102 research outputs found
Concentration of rocuronium in cerebrospinal fluid of patients undergoing cerebral aneurysm clipping†
Background. This study assessed the concentration of rocuronium in the cerebrospinal fluid (CSF) of patients undergoing cerebral aneurysm clipping, and investigated whether the mode of administration (single bolus vs continuous infusion) influenced the CSF concentration. Methods. Twenty patients with subarachnoid haemorrhage were randomly allocated to receive a bolus dose (bolus group), or a bolus followed by a continuous infusion of rocuronium (infusion group) (n=10 for each group). Arterial blood and ventricular CSF were sampled 2 h after the rocuronium bolus. Samples were analysed by liquid chromatography electrospray ionization‐tandem mass spectrometry. Results. Rocuronium could be detected in all the CSF samples. The mean (range) CSF concentration was 2.2 (0.9-4.6) ng ml-1 in the bolus group and 12.4 (2.4-34.6) ng ml-1 in the infusion group; P<0.01. Conclusions. This study demonstrated that rocuronium, normally not considered to cross the blood-brain barrier, is regularly found in the CSF of patients undergoing cerebral clipping; continuous infusion of the drug led to higher plasma and CSF concentrations than after a single bolus dose. Br J Anaesth 2004; 92: 419-2
Gaia FGK Benchmark stars: Opening the black box of stellar element abundance determination
Gaia and its complementary spectroscopic surveys combined will yield the most comprehensive database of kinematic and chemical information of stars in the Milky Way. The Gaia FGK benchmark stars play a central role in this matter as they are calibration pillars for the atmospheric parameters and chemical abundances for various surveys. The spectroscopic analyses of the benchmark stars are done by combining different methods, and the results will be affected by the systematic uncertainties inherent in each method. In this paper, we explore some of these systematic uncertainties. We determined line abundances of Ca, Cr, Mn and Co for four benchmark stars using six different methods. We changed the default input parameters of the different codes in a systematic way and found, in some cases, significant differences between the results. Since there is no consensus on the correct values for many of these default parameters, we urge the community to raise discussions towards standard input parameters that could alleviate the difference in abundances obtained by different methods. In this work, we provide quantitative estimates of uncertainties in elemental abundances due to the effect of differing technical assumptions in spectrum modelling
Multi-dimension Tensor Factorization Collaborative Filtering Recommendation for Academic Profiles
The choice of academic itineraries and/or optional subjects to attend is not usually an easy decision since, in most cases, students lack the information, maturity, and knowledge required to make right decisions. This paper evaluates the support of Collaborative Systems for helping and guiding students in this decision-making process, considering the behavior and impact of these systems on the use of data different from the formal information the students usually use. For this purpose, the research applied the clustering based Multi-dimension Tensor Factorization approach to build a recommendation system and confirm that the increment in tensors improves the recommendation accuracy. As a result, this approach permits the user to take advantage of the contextual information to reduce the sparsity issue and increase the recommendation accuracy
The GALAH survey: a catalogue of carbon-enhanced stars and CEMP candidates
Swan bands - characteristic molecular absorption features of the C-2 molecule - are a spectroscopic signature of carbon-enhanced stars. They can also be used to identify carbonenhanced metal-poor (CEMP) stars. The GALAH (GALactic Archaeology with Hermes) is a magnitude-limited survey of stars producing high-resolution, high-signal-to-noise spectra. We used 627 708 GALAH spectra to search for carbon-enhanced stars with a supervised and unsupervised classification algorithm, relying on the imprint of the Swan bands. We identified 918 carbon-enhanced stars, including 12 already described in the literature. An unbiased selection function of the GALAH survey allows us to perform a population study of carbon-enhanced stars. Most of them are giants, out of which we find 28 CEMP candidates. A large fraction of our carbon-enhanced stars with repeated observations show variation in radial velocity, hinting that there is a large fraction of variables among them. 32 of the detected stars also show strong Lithium enhancement in their spectra.KC, TZ, and GT acknowledge financial support of the Slovenian Research Agency (research core funding No. P1-0188 and project N1-0040). JK is supported by a Discovery Project grant from the Australian Research Council (DP150104667) awarded to J. BlandHawthorn and T. Bedding. DMN was supported by the Allan C. and Dorothy H. Davis Fellowship. SLM acknowledges support from the Australian Research Council through grant DP180101791. Parts of this research were conducted by the Australian Research Council Centre of Excellence for All Sky Astrophysics in Three Dimensions (ASTRO 3D), through project number CE170100013. KF is grateful for support from Australian Research Council grant DP160103747. DS is the recipient of an ARC Future Fellowship (project number FT140100147)
The GALAH survey: Multiple stars and our Galaxy. I. A comprehensive method for deriving properties of FGK binary stars
Binary stellar systems form a large fraction of the Galaxy's stars. They are
useful as laboratories for studying the physical processes taking place within
stars, and must be correctly taken into account when observations of stars are
used to study the structure and evolution of the Galaxy. We present a sample of
12760 well-characterised double-lined spectroscopic binaries that are
appropriate for statistical studies of the binary populations. They were
detected as SB2s using a t-distributed stochastic neighbour embedding (t-SNE)
classification and a cross-correlation analysis of GALAH spectra. This sample
consists mostly of dwarfs, with a significant fraction of evolved stars and
several dozen members of the giant branch. To compute parameters of the primary
and secondary star (, , [Fe/H], ,
, , , and ), we used a
Bayesian approach that includes a parallax prior from Gaia DR2, spectra from
GALAH, and apparent magnitudes from APASS, Gaia DR2, 2MASS, and WISE. The
derived stellar properties and their distributions show trends that are
expected for a population of close binaries (a 10 AU) with mass ratios . The derived metallicity of these binary stars is statistically
lower than that of single dwarf stars from the same magnitude-limited sample.Comment: Accepted for publication in A&
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Inflation Physics from the Cosmic Microwave Background and Large Scale Structure
Fluctuations in the intensity and polarization of the cosmic microwave background (CMB) and the large-scale distribution of matter in the universe each contain clues about the nature of the earliest moments of time. The next generation of CMB and large-scale structure (LSS) experiments are poised to test the leading paradigm for these earliest moments---the theory of cosmic inflation---and to detect the imprints of the inflationary epoch, thereby dramatically increasing our understanding of fundamental physics and the early universe.
