2,375 research outputs found
Following severe injury, hypocholesterolemia improves with convalescence but persists with organ failure or onset of infection
INTRODUCTION: Our primary objective was to determine the impact of traumatic injury, onset of infection, organ/metabolic dysfunction, and mortality on serum cholesterol. METHODS: During 676 surgical intensive care unit (SICU) days, 28 ventilated trauma patients underwent daily measurement of white blood cell (WBC) count and differential, cholesterol, arterial oxygen tension/fractional inspired oxygen, bilirubin, glucose, creatinine, and bicarbonate. With the onset of infection, WBC response was considered positive if the WBC count was 16.0 or greater, immature neutrophils were 10% or greater, or WBC count increased by 20%. Cholesterol response was considered positive if cholesterol decreased or failed to increase by 10%. RESULTS: Injury Severity Score was 30.6 ± 8.6 and there were 48 infections. Initial cholesterol was decreased (119 ± 44 mg/dl) compared with expected values from a database (201 ± 17 mg/dl; P < 0.0001). The 25 survivors had higher cholesterol at SICU discharge (143 ± 35 mg/dl) relative to admission (112 ± 37 mg/dl; P < 0.0001). In the three patients who died, the admission cholesterol was 175 ± 62 mg/dl and the cholesterol at death was 117 ± 27 mg/dl. The change in percentage of expected cholesterol (observed value divided by expected value) from admission to discharge was different for patients surviving (16 ± 19%) and dying (-29 ± 19%; P = 0.0005). With onset of infection, the WBC response was positive in 61% and cholesterol response was positive in 91% (P = 0.001). Percentage of expected cholesterol was decreased with each system dysfunction: arterial oxygen tension/fractional inspired oxygen < 350, creatinine > 2.0 mg/dl, glucose > 120 mg/dl, bilirubin > 2.5 mg/dl, and bicarbonate ≥ 28 or ≤ 23 (P < 0.01). Percentage of expected cholesterol decreased as the number of dysfunctions increased (P = 0.0001). CONCLUSION: Hypocholesterolemia is seen following severe injury. Convalescing patients (ready for SICU discharge) have improved cholesterol levels, whereas dying patients appear to have progressive hypocholesterolemia. Decreasing or fixed cholesterol levels suggest the development of infection or organ/metabolic dysfunction. Cholesterol responses are more sensitive for the onset of infection than are WBC responses. Sequential cholesterol monitoring is recommended for patients with severe trauma
Exact Spin and Pseudo-Spin Symmetric Solutions of the Dirac-Kratzer Problem with a tensor potential via Laplace Transform Approach
Exact bound state solutions of the Dirac equation for the Kratzer potential
in the presence of a tensor potential are studied by using the Laplace
transform approach for the cases of spin- and pseudo-spin symmetry. The energy
spectra is obtained in the closed form for the relativistic as well as
non-relativistic cases including the Coulomb potential. It is seen that our
analytical results are in agrement with the ones given in literature. The
numerical results are also given in a table for different parameter values.Comment: 8 page
ASCORE: an up-to-date cardiovascular risk score for hypertensive patients reflecting contemporary clinical practice developed using the (ASCOT-BPLA) trial data.
A number of risk scores already exist to predict cardiovascular (CV) events. However, scores developed with data collected some time ago might not accurately predict the CV risk of contemporary hypertensive patients that benefit from more modern treatments and management. Using data from the randomised clinical trial Anglo-Scandinavian Cardiac Outcomes Trial-BPLA, with 15 955 hypertensive patients without previous CV disease receiving contemporary preventive CV management, we developed a new risk score predicting the 5-year risk of a first CV event (CV death, myocardial infarction or stroke). Cox proportional hazard models were used to develop a risk equation from baseline predictors. The final risk model (ASCORE) included age, sex, smoking, diabetes, previous blood pressure (BP) treatment, systolic BP, total cholesterol, high-density lipoprotein-cholesterol, fasting glucose and creatinine baseline variables. A simplified model (ASCORE-S) excluding laboratory variables was also derived. Both models showed very good internal validity. User-friendly integer score tables are reported for both models. Applying the latest Framingham risk score to our data significantly overpredicted the observed 5-year risk of the composite CV outcome. We conclude that risk scores derived using older databases (such as Framingham) may overestimate the CV risk of patients receiving current BP treatments; therefore, 'updated' risk scores are needed for current patients
A Note on Scalar Field Theory in AdS_3/CFT_2
We consider a scalar field theory in AdS_{d+1}, and introduce a formalism on
surfaces at equal values of the radial coordinate. In particular, we define the
corresponding conjugate momentum. We compute the Noether currents for
isometries in the bulk, and perform the asymptotic limit on the corresponding
charges. We then introduce Poisson brackets at the border, and show that the
asymptotic values of the bulk scalar field and the conjugate momentum transform
as conformal fields of scaling dimensions \Delta_{-} and \Delta_{+},
respectively, where \Delta_{\pm} are the standard parameters giving the
