800 research outputs found
Sodium fraction excretion rate in nocturnal enuresis correlates with nocturnal polyuria and osmolality
Abstract: Purpose: We verify the sodium fraction excretion rate (FE Na) and potassium fraction excretion WE K) rates in monosymptomatic nocturnal enuresis. We also correlate FE Na and FE K to urinary osmolality, nocturnal polyuria and vasopressin in the same population.
Materials and Methods: A total of 438 children 6 to 15 years old (mean age 9.7) presenting with monosymptomatic nocturnal enuresis were recruited from different centers. Inclusion criteria were 3 or greater wet nights a week, no daytime incontinence and no treatment in the previous 2 months. Exclusion criteria were cardiopathy, endocrinopathy, psychiatric problems and urinary tract abnormalities. Micturition chart, diurnal (8 am to 8 pm) and nocturnal (8 pm to 8 am) urine collection, including separate diuresis volumes, (Na, K and Ca) electrolytes and osmolality were evaluated, as well as serum electrolytes, creatinine and nocturnal (4 am) vasopressin. Diurnal and nocturnal FE K and FE Na were calculated. ANOVA test, chi-square test, Student's t test and Pearson correlation test were used for statistical analysis.
Results: Nocturnal polyuria (diurnal to nocturnal diuresis ratio less than 1) was found in 273 children (62.3%, group I and nocturnal urine volumes were normal in 165 with enuresis (37.7%, group 2). Nocturnal FE Na was abnormal in 179 children (40.8%), including 118 in group 1 (43.2%) and 61 in group 2 (36.9%) (chi-square not significant). FE Na was also increased in nocturnal versus daytime diuresis (Student's t test p < 0.001). In group 1 nocturnal FE Na correlated with nocturnal diuresis (Pearson correlation p = 0.003, r = +0.175), while daytime FE Na and nocturnal FE Na correlated with diurnal diuresis (Pearson correlation p = 0.001, r = +0.225 and Pearson correlation p = 0.001, r = +0.209, respectively). In group 2 nocturnal FE Na did not correlate with diuresis (Pearson correlation p = 0.103, r = +0.128) but correlated with vasopressin values (Pearson correlation p = 0.042, r = -0.205). Urine osmolality was reduced in 140 children (31.9%) and correlated with nocturnal diuresis (Pearson correlation p = 0.003, r = -0.321). Vasopressin was decreased in 332 children (75.8%, 62.6% in group 1 and 13.2% in group 2). No significant difference was found between sexes and age of enuretic subgroups.
Conclusions: Nocturnal FE Na correlates with nocturnal diuresis, whereas daytime FE Na does not. FE K in daytime and nighttime diuresis does not statistically differ in nocturnal polyuric and nonpolyuric enuretic groups. Osmolality correlates with nocturnal diuresis, and vasopressin at 4 am was lower in the nocturnal polyuric group. The hypothesis of a subset of enuretic patients presenting with nocturnal polyuria associated with high nocturnal natriuria and low vasopressin values has been confirmed
The AGN content in luminous IR galaxies at z\sim2 from a global SED analysis including Herschel data
We use Herschel-PACS far-infrared data, combined with previous multi-band
information and mid-IR spectra, to properly account for the presence of an
active nucleus and constrain its energetic contribution in luminous infrared
(IR) sources at z\sim2. The sample is composed of 24 sources in the GOODS-South
field, with typical IR luminosity of 10^{12} Lo. Data from the 4 Ms Chandra
X-ray imaging in this field are also used to identify and characterize AGN
emission. We reproduce the observed spectral energy distribution (SED),
decomposed into a host-galaxy and an AGN component. A smooth-torus model for
circum-nuclear dust is used to account for the direct and re-processed
contribution from the AGN. We confirm that galaxies with typical
L_{8-1000um}\sim10^{12}Lo at z\sim2 are powered predominantly by
star-formation. An AGN component is present in nine objects (\sim35% of the
sample) at the 3sigma confidence level, but its contribution to the 8-1000 um
emission accounts for only \sim5% of the energy budget. The AGN contribution
rises to \sim23% over the 5-30 um range (in agreement with Spitzer IRS results)
and to \sim60% over the narrow 2-6 um range. The presence of an AGN is
confirmed by X-ray data for 3 (out of nine) sources, with X-ray spectral
analysis indicating the presence of significant absorption, i.e.
