1,720,962 research outputs found
Risanamento di siti esposti ad elevati campi a radiofrequenza mediante tecniche di schermaturatrasparenti alla luce
NMR relaxometric investigation on human methemoglobin and fluoromethemoglobin. An improved quantitative in vitro assay of human methemoglobin
NMR RELAXOMETRIC INVESTIGATION ON HUMAN METHEMOGLOBIN AND FLUOROMETHEMOGLOBIN - AN IMPROVED QUANTITATIVE IN-VITRO ASSAY OF HUMAN METHEMOGLOBIN
Metal complexes as allosteric effectors of human hemoglobin: An NMR study of the interaction of the gadolinium(III) bis(m-boroxyphenylamide)diethylenetriaminepentaacetic acid complex with human oxygenated and deoxygenated hemoglobin
The boronic functionalities on the outer surface of the Gd(III) bis(m-boroxyphenylamide)DTPA complex (Gd(III)L) enable it to bind to fructosamine residues of oxygenated glycated human adult hemoglobin. The formation of the macromolecular adduct can be assessed by NMR spectroscopy via observation of the enhancement of the solvent water proton relaxation rate. Unexpectedly, a strong binding interaction was also observed for the oxygenated unglycated human adult hemoglobin, eventually displaying a much higher relaxation enhancement. From relaxation rate measurements it was found that two Gd(III)L complexes interact with one hemoglobin tetramer (K-D = 1.0 x 10(-5) M and 4.6 x 10(-4) M, respectively), whereas no interaction has been observed with monomeric hemoproteins. A markedly higher affinity of the Gd(III)L complex has been observed for oxygenated and aquo-met human adult hemoglobin derivatives with respect to the corresponding deoxy derivative. Upon binding, a net change in the quaternary structure of hemoglobin has been assessed by monitoring the changes in the high-resolution H-1-NMR spectrum of the protein as well as in the Soret absorption band. On the basis of these observations and the B-11 NMR results obtained with the diamagnetic La(III)L complex, we suggest that the interaction between the lanthanide complex and deoxygenated, oxygenated, and aquo-met derivatives of human adult hemoglobin takes place at the 2,3-diphosphoglycerate (DPG) binding site, through the formation of N-->B coordinative bonds at His(143 beta) and His(2 beta) residues of different beta-chains. The stronger binding to the oxygenated form is then responsible for a shift of the allosteric equilibrium toward the high-affinity R-state. Accordingly, Gd(III)L affinity for oxygenated human fetal hemoglobin (tacking His(143 beta)) is significantly lower than that observed for the unglycated human adult tetramer
SYNTHESIS AND CHARACTERIZATION OF A NOVEL DTPA-LIKE GADOLINIUM(III) COMPLEX - A POTENTIAL REAGENT FOR THE DETERMINATION OF GLYCATED PROTEINS BY WATER PROTON NMR RELAXATION MEASUREMENTS
Quantitative determination of methemoglobin by measuring the solvent-water proton-nuclear magnetic resonance relaxation rate
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
QUANTITATIVE-DETERMINATION OF METHEMOGLOBIN BY MEASURING THE SOLVENT-WATER PROTON-NUCLEAR MAGNETIC-RESONANCE RELAXATION RATE
Variations on the Author
“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
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