29 research outputs found
Assessment Of Circulating Endothelial Cells And Their Progenitors As Potential Biomarkers Of Disease Activity And Damage Accrual In Behçet's Syndrome
PURPOSE: To explore the potential role of circulating endothelial cells (CECs) and their progenitors (EPCs) as biomarkers of disease activity and damage accrual in patients with Behçet's syndrome (BS), by using a standardised and reliable flow cytometry protocol. PATIENTS AND METHODS: CECs and EPCs were assessed in 32 BS patients and 11 gender/age/smoking habits matched healthy controls (HC). They were identified by flow cytometry as alive/nucleated/CD45-negative/CD34-bright/CD146-positive and alive/nucleated/CD45-negative/CD34-bright/CD309-positive events, respectively. In BS patients, demographic and clinical features, including disease activity (assessed by Behçet's disease current disease activity form, BDCAF) and irreversible damage accrual (by the vasculitis damage index, VDI) were recorded. Uni- and multivariate analysis were performed to compare the CECs and EPCs concentrations in BS vs HC and to identify potential associations with demographic or clinical features. RESULTS: The CECs concentration was significantly higher in the BS patients than HCs [median (IQR) 15.0 (7.5-23.0) vs 6.0 (2.0-13.0) CECs/mL, p=0.024]. In BS patients, no significant associations were found between CECs and demographic features, present and past clinical manifestations, BDCAF score and ongoing treatment. A significant association was observed between CECs and organ damage, as assessed by the VDI (rho 0.356, p=0.045). Higher levels of CECs were especially associated with vascular damage [median (IQR) 23.0 (14.0-47.0) vs 13.0 (6.0-19.0) CECs/mL, p=0.011], including arterial aneurysm and stenosis, complicated venous thrombosis, cerebrovascular accident. The concentration of EPCs did not significantly differ between the BS and HC [median 26.5 (13.0-46.0) vs 19.0 (4.0-42.0) EPCs/mL, p=0.316] and no significant associations were observed between their levels and any clinical characteristic. CONCLUSION: Our study suggests that the CECs concentration is significantly higher in BS than healthy subjects, and it mainly correlates with vascular damage. A longitudinal extension of the present study on a wider cohort would be useful to validate the potential role of CECs as a marker or, hopefully, predictor of vascular damage in BS
Recent advances in structure and function of cytosolic IMP-GMP specific 5′nucleotidase II (cN-II)
Cytosolic 5′nucleotidase II (cN-II) catalyses both the hydrolysis of a number of nucleoside monophosphates (e.g., IMP + H2O→inosine + Pi), and the phosphate transfer from a nucleoside monophosphate donor to the 5′position of a nucleoside acceptor (e.g., IMP + guanosine →inosine + GMP). The enzyme protein functions through the formation of a covalent phosphoenzyme intermediate, followed by the phosphate transfer either to water (phosphatase activity) or to a nucleoside (phosphotransferase activity). It has been proposed that cN-II regulates the intracellular concentration of IMP and GMP and the production of uric acid. The enzyme might also have a potential therapeutic importance, since it can phosphorylate some anti-tumoral and antiviral nucleoside analogues that are not substrates of known kinases. In this review we summarise our recent studies on the structure, regulation and function of cN-II. Via a site-directed mutagenesis approach, we have identified the amino acids involved in the catalytic mechanism and proposed a structural model of the active site. A series of in vitro studies suggests that cN-II might contribute to the regulation of 5-phosphoribosyl-1-pyrophosphate (PRPP) level, through the so-called oxypurine cycle, and in the production of intracellular adenosine, formed by ATP degradation
The production of ionizing photons in UV-faint z~3-7 galaxies
The demographics of the production and escape of ionizing photons from
UV-faint early galaxies is a key unknown in discovering the primary drivers of
reionization. With the advent of JWST it is finally possible to observe the
rest-frame optical nebular emission from individual sub-L z>3 galaxies to
measure the production of ionizing photons, . Here we study a
sample of 380 z~3-7 galaxies spanning -23 <M < -15.5 (median
M -18) with deep multi-band HST and JWST/NIRCam photometry
covering the rest-UV to optical from the GLASS and UNCOVER JWST surveys. Our
sample includes 109 galaxies with Lyman-alpha emission detected in MUSE
spectroscopy. We use H-alpha fluxes inferred from NIRCam photometry to estimate
the production rate of ionizing photons which do not escape these galaxies
. We find median
, with a broad
intrinsic scatter 0.42 dex, implying a broad range of galaxy properties and
ages in our UV-faint sample. Galaxies detected with Lyman-alpha have ~0.1 dex
higher , which is explained by their higher
H-alpha EW distribution, implying younger ages, higher sSFR and thus more O/B
stars. We find significant trends of increasing
with increasing H-alpha EW, decreasing UV
luminosity, and decreasing UV slope, implying the production of ionizing
photons is enhanced in young, low metallicity galaxies. We find no significant
evidence for sources with very high ionizing escape fraction
(>0.5) in our sample, based on their photometric properties,
even amongst the Lyman-alpha selected galaxies. This work demonstrates that
considering the full distribution of across galaxy
properties is important for assessing the primary drivers of reionization.Comment: 10 pages, 7 figures, submitted to A&
