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51.
Over a 4-year period 40,923 operations and 44,716 surgical admissions were monitored for both community and hospital onset infections. One thousand eight hundred sixty-five patients had 1966 surgical wound infections and 2056 remote infections including 1652 hospital onset and 404 community onset infections. One thousand one hudnred forty-four patients with multiple infections averaged 40 days in the hospital contrasted with 24 days for 721 patients with a single wound infection. The total excess cost of hospitalization for these patients was $951,150. A statistically significant reduction occurred for urinary tract infections, lower respiratory infections and clean and contaminated surgical wound infections. It is suggested that these are all inter-related and a significant reduction in surgical wound infections can be achieved through control of infections at remote sites, particularly those associated with medical devices. The coagulase positive staphylococcus is still the most important single bacterial species in the primary etiology of surgical wound infections. When the gastrointestinal tract is entered or "supra" infecting organisms appear, gram negative bacteria and mixed gram negative and gram positive infections are dominant. Reduction in remote site infections occurring in surgical patients is necessary to reduce the incidence of surgical wound infections, suggest preventive and control measures, and document the effectiveness of such measures. 相似文献
52.
Confining a binary mixture, one can profoundly alter its miscibility behavior. The qualitative features of miscibility in confined geometry are ratheruniversal and shared by polymer mixtures as well as small molecules, but the unmixing transition in the bulk and the wetting transition are typically well separated in polymer blends. The interplay between wetting and miscibility of a symmetric polymer mixture via large-scale Monte Carlo simulations in the framework of the bond fluctuation model and via numerical self–consistent field calculations is studied. The film surfaces interact with the monomers via short ranged potentials, and the wetting transition of the semi–infinite system is of first order. It can be accurately located in the simulations by measuring the surface and interface tensions and using Young’s equation. If both surfaces in a film attract the same component, capillary condensation occurs and the critical point is close to the critical point of the bulk. If surfaces attract different components, an interface localization/delocalization occurs which gives rise to phase diagrams with two critical points in the vicinity of the pre-wetting critical point of the semi–infinite system. The crossover between these two types of phase diagrams as a function of the surface field asymmetry is studied. The dependence of the phase diagram on the film thickness Δ for antisymmetric surface fields is investigated. Upon decreasing the film thickness, the two critical points approach the symmetry axis of the phase diagram, and below a certain thickness Δtri, there remains only a single critical point at the symmetric composition. This corresponds to a second-order interface localization/delocalization transition even though the wetting transition is of first order. At a specific film thickness, Δtri, tricritical behavior is found. The behavior of antisymmetric films is compared with the phase behavior in an antisymmetric double wedge. While the former is the analog of the wetting transition of a planar surface, the latter is related to the filling behavior of a single wedge. Evidence for a second-order interface localization/delocalization transition in an antisymmetric double wedge is presented, and its unconventional critical behavior is related to the predictions of Parry et al. (Phys. Rev. Lett. 83:5535 (1999)) for wedge filling. The critical behavior differs from the Ising universality class and is characterized by strong anisotropic fluctuations.Invited paper presented at the Fifteenth Symposium on Thermophysical Properties, June 022–27, 2003, Boulder, Colorado, U.S.A. 相似文献
53.
Gordon Peter C.; Hendrick Randall; Johnson Marcus; Lee Yoonhyoung 《Canadian Metallurgical Quarterly》2006,32(6):1304
The nature of working memory operation during complex sentence comprehension was studied by means of eye-tracking methodology. Readers had difficulty when the syntax of a sentence required them to hold 2 similar noun phrases (NPs) in working memory before syntactically and semantically integrating either of the NPs with a verb. In sentence structures that placed these NPs at the same linear distances from one another but allowed integration with a verb for 1 of the NPs, the comprehension difficulty was not seen. These results are interpreted as indicating that similarity-based interference occurs online during the comprehension of complex sentences and that the degree of memory accessibility conventionally associated with different types of NPs does not have a strong effect on sentence processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Hong-Gi Lee Arapostathis A. Marcus S.I. 《Automatic Control, IEEE Transactions on》2003,48(9):1646-1650
We extend the results from a previous paper of ours to multiple-input systems, and utilize these to obtain necessary and sufficient conditions for the linearization of discrete-time nonlinear systems via restricted dynamic feedback. We observe that for discrete-time nonlinear systems, the bound on the number of delays (or integrators) needed to synthesize the linearizing dynamic feedback differs from the continuous-time analogue. 相似文献
57.
