Prognosis of Transient New-Onset Atrial Fibrillation During Vascular Surgery

AbstractBackgroundChronic atrial fibrillation (AF) in a non-surgical setting is associated with cardiovascular events. However, the prognosis of transient new-onset AF during vascular surgery is unknown.ObjectiveThe purpose of this study is to investigate the prognosis of new-onset AF during vascular surgery using continuous electrocardiographic monitoring (continuous-ECG).MethodsIn this study, 317 patients, all in sinus rhythm, scheduled for major vascular surgery were screened for cardiac risk factors. Continuous-ECG recordings for 72h and standard ECG on days 3, 7 and 30 were used to identify new-onset AF. Cardiac troponin T (cTnT) was measured routinely after surgery. Study endpoint was a composite of cardiac death, myocardial infarction, unstable angina and stroke (cardiovascular events) at 30 days after surgery and during late follow-up. Median follow-up was 12 (interquartile range 2–28) months.ResultsNew-onset AF was noted in 15 (4.7%) patients. All but three patients returned spontaneously to sinus rhythm. The composite endpoint of cardiovascular events within 30 days and during late follow-up occurred in 34 (11%) and 62 (20%) patients, respectively. Multivariate regression analysis showed that new-onset AF was associated with perioperative (hazard ratio (HR) 6.0; 95% CI: 2.4–15) and late cardiovascular events (HR 4.2, 95% CI: 2.1–8.8).ConclusionNew-onset AF during vascular surgery is associated with an increased incidence of 30-day and late cardiovascular events

The Effectiveness of Poly-(4-vinyl-N-hexylpyridiniumbromide) as an Antibacterial Implant Coating: An In Vitro Study

The clinical success of osseointegrated dental implants depends on the strong attachment of the surrounding hard and soft tissues. Bacterial adhesion on implant surfaces can cause inflammatory reactions and may influence healing and long-term success of dental implants. Promising implant coatings should minimize bacterial adhesion, but allow epithelial and connective tissue attachment. Therefore, the present study has examined the bioactive effect of poly-(4-vinyl-N-hexylpyridiniumbromide) regarding typical oral bacteria as well as cytotoxicitiy to human cells considering different methods of connecting polymers to silicate-containing surfaces. The results revealed that the application of putative antibacterial and biocompatible polymer in coating strategies is affected by a variety of parameters. Published findings regarding reduced bacterial adhesion could not be verified using oral pathogens whereas hexylated polymers seem problematic for strong adhesion of soft tissue. Concerning innovative coatings for dental implants basic aspects (surface roughness, thickness, alkylation, combination with other polymers) have to be considered in further investigations

Network Power Fault Detection

Network power fault detection. At least one first network device is instructed to temporarily disconnect from a power supply path of a network, and at least one characteristic of the power supply path of the network is measured at a second network device connected to the network while the at least one first network device is temporarily disconnected from the network

Correlated patterns in non-monotonic graded-response perceptrons

The optimal capacity of graded-response perceptrons storing biased and spatially correlated patterns with non-monotonic input-output relations is studied. It is shown that only the structure of the output patterns is important for the overall performance of the perceptrons.Comment: 4 pages, 4 figure

Global properties of Stochastic Loewner evolution driven by Levy processes

Standard Schramm-Loewner evolution (SLE) is driven by a continuous Brownian motion which then produces a trace, a continuous fractal curve connecting the singular points of the motion. If jumps are added to the driving function, the trace branches. In a recent publication [1] we introduced a generalized SLE driven by a superposition of a Brownian motion and a fractal set of jumps (technically a stable L\'evy process). We then discussed the small-scale properties of the resulting L\'evy-SLE growth process. Here we discuss the same model, but focus on the global scaling behavior which ensues as time goes to infinity. This limiting behavior is independent of the Brownian forcing and depends upon only a single parameter, $\alpha$, which defines the shape of the stable L\'evy distribution. We learn about this behavior by studying a Fokker-Planck equation which gives the probability distribution for endpoints of the trace as a function of time. As in the short-time case previously studied, we observe that the properties of this growth process change qualitatively and singularly at $\alpha =1$. We show both analytically and numerically that the growth continues indefinitely in the vertical direction for $\alpha > 1$, goes as $\log t$ for $\alpha = 1$, and saturates for $\alpha< 1$. The probability density has two different scales corresponding to directions along and perpendicular to the boundary. In the former case, the characteristic scale is $X(t) \sim t^{1/\alpha}$. In the latter case the scale is $Y(t) \sim A + B t^{1-1/\alpha}$ for $\alpha \neq 1$, and $Y(t) \sim \ln t$ for $\alpha = 1$. Scaling functions for the probability density are given for various limiting cases.Comment: Published versio

