3,845 research outputs found
Myocardial dysfunction after out-of-hospital cardiac arrest: predictors and prognostic implications.
We aim to determine the incidence of early myocardial dysfunction after out-of-hospital cardiac arrest, risk factors associated with its development, and association with outcome. A retrospective chart review was performed among consecutive out-of-hospital cardiac arrest (OHCA) patients who underwent echocardiography within 24 h of return of spontaneous circulation at three urban teaching hospitals. Our primary outcome is early myocardial dysfunction, defined as a left ventricular ejection fraction \u3c 40% on initial echocardiogram. We also determine risk factors associated with myocardial dysfunction using multivariate analysis, and examine its association with survival and neurologic outcome. A total of 190 patients achieved ROSC and underwent echocardiography within 24 h. Of these, 83 (44%) patients had myocardial dysfunction. A total of 37 (45%) patients with myocardial dysfunction survived to discharge, 39% with intact neurologic status. History of congestive heart failure (OR 6.21; 95% CI 2.54-15.19), male gender (OR 2.27; 95% CI 1.08-4.78), witnessed arrest (OR 4.20; 95% CI 1.78-9.93), more than three doses of epinephrine (OR 6.10; 95% CI 1.12-33.14), more than four defibrillations (OR 4.7; 95% CI 1.35-16.43), longer duration of resuscitation (OR 1.06; 95% CI 1.01-1.10), and therapeutic hypothermia (OR 3.93; 95% CI 1.32-11.75) were associated with myocardial dysfunction. Cardiopulmonary resuscitation immediately initiated by healthcare personnel was associated with lower odds of myocardial dysfunction (OR 0.40; 95% CI 0.17-0.97). There was no association between early myocardial dysfunction and mortality or neurological outcome. Nearly half of OHCA patients have myocardial dysfunction. A number of clinical factors are associated with myocardial dysfunction, and may aid providers in anticipating which patients need early diagnostic evaluation and specific treatments. Early myocardial dysfunction is not associated with neurologically intact survival
Quantification of the Individual Characteristics of the Human Dentition
The considerations for admissibility suggested by the Daubert trilogy challenge forensic experts to provide scientific support for opinion testimony. The defense bar has questioned the reliability of bitemark analysis. Under an award from the U. S. Department of Justice, via the Midwest Forensic Resource Center, a two-year feasibility study was undertaken to quantify six dental characteristics. Using two computer programs, the exemplars of 419 volunteers were digitally scanned, characteristics were measured, and frequency was calculated. The study demonstrates that there were outliers or rare dental characteristics in measurements. An analysis of the intra-observer and inter-observer consistency demonstrated a high degree of agreement. Expansion of the sample size through collaboration with other academic researchers will be necessary to be able to quantify the occurrence of these characteristics in the general population. The automated software application, Tom\u27s Toolbox, developed specifically for this research project, could also provide a template for precisely quantifying other pattern evidence
Do soil depth and plant community composition interact to modify the resistance and resilience of grassland ecosystem functioning to drought?
