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In implant-based breast surgery, infections remain a clinically challenging complication. Surgeons often prophylactically address this risk by irrigating the implant at the time of placement. However, there remain few data on the ideal irrigant for gram-negative species.The authors assessed the relative efficacy of 10% povidone-iodine, triple-antibiotic solution, Prontosan, Clorpactin, and normal saline (negative control) against 3 gram-negative bacterial backgrounds: Escherichia coli , Pseudomonas aeruginosa , and Proteus species. A laboratory-adapted strain and a clinical isolate were selected for each group of bacteria. Sterile, smooth implant discs were immersed in each irrigant solution and then incubated in suspensions of each bacterial strain overnight at 37°C. Each disc was then rinsed and sonicated to displace biofilm-forming bacteria from the implant surface. The displaced bacteria were enumerated by plating, and normalized values were calculated for the bacterial counts of each irrigant.Povidone-iodine resulted in the greatest reduction of bacterial load for all 6 strains by a factor of 10 1 to 10 6 . Prontosan had a lesser, yet significant reduction in all bacterial strains. Triple-antibiotic solution demonstrated the greatest reduction in one Proteus species strain, and Clorpactin reduced bacterial counts in only half of the bacterial strains. When comparing laboratory strains to clinical isolates, significant differences were seen in each bacterial species in at least 2 irrigant solutions.Povidone-iodine has been proven the most effective at reducing bacterial contamination of E. coli, P. aeruginosa , and Proteus species in both laboratory-adapted strains and clinical isolates.This study proves that povidone-iodine is the most effective at preventing gram-negative infections in breast implant surgery.

Several techniques for determining the size of small fluid microdrops with diameters ranging from 5 to 30 μm have been developed and evaluated using an automated variation on the Millikan oil drop experiment. The average diameter of a large sample of monodisperse fluid drops was determined by measuring their terminal velocity in air, or if charged, their motion under the influence of an electric field, as well as by measurement of the magnitude of their Brownian motion. The diameter of individual drops was determined optically, by direct observation using an imaging system based on a charge-coupled-device camera. The technique used to analyze the image data is based on a best-fit technique taking the point spread function of the lens into account, and yields results accurate to 1% (based on a single image) without the need for any calibration. By combining this technique with terminal velocity measurements, the density of the fluid can be determined to similar accuracy.

For use in our Millikan type liquid drop searches for fractional charge elementary particles we have developed a simple ionized air device for neutralizing a narrow stream of small drops. The neutralizer has been used for drops ranging in diameter from 10 to 25 μm. The width of the produced charge distribution is given by the Boltzmann equilibrium charge distribution and the mean of the distribution is set by a bias voltage. Using the bias voltage, the mean can be set with a precision of better than e, the electron charge. The use of the neutralizer is illustrated in an application to mineral oil drops produced with charges of the order of 1000e. We also show the interesting case of silicone oil drops that are produced in our drop generator with a charge distribution narrower than the Boltzmann equilibrium charge distribution, the charge distribution being broadened by the neutralizer.

Although simulation-based education is now commonly utilized in medicine, its use in the instruction of congenital heart disease remains limited. The objective of this study is to evaluate whether heart models created with three-dimensional printing technology can be effectively incorporated into a simulation-based congenital heart disease and critical care training curriculum for pediatric resident physicians.Utilizing heart models created with a three-dimensional printer, pediatric residents participated in a 60-minute simulation seminar with three consecutive components: (1) didactic instruction on ventricular septal defect anatomy; (2) didactic/simulation-based instruction on echocardiographic imaging of ventricular septal defects and anatomical teaching/operative simulation of ventricular septal defect repair; (3) simulation-based instruction on postoperative critical care management of ventricular septal defects.Academic, free-standing, children's hospital with quaternary care referrals.Twenty-three pediatric resident physicians.Subjective, Likert-type questionnaires assessing knowledge acquisition, knowledge reporting, and structural conceptualization of ventricular septal defects.Three-dimensional printing technology was successfully utilized to create heart models of five common ventricular septal defect subtypes. After using these models in a simulation-based curriculum, pediatric residents were found to have improvement in the areas of knowledge acquisition (P = .0082), knowledge reporting (P = .01), and structural conceptualization (P.0001) of ventricular septal defects, as well as improvement in the ability to describe and manage postoperative complications in ventricular septal defect patients in the critical care setting.The utilization of three-dimensional printing in a simulation-based congenital heart disease and critical care training curriculum is feasible and improves pediatric resident physicians' understanding of a common congenital heart abnormality.

