All the Limbs We Cannot See Bischoff, Moritz S.; Kolossvary, Endre
European journal of vascular and endovascular surgery,
07/2024, Letnik:
68, Številka:
1
Journal Article
Most studies on buoyant microplastics in the marine environment rely on sea surface sampling. Consequently, microplastic amounts can be underestimated, as turbulence leads to vertical mixing. Models ...that correct for vertical mixing are based on limited data. In this study we report measurements of the depth profile of buoyant microplastics in the North Atlantic subtropical gyre, from 0 to 5 m depth. Microplastics were separated into size classes (0.5-1.5 and 1.5-5.0 mm) and types ('fragments' and 'lines'), and associated with a sea state. Microplastic concentrations decreased exponentially with depth, with both sea state and particle properties affecting the steepness of the decrease. Concentrations approached zero within 5 m depth, indicating that most buoyant microplastics are present on or near the surface. Plastic rise velocities were also measured, and were found to differ significantly for different sizes and shapes. Our results suggest that (1) surface samplers such as manta trawls underestimate total buoyant microplastic amounts by a factor of 1.04-30.0 and (2) estimations of depth-integrated buoyant plastic concentrations should be done across different particle sizes and types. Our findings can assist with improving buoyant ocean plastic vertical mixing models, mass balance exercises, impact assessments and mitigation strategies.
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Although bacterial nanocellulose (BNC) has been widely investigated in the last 10years as drug delivery system, up to now no long-term controlled release of drugs could be realized. ...Therefore, the aim of the present work was the development of a BNC-based drug delivery system that provides prolonged retention time for the antiseptic octenidine up to one week with improved mechanical and antimicrobial properties as well as a high biocompatibility. BNC was modified by incorporation of differently concentrated Poloxamers 338 and 407 as micelles and gels that were extensively investigated regarding size, surface charge, and dynamic viscosity. Depending on type and concentration of the Poloxamer, a retarded octenidine release up to one week could be accomplished. Additionally, superior material properties such as high compression stability and water binding could be achieved. The antimicrobial activity of octenidine against Staphylococcus aureus and Pseudomonas aeruginosa was not changed by the use of Poloxamers. Excellent biocompatibility of the Poloxamer loaded BNC could be demonstrated after local administration in a shell-less hen’s egg model. In conclusion, a long-term delivery system consisting of BNC and Poloxamer could be developed for octenidine as a ready-to-use system e.g. for long-term dermal wound treatment.
ABSTRACT
Dark matter (DM) self-interactions have been proposed to solve problems on small length scales within the standard cold DM cosmology. Here, we investigate the effects of DM self-interactions ...in merging systems of galaxies and galaxy clusters with equal and unequal mass ratios. We perform N-body DM-only simulations of idealized setups to study the effects of DM self-interactions that are elastic and velocity-independent. We go beyond the commonly adopted assumption of large-angle (rare) DM scatterings, paying attention to the impact of small-angle (frequent) scatterings on astrophysical observables and related quantities. Specifically, we focus on DM-galaxy offsets, galaxy–galaxy distances, halo shapes, morphology, and the phase–space distribution. Moreover, we compare two methods to identify peaks: one based on the gravitational potential and one based on isodensity contours. We find that the results are sensitive to the peak finding method, which poses a challenge for the analysis of merging systems in simulations and observations, especially for minor mergers. Large DM-galaxy offsets can occur in minor mergers, especially with frequent self-interactions. The subhalo tends to dissolve quickly for these cases. While clusters in late merger phases lead to potentially large differences between rare and frequent scatterings, we believe that these differences are non-trivial to extract from observations. We therefore study the galaxy/star populations which remain distinct even after the DM haloes have coalesced. We find that these collisionless tracers behave differently for rare and frequent scatterings, potentially giving a handle to learn about the micro-physics of DM.
It is well known that web-based interventions can be effective treatments for depression. However, dropout rates in web-based interventions are typically high, especially in self-guided web-based ...interventions. Rigorous empirical evidence regarding factors influencing dropout in self-guided web-based interventions is lacking due to small study sample sizes. In this paper we examined predictors of dropout in an individual patient data meta-analysis to gain a better understanding of who may benefit from these interventions.
A comprehensive literature search for all randomized controlled trials (RCTs) of psychotherapy for adults with depression from 2006 to January 2013 was conducted. Next, we approached authors to collect the primary data of the selected studies. Predictors of dropout, such as socio-demographic, clinical, and intervention characteristics were examined.
Data from 2705 participants across ten RCTs of self-guided web-based interventions for depression were analysed. The multivariate analysis indicated that male gender relative risk (RR) 1.08, lower educational level (primary education, RR 1.26) and co-morbid anxiety symptoms (RR 1.18) significantly increased the risk of dropping out, while for every additional 4 years of age, the risk of dropping out significantly decreased (RR 0.94).
