Hydrogen Peroxide Wound Irrigation in Orthopaedic Surgery.

As the burden of deep hardware infections continues to rise in orthopaedics, there is increasing interest in strategies for more effective debridement of colonized tissues and biofilm. Hydrogen peroxide has been used medically for almost a century, but its applications in orthopaedic surgery have yet to be fully determined. The basic science and clinical research on the antiseptic efficacy of hydrogen peroxide have demonstrated its efficacy against bacteria, and it has demonstrated potential synergy with other irrigation solutions such as chlorhexidine and povidone-iodine. While hydrogen peroxide is effective in infection reduction, there are concerns with wound healing, cytotoxicity, and embolic phenomena, and we recommend against hydrogen peroxide usage in the treatment of partial knee replacements, hemiarthroplasties, or native joints. Additionally, due to the potential for oxygen gas formation, hydrogen peroxide should not be used in cases of dural compromise, when pressurizing medullary canals, or when irrigating smaller closed spaces to avoid the possibility of air embolism. Finally, we present our protocol for irrigation and debridement and exchange of modular components in total joint arthroplasty, incorporating hydrogen peroxide in combination with povidone-iodine and chlorhexidine

Doctor of Philosophy

dissertationThe electrical conductivity properties of nickel nanostrands in polymer composite systems are investigated and characterized. Recently developed nickel nanostrands feature a three-dimensionally interconnecting and branching nanostructure that is shown to be highly effective at imparting electrical conductivity in polymer composites. A systematic investigation of material behaviors is undertaken, with results that have been or will be published in a series of journal articles. The content of the studies that form these articles is given herein as the core content of this work. The first study investigates the basic electrical and mechanical properties of nanostrands in a single polymer system. Key results indicate a strong dependence of conductivity properties on processing conditions, volume fraction of conductor, and sample geometry. Mechanical properties are not significantly altered by the presence of nanostrands. The dispersed nanostrand structure is next investigated through the development of statistical topology tools that can quantify nanostrand dispersions and correlate them to the electrical resistivity of composite films. Quantification of the dispersed nanostructure is a significant improvement over common literature approaches. The next step tests full percolation characterization across multiple polymer systems, and indicates a strong dependence on electrical resistivity between polymer types. Polymer constituent properties are found to be poor predictors of nanostrand composites conductivities, though further testing of addition metrics is expected to bring improved correlation. The concluding investigation seeks electrical conductivity percolation models for nanostrand composites. Existing models show only moderate accuracy, and a newly developed combined percolation tunneling approached is suggested for improved fit to measured conductivity

AG Codes from Polyhedral Divisors

A description of complete normal varieties with lower dimensional torus action has been given by Altmann, Hausen, and Suess, generalizing the theory of toric varieties. Considering the case where the acting torus T has codimension one, we describe T-invariant Weil and Cartier divisors and provide formulae for calculating global sections, intersection numbers, and Euler characteristics. As an application, we use divisors on these so-called T-varieties to define new evaluation codes called T-codes. We find estimates on their minimum distance using intersection theory. This generalizes the theory of toric codes and combines it with AG codes on curves. As the simplest application of our general techniques we look at codes on ruled surfaces coming from decomposable vector bundles. Already this construction gives codes that are better than the related product code. Further examples show that we can improve these codes by constructing more sophisticated T-varieties. These results suggest to look further for good codes on T-varieties.Comment: 30 pages, 9 figures; v2: replaced fansy cycles with fansy divisor

A stochastic model to study genetic and metabolic effects on N-linked protein glycosylation

Glycosylation is a vital processing step for a large number of cellular proteins as it critically affects protein stability and solubility as well as protein-protein interactions. As a consequence, glycosylation is a major quality attribute of recombinant proteins in biopharmaceutical applications. However, since glycosylation does not follow a template, but instead involves a complex interplay of various influencing factors in the Golgi, tailoring glycosylation towards certain desired attributes is challenging and usually requires trial-and-error experimentation. Computational modeling offers an intriguing option to understand and rationally engineer the complex reaction network underlying glycosylation. Here we present a computational model that describes N-linked protein glycosylation as a stochastic process. The model successfully recapitulates the biological complexity of glycosylation, but does not require the input of kinetic data. We show how the model can be used to predict the effect of glycosyltransferase knock-outs or overexpression on glycosylation in CHO. In addition, we demonstrate how the model can be linked to flux-balance models of CHO metabolism and use it to predict how cell culture conditions, such as extracellular nutrients, affect glycosylation. Thus, our modeling approach offers a promising tool for engineering glycosylation in both academic and industrial contexts