NH\sim10^{23}-10^{24} cm^{-2}. An additional source shows indications of
obscured AGN emission from X-ray data. The comparison between the
mid-IR--derived X-ray luminosities and those obtained from X-ray data suggests
that obscuration is likely present also in the remaining six sources that
harbour an AGN according to the SED-fitting analysis.Comment: 12 pages, including 5 figures. Accepted for publication in MNRA
Compton Thick AGN in the XMM-COSMOS survey
Heavily obscured, Compton Thick (CT, NH>10^24 cm^-2) AGN may represent an
important phase in AGN/galaxy co-evolution and are expected to provide a
significant contribution to the cosmic X-ray background (CXB). Through direct
X-ray spectra analysis, we selected 39 heavily obscured AGN (NH>3x10^23 cm^-2)
in the 2 deg^2 XMM-COSMOS survey. After selecting CT AGN based on the fit of a
simple absorbed two power law model to the XMM data, the presence of CT AGN was
confirmed in 80% of the sources using deeper Chandra data and more complex
models. The final sample of CT AGN comprises 10 sources spanning a large range
of redshift and luminosity. We collected the multi-wavelength information
available for all these sources, in order to study the distribution of SMBH and
host properties, such as BH mass (M_BH), Eddington ratio (\lambda_Edd), stellar
mass (M*), specific star formation rate (sSFR) in comparison with a sample of
unobscured AGN. We find that highly obscured sources tend to have significantly
smaller M_BH and higher \lambda_edd with respect to unobscured ones, while a
weaker evolution in M* is observed. The sSFR of highly obscured sources is
consistent with the one observed in the main sequence of star forming galaxies,
at all redshift. We also present optical spectra, spectral energy distribution
(SED) and morphology for the sample of 10 CT AGN: all the available optical
spectra are dominated by the stellar component of the host galaxy, and a highly
obscured torus component is needed in the SED of the CT sources. Exploiting the
high resolution Hubble-ACS images available, we conclude that these highly
obscured sources have a significantly larger merger fraction with respect to
other X-ray selected samples of AGN. Finally we discuss implications in the
context of AGN/galaxy co-evolutionary models, and compare our results with the
predictions of CXB synthesis models.Comment: Revised version after referee comments. Accepted for publication in
Astronomy & Astrophysics on 25 November 2014. 23 pages, 2 tables, 16 figure
Observing Supermassive Black Holes across cosmic time: from phenomenology to physics
In the last decade, a combination of high sensitivity, high spatial
resolution observations and of coordinated multi-wavelength surveys has
revolutionized our view of extra-galactic black hole (BH) astrophysics. We now
know that supermassive black holes reside in the nuclei of almost every galaxy,
grow over cosmological times by accreting matter, interact and merge with each
other, and in the process liberate enormous amounts of energy that influence
dramatically the evolution of the surrounding gas and stars, providing a
powerful self-regulatory mechanism for galaxy formation. The different
energetic phenomena associated to growing black holes and Active Galactic
Nuclei (AGN), their cosmological evolution and the observational techniques
used to unveil them, are the subject of this chapter. In particular, I will
focus my attention on the connection between the theory of high-energy
astrophysical processes giving rise to the observed emission in AGN, the
observable imprints they leave at different wavelengths, and the methods used
to uncover them in a statistically robust way. I will show how such a combined
effort of theorists and observers have led us to unveil most of the SMBH growth
over a large fraction of the age of the Universe, but that nagging
uncertainties remain, preventing us from fully understating the exact role of
black holes in the complex process of galaxy and large-scale structure
formation, assembly and evolution.Comment: 46 pages, 21 figures. This review article appears as a chapter in the
book: "Astrophysical Black Holes", Haardt, F., Gorini, V., Moschella, U and
Treves A. (Eds), 2015, Springer International Publishing AG, Cha
The main sequence at z ∼ 1.3 contains a sizable fraction of galaxies with compact star formation sizes: a new population of early post-starbursts?