Early results from GLASS-JWST. III: Galaxy candidates at z9-15
We present the results of a first search for galaxy candidates at
z9--15 on deep seven-bands NIRCam imaging acquired as part of the
GLASS-JWST Early Release Science Program on a flanking field of the Frontier
Fields cluster A2744. Candidates are selected via two different renditions of
the Lyman-break technique, isolating objects at z9-11, and z9-15,
respectively, supplemented by photometric redshifts obtained with two
independent codes. We find six color-selected candidates at z9, plus one
additional candidate with photometric redshift z9. In particular,
we identify two bright candidates at that are
unambiguously placed at and , respectively. The
total number of galaxies discovered at is in line with the predictions of
a non-evolving LF. The two bright ones at are unexpected given the
survey volume, although cosmic variance and small number statistics limits
general conclusions. This first search demonstrates the unique power of JWST to
discover galaxies at the high redshift frontier. The candidates are ideal
targets for spectroscopic follow-up in cycle.Comment: Submitted to ApJL, 9 pages, 4 figure
Early results from GLASS-JWST. XX: Unveiling a population of "red-excess'' galaxies in Abell2744 and in the coeval field
We combine JWST/NIRCam imaging and MUSE data to characterize the properties
of galaxies in different environmental conditions in the cluster Abell2744
() and in its immediate surroundings. We investigate how galaxy
colors, morphology and star forming fractions depend on wavelength and on
different parameterizations of environment. Our most striking result is the
discovery of a ``red-excess'' population in F200WF444W colors both in the
cluster regions and the field. These galaxies have normal F115WF150W colors,
but are up to 0.8 mag redder than red sequence galaxies in F200WF444W. They
also have rather blue rest frame BV colors. {Galaxies in the field and at
the cluster virial radius are overall characterized by redder colors, but
galaxies with the largest color deviations are found in the field and in the
cluster core. Several results} suggest that mechanisms taking place in these
regions might be more effective in producing these colors. Looking at their
morphology, many cluster galaxies show signatures consistent with ram pressure
stripping, while field galaxies have features resembling interactions and
mergers. Our hypothesis is that these galaxies are characterized by dust
enshrouded star formation: a JWST/NIRSpec spectrum for one of the galaxies is
dominated by a strong PAH at 3.3, suggestive of dust obscured star
formation. Larger spectroscopic samples are needed to understand if the color
excess is due exclusively to dust-obscured star formation, and the role of
environment in triggering it.Comment: ApJL in pres
Early Results from GLASS-JWST. XIX: A High Density of Bright Galaxies at in the Abell 2744 Region
We report the detection of a high density of redshift galaxies
behind the foreground cluster Abell 2744, selected from imaging data obtained
recently with NIRCam onboard {\it JWST} by three programs -- GLASS-JWST,
UNCOVER, and DDT\#2756. To ensure robust estimates of the lensing magnification
, we use an improved version of our model that exploits the first epoch of
NIRCam images and newly obtained MUSE spectra, and avoids regions with
where the uncertainty may be higher. We detect seven bright
galaxies with demagnified rest-frame mag,
over an area of sq. arcmin. Taking into account photometric
incompleteness and the effects of lensing on luminosity and cosmological
volume, we find that the density of galaxies in the field is
about () larger than the average at mag reported so far. The density is even higher when considering only
the GLASS-JWST data, which are the deepest and the least affected by
magnification and incompleteness. The GLASS-JWST field contains 5 out of 7
galaxies, distributed along an apparent filamentary structure of 2 Mpc in
projected length, and includes a close pair of candidates with mag having a projected separation of only 16 kpc. These findings suggest
the presence of a overdensity in the field. In addition to
providing excellent targets for efficient spectroscopic follow-up observations,
our study confirms the high density of bright galaxies observed in early {\it
JWST} observations, but calls for multiple surveys along independent lines of
sight to achieve an unbiased estimate of their average density and a first
estimate of their clustering.Comment: Accepted for publication in ApJL, 13 pages, 4 figure
Early results from GLASS-JWST. XIV: A spectroscopically confirmed protocluster 650 million years after the Big Bang
We present the spectroscopic confirmation of a protocluster at
behind the galaxy cluster Abell2744 (hereafter A2744-z7p9OD). Using JWST
NIRSpec, we find seven galaxies within a projected radius of 60kpc. Although
the galaxies reside in an overdensity around greater than a random
volume, they do not show strong Lyman-alpha emission. We place 2- upper
limits on the rest-frame equivalent width -AA. Based on the tight
upper limits to the Lyman-alpha emission, we constrain the volume-averaged
neutral fraction of hydrogen in the intergalactic medium to be (68% CI). Using an empirical - relation for
individual galaxies, we estimate that the total halo mass of the system is
. Likewise, the line of sight velocity
dispersion is estimated to be km/s. Using an empirical relation,
we estimate the present-day halo mass of A2744-z7p9OD to be
, comparable to the Coma cluster. A2744-z7p9OD is
