171 research outputs found

    Optimization of Cannula Visibility during Ultrasound-Guided Subclavian Vein Catheterization, via a Longitudinal Approach, by Implementing Echogenic Technology

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    Objective. One limitation of ultrasound-guided vascular access is the technical challenge of visualizing the cannula during insertion into the vessel. We hypothesized that the use of an echogenic vascular cannula (EC) would improve visualization when compared with a nonechogenic vascular cannula (NEC) during real-time ultrasound-guided subclavian vein (SCV) cannulation in the ICU. Material and Methods. Eighty mechanically ventilated patients were prospectively enrolled in a randomized study that was conducted in a medical-surgical ICU. Forty patients underwent EC and 40 patients were randomized to NEC. The procedure was ultrasound-guided SCV cannulation via the infraclavicular approach on the longitudinal axis. Results. The EC group exhibited increased cannula visibility as compared to the NEC group (92%±3% versus 85 ± 7%, resp., P < 0.01). There was strong agreement between the procedure operators and independent observers (k = 0.9, 95% confidence intervals assessed by bootstrap analysis = 0.87 to 0.93; P < 0.01). Access time (12.1 s ± 6.5 versus 18.9 s ± 10.9) and the perceived technical difficulty of the ultrasound method (4.5 ± 1.5 versus 7.5 ± 1.5) were both decreased in the EC group compared to the NEC group (P < 0.05). Conclusions. Echogenic technology significantly improved cannula visibility and decreased access time and technical complexity optimizing thus real-time ultrasound-guided SCV cannulation via a longitudinal approach

    Echogenic Technology Improves Cannula Visibility during Ultrasound-Guided Internal Jugular Vein Catheterization via a Transverse Approach

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    Objective. Echogenic technology has recently enhanced the ability of cannulas to be visualized during ultrasound-guided vascular access. We studied whether the use of an EC could improve visualization if compared with a nonechogenic vascular cannula (NEC) during real-time ultrasound-guided internal jugular vein (IJV) cannulation in the intensive care unit (ICU). Material and Methods. We prospectively enrolled 80 mechanically ventilated patients who required central venous access in a randomized study that was conducted in two medical-surgical ICUs. Forty patients underwent EC and 40 patients were randomized to NEC. The procedure was ultrasound-guided IJV cannulation via a transverse approach. Results. The EC group exhibited increased visibility as compared to the NEC group (88%  ± 8% versus 20%  ± 15%, resp. P < 0.01). There was strong agreement between the procedure operators and independent observers (k = 0.9; 95% confidence intervals assessed by bootstrap analysis = 0.87–0.95; P < 0.01). Access time (5.2 s ± 2.5 versus 10.6 s ± 5.7) and mechanical complications were both decreased in the EC group compared to the NEC group (P < 0.05). Conclusion. Echogenic technology significantly improved cannula visibility and decreased access time and mechanical complications during real-time ultrasound-guided IJV cannulation via a transverse approach

    A Direct Comparison between the use of Double Gray and Multiwavelength Radiative Transfer in a General Circulation Model with and without Radiatively Active Clouds

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    Inhomogeneous cloud formation and wavelength-dependent phenomena are expected to shape hot Jupiter atmospheres. We present a General Circulation Model (GCM) with multiwavelength "picket fence" radiative transfer and radiatively active, temperature dependent clouds, and compare the results to a double gray routine. The double gray method inherently fails to model polychromatic effects in hot Jupiter atmospheres, while picket fence captures these non-gray aspects and performs well compared to fully wavelength-dependent methods. We compare both methods with radiatively active clouds and cloud-free models, assessing the limitations of the double gray method. Although there are broad similarities, the picket fence models have larger day-night side temperature differences, non-isothermal upper atmospheres, and multiwavelength effects in the presence of radiatively active clouds. We model the well-known hot Jupiters HD 189733 b and HD 209458 b. For the hotter HD 209458 b, the picket fence method prevents clouds from thermostating dayside temperatures, resulting in hotter upper atmospheres and the dissipation of dayside clouds. Differences in the temperature structures are then associated with nuanced differences in the circulation patterns and clouds. Models of the cooler HD 189733 b have global cloud coverage, regardless of radiative transfer scheme, whereas there are larger differences in the models of HD 209458 b, particularly in the extent of the partial cloud coverage on its dayside. This results in minor changes to the thermal and reflected light phase curves of HD 189733 b, but more significant differences for the picket fence and double gray versions of HD 209458 b.Comment: Submitted to ApJ, 31 page

