103 research outputs found

    Reamer Irrigator Aspirator intraoperative ruler accuracy of femoral isthmus diameter

    Get PDF
    Introduction: Over the past two decades, bone graft harvest with the Reamer Irrigator Aspirator (RIA) from the femoral canal has grown in popularity. Intra-operative measurement of the femoral canal is taken with a metallic ruler (RIA ruler) in conjunction with C-arm fluoroscopy.Research Question/Hypothesis: Our study aims to evaluate the accuracy of the RIA ruler in judging the femoral canal diameter compared to two other measurements.Study Design: Utilizing 6 fresh frozen human cadavers, each cadaveric femur is imaged in the operative suite in the supine position with C-Arm fluoroscopy. The femoral diameter is then measured with the RIA ruler in AP and lateral plane at all three reference points by multiple surgeons. CT scans of each individual femur were then performed. The cadaveric femurs were then transected at all the guide pins and direct caliper measurements were taken in the AP and Lateral plane.Results: There was no significant difference in mean AP diameter measured by CT canal measurement and Canal Caliper measurement (p=0.6276). Our AP measurements using the RIA ruler were similar to those of both the CT canal and canal caliper (13.000mm vs 12.167mm vs 12.439mm) respectively. Additionally, our lateral measurements were very similar between the RIA ruler and CT canal (14.644mm vs 14.606mm), however lateral RIA ruler measurements were significantly different than the canal caliper method (14.644mm vs 11.947mm).Conclusion: Our results suggest we are able to reliably estimate the femoral canal size near the isthmus with the RIA ruler on both the AP and Lateral images compared to the CT scan measurements

    Reliability of posterolateral acromion process to examination table measurement to estimate shoulder protraction contracture

    Get PDF
    Study Design: Retrospective study. Objectives: To determine the reliability of measuring the perpendicular distance between the posterolateral acromion process and examination table to estimate passive shoulder protraction in student physical therapists. Background: Previous research has identified scapular dyskinesis to be associated with musculoskeletal shoulder pain, and commonly addressed by physical therapists. Tightness of the anterior shoulder muscles may be associated with scapular movement abnormality. Thus, reliable clinical measurements for anterior shoulder muscle length are imporrant for physical therapy care. Methods: After a 1 0-minute review session, two measurements of the distance between the posterior acromion process and examination table were obtained for both the dominant shoulders and nondominant shoulders in 12 nondisabled individuals (6 females, and 6 males age: 25.0 ± 2.4 years) by 12 student physical therapist examiners. A complete set of measurements from 10 subjects were available for analysis. Results: Mean (±standard deviation) measurements for the dominant (D) shoulder were 7.6 ± 2.0cm for Trial #1 and 7.4 ± 2.0 em for Trial #2, and 7.5 ± 2.lcm for Trial #l and 7.4 ± 2.3cm for Trial #2 for the nondominant (ND) shoulder. Tightness was determined in 85% and 86% for D and ND shoulders, respectively. The measurement demonstrated good intra-rater reliability (D: intradass correlation, formula 2,1; ICC2 _ 1 .751, 95% confidence interval; Cl: .628-.861; ND: .764, 95% CI: .645-.869) and moderate to good inter-rater reliability (D: ICC2 , 1 .651, 95% CI: .445-.876; ND: ICC2‱1 = .733, 95% CI: .548-.911) considered as a continuous variable, \u3c}nd good percent agreement both within raters (94%) and between raters (90%) as a binomial variable. The coefficient of variation was acceptable (D: 25.8, ND: 28.4%). Standard error of measure was 0.99 em for D shoulders and 1.01 em for ND shoulders. Minimum detectable change outside the 95% confidence interval was 2.74 em forD shoulders and 2.80 em for ND shoulders. Conclusion: Measurement of the perpendicular distance between the posterolateral acromion process and examination table is a reliable method to estimate passive shoulder protraction in novice clinicians

    The UNC-6/Netrin receptors UNC-40/DCC and UNC-5 inhibit growth cone filopodial protrusion via UNC-73/Trio, Rac-like GTPases and UNC-33/CRMP

    Get PDF
    UNC-6/Netrin is a conserved axon guidance cue that can mediate both attraction and repulsion. We previously discovered that attractive UNC-40/DCC receptor signaling stimulates growth cone filopodial protrusion and that repulsive UNC-40–UNC-5 heterodimers inhibit filopodial protrusion in C. elegans. Here, we identify cytoplasmic signaling molecules required for UNC-6-mediated inhibition of filopodial protrusion involved in axon repulsion. We show that the Rac-like GTPases CED-10 and MIG-2, the Rac GTP exchange factor UNC-73/Trio, UNC-44/Ankyrin and UNC-33/CRMP act in inhibitory UNC-6 signaling. These molecules were required for the normal limitation of filopodial protrusion in developing growth cones and for inhibition of growth cone filopodial protrusion caused by activated MYR::UNC-40 and MYR::UNC-5 receptor signaling. Epistasis studies using activated CED-10 and MIG-2 indicated that UNC-44 and UNC-33 act downstream of the Rac-like GTPases in filopodial inhibition. UNC-73, UNC-33 and UNC-44 did not affect the accumulation of full-length UNC-5::GFP and UNC-40::GFP in growth cones, consistent with a model in which UNC-73, UNC-33 and UNC-44 influence cytoskeletal function during growth cone filopodial inhibition.We thank E. Struckhoff for technical assistance and J. Culotti for kindly providing the pU5GFP plasmid. Some strains were provided by the CGC, which is funded by the NIH Office of Research Infrastructure Programs [P40OD010440]

