Trends in adoption of extravascular cardiac implantable electronic devices:the Dutch cohort

Introduction: Conventional implantable cardioverter-defibrillators (ICDs) and pacemakers carry a risk of pocket- and lead-related complications in particular. To avoid these complications, extravascular devices (EVDs) have been developed, such as the subcutaneous ICD (S-ICD) and leadless pacemaker (LP). However, data on patient or centre characteristics related to the actual adoption of EVDs are lacking. Objective: To assess real-world nationwide trends in EVD adoption in the Netherlands. Methods: Using the Netherlands Heart Registration, all consecutive patients with a de novo S‑ICD or conventional single-chamber ICD implantation between 2012–2020, or de novo LP or conventional single-chamber pacemaker implantation between 2014–2020 were included. Trends in adoption are described for various patient and centre characteristics. Result: From 2012–2020, 2190 S‑ICDs and 10,683 conventional ICDs were implanted; from 2014–2020, 712 LPs and 11,103 conventional pacemakers were implanted. The general use has increased (S-ICDs 8 to 21%; LPs 1 to 8%), but this increase seems to have reached a plateau. S‑ICD recipients were younger than conventional ICD recipients (p &lt; 0.001) and more often female (p &lt; 0.001); LP recipients were younger than conventional pacemaker recipients (p &lt; 0.001) and more often male (p = 0.03). Both S‑ICDs and LPs were mainly implanted in high-volume centres with cardiothoracic surgery on-site, although over time S‑ICDs were increasingly implanted in centres without cardiothoracic surgery (p &lt; 0.001). Conclusion: This nationwide study demonstrated a relatively quick adoption of innovative EVDs with a plateau after approximately 4 years. S‑ICD use is especially high in younger patients. EVDs are mainly implanted in high-volume centres with cardiothoracic surgery back-up, but S‑ICD use is expanding beyond those centres.</p

Five-year safety and efficacy of leadless pacemakers in a Dutch cohort

BACKGROUND: Adequate real-world safety and efficacy of leadless pacemakers (LPs) have been demonstrated up to 3 years after implantation. Longer-term data are warranted to assess the net clinical benefit of leadless pacing.OBJECTIVE: The purpose of this study was to evaluate the long-term safety and efficacy of LP therapy in a real-world cohort.METHODS: In this retrospective cohort study, all consecutive patients with a first LP implantation from December 21, 2012, to December 13, 2016, in 6 Dutch high-volume centers were included. The primary safety endpoint was the rate of major procedure- or device-related complications (ie, requiring surgery) at 5-year follow-up. Analyses were performed with and without Nanostim battery advisory-related complications. The primary efficacy endpoint was the percentage of patients with a pacing capture threshold ≤2.0 V at implantation and without ≥1.5-V increase at the last follow-up visit.RESULTS: A total of 179 patients were included (mean age 79 ± 9 years), 93 (52%) with a Nanostim and 86 (48%) with a Micra VR LP. Mean follow-up duration was 44 ± 26 months. Forty-one major complications occurred, of which 7 were not advisory related. The 5-year major complication rate was 4% without advisory-related complications and 27% including advisory-related complications. No advisory-related major complications occurred a median 10 days (range 0-88 days) postimplantation. The pacing capture threshold was low in 163 of 167 patients (98%) and stable in 157 of 160 (98%).CONCLUSION: The long-term major complication rate without advisory-related complications was low with LPs. No complications occurred after the acute phase and no infections occurred, which may be a specific benefit of LPs. The performance was adequate with a stable pacing capture threshold.</p

A meta-analysis of state-of-the-art electoral prediction from Twitter data

Electoral prediction from Twitter data is an appealing research topic. It seems relatively straightforward and the prevailing view is overly optimistic. This is problematic because while simple approaches are assumed to be good enough, core problems are not addressed. Thus, this paper aims to (1) provide a balanced and critical review of the state of the art; (2) cast light on the presume predictive power of Twitter data; and (3) depict a roadmap to push forward the field. Hence, a scheme to characterize Twitter prediction methods is proposed. It covers every aspect from data collection to performance evaluation, through data processing and vote inference. Using that scheme, prior research is analyzed and organized to explain the main approaches taken up to date but also their weaknesses. This is the first meta-analysis of the whole body of research regarding electoral prediction from Twitter data. It reveals that its presumed predictive power regarding electoral prediction has been rather exaggerated: although social media may provide a glimpse on electoral outcomes current research does not provide strong evidence to support it can replace traditional polls. Finally, future lines of research along with a set of requirements they must fulfill are provided.Comment: 19 pages, 3 table

The effects of material formulation and manufacturing process on mechanical and thermal properties of epoxy/clay nanocomposites

