733 research outputs found
Force spectroscopy-based simultaneous topographical and mechanical characterization to study polymer-to-polymer interactions in coated alginate microspheres
Cell-laden hydrogel microspheres have shown encouraging outcomes in the fields of drug delivery, tissue engineering or regenerative medicine. Beyond the classical single coating with polycations, many other different coating designs have been reported with the aim of improving mechanical properties and in vivo performance of the microspheres. Among the most common strategies are the inclusion of additional polycation coatings and the covalent bonding of the semi-permeable membranes with biocompatible crosslinkers such as genipin. However, it remains challenging to characterize the effects of the interactions between the polycations and the hydrogel microspheres over time in vitro. Here we use a force spectroscopy-based simultaneous topographical and mechanical characterization to study polymer-to-polymer interactions in alginate microspheres with different coating designs, maintaining the hydrogels in liquid. In addition to classical topography parameters, we explored, for the first time, the evolution of peak/valley features along the z axis via thresholding analysis and the cross-correlation between topography and stiffness profiles with resolution down to tens of nanometers. Thus, we demonstrated the importance of genipin crosslinking to avoid membrane detachment in alginate microspheres with double polycation coatings. Overall, this methodology could improve hydrogel design rationale and expedite in vitro characterization, therefore facilitating clinical translation of hydrogel-based technologies
Phase II randomized study of Plitidepsin (Aplidin), alone or in association with L-carnitine, in patients with unresectable advanced renal cell carcinoma
This randomized phase II study evaluated two schedules of the marine compound Plitidepsin with or without co-administration of L-carnitine in patients with renal cell carcinoma. Patients had adequate performance status and organ function.The primary endpoint was the rate of disease control (no progression) at 12 weeks (RECIST).Other endpoints included the response rate and time dependent efficacy measures.The trial also assessed the efficacy of L-carnitine to prevent Plitidepsin-related toxicity. The two regimes given as 24 hour infusion every two weeks showed hints of antitumoral activity. Disease control at 12 weeks was 15.8% in Arm A (5mg/m2, no L-carnitine) and 11,1% in Arm B (7mg/m2 with L-carnitine). Two partial responses were observed in Arm A (19 patients), none in Arm B (20 patients). Both schedules had the same progression-free interval (2.1 months).The median overall survival was 7.0 and 7.6 months.The safety profile was similar in both arms of the trial and adverse events were mainly mild to moderate (NCI CTC version 2.0). Increasing the dose to 7mg/m2 did not increase the treatment efficacy but the incidence of transaminase and CPK elevations and serious AEs. Coadministration of L-carnitine did not prevent muscular toxicity or CPK-elevation associated with Plitidepsin
The GALEX Ultraviolet Atlas of Nearby Galaxies
We present images, integrated photometry, surface-brightness and color
profiles for a total of 1034 nearby galaxies recently observed by the GALEX
satellite in its far-ultraviolet (FUV; 1516A) and near-ultraviolet (NUV; 2267A)
bands. (...) This data set has been complemented with archival optical,
near-infrared, and far-infrared fluxes and colors. We find that the integrated
(FUV-K) color provides robust discrimination between elliptical and
spiral/irregular galaxies and also among spiral galaxies of different
sub-types. Elliptical galaxies with brighter K-band luminosities (i.e. more
massive) are redder in (NUV-K) color but bluer in (FUV-NUV) than less massive
ellipticals. In the case of the spiral/irregular galaxies our analysis shows
the presence of a relatively tight correlation between the (FUV-NUV) color and
the total infrared-to-UV ratio. The correlation found between (FUV-NUV) color
and K-band luminosity (with lower luminosity objects being bluer than more
luminous ones) can be explained as due to an increase in the dust content with
galaxy luminosity.
The images in this Atlas along with the profiles and integrated properties
are publicly available through a dedicated web page at
http://nedwww.ipac.caltech.edu/level5/GALEX_Atlas/Comment: 181 pages, 10 figures, accepted for publication in ApJS (abstract
abridged
Hallucination-minimized Data-to-answer Framework for Financial Decision-makers
Large Language Models (LLMs) have been applied to build several automation
and personalized question-answering prototypes so far. However, scaling such
prototypes to robust products with minimized hallucinations or fake responses
still remains an open challenge, especially in niche data-table heavy domains
such as financial decision making. In this work, we present a novel
Langchain-based framework that transforms data tables into hierarchical textual
data chunks to enable a wide variety of actionable question answering. First,
the user-queries are classified by intention followed by automated retrieval of
the most relevant data chunks to generate customized LLM prompts per query.
