28 research outputs found
Warm SiO gas in molecular bullets associated with protostellar outflows
In this paper we present the first SiO multiline analysis (from J=2-1 to
J=11-10) of the molecular bullets along the outflows of the Class 0 sources
L1448-mm and L1157-mm, obtained through observations with IRAM and JCMT. We
have computed the main physical parameters in each bullet and compared them
with other tracers of warm and dense gas and with models for the SiO excitation
in shocks. We find that the bullets close to L1448--mm, associated with high
velocity gas, have higher excitation conditions (n(H2) ~ 10^{6} cm^{-3}, T >
500 K) with respect to the L1157 bullets (n(H2) ~1-5 10^{5} cm^{-3}, T ~
100-300 K). In both the sources, there is a clear evidence of the presence of
velocity components having different excitation conditions, with the denser
and/or warmer gas associated with the gas at the higher speed. In L1448 the
bulk of the emission is due to the high-excitation and high velocity gas, while
in L1157 most of the emission comes from the low excitation gas at ambient
velocity. The observed velocity-averaged line ratios are well reproduced by
shocks with speeds v_s larger than ~ 30 km/s and densities ~ 10^{5} - 10^{6}
cm^{-3}. Plane-parallel shock models, however, fail to predict all the observed
line profiles and in particular the very similar profiles shown by both low and
high excitation lines. The overall observations support the idea that the L1157
clumps are shock interaction events older than the L1448 bullets close to the
driving source. In the latter objects, the velocity structure and the
variations of physical parameters with the velocity resemble very closely those
found in optical/IR jets near the protostar, suggesting that similar launching
and excitation mechanisms are also at the origin of collimated jets seen at
millimetre wavelengths.Comment: 11pages, 9 figures, A&A accepte
Physical parameters for Orion KL from modelling its ISO high resolution far-IR CO line spectrum
As part of the first high resolution far-IR spectral survey of the Orion KL
region (Lerate et al. 2006), we observed 20 CO emission lines with Jup=16 to
Jup=39 (upper levels from approx 752 K to 4294 K above the ground state).
Observations were taken using the Long Wavelength Spectrometer (LWS) on board
the Infrared Space Observatory (ISO), in its high resolution Fabry-Perot (FP)
mode (approx 33 km s). We present here an analysis of the final
calibrated CO data, performed with a more sophisticated modelling technique
than hitherto, including a detailed analysis of the chemistry, and discuss
similarities and differences with previous results. The inclusion of chemical
modelling implies that atomic and molecular abundances are time-predicted by
the chemistry. This provides one of the main differences with previous studies
in which chemical abundances needed to be assumed as initial condition. The
chemistry of the region is studied by simulating the conditions of the
different known components of the KL region: chemical models for a hot core, a
plateau and a ridge are coupled with an accelerated Lambda-iteration
(ALI)radiative transfer model to predict line fluxes and profiles. We conclude
that the CO transitions with 18<Jup<25 mainly arise from a hot core of diameter
0.02 pc and a density of 10 cm rather from the plateau as previous
studies had indicated.Comment: The paper contains 10 pages, 7 figures and 4 tables. MNRAS accepte
Circulating microRNAs in sera correlate with soluble biomarkers of immune activation but do not predict mortality in ART treated individuals with HIV-1 infection: A case control study
Introduction: The use of anti-retroviral therapy (ART) has dramatically reduced HIV-1 associated morbidity and mortality. However, HIV-1 infected individuals have increased rates of morbidity and mortality compared to the non-HIV-1 infected population and this appears to be related to end-organ diseases collectively referred to as Serious Non-AIDS Events (SNAEs). Circulating miRNAs are reported as promising biomarkers for a number of human disease conditions including those that constitute SNAEs. Our study sought to investigate the potential of selected miRNAs in predicting mortality in HIV-1 infected ART treated individuals. Materials and Methods: A set of miRNAs was chosen based on published associations with human disease conditions that constitute SNAEs. This case: control study compared 126 cases (individuals who died whilst on therapy), and 247 matched controls (individuals who remained alive). Cases and controls were ART treated participants of two pivotal HIV-1 trials. The relative abundance of each miRNA in serum was measured, by RTqPCR. Associations with mortality (all-cause, cardiovascular and malignancy) were assessed by logistic regression analysis. Correlations between miRNAs and CD4+ T cell count, hs-CRP, IL-6 and D-dimer were also assessed. Results: None of the selected miRNAs was associated with all-cause, cardiovascular or malignancy mortality. The levels of three miRNAs (miRs -21, -122 and -200a) correlated with IL-6 while miR-21 also correlated with D-dimer. Additionally, the abundance of miRs -31, -150 and -223, correlated with baseline CD4+ T cell count while the same three miRNAs plus miR- 145 correlated with nadir CD4+ T cell count. Discussion: No associations with mortality were found with any circulating miRNA studied. These results cast doubt onto the effectiveness of circulating miRNA as early predictors of mortality or the major underlying diseases that contribute to mortality in participants treated for HIV-1 infection
Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study
Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe
MRI-Based Breast Volumetry—Evaluation of Three Different Software Solutions
As lipofilling of the female breast is becoming more popular in plastic surgery, the use of MRI to assess breast volume has been employed to control postoperative results. Therefore, we sought to evaluate the accuracy of magnetic resonance imaging (MRI)-based breast volumetry software tools by comparing the measurements of silicone implant augmented breasts with the actual implant volume specified by the manufacturer. MRI-based volume analysis was performed in eight bilaterally augmented patients (46 ± 9 years) with three different software programs (Brainlab© I plan 2.6 neuronavigation software; mass analysis, version 5.3, Medis©; and OsiriX© v.3.0.2. 32-bit). The implant volumes analysed by the BrainLab© software had a mean deviation of 2.2 ± 1.7% (r = 0.99) relative to the implanted prosthesis. OsiriX© software analysis resulted in a mean deviation of 2.8 ± 3.0% (r = 0.99) and the Medis© software had a mean deviation of 3.1 ± 3.0% (r = 0.99). Overall, the volumes of all analysed breast implants correlated very well with the real implant volumes. Processing time was 10 min per breast with each system and 30 s (OsiriX©) to 5 min (BrainLab© and Medis©) per silicone implant. MRI-based volumetry is a powerful tool to calculate both native breast and silicone implant volume in situ. All software solutions performed well and the measurements were close to the actual implant sizes. The use of MRI breast volumetry may be helpful in: (1) planning reconstructive and aesthetic surgery of asymmetric breasts, (2) calculating implant size in patients with missing documentation of a previously implanted device and (3) assessing post-operative results objectively