH
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