4,831 research outputs found
Usual Tumor at an Unusual Site - A Leiomyoma Masquerading as a Urethral Polyp.
Polyps and papillomas encompass the most common benign tumors of the urethra.Leiomyoma of urethra is a rare clinical entity which can be diagnosed only with histopathological examination and only around 35 such cases have been reported worldwide
Application of Bayesian graphs to SN Ia data analysis and compression
Bayesian graphical models are an efficient tool for modelling complex data
and derive self-consistent expressions of the posterior distribution of model
parameters. We apply Bayesian graphs to perform statistical analyses of Type Ia
supernova (SN Ia) luminosity distance measurements from the joint light-curve
analysis (JLA) data set. In contrast to the approach used in previous
studies, the Bayesian inference allows us to fully account for the
standard-candle parameter dependence of the data covariance matrix. Comparing
with analysis results, we find a systematic offset of the marginal
model parameter bounds. We demonstrate that the bias is statistically
significant in the case of the SN Ia standardization parameters with a maximal
6 shift of the SN light-curve colour correction. In addition, we find
that the evidence for a host galaxy correction is now only 2.4 .
Systematic offsets on the cosmological parameters remain small, but may
increase by combining constraints from complementary cosmological probes. The
bias of the analysis is due to neglecting the parameter-dependent
log-determinant of the data covariance, which gives more statistical weight to
larger values of the standardization parameters. We find a similar effect on
compressed distance modulus data. To this end, we implement a fully consistent
compression method of the JLA data set that uses a Gaussian approximation of
the posterior distribution for fast generation of compressed data. Overall, the
results of our analysis emphasize the need for a fully consistent Bayesian
statistical approach in the analysis of future large SN Ia data sets.Comment: 14 pages, 13 figures, 5 tables. Submitted to MNRAS. Compression
utility available at https://gitlab.com/congma/libsncompress/ and example
cosmology code with machine-readable version of Tables A1 & A2 at
https://gitlab.com/congma/sn-bayesian-model-example/ v2: corrected typo in
author's name. v3: 15 pages, incl. corrections, matches the accepted versio
Trunk muscle training, posture fatigue, and performance in laparoscopic surgery
Purpose: To investigate the effect of trunk muscle endurance training on the perception of back postural fatigue and performance of a laparoscopic task. Materials and Methods: Thirty-one medical students (18 men and 13 women) with no laparoscopic surgical experience were randomly assigned to either a training group or a control group. Participants in the training group underwent a 6-week, 18-session trunk (abdominal and back muscle) endurance training program, whereas participants in the control group did not. Performance by all participants was assessed on a simulated laparoscopic task under varying conditions of low back postural fatigue, both before and after the training program. Results: Participants in the training group showed significant improvements in trunk endurance after the 6-week trunk endurance training program (P 0.05). Conclusion: Increasing trunk endurance can reduce postural fatigue and discomfort during simulated laparoscopic tasks, which may assist in the management of errors during laparoscopy. © Mary Ann Liebert, Inc. 2008.published_or_final_versio
Renormalization group approach to multiparticle density fluctuations
An iterative procedure is developed with the aim of constructing homogeneity
rules for the distribution P(rho,delta) of the particle density rho at
resolution scale delta. A single iteration step consists of a change in the
normalization point of P(rho,delta) followed by a rescaling. Similar
transformation rule is introduced for density fluctuations contaminated by
Poisson noise. Application of the iterative procedure is given for the
Ginzburg-Landau description of phase-transition from the quark-gluon plasma and
for random cascading models.Comment: 11 pages REVTeX, 1 figure include
A proposal for detecting the spin of a single electron in superfluid helium
The electron bubble in superfluid helium has two degrees of freedom that may
offer exceptionally low dissipation: the electron's spin and the bubble's
motion. If these degrees of freedom can be read out and controlled with
sufficient sensitivity, they would provide a novel platform for realizing a
range of quantum technologies and for exploring open questions in the physics
of superfluid helium. Here we propose a practical scheme for accomplishing this
by trapping an electron bubble inside a superfluid-filled opto-acoustic cavity.Comment: Main text: 5 pages, 5 figures. Supplement: 11 pages, 2 figures, 1
tabl
Photoluminescent arginineâfunctionalized polycitrate with enhanced cell activity and hemocompatibility for live cell bioimaging
Development of biodegradable and highly biocompatible polymer with intrinsical photoluminescence and high photostability for realâtime live cell bioimaging has attracted much attention recently. Here, a biodegradable and amphiphilic poly (citrate)âcoâpoly (ethylene glycol) (PEG) grafted with arginine (PCGA) polymer with intrinsical fluorescence was synthesized for targeted live cell bioimaging. The physicochemical structure, photoluminescent properties, hemocompatibility, cytotoxicity, and fluorescent bioimaging studies in live cells were determined in detail. PCGA showed a significantly high hemocompatibility, low cytotoxicity, and excellent photostability, which allows for imaging the live cells attachment and proliferation. Furthermore, PCGA could efficiently enhance cell attachment and proliferation due to the presence of arginine, suggesting their high cellular biocompatibility. Importantly, PCGA could selectively stain the lysosome in cells. Our results demonstrated that the amino acidâbased polymer functionalization may be an important strategy to develop multifunctional biomaterials with enhanced biocompatibility for targeted bioimaging, cancer therapy, and regenerative medicine. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 3175â3184, 2018.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146603/1/jbma36512.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146603/2/jbma36512_am.pd
Non-Thermal Plasma Activation of Gold-Based Catalysts for Low-Temperature Water-Gas Shift Catalysis
Acknowledgements The UK Catalysis Hub is kindly thanked for resources and support provided via our membership of the UK Catalysis Hub Consortium and funded by EPSRC (Portfolio Grants EP/K014706/2, EP/K014668/1, EP/K014854/1, EP/K014714/1, and EP/I019693/1). Open access data can be found via the University of Manchester research portal. We are grateful to Helen Daly (Queen's University Belfast) for discussion, to Fabio de Rosa (Queen's University Belfast) for the thermodynamic equilibrium calculations (obtained using the Convergence tool of Aspen Plus 8.0) and to Emma Gibson (Harwell Research Complex) for the BET measurements. JJ Delgado is grateful to Ramon y Cajal program and the Ce-NanoSurPhases project grant from MINECO.Peer reviewedPostprintPostprintPublisher PD
Peanut oral immunotherapy transiently expands circulating Ara h 2âspecific B cells with a homologous repertoire in unrelated subjects
Background
Peanut oral immunotherapy (PNOIT) induces persistent tolerance to peanut in a subset of patients and induces specific antibodies that might play a role in clinical protection. However, the contribution of induced antibody clones to clinical tolerance in PNOIT is unknown.