asymptotic behavior of the scalar field in AdS. Then we consider the case d=2,
where we obtain two copies of the Virasoro algebra, with vanishing central
charge at the classical level. An AdS_3/CFT_2 prescription, giving the
commutators of the boundary CFT in terms of the Poisson brackets at the border,
arises in a natural way. We find that the boundary CFT is similar to a
generalized ghost system. We introduce two different ground states, and then
compute the normal ordering constants and quantum central charges, which depend
on the mass of the scalar field and the AdS radius. We discuss certain
implications of the results.Comment: 24 pages. v2: added minor clarification. v3: added several comments
and discussions, abstract sligthly changed. Version to be publishe
AdS/CFT, Multitrace Deformations and New Instabilities of Nonlocal String Theories
We study "multitrace" deformations of large N master fields in models with a
mass gap. In particular, we determine the conditions for the multitrace
couplings to drive tachyonic instabilities. These tachyons represent new local
instabilities of the associated nonlocal string theories. In the particular
case of Dp-branes at finite temperature, we consider topology-changing phase
transitions and the effect of multitrace perturbations on the corresponding
phase diagrams.Comment: harvmac. 28 pages. 9 eps figure
Remarks on Resonant Scalars in the AdS/CFT Correspondence
The special properties of scalars having a mass such that the two possible
dimensions of the dual scalar respect the unitarity and the
Breitenlohner-Freedman bounds and their ratio is integral (``resonant
scalars'') are studied in the AdS/CFT correspondence. The role of logarithmic
branches in the gravity theory is related to the existence of a trace anomaly
and to a marginal deformation in the Conformal Field Theory. The existence of
asymptotic charges for the conformal group in the gravity theory is interpreted
in terms of the properties of the corresponding CFT.Comment: 16 pages, 1 figur
Violation of Energy Bounds in Designer Gravity
We continue our study of the stability of designer gravity theories, where
one considers anti-de Sitter gravity coupled to certain tachyonic scalars with
boundary conditions defined by a smooth function W. It has recently been argued
there is a lower bound on the conserved energy in terms of the global minimum
of W, if the scalar potential arises from a superpotential P and the scalar
reaches an extremum of P at infinity. We show, however, there are
superpotentials for which these bounds do not hold.Comment: 16 pages, 4 figures, v2: discussion of vacuum decay included, typos
corrected, reference adde
Exponential Type Complex and non-Hermitian Potentials in PT-Symmetric Quantum Mechanics
Using the NU method [A.F.Nikiforov, V.B.Uvarov, Special Functions of
Mathematical Physics, Birkhauser,Basel,1988], we investigated the real
eigenvalues of the complex and/or - symmetric, non-Hermitian and the
exponential type systems, such as Poschl-Teller and Morse potentials.Comment: 14 pages, Late
Gluon Scattering Amplitudes in Finite Temperature Gauge/Gravity Dualities
We examine the gluon scattering amplitude in N=4 super Yang-Mills at finite
temperature with nonzero R-charge densities, and in Non-Commutative gauge
theory at finite temperature. The gluon scattering amplitude is defined as a
light-like Wilson loop which lives at the horizon of the T-dual black holes of
the backgrounds we consider. We study in detail a special amplitude, which
corresponds to forward scattering of a low energy gluon off a high energy one.
For this kinematic configuration in the considered backgrounds, we find the
corresponding minimal surface which is directly related to the gluon scattering
amplitude. We find that for increasing the chemical potential or the
non-commutative parameter, the on-shell action corresponding to our Wilson loop
in the T-dual space decreases. For all of our solutions the length of the short
side of the Wilson loop is constrained by an upper bound which depends on the
temperature, the R-charge density and the non-commutative parameter. Due to
this constraint, in the limit of zeroth temperature our approach breaks down
since the upper bound goes to zero, while by keeping the temperature finite and
letting the chemical potential or the non-commutative parameter to approach to
zero the limit is smooth.Comment: 30 pages, 16 figures, minor corrections (plus improved numerical
computation for the non-commutative case
Holographic Description of AdS Cosmologies
To gain insight in the quantum nature of the big bang, we study the dual
field theory description of asymptotically anti-de Sitter solutions of
supergravity that have cosmological singularities. The dual theories do not
appear to have a stable ground state. One regularization of the theory causes
the cosmological singularities in the bulk to turn into giant black holes with
scalar hair. We interpret these hairy black holes in the dual field theory and
use them to compute a finite temperature effective potential. In our study of
the field theory evolution, we find no evidence for a "bounce" from a big
crunch to a big bang. Instead, it appears that the big bang is a rare
fluctuation from a generic equilibrium quantum gravity state.Comment: 34 pages, 8 figures, v2: minor changes, references adde
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