434 research outputs found
High-Precision Photothermal Ablation using Biocompatible Palladium Nanoparticles and Laser Scanning Microscopy
Herein, we report
a straightforward method for the scalable preparation of Pd nanoparticles
(Pd-NPs) with reduced inherent cytotoxicity and high photothermal
conversion capacity. These Pd-NPs are rapidly taken up by cells and
able to kill labeled cancer cells upon short exposure to near-infrared
(NIR) light. Following cell treatment with Pd-NPs, ablated areas were
patterned with high precision by laser scanning microscopy, allowing
one to perform cell migration assays with unprecedented accuracy.
Using coherent Raman microscopy, cells containing Pd-NPs were simultaneously
ablated and imaged. This novel methodology was combined with intravital
imaging to mediate microablation of cancerous tissue in tumor xenografts
in mice
Morphological evolution of pulsed laser deposited ZrO2 thin films
Morphological evolution of ZrO2 thin films deposited during pulsed laser deposition of Zr in O2
atmosphere has been experimentally studied at two different film deposition temperatures, 300 and
873 K. The roughness exponent, , the growth exponent, , the coarsening exponent, 1/z, and the
exponent defining the evolution of the characteristic wavelength of the surface, p, for depositions at
300 K amounted to = 1.00.1, = 0.40.1, 1/z= 0.340.03, and p= 0.490.03, whereas for
depositions carried out at 873 K amounted to = 0.30.3, = 0.40.2, and 1/z= 0.00.2.
Experimental error becomes important due to the flat morphology of the films inherent to the
deposition technique. The change in the surface topography with the film temperature has been
studied with the help of a simple Monte Carlo model which indicates the existence of two different
growth regimes: a shadowing dominated growth, occurring at low temperatures, characterized by
calculated values = 1.000.04, = 0.500.04, p= 0.460.01, and 1/z= 0.350.02 and a
diffusion dominated growth that takes place at high temperatures as well as at low deposition rates,
characterized by calculated values = 0.150.08, = 0.330.04, and 1/z= 0.330.07. The good
agreement obtained between the experimental and simulated parameters is discussed within the
frame of the general characteristics of the deposition method.Universidad Nacional Autónoma de México-PAPIIT-IN107808Consejo Nacional de Ciencia y Tecnología de México-CONACyT-50203-FMinisterio de Ciencia, Innovación y Universidades de España-MAT 2007-65764, PIE 200960I132 y CONSOLIDER INGENIO 2010-CSD2008-00023Junta de Andalucía-TEP2275 y P07-FQM-0329
Weak gauge principle and electric charge quantization
Starting from a weak gauge principle we give a new and critical revision of
the argument leading to charge quantization on arbitrary spacetimes. The main
differences of our approach with respect to previous works appear on spacetimes
with non trivial torsion elements on its second integral cohomology group. We
show that in these spacetimes there can be topologically non-trivial
configurations of charged fields which do not imply charge quantization.
However, the existence of a non-exact electromagnetic field always implies the
quantization of charges. Another consequence of the theory for spacetimes with
torsion is the fact that it gives rise to two natural quantization units that
could be identified with the electric quantization unit (realized inside the
quarks) and with the electron charge. In this framework the color charge can
have a topological origin, with the number of colors being related to the order
of the torsion subgroup. Finally, we discuss the possibility that the
quantization of charge may be due to a weak non-exact component of the
electromagnetic field extended over cosmological scales.Comment: Latex2e, 24 pages, no figure
MASSIV: Mass Assembly Survey with SINFONI in VVDS. V. The major merger rate of star-forming galaxies at 0.9 < z < 1.8 from IFS-based close pairs
We aim to measure the major merger rate of star-forming galaxies at 0.9 < z