    A Non-Detection of Iron in the First High-Resolution Emission Study of the Lava Planet 55 Cnc e

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    Close-in lava planets represent an extreme example of terrestrial worlds, but their high temperatures may allow us to probe a diversity of crustal compositions. The brightest and most well-studied of these objects is 55 Cancri e, a nearby super-Earth with a remarkably short 17-hour orbit. However, despite numerous studies, debate remains about the existence and composition of its atmosphere. We present upper limits on the atmospheric pressure of 55 Cnc e derived from high-resolution time-series spectra taken with Gemini-N/MAROON-X. Our results are consistent with current crustal evaporation models for this planet which predict a thin \sim 100 mbar atmosphere. We conclude that, if a mineral atmosphere is present on 55 Cnc e, the atmospheric pressure is below 100 mbar.Comment: Accepted to the AJ. 7 pages, 5 figure

    Characteristics of Local Health Departments Associated with Implementation of Electronic Health Records and Other Informatics Systems

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    Objective: Assessing local health departments’ (LHDs’) informatics capacities is important, especially within the context of broader, systems-level health reform. We assessed a nationally representative sample of LHDs’ adoption of information systems and the factors associated with adoption and implementation by examining electronic health records, health information exchange, immunization registry, electronic disease reporting system, and electronic laboratory reporting. Methods: We used data from the National Association of County and City Health Officials’ 2013 National Profile of LHDs. We performed descriptive statistics and multinomial logistic regression for the five implementation-oriented outcome variables of interest, with three levels of implementation (implemented, plan to implement, and no activity). Independent variables included infrastructural and financial capacity and other characteristics associated with informatics capacity. Results: Of 505 LHDs that responded to the survey, 69 (13.5%) had implemented health information exchanges, 122 (22.2%) had implemented electronic health records, 245 (47.5%) had implemented electronic laboratory reporting, 368 (73.0%) had implemented an electronic disease reporting system, and 416 (83.8%) had implemented an immunization registry. LHD characteristics associated with health informatics adoption included provision of greater number of clinical services, greater per capita public health expenditures, health information systems specialists on staff, larger population size, decentralized governance system, one or more local boards of health, metropolitan jurisdiction, and top executive with more years in the job. Conclusion: Many LHDs lack health informatics capacity, particularly in smaller, rural jurisdictions. Cross-jurisdictional sharing, investment in public health informatics infrastructure, and additional training may help address these shortfalls

    A hot sub-Neptune in the desert and a temperate super-Earth around faint M dwarfs: Color validation of TOI-4479b and TOI-2081b

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    We report the discovery and validation of two TESS exoplanets orbiting faint M dwarfs: TOI-4479b and TOI-2081b. We have jointly analyzed space (TESS mission) and ground based (MuSCAT2, MuSCAT3 and SINISTRO instruments) lightcurves using our multi-color photometry transit analysis pipeline. This allowed us to compute contamination limits for both candidates and validate them as planet-sized companions. We found TOI-4479b to be a sub-Neptune-sized planet (Rp=2.820.63+0.65 RR_{p}=2.82^{+0.65}_{-0.63}~\rm R_{\oplus}) and TOI-2081b to be a super-Earth-sized planet (Rp=2.040.54+0.50 RR_{p}=2.04^{+0.50}_{-0.54}~\rm R_{\oplus}). Furthermore, we obtained that TOI-4479b, with a short orbital period of 1.158900.00001+0.00002 days1.15890^{+0.00002}_{-0.00001}~\rm days, lies within the Neptune desert and is in fact the largest nearly ultra-short period planet around an M dwarf known to date. These results make TOI-4479b rare among the currently known exoplanet population around M dwarf stars, and an especially interesting target for spectroscopic follow-up and future studies of planet formation and evolution.Comment: Accepted for publication in Astronomy&Astrophysic

