1,720,958 research outputs found
Development of Robust Biofunctional Interfaces for Applications in Selfcleaning Surfaces, Lab-Ona-Chip Systems, and Diagnostics
No full textBiofunctional interfaces capable of anchoring biomolecules and nanoparticles of interest onto a platform are the key components of many biomedical assays, clinical pathologies, as well as antibacterial and antiviral surfaces. In an ideal biofunctional surface, bio-entities and particles are covalently immobilized on a substrate in order to provide robustness and long-term stability. Nonetheless, most of the reported covalent immobilization strategies incorporate complex wet-chemical steps and long incubation times hindering their implementation for mass production and commercialization. Another essential factor in the biointerface preparation, specially with regard to biosensors and diagnostic applications, is utilization of an efficient and durable blocking agent that can inhibit non-specific adsorption of biomolecules thereby enhancing the sensitivity of sensors by diminishing the level of background noise. Many of the commonly used blocking agents lack proper prevention of non-specific adsorption in complex fluids. In addition, most of these agents are physically attached to surfaces making them unreliable for long-term usage in harsh environments (i.e. where shear stresses above 50 dyn/cm2 or strong washing buffers are involved).
This thesis presents novel and versatile strategies to covalently immobilize nanoparticles and biomolecules on substrates. The new surface coating techniques are first implemented for robust attachment of TiO2 nanoparticles onto ceramic tiles providing self-cleaning properties. Further, we utilize similar strategies to covalently immobilize proteins and culture cells in microfluidic channels either as a full surface coating or as micropatterns of interest. The new strategies allow us to obtain adhesion of ~ 400 cells/mm2 in microfluidic channels after only 1-day incubation, which is not achievable by the conventional methods. Moreover, we show the possibility of covalently micropatterning of biomolecules on lubricant-infused surfaces (LISs) so as to attain a new class of biofunctional LISs. By integration of these surfaces into a biosensing platform, we are able to detect interleukin 6 (IL-6) in a complex biofluid of human whole plasma with a limit of detection (LOD) of 0.5 pg.mL-1. This LOD is significantly lower than the smallest reported IL-6 LOD in plasma, 23 pg mL-1, using a complex electrochemical system. The higher sensitivity of our developed biosensor can be attributed to the distinguish capability of biofunctional LISs in preventing non-specific adhesion of biomolecules compared to other blocking agents.ThesisDoctor of Philosophy (PhD)The key goal of this thesis is to provide new strategies for preparation of robust and durable biointerfaces that could be employed for many biomedical devices such as self-cleaning coatings, microfluidics, point-of-care diagnostics, biomedical assays, and biosensors in order to enhance their efficiency, sensitivity, and precision. The introduced surface biofunctionalization methods are straightforward to use and do not require multiple wet-chemistry steps and incubation times, making them suitable for mass production and high throughput demands. Moreover, the introduced surface coating strategies allow for creation of antibody/protein micro-patterns covalently bound onto a biomolecule-repellent surface. The repellent property of the surfaces is resulted from infusion of an FDA-approved lubricant into the surface of a chemically modified substrate. While the surface repellency can effectively prevent non-specific adhesion of biomolecules, the patterned antibodies can locally capture the desired analyte, making them a great candidate for biosensing
A comparative study of occupant thermal modeling
Get PDFIn North America, the ventilation system in indoor environments have been almost exclusively associated with the use of conventional ceiling air distribution systems, where the air is moved via ducts through ceiling diffusers. However, in the past years there has been a growing interest in the application of localized ventilation systems for which numerous studies have been conducted looking at different aspects such as enhanced thermal comfort, improved indoor air quality and lower energy consumption. It has also been determined that a typical localized ventilation system creates a non-uniform thermal environment, which might cause thermal discomfort due to excessive vertical temperature difference, draft, and asymmetric thermal conditions. As an alternative to the experimental measurments, the Computational Fluid Dynamics (CFD) methods have been used to predict the airflow field around the occupant. The correct prediction of the flow field is dependent upon the proper modeling of the occupant body since the actual shape of human body is complicated and its heat distribution is known to be non-uniform. However, past CFD studies on the subject were mainly performed by modeling the occupant as a block with uniform heat distribution, in order to simplify the problem and decrease the computational cost. In the present study, commercially available CFD software, Airpak from Fluent Inc., is used to simulate the occupant body by using a variety of modeling techniques in order to quantify the impact of occupant modeling assumptions on the bouyancy and inertia in induced flow field
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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