While the effect of drought on plant communities and their associated ecosystem functions is well studied, little research has considered how responses are modified by soil depth and depth heterogeneity. We conducted a mesocosm study comprising shallow and deep soils, and variable and uniform soil depths, and two levels of plant community composition, and exposed them to a simulated drought to test for interactive effects of these treatments on the resilience of carbon dioxide fluxes, plant functional traits, and soil chemical properties. We tested the hypotheses that: 1) shallow and variable depth soils lead to increased resistance and resilience of ecosystem functions to drought due to more exploitative plant trait strategies; 2) plant communities associated with intensively managed high fertility soils, will have more exploitative root traits than extensively managed, lower fertility plant communities. These traits will be associated with higher resistance and resilience to drought and may interact with soil depth and depth heterogeneity to amplify the effects on ecosystem functions.Our results showed that while there were strong soil depth/heterogeneity effects on plant driven carbon fluxes, it did not affect resistance or resilience to drought, and there were no treatment effects on plant available carbon or nitrogen. We did observe a significant increase in exploitative root traits in shallow and variable soils relative to deep and uniform, which may have resulted in a compensation effect which led to the similar drought responses.Plant community compositions representative of intensive management were more drought resilient than more diverse “extensive” communities irrespective of soil depth or soil depth heterogeneity. In intensively managed plant communities, root traits were more representative of exploitative strategies. Taken together our results suggest that reorganisation of root traits in response to soil depth could buffer drought effects on ecosystem functions.<br/
Exploring Anatomic Variants to Enhance Anatomy Teaching: Musculus Sternalis
The opportunity to encounter and appreciate the range of human variation in anatomic structures—and its potential impact on related structures, function, and treatment—is one of the chief benefits of cadaveric dissection for students in clinical preprofessional programs. The dissection lab is also where students can examine unusual anatomic variants that may not be included in their textbooks, lab manuals, or other course materials. For students specializing in physical medicine, awareness and understanding of muscle variants has a practical relevance to their preparations for clinical practice. In a routine dissection of the superficial chest muscles, graduate students in a human gross anatomy class exposed a large, well-developed sternalis muscle. The exposure of this muscle generated many student questions about M sternalis: its prevalence and appearance, its function, its development, and its evolutionary roots. Students used an inquiry protocol to guide their searches through relevant literature to gather this information. Instructors developed a decision tree to assist students in their inquiries, both by helping them to make analytic inferences and by highlighting areas of interest needing further investigation. Answering these questions enriches the understanding and promotes “habits of mind” for exploring musculoskeletal anatomy beyond simple descriptions of function and structure
Characterizing the Cool KOIs. VI. H- and K-band Spectra of Kepler M Dwarf Planet-Candidate Hosts
We present H- and K-band spectra for late-type Kepler Objects of Interest
(the "Cool KOIs"): low-mass stars with transiting-planet candidates discovered
by NASA's Kepler Mission that are listed on the NASA Exoplanet Archive. We
acquired spectra of 103 Cool KOIs and used the indices and calibrations of
Rojas-Ayala et al. to determine their spectral types, stellar effective
temperatures and metallicities, significantly augmenting previously published
values. We interpolate our measured effective temperatures and metallicities
onto evolutionary isochrones to determine stellar masses, radii, luminosities
and distances, assuming the stars have settled onto the main-sequence. As a
choice of isochrones, we use a new suite of Dartmouth predictions that reliably
include mid-to-late M dwarf stars. We identify five M4V stars: KOI-961
(confirmed as Kepler 42), KOI-2704, KOI-2842, KOI-4290, and the secondary
component to visual binary KOI-1725, which we call KOI-1725 B. We also identify
a peculiar star, KOI-3497, which has a Na and Ca lines consistent with a dwarf
star but CO lines consistent with a giant. Visible-wavelength adaptive optics
imaging reveals two objects within a 1 arc second diameter; however, the
objects' colors are peculiar. The spectra and properties presented in this
paper serve as a resource for prioritizing follow-up observations and planet
validation efforts for the Cool KOIs, and are all available for download online
using the "data behind the figure" feature.Comment: Accepted for publication in the Astrophysical Journal Supplement
Series (ApJS). Data and table are available in the sourc
Practice characteristics of Emergency Department extracorporeal cardiopulmonary resuscitation (eCPR) programs in the United States: The current state of the art of Emergency Department extracorporeal membrane oxygenation (ED ECMO).
PURPOSE: To characterize the current scope and practices of centers performing extracorporeal cardiopulmonary resuscitation (eCPR) on the undifferentiated patient with cardiac arrest in the emergency department.
METHODS: We contacted all US centers in January 2016 that had submitted adult eCPR cases to the Extracorporeal Life Support Organization (ELSO) registry and surveyed them, querying for programs that had performed eCPR in the Emergency Department (ED ECMO). Our objective was to characterize the following domains of ED ECMO practice: program characteristics, patient selection, devices and techniques, and personnel.