Atacama Large Millimeter/submillimeter Array (ALMA) measurements for 93 Herschel-selected galaxies at 1.1 ≤ z ≤ 1.7 in COSMOS reveal a sizable (>29%) population with compact star formation (SF) sizes, lying on average >×3.6 below the optical stellar mass (M ⋆)─size relation of disks. This sample widely spans the star-forming main sequence (MS), having 108 ≤ M ⋆ ≤ 1011.5 M ☉ and 20 ≤ star formation rate (SFR) ≤ 680 M ☉ yr−1. The 32 size measurements and 61 upper limits are measured on ALMA images that combine observations of CO(5─4), CO(4─3), CO(2─1), and λ obs ∼ 1.1─1.3 mm continuum, all tracing the star-forming molecular gas. These compact galaxies have instead normally extended K band sizes, suggesting strong specific SFR gradients. Compact galaxies comprise the 50 ± 18% of MS galaxies at M ⋆ > 1011 M ☉. This is not expected in standard bimodal scenarios, where MS galaxies are mostly steadily growing extended disks. We suggest that compact MS objects are early post-starburst galaxies in which the merger-driven boost of SF has subsided. They retain their compact SF size until either further gas accretion restores premerger galaxy-wide SF, or until becoming quenched. The fraction of merger-affected SF inside the MS seems thus larger than anticipated and might reach ∼50% at the highest M ⋆. The presence of large galaxies above the MS demonstrates an overall poor correlation between galaxy SF size and specific SFR
The VLA-COSMOS 3 GHz Large Project: continuum data and source catalog release
We present the VLA-COSMOS 3 GHz Large Project based on 384 hours of observations with the Karl G. Jansky Very Large Array (VLA) at 3 GHz (10 cm) toward the two square degree Cosmic Evolution Survey (COSMOS) field. The final mosaic reaches a median rms of 2.3 uJy/beam over the two square degrees at an angular resolution of 0.75". To fully account for the spectral shape and resolution variations across the broad (2 GHz) band, we image all data with a multiscale, multifrequency synthesis algorithm. We present a catalog of 10,830 radio sources down to 5 sigma, out of which 67 are combined from multiple components. Comparing the positions of our 3 GHz sources with those from the Very Long Baseline Array (VLBA)-COSMOS survey, we estimate that the astrometry is accurate to 0.01" at the bright end (signal-to-noise ratio, S/N_3GHz > 20). Survival analysis on our data combined with the VLA-COSMOS 1.4~GHz Joint Project catalog yields an expected median radio spectral index of alpha=-0.7. We compute completeness corrections via Monte Carlo simulations to derive the corrected 3 GHz source counts. Our counts are in agreement with previously derived 3 GHz counts based on single-pointing (0.087 square degrees) VLA data. In summary, the VLA-COSMOS 3 GHz Large Project simultaneously provides the largest and deepest radio continuum survey at high (0.75") angular resolution to date, bridging the gap between last-generation and next-generation surveys
A Multicenter Retrospective Survey regarding Diabetic Ketoacidosis Management in Italian Children with Type 1 Diabetes
We conducted a retrospective survey in pediatric centers belonging to the Italian Society for Pediatric Diabetology and Endocrinology. The following data were collected for all new-onset diabetes patients aged 0-18 years: DKA (pH < 7.30), severe DKA (pH < 7.1), DKA in preschool children, DKA treatment according to ISPAD protocol, type of rehydrating solution used, bicarbonates use, and amount of insulin infused. Records (n = 2453) of children with newly diagnosed diabetes were collected from 68/77 centers (87%), 39 of which are tertiary referral centers, the majority of whom (n = 1536, 89.4%) were diagnosed in the tertiary referral centers. DKA was observed in 38.5% and severe DKA in 10.3%. Considering preschool children, DKA was observed in 72%, and severe DKA in 16.7%. Cerebral edema following DKA treatment was observed in 5 (0.5%). DKA treatment according to ISPAD guidelines was adopted in 68% of the centers. In the first 2 hours, rehydration was started with normal saline in all centers, but with different amount. Bicarbonate was quite never been used. Insulin was infused starting from third hour at the rate of 0.05-0.1 U/kg/h in 72% of centers. Despite prevention campaign, DKA is still observed in Italian children at onset, with significant variability in DKA treatment, underlying the need to share guidelines among centers
Choroidal Changes in Blood Flow in Patients with Intermediate AMD after Oral Dietary Supplement Based on Astaxanthin, Bromelain, Vitamin D3, Folic Acid, Lutein, and Antioxidants