A future CMB experiment with sufficient angular resolution and frequency coverage that surveys at least 1% of the sky to a depth of 1 uK-arcmin can deliver a constraint on the tensor-to-scalar ratio that will either result in a 5-sigma measurement of the energy scale of inflation or rule out all large-field inflation models, even in the presence of foregrounds and the gravitational lensing B-mode signal. LSS experiments, particularly spectroscopic surveys such as the Dark Energy Spectroscopic Instrument, will complement the CMB effort by improving current constraints on running of the spectral index by up to a factor of four, improving constraints on curvature by a factor of ten, and providing non-Gaussianity constraints that are competitive with the current CMB bounds.Astronom
Systemic versus localized coagulation activation contributing to organ failure in critically ill patients
In the pathogenesis of sepsis, inflammation and coagulation play a pivotal role. Increasing evidence points to an extensive cross-talk between these two systems, whereby inflammation not only leads to activation of coagulation but coagulation also considerably affects inflammatory activity. The intricate relationship between inflammation and coagulation may not only be relevant for vascular atherothrombotic disease in general but has in certain clinical settings considerable consequences, for example in the pathogenesis of microvascular failure and subsequent multiple organ failure, as a result of severe infection and the associated systemic inflammatory response. Molecular pathways that contribute to inflammation-induced activation of coagulation have been precisely identified. Pro-inflammatory cytokines and other mediators are capable of activating the coagulation system and downregulating important physiological anticoagulant pathways. Activation of the coagulation system and ensuing thrombin generation is dependent on an interleukin-6-induced expression of tissue factor on activated mononuclear cells and endothelial cells and is insufficiently counteracted by physiological anticoagulant mechanisms and endogenous fibrinolysis. Interestingly, apart from the overall systemic responses, a differential local response in various vascular beds related to specific organs may occur
Patterns of paediatric end-of-life care: a chart review across different care settings in Switzerland.
Paediatric end-of-life care is challenging and requires a high level of professional expertise. It is important that healthcare teams have a thorough understanding of paediatric subspecialties and related knowledge of disease-specific aspects of paediatric end-of-life care. The aim of this study was to comprehensively describe, explore and compare current practices in paediatric end-of-life care in four distinct diagnostic groups across healthcare settings including all relevant levels of healthcare providers in Switzerland.
In this nationwide retrospective chart review study, data from paediatric patients who died in the years 2011 or 2012 due to a cardiac, neurological or oncological condition, or during the neonatal period were collected in 13 hospitals, two long-term institutions and 10 community-based healthcare service providers throughout Switzerland.
Ninety-three (62%) of the 149 reviewed patients died in intensive care units, 78 (84%) of them following withdrawal of life-sustaining treatment. Reliance on invasive medical interventions was prevalent, and the use of medication was high, with a median count of 12 different drugs during the last week of life. Patients experienced an average number of 6.42 symptoms. The prevalence of various types of symptoms differed significantly among the four diagnostic groups. Overall, our study patients stayed in the hospital for a median of six days during their last four weeks of life. Seventy-two patients (48%) stayed at home for at least one day and only half of those received community-based healthcare.
The study provides a wide-ranging overview of current end-of-life care practices in a real-life setting of different healthcare providers. The inclusion of patients with all major diagnoses leading to disease- and prematurity-related childhood deaths, as well as comparisons across the diagnostic groups, provides additional insight and understanding for healthcare professionals. The provision of specialised palliative and end-of-life care services in Switzerland, including the capacity of community healthcare services, need to be expanded to meet the specific needs of seriously ill children and their families
Is sugammadex economically viable for routine use
Purpose of review Sugammadex belongs to a new class of drugs termed selective relaxant binding agents and is now available for clinical use in over 50 countries. Because of its innovative mechanism of action, reversal of rocuronium or vecuronium becomes independent of the degree of residual neuromuscular blockade. Deep or intense neuromuscular blockade now can rapidly and predictably be reversed. However, compared with the classical acetylcholine esterase inhibitor-based reversal treatment costs are significantly higher. On the basis of the current literature, the cost-effectiveness of sugammadex will be evaluated. Recent findings There is a paucity of evidence-based studies that investigate the pharmacoeconomic aspects of sugammadex reversal. However, several studies assessed the cost-effectiveness of routine reversal with sugammadex compared with cholinesterase inhibitors and one study from the UK analyzed the economic aspects of a rocuronium/sugammadex concept compared with succinylcholine in a 'cannot intubate-cannot ventilate' scenario. The concept of cost reduction by dose reduction of sugammadex is also addressed. Summary The reduction of recovery times with sugammadex will reduce the incidence of prolonged extubation and may increase patients' throughput. However, the achievable reduction of costs depends on the individual organizational factors, also
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