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To report the International Nosocomial Infection Control Consortium surveillance data from 40 hospitals (20 cities) in India 2004–2013.
Surveillance using US National Healthcare Safety Network’s criteria and definitions, and International Nosocomial Infection Control Consortium methodology.
We collected data from 236,700 ICU patients for 970,713 bed-days
Pooled device-associated healthcare-associated infection rates for adult and pediatric ICUs were 5.1 central line–associated bloodstream infections (CLABSIs)/1,000 central line–days, 9.4 cases of ventilator-associated pneumonia (VAPs)/1,000 mechanical ventilator–days, and 2.1 catheter-associated urinary tract infections/1,000 urinary catheter–days
In neonatal ICUs (NICUs) pooled rates were 36.2 CLABSIs/1,000 central line–days and 1.9 VAPs/1,000 mechanical ventilator–days
Extra length of stay in adult and pediatric ICUs was 9.5 for CLABSI, 9.1 for VAP, and 10.0 for catheter-associated urinary tract infections. Extra length of stay in NICUs was 14.7 for CLABSI and 38.7 for VAP
Crude extra mortality was 16.3% for CLABSI, 22.7% for VAP, and 6.6% for catheter-associated urinary tract infections in adult and pediatric ICUs, and 1.2% for CLABSI and 8.3% for VAP in NICUs
Pooled device use ratios were 0.21 for mechanical ventilator, 0.39 for central line, and 0.53 for urinary catheter in adult and pediatric ICUs; and 0.07 for mechanical ventilator and 0.06 for central line in NICUs.
Despite a lower device use ratio in our ICUs, our device-associated healthcare-associated infection rates are higher than National Healthcare Safety Network, but lower than International Nosocomial Infection Control Consortium Report.
Infect. Control Hosp. Epidemiol. 2016;37(2):172–181
We report on the effect of the International Nosocomial Infection Control Consortium's (INICC) multidimensional approach for the reduction of ventilator-associated pneumonia (VAP) in adult patients hospitalized in 21 intensive-care units (ICUs), from 14 hospitals in 10 Indian cities. A quasi-experimental study was conducted, which was divided into baseline and intervention periods. During baseline, prospective surveillance of VAP was performed applying the Centers for Disease Control and Prevention/National Healthcare Safety Network definitions and INICC methods. During intervention, our approach in each ICU included a bundle of interventions, education, outcome and process surveillance, and feedback of VAP rates and performance. Crude stratified rates were calculated, and by using random-effects Poisson regression to allow for clustering by ICU, the incidence rate ratio for each time period compared with the 3-month baseline was determined. The VAP rate was 17·43/1000 mechanical ventilator days during baseline, and 10·81 for intervention, showing a 38% VAP rate reduction (relative risk 0·62, 95% confidence interval 0·5–0·78, P = 0·0001).
Two strains of E-Coli K-12, viz, RP437, MG1655 and B/r (E. coli B derivative, not a K-12 strain) were grown on various surfaces to study bacterial adhesion and subsequent biofilm formation. We observed biofilm and large colonies on cover slides, beads made of soda lime or borosilicate glasses, on plasma treated PDMS (Polydimethylsiloxane), on Tissue Culture (TC) polystyrene, and observed some clusters on plasma treated ZnTi cover slide; but no evidence of biofilm on untreated-PDMS and ZnTi glass cover slides. From contact angle measurements, we conclude that the hydrophobic nature of untreated PDMS prevent bacterial adhesion for these three strains.
The ability to organize materials in two or three dimensional structures forms the basis for approach worldwide to construct nanometer sized arrangements. Here we show the interaction of 200 MeV silver ions with a Si( 100) single crystal lattice which has been studied to look for defects with atomic resolution. Employing scanning tunnelling microscopy (STM), we demonstrate that the deposited energy is not stored as random defected arrangements at the irradiation site but as spatially extended structures at predetermined locations. These artificially reordered structures consist of random Si atoms, placed atomically sharp next to the single crystalline lattice.
