548 research outputs found
Heterodi- (Fe, Pd/Pt) and heterotrimetallic (Fe2, Pd) complexes derived from 4-(ferrocenylmethyl)-N-(2-methoxyethyl)-3,5-diphenylpyrazole as potential antitumoral agents
The study of the reactivity of the pyrazole derivative 1-[MeO-(CH2)2]-3,5-Ph2-4-(CH2Fc) (C3N2) (1, Fc = ferrocenyl) with Na2[PdCl4], Pd(OAc)2, and [MCl2(dmso)2] (M = Pd or Pt,dmso = dimethyl sulfoxide) has allowed us to isolate trans-[Pd{κ-N-(1-{MeO(CH2)2}-3,5-Ph2-4-{CH2Fc} {C3N2})}2Cl2] (2), [Pd{κ2-C,N(1-{MeO(CH2)2}-3-{C6H4}-5-Ph-{C3N2})}{κ-N-(1-{MeO(CH2)2}-3,5-Ph2-4-{CH2Fc} {C3N2})}Cl] (3), [Pd{κ2-C,N(1-{MeO(CH2)2}-3-{C6H4}-4-{CH2Fc}-5-Ph-{C3N2})}Cl-(PPh3)] (4), and the trans (5) and cis (6) isomers of [Pt{κ-N-(1-{MeO(CH2)2}-3,5-Ph24-{CH2Fc} {C3N2})}Cl2(dmso)]. Compound 1 acts as a N (in 2, 5, and 6) or (C,N) donor ligand (in 4) and shows both binding modes in 3. The cytotoxic assessment of 1 6 against MCF7, MDA-MB231 (breast), and HCT-116 (colon) cancer cell lines reveal that (1) 1 is more potent than 1-[MeO(CH2)2]-3,5-Ph2-(C3HN2) (V), (2) 2 6 have cytotoxic activity, (3) 2 and 3 are less active than 4 6, and (4) 6 is the most potent compound against the three cancer cell lines
Ram pressure profiles in galaxy groups and clusters
Using a hybrid method which combines non-radiative hydrodynamical simulations
with a semi-analytic model of galaxy formation, we determine the ram pressure
as a function of halocentric distance experienced by galaxies in haloes with
virial masses 12.5 <= log (M_200 h/M_Sun) < 15.35, for redshifts 0 <= z <= 3.
The ram pressure is calculated with a self-consistent method which uses the
simulation gas particles to obtain the properties of the intergalactic medium.
The ram pressure profiles obtained can be well described by beta profile
models, with parameters that depend on redshift and halo virial mass in a
simple fashion. The fitting formulae provided here will prove useful to include
ram pressure effects into semi-analytic models based on methods which lack gas
physics, such as dark matter-only simulations or the Press-Schechter formalism.Comment: 7 pages, 6 figures. Accepted for publication in MNRA
Synthesis, characterization, crystal structures and computational studies on novel cyrhetrenyl hydrazones
The synthesis of novel cyrhetrenyl hydrazones of general formula [Re{(η5-C5H4)single bondC(R1) = NNHR2}(CO)3] {with R1 = H and R2 = 4-NO2single bondC6H4 (4a), C6H5 (4b) or H (4c) or R1 = Me and R2 = 4-NO2single bondC6H4 (5a), C6H5 (5b) or H (5c)} is described. Compounds 4a-4c and 5a-5c were characterized by mass spectrometry and IR spectroscopy. 1H and 13C{1H} NMR studies revealed that 4a-4c and 5a-5c adopt the anti-(E) configuration in solution. X-ray crystal structures of compounds 4a and 5c confirmed the trans-arrangement of the cyrhetrenyl 'Re(η5-C5H4)(CO)3' and the -NHR2 moieties and the existence of strong hydrogen bonds involving the single bondNHsingle bond unit. Molecular Orbital calculations at a DFT level have also been carried out in order to rationalize the influence of the nature of the substituent R3 of [R3CH = NNH(4-NO2single bondC6H4)] (R3 = ferrocenyl, (3a), cyrhetrenyl (4a), phenyl (6a) or cymantrenyl (7a) on the electronic delocalization, the nucleophilicity of the imine carbon, the polarizability and hyperpolarizability of these compounds, and computational studies using time-dependent density functional (TD-DFT) calculations have also been carried out in order to assign the bands detected in their electronic spectra and to explain the effect produced by the solvent
Dual targeted therapy in patients with psoriatic arthritis and spondyloarthritis: a real-world multicenter experience from Spain
Dual targeted therapy (DTT) has emerged as a promising approach in patients with refractory spondyloarthritis (SpA) or psoriatic arthritis (PsA) and extra-musculoskeletal manifestations of both diseases, but its effectiveness/safety ratio still remains unclear. This is a retrospective, real-world multicenter study in refractory SpA and PsA patients with simultaneous use of two biological or synthetic targeted agents. Effectiveness was assessed using Ankylosing Spondylitis Disease Activity Score with C-reactive protein (ASDAS-CRP) and Disease Activity in Psoriatic Arthritis (DAPSA) Score. We identified 39 different DTT combinations in 36 patients (22 SpA; 14 PsA), 25 of them with concomitant inflammatory bowel disease. The most commonly used combinations were TNF inhibitor plus antagonist of the IL12/23 pathway, followed by TNF inhibitor plus IL-17 antagonist. During a median exposure of 14.86 months (IQR 8-20.2), DTT retention rate was 69.4% (n=25/36; 19 SpA, 6 PsA). Major clinical improvement (change in ASDAS-CRP > 2 or improvement > 85% in DAPSA) was achieved in 69.4% of patients (n=25/36 therapeutical combinations; 17/21 SpA, 8/15 PsA), with a 58.3% (n=21/36 combinations; 15/20 SpA, 6/13 PsA) low-activity/remission rate. Of the patients who were receiving glucocorticoids, 55% managed to withdraw them during follow-up. Interestingly, only four serious adverse events in three patients were observed, leading to DTT discontinuation
