Joshua Davis

Defect modes in coaxial photonic crystals

One-dimensional (1D) photonic crystals have been constructed by connecting segments of coaxial cable of differing characteristic impedance. Impurities have been introduced into these crystals by inserting cable segments to break the crystal symmetry. This system provides a simple way to study 1D photonic band structure effects with complete control over impurities in the lattice. We have studied the effects of the size, number, and location of defects in the lattice. We have also measured directly the concentration of energy in the steady-state electromagnetic fields within doped crystals, and observed the influence of the defects on the phase (dispersion). A modified dielectric stack model was developed to describe this system, with the results in excellent agreement with our measurements. Our findings compare favorably to previously published measurements of transmission and phase change in three-dimensional photonic crystals.

Bedside Shift-to-shift Handoffs: A Systematic Review of the Literature

Multiple institutions identify communication and shift-to-shift handoffs as a source of clinical errors. Conducting handoffs at the bedside has been proposed as a potential solution to improve the quality of communication at change of shift. This article reports a systematic review of English-language research articles, published between January 1, 2008, and October 31, 2014, focused on bedside shift-to-shift handoffs. Forty-one articles were identified and analyzed in this systematic review.

Taxane-induced hedgehog signaling is linked to expansion of breast cancer stem-like populations after chemotherapy.

Recurrence of breast cancer after chemotherapy is thought to arise from resistant breast cancer stem cells which are eventually able to repopulate the tumor. The Hedgehog (HH) signaling pathway has been shown to regulate the proliferation and survival of breast cancer stem cells, and has been shown to promote resistance to chemotherapy through the activation of multi‐drug resistance and pro survival pathways. Here we report that exposure of heterogenous breast cancer cell lines to docetaxel (DOC) resulted in release of Sonic Hedgehog ligand (SHH) and activation of the HH pathway as evidenced by increased expression and nuclear translocation of the downstream effector Gli‐1 at 4–24 h after DOC treatment. This activation had little effect on the bulk of the tumor cell population as inhibition of HH signaling failed to increase apoptosis in response to DOC. However, HH pathway activation was required for clonogenic growth of cell lines after DOC. Increases in stemness markers as well as mammosphere formation were observed after treatment with DOC suggesting an increase in the breast cancer stem cell populations. These increases were similar to that of cell lines cultured in the presence of recombinant SHH and could be eliminated by co‐treatment with HH inhibitors. These results suggest that HH pathway activation induced by DOC treatment does not have a chemosensitizing effect on the heterogeneous tumor population, but may be required for survival and expansion of breast cancer stem cells after chemotherapy.

Evaluating Outcomes of Electronic Tools Supporting Physician Shift-to-Shift Handoffs: A Systematic Review.

BACKGROUND Multiple organizations have recognized that handoffs are prone to errors, and there has been an increase in the use of electronic health records and computerized tools in health care. OBJECTIVE This systematic review evaluates the current evidence on the effectiveness of electronic solutions used to support shift-to-shift handoffs. METHODS We searched the English-language literature for research studies published between January 1, 2008, and September 19, 2014, using National Library of Medicine PubMed, EBSCO CINAHL, OvidSP All Journals, and ProQuest PsycINFO. Included studies focused on the evaluation of physician shift-to-shift handoffs and an electronic solution designed to support handoffs. We assessed articles using a quality scoring system, conducted a review of barriers and strategies, and categorized study outcomes into self-report, process, and outcome measures. RESULTS Thirty-seven articles met inclusion criteria, including 20 single group pre- and posttest studies; 8 posttest only or cross-sectional studies; 4 nonrandomized controlled trials; 1 cohort study; 1 randomized crossover study; and 3 qualitative studies. Quality scores ranged from 3.5 to 14 of a possible 16. Most articles documented some positive outcomes, with 2 of the 3 studies evaluating patient outcomes yielding statistically significant improvements. The only other study that analyzed patient outcomes showed that interventions other than the electronic tool were responsible for most of the significant improvements. CONCLUSIONS The majority of studies supported using an electronic tool, yet few measured patient outcomes, and numerous studies suffered from methodology issues. Future studies should evaluate patient outcomes, improve study design, assess the role of faculty oversight, and broaden the focus to recognize the role of human factors.