Dropout can be predicted by several variables and is not randomly distributed. This knowledge may inform tailoring of online self-help interventions to prevent dropout in identified groups at risk.
ABSTRACT
Dark matter (DM) with self-interactions is a promising solution for the small-scale problems of the standard cosmological model. Here we perform the first cosmological simulation of frequent ...DM self-interactions, corresponding to small-angle DM scatterings. The focus of our analysis lies in finding and understanding differences to the traditionally assumed rare DM (large-angle) self-scatterings. For this purpose, we compute the distribution of DM densities, the matter power spectrum, the two-point correlation function, and the halo and subhalo mass functions. Furthermore, we investigate the density profiles of the DM haloes and their shapes. We find that overall large-angle and small-angle scatterings behave fairly similarly with a few exceptions. In particular, the number of satellites is considerably suppressed for frequent compared to rare self-interactions with the same cross-section. Overall, we observe that while differences between the two cases may be difficult to establish using a single measure, the degeneracy may be broken through a combination of multiple ones. For instance, the combination of satellite counts with halo density or shape profiles could allow discriminating between rare and frequent self-interactions. As a by-product of our analysis, we provide – for the first time – upper limits on the cross-section for frequent self-interactions.
Abstract Objective The aim of this study was to analyze the outcome of thoracic endovascular aortic repair (TEVAR) and medical therapy in patients with aortic intramural hematoma type B (IMHB). ...Methods Between January 2004 and January 2014, 41 IMHB patients were treated; 28 underwent TEVAR (16 male; median age, 69 years; group I) plus best medical therapy (BMT), whereas 13 had BMT alone (6 male; median age, 69 years; group II). Study end points were assessment of indications for TEVAR and BMT, clinical outcome, and evaluation of aortic morphology over time. Median follow-up was 32 months for group I and 40 months for group II. Results In group I, TEVAR was immediately performed in 7 of 28 cases because of pain and imaging results (penetrating aortic ulcers, n = 4; intramural blood pools, n = 3). In 21 of 28 cases, TEVAR was undertaken because of clinical or radiologic signs of progression at a median of 10 days (range, 2-223 days). The median number of stent grafts implanted was two (range, 1-3). The median length of covered aorta was 15 cm (range, 9.5-33.4 cm). Technical success was achieved in 25 of 28. In-hospital mortality was 1 of 28 in group I and 0 of 13 in group II. Survival in group I was 81.5%, 77.8%, and 67% at 1, 2, and 4 years. There was no death in group II during follow-up. Aortic reinterventions were performed in 6 of 28 group I cases, including 2 open conversions for retrograde type A dissection. Aortic diameter decreased during follow-up in 10% in group I (vs 3% in group II; P = .039). In group I, complete remodeling was seen in 7 of 27, regression in the remaining 20. In group II, complete remodeling was seen in 3 of 12; regression was seen in 9 of 12. No patient in group II required invasive treatment. Conclusions BMT is justified in uncomplicated IMHB. However, IMHB becomes complicated in the majority of patients within 20 days. TEVAR in complicated IMHB is feasible but associated with a substantial aortic reintervention rate, reflecting technical challenges and fragile aortic wall conditions.
In contrast to enamel, dentin surfaces have been rarely used as substrates for studies evaluating the effects of experimental rinsing solutions on oral biofilm formation. The aim of the present in ...situ study was to investigate the effects of tannic acid and chitosan on 48-h biofilm formation on dentin surfaces. Biofilm was formed intraorally on dentin specimens, while six subjects rinsed with experimental solutions containing tannic acid, chitosan and water as negative or chlorhexidine as positive control. After 48 h of biofilm formation, specimens were evaluated for biofilm coverage and for viability of bacteria by fluorescence and scanning electron microscopy. In addition, saliva samples were collected after rinsing and analyzed by fluorescence (five subjects) and transmission electron microscopy (two subjects) in order to investigate the antibacterial effect on bacteria in a planktonic state and to visualize effects of the rinsing agents on salivary proteins. After rinsing with water, dentin specimens were covered by a multiple-layered biofilm with predominantly vital bacteria. In contrast, chlorhexidine led to dentin surfaces covered only by few and avital bacteria. By rinsing with tannic acid both strong anti-adherent and antibacterial effects were observed, but the effects declined in a time-dependent manner. Transmission electron micrographs of salivary samples indicated that aggregation of proteins and bacteria might explain the antiadhesion effects of tannic acid. Chitosan showed antibacterial effects on bacteria in saliva, while biofilm viability was only slightly reduced and no effects on bacterial adherence on dentin were observed, despite proteins being aggregated in saliva after rinsing with chitosan. Tannic acid is a promising anti-biofilm agent even on dentin surfaces, while rinsing with chitosan could not sufficiently prevent biofilm formation on dentin.
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