521 research outputs found
Characterizing K2 planet discoveries : a super-Earth transiting the bright K dwarf HIP 116454
We report the first planet discovery from the two-wheeled Kepler (K2) mission: HIP 116454 b. The host star HIP 116454 is a bright (V = 10.1, K = 8.0) K1 dwarf with high proper motion and a parallax-based distance of 55.2 ± 5.4 pc. Based on high-resolution optical spectroscopy, we find that the host star is metal-poor with [Fe/H] =–0.16 ± 0.08 and has a radius R = 0.716 ± 0.024 R ☉ and mass M = 0.775 ± 0.027 M ☉. The star was observed by the Kepler spacecraft during its Two-Wheeled Concept Engineering Test in 2014 February. During the 9 days of observations, K2 observed a single transit event. Using a new K2 photometric analysis technique, we are able to correct small telescope drifts and recover the observed transit at high confidence, corresponding to a planetary radius of pR = 2.53 ± 0.18 R ⊕. Radial velocity observations with the HARPS-N spectrograph reveal a 11.82 ± 1.33 M ⊕ planet in a 9.1 day orbit, consistent with the transit depth, duration, and ephemeris. Follow-up photometric measurements from the MOST satellite confirm the transit observed in the K2 photometry and provide a refined ephemeris, making HIP 116454 b amenable for future follow-up observations of this latest addition to the growing population of transiting super-Earths around nearby, bright stars.Publisher PDFPeer reviewe
The Kepler-10 planetary system revisited by HARPS-N: A hot rocky world and a solid Neptune-mass planet
Kepler-10b was the first rocky planet detected by the Kepler satellite and
con- firmed with radial velocity follow-up observations from Keck-HIRES. The
mass of the planet was measured with a precision of around 30%, which was
insufficient to constrain models of its internal structure and composition in
detail. In addition to Kepler-10b, a second planet transiting the same star
with a period of 45 days was sta- tistically validated, but the radial
velocities were only good enough to set an upper limit of 20 Mearth for the
mass of Kepler-10c. To improve the precision on the mass for planet b, the
HARPS-N Collaboration decided to observe Kepler-10 intensively with the HARPS-N
spectrograph on the Telescopio Nazionale Galileo on La Palma. In to- tal, 148
high-quality radial-velocity measurements were obtained over two observing
seasons. These new data allow us to improve the precision of the mass
determina- tion for Kepler-10b to 15%. With a mass of 3.33 +/- 0.49 Mearth and
an updated radius of 1.47 +0.03 -0.02 Rearth, Kepler-10b has a density of 5.8
+/- 0.8 g cm-3, very close to the value -0.02 predicted by models with the same
internal structure and composition as the Earth. We were also able to determine
a mass for the 45-day period planet Kepler-10c, with an even better precision
of 11%. With a mass of 17.2 +/- 1.9 Mearth and radius of 2.35 +0.09 -0.04
Rearth, -0.04 Kepler-10c has a density of 7.1 +/- 1.0 g cm-3. Kepler-10c
appears to be the first strong evidence of a class of more massive solid
planets with longer orbital periods.Comment: 44 pages, 8 figures, accepted for publication in Ap
Baseline Systemic Oral Corticosteroid Use in Patients with Asthma Initiating Dupilumab Treatment in the Real World:From the RAPID Global Registry
Baseline Characteristics of Dupilumab-Treated Patients with Asthma in the Real World:The RAPID Global Registry
Introduction: Patients with uncontrolled, moderate-to-severe asthma have a higher risk for exacerbations, negatively impacting lung function and quality of life. Dupilumab, a fully human monoclonal antibody, blocks interleukins 4 and 13, key and central drivers of type 2 inflammation. Dupilumab has been effective in the treatment of certain types of moderate-to-severe asthma across several clinical trials. We describe the characteristics of patients enrolled in RAPID, a global prospective registry, who initiated dupilumab (primary indication: asthma) in a real-world clinical setting. Methods: A total of 205 patients (aged ≥ 12 years) were enrolled between March 2020 and October 2021 and are included in