Objective To determine if serum levels of endothelial adhesion molecules were associated with the development of multiple organ failure (MOF) and in-hospital mortality in adult patients with severe sepsis. Design This study was a secondary data analysis of a prospective cohort study. Setting Patients were admitted to two tertiary intensive care units in San Antonio, TX, between 2007 and 2012. Patients Patients with severe sepsis at the time of intensive care unit (ICU) admission were enrolled. Inclusion criteria were consistent with previously published criteria for severe sepsis or septic shock in adults. Exclusion criteria included immunosuppressive medications or conditions. Interventions None. Measurements Baseline serum levels of the following endothelial cell adhesion molecules were measured within the first 72 hours of ICU admission: Intracellular Adhesion Molecule 1 (ICAM-1), Vascular Cell Adhesion Molecule-1 (VCAM-1), and Vascular Endothelial Growth Factor (VEGF). The primary and secondary outcomes were development of MOF (≥2 organ dysfunction) and in-hospital mortality, respectively. Main results Forty-eight patients were enrolled in this study, of which 29 (60%) developed MOF. Patients that developed MOF had higher levels of VCAM-1 (p=0.01) and ICAM-1 (p=0.01), but not VEGF (p=0.70) compared with patients without MOF (single organ failure only). The area under the curve (AUC) to predict MOF according to VCAM-1, ICAM-1 and VEGF was 0.71, 0.73, and 0.54, respectively. Only increased VCAM-1 levels were associated with in-hospital mortality (p=0.03). These associations were maintained even after adjusting for APACHE and SOFA scores using logistic regression. Conclusions High levels of serum ICAM-1 was associated with the development of MOF. High levels of VCAM-1 was associated with both MOF and in-hospital mortality.

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We solve the continuous one-dimensional Schrödinger equation for the case of an inverted nonlinear delta-function potential located at the origin, obtaining the bound state in closed form as a function of the nonlinear exponent. The bound state probability profile decays exponentially away from the origin, with a profile width that increases monotonically with the nonlinear exponent, becoming an almost completely extended state when this approaches two. At an exponent value of two, the bound state suffers a discontinuous change to a delta-like profile. Further increase of the exponent increases again the width of the probability profile, although the bound state is proven to be stable only for exponents below two. The transmission of plane waves across the nonlinear delta potential increases monotonically with the nonlinearity exponent and is insensitive to the sign of its opacity.

We show that nonlinear tight-binding lattices of different geometries and dimensionalities, display an universal selftrapping behavior. First, we consider the single nonlinear impurity problem in various tight-binding lattices, and use the Green's function formalism for an exact calculation of the minimum nonlinearity strength to form a stationary bound state. For all lattices, we find that this critical nonlinearity parameter (scaled by the energy of the bound state), in terms of the nonlinearity exponent, falls inside a narrow band, which converges to e 1/2 at large exponent values. Then, we use the Discrete Nonlinear Schrödinger (DNLS) equation to examine the selftrapping dynamics of a single excitation, initially localized on the single nonlinear site, and compute the critical nonlinearity parameter for abrupt dynamical selftrapping. For a given nonlinearity exponent, this critical nonlinearity, properly scaled, is found to be nearly the same for all lattices. Same results are obtained when generalizing to completely nonlinear lattices, suggesting an underlying selftrapping universality behavior for all nonlinear (even disordered) tight-binding lattices described by DNLS.The Discrete Nonlinear Schrödinger (DNLS) equation is a paradigmatic equation describing among others, dynamics of polarons in deformable media [1], local modes in molecular systems [2] and power exchange among nonlinear coherent couplers in nonlinear optics [3]. Its most striking feature is the possibility of "selftrapping", that is, the clustering of vibrational energy or electronic probability or electromagnetic energy in a small region of space. In a condensed matter context, the DNLS equation has the formwhere C n is the probability amplitude of finding the electron (or excitation) on site n of a d-dimensional lattice, ǫ n is the on-site energy, V is the transfer matrix element, χ n is the nonlinearity parameter at site n and α is the nonlinearity exponent. The prime in the sum in (1) restricts the summation to nearest-neighbors only. In the conventional DNLS case, α = 2 and χ n is proportional to the square of the electron-phonon coupling at site n.[4] Considerable work has been carried out in recent years to understand the stationary and dynamical properties of Eq. (1) in various cases. In particular, we point out the studies on the stability of the stationary solutions in one and two dimensions for the homogeneous case (ǫ n = 0, χ n = χ) [5,6], the effect of point linear impurities on the stability of the 2-D DNLS solitons [7], the effects of nonlinear disorder (ǫ n = 0, χ n random) [8] and of linear disorder (χ n = χ, ǫ n random)[9] on the selftrapping dynamics of initially localized and extended excitations in a chain. The results obtained in these studies suggest that, in general, the effect of nonlinearity is quite local for initially localized excitations, and that disorder leaves the narrow selftrapped excitations unaffected, although it does affect the propagation of the untrapped portion ("radiation"). In this Letter we show ...

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