Three-dimensional analysis of microporous and fine-grained particles in natural stone is important for understanding their internal fluid flow processes and to allow their internal dynamics to be ...modeled. These processes are of great interest in oil, gas and groundwater studies, as well as for the weathering of natural building materials. For features above 1μm methods such as X-ray micro-computed tomography (μ-CT) can provide non-destructive, quantitative analysis. Non-destructive 3D imaging at resolutions below 300–400nm, however, has remained a challenge until recent developments at synchrotron beam lines. In this paper we visualize the microstructure of clay mineral samples extracted from two different sandstones at 3D spatial resolutions down to 45nm, using ptychographic X-ray computed tomography (PXCT). Furthermore, the relative humidity of the environment during these experiments was controlled in order to assess its influence on the analyzed samples. Based on these high-quality images, we were able to acquire non-destructively quantitative 3D information on mineral content and distribution, porosity and connectivity of clay mineral clusters inside sandstone.
•We show high-resolution 3D imaging of clay minerals extracted from sandstones.•Resolutions up to 45nm were obtained.•Samples were imaged non-destructively.•The behavior of the clay minerals under changing relative humidity could be studied.•The images provided chemical information about the composition of the clay minerals.
Abstract
In this work, we present a novel laboratory‐based microcomputed tomography (micro‐CT) experiment designed to investigate the pore‐scale drainage behavior of natural sandstone under dynamic ...conditions. The fluid distribution in a Bentheimer sandstone was visualized every 4 s with a 12 s measurement time, allowing the investigation of single‐pore and few‐pore‐filling events. To our knowledge, this is the first time that such measurements were performed outside of synchrotron facilities, illustrating the growing application potential of laboratory‐based micro‐CT with subminute temporal resolutions for geological research at the pore scale. To illustrate how the workflow can lead to an improved understanding of drainage behavior, the experiment was analyzed using a decomposition of the pore space into individual geometrical pores. Preliminary results from this analysis suggest that the distribution of drainage event sizes follows a power law scaling, as expected from percolation theory.
Key Points:
Drainage in sandstone was visualized with bench‐top micro‐CT scanner at 12 s/scan
Single‐pore and multiple pore‐filling events were analyzed by tracking gray values in individual pores
Methods presented here allow to inspect the validity of percolation theory to describe the invasion
The study aimed to evaluate the adequacy and feasibility of the single string bifurcation stenting technique.
Double-stent techniques may be required for complex bifurcations. Currently applied ...methods all have their morphological or structural limitations with respect to wall coverage, multiple strut layers, and apposition rate.
Single string is a novel method in which, first, the side branch (SB) stent is deployed with a single stent cell protruding into the main branch (MB). Second, the MB stent is deployed across this protruding stent cell. The procedure is completed by final kissing balloon dilation. The single string technique was first tested in vitro (n = 20) and next applied in patients (n = 11) with complex bifurcation stenoses.
All procedures were performed successfully, crossing a single stent cell in 100%. Procedure duration was 23.0 ± 7.9 min, and the fluoroscopy time was 9.4 ± 3.5 min. The results were evaluated by optical coherence tomography, showing fully apposed struts in 83.0 ± 9.2% in the bifurcation area. Residual area obstruction in the MB was 6.4 ± 5.6% and 25.0 ± 16.9% in the SB, as evaluated by micro computed tomography. All the human cases were performed successfully with excellent angiographic results: the residual area stenosis was 27 ± 8% and 29 ± 10% in the MB and in the SB, respectively, by 3-dimensional quantitative coronary angiography. No relevant periprocedural enzyme increase was observed. During follow-up (6 ± 4 months), no adverse clinical events (death, myocardial infarction, target vessel revascularization) were noted.
The single string technique for complex bifurcation dilation was shown to be adequate in vitro and feasible in humans, with favorable results in terms of stent overlap, malapposition rate, and low residual obstruction in both the MB and SB.
Corrigendum : A multilevel framework to reconstruct anatomical 3D models of the hepatic vasculature in rat livers.These are the new list of the authors and their affiliation.
Halting current rates of biodiversity loss will be a defining challenge of the 21st century. To assess the effectiveness of strategies to achieve this goal, indicators and tools are required that ...monitor the driving forces of biodiversity loss, the changing state of biodiversity, and evaluate the effectiveness of policy responses. Here, we review the use of indicators and approaches to model biodiversity loss in Life Cycle Assessment (LCA), a methodology used to evaluate the cradle-to-grave environmental impacts of products. We find serious conceptual shortcomings in the way models are constructed, with scale considerations largely absent. Further, there is a disproportionate focus on indicators that reflect changes in compositional aspects of biodiversity, mainly changes in species richness. Functional and structural attributes of biodiversity are largely neglected. Taxonomic and geographic coverage remains problematic, with the majority of models restricted to one or a few taxonomic groups and geographic regions. On a more general level, three of the five drivers of biodiversity loss as identified by the Millennium Ecosystem Assessment are represented in current impact categories (habitat change, climate change and pollution), while two are missing (invasive species and overexploitation). However, methods across all drivers can be greatly improved. We discuss these issues and make recommendations for future research to better reflect biodiversity loss in LCA.