Next, the custom prompts and their responses undergo multi-metric scoring to
assess for hallucinations and response confidence. The proposed system is
optimized with user-query intention classification, advanced prompting, data
scaling capabilities and it achieves over 90% confidence scores for a variety
of user-queries responses ranging from {What, Where, Why, How, predict, trend,
anomalies, exceptions} that are crucial for financial decision making
applications. The proposed data to answers framework can be extended to other
analytical domains such as sales and payroll to ensure optimal hallucination
control guardrails.Comment: 11 pages, 5 figures, 4 table
Inflammatory potential of diet and bone mineral density in a senior Mediterranean population : a cross-sectional analysis of PREDIMED-Plus study
Inflammation could play a key role in tissue damage and bone metabolism. The modified dietary inflammatory score (M-DIS) is a validated tool to estimate the inflammatory potential of the diet. In the present study, we evaluate the associations between the M-DIS and bone mineral density (BMD) in a senior Mediterranean population with overweight/obesity and metabolic syndrome. Baseline cross-sectional association between the M-DIS and bone mineral density was assessed in 1134 participants of the multicenter PREDIMED-Plus trial (aged 55-75 with overweight/obesity and metabolic syndrome). BMD was measured using Dual-energy X-ray Absorptiometry scans and participants answered a food frequency questionnaire to determine the M-DIS. BMD was categorized as low BMD when T score was equal or lower than -1 and normal BMD in another case. Associations between BMD and M-DIS were evaluated by using linear and logistic regressions adjusted by other co-variates. Participants in the top tertile of the M-DIS had a lower BMD at total femur [ÎČ (95% CI) â 0.02 (â 0.04, â 0.01)], trochanter areas [ÎČ (95% CI) â 0.03 (â 0.05, â 0.01)] and lumbar spine area [ÎČ (95% CI) â 0.03 (â 0.07, 0.01)] (but in the last case, measures were less precise and hence not statistically significant) compared to those in the lower M-DIS tertile. Multiple logistic regression analyses showed that the odds of the total femur and femoral trochanter osteopenia/osteoporosis were higher in participants in the top tertile compared to those in the lowest tertile of M-DIS [OR (95% CI) 1.71 (1.12, 2.64), P for trend 0.015; 2.02 (1.29, 3.21), P for trend 0.002, respectively]. A high pro-inflammatory diet, measured by the M-DIS, is associated with lower BMD in a senior Mediterranean population with metabolic syndrome. The online version contains supplementary material available at 10.1007/s00394-021-02751-5
GALEX UV Color Relations for Nearby Early-Type Galaxies
We use GALEX/optical photometry to construct color-color relationships for
early-type galaxies sorted by morphological type. We have matched objects in
the GALEX GR1 public release and the first IR1.1 internal release, with the RC3
early-type galaxies having a morphological type -5.5<T<-1.5 with mean error in
T<1.5, and mean error on (B-V)T<0.05. After visual inspection of each match, we
are left with 130 galaxies with a reliable GALEX pipeline photometry in the
far-UV and near-UV bands. This sample is divided into Ellipticals (-5.5<T<-3.5)
and Lenticulars (-3.5<T<-1.5). After correction for the Galactic extinction,
the color-color diagrams FUV-NUV vs. (B-V)_{Tc} are plotted for the two
subsamples. We find a tight anti-correlation between the FUV-NUV and (B-V)_{Tc}
colors for Ellipticals, the UV color getting bluer when the (B-V)_{Tc} get
redder. This relationship very likely is an extension of the color-metallicity
relationship into the GALEX NUV band. We suspect that the main source of the
correlation is metal line blanketing in the NUV band. The FUV-NUV vs B-V
correlation has larger scatter for lenticular galaxies; we speculate this
reflects the presence of low level star formation. If the latter objects (i.e.
those that are blue both in FUV-NUV and B-V) are interpreted as harboring
recent star formation activity, this would be the case for a few percent (~4%)
of Ellipticals and ~15% of Lenticulars; this would make about 10% of early-type
galaxies with residual star formation in our full sample of 130 early-type
galaxies. We also plot FUV-NUV vs. the Mg_2 index and central velocity
dispersion. We find a tight anti-correlation between FUV-NUV and the Mg_2
index(...).Comment: 25 pages, 5 figures, accepted for publication in ApJS (abstract
abridged), typos corrected in section 2.
Ultraviolet through Infrared Spectral Energy Distributions from 1000 SDSS Galaxies: Dust Attenuation
The meaningful comparison of models of galaxy evolution to observations is
critically dependent on the accurate treatment of dust attenuation. To
investigate dust absorption and emission in galaxies we have assembled a sample
of ~1000 galaxies with ultraviolet (UV) through infrared (IR) photometry from
GALEX, SDSS, and Spitzer and optical spectroscopy from SDSS. The ratio of IR to
UV emission (IRX) is used to constrain the dust attenuation in galaxies. We use
the 4000A break as a robust and useful, although coarse, indicator of star
formation history (SFH). We examine the relationship between IRX and the UV
spectral slope (a common attenuation indicator at high-redshift) and find
little dependence of the scatter on 4000A break strength. We construct average
UV through far-IR spectral energy distributions (SEDs) for different ranges of
IRX, 4000A break strength, and stellar mass (M_*) to show the variation of the
entire SED with these parameters. When binned simultaneously by IRX, 4000A
break strength, and M_* these SEDs allow us to determine a low resolution
average attenuation curve for different ranges of M_*. The attenuation curves
thus derived are consistent with a lambda^{-0.7} attenuation law, and we find
no significant variations with M_*. Finally, we show the relationship between
IRX and the global stellar mass surface density and gas-phase-metallicity.
