Fabrication of multifunctional titanium surfaces by producing hierarchical surface patterns using laser based ablation methods

Textured implant surfaces with micrometer and sub-micrometer features can improve contact properties like cell adhesion and bacteria repellency. A critical point of these surfaces is their mechanical stability during implantation. Therefore, strategies capable to provide both biocompatibility for an improved implant healing and resistance to wear for protecting the functional surface are required. In this work, laser-based fabrication methods have been used to produce hierarchical patterns on titanium surfaces. Using Direct Laser Writing with a nanosecond pulsed laser, crater-like structures with a separation distance of 50 µm are produced on unpolished titanium surfaces. Directly on this texture, a hole-like pattern with 5 µm spatial period is generated using Direct Laser Interference Patterning with picosecond pulses. While the smaller features should reduce the bacterial adhesion, the larger geometry was designed to protect the smaller features from wear. On the multifunctional surface, the adherence of E. Coli bacteria is reduced by 30% compared to the untreated reference. In addition, wear test performed on the multiple-scale patterns demonstrated the possibility to protect the smaller features by the larger craters. Also, the influence of the laser treatment on the growth of a titanium oxide layer was evaluated using Energy Dispersive X-Ray Spectroscopy analysis. © 2019, The Author(s)

In Situ Experiments To Reveal the Role of Surface Feature Sidewalls in the Cassie–Wenzel Transition

Waterproof and self-cleaning surfaces continue to attract much attention as they can be instrumental in various different technologies. Such surfaces are typically rough, allowing liquids to contact only the outermost tops of their asperities, with air being entrapped underneath. The formed solid–liquid–air interface is metastable and, hence, can be forced into a completely wetted solid surface. A detailed understanding of the wetting barrier and the dynamics of this transition is critically important for the practical use of the related surfaces. Toward this aim, wetting transitions were studied in situ at a set of patterned perfluoropolyether dimethacrylate (PFPEdma) polymer surfaces exhibiting surface features with different types of sidewall profiles. PFPEdma is intrinsically hydrophobic and exhibits a refractive index very similar to water. Upon immersion of the patterned surfaces into water, incident light was differently scattered at the solid–liquid–air and solid–liquid interface, which allows for distinguishing between both wetting states by dark-field microscopy. The wetting transition observed with this methodology was found to be determined by the sidewall profiles of the patterned structures. Partial recovery of the wetting was demonstrated to be induced by abrupt and continuous pressure reductions. A theoretical model based on Laplace’s law was developed and applied, allowing for the analytical calculation of the transition barrier and the potential to revert the wetting upon pressure reduction

The development of the würde + infinitive construction in Early Modern German (1650–1800)

This paper presents a corpus-based analysis of the evolution of the würde + infinitive construction in German during the Early Modern period (1650– 1800), using newly available data from the GerManC-corpus. We demonstrate how this construction occupies a unique position orthogonal to both the tense and mood systems of German through an analysis of the syntax and semantics of würde + infinitive clauses, beginning with Modern Standard German and then subsequently with a historical focus on the late seventeenth and eighteenth centuries. Through both quantitative and qualitative analyses, we examine the contexts in which the construction occurs and see how, as it came to be used more frequently over the period in question, it encroached more and more into contexts which had been the preserve of the synthetic preterite subjunctive, even being used in some where the latter is still the norm in modern German. Thus, by the end of the eighteenth century it had become difficult to identify a clear difference in meaning and use between these forms, and the reasons why the würde + in- finitive construction may be preferred over the synthetic preterite subjunctive are by no means clear. We conclude our discussion with an overview of how the würde + infinitive construction was received in the prescriptive tradition during this key period in the standardization of German, seeing its stigmatization in some contexts in part as an attempt by prescriptive grammarians to establish an explicit and clearly justified role for it in the language

Smart Skin Patterns Protect Springtails

Springtails, arthropods who live in soil, in decaying material, and on plants, have adapted to demanding conditions by evolving extremely effective and robust anti-adhesive skin patterns. However, details of these unique properties and their structural basis are still unknown. Here we demonstrate that collembolan skin can resist wetting by many organic liquids and at elevated pressures. We show that the combination of bristles and a comb-like hexagonal or rhombic mesh of interconnected nanoscopic granules distinguish the skin of springtails from anti-adhesive plant surfaces. Furthermore, the negative overhang in the profile of the ridges and granules were revealed to be a highly effective, but as yet neglected, design principle of collembolan skin. We suggest an explanation for the non-wetting characteristics of surfaces consisting of such profiles irrespective of the chemical composition. Many valuable opportunities arise from the translation of the described comb-like patterns and overhanging profiles of collembolan skin into man-made surfaces that combine stability against wear and friction with superior non-wetting and anti-adhesive characteristics

