42 research outputs found
Sub-arcsecond imaging of SiO in the HH 211 protostellar jet
We present images of the HH 211 molecular jet in the SiO v=0, J=1-0 line at
43 GHz made with the Very Large Array at approximately 0.5 arcsec resolution.
The SiO emission appears to trace primarily internal bowshocks in the outflow,
suggesting that the dust and molecular gas are accelerated via prompt
entrainment at internal working surfaces in the jet. There is also some
evidence for limb-brightening of the SiO emission, indicating that SiO emission
may also arise from entrainment in the jet's boundary layer. Excitation
temperatures of >~150-200 K are inferred from the SiO emission. Enhancements in
the SiO abundance of ~10^6 over interstellar values are observed, and the
possible origin of the SiO is discussed.Comment: 14 pages, 4 figures. Needs aastex, epsfig, times.sty. To appear in
the Astrophysical Journal, July 200
A survey of SiO 5-4 emission towards outflows from low-luminosity protostellar candidates
We have observed the SiO J=5--4 line towards a sample of 25 low-luminosity
(L* < 10^3 Lsun) protostellar outflow systems. The line was detected towards 7
of the 25 sources, a detection rate of 28 per cent. The majority (5 out of 7)
of sources detected were of class 0 status. We detected a higher fraction of
class 0 sources compared with the class I and II sources, although given the
small numbers involved the significance of this result should be regarded as
tentative. Most of the detected sources showed emission either at or close to
the central position, coincident with the protostar. In four cases (HH211,
HH25MMS, V-380 OriNE and HH212) emission was also detected at positions away
from the center, and was stronger than that observed at the centre position.
SiO abundances of 10^(-8) to 8x10^(-7) are derived from LTE analysis. For 2
sources we have additional transitions which we use to conduct statistical
equilibrium modeling to estimate the gas density in the SiO-emitting regions.
For HH25MMS these results suggest that the SiO emission arises in a
higher-density region than the methanol previously observed. We find that the
most likely explanation for the preferential detection of SiO emission towards
class 0 sources is the greater density of those environments, reinforced by
higher shock velocities. We conclude that while not all class 0 sources exhibit
SiO emission, SiO emission is a good signpost for the presence of class 0
sources.Comment: 21 pages, inc 10 B&W figures. Uses emulateapj5.sty. Accepted for
publication in ApJ, scheduled for 1 March 2004 issu
Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study
Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe
PRECARITE ET INFECTION PAR LE VIRUS DE L'IMMUNODEFICIENCE HUMAINE (ETUDE DE 22 CAS)
PARIS7-Villemin (751102101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF
Challenges and opportunities for oral pre-exposure prophylaxis in the prevention of HIV infection: where are we in Europe?
International audienceFollowing US Food and Drugs Administration approval in July 2012 of daily oral tenofovir and emtricitabine for pre-exposure prophylaxis (PrEP) to prevent HIV infection in high-risk individuals in the USA, there has been much controversy about the implementation of this PrEP regimen in other countries throughout the world, and in Europe in particular. In this review, we focus on the challenges and opportunities of a daily oral PrEP regimen to curb the rising incidence of HIV infection in high-risk groups, and particularly in men who have sex with men. A number of issues would need to be addressed before PrEP could be implemented, including assessing the real effectiveness and cost-effectiveness of daily PrEP, the sustainability of daily adherence, the risk of selecting resistance, the long-term safety, and the risk of change in sexual behavior that might offset the benefit of PrEP. Alternatives to a daily oral PrEP regimen are being explored
Inflammatory Markers During Early Treatment of Seroconverters in a Randomized Placebo-Controlled Trial of PrEP (ANRS-IPERGAY)
International audienceHIV-related inflammation is associated with poor outcomes. We describe inflammatory biomarkers in 17 participants in a pre-exposure prophylaxis trial who seroconverted with very early initiation of antiretroviral therapy. Inflammation peaked at the time of HIV infection and returned to baseline within 6-12 months. Starting antiretroviral therapy very early could help mitigate long-lasting HIV-related inflammation
Coverage of Sex Acts by Event-Driven Pre-exposure Prophylaxis: A Sub-Study of the ANRS IPERGAY Trial
Pleasure and PrEP: Pleasure-Seeking Plays a Role in Prevention Choices and Could Lead to PrEP Initiation
International audiencePleasure-seeking plays a role in prevention (means choices and use), and in the sexual quality of life of men who have sex with men (MSM). Since HIV is a major threat to MSM health, new means of prevention, like pre-exposure prophylaxis (PrEP), must meet the needs of MSM to be fully efficient. Using a psychosocial approach, we examined how pleasure-seeking plays a role in participation of MSM in “ANRS-IPERGAY,” a community-based trial on sexual health which included sexual on-demand PrEP. Thirteen semistructured collective interviews were conducted with 45 participants. First, we analyzed participants’ search for new prevention means due to previous failures in condom use. We found that participants perceived condoms as a barrier—both materially and symbolically—to pleasure and desire, causing anxiety and stress considering sexual intercourse. Second, we explored representations and attitudes concerning pleasure within the context of PrEP. We found that PrEP allowed participants to freely choose their desired sexual positions and to better enjoy intimacy. Third, we studied the sexual quality of life for PrEP users in ANRS-IPERGAY and found an improvement. Thanks to the community-based design of the trial, this new prevention tool became a means to develop agency and empowerment for participants, not only in negotiating individual prevention but also in opposing the normative and stigmatizing discourse on sexuality and HIV. In conclusion, pleasure-seeking appears to be an essential element of sexual fulfillment that needs to be integrated as a positive notion in the study of HIV prevention
Becoming adherent to a preventive treatment for HIV: a qualitative approach
International audienc
Effect of On-Demand Oral Pre-exposure Prophylaxis With Tenofovir/Emtricitabine on Herpes Simplex Virus-1/2 Incidence Among Men Who Have Sex With Men: A Substudy of the ANRS IPERGAY Trial
International audienceWe evaluated the impact of on-demand oral tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) for pre-exposure prophylaxis (PrEP) on herpes simplex virus (HSV)-1/2 incidence among men who have sex with men (MSM) enrolled in the ANRS IPERGAY trial. Serum samples were tested at baseline and at the last visit for HSV-1/2 antibodies. Overall HSV-1 incidence was 11.7 per 100 person-years; 16.2 and 7.8 per 100 person-years in the TDF/FTC and placebo arm, respectively (P = .19). Overall HSV-2 incidence was 7.6 per 100 person-years; 8.1 and 7.0 per 100 person-years in the TDF/FTC and placebo arm, respectively (P = .75). On-demand oral PrEP with TDF/FTC failed to reduce HSV-1/2 incidence in this population