In this paper we review the experimental and observational searches for stable, massive, elementary particles other than the electron and proton. The particles may be neutral, may have unit charge or may have fractional charge. They may interact through the strong, electromagnetic, weak or gravitational forces or through some unknown force. The purpose of this review is to provide a guide for future searches - what is known, what is not known, and what appear to be the most fruitful areas for new searches. A variety of experimental and observational methods such as accelerator experiments, cosmic ray studies, searches for exotic particles in bulk matter and searches using astrophysical observations is included in this review., Comment: 34 pages, 8 eps figures

We present a new experimental method for searching for free fractional charge in bulk matter; this new method derives from the traditional Millikan liquid drop method, but allows the use of much larger drops, 20 to 100 mm in diameter, compared to the traditional method that uses drops less than 15 mm in diameter. These larger drops provide the substantial advantage that it is then much easier to consistently generate drops containing liquid suspensions of powdered meteorites and other special minerals. These materials are of great importance in bulk searches for fractional charge particles that may have been produced in the early universe., Comment: 17 pages, 5 figures in a singl PDF file (created from WORD Doc.). Submitted to Review of Scientific Instruments

We have used an automated Millikan oil drop method to search for free fractional-charge particles in a sample containing in total 3.9 mg of pulverized Allende meteorite suspended in 259 mg of mineral oil. The average diameter of the drops was 26.5 microm with the charge on about 42 500 000 drops being measured. This search was motivated by the speculation that isolatable, fractional-charge particles produced in the early Universe and present in our Solar System are more likely to be accumulated in asteroids than on Earth's surface. No evidence for fractional-charge particles was found. With 95% confidence, the concentration of particles with fractional-charge more than 0.25 e (e being the magnitude of the electron charge) from the nearest integer charge is less than 1.3 x 10(-21) particles per nucleon in the meteoritic material and less than 1.9 x 10(-23) particles per nucleon in the mineral oil.

We have carried out the largest search for stable particles with fractional electric charge, based on an oil drop method that incorporates a horizontal electric field and upward air flow. No evidence for such particles was found, giving a 95% C.L. upper limit of $1.17\times 10^{-22}$ particles per nucleon on the abundance of fractional charge particles in silicone oil for $0.18 e \le |Q_{residual}| \le 0.82 e$. Since this is the first use of this new method we describe the advantages and limitations of the method., 11 pages, 9 figures, 3 tables

The authors describe their ongoing work on, and future plans for, searches in bulk matter for fractional charge elementary particles and very massive elementary particles. Their primary interest is in searching for such particles that may have been produced in the early universe and may be found in the more primeval matter available in the solar system: meteorites, material from the moon's surface, and certain types of ancient terrestrial rocks. In the future the authors are interested in examining material brought back by sample return probes from asteroids. The authors will describe their experimental methods that are based on new modifications of the Millikan liquid drop technique and modern technology: micromachining, CCD cameras, and desktop computers. Extensions of the experimental methods and technology allow searches for very massive charged particles in primeval matter; particles with masses greater than 1,013 GeV. In the first such searches carried out on earth there will be uncertainties in the mass search range. Therefore the authors will also discuss the advantages of eventually carrying out such searches directly on an asteroid.

It will soon be the twenty fifth anniversary of the discovery of the tau lepton. It has been an amazing twenty five years for tau physics and for the strong interaction physics that can be deduced from studies of tau decays. The discovery of the tau was based on the elucidation of the nature of about one hundred tau pairs. At this Fifth International Workshop on Tau Lepton Physics new results in tau physics are based on hundreds of thousands or even millions of tau pairs. In the next two decades we will see the data on tau pairs increase by at least a factor of ten. The theoretical work and theoretical understanding of tau physics and tau neutrino physics has also expanded enormously, and this theory will continue to grow in its reach and its depth. Given the vastness of this field and the recognition that there is always great uncertainty in predicting future directions and accomplishments in a scientific field; any perspective of the future of a scientific field is substantially dependent on the author's opinions and guesses. I have limited this talk to seven topics: tau research facilities in the next decades, searching for unexpected tau decaymore » modes, searching for additional tau decay mechanisms, radiative tau decays, tau decay modes of the W, B, and D, searching for CP violation in tau decay, and rethinking the Tau-Charm factory.« less

Recent results on hadronic weak decays of the charmed mesons, D0→K0π0, K0η, K0η’ and D+s→ηπ+, η’π+, from the Mark III at SPEAR are presented.