<1.8, using close pairs identified from integral field spectroscopy (IFS). We
use the velocity field maps obtained with SINFONI/VLT on the MASSIV sample,
selected from the star-forming population in the VVDS. We identify physical
pairs of galaxies from the measurement of the relative velocity and the
projected separation (r_p) of the galaxies in the pair. Using the well
constrained selection function of the MASSIV sample we derive the gas-rich
major merger fraction (luminosity ratio mu = L_2/L_1 >= 1/4), and, using merger
time scales from cosmological simulations, the gas-rich major merger rate at a
mean redshift up to z = 1.54. We find a high gas-rich major merger fraction of
20.8+15.2-6.8 %, 20.1+8.0-5.1 % and 22.0+13.7-7.3 % for close pairs with r_p <=
20h^-1 kpc in redshift ranges z = [0.94, 1.06], [1.2, 1.5) and [1.5, 1.8),
respectively. This translates into a gas-rich major merger rate of
0.116+0.084-0.038 Gyr^-1, 0.147+0.058-0.037 Gyr^-1 and 0.127+0.079-0.042 Gyr^-1
at z = 1.03, 1.32 and 1.54, respectively. Combining our results with previous
studies at z < 1, the gas-rich major merger rate evolves as (1+z)^n, with n =
3.95 +- 0.12, up to z = 1.5. From these results we infer that ~35% of the
star-forming galaxies with stellar masses M = 10^10 - 10^10.5 M_Sun have
undergone a major merger since z ~ 1.5. We develop a simple model which shows
that, assuming that all gas-rich major mergers lead to early-type galaxies, the
combined effect of gas-rich and dry mergers is able to explain most of the
evolution in the number density of massive early-type galaxies since z ~ 1.5,
with our measured gas-rich merger rate accounting for about two-thirds of this
evolution.Comment: Published in Astronomy and Astrophysics, 24 pages, 30 figures, 2
tables. Appendix with the residual images from GALFIT added. Minor changes
with respect to the initial versio
New polymorphisms associated with response to anti-TNF drugs in patients with moderate-to-severe plaque psoriasis
Anti-tumor necrosis factor (anti-TNF) drugs are effective against psoriasis, although 20–30% of patients are nonresponders. Few pharmacogenomic studies have been performed to predict the response to anti-TNF drugs in psoriasis. We studied 173 polymorphisms to establish an association with the response to anti-TNF drugs in patients with moderate-to-severe plaque psoriasis (N=144). We evaluated the response using PASI75 at 3, 6 and 12 months. The results of the multivariate analysis showed an association between polymorphisms in PGLYR4, ZNF816A, CTNNA2, IL12B, MAP3K1 and HLA-C genes and the response at 3 months. Besides, the results for polymorphisms in IL12B and MAP3K1 were replicated at 6 months. We also obtained significant results for IL12B polymorphism at 1 year. Moreover, polymorphisms in FCGR2A, HTR2A and CDKAL1 were significant at 6 months. This is the first study to show an association with these polymorphisms. However, these biomarkers should be validated in large-scale studies before implementation in clinical practiceThis study was supported by Instituto de Salud Carlos III (FIS PI10/01740), Fundación
Teófilo Hernando, and AbbVie. RPP has a grant from Universidad Autónoma de
Madrid (FPI program 2013
Analyzing derived metallicities and ionization parameters from model-based determinations in ionized gaseous nebulae
We analyze the reliability of oxygen abundances and ionization parameters
obtained from different diagnostic diagrams. For this, we compiled from the
literature observational emission line intensities and oxygen abundance of 446
star-forming regions whose O/H abundance was determined by direct estimation of
electron temperature. The abundances compiled were compared with the values
calculated in this work using different diagnostic diagrams in combination with
results from a grid of photoionization models. We found that the
[\ion{O}{iii}]/[\ion{O}{ii}] vs. [\ion{N}{ii}]/[\ion{O}{ii}],
[\ion{O}{iii}]/H vs. [\ion{N}{ii}]/[\ion{O}{ii}], and
([\ion{O}{iii}]/H)/([\ion{N}{ii}]/H) vs.