Clínica jurídica, una forma de aprendizaje-servicio para la protección de Derechos humanos
[spa] El artículo explica los primeros pasos dados en el desarrollo del proyecto "Clínica jurídica: una forma de aprendizaje-servicio para la protección de derechos humanos" en la Universidad de Valladolid, cuyo principal objetivo consiste en la formación de juristas socialmente comprometidos.[eng] The paper explains the first steps given on the development of the Project “Clínica jurídica: una forma de aprendizaje-servicio para la protección de derechos humanos“ at the University of Valladolid which main aim would be a social engaged lawyers training
Probing quantum gravity using photons from a flare of the active galactic nucleus Markarian 501 observed by the MAGIC telescope
We analyze the timing of photons observed by the MAGIC telescope during a
flare of the active galactic nucleus Mkn 501 for a possible correlation with
energy, as suggested by some models of quantum gravity (QG), which predict a
vacuum refractive index \simeq 1 + (E/M_{QGn})^n, n = 1,2. Parametrizing the
delay between gamma-rays of different energies as \Delta t =\pm\tau_l E or
\Delta t =\pm\tau_q E^2, we find \tau_l=(0.030\pm0.012) s/GeV at the 2.5-sigma
level, and \tau_q=(3.71\pm2.57)x10^{-6} s/GeV^2, respectively. We use these
results to establish lower limits M_{QG1} > 0.21x10^{18} GeV and M_{QG2} >
0.26x10^{11} GeV at the 95% C.L. Monte Carlo studies confirm the MAGIC
sensitivity to propagation effects at these levels. Thermal plasma effects in
the source are negligible, but we cannot exclude the importance of some other
source effect.Comment: 12 pages, 3 figures, Phys. Lett. B, reflects published versio
Unfolding of differential energy spectra in the MAGIC experiment
The paper describes the different methods, used in the MAGIC experiment, to
unfold experimental energy distributions of cosmic ray particles (gamma-rays).
Questions and problems related to the unfolding are discussed. Various
procedures are proposed which can help to make the unfolding robust and
reliable. The different methods and procedures are implemented in the MAGIC
software and are used in most of the analyses.Comment: Submitted to NIM
Implementation of the Random Forest Method for the Imaging Atmospheric Cherenkov Telescope MAGIC
The paper describes an application of the tree classification method Random
Forest (RF), as used in the analysis of data from the ground-based gamma
telescope MAGIC. In such telescopes, cosmic gamma-rays are observed and have to
be discriminated against a dominating background of hadronic cosmic-ray
particles. We describe the application of RF for this gamma/hadron separation.
The RF method often shows superior performance in comparison with traditional
semi-empirical techniques. Critical issues of the method and its implementation
are discussed. An application of the RF method for estimation of a continuous
parameter from related variables, rather than discrete classes, is also
discussed.Comment: 16 pages, 8 figure
First bounds on the high-energy emission from isolated Wolf-Rayet binary systems
High-energy gamma-ray emission is theoretically expected to arise in tight
binary star systems (with high mass loss and high velocity winds), although the
evidence of this relationship has proven to be elusive so far. Here we present
the first bounds on this putative emission from isolated Wolf-Rayet (WR) star
binaries, WR 147 and WR 146, obtained from observations with the MAGIC
telescope.Comment: (Authors are the MAGIC Collaboration.) Manuscript in press at The
Astrophysical Journal Letter
Discovery of Very High Energy gamma-rays from 1ES 1011+496 at z=0.212
We report on the discovery of Very High Energy (VHE) gamma-ray emission from
the BL Lacertae object 1ES1011+496. The observation was triggered by an optical
outburst in March 2007 and the source was observed with the MAGIC telescope
from March to May 2007. Observing for 18.7 hr we find an excess of 6.2 sigma
with an integrated flux above 200 GeV of (1.58 photons
cm s. The VHE gamma-ray flux is >40% higher than in March-April
2006 (reported elsewhere), indicating that the VHE emission state may be
related to the optical emission state. We have also determined the redshift of
1ES1011+496 based on an optical spectrum that reveals the absorption lines of
the host galaxy. The redshift of z=0.212 makes 1ES1011+496 the most distant
source observed to emit VHE gamma-rays up to date.Comment: 4 pages, 6 figures, minor changes to fit the ApJ versio
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