the highest redshift spectroscopically confirmed protocluster to date,
demonstrating the power of JWST to investigate the connection between
dark-matter halo assembly and galaxy formation at very early times with
medium-deep observations at hrs total exposure time. Follow-up
spectroscopy of the remaining photometric candidates of the overdensity will
further refine the features of this system and help characterize the role of
such overdensities in cosmic reionization.Comment: The title has been updated to reflect the published numbering; a
minor change has been made to Figure 1 with regard to the MSA shutters on the
rgb stamp image. NASA press release article can be found at:
https://www.nasa.gov/feature/goddard/2023/webb-reveals-early-universe-prequel-to-huge-galaxy-cluste
Roadmap on printable electronic materials for next-generation sensors
The dissemination of sensors is key to realizing a sustainable, ‘intelligent’ world, where everyday objects and environments are equipped with sensing capabilities to advance the sustainability and quality of our lives—e.g., via smart homes, smart cities, smart healthcare, smart logistics, Industry 4.0, and precision agriculture. The realization of the full potential of these applications critically depends on the availability of easy-to-make, low-cost sensor technologies. Sensors based on printable electronic materials offer the ideal platform: they can be fabricated through simple methods (e.g., printing and coating) and are compatible with high-throughput roll-to-roll processing. Moreover, printable electronic materials often allow the fabrication of sensors on flexible/stretchable/biodegradable substrates, thereby enabling the deployment of sensors in unconventional settings. Fulfilling the promise of printable electronic materials for sensing will require materials and device innovations to enhance their ability to transduce external stimuli—light, ionizing radiation, pressure, strain, force, temperature, gas, vapours, humidity, and other chemical and biological analytes. This Roadmap brings together the viewpoints of experts in various printable sensing materials—and devices thereof—to provide insights into the status and outlook of the field. Alongside recent materials and device innovations, the roadmap discusses the key outstanding challenges pertaining to each printable sensing technology. Finally, the Roadmap points to promising directions to overcome these challenges and thus enable ubiquitous sensing for a sustainable, ‘intelligent’ world
Multimodal force and temperature tactile sensor based on a short-channel organic transistor with high sensitivity
Abstract In this manuscript, we report on a novel architecture for the fabrication of highly sensitive multimodal tactile transducers, for the simultaneous detection of temperature and force. Such devices are based on a flexible Organic Charge Modulated Field Effect Transistor (OCMFET) coupled with a pyro/piezoelectric element, namely a commercial film of poly-vinylene difluoride (PVDF). The reduction of the channel length, obtained by employing a low-resolution vertical channel architecture, allowed to maximize the ratio between the sensing area and the transistor’s channel area, a technological approach that allows to considerably enhance both temperature and force sensitivity, while at the same time minimize the sensor’s dimensions. Thanks to the employment of a straightforward, up-scalable, and highly reproducible fabrication process, this solution represents an interesting alternative for all those applications requiring high-density, high-sensitivity sensors such as robotics and biomedical applications
Pentose phosphates in nucleoside interconversion and catabolism
Ribose phosphates are either synthesized through the oxidative branch of the pentose phosphate pathway, or are supplied by nucleoside phosphorylases. The two main pentose phosphates, ribose-5-phosphate and ribose-1-phosphate, are readily interconverted by the action of phosphopentomutase. Ribose-5-phosphate is the direct precursor of 5-phosphoribosyl-1-pyrophosphate, for both de novo and 'salvage' synthesis of nucleotides. Phosphorolysis of deoxyribonucleosides is the main source of deoxyribose phosphates, which are interconvertible, through the action of phosphopentomutase. The pentose moiety of all nucleosides can serve as a carbon and energy source. During the past decade, extensive advances have been made in elucidating the pathways by which the pentose phosphates, arising from nucleoside phosphorolysis, are either recycled, without opening of their furanosidic ring, or catabolized as a carbon and energy source. We review herein the experimental knowledge on the molecular mechanisms by which (a) ribose-1-phosphate, produced by purine nucleoside phosphorylase acting catabolically, is either anabolized for pyrimidine salvage and 5-fluorouracil activation, with uridine phosphorylase acting anabolically, or recycled for nucleoside and base interconversion; (b) the nucleosides can be regarded, both in bacteria and in eukaryotic cells, as carriers of sugars, that are made available though the action of nucleoside phosphorylases. In bacteria, catabolism of nucleosides, when suitable carbon and energy sources are not available, is accomplished by a battery of nucleoside transporters and of inducible catabolic enzymes for purine and pyrimidine nucleosides and for pentose phosphates. In eukaryotic cells, the modulation of pentose phosphate production by nucleoside catabolism seems to be affected by developmental and physiological factors on enzyme levels