1,720,963 research outputs found
Characterisation of the signal to noise ratio of 2-photon microscopes
No full textData related to the paper: Characterisation of the signal to noise ratio of 2-photon microscopes by Radek Macháň, Shau Poh Chong, Khee Leong Lee & Peter Törö
Aminoazaphtalocyanine peripheral substitution effect on J-dimer formation
No full textCharles University, Faculty of Pharmacy in Hradec Kralove Department: Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Author: Mgr. Radek Machan Supervisor: prof. PharmDr. Petr Zimčík, Ph.D. Rigorosum thesis: Aminoazaphtalocyanine peripheral substitution effect on J-dimer formation Azaphthalocyanines (AzaPcs) are classified as subgroup of phthalocyanine family, which are planar synthetic macromolecules derived from naturally occurring porphyrins. AzaPcs are aza-analogues of phthalocyanines, where benzenes are isosterically replaced by nitrogen heterocycles (pyrazine, pyridine or pyridazine). Due to the extensive system of conjugated double bonds, AzaPcs exhibit interesting photophysical properties, for which they are commonly used as industrial dyes, photosensitisers in photodynamic therapy, fluorescent sensors, fluorescence quenchers etc. Octakis(dialkylamino) substituted tetrapyrazinoporphyrazines (TPyzPzs), which belong to the AzaPcs family, can be used as effective fluorescence quenchers due to their ability to relax from excited state by intramolecular charge transfer (ICT) that leads to zero intrinsic fluorescence. This thesis deals with the preparation and subsequent study of the properties of symmetric TPyzPzs. Above all, the ability of TPyzPzs to form aggregates of the..
Aminoazaphtalocyanine peripheral substitution effect on J-dimer formation
Full text linkCharles University, Faculty of Pharmacy in Hradec Kralove Department: Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Author: Mgr. Radek Machan Supervisor: prof. PharmDr. Petr Zimčík, Ph.D. Rigorosum thesis: Aminoazaphtalocyanine peripheral substitution effect on J-dimer formation Azaphthalocyanines (AzaPcs) are classified as subgroup of phthalocyanine family, which are planar synthetic macromolecules derived from naturally occurring porphyrins. AzaPcs are aza-analogues of phthalocyanines, where benzenes are isosterically replaced by nitrogen heterocycles (pyrazine, pyridine or pyridazine). Due to the extensive system of conjugated double bonds, AzaPcs exhibit interesting photophysical properties, for which they are commonly used as industrial dyes, photosensitisers in photodynamic therapy, fluorescent sensors, fluorescence quenchers etc. Octakis(dialkylamino) substituted tetrapyrazinoporphyrazines (TPyzPzs), which belong to the AzaPcs family, can be used as effective fluorescence quenchers due to their ability to relax from excited state by intramolecular charge transfer (ICT) that leads to zero intrinsic fluorescence. This thesis deals with the preparation and subsequent study of the properties of symmetric TPyzPzs. Above all, the ability of TPyzPzs to form aggregates of the...Univerzita Karlova, Farmaceutická fakulta v Hradci Králové Katedra: Katedra farmaceutické chemie a farmaceutické analýzy Kandidát: Mgr. Radek Machan Školitel: prof. PharmDr. Petr Zimčík, Ph.D. Rigorózní práce: Vliv periferní substituce u aminoazaftalocyaninů na tvorbu J-dimerů Azaftalocyaniny (AzaPcs) jsou podskupinou sloučenin z rodiny ftalocyaninů, což jsou syntetické planární makromolekuly odvozené od přírodních porfyrinů. AzaPcs jsou dusíkaté analogy ftalocyaninů, kdy v molekule dochází k izosterní záměně benzenového jádra za dusíkatá heterocyklická jádra (pyrazin, pyridin či pyridazin). AzaPcs mají díky svému rozsáhlému systému konjugovaných dvojných vazeb zajímavé fotofyzikální vlastnosti, pro které jsou využívány např. jako průmyslová barviva, fotosenzitizéry používané ve fotodynamické terapii, fluorescenční senzory, zhášeče fluorescence aj. Oktakis(dialkylamino) substituované tetrapyrazinoporfyraziny (TPyzPzs), jenž patří do rodiny AzaPcs, lze použít jako účinné zhášeče fluorescence díky jejich relaxaci z excitovaného stavu pomocí intramolekulárního přenosu náboje (ICT - intramolecular charge transfer), což vede k nulové produkci vlastní fluorescence. Tato práce se zabývá přípravou a následným studiem vlastností symetrických TPyzPzs. Především je studována schopnost TPyzPzs tvořit agregáty...Katedra farmaceutické chemie a farmaceutické analýzyDepartment of Pharmaceutical Chemistry and Pharmaceutical AnalysisFaculty of Pharmacy in Hradec KrálovéFarmaceutická fakulta v Hradci Králov
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
Determination of permeability and active transport of selected butyrylcholinesterase inhibitors in vitro
Full text linkCharles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Radek Machan Supervisor: PharmDr. Lukáš Červený, Ph.D. Title of diploma thesis: Determination of permeability and active transport of selected butyrylcholinesterase inhibitors in vitro European Medicine Agency (EMA) and Food and Drug Administration agency (FDA) emphasise drug membrane permeability and drug-drug interactions on ABC transporters expressed in physiological barriers should be investigated for compounds in preclinical studies or for those already clinically used but evidence free. In this work we aimed to assess the capability of several experimental butyrylcholinesterase inhibitors that had been designed to treat dementia to permeate blood-brain barrier and to elucidate role of ATP-binding (ABC) cassette transporters in this transport. For this purpose, we employed in vitro bidirectional transport study across monolayers formed by polarized and highly differentiated Caco-2 cells. The permeability values gained from measurements were similar to values of several commonly used drugs for treatment of CNS disorders (e.g. antidepressants, antiepileptics). In addition, the compounds showed values of efflux ratio (basolateral- to-apical/apical-to-basolateral) approximately one..
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
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