this analysis. Data are shown as mean (SD) unless stated otherwise. Results: Patients were aged 50.1 (17.4) years and were mostly female (65.4%) and white (74.1%). At enrollment, 24.4% reported being current/former smokers and 86.8% had moderate-to-severe asthma (Global Initiative for Asthma steps 3–5). A mean (SD) of 4.4 (6.4) severe asthma exacerbations were reported in the year before enrolling in the registry in 78 of 152 patients with available data. Patients had reduced lung function [pre-bronchodilator forced expiratory volume in 1 s (FEV1): 2.3 (1.1) L; pre-bronchodilator percent predicted FEV1: 70.3 (20.3) %] and poor asthma control [6-item Asthma Control Questionnaire: 2.4 (1.2); Asthma Quality of Life Questionnaire: 4.1 (1.3)]. The median (Q1–Q3) blood eosinophil count was 305 (200–695) cells/µL and the mean (SD) fractional exhaled nitric oxide levels were 42 (35) ppb (range: 4–186 ppb). Conclusion: Our findings suggest that most patients who enrolled in RAPID and initiated dupilumab in real-world clinical settings had a high disease burden, despite receiving current standard-of-care treatment at enrollment.</p
Reverse engineering of TLX oncogenic transcriptional networks identifies RUNX1 as tumor suppressor in T-ALL
The TLX1 and TLX3 transcription factor oncogenes have a key role in the pathogenesis of T cell acute lymphoblastic leukemia (T-ALL)(1,2). Here we used reverse engineering of global transcriptional networks to decipher the oncogenic regulatory circuit controlled by TLX1 and TLX3. This systems biology analysis defined T cell leukemia homeobox 1 (TLX1) and TLX3 as master regulators of an oncogenic transcriptional circuit governing T-ALL. Notably, a network structure analysis of this hierarchical network identified RUNX1 as a key mediator of the T-ALL induced by TLX1 and TLX3 and predicted a tumor-suppressor role for RUNX1 in T cell transformation. Consistent with these results, we identified recurrent somatic loss-of-function mutations in RUNX1 in human T-ALL. Overall, these results place TLX1 and TLX3 at the top of an oncogenic transcriptional network controlling leukemia development, show the power of network analyses to identify key elements in the regulatory circuits governing human cancer and identify RUNX1 as a tumor-suppressor gene in T-ALL
Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks
A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at root s = 8 TeV. The data correspond to an integrated luminosity of 19.7 fb(-1). The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t (t) over bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 confidence level for the product of the production cross section and branching fraction sigma(gg -> X) B(X -> HH -> b (b) over barb (b) over bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with amass scale Lambda(R) = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV
Validation of a Third Planet in the LHS 1678 System
The nearby LHS 1678 (TOI-696) system contains two confirmed planets and a
wide-orbit, likely-brown-dwarf companion, which orbit an M2 dwarf with a unique
evolutionary history. The host star occupies a narrow "gap" in the HR diagram
lower main sequence, associated with the M dwarf fully convective boundary and
long-term luminosity fluctuations. This system is one of only about a dozen M
dwarf multi-planet systems to date that hosts an ultra-short period planet
(USP). Here we validate and characterize a third planet in the LHS 1678 system
using TESS Cycle 1 and 3 data and a new ensemble of ground-based light curves.
LHS 1678 d is a 0.98 +/-0.07 Earth radii planet in a 4.97-day orbit, with an
insolation flux of 9.1 +0.9/-0.8 Earth insolations. These properties place it
near 4:3 mean motion resonance with LHS 1678 c and in company with LHS 1678 c
in the Venus zone. LHS 1678 c and d are also twins in size and predicted mass,
making them a powerful duo for comparative exoplanet studies. LHS 1678 d joins
its siblings as another compelling candidate for atmospheric measurements with
the JWST and mass measurements using high-precision radial velocity techniques.