The feasibility of interferometric SAR (INSAR) coherence observations for stem volume (biomass) retrieval is investigated by applying coherence data determined from 14 ERS-1 and ERS-2 C-band SAR image pairs. The image set covers a single forested test area in Finland, and both summer (snow-free) and winter conditions are represented. The data set enabled (a) the study of stem volume retrieval performance under varying conditions, (b) the analysis of the seasonal behavior of interferometric coherence, and (c) the determination of the accuracy characteristics of empirical (nonlinear) coherence modeling. Additionally, a new technique to estimate forest stem volume from INSAR data was developed based on constrained iterative inversion of the applied empirical model. The results indicate that the usability of winter images with snow-covered terrain is superior to that of images obtained under summer conditions. The applied empirical model appears to be adequate for describing the stand-wise coherence of boreal forest. Hence, a practical stem volume estimation method can be established based on it. The highest correlation coefficient between the estimated stem volume and the ground truth stem volume showed values as high as r=0.9 and a relative RMSE level of 48% was obtained, respectively. 相似文献
58.
Franke A.E. Heck John.M. Tsu-Jae King Howe R.T. 《Journal of microelectromechanical systems》2003,12(2):160-171
Two approaches were demonstrated for fabricating microstructures after completion of CMOS circuits with aluminum metallization. The first approach employed n-type poly-Ge deposited at 400/spl deg/C as a structural material with an SiO/sub 2/ sacrificial layer and an HF release. The CMOS circuits were protected from the release etchant with an amorphous Si layer. Clamped-clamped lateral resonator test structures had quality factors in vacuum as high as /spl sim/30000. Following a 500/spl deg/C, 30 s RTA the poly-Ge stress was 200 MPa (tensile) and the resistivity was 5.3 m/spl Omega/-cm. In the second integration approach, p-type poly-Si/sub 0.35/Ge/sub 0.65/ deposited at 450/spl deg/C was the structural material with poly-Ge as the sacrificial material and H/sub 2/O/sub 2/ as the release etchant. The H/sub 2/O/sub 2/ did not significantly etch the p-type poly-SiGe structural layer and no protection of the underlying CMOS layers was needed. For the first time, the fabrication of LPCVD surface microstructures directly on top of standard electronics was demonstrated, providing dramatic reductions in both MEMS-CMOS interconnect parasitics and device area. A folded flexure lateral resonator had a quality factor in vacuum as high as /spl sim/15000. No stress or dopant-activation anneal was needed, since the in situ boron-doped poly-SiGe was found to have an as-deposited stress of only -10 MPa (compressive) and a resistivity of only 1.8 m/spl Omega/-cm. 相似文献
59.
Controlling Spin Qubits in Quantum Dots 总被引:1,自引:0,他引:1
Hans-Andreas Engel L. P. Kouwenhoven Daniel Loss C. M. Marcus 《Quantum Information Processing》2004,3(1-5):115-132
We review progress on the spintronics proposal for quantum computing where the quantum bits (qubits) are implemented with electron spins. We calculate the exchange interaction of coupled quantum dots and present experiments, where the exchange coupling is measured via transport. Then, experiments on single spins on dots are described, where long spin relaxation times, on the order of a millisecond, are observed. We consider spin-orbit interaction as sources of spin decoherence and find theoretically that also long decoherence times are expected. Further, we describe the concept of spin filtering using quantum dots and show data of successful experiments. We also show an implementation of a read out scheme for spin qubits and define how qubits can be measured with high precision. Then, we propose new experiments, where the spin decoherence time and the Rabi oscillations of single electrons can be measured via charge transport through quantum dots. Finally, all these achievements have promising applications both in conventional and quantum information processing.
PACS: 03.67.Lx, 03.67.Mn, 73.23.Hk, 85.35.Be 相似文献
60.
Hardware-Accelerated Rendering of Photo Hulls 总被引:1,自引:0,他引:1