The microgeometry of the pore space influences the membrane potential Em. and theDC electrical conductivity σ of a shaly sand in a similar manner, independent of the details of the geometry: Em and σ being related via the conductivities of cations and σanions;σ=σcation + σ onion, and Em α σ cation/(σcation + σanion). This explicit relationship is used to investigate the role of the geometrical factors which influence both Em and σ in a related manner. The dependence of σ on the water conductivity σw can be well approximated with four geometrical parameters which can be obtained from the slopes and the interceptsof σ vs. σw curve at high and low salinities. We show that these geometrical factors appear in the expression for Em a well. These geometrical parameters (one of them is the formation factor) vary from rock to rock, and any trend in these parameters depend on the local geology.
The interactions of Ti with SiO2, Si3N4, and SiOiNy have been studied during rapid thermal annealing at 400 to 900 °C in Ar with 3% H2 ambient. X-ray diffraction, sheet resistance measurements, RBS, nuclear reaction technique to profile hydrogen, and microscopy have been employed in this study. The results of this investigation indicate that Si3N4 and SiOxNy are more stable with Ti than SiO2.
Surface oxidation kinetics of an a-Si3 N4 submicron size and an amorphous nano-size powder have been studied using x-ray photoelectron spectroscopy (XPS) and Bremsstrahlung-excited Auger electron spectroscopy (AES). The samples were oxidized by heating in air at temperatures between 850°C and 1000°C. The oxide thickness for each heating time and temperature was determined both from the relative 0 Is and N Is XPS peak intensities and from the Si02 and Si3 N4 Si KLL peak intensities. In each case, there was a good agreement between the oxide thickness value calculated from the XPS data and that obtained from the AES data. At these temperatures, oxidation followed a linear rate law. Activation energies of 15±1 kcal/mole and 27±1 kcal/mole were measured for the a-powder and the amorphous powder, respectively.
The ultrasonic pulse transmission method (100-500 kHz) was adapted to measure compressional (P) and shear (S) wave velocities for synthetic soils fabricated from quartz-clay and quartz-peat mixtures. Velocities were determined as samples were loaded by small (up to 0.1 MPa) uniaxial stress to determine how stress at grain contacts affects wave amplitudes, velocities, and frequency content. Samples were fabricated from quartz sand mixed with either a swelling clay or peat (natural cellulose). P velocities in these dry synthetic soil samples were low, ranging from about 230 to 430 m/s for pure sand, about 91 to 420 m/s for sand-peat mixtures, and about 230 to 470 m/s for dry sand-clay mixtures. S velocities were about half of the P velocity in most cases, about 130 to 250 m/s for pure sand, about 75-220 m/s for sand-peat mixtures, and about 88-220 m/s for dry sand-clay mixtures. These experiments demonstrate that P and S velocities are sensitive to the amount and type of admixed second phase at low concentrations. We found that dramatic increases in all velocities occur with small uniaxial loads, indicating strong nonlinearity of the acoustic properties. Composition and grain packing contribute to the mechanical response at grain contacts and the nonlinear response at low stresses.
Size segregation of particulates is of concern in a number of industries that handle materials such as chemicals, pharmaceuticals, fertilizers, and food products. Of particular interest in this paper is segregation resulting from externally applied vibration. In industrial applications this vibration may either be applied intentionally in devices such as vibrating conveyors or “live wall” hoppers, or unintentionally during material handling and transport. This paper investigates size segregation in granular beds subject to discrete “taps” and continuous, sinusoidal vertical vibration. The results from discrete element computer simulations indicate that the rise rate of a single impurity increases monotonically with amplitude for discrete vibrations but for continuous vibrations the rise rate increases, reaches a maximum value, then decreases as the oscillation amplitude increases.
We have shown that silver ion implantation or argon ion assisted surface deposition of silver inhibits cell growth on Glassy Polymeric Carbon (GPC), a desirable improvement of current cardiac implants. In vitro biocompatibility tests have been carried out with model cell lines to demonstrate that near surface implantation of silver in GPC can completely inhibit cell attachment on implanted areas while leaving adjacent areas vulnerable to strong cell adhesion. After cleaning and sterilization and more than one year in physiologic solution, the silver implanted GPC persists in inhibiting cell attachment.