    Electrochemical Oxidation of Metal Carbides in Aqueous Solutions

    Get PDF
    Transition metal carbides have unique properties such as high hardness, high melting temperatures, high thermal conductivity, and high chemical stability. In this report, we investigate the electrochemical oxidation of a series of metal carbides including NbC, Nb2C, TaC, Ta2C, VC, VCrC, TiC and TiCrC in neutral, basic, or acidic aqueous solutions. Cyclic voltammetry and elemental analysis demonstrated that many of these metal carbides can be electrochemically oxidized at low electrode potentials to produce soluble metal ions in the solutions. Carbon in the metal carbides remains on the electrode substrates and forms porous carbide-derived carbon (CDC). The surface morphology of the CDC and specific surface area depend on the metal carbide precursors and the electrochemical oxidation conditions

    Ebola and Marburg virus matrix layers are locally ordered assemblies of VP40 dimers.

    Get PDF
    Filoviruses such as Ebola and Marburg virus bud from the host membrane as enveloped virions. This process is achieved by the matrix protein VP40. When expressed alone, VP40 induces budding of filamentous virus-like particles, suggesting that localization to the plasma membrane, oligomerization into a matrix layer, and generation of membrane curvature are intrinsic properties of VP40. There has been no direct information on the structure of VP40 matrix layers within viruses or virus-like particles. We present structures of Ebola and Marburg VP40 matrix layers in intact virus-like particles, and within intact Marburg viruses. VP40 dimers assemble extended chains via C-terminal domain interactions. These chains stack to form 2D matrix lattices below the membrane surface. These lattices form a patchwork assembly across the membrane and suggesting that assembly may begin at multiple points. Our observations define the structure and arrangement of the matrix protein layer that mediates formation of filovirus particles

    Information mobility in complex networks

    Get PDF
    The concept of information mobility in complex networks is introduced on the basis of a stochastic process taking place in the network. The transition matrix for this process represents the probability that the information arising at a given node is transferred to a target one. We use the fractional powers of this transition matrix to investigate the stochastic process at fractional time intervals. The mobility coefficient is then introduced on the basis of the trace of these fractional powers of the stochastic matrix. The fractional time at which a network diffuses 50% of the information contained in its nodes (1/ k50 ) is also introduced. We then show that the scale-free random networks display better spread of information than the non scale-free ones. We study 38 real-world networks and analyze their performance in spreading information from their nodes. We find that some real-world networks perform even better than the scale-free networks with the same average degree and we point out some of the structural parameters that make this possible

    Heteroresistance to the model antimicrobial peptide polymyxin B in the emerging Neisseria meningitidis lineage 11.2 urethritis clade: mutations in the pilMNOPQ operon

    Get PDF
    Clusters of Neisseria meningitidis (Nm) urethritis among primarily heterosexual males in multiple US cities have been attributed to a unique non‐encapsulated meningococcal clade (the US Nm urethritis clade, US_NmUC) within the hypervirulent clonal complex 11. Resistance to antimicrobial peptides (AMPs) is a key feature of urogenital pathogenesis of the closely related species, Neisseria gonorrhoeae. The US_NmUC isolates were found to be highly resistant to the model AMP, polymyxin B (PmB, MICs 64–256 ”g ml–1). The isolates also demonstrated stable subpopulations of heteroresistant colonies that showed near total resistant to PmB (MICs 384–1024 ”g ml–1) and colistin (MIC 256 ”g ml–1) as well as enhanced LL‐37 resistance. This is the first observation of heteroresistance in N. meningitidis. Consistent with previous findings, overall PmB resistance in US_NmUC isolates was due to active Mtr efflux and LptA‐mediated lipid A modification. However, whole genome sequencing, variant analyses and directed mutagenesis revealed that the heteroresistance phenotypes and very high‐level AMP resistance were the result of point mutations and IS1655 element movement in the pilMNOPQ operon, encoding the type IV pilin biogenesis apparatus. Cross‐resistance to other classes of antibiotics was also observed in the heteroresistant colonies. High‐level resistance to AMPs may contribute to the pathogenesis of US_NmUC

    Validating the Psychosocial Functioning during COVID-19 Questionnaire among a Sample of Informal Caregivers

    Get PDF
    The COVID-19 pandemic has had a dramatic impact on global economies and societies. Although social distancing policies are needed to contain the spread and impact of COVID-19, they also impose a psychological and economic burden on people who are already experiencing increased distress such as caregivers. Yet, few measures have been developed and validated to measure the psychosocial impact of COVID-19. Utilizing item response theory (IRT), the purpose of this study was to develop and psychometrically validate a measure of psychosocial functioning—the Psychosocial Functioning during COVID-19 (PFC-19) Questionnaire—to assess changes in social interaction, mental health, health behavior, and global functioning among a sample of informal caregivers during the COVID-19 pandemic. The analytic sample (n = 733) was recruited from Amazon Mechanic Turk (MTurk) (69% male, 55% white). Results suggest a two-factor measure, assessing global functioning (14 items) and affective response (8 items), with strong evidence for reliability, validity, and dimensionality. Future research should replicate this factor structure in other samples
    • 

    corecore