Estimating the effect of healthcare-associated infections on excess length of hospital stay using inverse probability-weighted survival curves

Background: Studies estimating excess length of stay (LOS) attributable to nosocomial infections have failed to address time-varying confounding, likely leading to overestimation of their impact. We present a methodology based on inverse probability–weighted survival curves to address this limitation. Methods: A case study focusing on intensive care unit–acquired bacteremia using data from 2 general intensive care units (ICUs) from 2 London teaching hospitals were used to illustrate the methodology. The area under the curve of a conventional Kaplan-Meier curve applied to the observed data was compared with that of an inverse probability–weighted Kaplan-Meier curve applied after treating bacteremia as censoring events. Weights were based on the daily probability of acquiring bacteremia. The difference between the observed average LOS and the average LOS that would be observed if all bacteremia cases could be prevented was multiplied by the number of admitted patients to obtain the total excess LOS. Results: The estimated total number of extra ICU days caused by 666 bacteremia cases was estimated at 2453 (95% confidence interval [CI], 1803–3103) days. The excess number of days was overestimated when ignoring time-varying confounding (2845 [95% CI, 2276–3415]) or when completely ignoring confounding (2838 [95% CI, 2101–3575]). Conclusions: ICU-acquired bacteremia was associated with a substantial excess LOS. Wider adoption of inverse probability–weighted survival curves or alternative techniques that address time-varying confounding could lead to better informed decision making around nosocomial infections and other time-dependent exposures

Solution growth of Triglycine Sulfate (TGS) crystals on the International Microgravity Laboratory (IML-1)

An experiment was planned for the International Microgravity Laboratory (IML-1) to be launched around Feb. 1991. Crystals of triglycine sulfate (TGS) will be grown by low temperature solution crystal growth technique using a multiuser facility called Fluid Experiment System (FES). A special cooled sting technique of solution crystal growth will be used where heat is extracted from the seed crystal through a semi-insulating sting, thereby creating the desired supersaturation near the growing crystal. Also, a holocamera will be used to provide tomography of the three dimensional flow field and particle image displacement velocimetry to monitor the convective flows

Growth and characterization of crystals for IR detectors and second harmonic gereration devices

Two types of materials, L-arginine phosphate (LAP) and doped triglycine sulfate (TGS), are examined for their growth characteristics and relevant properties for second harmonic generation and IR detector applications, respectively

Impact of a passive social marketing intervention in community pharmacies on oral contraceptive and condom sales: a quasi-experimental study

Abstract Background Almost 50% of pregnancies in the United States are unwanted or mistimed. Notably, just over one-half of unintended pregnancies occurred when birth control was being used, suggesting inappropriate or poor use or contraceptive failure. About two-thirds of all women who are of reproductive age use contraceptives, and oral hormonal contraceptives remain the most common contraceptive method. Often, contraceptive products are obtained in community pharmacies. The purpose of this study was to determine whether a pharmacy-based intervention would impact sales of contraceptive products in pharmacies. Methods This study was conducted in Iowa and used a quasi-experimental design including 55 community pharmacies (independent and grocery) in 12 counties as the intervention and 32 grocery pharmacies in 10 counties as a comparison group. The passive intervention was focused towards 18–30 year old women who visited community pharmacies and prompted those of childbearing age to “plan your pregnancy” and “consider using birth control”. The intervention was delivered via educational tri-fold brochures, posters and ‘shelf talkers.’ Data sources for evaluation were contraceptive sales from intervention and comparison pharmacies, and a mixed negative binomial regression was used with study group*time interactions to examine the impact of the intervention on oral contraceptive and condom sales. Data from 2009 were considered baseline sales. Results From 2009 to 2011, condom sales decreased over time and oral contraceptives sales showed no change. Overall, the units sold were significantly higher in grocery pharmacies than in independent pharmacies for both contraceptive types. In the negative binomial regression for condoms, there was an overall significant interaction between the study group and time variables (p = 0.003), indicating an effect of the intervention, and there was a significant slowing in the drop of sales at time 3 in comparison with time 1 (p < 0.001). There was a statistically significant association between pharmacy type and study group, where the independent intervention pharmacies had a higher proportion of stores with increases in condom sales compared to grocery pharmacies in the intervention or comparison group. Conclusions A passive community pharmacy-based public health intervention appeared to reduce the decrease in condom sales from baseline, particularly in independent pharmacies, but it did not impact oral contraceptive sales.http://deepblue.lib.umich.edu/bitstream/2027.42/110681/1/12889_2015_Article_1495.pd

Effects of phase transitions in devices actuated by the electromagnetic vacuum force