The possibility to assess psychopathy through self-report is debated, amongst others, because psychopathic individuals may deliberately underreport psychopathic features (fake good). Meta-analytic ...research has shown an inverse relation between faking good and self-reported psychopathy, possibly indicating that faking good lowered psychopathy scores (response bias). Low faking good scores, could, however, also reflect true variance in psychopathic personality to the extent that it reflects a disregard of social conventions. Through a secondary analysis (n = 675), we show that controlling for faking good significantly weakens, rather than strengthens, the associations between psychopathy scores and antisocial behavior (alcohol and drug abuse, indirect aggression, and delinquency). These findings indicate that the inverse relation between faking good and self-reported psychopathy reflects true variance in psychopathy personality (i.e. low social desirability), not a response bias.
The European Medicines Agency (EMA) calls for a strategy for enhanced safety surveillance of seasonal influenza vaccines.
We assessed the feasibility of collecting reactogenicity data within one ...month of the start of the vaccination campaign in Belgium.
One hundred subjects aged 18 to 65 years who had received inactivated seasonal influenza vaccine in occupational setting were enrolled. For 7 days after vaccination, subjects received a daily SMS with a link to a web-based questionnaire where reactogenicity events and their severity were solicited.
Data collection was completed by October 13th, 2016, before the peak of the vaccination campaign in Belgium. 68% of participants reported a local reaction and 65% a general reaction; 51% reported both a local and a general reaction.
Here we show that it has been possible to collect reactogenicity data in adults for enhanced safety surveillance in Belgium in a timely manner. The observed reactogenicity is higher compared to previous observations for this vaccine measured in clinical trials.
Abstract
Background
Ventilator-associated pneumonia caused by
Pseudomonas aeruginosa
(PA) in hospitalised patients is associated with high mortality. The effectiveness of the bivalent, bispecific mAb ...MEDI3902 (gremubamab) in preventing PA nosocomial pneumonia was assessed in PA-colonised mechanically ventilated subjects.
Methods
EVADE (NCT02696902) was a phase 2, randomised, parallel-group, double-blind, placebo-controlled study in Europe, Turkey, Israel, and the USA. Subjects ≥ 18 years old, mechanically ventilated, tracheally colonised with PA, and without new-onset pneumonia, were randomised (1:1:1) to MEDI3902 500, 1500 mg (single intravenous dose), or placebo. The primary efficacy endpoint was the incidence of nosocomial PA pneumonia through 21 days post-dose in MEDI3902 1500 mg versus placebo, determined by an independent adjudication committee.
Results
Even if the initial sample size was not reached because of low recruitment, 188 subjects were randomised (MEDI3902 500/1500 mg:
n
= 16/87; placebo:
n
= 85) between 13 April 2016 and 17 October 2019. Out of these, 184 were dosed (MEDI3902 500/1500 mg:
n
= 16/85; placebo:
n
= 83), comprising the modified intent-to-treat set. Enrolment in the 500 mg arm was discontinued due to pharmacokinetic data demonstrating low MEDI3902 serum concentrations. Subsequently, enrolled subjects were randomised (1:1) to MEDI3902 1500 mg or placebo. PA pneumonia was confirmed in 22.4% (
n
= 19/85) of MEDI3902 1500 mg recipients and in 18.1% (
n
= 15/83) of placebo recipients (relative risk reduction RRR: − 23.7%; 80% confidence interval CI − 83.8%, 16.8%;
p
= 0.49). At 21 days post-1500 mg dose, the mean (standard deviation) serum MEDI3902 concentration was 9.46 (7.91) μg/mL, with 80.6% (
n
= 58/72) subjects achieving concentrations > 1.7 μg/mL, a level associated with improved outcome in animal models. Treatment-emergent adverse event incidence was similar between groups.
Conclusions
The bivalent, bispecific monoclonal antibody MEDI3902 (gremubamab) did not reduce PA nosocomial pneumonia incidence in PA-colonised mechanically ventilated subjects.
Trial registration
Registered on Clinicaltrials.gov (
NCT02696902
) on 11th February 2016 and on EudraCT (
2015-001706-34
) on 7th March 2016.
PDF