Structural characteristics and contractual terms of specialist palliative homecare in Germany

Background Multi-professional specialist palliative homecare (SPHC) teams care for palliative patients with complex symptoms. In Germany, the SPHC directive regulates care provision, but model contracts for each federal state are heterogeneous regarding staff requirements, cooperation with other healthcare providers, and financial reimbursement. The structural characteristics of SPHC teams also vary. Aim We provide a structured overview of the existing model contracts, as well as a nationwide assessment of SPHC teams and their structural characteristics. Furthermore, we explore whether these characteristics serve to find specifc patterns of SPHC team models, based on empirical data. Methods This study is part of the multi-methods research project “SAVOIR”, funded by the German Innovations Fund. Most model contracts are publicly available. Structural characteristics (e.g. number, professions, and affiliations of team members, and external cooperation) were assessed via an online database (“Wegweiser Hospiz- und Palliativversorgung”) based on voluntary information obtained from SPHC teams. All the data were updated by phone during the assessment process. Data were descriptively analysed regarding staff, cooperation requirements, and reimbursement schemes, while latent class analysis (LCA) was used to identify structural team models. Results Model contracts have heterogeneous contract partners and terms related to staff requirements (number and qualifications) and cooperation with other services. Fourteen reimbursement schemes were available, all combining different payment models. Of the 283 SPHC teams, 196 provided structural characteristics. Teams reported between one and 298 members (mean: 30.3, median: 18), mainly nurses and physicians, while 37.8% had a psychosocial professional as a team member. Most teams were composed of nurses and physicians employed in different settings; for example, staff was employed by the team, in private practices/nursing services, or in hospitals. Latent class analysis identified four structural team models, based on the team size, team members’ affiliation, and care organisation. Conclusion Both the contractual terms and teams’ structural characteristics vary substantially, and this must be considered when analysing patient data from SPHC. The identified patterns of team models can form a starting point from which to analyse different forms of care provision and their impact on care quality

Loss-of-function mutations in UDP-Glucose 6-Dehydrogenase cause recessive developmental epileptic encephalopathy

AbstractDevelopmental epileptic encephalopathies are devastating disorders characterized by intractable epileptic seizures and developmental delay. Here, we report an allelic series of germline recessive mutations in UGDH in 36 cases from 25 families presenting with epileptic encephalopathy with developmental delay and hypotonia. UGDH encodes an oxidoreductase that converts UDP-glucose to UDP-glucuronic acid, a key component of specific proteoglycans and glycolipids. Consistent with being loss-of-function alleles, we show using patients’ primary fibroblasts and biochemical assays, that these mutations either impair UGDH stability, oligomerization, or enzymatic activity. In vitro, patient-derived cerebral organoids are smaller with a reduced number of proliferating neuronal progenitors while mutant ugdh zebrafish do not phenocopy the human disease. Our study defines UGDH as a key player for the production of extracellular matrix components that are essential for human brain development. Based on the incidence of variants observed, UGDH mutations are likely to be a frequent cause of recessive epileptic encephalopathy.</jats:p

Loss-of-function mutations in UDP-Glucose 6-Dehydrogenase cause recessive developmental epileptic encephalopathy

Developmental epileptic encephalopathies are devastating disorders characterized by intractable epileptic seizures and developmental delay. Here, we report an allelic series of germline recessive mutations in UGDH in 36 cases from 25 families presenting with epileptic encephalopathy with developmental delay and hypotonia. UGDH encodes an oxidoreductase that converts UDP-glucose to UDP-glucuronic acid, a key component of specific proteoglycans and glycolipids. Consistent with being loss-of-function alleles, we show using patients’ primary fibroblasts and biochemical assays, that these mutations either impair UGDH stability, oligomerization, or enzymatic activity. In vitro, patient-derived cerebral organoids are smaller with a reduced number of proliferating neuronal progenitors while mutant ugdh zebrafish do not phenocopy the human disease. Our study defines UGDH as a key player for the production of extracellular matrix components that are essential for human brain development. Based on the incidence of variants observed, UGDH mutations are likely to be a frequent cause of recessive epileptic encephalopathy