For several decades, composites made of polylactic acid-calcium phosphates (PLA-CaP) and polylactic acid-co-glycolic acid-calcium phosphates (PLGA-CaP) have seen widespread uses in orthopedic ...applications. This paper reviews the fabrication aspects of these composites, following the ubiquitous materials science approach by studying “processing–structure–property” correlations. Various fabrication processes such as microencapsulation, phase separation, electrospinning, supercritical gas foaming, etc., are reviewed, with specific examples of their applications in fabricating these composites. The effect of the incorporation of CaP materials on the mechanical and biological performance of PLA/PLGA is addressed. In addition, this paper describes the state of the art on challenges and innovations concerning CaP dispersion, incorporation of biomolecules/stem cells and long-term degradation of the composites.
Many sample size criteria exist. These include power calculations and methods based on confidence interval widths from a frequentist viewpoint, and Bayesian methods based on credible interval widths ...or decision theory. Bayesian methods account for the inherent uncertainty of inputs to sample size calculations through the use of prior information rather than the point estimates typically used by frequentist methods. However, the choice of prior density can be problematic because there will almost always be different appreciations of the past evidence. Such differences can be accommodated a priori by robust methods for Bayesian design, for example, using mixtures or ϵ‐contaminated priors. This would then ensure that the prior class includes divergent opinions. However, one may prefer to report several posterior densities arising from a “community of priors,” which cover the range of plausible prior densities, rather than forming a single class of priors. To date, however, there are no corresponding sample size methods that specifically account for a community of prior densities in the sense of ensuring a large‐enough sample size for the data to sufficiently overwhelm the priors to ensure consensus across widely divergent prior views. In this paper, we develop methods that account for the variability in prior opinions by providing the sample size required to induce posterior agreement to a prespecified degree. Prototypic examples to one‐ and two‐sample binomial outcomes are included. We compare sample sizes from criteria that consider a family of priors to those that would result from previous interval‐based Bayesian criteria.
We shall use this introduction to the Faraday Discussion on quantum effects in complex systems to review the recent progress that has been made in using imaginary time path integral methods to ...calculate chemical reaction rates. As a result of this progress, it is now routinely possible to calculate accurate rate constants including quantum mechanical zero point energy and tunnelling effects for arbitrarily complex (anharmonic and multi-dimensional) systems. This is true in the adiabatic (Born-Oppenheimer) limit, in the non-adiabatic (Fermi Golden Rule) limit, and everywhere between these two limits in the normal Marcus regime. Quantum mechanical effects on reaction rates can be enormous, even at room temperature, and the problem of including these effects in simulations of a wide variety of chemical reactions in complex systems has now effectively been solved.
We shall use this introduction to the Faraday Discussion on quantum effects in complex systems to review the recent progress that has been made in using imaginary time path integral methods to calculate chemical reaction rates.
Rapid and point-of-care (POC) tests for syphilis are an invaluable screening tool, yet inadequate evaluation of their diagnostic accuracy against best reference standards limits their widespread ...global uptake. To fill this gap, a systematic review and meta-analysis was conducted to evaluate the sensitivity and specificity of rapid and POC tests in blood and serum samples against Treponema pallidum (TP) specific reference standards.
Five electronic databases (1980-2012) were searched, data was extracted from 33 articles, and Bayesian hierarchical models were fit.
In serum samples, against a TP specific reference standard point estimates with 95% credible intervals (CrI) for the sensitivities of popular tests were: i) Determine, 90.04% (80.45, 95.21), ii) SD Bioline, 87.06% (75.67, 94.50), iii) VisiTect, 85.13% (72.83, 92.57), and iv) Syphicheck, 74.48% (56.85, 88.44), while specificities were: i) Syphicheck, 99.14% (96.37, 100), ii) Visitect, 96.45% (91.92, 99.29), iii) SD Bioline, 95.85% (89.89, 99.53), and iv) Determine, 94.15% (89.26, 97.66). In whole blood samples, sensitivities were: i) Determine, 86.32% (77.26, 91.70), ii) SD Bioline, 84.50% (78.81, 92.61), iii) Syphicheck, 74.47% (63.94, 82.13), and iv) VisiTect, 74.26% (53.62, 83.68), while specificities were: i) Syphicheck, 99.58% (98.91, 99.96), ii) VisiTect, 99.43% (98.22, 99.98), iii) SD Bioline, 97.95%(92.54, 99.33), and iv) Determine, 95.85% (92.42, 97.74).
Rapid and POC treponemal tests reported sensitivity and specificity estimates comparable to laboratory-based treponemal tests. In resource limited settings, where access to screening is limited and where risk of patients lost to follow up is high, the introduction of these tests has already been shown to improve access to screening and treatment to prevent stillbirths and neonatal mortality due to congenital syphilis. Based on the evidence, it is concluded that rapid and POC tests are useful in resource limited settings with poor access to laboratories or screening for syphilis.
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