1,720,979 research outputs found
Development of a handheld fiber-optic probe-based raman imaging instrumentation: raman chemlighter
Full text linkRaman systems based on handheld fiber-optic probes offer advantages in terms of smaller sizes and easier access to the measurement sites, which are favorable for biomedical and clinical applications in the complex environment. However, there are several common drawbacks of applying probes for many applications: (1) The fixed working distance requires the user to maintain a certain working distance to acquire higher Raman signals; (2) The single-point-measurement ability restricts realizing a mapping or scanning procedure; (3) Lack of real-time data processing and a straightforward co-registering method to link the Raman information with the respective measurement position. The thesis proposed and experimentally demonstrated various approaches to overcome these drawbacks. A handheld fiber-optic Raman probe with an autofocus unit was presented to overcome the problem arising from using fixed-focus lenses, by using a liquid lens as the objective lens, which allows dynamical adjustment of the focal length of the probe. An implementation of a computer vision-based positional tracking to co-register the regular Raman spectroscopic measurements with the spatial location enables fast recording of a Raman image from a large tissue sample by combining positional tracking of the laser spot through brightfield images. The visualization of the Raman image has been extended to augmented and mixed reality and combined with a 3D reconstruction method and projector-based visualization to offer an intuitive and easily understandable way of presenting the Raman image. All these advances are substantial and highly beneficial to further drive the clinical translation of Raman spectroscopy as potential image-guided instrumentation
Raman-Differenzspektroskopie mit zwei verschiedenen Anregungswellenlängen zur untergrundfreien und bildgebenden Untersuchung von biologischen Proben
Full text linkMit Hilfe der Raman-Spektroskopie ist es möglich, Informationen über die chemische Zusammensetzung einer Probe zu erhalten, ohne diese zu beschädigen oder im Vorfeld zu markieren. Daher findet die Raman-Spektroskopie immer häufiger Anwendung für die Untersuchung komplexer biologischer Proben wie Zellen, Bakterien und Gewebe. Dabei kann es zur Anregung von Autofluoreszenz in niedrig konzentrierten Substanzen und Chromophoren wie Hämabbauprodukten kommen, welche einen hohen spektralen Untergrund im Raman-Spektrum erzeugt und so zu einer Maskierung der Raman-Banden führen kann. Der Schwerpunkt dieser Dissertation ist die Verwendung der instrumentellen Basislinienkorrekturmethode SERDS (engl. shifted excitation Raman difference spectroscopy) für die Untersuchung von biologischen Proben. Bei dieser Methode werden am gleichen Messpunkt zwei Raman-Spektren mit zwei verschiedenen Anregungswellenlängen gemessen und diese voneinander subtrahiert. Das daraus resultierende SERDS-Spektrum ist idealerweise ein untergrundfreies Differenzspektrum, das der ersten Ableitung eines Raman-Spektrums sehr ähnlich ist. Ziel dieser Dissertation war die Evaluierung und Optimierung der SERDS-Methode und der SERDS-Bildgebung an biologischen Proben. Um die Aufnahme eines SERDS-Bildes zu beschleunigen und den Untergrund zu minimieren, wurde erstmalig die Weitfeld-SERDS-Bildgebung mittels der interlaced nod and shuffle Technik, eine Technik aus der Astrophysik, unter Verwendung sehr schnell wechselnder Laserwellenlängen verwendet
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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