We study the influence of the electromagnetic vacuum force on the behaviour of a model device based on materials, like germanium tellurides, that undergo fast and reversible metal-insulator transitions on passing from the crystalline to the amorphous phase. The calculations are performed at finite temperature and fully accounting for the behaviour of the material dielectric functions. The results show that the transition can be exploited to extend the distance and energy ranges under which the device can be operated without undergoing stiction phenomena. We discuss the approximation involved in adopting the Casimir expression in simulating nano- and micro- devices at finite temperature

Solution Growth and Characterization of Single Crystals on Earth and in Microgravity

Crystal growth has been of interest to physicists and engineers for a long time because of their unique properties. Single crystals are utilized in such diverse applications as pharmaceuticals, computers, infrared detectors, frequency measurements, piezoelectric devices, a variety of high-technology devices, and sensors. Solution crystal growth is one of the important techniques to grow a variety of crystals when the material decomposes at the melting point and a suitable solvent is available to make a saturated solution at a desired temperature. In this Technical Memorandum (TM) an attempt is made to give the fundamentals of growing crystals from solution including improved designs of various crystallizers. Since the same solution crystal growth technique could not be used in microgravity, the authors proposed a new cooled-sting technique to grow crystals in space. The authors experience from conducting two Space Shuttle solution crystal growth experiments are also detailed in this TM and the complexity of solution growth experiments to grow crystals in space are also discussed. These happen to be some of the early experiments performed in space, and various lessons learned are described. A brief discussion of protein crystal growth that shares basic principles of the solution growth technique is given, along with some flight hardware information for growth in microgravity

Para to Ortho transition of metallic dimers on Si(001)

Extensive electronic structure calculations are performed to obtain the stable geometries of metals like Al, Ga and In on the Si(001) surface at 0.5 ML and 1 ML coverages. Our results coupled with previous theoretical findings explain the recent experimental data in a comprehensive fashion. At low coverages, as shown by previous works, `Para' dimers give the lowest energy structure. With increasing coverage beyond 0.5 ML, `Ortho' dimers become part of low energy configurations leading toward a `Para' to `Ortho' transition at 1 ML coverage. For In mixed staggered dimers (`Ortho' and `Para') give the lowest energy configuration. For Ga, mixed dimers are non-staggered, while for Al `Para' to `Ortho' transition of dimers is complete. Thus at intermediate coverages between 0.5 and 1 ML, the `Ortho' and `Para' dimers may coexist on the surface. Consequently, this may be an explanation of the fact that the experimental observations can be successfully interpreted using either orientation. A supported zigzag structure at 0.5 ML, which resembles ${\rm (CH)_x}$, does not undergo a dimerization transition, and hence stays semi-metallic. Also, unlike ${\rm (CH)_x}$ the soliton formation is ruled out for this structure.Comment: 8 pages, 6 figure

Growth and Characteristics of Bulk Single Crystals Grown from Solution on Earth and in Microgravity

The growth of crystals has been of interest to physicists and engineers for a long time because of their unique properties. Single crystals are utilized in such diverse applications as pharmaceuticals, computers, infrared detectors, frequency measurements, piezoelectric devices, a variety of high technology devices and sensors. Solution crystal growth is one of the important techniques to grow a variety of crystals when the material decomposes at the melting point and a suitable solvent is available to make a saturated solution at a desired temperature. In this chapter an attempt is made to give some fundamentals of growing crystals from solution including improved designs of various crystallizers. Since the same solution crystal growth technique could not be used in microgravity, authors had proposed a new cooled sting technique to grow crystals in space. Authors? experiences of conducting two space shuttle experiments relating to solution crystal growth are also detailed in this work. The complexity of these solution growth experiments to grow crystals in space are discussed. These happen to be some of the early experiments performed in space, and various lessons learned are described. A brief discussion of protein crystal growth that also shares basic principles of solution growth technique is given along with some flight hardware information for its growth in microgravity

Case Studies in Web-Controlled Devices and Remote Manipulation

The concept of distance learning has been more and more articulated during the past few years and is expected to shortly turn into a practical education system within current high level learning institutions. The chances are that distance learning would transparently extend colleges and institutes of education, and could plausibly overtake and turn into a preferred choice of higher education, especially for adult and working students. The concept would be unachievable without the current technology, for example, the impressive worldwide accessibility of the Internet. The main idea in e-learning is to build adequate solutions that could assure educational training over the Internet, without requiring a personal presence at the degree offering institution. For example, being able to obtain a Bachelor’s degree in Computer Engineering from an accredited institution while residing thousands of miles away from it and actually never seeing it, except maybe for the graduation ceremony. The advantages are immediate and of unique importance, to enumerate a few: Scholarship / education costs can be reduced dramatically, both from a student’s perspective and the institution’s (no need for room and board, for example); The usually tedious immigration and naturalization issues that are common with international students are eliminated; The limited campus facilities, faculty members and course schedules an institution can offer are no longer a boundary; Working adults can consider upgrading skills without changing their lifestyle