A holistic study was conducted to investigate the combined effect of three different pre-mixing processes, namely mechanical mixing, ultrasonication and centrifugation, on mechanical and thermal properties of epoxy/clay nanocomposites reinforced with different platelet-like montmorillonite (MMT) clays (Cloisite Na+, Cloisite 10A, Cloisite 15 or Cloisite 93A) at clay contents of 3–10 wt%. Furthermore, the effect of combined pre-mixing processes and material formulation on clay dispersion and corresponding material properties of resulting composites was investigated using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), flexural and Charpy impact tests, Rockwell hardness tests and differential scanning calorimetry (DSC). A high level of clay agglomeration and partially intercalated/exfoliated clay structures were observed regardless of clay type and content. Epoxy/clay nanocomposites demonstrate an overall noticeable improvement of up to 10 % in the glass transition temperature (Tg) compared to that of neat epoxy, which is interpreted by the inclusion of MMT clays acting as rigid fillers to restrict the chain mobility of epoxy matrices. The impact strength of epoxy/clay nanocomposites was also found to increase by up to 24 % with the addition of 3 wt% Cloisite Na+ clays. However, their flexural strength and hardness diminished when compared to those of neat epoxy, arising from several effects including clay agglomeration, widely distributed microvoids and microcracks as well as weak interfacial bonding between clay particles and epoxy matrices, as confirmed from TEM and SEM results. Overall, it is suggested that an improved technique should be used for the combination of pre-mixing processes in order to achieve the optimal manufacturing condition of uniform clay dispersion and minimal void contents

Sliding Wear Behavior of Al2O3-TiO2 Coatings Fabricated by the Suspension Plasma Spraying Technique

[EN] The friction and dry sliding wear behavior of alumina and alumina-titania near-nanometric coatings were examined. Coatings were obtained by the suspension plasma spraying technique. Dry sliding wear tests were performed on a ball-on-disk tribometer, with an Al2O3 ball as counterpart material, a normal load of 2 N, a sliding distance of 1200 m and a sliding speed of 0.1 m/s. The effect of including TiO2 in the fabricated coatings on friction coefficient behavior, wear rates and wear damage patterns was determined. The addition of TiO2 to the coatings was found to greatly increase wear resistance by, for example, 2.6-fold for 40 wt% of TiO2. 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Protein docking prediction using predicted protein-protein interface

<p>Abstract</p> <p>Background</p> <p>Many important cellular processes are carried out by protein complexes. To provide physical pictures of interacting proteins, many computational protein-protein prediction methods have been developed in the past. However, it is still difficult to identify the correct docking complex structure within top ranks among alternative conformations.</p> <p>Results</p> <p>We present a novel protein docking algorithm that utilizes imperfect protein-protein binding interface prediction for guiding protein docking. Since the accuracy of protein binding site prediction varies depending on cases, the challenge is to develop a method which does not deteriorate but improves docking results by using a binding site prediction which may not be 100% accurate. The algorithm, named PI-LZerD (using Predicted Interface with Local 3D Zernike descriptor-based Docking algorithm), is based on a pair wise protein docking prediction algorithm, LZerD, which we have developed earlier. PI-LZerD starts from performing docking prediction using the provided protein-protein binding interface prediction as constraints, which is followed by the second round of docking with updated docking interface information to further improve docking conformation. Benchmark results on bound and unbound cases show that PI-LZerD consistently improves the docking prediction accuracy as compared with docking without using binding site prediction or using the binding site prediction as post-filtering.</p> <p>Conclusion</p> <p>We have developed PI-LZerD, a pairwise docking algorithm, which uses imperfect protein-protein binding interface prediction to improve docking accuracy. PI-LZerD consistently showed better prediction accuracy over alternative methods in the series of benchmark experiments including docking using actual docking interface site predictions as well as unbound docking cases.</p

Molecular dynamics of ribosomal elongation factors G and Tu

Translation on the ribosome is controlled by external factors. During polypeptide lengthening, elongation factors EF-Tu and EF-G consecutively interact with the bacterial ribosome. EF-Tu binds and delivers an aminoacyl-tRNA to the ribosomal A site and EF-G helps translocate the tRNAs between their binding sites after the peptide bond is formed. These processes occur at the expense of GTP. EF-Tu:tRNA and EF-G are of similar shape, share a common binding site, and undergo large conformational changes on interaction with the ribosome. To characterize the internal motion of these two elongation factors, we used 25 ns long all-atom molecular dynamics simulations. We observed enhanced mobility of EF-G domains III, IV, and V and of tRNA in the EF-Tu:tRNA complex. EF-Tu:GDP complex acquired a configuration different from that found in the crystal structure of EF-Tu with a GTP analogue, showing conformational changes in the switch I and II regions. The calculated electrostatic properties of elongation factors showed no global similarity even though matching electrostatic surface patches were found around the domain I that contacts the ribosome, and in the GDP/GTP binding region