Among star forming galaxies we find a strong correlation between IRX and
stellar mass surface density, even at constant metallicity, a result that is
closely linked to the well-known correlation between IRX and star-formation
rate.Comment: 12 pages, 8 figures, 2 tables, appearing in the Dec 2007 GALEX
special issue of ApJ Supp (29 papers
The Diverse Properties of the Most Ultraviolet Luminous Galaxies Discovered by the Galaxy Evolution Explorer
We report on the properties of a sample of ultraviolet luminous galaxies
(UVLGs) selected by matching the Galaxy Evolution Explorer (GALEX) Surveys with
the Sloan Digital Sky Survey Third Data Release. Out of 25362 galaxies between
0.02x10^10 L_solar at
1530 Angstroms (observed wavelength). The properties of this population are
well correlated with ultraviolet surface brightness. We find that the galaxies
with low UV surface brightness are primarily large spiral systems with a
mixture of old and young stellar populations, while the high surface brightness
galaxies consist primarily of compact starburst systems. In terms of the
behavior of surface brightness with luminosity, size with luminosity, the
mass-metallicity relation, and other parameters, the compact UVLGs clearly
depart from the trends established by the full sample of galaxies. The subset
of compact UVLGs with the highest surface brightness (``supercompact UVLGs'')
have characteristics that are remarkably similar to Lyman Break Galaxies at
higher redshift. They are much more luminous than typical local
ultraviolet-bright starburst galaxies and blue compact dwarf galaxies. They
have metallicities that are systematically lower than normal galaxies of the
same stellar mass, indicating that they are less chemically evolved. In all
these respects, they are the best local analogs for Lyman Break Galaxies.Comment: Fixed error in ObjID column of Table 1. 30 pages, 12 figures.
Accepted for the GALEX special issue of ApJS. Abstract abridge
Recent star formation in nearby galaxies from GALEX imaging:M101 and M51
The GALEX (Galaxy Evolution Explorer) Nearby Galaxies Survey is providing
deep far-UV and near-UV imaging for a representative sample of galaxies in the
local universe. We present early results for M51 and M101, from GALEX UV
imaging and SDSS optical data in five bands. The multi-band photometry of
compact stellar complexes in M101 is compared to population synthesis models,
to derive ages, reddening, reddening-corrected luminosities and current/initial
masses. The GALEX UV photometry provides a complete census of young compact
complexes on a approximately 160pc scale. A galactocentric gradient of the
far-UV - near-UV color indicates younger stellar populations towards the outer
parts of the galaxy disks, the effect being more pronounced in M101 than in
M51.Comment: This paper will be published as part of the Galaxy Evolution Explorer
(GALEX) Astrophysical Journal Letters Special Issue. Full paper available
from http://dolomiti.pha.jhu.edu . Links to full set of papers will be
available at http://www.galex.caltech.edu/PUBLICATIONS/ after November 22,
200
Probing the Intermediate-Age Globular Clusters in NGC 5128 from Ultraviolet Observations
We explore the age distribution of the globular cluster (GC) system of the
nearby elliptical galaxy NGC 5128 using ultraviolet (UV) photometry from Galaxy
Evolution Explorer (GALEX) observations, with UV - optical colors used as the
age indicator. Most GCs in NGC 5128 follow the general trends of GCs in M31 and
Milky Way in UV - optical color-color diagram, which indicates that the
majority of GCs in NGC 5128 are old similar to the age range of old GCs in M31
and Milky Way. A large fraction of spectroscopically identified
intermediate-age GC (IAGC) candidates with ~ 3-8 Gyr are not detected in the
FUV passband. Considering the nature of intermediate-age populations being
faint in the far-UV (FUV) passband, we suggest that many of the
spectroscopically identified IAGCs may be truly intermediate in age. This is in
contrast to the case of M31 where a large fraction of spectroscopically
suggested IAGCs are detected in FUV and therefore may not be genuine IAGCs but
rather older GCs with developed blue horizontal branch stars. Our UV photometry
strengthens the results previously suggesting the presence of GC and stellar
subpopulation with intermediate age in NGC 5128. The existence of IAGCs
strongly indicates the occurrence of at least one more major star formation
episode after a starburst at high redshift.Comment: 8 pages, 3 figures, accepted for ApJ Lette
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