    TOI-2266 b : a keystone super-Earth at the edge of the M dwarf radius valley

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    We validate the Transiting Exoplanet Survey Satellite (TESS) object of interest TOI-2266.01 (TIC 348911) as a small transiting planet (most likely a super-Earth) orbiting a faint M5 dwarf (V=16.54) on a 2.33~d orbit. The validation is based on an approach where multicolour transit light curves are used to robustly estimate the upper limit of the transiting object's radius. Our analysis uses SPOC-pipeline TESS light curves from Sectors 24, 25, 51, and 52, simultaneous multicolour transit photometry observed with MuSCAT2, MuSCAT3, and HiPERCAM, and additional transit photometry observed with the LCOGT telescopes. TOI-2266 b is found to be a planet with a radius of 1.54 ± 0.09,R⊕, which locates it at the edge of the transition zone between rocky planets, water-rich planets, and sub-Neptunes (the so-called M~dwarf radius valley). The planet is amenable to ground-based radial velocity mass measurement with red-sensitive spectrographs installed in large telescopes, such as MAROON-X and Keck Planet Finder (KPF), which makes it a valuable addition to a relatively small population of planets that can be used to probe the physics of the transition zone. Further, the planet's orbital period of 2.33 days places it inside a 'keystone planet' wedge in the period-radius plane where competing planet formation scenarios make conflicting predictions on how the radius valley depends on the orbital period. This makes the planet also a welcome addition to the small population of planets that can be used to test small-planet formation scenarios around M~dwarfs.Peer reviewe

    TOI-969: a late-K dwarf with a hot mini-Neptune in the desert and an eccentric cold Jupiter

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    Context. The current architecture of a given multi-planetary system is a key fingerprint of its past formation and dynamical evolution history. Long-term follow-up observations are key to complete their picture. Aims. In this paper, we focus on the confirmation and characterization of the components of the TOI-969 planetary system, where TESS detected a Neptune-size planet candidate in a very close-in orbit around a late K-dwarf star. Methods. We use a set of precise radial velocity observations from HARPS, PFS, and CORALIE instruments covering more than two years in combination with the TESS photometric light curve and other ground-based follow-up observations to confirm and characterize the components of this planetary system. Results. We find that TOI-969 b is a transiting close-in (Pb ∼ 1.82 days) mini-Neptune planet (Formula Presented), placing it on the lower boundary of the hot-Neptune desert (Teq,b = 941 \ub1 31 K). The analysis of its internal structure shows that TOI-969 b is a volatile-rich planet, suggesting it underwent an inward migration. The radial velocity model also favors the presence of a second massive body in the system, TOI-969 c, with a long period of (Formula Presented) days, a minimum mass of (Formula Presented), and a highly eccentric orbit of (Formula Presented). Conclusions. The TOI-969 planetary system is one of the few around K-dwarfs known to have this extended configuration going from a very close-in planet to a wide-separation gaseous giant. TOI-969 b has a transmission spectroscopy metric of 93 and orbits a moderately bright (G = 11.3 mag) star, making it an excellent target for atmospheric studies. The architecture of this planetary system can also provide valuable information about migration and formation of planetary systems

    TOI-1634 b: An Ultra-short-period Keystone Planet Sitting inside the M-dwarf Radius Valley

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    Studies of close-in planets orbiting M dwarfs have suggested that the M dwarf radius valley may be well-explained by distinct formation timescales between enveloped terrestrials, and rocky planets that form at late times in a gas-depleted environment. This scenario is at odds with the picture that close-in rocky planets form with a primordial gaseous envelope that is subsequently stripped away by some thermally-driven mass loss process. These two physical scenarios make unique predictions of the rocky/enveloped transition's dependence on orbital separation such that studying the compositions of planets within the M dwarf radius valley may be able to establish the dominant physics. Here, we present the discovery of one such keystone planet: the ultra-short period planet TOI-1634 b (P=0.989P=0.989 days, F=121FF=121 F_{\oplus}, rp=1.7900.081+0.080Rr_p = 1.790^{+0.080}_{-0.081} R_{\oplus}) orbiting a nearby M2 dwarf (Ks=8.7K_s=8.7, Rs=0.45RR_s=0.45 R_{\odot}, Ms=0.50MM_s=0.50 M_{\odot}) and whose size and orbital period sit within the M dwarf radius valley. We confirm the TESS-discovered planet candidate using extensive ground-based follow-up campaigns, including a set of 32 precise radial velocity measurements from HARPS-N. We measure a planetary mass of 4.910.70+0.68M4.91^{+0.68}_{-0.70} M_{\oplus}, which makes TOI-1634 b inconsistent with an Earth-like composition at 5.9σ5.9\sigma and thus requires either an extended gaseous envelope, a large volatile-rich layer, or a rocky portion that is not dominated by iron and silicates to explain its mass and radius. The discovery that the bulk composition of TOI-1634 b is inconsistent with that of the Earth favors the gas-depleted formation mechanism to explain the emergence of the radius valley around M dwarfs with Ms0.5MM_s\lesssim 0.5 M_{\odot}
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