Additionally, USP LHS 1678 b breaks the "peas-in-a-pod" trend in this system,
although additional planets could fill in the "pod" beyond its orbit. LHS
1678's unique combination of system properties and their relative rarity among
the ubiquity of compact multi-planet systems around M dwarfs makes the system a
valuable benchmark for testing theories of planet formation and evolution.Comment: Published in The Astronomical Journal, 7 Figures, 4 Tables, 13 Page
CEACAM1 Negatively Regulates IL-1β Production in LPS Activated Neutrophils by Recruiting SHP-1 to a SYK-TLR4-CEACAM1 Complex
LPS-activated neutrophils secrete IL-1β by activation of TLR-4. Based on studies in macrophages, it is likely that ROS and lysosomal destabilization regulated by Syk activation may also be involved. Since neutrophils have abundant expression of the ITIM-containing co-receptor CEACAM1 and Gram-negative bacteria such as Neisseria utilize CEACAM1 as a receptor that inhibits inflammation, we hypothesized that the overall production of IL-1β in LPS treated neutrophils may be negatively regulated by CEACAM1. We found that LPS treated neutrophils induced phosphorylation of Syk resulting in the formation of a complex including TLR4, p-Syk, and p-CEACAM1, which in turn, recruited the inhibitory phosphatase SHP-1. LPS treatment leads to ROS production, lysosomal damage, caspase-1 activation and IL-1β secretion in neutrophils. The absence of this regulation in Ceacam1−/− neutrophils led to hyper production of IL-1β in response to LPS. The hyper production of IL-1β was abrogated by in vivo reconstitution of wild type but not ITIM-mutated CEACAM1 bone marrow stem cells. Blocking Syk activation by kinase inhibitors or RNAi reduced Syk phosphorylation, lysosomal destabilization, ROS production, and caspase-1 activation in Ceacam1−/− neutrophils. We conclude that LPS treatment of neutrophils triggers formation of a complex of TLR4 with pSyk and pCEACAM1, which upon recruitment of SHP-1 to the ITIMs of pCEACAM1, inhibits IL-1β production by the inflammasome. Thus, CEACAM1 fine-tunes IL-1β production in LPS treated neutrophils, explaining why the additional utilization of CEACAM1 as a pathogen receptor would further inhibit inflammation
A single dose of pegfilgrastim compared with daily filgrastim for supporting neutrophil recovery in patients treated for low-to-intermediate risk acute myeloid leukemia: results from a randomized, double-blind, phase 2 trial
Background: Patients with acute myeloid leukemia (AML) are often neutropenic as a result of their disease. Furthermore, these patients typically experience profound neutropenia following induction and/or consolidation chemotherapy and this may result in serious, potentially life-threatening, infection. This randomized, double-blind, phase 2 clinical trial compared the efficacy and tolerability of pegfilgrastim with filgrastim for assisting neutrophil recovery following induction and consolidation chemotherapy for de novo AML in patients with low-to-intermediate risk cytogenetics. Methods: Patients (n = 84) received one or two courses of standard induction chemotherapy (idarubicin + cytarabine), followed by one course of consolidation therapy (high-dose cytarabine) if complete remission was achieved. They were randomized to receive either single-dose pegfilgrastim 6 mg or daily filgrastim 5 μg/kg, beginning 24 hours after induction and consolidation chemotherapy. Results: The median time to recovery from severe neutropenia was 22.0 days for both pegfilgrastim (n = 42) and filgrastim (n = 41) groups during Induction 1 (difference 0.0 days; 95% CI: -1.9 to 1.9). During Consolidation, recovery occurred after a median of 17.0 days for pegfilgrastim versus 16.5 days for filgrastim (difference 0.5 days; 95% CI: -1.1 to 2.1). Therapeutic pegfilgrastim serum concentrations were maintained throughout neutropenia. Pegfilgrastim was well tolerated, with an adverse event profile similar to that of filgrastim. Conclusion: These data suggest no clinically meaningful difference between a single dose of pegfilgrastim and multiple daily doses of filgrastim for shortening the duration of severe neutropenia following chemotherapy in de novo AML patients with low-to-intermediate risk cytogenetics
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