122,457 research outputs found
Chiroptical properties and conformational flexibility of fenoterol and analogues: a combined experimental and theoretical study
No full textFenoterol is a selective β 2 -adrenergic receptor (AR) agonist used in the treatment of asthma, which is
under scrutiny as possible drug against congestive heart failure. Fenoterol is currently used as a racemic
mixture of the (R,R′)- and (S,S′)-enantiomers, whose stereochemistry was previously determined by
electronic circular dichroism (ECD) analysis through the application of a semi-empirical sector rule. [1]
Recently, a series of fenoterol derivatives has been synthesized and tested: [2-3] their absolute
configuration was determined by chemical correlation with synthetic precursors, but no further
stereochemical characterization has been carried out. In addition, stereoselectivity in the binding to β 2 -
AR has been demonstrated, with (R,R′)- and (R,S′)-fenoterol displaying higher affinity compared to
(S,R′)- and (S,S′)-fenoterol, and a tridimensional quantitative structure-activity relationship model (3D-
QSAR) based on comparative molecular field analysis (CoMFA) has been developed to rationalize the
binding of fenoterol derivatives to β 2 -AR. [2-3]
The relationship between chiroptical properties and absolute stereochemistry of fenoterol and its
derivatives has been investigated [4] by experimental ECD analysis and quantum chemical (QC)
calculations using time-dependent density functional theory (TD-DFT). [5-6] The stereoisomers of three
compounds have been considered: fenoterol (1), (4′′-methoxy-1′′-naphthyl)fenoterol (2), and (4′′-methoxy-
1′-desmethyl)fenoterol (3). Due to the high conformational flexibility of the investigated structures and the
consequent large pool of equilibrium conformers, DFT geometry optimizations were carried out using the
resolution of identity (RI) approximation and the B97D functional with empirical dispersion corrections; [7]
TD-DFT calculations were then performed using the PBE0 functional. The accuracy of this protocol in
reproducing the experimental ECD spectra of fenoterol derivatives will be evaluated.
[1] F. Beigi, C. Bertucci, W. Zhu, K. Chakir, I.W. Wainer, R.P. Xiao, D.R. Abernethy, Chirality, 2006, 18, 822-827.
[2] K. Jóźwiak, K. Chakir, M.J. Tanga, I. Berzetei-Gurske, L. Jimenez, J.A. Kozocas, A. Woo, W. Zhu, R.P. Xiao,
D.R. Abernethy, I.W. Wainer, J. Med. Chem., 2007, 50, 2903-2915.
[3] K. Jóźwiak, A.Y.H. Woo, M.J. Tanga, L. Toll, L. Jimenez, J.A. Kozocas, A. Plazinska, R.P. Xiao, I.W. Wainer,
Bioorg. Med. Chem., 2010, 18, 728-736.
[4] ISCRA project IsC08_SCCFPM (ID: HP10CU0YHL) granted by CINECA, Bologna, Italy.
[5] J. Autschbach, Chirality, 2009, 21, E116-E152.
[6] L. Goerigk, H. Kruse, S. Grimme, in: N. Berova, P.L. Polavarapu, K. Nakanishi, R.W. Woody (Eds.),
Comprehensive chrioptical spectroscopy, vol. 1, 2011, Hoboken: Wiley & Sons, pp. 643-673.
[7] S. Grimme, WIREs Comput. Mol. Sci., 2011, 1, 211-228
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Higher interleukin-18 and mannose-binding lectin are present in uterine lumen of patients with unexplained infertility.
No full textThe uterine luminal environment was explored with regard to interleukin-18 (IL-18) and mannose-binding lectin (MBL) and the possibility that the procedure of flushing the uterine cavity would optimize the physiological initial pseudo-inflammatory uterine reaction. Uterine flushings were performed among 175 IVF/intracytoplasmic sperm injection (ICSI) patients at the time of oocyte retrieval and the cycles were compared with a control group matched for age, number of previous attempts and type of assisted reproductive procedure (IVF or ICSI) in which no flushing were performed (n = 175). Samples collected were divided into two groups according to the presence/absence of endometrial cells in samples. IL-18 and MBL expressions were explored by enzyme-linked immunosorbent assay. Implantation rates were significantly higher in those patients who underwent the uterine flushing compared with controls (P = 0.04). Luminal concentrations of IL-18 and MBL were higher if endometrial cells were present in flushings, suggesting endometrial origin of the secretion. Both concentrations of MBL and IL-18 were higher in patients with unexplained infertility compared with patients involved in IVF/ICSI for male or tubal infertility (P = 0.005 and 0.02, respectively). The exploration of the endoluminal environment before oocyte retrieval may enhance pregnancy rates and show distinct features in patients with unexplained infertility
Algunos determinantes de la restricción externa en la Argentina
No full textLa década en curso marca la reaparición de un viejo problema endémico de la economía nacional: la restricción externa. En este trabajo se analizan algunos de los principales factores estructurales que concurren a explicar esta dinámica en una economía periférica como la argentina. La indagación se focaliza en las modalidades predominantes de la inserción del país en la división internacional del trabajo (en un escenario signado por la ausencia de cambio estructural en el perfil de especialización vis a vis con los años de hegemonía neoliberal), en los efectos sobre las cuentas externas que se desprenden del notable predominio extranjero en la economía, y en la evolución de la fuga de capitales locales al exterior en una etapa, como la de la posconvertibilidad, signada por varios años de expansión económica inscriptos en un régimen de acumulación que, a diferencia del que lo antecedió, no ha pivotado alrededor de la actividad financiera y ha sentado las bases para la concreción de un proceso de desendeudamiento.Fil: Schorr, Martín. Universidad de Buenos Aires; Argentina. Facultad Latinoamericana de Ciencias Sociales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín; ArgentinaFil: Wainer, Andrés Gastón. Universidad Nacional de San Martín. Instituto de Altos Estudios Sociales; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Sociales; Argentin
Dissipative Range Scaling of Higher Order Structure Functions for Velocity and Passive Scalars
No full textDifferently to Kolmogorov's second similarity hypothesis, we find that the 2n-th order velocity and scalar structure functions scale with n-th order moment of the energy dissipation and the scalar dissipation, respectively. The origins of this scaling are analyzed by the transport equations of the fourth order velocity and scalar increment moments and by direct numerical simulations
Fast implementation of iterative adaptive approach for wideband unambiguous radar detection
No full textAccepted author manuscriptMicrowave Sensing, Signals & System
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