The lower mass function of the young open cluster Blanco 1: from 30 Mjup to 3 Mo

We performed a deep wide field optical survey of the young (~100-150 Myr) open cluster Blanco1 to study its low mass population well down into the brown dwarf regime and estimate its mass function over the whole cluster mass range.The survey covers 2.3 square degrees in the I and z-bands down to I ~ z ~ 24 with the CFH12K camera. Considering two different cluster ages (100 and 150 Myr), we selected cluster member candidates on the basis of their location in the (I,I-z) CMD relative to the isochrones, and estimated the contamination by foreground late-type field dwarfs using statistical arguments, infrared photometry and low-resolution optical spectroscopy. We find that our survey should contain about 57% of the cluster members in the 0.03-0.6 Mo mass range, including 30-40 brown dwarfs. The candidate's radial distribution presents evidence that mass segregation has already occured in the cluster. We took it into account to estimate the cluster mass function across the stellar/substellar boundary. We find that, between 0.03Mo and 0.6Mo, the cluster mass distribution does not depend much on its exact age, and is well represented by a single power-law, with an index alpha=0.69 +/- 0.15. Over the whole mass domain, from 0.03Mo to 3Mo, the mass function is better fitted by a log-normal function with m0=0.36 +/- 0.07Mo and sigma=0.58 +/- 0.06. Comparison between the Blanco1 mass function, other young open clusters' MF, and the galactic disc MF suggests that the IMF, from the substellar domain to the higher mass part, does not depend much on initial conditions. We discuss the implications of this result on theories developed to date to explain the origin of the mass distribution.Comment: 18 pages, 15 figures and 5 tables accepted in A&

Unresolved Rossby and gravity modes in 214 A and F stars showing rotational modulation

Here we report an ensemble study of 214 A- and F-type stars observed by \textit{Kepler}, exhibiting the so-called \textit{hump and spike} periodic signal, explained by Rossby modes (r~modes) -- the \textit{hump} -- and magnetic stellar spots or overstable convective (OsC) modes -- the \textit{spike} -- respectively. We determine the power confined in the non-resolved hump features and find additional gravity~modes (g~modes) humps always occurring at higher frequencies than the spike. Furthermore, we derive projected rotational velocities from FIES, SONG and HERMES spectra for 28 stars and the stellar inclination angle for 89 stars. We find a strong correlation between the spike amplitude and the power in the r and g~modes, which suggests that both types of oscillations are mechanically excited by either stellar spots or OsC modes. Our analysis suggests that stars with a higher power in $m=1$ r~modes humps are more likely to also exhibit humps at higher azimuthal orders ($m$ = 2, 3, or 4). Interestingly, all stars that show g~modes humps are hotter and more luminous than the observed red edge of the $\delta$ Scuti instability strip, suggesting that either magnetic fields or convection in the outer layers could play an important role.Comment: 18 pages, 19 figure

Optical coherence tomography versus intravascular ultrasound to evaluate stent implantation in patients with calcific coronary artery disease

AIMS: Stent underexpansion and malapposition are associated with adverse outcomes following percutaneous coronary intervention, but detection and treatment can be challenging in the presence of extensive coronary artery calcification. Frequency domain optical coherence tomography (FD-OCT) is a novel intravascular imaging technique with greater spatial resolution than intravascular ultrasound (IVUS) but its role in the presence of extensive coronary calcification remains unclear. We sought to determine the utility of FD-OCT compared to IVUS imaging to guide percutaneous coronary intervention in patients with severe calcific coronary artery disease. METHODS: 18 matched IVUS and FD-OCT examinations were evaluated following coronary stent implantation in 12 patients (10 male; mean age 70±7 years) undergoing rotational atherectomy for symptomatic calcific coronary artery disease. RESULTS: In-stent luminal areas were smaller (minimum in-stent area 6.77±2.18 vs 7.19±2.62 mm(2), p<0.05), while reference lumen dimensions were similar with FD-OCT compared with IVUS. Stent malapposition was detected in all patients by FD-OCT and in 10 patients by IVUS. The extent of stent malapposition detected was greater (20% vs 6%, p<0.001) with FD-OCT compared to IVUS. Postdilation increased the in-stent luminal area (minimum in-stent area: 8.15±1.90 vs 7.30±1.62 mm(2), p<0.05) and reduced the extent of stent malapposition (19% vs 34%, p<0.005) when assessed by FD-OCT, but not IVUS. CONCLUSIONS: Acute stent malapposition occurs frequently in patients with calcific coronary disease undergoing rotational atherectomy and stent implantation. In the presence of extensive coronary artery calcification, FD-OCT affords enhanced stent visualisation and detection of malapposition, facilitating improved postdilation stent apposition and minimal luminal areas. TRIAL REGISTRATION NUMBER: NCT02065102

