Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO

The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages

The behavior of precipitates during hot-deformation of low-manganese, titanium-added pipeline steels

The behavior of manganese and titanium sulfides during the hot deformation of a low-carbon, low-manganese, titanium-added steel has been studied using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy-dispersive spectrometry (EDS) analysis. In addition, the effects of deformation temperature and strain rate on the size and distribution of precipitates have been studied using an automatic inclusion analysis system. Also, the effect of precipitate distribution on mechanical properties was studied at different deformation conditions of temperature and strain rate. The TEM and SEM analyses revealed the presence of a wide variety of simple and/or complex precipitates in the as-cast structure. These precipitates behaved differently during the hot deformation of steel. Precipitates deformed less at higher deformation temperatures, whereas an increase in strain rate increased the elongation of precipitates

Computational Methods for Complex Stochastic Systems: A Review of Some Alternatives to MCMC.

We consider analysis of complex stochastic models based upon partial information. MCMC and reversible jump MCMC are often the methods of choice for such problems, but in some situations they can be difficult to implement; and suffer from problems such as poor mixing, and the difficulty of diagnosing convergence. Here we review three alternatives to MCMC methods: importance sampling, the forward-backward algorithm, and sequential Monte Carlo (SMC). We discuss how to design good proposal densities for importance sampling, show some of the range of models for which the forward-backward algorithm can be applied, and show how resampling ideas from SMC can be used to improve the efficiency of the other two methods. We demonstrate these methods on a range of examples, including estimating the transition density of a diffusion and of a discrete-state continuous-time Markov chain; inferring structure in population genetics; and segmenting genetic divergence data

TEM characterization of precipitates in the segregated regions of a low-carbon, low-manganese, titanium-added steel

A concentric solidification technique has been employed to simulate sulphide precipitation at the centreline of a continuously cast low-carbon, low-manganese, titanium-added steel slab. Selected precipitates were identified using transmission electron microscopy following sample preparation by focused ion beam milling techniques. FeTiS2 and hexagonal MnS containing iron atoms form in close proximity to each other in super-saturated areas of the concentrically solidified sample. The presence of FeTiS2 precipitates in low-carbon steel has been verified for the first time, and the crystal structure determined by electron diffraction analysis as a trigonal CdI2-type with a P3 m1 space group and lattice parameters of a= 0.341 nm and c= 0.569 nm

Dissolution of chromium-enriched inclusions and pitting corrosion of resulfurized stainless steels.

The dissolution of MnS inclusions enriched in chromium (30 to 40 wt pct Cr) and the corrosion susceptibility of resulfurized stainless steel were studied in various NaCl- and NaClO4-based solutions by X-ray photoelectron spectroscopy, secondary ion mass spectroscopy, scanning electron microscopy (SEM), and the electrochemical microcell technique. It has been shown that chromium-enriched inclusions do not undergo dissolution under free corrosion conditions. By contrast, electrochemical dissolution of inclusions occurs at high potential values (above 500 mV vs saturated calomel electrode) in all the solutions, followed by stable pitting. It has also been shown that some areas containing chromium-enriched inclusions exhibited stable pitting at low potentials (below 100 mV vs saturated calomel electrode) in the electrolytes with chloride ions. Field-emission SEM experiments have revealed that the matrix undergoes dissolution around these inclusions. An assumption is proposed for describing pitting corrosion mechanisms