1,720,965 research outputs found
3, 5-Dimethoxy-2-[(4-methoxyphenyl)diazenyl]phenol
Full text link3, 5-Dimethoxy-2-[(4-methoxyphenyl)diazenyl]phenol was synthesized by an azo-coupling reaction between 3, 5-dimethoxyphenol and 4-methoxy benzenediazonium tetrafluoroborate. The structure of newly synthesized compound was elucidated based on 1H NMR, 13C NMR, ESI-MS, UV-Vis and FT-IR
4,6-dinitro-7-(Thiazol-2-ylamino)benzo[c][1,2,5] oxadiazole 1-oxide
Full text link4,6-Dinitro-7-(thiazol-2-ylamino)benzo[c][1,2,5]oxadiazole 1-oxide was synthesized by a SN Ar reaction between 7-chloro-4,6-dinitrobenzofuroxan and 2-aminothiazole. The structure of the newly synthesized compound (45% yield) was elucidated based on1 H-NMR,13 C-NMR, NOESY-1D, ESI-MS, UV-Vis, and FT-IR techniques
1,1’,1”-(2’,4’-dinitro-[1,1’-biphenyl]-2,4, 6-triyl)tripiperidine
Full text linkThe compound 1,1’,1”-(2’,4’-dinitro-[1,1’-biphenyl]-2,4,6-triyl)tripiperidine was synthesized by SE Ar/SN Ar reaction between 1-fluoro-2,4-dinitrobenzene and 1,3,5-tris(N-piperidinyl)benzene. The structure of the newly synthesized compound was elucidated based on1 H-NMR,13 C-NMR, ESI-MS, UV-Vis and IR spectroscopy
2,9-dimethyl-11-(3- pentadecylphenoxy)dibenzo[c,f][1,2,5]dithiaphosphe pine 11-oxide
Full text link2,9-Dimethyl-11-(3-pentadecylphenoxy)dibenzo[c,f][1,2,5]dithiaphosphepine 11-oxide was synthesized (yield 50%) by a two-step procedure. The first step starts with a benzothiadiphosphole and bis-Grignard reagent, and the second step consists of adding the sodium salt of a derivative of cardanol. The structure of newly synthesized compound was elucidated based on1H-NMR,13C-NMR,31P-NMR, IR, Electron Spray Ionization (ESI)–MS, Gas Chromatography- Mass Spectroscopy (GC–MS), and Electron Spray Ionization-High Resolution Mass Spectroscopy (ESI–HRMS)
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
Synthesis of 9-hydroxystearic acid derivatives and their antiproliferative activity on HT 29 cancer cells
Full text link9-Hydroxystearic acid (9-HSA) is an endogenous cellular lipid that possesses antiproliferative and selective effects against cancer cells. A series of derivatives were synthesized in order to investigate the effect of the substituent in position 9 and on the methyl ester functionality on the biological activity. The two separate enantiomers of methyl 9-hydroxystearate and of methyl 9-aminostearate showed antiproliferative activity against the HT29 cell line. This indicates the importance of position 9 groups being able to make hydrogen bonding with the molecular target. Further, this effect must be preserved when the carboxy group of 9-HSA is esterified. The biological tests showed that the amines, contrarily to methyl esters, resulted in cytotoxicity. A deep investigation on the effect of methyl (R)-9-hydroxystearate on HT29 cells showed an antiproliferative effect acting through the CDKN1A and MYCBP gene expression
Intriguing enigma of nitrobenzofuroxan's ‘Sphinx’: Boulton-Katritzky rearrangement or unusual evidence of theN-1/N-3-oxide rearrangement?
Full text linkThe SEAr/SNAr reaction between 7-chloro-4,6-dinitrobenzofuroxan (ClDNBF) and 2-morpholinyl-, 2-piperidinyl-, or 2-pyrrolidinylthiazole afforded unexpectedly two isomeric products, bearing the benzofuroxanyl moiety bound to the C-5 carbon atom of the thiazole ring. The relative ratio for the two isomers was dependent on temperature and solvent, suggesting the occurrence of an equilibrium between the two novel species. In order to investigate their structure and to design a plausible mechanistic pathway, a series of synthetic and spectroscopic experiments was planned. The isomer's structure was unambigously assigned when the reduction of furoxanyl to the furazanyl ring of the products gave exclusively a single species whose NMR data were coincident with those obtained by reacting the starting 2-aminothiazole derivatives with the 7-chloro-4,6-dinitrobenzofurazan (ClDNBZ). Possible mechanistic pathways might involveN-1-/N-3 oxide tautomerism or Boulton-Katritzky rearrangement and the current study is the first attempt to compare these two reactions. The data collected agree with the first one and DFT calculations permitted also a significant correlation with13C NMR experimental data and the assignment of the structure of each isomer. Finally, only one Meisenheimer intermediate for each electrophile/nucleophile combination was isolated by coupling the 2-aminothiazole derivatives with 4,6-dinitrobenzofuroxan (DNBF)
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
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