Developing markets? Understanding the role of markets and development at the intersection of macromarketing and transformative consumer research (TCR)

Situated at the intersection of markets and development, this commentary aims to promote a cross-fertilization of macromarketing and Transformative Consumer Research (TCR) that directs attention to the sociocultural context and situational embeddedness of consumer experience and well-being, while acknowledging complex, systemic interdependencies between markets, marketing, and society. Based on a critical review of the meaning of development and an interrogation of various developmental discourses, the authors develop a conceptual framework that brings together issues of development, well-being, and social inequalities. We suggest that these issues are better understood and addressed when examined via grounded investigations of the role of markets in shaping the management of resources, consumer agency, power inequalities and ethics. The use of markets as units of analysis may lead to further cross-fertilizations of TCR and macromarketing and to more comprehensive theorizing and transformational impact. Two empirical cases are provided to illustrate our framework

Concrete structural analysis tools and properties for Hanford site waste tank evaluation

As Hanford Site Contractors address maintenance and future structural demands on nuclear waste tanks built as early as 1943, it is necessary to address their current safety margins and ensure safe margins are maintained. Although the current civil engineering practice has building codes for reinforced concrete design guidelines, the tanks were not constructed to today`s building codes and future demands potentially result in loads and modifications to the tanks that are outside the original design basis and current practice. The Hanford Site engineering staff has embraced nonlinear finite-element modeling of concrete in an effort to obtain a more accurate understanding of the actual tank margins. This document brings together and integrates past Hanford Site nonlinear reinforced concrete analysis methods, past Hanford Site concrete testing, public domain research testing, and current concrete research directions. This document, including future revisions, provides the structural engineering overview (or survey) for a consistent, accurate approach to nonlinear finite-element modeling of reinforced concrete for Hanford Site waste storage tanks. This report addresses concrete strength and modulus degradation with temperature, creep, shrinkage, long-term sustained loads, and temperature degradation of rebar and concrete bonds. Recommendations are given for parameter studies and evaluation techniques for review of nonlinear finite-element analysis of concrete

Prognosis of Vascular Surgery Patients Using a Quantitative Assessment of Troponin T Release: Is the Crystal Ball still Clear?

AbstractBackgroundCardiac troponin T (cTnT) assays with increased sensitivity might increase the number of positive tests. Using the area under the curve (AUC) with serial sampling of cTnT an exact quantification of the myocardial damage size can be made. We compared the prognosis of vascular surgery patients with integrated cTnT–AUC values to continuous and standard 12-lead electrocardiography (ECG) changes.Methods513 Patients were monitored. cTnT sampling was performed on postoperative days 1, 3, 7, 30 and/or at discharge or whenever clinically indicated. If cTnT release occurred, daily measurements of cTnT were performed, until baseline was achieved. CTnT–AUC was quantified and divided in tertiles. All-cause mortality and cardiovascular events (cardiac death and myocardial infarction) were noted during follow-up.Results81/513 (16%) Patients had cTnT release. After adjustment for gender, cardiac risk factors, and site and type of surgery, those in the highest cTnT–AUC tertile were associated with a significantly worse cardiovascular outcome and long-term mortality (HR 20.2; 95% CI 10.2–40.0 and HR 4.0; 95% CI 2.0–7.8 respectively). Receiver operator analysis showed that the best cut-off value for cTnT–AUC was <0.01 days*ng m for predicting long-term cardiovascular events and all-cause mortality.ConclusionIn vascular surgery patients quantitative assessment of cTnT strongly predicts long-term outcome

Convection in colloidal suspensions with particle-concentration-dependent viscosity

The onset of thermal convection in a horizontal layer of a colloidal suspension is investigated in terms of a continuum model for binary-fluid mixtures where the viscosity depends on the local concentration of colloidal particles. With an increasing difference between the viscosity at the warmer and the colder boundary the threshold of convection is reduced in the range of positive values of the separation ratio psi with the onset of stationary convection as well as in the range of negative values of psi with an oscillatory Hopf bifurcation. Additionally the convection rolls are shifted downwards with respect to the center of the horizontal layer for stationary convection (psi>0) and upwards for the Hopf bifurcation (psi<0).Comment: 8 pages, 6 figures, submitted to European Physical Journal