Constructs: Truth, Lies, and Humanity

This thesis is a discussion of my ideas, struggles and outcomes experienced during the making of my two bodies of work, Devices and Relics. These two bodies of work explore fleeting moments, the intrinsic values of labor and imagination with reference to sedentary living and labor in contemporary American society

The changing motivations of students' use of lecture podcasts across a semester: an extended theory of planned behaviour approach

We extended the previous work of Moss, O’Connor and White, to include a measure of group norms within the theory of planned behaviour (TPB), to examine the influences on students’ decisions to use lecture podcasts as part of their learning. Participants (N = 90) completed the extended TPB predictors before semester began (Time 1) and mid-semester (Time 2) and reported on their podcast use at mid-semester (Time 2) and end of semester (Time 3). We found that attitudes and perceived social pressures were important in informing intentions at both time points. At Time 1, perceptions of control over performing the behaviour and, at Time 2, perceptions of whether podcast use was normative among fellow students (group norms) also predicted intended podcast use. Intentions to use podcasting predicted self-reported use at both Time 2 and Time 3. These results provide important applied information for educators to encourage student use of novel on-line educational tools

Temperature responses of substrate carbon conversion efficiencies and growth rates of plant tissues

Growth rates of plant tissues depend on both the respiration rate and the efficiency with which carbon is incorporated into new structural biomass. Calorespirometric measurement of respiratory heat and CO2 rates, from which both efficiency and growth rate can be calculated, is a well established method for determining the effects of rapid temperature changes on the respiratory and growth properties of plant tissues. The effect of the alternative oxidase/cytochrome oxidase activity ratio on efficiency is calculated from first principles. Data on the temperature dependence of the substrate carbon conversion efficiency are tabulated. These data show that ε is maximum and approximately constant through the optimum growth temperature range and decreases rapidly as temperatures approach temperature limits to growth. The width of the maximum and the slopes of decreasing ε at high and low temperatures vary greatly with species, cultivars and accessions

Axillary surgery in women with sentinel node-positive operable breast cancer: a systematic review with meta-analyses

Traditionally, women with node-positive operable breast cancer have received complete axillary lymph node dissection (ALND), which is associated with significant morbidity, but recently less invasive alternatives have been explored. We conducted a systematic review of randomised controlled trials assessing alternative approaches to axillary surgery in patients with pathologically-confirmed sentinel node-positive operable breast cancer. We searched on 16/3/15 the Specialized Register of the Cochrane Breast Cancer group; CENTRAL; MEDLINE; PreMEDLINE; EMBASE; WHO International Clinical Trials Registry Portal; ClinicalTrials.gov; conference proceedings from ASCO and the San Antonio Breast Cancer meetings; checked reference lists and contacted authors to identify relevant studies. Double, independent study sifting, extraction, appraisal and summarising were undertaken using standard Cochrane Collaboration methodology. We included three studies (2020 patients) comparing ALND with sentinel lymph node dissection (SLND) to SLND alone, and two studies (1899 patients) comparing ALND to axillary radiotherapy (aRT). No differences in survival or recurrence were observed between ALND and SLND or aRT, but morbidity may have been increased in ALND, and all the results were subject to different biases, such as recruitment bias, performance bias, and outcome-reporting bias. Whilst it is encouraging that there appears to be no adverse effect on recurrence or survival, it will be appropriate to confirm these findings and provide additional data confirming quality of life effects and long term outcomes

External Behavior of a Logic Program and Verification of Refactoring

Refactoring is modifying a program without changing its external behavior. In this paper, we make the concept of external behavior precise for a simple answer set programming language. Then we describe a proof assistant for the task of verifying that refactoring a program in that language is performed correctly