Fraction of Inspired Oxygen During General Anesthesia for Non-Cardiac Surgery:Systematic Review and Meta-Analysis

BACKGROUND: Controversy exists regarding the effects of a high versus a low intraoperative fraction of inspired oxygen (FiO(2)) in adults undergoing general anesthesia. This systematic review and meta‐analysis investigated the effect of a high versus a low FiO(2) on postoperative outcomes. METHODS: PubMed and Embase were searched on March 22, 2022 for randomized clinical trials investigating the effect of different FiO(2) levels in adults undergoing general anesthesia for non‐cardiac surgery. Two investigators independently reviewed studies for relevance, extracted data, and assessed risk of bias. Meta‐analyses were performed for relevant outcomes, and potential effect measure modification was assessed in subgroup analyses and meta‐regression. The evidence certainty was evaluated using GRADE. RESULTS: This review included 25 original trials investigating the effect of a high (mostly 80%) versus a low (mostly 30%) FiO(2). Risk of bias was intermediate for all trials. A high FiO(2) did not result in a significant reduction in surgical site infections (OR: 0.91, 95% CI 0.81–1.02 [p = .10]). No effect was found for all other included outcomes, including mortality (OR = 1.27, 95% CI: 0.90–1.79 [p = .18]) and hospital length of stay (mean difference = 0.03 days, 95% CI −0.25 to 0.30 [p = .84). Results from subgroup analyses and meta‐regression did not identify any clear effect modifiers across outcomes. The certainty of evidence (GRADE) was rated as low for most outcomes. CONCLUSIONS: In adults undergoing general anesthesia for non‐cardiac surgery, a high FiO(2) did not improve outcomes including surgical site infections, length of stay, or mortality. However, the certainty of the evidence was assessed as low

Goal-directed haemodynamic therapy during general anaesthesia for noncardiac surgery:a systematic review and meta-analysis

BACKGROUND: During general anaesthesia for noncardiac surgery, there remain knowledge gaps regarding the effect of goal-directed haemodynamic therapy on patient-centred outcomes. METHODS: Included clinical trials investigated goal-directed haemodynamic therapy during general anaesthesia in adults undergoing noncardiac surgery and reported at least one patient-centred postoperative outcome. PubMed and Embase were searched for relevant articles on March 8, 2021. Two investigators performed abstract screening, full-text review, data extraction, and bias assessment. The primary outcomes were mortality and hospital length of stay, whereas 15 postoperative complications were included based on availability. From a main pool of comparable trials, meta-analyses were performed on trials with homogenous outcome definitions. Certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). RESULTS: The main pool consisted of 76 trials with intermediate risk of bias for most outcomes. Overall, goal-directed haemodynamic therapy might reduce mortality (odds ratio=0.84; 95% confidence interval [CI], 0.64 to 1.09) and shorten length of stay (mean difference=–0.72 days; 95% CI, –1.10 to –0.35) but with low certainty in the evidence. For both outcomes, larger effects favouring goal-directed haemodynamic therapy were seen in abdominal surgery, very high-risk surgery, and using targets based on preload variation by the respiratory cycle. However, formal tests for subgroup differences were not statistically significant. Goal-directed haemodynamic therapy decreased risk of several postoperative outcomes, but only infectious outcomes and anastomotic leakage reached moderate certainty of evidence. CONCLUSIONS: Goal-directed haemodynamic therapy during general anaesthesia might decrease mortality, hospital length of stay, and several postoperative complications. Only infectious postoperative complications and anastomotic leakage reached moderate certainty in the evidence