RESULTS: Among 99 centers queried, 70 responded. Among these, 36 centers performed ED ECMO. Nearly 93% of programs are based at academic/teaching hospitals. 65% of programs are less than 5 years old, and 60% of programs perform ≤3 cases per year. Most programs (90%) had inpatient eCPR or salvage ECMO programs prior to starting ED ECMO programs. The majority of programs do not have formal inclusion and exclusion criteria. Most programs preferentially obtain vascular access via the percutaneous route (70%) and many (40%) use mechanical CPR during cannulation. The most commonly used console is the Maquet Rotaflow(®). Cannulation is most often performed by cardiothoracic (CT) surgery, and nearly all programs (\u3e85%) involve CT surgeons, perfusionists, and pharmacists.
CONCLUSIONS: Over a third of centers that submitted adult eCPR cases to ELSO have performed ED ECMO. These programs are largely based at academic hospitals, new, and have low volumes. They do not have many formal inclusion or exclusion criteria, and devices and techniques are variable
A new spin-anisotropic harmonic honeycomb iridate
The physics of Mott insulators underlies diverse phenomena ranging from high
temperature superconductivity to exotic magnetism. Although both the electron
spin and the structure of the local orbitals play a key role in this physics,
in most systems these are connected only indirectly --- via the Pauli exclusion
principle and the Coulomb interaction. Iridium-based oxides (iridates) open a
further dimension to this problem by introducing strong spin-orbit
interactions, such that the Mott physics has a strong orbital character. In the
layered honeycomb iridates this is thought to generate highly spin-anisotropic
interactions, coupling the spin orientation to a given spatial direction of
exchange and leading to strongly frustrated magnetism. The potential for new
physics emerging from such interactions has driven much scientific excitement,
most recently in the search for a new quantum spin liquid, first discussed by
Kitaev \cite{kitaev_anyons_2006}. Here we report a new iridate structure that
has the same local connectivity as the layered honeycomb, but in a
three-dimensional framework. The temperature dependence of the magnetic
susceptibility exhibits a striking reordering of the magnetic anisotropy,
giving evidence for highly spin-anisotropic exchange interactions. Furthermore,
the basic structural units of this material suggest the possibility of a new
family of structures, the `harmonic honeycomb' iridates. This compound thus
provides a unique and exciting glimpse into the physics of a new class of
strongly spin-orbit coupled Mott insulators.Comment: 12 pages including bibliography, 5 figure
Orbital debris: A technical assessment
To acquire an unbiased technical assessment of (1) the research needed to better understand the debris environment, (2) the necessity and means of protecting spacecraft against the debris environment, and (3) potential methods of reducing the future debris hazard, NASA asked the National Research Council to form an international committee to examine the orbital debris issue. The committee was asked to draw upon available data and analyses to: characterize the current debris environment, project how this environment might change in the absence of new measures to alleviate debris proliferation, examine ongoing alleviation activities, explore measures to address the problem, and develop recommendations on technical methods to address the problems of debris proliferation
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Deprivation and prognosis in patients with Pulmonary Arterial Hypertension: missing the effect of deprivation on a rare disease?
In this journal, Pellino et al presented survival analysis to assess how deprivation affects prognosis in patients with pulmonary arterial hypertension (PAH)1. Their conclusions were that social deprivation is not a significant referral barrier or prognostic factor for idiopathic (I)PAH or heritable (H)PAH in Scotland. This may appear surprising given the wider context of literature describing outcomes stratified by social deprivation. The authors were thorough on using both the address at time of diagnosis and at time of censoring to assign deprivation scores and compare the two, finding no significant differences between the two approaches. They also compared deprivation assigned to PAH cases to expected deprivation based on Scottish citizenry as a whole and found that PAH patients are more socially deprived than expected. Finally, they used the same survival univariate analysis adjusting for age and sex to assess how several clinical variables are associated with prognosis
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