Objective
We hypothesized that PNOIT induces a clonal, allergen-specific B-cell response that could serve as a surrogate for clinical outcomes.
Methods
We used a fluorescent Ara h 2 multimer for affinity selection of Ara h 2âspecific B cells and subsequent single-cell immunoglobulin amplification. The diversity of related clones was evaluated by means of next-generation sequencing of immunoglobulin heavy chains from circulating memory B cells with 2x250 paired-end sequencing on the Illumina MiSeq platform.
Results
Expression of class-switched antibodies from Ara h 2âpositive cells confirms enrichment for Ara h 2 specificity. PNOIT induces an early and transient expansion of circulating Ara h 2âspecific memory B cells that peaks at week 7. Ara h 2âspecific sequences from memory cells have rates of nonsilent mutations consistent with affinity maturation. The repertoire of Ara h 2âspecific antibodies is oligoclonal. Next-generation sequencingâbased repertoire analysis of circulating memory B cells reveals evidence for convergent selection of related sequences in 3 unrelated subjects, suggesting the presence of similar Ara h 2âspecific B-cell clones.
Conclusions
Using a novel affinity selection approach to identify antigen-specific B cells, we demonstrate that the early PNOIT-induced Ara h 2âspecific B-cell receptor repertoire is oligoclonal and somatically hypermutated and shares similar clonal groups among unrelated subjects consistent with convergent selection.
Key words
Immunotherapy; antigen-specific B cells; peanut allergy; food allergy; antibody repertoire
Abbreviations used
APC, Allophycocyanin; BCR, B-cell receptor; CDR, Complementarity-determining region; NGS, Next-generation sequencing; OIT, Oral immunotherapy; PNOIT, Peanut oral immunotherapyNational Institute of Allergy and Infectious Diseases (U.S.) (NIAID U19 AI087881)National Institute of Allergy and Infectious Diseases (U.S.) (NIAID U19 AI095261)United States. National Institutes of Health (1S10RR023440-01A1)National Institute of Allergy and Infectious Diseases (U.S.) (NIAID F32 AI104182)United States. National Institutes of Health (UL1 TR001102
Dealing with missing standard deviation and mean values in meta-analysis of continuous outcomes: a systematic review
Background: Rigorous, informative meta-analyses rely on availability of appropriate summary statistics or individual
participant data. For continuous outcomes, especially those with naturally skewed distributions, summary
information on the mean or variability often goes unreported. While full reporting of original trial data is the ideal,
we sought to identify methods for handling unreported mean or variability summary statistics in meta-analysis.
Methods: We undertook two systematic literature reviews to identify methodological approaches used to deal with
missing mean or variability summary statistics. Five electronic databases were searched, in addition to the Cochrane
Colloquium abstract books and the Cochrane Statistics Methods Group mailing list archive. We also conducted cited
reference searching and emailed topic experts to identify recent methodological developments. Details recorded
included the description of the method, the information required to implement the method, any underlying
assumptions and whether the method could be readily applied in standard statistical software. We provided a
summary description of the methods identified, illustrating selected methods in example meta-analysis scenarios.
Results: For missing standard deviations (SDs), following screening of 503 articles, fifteen methods were identified in
addition to those reported in a previous review. These included Bayesian hierarchical modelling at the meta-analysis
level; summary statistic level imputation based on observed SD values from other trials in the meta-analysis; a practical
approximation based on the range; and algebraic estimation of the SD based on other summary statistics. Following
screening of 1124 articles for methods estimating the mean, one approximate Bayesian computation approach and
three papers based on alternative summary statistics were identified. Illustrative meta-analyses showed that when
replacing a missing SD the approximation using the range minimised loss of precision and generally performed better
than omitting trials. When estimating missing means, a formula using the median, lower quartile and upper quartile
performed best in preserving the precision of the meta-analysis findings, although in some scenarios, omitting trials
gave superior results.
Conclusions: Methods based on summary statistics (minimum, maximum, lower quartile, upper quartile, median)
reported in the literature facilitate more comprehensive inclusion of randomised controlled trials with missing mean or
variability summary statistics within meta-analyses
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