1,720,955 research outputs found
Novel biobased amines
No full textThe present invention relates to a method for producing an amidoamine by reacting a triacid derivative (I) with at least one amine (A), the at least one amine (A) being selected from diethylene triamine and a diamine (II). The molar ratio of the triacid derivative (I) to the at least one amine (A) is in the range of 1 : 2 to 1 : <3. The present invention further relates to the amidoamine as such,and to the use of said amidoamine as a cross-linking agent
Use of glucosamine as shale inhibitor
No full textThe present invention is directed to a well fluid comprising at least one oligoglucosamine and/or a salt thereof and a drilling process wherein said well fluid is applied. Further, the present invention is directed to the use of oligoglucosamines and/or salts thereof in the development, exploitation and completion of underground mineral oil and natural gas deposits and in deep wells
Synthese, Modifikation und biologische Anwendung fluoreszierender Xanthenfarbstoffe
Full text linkKurzzusammenfassung Xanthenfarbstoffe, die sich vom Rhodamin- und Fluorescein-Grundgerüst ableiten, zeichnen sich durch eine intensive Fluoreszenz aus und sind daher als molekulare Sonden für bioanalytische Anwendungen und das zelluläre Imaging von großer Relevanz. In dieser Arbeit wurden Derivate von Xanthenfarbstoffen synthetisiert, die auf biologisch wichtige Metallionen ansprechen, ungewöhnliche Akkumulation und subzelluläre Verteilungen in lebenden Zellen zeigen oder Fluoreszenzsensoren für Redoxpotentiale sind. Die wichtigsten neu entwickelten Sonden und ihre Anwendungen sind hier zusammengefasst: •Fluorogene Sonde für Cu2+-Ionen Während literaturbeschriebene Cu2+ Fluoreszenzsensoren durch Fluoreszenzlöschung auf Cu2+-Ionen ansprechen, ist das dargestellte Dipicolinoylfluorescein ein seltenes Beispiel für eine fluorogene Cu2+-Sonde. Durch Cu2+ vermittelte Esterhydrolyse wird Fluorescein gebildet. Das Detektionslimit liegt bei 100 nM Cu2+. Die literaturbekannte fluorogene Sonde Diacetylfluorescein wurde für ein Screening der Esteraseaktivität von Rinderserumalbumin eingesetzt. Durch Dotierung mit Cu2+ und anderen Metallionen konnte die sehr schwache Aktivität geringfügig gesteigert werden, jedoch nicht in einem für präparative Anwendungen ausreichenden Maß. •Metallbindende Sonde Terpyridinfunktionalisierte Rhodamine reichern sich ungewöhnlich stark in lebenden Zellen an. Dies könnte auf die intrazelluläre Assoziation der Terpyridin-Einheit mit Zn2+, das proteingebunden ist, aber noch über freie Koordinationsstellen verfügt, zurückzuführen sein. Extrazelluläres Zn2+ verhindert durch die Komplexierung die Aufnahme von terpyridin-funktionalisiertem Rhodamin in die Zelle. Die zelluläre Aufnahme kann folglich durch extrazelluläres Zn2+ gesteuert werden. •Redoxsensor Während es fluoreszierende molekulare Sonden für intrazelluläre pH-Wert Messungen bereits in zahlreichen Varianten gibt, besteht ein Bedarf an Fluoreszenzsensoren für biologische Redoxpotentiale. Ein Sensor für Redoxpotentiale wurde dargestellt, indem ein Hydrochinon an einen Rhodamin-Farbstoff gekoppelt wurde. Dem Design des Redoxsensors liegt zugrunde, dass Chinone oft gute Fluoreszenzlöscher sind, während die reduzierte Hydrochinonform die Fluoreszenz meist wenig beeinflusst. Die Fluoreszenz des Rodoxsensors wird reversibel gelöscht, wenn die Hydrochinonkomponente durch H2O2 zur Chinonform oxidiert wird. Mit Thiolen kann die Hydrochinonform und die Fluoreszenz regeneriert werden
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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