The stability and electronic structure of fully H or F terminated and mixed H and F terminated diamond (111) surfaces were studied using first principles calculations. It was found that F atoms on the surface, like H, formed sp3 type bonding with C atoms, which resulted in a more stable 1×1 configuration rather than the π-bonded 2×1 construction of clean diamond. A phase diagram showing the stable surface composition regions was constructed as a function of chemical potentials of H and F. The diagram shows that the surface with 75% F (25% H) termination was unstable. The F terminated surface was more stable than H termination due to the formation of strong ionic C-F bonding and the close packing of the large F atoms. Due to the attractive forces developed between F atoms, a close packed surface was formed. Additionally, the exposure of C to the environment became restricted because of the large size of F atoms. Hence, F terminated diamond surface was more chemically inert compared to H terminated surface. To bring two F terminated surfaces together, a large repulsive force was required due to the negative charge on F atoms, and this led to low adhesion between two F terminated diamond surfaces compared to two H terminated surfaces.
There are many differences between the spaces ℝn and ℚn but the one we shall single out is that differentiable functions can be defined on ℝn but not on ℚn. It is this fact that invests the process of completion – i.e., passage from ℚn to ℝn – with so much interest.
A completion process requires more structure than topology. We have already discussed the Dedekind completion of the rationals, which is based on the concept of order and cannot be extended to sets that are not totally ordered. The most important class of spaces that can be completed are the metric spaces; a metric, as we have already noted, imposes more structure than a topology. Finally, there are the structures called uniformities, weaker than metrics but stronger than topologies, that can also be completed. Remarkably, the completion of uniform spaces, unlike that of metric spaces, does not require the explicit use of real numbers.
We shall discuss metric completion, uniformities and uniform completion in this appendix. A metric space can be completed in at least two different ways (with the same result); one can be generalized to uniform spaces, and the other cannot. We shall discuss only the former. Similarly, uniformities can be defined in at least three different but equivalent ways; we shall choose the one which is best adapted to generalizing the procedure of metric completion. The summaries given below will not provide balanced pictures of their subjects.
In quantum mechanics one requires the spaces of square-integrable wave functions to be complete; this cannot be achieved with Riemann-integrable functions. One also needs to determine the structure of self-adjoint operators (observables), the paradigm for which is the diagonalization of n × n Hermitian matrices. This is, however, a vastly more complex enterprise, and requires a deep understanding of the nature of these operators. Among the tools required for this endeavour, part of which is sketched in Appendix A6, are measures and integrals. This appendix will provide an introduction to these subjects tailored to the specific needs of this book.
Historically, the integral now known by his name was announced by Lebesgue in 1902, four years before metric spaces were defined by Fréchet, and more than a decade before the completion process for metric spaces was devised by Hausdorff. Lebesgue's theory was based on the notion of measure, which is a generalization of geometrical concepts such as length, area and volume, and of physical concepts such as mass and charge distributions, both discrete and continuous. In the 1920s (possibly earlier), it was noticed that an integral defined a metric on the space of integrable functions, and that the metric space of absolutely Riemann-integrable functions was incomplete. Its completion turned out to be the space of Lebesgue-integrable functions with the metric defined by the Lebesgue integral. This made it possible to develop the ‘theory of functions’ using only the notion of sets of measure zero. However, this simplification is no longer available when one tries to understand, say, the spectrum of a Hamiltonian operator.
Von Neumann's theory of measurement in Quantum Mechanics was spelled out in the last chapter of his book, which was published in 1932. This book was highly mathematical for its time, and in 1939 London and Bauer provided a simplified account of the measurement theory part of it (London and Bauer, 1939). Von Neumann died in 1957. Thirty years after the publication of von Neumann's book, Wigner published a review containing his views on the shortcomings of von Neumann's theory, but omitting any discussion of its mathematical core, namely von Neumann's analysis of composite systems (Wigner, 1963). He also published a set of lecture notes entitled Interpretation of Quantum Mechanics (Wigner, 1983) in which some of his concerns were spelled out in greater detail, and an article addressed ‘to an audience of non-physicists’ (Wigner, 1964). Wigner's own contributions to measurement theory were discussed by Shimony in a talk at the Wigner centennial conference (Shimony, 2002). The English translation of von Neumann's book was published in 1955.1 The account that follows is based on these sources.
We shall assume that the reader is acquainted with notions such as wave function collapse and the Heisenberg cut, but we shall not assume familiarity with the technicalities of von Neumann's theory. This chapter is organized accordingly. Section 8.1 explains what we mean by the term von Neumann's measurement theory and gives an overview of the subject. It is followed by Sections 8.2 and 8.3, in which the theory is spelled out in detail. Section 8.4 recounts Wigner's reservations.