The Development of a Validated Checklist for Radial Arterial Line Placement Preliminary Results

Radial arterial line placement is an invasive procedure that may result in complications. Validated checklists are central to teaching and assessing procedural skills and may result in improved health care quality. The results of the first step of the validation of a radial arterial line placement checklist are described. A comprehensive literature review of articles published on radial arterial line placement did not yield a checklist validated by the Delphi method. A modified Delphi technique, involving a panel of 9 interdisciplinary, interinstitutional experts, was used to develop a radial arterial line placement checklist. The internal consistency coefficient using Cronbach α was .99. Developing a 22-item checklist for teaching and assessing radial arterial line placement is the first step in the validation process. For this checklist to become further validated, it should be implemented and studied in the simulation and clinical environments.

The Development of a Validated Checklist for Nasogastric Tube Insertion: Preliminary Results

Nasogastric (NG) tube insertion is known to result in complications. Validated checklists are central to teaching and assessing procedural skills and may result in improved health care quality. The results of the first step of the validation of an NG tube insertion checklist are described. A comprehensive literature review of articles published on NG tube insertion did not yield a checklist validated by the Delphi method. A modified Delphi technique, involving a panel of 9 interdisciplinary, interinstitutional experts, was used to develop an NG tube insertion checklist. The internal consistency coefficient using Cronbach’s α was .80. Developing a 19-item checklist for teaching and assessing NG tube insertion is the first step in the validation process. For this checklist to become further validated, it should be implemented and studied in the simulation and clinical environments.

Long Term, Low Dose Genistein decreases Stem Cell Populations and Sensitizes Inflammatory Breast Cancer Cell Lines to Radiation

Localrecurrenceininflammatorybreastcanceriscommonandisassociatedwithpoor� prognosis.�Recurrenceisdrivenbyasmallpopulationofradioresistantbreastcancercellsthat� havestem-likeproperties.�Previousstudieshaveshownthathighdosesofthesoyisoflavone� genisteinhaveagrowthinhibitoryeffectontumorcells,�andmaysensitizenon-inflammato - rybreastcancercellstoradiation.�Theobjectiveofthisstudywastodeterminetheeffectof� genisteinonthegrowthandradioresistanceofinflammatorybreastcancercells.�Weshowthat� short-termtreatmentofinflammatorycelllinesIBC3�andSUM149�withgenisteindecreases� cellproliferationandmammosphereformingabilityonlyatmicromolardoses,�buthadminimal� effectonstemcellmarkerexpressionandradioresistanceofthesecells.�However,�longterm� treatmentwithalowdose�(nM)�ofgenistein,�whichmaymimicdietaryintake,�decreasedstem� cellpopulationsandmammosphereformingabilityandincreasedradiation,�inducedcelldeath� intheselines.�Weproposethatdietaryintakeofgenisteinmaybeassociatedwithimprovedlo- calresponsetotreatmentininflammatorybreastcancerbydecreasinggrowthofbreastcancer� stemcells.

Patient Handoff Education: Are Medical Schools Catching Up?:

Communication errors during shift-to-shift handoffs are a leading cause of preventable adverse events. Nevertheless, handoff skills are variably taught at medical schools. The authors administered questionnaires on handoffs to interns during orientation. Questions focused on medical school handoff education, experiences, and perceptions. The majority (546/718) reported having some form of education on handoffs during medical school, with 48% indicating this was 1 hour or less. Most respondents (98%) reported that they believe patients experience adverse events because of inadequate handoffs, and more than one third had witnessed a patient safety issue. Results show that medical school graduates are not receiving adequate handoff training. Yet graduates are expected to conduct safe patient handoffs at the start of residency. Given that ineffective handoffs pose a significant patient safety risk, medical school graduates should have a baseline competency in handoff skills. This will require medical schools to develop, implement, and study handoff education.

The development of validated checklist for Foley catheterization: preliminary results.

Foley catheterization (FC) is known to result in complications. Validated checklists are central to teaching/assessing procedural skills and may result in improved health care quality. The results of the first step of the validation of male and female FC checklists are described. A comprehensive literature review of articles published on FC did not yield a checklist validated by the Delphi method. A modified Delphi technique involving a panel of 7 experts was used to develop FC checklists. The internal consistency coefficients using Cronbach’s α were .91 and .88, respectively, for males and females. Developing a 24-item male FC checklist and a 23-item female FC checklist for teaching/assessing FC is the first step in the validation process. For these checklists to become further validated, they should be implemented and studied in the simulation and the clinical environments.