[\ion{S}{ii}]/[\ion{S}{iii}] diagnostic diagrams give O/H values close to the
-method, with differences of about 0.04 dex and dispersion of about
0.3 dex. Similar results were obtained by detailed models but with a dispersion
of 0.08 dex. The origin of the dispersion found in the use of diagnostic
diagrams is probably due to differences between the real N/O-O/H relation of
the sample and the one assumed in the models. This is confirmed by the use of
detailed models that do not have a fixed N/O-O/H relation. We found no
correlation between ionization parameter and the metallicity for the objects of
our sample. We conclude that the combination of two line ratio predicted by
photoionization models, one sensitive to the metallicity and another sensitive
to the ionization parameter, which takes into account the physical conditions
of star-forming regions, gives O/H estimates close to the values derived using
direct detections of electron temperatures.Comment: 12 pages, 9 figures, accepted by MNRA
A peculiar class of debris disks from Herschel/DUNES - A steep fall off in the far infrared
Aims. We present photometric data of debris disks around HIP 103389 (HD
199260), HIP 107350 (HN Peg, HD206860), and HIP 114948 (HD 219482), obtained in
the context of our Herschel Open Time Key Program DUNES (DUst around NEarby
Stars). Methods. We used Herschel/PACS to detect the thermal emission of the
three debris disks with a 3 sigma sensitivity of a few mJy at 100 um and 160
um. In addition, we obtained Herschel/PACS photometric data at 70 um for HIP
103389. Two different approaches are applied to reduce the Herschel data to
investigate the impact of data reduction on the photometry. We fit analytical
models to the available spectral energy distribution (SED) data. Results. The
SEDs of the three disks potentially exhibit an unusually steep decrease at
wavelengths > 70 um. We investigate the significance of the peculiar shape of
these SEDs and the impact on models of the disks provided it is real. Our
modeling reveals that such a steep decrease of the SEDs in the long wavelength
regime is inconsistent with a power-law exponent of the grain size distribution
-3.5 expected from a standard equilibrium collisional cascade. In contrast, a
very distinct range of grain sizes is implied to dominate the thermal emission
of such disks. However, we demonstrate that the understanding of the data of
faint sources obtained with Herschel is still incomplete and that the
significance of our results depends on the version of the data reduction
pipeline used. Conclusions. A new mechanism to produce the dust in the
presented debris disks, deviations from the conditions required for a standard
equilibrium collisional cascade (grain size exponent of -3.5), and/or
significantly different dust properties would be necessary to explain the
potentially steep SED shape of the three debris disks presented. (abridged)Comment: 14 pages, 4 figures, accepted by A&
The intrinsic shape of galaxy bulges
The knowledge of the intrinsic three-dimensional (3D) structure of galaxy
components provides crucial information about the physical processes driving
their formation and evolution. In this paper I discuss the main developments
and results in the quest to better understand the 3D shape of galaxy bulges. I
start by establishing the basic geometrical description of the problem. Our
understanding of the intrinsic shape of elliptical galaxies and galaxy discs is
then presented in a historical context, in order to place the role that the 3D
structure of bulges play in the broader picture of galaxy evolution. Our
current view on the 3D shape of the Milky Way bulge and future prospects in the
field are also depicted.Comment: Invited Review to appear in "Galactic Bulges" Editors: Laurikainen
E., Peletier R., Gadotti D. Springer Publishing. 24 pages, 7 figure
The Spanish Infrared Camera onboard the EUSO-BALLOON (CNES) flight on August 24, 2014
The EUSO-Balloon (CNES) campaign was held during Summer 2014 with a launch on August
24. In the gondola, next to the Photo Detector Module (PDM), a completely isolated Infrared
camera was allocated. Also, a helicopter which shooted flashers flew below the balloon. We have
retrieved the Cloud Top Height (CTH) with the IR camera, and also the optical depth of the nonclear atmosphere have been inferred with two approaches: The first one is with the comparison of the brightness temperature of the cloud and the real temperature obtained after the pertinent
corrections. The second one is by measuring the detected signal from the helicopter flashers by the IR Camera, considering the energy of the flashers and the location of the helicopter
Comparing inequalities in the labour market from a segmentation perspective
Production of INCASI Project H2020-MSCA-RISE-2015 GA 691004The purpose of this chapter is to carry out a comparative analysis of labour markets in Europe and Latin America from the perspective of segmentation in order to explain the processes of social inequality that arise in the workplace, in light of recent trends in global socio-economic changes. The chapter proposes two main objectives. The first is to perform a comparative descriptive analysis of the main features of labour markets among 60 European and Latin American countries. The second objective is to propose a model of comparative analysis of labour inequality from the theoretical perspective of the segmentation of the labour market and structural heterogeneity. We will focus our analysis by selecting two countries, Spain and Argentina, which both underwent a late development of capitalism. The following general hypothesis is formulated: Spain and Argentina, having clearly differentiated features in economic structure, level of development, institutional frameworks and socio-historical processes, show common dynamics in the structuring of the capitalist labour market between a primary and secondary segment. Using equivalent databases on the workforce a typology of segmentation of employment is constructed that show, in addition to the specificities of each country, the similarities in the structuring of the labour market
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