The N-terminus of CD14 acts to bind apoptotic cells and confers rapid-tethering capabilities on non-myeloid cells:CD14 and rapid tethering of apoptotic cells

Cell death and removal of cell corpses in a timely manner is a key event in both physiological and pathological situations including tissue homeostasis and the resolution of inflammation. Phagocytic clearance of cells dying by apoptosis is a complex sequential process comprising attraction, recognition, tethering, signalling and ultimately phagocytosis and degradation of cell corpses. A wide range of molecules acting as apoptotic cell-associated ligands, phagocyte-associated receptors or soluble bridging molecules have been implicated within this process. The role of myeloid cell CD14 in mediating apoptotic cell interactions with macrophages has long been known though key molecules and residues involved have not been defined. Here we sought to further dissect the function of CD14 in apoptotic cell clearance. A novel panel of THP-1 cell-derived phagocytes was employed to demonstrate that CD14 mediates effective apoptotic cell interactions with macrophages in the absence of detectable TLR4 whilst binding and responsiveness to LPS requires TLR4. Using a targeted series of CD14 point mutants expressed in non-myeloid cells we reveal CD14 residue 11 as key in the binding of apoptotic cells whilst other residues are reported as key for LPS binding. Importantly we note that expression of CD14 in non-myeloid cells confers the ability to bind rapidly to apoptotic cells. Analysis of a panel of epithelial cells reveals that a number naturally express CD14 and that this is competent to mediate apoptotic cell clearance. Taken together these data suggest that CD14 relies on residue 11 for apoptotic cell tethering and it may be an important tethering molecule on so called 'non-professional' phagocytes thus contributing to apoptotic cell clearance in a non-myeloid setting. Furthermore these data establish CD14 as a rapid-acting tethering molecule, expressed in monocytes, which may thus confer responsiveness of circulating monocytes to apoptotic cell derived material. © 2013 Thomas et al

CAF01 Potentiates Immune Responses and Efficacy of an Inactivated Influenza Vaccine in Ferrets

Trivalent inactivated vaccines (TIV) against influenza are given to 350 million people every year. Most of these are non-adjuvanted vaccines whose immunogenicity and protective efficacy are considered suboptimal. Commercially available non-adjuvanted TIV are known to elicit mainly a humoral immune response, whereas the induction of cell-mediated immune responses is negligible. Recently, a cationic liposomal adjuvant (dimethyldioctadecylammonium/trehalose 6,6′-dibehenate, CAF01) was developed. CAF01 has proven to enhance both humoral and cell-mediated immune responses to a number of different experimental vaccine candidates. In this study, we compared the immune responses in ferrets to a commercially available TIV with the responses to the same vaccine mixed with the CAF01 adjuvant. Two recently circulating H1N1 viruses were used as challenge to test the vaccine efficacy. CAF01 improved the immunogenicity of the vaccine, with increased influenza-specific IgA and IgG levels. Additionally, CAF01 promoted cellular-mediated immunity as indicated by interferon-gamma expressing lymphocytes, measured by flow cytometry. CAF01 also enhanced the protection conferred by the vaccine by reducing the viral load measured in nasal washes by RT-PCR. Finally, CAF01 allowed for dose-reduction and led to higher levels of protection compared to TIV adjuvanted with a squalene emulsion. The data obtained in this human-relevant challenge model supports the potential of CAF01 in future influenza vaccines