Background and Objectives: The aim of this study was to investigate the impact of oral administration of the combination of astaxanthin (AXT), lutein, folic acid, vitamin D3, and bromelain with antioxidants on choroidal blood flow in patients with age-related intermediate macular degeneration (AMD). Materials and Methods: Patients affected by intermediate AMD and treated with daily oral nutritional supplement with AXT, bromelain, vitamin D3, folic acid, lutein, and antioxidants for a period of at least 6 months were included in this retrospective study. A control group homogenous for age and sex was also included in the analysis. All participants underwent a complete ophthalmologic examination, spectral domain optical coherence tomography (SD-OCT), and optical coherence tomography angiography (OCTA) evaluation. Outcome measures were choroidal thickness (CHT) and choriocapillary vessel density (CCVD) after six months of AXT assumption. Results: CCVD values showed statistically significant difference between cases and controls at baseline (p < 0.001) and in the cases during follow-up (p < 0.001). The CHT measurements showed statistically significant difference between cases and controls (p = 0.002) and in the cases during follow-up (p < 0.001). Conclusions: The combined use of structural OCT and OCTA allows for a detailed analysis in vivo of perfusion parameters of the choriocapillaris and choroid and evaluation of changes of choroidal blood flow after oral nutritional supplements that affect blood flow velocity
An Eddington ratio-driven origin for the LX- M∗relation in quiescent and star-forming active galaxies
A mild correlation exists in active galaxies between the mean black hole accretion, as traced by the mean X-ray luminosity and the host galaxy stellar mass M∗, characterised by a normalization steadily decreasing with cosmic time and lower in more quiescent galaxies. We create comprehensive semi-empirical mock catalogues of active black holes to pin down which parameters control the shape and evolution of the - M∗ relation of X-ray-detected active galaxies. We find that the normalization of the - M∗ relation is largely independent of the fraction of active galaxies (the duty cycle), but strongly dependent on the mean Eddington ratio, when adopting a constant underlying MBH - M∗ relation as suggested by observational studies. The data point to a decreasing mean Eddington ratio with cosmic time and with galaxy stellar mass at fixed redshift. Our data can be reproduced by black holes and galaxies evolving on similar MBH - M∗ relations but progressively decreasing their average Eddington ratios, mean X-ray luminosities, and specific star formation rates, when moving from the starburst to the quiescent phase. Models consistent with the observed - M∗ relation and independent measurements of the mean Eddington ratios are characterised by MBH - M∗ relations lower than those derived from dynamically measured local black holes. Our results point to the - M∗ relation as a powerful diagnostic to: (1) probe black hole-galaxy scaling relations and the level of accretion on to black holes; (2) efficiently break the degeneracies between duty cycles and accretion rates in cosmological models of black holes
The Herschel* PEP-HERMES Luminosity Function- I. Probing the Evolution of PACS Selected Galaxies to z approx. equal to 4
We exploit the deep and extended far-IR data sets (at 70, 100 and 160 m) of the Herschel Guaranteed Time Observation (GTO) PACS Evolutionary Probe (PEP) Survey, in combination with the Herschel Multi-tiered Extragalactic Survey data at 250, 350 and 500 m, to derive the evolution of the rest-frame 35-, 60-, 90- and total infrared (IR) luminosity functions (LFs) up to z 4.We detect very strong luminosity evolution for the total IR LF (LIR (1 + z)(sup 3.55 +/- 0.10) up to z 2, and (1 + z)(sup 1.62 +/- 0.51) at 2 less than z less than approximately 4) combined with a density evolution ( (1 + z)(sup 0.57 +/- 0.22) up to z 1 and (1 + z)(sup 3.92 +/- 0.34) at 1 less than z less than approximately 4). In agreement with previous findings, the IR luminosity density (IR) increases steeply to z 1, then flattens between z 1 and z 3 to decrease at z greater than approximately 3. Galaxies with different spectral energy distributions, masses and specific star formation rates (SFRs) evolve in very different ways and this large and deep statistical sample is the first one allowing us to separately study the different evolutionary behaviours of the individual IR populations contributing to IR. Galaxies occupying the well-established SFR-stellar mass main sequence (MS) are found to dominate both the total IR LF and IR at all redshifts, with the contribution from off-MS sources (0.6 dex above MS) being nearly constant (20 per cent of the total IR) and showing no significant signs of increase with increasing z over the whole 0.8 < z <2.2 range. Sources with mass in the range 10 log(M/solar mass) 11 are found to dominate the total IR LF, with more massive galaxies prevailing at the bright end of the high-z (greater than approximately 2) LF. A two-fold evolutionary scheme for IR galaxies is envisaged: on the one hand, a starburst-dominated phase in which the Super Massive Black Holes (SMBH) grows and is obscured by dust (possibly triggered by a major merging event), is followed by an AGN-dominated phase, then evolving towards a local elliptical. On the other hand, moderately star-forming galaxies containing a low-luminosity AGN have various properties suggesting they are good candidates for systems in a transition phase preceding the formation of steady spiral galaxies
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